  Automated hiring systems are among the fastest-developing of all high-stakes
AI systems. Among these are algorithmic personality tests that use insights
from psychometric testing, and promise to surface personality traits indicative
of future success based on job seekers' resumes or social media profiles. We
interrogate the validity of such systems using stability of the outputs they
produce, noting that reliability is a necessary, but not a sufficient,
condition for validity. Our approach is to (a) develop a methodology for an
external audit of stability of predictions made by algorithmic personality
tests, and (b) instantiate this methodology in an audit of two systems,
Humantic AI and Crystal. Crucially, rather than challenging or affirming the
assumptions made in psychometric testing -- that personality is a meaningful
and measurable construct, and that personality traits are indicative of future
success on the job -- we frame our methodology around testing the underlying
assumptions made by the vendors of the algorithmic personality tests
themselves.
  Our main contribution is the development of a socio-technical framework for
auditing the stability of algorithmic systems. This contribution is
supplemented with an open-source software library that implements the technical
components of the audit, and can be used to conduct similar stability audits of
algorithmic systems. We instantiate our framework with the audit of two
real-world personality prediction systems, namely Humantic AI and Crystal. The
application of our audit framework demonstrates that both these systems show
substantial instability with respect to key facets of measurement, and hence
cannot be considered valid testing instruments.


  Systematic engineering of atomic-scale low-dimensional defects in
two-dimensional nanomaterials is a promising way to modulate the electronic
properties of these nanomaterials. Defects at interfaces such as grain
boundaries and line defects can often be detrimental to technologically
important nanodevice operations and thus a fundamental understanding of how
such one-dimensional defects may have an influence on its physio-chemical
properties is pivotal to optimizing their device performance. Of late,
two-dimensional phosphorene has attracted much attention due to its high
carrier mobility and good mechanical flexibility. In this study, using
density-functional theory, we investigate the temperature-dependent energetics
and electronic structure of a single-layered phosphorene with various fault
line defects. We have generated different line defect models based on a fault
method, rather than the conventional rotation method. This has allowed us to
study and identify new low-energy line defects, and we show how these
low-energy line defects could well modulate the electronic band gap energies of
single-layered two-dimensional phosphorene -- offering a range of metallic to
semiconducting properties in these newly proposed low-energy line defects in
phosphorene.


  Counterfactual learning to rank (CLTR) has attracted extensive attention in
the IR community for its ability to leverage massive logged user interaction
data to train ranking models. While the CLTR models can be theoretically
unbiased when the user behavior assumption is correct and the propensity
estimation is accurate, their effectiveness is usually empirically evaluated
via simulation-based experiments due to a lack of widely-available,
large-scale, real click logs. However, the mainstream simulation-based
experiments are somewhat limited as they often feature a single, deterministic
production ranker and simplified user simulation models to generate the
synthetic click logs. As a result, the robustness of CLTR models in complex and
diverse situations is largely unknown and needs further investigation.
  To address this problem, in this paper, we aim to investigate the robustness
of existing CLTR models in a reproducibility study with extensive
simulation-based experiments that (1) use both deterministic and stochastic
production rankers, each with different ranking performance, and (2) leverage
multiple user simulation models with different user behavior assumptions. We
find that the DLA models and IPS-DCM show better robustness under various
simulation settings than IPS-PBM and PRS with offline propensity estimation.
Besides, the existing CLTR models often fail to outperform the naive click
baselines when the production ranker has relatively high ranking performance or
certain randomness, which suggests an urgent need for developing new CLTR
algorithms that work for these settings.


  Using numerical simulations, we perform an extensive finite-size analysis of
the transverse diffusion coefficient in a sheared 2D amorphous solid, over a
broad range of strain rates, at temperatures up to the supercooled liquid
regime. We thus obtain direct qualitative evidence for the persistence of
correlations between elementary plastic events up to the vicinity of the glass
transition temperature $T_g$. A quantitative analysis of the data, combined
with a previous study of the $T$- and $\dot\gamma$-dependence of the
macroscopic stress \cite{ChattorajCaroliLemaitre2010}, leads us to conclude
that the average avalanche size remains essentially unaffected by temperature
up to $T\sim0.75 T_g$.


  [Abridged] We consider two clusters (A496 and Coma) that are representative
of the two classes of cool-core and non-cool-core clusters. We first refer to a
two-component dynamical model that ignores the contribution from the galaxy
density distribution and study the condition of hydrostatic equilibrium for the
hot intracluster medium (ICM) under the assumption of spherical symmetry, in
the presence of dark matter. We model the ICM density distribution in terms of
a standard $\beta$-model with $\beta=2/3$, i.e. with a distribution similar to
that of a regular isothermal sphere (RIS), and fit the observed X-ray
brightness profiles. With the explicit purpose of ignoring cosmological
arguments, we na\"ively assume that dark matter, if present, has an analogous
density distribution, with the freedom of two different density and length
scales. The relative distribution of visible and dark matter is then derived by
fitting the temperature data for the ICM under conditions of hydrostatic
equilibrium. For both clusters, we find that dark matter is more concentrated
with respect to visible matter. We then test whether the conclusion changes
significantly when dark matter is taken to be distributed according to
cosmologically favored density profiles and when the contribution of the mass
contained in galaxies is taken into account. Although the qualitative
conclusions remain unchanged, we find that the contribution of galaxies to the
mass budget is more important than generally assumed. We also show that,
without resorting to additional information on the small scale, it is not
possible to tell whether a density cusp is present or absent in these systems.
[Abridged]


  We investigate the information which could be obtained from Drell-Yan
processes with sufficiently intense beams of charged kaons on isoscalar
targets. It is found that combinations of $K^+$ and $K^-$ Drell-Yan
measurements on isoscalar nuclear targets would allow one to extract the kaon
sea quark distributions. These cross sections are also sensitive to the strange
valence quark distribution in the kaon, although one would need a significant
increase over the presently available kaon fluxes in order to extract this
quantity with sufficient accuracy.


  Current top performing object detectors employ detection proposals to guide
the search for objects, thereby avoiding exhaustive sliding window search
across images. Despite the popularity and widespread use of detection
proposals, it is unclear which trade-offs are made when using them during
object detection. We provide an in-depth analysis of twelve proposal methods
along with four baselines regarding proposal repeatability, ground truth
annotation recall on PASCAL, ImageNet, and MS COCO, and their impact on DPM,
R-CNN, and Fast R-CNN detection performance. Our analysis shows that for object
detection improving proposal localisation accuracy is as important as improving
recall. We introduce a novel metric, the average recall (AR), which rewards
both high recall and good localisation and correlates surprisingly well with
detection performance. Our findings show common strengths and weaknesses of
existing methods, and provide insights and metrics for selecting and tuning
proposal methods.


  A search for pair-production of supersymmetric particles under the assumption
that R-parity is violated via a dominant LLE coupling has been performed using
the data collected by ALEPH at centre-of-mass energies of 130-172 GeV. The
observed candidate events in the data are in agreement with the Standard Model
expectation. This is translated into lower limits on the mass of charginos,
neutralinos, sleptons, sneutrinos and squarks. For instance, charginos with
masses less than 73 GeV and neutralinos with masses less than 23 GeV are
excluded at 95% confidence level for any generation structure of the LLE
coupling, and for neutralino, slepton or sneutrino LSPs.


  We give a simple and straightforward proof of the Gap Theorem for separated
sequences by A. Poltoratski and M. Mitkovski using the Beurling--Malliavin
formula for the radius of completeness.


  We present a model for the non-thermal emission from a colliding-wind binary.
Relativistic protons and electrons are assumed to be accelerated through
diffusive shock acceleration (DSA) at the global shocks bounding the wind-wind
collision region. The non-linear effects of the back-reaction due to the cosmic
ray pressure on the particle acceleration process and the cooling of the
non-thermal particles as they flow downstream from the shocks are included. We
explore how the non-thermal particle distribution and the keV-GeV emission
changes with the stellar separation and the viewing angle of the system, and
with the momentum ratio of the winds. We confirm earlier findings that DSA is
very efficient when magnetic field amplification is not included, leading to
significantly modified shocks. We also find that the non-thermal flux scales
with the binary separation in a complicated way and that the anisotropic
inverse Compton emission shows only a moderate variation with viewing angle due
to the spatial extent of the wind-wind collision.


  The search for sub-GeV dark matter via scattering on electrons has ramped up
in the last few years. Like in the case of dark matter scattering on nuclei,
electron-recoil-based searches also face an ultimate background in the form of
neutrinos. The so-called ``neutrino fog'' refers to the range of open
dark-matter parameter space where the background of neutrinos can potentially
prevent a conclusive discovery claim of a dark matter signal from being made.
In this study, we map the neutrino fog for a range of electron recoil
experiments based on silicon, germanium, xenon and argon targets. In analogy to
the nuclear recoil case, we also calculate the ''edge'' to the neutrino fog,
which can be used as a visual guide to where neutrinos become an important
background -- this boundary excludes some parts of the key theory milestones
used to motivate these experiments.


  Some accretion powered X-ray pulsars with supergiant companion stars undergo
occasional rapid spin-up episodes that last for weeks to a few months. We
explore the changes in the accretion environment of the pulsar GX 301-2 during
its latest 80 days long spin-up episode in 2019 when the spin frequency of the
pulsar increased by ~2% over two orbits of the binary. By performing
time-resolved spectroscopy with the MAXI/GSC spectra of the source, we
estimated the equivalent hydrogen column density and equivalent width of the
iron fluorescence line during the spin-up episode, and compared them with the
long-term average values estimated by orbital-phase resolved spectroscopy. The
measured absorption column density during the spin-up episode is about twice
that of an average orbit, while the equivalent width of the iron line is less
than half of an average orbit. Though the spin-up episode started immediately
after a pre-periastron flare and lasted for the two consecutive orbits of the
binary, the associated enhancement in luminosity started a few days after the
pre-periastron flare and lasted only during the first orbit, and some
enhancement was seen again during the pre-periastron passage of the second
orbit. The absorption column density and iron line equivalent width vary
throughout the spin-up episode and are distinct from an average orbit. These
observations indicate a significant change in the accretion and reprocessing
environment in GX 301-2 during the spin-up episode and may hold important clues
for the phenomenon in this source and several other sources with supergiant
companions.


  Fast magnetic fluctuations due to thermal torques have useful technological
functionality ranging from cryptography to probabilistic computing. The
characteristic time of fluctuations in typical uniaxial anisotropy magnets
studied so far is bounded from below by the well-known energy relaxation
mechanism. This time scales as $\alpha^{-1}$, where $\alpha$ parameterizes the
strength of dissipative processes. Here, we theoretically analyze the
fluctuating dynamics in easy-plane and antiferromagnetically coupled
nanomagnets. We find in such magnets, the dynamics are strongly influenced by
fluctuating intrinsic fields, which give rise to an additional dephasing-type
mechanism for washing out correlations. In particular, we establish two time
scales for characterizing fluctuations (i) the average time for a nanomagnet to
reverse|which for the experimentally relevant regime of low damping is governed
primarily by dephasing and becomes independent of $\alpha$, (ii) the time scale
for memory loss of a single nanomagnet|which scales as $\alpha^{-1/3}$ and is
governed by a combination of energy dissipation and dephasing mechanism. For
typical experimentally accessible values of intrinsic fields, the resultant
thermal-fluctuation rate is increased by multiple orders of magnitude when
compared with the bound set solely by the energy relaxation mechanism in
uniaxial magnets. This could lead to higher operating speeds of emerging
devices exploiting magnetic fluctuations.


  We give a simple and elementary proof of the identity
$$\sum_{r=1}^n\sum_{k_1,...,k_r\ge 1: \sum_{i=1}^r k_i= n} \frac {n!}
{k_1!k_2!...k_r!}k_1^{k_2}...k_{r-1}^{k_r}=(n+1)^{n-1}$$ where $n\in \mathbb
N$. A first application of this formula shows Cayley's theorem \cite{Caley} on
the number of trees with $n+1$ vertices (in fact the formula is equivalent to
Cayley's result). A second application gives the distribution of avalanche
sizes, which can be deduced for general dynamical systems and also as a
bilogically motivated urn model in probability. In particular, the law of
avalanche sizes in Eurich et al. \cite{EHE} and Levina \cite{Levina} is closely
related to this dynamical representation.


  The Wasserstein metric is an important measure of distance between
probability distributions, with applications in machine learning, statistics,
probability theory, and data analysis. This paper provides upper and lower
bounds on statistical minimax rates for the problem of estimating a probability
distribution under Wasserstein loss, using only metric properties, such as
covering and packing numbers, of the sample space, and weak moment assumptions
on the probability distributions.


  We observed the nearby and relatively understudied ultraluminous X-ray source
(ULX) NGC 4190 ULX-1 jointly with NICER and NuSTAR to investigate its broadband
spectrum, timing properties, and spectral variation over time. We found NGC
4190 ULX-1 to have a hard spectrum characterized by two thermal components
(with temperatures ~0.25keV and ~1.6keV) and a high-energy excess typical of
the ULX population, although the spectrum turns over at an unusually low
energy. While no pulsations were detected, (with pulsed fraction 3-sigma upper
limits of 16% for NICER and 35% for NuSTAR), the source shows significant
stochastic variability and the covariance spectrum indicates the presence of a
high-energy cut-off power-law component, potentially indicative of an accretion
column. Additionally, when fitting archival XMM-Newton data with a similar
model, we find that the luminosity-temperature evolution of the hot thermal
component follows the behavior of a super-Eddington slim disk though the
expected spectral broadening for such a disk is not seen, suggesting that the
inner accretion disk may be truncated by a magnetic field. Therefore, despite
the lack of detected pulsations, there is tantalizing evidence for NGC 4190
ULX-1 being a candidate neutron star accretor, although further broadband
observations will be required to confirm this behavior.


  (Abridged) We discuss the nature of the galaxies found in the Pico dos Dias
Survey (PDS) for young stellar objects. The PDS galaxies were selected from the
IRAS Point Source catalog. They have flux density of moderate or high quality
at 12, 25 and 60 $\mu$m and spectral indices in the ranges $-3.00 \leq
\alpha(25,12) \leq +0.35$ and $-2.50 \leq \alpha(60,25) \leq +0.85$. These
criteria allowed the detection of 382 galaxies, which are a mixture of
starburst and Seyfert galaxies.
  The starburst galaxies show an excess of FIR luminosity and their IRAS colors
are significantly different from those of Seyfert galaxies -- 99% of the
starburst galaxies in our sample have a spectral index $\alpha(60,25) < -1.9$.
As opposed to Seyfert galaxies, very few PDS starbursts are detected in X-rays.
  In the infrared, the starburst galaxies form a continuous sequence with
normal galaxies. But they generally can be distinguished from normal galaxies
by their spectral index $\alpha(60,25) > -2.5$. This color cut--off also marks
a change in the dominant morphologies of the galaxies: the normal IRAS galaxies
are preferentially late--type spirals (Sb and later), while the starbursts are
more numerous among early--type spirals (earlier than Sbc).
  No difference is found between the starbursts detected in the FIR and those
detected on the basis of UV excess. The PDS starburst galaxies represent the
FIR luminous branch of the UV-bright starburst nucleus galaxies, with mean FIR
luminosity $\log({\rm L}_{\rm IR}/{\rm L}_\odot) = 10.3 \pm 0.5$ and redshifts
smaller than 0.1. They form a complete sample limited in flux in the FIR at
$2\times10^{-10}$ erg cm$^{-2}$ s$^{-1}$.


  Navigation is an essential ability for mobile agents to be completely
autonomous and able to perform complex actions. However, the problem of
navigation for agents with limited (or no) perception of the world, or devoid
of a fully defined motion model, has received little attention from research in
AI and Robotics. One way to tackle this problem is to use guided navigation, in
which other autonomous agents, endowed with perception, can combine their
distinct viewpoints to infer the localisation and the appropriate commands to
guide a sensory deprived agent through a particular path. Due to the limited
knowledge about the physical and perceptual characteristics of the guided
agent, this task should be conducted on a level of abstraction allowing the use
of a generic motion model, and high-level commands, that can be applied by any
type of autonomous agents, including humans. The main task considered in this
work is, given a group of autonomous agents perceiving their common environment
with their independent, egocentric and local vision sensors, the development
and evaluation of algorithms capable of producing a set of high-level commands
(involving qualitative directions: e.g. move left, go straight ahead) capable
of guiding a sensory deprived robot to a goal location.


  Consider a linear regression model where the design matrix X has n rows and p
columns. We assume (a) p is much large than n, (b) the coefficient vector beta
is sparse in the sense that only a small fraction of its coordinates is
nonzero, and (c) the Gram matrix G = X'X is sparse in the sense that each row
has relatively few large coordinates (diagonals of G are normalized to 1).
  The sparsity in G naturally induces the sparsity of the so-called graph of
strong dependence (GOSD). We find an interesting interplay between the signal
sparsity and the graph sparsity, which ensures that in a broad context, the set
of true signals decompose into many different small-size components of GOSD,
where different components are disconnected.
  We propose Graphlet Screening (GS) as a new approach to variable selection,
which is a two-stage Screen and Clean method. The key methodological innovation
of GS is to use GOSD to guide both the screening and cleaning. Compared to
m-variate brute-forth screening that has a computational cost of p^m, the GS
only has a computational cost of p (up to some multi-log(p) factors) in
screening.
  We measure the performance of any variable selection procedure by the minimax
Hamming distance. We show that in a very broad class of situations, GS achieves
the optimal rate of convergence in terms of the Hamming distance. Somewhat
surprisingly, the well-known procedures subset selection and the lasso are rate
non-optimal, even in very simple settings and even when their tuning parameters
are ideally set.


  In this paper, weighted norm inequalities with $A_p$ weights are established
for the multilinear singular integral operators whose kernels satisfy
$L^{r'}$-H\"ormander regularity condition. As applications, we recover a
weighted estimate for the multilinear Fourier multiplier obtained by Fujita and
Tomita, and obtain several new weighted estimates for the multilinear Fourier
multiplier as well.


  We investigate the baryon mass spectrum in quenched lattice QCD with exact
chiral symmetry. For 100 gauge configurations generated with Wilson gauge
action at $ \beta = 6.1 $ on the $ 20^3 \times 40 $ lattice, we compute
(point-to-point) quark propagators for 30 quark masses in the range $ 67 {MeV}
\le m_q \le 1790 {MeV} $. For baryons only composed of strange and charm
quarks, their masses are extracted directly from the time correlation
functions, while for those containing $ u (d) $ light quarks, their masses are
obtained by chiral extrapolation to $ m_\pi = 135 $ MeV. Our results of baryon
masses are in good agreement with experimental values, except for the negative
parity states of $ \Lambda $ and $ \Lambda_c $. Further, our results of charmed
(including doubly-charmed and triply-charmed) baryons can serve as predictions
of QCD.


  We study the effect of adding disorder to the exactly solvable Kitaev model
on the hyper-honeycomb lattice, which hosts both gapped and gapless spin liquid
phases with an emergent $\mathbb{Z}_2$ gauge field. The latter has an unusual
gapless spectrum of Majorana fermion excitations, with a co-dimension-two Fermi
ring. We thus address the question of the interplay of topological physics and
disorder by considering the properties of isolated single and pair of
vacancies. We show that near the vacancies, the local magnetic response to a
field $h_z$ is parametrically enhanced in comparison to the pristine bulk.
Unlike the previously studied case of the 2D honeycomb Kitaev model, the
vacancies do not bind a flux of the $\mathbb{Z}_2$ gauge field. In the gapped
phase, an isolated vacancy gives rise to effectively free spin-half moments
with a non-universal coupling to an external field. In the gapless phase, the
low-field magnetization is suppressed parametrically, to $(-\ln h_z)^{-1/2}$
because of interactions with the surrounding spin-liquid. We also show that a
pair of vacancies is subject to a sublattice-dependent interaction on account
of coupling through the bulk spin liquid, which is spatially anisotropic even
when all Kitaev couplings have equal strength. This coupling is thus
exponentially suppressed with distance in the gapped phase. In the gapless
phase, two vacancies on the same (opposite) sublattice exhibit an enhanced
(suppressed) low-field response, amounting to an effectively
(anti-)ferromagnetic interaction.


  A growing number of previously hidden Galactic X-ray sources are now detected
with recent surveys performed by the Integral and Swift satellites. Most of
these new sources eluded past surveys due to their large local X-ray extinction
and consequent low soft X-ray flux. The Swift-BAT performs daily monitoring of
the sky in an energy band (15-150 keV) which is only marginally affected by
X-ray extinction, thus allowing for the search of long periodicities in the
light curve and identification of the nature of the X-ray sources. We performed
a period search using the folding technique in the Swift-BAT light curves of
three Integral sources: IGR J05007-7047, IGR J13186-6257 and IGR J17354-3255.
Their periodograms show significant peaks at 30.77$\pm$0.01 d, 19.994$\pm$0.01
d and 8.448$\pm$0.002 d, respectively. We estimate the significance of these
features from the chi squared distribution of all the trials, finding a
probability less than 1.5$\times10^{-4}$ that the detections occurred due to
chance. We complement our analysis with the study of their broadband X-ray
emission. We identify the periodicities with the orbital periods of the
sources. The periods are typical for the wind accretors X-ray binaries and we
support this identification showing that also their energy spectra are
compatible with an X-ray spectral emission characteristic of high-mass X-ray
binaries. The spectrum of IGR J05007-704 that resides in the Large Magellanic
Cloud, does not show any intrinsic local absorption, whereas the spectra of the
Galactic sources IGR J17354-3255 and IGR J13186-6257 may be affected by a local
absorber. The folded light curve for IGR J13186-6257 suggests a possible Be
companion star.


  We present a study of quasar selection using the DES supernova fields. We
used a quasar catalog from an overlapping portion of the SDSS Stripe 82 region
to quantify the completeness and efficiency of selection methods involving
color, probabilistic modeling, variability, and combinations of
color/probabilistic modeling with variability. We only considered objects that
appear as point sources in the DES images. We examine color selection methods
based on the WISE mid-IR W1-W2 color, a mixture of WISE and DES colors (g-i and
i-W1) and a mixture of VHS and DES colors (g-i and i-K). For probabilistic
quasar selection, we used XDQSOz, an algorithm that employs an empirical
multi-wavelength flux model of quasars to assign quasar probabilities. Our
variability selection uses the multi-band chi2-probability that sources are
constant in the DES Year 1 griz-band light curves. The completeness and
efficiency are calculated relative to an underlying sample of point sources
that are detected in the required selection bands and pass our data quality and
photometric error cuts. We conduct our analyses at two magnitude limits, i<19.8
mag and i<22 mag. For sources with W1 and W2 detections, the W1-W2 color or
XDQSOz method combined with variability gives the highest completenesses of
>85% for both i-band magnitude limits and efficiencies of >80% to the bright
limit and >60% to the faint limit; however, the giW1 and giW1+variability
methods give the highest quasar surface densities. The XDQSOz method and
combinations of W1W2/giW1/XDQSOz with variability are among the better
selection methods when both high completeness and high efficiency are desired.
We also present the OzDES Quasar Catalog of 1,263 spectroscopically-confirmed
quasars taken by the OzDES survey. The catalog includes quasars with redshifts
up to z~4 and brighter than i=22 mag, although the catalog is not complete up
this magnitude limit.


  Agents are represented by nodes on a random graph (e.g., small world or
truncated power law). Each agent is endowed with a zero-mean random value that
may be either positive or negative. All agents attempt to find relief, i.e., to
reduce the magnitude of that initial value, to zero if possible, through
exchanges. The exchange occurs only between agents that are linked, a
constraint that turns out to dominate the results. The exchange process
continues until a Pareto equilibrium is achieved. Only 40%-90% of the agents
achieved relief on small world graphs with mean degree between 2 and 40. Even
fewer agents achieved relief on scale-free like graphs with a truncated power
law degree distribution. The rate at which relief grew with increasing degree
was slow, only at most logarithmic for all of the graphs considered; viewed in
reverse, relief is resilient to the removal of links.


  For comprehensive studying of giant pulses (GPs) from the Crab pulsar and the
original millisecond pulsar (MSP) B1937+21 (J1939+2134), we conducted
multifrequency observations over the last few years. They show that giant
pulses may be improbably bright, 10^5, 10^6 Jy and more, they have extra
ordinal spectra and polarization. EM energy concentrated in such strong pulse
is high enough to accelerate particles up to Lorenz factor gamma ~ 10^4 - 10^6,
since giant pulses may play an important role in physics of pulsar's
magnetosphere.


  We have combined Hubble Space Telescope/Faint Object Spectrograph,
ground-based, and Infrared Space Observatory spectra of the nucleus of NGC
4395, the least luminous and nearest known type 1 Seyfert galaxy. The spectra
show emission lines from a wide range of ionization states and critical
densities. We have generated multicomponent photoionization models of both the
broad and narrow emission-line regions (BLR and NLR) to investigate the
physical conditions in the emission-line gas and test the proposition that the
source of ionization is the non-thermal continuum radiation emitted by the
central source. We show that, with a minimum of free parameters, the model
predictions match the observed emission-line ratios quite well. The elemental
abundances appear to be subsolar, with even greater underabundance of
nitrogen.From the size of the BLR predicted by the models, we estimate a
central mass of a few x 10^5 solar masses, in reasonable agreement with
estimates from the stellar kinematics. Finally, our results suggest that the
covering factor of the emission-line gas is close to unity, and that the
observed UV to X-ray continuum is absorbed by intervening NLR gas. We argue
that high covering factor is responsible for the apparent flattening of the
Baldwin relation in low luminosity AGN.


  In Part I of this paper we propose a decentralized optimal frequency control
of multi-area power system with operational constraints, where the tie-line
powers remain unchanged in the steady state and the power mismatch is balanced
within individual control areas. In Part II of the paper, we propose a
distributed controller for optimal frequency control in the network power
balance case, where the power mismatch is balanced over the whole system. With
the proposed controller, the tie-line powers remain within the acceptable range
at equilibrium, while the regulation capacity constraints are satisfied both at
equilibrium and during transient. It is revealed that the closed-loop system
with the proposed controller carries out primal-dual updates with saturation
for solving an associated optimization problem. To cope with discontinuous
dynamics of the closed-loop system, we deploy the invariance principle for
nonpathological Lyapunov function to prove its asymptotic stability. Simulation
results are provided to show the effectiveness of our controller.


  Heavy quarks provide a new dimension to QCD, allowing tests of fundamental
theory, the nature of color confinement, and the production of new exotic
multiquark states. I also discuss novel explanations for several apparently
anomalous experimental results, such as the large $t \bar t$ forward-backward
asymmetry observed in $p \bar p$ colisions at the Tevatron, the large rates for
$\gamma$ or $Z$ plus high-$p_T$ charm jets observed at the Tevatron, the strong
nuclear absorption of the $J/\psi$ observed in $pA$ collisions at the LHC, as
well as fixed target experiments at high $x_F$. Precision measurements of the
heavy quark distribution in hadrons at high $x$ are needed since intrinsic
heavy quarks can play an important role in high $x$ phenomenology as well as
predicting a new mechanism for high-$x_F$ Higgs production. The role of
multi-parton interactions, such as di-gluon initiated subprocesses for forward
quarkonium hadroproduction, is discussed. I also briefly discuss a new approach
to the QCD confinement potential and the origin of the QCD mass scale based on
AdS/QCD, light-front holography and a unique extension of conformal theory. The
renormalization scale ambiguity can be eliminated at finite orders in pQCD
using the scheme-independent PMC procedure, thus increasing the precision of
predictions and eliminating an unnecessary source of theoretical systematic
error.


  In this article, we propose a growing network model based on an optimal
policy involving both topological and geographical measures. In this model, at
each time step, a new node, having randomly assigned coordinates in a $1 \times
1$ square, is added and connected to a previously existing node $i$, which
minimizes the quantity $r_i^2/k_i^\alpha$, where $r_i$ is the geographical
distance, $k_i$ the degree, and $\alpha$ a free parameter. The degree
distribution obeys a power-law form when $\alpha=1$, and an exponential form
when $\alpha=0$. When $\alpha$ is in the interval $(0,1)$, the network exhibits
a stretched exponential distribution. We prove that the average topological
distance increases in a logarithmic scale of the network size, indicating the
existence of the small-world property. Furthermore, we obtain the geographical
edge-length distribution, the total geographical length of all edges, and the
average geographical distance of the whole network. Interestingly, we found
that the total edge-length will sharply increase when $\alpha$ exceeds the
critical value $\alpha_c=1$, and the average geographical distance has an upper
bound independent of the network size. All the results are obtained
analytically with some reasonable approximations, which are well verified by
simulations.


  We study a Michaelis-Menten reaction for a single two-state enzyme molecule,
whose transition rates between the two conformations are modulated by an
harmonically oscillating external force. In particular, we obtain a range of
optimal driving frequencies for changing the conformation of the enzyme thereby
controlling the enzymatic activity (i.e. product formation). This analysis
demonstrates that it is, in principle, possible to obtain information about
particular rates within the kinetic scheme.


  We consider a two component Bose-Einstein condensate in two spatially
localized modes of a double well potential, with periodic modulation of the
tunnel coupling between the two modes. We treat the driven quantum field using
a two mode expansion and define the quantum dynamics in terms of the Floquet
Operator for the time periodic Hamiltonian of the system. It has been shown
that the corresponding semiclassical mean-field dynamics can exhibit regions of
regular and chaotic motion. We show here that the quantum dynamics can exhibit
dynamical tunneling between regions of regular motion, centered on fixed points
(resonances) of the semiclassical dynamics.


  Based on 2-minute cadence TESS data from sectors 1-50, we report the results
of the systematic extraction of $\delta$ Scuti-type pulsations in the 6431
eclipsing binaries with orbital periods shorter than 13 days. A total number of
242 pulsators were found in those systems, including 143 new discoveries. We
examined their pulsation properties based on the H-R diagram and the
relationships between the dominant pulsation period $P_{\rm dom}$, orbital
period $P_{\rm orb}$, and effective temperature $T_{\rm eff}$. As a
consequence, 216 targets are likely $\delta$ Scuti stars (123 new), 11 likely
$\gamma$ Doradus-$\delta$ Scuti hybrid stars (8 new), 5 likely $\beta$ Cephei
stars (4 new), 4 likely $\delta$ Scuti-$\gamma$ Doradus hybrid stars (3 new), 3
likely Maia stars (3 new), 2 likely pulsating red giants (1 new), and a new
unclassified star. As for the 6 new $\delta$ Scuti pulsators in eclipsing
binaries with $P_{\rm orb}$ $<$ 0.65 days, we found that 3 of them
significantly exceed the upper limits of the $P_{\rm dom}$/$P_{\rm orb}$ ratio.
This may indicate that $P_{\rm dom}$ and $P_{\rm orb}$ are uncorrelated for
them. Finally, we statistically analyzed the dominant pulsation periods of the
216 $\delta$ Scuti stars in eclipsing binaries. Those stars concentrate around
225 $\mu$Hz and the proportion of stars in the high-frequency region is
significantly higher than that of single stars, which could be ascribed to the
mass transfer process.


  Built on top of self-attention mechanisms, vision transformers have
demonstrated remarkable performance on a variety of vision tasks recently.
While achieving excellent performance, they still require relatively intensive
computational cost that scales up drastically as the numbers of patches,
self-attention heads and transformer blocks increase. In this paper, we argue
that due to the large variations among images, their need for modeling
long-range dependencies between patches differ. To this end, we introduce
AdaViT, an adaptive computation framework that learns to derive usage policies
on which patches, self-attention heads and transformer blocks to use throughout
the backbone on a per-input basis, aiming to improve inference efficiency of
vision transformers with a minimal drop of accuracy for image recognition.
Optimized jointly with a transformer backbone in an end-to-end manner, a
light-weight decision network is attached to the backbone to produce decisions
on-the-fly. Extensive experiments on ImageNet demonstrate that our method
obtains more than 2x improvement on efficiency compared to state-of-the-art
vision transformers with only 0.8% drop of accuracy, achieving good
efficiency/accuracy trade-offs conditioned on different computational budgets.
We further conduct quantitative and qualitative analysis on learned usage
polices and provide more insights on the redundancy in vision transformers.


  How can a system in a macroscopically stable state explore energetically more
favorable states, which are far away from the current equilibrium state? Based
on continuum mechanical considerations we derive a Boussinesq-type equation
which models the dynamics of martensitic phase transformations. The solutions
of the system, which we refer to as microkinetically regularized wave equation
exhibit strong oscillations after short times, thermalization can be confirmed.
That means that macroscopic fluctuations of the solutions decay at the benefit
of microscopic fluctuations. First analytical and numerical results on the
propagation of phase boundaries and thermalization effects are presented.
Despite the fact that model is conservative, it exhibits the hysteretic
behavior. Such a behavior is usually interpreted in macroscopic models in terms
of dissipative threshold which the driving force has to overcome to ensure that
the phase transformation proceeds. The threshold value depends on the amount of
the transformed phase as it is observed in known experiments. Secondly we
investigate the dynamics of oscillatory solutions. We present a formalism based
on Young measures, which allows us to describe the effective dynamics of
rapidly fluctuating solutions. The new method enables us to derive a numerical
scheme for oscillatory solutions based on particle methods.


  Based on the NRQCD factorization formalism, we calculate the
next-to-next-to-leading order QCD corrections to the heavy quarkonium $\eta_c
(\eta_b)$ production associated with a photon at electron-positron colliders.
By matching the amplitudes calculated in full QCD theory to a series of
operators in NRQCD, the short-distance coefficients up to NNLO QCD radiative
corrections are determined. It turns out that the full set of master integrals
that we obtained could be analytically expressed in terms of Goncharov
Polylogarithms, Chen's iterated integrals, and elliptic functions, which mostly
do not exist in the literature and could be employed in the analyses of other
physical processes. In phenomenology, numerical calculations of NNLO K-factors
and cross sections of $e^+e^-\rightarrow \gamma + \eta_c(\eta_b)$ processes in
BESIII and B-factory experiments are performed, which may stand as a test of
the NRQCD higher order calculation while confronting to the data.


  Langevin dynamical simulations are performed to study the depinning dynamics
of two-dimensional dusty plasmas on a one-dimensional periodic substrate. From
the diagnostics of the sixfold coordinated particles $P_6$ and the collective
drift velocity $V_x$, three different states appear, which are the pinning,
disordered plastic flow, and moving ordered states. It is found that the depth
of the substrate is able to modulate the properties of the depinning phase
transition, based on the results of $P_6$ and $V_x$, as well as the observation
of hysteresis of $V_x$ while increasing and decreasing the driving force
monotonically. When the depth of the substrate is shallow, there are two
continuous phase transitions. When the potential well depth slightly increases,
the phase transition from the pinned to the disordered plastic flow states is
continuous; however, the phase transition from the disordered plastic flow to
the moving ordered states is discontinuous. When the substrate is even deeper,
the phase transition from the pinned to the disordered plastic flow states
changes to discontinuous. When the substrate further increases, as the driving
force increases, the pinned state changes to the moving ordered state directly,
so that the disordered plastic flow state disappears completely.


  Let $D$ be a bounded strongly convex domain in the complex space of dimension
$n$. Fixed a point $p\in \partial D$, we consider the solution of a homogeneous
complex Monge-Ampere equation with simple pole at $p$. We prove that such a
solution enjoys many properties of the classical Poisson kernel in the unit
disc and thus deserves to be called the pluricomplex Poisson kernel of $D$ with
pole at $p$. In particular we discuss extremality properties (such as a
generalization of the classical Phragmen-Lindelof theorem), relations with the
pluricomplex Green function of $D$, uniqueness in terms of the associated
foliation and boundary behaviors and reproducing formulas for plurisubharmonic
functions.


  For a group $G,$ let $\Gamma(G)$ denote the graph defined on the elements of
$G$ in such a way that two distinct vertices are connected by an edge if and
only if they generate $G$. Moreover let $\Gamma^*(G)$ be the subgraph of
$\Gamma(G)$ that is induced by all the vertices of $\Gamma(G)$ that are not
isolated. We prove that if $G$ is a 2-generated non-cyclic abelian group then
$\Gamma^*(G)$ is connected. Moreover $\mathrm{diam}(\Gamma^*(G))=2$ if the
torsion subgroup of $G$ is non-trivial and $\mathrm{diam}(\Gamma^*(G))=\infty$
otherwise. If $F$ is the free group of rank 2, then $\Gamma^*(F)$ is connected
and we deduce from $\mathrm{diam}(\Gamma^*(\mathbb{Z}\times
\mathbb{Z}))=\infty$ that $\mathrm{diam}(\Gamma^*(F))=\infty.$


  Optically active solid-state spin registers have demonstrated their unique
potential in quantum computing, communication and sensing. Realizing
scalability and increasing application complexity requires entangling multiple
individual systems, e.g. via photon interference in an optical network.
However, most solid-state emitters show relatively broad spectral
distributions, which hinders optical interference experiments. Here, we
demonstrate that silicon vacancy centres in semiconductor silicon carbide (SiC)
provide a remarkably small natural distribution of their optical
absorption/emission lines despite an elevated defect concentration of $\approx
0.43\,\rm \mu m^{-3}$. In particular, without any external tuning mechanism, we
show that only 13 defects have to be investigated until at least two optical
lines overlap within the lifetime-limited linewidth. Moreover, we identify
emitters with overlapping emission profiles within diffraction limited
excitation spots, for which we introduce simplified schemes for generation of
computationally-relevant Greenberger-Horne-Zeilinger (GHZ) and cluster states.
Our results underline the potential of the CMOS-compatible SiC platform toward
realizing networked quantum technology applications.


  Configuration space Faddeev equations are applied to describe the Be9Lambda
low-lying resonances of the ground band in the alpha+alpha+Lambda cluster
model. The method of analytical continuation in coupling constant is used.


  A re-analysis of the Stokes-parameter spectra obtained of the z=0.692 21 cm
absorption line toward 3C 286 shows that our original claimed detection of
Zeeman splitting by a line-of-sight magnetic field, B_los = 87 microgauss is
incorrect. Because of an insidious software error, what we reported as Stokes V
is actually Stokes U: the revised Stokes V spectrum indicates a 3-sigma upper
limit of B_los < 17 microgauss. The correct analysis reveals an absorption
feature in fractional polarization that is offset in velocity from the Stokes I
spectrum by -1.9 km/s. The polarization position-angle spectrum shows a dip
that is also significantly offset from the Stokes I feature, but at a velocity
that differs slightly from the absorption feature in fractional polarization.
We model the absorption feature with 3 velocity components against the core-jet
structure of 3C 286. Our chisquare minimization fitting results in components
with differing (1) ratios of H I column density to spin temperature, (2)
velocity centroids, and (3) velocity dispersions. The change in polarization
position angle with frequency implies incomplete coverage of the background jet
source by the absorber. It also implies a spatial variation of the polarization
position angle across the jet source, which is observed at frequencies higher
than the 839.4 MHz absorption frequency. The multi-component structure of the
gas is best understood in terms of components with spatial scales of ~100 pc
comprised of hundreds of low-temperature (T < 200 K) clouds with linear
dimensions of about 1 pc.


  Let $\{X_{\mathbf{n}} : \mathbf{n}\in\mathbb{Z}^d\}$ be a weakly dependent
stationary field with maxima $M_{A} := \sup\{X_{\mathbf{i}} : \mathbf{i}\in
A\}$ for finite $A\subset\mathbb{Z}^d$ and $M_{\mathbf{n}} :=
\sup\{X_{\mathbf{i}} : \mathbf{1} \leq \mathbf{i} \leq \mathbf{n} \}$ for
$\mathbf{n}\in\mathbb{N}^d$. In a general setting we prove that
$P(M_{(n,n,\ldots, n)} \leq v_n) = \exp(- n^d P(X_{\mathbf{0}} > v_n , M_{A_n}
\leq v_n)) + o(1)$, for some increasing sequence of sets $A_n$ of size $
o(n^d)$. For a class of fields satisfying a local mixing condition, including
$m$-dependent ones, the theorem holds with a constant finite $A$ replacing
$A_n$. The above results lead to new formulas for the extremal index for random
fields.


  In-context Learning (ICL) empowers large language models (LLMs) to adapt to
unseen tasks during inference by prefixing a few demonstration examples prior
to test queries. Despite its versatility, ICL incurs substantial computational
and memory overheads compared to zero-shot learning and is susceptible to the
selection and order of demonstration examples. In this work, we introduce
Implicit In-context Learning (I2CL), an innovative paradigm that addresses the
challenges associated with traditional ICL by absorbing demonstration examples
within the activation space. I2CL first generates a condensed vector
representation, namely a context vector, from the demonstration examples. It
then integrates the context vector during inference by injecting a linear
combination of the context vector and query activations into the model's
residual streams. Empirical evaluation on nine real-world tasks across three
model architectures demonstrates that I2CL achieves few-shot performance with
zero-shot cost and exhibits robustness against the variation of demonstration
examples. Furthermore, I2CL facilitates a novel representation of "task-ids",
enhancing task similarity detection and enabling effective transfer learning.
We provide a comprehensive analysis of I2CL, offering deeper insights into its
mechanisms and broader implications for ICL. The source code is available at:
https://github.com/LzVv123456/I2CL.


  Consider a transitive expanding dynamical system $ \sigma: \Sigma \to \Sigma
$, and a H\"older potential $ A $. In ergodic optimization, one is interested
in properties of $A$-maximizing probabilities. Assuming ergodicity, it is
already known that the projection of the support of such probabilities is
contained in the set of non-wandering points with respect to $ A $, denoted by
$ \Omega(A) $. A separating sub-action is a sub-action such that the
sub-cohomological equation becomes an identity just on $ \Omega(A) $. For a
fixed H\"older potential $ A $, we prove not only that there exists H\"older
separating sub-actions but in fact that they define a residual subset of the
H\"older sub-actions.
  We use the existence of such separating sub-actions in an application for the
case one has more than one maximizing probability. Suppose we have a finite
number of distinct $A$-maximizing probabilities with ergodic property: $ \hat
\mu_j $, $ j \in \{1, 2, ..., l\} $. Considering a calibrated sub-action $ u $,
under certain conditions, we will show that it can be written in the form $$ u
(\mathbf x)= u (\mathbf x^i) + h_A(\mathbf x^i, \mathbf x), $$ for all $
\mathbf x \in \Sigma $, where $ \mathbf x^i $ is a special point (in the
projection of the support of a certain $ \hat \mu_i $) and $ h_A $ is the
Peierls barrier associated to $ A $.


  If a core of dielectric material is coated by a plasmonic structure of
negative dielectric material with non-zero loss parameter, then anomalous
localized resonance may occur as the loss parameter tends to zero and the
source outside the structure can be cloaked. It has been proved that the
cloaking due to anomalous localized resonance (CALR) takes place for structures
of concentric disks and the critical radius inside which the sources are
cloaked has been computed. In this paper, it is proved that CALR takes place
for structures of confocal ellipses and the critical elliptic radii are
computed. The method of this paper uses the spectral analysis of the
Neumann-Poincar\'e type operator associated with two interfaces (the boundaries
of the core and the shell).


  With the rapid development of drone technology, the application of
multi-drones is becoming increasingly widespread in various fields. However,
the task planning technology for multi-drones still faces challenges such as
the complexity of remote operation and the convenience of human-machine
interaction. To address these issues, this paper proposes a prompt-driven task
planning method for multi-drones based on large language models. By introducing
the Prompt technique, appropriate prompt information is provided for the
multi-drone system.


  Automata operating on general graphs have been introduced by virtue of
graphoids. In this paper we construct a graph automaton that recognizes
$k$-colorable graphs.


  These are expanded notes on a lecture of the same title at the 2015 AMS
summer institute in algebraic geometry. We give an introduction and overview of
the "beyond geometric invariant theory" program for analyzing moduli problems
in algebraic geometry. We discuss methods for analyzing stability in general
moduli problems, focusing on the moduli of coherent sheaves on a smooth
projective scheme as a toy example. We describe several applications: a general
structure theorem for the derived category of coherent sheaves on an algebraic
stack; some results on the topology of moduli stacks; and a "virtual
non-abelian localization formula" in K-theory. We also propose a generalization
of toric geometry to arbitrary compactifications of homogeneous spaces for
algebraic groups, and formulate a conjecture on the Hodge theory of
algebraic-symplectic stacks.


  Metric-affine geometry provides a non-trivial extension of the general
relativity where the metric and connection are treated as the two independent
fundamental quantities in constructing the space-time (with non-vanishing
torsion and non-metricity). In this paper we study the generic form of action
in this formalism, and then construct the Weyl-invariant version of this
theory. It is shown that in Weitzenbock space, the obtained Weyl-invariant
action can cover the conformally invariant teleparallel action. Finally the
related field equations are obtained in the general case.


  We consider the $S^2 \times_q S^1$ supersymmetric index of a 3d
$\mathcal{N}=2$ theory $T[M_3]$ when $M_3$ is a plumbed 3-manifold. We engineer
an effective description of $T[M_3]$ from the expression of the homological
block for plumbed 3-manifolds as a $D^2 \times_q S^1$ partition function of a
3d $\mathcal{N}=2$ theory $T[M_3]$ with a boundary condition. We check that the
supersymmetric index for such a $T[M_3]$ is invariant under the 3d Kirby moves.


  Bulk La_wCoO3 particles with w=1.1, 1.0, 0.9, 0.8, and 0.7 were synthesized
using starting materials with varying molar ratios of La2O3 and Co3O4. The
resulting particles are characterized as LaCoO3 crystals interfaced with a
crystalline Co3O4 phase. X-ray and neutron scattering data show little effect
on the average structure and lattice parameters of the LaCoO3 phase resulting
from the Co3O4 content, but magnetization data indicate that the amount of
Co3O4 strongly affects the ferromagnetic ordering at the interfaces below T_C
~89K. In addition to ferromagnetic long-range order, LaCoO3 exhibits
antiferromagnetic behavior with an unusual temperature dependence. The
magnetization for fields 20 Oe < H < 5 kOe is fit to a combination of a power
law ((T-T_C)/T_C)^beta behavior representing the ferromagnetic long-range order
and sigmoid-convoluted Curie-Weiss-like behavior representing the
antiferromagnetic behavior. The critical exponent beta=0.63 +- 0.02 is
consistent with 2D (surface) ordering. Increased Co3O4 correlates well to
increased ferromagnetism. The weakening of the antiferromagnetism below T ~ 40K
is a consequence of the lattice reaching a critical rhombahedral distortion as
T is decreased for core regions far from the Co3O4 interfaces. We introduce a
model that describes the ferromagnetic behavior of the interface regions and
the unusual antiferromagnetism of the core regions.


  Allowing for the possibility of large extra dimensions, the fundamental
Planck scale $M$ could be anywhere in the range $\TeV\lsim M\lsim \mpl$, where
$\mpl=2.4\times 10^{18}\GeV$ is the four-dimensional Planck scale. If
$M\sim\TeV$, quantum corrections would not destabilize the Higgs mass even if
there were no supersymmetry. But we point out that supersymmetry must in fact
be present, if there is an era of cosmological inflation, since during such an
era the inflaton mass satisfies $m\ll M^2/\mpl=10^{-15}(M/\TeV)$ and
supersymmetry will be needed to protect it. If the inflation hypothesis is
accepted, there is no reason to think that Nature has chosen the low value
$M\sim \TeV$, however convenient that choice might have been for the next
generation of collider experiments.


  This paper develops the novel convergence analysis of a generic class of
descent methods in nonsmooth and nonconvex optimization under several versions
of the Kurdyka-\L ojasiewicz (KL) property. Along other results, we prove the
finite termination of generic algorithms under the KL property with lower
exponents. Specifications are given to convergence rates of some particular
algorithms including inexact reduced gradient methods and the boosted algorithm
in DC programming. It revealed, e.g., that the lower exponent KL property in
the DC framework is incompatible with the gradient Lipschitz continuity for the
plus function around a local minimizer. On the other hand, we show that the
above inconsistency observation may fail if the Lipschitz continuity is
replaced by merely the gradient continuity.


  Stochastic allocation of resources in the context of wireless systems
ultimately demands reactive decision making for meaningfully optimizing
network-wide random utilities, while respecting certain resource constraints.
Standard ergodic-optimal policies are however susceptible to the statistical
variability of fading, often leading to systems which are severely unreliable
and spectrally wasteful. On the flip side, minimax/outage-optimal policies are
too pessimistic and often hard to determine. We propose a new risk-aware
formulation of the resource allocation problem for standard multi-user
point-to-point power-constrained communication with no cross-interference, by
employing the Conditional Value-at-Risk (CV@R) as a measure of fading risk. A
remarkable feature of this approach is that it is a convex generalization of
the ergodic setting while inducing robustness and reliability in a fully
tunable way, thus bridging the gap between the (naive) ergodic and
(conservative) minimax approaches. We provide a closed-form expression for the
CV@R-optimal policy given primal/dual variables, extending the classical
stochastic waterfilling policy. We then develop a primal-dual tail-waterfilling
scheme to recursively learn a globally optimal risk-aware policy. The
effectiveness of the approach is verified via detailed simulations.


  A method is presented for the calculation of the one-body and two-body
density matrices and their Fourier transforms in momentum space, that is
consistent with the requirement for translational invariance, in the case of a
nucleus (a finite self-bound system). We restore translational invariance by
using the so-called fixed center-of-mass approximation for constructing an
intrinsic nuclear ground state wavefunction by starting from a
non-translationally invariant wavefunction and applying a projection
prescription. We discuss results for the one-body and two-body momentum
distributions of the 4He nucleus calculated with the Slater determinant of the
harmonic oscillator orbitals, as the initial non-translationally invariant
wavefunction. Effects of such an inclusion of CM correlations are found to be
quite important in the momentum distributions.


  We use N-body simulations to study the evolution of the orbital
eccentricities of stars deposited near (<0.05 pc) the Milky Way massive black
hole (MBH), starting from initial conditions motivated by two competing models
for their origin: formation in a disk followed by inward migration; and
exchange interactions involving a binary star. The first model predicts modest
eccentricities, lower than those observed in the S-star cluster, while the
second model predicts higher eccentricities than observed. The N-body
simulations include a dense cluster of 10 M_sun stellar black holes (SBHs),
expected to accumulate near the MBH by mass segregation. Perturbations from the
SBHs tend to randomize the stellar orbits, partially erasing the dynamical
signatures of their origin. The eccentricities of the initially highly
eccentric stars evolve, in 20 Myr (the S-star lifespan), to a distribution that
is consistent at the ~95 % level with the observed eccentricity distribution.
In contrast, the eccentricities of the initially more circular orbits fail to
evolve to the observed values in 20 Myr, arguing against the disk migration
scenario. We find that 20 % - 30 % of the S-stars are tidally disrupted by the
MBH over their lifetimes, and that the S-stars are not likely to be ejected as
hypervelocity stars outside the central 0.05 pc by close encounters with
stellar black holes.


  Recently, the black hole X-ray binary (BHXB) Nova Muscae 1991 has been
reported to be experiencing an extremely rapid orbital decay. So far, three
BHXBs have anomalously high orbital period derivatives, which can not be
interpreted by the standard stellar evolution theory. In this work, we
investigate whether the resonant interaction between the binary and a
surrounding circumbinary (CB) disk could produce the observed orbital period
derivatives. Analytical calculations indicate that the observed orbital period
derivatives of XTE J1118+480 and A0620-00 can originate from the tidal torque
between the binary and a CB disk with a mass of $10^{-9}~\rm M_{\odot}$, which
is approximately in agreement with the dust disk mass detected in these two
sources. However, Nova Muscae 1991 was probably surrounded by a heavy CB disk
with a mass of $10^{-7}~\rm M_{\odot}$. Based on the CB disk model and the
anomalous magnetic braking theory, we simulate the evolution of the three BHXBs
with intermediate-mass donor stars by using the MESA code. Our simulated
results are approximately consistent with the observed donor star masses,
orbital periods, and orbital-period derivatives. However, the calculated
effective temperatures of the donor stars are higher than indicated by the
observed spectral types of two sources.


  We present two constructions for binary self-orthogonal codes. It turns out
that our constructions yield a constructive bound on binary self-orthogonal
codes. In particular, when the information rate R=1/2, by our constructive
lower bound, the relative minimum distance \delta\approx 0.0595 (for GV bound,
\delta\approx 0.110). Moreover, we have proved that the binary self-orthogonal
codes asymptotically achieve the Gilbert-Varshamov bound.


  We prove stability of solutions of the complex Monge-Amp\`ere equation on
compact Hermitian manifolds, when the right hand side varies in a bounded set
in $L^p, p>1$ and it is bounded away from zero. Such solutions are shown to be
H\"older continuous. As an application we extend a recent result of
Sz\'ekelyhidi and Tosatti on K\"ahler-Einstein equation from K\"ahler to
Hermitian manifolds.


  Global isothermic immersions are defined and studied with the aid of a
connection between quadratic differentials and immersions. The applications are
two problems stemming from the fundamental question: how much data is needed to
identify a surface immersion (Christoffel's problem) or its shape (Bonnet's
problem). A short complete solution of Christoffel's problem, including closed
surfaces, is given. It is shown that every immersion of an oriented closed
surface (genus $\neq$ 1) is uniquely determined up to similitude by its
conformal class and the tangent planes map. A classification of all generic
Bonnet surfaces follows from a series of papers by Bonnet, Cartan, and Chern.
The existence of a new class of Bonnet surfaces is shown here. The
understanding of this class is necessary in order to study the rigidity of
closed surfaces.


  The consistent recursive subtraction of UV divergences order by order in the
loop expansion for spontaneously broken effective field theories with
dimension-6 derivative operators is presented for an Abelian gauge group. We
solve the Slavnov-Taylor identity to all orders in the loop expansion by
homotopy techniques and a suitable choice of invariant field coordinates (named
bleached variables) for the linearly realized gauge group. This allows one to
disentangle the gauge-invariant contributions to off-shell 1-PI amplitudes from
those associated with the gauge-fixing and (generalized) non-polynomial field
redefinitions (that do appear already at one loop). The tools presented can be
easily generalized to the non-Abelian case.


  We prove that every perfect torsion theory for a ring $R$ is differential (in
the sense of [P. E. Bland, Differential torsion theory, Journal of Pure and
Applied Algebra 204 (2006) 1 -- 8]). In this case, we construct the extension
of a derivation of a right $R$-module $M$ to a derivation of the module of
quotients of $M$. Then, we prove that the Lambek and Goldie torsion theories
for any $R$ are differential.


  We study solitons in a zig-zag lattice of magnetic dipoles. The lattice
comprises two sublattices of parallel chains with magnetic dipoles at their
vertices. Due to orthogonal easy planes of rotation for dipoles belonging to
different sublattices, the total dipolar energy of this system is separable
into a sum of symmetric and chiral long-ranged interactions between the magnets
where the last takes the form of Dzyaloshinskii-Moriya coupling. For a specific
range of values of the offset between sublattices, the dipoles realize an
equilibrium magnetic state in the lattice plane, consisting of one chain
settled in an antiferromagnetic parallel configuration and the other in a
collinear ferromagnetic fashion. If the offset grows beyond this value, the
internal Dzyaloshinskii-Moriya field stabilizes two Bloch domain walls at the
edges of the antiferromagnetic chain. The dynamics of these solitons is studied
by deriving the long-wavelength lagrangian density for the easy axis
antiferromagnet. We find that the chiral couplings between sublattices give
rise to an effective magnetic field that stabilizes the solitons in the
antiferromagnet. When the chains displace respect to each other, an emergent
Lorentz force accelerates the domain walls along the lattice.


  X-ray emission from the eastern radio lobe of the FRII Radio Galaxy Pictor A
was serendipitously discovered by a short observation of XMM-Newton in 2001.
The X-ray spectrum, accumulated on a region covering about half of the entire
radio lobe, was well described by both a thermal model and a power law, making
non-univocal the physical interpretation. A new XMM-Newton observation
performed in 2005 has allowed the detection of the X-ray emission from both
radio lobes and unambiguously revealed its non-thermal origin. The X-ray
emission is due to Inverse Compton (IC) of the cosmic microwave background
photons by relativistic electrons in the lobe. We confirm the discrepancy
between the magnetic field, as deduced from the comparison of the IC X-ray and
radio fluxes, and the equipartition value.


  We introduce shower deconstruction, a method to look for new physics in a
hadronic environment. The method aims to be a full information approach using
small jets. It assigns to each event a number chi that is an estimate of the
ratio of the probability for a signal process to produce that event to the
probability for a background process to produce that event. The analytic
functions we derive to calculate these probabilities mimic what full event
generators like Pythia or Herwig do and can be depicted in a diagrammatic way.
As an example, we apply this method to a boosted Higgs boson produced in
association with a Z-boson and show that this method can be useful to
discriminate this signal from the Z+jets background.


  Understanding the process of molecular photoexcitation is crucial in various
fields, including drug development, materials science, photovoltaics, and more.
The electronic vertical excitation energy is a critical property, for example
in determining the singlet-triplet gap of chromophores. However, a full
understanding of excited-state processes requires additional explorations of
the excited-state potential energy surface and electronic properties, which is
greatly aided by the availability of analytic energy gradients. Owing to its
robust high accuracy over a wide range of chemical problems, equation-of-motion
coupled-cluster with single and double excitations (EOM-CCSD) is a powerful
method for predicting excited state properties, and the implementation of
analytic gradients of many EOM-CCSD (excitation energies, ionization
potentials, electron attachment energies, etc.) along with numerous successful
applications highlights the flexibility of the method. In specific cases where
a higher level of accuracy is needed or in more complex electronic structures,
the inclusion of triple excitations becomes essential, for example, in the
EOM-CCSD* approach of Saeh and Stanton. In this work, we derive and implement
for the first time the analytic gradients of EOMEE-CCSD*, which also provides a
template for analytic gradients of related excited state methods with
perturbative triple excitations. The capabilities of analytic EOMEE-CCSD*
gradients are illustrated by several representative examples.


  We propose a density-dependent function for the attractive interaction in the
original van der Waals model to correctly describe the flow constraint at the
high-density regime of the symmetric nuclear matter. After a generalization to
asymmetric nuclear matter, it was also possible to study the stellar matter
regime from this new model. The mass-radius relation for neutron stars under
$\beta$-equilibrium is found to agree with recent X-ray observations. The
neutron star masses supported against gravity, obtained from some
parametrizations of the model, are in the range of $(1.97-2.07)M_{\odot}$,
compatible with observational data from the PSR J0348+0432 pulsar. Furthermore,
we verify the reliability of the model in predicting tidal deformabilities of
the binary system related to the GW170817 neutron star merger event and find a
full agreement with the new bounds obtained by the LIGO/Virgo collaboration.


  We discuss a decomposition formula of simple products of fermion correlation
functions with cyclic constrains and its applications to spin sums of super
string amplitudes. Based on some facts which are noted or derived in this
paper, we propose a candidate of the form of this decomposition formula for
some of higher genus cases which includes genus two case. Although we had to
use several conjectures and assumptions due to unsolved mathematical
difficulties, the method described in the text may be an efficient way to
obtain the decomposition formula in higher genus cases. In particular, for
those cases, we propose a concrete method to sum over non singular even spin
structures for the product of arbitrary number of the fermion correlation
functions with cyclic constraints in super string amplitudes. We also propose
an explicit generalization of Eisenstein-Kronecker series to the higher genus
cases in the process of considerations above.


  We characterize models of Peano arithmetic (PA) with infinitely many infinite
primes p such that p + 2 has no finite prime divisor.


  One approach to delay the spread of the novel coronavirus (COVID-19) is to
reduce human travel by imposing travel restriction policies. It is yet unclear
how effective those policies are on suppressing the mobility trend due to the
lack of ground truth and large-scale dataset describing human mobility during
the pandemic. This study uses real-world location-based service data collected
from anonymized mobile devices to uncover mobility changes during COVID-19 and
under the 'Stay-at-home' state orders in the U.S. The study measures human
mobility with two important metrics: daily average number of trips per person
and daily average person-miles traveled. The data-driven analysis and modeling
attribute less than 5% of the reduction in the number of trips and person-miles
traveled to the effect of the policy. The models developed in the study exhibit
high prediction accuracy and can be applied to inform epidemics modeling with
empirically verified mobility trends and to support time-sensitive
decision-making processes.


  A particle system with a single locally-conserved field (density) in a
bounded interval with different densities maintained at the two endpoints of
the interval is under study here. The particles interact in the bulk through a
long range potential parametrized by $\beta\ge 0$ and evolve according to an
exclusion rule. It is shown that the empirical particle density under the
diffusive scaling solves a quasi-linear integro-differential evolution equation
with Dirichlet boundary conditions. The associated dynamical large deviation
principle is proved. Furthermore, for $\beta$ small enough, it is also
demonstrated that the empirical particle density obeys a law of large numbers
with respect to the stationary measures (hydrostatic). The macroscopic particle
density solves a non local, stationary, transport equation.


  In the field of connectomics, neuroscientists seek to identify cortical
connectivity comprehensively. Neuronal boundary detection from the Electron
Microscopy (EM) images is often done to assist the automatic reconstruction of
neuronal circuit. But the segmentation of EM images is a challenging problem,
as it requires the detector to be able to detect both filament-like thin and
blob-like thick membrane, while suppressing the ambiguous intracellular
structure. In this paper, we propose multi-stage multi-recursive-input fully
convolutional networks to address this problem. The multiple recursive inputs
for one stage, i.e., the multiple side outputs with different receptive field
sizes learned from the lower stage, provide multi-scale contextual boundary
information for the consecutive learning. This design is
biologically-plausible, as it likes a human visual system to compare different
possible segmentation solutions to address the ambiguous boundary issue. Our
multi-stage networks are trained end-to-end. It achieves promising results on
two public available EM segmentation datasets, the mouse piriform cortex
dataset and the ISBI 2012 EM dataset.


  We construct triangular hyperbolic polyhedra whose links are generalized
4-gons. The universal cover of those polyhedra are hyperbolic buildings, which
appartments are hyperbolic planes tesselated by regular triangles with angles
$\pi/4$. Moreover, the fundamental groups of the polyhedra acts simply
transitively on vertices of the buildings.


  A weakly-interacting massive particle (WIMP) is perhaps the most promising
candidate for the dark matter in the Galactic halo. The WIMP detection rate in
laboratory searches is fixed by the cross section for elastic WIMP-nucleus
scattering. Here we calculate the contribution to this cross section from
two-nucleon currents from pion exchange in the nucleus, and show that it may in
some cases be comparable to the one-nucleon current that has been considered in
prior work, and perhaps help resolve the discrepancies between the various
direct dark-matter search experiments. We provide simple expressions that allow
these new contributions to be included in current calculations.


  We study the classic correlation clustering in the dynamic setting. Given $n$
objects and a complete labeling of the object-pairs as either similar or
dissimilar, the goal is to partition the objects into arbitrarily many clusters
while minimizing disagreements with the labels. In the dynamic setting, an
update consists of a flip of a label of an edge. In a breakthrough result,
[BDHSS, FOCS'19] showed how to maintain a 3-approximation with polylogarithmic
update time by providing a dynamic implementation of the Pivot algorithm of
[ACN, STOC'05]. Since then, it has been a major open problem to determine
whether the 3-approximation barrier can be broken in the fully dynamic setting.
In this paper, we resolve this problem. Our algorithm, Modified Pivot, locally
improves the output of Pivot by moving some vertices to other existing clusters
or new singleton clusters. We present an analysis showing that this
modification does indeed improve the approximation to below 3. We also show
that its output can be maintained in polylogarithmic time per update.


  We study localization properties of principal eigenvector (PEV) of multilayer
networks. Starting with a multilayer network corresponding to a delocalized
PEV, we rewire the network edges using an optimization technique such that the
PEV of the rewired multilayer network becomes more localized. The framework
allows us to scrutinize structural and spectral properties of the networks at
various localization points during the rewiring process. We show that rewiring
only one-layer is enough to attain a multilayer network having a highly
localized PEV. Our investigation reveals that a single edge rewiring of the
optimized multilayer network can lead to the complete delocalization of a
highly localized PEV. This sensitivity in the localization behavior of PEV is
accompanied by a pair of almost degenerate eigenvalues. This observation opens
an avenue to gain a deeper insight into the origin of PEV localization of
networks. Furthermore, analysis of multilayer networks constructed using
real-world social and biological data show that the localization properties of
these real-world multilayer networks are in good agreement with the simulation
results for the model multilayer network. The study is relevant to applications
that require understanding propagation of perturbation in multilayer networks.


  Orthogonality is a fundamental theme in representation theory and Fourier
analysis. An orthogonality relation for characters of finite abelian groups
(now recognized as an orthogonality relation on $\mathrm{GL}(1)$) was used by
Dirichlet to prove infinitely many primes in arithmetic progressions.
Orthogonality relations for $\mathrm{GL}(2)$ and $\mathrm{GL}(3)$ have been
worked on by many researchers with a broad range of applications to number
theory. We present here, for the first time, very explicit orthogonality
relations for the real group $\mathrm{GL}(4,\mathbb{R})$ with a power savings
error term. The proof requires novel techniques in the computation of the
geometric side of the Kuznetsov trace formula. An appendix by Bingrong Huang
gives new bounds for the relevant Kloosterman sums.


  Nonlinear hydrodynamic equations for visco-elastic media are discussed. We
start from the recently derived fully hydrodynamic nonlinear description of
permanent elasticity that utilizes the (Eulerian) strain tensor. The reversible
quadratic nonlinearities in the strain tensor dynamics are of the 'lower
convected' type, unambiguously. Replacing the (often neglected) strain
diffusion by a relaxation of the strain as a minimal ingredient, a generalized
hydrodynamic description of viscoelasticity is obtained. This can be used to
get a nonlinear dynamic equation for the stress tensor (sometimes called
constitutive equation) in terms of a power series in the variables. The form of
this equation and in particular the form of the nonlinear convective term is
not universal but depends on various material parameters. A comparison with
existing phenomenological models is given. In particular we discuss how these
ad-hoc models fit into the hydrodynamic description and where the various
non-Newtonian contributions are coming from.


  A comparative study of various parametrizations of the dark energy equation
of state is made. Astrophysical constraints from LSS, CMB and BBN are laid down
to test the physical viability and cosmological compatibility of these
parametrizations. A critical evaluation of the 4-index parametrizations reveals
that Hannestad-M\"{o}rtsell as well as Lee parametrizations are simple and
transparent in probing the evolution of the dark energy during the expansion
history of the universe and they satisfy the LSS, CMB and BBN constraints on
the dark energy density parameter for the best fit values.


  The multiparticle entanglement in the Lipkin-Meshkov-Glick model has been
discussed extensively in this paper. Measured by the global entanglement and
its generalization, our calculation shows that the multiparticle entanglement
can faithfully detect quantum phase transitions. For an antiferromagnetic case
the multiparticle entanglement reaches the maximum at the transition point,
whereas for ferromagnetic coupling, two different behaviors of multiparticle
entanglement can be identified, dependent on the anisotropic parameter in the
coupling.


  The variation of dark energy density with redshift, $\rho_X(z)$, provides a
critical clue to the nature of dark energy. Since $\rho_X(z)$ depends on the
dark energy equation of state $w_X(z)$ through an integral, $\rho_X(z)$ can be
constrained more tightly than $w_X(z)$ given the same observational data. We
demonstrate this explicitly using current type Ia supernova (SN Ia) data [the
Tonry/Barris sample], together with the Cosmic Microwave Background (CMB) shift
parameter from CMB data (WMAP, CBI, and ACBAR), and the large scale structure
(LSS) growth factor from 2dF galaxy survey data. We assume a flat universe, and
use Markov Chain Monte Carlo (MCMC) technique in our analysis. We find that,
while $w_X(z)$ extracted from current data is consistent with a cosmological
constant at 68% C.L., $\rho_X(z)$ (which has far smaller uncertainties) is not.
Our results clearly show the advantage of using $\rho_X(z)$, instead of
$w_X(z)$, to probe dark energy.


  This paper considers a variation of the classical two-user interference
channel where the communication of two interfering source-destination pairs is
aided by an additional node that has a priori knowledge of the messages to be
transmitted, which is referred to as the it cognitive relay. For this
Interference Channel with a Cognitive Relay (ICCR) In particular, for the class
of injective semi-deterministic ICCRs, a sum-rate upper bound is derived for
the general memoryless ICCR and further tightened for the Linear Deterministic
Approximation (LDA) of the Gaussian noise channel at high SNR, which disregards
the noise and focuses on the interaction among the users' signals. The capacity
region of the symmetric LDA is completely characterized except for the regime
of moderately weak interference and weak links from the CR to the destinations.
The insights gained from the analysis of the LDA are then translated back to
the symmetric Gaussian noise channel (GICCR). For the symmetric GICCR, an
approximate characterization (to within a constant gap) of the capacity region
is provided for a parameter regime where capacity was previously unknown. The
approximately optimal scheme suggests that message cognition at a relay is
beneficial for interference management as it enables simultaneous over the air
neutralization of the interference at both destinations.


  We measured the chemical composition and the size distribution of aerosols
generated by femtosecond-Terawatt laser pulses in the atmosphere using an
aerosol mass spectrometer (AMS). We show that nitric acid condenses in the form
of ammonium nitrate, and that oxidized volatile organics also contribute to
particle growth. These two components account for two thirds and one third,
respectively, of the dry laser-condensed mass. They appear in two different
modes centred at 380 nm and 150 nm. The number concentration of particles
between 25 and 300 nm increases by a factor of 15. Pre-existing water droplets
strongly increase the oxidative properties of the laser-activated atmosphere,
substantially enhancing the condensation of organics under laser illumination.


  We explore the properties of weakly bound bosonic states in the strongly
interacting regime. Combining a correlated-Gaussian (CG) basis set expansion
with a complex scaling method, we extract the energies and structural
properties of bosonic cluster states with $N\le6$ for different two-body
potentials. The identification of five- and six-body resonances attached to an
excited Efimov trimer provides strong support to the premise of Efimov
universality in bosonic systems. Our study also reveals a rich structure of
bosonic cluster states. Besides the lowest cluster states which behave as
bosonic droplets, we identify cluster states weakly bound to one or two atoms
forming effective cluster-atom "dimers" and cluster-atom-atom "trimers." The
experimental signatures of these cluster states are discussed.


  Counting the number of answers to conjunctive queries is a fundamental
problem in databases that, under standard assumptions, does not have an
efficient solution. The issue is inherently #P-hard, extending even to classes
of acyclic instances.
  To address this, we pinpoint tractable classes by examining the structural
properties of instances and introducing the novel concept of #-hypertree
decomposition. We establish the feasibility of counting answers in polynomial
time for classes of queries featuring bounded #-hypertree width. Additionally,
employing novel techniques from the realm of fixed-parameter computational
complexity, we prove that, for bounded arity queries, the bounded #-hypertree
width property precisely delineates the frontier of tractability for the
counting problem. This result closes an important gap in our understanding of
the complexity of such a basic problem for conjunctive queries and,
equivalently, for constraint satisfaction problems (CSPs).
  Drawing upon #-hypertree decompositions, a ''hybrid'' decomposition method
emerges. This approach leverages both the structural characteristics of the
query and properties intrinsic to the input database, including keys or other
(weaker) degree constraints that limit the permissible combinations of values.
Intuitively, these features may introduce distinct structural properties that
elude identification through the ''worst-possible database'' perspective
inherent in purely structural methods.


  In this paper, we consider the singularity category $D_{sg}(\mod A)$ and the
$\mathbb{Z}$-graded singularity category $D_{sg}(\mod^{\mathbb Z} A)$ for a
Gorenstein monomial algebra $A$. Firstly, for a positively graded
$1$-Gorenstein algebra, we prove that its ${\mathbb Z}$-graded singularity
category admits silting objects. Secondly, for $A=KQ/I$ being a Gorenstein
monomial algebra, we prove that $D_{sg}(\mod^{\mathbb Z} A)$ has tilting
objects. As a consequence, $D_{sg}(\mod^{\mathbb Z}A)$ is triangulated
equivalent to the derived category of a hereditary algebra $H$ which is of
finite representation type. Finally, we give a characterization of
$1$-Gorenstein monomial algebras, and describe their singularity categories
clearly by using the triangulated orbit categories of type ${\mathbb A}$.


  The goal of this paper is automatic character-aware subtitle generation.
Given a video and a minimal amount of metadata, we propose an audio-visual
method that generates a full transcript of the dialogue, with precise speech
timestamps, and the character speaking identified. The key idea is to first use
audio-visual cues to select a set of high-precision audio exemplars for each
character, and then use these exemplars to classify all speech segments by
speaker identity. Notably, the method does not require face detection or
tracking. We evaluate the method over a variety of TV sitcoms, including
Seinfeld, Fraiser and Scrubs. We envision this system being useful for the
automatic generation of subtitles to improve the accessibility of the vast
amount of videos available on modern streaming services. Project page :
\url{https://www.robots.ox.ac.uk/~vgg/research/look-listen-recognise/}


  We study non-invariant Killing tensors with non-zero Nijenhuis torsion in the
three-dimensional Euclidean space. Generalizing the corresponding integrable
systems we construct two new families of superintegrable systems in
$n$-dimensional Euclidean space.


  Employing uplift formulae, we uplift supersymmetric $AdS_6$ black holes from
$F(4)$ gauged supergravity to massive type IIA and type IIB supergravity. In
massive type IIA supergravity, we obtain supersymmetric $AdS_6$ black holes
asymptotic to the Brandhuber-Oz solution. In type IIB supergravity, we obtain
supersymmetric $AdS_6$ black holes asymptotic to the non-Abelian T-dual of the
Brandhuber-Oz solution. For the uplifted black hole solutions, we calculate the
holographic entanglement entropy. In massive type IIA supergravity, it
precisely matches the Bekenstein-Hawking entropy of the black hole solutions.


  By considering the least-squares fits of the double-mode Cepheid light curves
discussed in Paper I we defined their properties by their Fourier parameters
and generalized phase differences $G_{i,j}$. When plotting the latter
quantities as a function of the respective order, the second order terms are
confined in the region just below 3/2$\pi$; the third order terms have $\pi/2 <
G_{i,j} < \pi$, the fourth order ones cluster around 2$\pi$ (or 0), the fifth
order ones seem to have $\pi < G_{i,j} < 3/2 \pi$. The mean $G_{i,j}$ values
are also regularly spaced. The progression of the $G_{i,j}$ values as a
function of the period was investigated and the signature of a possible
resonance near 6.0 d was found.


  An electron-positron collider operating at a center-of-mass energy $E_{CM}$
can collect events at all lower energies through initial-state radiation (ISR
or radiative return). We explore the capabilities for radiative return studies
by a proposed high-luminosity collider at $E_{CM}$ = 250 or 90 GeV, to fill in
gaps left by lower-energy colliders such as PEP, PETRA, TRISTAN, and LEP. These
capabilities are compared with those of the lower-energy $e^+e^-$ colliders as
well as hadron colliders such as the Tevatron and the CERN Large Hadron
Collider (LHC). Some examples of accessible questions in dark photon searches
and heavy flavor spectroscopy are given.


  In a smart home system, multiple users have access to multiple devices,
typically through a dedicated app installed on a mobile device. Traditional
access control mechanisms consider one unique trusted user that controls the
access to the devices. However, multi-user multi-device smart home settings
pose fundamentally different challenges to traditional single-user systems. For
instance, in a multi-user environment, users have conflicting, complex, and
dynamically changing demands on multiple devices, which cannot be handled by
traditional access control techniques. To address these challenges, in this
paper, we introduce Kratos, a novel multiuser and multi-device-aware access
control mechanism that allows smart home users to flexibly specify their access
control demands. Kratos has three main components: user interaction module,
backend server, and policy manager. Users can specify their desired access
control settings using the interaction module which are translated into access
control policies in the backend server. The policy manager analyzes these
policies and initiates negotiation between users to resolve conflicting demands
and generates final policies. We implemented Kratos and evaluated its
performance on real smart home deployments featuring multi-user scenarios with
a rich set of configurations (309 different policies including 213 demand
conflicts and 24 restriction policies). These configurations included five
different threats associated with access control mechanisms. Our extensive
evaluations show that Kratos is very effective in resolving conflicting access
control demands with minimal overhead and robust against different attacks.


  Lithium niobate (LNO) is a well established material for surface acoustic
wave (SAW) devices including resonators, delay lines and filters. Recently,
multi-layer substrates based on LNO thin films have become commercially
available. Here, we present a systematic low-temperature study of the
performance of SAW devices fabricated on LNO-on-insulator and LNO-on-Silicon
substrates and compare them to bulk LNO devices. Our study aims at assessing
the performance of these substrates for quantum acoustics, i.e. the integration
with superconducting circuits operating in the quantum regime. To this end, we
design SAW resonators with a target frequency of 5 GHz and perform experiments
at millikelvin temperatures and microwave power levels corresponding to single
photons or phonons. The devices are investigated regarding their internal
quality factors as a function of the excitation power and temperature, which
allows us to characterize and quantify losses and identify the dominating loss
mechanism. For the measured devices, fitting the experimental data shows that
the quality factors are limited by the coupling of the resonator to a bath of
two-level-systems. Our results suggest that SAW devices on thin film LNO on
silicon have comparable performance to devices on bulk LNO and are viable for
use in SAW-based quantum acoustic devices.


  We present a study of magnetic profiles of umbral dots (UDs) and its
consequences on the Joule heating mechanisms. Hamedivafa (2003) studied Joule
heating using vertical component of magnetic field. In this paper UDs magnetic
profile has been investigated including the new azimuthal component of magnetic
field which might explain the relatively larger enhancement of Joule heating
causing more brightness near circumference of UD.


  Using purely combinatorial methods we calculate the first degree cohomology
of Specht modules indexed by two part partitions over fields of characteristic
$p\ge 3$. These combinatorial methods also allow us to obtain an explicit
description of all of the non-split extensions of the Specht module,
$S^\lambda$, by the trivial module. Applying this work to partitions with more
than two parts we are able to give an entirely combinatorial proof of the bound
on the dimension of the first degree cohomology given by work of Donkin and
Geranios. We also obtain as a corollary a result of Weber giving a far reaching
condition determining partitions for which the first cohomology of the Specht
module is trivial.


  A variety of fan-based wikis about episodic fiction (e.g., television shows,
novels, movies) exist on the World Wide Web. These wikis provide a wealth of
information about complex stories, but if readers are behind in their viewing
they run the risk of encountering "spoilers" -- information that gives away key
plot points before the intended time of the show's writers. Enterprising
readers might browse the wiki in a web archive so as to view the page prior to
a specific episode date and thereby avoid spoilers. Unfortunately, due to how
web archives choose the "best" page, it is still possible to see spoilers
(especially in sparse archives).
  In this paper we discuss how to use Memento to avoid spoilers. Memento uses
TimeGates to determine which best archived page to give back to the user,
currently using a minimum distance heuristic. We quantify how this heuristic is
inadequate for avoiding spoilers, analyzing data collected from fan wikis and
the Internet Archive. We create an algorithm for calculating the probability of
encountering a spoiler in a given wiki article. We conduct an experiment with
16 wiki sites for popular television shows. We find that 38% of those pages are
unavailable in the Internet Archive. We find that when accessing fan wiki pages
in the Internet Archive there is as much as a 66% chance of encountering a
spoiler. Using sample access logs from the Internet Archive, we find that 19%
of actual requests to the Wayback Machine for wikia.com pages ended in
spoilers. We suggest the use of a different minimum distance heuristic,
minpast, for wikis, using the desired datetime as an upper bound.


  We reexamine two-dimensional Lorentzian conformal field theory using the
formalism previously developed in a study of sine-square deformation of
Euclidean conformal field theory. We construct three types of Virasoro algebra.
One of them reproduces the result by L\"uscher and Mack, while another type
exhibits the divergence in the central charge term. The other leads the
continuous spectrum and contains no closed time-like curve in the system.


  Using Cartan's Method of Equivalence, we prove an upper bound for the
generality of generic rank-1 B\"acklund transformations relating two hyperbolic
Monge-Amp\`ere systems. In cases when the B\"acklund transformation admits a
symmetry group whose orbits have codimension 1, 2, or 3, we obtain
classification results and new examples of auto-B\"acklund transformations.


  We calculate the finite temperature single hole spectral function and the
spin dynamic structure factor of spinfull one-dimensional Tomonaga-Luttinger
liquid. Analytical expressions are obtained for a number of special cases. We
also calculate the single hole spectral function of a spin gapped Luther-Emery
liquid and obtain exact results at the free fermion point K_s=1/2. These
results may be applied to the analysis of angle resolved photoemission and
neutron scattering experiments on quasi-one-dimensional materials.


  The galaxies form and evolve in the early epochs through the anisotropic
merging process along the primary narrow filaments, in the direction of which
their shapes become elongated and intrinsically aligned. The nonlinear
evolution of the cosmic web broadens the primary filaments, by entangling them
with multiple secondary filaments, which has an effect of reducing the
anisotropy of the merging process and in consequence weakens the galaxy
shape-shape correlations in the later epochs. Assuming that the degree of the
nonlinearity and complexity of the cosmic web depends on the nature of dark
matter, we propose a hypothesis that the galaxy shape-shape correlation
function, $\eta(r)$, may be a powerful complimentary probe of the total
neutrino mass, $M_{\nu}$. Testing this hypothesis against a high resolution
N-body simulation, we show that the $M_{\nu}$-dependence of $\eta(r)$ at $z=0$
is sensitive enough to distinguish between $M_{\nu}=0.0$ eV and $M_{\nu}=0.1$
eV. We also show that the differences in $\eta(r)$ at $r\le 5\,h^{-1}$Mpc
between the models with massless and massive neutrinos cannot be explained by
their differences in the small-scale density powers, $\sigma_{8}$, which
implies that the galaxy shape-shape correlation function has a potential to
break the notorious cosmic degeneracy between $M_{\nu}$ and $\sigma_{8}$.


  Structural parameter identifiability is a property of a differential model
with parameters that allows for the parameters to be determined from the model
equations in the absence of noise. One of the standard approaches to assessing
this problem is via input-output equations and, in particular, characteristic
sets of differential ideals. The precise relation between identifiability and
input-output identifiability is subtle. The goal of this note is to clarify
this relation. The main results are:
  1) identifiability implies input-output identifiability;
  2) these notions coincide if the model does not have rational first
integrals;
  3) the field of input-output identifiable functions is generated by the
coefficients of a "minimal" characteristic set of the corresponding
differential ideal.
  We expect that some of these facts may be known to the experts in the area,
but we are not aware of any articles in which these facts are stated precisely
and rigorously proved.