  We discuss the asymptotic-preserving properties of a hybridizable
discontinuous Galerkin method for the Westervelt model of ultrasound waves.
More precisely, we show that the proposed method is robust with respect to
small values of the sound diffusivity damping parameter~$\delta$ by deriving
low- and high-order energy stability estimates, and \emph{a priori} error
bounds that are independent of~$\delta$. Such bounds are then used to show
that, when~$\delta \rightarrow 0^+$, the method remains stable and the discrete
acoustic velocity potential~$\psi_h^{(\delta)}$ converges to~$\psi_h^{(0)}$,
where the latter is the singular vanishing dissipation limit. Moreover, we
prove optimal convergence for the approximation of the acoustic particle
velocity variable~$\bv = \nabla \psi$. The established theoretical results are
illustrated with some numerical experiments.


  The purpose of this expository article is to revisit the notions of
amenability and ergodicity, and to point out that they appear for topological
groups that are not necessarily locally compact in articles by Bogolyubov
(1939), Fomin (1950), Dixmier (1950), and Rickert (1967).


  Arbitrary regularization dependent parameters in Quantum Field Theory are
usually fixed on symmetry or phenomenology grounds. We verify that the
quadratically divergent behavior responsible for the lack of naturalness in the
Standard Model (SM) is intrinsically arbitrary and regularization dependent.
While quadratic divergences are welcome for instance in effective models of low
energy QCD, they pose a problem in the SM treated as an effective theory in the
Higgs sector. Being the very existence of quadratic divergences a matter of
debate, a plausible scenario is to search for a symmetry requirement that could
fix the arbitrary coefficient of the leading quadratic behavior to the Higgs
boson mass to zero. We show that this is possible employing consistency of
scale symmetry breaking by quantum corrections. Besides eliminating a
fine-tuning problem and restoring validity of perturbation theory, this
requirement allows to construct bounds for the Higgs boson mass in terms of
$\delta m^2/m^2_H$ (where $m_H$ is the renormalized Higgs mass and $\delta m^2$
is the 1-loop Higgs mass correction). Whereas $\delta m^2/m^2_H<1$
(perturbative regime) in this scenario allows the Higgs boson mass around the
current accepted value, the inclusion of the quadratic divergence demands
$\delta m^2/m^2_H$ arbitrarily large to reach that experimental value.


  This paper presents a realistic, stochastic, and local model that reproduces
nonrelativistic quantum mechanics (QM) results without using its mathematical
formulation. The proposed model only uses integer-valued quantities and
operations on probabilities, in particular assuming a discrete spacetime under
the form of a Euclidean lattice. Individual (spinless) particle trajectories
are described as random walks. Transition probabilities are simple functions of
a few quantities that are either randomly associated to the particles during
their preparation, or stored in the lattice nodes they visit during the walk.
QM predictions are retrieved as probability distributions of similarly-prepared
ensembles of particles. The scenarios considered to assess the model comprise
of free particle, constant external force, harmonic oscillator, particle in a
box, the Delta potential, particle on a ring, particle on a sphere and include
quantization of energy levels and angular momentum.


  Results from the calculation of the basic characteristics of the photonic
crystal fiber with two rings of holes are presented by the approach which takes
into account the exact distribution of the refractive index over the cross
section of the photonic crystal fiber. Formulae are theoretically derived for
the calculation of holes with arbitrary shapes by dividing the material within
them into rotated at different angles rectangles.
  Keywords: photonic crystal fibre, Galerkin method, a set of sine functions,
local coordinate systems.


  In this paper we address the problem of unsupervised gaze correction in the
wild, presenting a solution that works without the need for precise annotations
of the gaze angle and the head pose. We have created a new dataset called
CelebAGaze, which consists of two domains X, Y, where the eyes are either
staring at the camera or somewhere else. Our method consists of three novel
modules: the Gaze Correction module (GCM), the Gaze Animation module (GAM), and
the Pretrained Autoencoder module (PAM). Specifically, GCM and GAM separately
train a dual in-painting network using data from the domain $X$ for gaze
correction and data from the domain $Y$ for gaze animation. Additionally, a
Synthesis-As-Training method is proposed when training GAM to encourage the
features encoded from the eye region to be correlated with the angle
information, resulting in a gaze animation which can be achieved by
interpolation in the latent space. To further preserve the identity
information~(e.g., eye shape, iris color), we propose the PAM with an
Autoencoder, which is based on Self-Supervised mirror learning where the
bottleneck features are angle-invariant and which works as an extra input to
the dual in-painting models. Extensive experiments validate the effectiveness
of the proposed method for gaze correction and gaze animation in the wild and
demonstrate the superiority of our approach in producing more compelling
results than state-of-the-art baselines. Our code, the pretrained models and
the supplementary material are available at:
https://github.com/zhangqianhui/GazeAnimation.


  In the present paper, we perform a sub-Planckian quantum mode analysis of
linear cosmological perturbation in the inflaton field over a classical quasi
de-Siter metric background by dynamical horizon exit (DHE) method. In this way,
we probe the inflationary regime of a quintessential $\alpha$-attractor model
by analysing the COBE/Planck normalized power spectra, spectral indices, tensor
to scalar ratio, number of e-folds, running of the spectral index and
inflationary Hubble parameter in $k$-space. We compare our results with
ordinary $\alpha$-attractor $E$ and $T$ models and with that of Planck-2018
results. Our estimated values of $n_s$ and $r$ lie within $68\%$ CL with
respect to Planck data for $k=0.001 - 0.009$ Mpc$^{-1}$ for all values of
$\alpha$. The $\alpha$ values, obtained in our calculations satisfy various
post inflationary constraints regarding preheating and reheating, reported in
current literature. We observe that quintessence sets an upper bound of
$\alpha=4.3$ and thereby restricts the model from becoming of the power law
type, making it more efficacious than ordinary $\alpha$-attractors in
explaining both inflation and dark energy. A striking observation in our
analyses is that, unlike in our previous study, we find a continuous values of
$\alpha$ within $\frac{1}{10}\leq \alpha\leq 4.3$ for the specified $k$ range.
At the end, we have shown that the model parameters constrained in this work
give a very small vacuum density $\sim 10^{-117}-10^{-115} M_P^4$ which is an
essential criterion for current and future dark energy observations of the
universe.


  We compute the self-force acting on an electric charge at rest in
Schwarzschild-de Sitter spacetimes, allowing the cosmological constant to be
either positive or negative. In the case of a positive cosmological constant,
we show that the self-force is always positive, representing a repulsion from
the black hole, and monotonically decreasing with increasing distance from the
black hole. The spectrum of results is richer in the case of a negative
cosmological constant. Here the self-force is not always positive --- it is
negative when the black-hole and cosmological scales are comparable and the
charge is close to the black hole --- and not always monotonically decreasing
--- it is actually monotonically increasing when the cosmological scale is
sufficiently small compared to the black-hole scale. The self-force also
approaches a constant asymptotic value when the charge is moved to large
cosmological distances; this feature can be explained in terms of an
interaction between the charge and the conformal boundary at infinity, which
acts as a grounded conductor.


  Vision-Language Models pre-trained on large-scale image-text datasets have
shown superior performance in downstream tasks such as image retrieval. Most of
the images for pre-training are presented in the form of open domain
common-sense visual elements. Differently, video covers in short video search
scenarios are presented as user-originated contents that provide important
visual summaries of videos. In addition, a portion of the video covers come
with manually designed cover texts that provide semantic complements. In order
to fill in the gaps in short video cover data, we establish the first
large-scale cover-text benchmark for Chinese short video search scenarios.
Specifically, we release two large-scale datasets CBVS-5M/10M to provide short
video covers, and the manual fine-labeling dataset CBVS-20K to provide real
user queries, which serves as an image-text benchmark test in the Chinese short
video search field. To integrate the semantics of cover text in the case of
modality missing, we propose UniCLIP where cover texts play a guiding role
during training, however are not relied upon by inference. Extensive evaluation
on CBVS-20K demonstrates the excellent performance of our proposal. UniCLIP has
been deployed to Tencent's online video search systems with hundreds of
millions of visits and achieved significant gains. The dataset and code are
available at https://github.com/QQBrowserVideoSearch/CBVS-UniCLIP.


  In this paper we describe the geodesics of a left-invariant sub-Riemannian
metric on the three-dimensional solvable Lie group $SOLV^-$.


  Analog electronic and optical computing exhibit tremendous advantages over
digital computing for accelerating deep learning when operations are executed
at low precision. In this work, we derive a relationship between analog
precision, which is limited by noise, and digital bit precision. We propose
extending analog computing architectures to support varying levels of precision
by repeating operations and averaging the result, decreasing the impact of
noise. Such architectures enable programmable tradeoffs between precision and
other desirable performance metrics such as energy efficiency or throughput. To
utilize dynamic precision, we propose a method for learning the precision of
each layer of a pre-trained model without retraining network weights. We
evaluate this method on analog architectures subject to a variety of noise
sources such as shot noise, thermal noise, and weight noise and find that
employing dynamic precision reduces energy consumption by up to 89% for
computer vision models such as Resnet50 and by 24% for natural language
processing models such as BERT. In one example, we apply dynamic precision to a
shot-noise limited homodyne optical neural network and simulate inference at an
optical energy consumption of 2.7 aJ/MAC for Resnet50 and 1.6 aJ/MAC for BERT
with <2% accuracy degradation.


  We introduce a bond portfolio management theory based on foundations similar
to those of stock portfolio management. A general continuous-time zero-coupon
market is considered. The problem of optimal portfolios of zero-coupon bonds is
solved for general utility functions, under a condition of no-arbitrage in the
zero-coupon market. A mutual fund theorem is proved, in the case of
deterministic volatilities. Explicit expressions are given for the optimal
solutions for several utility functions.


  We investigate hadron production as well as transverse hadron spectra in
nucleus-nucleus collisions from 2 $A\cdot$GeV to 21.3 $A\cdot$TeV within two
independent transport approaches (UrQMD and HSD) that are based on quark,
diquark, string and hadronic degrees of freedom. The comparison to experimental
data demonstrates that both approaches agree quite well with each other and
with the experimental data on hadron production. The enhancement of pion
production in central Au+Au (Pb+Pb) collisions relative to scaled $pp$
collisions (the 'kink') is well described by both approaches without involving
any phase transition. However, the maximum in the $K^+/\pi^+$ ratio at 20 to 30
A$\cdot$GeV (the 'horn') is missed by $\sim$ 40%. A comparison to the
transverse mass spectra from $pp$ and C+C (or Si+Si) reactions shows the
reliability of the transport models for light systems. For central Au+Au
(Pb+Pb) collisions at bombarding energies above $\sim$ 5 A$\cdot$GeV, however,
the measured $K^{\pm}$ $m_{T}$-spectra have a larger inverse slope parameter
than expected from the calculations. The approximately constant slope of
$K^\pm$ spectra at SPS (the 'step') is not reproduced either. Thus the pressure
generated by hadronic interactions in the transport models above $\sim$ 5
A$\cdot$GeV is lower than observed in the experimental data. This finding
suggests that the additional pressure - as expected from lattice QCD
calculations at finite quark chemical potential and temperature - might be
generated by strong interactions in the early pre-hadronic/partonic phase of
central Au+Au (Pb+Pb) collisions.


  Recent studies have suggested the possibility that the lightest
supersymmetric particle is a suitable dark matter candidate. In this
theoretical framework, annihilations in high density environments like the
center of dark matter haloes may produce an intense flux of gamma-rays. In this
paper we discuss the possibility of detecting the signatures of neutralino
annihilation in nearby galaxies with next generation ground-based detectors.


  We present a sample of mid-infrared detected sources from the European Large
Area ISO Survey (ELAIS) regions characterised by strong mid-IR radiation with
faint near-IR and optical counterparts. These extreme mid-to-near-IR objects
(EMNOs) are defined here by a flux ratio of f_15um / f_2.2um > 25. This
population is not obvious in deeper small area ISO surveys, though it produces
more than 20% of the observed cosmic IR background radiation (CIRB) at 15um
above 1 mJy. Near-future large area deep mid-IR surveys with the Spitzer Space
Telescope, however, are bound to uncover large amounts of these objects, which
we argue to most likely be obscured AGN, based on SED shapes and X-ray data.
Very strong dusty starbursts at z>1 may also have high mid-to-near-IR flux
ratios, but using the MIR/NIR and FIR/MIR ratios these may be separated. Most
of our EMNOs appear to be ULIRGs, half are also extremely red objects (ERO). A
curious case of a low redshift, less luminous object with a very young stellar
population is also found. We predict that the simple broad band selection
method makes EMNOs a useful window into high-redshift obscured nuclear activity
and its sought after relation to star-formation, in a similar way that EROs
have been used to define samples of high-redshift early type galaxies.


  Presently, it is unclear whether the Eddington ratio and radiative efficiency
depend upon a supermassive black hole's (SMBH's) redshift z and mass MBH. We
attempt to resolve this issue using published data for 132,000 SMBHs with MBH
>1E+7 Msun (solar masses) at ~0.1<z<2.4 covering ~10 billion years of cosmic
time, with MBH determined using MgII lines and bolometric luminosities (Lbol)
based on a weighted mean of Lbol from two or more monochromatic luminosities
and a single uniformly applied correction factor. The SMBHs are sorted into 7
MBH bins separated from each other by half an order of magnitude. The Eddington
ratio and z data in each bin are subjected to spline regression analysis. The
results unambiguously show that for similar-size SMBHs, the Eddington ratio
decreases as z decreases and that for a given redshift larger SMBHs have a
lower Eddington ratio. These findings require that either a SMBH's accretion
rate and/or its radiative efficiency be a function of z and MBH and, in the
context of the Bondi accretion model, imply that radiative efficiency is an
inverse function of a SMBH's redshift z and mass MBH. These findings suggest
that SMBHs become less efficient (higher radiative efficiency) in accreting
gases as the ambient gas density decreases with z and that larger SMBHs are
more efficient (lower radiative efficiency) than smaller ones. The results
leave little doubt that the current widespread practice of assigning radiative
efficiency a standard value is untenable and gives erroneous estimates of
accretion rates and growth times of SMBHs.


  Recently deeplearning models have been shown to be capable of making
remarkable performance in sentences and documents classification tasks. In this
work, we propose a novel framework called AC-BLSTM for modeling sentences and
documents, which combines the asymmetric convolution neural network (ACNN) with
the Bidirectional Long Short-Term Memory network (BLSTM). Experiment results
demonstrate that our model achieves state-of-the-art results on five tasks,
including sentiment analysis, question type classification, and subjectivity
classification. In order to further improve the performance of AC-BLSTM, we
propose a semi-supervised learning framework called G-AC-BLSTM for text
classification by combining the generative model with AC-BLSTM.


  Despite the impressive advances in biological imaging, no imaging modality
today generates, in a comprehensive manner, high-resolution images of crowded
molecules working deep inside the living cell in real time. In this paper,
instead of tackling this engineering problem in the hope of solving it, we ask
a converse question: What if such imaging is \emph{fundamentally} impossible?
We argue that certain decoherence processes could be suppressed because the
internal workings of the cell are not being closely "observed" in the quantum
mechanical sense, as implied by the assumed impossibility of imaging. It is
certainly true that the "wet and warm" living cell should not exhibit quantum
behavior merely because of the lack of observation. Despite this, we plow ahead
to see what \emph{might} result from such absence of the outward flow of
information. We suggest that chaotic dynamics in the cell could be quantum
mechanically suppressed --- a known phenomenon in quantum chaology, which is
potentially resistant to various mechanisms for the emergence of classicality.
We also consider places where experimental evidence for/against such a
possibility may be sought.


  Our recent paper reports the experimental realization of a one-atom laser in
a regime of strong coupling (Ref. [1]). Here we provide the supporting
theoretical analysis relevant to the operating regime of our experiment. By way
of a simplified four-state model, we investigate the passage from the domain of
conventional laser theory into the regime of strong coupling for a single
intracavity atom pumped by coherent external fields. The four-state model is
also employed to exhibit the vacuum-Rabi splitting and to calculate the optical
spectrum. We next extend this model to incorporate the relevant Zeeman
hyperfine states as well as a simple description of the pumping processes in
the presence of polarization gradients and atomic motion. This extended model
is employed to make quantitative comparisons with the measurements of Ref. [1]
for the intracavity photon number versus pump strength and for the photon
statistics as expressed by the intensity correlation function g2(tau).


  We have studied the proximity-induced superconducting triplet pairing in
CoO$_x$/Py1/Cu/Py2/Cu/Pb spin-valve structure (where Py =
Ni$_{0.81}$Fe$_{0.19}$). By optimizing the parameters of this structure we
found a triplet channel assisted full switching between the normal and
superconducting states. To observe an "isolated" triplet spin-valve effect we
exploited the oscillatory feature of the magnitude of the ordinary spin-valve
effect $\Delta T_c$ in the dependence of the Py2-layer thickness $d_{Py2}$. We
determined the value of $d_{Py2}$ at which $\Delta T_c$ caused by the ordinary
spin-valve effect (the difference in the superconducting transition temperature
$T_c$ between the antiparallel and parallel mutual orientation of
magnetizations of the Py1 and Py2 layers) is suppressed. For such a sample a
"pure" triplet spin-valve effect which causes the minimum in $T_c$ at the
orthogonal configuration of magnetizations has been observed.


  Among the different platforms to engineer Majorana fermions in
one-dimensional topological superconductors, topological insulator nanowires
remain a promising option. Threading an odd number of flux quanta through these
wires induces an odd number of surface channels, which can then be gapped with
proximity induced pairing. Because of the flux and depending on energetics, the
phase of this surface pairing may or may not wind around the wire in the form
of a vortex. Here we show that for wires with discrete rotational symmetry,
this vortex is necessary to produce a fully gapped topological superconductor
with localized Majorana end states. Without a vortex the proximitized wire
remains gapless, and it is only if the symmetry is broken by disorder that a
gap develops, which is much smaller than the one obtained with a vortex. These
results are explained with the help of a continuum model and validated
numerically with a tight binding model, and highlight the benefit of a vortex
for reliable use of Majorana fermions in this platform.


  High efficiency in precision farming depends on accurate tools to perform
weed detection and mapping of crops. This allows for precise removal of harmful
weeds with a lower amount of pesticides, as well as increase of the harvest's
yield by providing the farmer with valuable information. In this paper, we
address the problem of fully automatic stem detection from image data for this
purpose. Our approach runs on mobile agricultural robots taking RGB images.
After processing the images to obtain a vegetation mask, our approach separates
each plant into its individual leaves and later estimates a precise stem
position. This allows an upstream mapping algorithm to add the high-resolution
stem positions as a semantic aggregate to the global map of the robot, which
can be used for weeding and for analyzing crop statistics. We implemented our
approach and thoroughly tested it on three different datasets with vegetation
masks and stem position ground truth. The experiments presented in this paper
conclude that our module is able to detect leaves and estimate the stem's
position at a rate of 56 Hz on a single CPU. We furthermore provide the
software to the community.


  Let $p$ be an odd prime, and let $K/K_0$ be a quadratic extension of number
fields. Denote by $K_\pm$ the maximal $\mathbb{Z}_p$-power extensions of $K$
that are Galois over $K_0$, with $K_+$ abelian over $K_0$ and $K_-$ dihedral
over $K_0$. In this paper we show that for a Galois representation over $K_0$
satisfying certain hypotheses, if it has odd Selmer rank over $K$ then for one
of $K_\pm$ its Selmer rank over $L$ is bounded below by $[L:K]$ for $L$ ranging
over the finite subextensions of $K$ in $K_\pm$. Our method or proof
generalizes a method of Mazur--Rubin, building upon results of Nekov\'a\v{r},
and applies to abelian varieties of arbitrary dimension, (self-dual twists of)
modular forms of even weight, and (twisted) Hida families.


  Constraint satisfaction problems (CSPs) are about finding values of variables
that satisfy the given constraints. We show that Transformer extended with
recurrence is a viable approach to learning to solve CSPs in an end-to-end
manner, having clear advantages over state-of-the-art methods such as Graph
Neural Networks, SATNet, and some neuro-symbolic models. With the ability of
Transformer to handle visual input, the proposed Recurrent Transformer can
straightforwardly be applied to visual constraint reasoning problems while
successfully addressing the symbol grounding problem. We also show how to
leverage deductive knowledge of discrete constraints in the Transformer's
inductive learning to achieve sample-efficient learning and semi-supervised
learning for CSPs.


  In this paper we study the influence of the threshold effects due to massive
degrees of freedom in the evolution with scale of gauge coupling constants. We
first describe in detail the (standard) mass dependent renormalization
prescription we use. This guides us to introduce and work with effective
couplings, which are finite, process independent, and include complete
threshold effects. We compute the evolution of the effective couplings in both,
the Standard Model and its Minimal Supersymmetric extension, from \mz\ to the
high energy region. We find that the effects from thresholds due to the
standard massive gauge bosons are non--negligible, contrary to what is
generally assumed when using other, less--accurate, descriptions of the
thresholds, as for example in the step--function approximation. Moreover, we
find that thresholds are relevant when studying perturbative SUSY unification,
changing the conclusions reached when using the step--function approach. We
find that threshold effects bring conflict between the known experimental data
at $m_Z$, the naturalness upper bound on the masses of SUSY partners and the
$perturbative$ unification of couplings.


  The intrinsic mechanical strength of single-walled carbon nanotubes (SWNTs)
within the diameter range of 0.3-0.8 nm has been studied based on ab initio
density functional theory calculations. In contrast to predicting "smaller is
stronger and more elastic" in nanomaterials, the strength of the SWNTs is
significantly reduced when decreasing the tube diameter. The results obtained
show that the Young`s modulus E significantly reduced in the ultra-small SWNTs
with the diameter less than 0.4 nm originates from their very large curvature
effect, while it is a constant of about 1.0 TPa, and independent of the
diameter and chiral index for the large tube. We find that the Poisson`s ratio,
ideal strength and ideal strain are dependent on the diameter and chiral index.
Furthermore, the relations between E and ideal strength indicate that
Griffith`s estimate of brittle fracture could break down in the smallest (2, 2)
nanotube, with the breaking strength of 15% of E. Our results provide important
insights into intrinsic mechanical behavior of ultra-small SWNTs under their
curvature effect.


  We study supercritical branching processes under the influence of an i.i.d.
emigration component. We provide conditions, under which the lifetime of the
process is finite respectively has a finite expectation. A new version of the
Kesten-Stigum theorem is obtained and the extinction probability for a large
initial population size is related to the tail behaviour of the emigration.


  57Fe Mossbauer spectroscopy was used to perform a microscopic study on the
extremely pressure and strain sensitive compound, CaFe2As2, with different
degrees of strain introduced by grinding and annealing. At the base
temperature, in the antiferromagnetic/orthorhombic phase, compared to a sharp
sextet Mossbauer spectrum of single crystal CaFe2As2, which is taken as an
un-strained sample, an obviously broadened sextet and an extra doublet were
observed for ground CaFe2As2 powders with different degrees of strain. The
Mossbauer results suggest that the magnetic phase transition of CaFe2As2 can be
inhomogeneously suppressed by the grinding induced strain to such an extent
that the antiferromagnetic order in parts of the grains forming the powdered
sample remain absent all the way down to 4.6 K. However, strain has almost no
effect on the temperature dependent hyperfine magnetic field in the grains with
magnetic order. Additional electronic and asymmetry information was obtained
from the isomer shift and quadrupole splitting. Similar isomer shift values in
the magnetic phase for samples with different degrees of strain, indicate that
the stain does not bring any significant variation of the electronic density at
57Fe nucleus position. The absolute values of quadrupole shift in the magnetic
phase decrease and approach zero with increasing degrees of strain, indicating
that the strain reduces the average lattice asymmetry at Fe atom position.


  Speaker verification, as a biometric authentication mechanism, has been
widely used due to the pervasiveness of voice control on smart devices.
However, the task of "in-the-wild" speaker verification is still challenging,
considering the speech samples may contain lots of identity-unrelated
information, e.g., background noise, reverberation, emotion, etc. Previous
works focus on optimizing the model to improve verification accuracy, without
taking into account the elimination of the impact from the identity-unrelated
information. To solve the above problem, we propose SEEF-ALDR, a novel Speaker
Embedding Enhancement Framework via Adversarial Learning based Disentangled
Representation, to reinforce the performance of existing models on speaker
verification. The key idea is to retrieve as much speaker identity information
as possible from the original speech, thus minimizing the impact of
identity-unrelated information on the speaker verification task by using
adversarial learning. Experimental results demonstrate that the proposed
framework can significantly improve the performance of speaker verification by
20.3% and 23.8% on average over 13 tested baselines on dataset Voxceleb1 and 8
tested baselines on dataset Voxceleb2 respectively, without adjusting the
structure or hyper-parameters of them. Furthermore, the ablation study was
conducted to evaluate the contribution of each module in SEEF-ALDR. Finally,
porting an existing model into the proposed framework is straightforward and
cost-efficient, with very little effort from the model owners due to the
modular design of the framework.


  The field of quantum computing has grown from concept to demonstration
devices over the past 20 years. Universal quantum computing offers efficiency
in approaching problems of scientific and commercial interest, such as
factoring large numbers, searching databases, simulating intractable models
from quantum physics, and optimizing complex cost functions. Here, we present
an 11-qubit fully-connected, programmable quantum computer in a trapped ion
system composed of 13 $^{171}$Yb$^{+}$ ions. We demonstrate average
single-qubit gate fidelities of 99.5$\%$, average two-qubit-gate fidelities of
97.5$\%$, and state preparation and measurement errors of 0.7$\%$. To
illustrate the capabilities of this universal platform and provide a basis for
comparison with similarly-sized devices, we compile the Bernstein-Vazirani (BV)
and Hidden Shift (HS) algorithms into our native gates and execute them on the
hardware with average success rates of 78$\%$ and 35$\%$, respectively. These
algorithms serve as excellent benchmarks for any type of quantum hardware, and
show that our system outperforms all other currently available hardware.


  Transfer learning is focused on the reuse of supervised learning models in a
new context. Prominent applications can be found in robotics, image processing
or web mining. In these fields, the learning scenarios are naturally changing
but often remain related to each other motivating the reuse of existing
supervised models. Current transfer learning models are neither sparse nor
interpretable. Sparsity is very desirable if the methods have to be used in
technically limited environments and interpretability is getting more critical
due to privacy regulations. In this work, we propose two transfer learning
extensions integrated into the sparse and interpretable probabilistic
classification vector machine. They are compared to standard benchmarks in the
field and show their relevance either by sparsity or performance improvements.


  We consider a class of unified models based on the gauge group
$\mathsf{SO(10)}$ which with appropriate choice of Higgs representations
generate in a natural way a pair of light Higgs doublets needed to accomplish
electroweak symmetry breaking. In this class of models higher dimensional
operators of the form matter-matter-Higgs-Higgs in the superpotential after
spontaneous breaking of the GUT symmetry generate contributions to Yukawa
couplings which are comparable to the ones from cubic interactions.
Specifically we consider an $\mathsf{SO(10)}$ model with a sector consisting of
$\mathsf{126+\overline{126} + 210}$ of heavy Higgs which breaks the GUT
symmetry down to the standard model gauge group and a sector consisting of
$2\times \mathsf{10+120}$ of light Higgs fields. In this model we compute the
corrections from the quartic interactions to the Yukawa couplings for the top
and the bottom quarks and for the tau lepton. It is then shown that inclusion
of these corrections to the GUT scale Yukawas allows for consistency of the
top, bottom and tau masses with experiment for low $\tan\beta$ with a value as
low as $\tan\beta$ of 5$-$10. We compute the sparticle spectrum for a set of
benchmarks and find that satisfaction of the relic density is achieved via a
compressed spectrum and coannihilation and three sets of coannihilations
appear: chargino-neutralino, stop-neutralino and stau-neutralino. We
investigate the chargino-neutralino coannihilation in detail for the
possibility of observation of the light chargino at the high luminosity LHC
(HL-LHC) and at the high energy LHC (HE-LHC) which is a possible future 27 TeV
hadron collider. It is shown that all benchmark models but one can be
discovered at HL-LHC and all would be discoverable at HE-LHC. The ones
discoverable at both machines require a much shorter time scale and a lower
integrated luminosity at HE-LHC.


  In 1973, Lemmens and Seidel posed the problem of determining the maximum
number of equiangular lines in $\mathbb{R}^r$ with angle $\arccos(\alpha)$ and
gave a partial answer in the regime $r \leq 1/\alpha^2 - 2$. At the other
extreme where $r$ is at least exponential in $1/\alpha$, recent breakthroughs
have led to an almost complete resolution of this problem. In this paper, we
introduce a new method for obtaining upper bounds which unifies and improves
upon previous approaches, thereby yielding bounds which bridge the gap between
the aforementioned regimes and are best possible either exactly or up to a
small multiplicative constant. Our approach relies on orthogonal projection of
matrices with respect to the Frobenius inner product and as a byproduct, it
yields the first extension of the Alon-Boppana theorem to dense graphs, with
equality for strongly regular graphs corresponding to $\binom{r+1}{2}$
equiangular lines in $\mathbb{R}^r$. Applications of our method in the complex
setting will be discussed as well.


  Let $\delta\in(0,1]$ and $T$ be a $\delta$-Calder\'on-Zygmund operator. Let
$w$ be in the Muckenhoupt class $A_{1+\delta/n}({\mathbb R}^n)$ satisfying
$\int_{{\mathbb R}^n}\frac {w(x)}{1+|x|^n}\,dx<\infty$. When $b\in{\rm
BMO}(\mathbb R^n)$, it is well known that the commutator $[b, T]$ is not
bounded from $H^1(\mathbb R^n)$ to $L^1(\mathbb R^n)$ if $b$ is not a constant
function. In this article, the authors find out a proper subspace
${\mathop\mathcal{BMO}_w({\mathbb R}^n)}$ of $\mathop\mathrm{BMO}(\mathbb R^n)$
such that, if $b\in {\mathop\mathcal{BMO}_w({\mathbb R}^n)}$, then $[b,T]$ is
bounded from the weighted Hardy space $H_w^1(\mathbb R^n)$ to the weighted
Lebesgue space $L_w^1(\mathbb R^n)$. Conversely, if $b\in{\rm BMO}({\mathbb
R}^n)$ and the commutators of the classical Riesz transforms
$\{[b,R_j]\}_{j=1}^n$ are bounded from $H^1_w({\mathbb R}^n)$ into
$L^1_w({\mathbb R}^n)$, then $b\in {\mathop\mathcal{BMO}_w({\mathbb R}^n)}$.


  We present LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes,
The HI Nearby Galaxy Survey) that is aimed at determining what drives star
formation in dwarf galaxies. This is a multi-wavelength survey of 37 Dwarf
Irregular and 4 Blue Compact Dwarf galaxies that is centered around HI-line
data obtained with the National Radio Astronomy Observatory (NRAO) Very Large
Array (VLA). The HI-line data are characterized by high sensitivity (less than
1.1 mJy/beam per channel), high spectral resolution (less than or equal to 2.6
km/s), and high angular resolution (~6 arcseconds. The LITTLE THINGS sample
contains dwarf galaxies that are relatively nearby (less than or equal to 10.3
Mpc; 6 arcseconds is less than or equal to 300 pc), that were known to contain
atomic hydrogen, the fuel for star formation, and that cover a large range in
dwarf galactic properties. We describe our VLA data acquisition, calibration,
and mapping procedures, as well as HI map characteristics, and show channel
maps, moment maps, velocity-flux profiles, and surface gas density profiles. In
addition to the HI data we have GALEX UV and ground-based UBV and Halpha images
for most of the galaxies, and JHK images for some. Spitzer mid-IR images are
available for many of the galaxies as well. These data sets are available
on-line.


  Recently, the BESIII Collaboration reported a resonance $Y(2040)$ with
$M=2034\pm13\pm9$ MeV and $\Gamma=234\pm30\pm25$ MeV in the process of
$e^+e^-\rightarrow\omega\pi^0$. In addition, new measurements with much higher
precision for the $\rho(1900)$ and $\rho(2150)$ states are obtained by the
BESIII and BABAR Collaborations. In this work, we perform a systematic study on
the mass spectrum of the excited $\rho$ resonances using the modified
Godfrey-Isgur model, and the strong decays of $Y(2040)$, $\rho(1900)$, and
$\rho(2150)$ within the $^3P_0$ model.We find that $Y(2040)$, $\rho(1900)$, and
$\rho(2150)$ can be interpreted as the $\rho(2^3D_1)$, $\rho(3^3S_1)$, and
$\rho(4^3S_1)$ states, respectively. Meanwhile, the mass and strong decays of
the $\rho(3^3D_1)$ state are predicted as well, which could be helpful to
search for this state in future.


  Some young supernova remnants exhibit thin filaments of X-ray synchrotron
radiation coinciding with the forward shock due to accelerated electrons
interacting with the local magnetic field. The two main models accounting for
the radial brightness evolution of these filaments differ in their prediction
of the narrowing (or not) of the filaments with increasing photon energy. In
this paper, we report our observation of such a narrowing of the synchrotron
filaments in Cassiopeia A at X-ray energies, and how this finding could help in
understanding the mechanisms at stake in their formation. We used a new blind
source separation method on the 1 Ms Chandra observation of Cassiopeia A, in
order to obtain detailed and unpolluted images of the synchrotron emission in
three energy bands. We then extracted the profiles of several filaments at the
forward shock and the reverse shock to estimate and compare their widths. We
find that there is indeed a narrowing with energy of the synchrotron filaments
both at the forward and at the reverse shocks in Cassiopeia A. The energy
dependency of this narrowing seems stronger at high energy, which is indicative
of a damping effect, confirmed by radio observations.


  For which finite subgroups G of SL(r,C), r \geq 4, are there crepant
desingularizations of the quotient space C^r/G? A complete answer to this
question (also known as "Existence Problem" for such desingularizations) would
classify all those groups for which the high-dimensional versions of McKay
correspondence are valid. In the paper we consider this question in the case of
abelian finite subgroups of SL(r,C) by using techniques from toric and discrete
geometry. We give two necessary existence conditions, involving the Hilbert
basis elements of the cone supporting the junior simplex, and an Upper Bound
Theorem, respectively. Moreover, to the known series of Gorenstein abelian
quotient singularities admitting projective, crepant resolutions (which are
briefly recapitulated) we add a new series of non-c.i. cyclic quotient
singularities having this property.


  Underlying event was originally defined by the CDF collaboration decades ago.
Here we improve the original definition to extend our analysis for events with
multiple-jets. We introduce a definition for surrounding rings/belts and based
on this definition the jet- and surrounding-belt-excluded areas will provide a
good underlying event definition. We inverstigate our definition via the
multiplicity in the defined geometry. In parallel, mean transverse momenta of
these areas also studied in proton-proton collisions at $\sqrt{s}=7$ TeV LHC
energy.


  We consider relativistic phase space constructed by the twist procedure from
the translation sector of the standard, nondeforned Poincare algebra. Using the
concept of cross product algebra we derive two kinds of phase space with
noncommuting configuration space. The generalized uncertainty relations are
formulated.


  We introduce the general formulation of a renormalization method suitable to
study the critical properties of non-equilibrium systems with steady-states:
the Dynamically Driven Renormalization Group. We renormalize the time evolution
operator by computing the rescaled time transition rate between coarse grained
states. The obtained renormalization equations are coupled to a stationarity
condition which provides the approximate non-equilibrium statistical weights of
steady-state configurations to be used in the calculations. In this way we are
able to write recursion relations for the parameters evolution under scale
change, from which we can extract numerical values for the critical exponents.
This general framework allows the systematic analysis of several models showing
self-organized criticality in terms of usual concepts of phase transitions and
critical phenomena.


  We show that expander graphs must have Gromov-hyperbolicity at least
proportional to their diameter, with a constant of proportionality depending
only on the expansion constant and maximal degree. In other words, expanders
contain geodesic triangles which are $\Omega(\mathop{\rm diam} \Gamma)$-thick.


  Superconducting cavities can operate analogously to Weber bar detectors of
gravitational waves, converting mechanical to electromagnetic energy. The
significantly reduced electromagnetic noise results in increased sensitivity to
high-frequency signals well outside the bandwidth of the lowest mechanical
resonance. In this work, we revisit such signals of gravitational waves and
demonstrate that a setup similar to the existing "MAGO" prototype, operating in
a scanning or broadband manner, could have sensitivity to strains of $\sim
10^{-22} - 10^{-18}$ for frequencies of $\sim 10 \ \text{kHz} - 1 \
\text{GHz}$.


  Performance analyses based on videos are commonly used by coaches of athletes
in various sports disciplines. In individual sports, these analyses mainly
comprise the body posture. This paper focuses on the disciplines of triple,
high, and long jump, which require fine-grained locations of the athlete's
body. Typical human pose estimation datasets provide only a very limited set of
keypoints, which is not sufficient in this case. Therefore, we propose a method
to detect arbitrary keypoints on the whole body of the athlete by leveraging
the limited set of annotated keypoints and auto-generated segmentation masks of
body parts. Evaluations show that our model is capable of detecting keypoints
on the head, torso, hands, feet, arms, and legs, including also bent elbows and
knees. We analyze and compare different techniques to encode desired keypoints
as the model's input and their embedding for the Transformer backbone.


  The measure hypothesis is a quantitative strengthening of the P != NP
conjecture which asserts that NP is a nonnegligible subset of EXP. Cai,
Sivakumar, and Strauss (1997) showed that the analogue of this hypothesis in P
is false. In particular, they showed that NTIME[n^{1/11}] has measure 0 in P.
We improve on their result to show that the class of all languages decidable in
nondeterministic sublinear time has measure 0 in P. Our result is based on DNF
width and holds for all four major notions of measure on P.


  This proceeding broadly overviews the current landscape of heavy exotic
spectroscopy. Such work includes the composition of certain X, Y , and Z
states, and proceeds to discuss tetraquarks made exclusively of four quarks.


  Currently known topological insulators (TIs) are limited to narrow gap
compounds incorporating heavy elements, thus severely limiting the material
pool available for such applications. We show via first-principle calculations
how a heterovalent superlattice made of common semiconductor building blocks
can transform its non-TI components into a topological nanostructure,
illustrated by III-V/II-VI superlattice InSb/CdTe. The heterovalent nature of
such interfaces sets up, in the absence of interfacial atomic exchange, a
natural internal electric field that along with the quantum confinement leads
to band inversion, transforming these semiconductors into a topological phase
while also forming a giant Rashba spin splitting. We reveal the relationship
between the interfacial stability and the topological transition, finding a
window of opportunity where both conditions can be optimized. Once a critical
InSb layer thickness above ~ 1.5 nm is reached, both [111] and [100]
superlattices have a relative energy of 5-14 meV/A2 higher than that of the
atomically exchanged interface and an excitation gap up to ~150 meV, affording
room-temperature quantum spin Hall effect in semiconductor superlattices. The
understanding gained from this study could significantly broaden the current,
rather restricted repertoire of functionalities available from individual
compounds by creating next-generation super-structured functional materials.


  The emotional response of users induced by VR scenarios has become a topic of
interest, however, whether changing the size of objects in VR scenes induces
different levels of anxiety remains a question to be studied. In this study, we
conducted an experiment to initially reveal how the size of a large object in a
VR environment affects changes in participants' (N = 38) anxiety level and
heart rate. To holistically quantify the size of large objects in the VR visual
field, we used the omnidirectional field of view occupancy (OFVO) criterion for
the first time to represent the dimension of the object in the participant's
entire field of view. The results showed that the participants' heartbeat and
anxiety while viewing the large objects were positively and significantly
correlated to OFVO. These study reveals that the increase of object size in VR
environments is accompanied by a higher degree of user's anxiety.


  The greedy tree $\mathcal{G}(D)$ and the $\mathcal{M}$-tree $\mathcal{M}(D)$
are known to be extremal among trees with degree sequence $D$ with respect to
various graph invariants. This paper provides a general theorem that covers a
large family of invariants for which $\mathcal{G}(D)$ or $\mathcal{M}(D)$ is
extremal. Many known results, for example on the Wiener index, the number of
subtrees, the number of independent subsets and the number of matchings follow
as corollaries, as do some new results on invariants such as the number of
rooted spanning forests, the incidence energy and the solvability. We also
extend our results on trees with fixed degree sequence $D$ to the set of trees
whose degree sequence is majorised by a given sequence $D$, which also has a
number of applications.


  Cryogenic rejuvenation in metallic glasses reported in Ketov et al 's
experiment (Nature(2015)524,200) has attracted much attention, both in
experiments and numerical studies.
  The atomic mechanism of rejuvenation has been conjectured to be related to
the heterogeneity of the glassy state, but the quantitative evidence is still
elusive.
  Here we use molecular dynamics simulations of a model metallic glass to
investigate the heterogeneity in the local thermal expansion. We then combine
the resulting spatial distribution of thermal expansion with a continuum
mechanics calculation to infer the internal stresses caused by a thermal cycle.
  Comparing the internal stress with the local yield stress, we prove that the
heterogeneity in thermomechanical response has the potential to trigger local
shear transformations, and therefore to induce rejuvenation during a cryogenic
thermal cycling.


  A multi-fidelity surrogate model for highly nonlinear multiscale problems is
proposed. It is based on the introduction of two different surrogate models and
an adaptive on-the-fly switching. The two concurrent surrogates are built
incrementally starting from a moderate set of evaluations of the full order
model. Therefore, a reduced order model (ROM) is generated. Using a hybrid
ROM-preconditioned FE solver, additional effective stress-strain data is
simulated while the number of samples is kept to a moderate level by using a
dedicated and physics-guided sampling technique. Machine learning (ML) is
subsequently used to build the second surrogate by means of artificial neural
networks (ANN). Different ANN architectures are explored and the features used
as inputs of the ANN are fine tuned in order to improve the overall quality of
the ML model. Additional ANN surrogates for the stress errors are generated.
Therefore, conservative design guidelines for error surrogates are presented by
adapting the loss functions of the ANN training in pure regression or pure
classification settings. The error surrogates can be used as quality indicators
in order to adaptively select the appropriate -- i.e. efficient yet accurate --
surrogate. Two strategies for the on-the-fly switching are investigated and a
practicable and robust algorithm is proposed that eliminates relevant technical
difficulties attributed to model switching. The provided algorithms and ANN
design guidelines can easily be adopted for different problem settings and,
thereby, they enable generalization of the used machine learning techniques for
a wide range of applications. The resulting hybrid surrogate is employed in
challenging multilevel FE simulations for a three-phase composite with
pseudo-plastic micro-constituents. Numerical examples highlight the performance
of the proposed approach.


  The strong confinement of semiconductor excitons in a quantum dot gives rise
to atom-like behavior. The full benefit of such a structure is best observed in
resonant excitation where the excited state can be deterministically populated
and coherently manipulated. Due to large refractive index and device geometry
it remains challenging to observe resonantly excited emission that is free from
laser scattering in III/V self-assembled quantum dots. Here we exploit the
biexciton binding energy to create an extremely clean single photon source via
two-photon resonant excitation of an InAs/GaAs quantum dot. We observe complete
suppression of the excitation laser and multi-photon emissions. Additionally,
we perform full coherent control of the ground-biexciton state qubit and
observe an extended coherence time using an all-optical echo technique. The
deterministic coherent photon pair creation makes this system suitable for the
generation of time-bin entanglement and experiments on the interaction of
photons from dissimilar sources.


  We formulate an effective theory of structure formation (ETHOS) that enables
cosmological structure formation to be computed in almost any microphysical
model of dark matter physics. This framework maps the detailed microphysical
theories of particle dark matter interactions into the physical effective
parameters that shape the linear matter power spectrum and the self-interaction
transfer cross section of non-relativistic dark matter. These are the input to
structure formation simulations, which follow the evolution of the cosmological
and galactic dark matter distributions. Models with similar effective
parameters in ETHOS but with different dark particle physics would nevertheless
result in similar dark matter distributions. We present a general method to map
an ultraviolet complete or effective field theory of low energy dark matter
physics into parameters that affect the linear matter power spectrum and carry
out this mapping for several representative particle models. We further propose
a simple but useful choice for characterizing the dark matter self-interaction
transfer cross section that parametrizes self-scattering in structure formation
simulations. Taken together, these effective parameters in ETHOS allow the
classification of dark matter theories according to their structure formation
properties rather than their intrinsic particle properties, paving the way for
future simulations to span the space of viable dark matter physics relevant for
structure formation.


  Recent experimental data on the radiative decays B -> V gamma, where V is a
light vector meson, find small isospin violation in B -> K^* gamma while
isospin asymmetries in B -> rho gamma are of order 20%, with large
uncertainties. Using Soft-Collinear Effective Theory, we calculate isospin
asymmetries in these radiative B decays up to O(1/m_b), also including O(v
alpha_s) contributions from nonperturbative charming penguins (NPCP). In the
absence of NPCP contributions, the theoretical predictions for the asymmetries
are a few percent or less. Including the NPCP can significantly increase the
isospin asymmetries for both B -> V gamma modes. We also consider the effect of
the NPCP on the branching ratio and CP asymmetries in B^\pm -> V^\pm gamma.


  We show that the position-momentum duality offers a transparent
interpretation of the band geometry at the topological band crossings. Under
this duality, the band geometry with Berry connection is dual to the
free-electron motion under gauge field. This identifies the trace of quantum
metric as the dual energy in momentum space. The band crossings with Berry
defects thus induce the dual energy quantization in the trace of quantum
metric. For the $\mathbb Z$ nodal-point and nodal-surface semimetals in three
dimensions, the dual Landau level quantization occurs owing to the Berry
charges. Meanwhile, the two-dimensional (2D) Dirac points exhibit the Berry
vortices, leading to the quantized dual axial rotational energies. Such a
quantization naturally generalizes to the three-dimensional (3D) nodal-loop
semimetals, where the nodal loops host the Berry vortex lines. The $\mathbb
Z_2$ monopoles bring about additional dual axial rotational energies, which
originate from the links with additional nodal lines. Nontrivial band geometry
generically induces finite spread in the Wannier functions. While the spread
manifest quantized lower bounds from the Berry charges, logarithmic divergences
occur from the Berry vortices. The band geometry at the band crossings may be
probed experimentally by a periodic-drive measurement.


  We analytically obtain the dispersion relations for transverse-electric (TE)
and transverse-magnetic (TM) surface plasmon-polaritons in a nonlinear
two-dimensional (2D) conducting material lying between two Kerr-type dielectric
media. To this end, we use Maxwell's equations within the quasi-electrostatic,
weakly dissipative regime. We show that the wavelength and propagation distance
of surface plasmons decrease due to the nonlinearity of the surrounding
dielectric. In contrast, the effect of the nonlinearity of the 2D material
depends on the signs of the real and imaginary parts of the third-order
conductivity. Notably, the dispersion relations obtained by naively replacing
the permittivity of the dielectric medium by its nonlinear counterpart in the
respective dispersion relations of the linear regime are not accurate. We apply
our analysis to the case of doped graphene and make predictions for the
TM-polarized surface plasmon wavelength and propagation distance.


  Dense scene reconstruction for photo-realistic view synthesis has various
applications, such as VR/AR, autonomous vehicles. However, most existing
methods have difficulties in large-scale scenes due to three core challenges:
\textit{(a) inaccurate depth input.} Accurate depth input is impossible to get
in real-world large-scale scenes. \textit{(b) inaccurate pose estimation.} Most
existing approaches rely on accurate pre-estimated camera poses. \textit{(c)
insufficient scene representation capability.} A single global radiance field
lacks the capacity to effectively scale to large-scale scenes. To this end, we
propose an incremental joint learning framework, which can achieve accurate
depth, pose estimation, and large-scale scene reconstruction. A vision
transformer-based network is adopted as the backbone to enhance performance in
scale information estimation. For pose estimation, a feature-metric bundle
adjustment (FBA) method is designed for accurate and robust camera tracking in
large-scale scenes. In terms of implicit scene representation, we propose an
incremental scene representation method to construct the entire large-scale
scene as multiple local radiance fields to enhance the scalability of 3D scene
representation. Extended experiments have been conducted to demonstrate the
effectiveness and accuracy of our method in depth estimation, pose estimation,
and large-scale scene reconstruction.


  We adopt an artificial counterfactual approach to assess the impact of
lockdowns on the short-run evolution of the number of cases and deaths in some
US states. To do so, we explore the different timing in which US states adopted
lockdown policies, and divide them among treated and control groups. For each
treated state, we construct an artificial counterfactual. On average, and in
the very short-run, the counterfactual accumulated number of cases would be two
times larger if lockdown policies were not implemented.


  Automated design of analog and radio-frequency circuits using supervised or
reinforcement learning from simulation data has recently been studied as an
alternative to manual expert design. It is straightforward for a design agent
to learn an inverse function from desired performance metrics to circuit
parameters. However, it is more common for a user to have threshold performance
criteria rather than an exact target vector of feasible performance measures.
In this work, we propose a method for generating from simulation data a dataset
on which a system can be trained via supervised learning to design circuits to
meet threshold specifications. We moreover perform the to-date most extensive
evaluation of automated analog circuit design, including experimenting in a
significantly more diverse set of circuits than in prior work, covering linear,
nonlinear, and autonomous circuit configurations, and show that our method
consistently reaches success rate better than 90% at 5% error margin, while
also improving data efficiency by upward of an order of magnitude. A demo of
this system is available at circuits.streamlit.app


  It is well known that Space-Time Block Codes (STBCs) obtained from Orthogonal
Designs (ODs) are single-symbol-decodable (SSD) and from Quasi-Orthogonal
Designs (QODs) are double-symbol decodable. However, there are SSD codes that
are not obtainable from ODs and DSD codes that are not obtainable from QODs. In
this paper a method of constructing $g$-symbol decodable ($g$-SD) STBCs using
representations of Clifford algebras are presented which when specialized to
$g=1,2$ gives SSD and DSD codes respectively. For the number of transmit
antennas $2^a$ the rate (in complex symbols per channel use) of the $g$-SD
codes presented in this paper is $\frac{a+1-g}{2^{a-g}}$. The maximum rate of
the DSD STBCs from QODs reported in the literature is $\frac{a}{2^{a-1}}$ which
is smaller than the rate $\frac{a-1}{2^{a-2}}$ of the DSD codes of this paper,
for $2^a$ transmit antennas. In particular, the reported DSD codes for 8 and 16
transmit antennas offer rates 1 and 3/4 respectively whereas the known STBCs
from QODs offer only 3/4 and 1/2 respectively. The construction of this paper
is applicable for any number of transmit antennas.


  For the voter model, we study the effect of a memory-dependent transition
rate. We assume that the transition of a spin into the opposite state decreases
with the time it has been in its current state. Counter-intuitively, we find
that the time to reach a macroscopically ordered state can be accelerated by
slowing-down the microscopic dynamics in this way. This holds for different
network topologies, including fully-connected ones. We find that the ordering
dynamics is governed by two competing processes which either stabilize the
majority or the minority state. If the first one dominates, it accelerates the
ordering of the system. The conclusions of this Letter are not restricted to
the voter model, but remain valid to many other spin systems as well.


  We classify the Ricci flat Lorentzian $n$-manifolds satisfying three
particular conditions, encoding and combining some crucial features of the Kerr
metrics and the Robinson-Trautman optical structures. We prove that if $n > 4$,
there is no Lorentzian manifold satisfying the considered conditions, while for
$n = 4$ there are two large classes of such manifolds. Each class consists of
manifolds fibering over open Riemann surfaces, equipped with a metric of
constant Gaussian curvature $\kappa = 1$ or $\kappa = -1$. The first class
properly includes a three parameter family of metrics admitting real analytic
extensions to $(\mathbb R^3 \setminus\{0\}) \times \mathbb R = (S^2 \times
\mathbb R_+) \times \mathbb R$ (all others develop singularities) and all such
extensions are isometric to the well-known Kerr metrics. The three parameters
correspond to the three space-like components of the angular momentum of the
gravitational field. The second class contains a subclass of metrics defined on
$\big(\mathbb D\times \mathbb R_+\big)\times \mathbb R$, where $\mathbb D$ is
the Lobachevsky Poincar\'e disc. This subclass is in bijection with the
holomorphic functions on $\mathbb D$ satisfying an appropriate open condition.
These and other results are obtained as consequences of a very simple method of
generating a number of explicit examples of Ricci flat Lorentzian manifolds.


  We report on the fabrication and characterization of vertical spin-valve
structures using a thick epitaxial MgO barrier as spacer layer and a
graphene-passivated Ni film as bottom ferromagnetic electrode. The devices show
robust and scalable tunnel magnetoresistance, with several changes of sign upon
varying the applied bias voltage. These findings are explained by a model of
phonon-assisted transport mechanisms that relies on the peculiarity of the band
structure and spin density of states at the hybrid graphene|Ni interface.


  Discriminative correlation filters show excellent performance in object
tracking. However, in complex scenes, the apparent characteristics of the
tracked target are variable, which makes it easy to pollute the model and cause
the model drift. In this paper, considering that the secondary peak has a
greater impact on the model update, we propose a method for detecting the
primary and secondary peaks of the response map. Secondly, a novel confidence
function which uses the adaptive update discriminant mechanism is proposed,
which yield good robustness. Thirdly, we propose a robust tracker with
correlation filters, which uses hand-crafted features and can improve model
drift in complex scenes. Finally, in order to cope with the current trackers'
multi-feature response merge, we propose a simple exponential adaptive merge
approach. Extensive experiments are performed on OTB2013, OTB100 and TC128
datasets. Our approach performs superiorly against several state-of-the-art
trackers while runs at speed in real time.


  In this work, we analyze in detail the occurrence of divergences in the
irreducible vertex functions for one of the fundamental models of many-body
physics: the Anderson impurity model (AIM). These divergences -- a surprising
hallmark of the breakdown of many-electron perturbation theory -- have been
recently observed in several contexts, including the dynamical mean-field
solution of the Hubbard model. The numerical calculations for the AIM presented
in this work, as well as their comparison with the corresponding results for
the Hubbard model, allow us to clarify several open questions about the origin
and the properties of vertex divergences in a particularly interesting context,
the correlated metallic regime at low-temperatures. Specifically, our analysis
(i) rules out explicitly the transition to a Mott insulating phase, but not the
more general suppression of charge fluctuations (proposed in [Phys.\,Rev.\,B
{\bf 93},\,245102\,(2016)]), as a necessary condition for the occurrence of
vertex divergences, (ii) clarifies their relation with the underlying Kondo
physics, and, eventually, (iii) individuates which divergences might also
appear on the real frequency axis in the limit of zero temperature, through the
discovered scaling properties of the singular eigenvectors.


  A key problem in the field of quantum criticality is to understand the nature
of quantum phase transitions in systems of interacting itinerant fermions,
motivated by experiments on a variety of strongly correlated materials. Much
attention has been paid in recent years to two-dimensional (2D) materials in
which itinerant fermions acquire a pseudo-relativistic Dirac dispersion, such
as graphene, topological insulator surfaces, and certain spin liquids. This
article reviews the phenomenology and theoretical description of quantum phase
transitions in systems of 2D Dirac fermions.


  We construct unique martingale solutions to the damped stochastic wave
equation $$ \mu \frac{\partial^2u}{\partial t^2}(t,x)=\Delta
u(t,x)-\frac{\partial u}{\partial
t}(t,x)+b(t,x,u(t,x))+\sigma(t,x,u(t,x))\frac{dW_t}{dt},$$
  where $\Delta$ is the Laplacian on $[0,1]$ with Dirichlet boundary condition,
$W$ is space-time white noise, $\sigma$ is $\frac{3}{4}+\epsilon$ -H\"older
continuous in $u$ and uniformly non-degenerate, and $b$ has linear growth. The
same construction holds for the stochastic wave equation without damping term.
More generally, the construction holds for SPDEs defined on separable Hilbert
spaces with a densely defined operator $A$, and the assumed H\"older regularity
on the noise coefficient depends on the eigenvalues of $A$ in a quantitative
way. We further show the validity of the Smoluchowski-Kramers approximation:
assume $b$ is H\"older continuous in $u$, then as $\mu$ tends to $0$ the
solution to the damped stochastic wave equation converges in distribution, on
the space of continuous paths, to the solution of the corresponding stochastic
heat equation. The latter result is new even in the case of additive noise.


  Gas stopping is becoming the method of choice for converting beams of rare
isotopes obtained via projectile fragmentation and in-flight separation into
low-energy beams. These beams allow ISOL-type experiments, such as mass
measurements with traps or laser spectroscopy, to be performed with projectile
fragmentation products. Current gas stopper systems for high-energy beams are
based on linear gas cells filled with 0.1-1 bar of helium. While already used
successfully for experiments, it was found that space charge effects induced by
the ionization of the helium atoms during the stopping process pose a limit on
the maximum beam rate that can be used. Furthermore, the extraction time of
stopped ions from these devices can exceed 100 ms causing substantial decay
losses for very short-lived isotopes. To avoid these limitations, a new type of
gas stopper is being developed at the NSCL/MSU. The new system is based on a
cyclotron-type magnet with a stopping chamber filled with Helium buffer gas at
low pressure. RF-guiding techniques are used to extract the ions. The space
charge effects are considerably reduced by the large volume and due to a
separation between the stopping region and the region of highest ionization.
Cyclotron gas stopper systems of different sizes and with different magnetic
field strengths and field shapes are presently investigated.


  We study the electron transport properties through a supported organic
molecule styrene (C8H8) on an ideal silicon surface Si[111] and probed by a
STM-tip. The I-V characteristics and the differential conductance of the
molecule are calculated using a self consistent approach based on non
equilibrium Green's functions. Two different adsorption configurations for the
molecule on the surface were considered which corresponds to a global and a
local minimum of the total energy. In both cases we find a negative
differential resistance (NDR) in a given interval of bias voltages. This effect
is controlled by the states available close to the Fermi level of the surface
and can be manipulated by properly doping the substrate. We also analyze the
influence of the tip-shape on the I-V characteristics.


  We investigate excitation dynamics in the system of a quantum dipole emitter
(QDE) coupled to a located nearby metal nanoparticle (MNP), which exhibits a
dipolar localized surface plasmon (LSP) resonance at the frequency of the QDE
radiative transition, in the presence of a strong external resonant
electromagnetic field. Considering the QDE-field interactions in the regime of
strong QDE-field coupling, we show that the feedback provided by the MNP on the
QDE (due to the LSP excitation with the field generated by the dipole moment of
the QDE transition) influences significantly the coherent process of Rabi
oscillations, resulting in the occurrence of additional satellite frequencies
in the radiation spectrum scattered by the QDE-MNP configuration. The relative
ratio of high harmonics depends strongly on the QDE-MNP separation, an
important characteristic feature that can be used for observing this effect and
exploited, for example, for controlling distances at nanoscale.


  For a $p$-adic local field $K$ with perfect residue field, L. Herr
constructed a complex which computes the Galois cohomology of a $p$-torsion
representation of the absolute Galois group of $K$ by using the theory of
$(\Phi,\Gamma)$-modules. We shall generalize his work to the imperfect residue
field (the residue field has a finite $p$-basis) case.


  We propose an energy-stable parametric finite element method (ES-PFEM) to
discretize the motion of a closed curve under surface diffusion with an
anisotropic surface energy $\gamma(\theta)$ -- anisotropic surface diffusion --
in two dimensions, while $\theta$ is the angle between the outward unit normal
vector and the vertical axis. By introducing a positive definite surface energy
(density) matrix $G(\theta)$, we present a new and simple variational
formulation for the anisotropic surface diffusion and prove that it satisfies
area/mass conservation and energy dissipation. The variational problem is
discretized in space by the parametric finite element method and area/mass
conservation and energy dissipation are established for the
semi-discretization. Then the problem is further discretized in time by a
(semi-implicit) backward Euler method so that only a linear system is to be
solved at each time step for the full-discretization and thus it is efficient.
We establish well-posedness of the full-discretization and identify some simple
conditions on $\gamma(\theta)$ such that the full-discretization keeps energy
dissipation and thus it is unconditionally energy-stable. Finally the ES-PFEM
is applied to simulate solid-state dewetting of thin films with anisotropic
surface energies, i.e. the motion of an open curve under anisotropic surface
diffusion with proper boundary conditions at the two triple points moving along
the horizontal substrate. Numerical results are reported to demonstrate the
efficiency and accuracy as well as energy dissipation of the proposed ES-PFEM.


  We present a theory of spin, electronic and transport properties of a
few-electron lateral triangular triple quantum dot molecule in a magnetic
field. Our theory is based on a generalization of a Hubbard model and the
Linear Combination of Harmonic Orbitals combined with Configuration Interaction
method (LCHO-CI) for arbitrary magnetic fields. The few-particle spectra
obtained as a function of the magnetic field exhibit Aharonov-Bohm
oscillations. As a result, by changing the magnetic field it is possible to
engineer the degeneracies of single-particle levels, and thus control the total
spin of the many-electron system. For the triple dot with two and four
electrons we find oscillations of total spin due to the singlet-triplet
transitions occurring periodically in the magnetic field. In the three-electron
system we find a transition from a magnetically frustrated to the
spin-polarized state. We discuss the impact of these phase transitions on the
addition spectrum and the spin blockade of the lateral triple quantum dot
molecule.


  We propose a probabilistic model discovery method for identifying ordinary
differential equations (ODEs) governing the dynamics of observed multivariate
data. Our method is based on the sparse identification of nonlinear dynamics
(SINDy) framework, in which target ODE models are expressed as a sparse linear
combinations of pre-specified candidate functions. Promoting parsimony through
sparsity in SINDy leads to interpretable models that generalize to unknown
data. Instead of targeting point estimates of the SINDy (linear combination)
coefficients, in this work we estimate these coefficients via sparse Bayesian
inference. The resulting method, uncertainty quantification SINDy (UQ-SINDy),
quantifies not only the uncertainty in the values of the SINDy coefficients due
to observation errors and limited data, but also the probability of inclusion
of each candidate function in the linear combination. UQ-SINDy promotes
robustness against observation noise and limited data, interpretability (in
terms of model selection and inclusion probabilities), and generalization
capacity for out-of-sample forecast. Sparse inference for UQ-SINDy employs
Markov Chain Monte Carlo, and we explore two sparsifying priors: the
spike-and-slab prior, and the regularized horseshoe prior. We apply UQ-SINDy to
synthetic nonlinear data sets from a Lotka-Volterra model and a nonlinear
oscillator, and to a real-world data set of lynx and hare populations. We find
that UQ-SINDy is able to discover accurate and meaningful models even in the
presence of noise and limited data samples.


  Pre-trained Language Models (PLMs) have achieved great success on Machine
Reading Comprehension (MRC) over the past few years. Although the general
language representation learned from large-scale corpora does benefit MRC, the
poor support in evidence extraction which requires reasoning across multiple
sentences hinders PLMs from further advancing MRC. To bridge the gap between
general PLMs and MRC, we present REPT, a REtrieval-based Pre-Training approach.
In particular, we introduce two self-supervised tasks to strengthen evidence
extraction during pre-training, which is further inherited by downstream MRC
tasks through the consistent retrieval operation and model architecture. To
evaluate our proposed method, we conduct extensive experiments on five MRC
datasets that require collecting evidence from and reasoning across multiple
sentences. Experimental results demonstrate the effectiveness of our
pre-training approach. Moreover, further analysis shows that our approach is
able to enhance the capacity of evidence extraction without explicit
supervision.


  We present a search for anisotropic cosmic birefringence in 500 deg$^2$ of
southern sky observed at 150 GHz with the SPTpol camera on the South Pole
Telescope. We reconstruct a map of cosmic polarization rotation anisotropies
using higher-order correlations between the observed cosmic microwave
background (CMB) $E$ and $B$ fields. We then measure the angular power spectrum
of this map, which is found to be consistent with zero. The non-detection is
translated into an upper limit on the amplitude of the scale-invariant cosmic
rotation power spectrum, $L(L+1)C_L^{\alpha\alpha}/2\pi < 0.10 \times 10^{-4}$
rad$^2$ (0.033 deg$^2$, 95% C.L.). This upper limit can be used to place
constraints on the strength of primordial magnetic fields, $B_{1 \rm Mpc} < 17
{\rm nG} $ (95% C.L.), and on the coupling constant of the Chern-Simons
electromagnetic term $g_{a\gamma} < 4.0 \times 10^{-2}/H_I $ (95% C.L.), where
$H_I$ is the inflationary Hubble scale. For the first time, we also
cross-correlate the CMB temperature fluctuations with the reconstructed
rotation angle map, a signal expected to be non-vanishing in certain
theoretical scenarios, and find no detectable signal. We perform a suite of
systematics and consistency checks and find no evidence for contamination.


  In this paper we completely describe the winning and losing conditions
different from the only ``trivial'' conditions known before. In other words, we
solve the open question of finding a complete nontrivial Schmidt diagram. In
addition, we give the new bounds for two family of sets: one related to
frequencies of digits in base-$2$ expansions, and one connected to the set of
the badly approximable numbers.


  We calculate the rates and lepton (l) invariant mass distributions for decays
of the form 0^{-+}->l^+l^-\gamma, which are important radiative corrections to
the purely leptonic decays 0^{-+}->l^+l^-. Our approach uses the loop diagrams
which arise by including the two photon intermediate state and we retain the
imaginary parts of the loops - a radiative extension of the `unitarity bound'
for the process. These results are compared which those obtained using a model
in which the meson couples directly to the leptons.


  Parkinson's disease (PD) is a common neurodegenerative disorder with a
prevalence rate estimated to 2.0% for people aged over 65 years. Cardinal motor
symptoms of PD such as rigidity and bradykinesia affect the muscles involved in
the handwriting process resulting in handwriting abnormalities called PD
dysgraphia. Nowadays, online handwritten signal (signal with temporal
information) acquired by the digitizing tablets is the most advanced approach
of graphomotor difficulties analysis. Although the basic kinematic features
were proved to effectively quantify the symptoms of PD dysgraphia, a recent
research identified that the theory of fractional calculus can be used to
improve the graphomotor difficulties analysis. Therefore, in this study, we
follow up on our previous research, and we aim to explore the utilization of
various approaches of fractional order derivative (FD) in the analysis of PD
dysgraphia. For this purpose, we used the repetitive loops task from the
Parkinson's disease handwriting database (PaHaW). Handwritten signals were
parametrized by the kinematic features employing three FD approximations:
Gr\"unwald-Letnikov's, Riemann-Liouville's, and Caputo's. Results of the
correlation analysis revealed a significant relationship between the clinical
state and the handwriting features based on the velocity. The extracted
features by Caputo's FD approximation outperformed the rest of the analyzed FD
approaches. This was also confirmed by the results of the classification
analysis, where the best model trained by Caputo's handwriting features
resulted in a balanced accuracy of 79.73% with a sensitivity of 83.78% and a
specificity of 75.68%.


  Optimal (v, 4, 2, 1) optical orthogonal codes (OOC) with $v<=75$ and $v\ne
71$ are classified up to equivalence. One $(v, 4, 2, 1)$ OOC is presented for
all $v\le 181$, for which an optimal OOC exists.


  We study the electronic structure of halogen-bridged binuclear metal (MMX)
complexes with a two-band Peierls-Hubbard model. Based on a symmetry argument,
various density-wave states are derived and characterized. The ground-state
phase diagram is drawn within the Hartree-Fock approximation, while the thermal
behavior is investigated using a quantum Monte Carlo method. All the
calculations conclude that a typical MMX compound Pt_2(CH_3CS_2)_4I should
indeed be regarded as a d-p-hybridized two-band material, where the oxidation
of the halogen ions must be observed even in the ground state, whereas another
MMX family (NH_4)_4[Pt_2(P_2O_5H_2)_4X] may be treated as single-band
materials.


  We propose a new method to prove Anderson localization for quasiperiodic
Schr\"odinger operators and apply it to the quasiperiodic model considered by
Sinai and Fr\"ohlich-Spencer-Wittwer. More concretely, we prove Anderson
localization for even $C^2$ cosine type quasiperiodic Schr\"odinger operators
with large coupling constants, Diophantine frequencies and Diophantine phases.


  We present z'-band secondary eclipse photometry of the highly irradiated hot
Jupiter WASP-12b using ULTRACAM on the 4.2m William Herschel Telescope. We
measure a decrease in flux of \delta = 0.130+/-0.013% during the passage of the
planet behind the star, which is significantly deeper than the previous
measurement at this wavelength (0.082+/-0.015%, L\'opez-Morales et al. 2010).
Our secondary eclipse is best fit with a mid-eclipse phase, \phi, that is
compatible with a circular orbit \phi = 0.501+/-0.002, in agreement with
previous results (Croll et al. 2011). In combination with existing data, our
eclipse depth measurement allows us to constrain the characteristics of the
planet's atmosphere, which is consistent with a carbon-rich model, with no
evidence for a strong thermal inversion. If the difference in eclipse depth
reported here compared to that of L\'opez-Morales et al. (2010) is of physical
origin, as opposed to due to systematics, it may be caused by temporal
variability in the flux, due to atmospheric dynamics.


  We present quantitative ultrafast interferometric pump-probe microscopy
capable of tracking of photoexcitations with sub 10 nm spatial precision in
three dimensions with 15 fs temporal resolution, through retrieval of the full
transient photoinduced complex refractive index. We use this methodology to
study the spatiotemporal dynamics of the quantum coherent photophysical process
of ultrafast singlet exciton fission. Measurements on microcrystalline
pentacene films grown on glass (SiO$_2$) and boron nitride (hBN) reveal a 25
nm, 70 fs expansion of the joint-density-of-states along the crystal a,c-axes
accompanied by a 6 nm, 115 fs change in the exciton density along the crystal
b-axis. We propose that photogenerated singlet excitons expand along the
direction of maximal orbital $\pi$-overlap in the crystal a,c-plane to form
correlated triplet pairs, which subsequently electronically decouples into free
triplets along the crystal b-axis due to molecular sliding motion of
neighbouring pentacene molecules. This methodology opens a new route for the
study of three dimensional transport on ultrafast timescales.


  We present a free open source package for high performance simulation and
numerical investigation of boson samplers and, more generally, multi-photon
interferometry. Our package is written in Julia, allowing C-like performance
with easy notations and fast, high-level coding. Underlying building blocks can
easily be modified without complicated low-level language modifications. We
present a great variety of routines for tasks related to boson sampling, such
as statistical tools, optimization methods, classical samplers and validation
tools.


  We study caustics in classical and quantum mechanics for systems with
quadratic Lagrangians. We derive a closed form of the transition amplitude on
caustics and discuss their physical implications in the Gaussian slit
(gedanken-)experiment. Application to the quantum mechanical rotor casts doubt
on the validilty of Jevicki's correspondence hypothesis which states that in
quantum mechanics, stationary points(instantons) arise as simple poles.


  This paper presents the measurement of the relative width difference $\Delta
\Gamma_d / \Gamma_d$ of the $B^0$-$\bar B^0$ system using the data collected by
the ATLAS experiment at the LHC in $p p$ collisions at $\sqrt{s} = 7$ TeV and
$\sqrt{s} = 8$ TeV and corresponding to an integrated luminosity of 25.2
fb$^{-1}$. The value of $\Delta \Gamma_d / \Gamma_d$ is obtained by comparing
the decay-time distributions of $B^0 \to J/\psi K_S$ and $B^0 \to J/\psi
K^{*0}(892)$ decays. The result is $\Delta \Gamma_d / \Gamma_d = (-0.1 \pm
1.1~\mbox{(stat.)} \pm 0.9~\mbox{(syst.)}) \times 10^{-2}$. Currently, this is
the most precise single measurement of $\Delta \Gamma_d / \Gamma_d$. It agrees
with the Standard Model prediction and the measurements by other experiments.


  In this paper, we propose a novel feature weighting method to address the
limitation of existing feature processing methods for tabular data. Typically
the existing methods assume equal importance across all samples and features in
one dataset. This simplified processing methods overlook the unique
contributions of each feature, and thus may miss important feature information.
As a result, it leads to suboptimal performance in complex datasets with rich
features. To address this problem, we introduce Tabular Feature Weighting with
Transformer, a novel feature weighting approach for tabular data. Our method
adopts Transformer to capture complex feature dependencies and contextually
assign appropriate weights to discrete and continuous features. Besides, we
employ a reinforcement learning strategy to further fine-tune the weighting
process. Our extensive experimental results across various real-world datasets
and diverse downstream tasks show the effectiveness of TFWT and highlight the
potential for enhancing feature weighting in tabular data analysis.


  We consider fireball models where the ejecta have a range of bulk Lorentz
factors, so that the inner (lower $\Gamma$) parts may carry most of the mass,
or even most of the energy. The outer shock and contact discontinuity
decelerate as the fireball sweeps up external matter. This deceleration allows
slower ejecta to catch up, replenishing and reenergizing the reverse shock and
boosting the momentum in the blast wave. In consequence, the energy available
to power the afterglow may substantially exceed that of the burst itself. Such
models allow a wide range of possibilities for the afterglow evolution, even in
the case of spherically symmetric expansion.


  The release of ChatGPT, Gemini, and other large language model has drawn huge
interests on foundations models. There is a broad consensus that foundations
models will be the fundamental building blocks for future AI systems. However,
there is a lack of systematic guidance on the architecture design.
Particularly, the the rapidly growing capabilities of foundations models can
eventually absorb other components of AI systems, posing challenges of moving
boundary and interface evolution in architecture design. Furthermore,
incorporating foundations models into AI systems raises significant concerns
about responsible and safe AI due to their opaque nature and rapidly advancing
intelligence. To address these challenges, the paper first presents an
architecture evolution of AI systems in the era of foundation models,
transitioning from "foundation-model-as-a-connector" to
"foundation-model-as-a-monolithic architecture". The paper then identifies key
design decisions and proposes a pattern-oriented reference architecture for
designing responsible foundation-model-based systems. The patterns can enable
the potential of foundation models while ensuring associated risks.


  Many-electron effects often dramatically modify the properties of reduced
dimensional systems. We report calculations, based on an many-electron Green's
function approach, of electron-hole interaction effects on the optical spectra
of small-diameter single-walled carbon nanotubes. Excitonic effects
qualitatively alter the optical spectra of both semiconducting and metallic
tubes. Excitons are bound by ~ 1 eV in the semiconducting (8,0) tube and by ~
100 meV in the metallic (3,3) tube. These large many-electron effects explain
the discrepancies between previous theories and experiments.


  We study the time evolution of the typical nuclear reactor antineutrino
energy spectrum during reactor ON period and the decay of the residual
antineutrino spectrum after reactor is stopped. We find that relevant
variations of the soft recoil electron spectra produced via weak and magnetic
${\widetilde {\nu}}_{e},e$ scattering process can play a signigicant role in
the current and planned searches for the neutrino magnetic moment at reactors.


  In the study of correlated systems, approximations based on the dynamical
mean-field theory (DMFT) provide a practical way to take local vertex
corrections into account, which capture, respectively, particle-particle
screening at weak coupling and the formation of the local moment at strong
coupling. We show that in both limits the local vertex corrections can be
efficiently parametrized in terms of single-boson exchange, such that the
two-particle physics described by DMFT and its diagrammatic extensions is
recovered to good approximation and at a reduced computational cost. Our
investigation highlights the importance of the frequency-dependent
fermion-boson coupling (Hedin vertex) for local vertex corrections. Namely, at
weak coupling the fermion-spin-boson coupling suppresses the N\'eel temperature
of the DMFT approximation compared to the static mean-field, whereas for large
interaction it facilitates a huge enhancement of local spin-fluctuation
exchange, giving rise to the effective-exchange energy scale $4t^2/U$. We find
that parametrizations of the vertex which neglect the nontrivial part of the
fermion-boson coupling fail qualitatively at strong coupling.


  Correct interpretation of acoustic travel times measured by time-distance
helioseismology is essential to get an accurate understanding of the solar
properties that are inferred from them. It has long been observed that sunspots
suppress p-mode amplitude, but its implications on travel times has not been
fully investigated so far. It has been found in test measurements using a
'masking' procedure, in which the solar Doppler signal in a localized quiet
region of the Sun is artificially suppressed by a spatial function, and using
numerical simulations that the amplitude modulations in combination with the
phase-speed filtering may cause systematic shifts of acoustic travel times. To
understand the properties of this procedure, we derive an analytical expression
for the cross-covariance of a signal that has been modulated locally by a
spatial function that has azimuthal symmetry, and then filtered by a phase
speed filter typically used in time-distance helioseismology. Comparing this
expression to the Gabor wavelet fitting formula without this effect, we find
that there is a shift in the travel times, that is introduced by the amplitude
modulation. The analytical model presented in this paper can be useful also for
interpretation of travel time measurements for non-uniform distribution of
oscillation amplitude due to observational effects.


  The problem of mixed signals occurs in many different contexts; one of the
most familiar being acoustics. The forward problem in acoustics consists of
finding the sound pressure levels at various detectors resulting from sound
signals emanating from the active acoustic sources. The inverse problem
consists of using the sound recorded by the detectors to separate the signals
and recover the original source waveforms. In general, the inverse problem is
unsolvable without additional information. This general problem is called
source separation, and several techniques have been developed that utilize
maximum entropy, minimum mutual information, and maximum likelihood. In
previous work, it has been demonstrated that these techniques can be recast in
a Bayesian framework. This paper demonstrates the power of the Bayesian
approach, which provides a natural means for incorporating prior information
into a source model. An algorithm is developed that utilizes information
regarding both the statistics of the amplitudes of the signals emitted by the
sources and the relative locations of the detectors. Using this prior
information, the algorithm finds the most probable source behavior and
configuration. Thus, the inverse problem can be solved by simultaneously
performing source separation and localization. It should be noted that this
algorithm is not designed to account for delay times that are often important
in acoustic source separation. However, a possible application of this
algorithm is in the separation of electrophysiological signals obtained using
electroencephalography (EEG) and magnetoencephalography (MEG).


  A study of star formation is carried out on 35 giant extragalactic HII
regions (GEHRs) in seven galaxies using optical photometric data in BVR broad
bands and in the emission line of H alpha. Interstellar extinction, metallicity
and nebular contributions to the broad bands are estimated using spectroscopic
data on these objects. Dimensionless diagrams involving B-V and V-R colors and
the flux ratio of Balmer line to B band continuum are used to study star
formation. The cluster colors indicate reduced extinction towards stellar
continuum compared to the values derived from Balmer lines for the ionized gas.
The frequency of detection of classical young (t < 3 Myr) regions with only one
burst of star formation is found to be low as compared to young regions with an
accompanying population rich in red supergiants from a previous burst (t ~ 10
Myr). Reduced extinction towards cluster stars, destruction of ionizing photons
and the existence of older population, often spatially unresolvable from the
younger population, all conspire to make the observed Balmer line equivalent
widths low in a majority of the GEHRs. A scenario of star formation is
suggested which explains many of the observed properties of GEHRs, including
the core-halo structure, reduced extinction for the radiation from stars as
compared to that from the nebular gas, non-detection of young single burst
regions and the co-existence of two populations of different ages.


  For $\Sigma$ an orientable surface of finite topological type having genus at
least 3 (possibly closed or possibly with any number of punctures or boundary
components), we show that the mapping class group $Mod(\Sigma)$ has no faithful
linear representation in any dimension over any field of positive
characteristic.


  In this paper, we clarify the mechanisms underlying a general phenomenon
present in pulse-coupled heterogeneous inhibitory networks: inhibition can
induce not only suppression of the neural activity, as expected, but it can
also promote neural reactivation. In particular, for globally coupled systems,
the number of firing neurons monotonically reduces upon increasing the strength
of inhibition (neurons' death). However, the random pruning of the connections
is able to reverse the action of inhibition, i.e. in a sparse network a
sufficiently strong synaptic strength can surprisingly promote, rather than
depress, the activity of the neurons (neurons' rebirth). Thus the number of
firing neurons reveals a minimum at some intermediate synaptic strength. We
show that this minimum signals a transition from a regime dominated by the
neurons with higher firing activity to a phase where all neurons are
effectively sub-threshold and their irregular firing is driven by current
fluctuations. We explain the origin of the transition by deriving an analytic
mean field formulation of the problem able to provide the fraction of active
neurons as well as the first two moments of their firing statistics. The
introduction of a synaptic time scale does not modify the main aspects of the
reported phenomenon. However, for sufficiently slow synapses the transition
becomes dramatic, the system passes from a perfectly regular evolution to an
irregular bursting dynamics. In this latter regime the model provides
predictions consistent with experimental findings for a specific class of
neurons, namely the medium spiny neurons in the striatum.


  There have been two streams in the 3D detection from point clouds:
single-stage methods and two-stage methods. While the former is more
computationally efficient, the latter usually provides better detection
accuracy. By carefully examining the two-stage approaches, we have found that
if appropriately designed, the first stage can produce accurate box regression.
In this scenario, the second stage mainly rescores the boxes such that the
boxes with better localization get selected. From this observation, we have
devised a single-stage anchor-free network that can fulfill these requirements.
This network, named AFDetV2, extends the previous work by incorporating a
self-calibrated convolution block in the backbone, a keypoint auxiliary
supervision, and an IoU prediction branch in the multi-task head. As a result,
the detection accuracy is drastically boosted in the single-stage. To evaluate
our approach, we have conducted extensive experiments on the Waymo Open Dataset
and the nuScenes Dataset. We have observed that our AFDetV2 achieves the
state-of-the-art results on these two datasets, superior to all the prior arts,
including both the single-stage and the two-stage 3D detectors. AFDetV2 won the
1st place in the Real-Time 3D Detection of the Waymo Open Dataset Challenge
2021. In addition, a variant of our model AFDetV2-Base was entitled the "Most
Efficient Model" by the Challenge Sponsor, showing a superior computational
efficiency. To demonstrate the generality of this single-stage method, we have
also applied it to the first stage of the two-stage networks. Without
exception, the results show that with the strengthened backbone and the
rescoring approach, the second stage refinement is no longer needed.


  In this work we analyze complex scalar fields using a new framework where the
object of noncommutativity $\theta^{\mu\nu}$ represents independent degrees of
freedom. In a first quantized formalism, $\theta^{\mu\nu}$ and its canonical
momentum $\pi_{\mu\nu}$ are seen as operators living in some Hilbert space.
This structure is compatible with the minimal canonical extension of the
Doplicher-Fredenhagen-Roberts (DFR) algebra and is invariant under an extended
Poincar\'e group of symmetry. In a second quantized formalism perspective, we
present an explicit form for the extended Poincar\'e generators and the same
algebra is generated via generalized Heisenberg relations. We also introduce a
source term and construct the general solution for the complex scalar fields
using the Green's function technique.


  A class of meson decay modes sensitive to only one quark topology at leading
G_F order (annihilation of valence quarks through a W) is described. No
experimental observations, nor even upper limits, have been reported for these
decays. This work presents a simpleminded (order-of-magnitude) calculation of
their branching fractions, and compares to results of previous calculations
where available. Although rare, one of these modes (D_s^+ --> rho^+ gamma)
might already be observable at charm experiments, two others (D^+ --> K^{*+}
gamma, B^+ --> D_s^{*+} gamma) should appear at the B factories, and the rest
at hadron colliders.