title: Charmonium spectral functions from 2+1 flavour lattice QCD

abstract:
  Finite temperature charmonium spectral functions in the pseudoscalar and
vector channels are studied in lattice QCD with 2+1 flavours of dynamical
Wilson quarks, on fine isotropic lattices (with a lattice spacing of 0.057 fm),
with a non-physical pion mass of $m_{\pi} \approx$ 545 MeV. The highest
temperature studied is approximately $1.4 T_c$. Up to this temperature no
significant variation of the spectral function is seen in the pseudoscalar
channel. The vector channel shows some temperature dependence, which seems to
be consistent with a temperature dependent low frequency peak related to heavy
quark transport, plus a temperature independent term at \omega>0. These results
are in accord with previous calculations using the quenched approximation.


title:
Neural Network Aided Glitch-Burst Discrimination and Glitch
  Classification

abstract:
  We investigate the potential of neural-network based classifiers for
discriminating gravitational wave bursts (GWBs) of a given canonical family
(e.g. core-collapse supernova waveforms) from typical transient instrumental
artifacts (glitches), in the data of a single detector. The further
classification of glitches into typical sets is explored.In order to provide a
proof of concept,we use the core-collapse supernova waveform catalog produced
by H. Dimmelmeier and co-Workers, and the data base of glitches observed in
laser interferometer gravitational wave observatory (LIGO) data maintained by
P. Saulson and co-Workers to construct datasets of (windowed) transient
waveforms (glitches and bursts) in additive (Gaussian and compound-Gaussian)
noise with different signal-tonoise ratios (SNR). Principal component analysis
(PCA) is next implemented for reducing data dimensionality, yielding results
consistent with, and extending those in the literature. Then, a multilayer
perceptron is trained by a backpropagation algorithm (MLP-BP) on a data subset,
and used to classify the transients as glitch or burst. A Self-Organizing Map
(SOM) architecture is finally used to classify the glitches. The glitch/burst
discrimination and glitch classification abilities are gauged in terms of the
related truth tables. Preliminary results suggest that the approach is
effective and robust throughout the SNR range of practical interest.
Perspective applications pertain both to distributed (network, multisensor)
detection of GWBs, where someintelligenceat the single node level can be
introduced, and instrument diagnostics/optimization, where spurious transients
can be identified, classified and hopefully traced back to their entry points


title: Effects of concavity on the motion of a body immersed in a Vlasov gas

abstract:
  We consider a body immersed in a perfect gas, moving under the action of a
constant force $E$ along the $ x $ axis . We assume the gas to be described by
the mean-field approximation and interacting elastically with the body. Such a
dynamic was studied in previous papers In these studies the asymptotic trend
showed no sensitivity whatsoever to the shape of the object moving through the
gas. In this work we investigate how a simple concavity in the shape of the
body can affect its asymptotic behavior; we thus consider the case of hollow
cylinder in three dimensions or a box-like body in two dimensions. We study the
approach of the body velocity $V (t) $ to the limiting velocity $V_{\infty} $
and prove that, under suitable smallness assumptions, the approach to
equilibrium is $| V_{\infty}-V(t)| \approx C t^{-3} $ both in two or three
dimensions, being $C$ a positive constant. This approach is not exponential, as
typical in friction problems, and even slower than for the simple disk and the
convex body in $ \mathbb{R}^2 $ or $ \mathbb{R}^3 $.


title: On a Cahn-Hilliard type phase field system related to tumor growth

abstract:
  The paper deals with a phase field system of Cahn-Hilliard type. For positive
viscosity coefficients, the authors prove an existence and uniqueness result
and study the long time behavior of the solution by assuming the nonlinearities
to be rather general. In a more restricted setting, the limit as the viscosity
coefficients tend to zero is investigated as well.


title: Radiative Symmetry Breaking from Flat Potential in various U(1)' models

abstract:
  We investigate a radiative electroweak gauge symmetry breaking scenario via
the Coleman-Weinberg mechanism starting from a completely flat Higgs potential
at the Planck scale ("flatland scenario"). In our previous paper, we showed
that the flatland scenario is possible only when an inequality K<1 among the
coefficients of the beta functions is satisfied. In this paper, we calculate
the number K in various models with an extra U(1) gauge sector in addition to
the SM particles. We also show the renormalization group (RG) behaviors of a
couple of the models as examples.


title: A comet could not produce the carbon-14 spike in the 8th century

abstract:
  A mysterious increase of radiocarbon 14C ca. 775 AD in the Earth's atmosphere
has been recently found by Miyake et al. (Nature, 486, 240, 2012). A possible
source of this event has been discussed widely, the most likely being an
extreme solar energetic particle event. A new exotic hypothesis has been
presented recently by Liu et al. (Nature Sci. Rep., 4, 3728, 2014) who proposed
that the event was caused by a comet bringing additional 14C to Earth. Here we
calculated a realistic mass and size of such a comet to show that it would have
been huge (~100 km across and 10^{14}-10^{15} ton of mass) and would have
produced a disastrous impact on Earth. Such an impact could not remain
unnoticed in the geological records and chronicles. The absence of an evidence
for such a dramatic event makes this hypothesis invalid.


title: On graph-like continua of finite length

abstract:
  We extend the notion of effective resistance to metric spaces that are
similar to graphs but can also be similar to fractals. Combined with other
basic facts proved in the paper, this lays the ground for a construction of
Brownian Motion on such spaces completed in [10].


title: AR-components for generalized Beilinson algebras

abstract:
  We show that the generalized W-modules defined in a foregoing paper determine
ZA_\infty- components in the Auslander-Reiten quiver \Gamma(n,r) of the
generalized Beilinson algebra B(n,r), n \geq 3. These components entirely
consist of modules with the constant Jordan type property. We arrive at this
result by interpreting B(n,r) as an iterated one-point extension of the
r-Kronecker algebra K_r which enables us to generalize findings concerning the
Auslander-Reiten quiver \Gamma(K_r) presented in earlier work to B(n,r).


title:
Branching Fractions and Direct CP Asymmetries of $\bar B_s ^0 \to K^0
  h^+h^{\prime -}(h^{(\prime)}=K,\pi)$ Decays

abstract:
  Motivated by the recent LHCb collaboration measurements of charmless
three-body decays of $\bar B_s^0$ meson, we calculate the branching fractions
of $\bar B_s ^0 \to K^0 \pi^+\pi^-$, $\bar B_s ^0 \to K^0 K^+K^-$, $\bar B_s ^0
\to K^0 \pi^+K^-$ and $\bar B_s ^0 \to \bar K^0 K^+\pi^-$ decay modes using the
factorization approach. Both the resonant and nonresonant contributions are
studied in detail. For the decays $\bar B_s ^0 \to K^0 \pi^+\pi^-$ and $\bar
B_s ^0 \to K^0 K^+K^-$, our results agree well with experimental data, and the
former is dominated by the $K^*$, while the latter one is dominated by the
nonresonant contribution. Considering the flavor SU(3) symmetry violation, the
sum of branching fractions of $\bar B_s ^0 \to K^0 \pi^+K^-$ and $\bar B_s ^0
\to \bar K^0 K^+\pi^-$ could accommodate the data well too. It should be noted
that both branching fractions are sensitive to the scalar density $< K\pi| \bar
s q|0>$. Furthermore, the resonant contributions are dominated by the scalar
$K_0^*(1430)$. We hope that these branching fractions could be measured
individually in the experiments so as to test the factorization approach and
the flavor SU(3) asymmetry. Moreover, the direct CP asymmetries of these decays
are also investigated, which could be measured in the running LHCb experiment
and Super-b factory in the future.


title:
The Sylvester equation and integrable equations: I. The Korteweg-de
  Vries system and sine-Gordon equation

abstract:
  The paper is to reveal the direct links between the well known Sylvester
equation in matrix theory and some integrable systems. Using the Sylvester
equation $\boldsymbol{K} \boldsymbol{M}+\boldsymbol{M}
\boldsymbol{K}=\boldsymbol{r}\, \boldsymbol{s}^{T}$ we introduce a scalar
function $S^{(i,j)}=\boldsymbol{s}^{T}\,
\boldsymbol{K}^j(\boldsymbol{I}+\boldsymbol{M})^{-1}\boldsymbol{K}^i\boldsymbol{r}$
which is defined as same as in discrete case. $S^{(i,j)}$ satisfy some
recurrence relations which can be viewed as discrete equations and play
indispensable roles in deriving continuous integrable equations. By imposing
dispersion relations on $\boldsymbol{r}$ and $\boldsymbol{s}$, we find the
Korteweg-de Vries equation, modified Korteweg-de Vries equation, Schwarzian
Korteweg-de Vries equation and sine-Gordon equation can be expressed by some
discrete equations of $S^{(i,j)}$ defined on certain points. Some special
matrices are used to solve the Sylvester equation and prove symmetry property
$S^{(i,j)}=S^{(i,j)}$. The solution $\boldsymbol{M}$ provides $\tau$ function
by $\tau=|\boldsymbol{I}+\boldsymbol{M}|$. We hope our results can not only
unify the Cauchy matrix approach in both continuous and discrete cases, but
also bring more links for integrable systems and variety of areas where the
Sylvester equation appears frequently.


title: Time-dependent Transport in arbitrary extended driven tunnel junctions

abstract:
  We develop a very general perturbative theory of time-dependent transport in
a weak tunneling junction which is independent of experimental details and on
many-body correlated states in the coupled conductors. These can be similar or
different, with arbitrary internal or mutual interactions, superconducting
correlations, disorder, and coupled to an electromagnetic environment or other
quantum systems. The junction can be spatially extended, and is subject,
simultaneously, to time-dependent voltage, local magnetic field and modulation
of the tunneling amplitudes. All observables at arbitrary frequencies: average
current, non-equilibrium admittance and current correlations can be expressed
in a universal way through the out-of-equilibrium DC current only, yielding
perturbative time-dependent non-equilibrium fluctuation relations. In
particular, charge fluctuations are shown to be universally super-poissonian,
and to become poissonian if the junction is driven by a series of Lorentzian
pulses. We also generalize, for constant voltage and tunneling, the poissonian
shot noise and the fluctuation relation between the derivatives of the noise
and the conductance. Thus we provide a compact, general and transparent
unifying theory at arbitrary dimension, in contrast with involved derivations
based explicitly on particular models and profiles of a single time-varying
field.


title:
An Efficient Algorithm for the Equation Tree Automaton via the
  $k$-C-Continuations

abstract:
  Champarnaud and Ziadi, and Khorsi et al. show how to compute the equation
automaton of word regular expression $E$ via the $k$-C-Continuations.
  Kuske and Meinecke extend the computation of the equation automaton to a
regular tree expression $E$ over a ranked alphabet $\Sigma$ and produce a
$O(R\cdot|E|^2)$ time and space complexity algorithm, where $R$ is the maximal
rank of a symbol occurring in $\Sigma$ and $|E|$ is the size of $E$. In this
paper, we give a full description of the algorithm based on the acyclic
minimization of Revuz. Our algorithm, which is performed in an $O(|Q|\cdot|E|)$
time and space complexity, where $|Q|$ is the number of states of the produced
automaton, is more efficient than the one obtained by Kuske and Meinecke.


title:
Compression of Ultrashort Laser Pulses via Gated Multiphoton Intrapulse
  Interference Phase Scans

abstract:
  Delivering femtosecond laser light in the focal plane of a high numerical
aperture microscope objective is still a challenge, despite significant
developments in the generation of ultrashort pulses. One of the most popular
techniques, used to correct phase distortions resulting from propagation
through transparent media, is the multiphoton intrapulse interference phase
scan (MIIPS). The accuracy of MIIPS however is limited when higher order phase
distortions are present. Here we introduce an improvement, called Gated-MIIPS,
which avoids shortcomings of MIIPS, reduces the influence of higher order phase
terms, and can be used to more efficiently compress broad band laser pulses
even with a simple 4f pulse shaper setup. In this work we present analytical
formulas for MIIPS and Gated-MIIPS valid for chirped Gaussian pulses; we show
an approximated analytic expression for Gated-MIIPS valid for arbitrary pulse
shapes; finally we demonstrate the increased accuracy of Gated-MIIPS via
experiment and numerical simulation.


title:
A Generalization of the {\L}o\'s-Tarski Preservation Theorem over
  Classes of Finite Structures

abstract:
  We investigate a generalization of the {\L}o\'s-Tarski preservation theorem
via the semantic notion of \emph{preservation under substructures modulo
$k$-sized cores}. It was shown earlier that over arbitrary structures, this
semantic notion for first-order logic corresponds to definability by
$\exists^k\forall^*$ sentences. In this paper, we identify two properties of
classes of finite structures that ensure the above correspondence. The first is
based on well-quasi-ordering under the embedding relation. The second is a
logic-based combinatorial property that strictly generalizes the first. We show
that starting with classes satisfying any of these properties, the classes
obtained by applying operations like disjoint union, cartesian and tensor
products, or by forming words and trees over the classes, inherit the same
property. As a fallout, we obtain interesting classes of structures over which
an effective version of the {\L}o\'s-Tarski theorem holds.


title:
Characterization of the low temperature properties of a simplified
  protein model

abstract:
  Prompted by results that showed that a simple protein model, the frustrated
G\=o model, appears to exhibit a transition reminiscent of the protein
dynamical transition, we examine the validity of this model to describe the
low-temperature properties of proteins. First, we examine equilibrium
fluctuations. We calculate its incoherent neutron-scattering structure factor
and show that it can be well described by a theory using the one-phonon
approximation. By performing an inherent structure analysis, we assess the
transitions among energy states at low temperatures. Then, we examine
non-equilibrium fluctuations after a sudden cooling of the protein. We
investigate the violation of the fluctuation--dissipation theorem in order to
analyze the protein glass transition. We find that the effective temperature of
the quenched protein deviates from the temperature of the thermostat, however
it relaxes towards the actual temperature with an Arrhenius behavior as the
waiting time increases. These results of the equilibrium and non-equilibrium
studies converge to the conclusion that the apparent dynamical transition of
this coarse-grained model cannot be attributed to a glassy behavior.


title: Energetics of single active diffusion trajectories

abstract:
  The fundamental insight into Brownian motion by Einstein is that all
substances exhibit continual fluctuations due to thermal agitation balancing
with the frictional resistance. However, even at thermal equilibrium,
biological activity can give rise to non-equilibrium fluctuations that cause
``active diffusion" in living cells. Because of the non-stationary and
non-equilibrium nature of such fluctuations, mean square displacement analysis,
relevant only to a steady state ensemble, may not be the most suitable choice
as it depends on the choice of the ensemble; hence, a new analytical method for
describing active diffusion is desired. Here we discuss the stochastic
energetics of a thermally fluctuating single active diffusion trajectory driven
by non-thermal random forces. Heat dissipation, usually difficult to measure,
can be estimated from the active diffusion trajectory; guidelines on the
analysis such as criteria for the time resolution and driving force intensity
are shown by a statistical test. This leads to the concept of an
``instantaneous diffusion coefficient" connected to heat dissipation that may
be used to analyse the activity and molecular transport mechanisms of living
systems.


title:
Efficient Decentralized Economic Dispatch for Microgrids with Wind Power
  Integration

abstract:
  Decentralized energy management is of paramount importance in smart
microgrids with renewables for various reasons including environmental
friendliness, reduced communication overhead, and resilience to failures. In
this context, the present work deals with distributed economic dispatch and
demand response initiatives for grid-connected microgrids with high-penetration
of wind power. To cope with the challenge of the wind's intrinsically
stochastic availability, a novel energy planning approach involving the actual
wind energy as well as the energy traded with the main grid, is introduced. A
stochastic optimization problem is formulated to minimize the microgrid net
cost, which includes conventional generation cost as well as the expected
transaction cost incurred by wind uncertainty. To bypass the prohibitively
high-dimensional integration involved, an efficient sample average
approximation method is utilized to obtain a solver with guaranteed
convergence. Leveraging the special infrastructure of the microgrid, a
decentralized algorithm is further developed via the alternating direction
method of multipliers. Case studies are tested to corroborate the merits of the
novel approaches.


title: A stochastic evolutionary model for survival dynamics

abstract:
  The recent interest in human dynamics has led researchers to investigate the
stochastic processes that explain human behaviour in different contexts. Here
we propose a generative model to capture the essential dynamics of survival
analysis, traditionally employed in clinical trials and reliability analysis in
engineering. In our model, the only implicit assumption made is that the longer
an actor has been in the system, the more likely it is to have failed. We
derive a power-law distribution for the process and provide preliminary
empirical evidence for the validity of the model from two well-known survival
analysis data sets.


title:
The values of the high order Bernoulli polynomials at integers and the
  r-Stirling numbers

abstract:
  In this paper, we exploit the r-Stirling numbers of both kinds in order to
give explicit formulae for the values of the high order Bernoulli numbers and
polynomials of both kinds at integers. We give also some identities linked the
r-Stirling numbers and binomial coefficients.


title:
The Differential Dimension Polynomial for Characterizable Differential
  Ideals

abstract:
  We generalize the differential dimension polynomial from prime differential
ideals to characterizable differential ideals. Its computation is algorithmic,
its degree and leading coefficient remain differential birational invariants,
and it decides equality of characterizable differential ideals contained in
each other.


title: The Ground State Energy of a Dilute Bose Gas in Dimension n >3

abstract:
  We consider a Bose gas in spatial dimension $n>3$ with a repulsive, radially
symmetric two-body potential $V$. In the limit of low density $\rho$, the
ground state energy per particle in the thermodynamic limit is shown to be
$(n-2)|\mathbb S^{n-1}|a^{n-2}\rho$, where $|\mathbb S^{n-1}|$ denotes the
surface measure of the unit sphere in $\mathbb{R}^n$ and $a$ is the scattering
length of $V$. Furthermore, for smooth and compactly supported two-body
potentials, we derive upper bounds to the ground state energy with a correction
term $(1+C\gamma)8\pi^4a^6\rho^2|\ln(a^4\rho)|$ in dimension $n=4$, where
$\gamma:=\int V(x)|x|^{-2}\, dx$, and a correction term which is
$\mathcal{O}(\rho^2)$ in higher dimensions.


title: Quantum phases in tunable state-dependent hexagonal optical lattices

abstract:
  We study the ground-state properties of ultracold bosonic atoms in a
state-dependent graphene-like honeycomb optical lattice, where the degeneracy
between the two triangular sublattices A and B can be lifted. We discuss the
various geometries accessible with this lattice setup and present a novel
scheme to control the energy offset with external magnetic fields. The
competition of the on-site interaction with the offset energy leads to Mott
phases characterized by population imbalances between the sublattices. For the
definition of an optimal Hubbard model, we demonstrate a scheme that allows for
the efficient computation of Wannier functions. Using a cluster mean-field
method, we compute the phase diagrams and provide a universal representation
for arbitrary energy offsets. We find good agreement with the experimental data
for the superfluid to Mott insulator transition.


title:
Rotationally resolved spectroscopy of (20000) Varuna in the
  near-infrared

abstract:
  Models of the escape and retention of volatiles by minor icy objects exclude
any presence of volatile ices on the surface of TNOs smaller than ~1000km in
diameter at the typical temperature in this region of the solar system, whereas
the same models show that water ice is stable on the surface of objects over a
wide range of diameters. Collisions and cometary activity have been used to
explain the process of surface refreshing of TNOs and Centaurs. These processes
can produce surface heterogeneity that can be studied by collecting information
at different rotational phases. The aims of this work are to study the surface
composition of (20000)Varuna, a TNO with a diameter ~650km and to search for
indications of rotational variability. We observed Varuna during two
consecutive nights in January 2011 with NICS@TNG obtaining a set of spectra
covering the whole rotation period of Varuna. After studying the spectra
corresponding to different rotational phases, we did not find any indication of
surface variability. In all the spectra, we detect an absorption at 2{\mu}m,
suggesting the presence of water ice on the surface. We do not detect any other
volatiles on the surface, although the S/N is not high enough to discard their
presence. Based on scattering models, we present two possible compositions
compatible with our set of data and discuss their implications in the frame of
the collisional history of the Kuiper Belt. We find that the most probable
composition for the surface of Varuna is a mixture of amorphous silicates,
complex organics, and water ice. This composition is compatible with all the
materials being primordial. However, our data can also be fitted by models
containing up to a 10% of methane ice. For an object with the characteristics
of Varuna, this volatile could not be primordial, so an event, such as an
energetic impact, would be needed to explain its presence on the surface.


title: Spectral Similarity of Unbound Asteroid Pairs

abstract:
  Infrared spectroscopy between 0.8 and 2.5 microns has been obtained for both
components of three unbound asteroid pairs, using the NASA-IRTF with the SpeX
instrument. Pair primary (2110) Moore-Sitterly is classified as an S-type
following the Bus-DeMeo taxonomy; the classification for secondary (44612) 1999
RP27 is ambiguous: S/Sq/Q/K/L-type. Primary (10484) Hecht and secondary (44645)
1999 RC118 are classified as V-types. IR spectra for Moore-Sitterly and Hecht
are each linked with available visual photometry. The classifications for
primary (88604) 2001 QH293 and (60546) 2000 EE85 are ambiguous:
S/Sq/Q/K/L-type. Subtle spectral differences between them suggest the primary
may have more weathered material on its surface. Dynamical integrations have
constrained the ages of formation: 2110-44612 > 782 kyr; 10484-44645 = 348
(+823,-225) kyr; 88604-60546 = 925 (+842,-754) kyr. The spectral similarity of
seven complete pairs is ranked in comparison with nearby background asteroids.
Two pairs, 17198-229056 and 19289-278067, have significantly different spectra
between the components, compared to the similarity of spectra in the background
population. The other pairs are closer than typical, supporting an
interpretation of each pair's formation from a common parent body.


title:
Bounds on quantum process fidelity from minimum required number of
  quantum state fidelity measurements

abstract:
  To certify that an experimentally implemented quantum transformation is a
certain unitary operation U on a d-dimensional Hilbert space, it suffices to
determine fidelities of output states for d+1 suitably chosen pure input states
[Reich et al., Phys. Rev. A 88, 042309 (2013)]. The set of these d+1 probe
states can consist of d orthogonal states that form a basis and one additional
state which is a balanced superposition of all d basis states. Here we provide
an analytical lower bound on quantum process fidelity for two-qubit quantum
gates which results from the knowledge of average state fidelity for the basis
states and the fidelity of the superposition state. We compare this bound with
the Hofmann bound that is based on knowledge of average state fidelities for
two mutually unbiased bases. We also discuss possible extension of our findings
to N-qubit operations.


title: Pairwise hydrodynamic interactions and diffusion in a vesicle suspension

abstract:
  The hydrodynamic interaction of two deformable vesicles in shear flow induces
a net displacement, in most cases an increase of their distance in the
transverse direction. The statistical average of these interactions leads to
shear-induced diffusion in the suspension, both at the level of individual
particles which experience a random walk made of successive interactions, and
at the level of suspension where a non-linear down-gradient diffusion takes
place, an important ingredient in the structuring of suspension flows. We make
an experimental and computational study of the interaction of a pair of lipid
vesicles in shear flow by varying physical parameters, and investigate the
decay of the net lateral displacement with the distance between the streamlines
on which the vesicles are initially located. This decay and its dependency upon
vesicle properties can be accounted for by a simple model based on the well
established law for the lateral drift of a vesicle in the vicinity of a wall.
In the semi-dilute regime, a determination of self-diffusion coefficients is
presented.


title: Image Block Loss Restoration Using Sparsity Pattern as Side Information

abstract:
  In this paper, we propose a method for image block loss restoration based on
the notion of sparse representation. We use the sparsity pattern as side
information to efficiently restore block losses by iteratively imposing the
constraints of spatial and transform domains on the corrupted image. Two novel
features, including a pre-interpolation and a criterion for stopping the
iterations, are proposed to improve the performance. Also, to deal with
practical applications, we develop a technique to transmit the side information
along with the image. In this technique, we first compress the side information
and then embed its LDPC coded version in the least significant bits of the
image pixels. This technique ensures the error-free transmission of the side
information, while causing only a small perturbation on the transmitted image.
Mathematical analysis and extensive simulations are performed to validate the
method and investigate the efficiency of the proposed techniques. The results
verify that the proposed method outperforms its counterparts for image block
loss restoration.


title: Coron problem for fractional equations

abstract:
  We prove that the critical problem for the fractional Laplacian in an annular
type domain admits a nontrivial solution provided that the inner hole is
sufficiently small.


title: Simulation study of the plasma brake effect

abstract:
  The plasma brake is a thin negatively biased tether which has been proposed
as an efficient concept for deorbiting satellites and debris objects from low
Earth orbit. We simulate the interaction with the ionospheric plasma ram flow
with the plasma brake tether by a high performance electrostatic particle in
cell code to evaluate the thrust. The tether is assumed to be perpendicular to
the flow. We perform runs for different tether voltage, magnetic field
orientation and plasma ion mass. We show that a simple analytical thrust
formula reproduces most of the simulation results well. The interaction with
the tether and the plasma flow is laminar (i.e., smooth and not turbulent) when
the magnetic field is perpendicular to the tether and the flow. If the magnetic
field is parallel to the tether, the behaviour is unstable and thrust is
reduced by a modest factor. The case when the magnetic field is aligned with
the flow can also be unstable, but does not result in notable thrust reduction.
We also fix an error in an earlier reference. According to the simulations, the
predicted thrust of the plasma brake is large enough to make the method
promising for low Earth orbit (LEO) satellite deorbiting. As a numerical
example we estimate that a 5 km long plasma brake tether weighing 0.055 kg
could produce 0.43 mN breaking force which is enough to reduce the orbital
altitude of a 260 kg object mass by 100 km during one year.


title: Entropy of subordinate shift spaces

abstract:
  We introduce a new family of shift spaces --- the subordinate shifts. Using
subordinate shifts we prove in an elementary way that for every nonnegative
real number $t$ there is a shift space with entropy $t$.


title: The Spinless Relativistic Woods-Saxon Problem

abstract:
  Motivated by the observation of a recent renewal of rather strong interest in
the description of bound states by (semi-) relativistic equations of motion, we
revisit, for the example of the Woods-Saxon interactions, the eigenvalue
problem posed by the spinless Salpeter equation and recall various elementary
knowledge, considerations, and techniques that practitioners seeking solutions
to this specific reduction of the Bethe-Salpeter equation may find helpful.


title: Magnetic AC control of the spin textures in a helical Luttinger liquid

abstract:
  We demonstrate the possibility to induce and control peculiar spin textures
in a helical Luttinger liquid, by means of a time-dependent magnetic scatterer.
The presence of a perturbation that breaks the time-reversal symmetry opens a
gap in the spectrum, inducing single-particle backscattering and a peculiar
spin response. We show that in the weak backscattering regime asymmetric spin
textures emerge at the left and right side of the scatterer, whose spatial
oscillations are controlled by the ratio between the magnetization frequency
and the Fermi energy and by the electron interaction. This peculiar spin
response marks a strong difference between helical and non-helical liquids,
which are expected to produce symmetric spin textures even in the AC regime.


title: Optical properties of irradiated epitaxial GaN films

abstract:
  The influence of a microwave treatment (MWT) on the optical properties of
hexagonal GaN films has been studied. To estimate the internal mechanical
strains and the degree of structural perfection in a thin near-surface layer of
the film, the electroreflectance (ER) method is used. The ER spectra are
measured in the interval of the first direct interband transitions. It has been
shown that the MWT results in the relaxation of internal mechanical strains in
the irradiated films. In addition, the structural perfection in the thin
near-surface layer of the irradiated film became higher. A mechanism that
includes resonance effects and the local heating of the film defect regions is
proposed to explain the effects observed.


title: Isentropic perturbations of a chaotic domain

abstract:
  Three major properties of the chaotic dynamics of the standard map, namely,
the measure \mu of the main connected chaotic domain, the maximum Lyapunov
exponent L of the motion in this domain, and the dynamical entropy h = \mu L
are studied as functions of the stochasticity parameter K. The perturbations of
the domain due to emergence and disintegration of islands of stability, upon
small variations of K, are considered in particular. By means of extensive
numerical experiments, it is shown that these perturbations are isentropic (at
least approximately). In other words, the dynamical entropy does not fluctuate,
while local jumps in \mu and L are significant.


title: Fermion zero modes in a chromomagnetic vortex lattice

abstract:
  We prove the existence of zero modes of massless quarks in a background of
spaghetti vacuum of chromomagnetic vortices in QCD. We find a general solution
for the zero modes and show that the modes can be localized at pairs of
vortices.


title: Towards a general fluid/gravity correspondence

abstract:
  We set up the construction of generic (d+2)-dimensional metrics corresponding
to (d+1)-dimensional fluids, representing holographically the hydrodynamic
regimes of the putative dual theories. We give general seed equilibrium metrics
appropriate to generic bulk stress energy tensors and discuss the implications
of conformal rescalings of the hypersurface on which the fluid is defined. We
then show how to obtain the corresponding hydrodynamic metrics using a
relativistic gradient expansion and discuss the integrability conditions of the
resulting equations. The stress energy tensors of the resulting fluids, both at
and away from equilibrium, satisfy a quadratic constraint. We interpret this
constraint in terms of two possible equations of state for the fluid and show
that only one of the two equations is physical. We illustrate our discussions
with the example of the cutoff AdS fluid, for which we find the precise
interpretation in terms of deformations of the UV conformal field theory.
Finally we discuss the relation between the modern fluid/gravity approach taken
in this paper and the earlier membrane paradigm.


title: Electron-spin dynamics induced by photon spins

abstract:
  Strong rotating magnetic fields may cause a precession of the electron's spin
around the rotation axis of the magnetic field. The superposition of two
counterpropagating laser beams with circular polarization and opposite helicity
features such a rotating magnetic field component but also carries spin. The
laser's spin density, that can be expressed in terms of the lase's
electromagnetic fields and potentials, couples to the electron's spin via a
relativistic correction to the Pauli equation. We show that the quantum
mechanical interaction of the electron's spin with the laser's rotating
magnetic field and with the laser's spin density counteract each other in such
a way that a net spin rotation remains with a precession frequency that is much
smaller than the frequency one would expect from the rotating magnetic field
alone. In particular, the frequency scales differently with the laser's
electric field strength depending on if relativistic corrections are taken into
account or not. Thus, the relativistic coupling of the electron's spin to the
laser's spin density changes the dynamics not only quantitatively but also
qualitatively as compared to the nonrelativistic theory. The electron's spin
dynamics is a genuine quantum mechanical relativistic effect.


title: SuSy: The Early Years (1966-1976)

abstract: We describe the early evolution of theories with fermion-boson symmetry


title: Some q-analogues of supercongruences of Rodriguez-Villegas

abstract:
  We study different q-analogues and generalizations of the ex-conjectures of
Rodriguez-Villegas. For example, for any odd prime p, we show that the known
congruence \sum_{k=0}^{p-1}\frac{{2k\choose k}^2}{16^k} \equiv
(-1)^{\frac{p-1}{2}}\pmod{p^2} has the following two nice q-analogues with
[p]=1+q+...+q^{p-1}:
\sum_{k=0}^{p-1}\frac{(q;q^2)_k^2}{(q^2;q^2)_k^2}q^{(1+\varepsilon)k} &\equiv
(-1)^{\frac{p-1}{2}}q^{\frac{(p^2-1)\varepsilon}{4}}\pmod{[p]^2}, where
(a;q)_0=1, (a;q)_n=(1-a)(1-aq)...(1-aq^{n-1}) for n=1,2,..., and
\varepsilon=\pm1. Several related conjectures are also proposed.


title:
Fully hadronic decays of a singly produced vector-like top partner at
  the LHC

abstract:
  Single production of vector-like top partners is becoming a major focus of
new searches, as the increasing mass limits on vector-like quarks obtained by
the ATLAS and CMS collaborations are such that single production is becoming
competitive with respect to pair production. Typically searches focus on decays
containing leptons in the final state in order to have less background from the
Standard Model processes. However the current centre of mass energies available
in the latest LHC runs limit the searches to low masses. Fully hadronic final
states may be an alternative option for discovery, as they allow a larger
number of signal events if backgrounds can be kept under control. We study the
fully hadronic decay of a singly produced vector-like top partner and we show a
strategy to extract the signal over the background, considering as a benchmark
the 20 fb^-1 of data collected at 8 TeV with the latest run of the LHC.


title:
Reasoning about Meaning in Natural Language with Compact Closed
  Categories and Frobenius Algebras

abstract:
  Compact closed categories have found applications in modeling quantum
information protocols by Abramsky-Coecke. They also provide semantics for
Lambek's pregroup algebras, applied to formalizing the grammatical structure of
natural language, and are implicit in a distributional model of word meaning
based on vector spaces. Specifically, in previous work Coecke-Clark-Sadrzadeh
used the product category of pregroups with vector spaces and provided a
distributional model of meaning for sentences. We recast this theory in terms
of strongly monoidal functors and advance it via Frobenius algebras over vector
spaces. The former are used to formalize topological quantum field theories by
Atiyah and Baez-Dolan, and the latter are used to model classical data in
quantum protocols by Coecke-Pavlovic-Vicary. The Frobenius algebras enable us
to work in a single space in which meanings of words, phrases, and sentences of
any structure live. Hence we can compare meanings of different language
constructs and enhance the applicability of the theory. We report on
experimental results on a number of language tasks and verify the theoretical
predictions.


title: Background-independent measurement of $\theta_{13}$ in Double Chooz

abstract:
  The oscillation results published by the Double Chooz collaboration in 2011
and 2012 rely on background models substantiated by reactor-on data. In this
analysis, we present a background-model-independent measurement of the mixing
angle $\theta_{13}$ by including 7.53 days of reactor-off data. A global fit of
the observed neutrino rates for different reactor power conditions is
performed, yielding a measurement of both $\theta_{13}$ and the total
background rate. The results on the mixing angle are improved significantly by
including the reactor-off data in the fit, as it provides a direct measurement
of the total background rate. This reactor rate modulation analysis considers
antineutrino candidates with neutron captures on both Gd and H, whose
combination yields $\sin^2(2\theta_{13})=$ 0.102 $\pm$ 0.028(stat.) $\pm$
0.033(syst.). The results presented in this study are fully consistent with the
ones already published by Double Chooz, achieving a competitive precision. They
provide, for the first time, a determination of $\theta_{13}$ that does not
depend on a background model.


title: The discovery of a T6.5 subdwarf

abstract:
  We report the discovery of ULAS J131610.28+075553.0, a sdT6.5 dwarf in the
UKIDSS Large Area Survey 2 epoch proper motion catalogue. This object displays
significant spectral peculiarity, with the largest yet seen deviations from T6
and T7 templates in the Y and K bands for this subtype. Its large, ~1
arcsec/yr, proper motion suggests a large tangential velocity of Vtan = 240 -
340km/s, if we assume its MJ lies within the typical range for T6.5 dwarfs.
This makes it a candidate for membership of the Galactic halo population.
However, other metal poor T dwarfs exhibit significant under luminosity both in
specific bands and bolometrically. As a result, it is likely that its velocity
is somewhat smaller, and we conclude it is a likely thick disc or halo member.
This object represents the only T dwarf earlier than T8 to be classified as a
subdwarf, and is a significant addition to the currently small number of known
unambiguously substellar subdwarfs.


title: The local Callan-Symanzik equation: structure and applications

abstract:
  The local Callan-Symanzik equation describes the response of a quantum field
theory to local scale transformations in the presence of background sources.
The consistency conditions associated with this anomalous equation imply
non-trivial relations among the $\beta$-function, the anomalous dimensions of
composite operators and the short distance singularities of correlators. In
this paper we discuss various aspects of the local Callan-Symanzik equation and
present new results regarding the structure of its anomaly. We then use the
equation to systematically write the n-point correlators involving the trace of
the energy-momentum tensor. We use the latter result to give a fully detailed
proof that the UV and IR asymptotics in a neighbourhood of a 4D CFT must also
correspond to CFTs. We also clarify the relation between the matrix entering
the gradient flow formula for the $\beta$-function and a manifestly positive
metric in coupling space associated with matrix elements of the trace of the
energy momentum tensor.


title: Einstein-Cartan Calculus for Exceptional Geometry

abstract:
  In this paper we establish and clarify the link between the recently found E7
generalised geometric structures, which are based on the SU(8) invariant
reformulation of D=11 supergravity proposed long ago, and newer results
obtained in the framework of recent approaches to generalised geometry, where
E7 duality is built in and manifest from the outset. In making this connection,
the so-called generalised vielbein postulate plays a key role. We explicitly
show how this postulate can be used to define an E7 valued affine connection
and an associated covariant derivative, which yields a generalised curvature
tensor for the E7 based exceptional geometry. The analysis of the generalised
vielbein postulate also provides a natural explanation for the emergence of the
embedding tensor from higher dimensions.


title:
Analytical solutions for cosmological perturbations in a one-component
  universe with shear stress

abstract:
  We construct explicit solutions for scalar, vector and tensor perturbations
in a less known setting, a flat universe filled by an isotropic elastic solid
with pressure and shear modulus proportional to energy density. The solutions
generalize the well known formulas for cosmological perturbations in a universe
filled by ideal fluid.


title:
How are excellent (highly cited) papers defined in bibliometrics? A
  quantitative analysis of the literature

abstract:
  As the subject of research excellence has received increasing attention (in
science policy) over the last few decades, increasing numbers of bibliometric
studies have been published dealing with excellent papers. However, many
different methods have been used in these studies to identify excellent papers.
The present quantitative analysis of the literature has been carried out in
order to acquire an overview of these methods and an indication of an "average"
or "most frequent" bibliometric practice. The search in the Web of Science
yielded 321 papers dealing with "highly cited", "most cited", "top cited" and
"most frequently cited". Of the 321 papers, 16 could not be used in this study.
In around 80% of the papers analyzed in this study, a quantitative definition
has been provided with which to identify excellent papers. With definitions
which relate to an absolute number, either a certain number of top cited papers
(58%) or papers with a minimum number of citations are selected (17%). Around
23% worked with percentile rank classes. Over these papers, there is an
arithmetic average of the top 7.6% (arithmetic average) or of the top 3%
(median). The top 1% is used most frequently in the papers, followed by the top
10%. With the thresholds presented in this study, in future, it will be
possible to identify excellent papers based on an "average" or "most frequent"
practice among bibliometricians.


title: 3C 273 - half a century later

abstract:
  We have presented an optical monitoring of 3C 273, the first quasar
discovered fifty years ago. It does not show variability both on intra-night
and long-term time scales. To facilitate the further monitoring of 3C 273, we
compiled the available calibrations of the comparison stars in its field into a
mean sequence.


title: Quelling the concerns of EPR and Bell

abstract:
  We begin with a review of the famous thought experiment that was proposed by
Einstein, Podolsky and Rosen (EPR) and mathematically formulated by Bell; the
outcomes of which challenge the completeness of quantum mechanics and the
locality of Nature. We then suggest a reinterpretation of the EPR experiment
that utilizes observer complementarity; a concept from quantum gravity which
allows spatially separated observers to have their own, independent reference
frames. The resulting picture provides a self-consistent resolution of the
situation that does not jeopardize causality nor unitarity, nor does it resort
to ''spooky'' (non-local) interactions. Our conclusion is that EPR and Bell
rely on an overly strong definition of locality that is in conflict with
fundamental physics.


title:
Problem of oscillations presence at $CP$ violation in the system of
  $K^o$ mesons

abstract:
  In this work there are considered two approaches to the description of $K^o,
\bar K^o$ meson transitions into $K_S (K^o_1)$ mesons at $CP$ violation in weak
interactions. The first approach uses the standard theory of oscillations and
the second approach supposes that ($K_S, K_L$) states which arise at $CP$
violation are normalized but not orthogonal state functions then there arise
interferences between these states but not oscillations. It is necessary to
remark that the available experimental data are in good agreement with the
second approach. So we came to the conclusion that oscillations do not arise at
$CP$ violation in weak interactions in the system of $K^o$ mesons. Only
interference between two - $K_S, K_L$ states takes place there.


title: Evidence for the baryonic decay B0bar --> D0 Lambda Lambdabar

abstract:
  Evidence is presented for the baryonic $B$ meson decay $\bar{B}\rightarrow
D^0 \Lambda \bar{\Lambda}$ based on a data sample of $471 \times 10^6$
$B\bar{B}$ pairs collected with the {\it BABAR} detector at the PEP2 asymmetric
$e^+e^-$ collider located at the SLAC National Accelerator Laboratory. The
branching fraction is determined to be $\mathcal{B}(\bar{B}\rightarrow D^0
\Lambda \bar{\Lambda}) = (9.8^{+2.9}_{-2.6} \pm 1.9)\times 10^{-6}$,
corresponding to a significance of $3.4$ standard deviations including
systematic uncertainties. A search for the related baryonic $B$ meson decay
$\bar{B}\rightarrow D^0 \Sigma^0 \bar{\Lambda}$ with
$\Sigma^0\rightarrow\Lambda\gamma$ is performed and an upper limit
$\mathcal{B}(\bar{B}\rightarrow D^0 \Sigma^0 \bar{\Lambda} + \bar{B}\rightarrow
D^0 \Lambda \bar{\Sigma}^0) < 3.1 \times 10^{-5}$ is determined at $90\%$
confidence level.


title: Continuum thermodynamics of chemically reacting fluid mixtures

abstract:
  We consider viscous, heat conducting mixtures of molecularly miscible
chemical species forming a fluid in which the constituents can undergo chemical
reactions. Assuming a common temperature for all components, we derive a closed
system of partial mass and partial momentum balances plus a mixture balance of
internal energy. This is achieved by careful exploitation of the entropy
principle and requires appropriate definitions of absolute temperature and
chemical potentials, based on an adequate definition of thermal energy
excluding diffusive contributions. The resulting interaction forces split into
a thermo-mechanical and a chemical part, where the former turns out to be
symmetric in case of binary interactions. For chemically reacting systems and
as a new result, the chemical interaction force is a contribution being
non-symmetric outside of chemical equilibrium. The theory also provides a
rigorous derivation of the so-called generalized thermodynamic driving forces,
avoiding the use of approximate solutions to the Boltzmann equations. Moreover,
using an appropriately extended version of the entropy principle and
introducing cross-effects already before closure as entropy invariant couplings
between principal dissipative mechanisms, the Onsager symmetry relations become
a strict consequence. With a classification of the factors in the binary
products of the entropy production according to their parity--instead of the
classical partition into so-called fluxes and driving forces--the apparent
anti-symmetry of certain couplings is thereby also revealed. If the diffusion
velocities are small compared to the speed of sound, the Maxwell-Stefan
equations follow in the case without chemistry, thereby neglecting wave
phenomena in the diffusive motion. This results in a reduced model with only
mass being balanced individually. In the reactive case ...


title: Electric dipole induced universality for Dirac fermions in graphene

abstract:
  We study electric dipole effects for massive Dirac fermions in graphene and
related materials. The dipole potential accomodates towers of infinitely many
bound states exhibiting a universal Efimov-like scaling hierarchy. The dipole
moment determines the number of towers, but there is always at least one tower.
The corresponding eigenstates show a characteristic angular asymmetry,
observable in tunnel spectroscopy. However, charge transport properties
inferred from scattering states are highly isotropic.


title:
"An example of Bautin-type bifurcation in a delay differential
  equation", plus errata

abstract:
  Some errors contained in the author's previous article "An example of
Bautin-type bifurcation in a delay differential equation", JMAA, 329(2007),
777-789, are listed and corrected.
  Original abstract: In a previous paper we gave sufficient conditions for a
system of delay differential equations to present Bautin-type bifurcation. In
the present work we present an example of delay equation that satisfies these
conditions.


title: Upper Bound for Multi-parameter Iterated Commutators

abstract:
  We show that the product BMO space can be characterized by iterated
commutators of a large class of Calder\'on-Zygmund operators. This result
follows from a new proof of boundedness of iterated commutators in terms of the
BMO norm of their symbol functions, using Hyt\"onen's representation theorem of
Calder\'on-Zygmund operators as averages of dyadic shifts. The proof introduces
some new paraproducts which have BMO estimates.


title: Collisionless Magnetic Reconnection in Space Plasmas

abstract:
  Magnetic reconnection requires the violation of the frozen-in condition which
ties gyrating charged particles to the magnetic field inhibiting diffusion.
Ongoing reconnection has been identified in near-Earth space as being
responsible for the excitation of substorms, magnetic storms, generation of
field aligned currents and their consequences, the wealth of auroral phenomena.
Its theoretical understanding is now on the verge of being completed.
Reconnection takes place in thin current sheets. Analytical concepts proceeded
gradually down to the microscopic scale, the scale of the electron skin depth
or inertial length, recognizing that current layers that thin do preferentially
undergo spontaneous reconnection. Thick current layers start reconnecting when
being forced by plasma inflow to thin. For almost half a century the physical
mechanism of reconnection has remained a mystery. Spacecraft in situ
observations in combination with sophisticated numerical simulations in two and
three dimensions recently clarified the mist, finding that reconnection
produces a specific structure of the current layer inside the electron inertial
(also called electron diffusion) region around the reconnection site, the X
line. Onset of reconnection is attributed to pseudo-viscous contributions of
the electron pressure tensor aided by electron inertia and drag, creating a
complicated structured electron current sheet, electric fields, and an electron
exhaust extended along the current layer. We review the general background
theory and recent developments in numerical simulation on collisionless
reconnection. It is impossible to cover the entire field of reconnection in a
short space-limited review. The presentation necessarily remains cursory,
determined by our taste, preferences, and knowledge. Only a small amount of
observations is included in order to support the few selected numerical
simulations.

categories: physics.space-ph astro-ph.HE astro-ph.SR physics.plasm-ph


title: Collaboration in the open-source arena: The WebKit case

abstract:
  In an era of software crisis, the move of firms towards distributed software
development teams is being challenged by emerging collaboration issues. On this
matter, the open-source phenomenon may shed some light, as successful cases on
distributed collaboration in the open-source community have been recurrently
reported. In this paper, we explore the collaboration networks in the WebKit
open-source project, by mining WebKit's source-code version-control-system data
with Social Network Analysis (SNA). Our approach allows us to observe how key
events in the mobile-device industry have affected the WebKit collaboration
network over time. With our findings, we show the explanation power from
network visualizations capturing the collaborative dynamics of a high-networked
software project over time; and highlight the power of the open-source fork
concept as a nexus enabling both features of competition and collaboration. We
also reveal the WebKit project as a valuable research site manifesting the
novel notion of open-coopetition, where rival firms collaborate with
competitors in the open-source community.


title: Capillary levelling of a cylindrical hole in a viscous film

abstract:
  The capillary levelling of cylindrical holes in viscous polystyrene films was
studied using atomic force microscopy as well as quantitative analytical
scaling arguments based on thin film theory and self-similarity. The relaxation
of the holes was shown to consist of two different time regimes: an early
regime where opposing sides of the hole do not interact, and a late regime
where the hole is filling up. For the latter, the self-similar asymptotic
profile was derived analytically and shown to be in excellent agreement with
experimental data. Finally, a binary system of two holes in close proximity was
investigated where the individual holes fill up at early times and coalesce at
longer times.


title:
Measurement of double polarization observables in meson photoproduction
  off the proton with the CBELSA/TAPS experiment

abstract:
  One of the remaining problems within the standard model is to gain a good
understanding of the low energy regime of QCD, where perturbative methods fail.
One key towards a better understanding is baryon spectroscopy. Unfortunately,
in the past most baryon spectroscopy data have been obtained only using $\pi$ N
scattering. To gain access to resonances with small $\pi$ N partial width,
photoproduction experiments, investigating various final states, provide
essential information. In order to extract the contributing resonances, partial
wave analyses need to be performed. Here, the complete experiment is required
to unambiguously determine the contributing amplitudes. This involves the
measurement of carefully chosen single and double polarization observables.
  The Crystal Barrel/TAPS experiment with a longitudinally or transversely
polarized target and an energy tagged, linearly or circularly polarized photon
beam allows the measurement of a large set of polarization observables. Due to
its good energy resolution, high detection efficiency for photons, and the
nearly complete solid angle coverage, it is ideally suited for the measurement
of the photoproduction of neutral mesons decaying into photons.
  Preliminary results for the target asymmetry T, recoil polarization P and the
double polarization observable H are discussed for $\pi^{0}$ and $\eta$
photoproduction off the proton.


title:
Stellar substructures in the solar neighbourhood. III. Kinematic group 2
  in the Geneva-Copenhagen survey

abstract:
  From correlations between orbital parameters, several new coherent groups of
stars were recently identified in the Galactic disc and suggested to correspond
to remnants of disrupted satellites. To reconstruct their origin at least three
main observational parameters - kinematics, chemical composition and age - must
be known. We determine detailed elemental abundances in stars belonging to the
so-called Group 2 of the Geneva-Copenhagen Survey and compare the chemical
composition with Galactic thin- and thick-disc stars, as well as with the
Arcturus and AF06 streams. The aim is to search for chemical signatures that
might give information about the formation history of this kinematic group of
stars. High-resolution spectra were obtained with the FIES spectrograph at the
Nordic Optical Telescope, La Palma, and were analysed with a differential model
atmosphere method. Comparison stars were observed and analysed with the same
method. The average value of [Fe/H] for the 32 stars of Group 2 is -0.42 +-
0.10 dex. The investigated group consists mainly of two 8- and 12-Gyr-old
stellar populations. Abundances of oxygen, alpha-elements, and
r-process-dominated elements are higher than in Galactic thin-disc dwarfs. This
elemental abundance pattern has similar characteristics as that of the Galactic
thick-disc. The similarity in chemical composition of stars in Group 2 with
that in stars of the thick-disc might suggest that their formation histories
are linked. The chemical composition together with the kinematic properties and
ages of stars in the investigated stars provides evidence of their common
origin and possible relation to an ancient merging event. A gas-rich satellite
merger scenario is proposed as the most likely origin. Groups 2 and 3 of the
Geneva-Copenhagen Survey might have originated in the same merging event.


title: On computing the $2$-vertex-connected components of directed graphs

abstract:
  In this paper we consider the problem of computing the $2$-vertex-connected
components ($2$-vccs) of directed graphs. We present two new algorithms for
solving this problem. The first algorithm runs in $O(mn^{2})$ time, the second
in $O(nm)$ time. Furthermore, we show that the old algorithm of Erusalimskii
and Svetlov runs in $O(nm^{2})$ time. In this paper, we investigate the
relationship between $2$-vccs and dominator trees. We also present an algorithm
for computing the $3$-vertex-connected components ($3$-vccs) of a directed
graph in $O(n^{3}m)$ time, and we show that the $k$-vertex-connected components
($k$-vccs) of a directed graph can be computed in $O(mn^{2k-3})$ time. Finally,
we consider three applications of our new algorithms, which are approximation
algorithms for problems that are generalization of the problem of approximating
the smallest $2$-vertex-connected spanning subgraph of $2$-vertex-connected
directed graph.


title: Semiclassical limit of Liouville Field Theory

abstract:
  Liouville Field Theory (LFT for short) is a two dimensional model of random
surfaces, which is for instance involved in $2d$ string theory or in the
description of the fluctuations of metrics in $2d$ Liouville quantum gravity.
This is a probabilistic model that consists in weighting the classical Free
Field action with an interaction term given by the exponential of a Gaussian
multiplicative chaos. The main input of our work is the study of the
semiclassical limit of the theory, which is a prescribed asymptotic regime of
LFT of interest in physics literature (see \cite{witten} and references
therein). We derive exact formulas for the Laplace transform of the Liouville
field in the case of flat metric on the unit disk with Dirichlet boundary
conditions. As a consequence, we prove that the Liouville field concentrates on
the solution of the classical Liouville equation with explicit negative scalar
curvature. We also characterize the leading fluctuations, which are Gaussian
and massive, and establish a large deviation principle. Though considered as an
ansatz in the whole physics literature, it seems that it is the first rigorous
probabilistic derivation of the semiclassical limit of LFT. On the other hand,
we carry out the same analysis when we further weight the Liouville action with
heavy matter operators. This procedure appears when computing the $n$-points
correlation functions of LFT.


title:
Numerical weather prediction or stochastic modeling: an objective
  criterion of choice for the global radiation forecasting

abstract:
  Numerous methods exist and were developed for global radiation forecasting.
The two most popular types are the numerical weather predictions (NWP) and the
predictions using stochastic approaches. We propose to compute a parameter
noted constructed in part from the mutual information which is a quantity that
measures the mutual dependence of two variables. Both of these are calculated
with the objective to establish the more relevant method between NWP and
stochastic models concerning the current problem.


title: Voluminous D2 source for intense cold neutron beam production at the ESS

abstract:
  The development of the flat moderator concept at ESS recently opened up the
possibility that a single flat moderator above the target could serve all the
scattering instruments, that rely on high brightness. This would allow for the
introduction of a fundamentally different moderator below the target for the
complementary needs of certain fundamental physics experiments. To facilitate
experiments depending on the total number of neutrons in a sizable beam, the
option of a voluminous D2 moderator, in a large cross-section extraction guide
is discussed and its neutronic performance is assessed.


title: An Exploration of Physiological Responses to the Native American Flute

abstract:
  This pilot study explored physiological responses to playing and listening to
the Native American flute. Autonomic, electroencephalographic (EEG), and heart
rate variability (HRV) metrics were recorded while participants (N = 15) played
flutes and listened to several styles of music. Flute playing was accompanied
by an 84% increase in HRV (p < .001). EEG theta (4-8 Hz) activity increased
while playing flutes (p = .007) and alpha (8-12 Hz) increased while playing
lower-pitched flutes (p = .009). Increase in alpha from baseline to the flute
playing conditions strongly correlated with experience playing Native American
flutes (r = +.700). Wide-band beta (12-25 Hz) decreased from the silence
conditions when listening to solo Native American flute music (p = .013). The
findings of increased HRV, increasing slow-wave rhythms, and decreased beta
support the hypothesis that Native American flutes, particularly those with
lower pitches, may have a role in music therapy contexts. We conclude that the
Native American flute may merit a more prominent role in music therapy and that
a study of the effects of flute playing on clinical conditions, such as
post-traumatic stress disorder (PTSD), asthma, chronic obstructive pulmonary
disease (COPD), hypertension, anxiety, and major depressive disorder, is
warranted.


title:
Atomic and Electronic Structure of a Rashba $p$-$n$ Junction at the
  BiTeI Surface

abstract:
  The non-centrosymmetric semiconductor BiTeI exhibits two distinct surface
terminations that support spin-split Rashba surface states. Their ambipolarity
can be exploited for creating spin-polarized $p$-$n$ junctions at the
boundaries between domains with different surface terminations. We use scanning
tunneling microscopy/spectroscopy (STM/STS) to locate such junctions and
investigate their atomic and electronic properties. The Te- and I-terminated
surfaces are identified owing to their distinct chemical reactivity, and an
apparent height mismatch of electronic origin. The Rashba surface states are
revealed in the STS spectra by the onset of a van Hove singularity at the band
edge. Eventually, an electronic depletion is found on interfacial Te atoms,
consistent with the formation of a space charge area in typical $p$-$n$
junctions.


title: Integrability of Dirac reduced bi-Hamiltonian equations

abstract:
  First, we give a brief review of the theory of the Lenard-Magri scheme for a
non-local bi-Poisson structure and of the theory of Dirac reduction. These
theories are used in the remainder of the paper to prove integrability of three
hierarchies of bi-Hamiltonian PDE's, obtained by Dirac reduction from some
generalized Drinfeld-Sokolov hierarchies.


title:
Evidence of two different types of short term solar modulation of
  regional surface temperature and cloud

abstract:
  Recent work indicates that 27 day variations in cosmic ray flux during 2007
2009 are phase locked to 27 day variations in cloud and surface temperature at
Shetland. Here we extend the study to other regions including Central England,
US and Australia and to several other annual intervals that exhibit strong 27
day variation in cosmic ray flux and sunspot area. Band pass filtering was used
to obtain 27 day components of daily maximum temperature in each region and 27
day components of cloud variation were determined, in Australia only, from
solar exposure records. When cosmic ray flux is the dominant influence phase
locked variations in surface temperature occur in each of the regions with,
however, in phase or anti phase variation in different regions. Similar phase
locking of 27 day variation in surface temperature to sunspot area variation
occurs when sunspot activity is the dominant influence with indications that
changes from in phase to anti phase variation are linked to flipping of sunspot
activity from one active longitude to another. The 27 day component of cloud in
Australia was phase locked to the 27 day component of temperature in Central
England in two of the intervals studied, 1997 and 2005, indicating the global
nature of the connection between solar disturbance and the lower atmosphere. It
was observed that very large swings in 27 day temperature components are often
correlated with 27 day variation in solar activity.


title: SU(3) quark-antiquark QCD flux tube

abstract:
  We compute the quark-antiquark flux tube for pure gauge SU(3) in space-time 3
+ 1 dimensions. To increase the signal over noise ratio, we apply the improved
multihit and extended smearing techniques. We fit the field densities with an
appropriate ansatz and we observe both the screening of the color fields and
the quantum widening of the flux tube in the mediator plane and in the charge
planes.


title: Universal positive mass theorems

abstract:
  In this paper, we develop a general study of contributions at infinity of
Bochner-Weitzenb\"ock-type formulas on asymptotically flat manifolds, inspired
by Witten's proof of the positive mass theorem. As an application, we show that
similar proofs can be obtained in a much more general setting as any choice of
an irreducible natural bundle and a very large choice of first-order operators
may lead to a positive mass theorem along the same lines if the necessary
curvature conditions are satisfied.


title:
Multidimensional stochastic differential equations with distributional
  drift

abstract:
  This paper investigates a time-dependent multidimensional stochastic
differential equation with drift being a distribution in a suitable class of
Sobolev spaces with negative derivation order. This is done through a careful
analysis of the corresponding Kolmogorov equation whose coefficient is a
distribution.


title: A Near-Optimal Algorithm for Computing Real Roots of Sparse Polynomials

abstract:
  Let $p\in\mathbb{Z}[x]$ be an arbitrary polynomial of degree $n$ with $k$
non-zero integer coefficients of absolute value less than $2^\tau$. In this
paper, we answer the open question whether the real roots of $p$ can be
computed with a number of arithmetic operations over the rational numbers that
is polynomial in the input size of the sparse representation of $p$. More
precisely, we give a deterministic, complete, and certified algorithm that
determines isolating intervals for all real roots of $p$ with
$O(k^3\cdot\log(n\tau)\cdot \log n)$ many exact arithmetic operations over the
rational numbers.
  When using approximate but certified arithmetic, the bit complexity of our
algorithm is bounded by $\tilde{O}(k^4\cdot n\tau)$, where $\tilde{O}(\cdot)$
means that we ignore logarithmic. Hence, for sufficiently sparse polynomials
(i.e. $k=O(\log^c (n\tau))$ for a positive constant $c$), the bit complexity is
$\tilde{O}(n\tau)$. We also prove that the latter bound is optimal up to
logarithmic factors.


title:
Can new heavy gauge bosons be observed in ultra-high energy cosmic
  neutrino events?

abstract:
  A wide range of models beyond the Standard Model predict charged and neutral
resonances, generically called $W'$- and $Z'$-bosons, respectively. In this
paper we study the impact of such resonances on the deep inelastic scattering
of ultra-high energy neutrinos as well as on the resonant charged current
$\bar\nu_e e^-$ scattering (Glashow resonance). We find that the effects of
such resonances can not be observed with the Pierre Auger Observatory or any
foreseeable upgrade of it.


title:
Efficient Background Modeling Based on Sparse Representation and Outlier
  Iterative Removal

abstract:
  Background modeling is a critical component for various vision-based
applications. Most traditional methods tend to be inefficient when solving
large-scale problems. In this paper, we introduce sparse representation into
the task of large scale stable background modeling, and reduce the video size
by exploring its 'discriminative' frames. A cyclic iteration process is then
proposed to extract the background from the discriminative frame set. The two
parts combine to form our Sparse Outlier Iterative Removal (SOIR) algorithm.
The algorithm operates in tensor space to obey the natural data structure of
videos. Experimental results show that a few discriminative frames determine
the performance of the background extraction. Further, SOIR can achieve high
accuracy and high speed simultaneously when dealing with real video sequences.
Thus, SOIR has an advantage in solving large-scale tasks.


title: Exponential stability of nonhomogeneous matrix-valued Markovian chains

abstract:
  In this paper, we characterize the stability of matrix-valued Markovian
chains by periodic data.


title: Ring Paxos: High-Throughput Atomic Broadcast

abstract:
  Atomic broadcast is an important communication primitive often used to
implement state-machine replication. Despite the large number of atomic
broadcast algorithms proposed in the literature, few papers have discussed how
to turn these algorithms into efficient executable protocols. This paper
focuses on a class of atomic broadcast algorithms based on Paxos, with its
corresponding desirable properties: safety under asynchrony assumptions,
liveness under weak synchrony assumptions, and resiliency-optimality. The paper
presents two protocols, M-Ring Paxos and U-Ring Paxos, derived from Paxos. The
protocols inherit the properties of Paxos and can be implemented very
efficiently. We report a detailed performance analysis of M-Ring Paxos and
U-Ring Paxos and compare them to other atomic broadcast protocols.


title: Joint Planck and WMAP CMB Map Reconstruction

abstract:
  We present a novel estimate of the cosmological microwave background (CMB)
map by combining the two latest full-sky microwave surveys: WMAP nine-year and
Planck PR1. The joint processing benefits from a recently introduced component
separation method coined "local-generalized morphological component analysis''
(LGMCA) based on the sparse distribution of the foregrounds in the wavelet
domain. The proposed estimation procedure takes advantage of the IRIS 100
micron as an extra observation on the galactic center for enhanced dust
removal. We show that this new CMB map presents several interesting aspects: i)
it is a full sky map without using any inpainting or interpolating method, ii)
foreground contamination is very low, iii) the Galactic center is very clean,
with especially low dust contamination as measured by the cross-correlation
between the estimated CMB map and the IRIS 100 micron map, and iv) it is free
of thermal SZ contamination.


title: Tiling Vertices and the Spacing Distribution of their Radial Projection

abstract:
  The Fourier-based diffraction approach is an established method to extract
order and symmetry propertiesfrom a given point set. We want to investigate a
different method for planar sets which works in direct spaceand relies on
reduction of the point set information to its angular component relative to a
chosen referenceframe. The object of interest is the distribution of the
spacings of these angular components, which can for instance beencoded as a
density function on $\Real_{+}$. In fact, this \emph{radial projection} method
is not entirely new, andthe most natural choice of a point set, the integer
lattice $\Integer^2$, is already well understood. We focus on the radial
projection of aperiodic point sets and study the relation between the
resultingdistribution and properties of the underlying tiling, like symmetry,
order and the algebraic type of theinflation multiplier.


title:
Intrinsic alignments in the cross-correlation of cosmic shear and CMB
  weak lensing

abstract:
  We demonstrate that the intrinsic alignment of galaxies with large-scale
tidal fields sources an extra contribution to the recently-detected
cross-correlation of galaxy shear and weak lensing of the microwave background.
The extra term is the analogy of the 'GI' term in standard cosmic shear
studies, and results in a reduction in the amplitude of the cross-correlation.
We compute the intrinsic alignment contribution in linear and non-linear
theory, and show that it can be at roughly the 15% level for the CFHT Stripe 82
redshift distribution, if the canonical amplitude of intrinsic alignments is
assumed. The new term can therefore potentially reconcile the apparently low
value of the measured cross-correlation with standard LCDM. We discuss various
small-scale effects in the signal and the dependence on the source redshift
distribution. We discuss the exciting possibility of self-calibrating intrinsic
alignments with a joint analysis of cosmic shear and weak lensing of the
microwave background


title:
A characterization of the symmetric steady water waves in terms of the
  underlying flow

abstract:
  In this paper we present a characterization of the symmetric rotational
periodic gravity water waves of finite depth and without stagnation points in
terms of the underlying flow. Namely, we show that such a wave is symmetric and
has a single crest and trough per period if and only if there exists a vertical
line within the fluid domain such that all the fluid particles located on that
line minimize there simultaneously their distance to the fluid bed as they move
about. Our analysis uses the moving plane method, sharp elliptic maximum
principles, and the principle of analytic continuation.


title: A Brief Review on Models for Performance Evaluation in DSS Architecture

abstract:
  Distributed Software Systems are used these days by many people in the real
time operations and modern enterprise applications. One of the most important
and essential attributes of measurements for the quality of service of
distributed software is performance. Performance models can be employed at
early stages of the software development cycle to characterize the quantitative
behavior of software systems. In this research, performance models based on
fuzzy logic approach, queuing network approach and Petri net approach have been
reviewed briefly. One of the most common ways in performance analysis of
distributed software systems is translating the UML diagrams to mathematical
modeling languages for the description of distributed systems such as queuing
networks or Petri nets. In this paper, some of these approaches are reviewed
briefly. Attributes which are used for performance modeling in the literature
are mostly machine based. On the other hand, end users and client parameters
for performance evaluation are not covered extensively. In this way, future
research could be based on developing hybrid models to capture user decision
variables which make system performance evaluation more user driven.


title: Pros and cons of swimming in a noisy environment

abstract:
  The problem of optimal microscopic swimming in a noisy environment is
analyzed. A simplified model in which propulsion is generated by the relative
motion of three spheres connected by immaterial links has been considered. We
show that an optimized noisy microswimmer requires less power for propulsion
(on the average), than an optimal noiseless counterpart, migrating with
identical mean velocity and swimming stroke amplitude. We also show that noise
can be used to overcome some of the limitations of the scallop theorem, and
have a swimmer that is able to propel itself with control over just one degree
of freedom.


title: New Approaches to Website Fingerprinting Defenses

abstract:
  Website fingerprinting attacks enable an adversary to infer which website a
victim is visiting, even if the victim uses an encrypting proxy, such as Tor.
Previous work has shown that all proposed defenses against website
fingerprinting attacks are ineffective.
  This paper advances the study of website fingerprinting attacks and defenses
in two ways. First, we develop bounds on the trade-off between security and
bandwidth overhead that any fingerprinting defense scheme can achieve. This
enables us to compare schemes with different security/overhead trade-offs by
comparing how close they are to the lower bound. We then refine, implement, and
evaluate the Congestion Sensitive BuFLO scheme outlined by Cai, et al.
CS-BuFLO, which is based on the provably-secure BuFLO defense proposed by Dyer,
et al., was not fully-specified by Cai, et al, but has nonetheless attracted
the attention of the Tor developers. Our experiments find that CS-BuFLO has
high overhead (around 2.3-2.8x) but can get 6x closer to the bandwidth/security
trade-off lower bound than Tor or plain SSH.


title: A Unified Approach for Network Information Theory

abstract:
  In this paper, we take a unified approach for network information theory and
prove a coding theorem, which can recover most of the achievability results in
network information theory that are based on random coding. The final
single-letter expression has a very simple form, which was made possible by
many novel elements such as a unified framework that represents various network
problems in a simple and unified way, a unified coding strategy that consists
of a few basic ingredients but can emulate many known coding techniques if
needed, and new proof techniques beyond the use of standard covering and
packing lemmas. For example, in our framework, sources, channels, states and
side information are treated in a unified way and various constraints such as
cost and distortion constraints are unified as a single joint-typicality
constraint.
  Our theorem can be useful in proving many new achievability results easily
and in some cases gives simpler rate expressions than those obtained using
conventional approaches. Furthermore, our unified coding can strictly
outperform existing schemes. For example, we obtain a generalized
decode-compress-amplify-and-forward bound as a simple corollary of our main
theorem and show it strictly outperforms previously known coding schemes. Using
our unified framework, we formally define and characterize three types of
network duality based on channel input-output reversal and network flow
reversal combined with packing-covering duality.


title: Matrix factorization with Binary Components

abstract:
  Motivated by an application in computational biology, we consider low-rank
matrix factorization with $\{0,1\}$-constraints on one of the factors and
optionally convex constraints on the second one. In addition to the
non-convexity shared with other matrix factorization schemes, our problem is
further complicated by a combinatorial constraint set of size $2^{m \cdot r}$,
where $m$ is the dimension of the data points and $r$ the rank of the
factorization. Despite apparent intractability, we provide - in the line of
recent work on non-negative matrix factorization by Arora et al. (2012) - an
algorithm that provably recovers the underlying factorization in the exact case
with $O(m r 2^r + mnr + r^2 n)$ operations for $n$ datapoints. To obtain this
result, we use theory around the Littlewood-Offord lemma from combinatorics.


title:
Cryptanalysis of McEliece Cryptosystem Based on Algebraic Geometry Codes
  and their subcodes

abstract:
  We give polynomial time attacks on the McEliece public key cryptosystem based
either on algebraic geometry (AG) codes or on small codimensional subcodes of
AG codes. These attacks consist in the blind reconstruction either of an Error
Correcting Pair (ECP), or an Error Correcting Array (ECA) from the single data
of an arbitrary generator matrix of a code. An ECP provides a decoding
algorithm that corrects up to $\frac{d^*-1-g}{2}$ errors, where $d^*$ denotes
the designed distance and $g$ denotes the genus of the corresponding curve,
while with an ECA the decoding algorithm corrects up to $\frac{d^*-1}{2}$
errors. Roughly speaking, for a public code of length $n$ over $\mathbb F_q$,
these attacks run in $O(n^4\log (n))$ operations in $\mathbb F_q$ for the
reconstruction of an ECP and $O(n^5)$ operations for the reconstruction of an
ECA. A probabilistic shortcut allows to reduce the complexities respectively to
$O(n^{3+\varepsilon} \log (n))$ and $O(n^{4+\varepsilon})$. Compared to the
previous known attack due to Faure and Minder, our attack is efficient on codes
from curves of arbitrary genus. Furthermore, we investigate how far these
methods apply to subcodes of AG codes.


title: On Isometric Embeddings into Anti-de Sitter Space-times

abstract:
  We show that any metric on $S^2$ with Gauss curvature $K \geq -\kappa$ admits
a $C^{1,1}$-isometric embedding into the hyperbolic space with sectional
curvature $-\kappa$. We also give a sufficient condition for a metric on $S^2$
to be isometrically embedded into anti-de Sitter spacetime with the prescribed
cosmological time function.


title: Band gaps in incommensurable graphene on hexagonal boron nitride

abstract:
  Devising ways of opening a band gap in graphene to make charge-carrier masses
finite is essential for many applications. Recent experiments with graphene on
hexagonal boron nitride (h-BN) offer tantalizing hints that the weak
interaction with the substrate is sufficient to open a gap, in contradiction of
earlier findings. Using many-body perturbation theory, we find that the small
observed gap is what remains after a much larger underlying quasiparticle gap
is suppressed by incommensurability. The sensitivity of this suppression to a
small modulation of the distance separating graphene from the substrate
suggests ways of exposing the larger underlying gap.


title:
Justification of the single-mode approximation for a finite-duration
  laser pulse interacting with an electron

abstract:
  The interaction Hamiltonian of an electron and a quasi-monochromatic pulse of
a strong quantized electromagnetic field is examined. Canonical transformations
of the field variables are found that allow the division of the system's
Hamiltonian in two parts. The first one describes the interaction between an
electron and a single collective mode of the field. The properties of this mode
are defined by the superposition of the modes corresponding to the pulse wave
packet. The second part describes the field fluctuations relatively to the
collective mode. The field intensity, pulse duration and transversal spread are
estimated for which a single-mode approximation can be used for the system's
description.


title:
Simultaneous optical and near-infrared linear spectropolarimetry of the
  earthshine

abstract:
  Aims: We aim to extend our current observational understanding of the
integrated planet Earth spectropolarimetry from the optical to the
near-infrared wavelengths. Major biomarkers like O$_{\rm 2}$ and water vapor
are strong flux absorbents in the Earth atmosphere and some linear polarization
of the reflected stellar light is expected to occur at these wavelengths.
  Methods: Simultaneous optical ($0.4-0.9$ $\mu$m) and near-infrared ($0.9-2.3$
$\mu$m) linear spectropolarimetric data of the earthshine were acquired by
observing the nightside of the waxing Moon. The data have sufficient spectral
resolution (2.51 nm in the optical, and 1.83 and 2.91 nm in the near-infrared)
to resolve major molecular species present in the Earth atmosphere.
  Results: We find the highest values of linear polarization ($\ge 10\%$) at
the bluest wavelengths, which agrees with the literature. Linear polarization
intensity steadily decreases towards red wavelengths reaching a nearly flat
value beyond $\sim$0.8 $\mu$m. In the near-infrared, we measured a polarization
degree of $\sim4.5 \%$ for the continuum. We report the detection of molecular
features due to O$_{2}$ at $0.760, 1.25 \mu$m and H$_{2}$O at 0.653$-$0.725
$\mu$m, 0.780$-$0.825 $\mu$m, 0.93 and 1.12 $\mu$m in the spectropolarimetric
data; most of them show high linear polarimetry degrees above the continuum. In
particular, the broad H$_{2}$O 1.12 $\mu$m band displays a polarimetric
intensity as high as that of the blue optical. These features may become a
powerful tool to characterize Earth-like planets in polarized light.


title: The Effective Solving of the Tasks from NP by a Quantum Computer

abstract:
  The new model of quantum computation is proposed, for which an effective
algorithm of solving any task in NP is described. The work is based and
inspired be the Grover's algorithm for solving NP-tasks with quadratic speedup
compared to the classical computation model. The provided model and algorithm
exhibit the exponential speedup over that described by Grover.


title: Multivariable theory of droplet nucleation in a single-component vapor

abstract:
  The multivariable theory of nucleation [N. V. Alekseechkin, J. Chem. Phys.
124, 124512 (2006)] is applied to the droplet nucleation in a supersaturated
single-component vapor; the droplet volume V, temperature T, and volume change
rate U=V_dot are the variables of the theory. A new approach based on
macroscopic kinetics is developed for the droplet evolution and results in the
derived equations for U_dot, V_dot, and T_dot. It is shown that there is no the
viscosity effect in the employed ideal gas approximation, so the variable U can
be omitted. The nonisothermal effect (the discrepancy between the actual and
isothermal nucleation rates) earlier studied numerically is analytically
examined here. The calculated steady state distribution function of droplets
shows their average overheating relatively the vapor temperature. An inert
background gas is shown to diminish the nonisothermal effect in comparison with
a pure vapor case.


title: On Plane Curves with Double and Triple Points

abstract:
  We describe in simple geometric terms the Hodge filtration on the cohomology
groups of the complement U in the projective plane of a curve C with ordinary
double and triple points. Relations to Milnor algebra, syzygies of the Jacobian
ideal and pole order filtration on the second cohomology of U are given.


title: Designing Gabor windows using convex optimization

abstract:
  Redundant Gabor frames admit an infinite number of dual frames, yet only the
canonical dual Gabor system, constructed from the minimal l2-norm dual window,
is widely used. This window function however, might lack desirable properties,
e.g. good time-frequency concentration, small support or smoothness. We employ
convex optimization methods to design dual windows satisfying the Wexler-Raz
equations and optimizing various constraints. Numerical experiments suggest
that alternate dual windows with considerably improved features can be found.


title: Chiral symmetry breaking and the generation of light hadron masses

abstract:
  A quantitative study of the effects of dynamical chiral symmetry breaking on
the mass generation of the low-lying hadrons in a dynamical lattice QCD
simulation is presented. The evolution of light hadron masses upon increasing
the number of low-lying Dirac operator eigenmodes in the quark propagators is
confronted with the hadron masses obtained upon removal of such low-lying
eigenmodes from standard full quark propagators. The low-lying chiral symmetry
breaking modes provide roughly two third of the nucleon and $\rho$ masses,
while the $a_1$ mass is affected to a much smaller degree.


title:
Chemo-dynamical deuterium fractionation in the early solar nebula: The
  origin of water on Earth and in asteroids and comets

abstract:
  Formation and evolution of water in the Solar System and the origin of water
on Earth constitute one of the most interesting questions in astronomy. The
prevailing hypothesis for the origin of water on Earth is by delivery through
water-rich small Solar system bodies. In this paper, the isotopic and chemical
evolution of water during the early history of the solar nebula, before the
onset of planetesimal formation, is studied. A gas-grain chemical model that
includes multiply-deuterated species and nuclear spin-states is combined with a
steady-state solar nebula model. To calculate initial abundances, we simulated
1 Myr of evolution of a cold and dark TMC1-like prestellar core. Two
time-dependent chemical models of the solar nebula are calculated over 1 Myr:
(1) a laminar model and (2) a model with 2D turbulent mixing. We find that the
radial outward increase of the H2O D/H ratio is shallower in the
chemo-dynamical nebular model compared to the laminar model. This is related to
more efficient de-fractionation of HDO via rapid gas-phase processes, as the 2D
mixing model allows the water ice to be transported either inward and thermally
evaporated or upward and photodesorbed. The laminar model shows the Earth water
D/H ratio at r ~<2.5 AU, while for the 2D chemo-dynamical model this zone is
larger, r ~<9 AU. Similarly, the water D/H ratios representative of the
Oort-family comets, ~2.5-10 x 10-4, are achieved within ~2-6 AU and ~2-20 AU in
the laminar and the 2D model, respectively. We find that with regards to the
water isotopic composition and the origin of the comets, the mixing model seems
to be favored over the laminar model.


title:
On involutions in extremal self-dual codes and the dual distance of semi
  self-dual codes

abstract:
  A classical result of Conway and Pless is that a natural projection of the
fixed code of an automorphism of odd prime order of a self-dual binary linear
code is self-dual. In this paper we prove that the same holds for involutions
under some (quite strong) conditions on the codes. In order to prove it, we
introduce a new family of binary codes: the semi self-dual codes. A binary
self-orthogonal code is called semi self-dual if it contains the all-ones
vector and is of codimension 2 in its dual code. We prove upper bounds on the
dual distance of semi self-dual codes. As an application we get the following:
let C be an extremal self-dual binary linear code of length 24m and s in Aut(C)
be a fixed point free automorphism of order 2. If m is odd or if m=2k with
binom{5k-1}{k-1} odd then C is a free F_2<s>-module. This result has quite
strong consequences on the structure of the automorphism group of such codes.


title: Introduction to categorification

abstract:
  These are the notes for a two-week mini-course given at a winter school in
January 2014 as part of the thematic semester New Directions in Lie Theory at
the Centre de Recherches Math\'ematiques in Montr\'eal. The goal of the course
was to give an overview of the idea of categorification, with an emphasis on
some examples where explicit computation is possible with minimal background.
The notes begin with a very brief review of the representation theory of
associative algebras, before introducing the concept of weak categorification
with some simple examples. It then proceeds to a discussion of more
sophisticated examples of categorification, including a weak categorification
of the polynomial representation of the Weyl group and the Fock space
representation of the Heisenberg algebra. The notes conclude with a discussion
of strong categorification and a brief overview of some further directions in
the field.


title: Equilibrium configurations of nematic liquid crystals on a torus

abstract:
  The topology and the geometry of a surface play a fundamental role in
determining the equilibrium configurations of thin films of liquid crystals. We
propose here a theoretical analysis of a recently introduced surface Frank
energy, in the case of two-dimensional nematic liquid crystals coating a
toroidal particle. Our aim is to show how a different modeling of the effect of
extrinsic curvature acts as a selection principle among equilibria of the
classical energy, and how new configurations emerge. In particular, our
analysis predicts the existence of new stable equilibria with complex windings.


title:
Constant Compositions in the Sphere Packing Bound for Classical-Quantum
  Channels

abstract:
  The sphere packing bound, in the form given by Shannon, Gallager and
Berlekamp, was recently extended to classical-quantum channels, and it was
shown that this creates a natural setting for combining probabilistic
approaches with some combinatorial ones such as the Lov\'asz theta function. In
this paper, we extend the study to the case of constant composition codes. We
first extend the sphere packing bound for classical-quantum channels to this
case, and we then show that the obtained result is related to a variation of
the Lov\'asz theta function studied by Marton. We then propose a further
extension to the case of varying channels and codewords with a constant
conditional composition given a particular sequence. This extension is then
applied to auxiliary channels to deduce a bound which can be interpreted as an
extension of the Elias bound.


title: Associated Graphs of Certain Arithmetic IASI Graphs

abstract:
  An integer additive set-indexer is defined as an injective function
$f:V(G)\rightarrow 2^{\mathbb{N}_0}$ such that the induced function $f^+:E(G)
\rightarrow 2^{\mathbb{N}_0}$ defined by $f^+ (uv) = f(u)+ f(v)$ is also
injective. A graph $G$ which admits an IASI is called an IASI graph. An
arithmetic integer additive set-indexer is an integer additive set-indexer $f$,
under which the set-labels of all elements of a given graph $G$ are arithmetic
progressions. In this paper, we discuss about admissibility of arithmetic
integer additive set-indexers by certain associated graphs of the given graph
$G$, like line graph, total graph, etc.


title: Coherent XUV generation driven by sharp metal tips photoemission

abstract:
  It was already experimentally demonstrated that high-energy electrons can be
generated using metal nanotips as active media. In addition, it has been
theoretically proven that the high-energy tail of the photoemitted electrons is
intrinsically linked to the recollision phenomenon. Through this recollision
process it is also possible to convert the energy gained by the laser-emitted
electron in the continuum in a coherent XUV photon. It means the emission of
harmonic radiation appears to be feasible, although it has not been
experimentally demonstrated hitherto till now. In this paper, we employ a
quantum mechanical approach to model the electron dipole moment including both
the laser experimental conditions and the bulk matter properties and predict is
possible to generate coherent UV and XUV radiation using metal nanotips as
sources. Our quantum mechanical results are fully supported by their classical
counterparts.


title: On the monodromy of Milnor fibers of hyperplane arrangements

abstract:
  We describe a general setting where the monodromy action on the first
cohomology group of the Milnor fiber of a hyperplane arrangement is the
identity.


title: Mass concentration in a nonlocal model of clonal selection

abstract:
  Self-renewal is a constitutive property of stem cells. Testing the cancer
stem cell hypothesis requires investigation of the impact of self-renewal on
cancer expansion. To understand better this impact, we propose a mathematical
model describing dynamics of a continuum of cell clones structured by the
self-renewal potential. The model is an extension of the finite
multi-compartment models of interactions between normal and cancer cells in
acute leukemias. It takes a form of a system of integro-differential equations
with a nonlinear and nonlocal coupling, which describes regulatory feedback
loops in cell proliferation and differentiation process. We show that such
coupling leads to mass concentration in points corresponding to maximum of the
self-renewal potential and the model solutions tend asymptotically to a linear
combination of Dirac measures. Furthermore, using a Lyapunov function
constructed for a finite dimensional counterpart of the model, we prove that
the total mass of the solution converges to a globally stable equilibrium.
Additionally, we show stability of the model in space of positive Radon
measures equipped with flat metric. The analytical results are illustrated by
numerical simulations.