title: Machine Learning Security against Data Poisoning: Are We There Yet?

abstract:
  The recent success of machine learning has been fueled by the increasing
availability of computing power and large amounts of data in many different
applications. However, the trustworthiness of the resulting models can be
compromised when such data is maliciously manipulated to mislead the learning
process. In this article, we first review poisoning attacks that compromise the
training data used to learn machine-learning models, including attacks that aim
to reduce the overall performance, manipulate the predictions on specific test
samples, and even implant backdoors in the model. We then discuss how to
mitigate these attacks before, during, and after model training. We conclude
our article by formulating some relevant open challenges which are hindering
the development of testing methods and benchmarks suitable for assessing and
improving the trustworthiness of machine-learning models against data poisoning
attacks.


title:
Snapping for high-speed and high-efficient, butterfly swimming-like soft
  flapping-wing robot

abstract:
  Natural selection has tuned many flying and swimming animals across different
species to share the same narrow design space for optimal high-efficient and
energy-saving locomotion, e.g., their dimensionless Strouhal numbers St that
relate flapping frequency and amplitude and forward speed fall within the range
of 0.2 < St < 0.4 for peak propulsive efficiency. It is rather challenging to
achieve both fast and high-efficient soft-bodied swimming robots with high
performances that are comparable to marine animals, due to the observed narrow
optimal design space in nature and the compliance of soft body. Here,
bioinspired by the wing or fin flapping motion in flying and swimming animals,
we report leveraging the generic principle of snapping instabilities in the
bistable and multistable flexible pre-curved wings for high-performance,
butterfly swimming-like, soft-bodied flapping-wing robots. The soft swimming
robot is lightweight (2.8 grams) and demonstrates a record-high speed of 3.74
body length/s (4.8 times faster than the reported fastest soft swimmer),
high-efficient (0.2 < St = 0.25 < 0.4), low energy consumption cost, and high
maneuverability (a high turning speed of 157o /s). Its high performances
largely outperform the state-of-the-art soft swimming robots and are even
comparable to its biological counterparts.


title:
Sparse grid time-discontinuous Galerkin method with streamline diffusion
  for transport equations

abstract:
  High-dimensional transport equations frequently occur in science and
engineering. Computing their numerical solution, however, is challenging due to
its high dimensionality.
  In this work we develop an algorithm to efficiently solve the transport
equation in moderately complex geometrical domains using a Galerkin method
stabilized by streamline diffusion. The ansatz spaces are a tensor product of a
sparse grid in space and discontinuous piecewise polynomials in time. Here, the
sparse grid is constructed upon nested multilevel finite element spaces to
provide geometric flexibility. This results in an implicit time-stepping scheme
which we prove to be stable and convergent. If the solution has additional
mixed regularity, the convergence of a $2d$-dimensional problem equals that of
a $d$-dimensional one up to logarithmic factors.
  For the implementation, we rely on the sparse grid combination technique,
which enables us to store the functions and to carry out the computations on a
sequence of anisotropic full grids exploiting the tensor product structure of
the ansatz spaces. In this way existing finite element libraries and GPU
acceleration can be used. The combination technique is also used as a
preconditioner for an iterative scheme to solve the transport equation on the
sequence of time strips.
  Numerical tests show that the method works well for problems in up to six
dimensions. Finally, the method is also used as a building block to solve
nonlinear Vlasov-Poisson equations.


title:
Labor advantages drive the greater productivity of faculty at elite
  universities

abstract:
  Faculty at prestigious institutions dominate scientific discourse, with the
small proportion of researchers at elite universities producing a
disproportionate share of all research publications. Environmental prestige is
known to drive such epistemic disparity, but the mechanisms by which it causes
increased faculty productivity remain unknown. Here we combine employment,
publication, and federal survey data for 78,802 tenure-track faculty at 262
PhD-granting institutions in the American university system between 2008--2017
to show through multiple lines of evidence that the greater availability of
funded graduate and postdoctoral labor at more prestigious institutions drives
the environmental effect of prestige on productivity. In particular, we show
that greater environmental prestige leads to larger faculty-led research
groups, which drive higher faculty productivity, primarily in disciplines with
research group collaboration norms. In contrast, we show that productivity does
not increase substantially with prestige for either faculty papers published
without group members, nor group members themselves. The disproportionate
scientific productivity of elite researchers is thus largely explained by their
substantial labor advantage, indicating a more limited role for prestige itself
in predicting scientific contributions.


title:
Detection, Disambiguation, Re-ranking: Autoregressive Entity Linking as
  a Multi-Task Problem

abstract:
  We propose an autoregressive entity linking model, that is trained with two
auxiliary tasks, and learns to re-rank generated samples at inference time. Our
proposed novelties address two weaknesses in the literature. First, a recent
method proposes to learn mention detection and then entity candidate selection,
but relies on predefined sets of candidates. We use encoder-decoder
autoregressive entity linking in order to bypass this need, and propose to
train mention detection as an auxiliary task instead. Second, previous work
suggests that re-ranking could help correct prediction errors. We add a new,
auxiliary task, match prediction, to learn re-ranking. Without the use of a
knowledge base or candidate sets, our model sets a new state of the art in two
benchmark datasets of entity linking: COMETA in the biomedical domain, and
AIDA-CoNLL in the news domain. We show through ablation studies that each of
the two auxiliary tasks increases performance, and that re-ranking is an
important factor to the increase. Finally, our low-resource experimental
results suggest that performance on the main task benefits from the knowledge
learned by the auxiliary tasks, and not just from the additional training data.


title:
ReCLIP: A Strong Zero-Shot Baseline for Referring Expression
  Comprehension

abstract:
  Training a referring expression comprehension (ReC) model for a new visual
domain requires collecting referring expressions, and potentially corresponding
bounding boxes, for images in the domain. While large-scale pre-trained models
are useful for image classification across domains, it remains unclear if they
can be applied in a zero-shot manner to more complex tasks like ReC. We present
ReCLIP, a simple but strong zero-shot baseline that repurposes CLIP, a
state-of-the-art large-scale model, for ReC. Motivated by the close connection
between ReC and CLIP's contrastive pre-training objective, the first component
of ReCLIP is a region-scoring method that isolates object proposals via
cropping and blurring, and passes them to CLIP. However, through controlled
experiments on a synthetic dataset, we find that CLIP is largely incapable of
performing spatial reasoning off-the-shelf. Thus, the second component of
ReCLIP is a spatial relation resolver that handles several types of spatial
relations. We reduce the gap between zero-shot baselines from prior work and
supervised models by as much as 29% on RefCOCOg, and on RefGTA (video game
imagery), ReCLIP's relative improvement over supervised ReC models trained on
real images is 8%.


title: On the implications of positive W mass shift

abstract:
  We investigate the phenomenological implications of the recent $W$ mass
measurement by the CDF collaboration, which exhibits tension with the standard
model (SM) electroweak fit. Performing the fit to the electroweak observables
within the SM effective field theory, we find that the new physics that
contributes either to the determination of the electroweak vacuum expectation
value, or to the oblique parameters, can improve the agreement with data. The
best description is obtained from a fit where flavor universality is not
required in the new physics operators, with 2 to 3 $\sigma$ indications for
several nonzero Wilson coefficients. We point out that top partners with order
TeV masses could lead to the observed shift in the $W$ mass.


title:
Fusion dynamics of heavy-ion reactions using density dependent
  relativistic nucleon-nucleon potential

abstract:
  In-medium effects are introduced in the microscopic description of the
effective nucleon-nucleon (NN) interaction potential entitled DDR3Y in terms of
the density-dependent nucleon-meson couplings within the
Relativistic-Hartree-Bogoliubov (RHB) approach. The nuclear densities of the
interacting target and projectile nuclei and NN potentials are obtained for
non-linear NL3$^*$ and TM1 parameter sets within the relativistic mean-field
approach and density-dependent DDME1 and DDME2 parameter sets within
Relativistic-Hartree-Bogoliubov (RHB) formalism. The DDR3Y NN potential and the
densities are used to obtain the nuclear potential by adopting the double
folding approach. This nuclear potential is further used to probe the fusion
dynamics within the $\ell-$summed Wong model a few even-even systems leading to
the formation of light, heavy and superheavy nuclei. The calculations are also
performed for density-dependent DDM3Y and the density-independent M3Y and R3Y
NN interaction potentials for the sake of comparison. We observed that the
DDR3Y NN potential gives a better overlap with the experimental data as
compared to non-relativistic M3Y and DDM3Y NN potentials. From the comparison
of R3Y and DDR3Y interactions, it is manifested that the inclusion of in-medium
effects in the NN interaction raises the fusion barrier and consequently
decreases the fusion and/or capture cross-section. Moreover, the nuclear
densities, as well as relativistic R3Y NN potential obtained for the more
recent NL3$^*$ RMF parameter set, are observed to give a comparatively better
fit to the experimental data.


title:
Malceiver: Perceiver with Hierarchical and Multi-modal Features for
  Android Malware Detection

abstract:
  We propose the Malceiver, a hierarchical Perceiver model for Android malware
detection that makes use of multi-modal features. The primary inputs are the
opcode sequence and the requested permissions of a given Android APK file. To
reach a malware classification decision the model combines hierarchical
features extracted from the opcode sequence together with the requested
permissions. The model's architecture is based on the Perceiver/PerceiverIO
which allows for very long opcode sequences to be processed efficiently. Our
proposed model can be easily extended to use multi-modal features. We show
experimentally that this model outperforms a conventional CNN architecture for
opcode sequence based malware detection. We then show that using additional
modalities improves performance. Our proposed architecture opens new avenues
for the use of Transformer-style networks in malware research.


title:
Communication and Computation Assisted Sensing Information Freshness
  Performance Analysis in Vehicular Networks

abstract:
  The timely sharing of raw sensing information in the vehicular networks
(VNETs) is essential to safety. In order to improve the freshness of sensing
information, joint scheduling of multi-dimensional resources such as
communication and computation is required. However, the complex relevance among
multi-dimensional resources is still unclear, and it is difficult to achieve
efficient resource utilization. In this paper, we present a theoretical
analysis for a novel metric Age of Information (AoI) on a communication and
computation assisted spatial-temporal model. An uplink VNETs scenario where
Road Side Units (RSUs) are deployed with computational resource is considered.
The transmission and computation process is unified into a two-stage tandem
queue and the expression of the average AoI is derived. The network
interference is analyzed by modeling the VNETs as Cox Poisson Point Process
based on stochastic geometry and the closed-form solution of the coverage
probability and the expected data rate performance under the constraints of
transmission resources is obtained. The simulation results reveal the basic
relationship between communication and computation capacity and show that
communication and computation should reach a tradeoff to improve resource
utilization while ensuring real-time information requirement.


title:
Thermodynamic stability and P-V criticality of nonsingular-AdS black
  holes endowed with clouds of strings

abstract:
  We investigate the extended phase space thermodynamics of nonsingular-AdS
black holes minimally coupled to clouds of strings in which we consider the
cosmological constant ($\Lambda$) as the pressure ($P$) of the black holes and
its conjugate variable thermodynamical volume ($V$) of the black holes. Owing
to the background clouds of strings parameter ($a$), we analyse the Hawking
temperature, entropy and specific heat on horizon radius for fixed-parameter
$k$. We find that the strings clouds background does not alter small/large
black hole (SBH/LBH) phase transition but occurs at a larger horizon radius,
and two second-order phase transitions occur at a smaller horizon radius.
Indeed, the $G$--$T$ plots exhibit a swallowtail below the critical pressure,
implying that the first-order phase transition is analogous to the liquid-gas
phase transition at a lower temperature and lower critical pressure. To further
examine the analogy between nonsingular-AdS black holes and a liquid-gas
system, we derive the exact critical points and probe the effects of a cloud of
strings on $P-V$ criticality to find that the isotherms undergo liquid-gas like
phase transition for $\tilde{T}\,<\,\tilde{T}_c$ at lower $\tilde{T}_c$. We
have also calculated the critical exponents identical with Van der Walls fluid,
i.e., same as those obtained before for arbitrary other AdS black holes, which
implies that the background clouds of strings do not change the critical
exponents.


title:
Geometric post-Newtonian description of spin-half particles in curved
  spacetime

abstract:
  Einstein Equivalence Principle (EEP) requires all matter components to
universally couple to gravity via a single common geometry: that of spacetime.
This relates quantum theory with geometry as soon as interactions with gravity
are considered. In this work, I study the geometric theory of coupling a
spin-1/2 particle to gravity in a twofold expansion scheme: First with respect
to the distance based on Fermi normal coordinates around a preferred worldline
(e.g., that of a clock in the laboratory), second with respect to 1/c
(post-Newtonian expansion). I consider the one-particle sector of a massive
spinor field in QFT, here described effectively by a classical field. The
formal expansion in powers of 1/c yields a systematic and complete generation
of GR corrections for quantum systems. I find new terms that were overlooked in
the literature at order 1/c and extended the level of approximation to the next
order. These findings are significant for a consistent inclusion of gravity
corrections in the description of quantum experiments of corresponding
sensitivities, and also for testing aspects of GR, like the EEP, in the quantum
realm.


title:
Numerical Regge pole analysis of resonance structures in elastic,
  inelastic and reactive state-to-state integral cross sections

abstract:
  We present a detailed description of a FORTRAN code for evaluation of the
resonance contribution a Regge trajectory makes to the integral state-to-state
cross section (ICS) within a specified range of energies. The contribution is
evaluated with the help of the Mulholland formula [Macek et al (2004)] and its
variants [Sokolovski et al (2007); Sokolovski and Akhmatskaya (2011)]. Regge
pole positions and residues are obtained by analytically continuing S-matrix
element, evaluated numerically for the physical values of the total angular
momentum, into the complex angular momentum plane using the PADE II program
[Sokolovski et al (2011)]. The code decomposes an elastic, inelastic, or
reactive ICS into a structured, resonance, and a smooth, "direct", components,
and attributes observed resonance structure to resonance Regge trajectories.
The package has been successfully tested on several models, as well as the F +
H2->HF+H benchmark reaction. Several detailed examples are given in the text.


title: InCoder: A Generative Model for Code Infilling and Synthesis

abstract:
  Code is seldom written in a single left-to-right pass and is instead
repeatedly edited and refined. We introduce InCoder, a unified generative model
that can perform program synthesis (via left-to-right generation) as well as
editing (via infilling). InCoder is trained to generate code files from a large
corpus of permissively licensed code, where regions of code have been randomly
masked and moved to the end of each file, allowing code infilling with
bidirectional context. Our model is the first generative model that is able to
directly perform zero-shot code infilling, which we evaluate on challenging
tasks such as type inference, comment generation, and variable re-naming. We
find that the ability to condition on bidirectional context substantially
improves performance on these tasks, while still performing comparably on
standard program synthesis benchmarks in comparison to left-to-right only
models pretrained at similar scale. The InCoder models and code are publicly
released. https://sites.google.com/view/incoder-code-models


title:
3D Morphology of Open Clusters in the Solar Neighborhood with Gaia EDR3
  II: Hierarchical Star Formation Revealed by Spatial and Kinematic
  Substructures

abstract:
  We identify members of 65 open clusters in the solar neighborhood using the
machine-learning algorithm StarGO based on Gaia EDR3 data. After adding members
of twenty clusters from previous studies (Pang et al. 2021a,b; Li et al. 2021)
we obtain 85 clusters, and study their morphology and kinematics. We classify
the substructures outside the tidal radius into four categories: filamentary
(f1) and fractal (f2) for clusters $<100$ Myr, and halo (h) and tidal-tail (t)
for clusters $>100$ Myr. The kinematical substructures of f1-type clusters are
elongated; these resemble the disrupted cluster Group X. Kinematic tails are
distinct in t-type clusters, especially Pleiades. We identify 29 hierarchical
groups in four young regions (Alessi 20, IC 348, LP 2373, LP 2442); ten among
these are new. The hierarchical groups form filament networks. Two regions
(Alessi 20, LP 2373) exhibit global "orthogonal" expansion (stellar motion
perpendicular to the filament), which might cause complete dispersal.
Infalling-like flows (stellar motion along the filament) are found in UBC 31
and related hierarchical groups in the IC 348 region. Stellar groups in the LP
2442 region (LP 2442 gp 1-5) are spatially well-mixed but kinematically
coherent. A merging process might be ongoing in the LP 2442 subgroups. For
younger systems ($\lesssim30$ Myr), the mean axis ratio, cluster mass and
half-mass radius tend to increase with age values. These correlations between
structural parameters may imply two dynamical processes occurring in the
hierarchical formation scenario in young stellar groups: (1) filament
dissolution and (2) sub-group mergers.


title:
Constraining Primordial Black Holes using Fast Radio Burst
  Gravitational-Lens Interferometry with CHIME/FRB

abstract:
  Fast radio bursts (FRBs) represent an exciting frontier in the study of
gravitational lensing, due to their brightness, extragalactic nature, and the
compact, coherent characteristics of their emission. In a companion work
[Kader, Leung+2022], we use a novel interferometric method to search for
gravitationally lensed FRBs in the time domain using bursts detected by
CHIME/FRB. There, we dechannelize and autocorrelate electric field data at a
time resolution of 1.25 ns. This enables a search for FRBs whose emission is
coherently deflected by gravitational lensing around a foreground compact
object such as a primordial black hole (PBH). Here, we use our non-detection of
lensed FRBs to place novel constraints on the PBH abundance outside the Local
Group. We use a novel two-screen model to take into account decoherence from
scattering screens in our constraints. Our constraints are subject to a single
astrophysical model parameter -- the effective distance between an FRB source
and the scattering screen, for which we adopt a fiducial distance of 1 parsec.
We find that coherent FRB lensing is a sensitive probe of sub-solar mass
compact objects. Having observed no lenses in $172$ bursts from $114$
independent sightlines through the cosmic web, we constrain the fraction of
dark matter made of compact objects, such as PBHs, to be $f \lesssim 0.8$, if
their masses are $\sim 10^{-3} M_{\odot}$.


title:
Eccentric Mergers of Intermediate-Mass Black Holes from Evection
  Resonances in AGN Disks

abstract:
  We apply the theory of nonlinear resonance capture to the problem of a black
hole binary (BHB) orbiting a supermassive black hole (SMBH) while embedded in
the accretion disk of an active galactic nucleus (AGN). If successful,
resonance capture can trigger dramatic growth in the BHB eccentricity, with
important consequences for the BHB merger timescale, as well as for the
gravitational wave (GW) signature of such an eccentric merger. This resonance
capture may occur when the orbital period around the SMBH (the "outer binary")
and the apsidal precession of the BHB (the "inner binary") are in a 1:1
commensurability. This effect is analogous to the phenomenon of lunar evection
resonance in the early Sun-Earth-Moon system, with the distinction that in the
present case, the BHB apsidal precession is due to general relativity, rather
than rotationally-induced distortion. In contrast to the case of lunar
evection, however, the inner binary undergoes orbital decay driven by GW
emission, rather than orbital expansion driven by tidal dissipation. This
distinction fundamentally alters the three-body dynamics, forbidding resonance
capture, and limiting eccentricity growth. However, if the BHB migrates through
of a gaseous AGN disk, the change in the outer binary can counterbalance the
suppressing effect of BHB decay, permitting evection resonance capture and the
production of eccentric BHB mergers. We compute the likelihood of resonance
capture assuming an agnostic distribution of parameters for the three bodies
involved and for the properties of the AGN disk. We find that intermediate-mass
ratio BHBs (involving an intermediate-mass black hole and a stellar-mass black
hole) are the most likely to be captured into evection resonance and thus
undergo an eccentric merger. We also compute the GW signature of these mergers,
showing that they can enter the LISA band while eccentric.


title: The Radcliffe Wave as the gas spine of the Orion Arm

abstract:
  The Radcliffe Wave is a $\sim3$ kpc long coherent gas structure containing
most of the star-forming complexes near the Sun. In this Letter we aim to find
a Galactic context for the Radcliffe Wave by looking into a possible
relationship between the gas structure and the Orion (Local) Arm. We use
catalogs of massive stars and young open clusters based on \textit{Gaia} EDR3
astrometry, in conjunction with kiloparsec-scale 3D dust maps, to investigate
the Galactic \textit{XY} spatial distributions of gas and young stars. We find
a quasi-parallel offset between the luminous blue stars and the Radcliffe Wave,
in that massive stars and clusters are found essentially inside and downstream
from the Radcliffe Wave. We examine this offset in the context of color
gradients observed in the spiral arms of external galaxies, where the interplay
between density wave theory, spiral shocks, and triggered star formation has
been used to interpret this particular arrangement of gas/dust and OB stars,
and outline other potential explanations as well. We hypothesize that the
Radcliffe Wave constitutes the gas reservoir of the Orion (Local) Arm, and
presents itself as a prime laboratory to study the interface between Galactic
structure, the formation of molecular clouds in the Milky Way, and star
formation.


title: Probing carrier interactions using electron hydrodynamics

abstract:
  Electron hydrodynamics arises when momentum-relaxing scattering processes are
slow compared to momentum-conserving ones. While the microscopic details
necessary to satisfy this condition are material-specific, experimentally
accessible current densities share remarkable similarities. We study the
dependence of electron hydrodynamic flows on the rates of momentum-relaxing and
momentum-conserving scattering processes in a microscopics-agnostic way. We
develop a framework for generating random collision operators which respect
crystal symmetries and conservation laws and which have a tunable ratio between
the momentum-conserving and momentum-relaxing lifetimes. Using various random
instances of these collision operators, we calculate macroscopic electron
viscosity tensors and solve the Boltzmann transport equation (BTE) in a channel
geometry over a grid of momentum-conserving and momentum-relaxing lifetimes,
and for different crystal symmetry groups. We find that different random
collision operators using the same lifetimes produce very similar current
density profiles, meaning that the current density is primarily a probe of the
overall rates of momentum conservation and relaxation. By contrast, the
viscosity tensor varies substantially at fixed lifetimes, meaning that
properties like channel resistance provide detailed probes of the underlying
scattering processes. This suggests that, while details of the scattering
process are imprinted in the electronic viscosity tensor, for many applications
theoretical calculations of hydrodynamic electron flows can use
experimentally-available lifetimes within a spatially-resolved BTE framework
rather than requiring the costly computation of ab initio collision operators.


title:
Improved limits on lepton-flavor-violating decays of light pseudoscalars
  via spin-dependent $\mu\to e$ conversion in nuclei

abstract:
  Lepton-flavor-violating decays of light pseudoscalars,
$P=\pi^0,\eta,\eta'\to\mu e$, are stringently suppressed in the Standard Model
up to tiny contributions from neutrino oscillations, so that their observation
would be a clear indication for physics beyond the Standard Model. However, in
effective field theory such decays proceed via axial-vector, pseudoscalar, or
gluonic operators, which are, at the same time, probed in spin-dependent
$\mu\to e$ conversion in nuclei. We derive master formulae that connect both
processes in a model-independent way in terms of Wilson coefficients, and study
the implications of current $\mu\to e$ limits in titanium for the $P\to\mu e$
decays. We find that these indirect limits surpass direct ones by many orders
of magnitude.


title: Fracton hydrodynamics without time-reversal symmetry

abstract:
  We present an effective field theory for the nonlinear fluctuating
hydrodynamics of a single conserved charge with or without time-reversal
symmetry, based on the Martin-Siggia-Rose formalism. Applying this formalism to
fluids with only charge and multipole conservation, and with broken
time-reversal symmetry, we predict infinitely many new dynamical universality
classes, including some with arbitrarily large upper critical dimensions. Using
large scale simulations of classical Markov chains, we find numerical evidence
for a breakdown of hydrodynamics in quadrupole-conserving models with broken
time-reversal symmetry in one spatial dimension.


title:
Measuring quasi-normal mode amplitudes with misaligned binary black hole
  ringdowns

abstract:
  In recent work, we examined how different modes in the ringdown phase of a
binary coalescence are excited as a function of the final plunge geometry. At
least in the large mass ratio limit, we found a clean mapping between angles
describing the plunge and the amplitude of different quasi-normal modes (QNMs)
which constitute the ringdown. In this study, we use that mapping to construct
a waveform model expressed as a sum of QNMs where the mode amplitudes and
phases are determined by the source plunge parameters. We first generate a
large number of calibration waveforms and interpolate between fits of each mode
amplitude and phase up to $\ell \leq 8$ and $\ell - |m| \leq 4$. The density of
our calibration data allows us to resolve important features such as phase
transition discontinuities at large misalignments. Using our ringdown waveform
model, we then perform Bayesian parameter estimation with added white Gaussian
noise to demonstrate that, in principle, the mode amplitudes can be measured
and used to constrain the plunge geometry. We find that inferences are
substantially improved by incorporating prior information constraining mode
excitation, which motivates work to understand and characterize how the QNM
excitation depends on the coalescence geometry. These results are part of a
broader effort to map the mode excitation from arbitrary masses and spins,
which will be useful for characterizing ringdown waves in upcoming
gravitational-wave measurements.


title: Robust Features of Off-Axis Gamma-Ray Burst Afterglow Lightcurves

abstract:
  The ultra-relativistic outflows powering gamma-ray bursts (GRBs) acquire
angular structure through their interaction with stellar material (dynamical
ejecta) in long-soft (short-hard) GRBs. They can often be characterized by a
compact, nearly uniform narrow core (with half-opening angle
$\theta_{c,\{\epsilon,\Gamma\}}$) surrounded by material with energy per unit
solid angle ($\epsilon=\epsilon_c\Theta_{\epsilon}^{-a}$, where
$\Theta_{\{\epsilon,\Gamma\}}=[1+\theta^2/\theta_{c,\{\epsilon,\Gamma\}}^2]^{1/2}$)
and initial specific kinetic energy
($\Gamma_0-1=[\Gamma_c-1]\Theta_\Gamma^{-b}$) declining as power laws.
Multi-wavelength afterglow lightcurves of off-axis jets (with viewing angle
$\theta_{obs} >\theta_c$) offer robust ways to constrain a, b and the external
density radial profile ($\rho\propto R^{-k}$), even while other burst
parameters may remain highly degenerate. We extend our work BGG2020 on such
afterglows to include more realistic angular structure profiles derived from
three-dimensional hydrodynamic simulations of GRBs (addressing also jets with
shallow angular energy profiles, whose emission exhibits unique evolution). We
present afterglow lightcurves based on our parameterized power-law jet angular
profiles for different viewing angles $\theta_{obs}$ and k=0,1,2. We identify a
unique evolutionary power-law phase of the characteristic synchrotron
frequencies ($\nu_m$ and $\nu_c$) that manifests when the lightcurve is
dominated by emission sensitive to the angular structure of the outflow. We
calculate the criterion for obtaining single or double peaked light curves in
the general case when $\theta_{c,\Gamma}\neq\theta_{c,\epsilon}$. Following our
earlier work, we emphasize how the shape of the lightcurve and the temporal
evolution of $\nu_m$ and $\nu_c$ can be used to constrain the outflow structure
and potentially distinguish between magnetic and hydrodynamic jets.


title:
Loops, Local Corrections and Warping in the LVS and other Type IIB
  Models

abstract:
  To establish metastable de Sitter vacua or even just scale-separated AdS,
control over perturbative corrections to the string-derived leading-order 4d
lagrangian is crucial. Such corrections can be classified in three types:
First, there are genuine loop effects, insensitive to the UV completion of the
10d theory. Second, there are local $\alpha'$ corrections or, equivalently, 10d
higher-dimension operators which may or may not be related to loop-effects.
Third, warping corrections affect the 4d Kahler potential but are expected not
to violate the 4d no-scale structure. With this classification in mind, we
attempt to derive the Berg-Haack-Pajer conjecture for Kahler corrections in
type-IIB Calabi-Yau orientifolds and extend it to include further terms. This
is crucial since the interesting applications of this conjecture are in the
context of generic Calabi-Yau geometries rather than in the torus-based models
from which the main motivation originally stems. As an important by-product, we
resolve a known apparent inconsistency between the parametric behaviour of
string loop results and field-theoretic expectations. Our findings lead to some
interesting new statements concerning loop effects associated with
blowup-cycles, loop corrections in fibre inflation, and possible logarithmic
effects in the Kahler and scalar potential.


title: Solar Flares and Magnetic Helicity

abstract:
  Solar flares and coronal mass ejections are the largest energy release
phenomena in the current solar system. They cause drastic enhancements of
electromagnetic waves of various wavelengths and sometimes eject coronal
material into the interplanetary space, disturbing the magnetic surroundings of
orbiting planets including the Earth. It is generally accepted that solar
flares are a phenomenon in which magnetic energy stored in the solar atmosphere
above an active region is suddenly released through magnetic reconnection.
Therefore, to elucidate the nature of solar flares, it is critical to estimate
the complexity of the magnetic field and track its evolution. Magnetic
helicity, a measure of the twist of coronal magnetic structures, is thus used
to quantify and characterize the complexity of flare-productive active regions.
This chapter provides an overview of solar flares and discusses how the
different concepts of magnetic helicity are used to understand and predict
solar flares.


title:
High-z Sudoku: A diagnostic tool for identifying robust (sub)mm
  redshifts

abstract:
  We present methods to (i) graphically identify robust redshifts using
emission lines in the (sub)mm regime, (ii) evaluate the capabilities of
different (sub)mm practices for measuring spectroscopic redshifts, and (iii)
optimise future (sub)mm observations towards increasing the fraction of robust
redshifts. Using this publicly-available code
(https://github.com/tjlcbakx/redshift-search-graphs), we discuss scenarios
where robust redshifts can be identified using both single- and multiple-line
detections, as well as scenarios where the redshift remains ambiguous, even
after the detection of multiple lines. Using the redshift distribution of
(sub)mm samples, we quantify the efficiencies of various practices for
measuring spectroscopic redshifts, including interferometers, as well as
existing and future instruments specifically designed for redshift searches.
Finally, we provide a method to optimise the observation strategy for future
(sub)mm spectroscopic redshift searches with the Atacama Large
Millimetre/submillimetre Array, where 2 mm proves indispensable for robust
redshifts in the z = 2 - 4 region.


title:
Observational evidence for a spin-up line in the P-Pdot diagram of
  millisecond pulsars

abstract:
  It is believed that millisecond pulsars attain their fast spins by accreting
matter and angular momentum from companion stars. Theoretical modelling of the
accretion process suggests a spin-up line in the period-period derivative
($P$-$\dot{P}$) diagram of millisecond pulsars, which plays an important role
in population studies of radio millisecond pulsars and accreting neutron stars
in X-ray binaries. Here we present observational evidence for such a spin-up
line using a sample of 46 radio millisecond pulsars with $P< 10$ ms and
intrinsic spin-down rate $\gtrsim 10^{-20}$. We also find that PSRs
J1823$-$3021A and J1824$-$2452A, located near the classic spin-up line, are
consistent with the broad population of millisecond pulsars. Finally, we show
that our approach of Bayesian inference can probe accretion physics, allowing
constraints to be placed on the accretion rate and the disk-magnetosphere
interaction.


title: ALMA Discovery of a Disk around the Planetary-mass Companion SR 12 c

abstract:
  We report an Atacama Large Millimeter/submillimeter Array 0.88 mm (Band 7)
continuum detection of the accretion disk around SR 12 c, an $\sim$11 $M_{\rm
Jup}$ planetary-mass companion (PMC) orbiting its host binary at 980 au. This
is the first submillimeter detection of a circumplanetary disk around a wide
PMC. The disk has a flux density of $127 \pm14~\mu$Jy and is not resolved by
the $\sim$0.1" beam, so the dust disk radius is likely less than 5 au and can
be much smaller if the dust continuum is optically thick. If, however, the dust
emission is optically thin, then the SR 12 c disk has a comparable dust mass to
the circumplanetary disk around PDS 70 c but is about five times lower than
that of the $\sim$12 $M_{\rm Jup}$ free-floating OTS 44. This suggests that
disks around bound and unbound planetary-mass objects can span a wide range of
masses. The gas mass estimated with an accretion rate of $10^{-11}~M_\odot$
yr$^{-1}$ implies a gas-to-dust ratio higher than 100. If cloud absorption is
not significant, a nondetection of ${}^{12}$CO(3-2) implies a compact gas disk
around SR 12 c. Future sensitive observations may detect more PMC disks at 0.88
mm flux densities of $\lesssim$100 $\mu$Jy.


title:
A High-Time Resolution Search for Compact Objects using Fast Radio Burst
  Gravitational Lens Interferometry with CHIME/FRB

abstract:
  The gravitational field of compact objects, such as primordial black holes,
can create multiple images of background sources. For transients such as fast
radio bursts (FRBs), these multiple images can be resolved in the time domain.
Under certain circumstances, these images not only have similar burst
morphologies but are also phase-coherent at the electric field level. With a
novel dechannelization algorithm and a matched filtering technique, we search
for repeated copies of the same electric field waveform in observations of FRBs
detected by the FRB backend of the Canadian Hydrogen Mapping Intensity
Experiment (CHIME). An interference fringe from a coherent gravitational
lensing signal will appear in the time-lag domain as a
statistically-significant peak in the time-lag autocorrelation function. We
calibrate our statistical significance using telescope data containing no FRB
signal. Our dataset consists of $\sim$100-ms long recordings of voltage data
from 172 FRB events, dechannelized to 1.25-ns time resolution. This coherent
search algorithm allows us to search for gravitational lensing signatures from
compact objects in the mass range of $10^{-4}-10^{4} ~\mathrm{M_{\odot}}$.
After ruling out an anomalous candidate due to diffractive scintillation, we
find no significant detections of gravitational lensing in the 172 FRB events
that have been analyzed. In a companion work [Leung, Kader+2022], we interpret
the constraints on dark matter from this search.


title:
Reflected Entropy and Entanglement Negativity for Holographic Moving
  Mirrors

abstract:
  We investigate the time evolution of reflected entropy and entanglement
negativity for mixed state configurations involving two adjacent and disjoint
intervals in the radiation flux of moving mirrors by utilizing the $AdS/BCFT$
duality. These measures are computed for the required mixed state
configurations by using the respective replica techniques in the large central
charge limit of the $BCFT_{1+1}$. We demonstrate that the results obtained
exactly agree with the corresponding holographic computations in the dual bulk
$AdS_3$ geometry with an end of the world brane. In this context, the analogues
of the Page curves for these measures are obtained for the required
configurations in the radiation flux of kink and escaping mirrors which mimic
the Hawking radiation from evaporating and eternal black holes respectively.


title: Convergence of Solutions of the BBM and BBM-KP Model Equations

abstract:
  The Benjamin-Bona-Mahony (BBM) equation has proven to be a good approximation
for the unidirectional propagation of small amplitude long waves in a channel
where the crosswise variation can be safely ignored. The
Benjamin-Bona-Mahony-Kadomtsev-Petviashvili (BBM-KP) equation is the
regularized version of the Kadomtsev-Petviashvili equation which arises in
various modeling scenarios corresponding to nonlinear dispersive waves that
propagate principally along the $x$-axis with weak dispersive effects undergone
in the direction parallel to the $y$-axis and normal to the primary direction
of propagation. There is much literature on mathematical studies regarding
these well known equations, however the relationship between the solutions of
their underlying pure initial value problems is not fully understood. In this
work, it is shown that the solution of the Cauchy problem for the BBM-KP
equation converges to the solution of the Cauchy problem for the BBM equation
in a suitable function space, provided that the initial data for both equations
are close as the transverse variable $y \rightarrow \pm \infty$.


title: Many body localization transition with correlated disorder

abstract:
  We address the critical properties of the many-body localization (MBL) phase
transition in one-dimensional systems subject to spatially correlated disorder.
We consider a general family of disorder models, parameterized by how strong
the fluctuations of the disordered couplings are when coarse-grained over a
region of size $\ell$. For uncorrelated randomness, the characteristic scale
for these fluctuations is $\sqrt{\ell}$; more generally they scale as
$\ell^\gamma$. We discuss both positively correlated disorder ($1/2 < \gamma <
1$) and anticorrelated, or "hyperuniform," disorder ($\gamma < 1/2$). We argue
that anticorrelations in the disorder are generally irrelevant at the MBL
transition. Moreover, assuming the MBL transition is described by the recently
developed renormalization-group scheme of Morningstar \emph{et al.} [Phys. Rev.
B 102, 125134, (2020)], we argue that even positively correlated disorder
leaves the critical theory unchanged, although it modifies certain properties
of the many-body localized phase.

categories: cond-mat.dis-nn cond-mat.stat-mech cond-mat.str-el quant-ph


title: Phantoms and strange attractors in cosmology

abstract:
  We study a cosmological model of gravity coupled to three, self-interacting
scalar fields, one of them with negative kinetic term. The theory has
cosmological solutions described by three-dimensional quadratic autonomous
equations, leading to strange attractors. The associated chaotic cosmologies
exhibit highly fluctuating periods of contraction and expansion, alternating
with long, steady periods in a de Sitter-like phase.


title:
Near-Equilibrium Approach to Transport in Complex Sachdev-Ye-Kitaev
  Models

abstract:
  We study the non-equilibrium dynamics of a one-dimensional complex
Sachdev-Ye-Kitaev chain by directly solving for the steady state Green's
functions in terms of small perturbations around their equilibrium values. The
model exhibits strange metal behavior without quasiparticles and features
diffusive propagation of both energy and charge. We explore the thermoelectric
transport properties of this system by imposing uniform temperature and
chemical potential gradients. We then expand the conserved charges and their
associated currents to leading order in these gradients, which we can compute
numerically and analytically for different parameter regimes. This allows us to
extract the full temperature and chemical potential dependence of the transport
coefficients. In particular, we uncover that the diffusivity matrix takes on a
simple form in various limits and leads to simplified Einstein relations. At
low temperatures, we also recover a previously known result for the
Wiedemann-Franz ratio. Furthermore, we establish a relationship between
diffusion and quantum chaos by showing that the diffusivity eigenvalues are
upper bounded by the chaos propagation rate at all temperatures. Our work
showcases an important example of an analytically tractable calculation of
transport properties in a strongly interacting quantum system and reveals a
more general purpose method for addressing strongly coupled transport.

categories: cond-mat.str-el cond-mat.dis-nn hep-th quant-ph


title: Localizing Sources of Variability in Crowded TESS Photometry

abstract:
  The Transiting Exoplanet Survey Satellite (TESS) has an exceptionally large
plate scale of 21"/px, causing most TESS light curves to record the blended
light of multiple stars. This creates a danger of misattributing variability
observed by TESS to the wrong source, which would invalidate any analysis. We
develop a method that can localize the origin of variability on the sky to
better than one fifth of a pixel. Given measured frequencies of observed
variability (e.g., from periodogram analysis), we show that the corresponding
best-fit sinusoid amplitudes to raw light curves extracted from each pixel are
distributed the same as light from the variable source. The primary assumption
of this method is that other nearby stars are not variable at the same
frequencies. Essentially, we are using the high frequency resolution of TESS to
overcome limitations from its low spatial resolution. We have implemented our
method in an open source Python package, TESS Localize
(github.com/Higgins00/TESS-Localize), that determines the location of a
variable source on the sky given TESS pixel data and a set of observed
frequencies of variability. Our method utilizes the TESS Pixel Response
Function models, and we characterize systematics in the residuals of fitting
these models to data. Given the ubiquity of source blending in TESS light
curves, verifying the source of observed variability should be a standard step
in TESS analyses.


title:
Direct Optimal Mapping for 21cm Cosmology: A Demonstration with the
  Hydrogen Epoch of Reionization Array

abstract:
  Motivated by the desire for wide-field images with well-defined statistical
properties for 21cm cosmology, we implement an optimal mapping pipeline that
computes a maximum likelihood estimator for the sky using the interferometric
measurement equation. We demonstrate this direct optimal mapping with data from
the Hydrogen Epoch of Reionization (HERA) Phase I observations. After
validating the pipeline with simulated data, we develop a maximum likelihood
figure-of-merit for comparing four sky models at 166MHz with a bandwidth of
100kHz. The HERA data agree with the GLEAM catalogs to $<$10%. After
subtracting the GLEAM point sources, the HERA data discriminate between the
different continuum sky models, providing most support for the model from Byrne
et al. 2021. We report the computation cost for mapping the HERA Phase I data
and project the computation for the HERA 320-antenna data, both are feasible
with a modern server. The algorithm is broadly applicable to other
interferometers, and is valid for wide-field and non-coplanar arrays.


title:
ALMA/ACA CO Survey of the IC 1459 and NGC 4636 Groups: Environmental
  Effects on the Molecular Gas of Group Galaxies

abstract:
  We present new results of a 12CO(J=1-0) imaging survey using the Atacama
Compact Array (ACA) for 31 HI detected galaxies in the IC 1459 and NGC 4636
groups. This is the first CO imaging survey for loose galaxy groups. We
obtained well-resolved CO data (~0.7-1.5 kpc) for a total of 16 galaxies in two
environments. By comparing our ACA CO data with the HI and UV data, we probe
the impacts of the group environment on the cold gas components (CO and HI gas)
and star formation activity. We find that CO and/or HI morphologies are
disturbed in our group members, some of which show highly asymmetric CO
distributions (e.g., IC 5264, NGC 7421, and NGC 7418). In comparison with
isolated galaxies in the xCOLD GASS sample, our group galaxies tend to have low
star formation rates and low H2 gas fractions. Our findings suggest that the
group environment can change the distribution of cold gas components, including
the molecular gas, and star formation properties of galaxies. This is
supporting evidence that pre-processing in the group-like environment can play
an important role in galaxy evolution.


title: Homological invariants of Pauli stabilizer codes

abstract:
  We study translationally invariant Pauli stabilizer codes with qudits of
arbitrary, not necessarily uniform, dimensions. Using homological methods, we
define a series of invariants called charge modules. We describe their
properties and physical meaning. The most complete results are obtained for
codes whose charge modules have Krull dimension zero. This condition is
interpreted as mobility of excitations. We show that it is always satisfied for
translation invariant 2D codes with unique ground state in infinite volume,
which was previously known only in the case of uniform, prime qudit dimension.
For codes all of whose excitations are mobile we construct a~$p$-dimensional
excitation and a $(D-p-1)$-form symmetry for every element of the $p$-th charge
module. Moreover, we define a braiding pairing between charge modules in
complementary degrees. We discuss examples which illustrate how charge modules
and braiding can be computed in practice.


title:
Model-independent constraints on decaying scalar dark matter: existing
  observations and projected radio signals at the SKA

abstract:
  We consider a decaying scalar dark matter (DM) with mass $m_\chi$ in the
range 10 GeV - 10 TeV and vary the branching ratios of all possible two-body SM
final states (excluding and including $\nu\bar{\nu}$) in the range $0\%-100\%$
to derive constraints on the total decay width $\Gamma$ by combining the data
collected by several astrophysical and cosmological observations. We find that,
$\Gamma \lesssim 10^{-26} - 10^{-27}\,{\rm s}^{-1}$ (excluding $\nu\bar{\nu}$)
and $\Gamma \lesssim 10^{-24} - 10^{-26}\,{\rm s}^{-1}$ (including
$\nu\bar{\nu}$) are allowed, depending on the values of $m_\chi$, which are
most robust upper limits on $\Gamma$ for a generic decaying scalar DM. We then
investigate the prospect of the upcoming Square Kilometer Array (SKA) radio
telescope in detecting the DM decay induced radio signals originating inside
the dwarf spheroidal (dSph) galaxies. We have classified the DM parameter
space, allowed by the existing observations, independently of the branching
ratio in each individual two-body SM final state, based on the detectability at
the SKA. Excluding the $\nu\bar{\nu}$ decay mode, we find that, throughout the
DM mass range 10 GeV - 10 TeV, $\Gamma \gtrsim 10^{-30}\,{\rm s}^{-1} -
10^{-29}\,{\rm s}^{-1}$ is detectable for all possible branching ratio
combinations at the SKA (for 100 hours of observation time), with conservative
choices for the relevant astrophysical parameters. On the other hand, when
arbitrary branching ratios are allowed also for the $\nu\bar{\nu}$ decay mode,
DM decays can be probed model-independently for $\Gamma \gtrsim 2 \times
10^{-29}\,{\rm s}^{-1}$ provided DM masses are greater than a few hundreds of
GeV.


title: Energy Complexity of Regular Language Recognition

abstract:
  The erasure of each bit of information by a computing device has an intrinsic
energy cost. Although any Turing machine can be rewritten to be
thermodynamically reversible without changing the recognized language, finite
automata that are restricted to scan their input once in "real-time" fashion
can only recognize the members of a proper subset of the class of regular
languages in this reversible manner. We use a general quantum finite automaton
model to study the thermodynamic cost per step associated with the recognition
of different regular languages. We show that zero-error quantum finite automata
have no energy cost advantage over their classical deterministic counterparts,
and prove an upper bound for the cost that holds for all regular languages. We
also demonstrate languages for which "error can be traded for energy", i.e.
whose zero-error recognition is associated with provably bigger energy cost per
step when compared to their bounded-error recognition by real-time
finite-memory quantum devices.


title: The least singular value of the general deformed Ginibre ensemble

abstract:
  We study the least singular value of the $n\times n$ matrix $H-z$ with
$H=A_0+H_0$, where $H_0$ is drawn from the complex Ginibre ensemble of matrices
with iid Gaussian entries, and $A_0$ is some general $n\times n$ matrix with
complex entries (it can be random and in this case it is independent of $H_0$).
Assuming some rather general assumptions on $A_0$, we prove an optimal tail
estimate on the least singular value in the regime where $z$ is around the
spectral edge of $H$ thus generalize the recent result of Cipolloni, Erd\H{o}s,
Schr\"{o}der arxiv:1908.01653 to the case $A_0\ne 0$. The result improves the
classical bound by Sankar, Spielman and Teng.


title: Some remarks on the Schweitzer complex

abstract:
  We prove that the Schweitzer complex is elliptic and its cohomologies define
cohomological functors. As applications, we obtain finite dimensionality, a
version of Serre duality, restrictions of the behaviour of cohomology in small
deformations, and an index formula which turns out to be equivalent to the
Hirzebruch-Riemann-Roch relations.


title: CUNI-KIT System for Simultaneous Speech Translation Task at IWSLT 2022

abstract:
  In this paper, we describe our submission to the Simultaneous Speech
Translation at IWSLT 2022. We explore strategies to utilize an offline model in
a simultaneous setting without the need to modify the original model. In our
experiments, we show that our onlinization algorithm is almost on par with the
offline setting while being 3x faster than offline in terms of latency on the
test set. We make our system publicly available.


title:
L3Cube-MahaNER: A Marathi Named Entity Recognition Dataset and BERT
  models

abstract:
  Named Entity Recognition (NER) is a basic NLP task and finds major
applications in conversational and search systems. It helps us identify key
entities in a sentence used for the downstream application. NER or similar slot
filling systems for popular languages have been heavily used in commercial
applications. In this work, we focus on Marathi, an Indian language, spoken
prominently by the people of Maharashtra state. Marathi is a low resource
language and still lacks useful NER resources. We present L3Cube-MahaNER, the
first major gold standard named entity recognition dataset in Marathi. We also
describe the manual annotation guidelines followed during the process. In the
end, we benchmark the dataset on different CNN, LSTM, and Transformer based
models like mBERT, XLM-RoBERTa, IndicBERT, MahaBERT, etc. The MahaBERT provides
the best performance among all the models. The data and models are available at
https://github.com/l3cube-pune/MarathiNLP .


title: Variable importance measures for heterogeneous causal effects

abstract:
  The conditional average treatment effect (CATE) of a binary exposure on an
outcome is often studied on the basis that personalised treatment decisions
lead to better clinical outcomes. The CATE, however, may be a complicated
function of several covariates representing patient characteristics. As such,
clinicians rely on researchers to summarise insights related to treatment
effect heterogeneity. Clinical research usually focuses on the ATE, which
averages the CATE across all patient characteristics, or considers the
treatment effect in patient strata, though strata are rarely chosen
systematically. Here we present new nonparametric treatment effect variable
importance measures (TE-VIMs). These may guide clinicians as to which patient
characteristics are important to consider when making treatment decisions, and
help researchers stratify patient populations for further study. TE-VIMs extend
recent regression-VIMs, viewed as nonparametric analogues to ANOVA statistics.
Moreover, TE-VIMs are not tied to a particular model, thus are amenable to
data-adaptive (machine learning) estimation of the CATE, itself an active area
of research. Estimators for the proposed statistics are derived from their
efficient influence curves and these are illustrated through a simulation study
and an applied example.


title: A Review on Language Models as Knowledge Bases

abstract:
  Recently, there has been a surge of interest in the NLP community on the use
of pretrained Language Models (LMs) as Knowledge Bases (KBs). Researchers have
shown that LMs trained on a sufficiently large (web) corpus will encode a
significant amount of knowledge implicitly in its parameters. The resulting LM
can be probed for different kinds of knowledge and thus acting as a KB. This
has a major advantage over traditional KBs in that this method requires no
human supervision. In this paper, we present a set of aspects that we deem a LM
should have to fully act as a KB, and review the recent literature with respect
to those aspects.


title: Evolutionary shift detection with ensemble variable selection

abstract:
  1. Abrupt environmental changes can lead to evolutionary shifts in trait
evolution. Identifying these shifts is an important step in understanding the
evolutionary history of phenotypes.
  2. We propose an ensemble variable selection method (R package ELPASO) for
the evolutionary shift detection task and compare it with existing methods (R
packages l1ou and PhylogeneticEM) under several scenarios.
  3. The performances of methods are highly dependent on the selection
criterion. When the signal sizes are small, the methods using the Bayesian
information criterion (BIC) have better performances. And when the signal sizes
are large enough, the methods using the phylogenetic Bayesian information
criterion (pBIC) (Khabbazian et al., 2016) have better performance. Moreover,
the performance is heavily impacted by measurement error and tree
reconstruction error.
  4. Ensemble method + pBIC tends to perform less conservatively than l1ou +
pBIC, and Ensemble method + BIC is more conservatively than l1ou + BIC.
PhylogeneticEM is even more conservative with small signal sizes and falls
between l1ou + pBIC and Ensemble method + BIC with large signal sizes. The
results can differ between the methods, but none clearly outperforms the
others. By applying multiple methods to a single dataset, we can access the
robustness of each detected shift, based on the agreement among methods.


title:
Text and Team: What Article Metadata Characteristics Drive Citations in
  Software Engineering?

abstract:
  Context: Citations are a key measure of scientific performance in most
fields, including software engineering. However, there is limited research that
studies which characteristics of articles' metadata (title, abstract, keywords,
and author list) are driving citations in this field. Objective: In this study,
we propose a simple theoretical model for how citations come to be with respect
to article metadata, we hypothesize theoretical linkages between metadata
characteristics and citations of articles, and we empirically test these
hypotheses. Method: We use multiple regression analyses to examine a data set
comprising the titles, abstracts, keywords, and authors of 16,131 software
engineering articles published between 1990 and 2020 in 20 highly influential
software engineering venues. Results: We find that number of authors, number of
keywords, number of question marks and dividers in the title, number of
acronyms, abstract length, abstract propositional idea density, and
corresponding authors in the core Anglosphere are significantly related to
citations. Conclusion: Various characteristics of articles' metadata are linked
to the frequency with which the corresponding articles are cited. These results
partially confirm and partially go counter to prior findings in software
engineering and other disciplines.


title: New regularity estimates for fully nonlinear elliptic equations

abstract:
  We establish new quantitative Hessian integrability estimates for viscosity
supersolutions of fully nonlinear elliptic operators. As a corollary, we show
that the optimal Hessian power integrability $\varepsilon =
\varepsilon(\lambda, \Lambda, n)$ in the celebrated $W^{2,
\varepsilon}$-regularity estimate satisfies $$\frac{ \left (1+
\frac{2}{3}\left(1- \frac{\lambda}{\Lambda} \right )\right )^{n-1}}{\ln n^4}
\cdot \left( \frac{\lambda}{\Lambda} \right) ^{n-1} \le \varepsilon \le
\frac{n\lambda}{(n-1)\Lambda +\lambda}, $$ where $n\ge 3$ is the dimension and
$0< \lambda < \Lambda$ are the ellipticity constants. In particular, $\left(
\frac{\Lambda}{\lambda} \right) ^{n-1} \varepsilon(\lambda, \Lambda, n)$
blows-up, as $n\to\infty$; previous results yielded fast decay of such a
quantity. The upper estimate improves the one obtained by Armstrong, Silvestre,
and Smart in arXiv:1103.3677


title:
Optimal Cybersecurity Investments Using SIS Model: Weakly Connected
  Networks

abstract:
  We study the problem of minimizing the (time) average security costs in large
systems comprising many interdependent subsystems, where the state evolution is
captured by a susceptible-infected-susceptible (SIS) model. The security costs
reflect security investments, economic losses and recovery costs from
infections and failures following successful attacks. However, unlike in
existing studies, we assume that the underlying dependence graph is only weakly
connected, but not strongly connected. When the dependence graph is not
strongly connected, existing approaches to computing optimal security
investments cannot be applied. Instead, we show that it is still possible to
find a good solution by perturbing the problem and establishing necessary
continuity results that then allow us to leverage the existing algorithms.


title:
Bag breakup of low viscosity drops in the presence of a continuous air
  jet

abstract:
  This work examines the breakup of a single drop of various low viscosity
fluids as it deforms in the presence of continuous horizontal air jet. Such a
fragmentation typically occurs after the bulk liquid has disintegrated upon
exiting the atomizer and is in the form of an ensemble of drops which undergo
further breakup. The drop deformation and its eventual disintegration is
important in evaluating the efficacy of a particular industrial process, be it
combustion in automobile engines or pesticide spraying in agricultural
applications. The interplay between competing influences of surface tension and
aerodynamic disruptive forces is represented by the Weber number, $We$, and
Ohnesorge number, $Oh$, and used to describe the breakup morphology. The
breakup pattern considered in our study corresponds to that of a bag attached
to a toroidal ring which occurs from $12 < We < 16$. We aim to address several
issues connected with this breakup process and their dependence on $We$ and
$Oh$ which have been hitherto unexplored. The $We$ boundary at which breakup
begins is theoretically determined and the expression obtained, $We = 12(1 +
2/3Oh^2)$, is found to match well with experimental data available in
literature. An exponential growth in the radial extent of the deformed drop and
the streamline dimension of the bag is predicted by a theoretical model and
confirmed by experimental findings. These quantities are observed to strongly
depend on $We$. However, their dependence on $Oh$ is weak.


title:
Compactness and blow up results for doubly perturbed Yamabe problems on
  manifolds with umbilic boundary

abstract:
  Given a compact Riemannian manifold with umbilic boundary, the Yamabe
boundary problem studies if there exist conformal scalar-flat metrics such that
the boundary has constant mean curvature. In this paper we address to the
stability of this problem with respect of perturbation of mean curvature of the
boundary and scalar curvature of the manifold. In particular we prove that the
Yamabe boundary problem is stable under perturbation of the mean curvature and
the scalar curvature from below, while it is not stable if one of the two
curvatures is perturbed from above.


title: Perfectly packing a cube by cubes of nearly harmonic sidelength

abstract:
  In this paper we prove that for any $1/3 < t < 1/2$, and any $n_0$ chosen
sufficiently large depending upon $t$, the cubes of sidelength $n^{-t}$ for $n
\geq n_0$ can perfectly pack a cube of volume $\sum_{n=n_0}^\infty
\frac{1}{n^{3t}}$. Our work improves upon a previously known result for when
$1/3 < t \leq 4/11 $ and $n_0 = 1$ and builds upon recent work of Terence Tao
in the two-dimensional case.


title:
Role of Oxygen Functionalities in Graphene Oxide Architectural Laminate
  Subnanometer Spacing and Water Transport

abstract:
  Active research in nanotechnology contemplates the use of nanomaterials for
engineering applications. However, a primary challenge is understanding the
effects of nanomaterial properties on industrial device performance and
translating unique nanoscale properties to the macroscale. One emerging example
is graphene oxide (GO) membranes for separation processes. Thus, here we
investigate how individual GO properties can impact layered GO characteristics
and water permeability. GO chemistry and morphology were controlled with
easy-to-implement photo-reduction and sonication techniques and were
quantitatively correlated offering a valuable tool to speed up the
characterization process. For example, one could perform chemical analysis and
concurrently obtain morphology information or vice versa. Chemical GO
modification allows for fine control of GO oxidation state and GO laminate
nanoarchitecture enabling controlled synthesis of a GO architectural laminate
(GOAL). The GOAL can be considered as the selective layer of the membrane
created by interconnected sub-nanometer channels, characterized by a length and
a height (i.e., GO spacing), through which water molecules permeate. Water
permeability was measured for eight GOAL characterized by different GO
chemistry and morphology, and indicate that GO nanochannel height dictates
water transport. The simulations indicate a no-slip Darcy-like water transport
regime inside the GOAL due to the presence of basal oxygen functionalities. The
experimental and simulation evidence presented in this letter help create a
clearer picture of water transport in GO and can be used to rationally design
more effective and efficient GO membranes.


title:
Extreme expectations of Bernoulli convolutions given their first few
  moments are attained at shifted convolutions of as few binomials

abstract:
  A result of Chebyshev (1864) and Hoeffding1956}, on bounding an expectation
of a given function with respect to a Bernoulli convolution (also called
Poisson binomial law, or law of the number of successes in independent trials)
with any given first moment, is here generalised to the case of any given first
few moments, as indicated in the title.
  A nonprobabilistic, and perhaps more obvious, reformulation is: Every
permutation invariant and separately affine-linear function of $n$ real
variables $x_i\in[a,b]$ assumes its extremal values given the power sums
$\sum_{i=1}^nx_i^1,\ldots, \sum_{i=1}^nx_i^r$ at vectors $x$ with at most $r$
coordinate values different from $a$ and $b$.


title:
Multi-modal electron microscopy study on decoherence sources and their
  stability in Nb based superconducting qubit

abstract:
  Niobium is commonly used for superconducting quantum systems as readout
resonators, capacitors, and interconnects. The coherence time of the
superconducting qubits is mainly limited by microwave dissipation attributed to
two-level system defects at interfaces, such as the Nb/Si and Nb/air interface.
One way to improve the Nb/air interface quality is by thermal annealing, as
shown by extensive studies in 3D superconducting radio frequency (SRF)
cavities. However, it is unclear how the microstructure and chemistry of the
interface structures change during heat treatment. To address this knowledge
gap, we comprehensively characterized Nb films deposited on Si wafers by
physical vapor deposition, including (1) an Nb film from a transmon and (2) an
Nb film without any patterning step, using an aberration-corrected transmission
electron microscope. Both Nb films exhibit columnar growth with strong [110]
textures. There is a double layer between the Nb film and Si substrate, which
are amorphous niobium silicides with different Nb and Si concentrations. After
in-situ heating of the heterostructure at 360{\deg}C inside the microscope, the
composition of the double layers at the Nb-Si interface remains almost the same
despite different thickness changes. The initial amorphous niobium oxide layer
on Nb surface decomposes into face-centered cubic Nb nanograins in the
amorphous Nb-O matrix upon heating.


title: Concave and other generalizations of stochastic Gronwall inequalities

abstract:
  We provide nonlinear generalizations of a class of stochastic Gronwall
inequalities that have been studied by von Renesse and Scheutzow (2010),
Scheutzow (2013), Xie and Zhang (2020) and Mehri and Scheutzow (2021). This
class of stochastic Gronwall inequalities is a useful tool for SDEs.
  More precisely, we study generalizations of the Bihari-LaSalle type. Whilst
in a closely connected article by the author convex generalizations are
studied, we investigate here concave and other generalizations. These types of
estimates are useful to obtain existence and uniqueness of global solutions of
path-dependent SDEs driven by L\'evy processes under one-sided non-Lipschitz
monotonicity and coercivity assumptions.


title:
The sparse Polynomial Chaos expansion: a fully Bayesian approach with
  joint priors on the coefficients and global selection of terms

abstract:
  Polynomial chaos expansion (PCE) is a versatile tool widely used in
uncertainty quantification and machine learning, but its successful application
depends strongly on the accuracy and reliability of the resulting PCE-based
response surface. High accuracy typically requires high polynomial degrees,
demanding many training points especially in high-dimensional problems through
the curse of dimensionality. So-called sparse PCE concepts work with a much
smaller selection of basis polynomials compared to conventional PCE approaches
and can overcome the curse of dimensionality very efficiently, but have to pay
specific attention to their strategies of choosing training points.
Furthermore, the approximation error resembles an uncertainty that most
existing PCE-based methods do not estimate. In this study, we develop and
evaluate a fully Bayesian approach to establish the PCE representation via
joint shrinkage priors and Markov chain Monte Carlo. The suggested Bayesian PCE
model directly aims to solve the two challenges named above: achieving a sparse
PCE representation and estimating uncertainty of the PCE itself. The embedded
Bayesian regularizing via the joint shrinkage prior allows using higher
polynomial degrees for given training points due to its ability to handle
underdetermined situations, where the number of considered PCE coefficients
could be much larger than the number of available training points. We also
explore multiple variable selection methods to construct sparse PCE expansions
based on the established Bayesian representations, while globally selecting the
most meaningful orthonormal polynomials given the available training data. We
demonstrate the advantages of our Bayesian PCE and the corresponding
sparsity-inducing methods on several benchmarks.


title: Imaging stars with quantum error correction

abstract:
  The development of high-resolution, large-baseline optical interferometers
would revolutionize astronomical imaging. However, classical techniques are
hindered by physical limitations including loss, noise, and the fact that the
received light is generally quantum in nature. We show how to overcome these
issues using quantum communication techniques. We present a general framework
for using quantum error correction codes for protecting and imaging starlight
received at distant telescope sites. In our scheme, the quantum state of light
is coherently captured into a non-radiative atomic state via Stimulated Raman
Adiabatic Passage, which is then imprinted into a quantum error correction
code. The code protects the signal during subsequent potentially noisy
operations necessary to extract the image parameters. We show that even a small
quantum error correction code can offer significant protection against noise.
For large codes, we find noise thresholds below which the information can be
preserved. Our scheme represents an application for near-term quantum devices
that can increase imaging resolution beyond what is feasible using classical
techniques.


title:
Performance Evaluation and Acceleration of the QTensor Quantum Circuit
  Simulator on GPUs

abstract:
  This work studies the porting and optimization of the tensor network
simulator QTensor on GPUs, with the ultimate goal of simulating quantum
circuits efficiently at scale on large GPU supercomputers. We implement NumPy,
PyTorch, and CuPy backends and benchmark the codes to find the optimal
allocation of tensor simulations to either a CPU or a GPU. We also present a
dynamic mixed backend to achieve optimal performance. To demonstrate the
performance, we simulate QAOA circuits for computing the MaxCut energy
expectation. Our method achieves $176\times$ speedup on a GPU over the NumPy
baseline on a CPU for the benchmarked QAOA circuits to solve MaxCut problem on
a 3-regular graph of size 30 with depth $p=4$.


title:
Avoiding Unintended Consequences: How Incentives Aid Information
  Provisioning in Bayesian Congestion Games

abstract:
  When users lack specific knowledge of various system parameters, their
uncertainty may lead them to make undesirable deviations in their decision
making. To alleviate this, an informed system operator may elect to signal
information to uninformed users with the hope of persuading them to take more
preferable actions. In this work, we study public and truthful signalling
mechanisms in the context of Bayesian congestion games on parallel networks. We
provide bounds on the possible benefit a signalling policy can provide with and
without the concurrent use of monetary incentives. We find that though
revealing information can reduce system cost in some settings, it can also be
detrimental and cause worse performance than not signalling at all. However, by
utilizing both signalling and incentive mechanisms, the system operator can
guarantee that revealing information does not worsen performance while offering
similar opportunities for improvement. These findings emerge from the closed
form bounds we derive on the benefit a signalling policy can provide. We
provide a numerical example which illustrates the phenomenon that revealing
more information can degrade performance when incentives are not used and
improves performance when incentives are used.


title:
Characterizations of Loxodromes on Rotational Surfaces in Euclidean
  3--Space

abstract:
  In this paper, we study on the characterizations of loxodromes on the
rotational surfaces satisfying some special geometric properties such as having
constant Gaussian curvature, flat and minimality in Euclidean 3-space. First,
we give the parametrizations of loxodromes parametrized by arc-length parameter
on any rotational surfaces in $\mathbb{E}^{3}$ and then, we calculate the
curvature and the torsion of such loxodromes. Then, we give the
parametrizations of loxodromes on rotational surfaces with constant Gaussian
curvature. In particular, we prove that the loxodrome on the flat rotational
surface is a general helix. Also, we investigate the loxodromes on the
rotational surfaces with a constant ratio of principal curvatures (CRPC
rotational surfaces). Moreover, we give the parametrizations of loxodromes on
the minimal rotational surface which is a special case of CRPC rotational
surfaces. Then, we show that the loxodrome intersects the meridians of minimal
rotational surface by the angle $\pi/{4}$ becomes an asymptotic curve. Finally,
we give some visual examples to strengthen our main results via Wolfram
Mathematica.


title: The cosmological constant vs adiabatic invariance

abstract:
  The property of adiabatic invariance is studied for the generalized potential
satisfying the condition of identity of sphere's and point mass's gravity. That
function contains a second term corresponding to the cosmological constant as
weak-field General Relativity and enables to describe the dynamics of groups
and clusters of galaxies and the Hubble tension as a result of two flows, local
and global ones. Using the adiabatic invariance approach we derive the orbital
parameters via Weierstrass functions, including the formula for the
eccentricity which explicitly reveals the differences from the Kepler problem.


title: On the Rate-Distortion-Perception Function

abstract:
  Rate-distortion-perception theory generalizes Shannon's rate-distortion
theory by introducing a constraint on the perceptual quality of the output. The
perception constraint complements the conventional distortion constraint and
aims to enforce distribution-level consistencies. In this new theory, the
information-theoretic limit is characterized by the rate-distortion-perception
function. Although a coding theorem for the rate-distortion-perception function
has recently been established, the fundamental nature of the optimal coding
schemes remains unclear, especially regarding the role of randomness in
encoding and decoding. It is shown in the present work that except for certain
extreme cases, the rate-distortion-perception function is achievable by
deterministic codes. This paper also clarifies the subtle differences between
two notions of perfect perceptual quality and explores some alternative
formulations of the perception constraint.


title:
Optimal Control with Broken Symmetry of Multi-Agent Systems on Lie
  Groups

abstract:
  In this paper we study reduction by symmetry for optimality conditions in
optimal control problems of left-invariant affine multi-agent control systems,
with partial symmetry breaking cost functions. Our approach emphasizes the role
of variational principles. Specifically, we recast the optimal control problem
as a constrained variational problem with a partial symmetry breaking
Hamiltonian and obtain the reduced optimality conditions from a reduced
variational principle via Pontryagin Maximum Principle. We apply the results to
a collision avoidance problem for multiple unicycles in the presence of an
obstacle.


title: On rearrangement inequalities for T-norm logics

abstract:
  The rearrangement inequality states that the sum of products of permutations
of 2 sequences of real numbers are maximized when the terms are similarly
ordered and minimized when the terms are ordered in opposite order. We show
that similar inequalities exists for multi-valued logic with the multiplication
and addition operation replaced with various T-norms and T-conorms
respectively.


title: Coloured Isomorphism of Classifiable C*-algebras

abstract:
  It is shown that the coloured isomorphism class of a unital, simple,
$\mathcal{Z}$-stable, separable amenable C$^*$-algebra satisfying the Universal
Coefficient Theorem (UCT) is determined by its tracial simplex.


title: On the generalized Ramanujan conjecture over function fields

abstract:
  Let $G$ be a simple group over a global function field $K$, and let $\pi$ be
a cuspidal automorphic representation of $G$. Suppose $K$ has two places $u$
and $v$ (satisfying a mild restriction on the residue field cardinality), at
which the group $G$ is quasi-split, such that $\pi_u$ is tempered and $\pi_v$
is unramified and generic. We prove that $\pi$ is tempered at all unramified
places $K_w$ at which $G$ is unramified quasi-split.
  The proof uses the Galois parametrization of cuspidal representations due to
V. Lafforgue to relate the local Satake parameters of $\pi$ to Deligne's theory
of Frobenius weights. The main observation is that, in view of the
classification of generic unitary spherical representations, due to Barbasch
and the first-named author, the theory of weights excludes generic
complementary series as possible local components of $\pi$. This in turn
determines the local Frobenius weights at all unramified places. In order to
apply this observation in practice we need a result of the second-named author
with Gan and Sawin on the weights of discrete series representations.


title: Bayes factors and posterior estimation: Two sides of the very same coin

abstract:
  Recently, several researchers have claimed that conclusions obtained from a
Bayes factor may contradict those obtained from Bayesian estimation. In this
short paper, we wish to point out that no such "incompatibility" exists if one
is willing to consistently define ones priors and posteriors. Our
recommendation is simple: If one reports a Bayes factor comparing two models,
then one should also report posterior estimates which acknowledge the
uncertainty with regards to which of the two models is correct.


title: Codescent and bicolimits of pseudo-algebras

abstract:
  We categorify cocompleteness results of monad theory, in the context of
pseudomonads. We first prove a general result establishing that, in any
2-category, weighted bicolimits can be constructed from oplax bicolimits and
bicoequalizers of codescent objects. After some prerequisites on pseudomonads
and their pseudo-algebras, we give a 2-dimensional Linton theorem reducing
bicocompleteness of 2-categories of pseudo-algebras to existence of
bicoequalizers of codescent objects. Finally we prove this condition to be
fulfilled in the case of a bifinitary pseudomonad, ensuring bicocompleteness.


title: Quantum circuit debugging and sensitivity analysis via local inversions

abstract:
  As the width and depth of quantum circuits implemented by state-of-the-art
quantum processors rapidly increase, circuit characterization via classical
simulation is becoming unfeasible. Thus, it is crucial to develop new methods
to identify significant error sources in large and complex quantum circuits. In
this work, we present a technique that identifies the layers of a circuit that
affect the circuit output the most, and thus helps to identify the most
significant sources of error. The technique requires no classical verification
of circuit output and is thus a scalable tool for debugging large quantum
programs in the form of circuits. We demonstrate the practicality and efficacy
of the proposed technique by applying it to example algorithmic circuits
implemented on IBM quantum machines.


title:
The noncommutative quantum Hall effect with anomalous magnetic moment in
  three different relativistic scenarios

abstract:
  In the present paper, we investigate the bound-state solutions of the
noncommutative quantum Hall effect (NCQHE) with anomalous magnetic moment (AMM)
in three different relativistic scenarios, namely: the Minkowski spacetime
(inertial flat case), the spinning cosmic string (CS) spacetime (inertial
curved case), and the spinning CS spacetime with noninertial effects
(noninertial curved case). In particular, in the first two scenarios, we have
an inertial frame, while in the third, we have a rotating frame. With respect
to bound-state solutions, we focus primarily on eigenfunctions (Dirac spinor
and wave function) and on energy eigenvalues (Landau levels), where we use the
flat and curved Dirac equation in polar coordinates to reach such solutions.
However, unlike the literature, here we consider a CS with an angular momentum
non-null and also the NC of the positions, and therefore, we seek a more
general description for the QHE. Once the solutions are obtained, we discuss
the influence of all parameters and physical quantities on relativistic energy
levels. Finally, we analyze the nonrelativistic limit, and we also compared our
problem with other works, where we verified that our results generalize some
particular cases of the literature.


title:
An Interaction Bulk-Boundary Relation and its Applications Towards
  Symmetry Breaking and Beyond

abstract:
  In this article, we propose a simple but general scaling relation between
interactions in a gapped bulk topological matter and gapless interacting
surface states. We explicitly illustrate such a generic bulk-boundary relation
(BBR) for a few specific interactions in a topological quantum matter, where we
can perform dimensional reduction of a microscopic bulk theory to project out
interacting surfaces. We have examined renormalization effects of the gapped
bulk fermions on the interacting topological surface fermions. As simple
applications, we utilize effective interacting quantum fields implied by BBR to
explore feasibility of routes to various fascinating emergent phenomena on
surfaces including emergent Majorana fermions induced by spontaneous symmetry
breaking. We obtain sufficient conditions for these interacting surface
phenomena to take place. We have also found that for given bulk electron-phonon
interactions and when \Omega_{D} \geq m, the phonon-mediated interactions on
surface are strongest if the bulk Debye frequency \Omega_{D} matches m, the
mass gap of the topological matter


title: A combinatorial model for the fermionic diagonal coinvariant ring

abstract:
  Let $\Theta_n = (\theta_1, \dots, \theta_n)$ and $\Xi_n = (\xi_1, \dots,
\xi_n)$ be two lists of $n$ variables and consider the diagonal action of
$\mathfrak{S}_n$ on the exterior algebra $\wedge \{ \Theta_n, \Xi_n \}$
generated by these variables. Jongwon Kim and Rhoades defined and studied the
fermionic diagonal coinvariant ring $FDR_n$ obtained from $\wedge \{ \Theta_n,
\Xi_n \}$ by modding out by the $\mathfrak{S}_n$-invariants with vanishing
constant term. In joint work with Rhoades we gave a basis for the maximal
degree components of this ring where the action of $\mathfrak{S}_n$ could be
interpreted combinatorially via noncrossing set partitions. This paper will do
similarly for the entire ring, although the combinatorial interpretation will
be limited to the action of $\mathfrak{S}_{n-1} \subset \mathfrak{S}_n$. The
basis will be indexed by a certain class of noncrossing partitions.


title:
The Carleman-based contraction principle to reconstruct the potential of
  nonlinear hyperbolic equations

abstract:
  We develop an efficient and convergent numerical method for solving the
inverse problem of determining the potential of nonlinear hyperbolic equations
from lateral Cauchy data. In our numerical method we construct a sequence of
linear Cauchy problems whose corresponding solutions converge to a function
that can be used to efficiently compute an approximate solution to the inverse
problem of interest. The convergence analysis is established by combining the
contraction principle and Carleman estimates. We numerically solve the linear
Cauchy problems using a quasi-reversibility method. Numerical examples are
presented to illustrate the efficiency of the method.


title:
Measuring Optical Extinction Towards Young Stellar Objects Using Diffuse
  Interstellar Bands

abstract:
  Line-of-sight extinction estimates to well-studied young T Tauri and Herbig
Ae/Be stars are based on many different measurements and analysis methods. This
has resulted in wide scatter among the published $A_V$ values for the same
star. In this work, we discuss the challenges in measuring extinction to
actively accreting and especially outbursting young stellar objects (YSOs), and
explore a method not previously applied to young stars, utilizing diffuse
interstellar bands (DIBs). In early-type stars, narrow correlations exist
between DIB equivalent widths and the column density of interstellar material,
and therefore the line-of-sight extinction. Here, we measure equivalent widths
of the 5780 \AA\ and 6614 \AA\ DIB features in a sample of actively accreting
YSOs, and apply established DIB--reddening calibrations to derive reddening,
and subsequently extinction. We also compare the DIBs-inferred optical
line-of-sight extinction values with previous extinction estimates for our
sample stars.


title:
Local and global topological complexity measures OF ReLU neural network
  functions

abstract:
  We apply a generalized piecewise-linear (PL) version of Morse theory due to
Grunert-Kuhnel-Rote to define and study new local and global notions of
topological complexity for fully-connected feedforward ReLU neural network
functions, F: R^n -> R. Along the way, we show how to construct, for each such
F, a canonical polytopal complex K(F) and a deformation retract of the domain
onto K(F), yielding a convenient compact model for performing calculations. We
also give a combinatorial description of local complexity for depth 2 networks,
and a construction showing that local complexity can be arbitrarily high.


title:
Sonified distance in sensory substitution does not always improve
  localization: comparison with a 2D and 3D handheld device

abstract:
  Early visual to auditory substitution devices encode 2D monocular images into
sounds while more recent devices use distance information from 3D sensors. This
study assesses whether the addition of sound-encoded distance in recent systems
helps to convey the "where" information. This is important to the design of new
sensory substitution devices. We conducted experiments for object localization
and navigation tasks with a handheld visual to audio substitution system. It
comprises 2D and 3D modes. Both encode in real-time the position of objects in
images captured by a camera. The 3D mode encodes in addition the distance
between the system and the object. Experiments have been conducted with 16
blindfolded sighted participants. For the localization, participants were
quicker to understand the scene with the 3D mode that encodes distances. On the
other hand, with the 2D only mode, they were able to compensate for the lack of
distance encoding after a small training. For the navigation, participants were
as good with the 2D only mode than with the 3D mode encoding distance.


title: Massive MIMO Beam Management in Sub-6 GHz 5G NR

abstract:
  Beam codebooks are a new feature of massive multiple-input multiple-output
(M-MIMO) in 5G new radio (NR). Codebooks comprised of beamforming vectors are
used to transmit reference signals and obtain limited channel state information
(CSI) from receivers via the codeword index. This enables large arrays that
cannot otherwise obtain sufficient CSI. The performance, however, is limited by
the codebook design. In this paper, we show that machine learning can be used
to train site-specific codebooks for initial access. We design a neural network
based on an autoencoder architecture that uses a beamspace observation in
combination with RF environment characteristics to improve the synchronization
signal (SS) burst codebook. We test our algorithm using a flexible dataset of
channels generated from QuaDRiGa. The results show that our model outperforms
the industry standard (DFT beams) and approaches the optimal performance
(perfect CSI and singular value decomposition (SVD)-based beamforming), using
only a few bits of feedback.


title:
One- and two-axis squeezing via laser coupling in an atomic
  Fermi-Hubbard model

abstract:
  We study a production of spin-squeezed states with ultra-cold atomic fermions
described by the Fermi-Hubbard model in the Mott insulating phase. We show
activation of two twisting mechanisms by a position-dependent laser coupling
between internal degrees of freedom of atoms. A single laser coupling simulates
the one-axis twisting model with the orientation of the twisting axis
determined by the coupling phase. Adding a second laser beam with a properly
chosen phase paves the way to simulate the two-axis counter-twisting model,
enabling to approach the Heisenberg-limited level of squeezing.


title:
Finding and Analyzing Crash-Consistency Bugs in Persistent-Memory File
  Systems

abstract:
  We present a study of crash-consistency bugs in persistent-memory (PM) file
systems and analyze their implications for file-system design and testing crash
consistency. We develop FlyTrap, a framework to test PM file systems for
crash-consistency bugs. FlyTrap discovered 18 new bugs across four PM file
systems; the bugs have been confirmed by developers and many have been already
fixed. The discovered bugs have serious consequences such as breaking the
atomicity of rename or making the file system unmountable. We present a
detailed study of the bugs we found and discuss some important lessons from
these observations. For instance, one of our findings is that many of the bugs
are due to logic errors, rather than errors in using flushes or fences; this
has important applications for future work on testing PM file systems. Another
key finding is that many bugs arise from attempts to improve efficiency by
performing metadata updates in-place and that recovery code that deals with
rebuilding in-DRAM state is a significant source of bugs. These observations
have important implications for designing and testing PM file systems. Our code
is available at https://github.com/utsaslab/flytrap .


title: Atomic-Void van der Waals Channel Waveguides

abstract:
  Layered van der Waals materials offer a unique platform for creating
atomic-void channels with sub-nanometer dimensions. Coupling light into these
channels may further advance sensing, quantum information, and single molecule
chemistries. Here we examine limits of light guiding in atomic-void channels
and show that van der Waals materials exhibiting strong resonances - excitonic
and polaritonic - are ideally suited for deeply subwavelength light guiding. We
demonstrate that excitonic transition metal dichalcogenides can squeeze > 70%
of optical power in just < {\lambda}/100 thick channel in the visible and
near-infrared. We also show that polariton resonances of hexagonal boron
nitride allow deeply subwavelength (< {\lambda}/500) guiding in the
mid-infrared. We further reveal effects of natural material anisotropy and
discuss the influence of losses. Our analysis shows van der Waals channel
waveguides while offering extreme optical confinement exhibit significantly
lower loss compared to plasmonic counterparts. Such atomic void waveguides pave
the way to low loss and deeply subwavelength optics.


title: Encodability Criteria for Quantum Based Systems (Technical Report)

abstract:
  This technical report contains the proofs to the lemmata and theorems of [15]
as well as some additional material. The main contributions of [15] are the
analysis of the applicability of several quality criteria for encodings within
a quantum based setting and a discussion on new, quantum specific criteria.
Therefore, an encoding from one quantum based process calculi into another is
presented and the quality criteria are applied to it. The separation result
proves the absence of an encoding the other way around.


title:
A spectral expansion for the symmetric space
  $\mathrm{GL}_n(E)/\mathrm{GL}_n(F)$

abstract:
  In this article we state and prove the spectral expansion of theta series
attached to the symmetric space $\mathrm{GL}_n(E)/\mathrm{GL}_n(F)$ where
$n\geq 1$ and $E/F$ is a quadratic extension of number fields. This is an
important step towards the fine spectral expansion of the Jacquet-Rallis trace
formula for general linear groups. To obtain our result, we extend the work of
Jacquet-Lapid-Rogawski on intertwining periods to the case of discrete
automorphic representations. The expansion we get is an absolutely convergent
integral of relative characters built upon Eisenstein series and intertwining
periods. We also establish a crucial but technical ingredient whose interest
lies beyond the focus of the article: we prove bounds for discrete Eisenstein
series on a neighborhood of the imaginary axis extending previous works of
Lapid on cuspidal Eisenstein series.


title: Reversing Food Craving Preference Through Multisensory Exposure

abstract:
  Experiencing food craving is nearly ubiquitous and has several negative
pathological impacts, but effective intervention strategies to control or
reverse craving remain limited. Food cue-reactivity tasks are often used to
study food craving but most paradigms ignore individual food preferences, which
could confound the findings. We explored the possibility of reversing food
craving preference using psychophysical tasks on human participants considering
their individual food preferences in a multisensory food exposure set-up.
Participants were grouped into Positive Control (PC), Negative Control (NC),
and Neutral Control (NEC) based on their preference for sweet and savory items.
Participants reported their momentary craving of the displayed food stimuli
through desire scale and bidding scale (willingness to pay) pre and post
multisensory exposure. Participants were exposed to food items they either
liked or disliked. Our results asserted the effect of the multisensory food
exposure showing statistically significant increase in food craving for
negative control post-exposure to disliked food items.
  Using computational model and statistical methods we also show that desire
for food does not necessarily translate to willingness to pay every time and
instantaneous subjective valuation of food craving is an important parameter
for subsequent action.
  Our results further demonstrate the role of parietal N200 and centro-parietal
P300 in reversing craving preference.