---
OA_place: repository
OA_type: green
_id: '21720'
abstract:
- lang: eng
  text: "We present an exact fully-dynamic minimum cut algorithm that runs in \U0001D45B\U0001D45C⁡(1)
    deterministic update time when the minimum cut size is at most 2Θ⁡(log3/4−\U0001D450⁡\U0001D45B)
    for any \U0001D450 >0, improving on the previous algorithm of Jin, Sun, and Thorup
    (SODA 2024) whose minimum cut size limit is (log⁡\U0001D45B)\U0001D45C⁡(1). Combined
    with graph sparsification, we obtain the first (1 +\U0001D716)-approximate fully-dynamic
    minimum cut algorithm on weighted graphs, for any \U0001D716 ≥2−Θ⁡(log3/4−\U0001D450⁡\U0001D45B),
    in \U0001D45B\U0001D45C⁡(1) randomized update time.\r\nOur main technical contribution
    is a deterministic local minimum cut algorithm, which replaces the randomized
    LocalKCut procedure from El-Hayek, Henzinger, and Li (SODA 2025)."
acknowledgement: Funded by the European union. Views and opinions expressed are however
  those of the author(s) only and do not necessarily reflect those of the European
  Union or the European Research Council Executive Agency. Neither the European Union
  nor the granting authority can be held responsible for them. This project has received
  funding from the European Research Council (ERC) under the European Union’s Horizon
  2020 research and innovation programme (MoDynStruct, No. 101019564) and the Austrian
  Science Fund (FWF) grant DOI 10.55776/I5982. For open access purposes, the author
  has applied a CC BY public copyright license to any author-accepted manuscript version
  arising from this submission.
article_processing_charge: No
arxiv: 1
author:
- first_name: Antoine
  full_name: El-Hayek, Antoine
  id: 888a098e-fcac-11ee-aff7-d347be57b725
  last_name: El-Hayek
  orcid: 0000-0003-4268-7368
- 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: Jason
  full_name: Li, Jason
  last_name: Li
citation:
  ama: 'El-Hayek A, Henzinger M, Li J. Deterministic and exact fully-dynamic minimum
    cut of superpolylogarithmic size in subpolynomial time. In: <i>Proceedings of
    the Annual ACM SIAM Symposium on Discrete Algorithms</i>. Vol 2026. Society for
    Industrial and Applied Mathematics; 2026:613-663. doi:<a href="https://doi.org/10.1137/1.9781611978971.25">10.1137/1.9781611978971.25</a>'
  apa: 'El-Hayek, A., Henzinger, M., &#38; Li, J. (2026). Deterministic and exact
    fully-dynamic minimum cut of superpolylogarithmic size in subpolynomial time.
    In <i>Proceedings of the Annual ACM SIAM Symposium on Discrete Algorithms</i>
    (Vol. 2026, pp. 613–663). Vancouver, Canada: Society for Industrial and Applied
    Mathematics. <a href="https://doi.org/10.1137/1.9781611978971.25">https://doi.org/10.1137/1.9781611978971.25</a>'
  chicago: El-Hayek, Antoine, Monika Henzinger, and Jason Li. “Deterministic and Exact
    Fully-Dynamic Minimum Cut of Superpolylogarithmic Size in Subpolynomial Time.”
    In <i>Proceedings of the Annual ACM SIAM Symposium on Discrete Algorithms</i>,
    2026:613–63. Society for Industrial and Applied Mathematics, 2026. <a href="https://doi.org/10.1137/1.9781611978971.25">https://doi.org/10.1137/1.9781611978971.25</a>.
  ieee: A. El-Hayek, M. Henzinger, and J. Li, “Deterministic and exact fully-dynamic
    minimum cut of superpolylogarithmic size in subpolynomial time,” in <i>Proceedings
    of the Annual ACM SIAM Symposium on Discrete Algorithms</i>, Vancouver, Canada,
    2026, vol. 2026, pp. 613–663.
  ista: 'El-Hayek A, Henzinger M, Li J. 2026. Deterministic and exact fully-dynamic
    minimum cut of superpolylogarithmic size in subpolynomial time. Proceedings of
    the Annual ACM SIAM Symposium on Discrete Algorithms. SODA: Symposium on Discrete
    Algorithms vol. 2026, 613–663.'
  mla: El-Hayek, Antoine, et al. “Deterministic and Exact Fully-Dynamic Minimum Cut
    of Superpolylogarithmic Size in Subpolynomial Time.” <i>Proceedings of the Annual
    ACM SIAM Symposium on Discrete Algorithms</i>, vol. 2026, Society for Industrial
    and Applied Mathematics, 2026, pp. 613–63, doi:<a href="https://doi.org/10.1137/1.9781611978971.25">10.1137/1.9781611978971.25</a>.
  short: A. El-Hayek, M. Henzinger, J. Li, in:, Proceedings of the Annual ACM SIAM
    Symposium on Discrete Algorithms, Society for Industrial and Applied Mathematics,
    2026, pp. 613–663.
conference:
  end_date: 2026-01-14
  location: Vancouver, Canada
  name: 'SODA: Symposium on Discrete Algorithms'
  start_date: 2026-01-11
date_created: 2026-04-12T22:01:51Z
date_published: 2026-01-07T00:00:00Z
date_updated: 2026-05-04T11:36:47Z
day: '07'
department:
- _id: MoHe
- _id: GradSch
doi: 10.1137/1.9781611978971.25
ec_funded: 1
external_id:
  arxiv:
  - '2512.13105'
intvolume: '      2026'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.2512.13105
month: '01'
oa: 1
oa_version: Preprint
page: 613-663
project:
- _id: bd9ca328-d553-11ed-ba76-dc4f890cfe62
  call_identifier: H2020
  grant_number: '101019564'
  name: The design and evaluation of modern fully dynamic data structures
- _id: bda196b2-d553-11ed-ba76-8e8ee6c21103
  grant_number: I05982
  name: Static and Dynamic Hierarchical Graph Decompositions
publication: Proceedings of the Annual ACM SIAM Symposium on Discrete Algorithms
publication_identifier:
  eisbn:
  - '9781611978971'
  eissn:
  - 1557-9468
  issn:
  - 1071-9040
publication_status: published
publisher: Society for Industrial and Applied Mathematics
quality_controlled: '1'
scopus_import: '1'
status: public
title: Deterministic and exact fully-dynamic minimum cut of superpolylogarithmic size
  in subpolynomial time
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 2026
year: '2026'
...
---
OA_place: publisher
OA_type: gold
_id: '19858'
abstract:
- lang: eng
  text: "Given a graph G that undergoes a sequence of edge insertions and deletions,
    we study the Maximum k-Edge Coloring problem (MkEC): Having access to k different
    colors, color as many edges of G as possible such that no two adjacent edges share
    the same color. While this problem is different from simply maintaining a b-matching
    with b = k, the two problems are related. However, maximum b-matching can be solved
    efficiently in the static setting, whereas MkEC is NP-hard and even APX-hard for
    k ≥ 2. \r\nWe present new results on both problems: For b-matching, we show a
    new integrality gap result and we adapt Wajc’s matching sparsification scheme
    [David Wajc, 2020] for the case where b is a constant.\r\nUsing these as basis,
    we give three new algorithms for the dynamic MkEC problem: Our MatchO algorithm
    builds on the dynamic (2+ε)-approximation algorithm of Bhattacharya, Gupta, and
    Mohan [Sayan Bhattacharya et al., 2017] for b-matching and achieves a (2+ε)(k+1)/k-approximation
    in O(poly(log n, ε^-1)) update time against an oblivious adversary. Our MatchA
    algorithm builds on the dynamic (7+ε)-approximation algorithm by Bhattacharya,
    Henzinger, and Italiano [Sayan Bhattacharya et al., 2015] for fractional b-matching
    and achieves a (7+ε)(3k+3)/(3k-1)-approximation in O(poly(log n, ε^-1)) update
    time against an adaptive adversary. Moreover, our reductions use the dynamic b-matching
    algorithm as a black box, so any future improvement in the approximation ratio
    for dynamic b-matching will automatically translate into a better approximation
    ratio for our algorithms. Finally, we present a greedy algorithm with O(Δ+k) update
    time, which guarantees a 2.16 approximation factor."
acknowledgement: "This project has received funding from the European Research Council
  (ERC) under the\r\nEuropean Union’s Horizon 2020 research and innovation programme
  (MoDynStruct, No. 101019564) and the Austrian Science Fund (FWF) grant DOI 10.55776/Z422,
  grant DOI 10.55776/I5982, and grant DOI 10.55776/P33775 with additional funding
  from the netidee SCIENCE Stiftung, 2020–2024. This work was further supported by
  the Federal Ministry of Education and Research (BMBF) project, 6G-RIC: 6G Research
  and Innovation Cluster, grant 16KISK020K."
alternative_title:
- LIPIcs
article_number: '4'
article_processing_charge: No
arxiv: 1
author:
- first_name: Antoine
  full_name: El-Hayek, Antoine
  id: 888a098e-fcac-11ee-aff7-d347be57b725
  last_name: El-Hayek
  orcid: 0000-0003-4268-7368
- first_name: Kathrin
  full_name: Hanauer, Kathrin
  last_name: Hanauer
- 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: 'El-Hayek A, Hanauer K, Henzinger M. On b-matching and fully-dynamic maximum
    k-edge coloring. In: <i>4th Symposium on Algorithmic Foundations of Dynamic Networks</i>.
    Vol 330. Schloss Dagstuhl - Leibniz-Zentrum für Informatik; 2025. doi:<a href="https://doi.org/10.4230/LIPIcs.SAND.2025.4">10.4230/LIPIcs.SAND.2025.4</a>'
  apa: 'El-Hayek, A., Hanauer, K., &#38; Henzinger, M. (2025). On b-matching and fully-dynamic
    maximum k-edge coloring. In <i>4th Symposium on Algorithmic Foundations of Dynamic
    Networks</i> (Vol. 330). Liverpool, United Kingdom: Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik. <a href="https://doi.org/10.4230/LIPIcs.SAND.2025.4">https://doi.org/10.4230/LIPIcs.SAND.2025.4</a>'
  chicago: El-Hayek, Antoine, Kathrin Hanauer, and Monika Henzinger. “On B-Matching
    and Fully-Dynamic Maximum k-Edge Coloring.” In <i>4th Symposium on Algorithmic
    Foundations of Dynamic Networks</i>, Vol. 330. Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2025. <a href="https://doi.org/10.4230/LIPIcs.SAND.2025.4">https://doi.org/10.4230/LIPIcs.SAND.2025.4</a>.
  ieee: A. El-Hayek, K. Hanauer, and M. Henzinger, “On b-matching and fully-dynamic
    maximum k-edge coloring,” in <i>4th Symposium on Algorithmic Foundations of Dynamic
    Networks</i>, Liverpool, United Kingdom, 2025, vol. 330.
  ista: 'El-Hayek A, Hanauer K, Henzinger M. 2025. On b-matching and fully-dynamic
    maximum k-edge coloring. 4th Symposium on Algorithmic Foundations of Dynamic Networks.
    SAND: Symposium on Algorithmic Foundations of Dynamic Networks, LIPIcs, vol. 330,
    4.'
  mla: El-Hayek, Antoine, et al. “On B-Matching and Fully-Dynamic Maximum k-Edge Coloring.”
    <i>4th Symposium on Algorithmic Foundations of Dynamic Networks</i>, vol. 330,
    4, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2025, doi:<a href="https://doi.org/10.4230/LIPIcs.SAND.2025.4">10.4230/LIPIcs.SAND.2025.4</a>.
  short: A. El-Hayek, K. Hanauer, M. Henzinger, in:, 4th Symposium on Algorithmic
    Foundations of Dynamic Networks, Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2025.
conference:
  end_date: 2025-06-11
  location: Liverpool, United Kingdom
  name: 'SAND: Symposium on Algorithmic Foundations of Dynamic Networks'
  start_date: 2025-06-09
corr_author: '1'
date_created: 2025-06-22T22:02:06Z
date_published: 2025-06-02T00:00:00Z
date_updated: 2025-09-30T13:37:28Z
day: '02'
ddc:
- '000'
department:
- _id: MoHe
doi: 10.4230/LIPIcs.SAND.2025.4
ec_funded: 1
external_id:
  arxiv:
  - '2310.01149'
  isi:
  - '001532136900004'
file:
- access_level: open_access
  checksum: ad93a1e052adb29d7bfe8bd551bab193
  content_type: application/pdf
  creator: dernst
  date_created: 2025-06-23T11:23:29Z
  date_updated: 2025-06-23T11:23:29Z
  file_id: '19872'
  file_name: 2025_LIPIcs_ElHayek.pdf
  file_size: 995666
  relation: main_file
  success: 1
file_date_updated: 2025-06-23T11:23:29Z
has_accepted_license: '1'
intvolume: '       330'
isi: 1
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '06'
oa: 1
oa_version: Published Version
project:
- _id: bd9ca328-d553-11ed-ba76-dc4f890cfe62
  call_identifier: H2020
  grant_number: '101019564'
  name: The design and evaluation of modern fully dynamic data structures
- _id: 34def286-11ca-11ed-8bc3-da5948e1613c
  grant_number: Z00422
  name: Efficient algorithms
- _id: bda196b2-d553-11ed-ba76-8e8ee6c21103
  grant_number: I05982
  name: Static and Dynamic Hierarchical Graph Decompositions
- _id: bd9e3a2e-d553-11ed-ba76-8aa684ce17fe
  grant_number: P33775
  name: Fast Algorithms for a Reactive Network Layer
publication: 4th Symposium on Algorithmic Foundations of Dynamic Networks
publication_identifier:
  isbn:
  - '9783959773683'
  issn:
  - 1868-8969
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
scopus_import: '1'
status: public
title: On b-matching and fully-dynamic maximum k-edge coloring
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: conference
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 330
year: '2025'
...
---
OA_place: repository
OA_type: green
_id: '19982'
abstract:
- lang: eng
  text: "Dynamically maintaining the minimum cut in a graph G under edge insertions
    and deletion is a fundamental problem in dynamic graph algorithms for which no
    conditional lower bound on the time per operation exists. In an n-node graph the
    best known (1 + o (1))-approximate algorithm takes  update time [14]. If the minimum
    cut is guaranteed to be (log n )o (1), a deterministic exact algorithm with n
    o (1) update time exists [8].\r\nWe present the first fully dynamic algorithm
    for (1 + o (1))-approximate minimum cut with n o(1) update time. Our main technical
    contribution is to show that it suffices to consider small-volume cuts in suitably
    contracted graphs."
acknowledgement: This project has received funding from the European Research Council
  (ERC) under the European Union’sHorizon 2020 research and innovation programme (MoDynStruct,
  No. 101019564) and the Austrian Science Fund(FWF) grant DOI 10.55776/Z422, grant
  DOI 10.55776/I5982, and grant DOI 10.55776/P33775 with additional funding from the
  netidee SCIENCE Stiftung, 2020–2024.
article_processing_charge: No
arxiv: 1
author:
- first_name: Antoine
  full_name: El-Hayek, Antoine
  id: 888a098e-fcac-11ee-aff7-d347be57b725
  last_name: El-Hayek
  orcid: 0000-0003-4268-7368
- 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: Jason
  full_name: Li, Jason
  last_name: Li
citation:
  ama: 'El-Hayek A, Henzinger M, Li J. Fully dynamic approximate minimum cut in subpolynomial
    time per operation. In: <i>Proceedings of the 2025 Annual ACM-SIAM Symposium on
    Discrete Algorithms</i>. Society for Industrial and Applied Mathematics; 2025:750-784.
    doi:<a href="https://doi.org/10.1137/1.9781611978322.22">10.1137/1.9781611978322.22</a>'
  apa: 'El-Hayek, A., Henzinger, M., &#38; Li, J. (2025). Fully dynamic approximate
    minimum cut in subpolynomial time per operation. In <i>Proceedings of the 2025
    Annual ACM-SIAM Symposium on Discrete Algorithms</i> (pp. 750–784). New Orleans,
    LA, United States: Society for Industrial and Applied Mathematics. <a href="https://doi.org/10.1137/1.9781611978322.22">https://doi.org/10.1137/1.9781611978322.22</a>'
  chicago: El-Hayek, Antoine, Monika Henzinger, and Jason Li. “Fully Dynamic Approximate
    Minimum Cut in Subpolynomial Time per Operation.” In <i>Proceedings of the 2025
    Annual ACM-SIAM Symposium on Discrete Algorithms</i>, 750–84. Society for Industrial
    and Applied Mathematics, 2025. <a href="https://doi.org/10.1137/1.9781611978322.22">https://doi.org/10.1137/1.9781611978322.22</a>.
  ieee: A. El-Hayek, M. Henzinger, and J. Li, “Fully dynamic approximate minimum cut
    in subpolynomial time per operation,” in <i>Proceedings of the 2025 Annual ACM-SIAM
    Symposium on Discrete Algorithms</i>, New Orleans, LA, United States, 2025, pp.
    750–784.
  ista: 'El-Hayek A, Henzinger M, Li J. 2025. Fully dynamic approximate minimum cut
    in subpolynomial time per operation. Proceedings of the 2025 Annual ACM-SIAM Symposium
    on Discrete Algorithms. SODA: Symposium on Discrete Algorithms, 750–784.'
  mla: El-Hayek, Antoine, et al. “Fully Dynamic Approximate Minimum Cut in Subpolynomial
    Time per Operation.” <i>Proceedings of the 2025 Annual ACM-SIAM Symposium on Discrete
    Algorithms</i>, Society for Industrial and Applied Mathematics, 2025, pp. 750–84,
    doi:<a href="https://doi.org/10.1137/1.9781611978322.22">10.1137/1.9781611978322.22</a>.
  short: A. El-Hayek, M. Henzinger, J. Li, in:, Proceedings of the 2025 Annual ACM-SIAM
    Symposium on Discrete Algorithms, Society for Industrial and Applied Mathematics,
    2025, pp. 750–784.
conference:
  end_date: 2025-01-15
  location: New Orleans, LA, United States
  name: 'SODA: Symposium on Discrete Algorithms'
  start_date: 2025-01-12
corr_author: '1'
date_created: 2025-07-10T13:08:57Z
date_published: 2025-01-07T00:00:00Z
date_updated: 2025-12-29T12:30:04Z
day: '07'
department:
- _id: MoHe
doi: 10.1137/1.9781611978322.22
ec_funded: 1
external_id:
  arxiv:
  - '2412.15069'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.2412.15069
month: '01'
oa: 1
oa_version: Preprint
page: 750-784
project:
- _id: bd9ca328-d553-11ed-ba76-dc4f890cfe62
  call_identifier: H2020
  grant_number: '101019564'
  name: The design and evaluation of modern fully dynamic data structures
- _id: 34def286-11ca-11ed-8bc3-da5948e1613c
  grant_number: Z00422
  name: Efficient algorithms
- _id: bda196b2-d553-11ed-ba76-8e8ee6c21103
  grant_number: I05982
  name: Static and Dynamic Hierarchical Graph Decompositions
- _id: bd9e3a2e-d553-11ed-ba76-8aa684ce17fe
  grant_number: P33775
  name: Fast Algorithms for a Reactive Network Layer
publication: Proceedings of the 2025 Annual ACM-SIAM Symposium on Discrete Algorithms
publication_identifier:
  eisbn:
  - '9781611978322'
publication_status: published
publisher: Society for Industrial and Applied Mathematics
quality_controlled: '1'
status: public
title: Fully dynamic approximate minimum cut in subpolynomial time per operation
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2025'
...
---
OA_place: publisher
OA_type: hybrid
_id: '20051'
abstract:
- lang: eng
  text: "We revisit the majority problem in the population protocol communication
    model, as first studied by Angluin et al. (Distributed Computing 2008). We consider
    a more general version of this problem known as plurality consensus, which has
    already been studied intensively in the literature. In this problem, each node
    in a system of n nodes, has initially one of k different opinions, and they need
    to agree on the (relative) majority opinion. In particular, we consider the important
    and intensively studied model of Undecided State Dynamics.\r\nOur main contribution
    is an almost tight lower bound on the stabilization time: we prove that there
    exists an initial configuration, even with bias \\Delta = \\omega(\\sqrt{n\\log
    n}), where stabilization requires \\Omega(kn\\log \\frac {\\sqrt n} {k \\log n})
    interactions, or equivalently, \\Omega(k\\log \\frac {\\sqrt n} {k \\log n}) parallel
    time for any k = o\\left(\\frac {\\sqrt n}{\\log n}\\right). This bound is tight
    for any k \\le n^{\\frac 1 2 - \\epsilon}, where \\epsilon >0 can be any small
    constant, as Amir et al.~(PODC'23) gave a O(k\\log n) parallel time upper bound
    for k = O\\left(\\frac {\\sqrt n} {\\log ^2 n}\\right)."
acknowledgement: "This project has received funding from the European Research Council
  (ERC) under the European Union’s Horizon 2020 research and innovation programme
  (MoDynStruct, No. 101019564) and the Austrian Science Fund (FWF) grant DOI 10.55776/I5862,grant
  DOI 10.55776/I5982, and grant DOI 10.55776/P33775 with\r\nadditional funding from
  the netidee SCIENCE Stiftung, 2020–2024\r\nand the German Research Foundation (DFG),
  grant 470029389\r\n(FlexNets)."
article_processing_charge: Yes (via OA deal)
arxiv: 1
author:
- first_name: Antoine
  full_name: El-Hayek, Antoine
  id: 888a098e-fcac-11ee-aff7-d347be57b725
  last_name: El-Hayek
  orcid: 0000-0003-4268-7368
- first_name: Robert
  full_name: Elsässer, Robert
  last_name: Elsässer
- first_name: Stefan
  full_name: Schmid, Stefan
  last_name: Schmid
citation:
  ama: 'El-Hayek A, Elsässer R, Schmid S. An almost tight lower bound for plurality
    consensus with undecided state dynamics in the population protocol model. In:
    <i>Proceedings of the ACM Symposium on Principles of Distributed Computing</i>.
    Association for Computing Machinery; 2025. doi:<a href="https://doi.org/10.1145/3732772.3733505">10.1145/3732772.3733505</a>'
  apa: 'El-Hayek, A., Elsässer, R., &#38; Schmid, S. (2025). An almost tight lower
    bound for plurality consensus with undecided state dynamics in the population
    protocol model. In <i>Proceedings of the ACM Symposium on Principles of Distributed
    Computing</i>. Huatulco, Mexico: Association for Computing Machinery. <a href="https://doi.org/10.1145/3732772.3733505">https://doi.org/10.1145/3732772.3733505</a>'
  chicago: El-Hayek, Antoine, Robert Elsässer, and Stefan Schmid. “An Almost Tight
    Lower Bound for Plurality Consensus with Undecided State Dynamics in the Population
    Protocol Model.” In <i>Proceedings of the ACM Symposium on Principles of Distributed
    Computing</i>. Association for Computing Machinery, 2025. <a href="https://doi.org/10.1145/3732772.3733505">https://doi.org/10.1145/3732772.3733505</a>.
  ieee: A. El-Hayek, R. Elsässer, and S. Schmid, “An almost tight lower bound for
    plurality consensus with undecided state dynamics in the population protocol model,”
    in <i>Proceedings of the ACM Symposium on Principles of Distributed Computing</i>,
    Huatulco, Mexico, 2025.
  ista: 'El-Hayek A, Elsässer R, Schmid S. 2025. An almost tight lower bound for plurality
    consensus with undecided state dynamics in the population protocol model. Proceedings
    of the ACM Symposium on Principles of Distributed Computing. PODC: Symposium on
    Principles of Distributed Computing.'
  mla: El-Hayek, Antoine, et al. “An Almost Tight Lower Bound for Plurality Consensus
    with Undecided State Dynamics in the Population Protocol Model.” <i>Proceedings
    of the ACM Symposium on Principles of Distributed Computing</i>, Association for
    Computing Machinery, 2025, doi:<a href="https://doi.org/10.1145/3732772.3733505">10.1145/3732772.3733505</a>.
  short: A. El-Hayek, R. Elsässer, S. Schmid, in:, Proceedings of the ACM Symposium
    on Principles of Distributed Computing, Association for Computing Machinery, 2025.
conference:
  end_date: 2025-06-20
  location: Huatulco, Mexico
  name: 'PODC: Symposium on Principles of Distributed Computing'
  start_date: 2025-06-16
corr_author: '1'
date_created: 2025-07-21T08:16:15Z
date_published: 2025-06-13T00:00:00Z
date_updated: 2025-10-16T13:08:45Z
day: '13'
ddc:
- '000'
department:
- _id: MoHe
doi: 10.1145/3732772.3733505
ec_funded: 1
external_id:
  arxiv:
  - '2505.02765'
  isi:
  - '001525534800066'
file:
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  checksum: 52976d226f3f691aa519d71c1c718fa5
  content_type: application/pdf
  creator: dernst
  date_created: 2025-08-04T09:10:55Z
  date_updated: 2025-08-04T09:10:55Z
  file_id: '20115'
  file_name: 2025_PODC_ElHayek.pdf
  file_size: 2200347
  relation: main_file
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file_date_updated: 2025-08-04T09:10:55Z
has_accepted_license: '1'
isi: 1
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
project:
- _id: bd9ca328-d553-11ed-ba76-dc4f890cfe62
  call_identifier: H2020
  grant_number: '101019564'
  name: The design and evaluation of modern fully dynamic data structures
- _id: bda196b2-d553-11ed-ba76-8e8ee6c21103
  grant_number: I05982
  name: Static and Dynamic Hierarchical Graph Decompositions
- _id: bd9e3a2e-d553-11ed-ba76-8aa684ce17fe
  grant_number: P33775
  name: Fast Algorithms for a Reactive Network Layer
publication: Proceedings of the ACM Symposium on Principles of Distributed Computing
publication_identifier:
  isbn:
  - ' 9798400718854'
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
status: public
title: An almost tight lower bound for plurality consensus with undecided state dynamics
  in the population protocol model
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: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2025'
...
---
OA_place: publisher
OA_type: hybrid
_id: '20052'
abstract:
- lang: eng
  text: "This paper revisits a fundamental distributed computing problem in the population
    protocol model. Provided n agents each starting with an input color in [k], the
    relative majority problem asks to find the predominant color. In the population
    protocol model, at each time step, a scheduler selects two agents that first learn
    each other's states and then update their states based on what they learned.\r\nWe
    present the Circles protocol that solves the relative majority problem with k3
    states. It is always-correct under weakly fair scheduling. Not only does it improve
    upon the best known upper bound of O(k7), but it also shows a strikingly simpler
    design inspired by energy minimization in chemical settings."
acknowledgement: 'This project has received funding from the European Research Council
  (ERC) under the European Union’s Horizon 2020 research and innovation programme
  (MoDynStruct, No. 101019564) and the Austrian Science Fund (FWF) grant DOI 10.55776/I5982,
  and grant DOI 10.55776/P33775 with additional funding from the netidee SCIENCE Stiftung,
  2020–2024 and the German Research Foundation (DFG), grant 470029389 (FlexNets). '
article_processing_charge: No
author:
- first_name: Tom-Lukas
  full_name: Breitkopf, Tom-Lukas
  last_name: Breitkopf
- first_name: Julien
  full_name: Dallot, Julien
  last_name: Dallot
- first_name: Antoine
  full_name: El-Hayek, Antoine
  id: 888a098e-fcac-11ee-aff7-d347be57b725
  last_name: El-Hayek
  orcid: 0000-0003-4268-7368
- first_name: Stefan
  full_name: Schmid, Stefan
  last_name: Schmid
citation:
  ama: 'Breitkopf T-L, Dallot J, El-Hayek A, Schmid S. Brief announcement: Minimizing
    energy solves relative majority with a cubic number of states in population protocols.
    In: <i>Proceedings of the ACM Symposium on Principles of Distributed Computing</i>.
    Association for Computing Machinery; 2025:549-552. doi:<a href="https://doi.org/10.1145/3732772.3733512">10.1145/3732772.3733512</a>'
  apa: 'Breitkopf, T.-L., Dallot, J., El-Hayek, A., &#38; Schmid, S. (2025). Brief
    announcement: Minimizing energy solves relative majority with a cubic number of
    states in population protocols. In <i>Proceedings of the ACM Symposium on Principles
    of Distributed Computing</i> (pp. 549–552). Huatulco, Mexico: Association for
    Computing Machinery. <a href="https://doi.org/10.1145/3732772.3733512">https://doi.org/10.1145/3732772.3733512</a>'
  chicago: 'Breitkopf, Tom-Lukas, Julien Dallot, Antoine El-Hayek, and Stefan Schmid.
    “Brief Announcement: Minimizing Energy Solves Relative Majority with a Cubic Number
    of States in Population Protocols.” In <i>Proceedings of the ACM Symposium on
    Principles of Distributed Computing</i>, 549–52. Association for Computing Machinery,
    2025. <a href="https://doi.org/10.1145/3732772.3733512">https://doi.org/10.1145/3732772.3733512</a>.'
  ieee: 'T.-L. Breitkopf, J. Dallot, A. El-Hayek, and S. Schmid, “Brief announcement:
    Minimizing energy solves relative majority with a cubic number of states in population
    protocols,” in <i>Proceedings of the ACM Symposium on Principles of Distributed
    Computing</i>, Huatulco, Mexico, 2025, pp. 549–552.'
  ista: 'Breitkopf T-L, Dallot J, El-Hayek A, Schmid S. 2025. Brief announcement:
    Minimizing energy solves relative majority with a cubic number of states in population
    protocols. Proceedings of the ACM Symposium on Principles of Distributed Computing.
    PODC: Symposium on Principles of Distributed Computing, 549–552.'
  mla: 'Breitkopf, Tom-Lukas, et al. “Brief Announcement: Minimizing Energy Solves
    Relative Majority with a Cubic Number of States in Population Protocols.” <i>Proceedings
    of the ACM Symposium on Principles of Distributed Computing</i>, Association for
    Computing Machinery, 2025, pp. 549–52, doi:<a href="https://doi.org/10.1145/3732772.3733512">10.1145/3732772.3733512</a>.'
  short: T.-L. Breitkopf, J. Dallot, A. El-Hayek, S. Schmid, in:, Proceedings of the
    ACM Symposium on Principles of Distributed Computing, Association for Computing
    Machinery, 2025, pp. 549–552.
conference:
  end_date: 2025-06-20
  location: Huatulco, Mexico
  name: 'PODC: Symposium on Principles of Distributed Computing'
  start_date: 2025-06-16
corr_author: '1'
date_created: 2025-07-21T08:17:04Z
date_published: 2025-06-13T00:00:00Z
date_updated: 2026-02-16T11:46:37Z
day: '13'
ddc:
- '000'
department:
- _id: MoHe
doi: 10.1145/3732772.3733512
ec_funded: 1
external_id:
  isi:
  - '001525534800069'
file:
- access_level: open_access
  checksum: e99679ffb28877b7cea4d54860302790
  content_type: application/pdf
  creator: dernst
  date_created: 2025-08-05T07:32:01Z
  date_updated: 2025-08-05T07:32:01Z
  file_id: '20123'
  file_name: 2025_PODC_Breitkopf.pdf
  file_size: 549706
  relation: main_file
  success: 1
file_date_updated: 2025-08-05T07:32:01Z
has_accepted_license: '1'
isi: 1
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: 549-552
project:
- _id: bd9ca328-d553-11ed-ba76-dc4f890cfe62
  call_identifier: H2020
  grant_number: '101019564'
  name: The design and evaluation of modern fully dynamic data structures
- _id: bda196b2-d553-11ed-ba76-8e8ee6c21103
  grant_number: I05982
  name: Static and Dynamic Hierarchical Graph Decompositions
- _id: bd9e3a2e-d553-11ed-ba76-8aa684ce17fe
  grant_number: P33775
  name: Fast Algorithms for a Reactive Network Layer
publication: Proceedings of the ACM Symposium on Principles of Distributed Computing
publication_identifier:
  isbn:
  - '9798400718854'
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
status: public
title: 'Brief announcement: Minimizing energy solves relative majority with a cubic
  number of states in population protocols'
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: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2025'
...
---
OA_place: publisher
OA_type: gold
_id: '18557'
abstract:
- lang: eng
  text: Broadcast and Consensus are most fundamental tasks in distributed computing.
    These tasks are particularly challenging in dynamic networks where communication
    across the network links may be unreliable, e.g., due to mobility or failures.
    Over the last years, researchers have derived several impossibility results and
    high time complexity lower bounds for these tasks. Specifically for the setting
    where in each round of communication the adversary is allowed to choose one rooted
    tree along which the information is disseminated, there is a lower as well as
    an upper bound that is linear in the number n of nodes for Broadcast and for n
    ≥ 3 the adversary can guarantee that Consensus never happens. This setting is
    called the oblivious message adversary for rooted trees. Also note that if the
    adversary is allowed to choose a graph that does not contain a rooted tree, then
    it can guarantee that Broadcast and Consensus will never happen. However, such
    deterministic adversarial models may be overly pessimistic, as many processes
    in real-world settings are stochastic in nature rather than worst-case. This paper
    studies Broadcast on stochastic dynamic networks and shows that the situation
    is very different to the deterministic case. In particular, we show that if information
    dissemination occurs along random rooted trees and directed Erdős–Rényi graphs,
    Broadcast completes in O(log n) rounds of communication with high probability.
    The fundamental insight in our analysis is that key variables are mutually independent.
    We then study two adversarial models, (a) one with Byzantine nodes and (b) one
    where an adversary controls the edges. (a) Our techniques without Byzantine nodes
    are general enough so that they can be extended to Byzantine nodes. (b) In the
    spirit of smoothed analysis, we introduce the notion of randomized oblivious message
    adversary, where in each round, an adversary picks k ≤ 2n/3 edges to appear in
    the communication network, and then a graph (e.g. rooted tree or directed Erdős–Rényi
    graph) is chosen uniformly at random among the set of all such graphs that include
    these edges. We show that Broadcast completes in a finite number of rounds, which
    is, e.g., O(k+log n) rounds in rooted trees. We then extend these results to All-to-All
    Broadcast, and Consensus, and give lower bounds that show that most of our upper
    bounds are tight.
acknowledgement: "Antoine El-Hayek: This project has received funding from the Austrian
  Science Fund\r\n(FWF) grant DOI 10.55776/P33775 with additional funding from the
  netidee SCIENCE Stiftung,\r\n2020–2024.\r\nMonika Henzinger: This project has received
  funding from the European Research Council (ERC)\r\nunder the European Union’s Horizon
  2020 research and innovation programme (MoDynStruct,\r\nNo. 101019564) and the Austrian
  Science Fund (FWF) grant DOI 10.55776/Z422, grant DOI\r\n10.55776/I5982, and grant
  DOI 10.55776/P33775 with additional funding from the netidee SCIENCE\r\nStiftung,
  2020–2024.\r\nStefan Schmid: This project has received funding from the German Research
  Foundation (DFG),\r\nSPP 2378 (project ReNO), 2023-2027."
alternative_title:
- LIPIcs
article_number: '21'
article_processing_charge: Yes
arxiv: 1
author:
- first_name: Antoine
  full_name: El-Hayek, Antoine
  id: 888a098e-fcac-11ee-aff7-d347be57b725
  last_name: El-Hayek
  orcid: 0000-0003-4268-7368
- 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: Stefan
  full_name: Schmid, Stefan
  last_name: Schmid
citation:
  ama: 'El-Hayek A, Henzinger M, Schmid S. Broadcast and Consensus in stochastic dynamic
    networks with Byzantine nodes and adversarial edges. In: <i>38th International
    Symposium on Distributed Computing</i>. Vol 319. Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik; 2024. doi:<a href="https://doi.org/10.4230/LIPIcs.DISC.2024.21">10.4230/LIPIcs.DISC.2024.21</a>'
  apa: 'El-Hayek, A., Henzinger, M., &#38; Schmid, S. (2024). Broadcast and Consensus
    in stochastic dynamic networks with Byzantine nodes and adversarial edges. In
    <i>38th International Symposium on Distributed Computing</i> (Vol. 319). Madrid,
    Spain: Schloss Dagstuhl - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPIcs.DISC.2024.21">https://doi.org/10.4230/LIPIcs.DISC.2024.21</a>'
  chicago: El-Hayek, Antoine, Monika Henzinger, and Stefan Schmid. “Broadcast and
    Consensus in Stochastic Dynamic Networks with Byzantine Nodes and Adversarial
    Edges.” In <i>38th International Symposium on Distributed Computing</i>, Vol.
    319. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2024. <a href="https://doi.org/10.4230/LIPIcs.DISC.2024.21">https://doi.org/10.4230/LIPIcs.DISC.2024.21</a>.
  ieee: A. El-Hayek, M. Henzinger, and S. Schmid, “Broadcast and Consensus in stochastic
    dynamic networks with Byzantine nodes and adversarial edges,” in <i>38th International
    Symposium on Distributed Computing</i>, Madrid, Spain, 2024, vol. 319.
  ista: 'El-Hayek A, Henzinger M, Schmid S. 2024. Broadcast and Consensus in stochastic
    dynamic networks with Byzantine nodes and adversarial edges. 38th International
    Symposium on Distributed Computing. DISC: Symposium on Distributed Computing,
    LIPIcs, vol. 319, 21.'
  mla: El-Hayek, Antoine, et al. “Broadcast and Consensus in Stochastic Dynamic Networks
    with Byzantine Nodes and Adversarial Edges.” <i>38th International Symposium on
    Distributed Computing</i>, vol. 319, 21, Schloss Dagstuhl - Leibniz-Zentrum für
    Informatik, 2024, doi:<a href="https://doi.org/10.4230/LIPIcs.DISC.2024.21">10.4230/LIPIcs.DISC.2024.21</a>.
  short: A. El-Hayek, M. Henzinger, S. Schmid, in:, 38th International Symposium on
    Distributed Computing, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2024.
conference:
  end_date: 2024-11-01
  location: Madrid, Spain
  name: 'DISC: Symposium on Distributed Computing'
  start_date: 2024-10-28
corr_author: '1'
date_created: 2024-11-17T23:01:47Z
date_published: 2024-10-24T00:00:00Z
date_updated: 2025-12-02T13:51:28Z
day: '24'
ddc:
- '000'
department:
- _id: MoHe
doi: 10.4230/LIPIcs.DISC.2024.21
ec_funded: 1
external_id:
  arxiv:
  - '2302.11988'
  isi:
  - '001542467600021'
file:
- access_level: open_access
  checksum: d6c8277331cafa188c33ba1717206cf4
  content_type: application/pdf
  creator: dernst
  date_created: 2024-11-18T08:02:45Z
  date_updated: 2024-11-18T08:02:45Z
  file_id: '18561'
  file_name: 2024_LIPIcs_ElHayek.pdf
  file_size: 809666
  relation: main_file
  success: 1
file_date_updated: 2024-11-18T08:02:45Z
has_accepted_license: '1'
intvolume: '       319'
isi: 1
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
project:
- _id: bd9e3a2e-d553-11ed-ba76-8aa684ce17fe
  grant_number: P33775
  name: Fast Algorithms for a Reactive Network Layer
- _id: bd9ca328-d553-11ed-ba76-dc4f890cfe62
  call_identifier: H2020
  grant_number: '101019564'
  name: The design and evaluation of modern fully dynamic data structures
- _id: 34def286-11ca-11ed-8bc3-da5948e1613c
  grant_number: Z00422
  name: Efficient algorithms
- _id: bda196b2-d553-11ed-ba76-8e8ee6c21103
  grant_number: I05982
  name: Static and Dynamic Hierarchical Graph Decompositions
publication: 38th International Symposium on Distributed Computing
publication_identifier:
  isbn:
  - '9783959773522'
  issn:
  - 1868-8969
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
scopus_import: '1'
status: public
title: Broadcast and Consensus in stochastic dynamic networks with Byzantine nodes
  and adversarial edges
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: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 319
year: '2024'
...
