title: Click-Through Rate Prediction in Online Advertising: A Literature Review

abstract:
  Predicting the probability that a user will click on a specific advertisement
has been a prevalent issue in online advertising, attracting much research
attention in the past decades. As a hot research frontier driven by industrial
needs, recent years have witnessed more and more novel learning models employed
to improve advertising CTR prediction. Although extant research provides
necessary details on algorithmic design for addressing a variety of specific
problems in advertising CTR prediction, the methodological evolution and
connections between modeling frameworks are precluded. However, to the best of
our knowledge, there are few comprehensive surveys on this topic. We make a
systematic literature review on state-of-the-art and latest CTR prediction
research, with a special focus on modeling frameworks. Specifically, we give a
classification of state-of-the-art CTR prediction models in the extant
literature, within which basic modeling frameworks and their extensions,
advantages and disadvantages, and performance assessment for CTR prediction are
presented. Moreover, we summarize CTR prediction models with respect to the
complexity and the order of feature interactions, and performance comparisons
on various datasets. Furthermore, we identify current research trends, main
challenges and potential future directions worthy of further explorations. This
review is expected to provide fundamental knowledge and efficient entry points
for IS and marketing scholars who want to engage in this area.


title: Hypergraph LSS-ideals and coordinate sections of symmetric tensors

abstract:
  Let K be a field, [n]= {1,...,n} and H=([n],E) be a hypergraph. For an
integer d >= 1 the Lovasz-Saks-Schrijver ideal (LSS-ideal) L_H^K (d) in
K[y_{ij}~:~(i,j) \in [n] x [d]] is the ideal generated by the polynomials
$f^{(d)}_{e}= \sum\limits_{j=1}^{d} \prod\limits_{i \in e} y_{ij}$ for edges e
of H. In this paper for an algebraically closed field K and a k-uniform
hypergraph H=([n],E) we employ a connection between LSS-ideals and coordinate
sections of the closure of the set S_{n,k}^d of homogeneous degree k symmetric
tensors in n variables of rank <= d to derive results on the irreducibility of
its coordinate sections. To this end we provide results on primality and the
complete intersection property of L_H^K (d). We then use the combinatorial
concept of positive matching decomposition of a hypergraph H to provide bounds
on when L_H^K(d) turns prime to provide results on the irreducibility of
coordinate sections of S_{n, k}^d.


title:
A Globally Convergent Evolutionary Strategy for Stochastic Constrained
  Optimization with Applications to Reinforcement Learning

abstract:
  Evolutionary strategies have recently been shown to achieve competing levels
of performance for complex optimization problems in reinforcement learning. In
such problems, one often needs to optimize an objective function subject to a
set of constraints, including for instance constraints on the entropy of a
policy or to restrict the possible set of actions or states accessible to an
agent. Convergence guarantees for evolutionary strategies to optimize
stochastic constrained problems are however lacking in the literature. In this
work, we address this problem by designing a novel optimization algorithm with
a sufficient decrease mechanism that ensures convergence and that is based only
on estimates of the functions. We demonstrate the applicability of this
algorithm on two types of experiments: i) a control task for maximizing rewards
and ii) maximizing rewards subject to a non-relaxable set of constraints.


title:
Implementation of the rROF denoising method in the cWB pipeline for
  gravitational-wave data analysis

abstract:
  The data collected by the current network of gravitational-wave detectors are
largely dominated by instrumental noise. Total variation methods based on
L1-norm minimization have recently been proposed as a powerful technique for
noise removal in gravitational-wave data. In particular, the regularized
Rudin-Osher-Fatemi (rROF) model has proven effective to denoise signals
embedded in either simulated Gaussian noise or actual detector noise. Importing
the rROF model to existing search pipelines seems therefore worth considering.
In this paper, we discuss the implementation of two variants of the rROF
algorithm as two separate plug-ins of the coherent Wave Burst (cWB) pipeline
designed to conduct searches of unmodelled gravitational-wave burst sources.
The first approach is based on a single-step rROF method and the second one
employs an iterative rROF procedure. Both approaches are calibrated using
actual gravitational-wave events from the first three observing runs of the
LIGO-Virgo-KAGRA collaboration, namely GW1501914, GW151226, GW170817, and
GW190521, encompassing different types of compact binary coalescences. Our
analysis shows that the iterative version of the rROF denoising algorithm
implemented in the cWB pipeline effectively eliminates noise while preserving
the waveform signals intact. Therefore, the combined approach yields higher
signal-to-noise values than those computed by the cWB pipeline without the rROF
denoising step. The incorporation of the iterative rROF algorithm in the cWB
pipeline might hence impact the detectability capabilities of the pipeline
along with the inference of source properties.


title: 4d strings at strong coupling

abstract:
  Weakly coupled regions of 4d EFTs coupled to gravity are particularly
suitable to describe the backreaction of BPS fundamental axionic strings,
dubbed EFT strings, in a local patch of spacetime around their core. We study
the extension of these local solutions to global ones, which implies probing
regions of strong coupling and provides an estimate of the EFT string tension
therein. We conjecture that for the EFT string charge generators such a global
extension is always possible and yields a sub-Planckian tension. We
substantiate this claim by analysing global solutions of 4d strings made up
from NS5-branes wrapping Calabi-Yau threefold divisors in either type IIA or
heterotic string theory. We argue that in this case the global,
non-perturbative data of the backreaction can be simply encoded in terms of a
GLSM describing the compactification, as we demonstrate in explicit examples.


title: Quantum Metric Induced Phases in Moir\'e Materials

abstract:
  We show that, quite generally, quantum geometry plays a major role in
determining the low-energy physics in strongly correlated lattice models at
fractional band fillings. We identify limits in which the Fubini Study metric
dictates the ground states and show that this is highly relevant for Moir\'e
materials leading to symmetry breaking and interaction driven Fermi liquids.
This phenomenology stems from a novel interplay between the quantum geometry
and interactions which is absent in continuum Landau levels but generically
present in lattice models where these terms tend to destabilize e.g. fractional
Chern insulators. We explain this as a consequence of the fundamental asymmetry
between electrons and holes for band projected normal ordered interactions, as
well as from the perspective of a self-consistent Hartree-Fock calculation.
These basic insights about the role of the quantum metric turn, when dominant,
an extremely strongly coupled problem into an effectively weakly coupled one,
and may also serve as a guiding principle for designing material setups.

categories: cond-mat.str-el cond-mat.mes-hall cond-mat.mtrl-sci quant-ph


title:
Towards ruling out the charged Higgs interpretation of the $R_{D^{(*)}}$
  anomaly

abstract:
  Motivated by the notorious anomaly in the lepton flavor universality ratios
$R_{D^{(*)}}$, we study the sensitivity of the Large Hadron Collider (LHC) to a
low-mass charged Higgs boson $H^-$ lighter than $400\,$GeV in a generic two
Higgs doublet model. A combination of current constraints from the $B_c\to\tau
\nu$ decay, $B_{s}$ meson mixing data, tau sleptons and di-jet searches at the
LHC allows to explain the $R_{D^{(*)}}$ anomaly at the $1\,\sigma$ level by a
low-mass charged Higgs. In this context, we estimate the reach of an LHC search
for resonant $H^-$ production, where the final state contains an energetic
$\tau$ lepton decaying hadronically, a neutrino with large transverse momentum,
and an additional $b$-jet ($pp \to b+\tau_h + \nu$). Requiring the additional
$b$-tagged jet in the $\tau\nu$ resonance search profits from the suppression
of the Standard Model background, and therefore it allows us to judge the
low-mass $H^-$ interpretation of the $R_{D^{(*)}}$ anomaly. To demonstrate
this, we perform a fast collider simulation for the $\tau \nu$ resonance search
with an additional $b$-tagged jet, and find that most of the interesting
parameter region of the whole mass range can already be probed with the current
integrated luminosity of $139\,$fb$^{-1}$.


title:
The SAMI Galaxy Survey: the difference between ionised gas and stellar
  velocity dispersions

abstract:
  We investigate the mean locally-measured velocity dispersions of ionised gas
($\sigma_{\rm gas}$) and stars ($\sigma_*$) for 1090 galaxies with stellar
masses $\log\,(M_*/M_{\odot}) \geq 9.5$ from the SAMI Galaxy Survey. For
star-forming galaxies, $\sigma_*$ tends to be larger than $\sigma_{\rm gas}$,
suggesting that stars are in general dynamically hotter than the ionised gas
(asymmetric drift). The difference between $\sigma_{\rm gas}$ and $\sigma_*$
($\Delta\sigma$) correlates with various galaxy properties. We establish that
the strongest correlation of $\Delta\sigma$ is with beam smearing, which
inflates $\sigma_{\rm gas}$ more than $\sigma_*$, introducing a dependence of
$\Delta\sigma$ on both the effective radius relative to the point spread
function and velocity gradients. The second-strongest correlation is with the
contribution of active galactic nuclei (AGN) (or evolved stars) to the ionised
gas emission, implying the gas velocity dispersion is strongly affected by the
power source. In contrast, using the velocity dispersion measured from
integrated spectra ($\sigma_{\rm aper}$) results in less correlation between
the aperture-based $\Delta\sigma$ ($\Delta\sigma_{\rm aper}$) and the power
source. This suggests that the AGN (or old stars) dynamically heat the gas
without causing significant deviations from dynamical equilibrium. Although the
variation of $\Delta\sigma_{\rm aper}$ is much smaller than that of
$\Delta\sigma$, a correlation between $\Delta\sigma_{\rm aper}$ and gas
velocity gradient is still detected, implying there is a small bias in
dynamical masses derived from stellar and ionised gas velocity dispersions.


title:
Calibration of quasi-static aberrations in exoplanet direct-imaging
  instruments with a Zernike phase-mask sensor. IV. Temporal stability of
  non-common path aberrations in VLT/SPHERE

abstract:
  Coronagraphic imaging of exoplanets using ground-based instruments on large
telescopes is intrinsically limited by speckles induced by uncorrected
aberrations. These aberrations originate from the imperfect correction of the
atmosphere by an extreme adaptive optics system; from static optical defects;
or from small opto-mechanical variations due to changes in temperature,
pressure, or gravity vector. More than the speckles themselves, the performance
of high-contrast imagers is ultimately limited by their temporal stability,
since most post-processing techniques rely on difference of images acquired at
different points in time. Identifying the origin of the aberrations and the
timescales involved is therefore crucial to understanding the fundamental
limits of dedicated high-contrast instruments. We previously demonstrated the
use of a Zernike wavefront sensor called ZELDA for sensing non-common path
aberrations (NCPA) in VLT/SPHERE. We now use ZELDA to investigate the stability
of the instrumental aberrations using 5 long sequences of measurements obtained
at high cadence on the internal source. Our study reveals two regimes of
decorrelation of the NCPA. The first, with a characteristic timescale of a few
seconds and an amplitude of a few nanometers, is induced by a fast internal
turbulence within the enclosure. The second is a slow quasi-linear
decorrelation on the order of a few $10^{-3}$ nm rms/s that acts on timescales
from minutes to hours. We use coronagraphic image reconstruction to demonstrate
that these two NCPA contributions have a measurable impact on differences of
images, and that the fast internal turbulence is a dominating term over to the
slow linear decorrelation. We also use dedicated sequences where the derotator
and atmospheric dispersion compensators emulate a real observation to
demonstrate the importance of performing observations symmetric around the
meridian.


title:
Classical versus Quantum: comparing Tensor Network-based Quantum
  Circuits on LHC data

abstract:
  Tensor Networks (TN) are approximations of high-dimensional tensors designed
to represent locally entangled quantum many-body systems efficiently. This
study provides a comprehensive comparison between classical TNs and TN-inspired
quantum circuits in the context of Machine Learning on highly complex,
simulated LHC data. We show that classical TNs require exponentially large bond
dimensions and higher Hilbert-space mapping to perform comparably to their
quantum counterparts. While such an expansion in the dimensionality allows
better performance, we observe that, with increased dimensionality, classical
TNs lead to a highly flat loss landscape, rendering the usage of gradient-based
optimization methods highly challenging. Furthermore, by employing quantitative
metrics, such as the Fisher information and effective dimensions, we show that
classical TNs require a more extensive training sample to represent the data as
efficiently as TN-inspired quantum circuits. We also engage with the idea of
hybrid classical-quantum TNs and show possible architectures to employ a larger
phase-space from the data. We offer our results using three main TN ansatz:
Tree Tensor Networks, Matrix Product States, and Multi-scale Entanglement
Renormalisation Ansatz.


title: Hydrodynamic electron transport in graphene Hall-bar devices

abstract:
  We consider hydrodynamic electron transport in the Hall-bar geometry. The
theory is developed for systems with non-Galilean-invariant electron liquids.
We show that inhomogeneity of the electron density induced by long-range
disorder and gating leads to mixing between the hydrodynamic transport mode and
transport relative to the electron liquid. For graphene systems near charge
neutrality, these effects lead to strong coupling of the hydrodynamic flow to
charge transport. As a result, the effective electrical conductivity of the
system may significantly exceed the intrinsic conductivity of the electron
liquid. We obtain analytic expressions for the thermoelectric transport
coefficients of the system as a function of density in the full crossover
region between clean and disorder-dominated regimes.


title: Higher-derivative holography with a chemical potential

abstract:
  We carry out an extensive study of the holographic aspects of any-dimensional
higher-derivative Einstein-Maxwell theories in a fully analytic and
non-perturbative fashion. We achieve this by introducing the $d$-dimensional
version of Electromagnetic Quasitopological gravities: higher-derivative
theories of gravity and electromagnetism that propagate no additional degrees
of freedom and that allow one to study charged black hole solutions
analytically. These theories contain non-minimal couplings, that in the
holographic context give rise to a modified $\langle JJ\rangle$ correlator as
well as to a general $\langle TJJ \rangle$ structure whose coefficients we
compute. We constrain the couplings of the theory by imposing CFT unitarity and
positivity of energy (which we show to be equivalent to causality in the bulk)
as well as positive-entropy bounds from the weak gravity conjecture. The
thermodynamic properties of the dual plasma at finite chemical potential are
studied in detail, and we find that exotic zeroth-order phase transitions may
appear, but that many of them are ruled out by the physical constraints. We
further compute the shear viscosity to entropy density ratio, and we show that
it can be taken to zero while respecting all the constraints, providing that
the chemical potential is large enough. We also obtain the charged R\'enyi
entropies and we observe that the chemical potential always increases the
amount of entanglement and that the usual properties of R\'enyi entropies are
preserved if the physical constraints are met. Finally, we compute the scaling
dimension and magnetic response of twist operators and we provide a holographic
derivation of the universal relations between the expansion of these quantities
and the coefficients of $\langle JJ\rangle$ and $\langle TJJ \rangle$.


title:
Probing Miracle-less WIMP Dark Matter via Gravitational Waves Spectral
  Shapes

abstract:
  We propose a novel probe of weakly interacting massive particle (WIMP) dark
matter candidates of a wide mass range which fall short of the required
annihilation rates to satisfy correct thermal relic abundance, dubbed as
\textit{Miracle-less WIMP}. If the dark matter (DM) interactions are mediated
by an Abelian gauge boson like B-L, its annihilation rates typically remain
smaller than the WIMP ballpark for very high scale B-L symmetry breaking. The
thermally overproduced WIMP DM is brought within correct relic limits via late
entropy dilution from one of the three right handed neutrinos (RHN) present for
keeping the model anomaly free and generate light neutrino masses. Such late
entropy injection leads to peculiar spectral shapes of gravitational waves (GW)
generated by cosmic strings, formed as a result of B-L symmetry breaking. We
find interesting correlation between DM mass and turning frequency of the GW
spectrum with the latter being within reach of future experiments. The two
other RHNs play major role in generating light neutrino masses and baryon
asymmetry of the universe via leptogenesis. Successful leptogenesis with
Miracle-less WIMP together restrict the turning frequencies to lie only within
the sensitivity limits of future GW experiments like Cosmic Explorer and
Einstein Telescope.


title: Interplay of superconductivity and dissipation in quantum Hall edges

abstract:
  Systems harboring parafermion zero-modes hold promise as platforms for
topological quantum computation. Recent experimental work (G\"{u}l et al.,
arXiv:2009.07836) provided evidence for proximity-induced superconductivity in
fractional quantum Hall edges, a prerequisite in proposed realizations of
parafermion zero-modes. The main evidence was the observation of a crossed
Andreev reflection signal, in which electrons enter the superconductor from one
chiral mode and are reflected as holes to another, counter-propagating chiral
mode. Remarkably, while the probability for cross Andreev reflection was much
smaller than one, it was stronger for $\nu=1/3$ fractional quantum Hall edges
than for integer ones. We theoretically explain these findings, including the
relative strengths of the signals in the two cases and their qualitatively
different temperature dependencies. Beyond the coupling of the two
counter-propagating modes through Andreev reflection and back-scattering, an
essential part of our model is the coupling of the edge modes to normal states
in the cores of Abrikosov vortices located close to the edges. These vortices
are made dense by the magnetic field needed to form the quantum Hall states,
and provide a metallic bath to which the edges are tunnel-coupled. The stronger
crossed Andreev reflection in the fractional case originates from the
suppression of electronic tunneling between the bath and the fractional quantum
Hall edges. Our theory shows that the mere observation of crossed Andreev
reflection signal does not necessarily imply the presence of localized
parafermion zero-modes, and suggests ways to identify their presence from the
behavior of this signal in the low temperature limit.


title: Cotton Double Copy for Gravitational Waves

abstract:
  We construct a double copy relation between the Cotton spinor and the dual
field strength spinor of topologically massive theories, as the
three-dimensional analogue of the Weyl double copy. The relationship holds in
curved backgrounds for wave solutions. We give an explicit proof for Type N
spacetimes and show examples satisfying the Cotton double copy.


title:
Exploring metallicity-dependent rates of Type Ia supernovae and their
  impact on galaxy formation

abstract:
  Type Ia supernovae play a critical role in stellar feedback and elemental
enrichment in galaxies. Recent transient surveys like the All-Sky Automated
Survey for Supernova (ASAS-SN) and the Dark Energy Survey (DES) find that the
specific Ia rate at z ~ 0 may be ~ 15-50 times higher in lower-mass galaxies
than at Milky Way-mass. Independently, Milky Way observations show that the
close-binary fraction of solar-type stars is higher at lower metallicity.
Motivated by these observations, we use the FIRE-2 cosmological zoom-in
simulations to explore the impact of varying Ia rate models, including
metallicity dependence, on galaxies across a range of stellar masses: 10^7 Msun
- 10^{11} Msun. First, we benchmark our simulated star-formation histories
(SFHs) against observations. We show that assumed SFHs and stellar mass
functions play a major role in determining the degree of tension between
observations and metallicity-independent Ia rate models, and potentially cause
ASAS-SN and DES observations to be much more consistent with each other than
might naively appear. Models in which the Ia rate increases with decreasing
metallicity (as ~ Z^{-0.5} to Z^{-1}) provide significantly better agreement
with observations. Encouragingly, these increases in Ia rate (> 10 times in
low-mass galaxies) do not significantly impact galaxy stellar masses and
morphologies: effective radii, axis ratios, and v/sigma remain largely
unaffected except for our most extreme rate models. We explore implications for
both [Fe/H] and [alpha/Fe] enrichment: metallicity-dependent Ia rate models can
improve agreement with observed stellar mass-metallicity relations in low-mass
galaxies. Our results demonstrate that a wide range of metallicity-dependent Ia
models are viable for galaxy formation and motivate future work in this area.


title:
Light Curve Model for Luminous Red Novae and Inferences about the Ejecta
  of Stellar Mergers

abstract:
  The process of unstable mass transfer in a stellar binary can result in
either a complete merger of the stars or successful removal of the donor
envelope leaving a surviving more compact binary. "Luminous red nova" (LRN) are
the class of optical transients believed to accompany such merger/common
envelope events. Past works typically model LRNe using analytic formulae for
supernova light curves which make assumptions (e.g., radiation dominated
ejecta, neglect of hydrogen recombination energy) not justified in stellar
mergers due to the lower velocities and specific thermal energy of the ejecta.
We present a one-dimensional model of LRN light curves, which accounts for
these effects. Consistent with observations, we find that LRNe typically
possess two light curve peaks, an early phase powered by initial thermal energy
of the hot, fastest ejecta layers and a later peak powered by hydrogen
recombination from the bulk of the ejecta. We apply our model to a sample of
LRNe to infer their ejecta properties (mass, velocity, and launching radius)
and compare them to the progenitor donor star properties from pre-transient
imaging. We define a maximum luminosity achievable for a given donor star in
the limit that the entire envelope is ejected, finding that several LRNe
violate this limit. Shock interaction between the ejecta and pre-dynamical
mass-loss, may provide an additional luminosity source to alleviate this
tension. Our model can also be applied to the merger of planets with stars or
stars with compact objects.


title: A Tale of Flavor Anomalies and the Origin of Neutrino Mass

abstract:
  One of the most important discoveries in particle physics is the observation
of non-zero neutrino masses, which dictates that the Standard Model (SM) is
incomplete. Moreover, several pieces of evidence of lepton flavor universality
violation (LFUV) gathered in the last few years hint towards physics beyond the
SM. TeV scale scalar leptoquarks (SLQs) are the leading candidates in
explaining these flavor anomalies in semileptonic charged and neutral current
B-decays, the muon, and the electron magnetic dipole moments that can also
participate in neutrino mass generation. In this work, we hypothesize that
neutrino masses and LFUV have a common new physics origin and classify the
simplest models consisting of SQLs. To this end, we propose a brand new
two-loop neutrino mass model that has the potential to resolve some of these
flavor anomalies and offer rich phenomenology to test the model in the ongoing
and future colliders.


title:
Measuring Cosmological Parameters with Type Ia Supernovae in redMaGiC
  galaxies

abstract:
  Current and future cosmological analyses with Type Ia Supernovae (SNe Ia)
face three critical challenges: i) measuring redshifts from the supernova or
its host galaxy; ii) classifying SNe without spectra; and iii) accounting for
correlations between the properties of SNe Ia and their host galaxies. We
present here a novel approach that addresses each challenge. In the context of
the Dark Energy Survey (DES), we analyze a SNIa sample with host galaxies in
the redMaGiC galaxy catalog, a selection of Luminous Red Galaxies. Photo-$z$
estimates for these galaxies are expected to be accurate to $\sigma_{\Delta
z/(1+z)}\sim0.02$. The DES-5YR photometrically classified SNIa sample contains
approximately 1600 SNe and 125 of these SNe are in redMaGiC galaxies. We
demonstrate that redMaGiC galaxies almost exclusively host SNe Ia, reducing
concerns with classification uncertainties. With this subsample, we find
similar Hubble scatter (to within $\sim0.01$ mag) using photometric redshifts
in place of spectroscopic redshifts. With detailed simulations, we show the
bias due to using photo-$z$s from redMaGiC host galaxies on the measurement of
the dark energy equation-of-state $w$ is up to $\Delta w \sim 0.01-0.02$. With
real data, we measure a difference in $w$ when using redMaGiC photometric
redshifts versus spectroscopic redshifts of $\Delta w = 0.005$. Finally, we
discuss how SNe in redMaGiC galaxies appear to be a more standardizable
population due to a weaker relation between color and luminosity ($\beta$)
compared to the DES-3YR population by $\sim5\sigma$; this finding is consistent
with predictions that redMaGiC galaxies exhibit lower reddening ratios
($\textrm{R}_\textrm{V}$) than the general population of SN host galaxies.
These results establish the feasibility of performing redMaGiC SN cosmology
with photometric survey data in the absence of spectroscopic data.


title: Non-Hermitian Squeezed Polarons

abstract:
  Recent experimental breakthroughs in non-Hermitian ultracold atomic lattices
have dangled tantalizing prospects in realizing exotic, hitherto unreported
many-body non-Hermitian quantum phenomena. In this work, we discover and
propose an experimental platform for a radically new non-Hermitian phenomenon
dubbed polaron squeezing. It is marked by a dipole-like accumulation of
fermions arising from an interacting impurity in a background of non-Hermitian
reciprocity-breaking hoppings. Unlike Hermitian polarons which are
symmetrically localized around impurities, non-Hermitian squeezed polarons
localize asymmetrically in the direction opposite to conventional non-Hermitian
pumping, and non-perturbatively modify the entire spectrum, despite having a
manifestly local profile. Also, unlike well-known topological or skin localized
states, squeezed polarons exist in the bulk, independently of boundary
conditions. We base our calculations on a proposed ultracold atomic setup where
a squeezed polaron can be readily detected and characterized by imaging the
spatial fermionic density.


title:
Resonant energy scales and local observables in the many-body localised
  phase

abstract:
  We formulate a theory for resonances in the many-body localised (MBL) phase
in terms of local observables. A key result is to show analytically that there
exist universal correlations between the matrix elements of local observables
and the many-body level spectrum. Moreover, we reveal how the matrix elements
encode the energy scales associated with resonance, and show that these
energies are power-law distributed. Our theoretical approach is to consider the
effect of varying a local field, which induces parametric dynamics of spectral
properties. We corroborate our results numerically using exact diagonalisation
in finite systems.


title:
Fakeons versus Lee-Wick ghosts: physical Pauli-Villars fields, finite
  QED and quantum gravity

abstract:
  We reconsider the Lee-Wick (LW) models and compare their properties to the
properties of the models that contain purely virtual particles. We argue
against the LW premise that unstable particles can be removed from the sets of
incoming and outgoing states in scattering processes. The removal leads to a
non-Hermitian classical limit, besides clashing with the observation of the
muon. If, on the other hand, all the states are included, the LW models have an
unbounded Hamiltonian or negative norms. Purely virtual particles, on the
contrary, lead to a Hermitian classical limit and are absent from the sets of
incoming and outgoing states without implications on the observation of
long-lived unstable particles. We give a vademecum to summarize the properties
of most options. We study a method to remove the LW ghosts only partially, by
saving the physical particles they contain. Specifically, we replace a LW ghost
with a certain superposition of a fakeon and an observable particle, and drop
only the former from the sets of the external states. The trick can be used to
make the Pauli-Villars fields consistent and observable, without sending their
masses to infinity, or build a finite QED, by tweaking the original Lee-Wick
construction. However, it has issues with general covariance, so it cannot be
applied as is to quantum gravity, where a manifestly covariant decomposition
requires the introduction of a massive spin 2 multiplet.


title: Adaptive time step control for infinitesimal multirate methods

abstract:
  Multirate methods have been used for decades to temporally evolve
initial-value problems in which different components evolve on distinct time
scales, and thus use of different step sizes for these components can result in
increased computational efficiency. Generally, such methods select these
different step sizes based on experimentation or stability considerations.
Meanwhile for problems that evolve on a single time scale, adaptivity
approaches that strive to control local temporal error are widely used to
achieve numerical results of a desired accuracy with minimal computational
effort, while alleviating the need for manual experimentation with different
time step sizes. However, there is a notable gap in the publication record on
the development of adaptive time-step controllers for multirate methods. In
this paper, we extend the single-rate controller work of Gustafsson (1994) to
the multirate method setting. Specifically, we develop controllers based on
polynomial approximations to the principal error functions for both the "fast"
and "slow" time scales within infinitesimal multirate (MRI) methods. We
additionally investigate a variety of approaches for estimating the errors
arising from each time scale within MRI methods. We then numerically evaluate
the proposed multirate controllers and error estimation strategies on a range
of multirate test problems, comparing their performance against an estimated
optimal performance. Through this work, we combine the most performant of these
approaches to arrive at a set of multirate adaptive time step controllers that
robustly achieve desired solution accuracy with minimal computational effort.


title: A Near Surface Temperature Model of Arrokoth

abstract:
  A near surface thermal model for Arrokoth is developed based on the recently
released $10^5$ facet model of the body. This thermal solution takes into
account Arrokoth's surface re-radiation back onto itself. The solution method
exploits Arrokoth's periodic orbital character to develop a thermal response
using a time-asymptotic solution method, which involves a Fourier transform
solution of the heat equation, an approach recently used by others. We display
detailed thermal solutions assuming that Arrokoth's near surface material's
thermal inertia ${\cal I} = $ 2.5 W/m$^{-2}$K$^{-1}$s$^{1/2}$. We predict that
at New Horizons' encounter with Arrokoth its encounter hemisphere surface
temperatures were $\sim$ 57-59 K in its polar regions, 30-40 K on its
equatorial zones, and 11-13 K for its winter hemisphere. Arrokoth's orbitally
averaged temperatures are around 30-35 K in its polar regions, and closer to 40
K near its equatorial zones. Thermal reradiation from the surrounding surface
amounts to less than 5\% of the total energy budget, while the total energy
ensconced into and exhumed out Arrokoth's interior via thermal conduction over
one orbit is about 0.5\% of the total energy budget. As a generalized
application of this thermal modeling together with other KBO origins
considerations, we favor the interpretation that New Horizons' REX instrument's
$29 \pm 5$K brightness temperature measurement is consistent with Arrokoth's
near surface material's being made of sub-to-few mm sized tholin-coated
amorphous \water ice grains with 1 W/m$^{-2}$K$^{-1}$s$^{1/2}$ $< {\cal I} <
$10-20 W/m$^{-2}$K$^{-1}$s$^{1/2}$, and which are characterized by an X-band
emissivity in the range 0.9 and 1.


title: Towards Quantum Gates with Wide Operating Margins

abstract:
  Scaling up quantum computing hardware is hindered by the narrow operating
margins of current quantum components. Here, we introduce a composite qubit and
gate scheme that achieves wide margins by use of transistor-like nonlinearities
to suppress the effects of both ambient noise and control signal imperfections.
This is accomplished by adiabatic deformation of subsystem codes based on
anti-commuting two-body interactions. We focus on a resource-effcient variation
that exploits biased noise and preserves bias under gate operation. As a proof
of concept, we present simulations of a superconducting circuit that
demonstrates core elements of the approach and discuss the challenges of
experimental implementation.


title:
Half-space stationary Kardar-Parisi-Zhang equation beyond the Brownian
  case

abstract:
  We study the Kardar-Parisi-Zhang equation on the half-line $x \geq 0$ with
Neumann type boundary condition. Stationary measures of the KPZ dynamics were
characterized in recent work: they depend on two parameters, the boundary
parameter $u$ of the dynamics, and the drift $-v$ of the initial condition at
infinity. We consider the fluctuations of the height field when the initial
condition is given by one of these stationary processes. At large time $t$, it
is natural to rescale parameters as $(u,v)=t^{-1/3}(a,b)$ to study the critical
region. In the special case $a+b=0$, treated in previous works, the stationary
process is simply Brownian. However, these Brownian stationary measures are
particularly relevant in the bound phase ($a<0$) but not in the unbound phase.
For instance, starting from the flat or droplet initial data, the height field
near the boundary converges to the stationary process with $a>0$ and $b=0$,
which is not Brownian. For $a+b\geqslant 0$, we determine exactly the large
time distribution $F_{a,b}^{\rm stat}$ of the height function $h(0,t)$. As an
application, we obtain the exact covariance of the height field in a half-line
at two times $1\ll t_1\ll t_2$ starting from stationary initial data, as well
as estimates, when starting from droplet initial data, in the limit $t_1/t_2\to
1$.

categories: cond-mat.stat-mech cond-mat.dis-nn math-ph math.MP math.PR


title: Charged Dark Matter in Supersymmetric Twin Higgs models

abstract:
  Supersymmetric Twin Higgs models ameliorate the fine-tuning of the
electroweak scale originating from the heavy scalar top partners required by
the non-discovery of them at the Large Hadron Collider. If the Lightest
Supersymmetric Particle resides in the twin sector, it may play the role of
dark matter even if it is charged under twin gauge interactions. We show that
the twin stau is a viable candidate for charged dark matter, even if the twin
electromagnetic gauge symmetry is unbroken, with thermal relic abundance that
naturally matches the observed dark matter abundance. A wide parameter space
satisfies all the experimental constraints including those on dark matter
self-interactions. Twin stau dark matter can be observed in future direct
detection experiments such as LUX-ZEPLIN. The stau has a mass in the range of
300-500 GeV, and in the minimal scenario, has a decay length long enough to be
observed as a disappearing track or a long-lived particle at the Large Hadron
Collider.


title:
MARS: A New Maximum Entropy-Regularized Strong Lensing Mass
  Reconstruction Method

abstract:
  Free-form strong-lensing (SL) mass reconstructions typically suffer from
overfitting, which manifest itself as false-positive small-scale fluctuations.
We present a new free-form MAximum-entropy ReconStruction (${\tt MARS}$) method
without the assumption that light traces mass (LTM). The ${\tt MARS}$ algorithm
enables us to achieve excellent convergence in source positions ~0.001$"$,
minimize spurious small-scale fluctuations, and provide a quasi-unique solution
independently of initial conditions. Our method is tested with the publicly
available synthetic SL data ${\tt FF-SIMS}$ and the comparison with the truth
shows that the reconstruction quality is on a par with those of the
best-performing LTM methods published in the literature, which have been
demonstrated to outperform the existing free-form methods. In terms of the
radial mass profile reconstruction, we achieve $<1$% agreements with the truth
for the regions constrained by the multiple images. Finally, we apply ${\tt
MARS}$ to A1689 and find that the cluster mass in the SL regime is dominated by
the primary halo centered on the brightest cluster galaxy and the weaker
secondary halo also coincident with the bright cluster member ~160 kpc
northeast. Within the SL field, the A1689 radial profile is well-described by a
Navarro-Frenk-White (NFW) profile with $c_{200}=5.53\pm0.77$ and
$r_s=538^{+90}_{-100}$ kpc and we find no evidence that A1689 is
over-concentrated.


title:
Effects of magnetic and non-magnetic doping on the vortex lattice in
  MgB$_2$

abstract:
  Using small-angle neutron scattering we have studied the vortex lattice in
superconducting MgB$_2$ with the magnetic field applied along the $c$-axis,
doped with either manganese or carbon to achieve a similar suppression of the
critical temperature. For Mn-doping, the vortex lattice phase diagram remains
qualitatively similar to that of pure MgB$_2$, undergoing a field-and
temperature-driven $30^{\circ}$ rotation transition, indicating only a modest
effect on the vortex-vortex interaction. In contrast, the vortex lattice
rotation transition is completely suppressed in the C-doped case, likely due to
a change in the electronic structure which affects the two-band/two-gap nature
of superconductivity in MgB2. The vortex lattice longitudinal correlation
length shows the opposite behavior, remaining roughly unchanged between pure
and C-doped MgB$_2$ while it is significantly reduced in the Mn-doped case.
However, the extensive vortex lattice metastability and related activated
behavior, observed in conjunction with the vortex lattice transition in pure
MgB$_2$, is also seen in the Mn doped sample. This shows that the vortex
lattice disordering is not associated with a substantially increased vortex
pinning.


title:
Noncommutative solutions to Zamolodchikov's tetrahedron equation and
  matrix six-factorisation problems

abstract:
  It is known that the local Yang--Baxter equation is a generator of potential
solutions to Zamolodchikov's tetrahedron equation. In this paper, we show under
which additional conditions the solutions to the local Yang--Baxter equation
are tetrahedron maps, namely solutions to the set-theoretical tetrahedron
equation. This is exceptionally useful when one wants to prove that
noncommutative maps satisfy the Zamolodchikov's tetrahedron equation. We
construct new noncommutative maps and we prove that they possess the
tetrahedron property. Moreover, by employing Darboux transformations with
noncommutative variables, we derive noncommutative tetrahedron maps. In
particular, we derive a noncommutative nonlinear Schr\"odinger type of
tetrahedron map which can be restricted to a noncommutative version of
Sergeev's map on invariant leaves. We prove that these maps are tetrahedron
maps.


title: CaMEL: Mean Teacher Learning for Image Captioning

abstract:
  Describing images in natural language is a fundamental step towards the
automatic modeling of connections between the visual and textual modalities. In
this paper we present CaMEL, a novel Transformer-based architecture for image
captioning. Our proposed approach leverages the interaction of two
interconnected language models that learn from each other during the training
phase. The interplay between the two language models follows a mean teacher
learning paradigm with knowledge distillation. Experimentally, we assess the
effectiveness of the proposed solution on the COCO dataset and in conjunction
with different visual feature extractors. When comparing with existing
proposals, we demonstrate that our model provides state-of-the-art caption
quality with a significantly reduced number of parameters. According to the
CIDEr metric, we obtain a new state of the art on COCO when training without
using external data. The source code and trained models are publicly available
at: https://github.com/aimagelab/camel.


title:
Existence and non-existence of global solutions for a heat equation with
  degenerate coefficients

abstract:
  In this paper, we will study the following parabolic problem $u_t -
div(\omega(x) \nabla u)= h(t) f(u) + l(t) g(u)$ with non-negative initial
conditions pertaining to $C_b(\mathbb{R}^N)$, where the weight $\omega$ is an
appropriate function that belongs to the Munckenhoupt class $A_{1 +
\frac{2}{N}}$ and the functions $f$, $g$, $h$ and $l$ are non-negative and
continuous. The main goal is to establish of global and non-global existence of
non-negative solutions. In addition, to present the particular case when $h(t)
\sim t^r ~~ (r>-1)$, $l(t) \sim t^s ~~ (s>-1)$, $f(u) = u^p$ and $g(u)=
(1+u)[\ln(1+u)]^p,$ we obtain both the so-called Fujita's exponent and the
second critical exponent in the sense of Lee and Ni \cite{Lee-Ni}. Our results
extend those obtained by Fujishima et al. \cite{Fujish} who worked when
$h(t)=1$, $l(t)=0$ and $f(u)=u^p $.


title:
Demand and Price Fluctuations Effect on Risk and Profit of Single and
  Clustered Microgrids during COVID-19 Pandemic

abstract:
  COVID19s widespread distribution is wreaking havoc on peoples lives all over
the world. This pandemic has also had a significant impact on energy
consumption. Its influence can be seen in the power systems operation and the
market as well. The power consumers habits and demand curves have been changed
at a breakneck pace. In this work, a one year mixed integer programming (MIP)
problem has been developed to compare the power consumption between 2019 and
2020 in the United States as an example regarding the COVID19 pandemic effect
in order to better prepare for possible similar future events. 100 percent
renewable single microgrids (SMGs) are studied using wind turbines and
photovoltaics. Batteries are also employed since it is inevitable when the
system uses renewables. Additionally, it is possible for the SMGs to trade
power with the main grid as needed. The effect of the SMGs clustering to form
the multi microgrids (MMGs) is also considered. In order to investigate the
risk of the system during the COVID19 and formation of MMG, downside risk
constraints are applied to the proposed model. Furthermore, a stylized short
run consumers demand model is proposed, using elasticity and assessed responses
regarding the average household consumption for households during on peak and
off peak periods. The simulation results show that COVID19 generally reduces
the demand, increases the profit of the system, and decreases the economic risk
of the power systems operation. Moreover, SMGs clustering to organize MMG
dramatically enhances the profit of the system as well as improves the risk
level of the system.


title:
Misalignment of terrestrial circumbinary planets as an indicator of
  their formation mechanism

abstract:
  Circumbinary gas disks are often observed to be misaligned to the binary
orbit suggesting that planet formation may proceed in a misaligned disk. With
N-body simulations we consider the formation of circumbinary terrestrial
planets from a particle disk that is initially misaligned. We find that if
terrestrial planets form in this way, in the absence of gas, they can only form
close to coplanar or close to polar to the binary orbit. Planets around a
circular binary form coplanar while planets around an eccentric binary can form
coplanar or polar depending on the initial disk misalignment and the binary
eccentricity. The more massive a terrestrial planet is, the more aligned it is
(to coplanar or polar) since it has undergone more mergers that lead on average
to smaller misalignment angles. Nodal precession of particle disks with very
large initial inclinations lead to high mutual inclinations between the
particles. This produces high relative velocities between particles that leads
to mass ejections that can completely inhibit planet formation. Misaligned
terrestrial circumbinary planets may be able to form in the presence of a
misaligned circumbinary gas disk that may help to nodally align the particle
orbits and maintain the inclination of the planets during their formation.


title: Chandra Follow-up Observations of Swift-BAT-selected AGNs II

abstract:
  We present the combined Chandra and Swift-BAT spectral analysis of nine
low-redshift (z <= 0.10), candidate heavily obscured active galactic nuclei
(AGN) selected from the Swift-BAT 150-month catalog. We located soft (1-10 keV)
X-ray counterparts to these BAT sources and joint fit their spectra with
physically motivated models.The spectral analysis in the 1-150 keV energy band
determined that all sources are obscured, with a line-of-sight column density
NH >= 10^22 cm^-2 at a 90% confidence level. Four of these sources show
significant obscuration with NH >= 10^23 cm^-2 and two additional sources are
candidate Compton-thick Active Galactic Nuclei (CT-AGNs) with NH >= 10^24
cm^-2.These two sources, 2MASX J02051994-0233055 and IRAS 11058-1131, are the
latest addition to the previous 3 CT-AGN candidates found using our strategy
for soft X-ray follow-up of BAT sources. In here we present the results of our
methodology so far, and analyze the effectiveness of applying different
selection criteria to discover CT-AGN in the local Universe. Our selection
criteria has a ~20% success rate of discovering heavily obscured AGN whose CT
nature is confirmed by follow-up NuSTAR observations. This is much higher than
the ~5% found in blind surveys.


title:
Finite Unitary Rings $R$ all Whose Subrings, except $R$ Itself, Have
  Solvable Groups of Units

abstract:
  Let $R$ be a finite unitary ring with $R^*$ a non-solvable group, but such
that for all proper unitary subrings $S$ of $R$, $S^*$ is a solvable group. We
classify such rings. Moreover we show that any ring with a non-solvable group
of units and of order $p^n$, $n\leq 5$, is of that form and we also analyze the
structure of rings of order $p^6$.


title:
Many-body localization and delocalization dynamics in the thermodynamic
  limit

abstract:
  Disordered quantum systems undergoing a many-body localization (MBL)
transition fail to reach thermal equilibrium under their own dynamics.
Distinguishing between asymptotically localized or delocalized dynamics based
on numerical results is however nontrivial due to finite-size effects.
Numerical linked cluster expansions (NLCE) provide a means to tackle quantum
systems directly in the thermodynamic limit, but are challenging for models
without translational invariance. Here, we demonstrate that NLCE provide a
powerful tool to explore MBL by simulating quench dynamics in disordered
spin-$1/2$ two-leg ladders and Fermi-Hubbard chains. Combining NLCE with an
efficient real-time evolution of pure states, we obtain converged results for
the decay of the imbalance on long time scales and show that, especially for
intermediate disorder below the putative MBL transition, NLCE outperform direct
simulations of finite systems with open or periodic boundaries. Furthermore,
while spin is delocalized even in strongly disorderd Hubbard chains with frozen
charge, we unveil that an additional tilted potential leads to a drastic
slowdown of the spin imbalance and nonergodic behavior on accessible times. Our
work sheds light on MBL in systems beyond the well-studied disordered
Heisenberg chain and emphasizes the usefulness of NLCE for this purpose.

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


title: Scattering Amplitudes and The Cotton Double Copy

abstract:
  We construct classical curvature spinors in topologically massive gauge
theory and topologically massive gravity, expressed in terms of massive
three-particle amplitudes. We show that when the amplitudes double copy, the
curvature spinors satisfy the Cotton double copy, the three-dimensional cousin
of the Weyl double copy. Furthermore, we show that under certain circumstances
the Cotton double copy can be derived via a dimensional reduction of the Weyl
double copy.


title: Electromechanical coupling in Yb-substituted III-V nitride alloys

abstract:
  Yb-substitution induced enhancement for electromechanical coupling in
wurtzite III-V nitrides is studied via theoretical calculations and
experiments. The substitution induced local strain and mechanical softening
enhanced electromechanical coupling. Interestingly, mechanical softening
induced by Yb substitution shows less dependence on the parent AlN and GaN,
which is considered to originate from the Yb-Yb pair interaction. The
difference in enhancement of electromechanical coupling for the alloys mainly
comes from the enhanced piezoelectric response. Spontaneous polarization
induced by the strain plays a key role in enhancing the piezoelectric response,
which can be improved by selecting the wurtzite structure with an optimized
internal parameter. Additionally, when the substitutional element has
significantly different ionic size from the host cation, the piezoelectric
response due to the internal strain is considerably enhanced. This can serve as
a simple guideline to identify alloying components in a search for a massive
increase in electromechanical coupling.


title: Localizing non-linear ${\cal N}=(2,2)$ sigma model on $S^2$

abstract:
  We present a systematic study of ${\cal N}=(2,2)$ supersymmetric non-linear
sigma models on $S^2$ with the target being a K\"ahler manifold. We discuss
their reformulation in terms of cohomological field theory. In the
cohomological formulation we use a novel version of 2D self-duality which
involves a $U(1)$ action on $S^2$. In addition to the generic model we discuss
the theory with target space equivariance corresponding to a supersymmetric
sigma model coupled to a non-dynamical supersymmetric background gauge
multiplet. We discuss the localization locus and perform a one-loop calculation
around the constant maps. We argue that the theory can be reduced to some
exotic model over the moduli space of holomorphic disks.


title:
Flexible Skylines: Customizing Skyline Queries Catching Desired
  Preferences

abstract:
  The techniques most extensively used to retrieve interesting data from
data-sets are the Skyline and the Top-k queries. Sadly, they are not enough for
facing modern problems, so the needing of something more usable and reliable
has come. In this survey we are going to explore Flexible Skylines which are
proposed to overcame the old fashion techniques' problems by extending the
concept of dominance. After, we are going to compare this approach with the old
and new ones evaluating pros and cons. Finally, we will see some interesting
applications.


title: Holographic Bubbles with Jecco: Expanding, Collapsing and Critical

abstract:
  Cosmological phase transitions can proceed via the nucleation of bubbles that
subsequently expand and collide. The resulting gravitational wave spectrum
depends crucially on the properties of these bubbles. We extend our previous
holographic work on planar bubbles to circular bubbles in a strongly-coupled,
non-Abelian, four-dimensional gauge theory. This extension brings about two new
physical properties. First, the existence of a critical bubble, which we
determine. Second, the bubble profile at late times exhibits a richer
self-similar structure, which we verify. These results require a new 3+1
evolution code called Jecco that solves the Einstein equations in the
characteristic formulation in asymptotically AdS spaces. Jecco is written in
the Julia programming language and is freely available. We present an outline
of the code and the tests performed to assess its robustness and performance.


title:
Observation of ultrabroadband striped space-time surface plasmon
  polaritons

abstract:
  Because surface plasmon polaritons (SPPs) are surface waves characterized by
one free transverse dimension, the only monochromatic diffraction-free spatial
profiles for SPPs are cosine and Airy waves. Pulsed SPP wave packets have been
recently formulated that are propagation-invariant and localized in the
in-plane dimensions by virtue of a tight spectral association between their
spatial and temporal frequencies, which have thus been dubbed `space-time' (ST)
SPPs. Because of the spatio-temporal spectral structure unique to ST-SPPs, the
optimal launching strategy of such novel plasmonic field configurations remains
an open question. We present here a critical step towards realizing ST-SPPs by
reporting observations of ultrabroadband striped ST-SPPs. These are SPPs in
which each wavelength travels at a prescribed angle with respect to the
propagation axis to produce a periodic (striped) transverse spatial profile
that is diffraction-free. We start with a free-space ST wave packet that is
coupled to a ST-SPP at a gold-dielectric interface, and unambiguously identify
the ST-SPP via an axial beating detected in two-photon fluorescence produced by
the superposition of incident ST wave packet and the excited surface-bound
ST-SPP. These results highlight a viable approach for efficient and reliable
coupling to ST-SPPs, and thus represent the first crucial step towards
realization of the full potential of ST-SPPs for plasmonic sensing and imaging.


title: Self-Evolutionary Clustering

abstract:
  Deep clustering outperforms conventional clustering by mutually promoting
representation learning and cluster assignment. However, most existing deep
clustering methods suffer from two major drawbacks. First, most cluster
assignment methods are based on simple distance comparison and highly dependent
on the target distribution generated by a handcrafted nonlinear mapping. These
facts largely limit the possible performance that deep clustering methods can
reach. Second, the clustering results can be easily guided towards wrong
direction by the misassigned samples in each cluster. The existing deep
clustering methods are incapable of discriminating such samples. To address
these issues, a novel modular Self-Evolutionary Clustering (Self-EvoC)
framework is constructed, which boosts the clustering performance by
classification in a self-supervised manner. Fuzzy theory is used to score the
sample membership with probability which evaluates the intermediate clustering
result certainty of each sample. Based on which, the most reliable samples can
be selected and augmented. The augmented data are employed to fine-tune an
off-the-shelf deep network classifier with the labels from the clustering,
which results in a model to generate the target distribution. The proposed
framework can efficiently discriminate sample outliers and generate better
target distribution with the assistance of self-supervised classifier.
Extensive experiments indicate that the Self-EvoC remarkably outperforms
state-of-the-art deep clustering methods on three benchmark datasets.


title:
Accelerating Primal-dual Methods for Regularized Markov Decision
  Processes

abstract:
  Entropy regularized Markov decision processes have been widely used in
reinforcement learning. This paper is concerned with the primal-dual
formulation of the entropy regularized problems. Standard first-order methods
suffer from slow convergence due to the lack of strict convexity and concavity.
To address this issue, we first introduce a new quadratically convexified
primal-dual formulation. The natural gradient ascent descent of the new
formulation enjoys global convergence guarantee and exponential convergence
rate. We also propose a new interpolating metric that further accelerates the
convergence significantly. Numerical results are provided to demonstrate the
performance of the proposed methods under multiple settings.


title:
Detection of period-spacing patterns due to the gravity modes of
  rotating dwarfs in the TESS southern continuous viewing zone

abstract:
  Context: the theory of stellar evolution presents shortcomings when
confronted with asteroseismic probes of interior physical properties. The
differences between observations and theory are often great because stellar
models have mainly been calibrated from observables connected to the surface of
stars. Period-spacing patterns caused by gravity modes are a particularly
powerful asteroseismic tool that are useful for probing the near-core rotation
and mixing of chemical elements in main-sequence stars with convective cores.
Aims: we aim to compose a catalog of intermediate-mass stars in the TESS
southern continuous viewing zone to reveal period-spacing patterns caused by
gravity modes for use in future asteroseismic modeling. Methods: TESS full
frame images were inspected to select stars of intermediate- and high-mass
using color-magnitude criteria. Light curves were extracted from custom masks
per star, adopting stringent constraints on the aperture masks and
contamination. The extracted light curves were subject to iterative
prewhitening to detect gravity modes. We developed a method based on the
assumption that period spacings are an approximately linear function of the
mode periods to build a template pattern. This template was used to extract the
patterns and their bootstrap uncertainties. Results: our TESS catalog of
high-quality period-spacing patterns is the first of its kind and contains 140
gravity-mode patterns in 106 Gamma Doradus stars and 2 slowly pulsating B-type
stars. Half of these patterns contain 7 or more measured mode periods and the
longest pattern contains 20 modes. We provide the community with a convenient
software tool to search for period-spacing patterns and to process the
extracted light curves. Conclusions: our catalog offers a fruitful starting
point for future gravity-mode asteroseismology of rotating dwarfs with
convective cores in the southern hemisphere.


title:
Data-Driven Traffic Assignment: A Novel Approach for Learning Traffic
  Flow Patterns Using a Graph Convolutional Neural Network

abstract:
  We present a novel data-driven approach of learning traffic flow patterns of
a transportation network given that many instances of origin to destination
(OD) travel demand and link flows of the network are available. Instead of
estimating traffic flow patterns assuming certain user behavior (e.g., user
equilibrium or system optimal), here we explore the idea of learning those flow
patterns directly from the data. To implement this idea, we have formulated the
traffic-assignment problem as a data-driven learning problem and developed a
neural network-based framework known as Graph Convolutional Neural Network
(GCNN) to solve it. The proposed framework represents the transportation
network and OD demand in an efficient way and utilizes the diffusion process of
multiple OD demands from nodes to links. We validate the solutions of the model
against analytical solutions generated from running static user
equilibrium-based traffic assignments over Sioux Falls and East Massachusetts
networks. The validation result shows that the implemented GCNN model can learn
the flow patterns very well with less than 2% mean absolute difference between
the actual and estimated link flows for both networks under varying congested
conditions. When the training of the model is complete, it can instantly
determine the traffic flows of a large-scale network. Hence this approach can
overcome the challenges of deploying traffic assignment models over large-scale
networks and open new directions of research in data-driven network modeling.


title: Learning from Radiation at a Very High Energy Lepton Collider

abstract:
  We study the potential of lepton collisions with about $10\text{ TeV}$ center
of mass energy to probe Electroweak, Higgs and Top short-distance physics at
the $100\text{ TeV}$ scale, pointing out the interplay with the long-distance
($100\text{ GeV}$) phenomenon of Electroweak radiation. On one hand, we find
that sufficiently accurate theoretical predictions require the resummed
inclusion of radiation effects, which we perform at the double logarithmic
order. On the other hand, we notice that short-distance physics does influence
the emission of Electroweak radiation. Therefore the investigation of the
radiation pattern can enhance the sensitivity to new short-distance physical
laws. We illustrate these aspects by studying Effective Field Theory contact
interactions in di-fermion and di-boson production, and comparing cross-section
measurements that require or that exclude the emission of massive Electroweak
bosons. The combination of the two types of measurements is found to enhance
the sensitivity to the new interactions. Based on these results, we perform
sensitivity projections to Higgs and Top Compositeness and to minimal $Z'$ new
physics scenarios at future muon colliders.


title:
General weak segregation theory with an application to monodisperse
  semi-flexible diblock copolymers

abstract:
  A general theory has been developed for a polydisperse semi-flexible
multi-block copolymer melt. Using the Bawendi-Freed approach to model
semi-flexible chains an expression for the Landau free energy is derived in the
weak segregation regime which includes the density and orientation
order-parameters. The orientation order-parameter is described in the smectic
phase and in more complicated structures such as the hexagonal phase. The
Landau free energy contains contributions of two kinds of interactions. The
first kind is the Flory- Huggins interaction which describes the
incompatibility of chemically different blocks and may induce microphase
separation. The second kind is the Maier- Saupe interaction which may induce
nematic ordening. In the framework of the weak segragation limit the Landau
theory allows to predict phase structures in the melt as a function of the
composition, persistence length and the strength of the Flory-Huggins and
Maier-Saupe interaction. The general theory is applied to a simple system of
monodisperse semi-flexible diblock copolymers. In several phase diagrams a
number of possible phase structures is predicted such as the bcc, hexagonal,
smectic-A, smectic-C and nematic phase. The infuence of the Maier-Saupe
interaction on the microphase structure is thoroughly discussed.


title: Results on spin sum rules and polarizabilities at low $Q^2$

abstract:
  We report on recently published experimental results on spin sum rules, and
particularly on the generalized spin polarizabilities $\gamma_0(Q^2)$ (for both
the proton and neutron) and $\delta_\mathrm{LT}(Q^2)$ (for the neutron). The
data were taken at Jefferson Lab in Hall A by experiment E97110 (neutron) and
in Hall B by experiments E03006 and E05111 (proton and deuteron, respectively).
The experiments covered the very low $Q^2$ domain, down to $Q^2 \simeq 0.02$
GeV$^2$. This is well into the domain where Chiral Effective Field Theory
($\chi$EFT) predictions should be valid. Some measured observables agree with
the state-of-the-art $\chi$EFT predictions but others are in tension, including
$\delta_\mathrm{LT}^n(Q^2)$ which $\chi$EFT prediction was expected to be
robust. This suggests that $\chi$EFT does not yet consistently describe nucleon
spin observables, even at the very low $Q^2$ covered by the experiments.


title: Breather modes of fully nonlinear mass-in-mass chains

abstract:
  We propose a model for a chain of particles coupled by nonlinear springs in
which each mass has an internal mass and all interactions are assumed to be
nonlinear. We show how to construct an asymptotic solution of this system using
multiple timescales, the systematic solution of coupled equations by repeated
application of a consistency condition. Our results show that for some
combinations of nonlinearity the dynamics are governed by the NLS as in the
more usual mass-in-mass chains with linear interactions between inner and outer
masses. However, when both nonlinearities have quadratic components, we show
that the asymptotic reduction results in a Ginzburg-Landau equation instead of
NLS.


title:
Quantifying Uncertainty for Temporal Motif Estimation in Graph Streams
  under Sampling

abstract:
  Dynamic networks, a.k.a. graph streams, consist of a set of vertices and a
collection of timestamped interaction events (i.e., temporal edges) between
vertices. Temporal motifs are defined as classes of (small) isomorphic induced
subgraphs on graph streams, considering both edge ordering and duration. As
with motifs in static networks, temporal motifs are the fundamental building
blocks for temporal structures in dynamic networks. Several methods have been
designed to count the occurrences of temporal motifs in graph streams, with
recent work focusing on estimating the count under various sampling schemes
along with concentration properties. However, little attention has been given
to the problem of uncertainty quantification and the asymptotic statistical
properties for such count estimators. In this work, we establish the
consistency and the asymptotic normality of a certain Horvitz-Thompson type of
estimator in an edge sampling framework for deterministic graph streams, which
can be used to construct confidence intervals and conduct hypothesis testing
for the temporal motif count under sampling. We also establish similar results
under an analogous stochastic model. Our results are relevant to a wide range
of applications in social, communication, biological, and brain networks, for
tasks involving pattern discovery.


title:
Complementary collider and astrophysical probes of multi-component Dark
  Matter

abstract:
  We study a new physics scenario with two inert and one active scalar
doublets, hence a 3-Higgs Doublet Model (3HDM). We impose a $Z_2 \times Z'_2$
symmetry onto such a 3HDM with one inert doublet odd under the $Z_2$
transformation and the other odd under the $Z'_2$ one. Such a construction
leads to a two-component Dark Matter (DM) model. It has been shown that, when
there is a sufficient mass difference between the two DM candidates, it is
possible to probe the light DM candidate in the nuclear recoil energy in direct
detection experiments and the heavy DM component in the photon flux in indirect
detection experiments. With the DM masses at the electroweak scale, we show
that, independently of astrophysical probes, this model feature can be tested
at the Large Hadron Collider via scalar cascade decays in $2 \ell +
\cancel{E}_T$ final states. We study several observable distributions whose
shapes hint at the presence of the two different DM candidates.


title: Graph Coloring and Semidefinite Rank

abstract:
  This paper considers the interplay between semidefinite programming, matrix
rank, and graph coloring. Karger, Motwani, and Sudan \cite{KMS98} give a vector
program for which a coloring of the graph can be encoded as a semidefinite
matrix of low rank. By complementary slackness conditions of semidefinite
programming, if an optimal dual solution has sufficiently high rank, any
optimal primal solution must have low rank. We attempt to characterize graphs
for which we can show that the corresponding dual optimal solution must have
sufficiently high rank. In the case of the original Karger, Motwani, and Sudan
vector program, we show that any graph which is a $k$-tree has sufficiently
high dual rank, and we can extract the coloring from the corresponding low-rank
primal solution. We can also show that if the graph is not uniquely colorable,
then no sufficiently high rank dual optimal solution can exist. This allows us
to completely characterize the planar graphs for which dual optimal solutions
have sufficiently high dual rank. We then modify the semidefinite program to
have an objective function with costs, and explore when we can create a cost
function whose optimal dual solution has sufficiently high rank. We show that
it is always possible to construct such a cost function given the graph
coloring. The construction of the cost function gives rise to a heuristic for
graph coloring which we show works well in the case of planar graphs. Our
research was motivated by the Colin de Verdi\`ere graph invariant
\cite{CDV90}(and a corresponding conjecture of Colin de Verdi\`ere), in which
matrices that have some similarities to the dual feasible matrices must have
high rank in the case that graphs are of a certain type. We explore the
connection between the conjecture and the rank of the dual solutions.


title: Probing quantum devices with radio-frequency reflectometry

abstract:
  Many important phenomena in quantum devices are dynamic, meaning that they
cannot be studied using time-averaged measurements alone. Experiments that
measure such transient effects are collectively known as fast readout. One of
the most useful techniques in fast electrical readout is radio-frequency
reflectometry, which can measure changes in impedance (both resistive and
reactive) even when their duration is extremely short, down to a microsecond or
less. Examples of reflectometry experiments, some of which have been realised
and others so far only proposed, include projective measurements of qubits and
Majorana devices for quantum computing, real-time measurements of mechanical
motion and detection of non-equilibrium temperature fluctuations. However, all
of these experiments must overcome the central challenge of fast readout: the
large mismatch between the typical impedance of quantum devices (set by the
resistance quantum) and of transmission lines (set by the impedance of free
space). Here, we review the physical principles of radio-frequency
reflectometry and its close cousins, measurements of radio-frequency
transmission and emission. We explain how to optimise the speed and sensitivity
of a radio-frequency measurement, and how to incorporate new tools such as
superconducting circuit elements and quantum-limited amplifiers into advanced
radio-frequency experiments. Our aim is three-fold: to introduce the readers to
the technique, to review the advances to date and to motivate new experiments
in fast quantum device dynamics. Our intended audience includes
experimentalists in the field of quantum electronics who want to implement
radio-frequency experiments or improve them, together with physicists in
related fields who want to understand how the most important radio-frequency
measurements work.


title:
Personalized PATE: Differential Privacy for Machine Learning with
  Individual Privacy Guarantees

abstract:
  Applying machine learning (ML) to sensitive domains requires privacy
protection of the underlying training data through formal privacy frameworks,
such as differential privacy (DP). Yet, usually, the privacy of the training
data comes at the costs of the resulting ML models' utility. One reason for
this is that DP uses one homogeneous privacy budget epsilon for all training
data points, which has to align with the strictest privacy requirement
encountered among all data holders. In practice, different data holders might
have different privacy requirements and data points of data holders with lower
requirements could potentially contribute more information to the training
process of the ML models. To account for this possibility, we propose three
novel methods that extend the DP framework Private Aggregation of Teacher
Ensembles (PATE) to support training an ML model with different personalized
privacy guarantees within the training data. We formally describe the methods,
provide theoretical analyses of their privacy bounds, and experimentally
evaluate their effect on the final model's utility at the example of the MNIST
and Adult income datasets. Our experiments show that our personalized privacy
methods yield higher accuracy models than the non-personalized baseline.
Thereby, our methods can improve the privacy-utility trade-off in scenarios in
which different data holders consent to contribute their sensitive data at
different privacy levels.


title: The Oscura Experiment

abstract:
  The Oscura experiment will lead the search for low-mass dark matter particles
using a very large array of novel silicon Charge Coupled Devices (CCDs) with a
threshold of two electrons and with a total exposure of 30 kg-yr. The R&D
effort, which began in FY20, is currently entering the design phase with the
goal of being ready to start construction in late 2024. Oscura will have
unprecedented sensitivity to sub-GeV dark matter particles that interact with
electrons, probing dark matter-electron scattering for masses down to 500 keV
and dark matter being absorbed by electrons for masses down to 1 eV. The Oscura
R&D effort has made some significant progress on the main technical challenges
of the experiment, of which the most significant are engaging new foundries for
the fabrication of the CCD sensors, developing a cold readout solution, and
understanding the experimental backgrounds.


title:
FRB 121102: drastic changes in the burst polarization contrasts with the
  stability of the persistent emission

abstract:
  We study milliarcsecond-scale properties of the persistent radio counterpart
to FRB 121102 and investigate the spectro-polarimetric properties of a bright
burst. For the former, we use European VLBI Network (EVN) observations in 2017
at 1.7 and 4.8 GHz. For the latter, we re-analyse the 1.7-GHz data from the
100-m Effelseberg telescope taken in 2016. These observations predate other
polarimetric studies of FRB 121102, and yield the highest burst Faraday
rotation measure (RM) to date, RM = 1.27*10^5 rad m^-2, consistent with the
decreasing RM trend. The fractional polarization of the burst emission is 15%
at 1.7 GHz. This can be reconciled with the high fractional polarization at
higher frequencies if the Faraday width of the burst environment is 150 rad
m^-2 - a bare 0.1% of the total Faraday rotation. The width may originate from
minor non-uniformities in the Faraday screen, or from effects in the emitting
region itself. The upper limit on the persistent source size is 1 pc, barely
consistent with a young supernova (SN) scenario. The flux variability limit of
<10% is not in favor of the young SN scenario, and challenges other
interpretations as well. The fractional polarization of the faint persistent
source is constrained at <25% at 4.8 GHz ruling out a common origin with the
highly polarized individual bursts.


title:
Making Data Tangible: A Cross-disciplinary Design Space for Data
  Physicalization

abstract:
  Designing a data physicalization requires a myriad of different
considerations. Despite the cross-disciplinary nature of these considerations,
research currently lacks a synthesis across the different communities data
physicalization sits upon, including their approaches, theories, and even
terminologies. To bridge these communities synergistically, we present a design
space that describes and analyzes physicalizations according to three facets:
context (end-user considerations), structure (the physical structure of the
artifact), and interactions (interactions with both the artifact and data). We
construct this design space through a systematic review of 47 physicalizations
and analyze the interrelationships of key factors when designing a
physicalization. This design space cross-pollinates knowledge from relevant HCI
communities, providing a cohesive overview of what designers should consider
when creating a data physicalization while suggesting new design possibilities.
We analyze the design decisions present in current physicalizations, discuss
emerging trends, and identify underlying open challenges.


title:
Multi-dimensional Besicovitch almost periodic type functions and
  applications

abstract:
  In this paper, we analyze multi-dimensional Besicovitch almost periodic type
functions. We clarify the main structural properties for the introduced classes
of Besicovitch almost periodic type functions, explore the notion of
Besicovitch-Doss almost periodicity in the multi-dimensional setting, and
provide some applications of our results to the abstract Volterra
integro-differential equations and the partial differential equations.


title: Non-Volatile Memory Accelerated Posterior Estimation

abstract:
  Bayesian inference allows machine learning models to express uncertainty.
Current machine learning models use only a single learnable parameter
combination when making predictions, and as a result are highly overconfident
when their predictions are wrong. To use more learnable parameter combinations
efficiently, these samples must be drawn from the posterior distribution.
Unfortunately computing the posterior directly is infeasible, so often
researchers approximate it with a well known distribution such as a Gaussian.
In this paper, we show that through the use of high-capacity persistent
storage, models whose posterior distribution was too big to approximate are now
feasible, leading to improved predictions in downstream tasks.


title:
Semi-Implicit Hybrid Gradient Methods with Application to Adversarial
  Robustness

abstract:
  Adversarial examples, crafted by adding imperceptible perturbations to
natural inputs, can easily fool deep neural networks (DNNs). One of the most
successful methods for training adversarially robust DNNs is solving a
nonconvex-nonconcave minimax problem with an adversarial training (AT)
algorithm. However, among the many AT algorithms, only Dynamic AT (DAT) and You
Only Propagate Once (YOPO) guarantee convergence to a stationary point. In this
work, we generalize the stochastic primal-dual hybrid gradient algorithm to
develop semi-implicit hybrid gradient methods (SI-HGs) for finding stationary
points of nonconvex-nonconcave minimax problems. SI-HGs have the convergence
rate $O(1/K)$, which improves upon the rate $O(1/K^{1/2})$ of DAT and YOPO. We
devise a practical variant of SI-HGs, and show that it outperforms other AT
algorithms in terms of convergence speed and robustness.


title: Standard Model prediction for paramagnetic EDMs

abstract:
  Standard Model $CP$ violation associated with the phase of the
Cabibbo-Kobayashi-Maskawa quark mixing matrix is known to give small answers
for the EDM observables. Moreover, predictions for the EDMs of neutrons and
diamagnetic atoms suffer from considerable uncertainties. We point out that the
$CP$-violating observables associated with the electron spin (paramagnetic
EDMs) are dominated by the combination of the electroweak penguin diagrams and
$\Delta I =1/2$ weak transitions in the baryon sector, and are calculable
within chiral perturbation theory. The predicted size of the semileptonic
operator $C_S$ is $7\times 10^{-16}$ which corresponds to the equivalent
electron EDM $d_e^{\rm eq} = 1.0 \times 10^{-35}e\,{\rm cm}$. While still far
from the current observational limits, this result is three orders of magnitude
larger than previously believed.


title: A Probabilistic Approach to The Perfect Sum Problem

abstract:
  The subset sum problem is known to be an NP-hard problem in the field of
computer science with the fastest known approach having a run-time complexity
of $O(2^{0.3113n})$. A modified version of this problem is known as the perfect
sum problem and extends the subset sum idea further. This extension results in
additional complexity, making it difficult to compute for a large input. In
this paper, I propose a probabilistic approach which approximates the solution
to the perfect sum problem by approximating the distribution of potential sums.
Since this problem is an extension of the subset sum, our approximation also
grants some probabilistic insight into the solution for the subset sum problem.
We harness distributional approximations to model the number of subsets which
sum to a certain size. These distributional approximations are formulated in
two ways: using bounds to justify normal approximation, and approximating the
empirical distribution via density estimation. These approximations can be
computed in $O(n)$ complexity, and can increase in accuracy with the size of
the input data making it useful for large-scale combinatorial problems. Code is
available at https://github.com/KristofPusztai/PerfectSum.


title:
Virial-like Thermodynamic Uncertainty Relation in the Tight-Binding
  Regime

abstract:
  We presented a methodology to approximate the entropy production for Brownian
motion in a tilted periodic potential. The approximation stems from the well
known thermodynamic uncertainty relation. By applying a virial-like expansion,
we provided a tighter lower limit solely in terms of the drift velocity and
diffusion. The approach presented is systematically analysed in the
tight-binding regime. We also provide a relatively simple rule to validate
using the tight-binding approach based on drift and diffusion relations rather
than energy barriers and forces. We also discuss the implications of our
results outside the tight-binding regime.


title: Loop unrolling of UCA models: distance labeling

abstract:
  A proper circular-arc (PCA) model is a pair $M = (C, A)$ where $C$ is a
circle and $A$ is a family of inclusion-free arcs on $C$ whose extremes are
pairwise different. The model $M$ represents a digraph $D$ that has one vertex
$v(a)$ for each $a \in A$ and one edge $v(a) \to v(b)$ for each pair of arcs
$a,b \in A(M)$ such that the beginning point of $b$ belongs to $a$. For $k \geq
0$, the $k$-th power $D^k$ of $D$ has the same vertices as $D$ and $v(a) \to
v(b)$ is an edge of $D^k$ when $a\neq b$ and the distance from $v(a)$ to $v(b)$
in $D$ is at most $k$. A unit circular-arc (UCA) model is a PCA model $U =
(C,A)$ in which all the arcs have the same length $\ell+1$. If $\ell$, the
length $c$ of $C$, and the extremes of the arcs of $A$ are integer, then $U$ is
a $(c,\ell)$-CA model. For $i \geq 0$, the model $i \times U$ of $U$ is
obtained by replacing each arc $(s,s+\ell+1)$ with the arc $(s,s+i\ell+1)$. If
$U$ represents a digraph $D$, then $U$ is $k$-multiplicative when $i \times U$
represents $D^i$ for every $0 \leq i \leq k$. In this article we design a
linear time algorithm to decide if a PCA model $M$ is equivalent to a
$k$-multiplicative UCA model when $k$ is given as input. The algorithm either
outputs a $k$-multiplicative UCA model $U$ equivalent to $M$ or a negative
certificate that can be authenticated in linear time.
  Our main technical tool is a new characterization of those PCA models that
are equivalent to $k$-multiplicative UCA models. For $k=1$, this
characterization yields a new algorithm for the classical representation
problem that is simpler than the previously known algorithms.


title:
On the vanishing of Green's function, desingularization and Carleman's
  method

abstract:
  The subject of the present paper is the phenomenon of vanishing of the Green
function of the operator $-\Delta + V$ on $\mathbb R^3$ at the points where a
potential $V$ has positive critical singularities. More precisely, imposing
minimal assumptions on $V$ (i.e. the form-boundedness), we obtain an upper
bound on the order of vanishing of the Green function. As a by-product of our
proof, we improve the existing results on the strong unique continuation for
eigenfunctions of $-\Delta + V$ in dimension $d=3$.


title: NP-Hardness of a 2D, a 2.5D, and a 3D Puzzle Game

abstract:
  In this paper, we give simple NP-hardness reductions for three popular video
games. The first is Baba Is You, an award winning 2D block puzzle game with the
key premise being the ability to rewrite the rules of the game. The second is
Fez, a puzzle platformer whose main draw is the ability to swap between four
different 2-dimensional views of the player's position. The final is Catherine,
a 3-dimensional puzzle game where the player must climb a tower of
rearrangeable blocks.


title: A geometric study of circle packings and ideal class groups

abstract:
  A family of fractal arrangements of circles is introduced for each imaginary
quadratic field $K$. Collectively, these arrangements contain (up to an affine
transformation) every set of circles in the extended complex plane with
integral curvatures and Zariski dense symmetry group. When that set is a circle
packing, we show how the ambient structure of our arrangement gives a geometric
criterion for satisfying the almost local-global principle. Connections to the
class group of $K$ are also explored. Among them is a geometric property that
guarantees certain ideal classes are group generators.


title: Oscillating singular integral operators on compact Lie groups revisited

abstract:
  In [24, Theorem 2'] Charles Fefferman has proved the weak (1,1) boundedness
for a class of oscillating singular integrals that includes the oscillating
spectral multipliers of the Euclidean Laplacian $\Delta,$ namely, operators of
the form \begin{equation}
  T_{\theta}(-\Delta):= (1-\Delta)^{-\frac{n\theta}{4}}e^{i
(1-\Delta)^{\frac{\theta}{2}}},\,0\leq \theta <1. \end{equation} The aim of
this work is to extend Fefferman's result to oscillating singular integrals on
any arbitrary compact Lie group. Applications to oscillating spectral
multipliers of the Laplace-Beltrami operator are also considered. The proof of
our main theorem illustrates the delicate relationship between the condition on
the kernel of the operator, its Fourier transform (defined in terms of the
representation theory of the group) and the microlocal/geometric properties of
the group.


title:
Metamorphic dynamical quantum phase transition in double-quench
  processes at finite temperatures

abstract:
  By deriving a general framework and analyzing concrete examples, we
demonstrate a class of dynamical quantum phase transitions (DQPTs) in
one-dimensional two-band systems going through double-quench processes. When
this type of DQPT occurs, the Loschmidt amplitude vanishes and the rate
function remains singular after the second quench, meaning the final state
continually has no overlap with the initial state. This type of DQPT is named
metamorphic DQPT to differentiate it from ordinary DQPTs that only exhibit zero
Loschmidt amplitude and singular rate function at discrete time points. The
metamorphic DQPTs occur at zero as well as finite temperatures. Our examples of
the Su-Schrieffer-Heeger (SSH) model and Kitaev chain illustrate the conditions
and behavior of the metamorphic DQPT. Since ordinary DQPTs have been
experimentally realized in many systems, similar setups with double quenches
will demonstrate the metamorphic DQPT. Our findings thus provide additional
controls of dynamical evolution of quantum systems.


title:
Dynamic Sampling Rate: Harnessing Frame Coherence in Graphics
  Applications for Energy-Efficient GPUs

abstract:
  In real-time rendering, a 3D scene is modelled with meshes of triangles that
the GPU projects to the screen. They are discretized by sampling each triangle
at regular space intervals to generate fragments which are then added texture
and lighting effects by a shader program. Realistic scenes require detailed
geometric models, complex shaders, high-resolution displays and high screen
refreshing rates, which all come at a great compute time and energy cost. This
cost is often dominated by the fragment shader, which runs for each sampled
fragment. Conventional GPUs sample the triangles once per pixel, however, there
are many screen regions containing low variation that produce identical
fragments and could be sampled at lower than pixel-rate with no loss in
quality. Additionally, as temporal frame coherence makes consecutive frames
very similar, such variations are usually maintained from frame to frame. This
work proposes Dynamic Sampling Rate (DSR), a novel hardware mechanism to reduce
redundancy and improve the energy efficiency in graphics applications. DSR
analyzes the spatial frequencies of the scene once it has been rendered. Then,
it leverages the temporal coherence in consecutive frames to decide, for each
region of the screen, the lowest sampling rate to employ in the next frame that
maintains image quality. We evaluate the performance of a state-of-the-art
mobile GPU architecture extended with DSR for a wide variety of applications.
Experimental results show that DSR is able to remove most of the redundancy
inherent in the color computations at fragment granularity, which brings
average speedups of 1.68x and energy savings of 40%.


title:
Tracer particles sense local stresses in an evolving multicellular
  spheroid without affecting the anomalous dynamics of the cancer cells

abstract:
  Measurements of local stresses on the cancer cells (CCs), inferred by
embedding inert compressible tracer particles (TPs) in a growing multicellular
spheroid (MCS), show that pressure decreases monotonically as the distance from
the core of the MCS increases. How faithfully do the TPs report the local
stresses in the CCs is an important question because pressure buildup in the
MCS is dynamically generated due to CC division, which implies that the CC
dynamics should be minimally altered by the TPs. Here using theory and
simulations, we show that although the TP dynamics is unusual, exhibiting
sub-diffusive behavior on times less than the CC division times and
hyper-diffusive dynamics on in the long-time limit, they do not affect the
long-time CC dynamics or the local CC stress distributions. The CC pressure
profile within the MCS, which decays from a high value at the core to the
periphery, is almost identical with and without the TPs. That the TPs have
insignificant effect on the local stresses in the MCS implies that they are
reliable reporters of the CC microenvironment.

categories: cond-mat.soft cond-mat.stat-mech physics.bio-ph q-bio.CB


title: Role of rotations in Stern-Gerlach interferometry with massive objects

abstract:
  Realizing a spatial superposition with massive objects is one of the most
fundamental challenges, as it will test quantum theory in new regimes, probe
quantum-gravity, and enable to test exotic theories like gravitationally
induced collapse. A natural extension of the successful implementation of an
atomic Stern-Gerlach interferometer (SGI), is a SGI with a nano-diamond (ND) in
which a single spin is embedded in the form of a nitrogen-vacancy center (NV).
As the ND rotation, and with it the rotation of the NV spin direction, may
inhibit such a realization, both in terms of Newtonian trajectories and quantum
phases, we analyze here the role of rotations in the SGI. We take into account
fundamental limits, such as those imposed by the quantum angular uncertainty
relation and thermal fluctuations. We provide a detailed recipe for which a
superposition of massive objects is enabled. This may open the door not only to
fundamental tests, but also to new forms of quantum technology.


title:
Spanish and English Phoneme Recognition by Training on Simulated
  Classroom Audio Recordings of Collaborative Learning Environments

abstract:
  Audio recordings of collaborative learning environments contain a constant
presence of cross-talk and background noise. Dynamic speech recognition between
Spanish and English is required in these environments. To eliminate the
standard requirement of large-scale ground truth, the thesis develops a
simulated dataset by transforming audio transcriptions into phonemes and using
3D speaker geometry and data augmentation to generate an acoustic simulation of
Spanish and English speech. The thesis develops a low-complexity neural network
for recognizing Spanish and English phonemes (available at
github.com/muelitas/keywordRec). When trained on 41 English phonemes, 0.099 PER
is achieved on Speech Commands. When trained on 36 Spanish phonemes and tested
on real recordings of collaborative learning environments, a 0.7208 LER is
achieved. Slightly better than Google's Speech-to-text 0.7272 LER, which used
anywhere from 15 to 1,635 times more parameters and trained on 300 to 27,500
hours of real data as opposed to 13 hours of simulated audios.


title:
Nature vs. Nurture: Investigating the Effects of Measurement
  Uncertainties in the Assessment of Potential Trends Between Planetary and
  Stellar Properties

abstract:
  Correlations between planetary and stellar properties, particularly age, can
provide insight on planetary formation and evolution processes. However, the
underlying source of such trends can be unclear, and measurement uncertainties
and small sample sizes can leave doubt as to whether an observed trend truly
exists. We use a Bayesian framework to examine how uncertainties in measured
parameters influence the odds ratios of competing hypotheses for the source of
an observed trend. We analyze three reported trends from the literature. In
each application, while uncertainties do affect the numerical value of the odds
ratios, our conclusions remain the same whether or not uncertainties are taken
into account: hot Jupiter eccentricities are circularized over time,
obliquities of hot Jupiter hosts are driven by stellar temperature, and there
is not enough evidence to favor a trend of 2:1 orbital resonances with age over
a chance relation. Updated samples for the 2:1 resonances and obliquities cases
do not change the original conclusions. Simulated 2:1 resonance data show that
sample size may be more important than measurement precision for drawing a firm
conclusion. However, if 2:1 resonances get disrupted on a wide range of
timescales, an age trend will be inherently difficult to confirm over a chance
relation, even with a large sample. For some applications, full incorporation
of measurement uncertainties may be too computationally expensive, making it
preferable to use the framework without uncertainties and perform additional
tests to examine the effects of highly uncertain measurements.


title:
Sharpened Quasi-Newton Methods: Faster Superlinear Rate and Larger Local
  Convergence Neighborhood

abstract:
  Non-asymptotic analysis of quasi-Newton methods have gained traction
recently. In particular, several works have established a non-asymptotic
superlinear rate of $\mathcal{O}((1/\sqrt{t})^t)$ for the (classic) BFGS method
by exploiting the fact that its error of Newton direction approximation
approaches zero. Moreover, a greedy variant of BFGS was recently proposed which
accelerates its convergence by directly approximating the Hessian, instead of
the Newton direction, and achieves a fast local quadratic convergence rate.
Alas, the local quadratic convergence of Greedy-BFGS requires way more updates
compared to the number of iterations that BFGS requires for a local superlinear
rate. This is due to the fact that in Greedy-BFGS the Hessian is directly
approximated and the Newton direction approximation may not be as accurate as
the one for BFGS. In this paper, we close this gap and present a novel BFGS
method that has the best of both worlds in that it leverages the approximation
ideas of both BFGS and Greedy-BFGS to properly approximate the Newton direction
and the Hessian matrix simultaneously. Our theoretical results show that our
method out-performs both BFGS and Greedy-BFGS in terms of convergence rate,
while it reaches its quadratic convergence rate with fewer steps compared to
Greedy-BFGS. Numerical experiments on various datasets also confirm our
theoretical findings.


title:
Low-Metallicity Globular Clusters in the Low-Mass Isolated Spiral Galaxy
  NGC 2403

abstract:
  The globular cluster (GC) systems of low-mass late-type galaxies, such as NGC
2403, have been poorly studied to date. As a low mass galaxy (M$_{\ast}$ = 7
$\times$ 10$^{9}$ M$_{\odot}$), cosmological simulations predict NGC 2403 to
contain few, if any, accreted GCs. It is also isolated, with a remarkably
undisturbed HI disk. Based on candidates from the literature, Sloan Digital Sky
Survey and Hyper Suprime-Cam imaging, we selected several GCs for follow-up
spectroscopy using the Keck Cosmic Web Imager. From their radial velocities,
and other properties, we identify 8 bona-fide GCs associated with either the
inner halo or the disk of this bulgeless galaxy. A stellar population analysis
suggests a wide range of GC ages from shortly after the Big Bang until the
present day. We find all of the old GCs to be metal-poor with [Fe/H] $\le$ --1.
The age--metallicity relation for the observed GCs suggests that they were
formed over many Gyr from gas with a low effective yield, similar to that
observed in the SMC. Outflows of enriched material may have contributed to the
low yield. With a total system of $\sim$50 GCs expected, our study is the first
step in fully mapping the star cluster history of NGC 2403 in both space and
time.