  We propose a novel method to extract global and local features of functional
time series. The global features concerning the dominant modes of variation
over the entire function domain, and local features of function variations over
particular short intervals within function domain, are both important in
functional data analysis. Functional principal component analysis (FPCA),
though a key feature extraction tool, only focus on capturing the dominant
global features, neglecting highly localized features. We introduce a FPCA-BTW
method that initially extracts global features of functional data via FPCA, and
then extracts local features by block thresholding of wavelet (BTW)
coefficients. Using Monte Carlo simulations, along with an empirical
application on near-infrared spectroscopy data of wood panels, we illustrate
that the proposed method outperforms competing methods including FPCA and
sparse FPCA in the estimation functional processes. Moreover, extracted local
features inheriting serial dependence of the original functional time series
contribute to more accurate forecasts. Finally, we develop asymptotic
properties of FPCA-BTW estimators, discovering the interaction between
convergence rates of global and local features.


  The modeling framework of port-Hamiltonian descriptor systems and their use
in numerical simulation and control are discussed. The structure is ideal for
automated network-based modeling since it is invariant under power-conserving
interconnection, congruence transformations, and Galerkin projection. Moreover,
stability and passivity properties are easily shown. Condensed forms under
orthogonal transformations present easy analysis tools for existence,
uniqueness, regularity, and numerical methods to check these properties.
  After recalling the concepts for general linear and nonlinear descriptor
systems, we demonstrate that many difficulties that arise in general descriptor
systems can be easily overcome within the port-Hamiltonian framework. The
properties of port-Hamiltonian descriptor systems are analyzed,
time-discretization, and numerical linear algebra techniques are discussed.
Structure-preserving regularization procedures for descriptor systems are
presented to make them suitable for simulation and control. Model reduction
techniques that preserve the structure and stabilization and optimal control
techniques are discussed.
  The properties of port-Hamiltonian descriptor systems and their use in
modeling simulation and control methods are illustrated with several examples
from different physical domains. The survey concludes with open problems and
research topics that deserve further attention.


  We establish a Wiman-Valiron theory of a polynomial series based on the
Askey-Wilson operator $\mathcal{D}_q$, where $q\in(0,1)$. For an entire
function $f$ of log-order smaller than $2$, this theory includes (i) an
estimate which shows that $f$ behaves locally like a polynomial consisting of
the terms near the maximal term of its Askey-Wilson series expansion, and (ii)
an estimate of $\mathcal{D}_q^n f$ compared to $f$. We then apply this theory
in studying the growth of entire solutions to difference equations involving
the Askey-Wilson operator.


  This article explores how emerging generative artificial intelligence (GenAI)
models, such as large language models (LLMs), can enhance solution
methodologies within process systems engineering (PSE). These cutting-edge
GenAI models, particularly foundation models (FMs), which are pre-trained on
extensive, general-purpose datasets, offer versatile adaptability for a broad
range of tasks, including responding to queries, image generation, and complex
decision-making. Given the close relationship between advancements in PSE and
developments in computing and systems technologies, exploring the synergy
between GenAI and PSE is essential. We begin our discussion with a compact
overview of both classic and emerging GenAI models, including FMs, and then
dive into their applications within key PSE domains: synthesis and design,
optimization and integration, and process monitoring and control. In each
domain, we explore how GenAI models could potentially advance PSE
methodologies, providing insights and prospects for each area. Furthermore, the
article identifies and discusses potential challenges in fully leveraging GenAI
within PSE, including multiscale modeling, data requirements, evaluation
metrics and benchmarks, and trust and safety, thereby deepening the discourse
on effective GenAI integration into systems analysis, design, optimization,
operations, monitoring, and control. This paper provides a guide for future
research focused on the applications of emerging GenAI in PSE.


  We extend recent low temperature analyses of competing orders in the cuprate
superconductors to the pseudogap regime where all orders are fluctuating. A
universal continuum limit of a classical Ginzburg-Landau functional is used to
characterize fluctuations of the superconducting order: this describes the
crossover from Gaussian fluctuations at high temperatures to the vortex-binding
physics near the onset of global phase coherence. These fluctuations induce
affiliated corrections in the correlations of other orders, and in particular,
in the different realizations of charge order. Implications for scanning
tunnelling spectroscopy and neutron scattering experiments are noted: there may
be a regime of temperatures near the onset of superconductivity where the
charge order is enhanced with increasing temperatures.


  Aims: To investigate magnetic reconnection rates during the coalescence of
two current loops in the solar chromosphere, by altering the neutral-hydrogen
to proton density ratio, ioniziation/recombination coefficients, collision
frequency and relative helicity of the loops. Methods: 2.5D numerical
simulations of the chromosphere were conducted using a newly developed
two-fluid (ion-neutral) numerical code. Developed from the Artificial Wind
scheme, the numerical code includes the effects of ion-neutral collisions,
ionization/recombination, thermal/resistive diffusivity and
collisional/resistive heating. Results: It was found that the rates of magnetic
reconnection strongly depend on the neutral-hydrogen to proton density ratio;
increasing the density ratio by a thousand-fold decreased the rate of magnetic
reconnection by twenty-fold. This result implies that magnetic reconnection
proceeds significantly faster in the upper chromosphere, where the density of
ions (protons) and neutral-hydrogen is comparable, than in the lower
chromosphere where the density of neutral-hydrogen is over a thousand times the
ion density. The inclusion of ionization/recombination, an important physics
effect in the chromosphere, increases the total reconnected magnetic flux, but
does not alter the rate of magnetic reconnection. Reductions in the ion-neutral
collision frequency, result in small increases to the rates of magnetic
reconnection. The relative helicity of the two current loops was not observed
to have any significant effect on the rates of magnetic reconnection.
Conclusions: The magnetic reconnection rates of coalescing current loops are
strongly affected by the inclusion of neutral-hydrogen particles.


  Privacy technologies have become extremely prevalent in recent years from
secure communication channels to the Tor network. These technologies were
designed to provide privacy and security for users, but these ideals have also
led to increased criminal use of the technologies. Privacy and anonymity are
always sought after by criminals, making these technologies the perfect
vehicles for committing crimes on the Internet. This paper will analyze the
rising threat of subverting privacy technologies for criminal or nefarious use.
It will look at recent research in this area and ultimately reach conclusions
on the seriousness of this issue.


  We show that with respect to the Haar state, the joint distributions of the
generators of Van Daele and Wang's free orthogonal quantum groups are modeled
by free families of generalized circular elements and semicircular elements in
the large (quantum) dimension limit. We also show that this class of quantum
groups acts naturally as distributional symmetries of almost-periodic free
Araki-Woods factors.


  The introduction of Fuzzy Relational Equations (FREs) has made problems that
were unsolvable using algebraic linear equations into solvable ones. FREs have
been applied to problemsin medicine, industry, transportation and all types of
social problems where the data is an unsupervised one. Yet, FREs lack the
capacity to tackle problems where an element of indeterminacy is involved. This
book develops the new concept of Neutrosophic Relational Equations (NREs) that
have the capacity to analyze problems with indeterminacy. Here, earlier models
on FREs are analyzed and new NRE models, with practical applications, are
presented.


  Communities are subsets of a network that are densely connected inside and
share only few connections to the rest of the network. The aim of this research
is the development and evaluation of an efficient algorithm for detection of
overlapping, fuzzy communities. The algorithm gets as input some members of
each community that we aim to discover. We call these members seed nodes. The
algorithm then propagates this information by using random walks that start at
non-seed nodes and end as they reach a seed node. The probability that a random
walk starting at a non-seed node $v$ ends at a seed node $s$ is then equated
with the probability that $v$ belongs to the communities of $s$. The algorithm
runs in time $\tilde{O}(l \cdot m \cdot \log n)$, where $l$ is the number of
communities to detect, $m$ is the number of edges, $n$ is the number of nodes.
The $\tilde{O}$-notation hides a factor of at most $(\log \log n)^2$. The LFR
benchmark proposed by Lancichinetti et al.\ is used to evaluate the performance
of the algorithm. We found that, given a good set of seed nodes, it is able to
reconstruct the communities of a network in a meaningful manner.


  The behavior of non-local thermal-equilibrium (NLTE) plasmas plays a central
role in many fields of modern-day physics, such as laser-produced plasmas,
astrophysics, inertial or magnetic confinement fusion devices, or X-ray
sources. The proper description of these media in stationary cases requires to
solve linear systems of thousands or more rate equations. A possible
simplification for this arduous numerical task may lie in some type of
statistical average, such as configuration or superconfiguration average.
However to assess the validity of this procedure and to handle cases where
isolated lines play an important role, it may be important to deal with
detailed levels systems. This involves matrices with sometimes billions of
elements, which are rather sparse but still involve thousands of diagonals. We
propose here a numerical algorithm based on the LU decomposition for such
linear systems. This method turns out to be orders of magnitude faster than the
traditional Gauss elimination. And at variance with alternate methods based on
conjugate gradients or minimization, no convergence or accuracy issues have
been faced. Some examples are discussed in connection with the krypton and
tungsten cases discussed at the last NLTE meeting. Furthermore, to assess the
validity of configuration average, several criteria are discussed. While a
criterion based on detailed balance is relevant in cases not too far from LTE
but insufficient otherwise, an alternate criterion based on the use of a
fictive configuration temperature is proposed and successfully tested. It
appears that detailed calculations are sometimes necessary, which supports the
search for an efficient solver as the one proposed here.


  An approximate vacuum wave functional $\Psi_0$ is proposed for
$2+1$-dimensional Yang-Mills theories. Using $\Psi_0$, one can compute the
$0^{++}$ glueball mass $M_G$ in terms of the string tension. By using the idea
of dimensional reduction, a prediction for $M_G$ can be made in $3+1$
dimensions. One finds $M_G \approx 1.5$ GeV.


  We use surface acoustic waves of 1 and 3 GHz in hybrid piezoelectric-magnetic
systems with either cobalt or nickel as a magnetic layer to generate
magnetoacoustic waves and directly image them using stroboscopic X-ray magnetic
circular dichroism imaging. Our measurements visualize and quantify the
amplitudes of both acoustic and magnetic components of the magnetoacoustic
waves, which are generated in the ferromagnetic layer and can propagate over
millimeter distances. Additionally, we quantifiedy the magnetoelastic strain
component for cobalt and nickel through micromagnetic simulations. We obtained
a drop in the magnetoacoustic signal at 3 GHz suggesting a speed limit for the
efficient magnetoelastic coupling in our hybrid devices.


  We have developed an affordable, portable college level radio telescope for
amateur radio astronomy which can be used to provide hands-on experience with
the fundamentals of a radio telescope and an insight into the realm of radio
astronomy. With our set-up one can measure brightness temperature and flux of
the Sun at 11.2 GHz and calculate the beam width of the antenna. The set-up
uses commercially available satellite television receiving system and parabolic
dish antenna. We report the detection of point sources like Saturn and extended
sources like the galactic arm of the Milky way. We have also developed python
pipeline, which are available for free download, for data acquisition and
visualization.


  A connection is established between transonic sound waves propagating along a
de Laval nozzle and quasinormal modes emitted from hairy black holes obtained
with the gravitational decoupling method applied to the Reissner-Nordstr\"om
geometry. Aerodynamical features provide an analogue setup to experimentally
test fluid flow perturbations in a de Laval nozzle producing quasinormal modes.
In particular, nozzle shape, pressure, Mach number, temperature, density, and
thrust coefficient profiles are determined as functions of the black hole
parameters for several multipole numbers. The black hole quasinormal mode
frequencies are also investigated for different overtones, evaluating the
quality factor of the nozzle.


  During In Vitro Fertilisation (IVF), combining time-lapse contrast microscopy
with suitable image processing techniques could facilitate non-invasive
classification of oocyte health, driving oocyte selection to maximise success
rates. One image processing technique, Differential Dynamic Microscopy (DDM),
has been used in a variety of microscopy settings including bright field, dark
field and fluorescence. However, in some applications, effects stemming from
the choice of microscopy may invalidate underlying assumptions of DDM. Here, we
study the DDM analysis of differential interference contrast (DIC) microscopy
movies. DIC exhibits a characteristic shadowing effect that gives the illusion
of a 3D appearance, which we show causes deformation of the output DDM matrix.
We present a mathematical description of this deformation, and conclude that,
when studying isotropic motion, no account of the DIC shadow needs to be
considered during DDM analysis. We validate our conclusions with simulated
particle data, and with DIC images of colloidal dispersions. Although this
conclusion does not generally extend to anisotropic motion, we demonstrate that
for directed advection and diffusion behaviour, parameter fitting invariance
still holds. These results validate the current practice of applying DDM to
DIC, and are a foundation for further exploration of DDM in other
phase-contrast image datasets.


  The aim of this paper is twofold: First we give an explicit construction of
the infinitesimal deformations of the category Coh(X) of coherent sheaves on a
smooth projective variety X. Secondly we show that any Fourier-Mukai transform
$/Phi/colon D^b(X)/to D^b(Y)$ extends to an equivalence between the derived
categories of the deformed Abelian categories.


  The fact, that $^4$He atoms on different concentric circular paths around the
axis of a quantum vortex move with identically equal angular momentum, which
represents an important aspect of superfluidity of He-II, has been used to
discover a model which can explain the {\it typical nature} of experimentally
observed $N$ (number of $^4He$ atoms) dependence of the rotational constant
($B$) of the rotor part of a cluster M:He$_N$. It reveals how exactly
superfluidity is related to the said dependence of $B$ on $N$. We believe that
this model, when used with simulation techniques, would render results that
would agree closely with experiments.


  We consider the recently proposed Bound State Conjecture for quantum field
theory in the context of solitons in two dimensional $\phi^4$ scalar field
theory. We calculate the quantum correction to the size of the soliton which,
taken together with the known mass correction, shows behaviour consistent with
regarding the soliton as a bound state, and with the conjecture.


  Using Bieberbach groups we study multipermutation involutive solutions to the
Yang-Baxter equation. We use a linear representation of the structure group of
an involutive solution to study the unique product property in such groups. An
algorithm to find subgroups of a Bieberbach group isomorphic to the Promislow
subgroup is introduced and then used in the case of structure group of
involutive solutions. To extend the results related to retractability to
non-involutive solutions, following the ideas of Meng, Ballester-Bolinches and
Romero, we develop the theory of right $p$-nilpotent skew braces. The theory of
left $p$-nilpotent skew braces is also developed and used to give a short proof
of a theorem of Smoktunowicz in the context of skew braces.


  In this review, an overview is given of several recent generalizations of the
Fourier transform, related to either the Lie algebra sl_2 or the Lie
superalgebra osp(1|2). In the former case, one obtains scalar generalizations
of the Fourier transform, including the fractional Fourier transform, the Dunkl
transform, the radially deformed Fourier transform and the super Fourier
transform. In the latter case, one has to use the framework of Clifford
analysis and arrives at the Clifford-Fourier transform and the radially
deformed hypercomplex Fourier transform. A detailed exposition of all these
transforms is given, with emphasis on aspects such as eigenfunctions and
spectrum of the transform, characterization of the integral kernel and
connection with various special functions.


  The discrepancies between $b\to s\ell^+\ell^-$ data and the corresponding
Standard Model predictions constitute the most significant hints for new
physics (at the TeV scale or below) currently available. In fact, many
scenarios that can account for these anomalies have been proposed in the
literature. However, only a single light new physics explanation, i.e. with a
mass below the $B$ meson scale, is possible: a light $Z^\prime$ boson. In this
article, we point out that improved limits on $B\to K^{(*)}\nu\nu$, including
the experimental sensitivities required for a proper treatment of the
necessarily sizable $Z^\prime$ width, together with the forthcoming Belle~II
analyses of $e^+e^-\to\mu^+\mu^-+{\rm invisible}$, can rule out a $Z^\prime$
explanation of $b\to s\ell^+\ell^-$ data with a mass below $\approx4\,$GeV.
Importantly, such a light $Z^\prime$ is the only viable single particle
solution to the $b\to s\ell^+\ell^-$ anomalies predicting $R(K^{(*)})>0$ in
high $q^2$ bins, therefore providing an essential consistency test of data.


  (2+1) dimensional diffusion equation is considered within the framework of
equivalence transformations. Generators for the group are obtained and
admissible transformations between linear and nonlinear equations are examined.
It is shown that transformations between linear and nonlinear equations are
possible provided that the generators of independent variables depend on the
dependent variable. Exact solutions for some nonlinear equations are obtained.
Differential invariants related to the transformation groups are investigated
and the results are compared with the direct integration method.


  We discuss a model of formation of extragalactic radio sources when the
parent optical galaxy has a large-scale dipolar magnetic field. The study of
dynamics of ejected from the central part of optical galaxy clouds of
relativistic particles in dipolar magnetic field gives a possibility to explain
main morphological features and physical properties of formed extragalactic
radio sources. We bring some results of statistical analyses and correlations
between physical parameters for more than 500 radio sources. In appendix we
present the data of all used extragalactic radio sources with the references
for them.


  We relate the Brauer group of a smooth variety over a p-adic field to the
geometry of the special fibre of a regular model, using the purity theorem in
\'etale cohomology. As an illustration, we describe how the Brauer group of a
smooth del Pezzo surface is determined by the singularity type of its
reduction. We then relate the evaluation of an element of the Brauer group to
the existence of points on certain torsors over the special fibre; we use this
to describe situations when the evaluation is constant, and situations when the
evaluation is surjective. In the latter case, we describe how this surjectivity
can be used to prove vanishing of the Brauer-Manin obstruction on varieties
over number fields.


  This work considers the low-rank approximation of a matrix $A(t)$ depending
on a parameter $t$ in a compact set $D \subset \mathbb{R}^d$. Application areas
that give rise to such problems include computational statistics and dynamical
systems. Randomized algorithms are an increasingly popular approach for
performing low-rank approximation and they usually proceed by multiplying the
matrix with random dimension reduction matrices (DRMs). Applying such
algorithms directly to $A(t)$ would involve different, independent DRMs for
every $t$, which is not only expensive but also leads to inherently non-smooth
approximations. In this work, we propose to use constant DRMs, that is, $A(t)$
is multiplied with the same DRM for every $t$. The resulting
parameter-dependent extensions of two popular randomized algorithms, the
randomized singular value decomposition and the generalized Nystr\"{o}m method,
are computationally attractive, especially when $A(t)$ admits an affine linear
decomposition with respect to $t$. We perform a probabilistic analysis for both
algorithms, deriving bounds on the expected value as well as failure
probabilities for the approximation error when using Gaussian random DRMs.
Both, the theoretical results and numerical experiments, show that the use of
constant DRMs does not impair their effectiveness; our methods reliably return
quasi-best low-rank approximations.


  The evolution with cosmic time of the star formation rate density (SFRD) and
of the "Main Sequence" star formation rate-stellar mass relations are two well
established observational facts. In this paper the implications of these two
relations combined are analytically explored, showing that quenching of star
formation must start already at very early cosmic times and the quenched
fraction then dominates ever since over the star forming one. Thus, a simple
picture of the cosmic evolution of the global SFRD is derived, in terms of the
interplay between star formation and its quenching.


  With the advent of virtual reality technology, omnidirectional image (ODI)
rescaling techniques are increasingly embraced for reducing transmitted and
stored file sizes while preserving high image quality. Despite this progress,
current ODI rescaling methods predominantly focus on enhancing the quality of
images in equirectangular projection (ERP) format, which overlooks the fact
that the content viewed on head mounted displays (HMDs) is actually a rendered
viewport instead of an ERP image. In this work, we emphasize that focusing
solely on ERP quality results in inferior viewport visual experiences for
users. Thus, we propose ResVR, which is the first comprehensive framework for
the joint Rescaling and Viewport Rendering of ODIs. ResVR allows obtaining LR
ERP images for transmission while rendering high-quality viewports for users to
watch on HMDs. In our ResVR, a novel discrete pixel sampling strategy is
developed to tackle the complex mapping between the viewport and ERP, enabling
end-to-end training of ResVR pipeline. Furthermore, a spherical pixel shape
representation technique is innovatively derived from spherical differentiation
to significantly improve the visual quality of rendered viewports. Extensive
experiments demonstrate that our ResVR outperforms existing methods in viewport
rendering tasks across different fields of view, resolutions, and view
directions while keeping a low transmission overhead.


  We consider a multipair decode-and-forward relay channel, where multiple
sources transmit simultaneously their signals to multiple destinations with the
help of a full-duplex relay station. We assume that the relay station is
equipped with massive arrays, while all sources and destinations have a single
antenna. The relay station uses channel estimates obtained from received pilots
and zero-forcing (ZF) or maximum-ratio combining/maximum-ratio transmission
(MRC/MRT) to process the signals. To reduce significantly the loop interference
effect, we propose two techniques: i) using a massive receive antenna array; or
ii) using a massive transmit antenna array together with very low transmit
power at the relay station. We derive an exact achievable rate in closed-form
for MRC/MRT processing and an analytical approximation of the achievable rate
for ZF processing. This approximation is very tight, especially for large
number of relay station antennas. These closed-form expressions enable us to
determine the regions where the full-duplex mode outperforms the half-duplex
mode, as well as, to design an optimal power allocation scheme. This optimal
power allocation scheme aims to maximize the energy efficiency for a given sum
spectral efficiency and under peak power constraints at the relay station and
sources. Numerical results verify the effectiveness of the optimal power
allocation scheme. Furthermore, we show that, by doubling the number of
transmit/receive antennas at the relay station, the transmit power of each
source and of the relay station can be reduced by 1.5dB if the pilot power is
equal to the signal power, and by 3dB if the pilot power is kept fixed, while
maintaining a given quality-of-service.


  We examine Hamilton-Jacobi equations driven by fully nonlinear degenerate
elliptic operators in the presence of superlinear Hamiltonians. By exploring
the Ishii-Jensen inequality, we prove that viscosity solutions are locally
Lipschitz-continuous, with estimates depending on the structural conditions of
the problem. We close the paper with an application of our findings to a
two-phase free boundary problem.


  The purpose of this work is to explore the existence and properties of
reproducing kernel Hilbert subspaces of $L^2(\C, \, d^2z/\pi)$ based on subsets
of complex Hermite polynomials. The resulting coherent states (CS) form a
family depending on a nonnegative parameter $s$. We examine some interesting
issues, mainly related to CS quantization, like the existence of the usual
harmonic oscillator spectrum despite the absence of canonical commutation
rules. The question of mathematical and physical equivalences between the
$s$-dependent quantizations is also considered.


  Let $G$ be the unramified unitary group $U(2, 1)(E/F)$ over a non-archimedean
local field $F$ of odd residue characteristic $p$. In this paper, for any
supersingular representation of $G$ that contains the Steinberg weight, we
prove its pro-$p$-Iwahori invariants, as a right module over the
pro-$p$-Iwahori--Hecke algebra of $G$, is \emph{not} simple.


  The goal of a series of papers is to define $G$-actions on various
$A$-fibered structures, where $G$ is a finite group and $A$ is an abelian
group. One prominent such example is the $A$-fibered Burnside ring. If
$A=\mathbb{C}^\times$, it is also called the ring of monomial representations
(introduced by Dress in \cite{Dress1971}) and is the natural home for the
canonical induction formula (see \cite{Boltje1990}). In this first part of the
series, motivated by constructions in \cite{BoucMutlu}, we introduce
$A$-fibered structures on posets, on abstract simplicial complexes, and on
$A$-bundles over topological spaces, together with natural notions of homotopy,
and functors between these structures respecting homotopy. In a sequel we will
continue with $G$-representations in these $A$-fibered structures and associate
to them elements in the $A$-fibered Burnside ring.


  We show that an Anderson Hamiltonian describing a quantum dot connected to
multiple leads is integrable. A general expression for the non-linear
conductance is obtained by combining the Bethe ansatz exact solution with
Landauer-B\"uttiker theory. In the Kondo regime, a closed form expression is
given for the matrix conductance at zero temperature and when all the leads are
close to the symmetric point. A bias-induced splitting of the Kondo resonance
is possible for three or more leads. Specifically, for $N$ leads, with each at
a different chemical potential, there can be $N-1$ Kondo peaks in the
conductance.


  The effects of electromagnetic fields (EMF) have been widely debated
concerning their role in chemical reactions. Reactions usually took hours or
days to complete, and have been shown to happen a thousand times faster using
EMF radiations. This work develops a formalism and a computer program to
evaluate and quantify the EMF effects in chemical reactions. The master
equation employed in this program solves the internal energy of the reaction
under EMFs while including collisional effects. Multiphoton absorption and
emission are made possible with the transitioning energy close to the EMF and
are influenced by the dielectric properties of the system. Dimethyl Sulfoxide
and Benzyl Chloride are simulated under different EMF intensities. The results
show that EMF absorption is closely related to the collisional redistribution
of energy in molecules. The EMF effect can be interpreted as a shift of the
thermodynamic equilibrium. Under such nonequilibrium energy distribution, the
"temperature" is not a reliable quantity for defining the state of the system.


  The Riemann correlator with appropriately raised indices characterizes in a
gauge-invariant way the quantum metric fluctuations around de Sitter spacetime
including loop corrections from matter fields. Specializing to conformal fields
and employing a method that selects the de Sitter-invariant vacuum in the
Poincar\'e patch, we obtain the exact result for the Riemann correlator through
order $H^4/m_\mathrm{p}^4$. The result is expressed in a manifestly de
Sitter-invariant form in terms of maximally symmetric bitensors. Its behavior
for both short and long distances (sub- and superhorizon scales) is analyzed in
detail. Furthermore, by carefully taking the flat-space limit, the explicit
result for the Riemann correlator for metric fluctuations around Minkowki
spacetime is also obtained. Although the main focus is on free scalar fields
(our calculation corresponds then to one-loop order in the matter fields), the
result for general conformal field theories is also derived.


  We develop a new numerical approach to describe the action of ram pressure
stripping (RPS) within a semi-analytic model of galaxy formation and evolution
which works in combination with non-radiative hydrodynamical simulations of
galaxy clusters. The new feature in our method is the use of the gas particles
to obtain the kinematical and thermodynamical properties of the intragroup and
intracluster medium (ICM). This allows a self-consistent estimation of the RPS
experienced by satellite galaxies. We find that the ram pressure (RP) in the
central regions of clusters increases approximately one order of magnitude
between z = 1 and 0, consistent with the increase in the density of the ICM.
The mean RP experienced by galaxies within the virial radius increases with
decreasing redshift. In clusters with virial masses M_vir ~10^15 h^-1 M_Sun,
over 50 per cent of satellite galaxies have experienced RP ~10^(-11) h^2 dyn
cm^-2 or higher for z <= 0.5. In smaller clusters (M_vir ~10^14 h^-1 M_Sun) the
mean RP are approximately one order of magnitude lower at all redshifts. RPS
has a strong effect on the cold gas content of galaxies for all cluster masses.
At z = 0, over 70 per cent of satellite galaxies within the virial radius are
completely depleted of cold gas. For the more massive clusters the fraction of
depleted galaxies is already established at z ~ 1, whereas for the smaller
clusters this fraction increases appreciably between z = 1 and 0. This
indicates that the rate at which the cold gas is stripped depends on the virial
mass of the host cluster. Compared to our new approach, the use of an analytic
profile to describe the ICM results in an overestimation of the RP larger than
50 per cent for z >= 0.5.


  We construct the Penrose limit backgrounds in closed forms along the generic
null geodesics for the near-horizon geometries of D1, D3, D5, NS1 and NS5
branes. The Penrose limit metrics of D1, D5 and NS1 have non-trivial dependence
of the light-cone time coordinate, while those of D3 and NS5 have no its
dependence. We study the Penrose limits on the marginal 1/4 supersymmetric
configurations of standard intersecting branes, such as the NS-NS intersection
of NS1 and NS5, the R-R intersections of Dp and Dq over some spatial dimensions
and the mix intersections of NS5 and Dp over (p -1)-dimensional spaces. They
are classified into three types that correspond to the Penrose limits of D1, D3
and D5 backgrounds.


  A natural requirement of many distributed structures is fault-tolerance:
after some failures, whatever remains from the structure should still be
effective for whatever remains from the network. In this paper we examine
spanners of general graphs that are tolerant to vertex failures, and
significantly improve their dependence on the number of faults $r$, for all
stretch bounds.
  For stretch $k \geq 3$ we design a simple transformation that converts every
$k$-spanner construction with at most $f(n)$ edges into an $r$-fault-tolerant
$k$-spanner construction with at most $O(r^3 \log n) \cdot f(2n/r)$ edges.
Applying this to standard greedy spanner constructions gives $r$-fault tolerant
$k$-spanners with $\tilde O(r^{2} n^{1+\frac{2}{k+1}})$ edges. The previous
construction by Chechik, Langberg, Peleg, and Roddity [STOC 2009] depends
similarly on $n$ but exponentially on $r$ (approximately like $k^r$).
  For the case $k=2$ and unit-length edges, an $O(r \log n)$-approximation
algorithm is known from recent work of Dinitz and Krauthgamer [arXiv 2010],
where several spanner results are obtained using a common approach of rounding
a natural flow-based linear programming relaxation. Here we use a different
(stronger) LP relaxation and improve the approximation ratio to $O(\log n)$,
which is, notably, independent of the number of faults $r$. We further
strengthen this bound in terms of the maximum degree by using the \Lovasz Local
Lemma.
  Finally, we show that most of our constructions are inherently local by
designing equivalent distributed algorithms in the LOCAL model of distributed
computation.


  The trans-Planckian theory is a model that realizes concretely the Born
reciprocity idea, which is the postulate of absolute equivalence between
coordinate $x$ and momenta $p$. This model is intrinsically global, and thus it
is naturally implemented in a cosmological setting. Cosmology and Born
reciprocity are made for each other. Inflation provides the essential mechanism
to suppress the terms coming from the dual part of the action. The
trans-Planckian theory provides an explanation for the present acceleration of
the universe scale factor. This is possible just considering a simple model
that contains gravity, one gauge field plus one matter field (to be identified
with dark matter), together with the reciprocity principle.


  High precision trigonometric parallaxes from the HIPPARCOS satellite and
accurate metal abundances ([Fe/H], [O/Fe], and [alpha/Fe]) from high resolution
spectroscopy for about 30 local subdwarfs have been used to derive distances
and ages for a carefully selected sample of nine globular clusters. We find
that HIPPARCOS parallaxes are smaller than the corresponding ground-based
measurements leading, to a longer distance scale (~ 0.2 mag) and to ages ~ 2.8
Gyr younger. The relation between the zero age horizontal branch (ZAHB)
absolute magnitude and metallicity for the nine programme clusters is :
Mv(ZAHB) = (0.22 +/- 0.09)([Fe/H]+1.5) + (0.48 +/- 0.04) The corresponding
Large Magellanic Cloud distance modulus is (m-M)o=18.61 +/- 0.07. The age of
the bona fide old globular clusters (Oosterhoff II and Blue Horizontal Branch)
based on the absolute magnitude of the turn-off is: Age = 11.8 (+2.1/-2.5) Gyr
The present age of globular clusters does no longer conflict with standard
inflationary models for the Universe.


  The hard sphere model is known to show a liquid-solid phase transition, with
the solid expected to be either face centered cubic or hexagonal close packed.
The difference in free energy between the two structures is very small and
various attempts have been made to determine which one is the more stable. We
contrast the different approaches and extend one.


  We review some recent developments in the understanding of field theories in
the perturbative regime. In particular, we discuss the notions of analyticity,
unitarity and locality, and therefore the singularity structure of scattering
amplitudes in general interacting theories. We describe their tree-level
structure and their on-shell representations, as well as the links between the
tree-level structure itself and the structure of the loop amplitudes. Finally,
we describe the on-shell diagrammatics recently proposed both on general
grounds and in the remarkable example of planar supersymmetric theories. This
review is partially based on lectures given at: Dipartimento di Fisica and
INFN, Universit\`a di Bologna; Departamento de F{\i}sica de Part{\i}culas,
Universidade de Santiago de Compostela; and as part of the program Strings@ar
Lectures on Advanced Topics of High Energy Physics held at the IAFE


  Atomic rearrangements within crystals lie at the foundation of
electron-phonon-coupled phenomena such as metal-insulator transition and
superconductivity. Advanced laser-pump-probe studies have recently focused on
various charge-density-wave (CDW) materials to sharpen our understanding of the
charge-lattice entanglement, where non-thermal melting of the CDW state is
evident from the enhanced Bragg diffraction peak intensities - attributed to
the dominance of the metal-atom dynamics over the nonmetal-anion one. Here
using ultrafast MeV electron diffraction on the prototypical CDW material
1T-TaSeTe, we observe an unusual coexistence of systematically enhanced and
suppressed Bragg peak intensities upon the CDW suppression, indicating a
dominance of nonmetal-anion dynamics during photoexcitation. By tracking these
atomic trajectories quantitatively through the ultrafast process, we identify a
transient state that manifests itself as an unexpected decoupling of the Ta and
Se/Te sublattices. These findings unambiguously unveil a new kind of laser
manipulations of lattice order parameters, which has potentials in creating new
quantum states and discerning hidden phases such as intra-unit-cell orders.


  We consider the wireless Rayleigh fading relay channel with finite complex
input constellations. Assuming global knowledge of the channel state
information and perfect synchronization, upper and lower bounds on the
achievable rate, for the full-duplex relay, as well as the more practical
half-duplex relay (in which the relay cannot transmit and receive
simultaneously), are studied. Assuming the power constraint at the source node
and the relay node to be equal, the gain in rate offered by the use of relay
over the direct transmission (without the relay) is investigated. It is shown
that for the case of finite complex input constellations, the relay gain
attains the maximum at a particular SNR and at higher SNRs the relay gain tends
to become zero. Since practical schemes always use finite complex input
constellation, the above result means that the relay offers maximum advantage
over the direct transmission when we operate at a particular SNR and offers no
advantage at very high SNRs. This is contrary to the results already known for
the relay channel with Gaussian input alphabet.


  We study the quantitative properties of Lipschitz mappings from Euclidean
spaces into metric spaces. We prove that it is always possible to decompose the
domain of such a mapping into pieces on which the mapping "behaves like a
projection mapping" along with a "garbage set" that is arbitrarily small in an
appropriate sense. Moreover, our control is quantitative, i.e., independent of
both the particular mapping and the metric space it maps into. This improves a
theorem of Azzam-Schul from the paper "Hard Sard", and answers a question left
open in that paper. The proof uses ideas of quantitative differentiation, as
well as a detailed study of how to supplement Lipschitz mappings by additional
coordinates to form bi-Lipschitz mappings.


  In this work, we consider the effect of a constant anomalous magnetic moment
(AMM) of quarks in the SU(2) Nambu--Jona-Lasinio model in the mean field
approximation. To this end, we use the Schwinger {\it ansatz}, which represents
a linear magnetic field term in the Lagrangian. A regularization method
inspired in the vacuum magnetic regularization (VMR) is adopted to avoid
ultraviolet divergences. Our results indicate a smooth decrease of the
pseudocritical temperature and quark condensates for magnetic fields $B \leq
0.1$ GeV$^2$ when a sizable AMM is considered. We found only a small window for
Inverse Magnetic Catalysis (IMC), in contradiction with NJL predictions made in
the literature. For a low value of AMM, we observe for all ranges of magnetic
fields considered that the pseudocritical temperature increases with the
magnetic field, indicating only Magnetic Catalysis (MC). In our approach, for
nonvanishing quark AMM, the chiral symmetry restoration happens always as a
smooth crossover and never turns into a first order phase transition.


  There is growing interest in ensuring that large language models (LLMs) align
with human values. However, the alignment of such models is vulnerable to
adversarial jailbreaks, which coax LLMs into overriding their safety
guardrails. The identification of these vulnerabilities is therefore
instrumental in understanding inherent weaknesses and preventing future misuse.
To this end, we propose Prompt Automatic Iterative Refinement (PAIR), an
algorithm that generates semantic jailbreaks with only black-box access to an
LLM. PAIR -- which is inspired by social engineering attacks -- uses an
attacker LLM to automatically generate jailbreaks for a separate targeted LLM
without human intervention. In this way, the attacker LLM iteratively queries
the target LLM to update and refine a candidate jailbreak. Empirically, PAIR
often requires fewer than twenty queries to produce a jailbreak, which is
orders of magnitude more efficient than existing algorithms. PAIR also achieves
competitive jailbreaking success rates and transferability on open and
closed-source LLMs, including GPT-3.5/4, Vicuna, and Gemini.


  Experimental groups are now fabricating quantum processors powerful enough to
execute small instances of quantum algorithms and definitively demonstrate
quantum error correction that extends the lifetime of quantum data, adding
urgency to architectural investigations. Although other options continue to be
explored, effort is coalescing around topological coding models as the most
practical implementation option for error correction on realizable
microarchitectures. Scalability concerns have also motivated architects to
propose distributed memory multicomputer architectures, with experimental
efforts demonstrating some of the basic building blocks to make such designs
possible. We compile the latest results from a variety of different systems
aiming at the construction of a scalable quantum computer.


  XAI (eXplanable AI) techniques that have the property of explaining the
reasons for their conclusions, i.e. explainability or interpretability, are
attracting attention. XAI is expected to be used in the development of forensic
science and the justice system. In today's forensic and criminal investigation
environment, experts face many challenges due to large amounts of data, small
pieces of evidence in a chaotic and complex environment, traditional laboratory
structures and sometimes inadequate knowledge. All these can lead to failed
investigations and miscarriages of justice. In this paper, we describe the
application of one logical approach to crime scene investigation. The subject
of the application is ``The Adventure of the Speckled Band'' from the Sherlock
Holmes short stories. The applied data is the knowledge graph created for the
Knowledge Graph Reasoning Challenge. We tried to find the murderer by inferring
each person with the motive, opportunity, and method. We created an ontology of
motives and methods of murder from dictionaries and dictionaries, added it to
the knowledge graph of ``The Adventure of the Speckled Band'', and applied
scripts to determine motives, opportunities, and methods.


  The mechanism by which black holes return the absorbed information to the
outside world is reconsidered, and described in terms of a set of mutually
non-interacting modes. Our mechanism is based on the mostly classical
gravitational back-reaction. The diagonalized formalism is particularly useful
for further studies of this process. Although no use is made of string theory,
our analysis appears to point towards an ensuing string-like interaction. It is
shown how black hole entropy can be traced down to classical gravitational
back-reaction.


  The NIO1 experiment, built and operated at Consorzio RFX, hosts an RF
negative ion source, from which it is possible to produce a beam of maximum 130
mA in H- ions, accelerated up to 60 kV. For the preliminary tests of the
extraction system the source has been operated in oxygen, whose high
electronegativity allows to reach useful levels of extracted beam current. The
efficiency of negative ions extraction is strongly influenced by the electron
density and temperature close to the Plasma Grid, i.e. the grid of the
acceleration system which faces the source. To support the tests, these
parameters have been measured by means of the Optical Emission Spectroscopy
diagnostic. This technique has involved the use of an oxygen-argon mixture to
produce the plasma in the source. The intensities of specific Ar I and Ar II
lines have been measured along lines of sight close to the Plasma Grid, and
have been interpreted with the ADAS package to get the desired information.
This work will describe the diagnostic hardware, the analysis method and the
measured values of electron density and temperature, as function of the main
source parameters (RF power, pressure, bias voltage and magnetic filter field).
The main results show that not only electron density but also electron
temperature increase with RF power; both decrease with increasing magnetic
filter field. Variations of source pressure and plasma grid bias voltage appear
to affect only electron temperature and electron density, respectively.


  The Heisenberg-Kitaev model is a paradigmatic model to describe the magnetism
in honeycomb-lattice Mott insulators with strong spin-orbit coupling, such as
A$_2$IrO$_3$ (A = Na, Li) and $\alpha$-RuCl$_3$. Here we study in detail the
physics of the Heisenberg-Kitaev model in an external magnetic field. Using a
combination of Monte-Carlo simulations and spin-wave theory we map out the
classical phase diagram for different directions of the magnetic field. Broken
SU(2) spin symmetry renders the magnetization process rather complex, with
sequences of phases and metamagnetic transitions. In particular, we find
various large-unit-cell and multi-Q phases including a vortex-crystal phase for
a field in the [111] direction. We also discuss quantum corrections in the
high-field phase.


  I review the large scale global magnetic field structure of our Galaxy, using
all information available for disk fields, halo fields and magnetic fields near
the Galactic center (GC). In the local disk of our Galaxy, RM and dispersion
measure (DM) data of nearby pulsars yield the strength of regular field as
1.8$\mu$G, with a pitch angle of about $8\degr$, and a bisymmetric spiral
structure. There are at least four, maybe five, field reversals from the Norma
arm to the outskirts of our Galaxy. In the thick disk or Galactic halo, large
scale toroidal magnetic fields, with opposite field directions in the Southern
and Northern Galaxy, have been revealed by the antisymmetric RM sky towards the
inner Galaxy. This signature of the A0 dynamo-mode field structure is
strengthened by the indication of a poloidal field of dipole form, that is the
transition of the RM signs probably shifted from $l\sim0\degr$ to
$l\sim+10\degr$. The local vertical field is probably a part of this dipole
field. The field structure of the A0 dynamo-mode strikingly continues towards
the region near the GC. In short, the magnetic fields in the Galactic disk have
a bisymmetric spiral structure of primordial nature, while in the halo and near
the GC the A0 dynamo seems to dominate, so that the fields consist of toroidal
fields with opposite directions below and above the Galactic plane and poloidal
fields of dipole form.


  We formulate a set of general rules for computing $d$-dimensional four-point
global conformal blocks of operators in arbitrary Lorentz representations in
the context of the embedding space operator product expansion formalism
arXiv:1905.00434. With these rules, the procedure for determining any conformal
block of interest is reduced to (1) identifying the relevant projection
operators and tensor structures and (2) applying the conformal rules to obtain
the blocks. To facilitate the bookkeeping of contributing terms, we introduce a
convenient diagrammatic notation. We present several concrete examples to
illustrate the general procedure as well as to demonstrate and test the
explicit application of the rules. In particular, we consider four-point
functions involving scalars $S$ and some specific irreducible representations
$R$, namely $\langle SSSS\rangle$, $\langle SSSR\rangle$, $\langle SRSR\rangle$
and $\langle SSRR\rangle$ (where, when allowed, $R$ is a vector or a fermion),
and determine the corresponding blocks for all possible exchanged
representations.


  We consider the depletion of primordial deuterium in the interior of
substellar objects as a function of mass, age and absolute magnitude in several
photometric passbands. We characterize potential spectroscopic signatures of
deuterium in the lines of deuterated water HDO. These results will serve as a
useful, independent diagnostic to characterize the mass and/or the age of young
substellar objects, and to provide an independent age determination of very
young clusters. These results can serve to identify objects at the
deuterium-burning limit and to confront the theoretical prediction that
D-burning is a necessary condition to form star-like objects.


  We provide an algebraic description of the Teichm\"uller space and moduli
space of flat metrics on a closed manifold or orbifold and study its boundary,
which consists of (isometry classes of) flat orbifolds to which the original
object may collapse. It is also shown that every closed flat orbifold can be
obtained by collapsing closed flat manifolds, and the collapsed limits of
closed flat 3-manifolds are classified.


  EUSO-TA is a pathfinder experiment for the space based JEM-EUSO mission for
the detection of ultra-high energy cosmic rays. EUSO-TA is an high-resolution
fluorescence telescope installed in front of the Black Rock Mesa fluorescence
detectors of the Telescope Array (TA) experiment, in Utah (USA). At the TA
site, a Central Laser Facility is installed for calibration purposes, since it
emits laser beams with known energy and geometry. EUSO-TA consists of two 1
$\mbox{m}^2$ Fresnel lenses, with a field of view of 10.5{\deg} that focus the
light on a Photo Detector Module (PDM). The PDM currently consists of 36
Hamamatsu Multi-Anode Photo-Multipliers Tubes (MAPMTs) with 64 channels each.
Front-end readout is performed by 36 ASICS, with two FPGA boards that send the
data to a CPU and a storage system. The detector was installed in February
2015. Tests using the mentioned light sources have been performed and
observations of cosmic ray events, as well as those of stars with different
magnitude and color index have been done. The data acquisition is triggered by
TA fluorescence detectors, although a self-trigger algorithm is currently in
the last phases of development and test. With TA, thanks to its large field of
view and the surface detectors, the cosmic ray shower events are reconstructed
and the parameters are used to perform simulations of the response of EUSO-TA
detector using EUSO-Offline. Simulations of the detected events are compared
with data and the results are shown in this work.


  The action of any local operator on a quantum system propagates through the
system carrying the information of the operator. This is usually studied via
the out-of-time-order correlator (OTOC). We numerically study the information
propagation from one end of a periodically driven spin-1/2 $XY$ chain with open
boundary conditions using the Floquet infinite-temperature OTOC. We calculate
the OTOC for two different spin operators, $\sigma^x$ and $\sigma^z$. For
sinusoidal driving, the model can be shown to host different types of edge
states, namely, topological (Majorana) edge states and non-topological edge
states. We observe a localization of information at the edge for both
$\sigma^z$ and $\sigma^x$ OTOCs whenever edge states are present. In addition,
in the case of non-topological edge states, we see oscillations of the OTOC in
time near the edge, the oscillation period being inversely proportional to the
gap between the Floquet eigenvalues of the edge states. We provide an
analytical understanding of these effects due to the edge states. It was known
earlier that the OTOC for the spin operator which is local in terms of
Jordan-Wigner fermions ($\sigma^z$) shows no signature of information
scrambling inside the light cone of propagation, while the OTOC for the spin
operator which is non-local in terms of Jordan-Wigner fermions ($\sigma^x$)
shows signatures of scrambling. We report a remarkable `unscrambling effect' in
the $\sigma^x$ OTOC after reflections from the ends of the system. Finally, we
demonstrate that the information propagates into the system mainly via the bulk
states with the maximum value of the group velocity, and we show how this
velocity is controlled by the driving frequency and amplitude.


  We present a 3D semi-analytic model of self-gravitating discs, and include a
prescription for dust trapping in the disc spiral arms. Using Monte-Carlo
radiative transfer we produce synthetic ALMA observations of these discs. In
doing so we demonstrate that our model is capable of producing observational
predictions, and able to model real image data of potentially self-gravitating
discs. For a disc to generate spiral structure that would be observable with
ALMA requires that the disc's dust mass budget is dominated by millimetre and
centimetre-sized grains. Discs in which grains have grown to the grain
fragmentation threshold may satisfy this criterion, thus we predict that
signatures of gravitational instability may be detectable in discs of lower
mass than has previously been suggested. For example, we find that discs with
disc-to-star mass ratios as low as $0.10$ are capable of driving observable
spiral arms. Substructure becomes challenging to detect in discs where no grain
growth has occurred or in which grain growth has proceeded well beyond the
grain fragmentation threshold. We demonstrate how we can use our model to
retrieve information about dust trapping and grain growth through
multi-wavelength observations of discs, and using estimates of the opacity
spectral index. Applying our disc model to the Elias 27, WaOph 6 and IM Lup
systems we find gravitational instability to be a plausible explanation for the
observed substructure in all 3 discs, if sufficient grain growth has indeed
occurred.


  The Landau-Selberg-Delange method provides an asymptotic formula for the
partial sums of a multiplicative function whose average value on primes is a
fixed complex number $v$. The shape of this asymptotic implies that $f$ can get
very small on average only if $v=0,-1,-2,\dots$. Moreover, if $v<0$, then the
Dirichlet series associated to $f$ must have a zero of multiplicity $-v$ at
$s=1$. In this paper, we prove a converse result that shows that if $f$ is a
multiplicative function that is bounded by a suitable divisor function, and $f$
has very small partial sums, then there must be finitely many real numbers
$\gamma_1$, $\dots$, $\gamma_m$ such that $f(p)\approx
-p^{i\gamma_1}-\cdots-p^{-i\gamma_m}$ on average. The numbers $\gamma_j$
correspond to ordinates of zeroes of the Dirichlet series associated to $f$,
counted with multiplicity. This generalizes a result of the first author, who
handled the case when $|f|\le 1$ in previous work.


  We report the observation of tunneling anisotropic magnetoresistance effect
(TAMR) in the epitaxial metal-semiconductor system Fe/GaAs/Au. The observed
two-fold anisotropy of the resistance can be switched by reversing the bias
voltage, suggesting that the effect originates from the interference of the
spin-orbit coupling at the interfaces. Corresponding model calculations
reproduce the experimental findings very well.


  The Chern-Fulton class is a generalization of Chern class to the realm of
arbitrary embeddable schemes. While Chern-Fulton classes are sensitive to
non-reduced scheme structure, they are not sensitive to possible singularities
of the underlying support, thus at first glance are not interesting from a
singularity theory viewpoint. However, we introduce a class of formal objects
which we think of as `fractional schemes', or f-schemes for short, and then
show that when one broadens the domain of Chern-Fulton classes to f-schemes one
may indeed recover singularity invariants of varieties and schemes. More
precisely, we show that for almost all global complete intersections, their
Chern-Schwartz-Macpherson classes may be computed via Chern-Fulton classes of
f-schemes.


  We consider the numerical simulation of Hamiltonian systems of ordinary
differential equations. Two features of Hamiltonian systems are that energy is
conserved along trajectories and phase space volume is preserved by the flow.
We want to determine if there are integration schemes that preserve these two
properties for all Hamiltonian systems, or at least for all systems in a wide
class. This paper provides provides a negative result in the case of two
dimensional (one degree of freedom) Hamiltonian systems, for which phase space
volume is identical to area. Our main theorem shows that there are no
computationally reasonable numerical integrators for which all Hamiltonian
systems of one degree of freedom can be integrated while conserving both area
and energy. Before proving this result we define what we mean by a
computationally reasonable integrator. We then consider what obstructions this
result places on the existence of volume- and energy-conserving integrators for
Hamiltonian systems with an arbitrary number of degrees of freedom.


  The Kepler mission has revealed that Earth-sized planets are common, and
dozens have been discovered to orbit in or near their host star's habitable
zone. A major focus in astronomy is to determine which of these exoplanets are
likely to have Earth-like properties that are amenable to follow-up with both
ground- and future space-based surveys, with an ultimate goal of probing their
atmospheres to look for signs of life. Venus-like atmospheres will be of
particular interest in these surveys. While Earth and Venus evolved to have
similar sizes and densities, it remains unclear what factors led to the
dramatic divergence of their atmospheres. Studying analogs to both Earth and
Venus can thus shed light on the limits of habitability and the potential for
life on known exoplanets. Here we present the discovery and confirmation of
Kepler-1649b, an Earth-sized planet orbiting a nearby M5V star that receives
incident flux at a level similar to that of Venus. We present our methods for
characterizing the star, using a combination of PSF photometry, ground-based
spectroscopy and imaging, to confirm the planetary nature of Kepler-1649b.
Planets like Kepler-1649b will be prime candidates for atmospheric and
habitability studies in the next generation of space missions.


  In this paper, we employ spatial econometric methods to analyze panel data
from German NUTS 3 regions. Our goal is to gain a deeper understanding of the
significance and interdependence of industry clusters in shaping the dynamics
of GDP. To achieve a more nuanced spatial differentiation, we introduce
indicator matrices for each industry sector which allows for extending the
spatial Durbin model to a new version of it. This approach is essential due to
both the economic importance of these sectors and the potential issue of
omitted variables. Failing to account for industry sectors can lead to omitted
variable bias and estimation problems. To assess the effects of the major
industry sectors, we incorporate eight distinct branches of industry into our
analysis. According to prevailing economic theory, these clusters should have a
positive impact on the regions they are associated with. Our findings indeed
reveal highly significant impacts, which can be either positive or negative, of
specific sectors on local GDP growth. Spatially, we observe that direct and
indirect effects can exhibit opposite signs, indicative of heightened
competitiveness within and between industry sectors. Therefore, we recommend
that industry sectors should be taken into consideration when conducting
spatial analysis of GDP. Doing so allows for a more comprehensive understanding
of the economic dynamics at play.


  We discuss Coleman's theorem concerning the energy density of the ground
state of the sine-Gordon model proved in Phys. Rev. D 11, 2088 (1975).
According to this theorem the energy density of the ground state of the
sine-Gordon model should be unbounded from below for coupling constants beta^2
> 8 pi. The consequence of this theorem would be the non-existence of the
quantum ground state of the sine-Gordon model for beta^2 > 8 pi. We show that
the energy density of the ground state in the sine-Gordon model is bounded from
below even for beta^2 > 8 pi. This result is discussed in relation to Coleman's
theorem (Comm. Math. Phys. 31, 259 (1973)), particle mass spectra and
soliton-soliton scattering in the sine-Gordon model.


  We propose a novel algorithm for unsupervised extraction of piecewise planar
models from depth-data. Among other applications, such models are a good way of
enabling autonomous agents (robots, cars, drones, etc.) to effectively perceive
their surroundings and to navigate in three dimensions. We propose to do this
by fitting the data with a piecewise-linear Gaussian mixture regression model
whose components are skewed over planes, making them flat in appearance rather
than being ellipsoidal, by embedding an outlier-trimming process that is
formally incorporated into the proposed expectation-maximization algorithm, and
by selectively fusing contiguous, coplanar components. Part of our motivation
is an attempt to estimate more accurate plane-extraction by allowing each model
component to make use of all available data through probabilistic clustering.
The algorithm is thoroughly evaluated against a standard benchmark and is shown
to rank among the best of the existing state-of-the-art methods.


  Second-order tensor modes induced by nonlinear gravity are a key component of
the cosmological background of gravitational waves. A detection of this
background would allow us to probe the primordial power spectrum at otherwise
inaccessible scales. Usually, the energy density of these gravitational waves
is studied within perturbation theory in a particular gauge -- a connection
between our physical spacetime and a fictitious background. It is a widely
recognized issue that the second-order, scalar-induced gravitational waves are
gauge dependent. This issue arises because they are not well-defined as tensors
in the physical spacetime at second-order and are thus unphysical. In this
paper, we propose the covariant transverse-traceless projection of the
extrinsic curvature to study cosmological gravitational waves on a spatial
hypersurface. We define a new energy density which is based purely on spacetime
tensors, independent of perturbation theory, and thus is gauge invariant by
definition. We show that, in the context of second-order perturbation theory,
this new energy density contains only propagating modes in the constant-time
hypersurface in the Newtonian gauge. We further show that we can recover the
same gravitational waves after a transformation to the synchronous gauge, so
long as we correctly identify the Newtonian hypersurface.


  VALAN is a lightweight and scalable software framework for deep reinforcement
learning based on the SEED RL architecture. The framework facilitates the
development and evaluation of embodied agents for solving grounded language
understanding tasks, such as Vision-and-Language Navigation and
Vision-and-Dialog Navigation, in photo-realistic environments, such as
Matterport3D and Google StreetView. We have added a minimal set of abstractions
on top of SEED RL allowing us to generalize the architecture to solve a variety
of other RL problems. In this article, we will describe VALAN's software
abstraction and architecture, and also present an example of using VALAN to
design agents for instruction-conditioned indoor navigation.


  Using a nested coset construction a collection of D-branes that appear to
generate all the K-theory charges of string theory on SU(n) are constructed and
their charges are determined.


  Graph Burning asks, given a graph $G = (V,E)$ and an integer $k$, whether
there exists $(b_{0},\dots,b_{k-1}) \in V^{k}$ such that every vertex in $G$
has distance at most $i$ from some $b_{i}$. This problem is known to be
NP-complete even on connected caterpillars of maximum degree $3$. We study the
parameterized complexity of this problem and answer all questions arose by Kare
and Reddy [IWOCA 2019] about parameterized complexity of the problem. We show
that the problem is W[2]-complete parameterized by $k$ and that it does no
admit a polynomial kernel parameterized by vertex cover number unless
$\mathrm{NP} \subseteq \mathrm{coNP/poly}$. We also show that the problem is
fixed-parameter tractable parameterized by clique-width plus the maximum
diameter among all connected components. This implies the fixed-parameter
tractability parameterized by modular-width, by treedepth, and by distance to
cographs. Although the parameterization by distance to split graphs cannot be
handled with the clique-width argument, we show that this is also tractable by
a reduction to a generalized problem with a smaller solution size.


  One loop field theory calculations of free energies quite often yield
violations of the stability conditions associated with the thermodynamic second
law. Perhaps the best known example involves the equation of state of black
holes. Here, it is pointed out that the Casimir force between two parallel
conducting plates also violates a thermodynamic stability condition normally
associated with the second law of thermodynamics.


  We have computed a series of realistic and self-consistent models that
reproduce the properties of HII galaxies.
  The emitted spectrum of HII galaxies is reproduced by means of the
photoionization code CLOUDY, using as ionizing spectrum the spectral energy
distribution of the modelled HII galaxy, calculated using new and updated
stellar population synthesis model (PopStar, Molla et al. 08) This, in turn, is
calculated according to a star formation history and a metallicity evolution
given by a chemical evolution code. Our technique reproduces observed
abundances, diagnostic diagrams, colours and equivalent width vs. colour
relations for local HII galaxies


  Most image captioning models following an autoregressive manner suffer from
significant inference latency. Several models adopted a non-autoregressive
manner to speed up the process. However, the vanilla non-autoregressive manner
results in subpar performance, since it generates all words simultaneously,
which fails to capture the relationships between words in a description. The
semi-autoregressive manner employs a partially parallel method to preserve
performance, but it sacrifices inference speed. In this paper, we introduce a
fast and flexible framework for image captioning called BoFiCap based on
bounding and filling techniques. The BoFiCap model leverages the inherent
characteristics of image captioning tasks to pre-define bounding boxes for
image regions and their relationships. Subsequently, the BoFiCap model fills
corresponding words in each box using two-generation manners. Leveraging the
box hints, our filling process allows each word to better perceive other words.
Additionally, our model offers flexible image description generation: 1) by
employing different generation manners based on speed or performance
requirements, 2) producing varied sentences based on user-specified boxes.
Experimental evaluations on the MS-COCO benchmark dataset demonstrate that our
framework in a non-autoregressive manner achieves the state-of-the-art on
task-specific metric CIDEr (125.6) while speeding up 9.22x than the baseline
model with an autoregressive manner; in a semi-autoregressive manner, our
method reaches 128.4 on CIDEr while a 3.69x speedup. Our code and data is
available at https://github.com/ChangxinWang/BoFiCap.


  We reconsider the issue of proving large scale spatial homogeneity of the
universe, given isotropic observations about us and the possibility of source
evolution both in numbers and luminosities. Two theorems make precise the
freedom available in constructing cosmological models that will fit the
observations. They make quite clear that homogeneity cannot be proven without
either a fully determinate theory of source evolution, or availability of
distance measures that are independent of source evolution. We contrast this
goal with the standard approach that assumes spatial homogeneity a priori, and
determines source evolution functions on the basis of this assumption.


  We show the existence of abelian surfaces $A$ over $\mathbb{Q}_p$ having good
reduction with supersingular special fibre whose associated $p$-adic Galois
module $V_p(A)$ is not semisimple.


  We study the distribution of prime chains, which are sequences p_1,...,p_k of
primes for which p_{j+1}\equiv 1\pmod{p_j} for each j. We give estimates for
the number of chains with p_k\le x (k variable), and the number of chains with
p_1=p and p_k \le px. The majority of the paper concerns the distribution of
H(p), the length of the longest chain with p_k=p, which is also the height of
the Pratt tree for p. We show H(p)\ge c\log\log p and H(p)\le (\log p)^{1-c'}
for almost all p, with c,c' explicit positive constants. We can take, for any
\epsilon>0, c=e-\epsilon assuming the Elliott-Halberstam conjecture. A
stochastic model of the Pratt tree, based on a branching random walk, is
introduced and analyzed. The model suggests that for most p, H(p) stays very
close to e \log\log p.


  We present a new tensor network algorithm for calculating the partition
function of interacting quantum field theories in 2 dimensions. It is based on
the Tensor Renormalization Group (TRG) protocol, adapted to operate entirely at
the level of fields. This strategy was applied in Ref.[1] to the much simpler
case of a free boson, obtaining an excellent performance. Here we include an
arbitrary self-interaction and treat it in the context of perturbation theory.
A real space analogue of the Wilsonian effective action and its expansion in
Feynman graphs is proposed. Using a $\lambda \phi^4$ theory for benchmark, we
evaluate the order $\lambda$ correction to the free energy. The results show a
fast convergence with the bond dimension, implying that our algorithm captures
well the effect of interaction on entanglement.


  The evolution of the galaxy stellar mass function is especially useful to
test the current model of galaxy formation. Observational data have revealed a
few inconsistencies with predictions from the $\Lambda {\rm CDM}$ model. For
example, most massive galaxies have already been observed at very high
redshifts, and they have experienced only mild evolution since then. In
conflict with this, semi-analytical models of galaxy formation predict an
insufficient number of massive galaxies at high redshift and a rapid evolution
between redshift 1 and 0 . In addition, there is a strong correlation between
star formation rate and stellar mass for star-forming galaxies, which can be
roughly reproduced with the model, but with a normalization that is too low at
high redshift. Furthermore, the stellar mass density obtained from the integral
of the cosmic star formation history is higher than the measured one by a
factor of 2. In this paper, we study these issues using a semi-analytical model
that includes: 1) cold gas accretion in massive halos at high redshift; 2)
tidal stripping of stellar mass from satellite galaxies; and 3) an evolving
stellar initial mass function (bottom-light) with a higher gas recycle
fraction. Our results show that the combined effects from 1) and 2) can predict
sufficiently massive galaxies at high redshifts and reproduce their mild
evolution at low redshift, While the combined effects of 1) and 3) can
reproduce the correlation between star formation rate and stellar mass for
star-forming galaxies across wide range of redshifts. A bottom-light/top-heavy
stellar IMF could partly resolve the conflict between the stellar mass density
and cosmic star formation history.


  We derive a Gaussian approximation result for the maximum of a sum of
high-dimensional random vectors. Specifically, we establish conditions under
which the distribution of the maximum is approximated by that of the maximum of
a sum of the Gaussian random vectors with the same covariance matrices as the
original vectors. This result applies when the dimension of random vectors
($p$) is large compared to the sample size ($n$); in fact, $p$ can be much
larger than $n$, without restricting correlations of the coordinates of these
vectors. We also show that the distribution of the maximum of a sum of the
random vectors with unknown covariance matrices can be consistently estimated
by the distribution of the maximum of a sum of the conditional Gaussian random
vectors obtained by multiplying the original vectors with i.i.d. Gaussian
multipliers. This is the Gaussian multiplier (or wild) bootstrap procedure.
Here too, $p$ can be large or even much larger than $n$. These distributional
approximations, either Gaussian or conditional Gaussian, yield a high-quality
approximation to the distribution of the original maximum, often with
approximation error decreasing polynomially in the sample size, and hence are
of interest in many applications. We demonstrate how our Gaussian
approximations and the multiplier bootstrap can be used for modern
high-dimensional estimation, multiple hypothesis testing, and adaptive
specification testing. All these results contain nonasymptotic bounds on
approximation errors.


  Combination of deep learning and ab initio calculation has shown great
promise in revolutionizing future scientific research, but how to design neural
network models incorporating a priori knowledge and symmetry requirements is a
key challenging subject. Here we propose an E(3)-equivariant deep-learning
framework to represent density functional theory (DFT) Hamiltonian as a
function of material structure, which can naturally preserve the Euclidean
symmetry even in the presence of spin-orbit coupling. Our DeepH-E3 method
enables very efficient electronic-structure calculation at ab initio accuracy
by learning from DFT data of small-sized structures, making routine study of
large-scale supercells ($> 10^4$ atoms) feasible. Remarkably, the method can
reach sub-meV prediction accuracy at high training efficiency, showing
state-of-the-art performance in our experiments. The work is not only of
general significance to deep-learning method development, but also creates new
opportunities for materials research, such as building Moir\'e-twisted material
database.


  Recently, spectral CT has been drawing a lot of attention in a variety of
clinical applications primarily due to its capability of providing quantitative
information about material properties. The quantitative integrity of the
reconstructed data depends on the accuracy of the data corrections applied to
the measurements. Scatter correction is a particularly sensitive correction in
spectral CT as it depends on system effects as well as the object being imaged
and any residual scatter is amplified during the non-linear material
decomposition. An accurate way of removing scatter is subtracting the scatter
estimated by Monte Carlo simulation. However, to get sufficiently good scatter
estimates, extremely large numbers of photons is required, which may lead to
unexpectedly high computational costs. Other approaches model scatter as a
convolution operation using kernels derived using empirical methods. These
techniques have been found to be insufficient in spectral CT due to their
inability to sufficiently capture object dependence. In this work, we develop a
deep residual learning framework to address both issues of computation
simplicity and object dependency. A deep convolution neural network is trained
to determine the scatter distribution from the projection content in training
sets. In test cases of a digital anthropomorphic phantom and real water
phantom, we demonstrate that with much lower computing costs, the proposed
network provides sufficiently accurate scatter estimation.


  We consider the XXX spin-$\frac{1}{2}$ Heisenberg chain on the circle with an
arbitrary twist. We characterize its spectral problem using the modified
algebraic Bethe anstaz and study the scalar product between the Bethe vector
and its dual. We obtain modified Slavnov and Gaudin-Korepin formulas for the
model. Thus we provide a first example of such formulas for quantum integrable
models without ${\rm U}(1)$ symmetry characterized by an inhomogenous Baxter
T-Q equation.


  We consider the Schr{\"o}dinger equation with a nondispersive logarithmic
nonlinearity and a repulsive harmonic potential. For a suitable range of the
coefficients, there exist two positive stationary solutions, each one
generating a continuous family of solitary waves. These solutions are Gaussian,
and turn out to be orbitally unstable. We also discuss the notion of ground
state in this setting: for any natural definition, the set of ground states is
empty.


  In Alonso et al., JHEP 12 (2014) 034, the CP-even sector of the effective
chiral Lagrangian for a generic composite Higgs model with a symmetric coset
has been constructed, up to four momenta. In this paper, the CP-odd couplings
are studied within the same context. If only the Standard Model bosonic sources
of custodial symmetry breaking are considered, then at most six independent
operators form a basis. One of them is the weak-$\theta$ term linked to
non-perturbative sources of CP viola- tion, while the others describe CP-odd
perturbative couplings between the Standard Model gauge bosons and an
Higgs-like scalar belonging to the Goldstone boson sector. The procedure is
then applied to three distinct exemplifying frameworks: the original
$SU(5)/SO(5)$ Georgi-Kaplan model, the minimal custodial-preserving
$SO(5)/SO(4)$ model and the minimal $SU(3)/(SU(2)\times U(1))$ model, which
intrinsically breaks cus- todial symmetry. Moreover, the projection of the
high-energy electroweak effective theory to the low-energy chiral effective
Lagrangian for a dynamical Higgs is per- formed, uncovering strong relations
between the operator coefficients and pinpointing the differences with the
elementary Higgs scenario.


  Although face recognition starts to play an important role in our daily life,
we need to pay attention that data-driven face recognition vision systems are
vulnerable to adversarial attacks. However, the current two categories of
adversarial attacks, namely digital attacks and physical attacks both have
drawbacks, with the former ones impractical and the latter one conspicuous,
high-computational and inexecutable. To address the issues, we propose a
practical, executable, inconspicuous and low computational adversarial attack
based on LED illumination modulation. To fool the systems, the proposed attack
generates imperceptible luminance changes to human eyes through fast intensity
modulation of scene LED illumination and uses the rolling shutter effect of
CMOS image sensors in face recognition systems to implant luminance information
perturbation to the captured face images. In summary,we present a
denial-of-service (DoS) attack for face detection and a dodging attack for face
verification. We also evaluate their effectiveness against well-known face
detection models, Dlib, MTCNN and RetinaFace , and face verification models,
Dlib, FaceNet,and ArcFace.The extensive experiments show that the success rates
of DoS attacks against face detection models reach 97.67%, 100%, and 100%,
respectively, and the success rates of dodging attacks against all face
verification models reach 100%.


  Optical birefringence and light absorption measurements reveal four regimes
for the thermotropic behavior of a nematogen liquid (7CB) upon sequential
filling of parallel-aligned capillaries of 12 nm diameter in a monolithic,
mesoporous silica membrane. No molecular reorientation is observed for the
first adsorbed monolayer. In the film-condensed state (up to 1 nm thickness) a
weak, continuous paranematic-to-nematic (P-N) transition is found, which is
shifted by 10 K below the discontinuous bulk transition at T_IN=305K. The
capillary-condensed state exhibits a more pronounced, albeit still continuous
P-N reordering, located 4 K below T_IN. This shift vanishes abruptly on
complete filling of the capillaries, which we tentatively trace to a 10 MPa
tensile pressure release associated with the disappearance of concave menisci
in the confined liquid.


  The objective of this report is to present a list of proceedings
(conferences, workshops, symposia, meetings) in the areas of Computer Science,
Electrical & Electronic Engineering, and Communications covered by Google
Scholar Metrics and ranked according to their h-index. Google Scholar Metrics
only displays publications that have published at least 100 papers and have
received at least one citation in the last five years (2009-2013). The searches
were conducted between the 15th and 22nd of December, 2014. A total of 1208
proceedings have been identified


  Molecular dynamics (MD) simulations of the zeta potential are so poor that it
has become common to term their predictions 'apparent'. Here we demonstrate how
zeta potentials that agree with measured values can be calculated by: (1)
integrating the net average charge in surface-parallel layers from the midpoint
of the fluid layer (where the electrostatic potential is zero) to and then into
two solid caps, (2) determining the position of slipping plane with separate
Couette flow models, and (3) calculating the charge distribution and
electrostatic potential under static conditions. The solids we model are charge
neutral surfaces composed of atoms with zero charge or charge balanced
monovalent or divalent ions. The zeta potentials calculated are within a few
millivolts of measured values, and the measured values fall within the
simulation error bars. Insights provided by the improved MD simulations into
the complex phenomena that affect surface charge and zeta potential are
discussed.


  We approach non-divisorial base loci of big and nef line bundles on
irreducible symplectic varieties. While for K3 surfaces, only divisorial base
loci can occur, nothing was known about the behaviour of non-divisorial base
loci for more general irreducible symplectic varieties. We determine the base
loci of all big and nef line bundles on the Hilbert scheme of two points on
very general K3 surfaces of genus two and on their birational models.
Remarkably, we find an ample line bundle with a non-trivial base locus in
codimension two. We deduce that, generically in the moduli spaces of polarized
K3$^{[2]}$-type varieties, the polarization is base point free.


  Self-Supervised Learning (SSL) is a new paradigm for learning discriminative
representations without labelled data and has reached comparable or even
state-of-the-art results in comparison to supervised counterparts. Contrastive
Learning (CL) is one of the most well-known approaches in SSL that attempts to
learn general, informative representations of data. CL methods have been mostly
developed for applications in computer vision and natural language processing
where only a single sensor modality is used. A majority of pervasive computing
applications, however, exploit data from a range of different sensor
modalities. While existing CL methods are limited to learning from one or two
data sources, we propose COCOA (Cross mOdality COntrastive leArning), a
self-supervised model that employs a novel objective function to learn quality
representations from multisensor data by computing the cross-correlation
between different data modalities and minimizing the similarity between
irrelevant instances. We evaluate the effectiveness of COCOA against eight
recently introduced state-of-the-art self-supervised models, and two supervised
baselines across five public datasets. We show that COCOA achieves superior
classification performance to all other approaches. Also, COCOA is far more
label-efficient than the other baselines including the fully supervised model
using only one-tenth of available labelled data.


  In this work, we present a detailed photophysical analysis of
recently-discovered optically stable, single photon emitters (SPEs) in Gallium
Nitride (GaN). Temperature-resolved photoluminescence measurements reveal that
the emission lines at 4 K are three orders of magnitude broader than the
transform-limited widths expected from excited state lifetime measurements. The
broadening is ascribed to ultra-fast spectral diffusion. Continuing the
photophysics study on several emitters at room temperature (RT), a maximum
average brightness of ~427 kCounts/s is measured. Furthermore, by determining
the decay rates of emitters undergoing three-level optical transitions,
radiative and non-radiative lifetimes are calculated at RT. Finally,
polarization measurements from 14 emitters are used to determine visibility as
well as dipole orientation of defect systems within the GaN crystal. Our
results underpin some of the fundamental properties of SPE in GaN both at
cryogenic and RT, and define the benchmark for future work in GaN-based
single-photon technologies.


  The QCD axion and an axion-like particle (ALP) are compelling candidates of
dark matter. For the QCD axion, it is known that when the Peccei-Quinn (PQ)
symmetry is spontaneously broken after inflation, the large initial fluctuation
can lead to axion clump formation. On the other hand, when the symmetry is
already broken during inflation, it has been believed that the axion clump
formation does not occur due to the small amplitude of the initial axion
fluctuation. We revisit this prevailing understanding, considering both the QCD
axion and an ALP. We find that for the QCD axion, the clump formation does not
occur even if we consider an extremely fine-tuned initial condition. Meanwhile,
it turns out that for an ALP which allows a more general potential form, the
clump formation can take place through the tachyonic instability or/and the
resonance instability, considering a multiple cosine potential.


  Power-law-distributed species counts or clone counts arise in many biological
settings such as multispecies cell populations, population genetics, and
ecology. This empirical observation that the number of species $c_{k}$
represented by $k$ individuals scales as negative powers of $k$ is also
supported by a series of theoretical birth-death-immigration (BDI) models that
consistently predict many low-population species, a few intermediate-population
species, and very high-population species. However, we show how a simple global
population-dependent regulation in a neutral BDI model destroys the power law
distributions. Simulation of the regulated BDI model shows a high probability
of observing a high-population species that dominates the total population.
Further analysis reveals that the origin of this breakdown is associated with
the failure of a mean-field approximation for the expected species abundance
distribution. We find an accurate estimate for the expected distribution
$\langle c_k \rangle$ by mapping the problem to a lower-dimensional Moran
process, allowing us to also straightforwardly calculate the covariances
$\langle c_k c_\ell \rangle$. Finally, we exploit the concepts associated with
energy landscapes to explain the failure of the mean-field assumption by
identifying a phase transition in the quasi-steady-state species counts
triggered by a decreasing immigration rate.


  Route & Wolszczan (2016) recently detected five radio bursts from the T6
dwarf WISEP J112254.73+255021.5 and used the timing of these events to propose
that this object rotates with an ultra-short period of ~17.3 minutes. We
conducted follow-up observations with the Very Large Array and Gemini-North but
found no evidence for this periodicity. We do, however, observe variable,
highly circularly polarized radio emission possibly with a period of 116
minutes, although our observation lasted only 162 minutes and so more data are
needed to confirm it. Our proposed periodicity is typical of other radio-active
ultracool dwarfs. The handedness of the circular polarization alternates with
time and there is no evidence for any unpolarized emission component, the first
time such a phenomenology has been observed in radio studies of very low-mass
stars and brown dwarfs. We suggest that the object's magnetic dipole axis may
be highly misaligned relative to its rotation axis.


  This paper analyzes the evolution of Keynesianism making use of concepts
offered by Imre Lakatos. The Keynesian "hard core" lies in its views regarding
the instability of the market economy, its "protective belt" in the policy
strategy for macroeconomic stabilization using fiscal policy and monetary
policy. Keynesianism developed as a policy program to counter classical
liberalism, which attributes priority to the autonomy of the market economy and
tries to limit the role of government. In general, the core of every policy
program consists in an unfalsifiable worldview and a value judgment that remain
unchanged. On the other hand, a policy strategy with a protective belt
inevitably evolves owing to changes in reality and advances in scientific
knowledge. This is why the Keynesian policy strategy has shifted from being
fiscal-led to one that is monetary-led because of the influence of monetarism;
further, the Great Recession has even led to their integration.


  Near the surface of any neutron star there is a thin heat blanketing envelope
that produces substantial thermal insulation of warm neutron star interiors and
that relates the internal temperature of the star to its effective surface
temperature. Physical processes in the blanketing envelopes are reasonably
clear but the chemical composition is not. The latter circumstance complicates
inferring physical parameters of matter in the stellar interiors from
observations of the thermal surface radiation of the stars and urges one to
elaborate the models of blanketing envelopes. We outline physical properties of
these envelopes, particularly, the equation of state, thermal conduction, ion
diffusion and others. Various models of heat blankets are reviewed, such as
composed of separate layers of different elements, or containing diffusive
binary ion mixtures in or out of diffusion equilibrium. The effects of strong
magnetic fields in the envelopes are outlined as well as the effects of high
temperatures which induce strong neutrino emission in the envelopes themselves.
Finally, we discuss how the properties of the heat blankets affect thermal
evolution of neutron stars and the ability to infer important information on
internal structure of neutron stars from observations.


  The current state of electronic component miniaturization coupled with the
increasing efficiency in hardware and software allow the development of smaller
and compact robotic systems. The convenience of using these small, simple, yet
capable robots has gathered the research community's attention towards
practical applications of swarm robotics. This paper presents the design of a
novel platform for swarm robotics applications that is low cost, easy to
assemble using off-the-shelf components, and deeply integrated with the most
used robotic framework available today: ROS (Robot Operating System). The
robotic platform is entirely open, composed of a 3D printed body and
open-source software. We describe its architecture, present its main features,
and evaluate its functionalities executing experiments using a couple of
robots. Results demonstrate that the proposed mobile robot is very effective
given its small size and reduced cost, being suitable for swarm robotics
research and education.


  The separation of training and data transmission as well as the frequent
uplink/downlink (UL/DL) switching make time-division duplex (TDD)-based massive
multiple-input multiple-output (mMIMO) systems less competent in fast
time-varying scenarios due to the resulted severe channel aging. To this end, a
multicarrier-division duplex (MDD) mMIMO scheme associated with two types of
well-designed frame structures are introduced for combating channel aging when
communicating over fast time-varying channels. To compare with TDD, the
corresponding frame structures related to 3GPP standards and their variant
forms are presented. The MDD-specific general Wiener predictor and
decision-directed Wiener predictor are introduced to predict the channel state
information, respectively, in the time domain based on UL pilots and in the
frequency domain based on the detected UL data, considering the impact of
residual self-interference (SI). Moreover, by applying the zero-forcing
precoding and maximum ratio combining, the closed-form approximations for the
lower bounded rate achieved by TDD and MDD systems over time-varying channels
are derived. Our main conclusion from this study is that the MDD, endowed with
the capability of full-duplex but less demand on SI cancellation than in-band
full-duplex (IBFD), outperforms both the conventional TDD and IBFD in combating
channel aging.


  The dynamics of amphiphilic films deposited on a solid surface is analyzed
for the case when shear oscillations of the solid surface are excited. The two
cases of surface- and bulk shear waves are studied with film exposed to gas or
to a liquid. By solving the corresponding dispersion equation and the wave
equation while maintaining the energy balance we are able to connect the
surface density and the shear viscocity of a fluid amphiphilic overlayer with
experimentally accessible damping coefficients, phase velocity, dissipation
factor and resonant frequency shifts of shear waves.


  A Pick function of $d$ variables is a holomorphic map from $\Pi^d$ to $\Pi$,
where $\Pi$ is the upper halfplane. Some Pick functions of one variable have an
asymptotic expansion at infinity, a power series $\sum_{n=1}^\infty \rho_n
z^{-n}$ with real numbers $\rho_n$ that gives an asymptotic expansion on
non-tangential approach regions to infinity. H. Hamburger in 1921 characterized
which sequences $\{\rho_n\} $ can occur. We give an extension of Hamburger's
results to Pick functions of two variables.


  Topological acoustics has recently witnessed a spurt in research activity,
owing to their unprecedented properties transcending typical wave phenomena. In
recent years, the use of coupled arrays of acoustic chambers has gained
popularity in designing topological acoustic systems. In their common form, an
array of acoustic chambers with relatively large volume is coupled via narrow
channels. Such configuration is generally modeled as a full three-dimensional
system, requiring extended computational time for simulating its harmonic
response. To this end, this paper establishes a comprehensive mathematical
treatment of the use of electroacoustic analogies for designing topological
acoustic lattices. The potential of such analytical approach is demonstrated
via two types of topological systems: (i) edge states with quantized winding
numbers in an acoustic diatomic lattice and (ii) valley Hall transition in an
acoustic honeycomb lattice that leads to robust waveguiding. In both cases, the
established analytical approach exhibits an excellent agreement with the full
three-dimensional model, whether in dispersion analyses or the response of an
acoustic system with a finite number of cells. The established analytical
framework is invaluable for designing a variety of acoustic topological
insulators with minimal computational cost.