title:
Peaks over thresholds modelling with multivariate generalized Pareto
  distributions

abstract:
  When assessing the impact of extreme events, it is often not just a single
component, but the combined behaviour of several components which is important.
Statistical modelling using multivariate generalized Pareto (GP) distributions
constitutes the multivariate analogue of univariate peaks over thresholds
modelling, which is widely used in finance and engineering. We develop general
methods for construction of multivariate GP distributions and use them to
create a variety of new statistical models. A censored likelihood procedure is
proposed to make inference on these models, together with a threshold selection
procedure, goodness-of-fit diagnostics, and a computationally tractable
strategy for model selection. The models are fitted to returns of stock prices
of four UK-based banks and to rainfall data in the context of landslide risk
estimation. Supplementary materials and codes are available online.


title:
Exact solution for the inhomogeneous Dicke model in the canonical
  ensemble: thermodynamical limit and finite-size corrections

abstract:
  We consider an exactly solvable inhomogeneous Dicke model which describes an
interaction between a disordered ensemble of two-level systems with single mode
boson field. The existing method for evaluation of Richardson-Gaudin equations
in the thermodynamical limit is extended to the case of Bethe equations in
Dicke model. Using this extension, we present expressions both for the ground
state and lowest excited states energies as well as leading-order finite-size
corrections to these quantities for an arbitrary distribution of individual
spin energies. We then evaluate these quantities for an equally-spaced
distribution (constant density of states). In particular, we study evolution of
the spectral gap and other related quantities. We also reveal regions on the
phase diagram, where finite-size corrections are of particular importance.


title: Prospects for rare and forbidden hyperon decays at BESIII

abstract:
  The study of hyperon decays at the Beijing Electron Spectrometer III (BESIII)
is proposed to investigate the events of $J/\psi$ decay into hyperon pairs,
which provide a pristine experimental environment at the Beijing
Electron--Positron Collider II. About $10^{6}$--$10^8$ hyperons, i.e.,
$\Lambda$, $\Sigma$, $\Xi$, and $\Omega$, will be produced in the $J/\psi$ and
$\psi(2S)$ decays with the proposed data samples at BESIII. Based on these
samples, the measurement sensitivity of the branching fractions of the hyperon
decays is in the range of $10^{-5}$--$10^{-8}$. In addition, with the known
center-of-mass energy and "tag technique," rare decays and decays with
invisible final states can be probed.


title: On completions of Hecke algebras

abstract:
  Let G be a reductive p-adic group and let H(G)^s be a Bernstein block of the
Hecke algebra of G. We consider two important topological completions of
H(G)^s: a direct summand S(G)^s of the Harish-Chandra--Schwartz algebra of G
and a two-sided ideal C*_r (G)^s of the reduced C*-algebra of G. These are
useful for the study of all tempered smooth G-representations.
  We suppose that H(G)^s is Morita equivalent to an affine Hecke algebra H(R,q)
-- as is known in many cases. The latter algebra also has a Schwartz completion
S(R,q) and a C*-completion C*_r (R,q), both defined in terms of the underlying
root datum R and the parameters q.
  We prove that, under some mild conditions, a Morita equivalence between
H(G)^s and H(R,q) extends to Morita equivalences between S(G)^s and S(R,q), and
between C*_r (G)^s and C*_r (R,q). We also check that our conditions are
fulfilled in all known cases of such Morita equivalences between Hecke
algebras. This is applied to compute the topological K-theory of the reduced
C*-algebra of a classical p-adic group.


title: $\alpha_s$ in 2016 from the (revised) ALEPH data for $\tau$ decay

abstract:
  We summarize a comparison of the two strategies which are currently available
in the literature for determining the value of $\alpha_s(m_\tau)$. We will
refer to these as the truncated Operator Product Expansion model and the
Duality Violation model. After describing the main features of both approaches,
we explain why the former fails to pass crucial tests. The latter, on the other
hand, passes all the tests known up to date and, therefore, should be currently
considered the only reliable method.


title: Effect of grafting on the binding transition of two flexible polymers

abstract:
  We investigate the binding transition of two flexible polymers grafted to a
steric surface with closeby end points. While free polymers show a
discontinuous transition, grafting to a steric flat surface leads to a
continuous binding transition. This is supported by results from Metropolis and
parallel multicanonical simulations. A combination of canonical and
microcanonical analyses reveals that the change in transition order can be
understood in terms of the reduced translational entropy of the unbound
high-temperature phase upon grafting.


title: On Ikehara type Tauberian theorems with $O(x^\gamma)$ remainders

abstract:
  Motivated by analytic number theory, we explore remainder versions of
Ikehara's Tauberian theorem yielding power law remainder terms. More precisely,
for $f:[1,\infty)\rightarrow{\mathbb R}$ non-negative and non-decreasing we
prove $f(x)-x=O(x^\gamma)$ with $\gamma<1$ under certain assumptions on $f$. We
state a conjecture concerning the weakest natural assumptions and show that we
cannot hope for more.


title:
Particle-in-cell simulations of the relaxation of electron beams in
  inhomogeneous solar wind plasmas

abstract:
  Previous theoretical considerations of electron beam relaxation in
inhomogeneous plasmas have indicated that the effects of the irregular solar
wind may account for the poor agreement of homogeneous modelling with the
observations. Quasi-linear theory and Hamiltonian models based on Zakharov's
equations have indicated that when a level of density fluctuations is above a
given threshold, density irregularities act to de-resonate the beam-plasma
interaction, restricting Langmuir wave growth on the expense of beam energy.
This work presents the first fully kinetic particle-in-cell (PIC) simulations
of beam relaxation under the influence of density irregularities. We aim to
independently determine the influence of background inhomogeneity on the
beam-plasma system, and to test theoretical predictions and alternative models
using a fully kinetic treatment. We carry out 1D PIC simulations of a
bump-on-tail unstable electron beam in the presence of increasing levels of
background inhomogeneity using the fully electromagnetic, relativistic EPOCH
PIC code. We find that in the case of homogeneous background plasma density,
Langmuir wave packets are generated at the resonant condition and then
quasi-liear relaxation leads to a dynamic increase of wavenumbers generated. No
electron acceleration is seen - unlike in the inhomogeneous experiments, all of
which produce high-energy electrons. For the inhomogeneous experiments we also
observe the generation of backwards propagating Langmuir waves, which is shown
directly to be due to the refraction of the packets off the density gradients.
Our fully kinetic PIC simulations broadly confirm the findings of quasi-linear
theory and the Hamiltonian model based on Zakharov's equations. Strong density
fluctuations modify properties of excited Langmuir waves altering their
dispersion properties.


title: On the continuity of functionals defined on partitions

abstract:
  We characterize the continuity of prototypical functionals acting on finite
Caccioppoli partitions. In the spirit of the classical Reshetnyak continuity
theorem for measures that can be used to prove continuity of surface-type
functionals defined on single sets of finite perimeter we show that in the
multiphase case continuity is equivalent to convergence of the perimeter of the
jump set.


title:
Seasonal variation of radial brightness contrast of Saturn's rings
  viewed in mid-infrared by Subaru/COMICS

abstract:
  Aims. To investigate the mid-infrared (MIR) characteristics of Saturn's
rings. Methods. We collected and analyzed MIR high spatial resolution images of
Saturn's rings obtained in January 2008 and April 2005 with COMICS mounted on
Subaru Telescope, and investigated the spatial variation in the surface
brightness of the rings in multiple bands in the MIR. We also composed the
spectral energy distributions (SEDs) of the C, B, and A rings and the Cassini
Division, and estimated the temperatures of the rings from the SEDs assuming
the optical depths. Results. We find that the C ring and the Cassini Division
were warmer than the B and A rings in 2008, which could be accounted for by
their lower albedos, lower optical depths, and smaller self-shadowing effect.
We also find that the C ring and the Cassini Division were considerably
brighter than the B and A rings in the MIR in 2008 and the radial contrast of
the ring brightness is the inverse of that in 2005, which is interpreted as a
result of a seasonal effect with changing elevations of the sun and observer
above the ring plane.


title: A counterexample on spectra of zero patterns

abstract:
  An $n\times n$ zero pattern $S$, which is a matrix with entries $*$ and $0$,
is called spectrally arbitrary with respect to a field $F$ if any monic
polynomial $f$ of degree $n$ can be realized as the characteristic polynomial
of a matrix obtained from $S$ by replacing the $*$'s with non-zero elements of
$F$. We construct an $n\times n$ zero pattern that is spectrally arbitrary with
respect to $\mathbb{C}$ and has $2n-1$ nonzero entries.


title:
The Broken Lane of a Type II Radio Burst Caused by Collision of a
  Coronal Shock with a Flare Current Sheet

abstract:
  We investigated a peculiar metric type II solar radio burst with a broken
lane structure, which was observed on November 13, 2012. In addition to the
radio data, we also studied the data in the other wavelengths. The bursts were
associated with two CMEs and two flares that originated from active region AR
11613. A long current sheet was developed in the first CME, and the second CME
collided with the current sheet first and then merged with the first one.
Combing information revealed by the multi-wavelength data indicated that a
coronal shock accounting for the type II radio burst, and that the collision of
this shock with the current sheet resulted in the broken lane of the type II
radio burst. The type II burst lane resumed after the shock passed through the
current sheet. We further estimated the thickness of the current sheet
according to the gap on the lane of the type II burst, and found that the
result is consistent with previous ones obtained for various events observed in
different wavelengths by different instruments. In addition, the regular type
II burst associated with the first CME/flare was also studied, and the magnetic
field in each source region of the two type II bursts was further deduced in
different way.


title: Estimating Local Commuting Patterns From Geolocated Twitter Data

abstract:
  The emergence of large stores of transactional data generated by increasing
use of digital devices presents a huge opportunity for policymakers to improve
their knowledge of the local environment and thus make more informed and better
decisions. A research frontier is hence emerging which involves exploring the
type of measures that can be drawn from data stores such as mobile phone logs,
Internet searches and contributions to social media platforms, and the extent
to which these measures are accurate reflections of the wider population. This
paper contributes to this research frontier, by exploring the extent to which
local commuting patterns can be estimated from data drawn from Twitter. It
makes three contributions in particular. First, it shows that simple heuristics
drawn from geolocated Twitter data offer a good proxy for local commuting
patterns; one which outperforms the major existing method for estimating these
patterns (the radiation model). Second, it investigates sources of error in the
proxy measure, showing that the model performs better on short trips with
higher volumes of commuters; it also looks at demographic biases but finds
that, surprisingly, measurements are not significantly affected by the fact
that the demographic makeup of Twitter users differs significantly from the
population as a whole. Finally, it looks at potential ways of going beyond
simple heuristics by incorporating temporal information into models.


title:
Interpreting ALMA Observations of the ISM During the Epoch of
  Reionisation

abstract:
  We present cosmological, radiation-hydrodynamics simulations of galaxy
formation during the epoch of reionization in an effort towards modelling the
interstellar medium (ISM) and interpreting ALMA observations. Simulations with
and without stellar radiation are compared at large (Mpc), intermediate (tens
of kpc), and small (sub kpc) scales. At large scales, the dense regions around
galaxies reionize first before UV photons penetrate the voids; however,
considerable amounts of neutral gas remain present within the haloes. The
spatial distribution of neutral gas is highly dynamic and is anti-correlated
with the presence of stars older than a few Myrs. For our specific feedback
implementation, most of the metals remain inside the virial radii of haloes and
they are proportionally distributed over the ionized and neutral medium by
mass. For our most massive galaxy with ${\rm M_h}\sim10^{11}$M$_{\odot}$, the
majority of the CII and OI mass are associated with cold neutral clumps. NII is
more diffuse and arises in warmer gas while OIII arises in hotter gas with a
higher ionization parameter, produced by photo-heating and supernovae. If
smaller pockets of high metallicity gas exist in the ISM, the emission from
these ions may be observable by ALMA while the low metallicity of the galaxy
may cause these systems to fall below the local [CII]-SFR relation. The
presence of dust can cause spatial offsets between UV/Ly$\alpha$ and [CII]
emission as suggested by the recent observations of Maiolino et al. [OIII] may
be spatially offset from both of these components since it arises from a
different part of density-temperature phase-space.


title:
PRIMA: Privacy-Preserving Identity and Access Management at
  Internet-Scale

abstract:
  The management of identities on the Internet has evolved from the traditional
approach (where each service provider stores and manages identities) to a
federated identity management system (where the identity management is
delegated to a set of identity providers). On the one hand, federated identity
ensures usability and provides economic benefits to service providers. On the
other hand, it poses serious privacy threats to users as well as service
providers. The current technology, which is prevalently deployed on the
Internet, allows identity providers to track the user's behavior across a broad
range of services.
  In this work, we propose PRIMA, a universal credential-based authentication
system for supporting federated identity management in a privacy-preserving
manner. Basically, PRIMA does not require any interaction between service
providers and identity providers during the authentication process, thus
preventing identity providers to profile users' behavior. Moreover, throughout
the authentication process, PRIMA provides a mechanism for controlled
disclosure of the users' private information. We have conducted comprehensive
evaluations of the system to show the feasibility of our approach. Our
performance analysis shows that an identity provider can process 1,426 to 3,332
requests per second when the key size is varied from 1024 to 2048-bit,
respectively.


title:
Measurement of top quark pair differential cross-sections in the
  dilepton channel in $pp$ collisions at $\sqrt{s} =$ 7 and 8\,TeV with ATLAS

abstract:
  Measurements of normalized differential cross-sections of top quark pair
($t\bar t$) production are presented as a function of the mass, the transverse
momentum and the rapidity of the $t\bar t$ system in proton-proton collisions
at center-of-mass energies of $\sqrt{s}$ = 7 TeV and 8 TeV. The dataset
corresponds to an integrated luminosity of 4.6 fb$^{-1}$ at 7 TeV and 20.2
fb$^{-1}$ at 8 TeV, recorded with the ATLAS detector at the Large Hadron
Collider. Events with top quark pair signatures are selected in the dilepton
final state, requiring exactly two charged leptons and at least two jets with
at least one of the jets identified as likely to contain a $b$-hadron. The
measured distributions are corrected for detector effects and selection
efficiency to cross-sections at the parton level. The differential
cross-sections are compared with different Monte Carlo generators and
theoretical calculations of $t\bar t$ production. The results are consistent
with the majority of predictions in a wide kinematic range.


title:
Quantum gradient descent and Newton's method for constrained polynomial
  optimization

abstract:
  Optimization problems in disciplines such as machine learning are commonly
solved with iterative methods. Gradient descent algorithms find local minima by
moving along the direction of steepest descent while Newton's method takes into
account curvature information and thereby often improves convergence. Here, we
develop quantum versions of these iterative optimization algorithms and apply
them to polynomial optimization with a unit norm constraint. In each step,
multiple copies of the current candidate are used to improve the candidate
using quantum phase estimation, an adapted quantum principal component analysis
scheme, as well as quantum matrix multiplications and inversions. The required
operations perform polylogarithmically in the dimension of the solution vector
and exponentially in the number of iterations. Therefore, the quantum algorithm
can be beneficial for high-dimensional problems where a small number of
iterations is sufficient.


title: $SU(3)^p$ Quiver Theories with ${\cal N} = 0$ for $p=8$ and $9$

abstract:
  We close a gap in previous studies of nonsupersymmetric ${\cal N}=0$ quiver
gauge theories from a phenomenological point of view aimed at acquiring
specific proposals for models beyond the Standard Model (BSM). Because $SU(3)$
is the gauge group of QCD we fix $N=3$ and vary only the $Z_p$ abelian
orbifold. The values $1 \leq p \leq 7$ have been previously fully discussed as
well as one special case, discovered by happenstance, of $p=12$. The values $p
= 8$ and $p=9$ are discussed comprehensively in the present paper including the
electroweak mixing angle, gauge coupling unification, spontaneous symmetry
breakdown to the standard model, and the occurrence of three quark-lepton
families. Two promising quiver node identifications are discovered for $p=8$
and three for $p=9$. All of these merit further study as BSM candidates.


title:
Method for estimating cycle lengths from multidimensional time series:
  Test cases and application to a massive "in silico" dataset

abstract:
  Many real world systems exhibit cyclic behavior that is, for example, due to
the nearly harmonic oscillations being perturbed by the strong fluctuations
present in the regime of significant non-linearities. For the investigation of
such sys- tems special techniques relaxing the assumption to periodicity are
required. In this paper, we present the generalization of one of such
techniques, namely the D2 phase dispersion statistic, to multidimensional
datasets, especially suited for the analysis of the outputs from
three-dimensional numerical simulations of the full magnetohydrodynamic
equations. We present the motivation and need for the usage of such a method
with simple test cases, and present an application to a solar-like semi-global
numerical dynamo simulation covering nearly 150 magnetic cycles.


title: Scheme variations of the QCD coupling

abstract:
  The Quantum Chromodynamics (QCD) coupling $\alpha_s$ is a central parameter
in the Standard Model of particle physics. However, it depends on theoretical
conventions related to renormalisation and hence is not an observable quantity.
In order to capture this dependence in a transparent way, a novel definition of
the QCD coupling, denoted by $\hat a$, is introduced, whose running is
explicitly renormalisation scheme invariant. The remaining renormalisation
scheme dependence is related to transformations of the QCD scale $\Lambda$, and
can be parametrised by a single parameter $C$. Hence, we call $\hat a$ the
$C$-scheme coupling. The dependence on $C$ can be exploited to study and
improve perturbative predictions of physical observables. This is demonstrated
for the QCD Adler function and hadronic decays of the $\tau$ lepton.


title:
Generalised model-independent characterisation of strong gravitational
  lenses I: Theoretical foundations

abstract:
  We extend the model-independent approach to characterise strong gravitational
lenses of Wagner & Bartelmann (2016) to its most general form to leading order
by using the orientation angles of a set of multiple images with respect to
their connection line(s) in addition to the relative distances between the
images, their ellipticities and time-delays. For two symmetric images that
straddle the critical curve, the orientation angle additionally allows to
determine the slope of the critical curve and a second (reduced) flexion
coefficient at the critical point on the connection line between the images. It
also allows to drop the symmetry assumption that the axis of largest image
extension is orthogonal to the critical curve. For three images almost forming
a giant arc, the degree of assumed image symmetry is also reduced to the most
general case, allowing to describe image configurations for which the source
need not be placed on the symmetry axis of the two folds that unite at the
cusp. For a given set of multiple images, we set limits on the applicability of
our approach, show which information can be obtained in cases of merging
images, and analyse the accuracy achievable due to the Taylor expansion of the
lensing potential for the fold case on a galaxy cluster scale NFW-profile, a
fold and cusp case on a galaxy cluster scale SIE-profile, and compare the
generalised approach with the one of Wagner & Bartelmann (2016). The position
of the critical points is reconstructed with less than 5" deviation for
multiple images closer to the critical points than 30\% of the (effective)
Einstein radius and the slope of the critical curve at a fold and its shape in
the vicinity of a cusp deviate less than 20\% from the true values for
distances of the images to the critical points less than 15\% of the
(effective) Einstein radius.


title:
Characteristic Properties of Two Different Viscous Cosmology Models for
  the Future Universe

abstract:
  We analyze characteristic properties of two different cosmological models:
(i) a one-component dark energy model where the bulk viscosity $\zeta$ is
associated with the fluid as a whole, and (ii) a two-component model where
$\zeta$ is associated with a dark matter component $\rho_{\rm m}$ only, the
dark energy component considered inviscid. Shear viscosity is omitted. We
assume throughout the simple equation of state $p=w\rho$, with $w$ a constant.
In the one-component model we consider two possibilities, either to take
$\zeta$ proportional to the scalar expansion (equivalent to the Hubble
parameter), in which case the evolution becomes critically dependent on the
value of the small constant $\alpha=1+w$ and the magnitude of $\zeta$. Second,
we consider the case $\zeta=~$const., where a de Sitter final stage is reached
in the future. In the two-component model we consider only the case where the
dark matter viscosity $\zeta_{\rm m}$ is proportional to the square of
$\rho_{\rm m}$, where again a de Sitter form is found in the future. In this
latter case the formalism is supplemented by a phase space analysis. As a
general result of our considerations we suggest that a value $\zeta_0\sim
10^6~$Pa s for the present viscosity is reasonable, and that the two-component
model seems to be favored.


title:
Search for anomalous tq$\gamma$ FCNC Couplings in direct single top
  quark production at the LHC

abstract:
  In this paper we propose and study direct single top quark production channel
for probing the tq$\gamma$ flavor-changing neutral current (FCNC) interactions
at the LHC. We reinterpret the experimental results of a search for direct
single top quark production performed by ATLAS collaboration at 8 TeV to set
upper bounds on the FCNC top quark decay branching fractions through the
proposed channel, resulting in ${\cal B}$(t$\rightarrow$ u$\gamma$) $<$ 0.05\%
and ${\cal B}$(t$\rightarrow$ c$\gamma$) $<$ 0.14\%. Finally, the expected
sensitivity at 13 TeV for various integrated luminosity scenarios is estimated.


title: SQM2016: Theory Summary

abstract:
  This is an overview of the main theoretical developments presented at SQM2016
held in Berkeley, California (USA) in June 2015.


title:
Transversals in completely reducible multiary quasigroups and in
  multiary quasigroups of order 4

abstract:
  An $n$-ary quasigroup $f$ of order $q$ is an $n$-ary operation over a set of
cardinality $q$ such that the Cayley table of the operation is an
$n$-dimensional latin hypercube of order $q$. A transversal in a quasigroup $f$
(or in the corresponding latin hypercube) is a collection of $q$ $(n+1)$-tuples
from the Cayley table of $f$, each pair of tuples differing at each position.
The problem of transversals in latin hypercubes was posed by Wanless in 2011.
  An $n$-ary quasigroup $f$ is called reducible if it can be obtained as a
composition of two quasigroups whose arity is at least 2, and it is completely
reducible if it can be decomposed into binary quasigroups.
  In this paper we investigate transversals in reducible quasigroups and in
quasigroups of order 4. We find a lower bound on the number of transversals for
a vast class of completely reducible quasigroups. Next we prove that, except
for the iterated group $\mathbb{Z}_4$ of even arity, every $n$-ary quasigroup
of order 4 has a transversal. Also we obtain a lower bound on the number of
transversals in quasigroups of order 4 and odd arity and count transversals in
the iterated group $\mathbb{Z}_4$ of odd arity and in the iterated group
$\mathbb{Z}_2^2.$
  All results of this paper can be regarded as those concerning latin
hypercubes.


title: Discrete spectrum of interactions concentrated near conical surfaces

abstract:
  We study the spectrum of two kinds of operators involving a conical geometry:
the Dirichlet Laplacian in conical layers and Schr\"odinger operators with
attractive $\delta$-interactions supported by infinite cones. Under the
assumption that the cones have smooth cross-sections, we prove that such
operators have infinitely many eigenvalues accumulating below the threshold of
the essential spectrum and we express the accumulation rate in terms of the
eigenvalues of an auxiliary one-dimensional operator with a curvature-induced
potential.


title:
A GPU accelerated and error-controlled solver for the unbounded Poisson
  equation in three dimensions

abstract:
  An efficient solver for the three dimensional free-space Poisson equation is
presented. The underlying numerical method is based on finite Fourier series
approximation. While the error of all involved approximations can be fully
controlled, the overall computation error is driven by the convergence of the
finite Fourier series of the density. For smooth and fast-decaying densities
the proposed method will be spectral accurate. The method scales with
$\mathcal{O}(N\log N)$ operations, where $N$ is the total number of
discretization points in the Cartesian grid. The majority of the computational
costs come from fast Fourier transforms (FFT), which makes it ideal for GPU
computation. Several numerical computations on CPU and GPU validate the method
and show efficiency and convergence behavior. Tests are performed using the
Vienna Scientific Cluster 3 (VSC3). A free MATLAB implementation for CPU and
GPU is provided to the interested community.


title:
Pressure-induced magnetic transition exceeding 30 K in the Yb-based
  heavy fermion superconductor $\beta$-YbAlB$_4$

abstract:
  Measurements of the electric resistivity $\rho(T)$ under pressure up to 8 GPa
were performed on high-quality single-crystals of the Yb-based heavy fermion
system $\beta$-YbAlB$_4$ in the temperature range $2<T<$ 300 K. In the
resistivity data, we observed pressure-induced magnetic ordering above the
critical pressure $P_{\rm c} \sim$ 2 GPa. Clear difference in the phase diagram
under pressure using two types of pressure mediums indicates that the
transition temperature may be further enhanced under application of uniaxial
pressure. With pressure, this phase transition temperature $T_{\rm M}$ is
enhanced reaching 32 K at 8 GPa, which is the highest transition temperature so
far recorded for the Yb-based heavy fermion compounds. The power-law exponent
$\alpha$ in $\rho=\rho_0+ AT^{\alpha}$ below $T_{\rm M}$ gradually changes from
3/2 to 5/2 with increasing pressure from 2 to 8 GPa. In contrast, the
resistivity exhibits a $T$-linear behavior in the temperature range 2 $\le T
\le$ 20 K and is insensitive to pressure below $P_{\rm c}$. In this pressure
regime, the magnetization is also nearly independent of pressure and shows no
anomaly above 2 K. Our results indicate that a quantum critical point for
$\beta$-YbAlB$_4$ is also located near $P_{\rm c}$ in addition to the strange
metal region near the ambient pressure.


title:
Variable Selection with Scalable Bootstrap in Generalized Linear Model
  for Massive Data

abstract:
  Bootstrap is commonly used as a tool for non-parametric statistical inference
to estimate meaningful parameters in Variable Selection Models. However, for
massive dataset that has exponential growth rate, the computation of Bootstrap
Variable Selection (BootVS) can be a crucial issue. In this paper, we propose
the method of Variable Selection with Bag of Little Bootstraps (BLBVS) on
General Linear Regression and extend it to Generalized Linear Model for
selecting important parameters and assessing the quality of estimators'
computation efficiency by analyzing results of multiple bootstrap sub-samples.
The introduced method best suits large datasets which have parallel and
distributed computing structures. To test the performance of BLBVS, we compare
it with BootVS from different aspects via empirical studies. The results of
simulations show our method has excellent performance. A real data analysis,
Risk Forecast of Credit Cards, is also presented to illustrate the
computational superiority of BLBVS on large scale datasets, and the result
demonstrates the usefulness and validity of our proposed method.


title: Heralded Amplification of Path Entangled Quantum States

abstract:
  Device-independent quantum key distribution (DI-QKD) represents one of the
most fascinating challenges in quantum communication, exploiting concepts of
fundamental physics, namely Bell tests of nonlocality, to ensure the security
of a communication link. This requires the loophole-free violation of a Bell
inequality, which is intrinsically difficult due to losses in fibre optic
transmission channels. Heralded photon amplification is a teleportation-based
protocol that has been proposed as a means to overcome transmission loss for
DI-QKD. Here we demonstrate heralded photon amplification for path entangled
states and characterise the entanglement before and after loss by exploiting a
recently developed displacement-based detection scheme. We demonstrate that by
exploiting heralded photon amplification we are able to reliably maintain high
fidelity entangled states over loss-equivalent distances of more than 50~km.


title: Critical first-passage percolation starting on the boundary

abstract:
  We consider first-passage percolation on the two-dimensional triangular
lattice $\mathcal{T}$. Each site $v\in\mathcal{T}$ is assigned independently a
passage time of either $0$ or $1$ with probability $1/2$. Denote by $B^+(0,n)$
the upper half-disk with radius $n$ centered at $0$, and by $c_n^+$ the
first-passage time in $B^+(0,n)$ from $0$ to the half-circular boundary of
$B^+(0,n)$. We prove \[\lim_{n\rightarrow\infty}\frac{c_n^+}{\log
n}=\frac{\sqrt{3}}{2\pi}~ a.s.,~\lim_{n\rightarrow\infty}\frac{E c_n^+}{\log
n}=\frac{\sqrt{3}}{2\pi},~\lim_{n\rightarrow\infty}\frac{\mathrm{Var}(c_n^+)}{\log
n}=\frac{2\sqrt{3}}{\pi}-\frac{9}{\pi^2}.\] These results enable us to prove
limit theorems with explicit constants for any first-passage time between
boundary points of Jordan domains. In particular, we find the explicit limit
theorems for the cylinder point to point and cylinder point to line
first-passage times.


title:
Crystallization and vitrification of electrons in a glass-forming charge
  liquid

abstract:
  Charge ordering (CO) is a phenomenon in which electrons in solids crystallize
into a periodic pattern of charge-rich and charge-poor sites owing to strong
electron correlations. This usually results in long-range order. In
geometrically frustrated systems, however, a glassy electronic state without
long-range CO has been observed. We found that a charge-ordered organic
material with an isosceles triangular lattice shows charge dynamics associated
with crystallization and vitrification of electrons, which can be understood in
the context of an energy landscape arising from the degeneracy of various CO
patterns. The dynamics suggest that the same nucleation and growth processes
that characterize conventional glass-forming liquids guide the crystallization
of electrons. These similarities may provide insight into our understanding of
the liquid-glass transition.


title: Angular factor corrections in thin film x-ray diffraction

abstract:
  The current practice of angular (Lorentz, Polarization and absorption (LPA))
corrections in bulk materials for higher angle broad peaks, due to the
K{\alpha} doublet, are based on the results of Pike (Acta Cryst., 12 (1959)
87-92) and Ladell (Acta Cryst. 14 (1961) 47-53). These results are extended to
thin film x-ray diffraction. The current practice in thin film studies of using
the absorption factors for monochromatic radiation in LPA corrections is
incorrect in both symmetric and grazing incidence x-ray diffraction. The
correct expressions for absorption corrections are developed. In addition, a
new length scale, the linear regime, is shown to exist for very thin films
where the absorption factor and the integrated intensity are independent of the
absorption coefficient. For very thin films, it is practically advantageous to
use the expressions for the linear regime over those for the thin film regime.
The procedures to obtain both the main results are of general validity and can
be extended to several thin film diffraction techniques.


title: Ambitwistor superstring in the Green-Schwarz formulation

abstract:
  In this paper we construct the ambitwistor superstring in the Green-Schwarz
formulation. The model is obtained from the related pure spinor version. We
show that the spectrum contains only ten dimensional supergravity and that
kappa symmetry in a curved background implies some of the standard constraints.


title: Notes on semiclassical Weyl gravity

abstract:
  In any quantum theory of gravity, it is of the utmost importance to recover
the limit of quantum theory in an external spacetime. In quantum
geometrodynamics (quantization of general relativity in the Schr\"odinger
picture), this leads in particular to the recovery of a semiclassical (WKB)
time which governs the dynamics of non-gravitational fields in spacetime. Here,
we first review this procedure with special emphasis on conceptual issues. We
then turn to an alternative theory - Weyl (conformal) gravity, which is defined
by a Lagrangian that is proportional to the square of the Weyl tensor. We
present the canonical quantization of this theory and develop its semiclassical
approximation. We discuss in particular the extent to which a semiclassical
time can be recovered and contrast it with the situation in quantum
geometrodynamics.


title:
Probing CP-violating Higgs and gauge boson couplings in the Standard
  Model effective field theory

abstract:
  We study the phenomenological consequences of several $CP$-violating
structures that could arise in the Standard Model effective field theory
framework. Focusing on operators involving electroweak gauge and/or Higgs
bosons, we derive constraints originating from Run I LHC data. We then study
the capabilities of the present and future LHC runs at higher energies to
further probe associated CP-violating phenomena and we demonstrate how
differential information can play a key role. We consider both traditional
four-lepton probes of CP-violation in the Higgs sector and novel new physics
handles based on varied angular and non-angular observables.


title: Vibrational assisted conduction in a molecular wire

abstract:
  We present a detailed study of the conduction properties of a molecular wire
where hopping processes between electronic sites are coupled to a vibrational
mode of the molecule. The latter is sandwiched between two electronic leads at
finite temperatures. We show that the electro-mechanical coupling can lead to a
strong enhancement of the lead-to-lead conduction. Moreover, under suitable
driving of the molecular vibrational mode, the device can act as a transistor
passing sharply from enhanced conduction to short-circuit configuration.


title: FLIC: Fast Linear Iterative Clustering with Active Search

abstract:
  Benefiting from its high efficiency and simplicity, Simple Linear Iterative
Clustering (SLIC) remains one of the most popular over-segmentation tools.
However, due to explicit enforcement of spatial similarity for region
continuity, the boundary adaptation of SLIC is sub-optimal. It also has
drawbacks on convergence rate as a result of both the fixed search region and
separately doing the assignment step and the update step. In this paper, we
propose an alternative approach to fix the inherent limitations of SLIC. In our
approach, each pixel actively searches its corresponding segment under the help
of its neighboring pixels, which naturally enables region coherence without
being harmful to boundary adaptation. We also jointly perform the assignment
and update steps, allowing high convergence rate. Extensive evaluations on
Berkeley segmentation benchmark verify that our method outperforms competitive
methods under various evaluation metrics. It also has the lowest time cost
among existing methods (approximately 30fps for a 481x321 image on a single CPU
core).


title:
The Properties of the Magellanic Bridge Based on OGLE IV RR Lyrae
  Variables

abstract:
  We examine the properties of the Magellanic Bridge connecting the Large and
Small Magellanic Clouds using ab-type RR Lyrae variables from the extensive
dataset of the Optical Gravitational Lensing Experiment (OGLE), Phase IV data
release. The metallicities of the RR Lyraes are determined from the
characteristics of their light curves, with an average abundance of [Fe/H] =
-1.790 +/- 0.011 (sem) in the Magellanic Bridge. From the individual reddenings
of these stars, derived via their minimum light curve colors, we determined a
median color excess of E(V-I) = 0.101 +/- 0.007 (sem) (implying E(B-V)
$\approx$ 0.077). The peak distance modulus of 18.57 +/- 0.048 (sem) places the
Bridge stars at distances between the two systems. The metallicity and distance
distributions probe the structure of the Magellanic system as a whole,
revealing a smooth transition that connects the galaxies. An examination of the
HI content does not find a clear correlation between HI emission strength and
RR Lyrae spatial distribution, suggesting that the old stellar populations may
trace the overlapping halo distributions of the two Magellanic Clouds.


title: Control Matching via Discharge Code Sequences

abstract:
  In this paper, we consider the patient similarity matching problem over a
cancer cohort of more than 220,000 patients. Our approach first leverages on
Word2Vec framework to embed ICD codes into vector-valued representation. We
then propose a sequential algorithm for case-control matching on this
representation space of diagnosis codes. The novel practice of applying the
sequential matching on the vector representation lifted the matching accuracy
measured through multiple clinical outcomes. We reported the results on a
large-scale dataset to demonstrate the effectiveness of our method. For such a
large dataset where most clinical information has been codified, the new method
is particularly relevant.


title:
Rectifiability and upper Minkowski bounds for singularities of harmonic
  Q-valued maps

abstract:
  In this article we prove that the singular set of Dirichlet-minimizing
$Q$-valued functions is countably $(m-2)$-rectifiable and we give upper bounds
for the $(m-2)$-dimensional Minkowski content of the set of singular points
with multiplicity $Q$.


title: Symmetries in the wheeled inverted pendulum mechanism

abstract:
  The purpose of this article is to illustrate the role of connections and
symmetries in the Wheeled Inverted Pendulum (WIP) mechanism - an underactuated
system with rolling constraints - popularized commercially as the Segway, and
thereby arrive at a set of simpler dynamical equations that could serve as the
starting point for more complex feedback control designs. The first part of the
article views the nonholonomic constraints enforced by the rolling assumption
as defining an Ehresmann connection on a fiber bundle. The resulting equations
are the reduced Euler-Lagrange equations, which are identical to the Lagrange
d'Alembert equations of motion. In the second part we explore conserved
quantities, in particular, nonholonomic momenta. To do so, we first introduce
the notion of a symmetry group, whose action leaves both the Lagrangian and
distribution invariant. We examine two symmetry groups - $SE (2)$ and $SE(2)
\times \mathbb{S}^{1}$. The first group leads to the purely kinematic case
while the second gives rise to nonholonomic momentum equations.


title:
Atomic frequency reference at 1033 nm for ytterbium (Yb)-doped fiber
  lasers and applications exploiting a rubidium (Rb) 5$S_{1/2}$ to 4$D_{5/2}$
  one-colour two-photon transition

abstract:
  We demonstrate a two-photon transition of rubidium (Rb) atoms from the ground
state (5$S_{1/2}$) to the excited state (4$D_{5/2}$), using a home-built
ytterbium (Yb)-doped fiber amplifier at 1033 nm. This is the first
demonstration of an atomic frequency reference at 1033 nm as well as of a
one-colour two-photon transition for the above energy levels. A simple optical
setup is presented for the two-photon transition fluorescence spectroscopy,
which is useful for frequency stabilization for a broad class of lasers. This
spectroscopy has potential applications in the fiber laser industry as a
frequency reference, particularly for the Yb-doped fiber lasers. This
two-photon transition also has applications in atomic physics as a background-
free high- resolution atom detection and for quantum communication, which is
outlined in this article.


title:
A splitting algorithm for stochastic partial differential equations
  driven by linear multiplicative noise

abstract:
  We study the convergence of a Douglas-Rachford type splitting algorithm for
the infinite dimensional stochastic differential equation
$$dX+A(t)(X)dt=X\,dW\mbox{ in }(0,T);\ X(0)=x,$$ where $A(t):V\to V'$ is a
nonlinear, monotone, coercive and demicontinuous operator with sublinear growth
and $V$ is a real Hilbert space with the dual $V'$. $V$ is densely and
continuously embedded in the Hilbert space $H$ and $W$ is an $H$-valued Wiener
process. The general case of a maximal monotone operators $A(t):H\to H$ is also
investigated.


title: Pseudodeterministic Constructions in Subexponential Time

abstract:
  We study pseudodeterministic constructions, i.e., randomized algorithms which
output the same solution on most computation paths. We establish
unconditionally that there is an infinite sequence $\{p_n\}_{n \in \mathbb{N}}$
of increasing primes and a randomized algorithm $A$ running in expected
sub-exponential time such that for each $n$, on input $1^{|p_n|}$, $A$ outputs
$p_n$ with probability $1$. In other words, our result provides a
pseudodeterministic construction of primes in sub-exponential time which works
infinitely often.
  This result follows from a much more general theorem about
pseudodeterministic constructions. A property $Q \subseteq \{0,1\}^{*}$ is
$\gamma$-dense if for large enough $n$, $|Q \cap \{0,1\}^n| \geq \gamma 2^n$.
We show that for each $c > 0$ at least one of the following holds: (1) There is
a pseudodeterministic polynomial time construction of a family $\{H_n\}$ of
sets, $H_n \subseteq \{0,1\}^n$, such that for each $(1/n^c)$-dense property $Q
\in \mathsf{DTIME}(n^c)$ and every large enough $n$, $H_n \cap Q \neq
\emptyset$; or (2) There is a deterministic sub-exponential time construction
of a family $\{H'_n\}$ of sets, $H'_n \subseteq \{0,1\}^n$, such that for each
$(1/n^c)$-dense property $Q \in \mathsf{DTIME}(n^c)$ and for infinitely many
values of $n$, $H'_n \cap Q \neq \emptyset$.
  We provide further algorithmic applications that might be of independent
interest. Perhaps intriguingly, while our main results are unconditional, they
have a non-constructive element, arising from a sequence of applications of the
hardness versus randomness paradigm.


title:
An infinite family of cubic nonnormal Cayley graphs on nonabelian simple
  groups

abstract:
  We construct a connected cubic nonnormal Cayley graph on $\mathrm{A}_{2^m-1}$
for each integer $m\geqslant4$ and determine its full automorphism group. This
is the first infinite family of connected cubic nonnormal Cayley graphs on
nonabelian simple groups.


title: Measures and geometric probabilities for ellipses intersecting circles

abstract:
  Santal\'o calculated the measures for all positions of a moving line segment
in which it lies inside a fixed circle and intersects this circle in one or two
points. From these measures he concluded hitting probabilities for a line
segment thrown randomly onto an unbounded lattice of circles. In the present
paper these results are generalized to ellipses instead of line segments. The
respective measures for all positions of a moving ellipse in which it lies
completely inside a fixed circle, encloses it, and intersects it in two or four
points are derived. Then the hitting probabilities for lattices of circles are
deduced. It is shown that the results for a line segment follow as special
cases from those of the ellipse.


title:
Explaining Radiological Emphysema Subtypes with Unsupervised Texture
  Prototypes: MESA COPD Study

abstract:
  Pulmonary emphysema is traditionally subcategorized into three subtypes,
which have distinct radiological appearances on computed tomography (CT) and
can help with the diagnosis of chronic obstructive pulmonary disease (COPD).
Automated texture-based quantification of emphysema subtypes has been
successfully implemented via supervised learning of these three emphysema
subtypes. In this work, we demonstrate that unsupervised learning on a large
heterogeneous database of CT scans can generate texture prototypes that are
visually homogeneous and distinct, reproducible across subjects, and capable of
predicting accurately the three standard radiological subtypes. These texture
prototypes enable automated labeling of lung volumes, and open the way to new
interpretations of lung CT scans with finer subtyping of emphysema.


title: Principal fiber bundles in non-commutative geometry

abstract:
  These are the expanded notes of a course given at the Summer school
"Geometric, topological and algebraic methods for quantum field theory" held at
Villa de Leyva, Colombia in July 2015. We first give an introduction to
non-commutative geometry and to the language of Hopf algebras. We next build up
a theory of non-commutative principal fiber bundles and consider various
aspects of such objects. Finally, we illustrate the theory using the quantum
enveloping algebra $U_q\mathfrak{sl}(2)$ and related Hopf algebras.


title:
How many scientific papers are mentioned in policy-related documents? An
  empirical investigation using Web of Science and Altmetric data

abstract:
  In this short communication, we provide an overview of a relatively newly
provided source of altmetrics data which could possibly be used for societal
impact measurements in scientometrics. Recently, Altmetric - a start-up
providing publication level metrics - started to make data for publications
available which have been mentioned in policy-related documents. Using data
from Altmetric, we study how many papers indexed in the Web of Science (WoS)
are mentioned in policy-related documents. We find that less than 0.5% of the
papers published in different subject categories are mentioned at least once in
policy-related documents. Based on our results, we recommend that the analysis
of (WoS) publications with at least one policy-related mention is repeated
regularly (annually). Mentions in policy-related documents should not be used
for impact measurement until new policy-related sites are tracked.


title: Experimental limits on the free parameters of higher-derivative gravity

abstract:
  Fourth-derivative gravity has two free parameters, $\alpha$ and $\beta$,
which couple the curvature-squared terms $R^2$ and $R_{\mu\nu}^2$. Relativistic
effects and short-range laboratory experiments can be used to provide upper
limits to these constants. In this work we briefly review both types of
experimental results in the context of higher-derivative gravity. The strictest
limit follows from the second kind of test. Interestingly enough, the bound on
$\beta$ due to semiclassical light deflection at the solar limb is only one
order of magnitude larger.


title: Revisiting the cuscuton as a Lorentz-violating gravity theory

abstract:
  The cuscuton is a scalar field with infinite speed of propagation. It was
introduced in the context of cosmology but it has also been claimed to resemble
Horava gravity in a certain limit. Here we revisit the cuscuton theory as a
Lorentz-violating gravity theory. We clarify its relation with Horava gravity
and Einstein-aether theory, analyze its causal structure, and consider its
initial value formulation. Finally, we discuss to which extent the cuscuton
theory can be used as a proxy for Horava gravity in the context of
gravitational collapse and formation of universal horizons.


title:
The VIMOS Public Extragalactic Redshift Survey (VIPERS): PCA-based
  automatic cleaning and reconstruction of survey spectra

abstract:
  Identifying spurious reduction artefacts in galaxy spectra is a challenge for
large surveys. We present an algorithm for identifying and repairing residual
spurious features in sky-subtracted galaxy spectra with application to the
VIPERS survey. The algorithm uses principal component analysis (PCA) applied to
the galaxy spectra in the observed frame to identify sky line residuals
imprinted at characteristic wavelengths. We further model the galaxy spectra in
the rest-frame using PCA to estimate the most probable continuum in the
corrupted spectral regions, which are then repaired. We apply the method to
90,000 spectra from the VIPERS survey and compare the results with a subset
where careful editing was performed by hand. We find that the automatic
technique does an extremely good job in reproducing the time-consuming manual
cleaning and does it in a uniform and objective manner across a large data
sample. The mask data products produced in this work are released together with
the VIPERS second public data release (PDR-2).


title: Superradiance in the sky

abstract:
  We discuss the conditions under which plane electromagnetic and gravitational
waves can be amplified by a rotating black hole due to superradiant scattering.
We show, in particular, that amplification can occur for low-frequency waves
with an incidence angle parametrically close to 0 (or $\pi$) with respect to
the black hole spin axis and with a parametrically small left (or right)
polarization. This is the case of the radiation emitted by a spinning
electric/magnetic dipole or gravitational quadrupole orbiting a black hole
companion at large radius and co-rotating with the latter. This can yield
observable effects of superradiance, for example, in neutron star-stellar mass
black hole binaries, as well as in triple systems composed by a compact binary
orbiting a central supermassive black hole. Due to superradiance, the total
source luminosity in these systems exhibits a characteristic orbital modulation
that may lead to significant observational signatures, thus paving the way for
testing, in the near future, one of the most peculiar predictions of general
relativity.


title: Construction of Neron Desingularization for Two Dimensional Rings

abstract:
  An algorithmic proof of the General Neron Desingularization theorem is given
for $2$-dimensional local rings and morphisms with small singular locus.


title: On a Mirror Structure of Matter Fields

abstract:
  Spontaneous mirror symmetry violation is carried out in nature as the
transition between the usual left (right)-handed and the mirror right
(left)-handed spaces, where the same particle has the different lifetimes. As a
consequence, all the equations of motion for the unified field theory of
elementary particles include the mass, energy and momentum as the matrices
expressing the ideas of the left- and right-handed neutrinos are of long- and
short-lived objects, respectively. These ideas require in principle to go away
from the chiral definitions of the structure of matter fields taking into
account that the Dirac matrices come forward in the Weyl presentation as the
matrices having an exact mathematical formulation but not allowing to follow
the logic of a true nature of mirror symmetry including the dynamical
origination of its spontaneous violation. Therefore, from the point of view of
the mass, energy and momentum matrices, each of the structural contradictions
between the spontaneous mirror symmetry violation and the chiral presentation
of the Weyl must be interpreted as an indication to the absence in nature of a
place for chirality.


title: Symmetry exploitation for Online Machine Covering with Bounded Migration

abstract:
  Online models that allow recourse are highly effective in situations where
classical models are too pessimistic. One such problem is the online machine
covering problem on identical machines. In this setting, jobs arrive one by one
and must be assigned to machines with the objective of maximizing the minimum
machine load. When a job arrives, we are allowed to reassign some jobs as long
as their total size is (at most) proportional to the processing time of the
arriving job. The proportionality constant is called the migration factor of
the algorithm. Using a rounding procedure with useful structural properties for
online packing and covering problems, we design first a simple $(1.7 +
\varepsilon)$-competitive algorithm using a migration factor of
$O(1/\varepsilon)$ which maintains at every arrival a locally optimal solution
with respect to the Jump neighborhood. After that, we present as our main
contribution a more involved $(4/3+\varepsilon)$-competitive algorithm using a
migration factor of $\tilde{O}(1/\varepsilon^3)$. At every arrival, we run an
adaptation of the Largest Processing Time first (LPT) algorithm. Since the new
job can cause a complete change of the assignment of smaller jobs in both
cases, a low migration factor is achieved by carefully exploiting the highly
symmetric structure obtained by the rounding procedure.


title: Strings in Background Fields

abstract:
  In this paper free quantum theories are derived solely from their underlying
symmetry group without reference to a Lagrangean or classical physics and then
interactions are introduced by making use of automorphism of the symmetry
algebra. It is shown how the solution of a theory interacting with background
fields is obtained exactly and purely algebraically from the free theory by the
action of a linear operator. The method is first applied to the harmonic
oscillator interacting with a conserved current and in a second example to
string theory in the presence of constant dilaton, Kalb-Ramond or gravitational
fields. The derived interaction for the Kalb-Ramond background is periodic and
the interactions with a dilaton respectively a gravitational field exhibit a
strong-weak-coupling duality. Furthermore, it is proposed in this paper to
interpret T-duality as a position-momentum duality on compact space.


title: A simulation of hydrodynamics on non-commutative space

abstract:
  A simulation of the hydrodynamics on the two dimensional non-commutative
space is performed, in which the space coordinates $(x, y)$ are
non-commutative, satisfying the commutation relation $[x, y]=i \theta$. The
Navier-Stokes equation has an extra force term which reflects the
non-commutativity of the space, being proportional to $\theta^2$. This
parameter $\theta$ is related to the minimum size of fluid particles which is
implied by the uncertainty principle, $\Delta x \Delta y \ge \theta/2$. To see
the effect of this parameter on the flow, following situation is considered. An
obstacle placed in the middle of the stream, separates the flow into small slit
and large slit, but the flow is joined afterwards in the down stream. For the
Reynolds number 700, the behavior of the flows with and without $\theta$ is
observed to differ, and the difference is seen to be correlated to the
difference of the activity of vortices in the down stream. The oscillation of
the flow rate at the small slit diminishes after the certain time in the usual
flow when the "two attached eddies" appear. In the non-commutative flow this
two attached eddies appear from the beginning and the behavior of the flows
does not fluctuate largely. The irregularity in the flow existing in the
beginning disappears after the certain time.


title:
The Planck length and the constancy of the speed of light in five
  dimensional space parametrized with two time coordinates

abstract:
  In relativity and quantum field theory, the vacuum speed of light is assumed
to be constant; the range of validity of general relativity is determined by
the Planck length. However, there has been no convincing theory explaining the
constancy of the light speed. In this paper, we assume a five dimensional
spacetime with three spatial dimensions and two local time coordinates giving
us a hint about the constancy of the speed of light. By decomposing the five
dimensional spacetime vector into four-dimensional vectors for each time
dimension and by minimizing the resulting action, for a certain class of
additional time dimensions, we observe the existence of a minimal length scale,
which we identify as the Planck scale. We derive an expression for the speed of
light as a function of space and time and observe the constancy of the vacuum
speed of light in the observable universe.


title: Dirichlet heat kernel for the Laplacian in a ball

abstract:
  We provide sharp two-sided estimates on the Dirichlet heat kernel
$k_1(t,x,y)$ for the Laplacian in a ball. The result accurately describes the
exponential behaviour of the kernel for small times and significantly improves
the qualitatively sharp results known so far. As a consequence we obtain the
full description of the kernel $k_1(t,x,y)$ in terms of its global two-sided
sharp estimates.


title: Revisiting Winner Take All (WTA) Hashing for Sparse Datasets

abstract:
  WTA (Winner Take All) hashing has been successfully applied in many large
scale vision applications. This hashing scheme was tailored to take advantage
of the comparative reasoning (or order based information), which showed
significant accuracy improvements. In this paper, we identify a subtle issue
with WTA, which grows with the sparsity of the datasets. This issue limits the
discriminative power of WTA. We then propose a solution for this problem based
on the idea of Densification which provably fixes the issue. Our experiments
show that Densified WTA Hashing outperforms Vanilla WTA both in image
classification and retrieval tasks consistently and significantly.


title: Sub-Linear Privacy-Preserving Near-Neighbor Search

abstract:
  In Near-Neighbor Search (NNS), a new client queries a database (held by a
server) for the most similar data (near-neighbors) given a certain similarity
metric. The Privacy-Preserving variant (PP-NNS) requires that neither server
nor the client shall learn information about the other party's data except what
can be inferred from the outcome of NNS. The overwhelming growth in the size of
current datasets and the lack of a truly secure server in the online world
render the existing solutions impractical; either due to their high
computational requirements or non-realistic assumptions which potentially
compromise privacy. PP-NNS having query time {\it sub-linear} in the size of
the database has been suggested as an open research direction by Li et al.
(CCSW'15). In this paper, we provide the first such algorithm, called Secure
Locality Sensitive Indexing (SLSI) which has a sub-linear query time and the
ability to handle honest-but-curious parties. At the heart of our proposal lies
a secure binary embedding scheme generated from a novel probabilistic
transformation over locality sensitive hashing family. We provide information
theoretic bound for the privacy guarantees and support our theoretical claims
using substantial empirical evidence on real-world datasets.


title: Diamond Configuration for Non-reciprocal Transmission

abstract:
  A system scheme is presented which allows non-reciprocal wave transmission or
directional amplification of electromagnetic signals, using a boxed four-node
method. Edges represent strong hopping interactions and diagonals stand for
weak parametric interactions. Using careful optimization of values for design
parameters, we are able to obtain non-reciprocity in excess of 12dB and 130dB
for intrinsic and extrinsic configurations at identical input/output
frequencies. For the directional amplification, an isolation as high as 40dB is
demonstrated with forward/backward gains of $\pm$20dB. Cascading two such
systems potentially can offer high isolations at high gains.


title:
Design and ARM-embedded implementation of a chaotic map-based multicast
  scheme for multiuser speech wireless communication

abstract:
  This paper proposes a chaotic map-based multicast scheme for multiuser speech
wireless communication and implements it in an ARM platform. The scheme
compresses the digital audio signal decoded by a sound card and then encrypts
it with a three-level chaotic encryption scheme. First, the position of every
bit of the compressed data is permuted randomly with a pseudo-random number
sequence (PRNS) generated by a 6-D chaotic map. Then, the obtained data are
further permuted in the level of byte with a PRNS generated by a 7-D chaotic
map. Finally, it is operated with a multiround chaotic stream cipher. The whole
system owns the following merits: the redundancy in the original audio file is
reduced effectively and the corresponding unicity distance is increased; the
balancing point between a high security level of the system and real-time
conduction speed is achieved well. In the ARM implementation, the framework of
communication of multicast-multiuser in a subnet and the Internet Group Manage
Protocol is adopted to obtain the function of communication between one client
and other ones. Comprehensive test results were provided to show the
feasibility and security performance of the whole system.


title: Ultrafast Dynamics of the Charge Density Wave State in Layered CuxTiSe2

abstract:
  We report on a transient optical reflectivity study of the charge density
wave (CDW) in CuxTiSe2 single crystals. Our measurements reveal that the system
undergoes a quantum phase transition at x=0.04 from a strong commensurate CDW
(x<0.04) to a soft incommensurate CDW (x>0.04). We find that the cooperative
driving mechanisms for the commensurate CDW, the excitonic insulator mechanism
and the soft L$_1$$^-$ phonon mode, decouple at x=0.04 with the observed
fluctuations in the folded Se-4p band dominating the transition. We also
demonstrate a loss of coherence in the A$_{1g}$ phonon with increased copper
intercalation of the parent lattice, indicating a loss of long-range lattice
order. These findings provide compelling evidence that TiSe2 undergoes a
quantum phase transition upon copper intercalation from a state of commensurate
charge order to a state with a different symmetry in which the new charge order
coexists with the superconducting phase.


title: A random wave model for the Aharonov-Bohm effect

abstract:
  We study an ensemble of random waves subject to the Aharonov-Bohm effect. The
introduction of a point with a magnetic flux of arbitrary strength into a
random wave ensemble gives a family of wavefunctions whose distribution of
vortices (complex zeros) are responsible for the topological phase associated
with the Aharonov-Bohm effect. Analytical expressions are found for the vortex
number and topological charge densities as functions of distance from the flux
point. Comparison is made with the distribution of vortices in the isotropic
random wave model. The results indicate that as the flux approaches
half-integer values, a vortex with the same sign as the fractional part of the
flux is attracted to the flux point, merging with it at half-integer flux.
Other features of the Aharonov-Bohm vortex distribution are also explored.


title: FMA: A Dataset For Music Analysis

abstract:
  We introduce the Free Music Archive (FMA), an open and easily accessible
dataset suitable for evaluating several tasks in MIR, a field concerned with
browsing, searching, and organizing large music collections. The community's
growing interest in feature and end-to-end learning is however restrained by
the limited availability of large audio datasets. The FMA aims to overcome this
hurdle by providing 917 GiB and 343 days of Creative Commons-licensed audio
from 106,574 tracks from 16,341 artists and 14,854 albums, arranged in a
hierarchical taxonomy of 161 genres. It provides full-length and high-quality
audio, pre-computed features, together with track- and user-level metadata,
tags, and free-form text such as biographies. We here describe the dataset and
how it was created, propose a train/validation/test split and three subsets,
discuss some suitable MIR tasks, and evaluate some baselines for genre
recognition. Code, data, and usage examples are available at
https://github.com/mdeff/fma


title: Harmonic analysis for real spherical spaces

abstract:
  We give an introduction to basic harmonic analysis and representation theory
for homogeneous spaces $Z=G/H$ attached to a real reductive Lie group $G$. A
special emphasis is made to the case where $Z$ is real spherical.


title:
An Improved One-to-All Broadcasting in Higher Dimensional
  Eisenstein-Jacobi Networks

abstract:
  Recently, a higher dimensional Eisenstein-Jacobi networks, has been proposed
in [22], which is shown that they have better average distance with more number
of nodes than a single dimensional EJ networks. Some communication algorithms
such as one-to-all and all-to-all communications are well known and used in
interconnection networks. In one-to-all communication, a source node sends a
message to every other node in the network. Whereas, in all-to-all
communication, every node is considered as a source node and sends its message
to every other node in the network. In this paper, an improved one-to-all
communication algorithm in higher dimensional EJ networks is presented. The
paper shows that the proposed algorithm achieves a lower average number of
steps to receiving the broadcasted message. In addition, since the links are
assumed to be half-duplex, the all-to-all broadcasting algorithm is divided
into three phases. The simulation results are discussed and showed that the
improved one-to-all algorithm achieves better traffic performance than the
well-known one-to-all algorithm and has 2.7% less total number of senders


title:
Gamma-ray blazar spectra with H.E.S.S. II mono analysis: the case of PKS
  2155-304 and PG 1553+113

abstract:
  The addition of a 28 m Cherenkov telescope (CT5) to the H.E.S.S. array
extended the experiment's sensitivity to lower energies. The lowest energy
threshold is obtained using monoscopic analysis of data taken with CT5,
providing access to gamma-ray energies below 100 GeV. Such an extension of the
instrument's energy range is particularly beneficial for studies of Active
Galactic Nuclei with soft spectra, as expected for those at a redshift > 0.5.
The high-frequency peaked BL Lac objects PKS 2155-304 (z = 0.116) and PG
1553+113 (0.43 < z < 0.58) are among the brightest objects in the gamma-ray
sky, both showing clear signatures of gamma-ray absorption at E > 100 GeV
interpreted as being due to interactions with the extragalactic background
light (EBL). Multiple observational campaigns of PKS 2155-304 and PG 1553+113
were conducted during 2013 and 2014 using the full H.E.S.S. II instrument. A
monoscopic analysis of the data taken with the new CT5 telescope was developed
along with an investigation into the systematic uncertainties on the spectral
parameters. The energy spectra of PKS 2155-304 and PG 1553+113 were
reconstructed down to energies of 80 GeV for PKS 2155-304, which transits near
zenith, and 110 GeV for the more northern PG 1553+113. The measured spectra,
well fitted in both cases by a log-parabola spectral model (with a 5.0 sigma
statistical preference for non-zero curvature for PKS 2155-304 and 4.5 sigma
for PG 1553+113), were found consistent with spectra derived from
contemporaneous Fermi-LAT data, indicating a sharp break in the observed
spectra of both sources at E ~ 100 GeV. When corrected for EBL absorption, the
intrinsic H.E.S.S. II mono and Fermi-LAT spectrum of PKS 2155-304 was found to
show significant curvature. For PG 1553+113, however, no significant detection
of curvature in the intrinsic spectrum could be found within statistical and
systematic uncertainties.


title:
The formalism for energy changing rate of an accelerated atom coupled
  with electromagnetic vacuum fluctuations

abstract:
  The structure of the rate of variation of the atomic energy for an arbitrary
stationary motion of the atom in interaction with a quantum electromagnetic
field is investigated. Our main purpose is to rewrite the formalism in Ref.
\cite{zz} and to deduce the general expressions of the Einstein A coefficients
of an atom on an arbitrary stationary trajectory. The total rate of change of
the energy and Einstein coefficients of the atom near a plate with finite
temperature or acceleration are also investigated.


title:
Transient Provisioning and Performance Evaluation for Cloud Computing
  Platforms: A Capacity Value Approach

abstract:
  User demand on the computational resources of cloud computing platforms
varies over time. These variations in demand can be predictable or
unpredictable, resulting in `bursty' fluctuations in demand. Furthermore,
demand can arrive in batches, and users whose demands are not met can be
impatient. We demonstrate how to compute the expected revenue loss over a
finite time horizon in the presence of all these model characteristics through
the use of matrix analytic methods. We then illustrate how to use this
knowledge to make frequent short term provisioning decisions --- transient
provisioning. It is seen that taking each of the characteristics of fluctuating
user demand (predictable, unpredictable, batchy) into account can result in a
substantial reduction of losses. Moreover, our transient provisioning framework
allows for a wide variety of system behaviors to be modeled and gives simple
expressions for expected revenue loss which are straightforward to evaluate
numerically.


title: Quantum Theory of Amplification in RS

abstract:
  The equations for the amplitudes of transition probabilities are found. The
resonance frequency of the system is calculated. It is shown the dependence of
the resonance frequency on the initial transverse coordinate of an electron.
This dependence is analized.


title: Killing the Hofstadter butterfly, one bond at a time

abstract:
  Electronic bands in a square lattice when subjected to a perpendicular
magnetic field form the Hofstadter butterfly pattern. We study the evolution of
this pattern as a function of bond percolation disorder (removal or dilution of
lattice bonds). With increasing concentration of the bonds removed, the
butterfly pattern gets smoothly decimated. However, in this process of
decimation, bands develop interesting characteristics and features. For
example, in the high disorder limit, some butterfly-like pattern still persists
even as most of the states are localized. We also analyze, in the low disorder
limit, the effect of percolation on wavefunctions (using inverse participation
ratios) and on band gaps in the spectrum. We explain and provide the reasons
behind many of the key features in our results by analyzing small clusters and
finite size rings. Furthermore, we study the effect of bond dilution on
transverse conductivity($\sigma_{xy}$). We show that starting from the clean
limit, increasing disorder reduces $\sigma_{xy}$ to zero, even though the
strength of percolation is smaller than the classical percolation threshold.
This shows that the system undergoes a direct transition from a integer quantum
Hall state to a localized Anderson insulator beyond a critical value of bond
dilution. We further find that the energy bands close to the band edge are more
stable to disorder than at the band center. To arrive at these results we use
the coupling matrix approach to calculate Chern numbers for disordered systems.
We point out the relevance of these results to signatures in
magneto-oscillations.


title: Condensed Memory Networks for Clinical Diagnostic Inferencing

abstract:
  Diagnosis of a clinical condition is a challenging task, which often requires
significant medical investigation. Previous work related to diagnostic
inferencing problems mostly consider multivariate observational data (e.g.
physiological signals, lab tests etc.). In contrast, we explore the problem
using free-text medical notes recorded in an electronic health record (EHR).
Complex tasks like these can benefit from structured knowledge bases, but those
are not scalable. We instead exploit raw text from Wikipedia as a knowledge
source. Memory networks have been demonstrated to be effective in tasks which
require comprehension of free-form text. They use the final iteration of the
learned representation to predict probable classes. We introduce condensed
memory neural networks (C-MemNNs), a novel model with iterative condensation of
memory representations that preserves the hierarchy of features in the memory.
Experiments on the MIMIC-III dataset show that the proposed model outperforms
other variants of memory networks to predict the most probable diagnoses given
a complex clinical scenario.


title:
Homodyne versus photon-counting quantum trajectories for dissipative
  Kerr resonators with two-photon driving

abstract:
  We investigate two different kinds of quantum trajectories for a nonlinear
photon resonator subject to two-photon pumping, a configuration recently
studied for the generation of photonic Schroedinger cat states. In the absence
of feedback control and in the strong-driving limit, the steady-state density
matrix is a statistical mixture of two states with equal weight. While along a
single photon-counting trajectory the systems intermittently switches between
an odd and an even cat state, we show that upon homodyne detection the
situation is different. Indeed, homodyne quantum trajectories reveal switches
between coherent states of opposite phase.


title:
Spectral imaging of topological edge states in plasmonic waveguide
  arrays

abstract:
  We report on the observation of a topologically protected edge state at the
interface between two topologically distinct domains of the
Su-Schrieffer-Heeger model, which we implement in arrays of evanescently
coupled dielectric-loaded surface plasmon polariton waveguides. Direct evidence
of the topological character of the edge state is obtained through several
independent experiments: Its spatial localization at the interface as well as
the restriction to one sublattice is confirmed by real-space leakage radiation
microscopy. The corresponding momentum-resolved spectrum obtained by Fourier
imaging reveals the midgap position of the edge state as predicted by theory.


title: Light Induced Degradation of CH_3NH_3PbI_3 Thin Film

abstract:
  The stability of CH3NH3PbI3 was investigated by observing the damage on a
co-evaporated film irradiated by a blue laser in ultrahigh vacuum. X-ray
photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were
employed to investigate the irradiation effects on the surface. The core levels
of perovskite were observed to shift toward higher binding energy (BE) during
the irradiation, suggesting that surface became more n-type. Metallic Pb
appeared after 120 minutes of irradiation, indicating that the film has started
to decompose. The decomposition saturated after about 480 minutes of
irradiation when the ratio of metallic Pb to total Pb was about 33%.
Furthermore, the film was no longer continuous after irradiation because of the
stress change after irradiation, as the substrate Au and oxygen were detected
by XPS. SEM images also show a roughened surface after irradiation. The results
strongly indicate that the perovskite is sensitive to the laser irradiation,
and the decomposition is a self-limiting process.


title:
Supernova equations of state including full nuclear ensemble with
  in-medium effects

abstract:
  We construct new equations of state for baryons at sub-nuclear densities for
the use in core-collapse supernova simulations. The abundance of various nuclei
is obtained together with thermodynamic quantities. The formulation is an
extension of the previous model, in which we adopted the relativistic mean
field theory with the TM1 parameter set for nucleons, the quantum approach for
$d$, $t$, $h$ and $\alpha$ as well as the liquid drop model for the other
nuclei under the nuclear statistical equilibrium. We reformulate the model of
the light nuclei other than $d$, $t$, $h$ and $\alpha$ based on the
quasi-particle description. Furthermore, we modify the model so that the
temperature dependences of surface and shell energies of heavy nuclei could be
taken into account. The pasta phases for heavy nuclei and the Pauli- and
self-energy shifts for $d$, $t$, $h$ and $\alpha$ are taken into account in the
same way as in the previous model. We find that nuclear composition is
considerably affected by the modifications in this work, whereas
thermodynamical quantities are not changed much. In particular, the washout of
shell effect has a great impact on the mass distribution above $T \sim 1$ MeV.
This improvement may have an important effect on the rates of electron captures
and coherent neutrino scatterings on nuclei in supernova cores.


title:
Spatially inhomogeneous and irrotational geometries admitting Intrinsic
  Conformal Symmetries

abstract:
  "Diagonal" spatially inhomogeneous (SI) models are introduced under the
assumption of the existence of (proper) intrinsic symmetries and can be seen,
in some sense, complementary to the Szekeres models. The structure of this
class of spacetimes can be regarded as a generalization of the (twist-free)
Locally Rotationally Symmetric (LRS) geometries without any global isometry
containing, however, these models as special cases. We consider geometries
where a six-dimensional algebra $\mathcal{IC}$ of Intrinsic Conformal Vector
Fields (ICVFs) exists acting on a $2-$dimensional (pseudo)-Riemannian manifold.
Its members $\mathbf{X}_{\alpha }$, constituted of 3 Intrinsic Killing Vector
Fields (IKVFs) and 3 \emph{proper} and \emph{gradient} ICVFs, as well as the
specific form of the gravitational field are given explicitly. An interesting
consequence, in contrast with the Szekeres models, is the immediate existence
of \emph{conserved quantities along null geodesics}. We check computationally
that the magnetic part $H_{ab}$ of the Weyl tensor vanishes whereas the shear
$\sigma_{ab}$ and the electric part $E_{ab}$ share a common eigenframe
irrespective of the fluid interpretation of the models. A side result is the
fact that the spacetimes are foliated by a set of \emph{conformally flat }
$3-$dimensional \emph{timelike} slices when the anisotropy of the
\emph{flux-free} fluid is described only in terms of the 3 \emph{principal
inhomogeneous "pressures"} $p_{\alpha}$ or equivalently when the Ricci tensor
shares the same basis of eigenvectors with $\sigma_{ab}$ and $E_{ab}$. The
conformal flatness also indicates that a \emph{10-dimensional algebra} of ICVFs
$\mathbf{\Xi}$ acting on the $3-$dimensional timelike slices is highly possible
to exist enriching in that way the set of conserved quantities admitted by the
SI models found in the present paper.


title:
Self consistent calculation of the nuclear composition in hot and dense
  stellar matter

abstract:
  We investigate the mass fractions and in-medium properties of heavy nuclei in
stellar matter at characteristic densities and temperatures for supernova (SN)
explosions. The individual nuclei are described within the compressible
liquid-drop model taking into account modifications of bulk, surface and
Coulomb energies. The equilibrium properties of nuclei and the full ensemble of
heavy nuclei are calculated self-consistently. It is found that heavy nuclei in
the ensemble are either compressed or decompressed depending on the isospin
asymmetry of the system. The compression or decompression has a little
influence on the binding energies, total mass fractions and average mass
numbers of heavy nuclei, although the equilibrium densities of individual
nuclei themselves are changed appreciably above one hundredth of normal nuclear
density. We find that nuclear structure in single nucleus approximation
deviates from the actual one obtained in the multi-nucleus description, since
the density of free nucleons is different between these two descriptions. This
study indicates that a multi-nucleus description is required to realistically
account for in-medium effects on the nuclear structure in supernova matter.


title:
Communication-Avoiding Parallel Algorithms for Solving Triangular
  Systems of Linear Equations

abstract:
  We present a new parallel algorithm for solving triangular systems with
multiple right hand sides (TRSM). TRSM is used extensively in numerical linear
algebra computations, both to solve triangular linear systems of equations as
well as to compute factorizations with triangular matrices, such as Cholesky,
LU, and QR. Our algorithm achieves better theoretical scalability than known
alternatives, while maintaining numerical stability, via selective use of
triangular matrix inversion. We leverage the fact that triangular inversion and
matrix multiplication are more parallelizable than the standard TRSM algorithm.
By only inverting triangular blocks along the diagonal of the initial matrix,
we generalize the usual way of TRSM computation and the full matrix inversion
approach. This flexibility leads to an efficient algorithm for any ratio of the
number of right hand sides to the triangular matrix dimension. We provide a
detailed communication cost analysis for our algorithm as well as for the
recursive triangular matrix inversion. This cost analysis makes it possible to
determine optimal block sizes and processor grids a priori. Relative to the
best known algorithms for TRSM, our approach can require asymptotically fewer
messages, while performing optimal amounts of computation and communication in
terms of words sent.


title:
Another Approach to Juhl's Conformally Covariant Differential Operators
  from $S^n$ to $S^{n-1}$

abstract:
  A family $({\mathbf D}_\lambda)_{\lambda\in \mathbb C}$ of differential
operators on the sphere $S^n$ is constructed. The operators are conformally
covariant for the action of the subgroup of conformal transformations of $S^n$
which preserve the smaller sphere $S^{n-1}\subset S^n$. The family of
conformally covariant differential operators from $S^n$ to $S^{n-1}$ introduced
by A. Juhl is obtained by composing these operators on $S^n$ and taking
restrictions to $S^{n-1}$.


title: On a Well-behaved Relational Generalisation of Rough Set Approximations

abstract:
  We examine non-dual relational extensions of rough set approximations and
find an extension which satisfies surprisingly many of the usual rough set
properties. We then use this definition to give an explanation for an
observation made by Samanta and Chakraborty in their recent paper [P. Samanta
and M.K. Chakraborty. Interface of rough set systems and modal logics: A
survey. Transactions on Rough Sets XIX, pages 114-137, 2015].


title:
Relaxation dynamics of two coherently coupled one-dimensional bosonic
  gases

abstract:
  In this work we consider the non-equilibrium dynamics of two tunnel coupled
bosonic gases which are created from the coherent splitting of a
one-dimensional gas. The consequences of the tunneling both in the
non-stationary regime as well as at large time are investigated and compared
with equilibrium results. In particular, within a semiclassical approximation,
we compute correlation functions for the relative phase which are
experimentally measurable and we observe a transient regime displaying
oscillations as a function of the distance. The steady regime is very well
approximated by a thermal state with a temperature independent of the tunneling
strength.


title: Combinatorial semi-bandit with known covariance

abstract:
  The combinatorial stochastic semi-bandit problem is an extension of the
classical multi-armed bandit problem in which an algorithm pulls more than one
arm at each stage and the rewards of all pulled arms are revealed. One
difference with the single arm variant is that the dependency structure of the
arms is crucial. Previous works on this setting either used a worst-case
approach or imposed independence of the arms. We introduce a way to quantify
the dependency structure of the problem and design an algorithm that adapts to
it. The algorithm is based on linear regression and the analysis develops
techniques from the linear bandit literature. By comparing its performance to a
new lower bound, we prove that it is optimal, up to a poly-logarithmic factor
in the number of pulled arms.


title:
An algorithm to assign musical prime commas to every prime number and
  construct a universal and compact free Just Intonation musical notation

abstract:
  Musical frequencies in Just Intonation are comprised of rational numbers. The
structure of rational numbers is determined by prime factorisations. Just
Intonation frequencies can be split into two components. The larger component
uses only integer powers of the first two primes, 2 and 3. The smaller
component decomposes into a series of microtonal adjustments, one for each
prime number 5 and above present in the original frequency. The larger 3-limit
component can be notated using scientific pitch notation modified to use
Pythagorean tuning. The microtonal adjustments can be notated using rational
commas which are built up from prime commas. This gives a notation system for
the whole of free-JI, called Rational Comma Notation. RCN is compact since all
microtonal adjustments can be represented by a single notational unit based on
a rational number. RCN has different versions depending on the choice of
algorithm to assign a prime comma to each prime number. Two existing algorithms
SAG and KG2 are found in the literature. A novel algorithm DR is developed
based on discussion of mathematical and musical criteria for algorithm design.
Results for DR are presented for primes below 1400. Some observations are made
about these results and their applications, including shorthand notation and
pitch class lattices. Results for DR are compared with those for SAG and KG2.
Translation is possible between any two free-JI notations and any two versions
of RCN since they all represent the same underlying set of rational numbers.


title: A note on simple randomly switched linear systems

abstract:
  We construct a planar process that switches randomly between the flows of two
linear systems built from two Hurwitz matrices (all eigenvalues have negative
real parts). The goal here is to study the long time behaviour according to the
switching rates. We will see that, even if the two systems are stable, it is
possible to obtain a blow up if we choose the switching rates wisely. Finally
we will see a connection, between the tail of the invariant measure (when the
switching times follow an exponential law) and the existence of a deterministic
control that makes the process explode.


title:
Nonconforming Immersed Finite Element Spaces For Elliptic Interface
  Problems

abstract:
  In this paper, we use a unified framework introduced in [3] to study two
classes of nonconforming immersed finite element (IFE) spaces with integral
value degrees of freedom. The shape functions on interface elements are
piecewise polynomials defined on sub-elements separated either by the actual
interface or its line approximation. In this unified framework, we use the
invertibility of the well known Sherman-Morison systems to prove the existence
and uniqueness of shape functions on each interface element in either
rectangular or triangular mesh. Furthermore, we develop a multi-edge expansion
for piecewise functions and a group of identities for nonconforming IFE
functions which enable us to show that these IFE spaces have the optimal
approximation capability.


title:
Dust in brown dwarfs and extra-solar planets V. Cloud formation in
  carbon- and oxygen-rich environment

abstract:
  Recent observations indicate potentially carbon-rich exoplanet atmospheres.
Spectral fitting methods for brown dwarfs and exoplanets have invoked the C/O
ratio as additional parameter but carbon-rich cloud formation modeling is a
challenge for the models applied. The determination of the habitable zone for
exoplanets requires the treatment of cloud formation in chemically different
regimes. Disk models show that carbon-rich or near-carbon-rich niches may
emerge and cool carbon planets may trace these particular stages of planetary
evolution. We extend our kinetic cloud formation model by including carbon seed
formation and the formation of C[s], TiC[s], SiC[s], KCl[s], and MgS[s] by
gas-surface reactions. The seed formation efficiency is lower in carbon-rich
atmospheres than in oxygen-rich gases due to carbon being a very effective
growth species. The consequence is that less particles will make up a cloud for
C/O_0>1. The cloud particles will be smaller in size than in an oxygen-rich
atmosphere. An increasing initial C/O ratio does not revert this trend because
a much greater abundance of condensible gas species exists in a rich carbon
environment. Cloud particles are generally made of a mix of materials: carbon
dominates if C/O_0>1 and silicates dominate if C/O_0<1. 80-90% carbon is
reached only in extreme cases where C/O_0=3.0 or 10.0. Carbon-rich atmospheres
would form clouds that are made of particles of height-dependent mixed
compositions, sizes and numbers. The remaining gas-phase is far less depleted
than in an oxygen-rich atmosphere. Typical tracer molecules are HCN and C2H2 in
combination with a featureless, smooth continuum due to a carbonaceous cloud
cover, unless the cloud particles become crystalline.


title:
Axion-like particles and the propagation of gamma rays over astronomical
  distances

abstract:
  In this mini-review, possible manifestations of mixing between axion-like
particles (ALPs) and energetic photons propagating over astronomical distances
are considered. We discuss the evidence for the anomalous transparency of the
Universe from observations of ensembles of distant gamma-ray sources, present
the general formalism for the ALP-photon mixing and explain how this mechanism
may remove the anomaly. We present relevant values of ALP parameters and
discuss future ways to verify the scenario and to discover the particle in
question.


title:
Mixing of charged and neutral Bose condensates at nonzero temperature
  and magnetic field

abstract:
  It is expected that in the interior of compact stars a proton superconductor
coexists with and couples to a neutron superfluid. Starting from a
field-theoretical model for two complex scalar fields - one of which is
electrically charged - we derive a Ginzburg-Landau potential which includes
entrainment between the two fluids and temperature effects from thermal
excitations of the two scalar fields and the gauge field. The Ginzburg-Landau
description is then used for an analysis of the phase structure in the presence
of an external magnetic field. In particular, we study the effect of the
superfluid on the flux tube phase by computing the various critical magnetic
fields and deriving an approximation for the flux tube interaction. As a
result, we point out differences to the naive expectations from an isolated
superconductor, for instance the existence of a first-order flux tube onset,
resulting in a more complicated phase structure in the region between type-I
and type-II superconductivity.


title:
K\"ahler metrics with cone singularities along a divisor of bounded
  Ricci curvature

abstract:
  Let $D$ be a smooth divisor in a compact complex manifold $X$ and let $\beta
\in (0,1)$. We show that in any positive co-homology class on $X$ there is a
K\"ahler metric with cone angle $2\pi\beta$ along $D$ which has bounded Ricci
curvature. We use this result together with the Aubin-Yau continuity method to
give an alternative proof of a well-known existence theorem for Kahler-Einstein
metrics with cone singularities.


title: On the RG Flow in the Two-Dimensional Coset Models

abstract:
  We consider a RG flow in a general $\hat{su}(2)$ coset model perturbed by the
least relevant field. The perturbing field as well as some particular fields of
dimension close to one are constructed recursively in terms of lower level
fields. Using this construction we obtain the structure constants and the
four-point correlation functions in the leading order. This allows us to
compute the mixing coefficients among the fields in the UV and the IR theory.


title:
Broadcast Strategies and Performance Evaluation of IEEE 802.15.4 in
  Wireless Body Area Networks WBAN

abstract:
  The rapid advances in sensors and ultra-low power wireless communication has
enabled a new generation of wireless sensor networks: Wireless Body Area
Networks (WBAN). To the best of our knowledge the current paper is the first to
address broadcast in WBAN. We first analyze several broadcast strategies
inspired from the area of Delay Tolerant Networks (DTN). The proposed
strategies are evaluated via the OMNET++ simulator that we enriched with
realistic human body mobility models and channel models issued from the recent
research on biomedical and health informatics. Contrary to the common
expectation, our results show that existing research in DTN cannot be
transposed without significant modifications in WBANs area. That is, existing
broadcast strategies for DTNs do not perform well with human body mobility.
However, our extensive simulations give valuable insights and directions for
designing efficient broadcast in WBAN. Furthermore, we propose a novel
broadcast strategy that outperforms the existing ones in terms of end-to-end
delay, network coverage and energy consumption. Additionally, we performed
investigations of independent interest related to the ability of all the
studied strategies to ensure the total order delivery property when stressed
with various packet rates. These investigations open new and challenging
research directions.


title: A Parameter Estimation Method Using Linear Response Statistics

abstract:
  This paper presents a new parameter estimation method for It\^{o} diffusions
such that the resulting model predicts the equilibrium statistics as well as
the sensitivities of the underlying system to external disturbances. Our
formulation does not require the knowledge of the underlying system, however we
assume that the linear response statistics can be computed via the
fluctuation-dissipation theory. The main idea is to fit the model to a finite
set of "essential" statistics that is sufficient to approximate the linear
response operators. In a series of test problems, we will show the consistency
of the proposed method in the sense that if we apply it to estimate the
parameters in the underlying model, then we must obtain the true parameters.


title: On the computational power of affine automata

abstract:
  We investigate the computational power of affine automata (AfAs) introduced
in [4]. In particular, we present a simpler proof for how to change the
cutpoint for any affine language and a method how to reduce error in bounded
error case. Moreover, we address to the question of [4] by showing that any
affine language can be recognized by an AfA with certain limitation on the
entries of affine states and transition matrices. Lastly, we present the first
languages shown to be not recognized by AfAs with bounded-error.


title: Recommender Engine for Continuous Time Quantum Monte Carlo Methods

abstract:
  Recommender systems play an essential role in the modern business world. They
recommend favorable items like books, movies, and search queries to users based
on their past preferences. Applying similar ideas and techniques to Monte Carlo
simulations of physical systems boosts their efficiency without sacrificing
accuracy. Exploiting the quantum to classical mapping inherent in the
continuous-time quantum Monte Carlo methods, we construct a classical molecular
gas model to reproduce the quantum distributions. We then utilize powerful
molecular simulation techniques to propose efficient quantum Monte Carlo
updates. The recommender engine approach provides a general way to speed up the
quantum impurity solvers.