title:
Towards a Taxonomy of Performance Evaluation of Commercial Cloud
  Services

abstract:
  Cloud Computing, as one of the most promising computing paradigms, has become
increasingly accepted in industry. Numerous commercial providers have started
to supply public Cloud services, and corresponding performance evaluation is
then inevitably required for Cloud provider selection or cost-benefit analysis.
Unfortunately, inaccurate and confusing evaluation implementations can be often
seen in the context of commercial Cloud Computing, which could severely
interfere and spoil evaluation-related comprehension and communication. This
paper introduces a taxonomy to help profile and standardize the details of
performance evaluation of commercial Cloud services. Through a systematic
literature review, we constructed the taxonomy along two dimensions by
arranging the atomic elements of Cloud-related performance evaluation. As such,
this proposed taxonomy can be employed both to analyze existing evaluation
practices through decomposition into elements and to design new experiments
through composing elements for evaluating performance of commercial Cloud
services. Moreover, through smooth expansion, we can continually adapt this
taxonomy to the more general area of evaluation of Cloud Computing.


title: Variance of operators and derivations

abstract:
  The variance of a bounded linear operator $a$ on a Hilbert space $H$ at a
unit vector $h$ is defined by $D_h(a)=\|ah\|^2-|<ah,h>|^2$. We show that two
operators $a$ and $b$ have the same variance at all vectors $h\in H$ if and
only if there exist scalars $\sigma,\lambda$ with $|\sigma|=1$ such that
$b=\sigma a+\lambda1$ or $a$ is normal and $b=\sigma a^*+\lambda1$. Further, if
$a$ is normal, then the inequality $D_h(b)\leq\kappa D_h(a)$ holds for some
constant $\kappa$ and all unit vectors $h$ if and only if $b=f(a)$ for a
Lipschitz function $f$ on the spectrum of $a$. Variants of these results for
C$^*$-algebras are also proved.
  We also study the related, but more restrictive inequalities $\|bx-xb\|\leq
\|ax-xa\|$ supposed to hold for all $x\in B(H)$ or for all $x\in B(H^n)$ and
all positive integers $n$. We consider the connection between such inequalities
and the range inclusion $d_b(B(H))\subseteq d_a(B(H))$, where $d_a$ and $d_b$
are the derivations on $B(H)$ induced by $a$ and $b$. If $a$ is subnormal, we
study these conditions in particular in the case when $b$ is of the form
$b=f(a)$ for a function $f$.


title: Entanglement entropy for a particle coupled with its surrounding

abstract:
  We investigate the entanglement for a model of a particle moving in the
lattice (many-body system). The interaction between the particle and the
lattice is modelled using Hooke's law. The Feynman path integral approach is
applied to compute the density matrix of the system. The complexity of the
problem is reduced by considering two-body system (bipartite system). The
spatial entanglement of ground state is studied using the linear entropy. We
find that increasing the confining potential implies a large spatial separation
between the two particles. Thus the interaction between the particles increases
according to Hooke's law. This results in the increase in the spatial
entanglement.

categories: math-ph cond-mat.stat-mech math.MP quant-ph


title:
Electronic structure, phonon spectra and electron-phonon interaction in
  HfB2

abstract:
  The electronic structure, Fermi surface, angle dependence of the cyclotron
masses and extremal cross sections of the Fermi surface, phonon spectra,
electron-phonon Eliashberg and transport spectral functions, temperature
dependence of electrical resistivity of the HfB2 diboride were investigated
from first principles using the fully relativistic and full potential linear
muffin-tin orbital methods. The calculations of the dynamic matrix were carried
out within the framework of the linear response theory. A good agreement with
experimental data of electron-phonon spectral functions, electrical
resistivity, cyclotron masses and extremal cross sections of the Fermi surface
was achieved.


title:
Initial stresses in elastic solids: Constitutive laws and
  acoustoelasticity

abstract:
  On the basis of the nonlinear theory of elasticity, the general constitutive
equation for an isotropic hyperelastic solid in the presence of initial stress
is derived. This derivation involves invariants that couple the deformation
with the initial stress and in general, for a compressible material, it
requires 10 invariants, reducing to 9 for an incompressible material.
Expressions for the Cauchy and nominal stress tensors in a finitely deformed
configuration are given along with the elasticity tensor and its specialization
to the initially stressed undeformed configuration. The equations governing
infinitesimal motions superimposed on a finite deformation are then used to
study the combined effects of initial stress and finite deformation on the
propagation of homogeneous plane waves in a homogeneously deformed and
initially stressed solid of infinite extent. This general framework allows for
various different specializations, which make contact with earlier works. In
particular, connections with results derived within Biot's classical theory are
highlighted. The general results are also specialized to the case of a small
initial stress and a small pre-deformation, i.e. to the evaluation of the
acoustoelastic effect. Here the formulas derived for the wave speeds cover the
case of a second-order elastic solid without initial stress and subject to a
uniaxial tension [Hughes and Kelly, Phys. Rev. 92 (1953) 1145] and are
consistent with results for an undeformed solid subject to a residual stress
[Man and Lu, J. Elasticity 17 (1987) 159]. These formulas provide a basis for
acoustic evaluation of the second- and third-order elasticity constants and of
the residual stresses. The results are further illustrated in respect of a
prototype model of nonlinear elasticity with initial stress, allowing for both
finite deformation and nonlinear dependence on the initial stress.


title: Molecular dynamics modeling of self-diffusion along a triple junction

abstract:
  We propose a computational procedure for creating a stable equilibrium triple
junction (TJ) with controlled grain misorientations. We apply this procedure to
construct a TJ between a {\Sigma}5(210) grain boundary (GB) and two general
high-angle GBs in copper, and calculate the diffusion coefficients along the TJ
and the GBs using molecular dynamics with an embedded-atom potential. The TJ
diffusion is only a factor of two faster than diffusion in the {\Sigma}5 GB but
significantly faster than diffusion in the general GBs. Both the GBs and the TJ
studied here show a premelting behavior near the bulk melting point, where
their diffusivities converge to the diffusivity of bulk liquid. Although our
results are consistent with the common assumption that TJ diffusion is
generally faster than GB diffusion, the difference between the two
diffusivities does not appear to be large enough to ensure a significant
contribution of TJs to diffusional creep in polycrystals at high temperatures.


title:
Ultralow Phase Noise Microwave Generation From Mode-Locked Er-Fiber
  Lasers With Subfemtosecond Integrated Timing Jitter

abstract:
  We demonstrate ultralow phase noise 10-GHz microwave signal generation from a
free-running mode-locked Er-fiber laser with -142 and -157 dBc/Hz
single-sideband absolute phase noise at 10- and 100-kHz offset frequencies,
respectively. The absolute RMS timing jitter is 1.5 fs when integrated from
1-kHz to 5-GHz (Nyquist frequency) offset frequency. In the 10-kHz to 10-MHz
integration bandwidth typically used for microwave generators, the RMS
integrated jitter is 0.49 fs. The Er-fiber laser is operated in the
stretched-pulse regime at close-to-zero dispersion to minimize the phase noise
of extracted microwaves. In order to suppress the excess phase noise in the
optical-to-electronic conversion process, we synchronize a low-noise
voltage-controlled oscillator to the fiber laser using a fiber
Sagnac-loop-based optical-microwave phase detector.


title:
Investigation on the critical dynamics of real magnetics models by
  computational physics methods

abstract:
  The critical dynamics of classical 3D Heisenberg model and complex model of
the real antiferromagnetic Cr2O3 is investigated with use of the method of
molecular dynamics. The dynamic critical exponent z are determined for these
models on the basis of the theory dynamic finite-size scaling.


title:
Variance optimal hedging for continuous time additive processes and
  applications

abstract:
  For a large class of vanilla contingent claims, we establish an explicit
F\"ollmer-Schweizer decomposition when the underlying is an exponential of an
additive process. This allows to provide an efficient algorithm for solving the
mean variance hedging problem. Applications to models derived from the
electricity market are performed.


title:
A three point formula for finding roots of equations by the method of
  least squares

abstract:
  A new method of root finding is formulated that uses a numerical iterative
process involving three points. A given function y = f(x) whose roots are
desired is fitted and approximated by a polynomial function of the form P(x)=
a(x-b)^N that passes between three equi-spaced points using the method of least
squares. Successive iterations using the same procedure of curve fitting is
used to locate the root within a given level of tolerance. The power N of the
curve suitable for a given function form can be appropriately varied at each
step of the iteration to give a faster rate of convergence and avoid cases
where oscillation, divergence or off shooting to an invalid domain may be
encountered. An estimate of the rate of convergence is provided. It is shown
that the method has a quadratic convergence similar to that of Newton's method.
Examples are provided showing the procedure as well as comparison of the rate
of convergence with the secant and Newton methods. The method does not require
evaluation of function derivatives.


title:
The role of disorder symmetry in a dirty superconductor: a
  Bogoliubov-deGennes (BdG) study

abstract:
  We study the effect of disorder symmetry in a disordered s-wave
superconductor. We begin with an attractive Hubbard model on a two-dimensional
square lattice in the presence of diagonal- and off-diagonal disorder. The
model is studied numerically using Bogoliubov-deGennes mean-field approach. We
find that the off-diagonal disorder is much more efficient in destroying
superconducting order. A detailed analysis brings out very distinct qualitative
pictures in the two cases: diagonal disorder leads to formation of small scale
isolated superconducting islands separated by large region of normal metal,
whereas off-diagonal disorder leads to a connected network of superconducting
region. Naively, it seems that the connected network of superconducting regions
should have a large average value for superconducting order parameter, but this
does not hold true for large disorder, as we demonstrate explicitly. Our
qualititive picture is supported by real-space data on local order parameters.


title: (q,t)-hook formula for Birds and Banners

abstract:
  We study Okada's conjecture on $(q,t)$-hook formula of general $d$-complete
posets. Proctor classified $d$-complete posets into 15 irreducible ones. We try
to give a case-by-case proof of Okada's $(q,t)$-hook formula conjecture using
the symmetric functions. Here we give a proof of the conjecture for birds and
banners, in which we use Gasper's identity for VWP-series ${}_{12}W_{11}$.


title: Joint estimation of multiple related biological networks

abstract:
  Graphical models are widely used to make inferences concerning interplay in
multivariate systems. In many applications, data are collected from multiple
related but nonidentical units whose underlying networks may differ but are
likely to share features. Here we present a hierarchical Bayesian formulation
for joint estimation of multiple networks in this nonidentically distributed
setting. The approach is general: given a suitable class of graphical models,
it uses an exchangeability assumption on networks to provide a corresponding
joint formulation. Motivated by emerging experimental designs in molecular
biology, we focus on time-course data with interventions, using dynamic
Bayesian networks as the graphical models. We introduce a computationally
efficient, deterministic algorithm for exact joint inference in this setting.
We provide an upper bound on the gains that joint estimation offers relative to
separate estimation for each network and empirical results that support and
extend the theory, including an extensive simulation study and an application
to proteomic data from human cancer cell lines. Finally, we describe
approximations that are still more computationally efficient than the exact
algorithm and that also demonstrate good empirical performance.


title:
Systematic properties of the Tsallis Distribution: Energy Dependence of
  Parameters in High-Energy p-p Collisions

abstract:
  Changes in the transverse momentum distributions with beam energy are studied
using the Tsallis distribution as a parameterization. The dependence of the
Tsallis parameters q, T and the volume are determined as a function of beam
energy. The Tsallis parameter q shows a weak but clear increase with beam
energy with the highest value being approximately 1.15. The Tsallis temperature
and volume are consistent with being independent of beam energy within
experimental uncertainties.


title: A fuzzy similarity based approach for intelligent web based e-learning

abstract:
  In this paper, an intelligent system for web based e-Learning is proposed
which analyzes students knowledge capacity by applying clustering technique.
This system uses fuzzy logic and k-means clustering algorithm to arrange the
documents according to the level of their performance. Moreover, a new domain
ontology alignment technique is proposed that uses contextual information of
the knowledge sources from the e-Learning domain for effective decision making.
The proposed ontology alignment method has been empirically tested in an
e-Learning environment and the experimental results show that the proposed
method performs better than the existing methods in terms of precision and
recall. The salient contributions of this paper are the use of Jaccard
Similarity, fuzzy approach for ontology alignment and K-Means clustering
algorithm for decision making using decision rules for providing intelligent
e-Learning.


title: Entropy evolution of universes with initial and final de Sitter eras

abstract:
  This brief report studies the behavior of entropy in two recent models of
cosmic evolution by J.A.S. Lima, S. Basilakos, and F.E.M. Costa [Phys. Rev. D
\underline{86}, 103534 (2012)], and J. A. S. Lima, S. Basilakos, and J.
Sol\'{a} [arXiv:1209.2802]. Both start with an initial de Sitter expansion, go
through the conventional radiation and matter dominated eras to be followed by
a final and everlasting de Sitter expansion. In spite of their outward
similarities (from the observational viewpoint they are arbitrary close to the
conventional $\Lambda$CDM model), they deeply differ in the physics behind
them. Our study reveals that in both cases the universe approaches
thermodynamic equilibrium in the last de Sitter era in the sense that the
entropy of the apparent horizon plus that of matter and radiation inside it
increases and is concave. Accordingly, they are consistent with thermodynamics.
Cosmological models that do not approach equilibrium at the last phase of their
evolution appear in conflict with the second law of thermodynamics.


title: The L-sectional curvature of S-manifolds

abstract:
  We investigate L-sectional curvature of S-manifolds with respect to the
Rieman- nian connection and to certain semi-symmetric metric and non-metric
connections naturally related with the structure, obtaining conditions for them
to be constant and giving examples of S-manifolds in such conditions. Moreover,
we calculate the scalar curvature in all the cases.


title:
On feasibility, stability and performance in distributed model
  predictive control

abstract:
  In distributed model predictive control (DMPC), where a centralized
optimization problem is solved in distributed fashion using dual decomposition,
it is important to keep the number of iterations in the solution algorithm,
i.e. the amount of communication between subsystems, as small as possible. At
the same time, the number of iterations must be enough to give a feasible
solution to the optimization problem and to guarantee stability of the closed
loop system. In this paper, a stopping condition to the distributed
optimization algorithm that guarantees these properties, is presented. The
stopping condition is based on two theoretical contributions. First, since the
optimization problem is solved using dual decomposition, standard techniques to
prove stability in model predictive control (MPC), i.e. with a terminal cost
and a terminal constraint set that involve all state variables, do not apply.
For the case without a terminal cost or a terminal constraint set, we present a
new method to quantify the control horizon needed to ensure stability and a
prespecified performance. Second, the stopping condition is based on a novel
adaptive constraint tightening approach. Using this adaptive constraint
tightening approach, we guarantee that a primal feasible solution to the
optimization problem is found and that closed loop stability and performance is
obtained. Numerical examples show that the number of iterations needed to
guarantee feasibility of the optimization problem, stability and a prespecified
performance of the closed-loop system can be reduced significantly using the
proposed stopping condition.


title: Construction of Lumps with nontrivial interaction

abstract:
  We develop a method based upon the Singular Manifold Method that yields an
iterative and analytic procedure to construct solutions for a
Bogoyavlenskii-Kadomtsev-Petviashvili equation. This method allows us to
construct a rich collection of lump solutions with a nontrivial evolution
behavior


title: Raman and non Raman EIT resonances in a degenerate four level system

abstract:
  We study coherence effects in an atom having three metastable levels and
single life-time broadened upper state. Two laser fields couple ground states
to an excited one and an radio-frequency (rf) field operates between ground
state levels. We consider the case when the common level for the rf-field and
one of the laser field (to which we refer as the probing field) transitions is
twice degenerate. We predict a novel type of dark states (we call them non
Raman dark states), which in contrary to Raman resonances, do not require the
fulfillment of the two-photon resonance condition. We realize the configuration
in the atomic hydrogen and show that non Raman resonances are determined by the
geometry of the rf and probing field's polarizations. For ultra-cold atoms non
Raman resonances arise when the polarization vectors of the fields are parallel
or perpendicular to each other. For an atomic gas at room temperatures
electromagnetically induced transparency (EIT) resonances associated with Raman
and non Raman dark states are studied by taking into account spin-exchange
relaxation in the ground state of the hydrogen atom. We establish properties of
non Raman dark states by investigating the relation of EIT resonances to the
polarization geometry.


title:
Gravitational instabilities of isothermal spheres in the presence of a
  cosmological constant

abstract:
  Gravitational instabilities of isothermal spheres are studied in the presence
of a positive or negative cosmological constant, in the Newtonian limit. In
gravity, the statistical ensembles are not equivalent. We perform the analysis
both in the microcanonical and the canonical ensembles, for which the
corresponding instabilities are known as `gravothermal catastrophe' and
`isothermal collapse', respectively. In the microcanonical ensemble, no
equilibria can be found for radii larger than a critical value, which is
increasing with increasing cosmological constant. In contrast, in the canonical
ensemble, no equilibria can be found for radii smaller than a critical value,
which is decreasing with increasing cosmological constant. For a positive
cosmological constant, characteristic reentrant behaviour is observed.


title: Applications of Convex Analysis within Mathematics

abstract:
  In this paper, we study convex analysis and its theoretical applications. We
first apply important tools of convex analysis to Optimization and to Analysis.
We then show various deep applications of convex analysis and especially
infimal convolution in Monotone Operator Theory. Among other things, we
recapture the Minty surjectivity theorem in Hilbert space, and present a new
proof of the sum theorem in reflexive spaces. More technically, we also discuss
autoconjugate representers for maximally monotone operators. Finally, we
consider various other applications in mathematical analysis.


title: Open--constructible functions

abstract:
  We prove that if a continuous function $f : X \to f(X)$ takes open sets into
elements of the Boolean algebra generated by open and closed subsets in $f(X)$,
then there exist
  $X_n \subset X,$ $(n \in \omega)$ such that $f$ is open on every $X_n$ and
$f(X_n)$ cover $ f(X).$


title:
Uniform asymptotic stability of solutions of fractional functional
  differential equations

abstract:
  In this paper, some global existence and uniform asymptotic stability results
for fractional functional differential equations are proved. It is worthy
mentioning that when $\alpha=1$ the initial value problem (1.1) reduces to a
classical dissipative differential equation with delays in [4]


title:
Isotopic distribution of fission fragments in collisions between 238U
  beam and 9Be and 12C targets at 24 MeV/u

abstract:
  Inverse kinematics coupled to a high-resolution spectrometer is used to
investigate the isotopic yields of fission fragments produced in reactions
between a 238U beam at 24 MeV/u and 9Be and 12C targets. Mass, atomic number
and isotopic distributions are reported for the two reactions. These
informations give access to the neutron excess and the isotopic distribution
widths, which together with the atomic-number and mass distributions are used
to investigate the fusion-fission dynamics.


title: In situ visualization of Ni-Nb bulk metallic glasses phase transition

abstract:
  We report the results of the Ni-based bulk metallic glass structural
evolution and crystallization behavior in situ investigation. The X-ray
diffraction (XRD), transmission electron microscopy (TEM), nano-beam
diffraction (NBD), differential scanning calorimetry (DSC), radial distribution
function (RDF) and scanning probe microscopy/spectroscopy (STM/STS) techniques
were applied to analyze the structure and electronic properties of Ni63.5Nb36.5
glasses before and after crystallization. It was proved that partial surface
crystallization of Ni63.5Nb36.5 can occur at the temperature lower than for the
full sample crystallization. According to our STM measurements the primary
crystallization is originally starting with the Ni3Nb phase formation. It was
shown that surface crystallization drastically differs from the bulk
crystallization due to the possible surface reconstruction. The mechanism of
Ni63.5Nb36.5 glass alloy 2D-crystallization was suggested, which corresponds to
the local metastable (3x3)-Ni(111) surface phase formation. The possibility of
different surface nano-structures development by the annealing of the
originally glassy alloy in ultra high vacuum at the temperature lower, than the
crystallization temperature was shown. The increase of mean square surface
roughness parameter Rq while moving from glassy to fully crystallized state can
be caused by concurrent growth of Ni3Nb and Ni6Nb7 bulk phases. The simple
empirical model for the estimation of Ni63.5Nb36.5 cluster size was suggested,
and the obtained values (7.64 A, 8.08 A) are in good agreement with STM
measurements data (8 A-10 A).


title: All spin-2 cubic vertices with two derivatives

abstract:
  In this paper we provide a complete list of spin-2 cubic interaction vertices
with two derivatives. We work in (anti) de Sitter space with dimension d >= 4
and arbitrary value of cosmological constant and use simple metric formalism
without any auxiliary or Stueckelberg fields. We separately consider cases with
one, two and three different spin-2 fields entering the vertex where each field
may be massive, massless or partially massless one. The connection of our
results with massive (bi)gravity theories is also briefly discussed.


title: Symplectic capacities of Hermitian symmetric spaces

abstract:
  Inspired by the work of G. Lu on pseudo symplectic capacities we obtain
several results on the Gromov width and the Hofer--Zehnder capacity of
Hermitian symmetric spaces of compact type. Our results and proofs extend those
obtained by Lu for complex Grassmannians to Hermitian symmetric spaces of
compact type. We also compute the Gromov width and the Hofer--Zehnder capacity
for Cartan domains and their products.


title: Comparison of quantum and classical relaxation in spin dynamics

abstract:
  The classical Landau-Lifshitz equation with damping term has been derived
from the time evolution of a quantum mechanical wave function under the
assumption of a non-hermitian Hamilton operator. Further, the trajectory of a
classical spin $\mathrm{S}$ has been compared with the expectation value of the
spin operator $\mathrm{\hat{S}}$. A good agreement between classical and
quantum mechanical trajectories can be found for Hamiltonians linear in
$\mathrm{\hat{S}}$ respectively $\mathrm{S}$. Quadratic or higher order terms
in the Hamiltonian result in a disagreement.


title: Method for solving an iterative functional equation $A^{2^n}(x)=F(x)$

abstract:
  Using the notion of the composita, we obtain a method of solving iterative
functional equations of the form $A^{2^n}(x)=F(x)$, where $F(x)=\sum_{n>0}
f(n)x^n$, $f(1)\neq 0$. We prove that if $F(x)=\sum_{n>0} f(n)x^n$ has integer
coefficients, then the generating function $A(x)=\sum_{n>0}a(n)x^n$, which is
obtained from the iterative functional equation $4A(A(x))=F(4x)$, has integer
coefficients.
  Key words: iterative functional equation, composition of generating
functions, composita.


title: OpenSPIM - an open access platform for light sheet microscopy

abstract:
  Light sheet microscopy promises to revolutionize developmental biology by
enabling live in toto imaging of entire embryos with minimal phototoxicity. We
present detailed instructions for building a compact and customizable Selective
Plane Illumination Microscopy (SPIM) system. The integrated OpenSPIM hardware
and software platform is shared with the scientific community through a public
website, thereby making light sheet microscopy accessible for widespread use
and optimization to various applications.


title:
Two-, three-, and four-photon ionization of Mg in the circularly and
  linearly polarized laser fields: Comparative study using the Hartree-Fock and
  model potentials

abstract:
  We theoretically study multiphoton ionization of Mg in the circularly as well
as the linearly polarized laser fields. Specifically two-, three-, and
four-photon ionization cross sections from the ground and first excited states
are calculated as a function of photon energy. Calculations are performed using
the frozen-core Hartree-Fock and also the model potential approaches and the
results are compared. We find that the model potential approach provide results
as good as or even slightly better than those by the frozen-core Hartree-Fock
approach. We also report the relative ratios of the ionization cross sections
by the circularly and linearly polarized laser fields as a function of photon
energy, which exhibit clear effects of electron correlations.


title: Heterotic Mini-landscape in blow-up

abstract:
  Localization properties of fields in compact extra dimensions are crucial
ingredients for string model building, particularly in the framework of
orbifold compactifications. Realistic models often require a slight deviation
from the orbifold point, that can be analyzed using field theoretic methods
considering (singlet) fields with nontrivial vacuum expectation values. Some of
these fields correspond to blow-up modes that represent the resolution of
orbifold singularities. Improving on previous analyses we give here an explicit
example of the blow-up of a model from the heterotic Mini-landscape. An exact
identification of the blow-up modes at various fixed points and fixed tori with
orbifold twisted fields is given. We match the massless spectra and identify
the blow-up modes as non-universal axions of compactified string theory. We
stress the important role of the Green-Schwarz anomaly polynomial for the
description of the resolution of orbifold singularities.


title: Hot and Dense Hadron Gas (HG): A New Excluded-volume approach

abstract:
  We formulate a thermodynamically consistent equation of state (EOS), based on
excluded-volume approach, for a hot, dense hadron gas (HG). We calculate
various thermodynamical quantities of HG and various hadron ratios and compare
our model results with the results of other excluded-volume models and
experimental data. We also calculate various transport coefficients such as
$\eta/s$ etc. and compare them with other HG model results. Furthermore, we
test the validity of our model in getting the rapidity spectra of various
hadrons and the effect of flow on them is investigated by matching our
predictions with the experimental data.


title: QCD Phase Transition in a new Hybrid Model Formulation

abstract:
  Search of a proper and realistic equations of state (EOS) for strongly
interacting matter used in the study of QCD phase diagram still appears as a
challenging task. Recently, we have constructed a hybrid model description for
the quark gluon plasma (QGP) as well as hadron gas (HG) phases where we use a
new excluded-volume model for HG and a thermodynamically-consistent
quasiparticle model for the QGP phase. We attempt to use them to get a QCD
phase boundary and a critical point. We test our hybrid model by reproducing
the entire lattice QCD data for strongly interacting matter at zero baryon
chemical potential ($\mu_{B}$)and predict the results at finite $\mu_{B}$ and
$T$.


title:
Pygmy and giant electric dipole responses of medium-heavy nuclei in a
  self-consistent Random Phase Approximation approach with finite-range
  interaction

abstract:
  The pygmy dipole resonance (PDR) is studied in various medium-heavy nuclei by
using a Gogny interaction in a self-consistent Hartree-Fock plus Random Phase
Approximation method. We compare the details of the PDR structure with those of
the giant dipole resonance (GDR). In the PDR protons and neutrons vibrate in
phase, and the main contributions are given by particle-hole excitations
involving the neutrons in excess. On the contrary, in the GDR protons and
neutrons vibrate out of phase, and all the nucleons are involved in the
excitation. The values of the parameters we used to define the collectivity of
an excitation indicate that the PDR is less collective than the GDR. We also
investigate the role of the residual interaction in the appearance of the PDR
and we find a subtle interplay with the shell structure of the nucleus.


title:
Improved Polyakov-loop potential for effective models from functional
  calculations

abstract:
  We investigate the quark backreaction on the Polyakov loop and its impact on
the thermodynamics of quantum chromodynamics. The dynamics of the gluons
generating the Polyakov-loop potential is altered by the presence of dynamical
quarks. However, this backreaction of the quarks has not yet been taken into
account in Polyakov-loop extended model studies. In the present work, we show
within a 2+1 flavour Polyakov-quark-meson model that a quark-improved
Polyakov-loop potential leads to a smoother transition between the
low-temperature hadronic phase and the high-temperature quark-gluon plasma
phase. In particular, we discuss the dependence of our results on the remaining
uncertainties that are the critical temperature and the parametrisation of the
Polyakov-loop potential as well as the mass of the sigma-meson.


title:
Metal-insulator transition and phase separation in doped AA-stacked
  graphene bilayers

abstract:
  We investigate the doping of AA-stacked graphene bilayers. Applying a mean
field theory at zero temperature we find that, at half-filling, the bilayer is
an antiferromagnetic insulator. Upon doping, the homogeneous phase becomes
unstable with respect to phase separation. The separated phases are an undoped
antiferromagnetic insulator and a metal with a non-zero concentration of charge
carriers. At sufficiently high doping, the insulating areas shrink and
disappear, and the system becomes a homogeneous metal. The conductivity changes
drastically upon doping, so the bilayer may be used as a switch in electronic
devices. The effects of finite temperature are also discussed.


title: On the Feichtinger Conjecture

abstract:
  We prove the Feichtinger Conjecture for a class of Bessel sequences of unit
norm vectors in a Hilbert space. Also, we prove that every Bessel sequence of
unit vectors in a Hilbert space can be partitioned into finitely many uniformly
separated sequences.


title: Penning ionization of doped helium nanodroplets following EUV excitation

abstract:
  Helium nanodroplets are widely used as a cold, weakly interacting matrix for
spectroscopy of embedded species. In this work we excite or ionize doped He
droplets using synchrotron radiation and study the effect onto the dopant atoms
depending on their location inside the droplets (rare gases) or outside at the
droplet surface (alkali metals). Using photoelectron-photoion coincidence
imaging spectroscopy at variable photon energies (20-25 eV), we compare the
rates of charge-transfer to Penning ionization of the dopants in the two cases.
The surprising finding is that alkali metals, in contrast to the rare gases,
are efficiently Penning ionized upon excitation of the (n=2)-bands of the host
droplets. This indicates rapid migration of the excitation to the droplet
surface, followed by relaxation, and eventually energy transfer to the alkali
dopants.


title: A Computed Room Temperature Line List for Phosphine

abstract:
  An accurate and comprehensive room temperature rotation-vibration transition
line list for phosphine (31PH3) is computed using a newly refined potential
energy surface and a previously constructed ab initio electric dipole moment
surface. Energy levels, Einstein A coefficients and transition intensities are
computed using these surfaces and a variational approach to the nuclear motion
problem as implemented in the program TROVE. A ro-vibrational spectrum is
computed, covering the wavenumber range 0 to 8000 cm-1. The resulting line
list, which is appropriate for temperatures up to 300 K, consists of a total of
137 million transitions between 5.6 million energy levels. Several of the band
centres are shifted to better match experimental transition frequencies. The
line list is compared to the most recent HITRAN database and other laboratorial
sources. Transition wavelengths and intensities are generally found to be in
good agreement with the existing experimental data, with particularly close
agreement for the rotational spectrum. An analysis of the comparison between
the theoretical data created and the existing experimental data is performed,
and suggestions for future improvements and assignments to the HITRAN database
are made.


title:
UVCS/SoHO Catalog of Coronal Mass Ejections from 1996 to 2005:
  Spectroscopic Proprieties

abstract:
  Ultraviolet spectra of the extended solar corona have been routinely obtained
by SoHO/UVCS since 1996. Sudden variations of spectral parameters are mainly
due to the detection of Coronal Mass Ejections (CMEs) crossing the instrumental
slit. We present a catalog of CME ultraviolet spectra based upon a systematic
search of events in the LASCO CME catalog, and we discuss their statistical
properties. Our catalog includes 1059 events through the end of 2005, covering
nearly a full solar cycle. It is online available at the URL
http://solarweb.oato.inaf.it/UVCS_CME and embedded in the online LASCO CME
catalog (http://cdaw.gsfc.nasa.gov/CME_list). The emission lines observed
provide diagnostics of CME plasma parameters, such as the light-of-sight
velocity, density and temperature and allow to link the CME onset data to the
extended corona white-light images. The catalog indicates whether there are
clear signatures of features such as shock waves, current sheets, O VI flares,
helical motions and which part of the CME structures (front, cavity or
prominence material) are detected. The most common detected structure is the
cool prominence material (in about 70% of the events). For each event, the
catalog also contains movie, images, plots and information relevant to address
detailed scientific investigations. The number of events detected in UV is
about 1/10 of the LASCO CMEs, and about 1/4 of the halo events. We find that
UVCS tends to detect faster, more massive and energetic CME than LASCO and for
about 40% of the events events it has been possible to determine the plasma
light-of-sight velocity.


title: Asymptotics for the Late Arrivals Problem

abstract:
  We study a discrete time queueing system where deterministic arrivals have
i.i.d. exponential delays $\xi_{i}$. The standard deviation $\sigma$ of the
delay is finite, but its value is much larger than the deterministic unit
service time. We describe the model as a bivariate Markov chain, we prove that
it is ergodic and then we focus on the unique joint equilibrium distribution.
We write a functional equation for the bivariate generating function, finding
the solution of such equation on a subset of its set of definition. This
solution allows us to prove that the equilibrium distribution of the Markov
chain decays super-exponentially fast in the quarter plane. Finally, exploiting
the latter result, we discuss the numerical computation of the stationary
distribution, showing the effectiveness of a simple approximation scheme in a
wide region of the parameters. The model, motivated by air and railway traffic,
was proposed many decades ago by Kendall with the name of "late arrivals
problem", but no solution has been found so far.


title: The Evolution of Active Galactic Nuclei in Warm Dark Matter Cosmology

abstract:
  Recent measurements of the abundance of AGN with low-luminosities (L_X< 10^44
erg/s in the 2-10 keV energy band) at high redshifts z>4 provide a serious
challenge for Cold Dark Matter (CDM) models based on interaction-driven fueling
of AGN. Using a semi-analytic model of galaxy formation we investigate how such
observations fit in a Warm Dark Matter (WDM) scenario of galaxy formation, and
compare the results with those obtained in the standard CDM scenario with
different efficiencies for the stellar feedback. Taking on our previous
exploration of galaxy formation in WDM cosmology, we assume as a reference case
a spectrum which is suppressed - compared to the standard CDM case - below a
cut-off scale ~ 0.2$ Mpc corresponding (for thermal relic WDM particles) to a
mass m_X=0.75 keV. We run our fiducial semi-analytic model with such a WDM
spectrum to derive AGN luminosity functions from z~6 to the present over a wide
range of luminosities (10^43< L_X/erg/s < 10^46 in the 2-10 keV X-ray band), to
compare with recent observations and with the results in the CDM case. When
compared with the standard CDM case, the luminosity distributions we obtain
assuming a WDM spectrum are characterized by a similar behaviour at low
redshift, and by a flatter slope at faint magnitudes for z>3, which provide an
excellent fit to present observations. We discuss how such a result compares
with CDM models with maximized feedback efficiency, and how future deep AGN
surveys will allow for a better discrimination between feedback and
cosmological effects on the evolution of AGN in interaction-driven models for
AGN fueling.


title:
Agreement of Neutrino Deep Inelastic Scattering Data with Global Fits of
  Parton Distributions

abstract:
  The compatibility of neutrino-nucleus deep inelastic scattering data within
the universal, factorizable nuclear parton distribution functions has been
studied independently by several groups in the past few years. The conclusions
are contradictory, ranging from a violation of the universality up to a good
agreement, most of the controversy originating from the use of the
neutrino-nucleus data from the NuTeV Collaboration. Here, we pay attention to
non-negligible differences in the absolute normalization between different
neutrino data sets. We find that such variations are large enough to prevent a
tensionless fit to all data simultaneously and could therefore misleadingly
point towards nonuniversal nuclear effects. We propose a concrete method to
deal with the absolute normalization and show that an agreement between
independent neutrino data sets is established.


title:
Variable dust formation by the colliding-wind Wolf-Rayet system HD 36402
  in the Large Magellanic Cloud

abstract:
  Infrared photometry of the probable triple WC4(+O?)+O8I: Wolf-Rayet system HD
36402 (= BAT99-38) in the Large Magellanic Cloud (LMC) shows emission
characteristic of heated dust. The dust emission is variable on a time-scale of
years, with a period near 4.7 yr, possibly associated with orbital motion of
the O8 supergiant and the inner P ~ 3.03-d WC4+O binary. The phase of maximum
dust emission is close to that of the X-ray minimum, consistent with both
processes being tied to colliding wind effects in an elliptical binary orbit.
It is evident that Wolf-Rayet dust formation occurs also in metal-poor
environments.


title:
Folding Pathways of a Knotted Protein with a Realistic Atomistic Force
  Field

abstract:
  We report on atomistic simulation of the folding of a natively-knotted
protein, MJ0366, based on a realistic force field. To the best of our knowledge
this is the first reported effort where a realistic force field is used to
investigate the folding pathways of a protein with complex native topology. By
using the dominant-reaction pathway scheme we collected about 30 successful
folding trajectories for the 82-amino acid long trefoil-knotted protein.
Despite the dissimilarity of their initial unfolded configuration, these
trajectories reach the natively-knotted state through a remarkably similar
succession of steps. In particular it is found that knotting occurs essentially
through a threading mechanism, involving the passage of the C-terminal through
an open region created by the formation of the native beta-sheet at an earlier
stage. The dominance of the knotting by threading mechanism is not observed in
MJ0366 folding simulations using simplified, native-centric models. This points
to a previously underappreciated role of concerted amino acid interactions,
including non-native ones, in aiding the appropriate order of contact formation
to achieve knotting.


title:
Central exclusive production as a probe of the gluonic component of the
  eta' and eta mesons

abstract:
  Currently, the long-standing issue concerning the size of the gluonic content
of the eta' and eta mesons remains unsettled. With this in mind we consider the
central exclusive production (CEP) of eta', eta meson pairs in the perturbative
regime, applying the Durham pQCD-based model of CEP and the `hard exclusive'
formalism to evaluate the meson production subprocess. We calculate for the
first time the relevant parton-level processes gg --> qqbar gg and gg --> gggg,
where the final-state gg and qqbar pairs form a pseudoscalar flavour-singlet
state. We observe that these amplitudes display some non-trivial and
interesting theoretical properties, and we comment on how this can be
understood in a MHV framework. Finally, we present a phenomenological study,
and show that the cross sections for the CEP of eta', eta meson pairs are
strongly sensitive to the size of the gluon content of these mesons. The
observation of these processes could therefore provide important and novel
insight into this problem.


title: An artificial atom locked to natural atoms

abstract:
  Single-photon sources that emit photons at the same energy play a key role in
the emerging concepts of quantum information, such as entanglement swapping,
quantum teleportation and quantum networks. They can be realized in a variety
of systems, where semiconductor quantum dots, or 'artificial atoms', are
arguably among the most attractive. However, unlike 'natural atoms', no two
artificial atoms are alike. This peculiarity is a serious hurdle for quantum
information applications that require photonic quantum states with identical
energies. Here we demonstrate a single artificial atom that generates photons
with an absolute energy that is locked to an optical transition in a natural
atom. Furthermore, we show that our system is robust and immune to drifts and
fluctuations in the environment of the emitter. Our demonstration is crucial
for realization of a large number of universally-indistinguishable solid-state
systems at arbitrary remote locations, where frequency-locked artificial atoms
might become fundamental ingredients.


title: Improper ferroelectricity and multiferroism in 2HBaMnO$_3$

abstract:
  Using first-principles calculations, we study theoretically the stable 2H
hexagonal structure of BaMnO3. We show that from the stable high temperature
P63/mmc structure, the compound should exhibit an improper ferroelectric
structural phase transition to a P63cm ground state. Combined with its
antiferromagnetic properties, 2H-BaMnO3 is therefore expected to be
multiferroic at low temperature. The phase transition mechanism in BaMnO3
appears similar to what was reported in YMnO3 in spite of totally different
atomic arrangement, cation sizes and Mn valence state.


title: Linear spectral transformations of Carath\'eodory functions

abstract:
  In this paper we present some recent results concerning linear spectral
transformations of Carath\'eodory functions. More precisely, given two
Carath\'eodory functions related by a linear spectral transformation, we study
the relation between the corresponding moment functionals and, in the positive
definite case, the relation between the measures.
  We will see that rational modifications of functionals are included in the
linear spectral transformations. However, we will show that there exist a huge
class of linear spectral transformations which are not given by rational
modifications of functionals. Indeed, we will characterize those linear
spectral transformation which come from a rational modification.
  In the general case we will discuss the relation between the functionals
involved in a linear spectral transformation, which allows us to identify the
difficulties to connect the related functionals.
  Actually, several examples will show how amazing can be the relationships
between the moment functionals associated with a linear spectral
transformation.


title: Hermitian four-well potential as a realization of a PT-symmetric system

abstract:
  A PT-symmetric Bose-Einstein condensate can be theoretically described using
a complex optical potential, however, the experimental realization of such an
optical potential describing the coherent in- and outcoupling of particles is a
nontrivial task. We propose an experiment for a quantum mechanical realization
of a PT-symmetric system, where the PT-symmetric currents of a two-well system
are implemented by coupling two additional wells to the system, which act as
particle reservoirs. In terms of a simple four-mode model we derive conditions
under which the two middle wells of the Hermitian four-well system behave
exactly as the two wells of the PT-symmetric system. We apply these conditions
to calculate stationary solutions and oscillatory dynamics. By means of frozen
Gaussian wave packets we relate the Gross-Pitaevskii equation to the four-mode
model and give parameters required for the external potential, which provides
approximate conditions for a realistic experimental setup.


title: Stochastic Local Intensity Loss Models with Interacting Particle Systems

abstract:
  It is well-known from the work of Sch\"onbucher (2005) that the marginal laws
of a loss process can be matched by a unit increasing time inhomogeneous Markov
process, whose deterministic jump intensity is called local intensity. The
Stochastic Local Intensity (SLI) models such as the one proposed by Arnsdorf
and Halperin (2008) allow to get a stochastic jump intensity while keeping the
same marginal laws. These models involve a non-linear SDE with jumps. The first
contribution of this paper is to prove the existence and uniqueness of such
processes. This is made by means of an interacting particle system, whose
convergence rate towards the non-linear SDE is analyzed. Second, this approach
provides a powerful way to compute pathwise expectations with the SLI model: we
show that the computational cost is roughly the same as a crude Monte-Carlo
algorithm for standard SDEs.


title:
Sample variance, source clustering and their influence on the counts of
  faint radio sources

abstract:
  The shape of the curves defined by the counts of radio sources per unit area
as a function of their flux density was one of the earliest cosmological
probes. Radio source counts continue to be an area of interest, used to study
the relative populations of galaxy types in the Universe (as well as
investigate any cosmological evolution in luminosity functions). They are a
vital consideration for determining how source confusion may limit the depth of
a radio interferometer observation, and are essential for characterising
extragalactic foregrounds in CMB experiments. There is currently no consensus
as to the relative populations of the faintest (sub-mJy) source types, where
the counts turn-up. Most of the source counts in this regime are gathered from
multiple observations that each use a deep, single pointing with a radio
interferometer. These independent measurements show large amounts of scatter
(factors ~ a few) that significantly exceeds their stated uncertainties. In
this article we use a simulation of the extragalactic radio continuum emission
to assess the level at which sample variance may be the cause of the scatter.
We find that the scatter induced by sample variance in the simulated counts
decreases towards lower flux density bins as the raw source counts increase.
The field-to-field variations are significant, and could even be the sole cause
at >100 {\mu}Jy. We present a method for evaluating the flux density limit that
a survey must reach in order to reduce the count uncertainty induced by sample
variance to a specific value. We also derive a method for correcting Poisson
errors on counts in order to include the uncertainties due to the cosmological
clustering of sources. An empirical constraint on the effect of sample variance
at these low luminosities is unlikely to arise until the completion of new
large-scale surveys with next-generation radio telescopes.


title: Characterization of phase-averaged coherent states

abstract:
  We present the full characterization of phase-randomized or phase-averaged
coherent states, a class of states exploited in communication channels and in
decoy state-based quantum key distribution protocols. In particular, we report
on the suitable formalism to analytically describe the main features of this
class of states and on their experimental investigation, that results in
agreement with theory. We also show the results we obtained by manipulating the
phase-averaged coherent states with linear optical elements and testify their
good quality by employing some non-Gaussianity measures and the concept of
mutual information.


title:
Abrupt barrier contribution to the electron spin splitting in asymmetric
  coupled double quantum wells

abstract:
  We have studied the behavior of the electronic energy spin-splitting of
InGaAs-InAlAs based double quantum wells (narrow gap structures) under in-plane
magnetic and transverse electric fields. We have developed an improved 8x8
version of the Transfer Matrix Approach that consider contributions from abrupt
interfaces and external fields when tunneling through central barrier exists.
We have included the Land\'e g-factor dependence on the external applied field.
Also, we have calculated electron density of states and photoluminescence
excitation. Variations of the electron spin-splitting energy lead to marked
peculiarities in the density of states. Because the density of states is
directly related to photoluminescence excitation, these peculiarities are
observable by this technique.


title: Pure-hydrogen 3D model atmospheres of cool white dwarfs

abstract:
  A sequence of pure-hydrogen CO5BOLD 3D model atmospheres of DA white dwarfs
is presented for a surface gravity of log g = 8 and effective temperatures from
6000 to 13,000 K. We show that convective properties, such as flow velocities,
characteristic granulation size and intensity contrast of the granulation
patterns, change significantly over this range. We demonstrate that these 3D
simulations are not sensitive to numerical parameters unlike the 1D structures
that considerably depend on the mixing-length parameters. We conclude that 3D
spectra can be used directly in the spectroscopic analyses of DA white dwarfs.
We confirm the result of an earlier preliminary study that 3D model spectra
provide a much better characterization of the mass distribution of white dwarfs
and that shortcomings of the 1D mixing-length theory are responsible for the
spurious high-log g determinations of cool white dwarfs. In particular, the 1D
theory is unable to account for the cooling effect of the convective overshoot
in the upper atmospheres.


title:
Quantized coexisting electrons and holes in graphene measured using
  temperature dependent magneto-transport

abstract:
  We present temperature-dependent magneto-transport experiments around the
charge neutrality point in graphene and determine the amplitude of potential
fluctuations $s$ responsible for the formation of electron-hole puddles. The
experimental value $s \approx 20$ meV is considerably larger than in
conventional semiconductors which implies a strong localization of charge
carriers observable up to room temperature. Surprisingly, in the quantized
regime, the Hall resistivity overshoots the highest plateau values at high
temperatures. We demonstrate by model calculations that such a peculiar
behavior is expected in any system with coexisting electrons and holes when the
energy spectrum is quantized and the carriers are partially localized.


title: Persistence modules: Algebra and algorithms

abstract:
  Persistent homology was shown by Carlsson and Zomorodian to be homology of
graded chain complexes with coefficients in the graded ring $\kk[t]$. As such,
the behavior of persistence modules -- graded modules over $\kk[t]$ is an
important part in the analysis and computation of persistent homology.
  In this paper we present a number of facts about persistence modules; ranging
from the well-known but under-utilized to the reconstruction of techniques to
work in a purely algebraic approach to persistent homology. In particular, the
results we present give concrete algorithms to compute the persistent homology
of a simplicial complex with torsion in the chain complex.


title: Petrov type I Condition and Dual Fluid Dynamics

abstract:
  Recently Lysov and Strominger [arXiv:1104.5502] showed that imposing Petrov
type I condition on a $(p+1)$-dimensional timelike hypersurface embedded in a
$(p+2)$-dimensional vacuum Einstein gravity reduces the degrees of freedom in
the extrinsic curvature of the hypersurface to that of a fluid on the
hypersurface, and that the leading-order Einstein constraint equations in terms
of the mean curvature of the embedding give the incompressible Navier-Stokes
equations of the dual fluid. In this paper we show that the non-relativistic
fluid dual to vacuum Einstein gravity does not satisfy the Petrov type I
condition at next order, unless additional constraint such as the irrotational
condition is added. In addition, we show that this procedure can be inversed to
derive the non-relativistic hydrodynamics with higher order corrections through
imposing the Petrov type I condition, and that some second order transport
coefficients can be extracted, but the dual "Petrov type I fluid" does not
match the dual fluid constructed from the geometry of vacuum Einstein gravity
in the non-relativistic limit. We discuss the procedure both on the finite
cutoff surface via the non-relativistic hydrodynamic expansion and on the
highly accelerated surface via the near horizon expansion.


title:
Cooperative Environmental Monitoring for PTZ Visual Sensor Networks: A
  Payoff-based Learning Approach

abstract:
  This paper investigates cooperative environmental monitoring for
Pan-Tilt-Zoom (PTZ) visual sensor networks. We first present a novel
formulation of the optimal environmental monitoring problem, whose objective
function is intertwined with the uncertain state of the environment. In
addition, due to the large volume of vision data, it is desired for each sensor
to execute processing through local computation and communication. To address
the issues, we present a distributed solution to the problem based on game
theoretic cooperative control and payoff-based learning. At the first stage, a
utility function is designed so that the resulting game constitutes a potential
game with potential function equal to the group objective function, where the
designed utility is shown to be computable through local image processing and
communication. Then, we present a payoff-based learning algorithm so that the
sensors are led to the global objective function maximizers without using any
prior information on the environmental state. Finally, we run experiments to
demonstrate the effectiveness of the present approach.


title: On polyharmonic univalent mappings

abstract:
  In this paper, we introduce a class of complex-valued polyharmonic mappings,
denoted by $HS_{p}(\lambda)$, and its subclass $HS_{p}^{0}(\lambda)$, where
$\lambda\in [0,1]$ is a constant. These classes are natural generalizations of
a class of mappings studied by Goodman in 1950's. We generalize the main
results of Avci and Z{\l}otkiewicz from 1990's to the classes $HS_{p}(\lambda)$
and $HS_{p}^{0}(\lambda)$, showing that the mappings in $HS_{p}(\lambda)$ are
univalent and sense preserving. We also prove that the mappings in
$HS_{p}^{0}(\lambda)$ are starlike with respect to the origin, and characterize
the extremal points of the above classes.


title:
Bounds on the Expected Value of Maximum Loss of Fractional Brownian
  Motion

abstract:
  In this study, it is theoretically proven that the expected value of maximum
loss of fractional Brownian motion (fBm) up to time 1 with Hurst parameter
$[1/2,1)$ is bounded above by $2/\sqrt{\pi}$ and below by $1/\sqrt{\pi}$. This
result is generalized for fBm with $H\in[1/2,1)$ up to any fixed time, $t$.
This also leads us to the bounds related to the distribution of maximum loss of
fBm. As numerical study some lower bounds on the expected value of maximum loss
of fBm up to time 1 are obtained by discretization. Simulation study is
conducted with Cholesky method. Finally, comparison of the established bounds
with simulation results is given.


title: Fluctuations in multiplicative systems with jumps

abstract:
  Fluctuation properties of the Langevin equation including a multiplicative,
power-law noise and a quadratic potential are discussed. The noise has the Levy
stable distribution. If this distribution is truncated, the covariance can be
derived in the limit of large time; it falls exponentially. Covariance in the
stable case, studied for the Cauchy distribution, exhibits a weakly stretched
exponential shape and can be approximated by the simple exponential. The
dependence of that function on system parameters is determined. Then we
consider a dynamics which involves the above process and obey the generalised
Langevin equation, the same as for Gaussian case. The resulting distributions
possess power-law tails - that fall similarly to those for the driving noise -
whereas central parts can assume the Gaussian shape. Moreover, a process with
the covariance 1/t at large time is constructed and the corresponding dynamical
equation solved. Diffusion properties of systems for both covariances are
discussed.


title: Very Massive Stars (VMS) in the Local Universe

abstract:
  Recent studies have claimed the existence of very massive stars (VMS) up to
300 solar masses in the local Universe. As this finding may represent a
paradigm shift for the canonical stellar upper-mass limit of 150 Msun, it is
timely to discuss the status of the data, as well as the far-reaching
implications of such objects. We held a Joint Discussion at the General
Assembly in Beijing to discuss (i) the determination of the current masses of
the most massive stars, (ii) the formation of VMS, (iii) their mass loss, and
(iv) their evolution and final fate. The prime aim was to reach broad consensus
between observers and theorists on how to identify and quantify the dominant
physical processes.

categories: astro-ph.SR astro-ph.CO astro-ph.GA astro-ph.HE


title:
Single-Crystal Organic Charge-Transfer Interfaces probed using
  Schottky-Gated Heterostructures

abstract:
  Organic semiconductors based on small conjugated molecules generally behave
as insulators when undoped, but the hetero-interfaces of two such materials can
show electrical conductivity as large as in a metal. Although charge transfer
is commonly invoked to explain the phenomenon, the details of the process and
the nature of the interfacial charge carriers remain largely unexplored. Here
we use Schottky-gated heterostructures to probe the conducting layer at the
interface between rubrene and PDIF-CN2 single crystals. Gate-modulated
conductivity measurements demonstrate that interfacial transport is due to
electrons, whose mobility exhibits band-like behavior from room temperature to
~ 150 K, and remains as high as ~ 1 cm2V-1s-1 at 30 K for the best devices. The
electron density decreases linearly with decreasing temperature, an observation
that can be explained quantitatively based on the heterostructure band diagram.
These results elucidate the electronic structure of rubrene-PDIF-CN2 interfaces
and show the potential of Schottky-gated organic heterostructures for the
investigation of transport in molecular semiconductors.


title: Random sets and exact confidence regions

abstract:
  An important problem in statistics is the construction of confidence regions
for unknown parameters. In most cases, asymptotic distribution theory is used
to construct confidence regions, so any coverage probability claims only hold
approximately, for large samples. This paper describes a new approach, using
random sets, which allows users to construct exact confidence regions without
appeal to asymptotic theory. In particular, if the user-specified random set
satisfies a certain validity property, confidence regions obtained by
thresholding the induced data-dependent plausibility function are shown to have
the desired coverage probability.


title: User Interface for Volume Rendering in Virtual Reality Environments

abstract:
  Volume Rendering applications require sophisticated user interaction for the
definition and refinement of transfer functions. Traditional 2D desktop user
interface elements have been developed to solve this task, but such concepts do
not map well to the interaction devices available in Virtual Reality
environments.
  In this paper, we propose an intuitive user interface for Volume Rendering
specifically designed for Virtual Reality environments. The proposed interface
allows transfer function design and refinement based on intuitive two-handed
operation of Wand-like controllers. Additional interaction modes such as
navigation and clip plane manipulation are supported as well.
  The system is implemented using the Sony PlayStation Move controller system.
This choice is based on controller device capabilities as well as application
and environment constraints.
  Initial results document the potential of our approach.


title: Foldings and Meanders

abstract:
  We review the stamp folding problem, the number of ways to fold a strip of
$n$ stamps, and the related problem of enumerating meander configurations. The
study of equivalence classes of foldings and meanders under symmetries allows
to characterize and enumerate folding and meander shapes. Symmetric foldings
and meanders are described, and relations between folding and meandric
sequences are given. Extended tables for these sequences are provided.


title: Fixed field alternating gradient

abstract:
  The concept of a fixed field alternating gradient (FFAG) accelerator was
invented in the 1950s. Although many studies were carried out up to the late
1960s, there has been relatively little progress until recently, when it
received widespread attention as a type of accelerator suitable for very fast
acceleration and for generating high-power beams. In this paper, we describe
the principles and design procedure of a FFAG accelerator.


title:
On the statistical description of the inbound air traffic over Heathrow
  airport

abstract:
  We present a model to describe the inbound air traffic over a congested hub.
We show that this model gives a very accurate description of the traffic by the
comparison of our theoretical distribution of the queue with the actual
distribution observed over Heathrow airport. We discuss also the robustness of
our model.


title: Content-based data leakage detection using extended fingerprinting

abstract:
  Protecting sensitive information from unauthorized disclosure is a major
concern of every organization. As an organizations employees need to access
such information in order to carry out their daily work, data leakage detection
is both an essential and challenging task. Whether caused by malicious intent
or an inadvertent mistake, data loss can result in significant damage to the
organization. Fingerprinting is a content-based method used for detecting data
leakage. In fingerprinting, signatures of known confidential content are
extracted and matched with outgoing content in order to detect leakage of
sensitive content. Existing fingerprinting methods, however, suffer from two
major limitations. First, fingerprinting can be bypassed by rephrasing (or
minor modification) of the confidential content, and second, usually the whole
content of document is fingerprinted (including non-confidential parts),
resulting in false alarms. In this paper we propose an extension to the
fingerprinting approach that is based on sorted k-skip-n-grams. The proposed
method is able to produce a fingerprint of the core confidential content which
ignores non-relevant (non-confidential) sections. In addition, the proposed
fingerprint method is more robust to rephrasing and can also be used to detect
a previously unseen confidential document and therefore provide better
detection of intentional leakage incidents.


title: Stability of thin liquid films and sessile droplets under confinement

abstract:
  The stability of nonvolatile thin liquid films and of sessile droplets is
strongly affected by finite size effects. We analyze their stability within the
framework of density functional theory using the sharp kink approximation,
i.e., on the basis of an effective interface Hamiltonian. We show that finite
size effects suppress spinodal dewetting of films because it is driven by a
long-wavelength instability. Therefore nonvolatile films are stable if the
substrate area is too small. Similarly, nonvolatile droplets connected to a
wetting film become unstable if the substrate area is too large. This
instability of a nonvolatile sessile droplet turns out to be equivalent to the
instability of a volatile drop which can attain chemical equilibrium with its
vapor.


title:
Stress-strain relations in bulk metallic glasses and colloidal
  dispersions

abstract:
  A comparison is made between the nonlinear rheological response of bulk
metallic glass formers and of colloidal dispersions. Stress-strain curves
measured after switch-on of constant deformation rates are analyzed
quantitatively using a schematic model of mode coupling theory generalized to
homogeneous and incompressible flows. A mapping between metallic and dispersion
rheology is possible when stresses are rescaled by an entropic scale,
accumulated strains by geometrical factors, and rates by the intrinsic
relaxation time. Exploiting this similarity and the possibility to directly
observe individual colloidal particles, we investigate the structural
distortions in the colloidal system using confocal microscopy. The distortions
exhibit the (from elasticity theory) expected quadrupolar but also a strong
isotropic component.


title: Ab initio strategy for muon site assignment in wide band gap fluorides

abstract:
  We report on an ab initio strategy based on Density Functional Theory to
identify the muon sites. Two issues must be carefully addressed, muon
delocalization about candidate interstitial sites and local structural
relaxation of the atomic positions due to $\mu^+$-sample interaction. Here, we
report on the validation of our strategy on two wide band gap materials, LiF
and YF3, where localization issues are important because of the interplay
between muon localization and lattice relaxation


title:
Influence of a keV sterile neutrino on neutrino-less double beta decay
  -- how things changed in the recent years

abstract:
  Earlier studies of the influence of Dark Matter keV sterile neutrinos on
neutrino-less double beta decay concluded that there is no significant
modification of the decay rate. These studies have focused only on a mass of
the keV sterile neutrino above 2 and 4 keV, respectively, as motivated by
certain production mechanisms. On the other hand, alternative production
mechanisms have been proposed, which relax the lower limit for the mass, and
new experimental data are available, too. For this reason, an updated study is
timely and worthwhile. We focus on the most recent data, i.e., the newest
Chandra and XMM-Newton observational bounds on the X-ray line originating from
radiative keV sterile neutrino decay, as well as the new measurement of the
previously unknown leptonic mixing angle $\theta_{13}$. While the previous
works might have been a little short-sighted, the new observational bounds do
indeed render any influences of keV sterile neutrinos on neutrino-less double
beta decay small. This conclusion even holds in case not all the Dark Matter is
made up of keV sterile neutrinos.


title:
AGN and star formation activity in local luminous and ultraluminous
  infrared galaxies

abstract:
  The enormous amounts of infrared (IR) radiation emitted by luminous infrared
galaxies (LIRGs, L_IR=10^11-10^12Lsun) and ultraluminous infrared galaxies
(ULIRGs, L_IR>10^12Lsun) are produced by dust heated by intense star formation
(SF) activity and/or an active galactic nucleus (AGN). The elevated star
formation rates and high AGN incidence in (U)LIRGs make them ideal candidates
to study the interplay between SF and AGN activity in the local universe. In
this paper I review recent results on the physical extent of the SF activity,
the AGN detection rate (including buried AGN), the AGN bolometric contribution
to the luminosity of the systems, as well as the evolution of local LIRGs and
ULIRGs. The main emphasis of this review is on recent results from IR
observations.


title: The Fourier restriction norm method for the Zakharov-Kuznetsov equation

abstract:
  The Cauchy problem for the Zakharov-Kuznetsov equation is shown to be locally
well-posed in H^s(R^2) for all s>1/2 by using the Fourier restriction norm
method and bilinear refinements of Strichartz type inequalities.


title: New Concept of Solvability in Quantum Mechanics

abstract:
  In a pre-selected Hilbert space of quantum states the unitarity of the
evolution is usually guaranteed via a pre-selection of the generator (i.e., of
the Hamiltonian operator) in self-adjoint form. In fact, the simultaneous use
of both of these pre-selections is overrestrictive. One should be allowed to
make a given Hamiltonian self-adjoint only after an {\em ad hoc} generalization
of Hermitian conjugation. We argue that in the generalized, hidden-Hermiticity
scenario with nontrivial metric, the current concept of solvability (meaning,
most often, the feasibility of a non-numerical diagonalization of Hamiltonian)
requires a generalization allowing for a non-numerical form of metric. A few
illustrative solvable quantum models of this type are presented.


title: On $\pi$-extensions of the semigroup $\mathbb{Z}_+$

abstract:
  We study inverse $\pi$-extensions of the semigroup $\mathbb{Z}_+$. It is
shown that $\pi$-extension of the semigroup $\mathbb{Z}_+$ is inverse, iff its
$\pi$-extension coincides with $\pi(\mathbb{Z}_+)$. The existence of a
non-inverse $\pi$-extension for semigroup $\mathbb{Z}_+$ is proved.


title:
Growth rates of permutation grid classes, tours on graphs, and the
  spectral radius

abstract:
  Monotone grid classes of permutations have proven very effective in helping
to determine structural and enumerative properties of classical permutation
pattern classes. Associated with grid class $\mathrm{Grid}(M)$ is a graph,
$G(M)$, known as its "row-column" graph. We prove that the exponential growth
rate of $\mathrm{Grid}(M)$ is equal to the square of the spectral radius of
$G(M)$. Consequently, we utilize spectral graph theoretic results to
characterise all slowly growing grid classes and to show that for every
$\gamma\geqslant2+\sqrt{5}$ there is a grid class with growth rate arbitrarily
close to $\gamma$. To prove our main result, we establish bounds on the size of
certain families of tours on graphs. In the process, we prove that the family
of tours of even length on a connected graph grows at the same rate as the
family of "balanced" tours on the graph (in which the number of times an edge
is traversed in one direction is the same as the number of times it is
traversed in the other direction).


title: The spectrum of gravitational waves in an f(R) model with a bounce

abstract:
  We present an inflationary model preceded by a bounce in a metric $f(R)$
theory. In this model, modified gravity affects only the early stages of the
universe. We analyse the predicted spectrum of the gravitational waves in this
scenario using the method of the Bogoliubov coefficients. We show that there
are distinctive (oscillatory) signals on the spectrum for very low frequencies;
i.e., corresponding to modes that are currently entering the horizon.


title: Representations of certain Banach algebras

abstract:
  For a space $X$ denote by $C_b(X)$ the Banach algebra of all continuous
bounded scalar-valued functions on $X$ and denote by $C_0(X)$ the set of all
elements in $C_b(X)$ which vanish at infinity.
  We prove that certain Banach subalgebras $H$ of $C_b(X)$ are isometrically
isomorphic to $C_0(Y)$, for some unique (up to homeomorphism) locally compact
Hausdorff space $Y$. The space $Y$ is explicitly constructed as a subspace of
the Stone--\v{C}ech compactification of $X$. The known construction of $Y$
enables us to examine certain properties of either $H$ or $Y$ and derive
results not expected to be deducible from the standard Gelfand Theory.


title: Supernova Detection in IceCube: Status and Future

abstract:
  The IceCube detector, located at the South Pole, is discussed as a detector
for core collapse supernovae. The large flux of $\bar{\nu}_{e}$ from a Galactic
supernova gives rise to Cherenkov light from positrons and electrons created in
neutrino interactions which increase the overall count rate of the
photomultipliers significantly. We will give an overview of the standard, count
rate based, method for supernova detection and present the development of a
novel technique. This technique uses coincident hits to extract additional
information such as the average energy and spectral features. The potential of
this technique increases with a higher sensor density, such as foreseen in
projected extensions of IceCube/DeepCore.


title: Pattern Analysis of Tandem Repeats in Nlrp1

abstract:
  Pattern analysis of tandem repeats in gene is an indispensable computational
approach to the understanding of the gene expression and pathogenesis of
diseases. This research applied a computational motif model and database
techniques to study the distribution of tandem repeats in Nlrp1 gene, which is
a critical gene to detect the invading pathogens in the immunologic mechanisms.
The frequency of tandem repeats in Nlrp1 gene was studied for mono-, di-, tri-,
and tetranucleotides. Mutations of Nlrp1 gene were analyzed to identify the
insertion,deletion, and substitution of nucleotides. The results of this
research provide a basis for future work in computational drug design and
biomedical engineering in tackling diseases associated with immune system.


title:
Free-free transitions in a bichromatic field of frequencies $\omega $
  and $2\omega$ at moderate field intensities

abstract:
  Free-free transitions in laser-assisted electron-hydrogen scattering in a
bichromatic field of frequencies $\omega $ and $2\omega $ are studied at
moderate intensities for fast projectiles. A hybrid approach is used, in which
the field-projectile interaction is described exactly but the field-target one
is described by second order perturbation theory; the projectile-target
interaction is treated in the first Born approximation. The adopted description
of the target enables a consistent study of the leading process to each of the
considered sidebands. Numerical results are presented for the angular
distributions in a geometry and at frequencies for which the target dressing is
important. The influence of the relative phase between the fields is
investigated, too.


title:
Bayesian methods in the Shape Invariant Model (I): Posterior contraction
  rates on probability measures

abstract:
  In this paper, we consider the so-called Shape Invariant Model which stands
for the estimation of a function f0 submitted to a random translation of law g0
in a white noise model. We are interested in such a model when the law of the
deformations is unknown. We aim to recover the law of the process P(f0,g0). In
this perspective, we adopt a Bayesian point of view and find prior on f and g
such that the posterior distribution concentrates at a polynomial rate around
P(f0,g0) when n goes to infinity. We intensively use some Bayesian non
parametric tools coupled with mixture models and believe that some of our
results obtained on this mixture framework may be also of interest for
frequentist point of view.


title:
Bayesian methods in the Shape Invariant Model (II): Identifiability and
  posterior contraction rates on functional spaces

abstract:
  In this paper, we consider the so-called Shape Invariant Model which stands
for the estimation of a function f0 submitted to a random translation of law g0
in a white noise model. We are interested in such a model when the law of the
deformations is unknown. We aim to recover the law of the process P(f0,g0) as
well as f0 and g0.
  We first provide some identifiability result on this model and then adopt a
Bayesian point of view. In this view, we find some prior on f and g such that
the posterior distribution concentrates around the functions f0 and g0 when n
goes to infinity, we then obtain a contraction rate of order a power of
log(n)^(-1). We also obtain a lower bound on the model for the estimation of f0
and g0 in a frequentist paradigm which also decreases following a power of
log(n)^(-1).


title:
Interaction between massive planets on inclined orbits and circumstellar
  discs

abstract:
  We study the interaction between massive planets and a gas disc with a mass
in the range expected for protoplanetary discs. We use SPH simulations to study
the orbital evolution of a massive planet as well as the dynamical response of
the disc for planet masses between 1 and $6\ \rmn{M_J}$ and the full range of
initial relative orbital inclinations. Gap formation can occur for planets in
inclined orbits. For given planet mass, a threshold relative orbital
inclination exists under which a gap forms. At high relative inclinations, the
inclination decay rate increases for increasing planet mass and decreasing
initial relative inclination.
  For an initial semi-major axis of 5 AU and relative inclination of
$i_0=80^\circ,$ the times required for the inclination to decay by $10^\circ$
is $\sim10^{6}\ \rmn{yr}$ and $\sim10^{5}\ \rmn{yr}$ for $1\ \rmn{M_J}$ and $6\
\rmn{M_J}$. Planets on inclined orbits warp the disc by an extent that is
negligible for $1\ \rmn{M_J}$ but increases with increasing mass becoming quite
significant for a planet of mass $6\ \rmn{M_J}$. We also find a solid body
precession of both the total disc angular momentum vector and the planet
orbital momentum vector about the total angular momentum vector. Our results
illustrate that the influence of an inclined massive planet on a protoplanetary
disc can lead to significant changes of the disc structure and orientation
which can in turn affect the orbital evolution of the planet significantly.


title: A quadratic Poisson Gel'fand-Kirillov problem in prime characteristic

abstract:
  The quadratic Poisson Gel'fand-Kirillov problem asks whether the field of
fractions of a Poisson algebra is Poisson birationally equivalent to a Poisson
affine space, i.e. to a polynomial algebra $\K[X_1,..., X_n]$ with Poisson
bracket defined by $\{X_i,X_j\}=\lambda_{ij} X_iX_j$ for some skew-symmetric
matrix $(\lambda_{ij}) \in M_n(\K)$. This problem was studied in \cite{GL} over
a field of characteristic 0 by using a Poisson version of the
deleting-derivations algorithm of Cauchon. In this paper, we study the
quadratic Poisson Gel'fand-Kirillov problem over a field of arbitrary
characteristic. In particular, we prove that the quadratic Poisson
Gel'fand-Kirillov problem is satisfied for a large class of Poisson algebras
arising as semiclassical limits of quantised coordinate rings. For, we
introduce the concept of {\it higher Poisson derivation} which allows us to
extend the Poisson version of the deleting-derivations algorithm from the
characteristic 0 case to the case of arbitrary characteristic.
  When a torus is acting rationally by Poisson automorphisms on a Poisson
polynomial algebra arising as the semiclassical limit of a quantised coordinate
ring, we prove (under some technical assumptions) that quotients by Poisson
prime torus-invariant ideals also satisfy the quadratic Poisson
Gel'fand-Kirillov problem. In particular, we show that coordinate rings of
determinantal varieties satisfy the quadratic Poisson Gel'fand-Kirillov
problem.


title: In Silico Analysis of Tandem Repeats in GIF of Gastric Parietal Cells

abstract:
  Tandem repeats are ubiquitous in the genome of organisms and their mutated
forms play a vital role in pathogenesis. In this study, tandem repeats in
Gastric Intrinsic Factor (GIF) of gastric parietal cells have been investigated
using an in silico approach. Six types of the nucleotide tandem repeat motifs
have been investigated, including mono-, di-, tri-, tetra-, penta- and
hexanucleotide. The distribution of the repeat motifs in the gene was analyzed.
The results of this study provide an insight into the biomolecular mechanisms
and pathogenesis implicated by the GIF of gastric parietal cells. Based on the
findings of the tandem repeats in GIF of gastric parietal cells, therapeutic
strategies and disease markers may be developed accordingly by the biomedical
scientists.


title:
Improving success probability and embedding efficiency in code based
  steganography

abstract:
  For stegoschemes arising from error correcting codes, embedding depends on a
decoding map for the corresponding code. As decoding maps are usually not
complete, embedding can fail. We propose a method to ensure or increase the
probability of embedding success for these stegoschemes. This method is based
on puncturing codes. We show how the use of punctured codes may also increase
the embedding efficiency of the obtained stegoschemes.


title: Low-mass dielectron measurement in pp and Pb--Pb collisions in ALICE

abstract:
  We report on the first dielectron measurement in pp collisons at $\sqrt{s} =
7$ TeV with the ALICE detector system. The results are compared to the expected
hadronic sources. The hadronic cocktail agrees to the measured dielectron
continuum within statistical and systematic uncertainties. The status of the
dielectron measurement in Pb--Pb collisions at {$\sqrt{s_{NN}}=2.76$} TeV is
addressed.


title: Quantum corrections to broken N=8 supergravity

abstract:
  The discovery of the Higgs boson and the non-discovery (so far) of additional
particles at the TeV scale underline our poor understanding of the hierarchy
problems in the physics of the fundamental interactions. Loosely motivated by
this consideration, I review some recent results on the classical and quantum
stability of Minkowski vacua in spontaneously broken N=8 supergravity.


title: On the Generating Hypothesis in Noncommutative Stable Homotopy

abstract:
  Freyd's Generating Hypothesis is an important problem in topology with deep
structural consequences for finite stable homotopy. Due to its complexity some
recent work has examined analogous questions in various other triangulated
categories. In this short note we analyze the question in noncommutative stable
homotopy, which is a canonical generalization of finite stable homotopy. Along
the way we also discuss Spanier--Whitehead duality in this extended setup.


title: Combinatorial simpliciality of arrangements of hyperplanes

abstract:
  We introduce a combinatorial characterization of simpliciality for
arrangements of hyperplanes. We then give a sharp upper bound for the number of
hyperplanes of such an arrangement in the projective plane over a finite field,
and present some series of arrangements related to the known arrangements in
characteristic zero. We further enumerate simplicial arrangements with given
symmetry groups. Finally, we determine all finite complex reflection groups
affording combinatorially simplicial arrangements. It turns out that
combinatorial simpliciality coincides with inductive freeness for finite
complex reflection groups except for the Shephard-Todd group $G_{31}$.


title: The pulsar spectral index distribution

abstract:
  The flux density spectra of radio pulsars are known to be steep and, to first
order, described by a power-law relationship of the form S_{\nu} \propto
\nu^{\alpha}, where S_{\nu} is the flux density at some frequency \nu and
\alpha is the spectral index. Although measurements of \alpha have been made
over the years for several hundred pulsars, a study of the intrinsic
distribution of pulsar spectra has not been carried out. From the result of
pulsar surveys carried out at three different radio frequencies, we use
population synthesis techniques and a likelihood analysis to deduce what
underlying spectral index distribution is required to replicate the results of
these surveys. We find that in general the results of the surveys can be
modelled by a Gaussian distribution of spectral indices with a mean of -1.4 and
unit standard deviation. We also consider the impact of the so-called
"Gigahertz-peaked spectrum" pulsars. The fraction of peaked spectrum sources in
the population with significant turn-over at low frequencies appears to be at
most 10%. We demonstrate that high-frequency (>2 GHz) surveys preferentially
select flatter-spectrum pulsars and the converse is true for lower-frequency
(<1 GHz) surveys. This implies that any correlations between \alpha and other
pulsar parameters (for example age or magnetic field) need to carefully account
for selection biases in pulsar surveys. We also expect that many known pulsars
which have been detected at high frequencies will have shallow, or positive,
spectral indices. The majority of pulsars do not have recorded flux density
measurements over a wide frequency range, making it impossible to constrain
their spectral shapes. We also suggest that such measurements would allow an
improved description of any populations of pulsars with 'non-standard' spectra.


title:
A mathematical theory of D-string world-sheet instantons, I: Compactness
  of the stack of $Z$-semistable Fourier-Mukai transforms from a compact family
  of nodal curves to a projective Calabi-Yau 3-fold

abstract:
  In a suitable regime of superstring theory, D-branes in a Calabi-Yau space
and their most fundamental behaviors can be nicely described mathematically
through morphisms from Azumaya spaces with a fundamental module to that
Calabi-Yau space. In the earlier work [L-L-S-Y] (D(2): arXiv:0809.2121
[math.AG], with Si Li and Ruifang Song) from the project, we explored this
notion for the case of D1-branes (i.e. D-strings) and laid down some basic
ingredients toward understanding the notion of D-string world-sheet instantons
in this context. In this continuation, D(10), of D(2), we move on to construct
a moduli stack of semistable morphisms from Azumaya nodal curves with a
fundamental module to a projective Calabi-Yau 3-fold $Y$. In this Part I of the
note, D(10.1), we define the notion of twisted central charge $Z$ for
Fourier-Mukai transforms of dimension 1 and width [0] from nodal curves and the
associated stability condition on such transforms and prove that for a given
compact stack of nodal curves $C_{\cal M}/{\cal M}$, the stack
$FM^{1,[0];Zss}_{C_{\cal M}/{\cal M}}(Y,c)$ of $Z$-semistable Fourier-Mukai
transforms of dimension 1 and width [0] from nodal curves in the family
$C_{\cal M}/{\cal M}$ to $Y$ of fixed twisted central charge $c$ is compact.
For the application in the sequel D(10.2), $C_{\cal M}/{\cal M}$ will contain
$C_{\bar{\cal M}_g}/\bar{\cal M}_g$ as a substack and $FM^{1,[0];Zss}_{C_{\cal
M}/{\cal M}}(Y,c)$ in this case will play a key role in defining stability
condition for morphisms from arbitrary Azumaya nodal curves (with the
underlying nodal curves not necessary in the family $C_{\cal M}/{\cal M}$) to
$Y$.


title:
Interaction-induced correlations and non-Markovianity of quantum
  dynamics

abstract:
  We investigate the conditions under which the trace distance between two
different states of a given open system increases in time due to the
interaction with an environment, therefore signalling non-Markovianity. We find
that the finite-time difference in trace distance is bounded by two sharply
defined quantities that are strictly linked to the occurrence of
system-environment correlations created throughout their interaction and
affecting the subsequent evolution of the system. This allows to shed light on
the origin of non-Markovian behaviours in quantum dynamics. We best illustrate
our findings by tackling two physically relevant examples: a non-Markovian
dephasing mechanism that has been the focus of a recent experimental endeavour
and the open-system dynamics experienced by a spin connected to a finite-size
quantum spin chain.


title: Complexity distribution of agent policies

abstract:
  We analyse the complexity of environments according to the policies that need
to be used to achieve high performance. The performance results for a
population of policies leads to a distribution that is examined in terms of
policy complexity and analysed through several diagrams and indicators. The
notion of environment response curve is also introduced, by inverting the
performance results into an ability scale. We apply all these concepts,
diagrams and indicators to a minimalistic environment class, agent-populated
elementary cellular automata, showing how the difficulty, discriminating power
and ranges (previous to normalisation) may vary for several environments.


title:
Quantization of the massless scalar field in de Sitter spacetime with
  unitary dynamics

abstract:
  We present a Fock quantization with unitary dynamics for the massless scalar
field in de Sitter spacetime.


title:
Diffractive photon production at high momentum transfer in $ep$
  collisions

abstract:
  The diffractive photon production at large momentum transfer and large
energies is a probe of the parton dynamics of the diffractive exchange. In this
paper we revisit the leading order (LO) BFKL equation approach for this process
and estimate, for the first time, the differential and total cross sections
considering the next-to-leading order (NLO) corrections for the BFKL
characteristic function. We obtain a reasonable agreement with the DESY HERA
data.


title:
Hamiltonian Composite Dynamics Can Almost Always Lead To Negative
  Reduced Dynamics

abstract:
  Complete positivity is a ubiquitous assumption in the study of quantum
systems interacting with the environment, despite repeated efforts to point out
that the assumption is not empirically justified. It will be shown that
Hamiltonian evolution of a quantum system and its environment can be negative
(i.e.\ not completely positive) in the energy basis, by showing that such
evolution is {\it almost always} negative for given initial conditions.
Ignoring or "correcting" experimental data that is not completely positive may
cause the loss of important information regarding system-environment
correlations and coupling. A relationship between the negativity of an
evolution and the eigenvalues of the Hamiltonian will be shown, and
experimental verification of negative reduced dynamics will be proposed.


title: Tests For Complete Positivity of Quantum Channels

abstract:
  A quantum channel will have a Choi representation from which the complete
positivity (CP) can be determined in a number of different ways. Every method
relies on Choi's proof which relates CP to the positive semi-definiteness of a
specially constructed matrix (i.e. the "Choi representation of the channel").
It can be shown that different CP tests can be used in different situations to
avoid the computationally expensive brute force method of calculating the full
spectrum of the Choi representation, which is the traditional method for
testing whether or not a channel is CP. It is important to have quick, reliable
analytical and computational tests for CP as negative channels become more
prevalent in the study of quantum information.


title: On Families in Differential Geometry

abstract:
  Families of objects appear in several contexts, like algebraic topology,
theory of deformations, theoretical physics, etc. An unified coordinate-free
algebraic framework for families of geometrical quantities is presented here,
which allows one to work without introducing ad hoc spaces, by using the
language of differential calculus over commutative algebras. An advantage of
such an approach, based on the notion of sliceable structures on cylinders, is
that the fundamental theorems of standard calculus are straightforwardly
generalized to the context of families. As an example of that, we prove the
universal homotopy formula.


title:
Quotients of one-sided trianglated categories by rigid subcategories as
  module categories

abstract:
  We prove that some subquotient categories of one-sided triangulated
categories are abelian. This unifies a result by Iyama-Yoshino in the case of
triangulated categories and a result by Demonet-Liu in the case of exact
categories.


title: Early-warning signals of topological collapse in interbank networks

abstract:
  The financial crisis clearly illustrated the importance of characterizing the
level of 'systemic' risk associated with an entire credit network, rather than
with single institutions. However, the interplay between financial distress and
topological changes is still poorly understood. Here we analyze the quarterly
interbank exposures among Dutch banks over the period 1998-2008, ending with
the crisis. After controlling for the link density, many topological properties
display an abrupt change in 2008, providing a clear - but unpredictable -
signature of the crisis. By contrast, if the heterogeneity of banks'
connectivity is controlled for, the same properties show a gradual transition
to the crisis, starting in 2005 and preceded by an even earlier period during
which anomalous debt loops could have led to the underestimation of
counter-party risk. These early-warning signals are undetectable if the network
is reconstructed from partial bank-specific data, as routinely done. We discuss
important implications for bank regulatory policies.

categories: physics.soc-ph physics.data-an q-fin.GN q-fin.RM


title: Magnetic flux loop in high-energy heavy-ion collisions

abstract:
  We consider the expectation value of a magnetic flux loop in the immediate
forward light cone of collisions of heavy nuclei at high energies. Such
collisions are characterized by a non-linear scale Q_s where color fields
become strong. We find that loops of area greater than ~2/Q_s^2 exhibit area
law behavior, which determines the scale of elementary flux excitations
("vortices"). We also estimate the magnetic string tension, sigma_M = 0.12
Q_s^2. By the time t ~ 1/Q_s even small loops satisfy an area law. We describe
corrections to the propagator of semi-hard gluons at very early times in the
background of fluctuating magnetic fields.


title:
An Empirical Determination of the EBL and the Gamma-ray Opacity of the
  Universe

abstract:
  I present the results of a new approach to the intensity and photon density
spectrum of the intergalactic background light as a function of redshift using
observational data obtained in many different wavelength bands from local to
deep galaxy surveys. This enables an empirical determination of both the EBL
and its observationally based uncertainties. Using these results one can place
68% confidence upper and lower limits on the opacity of the universe to
{\gamma}-rays, free of the theoretical assumptions that were needed for past
calculations. I compare our results with measurements of the extragalactic
background light, upper limits obtained from observations made by the Fermi
Gamma-ray Space Telescope, and new observationally based results from Fermi and
H.E.S.S. using recent analyses of blazar spectra.


title: Short probabilistic proof of the Brascamp-Lieb and Barthe theorems

abstract:
  We give a short proof of the Brascamp-Lieb theorem, which asserts that a
certain general form of Young's convolution inequality is saturated by Gaussian
functions. The argument is inspired by Borell's stochastic proof of the
Pr\'ekopa-Leindler inequality and applies also to the reversed Brascamp-Lieb
inequality, due to Barthe.