  We study the ability of autonomous vehicles to improve the throughput of a
bottleneck using a fully decentralized control scheme in a mixed autonomy
setting. We consider the problem of improving the throughput of a scaled model
of the San Francisco-Oakland Bay Bridge: a two-stage bottleneck where four
lanes reduce to two and then reduce to one. Although there is extensive work
examining variants of bottleneck control in a centralized setting, there is
less study of the challenging multi-agent setting where the large number of
interacting AVs leads to significant optimization difficulties for
reinforcement learning methods. We apply multi-agent reinforcement algorithms
to this problem and demonstrate that significant improvements in bottleneck
throughput, from 20\% at a 5\% penetration rate to 33\% at a 40\% penetration
rate, can be achieved. We compare our results to a hand-designed feedback
controller and demonstrate that our results sharply outperform the feedback
controller despite extensive tuning. Additionally, we demonstrate that the
RL-based controllers adopt a robust strategy that works across penetration
rates whereas the feedback controllers degrade immediately upon penetration
rate variation. We investigate the feasibility of both action and observation
decentralization and demonstrate that effective strategies are possible using
purely local sensing. Finally, we open-source our code at
https://github.com/eugenevinitsky/decentralized_bottlenecks.


  Like many problems in AI in their general form, supervised learning is
computationally intractable. We hypothesize that an important reason humans can
learn highly complex and varied concepts, in spite of the computational
difficulty, is that they benefit tremendously from experienced and insightful
teachers. This paper proposes a new learning framework that provides a role for
a knowledgeable, benevolent teacher to guide the process of learning a target
concept in a series of "curricular" phases or rounds. In each round, the
teacher's role is to act as a moderator, exposing the learner to a subset of
the available training data to move it closer to mastering the target concept.
Via both theoretical and empirical evidence, we argue that this framework
enables simple, efficient learners to acquire very complex concepts from
examples. In particular, we provide multiple examples of concept classes that
are known to be unlearnable in the standard PAC setting along with provably
efficient algorithms for learning them in our extended setting. A key focus of
our work is the ability to learn complex concepts on top of simpler, previously
learned, concepts---a direction with the potential of creating more competent
artificial agents.


  The diffuse very high-energy (VHE, > 100 GeV) gamma-ray emission observed in
the central 200 pc of the Milky Way by H.E.S.S. was found to follow the dense
matter distribution in the Central Molecular Zone (CMZ) up to a longitudinal
distance of about 130 pc to the Galactic Centre (GC), where the flux rapidly
decreases. Recent sensitive H.E.S.S. analysis revealed that the cosmic-ray (CR)
density profile drops with the distance to the centre, making data compatible
with a steady cosmic PeVatron at the GC. In this paper, we extend this analysis
to obtain for the first time a detailed characterisation of the correlation
with matter and to search for additional features and individual gamma-ray
sources in the inner 200 pc. Taking advantage of 250 hours of H.E.S.S. data and
improved analysis techniques we perform a detailed morphology study of the
diffuse VHE emission observed from the GC ridge and reconstruct its total
spectrum. We show that the emission correlated with dense matter covers the
full CMZ and that its flux is about half the total diffuse emission flux. We
also detect some emission at higher latitude likely produced by hadronic
collisions of CRs in less dense regions of the GC interstellar medium. We
detect an additional emission component centred on the GC and extending over
about 15 pc that is consistent with the existence of a strong CR density
gradient and confirms the presence of a CR accelerator at the very centre of
our Galaxy. We show that the spectrum of the full ridge diffuse emission is
compatible with the one previously derived from the central regions, suggesting
that a single population of particles fills the entire CMZ. Finally, we report
the discovery of a VHE gamma-ray source near the GC radio arc and argue that it
is produced by the pulsar wind nebula candidate G0.13-0.11.


  We study the Small Ball Probabilities (SBPs) of Gaussian rough paths. While
many works on rough paths study the Large Deviations Principles (LDPs) for
stochastic processes driven by Gaussian rough paths, it is a noticeable gap in
the literature that SBPs have not been extended to the rough path framework.
  LDPs provide macroscopic information about a measure for establishing
Integrability type properties. SBPs provide microscopic information and are
used to establish a locally accurate approximation for a measure. Given the
compactness of a Reproducing Kernel Hilbert space (RKHS) ball, its metric
entropy provides invaluable information on how to approximate the law of a
Gaussian rough path.
  As an application, we are able to find upper and lower bounds for the rate of
convergence of an empirical rough Gaussian measure to its true law in
pathspace.


  It is well known that so called Breuer-Hall positive maps used in
entanglement theory are optimal. We show that these maps possess much more
subtle property --- they are exposed. As a byproduct it proves that a Robertson
map in the algebra of 4 x 4 complex matrices is not only extreme, which was
already shown by Robertson, but also exposed.


  Let $P(X)\in\mathbb{Z}[X]$ be an irreducible, monic, quartic polynomial with
cyclic or dihedral Galois group. We prove that there exists a constant $c_P>0$
such that for a positive proportion of integers $n$, $P(n)$ has a prime factor
$\ge n^{1+c_P}$.


  We study tiling and spectral sets in vector spaces over prime fields. The
classical Fuglede conjecture in locally compact abelian groups says that a set
is spectral if and only if it tiles by translation. This conjecture was
disproved by T. Tao in Euclidean spaces of dimensions 5 and higher, using
constructions over prime fields (in vector spaces over finite fields of prime
order) and lifting them to the Euclidean setting. Over prime fields, when the
dimension of the vector space is less than or equal to $2$ it has recently been
proven that the Fuglede conjecture holds (see \cite{IMP15}). In this paper we
study this question in higher dimensions over prime fields and provide some
results and counterexamples. In particular we prove the existence of spectral
sets which do not tile in $\mathbb{Z}_p^5$ for all odd primes $p$ and
$\mathbb{Z}_p^4$ for all odd primes $p$ such that $p \equiv 3 \text{ mod } 4$.
Although counterexamples in low dimensional groups over cyclic rings
$\mathbb{Z}_n$ were previously known they were usually for non prime $n$ or a
small, sporadic set of primes $p$ rather than general constructions. This paper
is a result of a Research Experience for Undergraduates program ran at the
University of Rochester during the summer of 2015 by A. Iosevich, J.
Pakianathan and G. Petridis.


  We give several sharp estimates for a class of combinations of second order
Riesz transforms on Lie groups ${G}={G}_{x} \times {G}_{y}$ that are multiply
connected, composed of a discrete abelian component ${G}_{x}$ and a connected
component ${G}_{y}$ endowed with a biinvariant measure. These estimates include
new sharp $L^p$ estimates via Choi type constants, depending upon the
multipliers of the operator. They also include weak-type, logarithmic and
exponential estimates. We give an optimal $L^q \to L^p$ estimate as well.
  It was shown recently by Arcozzi, Domelevo and Petermichl that such second
order Riesz transforms applied to a function may be written as conditional
expectation of a simple transformation of a stochastic integral associated with
the function.
  The proofs of our theorems combine this stochastic integral representation
with a number of deep estimates for pairs of martingales under strong
differential subordination by Choi, Banuelos and Osekowski.
  When two continuous directions are available, sharpness is shown via the
laminates technique. We show that sharpness is preserved in the discrete case
using Lax-Richtmyer theorem.


  We prove that there is no circulant Hadamard matrix $H$ with first row
$[h_{1},\ldots,h_{n}]$ of order $n>4$, under a condition about a sum of scalar
products of rows of two other circulant matrices of size $n/2$ associated to
$H.$


  We explore the enigmatic population of long-period, apparently non-recycled
pulsars in globular clusters, building on recent work by Boyles et al (2011).
This population is difficult to explain if it formed through typical core
collapse supernovae, leading many authors to invoke electron capture
supernovae. Where Boyles et al. dealt only with non-recycled pulsars in
clusters, we focus on the pulsars that originated in clusters but then escaped
into the field of the Galaxy due to the kicks they receive at birth. The
magnitude of the kick induced by electron capture supernovae is not well known,
so we explore various models for the kick velocity distribution and size of the
population. The most realistic models are those where the kick velocity is <~
10 km/s and where the number of pulsars scales with the luminosity of the
cluster (as a proxy for cluster mass). This is in good agreement with other
estimates of the electron capture supernovae kick velocity. We simulate a
number of large-area pulsar surveys to determine if a population of pulsars
originating in clusters could be identified as being separate from normal disk
pulsars. We find that the spatial and kinematical properties of the population
could be used, but only if large numbers of pulsars are detected. In fact, even
the most optimistic surveys carried out with the future Square Kilometer Array
are likely to detect < 10% of the total population, so the prospects for
identifying these as a separate group of pulsars are presently poor.


  The growing awareness of safety concerns in large language models (LLMs) has
sparked considerable interest in the evaluation of safety. This study
investigates an under-explored issue about the evaluation of LLMs, namely the
substantial discrepancy in performance between multiple-choice questions and
open-ended questions. Inspired by research on jailbreak attack patterns, we
argue this is caused by mismatched generalization. That is, LLM only remembers
the answer style for open-ended safety questions, which makes it unable to
solve other forms of safety tests. We refer to this phenomenon as fake
alignment and construct a comparative benchmark to empirically verify its
existence in LLMs. We introduce a Fake alIgNment Evaluation (FINE) framework
and two novel metrics--Consistency Score (CS) and Consistent Safety Score
(CSS), which jointly assess two complementary forms of evaluation to quantify
fake alignment and obtain corrected performance estimation. Applying FINE to 14
widely-used LLMs reveals several models with purported safety are poorly
aligned in practice. Subsequently, we found that multiple-choice format data
can also be used as high-quality contrast distillation-based fine-tuning data,
which can strongly improve the alignment consistency of LLMs with minimal
fine-tuning overhead. For data and code, see
https://github.com/AIFlames/Fake-Alignment.


  The purpose of this article is to develop a general parametric estimation
theory that allows the derivation of the limit distribution of estimators in
non-regular models where the true parameter value may lie on the boundary of
the parameter space or where even identifiability fails. For that, we propose a
more general local approximation of the parameter space (at the true value)
than previous studies. This estimation theory is comprehensive in that it can
handle penalized estimation as well as quasi-maximum likelihood estimation
under such non-regular models. Besides, our results can apply to the so-called
non-ergodic statistics, where the Fisher information is random in the limit,
including the regular experiment that is locally asymptotically mixed normal.
In penalized estimation, depending on the boundary constraint, even the Bridge
estimator with $q<1$ does not necessarily give selection consistency.
Therefore, some sufficient condition for selection consistency is described,
precisely evaluating the balance between the boundary constraint and the form
of the penalty. Examples handled in the paper are: (i) ML estimation of the
generalized inverse Gaussian distribution, (ii) quasi-ML estimation of the
diffusion parameter in a non-ergodic It\^o process whose parameter space
consists of positive semi-definite symmetric matrices, while the drift
parameter is treated as nuisance and (iii) penalized ML estimation of variance
components of random effects in linear mixed models.


  Dynamic community detection has been prospered as a powerful tool for
quantifying changes in dynamic brain network connectivity patterns by
identifying strongly connected sets of nodes. However, as the network science
problems and network data to be processed become gradually more sophisticated,
it awaits a better method to efficiently learn low dimensional representation
from dynamic network data and reveal its latent function that changes over time
in the brain network. In this work, an adversarial temporal graph
representation learning (ATGRL) framework is proposed to detect dynamic
communities from a small sample of brain network data. It adopts a novel
temporal graph attention network as an encoder to capture more efficient
spatio-temporal features by attention mechanism in both spatial and temporal
dimensions. In addition, the framework employs adversarial training to guide
the learning of temporal graph representation and optimize the measurable
modularity loss to maximize the modularity of community. Experiments on the
real-world brain networks datasets are demonstrated to show the effectiveness
of this new method.


  For the Schr\"odinger equation with a cubic-quintic, focusing-focusing
nonlinearity in one space dimension, this article proves the local asymptotic
completeness of the family of small standing solitary waves under even
perturbations in the energy space. For this model, perturbative of the
integrable cubic Schr\"odinger equation for small solutions, the linearized
equation around a small solitary wave has an internal mode, whose contribution
to the dynamics is handled by the Fermi golden rule.


  Named entity recognition (NER) models are typically based on the architecture
of Bi-directional LSTM (BiLSTM). The constraints of sequential nature and the
modeling of single input prevent the full utilization of global information
from larger scope, not only in the entire sentence, but also in the entire
document (dataset). In this paper, we address these two deficiencies and
propose a model augmented with hierarchical contextualized representation:
sentence-level representation and document-level representation. In
sentence-level, we take different contributions of words in a single sentence
into consideration to enhance the sentence representation learned from an
independent BiLSTM via label embedding attention mechanism. In document-level,
the key-value memory network is adopted to record the document-aware
information for each unique word which is sensitive to similarity of context
information. Our two-level hierarchical contextualized representations are
fused with each input token embedding and corresponding hidden state of BiLSTM,
respectively. The experimental results on three benchmark NER datasets
(CoNLL-2003 and Ontonotes 5.0 English datasets, CoNLL-2002 Spanish dataset)
show that we establish new state-of-the-art results.


  Using both numerical and analytical tools we study various features of
static, spherically symmetric solutions of the Einstein-Vlasov system. In
particular, we investigate the possible shapes of their mass-energy density and
find that they can be multi-peaked, we give numerical evidence and a partial
proof for the conjecture that the Buchdahl inequality $\sup_{r > 0} 2 m(r)/r <
8/9$, $m(r)$ the quasi-local mass, holds for all such steady states--both
isotropic {\em and} anisotropic--, and we give numerical evidence and a partial
proof for the conjecture that for any given microscopic equation of state--both
isotropic {\em and} anisotropic--the resulting one-parameter family of static
solutions generates a spiral in the radius-mass diagram.


  It is known that real Non-Gaussian stable distributions are unimodal, not
additive strongly unimodal, and multiplicative strongly unimodal in the
symmetric case. By a theorem of Cuculescu-Theodorescu, the only remaining
relevant situation for the multiplicative strong unimodality of stable laws is
the one-sided. In this paper, we show that positive $\alpha-$stable laws are
multiplicative strongly unimodal iff $\alpha\le 1/2.$


  Emotion recognition in social situations is a complex task that requires
integrating information from both facial expressions and the situational
context. While traditional approaches to automatic emotion recognition have
focused on decontextualized signals, recent research emphasizes the importance
of context in shaping emotion perceptions. This paper contributes to the
emerging field of context-based emotion recognition by leveraging psychological
theories of human emotion perception to inform the design of automated methods.
We propose an approach that combines emotion recognition methods with Bayesian
Cue Integration (BCI) to integrate emotion inferences from decontextualized
facial expressions and contextual knowledge inferred via Large-language Models.
We test this approach in the context of interpreting facial expressions during
a social task, the prisoner's dilemma. Our results provide clear support for
BCI across a range of automatic emotion recognition methods. The best automated
method achieved results comparable to human observers, suggesting the potential
for this approach to advance the field of affective computing.


  We developed dysarthric speech intelligibility classifiers on 551,176
disordered speech samples contributed by a diverse set of 468 speakers, with a
range of self-reported speaking disorders and rated for their overall
intelligibility on a five-point scale. We trained three models following
different deep learning approaches and evaluated them on ~94K utterances from
100 speakers. We further found the models to generalize well (without further
training) on the TORGO database (100% accuracy), UASpeech (0.93 correlation),
ALS-TDI PMP (0.81 AUC) datasets as well as on a dataset of realistic unprompted
speech we gathered (106 dysarthric and 76 control speakers,~2300 samples).


  Polarized dust emission outside of disks reveal the magnetic field morphology
of molecular clouds. Within disks, however, polarized dust emission can arise
from very different mechanisms (e.g., self-scattering), and each of them are
useful for constraining physical properties in the disk. For example, these
mechanisms allow us to constrain the disk grain size distributions and
grain/disk geometries, independent from current methods of measuring these
parameters. To accurately model these features and disentangle the various
polarization mechanisms, multiwavelength observations at very high resolution
and sensitivity are required. With significant upgrades to current
interferometric facilities, we can understand how grains evolve in disks during
the planet formation process.


  We present an extensive search for a general class of flipped $SU(5)$ models
built within the free fermionic formulation of the heterotic string. We
describe a set of algorithms which constitute the basis for a computer program
capable of generating systematically the massless spectrum and the
superpotential of all possible models within the class we consider. Our search
through the huge parameter space to be explored is simplified considerably by
the constraint of $N=1$ spacetime supersymmetry and the need for extra $Q,\bar
Q$ representations beyond the standard ones in order to possibly achieve string
gauge coupling unification at scales of ${\cal O}(10^{18}\GeV)$. Our results
are remarkably simple and evidence the large degree of redundancy in this kind
of constructions. We find one model with gauge group $SU(5)\times
U(1)_\ty\times SO(10)_h\times SU(4)_h\times U(1)^5$ and fairly acceptable
phenomenological properties. We study the $D$- and $F$-flatness constraints and
the symmetry breaking pattern in this model and conclude that string gauge
coupling unification is quite possible.


  For a graph $H$, the Tur\'{a}n number of $H$, denoted by ex$(n,H)$, is the
maximum number of edges of an $n$-vertex $H$-free graph. Let $g(n,H)$ denote
the maximum number of edges not contained in any monochromatic copy of $H$ in a
$2$-edge-coloring of $K_n$. A wheel $W_m$ is a graph formed by connecting a
single vertex to all vertices of a cycle of length $m-1$. The Tur\'{a}n number
of $W_{2k}$ was determined by Simonovits in the 1960s. In this paper, we
determine ex$(n,W_{2k+1})$ when $n$ is sufficiently large. We also show that,
for sufficiently large $n$, $g(n,W_{2k+1})=\mbox{ex}(n,W_{2k+1})$ which
confirms a conjecture posed by Keevash and Sudakov for odd wheels.


  The best clocks to date control the atomic motion by trapping the sample in
an optical lattice and then interrogate the atomic transition by shining on
these atoms a distinct laser of controlled frequency. In order to perform both
tasks simultaneously and with the same laser field, we propose to use instead
the levitation of a Bose-Einstein condensate through multiple-wave atomic
interferences. The levitating condensate experiences a coherent localization in
momentum and a controlled diffusion in altitude. The sample levitation is bound
to resonance conditions used either for frequency or for acceleration
measurements. The chosen vertical geometry solves the limitations imposed by
the sample free fall in previous optical clocks using also atomic
interferences. This configuration yields multiple-wave interferences enabling
levitation and enhancing the measurement sensitivity. This setup, analogous to
an atomic resonator in momentum space, constitutes an attractive alternative to
existing atomic clocks and gravimeters.


  X-ray based imaging modalities are widely used in research, industry, and in
the medical field. Consequently, there is a strong motivation to improve their
performances with respect to resolution, dose, and contrast. Ghost imaging (GI)
is an imaging technique in which the images are reconstructed from measurements
with a single-pixel detector using correlation between the detected intensities
and the intensity structures of the input beam. The method that has been
recently extended to X-rays provides intriguing possibilities to overcome
several fundamental challenges of X-ray imaging. However, understanding the
potential of the method and designing X-ray GI systems pose challenges since in
addition to geometric optic effects, radiation-matter interactions must be
considered. Such considerations are fundamentally more complex than those at
longer wavelengths as relativistic effects such as Compton scattering become
significant. In this work we present a new method for designing and
implementing GI systems using the particle transport code FLUKA, that rely on
Monte Carlo (MC) sampling. This new approach enables comprehensive
consideration of the radiation-matter interactions, facilitating successful
planning of complex GI systems. As an example of an advanced imaging system, we
simulate a high-resolution scattered photons GI technique.


  The dying ReLU refers to the problem when ReLU neurons become inactive and
only output 0 for any input. There are many empirical and heuristic
explanations of why ReLU neurons die. However, little is known about its
theoretical analysis. In this paper, we rigorously prove that a deep ReLU
network will eventually die in probability as the depth goes to infinite.
Several methods have been proposed to alleviate the dying ReLU. Perhaps, one of
the simplest treatments is to modify the initialization procedure. One common
way of initializing weights and biases uses symmetric probability
distributions, which suffers from the dying ReLU. We thus propose a new
initialization procedure, namely, a randomized asymmetric initialization. We
prove that the new initialization can effectively prevent the dying ReLU. All
parameters required for the new initialization are theoretically designed.
Numerical examples are provided to demonstrate the effectiveness of the new
initialization procedure.


  Uncertainty relations play a crucial role in quantum mechanics. Well-defined
methods exist for the derivation of such uncertainties for pairs of
observables. Other approaches also allow the formulation of time-energy
uncertainty relations, even though time is not an operator in standard quantum
mechanics. However, in these cases, different approaches are associated with
different meanings and interpretations for these relations. The one of interest
here revolves around the idea of whether quantum mechanics inherently imposes a
fundamental minimum duration for energy measurements with a certain precision.
In our study, we investigate within the Page and Wootters timeless framework
how energy measurements modify the relative "flow of time" between internal and
external clocks. This provides a unified framework for discussing the subject,
allowing us to recover previous results and derive new ones. In particular, we
show that the duration of an energy measurement carried out by an external
system cannot be performed arbitrarily fast from the perspective of the
internal clock. Moreover, we show that during any energy measurement the
evolution given by the internal clock is non-unitary.


  In recent work it was clarified that amorphous solids under strain control do
not possess nonlinear elastic theory in the sense that the shear modulus exists
but nonlinear moduli exhibit sample to sample fluctuations that grow without
bound with the system size. More relevant however for experiments are the
conditions of stress control. In the present Communication we show that also
under stress control the shear modulus exists but higher order moduli show
unbounded sample to sample fluctuation. The unavoidable consequence is that the
characterization of stress-strain curves in experiments should be done with a
stress-dependent shear modulus rather than with nonlinear expansions.


  Evolving 5G New Radio (NR) to support non-terrestrial networks (NTNs),
particularly satellite communication networks, is under exploration in 3GPP.
The movement of the spaceborne platforms in NTNs may result in large timing
varying Doppler shift that differs for devices in different locations. Using
orthogonal frequency-division multiple access (OFDMA) in the uplink, each
device will need to apply a different frequency adjustment value to compensate
for the Doppler shift. To this end, the 3GPP Release-17 work on NTNs assumes
that an NTN device is equipped with a global navigation satellite system (GNSS)
chipset and thereby can determine its position and calculate the needed
frequency adjustment value using its position information and satellite
ephemeris data. This makes GNSS support essential for the NTN operation.
However, GNSS signals are weak, not ubiquitous, and susceptible to interference
and spoofing. We show that devices without access to GNSS signals can utilize
reference signals in more than one frequency position in an OFDM carrier to
estimate the Doppler shift and thereby determine the needed frequency
adjustment value for pre-compensating the Doppler shift in the uplink. We
analyze the performance, elaborate on how to utilize the NR reference signals,
and present simulation results. The solution can reduce the dependency of NTN
operation on GNSS with reasonable complexity and performance trade-off.


  In this paper subdivision schemes, which are used for functions approximation
and curves generation, are considered. In classical case, for the functions
defined on the real line, the theory of subdivision schemes is widely known due
to multiple applications in constructive approximation theory, signal
processing as well as for generating fractal curves and surfaces. Subdivision
schemes on a dyadic half-line, which is a positive half-line, equipped with the
standard Lebesgue measure and the digitwise binary addition operation, where
the Walsh functions play the role of exponents, are defined and studied.
Necessary and sufficient convergence conditions of the subdivision schemes in
terms of spectral properties of matrices and in terms of the smoothness of the
solution of the corresponding refinement equation are proved. The problem of
the convergence of subdivision schemes with non-negative coefficients is also
investigated. Explicit convergence criterion of the subdivision schemes with
four coefficients is obtained. As an auxiliary result fractal curves on a
dyadic half-line are defined and the formula of their smoothness is proved. The
paper contains various illustrations and numerical results.


  In this paper, we present our champion solution to the Global Artificial
Intelligence Technology Innovation Competition Track 1: Medical Imaging
Diagnosis Report Generation. We select CPT-BASE as our base model for the text
generation task. During the pre-training stage, we delete the mask language
modeling task of CPT-BASE and instead reconstruct the vocabulary, adopting a
span mask strategy and gradually increasing the number of masking ratios to
perform the denoising auto-encoder pre-training task. In the fine-tuning stage,
we design iterative retrieval augmentation and noise-aware similarity bucket
prompt strategies. The retrieval augmentation constructs a mini-knowledge base,
enriching the input information of the model, while the similarity bucket
further perceives the noise information within the mini-knowledge base, guiding
the model to generate higher-quality diagnostic reports based on the similarity
prompts. Surprisingly, our single model has achieved a score of 2.321 on
leaderboard A, and the multiple model fusion scores are 2.362 and 2.320 on the
A and B leaderboards respectively, securing first place in the rankings.


  The Ashtekar variables have been use to find a number of exact solutions in
quantum gravity and quantum cosmology. We investigate the origin of these
solutions in the context of a number of canonical transformations (both complex
and real) of the basic Hamiltonian variables of general relativity. We are able
to present several new solutions in the minisuperspace (quantum cosmology)
sector. The meaning of these solutions is then discussed.


  We propose a novel method for computing exact pointwise robustness of deep
neural networks for all convex $\ell_p$ norms. Our algorithm, GeoCert, finds
the largest $\ell_p$ ball centered at an input point $x_0$, within which the
output class of a given neural network with ReLU nonlinearities remains
unchanged. We relate the problem of computing pointwise robustness of these
networks to that of computing the maximum norm ball with a fixed center that
can be contained in a non-convex polytope. This is a challenging problem in
general, however we show that there exists an efficient algorithm to compute
this for polyhedral complices. Further we show that piecewise linear neural
networks partition the input space into a polyhedral complex. Our algorithm has
the ability to almost immediately output a nontrivial lower bound to the
pointwise robustness which is iteratively improved until it ultimately becomes
tight. We empirically show that our approach generates distance lower bounds
that are tighter compared to prior work, under moderate time constraints.


  The effect of phonon scattering by surface roughness on the thermal
conductance in mesoscopic systems at low temperatures is calculated using full
elasticity theory. The low frequency behavior of the scattering shows novel
power law dependences arising from the unusual properties of the elastic modes.
This leads to new predictions for the low temperature depression of the thermal
conductance below the ideal universal value. Comparison with the data of Schwab
et al. [Nature 404, 974 (2000)] suggests that surface roughness on a scale of
the width of the thermal pathway is important in the experiment.


  We report a measurement of the exclusive $B^+$ meson decay to the final state
$D_s^- K^+\pi^+$ using $520 \times 10^{6} B\bar{B}$ pairs collected near the
$\Upsilon(4S)$ resonance, with the Belle detector at the KEKB asymmetric-energy
$e^+e^-$ collider. Using the $D_S^- \to \phi \pi^-$ decay mode to reconstruct
$D_s^-$ mesons, we obtain the branching fraction ${\cal B}(B^+\to
D_s^-K^+\pi^+)= (1.77^{+0.12}_{-0.12} {\mathrm (stat)} \pm 0.16 {\mathrm
(syst)} \pm 0.23 {\cal(B)})\times 10^{-4}$. We also present preliminary results
of a study of the two-body $D_sK$, $D_s\pi$ and $K\pi$ subsystems observed in
this final state.


  Fast spinning neutron stars, recycled in low mass binaries, may have accreted
a substantial amount of mass. The available relativistic measurements of
neutron star masses, all clustering around 1.4 M_sun, however refer mostly to
slowly rotating neutron stars which accreted a tiny amount of mass during
evolution in a massive binary system. We develop a semi-analytical model for
studying the evolution of the spin period P of a magnetic neutron star as a
function of the baryonic mass load M_{ac}; evolution is followed down to
submillisecond periods and the magnetic field is allowed to decay significantly
before the end of recycling. We use different equations of state and include
rotational deformation effects, the presence of a strong gravitational field
and of a magnetosphere. For the non-magnetic case, comparison with numerical
relativistic codes shows the accuracy of our description. The minimum accreted
mass requested to spin-up a magnetized 1.35M_sun-neutron star at a few
millisecond is 0.05 M_sun, while this value doubles for an unmagnetized neutron
star. Below 1 millisecond the request is of at least 0.25 M_sun. There may
exist a yet undetected population of massive submillisecond neutron stars. The
discovery of a submillisecond neutron star would imply a lower limit for its
mass of about 1.7M_sun.


  The Ruddlesden-Popper (RP) series of iridates (Srn+1IrnO3n+1) have been the
subject of much recent attention due to the anticipation of emergent physics
arising from the cooperative action of spin-orbit (SO) driven band splitting
and Coulomb interactions[1-3]. However an ongoing debate over the role of
correlations in the formation of the charge gap and a lack of understanding of
the effects of doping on the low energy electronic structure have hindered
experimental progress in realizing many of the predicted states[4-8] including
possible high-Tc superconductivity[7,9]. Using scanning tunneling spectroscopy
we map out the spatially resolved density of states in the n=2 RP member,
Sr3Ir2O7 (Ir327). We show that the Ir327 parent compound, argued to exist only
as a weakly correlated band insulator in fact possesses a substantial ~130meV
charge excitation gap driven by an interplay between structure, SO coupling and
correlations. A critical component in distinguishing the intrinsic electronic
character within the inhomogeneous textured electronic structure is our
identification of the signature of missing apical oxygen defects, which play a
critical role in many of the layered oxides. Our measurements combined with
insights from calculations reveal how apical oxygen vacancies transfer spectral
weight from higher energies to the gap energies thereby revealing a path toward
obtaining metallic electronic states from the parent-insulating states in the
iridates.


  The ionizing fluxes from quasars and other active galactic nuclei (AGN) are
critical for interpreting their emission-line spectra and for photoionizing and
heating the intergalactic medium (IGM). Using far-ultraviolet spectra from the
Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), we
directly measure the rest-frame ionizing continua and emission lines for 159
AGN at redshifts 0.001 < z_AGN < 1.476 and construct a composite spectrum from
475-1875A. We identify the underlying AGN continuum and strong EUV emission
lines from ions of oxygen, neon, and nitrogen after masking out absorption
lines from the HI Lya forest, 7 Lyman-limit systems (N_HI > 10^17.2 cm^-2) and
214 partial Lyman-limit systems (15.0 < log N_HI < 17.2). The 159 AGN exhibit a
wide range of FUV/EUV spectral shapes, F_nu \propto nu^(alpha_nu), typically
with -2 < alpha_nu < 0 and no discernible continuum edges at 912A (H I) or 504A
(He I). The composite rest-frame continuum shows a gradual break at 1000 A,
with mean spectral index alpha_nu = -0.83 +/- 0.09 in the FUV (1200-2000A)
steepening to alpha_nu = -1.41 +/- 0.15 in the EUV (500-1000A). We discuss the
implications of the UV flux turnovers and lack of continuum edges for the
structure of accretion disks, AGN mass inflow rates, and luminosities relative
to Eddington values.


  Logistic models are studied as a tool to convert output from numerical
weather forecasting systems (deterministic and ensemble) into probability
forecasts for binary events. A logistic model obtains by putting the
logarithmic odds ratio equal to a linear combination of the inputs. As any
statistical model, logistic models will suffer from over-fitting if the number
of inputs is comparable to the number of forecast instances. Computational
approaches to avoid over-fitting by regularisation are discussed, and efficient
approaches for model assessment and selection are presented. A logit version of
the so called lasso, which is originally a linear tool, is discussed. In lasso
models, less important inputs are identified and discarded, thereby providing
an efficient and automatic model reduction procedure. For this reason, lasso
models are particularly appealing for diagnostic purposes.


  Recent work has advocated for training AI models on ever-larger datasets,
arguing that as the size of a dataset increases, the performance of a model
trained on that dataset will correspondingly increase (referred to as "scaling
laws"). In this paper, we draw on literature from the social sciences and
machine learning to critically interrogate these claims. We argue that this
scaling law relationship depends on metrics used to measure performance that
may not correspond with how different groups of people perceive the quality of
models' output. As the size of datasets used to train large AI models grows and
AI systems impact ever larger groups of people, the number of distinct
communities represented in training or evaluation datasets grows. It is thus
even more likely that communities represented in datasets may have values or
preferences not reflected in (or at odds with) the metrics used to evaluate
model performance in scaling laws. Different communities may also have values
in tension with each other, leading to difficult, potentially irreconcilable
choices about metrics used for model evaluations -- threatening the validity of
claims that model performance is improving at scale. We end the paper with
implications for AI development: that the motivation for scraping ever-larger
datasets may be based on fundamentally flawed assumptions about model
performance. That is, models may not, in fact, continue to improve as the
datasets get larger -- at least not for all people or communities impacted by
those models. We suggest opportunities for the field to rethink norms and
values in AI development, resisting claims for universality of large models,
fostering more local, small-scale designs, and other ways to resist the impetus
towards scale in AI.


  Julius Whiston and Jan Saxl showed that the size of an irredundant generating
set of the group G=PSL(2,p) is at most four and computed the size m(G) of a
maximal set for many primes. We will extend this result to a larger class of
primes, with a surprising result that when p\not\equiv\pm 1\mod 10, m(G)=3
except for the special case p=7. In addition, we will determine which orders of
elements in irredundant generating sets of PSL(2,p) with lengths less than or
equal to four are possible in most cases. We also give some remarks about the
behavior of PSL(2,p) with respect to the replacement property for groups.


  In this Colloquium, the wavefunction-based Multiconfigurational
Time-Dependent Hartree approaches to the dynamics of indistinguishable
particles (MCTDH-F for Fermions and MCTDH-B for Bosons) are reviewed. MCTDH-B
and MCTDH-F or, together, MCTDH-X are methods for describing correlated quantum
systems of identical particles by solving the time-dependent Schr\"odinger
equation from first principles. MCTDH-X is used to accurately model the
dynamics of real-world quantum many-body systems in atomic, molecular, and
optical physics. The key feature of these approaches is the time-dependence and
optimization of the single-particle states employed for the construction of a
many-body basis set, which yields nonlinear working equations. We briefly
describe the historical developments that have lead to the formulation of the
MCTDH-X methods and motivate the necessity for wavefunction-based approaches.
We sketch the derivation of the unified MCTDH-F and MCTDH-B equations of motion
for complete and also specific restricted configuration spaces. The strengths
and limitations of the MCTDH-X approach are assessed via benchmarks against an
exactly solvable model and via convergence checks. We highlight some
applications to instructive and experimentally-realized quantum many-body
systems: the dynamics of atoms in Bose-Einstein condensates in magneto-optical
and optical traps and of electrons in atoms and molecules. We discuss the
current development and frontiers in the field of MCTDH-X: theories and
numerical methods for indistinguishable particles, for mixtures of multiple
species of indistinguishable particles, the inclusion of nuclear motion for the
nonadiabatic dynamics of atomic and molecular systems, as well as the
multilayer and second-quantized-representation approaches, and the
orbital-adaptive time-dependent coupled-cluster theory are discussed.


  According to DiPerna-Lions theory, velocity fields with weak derivatives in
$L^p$ spaces possess weakly regular flows. When a velocity field is perturbed
by a white noise, the corresponding (stochastic) flow is far more regular in
spatial variables; a $d$-dimensional diffusion with a drift in $L^{r,q}$ space
($r$ for the spatial variable and $q$ for the temporal variable) possesses weak
derivatives with stretched exponential bounds, provided that $r/d+2/q<1$. As an
application we show that a Hamiltonian system that is perturbed by a white
noise produces a symplectic flow provided that the corresponding Hamiltonian
function $H$ satisfies
  $\nabla H\in L^{r,q}$ with $r/d+2/q<1$. As our second application we derive a
Constantin-Iyer type circulation formula for certain weak solutions of
Navier-Stokes equation.


  The aim of this paper is to study the pro-algebraic fundamental group of a
compact Kaehler manifold. Following work by Simpson, the structure of this
group's pro-reductive quotient is already well understood. We show that
Hodge-theoretic methods can also be used to establish that the pro-unipotent
radical is quadratically presented. This generalises both Deligne et al.'s
result on the de Rham fundamental group, and Goldman and Millson's result on
deforming representations of Kaehler groups, and can be regarded as a
consequence of formality of the schematic homotopy type. New examples are given
of groups which cannot arise as Kaehler groups.


  In this paper, by the use of the topological current theory, the topological
structures and the dynamic processes in thin-film ferromagnetic systems are
investigated directly from viewpoint of topology. It is found that the
topological charge of a thin-film ferromagnetic system can be changed by
annihilation or creation processes of opposite polarized vortex-antivortex
pairs taking place at space-time singularities of the normalized magnetization
vector field of the system, the variation of the topological charge is integer
and can further be expressed in terms of the Hopf indices and Brouwer degrees
of the magnetization vector field around the singularities. Moreover, the
change of the topological charge of the system is crucial to vortex core
reversal processes in ferromagnetic thin films. With the help of the
topological current theory and implicit function theorem, the processes of
vortex merging, splitting as well as vortex core


  It is shown that the generator of the nonstandard fermion-monopole
supersymmetry uncovered by De Jonghe, Macfarlane, Peeters and van Holten, and
the generator of its standard N=1/2 supersymmetry have to be supplemented by
their product operator to be treated as independent supercharge. As a result,
the fermion-monopole system possesses the nonlinear N=3/2 supersymmetry having
the nature of the 3D spin-1/2 free particle's supersymmetry generated by the
supercharges represented in a scalar form. Analyzing the supercharges'
structure, we trace how under reduction of the fermion-monopole system to the
spherical geometry the nonlinear N=3/2 superalgebra comprising the Hamiltonian
and the total angular momentum as even generators is transformed into the
standard linear N=1 superalgebra with the Hamiltonian to be the unique even
generator.


  We not only reproduce burst of short-wavelength spin waves (SWs) observed in
recent experiment [S. Woo et al., Nat. Phys. 13, 448 (2017)] on
magnetic-field-driven annihilation of two magnetic domain walls (DWs) but,
furthermore, we predict that this setup additionally generates highly unusual}
pumping of electronic spin currents in the absence of any bias voltage. Prior
to the instant of annihilation, their power spectrum is ultrabroadband, so they
can be converted into rapidly changing in time charge currents, via the inverse
spin Hall effect, as a source of THz radiation of bandwidth $\simeq 27$ THz
where the lowest frequency is controlled by the applied magnetic field. The
spin pumping stems from time-dependent fields introduced into the quantum
Hamiltonian of electrons by the classical dynamics of localized magnetic
moments (LMMs) comprising the domains. The pumped currents carry spin-polarized
electrons which, in turn, exert backaction on LMMs in the form of nonlocal
damping which is more than twice as large as conventional local Gilbert
damping. The nonlocal damping can substantially modify the spectrum of emitted
SWs when compared to widely-used micromagnetic simulations where conduction
electrons are completely absent. Since we use fully microscopic (i.e.,
Hamiltonian-based) framework, self-consistently combining time-dependent
electronic nonequilibrium Green functions with the Landau-Lifshitz-Gilbert
equation, we also demonstrate that previously derived phenomenological formulas
miss ultrabroadband spin pumping while underestimating the magnitude of
nonlocal damping due to nonequilibrium electrons.


  This paper describes in detail the construction of a local right-handed,
orthogonal curvilinear coordinate system whose axes are along the local
tangent, the local azimuth and the local normal of an analytically defined 3D
surface of rotation, whose shape mimics the shape of a plasma focus current
sheath. Expressions for various differential operators are derived in a
tutorial format for the benefit of young researchers and non-specialists.
Physical problems expressed in this coordinate system would benefit from the
natural symmetry properties of the plasma focus sheath. For example, the normal
component of current density is zero and the velocity has mainly the normal
component. This paper is meant to serve as a readily available reference in the
hope that it would be found useful.


  We reconsider the minimal supersymmetric SO(10) model, where only one {\bf
10} and one $\bar{\bf 126}$ Higgs multiplets have Yukawa couplings with matter
multiplets. The model is generalized to include CP-violating phases, and
examined how well its predictions can meet the current neutrino oscillation
data. Using the electroweak scale data about six quark masses, three angles and
one CP-phase in the Cabibbo-Kobayashi-Maskawa matrix and three charged-lepton
masses and given $\tan \beta$ (the ratio of vacuum expectation values of a pair
of Higgs doublets), we obtain the Pontecorvo-Maki-Nakagawa-Sakata matrix and
the ratio, $\Delta m_\odot^2/\Delta m_\oplus^2 $, as functions of only one free
parameter in the model. In our analysis, one-loop renormalization group
equations for the gauge couplings, the Yukawa couplings and the effective
dimension-five operator are used to connect the data between the electroweak
scale and the grand unification scale. Fixing the free parameter appropriately,
we find, for example, $\sin^2 2 \theta_{12} \sim 0.72$, $\sin^2 2 \theta_{23}
\sim 0.90$, $\sin^2 2 \theta_{13} \sim 0.16$ and $\Delta m_\odot^2/\Delta
m_\oplus^2 \sim 0.19$ with $\tan \beta = 45$, which are in agreement with the
current neutrino oscillation data.


  The phase diagram of a model describing doped CuGeO$_3$ is derived. The model
emphasizes the role of local moments released by the impurities and randomly
distributed inside the gaped singlet background. The phase diagram is
investigated by two methods: (i) in a mean field treatment of the interchain
coupling and (ii) in a real space decimation procedure in a two dimensional
model of randomly distributed moments. Both methods lead to similar results, in
a qualitative agreement with experiments. In particular, a transition to an
inhomogeneous N\'eel phase is obtained for arbitrary small doping. From the
decimation procedure, we interpret this phase at very low doping as a {\sl
Griffith antiferromagnet}. Namely, it does not have a true long range order
down to zero temperature. Nonetheless, large magnetically ordered clusters
appear already at relatively high temperatures. This demonstrates the role of
disorder in the theoretical description of doping in CuGeO$_3$. A detailed
comparison with other approaches is also given.


  We study a fundamental problem in Computational Geometry, the planar
two-center problem. In this problem, the input is a set $S$ of $n$ points in
the plane and the goal is to find two smallest congruent disks whose union
contains all points of $S$. A longstanding open problem has been to obtain an
$O(n\log n)$-time algorithm for planar two-center, matching the $\Omega(n\log
n)$ lower bound given by Eppstein [SODA'97]. Towards this, researchers have
made a lot of efforts over decades. The previous best algorithm, given by Wang
[SoCG'20], solves the problem in $O(n\log^2 n)$ time. In this paper, we present
an $O(n\log n)$-time (deterministic) algorithm for planar two-center, which
completely resolves this open problem.


  We extend the systematic calculation of an approximately relativistic
Hamiltonian for centre of mass and internal dynamics of an electromagnetically
bound two-particle system by Sonnleitner and Barnett [1] to the case including
a weak post-Newtonian gravitational background field, described by the
Eddington--Robertson parametrised post-Newtonian metric. Starting from a proper
relativistic description of the situation, this approach allows to
systematically derive the coupling of the model system to gravity, instead of
`guessing' it by means of classical notions of relativistic effects.
  We embed this technical result into a critical discussion concerning the
problem of implementing and interpreting general couplings to the gravitational
field and the connected problem of how to properly address the question
concerning the validity of the Equivalence Principle in Quantum Mechanics.


  We consider an algebraic formulation of Quantum Theory and develop a
combinatorial model of the Heisenberg-Weyl algebra structure. It is shown that
by lifting this structure to the richer algebra of graph operator calculus, we
gain a simple interpretation involving, for example, the natural composition of
graphs. This provides a deeper insight into the algebraic structure of Quantum
Theory and sheds light on the intrinsic combinatorial underpinning of its
abstract formalism.


  We propose a digital-analog quantum algorithm for simulating the
Hubbard-Holstein model, describing strongly-correlated fermion-boson
interactions, in a suitable architecture with superconducting circuits. It
comprises a linear chain of qubits connected by resonators, emulating
electron-electron (e-e) and electron-phonon (e-p) interactions, as well as
fermion tunneling. Our approach is adequate for a digital-analog quantum
computing (DAQC) of fermion-boson models including those described by the
Hubbard-Holstein model. We show the reduction in the circuit depth of the DAQC
algorithm, a sequence of digital steps and analog blocks, outperforming the
purely digital approach. We exemplify the quantum simulation of a half-filling
two-site Hubbard-Holstein model. In such example we obtain fidelities larger
than 0.98, showing that our proposal is suitable to study the dynamical
behavior of solid-state systems. Our proposal opens the door to computing
complex systems for chemistry, materials, and high-energy physics.


  The consistency of doubly robust estimators relies on consistent estimation
of at least one of two nuisance regression parameters. In moderate to large
dimensions, the use of flexible data-adaptive regression estimators may aid in
achieving this consistency. However, $n^{1/2}$-consistency of doubly robust
estimators is not guaranteed if one of the nuisance estimators is inconsistent.
In this paper we present a doubly robust estimator for survival analysis with
the novel property that it converges to a Gaussian variable at $n^{1/2}$-rate
for a large class of data-adaptive estimators of the nuisance parameters, under
the only assumption that at least one of them is consistently estimated at a
$n^{1/4}$-rate. This result is achieved through adaptation of recent ideas in
semiparametric inference, which amount to: (i) Gaussianizing (i.e., making
asymptotically linear) a drift term that arises in the asymptotic analysis of
the doubly robust estimator, and (ii) using cross-fitting to avoid entropy
conditions on the nuisance estimators. We present the formula of the asymptotic
variance of the estimator, which allows computation of doubly robust confidence
intervals and p-values. We illustrate the finite-sample properties of the
estimator in simulation studies, and demonstrate its use in a phase III
clinical trial for estimating the effect of a novel therapy for the treatment
of HER2 positive breast cancer.


  We prove analogues for hypergraphs of Szemer\'edi's regularity lemma and the
associated counting lemma for graphs. As an application, we give the first
combinatorial proof of the multidimensional Szemer\'edi theorem of Furstenberg
and Katznelson, and the first proof that provides an explicit bound. Similar
results with the same consequences have been obtained independently by Nagle,
R\"odl, Schacht and Skokan.


  Transferring knowledge across a sequence of reinforcement-learning tasks is
challenging, and has a number of important applications. Though there is
encouraging empirical evidence that transfer can improve performance in
subsequent reinforcement-learning tasks, there has been very little theoretical
analysis. In this paper, we introduce a new multi-task algorithm for a sequence
of reinforcement-learning tasks when each task is sampled independently from
(an unknown) distribution over a finite set of Markov decision processes whose
parameters are initially unknown. For this setting, we prove under certain
assumptions that the per-task sample complexity of exploration is reduced
significantly due to transfer compared to standard single-task algorithms. Our
multi-task algorithm also has the desired characteristic that it is guaranteed
not to exhibit negative transfer: in the worst case its per-task sample
complexity is comparable to the corresponding single-task algorithm.


  From the perfect radial symmetries of radiolarian mineral skeletons to the
broken symmetry of homochirality, the logic of Nature's regularities has
fascinated scientists for centuries. Some of Nature's symmetries are clearly
visible in morphology and physical structure, whereas others are hidden in the
network of interactions among system components. Just as visible symmetries and
asymmetries contribute to the system's beauty, might hidden symmetries
contribute to the system's functional harmony? And if so, how? Here we
demonstrate that the interaction networks of biological systems from cell
signaling to cancer display a form of dynamical reflection symmetry that serves
to expand their dynamical complexity. The expansion proceeds according to
precise rules regarding the lengths of dynamical cycles, made possible by a
peculiar imbalance between excitation and inhibition. To probe the conditions
under which this reflection symmetry evolves, we use a multi-objective genetic
algorithm to produce networks with long dynamical cycles. We find that local
structural motifs that break the reflection symmetry are deleted in the
evolutionary process, providing evidence for symmetry's causal role in
dynamical complexity. Finally, we identify symmetries in real continuous-valued
scRNA-seq data of gene expression in drug-resistant cancer cells. Broadly, our
work reveals a class of hidden symmetries in biology, present in the network of
interactions among system components, and it underscores their functional
importance. Mathematically simple and computational inexpensive, our approach
is applicable to the types of biological data commonly acquired in modern
experiments.


  In this work we present an experimental study of structure and phase
stability in ternary Cu-Sn-In alloys around 55 at.% Cu in the temperature range
100^{\circ}C < T < 550^{\circ}C. We have followed in real-time the sequence of
phase transformations in succesive heating and cooling ramps, using
state-of-the-art neutron powder thermodiffractometry. These experiments were
complemented with calorimetric studies of the same alloys. Our results give
experimental support to the current assessment of the ternary phase diagram in
this composition and temperature range, yielding the sequence of transitions
\eta -> \eta + L -> \epsilon + L with transformation temperatures of
210^{\circ}C and 445^{\circ}C, respectively. The use of neutrons allowed to
overcome common difficulties in phase identification with powder XRD due to
absorption and preferred orientation issues. Even the transitions to liquid
phases could be successfully identified and monitored in situ, turning this
technique into a valuable tool for phase diagram studies of emerging lead-free
solder candidates.


  We calculate the tidal corrections to the loss of angular momentum in a
two-body collision at leading Post-Minkowskian order from an amplitude-based
approach. The eikonal operator allows us to efficiently combine elastic and
inelastic amplitudes, and captures both the contributions due to genuine
gravitational-wave emissions and those due to the static gravitational field.
We calculate the former by harnessing powerful collider-physics techniques such
as reverse-unitarity, thereby reducing them to cut two-loop integrals, and
validate the result with an independent calculation in the Post-Newtonian
limit. For the latter, we can employ the results of arXiv:2203.11915 where
static-field effects were calculated for generic gravitational scattering
events using the leading soft graviton theorem.


  Assessing the impact of an intervention using time-series observational data
on multiple units and outcomes is a frequent problem in many fields of
scientific research. In this paper, we present a novel method to estimate
intervention effects in such a setting by generalising existing approaches
based on the factor analysis model and developing a Bayesian algorithm for
inference. Our method is one of the few that can simultaneously: deal with
outcomes of mixed type (continuous, binomial, count); increase efficiency in
the estimates of the causal effects by jointly modelling multiple outcomes
affected by the intervention; easily provide uncertainty quantification for all
causal estimands of interest. We use the proposed approach to evaluate the
impact that local tracing partnerships (LTP) had on the effectiveness of
England's Test and Trace (TT) programme for COVID-19. Our analyses suggest
that, overall, LTPs had a small positive impact on TT. However, there is
considerable heterogeneity in the estimates of the causal effects over units
and time.


  Let $\mathcal{A}$ be a connected cochain DG algebra such that its underlying
graded algebra $\mathcal{A}^{\#}$ is the graded skew polynomial algebra
$$k\langle x_1,x_2, x_3\rangle/\left(\begin{array}{ccc} x_1x_2+x_2x_1\\
x_2x_3+x_3x_2\\ x_3x_1+x_1x_3 \end {array}\right), |x_1|=|x_2|=|x_3|=1.$$ From
\cite{MWZ} or \cite{MWYZ}, one sees that the differential
$\partial_{\mathcal{A}}$ is determined by \begin{align*} \left(
\begin{array}{c} \partial_{\mathcal{A}}(x_1) \partial_{\mathcal{A}}(x_2)
\partial_{\mathcal{A}}(x_3) \end{array} \right)=M\left( \begin{array}{c} x_1^2
x_2^2 x_3^2 \end{array} \right), \end{align*} for some $M\in M_3(k)$. For the
case $1\le r(M)\le 3$, we compute $H(\mathcal{A})$ case by case. The
computational results in this paper give substantial support for \cite{MWZ},
where the various homological properties of such DG algebras are systematically
studied. We find some examples, which indicate that the cohomology graded
algebra of a Koszul Calabi-Yau DG algebra may be not left (right) Gorenstein.


  In this paper, we describe a Graphical User Interface (GUI) designed to
manage large quantities of image data of a biological system. After setting the
design requirements for the system, we developed an ecology quantification GUI
that assists biologists in analysing data. We focus on the main features of the
interface and we present the results and an evaluation of the system. Finally,
we provide some directions for some future work.


  A heavy path in a weighted graph represents a notion of connectivity and
ordering that goes beyond two nodes. The heaviest path of length l in the
graph, simply means a sequence of nodes with edges between them, such that the
sum of edge weights is maximum among all paths of length l. It is trivial to
state the heaviest edge in the graph is the heaviest path of length 1, that
represents a heavy connection between (any) two existing nodes. This can be
generalized in many different ways for more than two nodes, one of which is
finding the heavy weight paths in the graph. In an influence network, this
represents a highway for spreading information from a node to one of its
indirect neighbors at distance l. Moreover, a heavy path implies an ordering of
nodes. For instance, we can discover which ordering of songs (tourist spots) on
a playlist (travel itinerary) is more pleasant to a user or a group of users
who enjoy all songs (tourist spots) on the playlist (itinerary). This can also
serve as a hard optimization problem, maximizing different types of quantities
of a path such as score, flow, probability or surprise, defined as edge weight.
Therefore, if one can solve the Heavy Path Problem (HPP) efficiently, they can
as well use HPP for modeling and reduce other complex problems to it.


  Encouraged by recent developments in AdS/QCD models for light quark system,
we study heavy quarkonium in the framework of the AdS/QCD models. We calculate
the masses of $c\bar c$ vector meson states using the AdS/QCD models at zero
and at finite temperature. Among the models adopted in this work, we find that
the soft wall model describes the low-lying heavy quark meson states at zero
temperature relatively well. At finite temperature, we observe that once the
bound state is above $T_c$, its mass will increase with temperature until it
dissociates at a temperature of around $494 {\rm MeV}$. It is shown that the
dissociation temperature is fixed by the infrared cutoff of the models. The
present model serves as a unified non perturbative model to investigate the
properties of bound quarkonium states above $T_c$.


  Extensive air showers are generated through interactions of high-energy
cosmic rays impinging the Earth's atmosphere. A new method is described to
infer the attenuation of hadrons in air showers. The numbers of electrons and
muons, registered with the scintillator array of the KASCADE experiment are
used to estimate the energy of the shower inducing primary particle. A large
hadron calorimeter is used to measure the hadronic energy reaching observation
level. The ratio of energy reaching ground level to the energy of the primary
particle is used to derive an attenuation length of hadrons in air showers. In
the energy range from $10^6$ GeV to $3\cdot10^7$ GeV the attenuation length
obtained increases from 170 \gcm2 to 210 \gcm2. The experimental results are
compared to predictions of simulations based on contemporary high energy
interaction models.


  By Descartes' rule of signs, a real degree $d$ polynomial $P$ with all
nonvanishing coefficients, with $c$ sign changes and $p$ sign preservations in
the sequence of its coefficients ($c+p=d$) has $pos\leq c$ positive and
$neg\leq p$ negative roots, where $pos\equiv c($\, mod $2)$ and $neg\equiv
p($\, mod $2)$. For $1\leq d\leq 3$, for every possible choice of the sequence
of signs of coefficients of $P$ (called sign pattern) and for every pair $(pos,
neg)$ satisfying these conditions there exists a polynomial $P$ with exactly
$pos$ positive and exactly $neg$ negative roots (all of them simple). For
$d\geq 4$ this is not so. It was observed that for $4\leq d\leq 10$, in all
nonrealizable cases either $pos=0$ or $neg=0$. It was conjectured that this is
the case for any $d\geq 4$. We show a counterexample to this conjecture for
$d=11$. Namely, we prove that for the sign pattern $(+,-,-,-,-,-,+,+,+,+,+,-)$
and the pair $(1,8)$ there exists no polynomial with $1$ positive, $8$ negative
simple roots and a complex conjugate pair.


  Based on electronic structure calculations, we have found that noble metal
diborides, AgB2 and AuB2, are potential candidates for conventional BCS-type
high temperature superconductors. B 2p density of states dominates at the Fermi
level in comparison with Ag 4d and Au 5d states. Furthermore, the
electron-phonon coupling constant \lambda is much larger in AgB2 and AuB2 than
in MgB2. Estimated transition temperatures for AgB2 and AuB2 are T_c = 59 K and
72 K, respectively. These are about 2 ~ 3 times higher than the estimated T_c =
27 K in MgB2 and almost comparable to those in cuprate superconductors.


  The great scientific and technological advances that are being carried out in
the field of quantum communications, accompanied by large investment programs
such as EuroQCI, are driving the deployment of quantum network throughout the
world. One of the final long-term objectives is to achieve the development of a
quantum internet that provides greater security in its services and new
functionalities that the current internet does not have. This article analyzes
the possible integration strategies of already deployed networks or in the
process of being deployed in order to reach a future global quantum network.
Two strategies based on the SDN paradigm are proposed, based on a hierarchical
controller scheme and on a distributed model. Each of these approaches shows
pros and cons and could be applicable in different use cases. To define these
strategies, the most relevant deployments of quantum communications networks
carried out to date has been analyzed, as well as the different approaches for
a quantum network architecture and topology, and the various proposed
definitions of what quantum internet is and what are the components that would
make it up in an ideal scenario. Finally, several detected opportunities and
challenges regarding security and technological aspects are presented.


  We used the VLA to search for 3He+ emission from two Galactic planetary
nebulae (PNe): NGC6572 and J320}. Standard stellar models predict that the
3He/H abundance ratios for PNe should be 1-2 orders of magnitude higher than
the primordial value (3He/H ~ 1e-5 by number) determined from Galactic HII
region abundances and confirmed by WMAP cosmic microwave background results.
Chemical evolution models suggest that fewer than 5% of all PNe enrich the
interstellar medium (ISM) with 3He at the level of standard stellar models. Our
target PNe are therefore anomalous in that they were selected from a sample
deliberately biased to contain objects with properties that maximized the
likelihood of a 3He detection by the VLA. We have detected the 8.665 GHz
hyperfine 3He+ transition in J320 at the 4 sigma level. The 3He/H abundance
ratio is 1.9e-3 with roughly a factor of two uncertainty. For NGC 6572 we find
an upper limit of 3He/H <= 1e-3. This detection of 3He in J320 makes it the
second PN known to have an anomalously high 3He abundance confirming that at
least some low-mass stars produce significant amounts of 3He that survives to
the PN stage and enriches the ISM.


  We focus on three different convexity principles for local and nonlocal
variational integrals. We prove various generalizations of them, as well as
their equivalences. Some applications to nonlinear eigenvalue problems and
Hardy-type inequalities are given. We also prove a measure-theoretic minimum
principle for nonlocal and nonlinear positive eigenfunctions.


  Despite the overwhelming success of deep learning in various speech
processing tasks, the problem of separating simultaneous speakers in a mixture
remains challenging. Two major difficulties in such systems are the arbitrary
source permutation and unknown number of sources in the mixture. We propose a
novel deep learning framework for single channel speech separation by creating
attractor points in high dimensional embedding space of the acoustic signals
which pull together the time-frequency bins corresponding to each source.
Attractor points in this study are created by finding the centroids of the
sources in the embedding space, which are subsequently used to determine the
similarity of each bin in the mixture to each source. The network is then
trained to minimize the reconstruction error of each source by optimizing the
embeddings. The proposed model is different from prior works in that it
implements an end-to-end training, and it does not depend on the number of
sources in the mixture. Two strategies are explored in the test time, K-means
and fixed attractor points, where the latter requires no post-processing and
can be implemented in real-time. We evaluated our system on Wall Street Journal
dataset and show 5.49\% improvement over the previous state-of-the-art methods.


  Someone knowledgeable in nonstandard analysis may get the feeling that in the
nonlinear theory of generalized functions, too often one works directly on the
nets and spends effort to obtain results that should be clear from general
principles. We want to show that such principles can indeed be introduced and
to illustrate their role to solve problems.
  This text is intended as a tutorial on the use of nonstandard principles in
generalized function theory intended for researchers in the nonlinear theory of
generalized functions.


  Results of an analysis of the BRITE-Constellation and SMEI photometry and
radial-velocity observations, archival and new, of two single-lined
spectroscopic binary systems $\nu$ Centauri and $\gamma$ Lupi are reported. In
the case of $\gamma$ Lup AB, a visual binary, an examination of the light-time
effect shows that component A is the spectroscopic binary. Both $\nu$ Cen and
$\gamma$ Lup exhibit light variations with the orbital period. The variations
are caused by the reflection effect, i.e. heating of the secondary's hemisphere
by the early-B main sequence (MS) primary component's light. The modelling of
the light curves augmented with the fundamental parameters of the primary
components obtained from the literature photometric data and Hipparcos
parallaxes, shows that the secondary components are pre-MS stars, in the
process of contracting onto the MS. $\nu$ Cen and $\gamma$ Lup A are thus found
to be non-eclipsing counterparts of the B2 IV eclipsing binary (and a $\beta$
Cephei variable) 16 (EN) Lac, the B5 IV eclipsing binary (and an SPB variable)
$\mu$ Eri, and the recently discovered LMC nascent eclipsing binaries.


  The total electronic Raman scattering spectrum, including the nonresonant,
mixed and resonant components, is determined for the charge-density-wave (CDW)
phase of the spinless Falicov-Kimball model at half filling within dynamical
mean-field theory. Its frequency dependence is investigated for different
values of the energy of the incident photons. The spectra reflect the different
structures in the density of states and how they are modified by screening and
resonance effects. The calculations are performed for the $B_{\rm 1g}$, $B_{\rm
2g}$ and $A_{\rm 1g}$ symmetries (which are typically examined in experiment).
Our results for the resonance effects of the Raman spectra, found by tuning the
energy of the incident photons, give information about the many-body charge
dynamics of the CDW-ordered phase.


  It has been shown that many networks associated with complex systems are
small-world (they have both a large local clustering coefficient and a small
diameter) and they are also scale-free (the degrees are distributed according
to a power law). Moreover, these networks are very often hierarchical, as they
describe the modularity of the systems that are modeled. Most of the studies
for complex networks are based on stochastic methods. However, a deterministic
method, with an exact determination of the main relevant parameters of the
networks, has proven useful. Indeed, this approach complements and enhances the
probabilistic and simulation techniques and, therefore, it provides a better
understanding of the systems modeled. In this paper we find the radius,
diameter, clustering coefficient and degree distribution of a generic family of
deterministic hierarchical small-world scale-free networks that has been
considered for modeling real-life complex systems.


  In this paper, the Darboux transformation (DT) of the reverse space-time
(RST) nonlocal short pulse equation is constructed by a hodograph
transformation and the eigenfunctions of its Lax pair. The multi-soliton
solutions of the RST nonlocal short pulse equation are produced through the DT,
which can be expressed in terms of determinant representation. By taking
different values of eigenvalues, bounded soliton solutions and unbounded
soliton solutions can be obtained. In addition, based on the degenerate Darboux
transformation, the $N$-positon solutions of the RST nonlocal short pulse
equation are computed from the determinant expression of the multi-soliton
solution. Furthermore, different kinds of mixed solutions are also presented,
and the interaction properties between positons and solitons are investigated.


  We introduce a new algorithm to construct travel time distances between a
point in the interior of a Riemannian manifold and points on the boundary of
the manifold, and describe a numerical implementation of the algorithm. It is
known that the travel time distances for all interior points determine the
Riemannian manifold in a stable manner. We do not assume that there are sources
or receivers in the interior, and use the hyperbolic Neumann-to-Dirichlet map,
or its restriction, as our data. Our algorithm is a variant of the Boundary
Control method, and to our knowledge, this is the first numerical
implementation of the method in a geometric setting.


  De Sitter solutions have been recently conjectured to be incompatible with
quantum gravity. In this paper we critically assess the progress and challenges
of different mechanisms to obtain de Sitter vacua in string compactifications
and compare them to quintessence models. We argue that, despite recent
criticisms, de Sitter models reached a level of concreteness and calculational
control which has been improving over time. On the other hand, building string
models of quintessence appears to be more challenging and requires additional
fine-tuning. We discuss the tension between the swampland conjecture and the
Higgs potential and find examples which can evade fifth-force bounds even if
they seem very hard to realise in string theory. We also comment on the tension
with low-redshift data and explore ultra-light axions from string theory as
dark energy candidates.


  Racetrack memory is a non-volatile memory engineered to provide both high
density and low latency, that is subject to synchronization or shift errors.
This paper describes a fast coding solution, in which delimiter bits assist in
identifying the type of shift error, and easily implementable graph-based codes
are used to correct the error, once identified. A code that is able to detect
and correct double shift errors is described in detail.


  We prove a short time existence result for a system consisting of a geometric
evolution equation for a hypersurface and a parabolic equation on this evolving
hypersurface. More precisely, we discuss a mean curvature flow scaled with a
term that depends on a quantity defined on the surface coupled to a diffusion
equation for that quantity. The proof is based on a splitting ansatz, solving
both equations separately using linearization and a contraction argument. Our
result is formulated for the case of immersed hypersurfaces and yields a
uniform lower bound on the existence time that allows for small changes in the
initial value of the height function.


  The galaxy Malin 1 contains the largest stellar disk known but the formation
mechanism of this structure has been elusive. In this paper, we report a Malin
1 analogue in the 100 Mpc IllustrisTNG simulation and describe its formation
history. At redshift zero, this massive galaxy, having a maximum circular
velocity $V_{\rm max}$ of 430 ${\rm km\ s^{-1}}$, contains a 100 kpc
gas/stellar disk with morphology similar to Malin 1. The simulated galaxy
reproduces well many observed features of Malin 1's vast disk, including its
stellar ages, metallicities, and gas rotation curve. We trace the extended disk
back in time and find that a large fraction of the cold gas at redshift zero
originated from the cooling of hot halo gas, triggered by the merger of a pair
of intruding galaxies. Our finding provides a novel way to form large galaxy
disks as extreme as Malin 1 within the current galaxy formation framework.


  If the Zeeman energy is small, the lowest energy excitations of a two
dimensional electron gas at filling factor nu=1 are spin waves (spin flip
excitations). At nu slightly larger (smaller) than unity, reversed spin
electrons (spin holes) can form bound states with K spin waves that are known
as skyrmions, S_K^- (antiskyrmions, S_K^+). It is suggested in this work that a
valence hole can also bind K spin waves to form an excitonic complex X_K^+,
analogous to the S_K^+. One spin hole of the S_K^+ is simply replaced by the
valence hole. At nu<=1, a small number of S_K^+'s are present before
introduction of the valence hole. The (S_K^+)-(X_K^+) repulsion leads to
correlations and photoluminescence similar to those of a dilute
electron-(charged-exciton) (e-X^-) system at nu<=1/3. At nu>=1, the
(S_K^-)-(X_K^+) attraction can potentially lead to different behavior.


  Strategies and concepts for the design of THz emitters based on the quantum
cascade scheme are analyzed and modeled in terms of a fully three-dimensional
Monte Carlo approach; this allows for a proper inclusion of both
carrier-carrier and carrier-phonon scattering mechanisms. Starting from the
simulation of previously published far-infrared emitters, where no population
inversion is achieved, two innovative designs are proposed. The first one
follows the well-established chirped-superlattice scheme whereas the second one
employs a double-quantum well superlattice to allow energy relaxation through
optical phonon emission. For both cases a significant population inversion is
predicted at temperatures up to 80 K.


  Recently, Yuan et al. (2016) have shown the effectiveness of using Long
Short-Term Memory (LSTM) for performing Word Sense Disambiguation (WSD). Their
proposed technique outperformed the previous state-of-the-art with several
benchmarks, but neither the training data nor the source code was released.
This paper presents the results of a reproduction study of this technique using
only openly available datasets (GigaWord, SemCore, OMSTI) and software
(TensorFlow). From them, it emerged that state-of-the-art results can be
obtained with much less data than hinted by Yuan et al. All code and trained
models are made freely available.


  We discuss spectropolarimetric measurements of photospheric (Fe I 630.25 nm)
and chromospheric (Ca II 854.21 nm) spectral lines. Our long-term goal is to
diagnose properties of the magnetic field near the base of the corona. We
compare ground-based two-dimensional spectropolarimetric measurements with
(almost) simultaneous space-based slit spectropolarimetry. The ground-based
observations were obtained May 20, 2008, with IBIS in spectropolarimetric mode,
The space observations were obtained with the Spectro-Polarimeter aboard the
HINODE satellite. The agreement between the near-simultaneous co-spatial IBIS
and HINODE Stokes-V profiles at 630.25 nm is excellent, with V/I amplitudes
compatible with to within 1 %. IBIS QU measurements are affected by residual
crosstalk from V, arising from calibration inaccuracies, not from any inherent
limitation of imaging spectroscopy. We use a PCA analysis to quantify the
detected cross talk. Chromospheric magnetic fields are difficult to constrain
by polarization of Ca II lines alone. However, we demonstrate that high
cadence, high angular resolution monochromatic images of fibrils in Ca II and
H-alpha, can be used to improve the magnetic field constraints, under
conditions of high electrical conductivity. Such work is possible only with
time series datasets from two-dimensional spectroscopic instruments under
conditions of good seeing.


  A central goal of cryptography is Secure Multi-party Computation (MPC), where
$n$ parties desire to compute a function of their joint inputs without letting
any party learn about the inputs of its peers. Unfortunately, it is well-known
that MPC guaranteeing output delivery to every party is infeasible when a
majority of the parties are malicious. In fact, parties operating over a
point-to-point network (i.e. without access to a broadcast channel) cannot even
reach an agreement on the output when more than one third of the parties are
malicious (Lamport, Shostak, and Pease, JACM 1980).
  Motivated by this infeasibility in the point-to-point model, Goldwasser and
Lindell (J. Cryptol 2005) introduced a definition of MPC that does not require
agreement, referred to as MPC with selective abort. Under this definition, any
party may abort the protocol if they detect malicious behavior. They showed
that MPC with selective abort is feasible for any number of malicious parties
by implementing a broadcast functionality with abort.
  While the model of MPC with abort has attracted much attention over the
years, little is known about its communication complexity over point-to-point
networks. In this work, we study the communication complexity of MPC with abort
and devise nearly-optimal communication efficient protocols in this model.
Namely, we prove trade-offs between the number of honest parties $h$, the
communication complexity, and the locality of the protocols. Here, locality is
a bound on the number of peers with which each party must communicate.


  In the hypersphere soliton model (HSM), we study the geometrical inner
structures and the ensuing charge distributions of the nucleons by exploiting
the aspect of the HSM where the hypersphere soliton is described by an extended
object possessing the parameter $\lambda$ $(0\le\lambda<\infty)$ which
corresponds to the radial distance from the center of $S^{3}$ to the foliation
leaves of the hypersphere soliton. To do this, we investigate the foliation and
topology related with geometry on a hypersphere described by
$(\mu,\theta,\phi)$. Exploiting the so-called scanning algorithm we study
geometrical relations between spherical shell foliation leave on a northern
hemi-hypersphere $S^{3}_{+}$ and that on a flat equatorial solid sphere $E^{3}$
which contains the center of $S^{3}$. We then elucidate the physical meaning of
$\mu$ in $S^{3}$ of radius $\lambda$ by showing that $\mu$ plays the role of an
auxiliary angle to fix the radius $\lambda\sin\mu$ of the $S^{2}$ spherical
shell sharing the center of $S^{3}(=S^{2}\times S^{1})$, at a given angle
$\mu$. Next, using the charge density profiles of nucleons with $\mu$
dependence, we construct the nucleon fractional charges of spherically
symmetric and nontrivial distributions. In the HSM we note that the proton and
neutron charges do not leak out from the hypersphere soliton, and the positive
and negative charges in the neutron are confined inside and outside its core,
respectively. Explicitly we predict the fractional volumes and charges of the
neutron. The proton and neutron are shown to be described by a topological
structure of two Hopf-linked M\"obius strip type twist circles in $S^{3}$. We
also note that the characteristic ratio of the hypersphere volume to the
corresponding solid sphere one is given by a geometrical invariant related with
hyper-compactness.


  Dialog management (DM) is a crucial component in a task-oriented dialog
system. Given the dialog history, DM predicts the dialog state and decides the
next action that the dialog agent should take. Recently, dialog policy learning
has been widely formulated as a Reinforcement Learning (RL) problem, and more
works focus on the applicability of DM. In this paper, we survey recent
advances and challenges within three critical topics for DM: (1) improving
model scalability to facilitate dialog system modeling in new scenarios, (2)
dealing with the data scarcity problem for dialog policy learning, and (3)
enhancing the training efficiency to achieve better task-completion performance
. We believe that this survey can shed a light on future research in dialog
management.


  Filamentous cyanobacteria growing in media with insufficient fixed nitrogen
differentiate some cells into heterocysts, which fix nitrogen for the remaining
vegetative cells. Transport studies have shown both periplasmic and cytoplasmic
connections between cells that could transport fixed-nitrogen along the
filament. Two experiments have imaged fixed-nitrogen distributions along
filaments. In 1974,Wolk et al found a peaked concentration of fixed-nitrogen at
heterocysts using autoradiographic techniques. In contrast, in 2007, Popa et al
used nanoSIMS to show large dips at the location of heterocysts, with a
variable but approximately level distribution between them. With an integrated
model of fixed-nitrogen transport and cell growth, we recover the results of
both Wolk et al and of Popa et al using the same model parameters. To do this,
we account for immobile incorporated fixed-nitrogen and for the differing
durations of labeled nitrogen fixation that occurred in the two experiments.
The variations seen by Popa et al are consistent with the effects of
cell-by-cell variations of growth rates, and mask diffusive gradients. We are
unable to rule out a significant amount of periplasmic fN transport.


  We consider the thermodynamics of a uniformly charged polyelectrolyte with
harmonic bonds. For such a system there is at high temperatures an approximate
scaling of global properties like the end-to-end distance and the interaction
energy with the chain-length divided by the temperature. This scaling is broken
at low temperatures by the ultraviolet divergence of the Coulomb potential. By
introducing a renormalization of the strength of the nearest- neighbour
interaction the scaling is restored, making possible an efficient blocking
method for emulating very large polyelectrolytes using small systems. The high
temperature behaviour is well reproduced by the analytical high-$T$ expansions
even for fairly low temperatures and system sizes. In addition, results from
low-$T$ expansions, where the coefficients have been computed numerically, are
presented. These results approximate well the corresponding Monte Carlo results
at realistic temperatures. A corresponding analysis of screened chains is
performed. The situation here is complicated by the appearance of an additional
parameter, the screening length. A window is found in parameter space, where
scaling holds for the end-to-end distance. This window corresponds to
situations where the range of the potential interpolates between the bond
length and the size of the chain. This scaling behaviour, which is verified by
Monte Carlo results, is consistent with Flory scaling. Also for the screened
chain a blocking approach can be devised, that performs well for low
temperatures, whereas the low-$T$ expansion is inaccurate at realistic
temperatures.


  As the first step to determine disk mass-to-light ratios for normal spiral
galaxies, we present the results of an imaging survey for planetary nebulae
(PNe) in six nearby, face-on systems: IC 342, M74 (NGC 628), M83 (NGC 5236),
M94 (NGC 4736), NGC 5068, and NGC 6946. Using Blanco/Mosaic II and WIYN/OPTIC,
we identify 165, 153, 241, 150, 19, and 71 PN candidates, respectively, and use
the Planetary Nebula Luminosity Function (PNLF) to obtain distances. For M74
and NGC 5068, our distances of 8.6 +/- 0.3 Mpc and 5.4 +0.2/-0.4 Mpc are the
first reliable estimates to these objects; for IC 342 (3.5 +/- 0.3 Mpc), M83
(4.8 +/- 0.1 Mpc), M94 (4.4 +0.1/-0.2 Mpc), and NGC 6946 (6.1 +/- 0.6 Mpc) our
values agree well with those in the literature. In the larger systems, we find
no evidence for any systematic change in the PNLF with galactic position,
though we do see minor field-to-field variations in the luminosity function. In
most cases, these changes do not affect the measurement of distance, but in one
case the fluctuations result in a ~0.2 mag shift in the location of the PNLF
cutoff. We discuss the possible causes of these small-scale changes, including
internal extinction in the host galaxies and age/metallicity changes in the
underlying stellar population.


  The proton-proton momentum correlation functions ($C_{pp}(q)$) for
kinematically complete decay channels of $^{23}$Al $\rightarrow$ p + p +
$^{21}$Na and $^{22}$Mg $\rightarrow$ p + p + $^{20}$Ne have been measured at
the RIKEN RI Beam Factory. From the very different correlation strength of
$C_{pp}(q)$ for $^{23}$Al and $^{22}$Mg, the source size and emission time
information were extracted from the $C_{pp}(q)$ data by assuming a Gaussian
source profile in the correlation function calculation code (CRAB). The results
indicated that the mechanism of two-proton emission from $^{23}$Al was mainly
sequential emission, while that of $^{22}$Mg was mainly three-body simultaneous
emission. By combining our earlier results of the two-proton relative momentum
and the opening angle, it is pointed out that the mechanism of two-proton
emission could be distinguished clearly.


  We report on the teleoperation system DronePick which provides remote object
picking and delivery by a human-controlled quadcopter. The main novelty of the
proposed system is that the human user continuously gets the visual and haptic
feedback for accurate teleoperation. DronePick consists of a quadcopter
equipped with a magnetic grabber, a tactile glove with finger motion tracking
sensor, hand tracking system, and the Virtual Reality (VR) application. The
human operator teleoperates the quadcopter by changing the position of the
hand. The proposed vibrotactile patterns representing the location of the
remote object relative to the quadcopter are delivered to the glove. It helps
the operator to determine when the quadcopter is right above the object. When
the "pick" command is sent by clasping the hand in the glove, the quadcopter
decreases its altitude and the magnetic grabber attaches the target object. The
whole scenario is in parallel simulated in VR. The air flow from the quadcopter
and the relative positions of VR objects help the operator to determine the
exact position of the delivered object to be picked. The experiments showed
that the vibrotactile patterns were recognized by the users at the high
recognition rates: the average 99% recognition rate and the average 2.36s
recognition time. The real-life implementation of DronePick featuring object
picking and delivering to the human was developed and tested.


  We analyze a general class of reversible aggregate-reorganization processes.
These processes are shown to exhibit globally attracting equilibrium
distributions, which are \textit{universal}, i.e. identical for large classes
of models. Furthermore, the analysis implies that for studies of equilibrium
properties of \textit{any} such process, computationally expensive
reorganization dynamics such as random walks can be replaced by more efficient,
yet simpler methods. As a particular application, our results explain the
recent observation of the formation of similar fractal aggregates from
different initial structures by diffusive reorganization [Filoche and Sapoval,
Phys. Rev. Lett. 85, 5118 (2000)].


  A homotopy analogue of the notion of a triangular Lie bialgebra is proposed
with a goal of extending the basic notions of theory of quantum groups to the
context of homotopy algebras and, in particular, introducing a homotopical
generalization of the notion of a quantum group, or quantum$_\infty$-group.


  Analyzing the physical and chemical properties of single DNA based molecular
machines such as polymerases and helicases often necessitates to track stepping
motion on the length scale of base pairs. Although high resolution instruments
have been developed that are capable of reaching that limit, individual steps
are oftentimes hidden by experimental noise which complicates data processing.
Here, we present an effective two-step algorithm which detects steps in a high
bandwidth signal by minimizing an energy based model (Energy based step-finder,
EBS). First, an efficient convex denoising scheme is applied which allows
compression to tupels of amplitudes and plateau lengths. Second, a
combinatorial optimization algorithm formulated on a graph is used to assign
steps to the tupel data while accounting for prior information. Performance of
the algorithm was tested on poissonian stepping data simulated based on
published kinetics data of RNA Polymerase II (Pol II). Comparison to existing
step-finding methods shows that EBS is superior both in speed and precision.
Moreover, the capability to detect backtracked intervals in experimental data
of Pol II as well as to detect stepping behavior of the Phi29 DNA packaging
motor is demonstrated.


  Regular expressions with backreferences (regex, for short), as supported by
most modern libraries for regular expression matching, have an NP-complete
matching problem. We define a complexity parameter of regex, called active
variable degree, such that regex with this parameter bounded by a constant can
be matched in polynomial-time. Moreover, we formulate a novel type of
determinism for regex (on an automaton-theoretic level), which yields the class
of memory-deterministic regex that can be matched in time O(|w|p(|r|)) for a
polynomial p (where r is the regex and w the word). Natural extensions of these
concepts lead to properties of regex that are intractable to check.


  This paper documents a new feature of international trade: the increase in
the number of low-value transactions. Using Spanish data, we show that the
share of low-value transactions in the total number of transactions increased
from 9% to 61% in exports and from 14% to 54% in imports between 1997 and 2023.
The increase in the number of low-value trade transactions is related to the
rise in e-commerce and direct-to-customer sales facilitated by online retail
platforms. In the case of exports, the increase in the number of low-value
transactions is also explained by the fast-fashion strategy followed by
clothing firms.


  In this paper we present a new analysis of energy consumption in cellular
networks. We focus on the distribution of energy consumed by a base station for
one isolated cell. We first define the energy consumption model in which the
consumed energy is divided into two parts: The additive part and the broadcast
part. The broadcast part is the part of energy which is oblivious of the number
of mobile stations but depends on the farthest terminal, for instance, the
energy effort necessary to maintain the beacon signal. The additive part is due
to the communication power which depends on both the positions, mobility and
activity of all the users. We evaluate by closed form expressions the mean and
variance of the consumed energy. Our analytic evaluation is based on the
hypothesis that mobiles are distributed according to a Poisson point process.
We show that the two parts of energy are of the same order of magnitude and
that substantial gain can be obtained by power control. We then consider the
impact of mobility on the energy consumption. We apply our model to two case
studies: The first one is to optimize the cell radius from the energetic point
of view, the second one is to dimension the battery of a base station in sites
that do not have access to permanent power supply.


  We study the rotations of a heavy string (helicoseir) about a vertical axis
with one free endpoint and with arbitrary density, under the action of the
gravitational force. We show that the problem can be transformed into a
nonlinear eigenvalue equation, as in the uniform case. The eigenmodes of this
equation represent equilibrium configurations of the rotating string in which
the shape of the string doesn't change with time. As previously proved by
Kolodner for the homogenous case, the occurrence of new modes of the nonlinear
equation is tied to the spectrum of the corresponding linear equation. We have
been able to generalize this result to a class of densities $\rho(s) = \gamma
(1-s)^{\gamma-1}$, which includes the homogenous string as a special case
($\gamma=1$).
  We also show that the solutions to the nonlinear eigenvalue equation (NLE)
for an arbitrary density are orthogonal and that a solution of this equation
with a given number of nodes contains solutions of a different helicoseir, with
a smaller number of nodes. Both properties hold also for the homogeneous case
and had not been established before.