@article{18527,
abstract = {Context. Galaxies evolve through a dynamic exchange of material with their immediate surrounding environment, the so-called circumgalactic medium (CGM). Understanding the physics of gas flows and the nature of the CGM is fundamental to studying galaxy evolution, especially at 4 ≤ z ≤ 6 (i.e., after the Epoch of Reionization) when galaxies rapidly assembled their masses and reached their chemical maturity. Galactic outflows are predicted to enrich the CGM with metals, although it has also been suggested that gas stripping in systems undergoing a major merger may play a role.
Aims. In this work, we explore the metal enrichment of the medium around merging galaxies at z ∼ 4.5, observed by the ALMA Large Program to INvestigate [CII] at Early times (ALPINE). To do so, we study the nature of the [CII] 158 μm emission in the CGM around these systems, using simulations to help disentangle the mechanisms contributing to the CGM metal pollution.
Methods. By adopting an updated classification of major merger systems in the ALPINE survey, we selected and analyzed merging galaxies whose components can be spatially and/or spectrally resolved in a robust way. This makes it possible to distinguish between the [CII] emission coming from the single components of the system and that coming from the system as a whole. We also made use of the dustyGadget cosmological simulation to select synthetic analogs of observed galaxies and guide the interpretation of the observational results.
Results. We find a large diffuse [CII] envelope (≳20 kpc) embedding all the merging systems, with at least 25% of the total [CII] emission coming from the medium between the galaxies. Using predictions from dustyGadget, we suggest that this emission has a multi-fold nature, with dynamical interactions between galaxies playing a major role in stripping the gas and enriching the medium with heavy elements.},
author = {Di Cesare, Claudia and Ginolfi, M. and Graziani, L. and Schneider, R. and Romano, M. and Popping, G.},
issn = {1432-0746},
journal = {Astronomy & Astrophysics},
publisher = {EDP Sciences},
title = {{Carbon envelopes around merging galaxies at z ~ 4.5}},
doi = {10.1051/0004-6361/202449164},
volume = {690},
year = {2024},
}
@article{22154,
abstract = {The inertia bound and ratio bound (also known as the Cvetković bound and Hoffman bound) are two fundamental inequalities in spectral graph theory, giving upper bounds on the independence number a(G) of a graph G in terms of spectral information about a weighted adjacency matrix of G. For both inequalities, given a graph G, one needs to make a judicious choice of weighted adjacency matrix to obtain as strong a bound as possible. While there is a well‐established theory surrounding the ratio bound, the inertia bound is much more mysterious, and its limits are rather unclear. In fact, only recently did Sinkovic find the first example of a graph for which the inertia bound is not tight (for any weighted adjacency matrix), answering a longstanding question of Godsil. We show that the inertia bound can be extremely far from tight, and in fact can significantly underperform the ratio bound: for example, one of our results is that for infinitely many n, there is an n‐vertex graph for which even the unweighted ratio bound can prove a(G)<4n^3/4, but the inertia bound is always at least n/4. In particular, these results address questions of Rooney, Sinkovic, and Wocjan–Elphick–Abiad.},
author = {Kwan, Matthew and Wigderson, Yuval},
issn = {1469-2120},
journal = {Bulletin of the London Mathematical Society},
number = {10},
pages = {3196--3208},
publisher = {Wiley},
title = {{The inertia bound is far from tight}},
doi = {10.1112/blms.13127},
volume = {56},
year = {2024},
}
@article{14980,
abstract = {Precision sensing and manipulation of milligram-scale mechanical oscillators has attracted growing interest in the fields of table-top explorations of gravity and tests of quantum mechanics at macroscopic scales. Torsional oscillators present an opportunity in this regard due to their remarked isolation from environmental noise. For torsional motion, an effective employment of optical cavities to enhance optomechanical interactions—as already established for linear oscillators—so far faced certain challenges. Here, we propose a concept for sensing and manipulating torsional motion, where exclusively the torsional rotations of a pendulum are mapped onto the path length of a single two-mirror optical cavity. The concept inherently alleviates many limitations of previous approaches. A proof-of-principle experiment is conducted with a rigidly controlled pendulum to explore the sensing aspects of the concept and to identify practical limitations in a potential state-of-the art setup. Based on this study, we anticipate development of precision torque sensors utilizing torsional pendulums that can support sensitivities below 10−19Nm/√Hz, while the motion of the pendulums are dominated by quantum radiation pressure noise at sub-microwatts of incoming laser power. These developments will provide horizons for experiments at the interface of quantum mechanics and gravity.},
author = {Agafonova, Sofya and Mishra, Umang and Diorico, Fritz R and Hosten, Onur},
issn = {2643-1564},
journal = {Physical Review Research},
number = {1},
publisher = {American Physical Society},
title = {{Zigzag optical cavity for sensing and controlling torsional motion}},
doi = {10.1103/physrevresearch.6.013141},
volume = {6},
year = {2024},
}
@article{14802,
abstract = {Frequency-stable lasers form the back bone of precision measurements in science and technology. Such lasers typically attain their stability through frequency locking to reference cavities. State-of-the-art locking performances to date had been achieved using frequency modulation based methods, complemented with active drift cancellation systems. We demonstrate an all passive, modulation-free laser-cavity locking technique (squash locking) that utilizes changes in spatial beam ellipticity for error signal generation, and a coherent polarization post-selection for noise resilience. By comparing two identically built proof-of-principle systems, we show a frequency locking instability of 5×10−7 relative to the cavity linewidth at 10 s averaging. The results surpass the demonstrated performances of methods engineered over the last five decades, potentially enabling an advancement in the precision control of lasers, while creating avenues for bridging the performance gaps between industrial grade lasers with scientific ones due to the afforded simplicity and scalability.},
author = {Diorico, Fritz R and Zhutov, Artem and Hosten, Onur},
issn = {2334-2536},
journal = {Optica},
keywords = {Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials},
number = {1},
pages = {26--31},
publisher = {Optica Publishing Group},
title = {{Laser-cavity locking utilizing beam ellipticity: accessing the 10−7 instability scale relative to cavity linewidth}},
doi = {10.1364/optica.507451},
volume = {11},
year = {2024},
}
@phdthesis{17225,
abstract = {This thesis describes the development of an atom interferometer designed to exploit the
advantages of utilizing quantum entanglement for enhanced precision measurements beyond
the standard quantum limit. While the project remains ongoing, significant progress has been
made.
A key contribution of this work is the development of Quantrol, an experimental control
system leveraging the ARTIQ framework. This software enables precise timing and control
without requiring prior knowledge of ARTIQ’s implementation details or coding experience.
The interface offers user friendly visual comprehension of the experimental sequence and
extended capabilities, allowing researchers to scan variables with a simple click of a mouse.
The main proposed project is to implement atom interferometric sequence with squeezed input
states inside of a dipole trap generated by a high finesse cavity. The presence of the dipole
trap allows one dimensional atomic cloud split while maintaining relatively strong confinement
in other directions.
We are currently able to trap and cool 87Rb atoms to few micro kelvin temperatures, load
them into the dipole trap and state prepare them to be used for squeezing and interferometric
sequence.},
author = {Li, Vyacheslav},
issn = {2663-337X},
pages = {79},
publisher = {Institute of Science and Technology Austria},
title = {{Towards a quantum entanglement enhanced atom interferomter}},
doi = {10.15479/at:ista:17225},
year = {2024},
}
@article{15169,
abstract = {Interpretation of extracellular recordings can be challenging due to the long range of electric field. This challenge can be mitigated by estimating the current source density (CSD). Here we introduce kCSD-python, an open Python package implementing Kernel Current Source Density (kCSD) method and related tools to facilitate CSD analysis of experimental data and the interpretation of results. We show how to counter the limitations imposed by noise and assumptions in the method itself. kCSD-python allows CSD estimation for an arbitrary distribution of electrodes in 1D, 2D, and 3D, assuming distributions of sources in tissue, a slice, or in a single cell, and includes a range of diagnostic aids. We demonstrate its features in a Jupyter Notebook tutorial which illustrates a typical analytical workflow and main functionalities useful in validating analysis results.},
author = {Chintaluri, Chaitanya and Bejtka, Marta and Sredniawa, Wladyslaw and Czerwinski, Michal and Dzik, Jakub M. and Jedrzejewska-Szmek, Joanna and Wojciki, Daniel K.},
issn = {1553-7358},
journal = {PLoS Computational Biology},
number = {3},
publisher = {Public Library of Science},
title = {{kCSD-python, reliable current source density estimation with quality control}},
doi = {10.1371/journal.pcbi.1011941},
volume = {20},
year = {2024},
}
@inproceedings{17147,
abstract = {Efficient utilization of large-scale biobank data is crucial for inferring the genetic basis of disease and predicting health outcomes from the DNA. Yet we lack efficient, accurate methods that scale to data where electronic health records are linked to whole genome sequence information. To address this issue, our paper develops a new algorithmic paradigm based on Approximate Message Passing (AMP), which is specifically tailored for genomic prediction and association testing. Our method yields comparable out-of-sample prediction accuracy to the state of the art on UK Biobank traits, whilst dramatically improving computational complexity, with a 8x-speed up in the run time. In addition, AMP theory provides a joint association testing framework, which outperforms the currently used REGENIE method, in roughly a third of the compute time. This first, truly large-scale application of the AMP framework lays the foundations for a far wider range of statistical analyses for hundreds of millions of variables measured on millions of people.},
author = {Depope, Al and Mondelli, Marco and Robinson, Matthew Richard},
booktitle = {2024 IEEE International Conference on Acoustics, Speech, and Signal Processing},
isbn = {9798350344851},
issn = {1520-6149},
location = {Seoul, Korea},
pages = {13151--13155},
publisher = {IEEE},
title = {{Inference of genetic effects via approximate message passing}},
doi = {10.1109/ICASSP48485.2024.10447198},
year = {2024},
}
@article{22179,
abstract = {Burr and Erd˝os in 1975 conjectured, and Chv´atal, R¨odl, Szemer´edi and
Trotter later proved, that the Ramsey number of any bounded degree
graph is linear in the number of vertices. In this paper, we disprove
the natural directed analogue of the Burr–Erd˝os conjecture, answering a
question of Buci´c, Letzter, and Sudakov. If H is an acyclic digraph, the
oriented Ramsey number of H, denoted −→r1(H), is the least N such that
every tournament on N vertices contains a copy of H. We show that for
any Δ ≥ 2 and any sufficiently large n, there exists an acyclic digraph H
with n vertices and maximum degree Δ such that
−→r1(H) ≥ nΩ(Δ2/3/ log5/3 Δ).
This proves that −→r1(H) is not always linear in the number of vertices for
bounded-degree H. On the other hand, we show that −→r1(H) is nearly linear
in the number of vertices for typical bounded-degree acyclic digraphs H,
and obtain linear or nearly linear bounds for several natural families of
bounded-degree acyclic digraphs.
For multiple colors, we prove a quasi-polynomial upper bound −→rk(H)=
2(log n)Ok(1) for all bounded-degree acyclic digraphs H on n vertices, where −→rk(H) is the least N such that every k-edge-colored tournament on N
vertices contains a monochromatic copy of H. For k ≥ 2 and n ≥ 4, we
exhibit an acyclic digraph H with n vertices and maximum degree 3 such
that −→rk(H) ≥ nΩ(log n/ log log n), showing that these Ramsey numbers can
grow faster than any polynomial in the number of vertices.},
author = {Fox, Jacob and He, Xiaoyu and Wigderson, Yuval},
issn = {1565-8511},
journal = {Israel Journal of Mathematics},
number = {1},
pages = {1--48},
publisher = {Springer Nature},
title = {{Ramsey numbers of sparse digraphs}},
doi = {10.1007/s11856-024-2624-y},
volume = {263},
year = {2024},
}
@article{22180,
abstract = {Given a graph , its Ramsey number is the minimum so that every two‐coloring of contains a monochromatic copy of . It was conjectured by Conlon, Fox, and Sudakov that if one deletes a single vertex from , the Ramsey number can change by at most a constant factor. We disprove this conjecture, exhibiting an infinite family of graphs such that deleting a single vertex from each decreases the Ramsey number by a super‐constant factor. One consequence of this result is the following. There exists a family of graphs so that in any Ramsey coloring for (i.e., a coloring of a clique on vertices with no monochromatic copy of ), one of the color classes has density .},
author = {Wigderson, Yuval},
issn = {1097-0118},
journal = {Journal of Graph Theory},
number = {3},
pages = {663--675},
publisher = {Wiley},
title = {{Ramsey numbers upon vertex deletion}},
doi = {10.1002/jgt.23093},
volume = {106},
year = {2024},
}
@article{22190,
abstract = {We consider the set of 𝑚×𝑛 matrices with rational entries having numerator and denominator of size at most H and obtain various upper bounds on the number of such matrices of a given rank, or with a given determinant, or a given characteristic polynomial. We also consider similar questions for matrices whose entries are Egyptian fractions.},
author = {Afifurrahman, Muhammad and Kuperberg, Vivian Zieve and Ostafe, Alina and Shparlinski, Igor E.},
issn = {1435-5337},
journal = {Forum Mathematicum},
number = {4},
publisher = {De Gruyter},
title = {{Statistics of ranks, determinants and characteristic polynomials of rational matrices}},
doi = {10.1515/forum-2024-0114},
volume = {37},
year = {2024},
}
@article{22197,
abstract = {We study the distribution of consecutive sums of two squares
in arithmetic progressions. If {En}n∈N is the sequence of
sums of two squares in increasing order, we show that for
any modulus q and any congruence classes a1, a2, a3 mod q
which are admissible in the sense that there are solutions
to x2 + y2 ≡ ai mod q, there exist infinitely many n with
En+i−1 ≡ ai mod q, for i =1, 2, 3. We also show that for
any r1, r2 ≥ 1, there exist infinitely many n with En+i−1 ≡
a1 mod q for 1 ≤ i ≤ r1 and En+i−1 ≡ a2 mod q for
r1 +1 ≤ i ≤ r1 + r2},
author = {Kimmel, Noam and Kuperberg, Vivian Zieve},
issn = {0022-314X},
journal = {Journal of Number Theory},
pages = {135--147},
publisher = {Elsevier},
title = {{Consecutive runs of sums of two squares}},
doi = {10.1016/j.jnt.2024.05.003},
volume = {264},
year = {2024},
}
@article{22209,
abstract = {The curvature of elongated microscopic building blocks plays a crucial role on their self-assembly into orientationally ordered phases. While rod-like molecules form a handful of liquid crystal (LC) phases, curved or banana-shaped molecules show more than fifty phases, with fascinating physical properties, such as chirality or polarity. Despite the fundamental and technological importance of these so-called ‘banana-shaped liquid crystals’, little is known about their microscopic details at the single-molecule level. Curved colloidal liquid crystals—liquid crystals formed by curved colloidal rods—are excellent model systems to optically resolve the structure and dynamics of curved building blocks within these condensed phases. Recent advances in the synthesis of curved rod-like particles have unlocked the potential for studying—at the single-particle level—the intimate relationship between shape and phase symmetry, and even confirmed the stability of elusive LC phases. Further developments in this nascent field promise exciting findings, such as the first observation of the colloidal twist-bend nematic phase or the fabrication of functional materials with curvature-dependent properties. In this Report on Progress, we will highlight recent advances in the synthesis and assembly of curved colloidal liquid crystals and discuss the upcoming challenges and opportunities of this field.},
author = {Fernández-Rico, Carla and Dullens, Roel P A},
issn = {1361-6633},
journal = {Reports on Progress in Physics},
number = {9},
publisher = {IOP Publishing},
title = {{Liquid crystals from curved colloidal rods: Waves, twists and more}},
doi = {10.1088/1361-6633/ad627b},
volume = {87},
year = {2024},
}
@article{22219,
abstract = {Bicontinuous microstructures are essential to the function of diverse natural and synthetic systems. Their synthesis has been based on two approaches: arrested phase separation or self-assembly of block copolymers. The former is attractive for its chemical simplicity and the latter, for its thermodynamic robustness. Here we introduce elastic microphase separation (EMPS) as an alternative approach to make bicontinuous microstructures. Conceptually, EMPS balances the molecular-scale forces that drive demixing with large-scale elasticity to encode a thermodynamic length scale. This process features a continuous phase transition, reversible without hysteresis. Practically, EMPS is triggered by simply supersaturating an elastomeric matrix with a liquid, resulting in uniform bicontinuous materials with a well-defined microscopic length scale tuned by the matrix stiffness. The versatility of EMPS is further demonstrated by fabricating bicontinuous materials with superior mechanical properties and controlled anisotropy and microstructural gradients. Overall, EMPS presents a robust alternative for the bulk fabrication of homogeneous bicontinuous materials.},
author = {Fernández-Rico, Carla and Schreiber, Sanjay and Oudich, Hamza and Lorenz, Charlotta and Sicher, Alba and Sai, Tianqi and Bauernfeind, Viola and Heyden, Stefanie and Carrara, Pietro and Lorenzis, Laura De and Style, Robert W. and Dufresne, Eric R.},
issn = {1476-4660},
journal = {Nature Materials},
pages = {124--130},
publisher = {Springer Nature},
title = {{Elastic microphase separation produces robust bicontinuous materials}},
doi = {10.1038/s41563-023-01703-0},
volume = {23},
year = {2024},
}
@article{15182,
abstract = {Thermoelectric materials convert heat into electricity, with a broad range of applications near room temperature (RT). However, the library of RT high-performance materials is limited. Traditional high-temperature synthetic methods constrain the range of materials achievable, hindering the ability to surpass crystal structure limitations and engineer defects. Here, a solution-based synthetic approach is introduced, enabling RT synthesis of powders and exploration of densification at lower temperatures to influence the material's microstructure. The approach is exemplified by Ag2Se, an n-type alternative to bismuth telluride. It is demonstrated that the concentration of Ag interstitials, grain boundaries, and dislocations are directly correlated to the sintering temperature, and achieve a figure of merit of 1.1 from RT to 100 °C after optimization. Moreover, insights into and resolve Ag2Se's challenges are provided, including stoichiometry issues leading to irreproducible performances. This work highlights the potential of RT solution synthesis in expanding the repertoire of high-performance thermoelectric materials for practical applications.},
author = {Kleinhanns, Tobias and Milillo, Francesco and Calcabrini, Mariano and Fiedler, Christine and Horta, Sharona and Balazs, Daniel and Strumolo, Marissa J. and Hasler, Roger and Llorca, Jordi and Tkadletz, Michael and Brutchey, Richard L. and Ibáñez, Maria},
issn = {1614-6840},
journal = {Advanced Energy Materials},
number = {22},
publisher = {Wiley},
title = {{A route to high thermoelectric performance: Solution‐based control of microstructure and composition in Ag2Se}},
doi = {10.1002/aenm.202400408},
volume = {14},
year = {2024},
}
@article{18951,
abstract = {We consider local dynamics of the dimer model (perfect matchings) on hypercubic boxes [n]
d . These consist of successively switching the dimers along alternating cycles of prescribed (small) lengths. We study the connectivity properties of the dimer configuration space equipped with these transitions. Answering a question of Freire, Klivans, Milet, and Saldanha, we show that in three dimensions any configuration admits an alternating cycle of length at most 6. We further establish that any configuration on [n] d features order n d−2 alternating cycles of length at most 4d−2. We also prove that the dynamics of dimer configurations on the unit hypercube of dimension d is ergodic when switching alternating cycles of length at most 4d−4. Finally, in the planar but non-bipartite case, we show that parallelogram-shaped boxes in the triangular lattice are ergodic for switching alternating cycles of lengths 4 and 6 only, thus improving a result of Kenyon and Rémila, which also uses 8-cycles. None of our proofs make reference to height functions.},
author = {Hartarsky, Ivailo and Lichev, Lyuben and Toninelli, Fabio Lucio},
issn = {2308-5835},
journal = {Annales de l’Institut Henri Poincaré D, Combinatorics, Physics and their Interactions},
publisher = {EMS Press},
title = {{Local dimer dynamics in higher dimensions}},
doi = {10.4171/aihpd/200},
year = {2024},
}
@inproceedings{18917,
abstract = {An eight-partition of a finite set of points (respectively, of a continuous mass distribution) in ℝ³ consists of three planes that divide the space into 8 octants, such that each open octant contains at most 1/8 of the points (respectively, of the mass). In 1966, Hadwiger showed that any mass distribution in ℝ³ admits an eight-partition; moreover, one can prescribe the normal direction of one of the three planes. The analogous result for finite point sets follows by a standard limit argument.
We prove the following variant of this result: Any mass distribution (or point set) in ℝ³ admits an eight-partition for which the intersection of two of the planes is a line with a prescribed direction.
Moreover, we present an efficient algorithm for calculating an eight-partition of a set of n points in ℝ³ (with prescribed normal direction of one of the planes) in time O^*(n^{5/2}).},
author = {Aronov, Boris and Basit, Abdul and Ramesh, Indu and Tasinato, Gianluca and Wagner, Uli},
booktitle = {40th International Symposium on Computational Geometry},
isbn = {9783959773164},
location = {Athens, Greece},
pages = {8:1--8:15},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Eight-partitioning points in 3D, and efficiently too}},
doi = {10.4230/LIPIcs.SoCG.2024.8},
volume = {293},
year = {2024},
}
@inproceedings{18557,
abstract = {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.},
author = {El-Hayek, Antoine and Henzinger, Monika H and Schmid, Stefan},
booktitle = {38th International Symposium on Distributed Computing},
isbn = {9783959773522},
issn = {1868-8969},
location = {Madrid, Spain},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Broadcast and Consensus in stochastic dynamic networks with Byzantine nodes and adversarial edges}},
doi = {10.4230/LIPIcs.DISC.2024.21},
volume = {319},
year = {2024},
}
@inproceedings{17146,
abstract = {The Upper Bound Theorem for convex polytopes implies that the p-th Betti number of the Čech complex of any set of N points in ℝ^d and any radius satisfies β_p = O(N^m), with m = min{p+1, ⌈d/2⌉}. We construct sets in even and odd dimensions, which prove that this upper bound is asymptotically tight. For example, we describe a set of N = 2(n+1) points in ℝ³ and two radii such that the first Betti number of the Čech complex at one radius is (n+1)² - 1, and the second Betti number of the Čech complex at the other radius is n². In particular, there is an arrangement of n contruent balls in ℝ³ that enclose a quadratic number of voids, which answers a long-standing open question in computational geometry.},
author = {Edelsbrunner, Herbert and Pach, János},
booktitle = {40th International Symposium on Computational Geometry},
isbn = {9783959773164},
issn = {1868-8969},
location = {Athens, Greece},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Maximum Betti numbers of Čech complexes}},
doi = {10.4230/LIPIcs.SoCG.2024.53},
volume = {293},
year = {2024},
}
@inproceedings{17426,
abstract = {The robustness of neural networks against input perturbations with bounded
magnitude represents a serious concern in the deployment of deep learning
models in safety-critical systems. Recently, the scientific community has
focused on enhancing certifiable robustness guarantees by crafting 1-Lipschitz
neural networks that leverage Lipschitz bounded dense and convolutional layers.
Although different methods have been proposed in the literature to achieve this
goal, understanding the performance of such methods is not straightforward,
since different metrics can be relevant (e.g., training time, memory usage,
accuracy, certifiable robustness) for different applications. For this reason,
this work provides a thorough theoretical and empirical comparison between
methods by evaluating them in terms of memory usage, speed, and certifiable
robust accuracy. The paper also provides some guidelines and recommendations to
support the user in selecting the methods that work best depending on the
available resources. We provide code at
https://github.com/berndprach/1LipschitzLayersCompared.},
author = {Prach, Bernd and Brau, Fabio and Buttazzo, Giorgio and Lampert, Christoph},
booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition},
location = {Seattle, WA, United States},
pages = {24574--24583},
publisher = {Computer Vision Foundation},
title = {{1-Lipschitz layers compared: Memory, speed, and certifiable robustness}},
doi = {10.1109/CVPR52733.2024.02320},
year = {2024},
}
@unpublished{18874,
abstract = {Despite extensive research since the community learned about adversarial
examples 10 years ago, we still do not know how to train high-accuracy
classifiers that are guaranteed to be robust to small perturbations of their
inputs. Previous works often argued that this might be because no classifier
exists that is robust and accurate at the same time. However, in computer
vision this assumption does not match reality where humans are usually accurate
and robust on most tasks of interest. We offer an alternative explanation and
show that in certain settings robust generalization is only possible with
unrealistically large amounts of data. More precisely we find a setting where a
robust classifier exists, it is easy to learn an accurate classifier, yet it
requires an exponential amount of data to learn a robust classifier. Based on
this theoretical result, we explore how well robust classifiers generalize on
datasets such as CIFAR-10. We come to the conclusion that on this datasets, the
limitation of current robust models also lies in the generalization, and that
they require a lot of data to do well on the test set. We also show that the
problem is not in the expressiveness or generalization capabilities of current
architectures, and that there are low magnitude features in the data which are
useful for non-robust generalization but are not available for robust
classifiers.},
author = {Prach, Bernd and Lampert, Christoph},
booktitle = {arXiv},
title = {{Intriguing properties of robust classification}},
doi = {10.48550/arXiv.2412.04245},
year = {2024},
}