  The Milky Way is believed to host hundreds of millions of quiescent
stellar-mass black holes (BHs). In the last decade, some of these objects have
been potentially uncovered via gravitational microlensing events. All these
detections resulted in a degeneracy between the velocity and the mass of the
lens. This degeneracy has been lifted, for the first time, with the recent
astrometric microlensing detection of OB110462. However, two independent
studies reported very different lens mass for this event. Sahu et al. (2022)
inferred a lens mass of 7.1 $\pm$ 1.3 Msun, consistent with a BH, while Lam et
al. (2022) inferred 1.6-4.2 Msun, consistent with either a neutron star or a
BH. Here, we study the landscape of isolated BHs formed in the field. In
particular, we focus on the mass and center-of-mass speed of four
sub-populations: isolated BHs from single-star origin, disrupted BHs of
binary-star origin, main-sequence stars with a compact object companion, and
double compact object mergers. Our model predicts that most ($\gtrsim$ 70%)
isolated BHs in the Milky Way are of binary origin. However, non-interactions
lead to most massive BHs ($\gtrsim$ 15-20 Msun) being predominantly of single
origin. Under the assumption that OB110462 is a free-floating compact object we
conclude that it is more likely to be a BH originally belonging to a binary
system. Our results suggest that low-mass BH microlensing events can be useful
to understand binary evolution of massive stars in the Milky Way, while
high-mass BH lenses can be useful to probe single stellar evolution.


  Parallel and series nucleation are the basic elements of the complex
nucleation process when two saddle points exist on the free-energy landscape.
It is pointed out that the nucleation rates follow formulas similar to those of
parallel and series connection of resistors or conductors in an electric
circuit. Necessary formulas to calculate individual nucleation rates at the
saddle points and the total nucleation rate are summarized and the extension to
the more complex nucleation process is suggested.


  We investigate the galactic disk distribution of a sample of planetary
nebulae characterised in terms of their mid-infrared spectral features. The
total number of galactic disk PNe with 8-13mum spectra is brought up to 74 with
the inclusion of 24 new objects, whose spectra we present for the first time.
54 PNe have clearly identified warm dust emission features, and form a sample
which we use to construct the distribution of the C/O chemical balance in
galactic disk PNe. The dust emission features complement the information on the
progenitor masses brought by the gas-phase N/O ratios: PNe with unidentified
infrared emission bands have the highest N/O ratios, while PNe with the
silicate signature have either very high N enrichment or close to none, and SiC
emission features coincide with a range of moderate N-enrichments. We find a
trend for a decreasing proportion of O-rich PNe towards the third and fourth
galactic quadrants. Two independent distance scales confirmed that the
proportion of O-rich PNe decreases from 30+-9% inside the solar circle, to
14+-7% outside. PNe with warm dust are also the youngest. PNe with no warm dust
are uniformly distributed in C/O and N/O ratios, and do not appear to be
confined to C/O~1. They also have higher 6cm fluxes, as expected from more
evolved PNe. We show that the IRAS fluxes are a good representation of the
bolometric flux for warm-dust PNe. The requirement F(12um)>0.5Jy should probe a
good portion of the galactic disk, and the dominant selection effects are
rooted in the PN catalogues.


  We have developed a new method of an earthquake-resistant design to support
conventional aseismic designs using acoustic metamaterials. We suggest a simple
and practical method to reduce the amplitude of a seismic wave exponentially.
Our device is an attenuator of a seismic wave. Constructing a cylindrical
shell-type waveguide that creates a stop-band for the seismic wave, we convert
the wave into an evanescent wave for some frequency range without touching the
building we want to protect.


  Given the phenomenological success of the Nambu-Jona-Lasinio model in
describing the meson physics in the low energy limit, it is tempting to find
the fully relativistically structured nucleon solution in the same model under
the similar approximation employed in the mesonic sector. To achieve this goal
we need to solve a relativistic Faddeev equation. The factorizability of the
two-body T-matrix reduces the three-body Faddeev equation to a tractable
two-body Bethe-Salpeter equation. The reduced equation is then solved
numerically. Our result indicates that the nucleon consists of three loosely
bound constituent quarks.


  55 Cnc e is an ultra-short period super-Earth transiting a Sun-like star.
Previous observations in the optical range detected a time-variable flux
modulation that is phased with the planetary orbital period, whose amplitude is
too large to be explained by reflected light and thermal emission alone. The
goal of the study is to investigate the origin of the variability and timescale
of the phase-curve modulation in 55 Cnc e. To this end, we used the
CHaracterising ExOPlanet Satellite (CHEOPS), whose exquisite photometric
precision provides an opportunity to characterise minute changes in the phase
curve from one orbit to the next. CHEOPS observed 29 individual visits of 55
Cnc e between March 2020 and February 2022. Based on these observations, we
investigated the different processes that could be at the origin of the
observed modulation. In particular, we built a toy model to assess whether a
circumstellar torus of dust driven by radiation pressure and gravity might
match the observed flux variability timescale. We find that the phase-curve
amplitude and peak offset of 55 Cnc e do vary between visits. The sublimation
timescales of selected dust species reveal that silicates expected in an
Earth-like mantle would not survive long enough to explain the observed
phase-curve modulation. We find that silicon carbide, quartz, and graphite are
plausible candidates for the circumstellar torus composition because their
sublimation timescales are long. The extensive CHEOPS observations confirm that
the phase-curve amplitude and offset vary in time.We find that dust could
provide the grey opacity source required to match the observations. However,
the data at hand do not provide evidence that circumstellar material with a
variable grain mass per unit area causes the observed variability. Future
observations with the James Webb Space Telescope promise exciting insights into
this iconic super-Earth.


  Mid-dimensional $(A,B,A)$ and $(B,B,B)$-branes in the moduli space of flat
$G_{\mathbb C}$-connections appearing from finite group actions on compact
Riemann surfaces are studied. The geometry and topology of these spaces is then
described via the corresponding Higgs bundles and Hitchin fibrations.


  In this paper, we introduce the notion of the strong Rees property (SRP) for
$\mathfrak{m}$-primary ideals of a Noetherian local ring and prove that any
power of the maximal ideal $\mathfrak{m}$ has its property if the associated
graded ring $G$ of $\mathfrak{m}$ satisfies $\text{depth} \ G \ge 2$. As its
application, we characterize two-dimensional excellent normal local domains so
that $\mathfrak{m}$ is a $p_g$-ideal. Finally we ask what
$\mathfrak{m}$-primary ideals have SRP and state a conjecture which
characterizes the case when $\mathfrak{m}^n$ are the only ideals which have
SRP.


  This paper presents deep high quality photometry of globular cluster (GC)
systems belonging to five early-type galaxies covering a range of mass and
environment. Photometric data were obtained with the Gemini North and Gemini
South telescopes in the filter passbands g', r', and i'. The combination of
these filters with good seeing conditions allows an excellent separation
between GC candidates and unresolved field objects. Bimodal GC colour
distributions are found in all five galaxies. Most of the GC systems appear
bimodal even in the (g' -r') vs (r' -i') plane. A population of
resolved/marginally resolved GC and Ultra Compact Dwarf candidates was found in
all the galaxies. A search for the so-called "blue tilt" in the
colour-magnitude diagrams reveals that NGC 4649 clearly shows that phenomenon
although no conclusive evidence was found for the other galaxies in the sample.
This "blue tilt" translates into a mass-metallicity relation given by Z \propto
M^0.28\pm0.03 . This dependence was found using a new empirical (g' -i') vs
[Z/H] relation which relies on an homogeneous sample of GC colours and
metallicities. This paper also explores the radial trends in both colour and
surface density for the blue (metal-poor) and red (metal-rich) GC
subpopulations. As usual, the red GCs show a steeper radial distribution than
the blue ones. Evidence of galactocentric colour gradients is found in some of
the GC systems, being more significant for the two S0 galaxies in the sample.
Red GC subpopulations show similar colours and gradients to the galaxy halo
stars in their inner region. A GC mean colour-galaxy luminosity relation,
consistent with [Z/H] \propto L_B ^0.26\pm0.08, is present for the red GCs. An
estimate of the total GC populations and specific frequency SN values is
presented for NGC 3115, NGC 3379, NGC 3923 and NGC 4649.


  The spectrum of a one-dimensional pseudospin-one Hamiltonian with a
three-component potential is studied for two configurations: (i) all the
potential components are constants over the whole coordinate space and (ii) the
profile of some components is of a rectangular form. In case (i), it is
illustrated how the structure of three (lower, middle and upper) bands depends
on the configuration of potential strengths including the appearance of flat
bands at some special values of these strengths. In case (ii), the set of two
equations for finding bound states is derived. The spectrum of bound-state
energies is shown to depend crucially on the configuration of potential
strengths. Each of these configurations is specified by a single strength
parameter $V$. The bound-state energies are calculated as functions of the
strength $V$ and a one-point approach is developed realizing correspondent
point interactions. For different potential configurations, the energy
dependence on the strength $V$ is described in detail, including its one-point
approximation. From a whole variety of bound-state spectra, four characteristic
types are singled out.


  Reconfigurable Intelligent Surface (RIS) has become a popular technology to
improve the capability of a THz multiuser Multi-input multi-output (MIMO)
communication system. THz wave characteristics, on the other hand, restrict THz
beam coverage on RIS when using a uniform planar array (UPA) antenna. In this
study, we propose a dynamic RIS subarray structure to improve the performance
of a THz MIMO communication system. In more details, an RIS is divided into
several RIS subarrays according to the number of users. Each RIS subarray is
paired with a user and only reflects beams to the corresponding user. Based on
the structure of RIS, we first propose a weighted minimum mean square error -
RIS local search (WMMSE-LS) scheme, which requires that each RIS element has
limited phase shifts. To improve the joint beamforming performance, we further
develop an adaptive Block Coordinate Descent(BCD)-aided algorithm, an iterative
optimization method. Numerical results demonstrate the effectiveness of the
dynamic RIS subarray structure and the adaptive BCD-aided joint beamforming
scheme and also show the merit of our proposed system.


  We say that an algebra A is periodic if it has a periodic projective
resolution as an (A,A)-bimodule. We show that any self-injective algebra of
finite representation type is periodic. To prove this, we first apply the
theory of smash products to show that for a finite Galois covering B --> A, B
is periodic if and only if A is. In addition, when A has finite representation
type, we build upon results of Buchweitz to show that periodicity passes
between A and its stable Auslander algebra. Finally, we use Asashiba's
classification of the derived equivalence classes of self-injective algebras of
finite type to compute bounds for the periods of these algebras, and give an
application to stable Calabi-Yau dimensions.


  We consider the paths of a Gaussian random process $x(t)$, $x(0)=0$ not
exceeding a fixed positive level over a large time interval $(0,T)$, $T\gg 1$.
The probability $p(T)$ of such event is frequently a regularly varying function
at $\infty$ with exponent $\theta$. In applications this parameter can provide
information on fractal properties of processes that are subordinate to
$x(\cdot)$. For this reason the estimation of $\theta$ is an important
theoretical problem. Here, we consider the process $x(t)$ whose derivative is
fractional Brownian motion with self-similarity parameter $0<H<1$. For this
case we produce new computational evidence in favor of the relations $\log
p(T)=-\theta \log T(1+o(1))$ and $\theta =H(1-H)$. The estimates of $\theta$
are to within 0.01 in the range $0.1\le H\le 0.9$. An analytical result for the
problem in hand is known for the markovian case alone, i.e., for $H=1/2$. We
point out other statistics of $x(t)$ whose small values have probabilities of
the same order as $p(T)$ in the $\log$ scale.


  A matrix is called totally negative (totally non-positive) of order $k$, if
all its minors of size at most $k$ are negative (non-positive). The objective
of this article is to provide several novel characterizations of total
negativity via the (a) sign non-reversal property, (b) variation diminishing
property, and (c) Linear Complementarity Problem. More strongly, each of these
three characterizations uses a single test vector. As an application of the
sign non-reversal property, we study the interval hull of two rectangular
matrices. In particular, we identify two matrices $C^\pm(A,B)$ in the interval
hull of matrices $A$ and $B$ that test total negativity of order $k$,
simultaneously for the entire interval hull. We also show analogous
characterizations for totally non-positive matrices. These novel
characterizations may be considered similar in spirit to fundamental results
characterizing totally positive matrices by Brown--Johnstone--MacGibbon [J.
Amer. Statist. Assoc. 1981] (see also Gantmacher--Krein, 1950),
Choudhury--Kannan--Khare [Bull. London Math. Soc., 2021] and Choudhury [Bull.
London Math. Soc., 2022]. Finally using a 1950 result of Gantmacher--Krein, we
show that totally negative/non-positive matrices can not be detected by
(single) test vectors from orthants other than the open bi-orthant that have
coordinates with alternating signs, via the sign non-reversal property or the
variation diminishing property.


  We study graded traces of vectors in free bosonic vertex operator algebras
and lattice vertex operator algebras. We show in particular that trace
functions in these two theories always have the shape f(q)/\eta(q)^d where f(q)
is quasi-modular in the case of d free bosons, and modular (i.e., a sum of
holomorphic modular forms of various weights) in the case of theories based on
a lattice L of rank d. We also show how spherical harmonic polynomials with
respect to L are related to primary fields in lattice theories.


  We present an analysis of the late time X-ray emission (URCA-3) connected
with GRB 031203 and SN 2003lw.


  Predicting metro passenger flow precisely is of great importance for dynamic
traffic planning. Deep learning algorithms have been widely applied due to
their robust performance in modelling non-linear systems. However, traditional
deep learning algorithms completely discard the inherent graph structure within
the metro system. Graph-based deep learning algorithms could utilise the graph
structure but raise a few challenges, such as how to determine the weights of
the edges and the shallow receptive field caused by the over-smoothing issue.
To further improve these challenges, this study proposes a model based on
GraphSAGE with an edge weights learner applied. The edge weights learner
utilises socially meaningful features to generate edge weights. Hypergraph and
temporal exploitation modules are also constructed as add-ons for better
performance. A comparison study is conducted on the proposed algorithm and
other state-of-art graph neural networks, where the proposed algorithm could
improve the performance.


  The conventional approach to fixed-order perturbative QCD predictions is
based on an arbitrary choice of the renormalization scale, together with an
arbitrary range. This {\it ad hoc} assignment of the renormalization scale
causes the coefficients of the QCD running coupling at each perturbative order
to be strongly dependent on the choice of both the renormalization scale and
the renormalization scheme. However, such ambiguities are not necessary, since
as a basic requirement of renormalization group invariance (RGI), any physical
observable must be independent of the choice of both the renormalization scheme
and the renormalization scale. In fact, if one uses the {\it Principle of
Maximum Conformality} (PMC) to fix the renormalization scale, the coefficients
of the pQCD series match the series of conformal theory, and they are thus
scheme independent. It has been found that the elimination of the scale and
scheme ambiguities at all orders relies heavily on how precisely we know the
analytic form of the QCD running coupling $\alpha_s$. In this review, we
summarize the known properties of the QCD running coupling and its recent
progresses, especially for its behavior within the asymptotic region. We also
summarize the current progress on the PMC and some of its typical applications,
showing to what degree the conventional renormalization scheme-and-scale
ambiguities can be eliminated after applying the PMC. We also compare the PA
approach for the conventional scale-dependent pQCD series and the PMC
scale-independent conformal series. We observe that by using the conformal
series, the PA approach can provide a more reliable estimate of the magnitude
of the uncalculated terms. And if the conformal series for an observable has
been calculated up to $n_{\rm th}$-order level, then the $[N/M]=[0/n-1]$-type
PA series provides an important estimate for the higher-order terms.


  We present a systematic investigation of jet production at hadron colliders
from a phenomenological point of view, with the dual aim of providing a
validation of theoretical calculations and guidance to future determinations of
parton distributions (PDFs). We account for all available inclusive jet and
dijet production measurements from ATLAS and CMS at 7 and 8 TeV by including
them in a global PDF determination, and comparing to theoretical predictions at
NNLO QCD supplemented by electroweak (EW) corrections. We assess the
compatibility of the PDFs, specifically the gluon, obtained before and after
inclusion of the jet data. We compare the single-inclusive jet and dijet
observables in terms of perturbative behaviour upon inclusion of QCD and EW
corrections, impact on the PDFs, and global fit quality. In the
single-inclusive case, we also investigate the role played by different scale
choices and the stability of the results upon changes in modelling of the
correlated experimental systematics.


  Pixel-level crack segmentation is widely studied due to its high impact on
building and road inspections. While recent studies have made significant
improvements in accuracy, they typically heavily depend on pixel-level crack
annotations, which are time-consuming to obtain. In earlier work, we proposed
to reduce the annotation cost bottleneck by reformulating the crack
segmentation problem as a weakly-supervised problem -- i.e. the annotation
process is expedited by sacrificing the annotation quality. The loss in
annotation quality was remedied by refining the inference with per-pixel
brightness values, which was effective when the pixel brightness distribution
between cracks and non-cracks are well separated, but struggled greatly for
lighter-colored cracks as well as non-crack targets in which the brightness
distribution is less articulated. In this work, we propose an annotation
refinement approach which takes advantage of the fact that the regions falsely
annotated as cracks have similar local visual features as the background.
Because the proposed approach is data-driven, it is effective regardless of a
dataset's pixel brightness profile. The proposed method is evaluated on three
crack segmentation datasets as well as one blood vessel segmentation dataset to
test for domain robustness, and the results show that it speeds up the
annotation process by factors of 10 to 30, while the detection accuracy stays
at a comparable level.


  In this letter we propose a scheme for the preparation of steady
entanglements in bosonic dissipative networks. We describe its implementation
in a system of coupled cavities interacting with an engineered reservoir built
up of three-level atoms. Emblematic bipartite ($Bell$ and $NOON$) and
multipartite $W$-class states can be produced with high fidelity and purity.


  The decay $K^+ \to \pi^+\nu\bar{\nu}$ is highly suppressed in the Standard
Model (SM), while its rate can be predicted with minimal theoretical
uncertainty. The branching ratio (BR) for this decay is thus a sensitive probe
of the flavor sector of the SM; its measurement, however, is a significant
experimental challenge. The primary goal of the NA62 experiment is to measure
${\rm BR}(K^+ \to \pi^+\nu\bar{\nu})$ with $\sim$10% precision. This will
require the observation of $10^{13}$ $K^+$ decays in the experiment's fiducial
volume, as well as the use of high-performance systems for precision tracking,
particle identification, and photon vetoing. These aspects of the experiment
will also allow NA62 to carry out a rich program of searches for lepton flavor
and/or number violating $K^+$ decays. Part of the experimental apparatus was
commissioned during a technical run in 2012; installation continues and data
taking is expected to begin in late 2014. The physics prospects and the status
of the NA62 experiment are reviewed.


  In this article, we study the linearity of the minimal free resolution of
powers of facets ideals of simplicial trees. We give a complete
characterization of simplicial trees for which (some) power of its facet ideal
has a linear resolution. We calculate the regularity of the $t$-path ideal of a
perfect rooted tree. We also obtain an upper bound for the regularity of the
$t$-path ideal of a rooted tree. We give a procedure to calculate the
regularity of powers of facet ideals of simplicial trees. As a consequence of
this result, we study the regularity of powers of $t$-path ideals of rooted
trees. We pose a regularity upper bound conjecture for facet ideals of
simplicial trees, which is as follows: if $\Delta$ is a $d$-dimensional
simplicial tree, then $\reg(I(\Delta)^s) \leq (d+1)(s-1)+\reg(I(\Delta))$ for
all $s \geq 1$. We prove this conjecture for some special classes of simplicial
trees.


  In this research note, we start exploring the influence of the narrow line
region (NLR) on the optical/UV continuum polarization of active galactic nuclei
(AGN). We have upgraded our previous 3-component model of a thermal Seyfert
nucleus that was composed of an equatorial, optically thin electron disc, a
circumnuclear dusty torus, and a pair of collimated, optically thin electron
winds (Marin et al.2012b). We have added a dusty extension with low optical
depth to the outflows to account for continuum scattering and absorption inside
the NLR. A spectropolarimetric comparison between our AGN models with and
without NLR reprocessing is carried out. It turns out that the NLR can alter
and even suppress the observed polarization dichotomy between type-1 and type-2
AGN. For type-2 AGN, it also significantly decreases the expected percentage of
polarization and alters its spectral shape. While the NLR makes it more
difficult to reproduce the observed polarization in type-1 objects, it helps to
explain spectropolarimetry observations of type-2 objects. Further studies
including clumpy media need to be carried out.


  We investigate the small-scale static configurations of K-mouflage models
defined by a general function $K(\chi)$ of the kinetic terms. The fifth force
is screened by the nonlinear K-mouflage mechanism if $K'(\chi)$ grows
sufficiently fast for large negative $\chi$. In the general non-spherically
symmetric case, the fifth force is not aligned with the Newtonian force. For
spherically symmetric static matter density profiles, the results depend on the
potential function $W_{-}(y) = y K'(-y^2/2)$, which must be monotonically
increasing to $+\infty$ for $y \geq 0$ to guarantee the existence of a single
solution throughout space for any matter density profile. Small radial
perturbations around these static profiles propagate as traveling waves with a
velocity greater than the speed of light. Starting from vanishing initial
conditions for the scalar field and for a time-dependent matter density
corresponding to the formation of an overdensity, we numerically check that the
scalar field converges to the static solution. If $W_{-}$ is bounded, for
high-density objects there are no static solutions throughout space, but one
can still define a static solution restricted to large radii. Our dynamical
study shows that the scalar field relaxes to this static solution at large
radii, whereas spatial gradients keep growing with time at smaller radii. If
$W_{-}$ is not bounded but non-monotonic, there is an infinite number of
discontinuous static solutions but they are not physical and these models are
not theoretically sound. Such K-mouflage scenarios provide an example of
theories that can appear viable at the cosmological level, for the cosmological
background and perturbative analysis, while being meaningless at a nonlinear
level for small-scale configurations. This shows the importance of small-scale
nonlinear analysis of screening models.


  On a compact n-dimensional manifold, it has been conjectured that a critical
point metric of the total scalar curvature, restricted to the space of metrics
with constant scalar curvature of unit volume, will be Einstein. This
conjecture was proposed in 1984 by Besse, but has yet to be proved. In this
paper, we prove that if the manifold with the critical point metric has
harmonic curvature, then it is isometric to a standard sphere.


  This note is an extended review of the book Error and Inference, edited by
Deborah Mayo and Aris Spanos, about their frequentist and philosophical
perspective on testing of hypothesis and on the criticisms of alternatives like
the Bayesian approach.


  In this paper we review the construction of the thermal bosonic string and
$D$-brane in the framework of the Thermo Field Dynamics (TFD). We briefly
recall the well-known light-cone quantization of the bosonic string in the
conformal gauge in flat space-time. Then we give a bird's eye view of the
fundamental concepts of the TFD. Also, we present the thermalization of the
bosonic string and the construction of the thermal D-brane boundary state.
Finally, we show the calculation of the entropy of the thermal open string
states with all boundary conditions and the entropy of the thermal D-brane
state.


  Let $G$ be a graph, and $v\in V(G)$ and $S\subseteq V(G)\backslash v$ of size
at least $k$. An important result on graph connectivity due to Perfect states
that, if $v$ and $S$ are $k$-linked, then a $(k-1)$-link between a vertex $v$
and $S$ can be extended to a $k$-link between $v$ and $S$ such that the
endvertices of the $(k-1)$-link are also the endvertices of the $k$-link. We
begin by proving a generalization of Perfect's result by showing that, if two
disjoint sets $S_1$ and $S_2$ are $k$-linked, then a $t$-link ($t< k$) between
two disjoint sets $S_1$ and $S_2$ can be extended to a $k$-link between $S_1$
and $S_2$ such that the endvertices of the $t$-link are preserved in the
$k$-link.
  Next, we are able to use these results to show that a 3-connected claw-free
graph always has a cycle passing through any given five vertices but avoiding
any other one specified vertex. We also show that this result is sharp by
exhibiting an infinite family of 3-connected claw-free graphs in which there is
no cycle containing a certain set of six vertices but avoiding a seventh
specified vertex. A direct corollary of our main result shows that, a
3-connected claw-free graph has a topological wheel minor $W_k$ with $k\le 5$
if and only if it has a vertex of degree at least $k$.
  Finally, we also show that a graph polyhedrally embedded in a surface always
has a cycle passing through any given three vertices but avoiding any other
specified vertex. The result is best possible in the sense that the polyhedral
embedding assumption is necessary, and there are infinitely many graphs
polyhedrally embedded in any surface having no cycle containing a certain set
of four vertices but avoiding a fifth specified vertex.


  Late Winter Lecture Notes, Short Course (10 hours) of Relativistic
Astrophysics held at the Department of Physics and Astronomy of the University
of Padova, March 13-17, 2017. Third version.


  In the commented paper, the authors declare an analogy with the quantum
mechanical pure states established through the application of the
high-dimensional combinatorial Laplacian considering that the simplicial
complex is in the pure state when it is formed by collection of the pure
states. In their work, besides giving a completely erroneous analogy for the
pure quantum mechanical state, which contradicts to very basic postulates of
quantum mechanic, the authors clearly fail to provide and explain mathematical
formalism behind their claims. Their intention is to rigorously prove that the
existence of opinion space in all considered cases consists of the pure quantum
states using incorrect normalization constant which does not produce trace
equal to one. In this comment we prove out that their claims are erroneous. In
order to show incorrectness of Maletic & Rajkovic model and conclusions we
calculated and examined connections between different combinatorial structures
of q- dimensional simplicial complexes and their Laplacian spectra and analyzed
resulting symmetric and positive semidefinite matrices in the context of the
density matrix of a quantum mechanical system. Importance of presented research
is to further develop accurate quantitative topological-based characterization
method for convertibility and distillation of density matrix.


  The Coupled Cavity Drift Tube Linac (CCDTL) used in the Accelerator for the
Production of Tritium (APT) is fully described elsewhere [1]. The modules are
composed of several machined and brazed segments that must account for the
accumulation of dimensional tolerances in the build up of the stack. In
addition, space requirements dictate that power fed to the accelerator cannot
be through the accelerating cavities. As well, we would like to remove a single
segment of the accelerator without removing additional segments. These
requirements combined with phasing relationships of the design and space
limitations have resulted in a different bridge coupling method used in the
module comprising 3-gap segments. The coupling method, phasing relationships
and other features that enhance the flexibility of the design will be
discussed.


  Repeated exposure to low-level blast may initiate a range of adverse health
problem such as traumatic brain injury (TBI). Although many studies
successfully identified genes associated with TBI, yet the cellular mechanisms
underpinning TBI are not fully elucidated. In this study, we investigated
underlying relationship among genes through constructing transcript Bayesian
networks using RNA-seq data. The data for pre- and post-blast transcripts,
which were collected on 33 individuals in Army training program, combined with
our system approach provide unique opportunity to investigate the effect of
blast-wave exposure on gene-gene interactions. Digging into the networks, we
identified four subnetworks related to immune system and inflammatory process
that are disrupted due to the exposure. Among genes with relatively high fold
change in their transcript expression level, ATP6V1G1, B2M, BCL2A1, PELI,
S100A8, TRIM58 and ZNF654 showed major impact on the dysregulation of the
gene-gene interactions. This study reveals how repeated exposures to traumatic
conditions increase the level of fold change of transcript expression and
hypothesizes new targets for further experimental studies.


  The correlation among the gene genealogies at different loci is crucial in
biology, yet challenging to understand because such correlation depends on many
factors including genetic linkage, recombination, natural selection and
population structure. Based on a diploid Wright-Fisher model with a single
mating type and partial selfing for a constant large population with size $N$,
we quantify the combined effect of genetic drift and two competing factors,
recombination and selfing, on the correlation of coalescence times at two
linked loci for samples of size two. Recombination decouples the genealogies at
different loci and decreases the correlation while selfing increases the
correlation. We obtain explicit asymptotic formulas for the correlation for
four scaling scenarios that depend on whether the selfing probability and the
recombination probability are of order $O(1/N)$ or $O(1)$ as $N$ tends to
infinity. Our analytical results confirm that the asymptotic lower bound in
[King, Wakeley, Carmi (Theor. Popul. Biol. 2018)] is sharp when the loci are
unlinked and when there is no selfing, and provide a number of new formulas for
other scaling scenarios that have not been considered before. We present
asymptotic results for the variance of Tajima's estimator of the population
mutation rate for infinitely many loci as $N$ tends to infinity. When the
selfing probability is of order $O(1)$ and is equal to a positive constant $s$
for all $N$ and if the samples at both loci are in the same individual, then
the variance of the Tajima's estimator tends to $s/2$ (hence remains positive)
even when the recombination rate, the number of loci and the population size
all tend to infinity.


  The dilute A$_3$ lattice model in regime 2 is in the universality class of
the Ising model in a magnetic field. Here we establish directly the existence
of an E$_8$ structure in the dilute A$_3$ model in this regime by expressing
the 1-dimensional configuration sums in terms of fermionic sums which
explicitly involve the E$_8$ root system. In the thermodynamic limit, these
polynomial identities yield a proof of the E$_8$ Rogers--Ramanujan identity
recently conjectured by Kedem {\em et al}.
  The polynomial identities also apply to regime 3, which is obtained by
transforming the modular parameter by $q\to 1/q$. In this case we find an
A$_1\times\mbox{E}_7$ structure and prove a Rogers--Ramanujan identity of
A$_1\times\mbox{E}_7$ type. Finally, in the critical $q\to 1$ limit, we give
some intriguing expressions for the number of $L$-step paths on the A$_3$
Dynkin diagram with tadpoles in terms of the E$_8$ Cartan matrix. All our
findings confirm the E$_8$ and E$_7$ structure of the dilute A$_3$ model found
recently by means of the thermodynamic Bethe Ansatz.


  The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector.
Its usage of 1000 metric tons of D$_{2}$O as target allows the SNO detector to
make a solar-model independent test of the neutrino oscillation hypothesis by
simultaneously measuring the solar $\nu_{e}$ flux and the total flux of all
active neutrino species. Solar neutrinos from the decay of $^{8}$B have been
detected at SNO by the charged-current (CC) interaction on the deuteron and by
the elastic scattering (ES) of electrons. While the CC reaction is sensitive
exclusively to $\nu_{e}$, the ES reaction also has a small sensitivity to
$\nu_{\mu}$ and $\nu_{\tau}$. In this paper, recent solar neutrino results from
the SNO experiment are presented. It is demonstrated that the solar flux from
$^{8}$B decay as measured from the ES reaction rate under the no-oscillation
assumption is consistent with the high precision ES measurement by the
Super-Kamiokande experiment. The $\nu_{e}$ flux deduced from the CC reaction
rate in SNO differs from the Super-Kamiokande ES results by 3.3$sigma$. This is
evidence for an active neutrino component, in additional to $\nu_{e}$, in the
solar neutrino flux. These results also allow the first experimental
determination of the total active $^{8}$B neutrino flux from the Sun, and is
found to be in good agreement with solar model predictions.


  The feedback capacity of the stationary Gaussian additive noise channel has
been open, except for the case where the noise is white. Here we find the
feedback capacity of the stationary first-order moving average additive
Gaussian noise channel in closed form. Specifically, the channel is given by
$Y_i = X_i + Z_i,$ $i = 1, 2, ...,$ where the input $\{X_i\}$ satisfies a power
constraint and the noise $\{Z_i\}$ is a first-order moving average Gaussian
process defined by $Z_i = \alpha U_{i-1} + U_i,$ $|\alpha| \le 1,$ with white
Gaussian innovations $U_i,$ $i = 0,1,....$
  We show that the feedback capacity of this channel is $-\log x_0,$ where
$x_0$ is the unique positive root of the equation $ \rho x^2 = (1-x^2) (1 -
|\alpha|x)^2,$ and $\rho$ is the ratio of the average input power per
transmission to the variance of the noise innovation $U_i$. The optimal coding
scheme parallels the simple linear signalling scheme by Schalkwijk and Kailath
for the additive white Gaussian noise channel -- the transmitter sends a
real-valued information-bearing signal at the beginning of communication and
subsequently refines the receiver's error by processing the feedback noise
signal through a linear stationary first-order autoregressive filter. The
resulting error probability of the maximum likelihood decoding decays
doubly-exponentially in the duration of the communication. This feedback
capacity of the first-order moving average Gaussian channel is very similar in
form to the best known achievable rate for the first-order
\emph{autoregressive} Gaussian noise channel studied by Butman, Wolfowitz, and
Tiernan, although the optimality of the latter is yet to be established.


  Combining the cosmological requirement on dark matter with the recent BNL g-2
measurement it is argued that, within the mSUGRA framework, the preferred
region for SUSY mass parameters falls well inside the area covered by the
future linear colliders under consideration for right handed sleptons and of
the 2 lightest neutralinos. The coverage for the lightest chargino and left
handed sleptons is also favoured but with smaller confidence.


  We study theoretically how the initial cosmological conditions establish the
dependence of galaxy properties on the environment. First, we adopt the linear
tidal torque theory according to which the angular momentum of a proto-galaxy
is generated at first order by the misalignment between the proto-galaxy
inertia tensor and the local tidal tensor. Then, we quantify analytically the
degree of the misalignment between the two tensors, and show quantitatively
that it increases as the density of the environment decreases. It implies that
the proto-galaxies forming in the lower density regions should end up with
having higher angular momentum than those in the higher density regions, which
is consistent with recent numerical finding that the void and field galaxies
have higher spin parameters than the cluster galaxies. Since the galaxy angular
momentum plays a role of developing a disk-like structure and hindering the
star-formation, our theoretical insight provides an answer to such fundamental
observational question as why the large void galaxies have young stellar
populations and high specific star formation rate, which was not explained by
the previous morphology-density relation.


  We present EasyASR, a distributed machine learning platform for training and
serving large-scale Automatic Speech Recognition (ASR) models, as well as
collecting and processing audio data at scale. Our platform is built upon the
Machine Learning Platform for AI of Alibaba Cloud. Its main functionality is to
support efficient learning and inference for end-to-end ASR models on
distributed GPU clusters. It allows users to learn ASR models with either
pre-defined or user-customized network architectures via simple user interface.
On EasyASR, we have produced state-of-the-art results over several public
datasets for Mandarin speech recognition.


  The ambient solar wind flows and fields influence the complex propagation
dynamics of coronal mass ejections in the interplanetary medium and play an
essential role in shaping Earth's space weather environment. A critical
scientific goal in the space weather research and prediction community is to
develop, implement and optimize numerical models for specifying the large-scale
properties of solar wind conditions at the inner boundary of the heliospheric
model domain. Here we present an adaptive prediction system that fuses
information from in situ measurements of the solar wind into numerical models
to better match the global solar wind model solutions near the Sun with
prevailing physical conditions in the vicinity of Earth. In this way, we
attempt to advance the predictive capabilities of well-established solar wind
models for specifying solar wind speed, including the Wang-Sheeley-Arge (WSA)
model. In particular, we use the Heliospheric Upwind eXtrapolation (HUX) model
for mapping the solar wind solutions from the near-Sun environment to the
vicinity of Earth. In addition, we present the newly developed Tunable HUX
(THUX) model which solves the viscous form of the underlying Burgers equation.
We perform a statistical analysis of the resulting solar wind predictions for
the time 2006-2015. The proposed prediction scheme improves all the
investigated coronal/heliospheric model combinations and produces better
estimates of the solar wind state at Earth than our reference baseline model.
We discuss why this is the case, and conclude that our findings have important
implications for future practice in applied space weather research and
prediction.


  In this paper, we study negacyclic codes of odd length and of length $2^k$
over the ring $R=\mathbb{Z}_4+u\mathbb{Z}_4$, $u^2=0$. We give the complete
structure of negacyclic codes for both the cases. We have obtained a minimal
spanning set for negacyclic codes of odd lengths over $R$. A necessary and
sufficient condition for negacyclic codes of odd lengths to be free is
presented. We have determined the cardinality of negacyclic codes in each case.
We have obtained the structure of the duals of negacyclic codes of length $2^k$
over $R$ and also characterized self-dual negacyclic codes of length $2^k$ over
$R$.


  We investigate the electronic properties of semi-metallic (12,0) carbon
nanotubes in the presence of a variety of mono-, di- and hexa-vacancy defects,
by using first principle DFT combined with non-equilibrium Green's function
technique. We show that defect states related to the vacancies hybridize with
the extended states of the nanotubes to modify the band edge, and change the
energy gap, resulting from the curvature effect. As a consequence, the nanotube
conductance is not a monotonic function of the defect size and geometry.
Paradoxically, hexa-vacancy nanotubes have higher conductance than di-vacancy
nanotubes, which is due to the presence of mid-gap states originating from the
defect, thereby enhancing the conductance.


  Retrieving images from large and varied repositories using visual contents
has been one of major research items, but a challenging task in the image
management community. In this paper we present an efficient approach for
region-based image classification and retrieval using a fast multi-level neural
network model. The advantages of this neural model in image classification and
retrieval domain will be highlighted. The proposed approach accomplishes its
goal in three main steps. First, with the help of a mean-shift based
segmentation algorithm, significant regions of the image are isolated.
Secondly, color and texture features of each region are extracted by using
color moments and 2D wavelets decomposition technique. Thirdly the multi-level
neural classifier is trained in order to classify each region in a given image
into one of five predefined categories, i.e., "Sky", "Building", "SandnRock",
"Grass" and "Water". Simulation results show that the proposed method is
promising in terms of classification and retrieval accuracy results. These
results compare favorably with the best published results obtained by other
state-of-the-art image retrieval techniques.


  In this article we introduce theory and algorithms for learning discrete
representations that take on a lattice that is embedded in an Euclidean space.
Lattice representations possess an interesting combination of properties: a)
they can be computed explicitly using lattice quantization, yet they can be
learned efficiently using the ideas we introduce in this paper, b) they are
highly related to Gaussian Variational Autoencoders, allowing designers
familiar with the latter to easily produce discrete representations from their
models and c) since lattices satisfy the axioms of a group, their adoption can
lead into a way of learning simple algebras for modeling binary operations
between objects through symbolic formalisms, yet learn these structures also
formally using differentiation techniques. This article will focus on laying
the groundwork for exploring and exploiting the first two properties, including
a new mathematical result linking expressions used during training and
inference time and experimental validation on two popular datasets.


  The Renyi entropy plays an essential role in quantum information theory. We
study the continuity estimation of the Renyi entropy. An inequality relating
the Renyi entropy difference of two quantum states to their trace norm distance
is derived. This inequality is shown to be tight in the sense that equality can
be attained for every prescribed value of the trace norm distance. It includes
the sharp Fannes inequality for von Neumann entropy as a special case.


  We develop a distributed stochastic gradient descent algorithm for solving
non-convex optimization problems under the assumption that the local objective
functions are twice continuously differentiable with Lipschitz continuous
gradients and Hessians. We provide sufficient conditions on step-sizes that
guarantee the asymptotic mean-square convergence of the proposed algorithm. We
apply the developed algorithm to a distributed supervised-learning problem, in
which a set of networked agents collaboratively train their individual neural
nets to recognize handwritten digits in images. Results indicate that all
agents report similar performance that is also comparable to the performance of
a centrally trained neural net. Numerical results also show that the proposed
distributed algorithm allows the individual agents to recognize the digits even
though the training data corresponding to all the digits is not locally
available to each agent.


  Capturing users' precise preferences is a fundamental problem in large-scale
recommender system. Currently, item-based Collaborative Filtering (CF) methods
are common matching approaches in industry. However, they are not effective to
model dynamic and evolving preferences of users. In this paper, we propose a
new sequential deep matching (SDM) model to capture users' dynamic preferences
by combining short-term sessions and long-term behaviors. Compared with
existing sequence-aware recommendation methods, we tackle the following two
inherent problems in real-world applications: (1) there could exist multiple
interest tendencies in one session. (2) long-term preferences may not be
effectively fused with current session interests. Long-term behaviors are
various and complex, hence those highly related to the short-term session
should be kept for fusion. We propose to encode behavior sequences with two
corresponding components: multi-head self-attention module to capture multiple
types of interests and long-short term gated fusion module to incorporate
long-term preferences. Successive items are recommended after matching between
sequential user behavior vector and item embedding vectors. Offline experiments
on real-world datasets show the superior performance of the proposed SDM.
Moreover, SDM has been successfully deployed on online large-scale recommender
system at Taobao and achieves improvements in terms of a range of commercial
metrics.


  In this paper a novel approach to hide sound files in a digital image is
proposed and implemented such that it becomes difficult to conclude about the
existence of the hidden data inside the image. In this approach, we utilize the
rightmost k-LSB of pixels in an image to embed MP3 sound bits into a pixel. The
pixels are so chosen that the distortion in image would be minimized due to
embedding. This requires comparing all the possible permutations of pixel
values, which may would lead to exponential time computation. To speed up this,
Cuckoo Search (CS) could be used to find the most optimal solution. The
advantage of using proposed CS is that it is easy to implement and is very
effective at converging in relatively less iterations/generations.


  In this paper we study the properties of black holes and scalarons in
Einstein gravity when it is minimally coupled to a scalar field $\phi$ with an
asymmetric potential $V(\phi)$, constructed in [Phys. Rev. D \textbf{73}
(2006), 084002] a few decades ago. $V(\phi)$ has been applied in the cosmology
to describe the quantum tunneling process from the false vacuum to the true
vacuum and contains a local maximum, a local minimum (false vacuum) and a
global minimum (true vacuum). In particular we focus on the asymptotically flat
solutions, which can be constructed by fixing appropriately the local minimum
of $V$. A branch of hairy black holes solutions emerge from the Schwarzschild
black hole, and we study the domain of existence of such configurations. They
can reach to a particle-like solution in the small horizon limit, i.e. the
scalarons. We study the stability of black holes and scalarons, showing that
all of them are unstable under radial perturbations.


  We present the first results on the complexity of the reconfiguration of
vertex separators under the three most popular rules: token addition/removal,
token jumping, and token sliding. We show that, aside from some trivially
negative instances, the first two rules are equivalent to each other and that,
even if only on a subclass of bipartite graphs, TJ is not equivalent to the
other two unless $\mathsf{NP} = \mathsf{PSPACE}$; we do this by showing a
relationship between separators and independent sets in this subclass of
bipartite graphs. In terms of polynomial time algorithms, we show that every
class with a polynomially bounded number of minimal vertex separators admits an
efficient algorithm under token jumping, then turn our attention to two classes
that do not meet this condition: $\{3P_1, diamond\}$-free and series-parallel
graphs. For the first, we describe a novel characterization, which we use to
show that reconfiguring vertex separators under token jumping is always
possible and that, under token sliding, it can be done in polynomial time; for
series-parallel graphs, we also prove that reconfiguration is always possible
under TJ and exhibit a polynomial time algorithm to construct the
reconfiguration sequence.


  We take the Dyson-Schwinger equation (DSE) approach of QCD to study the phase
transition and the equation of state of cold dense matter. Besides the bare
vertex and Gauss gluon model, we take into account an improved truncation
scheme, the CLRQ vertex and infrared-constant gluon model. For the dynamical
chiral symmetry breaking solution of the DSE, we require that the emergence of
quark number density to be at the chemical potential for the nuclear liquid-gas
phase transition to take place, by incorporating a chemical potential dependent
modification factor to the gluon model. The result shows that our modified
scheme can not only describe the phase transition of the cold dense matter well
but also the deduced equation of state of the matter can describe the recent
astronomical observations consistently.


  The solution of problems in physics is often facilitated by a change of
variables. In this work we present neural transformations to learn symmetries
of Hamiltonian mechanical systems. Maintaining the Hamiltonian structure
requires novel network architectures that parametrize symplectic
transformations. We demonstrate the utility of these architectures by learning
the structure of integrable models. Our work exemplifies the adaptation of
neural transformations to a family constrained by more than the condition of
invertibility, which we expect to be a common feature of applications of these
methods.


  We report on the results of medium-resolution spectroscopy of GRS 1915+105 in
the H and K band using the 8m VLT at ESO. We clearly identify absorption
bandheads from CO12 and CO13. Together with other features this results in a
classification of the donor as a K-M III star.


  The eigenvalue problem for the p-Laplace operator with Robin boundary
condition is considered in this paper. A Faber-Krahn type inequality is proved.
More precisely, it is shown that amongst all the domains of fixed volume, the
ball has the smallest first eigenvalue.


  Unsupervised Graph Domain Adaptation (UGDA) aims to transfer knowledge from a
labelled source graph to an unlabelled target graph in order to address the
distribution shifts between graph domains. Previous works have primarily
focused on aligning data from the source and target graph in the representation
space learned by graph neural networks (GNNs). However, the inherent
generalization capability of GNNs has been largely overlooked. Motivated by our
empirical analysis, we reevaluate the role of GNNs in graph domain adaptation
and uncover the pivotal role of the propagation process in GNNs for adapting to
different graph domains. We provide a comprehensive theoretical analysis of
UGDA and derive a generalization bound for multi-layer GNNs. By formulating GNN
Lipschitz for k-layer GNNs, we show that the target risk bound can be tighter
by removing propagation layers in source graph and stacking multiple
propagation layers in target graph. Based on the empirical and theoretical
analysis mentioned above, we propose a simple yet effective approach called
A2GNN for graph domain adaptation. Through extensive experiments on real-world
datasets, we demonstrate the effectiveness of our proposed A2GNN framework.


  Robust test statistics for the two-way MANOVA based on the minimum covariance
determinant (MCD) estimator are proposed as alternatives to the classical
Wilks' Lambda test statistics which are well known to be very sensitive to
outliers as they are based on classical normal theory estimates of generalized
variances. The classical Wilks' Lambda statistics are robustified by replacing
the classical estimates by highly robust and efficient reweighted MCD
estimates. Further, Monte Carlo simulations are used to evaluate the
performance of the new test statistics under various designs by investigating
their finite sample accuracy, power, and robustness against outliers. Finally,
these robust test statistics are applied to a real data example.


  We propose a projected gradient dynamical system as a model for a bargaining
scheme for an asset for which the two interested agents have personal
valuations which do not initially coincide. The personal valuations are formed
using subjective beliefs concerning the future states of the world and the
reservation prices are calculated using expected utility theory. The agents are
not rigid concerning their subjective probabilities and are willing to update
them under the pressure to reach finally an agreement concerning the asset. The
proposed projected dynamical system, on the space of probability measures,
provides a model for the evolution of the agents beliefs during the bargaining
period and is constructed so that agreement is reached under the minimum
possible deviation of both agents from their initial beliefs. The convergence
results are shown using techniques from convex dynamics and Lyapunov function
theory.


  Quality Diversity (QD) algorithms such as MAP-Elites are a class of
optimisation techniques that attempt to find a set of high-performing points
from an objective function while enforcing behavioural diversity of the points
over one or more interpretable, user chosen, feature functions.
  In this paper we propose the Bayesian Optimisation of Elites (BOP-Elites)
algorithm that uses techniques from Bayesian Optimisation to explicitly model
both quality and diversity with Gaussian Processes. By considering user defined
regions of the feature space as 'niches' our task is to find the optimal
solution in each niche. We propose a novel acquisition function to
intelligently choose new points that provide the highest expected improvement
to the ensemble problem of identifying the best solution in every niche. In
this way each function evaluation enriches our modelling and provides insight
to the whole problem, naturally balancing exploration and exploitation of the
search space. The resulting algorithm is very effective in identifying the
parts of the search space that belong to a niche in feature space, and finding
the optimal solution in each niche. It is also significantly more sample
efficient than simpler benchmark approaches. BOP-Elites goes further than
existing QD algorithms by quantifying the uncertainty around our predictions
and offering additional illumination of the search space through surrogate
models.


  The Krein-Milman theorem (1940) states that every convex compact subset of a
Hausdorfflocally convex topological space, is the closed convex hull of its
extreme points. In 1963, Ky Fan extended the Krein-Milman theorem to the
general framework of $\Phi$-convexity. Under general conditions on the class of
functions $\Phi$, the Krein-Milman-Ky Fan theorem asserts then, that every
compact $\Phi$-convex subset of a Hausdorff space, is the $\Phi$-convex hull of
its $\Phi$-extremal points. We prove in this paper that, in the metrizable case
the situation is rather better. Indeed, we can replace the set of
$\Phi$-extremal points by the smaller subset of $\Phi$-exposed points. We
establish under general conditions on the class of functions $\Phi$, that every
$\Phi$-convex compact metrizable subset of a Hausdorff space, is the
$\Phi$-convex hull of its $\Phi$-exposed points. As a consequence we obtain
that each convex weak compact metrizable (resp. convex weak$^*$ compact
metrizable) subset of a Banach space (resp. of a dual Banach space), is the
closed convex hull of its exposed points (resp. the weak$^*$ closed convex hull
of its weak$^*$ exposed points). This result fails in general for compact
$\Phi$-convex subsets that are not metrizable.


  We present an optical and X-ray study of the quasar QSO 0117-2837. It
exhibits an interesting combination of optical and X-ray properties: Despite
its extremely steep observed X-ray spectrum (Gamma_x ~ -4 when fit by a simple
powerlaw), its Balmer lines are fairly broad. A two-component Gaussian fit to
H_beta yields FWHM_{Hbeta, broad} ~ 4000 km/s, and places QSO 0117-2837 in the
`zone of avoidance' in the FWHM_{Hbeta}-Gamma_x diagram.
  A time variability analysis shows that QSO 0117-2837 is another case of
Narrow-line Sy1 galaxy (NLSy1 hereafter) which does not show any X-ray
variability during the observation.
  The results are discussed in view of the NLSy1 character of QSO 0117-2837.


  This article reports quasi-continuous transiting events towards WD 1054-226
at d=36.2 pc and V=16.0 mag, based on simultaneous, high-cadence,
multi-wavelength imaging photometry using ULTRACAM over 18 nights from 2019 to
2020 March. The predominant period is 25.02 h, and corresponds to a circular
orbit with blackbody Teq = 323 K, where a planetary surface can nominally
support liquid water. The light curves reveal remarkable night-to-night
similarity, with changes on longer timescales, and lack any transit-free
segments of unocculted starlight. The most pronounced dimming components occur
every 23.1 min -- exactly the 65th harmonic of the fundamental period -- with
depths of up to several per cent, and no evident color dependence. Myriad
additional harmonics are present, as well as at least two transiting features
with independent periods. High-resolution optical spectra are consistent with
stable, photospheric absorption by multiple, refractory metal species, with no
indication of circumstellar gas. Spitzer observations demonstrate a lack of
detectable dust emission, suggesting that the otherwise hidden circumstellar
disk orbiting WD 1054-226 may be typical of polluted white dwarfs, and only
detected via favorable geometry. Future observations are required to constrain
the orbital eccentricity, but even if periastron is near the Roche limit,
sublimation cannot drive mass loss in refractory parent bodies, and collisional
disintegration is necessary for dust production.


  We investigate the capabilities of transfer learning in the area of
structural health monitoring. In particular, we are interested in damage
detection for concrete structures. Typical image datasets for such problems are
relatively small, calling for the transfer of learned representation from a
related large-scale dataset. Past efforts of damage detection using images have
mainly considered cross-domain transfer learning approaches using pre-trained
IMAGENET models that are subsequently fine-tuned for the target task. However,
there are rising concerns about the generalizability of IMAGENET
representations for specific target domains, such as for visual inspection and
medical imaging. We, therefore, evaluate a combination of in-domain and
cross-domain transfer learning strategies for damage detection in bridges. We
perform comprehensive comparisons to study the impact of cross-domain and
in-domain transfer, with various initialization strategies, using six publicly
available visual inspection datasets. The pre-trained models are also evaluated
for their ability to cope with the extremely low-data regime. We show that the
combination of cross-domain and in-domain transfer persistently shows superior
performance specially with tiny datasets. Likewise, we also provide visual
explanations of predictive models to enable algorithmic transparency and
provide insights to experts about the intrinsic decision logic of typically
black-box deep models.


  Thermodynamics connects our knowledge of the world to our capability to
manipulate and thus to control it. This crucial role of control is exemplified
by the third law of thermodynamics, Nernst's unattainability principle, which
states that infinite resources are required to cool a system to absolute zero
temperature. But what are these resources and how should they be utilized? And
how does this relate to Landauer's principle that famously connects information
and thermodynamics? We answer these questions by providing a framework for
identifying the resources that enable the creation of pure quantum states. We
show that perfect cooling is possible with Landauer energy cost given infinite
time or control complexity. However, such optimal protocols require complex
unitaries generated by an external work source. Restricting to unitaries that
can be run solely via a heat engine, we derive a novel Carnot-Landauer limit,
along with protocols for its saturation. This generalizes Landauer's principle
to a fully thermodynamic setting, leading to a unification with the third law
and emphasizes the importance of control in quantum thermodynamics.


  Quantifying the interdisciplinarity of a research is a relevant problem in
the evaluative bibliometrics. The concept of interdisciplinarity is ambiguous
and multidimensional. Thus, different measures of interdisciplinarity have been
propose in the literature. However, few studies have proposed interdisciplinary
metrics without previously defining classification sets, and no one use the
co-citation network for this purpose. In this study we propose an
interdisciplinary metric based on the co-citation network. This is a way to
define the publication's field without resorting to pre-defined classification
sets. We present a characterization of a publication's field and then we use
this definition to propose a new metric of the interdisciplinarity degree for
publications (papers) and journals as units of analysis. The proposed measure
has an aggregative property that makes it scalable from a paper individually to
a set of them (journal) without more than adding the numerators and
denominators in the proportions that define this new indicator. Moreover, the
aggregated value of two or more units is strictly among all the individual
values.


  This paper describes how to propagate wavefields for arbitrary numbers of
traditional time steps in a single step, called a superstep. We show how to
construct operators that accomplish this task for finite-difference time domain
schemes, including temporal first-order schemes in isotropic, anisotropic and
elastic media, as well as temporal second-order schemes for acoustic media.
This task is achieved by implementing a computational tradeoff differing from
traditional single step wavefield propagators by precomputing propagator
matrices for each model location for k timesteps (a superstep) and using these
propagator matrices to advance the wavefield k time steps at once. This
tradeoff separates the physics of the propagator matrix computation from the
computer science of wavefield propagation and allows each discipline to provide
their optimal modular solutions.


  Giant atoms -- quantum emitters that couple to light at multiple discrete
points -- are emerging as a new paradigm in quantum optics thanks to their many
promising properties, such as decoherence-free interaction. While most previous
work has considered giant atoms coupled to open continuous waveguides or a
single giant atom coupled to a structured bath, here we study the interaction
between two giant atoms mediated by a structured waveguide, e.g., a photonic
crystal waveguide. This environment is characterized by a finite energy band
and a band gap, which affect atomic dynamics beyond the Markovian regime. Here
we show that, inside the band, decoherence-free interaction is possible for
different atom-cavity detunings, but is degraded from the continuous-waveguide
case by time delay and other non-Markovian effects. Outside the band, where
atoms interact through the overlap of bound states, we find that giant atoms
can interact more strongly and over longer distances than small atoms for some
parameters -- for instance, when restricting the maximum coupling strength
achievable per coupling point. The results presented here may find applications
in quantum simulation and quantum gate implementation.


  We study the competition between local (bridging) and global condensation of
fluid in a chemically heterogeneous capillary slit made from two parallel
adjacent walls each patterned with a single stripe. Using a mesoscopic modified
Kelvin equation, which determines the shape of the menisci pinned at the stripe
edges in the bridge phase, we determine the conditions under which the local
bridging transition precedes capillary condensation as the pressure (or
chemical potential) is increased. Provided the contact angle of the stripe is
less than that of the outer wall we show that triple points, where evaporated,
locally condensed and globally condensed states all coexist are possible
depending on the value of the aspect ratio $a=L/H$ where $H$ is the stripe
width and $L$ the wall separation. In particular, for a capillary made from
completely dry walls patterned with completely wet stripes the condition for
the triple point occurs when the aspect ratio takes its maximum possible value
$8/\pi$. These predictions are tested using a fully microscopic classical
Density Functional Theory and shown to be remarkably accurate even for
molecularly narrow slits. The qualitative differences with local and global
condensation in heterogeneous cylindrical pores are also highlighted.


  (abbreviated) This article considers recent advances in the investigation of
the thermal and magnetic properties of integrable spin ladder models and their
applicability to the physics of real compounds. The ground state properties of
the integrable two-leg spin-1/2 and the mixed spin-(1/2,1) ladder models at
zero temperature are analyzed by means of the Thermodynamic Bethe Ansatz.
Solving the TBA equations yields exact results for the critical fields and
critical behaviour. The thermal and magnetic properties of the models are
investigated in terms of the recently introduced High Temperature Expansion
method, which is discussed in detail. It is shown that in the strong coupling
limit the integrable spin-1/2 ladder model exhibits three quantum phases: (i) a
gapped phase in the regime $H<H_{c1}$, (ii) a fully polarised phase for
$H>H_{c2}$, and (iii) a Luttinger liquid magnetic phase in the regime
$H_{c1}<H<H_{c2}$. The critical behaviour in the vicinity of the critical
points is of the Pokrovsky-Talapov type. The temperature-dependent thermal and
magnetic properties are directly evaluated from the exact free energy
expression and compared to known experimental results for a range of strong
coupling ladder compounds. Similar analysis of the mixed spin-(1/2,1) ladder
model reveals a rich phase diagram, with a 1/3 and a full saturation
magnetisation plateau within the strong antiferromagnetic rung coupling regime.
For weak rung coupling, the fractional magnetisation plateau is diminished and
a new quantum phase transition occurs. The phase diagram can be directly
deduced from the magnetisation curve obtained from the exact result derived
from the HTE. The thermodynamics of the spin-orbital model with different
single-ion anisotropies is also investigated.


  We report X-ray, optical, and near-infrared monitoring of the new X-ray
transient MAXI J1820$+$070 discovered with MAXI on 2018 March 11. Its X-ray
intensity reached $\sim 2$ Crab in 2--20 keV at the end of March, and then
gradually decreased until the middle of June. In this period, the X-ray
spectrum was described by Comptonization of the disk emission, with a photon
index of $\sim$1.5 and an electron temperature of $\sim$50 keV, which is
consistent with a black hole X-ray binary in the low/hard state. The electron
temperature and the photon index were slightly decreased and increased with
increasing flux, respectively. The source showed significant X-ray flux
variation on timescales of seconds. This short-term variation was found to be
associated with changes in the spectral shape, and the photon index became
slightly harder at higher fluxes. This suggests that the variation was produced
by a change in the properties of the hot electron cloud responsible for the
strong Comptonization. Modeling a multi-wavelength SED around the X-ray flux
peak at the end of March, covering the near-infrared to X-ray bands, we found
that the optical and near-infrared fluxes were likely contributed substantially
by the jet emission. Before this outburst, the source was never detected in the
X-ray band with MAXI (with a 3$\sigma$ upper limit of $\sim$0.2 mCrab in 4--10
keV, obtained from the 7-year data in 2009--2016), whereas weak optical and
infrared activity was found at their flux levels $\sim$3 orders of magnitude
lower than the peak fluxes in the outburst.


  How do we determine the mutational effects in exome sequencing data with
little or no statistical evidence? Can protein structural information fill in
the gap of not having enough statistical evidence? In this work, we answer the
two questions with the goal towards determining pathogenic effects of rare
variants in rare disease. We take the approach of determining the importance of
point mutation loci focusing on protein structure features. The proposed
structure-based features contain information about geometric, physicochemical,
and functional information of mutation loci and those of structural neighbors
of the loci. The performance of the structure-based features trained on 80\% of
HumDiv and tested on 20\% of HumDiv and on ClinVar datasets showed high levels
of discernibility in the mutation's pathogenic or benign effects: F score of
0.71 and 0.68 respectively using multi-layer perceptron. Combining structure-
and sequence-based feature further improve the accuracy: F score of 0.86
(HumDiv) and 0.75 (ClinVar). Also, careful examination of the rare variants in
rare diseases cases showed that structure-based features are important in
discerning importance of variant loci.


  We theoretically study a system composed by a waveguide and a moving quantum
emitter in the single excitation subspace, treating the emitter motional degree
of freedom quantum mechanically. We first characterize single-photon scattering
off a single moving quantum emitter, showing both nonreciprocal transmission
and recoil-induced reduction of the quantum emitter motional energy. We then
characterize the bound states within the bandgap, which display a
motion-induced asymmetric phase in real space. We also demonstrate how these
bound states form a continuous band with exotic dispersion relations. Finally,
we study the spontaneous emission of an initially excited quantum emitter with
various initial momentum distributions, finding strong deviations with respect
to the static emitter counterpart both in the occupation dynamics and in the
spatial distribution of the emitted photons. Our work extends the waveguide-QED
toolbox by including the quantum motional degree of freedom of emitters, whose
impact in the few-photon dynamics could be harnessed for quantum technologies.


  The combination of edge and cloud in the fog computing paradigm enables a new
breed of data-intensive applications. These applications, however, have to face
a number of fog-specific challenges which developers have to repetitively
address for every single application.
  In this paper, we propose a replication service specifically tailored to the
needs of data-intensive fog applications that aims to ease or eliminate
challenges caused by the highly distributed and heterogeneous environment fog
applications operate in. Furthermore, we present our prototypical
proof-of-concept implementation FBase that we have made available as open
source.


  We introduce region-based explanations (RbX), a novel, model-agnostic method
to generate local explanations of scalar outputs from a black-box prediction
model using only query access. RbX is based on a greedy algorithm for building
a convex polytope that approximates a region of feature space where model
predictions are close to the prediction at some target point. This region is
fully specified by the user on the scale of the predictions, rather than on the
scale of the features. The geometry of this polytope - specifically the change
in each coordinate necessary to escape the polytope - quantifies the local
sensitivity of the predictions to each of the features. These "escape
distances" can then be standardized to rank the features by local importance.
RbX is guaranteed to satisfy a "sparsity axiom," which requires that features
which do not enter into the prediction model are assigned zero importance. At
the same time, real data examples and synthetic experiments show how RbX can
more readily detect all locally relevant features than existing methods.


  In recent years, mobility models have been reconsidered based on findings by
analyzing some big datasets collected by GPS sensors, cellphone call records,
and Geotagging. To understand the fundamental statistical properties of the
frequency of serendipitous human encounters, we conducted experiments to
collect long-term data on human contact using short-range wireless
communication devices which many people frequently carry in daily life. By
analyzing the data we showed that the majority of human encounters occur
once-in-an-experimental-period: they are Ichi-go Ichi-e. We also found that the
remaining more frequent encounters obey a power-law distribution: they are
scale-free. To theoretically find the origin of these properties, we introduced
as a minimal human mobility model, Homesick L\'evy walk, where the walker
stochastically selects moving long distances as well as L\'evy walk or
returning back home. Using numerical simulations and a simple mean-field
theory, we offer a theoretical explanation for the properties to validate the
mobility model. The proposed model is helpful for evaluating long-term
performance of routing protocols in delay tolerant networks and mobile
opportunistic networks better since some utility-based protocols select nodes
with frequent encounters for message transfer.


  In this paper, we perform a comprehensive study of Lepton Flavor Violation
(LFV) in semileptonic transitions in the framework of an Effective Field Theory
with general flavor structure. We account for the Renormalization Group
Equations (RGEs), which induce non-trivial correlations between the different
types of LFV processes. In particular, we show that these loop effects are
needed to improve the bounds on several coefficients that are not efficiently
constrained at tree level. For illustration, we consider a few concrete
scenarios, with predominant couplings to third-generation quarks, and we
explore the correlations between the various tree- and loop-level constraints
on these models. As a by-product, we also provide expressions for several
semileptonic LFV meson decays by using the latest determinations of the
relevant hadronic form factors on the lattice.


  We propose a way of reasoning about minimal and maximal values of the weights
of transitions in a weighted transition system (WTS). This perspective induces
a notion of bisimulation that is coarser than the classic bisimulation: it
relates states that exhibit transitions to bisimulation classes with the
weights within the same boundaries. We propose a customized modal logic that
expresses these numeric boundaries for transition weights by means of
particular modalities. We prove that our logic is invariant under the proposed
notion of bisimulation. We show that the logic enjoys the finite model property
and we identify a complete axiomatization for the logic. Last but not least, we
use a tableau method to show that the satisfiability problem for the logic is
decidable.


  The fundamental task of general density estimation $p(x)$ has been of keen
interest to machine learning. In this work, we attempt to systematically
characterize methods for density estimation. Broadly speaking, most of the
existing methods can be categorized into either using: \textit{a})
autoregressive models to estimate the conditional factors of the chain rule,
$p(x_{i}\, |\, x_{i-1}, \ldots)$; or \textit{b}) non-linear transformations of
variables of a simple base distribution. Based on the study of the
characteristics of these categories, we propose multiple novel methods for each
category. For example we proposed RNN based transformations to model
non-Markovian dependencies. Further, through a comprehensive study over both
real world and synthetic data, we show for that jointly leveraging
transformations of variables and autoregressive conditional models, results in
a considerable improvement in performance. We illustrate the use of our models
in outlier detection and image modeling. Finally we introduce a novel data
driven framework for learning a family of distributions.


  The nature of the recently detected HE and VHE gamma-ray emission of Tycho's
supernova remnant (SNR) is studied. A nonlinear kinetic theory of cosmic ray
(CR) acceleration in supernova remnants (SNRs) is employed to investigate the
properties of Tycho's SNR and their correspondence to the existing experimental
data, taking into account that the ambient interstellar medium (ISM) is
expected to be clumpy. It is demonstrated that the overall steep gamma-ray
spectrum observed can be interpreted as the superposition of two spectra
produced by the CR proton component in two different ISM phases: The first
gamma-ray component, extending up to about $10^{14}$ eV, originates in the
diluted warm ISM, whereas the second component, extending up to 100 GeV, comes
from numerous dense, small-scale clouds embedded in this warm ISM. Given the
consistency between acceleration theory and the observed properties of the
nonthermal emission of Tycho's SNR, a very efficient production of nuclear CRs
in Tycho's SNR is established. The excess of the GeV gamma-ray emission due to
the clouds' contribution above the level expected in the case of a purely
homogeneous ISM, is inevitably expected in the case of type Ia SNe.


  I review the status of theoretical predictions for events containing a W or Z
boson and jets, one or more of which may include heavy quarks. Special
attention is paid to comparisons between different theoretical approaches and
with the latest experimental data.


  We study the optimal control of path-dependent McKean-Vlasov equations valued
in Hilbert spaces motivated by non Markovian mean-field models driven by
stochastic PDEs. We first establish the well-posedness of the state equation,
and then we prove the dynamic programming principle (DPP) in such a general
framework. The crucial law invariance property of the value function V is
rigorously obtained, which means that V can be viewed as a function on the
Wasserstein space of probability measures on the set of continuous functions
valued in Hilbert space. We then define a notion of pathwise measure
derivative, which extends the Wasserstein derivative due to Lions [41], and
prove a related functional It{\^o} formula in the spirit of Dupire [24] and Wu
and Zhang [51]. The Master Bellman equation is derived from the DPP by means of
a suitable notion of viscosity solution. We provide different formulations and
simplifications of such a Bellman equation notably in the special case when
there is no dependence on the law of the control.


  Resilience has become an emerging topic in various fields of academic
research. In spite of its widespread use, there remains conceptual confusion
over what resilience means particularly in multi-disciplinary studies including
the field of ICT and Development. With the potential of digital technology,
research is needed to critically question what key socio-institutional values
related to resilience are being strengthened, for what and for whom through the
different conceptualizations of resilience. In this study, we conduct an
interpretive case study on South Korea's response to the pandemic and construct
a chronological narrative to identify key aspects of digital resilience. We
identify agility, diversity, and plurality - enabled by active roles of various
stakeholders, including citizens, research communities, and private sector - as
keys to digital resilience to the pandemic. Findings from the case of South
Korea provide implications to ICT4D research while discussing how developing
countries, where a national single window platform is typically implemented
with greater level of homogeneity, achieve digital resilience with inclusive
innovation with plurality of diverse platforms.


  We present the results of X-ray observations of four bright transients
sources detected in the July 2004 XMM-Newton observations of the central bulge
of M31. Two X-ray sources, XMMU J004315.5+412440 and XMMU J004144.7+411110,
were discovered for the first time. Two other sources, CXOM31 J004309.9+412332
and CXOM31 J004241.8+411635, were previously detected by Chandra. The
properties of the sources suggest their identification with accreting binary
systems in M31. The X-ray spectra and variability of two sources, XMMU
J004144.7+411110 and CXOM31 J004241.8+411635, are similar to that of the
Galactic black hole transients, making them a good black hole candidates. The
X-ray source XMMU J004315.5+412440 demonstrates a dramatic decline of the X-ray
flux on a time scale of three days, and a remarkable flaring behavior on a
short time scales. The X-ray data on XMMU J004315.5+412440 and CXOM31
J004309.9+412332 suggest that they can be either black hole or neutron star
systems. Combining the results of 2000-2004 XMM observations of M31, we
estimate a total rate of the bright transient outbursts in the central region
of M31 to be 6-12 per year, in agreement with previous studies.


  The Internet infrastructure relies entirely on open standards for its routing
protocols. However, the majority of routers on the Internet are closed-source.
Hence, there is no straightforward way to analyze them. Specifically, one
cannot easily identify deviations of a router's routing functionality from the
routing protocol's standard. Such deviations (either deliberate or inadvertent)
are particularly important to identify since they may degrade the security or
resiliency of the network.
  A model-based testing procedure is a technique that allows to systematically
generate tests based on a model of the system to be tested; thereby finding
deviations in the system compared to the model. However, applying such an
approach to a complex multi-party routing protocol requires a prohibitively
high number of tests to cover the desired functionality. We propose efficient
and practical optimizations to the model-based testing procedure that are
tailored to the analysis of routing protocols. These optimizations allow to
devise a formal black-box method to unearth deviations in closed-source routing
protocols' implementations. The method relies only on the ability to test the
targeted protocol implementation and observe its output. Identification of the
deviations is fully automatic.
  We evaluate our method against one of the complex and widely used routing
protocols on the Internet -- OSPF. We search for deviations in the OSPF
implementation of Cisco. Our evaluation identified numerous significant
deviations that can be abused to compromise the security of a network. The
deviations were confirmed by Cisco. We further employed our method to analyze
the OSPF implementation of the Quagga Routing Suite. The analysis revealed one
significant deviation. Subsequent to the disclosure of the deviations some of
them were also identified by IBM, Lenovo and Huawei in their own products.


  The detection of differentially expressed (DE) genes is one of the most
commonly studied problems in bioinformatics. For example, the identification of
DE genes between distinct disease phenotypes is an important first step in
understanding and developing treatment drugs for the disease. It can also
contribute significantly to the construction of a discriminant rule for
predicting the class of origin of an unclassified tissue sample from a patient.
We present a novel approach to the problem of detecting DE genes that is based
on a test statistic formed as a weighted (normalized) cluster-specific contrast
in the mixed effects of the mixture model used in the first instance to cluster
the gene profiles into a manageable number of clusters. The key factor in the
formation of our test statistic is the use of gene-specific mixed effects in
the cluster-specific contrast. It thus means that the (soft) assignment of a
given gene to a cluster is not crucial. This is because in addition to class
differences between the (estimated) fixed effects terms for a cluster,
gene-specific class differences also contribute to the cluster-specific
contributions to the final form of the test statistic. The proposed test
statistic can be used where the primary aim is to rank the genes in order of
evidence against the null hypothesis of no DE. We also show how a P-value can
be calculated for each gene for use in multiple hypothesis testing where the
intent is to control the false discovery rate (FDR) at some desired level. With
the use of real and simulated data sets, we show that the proposed
contrast-based approach outperforms other methods commonly used for the
detection of DE genes both in a ranking context with lower proportion of false
discoveries and in a multiple hypothesis testing context with higher power for
a specified level of the FDR.


  It is desirable to observe synchronization of quantum systems in the quantum
regime, defined by low number of excitations and a highly non-classical steady
state of the self-sustained oscillator. Several existing proposals of observing
synchronization in the quantum regime suffer from the fact that the noise
statistics overwhelms synchronization in this regime. Here we resolve this
issue by driving a self-sustained oscillator with a squeezing Hamiltonian
instead of a harmonic drive and analyze this system in the classical and
quantum regime. We demonstrate that strong entrainment is possible for small
values of squeezing, and in this regime the states are non-classical.
Furthermore, we show that the quality of synchronization measured by the FWHM
of the power spectrum is enhanced with squeezing.


  Phrase localization is a task that studies the mapping from textual phrases
to regions of an image. Given difficulties in annotating phrase-to-object
datasets at scale, we develop a Multimodal Alignment Framework (MAF) to
leverage more widely-available caption-image datasets, which can then be used
as a form of weak supervision. We first present algorithms to model
phrase-object relevance by leveraging fine-grained visual representations and
visually-aware language representations. By adopting a contrastive objective,
our method uses information in caption-image pairs to boost the performance in
weakly-supervised scenarios. Experiments conducted on the widely-adopted
Flickr30k dataset show a significant improvement over existing
weakly-supervised methods. With the help of the visually-aware language
representations, we can also improve the previous best unsupervised result by
5.56%. We conduct ablation studies to show that both our novel model and our
weakly-supervised strategies significantly contribute to our strong results.


  This paper considers the problem of minimizing a differentiable function with
locally Lipschitz continuous gradient on the algebraic variety of real matrices
of upper-bounded rank. This problem is known to enable the formulation of
several machine learning and signal processing tasks such as collaborative
filtering and signal recovery. Several definitions of stationarity exist for
this nonconvex problem. Among them, Bouligand stationarity is the strongest
first-order necessary condition for local optimality. This paper proposes a
first-order algorithm that combines the well-known projected-projected gradient
descent map with a rank reduction mechanism and generates a sequence in the
variety whose accumulation points are Bouligand stationary. This algorithm
compares favorably with the three other algorithms known in the literature to
enjoy this stationarity property, regarding both the typical computational cost
per iteration and empirically observed numerical performance. A framework to
design hybrid algorithms enjoying the same property is proposed and illustrated
through an example.


  We demonstrate, that the main universal features of the low temperature
experimental $H-T$ phase diagram of CeCoIn5 and other heavy-fermion metals can
be well explained using Landau paradigm of quasiparticles. The main point of
our theory is that above quasiparticles form so-called fermion-condensate
state, achieved by a fermion condensation quantum phase transition (FCQPT).
When a heavy fermion liquid undergoes FCQPT, the fluctuations accompanying
above quantum critical point are strongly suppressed and cannot destroy the
quasiparticles. The comparison of our theoretical results with experimental
data on CeCoIn5 have shown that the electronic system of above substance
provides a unique opportunity to study the relationship between quasiparticles
properties and non-Fermi liquid behavior.


  Research on vehicular networking (V2X) security has produced a range of
security mechanisms and protocols tailored for this domain, addressing both
security and privacy. Typically, the security analysis of these proposals has
largely been informal. However, formal analysis can be used to expose flaws and
ultimately provide a higher level of assurance in the protocols.
  This paper focusses on the formal analysis of a particular element of
security mechanisms for V2X found in many proposals: the revocation of
malicious or misbehaving vehicles from the V2X system by invalidating their
credentials. This revocation needs to be performed in an unlinkable way for
vehicle privacy even in the context of vehicles regularly changing their
pseudonyms. The REWIRE scheme by Forster et al. and its subschemes BASIC and
RTOKEN aim to solve this challenge by means of cryptographic solutions and
trusted hardware.
  Formal analysis using the TAMARIN prover identifies two flaws with some of
the functional correctness and authentication properties in these schemes. We
then propose Obscure Token (OTOKEN), an extension of REWIRE to enable
revocation in a privacy preserving manner. Our approach addresses the
functional and authentication properties by introducing an additional key-pair,
which offers a stronger and verifiable guarantee of successful revocation of
vehicles without resolving the long-term identity. Moreover OTOKEN is the first
V2X revocation protocol to be co-designed with a formal model.


  Systematic investigations of 137Cs and 134Cs activity concentrations in
potatoes (Solanum tuberosum) for the post-Chernobyl period (1986-2005) in the
Republic of Croatia are summarized. The correlation between 137Cs activity
concentrations in fallout and potatoes, has been found to be very good, the
correlation coefficient being r2=0.88 with P(t) < 0.001 for 18 degrees of
freedom. As the radiocaesium levels in potatoes decreased exponentially, the
mean residence time of 137Cs in potatoes was estimated by fitting the measured
activity concentrations to the exponential curve. The mean residence time was
found to be 6.8 +/- 1.1 years, the standard deviation being estimated by the
Monte Carlo simulations. The initial observed 134Cs:137Cs activity ratio in
potatoes has been found to be quite variable, but slightly lesser than
theoretically predicted value of 0.5, calculated by applying the known
inventory of these radionuclides in the Chernobyl reactor to the equation for
the differential radioactive decay. This can be explained by presence of the
pre-Chernobyl 137Cs in soil that originated from nuclear fallout. The annual
effective doses received by 134Cs and 137Cs intake due to consumption of
potatoes estimated for an adult member of Croatian population were found to be
very small, as the per caput dose for the entire 1986 - 2005 period was
calculated to be about 2.9 mSv, 134Cs accounting approximately for 1/3 of the
entire dose. Therefore, after the Chernobyl accident consumption of potatoes
was not the critical pathway for human intake of radiocaesium from the
environment in Croatia.


  We prove, under certain conditions on $(\alpha,\beta)$, that each Schwartz
function $f$ such that $f(\pm n^{\alpha}) = \hat{f}(\pm n^{\beta}) = 0, \forall
n \ge 0$ must vanish identically, complementing a series of recent results
involving uncertainty principles, such as the pointwise interpolation formulas
by Radchenko and Viazovska and the Meyer-Guinnand construction of self-dual
crystaline measures.


  In this master thesis, we extend results from classical simple homotopy
theory to the world of stratified homotopy theory. To obtain a well-established
framework to work in, we prove a series of results on two model categories of
simplicial sets and topological spaces, both equipped with a notion of
filtration, introduced by Sylvain Douteau in his PHD thesis. In particular, we
show that there is a fully faithful embedding of homotopy categories from the
(finite) filtered simplicial into the filtered topological setting. We also use
these results to characterize the morphisms in the topological filtered
homotopy category between filtered spaces that are triangulable and stratified
in some very general sense as stratified homotopy classes of stratum preserving
maps. Then, moving on to simple homotopy theory, we propose a class of
combinatorial elementary expansions for filtered simplicial sets that
generalize both the classical ones as well as a class of stratified expansions
suggested by Banagl et al. We show that they fulfill a series of axioms,
suggested by Eckmann and Siebenmann for the construction of simple homotopy
theory. In doing so, we obtain a combinatorially defined Whitehead group and
torsion for filtered simplicial sets (and hence also for triangulable
stratified spaces). We then begin a detailed investigation of their formal
properties, proving for example that a Mayer-Vietoris formula holds. Next, we
apply our results on stratified homotopy theory to obtain a more topological
description of the Whitehead group and to generalize the Whitehead torsion to
arbitrary stratum preserving maps of triangulated filtered spaces. Finally, we
prove that our simple homotopy theory is a generalization of the classical one,
in the sense that it agrees with the latter when one considers trivially
filtered simplicial sets as CW-complexes.