title:
Young stellar population and ongoing star formation in the HII complex
  Sh2-252

abstract:
  In this paper an extensive survey of the star forming complex Sh2-252 has
been undertaken with an aim to explore its hidden young stellar population as
well as to understand the structure and star formation history. This complex is
composed of five embedded clusters associated with the sub-regions A, C, E, NGC
2175s and Teu 136. Using 2MASS-NIR and Spitzer-IRAC, MIPS photometry we
identified 577 young stellar objects (YSOs), of which, 163 are Class I, 400 are
Class II and 14 are transition disk YSOs. Spatial distribution of the candidate
YSOs shows that they are mostly clustered around the sub-regions in the western
half of the complex, suggesting enhanced star formation activity towards its
west. Using the spectral energy distribution and optical colour-magnitude
diagram based age analyses, we derived probable evolutionary status of the
sub-regions of Sh2-252. Our analysis shows that the region A is the youngest (~
0.5 Myr), the regions B, C and E are of similar evolutionary stage (~ 1-2 Myr)
and the clusters NGC 2175s and Teu 136 are slightly evolved (~ 2-3 Myr).
Morphology of the region in the 1.1 mm map shows a semi-circular shaped
molecular shell composed of several clumps and YSOs bordering the western
ionization front of Sh2-252. Our analyses suggest that next generation star
formation is currently under way along this border and that possibly
fragmentation of the matter collected during the expansion of the HII region as
one of the major processes responsible for such stars. We observed the densest
concentration of YSOs (mostly Class I, ~ 0.5 Myr) at the western outskirts of
the complex, within a molecular clump associated with water and methanol masers
and we suggest that it is indeed a site of cluster formation at a very early
evolutionary stage, sandwiched between the two relatively evolved CHII regions
A and B.


title: The degree of the algebra of covariants of a binary form

abstract:
  We calculate the degree of the algebra of covariants $\mathcal{C}_d$ for
binary $d$-form. Also, for the degree we obtain its integral representation and
asymptotic behavior.


title:
Tandem Photonic-Crystal Thin Films Surpassing Lambertian Light-Trapping
  Limit over Broad Bandwidth and Angular Range

abstract:
  Random surface texturing of an optically-thick film to increase the path
length of scattered light rays, first proposed nearly thirty years ago, has
thus far remained the most effective approach for photon absorption over the
widest set of conditions. Here using recent advances in computational
electrodynamics we describe a general strategy for the design of a silicon thin
film applicable to photovoltaic cells based on a quasi-resonant approach to
light trapping where two partially-disordered photonic-crystal slabs, stacked
vertically on top of each other, have large absorption that surpasses the
Lambertian limit over a broad bandwidth and angular range.


title:
Minimum Latency Broadcast Scheduling in Single-Radio Multi-Channel
  Wireless Ad-Hoc Networks

abstract:
  We study the minimum latency broadcast scheduling (MLBS) problem in
Single-Radio Multi-Channel (SR-MC) wireless ad-hoc networks (WANETs), which are
modeled by Unit Disk Graphs. Nodes with this capability have their fixed
reception channels, but can switch their transmission channels to communicate
with their neighbors. The single-radio and multi-channel model prevents
existing algorithms for single-channel networks achieving good performance.
First, the common assumption that one transmission reaches all the neighboring
nodes does not hold naturally. Second, the multi-channel dimension provides new
opportunities to schedule the broadcast transmissions in parallel. We show MLBS
problem in SR-MC WANETs is NP-hard, and present a benchmark algorithm: Basic
Transmission Scheduling (BTS), which has approximation ratio of 4k + 12. Here k
is the number of orthogonal channels in SR-MC WANETs. Then we propose an
Enhanced Transmission Scheduling (ETS) algorithm, improving the approximation
ratio to k + 23. Simulation results show that ETS achieves better performance
over BTS, and the performance of ETS approaches the lower bound.


title:
On the nonlinear dynamics of a position-dependent mass-driven
  Duffing-type oscillator: Lagrange and Newton equations' equivalence

abstract:
  Using a generalized coordinate along with a proper invertible coordinate
transformation, we show that the Euler-Lagrange equation used by Bagchi et al.
16 is in clear violation of the Hamilton's principle. We also show that
Newton's equation of motion they have used is not in a form that satisfies the
dynamics of position-dependent mass (PDM) settings.. The equivalence between
Euler-Lagrange's and Newton's equations is now proved and documented through
the proper invertible coordinate transformation and the introduction of a new
PDM byproducted reaction-type force. The total mechanical energy for the PDM is
shown to be conservative (i.e., dE/dt=0, unlike Bagchi et al.'s 16
observation).


title: Vortices and turbulence in trapped atomic condensates

abstract:
  After over a decade of experiments generating and studying the physics of
quantized vortices in atomic gas Bose-Einstein condensates, research is
beginning to focus on the roles of vortices in quantum turbulence, as well as
other measures of quantum turbulence in atomic condensates. Such research
directions have the potential to uncover new insights into quantum turbulence,
vortices and superfluidity, and also explore the similarities and differences
between quantum and classical turbulence in entirely new settings. Here we
present a critical assessment of theoretical and experimental studies in this
emerging field of quantum turbulence in atomic condensates.


title: Fluid flow dynamics under location uncertainty

abstract:
  We present a derivation of a stochastic model of Navier Stokes equations that
relies on a decomposition of the velocity fields into a differentiable drift
component and a time uncorrelated uncertainty random term. This type of
decomposition is reminiscent in spirit to the classical Reynolds decomposition.
However, the random velocity fluctuations considered here are not
differentiable with respect to time, and they must be handled through
stochastic calculus. The dynamics associated with the differentiable drift
component is derived from a stochastic version of the Reynolds transport
theorem. It includes in its general form an uncertainty dependent "subgrid"
bulk formula that cannot be immediately related to the usual Boussinesq eddy
viscosity assumption constructed from thermal molecular agitation analogy. This
formulation, emerging from uncertainties on the fluid parcels location,
explains with another viewpoint some subgrid eddy diffusion models currently
used in computational fluid dynamics or in geophysical sciences and paves the
way for new large-scales flow modelling. We finally describe an applications of
our formalism to the derivation of stochastic versions of the Shallow water
equations or to the definition of reduced order dynamical systems.


title:
Optimization of Spectrum Allocation and Subsidization in Mobile
  Communication Services

abstract:
  Mobile traffic explosion causes spectrum shortage and polarization of data
usage among users, which will eventually decrease user welfare in mobile
communication services. Governments around the world are planning to make more
spectrum available for mobile broadband use, and the key policy issue is to
find an efficient spectrum allocation method that will improve user welfare. In
this paper, we propose a data subsidy scheme where the regulator offers a
spectrum price discount to mobile network operators (MNOs) in return for
imposing the responsibility of providing a predefined data amount to users free
of charge. To analyze the subsidy effect, we adopt the two-stage approach of
Cournot and Bertrand competition, and find a Nash equilibrium of the
competition. An interesting observation is that the increase in user welfare
does not involve MNO profit loss and the increasing amount is higher than the
regulator's expenses for implementing the data subsidy scheme. The most of the
paper is for the duopoly competition, which is extended to the general case,
finally.


title: Coherent X-ray Diffraction Imaging of Nanostructures

abstract:
  We present here an overview of Coherent X-ray Diffraction Imaging (CXDI) with
its application to nanostructures. This imaging approach has become especially
important recently due to advent of X-ray Free-Electron Lasers (XFEL) and its
applications to the fast developing technique of serial X-ray crystallography.
We start with the basic description of coherent scattering on the finite size
crystals. The difference between conventional crystallography applied to large
samples and coherent scattering on the finite size samples is outlined. The
formalism of coherent scattering from a finite size crystal with a strain field
is considered. Partially coherent illumination of a crystalline sample is
developed. Recent experimental examples demonstrating applications of CXDI to
the study of crystalline structures on the nanoscale, including experiments at
FELs, are also presented.


title: Legacy Forensics: An Emerging Challenge

abstract:
  With the passage of time and as new types of storage devices are introduced
into the marketplace, contemporary devices will slowly lose their compatibility
with current operating systems and PC hardware. As a result, such legacy
devices will pose an analytical challenge to the field of digital forensics.
Dated technology, while still fully functional, is becoming increasingly
incompatible with most contemporary computing hardware and software and thus
cannot be properly examined in present-day digital forensic environments. This
fact will not be lost on those who utilize legacy hardware to commit criminal
acts. This paper describes the technical challenge of accessing legacy devices
by describing an effort to resuscitate a Bernoulli Drive, a portable storage
device manufactured in 1983 by Iomega Corporation. A number of lessons-learned
are provided and the implication of legacy devices to digital forensic science
is discussed.


title: The Convexity of the Free Boundary for the American put option

abstract:
  This paper studies the parabolic free boundary problem arising from pricing
American-style put options on an asset whose index follows a geometric Brownian
motion process. The contribution is to propose a condition for that the early
exercise boundary is a convex function.


title: Classification of subgroups isomorphic to PSL_2(27) in the Monster

abstract:
  We prove that the Monster does not contain any subgroup isomorphic to
PSL_2(27).


title:
Hyperon-nucleon interaction at next-to-leading order in chiral effective
  field theory

abstract:
  Results for the Lambda N and Sigma N interactions obtained at next-to-leading
order in chiral effective field theory are reported. At the order considered
there are contributions from one- and two-pseudoscalar-meson exchange diagrams
and from four-baryon contact terms without and with two derivatives. SU(3)
flavor symmetry is imposed for constructing the hyperon-nucleon interaction
while the explicit SU(3) symmetry breaking by the physical masses of the
pseudoscalar mesons (pi, K, eta) is taken into account. An excellent
description of the hyperon-nucleon system can be achieved at next-to-leading
order. It is on the same level of quality as the one obtained by the most
advanced phenomenological hyperon-nucleon interaction models.


title:
An entropy perspective on the thermal crossover in a fermionic Hubbard
  chain

abstract:
  We study the Renyi entropy in the finite temperature crossover regime of a
Hubbard chain using quantum Monte Carlo. The ground state entropy has
characteristic features such as a logarithmic divergence with block size and
$2\kF$ oscillations that are a hallmark of its Luttinger liquid nature. The
interplay between the (extensive) thermal entropy and the ground state features
is studied and we analyze the temperature induced decay of the amplitude of the
oscillations as well as the scaling of the purity. Furthermore, we show how the
spin and charge velocities can be extracted from the temperature dependence of
the Renyi entropy, bridging our findings to recent experimental proposals on
how to implement the measurement of Renyi entropies in cold atom system.
Studying the Renyi mutual information, we also demonstrate how constraints such
as particle number conservation can induce persistent correlations visible in
the mutual information even at high temperature.


title: Monte-Carlo Simulations for the optimisation of a TOF-MIEZE Instrument

abstract:
  The MIEZE (Modulation of Intensity with Zero Effort) technique is a variant
of neutron resonance spin echo (NRSE), which has proven to be a unique neutron
scattering technique for measuring with high energy resolution in magnetic
fields. Its limitations in terms of flight path differences have already been
investigated analytically for neutron beams with vanishing divergence. In the
present work Monte-Carlo simulations for quasi-elastic MIEZE experiments taking
into account beam divergence as well as the sample dimensions are presented.
One application of the MIEZE technique could be a dedicated NRSE-MIEZE
instrument at the European Spallation Source (ESS) in Sweden. The optimisation
of a particular design based on Montel mirror optics with the help of Monte
Carlo simulations will be discussed here in detail.


title: Modular forms in Quantum Field Theory

abstract:
  The amplitude of a Feynman graph in Quantum Field Theory is related to the
point-count over finite fields of the corresponding graph hypersurface. This
article reports on an experimental study of point counts over F_q modulo q^3,
for graphs up to loop order 10. It is found that many of them are given by
Fourier coefficients of modular forms of weights <=8 and levels <=17.


title: High rigidity Forbush decreases: due to CMEs or shocks?

abstract:
  We seek to identify the primary agents causing Forbush decreases (FDs)
observed at the Earth in high rigidity cosmic rays. In particular, we ask if
such FDs are caused mainly by coronal mass ejections (CMEs) from the Sun that
are directed towards the Earth, or by their associated shocks. We use the muon
data at cutoff rigidities ranging from 14 to 24 GV from the GRAPES-3 tracking
muon telescope to identify FD events. We select those FD events that have a
reasonably clean profile, and can be reasonably well associated with an
Earth-directed CME and its associated shock. We employ two models: one that
considers the CME as the sole cause of the FD (the CME-only model) and one that
considers the shock as the only agent causing the FD (the shock-only model). We
use an extensive set of observationally determined parameters for both these
models. The only free parameter in these models is the level of MHD turbulence
in the sheath region, which mediates cosmic ray diffusion (into the CME, for
the CME-only model and across the shock sheath, for the shock-only model).
  We find that good fits to the GRAPES-3 multi-rigidity data using the CME-only
model require turbulence levels in the CME sheath region that are only slightly
higher than those estimated for the quiet solar wind. On the other hand,
reasonable model fits with the shock-only model require turbulence levels in
the sheath region that are an order of magnitude higher than those in the quiet
solar wind.
  This observation naturally leads to the conclusion that the Earth-directed
CMEs are the primary contributors to FDs observed in high rigidity cosmic rays.


title: Helical networks in twisted bilayer graphene under interlayer bias

abstract:
  A twisted graphene bilayer exhibits a triangular Moir\'e pattern in the local
stacking, that smoothly alternates between the three basic types AA', AB' and
BA'. Under an interlayer bias U, the latter two types develop a spectral gap,
characterised by opposite valley Chern numbers. We show that for large enough
Moir\'e periods and bias, these regions become depleted electronically, and
topologically protected helical modes appear at their boundaries. This gives
rise to a delocalised topological network of the Chalker-Coddington type,
composed of valley current vortices. This network can be tailored by controlled
deposition of valley-mixing adsorbates, which block transmission in selected
links, thus opening the possibility of custom topological nanoelectronics.


title:
Interplay of total cross sections and ratios of real to imaginary parts
  of hadron amplitudes

abstract:
  The impact of different assumptions about high energy behavior of the total
cross section of proton-proton interactions on the ratio of the real to
imaginary part of the forward elastic scattering amplitude is analyzed. It is
shown how experimental data about this ratio at LHC energies can help in the
proper choice of the asymptotic dependence of the total cross section.


title:
Marketplaces for Energy Demand-Side Management based on Future-Internet
  Technology

abstract:
  Renewable energies become more important, and they contribute to the EU's
goals for greenhouse-gas reduction. However, their fluctuating nature calls for
demand-side-management techniques, which balance energy generation and
consumption. Such techniques are currently not broadly deployed. This paper
describes the latest results from the FINSENY project on how Future-Internet
enablers and market mechanisms can be used to realise such systems.


title: Renormalization group functions of QCD in the minimal MOM scheme

abstract:
  We provide the full set of renormalization group functions for the
renormalization of QCD in the minimal MOM scheme to four loops for the colour
group SU(N_c).


title:
Power-law scaling of asymmetries in viscous flow with PT-symmetric
  inflow and outflow

abstract:
  In recent years, open systems with balanced loss and gain, that are invariant
under the combined parity and time-reversal ($\mathcal{PT}$) operations, have
been studied via asymmetries of their solutions. They represent systems as
diverse as coupled optical waveguides and electrical or mechanical oscillators.
We numerically investigate the asymmetries of incompressible viscous flow in
two and three dimensions with "balanced" inflow-outflow
($\mathcal{PT}$-symmetric) configurations. By introducing
configuration-dependent classes of asymmetry functions in velocity, kinetic
energy density, and vorticity fields, we find that the flow asymmetries exhibit
power-law scaling with a single exponent in the laminar regime with the
Reynolds number ranging over four decades. We show that such single-exponent
scaling is expected for small Reynolds numbers, although its robustness at
large values of Reynolds numbers is unexpected. Our results imply that
$\mathcal{PT}$-symmetric inflow-outflow configurations provide a hitherto
unexplored avenue to tune flow properties.


title:
Robust VIF regression with application to variable selection in large
  data sets

abstract:
  The sophisticated and automated means of data collection used by an
increasing number of institutions and companies leads to extremely large data
sets. Subset selection in regression is essential when a huge number of
covariates can potentially explain a response variable of interest. The recent
statistical literature has seen an emergence of new selection methods that
provide some type of compromise between implementation (computational speed)
and statistical optimality (e.g., prediction error minimization). Global
methods such as Mallows' $C_p$ have been supplanted by sequential methods such
as stepwise regression. More recently, streamwise regression, faster than the
former, has emerged. A recently proposed streamwise regression approach based
on the variance inflation factor (VIF) is promising, but its least-squares
based implementation makes it susceptible to the outliers inevitable in such
large data sets. This lack of robustness can lead to poor and suboptimal
feature selection. In our case, we seek to predict an individual's educational
attainment using economic and demographic variables. We show how classical VIF
performs this task poorly and a robust procedure is necessary for policy
makers. This article proposes a robust VIF regression, based on fast robust
estimators, that inherits all the good properties of classical VIF in the
absence of outliers, but also continues to perform well in their presence where
the classical approach fails.


title:
Parallel Gaussian Process Optimization with Upper Confidence Bound and
  Pure Exploration

abstract:
  In this paper, we consider the challenge of maximizing an unknown function f
for which evaluations are noisy and are acquired with high cost. An iterative
procedure uses the previous measures to actively select the next estimation of
f which is predicted to be the most useful. We focus on the case where the
function can be evaluated in parallel with batches of fixed size and analyze
the benefit compared to the purely sequential procedure in terms of cumulative
regret. We introduce the Gaussian Process Upper Confidence Bound and Pure
Exploration algorithm (GP-UCB-PE) which combines the UCB strategy and Pure
Exploration in the same batch of evaluations along the parallel iterations. We
prove theoretical upper bounds on the regret with batches of size K for this
procedure which show the improvement of the order of sqrt{K} for fixed
iteration cost over purely sequential versions. Moreover, the multiplicative
constants involved have the property of being dimension-free. We also confirm
empirically the efficiency of GP-UCB-PE on real and synthetic problems compared
to state-of-the-art competitors.


title: Sidon Basis

abstract:
  Erd\"os conjectured the existence of an infinite Sidon sequence of positive
integers which is also an asymptotic basis of order 3. We make progress towards
this conjecture in several directions. First we prove the conjecture for all
cyclic groups Z_N with N large enough. In second place we prove by
probabilistic methods that there is an infinite B_2[2] sequence which is an
asymptotic basis of order 3. Finally we prove that for all c>0 there is a Sidon
sequence which is an asymptotic basis of order 3+c,that is to say, any positive
sufficiently large integer n can be written as a sum of 4 elements of the
sequence, one of them smaller than n^c.


title: On Thompson's $p$-complement theorems for saturated fusion systems

abstract:
  In this short note we prove that a saturated fusion system admitting some
special type of automorphism is nilpotent. This generalizes classical results
by J.G. Thompson.


title:
Embedding the 125 GeV Higgs boson measured at the LHC in an effective
  MSSM: possible implications for neutralino dark matter

abstract:
  We analyze the phenomenological consequences of assuming that the 125 GeV
boson measured at the LHC coincides with one of the two CP-even Higgs bosons of
an effective Minimal Supersymmetric extension of the Standard Model at the
electroweak scale. We consider the two ensuing scenarios and discuss critically
the role of the various experimental data (mainly obtained at colliders and at
B-factories) which provide actual or potential constraints to supersymmetric
properties. Within these scenarios, properties of neutralinos as dark matter
particles are analyzed from the point of view of their cosmological abundance
and rates for direct and indirect detections.


title:
Properties of the UCHII region G25.4NW and its associated molecular
  cloud

abstract:
  UCHII G25.4NW is a bright IR source in the inner Galaxy region.
  New HI images from the VLA Galactic Plane Survey (VGPS) show clear absorption
features associated with the UCHII region up to 95 km s$^{-1}$, and there is
not any other absorptions up to the tangential velocity.
  It reveals that G25.4NW is at a near-side distance of 5.7 kpc, and it is
located in the inner Galactic molecular ring region.
  Using the new distance, the bolometric luminosity of G25.4NW is estimated as
$10^{5.6} L_{\odot}$, which corresponds to an O6 star.
  It contains 460 $M_{\odot}$ of ionized gas. High-resolution $^{13}$CO image
from the Galactic Ring Survey (GRS) reveals that G25.4NW is part of a more
extended star-formation complex with about $10^{4} M_{\odot}$ molecular gas.


title:
Electron-phonon coupling in 122 Fe pnictides analyzed by femtosecond
  time-resolved photoemission

abstract:
  Based on results from femtosecond time-resolved photoemission, we compare
three different methods for determination of the electron-phonon coupling
constant {\lambda} in Eu and Ba-based 122 FeAs compounds. We find good
agreement between all three methods, which reveal a small {\lambda} < 0.2. This
makes simple electron-phonon mediated superconductivity unlikely in these
compounds.


title: First observation of PeV-energy neutrinos with IceCube

abstract:
  We report on the observation of two neutrino-induced events which have an
estimated deposited energy in the IceCube detector of 1.04 $\pm$ 0.16 and 1.14
$\pm$ 0.17 PeV, respectively, the highest neutrino energies observed so far.
These events are consistent with fully contained particle showers induced by
neutral-current $\nu_{e,\mu,\tau}$ ($\bar\nu_{e,\mu,\tau}$) or charged-current
$\nu_{e}$ ($\bar\nu_{e}$) interactions within the IceCube detector. The events
were discovered in a search for ultra-high energy neutrinos using data
corresponding to 615.9 days effective livetime. The expected number of
atmospheric background is $0.082 \pm 0.004 \text{(stat)}^{+0.041}_{-0.057}
\text{(syst)}$. The probability to observe two or more candidate events under
the atmospheric background-only hypothesis is $2.9\times10^{-3}$ ($2.8\sigma$)
taking into account the uncertainty on the expected number of background
events. These two events could be a first indication of an astrophysical
neutrino flux, the moderate significance, however, does not permit a definitive
conclusion at this time.


title: Exact-Regenerating Codes between MBR and MSR Points

abstract:
  In this paper we study distributed storage systems with exact repair. We give
a construction for regenerating codes between the minimum storage regenerating
(MSR) and the minimum bandwidth regenerating (MBR) points and show that in the
case that the parameters n, k, and d are close to each other our constructions
are close to optimal when comparing to the known capacity when only functional
repair is required. We do this by showing that when the distances of the
parameters n, k, and d are fixed but the actual values approach to infinity,
the fraction of the performance of our codes with exact repair and the known
capacity of codes with functional repair approaches to one.


title: First measurements with the Munich 2D-ACAR spectrometer on Cr

abstract:
  The Munich 2D-ACAR spectrometer at the Maier-Leibnitz accelerator laboratory
in Garching has recently become operational. In the present implementation a
2D-ACAR spectrometer is set up, with a baseline of 16.5m, a conventional 22Na
positron source and two Anger-type gamma-cameras. The positrons are guided onto
the sample by a magnetic field generated by a normal conducting electromagnet.
The sample can be either cooled by a standard closed-cycle-cryostat to low
temperatures or heated by a resistive filament to temperatures up to 500K. We
present the key features of this new 2D-ACAR spectrometer and, in addition,
discuss first measurements on the pure metal system Cr. The 2D-ACAR
measurements have been performed on Cr at different temperatures: at 5K and at
room temperature in the anti-ferromagnetic phase and at 318K slightly above the
paramagnetic phase transition.


title:
Euclidean spaces as weak tangents of infinitesimally Hilbertian metric
  spaces with Ricci curvature bounded below

abstract:
  We show that in any infinitesimally Hilbertian $CD^*(K,N)$-space at almost
every point there exists a Euclidean weak tangent, i.e. there exists a sequence
of dilations of the space that converges to a Euclidean space in the pointed
measured Gromov-Hausdorff topology. The proof follows by considering iterated
tangents and the splitting theorem for infinitesimally Hilbertian
$CD^*(0,N)$-spaces.


title:
Understanding the re-entrant superconducting phase diagram of an
  iron-pnictide Ca$_4$Al$_2$O$_6$Fe$_2$(As$_{1-x}$P$_x$)$_2$

abstract:
  Recently, a very rich phase diagram has been obtained for an iron-based
superconductor Ca4Al2O6Fe2(As1-xPx)2. It has been revealed that nodeless (x=0)
and nodal (x = 1) superconductivity are separated by an antiferromagnetic
phase. Here we study the origin of this peculiar phase diagram using a five
orbital model constructed from first principles band calculation, and applying
the fluctuation exchange approximation assuming spin fluctuation mediated
pairing. Based on the calculation results, we propose a scenario where the
frustration in momentum space degrades superconductivity in the intermediate x
regime, while antiferromangetism takes place due to a very good nesting. In
order to see whether the present theoretical scenario is consistent with the
actual nature of the competition between superconductivity and
antiferromagnetism, we also perform hydrostatic pressure experiment for
Ca4Al2O6Fe2(As1-xPx)2. In the intermediate x regime where antiferromagnetism
occurs at ambient pressure, applying hydrostatic pressure smears out the
antiferromagnetic transition, but superconductivity does not take place. This
supports our scenario that superconductivity is suppressed by the momentum
space frustration in the intermediate x regime, apart from the presence of the
antiferromangnetism.


title:
First-principle calculation of solar cell efficiency under incoherent
  illumination

abstract:
  Because of the temporal incoherence of sunlight, solar cells efficiency
should depend on the degree of coherence of the incident light. However,
numerical computation methods, which are used to optimize these devices,
fundamentally consider fully coherent light. Hereafter, we show that the
incoherent efficiency of solar cells can be easily analytically calculated. The
incoherent efficiency is simply derived from the coherent one thanks to a
convolution product with a function characterizing the incoherent light. Our
approach is neither heuristic nor empiric but is deduced from first-principle,
i.e. Maxwell's equations. Usually, in order to reproduce the incoherent
behavior, statistical methods requiring a high number of numerical simulations
are used. With our method, such approaches are not required. Our results are
compared with those from previous works and good agreement is found.


title:
Meson vacuum phenomenology in a three-flavor linear sigma model with
  (axial-)vector mesons: investigation of the U(1)_A anomaly term

abstract:
  Zero temperature properties of an (axial-) vector meson extended linear sigma
model are discussed, concerning on the possible different realizations of the
axial anomaly term. The different anomaly terms are compared with each other on
the basis of a chi^2 minimalization process. It is found that there is no
essential difference among the different realizations. This means that any of
them can be equally used from phenomenological point of view.


title: First 2D-ACAR Measurements on Cu with the new Spectrometer at TUM

abstract:
  The two-dimensional measurement of the angular correlation of the positron
annihilation radiation (2D-ACAR) is a powerful tool to investigate the
electronic structure of materials. Here we report on the first results obtained
with the new 2D-ACAR spectrometer at the Technische Universit\"at M\"unchen
(TUM). To get experience in processing and interpreting 2D-ACAR data, first
measurements were made on copper. The obtained data are treated with standard
procedures and compared to theoretical calculations. It is shown that the
measurements are in good agreement with the calculations and that the Fermi
surface can be entirely reconstructed using three projections only.


title:
Optimized hydrogen sensing properties of nanocomposite NiO:Au thin films
  grown by dual Pulsed Laser Deposition

abstract:
  Nanocomposite NiO:Au thin films, formed by gold nanoparticles embedded in a
nickel oxide matrix, have been grown by reactive pulsed laser deposition
(R-PLD). Two actively synchronized nanosecond laser sources, a KrF excimer
laser (248 nm) and a Nd:YAG laser (355 nm), were used for the simultaneous
ablation of nickel and gold targets in oxygen ambient. The morphology,
composition, and optical properties of the obtained nanocomposites were
investigated and were found to correlate with the concentration of Au
nanoparticles. Further, the NiO:Au nanocomposites have been tested as hydrogen
sensors. Embedding Au nanoparticles into the NiO film matrix reduced the
sensors operating temperature and improved their performance by orders of
magnitude.


title: A new proof of a Bismut-Zhang formula for some class of representations

abstract:
  Bismut and Zhang computed the ratio of the Ray-Singer and the combinatorial
torsions corresponding to non-unitary representations of the fundamental group.
In this note we show that for representations which belong to a connected
component containing a unitary representation the Bismut-Zhang formula follows
rather easily from the Cheeger-Mueller theorem, i.e. from the equality of the
two torsions on the set of unitary representations. The proof uses the fact
that the refined analytic torsion is a holomorphic function on the space of
representations.


title:
Multiple solutions for a quasilinear Schr\"{o}dinger equation on
  $\mathbb{R}^{N}$}

abstract:
  The multiplicity of positive weak solutions for a quasilinear Schr\"{o}dinger
equations $-L_p u +(\lambda A(x)+1)|u|^{p-2}u= h(u)$ in $\mathbb{R}^N$ is
established, where $L_p u\doteq \epsilon^{p}\Delta_p u +\epsilon^{p}\Delta_p
(u^2)u$, $A$ is a nonnegative continuous function and nonlinear term $h$ has a
subcritical growth. We achieved our results by using minimax methods and
Lusternik-Schnirelman theory of critical points.


title: Molecular Environments of SNRs

abstract:
  There are about 70 Galactic supernova remnants (SNRs) that are now confirmed
or suggested to be in physical contact with molecular clouds (MCs) with six
kinds of evidence of multiwavelength observations. Recent detailed CO-line
spectroscopic mappings of a series of SNRs reveal them to be in cavities of
molecular gas, implying the roles the progenitors may have played. We predict a
linear correlation between the wind bubble sizes of main-sequence OB stars in a
molecular environment and the stellar masses and discuss its implication for
supernova progenitors. The molecular environments of SNRs can serve as a good
probe for the gamma-rays arising from the hadronic interaction of the
accelerated protons, and this paper also discusses the gamma-ray emission from
MCs illuminated by diffusive protons that escape from SNR shocks.


title:
Combining heavy quark spin and local hidden gauge symmetries in the
  dynamical generation of hidden charm baryons

abstract:
  We present a coupled channel unitary approach to obtain states dynamically
generated from the meson baryon interaction with hidden charm, using
constraints of heavy quark spin symmetry. We use as basis of states, $\bar D
B$, $\bar D^* B$ states, with $B$ baryon charmed states belonging to the 20
representations of SU(4) with $J^P=1/2^+,~3/2^+$. In addition we also include
the $\eta_c N$ and $J/\psi N$ states. The inclusion of these coupled channels
is demanded by heavy quark spin symmetry, since in the large $m_Q$ limit the
$D$ and $D^*$ states are degenerate and are obtained from each other by means
of a spin rotation, under which QCD is invariant. The novelty in the work is
that we use dynamics from the extrapolation of the local hidden gauge model to
SU(4) and we show that this dynamics fully respects the constraints of heavy
quark spin symmetry.
  With the full space of states demanded by the heavy quark spin symmetry and
the dynamics of the local hidden gauge we look for states dynamically generated
and find four basic states which are bound, corresponding to $\bar D \Sigma_c$,
$\bar D \Sigma_c^*$, $\bar D^* \Sigma_c$ and $\bar D^* \Sigma_c^*$, decaying
mostly into $\eta_c N$ and $J/\psi N$. All the states appear in isospin $I=1/2$
and we find no bound states or resonances in $I=3/2$. The $\bar D \Sigma_c$
state appears in $J=1/2$, the $\bar D \Sigma_c^*$ in $J=3/2$, the $\bar D^*
\Sigma_c$ appears nearly degenerate in $J=1/2, ~3/2$ and the $\bar D^*
\Sigma_c^*$ appears nearly degenerate in $J=1/2, ~3/2, ~5/2$, with the
peculiarity that in $J=5/2$ the state has zero width in the space of states
chosen. All the states are bound with about 50 MeV with respect to the
corresponding $\bar D B$ thresholds and the width, except for the $J=5/2$
state, is also of the same order of magnitude.


title:
Some new inequalities for trigonometric functions and corresponding ones
  for means

abstract:
  In this paper, the versions of trigonometric functions of certain known
inequalities for hyperbolic ones are proved, and then corresponding
inequalities for means are presented.


title:
Type-I X-ray bursts reveal a fast co-evolving behavior of the corona in
  an X-ray binary

abstract:
  The coronae in X-ray binaries (XRBs) still remain poorly understood, although
they have been believed for a long time to play a key role in modeling the
characteristic outbursts of XRBs. Type-I X-ray bursts, the thermonuclear
flashes happening on the surface of a neutron star (NS), can be used as a probe
to the innermost region of a NS XRB, where the corona is believed to be located
very close to the NS. We report the discovery of a tiny life cycle of the
corona that is promptly co-evolved with the type-I bursts superimposed on the
outburst of the NS XRB IGR J17473$-$2721. This finding may serve as the first
evidence of directly seeing the rapid disappearance and formation of a corona
in an XRB with a cooling/heating timescale of less than a second, which can
strongly constrain the accretion models in XRBs at work.


title: X-ray bursts as a probe of the corona: the case of XRB 4U 1636-536

abstract:
  To investigate the possible cooling of the corona by soft X-rays bursts, we
have studied 114 bursts embedded in the known X-ray evolution of 4U 1636-536.
We have grouped these bursts according to the ratio of the flux in the 1.5--12
keV band with respect to that in the 15--50 keV band, as monitored by RXTE/ASM
and Swift/BAT, respectively. We have detected a shortage at hard X-rays while
bursting. This provides hints for a corona cooling process driven by soft
X-rays fed by the bursts that occurred on the surface of neutron star. The flux
shortage at 30--50 keV has a time lag of 2.4$\pm$1.5 seconds with respect to
that at 2--10 keV, which is comparable to that of 0.7$\pm$0.5 seconds reported
in bursts of IGR 17473-2721. We comment on the possible origin of these
phenomena and on the implications for the models on the location of the corona.


title:
Formation of droplets with high baryon density at the QCD phase
  transition in expanding matter

abstract:
  We consider the (3+1) dimensional expansion and cooling of the
chirally-restored and deconfined matter at finite net-baryon densities as
expected in heavy-ion collisions at moderate energies. In our approach, we
consider chiral fields and the Polyakov loop as dynamical variables coupled to
a medium represented by a quark-antiquark fluid. The interaction between the
fields and the fluid leads to dissipation and noise, which in turn affect the
field fluctuations. We demonstrate how inhomogeneities in the net-baryon
density may form during an evolution through the spinodal region of the
first-order phase transition. For comparison, the dynamics of transition
through the crossover and critical end point is also considered.


title: Compact q-gram Profiling of Compressed Strings

abstract:
  We consider the problem of computing the q-gram profile of a string \str of
size $N$ compressed by a context-free grammar with $n$ production rules. We
present an algorithm that runs in $O(N-\alpha)$ expected time and uses
$O(n+q+\kq)$ space, where $N-\alpha\leq qn$ is the exact number of characters
decompressed by the algorithm and $\kq\leq N-\alpha$ is the number of distinct
q-grams in $\str$. This simultaneously matches the current best known time
bound and improves the best known space bound. Our space bound is
asymptotically optimal in the sense that any algorithm storing the grammar and
the q-gram profile must use $\Omega(n+q+\kq)$ space. To achieve this we
introduce the q-gram graph that space-efficiently captures the structure of a
string with respect to its q-grams, and show how to construct it from a
grammar.


title: Generalized Gibbs Ensemble for Heisenberg Spin Chains

abstract:
  We consider the Generalized Gibbs Ensemble (GGE) in the context of global
quantum quenches in XXZ Heisenberg spin chains. Embedding the GGE into the
Quantum Transfer Matrix formalism we develop an iterative procedure to fix the
Lagrange-multipliers and to calculate predictions for the long-time limit of
short-range correlators. The main idea is to consider truncated GGE's with only
a finite number of charges and to investigate the convergence of the numerical
results as the truncation level is increased. As an example we consider a
quantum quench situation where the system is initially prepared in the N\'eel
state and then evolves with an XXZ Hamiltonian with anisotropy Delta>1. We
provide predictions for short range correlators and gather numerical evidence
that the iterative procedure indeed converges. The results show that the system
retains memory of the initial condition, and there are clear differences
between the numerical values of the correlators as calculated from the purely
thermal and the Generalized Gibbs ensembles.


title: On the Shape Dependence of the Tangential Casimir Force

abstract:
  The normal and tangential Casimir force for the rack gear is calculated
numerically in the case of ideal boundary conditions for the electromagnetic
field - perfect reflection on the boundaries. The resulting tangential force
appears to be essentially shape dependent. Relatively small shape variations
lead to the essential changes in tangential force, whereas normal force remains
almost unchanged.


title: Calculabilit\'e de la cohomologie \'etale modulo l

abstract:
  Let $X$ be an algebraic scheme over an algebraically closed field and $\ell$
a prime number invertible on $X$. According to classical results (due
essentially to A. Grothendieck, M. Artin and P. Deligne), the \'etale
cohomology groups $\mathrm{H}^i(X,\mathbb{Z}/\ell\mathbb{Z})$ are
finite-dimensional. Using an $\ell$-adic variant of M. Artin's good
neighborhoods and elementary results on the cohomology of pro-$\ell$ groups, we
express the cohomology of $X$ as a well controlled colimit of that of toposes
constructed on $BG$ where the $G$ are computable finite $\ell$-groups. From
this, we deduce that the Betti numbers modulo $\ell$ of $X$ are algorithmically
computable (in the sense of Church-Turing). The proof of this fact, along with
certain related results, occupies the first part of this paper. This relies on
the tools collected in the second part, which deals with computational
algebraic geometry. Finally, in the third part, we present a "universal"
formalism for computation on the elements of a field.


title:
Bohr's absolute convergence problem for $\mathcal{H}_p$-Dirichlet series
  in Banach spaces

abstract:
  The Bohr-Bohnenblust-Hille Theorem states that the width of the strip in the
complex plane on which an ordinary Dirichlet series $\sum_n a_n n^{-s}$
converges uniformly but not absolutely is less than or equal to 1/2, and this
estimate is optimal. Equivalently, the supremum of the absolute convergence
abscissas of all Dirichlet series in the Hardy space $\mathcal{H}_\infty$
equals 1/2. By a surprising fact of Bayart the same result holds true if
$\mathcal{H}_\infty$ is replaced by any Hardy space $\mathcal{H}_p$, $1 \le p <
\infty$, of Dirichlet series. For Dirichlet series with coefficients in a
Banach space $X$ the maximal width of Bohr's strips depend on the geometry of
$X$; Defant, Garc\'ia, Maestre and P\'erez-Garc\'ia proved that such maximal
width equal $1- 1/\ct(X)$, where $\ct(X)$ denotes the maximal cotype of $X$.
Equivalently, the supremum over the absolute convergence abscissas of all
Dirichlet series in the vector-valued Hardy space $\mathcal{H}_\infty(X)$
equals $1- 1/\ct(X)$. In this article we show that this result remains true if
$\mathcal{H}_\infty(X)$ is replaced by the larger class $\mathcal{H}_p(X)$, $1
\le p < \infty$.


title: Fair Sets of Some Class of Graphs

abstract:
  Given a non empty set $S$ of vertices of a graph, the partiality of a vertex
with respect to $S$ is the difference between maximum and minimum of the
distances of the vertex to the vertices of $S$. The vertices with minimum
partiality constitute the fair center of the set. Any vertex set which is the
fair center of some set of vertices is called a fair set. In this paper we
prove that the induced subgraph of any fair set is connected in the case of
trees and characterise block graphs as the class of chordal graphs for which
the induced subgraph of all fair sets are connected. The fair sets of $K_{n}$,
$K_{m,n}$, $K_{n}-e$, wheel graphs, odd cycles and symmetric even graphs are
identified. The fair sets of the Cartesian product graphs are also discussed.


title:
A table-top laser-based source of femtosecond, collimated,
  ultra-relativistic positron beams

abstract:
  The generation of ultra-relativistic positron beams with short duration
($\tau_{e^+} \leq 30$ fs), small divergence ($\theta_{e^+} \simeq 3$ mrad), and
high density ($n_{e^+} \simeq 10^{14} - 10^{15}$ cm$^{-3}$) from a fully
optical setup is reported. The detected positron beam propagates with a
high-density electron beam and $\gamma$-rays of similar spectral shape and peak
energy, thus closely resembling the structure of an astrophysical leptonic jet.
It is envisaged that this experimental evidence, besides the intrinsic
relevance to laser-driven particle acceleration, may open the pathway for the
small-scale study of astrophysical leptonic jets in the laboratory.


title:
Survey data and Bayesian analysis: a cost-efficient way to estimate
  customer equity

abstract:
  We present a Bayesian framework for estimating the customer lifetime value
(CLV) and the customer equity (CE) based on the purchasing behavior deducible
from the market surveys on customer purchasing behavior. The proposed framework
systematically addresses the challenges faced when the future value of
customers is estimated based on survey data. The scarcity of the survey data
and the sampling variance are countered by utilizing the prior information and
quantifying the uncertainty of the CE and CLV estimates by posterior
distributions. Furthermore, information on the purchase behavior of the
customers of competitors available in the survey data is integrated to the
framework. The introduced approach is directly applicable in the domains where
a customer relationship can be thought to be monogamous.
  As an example on the use of the framework, we analyze a consumer survey on
mobile phones carried out in Finland in February 2013. The survey data contains
consumer given information on the current and previous brand of the phone and
the times of the last two purchases.


title:
Niobium-based superconducting nano-devices fabrication using all-metal
  suspended masks

abstract:
  We report a novel method for the fabrication of superconducting nanodevices
based on niobium. The well-known difficulties of lithographic patterning of
high-quality niobium are overcome by replacing the usual organic resist mask by
a metallic one. The quality of the fabrication procedure is demonstrated by the
realization and characterization of long and narrow superconducting lines and
niobium-gold-niobium proximity SQUIDs.


title: Amplitude mediated chimera states

abstract:
  We investigate the possibility of obtaining chimera state solutions of the
non-local Complex Ginzburg-Landau Equation (NLCGLE) in the strong coupling
limit when it is important to retain amplitude variations. Our numerical
studies reveal the existence of a variety of amplitude mediated chimera states
(including stationary and non-stationary two cluster chimera states), that
display intermittent emergence and decay of amplitude dips in their phase
incoherent regions. The existence regions of the single-cluster chimera state
and both types of two cluster chimera states are mapped numerically in the
parameter space of $C_1$ and $C_2$ the linear and nonlinear dispersion
coefficients respectively of the NLCGLE. They represent a new domain of
dynamical behaviour in the well explored rich phase diagram of this system. The
amplitude mediated chimera states may find useful applications in understanding
spatio-temporal patterns found in fluid flow experiments and other strongly
coupled systems.


title: Transmission statistics and focusing in single disordered samples

abstract:
  We show in microwave experiments and random matrix calculations that in
samples with a large number of channels the statistics of transmission for
different incident channels relative to the average transmission is determined
by a single parameter, the participation number of the eigenvalues of the
transmission matrix, M. Its inverse, M-1, is equal to the variance of relative
total transmission of the sample, while the contrast in maximal focusing is
equal to M. The distribution of relative total transmission changes from
Gaussian to negative exponential over the range in which M-1 changes from 0 to
1. This provides a framework for transmission and imaging in single samples.


title:
Quantum Popov robust stability analysis of an optical cavity containing
  a saturated Kerr medium

abstract:
  This paper applies results on the robust stability of nonlinear quantum
systems to a system consisting an optical cavity containing a saturated Kerr
medium. The system is characterized by a Hamiltonian operator which contains a
non-quadratic term involving a quartic function of the annihilation and
creation operators. A saturated version of the Kerr nonlinearity leads to a
sector bounded nonlinearity which enables a quantum small gain theorem to be
applied to this system in order to analyze its stability. Also, a non-quadratic
version of a quantum Popov stability criterion is presented and applied to
analyze the stability of this system.


title: The Mathematician's Bias - and the Return to Embodied Computation

abstract:
  There are growing uncertainties surrounding the classical model of
computation established by G\"odel, Church, Kleene, Turing and others in the
1930s onwards. The mismatch between the Turing machine conception, and the
experiences of those more practically engaged in computing, has parallels with
the wider one between science and those working creatively or intuitively out
in the 'real' world. The scientific outlook is more flexible and basic than
some understand or want to admit. The science is subject to limitations which
threaten careers. We look at embodiment and disembodiment of computation as the
key to the mismatch, and find Turing had the right idea all along - amongst a
productive confusion of ideas about computation in the real and the abstract
worlds.


title: On a de Sitter-like spacetime with cylindrical symmetry

abstract:
  A curved static de Sitter-like metric is analyzed. The source of curvature is
rooted from a constant stress tensor with positive energy density and negative
pressures. All the curvature invariants are constant everywhere and the
geometry is conformally flat. The horizon surface gravity equals the parameter
$\omega$ from the metric that is also interpreted as an angular velocity. The
Tolman-Komar gravitational energy is investigated. One finds that the horizon
entropy satisfies the relation $S = A_{H}/4$, as for the black hole horizon.


title: TMD evolution of the Sivers asymmetry

abstract:
  The energy scale dependence of the Sivers asymmetry in semi-inclusive deep
inelastic scattering is studied numerically within the framework of TMD
factorization that was put forward in 2011. The comparison to previous results
in the literature shows that the treatment of next-to-leading logarithmic
effects is important for the fall-off of the Sivers asymmetry with energy in
the measurable regime. The TMD factorization based approach indicates that the
peak of the Sivers asymmetry falls off with energy scale Q to good
approximation as 1/Q^{0.7}, somewhat faster than found previously based on the
first TMD factorization expressions by Collins and Soper in 1981. It is found
that the peak of the asymmetry moves rather slowly towards higher transverse
momentum values as $Q$ increases, which may be due to the absence of
perturbative tails of the TMDs in the presented treatments. We conclude that
the behavior of the peak of the asymmetry as a function of energy {\it and}
transverse momentum allows for valuable tests of the TMD formalism and the
considered approximations. To confront the TMD approach with experiment, high
energy experimental data from an Electron-Ion Collider is required.


title: Complexity Classifications for logic-based Argumentation

abstract:
  We consider logic-based argumentation in which an argument is a pair (Fi,al),
where the support Fi is a minimal consistent set of formulae taken from a given
knowledge base (usually denoted by De) that entails the claim al (a formula).
We study the complexity of three central problems in argumentation: the
existence of a support Fi ss De, the validity of a support and the relevance
problem (given psi is there a support Fi such that psi ss Fi?). When arguments
are given in the full language of propositional logic these problems are
computationally costly tasks, the validity problem is DP-complete, the others
are SigP2-complete. We study these problems in Schaefer's famous framework
where the considered propositional formulae are in generalized conjunctive
normal form. This means that formulae are conjunctions of constraints build
upon a fixed finite set of Boolean relations Ga (the constraint language). We
show that according to the properties of this language Ga, deciding whether
there exists a support for a claim in a given knowledge base is either
polynomial, NP-complete, coNP-complete or SigP2-complete. We present a
dichotomous classification, P or DP-complete, for the verification problem and
a trichotomous classification for the relevance problem into either polynomial,
NP-complete, or SigP2-complete. These last two classifications are obtained by
means of algebraic tools.


title: Patterns to analyze requirements of a Decisional Information System

abstract:
  The domain of analysis and conception of Decisional Information System (DIS)
is, highly, applying new techniques and methods to succeed the process of the
decision and minimizing the time of conception. Our objective in this paper is
to define a group of patterns to ensure a systematic reuse of our approach to
analyse a DIS s business requirements. We seek, through this work, to guide the
discovery of an organizations business requirements, expressed as goals by
introducing the notion of context, to promote good processes design for a DIS,
to capitalize the process and models proposed in our approach and systematize
reuse steps of this approach to analyze similar projects or adapt them as
needed. The patterns are at the same time the process s patterns and product s
patterns as they capitalize models and their associated processes. These
patterns are represented according to the PSIGMA formalism.


title: Obstacles for splitting multidimensional necklaces

abstract:
  The well-known "necklace splitting theorem" of Alon asserts that every
$k$-colored necklace can be fairly split into $q$ parts using at most $t$ cuts,
provided $k(q-1)\leq t$. In a joint paper with Alon et al. we studied a kind of
opposite question. Namely, for which values of $k$ and $t$ there is a
measurable $k$-coloring of the real line such that no interval has a fair
splitting into $2$ parts with at most $t$ cuts? We proved that $k>t+2$ is a
sufficient condition (while $k>t$ is necessary). We generalize this result to
Euclidean spaces of arbitrary dimension $d$, and to arbitrary number of parts
$q$. We prove that if $k(q-1)>t+d+q-1$, then there is a measurable $k$-coloring
of $\mathbb{R}^d$ such that no axis-aligned cube has a fair $q$-splitting using
at most $t$ axis-aligned hyperplane cuts. Our bound is of the same order as a
necessary condition $k(q-1)>t$ implied by a theorem of Alon. Moreover for
$d=1,q=2$ we get exactly the result of of Alon et al. Additionally, we prove
that if a stronger inequality $k(q-1)>dt+d+q-1$ is satisfied, then there is a
measurable $k$-coloring of $\mathbb{R}^d$ with no axis-aligned cube having a
fair $q$-splitting using at most $t$ arbitrary hyperplane cuts. The proofs are
based on the topological Baire category theorem and use algebraic independence
over suitably chosen fields.


title:
Coherent acoustic phonons emission in copper driven by super-diffusive
  hot electrons

abstract:
  Ultrafast laser excited hot electrons can transport energy supersonically far
from the region where they are initially produced. We show that this ultrafast
energy transport is responsible of the emission of coherent acoustic phonons
deeply beneath the free surface of a copper metal sample. In particular we
demonstrate that enough energy carried by these hot electrons over a distance
as large as 220nm at room temperature in copper can be converted into coherent
acoustic phonons. In order to demonstrate this effect, several configurations
of time-resolved optical experiments of time of flight of coherent acoustic
phonons and of hot electrons have been performed.


title: Some sharp Wilker type inequalities and their applications

abstract:
  In this paper, we prove that for fixed $k\geq 1$, the Wilker type inequality
{equation*} \frac{2}{k+2}(\frac{\sin x}{x}) ^{kp}+\frac{k}{k+2}(\frac{% \tan
x}{x})^{p}>1 {equation*}% holds for $x\in (0,\pi /2) $ if and only if $p>0$ or
$p\leq -% \frac{\ln (k+2) -\ln 2}{k(\ln \pi -\ln 2)}$. It is reversed if and
only if $-\frac{12}{5(k+2)}\leq p<0$. Its hyperbolic version holds for $x\in
(0,\infty) $ if and only if $% p>0$ or $p\leq -\frac{12}{5(k+2)}$. And, for
fixed $k<-2$, the hyperbolic version is reversed if and only if $p<0$ or $p\geq
-\frac{12}{% 5(k+2)}$. Our results unify and generalize some known ones.


title:
Periodicity of resonant tunneling current induced by the Stark
  resonances in semiconductor nanowire

abstract:
  The modification of the electronic current resulting from Stark resonances
has been studied for the semiconductor nanowire with the double-barrier
structure. Based on the calculated current-voltage characteristics we have
shown that the resonant tunneling current is a periodic function of the width
of the spacer layer. We have also demonstrated that the simultaneous change of
the source-drain voltage and the voltage applied to the gate located near the
nanowire leads to almost periodic changes of the resonant tunneling current as
a function of the source-drain and gate voltages. The periodic properties of
the resonant tunneling current result from the formation of the Stark resonance
states. If we change the electric field acting in the nanowire, the Stark
states periodically acquire the energies from the transport window and enhance
the tunneling current in a periodic manner. We have found that the separations
between the resonant current peaks on the source-drain voltage scale can be
described by a slowly increasing linear function of the Stark state quantum
number. This allows us to identify the quantum states that are responsible for
the enhancement of the resonant tunneling. We have proposed a method of the
experimental observation of the Stark resonances in semiconductor
double-barrier heterostructures.


title: Interfacial Coupling in Multiferroic-Ferromagnet Heterostructures

abstract:
  We report local probe investigations of the magnetic interaction between
BiFeO3 films and a ferromagnetic Co0.9Fe0.1 layer. Within the constraints of
intralayer exchange coupling in the Co0.9Fe0.1, the multiferroic imprint in the
ferromagnet results in a collinear arrangement of the local magnetization and
the in-plane BiFeO3 ferroelectric polarization. The magnetic anisotropy is
uniaxial, and an in-plane effective coupling field of order 10 mT is derived.
Measurements as a function of multiferroic layer thickness show that the
influence of the multiferroic layer on the magnetic layer becomes negligible
for 3 nm thick BiFeO3 films. We ascribe this breakdown in the exchange coupling
to a weakening of the antiferromagnetic order in the ultrathin BiFeO3 film
based on our X-ray linear dichroism measurements. These observations are
consistent with an interfacial exchange coupling between the CoFe moments and a
canted antiferromagnetic moment in the BiFeO3.


title: Sur le produit tensoriel d'alg\`ebres

abstract:
  Let $\sigma:A\rightarrow B$ and $\rho:A\rightarrow C$\ be two homomorphisms
of noetherian rings such that $B\otimes_{A}C$ is a noetherian ring. we show
that if $\sigma$ is a regular (resp. complete intersection, resp. Gorenstein,
resp. Cohen-Macaulay, resp. $(S_{n}$), resp. almost Cohen-Macaulay)
homomorphism, so is $\sigma\otimes I_{C}$ and the converse is true if $\rho$ is
faithfully flat.
  We deduce the transfert of the previous properties of $B$ and $C$ for
$B\otimes_{A}C$, and then for the completed tensor product
$B\hat{\otimes}_{A}C$. If $B\otimes_{A}B$ is noetherian and $\sigma$ is flat,
we give a necessary and sufficient condition to $B\otimes_{A}B$ be a regular
ring.


title:
How to measure diffusional decoherence in multimode rubidium vapor
  memories?

abstract:
  Diffusion is the main limitation of storage time in spatially multimode
applications of warm atomic vapors. Precise knowledge of diffusional
decoherence in the system is desired for designing most of vapor memory setups.
Here we present a novel, efficient and direct method of measuring unbiased
diffusional decoherence, clearly distinguished from all other decoherence
sources. We found the normalized diffusion coefficients of rubidium atoms in
noble gases to be as follows: neon 0.20 cm$^{2}$/s, krypton 0.068 cm$^{2}$/s
and we are the first to give an experimental result for rubidium in xenon:
0.057 cm$^{2}$/s. Our method consists in creating, storing and retrieving
spatially-varying atomic coherence. Raman scattering provides a necessary
interface to the atoms that allows for probing many spatial periodicities of
atomic coherence concurrently. As opposed to previous experiments the method
can be used for any single sealed glass cell and it does not require any setup
alterations during the measurements and therefore it is robust and repeatable.


title: Multi-transmission-line-beam interactive system

abstract:
  We construct here a Lagrangian field formulation for a system consisting of
an electron beam interacting with a slow-wave structure modeled by a possibly
non-uniform multiple transmission line (MTL). In the case of a single line we
recover the linear model of a traveling wave tube (TWT) due to J.R. Pierce.
Since a properly chosen MTL can approximate a real waveguide structure with any
desired accuracy, the proposed model can be used in particular for design
optimization. Furthermore, the Lagrangian formulation provides for: (i) a clear
identification of the mathematical source of amplification, (ii) exact
expressions for the conserved energy and its flux distributions obtained from
the Noether theorem. In the case of uniform MTLs we carry out an exhaustive
analysis of eigenmodes and find sharp conditions on the parameters of the
system to provide for amplifying regimes.


title:
Differential cross sections $^4$He({$\gamma$,p})$^3$H and
  $^4$He({$\gamma$,n})$^3$He reactions in the range of the photon energies up
  to the threshold of the meson production

abstract:
  Differential cross sections two-body ($\gamma,p$) and ($\gamma,n$) reactions
of the $^4$He nucleus disintegration were measured using the bremsstrahlung
beam of photons at the KIPT linac LEA-300 at the maximum energy ${\rm
E}_{\gamma}^{max}$ = 150 MeV. The reaction products were detected in a
diffusion chamber placed in the magnetic field. The differential cross sections
were measured with a 1 MeV step up to a photon energy of 45 MeV, and with a
greater step at higher energies. The step in the measurements of the polar
angle of nucleon emission was ${10}^{\circ}$ in the c.m.s.


title: Energetic Particle Diffusion In Critically Balanced Turbulence

abstract:
  Observations and modelling suggest that the fluctuations in magnetised
plasmas exhibit scale-dependent anisotropy, with more energy in the
fluctuations perpendicular to the mean magnetic field than in the parallel
fluctuations and the anisotropy increasing at smaller scales. The
scale-dependence of the anisotropy has not been studied in full-orbit
simulations of particle transport in turbulent plasmas so far. In this paper,
we construct a model of critically balanced turbulence, as suggested by
\cite{GoSr1995}, and calculate energetic particle spatial diffusion
coefficients using full-orbit simulations. The model uses an enveloped
turbulence approach, where each 2-dimensional wave mode with wavenumber
$k_\perp$ is packed into envelopes of length $L$ following the critical balance
condition, $L\propto k_\perp^{-2/3}$, with the wave mode parameters changing
between envelopes. Using full-orbit particle simulations, we find that both the
parallel and perpendicular diffusion coefficients increase by a factor 2,
compared to previous models with scale-independent anisotropy.


title:
Study of piN->pipiN processes on polarized targets II.: The prediction
  of rho^0(770)-f_0(980) spin mixing

abstract:
  In Part I. of this work we have presented evidence that the measured relative
phases of transversity amplitudes in piN->pipiN processes differ from those
predicted by the unitary evolution law. We ascribed this difference to a
non-unitary interaction of the produced final state rho_f(S) with a universal
quantum environment in the Universe. This new kind of interaction must be a
pure dephasing interaction. If the quantum environment is to be an integral
part of the Nature then its dephasing interactions must be fully consistent
with the Standard Model. In this work we impose on the dephasing interaction
the requirements of the conservation of the identities and four-momenta of the
final state particles, Lorentz symmetry, P-parity and the conservation of total
angular momentum and isospin. From this consistency alone we find that in
piN->pipiN the dephasing interaction must be a dipion spin mixing interaction.
The theory predicts rho^0(770)-f_0(980) mixing in the S- and P-wave amplitudes
in pi(-)p->pi(-)pi(+)n. The predicted moduli and relative phases are in
agreement with experimental results. The spin mixing of S-matrix amplitudes to
form new observable amplitudes is a new phenomenon beyond the Standard Model.
It is our conjecture that the pure dephasing interaction describes the
non-standard interaction of baryonic matter with dark matter and dark energy
which we identify with the quantum environment.


title: Sparse integrative clustering of multiple omics data sets

abstract:
  High resolution microarrays and second-generation sequencing platforms are
powerful tools to investigate genome-wide alterations in DNA copy number,
methylation and gene expression associated with a disease. An integrated
genomic profiling approach measures multiple omics data types simultaneously in
the same set of biological samples. Such approach renders an integrated data
resolution that would not be available with any single data type. In this
study, we use penalized latent variable regression methods for joint modeling
of multiple omics data types to identify common latent variables that can be
used to cluster patient samples into biologically and clinically relevant
disease subtypes. We consider lasso [J. Roy. Statist. Soc. Ser. B 58 (1996)
267-288], elastic net [J. R. Stat. Soc. Ser. B Stat. Methodol. 67 (2005)
301-320] and fused lasso [J. R. Stat. Soc. Ser. B Stat. Methodol. 67 (2005)
91-108] methods to induce sparsity in the coefficient vectors, revealing
important genomic features that have significant contributions to the latent
variables. An iterative ridge regression is used to compute the sparse
coefficient vectors. In model selection, a uniform design [Monographs on
Statistics and Applied Probability (1994) Chapman & Hall] is used to seek
"experimental" points that scattered uniformly across the search domain for
efficient sampling of tuning parameter combinations. We compared our method to
sparse singular value decomposition (SVD) and penalized Gaussian mixture model
(GMM) using both real and simulated data sets. The proposed method is applied
to integrate genomic, epigenomic and transcriptomic data for subtype analysis
in breast and lung cancer data sets.


title:
Context-Independent Centrality Measures Underestimate the Vulnerability
  of Power Grids

abstract:
  Power grids vulnerability is a key issue in society. A component failure may
trigger cascades of failures across the grid and lead to a large blackout.
Complex network approaches have shown a direction to study some of the problems
faced by power grids. Within Complex Network Analysis structural
vulnerabilities of power grids have been studied mostly using purely
topological approaches, which assumes that flow of power is dictated by
shortest paths. However, this fails to capture the real flow characteristics of
power grids. We have proposed a flow redistribution mechanism that closely
mimics the flow in power grids using the PTDF. With this mechanism we enhance
existing cascading failure models to study the vulnerability of power grids.
  We apply the model to the European high-voltage grid to carry out a
comparative study for a number of centrality measures. `Centrality' gives an
indication of the criticality of network components. Our model offers a way to
find those centrality measures that give the best indication of node
vulnerability in the context of power grids, by considering not only the
network topology but also the power flowing through the network. In addition,
we use the model to determine the spare capacity that is needed to make the
grid robust to targeted attacks. We also show a brief comparison of the end
results with other power grid systems to generalise the result.


title:
Evolution of magnetic interactions in a pressure-induced Jahn-Teller
  driven magnetic dimensionality switch

abstract:
  We present the results of high-field magnetization and muon-spin relaxation
measurements on the coordination polymer CuF_2(H_2O)_2(pyrazine) in pressures
up to 22.5 kbar. We observe a transition from a quasi-two-dimensional to a
quasi-one-dimensional antiferromagnetic phase at 9.1 kbar, driven by a rotation
of the Jahn-Teller axis. Long-range antiferromagnetic ordering is seen in both
regimes, as well as a phase separation in the critical pressure region. The
magnetic dimensionality switching as pressure is increased is accompanied by a
halving of the primary magnetic exchange energy J and a fivefold decrease in
the ordering temperature T_N. J decreases gradually with pressure in the
two-dimensional phase, and then increases in the one-dimensional regime. We
relate both effects to the changes in the crystal structure with applied
pressure.


title:
A scalable computational framework for establishing long-term behavior
  of stochastic reaction networks

abstract:
  Reaction networks are systems in which the populations of a finite number of
species evolve through predefined interactions. Such networks are found as
modeling tools in many biological disciplines such as biochemistry, ecology,
epidemiology, immunology, systems biology and synthetic biology. It is now
well-established that, for small population sizes, stochastic models for
biochemical reaction networks are necessary to capture randomness in the
interactions. The tools for analyzing such models, however, still lag far
behind their deterministic counterparts. In this paper, we bridge this gap by
developing a constructive framework for examining the long-term behavior and
stability properties of the reaction dynamics in a stochastic setting. In
particular, we address the problems of determining ergodicity of the reaction
dynamics, which is analogous to having a globally attracting fixed point for
deterministic dynamics. We also examine when the statistical moments of the
underlying process remain bounded with time and when they converge to their
steady state values. The framework we develop relies on a blend of ideas from
probability theory, linear algebra and optimization theory. We demonstrate that
the stability properties of a wide class of biological networks can be assessed
from our sufficient theoretical conditions that can be recast as efficient and
scalable linear programs, well-known for their tractability. It is notably
shown that the computational complexity is often linear in the number of
species. We illustrate the validity, the efficiency and the wide applicability
of our results on several reaction networks arising in biochemistry, systems
biology, epidemiology and ecology. The biological implications of the results
as well as an example of a non-ergodic biological network are also discussed.


title:
The thermomagnetic instability in superconducting films with adjacent
  metal layer

abstract:
  Dendritic flux avalanches is a frequently encountered consequence of the
thermomagnetic instability in type-II superconducting films. The avalanches,
potentially harmful for superconductor-based devices, can be suppressed by an
adjacent normal metal layer, even when the two layers are not in thermal
contact. The suppression of the avalanches in this case is due to so-called
magnetic braking, caused by eddy currents generated in the metal layer by
propagating magnetic flux. We develop a theory of magnetic braking by analyzing
coupled electrodynamics and heat flow in a superconductor-normal metal bilayer.
The equations are solved by linearization and by numerical simulation of the
avalanche dynamics. We find that in an uncoated superconductor, even a uniform
thermomagnetic instability can develop into a dendritic flux avalanche. The
mechanism is that a small non-uniformity caused by the electromagnetic
non-locality induces a flux-flow hot spot at a random position. The hot spot
quickly develops into a finger, which at high speeds penetrates into the
superconductor, forming a branching structure. Magnetic braking slows the
avalanches, and if the normal metal conductivity is sufficiently high, it can
suppress the formation of the dendritic structure. During avalanches, the
braking by the normal metal layer prevents the temperature from exceeding the
transition temperature of the superconductor. Analytical criteria for the
instability threshold are developed using the linear stability analysis. The
criteria are found to match quantitatively the instability onsets obtained in
simulation.


title:
Statistics of sums of correlated variables described by a matrix product
  ansatz

abstract:
  We determine the asymptotic distribution of the sum of correlated variables
described by a matrix product ansatz with finite matrices, considering
variables with finite variances. In cases when the correlation length is
finite, the law of large numbers is obeyed, and the rescaled sum converges to a
Gaussian distribution. In constrast, when correlation extends over system size,
we observe either a breaking of the law of large numbers, with the onset of
giant fluctuations, or a generalization of the central limit theorem with a
family of nonstandard limit distributions. The corresponding distributions are
found as mixtures of delta functions for the generalized law of large numbers,
and as mixtures of Gaussian distributions for the generalized central limit
theorem. Connections with statistical physics models are emphasized.


title:
Is there a hot spot of sea-level rise acceleration along the
  mid-Atlantic United States? A Gaussian process decomposition of tide gauge
  records

abstract:
  To test a hypothesized faster-than-global sea-level acceleration along the
mid-Atlantic United States, I construct a Gaussian process model that
decomposes tide gauge data into short-term variability and longer-term trends,
and into globally-coherent, regionally-coherent and local components. While
tide gauge records indicate a faster-than-global increase in the rate of
mid-Atlantic U.S. sea-level rise beginning ~1975, this acceleration could
reflect either the start of a long-term trend or ocean dynamic variability. The
acceleration will need to continue for ~2 decades before the rate of increase
of the sea-level gradient between the mid-Atlantic and southeastern U.S. can be
judged as very likely unprecedented by 20th century standards. However, the
gradient is correlated with the Atlantic Multidecadal Oscillation, North
Atlantic Oscillation, and Gulf Stream North Wall indices, all of which are
currently within the range of past variability.


title:
High Order Space-Time Adaptive WENO Finite Volume Schemes for
  Non-Conservative Hyperbolic Systems

abstract:
  We present a class of high order finite volume schemes for the solution of
non-conservative hyperbolic systems that combines the one-step ADER-WENO finite
volume approach with space-time adaptive mesh refinement (AMR). The resulting
algorithm, which is particularly well suited for the treatment of material
interfaces in compressible multi-phase flows, is based on: (i) high order of
accuracy in space obtained through WENO reconstruction, (ii) a high order
one-step time discretization via a local space-time discontinuous Galerkin
predictor method, and (iii) the use of a path conservative scheme for handling
the non-conservative terms of the equations. The AMR property with time
accurate local time stepping, which has been treated according to a
'cell-by-cell' strategy, strongly relies on the high order one-step time
discretization, which naturally allows a high order accurate and consistent
computation of the jump terms at interfaces between elements using different
time steps. The new scheme has been successfully validated on some test
problems for the Baer-Nunziato model of compressible multiphase flows.


title:
Separating the Real from the Synthetic: Minutiae Histograms as
  Fingerprints of Fingerprints

abstract:
  In this study we show that by the current state-of-the-art synthetically
generated fingerprints can easily be discriminated from real fingerprints. We
propose a method based on second order extended minutiae histograms (MHs) which
can distinguish between real and synthetic prints with very high accuracy. MHs
provide a fixed-length feature vector for a fingerprint which are invariant
under rotation and translation. This 'test of realness' can be applied to
synthetic fingerprints produced by any method. In this work, tests are
conducted on the 12 publicly available databases of FVC2000, FVC2002 and
FVC2004 which are well established benchmarks for evaluating the performance of
fingerprint recognition algorithms; 3 of these 12 databases consist of
artificial fingerprints generated by the SFinGe software. Additionally, we
evaluate the discriminative performance on a database of synthetic fingerprints
generated by the software of Bicz versus real fingerprint images. We conclude
with suggestions for the improvement of synthetic fingerprint generation.


title: Calculation of proton-${}^3$He elastic scattering between 7 and 35 MeV

abstract:
  Background: Theoretical calculations of the four-particle scattering above
the four-cluster breakup threshold are technically very difficult due to
nontrivial singularities or boundary conditions. Further complications arise
when the long-range Coulomb force is present.
  Purpose: We aim at calculating proton-${}^3$He elastic scattering observables
above three- and four-cluster breakup threshold.
  Methods: We employ Alt, Grassberger, and Sandhas (AGS) equations for the
four-nucleon transition operators and solve them in the momentum-space
framework using the complex-energy method whose accuracy and practical
applicability is improved by a special integration method.
  Results: Using realistic nuclear interaction models we obtain fully converged
results for the proton-${}^3$He elastic scattering. The differential cross
section, proton and ${}^3$He analyzing powers, spin correlation and spin
transfer coefficients are calculated at proton energies ranging from 7 to 35
MeV. Effective three- and four-nucleon forces are included via the explicit
excitation of a nucleon to a $\Delta$ isobar.
  Conclusions: Realistic proton-${}^3$He scattering calculations above the
four-nucleon breakup threshold are feasible. There is quite good agreement
between the theoretical predictions and experimental data for the
proton-${}^3$He scattering in the considered energy regime. The most remarkable
disagreements are the peak of the proton analyzing power at lower energies and
the minimum of the differential cross section at higher energies. Inclusion of
the $\Delta$ isobar reduces the latter discrepancy.


title:
f(R, T, R_\mu\nu T^\mu\nu) gravity phenomenology and \Lambda CDM
  universe

abstract:
  We propose general f(R,T,R_{\mu\nu}T^{\mu\nu}) theory as generalization of
covariant Horava-like gravity with dynamical Lorentz symmetry breaking. FRLW
cosmological dynamics for several versions of such theory is considered. The
reconstruction of the above action is explicitly done, including the numerical
reconstruction for the occurrence of \Lambda CDM universe. De Sitter universe
solutions in the presence of non-constant fluid are also presented. The problem
of matter instability in f(R,T,R_{\mu\nu}T^{\mu\nu}) gravity is discussed.


title: An Adaptive Threshold in Mammalian Neocortical Evolution

abstract:
  Expansion of the neocortex is a hallmark of human evolution. However, it
remains an open question what adaptive mechanisms facilitated its expansion.
Here we show, using gyrencephaly index (GI) and other physiological and
life-history data for 102 mammalian species, that gyrencephaly is an ancestral
mammalian trait. We provide evidence that the evolution of a highly folded
neocortex, as observed in humans, requires the traversal of a threshold of 10^9
neurons, and that species above and below the threshold exhibit a bimodal
distribution of physiological and life-history traits, establishing two
phenotypic groups. We identify, using discrete mathematical models,
proliferative divisions of progenitors in the basal compartment of the
developing neocortex as evolutionarily necessary and sufficient for generating
a fourteen-fold increase in daily prenatal neuron production and thus traversal
of the neuronal threshold. We demonstrate that length of neurogenic period,
rather than any novel progenitor-type, is sufficient to distinguish cortical
neuron number between species within the same phenotypic group.


title:
A note on extremal states of composite quantum systems with fixed
  marginals

abstract:
  An extremal element of the convex set of composite quantum states in
$M_2\otimes M_3$, whose marginals are all normalised identities has been
constructed. It is found to be a mixed state and is entangled as well.

categories: quant-ph math-ph math.FA math.MP math.OA


title:
Limits on compact halo objects as dark matter from gravitational
  microlensing

abstract:
  Microlensing started with the seminal paper by Paczy\'nski in 1986, first
with observations towards the Large Magellanic Cloud and the galactic bulge.
Since then many other targets have been observed and new applications have been
found. In particular, it turned out to be a powerful method to detect planets
in our galaxy and even in the nearby M31. Here, we will present some results
obtained so far by microlensing without being, however, exhaustive.


title:
Effects of Electron-Electron Interactions on Electronic Raman Scattering
  of Graphite in High Magnetic Fields

abstract:
  We report the observation of strongly temperature-dependent, asymmetric
spectral lines in electronic Raman scattering spectra of graphite in a high
magnetic field up to 45 T applied along the c-axis. The magnetic field
quantizes the in-plane motion, while the out-of-plane motion remains free,
effectively reducing the system dimension from three to one. Optically created
electron-hole pairs interact with, or shake up, the one-dimensional Fermi sea
in the lowest Landau subbands. Based on the Tomonaga-Luttinger liquid theory,
we show that interaction effects modify the van Hove singularity to the form
$(\omega-\Delta)^{2\alpha-1/2}$ at zero temperature. At finite temperature, we
predict a thermal broadening factor that increases linearly with the
temperature. Our model reproduces the observed temperature-dependent
line-shape, determining $\alpha$ to be $\sim$0.05 at 40 T.


title:
The Worst Case ISI channels and the Uniqueness of the Corresponding
  Minimum Eigenvalue

abstract:
  Intersymbol interference (ISI) is a major cause of degradation in the
receiver performance of high-speed data communications systems. This arises
mainly due to limited bandwidth available. The minimum Euclidean distance
between any two symbol sequences is an important parameter in this case at
moderate to high signal to noise ratios. It is proven here that as ISI
increases the minimum distance strictly decreases when the worst case scenario
is considered. From this it follows that the minimum eigenvalue of the worst
case ISI channel of a given length is unique.


title:
Analytic Expressions for Stochastic Distances Between Relaxed Complex
  Wishart Distributions

abstract:
  The scaled complex Wishart distribution is a widely used model for multilook
full polarimetric SAR data whose adequacy has been attested in the literature.
Classification, segmentation, and image analysis techniques which depend on
this model have been devised, and many of them employ some type of
dissimilarity measure. In this paper we derive analytic expressions for four
stochastic distances between relaxed scaled complex Wishart distributions in
their most general form and in important particular cases. Using these
distances, inequalities are obtained which lead to new ways of deriving the
Bartlett and revised Wishart distances. The expressiveness of the four analytic
distances is assessed with respect to the variation of parameters. Such
distances are then used for deriving new tests statistics, which are proved to
have asymptotic chi-square distribution. Adopting the test size as a comparison
criterion, a sensitivity study is performed by means of Monte Carlo experiments
suggesting that the Bhattacharyya statistic outperforms all the others. The
power of the tests is also assessed. Applications to actual data illustrate the
discrimination and homogeneity identification capabilities of these distances.


title: Universality in symbolic dynamics constrained by Medvedev degrees

abstract:
  We define a weak notion of universality in symbolic dynamics and, by
generalizing a proof of Mike Hochman, we prove that this yields necessary
conditions on the forbidden patterns defining a universal subshift: These
forbidden patterns are necessarily in a Medvedev degree greater or equal than
the degree of the set of subshifts for which it is universal.
  We also show that this necessary condition is optimal by giving constructions
of universal subshifts in the same Medvedev degree as the subshifts they
simulate and prove that this universality can be achieved by the sofic
projective subdynamics of such a subshift as soon as the necessary conditions
are verified.
  This could be summarized as: There are obstructions for the existence of
universal subshifts due to the theory of computability and they are the only
ones.


title:
Robustness of the Berezinskii-Kosterlitz-Thouless Transition in
  Ultrathin NbN Films near the Superconductor-Insulator Transition

abstract:
  Occurrence of the Berezinskii-Kosterlitz-Thouless (BKT) transition is
investigated by superfluid density measurements for two-dimensional (2D)
disordered NbN films with disorder level very close to a
superconductor-insulator transition (SIT). Our data show a robust BKT
transition even near this 2D disorder-tuned quantum critical point (QCP). This
observation is in direct contrast with previous data on deeply underdoped
quasi-2D cuprates near the SIT. As our NbN films approach the QCP, the
vortex-core energy, an important energy scale in the BKT transition, scales
with the superconducting gap, not with the superfluid density, as expected
within the standard 2D-XY model description of BKT physics.


title:
Measurement of the isotopic composition of hydrogen and helium nuclei in
  cosmic rays with the PAMELA experiment

abstract:
  The satellite-borne experiment PAMELA has been used to make new measurements
of cosmic ray H and He isotopes. The isotopic composition was measured between
100 and 600 MeV/n for hydrogen and between 100 and 900 MeV/n for helium
isotopes over the 23rd solar minimum from July 2006 to December 2007. The
energy spectrum of these components carries fundamental information regarding
the propagation of cosmic rays in the galaxy which are competitive with those
obtained from other secondary to primary measurements such as B/C.


title: Strongly representable atom structures

abstract:
  Using constructions of Hirsch and Hodkinson, we show that the class of
strongly atom structures for various cylindric-like algebras is not elementary.
This applies to diagonal free reducts and polyadic algebras with and without
equality. This follows from the simple observation, that the cylindric atom
structures of dimension n, constructed by Hirsch and Hodkinson, are built from
algebras that can be easily expanded to polyadic equality algebras, and that
such expansions are generated by elements whose dimension sets <n.


title:
Measurement of the ZZ production cross section and search for the
  standard model Higgs boson in the four lepton final state in ppbar collisions

abstract:
  We present a measurement of Z boson pair production in ppbar collisions at
1.96 TeV with 9.6 fb-1 to 9.8fb-1 of D0 data. We examine the final states with
four electrons, two electrons plus two muons, and four muons. Based on selected
data, the measured cross section in the mass region M(Z/gamma*) > 30 GeV is
sigma(ppbar to Z/gamma* Z/gamma*)= 1.26 ^{+0.44}_{-0.36} (stat)
^{+0.17}_{-0.15} (syst) +/- 0.08 (lumi) pb; after correcting for the expected
ratio of sigma(ppbar to Z/gamma* Z/gamma*) to sigma(ppbar to ZZ), we derive a
cross section for ppbar to ZZ production of 1.05 ^{+0.37}_{-0.30} (stat)
^{+0.14}_{-0.12} (syst) +/- 0.06 (lumi) pb. This result is combined with a
previous result from the ZZ to two charged leptons plus two neutrinos channel
resulting in a combined ppbar to ZZ cross section measurement of 1.32
^{+0.29}_{-0.25} (stat) +/- 0.12 (syst) +/- 0.04 (lumi)} pb. These measurements
are consistent with the standard model expectation of 1.43 \pm 0.10 pb. We
extend this analysis to search for the standard model (SM) Higgs boson between
115 and 200 GeV. At a Higgs boson mass of 125 GeV, we expect to set a limit of
43 times the SM expectation at 95% C.L., and set a limit of 42 times the SM
expectation at 95% C.L.


title: Waveless ships in the low speed limit: Results for multi-cornered hulls

abstract:
  In the low-speed limit, a blunt ship modeled as two-dimensional semi-infinite
body with a single corner can never be made waveless. This was the conclusion
of the previous part of our work in Trinh et al. (2011), which focused on the
Dagan & Tulin (1972) model of ship waves in the low speed limit. In this
accompanying paper, we continue our investigations with the study of more
general, piecewise-linear, or multi-cornered ships. The low-speed or low-Froude
limit, coupled with techniques in exponential asymptotics allows us to derive
explicit formulae relating the geometry of the hull to the form of the waves.
Configurations with closely spaced corners present a non-trivial extension of
the theory, and we present the general methodology for their study. Lastly,
numerical computations of the nonlinear ship-wave problem are presented in
order to confirm the analytical predictions.


title: A Stochastic Gronwall Lemma

abstract:
  We prove a stochastic Gronwall lemma of the following type: if $Z$ is an
adapted nonnegative continuous process which satisfies a linear integral
inequality with an added continuous local martingale $M$ and a process $H$ on
the right hand side, then for any $p \in (0,1)$ the $p$-th moment of the
supremum of $Z$ is bounded by a constant $\kappa_p$ (which does not depend on
$M$) times the $p$-th moment of the supremum of $H$. Our main tool is a
martingale inequality which is due to D. Burkholder. We provide an alternative
simple proof of the martingale inequality which provides an explicit numerical
value for the constant $c_p$ appearing in the inequality which is at most four
times as large as the optimal constant.


title: Connectedness of the set of central Lyapunov exponents

abstract:
  We show that there is a residual subset $\mathcal{R}$ of $Diff^1(M)$ such
that for any $f\in\mathcal{R}$ and any partially hyperbolic homoclinic class
$H(p,f)$ with one dimensional center direction, the set of central Lyapunov
exponents associated with the ergodic with either full support or positive
entropy is an interval.


title: Null Controllability of the 2D Heat Equation Using Flatness

abstract:
  We derive in a direct and rather straightforward way the null controllability
of a 2-D heat equation with boundary control. We use the so-called flatness
approach, which consists in parameterizing the solution and the control by the
derivatives of a "flat output". This provides an explicit control law achieving
the exact steering to zero. Numerical experiments demonstrate the relevance of
the approach.


title: On The Number of Edge-3-Colourings of A Snipped Snark

abstract:
  For a given snark G and edge e of G, we can form a cubic graph G_e using an
operation we call "edge subtraction". The number of 3-edge-colourings of G_e is
18 * \psi(G,e) for some nonnegative integer \psi(G,e). Given snarks G_1 and
G_2, we can form a new snark G using techniques given by Isaacs and Kochol. In
this note we give relationships between \psi(G_1,e_1), \psi(G_2,e_2), and
\psi(G,e) for particular edges e_1, e_2, and e, in G_1, G_2, and G
(respectively). As a consequence, if g,h,i,j,k,l are each a nonnegative
integer, then there exists a cyclically 5-edge-connected snark G with an edge e
such that \psi(G,e)=5^g * 7^h, and a cyclically 4-edge-connected snark G_0 with
an edge e_0 such that \psi(G_0,e_0)=2^i * 3^j * 5^k * 7^l.


title:
The simplest mixed finite element method for linear elasticity in the
  symmetric formulation on $n$-rectangular grids

abstract:
  A family of mixed finite elements is proposed for solving the first order
system of linear elasticity equations in any space dimension, where the stress
field is approximated by symmetric finite element tensors.
  This family of elements has a perfect matching between the stress components
and the displacement.
  The discrete spaces for the normal stress $\sigma_{ii}$, the shear stress
$\sigma_{ij}$ and the displacement $u_i$ are
  $\operatorname{span}\{1,x_i\}$, $\operatorname{span}\{1,x_i,x_j\}$ and
$\operatorname{span}\{1\}$, respectively, on rectangular grids.
  In particular, the definition remains the same for all space dimensions. As a
result of these choices, the theoretical analysis is independent of the spatial
dimension as well. In 1D, this element is nothing else but the 1D
Raviart-Thomas element, which is the only conforming element in this family. In
2D and higher dimensions, they are new elements but of the minimal degrees of
freedom. The total degrees of freedom per element is 2 plus 1 in 1D, 7 plus 2
in 2D, and 15 plus 3 in 3D.
  The previous record of the least degrees of freedom is, 13 plus 4 in 2D, and
54 plus 12 in 3D, on the rectangular grid.
  These elements are the simplest element for any space dimension.
  The well-posedness condition and the optimal a priori error estimate of the
family of finite elements are proved for both pure displacement and traction
problems. Numerical tests in 2D and 3D are presented to show a superiority of
the new element over others, as a superconvergence is surprisingly exhibited.


title:
A note on the complexity of comparing succinctly represented integers,
  with an application to maximum probability parsing

abstract:
  The following two decision problems capture the complexity of comparing
integers or rationals that are succinctly represented in
product-of-exponentials notation, or equivalently, via arithmetic circuits
using only multiplication and division gates, and integer inputs:
  Input instance: four lists of positive integers: a_1, ...., a_n ; b_1,....,
b_n ; c_1,....,c_m ; d_1, ...., d_m ; where each of the integers is represented
in binary.
  Problem 1 (equality testing): Decide whether a_1^{b_1} a_2^{b_2} ....
a_n^{b_n} = c_1^{d_1} c_2^{d_2} .... c_m^{d_m} .
  Problem 2 (inequality testing): Decide whether a_1^{b_1} a_2^{b_2} ...
a_n^{b_n} >= c_1^{d_1} c_2^{d_2} .... c_m^{d_m} .
  Problem 1 is easily decidable in polynomial time using a simple iterative
algorithm. Problem 2 is much harder. We observe that the complexity of Problem
2 is intimately connected to deep conjectures and results in number theory. In
particular, if a refined form of the ABC conjecture formulated by Baker in 1998
holds, or if the older Lang-Waldschmidt conjecture (formulated in 1978) on
linear forms in logarithms holds, then Problem 2 is decidable in P-time (in the
standard Turing model of computation). Moreover, it follows from the best
available quantitative bounds on linear forms in logarithms, e.g., by Baker and
W\"{u}stholz (1993) or Matveev (2000), that if m and n are fixed universal
constants then Problem 2 is decidable in P-time (without relying on any
conjectures). This latter fact was observed earlier by Shub (1993).
  We describe one application: P-time maximum probability parsing for arbitrary
stochastic context-free grammars (where \epsilon-rules are allowed).