title:
Asymptotic distribution of the number of zeros in random polynomials in
  a given equivalence class over a finite field

abstract:
  Hayes equivalence is defined on monic polynomials over a finite field $\fq$
in terms of the prescribed leading coefficients and the residue classes modulo
a given monic polynomial $Q$. We study the distribution of the number of zeros
in a random polynomial over finite fields in a given Hayes' equivalence class.
It is well known that the number of distinct zeros of a random polynomial over
$\fq$ is asymptotically Poisson with mean 1. We show that this is also true for
polynomials in any given Hayes equivalence class provided that the degree of
freedom goes to infinity. Asymptotic formulas are also given for the number of
such polynomials when the degree of $Q$ and the number of prescribed leading
coefficients are small compared with the degree of the polynomial. When the
equivalence class is defined by leading coefficients only, the problem is
equivalent to the study of the distance distribution over Reed-Solomon codes
and our asymptotic formulas extend some earlier results.


title: The Path forward to N$^3$LO

abstract:
  The LHC experiments will achieve percent level precision measurements of
processes key to some of the most pressing questions of contemporary particle
physics: What is the nature of the Higgs boson? Can we successfully describe
the interaction of fundamental particles at high energies? Is there physics
beyond the Standard Model at the LHC? The capability to predict and describe
such observables at next-to-next-to-next-to-leading order (N$^3$LO) in QCD
perturbation theory is paramount to fully exploit these experimental
measurements. We describe the current status of N$^3$LO predictions and
highlight their importance in the upcoming precision phase of the LHC.
Furthermore, we identify key conceptual and mathematical developments necessary
to see wide-spread N$^3$LO phenomenology come to fruition.


title: Inorganic Scintillators for Future HEP Experiments

abstract:
  Future HEP experiments at the energy and intensity frontiers present
stringent challenges to inorganic scintillators in radiation tolerance,
ultrafast time response and cost. This paper reports recent progress in
radiation hard, ultrafast, and cost-effective inorganic scintillators for
future HEP experiments. Examples are LYSO crystals for a precision time of
flight detector, LuAG ceramics for an ultracompact, radiation hard shashlik
sampling calorimeter, BaF2:Y crystals for an ultrafast calorimeter, and
cost-effective scintillators for a homogeneous hadron calorimeter. Applications
for Gigahertz hard X-ray imaging will also be discussed.


title:
BioSimulators: a central registry of simulation engines and services for
  recommending specific tools

abstract:
  Computational models have great potential to accelerate bioscience,
bioengineering, and medicine. However, it remains challenging to reproduce and
reuse simulations, in part, because the numerous formats and methods for
simulating various subsystems and scales remain siloed by different software
tools. For example, each tool must be executed through a distinct interface. To
help investigators find and use simulation tools, we developed BioSimulators
(https://biosimulators.org), a central registry of the capabilities of
simulation tools and consistent Python, command-line, and containerized
interfaces to each version of each tool. The foundation of BioSimulators is
standards, such as CellML, SBML, SED-ML, and the COMBINE archive format, and
validation tools for simulation projects and simulation tools that ensure these
standards are used consistently. To help modelers find tools for particular
projects, we have also used the registry to develop recommendation services. We
anticipate that BioSimulators will help modelers exchange, reproduce, and
combine simulations.


title:
Fourier quasicrystals and distributions on Euclidean spaces with
  spectrum of bounded density

abstract:
  We consider temperate distributions on Euclidean spaces with uniformly
discrete support and locally finite spectrum. We find conditions on
coefficients of distributions under which they are finite sum of derivatives of
generalized lattice Dirac combs. These theorems are derived from properties of
families of discretely supported measures and almost periodic distributions.


title:
Scanning tunneling microscopy of Bi$_2$Te$_3$ films prepared by pulsed
  laser deposition: from nanocrystalline structures to van der Waals epitaxy

abstract:
  Bi$_2$Te$_3$ is a material with high efficiency of thermoelectric energy
conversion. Recently, it was also recognized as a topological insulator, and is
often used as the basis for creation of other types of topological matter.
Pulsed laser deposition (PLD) is widely considered as a simple method for
growing of multicomponent films, but not as a tool for van der Waals epitaxy.
We demonstrate here that the van der Waals epitaxy of Bi$_2$Te$_3$ is indeed
impossible in vacuum PLD, but is possible in the presence of a background gas,
which is confirmed by the results of scanning tunneling microscopy and
spectroscopy studies. Results of {\it ab initio} calculations reproduce
tunneling spectra of the first three terraces of epitaxial films of
Bi$_2$Te$_3$. In addition, an unusual hexagonal superstructure resembling a
charge-density wave is observed in overheated films.


title: Private Non-Convex Federated Learning Without a Trusted Server

abstract:
  We study differentially private (DP) federated learning (FL) with non-convex
loss functions and heterogeneous (non-i.i.d.) client data in the absence of a
trusted server, both with and without a secure "shuffler" to anonymize client
reports. We propose novel algorithms that satisfy local differential privacy
(LDP) at the client level and shuffle differential privacy (SDP) for three
classes of Lipschitz continuous loss functions: First, we consider losses
satisfying the Proximal Polyak-Lojasiewicz (PL) inequality, which is an
extension of the classical PL condition to the constrained setting. Prior works
studying DP PL optimization only consider the unconstrained problem with
Lipschitz loss functions, which rules out many interesting practical losses,
such as strongly convex, least squares, and regularized logistic regression.
However, by analyzing the proximal PL scenario, we permit such losses which are
Lipschitz on a restricted parameter domain. We propose LDP and SDP algorithms
that nearly attain the optimal strongly convex, homogeneous (i.i.d.) rates.
Second, we provide the first DP algorithms for non-convex/non-smooth loss
functions. Third, we specialize our analysis to smooth, unconstrained
non-convex FL. Our bounds improve on the state-of-the-art, even in the special
case of a single client, and match the non-private lower bound in certain
practical parameter regimes. Numerical experiments show that our algorithm
yields better accuracy than baselines for most privacy levels.


title:
Thermodynamic Limits of Photon-Multiplier Luminescent Solar
  Concentrators

abstract:
  Luminescent solar concentrators (LSCs) are theoretically able to concentrate
both direct and diffuse solar radiation with extremely high efficiencies.
Photon-multiplier luminescent solar concentrators (PM-LSCs) contain
chromophores which exceed 100\% photoluminescence quantum efficiency. PM-LSCs
have recently been experimentally demonstrated and hold promise to outcompete
traditional LSCs. However, we find that the thermodynamic limits of PM-LSCs are
different and are sometimes more extreme relative to traditional LSCs. As might
be expected, to achieve very high concentration factors a PM-LSC design must
also include a free energy change, analogous to the Stokes shift in traditional
LSCs. Notably, unlike LSCs, the maximum concentration ratio of a PM-LSC is
dependent on brightness of the incident photon field. For some brightnesses,
but equivalent energy loss, the PM-LSC has a greater maximum concentration
factor than that of the traditional LSC. We find that the thermodynamic
requirements to achieve highly concentrating PM-LSCs differ from traditional
LSCs. The new model gives insight into the limits of concentration of PM-LSCs
and may be used to extract design rules for further PM-LSC design.


title:
Instability of solitons and collapse of acoustic waves in media with
  positive dispersion

abstract:
  This article is a brief review of the results of studying the collapse of
sound waves in media with positive dispersion, which is described in terms of
the three-dimensional Kadomtsev-Petviashvili (KP) equation. The KP instability
of one-dimensional solitons in the long-wavelength limit is considered using
the expansion for the corresponding spectral problem. It is shown that the KP
instability also takes place for two-dimensional solitons in the framework of
the three-dimensional KP equation with positive dispersion. According to B.B.
Kadomtsev this instability belongs to the self-focusing type. The nonlinear
stage of this instability is a collapse. One of the collapse criteria is the
Hamiltonian unboundedness from below for a fixed momentum projection coinciding
with the $L_2$-norm. This fact follows from scaling transformations, leaving
this norm constant. For this reason, collapse can be represented as the process
of falling a particle to the center in a self-consistent unbounded potential.
It is shown that the radiation of waves from a region with a negative
Hamiltonian, due to its unboundedness from below, promotes the collapse of the
waves. This scenario was confirmed by numerical experiments
\cite{KuznetsovMusherShafarenko1983, KuznetsovMusher1986}. Two analytical
approaches to the study of collapse are presented: using the variational method
and the quasiclassical approximation. In contrast to the nonlinear
Schr\"odinger equation (NLSE) with a focusing nonlinearity, a feature of the
quasiclassical approach to describing acoustic collapse is that this method is
proposed for the three-dimensional KP equation as a system with hydrodynamic
nonlinearity. Within the framework of the quasiclassical description, a family
of self-similar collapses is found.


title:
On the $g_{z}$-Kato decomposition and generalization of Koliha Drazin
  invertibility

abstract:
  In \cite{koliha}, Koliha proved that $T\in L(X)$ ($X$ is a complex Banach
space) is generalized Drazin invertible operator equivalent to there exists an
operator $S$ commuting with $T$ such that $STS = S$ and $\sigma(T^{2}S -
T)\subset\{0\}$ which is equivalent to say that $0\not\in
\mbox{acc}\,\sigma(T).$ Later, in \cite{rwassa,rwassa1} the authors extended
the class of generalized Drazin invertible operators and they also extended the
class of pseudo-Fredholm operators introduced by Mbekhta \cite{mbekhta} and
other classes of semi-Fredholm operators. As a continuation of these works, we
introduce and study the class of $g_{z}$-invertible (resp., $g_{z}$-Kato)
operators which generalizes the class of generalized Drazin invertible
operators (resp., the class of generalized Kato-meromorphic operators
introduced by \v{Z}ivkovi\'{c}-Zlatanovi\'{c} and Duggal in \cite{rwassa2}).
Among other results, we prove that $T$ is $g_{z}$-invertible if and only if $T$
is $g_{z}$-Kato with $\tilde{p}(T)=\tilde{q}(T)<\infty$ which is equivalent to
there exists an operator $S$ commuting with $T$ such that $STS = S$ and
$\mbox{acc}\,\sigma(T^{2}S - T)\subset\{0\}$ which in turn is equivalent to say
that $0\not\in \mbox{acc}\,(\mbox{acc}\,\sigma(T)).$ As application and using
the concept of the Weak SVEP introduced at the end of this paper, we give new
characterizations of Browder-type theorems.


title: Uniform Lech's inequality

abstract:
  Let $(R,\mathfrak{m})$ be a Noetherian local ring of dimension $d\geq 2$. We
prove that if $e(\widehat{R}_{red})>1$, then the classical Lech's inequality
can be improved uniformly for all $\mathfrak{m}$-primary ideals, that is, there
exists $\varepsilon>0$ such that $e(I)\leq d!(e(R)-\varepsilon)\ell(R/I)$ for
all $\mathfrak{m}$-primary ideals $I\subseteq R$. We also obtain partial
results towards improvements of Lech's inequality when we fix the number of
generators of $I$.


title: Electrostatic solution of massless quenches in Luttinger liquids

abstract:
  The study of the non-equilibrium dynamics of many-body systems after a
quantum quench received a considerable boost and a deep theoretical
understanding from the path integral formulation in imaginary time. However,
the celebrated problem of a quench in the Luttinger parameter of a one
dimensional quantum critical system (massless quench) has so far only been
solved in the real-time Heisenberg picture. In order to bridge this theoretical
gap and to understand on the same ground massive and massless quenches, we
study the problem of a gaussian field characterized by a coupling parameter K
within a strip and a different one K0 in the remaining two semi-infinite
planes. We give a fully analytical solution using the electrostatic analogy
with the problem of a dielectric material within a strip surrounded by an
infinite medium of different dielectric constant, and exploiting the method of
charge images. After analytic continuation, this solution allows us to obtain
all the correlation functions after the quench within a path integral approach
in imaginary time, thus recovering and generalizing the results in real time.
Furthermore, this imaginary-time approach establishes a remarkable connection
between the quench and the famous problem of the conductivity of a
Tomonaga-Luttinger liquid coupled to two semi-infinite leads: the two are in
fact related by a rotation of the spacetime coordinates.


title: Effect of the modified gravity on the large scale structure formation

abstract:
  We investigate the formation of the large scale structures in the present
accelerated era in $f(R)$ gravity background. This is done by considering the
linear growth of matter perturbations at low redshift $z<1$. The effect of
$f(R)$ alters the behaviour of the matter density perturbations from the matter
dominated universe to the late-time accelerated universe which is encoded in
the Newtonian gravitational constant as $G\rightarrow G_{eff}$. The modified
gravitational constant ($G_{eff}$) depends on the form of $f(R)$. The late-time
accelerated expansion affects the formation of large scale structures by
slowing down the growth of matter density. On the other hand, $f(R)$ increases
the growth rate of the matter density perturbations. We have found that the
source term in $f(R)$ background, $G_{eff}\Omega_m$ overcomes the accelerated
expansion and the effect of accelerated expansion suppresses the formation of
the large scale structures in the asymptotic future.


title:
PMU-Driven Non-Preemptive Disconnection of Overhead Lines at the
  Approach or Break-Out of Forest Fires

abstract:
  The number and intensity of forest fires in the United States have been
steadily increasing and causing massive economic and ecological damage.
Overhead transmission and distribution lines are typically disconnected
preemptively near fires, a practice that causes high social cost. Deployment of
Phasor Measurement Units (PMUs) and their ability for synchronized real-time
measurement of voltage and current inspire the here proposed method for the
just-in-time disconnection of overhead lines at the ignition or approach of
fires. PMUs can detect ambient temperature changes caused by fires through the
change of line resistance. An ambient temperature model at the vicinity of a
fire seat and the dynamic heat exchange model of the IEEE 738 dynamic line
rating standard for bare overhead conductors are used in MATLAB Simulink to
assess the performance of the proposed control method. Extensive testing shows
that, under various conditions, the proposed technique can detect a forest fire
approaching an overhead line, while avoiding, almost completely, any false
alarms.


title: On Data Augmentation in Point Process Models Based on Thinning

abstract:
  Many models for point process data are defined through a thinning procedure
where locations of a base process (often Poisson) are either kept (observed) or
discarded (thinned) according to some probabilistic or deterministic rule. The
objective of this article is to present a universal theoretical framework that
allows the derivation of the joint distribution of thinned and observed
locations from the density of the base point process along with the formula
that describes how points are discriminated. This theory is essential in
practice when designing inference schemes based on data augmentation where
observed locations are augmented with thinned locations in order to circumvent
some intractability in the likelihood function of the marginal model. Such
schemes have been employed in the recent literature, but the absence of a
proper theoretical framework has led to conceptual flaws being introduced and
carried on in subsequent publications. This has motivated us to propose a
theoretical approach to this problem in order to avoid those pitfalls in the
future. The results described in this paper are general enough to enable future
authors in creating even more flexible models based on thinning and use the
tools described here to obtain a principled way of carrying inference.


title: Logics for Epistemic Actions: Completeness, Decidability, Expressivity

abstract:
  We consider dynamic versions of epistemic logic as formulated in Baltag and
Moss "Logics for epistemic programs" (2004). That paper proposed a logical
language (actually families of languages parameterized by action signatures)
for dynamic epistemic logic. It had been shown that validity in the language is
Pi-1-1-complete, so there are no recursively axiomatized complete logical
systems for it. In contrast, this paper proves a weak completeness result for
the fragment without action iteration, and a strong completeness result for the
fragment without action iteration and common knowledge. Our work involves a
detour into term rewriting theory. The argument uses modal filtration, and thus
we obtain the finite model property and hence decidability. We also give a
translation of our largest language into PDL, thereby obtaining a second proof
of decidability. The paper closes with some results on expressive power. These
are mostly concerned with comparing the action-iteration-free language with
modal logic augmented by transitive closure operators. We answer a natural
question about the languages we obtain by varying the action signature: we
prove that a logical language with operators for private announcements is more
expressive than one for public announcements.


title:
Comparative study of adaptive variational quantum eigensolvers for
  multi-orbital impurity models

abstract:
  We perform a systematic study of preparing ground states of correlated $e_g$
and $t_{2g}$ multi-orbital impurity models using variational quantum
eigensolvers (VQEs). Both fixed and adaptive wavefunction ans\"atze are
considered and the resulting gate depths and performance with and without
quantum sampling noise are analyzed. We investigate the qubit adaptive
derivative-assembled pseudo-trotter (ADAPT) VQE approach in the Hartree-Fock
orbital basis, as well as the Hamiltonian variational ansatz (HVA) and an
adaptive variant of it in the atomic orbital basis. An operator pool composed
of pairwise commutators of the Hamiltonian terms is developed to allow a fair
comparison between the adaptive and the fixed HVA ansatz. Using statevector
simulations, we show that the most compact ans\"atze are obtained in the atomic
orbital representation with symmetry-based Pauli tapering in parity encoding.
We further perform adaptive VQE calculations including sampling noise, and
demonstrate that high-fidelity state preparation can be achieved with the
Hamiltonian commutator pool. By utilizing a doubly decomposed form of the
impurity Hamiltonian and a noise resilient optimizer, we show that this
approach requires only a modest number of about $2^{12}$ samples per energy
evaluation. We discover a dichotomy of the operator pool complexity in the
presence of quantum noise, where a small pool size reduces the adaptive
overhead but a larger pool size accelerates the convergence to the ground
state. Finally, we measure the ground state energy of the $e_g$ model on IBM
quantum hardware using the converged qubit-ADAPT ansatz, and obtain a relative
error of 0.7\% using error mitigation techniques including symmetry-filtering
and zero-noise extrapolation.


title:
ProtagonistTagger -- a Tool for Entity Linkage of Persons in Texts from
  Various Languages and Domains

abstract:
  Named entities recognition (NER) and disambiguation (NED) can add semantic
context to the recognized named entities in texts. Named entity linkage in
texts, regardless of a domain, provides links between the entities mentioned in
unstructured texts and individual instances of real-world objects. In this
poster, we present a tool - protagonistTagger - for person NER and NED in
texts. The tool was tested on texts extracted from classic English novels and
Polish Internet news. The tool's performance (both precision and recall)
fluctuates between 78% and even 88%.


title: Feature space reduction as data preprocessing for the anomaly detection

abstract:
  In this paper, we present two pipelines in order to reduce the feature space
for anomaly detection using the One Class SVM. As a first stage of both
pipelines, we compare the performance of three convolutional autoencoders. We
use the PCA method together with t-SNE as the first pipeline and the
reconstruction errors based method as the second. Both methods have potential
for the anomaly detection, but the reconstruction error metrics prove to be
more robust for this task. We show that the convolutional autoencoder
architecture doesn't have a significant effect for this task and we prove the
potential of our approach on the real world dataset.


title: On the choice of the splitting ratio for the split likelihood ratio test

abstract:
  The recently introduced framework of universal inference provides a new
approach to constructing hypothesis tests and confidence regions that are valid
in finite samples and do not rely on any specific regularity assumptions on the
underlying statistical model. At the core of the methodology is a split
likelihood ratio statistic, which is formed under data splitting and compared
to a cleverly selected universal critical value. As this critical value can be
very conservative, it is interesting to mitigate the potential loss of power by
careful choice of the ratio according to which data are split. Motivated by
this problem, we study the split likelihood ratio test under local alternatives
and introduce the resulting class of noncentral split chi-square distributions.
We investigate the properties of this new class of distributions and use it to
numerically examine and propose an optimal choice of the data splitting ratio
for tests of composite hypotheses of different dimensions.


title:
Decontextualized I3D ConvNet for ultra-distance runners performance
  analysis at a glance

abstract:
  In May 2021, the site runnersworld.com published that participation in
ultra-distance races has increased by 1,676% in the last 23 years. Moreover,
nearly 41% of those runners participate in more than one race per year. The
development of wearable devices has undoubtedly contributed to motivating
participants by providing performance measures in real-time. However, we
believe there is room for improvement, particularly from the organizers point
of view. This work aims to determine how the runners performance can be
quantified and predicted by considering a non-invasive technique focusing on
the ultra-running scenario. In this sense, participants are captured when they
pass through a set of locations placed along the race track. Each footage is
considered an input to an I3D ConvNet to extract the participant's running gait
in our work. Furthermore, weather and illumination capture conditions or
occlusions may affect these footages due to the race staff and other runners.
To address this challenging task, we have tracked and codified the
participant's running gait at some RPs and removed the context intending to
ensure a runner-of-interest proper evaluation. The evaluation suggests that the
features extracted by an I3D ConvNet provide enough information to estimate the
participant's performance along the different race tracks.


title:
OpTiDDM (Optical Tweezers integrating Differential Dynamic Microscopy)
  maps the spatiotemporal propagation of nonlinear stresses in polymer blends
  and composites

abstract:
  How local stresses propagate through polymeric fluids, and, more generally,
how macromolecular dynamics give rise to viscoelasticity are open questions
vital to wide-ranging scientific and industrial fields. Here, to unambiguously
connect polymer dynamics to force response, and map stress propagation in
macromolecular materials, we present a powerful approach-Optical Tweezers
integrating Differential Dynamic Microscopy (OpTiDMM)-that simultaneously
imposes local strains, measures resistive forces, and analyzes the motion of
the surrounding polymers. Our measurements with blends of ring and linear
polymers (DNA) and their composites with stiff polymers (microtubules) uncover
a surprising resonant response, in which affine alignment, superdiffusivity,
and elastic memory are maximized when the strain rate is comparable to the
entanglement rate. Microtubules suppress this resonance, while substantially
increasing elastic force and memory, due to varying degrees to which the
polymers buildup, stretch and flow along the strain path, and configurationally
dissipate stress. More broadly, the rich multi-scale coupling of mechanics and
dynamics afforded by OpTiDDM, empowers its interdisciplinary use to elucidate
non-trivial phenomena that sculpt stress propagation dynamics-critical to
commercial applications and cell mechanics alike.


title:
First Experiences in Performance Benchmarking with the New SPEChpc 2021
  Suites

abstract:
  Modern HPC systems are built with innovative system architectures and novel
programming models to further push the speed limit of computing. The increased
complexity poses challenges for performance portability and performance
evaluation. The Standard Performance Evaluation Corporation -SPEC has a long
history of producing industry standard benchmarks for modern computer systems.
SPEC is a newly released SPEChpc 2021 benchmark suites, developed by the High
Performance Group, are a bold attempt to provide a fair and objective
benchmarking tool designed for state of the art HPC systems. With the support
of multiple host and accelerator programming models, the suites are portable
across both homogeneous and heterogeneous architectures. Different workloads
are developed to fit system sizes ranging from a few compute nodes to a few
hundred compute nodes. In this manuscript, we take a first glance at these
benchmark suites and evaluate their portability and basic performance
characteristics on various popular and emerging HPC architectures, including
x86 CPU, NVIDIA GPU, and AMD GPU. This study provides a first-hand experience
of executing the SPEChpc 2021 suites at scale on production HPC systems,
discusses real-world use cases, and serves as an initial guideline for using
the benchmark suites.


title:
Nb3Sn Superconducting Radiofrequency Cavities: a Maturing Technology for
  Particle Accelerators and Detectors

abstract:
  Nb3Sn superconducting radiofrequency (SRF) cavities have substantial
potential for enabling new performance capabilities for particle accelerators
for high energy physics (HEP), as well as for RF cavity-based detectors for
dark matter, gravitational waves, and other quantum sensing applications.
Outside of HEP, Nb3Sn SRF cavities can also benefit accelerators for nuclear
physics, basic energy sciences, and the industry. In this contribution to
Snowmass 2021, we overview the potential, status, and outlook of Nb3Sn SRF
cavities.


title: A Machine Learning Enhanced Algorithm for the Optimal Landing Problem

abstract:
  We propose a machine learning enhanced algorithm for solving the optimal
landing problem. Using Pontryagin's minimum principle, we derive a two-point
boundary value problem for the landing problem. The proposed algorithm uses
deep learning to predict the optimal landing time and a space-marching
technique to provide good initial guesses for the boundary value problem
solver. The performance of the proposed method is studied using the quadrotor
example, a reasonably high dimensional and strongly nonlinear system. Drastic
improvement in reliability and efficiency is observed.


title:
Two-photon Annihilation of Positrons with K-shell Electrons of H-like
  ions

abstract:
  The two-photon annihilation of a positron with an electron bound in the 1s
state of a H-like ion is calculated within the fully relativistic QED
framework. The interaction with the nucleus is treated nonperturbatively, thus
allowing the calculations to be carried out for the annihilation with
strongly-bound inner shells of heavy ions. Infrared divergences, appearing when
one of the emitted photons approaches the low-frequency limit, are accurately
eliminated from final expressions. The total cross section of the two-photon
and one-photon annihilation processes are compared for a wide range of
collision energies and nuclear charge numbers. It is demonstrated that the
two-photon annihilation channel dominates over the one-photon channel for the
low and medium-Z ions, whereas for the high-Z ions the situation reverses.


title:
Watching the Clocks: Interpreting the Page-Wootters Formalism and the
  Internal Quantum Reference Frame Programme

abstract:
  We discuss some difficulties that arise in attempting to interpret the
Page-Wootters and Internal Quantum Reference Frames formalisms, then use a
'final measurement' approach to demonstrate that there is a workable
single-world realist interpretation for these formalisms. We note that it is
necessary to adopt some interpretation before we can determine if the
'reference frames' invoked in these approaches are operationally meaningful,
and we argue that without a clear operational interpretation, such reference
frames might not be suitable to define an equivalence principle. We argue that
the notion of superposition should take into account the way in which an
instantaneous state is embedded in ongoing dynamical evolution, and this leads
to a more nuanced way of thinking about the relativity of superposition in
these approaches. We conclude that typically the operational content of these
approaches appears only in the limit as the size of at least one reference
system becomes large, and therefore these formalisms have an important role to
play in showing how our macroscopic reference frames can emerge out of wholly
relational facts.


title:
Drag-induced dynamical formation of dark solitons in Bose mixture on a
  ring

abstract:
  Solitons occur in a wide array of fields ranging from tsunami waves and
fiber-optic communication to biological systems. A rich research field recently
emerged in binary ultracold atomic systems where nontrivial soliton dynamics
occurs due to inter-component density-density interaction. In this work we show
different kind of nontrivial soliton dynamics arising due to current-current
coupling between components (Andreev-Bashkin drag), such as a drag-induced dark
soliton generation.


title:
Newcomers and suburbanites can drive the evolution of the size-stellar
  mass relation of early type galaxies in galaxy clusters

abstract:
  At fixed stellar mass $M_*$, the effective radius $R_{\rm e}$ of massive
satellite early-type galaxies (ETGs) in galaxy clusters is, on average, larger
at lower redshift. We study theoretically this size evolution using the
state-of-the-art cosmological simulation IllustrisTNG100: we sampled $75$
simulated satellite ETGs at redshift $z=0$ with $M_* \ge 10^{10.4} M_{\odot}$
belonging to the two most massive ($\approx 10^{14.6} M_{\odot} $) haloes of
the simulation. We traced back in time the two clusters' main progenitors and
we selected their satellite ETGs at $z>0$ with the same criterion adopted at
$z=0$. The $R_{\rm e}-M_*$ relation of the simulated cluster satellite ETGs,
which is robustly measured out to $z=0.85$, evolves similarly to the observed
relation over the redshift range $0\lesssim z \lesssim 0.85$. In the simulation
the main drivers of this evolution are the acquisition of new galaxies
("newcomers") by the clusters and the transformation of member galaxies located
at large clustercentric distance ("suburbanites") at $z=0.85$, which end up
being massive satellite ETGs at $z=0$. Though several physical processes
contribute to change the population of satellite ETGs in the considered
redshift interval, the shape of the stellar mass function of the simulated
cluster ETGs is not significantly different at $z=0.85$ and at $z=0$,
consistent with observations.


title:
Nuclei with enhanced Schiff moments in practical elements for atomic and
  molecular EDM measurements

abstract:
  This is a resource paper concerning enhancement of observable time-reversal
breaking effects by nuclear structure, aimed at AMO experimentalists. It's
intended to support a white paper by providing some orientation on what can be
said about some particular isotopes. Any conclusions are qualitative, and the
reader should consult and cite the primary references and reviews rather than
this arXiv alone.


title:
Adaptive Gap Entangled Polynomial Coding for Multi-Party Computation at
  the Edge

abstract:
  Multi-party computation (MPC) is promising for designing privacy-preserving
machine learning algorithms at edge networks. An emerging approach is coded-MPC
(CMPC), which advocates the use of coded computation to improve the performance
of MPC in terms of the required number of workers involved in computations. The
current approach for designing CMPC algorithms is to merely combine efficient
coded computation constructions with MPC. Instead, we propose a new
construction; Adaptive Gap Entangled polynomial (AGE) codes, where the degrees
of polynomials used in computations are optimized for MPC. We show that MPC
with AGE codes (AGE-CMPC) performs better than existing CMPC algorithms in
terms of the required number of workers as well as storage, communication and
computation load.


title:
CMKD: CNN/Transformer-Based Cross-Model Knowledge Distillation for Audio
  Classification

abstract:
  Audio classification is an active research area with a wide range of
applications. Over the past decade, convolutional neural networks (CNNs) have
been the de-facto standard building block for end-to-end audio classification
models. Recently, neural networks based solely on self-attention mechanisms
such as the Audio Spectrogram Transformer (AST) have been shown to outperform
CNNs. In this paper, we find an intriguing interaction between the two very
different models - CNN and AST models are good teachers for each other. When we
use either of them as the teacher and train the other model as the student via
knowledge distillation (KD), the performance of the student model noticeably
improves, and in many cases, is better than the teacher model. In our
experiments with this CNN/Transformer Cross-Model Knowledge Distillation (CMKD)
method we achieve new state-of-the-art performance on FSD50K, AudioSet, and
ESC-50.


title:
Second-Harmonic Generation Enhancement by Film-Coupled Plasmonic
  Nanopatch Antennas With Integrated Quantum Emitters

abstract:
  Plasmonic nanocavities have proven to be a powerful optical platform for
confining light at a length scale much smaller than the diffraction limit.
Enhanced electromagnetic fields within the cavity mode volume enable multiple
significant effects that lead to applications in both the linear and nonlinear
optical regimes. In this work, we demonstrate enhanced second harmonic
generation from individual plasmonic nanopatch antennas which are formed by
separating silver nanocubes from a smooth gold film using a sub-10 nm zinc
oxide spacer layer. When the nanopatch antennas are excited at their
fundamental plasmon frequency, a 10^4-fold increase in the intensity of the
second harmonic generation wave is observed. Moreover, by integrating quantum
emitters that have an absorption energy at the fundamental frequency, a second
order nonlinear exciton-polariton strong coupling response is observed with a
Rabi splitting energy of 19 meV. The nonlinear frequency conversion using
nanopatch antennas thus provides an excellent platform for nonlinear control of
the light-matter interactions in both weak and strong coupling regimes which
will have a great potential for applications in optical engineering and
information processing.


title:
The development of battery storage systems in Germany: A market review
  (status 2022)

abstract:
  With this update of our previous publications, we publish the latest data of
the market development of battery storage systems (BSS) in Germany, one of the
leading storage markets worldwide. For the analyses of both stationary and
mobile storage markets, we use the public registrations of the German Federal
Network Agency and the Federal Motor Transport Authority, our own databases
from the monitoring of subsidy programs, and bilateral exchange with large
companies. In comparison to 2020, the market for home storage systems (HSS)
grew by 50% in terms of battery energy in 2021 and is by far the largest
stationary storage market in Germany. We estimate that about 145,000 HSS (1.27
GWh / 0.73 GW) were installed solely in 2021. The average specific price for a
medium-sized HSS was about 1,000 EUR/kWh in 2021, showing a price decrease of
8% from 2020 to 2021. The emerging market for industrial storage systems (ISS)
grew by 15% in 2021, with a total of 900 ISS (0.06 GWh / 0.03 GW) installed,
although industrial PV installations decreased. The market growth for
large-scale storage systems (LSS) remains on a relatively low level with 11 LSS
(0.03 GWh / 0.04 GW) commissioned. The market for battery electric vehicles
(EV) doubled in 2021 and new registrations raised to 680,000 EV (22.45 GWh /
31.18 GW). The public charging infrastructure could not follow this growth and
grew linearly with about 11,700 new installations to 50,000 charging points,
most of which are up to 22 kW. The number of EV per charging point grew from 10
in 2018 to 25 in 2021. In total, we estimate that over 430,000 stationary BSS
with a battery energy of 4.46 GWh and a power of 2.64 GW and 1,270,000 EV with
a battery energy of 39.59 GWh, a DC charging power of 51.84 GW, and an AC
charging power of 7.71 GW were operated in Germany by the end of 2021.


title:
Effects of finite non-gaussianity on evolution of a random wind wave
  field

abstract:
  We examine long-term evolution of a random wind wave field generated by
constant forcing, by comparing numerical simulations of the kinetic equation
and direct numerical simulations (DNS) of the dynamical equations. While
integral characteristics of spectra are in reasonably good agreement, the
spectral shapes differ considerably at large times, the DNS spectral shape
being in much better agreement with field observations. Varying the number of
resonant and approximately resonant wave interactions in the DNS numerical
scheme, we show that when the ratio of nonlinear and linear parts of the
Hamiltonian tends to zero, the DNS spectral shape approaches the shape
predicted by the kinetic equation. We attribute the discrepancies between the
kinetic equation modelling, on one side, and the DNS and observations, on the
other, to the neglect of non-gaussianity in the derivation of the kinetic
equation.


title:
TurbuGAN: An Adversarial Learning Approach to Spatially-Varying
  Multiframe Blind Deconvolution with Applications to Imaging Through
  Turbulence

abstract:
  We present a self-supervised and self-calibrating multi-shot approach to
imaging through atmospheric turbulence, called TurbuGAN. Our approach requires
no paired training data, adapts itself to the distribution of the turbulence,
leverages domain-specific data priors, outperforms existing approaches, and can
generalize from tens to tens of thousands of measurements. We achieve such
functionality through an adversarial sensing framework adapted from CryoGAN,
which uses a discriminator network to match the distributions of captured and
simulated measurements. Our framework builds on CryoGAN by (1) generalizing the
forward measurement model to incorporate physically accurate and
computationally efficient models for light propagation through anisoplanatic
turbulence, (2) enabling adaptation to slightly misspecified forward models,
and (3) leveraging domain-specific prior knowledge using pretrained generative
networks, when available. We validate TurbuGAN in simulation using realistic
models for atmospheric turbulence-induced distortion.


title:
On the analysis of optimization with fixed-rank matrices: a quotient
  geometric view

abstract:
  We study a type of Riemannian gradient descent (RGD) algorithm, designed
through Riemannian preconditioning, for optimization on $\mathcal{M}_k^{m\times
n}$ -- the set of $m\times n$ real matrices with a fixed rank $k$. Our analysis
is based on a quotient geometric view of $\mathcal{M}_k^{m\times n}$: by
identifying this set with the quotient manifold of a two-term product space
$\mathbb{R}_*^{m\times k}\times \mathbb{R}_*^{n\times k}$ of matrices with full
column rank via matrix factorization, we find an explicit form for the update
rule of the RGD algorithm, which leads to a novel approach to analysing their
convergence behavior in rank-constrained optimization. We then deduce some
interesting properties that reflect how RGD distinguishes from other matrix
factorization algorithms such as those based on the Euclidean geometry. In
particular, we show that the RGD algorithm are not only faster than Euclidean
gradient descent but also do not rely on the balancing technique to ensure its
efficiency while the latter does. Starting from the novel results, we further
show that this RGD algorithm is guaranteed to solve matrix sensing and matrix
completion problems with linear convergence rate, under mild conditions related
to the restricted positive definiteness property. Numerical experiments on
matrix sensing and completion are provided to demonstrate these properties.


title: On the $d$-Claw Vertex Deletion Problem

abstract:
  Let $d$-claw (or $d$-star) stand for $K_{1,d}$, the complete bipartite graph
with 1 and $d\ge 1$ vertices on each part. The $d$-claw vertex deletion
problem, $d$-CLAW-VD, asks for a given graph $G$ and an integer $k$ if one can
delete at most $k$ vertices from $G$ such that the resulting graph has no
$d$-claw as an induced subgraph. Thus, 1-CLAW-VD and 2-CLAW-VD are just the
famous VERTEX COVER problem and the CLUSTER VERTEX DELETION problem,
respectively. In this paper, we strengthen a hardness result in [M. Yannakakis,
Node-Deletion Problems on Bipartite Graphs, SIAM J. Comput. (1981)], by showing
that CLUSTER VERTEX DELETION remains NP-complete when restricted to bipartite
graphs of maximum degree 3. Moreover, for every $d\ge 3$, we show that
$d$-CLAW-VD is NP-complete even when restricted to bipartite graphs of maximum
degree $d$. These hardness results are optimal with respect to degree
constraint. By extending the hardness result in [F. Bonomo-Braberman et al.,
Linear-Time Algorithms for Eliminating Claws in Graphs, COCOON 2020], we show
that, for every $d\ge 3$, $d$-CLAW-VD is NP-complete even when restricted to
split graphs without $(d+1)$-claws, and split graphs of diameter 2. On the
positive side, we prove that $d$-CLAW-VD is polynomially solvable on what we
call $d$-block graphs, a class properly contains all block graphs. This result
extends the polynomial-time algorithm in [Y. Cao et al., Vertex deletion
problems on chordal graphs, Theor. Comput. Sci. (2018)] for 2-CLAW-VD on block
graphs to $d$-CLAW-VD for all $d\ge 2$ and improves the polynomial-time
algorithm proposed by F. Bonomo-Brabeman et al. for (unweighted) 3-CLAW-VD on
block graphs to 3-block graphs.


title:
Reconstruction of the quintessence dark energy potential from a Gaussian
  process

abstract:
  The quintessence dark energy potential is reconstructed in a
model-independent way. Reconstruction relies on a Gaussian process and on
available expansion-rate data. Specifically, 40-point values of $H(z)$ are
used, consisting of a 30-point sample deduced from a differential age method
and an additional 10-point sample obtained from the radial BAO method. Results
are obtained for two kernel functions and for three different values of
$H_{0}$. They shed light on the $H_{0}$ tension problem for a universe
described with quintessence dark energy. They are also a clear indication that
the tension has to do with the physical understanding of the issue, rather than
being just a numerical problem with statistics. Moreover, the model-independent
reconstruction of the potential here obtained can serve as a reference to
constraint available models and it can be also used as a reference frame to
construct new ones. Various possibilities, including $V(\phi) \sim e^{-\lambda
\phi}$, are compared with the reconstructions here obtained, which is notably
the first truly model independent reconstruction of the quintessence dark
energy potential. This allows to select new models that can be interesting for
cosmology. The method can be extended to reconstruct the potential of related
dark energy models, to be considered in future work.


title: Algorithmic Recourse in the Face of Noisy Human Responses

abstract:
  As machine learning (ML) models are increasingly being deployed in
high-stakes applications, there has been growing interest in providing recourse
to individuals adversely impacted by model predictions (e.g., an applicant
whose loan has been denied). To this end, several post hoc techniques have been
proposed in recent literature. These techniques generate recourses under the
assumption that the affected individuals will implement the prescribed
recourses exactly. However, recent studies suggest that individuals often
implement recourses in a noisy and inconsistent manner - e.g., raising their
salary by \$505 if the prescribed recourse suggested an increase of \$500.
Motivated by this, we introduce and study the problem of recourse invalidation
in the face of noisy human responses. More specifically, we theoretically and
empirically analyze the behavior of state-of-the-art algorithms, and
demonstrate that the recourses generated by these algorithms are very likely to
be invalidated if small changes are made to them. We further propose a novel
framework, EXPECTing noisy responses (EXPECT), which addresses the
aforementioned problem by explicitly minimizing the probability of recourse
invalidation in the face of noisy responses. Experimental evaluation with
multiple real world datasets demonstrates the efficacy of the proposed
framework, and supports our theoretical findings


title:
Colossal transverse magnetoresistance due to nematic superconducting
  phase fluctuations in a copper oxide

abstract:
  Electronic anisotropy (or `nematicity') has been detected in all main
families of cuprate superconductors by a range of experimental techniques --
electronic Raman scattering, THz dichroism, thermal conductivity, torque
magnetometry, second-harmonic generation -- and was directly visualized by
scanning tunneling microscope (STM) spectroscopy. Using angle-resolved
transverse resistance (ARTR) measurements, a very sensitive and background-free
technique that can detect 0.5$\%$ anisotropy in transport, we have observed it
also in La$_{2-x}$Sr$_{x}$CuO$_{4}$ (LSCO) for $0.02 \leq x \leq 0.25$.
Arguably the key enigma in LSCO is the rotation of the nematic director with
temperature; this has not been seen before in any material. Here, we address
this puzzle by measuring the angle-resolved transverse magnetoresistance
(ARTMR) in LSCO. We report a discovery of colossal transverse magnetoresistance
(CTMR) -- an order-of-magnitude drop in the transverse resistivity in the
magnetic field of $6\,$T, while none is seen in the longitudinal resistivity.
We show that the apparent rotation of the nematic director is caused by
superconducting phase fluctuations, which are much more anisotropic than the
normal-electron fluid, and their respective directors are not parallel. This
qualitative conclusion is robust and follows straight from the raw experimental
data. We quantify this by modelling the measured (magneto-)conductivity by a
sum of two conducting channels that correspond to distinct anisotropic Drude
and Cooper-pair effective mass tensors. Strikingly, the anisotropy of
Cooper-pair stiffness is significantly larger than that of the normal
electrons, and it grows dramatically on the underdoped side, where the
fluctuations become effectively quasi-one dimensional.


title: Bounding cohomology classes over semiglobal fields

abstract:
  We provide a uniform bound for the index of cohomology classes in $H^i(F,
\mu_\ell^{\otimes i-1})$ when $F$ is a semiglobal field (i.e., a one-variable
function field over a complete discretely valued field $K$). The bound is given
in terms of the analogous data for the residue field of $K$ and its finitely
generated extensions of transcendence degree at most one. We also obtain
analogous bounds for collections of cohomology classes. Our results provide
recursive formulas for function fields over higher rank complete discretely
valued fields, and explicit bounds in some cases when the information on the
residue field is known.


title: Theoretical developments in the SMEFT at dimension-8 and beyond

abstract:
  In this contribution to the Snowmass 2021 process we review theoretical
developments in the Standard Model Effective Field Theory (SMEFT) with a focus
on effects at the dimension-8 level and beyond. We review the theoretical
advances that led to the complete construction of the operator bases for the
dimension-8 and dimension-9 SMEFT Lagrangians. We discuss the possibility of
obtaining all-orders results in the $1/\Lambda$ expansion for certain SMEFT
observables as well as the current status of renormalization group running and
implications for positivity, and briefly present the on-shell approach to
constructing SMEFT amplitudes. Finally we present several new phenomenological
effects that first arise at dimension-8 and discuss the impact of these terms
on experimental analyses.


title:
On a version of a multivariate integration by parts formula for Lebesgue
  integrals

abstract:
  Multidimensional integration by parts formulas are valid under the standard
assumption that one of the functions is continuous and the other has bounded
Hardy-Krause variation. Motivated by several recently developed results in the
probabilistic context of price and risk bounds, we provide a version of an
integration by parts formula for Lebesgue integrals on a possibly unbounded
domain where a componentwise left-/right-continuous and measure inducing
function is integrated with respect to the signed measure induced by a measure
inducing, componentwise right-/left-continuous, bounded, and grounded function.
For this purpose, we extensively analyze measure inducing functions and
characterize them in terms of Delta-monotone functions. We provide, as a
consequence of the integration by parts formula, several convergence results
which allow an extension of the Lebesgue integral of a measure inducing
function to the case that one integrates with respect to a Lipschitz-continuous
semi-copula.


title: Strategies for Beam-Induced Background Reduction at Muon Colliders

abstract:
  This Snowmass study explores methods for the reduction of Beam-Induced
Backgrounds (BIB) at a future muon collider. Studies are performed for a
collision energy of 1.5 TeV, and a detector with a tungsten nozzle designed to
block the majority of the BIB. In this context, detector strategies are
explored to further reduce the BIB, with a focus on the innermost layers of the
tracker where its density is highest. In addition, a conceptual design of a
calorimeter built to reject BIB is presented.


title: Superentropic Black Hole Shadows in Arbitrary Dimensions

abstract:
  We investigate the shadow behaviors of the superentropic black holes in
arbitrary dimensions. Using the Hamilton-Jacobi mechanism, we first obtain the
associated null geodesic equations of motion. By help of a spheric
stereographic projection, we discuss the shadows in terms of one-dimensional
real curves. Fixing the mass parameter $m$, we obtain certain shapes being
remarkably different than four dimensional geometric configurations. We then
study theirs behaviors by varying the black hole mass parameter. We show that
the shadows undergo certain geometric transitions depending on the spacetime
dimension. In terms of a critical value $m_c$, we find that the four
dimensional shadows exhibit three configurations being the D-shape, the
cardioid and the naked singularity associated with m>m_c, m=m_c and m<m_c,
respectively. We reveal that the D-shape passes to the naked singularity via a
critical curve called cardioid. In higher dimensions, however, we show that
such transitional behaviors are removed.


title:
Induced subgraphs and tree decompositions IV. (Even hole, diamond,
  pyramid)-free graphs

abstract:
  A hole in a graph $G$ is an induced cycle of length at least four, and an
even hole is a hole of even length. The diamond is the graph obtained from the
complete graph $K_4$ by removing an edge. A pyramid is a graph consisting of a
triangle called the base, a vertex called the apex, and three internally
disjoint paths starting at the apex and disjoint otherwise, each joining the
apex to a vertex of the base. For a family $\mathcal{H}$ of graphs, we say a
graph $G$ is $\mathcal{H}$-free if no induced subgraph of $G$ is isomorphic to
a member of $\mathcal{H}$. Cameron, da Silva, Huang, and Vu\v{s}kovi\'c proved
that (even hole, triangle)-free graphs have treewidth at most five, which
motivates studying the treewidth of even-hole-free graphs of larger clique
number. Sintiari and Trotignon provided a construction of (even hole,
$K_4$)-free graphs of arbitrarily large treewidth, and observing induced
diamonds all over their construction, they conjectured that (even hole,
diamond, $K_4$)-free graphs have bounded treewidth. We approach this conjecture
by showing that for every $t$, (even hole, pyramid, diamond, $K_t$)-free graphs
have bounded treewidth. Our main result is in fact more general, that treewidth
is bounded in graphs excluding certain wheels and three-path-configurations,
diamonds, and a fixed complete graph. The proof uses "non-crossing
decompositions" methods similar to those in previous papers in this series. In
previous papers, however, bounded degree was a necessary condition to prove
bounded treewidth. The result of this paper is the first to use the method of
"non-crossing decompositions" to prove bounded treewidth in a graph class of
unbounded maximum degree.


title: New approach to DM searches with mono-photon signature

abstract:
  High energy e$^+$e$^-$ colliders offer unique possibility for the most
general dark matter search based on the mono-photon signature. Analysis of the
energy spectrum and angular distributions of photons from the initial state
radiation can be used to search for hard processes with invisible final state
production. Most studies in the past focused on scenarios assuming heavy
mediator exchange. We notice however, that scenarios with light mediator
exchange are still not excluded by existing experimental data, if the mediator
coupling to Standard Model particles is very small. We proposed a novel
approach, where the experimental sensitivity to light mediator production is
defined in terms of both the mediator mass and mediator width. This approach is
more model independent than the approach assuming given mediator coupling
values to SM and DM particles. Summarised in this contribution are published
results of our studies concerning simulation of mono-photon events with WHIZARD
and the expected sensitivity of the International Linear Collider (ILC) and
Compact Linear Collider (CLIC) experiments to dark matter production.


title: Grid: OneCode and FourAPIs

abstract:
  We discuss a substantial update to the Grid software library for Lattice QCD,
enabling it to port to multiple GPU architectures while retaining CPU
vectorisation and SIMD execution within OpenMP threads. The GPU environments
supported include vendor specific Nvidia CUDA and AMD HIP environments and a
(mostly) standards based SYCL implementation. This is performed by an internal
abstraction interface giving single source cross-platform performance
portability across all number of planned Exascale architectures, and all those
planned by the US Department of Energy.


title: Pruned Graph Neural Network for Short Story Ordering

abstract:
  Text coherence is a fundamental problem in natural language generation and
understanding. Organizing sentences into an order that maximizes coherence is
known as sentence ordering. This paper is proposing a new approach based on the
graph neural network approach to encode a set of sentences and learn orderings
of short stories. We propose a new method for constructing sentence-entity
graphs of short stories to create the edges between sentences and reduce noise
in our graph by replacing the pronouns with their referring entities. We
improve the sentence ordering by introducing an aggregation method based on
majority voting of state-of-the-art methods and our proposed one. Our approach
employs a BERT-based model to learn semantic representations of the sentences.
The results demonstrate that the proposed method significantly outperforms
existing baselines on a corpus of short stories with a new state-of-the-art
performance in terms of Perfect Match Ratio (PMR) and Kendall's Tau (Tau)
metrics. More precisely, our method increases PMR and Tau criteria by more than
5% and 4.3%, respectively. These outcomes highlight the benefit of forming the
edges between sentences based on their cosine similarity. We also observe that
replacing pronouns with their referring entities effectively encodes sentences
in sentence-entity graphs.


title:
Effects of XX-catalysts on quantum annealing spectra with perturbative
  crossings

abstract:
  The efficiency of Adiabatic Quantum Annealing is limited by the scaling with
system size of the minimum gap that appears between the ground and first
excited state in the annealing energy spectrum. In general the algorithm is
unable to find the solution to an optimisation problem in polynomial time due
to the presence of avoided level crossings at which the gap size closes
exponentially with system size. One promising avenue being explored to produce
more favourable gap scaling is the introduction of non-stoquastic XX-couplings
in the form of a catalyst - of particular interest are catalysts which utilise
accessible information about the optimisation problem in their construction.
Here we show extreme sensitivity of the effect of an XX-catalyst to subtle
changes in the encoding of the optimisation problem. We observe that catalysts
designed to enhance the minimum gap at an avoided level crossing can, under
certain conditions, result in closing gaps in the spectrum. To understand the
origin of these closing gaps, we study how the evolution of the ground state
vector is altered by the presence of the catalyst. We find that the negative
components of the ground state vector are key to understanding the response of
the gap spectrum. In particular the closing gaps correspond to changes in which
vector components become negative over the course of the evolution. We also
consider how and when these closing gaps could be utilised in diabatic quantum
annealing protocols - a promising alternative to adiabatic quantum annealing in
which transitions to higher energy levels are exploited to reduce the run time
of the algorithm.


title: Bridging the Gap: Spectral Distortions meet Gravitational Waves

abstract:
  This talk has the goal of introducing two upcoming exciting avenues of
discovery in precision Cosmology: spectral distortions (SDs) and gravitational
waves (GWs). The former signals offer a clear window into the state of the
primordial plasma at times prior to recombination, and thus sheds light on
small-scale primordial perturbations, dark matter decay and black hole
formation to just mention a few scenarios. The latter signals, which are
already offering new insights into the landscape of black hole and neutron star
mergers, will reveal intricate dynamics of the early universe including
primordial black holes, inflationary potentials, and even reheating dynamics.
An elegant link is drawn between these two future observations since primordial
GW backgrounds will source SDs, a coupling which offers unique insight to over
six decades of GW frequencies. More importantly the SD visibility window
bridges the gap between astrophysical high- and cosmological low-frequency
measurements. This means SDs will not only complement other GW observations,
but will be the sole probe of physical processes at certain scales.


title:
Snowmass2021 Cosmic Frontier: Synergies between dark matter searches and
  multiwavelength/multimessenger astrophysics

abstract:
  This whitepaper focuses on the astrophysical systematics which are
encountered in dark matter searches. Oftentimes in indirect and also in direct
dark matter searches, astrophysical systematics are a major limiting factor to
sensitivity to dark matter. Just as there are many forms of dark matter
searches, there are many forms of backgrounds. We attempt to cover the major
systematics arising in dark matter searches using photons -- radio and gamma
rays -- to cosmic rays, neutrinos and gravitational waves. Examples include
astrophysical sources of cosmic messengers and their interactions which can
mimic dark matter signatures. In turn, these depend on commensurate studies in
understanding the cosmic environment -- gas distributions, magnetic field
configurations -- as well as relevant nuclear astrophysics. We also cover the
astrophysics governing celestial bodies and galaxies used to probe dark matter,
from black holes to dwarf galaxies. Finally, we cover astrophysical backgrounds
related to probing the dark matter distribution and kinematics, which impact a
wide range of dark matter studies. In the future, the rise of multi-messenger
astronomy, and novel analysis methods to exploit it for dark matter, will offer
various strategic ways to continue to enhance our understanding of
astrophysical backgrounds to deliver improved sensitivity to dark matter.

categories: hep-ph astro-ph.GA astro-ph.HE astro-ph.IM astro-ph.SR


title:
Fuzzing+Hardware Performance Counters-Based Detection of Algorithm
  Subversion Attacks on Post-Quantum Signature Schemes

abstract:
  NIST is standardizing Post Quantum Cryptography (PQC) algorithms that are
resilient to the computational capability of quantum computers. Past works show
malicious subversion with cryptographic software (algorithm subversion attacks)
that weaken the implementations. We show that PQC digital signature codes can
be subverted in line with previously reported flawed implementations that
generate verifiable, but less-secure signatures, demonstrating the risk of such
attacks. Since, all processors have built-in Hardware Performance Counters
(HPCs), there exists a body of work proposing a low-cost Machine Learning
(ML)-based integrity checking of software using HPC fingerprints. However, such
HPC-based approaches may not detect subversion of PQC codes. A miniscule
percentage of qualitative inputs when applied to the PQC codes improve this
accuracy to 98%. We propose grey-box fuzzing as a pre-processing step to obtain
inputs to aid the HPC-based method.


title: Adaptive Model Predictive Control by Learning Classifiers

abstract:
  Stochastic model predictive control has been a successful and robust control
framework for many robotics tasks where the system dynamics model is slightly
inaccurate or in the presence of environment disturbances. Despite the
successes, it is still unclear how to best adjust control parameters to the
current task in the presence of model parameter uncertainty and heteroscedastic
noise. In this paper, we propose an adaptive MPC variant that automatically
estimates control and model parameters by leveraging ideas from Bayesian
optimisation (BO) and the classical expected improvement acquisition function.
We leverage recent results showing that BO can be reformulated via density
ratio estimation, which can be efficiently approximated by simply learning a
classifier. This is then integrated into a model predictive path integral
control framework yielding robust controllers for a variety of challenging
robotics tasks. We demonstrate the approach on classical control problems under
model uncertainty and robotics manipulation tasks.


title:
Field expansion of holographic image reconstructed from enhanced-NA
  Fresnel hologram

abstract:
  A Fresnel hologram with a high numerical aperture reconstructs a holographic
image at a viewing angle larger than the diffraction angle of a hologram pixel.
The image space is limited by a bandwidth of digital hologram. In this study,
we investigate the property of an image formation on the extended image space
beyond a diffraction zone. A numerical simulation using the phase Fresnel
hologram is carried out to observe an extension of image space and the effect
of it on the change in angular field of view. A uniform image having no
high-order noises can be seen within the primary viewing zone when the viewing
angle is restricted to a diffraction angle. Optical experiments show the
consistent results with the numerical analysis. On the other hand, when the
viewing angle depends on the hologram numerical aperture, the replica noises in
both planes could be in principle removed during the iterative algorithm. We
discuss the development of method for expanding the image space keeping the
viewing angle of a holographic image.


title:
WFI J161953.3+031909: eclipsing ER UMa-type and Z Cam-type star in the
  period gap

abstract:
  WFI J161953.3+031909 was considered to be an eclipsing novalike object in the
period gap. Using the Zwicky Transient Facility (ZTF) public database, I found
that this object is the first eclipsing Z Cam star in the period gap, and is
also most likely an ER UMa star with supercycles of 60-80 d. The longest
outburst (most likely a superoutburst) comprised 35-46% of the supercycle in
the extreme case. If superhumps are confirmed, this becomes the second object
showing both ER UMa and Z Cam states after NY Ser. These objects have
anomalously high mass-transfer rates despite that they are in the period gap. I
refined the orbital period to be 0.099419808(8) d. We can expect to learn from
WFI J161953.3+031909 using eclipses what is actually happening in the ER
UMa-type and Z Cam-type disk. I also provide a revised classification of an
eclipsing IW And star for BMAM-V383 = IPHAS J200822.55+300341.6 by detecting an
IW And-type standstill.


title:
Similarity Equivariant Linear Transformation of Joint Orientation-Scale
  Space Representations

abstract:
  Convolution is conventionally defined as a linear operation on functions of
one or more variables which commutes with shifts. Group convolution generalizes
the concept to linear operations on functions of group elements representing
more general geometric transformations and which commute with those
transformations. Since similarity transformation is the most general geometric
transformation on images that preserves shape, the group convolution that is
equivariant to similarity transformation is the most general shape preserving
linear operator. Because similarity transformations have four free parameters,
group convolutions are defined on four-dimensional, joint orientation-scale
spaces. Although prior work on equivariant linear operators has been limited to
discrete groups, the similarity group is continuous. In this paper, we describe
linear operators on discrete representations that are equivariant to continuous
similarity transformation. This is achieved by using a basis of functions that
is it joint shiftable-twistable-scalable. These pinwheel functions use Fourier
series in the orientation dimension and Laplace transform in the log-scale
dimension to form a basis of spatially localized functions that can be
continuously interpolated in position, orientation and scale. Although this
result is potentially significant with respect to visual computation generally,
we present an initial demonstration of its utility by using it to compute a
shape equivariant distribution of closed contours traced by particles
undergoing Brownian motion in velocity. The contours are constrained by sets of
points and line endings representing well known bistable illusory contour
inducing patterns.


title:
Euclidean Invariant Recognition of 2D Shapes Using Histograms of
  Magnitudes of Local Fourier-Mellin Descriptors

abstract:
  Because the magnitude of inner products with its basis functions are
invariant to rotation and scale change, the Fourier-Mellin transform has long
been used as a component in Euclidean invariant 2D shape recognition systems.
Yet Fourier-Mellin transform magnitudes are only invariant to rotation and
scale changes about a known center point, and full Euclidean invariant shape
recognition is not possible except when this center point can be consistently
and accurately identified. In this paper, we describe a system where a
Fourier-Mellin transform is computed at every point in the image. The spatial
support of the Fourier-Mellin basis functions is made local by multiplying them
with a polynomial envelope. Significantly, the magnitudes of convolutions with
these complex filters at isolated points are not (by themselves) used as
features for Euclidean invariant shape recognition because reliable
discrimination would require filters with spatial support large enough to fully
encompass the shapes. Instead, we rely on the fact that normalized histograms
of magnitudes are fully Euclidean invariant. We demonstrate a system based on
the VLAD machine learning method that performs Euclidean invariant recognition
of 2D shapes and requires an order of magnitude less training data than
comparable methods based on convolutional neural networks.


title:
Ultrafast Inorganic Crystals with Mass Production Capability for Future
  High-Rate Experiments

abstract:
  Future HEP experiments present stringent challenges to inorganic
scintillators in both fast timing response and radiation tolerance. This paper
reports recent progress in developing ultrafast inorganic scintillators with
sub-ns decay time for future precision timing detectors and high-rate
experiments. Performance of fast and ultrafast crystals with mass production
capability are compared to CsI crystals which are used for the Mu2e
calorimeter. Examples are LYSO:Ce, BaF2 and BaF2:Y, which are considered for
Mu2e-II. Crystal radiation hardness against gamma-rays and hadrons is reported.
Current status and development effort for the BaF2:Y crystals are discussed.


title:
Aldous' spectral gap property for normal Cayley graphs on symmetric
  groups

abstract:
  Aldous' spectral gap conjecture states that the second largest eigenvalue of
any connected Cayley graph on the symmetric group Sn with respect to a set of
transpositions is achieved by the standard representation of Sn. This
celebrated conjecture, which was proved in its general form in 2010, has
inspired much interest in searching for other families of Cayley graphs on Sn
with the property that the largest eigenvalue strictly smaller than the degree
is attained by the standard representation of Sn. In this paper, we prove three
results on normal Cayley graphs on Sn possessing this property for sufficiently
large n, one of which can be viewed as a generalization of the "normal" case of
Aldous' spectral gap conjecture.


title: Tunable bulk photovoltaic effect in strained $\gamma$-GeSe

abstract:
  Recently, Lee \textit{et. al.} [Nano Lett. \textbf{21}, 4305 (2021)] newly
synthesized monochalcogenide GeSe in a polar phase, referred to as
$\gamma$-phase. Motivated by this work, we study shift current of $\gamma$-GeSe
and its tunability via an in-plane uniaxial strain. Using first-principles
calculations, we uncover the electronic structure of the strained $\gamma$-GeSe
systems. We then calculate frequency-dependent shift current conductivities at
various strains. The tunability is demonstrated to enhance the shift current up
to $\sim$ 20 $\mu$A/V$^2$. Moreover, the direction of shift current can be
inverted by a light strain. Markedly, an anomalous behavior is found in the
zero-frequency limit, which can be an indicative of band inversion and a
potential topological phase transition driven by the strain. Our results
suggest that shift current can be a tangible prove of bulk electronic states of
$\gamma$-GeSe.


title:
HDPView: Differentially Private Materialized View for Exploring High
  Dimensional Relational Data

abstract:
  How can we explore the unknown properties of high-dimensional sensitive
relational data while preserving privacy? We study how to construct an
explorable privacy-preserving materialized view under differential privacy. No
existing state-of-the-art methods simultaneously satisfy the following
essential properties in data exploration: workload independence, analytical
reliability (i.e., providing error bound for each search query), applicability
to high-dimensional data, and space efficiency. To solve the above issues, we
propose HDPView, which creates a differentially private materialized view by
well-designed recursive bisected partitioning on an original data cube, i.e.,
count tensor. Our method searches for block partitioning to minimize the error
for the counting query, in addition to randomizing the convergence, by choosing
the effective cutting points in a differentially private way, resulting in a
less noisy and compact view. Furthermore, we ensure formal privacy guarantee
and analytical reliability by providing the error bound for arbitrary counting
queries on the materialized views. HDPView has the following desirable
properties: (a) Workload independence, (b) Analytical reliability, (c) Noise
resistance on high-dimensional data, (d) Space efficiency. To demonstrate the
above properties and the suitability for data exploration, we conduct extensive
experiments with eight types of range counting queries on eight real datasets.
HDPView outperforms the state-of-the-art methods in these evaluations.


title:
Robust 2-D DOA Estimation in a Polarization Sensitive Single User
  Environment

abstract:
  Apart from the conventional parameters (such as signal-to-noise ratio, array
geometry and size, sample size), several other factors (e.g. alignment of the
antenna elements, polarization parameters) influence the performance of
direction of arrival (DOA) estimating algorithms. When all the antenna elements
are identically aligned, the polarization parameters do not affect the steering
vectors, which is the underlying assumption of all the conventional DOA
algorithms. Unfortunately, in this case, for a given set of DOA angles there
exists a range of polarization parameters which could result in a very low
signal-to-noise ratio (SNR) across all the antenna elements in the array. To
avoid this type of catastrophic event, different antenna element needs to be
aligned differently. However, this fact will make almost all commonly used DOA
estimation algorithms non-operable, since the steering vectors are contaminated
by the polarization parameters. To the best of our knowledge, no work in the
literature addresses this issue even for a single user environment. In this
paper, that line of inquiry is pursued. We consider a circular array with the
minimum number of antenna elements and propose an antenna alignment scheme to
ensure that at any given point no more than one element will suffer from
significantly low SNR due to the contribution of polarization. A low complexity
algorithm that estimates the DOA angles in a closed-form manner is developed.
We treat MUSIC as the baseline algorithm and demonstrate how it can reliably
operate in all possible DOA and polarization environments. Finally, a thorough
performance and complexity analysis are illustrated for the above two
algorithms.


title:
Can pre-trained Transformers be used in detecting complex sensitive
  sentences? -- A Monsanto case study

abstract:
  Each and every organisation releases information in a variety of forms
ranging from annual reports to legal proceedings. Such documents may contain
sensitive information and releasing them openly may lead to the leakage of
confidential information. Detection of sentences that contain sensitive
information in documents can help organisations prevent the leakage of valuable
confidential information. This is especially challenging when such sentences
contain a substantial amount of information or are paraphrased versions of
known sensitive content. Current approaches to sensitive information detection
in such complex settings are based on keyword-based approaches or standard
machine learning models. In this paper, we wish to explore whether pre-trained
transformer models are well suited to detect complex sensitive information.
Pre-trained transformers are typically trained on an enormous amount of text
and therefore readily learn grammar, structure and other linguistic features,
making them particularly attractive for this task. Through our experiments on
the Monsanto trial data set, we observe that the fine-tuned Bidirectional
Encoder Representations from Transformers (BERT) transformer model performs
better than traditional models. We experimented with four different categories
of documents in the Monsanto dataset and observed that BERT achieves better F2
scores by 24.13\% to 65.79\% for GHOST, 30.14\% to 54.88\% for TOXIC, 39.22\%
for CHEMI, 53.57\% for REGUL compared to existing sensitive information
detection models.


title: Dichotomy and measures on limit sets of Anosov groups

abstract:
  Let $G$ be a connected semisimple real algebraic group. For any Zariski dense
Anosov subgroup $\Gamma <G$, we show that a $\Gamma$-conformal measure is
supported on the limit set of $\Gamma$ if and only if its "dimension" is
$\Gamma$-critical. This implies the uniqueness of a $\Gamma$-conformal measure
for each critical dimension. We deduce this from a higher rank analogue of the
Hopf-Tsuji-Sullivan dichotomy for the maximal diagonal action. Other
applications include an analogue of the Ahlfors measure conjecture for Anosov
subgroups.


title: Snowmass2021: Opportunities from Cross-survey Analyses of Static Probes

abstract:
  Cosmological data in the next decade will be characterized by high-precision,
multi-wavelength measurements of thousands of square degrees of the same
patches of sky. By performing multi-survey analyses that harness the correlated
nature of these datasets, we will gain access to new science, and increase the
precision and robustness of science being pursued by each individual survey.
However, effective application of such analyses requires a qualitatively new
level of investment in cross-survey infrastructure, including simulations,
associated modeling, coordination of data sharing, and survey strategy. The
scientific gains from this new level of investment are multiplicative, as the
benefits can be reaped by even present-day instruments, and can be applied to
new instruments as they come online.


title:
Realization of a photonic topological insulator in Kagome crystals at
  terahertz wavelengths

abstract:
  Topological systems are inherently robust to disorder and continuous
perturbations, resulting in dissipation-free edge transport of electrons in
quantum solids, or reflectionless guiding of photons and phonons in classical
wave systems characterized by topological invariants. Despite considerable
efforts, direct experimental demonstration of theoretically predicted robust,
lossless energy transport in topological insulators operating at terahertz
frequencies is needed further investigations to shed affirmative light on the
unique properties enabled by topological protection. Here, we introduce Kagome
lattice that exhibits a new class of symmetry-protected topological phases with
very low Berry curvature but nontrivial bulk polarization, and fabricate an
optical topological insulator that provide the valley hall effect. Theoretical
analysis show that four type edge states can be obtained. Measurements of
THz-TDs with high time-resolution demonstrate that terahertz wave propagating
along the straight topological edge and Z-shape edge with sharp turns have
almost same high transmission in 0.440 THz to 0.457 THz domain range. Those
results quantitatively illustrate the suppression of backscattering due to the
non-trivial topology of the structure. The THz-TDs measurement yields amplitude
and phase information, showing significant advantage compared to general
broadband infrared, single wavelength continuous-wave THz measurements and
visible spectroscopy. It allows further exploration of the effective refractive
index, group velocity and dispersion relations of edge states. Our work offers
possibilities for advanced control of the propagation and manipulation of THz
waves, and facilitates the applications including sixth-generation (6G)
wireless communication, terahertz integrated circuits, and interconnects for
intrachip and interchip communication.


title: Exclusive $D_s^{\ast}$ weak decays and the experiment potential

abstract:
  The decay width of the $D_s^{\ast}$ meson is dominated by the electromagnetic
mode, and it is thus the longest-lived charged vector meson. In light of this
point, we perform the first QCD LCSRs calculation of $D_s^{\ast}\to \phi$
helicity form factors and discuss the experiment potential of discovering
exclusive $D_s^{\ast}$ weak decays. The main result is the partial decay
widths, which read as $\Gamma_{D_s^\ast \to l \nu} = 2.44 \times 10^{-12} \,
{\rm GeV}$, $\Gamma_{D_s^\ast \to \phi l \nu} = (1.37^{+0.29}_{-0.17}) \times
10^{-13} \, {\rm GeV}$, $\Gamma_{D_s^\ast \to \phi \pi} = (0.39 \pm 0.03)
\times 10^{-13} \, {\rm GeV}$ and $\Gamma_{D_s^\ast \to \phi \rho} =
(1.41^{+0.54}_{-0.32}) \times 10^{-13} {\rm GeV}$. We show that these channels
are promising in the near future, serving as the first experimental observation
of weak decays of a vector meson, and would open up a new playground for
precision test of the standard model.


title: The Role of Local Steps in Local SGD

abstract:
  We consider the distributed stochastic optimization problem where $n$ agents
want to minimize a global function given by the sum of agents' local functions,
and focus on the heterogeneous setting when agents' local functions are defined
over non-i.i.d. data sets. We study the Local SGD method, where agents perform
a number of local stochastic gradient steps and occasionally communicate with a
central node to improve their local optimization tasks. We analyze the effect
of local steps on the convergence rate and the communication complexity of
Local SGD. In particular, instead of assuming a fixed number of local steps
across all communication rounds, we allow the number of local steps during the
$i$-th communication round, $H_i$, to be different and arbitrary numbers. Our
main contribution is to characterize the convergence rate of Local SGD as a
function of $\{H_i\}_{i=1}^R$ under various settings of strongly convex,
convex, and nonconvex local functions, where $R$ is the total number of
communication rounds. Based on this characterization, we provide sufficient
conditions on the sequence $\{H_i\}_{i=1}^R$ such that Local SGD can achieve
linear speed-up with respect to the number of workers. Furthermore, we propose
a new communication strategy with increasing local steps superior to existing
communication strategies for strongly convex local functions. On the other
hand, for convex and nonconvex local functions, we argue that fixed local steps
are the best communication strategy for Local SGD and recover state-of-the-art
convergence rate results. Finally, we justify our theoretical results through
extensive numerical experiments.


title: Future prospects for parton showers

abstract:
  In this brief Snowmass White Paper for the Theory Frontier, we argue that
there have been important recent developments in the algorithms used to
generate a simulated parton shower and that further progress can be achieved in
the coming decade. A much more detailed exposition can be found in a
corresponding White Paper of the Energy Frontier.


title: Strategies for conformal REBCO windings

abstract:
  A high-field winding can be fabricated from a cable of non-insulated REBCO
tapes, stacked face-face without twisting. If the cable is oriented within each
turn of a winding so that the tape face is closely parallel to the magnetic
field at its location, the supercurrent capacity of that cable is enhanced ~3x
greater than in a transverse or twisting orientation. This concept for a
conformal winding was presented in a previous paper pertinent to the body
winding of a high-field dipole. Strategies are presented and simulated for how
the same orientation can be sustained in the flared ends of a dipole.


title:
MetaBalance: Improving Multi-Task Recommendations via Adapting Gradient
  Magnitudes of Auxiliary Tasks

abstract:
  In many personalized recommendation scenarios, the generalization ability of
a target task can be improved via learning with additional auxiliary tasks
alongside this target task on a multi-task network. However, this method often
suffers from a serious optimization imbalance problem. On the one hand, one or
more auxiliary tasks might have a larger influence than the target task and
even dominate the network weights, resulting in worse recommendation accuracy
for the target task. On the other hand, the influence of one or more auxiliary
tasks might be too weak to assist the target task. More challenging is that
this imbalance dynamically changes throughout the training process and varies
across the parts of the same network. We propose a new method: MetaBalance to
balance auxiliary losses via directly manipulating their gradients w.r.t the
shared parameters in the multi-task network. Specifically, in each training
iteration and adaptively for each part of the network, the gradient of an
auxiliary loss is carefully reduced or enlarged to have a closer magnitude to
the gradient of the target loss, preventing auxiliary tasks from being so
strong that dominate the target task or too weak to help the target task.
Moreover, the proximity between the gradient magnitudes can be flexibly
adjusted to adapt MetaBalance to different scenarios. The experiments show that
our proposed method achieves a significant improvement of 8.34% in terms of
NDCG@10 upon the strongest baseline on two real-world datasets. The code of our
approach can be found at here: https://github.com/facebookresearch/MetaBalance


title:
In-depth characterization and analysis of simple shear flows over
  regularly arranged micro pillars, II. Effect of pillar arrangement

abstract:
  Through high-fidelity numerical simulation, the effect of the arrangement of
micropillars on the flow characteristics and momentum transport has been
extensively investigated. The surface friction due to the complex flow
characteristics and momentum transport mechanism has also been studied in
depth. The micropillars are arranged in a quadrilateral, and different
arrangements are acquired by changing the streamwise and spanwise distances
between pillar rows. The results show that the streamwise and spanwise pillar
distances have their own different influences. When the streamwise pillar
distance is small, the micro eddies in the gaps between the streamwise
neighboring pillars are significantly suppressed. The increase in the spanwise
pillar distance enhances the momentum transport from the flow above pillar
array to the flow in the spaces among micro pillars. When the spanwise pillar
distance is small, the micro eddies in the gaps between the streamwise
neighboring pillars connect with each other and form a tubular eddy between
each pair of spanwise pillar rows. The tubular eddies significantly reduce the
momentum transport from the upper flow to the lower flow. The increase in the
streamwise pillar distance increase the momentum flux slightly. The surface
friction can be decomposed into three components which are associated with two
factors, the dilution effect of the number density of micro pillars and the
multi-faceted effects of micro eddies. These two factors are determined by the
streamwise and spanwise pillar distances. The dependence of the total friction
and its components on the pillar distances has been thoroughly examined.


title:
Learning Markov Games with Adversarial Opponents: Efficient Algorithms
  and Fundamental Limits

abstract:
  An ideal strategy in zero-sum games should not only grant the player an
average reward no less than the value of Nash equilibrium, but also exploit the
(adaptive) opponents when they are suboptimal. While most existing works in
Markov games focus exclusively on the former objective, it remains open whether
we can achieve both objectives simultaneously. To address this problem, this
work studies no-regret learning in Markov games with adversarial opponents when
competing against the best fixed policy in hindsight. Along this direction, we
present a new complete set of positive and negative results:
  When the policies of the opponents are revealed at the end of each episode,
we propose new efficient algorithms achieving $\sqrt{K}$-regret bounds when
either (1) the baseline policy class is small or (2) the opponent's policy
class is small. This is complemented with an exponential lower bound when
neither conditions are true. When the policies of the opponents are not
revealed, we prove a statistical hardness result even in the most favorable
scenario when both above conditions are true. Our hardness result is much
stronger than the existing hardness results which either only involve
computational hardness, or require further restrictions on the algorithms.


title: Infinite Wordle and the Mastermind numbers

abstract:
  I consider the natural infinitary variations of the games Wordle and
Mastermind, as well as their game-theoretic variations Absurdle and
Madstermind, considering these games with infinitely long words and infinite
color sequences and allowing transfinite game play. For each game, a secret
codeword is hidden, which the codebreaker attempts to discover by making a
series of guesses and receiving feedback as to their accuracy. In Wordle with
words of any size from a finite alphabet of $n$ letters, including infinite
words or even uncountable words, the codebreaker can nevertheless always win in
$n$ steps. Meanwhile, the mastermind number, defined as the smallest winning
set of guesses in infinite Mastermind for sequences of length $\omega$ over a
countable set of colors without duplication, is uncountable, but the exact
value turns out to be independent of ZFC, for it is provably equal to the
eventually different number $\frak{d}({\neq^*})$, which is the same as the
covering number of the meager ideal $\text{cov}(\mathcal{M})$. I thus place all
the various mastermind numbers, defined for the natural variations of the game,
into the hierarchy of cardinal characteristics of the continuum.


title: Snowmass White Paper: UV Constraints on IR Physics

abstract:
  Fundamental principles of local quantum field theory or of quantum gravity
can enforce consistency requirements on the space of consistent low-energy
effective field theories. We survey the various techniques that have been used
to put UV constraints on IR physics, including those from causality
considerations in the form of S-matrix positivity and bootstrap bounds,
scattering time delays, conformal field theory and holographic methods,
together with those that arise from landscape/swampland criteria such as the
weak gravity conjecture. We review recent applications of these constraints to
corrections to Standard Model physics, corrections to Einstein gravity, and
cosmological theories and highlight promising future directions.


title:
Anisotropic Electrene T'-Ca2P with Electron Gas Magnetic Coupling as
  Anode Material for Na/K Ion Batteries

abstract:
  There is an urgently need for the high-performance rechargeable electrical
storage devices as supplement or substitutions of lithium ion batteries due to
the shortage of lithium in nature. Herein we propose a stable 2D electrene
T'-Ca2P as anode material for Na/K ion batteries by first-principle
calculations. Our calculated results show that T'-Ca2P monolayer is an
antiferromagnetic semiconducting electrene with spin-polarized electron gas. It
exhibits suitable adsorption for both Na and K atoms, and its anisotropic
migration energy barriers are 0.050/0.101 eV and 0.037/0.091 eV in b/a
direction, respectively. The theoretical capacities for Na and K are both 482
mAh/g, while the average working voltage platforms are 0.171-0.226 V and
0.013-0.267 V, respectively. All the results reveal that the T'-Ca2P monolayer
has promised application prospects as anode materials for Na/K ion batteries.


title:
Towards Semantic Search for Community Question Answering for Mortgage
  Officers

abstract:
  Community Question Answering (CQA) has gained increasing popularity in many
domains. Mortgage is a complex and dynamic industry, and a flexible and
efficient CQA platform can potentially enhance the quality of service for
mortgage officers significantly. We have built a dynamic CQA platform with a
state of the art semantic search engine based on recent Natural Language
Processing (NLP) techniques to dynamically and collectively capture and
transfer the maturity and tribal knowledge of the more experienced workforce to
less experienced ones. The search engine allows for both keyword and natural
language queries and is based on a fine-tuned domain-adapted Sentence-BERT
encoder linearly composed with a TF-IDF vectorizer, and reciprocal-rank fused
with a BM25 vectorizer. Domain adaptation and fine-tuning is based on publicly
available mortgage corpora. Evaluation is performed on an internally annotated
dataset using standard information retrieval metrics such as normalized
discounted cumulative gain (nDCG), precision/recall at n, mean reciprocal rank,
and mean average precision (MAP). The results indicate that our hybrid,
fine-tuned, domain-adapted search engine is a more effective approach in
responding to the information needs of our mortgage officers compared to
traditional search techniques. We aim to publish the internally-annotated
evaluation and training datasets in the near future.


title:
Ultra-High Lithium Storage Capacity of Al2C Monolayer under Restricted
  Multilayered Growth Mechanism

abstract:
  Designing anode materials with high lithium specific capacity is crucial to
the development of high energy-density lithium ion batteries. Herein, a
distinctive lithium growth mechanism, namely, the restricted multilayered
growth for lithium, and a strategy for lithium storage are proposed to achieve
the balance between the ultra-high specific capacity and the need to avert
uncontrolled dendritic growth of lithium. In particular, based on
first-principles computation, we show that the Al2C monolayer with planar
tetracoordinate carbon structure can be an ideal platform for realizing the
restricted multilayered growth mechanism as a 2D anode material. Furthermore,
the Al2C monolayer exhibits ultra-high specific capacity of lithium of 4059
mAh/g, yet with a low dif-fusion barrier of 0.039-0.17 eV as well as low open
circuit voltage in the range of 0.002-0.34 V. These novel properties endow the
Al2C monolayer a promising anode material for future lithium ion batteries. Our
study offers a new way to design promising 2D anode materials with high
specific capacity, fast lithium-ion diffusion, and safe lithium storage
mechanism.


title: Ion Coulomb Crystals in Storage Rings for Quantum Information Science

abstract:
  Quantum information science is a growing field that promises to take
computing into a new age of higher performance and larger scale computing as
well as being capable of solving problems classical computers are incapable of
solving. The outstanding issue in practical quantum computing today is scaling
up the system while maintaining interconnectivity of the qubits and low error
rates in qubit operations to be able to implement error correction and
fault-tolerant operations. Trapped ion qubits offer long coherence times that
allow error correction. However, error correction algorithms require large
numbers of qubits to work properly. We can potentially create many thousands
(or more) of qubits with long coherence states in a storage ring. For example,
a circular radio-frequency quadrupole, which acts as a large circular ion trap
and could enable larger scale quantum computing. Such a Storage Ring Quantum
Computer (SRQC) would be a scalable and fault tolerant quantum information
system, composed of qubits with very long coherence lifetimes. With computing
demands potentially outpacing the supply of high-performance systems, quantum
computing could bring innovation and scientific advances to particle physics
and other DOE supported programs. Increased support of R$\&$D in large scale
ion trap quantum computers would allow the timely exploration of this exciting
new scalable quantum computer. The R$\&$D program could start immediately at
existing facilities and would include the design and construction of a
prototype SRQC. We invite feedback from and collaboration with the particle
physics and quantum information science communities.