title:
Magnetic field amplification by the small-scale dynamo in the early
  Universe

abstract:
  In this paper we show that the Universe is already strongly magnetized at
very early epochs during cosmic evolution. Our calculations are based on the
efficient amplification of weak magnetic seed fields, which are unavoidably
present in the early Universe, by the turbulent small-scale dynamo. We identify
two mechanisms for the generation of turbulence in the radiation dominated
epoch where velocity fluctuations are produced by the primordial density
perturbation and by possible first-order phase transitions at the electroweak
or QCD scales. We show that all the necessities for the small-scale dynamo to
work are fulfilled. Hence, this mechanism, operating due to primordial density
perturbations, guarantees fields with comoving field strength
$B_0\sim10^{-6}\varepsilon^{1/2}$ nG on scales up to $\lambda_c\sim0.1$ pc,
where $\varepsilon$ is the saturation efficiency. The amplification of magnetic
seed fields could be even larger if there are first-order phase transitions in
the early Universe. Where, on scales up to $\lambda_c\sim100$ pc, the comoving
field strength due to this mechanism will be $B_0\sim10^{-3}\varepsilon^{1/2}$
nG at the present time. Such fields, albeit on small scales, can play an
important role in structure formation and could provide an explanation to the
apparently observed magnetic fields in the voids of the large-scale structure.


title:
Focusing on best proximity points of generalized versions of cyclic
  impulsive self-mappings

abstract:
  This paper studies the properties of convergence of distances between points
and the existence and uniqueness of best proximity and fixed points of the
so-called semi-cyclic impulsive self-mappings on the union of a number of
nonempty subsets in metric spaces. The concept of semi-cyclic self- mappings
generalizes the well-known of cyclic ones in the sense that the iterated
sequences built through such mappings are allowed to have images located in the
same subset as its pre-image. The self-mappings under study may be impulsive
since eventually being composite mappings involving two self-mappings, one of
them being eventually discontinuous so that the formalism can potentially be
applied to the study of stability of a class of impulsive differential
equations and their discrete counterparts


title:
Effects of structural and chemical disorders on the visible/UV spectra
  of carbonaceous interstellar grains

abstract:
  The recent spectacular progress in the experimental and theoretical
understanding of graphene, the basic constituent of graphite, is applied here
to compute, from first principles, the UV extinction of nano-particles made of
stacks of graphene layers. The theory also covers cases where graphene is
affected by structural, chemical or orientation disorder, each disorder type
being quantitatively defined by a single parameter. The extinction bumps
carried by such model materials are found to have positions and widths falling
in the same range as the known astronomical 2175 \AA features: as the disorder
parameter increases, the bump width increases from 0.85 to 2.5 $\mu$m$^{-1}$,
while its peak position shifts from 4.65 to 4.75 $\mu$m$^{-1}$. Moderate
degrees of disorder are enough to cover the range of widths of the vast
majority of observed bumps (0.75 to 1.3 $\mu$m$^{-1}$). Higher degrees account
for outliers, also observed in the sky.
  The introduction of structural or chemical disorder amounts to changing the
initial $sp^{2}$ bondings into $sp^{3}$ or $sp^{1}$, so the optical properties
of the model material become similar to those of the more or less amorphous
carbon-rich materials studied in the laboratory: a-C, a-C:H, HAC, ACH, coals
etc. The present treatment thus bridges gaps between physically different model
materials.


title:
Controlling Fusion of Majorana Fermions in one-dimensional systems by
  Zeeman Field

abstract:
  We propose to realize Majorana fermions (MFs) on an edge of a two-dimensional
topological insulator in the proximity with s-wave superconductors and in the
presence of transverse exchange field h. It is shown that there appear a pair
of MFs localized at two junctions and that a reverse in direction of h can lead
to permutation of two MFs. With decreasing h, the MF states can either be fused
or form one Dirac fermion on the {\pi}-junctions, exhibiting a topological
phase transition. This characteristic can be used to detect physical states of
MFs when they are transformed into Dirac fermions localized on the
{\pi}-junction. A condition of decoupling two MFs is also given.


title: The vortex equation on affine manifolds

abstract:
  Let M be a compact connected special affine manifold equipped with an affine
Gauduchon metric. We show that a pair (E, \phi), consisting of a flat vector
bundle E over M and a flat nonzero section \phi\ of E, admits a solution to the
vortex equation if and only if it is polystable. To prove this, we adapt the
dimensional reduction techniques for holomorphic pairs on K\"ahler manifolds to
the situation of flat pairs on affine manifolds.


title:
Magnetic structure of the frustrated S=1/2 chain magnet LiCu2O2 doped
  with nonmagnetic Zn

abstract:
  We present the results of magnetization, ESR and NMR measurements on single
crystal samples of the frustrated S=1/2 chain cuprate LiCu2O2 doped with
nonmagnetic Zn^2+. As shown by the x-ray techniques the crystals of
Li(Cu{1-x}Zn{x})2O2 with x<0.12 are single-phase, whereas for higher Zn
concentrations the samples were polyphase. ESR spectra for all monophase
samples (0<= x<0.12) can be explained within the model of a planar spin
structure with a uniaxial type anisotropy. The NMR spectra of the highly doped
single crystal sample Li(Cu0.9Zn0.1)2O2 can be described in the frame of a
planar spin glass like magnetic structure with short range spiral correlations
in the crystal (ab)-planes with strongest exchange bonds. The value of magnetic
moments of Cu^2+ ions in this structure is close to value obtained for undoped
crystals: (0.8 +- 0.1) mu_B.


title:
The Digital discrimination of neutron and {\gamma} ray using organic
  scintillation detector based on wavelet transform modulus maximum

abstract:
  A novel algorithm for the discrimination of neutron and {\gamma}-ray with
wavelet transform modulus maximum (WTMM) in an organic scintillation has been
investigated. Voltage pulses arising from a BC501A organic liquid scintillation
detector in a mixed radiation field have been recorded with a fast digital
sampling oscilloscope. The performances of most pulse shape discrimination
methods in scintillation detection systems using time-domain features of the
pulses are affected intensively by noise. However, the WTMM method using
frequency-domain features exhibits a strong insensitivity to noise and can be
used to discriminate neutron and {\gamma}-ray events based on their different
asymptotic decay trend between the positive modulus maximum curve and the
negative modulus maximum curve in the scale-space plane. This technique has
been verified by the corresponding mixed-field data assessed by the
time-of-flight (TOF) method and the frequency gradient analysis (FGA) method.
It is shown that the characterization of neutron and gamma achieved by the
discrimination method based on WTMM is consistent with that afforded by TOF and
better than FGA. Moreover, because the WTMM method is it self presented to
eliminate the noise, there is no need to make any pretreatment for the pulses.


title: Enriching the hot circumgalactic medium

abstract:
  Models of galaxy formation in a CDM universe predict that massive galaxies
are surrounded by a hot, quasi-hydrostatic circumgalactic corona of slowly
cooling gas, predominantly accreted from the IGM. This prediction is borne out
by the cosmological hydrodynamical simulations of Crain et al., which reproduce
scaling relations between the X-ray and optical properties of nearby disc
galaxies. Such coronae are metal poor, but observations of the X-ray emitting
circumgalactic medium (CGM) of local galaxies typically indicate enrichment to
near-solar iron abundance, potentially signalling a shortcoming in galaxy
formation models. We show here that, while the hot CGM of galaxies formed in
the simulations is metal poor in a mass-weighted sense, its X-ray
luminosity-weighted metallicity is often close to solar. This bias arises
because the soft X-ray emissivity of a typical 0.1 keV corona is dominated by
collisionally-excited metal ions that are synthesised in stars and recycled
into the hot CGM. We find that these metals are ejected primarily by stars that
form in-situ to the main progenitor of the galaxy, rather than in satellites or
external galaxies. The enrichment of the hot CGM therefore proceeds in an
inside-out fashion throughout the assembly of the galaxy: metals are
transported from the central galaxy by SNe-driven winds and convection over
several gigayears, establishing a strong negative radial metallicity gradient.
Whilst metal ions synthesised by stars are necessary to produce the X-ray
emissivity that enables the hot CGM of isolated galaxies to be detected, the
electrons that collisionally excite them are equally important. Since our
simulations indicate that the electron density of hot coronae is dominated by
the metal-poor gas accreted from the IGM, we infer that the hot CGM observed
via X-ray emission is the outcome of both hierarchical accretion and stellar
recycling.


title: On Synchronization of Interdependent Networks

abstract:
  It is well-known that the synchronization of diffusively-coupled systems on
networks strongly depends on the network topology. In particular, the so-called
algebraic connectivity $\mu_{N-1}$, or the smallest non-zero eigenvalue of the
discrete Laplacian operator plays a crucial role on synchronization, graph
partitioning, and network robustness. In our study, synchronization is placed
in the general context of networks-of-networks, where single network models are
replaced by a more realistic hierarchy of interdependent networks. The present
work shows, analytically and numerically, how the algebraic connectivity
experiences sharp transitions after the addition of sufficient links among
interdependent networks.


title:
Discovery of supernova remnants in the Sino-German 6cm polarization
  survey of the Galactic plane

abstract:
  The Sino-German 6cm polarization survey has mapped in total intensity and
polarization intensity over an area of approximately 2200 square degrees in the
Galactic disk. This survey provides an opportunity to search for Galactic
supernova remnants (SNRs) that were previously unknown. We discovered the new
SNRs G178.2-4.2 and G25.1-2.3 which have non-thermal spectra, using the 6cm
data together with the observations with the Effelsberg telescope at 11 cm and
21 cm. Both G178.2-4.2 and G25.1-2.3 are faint and have an apparent diameter
greater than 1deg. G178.2-4.2 shows a polarized shell. HI data suggest that
G25.1-2.3 might have a distance of about 3 kpc. The 6cm survey data were also
very important to identify two other new SNRs, G152.4-2.1 and G190.9-2.2.


title:
Formation of relativistic non-viscous fluid in central collisions of
  protons with energy 0.8 TeV with photoemulsion nuclei

abstract:
  By the methods of mathematical statistics we test a qualitative prediction of
the old theory of relativistic hydrodynamics non-viscous liquid which can be
used as a part of the process of hadronization within the modern hydrodynamical
approach for the description of the quark-gluon plasma. Experimental data on
the interaction of protons with the energies of 0.8 TeV with emulsion nuclei
are used. Results do not contradict the formation of relativistic ideal
non-viscous liquid in rare central collisions.


title: Twists and resonance of L-functions, I

abstract:
  We obtain the basic analytic properties, i.e. meromorphic continuation, polar
structure and bounds for the order of growth, of all the nonlinear twists with
exponents $\leq 1/d$ of the L-functions of any degree $d \geq 1$ in the
extended Selberg class. In particular, this solves the resonance problem in all
such cases.


title: Functional integral approach to semi-relativistic Pauli-Fierz models

abstract:
  By means of functional integrations spectral properties of semi-relativistic
Pauli-Fierz Hamiltonians in quantum electrodynamics is considered. Two
self-adjoint extensions of a semi-relativistic Pauli-Fierz Hamiltonian are
defined. An essential self-adjointness, a spatial decay of bound states, a
Gaussian domination of the ground state and the existence of a measure
associated with the ground state are shown.


title: The Early History of the Aharonov-Bohm Effect

abstract:
  This paper traces the early history of the Aharonov-Bohm effect. It appears
to have been `discovered' at least three times to my knowledge before the
defining paper of Aharonov and Bohm appeared in 1959. The first hint of the
effect appears in Germany in 1939, immediately disappearing from sight in those
troubled times. It reappeared in a paper in 1949, ten years before the defining
paper appeared. Here I report the background to the early evolution of this
effect, presenting first hand unpublished accounts reported to me by colleagues
at Birkbeck College in the University of London.


title: Toroidal domain walls as Hopfions

abstract:
  We construct stable domain walls in a shape of a torus in the Faddeev-Skyrme
model with a quadratic potential term admitting two discrete vacua. The phase
modulus of the domain wall is twisted P and Q times along the toroidal and
poloidal cycles of the torus, respectively, where Q represents the constituent
lump charge. We find that these solutions carry the Hopf charge PQ and can be
regarded as Hopfions. The toroidal domain walls are characterized by the two
topological charges (P,Q), unlike the conventional Hopfions characterized by
only the Hopf charge. We explicitly construct stable solutions of the toroidal
domain walls with P, Q = 1,2,3, yielding the Hopf charges 1,2,3,4,6,9.


title: Computing Enclosures of Overdetermined Interval Linear Systems

abstract:
  This work considers special types of interval linear systems - overdetermined
systems. Simply said these systems have more equations than variables. The
solution set of an interval linear system is a collection of all solutions of
all instances of an interval system. By the instance we mean a point real
system that emerges when we independently choose a real number from each
interval coefficient of the interval system. Enclosing the solution set of
these systems is in some ways more difficult than for square systems. The main
goal of this work is to present various methods for solving overdetermined
interval linear systems. We would like to present them in an understandable way
even for nonspecialists in a field of linear systems. The second goal is a
numerical comparison of all the methods on random interval linear systems
regarding widths of enclosures, computation times and other special properties
of methods.


title:
Measurement of the inclusive jet cross section in pp collisions at
  sqrt(s)=2.76 TeV and comparison to the inclusive jet cross section at
  sqrt(s)=7 TeV using the ATLAS detector

abstract:
  The inclusive jet cross-section has been measured in proton-proton collisions
at sqrt(s)=2.76 TeV in a dataset corresponding to an integrated luminosity of
0.20pb-1 collected with the ATLAS detector at the Large Hadron Collider in
2011. Jets are identified using the anti-kt algorithm with two radius
parameters of 0.4 and 0.6. The inclusive jet double-differential cross-section
is presented as a function of the jet transverse momentum pT and jet rapidity
y, covering a range of 20 <= pT < 430 GeV and |y| < 4.4. The ratio of the
cross-section to the inclusive jet cross-section measurement at sqrt(s)=7 TeV,
published by the ATLAS Collaboration, is calculated as a function of both
transverse momentum and the dimensionless quantity xT = 2 pT / sqrt(s), in bins
of jet rapidity. The systematic uncertainties on the ratios are significantly
reduced due to the cancellation of correlated uncertainties in the two
measurements. Results are compared to the prediction from next-to-leading order
perturbative QCD calculations corrected for non-perturbative effects, and
next-to-leading order Monte Carlo simulation. Furthermore, the ATLAS jet
cross-section measurements at sqrt(s)=2.76 TeV and sqrt(s)=7 TeV are analysed
within a framework of next-to-leading order perturbative QCD calculations to
determine parton distribution functions of the proton, taking into account the
correlations between the measurements.


title:
Activation measurement of the 3He(a,g)7Be reaction cross section at high
  energies

abstract:
  The astrophysically important 3He(a,g)7Be reaction was studied at high
energies where the available experimental data are in contradiction. A thin
window 3He gas cell was used and the cross section was measured with the
activation method. The obtained cross sections at energies between Ec.m. = 1.5
and 2.5 MeV are compared with the available data and theoretical calculations.
The present results support the validity of the high energy cross section
energy dependence observed by recent experiments.


title:
Precision measurement of the $B^{0}_{s}$-$\bar{B}^{0}_{s}$ oscillation
  frequency with the decay $B^{0}_{s}\rightarrowD^{-}_{s}\pi^{+}$

abstract:
  A key ingredient to searches for physics beyond the Standard Model in
$B^{0}_{s}$ mixing phenomena is the measurement of the
$B^{0}_{s}$-$\bar{B}^{0}_{s}$ oscillation frequency, which is equivalent to the
mass difference $\Delta m_{s}$ of the $B^{0}_{s}$ mass eigenstates. Using the
world's largest $B^{0}_{s}$ meson sample accumulated in a dataset,
corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected by the
LHCb experiment at the CERN LHC in 2011, a measurement of $\Delta m_{s}$ is
presented. A total of about 34,000 $B^{0}_{s}\rightarrowD^{-}_{s}\pi^{+}$
signal decays are reconstructed, with an average decay time resolution of 44
fs. The oscillation frequency is measured to be \mbox{$\Delta m_{s}$ = 17.768
$\pm$ 0.023 (stat) $\pm$ 0.006 (syst) ps$^{-1}$}, which is the most precise
measurement to date.


title: Consensus time and conformity in the adaptive voter model

abstract:
  The adaptive voter model is a paradigmatic model in the study of opinion
formation. Here we propose an extension for this model, in which conflicts are
resolved by obtaining another opinion, and analytically study the time required
for consensus to emerge. Our results shed light on the rich phenomenology of
both the original and extended adaptive voter models, including a dynamical
phase transition in the scaling behavior of the mean time to consensus.

categories: physics.soc-ph cond-mat.dis-nn math-ph math.MP


title:
Adaptive refinement and selection process through defect localization
  for reconstructing an inhomogeneous refraction index

abstract:
  We consider the iterative reconstruction of both the internal geometry and
the values of an inhomogeneous acoustic refraction index through a piecewise
constant approximation. In this context, we propose two enhancements intended
to reduce the number of parameters to reconstruct, while preserving accuracy.
This is achieved through the use of geometrical informations obtained from a
previously developed defect localization method. The first enhancement consists
in a preliminary selection of relevant parameters, while the second one is an
adaptive refinement to enhance precision with a low number of parameters. Each
of them is numerically illustrated.


title: Ac-magnetic susceptibility in the peak-effect region of Nb$_3$Sn

abstract:
  We performed a systematic study of the ac magnetic-susceptibility on a Nb3Sn
single crystal which displays a strong peak effect near the upper critical
field Hc2. In external magnetic fields above 3 T, the peak effect manifests
itself in a single, distinct peak in the real part of the ac susceptibility as
a function of temperature T, the size of which continuously increases with
increasing magnetic field H. In the imaginary part of the ac susceptibility, on
the other hand, a single peak initially grows with increasing H up to a
well-defined value, and then splits into two sharp peaks which separate when H
is further increased. We explain this surprising behavior by a flux-creep model
and taking into account the enhancement of the critical-current density in the
peak-effect region near Tc in which Bean's critical-state model seems to apply.
Outside this region, the crystal is clearly in a flux-creep regime with finite
creep exponent n.


title: Fuzzy Logic and Quantum Measurement Formulation

abstract:
  The Von Neumann quantum measurement theory and Zurek reformulation are based
on an assumption that the quantum system, apparatus and environment obey the
quantum mechanics rules. According to the Zurek theory the observers typically
interact with their surrounding environments. In this article, we give a more
realistic image of the quantum measurement theory; we have proposed a
correction to Zurek quantum measurement theory based on the fuzzy logic and
fuzzy set theory.


title: Complementary cosmological tests of RSII brane models

abstract:
  In this paper we explore observational bounds on flat and non-flat
cosmological models in Type II Randall-Sundrum (RSII) branes. In a first
analysis, we consider current measurements of the expansion rate H(z) (with two
priors on the local Hubble parameter) and 288 Type Ia supernovae from the Sloan
Digital Sky Survey (within the framework of the mlcs2k2 light-curve fitting
method). We find that the joint analysis involving these data is an interesting
tool to impose limits on the brane tension density parameter (Omega_{lambda})
and that the spatial curvature has a negligible influence on Omega_{lambda}
estimates. In order to obtain stronger bounds for the contribution of the
$\Omega_{\lambda}$ we also add in our analysis the baryon oscillation peak
(BAO) and cosmic microwave background radiation (CMB) observations by using the
so-called CMB/BAO ratio. From this analysis we find that the Omega_{lambda}
contribution is less than 4.10^{-5} (1sigma).


title: Odd-parity dynamically generated baryon resonances with beauty flavor

abstract:
  We study baryon resonances with heavy flavor in a molecular approach, thus as
dynamically generated by baryon-meson scattering. This is accomplished by using
a unitary coupled-channel model taking, as bare interaction, the extension of
the Weinberg-Tomozawa SU(3) Lagrangian. A special attention is payed to the
inclusion of heavy-quark spin symmetry and to the study of the generated baryon
resonances that complete the heavy-quark spin multiplets. Our model reproduces
the \Lambda_b(5912) and \Lambda_b(5920) baryons, which were recently observed
by the LHCb collaboration. According to our analysis, these two states are
heavy-quark spin symmetric partners. We also make predictions for few \Xi_b
baryon resonances, which belong to the same SU(3)xHQSS multiplets as the
\Lambda_b particles.


title:
Local tests for identifying anisotropic diffusion areas in human brain
  with DTI

abstract:
  Diffusion tensor imaging (DTI) plays a key role in analyzing the physical
structures of biological tissues, particularly in reconstructing fiber tracts
of the human brain in vivo. On the one hand, eigenvalues of diffusion tensors
(DTs) estimated from diffusion weighted imaging (DWI) data usually contain
systematic bias, which subsequently biases the diffusivity measurements
popularly adopted in fiber tracking algorithms. On the other hand, correctly
accounting for the spatial information is important in the construction of
these diffusivity measurements since the fiber tracts are typically spatially
structured. This paper aims to establish test-based approaches to identify
anisotropic water diffusion areas in the human brain. These areas in turn
indicate the areas passed by fiber tracts. Our proposed test statistic not only
takes into account the bias components in eigenvalue estimates, but also
incorporates the spatial information of neighboring voxels. Under mild
regularity conditions, we demonstrate that the proposed test statistic
asymptotically follows a $\chi^2$ distribution under the null hypothesis.
Simulation and real DTI data examples are provided to illustrate the efficacy
of our proposed methods.


title:
Resistive switching induced by electronic avalanche breakdown in
  GaTa$_4$Se$_{8-x}$Te$_x$ narrow gap Mott Insulators

abstract:
  Mott transitions induced by strong electric fields are receiving a growing
interest. Recent theoretical proposals have focused on the Zener dielectric
breakdown in Mott insulators, however experimental studies are still too scarce
to conclude about the mechanism. Here we report a study of the dielectric
breakdown in the narrow gap Mott insulators GaTa$_4$Se$_{8-x}$Te$_x$. We find
that the I-V characteristics and the magnitude of the threshold electric field
(E$_{th}$) do not correspond to a Zener breakdown, but rather to an avalanche
breakdown. E$_{th}$ increases as a power law of the Mott Hubbard gap (E$_g$),
in surprising agreement with the universal law E$_{th}$ $\propto$E$_g$$^{2.5}$
reported for avalanche breakdown in semiconductors. However, the delay time for
the avalanche that we observe in Mott insulators is over three orders of
magnitude longer than in conventional semiconductors. Our results suggest that
the electric field induces local insulator-to-metal Mott transitions that
create conductive domains which grow to form filamentary paths across the
sample.


title: Feasibility study on distributed simulations of BGP

abstract:
  The Autonomous System (AS)-level topology of the Internet that currently
comprises 40k ASs, is growing at a rate of about 10% per year. In these
conditions, Border Gateway Protocol (BGP), the inter-domain routing protocol of
the Internet starts to show its limits, among others in terms of the number of
routing table entries it can dynamically process and control. To overcome this
challenging situation, the design but also the evaluation of alternative
dynamic routing models and their comparison with BGP shall be performed by
means of simulation. For this purpose, DRMSim, a Dynamic Routing Model
Simulator, was developed that provides the means for large-scale simulations of
various routing models including BGP. By means of this discrete-event
simulator, execution of path-vector routing, e.g. BGP, and other compact
routing models have been successfully performed on network topologies
comprising more than ten thousand (abstract) nodes. However, to simulate
dynamic routing schemes like BGP, DRMSim needs enhancements to support current
Internet size (40k ASs) and even more by considering its evolution (up to 100k
ASs). This paper proposes a feasibility study of the extension of DRMSim so as
to support the Distributed Parallel Discrete Event paradigm. We first detail
the possible distribution models and their associated communication overhead.
Then, we analyze the communication overhead of such a distributed simulator by
executing BGP on a partitioned topology according to different scenarios.
Finally, we conclude on the feasibility of such a simulator by computing the
expected additional time required by a distributed simulation of BGP compared
to its sequential simulation.


title: The dynatomic curves for unimodel polynomials are smooth and irreducible

abstract:
  We prove here the smoothness and the irreducibility of the periodic dynatomic
curves $ (c,z)\in \C^2$ such that $z$ is $n$-periodic for $z^d+c$, where
$d\geq2$. We use the method provided by Xavier Buff and Tan Lei in \cite{BT}
where they prove the conclusion for $d=2$. The proof for smoothness is based on
elementary calculations on the pushforwards of specific quadratic
differentials, following Thurston and Epstein, while the proof for
irreducibility is a simplified version of Lau-Schleicher's proof by using
elementary arithmetic properties of kneading sequence instead of internal
addresses.


title:
Calculation of thermal conductivity coefficients for magnetized neutron
  star

abstract:
  The coefficients that determine the electron heat transfer and diffusion in
the crust of neutron stars are calculated on the basis of a solution of the
Boltzmann equation with allowance for degeneracy.


title:
History-independence of steady-state in simultaneous two-phase flow
  through porous media

abstract:
  It is well known that the transient behavior during drainage or imbibition in
multiphase flow in porous media strongly depends on the history and initial
condition of the system. However, when the steady-state regime is reached and
both drainage and imbibition take place at the pore level, the influence of the
evolution history and initial preparation is an open question. Here, we present
an extensive experimental and numerical work investigating the history
dependence of simultaneous steady-state two-phase flow through porous media.
Our experimental system consists of a Hele-Shaw cell filled with glass beads
which we model numerically by a network of disordered pores transporting two
immiscible fluids. From the measurements of global pressure evolution,
histogram of saturation and cluster-size distributions, we find that when both
phases are flowing through the porous medium, the steady state does not depend
on the initial preparation of the system or on the way it has been reached.


title:
Hybridization of quantum plasmon modes in coupled nanowires: From the
  classical to the tunneling regime

abstract:
  We present full quantum mechanical calculations of the hybridized plasmon
modes of two nanowires at small separation, providing real space visualization
of the modes in the transition from the classical to the quantum tunneling
regime. The plasmon modes are obtained as certain eigenfunctions of the
dynamical dielectric function which is computed using time dependent density
functional theory (TDDFT). For freestanding wires, the energy of both surface
and bulk plasmon modes deviate from the classical result for low wire radii and
high momentum transfer due to effects of electron spill-out, non-local
response, and coupling to single-particle transitions. For the wire dimer the
shape of the hybridized plasmon modes are continuously altered with decreasing
separation, and below 6 {\AA} the energy dispersion of the modes deviate from
classical results due to the onset of weak tunneling. Below 2-3 {\AA}
separation this mode is replaced by a charge-transfer plasmon which blue shifts
with decreasing separation in agreement with experiment, and marks the onset of
the strong tunneling regime.


title: Magnetic coupling of porphyrin molecules through graphene

abstract:
  Graphene is expected to complement todays Si-based information technology. In
particular, magnetic molecules in contact with graphene constitute a
tantalizing approach towards organic spin electronics because of the reduced
conductivity mismatch at the interface. In such a system a bit is represented
by a single molecular magnetic moment, which must be stabilized against thermal
fluctuations. Here, we show in a combined experimental and theoretical study
that the moments of paramagnetic Co-octaethylporphyrin (CoOEP) molecules on
graphene can be aligned by a remarkable antiferromagnetic coupling to a Ni
substrate underneath the graphene. This coupling is mediated via the \pi\
electronic system of graphene, while no covalent bonds between the molecule and
the substrate are established.


title:
Excitation-induced dephasing in a resonantly driven InAs/GaAs quantum
  dot

abstract:
  We report on coherent emission of the neutral exciton state in a single
semiconductor self-assembled InAs/GaAs quantum dot embedded in a
one-dimensional waveguide, under resonant picosecond pulsed excita- tion.
Direct measurements of the radiative lifetime and coherence time are performed
as a function of excitation power and temperature. The characteristic damping
of Rabi oscillations which is observed, is attributed to an excitation-induced
dephasing due to a resonant coupling between the emitter and the acoustic
phonon bath of the matrix. Other sources responsible for the decrease of the
coherence time have been evidenced, in particular an enhancement of the
radiative recombination rate due to the resonant strong coupling between the
dot and the one-dimensional optical mode. As a consequence, the emission
couples very efficiently into the waveguide mode leading to an additional
relaxation term of the excited state population.


title: Finite temperature behaviour of glueballs in Lattice Gauge Theories

abstract:
  We propose a new method to compute glueball masses in finite temperature
Lattice Gauge Theories which at low temperature is fully compatible with the
known zero temperature results and as the temperature increases leads to a
glueball spectrum which vanishes at the deconfinement transition. We show that
this definition is consistent with the Isgur-Paton model and with the expected
contribution of the glueball spectrum to various thermodynamic quantities at
finite temperature. We test our proposal with a set of high precision numerical
simulations in the 3d gauge Ising model and find a good agreement with our
predictions.


title: Bitcoin and Beyond: Exclusively Informational Monies

abstract:
  The famous new money Bitcoin is classified as a technical informational money
(TIM). Besides introducing the idea of a TIM, a more extreme notion of
informational money will be developed: exclusively informational money (EXIM).
  The informational coins (INCOs) of an EXIM can be in control of an agent but
are not owned by any agent. INCOs of an EXIM cannot be stolen, but they can be
lost, or thrown away. The difference between an EXIM and a TIM shows up when
considering a user perspective on security matters. Security for an EXIM user
is discussed in substantial detail, with the remarkable conclusion that
computer security (security models, access control, user names, passwords,
firewalls etc.) is not always essential for an EXIM, while the application of
cryptography based information security is unavoidable for the use of an EXIM.
  Bitcoin seems to meet the criteria of an EXIM, but the assertion that
"Bitcoin is an EXIM", might also be considered problematic. As a thought
experiment we will contemplate Bitguilder, a hypothetical copy of Bitcoin that
qualifies as an EXIM.
  A business ethics assessment of Bitcoin is made which reveals a number of
worries. By combining Bitguilder with a so-called technical informational
near-money (TINM) a dual money system, having two units with a fluctuating
rate, may be obtained. It seems that a dual money can remedy some, but not all,
of the ethical worries that arise when contemplating Bitcoin after
hypothetically having become a dominant form of money.
  The contributions that Bitcoin's designers can potentially make to the
evolution of EXIMs and TIMs is analyzed in terms of the update of the portfolio
of money related natural kinds that comes with Bitcoin.


title: Commutativity properties of Quinn spectra

abstract:
  We give a simple sufficient condition for Quinn's "bordism-type" spectra to
be weakly equivalent to commutative symmetric ring spectra. We also show that
the symmetric signature is (up to weak equivalence) a monoidal transformation
between symmetric monoidal functors, which implies that the Sullivan-Ranicki
orientation of topological bundles is represented by a ring map between
commutative symmetric ring spectra. In the course of proving these statements
we give a new description of symmetric L theory which may be of independent
interest.


title: Long-range Ordering of Vibrated Polar Disks

abstract:
  Vibrated polar disks have been used experimentally to investigate collective
motion of driven particles, where fully-ordered asymptotic regimes could not be
reached. Here we present a model reproducing quantitatively the single, binary
and collective properties of this granular system. Using system sizes not
accessible in the laboratory, we show in silico that true long-range order is
possible in the experimental system. Exploring the model's parameter space, we
find a phase diagram qualitatively different from that of dilute or point-like
particle systems.


title:
Analyzing the effects of post couplers in DTL tuning by the equivalent
  circuit model

abstract:
  Stabilization of the accelerating field in Drift Tube Linac(DTL) is obtained
by inserting Post Couplers(PCs).On the basis of the circuit model equivalent
for the DTL with and without asymmetrical PCs, stabilization is deduced
quantitatively: let $\delta \omega/\omega_0$ be the relative frequency error,
then we discover that the sensitivity of field to perturbation is proportional
to $\sqrt{\delta \omega / \omega_0}$ without PCs and to $\delta
\omega/\omega_0$ with PCs. Then we adapt the circuit model of symmetrical PCs
for the case of asymmetrical PCs. The circuit model shows how the slope of
field distribution is changed by rotating the asymmetrical PCs and illustrates
that the asymmetrical PCs have the same effect as the symmetrical ones in
stabilization.


title:
The formation of systems with closely spaced low-mass planets and the
  application to Kepler-36

abstract:
  The Kepler-36 system consists of two planets that are spaced unusually close
together, near the 7:6 mean motion resonance. While it is known that mean
motion resonances can easily form by convergent migration, Kepler-36 is an
extreme case due to the close spacing and the relatively high planet masses of
4 and 8 times that of the Earth. In this paper, we investigate whether such a
system can be obtained by interactions with the protoplanetary disc. These
discs are thought to be turbulent and exhibit density fluctuations which might
originate from the magneto-rotational instability. We adopt a realistic
description for stochastic forces due to these density fluctuations and perform
both long term hydrodynamical and N-body simulations. Our results show that
planets in the Kepler-36 mass range can be naturally assembled into a closely
spaced planetary system for a wide range of migration parameters in a turbulent
disc similar to the minimum mass solar nebula. The final orbits of our
formation scenarios tend to be Lagrange stable, even though large parts of the
parameter space are chaotic and unstable.


title: Dynamics of Stochastic Epidemics on Heterogeneous Networks

abstract:
  Epidemic models currently play a central role in our attempts to understand
and control infectious diseases. Here, we derive a model for the diffusion
limit of stochastic susceptible-infectious-removed (SIR) epidemic dynamics on a
heterogeneous network. Using this, we consider analytically the early
asymptotic exponential growth phase of such epidemics, showing how the higher
order moments of the network degree distribution enter into the stochastic
behaviour of the epidemic. We find that the first three moments of the network
degree distribution are needed to specify the variance in disease prevalence
fully, meaning that the skewness of the degree distribution affects the
variance of the prevalence of infection. We compare these asymptotic results to
simulation and find a close agreement for city-sized populations.


title:
Lifshitz and Excited State Quantum Phase Transitions in Microwave Dirac
  Billiards

abstract:
  We present experimental results for the density of states (DOS) of a
superconducting microwave Dirac billiard which serves as an idealized model for
the electronic properties of graphene. The DOS exhibits two sharp peaks which
evolve into van Hove singularities with increasing system size. They divide the
band structure into regions governed by the \emph{relativistic} Dirac equation
and by the \emph{non-relativistic} Schr\"odinger equation, respectively. We
demonstrate that in the thermodynamic limit a topological transition appears as
a neck-disrupting Lifshitz transition in the number susceptibility and as an
excited state transition in the electronic excitations. Furthermore, we recover
the finite-size scaling typical for excited state quantum phase transitions
involving logarithmic divergences and identify a quasi-order parameter.

categories: cond-mat.mes-hall cond-mat.str-el nucl-ex nucl-th


title: Robust Noise Filtering in Image Sequences

abstract:
  Image sequences filtering have recently become a very important technical
problem especially with the advent of new technology in multimedia and video
systems applications. Often image sequences are corrupted by some amount of
noise introduced by the image sensor and therefore inherently present in the
imaging process. The main problem in the image sequences is how to deal with
spatio-temporal and non stationary signals. In this paper, we propose a robust
method for noise removal of image sequence based on coupled spatial and
temporal anisotropic diffusion. The idea is to achieve an adaptive smoothing in
both spatial and temporal directions, by solving a nonlinear diffusion
equation. This allows removing noise while preserving all spatial and temporal
discontinuities


title: High-speed and accurate color-space short-read alignment with CUSHAW2

abstract:
  Summary: We present an extension of CUSHAW2 for fast and accurate alignments
of SOLiD color-space short-reads. Our extension introduces a double-seeding
approach to improve mapping sensitivity, by combining maximal exact match seeds
and variable-length seeds derived from local alignments. We have compared the
performance of CUSHAW2 to SHRiMP2 and BFAST by aligning both simulated and real
color-space mate-paired reads to the human genome. The results show that
CUSHAW2 achieves comparable or better alignment quality compared to SHRiMP2 and
BFAST at an order-of-magnitude faster speed and significantly smaller peak
resident memory size. Availability: CUSHAW2 and all simulated datasets are
available at http://cushaw2.sourceforge.net. Contact: liuy@uni-mainz.de;
bertil.schmidt@uni-mainz.de


title:
Multiple solutions for a NLS equation with critical growth and magnetic
  field

abstract:
  In this paper, we are concerned with the multiplicity of nontrivial solutions
for the following class of complex problems $$ (-i\nabla - A(\mu x))^{2}u= \mu
|u|^{q-2}u + |u|^{2^{*}-2}u \ \mbox{in} \ \Omega, \ \ \ \ u \in
H^{1}_{0}(\Omega,\mathbb{C}), $$ where $\Omega \subset \mathbb{R}^{N} (N \geq
4)$ is a bounded domain with smooth boundary. Using the Lusternik-Schnirelman
theory, we relate the number of solutions with the topology of $\Omega$.


title: Asymptotics of the N\'eron height pairing

abstract:
  The aim of this paper is twofold. First, we study the asymptotics of the
N\'eron height pairing between degree-zero divisors on a family of degenerating
compact Riemann surfaces parametrized by an algebraic curve. We show that if
the monodromy is unipotent the leading term of the asymptotics is controlled by
the local non-archimedean N\'eron height pairing on the generic fiber of the
family. Second, we prove a conjecture of R. Hain to the effect that the `height
jumping divisor' related to the normal function $(2g-2)x-K$ on the moduli space
$\mm_{g,1}$ of 1-pointed curves of genus $g \geq 2$ is effective. Both results
follow from a study of the degeneration of the canonical metric on the
Poincar\'e bundle on a family of jacobian varieties.


title:
Magnetism and electronic structure of La2ZnIrO6 and La2MgIrO6: candidate
  Jeff =1/2 Mott insulators

abstract:
  We study experimentally and theoretically the electronic and magnetic
properties of two insulating double perovskites that show similar atomic and
electronic structure, but different magnetic properties. In magnetization
measurements, La2ZnIrO6 displays weak ferromagnetic behavior below 7.5 K
whereas La2MgIrO6 shows antiferromagnetic behavior (AFM) below TN = 12 K.
Electronic structure calculations find that the weak ferromagnetic behavior
observed in La2ZnIrO6 is in fact due to canted antiferromagnetism. The
calculations also predict canted antiferromagnetic behavior in La2MgIrO6, but
intriguingly this was not observed. Neutron diffraction measurements confirm
the essentially antiferromagnetic behavior of both systems, but lack the
sensitivity to resolve the small (0.22 {\mu}B/Ir) ferromagnetic component in
La2ZnIrO6. Overall, the results presented here indicate the crucial role of
spin-orbit coupling (SOC) and the on-site Coulomb repulsion on the magnetic,
transport, and thermodynamic properties of both compounds. The electronic
structure calculations show that both compounds, like Sr2IrO4, are Jeff = 1/2
Mott insulators. Our present findings suggest that La2ZnIrO6 and La2MgIrO6
provide a new playground to study the interplay between SOC and on-site Coulomb
repulsion in a 5d transition metal oxide.


title: Control of Surface Wettability via Strain Engineering

abstract:
  Reversible control of surface wettability has wide applications in
lab-on-chip systems, tunable optical lenses, and microfluidic tools. Using a
graphene sheet as a sample material and molecular dynamic (MD) simulations, we
demonstrate that strain engineering can serve as an effective way to control
the surface wettability. The contact angles $\theta$ of water droplets on a
graphene vary from 72.5$^\circ$ to 106$^\circ$ under biaxial strains ranging
from -10% to 10% that are applied on the graphene layer. For an intrinsic
hydrophilic surface (at zero strain), the variation of $\theta$ upon the
applied strains is more sensitive, i.e., from 0$^\circ$ to 74.8$^\circ$.
Overall the cosines of the contact angles exhibit a linear relation with
respect to the strains. In light of the inherent dependence of the contact
angle on liquid-solid interfacial energy, we develop an analytic model to show
the $\cos \theta$ as a linear function of the adsorption energy $E_{ads}$ of a
single water molecule over the substrate surface. This model agrees with our MD
results very well. Together with the linear dependence of $E_{ads}$ on biaxial
strains, we can thus understand the effect of strains on the surface
wettability. Thanks to the ease of reversibly applying mechanical strains in
micro/nano-electromechanical systems (MEMS/NEMS), we believe that strain
engineering can be a promising means to achieve the reversibly control of
surface wettability.


title: Short Time Quantum Propagator and Bohmian Trajectories

abstract:
  We begin by giving correct expressions for the short-time action; following
the work of one of us and Makri--Miller. We use these estimates to derive a
correct expression modulo modulo delta(t)sqr for the quantum propagator and we
show that the quantum potential is negligible modulo delta(t)sqr for a point
source. We finally prove that this implies that the quantum motion is classical
for very short times.


title:
Derivation of a linear collision operator for the spinorial Wigner
  equation and its semiclassical limit

abstract:
  We systematically derive a linear quantum collision operator for the
spinorial Wigner transport equation from the dynamics of a composite quantum
system. For suitable two particle interaction potentials, the particular matrix
form of the collision operator describes spin decoherence or even spin
depolarization as well as relaxation towards a certain momentum distribution in
the long time limit. It is demonstrated that in the semiclassical limit the
spinorial Wigner equation gives rise to several semiclassical spin-transport
models. As an example, we derive the Bloch equations as well as the spinorial
Boltzmann equation, which in turn gives rise to spin drift-diffusion models
which are increasingly used to describe spin-polarized transport in spintronic
devices. The presented derivation allows to systematically incorporate
Born-Markov as well as quantum corrections into these models.


title:
Sparse least trimmed squares regression for analyzing high-dimensional
  large data sets

abstract:
  Sparse model estimation is a topic of high importance in modern data analysis
due to the increasing availability of data sets with a large number of
variables. Another common problem in applied statistics is the presence of
outliers in the data. This paper combines robust regression and sparse model
estimation. A robust and sparse estimator is introduced by adding an $L_1$
penalty on the coefficient estimates to the well-known least trimmed squares
(LTS) estimator. The breakdown point of this sparse LTS estimator is derived,
and a fast algorithm for its computation is proposed. In addition, the sparse
LTS is applied to protein and gene expression data of the NCI-60 cancer cell
panel. Both a simulation study and the real data application show that the
sparse LTS has better prediction performance than its competitors in the
presence of leverage points.


title: Understanding the structure of the first atomic contact in Gold

abstract:
  We have studied experimentally the phenomena of jump-to-contact (JC) and
jump-out-of-contact (JOC) in gold electrodes. JC can be observed at the first
contact when the two metals approach each other while JOC occurs in the last
contact before breaking. When the indentation depth between the electrodes is
limited to a certain value of conductance, a highly reproducible behaviour in
the evolution of the conductance can be obtained for hundreds of cycles of
formation and rupture. Molecular dynamics simulations of this process show how
the two metallic electrodes are shaped into tips of a well-defined
crystallographic structure formed through a mechanical annealing mechanism. We
report a detailed analysis of the atomic configurations obtained before contact
and rupture of these stable structures and obtained their conductance using
first-principlesquantum transport calculations. These results help us
understand the values of conductance obtained experimentally in the JC and JOC
phenomena and improve our understanding of atomic-sized contacts and the
evolution of their structural characteristics.


title:
Marriage of Electromagnetism and Gravity in Extended Space Model and
  Astrophysical Phenomena

abstract:
  The generalization of Einstein's special theory of relativity (SRT) is
proposed. In this model the possibility of unification of scalar gravity and
electromagnetism into a single united field is considered. Formally, the
generalization of the SRT is that instead of (1+3)-dimensional Minkowski space
the (1+4)-dimensional extension G is considered. As a fifth additional
coordinate the interval S is used. This value is saved under the usual Lorentz
transformations in Minkowski space M, but it changes when the transformations
in the extended space G are used. We call this model the extended space model
(ESM). From a physical point of view our expansion means that processes in
which the rest mass of the particles changes are acceptable now. If the rest
mass of a particle does not change and the physical quantities do not depend on
an additional variable S, then the electromagnetic and gravitational fields
exist independently of each other. But if the rest mass is variable and there
is a dependence on S, then these two fields are combined into a single united
field. In the extended space model a photon can have a nonzero mass and this
mass can be either positive or negative. The gravitational effects such as the
speed of escape, gravitational red shift and deflection of light can be
analyzed in the frame of the extended space model. In this model all these
gravitational effects can be found algebraically by the rotations in the (1+4)
dimensional space. Now it becomes possible to predict some future results of
visible size of super massive objects in our Universe due to new stage of
experimental astronomy development in the Radio Astron Project and analyze
phenomena of the star V838 Monocerotis explosion as possible Local Big Bang
(LBB).


title: Braids, Complex Volume, and Cluster Algebra

abstract:
  We try to give a cluster algebraic interpretation of complex volume of knots.
We construct the R-operator from the cluster mutations, and we show that it is
regarded as a hyperbolic octahedron. The cluster variables are interpreted as
edge parameters used by Zickert in computing complex volume.


title:
Consistent closure of renormalization group flow equations in quantum
  gravity

abstract:
  We construct a consistent closure for the beta functions of the cosmological
and Newton's constants by evaluating the influence of the fluctuating metric
and ghost fields anomalous dimensions on their flow. In this generalized
framework we confirm the presence of a UV attractive non-Gaussian fixed-point.
Our closure method is general and can be applied systematically to more general
truncations of the gravitational effective average action.


title: Finite-Length Scaling of Polar Codes

abstract:
  Consider a binary-input memoryless output-symmetric channel $W$. Such a
channel has a capacity, call it $I(W)$, and for any $R<I(W)$ and strictly
positive constant $P_{\rm e}$ we know that we can construct a coding scheme
that allows transmission at rate $R$ with an error probability not exceeding
$P_{\rm e}$. Assume now that we let the rate $R$ tend to $I(W)$ and we ask how
we have to "scale" the blocklength $N$ in order to keep the error probability
fixed to $P_{\rm e}$. We refer to this as the "finite-length scaling" behavior.
This question was addressed by Strassen as well as Polyanskiy, Poor and Verdu,
and the result is that $N$ must grow at least as the square of the reciprocal
of $I(W)-R$.
  Polar codes are optimal in the sense that they achieve capacity. In this
paper, we are asking to what degree they are also optimal in terms of their
finite-length behavior. Our approach is based on analyzing the dynamics of the
un-polarized channels. The main results of this paper can be summarized as
follows. Consider the sum of Bhattacharyya parameters of sub-channels chosen
(by the polar coding scheme) to transmit information. If we require this sum to
be smaller than a given value $P_{\rm e}>0$, then the required block-length $N$
scales in terms of the rate $R < I(W)$ as $N \geq
\frac{\alpha}{(I(W)-R)^{\underline{\mu}}}$, where $\alpha$ is a positive
constant that depends on $P_{\rm e}$ and $I(W)$, and $\underline{\mu} = 3.579$.
Also, we show that with the same requirement on the sum of Bhattacharyya
parameters, the block-length scales in terms of the rate like $N \leq
\frac{\beta}{(I(W)-R)^{\overline{\mu}}}$, where $\beta$ is a constant that
depends on $P_{\rm e}$ and $I(W)$, and $\overline{\mu}=6$.


title: The Farrell-Jones Conjecture for the solvable Baumslag-Solitar groups

abstract:
  In this paper, we prove the Farrell-Jones Conjecture for the solvable
Baumslag-Solitar groups with coefficients in an additive category. We also
extend our results to groups of the form, Z[1/p] semidirect product with any
virtually cyclic group, where p is a prime number.


title: Thermodynamics of the apparent horizon in massive cosmology

abstract:
  Applying Clausius relation with energy-supply defined by the unified first
law of thermodynamics formalism to the apparent horizon of a massive
cosmological model proposed lately, the corrected entropic formula of the
apparent horizon is obtained with the help of the modified Friedmann equations.
This entropy-area relation, together with the identified internal energy,
verifies the first law of thermodynamics for the apparent horizon with a volume
change term for consistency. On the other hand, by means of the corrected
entropy-area formula and the Clausius relation $\delta Q=T dS$, the modified
Friedmann equations governing the dynamical evolution of the universe are
reproduced with the known energy density and pressure of massive graviton. The
integration constant is found to correspond to a cosmological term which could
be absorbed into the energy density of matter. Having established the
correspondence of massive cosmology with the unified first law of
thermodynamics on the apparent horizon, the validity of the generalized second
law of thermodynamics is also discussed by assuming the thermal equilibrium
between the apparent horizon and the matter field bounded by the apparent
horizon. It is found that, in the limit $H_c\rightarrow 0$ which recovers the
Minkowski reference metric solution in the flat case, the generalized second
law of thermodynamics holds if $\alpha_3+4\alpha_4<0$. Apart from that, even
for the simplest model of dRGT massive cosmology with $\alpha_3=\alpha_4=0$,
the generalized second law of thermodynamics could be violated.


title:
A quasi-Gaussian approximation for the probability distribution of
  correlation functions

abstract:
  Context. Whenever correlation functions are used for inference about
cosmological parameters in the context of a Bayesian analysis, the likelihood
function of correlation functions needs to be known. Usually, it is
approximated as a multivariate Gaussian, though this is not necessarily a good
approximation.
  Aims. We show how to calculate a better approximation for the probability
distribution of correlation functions, which we call "quasi-Gaussian".
  Methods. Using the exact univariate PDF as well as constraints on correlation
functions previously derived, we transform the correlation functions to an
unconstrained variable for which the Gaussian approximation is well justified.
From this Gaussian in the transformed space, we obtain the quasi-Gaussian PDF.
The two approximations for the probability distributions are compared to the
"true" distribution as obtained from simulations. Additionally, we test how the
new approximation performs when used as likelihood in a toy-model Bayesian
analysis.
  Results. The quasi-Gaussian PDF agrees very well with the PDF obtained from
simulations; in particular, it provides a significantly better description than
a straightforward copula approach. In a simple toy-model likelihood analysis,
it yields noticeably different results than the Gaussian likelihood, indicating
its possible impact on cosmological parameter estimation.


title:
Asymptotics of the partition function of a Laguerre-type random matrix
  model

abstract:
  We study asymptotics of the partition function $Z_N$ of a Laguerre-type
random matrix model when the matrix order $N$ tends to infinity. By using the
Deift-Zhou steepest descent method for Riemann-Hilbert problems, we obtain an
asymptotic expansion of $\log Z_N$ in powers of $N^{-2}$.


title:
Appearance of vortices and monopoles in a decomposition of an SU(2)
  Yang-Mills field

abstract:
  We show how vortices can appear in the low energy limit of a pure SU(2)
Yang-Mills theory as topological solitons. Motivated by Abelian dominance, we
suppose that in the infrared regime of the SU(2) Yang-Mills theory, the field
strength tensor can be obtained by multiplying two parts: $ G_{\mu\nu} $ and $
\textbf{n} $ such that $ \textbf{G}_{\mu\nu}=G_{\mu\nu} \textbf{n} $. The first
part, $ G_{\mu\nu} $, is a space-time tensor and the second part, $ \textbf{n}
$, is an isotriplet unit vector field which gives the Abelian direction at each
space-time point. This leads to a decomposition for the SU(2) Yang-Mills field
in the infrared regime. We show that vortices as well as monopoles can appear
as a result of this decomposition where we have started with a pure Yang-Mills
theory and we have ended up with a theory with an Abelian gauge field coupled
to a scalar field. The effect of this scalar field on monopoles is also
discussed.


title: Embeddable box spaces of free groups

abstract:
  We generalize the construction of Arzhantseva, Guentner and Spakula of a box
space of the free group which admits a coarse embedding into Hilbert space. We
show that for a finitely generated free group, the box space corresponding to
the derived $m$-series (for any integer $m\geq 2$) coarsely embeds into Hilbert
space. This gives new examples of metric spaces with bounded geometry which
coarsely embed into Hilbert space but do not have Yu's property A.


title: A short proof of the thumbtack lemma

abstract:
  We give a short proof of the main algebraic result of
\cite{zilber2006covers}, also known as the `thumbtack lemma'.


title:
The Mahalanobis distance for functional data with applications to
  classification

abstract:
  This paper presents a general notion of Mahalanobis distance for functional
data that extends the classical multivariate concept to situations where the
observed data are points belonging to curves generated by a stochastic process.
More precisely, a new semi-distance for functional observations that generalize
the usual Mahalanobis distance for multivariate datasets is introduced. For
that, the development uses a regularized square root inverse operator in
Hilbert spaces. Some of the main characteristics of the functional Mahalanobis
semi-distance are shown. Afterwards, new versions of several well known
functional classification procedures are developed using the Mahalanobis
distance for functional data as a measure of proximity between functional
observations. The performance of several well known functional classification
procedures are compared with those methods used in conjunction with the
Mahalanobis distance for functional data, with positive results, through a
Monte Carlo study and the analysis of two real data examples.


title: Categoricity of the two sorted j-function

abstract:
  We show that a natural, two sorted $\cL_{\omega_1,\omega}$ theory involving
the modular $j$-function is categorical in all uncountable cardinaities. It is
also shown that a slight weakening of the adelic Mumford-Tate conjecture for
products of elliptic curves is necessary and (along with a couple of other
results from arithmetic geometry) sufficient for categoricity.


title:
A curious instability phenomenon for a rounded corner in presence of a
  negative material

abstract:
  We study a 2D scalar harmonic wave transmission problem between a classical
dielectric and a medium with a real-valued negative permittivity/permeability
which models a metal at optical frequency or an ideal negative metamaterial. We
highlight an unusual instability phenomenon for this problem when the interface
between the two media presents a rounded corner. To establish this result, we
provide an asymptotic expansion of the solution, when it is well-defined, in
the geometry with a rounded corner. Then, we prove error estimates. Finally, a
careful study of the asymptotic expansion allows us to conclude that the
solution, when it is well-defined, depends critically on the value of the
rounding parameter. We end the paper with a numerical illustration of this
instability phenomenon.


title:
Simulation study of pressure and temperature dependence of the negative
  thermal expansion in Zn(CN)$_2$

abstract:
  Pressure and temperature dependence of the negative thermal expansion in
Zn(CN)$_2$ is fully investigated using molecular dynamics simulations with a
built potential model. The advantage of this study allows us to reproduce all
the exotic behaviours of the material, including the negative thermal expansion
(NTE), the reduction of NTE with elevated temperature, the pressure enhancement
of NTE and the pressure-induced softening. Results of the study provide us
detailed data to link the properties in the energy space and the real space,
giving us insights to understand the properties and the connections between
them.


title:
Tailoring electronic and elastic properties by varying composition of
  the CuGa1-xAlxS2 chalcopyrite semiconductor

abstract:
  Influence of composition and external hydrostatic pressure on the structural,
electronic, and optical properties of the CuGa1-xAlxS2 (x=0, 0.25, 0.5, 0.75,
1.0) chalcopyrite semiconductor was analyzed by means of the first-principles
calculations. Dielectric functions and optical absorption spectra were
calculated for all considered aluminum concentrations. The pressure
coefficients of the calculated band gaps and position of the lowest in energy
absorption peaks were extracted from the calculated results. One of the main
results is that substitution of 25% of gallium by aluminum (thus forming the
CuGa0.75Al0.25S2 semiconductor) increases absorption in the visible part of the
solar spectrum by about 6%, which can be important for the solar cell
applications.


title: Size of a 3-uniform linear hypergraph

abstract:
  This article provides bounds on the size of a 3-uniform linear hypergraph
with restricted matching number and maximum degree. In particular, we show that
if a 3-uniform, linear family $\mathcal{F}$ has maximum matching size $\nu$ and
maximum degree $\Delta$ such that $\Delta\geq
\frac{23}{6}\nu(1+\frac{1}{\nu-1})$, then $|\mathcal{F}|\leq \Delta \nu$.


title: Correlations of quasi-2D dipolar ultracold gas at finite temperatures

abstract:
  We study a quasi two dimensional dipolar gas at finite, but ultralow
temperatures using the classical field approximation. The method, already used
for a contact interacting gas, is extended here to samples with a weakly
interacting long-range inter-atomic potential. We present statistical
properties of the system for the current experiment with Chromium [Phys. Rev. A
84 053601 (2011)] and compare them with statistics for atoms with larger
magnetic dipole moments. Significant enhancement of the third order correlation
function, relevant for the particle losses, is found.


title:
Acetone in Orion BN/KL - High-resolution maps of a special
  oxygen-bearing molecule

abstract:
  As one of the prime targets of interstellar chemistry study, Orion BN/KL
clearly shows different molecular distributions between large nitrogen- (e.g.,
C2H5CN) and oxygen-bearing (e.g., HCOOCH3) molecules. However, acetone
(CH3)2CO, a special complex O-bearing molecule, has been shown to have a very
different distribution from other typical O-bearing molecules in the BN/KL
region. We searched for acetone within our IRAM Plateau de Bure Interferometer
3 mm and 1.3 mm data sets. Twenty-two acetone lines were searched within these
data sets. The angular resolution ranged from 1.8 X 0.8 to 6.0 X 2.3 arcsec^2,
and the spectral resolution ranged from 0.4 to 1.9 km s-1. Nine of the acetone
lines appear free of contamination. Three main acetone peaks (Ace-1, 2, and 3)
are identified in Orion BN/KL. The new acetone source Ace-3 and the extended
emission in the north of the hot core region have been found for the first
time. An excitation temperature of about 150 K is determined toward Ace-1 and
Ace-2, and the acetone column density is estimated to be 2-4 X 10^16 cm-2 with
a relative abundance of 1-6 X 10^-8 toward these two peaks. Acetone is a few
times less abundant toward the hot core and Ace-3 compared with Ace-1 and
Ace-2.
  We find that the overall distribution of acetone in BN/KL is similar to that
of N-bearing molecules, e.g., NH3 and C2H5CN, and very different from those of
large O-bearing molecules, e.g., HCOOCH3 and (CH3)2O. Our findings show the
acetone distribution is more extended than in previous studies and does not
originate only in those areas where both N-bearing and O-bearing species are
present. Moreover, because the N-bearing molecules may be associated with
shocked gas in Orion BN/KL, this suggests that the formation and/or destruction
of acetone may involve ammonia or large N-bearing molecules in a shocked-gas
environment.


title: An Identification of the Dirac Operator with the Parity Operator

abstract:
  We provide a new derivation of the Dirac equation which promptly generalizes
to higher spins. We apply this idea to spin-half Elko dark matter.


title:
Recursive Mechanism: Towards Node Differential Privacy and Unrestricted
  Joins [Full Version, Draft 0.1]

abstract:
  Existing studies on differential privacy mainly consider aggregation on data
sets where each entry corresponds to a particular participant to be protected.
In many situations, a user may pose a relational algebra query on a sensitive
database, and desires differentially private aggregation on the result of the
query. However, no known work is capable to release this kind of aggregation
when the query contains unrestricted join operations. This severely limits the
applications of existing differential privacy techniques because many data
analysis tasks require unrestricted joins. One example is subgraph counting on
a graph. Existing methods for differentially private subgraph counting address
only edge differential privacy and are subject to very simple subgraphs. Before
this work, whether any nontrivial graph statistics can be released with
reasonable accuracy under node differential privacy is still an open problem.
  In this paper, we propose a novel differentially private mechanism to release
an approximation to a linear statistic of the result of some positive
relational algebra calculation over a sensitive database. Unrestricted joins
are supported in our mechanism. The error bound of the approximate answer is
roughly proportional to the \emph{empirical sensitivity} of the query --- a new
notion that measures the maximum possible change to the query answer when a
participant withdraws its data from the sensitive database. For subgraph
counting, our mechanism provides the first solution to achieve node
differential privacy, for any kind of subgraphs.


title: Extension of IIB Matrix Model by Three-Algebra

abstract:
  We construct a Lie 3-algebra extended model of the IIB matrix model. It
admits any Lie 3-algebra and possesses the same supersymmetry as the original
matrix model, and thus as type IIB superstring theory. We examine dynamics of
the model by taking minimal Lie 3-algebra that includes u(N) Lie algebra as an
example. There are two phases in the minimally extended model at least
classically. The extended action reduces to that of the IIB matrix model in one
phase. In other phase, it reduces to a more simple action, which is rather easy
to analyze.


title: Categoricity of modular and Shimura curves

abstract:
  We describe a model-theoretic setting for the study of Shimura varieties, and
study the interaction between model theory and arithmetic geometry in this
setting. In particular, we show that the model-theoretic statement of a certain
$\mathcal{L}_{\omega_1, \omega}$-sentence having a unique model of cardinality
$\aleph_1$ is equivalent to a condition regarding certain Galois
representations associated with Hodge-generic points. We then show that for
modular and Shimura curves this $\mathcal{L}_{\omega_1, \omega}$-sentence has a
unique model in every infinite cardinality. In the process, we prove a new
characterisation of the special points on any Shimura variety.


title:
Tunneling magneto thermocurrent in CoFeB/MgO/CoFeB based magnetic tunnel
  junctions

abstract:
  We study the tunneling magneto thermopower and tunneling magneto
thermocurrent of CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJ). The devices
show a clear change of the thermoelectric properties upon reversal of the
magnetisation of the CoFeB layers from parallel to the antiparallel
orientation. When switching from parallel to antiparallel the thermopower
increases by up to 55% where as the thermocurrent drops by 45%. These
observations can be well explained by the Onsager relations taking into account
the tunneling magneto resistance of the MTJ. These findings contrast previous
studies on AlO based MTJ systems, revealing tunneling magneto thermo power but
no tunneling magneto thermocurrent.


title:
Robust partial likelihood approach for detecting imprinting and maternal
  effects using case-control families

abstract:
  Genomic imprinting and maternal effects are two epigenetic factors that have
been increasingly explored for their roles in the etiology of complex diseases.
This is part of a concerted effort to find the "missing heritability."
Accordingly, statistical methods have been proposed to detect imprinting and
maternal effects simultaneously based on either a case-parent triads design or
a case-mother/control-mother pairs design. However, existing methods are
full-likelihood based and have to make strong assumptions concerning mating
type probabilities (nuisance parameters) to avoid overparametrization. In this
paper we propose to augment the two popular study designs by combining them and
including control-parent triads, so that our sample may contain a mixture of
case-parent/control-parent triads and case-mother/control-mother pairs. By
matching the case families with control families of the same structure and
stratifying according to the familial genotypes, we are able to derive a
partial likelihood that is free of the nuisance parameters. This renders
unnecessary any unrealistic assumptions and leads to a robust procedure without
sacrificing power. Our simulation study demonstrates that our partial
likelihood method has correct type I error rate, little bias and reasonable
power under a variety of settings.


title:
High spectral resolution imaging of the dynamical atmosphere of the red
  supergiant Antares in the CO first overtone lines with VLTI/AMBER

abstract:
  We present high spectral resolution aperture-synthesis imaging of the red
supergiant Antares (alpha Sco) in individual CO first overtone lines with
VLTI/AMBER. The reconstructed images reveal that the star appears differently
in the blue wing, line center, and red wing and shows an asymmetrically
extended component. The appearance of the star within the CO lines changes
drastically within one year, implying a significant change in the velocity
field in the atmosphere. Our modeling suggests an outer atmosphere (MOLsphere)
extending to 1.2--1.4 stellar radii with CO column densities of
(0.5--1)x10^{20} cm^{-2} and a temperature of ~2000 K. While the velocity field
in 2009 is characterized by strong upwelling motions at 20--30 km/s, it changed
to strong downdrafts in 2010. On the other hand, the AMBER data in the
continuum show only a slight deviation from limb-darkened disks and only
marginal time variations. We derive a limb-darkened disk diameter of
37.38+/-0.06 mas and a power-law-type limb-darkening parameter of
(8.7+/-1.6)x10^{-2} (2009) and 37.31+/-0.09 mas and (1.5+/-0.2)x10^{-1} (2010).
We also obtain Teff = 3660+/-120 K and log L/Lsun = 4.88+/-0.23, which suggests
a mass of 15+/-5 Msun with an age of 11-15 Myr. This age is consistent with the
recently estimated age for the Upper Scorpius OB association. The properties of
the outer atmosphere of Antares are similar to those of another well-studied
red supergiant, Betelgeuse. The density of the extended outer atmosphere of
Antares and Betelgeuse is higher than predicted by the current 3-D convection
simulations by at least six orders of magnitude, implying that convection alone
cannot explain the formation of the extended outer atmosphere.


title: Any nonlocal model assuming "local parts" conflicts with relativity

abstract:
  It is argued that any nonlocal model producing "local parts" (i.e.:
disappearance of the correlations under certain testable conditions) can be
reproduced by "multisimultaneity" and therefore (because of arxiv:1304.0532)
conflicts not only with quantum mechanics but also with relativity. This result
means in particular that the very structure of space-time (relativity) requires
influences coming from outside space-time.


title: Charged D3-D7 plasmas: novel solutions, extremality and stability issues

abstract:
  We study finite temperature N=4 Super Yang-Mills (and more general gauge
theories realized on intersecting D3-D7 branes) in the presence of dynamical
massless fundamental matter fields at finite baryon charge density. We
construct the holographic dual charged black hole solutions at first order in
the flavor backreaction but exact in the charge density. The thermodynamical
properties of the dual gauge theories coincide with the ones found in the usual
charged D7-probe limit and the system turns out to be thermodynamically stable.
By analyzing the higher order correction in the flavor backreaction, we provide
a novel argument for the un-reliability of the charged probe approximation (and
the present solution) in the extremality limit, i.e. at zero temperature.
  We then consider scalar mesonic-like bound states, whose spectrum is dual to
that of linearized fluctuations of D7-brane worldvolume fields around our
gravity backgrounds. In particular we focus on a scalar field saturating the
Breitenlohner-Freedman bound in the flavorless limit, and coupled to fields
dual to irrelevant operators. By looking at quasinormal modes of this scalar,
we find no signals of instabilities in the regime of validity of the solutions.


title:
Stability and metastability of clusters in a reactive atmosphere:
  theoretical evidence for unexpected stoichiometries of MgMOx

abstract:
  By applying a genetic algorithm in a cascade approach of increasing accuracy,
we calculate the composition and structure of MgMOx clusters at realistic
temperatures and oxygen pressures. The stable and metastable systems are
identified by ab initio atomistic thermodynamics. We find that small clusters
(M <= 5) are in thermodynamic equilibrium when x > M. The non-stoichiometric
clusters exhibit peculiar magnetic behavior, suggesting the possibility of
tuning magnetic properties by changing environmental pressure and temperature
conditions. Furthermore, we show that density-functional theory (DFT) with a
hybrid exchange-correlation (xc) functional is needed for predicting accurate
phase diagrams of metal-oxide clusters. Neither a (sophisticated) force field
nor DFT with (semi)local xc functionals are sufficient for even a qualitative
prediction.


title:
Rotational quenching of H2CO by molecular hydrogen: cross-sections,
  rates, pressure broadening

abstract:
  We compute the rotational quenching rates of the first 81 rotational levels
of ortho- and para-H2CO in collision with ortho- and para-H2, for a temperature
range of 10-300 K. We make use of the quantum close-coupling and coupled-states
scattering methods combined with the high accuracy potential energy surface of
Troscompt et al. (2009a). Rates are significantly different from the scaled
rates of H2CO in collision with He; consequently, critical densities are
noticeably lower. We compare a full close- coupling computation of pressure
broadening cross sections with experimental data and show that our results are
compatible with the low temperature measurements of Mengel & De Lucia (2000),
for a spin temperature of H2 around 50 K.


title:
Sliding invariants and classification of singular holomorphic foliations
  in the plane

abstract:
  By introducing a new invariant called the set of slidings, we give a complete
strict classification of the class of germs of non-dicritical holomorphic
foliations in the plan whose Camacho-Sad indices are not rational. Moreover, we
will show that, in this class, the new invariant is finitely determined.
Consequently, the finite determination of the class of isoholonomic
non-dicritical foliations and absolutely dicritical foliations that have the
same Dulac maps are proved.


title: Unsupervised model-free representation learning

abstract:
  Numerous control and learning problems face the situation where sequences of
high-dimensional highly dependent data are available but no or little feedback
is provided to the learner, which makes any inference rather challenging. To
address this challenge, we formulate the following problem. Given a series of
observations $X_0,\dots,X_n$ coming from a large (high-dimensional) space
$\mathcal X$, find a representation function $f$ mapping $\mathcal X$ to a
finite space $\mathcal Y$ such that the series $f(X_0),\dots,f(X_n)$ preserves
as much information as possible about the original time-series dependence in
$X_0,\dots,X_n$. We show that, for stationary time series, the function $f$ can
be selected as the one maximizing a certain information criterion that we call
time-series information. Some properties of this functions are investigated,
including its uniqueness and consistency of its empirical estimates.
  Implications for the problem of optimal control are presented.


title:
On the accurate characterization of business cycles in nonlinear dynamic
  financial and economic systems

abstract:
  The accurate characterization of the business cycles in the nonlinear dynamic
financial and economic systems in the time of globalization represents a
formidable research problem. The central banks and other financial institutions
make their decisions on the minimum capital requirements, countercyclical
capital buffer allocation and capital investments, going from the precise data
on the business cycles. We consider the two possible interaction scenarios,
when there are: the linear interactions, and the non-linear interactions. In
our opinion, the main parameters of the business cycle may deviate during the
business cycle nonlinear interaction with the nonlinear dynamic financial and
economic systems, because of the origination of the nonlinear effects such as
the Four Waves Mixing (FWM), Stimulated Brillouin Scattering (SBS), Stimulated
Raman Scattering (SRS), Carrier Induced Phase Modulation.


title: Characteristic Laplacian in sub-Riemannian geometry

abstract:
  We study a Laplacian operator related to the characteristic cohomology of a
smooth manifold endowed with a distribution. We prove that this Laplacian does
not behave very well: it is not hypoelliptic in general and does not respect
the bigrading on forms in a complex setting. We also discuss the consequences
of these negative results for a conjecture of P. Griffiths, concerning the
characteristic cohomology of period domains.


title:
The search for Nanobubbles by using specular and off-specular Neutron
  Reflectometry

abstract:
  We apply specular and off-specular neutron reflection at the hydrophobic
silicon/water interface to check for evidence of nanoscopic air bubbles whose
presence is claimed after an ad hoc procedure of solvent exchange. Nanobubbles
and/or a depletion layer at the hydrophobic/water interface have long been
discussed and generated a plethora of controversial scientific results. By
combining neutron reflectometry (NR), off-specular reflectometry (OSS) and
grazing incidence small angle neutron scattering (GISANS), we studied the
interface between hydrophobized silicon and heavy water before and after
saturation with nitrogen gas. Our specular reflectometry results can be
interpreted by assuming a sub-molecular sized depletion layer and the
off-specular measurements show no change with nitrogen super saturated water.
This picture is consistent with the assumption that, following the solvent
exchange, no additional nanobubbles are introduced at significant
concentrations (if present at all). Furthermore, we discuss the results, in
terms of the maximum surface coverage of nanobubbles that could be present on
the hydrophobic surface compatibly with the sensitivity limit of these
techniques.


title: Colliding Decimetre Dust

abstract:
  Collisional evolution is a key process in planetesimal formation and
decimetre bodies play a key role in the different models. However, the outcome
of collisions between two dusty decimetre bodies has never been studied
experimentally. Therefore, we carried out microgravity collision experiments in
the Bremen drop tower. The agglomerates consist of quartz with irregularly
shaped micrometre-sized grains and the mean volume filling factor is 0.437
$\pm$ 0.004. The aggregates are cylindrical with 12 cm in height and 12 cm in
diameter and typcial masses are 1.5 kg. These are the largest and most massive
dust aggregates studied in collisions to date. We observed rebound and
fragmentation but no sticking in the velocity range between 0.8 and 25.7 cm
s$^{-1}$. The critical fragmentation velocity for split up of an aggregate is
16.2 $\pm$ 0.4 cm s$^{-1}$. At lower velocities the aggregates bounce of each
other. In this velocity range the coefficient of restitution decreases with
increasing collision velocity from 0.8 to 0.3. While the aggregates are very
weak the critical specific kinetic energy for fragmentation $Q_{\mu =1}$ is a
factor 6 larger than expected. Collisions of large bodies in protoplanetary
discs are supposed to be much faster and the generation of smaller fragments is
likely. In planetary rings collision velocities are of the order of a few cm
s$^{-1}$ and are thereby in the same range investigated in these experiments.
The coefficient of restitution of dust agglomerates and regolith covered ice
particles, which are common in planetary rings, are similar.


title: Modulation Coding for Flash Memories

abstract:
  The aggressive scaling down of flash memories has threatened data reliability
since the scaling down of cell sizes gives rise to more serious degradation
mechanisms such as cell-to-cell interference and lateral charge spreading. The
effect of these mechanisms has pattern dependency and some data patterns are
more vulnerable than other ones. In this paper, we will categorize data
patterns taking into account degradation mechanisms and pattern dependency. In
addition, we propose several modulation coding schemes to improve the data
reliability by transforming original vulnerable data patterns into more robust
ones.


title:
A Note on the Stability of Cable-in-Conduit Conductors with Current
  Dependent Power-Law Index

abstract:
  A new stability criterion for cable-in-conduit superconductors with power-law
current-voltage characteristic and current dependent power-law index,
$n=n(I_c)$ is given. After a short discussion of the power-law volt-ampere
characteristic, different models of stability are discussed with special stress
on the differences to the older stability models. A typical stability case, the
extended cryostability is analyzed in detail. This model is characterized by a
smooth superconducting to normal transition and a power-law type heat
generation. The change in the helium temperature, typical for a
cable-in-conduit conductor, is included in the calculation. Finally, the
connection and interrelation aspects between the two common approximations of
the voltage-current characteristic of the technical superconductors, the
power-law and the exponential function are investigated. It is shown that the
exponential form is incompatible with the power-law form if the power-law index
is a function of temperature and magnetic field. An alternative exponential
form is proposed.


title: Average values of some Z-parameters in a random set partition

abstract:
  We find exact and asymptotic formulas for the average values of several
statistics on set partitions: of Carlitz's $q$-Stirling distributions, of the
numbers of crossings in linear and circular representations of set partitions,
of the numbers of overlappings and embracings, and of the numbers of
occurrences of a 2-pattern.


title:
Control of Stimulated Raman Scattering in the Strongly Nonlinear and
  Kinetic Regime Using Spike Trains of Uneven Duration and Delay: STUD Pulses

abstract:
  Stimulated Raman scattering (SRS) in its strongly nonlinear, kinetic regime
is controlled by a technique of deterministic, strong temporal modulation and
spatial scrambling of laser speckle patterns, called Spike Trains of Uneven
Duration and Delay (STUD pulses) [B. Afeyan and S. H\"uller, Phys. Rev. Lett.
(submitted)]. Kinetic simulations show that use of STUD pulses may decrease SRS
reflectivity by more than an order of magnitude over random-phase-plate (RPP)
or induced-spatial-incoherence (ISI) beams of the same average intensity and
comparable bandwidth.


title: Evolution and the Calcite Eye Lens

abstract:
  Calcite is a uniaxial, birefringent crystal, which in its optically
transparent form, has been used for animal eye lenses, the trilobite being one
such animal. Because of the calcite birefringence there is a difficulty in
using calcite as a lens. When the propagation direction of incoming light is
not exactly on the c-axis, the mages blur. In this paper, calcite blurring is
evaluated, and the non-blurring by a crystallin eye lens is compared to a
calcite one.


title:
High-Order Unstructured Lagrangian One-Step WENO Finite Volume Schemes
  for Non-Conservative Hyperbolic Systems: Applications to Compressible
  Multi-Phase Flows

abstract:
  In this article we present the first better than second order accurate
unstructured Lagrangian-type one-step WENO finite volume scheme for the
solution of hyperbolic partial differential equations with non-conservative
products. The method achieves high order of accuracy in space together with
essentially non-oscillatory behavior using a nonlinear WENO reconstruction
operator on unstructured triangular meshes. High order accuracy in time is
obtained via a local Lagrangian space-time Galerkin predictor method that
evolves the spatial reconstruction polynomials in time within each element. The
final one-step finite volume scheme is derived by integration over a moving
space-time control volume, where the non-conservative products are treated by a
path-conservative approach that defines the jump terms on the element
boundaries. The entire method is formulated as an Arbitrary-Lagrangian-Eulerian
(ALE) method, where the mesh velocity can be chosen independently of the fluid
velocity.
  The new scheme is applied to the full seven-equation Baer-Nunziato model of
compressible multi-phase flows in two space dimensions. The use of a Lagrangian
approach allows an excellent resolution of the solid contact and the resolution
of jumps in the volume fraction. The high order of accuracy of the scheme in
space and time is confirmed via a numerical convergence study. Finally, the
proposed method is also applied to a reduced version of the compressible
Baer-Nunziato model for the simulation of free surface water waves in moving
domains. In particular, the phenomenon of sloshing is studied in a moving water
tank and comparisons with experimental data are provided.


title: Weak local-global compatibility in the p-adic Langlands program for U(2)

abstract:
  Inspired by Emerton's work for GL(2), we study the completed cohomology of
the tower of finite sets associated with a definite unitary group in two
variables. When p splits (and other technical assumptions are fulfilled), we
show that the p-adic local Langlands correspondence for GL(2) (over Q_p) occurs
in the cohomology. We give an application to the Fontaine-Mazur conjecture over
CM fields.


title:
Remarks on the completeness of trajectories of accelerated particles in
  Riemannian manifolds and plane waves

abstract:
  Recently, classical results on completeness of trajectories of Hamiltonian
systems obtained at the beginning of the seventies, have been revisited,
improved and applied to Lorentzian Geometry. Our aim here is threefold: to give
explicit proofs of some technicalities in the background of the specialists, to
show that the introduced tools allow to obtain more results for the
completeness of the trajectories, and to apply these results to the
completeness of spacetimes that generalize classical plane and pp-waves.


title: Matching-Vector Families and LDCs Over Large Modulo

abstract:
  We prove new upper bounds on the size of families of vectors in $\Z_m^n$ with
restricted modular inner products, when $m$ is a large integer. More formally,
if $\vec{u}_1,\ldots,\vec{u}_t \in \Z_m^n$ and $\vec{v}_1,\ldots,\vec{v}_t \in
\Z_m^n$ satisfy $\langle\vec{u}_i,\vec{v}_i\rangle\equiv0\pmod m$ and
$\langle\vec{u}_i,\vec{v}_j\rangle\not\equiv0\pmod m$ for all $i\neq j\in[t]$,
we prove that $t \leq O(m^{n/2+8.47})$. This improves a recent bound of $t \leq
m^{n/2 + O(\log(m))}$ by \cite{BDL13} and is the best possible up to the
constant 8.47 when $m$ is sufficiently larger than $n$.
  The maximal size of such families, called `Matching-Vector families', shows
up in recent constructions of locally decodable error correcting codes (LDCs)
and determines the rate of the code. Using our result we are able to show that
these codes, called Matching-Vector codes, must have encoding length at least
$K^{19/18}$ for $K$-bit messages, regardless of their query complexity. This
improves a known super linear bound of $ K2^{\Omega({\sqrt{\log K}})}$ proved
in \cite{DGY11}.


title:
An investigation of the $K_{F}$-type Lorentz-Symmetry Breaking Gauge
  Models with Vortex-like Configurations

abstract:
  For the CPT-even case of the minimal Standard Model Extension, the
spin-projector method is adopted to account for the breaking (tensor) $% K_{\mu
\nu \kappa \lambda}$ term. We adopt a particular decomposition of this term in
fourvectors, and carry out a detailed analysis of causality and unitarity. From
this study, we are able to impose conditions on the decomposition of the
$K_{\mu \nu \kappa \lambda}$ and vortex formation is also investigated in
different situations.


title: Coding for Memory with Stuck-at Defects

abstract:
  In this paper, we propose an encoding scheme for partitioned linear block
codes (PLBC) which mask the stuck-at defects in memories. In addition, we
derive an upper bound and the estimate of the probability that masking fails.
Numerical results show that PLBC can efficiently mask the defects with the
proposed encoding scheme. Also, we show that our upper bound is very tight by
using numerical results.


title:
Detection of the electrostatic spin crossover effect in magnetic
  molecules

abstract:
  Scanning tunneling microscopy (STM) can be used to detect inelastic spin
transitions in magnetic nano-structures comprising only a handful of atoms.
Here we demonstrate that STM can uniquely identify the electrostatic spin
crossover effect, whereby the exchange interaction between two magnetic centers
in a magnetic molecule changes sign as a function of an external electric
field. The fingerprint of such effect is a large drop in the differential
conductance as the bias increases. Crucially in the case of a magnetic dimer
the spin crossover transition inverts the order between the ground state and
the first excited state, but does not change their symmetry. This means that at
both sides of the conductance drop associated to the spin crossover transition
there are two inelastic transition between the same states. The corresponding
conductance steps split identically in a magnetic field and provide a unique
way to identify the electrostatic spin crossover.


title:
Angular dependence and symmetry of Rashba spin torque in ferromagnetic
  heterostructures

abstract:
  In a ferromagnetic heterostructure, the interplay between a Rashba spin-orbit
coupling and an exchange field gives rise to a current-driven spin torque. In a
realistic device setup, we investigate the Rashba spin torque in the diffusive
regime and report two major findings: (i) a nonvanishing torque exists at the
edges of the device even when the magnetization and effective Rashba field are
aligned; (ii) anisotropic spin relaxation rates driven by the Rashba spin-orbit
coupling assign the spin torque a general expression ${\bm
T}=T^y_{\para}(\theta){\bm m}\times(\hat{\bm y}\times{\bm
m})+T^y_{\bot}(\theta)\hat{\bm y}\times{\bm m}+T^z_{\para}(\theta){\bm
m}\times(\hat{\bm z}\times{\bm m})+T^z_{\bot}(\theta)\hat{\bm z}\times{\bm m}$,
where the coefficients $T_{\para,\bot}^{y,z}$ depend on the magnetization
direction. Our results agree with recent experiments.


title:
Three-Dimensional Modelling of Ionized Gas. I. Did very massive stars of
  different metallicities drive the second cosmic reionization?

abstract:
  The first generation of stars that formed directly from the primordial gas
played a crucial role in the early phase of the reionization of the universe.
Because of the short lifetimes of these stars the metals produced in their
cores were quickly returned to the environment, from which early PopII stars
with a different initial mass function and different SEDs were formed, already
much earlier than the time at which the universe became completely reionized at
a redshift of z~6. Using a state-of-the-art model atmosphere code we calculate
realistic SEDs of very massive stars (VMSs) of different metallicities to serve
as input for the 3-dimensional multi-frequency radiative transfer code we have
developed to simulate the temporal evolution of the ionization of the
inhomogeneous interstellar and intergalactic medium, using multiple stellar
clusters as sources of ionizing radiation. Our tool handles distributions of
numerous radiative sources characterized by high resolution synthetic SEDs, and
yields occupation numbers of the required energy levels of the most important
elements which are treated in NLTE consistently with the 3d radiative transfer.
We further demonstrate that the increasing metallicity of the radiative sources
in the transition from PopIII stars to PopII stars has a strong impact on the
hardness of the emitted spectrum, and hence on the reionization history of
helium. A top-heavy stellar mass distribution characterized by VMSs forming in
chemically evolved clusters of high core mass density may not only provide the
progenitors of intermediate-mass and supermassive black holes (SMBHs), but also
play an important role for the reionization of HeII. The number of VMSs
required to reionize HeII by a redshift of z~2.5 is astonishingly close to the
number of VMSs required to explain galactic SMBHs if one assumes that these
have been formed by mergers of smaller black holes.


title: Pulsars and magnetars

abstract:
  The high-energy sources known as anomalous X-ray pulsars (AXPs) and soft
gamma-ray repeaters (SGRs) are well explained as magnetars: isolated neutron
stars powered by their own magnetic energy. After explaining why it is
generally believed that the traditional energy sources at work in other neutron
stars (accretion, rotation, residual heat) cannot power the emission of
AXPs/SGRs, I review the observational properties of the twenty AXPs/SGRs
currently known and describe the main features of the magnetar model. In the
last part of this review I discuss the recent discovery of magnetars with low
external dipole field and some of the relations between AXPs/SGRs and other
classes of isolated neutron stars.