title:
Differences of the Solar Magnetic Activity Signature in Velocity and
  Intensity Helioseismic Observations

abstract:
  The high-quality, full-disk helioseismic observations continuously collected
by the spectrophotometer GOLF and the three photometers VIRGO/SPMs onboard the
SoHO spacecraft for 17 years now (since April 11, 1996, apart from the SoHO
"vacations") are absolutely unique for the study of the interior of the Sun and
its variability with magnetic activity. Here, we look at the differences in the
low-degree oscillation p-mode frequencies between radial velocity and intensity
measurements taking into account all the known features of the p-mode profiles
(e.g., the opposite peak asymmetry), and of the power spectrum (e.g., the
presence of the higher degrees l= 4 and 5 in the signal). We show that the
intensity frequencies are higher than the velocity frequencies during the solar
cycle with a clear temporal dependence. The response between the individual
angular degrees is also different. Time delays are observed between the
temporal variations in GOLF and VIRGO frequencies. Such analysis is important
in order to put new constraints and to better understand the mechanisms
responsible for the temporal variations of the oscillation frequencies with the
solar magnetic activity as well as their height dependences in the solar
atmosphere. It is also important for the study of the stellar magnetic activity
using asteroseismic data.


title:
Pressure-induced Enhancement of Superconductivity in BiS$_2$-layered
  LaO$_{1-x}$F$_x$BiS$_2$

abstract:
  The newly discovered BiS$_2$-based LaO$_{1-x}$F$_{x}$BiS$_2$ ($x$=0.5)
becomes superconductive at $T_c$=2.5 K. Electrical resistivity and
magnetization measurements are performed under pressure to determine the
pressure dependence of the superconducting transition temperature $T_c$. We
observe that $T_c$ abruptly increases from 2.5 K to 10.7 K at a pressure of 0.7
GPa. According to high-pressure X-ray diffraction measurements, a structural
phase transition from a tetragonal phase ($P$4/$nmm$) to a monoclinic phase
($P$2$_1/m$) also occurs at around $\sim$ 1 GPa. We consider that a
pressure-induced enhancement of superconductivity is caused by the structural
phase transition.


title:
Optimal Distributed Controller Design with Communication Delays:
  Application to Vehicle Formations

abstract:
  This paper develops a controller synthesis algorithm for distributed LQG
control problems under output feedback. We consider a system consisting of
three interconnected linear subsystems with a delayed information sharing
structure. While the state-feedback case of this problem has previously been
solved, the extension to output-feedback is nontrivial, as the classical
separation principle fails. To find the optimal solution, the controller is
decomposed into two independent components. One is delayed centralized LQR, and
the other is the sum of correction terms based on additional local information.
Explicit discrete-time equations are derived whose solutions are the gains of
the optimal controller.


title: Design of light concentrators for Cherenkov telescope observatories

abstract:
  The Cherenkov Telescope Array (CTA) will be the largest cosmic gamma ray
detector ever built in the world. It will be installed at two different sites
in the North and South hemispheres and should be operational for about 30
years. In order to cover the desired energy range, the CTA is composed of
typically 50-100 collecting telescopes of various sizes (from 6 to 24-m
diameters). Most of them are equipped with a focal plane camera consisting of
1500 to 2000 Photomultipliers (PM) equipped with light concentrating optics,
whose double function is to maximize the amount of Cherenkov light detected by
the photo-sensors, and to block any stray light originating from the
terrestrial environment. Two different optical solutions have been designed,
respectively based on a Compound Parabolic Concentrator (CPC), and on a purely
dioptric concentrating lens. In this communication are described the technical
specifications, optical designs and performance of the different solutions
envisioned for all these light concentrators. The current status of their
prototyping activities is also given.


title:
Controlling the Velocities and Number of Emitted Particles in the
  Tunneling to Open Space Dynamics

abstract:
  A scheme to control the many-boson tunneling process to open space is derived
and demonstrated. The number of ejected particles and their velocities can be
controlled by two parameters, the threshold of the potential and the
interparticle interaction. Since these parameters are fully under experimental
control, this is also the case for the number of ejected particles and their
emission spectrum. The process of tunneling to open space can hence be used,
for example, for the quantum simulation of complicated tunneling ionization
processes and atom lasers. To understand the many-body tunneling process, a
generalization of the model introduced in [Proc. Natl. Acad. Sci. USA, 109,
13521 (2012)] for tunneling in the absence of a threshold is put forward and
proven to apply for systems with a non-zero threshold value. It is demonstrated
that the model is applicable for general interparticle interaction strengths,
particle numbers and threshold values. The model constructs the many-body
process from single-particle emission processes. The rates and emission momenta
of the single-particle processes are determined by the chemical potentials and
energy differences to the threshold value of the potential for systems with
different particle numbers. The chemical potentials and these energy
differences depend on the interparticle interaction. Both the number of
confined particles and their rate of emission thus allow for a control by the
manipulation of the interparticle interaction and the threshold. Numerically
exact results for two, three and one hundred bosons are shown and discussed.
The devised control scheme for the many-body tunneling process performs very
well for the dynamics of the momentum density, the correlations, the coherence
and of the final state, i.e., the number of particles that remain confined in
the potential.


title: Joining and splitting the quantum states of photons

abstract:
  A photonic process named as "quantum state joining" has been recently
experimentally demonstrated [C. Vitelli et al., Nature Photon. 7, 521 (2013)]
that corresponds to the transfer of the internal two-dimensional quantum states
of two input photons, i.e., two photonic qubits, into the four-dimensional
quantum state of a single photon, i.e., a photonic ququart. A scheme for the
inverse process, namely "quantum state splitting", has also been theoretically
proposed. Both processes can be iterated in a cascaded layout, to obtain the
joining and/or splitting of more than two qubits, thus leading to a general
scheme for varying the number of photons in the system while preserving its
total quantum state, or quantum information content. Here, we revisit these
processes from a theoretical point of view. After casting the theory of the
joining and splitting processes in the more general photon occupation number
notation, we introduce some modified schemes that are in principle unitary (not
considering the implementation of the CNOT gates) and do not require projection
and feed-forward steps. This can be particularly important in the quantum state
splitting case, to obtain a scheme that does not rely on postselection.
Moreover, we formally prove that the quantum joining of two photon states with
linear optics requires the use of at least one ancilla photon. This is somewhat
unexpected, given that the demonstrated joining scheme involves the sequential
application of two CNOT quantum gates, for which a linear optical scheme with
just two photons and postselection is known to exist. Finally we explore the
relationship between the joining scheme and the generation of clusters of
multi-particle entangled states involving more than one qubit per particle.


title:
Constraint driven condensation in large fluctuations of linear
  statistics

abstract:
  Condensation is the phenomenon whereby one of a sum of random variables
contributes a finite fraction to the sum. It is manifested as an aggregation
phenomenon in diverse physical systems such as coalescence in granular media,
jamming in traffic and gelation in networks. We show here that the same
condensation scenario, which normally happens only if the underlying
probability distribution has tails heavier than exponential, can occur for
light-tailed distributions in the presence of additional constraints. We
demonstrate this phenomenon on the sample variance, whose probability
distribution conditioned on the particular value of the sample mean undergoes a
phase transition. The transition is manifested by a change in behavior of the
large deviation rate function.


title: Evidence of non-thermal X-ray emission from HH 80

abstract:
  Protostellar jets appear at all stages of star formation when the accretion
process is still at work. Jets travel at velocities of hundreds of km/s,
creating strong shocks when interacting with interstellar medium. Several cases
of jets have been detected in X-rays, typically showing soft emission. For the
first time, we report evidence of hard X-ray emission possibly related to
non-thermal processes not explained by previous models of the post-shock
emission predicted in the jet/ambient interaction scenario. HH 80 is located at
the south head of the jet associated to the massive protostar IRAS 18162-2048.
It shows soft and hard X-ray emission in regions that are spatially separated,
with the soft X-ray emission region situated behind the region of hard X-ray
emission. We propose a scenario for HH 80 where soft X-ray emission is
associated to thermal processes from the interaction of the jet with denser
ambient matter and the hard X-ray emission is produced by synchrotron radiation
at the front shock.


title:
A Diagrammer's Note on Superconducting Fluctuation Transport for
  Beginners: Supplement. Jonson-Mahan Transmutation

abstract:
  The Ward identity for the heat current vertex is illustrated in terms of
Feynman diagrams. The Jonson-Mahan transmutation, the way how the kinetic
energy at the heat current vertex for the free propagator is transmuted into
the frequency for the full propagator, is the key of the illustration.


title:
Scale-free property for degrees and weights in an N-interactions random
  graph model

abstract:
  A general random graph evolution mechanism is defined. The evolution is a
combination of the preferential attachment model and the interaction of N
vertices (N>=3). A vertex in the graph is characterized by its degree and its
weight. The weight of a given vertex is the number of the interactions of the
vertex. The asymptotic behaviour of the graph is studied. Scale-free properties
both for the degrees and the weights are proved. It turns out that any exponent
in (2,\infty) can be achieved. The proofs are based on discrete time martingale
theory.


title: Optimal scales in weighted networks

abstract:
  The analysis of networks characterized by links with heterogeneous intensity
or weight suffers from two long-standing problems of arbitrariness. On one
hand, the definitions of topological properties introduced for binary graphs
can be generalized in non-unique ways to weighted networks. On the other hand,
even when a definition is given, there is no natural choice of the (optimal)
scale of link intensities (e.g. the money unit in economic networks). Here we
show that these two seemingly independent problems can be regarded as
intimately related, and propose a common solution to both. Using a formalism
that we recently proposed in order to map a weighted network to an ensemble of
binary graphs, we introduce an information-theoretic approach leading to the
least biased generalization of binary properties to weighted networks, and at
the same time fixing the optimal scale of link intensities. We illustrate our
method on various social and economic networks.

categories: physics.data-an cond-mat.dis-nn cond-mat.stat-mech cs.SI


title: Parametric instability in scalar gravitational fields

abstract:
  We present a brief review on a new dynamical mechanism for a strong field
effect in scalar tensor theory. Starting with a summary of the essential
features of the theory and subsequent work by several authors, we analytically
investigate the parametric excitation of a scalar gravitational field in a
spherically symmetric radially pulsating neutron star.


title:
A q-parameter bound for particle spectra based on black hole
  thermodynamics with R\'enyi-entropy

abstract:
  By regarding the Hawking-Bekenstein entropy of Schwarzschild black hole
horizons as a non-extensive Tsallis entropy, its formal logarithm, the R\'enyi
entropy, is considered. The resulting temperature - horizon-radius relation has
the same form as the one obtained from a 3+1-dimensional black hole in anti-de
Sitter space using the original entropy formula. In both cases the temperature
has a minimum. A semi-classical estimate of the horizon radius at this minimum
leads to a Bekenstein bound for the q-parameter in the R\'enyi entropy of micro
black holes, (q >= 1 + 2/pi^2), which is surprisingly close to fitted
q-parameters of cosmic ray spectra and power-law distribution of quarks
coalescing to hadrons in high energy accelerator experiments.


title: Product set phenomena for countable groups

abstract:
  We develop in this paper general techniques to analyze local combinatorial
structures in product sets of two subsets of a countable group which are
"large" with respect to certain classes of (not necessarily invariant) means on
the group. As applications of our methods, we extend and quantify a series of
recent results by Jin, Bergelson-Furstenberg-Weiss, Beiglb\"ock-Bergelson-Fish,
Griesmer and DiNasso-Lupini to general countable groups.


title:
The space-fractional diffusion-advection equation: Analytical solutions
  and critical assessment of numerical solutions

abstract:
  The present work provides a critical assessment of numerical solutions of the
space-fractional diffusion-advection equation, which is of high significance
for applications in various natural sciences. In view of the fact that, in
contrast to the case of normal (Gaussian) diffusion, no standard methods and
corresponding numerical codes for anomalous diffusion problems have been
established yet, it is of importance to critically assess the accuracy and
performance of existing approaches. Three numerical methods, namely a
finite-difference method, the so-called matrix transfer technique, and a
Monte-Carlo method based on the solution of stochastic differential equations,
are analyzed and compared by applying them to three selected test problems for
which analytical or semi-analytical solutions were known or are newly derived.
The accuracy and performance differences are critically discussed with the
result that the use of stochastic differential equations appears to be
advantageous.


title: Flat bundles and Hyper-Hodge decomposition on solvmanifolds

abstract:
  We study rank $1$ flat bundles over solvmanifolds whose cohomologies are
non-trivial. By using Hodge theoretical properties for all topologically
trivial rank $1$ flat bundles, we represent the structure theorem of K\"ahler
solvmanifolds as extensions of Hasegawa's result and Benson-Gordon's result for
nilmanifolds.


title:
A generalized Bogomolov-Gieseker inequality for the smooth quadric
  threefold

abstract:
  We prove a generalized Bogomolov-Gieseker inequality as conjectured by Bayer,
Macr\`i and Toda for the smooth quadric threefold. This implies the existence
of a family of Bridgeland stability conditions.


title: Complexities of relational structures

abstract:
  The relational complexity, introduced by G. Cherlin, G. Martin, and D.
Saracino, is a measure of ultrahomogeneity of a relational structure. It
provides an information on minimal arity of additional invariant relations
needed to turn given structure into an ultrahomogeneous one. The original
motivation was group theory. This work focuses more on structures and provides
an alternative approach. Our study is motivated by related concept of lift
complexity studied by Hubicka and Nesetril.


title:
The Relativistic Green's Function Model for Quasielastic
  Neutrino-Nucleus Scattering

abstract:
  A model based on the relativistic impulse approximation for quasielastic
lepton-nucleus scattering is presented. The effects of the final-state
interactions (FSI) between the emitted nucleon and the residual nucleus are
described by the relativistic Green's function model where FSI are treated
consistently with the exclusive scattering and using the same complex optical
potential. The results of the model are compared with the results of different
descriptions of FSI and with available data for neutrino-nucleus scattering.


title: On the progenitor of the Type IIP SN 2013ej in M74

abstract:
  We use natural seeing imaging of SN 2013ej in M74 to identify a progenitor
candidate in archival {\it Hubble Space Telescope} + ACS images. We find a
source coincident with the SN in the {\it F814W}-filter, however the position
of the progenitor candidate in contemporaneous {\it F435W} and {\it
F555W}-filters is significantly offset. We conclude that the "progenitor
candidate" is in fact two physically unrelated sources; a blue source which is
likely unrelated to the SN, and a red source which we suggest exploded as SN
2013ej. Deep images with the same instrument onboard {\it HST} taken when the
supernova has faded (in approximately two years time) will allow us to
accurately characterise the unrelated neighbouring source and hence determine
the intrinsic flux of the progenitor in three filters. We suggest that the {\it
F814W} flux is dominated by the progenitor of SN 2013ej, and assuming a
bolometric correction appropriate to an M-type supergiant, we estimate that the
mass of the progenitor of SN 2013ej was between 8 -- 15.5 M$_{\odot}$.


title:
The first month of evolution of the slow rising type II-P SN 2013ej in
  M74

abstract:
  We present early photometric and spectroscopic observations of SN 2013ej, a
bright type IIP supernova in M74. SN 2013ej is one of the closest SNe ever
discovered. The available archive images and the early discovery help to
constrain the nature of its progenitor. The earliest detection of this
explosion was on 2013 July 24.14 UT and our spectroscopic monitoring began on
July 27.73 UT, continuing almost daily for two weeks with the LCOGT FLOYDS
spectrographs. Daily optical photometric monitoring was achieved with the LCOGT
1m network, and were complemented by UV data from SWIFT and near-infrared
spectra from PESSTO and IRTF. The data from our monitoring campaign show that
SN 2013ej experienced a 10-day rise before entering into a well defined plateau
phase. This unusually long rise time for a type IIP has been seen previously in
SN 2006bp and SN 2009bw. A relatively rare strong absorption blue-ward of
H{\alpha} is present since our earliest spectrum. We identify this feature as
Si ii, rather than high velocity H{\alpha} as sometimes reported in the
literature.


title: New distances to RAVE stars

abstract:
  Probability density functions are determined from new stellar parameters for
the distance moduli of stars for which the RAdial Velocity Experiment (RAVE)
has obtained spectra with S/N>=10. Single-Gaussian fits to the pdf in distance
modulus suffice for roughly half the stars, with most of the other half having
satisfactory two-Gaussian representations. As expected, early-type stars rarely
require more than one Gaussian. The expectation value of distance is larger
than the distance implied by the expectation of distance modulus; the latter is
itself larger than the distance implied by the expectation value of the
parallax. Our parallaxes of Hipparcos stars agree well with the values measured
by Hipparcos, so the expectation of parallax is the most reliable distance
indicator. The latter are improved by taking extinction into account. The
effective temperature absolute-magnitude diagram of our stars is significantly
improved when these pdfs are used to make the diagram. We use the method of
kinematic corrections devised by Schoenrich, Binney & Asplund to check for
systematic errors for general stars and confirm that the most reliable distance
indicator is the expectation of parallax. For cool dwarfs and low-gravity
giants <pi> tends to be larger than the true distance by up to 30 percent. The
most satisfactory distances are for dwarfs hotter than 5500 K. We compare our
distances to stars in 13 open clusters with cluster distances from the
literature and find excellent agreement for the dwarfs and indications that we
are over-estimating distances to giants, especially in young clusters.


title:
Neutrino-pair emission from nuclear de-excitation in core-collapse
  supernova simulations

abstract:
  We study the impact of neutrino-pair production from the de-excitation of
highly excited heavy nuclei on core-collapse supernova simulations, following
the evolution up to several 100 ms after core bounce. Our study is based on the
AGILE-Boltztran supernova code, which features general relativistic radiation
hydrodynamics and accurate three-flavor Boltzmann neutrino transport in
spherical symmetry. In our simulations the nuclear de-excitation process is
described in two different ways. At first we follow the approach proposed by
Fuller and Meyer [Astrophys. J. 376,701 (1991)], which is based on strength
functions derived in the framework of the nuclear Fermi-gas model of
non-interacting nucleons. Secondly, we parametrize the allowed and forbidden
strength distributions in accordance with measurements for selected nuclear
ground states. We determine the de-excitation strength by applying the Brink
hypothesis and detailed balance. For both approaches, we find that nuclear
de-excitation has no effect on the supernova dynamics. However, we find that
nuclear de-excitation is the leading source for the production of electron
antineutrinos as well as heavy-lepton flavor (anti)neutrinos during the
collapse phase. At sufficiently high densities, the associated neutrino spectra
are influenced by interactions with the surrounding matter, making proper
simulations of neutrino transport important for the determination of the
neutrino-energy loss rate. We find that even including nuclear de-excitations,
the energy loss during the collapse phase is overwhelmingly dominated by
electron neutrinos produced by electron captures.


title:
Constraints on the Galactic Bar from the Hercules stream as traced with
  RAVE across the Galaxy

abstract:
  Non-axisymmetries in the Galactic potential (spiral arms and bar) induce
kinematic groups such as the Hercules stream. Assuming that Hercules is caused
by the effects of the Outer Lindblad Resonance of the Galactic bar, we model
analytically its properties as a function of position in the Galaxy and its
dependence on the bar's pattern speed and orientation. Using data from the RAVE
survey we find that the azimuthal velocity of the Hercules structure decreases
as a function of Galactocentric radius, in a manner consistent with our
analytical model. This allows us to obtain new estimates of the parameters of
the Milky Way's bar. The combined likelihood function of the bar's pattern
speed and angle has its maximum for a pattern speed of $\Omega_b=(1.89 \pm
0.08) \times \Omega_0$ where $\Omega_0$ is the local circular frequency.
Assuming a Solar radius of 8.05 kpc and a local circular velocity of 238 km/s,
this corresponds to $\Omega_b=56\pm 2$ km/s/kpc. On the other hand, the bar's
orientation $\phi_b$ cannot be constrained with the available data. In fact,
the likelihood function shows that a tight correlation exists between the
pattern speed and the orientation, implying that a better description of our
best fit results is given by the linear relation $\Omega_b/\Omega_0=1.91 +
0.0044[\phi_b(\deg)-48]$, with standard deviation of 0.02. For example, for an
angle of $\phi_b=30\deg$ the pattern speed is $54.0\pm0.5$ km/s/kpc. These
results are not very sensitive to the other Galactic parameters such as the
circular velocity curve or the peculiar motion of the Sun, and are robust to
biases in distance.


title:
Diffuse interstellar band at 8620 \AA\ in RAVE: A new method for
  detecting the diffuse interstellar band in spectra of cool stars

abstract:
  Diffuse interstellar bands are usually observed in spectra of hot stars,
where interstellar lines are rarely blended with stellar ones. The need for hot
stars is a strong limitation in the number of sightlines we can observe and the
distribution of sightlines in the Galaxy, as hot stars are rare and
concentrated in the Galactic plane. We are introducing a new method, where
interstellar lines can be observed in spectra of cool stars in large
spectroscopic surveys. The method is completely automated and does not require
prior knowledge of the stellar parameters. If known, the stellar parameters
only reduce the computational time and are not involved in the extraction of
the interstellar spectrum. The main step in extracting interstellar lines is a
construction of the stellar spectrum, which is in our method done by finding
other observed spectra that lack interstellar features and are otherwise very
similar to the spectrum in question. Such spectra are then combined into a
single stellar spectrum template, which matches the stellar component in an
observed spectrum. We demonstrate the performance of this new method on a
sample of 482,430 spectra observed in RAVE survey. However, many spectra have
to be combined (48 on average) in order to achieve a S/N ratio high enough to
measure the DIB's profile, hence limiting the spatial information about the
ISM. Only one strong interstellar line is included in the RAVE spectral range,
a diffuse interstellar band at 8620 \AA. We compare its equivalent width with
extinction maps and with Bayesian reddening, calculated for individual stars,
and provide a linear relation between the equivalent width and reddening.
Separately from the introduced method, we calculate equivalent widths of the
diffuse interstellar band in spectra of hot stars with known extinction and
compare all three linear relations with each other and with relations from the
literature.


title: Chromospherically Active Stars in the RAVE Survey. I. The Catalogue

abstract:
  RAVE, the unbiased magnitude limited survey of the southern sky stars,
contained 456,676 medium-resolution spectra at the time of our analysis.
Spectra cover the CaII IRT range which is a known indicator of chromospheric
activity. Our previous work (Matijevi\v{c} et al. 2012) classified all spectra
using locally linear embedding. It identified 53,347 cases with a suggested
emission component in calcium lines. Here we use a spectral subtraction
technique to measure the properties of this emission. Synthetic templates are
replaced by the observed spectra of non-active stars to bypass the difficult
computations of non-LTE profiles of the line cores and stellar parameter
dependence. We derive both the equivalent width of the excess emission for each
calcium line on a 5\AA\ wide interval and their sum EW_IRT for ~44,000
candidate active dwarf stars with S/N>20 and with no respect to the source of
their emission flux. From these ~14,000 show a detectable chromospheric flux
with at least 2\sigma\ confidence level. Our set of active stars vastly
enlarges previously known samples. Atmospheric parameters and in some cases
radial velocities of active stars derived from automatic pipeline suffer from
systematic shifts due to their shallower calcium lines. We re-estimate the
effective temperature, metallicity and radial velocities for candidate active
stars. The overall distribution of activity levels shows a bimodal shape, with
the first peak coinciding with non-active stars and the second with the pre
main-sequence cases. The catalogue will be publicly available with the next
RAVE public data releases.


title: Segmentation of Encrypted data

abstract:
  The retrieval of data from computer hard drives that have been seized from
police busts against suspected criminals are sometimes not straight forward.
Typically the incriminating data, which may be important evidence in subsequent
trials, is encrypted and quick deleted. The cryptanalysis of what can be
recovered from such hard drives is then subject to time-consuming brute-forcing
and password guessing. To this end methods for accurate classification of what
is encrypted data and what is not is of the essence. Here a procedure for
discriminating encrypted data from non-encrypted is derived. Several methods
are suggested and their accuracy is evaluated in different ways. Two methods to
detect where encrypted data is located in a hard disk drive are detailed using
passive change-point detection. The measures of performance of such methods are
discussed and a new property for evaluation is suggested. The methods are then
evaluated and discussed according to the new performance measure as well as the
standard measures.


title: Bp stars in OrionOB1 association

abstract:
  A total of 85 CP stars of various types are identified among 814 members of
the Orion OB1 association. We selected 59 Bp stars, which account for 13.4% of
the total number of B type stars in the association. The fraction of peculiar B
type stars in the association is found to be twice higher than that of peculiar
A type stars. Magnetic field are found in 22 stars, 17 of them are objects with
anomalous helium lines. No significant differences are found between the field
strengths in the Bp type stars of the association and Bp type field stars. We
identified 17 binaries, which make up 20% of the total number of peculiar stars
studied which is the standard ratio for CP stars.


title:
Photonic architecture for scalable quantum information processing in
  NV-diamond

abstract:
  Physics and information are intimately connected, and the ultimate
information processing devices will be those that harness the principles of
quantum mechanics. Many physical systems have been identified as candidates for
quantum information processing, but none of them are immune from errors. The
challenge remains to find a path from the experiments of today to a reliable
and scalable quantum computer. Here, we develop an architecture based on a
simple module comprising an optical cavity containing a single
negatively-charged nitrogen vacancy centre in diamond. Modules are connected by
photons propagating in a fiber-optical network and collectively used to
generate a topological cluster state, a robust substrate for quantum
information processing. In principle, all processes in the architecture can be
deterministic, but current limitations lead to processes that are probabilistic
but heralded. We find that the architecture enables large-scale quantum
information processing with existing technology.


title:
Mean-convex Alexandrov embedded constant mean curvature tori in the
  3-sphere

abstract:
  We introduce the moduli space of spectral curves of constant mean curvature
(\cmc\hspace{-5pt}) cylinders of finite type in the round unit 3-sphere. The
subset of spectral curves of mean-convex Alexandrov embedded cylinders is
explicitly determined using a combination of integrable systems and geometric
analysis techniques. We prove that these cylinders are surfaces of revolution.
As a consequence all mean-convex Alexandrov embedded {\sc{cmc}} tori in the
3-sphere are surfaces of revolution.


title: Chemical gradients in the Milky Way from the RAVE data. I. Dwarf stars

abstract:
  Aim: We aim at measuring the chemical gradients of the elements Mg, Al, Si,
and Fe along the Galactic radius to provide new constraints on the chemical
evolution models of the Galaxy and Galaxy models such as the Besancon model.
  Methods: We analysed three different samples selected from three independent
datasets: a sample of 19,962 dwarf stars selected from the RAVE database, a
sample of 10,616 dwarf stars selected from the Geneva-Copenhagen Survey (GCS)
dataset, and a mock sample (equivalent to the RAVE sample) created by using the
GALAXIA code, which is based on the Besancon model. We measured the chemical
gradients as functions of the guiding radius (Rg) at different distances from
the Galactic plane reached by the stars along their orbit (Zmax).
  Results: The chemical gradients of the RAVE and GCS samples are negative and
show consistent trends, although they are not equal: at Zmax<0.4 kpc and
4.5<Rg(kpc)<9.5, the iron gradient for the RAVE sample is d[Fe/H]/dRg=-0.065
dex kpc^{-1}, whereas for the GCS sample it is d[Fe/H]/dRg=-0.043 dex kpc^{-1}
with internal errors +-0.002 and +-0.004 dex kpc^{-1}, respectively. The
gradients of the RAVE and GCS samples become flatter at larger Zmax.
Conversely, the mock sample has a positive iron gradient of
d[Fe/H]/dRg=+0.053+-0.003 dex kpc^{-1} at Zmax<0.4 kpc and remains positive at
any Zmax. These positive and unrealistic values originate from the lack of
correlation between metallicity and tangential velocity in the Besancon model.
The discrepancies between the observational samples and the mock sample can be
reduced by i) decreasing the density, ii) decreasing the vertical velocity, and
iii) increasing the metallicity of the thick disc in the Besancon model.


title: From local to global ideal-triangularizability

abstract:
  Let L be a Banach lattice with order continuous norm, and let S be a
multiplicative semigroup of ideal-triangularizable positive compact operators
on L such that, for every pair A, B in S, the atomic diagonal of the commutator
AB-BA is equal to zero. We prove that the semigroup S is
ideal-triangularizable.


title:
Magnetic properties of Gd3+ ions in the spatially distributed DNA
  molecules

abstract:
  Magnetic properties of DNA liquid-crystal dispersions are experimentally
investigated by SQUID magnetometer. The magnetic susceptibility of pure DNA and
DNA doped by La, and Gd is measured in the region 4.2-300 K. The total magnetic
moment is represented as a sum of: the paramagnetic part and negative
diamagnetic part. The number of paramagnetic Gd3+ ions is calculated in a good
agreement with the number of phosphate complexes. The temperature dependence of
magnetic susceptibility indicates the presence of interaction between Gd3+
magnetic moments, which is discussed in terms of long-range RKKY-type exchange
in one-dimensional metals.


title: Note on the thermodynamics and the speed of sound of a scalar field

abstract:
  We investigate the correspondence between a perfect fluid and a scalar field
and show a possible way of expressing thermodynamic quantities such as entropy,
particle number density, temperature and chemical potential in terms of the
scalar field phi and its kinetic term X. We prove a theorem which relates
isentropy with purely kinetic Lagrangian. As an application, we study the
evolution of the gravitational potential in cosmological perturbation theory.


title: Neuromorphic Learning towards Nano Second Precision

abstract:
  Temporal coding is one approach to representing information in spiking neural
networks. An example of its application is the location of sounds by barn owls
that requires especially precise temporal coding. Dependent upon the azimuthal
angle, the arrival times of sound signals are shifted between both ears. In
order to deter- mine these interaural time differences, the phase difference of
the signals is measured. We implemented this biologically inspired network on a
neuromorphic hardware system and demonstrate spike-timing dependent plasticity
on an analog, highly accelerated hardware substrate. Our neuromorphic
implementation enables the resolution of time differences of less than 50 ns.
On-chip Hebbian learning mechanisms select inputs from a pool of neurons which
code for the same sound frequency. Hence, noise caused by different synaptic
delays across these inputs is reduced. Furthermore, learning compensates for
variations on neuronal and synaptic parameters caused by device mismatch
intrinsic to the neuromorphic substrate.


title: The RAdial Velocity Experiment (RAVE): Fourth data release

abstract:
  We present the stellar atmospheric parameters (effective temperature, surface
gravity, overall metallicity), radial velocities, individual abundances and
distances determined for 425 561 stars, which constitute the fourth public data
release of the RAdial Velocity Experiment (RAVE). The stellar atmospheric
parameters are computed using a new pipeline, based on the algorithms of
MATISSE and DEGAS. The spectral degeneracies and the 2MASS photometric
information are now better taken into consideration, improving the parameter
determination compared to the previous RAVE data releases. The individual
abundances for six elements (magnesium, aluminum, silicon, titanium, iron and
nickel) are also given, based on a special-purpose pipeline which is also
improved compared to that available for the RAVE DR3 and Chemical DR1 data
releases. Together with photometric information and proper motions, these data
can be retrieved from the RAVE collaboration website and the Vizier database.


title: Galactic kinematics and dynamics from RAVE stars

abstract:
  We analyse the kinematics of ~400000 RAVE stars. We split the sample into hot
and cold dwarfs, red-clump and non-clump giants. The kinematics of the clump
giants are consistent with being identical with those of non-clump giants. We
fit Gaussian velocity ellipsoids to the meridional-plane components of velocity
of each star class and give formulae from which the shape and orientation of
the velocity ellipsoid can be determined at any location. The data are
consistent with the giants and the cool dwarfs sharing the same velocity
ellipsoids; sigma_z rises from 21 kms in the plane to sim 55 kms at |z|=2 kpc,
while sigma_r rises from 37 kms to 82 kms. At (R,z) the longest axis of one of
these velocity ellipsoids is inclined to the Galactic plane by an angle ~0.8
arctan(z/R). We use a novel formula to obtain precise fits to the highly
non-Gaussian distributions of v_phi components.
  We compare the observed velocity distributions with the predictions of a
dynamical model fitted to the velocities of stars that lie within ~150 pc of
the Sun and star counts towards the Galactic pole. The model accurately
reproduces the non-Gaussian nature of the v_r and v_z distributions and
provides excellent fits to the data for v_z at all locations. The model v_phi
distributions for the cool dwarfs fit the data extremely well, while those for
the hot dwarfs have displacements to low v_phi that grow with |z| from very
small values near the plane. At |z|>0.5 kpc, the theoretical v_phi
distributions for giants show a deficit of stars with large v_phi and the model
v_r distributions are too narrow. Systematically over-estimating distances by
20 per cent introduces asymmetry into the model v_r and v_z distributions near
the plane and but significantly improves the fits to the data at |z|>0.5 kpc.
The quality of the fits lends credence to the assumed, disc-dominated,
gravitational potential.


title: Accurate Computation of Survival Statistics in Genome-wide Studies

abstract:
  A key challenge in genomics is to identify genetic variants that distinguish
patients with different survival time following diagnosis or treatment. While
the log-rank test is widely used for this purpose, nearly all implementations
of the log-rank test rely on an asymptotic approximation that is not
appropriate in many genomics applications. This is because: the two populations
determined by a genetic variant may have very different sizes; and the
evaluation of many possible variants demands highly accurate computation of
very small p-values. We demonstrate this problem for cancer genomics data where
the standard log-rank test leads to many false positive associations between
somatic mutations and survival time. We develop and analyze a novel algorithm,
Exact Log-rank Test (ExaLT), that accurately computes the p-value of the
log-rank statistic under an exact distribution that is appropriate for any size
populations. We demonstrate the advantages of ExaLT on data from published
cancer genomics studies, finding significant differences from the reported
p-values. We analyze somatic mutations in six cancer types from The Cancer
Genome Atlas (TCGA), finding mutations with known association to survival as
well as several novel associations. In contrast, standard implementations of
the log-rank test report dozens-hundreds of likely false positive associations
as more significant than these known associations.


title:
Transfer Entropy reconstruction and labeling of neuronal connections
  from simulated calcium imaging

abstract:
  Neuronal dynamics are fundamentally constrained by the underlying structural
network architecture, yet much of the details of this synaptic connectivity are
still unknown even in neuronal cultures in vitro. Here we extend a previous
approach based on information theory, the Generalized Transfer Entropy, to the
reconstruction of connectivity of simulated neuronal networks of both
excitatory and inhibitory neurons. We show that, due to the model-free nature
of the developed measure, both kinds of connections can be reliably inferred if
the average firing rate between synchronous burst events exceeds a small
minimum frequency. Furthermore, we suggest, based on systematic simulations,
that even lower spontaneous inter- burst rates could be raised to meet the
requirements of our reconstruction algorithm by applying a weak spatially
homogeneous stimulation to the entire network. By combining multiple recordings
of the same in silico network before and after pharmacologically blocking
inhibitory synaptic transmission, we show then how it becomes possible to infer
with high confidence the excitatory or inhibitory nature of each individual
neuron.


title:
Noiseless amplification of weak coherent fields exploiting energy
  fluctuations of the field

abstract:
  Quantum optics dictates that amplification of a pure state by any linear
deterministic amplifier always introduces noise in the signal and results in a
mixed output state. However, it has recently been shown that noiseless
amplification becomes possible if the requirement of a deterministic operation
is relaxed. Here we propose and analyze a noiseless amplification scheme where
the energy required to amplify the signal originates from the stochastic
fluctuations in the field itself. In contrast to previous amplification setups,
our setup shows that a signal can be amplified even if no energy is added to
the signal from external sources. We investigate the relation between the
amplification and its success rate as well as the statistics of the output
states after successful and failed amplification processes. Furthermore, we
also optimize the setup to find the maximum success rates in terms of the
reflectivities of the beam splitters used in the setup and discuss the relation
of our setup with the previous setups.


title: Spherical Hamiltonian Monte Carlo for Constrained Target Distributions

abstract:
  We propose a new Markov Chain Monte Carlo (MCMC) method for constrained
target distributions. Our method first maps the $D$-dimensional constrained
domain of parameters to the unit ball ${\bf B}_0^D(1)$. Then, it augments the
resulting parameter space to the $D$-dimensional sphere, ${\bf S}^D$. The
boundary of ${\bf B}_0^D(1)$ corresponds to the equator of ${\bf S}^D$. This
change of domains enables us to implicitly handle the original constraints
because while the sampler moves freely on the sphere, it proposes states that
are within the constraints imposed on the original parameter space. To improve
the computational efficiency of our algorithm, we split the Lagrangian dynamics
into several parts such that a part of the dynamics can be handled analytically
by finding the geodesic flow on the sphere. We apply our method to several
examples including truncated Gaussian, Bayesian Lasso, Bayesian bridge
regression, and a copula model for identifying synchrony among multiple
neurons. Our results show that the proposed method can provide a natural and
efficient framework for handling several types of constraints on target
distributions.


title: Simple free-surface detection in two and three-dimensional SPH solver

abstract:
  A simple free-surface particle detection method for two and three-dimensional
SPH simulation has been implemented. The method uses sphere representation for
the SPH particle. The fluid domain is covered by overlapping spheres. A sphere
whose surface is not fully covered considered as boundary. To test particle
boundary status, we used a sum of normalized relative position vectors from
neighbouring particles to the test particle. By checking the existence of un-
covered sphere surface by this vector sum, boundary status of the test particle
can be determined. This boundary detection method can be easily embedded in the
SPH solver algorithm.


title: Models and algorithms for skip-free Markov decision processes on trees

abstract:
  We introduce a class of models for multidimensional control problems which we
call skip-free Markov decision processes on trees. We describe and analyse an
algorithm applicable to Markov decision processes of this type that are
skip-free in the negative direction. Starting with the finite average cost
case, we show that the algorithm combines the advantages of both value
iteration and policy iteration -- it is guaranteed to converge to an optimal
policy and optimal value function after a finite number of iterations but the
computational effort required for each iteration step is comparable with that
for value iteration. We show that the algorithm can also be used to solve
discounted cost models and continuous time models, and that a suitably modified
algorithm can be used to solve communicating models.


title:
Continuous and discontinuous transitions in generalized p-spin glass
  models

abstract:
  We investigate the generalized p-spin models that contain arbitrary diagonal
operators U with no reflection symmetry. We derive general equations that give
an opportunity to uncover the behavior of the system near the glass transition
at different (continuous) p. The quadrupole glass with J=1 is considered as an
illustrating example. It is shown that the crossover from continuous to
discontinuous glass transition to one-step replica breaking solution takes
place at p=3.3 for this model. For p <2+\Delta p, where \Delta p= 0.5 is a
finite value, stable 1RSB-solution disappears. This behaviour is strongly
different from that of the p-spin Ising glass model.


title: The RAVE survey: the Galactic escape speed and the mass of the Milky Way

abstract:
  We construct new estimates on the Galactic escape speed at various
Galactocentric radii using the latest data release of the Radial Velocity
Experiment (RAVE DR4). Compared to previous studies we have a database larger
by a factor of 10 as well as reliable distance estimates for almost all stars.
Our analysis is based on the statistical analysis of a rigorously selected
sample of 90 high-velocity halo stars from RAVE and a previously published data
set. We calibrate and extensively test our method using a suite of cosmological
simulations of the formation of Milky Way-sized galaxies. Our best estimate of
the local Galactic escape speed, which we define as the minimum speed required
to reach three virial radii $R_{340}$, is $533^{+54}_{-41}$ km/s (90%
confidence) with an additional 5% systematic uncertainty, where $R_{340}$ is
the Galactocentric radius encompassing a mean over-density of 340 times the
critical density for closure in the Universe. From the escape speed we further
derive estimates of the mass of the Galaxy using a simple mass model with two
options for the mass profile of the dark matter halo: an unaltered and an
adiabatically contracted Navarro, Frenk & White (NFW) sphere. If we fix the
local circular velocity the latter profile yields a significantly higher mass
than the un-contracted halo, but if we instead use the statistics on halo
concentration parameters in large cosmological simulations as a constraint we
find very similar masses for both models. Our best estimate for $M_{340}$, the
mass interior to $R_{340}$ (dark matter and baryons), is $1.3^{+0.4}_{-0.3}
\times 10^{12}$ M$_\odot$ (corresponding to $M_{200} = 1.6^{+0.5}_{-0.4} \times
10^{12}$ M$_\odot$). This estimate is in good agreement with recently published
independent mass estimates based on the kinematics of more distant halo stars
and the satellite galaxy Leo I.


title:
Projectile fragment emission in fragmentation of $^{56}$Fe on C, Al,and
  CH$_{2}$ targets at 471 A MeV

abstract:
  The emission angle and the transverse momentum distributions of projectile
fragments produced in fragmentation of $^{56}$Fe on CH$_{2}$, C, and Al targets
at 471 A MeV are measured. It is found that for the same target the average
value and width of angular distribution decrease with increase of the
projectile fragment charge, and for the same projectile fragment the average
value of the distribution increases and the width of the distribution decreases
with increasing the target charge number. The transverse momentum distribution
of projectile fragment can be explained by a single Gaussian distribution and
the averaged transverse momentum per nucleon decreases with the increase of the
charge of projectile fragment. The cumulated squared transverse momentum
distribution of projectile fragment can be well explained by a single Rayleigh
distribution. The temperature parameter of emission source of projectile
fragment, calculated from the cumulated squared transverse momentum
distribution, decreases with the increase of the size of projectile fragment.


title:
Energy spectra of KASCADE-Grande based on shower size measurements and
  different hadronic interaction models

abstract:
  KASCADE-Grande is dedicated for investigations of cosmic-ray air showers in
the primary energy range from 10 PeV to 1 EeV. The multi-detector system allows
us to reconstruct charged particles, electron and muon numbers for individual
air showers with high accuracies. Based on the shower size ($N_{ch}$) spectra
of the charged particle component, the all-particle energy spectrum of cosmic
rays is reconstructed, where attenuation effects in the atmosphere are
corrected by applying the constant intensity cut method. The energy calibration
is performed by using CORSIKA simulations with high-energy interaction models
QGSJET-II-2, QGSJET-II-4, EPOS 1.99 and SIBYLL 2.1, where FLUKA has been used
as low-energy interaction model for all cases. In the different hadronic
models, different abundances for shower particles are predicted. Such model
differences in the observables will be compared and discussed in this
contribution. Furthermore, by using data with increasing statistics, the
updated energy spectra by means of different interaction models will be
presented.


title: An anisotropic distribution of spin vectors in asteroid families

abstract:
  Current amount of ~500 asteroid models derived from the disk-integrated
photometry by the lightcurve inversion method allows us to study not only the
spin-vector properties of the whole population of MBAs, but also of several
individual collisional families. We create a data set of 152 asteroids that
were identified by the HCM method as members of ten collisional families, among
them are 31 newly derived unique models and 24 new models with well-constrained
pole-ecliptic latitudes of the spin axes. The remaining models are adopted from
the DAMIT database or the literature. We revise the preliminary family
membership identification by the HCM method according to several additional
criteria - taxonomic type, color, albedo, maximum Yarkovsky semi-major axis
drift and the consistency with the size-frequency distribution of each family,
and consequently we remove interlopers. We then present the spin-vector
distributions for eight asteroidal families. We use a combined orbital- and
spin-evolution model to explain the observed spin-vector properties of objects
among collisional families. In general, we observe for studied families similar
trends in the (a_p, \beta) space: (i) larger asteroids are situated in the
proximity of the center of the family; (ii) asteroids with \beta>0{\deg} are
usually found to the right from the family center; (iii) on the other hand,
asteroids with \beta<0{\deg} to the left from the center; (iv) majority of
asteroids have large pole-ecliptic latitudes (|\beta|\gtrsim 30{\deg}); and
finally (v) some families have a statistically significant excess of asteroids
with \beta>0{\deg} or \beta<0{\deg}. Our numerical simulation of the long-term
evolution of a collisional family is capable of reproducing well the observed
spin-vector properties. Using this simulation, we also independently constrain
the age of families Flora (1.0\pm0.5 Gyr) and Koronis (2.5-4 Gyr).


title:
Preliminary Analysis of ULPC Light Curves Using Fourier Decomposition
  Technique

abstract:
  Recent work on Ultra Long Period Cepheids (ULPCs) has suggested their
usefulness as a distance indicator, but has not commented on their relationship
as compared with other types of variable stars. In this work, we use Fourier
analysis to quantify the structure of ULPC light curves and compare them to
Classical Cepheids and Mira variables. Our preliminary results suggest that the
low order Fourier parameters of ULPCs show a continuous trend defined by
Classical Cepheids after the resonance around 10 days. However their Fourier
parameters also overlapped with those from Miras, which make the classification
of long period variable stars difficult based on the light curves information
alone.


title: Extremal loop weight modules for $U_q(\hat{sl}_\infty)$

abstract:
  We construct by fusion product new irreducible representations of the quantum
affinization $U_q(\hat{sl}_\infty)$. The action is defined via the Drinfeld
coproduct and is related to the crystal structure of semi-standard tableaux of
type $A_\infty$. We call these representations extremal loop weight modules.
The main motivations are applications to quantum toroidal algebras
$U_q(sl_{n+1}^{tor})$: we prove the conjectural link between
$U_q(\hat{sl}_\infty)$ and $U_q(sl_{n+1}^{tor})$ stated in [14] for this family
of representations. We recover in this way the extremal loop weight modules
obtained in [23].


title:
Existence and asymptotics for solutions of a non-local Q-curvature
  equation in dimension three

abstract:
  We study conformal metrics on $R^3$, i.e., metrics of the form
$g_u=e^{2u}|dx|^2$, which have constant $Q$-curvature and finite volume. This
is equivalent to studying the non-local equation $$ (-\Delta)^\frac32 u = 2
e^{3u}$$ in $R^3$ $$V:=\int_{\mathbb{R}^3}e^{3u}dx<\infty,$$ where $V$ is the
volume of $g_u$. Adapting a technique of A. Chang and W-X. Chen to the
non-local framework, we show the existence of a large class of such metrics,
particularly for $V\le 2\pi^2=|S^3|$. Inspired by previous works of C-S. Lin
and L. Martinazzi, who treated the analogue cases in even dimensions, we
classify such metrics based on their behavior at infinity.


title: Entanglement in fermionic Fock space

abstract:
  We propose a generalization of the usual SLOCC and LU classification of
entangled pure state fermionic systems based on the Spin group. Our
generalization uses the fact that there is a representation of this group
acting on the fermionic Fock space which when restricted to fixed particle
number subspaces recovers naturally the usual SLOCC transformations. The new
ingredient is the occurrence of Bogoliubov transformations of the whole Fock
space changing the particle number. The classification scheme built on the Spin
group prohibits naturally entanglement between states containing even and odd
number of fermions. In our scheme the problem of classification of entanglement
types boils down to the classification of spinors where totally separable
states are represented by so called pure spinors. We construct the basic
invariants of the Spin group and show how some of the known SLOCC invariants
are just their special cases. As an example we present the classification of
fermionic systems with a Fock space based on six single particle states. An
intriguing duality between two different possibilities for embedding
three-qubit systems inside the fermionic ones is revealed. This duality is
elucidated via an interesting connection to configurations of wrapped membranes
reinterpreted as qubits.


title:
Discovery of New Companions to High Proper Motion Stars from the VVV
  Survey

abstract:
  [abridged] The severe crowding in the direction of the inner Milky Way
suggests that the census of stars within a few tens of parsecs in that
direction may not be complete.
  We search for new nearby objects companions of known high proper motion (HPM)
stars located towards the densest regions of the Southern Milky Way where the
background contamination presented a major problem to previous works.
  The common proper motion (PM) method was used--we inspected the area around
167 known HPM (>=200 mas/yr) stars: 67 in the disk and 100 in the bulge.
Multi-epoch images were provided by 2MASS and the VISTA Variables in Via Lactea
(VVV). The VVV is a new on-going ZYJHKs plus multi-epoch Ks survey of ~562
deg^2 of Milky Way's bulge and inner Southern disk.
  Seven new co-moving companions were discovered around known HPM stars; six
known co-moving pairs were recovered; a pair of stars that was thought to be
co-moving was found to have different proper motions; published HPMs of eight
stars were not confirmed; last but not least, spectral types ranging from G8V
to M5V were derived from new infrared spectroscopy for seventeen stars, members
of the co-moving pairs.
  The seven newly discovered stars constitute ~4% of the nearby HPM star list
but this is not a firm limit on the HPM star incompleteness because our
starting point--the HPM list assembled from the literature--is incomplete
itself, missing many nearby HPM M and L type objects, and it is contaminated
with non-HPM stars. We have demonstrated, that the superior sub-arcsec spatial
resolution, with respect to previous surveys, allows the VVV to examine further
the binary nature nature of known HPM stars. The >=5 yr span of VVV will
provide sufficient baseline for finding new HPM stars from VVV data alone.


title:
Hypermagnetic helicity evolution in early universe: leptogenesis and
  hypermagnetic diffusion

abstract:
  We study hypermagnetic helicity and lepton asymmetry evolution in plasma of
the early Universe before the electroweak phase transition (EWPT) accounting
for chirality flip processes via inverse Higgs decays and sphaleron transitions
which violate the left lepton number and wash out the baryon asymmetry of the
Universe (BAU). In the scenario where the right electron asymmetry supports the
BAU alone through the conservation law $B/3 - L_{eR}=const$ at temperatures
$T>T_{RL}\simeq 10 TeV$ the following universe cooling leads to the production
of a non-zero left lepton (electrons and neutrinos) asymmetry. This is due to
the Higgs decays becoming more faster when entering the equilibrium at
$T=T_{RL}$ with the universe expansion, $\Gamma_{RL}\sim T> H\sim T^2$,
resulting in the parallel evolution of both the right and the left electron
asymmetries at $T<T_{RL}$ through the corresponding Abelian anomalies in SM in
the presence of a seed hypermagnetic field. The hypermagnetic helicity
evolution proceeds in a self-consistent way with the lepton asymmetry growth.
The role of sphaleron transitions decreasing the left lepton number turns out
to be negligible in given scenario. The hypermagnetic helicity can be a supply
for the magnetic one in Higgs phase assuming a strong seed hypermagnetic field
in symmetric phase.


title: Y(4260): hadronic molecule versus hadro-charmonium interpretation

abstract:
  In this paper we confront both the hadronic molecule and the hadro-charmonium
interpretations of the $\y$ with the experimental data currently available. We
conclude that the data support the $\y$ being dominantly a $D_1\bar D+c.c.$
hadronic molecule while they challenge the hadro-charmonium interpretation.
However, additional data is necessary to allow for stronger conclusions.


title: K\"ahler non-collapsing, eigenvalues and the Calabi flow

abstract:
  We first proved a compactness theorem of the K\"ahler metrics, which confirms
a prediction of Chen. Then we prove several eigenvalue estimates along the
Calabi flow. Combining the compactness theorem and these eigenvalue estimates,
we generalize the method developed by Chen-Li-Wang to prove the small energy
theorems of the Calabi flow.


title:
An almost symmetric Strang splitting scheme for nonlinear evolution
  equations

abstract:
  In this paper we consider splitting methods for the time integration of
parabolic and certain classes of hyperbolic partial differential equations,
where one partial flow can not be computed exactly. Instead, we use a numerical
approximation based on the linearization of the vector field. This is of
interest in applications as it allows us to apply splitting methods to a wider
class of problems from the sciences.
  However, in the situation described the classic Strang splitting scheme,
while still a method of second order, is not longer symmetric. This, in turn,
implies that the construction of higher order methods by composition is limited
to order three only. To remedy this situation, based on previous work in the
context of ordinary differential equations, we construct a class of Strang
splitting schemes that are symmetric up to a desired order.
  We show rigorously that, under suitable assumptions on the nonlinearity,
these methods are of second order and can then be used to construct higher
order methods by composition. In addition, we illustrate the theoretical
results by conducting numerical experiments for the Brusselator system and the
KdV equation.


title: Sparsity Based Poisson Denoising with Dictionary Learning

abstract:
  The problem of Poisson denoising appears in various imaging applications,
such as low-light photography, medical imaging and microscopy. In cases of high
SNR, several transformations exist so as to convert the Poisson noise into an
additive i.i.d. Gaussian noise, for which many effective algorithms are
available. However, in a low SNR regime, these transformations are
significantly less accurate, and a strategy that relies directly on the true
noise statistics is required. A recent work by Salmon et al. took this route,
proposing a patch-based exponential image representation model based on GMM
(Gaussian mixture model), leading to state-of-the-art results. In this paper,
we propose to harness sparse-representation modeling to the image patches,
adopting the same exponential idea. Our scheme uses a greedy pursuit with
boot-strapping based stopping condition and dictionary learning within the
denoising process. The reconstruction performance of the proposed scheme is
competitive with leading methods in high SNR, and achieving state-of-the-art
results in cases of low SNR.


title:
Two rings but no fellowship: LoTr 1 and its relation to planetary
  nebulae possessing barium central stars

abstract:
  LoTr 1 is a planetary nebula thought to contain an intermediate-period binary
central star system (that is, a system with an orbital period, P, between 100
and, say, 1500 days). The system shows the signature of a K-type, rapidly
rotating giant, and most likely constitutes an accretion-induced post-mass
transfer system similar to other PNe such as LoTr 5, WeBo 1 and A70. Such
systems represent rare opportunities to further the investigation into the
formation of barium stars and intermediate period post-AGB systems -- a
formation process still far from being understood. Here, we present the first
detailed analyses of both the central star system and the surrounding nebula of
LoTr 1 using a combination of spectra obtained with VLT-FORS2, AAT-UCLES and
NTT-EMMI, as well as SuperWASP photometry. We confirm the binary nature of the
central star of LoTr 1 that consists of a K1 III giant and a hot white dwarf.
The cool giant does not present any sign of s-process enhancement but is shown
to have a rotation period of 6.4 days, which is a possible sign of mass
accretion. LoTr 1 also presents broad double-peaked H-alpha emission lines,
whose origin is still unclear. The nebula of LoTr 1 consists in two slightly
elongated shells, with ages of 17,000 and 35,000 years, respectively, and with
different orientations. As such, LoTr 1 present a very different nebular
morphology than A70 and WeBo 1, which may be an indication of difference in the
mass transfer episodes


title: Pitch angle variations in spiral galaxies

abstract:
  We present a detailed photometric study and measurements of spiral arm pitch
angles for a sample of 50 non-barred or weakly barred grand-design spiral
galaxies selected from Sloan Digital Sky Survey. In order to find pitch angles,
we used a new method based on the window Fourier analysis of their images. This
method allows us not only to infer the average pitch angle, but to obtain its
value as a function of galactocentric radius as well. Our main results are as
follows:
  (1) Spiral arms of most galaxies cannot be described by a single value of the
pitch angle. About 2/3 of galaxies demonstrate pitch angle variations exceeding
20%. In most galaxies in the sample their pitch angle decreases by increasing
the distance from the centre.
  (2) Pitch angle variations correlate with the properties of galaxies - with
the shape of the surface brightness distribution (envelope-type or truncated
disc), and with the sign of stellar disc colour gradient.
  (3) More luminous and bright bulges produce more tightly wound spiral arms,
that is in agreement with current models for spiral arms formation.


title: Uniform bounds for expressions involving modified Bessel functions

abstract:
  In this paper, we obtain uniform bounds for a number of expressions that
involve derivatives and integrals of modified Bessel functions. These uniform
bounds are motivated by the need to bound such expressions in the study of
variance-gamma and product normal approximations via Stein's method.


title: The same-sign top probe for baryon number violation at the LHC

abstract:
  Despite strong experimental evidences for their conservation at low energies,
the baryon $B$ and lepton $L$ numbers are not expected to be absolute
symmetries. Already violated in the Standard Model (SM) by non-perturbative
effects (tiny at low temperatures and energies) and not justified by any
fundamental principle, $B$ and $L$ appear naturally violated in beyond the
Standard Model (BSM) scenarios, e.g. in supersymmetry (SUSY). The fact that any
violation remained unobserved at low energies can nonetheless be explained,
without pushing the associated characteristic sale beyond the TeV, by using SM
flavour symmetries implemented BSM thanks to the Minimal Flavour Violation
(MFV) prescription. Violation effects could therefore be observable at the LHC.
Same-sign (anti-)tops, sometimes leading to a distinctive predominance of
negatively charged lepton pairs over positively charged ones, is a clean
signature that is for instance generically present in R-parity violating
supersymmetry.


title: The SU(3) Beta Function from Numerical Stochastic Perturbation Theory

abstract:
  The SU(3) beta function is computed from Wilson loops to 20th order numerical
stochastic perturbation theory. An attempt is made to include massless
fermions, whose contribution is known analytically to 4th order. The question
whether the theory admits an infrared stable fixed point is addressed.


title:
Bimodal switching field distributions in all-perpendicular spin-valve
  nanopillars

abstract:
  Switching field measurements of the free layer element of 75 nm diameter
spin-valve nanopillars reveal a bimodal distribution of switching fields at low
temperatures (below 100 K). This result is inconsistent with a model of thermal
activation over a single perpendicular anisotropy barrier. The correlation
between antiparallel to parallel and parallel to antiparallel switching fields
increases to nearly 50% at low temperatures. This reflects random fluctuation
of the shift of the free layer hysteresis loop between two different
magnitudes, which may originate from changes in the dipole field from the
polarizing layer. The magnitude of the loop shift changes by 25% and is
correlated to transitions of the spin-valve into an antiparallel configuration.


title: Relative motion in spacetime

abstract:
  In Minkowski spacetime, we consider an isolated system made of two pointlike
bodies interacting at a distance, in the nonradiative approximation. Our
framework is the covariant and a priori Hamiltonian formalism of "predictive
relativistic mechanics", founded on the equal-time condition. The issue of an
equivalent one-body description is discussed. We distinguish two different
concepts: on the one hand an almost purely kinematic relative particle, on the
other hand an effective particle which involves an explicit dynamical
formulation; several versions of the latter are possible. Relative and
effective particles have the same orbit, but may differ by their schedules.


title:
CoRoT target HD 51844: a delta Scuti star in a binary system with
  periastron brightening

abstract:
  The star HD 51844 was observed in CoRoT LRa02 as a Seismo target which turned
out to be an SB2 system. The 117 days long light curve revealed delta Scuti
pulsation in the range of 6 to 15 d^{-1} where four frequencies have amplitudes
larger than 1.4 mmag and a rich frequency spectrum with amplitudes lower than
0.6 mmag. Additionally, the light curve exhibits a brightening event recurring
every 33.5 days with a maximum of 3 mmag and a duration of about 5 days. Thus,
this star can be considered as a heartbeat candidate. The radial velocities
from spectroscopy confirmed an eccentric binary system with nearly identical
masses and physical parameters. The brightening event of the light curve
coincides with the maximum radial velocity separation showing that the
brightening is in fact caused by tidal distortion and/or reflected light. One
component displays large line profile variations, while the other does not show
significant variation. The frequency analysis revealed a quintuplet structure
of the four highest-amplitude frequencies, which is due to the orbital motion
of the pulsating star.


title:
Non-conventional ergodic averages for several commuting actions of an
  amenable group

abstract:
  Let $(X,\mu)$ be a probability space, $G$ a countable amenable group and
$(F_n)_n$ a left F\o lner sequence in $G$. This paper analyzes the
non-conventional ergodic averages \[\frac{1}{|F_n|}\sum_{g \in
F_n}\prod_{i=1}^d (f_i\circ T_1^g\cdots T_i^g)\] associated to a commuting
tuple of $\mu$-preserving actions $T_1$, ..., $T_d:G\curvearrowright X$ and
$f_1$, ..., $f_d \in L^\infty(\mu)$. We prove that these averages always
converge in $\|\cdot\|_2$, and that they witness a multiple recurrence
phenomenon when $f_1 = \ldots = f_d = 1_A$ for a non-negligible set $A\subseteq
X$. This proves a conjecture of Bergelson, McCutcheon and Zhang. The proof
relies on an adaptation from earlier works of the machinery of sated
extensions.


title:
Extending spin coherence times of diamond qubits by high temperature
  annealing

abstract:
  Spins of negatively charged nitrogen-vacancy (NV$^-$) defects in diamond are
among the most promising candidates for solid-state qubits. The fabrication of
quantum devices containing these spin-carrying defects requires
position-controlled introduction of NV$^-$ defects having excellent properties
such as spectral stability, long spin coherence time, and stable negative
charge state. Nitrogen ion implantation and annealing enable the positioning of
NV$^-$ spin qubits with high precision, but to date, the coherence times of
qubits produced this way are short, presumably because of the presence of
residual radiation damage. In the present work, we demonstrate that a high
temperature annealing at 1000$^\circ$C allows 2 millisecond coherence times to
be achieved at room temperature. These results were obtained for
implantation-produced NV$^-$ defects in a high-purity, 99.99% $^{12}$C enriched
single crystal chemical vapor deposited diamond. We discuss these remarkably
long coherence times in the context of the thermal behavior of residual defect
spins. [Published in Physical Review B {\bf{88}}, 075206 (2013)]


title:
Design and Testing of Kinetic Inductance Detectors Made of Titanium
  Nitride

abstract:
  To use highly resistive material for Kinetic Inductance Detectors (KID), new
designs have to be done, in part due to the impedance match needed between the
KID chip and the whole 50 ohms readout circuit. Chips from two new hybrid
designs, with an aluminum throughline coupled to titanium nitride
microresonators, have been measured and compared to a TiN only chip. In the
hybrid chips, parasitic temperature dependent box resonances are absent. The
dark KID properties have been measured in a large set of resonators. A
surprisingly long lifetime, up to 5.6 ms is observed in a few KIDs. For the
other more reproducible devices, the mean electrical Noise Equivalent Power is
5.4 10-19 W.Hz1/2.


title: Isorotating Baby Skyrmions

abstract:
  We discuss how internal rotation with fixed angular frequency can affect the
solitons in the baby Skyrme model in which the global O(3) symmetry is broken
to the SO(2). Two particular choices of the potential term are considered, the
"old" potential and the "new" double vacuum potential, We do not impose any
assumptions about the symmetry on the fields. Our results confirm existence of
two types of instabilities determined by the relation between the mass
parameter of the potential and the angular frequency.


title: Layer-dependent Electrocatalysis of MoS2 for Hydrogen Evolution

abstract:
  The quantitative correlation of the catalytic activity with microscopic
structure of heterogeneous catalysts is a major challenge for the field of
catalysis science. It requests synergistic capabilities to tailor the structure
with atomic scale precision and to control the catalytic reaction to proceed
through well-defined pathways. Here we leverage on the controlled growth of
MoS2 atomically thin films to demonstrate that the catalytic activity of MoS2
for the hydrogen evolution reaction decreases by a factor of ~4.47 for the
addition of every one more layer. Similar layer dependence is also found in
edge-riched MoS2 pyramid platelets. This layer-dependent electrocatalysis can
be correlated to the hopping of electrons in the vertical direction of MoS2
layers over an interlayer potential barrier, which is found to be 0.119V and
consistent with theoretical calculations. Our results point out that increasing
the hopping efficiency of electrons in the vertical direction is a key for the
development of high-efficiency two-dimensional material catalysts.


title: Congruences Among Power Series Coefficients of Modular Forms

abstract:
  Many authors have investigated the congruence relations amongst the
coefficients of power series expansions of modular forms $f$ in modular
functions $t$. In a recent paper, R. Osburn and B. Sahu examine several power
series expansions and prove that the coefficients exhibit congruence relations
similar to the congruences satisfied by the Ap\'ery numbers associated with the
irrationality of $\zeta(3)$. We show that many of the examples of Osburn and
Sahu are members of infinite families.


title: Cryogenic Calibration Setup for Broadband Complex Impedance Measurements

abstract:
  Reflection measurements give access to the complex impedance of a material on
a wide frequency range. This is of interest to study the dynamical properties
of various materials, for instance disordered superconductors. However
reflection measurements made at cryogenic temperature suffer from the
difficulty to reliably subtract the circuit contribution. Here we report on the
design and first tests of a setup able to precisely calibrate in situ the
sample reflection, at 4.2 K and up to 2 GHz, by switching and measuring, during
the same cool down, the sample and three calibration standards.


title: Generators with a closure relation

abstract:
  Assume that a block operator of the form
$\left(\begin{smallmatrix}A_{1}\\A_{2}\quad 0\end{smallmatrix}\right)$, acting
on the Banach space $X_{1}\times X_{2}$, generates a contraction
$C_{0}$-semigroup. We show that the operator $A_{S}$ defined by
$A_{S}x=A_{1}\left(\begin{smallmatrix}x\\SA_{2}x\end{smallmatrix}\right)$ with
the natural domain generates a contraction semigroup on $X_{1}$. Here, $S$ is a
boundedly invertible operator for which $\epsilon\ide-S^{-1}$ is dissipative
for some $\epsilon>0$. With this result the existence and uniqueness of
solutions of the heat equation can be derived from the wave equation.


title: Terrain visibility with multiple viewpoints

abstract:
  We study the problem of visibility in polyhedral terrains in the presence of
multiple viewpoints. We consider a triangulated terrain with $m>1$ viewpoints
(or guards) located on the terrain surface. A point on the terrain is
considered \emph{visible} if it has an unobstructed line of sight to at least
one viewpoint. We study several natural and fundamental visibility structures:
(1) the visibility map, which is a partition of the terrain into visible and
invisible regions; (2) the \emph{colored} visibility map, which is a partition
of the terrain into regions whose points have exactly the same visible
viewpoints; and (3) the Voronoi visibility map, which is a partition of the
terrain into regions whose points have the same closest visible viewpoint. We
study the complexity of each structure for both 1.5D and 2.5D terrains, and
provide efficient algorithms to construct them. Our algorithm for the
visibility map in 2.5D terrains improves on the only existing algorithm in this
setting. To the best of our knowledge, the other structures have not been
studied before.


title: Exotic dibaryons with a heavy antiquark

abstract:
  We discuss the possible existence of exotic dibaryons with a heavy antiquark,
being realized three-body systems, Dbar^(*)NN and B^(*)NN. These are genuinely
exotic states with no quark-antiquark annihilation. We consider the heavy quark
spin and chiral symmetries, and introduce the one pion exchange potential
between a Dbar^(*) (B^(*)) meson and a nucleon N. As for the NN interaction, we
employ the Argonne v^\prime_8 potential. By solving the coupled-channel
equations for PNN and P^* NN (P^(*)=Dbar^(*) and B^(*)), we find bound states
for (I,J^P)=(1/2,0^-) as well as resonant states for (I,J^P)=(1/2,1^-) both in
Dbar^(*)NN and B^(*)NN systems. We also discuss the heavy quark limit, and find
that the spin degeneracy is realized in the bound states with (I,J^P)=(1/2,0^-)
and (1/2,1^-).


title:
A RAVE Investigation on Galactic open Clusters I. Radial velocities and
  metallicities

abstract:
  Context. Galactic open clusters (OCs) mainly belong to the young stellar
population in the Milky Way disk, but are there groups and complexes of OCs
that possibly define an additional level in hierarchical star formation?
Current compilations are too incomplete to address this question, especially
regarding radial velocities (RVs) and metallicities ($[M/H]$). Aims. Here we
provide and discuss newly obtained RV and $[M/H]$ data, which will enable us to
reinvestigate potential groupings of open clusters and associations. Methods.We
extracted additional RVs and $[M/H]$ from the RAdial Velocity Experiment (RAVE)
via a cross-match with the Catalogue of Stars in Open Cluster Areas (CSOCA).
For the identified OCs in RAVE we derived RV and $[M/H]$ from a cleaned working
sample and compared the results with previous findings. Results. Although our
RAVE sample does not show the same accuracy as the entire survey, we were able
to derive reliable RV for 110 Galactic open clusters. For 37 OCs we publish RV
for the first time. Moreover, we determined $[M/H]$ for 81 open clusters,
extending the number of OCs with $[M/H]$ by 69.


title:
Sedimentation of a two-dimensional colloidal mixture exhibiting
  liquid-liquid and gas-liquid phase separation: a dynamical density functional
  theory study

abstract:
  We present dynamical density functional theory results for the time evolution
of the density distribution of a sedimenting model two-dimensional binary
mixture of colloids. The interplay between the bulk phase behaviour of the
mixture, its interfacial properties at the confining walls, and the
gravitational field gives rise to a rich variety of equilibrium and
non-equilibrium morphologies. In the fluid state, the system exhibits both
liquid-liquid and gas-liquid phase separation. As the system sediments, the
phase separation significantly affects the dynamics and we explore situations
where the final state is a coexistence of up to three different phases. Solving
the dynamical equations in two-dimensions, we find that in certain situations
the final density profiles of the two species have a symmetry that is different
from that of the external potentials, which is perhaps surprising, given the
statistical mechanics origin of the theory. The paper concludes with a
discussion on this.


title:
Unboundedness of fiber invariants of canonically fibred varieties of
  general type

abstract:
  We answer an open question concerning the boundedness of canonical fiber
spaces in high dimensions and prove the following: for any set of integers
$n\geq 3$, $0<d<n$ and $N>0$, there exists a nonsingular projective $n$-fold
$X$ of general type so that $X$ is canonically fibred by $d$-dimensional
varieties $F$ with $p_g(F)\geq N$. This disproves the desired boundedness
parallel to Beauville's boundedness theorem in the surface case.


title: The Beta-MANOVA Ensemble with General Covariance

abstract:
  We find the joint generalized singular value distribution and largest
generalized singular value distributions of the $\beta$-MANOVA ensemble with
positive diagonal covariance, which is general. This has been done for the
continuous $\beta > 0$ case for identity covariance (in eigenvalue form), and
by setting the covariance to $I$ in our model we get another version. For the
diagonal covariance case, it has only been done for $\beta = 1,2,4$ cases
(real, complex, and quaternion matrix entries). This is in a way the first
second-order $\beta$-ensemble, since the sampler for the generalized singular
values of the $\beta$-MANOVA with diagonal covariance calls the sampler for the
eigenvalues of the $\beta$-Wishart with diagonal covariance of Forrester and
Dubbs-Edelman-Koev-Venkataramana. We use a conjecture of MacDonald proven by
Baker and Forrester concerning an integral of a hypergeometric function and a
theorem of Kaneko concerning an integral of Jack polynomials to derive our
generalized singular value distributions. In addition we use many identities
from Forrester's {\it Log-Gases and Random Matrices}. We supply numerical
evidence that our theorems are correct.


title:
On the Riesz decomposition property and the interpolation property of
  stopping times

abstract:
  It is known that random variables have the Riesz decomposition property and
the interpolation property. These properties are not only interesting in their
own rights; they have been applied to quantitative finance and actuarial
mathematics. One would naturally ask whether the same holds for stopping times.
We give an affirmative answer in this paper. We also point out that optional
times possess these two properties too.


title: Correlations in nuclear energy recurrence relations

abstract:
  The excitation energies of states belonging to the ground state bands of
heavy even-even nuclei are analysed using recurrence relations. Excellent
agreement with experimental data at the 10 keV level is obtained by taking into
account strong correlations which emerge in the analysis. This implies that the
excitation energies can be written as a polynomial of maximum degree four in
the angular momentum.


title:
A SINFONI Integral Field Spectroscopy Survey for Galaxy Counterparts to
  Damped Lyman-alpha Systems - IV. Masses and Gas Flows

abstract:
  The circumgalactic medium (CGM) of typical galaxies is crucial to our
understanding of the cycling of gas into, through and out of galaxies. One way
to probe the CGM is to study gas around galaxies detected via the absorption
lines they produce in the spectra of background quasars. Here, we present
medium resolution and new ~0.4-arcsec resolution (~3 kpc at z~1) 3D
observations with VLT/SINFONI of galaxies responsible for high-N(HI) quasar
absorbers. These data allow to determine in details the kinematics of the
objects: the four z~1 objects are found to be rotation-supported as expected
from inclined discs, while the fifth z~2 system is dispersion-dominated. Two of
the systems show sign of interactions and merging. In addition, we use several
indicators (star formation per unit area, a comparison of emission and
absorption kinematics, arguments based on the inclination and the orientation
of the absorber to the quasar line-of-sight and the distribution of metals) to
determine the direction of the gas flows in and out of these galaxies. In some
cases, our observations are consistent with the gas seen in absorption being
due to material co-rotating with their halos. In the case of absorbing-galaxies
towards Q1009-0026 and Q2222-0946, these indicators point toward the presence
of an outflow traced in absorption.


title:
Observations on the flow structures and transport in a warm-core ring in
  the Gulf of Mexico

abstract:
  This study presents several new observations from the study of a warm-core
ring (WCR) in the Gulf of Mexico based on the ECCO2 global ocean simulation.
Using Lagrangian coherent structures (LCS) techniques to investigate this flow
reveals a pattern of transversely intersecting LCS in the mixed layer of the
WCR which experiences consistent stretching behavior over a large region of
space and time. A detailed analysis of this flow region leads to an analytical
model velocity field which captures the essential elements that generate the
transversely intersecting LCS. The model parameters are determined from the WCR
and the resulting LCS show excellent agreement with those observed in the WCR.
The three-dimensional transport behavior which creates these structures relies
on the small radial outflow which is present in the mixed layer and is not seen
below the pycnocline, leading to a sharp change in the character of the LCS at
the bottom of the mixed layer. The flow behavior revealed by the LCS limits
fluid exchange between the WCR and the surrounding ocean, contributing to the
long life of WCRs. Further study of these structures and their associated
transport behavior may lead to further insights into the development and
persistence of such geophysical vortices as well as their transport behavior.


title: Converging bounds for the effective shear speed in 2D phononic crystals

abstract:
  Calculation of the effective quasistatic shear speed $c$ in 2D solid phononic
crystals is analyzed. The plane-wave expansion (PWE) and the monodromy-matrix
(MM) methods are considered. For each method, the stepwise sequence of upper
and lower bounds is obtained which monotonically converges to the exact value
of $c$. It is proved that the two-sided MM bounds of $c$ are tighter and their
convergence to $c$ is uniformly faster than that of the PWE bounds. Examples of
the PWE and MM bounds of effective speed versus concentration of high-contrast
inclusions are demonstrated.


title: Representing Code History with Development Environment Events

abstract:
  Modern development environments handle information about the intent of the
programmer: for example, they use abstract syntax trees for providing
high-level code manipulation such as refactorings; nevertheless, they do not
keep track of this information in a way that would simplify code sharing and
change understanding. In most Smalltalk systems, source code modifications are
immediately registered in a transaction log often called a ChangeSet. Such
mechanism has proven reliability, but it has several limitations. In this paper
we analyse such limitations and describe scenarios and requirements for
tracking fine-grained code history with a semantic representation. We present
Epicea, an early prototype implementation. We want to enrich code sharing with
extra information from the IDE, which will help understanding the intention of
the changes and let a new generation of tools act in consequence.


title: Complex Langevin Dynamics for chiral Random Matrix Theory

abstract:
  We apply complex Langevin dynamics to chiral random matrix theory at nonzero
chemical potential. At large quark mass the simulations agree with the
analytical results while incorrect convergence is found for small quark masses.
The region of quark masses for which the complex Langevin dynamics converges
incorrectly is identified as the region where the fermion determinant
frequently traces out a path surrounding the origin of the complex plane during
the Langevin flow. This links the incorrect convergence to an ambiguity in the
Langevin force due to the presence of the logarithm of the fermion determinant
in the action.


title:
Well-posedness and scattering for a system of quadratic derivative
  nonlinear Schr\"odinger equations with low regularity initial data

abstract:
  In the present paper, we consider the Cauchy problem of a system of quadratic
derivative nonlinear Schr\"odinger equations which was introduced by M. Colin
and T. Colin (2004) as a model of laser-plasma interaction. The local existence
of the solution of the system in the Sobolev space $H^{s}$ for $s>d/2+3$ is
proved by M. Colin and T. Colin. We prove the well-posedness of the system with
low regularity initial data. For some cases, we also prove the well-posedness
and the scattering at the scaling critical regularity by using $U^{2}$ space
and $V^{2}$ space which are applied to prove the well-posedness and the
scattering for KP-II equation at the scaling critical regularity by Hadac, Herr
and Koch (2009).


title:
Dirichlet space of multiply connected domains with Weil-Petersson class
  boundaries

abstract:
  The restricted class of quasicircles sometimes called the
"Weil-Petersson-class" has been a subject of interest in the last decade. In
this paper we establish a Sokhotski-Plemelj jump formula for WP-class
quasicircles, for boundary data in a certain conformally invariant Besov space.
We show that this Besov space is precisely the set of traces on the boundary of
harmonic functions of finite Dirichlet energy on the WP-class quasidisk.
  We apply this result to multiply connected domains, Sigma, which are the
complement of n+1 WP-class quasidisks. Namely, we give a bounded isomorphism
between the Dirichlet space D(Sigma) of Sigma and a direct sum of Dirichlet
spaces, D-, of the unit disk. Writing the quasidisks as images of the disk
under conformal maps (f_0,...,f_n), we also show that {(h \circ f_0,...,h \circ
f_n) : h \in D(Sigma)} is the graph of a certain bounded Grunsky operator on
D-.


title: Aharonov-Bohm Effect and Hidden Photons

abstract:
  Signs of hypothetical light gauge bosons from a hidden sector may appear in
Aharonov-Bohm-like experiments. The absence of signal in carried on experiments
allow us to set a modest constraint to the mass and coupling constant of these
particles. Our findings open the possibility to exploit the leaking of hidden
magnetic field in a different setup of experiments.


title:
Are Wolf-Rayet stars able to pollute the interstellar medium of
  galaxies? Results from the integral field spectroscopy

abstract:
  We investigate the spatial distribution of chemical abundances in a sample of
low metallicity Wolf-Rayet (WR) galaxies selected from the SDSS. We used the
integral field spectroscopy technique in the optical spectral range (3700-6850
AA) with PMAS attached to the CAHA 3.5 m telescope. Our statistical analysis of
the spatial distributions of O/H and N/O, as derived using the direct method or
strong-line parameters consistent with it, indicates that metallicity is
homogeneous in five out of the six analysed objects in scales of the order of
several kpc. Only in the object WR404, a gradient of metallicity is found in
the direction of the low surface brightness tail. In contrast,we found an
overabundance of N/O in spatial scales of the order of hundreds of pc
associated with or close to the positions of the WR stars in 4 out of the 6
galaxies. We exclude possible hydrodynamical causes, such as the metal-poor gas
inflow, for this local pollution by means of the analysis of the
mass-metallicity relation (MZR) and mass-nitrogen-to-oxygen relation (MNOR) for
the WR galaxies catalogued in the SDSS.


title: Genetics of polynomials over local fields

abstract:
  Let $(K,v)$ be a discrete valued field with valuation ring $\oo$, and let
$\oo_v$ be the completion of $\oo$ with respect to the $v$-adic topology. In
this paper we discuss the advantages of manipulating polynomials in $\oo_v[x]$
in a computer by means of OM representations of prime (monic and irreducible)
polynomials. An OM representation supports discrete data characterizing the
Okutsu equivalence class of the prime polynomial. These discrete parameters are
a kind of DNA sequence common to all individuals in the same Okutsu class, and
they contain relevant arithmetic information about the polynomial and the
extension of $K_v$ that it determines.


title: Conjugacy in Artin groups of extra-large type

abstract:
  We describe a constructive, cubic time solution to the conjugacy problem in
Artin groups of extra-large type, which was proved solvable in those groups by
Appel and Schupp. We use results from two of our previous papers that
characterise geodesic words in those groups, as well as the description of
conjugacy between elements involving three or more generators that is given by
Appel and Schupp.


title: The height of random $k$-trees and related branching processes

abstract:
  We consider the height of random k-trees and k-Apollonian networks. These
random graphs are not really trees, but instead have a tree-like structure. The
height will be the maximum distance of a vertex from the root. We show that
w.h.p. the height of random k-trees and k-Apollonian networks is asymptotic to
clog t, where t is the number of vertices, and c=c(k) is given as the solution
to a transcendental equation. The equations are slightly different for the two
types of process. In the limit as k-->oo the height of both processes is
asymptotic to log t/(k log 2).


title:
Error estimates for approximations of nonhomogeneous nonlinear uniformly
  elliptic equations

abstract:
  We obtain an error estimate between viscosity solutions and \delta-viscosity
solutions of nonhomogeneous fully nonlinear uniformly elliptic equations. The
main assumption, besides uniform ellipticity, is that the nonlinearity is
Lipschitz-continuous in space with linear growth in the Hessian. We also
establish a rate of convergence for monotone and consistent finite difference
approximation schemes for such equations.


title:
On Stein's method for products of normal random variables and zero bias
  couplings

abstract:
  In this paper we extend Stein's method to the distribution of the product of
$n$ independent mean zero normal random variables. A Stein equation is obtained
for this class of distributions, which reduces to the classical normal Stein
equation in the case $n=1$. This Stein equation motivates a generalisation of
the zero bias transformation. We establish properties of this new
transformation, and illustrate how they may be used together with the Stein
equation to assess distributional distances for statistics that are
asymptotically distributed as the product of independent central normal random
variables. We end by proving some product normal approximation theorems.


title: Music Files Search System

abstract:
  This paper introduces a project of advanced system of music retrieval from
the Internet. The system uses combination of text search (by author, title and
other information about the music file included in id3 tag description or
similar for other file types) with more intuitive and novel method of melody
search using query by humming. The patterns for storing text and melody
information as well as improved clustering algorithm for the pattern space were
proposed. The search engine is planned to optimise the query due to the data
input by user, thanks to the structure of text and melody index database. The
system is planned to be a plug-in for popular digital music players or an
independent player. An advanced system of recommendation based on information
gathered from user's profile and search history is an integral part of the
system. The recommendation mechanism uses scrobbling methods and is responsible
for making suggestions of songs unknown to the user but similar to his
preferred music styles and positioning search results.


title:
Sequential motion planning of non-colliding particles in Euclidean
  spaces

abstract:
  In terms of Rudyak's generalization of Farber's topological complexity of the
path motion planning problem in robotics, we give a complete description of the
topological instabilities in any sequential motion planning algorithm for a
system consisting of non-colliding autonomous entities performing tasks in
space whilst avoiding collisions with several moving obstacles. The Isotopy
Extension Theorem from manifold topology implies, somewhat surprisingly, that
the complexity of this problem coincides with the complexity of the
corresponding problem in which the obstacles are stationary.


title: On the prime divisors of elements of a $D(-1)$ quadruple

abstract:
  We show that if {1, b, c, d} is a D(-1) diophantine quadruple with b<c<d and
c=1+s^2, then the cases s=p^k, s=2p^k, c=p and c=2p^k do not occur, where p is
an odd prime and k is a positive integer. For the integer d=1+x^2, we show that
it is not prime and that x is divisible by at least two distinct odd primes.
Furthermore, we present several infinite families of integers b such that the
D(-1) pair {1, b} cannot be extended to a D(-1) quadruple. For instance, we
show that if r=5p where p is an odd prime, then the D(-1) pair {1, r^2+1}
cannot be extended to a D(-1) quadruple.