title:
Search for a light-charged Higgs in a two-Higgs-doublet type II seesaw
  model at the LHC

abstract:
  A charged Higgs in the type II two-Higgs-doublet model (THDM) has been
bounded to be above a few hundred GeV by the radiative $B$ decays. A Higgs
triplet extension of the THDM not only provides an origin of neutrino masses
and a completely new doubly-charged Higgs decay pattern, but it also achieves a
light-charged Higgs with a mass of ${\cal O}(100)$ GeV through the new scalar
couplings in the scalar potential. It was found that these light-charged Higgs
decays depend on its mass $m_{H^\pm}$, $\tan\beta$, and mixing effect
$\sin\theta_\pm$: at $\tan\beta =1$, if $m_{H^\pm} > m_W + m_Z$, $\bar b b
W^\pm$, $W^\pm Z$, and $\tau \nu$ are the main decay modes; however, if
$m_{H^\pm} < m_W + m_Z$, the main decay modes are then $\bar b b W$ and $\tau
\nu$, and at $\tan\beta=30$, the $\tau \nu$ mode dominates the other decays.
When $m_t > m_{H^\pm} + m_b$, we found that the ATLAS and CMS recent upper
bounds on the product of $BR(t\to H^+ b)BR(H^+\to \tau^+ \nu)$ can be directly
applied and will give a strict constraint on the correlation of $m_{H^\pm}$ and
$\sin\theta_\pm$. If the upper bound of $BR(t\to H^+ b)BR(H^+\to \tau^+ \nu)$
is satisfied (escaped) for $m_t > (<) m_{H^\pm} + m_b$, it was found that the
significance of discovering the charged Higgs through $H^\pm \to W^\pm Z$ is
much lower than that through $H^\pm \to \bar b b W^\pm$. With a luminosity of
100 fb$^{-1}$ at $\sqrt{s}=13$ TeV and including the experimental bounds, the
significance of the $H^\pm \to \bar b b W^\pm$ signal can reach around $6.2
(2.4)\sigma$ for $m_{H^\pm} <(>) m_W + m_Z$.


title: Multimode directionality in all-dielectric metasurfaces

abstract:
  We demonstrate that spectrally diverse multiple magnetic dipole resonances
can be excited in all-dielectric structures lacking rotational symmetry, in
contrast to conventionally used spheres, disks or spheroids. Such multiple
magnetic resonances arise from hybrid Mie-Fabry-P\'{e}rot modes, and can
constructively interfere with induced electric dipole moments, thereby leading
to novel multi-frequency unidirectional scattering. Here we focus on elongated
dielectric nanobars, whose magnetic resonances can be spectrally tuned by their
aspect ratios. Based on our theoretical results, we suggest all-dielectric
multimode metasurfaces and verify them in proof-of-principle microwave
experiments. We also believe that the demonstrated property of multimode
directionality is largely responsible for the best efficiency of all-dielectric
metasurfaces that were recently shown to operate across multiple telecom bands.


title: Desiging Artificial Lieb Lattice on Metal Surface

abstract:
  Recently, several experiments have illustrated that metal surface electrons
can be manipulated to form a two dimensional (2D) lattice by depositing a
designer molecule lattice on metal surface. This offers a promising new
technique to construct artificial 2D electron lattices. Here we theoretically
propose a molecule lattice pattern to realize an artificial Lieb lattice on
metal surface, which shows a flat electronic band due to the lattice geometry.
We show that the localization of electrons in the flat band may be understood
from the viewpoint of electron interference, which may be probed by measuring
the local density of states with the scanning tunnelling microscopy. Our
proposal may be readily implemented in experiment and may offer an ideal solid
state platform to investigate the novel flat band physics of the Lieb lattice.


title: Singularities of plane rational curves via projections

abstract:
  We consider the parameterization ${\mathbf{f}}=(f_0,f_1,f_2)$ of a plane
rational curve $C$ of degree $n$, and we want to study the singularities of $C$
via such parameterization. We do this by using the projection from the rational
normal curve $C_n\subset \mathbb{P}^n$ to $C$ and its interplay with the secant
varieties to $C_n$. In particular, we define via ${\mathbf{f}}$ certain
0-dimensional schemes $X_k\subset \mathbb{P}^k$, $2\leq k\leq (n-1)$, which
encode all information on the singularities of multiplicity $\geq k$ of $C$
(e.g. using $X_2$ we can give a criterion to determine whether $C$ is a
cuspidal curve or has only ordinary singularities). We give a series of
algorithms which allow to get info about the singularities from such schemes.


title: High-Temperature Series Expansion for Spin-1/2 Heisenberg Models

abstract:
  We present a high-temperature series expansion code for spin-1/2 Heisenberg
models on arbitrary lattices. As an example we demonstrate how to use the
application for an anisotropic triangular lattice with two independent
couplings J1 and J2 and calculate the high-temperature series of the magnetic
susceptibility and the static structure factor up to 12th and 10th order,
respectively. We show how to extract effective coupling constants for the
triangular Heisenberg model from experimental data on Cs2CuBr4.


title: Mutual synchronization of nano-oscillators driven by pure spin current

abstract:
  We report the experimental observation of mutual synchronization of magnetic
nanooscillators driven by pure spin current generated by nonlocal spin
injection. We show that the oscillators efficiently synchronize due to the
direct spatial overlap of the dynamical modes excited by spin current, which is
facilitated by the large size of the auto-oscillation area inherent to these
devices. The synchronization occurs within an interval of the driving current
determined by the competition between the dynamic nonlinearity that facilitates
synchronization, and the short-wavelength magnetic fluctuations enhanced by the
spin current that suppress synchronization. The demonstrated synchronization
effects can be utilized to control the spatial and spectral characteristics of
the dynamical states induced by spin currents.


title:
Algebras sharing the same support $\tau$-tilting poset with tree quiver
  algebras

abstract:
  Happel and Unger reconstructed hereditary algebras from their posets of
tilting modules. Inspired by this result, we try removing the assumption to be
hereditary. However, it would be unfortunately fail in general: e.g. every
selfinjective algebra has the poset consisting of only one point. Therefore, we
should consider a generalization of the Happel-Unger's result for posets of
support $\tau$-tilting modules, which contains those of tilting modules. In
this paper, we spotlight finite dimensional algebras whose support
$\tau$-tilting posets coincide with those of tree quiver algebras and give a
full characterization of such algebras.


title: Light dilatons in warped space: Higgs boson and LHCb anomalies

abstract:
  We study the extension of the Standard Model (SM) with a light dilaton in a
five dimensional warped model. In particular, we analyze the coupling of the
dilaton with the SM matter fields, compare the model predictions with
Electroweak Precisions Tests and find the corresponding bounds on the mass of
the lightest Kaluza-Klein modes. We also investigate the possibility that the
Higgs-like resonance found at the LHC can be a dilaton. Finally, we show that
our set-up can also provide an explanation of the anomalies recently observed
in $B$-meson decays.


title: Polysemous codes

abstract:
  This paper considers the problem of approximate nearest neighbor search in
the compressed domain. We introduce polysemous codes, which offer both the
distance estimation quality of product quantization and the efficient
comparison of binary codes with Hamming distance. Their design is inspired by
algorithms introduced in the 90's to construct channel-optimized vector
quantizers. At search time, this dual interpretation accelerates the search.
Most of the indexed vectors are filtered out with Hamming distance, letting
only a fraction of the vectors to be ranked with an asymmetric distance
estimator.
  The method is complementary with a coarse partitioning of the feature space
such as the inverted multi-index. This is shown by our experiments performed on
several public benchmarks such as the BIGANN dataset comprising one billion
vectors, for which we report state-of-the-art results for query times below
0.3\,millisecond per core. Last but not least, our approach allows the
approximate computation of the k-NN graph associated with the Yahoo Flickr
Creative Commons 100M, described by CNN image descriptors, in less than 8 hours
on a single machine.


title:
Enhancing Channel Assignment Performance in Wireless Mesh Networks
  Through Interference Mitigation Functions

abstract:
  The notion of Total Interference Degree (TID) is traditionally used to
estimate the intensity of prevalent interference in a
Multi-RadioMulti-ChannelWirelessMesh Network (MRMC WMN). Numerous Channel
Assignment (CA) approaches, linkscheduling algorithms and routing schemes have
been proposed for WMNs which rely entirely on the concept of TID estimates.
They focus on minimizing TID to create a minimal interference scenario for the
network. In our prior works [1] and [2], we have questioned the efficacy of TID
estimate and then proposed two reliable interference estimation metrics viz.,
Channel Distribution Across Links Cost (CDALcost) and Cumulative X-Link-Set
Weight (CXLSwt). In this work, we assess the ability of these interference
estimation metrics to replace TID as the interferenceminimizing factor in a CA
scheme implemented on a grid MRMC WMN. We carry out a comprehensive evaluation
on ns-3 and then conclude from the results that the performance of the network
increases by 10-15% when the CA scheme uses CXLSwt as the underlying
Interference Mitigation Function (IMF) when compared with CA using TID as IMF.
We also confirm that CDALcost is not a better IMF than TID and CXLSwt.


title: A Note on Large H-Intersecting Families

abstract:
  A family $F$ of graphs on a fixed set of $n$ vertices is called
triangle-intersecting if for any $G_1,G_2 \in F$, the intersection $G_1 \cap
G_2$ contains a triangle. More generally, for a fixed graph $H$, a family $F$
is $H$-intersecting if the intersection of any two graphs in $F$ contains a
sub-graph isomorphic to $H$.
  In [D. Ellis, Y. Filmus, and E. Friedgut, Triangle-intersecting families of
graphs, J. Eur. Math. Soc. 14 (2012), pp. 841--885], Ellis, Filmus and Friedgut
proved a 36-year old conjecture of Simonovits and S\'{o}s stating that the
maximal size of a triangle-intersecting family is $(1/8)2^{n(n-1)/2}$.
Furthermore, they proved a $p$-biased generalization, stating that for any $p
\leq 1/2$, we have $\mu_{p}(F)\le p^{3}$, where $\mu_{p}(F)$ is the probability
that the random graph $G(n,p)$ belongs to $F$.
  In the same paper, Ellis et al. conjectured that the assertion of their
biased theorem holds also for $1/2 < p \le 3/4$, and more generally, that for
any non-$t$-colorable graph $H$ and any $H$-intersecting family $F$, we have
$\mu_{p}(F)\le p^{t(t+1)/2}$ for all $p \leq (2t-1)/(2t)$.
  In this note we construct, for any fixed $H$ and any $p>1/2$, an
$H$-intersecting family $F$ of graphs such that $\mu_{p}(F)\ge 1-e^{-n^{2}/C}$,
where $C$ depends only on $H$ and $p$, thus disproving both conjectures.


title: DAiSEE: Towards User Engagement Recognition in the Wild

abstract:
  We introduce DAiSEE, the first multi-label video classification dataset
comprising of 9068 video snippets captured from 112 users for recognizing the
user affective states of boredom, confusion, engagement, and frustration in the
wild. The dataset has four levels of labels namely - very low, low, high, and
very high for each of the affective states, which are crowd annotated and
correlated with a gold standard annotation created using a team of expert
psychologists. We have also established benchmark results on this dataset using
state-of-the-art video classification methods that are available today. We
believe that DAiSEE will provide the research community with challenges in
feature extraction, context-based inference, and development of suitable
machine learning methods for related tasks, thus providing a springboard for
further research. The dataset is available for download at
https://iith.ac.in/~daisee-dataset


title: Alphabet-Almost-Simple 2-Neighbour Transitive Codes

abstract:
  Let $X$ be a subgroup of the full automorphism group of the Hamming graph
$H(m,q)$, and $C$ a subset of the vertices of the Hamming graph. We say that
$C$ is an \emph{$(X,2)$-neighbour transitive code} if $X$ is transitive on $C$,
as well as $C_1$ and $C_2$, the sets of vertices which are distance $1$ and $2$
from the code. This paper begins the classification of $(X,2)$-neighbour
transitive codes where the action of $X$ on the entries of the Hamming graph
has a non-trivial kernel. There exists a subgroup of $X$ with a $2$-transitive
action on the alphabet; this action is thus almost-simple or affine. If this
$2$-transitive action is almost simple we say $C$ is
\emph{alphabet-almost-simple}. The main result in this paper states that the
only alphabet-almost-simple $(X,2)$-neighbour transitive code with minimum
distance $\delta\geq 3$ is the repetition code in $H(3,q)$, where $q\geq 5$.


title:
Fast driving between arbitrary states of a quantum particle by trap
  deformation

abstract:
  By performing a slow adiabatic change between two traps of a quantum
particle, it is possible to transform an eigenstate of the original trap into
the corresponding eigenstate of the final trap. If no level crossings are
involved, the process can be made faster than adiabatic by setting first the
interpolated evolution of the wave function from its initial to its final form
and inferring from this evolution the trap deformation. We find a simple and
compact formula which gives the trap shape at any time for any interpolation
scheme. It is applicable even in complicated scenarios where there is no
adiabatic process for the desired state-transformation, e.g., if the state
changes its topological properties. We illustrate its use for the expansion of
a harmonic trap, for the transformation of a harmonic trap into a linear trap
and into an arbitrary number of traps of a periodic structure. Finally, we
study the creation of a node exemplified by the passage from the ground state
to the first excited state of a harmonic oscillator.


title:
Determination of intrinsic ferroelectric polarization in lossy improper
  ferroelectric systems

abstract:
  We measured the intrinsic hysteretic polarization in lossy improper and
nanoferroelectric systems where the nonhysteretic polarization and leakage are
large and the relaxation takes place over a broader time scale. We used
different measurement protocols such as standard single triangular voltage
pulse, a pulse train of PUND (Positive Up Negative Down), and an even more
complicated pulse train of fourteen voltage pulses and compared the results
obtained. We show that a protocol which sends a train of fourteen pulses is
more appropriate for extracting relaxed (i.e., time scale independent) and
intrinsic remanent polarization for these samples. We also point out that it is
possible to select and design an appropriate measurement protocol depending on
the magnitude of polarization and leakage of the system.


title:
Flavor structure of $\Lambda$ baryons from lattice QCD: From strange to
  charm quarks

abstract:
  We study $\Lambda$ baryons of spin-parity $\frac{1}{2}^{\pm}$ with either a
strange or charm valence quark in full 2+1 flavor lattice QCD. Multiple $SU(3)$
singlet and octet operators are employed to generate the desired single baryon
states on the lattice. Via the variational method, the couplings of these
states to the different operators provide information about the flavor
structure of the $\Lambda$ baryons. We make use of the gauge configurations of
the PACS-CS Collaboration and chirally extrapolate the results for the masses
and $SU(3)$ flavor components to the physical point. We furthermore gradually
change the hopping parameter of the heaviest quark from strange to charm to
study how the properties of the $\Lambda$ baryons evolve as a function of the
heavy quark mass. It is found that the baryon energy levels increase almost
linearly with the quark mass. Meanwhile, the flavor structure of most of the
states remains stable, with the exception of the lowest $\frac{1}{2}^{-}$
state, which changes from a flavor singlet $\Lambda$ to a $\Lambda_c$ state
with singlet and octet components of comparable size. Finally, we discuss
whether our findings can be interpreted with the help of a simple quark model
and find that the negative-parity $\Lambda_c$ states can be naturally explained
as diquark excitations of the light $u$ and $d$ quarks. On the other hand, the
quark-model picture does not appear to be adequate for the negative-parity
$\Lambda$ states, suggesting the importance of other degrees of freedom to
describe them.


title: On recovering parabolic diffusions from their time-averages

abstract:
  The paper study a possibility to recover a parabolic diffusion from its
time-average when the values at the initial time are unknown. This problem can
be reformulated as a new boundary value problem where a Cauchy condition is
replaced by a prescribed time-average of the solution. It is shown that this
new problem is well-posed in certain classes of solutions. The paper
establishes existence, uniqueness, and a regularity of the solution for this
new problem and its modifications, including problems with singled out terminal
values.


title: Fillings of unit cotangent bundles of nonorientable surfaces

abstract:
  We prove that any minimal weak symplectic filling of the canonical contact
structure on the unit cotangent bundle of a nonorientable closed surface other
than the real projective plane is s-cobordant rel boundary to the disk
cotangent bundle of the surface. If the nonorientable surface is the Klein
bottle, then we show that the minimal weak symplectic filling is unique up to
homeomorphism.


title: Fast phase gates with trapped ions

abstract:
  We implement faster-than-adiabatic two-qubit phase gates using smooth
state-dependent forces. The forces are designed to leave no final motional
excitation, independently of the initial motional state in the harmonic,
small-oscillations limit. They are simple, explicit functions of time and the
desired logical phase of the gate, and are based on quadratic invariants of
motion and Lewis-Riesenfeld phases of the normal modes.


title: Query Optimization Techniques In Graph Databases

abstract:
  Graph databases (GDB) have recently been arisen to overcome the limits of
traditional databases for storing and managing data with graph-like structure.
Today, they represent a requirement for many applications that manage
graph-like data, like social networks. Most of the techniques, applied to
optimize queries in graph databases, have been used in traditional databases,
distribution systems... or they are inspired from graph theory. However, their
reuse in graph databases should take care of the main characteristics of graph
databases, such as dynamic structure, highly interconnected data, and ability
to efficiently access data relationships. In this paper, we survey the query
optimization techniques in graph databases. In particular, we focus on the
features they have introduced to improve querying graph-like data.


title:
Effects of long-range disorder and electronic interactions on the
  optical properties of graphene quantum dots

abstract:
  We theoretically investigate the effects of long-range disorder and
electron-electron interactions on the optical properties of hexagonal armchair
graphene quantum dots consisting of up to 10806 atoms. The numerical
calculations are performed using a combination of tight-binding, mean-field
Hubbard and configuration interaction methods. Imperfections in the graphene
quantum dots are modelled as a long-range random potential landscape, giving
rise to electron-hole puddles. We show that, when the electron-hole puddles are
present, tight-binding method gives a poor description of the low-energy
absorption spectra compared to meanfield and configuration interaction
calculation results. As the size of the graphene quantum dot is increased, the
universal optical conductivity limit can be observed in the absorption
spectrum. When disorder is present, calculated absorption spectrum approaches
the experimental results for isolated monolayer of graphene sheet.


title:
Double Vibronic process in the quantum spin ice candidate
  Tb$_2$Ti$_2$O$_7$ revealed by terahertz spectroscopy

abstract:
  The origin of quantum fluctuations responsible for the spin liquid state in
Tb$_2$Ti$_2$O$_7$ has remained a long standing problem. By synchrotron-based
terahertz measurements, we show evidence of strong coupling between the
magnetic and lattice degrees of freedom that provides a path to the quantum
melting process. As revealed by hybrid crystal electric field-phonon
excitations that appear at 0.67 THz below 200 K, and around 0.42 THz below 50
K, the double vibronic process is unique for Tb$^{3+}$ in the titanate family
due to adequate energy matching and strong quadrupolar moments. The results
suggest that lattice motion can indeed be the driving force behind spin flips
within the hybridized ground and first excited states, promoting quantum terms
in the effective Hamiltonian that describes Tb$_2$Ti$_2$O$_7$.


title:
Parity anomaly and spin transmutation in quantum spin Hall Josephson
  junctions

abstract:
  We study the Josephson effect in a quantum spin Hall system coupled to a
localized magnetic impurity. As a consequence of the fermion parity anomaly,
the spin of the combined system of impurity and spin-Hall edge alternates
between half-integer and integer values when the superconducting phase
difference across the junction advances by $2\pi$. This leads to characteristic
differences in the splittings of the spin multiplets by exchange coupling and
single-ion anisotropy at phase differences, for which time-reserval symmetry is
preserved. We discuss the resulting $8\pi$-periodic (or $\mathbb{Z}_4$)
fractional Josephson effect in the context of recent experiments.


title: Lion and Man Game in Compact Spaces

abstract:
  The pursuit-evasion game with two persons is considered. Both players are
moving in a metric space, have equal maximum speeds and complete information
about the location of each other. We study the sufficient conditions for a
capture (with a positive capture radius). We assume that Lion wins if he
manages the capture independently of the initial positions of the players and
the evader's strategy. We prove that the discrete-time simple pursuit strategy
is a Lion's winning strategy in a compact geodesic space satisfying the
betweenness property. In particular, it means that Lion wins in compact
CAT(0)-spaces, Ptolemy spaces, Buseman convex spaces or any geodesic space with
convex metric. We also do not need to use such properties as finite dimension,
smoothness, boundary regularity or contractibility of the loops.


title:
Representing derivatives of Chebyshev polynomials by Chebyshev
  polynomials

abstract:
  A recursion formula for derivatives of Chebyshev polynomials is replaced by
an explicit formula.


title:
Distributed Compressive Sensing: Performance Analysis with Diverse
  Signal Ensembles

abstract:
  Distributed compressive sensing is a framework considering jointly sparsity
within signal ensembles along with multiple measurement vectors (MMVs). The
current theoretical bound of performance for MMVs, however, is derived to be
the same with that for single MV (SMV) because no assumption about signal
ensembles is made.
  In this work, we propose a new concept of inducing the factor called
"Euclidean distances between signals" for the performance analysis of MMVs. The
novelty is that the size of signal ensembles will be taken into consideration
in our analysis to theoretically show that MMVs indeed exhibit better
performance than SMV. Although our concept can be broadly applied to CS
algorithms with MMVs, the case study conducted on a well-known greedy solver
called simultaneous orthogonal matching pursuit (SOMP) will be explored in this
paper. We show that the performance of SOMP, when incorporated with our concept
by modifying the steps of support detection and signal estimations, will be
improved remarkably, especially when the Euclidean distances between signals
are short. The performance of modified SOMP is verified to meet our theoretical
prediction.


title: The loss of interest for the euro in Romania

abstract:
  We generalize a money demand micro-founded model to explain Romanians' recent
loss of interest for the euro. We show that the reason behind this loss of
interest is a severe decline in the relative degree of the euro liquidity
against that of the Romanian leu.


title: Normes cyclotomiques na{\"i}ves et unit{\'e}s logarithmiques

abstract:
  We compute the Z-rank of the subgroup of elements of the multiplicative group
of a number field K that are norms from every finite level of the cyclotomic
Z{\ell}-extension of K. Thus we compare its {\ell}-adification with the group
of logarithmic units of K. By the way we point out an easy proof of the
Gross-Kuz'min conjecture for {\ell}-undecomposed extensions of abelian fields.


title: Entanglement-symmetry control in a quantum-dot Cooper-pair splitter

abstract:
  The control of nonlocal entanglement in solid state systems is a crucial
ingredient of quantum technologies. We investigate a Cooper-pair splitter based
on a double quantum dot realised in a semiconducting nanowire. In the presence
of interdot tunnelling the system provides a simple mechanism to develop
spatial entanglement even in absence of nonlocal coupling with the
superconducting lead. We discuss the possibility to control the symmetry
(singlet or triplet) of spatially separated, entangled electron pairs taking
advantage of the spin-orbit coupling of the nanowire. We also demonstrate that
the spin-orbit coupling does not impact over the entanglement purity of the
nonlocal state generated in the double quantum dot system.


title: Quantum Interference in Graphene Nanoconstrictions

abstract:
  We report quantum interference effects in the electrical conductance of
chemical vapor deposited graphene nanoconstrictions fabricated using feedback
controlled electroburning. The observed multimode Fabry-Perot interferences can
be attributed to reflections at potential steps inside the channel. Sharp
antiresonance features with a Fano line shape are observed. Theoretical
modeling reveals that these Fano resonances are due to localized states inside
the constriction, which couple to the delocalized states that also give rise to
the Fabry-Perot interference patterns. This study provides new insight into the
interplay between two fundamental forms of quantum interference in graphene
nanoconstrictions.


title: The millimeter IRAM-30m line survey toward IK Tau

abstract:
  We carried out a millimeter wavelength line survey between 79 and 356 GHz
with the IRAM-30m telescope to investigate the physical and chemical properties
of the molecular envelope of the oxygen-rich AGB star IK Tau. We analysed the
molecular lines detected using the population diagram technique to derive
rotational temperatures and column densities. Additionally, we conducted a
radiative transfer analysis of the SO$_2$ lines detected. For the first time in
this source we detected rotational lines in the ground vibrational state of
HCO$^+$, NS, NO, and H$_2$CO, as well as several isotopologues of molecules
previously identified. We also detected several rotational lines in
vibrationally excited states of SiS and SiO isotopologues, and rotational lines
of H$_2$O ($\nu_{\mathrm{2}}$=2). We have also increased the number of
rotational lines detected of molecules that were previously identified,
enabling a detailed study of the molecular abundances and excitation
temperatures. IK Tau displays a rich chemistry for an oxygen-rich circumstellar
envelope. We highlight the detection of NS and H$_2$CO with fractional
abundances of f(NS)$\sim$10$^{-8}$ and f(H$_2$CO)$\sim$[10$^{-7}$--10$^{-8}$].
Most of the molecules display rotational temperatures between 15 and 40 K. NaCl
and SiS isotopologues display rotational temperatures higher than the average
(~65 K). In the case of SO$_2$ a warm component with
$T_{\mathrm{rot}}$$\sim$290 K is also detected. This SO$_2$ warm component is
probably arising from the inner regions of the envelope (at $\sim$8$R_{*}$)
where SO$_2$ has a fractional abundance of f(SO$_2$)$\sim$10$^{-6}$. This
result should be considered for future investigation of the main formation
channels of this, and other, parent species in the inner winds of O-rich AGB
stars, which at present are not well reproduced by current chemistry models.


title: Schur partition theorems via perfect crystal

abstract:
  We propose a generalization of Schur regular partitions for each odd integer
$p\geq 3$. Applying Kashiwara crystal theory, we prove that the number of
partitions of $n$ with this condition is equinumerous to the number of strict
$p$-class regular partitions of $n$. At $p=3$, it is Schur's 1926 partition
theorem found as a mod 6 analog of the Rogers-Ramanujan partition theorem
(RRPT). The statement for $p=5$ was conjectured by Andrews in 1970s in a course
of his 3 parameter generalization of RRPT and proved in 1994 by
Andrews-Bessenrodt-Olsson with an aid of computer.


title:
Spin excitations in the quasi-two-dimensional charge-ordered insulator
  $\alpha$-(BEDT-TTF)$_2$I$_3$ probed via $^{13}$C NMR

abstract:
  The spin excitations from the nonmagnetic charge-ordered insulating state of
$\alpha$-(BEDT-TTF)$_2$I$_3$ at ambient pressure have been investigated by
probing the static and low-frequency dynamic spin susceptibilities via
site-selective nuclear magnetic resonance at $^{13}$C sites. The site-dependent
values of the shift and the spin-lattice relaxation rate $1/T_1$ below the
charge-ordering transition temperature ($T_{CO} \approx$ 135 K) demonstrate a
spin density imbalance in the unit cell, in accord with the charge-density
ratio reported earlier. The shift and $1/T_1$ show activated temperature
dependence with a static (shift) gap $\Delta_S \approx$ 47-52 meV and a dynamic
($1/T_1$) gap $\Delta_R \approx$ 40 meV. The sizes of the gaps are well
described in terms of a localized spin model, where spin one-half
antiferromagnetic dimer chains are weakly coupled with each other.


title: Long Brownian bridges in hyperbolic spaces converge to Brownian trees

abstract:
  We show that the range of a long Brownian bridge in the hyperbolic space
converges after suitable renormalisation to the Brownian continuum random tree.
This result is a relatively elementary consequence of $\bullet$ A theorem by
Bougerol and Jeulin, stating that the rescaled radial process converges to the
normalized Brownian excursion, $\bullet$ A property of invariance under
re-rooting, $\bullet$ The hyperbolicity of the ambient space in the sense of
Gromov. A similar result is obtained for the rescaled infinite Brownian loop in
hyperbolic space.


title:
Rectifiability of varifolds with locally bounded first variation with
  respect to anisotropic surface energies

abstract:
  We extend Allard's celebrated rectifiability theorem to the setting of
varifolds with locally bounded first variation with respect to an anisotropic
integrand. In particular, we identify a sufficient and necessary condition on
the integrand to obtain the rectifiability of every \(d\)-dimensional varifold
with locally bounded first variation and positive \(d\)-dimensional density. In
codimension one, this condition is shown to be equivalent to the strict
convexity of the integrand with respect to the tangent plane.


title: On the structure of groups endowed with a compatible C-relation

abstract:
  We use quasi-orders to describe the structure of C-groups. We do this by
associating a quasi-order to each compatible C-relation of a group, and then
give the structure of such quasi-ordered groups. We also reformulate in terms
of quasi-orders some results concerning C-minimal groups given by Macpherson
and Steinhorn.


title:
Integer-valued autoregressive models with survival probability driven by
  a stochastic recurrence equation

abstract:
  A new class of integer-valued autoregressive models with dynamic survival
probability is proposed. The peculiarity of this class of models lies on the
specification of the survival probability through a stochastic recurrence
equation. The estimation of the model can be performed by maximum likelihood
and the consistency of the estimator is proved in a misspecified model setting.
The flexibility of the proposed specification is illustrated in a simulation
study. An application to a time series of crime reports is presented. The
results show how the dynamic survival probability can enhance both in-sample
and out-of-sample performances of integer-valued autoregressive models.


title:
A fractional elliptic problem in $\mathbb{R}^n$ with critical growth and
  convex nonlinearities

abstract:
  In this paper we prove the existence of a positive solution of the nonlinear
and nonlocal elliptic equation in $\mathbb{R}^n$ \[ (-\Delta)^s u =\varepsilon
h u^q+u^{2_s^*-1} \] in the convex case $1\leq q<2_s^*-1$, where $
2_s^*={2n}/({n-2s}) $ is the critical fractional Sobolev exponent,
$(-\Delta)^s$ is the fractional Laplace operator, $\varepsilon$ is a small
parameter and $h$ is a given bounded, integrable function. The problem has a
variational structure and we prove the existence of a solution by using the
classical Mountain-Pass Theorem. We work here with the harmonic extension of
the fractional Laplacian, which allows us to deal with a weighted (but possibly
degenerate) local operator, rather than with a nonlocal energy. In order to
overcome the loss of compactness induced by the critical power we use a
Concentration-Compactness principle. Moreover, a finer analysis of the geometry
of the energy functional is needed in this convex case.


title: X-ray bounds on the r-mode amplitude in millisecond pulsars

abstract:
  r-mode astroseismology provides a unique way to study the internal
composition of compact stars. Due to their precise timing, recycled millisecond
radio pulsars present a particularly promising class of sources. Although their
thermal properties are still poorly constrained, X-ray data is very useful for
astroseismology since r-modes could strongly heat a star. Using known and new
upper bounds on the temperatures and luminosities of several non-accreting
millisecond radio pulsars we derive bounds on the r-mode amplitude as low as
$\alpha\lesssim10^{-8}$ and discuss the impact on scenarios for their internal
composition.


title: A note on a certain Baum--Connes map for inverse semigroups

abstract:
  Let $G$ denote a countable inverse semigroup. We construct a kind of a
Baum--Connes map $K(\tilde A \rtimes G) \rightarrow K(A \rtimes G)$ by a
categorial approach via localization of triangulated categories, developed by
R. Meyer and R. Nest for groups $G$. We allow the coefficient algebras $A$ to
be in a special class of algebras called fibered $G$-algebras. This note
continues and fixes our preprint "Attempts to define a Baum--Connes map via
localization of categories for inverse semigroups".


title:
Symmetric invariants related to representations of exceptional simple
  groups

abstract:
  We classify the finite-dimensional rational representations $V$ of the
exceptional algebraic groups $G$ with $\mathfrak g={\sf Lie}(G)$ such that the
symmetric invariants of the semi-direct product $\mathfrak g\ltimes V$, where
$V$ is an Abelian ideal, form a polynomial ring.


title: Polyp Detection and Segmentation from Video Capsule Endoscopy: A Review

abstract:
  Video capsule endoscopy (VCE) is used widely nowadays for visualizing the
gastrointestinal (GI) tract. Capsule endoscopy exams are prescribed usually as
an additional monitoring mechanism and can help in identifying polyps,
bleeding, etc. To analyze the large scale video data produced by VCE exams
automatic image processing, computer vision, and learning algorithms are
required. Recently, automatic polyp detection algorithms have been proposed
with various degrees of success. Though polyp detection in colonoscopy and
other traditional endoscopy procedure based images is becoming a mature field,
due to its unique imaging characteristics detecting polyps automatically in VCE
is a hard problem. We review different polyp detection approaches for VCE
imagery and provide systematic analysis with challenges faced by standard image
processing and computer vision methods.


title: Many Facets of Strangeness Nuclear Physics with Stored Antiprotons

abstract:
  Stored antiprotons beams in the GeV range represent a unparalleled factory
for hyperon-antihyperon pairs. Their outstanding large production probability
in antiproton collisions will open the floodgates for a series of new studies
of strange hadronic systems with unprecedented precision. The behavior of
hyperons and -- for the first time -- of antihyperons in nuclear systems can be
studied under well controlled conditions. The exclusive production of
$\Lambda\bar{\Lambda}$ and $\Sigma^-\bar{\Lambda}$ pairs in antiproton-nucleus
interactions probe the neutron and proton distribution in the nuclear periphery
and will help to sample the neutron skin. For the first time, high resolution
$\gamma$-spectroscopy of doubly strange nuclei will be performed, thus
complementing measurements of ground state decays of double hypernuclei with
mesons beams at J-PARC or possible decays of particle unstable hypernuclei in
heavy ion reactions. High resolution spectroscopy of multistrange $\Xi$-atoms
are feasible and even the production of $\Omega^-$-atoms will be within reach.
The latter might open the door to the $|s|$=3 world in strangeness nuclear
physics, by the study of the hadronic $\Omega^-$-nucleus interaction and the
very first measurement of a spectroscopic quadrupole moment of a baryon which
will be a benchmark test for our understanding of hadron structure.


title:
SNOPS: Short Non-Orthogonal Pilot Sequences for Downlink Channel State
  Estimation in FDD Massive MIMO

abstract:
  Channel state information (CSI) acquisition is a significant bottleneck in
the design of Massive MIMO wireless systems, due to the length of the training
sequences required to distinguish the antennas (in the downlink) and the users
(for the uplink where a given spectral resource can be shared by a large number
of users). In this article, we focus on the downlink CSI estimation case.
Considering the presence of spatial correlation at the base transceiver station
(BTS) side, and assuming that the per-user channel statistics are known, we
seek to exploit this correlation to minimize the length of the pilot sequences.
We introduce a scheme relying on non-orthogonal pilot sequences and feedback
from the user terminal (UT), which enables the BTS to estimate all downlink
channels. Thanks to the relaxed orthogonality assumption on the pilots, the
length of the obtained pilot sequences can be strictly lower than the number of
antennas at the BTS, while the CSI estimation error is kept arbitrarily small.
We introduce two algorithms to dynamically design the required pilot sequences,
analyze and validate the performance of the proposed CSI estimation method
through numerical simulations using a realistic scenario based on the one-ring
channel model.


title:
A new correlation with lower kilohertz quasi-periodic oscillation
  frequency in the ensemble of low-mass X-ray binaries

abstract:
  We study the dependence of kHz quasi-periodic oscillation (QPO) frequency on
accretion-related parameters in the ensemble of neutron star low-mass X-ray
binaries. Based on the mass accretion rate, $\dot{M}$, and the magnetic field
strength, $B$, on the surface of the neutron star, we find a correlation
between the lower kHz QPO frequency and $\dot{M}/B^{2}$. The correlation holds
in the current ensemble of Z and atoll sources and therefore can explain the
lack of correlation between the kHz QPO frequency and X-ray luminosity in the
same ensemble. The average run of lower kHz QPO frequencies throughout the
correlation can be described by a power-law fit to source data. The simple
power-law, however, cannot describe the frequency distribution in an individual
source. The model function fit to frequency data, on the other hand, can
account for the observed distribution of lower kHz QPO frequencies in the case
of individual sources as well as the ensemble of sources. The model function
depends on the basic length scales such as the magnetospheric radius and the
radial width of the boundary region, both of which are expected to vary with
$\dot{M}$ to determine the QPO frequencies. In addition to modifying the length
scales and hence the QPO frequencies, the variation in $\dot{M}$, being
sufficiently large, may also lead to distinct accretion regimes, which would be
characterized by Z and atoll phases.


title: From Nonstandard Analysis to various flavours of Computability Theory

abstract:
  As suggested by the title, it has recently become clear that theorems of
Nonstandard Analysis (NSA) give rise to theorems in computability theory (no
longer involving NSA). Now, the aforementioned discipline divides into
classical and higher-order computability theory, where the former (resp. the
latter) sub-discipline deals with objects of type zero and one (resp. of all
types). The aforementioned results regarding NSA deal exclusively with the
higher-order case; we show in this paper that theorems of NSA also give rise to
theorems in classical computability theory by considering so-called textbook
proofs.


title: Experimental results on charge fluctuations in heavy-ion collisions

abstract:
  We present a subset of experimental results on charge fluctuation from the
heavy-ion collisions to search for phase transition and location of critical
point in the QCD phase diagram. Measurements from the heavy-ion experiments at
the SPS and RHIC energies observe that total charge fluctuations increase from
central to peripheral collisions. The net-charge fluctuations in terms of
dynamical fluctuation measure $\nu_{(+-,dyn)}$ are studied as a function of
collision energy (\sqsn) and centrality of the collisions. The product of
$\nu_{(+-,dyn)}$ and $\langle N_{ch} \rangle$ shows a monotonic decrease with
collision energies, which indicates that at LHC energy the fluctuations have
their origin in the QGP phase. The fluctuations in terms of higher moments of
net-proton, net-electric charge and net-kaon have been measured for various
\sqsn. Deviations are observed in both $S\sigma$ and $\kappa\sigma^2$ for
net-proton multiplicity distributions from the Skellam and hadron resonance gas
model for \sqsn $<$ 39 GeV. Higher moment results of the net-electric charge
and net-kaon do not observe any significant non-monotonic behavior as a
function of collision energy. We also discuss the extraction of the freeze-out
parameters using particle ratios and experimentally measured higher moments of
net-charge fluctuations. The extracted freeze-out parameters from
experimentally measured moments and lattice calculations, are found to be in
agreement with the results obtained from the fit of particle ratios to the
thermal model calculations.


title: A Model for Partial Kantian Cooperation

abstract:
  In several game situations, the behavior of the players may depend not only
on individual interests, but also on what each player considers as the correct
thing to do. This work presents a game theoretic model, aiming to describe game
situations in which the players' behavior is affected by ethical
considerations. Particularly, we assume that they partially follow, Kant's
`Categorical Imperative'. The model is stated for games with a continuum of
players. The basic assumption made is that the participants perceive that they
belong to virtual (imagined) groups, in which they optimize their actions as if
they were bound to follow the same strategy. A partially cooperative
equilibrium, called $r$-Kant-Nash equilibrium is then introduced. We then study
the relationship of the $r$-Kant-Nash equilibrium with the Nash, (Bentham-)
Harsanyi, Rawls difference and Roemer solutions. For the case where the set of
possible player types is finite, we prove sufficient conditions for the
existence and uniqueness of the $r$-Kant-Nash equilibrium and the equilibrium
is characterized in terms of a variational inequality. For the case of
continuous types, necessary conditions characterizing the partial Kantian
equilibria are derived using a reduction to a set of optimal control problems.
Finally, some numerical examples are given.


title:
Topological Triplon Modes and Bound States in a Shastry-Sutherland
  Magnet

abstract:
  The twin discoveries of the quantum Hall effect, in the 1980's, and of
topological band insulators, in the 2000's, were landmarks in physics that
enriched our view of the electronic properties of solids. In a nutshell, these
discoveries have taught us that quantum mechanical wavefunctions in crystalline
solids may carry nontrivial topological invariants which have ramifications for
the observable physics. One of the side effects of the recent topological
insulator revolution has been that such physics is much more widespread than
was appreciated ten years ago. For example, while topological insulators were
originally studied in the context of electron wavefunctions, recent work has
led to proposals of topological insulators in bosonic systems: in photonic
crystals, in the vibrational modes of crystals, and in the excitations of
ordered magnets. Here we confirm the recent proposal that, in a weak magnetic
field, the dimerized quantum magnet SrCu$_{2}$(BO$_{3}$)$_2$ is a bosonic
topological insulator with nonzero Chern number in the triplon bands and
topologically protected chiral edge excitations.


title: On-shell diagrams and the geometry of planar N < 4 SYM theories

abstract:
  We continue the discussion of the decorated on-shell diagrammatics for planar
N < 4 Supersymmetric Yang-Mills theories started in arXiv:1510.03642. In
particular, we focus on its relation with the structure of varieties on the
Grassmannian. The decoration of the on-shell diagrams, which physically keeps
tracks of the helicity of the coherent states propagating along their edges,
defines new on-shell functions on the Grassmannian and can introduce novel
higher-order singularities, which graphically are reflected into the presence
of helicity loops in the diagrams. These new structures turn out to have
similar features as in the non-planar case: the related higher-codimension
varieties are identified by either the vanishing of one (or more) Plucker
coordinates involving at least two non-adjacent columns, or new relations among
Plucker coordinates. A distinctive feature is that the functions living on
these higher-codimenson varieties can be thought of distributionally as having
support on derivative delta-functions. After a general discussion, we explore
in some detail the structures of the on-shell functions on Gr(2,4) and Gr(3,6)
on which the residue theorem allows to obtain a plethora of identities among
them.


title: Dynamical Complexity Of Short and Noisy Time Series

abstract:
  Shannon Entropy has been extensively used for characterizing complexity of
time series arising from chaotic dynamical systems and stochastic processes
such as Markov chains. However, for short and noisy time series, Shannon
entropy performs poorly. Complexity measures which are based on lossless
compression algorithms are a good substitute in such scenarios. We evaluate the
performance of two such Compression-Complexity Measures namely Lempel-Ziv
complexity ($LZ$) and Effort-To-Compress ($ETC$) on short time series from
chaotic dynamical systems in the presence of noise. Both $LZ$ and $ETC$
outperform Shannon entropy ($H$) in accurately characterizing the dynamical
complexity of such systems. For very short binary sequences (which arise in
neuroscience applications), $ETC$ has higher number of distinct complexity
values than $LZ$ and $H$, thus enabling a finer resolution. For two-state
ergodic Markov chains, we empirically show that $ETC$ converges to a steady
state value faster than $LZ$. Compression-Complexity Measures are promising for
applications which involve short and noisy time series.


title:
Large X-ray Flares on Stars Detected with MAXI/GSC: A Universal
  Correlation between the Duration of a Flare and its X-ray Luminosity

abstract:
  23 giant flares from 13 active stars (eight RS CVn systems, one Algol system,
three dMe stars and one YSO) were detected during the first two years of our
all-sky X-ray monitoring with the gas propotional counters (GSC) of the Monitor
of All-sky X-ray Image (MAXI). The observed parameters of all of these MAXI/GSC
flares are found to be at the upper ends for stellar flares with the luminosity
of 10^(31-34) ergs s-1 in the 2-20 keV band, the emission measure of 10^(54-57)
cm-3, the e-folding time of 1 hour to 1.5 days, and the total radiative energy
released during the flare of 10^(34-39) ergs. Notably, the peak X-ray
luminosity of 5(3-9)*10^33 ergs s-1 in the 2-20 keV band was detected in one of
the flares on II Peg, which is one of the, or potentially the, largest ever
observed in stellar flares. X-ray flares were detected from GT Mus, V841 Cen,
SZ Psc, and TWA-7 for the first time in this survey. Whereas most of our
detected sources are multiple-star systems, two of them are single stars (YZ
CMi and TWA-7). Among the stellar sources within 100 pc distance, the MAXI/GSC
sources have larger rotation velocities than the other sources. This suggests
that the rapid rotation velocity may play a key role in generating large
flares. Combining the X-ray flare data of nearby stars and the sun, taken from
literature and our own data, we discovered a universal correlation of
tau~L_X^0.2 for the flare duration tau and the intrinsic X-ray luminosity L_X
in the 0.1-100 keV band, which holds for 5 and 12 orders of magnitude in tau
and L_X, respectively. The MAXI/GSC sample is located at the highest ends on
the correlation.


title:
A modular architecture for transparent computation in Recurrent Neural
  Networks

abstract:
  Computation is classically studied in terms of automata, formal languages and
algorithms; yet, the relation between neural dynamics and symbolic
representations and operations is still unclear in traditional eliminative
connectionism. Therefore, we suggest a unique perspective on this central
issue, to which we would like to refer as to transparent connectionism, by
proposing accounts of how symbolic computation can be implemented in neural
substrates. In this study we first introduce a new model of dynamics on a
symbolic space, the versatile shift, showing that it supports the real-time
simulation of a range of automata. We then show that the Goedelization of
versatile shifts defines nonlinear dynamical automata, dynamical systems
evolving on a vectorial space. Finally, we present a mapping between nonlinear
dynamical automata and recurrent artificial neural networks. The mapping
defines an architecture characterized by its granular modularity, where data,
symbolic operations and their control are not only distinguishable in
activation space, but also spatially localizable in the network itself, while
maintaining a distributed encoding of symbolic representations. The resulting
networks simulate automata in real-time and are programmed directly, in absence
of network training. To discuss the unique characteristics of the architecture
and their consequences, we present two examples: i) the design of a Central
Pattern Generator from a finite-state locomotive controller, and ii) the
creation of a network simulating a system of interactive automata that supports
the parsing of garden-path sentences as investigated in psycholinguistics
experiments.


title:
Preliminaries on CAT (0) Spaces and Fixed Points of a Class of Iterative
  Schemes

abstract:
  This paper gives some relating results for various concepts of convexity in
metric spaces such as midpoint convexity, convex structure, uniform convexity
and near-uniform convexity, Busemann curvature and its relation to convexity.
Some properties of uniform convexity and near uniform convexity of geodesic
metric spaces are related to the mapping built with the concourse of two
primary mappings and the associated generated sequences by some iterative
schemes.


title:
Scaling of spectra of Cantor-type measures and some number theoretic
  considerations

abstract:
  We investigate some relations between number theory and spectral measures
related to the harmonic analysis of a Cantor set. Specifically, we explore ways
to determine when an odd natural number $m$ generates a complete or incomplete
Fourier basis for a Cantor-type measure with scale $g$.


title: Non-equilibrium dynamics for a Widom-Rowlinson type model with mutations

abstract:
  A dynamical version of the Widom-Rowlinsom model in the continuum is
considered. The dynamics is modelled by a spatial two-component birth-and-death
Glauber process where particles, in addition, are allowed to change their type
with density dependent rates. An evolution of states is constructed as the
unique weak solution to the associated Fokker-Planck equation. Such solution is
obtained by means of its correlation functions which belong to a certain Ruelle
space. Existence of a unique invariant measure and ergodicity with exponential
rate is established. The mesoscopic limit is considered, it is related with the
verification of the chaos preservation property.


title: Witt equivalence of function fields of conics

abstract:
  Two fields are Witt equivalent if, roughly speaking, they have the same
quadratic form theory. Formally, that is to say that their Witt rings of
symmetric bilinear forms are isomorphic. This equivalence is well understood
only in a few rather specific classes of fields. Two such classes, namely
function fields over global fields and function fields of curves over local
fields, were investigated by the authors in their earlier works. In the present
work, which can be viewed as a sequel to the earlier papers, we discuss the
previously obtained results in the specific case of function fields of conic
sections, and apply them to provide a few theorems of a somewhat quantitive
flavour shedding some light on the question of numbers of Witt non-equivalent
classes of such fields.


title: Free wreath product quantum groups and standard invariants of subfactors

abstract:
  By a construction of Vaughan Jones, the bipartite graph $\Gamma(A)$
associated with the natural inclusion of $\mathbb C$ inside a
finite-dimensional $C^*$-algebra $A$ gives rise to a planar algebra $\mathcal
P^{\Gamma(A)}$. We prove that every subfactor planar subalgebra of $\mathcal
P^{\Gamma(A)}$ is the fixed point planar algebra of a uniquely determined
action of a compact quantum group $\mathbb G$ on $A$. We use this result to
introduce a conceptual framework for the free wreath product operation on
compact quantum groups in the language of planar algebras/standard invariants
of subfactors. Our approach unifies both previous definitions of the free
wreath product due to Bichon and Fima-Pittau and extends them to a considerably
larger class of compact quantum groups. In addition, we observe that the
central Haagerup property for discrete quantum groups is stable under the free
wreath product operation (on their duals) and we deduce a positive answer to a
conjecture of Banica and Bichon on the distribution of the character of a free
wreath product.


title:
A three-dimensional approach to Visual Speech Recognition using Discrete
  Cosine Transforms

abstract:
  Visual speech recognition aims to identify the sequence of phonemes from
continuous speech. Unlike the traditional approach of using 2D image feature
extraction methods to derive features of each video frame separately, this
paper proposes a new approach using a 3D (spatio-temporal) Discrete Cosine
Transform to extract features of each feasible sub-sequence of an input video
which are subsequently classified individually using Support Vector Machines
and combined to find the most likely phoneme sequence using a tailor-made
Hidden Markov Model. The algorithm is trained and tested on the VidTimit
database to recognise sequences of phonemes as well as visemes (visual speech
units). Furthermore, the system is extended with the training on phoneme or
viseme pairs (biphones) to counteract the human speech ambiguity of
co-articulation. The test set accuracy for the recognition of phoneme sequences
is 20%, and the accuracy of viseme sequences is 39%. Both results improve the
best values reported in other papers by approximately 2%. The contribution of
the result is three-fold: Firstly, this paper is the first to show that 3D
feature extraction methods can be applied to continuous sequence recognition
tasks despite the unknown start positions and durations of each phoneme.
Secondly, the result confirms that 3D feature extraction methods improve the
accuracy compared to 2D features extraction methods. Thirdly, the paper is the
first to specifically compare an otherwise identical method with and without
using biphones, verifying that the usage of biphones has a positive impact on
the result.


title: Sentiment Classification of Food Reviews

abstract:
  Sentiment analysis of reviews is a popular task in natural language
processing. In this work, the goal is to predict the score of food reviews on a
scale of 1 to 5 with two recurrent neural networks that are carefully tuned. As
for baseline, we train a simple RNN for classification. Then we extend the
baseline to GRU. In addition, we present two different methods to deal with
highly skewed data, which is a common problem for reviews. Models are evaluated
using accuracies.


title: Computing DM-decomposition of a partitioned matrix with rank-1 blocks

abstract:
  In this paper, we develop a polynomial time algorithm to compute a
Dulmage-Mendelsohn-type decomposition of a matrix partitioned into submatrices
of rank at most $1$.


title: Path planning and Obstacle avoidance approaches for Mobile robot

abstract:
  A new path planning method for Mobile Robots (MR) has been developed and
implemented. On the one hand, based on the shortest path from the start point
to the goal point, this path planner can choose the best moving directions of
the MR, which helps to reach the target point as soon as possible. On the other
hand, with an intelligent obstacle avoidance, our method can find the target
point with the near-shortest path length while avoiding some infinite loop
traps of several obstacles in unknown environments. The combination of two
approaches helps the MR to reach the target point with a very reliable
algorithm. Moreover, by continuous updates of the on-board sensors information,
this approach can generate the MRs trajectory both in static and dynamic
environments. A large number of simulations in some similar studies
environments demonstrate the power of the proposed path planning algorithm.


title:
Barlenses and X-shape features compared: different manifestations of
  Boxy/Peanut bulges

abstract:
  Morphological characteristics of the vertically thick inner bar components
are studied. At high galaxy inclinations they manifest as Boxy/Peanut/X-shape
features, and near to face-on view as barlenses. Using the Spitzer Survey of
Stellar Structure in Galaxies (S4G) and the Near-IR S0 galaxy Survey (NIRS0S),
we compared the properties of 88 X-shape features, 85 barlenses, and the
photometric bulges of 41 non-barred galaxies. Sizes and minor-to-major axis
ratios (b/a) of these structures are compared, and interpreted by means of
synthetic images using N-body simulation models. Barlenses and their parent
galaxies are also divided into different sub-groups. The synthetic images are
analyzed in a similar manner as the observations. This is the first time that
the observed properties of barlenses and X-shape features are compared, over a
large range of galaxy inclinations. Our analysis are consistent with the idea
that barlenses and X-shape features are physically the same phenomenon.
However, which of the two features is observed depends, not only on galaxy
inclination, but also on its central flux concentration. The observed nearly
round face-on barlens morphology is expected when at least a few percents of
the disk mass is in a central component, within a region much smaller than the
size of the barlens itself. We also discuss that the large range of stellar
population ages obtained for the photometric bulges in the literature, are
consistent with our interpretation.


title:
Hard rectangles near curved hard walls: tuning the sign of the Tolman
  length

abstract:
  Combining analytic calculations, computer simulations, and classical density
functional theory we determine the interfacial tension of orientable
two-dimensional hard rectangles near a curved hard wall. Both a circular cavity
holding the particles and a hard circular obstacle surrounded by particles are
considered. We focus on moderate bulk densities (corresponding to area
fractions up to 50 percent) where the bulk phase is isotropic and vary the
aspect ratio of the rectangles and the curvature of the wall. The Tolman
length, which gives the leading curvature correction of the interfacial
tension, is found to change sign at a finite density, which can be tuned via
the aspect ratio of the rectangles.


title:
Weighted estimates for powers and Smoothing estimates of Schr\"odinger
  operators with inverse-square potentials

abstract:
  Let $\mathcal{L}_a$ be a Schr\"odinger operator with inverse square potential
$a|x|^{-2}$ on $\mathbb{R}^d, d\geq 3$. The main aim of this paper is to prove
weighted estimates for fractional powers of $\mathcal{L}_a$. The proof is based
on weighted Hardy inequalities and weighted inequalities for square functions
associated to $\mathcal{L}_a$. As an application, we obtain smoothing estimates
regarding the propagator $e^{it\mathcal{L}_a}$.


title:
On the covering radius of lattice zonotopes and its relation to
  view-obstructions and the lonely runner conjecture

abstract:
  The goal of this paper is twofold; first, show the equivalence between
certain problems in geometry, such as view-obstruction and billiard ball
motions, with the estimation of covering radii of lattice zonotopes. Second, we
will estimate upper bounds of said radii by virtue of the Flatness Theorem.
These problems are similar in nature with the famous lonely runner conjecture.


title:
Approximation of smooth functions using Bernstein polynomials in
  multiple variables

abstract:
  In this survey, we use (more or less) elementary means to establish the
well-known result that for any given smooth multivariate function, the
respective multivariate Bernstein polynomials converge to that function in all
derivatives on each compact set. We then go on to strengthen that result to
obtain that any smooth function on $\mathbb R^d$ may be approximated locally
uniformly in all derivatives by \emph{one} sequence of polynomials. We will use
neither the axiom of choice nor the power set axiom. We will use the method of
proof by contradiction.


title:
Role of acoustic phonons in frequency dependent thermal conductivity of
  graphene

abstract:
  We study the effect of the electron-phonon interaction on the finite
frequency dependent electronic thermal conductivity of two dimensional
graphene. We calculate it for various acoustic phonons present in graphene and
characterized by different dispersion relations using the memory function
approach. It is found that the thermal conductivity $\kappa(T)$ in the zero
frequency limit follows different power law for the longitudinal/transverse and
the flexural acoustic phonons. For the longitudinal/transverse phonons,
$\kappa(T) \sim T^{-1}$ at the low temperature and saturates at the high
temperature. These signatures are qualitatively agree with the results
predicted by the Boltzmann equation. Similarly, for the flexural phonons, we
find that $\kappa(T)$ shows $T^{1/2}$ law at the low temperature and then
saturates at the high temperature. In the finite frequency regime, we observe
that the real part of the thermal conductivity, $\text{Re}[\kappa(\omega,T)]$
follows $\omega^{-2}$ behavior at the low frequency and becomes frequency
independent at the high frequency.


title:
Revisiting the prediction of solar activity based on the relationship
  between the solar maximum amplitude and max-max cycle length

abstract:
  It is very important to forecast the future solar activity due to its effect
on our planet and near space. Here, we employ the new version of the sunspot
number index (version 2) to analyse the relationship between the solar maximum
amplitude and max-max cycle length proposed by Du (2006). We show that the
correlation between the parameters used by Du (2006) for the prediction of the
sunspot number (amplitude of the cycle, Rm, and max-max cycle length for two
solar cycles before, Pmax-2) disappears when we use solar cycles prior to solar
cycle 9. We conclude that the correlation between these parameters depends on
the time interval selected. Thus, the proposal of Du (2006) should definitively
not be considered for prediction purposes.


title: Gravitational Couplings on D-brane Revisited

abstract:
  Gravitational couplings in bulk space-time include those terms which are
fixed by scattering amplitude of strings and ambiguous terms that are coming
from the field redefinitions. These field redefinitions can be fixed in the
bulk by ghost-free condition. In this paper we have revised the effective
gravitational couplings on D-branes by including the field redefinitions. We
find the gravitational effective action up to $\alpha'^2$-order.


title:
Evolution of clusters in energetic heavy ion bombarded amorphous
  graphite

abstract:
  Carbon clusters have been generated by a novel technique of energetic heavy
ion bombardment of amorphous graphite. The evolution of clusters and their
subsequent fragmentation under continuing ion bombardment is revealed by
detecting various clusters in the energy spectra of the direct recoils emitted
as a result of collision between ions and the surface constituents.


title: On the computational content of the Loeb measure

abstract:
  The Loeb measure is one of the cornerstones of Nonstandard Analysis. The
traditional development of the Loeb measure makes use of saturation and
external sets. Inspired by [13], we give meaning to special cases of the Loeb
measure in the weak fragment $\textsf{P}$ of Nelson's internal set theory from
[1]. Perhaps surprisingly, our definition of the Loeb measure has computational
content in the sense of the `term extraction' framework from [1].


title:
Equation of motion of canonical tensor model and Hamilton-Jacobi
  equation of general relativity

abstract:
  The canonical tensor model (CTM) is a rank-three tensor model formulated as a
totally constrained system in the canonical formalism. The constraint algebra
of CTM has a similar structure as that of the ADM formalism of general
relativity, and is studied as a discretized model for quantum gravity. In this
paper, we analyze the classical equation of motion (EOM) of CTM in a formal
continuum limit through a derivative expansion of the tensor up to the forth
order, and show that it is the same as the EOM of a coupled system of gravity
and a scalar field derived from the Hamilton-Jacobi equation with an
appropriate choice of an action. The action contains a scalar field potential
of an exponential form, and the system classically respects a dilatational
symmetry. We find that the system has a critical dimension, given by six, over
which it becomes unstable due to the wrong sign of the scalar kinetic term. In
six dimensions, de Sitter spacetime becomes a solution to the EOM, signaling
the emergence of a conformal symmetry, while the time evolution of the scale
factor is power-law in dimensions below six.


title: Modelling of C2 addition route to the formation of C60

abstract:
  To understand the phenomenon of fullerene growth during its synthesis, an
attempt is made to model a minimum energy growth route using a semi-empirical
quantum mechanics code. C2 addition leading to C60 was modelled and three main
routes, i.e. cyclic ring growth, pentagon and fullerene road, were studied. The
growth starts with linear chains and, at n = 10, ring structures begins to
dominate. The rings continue to grow and, at some point n > 30, they transform
into close-cage fullerenes and the growth is shown to progress by the fullerene
road until C60 is formed. The computer simulations predict a transition from a
C38 ring to fullerene. Other growth mechanisms could also occur in the
energetic environment commonly encountered in fullerene synthesis, but our
purpose was to identify a minimal energy route which is the most probable
structure. Our results also indicate that, at n = 20, the corannulene structure
is energetically more stable than the corresponding fullerene and graphene
sheet, however a ring structure has lower energy among all the structures up to
n 6 40. Additionally, we have also proved that the fullerene road is
energetically more favored than the pentagon road. The overall growth leading
to cage closure for n = 60 may not occur by a single route but by a combination
of more than one route.


title: Wikipedia mining of hidden links between political leaders

abstract:
  We describe a new method of reduced Google matrix which allows to establish
direct and hidden links between a subset of nodes of a large directed network.
This approach uses parallels with quantum scattering theory, developed for
processes in nuclear and mesoscopic physics and quantum chaos. The method is
applied to the Wikipedia networks in different language editions analyzing
several groups of political leaders of USA, UK, Germany, France, Russia and
G20. We demonstrate that this approach allows to recover reliably direct and
hidden links among political leaders. We argue that the reduced Google matrix
method can form the mathematical basis for studies in social and political
sciences analyzing Leader-Members eXchange (LMX).


title:
Spectra and elliptic flow of thermal photons from full overlap U+U
  collisions at RHIC

abstract:
  We calculate $p_T$ spectra and elliptic flow for tip-tip and body-body
configurations of full overlap uranium-uranium (U+U) collisions using a
hydrodynamic model with smooth initial density distribution and compare the
results with those obtained from Au+Au collisions at RHIC. Production of
thermal photons is seen to be significantly larger for tip-tip collisions
compared to body-body collisions of uranium nuclei in the region $p_T >$ 1 GeV.
The thermal photon spectrum from body-body collisions is found to be close to
the spectrum from most central Au+Au collisions at RHIC. The elliptic flow
parameter calculated for body-body collisions is found to be large and
comparable to the $v_2(p_T)$ for mid-central collisions of Au nuclei. On the
other hand, as expected, the $v_2(p_T)$ is close to zero for tip-tip
collisions. The qualitative nature of the photon spectra and elliptic flow for
the two different orientations of uranium nuclei is found to be independent of
the initial parameters of the model calculation. We show that the photon
results from fully overlapping U+U collisions are complementary to the results
from Au+Au collisions at RHIC.


title:
Equality of two non-logarithmic ramification filtrations of abelianized
  Galois group in positive characteristic

abstract:
  We prove the equality of two non-logarithmic ramification filtrations defined
by Matsuda and Abbes-Saito for the abelianized absolute Galois group of a
complete discrete valuation field in positive characteristic. We also compute
the refined Swan conductor and the characteristic form of a character of the
fundamental group of a smooth separated scheme over a perfect field of positive
characteristic by using sheaves of Witt vectors.


title: Public Wi-Fi Monetization via Advertising

abstract:
  The proliferation of public Wi-Fi hotspots has brought new business
potentials for Wi-Fi networks, which carry a significant amount of global
mobile data traffic today. In this paper, we propose a novel Wi-Fi monetization
model for venue owners (VOs) deploying public Wi-Fi hotspots, where the VOs can
generate revenue by providing two different Wi-Fi access schemes for mobile
users (MUs): (i) the premium access, in which MUs directly pay VOs for their
Wi-Fi usage, and (ii) the advertising sponsored access, in which MUs watch
advertisements in exchange of the free usage of Wi-Fi. VOs sell their ad spaces
to advertisers (ADs) via an ad platform, and share the ADs' payments with the
ad platform. We formulate the economic interactions among the ad platform, VOs,
MUs, and ADs as a three-stage Stackelberg game. In Stage I, the ad platform
announces its advertising revenue sharing policy. In Stage II, VOs determine
the Wi-Fi prices (for MUs) and advertising prices (for ADs). In Stage III, MUs
make access choices and ADs purchase advertising spaces. We analyze the
sub-game perfect equilibrium (SPE) of the proposed game systematically, and our
analysis shows the following useful observations. First, the ad platform's
advertising revenue sharing policy in Stage I will affect only the VOs' Wi-Fi
prices but not the VOs' advertising prices in Stage II. Second, both the VOs'
Wi-Fi prices and advertising prices are non-decreasing in the advertising
concentration level and non-increasing in the MU visiting frequency. Numerical
results further show that the VOs are capable of generating large revenues
through mainly providing one type of Wi-Fi access (the premium access or
advertising sponsored access), depending on their advertising concentration
levels and MU visiting frequencies.


title:
A kilo-pixel imaging system for future space based far-infrared
  observatories using microwave kinetic inductance detectors

abstract:
  Future astrophysics and cosmic microwave background space missions operating
in the far-infrared to millimetre part of the spectrum will require very large
arrays of ultra-sensitive detectors in combination with high multiplexing
factors and efficient low-noise and low-power readout systems. We have
developed a demonstrator system suitable for such applications. The system
combines a 961 pixel imaging array based upon Microwave Kinetic Inductance
Detectors (MKIDs) with a readout system capable of reading out all pixels
simultaneously with only one readout cable pair and a single cryogenic
amplifier. We evaluate, in a representative environment, the system performance
in terms of sensitivity, dynamic range, optical efficiency, cosmic ray
rejection, pixel-pixel crosstalk and overall yield at at an observation centre
frequency of 850 GHz and 20% fractional bandwidth. The overall system has an
excellent sensitivity, with an average detector sensitivity NEPdet=3x10^-19
W/rt(Hz) measured using a thermal calibration source. At a loading power per
pixel of 50fW we demonstrate white, photon noise limited detector noise down to
300 mHz. The dynamic range would allow the detection of 1 Jy bright sources
within the field of view without tuning the readout of the detectors. The
expected dead time due to cosmic ray interactions, when operated in an L2 or a
similar far-Earth orbit, is found to be <4%. Additionally, the achieved pixel
yield is 83% and the crosstalk between the pixels is <-30dB. This demonstrates
that MKID technology can provide multiplexing ratios on the order of a 1000
with state-of-the-art single pixel performance, and that the technology is now
mature enough to be considered for future space based observatories and
experiments.


title:
Scale-free unique continuation principle, eigenvalue lifting and Wegner
  estimates for random Schr\"odinger operators

abstract:
  We prove a scale-free, quantitative unique continuation principle for
functions in the range of the spectral projector $\chi_{(-\infty,E]}(H_L)$ of a
Schr\"odinger operator $H_L$ on a cube of side $L\in \mathbb{N}$, with bounded
potential. Such estimates are also called, depending on the context,
uncertainty principles, observability estimates, or spectral inequalities. We
apply it to (i) prove a Wegner estimate for random Schr\"odinger operators with
non-linear parameter-dependence and to (ii) exhibit the dependence of the
control cost on geometric model parameters for the heat equation in a
multi-scale domain.


title: Breaking of Goldstone modes in two component Bose-Einstein condensate

abstract:
  We study the decay rate $\Gamma(k)$ of density excitations of two-component
Bose-Einstein condensates at zero temperature. Those excitations, where the two
components oscillate in phase, include the Goldstone mode resulting from
condensation. While within Bogoliubov approximation the density sector and the
spin (out-of-phase) sector are independent, they couple at the three-phonon
level. For a Bose-Bose mixture we find that the Belyaev decay is slightly
modified due to the coupling with the gapless spin mode. At the phase
separation point the decay rate changes instead from the standard $k^5$ to a
$k^{5/2}$ behaviour due to the parabolic nature of the spin mode. In presence
of coherent coupling between the two components the spin sector is gapped and,
away from the ferromagnetic-like phase transition point, the decay of density
mode is not affected. On the other hand at the transition point, when the spin
fluctuations become critical, the Goldstone mode is not well defined anymore
since $\Gamma(k)\propto k$. As a consequence, we show that the friction induced
by a moving impurity is enahnced -- a feature which could be experimentally
tested. Our results apply to every non-linear 2-component quantum hydrodynamic
Hamiltonian which is time-reversal invariant, and possesses an $U(1)\times
{\mathbf Z}_2$ symmetry.


title:
Proton heating by pick-up ion driven cyclotron waves in the outer
  heliosphere: Hybrid expanding box simulations

abstract:
  Using one-dimensional hybrid expanding box model we investigate properties of
the solar wind in the outer heliosphere. We assume a proton-electron plasma
with a strictly transverse ambient magnetic field and, beside the expansion, we
take into account influence of a continuous injection of cold pick-up protons
through the charge-exchange process between the solar wind protons and hydrogen
of interstellar origin. The injected cold pick-up protons form a ring
distribution function that rapidly becomes unstable and generate Alfv\'en
cyclotron waves. The Alfv\'en cyclotron waves scatter pick-up protons to a
spherical shell distribution function that thickens over that time owing to the
expansion-driven cooling. The Alf\'ven cyclotron waves heat solar wind protons
in the perpendicular direction (with respect to the ambient magnetic field)
through the cyclotron resonance. At later times, the Alfv\'en cyclotron waves
become parametrically unstable and the generated ion acoustic waves heat
protons in the parallel direction through the Landau resonance. The resulting
heating of the solar wind protons is efficient on the expansion time scale.


title: Robust Location of Optical Fiber Modes via the Argument Principle Method

abstract:
  We implement a robust, globally convergent root search method for
transcendental equations guaranteed to locate all complex roots within a
specified search domain, based on Cauchy's residue theorem. Although several
implementations of the argument principle already exist, ours has several
advantages: it allows singularities within the search domain and branch points
are not fatal to the method. Furthermore, our implementation is simple and is
written in MATLAB, fulfilling the need for an easily integrated implementation
which can be readily modified to accommodate the many variations of the
argument principle method, each of which is suited to a different application.
We apply the method to the step index fiber dispersion relation, which has
become topical due to the recent proliferation of high index contrast fibers.
We also find modes with permittivity as the eigenvalue, catering to recent
numerical methods that expand the radiation of sources by eigenmodes.


title:
Infrared optical properties of $\alpha$ quartz by molecular dynamics
  simulations

abstract:
  This paper is concerned with theoretical estimates of the refractive--index
curves for quartz, obtained by the Kubo formul\ae\ in the classical
approximation, through MD simulations for the motions of the ions. Two
objectives are considered. The first one is to understand the role of
nonlinearities in situations where they are very large, as at the
$\alpha$--$\beta$ structural phase transition. We show that on the one hand
they don't play an essential role in connection with the form of the spectra in
the infrared. On the other hand they play an essential role in introducing a
chaoticity which involves a definite normal mode. This might explain why that
mode is Raman active in the $\alpha$ phase, but not in the $\beta$ phase. The
second objective concerns whether it is possible in a microscopic model to
obtain normal mode frequencies, or peak frequencies in the optical spectra,
that are in good agreement with the experimental data for quartz.
Notwithstanding a lot of effort, we were unable to find results agreeing better
than about 6%, as apparently also occurs in the whole available literature. We
interpret this fact as indicating that some essential qualitative feature is
lacking in all models which consider, as the present one, only short--range
repulsive potentials and unretarded long--range electric forces.


title: Object Tracking via Dynamic Feature Selection Processes

abstract:
  DFST proposes an optimized visual tracking algorithm based on the real-time
selection of locally and temporally discriminative features. A feature
selection mechanism is embedded in the Adaptive colour Names (CN) tracking
system that adaptively selects the top-ranked discriminative features for
tracking. DFST provides a significant gain in accuracy and precision allowing
the use of a dynamic set of features that results in an increased system
flexibility. DFST is based on the unsupervised method "Infinite Feature
Selection" (Inf-FS), which ranks features according with their "redundancy"
without using class labels. By using a fast online algorithm for learning
dictionaries the size of the box is adapted during the processing. At each
update, we use multiple examples around the target (at different positions and
scales). DFST also improved the CN by adding micro-shift at the predicted
position and bounding box adaptation.


title:
Entanglement manipulation by a magnetic pulse in Gd3N@C80 endohedral
  metallofullerenes on a Cu(001) surface

abstract:
  In this paper we present result of theoretical calculation of entanglement
within a spin structure of Gd3N@C80 under the in uence of rectangular impulses.
Research is conducted using general spin Hamiltonian within SSNQ (spin system
of N-qubits). Calculation of entanglement with variable impulse is performed
using the time-dependent Landau-Lifshitz-Gilbert equation with spin-spin
correlation function. We show that long rectangular impulse (t=850ps) can be
used for maintaining of entanglement value. This allows us to offer a new
algorithm which can be used to reduce the challenge of decoherence to logical
scheme optimization.


title:
Transition to turbulence and streamwise inhomogeneity of vortex tangle
  in thermal counterflow

abstract:
  We report preliminary results of the complementary experimental and numerical
studies on spatiotemporal tangle development and streamwise vortex line density
(VLD) distribution in counterflowing $^4$He. The experiment is set up in a long
square channel with VLD and local temperature measured in three streamwise
locations. In the steady state we observe nearly streamwise-homogeneous VLD.
Experimental second sound data as well as numerical data (vortex filament
method in a long planar channel starting with seeding vortices localized in
multiple locations) show that the initial build up pattern of VLD displays
complex features depending on the position in the channel, but the some tangle
properties appear uniform along its length.


title: Auction-Based Coopetition between LTE Unlicensed and Wi-Fi

abstract:
  Motivated by the recent efforts in extending LTE to the unlicensed spectrum,
we propose a novel spectrum sharing framework for the coopetition (i.e.,
cooperation and competition) between LTE and Wi-Fi in the unlicensed band.
Basically, the LTE network can choose to work in one of the two modes: in the
competition mode, it randomly accesses an unlicensed channel, and interferes
with the Wi-Fi access point using the same channel; in the cooperation mode, it
delivers traffic for the Wi-Fi users in exchange for the exclusive access of
the corresponding channel. Because the LTE network works in an
interference-free manner in the cooperation mode, it can achieve a much larger
data rate than that in the competition mode, which allows it to effectively
serve both its own users and the Wi-Fi users. We design a second-price reverse
auction mechanism, which enables the LTE provider and the Wi-Fi access point
owners (APOs) to effectively negotiate the operation mode. Specifically, the
LTE provider is the auctioneer (buyer), and the APOs are the bidders (sellers)
who compete to sell their channel access opportunities to the LTE provider. In
Stage I of the auction, the LTE provider announces a reserve rate. In Stage II
of the auction, the APOs submit their bids. We show that the auction involves
allocative externalities, i.e., the cooperation between the LTE provider and
one APO benefits other APOs who are not directly involved in this cooperation.
As a result, a particular APO's willingness to cooperate is affected by its
belief about other APOs' willingness to cooperate. This makes our analysis much
more challenging than that of the conventional second-price auction, where
bidding truthfully is a weakly dominant strategy. We show that the APOs have a
unique form of the equilibrium bidding strategies in Stage II, based on which
we analyze the LTE provider's optimal reserve rate in Stage I.


title:
Using Gaussian Processes for Rumour Stance Classification in Social
  Media

abstract:
  Social media tend to be rife with rumours while new reports are released
piecemeal during breaking news. Interestingly, one can mine multiple reactions
expressed by social media users in those situations, exploring their stance
towards rumours, ultimately enabling the flagging of highly disputed rumours as
being potentially false. In this work, we set out to develop an automated,
supervised classifier that uses multi-task learning to classify the stance
expressed in each individual tweet in a rumourous conversation as either
supporting, denying or questioning the rumour. Using a classifier based on
Gaussian Processes, and exploring its effectiveness on two datasets with very
different characteristics and varying distributions of stances, we show that
our approach consistently outperforms competitive baseline classifiers. Our
classifier is especially effective in estimating the distribution of different
types of stance associated with a given rumour, which we set forth as a desired
characteristic for a rumour-tracking system that will warn both ordinary users
of Twitter and professional news practitioners when a rumour is being rebutted.


title: The square lattice Ising model on the rectangle I: Finite systems

abstract:
  The partition function of the square lattice Ising model on the rectangle
with open boundary conditions in both directions is calculated exactly for
arbitrary system size $L\times M$ and temperature. We start with the dimer
method of Kasteleyn, McCoy & Wu, construct a highly symmetric block transfer
matrix and derive a factorization of the involved determinant, effectively
decomposing the free energy of the system into two parts,
$F(L,M)=F_\mathrm{strip}(L,M)+F_\mathrm{strip}^\mathrm{res}(L,M)$, where the
residual part $F_\mathrm{strip}^\mathrm{res}(L,M)$ contains the nontrivial
finite-$L$ contributions for fixed $M$. It is given by the determinant of a
$\frac{M}{2}\times \frac{M}{2}$ matrix and can be mapped onto an effective spin
model with $M$ Ising spins and long-range interactions. While
$F_\mathrm{strip}^\mathrm{res}(L,M)$ becomes exponentially small for large
$L/M$ or off-critical temperatures, it leads to important finite-size effects
such as the critical Casimir force near criticality. The relations to the
Casimir potential and the Casimir force are discussed.

categories: math-ph cond-mat.stat-mech hep-lat math.MP


title:
Spherical collapse model and cluster number counts in power law $f(T)$
  gravity

abstract:
  We study the spherical collapse model (SCM) in the framework of spatially
flat power law $f(T) \propto (-T)^{b}$ gravity model. We find that the linear
and non-linear growth of spherical overdensities of this particular $f(T)$
model are affected by the power-law parameter $b$. Finally, we compute the
predicted number counts of virialized haloes in order to distinguish the
current $f(T)$ model from the expectations of the concordance $\Lambda$
cosmology. Specifically, the present analysis suggests that the $f(T)$ gravity
model with positive (negative) $b$ predicts more (less) virialized objects with
respect to those of $\Lambda$CDM.


title:
Symmetries of line bundles and Noether theorem for time-dependent
  nonholonomic systems

abstract:
  We consider Noether symmetries of the equations defined by the sections of
characteristic line bundles of nondegenerate 1-forms and of the associated
perturbed systems. It appears that this framework can be used for
time-dependent systems with constraints and nonconservative forces, allowing a
quite simple and transparent formulation of the momentum equation and the
Noether theorem in their general forms.


title: The dangers of non-empirical confirmation

abstract:
  In the book "String Theory and the Scientific Method", Richard Dawid
describes a few of the many non-empirical arguments that motivate theoretical
physicists' confidence in a theory, taking string theory as case study. I argue
that excessive reliance on non-empirical evidence compromises the reliability
of science, and that precisely the case of string theory well illustrates this
danger.


title: Challenges and Opportunities in Edge Computing

abstract:
  Many cloud-based applications employ a data centre as a central server to
process data that is generated by edge devices, such as smartphones, tablets
and wearables. This model places ever increasing demands on communication and
computational infrastructure with inevitable adverse effect on
Quality-of-Service and Experience. The concept of Edge Computing is predicated
on moving some of this computational load towards the edge of the network to
harness computational capabilities that are currently untapped in edge nodes,
such as base stations, routers and switches. This position paper considers the
challenges and opportunities that arise out of this new direction in the
computing landscape.


title:
Optimum mixed-state discrimination for noisy entanglement-enhanced
  sensing

abstract:
  Quantum metrology utilizes nonclassical resources, such as entanglement or
squeezed light, to realize sensors whose performance exceeds that afforded by
classical-state systems. Environmental loss and noise, however, easily destroy
nonclassical resources, and thus nullify the performance advantages of most
quantum-enhanced sensors. Quantum illumination (QI) is different. It is a
robust entanglement-enhanced sensing scheme whose 6 dB performance advantage
over a coherent-state sensor of the same average transmitted photon number
survives the initial entanglement's eradication by loss and noise.
Unfortunately, an implementation of the optimum quantum receiver that would
reap QI's full performance advantage has remained elusive, owing to its having
to deal with a huge number of very noisy optical modes. We show how
sum-frequency generation (SFG) can be fruitfully applied to optimum multi-mode
Gaussian-mixed-state discrimination. Applied to QI, our analysis and numerical
evaluations demonstrate that our SFG receiver saturates QI's quantum Chernoff
bound. Moreover, augmenting our SFG receiver with a feed-forward (FF) mechanism
pushes its performance to the Helstrom bound in the limit of low signal
brightness. The FF-SFG receiver thus opens the door to optimum quantum-enhanced
imaging, radar detection, state and channel tomography, and communication in
practical Gaussian-state situations.


title: Automorphisms of K-groups I

abstract:
  This is the first in a sequence of papers that will develop the theory of
automorphisms of nonsolvable finite groups. The sequence will culminate in a
new proof of McBride's Nonsolvable Signalizer Functor Theorem, which is one of
the fundamental results required for the proof of the Classification of the
Finite Simple Groups.


title: Tagged spectator DIS on a polarized spin-1 target

abstract:
  We discuss the process of deep-inelastic electron scattering (DIS) on the
polarized deuteron with detection of a nucleon in the nuclear fragmentation
region ("spectator tagging"). We cover (a) the general structure of the
semi-inclusive DIS cross section on a spin-1 target; (b) the tagged structure
functions in the impulse approximation, where deuteron structure is described
by the $NN$ light-front wave function; (c) the extraction of free neutron
structure through on-shell extrapolation in the recoil proton momentum. As an
application we consider the extraction of the neutron spin structure function
$g_{1n}$ through polarized electron scattering on the longitudinally polarized
deuteron with proton tagging and on-shell extrapolation. Such measurements
would be possible at an Electron-Ion Collider (EIC) with polarized deuteron
beams and forward proton detectors.


title:
Optimal-order isogeometric collocation at Galerkin superconvergent
  points

abstract:
  In this paper we investigate numerically the order of convergence of an
isogeometric collocation method that builds upon the least-squares collocation
method presented in [1] and the variational collocation method presented in
[2]. The focus is on smoothest B-splines/NURBS approximations, i.e, having
global $C^{p-1}$ continuity for polynomial degree $p$. Within the framework of
[2], we select as collocation points a subset of those considered in [1], which
are related to the Galerkin superconvergence theory. With our choice, that
features local symmetry of the collocation stencil, we improve the convergence
behaviour with respect to [2], achieving optimal $L^2$-convergence for odd
degree B-splines/NURBS approximations. The same optimal order of convergence is
seen in [1], where, however a least-squares formulation is adopted. Further
careful study is needed, since the robustness of the method and its
mathematical foundation are still unclear.


title: Fragile Systems: A hidden variable theory for quantum mechanics

abstract:
  The formalism of Quantum Mechanics is derived from the application of
Bayesian probability theory to "fragile" systems, i.e. systems that are
perturbed by the act of measurement. Complex Hilbert spaces, non-commuting
operators and the trace rule for expectations all arise naturally from the use
of linear algebra to solve integral equations involving classical probabilities
over hidden variables. We comment on the case of non-local hidden variables,
where violations of Bell's theorem can be produced, as well as the non-fragile
limit of the theory, where all measurements are commutative and the theory
becomes analogous to classical statistical mechanics.


title:
Emerging magnetism and anomalous Hall effect in iridate-manganite
  heterostructures

abstract:
  Strong Coulomb repulsion and spin-orbit coupling are known to give rise to
exotic physical phenomena in transition metal oxides. Initial attempts to
investigate systems where both of these fundamental interactions are comparably
strong, such as 3d and 5d complex oxide superlattices, have revealed properties
that only slightly differ from the bulk ones of the constituent materials.
Here, we observe that the interfacial coupling between the 3d antiferromagnetic
insulator SrMnO3 and the 5d paramagnetic metal SrIrO3 is enormously strong,
yielding an anomalous Hall response as the result of charge transfer driven
interfacial ferromagnetism. These findings show that low dimensional spin-orbit
entangled 3d-5d interfaces provide an avenue to uncover technologically
relevant physical phenomena unattainable in bulk materials.


title: Real hyperbolic hyperplane complements in the complex hyperbolic plane

abstract:
  This paper studies Riemannian manifolds of the form $M \setminus S$, where
$M^4$ is a complete four dimensional Riemannian manifold with finite volume
whose metric is modeled on the complex hyperbolic plane $\mathbb{C}
\mathbb{H}^2$, and $S$ is a compact totally geodesic codimension two
submanifold whose induced Riemannian metric is modeled on the real hyperbolic
plane $\mathbb{H}^2$. In this paper we write the metric on $\mathbb{C}
\mathbb{H}^2$ in polar coordinates about $S$, compute formulas for the
components of the curvature tensor in terms of arbitrary warping functions
(Theorem 7.1), and prove that there exist warping functions that yield a
complete finite volume Riemannian metric on $M \setminus S$ whose sectional
curvature is bounded above by a negative constant (Theorem 1.1(1)). The cases
of $M \setminus S$ modeled on $\mathbb{H}^n \setminus \mathbb{H}^{n-2}$ and
$\mathbb{C} \mathbb{H}^n \setminus \mathbb{C} \mathbb{H}^{n-1}$ were studied by
Belegradek in [Bel12] and [Bel11], respectively. One may consider this work as
"part 3" to this sequence of papers.


title:
Tailoring correlations of the local density of states in disordered
  photonic materials

abstract:
  We present experimental evidence for the different mechanisms driving the
fluctuations of the local density of states (LDOS) in disordered photonic
systems. We establish a clear link between the microscopic structure of the
material and the frequency correlation function of LDOS accessed by a
near-field hyperspectral imaging technique. We show, in particular, that short-
and long-range frequency correlations of LDOS are controlled by different
physical processes (multiple or single scattering processes, respectively) that
can be---to some extent---manipulated independently. We also demonstrate that
the single scattering contribution to LDOS fluctuations is sensitive to
subwavelength features of the material and, in particular, to the correlation
length of its dielectric function. Our work paves a way towards a complete
control of statistical properties of disordered photonic systems, allowing for
designing materials with predefined correlations of LDOS.