@article{11898, abstract = {We build upon the recent papers by Weinstein and Yu (FOCS'16), Larsen (FOCS'12), and Clifford et al. (FOCS'15) to present a general framework that gives amortized lower bounds on the update and query times of dynamic data structures. Using our framework, we present two concrete results. (1) For the dynamic polynomial evaluation problem, where the polynomial is defined over a finite field of size n1+Ω(1) and has degree n, any dynamic data structure must either have an amortized update time of Ω((lgn/lglgn)2) or an amortized query time of Ω((lgn/lglgn)2). (2) For the dynamic online matrix vector multiplication problem, where we get an n×n matrix whose entires are drawn from a finite field of size nΘ(1), any dynamic data structure must either have an amortized update time of Ω((lgn/lglgn)2) or an amortized query time of Ω(n⋅(lgn/lglgn)2). For these two problems, the previous works by Larsen (FOCS'12) and Clifford et al. (FOCS'15) gave the same lower bounds, but only for worst case update and query times. Our bounds match the highest unconditional lower bounds known till date for any dynamic problem in the cell-probe model.}, author = {Bhattacharya, Sayan and Henzinger, Monika H and Neumann, Stefan}, issn = {0304-3975}, journal = {Theoretical Computer Science}, pages = {72--87}, publisher = {Elsevier}, title = {{New amortized cell-probe lower bounds for dynamic problems}}, doi = {10.1016/j.tcs.2019.01.043}, volume = {779}, year = {2019}, } @article{11957, abstract = {Cross-coupling reactions mediated by dual nickel/photocatalysis are synthetically attractive but rely mainly on expensive, non-recyclable noble-metal complexes as photocatalysts. Heterogeneous semiconductors, which are commonly used for artificial photosynthesis and wastewater treatment, are a sustainable alternative. Graphitic carbon nitrides, a class of metal-free polymers that can be easily prepared from bulk chemicals, are heterogeneous semiconductors with high potential for photocatalytic organic transformations. Here, we demonstrate that graphitic carbon nitrides in combination with nickel catalysis can induce selective C−O cross-couplings of carboxylic acids with aryl halides, yielding the respective aryl esters in excellent yield and selectivity. The heterogeneous organic photocatalyst exhibits a broad substrate scope, is able to harvest green light, and can be recycled multiple times. In situ FTIR was used to track the reaction progress to study this transformation at different irradiation wavelengths and reaction scales.}, author = {Pieber, Bartholomäus and Malik, Jamal A. and Cavedon, Cristian and Gisbertz, Sebastian and Savateev, Aleksandr and Cruz, Daniel and Heil, Tobias and Zhang, Guigang and Seeberger, Peter H.}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, number = {28}, pages = {9575--9580}, publisher = {Wiley}, title = {{Semi‐heterogeneous dual nickel/photocatalysis using carbon nitrides: Esterification of carboxylic acids with aryl halides}}, doi = {10.1002/anie.201902785}, volume = {58}, year = {2019}, } @article{11982, abstract = {A carbon nitride material can be combined with homogeneous nickel catalysts for light-mediated cross-couplings of aryl bromides with alcohols under mild conditions. The metal-free heterogeneous semiconductor is fully recyclable and couples a broad range of electron-poor aryl bromides with primary and secondary alcohols as well as water. The application for intramolecular reactions and the synthesis of active pharmaceutical ingredients was demonstrated. The catalytic protocol is applicable for the coupling of aryl iodides with thiols as well.}, author = {Cavedon, Cristian and Madani, Amiera and Seeberger, Peter H. and Pieber, Bartholomäus}, issn = {1523-7052}, journal = {Organic Letters}, number = {13}, pages = {5331--5334}, publisher = {American Chemical Society}, title = {{Semiheterogeneous dual nickel/photocatalytic (thio)etherification using carbon nitrides}}, doi = {10.1021/acs.orglett.9b01957}, volume = {21}, year = {2019}, } @article{11984, abstract = {Differentially protected galactosamine building blocks are key components for the synthesis of human and bacterial oligosaccharides. The azidophenylselenylation of 3,4,6-tri-O-acetyl-d-galactal provides straightforward access to the corresponding 2-nitrogenated glycoside. Poor reproducibility and the use of azides that lead to the formation of potentially explosive and toxic species limit the scalability of this reaction and render it a bottleneck for carbohydrate synthesis. Here, we present a method for the safe, efficient, and reliable azidophenylselenylation of 3,4,6-tri-O-acetyl-d-galactal at room temperature, using continuous flow chemistry. Careful analysis of the transformation resulted in reaction conditions that produce minimal side products while the reaction time was reduced drastically when compared to batch reactions. The flow setup is readily scalable to process 5 mmol of galactal in 3 h, producing 1.2 mmol/h of product.}, author = {Guberman, Mónica and Pieber, Bartholomäus and Seeberger, Peter H.}, issn = {1520-586X}, journal = {Organic Process Research and Development}, number = {12}, pages = {2764--2770}, publisher = {American Chemical Society}, title = {{Safe and scalable continuous flow azidophenylselenylation of galactal to prepare galactosamine building blocks}}, doi = {10.1021/acs.oprd.9b00456}, volume = {23}, year = {2019}, } @article{22028, abstract = {We prove global well-posedness of the Korteweg–de Vries equation for initial data in the space H^−1(R). This is sharp in the class of H^s(R) spaces. Even local well-posedness was previously unknown for s < −3/4. The proof is based on the introduction of a new method of general applicability for the study of low-regularity well-posedness for integrable PDE, informed by the existence of commuting flows. In particular, as we will show, completely parallel arguments give a new proof of global well-posedness for KdV with periodic H−1 data, shown previously by Kappeler and Topalov, as well as global well-posedness for the fifth order KdV equation in L^2(R). Additionally, we give a new proof of the a priori local smoothing bound of Buckmaster and Koch for KdV on the line. Moreover, we upgrade this estimate to show that convergence of initial data in H^−1(R) guarantees convergence of the resulting solutions in L^2loc(R × R). Thus, solutions with H^−1(R) initial data are distributional solutions.}, author = {Killip, Rowan and Visan, Monica}, issn = {0003-486X}, journal = {Annals of Mathematics}, number = {1}, pages = {249--305}, publisher = {Annals of Mathematics}, title = {{KdV is well-posed in H^-1}}, doi = {10.4007/annals.2019.190.1.4}, volume = {190}, year = {2019}, } @article{22030, abstract = {We consider the mass-subcritical NLS in dimensions d>=3 with radial initial data. In the defocusing case, we prove that any solution that remains bounded in the critical Sobolev space throughout its lifespan must be global and scatter. In the focusing case, we prove the existence of a threshold solution that has a compact flow.}, author = {Killip, Rowan and Masaki, Satoshi and Murphy, Jason and Visan, Monica}, issn = {1553-5231}, journal = {Discrete and Continuous Dynamical Systems}, number = {1}, pages = {553--583}, publisher = {American Institute of Mathematical Sciences}, title = {{The radial mass-subcritical NLS in negative order Sobolev spaces}}, doi = {10.3934/dcds.2019023}, volume = {39}, year = {2019}, } @article{27, abstract = {The cerebral cortex is composed of a large variety of distinct cell-types including projection neurons, interneurons and glial cells which emerge from distinct neural stem cell (NSC) lineages. The vast majority of cortical projection neurons and certain classes of glial cells are generated by radial glial progenitor cells (RGPs) in a highly orchestrated manner. Recent studies employing single cell analysis and clonal lineage tracing suggest that NSC and RGP lineage progression are regulated in a profound deterministic manner. In this review we focus on recent advances based mainly on correlative phenotypic data emerging from functional genetic studies in mice. We establish hypotheses to test in future research and outline a conceptual framework how epigenetic cues modulate the generation of cell-type diversity during cortical development. This article is protected by copyright. All rights reserved.}, author = {Amberg, Nicole and Laukoter, Susanne and Hippenmeyer, Simon}, journal = {Journal of Neurochemistry}, number = {1}, pages = {12--26}, publisher = {Wiley}, title = {{Epigenetic cues modulating the generation of cell type diversity in the cerebral cortex}}, doi = {10.1111/jnc.14601}, volume = {149}, year = {2019}, } @article{301, abstract = {A representation formula for solutions of stochastic partial differential equations with Dirichlet boundary conditions is proved. The scope of our setting is wide enough to cover the general situation when the backward characteristics that appear in the usual formulation are not even defined in the Itô sense.}, author = {Gerencser, Mate and Gyöngy, István}, journal = {Stochastic Processes and their Applications}, number = {3}, pages = {995--1012}, publisher = {Elsevier}, title = {{A Feynman–Kac formula for stochastic Dirichlet problems}}, doi = {10.1016/j.spa.2018.04.003}, volume = {129}, year = {2019}, } @article{12190, abstract = {Meiotic crossover frequency varies within genomes, which influences genetic diversity and adaptation. In turn, genetic variation within populations can act to modify crossover frequency in cis and trans. To identify genetic variation that controls meiotic crossover frequency, we screened Arabidopsis accessions using fluorescent recombination reporters. We mapped a genetic modifier of crossover frequency in Col × Bur populations of Arabidopsis to a premature stop codon within TBP-ASSOCIATED FACTOR 4b (TAF4b), which encodes a subunit of the RNA polymerase II general transcription factor TFIID. The Arabidopsis taf4b mutation is a rare variant found in the British Isles, originating in South-West Ireland. Using genetics, genomics, and immunocytology, we demonstrate a genome-wide decrease in taf4b crossovers, with strongest reduction in the sub-telomeric regions. Using RNA sequencing (RNA-seq) from purified meiocytes, we show that TAF4b expression is meiocyte enriched, whereas its paralog TAF4 is broadly expressed. Consistent with the role of TFIID in promoting gene expression, RNA-seq of wild-type and taf4b meiocytes identified widespread transcriptional changes, including in genes that regulate the meiotic cell cycle and recombination. Therefore, TAF4b duplication is associated with acquisition of meiocyte-specific expression and promotion of germline transcription, which act directly or indirectly to elevate crossovers. This identifies a novel mode of meiotic recombination control via a general transcription factor.}, author = {Lawrence, Emma J. and Gao, Hongbo and Tock, Andrew J. and Lambing, Christophe and Blackwell, Alexander R. and Feng, Xiaoqi and Henderson, Ian R.}, issn = {0960-9822}, journal = {Current Biology}, keywords = {General Agricultural and Biological Sciences, General Biochemistry, Genetics and Molecular Biology}, number = {16}, pages = {2676--2686.e3}, publisher = {Elsevier}, title = {{Natural variation in TBP-ASSOCIATED FACTOR 4b controls meiotic crossover and germline transcription in Arabidopsis}}, doi = {10.1016/j.cub.2019.06.084}, volume = {29}, year = {2019}, } @article{12192, abstract = {Transposable elements (TEs), the movement of which can damage the genome, are epigenetically silenced in eukaryotes. Intriguingly, TEs are activated in the sperm companion cell – vegetative cell (VC) – of the flowering plant Arabidopsis thaliana. However, the extent and mechanism of this activation are unknown. Here we show that about 100 heterochromatic TEs are activated in VCs, mostly by DEMETER-catalyzed DNA demethylation. We further demonstrate that DEMETER access to some of these TEs is permitted by the natural depletion of linker histone H1 in VCs. Ectopically expressed H1 suppresses TEs in VCs by reducing DNA demethylation and via a methylation-independent mechanism. We demonstrate that H1 is required for heterochromatin condensation in plant cells and show that H1 overexpression creates heterochromatic foci in the VC progenitor cell. Taken together, our results demonstrate that the natural depletion of H1 during male gametogenesis facilitates DEMETER-directed DNA demethylation, heterochromatin relaxation, and TE activation.}, author = {He, Shengbo and Vickers, Martin and Zhang, Jingyi and Feng, Xiaoqi}, issn = {2050-084X}, journal = {eLife}, keywords = {General Immunology and Microbiology, General Biochemistry, Genetics and Molecular Biology, General Medicine, General Neuroscience}, publisher = {eLife Sciences Publications}, title = {{Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation}}, doi = {10.7554/elife.42530}, volume = {8}, year = {2019}, } @article{12600, abstract = {The snow cover dynamics of High Mountain Asia are usually assessed at spatial resolutions of 250 m or greater, but this scale is too coarse to clearly represent the rugged topography common to the region. Higher-resolution measurement of snow-covered area often results in biased sampling due to cloud cover and deep shadows. We therefore develop a Normalized Difference Snow Index-based workflow to delineate snow lines from Landsat Thematic Mapper/Enhanced Thematic Mapper+ imagery and apply it to the upper Langtang Valley in Nepal, processing 194 scenes spanning 1999 to 2013. For each scene, we determine the spatial distribution of snow line altitudes (SLAs) with respect to aspect and across six subcatchments. Our results show that the mean SLA exhibits distinct seasonal behavior based on aspect and subcatchment position. We find that SLA dynamics respond to spatial and seasonal trade-offs in precipitation, temperature, and solar radiation, which act as primary controls. We identify two SLA spatial gradients, which we attribute to the effect of spatially variable precipitation. Our results also reveal that aspect-related SLA differences vary seasonally and are influenced by solar radiation. In terms of seasonal dominant controls, we demonstrate that the snow line is controlled by snow precipitation in winter, melt in premonsoon, a combination of both in postmonsoon, and temperature in monsoon, explaining to a large extent the spatial and seasonal variability of the SLA in the upper Langtang Valley. We conclude that while SLA and snow-covered area are complementary metrics, the SLA has a strong potential for understanding local-scale snow cover dynamics and their controlling mechanisms.}, author = {Girona‐Mata, Marc and Miles, Evan S. and Ragettli, Silvan and Pellicciotti, Francesca}, issn = {1944-7973}, journal = {Water Resources Research}, keywords = {Water Science and Technology}, number = {8}, pages = {6754--6772}, publisher = {American Geophysical Union}, title = {{High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment}}, doi = {10.1029/2019wr024935}, volume = {55}, year = {2019}, } @article{12601, abstract = {Ice cliffs and ponds on debris-covered glaciers have received increased attention due to their role in amplifying local melt. However, very few studies have looked at these features on the catchment scale to determine their patterns and changes in space and time. We have compiled a detailed inventory of cliffs and ponds in the Langtang catchment, central Himalaya, from six high-resolution satellite orthoimages and DEMs between 2006 and 2015, and a historic orthophoto from 1974. Cliffs cover between 1.4% (± 0.4%) in the dry and 3.4% (± 0.9%) in the wet seasons and ponds between 0.6% (± 0.1%) and 1.6% (± 0.3%) of the total debris-covered tongues. We find large variations between seasons, as cliffs and ponds tend to grow in the wetter monsoon period, but there is no obvious trend in total area over the study period. The inventory further shows that cliffs are predominately north-facing irrespective of the glacier flow direction. Both cliffs and ponds appear in higher densities several hundred metres from the terminus in areas where tributaries reach the main glacier tongue. On the largest glacier in the catchment ~10% of all cliffs and ponds persisted over nearly a decade.}, author = {STEINER, JAKOB F. and BURI, PASCAL and MILES, EVAN S. and RAGETTLI, SILVAN and Pellicciotti, Francesca}, issn = {1727-5652}, journal = {Journal of Glaciology}, number = {252}, pages = {617--632}, publisher = {Cambridge University Press}, title = {{Supraglacial ice cliffs and ponds on debris-covered glaciers: Spatio-temporal distribution and characteristics}}, doi = {10.1017/jog.2019.40}, volume = {65}, year = {2019}, } @article{12602, abstract = {This study aims at developing and applying a spatially-distributed coupled glacier mass balance and ice-flow model to attribute the response of glaciers to natural and anthropogenic climate change. We focus on two glaciers with contrasting surface characteristics: a debris-covered glacier (Langtang Glacier in Nepal) and a clean-ice glacier (Hintereisferner in Austria). The model is applied from the end of the Little Ice Age (1850) to the present-day (2016) and is forced with four bias-corrected General Circulation Models (GCMs) from the historical experiment of the CMIP5 archive. The selected GCMs represent region-specific warm-dry, warm-wet, cold-dry, and cold-wet climate conditions. To isolate the effects of anthropogenic climate change on glacier mass balance and flow runs from these GCMs with and without further anthropogenic forcing after 1970 until 2016 are selected. The outcomes indicate that both glaciers experience the largest reduction in area and volume under warm climate conditions, whereas area and volume reductions are smaller under cold climate conditions. Simultaneously with changes in glacier area and volume, surface velocities generally decrease over time. Without further anthropogenic forcing the results reveal a 3% (9%) smaller decline in glacier area (volume) for the debris-covered glacier and a 18% (39%) smaller decline in glacier area (volume) for the clean-ice glacier. The difference in the magnitude between the two glaciers can mainly be attributed to differences in the response time of the glaciers, where the clean-ice glacier shows a much faster response to climate change. We conclude that the response of the two glaciers can mainly be attributed to anthropogenic climate change and that the impact is larger on the clean-ice glacier. The outcomes show that the model performs well under different climate conditions and that the developed approach can be used for regional-scale glacio-hydrological modeling.}, author = {Wijngaard, René R. and Steiner, Jakob F. and Kraaijenbrink, Philip D. A. and Klug, Christoph and Adhikari, Surendra and Banerjee, Argha and Pellicciotti, Francesca and van Beek, Ludovicus P. H. and Bierkens, Marc F. P. and Lutz, Arthur F. and Immerzeel, Walter W.}, issn = {2296-6463}, journal = {Frontiers in Earth Science}, publisher = {Frontiers Media}, title = {{Modeling the response of the Langtang Glacier and the Hintereisferner to a changing climate since the Little Ice Age}}, doi = {10.3389/feart.2019.00143}, volume = {7}, year = {2019}, } @inproceedings{12901, author = {Schlögl, Alois and Kiss, Janos and Elefante, Stefano}, booktitle = {AHPC19 - Austrian HPC Meeting 2019 }, location = {Grundlsee, Austria}, pages = {25}, publisher = {Institut für Mathematik und wissenschaftliches Rechnen der Universität Graz}, title = {{Is Debian suitable for running an HPC Cluster?}}, year = {2019}, } @misc{13067, abstract = {Genetic incompatibilities contribute to reproductive isolation between many diverging populations, but it is still unclear to what extent they play a role if divergence happens with gene flow. In contact zones between the "Crab" and "Wave" ecotypes of the snail Littorina saxatilis divergent selection forms strong barriers to gene flow, while the role of postzygotic barriers due to selection against hybrids remains unclear. High embryo abortion rates in this species could indicate the presence of such barriers. Postzygotic barriers might include genetic incompatibilities (e.g. Dobzhansky-Muller incompatibilities) but also maladaptation, both expected to be most pronounced in contact zones. In addition, embryo abortion might reflect physiological stress on females and embryos independent of any genetic stress. We examined all embryos of >500 females sampled outside and inside contact zones of three populations in Sweden. Females' clutch size ranged from 0 to 1011 embryos (mean 130±123) and abortion rates varied between 0 and100% (mean 12%). We described female genotypes by using a hybrid index based on hundreds of SNPs differentiated between ecotypes with which we characterised female genotypes. We also calculated female SNP heterozygosity and inversion karyotype. Clutch size did not vary with female hybrid index and abortion rates were only weakly related to hybrid index in two sites but not at all in a third site. No additional variation in abortion rate was explained by female SNP heterozygosity, but increased female inversion heterozygosity added slightly to increased abortion. Our results show only weak and probably biologically insignificant postzygotic barriers contributing to ecotype divergence and the high and variable abortion rates were marginally, if at all, explained by hybrid index of females.}, author = {Johannesson, Kerstin and Zagrodzka, Zuzanna and Faria, Rui and Westram, Anja M and Butlin, Roger}, publisher = {Dryad}, title = {{Data from: Is embryo abortion a postzygotic barrier to gene flow between Littorina ecotypes?}}, doi = {10.5061/DRYAD.TB2RBNZWK}, year = {2019}, } @misc{13079, abstract = {The inner nuclear membrane (INM) is a subdomain of the endoplasmic reticulum (ER) that is gated by the nuclear pore complex. It is unknown whether proteins of the INM and ER are degraded through shared or distinct pathways in mammalian cells. We applied dynamic proteomics to profile protein half-lives and report that INM and ER residents turn over at similar rates, indicating that the INM’s unique topology is not a barrier to turnover. Using a microscopy approach, we observed that the proteasome can degrade INM proteins in situ. However, we also uncovered evidence for selective, vesicular transport-mediated turnover of a single INM protein, emerin, that is potentiated by ER stress. Emerin is rapidly cleared from the INM by a mechanism that requires emerin’s LEM domain to mediate vesicular trafficking to lysosomes. This work demonstrates that the INM can be dynamically remodeled in response to environmental inputs.}, author = {Buchwalter, Abigail and Schulte, Roberta and Tsai, Hsiao and Capitanio, Juliana and HETZER, Martin W}, publisher = {Dryad}, title = {{Data from: Selective clearance of the inner nuclear membrane protein emerin by vesicular transport during ER stress}}, doi = {10.5061/DRYAD.N0R525H}, year = {2019}, } @article{21095, abstract = {Inspired by DNA mimic proteins, we have introduced aromatic foldamers bearing phosphonate groups as synthetic mimics of the charge surface of B-DNA and competitive inhibitors of some therapeutically relevant DNA-binding enzymes: the human DNA Topoisomerase 1 (Top1) and the human HIV-1 integrase (HIV-1 IN). We now report on variants of these anionic foldamers bearing carboxylates instead of phosphonates. Several new monomers have been synthesized with protecting groups suitable for solid phase synthesis (SPS). Six hexadecaamides have been prepared using SPS. Proof of their resemblance to B-DNA was brought by the first crystal structure of one of these DNA-mimic foldamers in its polyanionic form. While some of the foldamers were found to be as active as, or even more active than, the original phosphonate oligomers, others had no activity at all or could even stimulate enzyme activity in vitro. Some foldamers were found to have differential inhibitory effects on the two enzymes. These results demonstrate a strong dependence of inhibitory activity on foldamer structure and charge distribution. They open broad avenues for the development of new classes of derivatives that could inhibit the interaction of specific proteins with their DNA target thereby influencing the cellular pathways in which they are involved.}, author = {Corvaglia, Valentina and Carbajo, Daniel and Prabhakaran, Panchami and Ziach, Krzysztof and Mandal, Pradeep K and Santos, Victor Dos and Legeay, Carole and Vogel, Rachel and Parissi, Vincent and Pourquier, Philippe and Huc, Ivan}, issn = {1362-4962}, journal = {Nucleic Acids Research}, number = {11}, pages = {5511--5521}, publisher = {Oxford University Press}, title = {{Carboxylate-functionalized foldamer inhibitors of HIV-1 integrase and Topoisomerase 1: Artificial analogues of DNA mimic proteins}}, doi = {10.1093/nar/gkz352}, volume = {47}, year = {2019}, } @article{21538, abstract = {Extracting light from silicon is a longstanding challenge in modern engineering and physics. While silicon has underpinned the past 70 years of electronics advancement, a facile tunable and efficient silicon-based light source remains elusive. Here, we experimentally demonstrate the generation of tunable radiation from a one-dimensional, all-silicon nanograting. Light is generated by the spontaneous emission from the interaction of these nanogratings with low-energy free electrons (2–20 keV) and is recorded in the wavelength range of 800–1600 nm, which includes the silicon transparency window. Tunable free-electron-based light generation from nanoscale silicon gratings with efficiencies approaching those from metallic gratings is demonstrated. We theoretically investigate the feasibility of a scalable, compact, all-silicon tunable light source comprised of a silicon Field Emitter Array integrated with a silicon nanograting that emits at telecommunication wavelengths. Our results reveal the prospects of a CMOS-compatible electrically-pumped silicon light source for possible applications in the mid-infrared and telecommunication wavelengths.}, author = {Roques-Carmes, Charles and Kooi, Steven E. and Yang, Yi and Massuda, Aviram and Keathley, Phillip D. and Zaidi, Aun and Yang, Yujia and Joannopoulos, John D. and Berggren, Karl K. and Kaminer, Ido and Soljačić, Marin}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Towards integrated tunable all-silicon free-electron light sources}}, doi = {10.1038/s41467-019-11070-7}, volume = {10}, year = {2019}, } @article{21557, abstract = {A new optical processor for solving hard optimization problems breaks previous size records and is based on a highly scalable technology. }, author = {Roques-Carmes, Charles and Soljačić, Marin}, issn = {1943-2879}, journal = {Physics}, publisher = {American Physical Society}, title = {{Photonic ising machines go big}}, doi = {10.1103/physics.12.61}, volume = {12}, year = {2019}, } @inproceedings{21568, abstract = {Optical approaches to AI acceleration have gained intense interest recently due to the potentially breakthrough advantages of photonics: high bandwidth, low power consumption, and efficient data movement. We overview leading photonic AI platforms based on beamsplitter mesh networks, weight banks, and photoelectric multiplication. While the theoretical performance can be orders of magnitude beyond current state of the art, practical issues of chip area, input / output, and crosstalk paint a more nuanced near-term picture of photonic AI acceleration. Both fundamental and near-term limitations to energy efficiency are addressed, and bandwidth limitations due to temporal crosstalk are analyzed.}, author = {Hamerly, R. and Sludds, A. and Bernstein, L. and Prabhu, M. and Roques-Carmes, Charles and Carolan, J. and Yamamoto, Y. and Soljacic, M. and Englund, D.}, booktitle = {2019 IEEE International Electron Devices Meeting}, issn = {2156-017X}, location = {San Francisco, CA, United States}, publisher = {IEEE}, title = {{Towards large-scale photonic neural-network accelerators}}, doi = {10.1109/iedm19573.2019.8993624}, year = {2019}, }