title:
Domain walls in two-dimensional nematics confined in a small circular
  cavity

abstract:
  Using Monte Carlo simulation, we study a fluid of two-dimensional hard rods
inside a small circular cavity bounded by a hard wall, from the dilute regime
to the high-density, layering regime. Both planar and homeotropic anchoring of
the nematic director can be induced at the walls through a free-energy penalty.
The circular geometry creates frustration in the nematic phase and a
polar-symmetry configuration with a distorted director field plus two $+1/2$
disclinations is created. At higher densities, a quasi-uniform structure is
observed with a (minimal) director distortion which is relaxed via the
formation of orientational domain walls. This novel structure is not predicted
by elasticity theory and is similar to the step-like structures observed in
three-dimensional hybrid slit pores. We speculate that the formation of domain
walls is a general mechanism to relax elastic stresses in conditions of strong
surface anchoring and severe spatial confinement.


title:
Feasibility of light scalars in a class of two-Higgs-doublet models and
  their decay signatures

abstract:
  We demonstrate that light charged and extra neutral scalars in the (100-200)
GeV mass range pass the potentially dangerous flavor constraints in a
particular class of two-Higgs-doublet model which has appropriately suppressed
flavor-changing neutral currents at tree level. We study their decay branching
ratios into various fermionic final states and comment on the possibility of
their detection in the collider experiments. We also remark on how their
trademark decay signatures can be used to discriminate them from the light
nonstandard scalars predicted in other two-Higgs-doublet models.


title:
Solutions of the focusing nonradial critical wave equation with the
  compactness property

abstract:
  Consider the focusing energy-critical wave equation in space dimension 3, 4
or 5. In a previous paper, we proved that any solution which is bounded in the
energy space converges, along a sequence of times and in some weak sense, to a
solution with the compactness property, that is a solution whose trajectory
stays in a compact subset of the energy space up to space translation and
scaling. It is conjectured that the only solutions with the compactness
property are stationary solutions and solitary waves that are Lorentz
transforms of the former. In this note we prove this conjecture with an
additional non-degeneracy assumption related to the invariances of the elliptic
equation satisfied by stationary solutions. The proof uses a standard
monotonicity formula, modulation theory, and a new channel of energy argument
which is independent of the space dimension.


title: On a conjecture of Gluck

abstract:
  Let $F(G)$ and $b(G)$ respectively denote the Fitting subgroup and the
largest degree of an irreducible complex character of a finite group $G$. A
well-known conjecture of D. Gluck claims that if $G$ is solvable then
$|G:F(G)|\leq b(G)^{2}$. We confirm this conjecture in the case where $|F(G)|$
is coprime to 6. We also extend the problem to arbitrary finite groups and
prove several results showing that the largest irreducible character degree of
a finite group strongly controls the group structure.


title:
Creature forcing and five cardinal characteristics in Cicho\'{n}'s
  diagram

abstract:
  We use a (countable support) creature construction to show that consistently
  \[
  \mathfrak d=\aleph_1=
  \text{cov}(\text{NULL})
  <
  \text{non}(\text{MEAGER})
  <
  \text{non}(\text{NULL})
  <
  \text{cof}(\text{NULL})
  <
  2^{\aleph_0}. \]
  The same method shows the consistency of
  \[
  \mathfrak d=\aleph_1=
  \text{cov}(\text{NULL})
  <
  \text{non}(\text{NULL})
  <
  \text{non}(\text{MEAGER})
  <
  \text{cof}(\text{NULL})
  <
  2^{\aleph_0}.
  \]


title: Feedback control of inertial microfluidics using axial control forces

abstract:
  Inertial microfluidics is a promising tool for many lab-on-a-chip
applications. Particles in channel flows with Reynolds numbers above one
undergo cross-streamline migration to a discrete set of equilibrium positions
in square and rectangular channel cross sections. This effect has been used
extensively for particle sorting and the analysis of particle properties. Using
the lattice Boltzmann method, we determine equilibrium positions in square and
rectangular cross sections and classify their types of stability for different
Reynolds numbers, particle sizes, and channel aspect ratios. Our findings
thereby help to design microfluidic channels for particle sorting. Furthermore,
we demonstrate how an axial control force, which slows down the particles,
shifts the stable equilibrium position towards the channel center. Ultimately,
the particles then stay on the centerline for forces exceeding a threshold
value. This effect is sensitive to particle size and channel Reynolds number
and therefore suggests an efficient method for particle separation. In
combination with a hysteretic feedback scheme, we can even increase particle
throughput.


title: Weighted quantile correlation test for the logistic family

abstract:
  We summarize the results of investigating the asymptotic behavior of the
weighted quantile correlation tests for the location-scale family associated to
the logistic distribution. Explicit representations of the limiting
distribution are given in terms of integrals of weighted Brownian bridges or
alternatively as infinite series of independent Gaussian random variables. The
power of this test and the test for the location logistic family against some
alternatives are demonstrated by numerical simulations.


title:
Losses-based test of wave-particle duality with Mach-Zehnder
  interferometers

abstract:
  Wave-particle duality of photons with losses in the Mach-Zehnder
interferometer (MZI) is investigated experimentally and theoretically. The
experiment is done with the standard MZI with the beam splitter or the beam
merger being continuously varied. The losses are deliberately introduced either
inside the MZI (the two arms between the beam splitter and beam mergers) or
outside the MZI (after the beam merger). It is proved that the unbalanced
losses have great influence on the predictability $P$ (particle nature) and
visibility $V$ (wave nature). For the former case the duality inequality holds
while for the later the duality inequality is ``violated''. We get $P^2+V^2>1$.
This ``violation'' could be eliminated in principle by switching the two paths
and detectors and then averaging the results. The observed results can be
exactly explained theoretically. The experiment is done with coherent beam,
instead of single photons, and we have proved that they are exactly equivalent
in duality experiment with MZI.


title: Detrended Structure-Function in Fully Developed Turbulence

abstract:
  The classical structure-function (SF) method in fully developed turbulence or
for scaling processes in general is influenced by large-scale energetic
structures, known as infrared effect. Therefore, the extracted scaling
exponents $\zeta(n)$ might be biased due to this effect. In this paper, a
detrended structure-function (DSF) method is proposed to extract scaling
exponents by constraining the influence of large-scale structures. This is
accomplished by removing a $1$st-order polynomial fitting within a window size
$\ell$ before calculating the velocity increment. By doing so, the scales
larger than $\ell$, i.e., $r\ge \ell$, are expected to be removed or
constrained. The detrending process is equivalent to be a high-pass filter in
physical domain. Meanwhile the intermittency nature is retained. We first
validate the DSF method by using a synthesized fractional Brownian motion for
mono-fractal processes and a lognormal process for multifractal random walk
processes. The numerical results show comparable scaling exponents $\zeta(n)$
and singularity spectra $D(h)$ for the original SFs and DSFs. When applying the
DSF to a turbulent velocity obtained from a high Reynolds number wind tunnel
experiment with $Re_{\lambda}\simeq 720$, the 3rd-order DSF demonstrates a
clear inertial range with $\mathcal{B}_3(\ell)\simeq 4/5\epsilon \ell$ on the
range $10<\ell/\eta<1000$, corresponding to a wavenumber range
$0.001<k\eta<0.1$. This inertial range is consistent with the one predicted by
the Fourier power spectrum. The directly measured scaling exponents $\zeta(n)$
(resp. singularity spectrum $D(h)$) agree very well with a lognormal model with
an intermittent parameter $\mu=0.33$. Due to large-scale effects, the results
provided by the SFs are biased.


title: A note on normal generation and generation of groups

abstract:
  In this note we study sets of normal generators of finitely presented
residually $p$-finite groups. We show that if an infinite, finitely presented,
residually $p$-finite group $G$ is normally generated by $g_1,\dots,g_k$ with
order $n_1,\dots,n_k \in \{1,2,\dots \} \cup \{\infty \}$, then
$$\beta_1^{(2)}(G) \leq k-1-\sum_{i=1}^{k} \frac1{n_i},$$ where
$\beta_1^{(2)}(G)$ denotes the first $\ell^2$-Betti number of $G$. We also show
that any $k$-generated group with $\beta_1^{(2)}(G) \geq k-1-\varepsilon$ must
have girth greater than or equal $1/\varepsilon$.


title:
Resolvent expansions and continuity of the scattering matrix at embedded
  thresholds: the case of quantum waveguides

abstract:
  We present an inversion formula which can be used to obtain resolvent
expansions near embedded thresholds. As an application, we prove for a class of
quantum waveguides the absence of accumulation of eigenvalues and the
continuity of the scattering matrix at all thresholds.


title:
Inducing Non-Classical Lasing Via Periodic Drivings in Circuit Quantum
  Electrodynamics

abstract:
  We show how a pair of superconducting qubits coupled to a microwave cavity
mode can be used to engineer a single-atom laser that emits light into a
non-classical state. Our scheme relies on the dressing of the qubit-field
coupling by periodic modulations of the qubit energy. In the dressed basis, the
radiative decay of the first qubit becomes an effective incoherent pumping
mechanism that injects energy into the system, hence turning dissipation to our
advantage. A second, auxiliary qubit is used to shape the decay within the
cavity, in such a way that lasing occurs in a squeezed basis of the cavity
mode. We characterize the system both by mean-field theory and exact
calculations. Our work may find applications in the generation of squeezing and
entanglement in circuit QED, as well as in the study of dissipative many-body
phase transitions.


title: Highly symmetric POVMs and their informational power

abstract:
  We discuss the dependence of the Shannon entropy of normalized finite rank-1
POVMs on the choice of the input state, looking for the states that minimize
this quantity. To distinguish the class of measurements where the problem can
be solved analytically, we introduce the notion of highly symmetric POVMs and
classify them in dimension two (for qubits). In this case we prove that the
entropy is minimal, and hence the relative entropy (informational power) is
maximal, if and only if the input state is orthogonal to one of the states
constituting a POVM. The method used in the proof, employing the Michel theory
of critical points for group action, the Hermite interpolation and the
structure of invariant polynomials for unitary-antiunitary groups, can also be
applied in higher dimensions and for other entropy-like functions. The links
between entropy minimization and entropic uncertainty relations, the Wehrl
entropy and the quantum dynamical entropy are described.


title: Impact of local structure on the cosmic radio dipole

abstract:
  We investigate the contribution that a local over- or under-density can have
on linear cosmic dipole estimations. We focus here on radio surveys, such as
the NRAO VLA Sky Survey (NVSS), and forthcoming surveys such as those with the
LOw Frequency ARray (LOFAR), the Australian Square Kilometre Array Pathfinder
(ASKAP) and the Square Kilometre Array (SKA). The NVSS has already been used to
estimate the cosmic radio dipole; it was shown recently that this radio dipole
amplitude is larger than expected from a purely kinematic effect, assuming the
velocity inferred from the dipole of the cosmic microwave background. We show
here that a significant contribution to this excess could come from a local
void or similar structure. In contrast to the kinetic contribution to the radio
dipole, the structure dipole depends on the flux threshold of the survey and
the wave band, which opens the chance to distinguish the two contributions.


title:
Interferometry with non-classical motional states of a Bose-Einstein
  condensate

abstract:
  We demonstrate a two-pulse Ramsey-type interferometer for non-classical
motional states of a Bose-Einstein condensate in an anharmonic trap. The
control pulses used to manipulate the condensate wavefunction are obtained from
Optimal Control Theory and directly optimised to maximise the interferometric
contrast. They permit a fast manipulation of the atomic ensemble compared to
the intrinsic decay and many-body dephasing effects, and thus to reach an
interferometric contrast of 92% in the experimental implementation.


title: Optimisation of Bell inequalities with invariant Tsirelson bound

abstract:
  We consider a subclass of bipartite CHSH-type Bell inequalities. We
investigate operations, which leave their Tsirelson bound invariant, but change
their classical bound. The optimal observables are unaffected except for a
relative rotation of the two laboratories. We illustrate the utility of these
operations by giving explicit examples: We prove that for a fixed quantum state
and fixed measurement setup except for a relative rotation of the two
laboratories, there is a Bell inequality that is maximally violated for this
rotation, and we optimise some Bell inequalities with respect to the maximal
violation. Finally we optimise the qutrit to qubit ratio of some dimension
witnessing Bell inequalities.


title: Unveiling the environment surrounding LMXB SAX J1808.4-3658

abstract:
  Low-mass X-ray binaries (LMXBs) are a natural workbench to study accretion
disk phenomena and optimal background sources to measure elemental abundances
in the Interstellar medium (ISM). In high-resolution XMM-Newton spectra, the
LMXB SAX J1808.4-3658 showed in the past a neon column density significantly
higher than expected given its small distance, presumably due to additional
absorption from a neon-rich circumstellar medium (CSM). It is possible to
detect intrinsic absorption from the CSM by evidence of Keplerian motions or
outflows. For this purpose, we use a recent, deep (100 ks long),
high-resolution Chandra/LETGS spectrum of SAX J1808.4-3658 in combination with
archival data. We estimated the column densities of the different absorbers
through the study of their absorption lines. We used both empirical and
physical models involving photo- and collisional-ionization in order to
determine the nature of the absorbers. The abundances of the cold interstellar
gas match the solar values as expected given the proximity of the X-ray source.
For the first time in this source, we detected neon and oxygen blueshifted
absorption lines that can be well modeled with outflowing photoionized gas. The
wind is neon rich (Ne/O>3) and may originate from processed, ionized gas near
the accretion disk or its corona. The kinematics (v=500-1000 km/s) are indeed
similar to those seen in other accretion disks. We also discovered a system of
emission lines with very high Doppler velocities (v~24000 km/s) originating
presumably closer to the compact object. Additional observations and UV
coverage are needed to accurately determine the wind abundances and its
ionization structure.


title:
Study of nucleonic matter with a consistent two- and three-body
  perturbative chiral interaction

abstract:
  We calculate perturbatively the energy per nucleon in infinite nuclear matter
with a chiral N3LO (next-to-next-to-next-to-leading order) two-body potential
plus a N2LO three-body force (3BF). The 3BF low-energy constants which cannot
be constrained by two-body observables are chosen such as to reproduce the A=3
binding energies and the triton Gamow-Teller matrix element. This enables to
study the nuclear matter equation of state in a parameter-free approach.


title:
Infrared-dressed entanglement of cold open-shell polar molecules for
  universal matchgate quantum computing

abstract:
  Implementing a scalable quantum information processor using polar molecules
in optical lattices requires precise control over the long-range dipole-dipole
interaction between molecules in selected lattice sites. We present here a
scheme using trapped open-shell $^2\Sigma$ polar molecules that allows dipolar
exchange processes between nearest and next-nearest neighbors to be controlled
to construct a generalized transverse Ising spin Hamiltonian with tunable $XX$,
$YY$ and $XY$ couplings in the rotating frame of the driving lasers. The scheme
requires a moderately strong bias magnetic field with near-infrared light to
provide local tuning of the qubit energy gap, and mid-infrared pulses to
perform rotational state transfer via stimulated Raman adiabatic passage. No
interaction between qubits is present in the absence of the infrared driving.
We analyze the fidelity of the resulting two-qubit matchgate, and demonstrate
its robustness as a function of the driving parameters. We discuss a realistic
application of the system for universal matchgate quantum computing in optical
lattices.


title: The adiabatic limit of Schr\"odinger operators on fibre bundles

abstract:
  We consider Schr\"odinger operators $H=-\Delta_{g_\varepsilon} + V$ on a
fibre bundle $M\stackrel{\pi}{\to}B$ with compact fibres and a metric
$g_\varepsilon$ that blows up directions perpendicular to the fibres by a
factor ${\varepsilon^{-1}\gg 1}$. We show that for an eigenvalue $\lambda$ of
the fibre-wise part of $H$, satisfying a local gap condition, and every $N\in
\mathbb{N}$ there exists a subspace of $L^2(M)$ that is invariant under $H$ up
to errors of order $\varepsilon^{N+1}$. The dynamical and spectral features of
$H$ on this subspace can be described by an effective operator on the
fibre-wise $\lambda$-eigenspace bundle $\mathcal{E}\to B$, giving detailed
asymptotics for $H$.


title:
Interstellar gamma-ray emission from cosmic rays in star-forming
  galaxies

abstract:
  Fermi/LAT observations of star-forming galaxies in the ~0.1-100GeV range have
made possible a first population study. Evidence was found for a correlation
between gamma-ray luminosity and tracers of the star formation activity.
Studying galactic cosmic rays (CRs) in various global conditions can yield
information about their origin and transport in the interstellar medium (ISM).
This work addresses the question of the scaling laws that can be expected for
the interstellar gamma-ray emission as a function of global galactic
properties, with the goal of establishing whether the current experimental data
in the GeV range can be constraining. I developed a 2D model for the
non-thermal emissions from steady-state CR populations interacting with the ISM
in star-forming galaxies. Most CR-related parameters were taken from Milky Way
studies, and a large number of galaxies were then simulated with sizes from 4
to 40kpc, several gas distributions, and star formation rates (SFR) covering
six orders of magnitude. The evolution of the gamma-ray luminosity over the
100keV-100TeV range is presented, with emphasis on the contribution of the
different emission processes and particle populations, and on the transition
between transport regimes. The model can reproduce the normalisation and trend
inferred from the Fermi/LAT population study over most of the SFR range. This
is obtained with a plain diffusion scheme, a single diffusion coefficient, and
the assumption that CRs experience large-scale volume-averaged interstellar
conditions. There is, however, no universal relation between high-energy
gamma-ray luminosity and star formation activity, as illustrated by the scatter
introduced by different galactic global properties and the downturn in
gamma-ray emission at the low end (abridged).


title:
Newly observed $B(5970)$ and the predictions of its spin and strange
  partners

abstract:
  Using the effective Lagrangian approach, we study the decay behavior of the
newly observed $B(5970)$ meson, which is assigned as the $2^3S_1$ state in the
$B$ meson family. What is more important is that we predict the information of
the partial and total decay decay widths of $B(2^1S_0)$, $B_s(2^1S_0)$ and
$B_s(2^3S_1)$ as the spin and strange partners of $B(5970)$, which is valuable
to future experimental search for these missing states.


title:
Iterative derivation of effective potentials to sample the
  conformational space of proteins at atomistic scale

abstract:
  The current capacity of computers makes it possible to perform simulations of
small systems with portable, explicit-solvent potentials achieving high degree
of accuracy. However, simplified models must be employed to exploit the
behaviour of large systems or to perform systematic scans of smaller systems.
While powerful algorithms are available to facilitate the sampling of the
conformational space, successful applications of such models are hindered by
the availability of simple enough potentials able to satisfactorily reproduce
known properties of the system. We develop an interatomic potential to account
for a number of properties of proteins in a computationally economic way. The
potential is defined within an all-atom, implicit solvent model by contact
functions between the different atom types. The associated numerical values can
be optimised by an iterative Monte Carlo scheme on any available experimental
data, provided that they are expressible as thermal averages of some
conformational properties. We test this model on three different proteins, for
which we also perform a scan of all possible point mutations with explicit
conformational sampling. The resulting models, optimised solely on a subset of
native distances, not only reproduce the native conformations within a few
Angstroms from the experimental ones, but show the cooperative transition
between native and denatured state and correctly predict the measured
free--energy changes associated with point mutations. Moreover, differently
from other structure-based models, our method leaves a residual degree of
frustration, which is known to be present in protein molecules.


title:
Dressed tunneling approximation for electronic transport through
  molecular transistors

abstract:
  A theoretical approach for the non-equilibrium transport properties of
nanoscale systems coupled to metallic electrodes with strong electron-phonon
interactions is presented. It consists in a resummation of the dominant Feynman
diagrams from the perturbative expansion in the coupling to the leads. We show
that this scheme eliminates the main pathologies found in previous simple
analytical approaches for the polaronic regime. The results for the spectral
and transport properties are compared with those from several other approaches
for a wide range of parameters. The method can be formulated in a simple way to
obtain the full counting statistics. Results for the shot and thermal noise are
presented.


title:
Resonant metamaterial absorbers for infrared spectral filtering:
  quasimodal analysis, design, fabrication and characterization

abstract:
  We present a modal analysis of metal-insulator-metal (MIM) based
metamaterials in the far infrared region. These structures can be used as
resonant reflection bandcut spectral filters that are independent of the
polarization and direction of incidence because of the excitation of quasimodes
(modes associated with a complex frequency) leading to quasi-total absorption.
We fabricated large area samples made of chromium nanorod gratings on top of
Si/Cr layers deposited on silicon substrate and measurements by Fourier
Transform spectrophotometry show good agreement with finite element
simulations. A quasimodal expansion method is developed to obtain a reduced
order model that fits very well full wave simulations and that highlights
excitation conditions of the modes.


title:
Convergence of clock processes and aging in Metropolis dynamics of a
  truncated REM

abstract:
  We study the aging behavior of a truncated version of the Random Energy Model
evolving under Metropolis dynamics. We prove that the natural time-time
correlation function defined through the overlap function converges to an
arcsine law distribution function, almost surely in the random environment and
in the full range of time scales and temperatures for which such a result can
be expected to hold. This establishes that the dynamics ages in the same way as
Bouchaud's REM-like trap model, thus extending the universality class of the
latter model. The proof relies on a clock process convergence result of a new
type where the number of summands is itself a clock process. This reflects the
fact that the exploration process of Metropolis dynamics is itself an aging
process, governed by its own clock. Both clock processes are shown to converge
to stable subordinators below certain critical lines in their time-scale and
temperature domains, almost surely in the random environment.


title: A non-perturbative mechanism for elementary particle mass generation

abstract:
  Taking inspiration from lattice QCD data, we argue that a finite
non-perturbative contribution to the quark mass is generated as a consequence
of the dynamical phenomenon of spontaneous chiral symmetry breaking, in turn
triggered by the explicitly breaking of chiral symmetry induced by the critical
Wilson term in the action. In pure lattice QCD this mass term cannot be
separated from the unavoidably associated linearly divergent contribution.
However, if QCD is enlarged to a theory where also a scalar field is present,
coupled to an SU(2) doublet of fermions via a Yukawa and a Wilson-like term,
then in the phase where the scalar field takes a non-vanishing expectation
value, a dynamically generated and "naturally" light fermion mass (numerically
unrelated to the expectation value of the scalar field) is conjectured to
emerge at a critical value of the Yukawa coupling where the symmetry of the
model is maximally enhanced. Masses dynamically generated in this way display a
natural hierarchy according to which the stronger is the strongest of the
interactions the fermion is subjected to the larger is its mass.


title: The dynamical gluon mass in the massless bound-state formalism

abstract:
  We describe the phenomenon of dynamical gluon mass generation within the
massless bound-state formalism, which constitutes the general framework for the
systematic implementation of the Schwinger mechanism in non-Abelian gauge
theories. The main ingredient of this formalism is the dynamical formation of
bound states with vanishing mass, which gives rise to effective vertices
containing massless poles; these vertices, in turn, trigger the Schwinger
mechanism, and allow for the gauge-invariant generation of an effective gluon
mass. In this particular approach, the gluon mass is directly related to
quantities that are intrinsic to the bound-state formation itself, such as the
"transition amplitude" and the corresponding "bound-state wave-function".
Specifically, a set of powerful relations discussed in the text, allows one to
determine the dynamical evolution of the gluon mass through a Bethe-Salpeter
equation, which controls the dynamics of the relevant wave-function. In
addition, it is possible to demonstrate that the massless bound-state formalism
is equivalent to the standard approach based on Schwinger-Dyson equations, thus
establishing a formal connection between two different nonperturbative
formalisms.


title:
Limited Feedback-Based Interference Alignment for Interfering
  Multi-Access Channels

abstract:
  A limited feedback-based interference alignment (IA) scheme is proposed for
the interfering multi-access channel (IMAC). By employing a novel
performance-oriented quantization strategy, the proposed scheme is able to
achieve the minimum overall residual inter-cell interference (ICI) with the
optimized transceivers under limited feedback. Consequently, the scheme
outperforms the existing counterparts in terms of system throughput. In
addition, the proposed scheme can be implemented with flexible antenna
configurations.


title: Warm formaldehyde in the Oph IRS 48 transitional disk

abstract:
  Simple molecules like H2CO and CH3OH in protoplanetary disks are the starting
point for the production of more complex organic molecules. So far, the
observed chemical complexity in disks has been limited due to freeze out of
molecules onto grains in the bulk of the cold outer disk. Complex molecules can
be studied more directly in transitional disks with large inner holes, as these
have a higher potential of detection, through UV heating of the outer disk and
the directly exposed midplane at the wall. We use Atacama Large
Millimeter/submillimeter Array (ALMA) Band 9 (~680 GHz) line data of the
transitional disk Oph IRS 48, previously shown to have a large dust trap, to
search for complex molecules in regions where planetesimals are forming. We
report the detection of the H2CO 9(1,8)-8(1,7) line at 674 GHz, which is
spatially resolved as a semi-ring at ~60 AU radius centered south from the
star. The inferred H2CO abundance is ~10^{-8} derived by combining a physical
disk model of the source with a non-LTE excitation calculation. Upper limits
for CH3OH lines in the same disk give an abundance ratio H2CO/CH3OH>0.3, which
points to both ice formation and gas-phase routes playing a role in the H2CO
production. Upper limits on the abundances of H13CO+, CN and several other
molecules in the disk are also derived and found to be consistent with full
chemical models. The detection of the H2CO line demonstrates the start of
complex organic molecules in a planet-forming disk. Future ALMA observations
should be able to push down the abundance detection limits of other molecules
by 1-2 orders of magnitude and test chemical models of organic molecules in
(transitional) disks.


title: The identification of glueballs - further tests

abstract:
  The indirect evidence for gluonic objects in gluon jets is recalled, more
accurate tests at the LHC are possible. Estimates of gluonic and quarkonic
components of scalar mesons are presented, which could be improved by further
studies, in particular of B and B_s decays. The results are consistent with the
scalar glueball mixing into f_0(500) and f_0(1500). The study of symmetry
relations for 2-body decay rates of charmonium \chi_c is suggested as crucial
test in the identification of q\bar q multiplets and glueballs. Further related
results are discussed in the recent review \cite{Ochs:2013gi}.


title: Scaling laws and sum rules for the B-mode polarization

abstract:
  The formation of the microwave background polarization anisotropies is
investigated when the stochastic Faraday rate is stationary, random and
Markovian. The scaling properties of the polarization power spectra and of
their nonlinear combinations are scrutinized as a function of the comoving
frequency. It is argued that each frequency channel of a given experiment
measuring simultaneously the E-mode and the B-mode spectra can be analyzed in
this framework with the aim of testing the physical origin of the polarization
in a model-independent perspective.


title:
Conductance behavior with temperature and magnetic field in the
  disordered films of titanium nitride

abstract:
  We report in this paper the temperature and mangetic field dependence of the
conductance in the polycrystalline film of titanium nitride, before and after
heating at ambient conditions. The difference between the two films is the room
temperature sheet resistance which remains within 15 percent and both the films
show superconducting transition at lower temperatures. The zero field and the
high field data, respectively, corresponds to the superconducting and the
normal states. Both the films display Atshuler-Aronov zero bias anamoly in
their normal states, and the superconducting gap openeing up at low fields.
However the heated film has a smaller gap owing to more pronounced zero bias
suppression of the density of states. The normal states in both the films are
similar to the quasi-2d-disordered metal and its behavior is studied with
temperature. Our data suggests that the zero bias anamoly suppresses the
superconducting gap with increase in the disorder.


title:
Quantum Mechanics from Newton's Second Law and the Canonical Commutation
  Relation [X,P]=i

abstract:
  Despite the fact that it has been known since the time of Heisenberg that
quantum operators obey a quantum version of Newton's laws, students are often
told that derivations of quantum mechanics must necessarily follow from the
Hamiltonian or Lagrangian formulations of mechanics. Here, we first derive the
existing Heisenberg equations of motion from Newton's laws and the uncertainty
principle using only the equations $F=\frac{dP}{dt}$, $P=m\frac{dV}{dt}$, and
$\left[X,P\right]=i$. Then, a new expression for the propagator is derived that
makes a connection between time evolution in quantum mechanics and the motion
of a classical particle under Newton's laws. The propagator is solved for three
cases where an exact solution is possible 1) the free particle 2) the harmonic
oscillator 3) a constant force, or linear potential in the standard
interpretation. Such a picture may be useful for students as they make the
transition from classical to quantum mechanics and help solidify the
equivalence of the Hamiltonian, Lagrangian, and Newtonian formulations of
physics in their minds.


title: $\kappa$-Deformed Phase Space, Hopf Algebroid and Twisting

abstract:
  Hopf algebroid structures on the Weyl algebra (phase space) are presented. We
define the coproduct for the Weyl generators from Leibniz rule. The codomain of
the coproduct is modified in order to obtain an algebra structure. We use the
dual base to construct the target map and antipode. The notion of twist is
analyzed for $\kappa$-deformed phase space in Hopf algebroid setting. It is
outlined how the twist in the Hopf algebroid setting reproduces the full Hopf
algebra structure of $\kappa$-Poincar\'e algebra. Several examples of
realizations are worked out in details.


title: Asymptotics of higher order ospt-functions for overpartitions

abstract:
  In this paper we obtain asymptotic formulas for the positive crank and rank
moments for overpartitions. Moreover, we show that crank and rank moments are
asymptotically equal while the difference is asymptotically positive. This
indicates that there exist analogous higher ospt-functions for overpartitions,
which we define.


title: Nonzero $\theta_{13}$ and CP Violation from Broken $\mu-\tau$ Symmetry

abstract:
  Nonzero and relatively large of $\theta_{13}$ mixing angle has some
phenomenological consequences on neutrino physics beyond the standard model.
One of the consequences if the mixing angle $\theta_{13}\neq 0$ is the
possibility of the CP violation on the neutrino sector. In order to obtain
nonzero $\theta_{13}$ mixing angle, we break the neutrino mass matrix that obey
$\mu-\tau$ symmetry by introducing a complex parameter and determine the
Jarlskog invariant as a measure of CP violation existence. By using the
experimental data as input, we determine the Dirac phase $\delta$ as function
of mixing angle $\theta_{13}$


title:
Exploration via Structured Triangulation by a Multi-Robot System with
  Bearing-Only Low-Resolution Sensors

abstract:
  This paper presents a distributed approach for exploring and triangulating an
unknown region using a multi- robot system. The objective is to produce a
covering of an unknown workspace by a fixed number of robots such that the
covered region is maximized, solving the Maximum Area Triangulation Problem
(MATP). The resulting triangulation is a physical data structure that is a
compact representation of the workspace; it contains distributed knowledge of
each triangle, adjacent triangles, and the dual graph of the workspace.
Algorithms can store information in this physical data structure, such as a
routing table for robot navigation Our algorithm builds a triangulation in a
closed environment, starting from a single location. It provides coverage with
a breadth-first search pattern and completeness guarantees. We show the
computational and communication requirements to build and maintain the
triangulation and its dual graph are small. Finally, we present a physical
navigation algorithm that uses the dual graph, and show that the resulting path
lengths are within a constant factor of the shortest-path Euclidean distance.
We validate our theoretical results with experiments on triangulating a region
with a system of low-cost robots. Analysis of the resulting quality of the
triangulation shows that most of the triangles are of high quality, and cover a
large area. Implementation of the triangulation, dual graph, and navigation all
use communication messages of fixed size, and are a practical solution for
large populations of low-cost robots.


title: Finiteness results for subgroups of finite extensions

abstract:
  We discuss in the context of finite extensions two classical theorems of
Takahasi and Howson on subgroups of free groups. We provide bounds for the rank
of the intersection of subgroups within classes of groups such as virtually
free groups, virtually nilpotent groups or fundamental groups of finite graphs
of groups with virtually polycyclic vertex groups and finite edge groups. As an
application of our generalization of Takahasi's Theorem, we provide an uniform
bound for the rank of the periodic subgroup of any endomorphism of the
fundamental group of a given finite graph of groups with finitely generated
virtually nilpotent vertex groups and finite edge groups.


title: Customizable Contraction Hierarchies

abstract:
  We consider the problem of quickly computing shortest paths in weighted
graphs given auxiliary data derived in an expensive preprocessing phase. By
adding a fast weight-customization phase, we extend Contraction Hierarchies by
Geisberger et al to support the three-phase workflow introduced by Delling et
al. Our Customizable Contraction Hierarchies use nested dissection orders as
suggested by Bauer et al. We provide an in-depth experimental analysis on large
road and game maps that clearly shows that Customizable Contraction Hierarchies
are a very practicable solution in scenarios where edge weights often change.


title: The Fermi Bubbles Revisited

abstract:
  We analyze 60 months of all sky data from the Fermi-LAT. The Fermi Bubble
structures discovered previously are clearly revealed by our analysis. With
more data and, consequently, better statistics we can now divide each bubble
into constant longitude slices to investigate their gross $\gamma$-ray spectral
morphology. While the detailed spectral behaviour of each slice derived within
our analysis is somewhat dependent on the assumed background model, we find,
robustly, a relative deficit of the flux at low energies (i.e., hardening)
towards the top of the South Bubble. In neither Bubble does the spectrum soften
with longitude. The morphology of the Fermi Bubbles is also revealed to be
energy dependent: at high energies they are more extended. We conclude from the
gamma-ray spectrum at high latitudes that a low energy break in the parent
cosmic ray population is required in both leptonic and hadronic models. We
briefly discuss possible leptonic and hadronic interpretation of this
phenomenology.


title:
A generalization of the Entropy Power Inequality to Bosonic Quantum
  Systems

abstract:
  In most communication schemes information is transmitted via travelling modes
of electromagnetic radiation. These modes are unavoidably subject to
environmental noise along any physical transmission medium and the quality of
the communication channel strongly depends on the minimum noise achievable at
the output. For classical signals such noise can be rigorously quantified in
terms of the associated Shannon entropy and it is subject to a fundamental
lower bound called entropy power inequality. Electromagnetic fields are however
quantum mechanical systems and then, especially in low intensity signals, the
quantum nature of the information carrier cannot be neglected and many
important results derived within classical information theory require
non-trivial extensions to the quantum regime. Here we prove one possible
generalization of the Entropy Power Inequality to quantum bosonic systems. The
impact of this inequality in quantum information theory is potentially large
and some relevant implications are considered in this work.


title: Generators and relations of the graded algebra of modular forms

abstract:
  We give bounds on the degree of generators for the ideal of relations of the
graded algebras of modular forms with coefficients in $\mathbb{Q}$ over
congruence subgroups $\Gamma_0(N)$ for $N$ satisfying some congruence
conditions and for $\Gamma_1(N)$. We give similar bounds for the graded
$\mathbb{Z}[\frac{1}{N}]$-algebra of modular forms on $\Gamma_1(N)$ with
coefficients in $\mathbb{Z}[\frac{1}{N}]$. For a prime $p \geq 5$, we give a
lower bound on the highest weight appearing in a minimal list of generators for
$\Gamma_0(p)$, and we identify a set of generators for the graded algebra
$M(\Gamma_0(p),\mathbb{Z})$ of modular forms over $\Gamma_0(p)$ with
coefficients in $\mathbb{Z}$, showing that this weight is unbounded. We
generalize a result of Serre concerning congruences between modular forms over
$\Gamma_0(p)$ and $SL_2(\mathbb{Z})$, and use it to identify a set of
generators for $M(\Gamma_0(p),\mathbb{Z})$, and we state two conjectures
detailing further the structure of this algebra. Finally we provide
computations concerning the number of generators and relations for each of
these algebras, as well as computational evidence for these conjectures.


title: Isospin properties of electric dipole excitations in 48Ca

abstract:
  Two different experimental approaches were combined to study the electric
dipole strength in the doubly-magic nucleus 48Ca below the neutron threshold.
Real-photon scattering experiments using bremsstrahlung up to 9.9 MeV and
nearly mono-energetic linearly polarized photons with energies between 6.6 and
9.51 MeV provided strength distribution and parities, and an
(\alpha,\alpha'\gamma) experiment at E_{\alpha}=136 MeV gave cross sections for
an isoscalar probe. The unexpected difference observed in the dipole response
is compared to calculations using the first-order random-phase approximation
and points to an energy-dependent isospin character. A strong isoscalar state
at 7.6 MeV was identified for the first time supporting a recent theoretical
prediction.


title: Spectroscopy of the inner companion of the pulsar PSR J0337+1715

abstract:
  The hierarchical triple system PSR J0337+1715 offers an unprecedented
laboratory to study secular evolution of interacting systems and to explore the
complicated mass-transfer history that forms millisecond pulsars and
helium-core white dwarfs. The latter in particular, however, requires knowledge
of the properties of the individual components of the system. Here we present
precise optical spectroscopy of the inner companion in the PSR J0337+1715
system. We confirm it as a hot, low-gravity DA white dwarf with
Teff=15,800+/-100 K and log(g)=5.82+/-0.05. We also measure an inner mass ratio
of 0.1364+/-0.0015, entirely consistent with that inferred from pulsar timing,
and a systemic radial velocity of 29.7+/-0.3 km/s. Combined with the mass
(0.19751 Msun) determined from pulsar timing, our measurement of the surface
gravity implies a radius of 0.091+/-0.005 Rsun; combined further with the
effective temperature and extinction, the photometry implies a distance of
1300+/-80 pc. The high temperature of the companion is somewhat puzzling: with
current models, it likely requires a recent period of unstable hydrogen
burning, and suggests a surprisingly short lifetime for objects at this phase
in their evolution. We discuss the implications of these measurements in the
context of understanding the PSR J0337+1715 system, as well as of low-mass
white dwarfs in general.


title: Curved homotopy coalgebras

abstract:
  We describe the category of homotopy coalgebras, concentrating on properties
of relatively cofree homotopy coalgebras, morphisms and coderivations from an
ordinary coalgebra to a relatively cofree homotopy coalgebra, morphisms and
coderivations between coalgebras of latter type. Cobar- and bar-constructions
between counit-complemented curved coalgebras, unit-complemented curved
algebras and curved homotopy coalgebras are described. Using twisting cochains
an adjunction between cobar- and bar-constructions is derived under additional
assumptions.


title: The Picard Scheme

abstract:
  This article introduces, informally, the substance and the spirit of
Grothendieck's theory of the Picard scheme, highlighting its elegant
simplicity, natural generality, and ingenious originality against the larger
historical record.


title: Minimum Price in Search Model

abstract:
  This paper investigates the effects of a low bound price. To do so, a popular
and empirically proven model (Stahl (89') \cite{Stahl89}) is used. The model is
extended to include an exogenously given bound on prices sellers can offer,
excluding prices below such bound. The finding are rather surprising - when the
bound is set sufficiently high expected price offered (EPO) by sellers drops
significantly. The result seem to be robust in the parameters of the model, and
driven by the information provided to consumers by such legislation step: when
the limitation is set at sufficiently high levels all consumers anticipate the
bound price, and searchers reject any price above it. As a result sellers offer
the bound price as a pure strategy.


title:
Crystal graphs, Tokuyama's theorem, and the Gindikin--Karpelevic formula
  for G_2

abstract:
  We conjecture a deformation of the Weyl character formula for type G_2 in the
spirit of Tokuyama's formula for type A. Using our conjecture we prove a
combinatorial version of the Gindikin--Karpelevic formula for G_2, in the
spirit of Bump--Nakasuji's formula for type A.


title: Bots vs. Wikipedians, Anons vs. Logged-Ins

abstract:
  Wikipedia is a global crowdsourced encyclopedia that at time of writing is
available in 287 languages. Wikidata is a likewise global crowdsourced
knowledge base that provides shared facts to be used by Wikipedias. In the
context of this research, we have developed an application and an underlying
Application Programming Interface (API) capable of monitoring realtime edit
activity of all language versions of Wikipedia and Wikidata. This application
allows us to easily analyze edits in order to answer questions such as "Bots
vs. Wikipedians, who edits more?", "Which is the most anonymously edited
Wikipedia?", or "Who are the bots and what do they edit?". To the best of our
knowledge, this is the first time such an analysis could be done in realtime
for Wikidata and for really all Wikipedias--large and small. Our application is
available publicly online at the URL http://wikipedia-edits.herokuapp.com/, its
code has been open-sourced under the Apache 2.0 license.


title:
\pi N TDAs from charmonium production in association with a forward pion
  at PANDA

abstract:
  Charmonium production in association with a forward or backward pion in
nucleon-antinucleon annihilation is one of the most promising reaction to
access nucleon-to-pion transition distribution amplitudes (TDAs) at PANDA. We
briefly review the description of this reaction in terms of \pi N TDAs within
the collinear factorization approach and present the first results of dedicated
feasibility studies for the PANDA experimental setup.


title: Critical sets of proper holomorphic mappings

abstract:
  It is shown that if a proper holomorphic map $f: \mathbb C^n \to \mathbb
C^N$, $1<n\le N$, sends a pseudoconvex real analytic hypersurface of finite
type into another such hypersurface, then any $n-1$ dimensional component of
the critical locus of $f$ intersects both sides of $M$. We apply this result to
the problem of boundary regularity of proper holomorphic mappings between
bounded domains in $\mathbb C^n$.


title:
Investigations on the electrical current-voltage response in protein
  light receptors

abstract:
  We report a theoretical/computational approach for modeling the
current-voltage characteristics of sensing proteins. The modeling is applied to
a couple of transmembrane proteins, bacteriorhodopsin and proteorhodopsin,
sensitive to visible light and promising biomaterials for the development of a
new generation of photo-transducers. The agreement between theory and
experiments sheds new light on the microscopic interpretation of charge
transfer in proteins and biological materials in general.


title: Non-equilibrium work relation beyond Boltzmann-Gibbs distribution

abstract:
  The presence of multiplicative noise can alter measurements of forces acting
on nanoscopic objects. Taking into account of multiplicative noise, we derive a
series of non-equilibrium thermodynamical equalities as generalization of the
Jarzynski equality, the detailed fluctuation theorem and the Hatano-Sasa's
relation. Our result demonstrates that the Jarzynski equality and the detailed
fluctuation theorem remains valid only for systems with the Boltzmann-Gibbs
distribution at the equilibrium state, but the Hatano-Sasa's relation is robust
with respect to the ambiguity on multiplicative noise.


title: A covariant model for the $\gamma^\ast N \to N^\ast(1520)$ reaction

abstract:
  We apply the covariant spectator quark model to the study of the
electromagnetic structure of the $N^\ast(1520)$ state ($J^{P}= \frac{3}{2}^-$),
an important resonance from the second resonance region in both spacelike and
timelike regimes. The contributions from the valence quark effects are
calculated for the $\gamma^\ast N \to N^\ast(1520)$ helicity amplitudes. The
results are used to parametrize the meson cloud dominant at low $Q^2$.


title: Heavy Quark Production in Ultra High Energy Cosmic Ray Interactions

abstract:
  In this paper we present a comprehensive study of the heavy quark production
in ultra high energy cosmic ray interactions in the atmosphere considering that
the primary cosmic ray can be either a photon, neutrino or a proton. The
analysis is performed using a unified framework -- the dipole formalism --- and
the saturation effects, associated to the physical process of parton
recombination, are taken into account. We demonstrate that the contribution of
heavy quarks for cosmic ray interactions is in general non-negligible and can
be dominant depending of the process considered. Moreover, our results indicate
that new dynamical mechanisms should be included in order to obtain reliable
predictions for the heavy quark production in $pp$ collisions at ultra high
cosmic ray energies.


title:
Stochastic thermodynamics of bipartite systems: transfer entropy
  inequalities and a Maxwell's demon interpretation

abstract:
  We consider the stationary state of a Markov process on a bipartite system
from the perspective of stochastic thermodynamics. One subsystem is used to
extract work from a heat bath while being affected by the second subsystem. We
show that the latter allows for a transparent and thermodynamically consistent
interpretation of a Maxwell's demon. Moreover, we obtain an integral
fluctuation theorem involving the transfer entropy from one subsystem to the
other. Comparing three different inequalities, we show that the entropy
decrease of the first subsystem provides a tighter bound on the rate of
extracted work than both the rate of transfer entropy from this subsystem to
the demon and the heat dissipated through the dynamics of the demon. The latter
two rates cannot be ordered by an inequality as shown with the illustrative
example of a four state system.


title: Multidiscipinary Optimization For Gas Turbines Design

abstract:
  State-of-the-art aeronautic Low Pressure gas Turbines (LPTs) are already
characterized by high quality standards, thus they offer very narrow margins of
improvement. Typical design process starts with a Concept Design (CD) phase,
defined using mean-line 1D and other low-order tools, and evolves through a
Preliminary Design (PD) phase, which allows the geometric definition in
details. In this framework, multidisciplinary optimization is the only way to
properly handle the complicated peculiarities of the design. The authors
present different strategies and algorithms that have been implemented
exploiting the PD phase as a real-like design benchmark to illustrate results.
The purpose of this work is to describe the optimization techniques, their
settings and how to implement them effectively in a multidisciplinary
environment. Starting from a basic gradient method and a semi-random second
order method, the authors have introduced an Artificial Bee Colony-like
optimizer, a multi-objective Genetic Diversity Evolutionary Algorithm [1] and a
multi-objective response surface approach based on Artificial Neural Network,
parallelizing and customizing them for the gas turbine study. Moreover, speedup
and improvement arrangements are embedded in different hybrid strategies with
the aim at finding the best solutions for different kind of problems that arise
in this field.


title: Generalized Dehn-Sommerville relations for hypergraphs

abstract:
  The generalized Dehn-Sommerville relations determine the odd subalgebra of
the combinatorial Hopf algebra. We introduce a class of eulerian hypergraphs
that satisfy the generalized Dehn-Sommerville relations for the combinatorial
Hopf algebra of hypergraphs. We characterize a wide class of eulerian
hypergraphs according to the combinatorics of underlying clutters. The
analogous results hold for simplicial complexes by the isomorphism which is
induced from the correspondence of clutters and simplicial complexes.


title:
A high-reproducibility and high-accuracy method for automated topic
  classification

abstract:
  Much of human knowledge sits in large databases of unstructured text.
Leveraging this knowledge requires algorithms that extract and record metadata
on unstructured text documents. Assigning topics to documents will enable
intelligent search, statistical characterization, and meaningful
classification. Latent Dirichlet allocation (LDA) is the state-of-the-art in
topic classification. Here, we perform a systematic theoretical and numerical
analysis that demonstrates that current optimization techniques for LDA often
yield results which are not accurate in inferring the most suitable model
parameters. Adapting approaches for community detection in networks, we propose
a new algorithm which displays high-reproducibility and high-accuracy, and also
has high computational efficiency. We apply it to a large set of documents in
the English Wikipedia and reveal its hierarchical structure. Our algorithm
promises to make "big data" text analysis systems more reliable.


title:
A Bound on the Expected Optimality of Random Feasible Solutions to
  Combinatorial Optimization Problems

abstract:
  This paper investigates and bounds the expected solution quality of
combinatorial optimization problems when feasible solutions are chosen at
random. Loose general bounds are discovered, as well as families of
combinatorial optimization problems for which random feasible solutions are
expected to be a constant factor of optimal. One implication of this result is
that, for graphical problems, if the average edge weight in a feasible solution
is sufficiently small, then any randomly chosen feasible solution to the
problem will be a constant factor of optimal. For example, under certain
well-defined circumstances, the expected constant of approximation of a
randomly chosen feasible solution to the Steiner network problem is bounded
above by 3. Empirical analysis supports these bounds and actually suggest that
they might be tightened.


title:
Differentiable conjugacy for groups of area preserving circle
  diffeomorphisms

abstract:
  We study groups of circle diffeomorphisms whose action on the cylinder
$\mathcal C=\mathbb S^1\times \mathbb S^1\setminus \Delta$ preserves a volume
form. We first show that such a group is topologically conjugate to a subgroup
of $\rm{PSL}(2,\mathbb R)$, then discuss the existence of a differentiable
conjugacy.


title: Some invariant biorthogonal sets with an application to coherent states

abstract:
  We show how to construct, out of a certain basis invariant under the action
of one or more unitary operators, a second biorthogonal set with similar
properties. In particular, we discuss conditions for this new set to be also a
basis of the Hilbert space, and we apply the procedure to coherent states. We
conclude the paper considering a simple application of our construction to
pseudo-hermitian quantum mechanics.


title: First order phase transitions in polymerized phantom membranes

abstract:
  The crumpled-to-flat phase transition that occurs in D-dimensional
polymerized phantom membranes embedded in a d-dimensional space is investigated
nonperturbatively using a field expansion up to order eight in powers of the
order parameter. We get the critical dimension dcr(D) that separates a second
order region from a first order one everywhere between D=4 and D=2. Our
approach strongly suggests that the phase transitions that take place in
physical membranes are of first order in agreement with most recent numerical
simulations.


title: Cohomology and Hodge Theory on Symplectic Manifolds: III

abstract:
  We introduce filtered cohomologies of differential forms on symplectic
manifolds. They generalize and include the cohomologies discussed in Paper I
and II as a subset. The filtered cohomologies are finite-dimensional and can be
associated with differential elliptic complexes. Algebraically, we show that
the filtered cohomologies give a two-sided resolution of Lefschetz maps, and
thereby, they are directly related to the kernels and cokernels of the
Lefschetz maps. We also introduce a novel, non-associative product operation on
differential forms for symplectic manifolds. This product generates an
A-infinity algebra structure on forms that underlies the filtered cohomologies
and gives them a ring structure. As an application, we demonstrate how the ring
structure of the filtered cohomologies can distinguish different symplectic
four-manifolds in the context of a circle times a fibered three-manifold.


title:
Parity-Time Symmetry Breaking beyond One Dimension: The Role of
  Degeneracy

abstract:
  We consider the role of degeneracy in Parity-Time (PT) symmetry breaking for
non-hermitian wave equations beyond one dimension. We show that if the spectrum
is degenerate in the absence of T-breaking, and T is broken in a generic manner
(without preserving other discrete symmetries), then the standard PT-symmetry
breaking transition does not occur, meaning that the spectrum is complex even
for infinitesimal strength of gain and loss. However the realness of the entire
spectrum can be preserved over a finite interval if additional discrete
symmetries X are imposed when T is broken, if X decouple all degenerate modes.
When this is true only for a subset of the degenerate spectrum, there can be a
partial PT transition in which this subset remains real over a finite interval
of T-breaking. If the spectrum has odd-degeneracy, a fraction of the degenerate
spectrum can remain in the symmetric phase even without imposing additional
discrete symmetries, and they are analogous to dark states in atomic physics.
These results are illustrated by the example of different T-breaking
perturbations of a uniform dielectric disk and sphere, and a group theoretical
analysis is given in the disk case. Finally, we show that multimode coupling is
capable of restoring the T-symmetric phase at finite T-breaking. We also
analyze these questions when the parity operator is replaced by another spatial
symmetry operator and find that the behavior can be qualitatively different.


title:
Defmod - Parallel multiphysics finite element code for modeling crustal
  deformation during the earthquake/rifting cycle

abstract:
  In this article, we present Defmod, an open source, fully unstructured, two
or three dimensional, parallel finite element code for modeling crustal
deformation over time scales ranging from milliseconds to thousands of years.
Unlike existing public domain numerical codes, Defmod can simulate deformation
due to all major processes that make up the earthquake/rifting cycle, in
non-homogeneous media. Specifically, it can be used to model deformation due to
dynamic and quasistatic processes such as co-seismic slip or dike intrusion(s),
poroelastic rebound due to fluid flow and post-seismic or post-rifting
viscoelastic relaxation. It can also be used to model deformation due to
processes such as post-glacial rebound, hydrological (un)loading, injection
and/or withdrawal of fluids from subsurface reservoirs etc. Defmod is written
in Fortran 95 and uses PETSc's parallel sparse data structures and implicit
solvers. Problems can be solved using (stabilized) linear triangular,
quadrilateral, tetrahedral or hexahedral elements on shared or distributed
memory machines with hundreds or even thousands of processor cores. In the
current version of the code, prescribed loading is supported. Results are
written in ASCII VTK format for easy visualization. The source code is released
under the terms of GNU General Public License (v3.0) and is freely available
from https://bitbucket.org/stali/defmod/.


title:
Mathematical model of alternative mechanism of telomere length
  maintenance

abstract:
  Biopolymer length regulation is a complex process that involves a large
number of subprocesses acting simultaneously across multiple spatial and
temporal scales. An illustrative example important for genomic stability is the
length regulation of telomeres---nucleo-protein structures at the ends of
linear chromosomes. Maintenance of telomeres is often facilitated by the enzyme
telomerase but, particularly in telomerase-free systems, the maintenance of
chromosomal termini depends on alternative lengthening of telomeres (ALT)
mechanisms mediated by recombination. Various linear and circular DNA
structures were identified to participate in ALT, however, dynamics of the
whole process is still poorly understood. We propose a chemical kinetics model
of ALT with kinetic rates systematically derived from the biophysics of DNA
diffusion and looping. The reaction system is reduced to a
coagulation-fragmentation system by quasi-steady state approximation. The
detailed treatment of kinetic rates yields explicit formulae for expected size
distributions of telomeres that demonstrate the key role played by the
J-factor, a quantitative measure of bending of polymers. The results are in
agreement with experimental data and point out interesting phenomena: an
appearance of very long telomeric circles if the total telomere density exceeds
a critical value (excess mass) and a nonlinear response of the telomere size
distributions to the amount of telomeric DNA in the system. The results can be
of general importance for understanding dynamics of telomeres in
telomerase-independent systems as this mode of telomere maintenance is similar
to the situation in tumor cells lacking telomerase activity. Furthermore, due
to its universality, the model may also serve as a prototype of an interaction
between linear and circular DNA structures in various settings.


title: Analysis of $f(R)$ Theory Corresponding to NADE and NHDE

abstract:
  We develop the connection of $f(R)$ theory with new agegraphic and
holographic dark energy models. The function $f(R)$ is reconstructed, regarding
the $f(R)$ theory as an effective description for these dark energy models. We
show the future evolution of $f$ and conclude that these functions represent
distinct pictures of cosmological eras. The cosmological parameters such as
equation of state parameter, deceleration parameter, statefinder diagnostic and
$\omega-\omega'$ analysis are investigated which assure the evolutionary
paradigm of $f$.


title:
SurvRegCensCov: Weibull Regression for a Right-Censored Endpoint with a
  Censored Covariate

abstract:
  Biomarker data is often subject to limits of quantification and/or limits of
detection. Statistically, this corresponds to left- or interval-censoring. To
be able to associate a censored time-to-event endpoint to a biomarker
covariate, the R package SurvRegCensCov provides software for Weibull
regression for a right-censored endpoint, one interval-censored, and an
arbitrary number of non-censored covariates. Furthermore, the package provides
functions to estimate canonical parameters from censored samples based on
several distributional assumptions, and a function to switch between different
parametrizations used in R for Weibull regression. We illustrate the new
software by applying it to assess Prentice's criteria for surrogacy in data
simulated from a randomized clinical registration trial.


title: 2-adic Stirling functions and their zeros

abstract:
  Let $P_n(x)=\frac1{n!}\sum\binom n{2i+1}(2i+1)^x$. This extends to a
continuous function on the 2-adic integers, the $n$th 2-adic partial Stirling
function. We show that $(-1)^{n+1}P_n$ is the only 2-adically continuous
approximation to $S(x,n)$, the Stirling number of the second kind. We present
extensive information about the zeros of $P_n$, for which there are many
interesting patterns. We prove that if $e\ge2$ and $2^e+1\le n\le 2^e+4$, then
$P_n$ has exactly $2^{e-1}$ zeros, one in each mod $2^{e-1}$ congruence. We
study the relationship between the zeros of $P_{2^e+\Delta}$ and $P_\Delta$,
for $1\le\Delta\le 2^e$, and the convergence of $P_{2^e+\Delta}(x)$ as
$e\to\infty$.


title:
Splitting of a nondegenerate phonon mode in PrFe3(BO3)4: 4f
  crystal-field level between TO and LO phonon frequencies

abstract:
  A new effect originating from the crystal-field-excitation - phonon coupling
was observed (in the far infrared spectra of a multiferroic PrFe3(BO3)4). The
reststrahlen band corresponding to the A2 symmetry nondegenerate phonon mode
near 50 cm-1 (1.5 THz) splits into two bands at about 100 K, well above TN = 32
K. These bands shift and narrow progressively with further lowering the
temperature, demonstrating pronounced peculiarities at TN. The observed effects
were explained by an interaction of the A2 phonon mode with the 4f
crystal-field electronic excitation of Pr3+ whose frequency falls into the TO -
LO frequency region of the phonon mode. Inversion of the TO and LO frequencies
for the electronic excitation and a formation of coupled electron-phonon modes
are discussed. Fitting of the TO frequency vs temperature experimental plots by
theoretical curves revealed the value 14.6 cm-1 for the electron-phonon
coupling constant.


title:
Efficacy of the DFT+U formalism for modeling hole polarons in perovskite
  oxides

abstract:
  We investigate the formation of self-trapped holes (STH) in three
prototypical perovskites (SrTiO3, BaTiO3, PbTiO3) using a combination of
density functional theory (DFT) calculations with local potentials and hybrid
functionals. First we construct a local correction potential for polaronic
configurations in SrTiO3 that is applied via the DFT+U method and matches the
forces from hybrid calculations. We then use the DFT+U potential to search the
configuration space and locate the lowest energy STH configuration. It is
demonstrated that both the DFT+U potential and the hybrid functional yield a
piece-wise linear dependence of the total energy on the occupation of the STH
level suggesting that self-interaction effects have been properly removed. The
DFT+U model is found to be transferable to BaTiO3 and PbTiO3, and formation
energies from DFT+U and hybrid calculations are in close agreement for all
three materials. STH formation is found to be energetically favorable in SrTiO3
and BaTiO3 but not in PbTiO3, which can be rationalized by considering the
alignment of the valence band edges on an absolute energy scale. In the case of
PbTiO3 the strong coupling between Pb 6s and O 2p states lifts the valence band
minimum (VBM) compared to SrTiO3 and BaTiO3. This reduces the separation
between VBM and STH level and renders the STH configuration metastable with
respect to delocalization (band hole state). We expect that the present
approach can be adapted to study STH formation also oxides with different
crystal structures and chemical composition.


title:
The Effect of Magnetic Fields, Temperature and Current on the
  Resistivity of Bi-2223 High Temperature Superconductors

abstract:
  The electrical resistivity of polycrystalline Bi2Sr2Ca2Cu3O10-x (Bi-2223) was
measured vs. applied magnetic fields up to 0.45 T, applied currents up to 1 A,
and temperature from liquid nitrogen temperature (LN2) to room temperature. In
the lowest temperature region, the only truly zero resistivity was observed
when the magnetic field was zero; otherwise, a quadratic dependence on the
magnetic field occurred. Hysteresis was noted at the higher currents. Current
vs. voltage curves in this region revealed a non-ohmic resistivity. In the
transition region to the mixed state, indications of negative resistivity and
suggestions of a phase change were observed. Arrhenius plots yielded activation
energies of around 0.05 eV/molecule. In the mixed state region up to the
transition temperature of ~110K, analysis implied that 4 superconducting
quantum states exist and that they are cooperatively filled by the
superconducting charge carriers. The occupation of the superconducting quantum
states is negatively affected by the applied magnetic field and by the applied
current. No effect on the polarity or direction of the magnetic field with
respect to the direction of the current was observed.


title: The cosmic ray electron and positron spectra measured by AMS-02

abstract:
  The AMS-02 detector is operating on the International Space Station since May
2011. More than 30 billion events have been collected by the instrument in the
first two years of data taking. A precision measurement of the positron
fraction and of the positron flux in primary cosmic rays up to 350 GeV, of the
electron flux up to 500 GeV and of the combined electron plus positron flux up
to 700 GeV are presented. The separate and combined electron and positron
fluxes are preliminary and represent work in progress. Systematic uncertainties
must still be investigated further.


title: Born-Oppenheimer Approximation for the XYZ Mesons

abstract:
  Many of the XYZ mesons discovered in the last decade can be identified as
bound states in Born-Oppenheimer (B-O) potentials for a heavy quark and
antiquark. They include quarkonium hybrids, which are bound states in excited
flavor-singlet B-O potentials, and quarkonium tetraquarks, which are bound
states in flavor-nonsinglet B-O potentials. We present simple parameterizations
of the deepest flavor-singlet B-O potentials. We infer the deepest
flavor-nonsinglet B-O potentials from lattice QCD calculations of static
adjoint mesons. Selection rules for hadronic transitions are used to identify
XYZ mesons that are candidates for ground-state energy levels in the B-O
potentials for charmonium hybrids and tetraquarks. The energies of the
lowest-energy charmonium hybrids are predicted by using the results of lattice
QCD calculations to calculate the energy splittings between the ground states
of different B-O potentials and using the Schroedinger equation to determine
the splittings between energy levels within a B-O potential.


title: Coordinate-space approach to vacuum polarization

abstract:
  The vacuum-polarization correction for bound electrons or muons is examined.
The objective is to formulate a framework for calculating the correction from
bound-state quantum electrodynamics entirely in coordinate space, including the
Uehling potential which is usually isolated and treated separately.
Pauli-Villars regularization is applied to the coordinate-space calculation and
the most singular terms are shown to be eliminated, leaving the physical
correction after charge renormalization. The conventional derivation of the
Uehling potential in momentum space is reviewed and compared to the
coordinate-space derivation.


title:
Non-computable impressions of computable external rays of quadratic
  polynomials

abstract:
  We discuss computability of impressions of prime ends of compact sets. In
particular, we construct quadratic Julia sets which possess explicitly
described non-computable impressions.


title: Representations of ideals in Polish groups and in Banach spaces

abstract:
  We investigate ideals of the form $\{A \subseteq \omega\colon \sum_{n\in A}
x_n$ is unconditionally convergent $\}$, where $(x_n)_{n\in\omega}$ is a
sequence in a Polish group or in a Banach space. If an ideal on $\omega$ can be
seen in this form for some sequence in $X$, then we say that it is
representable in $X$.
  After numerous examples we show the following theorems: (1) An ideal is
representable in a Polish Abelian group iff it is an analytic P-ideal. (2) An
ideal is representable in a Banach space iff it is a non-pathological analytic
P-ideal.
  We focus on the family of ideals representable in $c_0$. We prove that the
trace of the null ideal, Farah's ideal, and Tsirelson ideals are not
representable in $c_0$, and that a tall $F_\sigma$ P-ideal is representable in
$c_0$ iff it is a summable ideal. Also, we provide an example of a peculiar
ideal which is representable in $\ell_1$ but not in $\mathbb{R}$.
  Finally, we summarize some open problems of this topic.


title: The p-spectral radius of k-partite and k-chromatic uniform hypergraphs

abstract:
  We characterize the r-graph with maximal p-spectral radius among the
k-partite r-graphs of order n, and the 3-graph with maximal p-spectral radius
among the k-chromatic 3-graphs of order n.


title: Another product for a Borcherds form

abstract:
  In his celebrated 1998 Inventiones paper, Borcherds constructed meromorphic
automorphic forms Psi(F) for arithmetic subgroups associated to even integral
lattices M of signature (n,2). The input to his construction is a vector valued
weakly holomorphic modular form F of weight 1 - n/2, and the resulting
Borcherds form has an explicit divisor on the arithmetic quotient X = Gamma_M\
D. Most remarkably, in the neighborhood of each cusp (= rational point boundary
component), there is a beautiful product formula for Psi(F), reminiscent of the
classical product formula for the Dedekind eta-function. In this paper, we
describe an analogous product formula for Psi(F) in the neighborhood of each
1-dimensional rational boundary component. This formula, which, like that of
Borcherds, is obtained through the calculation of a regularized theta integral,
reveals the behavior of Psi(F) on a (partial) smooth compactification of X.
  Information about Fourier-Jacobi coefficients is added to this revised
version.


title:
Including screening in van-der-Waals corrected DFT calculations. The
  case of atoms and small molecules physisorbed on graphene

abstract:
  The DFT/vdW-QHO-WF method, recently developed to include the van der Waals
(vdW) interactions in approximated Density Functional Theory (DFT) by combining
the Quantum Harmonic Oscillator model with the Maximally Localized Wannier
Function technique, is applied to the cases of atoms and small molecules (X=Ar,
CO, H$_2$, H$_2$O) weakly interacting with benzene and with the ideal planar
graphene surface. Comparison is also presented with the results obtained by
other DFT vdW-corrected schemes, including PBE+D, vdW-DF, vdW-DF2, rVV10, and
by the simpler Local Density Approximation (LDA) and semilocal Generalized
Gradient Approximation (GGA) approaches. While for the X-benzene systems all
the considered vdW-corrected schemes perform reasonably well, it turns out that
an accurate description of the X-graphene interaction requires a proper
treatment of many-body contributions and of short-range screening effects, as
demonstrated by adopting an improved version of the DFT/vdW-QHO-WF method. We
also comment on the widespread attitude of relying on LDA to get a rough
description of weakly interacting systems.


title: Bounding the top Yukawa with Higgs-associated single-top production

abstract:
  After the discovery of the 125 GeV scalar boson with gauge properties similar
to the Standard Model Higgs, the search for beyond the SM interactions will
focus on studying the discovered particles' coupling properties more precisely
and shedding light on the relation of fermion masses with the electroweak
vacuum. The large mass of the top quark and the SM-predicted order one top
Yukawa coupling is a natural candidate for BSM physics, though experimentally
challenging to constrain. In this paper, we argue that investigating angular
correlations in $pp\to tHj$ production provides an excellent handle to
constrain the top Yukawa coupling $y_t$ via direct measurements, even when we
focus on rare exclusive final states. We perform a hadron-level analysis and
show that we may expect to constrain $y_t\gtrsim 0.5\, y_t^{\text{SM}}$ at
95%-99% confidence level at the high luminosity LHC using semi-leptonic top
decays and $H\to \gamma \gamma$ alone, by employing a two-channel measurement
approach.


title:
Stroemgren - near-infrared photometry of the Baade's Window. I. The
  bulge globular cluster NGC6528 and the surrounding field

abstract:
  We present Stroemgren-NIR photometry of NGC6528 and its surroundings in the
Baade's Window. uvby images were collected with EFOSC2@NTT, while NIR catalogs
are based on VIRCAM@VISTA and SOFI@NTT data. The matching with HST photometry
allowed us to obtain proper-motion-cleaned samples of cluster and bulge stars.
The huge color sensitivity of Stroemgren-NIR CMDs helped us in disentangling
age and metallicity effects. The RGB of NGC6528 is reproduced by scaled-solar
isochrones with solar abundance or alpha-enhanced isochrones with the same iron
content, and an age of t = 11+/-1 Gyr. These findings support literature age
estimates for NGC6528. We also performed a theoretical metallicity calibration
based on the Stroemgren index m1 and on visual-NIR colors for RGs, by adopting
scaled-solar and alpha-enhanced models. We applied the calibration to estimate
the metallicity of NGC6528, finding [Fe/H] = -0.04+/-0.02, with an intrinsic
dispersion of 0.27 dex (by averaging abundances based on the scaled-solar [m],
y - J and [m], y - K Metallicity-Index-Color relations), and of -0.11+/-0.01
(sig = 0.27 dex), by using the m1, y - J and m1, y - K relations. These
findings support the results of Zoccali et al. (2004) which give [Fe/H] =
-0.10+/-0.2, and a low alpha-enhancement, [alpha/Fe] = 0.1, and of Carretta et
al. (2001), that find [Fe/H] = 0.07+/-0.01, with [alpha/Fe] = 0.2. By applying
the scaled-solar MIC relations to Baade's window RGs, we find a metallicity
distribution extending from [Fe/H] ~ -1.0 to ~ 1 dex, with peaks at [Fe/H] ~
-0.2 and +0.55 ([m], y - J and [m], y - K relations), and [Fe/H] ~ -0.25 and
+0.4 (m1, y - J and m1, y - K relations). These findings are in good agreement
with the spectroscopic studies of Hill et al. (2011) for the Baade's window, of
Uttenthaler et al. (2012) for a region centered at (l,b) = (0, -10), and with
the results of the ARGOS survey (Ness et al. 2013a).


title: Estimation of quantum states by weak and projective measurements

abstract:
  We explore the possibility of using "weak" measurements to carry out quantum
state tomography. Given a certain fixed number of copies of identically
prepared states of a qubit, we simulate state tomography using weak as well as
projective measurements. Due to the collapse of the state after measurement, we
cannot re-use the state after a projective measurement. If the coupling
strength between the quantum system and the measurement device is made weaker,
the disturbance caused to the state can be lowered. This then allows us to
re-use the same member of the ensemble for further measurements and thus
extract more information from the system. However, this happens at the expense
of getting imprecise information from the first measurement. We simulate this
scheme for a single qubit and show that under certain circumstances, it can
outperform the projective measurement-based tomography scheme. This opens up
the possibility of new ways of extracting information from quantum ensembles.
We study the efficacy of this scheme for different coupling strengths.


title: Non-local gravity and dark energy

abstract:
  We discuss a nonlocal modification of gravity obtained adding a term $m^2
R\,\Box^{-2}R$ to the Einstein-Hilbert action. We find that the mass parameter
$m$ only affects the non-radiative sector of the theory, while the graviton
remains massless, there is no propagating ghost-like degree of freedom, no vDVZ
discontinuity, and no Vainshtein radius below which the theory becomes strongly
coupled. For $m={\cal O}(H_0)$ the theory therefore recovers all successes of
GR at solar system and lab scales, and only deviates from it at cosmological
scales. We examine the cosmological consequences of the model and we find that
it automatically generates a dynamical dark energy and a self-accelerating
evolution. After fixing our only free parameter $m$ so to reproduce the
observed value of the dark energy density today, we get a pure prediction for
the dark energy equation of state, $w_ {\rm DE}\simeq-1.14$. This value is
consistent with the existing data, and could also resolve the possible tension
between the Planck data and local measurements of the Hubble parameter.


title:
Combinatorial Interpretation of the Scalar Products of State Vectors of
  Integrable Models

abstract:
  The representation of the Bethe wave functions of certain integrable models
via the Schur functions allows to apply the well-developed theory of the
symmetric functions to the calculation of the thermal correlation functions.
The algebraic relations arising in the calculation of the scalar products and
the correlation functions are based on the Binet-Cauchy formula for the Schur
functions. We provide a combinatorial interpretation of the formula for the
scalar products of the Bethe state-vectors in terms of nests of the
self-avoiding lattice paths constituting the so-called watermelon
configurations. The interpretation proposed is, in its turn, related to the
enumeration of the boxed plane partitions.

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


title:
Example of an explicit function for confining classical Yang-Mills
  fields with quantum fluctuations in the path integral scheme

abstract:
  This article reports an explicit function form for confining classical
Yang-Mills vector potentials and quantum fluctuations around the classical
field. The classical vector potential, which is composed of a confining
localized function and an unlocalized function, satisfies the classical
Yang-Mills equation. The confining localized function contributes to the Wilson
loop, while the unlocalized function makes no contribution to this loop. The
confining linear potential between a heavy fermion and antifermion is due to
(1) the Lie algebra and (2) the form of the confining localized function which
has opposite signs at the positions of the particle and antiparticle along the
Wilson loop in the time direction. Some classical confining parts of vector
potentials also change sign on inversion of the coordinates of the axis
perpendicular to the axis joining the two particles. The localized parts of the
vector potentials are squeezed around the axis connecting the two particles,
and the string tension of the confining linear potential is derived. Quantum
fluctuations are formulated using a field expression in terms of local basis
functions in real spacetime. The quantum path integral gives the Coulomb
potential between the two particles in addition to the linear potential due to
the classical fields.


title: Cancer-driven dynamics of immune cells in a microfluidic environment

abstract:
  Scope of the present work is to frame into a rigorous, quantitative scaffold
- stemmed from stochastic process theory - two sets of experiments designed to
infer the spontaneous organization of leukocytes against cancer cells, namely
mice splenocytes vs. B16 mouse tumor cells, and embedded in an "ad hoc"
microfluidic environment developed on a LabOnChip technology. In the former,
splenocytes from knocked out (KO) mice engineered to silence the transcription
factor IRF-8, crucial for the development and function of several immune
populations, were used. In this case lymphocytes and cancer cells exhibited a
poor reciprocal exchange, resulting in the inability of coordinating or
mounting an effective immune response against melanoma. In the second class of
tests, wild type (WT) splenocytes were able to interact with and to coordinate
a response against the tumor cells through physical interaction. The
environment where cells moved was built of by two different chambers,
containing respectively melanoma cells and splenocytes, connected by capillary
migration channels allowing leucocytes to migrate from their chamber toward the
melanoma one. We collected and analyzed data on the motility of the cells and
found that the first ensemble of IRF-8 KO cells performed pure uncorrelated
random walks, while WT splenocytes were able to make singular drifted random
walks, that, averaged over the ensemble of cells, collapsed on a straight
ballistic motion for the system as a whole. At a finer level of investigation,
we found that IRF-8 KO splenocytes moved rather uniformly since their step
lengths were exponentially distributed, while WT counterpart displayed a
qualitatively broader motion as their step lengths along the direction of the
melanoma were log-normally distributed.


title: A Lower Bound for the Variance of Estimators for Nakagami m Distribution

abstract:
  Recently, we have proposed a maximum likelihood iterative algorithm for
estimation of the parameters of the Nakagami-m distribution. This technique
performs better than state of art estimation techniques for this distribution.
This could be of particular use in low data or block based estimation problems.
In these scenarios, the estimator should be able to give accurate estimates in
the mean square sense with less amounts of data. Also, the estimates should
improve with the increase in number of blocks received. In this paper, we see
through our simulations, that our proposal is well designed for such
requirements. Further, it is well known in the literature that an efficient
estimator does not exist for Nakagami-m distribution. In this paper, we derive
a theoretical expression for the variance of our proposed estimator. We find
that this expression clearly fits the experimental curve for the variance of
the proposed estimator. This expression is pretty close to the cramer-rao lower
bound(CRLB).


title: Fine-Grained Visual Categorization via Multi-stage Metric Learning

abstract:
  Fine-grained visual categorization (FGVC) is to categorize objects into
subordinate classes instead of basic classes. One major challenge in FGVC is
the co-occurrence of two issues: 1) many subordinate classes are highly
correlated and are difficult to distinguish, and 2) there exists the large
intra-class variation (e.g., due to object pose). This paper proposes to
explicitly address the above two issues via distance metric learning (DML). DML
addresses the first issue by learning an embedding so that data points from the
same class will be pulled together while those from different classes should be
pushed apart from each other; and it addresses the second issue by allowing the
flexibility that only a portion of the neighbors (not all data points) from the
same class need to be pulled together. However, feature representation of an
image is often high dimensional, and DML is known to have difficulty in dealing
with high dimensional feature vectors since it would require $\mathcal{O}(d^2)$
for storage and $\mathcal{O}(d^3)$ for optimization. To this end, we proposed a
multi-stage metric learning framework that divides the large-scale high
dimensional learning problem to a series of simple subproblems, achieving
$\mathcal{O}(d)$ computational complexity. The empirical study with FVGC
benchmark datasets verifies that our method is both effective and efficient
compared to the state-of-the-art FGVC approaches.


title: Modelling Load Balancing and Carrier Aggregation in Mobile Networks

abstract:
  In this paper, we study the performance of multicarrier mobile networks.
Specifically, we analyze the flow-level performance of two inter-carrier load
balancing schemes and the gain engendered by Carrier Aggregation (CA). CA is
one of the most important features of HSPA+ and LTE-A networks; it allows
devices to be served simultaneously by several carriers. We propose two load
balancing schemes, namely Join the Fastest Queue (JFQ) and Volume Balancing
(VB), that allow the traffic of CA and non-CA users to be distributed over the
aggregated carriers. We then evaluate the performance of these schemes by means
of analytical modeling. We show that the proposed schemes achieve quasi-ideal
load balancing. We also investigate the impact of mixing traffic of CA and
non-CA users in the same cell and show that performance is practically
insensitive to the traffic mix.


title: Analytic Evolution of Singular Distribution Amplitudes in QCD

abstract:
  We describe a method of analytic evolution of distribution amplitudes (DA)
that have singularities, such as non-zero values at the end-points of the
support region, jumps at some points inside the support region and cusps. We
illustrate the method by applying it to the evolution of a flat (constant) DA,
antisymmetric flat DA and then use it for evolution of the two-photon
generalized distribution amplitude. Our approach has advantages over the
standard method of expansion in Gegenbauer polynomials, which requires infinite
number of terms in order to accurately reproduce functions in the vicinity of
singular points, and over a straightforward iteration of an initial
distribution with evolution kernel. The latter produces logarithmically
divergent terms at each iteration, while in our method the logarithmic
singularities are summed from the start, which immediately produces a
continuous curve, with only one or two iterations needed afterwards in order to
get rather precise results.


title: Coloured loops in 4D and their effective field representation

abstract:
  Gaining insight about ensembles of magnetic configurations, that could
originate the confining string tension between quarks, constitutes a major
concern in current lattice investigations. This interest also applies to a
different approach, where gauge models with spontaneous symmetry breaking are
constructed to describe the confining string as a smooth vortex solution. In
this article, we initially show how to incorporate non Abelian information into
an ensemble of monopoles in $4D$, characterized by phenomenological parameters.
Next, using some recent techniques developed for polymers, we were able to
relate the coloured ensemble with a non Abelian gauge model. This could offer
an interesting perspective to discuss some of the different approaches to
describe confinement.


title:
Electronic Properties of MoS2/HfO2 Interface: Impact of Interfacial
  Impurities during Atomic Layer Deposition Growth

abstract:
  Using ab-initio calculations within the framework of Density Functional
Theory (DFT), atomic structures and electronic properties of MoS2/HfO2
interface are investigated. The impact of interfacial oxygen concentration on
the MoS2/HfO2 interface electronic structure is examined in order to mimic the
atomic layer deposition growth at ambient conditions. Then, the effect on band
offsets and the thermodynamic stability of those interfaces is investigated and
compared with available relevant experimental data. These results seem to
indicate that, for a well-prepared interface, the electronic device performance
should be better than other interfaces like III-V/high-k due to the absence of
interface defect states. However, any unpassivated defects, if present during
oxide growth, strongly influence the subsequent electronic properties of the
interface.


title:
Reproducing kernels and positivity of vector bundles in infinite
  dimensions

abstract:
  We investigate the interaction between the existence of reproducing kernels
on infinite-dimensional Hermitian vector bundles and the positivity properties
of the corresponding bundles. The positivity refers to the curvature form of
certain covariant derivatives associated to reproducing kernels on the vector
bundles under consideration. The values of the curvature form are Hilbert space
operators, and its positivity is thus understood in the usual sense from
operator theory.


title:
Applying Supervised Learning Algorithms and a New Feature Selection
  Method to Predict Coronary Artery Disease

abstract:
  From a fresh data science perspective, this thesis discusses the prediction
of coronary artery disease based on genetic variations at the DNA base pair
level, called Single-Nucleotide Polymorphisms (SNPs), collected from the
Ontario Heart Genomics Study (OHGS).
  First, the thesis explains two commonly used supervised learning algorithms,
the k-Nearest Neighbour (k-NN) and Random Forest classifiers, and includes a
complete proof that the k-NN classifier is universally consistent in any finite
dimensional normed vector space. Second, the thesis introduces two
dimensionality reduction steps, Random Projections, a known feature extraction
technique based on the Johnson-Lindenstrauss lemma, and a new method termed
Mass Transportation Distance (MTD) Feature Selection for discrete domains.
Then, this thesis compares the performance of Random Projections with the k-NN
classifier against MTD Feature Selection and Random Forest, for predicting
artery disease based on accuracy, the F-Measure, and area under the Receiver
Operating Characteristic (ROC) curve.
  The comparative results demonstrate that MTD Feature Selection with Random
Forest is vastly superior to Random Projections and k-NN. The Random Forest
classifier is able to obtain an accuracy of 0.6660 and an area under the ROC
curve of 0.8562 on the OHGS genetic dataset, when 3335 SNPs are selected by MTD
Feature Selection for classification. This area is considerably better than the
previous high score of 0.608 obtained by Davies et al. in 2010 on the same
dataset.


title: Triangulations of monotone families I: Two-dimensional families

abstract:
  Let $K \subset {\mathbb R}^n$ be a compact definable set in an o-minimal
structure over $\mathbb R$, e.g., a semi-algebraic or a subanalytic set. A
definable family $\{ S_\delta|\> 0< \delta \in {\mathbb R} \}$ of compact
subsets of $K$, is called a monotone family if $S_\delta \subset S_\eta$ for
all sufficiently small $\delta > \eta >0$. The main result of the paper is that
when $\dim K \le 2$ there exists a definable triangulation of $K$ such that for
each (open) simplex $\Lambda$ of the triangulation and each small enough
$\delta>0$, the intersection $S_\delta \cap \Lambda$ is equivalent to one of
the five standard families in the standard simplex (the equivalence relation
and a standard family will be formally defined). The set of standard families
is in a natural bijective correspondence with the set of all five lex-monotone
Boolean functions in two variables. As a consequence, we prove the
two-dimensional case of the topological conjecture in [6] on approximation of
definable sets by compact families. We introduce most technical tools and prove
statements for compact sets $K$ of arbitrary dimensions, with the view towards
extending the main result and proving the topological conjecture in the general
case.


title:
High-accuracy finite-difference schemes for solving elastodynamic
  problems in curvilinear coordinates within multiblock approach

abstract:
  We propose highly accurate finite-difference schemes for simulating wave
propagation problems described by linear second-order hyperbolic equations. The
schemes are based on the summation by parts (SBP) approach modified for
applications with violation of input data smoothness. In particular, we derive
and implement stable schemes for solving elastodynamic anisotropic problems
described by the Navier wave equation in complex geometry. To enhance potential
of the method, we use a general type of coordinate transformation and
multiblock grids. We also show that the conventional spectral element method
(SEM) can be treated as the multiblock finite-difference method whose blocks
are the SEM cells with SBP operators on GLL grid.


title:
Amoebas, Nonnegative Polynomials and Sums of Squares Supported on
  Circuits

abstract:
  We completely characterize sections of the cones of nonnegative polynomials,
convex polynomials and sums of squares with polynomials supported on circuits,
a genuine class of sparse polynomials. In particular, nonnegativity is
characterized by an invariant, which can be immediately derived from the
initial polynomial. Furthermore, nonnegativity of such polynomials $f$
coincides with solidness of the amoeba of $f$, i.e., the Log-absolute-value
image of the algebraic variety $\mathcal{V}(f) \subset (\mathbb{C}^*)^n$ of
$f$.
  These results generalize earlier works both in amoeba theory and real
algebraic geometry by Fidalgo, Kovacec, Reznick, Theobald and de Wolff and
solve an open problem by Reznick. They establish the first direct connection
between amoeba theory and nonnegativity of real polynomials. Additionally,
these statements yield a completely new class of nonnegativity certificates
independent from sums of squares certificates.