---
OA_place: publisher
_id: '1124'
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Maurizio
full_name: Morri, Maurizio
id: 4863116E-F248-11E8-B48F-1D18A9856A87
last_name: Morri
citation:
ama: Morri M. Optical functionalization of human class A orphan G-protein coupled
receptors. 2016.
apa: Morri, M. (2016). Optical functionalization of human class A orphan G-protein
coupled receptors. Institute of Science and Technology Austria.
chicago: Morri, Maurizio. “Optical Functionalization of Human Class A Orphan G-Protein
Coupled Receptors.” Institute of Science and Technology Austria, 2016.
ieee: M. Morri, “Optical functionalization of human class A orphan G-protein coupled
receptors,” Institute of Science and Technology Austria, 2016.
ista: Morri M. 2016. Optical functionalization of human class A orphan G-protein
coupled receptors. Institute of Science and Technology Austria.
mla: Morri, Maurizio. Optical Functionalization of Human Class A Orphan G-Protein
Coupled Receptors. Institute of Science and Technology Austria, 2016.
short: M. Morri, Optical Functionalization of Human Class A Orphan G-Protein Coupled
Receptors, Institute of Science and Technology Austria, 2016.
corr_author: '1'
date_created: 2018-12-11T11:50:17Z
date_published: 2016-03-01T00:00:00Z
date_updated: 2026-04-08T14:26:54Z
day: '01'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: HaJa
file:
- access_level: closed
checksum: b439803ac0827cdddd56562a54e3b53b
content_type: application/pdf
creator: dernst
date_created: 2019-08-13T10:50:00Z
date_updated: 2019-08-13T10:50:00Z
file_id: '6812'
file_name: MORRI_PhD_thesis_FINALPLUSSIGNATURES (2).pdf
file_size: 4785167
relation: main_file
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checksum: dd4136247fe472e7d47880ec68ac8de0
content_type: application/pdf
creator: dernst
date_created: 2021-02-22T11:42:06Z
date_updated: 2021-02-22T11:42:06Z
file_id: '9180'
file_name: 2016_MORRI_Thesis.pdf
file_size: 4495669
relation: main_file
success: 1
file_date_updated: 2021-02-22T11:42:06Z
has_accepted_license: '1'
language:
- iso: eng
month: '03'
oa: 1
oa_version: Published Version
page: '129'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '6236'
status: public
supervisor:
- first_name: Harald L
full_name: Janovjak, Harald L
id: 33BA6C30-F248-11E8-B48F-1D18A9856A87
last_name: Janovjak
orcid: 0000-0002-8023-9315
title: Optical functionalization of human class A orphan G-protein coupled receptors
type: dissertation
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
year: '2016'
...
---
OA_place: publisher
_id: '1129'
abstract:
- lang: eng
text: "Directed cell migration is a hallmark feature, present in almost all multi-cellular\r\norganisms.
Despite its importance, basic questions regarding force transduction\r\nor directional
sensing are still heavily investigated. Directed migration of cells\r\nguided
by immobilized guidance cues - haptotaxis - occurs in key-processes,\r\nsuch as
embryonic development and immunity (Middleton et al., 1997; Nguyen\r\net al.,
2000; Thiery, 1984; Weber et al., 2013). Immobilized guidance cues\r\ncomprise
adhesive ligands, such as collagen and fibronectin (Barczyk et al.,\r\n2009),
or chemokines - the main guidance cues for migratory leukocytes\r\n(Middleton
et al., 1997; Weber et al., 2013). While adhesive ligands serve as\r\nattachment
sites guiding cell migration (Carter, 1965), chemokines instruct\r\nhaptotactic
migration by inducing adhesion to adhesive ligands and directional\r\nguidance
(Rot and Andrian, 2004; Schumann et al., 2010). Quantitative analysis\r\nof the
cellular response to immobilized guidance cues requires in vitro assays\r\nthat
foster cell migration, offer accurate control of the immobilized cues on a\r\nsubcellular
scale and in the ideal case closely reproduce in vivo conditions. The\r\nexploration
of haptotactic cell migration through design and employment of such\r\nassays
represents the main focus of this work.\r\nDendritic cells (DCs) are leukocytes,
which after encountering danger\r\nsignals such as pathogens in peripheral organs
instruct naïve T-cells and\r\nconsequently the adaptive immune response in the
lymph node (Mellman and\r\nSteinman, 2001). To reach the lymph node from the periphery,
DCs follow\r\nhaptotactic gradients of the chemokine CCL21 towards lymphatic vessels\r\n(Weber
et al., 2013). Questions about how DCs interpret haptotactic CCL21\r\ngradients
have not yet been addressed. The main reason for this is the lack of\r\nan assay
that offers diverse haptotactic environments, hence allowing the study\r\nof DC
migration as a response to different signals of immobilized guidance cue.\r\nIn
this work, we developed an in vitro assay that enables us to\r\nquantitatively
assess DC haptotaxis, by combining precisely controllable\r\nchemokine photo-patterning
with physically confining migration conditions. With this tool at hand, we studied
the influence of CCL21 gradient properties and\r\nconcentration on DC haptotaxis.
We found that haptotactic gradient sensing\r\ndepends on the absolute CCL21 concentration
in combination with the local\r\nsteepness of the gradient. Our analysis suggests
that the directionality of\r\nmigrating DCs is governed by the signal-to-noise
ratio of CCL21 binding to its\r\nreceptor CCR7. Moreover, the haptotactic CCL21
gradient formed in vivo\r\nprovides an optimal shape for DCs to recognize haptotactic
guidance cue.\r\nBy reconstitution of the CCL21 gradient in vitro we were also
able to\r\nstudy the influence of CCR7 signal termination on DC haptotaxis. To
this end,\r\nwe used DCs lacking the G-protein coupled receptor kinase GRK6, which
is\r\nresponsible for CCL21 induced CCR7 receptor phosphorylation and\r\ndesensitization
(Zidar et al., 2009). We found that CCR7 desensitization by\r\nGRK6 is crucial
for maintenance of haptotactic CCL21 gradient sensing in vitro\r\nand confirm
those observations in vivo.\r\nIn the context of the organism, immobilized haptotactic
guidance cues\r\noften coincide and compete with soluble chemotactic guidance
cues. During\r\nwound healing, fibroblasts are exposed and influenced by adhesive
cues and\r\nsoluble factors at the same time (Wu et al., 2012; Wynn, 2008). Similarly,\r\nmigrating
DCs are exposed to both, soluble chemokines (CCL19 and truncated\r\nCCL21) inducing
chemotactic behavior as well as the immobilized CCL21. To\r\nquantitatively assess
these complex coinciding immobilized and soluble\r\nguidance cues, we implemented
our chemokine photo-patterning technique in a\r\nmicrofluidic system allowing
for chemotactic gradient generation. To validate\r\nthe assay, we observed DC
migration in competing CCL19/CCL21\r\nenvironments.\r\nAdhesiveness guided haptotaxis
has been studied intensively over the\r\nlast century. However, quantitative studies
leading to conceptual models are\r\nlargely missing, again due to the lack of
a precisely controllable in vitro assay. A\r\nrequirement for such an in vitro
assay is that it must prevent any uncontrolled\r\ncell adhesion. This can be accomplished
by stable passivation of the surface. In\r\naddition, controlled adhesion must
be sustainable, quantifiable and dose\r\ndependent in order to create homogenous
gradients. Therefore, we developed a novel covalent photo-patterning technique
satisfying all these needs. In\r\ncombination with a sustainable poly-vinyl alcohol
(PVA) surface coating we\r\nwere able to generate gradients of adhesive cue to
direct cell migration. This\r\napproach allowed us to characterize the haptotactic
migratory behavior of\r\nzebrafish keratocytes in vitro. Furthermore, defined
patterns of adhesive cue\r\nallowed us to control for cell shape and growth on
a subcellular scale."
acknowledged_ssus:
- _id: Bio
- _id: PreCl
- _id: LifeSc
acknowledgement: "First, I would like to thank Michael Sixt for being a great supervisor,
mentor and\r\nscientist. I highly appreciate his guidance and continued support.
Furthermore, I\r\nam very grateful that he gave me the exceptional opportunity to
pursue many\r\nideas of which some managed to be included in this thesis.\r\nI owe
sincere thanks to the members of my PhD thesis committee, Daria\r\nSiekhaus, Daniel
Legler and Harald Janovjak. Especially I would like to thank\r\nDaria for her advice
and encouragement during our regular progress meetings.\r\nI also want to thank
the team and fellows of the Boehringer Ingelheim Fond\r\n(BIF) PhD Fellowship for
amazing and inspiring meetings and the BIF for\r\nfinancial support.\r\nImportant
factors for the success of this thesis were the warm, creative\r\nand helpful atmosphere
as well as the team spirit of the whole Sixt Lab.\r\nTherefore I would like to thank
my current and former colleagues Frank Assen,\r\nMarkus Brown, Ingrid de Vries,
Michelle Duggan, Alexander Eichner, Miroslav\r\nHons, Eva Kiermaier, Aglaja Kopf,
Alexander Leithner, Christine Moussion, Jan\r\nMüller, Maria Nemethova, Jörg Renkawitz,
Anne Reversat, Kari Vaahtomeri,\r\nMichele Weber and Stefan Wieser. We had an amazing
time with many\r\nlegendary evenings and events. Along these lines I want to thank
the in vitro\r\ncrew of the lab, Jörg, Anne and Alex, for lots of ideas and productive\r\ndiscussions.
I am sure, some day we will reveal the secret of the ‘splodge’.\r\nI want to thank
the members of the Heisenberg Lab for a great time and\r\nthrilling kicker matches.
In this regard I especially want to thank Maurizio\r\n‘Gnocci’ Monti, Gabriel Krens,
Alex Eichner, Martin Behrndt, Vanessa Barone,Philipp Schmalhorst, Michael Smutny,
Daniel Capek, Anne Reversat, Eva\r\nKiermaier, Frank Assen and Jan Müller for wonderful
after-lunch matches.\r\nI would not have been able to analyze the thousands of cell
trajectories\r\nand probably hundreds of thousands of mouse clicks without the productive\r\ncollaboration
with Veronika Bierbaum and Tobias Bollenbach. Thanks Vroni for\r\ncountless meetings,
discussions and graphs and of course for proofreading and\r\nadvice for this thesis.
For proofreading I also want to thank Evi, Jörg, Jack and\r\nAnne.\r\nI would like
to acknowledge Matthias Mehling for a very productive\r\ncollaboration and for introducing
me into the wild world of microfluidics. Jack\r\nMerrin, for countless wafers, PDMS
coated coverslips and help with anything\r\nmicro-fabrication related. And Maria
Nemethova for establishing the ‘click’\r\npatterning approach with me. Without her
it still would be just one of the ideas…\r\nMany thanks to Ekaterina Papusheva,
Robert Hauschild, Doreen Milius\r\nand Nasser Darwish from the Bioimaging Facility
as well as the Preclinical and\r\nthe Life Science facilities of IST Austria for
excellent technical support. At this\r\npoint I especially want to thank Robert
for countless image analyses and\r\ntechnical ideas. Always interested and creative
he played an essential role in all\r\nof my projects.\r\nAdditionally I want to
thank Ingrid and Gabby for welcoming me warmly\r\nwhen I first started at IST, for
scientific and especially mental support in all\r\nthose years, countless coffee
sessions and Heurigen evenings. #BioimagingFacility #LifeScienceFacility #PreClinicalFacility"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Jan
full_name: Schwarz, Jan
id: 346C1EC6-F248-11E8-B48F-1D18A9856A87
last_name: Schwarz
citation:
ama: Schwarz J. Quantitative analysis of haptotactic cell migration. 2016.
apa: Schwarz, J. (2016). Quantitative analysis of haptotactic cell migration.
Institute of Science and Technology Austria.
chicago: Schwarz, Jan. “Quantitative Analysis of Haptotactic Cell Migration.” Institute
of Science and Technology Austria, 2016.
ieee: J. Schwarz, “Quantitative analysis of haptotactic cell migration,” Institute
of Science and Technology Austria, 2016.
ista: Schwarz J. 2016. Quantitative analysis of haptotactic cell migration. Institute
of Science and Technology Austria.
mla: Schwarz, Jan. Quantitative Analysis of Haptotactic Cell Migration. Institute
of Science and Technology Austria, 2016.
short: J. Schwarz, Quantitative Analysis of Haptotactic Cell Migration, Institute
of Science and Technology Austria, 2016.
corr_author: '1'
date_created: 2018-12-11T11:50:18Z
date_published: 2016-07-01T00:00:00Z
date_updated: 2026-04-08T14:28:53Z
day: '01'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: MiSi
file:
- access_level: closed
checksum: e3cd6b28f9c5cccb8891855565a2dade
content_type: application/pdf
creator: dernst
date_created: 2019-08-13T10:55:35Z
date_updated: 2019-08-13T10:55:35Z
file_id: '6813'
file_name: Thesis_JSchwarz_final.pdf
file_size: 32044069
relation: main_file
- access_level: open_access
checksum: c3dbe219acf87eed2f46d21d5cca00de
content_type: application/pdf
creator: dernst
date_created: 2021-02-22T11:43:14Z
date_updated: 2021-02-22T11:43:14Z
file_id: '9181'
file_name: 2016_Thesis_JSchwarz.pdf
file_size: 8396717
relation: main_file
success: 1
file_date_updated: 2021-02-22T11:43:14Z
has_accepted_license: '1'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
page: '178'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '6231'
status: public
supervisor:
- first_name: Michael K
full_name: Sixt, Michael K
id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
last_name: Sixt
orcid: 0000-0002-6620-9179
title: Quantitative analysis of haptotactic cell migration
type: dissertation
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
year: '2016'
...
---
_id: '11519'
abstract:
- lang: eng
text: 'Faint Lyα emitters become increasingly rarer toward the reionization epoch
(z ∼ 6–7). However, observations from a very large (∼5 deg2) Lyα narrow-band survey
at z = 6.6 show that this is not the case for the most luminous emitters, capable
of ionizing their own local bubbles. Here we present follow-up observations of
the two most luminous Lyα candidates in the COSMOS field: “MASOSA” and “CR7.”
We used X-SHOOTER, SINFONI, and FORS2 on the Very Large Telescope, and DEIMOS
on Keck, to confirm both candidates beyond any doubt. We find redshifts of z =
6.541 and z = 6.604 for “MASOSA” and “CR7,” respectively. MASOSA has a strong
detection in Lyα with a line width of 386 ± 30 km s−1 (FWHM) and with very high
EW0 (>200 Å), but undetected in the continuum, implying very low stellar mass
and a likely young, metal-poor stellar population. “CR7,” with an observed Lyα
luminosity of 1043.92±0.05 erg s−1 is the most luminous Lyα emitter ever found
at z > 6 and is spatially extended (∼16 kpc). “CR7” reveals a narrow Lyα line
with 266 ± 15 km s−1 FWHM, being detected in the near-infrared (NIR) (rest-frame
UV; β = −2.3 ± 0.1) and in IRAC/Spitzer. We detect a narrow He II 1640 Å emission
line (6σ, FWHM = 130 ± 30 km s−1 ) in CR7 which can explain the clear excess seen
in the J-band photometry (EW0 ∼ 80 Å). We find no other emission lines from the
UV to the NIR in our X-SHOOTER spectra (He II/O III] 1663 Å > 3 and He II/C III]
1908 Å > 2.5). We conclude that CR7 is best explained by a combination of a PopIII-like
population, which dominates the rest-frame UV and the nebular emission, and a
more normal stellar population, which presumably dominates the mass. Hubble Space
Telescope/WFC3 observations show that the light is indeed spatially separated
between a very blue component, coincident with Lyα and He II emission, and two
red components (∼5 kpc away), which dominate the mass. Our findings are consistent
with theoretical predictions of a PopIII wave, with PopIII star formation migrating
away from the original sites of star formation.'
acknowledgement: We thank the anonymous reviewer for useful and constructive comments
and suggestions which greatly improved the quality and clarity of our work. D.S.
acknowledges financial support from the Netherlands Organisation for Scientific
research (NWO) through a Veni fellowship, from FCT through a FCT Investigator Starting
Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010), from FCT grant UID/FIS/04434/2013,
and from LSF and LKBF. J.M. acknowledges the award of a Huygens PhD fellowship.
H.R. acknowledges support from the ERC Advanced Investigator program NewClusters
321271. The authors thank Mark Dijkstra, Bhaskar Agarwal, Jarrett Johnson, Andrea
Ferrara, Jarle Brinchmann, Rebecca Bowler, George Becker, Emma Curtis-Lake, Milos
Milosavljevic, Raffaella Schneider, Paul Shapiro, and Erik Zackrisson for interesting,
stimulating and helpful discussions. The authors are extremely grateful to ESO for
the award of ESO DDT time (294.A-5018 and 294.A-5039) which allowed the spectroscopic
confirmation of both sources and the detailed investigation of their nature. Observations
are also based on data from W.M. Keck Observatory. The W.M. Keck Observatory is
operated as a scientific partnership of Caltech, the University of California and
the National Aeronautics and Space Administration. Based on observations obtained
with MegaPrime/Megacam, a joint project of CFHT and CEA/IRFU, at the Canada–France–Hawaii
Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada,
the Institut National des Science de lUnivers of the Centre National de la Recherche
Scientifique (CNRS) of France, and the University of Hawaii. This work is based
in part on data products produced at Terapix available at the Canadian Astronomy
Data Centre as part of the Canada–France–Hawaii Telescope Legacy Survey, a collaborative
project of NRC and CNRS. Based on data products from observations made with ESO
Telescopes at the La Silla Paranal Observatory under ESO programme IDs 294.A-5018,
294.A-5039, and 179.A-2005, and on data products produced by TERAPIX and the Cambridge
Astronomy Survey Unit on behalf of the UltraVISTA consortium. The authors acknowledge
the award of service time (SW2014b20) on the William Herschel Telescope (WHT). WHT
and its service programme are operated on the island of La Palma by the Isaac Newton
Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de
Astrofisica de Canarias.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: David
full_name: Sobral, David
last_name: Sobral
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Behnam
full_name: Darvish, Behnam
last_name: Darvish
- first_name: Daniel
full_name: Schaerer, Daniel
last_name: Schaerer
- first_name: Bahram
full_name: Mobasher, Bahram
last_name: Mobasher
- first_name: Huub
full_name: Röttgering, Huub
last_name: Röttgering
- first_name: Sérgio
full_name: Santos, Sérgio
last_name: Santos
- first_name: Shoubaneh
full_name: Hemmati, Shoubaneh
last_name: Hemmati
citation:
ama: 'Sobral D, Matthee JJ, Darvish B, et al. Evidence for PopIII-like stellar populations
in the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic
confirmation. The Astrophysical Journal. 2015;808(2):139. doi:10.1088/0004-637X/808/2/139'
apa: 'Sobral, D., Matthee, J. J., Darvish, B., Schaerer, D., Mobasher, B., Röttgering,
H., … Hemmati, S. (2015). Evidence for PopIII-like stellar populations in the
most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation.
The Astrophysical Journal. IOP Publishing. https://doi.org/10.1088/0004-637X/808/2/139'
chicago: 'Sobral, David, Jorryt J Matthee, Behnam Darvish, Daniel Schaerer, Bahram
Mobasher, Huub Röttgering, Sérgio Santos, and Shoubaneh Hemmati. “Evidence for
PopIII-like Stellar Populations in the Most Luminous Lyα Emitters at the Epoch
of Reionisation: Spectroscopic Confirmation.” The Astrophysical Journal.
IOP Publishing, 2015. https://doi.org/10.1088/0004-637X/808/2/139.'
ieee: 'D. Sobral et al., “Evidence for PopIII-like stellar populations in
the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation,”
The Astrophysical Journal, vol. 808, no. 2. IOP Publishing, p. 139, 2015.'
ista: 'Sobral D, Matthee JJ, Darvish B, Schaerer D, Mobasher B, Röttgering H, Santos
S, Hemmati S. 2015. Evidence for PopIII-like stellar populations in the most luminous
Lyα emitters at the epoch of reionisation: Spectroscopic confirmation. The Astrophysical
Journal. 808(2), 139.'
mla: 'Sobral, David, et al. “Evidence for PopIII-like Stellar Populations in the
Most Luminous Lyα Emitters at the Epoch of Reionisation: Spectroscopic Confirmation.”
The Astrophysical Journal, vol. 808, no. 2, IOP Publishing, 2015, p. 139,
doi:10.1088/0004-637X/808/2/139.'
short: D. Sobral, J.J. Matthee, B. Darvish, D. Schaerer, B. Mobasher, H. Röttgering,
S. Santos, S. Hemmati, The Astrophysical Journal 808 (2015) 139.
date_created: 2022-07-07T09:00:58Z
date_published: 2015-07-28T00:00:00Z
date_updated: 2022-08-18T10:30:13Z
day: '28'
doi: 10.1088/0004-637X/808/2/139
extern: '1'
external_id:
arxiv:
- '1504.01734'
intvolume: ' 808'
issue: '2'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- dark ages
- reionization
- 'first stars – early universe – galaxies: evolution'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1504.01734
month: '07'
oa: 1
oa_version: Preprint
page: '139'
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Evidence for PopIII-like stellar populations in the most luminous Lyα emitters
at the epoch of reionisation: Spectroscopic confirmation'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 808
year: '2015'
...
---
_id: '11579'
abstract:
- lang: eng
text: CR7 is the brightest z = 6.6 Ly α emitter (LAE) known to date, and spectroscopic
follow-up by Sobral et al. suggests that CR7 might host Population (Pop) III stars.
We examine this interpretation using cosmological hydrodynamical simulations.
Several simulated galaxies show the same ‘Pop III wave’ pattern observed in CR7.
However, to reproduce the extreme CR7 Ly α/He II1640 line luminosities (Lα/HeII)
a top-heavy initial mass function and a massive ( ≳ 107 M⊙) Pop III burst with
age ≲ 2 Myr are required. Assuming that the observed properties of Ly α and He II
emission are typical for Pop III, we predict that in the COSMOS/UDS/SA22 fields,
14 out of the 30 LAEs at z = 6.6 with Lα > 1043.3 erg s−1 should also host Pop
III stars producing an observable LHeII≳1042.7ergs−1. As an alternate explanation,
we explore the possibility that CR7 is instead powered by accretion on to a direct
collapse black hole. Our model predicts Lα, LHeII, and X-ray luminosities that
are in agreement with the observations. In any case, the observed properties of
CR7 indicate that this galaxy is most likely powered by sources formed from pristine
gas. We propose that further X-ray observations can distinguish between the two
above scenarios.
acknowledgement: SS acknowledges support from the Netherlands Organization for Scientific
research (NWO), VENI grant 639.041.233. RS acknowledges support from the European
Research Council under the European Union (FP/2007-2013)/ERC grant agreement no.
306476. DS acknowledges (i) financial support from the NWO through a Veni fellowship
and (ii) funding from FCT through a FCT Investigator Starting Grant and Start-up
Grant (IF/01154/2012/CP0189/CT0010) and from FCT grant PEstOE/FIS/UI2751/2014.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: A.
full_name: Pallottini, A.
last_name: Pallottini
- first_name: A.
full_name: Ferrara, A.
last_name: Ferrara
- first_name: F.
full_name: Pacucci, F.
last_name: Pacucci
- first_name: S.
full_name: Gallerani, S.
last_name: Gallerani
- first_name: S.
full_name: Salvadori, S.
last_name: Salvadori
- first_name: R.
full_name: Schneider, R.
last_name: Schneider
- first_name: D.
full_name: Schaerer, D.
last_name: Schaerer
- first_name: D.
full_name: Sobral, D.
last_name: Sobral
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
citation:
ama: 'Pallottini A, Ferrara A, Pacucci F, et al. The brightest Lyα emitter: Pop
III or black hole? Monthly Notices of the Royal Astronomical Society. 2015;453(3):2465-2470.
doi:10.1093/mnras/stv1795'
apa: 'Pallottini, A., Ferrara, A., Pacucci, F., Gallerani, S., Salvadori, S., Schneider,
R., … Matthee, J. J. (2015). The brightest Lyα emitter: Pop III or black hole?
Monthly Notices of the Royal Astronomical Society. Oxford University Press.
https://doi.org/10.1093/mnras/stv1795'
chicago: 'Pallottini, A., A. Ferrara, F. Pacucci, S. Gallerani, S. Salvadori, R.
Schneider, D. Schaerer, D. Sobral, and Jorryt J Matthee. “The Brightest Lyα Emitter:
Pop III or Black Hole?” Monthly Notices of the Royal Astronomical Society.
Oxford University Press, 2015. https://doi.org/10.1093/mnras/stv1795.'
ieee: 'A. Pallottini et al., “The brightest Lyα emitter: Pop III or black
hole?,” Monthly Notices of the Royal Astronomical Society, vol. 453, no.
3. Oxford University Press, pp. 2465–2470, 2015.'
ista: 'Pallottini A, Ferrara A, Pacucci F, Gallerani S, Salvadori S, Schneider R,
Schaerer D, Sobral D, Matthee JJ. 2015. The brightest Lyα emitter: Pop III or
black hole? Monthly Notices of the Royal Astronomical Society. 453(3), 2465–2470.'
mla: 'Pallottini, A., et al. “The Brightest Lyα Emitter: Pop III or Black Hole?”
Monthly Notices of the Royal Astronomical Society, vol. 453, no. 3, Oxford
University Press, 2015, pp. 2465–70, doi:10.1093/mnras/stv1795.'
short: A. Pallottini, A. Ferrara, F. Pacucci, S. Gallerani, S. Salvadori, R. Schneider,
D. Schaerer, D. Sobral, J.J. Matthee, Monthly Notices of the Royal Astronomical
Society 453 (2015) 2465–2470.
date_created: 2022-07-14T08:58:36Z
date_published: 2015-11-01T00:00:00Z
date_updated: 2022-08-19T08:19:23Z
day: '01'
doi: 10.1093/mnras/stv1795
extern: '1'
external_id:
arxiv:
- '1506.07173'
intvolume: ' 453'
issue: '3'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- black hole physics
- 'stars: Population III'
- 'galaxies: high-redshift'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1506.07173
month: '11'
oa: 1
oa_version: Preprint
page: 2465-2470
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'The brightest Lyα emitter: Pop III or black hole?'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 453
year: '2015'
...
---
_id: '11580'
abstract:
- lang: eng
text: 'We present results from the largest contiguous narrow-band survey in the
near-infrared. We have used the wide-field infrared camera/Canada–France–Hawaii
Telescope and the lowOH2 filter (1.187 ± 0.005 μm) to survey ≈10 deg2 of contiguous
extragalactic sky in the SA22 field. A total of ∼6000 candidate emission-line
galaxies are found. We use deep ugrizJK data to obtain robust photometric redshifts.
We combine our data with the High-redshift(Z) Emission Line Survey (HiZELS), explore
spectroscopic surveys (VVDS, VIPERS) and obtain our own spectroscopic follow-up
with KMOS, FMOS and MOSFIRE to derive large samples of high-redshift emission-line
selected galaxies: 3471 Hα emitters at z = 0.8, 1343 [O III] + Hβ emitters at
z = 1.4 and 572 [O II] emitters at z = 2.2. We probe comoving volumes of >106
Mpc3 and find significant overdensities, including an 8.5σ (spectroscopically
confirmed) overdensity of Hα emitters at z = 0.81. We derive Hα, [O III] + Hβ
and [O II] luminosity functions at z = 0.8, 1.4, 2.2, respectively, and present
implications for future surveys such as Euclid. Our uniquely large volumes/areas
allow us to subdivide the samples in thousands of randomized combinations of areas
and provide a robust empirical measurement of sample/cosmic variance. We show
that surveys for star-forming/emission-line galaxies at a depth similar to ours
can only overcome cosmic-variance (errors <10 per cent) if they are based on volumes
>5 × 105 Mpc3; errors on L* and ϕ* due to sample (cosmic) variance on surveys
probing ∼104 and ∼105 Mpc3 are typically very high: ∼300 and ∼40–60 per cent,
respectively.'
acknowledgement: The authors wish to thank the anonymous reviewer for many helpful
comments and suggestions which greatly improved the clarity and quality of this
work. DS acknowledges financial support from the Netherlands Organization for Scientific
research (NWO) through a Veni fellowship, from FCT through an FCT Investigator Starting
Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010), from FCT grant PEst-OE/FIS/UI2751/2014,
and from LSF and LKBF. JM acknowledges the award of a Huygens PhD fellowship. PNB
is grateful for support from STFC. IRS acknowledges support from STFC, a Leverhulme
Fellowship, the ERC Advanced Investigator programme DUSTYGAL and a Royal Society/Wolfson
Merit Award. BMJ acknowledges support from the ERC-StG grant EGGS-278202. The Dark
Cosmology Centre is funded by the DNRF. The Dark Cosmology Centre is funded by the
DNRF. JWK acknowledges support from the National Research Foundation of Korea (NRF)
grant, no. 2008-0060544, funded by the Korea government (MSIP). JPS acknowledges
support from STFC (ST/I001573/1). JC acknowledges support from the FCT-IF grant
IF/01154/2012/CP0189/CT0010. The work was only possible due to OPTICON/FP7 and the
invaluable access that it granted to the CFHT telescope. We would also like to acknowledge
the excellent work done by CFHT staff in conducting the observations in service
mode, and on delivering truly excellent data. We are also tremendously thankful
to Kentaro Aoki for the incredible support while observing at Subaru with FMOS,
and also to the Keck staff for the help with the observations with MOSFIRE. This
work is based on observations obtained with WIRCam on the CFHT, OPTICON programme
2011B/029, 2012A019 and 2012B/016. Based on observations made with ESO telescopes
at the La Silla Paranal Observatory under programmes IDs 60.A-9460 (data can be
accessed through the ESO data archive), 087.A 0337 and 089.A-0965. Based on observations
done with FMOS on Subaru under programme S14A-084, and on MOSFIRE/Keck observations
under programme U066M. Part of the data on which this analysis is based are available
from Sobral et al. (2013a). Dedicated to the memory of C. M. Sobral (1953-2014).
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: D.
full_name: Sobral, D.
last_name: Sobral
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: P. N.
full_name: Best, P. N.
last_name: Best
- first_name: I.
full_name: Smail, I.
last_name: Smail
- first_name: A. A.
full_name: Khostovan, A. A.
last_name: Khostovan
- first_name: B.
full_name: Milvang-Jensen, B.
last_name: Milvang-Jensen
- first_name: J.-W.
full_name: Kim, J.-W.
last_name: Kim
- first_name: J.
full_name: Stott, J.
last_name: Stott
- first_name: J.
full_name: Calhau, J.
last_name: Calhau
- first_name: H.
full_name: Nayyeri, H.
last_name: Nayyeri
- first_name: B.
full_name: Mobasher, B.
last_name: Mobasher
citation:
ama: 'Sobral D, Matthee JJ, Best PN, et al. CF-HiZELS, an ∼10 deg2 emission-line
survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions
at z = 0.8, 1.4 and 2.2 . Monthly Notices of the Royal Astronomical Society.
2015;451(3):2303-2323. doi:10.1093/mnras/stv1076'
apa: 'Sobral, D., Matthee, J. J., Best, P. N., Smail, I., Khostovan, A. A., Milvang-Jensen,
B., … Mobasher, B. (2015). CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic
follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and
2.2 . Monthly Notices of the Royal Astronomical Society. Oxford University
Press. https://doi.org/10.1093/mnras/stv1076'
chicago: 'Sobral, D., Jorryt J Matthee, P. N. Best, I. Smail, A. A. Khostovan, B.
Milvang-Jensen, J.-W. Kim, et al. “CF-HiZELS, an ∼10 Deg2 Emission-Line Survey
with Spectroscopic Follow-up: Hα, [O III] + Hβ and [O II] Luminosity Functions
at z = 0.8, 1.4 and 2.2 .” Monthly Notices of the Royal Astronomical Society.
Oxford University Press, 2015. https://doi.org/10.1093/mnras/stv1076.'
ieee: 'D. Sobral et al., “CF-HiZELS, an ∼10 deg2 emission-line survey with
spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z
= 0.8, 1.4 and 2.2 ,” Monthly Notices of the Royal Astronomical Society,
vol. 451, no. 3. Oxford University Press, pp. 2303–2323, 2015.'
ista: 'Sobral D, Matthee JJ, Best PN, Smail I, Khostovan AA, Milvang-Jensen B, Kim
J-W, Stott J, Calhau J, Nayyeri H, Mobasher B. 2015. CF-HiZELS, an ∼10 deg2 emission-line
survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions
at z = 0.8, 1.4 and 2.2 . Monthly Notices of the Royal Astronomical Society. 451(3),
2303–2323.'
mla: 'Sobral, D., et al. “CF-HiZELS, an ∼10 Deg2 Emission-Line Survey with Spectroscopic
Follow-up: Hα, [O III] + Hβ and [O II] Luminosity Functions at z = 0.8, 1.4 and
2.2 .” Monthly Notices of the Royal Astronomical Society, vol. 451, no.
3, Oxford University Press, 2015, pp. 2303–23, doi:10.1093/mnras/stv1076.'
short: D. Sobral, J.J. Matthee, P.N. Best, I. Smail, A.A. Khostovan, B. Milvang-Jensen,
J.-W. Kim, J. Stott, J. Calhau, H. Nayyeri, B. Mobasher, Monthly Notices of the
Royal Astronomical Society 451 (2015) 2303–2323.
date_created: 2022-07-14T09:02:22Z
date_published: 2015-08-11T00:00:00Z
date_updated: 2024-10-14T11:36:57Z
day: '11'
doi: 10.1093/mnras/stv1076
extern: '1'
external_id:
arxiv:
- '1502.06602'
intvolume: ' 451'
issue: '3'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: evolution'
- 'galaxies: formation'
- 'galaxies: luminosity function'
- mass function
- 'cosmology: observations'
- early Universe
- large-scale structure of Universe
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1502.06602
month: '08'
oa: 1
oa_version: Preprint
page: 2303-2323
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up:
Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and 2.2 '
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 451
year: '2015'
...
---
_id: '11581'
abstract:
- lang: eng
text: Using wide-field narrow-band surveys, we provide a new measurement of the
z = 6.6 Lymanα emitter (LAE) luminosity function (LF), which constraints the bright
end for the first time. We use a combination of archival narrow-band NB921 data
in UDS and new NB921 measurements in SA22 and COSMOS/UltraVISTA, all observed
with the Subaru telescope, with a total area of ∼5 deg2. We exclude lower redshift
interlopers by using broad-band optical and near-infrared photometry and also
exclude three supernovae with data split over multiple epochs. Combining the UDS
and COSMOS samples, we find no evolution of the bright end of the Lyα LF between
z = 5.7 and 6.6, which is supported by spectroscopic follow-up, and conclude that
sources with Himiko-like luminosity are not as rare as previously thought, with
number densities of ∼1.5 × 10−5 Mpc−3. Combined with our wide-field SA22 measurements,
our results indicate a non-Schechter-like bright end of the LF at z = 6.6 and
a different evolution of observed faint and bright LAEs, overcoming cosmic variance.
This differential evolution is also seen in the spectroscopic follow-up of UV-selected
galaxies and is now also confirmed for LAEs, and we argue that it may be an effect
of reionization. Using a toy model, we show that such differential evolution of
the LF is expected, since brighter sources are able to ionize their surroundings
earlier, such that Lyα photons are able to escape. Our targets are excellent candidates
for detailed follow-up studies and provide the possibility to give a unique view
on the earliest stages in the formation of galaxies and reionization process.
acknowledgement: "We thank the anonymous referee for the comments and suggestions
which have improved the quality of this work. We thank Masami Ouchi for his useful
comments on an earlier version of this paper. JM acknowledges the support of a Huygens
PhD fellowship from Leiden University and is thankful for the hospitality of the
Center for Astronomy and Astrophysics of the University of Lisbon where part of
this research has been done. DS acknowledges financial support from the Netherlands
Organization for Scientific research (NWO) through a Veni fellowship, from FCT through
a FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010)
and from FCT grant PEstOE/FIS/UI2751/2014. HR acknowledges support from the ERC
Advanced Investigator programme NewClusters 321271. We acknowledge the award of
ESO DDT time (294.A-5018) for providing the possibility of a timely publication
of this work.\r\nBased on observations with the Subaru Telescope (Programme IDs:
our observations: S14A-086; archival: S05B-027, S06A-025, S06B-010, S07A-013, S07B-008,
S08B-008 and S09A-017) and the W.M. Keck Observatory. The Subaru telescope is operated
by the National Astronomical Observatory of Japan. The W.M. Keck Observatory is
operated as a scientific partnership among the California Institute of Technology,
the University of California and the National Aeronautics and Space Administration.
Based on observations made with ESO Telescopes at the La Silla Paranal Observatory
under programme ID 294.A-5018. Based on observations obtained with MegaPrime/Megacam,
a joint project of CFHT and CEA/IRFU, at the Canada–France-Hawaii Telescope (CFHT)
which is operated by the National Research Council (NRC) of Canada, the Institut
National des Science de l’Univers of the Centre National de la Recherche Scientifique
(CNRS) of France, and the University of Hawaii. This work is based in part on data
products produced at Terapix available at the Canadian Astronomy Data Centre as
part of the CFHT Legacy Survey, a collaborative project of NRC and CNRS. Based on
data products from observations made with ESO Telescopes at the La Silla Paranal
Observatory under ESO programme ID 179.A-2005 and on data products produced by TERAPIX
and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium.\r\nIn
addition to the CFHT-LS and COSMOS-UltraVISTA surveys, we are grateful for the excellent
data sets from the UKIRT-DXS, SXDF and S-COSMOS survey teams, without these legacy
surveys, this research would have been impossible. We have benefited greatly from
the public available programming language PYTHON, including the NUMPY, MATPLOTLIB,
PYFITS, SCIPY and ASTROPY packages, the astronomical imaging tools SEXTRACTOR, SWARP
and SCAMP and the indispensable TOPCAT analysis tool (Taylor 2013)"
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: David
full_name: Sobral, David
last_name: Sobral
- first_name: Sérgio
full_name: Santos, Sérgio
last_name: Santos
- first_name: Huub
full_name: Röttgering, Huub
last_name: Röttgering
- first_name: Behnam
full_name: Darvish, Behnam
last_name: Darvish
- first_name: Bahram
full_name: Mobasher, Bahram
last_name: Mobasher
citation:
ama: 'Matthee JJ, Sobral D, Santos S, Röttgering H, Darvish B, Mobasher B. Identification
of the brightest Lyα emitters at z = 6.6: implications for the evolution of the
luminosity function in the reionization era. Monthly Notices of the Royal Astronomical
Society. 2015;451(1):400-417. doi:10.1093/mnras/stv947'
apa: 'Matthee, J. J., Sobral, D., Santos, S., Röttgering, H., Darvish, B., &
Mobasher, B. (2015). Identification of the brightest Lyα emitters at z = 6.6:
implications for the evolution of the luminosity function in the reionization
era. Monthly Notices of the Royal Astronomical Society. Oxford University
Press. https://doi.org/10.1093/mnras/stv947'
chicago: 'Matthee, Jorryt J, David Sobral, Sérgio Santos, Huub Röttgering, Behnam
Darvish, and Bahram Mobasher. “Identification of the Brightest Lyα Emitters at
z = 6.6: Implications for the Evolution of the Luminosity Function in the Reionization
Era.” Monthly Notices of the Royal Astronomical Society. Oxford University
Press, 2015. https://doi.org/10.1093/mnras/stv947.'
ieee: 'J. J. Matthee, D. Sobral, S. Santos, H. Röttgering, B. Darvish, and B. Mobasher,
“Identification of the brightest Lyα emitters at z = 6.6: implications for the
evolution of the luminosity function in the reionization era,” Monthly Notices
of the Royal Astronomical Society, vol. 451, no. 1. Oxford University Press,
pp. 400–417, 2015.'
ista: 'Matthee JJ, Sobral D, Santos S, Röttgering H, Darvish B, Mobasher B. 2015.
Identification of the brightest Lyα emitters at z = 6.6: implications for the
evolution of the luminosity function in the reionization era. Monthly Notices
of the Royal Astronomical Society. 451(1), 400–417.'
mla: 'Matthee, Jorryt J., et al. “Identification of the Brightest Lyα Emitters at
z = 6.6: Implications for the Evolution of the Luminosity Function in the Reionization
Era.” Monthly Notices of the Royal Astronomical Society, vol. 451, no.
1, Oxford University Press, 2015, pp. 400–17, doi:10.1093/mnras/stv947.'
short: J.J. Matthee, D. Sobral, S. Santos, H. Röttgering, B. Darvish, B. Mobasher,
Monthly Notices of the Royal Astronomical Society 451 (2015) 400–417.
date_created: 2022-07-14T11:57:03Z
date_published: 2015-07-21T00:00:00Z
date_updated: 2024-10-14T11:37:15Z
day: '21'
doi: 10.1093/mnras/stv947
extern: '1'
external_id:
arxiv:
- '1502.07355'
intvolume: ' 451'
issue: '1'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1502.07355
month: '07'
oa: 1
oa_version: Preprint
page: 400-417
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Identification of the brightest Lyα emitters at z = 6.6: implications for
the evolution of the luminosity function in the reionization era'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 451
year: '2015'
...
---
_id: '11668'
abstract:
- lang: eng
text: "We study multiple keyword sponsored search auctions with budgets. Each keyword
has multiple ad slots with a click-through rate. The bidders have additive valuations,
which are linear in the click-through rates, and budgets, which are restricting
their overall payments. Additionally, the number of slots per keyword assigned
to a bidder is bounded.\r\n\r\nWe show the following results: (1) We give the
first mechanism for multiple keywords, where click-through rates differ among
slots. Our mechanism is incentive compatible in expectation, individually rational
in expectation, and Pareto optimal. (2) We study the combinatorial setting, where
each bidder is only interested in a subset of the keywords. We give an incentive
compatible, individually rational, Pareto-optimal, and deterministic mechanism
for identical click-through rates. (3) We give an impossibility result for incentive
compatible, individually rational, Pareto-optimal, and deterministic mechanisms
for bidders with diminishing marginal valuations."
article_number: '2'
article_processing_charge: No
article_type: original
author:
- first_name: Riccardo
full_name: Colini-Baldeschi, Riccardo
last_name: Colini-Baldeschi
- first_name: Stefano
full_name: Leonardi, Stefano
last_name: Leonardi
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Martin
full_name: Starnberger, Martin
last_name: Starnberger
citation:
ama: Colini-Baldeschi R, Leonardi S, Henzinger M, Starnberger M. On multiple keyword
sponsored search auctions with budgets. ACM Transactions on Economics and Computation.
2015;4(1). doi:10.1145/2818357
apa: Colini-Baldeschi, R., Leonardi, S., Henzinger, M., & Starnberger, M. (2015).
On multiple keyword sponsored search auctions with budgets. ACM Transactions
on Economics and Computation. Association for Computing Machinery. https://doi.org/10.1145/2818357
chicago: Colini-Baldeschi, Riccardo, Stefano Leonardi, Monika Henzinger, and Martin
Starnberger. “On Multiple Keyword Sponsored Search Auctions with Budgets.” ACM
Transactions on Economics and Computation. Association for Computing Machinery,
2015. https://doi.org/10.1145/2818357.
ieee: R. Colini-Baldeschi, S. Leonardi, M. Henzinger, and M. Starnberger, “On multiple
keyword sponsored search auctions with budgets,” ACM Transactions on Economics
and Computation, vol. 4, no. 1. Association for Computing Machinery, 2015.
ista: Colini-Baldeschi R, Leonardi S, Henzinger M, Starnberger M. 2015. On multiple
keyword sponsored search auctions with budgets. ACM Transactions on Economics
and Computation. 4(1), 2.
mla: Colini-Baldeschi, Riccardo, et al. “On Multiple Keyword Sponsored Search Auctions
with Budgets.” ACM Transactions on Economics and Computation, vol. 4, no.
1, 2, Association for Computing Machinery, 2015, doi:10.1145/2818357.
short: R. Colini-Baldeschi, S. Leonardi, M. Henzinger, M. Starnberger, ACM Transactions
on Economics and Computation 4 (2015).
date_created: 2022-07-27T11:54:56Z
date_published: 2015-12-05T00:00:00Z
date_updated: 2024-11-06T12:06:41Z
day: '05'
doi: 10.1145/2818357
extern: '1'
intvolume: ' 4'
issue: '1'
keyword:
- Algorithms
- Economics
- Clinching ascending auction
- auctions with budgets
- Sponsored search auctions
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://eprints.cs.univie.ac.at/3510/
month: '12'
oa: 1
oa_version: Submitted Version
publication: ACM Transactions on Economics and Computation
publication_identifier:
eissn:
- 2167-8383
issn:
- 2167-8375
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: On multiple keyword sponsored search auctions with budgets
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 4
year: '2015'
...
---
_id: '11669'
abstract:
- lang: eng
text: We study individual rational, Pareto-optimal, and incentive compatible mechanisms
for auctions with heterogeneous items and budget limits. We consider settings
with multiunit demand and additive valuations. For single-dimensional valuations
we prove a positive result for randomized mechanisms, and a negative result for
deterministic mechanisms. While the positive result allows for private budgets,
the negative result is for public budgets. For multidimensional valuations and
public budgets we prove an impossibility result that applies to deterministic
and randomized mechanisms. Taken together this shows the power of randomization
in certain settings with heterogeneous items, but it also shows its limitations.
article_number: '4'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Paul
full_name: Dütting, Paul
last_name: Dütting
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Martin
full_name: Starnberger, Martin
last_name: Starnberger
citation:
ama: Dütting P, Henzinger M, Starnberger M. Auctions for heterogeneous items and
budget limits. ACM Transactions on Economics and Computation. 2015;4(1).
doi:10.1145/2818351
apa: Dütting, P., Henzinger, M., & Starnberger, M. (2015). Auctions for heterogeneous
items and budget limits. ACM Transactions on Economics and Computation.
Association for Computing Machinery. https://doi.org/10.1145/2818351
chicago: Dütting, Paul, Monika Henzinger, and Martin Starnberger. “Auctions for
Heterogeneous Items and Budget Limits.” ACM Transactions on Economics and Computation.
Association for Computing Machinery, 2015. https://doi.org/10.1145/2818351.
ieee: P. Dütting, M. Henzinger, and M. Starnberger, “Auctions for heterogeneous
items and budget limits,” ACM Transactions on Economics and Computation,
vol. 4, no. 1. Association for Computing Machinery, 2015.
ista: Dütting P, Henzinger M, Starnberger M. 2015. Auctions for heterogeneous items
and budget limits. ACM Transactions on Economics and Computation. 4(1), 4.
mla: Dütting, Paul, et al. “Auctions for Heterogeneous Items and Budget Limits.”
ACM Transactions on Economics and Computation, vol. 4, no. 1, 4, Association
for Computing Machinery, 2015, doi:10.1145/2818351.
short: P. Dütting, M. Henzinger, M. Starnberger, ACM Transactions on Economics and
Computation 4 (2015).
date_created: 2022-07-27T12:09:15Z
date_published: 2015-12-05T00:00:00Z
date_updated: 2024-11-06T12:06:53Z
day: '05'
doi: 10.1145/2818351
extern: '1'
external_id:
arxiv:
- '1209.6448'
intvolume: ' 4'
issue: '1'
keyword:
- Algorithmic game theory
- auction theory
- Clinching auction
- Pareto optimality
- Budget limits
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1209.6448
month: '12'
oa: 1
oa_version: Preprint
publication: ACM Transactions on Economics and Computation
publication_identifier:
eissn:
- 2167-8383
issn:
- 2167-8375
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: Auctions for heterogeneous items and budget limits
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 4
year: '2015'
...
---
_id: '11670'
abstract:
- lang: eng
text: Auctions are widely used on the Web. Applications range from sponsored search
to platforms such as eBay. In these and in many other applications the auctions
in use are single-/multi-item auctions with unit demand. The main drawback of
standard mechanisms for this type of auctions, such as VCG and GSP, is the limited
expressiveness that they offer to the bidders. The General Auction Mechanism (GAM)
of Aggarwal et al. [2009] takes a first step toward addressing the problem of
limited expressiveness by computing a bidder optimal, envy-free outcome for linear
utility functions with identical slopes and a single discontinuity per bidder-item
pair. We show that in many practical situations this does not suffice to adequately
model the preferences of the bidders, and we overcome this problem by presenting
the first mechanism for piecewise linear utility functions with nonidentical slopes
and multiple discontinuities. Our mechanism runs in polynomial time. Like GAM
it is incentive compatible for inputs that fulfill a certain nondegeneracy assumption,
but our requirement is more general than the requirement of GAM. For discontinuous
utility functions that are nondegenerate as well as for continuous utility functions
the outcome of our mechanism is a competitive equilibrium. We also show how our
mechanism can be used to compute approximately bidder optimal, envy-free outcomes
for a general class of continuous utility functions via piecewise linear approximation.
Finally, we prove hardness results for even more expressive settings.
acknowledgement: We would like to thank Veronika Loitzenbauer and the anonymous referees
for their valuable feedback.
article_number: '1'
article_processing_charge: No
article_type: original
author:
- first_name: Paul
full_name: Dütting, Paul
last_name: Dütting
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Ingmar
full_name: Weber, Ingmar
last_name: Weber
citation:
ama: Dütting P, Henzinger M, Weber I. An expressive mechanism for auctions on the
web. ACM Transactions on Economics and Computation. 2015;4(1). doi:10.1145/2716312
apa: Dütting, P., Henzinger, M., & Weber, I. (2015). An expressive mechanism
for auctions on the web. ACM Transactions on Economics and Computation.
Association for Computing Machinery. https://doi.org/10.1145/2716312
chicago: Dütting, Paul, Monika Henzinger, and Ingmar Weber. “An Expressive Mechanism
for Auctions on the Web.” ACM Transactions on Economics and Computation.
Association for Computing Machinery, 2015. https://doi.org/10.1145/2716312.
ieee: P. Dütting, M. Henzinger, and I. Weber, “An expressive mechanism for auctions
on the web,” ACM Transactions on Economics and Computation, vol. 4, no.
1. Association for Computing Machinery, 2015.
ista: Dütting P, Henzinger M, Weber I. 2015. An expressive mechanism for auctions
on the web. ACM Transactions on Economics and Computation. 4(1), 1.
mla: Dütting, Paul, et al. “An Expressive Mechanism for Auctions on the Web.” ACM
Transactions on Economics and Computation, vol. 4, no. 1, 1, Association for
Computing Machinery, 2015, doi:10.1145/2716312.
short: P. Dütting, M. Henzinger, I. Weber, ACM Transactions on Economics and Computation
4 (2015).
date_created: 2022-07-27T12:43:18Z
date_published: 2015-12-02T00:00:00Z
date_updated: 2024-11-06T12:07:05Z
day: '02'
doi: 10.1145/2716312
extern: '1'
intvolume: ' 4'
issue: '1'
keyword:
- Computational Mathematics
- Marketing
- Economics and Econometrics
- Statistics and Probability
- Computer Science (miscellaneous)
language:
- iso: eng
month: '12'
oa_version: None
publication: ACM Transactions on Economics and Computation
publication_identifier:
eissn:
- 2167-8383
issn:
- 2167-8375
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: An expressive mechanism for auctions on the web
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 4
year: '2015'
...
---
_id: '11773'
abstract:
- lang: eng
text: "Ad exchanges are an emerging platform for trading advertisement slots on
the web with billions of dollars revenue per year. Every time a user visits a
web page, the publisher of that web page can ask an ad exchange to auction off
the ad slots on this page to determine which advertisements are shown at which
price. Due to the high volume of traffic, ad networks typically act as mediators
for individual advertisers at ad exchanges. If multiple advertisers in an ad network
are interested in the ad slots of the same auction, the ad network might use a
“local” auction to resell the obtained ad slots among its advertisers.\r\n\r\nIn
this work we want to deepen the theoretical understanding of these new markets
by analyzing them from the viewpoint of combinatorial auctions. Prior work studied
mostly single-item auctions, while we allow the advertisers to express richer
preferences over multiple items. We develop a game-theoretic model for the entanglement
of the central auction at the ad exchange with the local auctions at the ad networks.
We consider the incentives of all three involved parties and suggest a three-party
competitive equilibrium, an extension of the Walrasian equilibrium that ensures
envy-freeness for all participants. We show the existence of a three-party competitive
equilibrium and a polynomial-time algorithm to find one for gross-substitute bidder
valuations."
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Oren
full_name: Ben-Zwi, Oren
last_name: Ben-Zwi
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Veronika
full_name: Loitzenbauer, Veronika
last_name: Loitzenbauer
citation:
ama: 'Ben-Zwi O, Henzinger M, Loitzenbauer V. Ad exchange: Envy-free auctions with
mediators. In: 11th International Conference on Web and Internet Economics.
Vol 9470. Springer Nature; 2015:104–117. doi:10.1007/978-3-662-48995-6_8'
apa: 'Ben-Zwi, O., Henzinger, M., & Loitzenbauer, V. (2015). Ad exchange: Envy-free
auctions with mediators. In 11th International Conference on Web and Internet
Economics (Vol. 9470, pp. 104–117). Amsterdam, Netherlands: Springer Nature.
https://doi.org/10.1007/978-3-662-48995-6_8'
chicago: 'Ben-Zwi, Oren, Monika Henzinger, and Veronika Loitzenbauer. “Ad Exchange:
Envy-Free Auctions with Mediators.” In 11th International Conference on Web
and Internet Economics, 9470:104–117. Springer Nature, 2015. https://doi.org/10.1007/978-3-662-48995-6_8.'
ieee: 'O. Ben-Zwi, M. Henzinger, and V. Loitzenbauer, “Ad exchange: Envy-free auctions
with mediators,” in 11th International Conference on Web and Internet Economics,
Amsterdam, Netherlands, 2015, vol. 9470, pp. 104–117.'
ista: 'Ben-Zwi O, Henzinger M, Loitzenbauer V. 2015. Ad exchange: Envy-free auctions
with mediators. 11th International Conference on Web and Internet Economics. WINE:
International Conference on Web and Internet Economics, LNCS, vol. 9470, 104–117.'
mla: 'Ben-Zwi, Oren, et al. “Ad Exchange: Envy-Free Auctions with Mediators.” 11th
International Conference on Web and Internet Economics, vol. 9470, Springer
Nature, 2015, pp. 104–117, doi:10.1007/978-3-662-48995-6_8.'
short: O. Ben-Zwi, M. Henzinger, V. Loitzenbauer, in:, 11th International Conference
on Web and Internet Economics, Springer Nature, 2015, pp. 104–117.
conference:
end_date: 2015-09-12
location: Amsterdam, Netherlands
name: 'WINE: International Conference on Web and Internet Economics'
start_date: 2015-09-09
date_created: 2022-08-08T13:33:56Z
date_published: 2015-12-09T00:00:00Z
date_updated: 2024-11-06T12:10:25Z
day: '09'
doi: 10.1007/978-3-662-48995-6_8
extern: '1'
external_id:
arxiv:
- '1604.05562'
intvolume: ' 9470'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.48550/arXiv.1604.05562
month: '12'
oa: 1
oa_version: Preprint
page: 104–117
publication: 11th International Conference on Web and Internet Economics
publication_identifier:
eisbn:
- '9783662489956'
isbn:
- '9783662489949'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Ad exchange: Envy-free auctions with mediators'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 9470
year: '2015'
...
---
_id: '11774'
abstract:
- lang: eng
text: "Combinatorial auctions (CA) are a well-studied area in algorithmic mechanism
design. However, contrary to the standard model, empirical studies suggest that
a bidder’s valuation often does not depend solely on the goods assigned to him.
For instance, in adwords auctions an advertiser might not want his ads to be displayed
next to his competitors’ ads. In this paper, we propose and analyze several natural
graph-theoretic models that incorporate such negative externalities, in which
bidders form a directed conflict graph with maximum out-degree Δ. We design algorithms
and truthful mechanisms for social welfare maximization that attain approximation
ratios depending on Δ.\r\n\r\nFor CA, our results are twofold: (1) A lottery that
eliminates conflicts by discarding bidders/items independent of the bids. It allows
to apply any truthful \U0001D6FC-approximation mechanism for conflict-free valuations
and yields an \U0001D4AA(\U0001D6FCΔ)-approximation mechanism. (2) For fractionally
sub-additive valuations, we design a rounding algorithm via a novel combination
of a semi-definite program and a linear program, resulting in a cone program;
the approximation ratio is \U0001D4AA((ΔloglogΔ)/logΔ). The ratios are almost
optimal given existing hardness results.\r\n\r\nFor adwords auctions, we present
several algorithms for the most relevant scenario when the number of items is
small. In particular, we design a truthful mechanism with approximation ratio
\U0001D45C(Δ) when the number of items is only logarithmic in the number of bidders."
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Yun Kuen
full_name: Cheung, Yun Kuen
last_name: Cheung
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Martin
full_name: Hoefer, Martin
last_name: Hoefer
- first_name: Martin
full_name: Starnberger, Martin
last_name: Starnberger
citation:
ama: 'Cheung YK, Henzinger M, Hoefer M, Starnberger M. Combinatorial auctions with
conflict-based externalities. In: 11th International Conference on Web and
Internet Economics. Vol 9470. Springer Nature; 2015:230–243. doi:10.1007/978-3-662-48995-6_17'
apa: 'Cheung, Y. K., Henzinger, M., Hoefer, M., & Starnberger, M. (2015). Combinatorial
auctions with conflict-based externalities. In 11th International Conference
on Web and Internet Economics (Vol. 9470, pp. 230–243). Amsterdam, Netherlands:
Springer Nature. https://doi.org/10.1007/978-3-662-48995-6_17'
chicago: Cheung, Yun Kuen, Monika Henzinger, Martin Hoefer, and Martin Starnberger.
“Combinatorial Auctions with Conflict-Based Externalities.” In 11th International
Conference on Web and Internet Economics, 9470:230–243. Springer Nature, 2015.
https://doi.org/10.1007/978-3-662-48995-6_17.
ieee: Y. K. Cheung, M. Henzinger, M. Hoefer, and M. Starnberger, “Combinatorial
auctions with conflict-based externalities,” in 11th International Conference
on Web and Internet Economics, Amsterdam, Netherlands, 2015, vol. 9470, pp.
230–243.
ista: 'Cheung YK, Henzinger M, Hoefer M, Starnberger M. 2015. Combinatorial auctions
with conflict-based externalities. 11th International Conference on Web and Internet
Economics. WINE: International Conference on Web and Internet Economics, LNCS,
vol. 9470, 230–243.'
mla: Cheung, Yun Kuen, et al. “Combinatorial Auctions with Conflict-Based Externalities.”
11th International Conference on Web and Internet Economics, vol. 9470,
Springer Nature, 2015, pp. 230–243, doi:10.1007/978-3-662-48995-6_17.
short: Y.K. Cheung, M. Henzinger, M. Hoefer, M. Starnberger, in:, 11th International
Conference on Web and Internet Economics, Springer Nature, 2015, pp. 230–243.
conference:
end_date: 2015-12-12
location: Amsterdam, Netherlands
name: 'WINE: International Conference on Web and Internet Economics'
start_date: 2015-12-09
date_created: 2022-08-08T13:54:32Z
date_published: 2015-12-09T00:00:00Z
date_updated: 2024-11-06T12:10:38Z
day: '09'
doi: 10.1007/978-3-662-48995-6_17
extern: '1'
external_id:
arxiv:
- '1509.09147'
intvolume: ' 9470'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.48550/arXiv.1509.09147
month: '12'
oa: 1
oa_version: Preprint
page: 230–243
publication: 11th International Conference on Web and Internet Economics
publication_identifier:
eisbn:
- '9783662489956'
isbn:
- '9783662489949'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Combinatorial auctions with conflict-based externalities
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 9470
year: '2015'
...
---
_id: '11785'
abstract:
- lang: eng
text: "Recently we presented the first algorithm for maintaining the set of nodes
reachable from a source node in a directed graph that is modified by edge deletions
with \U0001D45C(\U0001D45A\U0001D45B) total update time, where \U0001D45A is the
number of edges and \U0001D45B is the number of nodes in the graph [Henzinger
et al. STOC 2014]. The algorithm is a combination of several different algorithms,
each for a different \U0001D45A vs. \U0001D45B trade-off. For the case of \U0001D45A=Θ(\U0001D45B1.5)
the running time is \U0001D442(\U0001D45B2.47), just barely below \U0001D45A\U0001D45B=Θ(\U0001D45B2.5).
In this paper we simplify the previous algorithm using new algorithmic ideas and
achieve an improved running time of \U0001D442̃ (min(\U0001D45A7/6\U0001D45B2/3,\U0001D45A3/4\U0001D45B5/4+\U0001D45C(1),\U0001D45A2/3\U0001D45B4/3+\U0001D45C(1)+\U0001D45A3/7\U0001D45B12/7+\U0001D45C(1))).
This gives, e.g., \U0001D442(\U0001D45B2.36) for the notorious case \U0001D45A=Θ(\U0001D45B1.5).
We obtain the same upper bounds for the problem of maintaining the strongly connected
components of a directed graph undergoing edge deletions. Our algorithms are correct
with high probabililty against an oblivious adversary."
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Sebastian
full_name: Krinninger, Sebastian
last_name: Krinninger
- first_name: Danupon
full_name: Nanongkai, Danupon
last_name: Nanongkai
citation:
ama: 'Henzinger M, Krinninger S, Nanongkai D. Improved algorithms for decremental
single-source reachability on directed graphs. In: 42nd International Colloquium
on Automata, Languages and Programming. Vol 9134. Springer Nature; 2015:725-736.
doi:10.1007/978-3-662-47672-7_59'
apa: 'Henzinger, M., Krinninger, S., & Nanongkai, D. (2015). Improved algorithms
for decremental single-source reachability on directed graphs. In 42nd International
Colloquium on Automata, Languages and Programming (Vol. 9134, pp. 725–736).
Kyoto, Japan: Springer Nature. https://doi.org/10.1007/978-3-662-47672-7_59'
chicago: Henzinger, Monika, Sebastian Krinninger, and Danupon Nanongkai. “Improved
Algorithms for Decremental Single-Source Reachability on Directed Graphs.” In
42nd International Colloquium on Automata, Languages and Programming, 9134:725–36.
Springer Nature, 2015. https://doi.org/10.1007/978-3-662-47672-7_59.
ieee: M. Henzinger, S. Krinninger, and D. Nanongkai, “Improved algorithms for decremental
single-source reachability on directed graphs,” in 42nd International Colloquium
on Automata, Languages and Programming, Kyoto, Japan, 2015, vol. 9134, pp.
725–736.
ista: 'Henzinger M, Krinninger S, Nanongkai D. 2015. Improved algorithms for decremental
single-source reachability on directed graphs. 42nd International Colloquium on
Automata, Languages and Programming. ICALP: International Colloquium on Automata,
Languages, and Programming, LNCS, vol. 9134, 725–736.'
mla: Henzinger, Monika, et al. “Improved Algorithms for Decremental Single-Source
Reachability on Directed Graphs.” 42nd International Colloquium on Automata,
Languages and Programming, vol. 9134, Springer Nature, 2015, pp. 725–36, doi:10.1007/978-3-662-47672-7_59.
short: M. Henzinger, S. Krinninger, D. Nanongkai, in:, 42nd International Colloquium
on Automata, Languages and Programming, Springer Nature, 2015, pp. 725–736.
conference:
end_date: 2015-07-10
location: Kyoto, Japan
name: 'ICALP: International Colloquium on Automata, Languages, and Programming'
start_date: 2015-07-06
date_created: 2022-08-11T08:51:32Z
date_published: 2015-01-01T00:00:00Z
date_updated: 2024-11-06T12:10:50Z
day: '01'
doi: 10.1007/978-3-662-47672-7_59
extern: '1'
external_id:
arxiv:
- '1612.03856'
intvolume: ' 9134'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1612.03856
month: '01'
oa: 1
oa_version: Preprint
page: 725 - 736
publication: 42nd International Colloquium on Automata, Languages and Programming
publication_identifier:
isbn:
- '9783662476710'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Improved algorithms for decremental single-source reachability on directed
graphs
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 9134
year: '2015'
...
---
_id: '11786'
abstract:
- lang: eng
text: "In this paper, we develop a dynamic version of the primal-dual method for
optimization problems, and apply it to obtain the following results. (1) For the
dynamic set-cover problem, we maintain an \U0001D442(\U0001D4532)-approximately
optimal solution in \U0001D442(\U0001D453⋅log(\U0001D45A+\U0001D45B)) amortized
update time, where \U0001D453 is the maximum “frequency” of an element, \U0001D45B
is the number of sets, and \U0001D45A is the maximum number of elements in the
universe at any point in time. (2) For the dynamic \U0001D44F-matching problem,
we maintain an \U0001D442(1)-approximately optimal solution in \U0001D442(log3\U0001D45B)
amortized update time, where \U0001D45B is the number of nodes in the graph."
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Sayan
full_name: Bhattacharya, Sayan
last_name: Bhattacharya
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Giuseppe F.
full_name: Italiano, Giuseppe F.
last_name: Italiano
citation:
ama: 'Bhattacharya S, Henzinger M, Italiano GF. Design of dynamic algorithms via
primal-dual method. In: 42nd International Colloquium on Automata, Languages
and Programming. Vol 9134. Springer Nature; 2015:206-218. doi:10.1007/978-3-662-47672-7_17'
apa: 'Bhattacharya, S., Henzinger, M., & Italiano, G. F. (2015). Design of dynamic
algorithms via primal-dual method. In 42nd International Colloquium on Automata,
Languages and Programming (Vol. 9134, pp. 206–218). Kyoto, Japan: Springer
Nature. https://doi.org/10.1007/978-3-662-47672-7_17'
chicago: Bhattacharya, Sayan, Monika Henzinger, and Giuseppe F. Italiano. “Design
of Dynamic Algorithms via Primal-Dual Method.” In 42nd International Colloquium
on Automata, Languages and Programming, 9134:206–18. Springer Nature, 2015.
https://doi.org/10.1007/978-3-662-47672-7_17.
ieee: S. Bhattacharya, M. Henzinger, and G. F. Italiano, “Design of dynamic algorithms
via primal-dual method,” in 42nd International Colloquium on Automata, Languages
and Programming, Kyoto, Japan, 2015, vol. 9134, pp. 206–218.
ista: 'Bhattacharya S, Henzinger M, Italiano GF. 2015. Design of dynamic algorithms
via primal-dual method. 42nd International Colloquium on Automata, Languages and
Programming. ICALP: International Colloquium on Automata, Languages, and Programming,
LNCS, vol. 9134, 206–218.'
mla: Bhattacharya, Sayan, et al. “Design of Dynamic Algorithms via Primal-Dual Method.”
42nd International Colloquium on Automata, Languages and Programming, vol.
9134, Springer Nature, 2015, pp. 206–18, doi:10.1007/978-3-662-47672-7_17.
short: S. Bhattacharya, M. Henzinger, G.F. Italiano, in:, 42nd International Colloquium
on Automata, Languages and Programming, Springer Nature, 2015, pp. 206–218.
conference:
end_date: 2015-07-10
location: Kyoto, Japan
name: 'ICALP: International Colloquium on Automata, Languages, and Programming'
start_date: 2015-07-06
date_created: 2022-08-11T09:28:49Z
date_published: 2015-01-01T00:00:00Z
date_updated: 2024-11-06T12:11:02Z
day: '01'
doi: 10.1007/978-3-662-47672-7_17
extern: '1'
external_id:
arxiv:
- '1604.05337'
intvolume: ' 9134'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1604.05337
month: '01'
oa: 1
oa_version: Preprint
page: 206 - 218
publication: 42nd International Colloquium on Automata, Languages and Programming
publication_identifier:
isbn:
- '9783662476710'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Design of dynamic algorithms via primal-dual method
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 9134
year: '2015'
...
---
_id: '11787'
abstract:
- lang: eng
text: "We present faster algorithms for computing the 2-edge and 2-vertex strongly
connected components of a directed graph. While in undirected graphs the 2-edge
and 2-vertex connected components can be found in linear time, in directed graphs
with m edges and n vertices only rather simple O(m n)-time algorithms were known.
We use a hierarchical sparsification technique to obtain algorithms that run in
time \U0001D442(\U0001D45B2). For 2-edge strongly connected components our algorithm
gives the first running time improvement in 20 years. Additionally we present
an \U0001D442(\U0001D45A2/log\U0001D45B)-time algorithm for 2-edge strongly connected
components, and thus improve over the O(m n) running time also when \U0001D45A=\U0001D442(\U0001D45B).
Our approach extends to k-edge and k-vertex strongly connected components for
any constant k with a running time of \U0001D442(\U0001D45B2log\U0001D45B) for
k-edge-connectivity and \U0001D442(\U0001D45B3) for k-vertex-connectivity."
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Sebastian
full_name: Krinninger, Sebastian
last_name: Krinninger
- first_name: Veronika
full_name: Loitzenbauer, Veronika
last_name: Loitzenbauer
citation:
ama: 'Henzinger M, Krinninger S, Loitzenbauer V. Finding 2-edge and 2-vertex strongly
connected components in quadratic time. In: 2nd International Colloquium on
Automata, Languages and Programming. Vol 9134. Springer Nature; 2015:713-724.
doi:10.1007/978-3-662-47672-7_58'
apa: 'Henzinger, M., Krinninger, S., & Loitzenbauer, V. (2015). Finding 2-edge
and 2-vertex strongly connected components in quadratic time. In 2nd International
Colloquium on Automata, Languages and Programming (Vol. 9134, pp. 713–724).
Kyoto, Japan: Springer Nature. https://doi.org/10.1007/978-3-662-47672-7_58'
chicago: Henzinger, Monika, Sebastian Krinninger, and Veronika Loitzenbauer. “Finding
2-Edge and 2-Vertex Strongly Connected Components in Quadratic Time.” In 2nd
International Colloquium on Automata, Languages and Programming, 9134:713–24.
Springer Nature, 2015. https://doi.org/10.1007/978-3-662-47672-7_58.
ieee: M. Henzinger, S. Krinninger, and V. Loitzenbauer, “Finding 2-edge and 2-vertex
strongly connected components in quadratic time,” in 2nd International Colloquium
on Automata, Languages and Programming, Kyoto, Japan, 2015, vol. 9134, pp.
713–724.
ista: 'Henzinger M, Krinninger S, Loitzenbauer V. 2015. Finding 2-edge and 2-vertex
strongly connected components in quadratic time. 2nd International Colloquium
on Automata, Languages and Programming. ICALP: International Colloquium on Automata,
Languages, and Programming, LNCS, vol. 9134, 713–724.'
mla: Henzinger, Monika, et al. “Finding 2-Edge and 2-Vertex Strongly Connected Components
in Quadratic Time.” 2nd International Colloquium on Automata, Languages and
Programming, vol. 9134, Springer Nature, 2015, pp. 713–24, doi:10.1007/978-3-662-47672-7_58.
short: M. Henzinger, S. Krinninger, V. Loitzenbauer, in:, 2nd International Colloquium
on Automata, Languages and Programming, Springer Nature, 2015, pp. 713–724.
conference:
end_date: 2015-07-10
location: Kyoto, Japan
name: 'ICALP: International Colloquium on Automata, Languages, and Programming'
start_date: 2015-07-06
date_created: 2022-08-11T09:38:34Z
date_published: 2015-07-06T00:00:00Z
date_updated: 2024-11-06T12:11:13Z
day: '06'
doi: 10.1007/978-3-662-47672-7_58
extern: '1'
external_id:
arxiv:
- '1412.6466'
intvolume: ' 9134'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1412.6466
month: '07'
oa: 1
oa_version: Preprint
page: 713 - 724
publication: 2nd International Colloquium on Automata, Languages and Programming
publication_identifier:
isbn:
- '9783662476710'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Finding 2-edge and 2-vertex strongly connected components in quadratic time
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 9134
year: '2015'
...
---
_id: '11788'
abstract:
- lang: eng
text: "Ad exchanges are becoming an increasingly popular way to sell advertisement
slots on the internet. An ad exchange is basically a spot market for ad impressions.
A publisher who has already signed contracts reserving advertisement impressions
on his pages can choose between assigning a new ad impression for a new page view
to a contracted advertiser or to sell it at an ad exchange. This leads to an online
revenue maximization problem for the publisher. Given a new impression to sell
decide whether (a) to assign it to a contracted advertiser and if so to which
one or (b) to sell it at the ad exchange and if so at which reserve price. We
make no assumptions about the distribution of the advertiser valuations that participate
in the ad exchange and show that there exists a simple primal-dual based online
algorithm, whose lower bound for the revenue converges to \U0001D445\U0001D434\U0001D437\U0001D44B+\U0001D445\U0001D434(1−1/\U0001D452),
where \U0001D445\U0001D434\U0001D437\U0001D44B is the revenue that the optimum
algorithm achieves from the ad exchange and \U0001D445\U0001D434 is the revenue
that the optimum algorithm achieves from the contracted advertisers."
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Wolfgang
full_name: Dvořák, Wolfgang
last_name: Dvořák
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
citation:
ama: 'Dvořák W, Henzinger M. Online ad assignment with an ad exchange. In: 12th
International Workshop of Approximation and Online Algorithms. Vol 8952. Springer
Nature; 2015:156–167. doi:10.1007/978-3-319-18263-6_14'
apa: 'Dvořák, W., & Henzinger, M. (2015). Online ad assignment with an ad exchange.
In 12th International Workshop of Approximation and Online Algorithms (Vol.
8952, pp. 156–167). Wroclaw, Poland: Springer Nature. https://doi.org/10.1007/978-3-319-18263-6_14'
chicago: Dvořák, Wolfgang, and Monika Henzinger. “Online Ad Assignment with an Ad
Exchange.” In 12th International Workshop of Approximation and Online Algorithms,
8952:156–167. Springer Nature, 2015. https://doi.org/10.1007/978-3-319-18263-6_14.
ieee: W. Dvořák and M. Henzinger, “Online ad assignment with an ad exchange,” in
12th International Workshop of Approximation and Online Algorithms, Wroclaw,
Poland, 2015, vol. 8952, pp. 156–167.
ista: 'Dvořák W, Henzinger M. 2015. Online ad assignment with an ad exchange. 12th
International Workshop of Approximation and Online Algorithms. WAOA: International
Workshop on Approximation and Online Algorithms, LNCS, vol. 8952, 156–167.'
mla: Dvořák, Wolfgang, and Monika Henzinger. “Online Ad Assignment with an Ad Exchange.”
12th International Workshop of Approximation and Online Algorithms, vol.
8952, Springer Nature, 2015, pp. 156–167, doi:10.1007/978-3-319-18263-6_14.
short: W. Dvořák, M. Henzinger, in:, 12th International Workshop of Approximation
and Online Algorithms, Springer Nature, 2015, pp. 156–167.
conference:
end_date: 2014-09-12
location: Wroclaw, Poland
name: 'WAOA: International Workshop on Approximation and Online Algorithms'
start_date: 2014-09-11
date_created: 2022-08-11T09:43:32Z
date_published: 2015-01-01T00:00:00Z
date_updated: 2024-11-06T12:11:24Z
day: '01'
doi: 10.1007/978-3-319-18263-6_14
extern: '1'
external_id:
arxiv:
- '1604.05603'
intvolume: ' 8952'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1604.05603
month: '01'
oa: 1
oa_version: Preprint
page: 156–167
publication: 12th International Workshop of Approximation and Online Algorithms
publication_identifier:
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Online ad assignment with an ad exchange
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 8952
year: '2015'
...
---
_id: '11837'
abstract:
- lang: eng
text: "Online social networks allow the collection of large amounts of data about
the influence between users connected by a friendship-like relationship. When
distributing items among agents forming a social network, this information allows
us to exploit network externalities that each agent receives from his neighbors
that get the same item. In this paper we consider Friends-of-Friends (2-hop) network
externalities, i.e., externalities that not only depend on the neighbors that
get the same item but also on neighbors of neighbors. For these externalities
we study a setting where multiple different items are assigned to unit-demand
agents. Specifically, we study the problem of welfare maximization under different
types of externality functions. Let n be the number of agents and m be the number
of items. Our contributions are the following: (1) We show that welfare maximization
is APX-hard; we show that even for step functions with 2-hop (and also with 1-hop)
externalities it is NP-hard to approximate social welfare better than (1-1/e).
(2) On the positive side we present (i) an O(sqrt n)-approximation algorithm for
general concave externality functions,\r\n(ii) an O(\\log m)-approximation algorithm
for linear externality functions, and (iii) an (1-1/e)\\frac{1}{6}-approximation
algorithm for 2-hop step function externalities. We also improve the result from
[6] for 1-hop step function externalities by giving a (1-1/e)/2-approximation
algorithm."
alternative_title:
- LIPIcs
article_processing_charge: No
author:
- first_name: Sayan
full_name: Bhattacharya, Sayan
last_name: Bhattacharya
- first_name: Wolfgang
full_name: Dvorák, Wolfgang
last_name: Dvorák
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: ' Martin'
full_name: Starnberger, Martin
last_name: Starnberger
citation:
ama: 'Bhattacharya S, Dvorák W, Henzinger M, Starnberger Martin. Welfare maximization
with friends-of-friends network externalities. In: 32nd International Symposium
on Theoretical Aspects of Computer Science. Vol 30. Schloss Dagstuhl - Leibniz-Zentrum
für Informatik; 2015:90-102. doi:10.4230/LIPICS.STACS.2015.90'
apa: 'Bhattacharya, S., Dvorák, W., Henzinger, M., & Starnberger, Martin. (2015).
Welfare maximization with friends-of-friends network externalities. In 32nd
International Symposium on Theoretical Aspects of Computer Science (Vol. 30,
pp. 90–102). Garching, Germany: Schloss Dagstuhl - Leibniz-Zentrum für Informatik.
https://doi.org/10.4230/LIPICS.STACS.2015.90'
chicago: Bhattacharya, Sayan, Wolfgang Dvorák, Monika Henzinger, and Martin Starnberger.
“Welfare Maximization with Friends-of-Friends Network Externalities.” In 32nd
International Symposium on Theoretical Aspects of Computer Science, 30:90–102.
Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2015. https://doi.org/10.4230/LIPICS.STACS.2015.90.
ieee: S. Bhattacharya, W. Dvorák, M. Henzinger, and Martin Starnberger, “Welfare
maximization with friends-of-friends network externalities,” in 32nd International
Symposium on Theoretical Aspects of Computer Science, Garching, Germany, 2015,
vol. 30, pp. 90–102.
ista: 'Bhattacharya S, Dvorák W, Henzinger M, Starnberger Martin. 2015. Welfare
maximization with friends-of-friends network externalities. 32nd International
Symposium on Theoretical Aspects of Computer Science. STACS: Symposium on Theoretical
Aspects of Computer Science, LIPIcs, vol. 30, 90–102.'
mla: Bhattacharya, Sayan, et al. “Welfare Maximization with Friends-of-Friends Network
Externalities.” 32nd International Symposium on Theoretical Aspects of Computer
Science, vol. 30, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2015,
pp. 90–102, doi:10.4230/LIPICS.STACS.2015.90.
short: S. Bhattacharya, W. Dvorák, M. Henzinger, Martin Starnberger, in:, 32nd
International Symposium on Theoretical Aspects of Computer Science, Schloss Dagstuhl
- Leibniz-Zentrum für Informatik, 2015, pp. 90–102.
conference:
end_date: 2015-03-07
location: Garching, Germany
name: 'STACS: Symposium on Theoretical Aspects of Computer Science'
start_date: 2015-03-04
date_created: 2022-08-12T11:39:40Z
date_published: 2015-02-26T00:00:00Z
date_updated: 2024-11-06T12:24:23Z
day: '26'
doi: 10.4230/LIPICS.STACS.2015.90
extern: '1'
intvolume: ' 30'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.4230/LIPICS.STACS.2015.90
month: '02'
oa: 1
oa_version: Published Version
page: 90-102
publication: 32nd International Symposium on Theoretical Aspects of Computer Science
publication_identifier:
isbn:
- 978-3-939897-78-1
issn:
- 1868-8969
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
related_material:
record:
- id: '11903'
relation: later_version
status: public
scopus_import: '1'
status: public
title: Welfare maximization with friends-of-friends network externalities
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 30
year: '2015'
...
---
_id: '11845'
abstract:
- lang: eng
text: "Phylogenetic diversity (PD) is a measure of biodiversity based on the evolutionary
history of species. Here, we discuss several optimization problems related to
the use of PD, and the more general measure split diversity (SD), in conservation
prioritization.\r\nDepending on the conservation goal and the information available
about species, one can construct optimization routines that incorporate various
conservation constraints. We demonstrate how this information can be used to select
sets of species for conservation action. Specifically, we discuss the use of species'
geographic distributions, the choice of candidates under economic pressure, and
the use of predator–prey interactions between the species in a community to define
viability constraints.\r\nDespite such optimization problems falling into the
area of NP hard problems, it is possible to solve them in a reasonable amount
of time using integer programming. We apply integer linear programming to a variety
of models for conservation prioritization that incorporate the SD measure.\r\nWe
exemplarily show the results for two data sets: the Cape region of South Africa
and a Caribbean coral reef community. Finally, we provide user-friendly software
at http://www.cibiv.at/software/pda."
article_processing_charge: No
article_type: original
author:
- first_name: Olga
full_name: Chernomor, Olga
last_name: Chernomor
- first_name: Bui Quang
full_name: Minh, Bui Quang
last_name: Minh
- first_name: Félix
full_name: Forest, Félix
last_name: Forest
- first_name: Steffen
full_name: Klaere, Steffen
last_name: Klaere
- first_name: Travis
full_name: Ingram, Travis
last_name: Ingram
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Arndt
full_name: von Haeseler, Arndt
last_name: von Haeseler
citation:
ama: Chernomor O, Minh BQ, Forest F, et al. Split diversity in constrained conservation
prioritization using integer linear programming. Methods in Ecology and Evolution.
2015;6(1):83-91. doi:10.1111/2041-210x.12299
apa: Chernomor, O., Minh, B. Q., Forest, F., Klaere, S., Ingram, T., Henzinger,
M., & von Haeseler, A. (2015). Split diversity in constrained conservation
prioritization using integer linear programming. Methods in Ecology and Evolution.
Wiley. https://doi.org/10.1111/2041-210x.12299
chicago: Chernomor, Olga, Bui Quang Minh, Félix Forest, Steffen Klaere, Travis Ingram,
Monika Henzinger, and Arndt von Haeseler. “Split Diversity in Constrained Conservation
Prioritization Using Integer Linear Programming.” Methods in Ecology and Evolution.
Wiley, 2015. https://doi.org/10.1111/2041-210x.12299.
ieee: O. Chernomor et al., “Split diversity in constrained conservation prioritization
using integer linear programming,” Methods in Ecology and Evolution, vol.
6, no. 1. Wiley, pp. 83–91, 2015.
ista: Chernomor O, Minh BQ, Forest F, Klaere S, Ingram T, Henzinger M, von Haeseler
A. 2015. Split diversity in constrained conservation prioritization using integer
linear programming. Methods in Ecology and Evolution. 6(1), 83–91.
mla: Chernomor, Olga, et al. “Split Diversity in Constrained Conservation Prioritization
Using Integer Linear Programming.” Methods in Ecology and Evolution, vol.
6, no. 1, Wiley, 2015, pp. 83–91, doi:10.1111/2041-210x.12299.
short: O. Chernomor, B.Q. Minh, F. Forest, S. Klaere, T. Ingram, M. Henzinger, A.
von Haeseler, Methods in Ecology and Evolution 6 (2015) 83–91.
date_created: 2022-08-16T06:43:49Z
date_published: 2015-01-01T00:00:00Z
date_updated: 2024-11-06T12:16:55Z
day: '01'
ddc:
- '570'
doi: 10.1111/2041-210x.12299
extern: '1'
external_id:
pmid:
- '25893087'
file:
- access_level: open_access
checksum: 880e78f09f0ac99cb351c48dc97623b6
content_type: application/pdf
creator: asandaue
date_created: 2022-08-16T06:52:53Z
date_updated: 2022-08-16T06:52:53Z
file_id: '11846'
file_name: 2015_MethodsInEcologyAndEvolutionChernomor.pdf
file_size: 411415
relation: main_file
success: 1
file_date_updated: 2022-08-16T06:52:53Z
has_accepted_license: '1'
intvolume: ' 6'
issue: '1'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '01'
oa: 1
oa_version: Published Version
page: 83-91
pmid: 1
publication: Methods in Ecology and Evolution
publication_identifier:
eissn:
- 2041-210X
publication_status: published
publisher: Wiley
quality_controlled: '1'
scopus_import: '1'
status: public
title: Split diversity in constrained conservation prioritization using integer linear
programming
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 6
year: '2015'
...
---
_id: '11868'
abstract:
- lang: eng
text: "Consider the following Online Boolean Matrix-Vector Multiplication problem:
We are given an n x n matrix M and will receive n column-vectors of size n, denoted
by v1, ..., vn, one by one. After seeing each vector vi, we have to output the
product Mvi before we can see the next vector. A naive algorithm can solve this
problem using O(n3) time in total, and its running time can be slightly improved
to O(n3/log2 n) [Williams SODA'07]. We show that a conjecture that there is no
truly subcubic (O(n3-ε)) time algorithm for this problem can be used to exhibit
the underlying polynomial time hardness shared by many dynamic problems. For a
number of problems, such as subgraph connectivity, Pagh's problem, d-failure connectivity,
decremental single-source shortest paths, and decremental transitive closure,
this conjecture implies tight hardness results. Thus, proving or disproving this
conjecture will be very interesting as it will either imply several tight unconditional
lower bounds or break through a common barrier that blocks progress with these
problems. This conjecture might also be considered as strong evidence against
any further improvement for these problems since refuting it will imply a major
breakthrough for combinatorial Boolean matrix multiplication and other long-standing
problems if the term \"combinatorial algorithms\" is interpreted as \"Strassen-like
algorithms\" [Ballard et al. SPAA'11].\r\n\r\nThe conjecture also leads to hardness
results for problems that were previously based on diverse problems and conjectures
-- such as 3SUM, combinatorial Boolean matrix multiplication, triangle detection,
and multiphase -- thus providing a uniform way to prove polynomial hardness results
for dynamic algorithms; some of the new proofs are also simpler or even become
trivial. The conjecture also leads to stronger and new, non-trivial, hardness
results, e.g., for the fully-dynamic densest subgraph and diameter problems."
article_number: 21-30
article_processing_charge: No
arxiv: 1
author:
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Sebastian
full_name: Krinninger, Sebastian
last_name: Krinninger
- first_name: Danupon
full_name: Nanongkai, Danupon
last_name: Nanongkai
- first_name: Thatchaphol
full_name: Saranurak, Thatchaphol
last_name: Saranurak
citation:
ama: 'Henzinger M, Krinninger S, Nanongkai D, Saranurak T. Unifying and strengthening
hardness for dynamic problems via the online matrix-vector multiplication conjecture.
In: 47th Annual ACM Symposium on Theory of Computing. Association for Computing
Machinery; 2015. doi:10.1145/2746539.2746609'
apa: 'Henzinger, M., Krinninger, S., Nanongkai, D., & Saranurak, T. (2015).
Unifying and strengthening hardness for dynamic problems via the online matrix-vector
multiplication conjecture. In 47th Annual ACM Symposium on Theory of Computing.
Portland, OR, United States: Association for Computing Machinery. https://doi.org/10.1145/2746539.2746609'
chicago: Henzinger, Monika, Sebastian Krinninger, Danupon Nanongkai, and Thatchaphol
Saranurak. “Unifying and Strengthening Hardness for Dynamic Problems via the Online
Matrix-Vector Multiplication Conjecture.” In 47th Annual ACM Symposium on Theory
of Computing. Association for Computing Machinery, 2015. https://doi.org/10.1145/2746539.2746609.
ieee: M. Henzinger, S. Krinninger, D. Nanongkai, and T. Saranurak, “Unifying and
strengthening hardness for dynamic problems via the online matrix-vector multiplication
conjecture,” in 47th Annual ACM Symposium on Theory of Computing, Portland,
OR, United States, 2015.
ista: 'Henzinger M, Krinninger S, Nanongkai D, Saranurak T. 2015. Unifying and strengthening
hardness for dynamic problems via the online matrix-vector multiplication conjecture.
47th Annual ACM Symposium on Theory of Computing. STOC: Symposium on Theory of
Computing, 21–30.'
mla: Henzinger, Monika, et al. “Unifying and Strengthening Hardness for Dynamic
Problems via the Online Matrix-Vector Multiplication Conjecture.” 47th Annual
ACM Symposium on Theory of Computing, 21–30, Association for Computing Machinery,
2015, doi:10.1145/2746539.2746609.
short: M. Henzinger, S. Krinninger, D. Nanongkai, T. Saranurak, in:, 47th Annual
ACM Symposium on Theory of Computing, Association for Computing Machinery, 2015.
conference:
end_date: 2015-06-17
location: Portland, OR, United States
name: 'STOC: Symposium on Theory of Computing'
start_date: 2015-06-14
date_created: 2022-08-16T09:31:21Z
date_published: 2015-06-14T00:00:00Z
date_updated: 2024-11-06T12:19:48Z
day: '14'
doi: 10.1145/2746539.2746609
extern: '1'
external_id:
arxiv:
- '1511.06773'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1511.06773
month: '06'
oa: 1
oa_version: Preprint
publication: 47th Annual ACM Symposium on Theory of Computing
publication_identifier:
isbn:
- 978-145033536-2
issn:
- '0737.8017'
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: Unifying and strengthening hardness for dynamic problems via the online matrix-vector
multiplication conjecture
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...
---
_id: '11869'
abstract:
- lang: eng
text: "While in many graph mining applications it is crucial to handle a stream
of updates efficiently in terms of both time and space, not much was known about
achieving such type of algorithm. In this paper we study this issue for a problem
which lies at the core of many graph mining applications called densest subgraph
problem. We develop an algorithm that achieves time- and space-efficiency for
this problem simultaneously. It is one of the first of its kind for graph problems
to the best of our knowledge.\r\n\r\nGiven an input graph, the densest subgraph
is the subgraph that maximizes the ratio between the number of edges and the number
of nodes. For any ε>0, our algorithm can, with high probability, maintain a (4+ε)-approximate
solution under edge insertions and deletions using ~O(n) space and ~O(1) amortized
time per update; here, $n$ is the number of nodes in the graph and ~O hides the
O(polylog_{1+ε} n) term. The approximation ratio can be improved to (2+ε) with
more time. It can be extended to a (2+ε)-approximation sublinear-time algorithm
and a distributed-streaming algorithm. Our algorithm is the first streaming algorithm
that can maintain the densest subgraph in one pass. Prior to this, no algorithm
could do so even in the special case of an incremental stream and even when there
is no time restriction. The previously best algorithm in this setting required
O(log n) passes [BahmaniKV12]. The space required by our algorithm is tight up
to a polylogarithmic factor."
article_processing_charge: No
arxiv: 1
author:
- first_name: Sayan
full_name: Bhattacharya, Sayan
last_name: Bhattacharya
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Danupon
full_name: Nanongkai, Danupon
last_name: Nanongkai
- first_name: Charalampos
full_name: Tsourakakis, Charalampos
last_name: Tsourakakis
citation:
ama: 'Bhattacharya S, Henzinger M, Nanongkai D, Tsourakakis C. Space- and time-efficient
algorithm for maintaining dense subgraphs on one-pass dynamic streams. In: 47th
Annual ACM Symposium on Theory of Computing. Association for Computing Machinery;
2015:173-182. doi:10.1145/2746539.2746592'
apa: 'Bhattacharya, S., Henzinger, M., Nanongkai, D., & Tsourakakis, C. (2015).
Space- and time-efficient algorithm for maintaining dense subgraphs on one-pass
dynamic streams. In 47th Annual ACM Symposium on Theory of Computing (pp.
173–182). Portland, OR, United States: Association for Computing Machinery. https://doi.org/10.1145/2746539.2746592'
chicago: Bhattacharya, Sayan, Monika Henzinger, Danupon Nanongkai, and Charalampos
Tsourakakis. “Space- and Time-Efficient Algorithm for Maintaining Dense Subgraphs
on One-Pass Dynamic Streams.” In 47th Annual ACM Symposium on Theory of Computing,
173–82. Association for Computing Machinery, 2015. https://doi.org/10.1145/2746539.2746592.
ieee: S. Bhattacharya, M. Henzinger, D. Nanongkai, and C. Tsourakakis, “Space- and
time-efficient algorithm for maintaining dense subgraphs on one-pass dynamic streams,”
in 47th Annual ACM Symposium on Theory of Computing, Portland, OR, United
States, 2015, pp. 173–182.
ista: 'Bhattacharya S, Henzinger M, Nanongkai D, Tsourakakis C. 2015. Space- and
time-efficient algorithm for maintaining dense subgraphs on one-pass dynamic streams.
47th Annual ACM Symposium on Theory of Computing. STOC: Symposium on Theory of
Computing, 173–182.'
mla: Bhattacharya, Sayan, et al. “Space- and Time-Efficient Algorithm for Maintaining
Dense Subgraphs on One-Pass Dynamic Streams.” 47th Annual ACM Symposium on
Theory of Computing, Association for Computing Machinery, 2015, pp. 173–82,
doi:10.1145/2746539.2746592.
short: S. Bhattacharya, M. Henzinger, D. Nanongkai, C. Tsourakakis, in:, 47th Annual
ACM Symposium on Theory of Computing, Association for Computing Machinery, 2015,
pp. 173–182.
conference:
end_date: 2015-06-17
location: Portland, OR, United States
name: 'STOC: Symposium on Theory of Computing'
start_date: 2015-06-14
date_created: 2022-08-16T09:36:48Z
date_published: 2015-06-01T00:00:00Z
date_updated: 2024-11-06T12:20:01Z
day: '01'
doi: 10.1145/2746539.2746592
extern: '1'
external_id:
arxiv:
- '1504.02268'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1504.02268
month: '06'
oa: 1
oa_version: Preprint
page: 173 - 182
publication: 47th Annual ACM Symposium on Theory of Computing
publication_identifier:
isbn:
- 978-145033536-2
issn:
- 0737-8017
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: Space- and time-efficient algorithm for maintaining dense subgraphs on one-pass
dynamic streams
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...
---
_id: '11901'
abstract:
- lang: eng
text: We consider auctions of indivisible items to unit-demand bidders with budgets.
This setting was suggested as an expressive model for single sponsored search
auctions. Prior work presented mechanisms that compute bidder-optimal outcomes
and are truthful for a restricted set of inputs, i.e., inputs in so-called general
position. This condition is easily violated. We provide the first mechanism that
is truthful in expectation for all inputs and achieves for each bidder no worse
utility than the bidder-optimal outcome. Additionally we give a complete characterization
for which inputs mechanisms that compute bidder-optimal outcomes are truthful.
article_processing_charge: No
article_type: original
author:
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Veronika
full_name: Loitzenbauer, Veronika
last_name: Loitzenbauer
citation:
ama: Henzinger M, Loitzenbauer V. Truthful unit-demand auctions with budgets revisited.
Theoretical Computer Science. 2015;573:1-15. doi:10.1016/j.tcs.2015.01.033
apa: Henzinger, M., & Loitzenbauer, V. (2015). Truthful unit-demand auctions
with budgets revisited. Theoretical Computer Science. Elsevier. https://doi.org/10.1016/j.tcs.2015.01.033
chicago: Henzinger, Monika, and Veronika Loitzenbauer. “Truthful Unit-Demand Auctions
with Budgets Revisited.” Theoretical Computer Science. Elsevier, 2015.
https://doi.org/10.1016/j.tcs.2015.01.033.
ieee: M. Henzinger and V. Loitzenbauer, “Truthful unit-demand auctions with budgets
revisited,” Theoretical Computer Science, vol. 573. Elsevier, pp. 1–15,
2015.
ista: Henzinger M, Loitzenbauer V. 2015. Truthful unit-demand auctions with budgets
revisited. Theoretical Computer Science. 573, 1–15.
mla: Henzinger, Monika, and Veronika Loitzenbauer. “Truthful Unit-Demand Auctions
with Budgets Revisited.” Theoretical Computer Science, vol. 573, Elsevier,
2015, pp. 1–15, doi:10.1016/j.tcs.2015.01.033.
short: M. Henzinger, V. Loitzenbauer, Theoretical Computer Science 573 (2015) 1–15.
date_created: 2022-08-17T09:06:53Z
date_published: 2015-03-30T00:00:00Z
date_updated: 2024-11-06T12:24:01Z
day: '30'
doi: 10.1016/j.tcs.2015.01.033
extern: '1'
intvolume: ' 573'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1016/j.tcs.2015.01.033
month: '03'
oa: 1
oa_version: None
page: 1-15
publication: Theoretical Computer Science
publication_identifier:
issn:
- 0304-3975
publication_status: published
publisher: Elsevier
quality_controlled: '1'
scopus_import: '1'
status: public
title: Truthful unit-demand auctions with budgets revisited
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 573
year: '2015'
...