title:
The Latin American Giant Observatory: Contributions to the 34th
  International Cosmic Ray Conference (ICRC 2015)

abstract:
  The Latin American Giant Observatory (LAGO) is an extended cosmic ray
observatory composed by a network of water-Cherenkov detectors spanning over
different sites located at significantly different altitudes (from sea level up
to more than $5000$\,m a.s.l.) and latitudes across Latin America, covering a
huge range of geomagnetic rigidity cut-offs and atmospheric absorption/reaction
levels. This detection network is designed to measure the temporal evolution of
the radiation flux at ground level with extreme detail. The LAGO project is
mainly oriented to perform basic research in three branches: high energy
phenomena, space weather and atmospheric radiation at ground level. LAGO is
built and operated by the LAGO Collaboration, a non-centralized collaborative
union of more than 30 institutions from ten countries.
  These are the contributions of the LAGO Collaboration to the 34th
International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The
Netherlands


title:
Maximal Ratio Combining Diversity Analysis of Underwater Acoustic
  Communications Subject to ${\kappa}-{\mu}$ Shadowed Fading Channels

abstract:
  In this paper, a novel unified analytical expression for average bit error
rates (ABER) and average channel capacity (ACC) is presented for the
${\kappa}-{\mu}$ shadowed fading model. This new shadowed fading model has
shown to be suitable for underwater wireless channel modeling for the
measurements conducted by the Naval Research Laboratory, and is not so well
covered in the public literature. Deploying the Maximal Ratio Combining (MRC)
receiver, a new simple analytical expression for the probability density
function (PDF) of the receiver output signal to noise ratio is presented. Based
on this new PDF, the novel unified ABER and ACC expression derived. To further
generalize the error rate analysis, the additive white generalized Gaussian
noise model is assumed that models the different noise environments. The new
unified expression is accurate, simple and generic, and is suitable for MRC
analysis in this generalized shadowed fading and noise environment. Numerical
techniques and published results from the technical literature corroborate the
generality and accuracy of our analysis under the different test scenarios.


title: Cutoff regulators in chiral nuclear effective field theory

abstract:
  Three-dimensional cutoff regulators are frequently employed in multi-nucleon
calculations, but they violate chiral symmetry and Lorentz invariance. A cutoff
regularization scheme is proposed to compensate systematically at subleading
orders for these symmetry violations caused by regulator artifacts. This is
especially helpful when a soft momentum cutoff has to be used for technical
reasons. It is also shown that dimensional regularization can still be used for
some Feynman (sub)diagrams while cutoff regulators are used for the rest.


title:
Numerical study on the effect of design parameters and spacers on RPC
  signal and timing properties

abstract:
  Numerical calculations have been performed to understand the reason for the
observed non-uniform response of a Resistive Plate Chamber (RPC) in a few
critical regions such as near edge spacers and corners of the device. In this
context, the signal from a RPC due to the passage of muons through different
regions has been computed. Also, a simulation of RPC timing properties is
presented along with the effect of the applied field, gas mixture and
geometrical components.


title: Monte-Carlo study of the MRPC prototype for the upgrade of BESIII

abstract:
  A GEANT4-based simulation is developed for the endcap time of flight (ETOF)
upgrade based on multi-gap resistive plate chambers (MRPC) for the BESIII
experiment. The MRPC prototype and the simulation method are described. Using a
full Monte-Carlo simulation, the influence of high voltage and threshold on
time resolution and detection efficiency are investigated. The preliminary
results from simulation are presented and are compared with the experimental
data taken with the prototype MRPC modules.


title: The Complexity of Simulation and Matrix Multiplication

abstract:
  Computing the simulation preorder of a given Kripke structure (i.e., a
directed graph with $n$ labeled vertices) has crucial applications in model
checking of temporal logic. It amounts to solving a specific two-players
reachability game, called simulation game. We offer the first conditional lower
bounds for this problem, and we relate its complexity (for computation,
verification, and certification) to some variants of $n\times n$ matrix
multiplication.
  We show that any $O(n^{\alpha})$-time algorithm for simulation games, even
restricting to acyclic games/structures, can be used to compute $n\times n$
boolean matrix multiplication (BMM) in $O(n^{\alpha})$ time. This is the first
evidence that improving the existing $O(n^{3})$-time solutions may be
difficult, without resorting to fast matrix multiplication. In the acyclic
case, we match this lower bound presenting the first subcubic algorithm, based
on fast BMM, and running in $n^{\omega+o(1)}$ time (where $\omega<2.376$ is the
exponent of matrix multiplication).
  For both acyclic and cyclic structures, we point out the existence of natural
and canonical $O(n^{2})$-size certificates, that can be verified in truly
subcubic time. In the acyclic case, $O(n^{2})$ time is sufficient, employing
standard matrix product verification. In the cyclic case, a $\max$-semi-boolean
matrix multiplication (MSBMM) is used, i.e., a matrix multiplication on the
semi-ring $(\max,\times)$ where one matrix contains only $0$'s and $1$'s. This
MSBMM is computable (hence verifiable) in truly subcubic
$n^{(3+\omega)/2+o(1)}$ time by reduction to $(\max,\min)$-multiplication.
  Finally, we show a reduction from MSBMM to cyclic simulation games which
implies a separation between the cyclic and the acyclic cases, unless MSBMM can
be verified in $n^{\omega+o(1)}$ time.


title: The Strauss conjecture on asymptotically flat space-times

abstract:
  By assuming a certain localized energy estimate, we prove the existence
portion of the Strauss conjecture on asymptotically flat manifolds, possibly
exterior to a compact domain, when the spatial dimension is 3 or 4. In
particular, this result applies to the 3 and 4-dimensional Schwarzschild and
Kerr (with small angular momentum) black hole backgrounds, long range
asymptotically Euclidean spaces, and small time-dependent asymptotically flat
perturbations of Minkowski space-time. We also permit lower order perturbations
of the wave operator. The key estimates are a class of weighted Strichartz
estimates, which are used near infinity where the metrics can be viewed as
small perturbations of the Minkowski metric, and the assumed localized energy
estimate, which is used in the remaining compact set.


title:
Two-parameter scaling theory of the longitudinal magnetoconductivity in
  a Weyl metal phase: Chiral anomaly, weak disorder, and finite temperature

abstract:
  It is at the heart of modern condensed matter physics to investigate the role
of a topological structure in anomalous transport phenomena. In particular,
chiral anomaly turns out to be the underlying mechanism for the negative
longitudinal magnetoresistivity in a Weyl metal phase. Existence of a
dissipationless current channel causes enhancement of electric currents along
the direction of a pair of Weyl points or applied magnetic fields ($B$).
However, temperature ($T$) dependence of the negative longitudinal
magnetoresistivity has not been understood yet in the presence of disorder
scattering since it is not clear at all how to introduce effects of disorder
scattering into the "topological-in-origin" transport coefficient at finite
temperatures. The calculation based on the Kubo formula of the current-current
correlation function is simply not known for this anomalous transport
coefficient. Combining the renormalization group analysis with the Boltzmann
transport theory to encode the chiral anomaly, we reveal how disorder
scattering renormalizes the distance between a pair of Weyl points and such a
renormalization effect modifies the topological-in-origin transport coefficient
at finite temperatures. As a result, we find breakdown of $B/T$ scaling, given
by $B/T^{1 + \eta}$ with $0 < \eta < 1$. This breakdown may be regarded to be a
fingerprint of the interplay between disorder scattering and topological
structure in a Weyl metal phase.


title:
Topological spin Meissner effect in exciton-polariton spinor condensate:
  constant amplitude solutions, half-vortices and symmetry breaking

abstract:
  We generalize the spin Meissner effect for exciton-polariton condensate
confined in annular geometries to the case of non-trivial topology of the
condensate wavefunction. In contrast to the conventional spin Meissner state,
topological spin Meissner states can in principle be observed at arbitrary high
magnetic field not limited by the critical magnetic field value for the
condensate in a simply-connected geometry. One special example of the
topological Meissner states are half-vortices. We show that in the absence of
magnetic field half-vortices in a ring exist in a form of superposition of
elementary half-vortex states which resolves recent experimental results where
such puzzling superposition was observed. Furthermore, we show that if a pure
half-vortex state is to be observed, a non-zero magnetic field of a specific
magnitude needs to be applied. Studying exciton-polariton in a ring in presence
of TE-TM splitting, we observe spin Meissner states which break rotational
symmetry of the system by developing inhomogeneous density distributions. We
classify various states arising in presence of non-zero TE-TM splitting based
on what states they can be continued from by increasing the TE-TM splitting
parameter from zero. With further increasing TE-TM splitting, states with
broken symmetry may transform into stable half-dark solitons and therefore may
serve as a useful tool to generate various non-trivial states of a spinor
condensate.


title: Belief Merging by Source Reliability Assessment

abstract:
  Merging beliefs requires the plausibility of the sources of the information
to be merged. They are typically assumed equally reliable in lack of hints
indicating otherwise; yet, a recent line of research spun from the idea of
deriving this information from the revision process itself. In particular, the
history of previous revisions and previous merging examples provide information
for performing subsequent mergings.
  Yet, no examples or previous revisions may be available. In spite of the
apparent lack of information, something can still be inferred by a
try-and-check approach: a relative reliability ordering is assumed, the merging
process is performed based on it, and the result is compared with the original
information. The outcome of this check may be incoherent with the initial
assumption, like when a completely reliable source is rejected some of the
information it provided. In such cases, the reliability ordering assumed in the
first place can be excluded from consideration. The first theorem of this
article proves that such a scenario is indeed possible. Other results are
obtained under various definition of reliability and merging.


title:
Survey Observations of a Possible Glycine Precursor, Methanimine
  (CH$_2$NH)

abstract:
  We conducted survey observations of a glycine precursor, methanimine or
methylenimine (CH$_2$NH), with the NRO 45 m telescope and the SMT telescope
towards 12 high-mass and two low-mass star-forming regions in order to increase
number of CH$_2$NH sources and to better understand the characteristics of
CH2NH sources. As a result of our survey, CH$_2$NH was detected in eight
sources, including four new sources. The estimated fractional abundances were
~10$^8$ in Orion KL and G10.47+0.03, while they were ~10$^9$ towards the other
sources. Our hydrogen recombination line and past studies suggest that
CH$_2$NH-rich sources have less evolved HII regions. The less destruction rates
by UV flux from the central star would be contributed to the high CH$_2$NH
abundances towards CH$_2$NH-rich sources. Our gas-grain chemical simulations
suggest that CH$_2$NH is mostly formed in the gas-phase by neutral-neutral
reactions rather than the product of thermal evaporation from the dust
surfaces.


title: Point counting on curves using a gonality preserving lift

abstract:
  We study the problem of lifting curves from finite fields to number fields in
a genus and gonality preserving way. More precisely, we sketch how this can be
done efficiently for curves of gonality at most four, with an in-depth
treatment of curves of genus at most five over finite fields of odd
characteristic, including an implementation in Magma. We then use such a lift
as input to an algorithm due to the second author for computing zeta functions
of curves over finite fields using $p$-adic cohomology.


title: Effect of plate roughness on the field near RPC plates

abstract:
  The inner surfaces of the electrodes encompassing the gas volume of a
Resistive Plate Chamber (RPC) have been found to exhibit asperities with,
grossly, three kinds of features. The desired uniform electric field within the
gas volume of RPC is expected to be affected due to the presence of these
asperities, which will eventually affect the final response from the detector.
In this work, an attempt has been made to model the highly complex roughness of
the electrode surfaces and compute its effect on the electrostatic field within
RPC gas chamber. The calculations have been performed numerically using Finite
Element Method (FEM) and Boundary Element Method (BEM) and the two methods have
been compared in this context.


title: Fast Bilateral Filtering of Vector-Valued Images

abstract:
  In this paper, we consider a natural extension of the edge-preserving
bilateral filter for vector-valued images. The direct computation of this
non-linear filter is slow in practice. We demonstrate how a fast algorithm can
be obtained by first approximating the Gaussian kernel of the bilateral filter
using raised-cosines, and then using Monte Carlo sampling. We present
simulation results on color images to demonstrate the accuracy of the algorithm
and the speedup over the direct implementation.


title:
Wave equation for generalized Zener model containing complex order
  fractional derivatives

abstract:
  We study waves in a viscoelastic rod whose constitutive equation is of
generalized Zener type that contains fractional derivatives of complex order.
The restrictions following from the Second Law of Thermodynamics are derived.
The initial-boundary value problem for such materials is formulated and
solution is presented in the form of convolution. Two specific examples are
analyzed.


title: The evolution of conditional moral assessment in indirect reciprocity

abstract:
  Indirect reciprocity is a major mechanism in the maintenance of cooperation
among unrelated individuals. Indirect reciprocity leads to conditional
cooperation according to social norms that discriminate the good (those who
deserve to be rewarded with help) and the bad (those who should be punished by
refusal of help). Despite intensive research, however, there is no definitive
consensus on what social norms best promote cooperation through indirect
reciprocity, and it remains unclear even how those who refuse to help the bad
should be assessed. Here, we propose a new simple norm called "Staying" that
prescribes abstaining from assessment. Under the Staying norm, the image of the
person who makes the decision to give help stays the same as in the last
assessment if the person on the receiving end has a bad image. In this case,
the choice about whether or not to give help to the potential receiver does not
affect the image of the potential giver. We analyze the Staying norm in terms
of evolutionary game theory and demonstrate that Staying is most effective in
establishing cooperation compared to the prevailing social norms, which rely on
constant monitoring and unconditional assessment. The application of Staying
suggests that the strict application of moral judgment is limited.


title: Charge Distribution Dependency on Gap Thickness of CMS Endcap RPC

abstract:
  We report a systematic study of charge distribution dependency of CMS
Resistive Plate Chamber (RPC) on gap thickness. Prototypes of double-gap RPCs
with six different gap thickness ranging from from 1.0 to 2.0 mm in 0.2-mm
steps have been built with 2-mm-thick phenolic high-pressure-laminated plates.
The efficiencies of the six gaps are measured as a function of the effective
high voltages. We report that the strength of the electric fields of the gap is
decreased as the gap thickness is increased. The distributions of charges in
six gaps are measured. The space charge effect is seen in the charge
distribution at the higher voltages. The logistic function is used to fit the
charge distribution data. Smaller charges can be produced within smaller gas
gap. But the digitization threshold should be also lowered to utilize these
smaller charges.


title:
Solving generalized maximum-weight connected subgraph problem for
  network enrichment analysis

abstract:
  Network enrichment analysis methods allow to identify active modules without
being biased towards a priori defined pathways. One of mathematical
formulations of such analysis is a reduction to a maximum-weight connected
subgraph problem. In particular, in analysis of metabolic networks a
generalized maximum-weight connected subgraph (GMWCS) problem, where both nodes
and edges are scored, naturally arises. Here we present the first to our
knowledge practical exact GMWCS solver. We have tested it on real-world
instances and compared to similar solvers. First, the results show that on
node-weighted instances GMWCS solver has a similar performance to the best
solver for that problem. Second, GMWCS solver is faster compared to the closest
analogue when run on GMWCS instances with edge weights.


title:
Why is there no von Neumann probe on Ceres? Error catastrophe can
  explain the Fermi-Hart Paradox

abstract:
  It has been argued that self-replicating robotic probes could spread to all
stars of our galaxy within a timespan that is tiny on cosmological scales, even
if they travel well below the speed of light. The apparent absence of such von
Neumann probes in our own solar system then needs an explanation that holds for
all possible extraterrestrial civilisations. Here I propose such a solution,
which is based on a runaway error propagation that can occur in any
self-replicating system with finite accuracy of its components. Under
universally applicable assumptions (finite resources and finite lifespans) it
follows that an optimal probe design always leads to an error catastrophe and
breakdown of the probes. Thus, there might be many advanced civilizations in
our galaxy, each surrounded by their own small sphere of self-replicating
probes. But unless our own solar system has the extraordinary luck to be close
enough to one of these civilizations, none of these probes will ever reach us.


title:
Distribution of waiting times between superoperator quantum jumps in
  Lindblad dynamics

abstract:
  Time-evolution of open, dissipative quantum system is a stochastic process
that consists of a series of quantum jumps that take place at random times.
Between quantum jumps quantum system idles for some time in a particular
quantum state. Based on superfermion/superboson formalism and general
Kossakowski- Lindblad master equation for an open quantum system we develop a
method to compute distribution of waiting times between quantum jumps. We
illustrate the use of the theory by computing waiting time distribution for
model Fermi-system in thermodynamic equilibrium.


title:
Absolutely Convex, Uniformly Starlike and Uniformly Convex Harmonic
  Mappings

abstract:
  In this paper, we prove necessary and sufficient conditions for a
sense-preserving harmonic function to be absolutely convex in the open unit
disk. We also estimate the coefficient bound and obtain growth, covering and
area theorems for absolutely convex harmonic mappings. A natural generalization
of the classical Bernardi type operator for harmonic functions is considered
and its connection between certain classes of uniformly starlike harmonic
functions and uniformly convex harmonic functions is also investigated. At the
end, as applications, we present a number of results connected with
hypergeometric and polylogarithm functions.


title: Automating QCD amplitudes with on-shell methods

abstract:
  We review some of the modern approaches to scattering amplitude computations
in QCD and their application to precision LHC phenomenology. We emphasise the
usefulness of momentum twistor variables in parameterising general amplitudes.


title: From strong to weak coupling in holographic models of thermalization

abstract:
  We investigate the analytic structure of thermal energy-momentum tensor
correlators at large but finite coupling in quantum field theories with gravity
duals. We compute corrections to the quasinormal spectra of black branes due to
the presence of higher derivative $R^2$ and $R^4$ terms in the action, focusing
on the dual to $\mathcal{N}=4$ SYM theory and Gauss-Bonnet gravity. We observe
the appearance of new poles in the complex frequency plane at finite coupling.
The new poles interfere with hydrodynamic poles of the correlators leading to
the breakdown of hydrodynamic description at a coupling-dependent critical
value of the wave-vector. The dependence of the critical wave vector on the
coupling implies that the range of validity of the hydrodynamic description
increases monotonically with the coupling. The behavior of the quasinormal
spectrum at large but finite coupling may be contrasted with the known
properties of the hierarchy of relaxation times determined by the spectrum of a
linearized kinetic operator at weak coupling. We find that the ratio of a
transport coefficient such as viscosity to the relaxation time determined by
the fundamental non-hydrodynamic quasinormal frequency changes rapidly in the
vicinity of infinite coupling but flattens out for weaker coupling, suggesting
an extrapolation from strong coupling to the kinetic theory result. We note
that the behavior of the quasinormal spectrum is qualitatively different
depending on whether the ratio of shear viscosity to entropy density is greater
or less than the universal, infinite coupling value of $\hbar/4\pi k_B$. In the
former case, the density of poles increases, indicating a formation of branch
cuts in the weak coupling limit, and the spectral function shows the appearance
of narrow peaks. We also discuss the relation of the viscosity-entropy ratio to
conjectured bounds on relaxation time in quantum systems.

categories: hep-th cond-mat.str-el hep-ph nucl-th physics.flu-dyn


title: Subgraph Isomorphism in Temporal Networks

abstract:
  Temporal information is increasingly available as part of large network data
sets. This information reveals sequences of link activations between network
entities, which can expose underlying processes in the data. Examples include
the dissemination of information through a social network, the propagation of
musical ideas in a music sampling network, and the spread of a disease via
contacts between infected and susceptible individuals. The search for these
more meaningful patterns may be formulated as a time-respecting subgraph
isomorphism problem. Our set of query graphs include an enumeration of small
random graphs and fan-out-fan-in structures, all composed of time-respecting
paths. We explore three methods of solving the problem, which differ in how
they exploit temporal and topological information. One approach extracts all
subgraphs that have the temporal properties we require and then performs
subgraph isomorphism testing on each subgraph. Another approach performs
subgraph isomorphism testing first with temporal post-filtering, while the
other is a hybrid approach that uses temporal information during the search. We
empirically demonstrate the hybrid approach to be more efficient than the
others, over a range of network data sets. These data come from communication
and social networks, up to interactions in size.


title: Asymptotics of Input-Constrained Erasure Channel Capacity

abstract:
  In this paper, we examine an input-constrained erasure channel and we
characterize the asymptotics of its capacity when the erasure rate is low. More
specifically, for a general memoryless erasure channel with its input supported
on an irreducible finite-type constraint, we derive partial asymptotics of its
capacity, using some series expansion type formulas of its mutual information
rate; and for a binary erasure channel with its first-order Markovian input
supported on the $(1, \infty)$-RLL constraint, based on the concavity of its
mutual information rate with respect to some parameterization of the input, we
numerically evaluate its first-order Markov capacity and further derive its
full asymptotics. The asymptotics obtained in this paper, when compared with
the recently derived feedback capacity for a binary erasure channel with the
same input constraint, enable us to draw the conclusion that feedback may
increase the capacity of an input-constrained channel, even if the channel is
memoryless.


title:
Generalised monogamy relation of convex-roof extended negativity in
  multi-level systems

abstract:
  In this paper, we investigate the generalised monogamy inequalities of
convex-roof extended negativity (CREN) in multi-level systems. The generalised
monogamy inequalities provide the upper and lower bounds of bipartite
entanglement, which are obtained by using CREN and the CREN of assistance
(CRENOA). Furthermore, we show that the CREN of multi-qubit pure states
satisfies some monogamy relations. Additionally, we test the generalised
monogamy inequalities for qudits by considering the partially coherent
superposition of a generalised W-class state in a vacuum and show that the
generalised monogamy inequalities are satisfied in this case as well.


title:
A new second-order midpoint approximation formula for Riemann-Liouville
  derivative: algorithm and its application

abstract:
  Compared to the the classical first-order Gr\"unwald-Letnikov formula at time
$t_{k+1} (\textmd{or}\, t_{k})$, we firstly propose a second-order numerical
approximate scheme for discretizing the Riemann-Liouvile derivative at time
$t_{k+\frac{1}{2}}$, which is very suitable for constructing the Crank-Niclson
technique applied to the time-fractional differential equations. The
established formula has the following form $$ \begin{array}{lll} \displaystyle
\,_{\mathrm{RL}}{{{\mathrm{D}}}}_{0,t}^{\alpha}u\left(t\right)\left|\right._{t=t_{k+\frac{1}{2}}}=
\tau^{-\alpha}\sum\limits_{\ell=0}^{k}
\varpi_{\ell}^{(\alpha)}u\left(t_k-\ell\tau\right)
+\mathcal{O}(\tau^2),\,\,k=0,1,\ldots, \alpha\in(0,1), \end{array} $$ where the
coefficients $\varpi_{\ell}^{(\alpha)}$ $(\ell=0,1,\ldots,k)$ can be determined
via the following generating function
  $$ \begin{array}{lll} \displaystyle
G(z)=\left(\frac{3\alpha+1}{2\alpha}-\frac{2\alpha+1}{\alpha}z+\frac{\alpha+1}{2\alpha}z^2\right)^{\alpha},\;|z|<1.
\end{array} $$ Applying this formula to the time fractional Cable equations
with Riemann-liouville derivative in one or two space dimensions. Then the
high-order compact finite difference schemes are obtained. The solvability,
stability and convergence with orders $\mathcal{O}(\tau^2+h^4)$ and
$\mathcal{O}(\tau^2+h_x^4+h_y^4)$ are shown, where $\tau$ is the temporal
stepsize and $h$, $h_x$, $h_y$ are the spatial stepsizes, respectively.
Finally, numerical experiments are provided to support the theoretical
analysis.


title:
Fast and High-Quality Bilateral Filtering Using Gauss-Chebyshev
  Approximation

abstract:
  The bilateral filter is an edge-preserving smoother that has diverse
applications in image processing, computer vision, computer graphics, and
computational photography. The filter uses a spatial kernel along with a range
kernel to perform edge-preserving smoothing. In this paper, we consider the
Gaussian bilateral filter where both the kernels are Gaussian. A direct
implementation of the Gaussian bilateral filter requires $O(\sigma_s^2)$
operations per pixel, where $\sigma_s$ is the standard deviation of the spatial
Gaussian. In fact, it is well-known that the direct implementation is slow in
practice. We present an approximation of the Gaussian bilateral filter, whereby
we can cut down the number of operations to $O(1)$ per pixel for any arbitrary
$\sigma_s$, and yet achieve very high-quality filtering that is almost
indistinguishable from the output of the original filter. We demonstrate that
the proposed approximation is few orders faster in practice compared to the
direct implementation. We also demonstrate that the approximation is
competitive with existing fast algorithms in terms of speed and accuracy.


title:
Thin film growth of a topological crystal insulator SnTe on the CdTe
  (111) surface by molecular beam epitaxy

abstract:
  We report molecular beam epitaxial growth of a SnTe (111) layer on a CdTe
template, fabricated by depositing it on a GaAs (111)A substrate, instead of
BaF$_2$ which has been conventionally used as a substrate. By optimizing
temperatures for the growth of both SnTe and CdTe layers, we could obtain SnTe
layers of the single phase grown only in the (111) orientation and of much
improved surface morphology from the viewpoint of the extension and the
flatness of flat regions, compared to the layers grown on BaF$_2$. In this
optimal growth condition, we have also achieved a low hole density of the order
of 10$^{17}$cm$^{-3}$ at 4K, the lowest value ever reported for SnTe thin films
without additional doping. In the magnetoresistance measurement on this
optimized SnTe layer, we observe characteristic negative magneto-conductance
which is attributed to the weak antilocalization effect of the two-dimensional
transport in the topological surface state.


title: Quest for potentials in the quintessence scenario

abstract:
  The time variation of the equation of state $w$ for quintessence scenario
with a scalar field as dark energy is studied up to the third derivative
($d^3w/da^3$) with respect to the scale factor $a$, in order to predict the
future observations and specify the scalar potential parameters with the
observables. The third derivative of $w$ for general potential $V$ is derived
and applied to several types of potentials. They are the inverse power-law
($V=M^{4+\alpha}/Q^{\alpha}$), the exponential ($V=M^4\exp{(\beta M/Q)}$), the
cosine ($V=M^4(\cos (Q/f)+1)$) and the Gaussian types
($V=M^4\exp(-Q^2/\sigma^2)$), which are prototypical potentials for the
freezing and thawing models.
  If the parameter number for a potential form is $ n$, it is necessary to find
at least for $n+2$ independent observations to identify the potential form and
the evolution of the scalar field ($Q$ and $ \dot{Q} $).
  Such observations would be the values of $ \Omega_Q, w, dw/da. \cdots $, and
$ dw^n/da^n$.
  Since four of the above mentioned potentials have two parameters, it is
necessary to calculate the third derivative of $w$ for them to estimate the
predict values.
  If they are tested observationally, it will be understood whether the dark
energy could be described by the scalar field with this potential.
  Numerical analysis for $d^3w/da^3$ are made under some specified parameters
in the investigated potentials.
  It becomes possible to distinguish the freezing and thawing modes by the
accurate observing $dw/da$ and $d^2w/da^2$ in some parameters.


title: "Counterfactual" quantum protocols

abstract:
  The counterfactuality of recently proposed protocols is analyzed. A
definition of `counterfactuality' is offered and it is argued that an
interaction-free measurement of the presence of an opaque object can be named
`counterfactual', while proposed "counterfactual" measurements of the absence
of such objects are not counterfactual. The quantum key distribution protocols
which rely only on measurements of the presence of the object are
counterfactual, but quantum direct communication protocols are not. Therefore,
the name `counterfactual' is not appropriate for recent "counterfactual"
protocols which transfer quantum states by quantum direct communication.


title: Shot noise in the edge states of 2D topological insulators

abstract:
  We calculate the resistance and shot noise in the edge states of a 2D
topological insulator that result from the exchange of electrons between these
states and conducting puddles in the bulk of the insulator. The two limiting
cases where the energy relaxation is either absent or very strong are
considered. A finite time of spin relaxation in the puddles is introduced
phenomenologically. Depending on this time and on the strength of coupling
between the edge states and the puddles, the Fano factor $F=S_I/2eI$ ranges
from 0 to 1/3, which is in an agreement with the available experimental data.


title:
Importance of resonance widths in low-energy scattering of weakly-bound
  light-mass nuclei

abstract:
  What effect do particle-emitting resonances have on the scattering cross
section? What physical considerations are necessary when modelling these
resonances? These questions are important when theoretically describing
scattering experiments with radioactive ion beams which investigate the
frontiers of the table of nuclides, far from stability. Herein, a novel method
is developed that describes resonant nuclear scattering from which centroids
and widths in the compound nucleus are obtained when one of the interacting
bodies has particle unstable resonances. The method gives cross sections
without unphysical behavior that is found if simple Lorentzian forms are used
to describe resonant target states. The resultant cross sections differ
significantly from those obtained when the states in the coupled channel
calculations are taken to have zero width, and compound-system resonances are
better matched to observed values.


title: Charged compact stellar model in Finch-Skea spacetime

abstract:
  In this paper a compact charged stellar model in the Finch and Skea
background spacetime [{\it Class. Quantum Gravity} {\bf6}, 467 (1989)] is
presented. The model has been developed by assuming a particular charge
distribution within the stellar interior. The model is well behaved and can
describe a large class of compact stars. Physical features of the model are
studied and in particular we show how the presence of charge can have a
non-negligible impact on the mass-radius ($M-R$) relationship of such class of
stars.


title: Stateless Model Checking for POWER

abstract:
  We present the first framework for efficient application of stateless model
checking (SMC) to programs running under the relaxed memory model of POWER. The
framework combines several contributions. The first contribution is that we
develop a scheme for systematically deriving operational execution models from
existing axiomatic ones. The scheme is such that the derived execution models
are well suited for efficient SMC. We apply our scheme to an axiomatic model of
POWER. Our main contribution is a technique for efficient SMC, called Relaxed
Stateless Model Checking (RSMC), which systematically explores the possible
inequivalent executions of a program. RSMC is suitable for execution models
obtained using our scheme. We prove that RSMC is sound and optimal for the
POWER memory model, in the sense that each complete program behavior is
explored exactly once. We show the feasibility of our technique by providing an
implementation for programs written in C/pthreads.


title: Rescaling of spatio-temporal sensing in eukaryotic chemotaxis

abstract:
  Eukaryotic cells respond to a chemoattractant gradient by forming
intracellular gradients of signaling molecules that reflect the extracellular
chemical gradient - an ability called directional sensing. Quantitative
experiments have revealed two characteristic input-output relations of the
system: First, in a static chemoattractant gradient, the shapes of the
intracellular gradients of the signaling molecules are determined by the
relative steepness, rather than the absolute concentration, of the
chemoattractant gradient along the cell body. Second, upon a spatially
homogeneous temporal increase in the input stimulus, the intracellular
signaling molecules are transiently activated such that the response magnitudes
are dependent on fold changes of the stimulus, not on absolute levels. However,
the underlying mechanism that endows the system with these response properties
remains elusive. Here, by adopting a widely used modeling framework of
directional sensing, local excitation and global inhibition (LEGI), we propose
a hypothesis that the two rescaling behaviors stem from a single design
principle, namely, invariance of the governing equations to a scale
transformation of the input level. Analyses of the LEGI-based model reveal that
the invariance can be divided into two parts, each of which is responsible for
the respective response properties. Our hypothesis leads to an experimentally
testable prediction that a system with the invariance detects relative
steepness even in dynamic gradient stimuli as well as in static gradients.
Furthermore, we show that the relation between the response properties and the
scale invariance is general in that it can be implemented by models with
different network topologies.


title:
Structure of $^{23}$Al from a multi-channel algebraic scattering model
  based on mirror symmetry

abstract:
  The proton-rich nucleus $^{23}$Al has a ground state just 123 keV below the
proton drip-line, and as a result comparatively little is known experimentally
about its properties, as with many such nuclei. Theoretical investigations have
tended to model exclusively the ground and first one to three excited states
known. In this paper, we theoretically model most of the known spectrum, and
predict what states may as yet be unobserved. We use the multichannel algebraic
scattering (MCAS) method to describe states as resonances of a valence proton
coupled to a $^{22}$Mg rotor core. Six states with low-excitation energies and
defined $J^\pi$ are matched, and we make the first prediction of the properties
of four others and propound the possible existence of several more.


title:
Forecasting time series with structural breaks with Singular Spectrum
  Analysis, using a general form of recurrent formula

abstract:
  This study extends and evaluates the forecasting performance of the Singular
Spectrum Analysis (SSA) technique using a general non-linear form for the re-
current formula. In this study, we consider 24 series measuring the monthly
seasonally adjusted industrial production of important sectors of the German,
French and UK economies. This is tested by comparing the performance of the new
proposed model with basic SSA and the SSA bootstrap forecasting, especially
when there is evidence of structural breaks in both in-sample and out-of-sample
periods. According to root mean-square error (RMSE), SSA using the general
recursive formula outperforms both the SSA and the bootstrap forecasting at
horizons of up to a year. We found no significant difference in predicting the
direction of change between these methods. Therefore, it is suggested that the
SSA model with the general recurrent formula should be chosen by users in the
case of structural breaks in the series.


title: Effect of glass thickness variations on the performance of RPC detectors

abstract:
  The India-based Neutrino Observatory (INO) is planning to build a magnetized
iron calorimeter detector (ICAL) in which Resistive Plate Chambers (RPCs) will
be the active detector elements. A study of the performance of RPCs, made using
electrodes of various thicknesses, is pivotal in optimizing the design
parameters of the ICAL RPCs. We fabricated RPCs with glasses of various
thicknesses and studied their performance in the same environmental conditions.
A study of detector efficiency, noise rate, time resolution and charge
distribution is presented in this paper.


title: Matching models across abstraction levels with Gaussian Processes

abstract:
  Biological systems are often modelled at different levels of abstraction
depending on the particular aims/resources of a study. Such different models
often provide qualitatively concordant predictions over specific
parametrisations, but it is generally unclear whether model predictions are
quantitatively in agreement, and whether such agreement holds for different
parametrisations. Here we present a generally applicable statistical machine
learning methodology to automatically reconcile the predictions of different
models across abstraction levels. Our approach is based on defining a
correction map, a random function which modifies the output of a model in order
to match the statistics of the output of a different model of the same system.
We use two biological examples to give a proof-of-principle demonstration of
the methodology, and discuss its advantages and potential further applications.


title:
Chaotic Griffiths Phase with Anomalous Lyapunov Spectra in Coupled Map
  Networks

abstract:
  Dynamics of coupled chaotic oscillators on a network are studied using
coupled maps. Within a broad range of parameter values representing the
coupling strength or the degree of elements, the system repeats formation and
split of coherent clusters. The distribution of the cluster size follows a
power law with the exponent $\alpha$, which changes with the parameter values.
The number of positive Lyapunov exponents and their spectra are scaled
anomalously with the power of the system size with the exponent $\beta$, which
also changes with the parameters. The scaling relation $\alpha \sim 2(\beta
+1)$ is uncovered, which seems to be universal independent of parameters and
networks.


title: The motion of a random string

abstract:
  We review a series of forthcoming results leading to the construction of a
natural evolution on the space of loops with values in a Riemannian manifold.
In particular, this clarifies the algebraic structure of the renormalisation
procedures appearing in the context of the theory of regularity structures.


title:
Quantum gravitational interaction between a polarizable object and a
  boundary

abstract:
  We investigate the interaction caused by quantum gravitational vacuum
fluctuations between a gravitationally polarizable object and a gravitational
boundary, and find a position-dependent energy shift of the object, which
induces a force in close analogy to the Casimir-Polder force in the
electromagnetic case. For a Dirichlet boundary, the explicit form of the
quantum gravitational potential for the polarizable object in its ground-state
is worked out and is found to behave like $z^{-5}$ in the near regime, and
$z^{-6}$ in the far regime, where $z$ is the distance to the boundary. Taking a
Bose-Einstein condensate as a gravitationally polarizable object, we find that
the relative correction to the radius caused by fluctuating quantum
gravitational waves in vacuum is of order $10^{-21}$. Although far too small to
observe in comparison with its electromagnetic counterpart, it is nevertheless
of the order of the gravitational strain caused by a recently detected black
hole merger on the arms of the LIGO.


title:
The host galaxy properties of variability selected AGN in the
  Pan-STARRS1 Medium-Deep Survey

abstract:
  We study the properties of 975 active galactic nuclei (AGN) selected by
variability in the Pan-STARRS1 Medium-Deep Survey. Using complementary multi
wavelength data from the ultraviolet to the far-infrared, we use SED fitting to
determine the AGN and host properties at $z<1$, and compare to a well-matched
control sample. We confirm the trend previously observed that the variability
amplitude decreases with AGN luminosity, but on the other hand, we observe that
the slope of this relation steepens with wavelength resulting in a "redder when
brighter" trend at low luminosities. Our results show that AGN are hosted by
more massive hosts than control sample galaxies, while the restframe,
dust-corrected $NUV-r$ color distribution of AGN hosts is similar to control
galaxies. We find a positive correlation between the AGN luminosity and star
formation rate (SFR), independent of redshift. AGN hosts populate the whole
range of SFRs within and outside the Main Sequence of star forming galaxies.
Comparing the distribution of AGN hosts and control galaxies, we show that AGN
hosts are less likely to be hosted by quiescent galaxies, but more likely to be
hosted by Main Sequence or starburst galaxies.


title:
Robust Low-Bias Negative Differential Resistance in Graphene
  Superlattices

abstract:
  Here, we present a detailed study on low bias current-voltage (I-V)
characteristic of graphene superlattice (GSL) resonant tunneling diode (RTD)
with heterostructured substrate and series of grounded metallic planes placed
over graphene sheet which induce periodically modulated Dirac gap and Fermi
velocity barrier. We investigate the effect of GSL parameters on I-V
characteristics within the Landauer-Buttiker formalism and adopted transfer
matrix method. We show how the engineering these parameters results in
multipeak NDR in proposed device. Moreover we provide a novel venue to control
the NDR in GSL with Fermi velocity engineering. From this viewpoint we obtain
multipeak NDR through miniband align in GSL. Maximum Pick to Valley ratio (PVR)
up to 167 obtained for correlation velocity of 1.9 and bias voltages between
70-130 mV. Our finding in low bias regime and high PVR multipeak NDR have a
considerable importance in multi-valued memory functional circuit, low power
and high-speed nanoelectronic devices application.


title:
All Weather Perception: Joint Data Association, Tracking, and
  Classification for Autonomous Ground Vehicles

abstract:
  A novel probabilistic perception algorithm is presented as a real-time joint
solution to data association, object tracking, and object classification for an
autonomous ground vehicle in all-weather conditions. The presented algorithm
extends a Rao-Blackwellized Particle Filter originally built with a particle
filter for data association and a Kalman filter for multi-object tracking
(Miller et al. 2011a) to now also include multiple model tracking for
classification. Additionally a state-of-the-art vision detection algorithm that
includes heading information for autonomous ground vehicle (AGV) applications
was implemented. Cornell's AGV from the DARPA Urban Challenge was upgraded and
used to experimentally examine if and how state-of-the-art vision algorithms
can complement or replace lidar and radar sensors. Sensor and algorithm
performance in adverse weather and lighting conditions is tested. Experimental
evaluation demonstrates robust all-weather data association, tracking, and
classification where camera, lidar, and radar sensors complement each other
inside the joint probabilistic perception algorithm.


title: Effect of group organization on the performance of cooperative processes

abstract:
  Problem-solving competence at group level is influenced by the structure of
the social networks and so it may shed light on the organization patterns of
gregarious animals. Here we use an agent-based model to investigate whether the
ubiquity of hierarchical networks in nature could be explained as the result of
a selection pressure favoring problem-solving efficiency. The task of the
agents is to find the global maxima of NK fitness landscapes and the agents
cooperate by broadcasting messages informing on their fitness to the group.
This information is then used to imitate, with a certain probability, the
fittest agent in their influence networks. For rugged landscapes, we find that
the modular organization of the hierarchical network with its high degree of
clustering eases the escape from the local maxima, resulting in a superior
performance as compared with the scale-free and the random networks. The
optimal performance in a rugged landscape is achieved by letting the main hub
to be only slightly more propense to imitate the other agents than vice versa.
The performance is greatly harmed when the main hub carries out the search
independently of the rest of the group as well as when it compulsively imitates
the other agents.


title: A result on the equation $x^p + y^p = z^r$ using Frey abelian varieties

abstract:
  We prove a diophantine result on generalized Fermat equations of the form
$x^p + y^p = z^r$ which for the first time requires the use of Frey abelian
varieties of dimension $\geq 2$ in Darmon's program. For that, we provide an
irreducibility criterion for the mod $\mathfrak{p}$ representations attached to
certain abelian varieties of $\text{GL}_2$-type over totally real fields.


title:
Intrinsic Paramagnetic Meissner Effect due to s-wave Odd-Frequency
  Superconductivity

abstract:
  In 1933, Meissner and Ochsenfeld reported the expulsion of magnetic flux, the
diamagnetic Meissner effect, from the interior of superconducting lead. This
discovery was crucial in formulating the Bardeen-Cooper-Schrieffer (BCS) theory
of superconductivity. In exotic superconducting systems BCS theory does not
strictly apply. A classical example is a superconductor-magnet hybrid system
where magnetic ordering breaks time-reversal symmetry of the superconducting
condensate and results in the stabilisation of an odd-frequency superconducting
state. It has been predicted that under appropriate conditions, odd-frequency
superconductivity should manifest in the Meissner state as fluctuations in the
sign of the magnetic susceptibility meaning that the superconductivity can
either repel (diamagnetic) or attract (paramagnetic) external magnetic flux.
Here we report local probe measurements of faint magnetic fields in a Au/Ho/Nb
trilayer system using low energy muons, where antiferromagnetic Ho (4.5 nm)
breaks time-reversal symmetry of the proximity induced pair correlations in Au.
From depth-resolved measurements below the superconducting transition of Nb we
observe a local enhancement of the magnetic field in Au that exceeds the
externally applied field, thus proving the existence of an intrinsic
paramagnetic Meissner effect arising from an odd-frequency superconducting
state.


title: On the minimizers of the fusion frame potential

abstract:
  We study the minimizers of the fusion frame potential in the case that both
the weights and the dimensions of the subspaces are fixed and not necessarily
equal. Using a concept of irregularity we provide a description of the local
(that are also global) minimizers which projections are eigenoperators of the
fusion frame operator. This result will be related to the existence of tight
fusion frames. In this way we generalize results known for the classical vector
frame potential.


title:
A metamaterial modulator based on electrically controllable
  electromagnetically induced transparency

abstract:
  Electromagnetically induced transparency (EIT) is a promising technology for
the enhancement of light-matter interactions, and recent demonstrations of the
quantum EIT realized in artificial micro-structured medium have remarkably
reduced the extreme requirement for experimental observation of EIT spectrum.
In this paper, we propose to electrically control the EIT spectrum in a
metamaterial for an electromagnetic modulator. A diode acting as a tunable
resistor is loaded in the gap of two paired wires to inductively tune the
magnetic resonance, which induces remarkable modulation on the EIT spectrum
through the metamaterial sample. The experimental measurements confirmed that
the prediction of electromagnetic modulation in three narrow bands on the EIT
spectrum, and a modulation contrast of up to 31 dB was achieved on the
transmission through the metamaterial. Our results may facilitate the study on
active/dynamical technology in translational metamaterials, which connect
extraordinary manipulations on the flow of light in metamaterials, e.g., the
exotic EIT, and practical applications in industry.


title: Entropy-reducing dynamics of a double demon

abstract:
  We study the reduction in total entropy, and associated conversion of
environmental heat into work, arising from the coupling and decoupling of two
systems followed by processing determined by suitable mutual feedback. The
scheme is based on the actions of Maxwell's demon, namely the performance of a
measurement on a system followed by an exploitation of the outcome to extract
work. When this is carried out in a symmetric fashion, with each system
informing the exploitation of the other (and both therefore acting as a demon),
it may be shown that the second law can be broken, a consequence of the
self-sorting character of the system dynamics.


title:
Quantum Interference Effects in Topological Nanowires In a Longitudinal
  Magnetic Field

abstract:
  We study the magnetoconductance of topological insulator nanowires in a
longitudinal magnetic field, including Aharonov-Bohm, Altshuler-Aronov-Spivak,
perfectly conducting channel, and universal conductance fluctuation effects.
Our focus is on predicting experimental behavior in single wires in the quantum
limit where temperature is reduced to zero. We show that changing the Fermi
energy $E_F$ can tune a wire from from ballistic to diffusive conduction and to
localization. In both ballistic and diffusive single wires we find both
Aharonov-Bohm and Altshuler-Aronov-Spivak oscillations with similar strengths,
accompanied by quite strong universal conductance fluctuations (UCFs), all with
amplitudes between $0.3 \, G_0$ and $1\,G_0$. This contrasts strongly with the
average behavior of many wires, which shows Aharonov-Bohm oscillations in the
ballistic regime and Altshuler-Aronov-Spivak oscillations in the diffusive
regime, with both oscillations substantially larger than the conductance
fluctuations. In single wires the ballistic and diffusive regimes can be
distinguished by varying $E_F$ and studying the sign of the AB signal, which
depends periodically on $E_F$ in ballistic wires and randomly on $E_F$ in
diffusive wires. We also show that in long wires the perfectly conducting
channel is visible at a wide range of energies within the bulk gap. We present
typical conductance profiles at several wire lengths, showing that conductance
fluctuations can dominate the average signal. Similar behavior will be found in
carbon nanotubes.


title: Detection of Supernova Neutrinos

abstract:
  The neutrino burst from a core-collapse supernova can provide information
about the star explosion mechanism and the mechanisms of proto neutron star
cooling but also about the intrinsic properties of the neutrino such as flavor
oscillations. One important question is to understand to which extent can the
supernova and the neutrino physics be decoupled in the observation of a single
supernova. The capabilities of present and future large underground neutrino
detectors to yield information about the time and flavor dependent neutrino
signal from a future galactic supernova are described in this paper. Neutrinos
from past cosmic supernovae are also observable and their detection will
improve our knowledge of the core-collapse rates and average neutrino emission.
A comparison between the different experimental techniques is included.

categories: physics.ins-det astro-ph.HE astro-ph.IM hep-ex hep-ph


title: Volatility Decomposition and Estimation in Time-Changed Price Models

abstract:
  The usage of a spot volatility estimate based on a volatility decomposition
in a time-changed price-model according to the trading times is investigated.
In this model clock-time volatility splits up into the product of tick-time
volatility and trading intensity, which both can be estimated from data and
contain valuable information. By inspecting these two curves individually we
gain more insight into the cause and structure of volatility. Several examples
are provided where the tick-time volatility curve is much smoother than the
clock-time volatility curve meaning that the major part of fluctuations in
clock-time volatility is due to fluctuations of the trading intensity. Since
microstructure noise only influences the estimation of the (smooth) tick-time
volatility curve, the findings lead to an improved pre-averaging estimator of
spot volatility. This is reflected by a better rate of convergence of the
estimator. The asymptotic properties of the estimators are derived by an infill
asymptotic approach.


title: Type Theory based on Dependent Inductive and Coinductive Types

abstract:
  We develop a dependent type theory that is based purely on inductive and
coinductive types, and the corresponding recursion and corecursion principles.
This results in a type theory with a small set of rules, while still being
fairly expressive. For example, all well-known basic types and type formers
that are needed for using this type theory as a logic are definable:
propositional connectives, like falsity, conjunction, disjunction, and function
space, dependent function space, existential quantification, equality, natural
numbers, vectors etc. The reduction relation on terms consists solely of a rule
for recursion and a rule for corecursion. The reduction relations for
well-known types arise from that. To further support the introduction of this
new type theory, we also prove fundamental properties of its term calculus.
Most importantly, we prove subject reduction and strong normalisation of the
reduction relation, which gives computational meaning to the terms.
  The presented type theory is based on ideas from categorical logic that have
been investigated before by the first author, and it extends Hagino's
categorical data types to a dependently typed setting. By basing the type
theory on concepts from category theory we maintain the duality between
inductive and coinductive types, and it allows us to describe, for example, the
function space as a coinductive type.


title: Signature of topological phases in Zitterbewegung

abstract:
  We have studied the {\em Zitterbewegung} effect on an infinite two
dimensional sheet with honeycomb lattice. By tuning the perpendicular electric
field and the magnetization of the sheet, it can enter different topological
phases. We have shown that the phase and magnitude of Zitterbewegung effect,
i.e. the jittering motion of relativistic particles, correlates with the
various topological phases. The topological phase diagram can be reconstructed
by analyzing these features. Our findings are applicable to materials like
silicene, germanene, stanene etc.


title:
Order-by-disorder effects in antiferromagnets on face-centered cubic
  lattice

abstract:
  We discuss the role of quantum fluctuations in Heisenberg antiferromagnets on
face-centered cubic lattice with small dipolar interaction in which the
next-nearest-neighbor exchange coupling dominates over the nearest-neighbor
one. It is well known that a collinear magnetic structure which contains (111)
ferromagnetic planes arranged antiferromagnetically along one of the space
diagonals of the cube is stabilized in this model via order-by-disorder
mechanism. On the mean-field level, the dipolar interaction forces spins to lie
within (111) planes. By considering 1/S - corrections to the ground state
energy, we demonstrate that quantum fluctuations lead to an anisotropy within
(111) planes favoring three equivalent directions for the staggered
magnetization (e.g., $[11\overline{2}]$, $[1\overline{2}1]$, and
$[\overline{2}11]$ directions for (111) plane). Such in-plane anisotropy was
obtained experimentally in related materials MnO, $\alpha$-MnS, $\alpha$-MnSe,
EuTe, and EuSe. We find that the order-by-disorder mechanism can contribute
significantly to the value of the in-plane anisotropy in EuTe. Magnon spectrum
is also derived in the first order in 1/S.


title: Revisiting Simpson's Paradox: a statistical misspecification perspective

abstract:
  The primary objective of this paper is to revisit Simpson's paradox using a
statistical misspecification perspective. It is argued that the reversal of
statistical associations is sometimes spurious, stemming from invalid
probabilistic assumptions imposed on the data. The concept of statistical
misspecification is used to formalize the vague term `spurious results' as
`statistically untrustworthy' inference results. This perspective sheds new
light on the paradox by distingusing between statistically trustworthy vs.
untrustworthy association reversals. It turns out that in both cases there is
nothing counterintuitive to explain or account for. This perspective is also
used to revisit the causal `resolution' of the paradox in an attempt to
delineate the modeling and inference issues raised by the statistical
misspecification perspective. The main arguments are illustrated using both
actual and hypothetical data from the literature, including Yule's
"nonsense-correlations" and the Berkeley admissions study.


title: Inference-based semantics in Data Exchange

abstract:
  Data Exchange is an old problem that was firstly studied from a theoretical
point of view only in 2003. Since then many approaches were considered when it
came to the language describing the relationship between the source and the
target schema. These approaches focus on what it makes a target instance a
"good" solution for data-exchange. In this paper we propose the inference-based
semantics that solves many certain-answer anomalies existing in current
data-exchange semantics. To this we introduce a new mapping language between
the source and the target schema based on annotated bidirectional dependencies
(abd) and, consequently define the semantics for this new language. It is shown
that the ABD-semantics can properly represent the inference-based semantics,
for any source-to-target mappings. We discovered three dichotomy results under
the new semantics for solution-existence, solution-check and UCQ evaluation
problems. These results rely on two factors describing the annotation used in
the mappings (density and cardinality). Finally we also investigate the
certain-answers evaluation problem under ABD-semantics and discover many
tractable classes for non-UCQ queries even for a subclass of CQ with negation.


title:
Star formation activity in the neighbourhood of W-R 1503-160L star in
  the mid-infrared bubble N46

abstract:
  In order to investigate star formation (SF) processes in extreme
environments, we have carried out a multi-wavelength analysis of the
mid-infrared bubble N46, which hosts a WN7 Wolf-Rayet (W-R) star. We have used
13CO line data to trace an expanding shell surrounding the W-R star containing
about five condensations within the molecular cloud associated with the bubble.
The W-R star is associated with a powerful stellar wind having a mechanical
luminosity of ~4 x 10^37 ergs/s. A deviation of the H-band starlight mean
polarization angles around the bubble has also been traced, indicating the
impact of stellar wind on the surroundings. The Herschel temperature map shows
a temperature range of ~18 - 24 K toward the five molecular condensations. The
photometric analysis reveals that these condensations are associated with the
identified clusters of young stellar objects, revealing ongoing SF process. The
densest among these five condensations (peak N(H_2) ~9.2 x 10^22 cm^-2 and A_V
~ 98 mag) is associated with a 6.7 GHz methanol maser, an infrared dark cloud,
and the CO outflow, tracing active massive SF within it. At least five compact
radio sources (crss) are physically linked with the edges of the bubble and
each of them is consistent with the radio spectral class of a B0V - B0.5V type
star. The ages of the individual infrared counterparts of three crss (~1 - 2
Myr) and a typical age of WN7 W-R star (~4 Myr) indicate that the SF activities
around the bubble are influenced by the feedback of the W-R star.


title:
Strong $I$ AND $I^*$-statistically pre-Cauchy double sequences in
  Probabilistic Metric Spaces

abstract:
  In this paper we consider the notion of strong $I$-statistically pre-Cauchy
double sequences in probabilistic metric spaces in line of Das et. al. [6] and
introduce the new concept of strong $I^*$-statistically pre-Cauchy double
sequences in real line as well as in probabilistic metric spaces. We mainly
study inter relationship among strong $I$-statistical convergence, strong
$I$-statistical pre-Cauchy condition and strong $I^*$-statistical pre-Cauchy
condition for double sequences in probabilistic metric spaces and examine some
basic properties of these notions.


title: Online Learning and Optimization of Markov Jump Affine Models

abstract:
  The problem of online learning and optimization of unknown Markov jump affine
models is considered. An online learning policy, referred to as Markovian
simultaneous perturbations stochastic approximation (MSPSA), is proposed for
two different optimization objectives: (i) the quadratic cost minimization of
the regulation problem and (ii) the revenue (profit) maximization problem. It
is shown that the regret of MSPSA grows at the order of the square root of the
learning horizon. Furthermore, by the use of van Trees inequality, it is shown
that the regret of any policy grows no slower than that of MSPSA, making MSPSA
an order optimal learning policy. In addition, it is also shown that the MSPSA
policy converges to the optimal control input almost surely as well as in the
mean square sense. Simulation results are presented to illustrate the regret
growth rate of MSPSA and to show that MSPSA can offer significant gain over the
greedy certainty equivalent approach.


title: On cross-validated Lasso in high dimensions

abstract:
  In this paper, we derive non-asymptotic error bounds for the Lasso estimator
when the penalty parameter for the estimator is chosen using $K$-fold
cross-validation. Our bounds imply that the cross-validated Lasso estimator has
nearly optimal rates of convergence in the prediction, $L^2$, and $L^1$ norms.
For example, we show that in the model with the Gaussian noise and under fairly
general assumptions on the candidate set of values of the penalty parameter,
the estimation error of the cross-validated Lasso estimator converges to zero
in the prediction norm with the $\sqrt{s\log p / n}\times \sqrt{\log(p n)}$
rate, where $n$ is the sample size of available data, $p$ is the number of
covariates, and $s$ is the number of non-zero coefficients in the model. Thus,
the cross-validated Lasso estimator achieves the fastest possible rate of
convergence in the prediction norm up to a small logarithmic factor
$\sqrt{\log(p n)}$, and similar conclusions apply for the convergence rate both
in $L^2$ and in $L^1$ norms. Importantly, our results cover the case when $p$
is (potentially much) larger than $n$ and also allow for the case of
non-Gaussian noise. Our paper therefore serves as a justification for the
widely spread practice of using cross-validation as a method to choose the
penalty parameter for the Lasso estimator.


title:
Formation of subject area and the co-authors network by sounding of
  Google Scholar Citations service

abstract:
  The suggested methodic is the way of formatting the subject areas models and
co-authors networks by sounding the content networks. The paper represents the
notion networks which match tags and authors of Google Scholar Citations
service. Models depicted in the work were built for the physical optics area,
and it can be applied for other domains. The proposed ways of defining
connections between science areas and authors depicts the collaborations
opportunities and versatility of interdisciplinary.


title: Distributed stochastic optimization for deep learning (thesis)

abstract:
  We study the problem of how to distribute the training of large-scale deep
learning models in the parallel computing environment. We propose a new
distributed stochastic optimization method called Elastic Averaging SGD
(EASGD). We analyze the convergence rate of the EASGD method in the synchronous
scenario and compare its stability condition with the existing ADMM method in
the round-robin scheme. An asynchronous and momentum variant of the EASGD
method is applied to train deep convolutional neural networks for image
classification on the CIFAR and ImageNet datasets. Our approach accelerates the
training and furthermore achieves better test accuracy. It also requires a much
smaller amount of communication than other common baseline approaches such as
the DOWNPOUR method.
  We then investigate the limit in speedup of the initial and the asymptotic
phase of the mini-batch SGD, the momentum SGD, and the EASGD methods. We find
that the spread of the input data distribution has a big impact on their
initial convergence rate and stability region. We also find a surprising
connection between the momentum SGD and the EASGD method with a negative moving
average rate. A non-convex case is also studied to understand when EASGD can
get trapped by a saddle point.
  Finally, we scale up the EASGD method by using a tree structured network
topology. We show empirically its advantage and challenge. We also establish a
connection between the EASGD and the DOWNPOUR method with the classical Jacobi
and the Gauss-Seidel method, thus unifying a class of distributed stochastic
optimization methods.


title:
Unusual Polar Conditions in Solar Cycle 24 and their Implications for
  Cycle 25

abstract:
  We report on the prolonged solar-maximum conditions until late 2015 at the
north-polar region of the Sun indicated by the occurrence of high-latitude
prominence eruptions and microwave brightness temperature close to the quiet
Sun level. These two aspects of solar activity indicate that the polarity
reversal was completed by mid-2014 in the south and late 2015 in the north. .
The microwave brightness in the south-polar region has increased to a level
exceeding the level of cycle 23/24 minimum, but just started to increase in the
north. The north-south asymmetry in the polarity reversal has switched from
that in cycle 23. These observations lead us to the hypothesis that the onset
of cycle 25 in the northern hemisphere is likely to be delayed with respect to
that in the southern hemisphere. We find that the unusual condition in the
north is a direct consequence of the arrival of poleward surges of opposite
polarity from the active region belt. We also find that multiple
rush-to-the-pole episodes were indicated by the prominence eruption locations
that lined up at the boundary between opposite polarity surges. The
high-latitude prominence eruptions occurred in the boundary between the
incumbent polar flux and the insurgent flux of opposite polarity.


title: Low-Frequency Radio Bursts and Space Weather

abstract:
  Low-frequency radio phenomena are due to the presence of nonthermal electrons
in the interplanetary (IP) medium. Understanding these phenomena is important
in characterizing the space environment near Earth and other destinations in
the solar system. Substantial progress has been made in the past two decades,
because of the continuous and uniform data sets available from space-based
radio and white-light instrumentation. This paper highlights some recent
results obtained on IP radio phenomena. In particular, the source of type IV
radio bursts, the behavior of type III storms, shock propagation in the IP
medium, and the solar-cycle variation of type II radio bursts are considered.
All these phenomena are closely related to solar eruptions and active region
evolution. The results presented were obtained by combining data from the Wind
and SOHO missions.


title:
Merging of positive maps: a construction of various classes of positive
  maps on matrix algebras

abstract:
  For two positive maps $\phi_i:B(\mathcal{K}_i)\to B(\mathcal{H}_i)$, $i=1,2$,
we construct a new linear map $\phi:B(\mathcal{H})\to B(\mathcal{K})$, where
$\mathcal{K}=\mathcal{K}_1\oplus\mathcal{K}_2\oplus\mathbb{C}$,
$\mathcal{H}=\mathcal{H}_1\oplus\mathcal{H}_2\oplus\mathbb{C}$, by means of
some additional ingredients such as operators and functionals. We call it a
merging of maps $\phi_1$ and $\phi_2$. We discuss properties of this
construction. In particular, we provide conditions for positivity of $\phi$, as
well as for $2$-positivity, complete positivity and nondecomposability. In
particular, we show that for a pair composed of $2$-positive and $2$-copositive
maps, there is a nondecomposable merging of them. One of our main results
asserts, that for a canonical merging of a pair composed of completely positive
and completely copositive extremal maps, their canonical merging is an exposed
positive map. This result provides a wide class of new examples of exposed
positive maps. As an application, new examples of entangled PPT states are
described.


title: Nonequilibrium Kinetics of One-Dimensional Bose Gases

abstract:
  We study cold dilute gases made of bosonic atoms, showing that in the
mean-field one-dimensional regime they support stable out-of-equilibrium
states. Starting from the 3D Boltzmann-Vlasov equation with contact
interaction, we derive an effective 1D Landau-Vlasov equation under the
condition of a strong transverse harmonic confinement. We investigate the
existence of out-of-equilibrium states, obtaining stability criteria similar to
those of classical plasmas.


title: Solar Activity Studies using Microwave Imaging Observations

abstract:
  We report on the status of solar cycle 24 based on polar prominence eruptions
(PEs) and microwave brightness enhancement (MBE) information obtained by the
Nobeyama radioheliograph. The north polar region of the Sun had near-zero field
strength for more than three years (2012 to 2015) and ended only in September
2015 as indicated by the presence of polar PEs and the lack of MBE. The
zero-polar-field condition in the south started only around 2013, but it ended
by June 2014. Thus the asymmetry in the times of polarity reversal switched
between cycle 23 and 24. The polar MBE is a good proxy for the polar magnetic
field strength as indicated by the high degree of correlation between the two.
The cross-correlation between the high- and low-latitude MBEs is significant
for a lag of ~5.5 to 7.3 years, suggesting that the polar field of one cycle
indicates the sunspot number of the next cycle in agreement with the
Babcock-Leighton mechanism of solar cycles. The extended period of near-zero
field in the north-polar region should result in a weak and delayed sunspot
activity in the northern hemisphere in cycle 25.


title: On the roots of total domination polynomial of graphs

abstract:
  Let $G = (V, E)$ be a simple graph of order $n$. The total dominating set of
$G$ is a subset $D$ of $V$ that every vertex of $V$ is adjacent to some
vertices of $D$. The total domination number of $G$ is equal to minimum
cardinality of total dominating set in $G$ and denoted by $\gamma_t(G)$. The
total domination polynomial of $G$ is the polynomial
$D_t(G,x)=\sum_{i=\gamma_t(G)}^n d_t(G,i)$, where $d_t(G,i)$ is the number of
total dominating sets of $G$ of size $i$. In this paper, we study roots of
total domination polynomial of some graphs. We show that all roots of $D_t(G,
x)$ lie in the circle with center $(-1, 0)$ and the radius
$\sqrt[\delta]{2^n-1}$, where $\delta$ is the minimum degree of $G$. As a
consequence we prove that if $\delta\geq \frac{2n}{3}$, then every integer root
of $D_t(G, x)$ lies in the set $\{-3,-2,-1,0\}$.


title: On the Directivity of Low-Frequency Type IV Radio Bursts

abstract:
  An intense type IV radio burst was observed by the STEREO Behind (STB)
spacecraft located about 144 degres behind Earth. The burst was associated with
a large solar eruption that occurred on the backside of the Sun (N05E151) close
to the disk center in the STB view. The eruption was also observed by the
STEREO Ahead (STA) spacecraft (located at 149 degrees ahead of Earth) as an
eruption close to the west limb (N05W60) in that view. The type IV burst was
complete in STB observations in that the envelope reached the lowest frequency
and then receded to higher frequencies. The burst was partial viewed from STA,
revealing only the edge coming down to the lowest frequency. The type IV burst
was not observed at all near Earth because the source was 61 degrees behind the
east limb. The eruption was associated with a low-frequency type II burst
observed in all three views, although it was not very intense. Solar energetic
particles were also observed at both STEREOs and at SOHO, suggesting that the
shock was much extended, consistent with the very high speed of the CME (about
2048 km/s). These observations suggest that the type IV emission is directed
along a narrow cone above the flare site. We confirm this result statistically
using the type IV bursts of solar cycle 23.


title:
The I/O complexity of Strassen's matrix multiplication with
  recomputation

abstract:
  A tight $\Omega((n/\sqrt{M})^{\log_2 7}M)$ lower bound is derived on the \io
complexity of Strassen's algorithm to multiply two $n \times n$ matrices, in a
two-level storage hierarchy with $M$ words of fast memory. A proof technique is
introduced, which exploits the Grigoriev's flow of the matrix multiplication
function as well as some combinatorial properties of the Strassen computational
directed acyclic graph (CDAG). Applications to parallel computation are also
developed. The result generalizes a similar bound previously obtained under the
constraint of no-recomputation, that is, that intermediate results cannot be
computed more than once. For this restricted case, another lower bound
technique is presented, which leads to a simpler analysis of the \io complexity
of Strassen's algorithm and can be readily extended to other "Strassen-like"
algorithms.


title:
Metallicity Calibration and Photometric Parallax Estimation: I. UBV
  photometry

abstract:
  We present metallicity and photometric parallax calibrations for the F and G
type dwarfs with photometric, astrometric and spectroscopic data. The sample
consists of 168 dwarf stars covering the colour, iron abundance and absolute
magnitude intervals $0.30<(B-V)_0<0.68$ mag, $-2.0<[Fe/H]<0.4$ dex and
$3.4<M_V<6.0$ mag, respectively. The means and standard deviations of the
metallicity and absolute magnitude residuals are small, i.e.
$\langle\Delta[Fe/H]_{res}\rangle=0$ and $\sigma=0.134$ dex, and $\langle\Delta
(M_V)_{res}\rangle=0$ and $\sigma=0.174$ mag, respectively, which indicate
accurate metallicity and photometric parallax estimations.


abstract:
  We present Neural Autoregressive Distribution Estimation (NADE) models, which
are neural network architectures applied to the problem of unsupervised
distribution and density estimation. They leverage the probability product rule
and a weight sharing scheme inspired from restricted Boltzmann machines, to
yield an estimator that is both tractable and has good generalization
performance. We discuss how they achieve competitive performance in modeling
both binary and real-valued observations. We also present how deep NADE models
can be trained to be agnostic to the ordering of input dimensions used by the
autoregressive product rule decomposition. Finally, we also show how to exploit
the topological structure of pixels in images using a deep convolutional
architecture for NADE.


title:
An analysis of visitors' behavior in the Louvre Museum: A study using
  Bluetooth data

abstract:
  Museums often suffer from so-called "hyper-congestion", wherein the number of
visitors exceeds the capacity of the physical space of the museum. This can
potentially deteriorate the quality of visitor's experience disturbed by other
visitors' behaviors and presences. Although this situation can be mitigated by
managing visitors' flow between spaces, a detailed analysis of the visitor's
movement is required to fully realize and apply a proper solution to the
problem. This paper analyzes the visitor's sequential movements, the spatial
layout, and the relationship between them in large-scale art museums - Louvre
Museum - using anonymized data collected through noninvasive Bluetooth sensors.
This enables us to unveil some features of visitor's behavior and spatial
impact that shed some light on the mechanism of the museum overcrowding. The
analysis reveals that the visiting style of short and long stay visitors are
not as significantly different as one could expect. Both types of visitors tend
to visit a similar number of key locations in the museum while the longer stay
type visitors just tend to do so more extensively. In addition, we reveal that
some ways of exploring the museum appear frequently for both types of visitors,
although long stay type visitors might be expected to diversify much more given
the greater time spent in the museum. We suggest that these
similarities/dissimilarities make for an uneven distribution of the quantity of
visitors in the museum space. The findings increase the understanding of the
unknown behaviors of visitors, which is key to improve the museum's environment
and visiting experience.


title: On the Frattini subgroup of a finite group

abstract:
  We study the class of finite groups $G$ satisfying $\Phi (G/N)= \Phi(G)N/N$
for all normal subgroups $N$ of $G$. As a consequence of our main results we
extend and amplify a theorem of Doerk concerning this class from the soluble
universe to all finite groups and answer in the affirmative a long-standing
question of Christensen whether the class of finite groups which possess
complements for each of their normal subgroups is subnormally closed.


title: Ultrametric spaces of branches on arborescent singularities

abstract:
  Let $S$ be a normal complex analytic surface singularity. We say that $S$ is
arborescent if the dual graph of any resolution of it is a tree. Whenever $A,B$
are distinct branches on $S$, we denote by $A \cdot B$ their intersection
number in the sense of Mumford. If $L$ is a fixed branch, we define $U_L(A,B)=
(L \cdot A)(L \cdot B)(A \cdot B)^{-1}$ when $A \neq B$ and $U_L(A,A) =0$
otherwise. We generalize a theorem of P{\l}oski concerning smooth germs of
surfaces, by proving that whenever $S$ is arborescent, then $U_L$ is an
ultrametric on the set of branches of $S$ different from $L$. We compute the
maximum of $U_L$, which gives an analog of a theorem of Teissier. We show that
$U_L$ encodes topological information about the structure of the embedded
resolutions of any finite set of branches. This generalizes a theorem of Favre
and Jonsson concerning the case when both $S$ and $L$ are smooth. We generalize
also from smooth germs to arbitrary arborescent ones their valuative
interpretation of the dual trees of the resolutions of $S$. Our proofs are
based in an essential way on a determinantal identity of Eisenbud and Neumann.


title:
Opportunistic Spectrum Sharing in Dynamic Access Networks: Deployment
  Challenges, Optimizations, Solutions, and Open Issues

abstract:
  In this paper, we investigate the issue of spectrum assignment in CRNs and
examine various opportunistic spectrum access approaches proposed in the
literature. We provide insight into the efficiency of such approaches and their
ability to attain their design objectives. We discuss the factors that impact
the selection of the appropriate operating channel(s), including the important
interaction between the cognitive linkquality conditions and the time-varying
nature of PRNs. Protocols that consider such interaction are described. We
argue that using best quality channels does not achieve the maximum possible
throughput in CRNs (does not provide the best spectrum utilization). The impact
of guard bands on the design of opportunistic spectrum access protocols is also
investigated. Various complementary techniques and optimization methods are
underlined and discussed, including the utilization of variablewidth spectrum
assignment, resource virtualization, full-duplex capability, cross-layer
design, beamforming and MIMO technology, cooperative communication, network
coding, discontinuousOFDM technology, and software defined radios. Finally, we
highlight several directions for future research in this field.


title:
Exploratory graph analysis: a new approach for estimating the number of
  dimensions in psychological research

abstract:
  The estimation of the correct number of dimensions is a long-standing problem
in psychometrics. Several methods have been proposed, such as parallel analysis
(PA), Kaiser-Guttman's eigenvalue-greaterthan-one rule, multiple average
partial procedure (MAP), the maximum-likelihood approaches that use fit indexes
as BIC and EBIC and the less used and studied approach called very simple
structure (VSS). In the present paper a new approach to estimate the number of
dimensions will be introduced and compared via simulation to the traditional
techniques pointed above. The approach proposed in the current paper is called
exploratory graph analysis (EGA), since it is based on the graphical lasso with
the regularization parameter specified using EBIC. The number of dimensions is
verified using the walktrap, a random walk algorithm used to identify
communities in networks. In total, 32,000 data sets were simulated to fit known
factor structures, with the data sets varying across different criteria: number
of factors (2 and 4), number of items (5 and 10), sample size (100, 500, 1000
and 5000) and correlation between factors (orthogonal, .20, .50 and .70),
resulting in 64 different conditions. For each condition, 500 data sets were
simulated using lavaan. The result shows that the EGA performs comparable to
parallel analysis, EBIC, eBIC and to KaiserGuttman rule in a number of
situations, especially when the number of factors was two. However, EGA was the
only technique able to correctly estimate the number of dimensions in the
four-factor structure when the correlation between factors were .7, showing an
accuracy of 100% for a sample size of 5,000 observations. Finally, the EGA was
used to estimate the number of factors in a real dataset, in order to compare
its performance with the other six techniques tested in the simulation study.


title: Thinking Inside and Outside the Box

abstract:
  I discuss puzzles that require thinking outside the box. I also discuss the
box inside of which many people think.


title:
On the Capacity of the Beta-Binomial Channel Model for Multi-Level Cell
  Flash Memories

abstract:
  The beta-binomial (BBM) channel model was recently proposed to model the
overdispersed statistics of empirically observed bit errors in multi-level cell
(MLC) flash memories. In this paper, we study the capacity of the BBM channel
model for MLC flash memories. Using the compound channel approach, we first
show that the BBM channel model capacity is zero. However, through empirical
observation, this appears to be a very pessimistic estimate of the flash memory
channel capacity. We propose a refined channel model called the
truncated-support beta-binomial (TS-BBM) channel model and derive its capacity.
Using empirical error statistics from 1X-nm and 2Y-nm MLC flash memories, we
numerically estimate the TS-BBM channel model capacity as a function of the
program/erase (P/E) cycling stress. The capacity of the 2-TS-BBM channel model
provides an upper bound on the coding rates for the flash memory chip assuming
a single binary error correction code is used.


title: A Bayesian Group Sparse Multi-Task Regression Model for Imaging Genetics

abstract:
  Motivation: Recent advances in technology for brain imaging and
high-throughput genotyping have motivated studies examining the influence of
genetic variation on brain structure. Wang et al. (Bioinformatics, 2012) have
developed an approach for the analysis of imaging genomic studies using
penalized multi-task regression with regularization based on a novel group
$l_{2,1}$-norm penalty which encourages structured sparsity at both the gene
level and SNP level. While incorporating a number of useful features, the
proposed method only furnishes a point estimate of the regression coefficients;
techniques for conducting statistical inference are not provided. A new
Bayesian method is proposed here to overcome this limitation.
  Results: We develop a Bayesian hierarchical modeling formulation where the
posterior mode corresponds to the estimator proposed by Wang et al.
(Bioinformatics, 2012), and an approach that allows for full posterior
inference including the construction of interval estimates for the regression
parameters. We show that the proposed hierarchical model can be expressed as a
three-level Gaussian scale mixture and this representation facilitates the use
of a Gibbs sampling algorithm for posterior simulation. Simulation studies
demonstrate that the interval estimates obtained using our approach achieve
adequate coverage probabilities that outperform those obtained from the
nonparametric bootstrap. Our proposed methodology is applied to the analysis of
neuroimaging and genetic data collected as part of the Alzheimer's Disease
Neuroimaging Initiative (ADNI), and this analysis of the ADNI cohort
demonstrates clearly the value added of incorporating interval estimation
beyond only point estimation when relating SNPs to brain imaging
endophenotypes.


title: Construction of right inverses of the Kirwan map

abstract:
  Biinvariant diagonal classes give rise to right inverses of the Kirwan map.
By means of multivalued perturbations of the gradient flow equation such
classes are constructed explicitly for $S^1$-Hamiltonian spaces. Moreover, the
notion of biinvariant diagonal class is extended to a cohomology map that gives
extra topological information on the Hamiltonian space. The non-uniqueness of
global biinvariant diagonal classes is also proven.


title: Higgs Starobinsky Inflation

abstract:
  In this paper we point out that Starobinky inflation could be induced by
quantum effects due to a large non-minimal coupling of the Higgs boson to the
Ricci scalar. The Higgs Starobinsky mechanism provides a solution to issues
attached to large Higgs field values in the early universe which in a
metastable universe would not be a viable option. We verify explicitly that
these large quantum corrections do not destabilize Starobinsky's potential.


title:
A note on the Mann iteration for $k$-strict pseudocontractions in Banach
  spaces

abstract:
  We show that a variant of a function defined by Cholamjiak and Suantai can be
used to characterize 2-uniform smoothness. We then obtain greatly simplified
proofs of a convergence theorem of Marino and Xu and of one of Zhou using a
generalization of a lemma of Browder and Petryshyn and the aforementioned
characterization. We also obtain more easily rates of asymptotic regularity
corresponding to the studied iterations. Finally, we derive a way to relate two
constants which are characteristic to 2-uniformly smooth spaces.


title:
Latency Analysis of Systems with Multiple Interfaces for Ultra-Reliable
  M2M Communication

abstract:
  One of the ways to satisfy the requirements of ultra-reliable low latency
communication for mission critical Machine-type Communications (MTC)
applications is to integrate multiple communication interfaces. In order to
estimate the performance in terms of latency and reliability of such an
integrated communication system, we propose an analysis framework that combines
traditional reliability models with technology-specific latency probability
distributions. In our proposed model we demonstrate how failure correlation
between technologies can be taken into account. We show for the considered
scenario with fiber and different cellular technologies how up to 5-nines
reliability can be achieved and how packet splitting can be used to reduce
latency substantially while keeping 4-nines reliability. The model has been
validated through simulation.


title: Nesting statistics in the $O(n)$ loop model on random planar maps

abstract:
  In the $O(n)$ loop model on random planar maps, we study the depth -- in
terms of the number of levels of nesting -- of the loop configuration, by means
of analytic combinatorics. We focus on the `refined' generating series of
pointed disks or cylinders, which keep track of the number of loops separating
the marked point from the boundary (for disks), or the two boundaries (for
cylinders). For the general $O(n)$ loop model, we show that these generating
series satisfy functional relations obtained by a modification of those
satisfied by the unrefined generating series. In a more specific $O(n)$ model
where loops cross only triangles and have a bending energy, we explicitly
compute the refined generating series. We analyze their non generic critical
behavior in the dense and dilute phases, and obtain the large deviations
function of the nesting distribution, which is expected to be universal. Using
the framework of Liouville quantum gravity (LQG), we show that a rigorous
functional KPZ relation can be applied to the multifractal spectrum of extreme
nesting in the conformal loop ensemble (${\rm CLE}_{\kappa}$) in the Euclidean
unit disk, as obtained by Miller, Watson and Wilson, or to its natural
generalization to the Riemann sphere. It allows us to recover the large
deviations results obtained for the critical $O(n)$ random planar map models.
This offers, at the refined level of large deviations theory, a rigorous check
of the fundamental fact that the universal scaling limits of random planar map
models as weighted by partition functions of critical statistical models are
given by LQG random surfaces decorated by independent CLEs.


title:
On Image segmentation using Fractional Gradients-Learning Model
  Parameters using Approximate Marginal Inference

abstract:
  Estimates of image gradients play a ubiquitous role in image segmentation and
classification problems since gradients directly relate to the boundaries or
the edges of a scene. This paper proposes an unified approach to gradient
estimation based on fractional calculus that is computationally cheap and
readily applicable to any existing algorithm that relies on image gradients. We
show experiments on edge detection and image segmentation on the Stanford
Backgrounds Dataset where these improved local gradients outperforms state of
the art, achieving a performance of 79.2% average accuracy.


title:
Asymptotically Safe gravity and non-singular inflationary Big Bang with
  vacuum birth

abstract:
  General non-singular accelerating cosmological solutions for an initial
cosmic period of pure vacuum birth era are derived. This vacuum era is
described by a varying cosmological "constant" suggested by the Renormalisation
Group flow of Asymptotic Safety scenario near the ultraviolet fixed point. In
this scenario, natural exit from inflation to the standard decelerating
cosmology occurs when the energy scale lowers and the cosmological "constant"
becomes insignificant. In the following period where matter is also present,
cosmological solutions with characteristics similar to the vacuum case are
generated. Remarkably the set of equations allow for particle production and
entropy generation. Alternatively, in the case of non-zero bulk viscosity,
entropy production and reheating is found. As for the equations of motion, they
modify Einstein equations by adding covariant kinetic terms of the cosmological
"constant" which respect the Bianchi identities. An advance of the proposed
framework is that it ensures a consistent description of both a quantum vacuum
birth of the universe and a subsequent cosmic era in the presence of matter.


title:
Perron-Frobenius theory and frequency convergence for reducible
  substitutions

abstract:
  We prove a general version of the classical Perron-Frobenius convergence
property for reducible matrices. We then apply this result to reducible
substitutions and use it to produce limit frequencies for factors and hence
invariant measures on the associated subshift. The analogous results are well
known for primitive substitutions and have found many applications, but for
reducible substitutions the tools provided here were so far missing from the
theory.


title: Magneto optical rotation in a GaAs Quantum Well Waveguide

abstract:
  The interaction of two orthogonally polarized beams and a four-level GaAs
quantum well (QW) waveguide is investigated. It is shown that, by applying a
static magnetic field normal to the propagation direction of the driving beams,
the birefringence can be induced in the QW waveguide. Moreover, it is
demonstrated that the dephasing rate between two ground states of the QW
waveguide makes it a dichromatic medium and can also diminish the induced
birefringence. Our results show how a large and complete magneto-optical
rotation in the QW waveguide can be obtained via adjusting the intensity of the
magnetic field and also the length of the QW waveguide.


title:
Electronic properties of the FeSe/STO interface from first-principle
  calculations

abstract:
  Compared to experiment, the calculated bulk lattice constant of FeSe is too
small in LDA, PBEsol and PBE type exchange-correlation (xc) functionals even
though the mismatch decreases from LDA to PBE. In bulk SrTiO3 (STO) on the
other hand LDA over-binds, PBE under-binds and PBEsol agrees best with
experiment. With the errors in opposite directions, the strain in the FeSe
monolayer on STO depends on the xc functional and, especially in the
non-magnetic state, is strongly overestimated. In this work we investigate the
influence of the xc functional and magnetism in density functional calculations
on electronic bonding properties and charge transfer in the FeSe monolayer on a
STO substrate. Furthermore, we consider the effect of oxygen-vacancies within
the virtual crystal approximation. In agreement with earlier work, we find that
the band structure of the checkerboard antiferromagnetic configuration agrees
best with experiment where, in addition, the relative strain on FeSe is best
described. For a small vacancy concentration, in agreement with recent
experiment, the FeSe monolayer Ti layer distance increases while for higher
concentrations it decreases.


title: Real-time collision detection method for deformable bodies

abstract:
  This paper presents a real-time solution for collision detection between
objects based on the physics properties. Traditional approaches on collision
detection often rely on the geometric relationships that computing the
intersections between polygons. Such technique is very computationally
expensive when applied for deformable objects. As an alternative, we
approximate the 3D mesh in an spherical surface implicitly. This allows us to
perform a coarse-level collision detection at extremely fast speed. Then a
dynamic programming based procedure is applied to identify the collision in
fine details. Our method demonstrates better prevention to collision tunnelling
and works more efficiently than the state-of-the-arts.