title: Epidemic Dreams: Dreaming about health during the COVID-19 pandemic

abstract:
  The continuity hypothesis of dreams suggests that the content of dreams is
continuous with the dreamer's waking experiences. Given the unprecedented
nature of the experiences during COVID-19, we studied the continuity hypothesis
in the context of the pandemic. We implemented a deep-learning algorithm that
can extract mentions of medical conditions from text and applied it to two
datasets collected during the pandemic: 2,888 dream reports (dreaming life
experiences), and 57M tweets mentioning the pandemic (waking life experiences).
The health expressions common to both sets were typical COVID-19 symptoms
(e.g., cough, fever, and anxiety), suggesting that dreams reflected people's
real-world experiences. The health expressions that distinguished the two sets
reflected differences in thought processes: expressions in waking life
reflected a linear and logical thought process and, as such, described
realistic symptoms or related disorders (e.g., nasal pain, SARS, H1N1); those
in dreaming life reflected a thought process closer to the visual and emotional
spheres and, as such, described either conditions unrelated to the virus (e.g.,
maggots, deformities, snakebites), or conditions of surreal nature (e.g., teeth
falling out, body crumbling into sand). Our results confirm that dream reports
represent an understudied yet valuable source of people's health experiences in
the real world.


title:
Elliptic generalization of integrable q-deformed Haldane-Shastry
  long-range spin chain

abstract:
  We describe integrable elliptic q-deformed anisotropic long-range spin chain.
The derivation is based on our recent construction for commuting anisotropic
elliptic spin Macdonald-Ruijsenaars operators. We prove that the Polychronakos
freezing trick can be applied to these operators, thus providing the commuting
set of Hamiltonians for long-range spin chain constructed by means of the
elliptic Baxter-Belavin ${\rm GL}_M$ $R$-matrix. Namely, we show that the
freezing trick is reduced to a set of elliptic function identities, which are
then proved. These identities can be treated as conditions for equilibrium
position in the underlying classical spinless Ruijsenaars-Schneider model.
Trigonometric degenerations are studied as well. For example, in the case of
${\rm GL}_2$ XXZ $R$-matrix the Uglov's q-deformation of the Haldane-Shastry
model is reproduced.

categories: math-ph cond-mat.str-el hep-th math.MP math.QA nlin.SI


title:
Information Extraction through AI techniques: The KIDs use case at
  CONSOB

abstract:
  In this paper we report on the initial activities carried out within a
collaboration between Consob and Sapienza University. We focus on Information
Extraction from documents describing financial instruments. We discuss how we
automate this task, via both rule-based and machine learning-based methods and
provide our first results.


title:
AntidoteRT: Run-time Detection and Correction of Poison Attacks on
  Neural Networks

abstract:
  We study backdoor poisoning attacks against image classification networks,
whereby an attacker inserts a trigger into a subset of the training data, in
such a way that at test time, this trigger causes the classifier to predict
some target class. %There are several techniques proposed in the literature
that aim to detect the attack but only a few also propose to defend against it,
and they typically involve retraining the network which is not always possible
in practice. We propose lightweight automated detection and correction
techniques against poisoning attacks, which are based on neuron patterns mined
from the network using a small set of clean and poisoned test samples with
known labels. The patterns built based on the mis-classified samples are used
for run-time detection of new poisoned inputs. For correction, we propose an
input correction technique that uses a differential analysis to identify the
trigger in the detected poisoned images, which is then reset to a neutral
color. Our detection and correction are performed at run-time and input level,
which is in contrast to most existing work that is focused on offline
model-level defenses. We demonstrate that our technique outperforms existing
defenses such as NeuralCleanse and STRIP on popular benchmarks such as MNIST,
CIFAR-10, and GTSRB against the popular BadNets attack and the more complex
DFST attack.


title: A Nonlinear Hierarchical Model for Longitudinal Data on Manifolds

abstract:
  Large longitudinal studies provide lots of valuable information, especially
in medical applications. A problem which must be taken care of in order to
utilize their full potential is that of correlation between intra-subject
measurements taken at different times. For data in Euclidean space this can be
done with hierarchical models, that is, models that consider intra-subject and
between-subject variability in two different stages. Nevertheless, data from
medical studies often takes values in nonlinear manifolds. Here, as a first
step, geodesic hierarchical models have been developed that generalize the
linear ansatz by assuming that time-induced intra-subject variations occur
along a generalized straight line in the manifold. However, this is often not
the case (e.g., periodic motion or processes with saturation). We propose a
hierarchical model for manifold-valued data that extends this to include trends
along higher-order curves, namely B\'ezier splines in the manifold. To this
end, we present a principled way of comparing shape trends in terms of a
functional-based Riemannian metric. Remarkably, this metric allows efficient,
yet simple computations by virtue of a variational time discretization
requiring only the solution of regression problems. We validate our model on
longitudinal data from the osteoarthritis initiative, including classification
of disease progression.


title: Make Some Noise: Reliable and Efficient Single-Step Adversarial Training

abstract:
  Recently, Wong et al. showed that adversarial training with single-step FGSM
leads to a characteristic failure mode named catastrophic overfitting (CO), in
which a model becomes suddenly vulnerable to multi-step attacks. They showed
that adding a random perturbation prior to FGSM (RS-FGSM) seemed to be
sufficient to prevent CO. However, Andriushchenko and Flammarion observed that
RS-FGSM still leads to CO for larger perturbations, and proposed an expensive
regularizer (GradAlign) to avoid CO. In this work, we methodically revisit the
role of noise and clipping in single-step adversarial training. Contrary to
previous intuitions, we find that using a stronger noise around the clean
sample combined with not clipping is highly effective in avoiding CO for large
perturbation radii. Based on these observations, we then propose Noise-FGSM
(N-FGSM) that, while providing the benefits of single-step adversarial
training, does not suffer from CO. Empirical analyses on a large suite of
experiments show that N-FGSM is able to match or surpass the performance of
previous single-step methods while achieving a 3$\times$ speed-up.


title: Transfer in Reinforcement Learning via Regret Bounds for Learning Agents

abstract:
  We present an approach for the quantification of the usefulness of transfer
in reinforcement learning via regret bounds for a multi-agent setting.
Considering a number of $\aleph$ agents operating in the same Markov decision
process, however possibly with different reward functions, we consider the
regret each agent suffers with respect to an optimal policy maximizing her
average reward. We show that when the agents share their observations the total
regret of all agents is smaller by a factor of $\sqrt{\aleph}$ compared to the
case when each agent has to rely on the information collected by herself. This
result demonstrates how considering the regret in multi-agent settings can
provide theoretical bounds on the benefit of sharing observations in transfer
learning.


title: Testing Lorentz Invariance with Neutrinos

abstract:
  The search for a theory that unifies general relativity and quantum theory
has focused attention on models of physics at the Planck scale. One possible
consequence of models such as string theory may be that Lorentz invariance is
not an exact symmetry of nature. We discuss here some possible experimental and
observational tests of Lorentz invariance involving neutrino physics and
astrophysics.


title: Atomic Objects on hyper-K\"ahler manifolds

abstract:
  We introduce and study the notion of atomic sheaves and complexes on
higher-dimensional hyper-K\"ahler manifolds and show that they share many of
the intriguing properties of simple sheaves on K3 surfaces. For example, we
prove formality of the dg algebra of derived endomorphisms for stable atomic
bundles. We further demonstrate the characteristics of atomic objects by
studying atomic Lagrangian submanifolds. In the appendix, we prove
non-existence results for spherical objects on hyper-K\"ahler manifolds.


title: Heterogeneous manifolds for curvature-aware graph embedding

abstract:
  Graph embeddings, wherein the nodes of the graph are represented by points in
a continuous space, are used in a broad range of Graph ML applications. The
quality of such embeddings crucially depends on whether the geometry of the
space matches that of the graph. Euclidean spaces are often a poor choice for
many types of real-world graphs, where hierarchical structure and a power-law
degree distribution are linked to negative curvature. In this regard, it has
recently been shown that hyperbolic spaces and more general manifolds, such as
products of constant-curvature spaces and matrix manifolds, are advantageous to
approximately match nodes pairwise distances. However, all these classes of
manifolds are homogeneous, implying that the curvature distribution is the same
at each point, making them unsuited to match the local curvature (and related
structural properties) of the graph. In this paper, we study graph embeddings
in a broader class of heterogeneous rotationally-symmetric manifolds. By adding
a single extra radial dimension to any given existing homogeneous model, we can
both account for heterogeneous curvature distributions on graphs and pairwise
distances. We evaluate our approach on reconstruction tasks on synthetic and
real datasets and show its potential in better preservation of high-order
structures and heterogeneous random graphs generation.


title: Smoothed Embeddings for Certified Few-Shot Learning

abstract:
  Randomized smoothing is considered to be the state-of-the-art provable
defense against adversarial perturbations. However, it heavily exploits the
fact that classifiers map input objects to class probabilities and do not focus
on the ones that learn a metric space in which classification is performed by
computing distances to embeddings of classes prototypes. In this work, we
extend randomized smoothing to few-shot learning models that map inputs to
normalized embeddings. We provide analysis of Lipschitz continuity of such
models and derive robustness certificate against $\ell_2$-bounded perturbations
that may be useful in few-shot learning scenarios. Our theoretical results are
confirmed by experiments on different datasets.


title:
A Bayesian Analysis of Physical Parameters for 783 Kepler Close
  Binaries: Extreme-Mass-Ratio Systems and a New Mass Ratio versus Period Lower
  Limit

abstract:
  Contact binary star systems represent the long-lived penultimate phase of
binary evolution. Population statistics of their physical parameters inform
understanding of binary evolutionary pathways and end products. We use light
curves and new optical spectroscopy to conduct a pilot study of ten
(near-)contact systems in the long-period (P>0.5 d) tail of close binaries in
the Kepler field. We couple PHOEBE light curve models with Markov-Chain Monte
Carlo analyses to compute Bayesian probabilities on inclinations, fillout
factors, mass ratios, third-light fractions, and component temperature ratios.
Mass ratios and third-light contributions measured from spectra agree well with
those inferred from the light curves. Most binaries in the pilot study have
extreme mass ratios q<0.32. At least eight are probable triples. A Bayesian
analysis of all 783 Kepler 0.15 d<P<2 d (near-)contact binaries forming an
unbiased sample of unprecedented size and photometric precision results in 178
probable contact systems, 114 probable detached systems, and 491 ambiguous
systems. We report best-fitting and 16th/50th/84th percentile parameters of
modeled systems. Contact systems are rare at periods P>0.5 d, as are systems
with mass ratios near unity (q>0.8). There exists an empirical mass ratio lower
limit $q_{min}$(P)~0.05-0.15 below which contact systems are absent, in
agreement with a new set of theoretical predictions we obtain by modeling the
evolution of contact systems under the constraints of mass and angular momentum
conservation. Pre-merger systems should be found at at long periods and near
this mass ratio lower limit, which rises from q=0.044 for P=0.74 d to q=0.15 at
P=2.0 d. These findings support a scenario whereby mass transfer drives systems
toward extreme $q$ and larger $P$ until the onset of the Darwin instability at
$q_{min}$ precipitates a merger.


title:
The interstellar medium in the environment of the supernova-less
  long-duration GRB 111005A

abstract:
  Long ($>2$ s) gamma ray bursts (GRBs) are associated with explosions of
massive stars, although in three instances, supernovae (SNe) have not been
detected, despite deep observations. With new HI line and archival optical
integral field spectroscopy data, we characterize the interstellar medium (ISM)
of the host galaxy of one of these events, GRB 111005A, in order to shed light
on the unclear nature of these peculiar objects. We found that the atomic gas,
radio continuum, and rotational patterns are in general very smooth throughout
the galaxy, which does not indicate a recent gas inflow or outflow. There is
also no gas concentration around the GRB position. The ISM in this galaxy
differs from that in hosts of other GRBs and SNe, which may suggest that the
progenitor of GRB 111005A was not an explosion of a very massive star (e.g. a
compact object merger). However, there are subtle irregularities of the GRB
111005A host (most at a $2\sigma$ level), which may point to a weak gas inflow
or interaction. Since in the SE part of the host there is 15% more atomic gas
and twice less molecular gas than in NW part, the molecular gas fraction is
low. In the SE part there is also a region with very high H$\alpha$ equivalent
width. There is more continuum 1.4 GHz emission to the SE and an S-shaped warp
in the UV. Finally, there is also a low-metallicity region 3.5" (1 kpc) from
the GRB position. Two galaxies within 300 kpc or a past merger can be
responsible for these irregularities.


title: On gluing semigroups in $\mathbb{N}^n$ and the consequences

abstract:
  A semigroup $\langle C\rangle$ in $\mathbb{N}^n$ is a gluing of $\langle
A\rangle$ and $\langle B\rangle$ if its finite set of generators $C$ splits
into two parts, $C=k_1A\sqcup k_2B$ with $k_1,k_2\geq 1$, and the defining
ideals of the corresponding semigroup rings satisfy that $I_C$ is generated by
$I_A+I_B$ and one extra element. Two semigroups $\langle A\rangle$ and $\langle
B\rangle$ can be glued if there exist positive integers $k_1,k_2$ such that,
for $C=k_1A\sqcup k_2B$, $\langle C\rangle$ is a gluing of $\langle A\rangle$
and $\langle B\rangle$. Although any two numerical semigroups, namely
semigroups in dimension $n=1$, can always be glued, it is no longer the case in
higher dimensions. In this paper, we give necessary and sufficient conditions
on $A$ and $B$ for the existence of a gluing of $\langle A\rangle$ and $\langle
B\rangle$, and give examples to illustrate why they are necessary. These
generalize and explain the previous known results on existence of gluing. We
also prove that the glued semigroup $\langle C\rangle$ inherits the properties
like Gorenstein or Cohen-Macaulay from the two parts $\langle A\rangle$ and
$\langle B\rangle$.


title: Quantum readout of imperfect classical data

abstract:
  The encoding of classical data in a physical support can be done up to some
level of accuracy due to errors and the imperfection of the writing process.
Moreover, some degradation of the storage data can happen over the time because
of physical or chemical instability of the system. Any read-out strategy should
take into account this natural degree of uncertainty and minimize its effect.
An example are optical digital memories, where the information is encoded in
two values of reflectance of a collection of cells. Quantum reading using
entanglement, has been shown to enhances the readout of an ideal optical
memory, where the two level are perfectly characterized. In this work, we will
analyse the case of imperfect construction of the memory and propose an
optimized quantum sensing protocol to maximize the readout accuracy in presence
of imprecise writing. The proposed strategy is feasible with current technology
and is relatively robust to detection and optical losses. Beside optical
memories, this work have implications for identification of pattern in
biological system, in spectrophotometry, and whenever the information can be
extracted from a transmission/reflection optical measurement.


title: GRB 210217A: A short or a long GRB?

abstract:
  Gamma-ray bursts are traditionally classified as short and long bursts based
on their $T_{\rm 90}$ value (the time interval during which an instrument
observes $5\%$ to $95\%$ of gamma-ray/hard X-ray fluence). However, $T_{\rm
90}$ is dependent on the detector sensitivity and the energy range in which the
instrument operates. As a result, different instruments provide different
values of $T_{\rm 90}$ for a burst. GRB 210217A is detected with different
duration by {\it Swift} and {\it Fermi}. It is classified as a long/soft GRB by
{\it Swift}-BAT with a $T_{\rm 90}$ value of 3.76 sec. On the other hand, the
sub-threshold detection by {\it Fermi}-GBM classified GRB 210217A as a
short/hard burst with a duration of 1.024 sec. We present the multi-wavelength
analysis of GRB 210217A (lying in the overlapping regime of long and short
GRBs) to identify its actual class using multi-wavelength data. We utilized the
$T_{\rm 90}$-hardness ratio, $T_{\rm 90}$-\Ep, and $T_{\rm 90}$-$t_{\rm mvts}$
distributions of the GRBs to find the probability of GRB 210217A being a short
GRB. Further, we estimated the photometric redshift of the burst by fitting the
joint XRT/UVOT SED and place the burst in the Amati plane. We found that GRB
210217A is an ambiguous burst showing properties of both short and long class
of GRBs.


title:
2D energy-momentum tensor distributions of nucleon in a large-$N_c$
  quark model from ultra-relativistic to non-relativistic limit

abstract:
  Form factors of the energy-momentum tensor (EMT) can be interpreted in
certain frames in terms of spatial distributions of energy, stress, linear and
angular momentum, based on 2D or 3D Fourier transforms. This interpretation is
in general subject to ``relativistic recoil corrections'', except when the
nucleon moves at the speed of light like e.g. in the infinite-momentum frame.
We show that it is possible to formulate a large-$N_c$ limit in which the
probabilistic interpretation of the nucleon EMT distributions holds also in
other frames. We use the bag model formulated in the large-$N_c$ limit as an
internally consistent quark model framework to visualize the information
content associated with the 2D EMT distributions. In order to provide more
intuition, we present results in the physical situation and in three different
limits: by considering a heavy-quark limit, a large system-size limit and a
constituent-quark limit. The visualizations of the distributions in these
extreme limits will help to interpret the results from experiments, lattice
QCD, and other models or effective theories.


title:
Ab initio approach for thermodynamic surface phases with full
  consideration of anharmonic effects -- the example of hydrogen at Si(100)

abstract:
  A reliable description of surfaces structures in a reactive environment is
crucial to understand materials functions. We present a first-principles theory
of replica-exchange grand-canonical-ensemble molecular dynamics (REGC-MD) and
apply it to evaluate phase equilibria of surfaces in reactive gas-phase
environment. We identify the different surface phases and locate phase
boundaries including triple and critical points. The approach is demonstrated
by addressing open questions for the Si(100) surface in contact with a hydrogen
atmosphere. In the range from 300 to 1 000 K, we find 25 distinct
thermodynamically stable surface phases, for which we also provide microscopic
descriptions. Most of the identified phases, including few order-disorder phase
transitions, have not yet been observed experimentally. The REGC-MD-derived
phase diagram shows significant, qualitative differences to the description by
the state-of-the-art "ab initio atomistic thermodynamics" approach.


title: Phases and phase-transitions in quasisymmetric configuration space

abstract:
  We explore the structure of the space of quasisymmetric configurations
identifying them by their magnetic axes, described as 3D closed curves. We
demonstrate that this topological perspective divides the space of all
configurations into well-separated quasisymmetric phases. Each phase is
characterized by the self-linking number (a topological invariant), defining
different symmetry configurations (quasi-axisymmetry or quasi-helical
symmetry). The phase-transition manifolds correspond to quasi-isodynamic
configurations. By considering some models for closed curves (most notably
torus unknots), general features associated with these phases are explored.
Some general criteria are also built and leveraged to provide a simple way to
describe existing quasisymmetric designs. This constitutes the first step in a
program to identify quasisymmetric configurations with a reduced set of
functions and parameters, to deepen understanding of configuration space, and
offer an alternative approach to stellarator optimization that begins with the
magnetic axis and builds outward.


title:
Mitigating cold start problems in drug-target affinity prediction with
  interaction knowledge transferring

abstract:
  Motivation: Predicting the drug-target interaction is crucial for drug
discovery as well as drug repurposing. Machine learning is commonly used in
drug-target affinity (DTA) problem. However, machine learning model faces the
cold-start problem where the model performance drops when predicting the
interaction of a novel drug or target. Previous works try to solve the cold
start problem by learning the drug or target representation using unsupervised
learning. While the drug or target representation can be learned in an
unsupervised manner, it still lacks the interaction information, which is
critical in drug-target interaction. Results: To incorporate the interaction
information into the drug and protein interaction, we proposed using transfer
learning from chemical-chemical interaction (CCI) and protein-protein
interaction (PPI) task to drug-target interaction task. The representation
learned by CCI and PPI tasks can be transferred smoothly to the DTA task due to
the similar nature of the tasks. The result on the drug-target affinity
datasets shows that our proposed method has advantages compared to other
pretraining methods in the DTA task.


title: Multi-armed Bandits for Link Configuration in Millimeter-wave Networks

abstract:
  Establishing and maintaining millimeter-wave (mmWave) links is challenging
due to the changing environment and the high sensibility of mmWave signal to
user mobility and channel conditions. MmWave link configuration problems often
involve a search for optimal system parameter under environmental
uncertainties, from a finite set of alternatives that are supported by the
system hardware and protocol. For example, beam sweeping aims at identifying
the optimal beam(s) for data transmission from a discrete codebook. Selecting
parameters such as the beam sweeping period and the beamwidth are crucial to
achieving high overall system throughput. In this article, we motivate the use
of the multi-armed bandit (MAB) framework to intelligently search out the
optimal configuration when establishing the mmWave links. MAB is a
reinforcement learning framework that guides a decision-maker to sequentially
select one action from a set of actions. As an example, we show that within the
MAB framework, the optimal beam sweeping period, beamwidth, and beam directions
could be dynamically learned with sample-computational-efficient bandit
algorithms. We conclude by highlighting some future research directions on
enhancing mmWave link configuration design with MAB.


title: VOS: Learning What You Don't Know by Virtual Outlier Synthesis

abstract:
  Out-of-distribution (OOD) detection has received much attention lately due to
its importance in the safe deployment of neural networks. One of the key
challenges is that models lack supervision signals from unknown data, and as a
result, can produce overconfident predictions on OOD data. Previous approaches
rely on real outlier datasets for model regularization, which can be costly and
sometimes infeasible to obtain in practice. In this paper, we present VOS, a
novel framework for OOD detection by adaptively synthesizing virtual outliers
that can meaningfully regularize the model's decision boundary during training.
Specifically, VOS samples virtual outliers from the low-likelihood region of
the class-conditional distribution estimated in the feature space. Alongside,
we introduce a novel unknown-aware training objective, which contrastively
shapes the uncertainty space between the ID data and synthesized outlier data.
VOS achieves state-of-the-art performance on both object detection and image
classification models, reducing the FPR95 by up to 7.87% compared to the
previous best method. Code is available at
https://github.com/deeplearning-wisc/vos.


title:
A Hybrid Compartmental Model with a Case Study of COVID-19 in Great
  Britain and Israel

abstract:
  Given the severe impact of COVID-19 on several societal levels, it is of
crucial importance to model the impact of restriction measures on the pandemic
evolution, so that governments are able to take informed decisions. Even though
there have been countless attempts to propose diverse models since the raise of
the outbreak, the increase in data availability and start of vaccination
campaigns calls for updated models and studies. Furthermore, most of the works
are focused on a very particular place or application and we strive to attain a
more general model, resorting to data from different countries. In particular,
we compare Great Britain and Israel, two highly different scenarios in terms of
vaccination plans and social structure. We build a network-based model, complex
enough to model different scenarios of government-mandated restrictions, but
generic enough to be applied to any population. To ease the computational load
we propose a decomposition strategy for our model.


title: The Ext-algebra for infinitesimal deformations

abstract:
  Let $f$ be a Hochschild $2$-cocycle and let $A_f$ be an infinitesimal
deformation of an associative finite dimensional algebra $A$ over an
algebraically closed field $\Bbbk$. We investigate the algebra structure of the
Ext-algebra of $A_f$ and, under some conditions on $f$, we describe it in terms
of the Ext-algebra of $A$. We achieve this description by getting an explicit
construction of minimal projective resolutions in $\mod A_f$.


title:
Muon lateral distribution function of extensive air showers: results of
  the Sydney University Giant Air-shower Recorder versus modern Monte-Carlo
  simulations

abstract:
  The Sydney University Giant Air-shower Recorder (SUGAR) measured the muon
component of extensive air showers with a unique array of muon detectors. The
SUGAR data allow us to reconstruct the empirical dependence of muon density on
the distance from the axis of the shower, the lateral distribution function
(LDF). We compare the shape of this function with the predictions of
hadronic-interaction models, QGSJET-II-04 and EPOS-LHC, in the energy range
10^17.6 - 10^18.6 eV. We find a difference between the observed data and the
simulation: the observed muon density falls faster with the increased core
distance than it is predicted in simulations. This observation may be important
for interpretation of the energy-dependent discrepancies in the simulated and
observed numbers of muons in air showers, known as the "muon excess".


title:
Reflected entropy in Galilean conformal field theories and flat
  holography

abstract:
  We obtain the reflected entropy for bipartite states in a class of
$(1+1)$-dimensional Galilean conformal field theories ($GCFT_{1+1}$) through a
replica technique. Furthermore we compare our results with the entanglement
wedge cross section (EWCS) obtained for the dual (2+1) dimensional
asymptotically flat geometries in the context of flat holography. We find that
our results are consistent with the duality between the reflected entropy and
the bulk EWCS for flat holographic scenarios.


title: Can late-time extensions solve the $H_0$ and $\sigma_8$ tensions?

abstract:
  We analyze the properties that any late-time modification of the $\Lambda$CDM
expansion history must have in order to consistently solve both the $H_0$ and
the $\sigma_8$ tensions. Taking a model-independent approach, we obtain a set
of necessary conditions that can be applied to generic late-time extensions.
Our results are fully analytical and merely based on the assumptions that the
deviations from the $\Lambda$CDM background remain small. For the concrete case
of a dark energy fluid with equation of state $w(z)$, we derive the following
general requirements: (i) Solving the $H_0$ tension demands $w(z)<-1$ at some
$z$ (ii) Solving both the $H_0$ and $\sigma_8$ tensions requires $w(z)$ to
cross the phantom divide. Finally, we also allow for small deviations on the
effective gravitational constant. In this case, our method is still able to
constrain the functional form of these deviations.


title: High pressure induced precipitation in Al7075 alloy

abstract:
  Precipitate-matrix interactions govern the mechanical behavior of precipitate
strengthened Al-based alloys. These alloys find a wide range of applications
ranging from aerospace to automobile and naval industries due to their low cost
and high strength to weight ratio. Structures made from Al-based alloys undergo
complex loading conditions such as high strain rate impact, which involves high
pressures. Here we use diamond anvil cells to study the behavior of Al-based
Al7075 alloy under quasi-hydrostatic and non-hydrostatic pressure up to ~53
GPa. In situ X-ray diffraction (XRD) and pre- and post-compression transmission
electron microscopy (TEM) imaging are used to analyze microstructural changes
and estimate high pressure strength. We find a bulk modulus of 75.2 +- 1.9 GPa
using quasi-hydrostatic pressure XRD measurements. XRD showed that
non-hydrostatic pressure leads to a significant increase in defect density and
peak broadening with pressure cycling. XRD mapping under non-hydrostatic
pressure revealed that the region with the highest local pressure had the
greatest increase in defect nucleation, whereas the region with the largest
local pressure gradient underwent texturing and had larger grains. TEM analysis
showed that pressure cycling led to the nucleation and growth of many
precipitates. The significant increase in defect and precipitate density leads
to an increase in strength for Al7075 alloy at high pressures.


title: Tweezer-programmable 2D quantum walks in a Hubbard-regime lattice

abstract:
  Quantum walks provide a framework for understanding and designing quantum
algorithms that is both intuitive and universal. To leverage the computational
power of these walks, it is important to be able to programmably modify the
graph a walker traverses while maintaining coherence. Here, we do this by
combining the fast, programmable control provided by optical tweezer arrays
with the scalable, homogeneous environment of an optical lattice. Using this
new combination of tools we study continuous-time quantum walks of single atoms
on a 2D square lattice, and perform proof-of-principle demonstrations of
spatial search using these walks. When scaled to more particles, the
capabilities demonstrated here can be extended to study a variety of problems
in quantum information science and quantum simulation, including the
deterministic assembly of ground and excited states in Hubbard models with
tunable interactions, and performing versions of spatial search in a larger
graph with increased connectivity, where search by quantum walk can be more
effective.


title: As Astrocientistas e o paradoxo da desigualdade de g\^enero na f\'isica

abstract:
  The first edition of the event As Astrocientistas: the Brazilian Meeting of
Women and Girls in Astrophysics, Cosmology, and Gravitation, happened in
February 2021. It gathered great names of Brazilian science to pay homage to
Brazilian female researchers and other female physicists with close ties to our
community. This paper presents our motivation to organize this event, the
challenges we faced, and exposes the learning experience we gained from doing
so. We will talk about the relevance of this event as we perceive it.


title:
The Diffuse Supernova Neutrino Background in the Standard and Double
  Collapse Models

abstract:
  The diffuse supernova neutrino background (DSNB) is a powerful future tool to
constrain core-collapse explosion mechanisms without observation of a nearby
event, and the corresponding signal has been calculated for a variety of
collapse models. For Supernova (SN) 1987A, a peculiar double neutrino burst was
detected, but models for the double collapse have never been studied in the
DSNB context. Here, we fill this gap and compare the DSNB signal expected in
the Standard Collapse (SC) and the Double Collapse (DC) models in various
future detectors, including Hyper-Kamiokande, JUNO, DUNE and the Large Baksan
Neutrino Telescope (LBNT). We calculate the spectra of diffuse neutrinos and
antineutrinos in the DC model and determine the rate of registered events as a
function of energy of the detected particle, taking into account detector
parameters. For each detector, we estimate the corresponding uncertainties and
the background and compare the signals expected for the SC and DC models. We
conclude that the combination of DUNE and LBNT data will have the highest
sensitivity to discriminate between the SC and DC models.


title: Anisotropic magnetized neutron star

abstract:
  As we know, the effect of strong magnetic field causes the anisotropy for the
magnetized compact objects. Therefore, in this paper, we have studied the
structure properties of anisotropic case of magnetized neutron star. We have
derived the equation of state (EoS) of neutron star matter for two forms of
magnetic fields, one uniform and one density dependent. We have solved the
generalized Tolman Oppenheimer Volkoff equations to examine the maximum mass
and corresponding radius, Schwarzschild radius, graviitational redshift,
Kretschmann scalar, and Buchdahl theorem for this system. It was shown that the
maximum mass and radius of neutron star are increasing functions of the
magnetic field. Also redshift, strength of gravity, and Kretschmann scalar
increase as the magnetic field increases. In addition, the dynamical stability
of anisotrop neutron star has been investigated, and finally a comparison with
the empirical results has been made.


title:
Deep Learning for Ultrasound Speed-of-Sound Reconstruction: Impacts of
  Training Data Diversity on Stability and Robustness

abstract:
  Ultrasound b-mode imaging is a qualitative approach and diagnostic quality
strongly depends on operators' training and experience. Quantitative approaches
can provide information about tissue properties; therefore, can be used for
identifying various tissue types, e.g., speed-of-sound in the tissue can be
used as a biomarker for tissue malignancy, especially in breast imaging. Recent
studies showed the possibility of speed-of-sound reconstruction using deep
neural networks that are fully trained on simulated data. However, because of
the ever present domain shift between simulated and measured data, the
stability and performance of these models in real setups are still under
debate. In this study, we investigated the impacts of training data diversity
on the robustness of these networks by using multiple kinds of geometrical and
natural simulated phantom structures. On the simulated data, we investigated
the performance of the networks on out-of-domain echogenicity, geometries, and
in the presence of noise. We further inspected the stability of employing such
tissue modeling in a real data acquisition setup. We demonstrated that training
the network with a joint set of datasets including both geometrical and natural
tissue models improves the stability of the predicted speed-of-sound values
both on simulated and measured data.


title:
Phenomenological Dark Energy model with hybrid dynamic Cosmological
  Constant

abstract:
  We investigate Dark Energy by associating it with vacuum energy or
Cosmological constant ${\Lambda}$ which is taken to be dynamic in nature. Our
approach is phenomenological and falls within the domain of variable-$\Lambda$
Cosmology. However, motivated by quantum theory of metastable vacuum decay, we
proposed a new phenomenological decay law of $\Lambda$(t) where $\Lambda$(t) is
a superposition of constant and variable components viz. $\Lambda$(t) =
$\Lambda_{C}$ + $\Lambda_{v}$ which is indicated by the word $"$hybrid
dynamic$"$ in the title. By taking a simplified two-fluid scenario with the
Universe consisting of Dark Energy and another major component, we found the
solutions for three particular phenomenological expressions and made a
parametrization of the model in terms of dilution parameter (the dilution
parameter has been defined in the text as the exponent of scale factor in the
expression of density of the other major component, representing the dilution
of the component with the expansion of Universe in the presence of dynamic Dark
Energy). For pressureless Dust and dynamic Dark Energy Universe, we found the
present-day matter density ($\Omega_{m0}$) and dilution parameter (u) to be
$\Omega_{m0}$ = 0.29 $\pm$ 0.03, u = 2.90 $\pm$ 0.54 at 1 $\sigma$ by analysing
580 supernova from Union 2.1 catalogue. The physical features of the model in
regard to scale factor evolution, deceleration parameter, cosmic age has also
been studied and parallels have been drawn with $\Lambda$CDM model. The status
of Cosmological problems in the model has also been checked which showed that
the model solves the Cosmological Constant Problem but the Coincidence problem
still exists in the model.


title: Deep Layer-wise Networks Have Closed-Form Weights

abstract:
  There is currently a debate within the neuroscience community over the
likelihood of the brain performing backpropagation (BP). To better mimic the
brain, training a network \textit{one layer at a time} with only a "single
forward pass" has been proposed as an alternative to bypass BP; we refer to
these networks as "layer-wise" networks. We continue the work on layer-wise
networks by answering two outstanding questions. First, $\textit{do they have a
closed-form solution?}$ Second, $\textit{how do we know when to stop adding
more layers?}$ This work proves that the Kernel Mean Embedding is the
closed-form weight that achieves the network global optimum while driving these
networks to converge towards a highly desirable kernel for classification; we
call it the $\textit{Neural Indicator Kernel}$.


title: A Flexible Clustering Pipeline for Mining Text Intentions

abstract:
  Mining the latent intentions from large volumes of natural language inputs is
a key step to help data analysts design and refine Intelligent Virtual
Assistants (IVAs) for customer service and sales support. We created a flexible
and scalable clustering pipeline within the Verint Intent Manager (VIM) that
integrates the fine-tuning of language models, a high performing k-NN library
and community detection techniques to help analysts quickly surface and
organize relevant user intentions from conversational texts. The fine-tuning
step is necessary because pre-trained language models cannot encode texts to
efficiently surface particular clustering structures when the target texts are
from an unseen domain or the clustering task is not topic detection. We
describe the pipeline and demonstrate its performance using BERT on three
real-world text mining tasks. As deployed in the VIM application, this
clustering pipeline produces high quality results, improving the performance of
data analysts and reducing the time it takes to surface intentions from
customer service data, thereby reducing the time it takes to build and deploy
IVAs in new domains.


title: Training Semantic Descriptors for Image-Based Localization

abstract:
  Vision based solutions for the localization of vehicles have become popular
recently. We employ an image retrieval based visual localization approach. The
database images are kept with GPS coordinates and the location of the retrieved
database image serves as an approximate position of the query image. We show
that localization can be performed via descriptors solely extracted from
semantically segmented images. It is reliable especially when the environment
is subjected to severe illumination and seasonal changes. Our experiments
reveal that the localization performance of a semantic descriptor can increase
up to the level of state-of-the-art RGB image based methods.


title: Exact Floquet solutions of quantum driven systems

abstract:
  How to accurately solve time-dependent Schr\"odinger equation is an
interesting and important problem. Here, we propose a novel method to obtain
the exact Floquet solutions of the Schr\"odinger equation for periodically
driven systems by using Floquet theorem and a time-dependent unitary
transformation. Using the method, we give out the exact Floquet solutions of
wave function for three interesting physical models -- linear potential model,
harmonic oscillator model, and the coupled harmonic oscillator model in the
presence of a periodic driving. In addition to the quasienergy, we also give
out the analytic expression of Berry phase for the harmonic oscillator model.
Moreover, the idea presented in this paper can be used in mathematics to solve
partial differential equations.


title:
Approximate Bisimulation Relations for Neural Networks and Application
  to Assured Neural Network Compression

abstract:
  In this paper, we propose a concept of approximate bisimulation relation for
feedforward neural networks. In the framework of approximate bisimulation
relation, a novel neural network merging method is developed to compute the
approximate bisimulation error between two neural networks based on
reachability analysis of neural networks. The developed method is able to
quantitatively measure the distance between the outputs of two neural networks
with the same inputs. Then, we apply the approximate bisimulation relation
results to perform neural networks model reduction and compute the compression
precision, i.e., assured neural networks compression. At last, using the
assured neural network compression, we accelerate the verification processes of
ACAS Xu neural networks to illustrate the effectiveness and advantages of our
proposed approximate bisimulation approach.


title:
Searching for Ultra-light Bosons and Constraining Black Hole Spin
  Distributions with Stellar Tidal Disruption Events

abstract:
  Stars that pass close to the supermassive black holes located in the center
of galaxies can be violently disrupted by tidal forces, leading to flares that
are observed as bright transient events in sky surveys. The rate for these
events to occur depends on the black hole spins, which in turn can be affected
by ultra-light bosons due to superradiance. We perform a detailed analysis of
these effects and show that searches for stellar tidal disruptions have a
significant potential to uncover the existence of ultra-light bosons. In
particular, we find that upcoming stellar tidal disruption rate measurements by
the Vera Rubin Observatory's Legacy Survey of Space and Time can be used to
either discover or rule out bosons with masses ranging from $10^{-20}$ to
$10^{-18}$ eV. Our analysis also indicates that these measurements may be used
to constrain a variety of supermassive black hole spin distributions and
determine if close-to maximal spins are preferred.


title: Sifting quantum black holes through the principle of least action

abstract:
  We tackle the question of whether regular black holes or other alternatives
to the Schwarzschild solution can arise from an action principle in quantum
gravity. Focusing on an asymptotic expansion of such solutions and inspecting
the corresponding field equations, we demonstrate that their realization within
a principle of stationary action would require either fine-tuning, or strong
infrared non-localities in the gravitational effective action. This points to
an incompatibility between large-distance locality and many of the proposed
alternatives to classical black holes.


title: Quadratic reciprocity from a family of adelic conformal field theories

abstract:
  We consider a deformation of the two-dimensional free scalar field theory by
raising the Laplacian to a positive real power. It turns out that the resulting
non-local generalized free action is invariant under two commuting actions of
the global conformal symmetry algebra, although it is no longer invariant under
the full Witt algebra. Furthermore, there is an adelic version of this family
of conformal field theories, parameterized by the choice of a number field,
together with a Hecke character. Tate's thesis gives the Green's functions of
these theories, and ensures that these Green's functions satisfy an adelic
product formula. In particular, the local $L$-factors contribute to the
prefactors of these Green's functions. Quadratic reciprocity turns out to be a
consequence of an adelic version of a holomorphic factorization property of
this family of theories on a quadratic extension of $\mathbb{Q}$. We explain
that at the Archimedean place, the desired holomorphic factorization follows
from the global conformal symmetry.


title: The Hasse Diagram of the Moduli Space of Instantons

abstract:
  Hasse diagrams (or phase diagrams) for moduli spaces of supersymmetric field
theories have been intensively studied in recent years, and many tools to
compute them have been developed. The moduli space of instantons, despite being
well studied, has proven difficult to deal with. In this note we explore the
Hasse diagram of this moduli space from several perspectives -- using the
partial Higgs mechanism, using brane systems and using quiver subtraction --
having to refine previously developed techniques. In particular we introduce
the new concept of decorated quiver, which allows to deal with a large class of
unitary quivers, including those with adjoint matter.


title:
The ALMA REBELS Survey: Efficient Ly$\alpha$ Transmission of UV-Bright
  z$\simeq$7 Galaxies from Large Velocity Offsets and Broad Line Widths

abstract:
  Recent work has shown that UV-luminous reionization-era galaxies often
exhibit strong Lyman-alpha emission despite being situated at redshifts where
the IGM is thought to be substantially neutral. It has been argued that this
enhanced Ly$\alpha$ transmission reflects the presence of massive galaxies in
overdense regions which power large ionized bubbles. An alternative explanation
is that massive galaxies shift more of their Ly$\alpha$ profile to large
velocities (relative to the systemic redshift) where the IGM damping wing
absorption is reduced. Such a mass-dependent trend is seen at lower redshifts,
but whether one exists at $z\sim7$ remains unclear owing to the small number of
existing systemic redshift measurements in the reionization era. This is now
changing with the emergence of [CII]-based redshifts from ALMA. Here we report
MMT/Binospec Ly$\alpha$ spectroscopy of eight UV-bright
($\mathrm{M_{UV}}^{}\sim-22$) galaxies at $z\simeq7$ selected from the ALMA
REBELS survey. We detect Ly$\alpha$ in 4 of 8 galaxies and use the [CII]
systemic redshifts to investigate the Ly$\alpha$ velocity profiles. The
Ly$\alpha$ lines are significantly redshifted from systemic (average velocity
offset=223 km/s) and broad (FWHM$\approx$300$-$650 km/s), with two sources
showing emission extending to $\approx$750 km/s. We find that the broadest
Ly$\alpha$ profiles are associated with the largest [CII] line widths,
suggesting a potential link between the Ly$\alpha$ FWHM and the dynamical mass.
Since Ly$\alpha$ photons at high velocities transmit efficiently through the
$z=7$ IGM, our data suggest that velocity profiles play a significant role in
boosting the Ly$\alpha$ visibility of the most UV-luminous reionization-era
galaxies.


title: Tracing stars in Milky Way satellites with A-SLOTH

abstract:
  We study the stellar mass-to-halo mass relation at $z=0$ in 30 Milky Way-like
systems down to the ultra-faint ($M_* < 10^5 M_\odot$) regime using the
semi-analytic model A-SLOTH. A new model allows us to follow star formation and
the stochastic stellar feedback from individually sampled Pop II stars. Our
fiducial model produces consistent results with the stellar mass-to-halo mass
relation derived from abundance matching and the observed cumulative stellar
mass function above the observational completeness. We find a plateau in the
stellar mass-to-halo mass relation in the ultra-faint regime. The stellar mass
of this plateau tells us how many stars formed before supernovae occur and
regulate further star formation, which is determined by the Pop~II star
formation efficiency. We also find that the number of luminous satellites
increases rapidly as $M_*$ decreases until $M_* \approx 10^4 M_\odot$. Finally,
we find that the relative streaming velocity between baryons and dark matter at
high redshift is important in determining the number of ultra-faint dwarf
galaxies at $z=0$. The new model in A-SLOTH provides a framework to study the
stellar properties and the formation history of metal-poor stars in Milky Way
and its satellites.


title:
The High Fraction of Thin Disk Galaxies Continues to Challenge
  {\Lambda}CDM Cosmology

abstract:
  Any viable cosmological framework has to match the observed proportion of
early- and late-type galaxies. In this contribution, we focus on the
distribution of galaxy morphological types in the standard model of cosmology
(Lambda cold dark matter, $\Lambda$CDM). Using the latest state-of-the-art
cosmological $\Lambda$CDM simulations known as Illustris, IllustrisTNG, and
EAGLE, we calculate the intrinsic and sky-projected aspect ratio distribution
of the stars in subhalos with stellar mass $M_* > 10^{10}\,M_\odot$ at redshift
$z=0$. There is a significant deficit of intrinsically thin disk galaxies,
which however comprise most of the locally observed galaxy population.
Consequently, the sky-projected aspect ratio distribution produced by these
$\Lambda$CDM simulations disagrees with the Galaxy And Mass Assembly (GAMA)
survey and Sloan Digital Sky Survey at $\geq 12.52\sigma$ (TNG50-1) and $\geq
14.82\sigma$ (EAGLE50) confidence. The deficit of intrinsically thin galaxies
could be due to a much less hierarchical merger-driven build-up of observed
galaxies than is given by the $\Lambda$CDM framework. It might also arise from
the implemented sub-grid models, or from the limited resolution of the
above-mentioned hydrodynamical simulations. We estimate that an $8^5$ times
better mass resolution realization than TNG50-1 would reduce the tension with
GAMA to the $5.58\sigma$ level. Finally, we show that galaxies with fewer major
mergers have a somewhat thinner aspect ratio distribution. Given also the high
expected frequency of minor mergers in $\Lambda$CDM, the problem may be due to
minor mergers. In this case, the angular momentum problem could be alleviated
in Milgromian dynamics (MOND) because of a reduced merger frequency arising
from the absence of dynamical friction between extended dark matter halos.


title:
Positivity bounds from multiple vacua and their cosmological
  consequences

abstract:
  Positivity bounds - constraints on any low-energy effective field theory
imposed by the fundamental axioms of unitarity, causality and locality in the
UV - have recently been used to constrain various effective field theories
relevant for cosmology. However, to date most of these bounds have assumed that
there is a single Lorentz-invariant vacuum in which all fields have zero
expectation value and in many cosmologically relevant models this is not the
case. We explore ways to overcome this limitation by investigating a simple
example model, the covariant Galileon, which possesses a one-parameter family
of Lorentz-invariant vacua as well as multiple boost-breaking vacua. Each of
these vacua has a corresponding set of positivity bounds, and we show how a
particular (beyond-the-forward-limit) bound can be used to map out the
parameter space according to which vacua may persist in the UV theory, finding
that in general there are regions in which none, one or many of the effective
field theory vacua can be consistent with unitarity, causality and locality in
the UV. Finally, we discuss the interplay between this map and cosmological
observations. We find that the observationally favoured region of parameter
space is incompatible with a large class of vacua, and conversely that
particular boost-breaking vacua would imply positivity bounds that rule out
otherwise observationally favoured cosmologies. We also identify a specific
boost-breaking vacuum which is `closest' to the cosmological background, and
show that the particular positivity bound we consider reduces the otherwise
cosmologically favoured region of Galileon parameter space by up to $70 \%$,
ruling out the vast majority of cosmologies with a positive coefficient for the
cubic Galileon in the process.


title: 3d Mirror Symmetry and the $\beta\gamma$ VOA

abstract:
  We study the simplest example of mirror symmetry for 3d $\mathcal N=4$ SUSY
gauge theories: the A-twist of a free hypermultiplet and the B-twist of SQED.
We particularly focus on the category of line operators in each theory. Using
the work of Costello-Gaiotto, we define these categories as appropriate
categories of modules for the boundary vertex operator algebras present in each
theory. For the A-twist of a free hyper, this will be a certain category of
modules for the $\beta\gamma$ VOA, properly containing the category previously
studied by Allen-Wood. Applying the work of Creutzig-Kanade-McRae and
Creutzig-McRae-Yang, we show that the category of line operators on the A side
possesses the structure of a braided tensor category, extending the result of
Allen-Wood. In addition, we prove that there is a braided tensor equivalence
between the categories of line operators on the A side and B side, completing a
non-trivial check of the 3d mirror symmetry conjecture. We derive explicit
fusion rules as a consequence of this equivalence and obtain interesting
relations with associated quantum group representations.


title:
Pair-density-wave superconductor from doping Haldane chain and
  rung-singlet ladder

abstract:
  We report the numerical discovery of a pair-density-wave (PDW) superconductor
from doping either (i) a spin-one Haldane chain or (ii) a two-leg ladder in the
rung singlet phase in which the doped charges occupy a single leg. We model
these systems using a generalized Kondo model. The itinerant electrons are
correlated and described by the $t-J$ model, and are further coupled to a spin
$1/2$ Heisenberg model through the Kondo coupling $J_K$. When the density of
electrons $x$ is one, the Mott insulator is in a Haldane phase or in a rung
singlet phase depending on whether $J_K$ is negative or positive. Upon doping,
a pair-density-wave with $\mathbf Q=\pi$ can emerge for both signs of $J_K$. In
the $J_K \rightarrow -\infty$ limit, the model reduces to the recently proposed
type II t-J model and we observes a continuous transition between the PDW
superconductor and an unconventional Luttinger liquid phase with doping. We
also identify a composite order parameter for the superconductor, which can be
understood as a Cooper pair formed by two nearby fermionic spin-polarons. Our
model and the predicted PDW phase can be experimentally realized by doping S=1
chains formed by Ni$^{2+}$ in a solid state system or a two-leg ladder of
fermionic cold atoms with a potential bias between legs, which preferentially
dopes carriers into a single leg.


title: Simple Rules for Evanescent Operators in One-Loop Basis Transformations

abstract:
  Basis transformations often involve Fierz and other relations which are only
valid in $D=4$ dimensions. In general $D$ space-time dimensions however,
evanescent operators have to be introduced, in order to preserve such
identities. Such evanescent operators contribute to one-loop basis
transformations as well as to two-loop renormalization group running. We
present a simple procedure on how to systematically change basis at the
one-loop level by obtaining shifts due to evanescent operators. As an example
we apply this method to derive the one-loop basis transformation from the BMU
basis useful for NLO QCD calculations, to the JMS basis used in the matching to
the SMEFT.


title: Updated void catalogs of the SDSS DR7 main sample

abstract:
  We produce several public void catalogs using a volume-limited subsample of
the Sloan Digital Sky Survey Data Release 7 (SDSS DR7). Using new
implementations of three different void-finding algorithms, VoidFinder and two
ZOBOV-based algorithms (VIDE and REVOLVER), we identify 1159, 534, and 518
cosmic voids with radii >10 Mpc/h, respectively, out to a redshift of z =
0.114. We compute effective radii and centers for all voids and find none with
an effective radius >54 Mpc/h. The median void effective radius is 15-17 Mpc/h
for all three algorithms. We extract and discuss several properties of the void
populations, including radial density profiles, the volume fraction of the
catalog contained within voids, and the fraction of galaxies contained within
voids. Using 64 mock galaxy catalogs created from the Horizon Run 4 N-body
simulation, we compare simulated and observed void properties and find good
agreement between the SDSS~DR7 and mock catalog results.


title:
The REBELS ALMA Survey: cosmic dust temperature evolution out to z
  $\sim$ 7

abstract:
  ALMA observations have revealed the presence of dust in the first generations
of galaxies in the Universe. However, the dust temperature $T_d$ remains mostly
unconstrained due to the few available FIR continuum data at redshift $z>5$.
This introduces large uncertainties in several properties of high-$z$ galaxies,
namely their dust masses, infrared luminosities, and obscured fraction of star
formation. Using a new method based on simultaneous [CII] 158$\mu$m line and
underlying dust continuum measurements, we derive $T_ d$ in the continuum and
[CII] detected $z\approx 7$ galaxies in the ALMA Large Project REBELS sample.
We find $39\ \mathrm{K} < T_d < 58\ \mathrm{K}$, and dust masses in the narrow
range $M_d = (0.9-3.6)\times 10^7 M_{\odot}$. These results allow us to extend
for the first time the reported $T_d(z)$ relation into the Epoch of
Reionization. We produce a new physical model that explains the increasing $T_
d(z)$ trend with the decrease of gas depletion time,
$t_{dep}=M_g/\mathrm{SFR}$, induced by the higher cosmological accretion rate
at early times; this hypothesis yields $T_d \propto (1+z)^{0.4}$. The model
also explains the observed $T_d$ scatter at a fixed redshift. We find that dust
is warmer in obscured sources, as a larger obscuration results in more
efficient dust heating. For UV-transparent (obscured) galaxies, $T_d$ only
depends on the gas column density (metallicity), $T_d \propto N_H^{1/6}$ ($T_d
\propto Z^{-1/6}$). REBELS galaxies are on average relatively transparent, with
effective gas column densities around $N_H \simeq (0.03-1)\times 10^{21}
\mathrm{cm}^{-2}$. We predict that other high-$z$ galaxies (e.g. MACS0416-Y1,
A2744-YD4), with estimated $T_d \gg 60$ K, are significantly obscured,
low-metallicity systems. In fact $T_d$ is higher in metal-poor systems due to
their smaller dust content, which for fixed $L_{ IR}$ results in warmer
temperatures.


title: Gegenbauer's Twin

abstract:
  In Twin Higgs models the dominant source of fine-tuning is the cancellation
of order $v^2/f^2$ required to obtain a Standard Model-like Higgs, where $v$
and $f$ are the electroweak and new physics scales, respectively. Recently
proposed Gegenbauer Goldstone models naturally realise $v^2/f^2 \ll 1$ and
hence remove this source of fine-tuning. By combining the two into
`Gegenbauer's Twin', we obtain a symmetry-based model for Higgs sector
naturalness consistent with current collider measurements without fine-tuning
of parameters. Single-Higgs coupling deviations of a few percent and trilinear
self-coupling deviations of order one are irreducible in the natural parameter
space. Thus, notably, the fingerprints of Gegenbauer's Twin could emerge first
through di-Higgs measurements at the High-Luminosity LHC.


title: Data-Driven Behaviour Estimation in Parametric Games

abstract:
  A central question in multi-agent strategic games deals with learning the
underlying utilities driving the agents' behaviour. Motivated by the increasing
availability of large data-sets, we develop an unifying data-driven technique
to estimate agents' utility functions from their observed behaviour,
irrespective of whether the observations correspond to (Nash) equilibrium
configurations or to action profile trajectories. Under standard assumptions on
the parametrization of the utilities, the proposed inference method is
computationally efficient and finds all the parameters that rationalize the
observed behaviour best. We numerically validate our theoretical findings on
the market share estimation problem under advertising competition, using
historical data from the Coca-Cola Company and Pepsi Inc. duopoly.


title:
Quasinormal resonances of rapidly-spinning Kerr black holes and the
  universal relaxation bound

abstract:
  The universal relaxation bound suggests that the relaxation times of
perturbed thermodynamical systems is bounded from below by the simple
time-times-temperature (TTT) quantum relation $\tau\times T\geq
{{\hbar}\over{\pi}}$. It is known that some perturbation modes of near-extremal
Kerr black holes in the regime $MT_{\text{BH}}/\hbar\ll m^{-2}$ are
characterized by normalized relaxation times $\pi\tau\times
T_{\text{BH}}/\hbar$ which, in the approach to the limit
$MT_{\text{BH}}/\hbar\to0$, make infinitely many oscillations with a tiny
constant amplitude around $1$ and therefore cannot be used directly to verify
the validity of the TTT bound in the entire parameter space of the black-hole
spacetime (Here $\{T_{\text{BH}},M\}$ are respectively the Bekenstein-Hawking
temperature and the mass of the black hole, and $m$ is the azimuthal harmonic
index of the linearized perturbation mode). In the present compact paper we
explicitly prove that all rapidly-spinning Kerr black holes respect the TTT
relaxation bound. In particular, using analytical techniques, it is proved that
all black-hole perturbation modes in the complementary regime $m^{-1}\ll
MT_{\text{BH}}/\hbar\ll1$ are characterized by relaxation times with the simple
dimensionless property $\pi\tau\times T_{\text{BH}}/\hbar\geq1$.


title: Interaction Enabled Fractonic Higher-Order Topological Phases

abstract:
  In this work, we present a collection of three-dimensional higher-order
symmetry protected topological phases (HOSPTs) with gapless hinge modes that
exist only in strongly interacting systems subject to subsystem symmetry
constraints. We use a coupled wire construction to generate three families of
microscopic lattice models: insulators with helical hinge modes,
superconductors with chiral Majorana hinge modes, and fractionalized insulators
with helical hinge modes that carry fractional charge. In particular, these
HOSPTs do not require spatial symmetry protection, but are instead protected by
subsystem symmetries, and support "fractonic" quasiparticle excitations that
move within only a low-dimensional sub-manifold of the system. We analyze the
anomaly structure for the boundary theory and the entanglement Hamiltonian, and
show that the side surfaces of these HOSPTs, despite being partially gapped,
exhibit symmetry anomalies, and can only be realized as the boundary of
three-dimensional HOSPT phases.


title: Universal Scaling Laws for Solar and Stellar Atmospheric Heating

abstract:
  The Sun and sun-like stars commonly host the multi-million-Kelvin coronae and
the 10,000-Kelvin chromospheres. These extremely hot gases generate X-ray and
Extreme Ultraviolet emissions that may impact the erosion and chemistry of
(exo)planetary atmospheres, influencing the climate and conditions of
habitability. However, the mechanism of coronal and chromospheric heating is
still poorly understood. While the magnetic field most probably plays a key
role in driving and transporting energy from the stellar surface upwards, it is
not clear if the atmospheric heating mechanisms of the Sun and active sun-like
stars can be described in a unified manner. To this end, we report on a
systematic survey of the responses of solar and stellar atmospheres to surface
magnetic flux over a wide range of temperatures. By analyzing 10 years of
multi-wavelength synoptic observations of the Sun, we reveal that the
irradiance and magnetic flux show power-law relations with an exponent
decreasing from above- to sub-unity as the temperature decreases from the
corona to the chromosphere. Moreover, this trend indicating the efficiency of
atmospheric heating can be extended to sun-like stars. We also discover that
the power-law exponent has a solar cycle dependence, where it becomes smallest
at activity maximum, probably due to the saturation of atmospheric heating. Our
study provides observational evidence that the mechanism of atmospheric heating
is universal among the Sun and sun-like stars, regardless of age or activity.


title: More Optimal Simulation of Universal Quantum Computers

abstract:
  Validating whether a quantum device confers a computational advantage often
requires classical simulation of its outcomes. The worst-case sampling cost of
$L_1$-norm based simulation has plateaued at $\le(2+\sqrt{2})\xi_t \delta^{-1}$
in the limit that $t \rightarrow \infty$, where $\delta$ is the additive error
and $\xi_t$ is the stabilizer extent of a $t$-qubit magic state. We reduce this
prefactor 68-fold by a leading-order reduction in $t$ through correlated
sampling. The result exceeds even the average-case of the prior
state-of-the-art and current simulators accurate to multiplicative error.
Numerical demonstrations support our proofs. The technique can be applied
broadly to reduce the cost of $L_1$ minimization.


title:
Identification and spectroscopic characterization of 128 new Herbig
  stars

abstract:
  We present optical spectroscopy observations of 145 high-mass pre-main
sequence candidates from the catalogue of Vioque et al. (2020). From these, we
provide evidence for the Herbig nature of 128 sources. This increases the
number of known objects of the class by $\sim50\%$. We determine the stellar
parameters of these sources using the spectra and Gaia EDR3 data. The new
sources are well distributed in mass and age, with 23 sources between $4$-$8$
M$_{\odot}$ and 32 sources above $8$ M$_{\odot}$. Accretion rates are inferred
from H$\alpha$ and H$\beta$ luminosities for 104 of the new Herbigs. These
accretion rates, combined with previous similar estimates, allow us to analyze
the accretion properties of Herbig stars using the largest sample ever
considered. We provide further support to the existence of a break in accretion
properties at $\sim3$-$4$ M$_{\odot}$, which was already reported for the
previously known Herbig stars. We re-estimate the potential break in accretion
properties to be at $3.87^{+0.38}_{-0.96}$ M$_{\odot}$. As observed for the
previously known Herbig stars, the sample of new Herbig stars independently
suggests intense inner-disk photoevaporation for sources with masses above
$\sim7$ M$_{\odot}$. These observations provide robust observational support to
the accuracy of the Vioque et al. (2020) catalogue of Herbig candidates.


title:
Extended radio emission in the galaxy cluster MS 0735.6+7421 detected
  with the Karl G. Jansky Very Large Array

abstract:
  MS 0735.6+7421 ($z = 0.216$) is a massive cool core galaxy cluster hosting
one of the most powerful active galactic nuclei (AGN) outbursts known. The
radio jets of the AGN have carved out an unusually large pair of X-ray
cavities, each reaching a diameter of $200$ kpc. This makes MS 0735.6+7421 a
unique case to investigate active galactic nuclei feedback processes, as well
as other cluster astrophysics at radio wavelengths. We present new
low-radio-frequency observations of MS 0735.6+7421 taken with the Karl G.
Jansky Very Large Array (VLA): 5 hours of P-band ($224-480$ MHz) and 5 hours of
L-band ($1-2$ GHz) observations, both in C configuration. Our VLA P-band
($224-480$ MHz) observations reveal the presence of a new diffuse radio
component reaching a scale of $\sim$ $900$ kpc in the direction of the jets and
of $\sim$ $500$ kpc in the direction perpendicular to the jets. This component
is centered on the cluster core and has a radio power scaled at $1.4$ GHz of
$P_{1.4\text{ GHz}} = (4\pm2)\times 10^{24}$ WHz$^{-1}$. Its properties are
consistent with those expected from a radio mini-halo as seen in other massive
cool core clusters, although it may also be associated with radio plasma that
has diffused out of the X-ray cavities. Observations at higher spatial
resolution are needed to fully characterize the properties and nature of this
component. We also suggest that if radio mini-halos originate from jetted
activity, we may be witnessing the early stages of this process.


title:
XGA: A module for the large-scale scientific exploitation of archival
  X-ray astronomy data

abstract:
  The XMM Cluster Survey (XCS) have developed a new Python module, X-ray:
Generate and Analyse (XGA) to provide interactive and automated analyses of
X-ray emitting sources observed by the XMM-Newton space telescope. XGA only
requires that a set of cleaned, processed, event lists has been created, and
(optionally) that a source detector has generated region lists for the
observations. XGA is centered around the concept of making all available data
easily accessible and analysable. The user provides information (e.g. RA, Dec,
redshift) on the source they wish to investigate, and XGA locates relevant
observations and generates required data products. This allows the user to
quickly and easily complete common analyses using all relevant observations,
thus being left free to focus on extracting the maximum scientific gain. XGA is
centered around source and sample classes, which represent different types of
X-ray emitting astrophysical objects and have different properties and methods
relevant to that type of object. XGA also contains product classes, which
provide interfaces to X-ray data products or information (such as radial
profiles) that have been derived from them, with built-in methods for fitting,
analysis, and visualisation. XGA can fit models to spectra (both global and
annular) with XSPEC, measuring spectral properties such as temperature, photon
index, and luminosity. XGA can also measure radial profiles of density and
temperature for galaxy clusters, allowing the measurement of gas and total mass
profiles of galaxy clusters. In the future, we will add support for X-ray
telescopes other than XMM (e.g. Chandra, eROSITA), as well as the ability to
perform multi-mission joint analyses. With the advent of new X-ray
observatories such as eROSITA, XRISM, ATHENA, and Lynx, it is the perfect time
for a new, open-source, software package that is open for anyone to use and
scrutinise.

categories: astro-ph.IM astro-ph.CO astro-ph.GA astro-ph.HE


title:
Uncovering a chirally suppressed mechanism of $0\nu\beta\beta$ decay
  with LHC searches

abstract:
  $\Delta L =2$ lepton number violation (LNV) at the TeV scale could provide an
alternative interpretation of positive signal(s) in future neutrinoless double
beta $(0\nu\beta\beta)$ decay experiments. An interesting class of models from
this point of view are those that at low energies give rise to dimension-9
vector operators and a dimension-7 operator, both of whose
$0\nu\beta\beta$-decay rates are "chirally suppressed". We study and compare
for the first time the sensitivities of $0\nu\beta\beta$-decay experiments and
LHC searches to a simplified model in this class of TeV-scale LNV. Due to the
chiral suppression of the vector operators, $0\nu\beta\beta$-decay searches are
found to be less constraining than LHC searches. For the chirally suppressed
dimension-7 operator generated by TeV-scale mediators, in contrast,
$0\nu\beta\beta$-decay searches place strong constraints on the size of the new
Yukawa coupling. Signals of this model at the LHC and $0\nu\beta\beta$-decay
experiments are entirely uncorrelated with the observed neutrinos masses, as
these new sources of LNV give negligible contributions to the latter. We find
the prospects for the high-luminosity LHC and ton-scale $0\nu\beta\beta$-decay
experiments to uncover the chirally-suppressed mechanism with TeV-scale LNV to
be promising. We also comment on the sensitivity of the $0\nu\beta\beta$-decay
lifetime to certain unknown low-energy constants that in the case of
dimension-9 {\it scalar} operators are expected to be large due to
non-perturbative renormalization.


title:
Berry Phases of Vison Transport in $\mathbb{Z}_2$ Topological Ordered
  States from Exact Fermion-Flux Lattice Dualities

abstract:
  We develop an exact map of all states and operators from 2D lattices of
spins-$1/2$ into lattices of fermions and bosons with mutual semionic
statistical interaction that goes beyond previous dualities of $\mathbb{Z}_2$
lattice gauge theories because it does not rely on imposing local conservation
laws and captures the motion of "charges" and "fluxes" on equal footing. This
map allows to explicitly compute the Berry phases for the transport of fluxes
in symmetry enriched topologically ordered states that can be either chiral,
non-chiral, abelian or non-abelian, and whose numerical complexity reduces to
diagonalizing free-fermion Hamiltonians. Among other results, we establish
numerically the conditions under which the Majorana-carrying flux excitation in
Ising-Topologically-Ordered states enriched by translations acquires $0$ or
$\pi$ phase when moving around a single plaquette.


title:
On the Derivation of Chiral Symmetry Breaking in QCD-like Theories and
  S-confining Theories

abstract:
  Recent works argue that the pattern of chiral symmetry breaking in QCD-like
theories can be derived from supersymmetric (SUSY) QCD with perturbation of
anomaly-mediated SUSY breaking (AMSB). Nevertheless, despite the fact that AMSB
needs to be a small (but still exact) perturbation, there are two other major
problems remaining unsolved: first, in order to derive the chiral symmetry
breaking pattern, one needs to minimize the potential along a certain specific
direction, identifying this direction fully as an outcome is nontrivial given
the moduli space of degenerate vacua in the SUSY limit; second, when SUSY is
broken, non-holomorphic states might emerge and be relevant for determining the
vacuum structure. In this work, we focus on SUSY QCD with $N_f\leq N_c+1$ and
perturb the theories using AMSB. Without minimizing the potential along a
certain specific direction in the moduli space, we successfully derive the
expected chiral symmetry breaking pattern when $N_f<N_c$. However, when
$N_f=N_c$ and $N_f=N_c+1$, we show that tree-level AMSB would induce runaway
directions, along which baryon number is spontaneously broken, and the vacua
with broken baryon number can be deeper while the field values are not far from
the origin. This implies that phase transitions and/or non-holomorphic physics
are necessary. Moreover, we perform explicit consistency checks on ultraviolet
insensitivity for different $N_f$ by adding the holomorphic mass term for the
last flavor, we find that the jump of AMSB potential indeed matches the
contribution from the holomorphic mass term. We also show in general that, when
tree-level AMSB is not vanishing, the origin of the moduli space in s-confining
theories does not persist as a minimum.


title:
A transiting, temperate mini-Neptune orbiting the M dwarf TOI-1759
  unveiled by TESS

abstract:
  We report the discovery and characterization of TOI-1759~b, a temperate (400
K) sub-Neptune-sized exoplanet orbiting the M~dwarf TOI-1759 (TIC 408636441).
TOI-1759 b was observed by TESS to transit on sectors 16, 17 and 24, with only
one transit observed per sector, creating an ambiguity on the orbital period of
the planet candidate. Ground-based photometric observations, combined with
radial-velocity measurements obtained with the CARMENES spectrograph, confirm
an actual period of $18.85019 \pm 0.00014$ d. A joint analysis of all available
photometry and radial velocities reveal a radius of $3.17 \pm 0.10\,R_\oplus$
and a mass of $10.8 \pm 1.5\,M_\oplus$. Combining this with the stellar
properties derived for TOI-1759 ($R_\star = 0.597 \pm 0.015\,R_\odot$; $M_\star
= 0.606 \pm 0.020\,M_\odot$; $T_{\textrm{eff}} = 4065 \pm 51$ K), we compute a
transmission spectroscopic metric (TSM) value of over 80 for the planet, making
it a good target for transmission spectroscopy studies. TOI-1759 b is among the
top five temperate, small exoplanets ($T_\textrm{eq} < 500$ K, $R_p < 4
\,R_\oplus$) with the highest TSM discovered to date. Two additional signals
with periods of 80 d and $>$ 200 d seem to be present in our radial velocities.
While our data suggest both could arise from stellar activity, the later
signal's source and periodicity are hard to pinpoint given the $\sim 200$ d
baseline of our radial-velocity campaign with CARMENES. Longer baseline
radial-velocity campaigns should be performed in order to unveil the true
nature of this long period signal.


title:
A large population study of protoplanetary disks: Explaining the
  millimeter size-luminosity relation with or without sub-structure

abstract:
  Recent sub-arcsecond resolution surveys of the dust continuum emission from
nearby protoplanetary disks showed a strong correlation between the sizes and
luminosities of the disks. We aim to explain the origin of the (sub-)millimeter
size-luminosity relation (SLR) between the $68\%$ effective radius ($r_{eff}$)
of disks with their continuum luminosity ($L_{mm}$), with models of gas and
dust evolution in a simple viscous accretion disk and radiative transfer
calculations. We use a large grid of models ($10^{5}$ simulations) with and
without planetary gaps, varying the initial conditions of the key parameters.
We calculate the disk continuum emission and the effective radius for all
models as a function of time. By selecting those simulations that continuously
follow the SLR, we can derive constraints on the input parameters of the
models. We confirm previous results that models of smooth disks in the radial
drift regime are compatible with the observed SLR ($L_{mm}\propto r_{eff}^{2}$)
but only smooth disks cannot be the reality. We show that the SLR is more
widely populated if planets are present. However they tend to follow a
different relation than smooth disks, potentially implying that a mixture of
smooth and sub-structured disks are present in the observed sample. We derive a
SLR ($L_{mm}\propto r_{eff}^{5/4}$) for disks with strong sub-structure. To be
compatible with the SLR, models need to have an initially high disk mass ($\geq
2.5 \cdot 10^{-2}M_{\star}$) and low turbulence-parameter $\alpha$ values
($\leq 10^{-3}$). Furthermore, we find that the grain composition and porosity
drastically affects the evolution of disks on the size-luminosity diagram where
relatively compact grains that include amorphous carbon are favoured. Moreover,
a uniformly optically thick disk with high albedo ($0.9$) that follows the SLR
cannot be formed from an evolutionary procedure.


title:
Detection of Cosmological 21 cm Emission with the Canadian Hydrogen
  Intensity Mapping Experiment

abstract:
  We present a detection of 21-cm emission from large-scale structure (LSS)
between redshift 0.78 and 1.43 made with the Canadian Hydrogen Intensity
Mapping Experiment (CHIME). Radio observations acquired over 102 nights are
used to construct maps which are foreground filtered and stacked on the angular
and spectral locations of luminous red galaxies (LRG), emission line galaxies
(ELG), and quasars (QSO) from the eBOSS clustering catalogs. We find decisive
evidence for a detection when stacking on all three tracers of LSS, with the
logarithm of the Bayes Factor equal to 18.9 (LRG), 10.8 (ELG), and 56.3 (QSO).
An alternative frequentist interpretation, based on the likelihood-ratio test,
yields a detection significance of $7.1\sigma$ (LRG), $5.7\sigma$ (ELG), and
$11.1\sigma$ (QSO). These are the first 21-cm intensity mapping measurements
made with an interferometer. We constrain the effective clustering amplitude of
neutral hydrogen (HI), defined as $\mathcal{A}_{\rm HI}\equiv
10^{3}\,\Omega_\mathrm{HI}\left(b_\mathrm{HI}+\langle\,f\mu^{2}\rangle\right)$,
where $\Omega_\mathrm{HI}$ is the cosmic abundance of HI, $b_\mathrm{HI}$ is
the linear bias of HI, and $\langle\,f\mu^{2}\rangle=0.552$ encodes the effect
of redshift-space distortions at linear order. We find
$\mathcal{A}_\mathrm{HI}=1.51^{+3.60}_{-0.97}$ for LRGs $(z=0.84)$,
$\mathcal{A}_\mathrm{HI}=6.76^{+9.04}_{-3.79}$ for ELGs $(z=0.96)$, and
$\mathcal{A}_\mathrm{HI}=1.68^{+1.10}_{-0.67}$ for QSOs $(z=1.20)$, with
constraints limited by modeling uncertainties at nonlinear scales. We are also
sensitive to bias in the spectroscopic redshifts of each tracer, and find a
non-zero bias $\Delta\,v= -66 \pm 20 \mathrm{km/s}$ for the QSOs. We split the
QSO catalog into three redshift bins and have a decisive detection in each,
with the upper bin at $z=1.30$ producing the highest redshift 21-cm intensity
mapping measurement thus far.


title:
Parameters or Privacy: A Provable Tradeoff Between Overparameterization
  and Membership Inference

abstract:
  A surprising phenomenon in modern machine learning is the ability of a highly
overparameterized model to generalize well (small error on the test data) even
when it is trained to memorize the training data (zero error on the training
data). This has led to an arms race towards increasingly overparameterized
models (c.f., deep learning). In this paper, we study an underexplored hidden
cost of overparameterization: the fact that overparameterized models are more
vulnerable to privacy attacks, in particular the membership inference attack
that predicts the (potentially sensitive) examples used to train a model. We
significantly extend the relatively few empirical results on this problem by
theoretically proving for an overparameterized linear regression model with
Gaussian data that the membership inference vulnerability increases with the
number of parameters. Moreover, a range of empirical studies indicates that
more complex, nonlinear models exhibit the same behavior. Finally, we study
different methods for mitigating such attacks in the overparameterized regime,
such as noise addition and regularization, and conclude that simply reducing
the parameters of an overparameterized model is an effective strategy to
protect it from membership inference without greatly decreasing its
generalization error.


title:
Reliably assessing the electronic structure of cytochrome P450 on
  today's classical computers and tomorrow's quantum computers

abstract:
  An accurate assessment of how quantum computers can be used for chemical
simulation, especially their potential computational advantages, provides
important context on how to deploy these future devices. In order to perform
this assessment reliably, quantum resource estimates must be coupled with
classical simulations attempting to answer relevant chemical questions and to
define the classical simulation frontier. Herein, we explore the quantum and
classical resources required to assess the electronic structure of cytochrome
P450 enzymes (CYPs) and thus define a classical-quantum advantage boundary.
This is accomplished by analyzing the convergence of DMRG+NEVPT2 and coupled
cluster singles doubles with non-iterative triples (CCSD(T)) calculations for
spin-gaps in models of the CYP catalytic cycle that indicate multireference
character. The quantum resources required to perform phase estimation using
qubitized quantum walks are calculated for the same systems. Compilation into
the surface-code provides runtime estimates to compare directly to DMRG
runtimes and to evaluate potential quantum advantage. Both classical and
quantum resource estimates suggest that simulation of CYP models at scales
large enough to balance dynamic and multiconfigurational electron correlation
has the potential to be a quantum advantage problem and emphasizes the
important interplay between classical simulations and quantum algorithms
development for chemical simulation.


title:
Radiation-MagnetoHydrodynamics simulations of cosmic ray feedback in
  disc galaxies

abstract:
  Cosmic rays (CRs) are thought to play an important role in galaxy evolution.
We study their effect when coupled to other important sources of feedback,
namely supernovae and stellar radiation. Using the RAMSES-RT code, we perform
the first radiation-magnetohydrodynamics simulations of isolated disc galaxies
with and without CRs. We study galaxies embedded in dark matter haloes of
$10^{10}$, $10^{11}$ and $10^{12}\, \rm M_{\odot}$ with a maximum resolution of
$9 \,\rm pc$. We find that CRs reduce star formation rate in our two dwarf
galaxies by a factor 2, with decreasing efficiency with increasing galaxy mass.
They increase significantly the outflow mass loading factor in all our galaxies
and make the outflows colder. We study the impact of the CR diffusion
coefficient, exploring values from $\kappa = 10^{27}$ to $\rm 3\times 10^{29}\,
cm^2\, s^{-1}$. With lower $\kappa$, CRs remain confined for longer on small
scales and are consequently efficient in suppressing star formation, whereas a
higher diffusion coefficient reduces the effect on star formation and increases
the generation of cold outflows. Finally, we compare CR feedback to a
calibrated 'strong' supernova feedback model known to sufficiently regulate
star formation in high-redshift cosmological simulations. We find that CR
feedback is not sufficiently strong to replace this strong supernova feedback.
As they tend to smooth out the ISM and fill it with denser gas, CRs also lower
the escape fraction of Lyman continuum photons from galaxies.


title: PolarDenseNet: A Deep Learning Model for CSI Feedback in MIMO Systems

abstract:
  In multiple-input multiple-output (MIMO) systems, the high-resolution channel
information (CSI) is required at the base station (BS) to ensure optimal
performance, especially in the case of multi-user MIMO (MU-MIMO) systems. In
the absence of channel reciprocity in frequency division duplex (FDD) systems,
the user needs to send the CSI to the BS. Often the large overhead associated
with this CSI feedback in FDD systems becomes the bottleneck in improving the
system performance. In this paper, we propose an AI-based CSI feedback based on
an auto-encoder architecture that encodes the CSI at UE into a low-dimensional
latent space and decodes it back at the BS by effectively reducing the feedback
overhead while minimizing the loss during recovery. Our simulation results show
that the AI-based proposed architecture outperforms the state-of-the-art
high-resolution linear combination codebook using the DFT basis adopted in the
5G New Radio (NR) system.


title: On the Cubic Shimura lift to $PGL(3)$: The Fundamental Lemma

abstract:
  The classical Shimura correspondence lifts automorphic representations on the
double cover of $SL_2$ to automorphic representations on $PGL_2$. Here we take
key steps towards establishing a relative trace formula that would give a new
global Shimura lift, from the triple cover of $SL_3$ to $PGL_3$, and also
characterize the image of the lift. The characterization would be through the
nonvanishing of a certain global period involving a function in the space of
the automorphic minimal representation $\Theta_{SO_8}$ for split
$SO_8({\mathbb{A}})$, consistent with a 2001 conjecture of Bump, Friedberg and
Ginzburg. In this paper, we first analyze a global distribution on
$PGL_3({\mathbb{A}})$ involving this period and show that it is a sum of
factorizable orbital integrals. The same is true for the Kuznetsov distribution
attached to the triple cover of $SL_3({\mathbb{A}})$. We then match the
corresponding local orbital integrals for the unit elements of the spherical
Hecke algebras; that is, we establish the Fundamental Lemma.


title:
Passing the Limits of Pure Local Search for the Maximum Weight
  Independent Set Problem in d-Claw Free Graphs

abstract:
  In this paper, we consider the task of computing an independent set of
maximum weight in a given $d$-claw free graph $G=(V,E)$ equipped with a
positive weight function $w:V\rightarrow\mathbb{R}_{>0}$. Recently, Neuwohner
has shown how to obtain approximation ratios of $\frac{d-1+\epsilon_d}{2}$ in
quasi-polynomial time, where $0\leq \epsilon_d\leq 1$ and
$\lim_{d\rightarrow\infty}\epsilon_d = 0$. For the special case of the
$d-1$-Set Packing Problem, she showed how to get down to a polynomial running
time. On the other hand, she provided examples showing that no local
improvement algorithm considering local improvements of logarithmic size can
yield an approximation guarantee better than $\frac{d-1}{2}$. However, it turns
out that if one considers local improvements that arise by dropping vertex
weights and running an algorithm devised for the unweighted setting on certain
sub-instances of the given one, one can get beyond the
$\frac{d-1}{2}$-threshold and obtain approximation guarantees of
$\frac{d}{2}-\Omega(d)$ in quasi-polynomial time. For $d-1$-Set Packing
instances, we can guarantee a polynomial running time.
  We also conduct a more general investigation of the relation between
approximation guarantees for the unweighted and weighted variants of both the
Maximum Weight Independent Set Problem in $d$-claw free graphs and the
$d-1$-Set Packing problem. In doing so, we can show that for any constant
$\sigma > 0$, there exists a constant $\tau > 0$ such that a (quasi-)polynomial
time $1+\tau\cdot (d-2)$-approximation for the unweighted $d-1$-Set Packing
Problem (the Maximum Cardinality Independent Set problem in $d$-claw free
graphs) implies a (quasi-)-polynomial time $1+\sigma\cdot (d-2)$-approximation
for the weighted $d-1$-Set Packing Problem (the Maximum Weight Independent Set
problem in $d$-claw free graphs).


title:
Theory of Two-Photon Absorption with Broadband Bright Squeezed Vacuum:
  Part 1 Quantum Model

abstract:
  We present an analytical quantum theoretic model for molecular two-photon
absorption (TPA) of broadband, spectrally multi-mode squeezed vacuum with pulse
duration much greater than the coherence time, including low-gain (isolated
entangled photon pairs or EPP) and high-gain (bright squeezed vacuum or BSV)
regimes. We treat only cases where the exciting light is spatially single-mode
and is nonresonant with all intermediate molecular states. In the case of high
gain, we find that if the linewidth of the final molecular state is much
narrower than the bandwidth of the exciting light, bright squeezed vacuum is
found to be equally (but no more) effective in driving TPA as is a
quasi-monochromatic coherent-state (classical) pulse of the same temporal
shape, duration and mean photon number. Therefore, the sought-for advantage of
observing TPA at extremely low optical flux is not provided by broadband bright
squeezed vacuum. In the opposite case that the final-state linewidth is much
broader than the bandwidth of the BSV exciting light, we show that the TPA rate
is proportional to the second-order intensity autocorrelation function at zero
time delay g^(2)(0), as expected. And we find that for g^(2)(0) to reach the
idealized form g^(2)(0) = 3 + 1/n, with n, being the mean number of photons per
temporal mode, it is required to compensate the dispersion inherent in the
nonlinear-optical crystal used to generate the BSV. Part 2 of this two-paper
series considers the same questions in the context of a classical model of
squeezed light and also extends the analysis to the case of sum-frequency
generation.


title: Catoni-style confidence sequences for heavy-tailed mean estimation

abstract:
  A confidence sequence (CS) is a sequence of confidence intervals that is
valid at arbitrary data-dependent stopping times. These are useful in
applications like A/B testing, multi-armed bandits, off-policy evaluation,
election auditing, etc. We present three approaches to constructing a
confidence sequence for the population mean, under the assumption that only an
upper bound $\sigma^2$ on the variance is known. While previous works rely on
light-tail assumptions like boundedness or subGaussianity (under which all
moments of a distribution exist), the confidence sequences in our work are able
to handle data from a wide range of heavy-tailed distributions. The best among
our three methods -- the Catoni-style confidence sequence -- performs
remarkably well in practice, essentially matching the state-of-the-art methods
for $\sigma^2$-subGaussian data. Our findings have important implications for
sequential experimentation with unbounded observations, since the
$\sigma^2$-bounded-variance assumption is more realistic and easier to verify
than $\sigma^2$-subGaussianity (which implies the former).


title:
Pulsar Observations at Low Frequencies: Applications to Pulsar Timing
  and Solar Wind Models

abstract:
  Efforts are underway to use high-precision timing of pulsars in order to
detect low-frequency gravitational waves. A limit to this technique is the
timing noise generated by dispersion in the plasma along the line of sight to
the pulsar, including the solar wind. The effects due to the solar wind vary
with time, influenced by the change in solar activity on different time scales,
ranging up to $\sim 11$ years for a solar cycle. The solar wind contribution
depends strongly on the angle between the pulsar line of sight and the solar
disk, and is a dominant effect at small separations. Although solar wind models
to mitigate these effects do exist, they do not account for all the effects of
the solar wind and its temporal changes. Since low-frequency pulsar
observations are most sensitive to these dispersive delays, they are most
suited to test the efficacy of these models and identify alternative
approaches. Here, we investigate the efficacy of some solar wind models
commonly used in pulsar timing using long-term, high-cadence data on 6 pulsars
taken with the Long Wavelength Array, and compare them with an operational
solar wind model. Our results show that stationary models of the solar wind
correction are insufficient to achieve the timing noise desired by pulsar
timing experiments, and we need to use non-stationary models, which are
informed by other solar wind observations, to obtain accurate timing residuals.


title: Speaker Normalization for Self-supervised Speech Emotion Recognition

abstract:
  Large speech emotion recognition datasets are hard to obtain, and small
datasets may contain biases. Deep-net-based classifiers, in turn, are prone to
exploit those biases and find shortcuts such as speaker characteristics. These
shortcuts usually harm a model's ability to generalize. To address this
challenge, we propose a gradient-based adversary learning framework that learns
a speech emotion recognition task while normalizing speaker characteristics
from the feature representation. We demonstrate the efficacy of our method on
both speaker-independent and speaker-dependent settings and obtain new
state-of-the-art results on the challenging IEMOCAP dataset.


title: Complex cobordism with involutions and geometric orientations

abstract:
  We calculate the cobordism ring $\Omega^{C_2}_*$ of stably almost complex
manifolds with involution, and investigate the $C_2$-spectrum $\Omega_{C_2}$
which represents it. We introduce the notion of a geometrically oriented
$C_2$-spectrum, which extends the notion of a complex oriented $C_2$-spectrum,
and of which $\Omega_{C_2}$ is the universal example. Examples, in addition to
$\Omega_{C_2}$, include the Eilenberg-Maclane spectrum $H
\underline{\mathbb{Z}}_{C_2}$ and the connective cover $k_{C_2}$ of
$C_2$-equivariant $K$-theory. On the algebraic side, we define and study
filtered $C_2$-equivariant formal group laws, which are the algebraic
structures determined by geometrically oriented $C_2$-spectra. We prove some of
the fundamental properties of filtered $C_2$-equivariant formal group laws, as
well as a universality statement for the filtered $C_2$-equivariant formal
group law determined by $\Omega_{C_2}$.