title: Casimir Energies: Temperature Dependence, Dispersion, and Anomalies

abstract:
  Assuming the conventional Casimir setting with two thick parallel perfectly
conducting plates of large extent with a homogeneous and isotropic medium
between them, we discuss the physical meaning of the electromagnetic field
energy $W_{\rm disp}$ when the intervening medium is weakly dispersive but
nondissipative. The presence of dispersion means that the energy density
contains terms of the form $d[\omega\epsilon(\omega)] /d\omega$ and
$d[\omega\mu(\omega)] /d\omega$. We find that, as $W_{\rm disp}$ refers
thermodynamically to a non-closed physical system, it is {\it not} to be
identified with the internal thermodynamic energy $U$ following from the free
energy $F$, or the electromagnetic energy $W$, when the last-mentioned
quantities are calculated without such dispersive derivatives. To arrive at
this conclusion, we adopt a model in which the system is a capacitor, linked to
an external self-inductance $L$ such that stationary oscillations become
possible. Therewith the model system becomes a non-closed one. As an
introductory step, we review the meaning of the nondispersive energies, $F, U,$
and $W$. As a final topic, we consider an anomaly connected with local surface
divergences encountered in Casimir energy calculations for higher spacetime
dimensions, $D>4$, and discuss briefly its dispersive generalization. This kind
of application is essentially a generalization of the treatment of Alnes {\it
et al.} [J. Phys. A: Math. Theor. {\bf 40}, F315 (2007)] to the case of a
medium-filled cavity between two hyperplanes.


title: Self-* overload control for distributed web systems

abstract:
  Unexpected increases in demand and most of all flash crowds are considered
the bane of every web application as they may cause intolerable delays or even
service unavailability. Proper quality of service policies must guarantee rapid
reactivity and responsiveness even in such critical situations. Previous
solutions fail to meet common performance requirements when the system has to
face sudden and unpredictable surges of traffic. Indeed they often rely on a
proper setting of key parameters which requires laborious manual tuning,
preventing a fast adaptation of the control policies. We contribute an original
Self-* Overload Control (SOC) policy. This allows the system to self-configure
a dynamic constraint on the rate of admitted sessions in order to respect
service level agreements and maximize the resource utilization at the same
time. Our policy does not require any prior information on the incoming traffic
or manual configuration of key parameters. We ran extensive simulations under a
wide range of operating conditions, showing that SOC rapidly adapts to time
varying traffic and self-optimizes the resource utilization. It admits as many
new sessions as possible in observance of the agreements, even under intense
workload variations. We compared our algorithm to previously proposed
approaches highlighting a more stable behavior and a better performance.


title: A curve of nilpotent Lie algebras which are not Einstein nilradicals

abstract:
  The only known examples of noncompact Einstein homogeneous spaces are
standard solvmanifolds (special solvable Lie groups endowed with a left
invariant metric), and according to a long standing conjecture, they might be
all. The classification of Einstein solvmanifolds is equivalent to the one of
Einstein nilradicals, i.e. nilpotent Lie algebras which are nilradicals of the
Lie algebras of Einstein solvmanifolds. Up to now, there have been found very
few examples of graded nilpotent Lie algebras that can not be Einstein
nilradicals. In particular, in each dimension, there are only finitely many
known. We exhibit in the present paper two curves of pairwise non-isomorphic
9-dimensional 2-step nilpotent Lie algebras which are not Einstein nilradicals.


title:
Deep Fabry-Perot Halpha Observations of NGC 7793: a Very Extended Halpha
  Disk and a Truly Declining Rotation Curve

abstract:
  Deep Halpha observations of the Sculptor Group galaxy NGC 7793 were obtained
on the ESO 3.60m and the Marseille 36cm telescopes at La Silla, Chile. Halpha
emission is detected all the way to the edge of the HI disk, making of the HII
disk of NGC 7793 one of the largest ever observed in a quiet non-AGN late-type
system. Even in the very outer parts, the HII ionizing sources are probably
mainly internal (massive stars in the disk) with an unlikely contribution from
the extragalactic ionizing background. The Halpha kinematics confirms what had
already been seen with the HI observations: NGC 7793 has a truly declining
rotation curve. However, the decline is not Keplerian and a dark halo is still
needed to explain the rotation velocities in the outer parts.


title:
Quantum critical scaling in magnetic field near the Dirac point in
  graphene

abstract:
  Motivated by the recent measurement of the activation energy at the quantum
Hall state at the filling factor f=1 in graphene we discuss the scaling of the
interaction-induced gaps in vicinity of the Dirac point with the magnetic
field. The gap at f=1 is shown to be bounded from above by E(1)/C, where E(n)
are the Landau level energies and C = 5.985 + O(1/N) is a universal number. The
universal scaling functions are computed exactly for a large number of Dirac
fermions N. We find a sublinear dependence of the gap at the laboratory
magnetic fields for realistic values of short-range repulsion between
electrons, and in quantitative agreement with observation.


title:
Indications for 3 Mpc-scale large-scale structure associated with an
  X-ray luminous cluster of galaxies at z=0.95

abstract:
  X-ray luminous clusters of galaxies at z~1 are emerging as major cosmological
probes and are fundamental tools to study the cosmic large-scale structure and
environmental effects of galaxy evolution at large look-back times. We present
details of the newly-discovered galaxy cluster XMMU J0104.4-0630 at z=0.947 and
a probable associated system in the LSS environment. The clusters were found in
a systematic study for high-redshift systems using deep archival XMM-Newton
data for the serendipitous detection and the X-ray analysis, complemented by
optical/NIR imaging observations and spectroscopy of the main cluster. We find
a well-evolved, intermediate luminosity cluster with Lx=(6.4+-1.3)x10^43 erg/s
(0.5-2.0 keV) and strong central 1.4 GHz radio emission. The cluster galaxy
population exhibits a pronounced transition toward bluer colors at
cluster-centric distances of 1-2 core radii, consistent with an age difference
of 1-2 Gyr for a single burst solar metallicity model. The second, less evolved
X-ray cluster at a projected distance of 6.4 arcmin (~3 Mpc) and a concordant
red-sequence color likely forms a cluster-cluster bridge with the main target
as part of its surrounding large-scale structure at z~0.95.


title:
Preemptive vortex-loop proliferation in multicomponent interacting
  Bose--Einstein condensates

abstract:
  We use analytical arguments and large-scale Monte Carlo calculations to
investigate the nature of the phase transitions between distinct complex
superfluid phases in a two-component Bose--Einstein condensate when a
non-dissipative drag between the two components is being varied. We focus on
understanding the role of topological defects in various phase transitions and
develop vortex-matter arguments allowing an analytical description of the phase
diagram. We find the behavior of fluctuation induced vortex matter to be much
more complex and substantially different from that of single-component
superfluids. We propose and investigate numerically a novel drag-induced
``preemptive vortex loop proliferation'' transition. Such a transition may be a
quite generic feature in many multicomponent systems where symmetry is restored
by a gas of several kinds of competing vortex loops.


title:
Unveiling the Important Role of Groups in the Evolution of Massive
  Galaxies: Insights from an Infrared Passive Sequence at Intermediate Redshift

abstract:
  The most massive galaxies in the Universe are also the oldest. To overturn
this apparent contradiction with hierarchical growth models, we focus on the
group scale haloes which host most of these galaxies. A stellar mass selected
M_* >~ 2x10^10M_sol sample at z~0.4 is constructed within the CNOC2 redshift
survey. A sensitive Mid InfraRed (MIR) IRAC colour is used to isolate passive
galaxies. It produces a bimodal distribution, in which passive galaxies
(highlighted by morphological early-types) define a tight MIR colour sequence
(Infrared Passive Sequence, IPS). This is due to stellar atmospheric emission
from old stellar populations. Significantly offset from the IPS are galaxies
where reemission by dust boosts emission at 8microns (InfraRed-Excess or IRE
galaxies). They include all known morphological late-types. Comparison with
EW[OII] shows that MIR colour is highly sensitive to low levels of activity,
and allows us to separate dusty-active from passive galaxies. The fraction of
IRE galaxies, f(IRE) drops with M_*, such that f(IRE)=0.5 at a ``crossover
mass'' of ~1.3x10^11M_sol. Within our optically-defined group sample there is a
strong and consistent deficit in f(IRE) at all masses, and most clearly at M_*
>~10^11M_sol. Using a mock galaxy catalogue derived from the Millenium
Simulation we show that the observed trend of f(IRE) with M_* can be explained
if suppression of star formation occurs primarily in the group environment, and
particularly for M_*>~10^11M_sol galaxies. In this way, downsizing can be
driven solely by structure growth in the Universe.


title: Obtainable Sizes of Topologies on Finite Sets

abstract:
  We study the smallest possible number of points in a topological space having
k open sets. Equivalently, this is the smallest possible number of elements in
a poset having k order ideals. Using efficient algorithms for constructing a
topology with a prescribed size, we show that this number has a logarithmic
upper bound. We deduce that there exists a topology on n points having k open
sets, for all k in an interval which is exponentially large in n. The
construction algorithms can be modified to produce topologies where the
smallest neighborhood of each point has a minimal size, and we give a range of
obtainable sizes for such topologies.


title:
Monte Carlo Studies of Geomagnetic Field Effects on the Imaging Air
  Cherenkov Technique for the MAGIC Telescope Site

abstract:
  Imaging air Cherenkov telescopes (IACTs) detect the Cherenkov light from
extensive air showers (EAS) initiated by very high energy (VHE) gamma-rays
impinging on the Earth's atmosphere. Due to the overwhelming background from
hadron induced EAS, the discrimination of the rare gamma-like events is vital.
The influence of the geomagnetic field (GF) on the development of EAS can
further complicate the imaging air Cherenkov technique. The amount and the
angular distribution of Cherenkov light from EAS can be obtained by means of
Monte Carlo (MC) simulations. Here we present the results from dedicated MC
studies of GF effects on images from gamma-ray initiated EAS for the MAGIC
telescope site, where the GF strength is ~40 micro Tesla. The results from the
MC studies suggest that GF effects degrade not only measurements of very low
energy gamma-rays below ~100 GeV but also those at TeV-energies.


title: A Second Look at the Metal Line Variability of G29-38

abstract:
  The pulsating white dwarf G29-38 possesses a dust disk and metal lines
attributed to the accretion of its disk material. \citet{vonhipg29} have
reported variability in the equivalent width of G29-38's CaII K line on the
timescale of days. We use high resolution optical spectroscopy of G29-38's CaII
K line to test this observation. Over six days spanning in June 2007 and
October 2007 we see no evidence for variability in the equivalent width of the
Ca II K line. We also sample the variability of the Ca II K line over
integrated timescales of $\sim$100-500 seconds, where errors from incomplete
coverage of pulsation modes are predicted to be $\sim$8-15%. We find that the
scatter of the equivalent widths over this time period is consistent with
measurement errors at the 7% level, slightly weaker than predicted but within
the uncertainties of predictions. Weaker Ca and Mg lines observed show no
significant variability on yearly timescales over ten years based on our data
and other high resolution spectra. We conclude that further study is warranted
to verify if the accretion onto G29-38 is variable.


title: Ultracold atom-molecule collisions with fermionic atoms

abstract:
  Elastic and inelastic properties of weakly bound s- and p-wave molecules of
fermionic atoms that collide with a third atom are investigated. Analysis of
calculated collisional properties of s-wave dimers of fermions in different
spin states permit us to compare and highlight the physical mechanisms that
determine the stability of s-wave and p-wave molecules. In contrast to s-wave
molecules, the collisional properties of p-wave molecules are found to be
largely insensitive to variations of the p-wave scattering length and that
these collisions will usually result in short molecular lifetimes. We also
discuss the importance of this result for both theories and experiments
involving degenerate Fermi gases.


title: Free subgroups in groups acting on rooted trees

abstract:
  We show that if a group $G$ acting faithfully on a rooted tree $T$ has a free
subgroup, then either there exists a point $w$ of the boundary $\partial T$ and
a free subgroup of $G$ with trivial stabilizer of $w$, or there exists
$w\in\partial T$ and a free subgroup of $G$ fixing $w$ and acting faithfully on
arbitrarily small neighborhoods of $w$. This can be used to prove absence of
free subgroups for different known classes of groups. For instance, we prove
that iterated monodromy groups of expanding coverings have no free subgroups
and give another proof of a theorem by S. Sidki.


title:
Comments on the Hartree-Fock description of the Hooke's atom and
  suggestion for an accurate closed-form orbital

abstract:
  The ground-state Hartree-Fock (HF) wavefunction of the Hooke's atom is not
known in closed form, contrary to the exact solution. The single HF orbital
involved has thus far been studied using expansion techniques only, leading to
slightly disparate energies. Therefore, the present letter aims at proposing
alternative definitions of the HF wavefunction. First, the HF limit is
ascertained using a simple expansion, which makes it possible to formulate
explicit expressions of HF properties. The resulting energy, 2.038 438 871 8
Eh, is found stable at the tenth digit. Second and more instructive, an
analysis of the Hartree equation makes it possible to infer a remarkably simple
and accurate HF orbital, leading to an energy exceeding by 5.76 10-7 Eh only
the above HF limit. This orbital makes it possible to obtain (near)
Hartree-Fock properties in closed-form, which in turn enables handy comparisons
with exact quantities.


title:
The Five College Radio Astronomy Observatory CO Mapping Survey of the
  Taurus Molecular Cloud

abstract:
  The FCRAO Survey of the Taurus Molecular Cloud observed the 12CO and 13CO
J=1-0 emission from 98 square degrees of this important, nearby star forming
region. This set of data with 45" resolution comprises the highest spatial
dynamic range image of an individual molecular cloud constructed to date, and
provides valuable insights to the molecular gas distribution, kinematics, and
the star formation process. In this contribution, we describe the observations,
calibration, data processing, and characteristics of the noise and line
emission of the survey. The angular distribution of 12CO and 13CO emission over
1 km/s velocity intervals and the full velocity extent of the cloud are
presented. These reveal a complex, dynamic medium of cold, molecular gas.


title: Non-commutative Corrections in Spectral Matrix Gravity

abstract:
  We study a non-commutative deformation of general relativity based on
spectral invariants of a partial differential operator acting on sections of a
vector bundle over a smooth manifold. We compute the first non-commutative
corrections to Einstein equations in the weak deformation limit and analyze the
spectrum of the theory. Related topics are discussed as well.


title:
Relativistic Particle-In-Cell Simulation Studies of Prompt and Early
  Afterglows from GRBs

abstract:
  Nonthermal radiation observed from astrophysical systems containing
relativistic jets and shocks e.g. gamma-ray bursts (GRBs) active galactic
nuclei (AGNs) and microquasars commonly exhibit power-law emission spectra.
Recent PIC simulations of relativistic electron-ion (or electron-positron) jets
injected into a stationary medium show that particle acceleration occurs within
the downstream jet. In collisionless relativistic shocks particle (electron,
positron and ion) acceleration is due to plasma waves and their associated
instabilities (e.g. the Weibel (filamentation) instability) created in the
shock region. The simulations show that the Weibel instability is responsible
for generating and amplifying highly non-uniform small-scale magnetic fields.
These fields contribute to the electron's transverse deflection behind the jet
head. The resulting ``jitter'' radiation from deflected electrons has different
properties compared to synchrotron radiation which assumes a uniform magnetic
field. Jitter radiation may be important for understanding the complex time
evolution and/or spectra in gamma-ray bursts, relativistic jets in general and
supernova remnants.


title: Surface Effect on Domain Wall Width in Ferroelectrics

abstract:
  We study the effect of depolarization field related with inhomogeneous
polarization distribution, strain and surface energy parameters on a domain
wall profile near the surface of a ferroelectric film within the framework of
Landau-Ginzburg-Devonshire phenomenology. Both inhomogeneous elastic stress and
positive surface energy lead to the wall broadening at electrically screened
surface. For ferroelectrics with weak piezoelectric coupling, the extrapolation
length that defines surface energy parameter, affects the wall broadening more
strongly than inhomogeneous elastic stress. Unexpectedly, the domain wall
profile follows a long-range power law when approaching the surface, while it
saturates exponentially in the bulk. In materials with high piezoelectric
coupling and negligibly small surface energy (i.e. high extrapolation length)
inhomogeneous elastic stress effect dominates.


title: Equilibrium and non-equilibrium fluctuations in a glass-forming liquid

abstract:
  Glass-forming liquids display strong fluctuations -- dynamical
heterogeneities -- near their glass transition. By numerically simulating a
binary Weeks-Chandler-Andersen liquid and varying both temperature and
timescale, we investigate the probability distributions of two kinds of local
fluctuations in the non-equilibrium (aging) regime and in the equilibrium
regime; and find them to be very similar in the two regimes and across
temperatures. We also observe that, when appropriately rescaled, the integrated
dynamic susceptibility is very weakly dependent on temperature and very similar
in both regimes.


title:
Comments on the momentum density and the spatial form of the
  density-matrix of the Hooke's atom

abstract:
  In a recent paper, A. Akbari, N. H. March and A. Rubio [Phys. Rev. A. 76,
032510 (2007)] have investigated the one-electron reduced density-matrix and
the momentum density of several two-electron model atoms, including the Hooke's
atom. The method used by the authors for deriving an integral form of the
momentum density is well suited for deriving a closed-form expression of the
exact reciprocal form factor, which function is of importance inasmuch as it
reflects the off-diagonal side of the exact reduced density-matrix.


title: The big blue bump and soft X-ray excess of individual quasars

abstract:
  For 11 quasar, we find that the soft X-ray excess component is not
prolongation of the Big Blue Bump. Furthermore, adopting a theoretical
continuum that is absorbed by the appropriate amount of intrinsic dust, we are
able to reconcile this universal theoretical continuum with the UV break and
the softness problem. Para 11 quasares, encontramos que el exceso de rayos-X
suaves no es una prolongacion de la Gran Joroba Azul. Aun mas, adoptando un
continuo ionizante teorico absorbido por una cantidad diversa de polvo
intrinseco para cada quasar, podemos reconciliar este continuo teorico con el
quiebre UV con el problema de suavidad.


title: Meson Clouds and Nucleon Electromagnetic Form Factors

abstract:
  In contrast with common non-relativistic lore, the usual Sachs form factors
are not the Fourier transforms of charge or magnetization densities. Instead,
the two-dimensional Fourier transform of the electromagnetic $F_1$ form factor
is the charge charge density of partons in the transverse plane. An analysis of
the available data for neutron form factors leads to the result that the
neutron charge density is negative at the center, and that the square of the
transverse charge radius is positive. This contrasts with many expectations.
Additionally, the use of measured proton form factors leads to the result that
the proton's central $u$ quark charge density is larger than that of the $d$
quark by about 80%. The proton (neutron) charge density has a long range
positively (negatively) charged component indicative of a pion cloud.


title: Spectral Measure of Robustness in Complex Networks

abstract:
  We introduce the concept of natural connectivity as a robustness measure of
complex networks. The natural connectivity has a clear physical meaning and a
simple mathematical formulation. It characterizes the redundancy of alternative
paths by quantifying the weighted number of closed walks of all lengths. We
show that the natural connectivity can be derived mathematically from the graph
spectrum as an average eigenvalue and that it increases strictly monotonically
with the addition of edges. We test the natural connectivity and compare it
with other robustness measures within a scenario of edge elimination. We
demonstrate that the natural connectivity has an acute discrimination which
agrees with our intuition.


title:
Quadratic recurrence equations - exact explicit solution of period four
  fixed points functions in bifurcation diagram

abstract:
  This article presents the exact solution of fixed points functions for the
cycle of period four of the quadratic recurrence equations. The solution is
demonstrated for the quadratic map and the logistic map. These recurrence
equations, presenting the real domain, as well as the Mandelbrot set,
presenting the complex domain, are at the very heart of dynamical systems and
chaos theory. Up to now, the closed explicit solutions of fixed points
functions have only been known for three bifurcation ranges: for the cycles of
period one, two and three. With the discovery of the solution for cycle four,
disclosed in this paper, further step has been made in our comprehension of
simultaneous complexity and simplicity which represents the beauty of nature.


title:
The quantum $J_{1}$--$J_{1}'$--$J_{2}$ spin-1 Heisenberg model:
  Influence of the interchain coupling on the ground-state magnetic ordering in
  2D

abstract:
  We study the phase diagram of the isotropic $J_{1}$--$J_{1}'$--$J_{2}$
Heisenberg model for spin-1 particles on an anisotropic square lattice, using
the coupled cluster method. We find no evidence for an intermediate phase
between the N\'{e}el and stripe states, as compared with all previous results
for the corresponding spin-1/2 case. However, we find a quantum tricritical
point at $J_{1}'/J_{1} \approx0.66 \pm 0.03$, $J_{2}/J_{1} \approx0.35\pm0.02$,
where a line of second-order phase transitions between the quasi-classical
N\'{e}el and stripe-ordered phases (for $J_{1}'/J_{1} \lesssim 0.66$) meets a
line of first-order phase transitions between the same two states (for
$J_{1}'/J_{1} \gtrsim 0.66$)


title: On Nichols algebras over PGL(2,q) and PSL(2,q)

abstract:
  We compute necessary conditions on Yetter-Drinfeld modules over the groups
$\mathbf{PGL}(2,q)=\mathbf{PGL}(2,\FF_q)$ and
$\mathbf{PSL}(2,q)=\mathbf{PSL}(2,\FF_q)$ to generate finite dimensional
Nichols algebras. This is a first step towards a classification of pointed Hopf
algebras with group of group-likes isomorphic to one of these groups.
  As a by-product of the techniques developed in this work, we prove that there
is no non-trivial finite-dimensional pointed Hopf algebra over the Mathieu
groups $M_{20}$ and $M_{21}=\mathbf{PSL}(3,4)$.


title:
Colored Resonances at the Tevatron: Phenomenology and Discovery
  Potential in Multijets

abstract:
  There exist several classes of theories beyond the Standard Model which
contain massive spin-1 color octets, generically called "colorons". Indeed we
argue that colorons inevitably appear in the spectrum whenever new colored
particles feel an additional confining force. Colorons are distinctive at
hadron colliders as this is the only environment in which they can be
resonantly produced. In the simplest models we show that the coloron naturally
decays to multijets via secondary resonances, which can be consistent with all
existing bounds, even for colorons as light as a few hundred GeV. We perform
representative case studies and show that a search in the four-jet channel at
the Tevatron has strong signal significance, while the LHC faces formidable
challenges for such a search.


title: Coulomb Resummation and Monopole Masses

abstract:
  The relativistic Coulomb resummation factor suggested by I.L. Solovtsov is
used to reanalyze the mass limits obtained for magnetic monopoles which might
have been produced at the Fermilab Tevatron. The limits given by the Oklahoma
experiment (Fermilab E882) are pushed close to the unitary bounds, so that the
lower limits on monopole masses are increased from around 250 GeV to about 400
GeV.


title: Canonical measures and Kahler-Ricci flow

abstract:
  We show that the Kahler-Ricci flow on an algebraic manifold of positive
Kodaira dimension and semi-ample canonical line bundle converges to a unique
canonical metric on its canonical model. It is also shown that there exists a
canonical measure of analytic Zariski decomposition on an algebraic manifold of
positive Kodaira dimension. Such a canonical measure is unique and invariant
under birational transformations under the assumption of the finite generation
of canonical rings.


title:
Electrodynamics of Magnetars III: Pair Creation Processes in an
  Ultrastrong Magnetic Field and Particle Heating in a Dynamic Magnetosphere

abstract:
  We consider the details of the QED processes that create electron-positron
pairs in magnetic fields approaching and exceeding 10^{14} G. The formation of
free and bound pairs is addressed, and the importance of positronium
dissociation by thermal X-rays is noted. We calculate the collision cross
section between an X-ray and a gamma ray, and point out a resonance in the
cross section when the gamma ray is close to the threshold for pair conversion.
We also discuss how the pair creation rate in the open-field circuit and the
outer magnetosphere can be strongly enhanced by instabilities near the light
cylinder. When the current has a strong fluctuating component, a cascade
develops. We examine the details of particle heating, and show that a high rate
of pair creation can be sustained close to the star, but only if the spin
period is shorter than several seconds. The dissipation rate in this turbulent
state can easily accommodate the observed radio output of the transient
radio-emitting magnetars, and even their infrared emission. Finally, we outline
how a very high rate of pair creation on the open magnetic field lines can help
to stabilize a static twist in the closed magnetosphere and to regulate the
loss of magnetic helicity by reconnection at the light cylinder.


title:
Electrodynamics of Magnetars IV: Self-Consistent Model of the Inner
  Accelerator, with Implications for Pulsed Radio Emission

abstract:
  We consider the voltage structure in the open-field circuit and outer
magnetosphere of a magnetar. The standard polar-cap model for radio pulsars is
modified significantly when the polar magnetic field exceeds 1.8x10^{14} G.
Pairs are created by accelerated particles via resonant scattering of thermal
X-rays, followed by the nearly instantaneous conversion of the scattered photon
to a pair. A surface gap is then efficiently screened by e+- creation, which
regulates the voltage in the inner part of the circuit to ~10^9 V. We also
examine the electrostatic gap structure that can form when the magnetic field
is somewhat weaker, and deduce a voltage 10-30 times larger over a range of
surface temperatures. We examine carefully how the flow of charge back to the
star above the gap depends on the magnitude of the current that is extracted
from the surface of the star, on the curvature of the magnetic field lines, and
on resonant drag. The rates of different channels of pair creation are
determined self-consistently, including the non-resonant scattering of X-rays,
and collisions between gamma rays and X-rays. We find that the electrostatic
gap solution has too small a voltage to sustain the observed pulsed radio
output of magnetars unless i) the magnetic axis is nearly aligned with the
rotation axis and the light of sight; or ii) the gap is present on the closed
as well as the open magnetic field lines. Several properties of the radio
magnetars -- their rapid variability, broad pulses, and unusually hard radio
spectra -- are consistent with a third possibility, that the current in the
outer magnetosphere is strongly variable, and a very high rate of pair creation
is sustained by a turbulent cascade.


title: Mean-field dynamics of a Bose Josephson junction in an optical cavity

abstract:
  We study the mean-field dynamics of a Bose Josephson junction which is
dispersively coupled to a single mode of a high-finesse optical cavity. An
effective classical Hamiltonian for the Bose Josephson junction is derived and
its dynamics is studied in the perspective of phase portrait. It is shown that
the strong condensate-field coupling does alter the dynamics of the Bose
Josephson junction drastically. The possibility of coherent manipulating and
\textsl{in situ} observation of the dynamics of the Bose Josephson junction is
discussed.


title: The minimal set of Ingleton inequalities

abstract:
  The Ingleton-LP bound is an outer bound for the multicast capacity region,
assuming the use of linear network codes. Computation of the bound is performed
on a polyhedral cone obtained by taking the intersection of half-spaces induced
by the basic (Shannon-type) inequalities and Ingleton inequalities. This paper
simplifies the characterization of this cone, by obtaining the unique minimal
set of Ingleton inequalities. As a result, the effort required for computation
of the Ingleton-LP bound can be greatly reduced.


title: Pants immersed in hyperbolic 3-manifolds

abstract:
  We show that an immersed thrice-punctured sphere in a cusped orientable
hyperbolic 3-manifold is either embedded or has a single clasp in a manifold
obtained by hyperbolic Dehn filling on a cusp of the Whitehead link complement.


title: Simplicial matrix-tree theorems

abstract:
  We generalize the definition and enumeration of spanning trees from the
setting of graphs to that of arbitrary-dimensional simplicial complexes
$\Delta$, extending an idea due to G. Kalai. We prove a simplicial version of
the Matrix-Tree Theorem that counts simplicial spanning trees, weighted by the
squares of the orders of their top-dimensional integral homology groups, in
terms of the Laplacian matrix of $\Delta$. As in the graphic case, one can
obtain a more finely weighted generating function for simplicial spanning trees
by assigning an indeterminate to each vertex of $\Delta$ and replacing the
entries of the Laplacian with Laurent monomials. When $\Delta$ is a shifted
complex, we give a combinatorial interpretation of the eigenvalues of its
weighted Laplacian and prove that they determine its set of faces uniquely,
generalizing known results about threshold graphs and unweighted Laplacian
eigenvalues of shifted complexes.


title: Heavy-tailed statistics in short-message communication

abstract:
  Short-message (SM) is one of the most frequently used communication channels
in the modern society. In this Brief Report, based on the SM communication
records provided by some volunteers, we investigate the statistics of SM
communication pattern, including the interevent time distributions between two
consecutive short messages and two conversations, and the distribution of
message number contained by a complete conversation. In the individual level,
the current empirical data raises a strong evidence that the human activity
pattern, exhibiting a heavy-tailed interevent time distribution, is driven by a
non-Poisson nature.


title: Gamma-Ray Bursts, new cosmological beacons

abstract:
  Long Gamma-Ray Bursts (GRBs) are the brightest electromagnetic explosions in
the Universe, associated to the death of massive stars. As such, GRBs are
potential tracers of the evolution of the cosmic massive star formation,
metallicity, and Initial Mass Function. GRBs also proved to be appealing
cosmological distance indicators. This opens a unique opportunity to constrain
the cosmic expansion history up to redshifts 5-6. A brief review on both
subjects is presented here.


title:
Centrality dependence of $p_{T}$ spectra for identified hadrons in Au+Au
  and Cu+Cu collisions at $\sqrt{s_{NN}}= 200$ GeV

abstract:
  The centrality dependence of transverse momentum spectra for identified
hadrons at midrapidity in Au+Au collisions at $\sqrt{s_{NN}}= 200$ GeV is
systematically studied in a quark combination model. The $\mathrm{{p}_{T}}$
spectra of $\pi^{\pm}$, $K^{\pm}$, $p(\bar{p})$ and $\Lambda(\bar{\Lambda})$ in
different centrality bins and the nuclear modification factors ($R_{CP}$) for
these hadrons are calculated. The centrality dependence of the average
collective transverse velocity $<\beta (r)>$ for the hot and dense quark matter
is obtained in Au+Au collisions, and it is applied to a relative smaller Cu+Cu
collision system. The centrality dependence of $\mathrm{{p}_{T}}$ spectra and
the $R_{CP}$ for $\pi^{0}$, $K_{s}^{0}$ and $\Lambda$ in Cu+Cu collisions at
$\sqrt{s_{NN}}= 200$ GeV are well described. The results show that $<\beta
(r)>$ is only a function of the number of participants $N_{part}$ and it is
independent of the collision system.


title: 3-Dimensional Schlaefli Formula and Its Generalization

abstract:
  Several identities similar to the Schlaefli formula are established for
tetrahedra in a space of constant curvature.


title:
A Localization Approach to Improve Iterative Proportional Scaling in
  Gaussian Graphical Models

abstract:
  We discuss an efficient implementation of the iterative proportional scaling
procedure in the multivariate Gaussian graphical models. We show that the
computational cost can be reduced by localization of the update procedure in
each iterative step by using the structure of a decomposable model obtained by
triangulation of the graph associated with the model. Some numerical
experiments demonstrate the competitive performance of the proposed algorithm.


title: Flavorful Supersymmetry from Higher Dimensions

abstract:
  We present models of flavorful supersymmetry in higher dimensions. The Higgs
fields and the supersymmetry breaking field are localized in the same place in
the extra dimension(s). The Yukawa couplings and operators generating the
supersymmetry breaking parameters then receive the same suppression factors
from the wavefunction profiles of the matter fields, leading to a specific
correlation between these two classes of interactions. The resulting
phenomenology is very rich, while stringent experimental constraints from the
low-energy flavor and CP violating processes can all be satisfied. We construct
both unified and non-unified models in this framework, which can be either
strongly or weakly coupled at the cutoff scale. We analyze one version in
detail, a strongly coupled unified model, which addresses various issues of
supersymmetric grand unification. The models presented here provide an explicit
example in which the supersymmetry breaking spectrum can be a direct window
into the physics of flavor at a very high energy scale.


title: The Phantom Bounce: A New Proposal for an Oscillating Cosmology

abstract:
  An oscillating universe cycles through a series of expansions and
contractions. We propose a model in which ``phantom'' energy with a
supernegative pressure ($p < - \rho$) grows rapidly and dominates the late-time
expanding phase. The universe's energy density is then so large that the
effects of quantum gravity are important at both the beginning and the end of
each expansion (or contraction). The bounce can be caused by high energy
modifications to the Friedmann equation governing the expansion of the
universe, which make the cosmology nonsingular. The classic black hole
overproduction of oscillating universes is resolved due to their destruction by
the phantom energy.


title: A Theoretical Framework for R-parity Violation

abstract:
  We propose a theoretical framework for R-parity violation. It is realized by
a class of Calabi--Yau compactification of Heterotic string theory. Trilinear
R-parity violation in superpotential is either absent or negligibly small
without an unbroken symmetry, due to a selection rule based on charge counting
of a spontaneously broken U(1) symmetry. Although such a selection rule cannot
be applied in general to non-renormalizable operators in the low-energy
effective superpotential, it is valid for terms trilinear in low-energy degrees
of freedom, and hence can be used as a solution to the dimension-4 proton decay
problem in the minimal supersymmetric standard model. Bilinear R-parity
violation is generated, but there are good reasons why they are small enough to
satisfy its upper bounds from neutrino mass and washout of baryon/lepton
asymmetry. All R-parity violating dimension-5 operators can be generated. In
this theoretical framework, nucleons can decay through squark-exchange diagrams
combining dimension-5 and bilinear R-parity violating operators. B-L breaking
neutron decay is predicted.


title: Connect sum and transversely non simple knots

abstract:
  We prove that transversal non-simplicity is preserved under taking connect
sum, generalizing Vertesi's result.


title:
The New Symmetries Beyond the Standard Model (The Body-centred Cubic
  Periodic Symmetries in Particle Physics)

abstract:
  This paper proposes new symmetries (the body-centred cubic periodic
symmetries) beyond the standard model. Using a free particle expanded
Schrodinger equation with the body-centred cubic periodic symmetry condition,
the paper deduces a full baryon spectrum (including mass M, I, S, C, B, Q, J
and P) of all 116 observed baryons. All quantum numbers of all deduced baryons
are completely consistent with the corresponding experimental results. The
deduced masses of all 116 baryons agree with (more than average 98 percent) the
experimental baryon masses using only four constant parameters. The
body-centred cubic periodic symmetries with a periodic constant ``a'' about
$10^{-23}$m play a crucial rule. The results strongly suggest that the new
symmetries really exist. This paper predicts some kind of ``Zeeman effect'' of
baryons, for example: one experimental baryon N(1720)${3/2}^{+}$ with $ \Gamma$
= 200 Mev is composed of two N baryons [(N(1659)${3/2}^{+}$ +
N(1839)${3/2}^{+}$] = $\bar{N(1749)}$${3/2}^{+}$ with $\Gamma$ = 1839-1659 =
180 Mev.


title: Order-Optimal Consensus through Randomized Path Averaging

abstract:
  Gossip algorithms have recently received significant attention, mainly
because they constitute simple and robust message-passing schemes for
distributed information processing over networks. However for many topologies
that are realistic for wireless ad-hoc and sensor networks (like grids and
random geometric graphs), the standard nearest-neighbor gossip converges as
slowly as flooding ($O(n^2)$ messages).
  A recently proposed algorithm called geographic gossip improves gossip
efficiency by a $\sqrt{n}$ factor, by exploiting geographic information to
enable multi-hop long distance communications. In this paper we prove that a
variation of geographic gossip that averages along routed paths, improves
efficiency by an additional $\sqrt{n}$ factor and is order optimal ($O(n)$
messages) for grids and random geometric graphs.
  We develop a general technique (travel agency method) based on Markov chain
mixing time inequalities, which can give bounds on the performance of
randomized message-passing algorithms operating over various graph topologies.


title:
Entanglement purification without controlled-NOT gates by using the
  natural dynamics of spin chains

abstract:
  We present a simple protocol to purify bipartite entanglement in spin-1/2
particles by utilizing only natural spin-spin interactions, i.e. those that can
commonly be realized in realistic physical systems, and S_z-measurements on
single spins. Even the standard isotropic Heisenberg interaction is shown to be
sufficient to purify mixed state entanglement if there are at least three pairs
of spins. This approach could be useful for quantum information processing in
solid-state-based systems.


title: T-adic exponential sums over finite fields

abstract:
  $T$-adic exponential sums associated to a Laurent polynomial $f$ are
introduced. They interpolate all classical $p^m$-power order exponential sums
associated to $f$. The Hodge bound for the Newton polygon of $L$-functions of
$T$-adic exponential sums is established. This bound enables us to determine,
for all $m$, the Newton polygons of $L$-functions of $p^m$-power order
exponential sums associated to an $f$ which is ordinary for $m=1$. Deeper
properties of $L$-functions of $T$-adic exponential sums are also studied.
Along the way, new open problems about the $T$-adic exponential sum itself are
discussed.


title:
Planetary Companions around Three Intermediate-Mass G and K Giants: 18
  Del, xi Aql, and HD 81688

abstract:
  We report the detection of 3 new extrasolar planets from the precise Doppler
survey of G and K giants at Okayama Astrophysical Observatory. The host stars,
namely, 18 Del (G6 III), xi Aql (K0 III) and HD 81688 (K0 III-IV), are located
at the clump region on the HR diagram with estimated masses of 2.1-2.3 M_solar.
18 Del b has a minimum mass of 10.3 M_Jup and resides in a nearly circular
orbit with period of 993 days, which is the longest one ever discovered around
evolved stars. xi Aql b and HD 81688 b have minimum masses of 2.8 and 2.7
M_Jup, and reside in nearly circular orbits with periods of 137 and 184 days,
respectively, which are the shortest ones among planets around evolved stars.
All of the substellar companions ever discovered around possible
intermediate-mass (1.7-3.9 M_solar) clump giants have semimajor axes larger
than 0.68 AU, suggesting the lack of short-period planets. Our numerical
calculations suggest that Jupiter-mass planets within about 0.5 AU (even up to
1 AU depending on the metallicity and adopted models) around 2-3 M_solar stars
could be engulfed by the central stars at the tip of RGB due to tidal torque
from the central stars. Assuming that most of the clump giants are post-RGB
stars, we can not distinguish whether the lack of short-period planets is
primordial or due to engulfment by central stars. Deriving reliable mass and
evolutionary status for evolved stars is highly required for further
investigation of formation and evolution of planetary systems around
intermediate-mass stars.


title: Studying a dual-species BEC with tunable interactions

abstract:
  We report on the observation of controllable spatial separation in a
dual-species Bose-Einstein condensate (BEC) with $^{85}$Rb and $^{87}$Rb.
Interparticle interactions between the different components can change the
miscibility of the two quantum fluids. In our experiments, we clearly observe
the immiscible nature of the two simultaneously Bose-condensed species via
their spatial separation. Furthermore the $^{85}$Rb Feshbach resonance near 155
G is used to change them between miscible and immiscible by tuning the
$^{85}$Rb scattering length. Our apparatus is also able to create $^{85}$Rb
condensates with up to $8\times10^4$ atoms which represents a significant
improvement over previous work.


title: On the Shuffling Algorithm for Domino Tilings

abstract:
  We study the dynamics of a certain discrete model of interacting particles
that comes from the so called shuffling algorithm for sampling a random tiling
of an Aztec diamond. It turns out that the transition probabilities have a
particularly convenient determinantal form. An analogous formula in a
continuous setting has recently been obtained by Jon Warren studying certain
model of interlacing Brownian motions which can be used to construct Dyson's
non-intersecting Brownian motion.
  We conjecture that Warren's model can be recovered as a scaling limit of our
discrete model and prove some partial results in this direction. As an
application to one of these results we use it to rederive the known result that
random tilings of an Aztec diamond, suitably rescaled near a turning point,
converge to the GUE minor process.


title: Determination of f_0(980) Structure by Fragmentation Functions

abstract:
  We discuss internal structure of an exotic hadron by using fragmentation
functions. The fragmentation functions for the f_0(980) meson are obtained by a
global analysis of e^++e^- \to f_0+X data. Quark configuration of the f_0(980)
could be determined by peak positions and second moments of the obtained
fragmentation functions.


title: Guarding curvilinear art galleries with vertex or point guards

abstract:
  One of the earliest and most well known problems in computational geometry is
the so-called art gallery problem. The goal is to compute the minimum possible
number guards placed on the vertices of a simple polygon in such a way that
they cover the interior of the polygon.
  In this paper we consider the problem of guarding an art gallery which is
modeled as a polygon with curvilinear walls. Our main focus is on polygons the
edges of which are convex arcs pointing towards the exterior or interior of the
polygon (but not both), named piecewise-convex and piecewise-concave polygons.
We prove that, in the case of piecewise-convex polygons, if we only allow
vertex guards, $\lfloor\frac{4n}{7}\rfloor-1$ guards are sometimes necessary,
and $\lfloor\frac{2n}{3}\rfloor$ guards are always sufficient. Moreover, an
$O(n\log{}n)$ time and O(n) space algorithm is described that produces a vertex
guarding set of size at most $\lfloor\frac{2n}{3}\rfloor$. When we allow point
guards the afore-mentioned lower bound drops down to
$\lfloor\frac{n}{2}\rfloor$. In the special case of monotone piecewise-convex
polygons we can show that $\lfloor\frac{n}{2}\rfloor$ vertex guards are always
sufficient and sometimes necessary; these bounds remain valid even if we allow
point guards.
  In the case of piecewise-concave polygons, we show that $2n-4$ point guards
are always sufficient and sometimes necessary, whereas it might not be possible
to guard such polygons by vertex guards. We conclude with bounds for other
types of curvilinear polygons and future work.


title: Coupled oscillators as models of quintom dark energy

abstract:
  We investigate quintom cosmology in FRW universes using isomorphic models
consisting of three coupled oscillators, one of which carries negative kinetic
energy. In particular, we examine the cosmological paradigms of
minimally-coupled massless quintom, of two conformally-coupled massive scalars
and of conformally-coupled massive quintom, and we obtain their qualitative
characteristics as well as their quantitative asymptotic behavior. For open or
flat geometries, we find that, independently of the specific initial
conditions, the universe is always led to an eternal expansion.


title:
Coarse differentiation and quasi-isometries of a class of solvable Lie
  groups I

abstract:
  This is the first of two papers which aim to understand quasi-isometries of a
subclass of unimodular split solvable Lie groups. In the present paper, we show
that locally (in a coarse sense), a quasi-isometry between two groups in this
subclass is close to a map that respects their group structures.


title: The eigenvalues of the Laplacian on domains with small slits

abstract:
  We introduce a small slit into a planar domain and study the resulting effect
upon the eigenvalues of the Laplacian. In particular, we show that as the
length of the slit tends to zero, each real-analytic eigenvalue branch tends to
an eigenvalue of the original domain. By combining this with our earlier work
(arXiv:math/0703616), we obtain the following application: The generic multiply
connected polygon has simple spectrum.


title:
Centrality, system size and energy dependences of charged-particle
  pseudo-rapidity distribution

abstract:
  Utilizing the three-fireball picture within the quark combination model, we
study systematically the charged particle pseudorapidity distributions in both
Au+Au and Cu+Cu collision systems as a function of collision centrality and
energy, $\sqrt{s_{NN}}=$ 19.6, 62.4, 130 and 200 GeV, in full pseudorapidity
range. We find that: (i)the contribution from leading particles to
$dN_{ch}/d\eta$ distributions increases with the decrease of the collision
centrality and energy respectively; (ii)the number of the leading particles is
almost independent of the collision energy, but it does depend on the nucleon
participants $N_{part}$; (iii)if Cu+Cu and Au+Au collisions at the same
collision energy are selected to have the same $N_{part}$, the resulting of
charged particle $dN/d\eta$ distributions are nearly identical, both in the
mid-rapidity particle density and the width of the distribution. This is true
for both 62.4 GeV and 200 GeV data. (iv)the limiting fragmentation phenomenon
is reproduced. (iiv) we predict the total multiplicity and pseudorapidity
distribution for the charged particles in Pb+Pb collisions at $\sqrt{s_{NN}}=
5.5$ TeV. Finally, we give a qualitative analysis of the $N_{ch}/<N_{part}/2>$
and $dN_{ch}/d\eta/<N_{part}/2>|_{\eta\approx0}$ as function of $\sqrt{s_{NN}}$
and $N_{part}$ from RHIC to LHC.


title:
Small dimensional microstrips embedded with ferromagnetic layers:
  Numerical simulations and experimental results

abstract:
  We use a numerical electromagnetic simulation software to investigate a
filtering device consisting of a small dimensional microstrips embedded with a
thin layer of ferromagnetic material and we compare our results to experimental
results. We are able to show good correlation of simulation versus experiment
for the magnitude of insertion loss and phase shift. The microstrips considered
have dimensions on the order of the skin depth of the conductor and hence the
field distribution is not easily calculated by analytic methods. We show that
numerical simulation methods provide an accurate means of characterizing these
structures.


title: Anomalous Monopole In an Interacting Boson System

abstract:
  Anomalous monopole of disk shape is found to exist in the semiclassical
theory of a two-mode interacting boson system. The quantum origin of this
anomaly is the collapsing or bundling of field lines of Berry curvature caused
by the interaction between bosons in the semiclassical limit. The significance
of this anomalous monopole is twofold: (1) it signals the failure of the von
Neumann-Wigner theorem in the semiclassical limit; (2) it indicates a breakdown
of the correspondence principle between quantum and classical dynamics.


title:
A quasi-monomode guided atom-laser from an all-optical Bose-Einstein
  condensate

abstract:
  We report the achievement of an optically guided and quasi-monomode atom
laser, in all spin projection states ($m_F =$ -1, 0 and $+1$) of F=1 in
Rubidium 87. The atom laser source is a Bose-Einstein condensate (BEC) in a
crossed dipole trap, purified to any one spin projection state by a
spin-distillation process applied during the evaporation to BEC. The atom laser
is outcoupled by an inhomogenous magnetic field, applied along the waveguide
axis. The mean excitation number in the transverse modes is $<n > = 0.65 \pm
0.05$ for $m_F = 0 $ and $<n > = 0.8 \pm 0.3$ for the low field seeker $m_F =
-1$.


title:
Hamiltonian description of a self-consistent interaction between charged
  particles and electromagnetic waves

abstract:
  The Hamiltonian description of the self-consistent interaction between an
electromagnetic plane-wave and a co-propagating beam of charged particles is
considered. We show how the motion can be reduced to a one-dimensional
Hamiltonian model (in a canonical setting) from the Vlasov-Maxwell Poisson
brackets. The reduction to this paradigmatic Hamiltonian model is performed
using a Lie algebraic formalism which allows us to remain Hamiltonian at each
step of the derivation.


title:
A Markov Basis for Conditional Test of Common Diagonal Effect in
  Quasi-Independence Model for Square Contingency Tables

abstract:
  In two-way contingency tables we sometimes find that frequencies along the
diagonal cells are relatively larger(or smaller) compared to off-diagonal
cells, particularly in square tables with the common categories for the rows
and the columns. In this case the quasi-independence model with an additional
parameter for each of the diagonal cells is usually fitted to the data. A
simpler model than the quasi-independence model is to assume a common
additional parameter for all the diagonal cells. We consider testing the
goodness of fit of the common diagonal effect by Markov chain Monte Carlo
(MCMC) method. We derive an explicit form of a Markov basis for performing the
conditional test of the common diagonal effect. Once a Markov basis is given,
MCMC procedure can be easily implemented by techniques of algebraic statistics.
We illustrate the procedure with some real data sets.


title:
Three-dimensional radiative transfer models of clumpy tori in Seyfert
  galaxies

abstract:
  Tori of Active Galactic Nuclei are made up of a mixture of hot and cold gas,
as well as dust. In order to protect the dust grains from destruction by the
hot gas as well as by the energetic radiation of the accretion disk, the dust
is often assumed to be distributed in clouds. In our new 3D model of AGN dust
tori, the torus is modelled as a wedge-shaped disk in which dusty clouds are
randomly distributed, by taking the dust density distribution of the
corresponding continuous model into account. We especially concentrate on the
differences between clumpy and continuous models in terms of the temperature
distributions, the surface brightness distributions and interferometric
visibilities, as well as spectral energy distributions. To this end, we employ
radiative transfer calculations with the help of the 3D Monte Carlo code MC3D.
In a second step, interferometric visibilities are calculated from the
simulated surface brightness distributions, which can be directly compared to
observations with the MIDI instrument. The radial temperature distributions of
clumpy models possess significantly enhanced scatter compared to the continuous
cases. Even at large distances, clouds can be heated directly by the central
accretion disk. The existence of the silicate 10 micron-feature in absorption
or in emission depends sensitively on the distribution, the size and optical
depth of clouds in the innermost part of the torus, due to shadowing effects of
clouds there. This explains failure and success of previous modelling efforts
of clumpy tori. After adapting the parameters of our clumpy standard model to
the circumstances of the Seyfert 2 Circinus galaxy, it can qualitatively
explain recent mid-infrared interferometric observations performed with MIDI,
as well as high resolution spectral data.


title: Sensitivity of Quantum Motion to Perturbation in Triangle Map

abstract:
  We study quantum Loschmidt echo, or fidelity, in the triangle map whose
classical counterpart has linear instability and weak chaos. Numerically, three
regimes of fidelity decay have been found with respect to the perturbation
strength $\epsilon$. In the regime of weak perturbation, the fidelity decays as
$\exp (-c\epsilon^2 t^{\gamma})$ with $\gamma \simeq 1.7$. In the regime of
strong perturbation, the fidelity is approximately a function of $\epsilon
t^{2.5}$, which is predicted for the classical fidelity [G. Casati, {\it et
al}, Phys.Rev.Lett.{\bf 94}, 114101 (2005)], and decays slower than power-law
decay for long times. In an intermediate regime, the fidelity has approximately
an exponential decay $\exp (-c' \epsilon t)$.


title:
Two Kinds of Iterative Solutions for Generalized Sombrero-shaped
  Potential in $N$-dimensional Space

abstract:
  Based on two different iteration procedures the groundstate wave functions
and energies for N-dimensional generalized Sombrero-shaped potentials are
solved. Two kinds of trial functions for the iteration procedure are defined.
The iterative solutions are convergent nicely to consistent results for
different choices of iteration procedures and trial functions.


title:
On the linear theory of Kelvin-Helmholtz instabilities of relativistic
  magnetohydrodynamic planar flows

abstract:
  We investigate the linear stability properties of the plane interface
separating two relativistic magnetized flows in relative motion. The two flows
are governed by the (special) relativistic equations for a magnetized perfect
gas in the infinite conductivity approximation. By adopting the vortex-sheet
approximation, the relativistic magnetohydrodynamics equations are linearized
around the equilibrium state and the corresponding dispersion relation is
derived and discussed. The behavior of the configuration and the regimes of
instability are investigated following the effects of four physical parameters,
namely: the flow velocity, the relativistic and Alfv\'enic Mach numbers and the
inclination of the wave vector on the plane of the interface. From the
numerical solution of the dispersion relation, we find in general two separate
regions of instability, associated respectively with the slow and fast
magnetosonic modes. Modes parallel to the flow velocity are destabilized only
for sufficiently low magnetization. For the latter case, stabilization is
attained, additionally, at sufficiently large relativistic velocities between
the two flows in relative motion. The relevance of these results to the study
of the stability of astrophysical jets is briefly commented.


title: Shell-model studies on exotic nuclei around 132Sn

abstract:
  The study of exotic nuclei around 132Sn is a subject of current experimental
and theoretical interest. Experimental information for nuclei in the vicinity
of 132Sn, which have been long inaccessible to spectroscopic studies, is now
available thanks to new advanced facilities and techniques. The experimental
data which have been now become available for these neutron-rich nuclei may
suggest a modification in the shell structure. They are, in fact, somewhat
different from what one might expect by extrapolating the existing results for
N<82, and as a possible explanation a change in the single-proton level scheme
has been suggested. The latter would be caused by a more diffuse nuclear
surface, and could be seen as a precursor of major effects which should show up
at larger neutron excess. New data offer therefore the opportunity to test the
shell model and look for a possible evolution of shell structure when going
toward neutron drip line. This is stimulating shell-model studies in this
region. Here, we present an overview of recent shell-model studies of 132Sn
neighbors, focusing attention on those calculations employing realistic
effective interactions.


title: NLTE study of scandium in the Sun

abstract:
  We investigate the formation of neutral and singly ionized scandium lines in
the solar photospheres. The research is aimed derive solar $\log
gf\epsilon_{\odot}$(Sc) values for scandium lines, which will later be used in
differential abundance analyses of metal-poor stars. Extensive statistical
equilibrium calculations were carried out for a model atom, which comprises 92
terms for \ion{Sc}{i} and 79 for \ion{Sc}{ii}. Photoionization cross-sections
are assumed to be hydrogenic. Synthetic line profiles calculated from the level
populations according to the NLTE departure coefficients were compared with the
observed solar spectral atlas. Hyperfine structure (HFS) broadening is taken
into account. The statistical equilibrium of scandium is dominated by a strong
underpopulation of \ion{Sc}{i} caused by missing strong lines. It is nearly
unaffected by the variation in interaction parameters and only marginally
sensitive to the choice of the solar atmospheric model. Abundance
determinations using the ODF model lead to a solar Sc abundance of between
$\log\epsilon_\odot = 3.07$ and 3.13, depending on the choice of $f$ values.
The long known difference between photospheric and meteoritic scandium
abundances is confirmed for the experimental $f$-values.


title:
The Brightness of the Galactic Radio Loops at 1420 MHz: Some Indications
  for the Existence of Loops V and VI

abstract:
  In this article we use 1420 MHz data to demonstrate the likely reality of
Galactic radio Loops V and VI. We further estimate distances and spectral
indices for both these and the four main radio loops. In the cases of Loops I -
IV, radio spectral indices are calculated from the mean brightnesses at 1420
and 820/404 MHz. The spectral indices of Loops V and VI are obtained from $T -
T$ plots between 1420 and 408 MHz. Using the supernova remnant (SNR) hypothesis
for the origin of radio loops, distances are calculated from the surface
brightnesses and the angular diameters at 1420 MHz. We also study how results
for brightnesses and distances of radio loops agree with current theories of
SNR evolution. For this purpose, the ambient density and initial explosion
energy of the loops are discussed. We also discuss applications of different
$\Sigma - D$ relations. The results obtained confirm a non-thermal origin and
nearby locations for the Galactic radio loops. Therefore, we have indications
that they are very old SNRs that evolve in low ambient densities, with high
initial explosion energies.


title: Comparison of estimates for dispersive equations

abstract:
  This paper describes a new comparison principle that can be used for the
comparison of space-time estimates for dispersive equations. In particular,
results are applied to the global smoothing estimates for several classes of
dispersive partial differential equations.


title: On Subgraph Isomorphism

abstract:
  Article explicitly expresses Subgraph Isomorphism by a polynomial size
asymmetric linear system.


title:
The Blue Straggler population in the globular cluster M53 (NGC5024): a
  combined HST, LBT, CFHT study

abstract:
  We used a proper combination of multiband high-resolution and wide field
multi-wavelength observations collected at three different telescopes (HST, LBT
and CFHT) to probe Blue Straggler Star (BSS) populations in the globular
cluster M53. Almost 200 BSS have been identified over the entire cluster
extension. The radial distribution of these stars has been found to be bimodal
(similarly to that of several other clusters) with a prominent dip at ~60'' (~2
r_c) from the cluster center. This value turns out to be a factor of two
smaller than the radius of avoidance (r_avoid, the radius within which all the
stars of ~1.2 M_sun have sunk to the core because of dynamical friction effects
in an Hubble time). While in most of the clusters with a bimodal BSS radial
distribution, r_avoid has been found to be located in the region of the
observed minimum, this is the second case (after NGC6388) where this
discrepancy is noted. This evidence suggests that in a few clusters the
dynamical friction seems to be somehow less efficient than expected.
  We have also used this data base to construct the radial star density profile
of the cluster: this is the most extended and accurate radial profile ever
published for this cluster, including detailed star counts in the very inner
region. The star density profile is reproduced by a standard King Model with an
extended core (~25'') and a modest value of the concentration parameter
(c=1.58). A deviation from the model is noted in the most external region of
the cluster (at r>6.5' from the center). This feature needs to be further
investigated in order to address the possible presence of a tidal tail in this
cluster.


title:
Fission barriers in neutron-proton isospin plane for heavy neutron-rich
  nuclei

abstract:
  We discuss the sensitivity of fission barrier for heavy neutron-rich nuclei
to fission paths in the two dimensional neutron-proton quadrupole plane. To
this end, we use the constrained Skyrme-Hartree-Fock + BCS method, and examine
the difference of fission barriers obtained with three constraining operators,
that is, the neutron, proton, and mass quadrupole operators. We investigate
$^{220}$U, $^{236}$U, and $^{266}$U, %from proton-rich to neutron-rich uranium
isotopes, that is relevant to r-process nucleosynthesis. We find that the
fission barrier heights are almost the same among the three constraining
operators even for neutron-rich nuclei, indicating that the usual way to
calculate fission barriers with the mass quadrupole operator is well justified.
We also discuss the difference between proton and neutron deformation
parameters along the fission paths.


title: Matching stationary spacetimes

abstract:
  Using the quasi-Maxwell formalism, we derive the necessary and sufficient
conditions for the matching of two stationary spacetimes along a stationary
timelike hypersurface, expressed in terms of the gravitational and
gravitomagnetic fields and the 2-dimensional matching surface on the space
manifold. We prove existence and uniqueness results to the matching problem for
stationary perfect fluid spacetimes with spherical, planar, hyperbolic and
cylindrical symmetry. Finally, we find an explicit interior for the cylindrical
analogue of the NUT spacetime.


title:
Effect of oxygen-doping on Bi$_{2}$Sr$_{2}$Ca$_{2}$Cu$_{3}$O$_{10 +
  \delta}$ vortex matter: Crossover from electromagnetic to Josephson
  interlayer coupling

abstract: Erroneous duplicate of arXiv:0802.2617, removed by arXiv admin


title:
Effect of oxygen-doping on Bi-2223 vortex matter: Crossover from
  electromagnetic to Josephson interlayer coupling

abstract:
  We study the effect of oxygen-doping on the critical temperature, Tc, the
vortex matter phase diagram and the nature of the coupling mechanism between
the Cu-O layers in the three-layer Bi2Sr2Ca2Cu3O10+delta (Bi-2223) compound.
Contrary to previous reports, in the overdoped (OD) regime we do find a
variation of Tc with increasing the oxygen partial-pressure of the
post-annealing treatment. This variation is less significant than in the
bi-layer parental compound Bi-2212 and does not follow the universal Tc
vs.delta relation. Magnetic measurements reveal that increasing delta enlarges
the field and temperature stability of the Bragg glass phase. These findings
imply that the interlayer coupling between Cu-O layers enhances with delta. The
anisotropy parameter estimated from directional first-penetration field
measurements monotonously decreases from 50 in the underdoped (UD) to 15 in the
OD regimes. However, the in-plane penetration depth presents a boomerang-like
behaviour with $\delta$, reaching its minimum value close to optimal doping.
These two facts lead to a crossover from a Josephson(OD) to
electromagnetic(UD)-dominated coupling of adjacent Cu-O layers in the vicinity
of optimal doping.


title:
Muon Anomaly from Lepton Vacuum Polarization and The Mellin--Barnes
  Representation

abstract:
  We evaluate, analytically, a specific class of eighth--order and tenth--order
QED contributions to the anomalous magnetic moment of the muon. They are
generated by Feynman diagrams involving lowest order vacuum polarization
insertions of leptons $l=e,\mu$, and $\tau$. The results are given in the form
of analytic expansions in terms of the mass ratios $m_e/m_\mu$ and
$m_\mu/m_\tau$. We compute as many terms as required by the error induced by
the present experimental uncertainty on the lepton masses. We show how the
Mellin--Barnes integral representation of Feynman parametric integrals allows
for an easy analytic evaluation of as many terms as wanted in these expansions
and how its underlying algebraic structure generalizes the standard
renormalization group properties. We also discuss the generalization of this
technique to the case where two independent mass ratios appear. Comparison with
previous numerical and analytic evaluations made in the literature, whenever
pertinent, are also made.


title:
On the time to reach maximum for a variety of constrained Brownian
  motions

abstract:
  We derive P(M,t_m), the joint probability density of the maximum M and the
time t_m at which this maximum is achieved for a class of constrained Brownian
motions. In particular, we provide explicit results for excursions, meanders
and reflected bridges associated with Brownian motion. By subsequently
integrating over M, the marginal density P(t_m) is obtained in each case in the
form of a doubly infinite series. For the excursion and meander, we analyse the
moments and asymptotic limits of P(t_m) in some detail and show that the
theoretical results are in excellent accord with numerical simulations. Our
primary method of derivation is based on a path integral technique; however, an
alternative approach is also outlined which is founded on certain "agreement
formulae" that are encountered more generally in probabilistic studies of
Brownian motion processes.


title: Dynamics of icosahedral viruses: what does Viral Tiling Theory teach us?

abstract:
  We present a top-down approach to the study of the dynamics of icosahedral
virus capsids, in which each protein is approximated by a point mass. Although
this represents a rather crude coarse-graining, we argue that it highlights
several generic features of vibrational spectra which have been overlooked so
far. We furthermore discuss the consequences of approximate inversion symmetry
as well as the role played by Viral Tiling Theory in the study of virus capsid
vibrations.


title: Search for 4th family quarks with the ATLAS detector

abstract:
  The pair production of heavy fourth-generation quarks, which are predicted
under the hypothesis of flavor democracy, is studied using tree-level Monte
Carlo generators and fast detector simulation. Two heavy-quark mass values, 500
and 750$\gev$, are considered with the assumption that the fourth family mixes
primarily with the two light families. It is shown that a clear signature will
be observed in the data collected by the ATLAS detector, after the first year
of low-luminosity running at the Large Hadron Collider.


title:
Scalar FCNC and rare top decays in a two Higgs doublet model "for the
  top"

abstract:
  In the so called two Higgs doublet model for the top-quark (T2HDM), first
suggested by Das and Kao, the top quark receives a special status, which endows
it with a naturally large mass, and also potentially gives rise to large flavor
changing neutral currents (FCNC) only in the up-quark sector. In this paper we
calculate the branching ratio (BR) for the rare decays t->ch and h->tc (h is a
neutral Higgs) in the T2HDM, at tree level and at 1-loop when it exceeds the
tree-level. We compare our results to predictions from other versions of 2HDM's
and find that the scalar FCNC in the T2HDM can play a significant role in these
decays. In particular, the 1-loop mediated decays can be significantly enhanced
in the T2HDM compared to the 2HDM of types I and II, in some instances reaching
BR~10^-4 which is within the detectable level at the LHC.


title: Self-passivating edge reconstructions of graphene

abstract:
  Planar reconstruction patterns at the zigzag and armchair edges of graphene
were investigated with density functional theory. It was unexpectedly found
that the zigzag edge is metastable and a planar reconstruction spontaneously
takes place at room temperature. The reconstruction changes electronic
structure and self-passivates the edge with respect to adsorption of atomic
hydrogen from molecular atmosphere.


title: Clustering of Emission-line Stars in the W5E HII region

abstract:
  We have made a new survey of emission-line stars in the W5E HII region to
investigate the population of PMS stars near the OB stars by using the Wide
Field Grism Spectrograph 2 (WFGS2). A total of 139 H-alpha emission stars were
detected and their g'i'-photometry was performed. The spatial distribution of
them shows three aggregates, i.e., two aggregates near the bright-rimmed clouds
at the edge of W5E HII region (BRC 13 and BRC 14) and one near the exciting O7V
star. The age and mass of each H-alpha star were estimated from the extinction
corrected color-magnitude diagram and theoretical evolutionary tracks. We
found, for the first time in this region, that the young stars near the
exciting star are systematically older (4 Myr) than those near the edge of the
HII region (1 Myr). This result supports that the formation of stars proceed
sequentially from the center of HII region to the eastern bright rim. We
further suggest a possibility that the birth of low mass stars near the
exciting star of HII region precede the production of massive OB stars in the
pre-existing molecular cloud.


title:
A note on the computation of Puiseux series solutions of the Riccatti
  equation associated with a homogeneous linear ordinary differential equation

abstract:
  We present in this paper a detailed note on the computation of Puiseux series
solutions of the Riccatti equation associated with a homogeneous linear
ordinary differential equation. This paper is a continuation of [1] which was
on the complexity of solving arbitrary ordinary polynomial differential
equations in terms of Puiseux series.


title:
Second order quasilinear PDEs and conformal structures in projective
  space

abstract:
  We investigate second order quasilinear equations of the form f_{ij}
u_{x_ix_j}=0 where u is a function of n independent variables x_1, ..., x_n,
and the coefficients f_{ij} are functions of the first order derivatives
p^1=u_{x_1}, >..., p^n=u_{x_n} only. We demonstrate that the natural
equivalence group of the problem is isomorphic to SL(n+1, R), which acts by
projective transformations on the space P^n with coordinates p^1, ..., p^n. The
coefficient matrix f_{ij} defines on P^n a conformal structure f_{ij} dp^idp^j.
In this paper we concentrate on the case n=3, although some results hold in any
dimension. The necessary and sufficient conditions for the integrability of
such equations by the method of hydrodynamic reductions are derived. These
conditions constitute a complicated over-determined system of PDEs for the
coefficients f_{ij}, which is in involution. We prove that the moduli space of
integrable equations is 20-dimensional. Based on these results, we show that
any equation satisfying the integrability conditions is necessarily
conservative, and possesses a dispersionless Lax pair. Reformulated in
differential-geometric terms, the integrability conditions imply that the
conformal structure f_{ij} dp^idp^j is conformally flat, and possesses an
infinity of 3-conjugate null coordinate systems. Integrable equations provide
an abundance of explicit examples of such conformal structures parametrized by
elementary functions, elliptic functions and modular forms.


title:
Anderson localization on Falicov-Kimball model with
  next-nearest-neighbor hopping and long-range correlated disorder

abstract:
  The phase diagram of correlated, disordered electron systems is calculated
within dynamical mean-field theory for the Anderson-Falicov-Kimball model with
nearest-neighbors and next-nearest-neighbors hopping. The half-filled band is
analyzed in terms of the chemical potential of the system using the geometric
and arithmetic averages. We also introduce the on-site energies exhibiting a
long-range correlated disorder, which generates a system with similar
characteristics as the one created by a random independent variable
distribution. A decrease in the correlated disorder reduces the extended phase.


title: Electronic spin drift in graphene field effect transistors

abstract:
  We studied the drift of electron spins under an applied DC electric field in
single layer graphene spin valves in a field effect transport geometry at room
temperature. In the metallic conduction regime ($n \simeq 3.5 \times 10^{16}$
m$^{-2}$), for DC fields of about $\pm$70 kV/m applied between the spin
injector and spin detector, the spin valve signals are increased/decreased,
depending on the direction of the DC field and the carrier type, by as much as
$\pm$50%. Sign reversal of the drift effect is observed when switching from
hole to electron conduction. In the vicinity of the Dirac neutrality point the
drift effect is strongly suppressed. The experiments are in quantitative
agreement with a drift-diffusion model of spin transport.


title: Strange nonchaotic attractors in driven delay--dynamics

abstract:
  Strange nonchaotic attractors (SNAs) are observed in quasiperiodically driven
time--delay systems. Since the largest Lyapunov exponent is nonpositive,
trajectories in two such identical but distinct systems show the property of
{\it phase}--synchronization. Our results are illustrated in the model SQUID
and R\"ossler oscillator systems.


title: Inflation-Produced Magnetic Fields in R^n F^2 and I F^2 models

abstract:
  We re-analyze the production of seed magnetic fields during Inflation in
(R/m^2)^n F_{\mu \nu}F^{\mu \nu} and I F_{\mu \nu}F^{\mu \nu} models, where n
is a positive integer, R the Ricci scalar, m a mass parameter, and I \propto
\eta^\alpha a power-law function of the conformal time \eta, with \alpha a
positive real number. If m is the electron mass, the produced fields are
uninterestingly small for all n. Taking m as a free parameter we find that, for
n \geq 2, the produced magnetic fields can be sufficiently strong in order to
seed dynamo mechanism and then to explain galactic magnetism. For \alpha
\gtrsim 2, there is always a window in the parameters defining Inflation such
that the generated magnetic fields are astrophysically interesting. Moreover,
if Inflation is (almost) de Sitter and the produced fields almost
scale-invariant (\alpha \simeq 4), their intensity can be strong enough to
directly explain the presence of microgauss galactic magnetic fields.


title:
The Paschen-Back effect in the Li I 6708 A line and the presence of
  lithium in cool magnetic Ap stars

abstract:
  A number of cool magnetic Ap stars show a prominent feature at lambda 6708 A.
Its identification with Li I remains controversial due to a poor knowledge of
the spectra of rare-earth elements that are strongly enhanced in peculiar stars
and can potentially provide an alternative identification. We suggest to
investigate the 6708 line in Ap stars with strong magnetic fields. In these
objects the magnetic broadening and splitting provides an additional powerful
criterium for line identification, allowing to use the whole line profile
instead of a mere coincidence of the observed and predicted wavelength. Due to
a small separation of the Li I doublet components, their magnetic splitting
pattern deviates from the one expected for the Zeeman effect even in relatively
weak fields. We carry out detailed calculations of the transition between the
Zeeman and Paschen-Back regimes in the magnetic splitting of the Li I line and
compute polarized synthetic spectra for the range of field strength expected in
Ap stars. Theoretical spectral synthesis is compared with the high-resolution
observations of cool Ap stars HD 116114, HD 166473 and HD 154708, which have a
mean field strength of 6.4, 8.6 and 24.5 kG, respectively, and show a strong
6708 A line. High-resolution spectra for the 6708 A region are analysed for 17
magnetic Ap stars. The presence of the 6708 A line is confirmed in 9 stars and
reported for the first time in 6 stars. We demonstrate that the observed
profiles of the 6708 A line in the strong field stars HD 116114, HD 166473 and
HD 154708 correspond rather well to the theoretical calculations assuming the
Li I identification. Inclusion of the Paschen-Back effect improves the
agreement with observations, especially for HD 154708. Results of our study
confirm the Li I identification proposed for the 6708 A line in cool Ap stars.


title:
Canonical Weierstrass Representation of Minimal and Maximal Surfaces in
  the Three-dimensional Minkowski Space

abstract:
  We prove that any minimal (maximal) strongly regular surface in the
three-dimensional Minkowski space locally admits canonical principal
parameters. Using this result, we find a canonical representation of minimal
strongly regular time-like surfaces, which makes more precise the Weierstrass
representation and shows more precisely the correspondence between these
surfaces and holomorphic functions (in the Gauss plane). We also find a
canonical representation of maximal strongly regular space-like surfaces, which
makes more precise the Weierstrass representation and shows more precisely the
correspondence between these surfaces and holomorphic functions (in the Lorentz
plane). This allows us to describe locally the solutions of the corresponding
natural partial differential equations.


title: Gold nanoparticle-pentacene memory-transistors

abstract:
  We demonstrate an organic memory-transistor device based on a pentacene-gold
nanoparticles active layer. Gold (Au) nanoparticles are immobilized on the gate
dielectric (silicon dioxide) of a pentacene transistor by an amino-terminated
self-assembled monolayer. Under the application of writing and erasing pulses
on the gate, large threshold voltage shift (22 V) and on/off drain current
ratio of ~3E4 are obtained. The hole field-effect mobility of the transistor is
similar in the on and off states (less than a factor 2). Charge retention times
up to 4500 s are observed. The memory effect is mainly attributed to the Au
nanoparticles.


title:
On Parametrization of the Linear GL(4,C) and Unitary SU(4) Groups in
  Terms of Dirac Matrices

abstract:
  Parametrization of $4\times 4$-matrices $G$ of the complex linear group
$GL(4,C)$ in terms of four complex 4-vector parameters $(k,m,n,l)$ is
investigated. Additional restrictions separating some subgroups of $GL(4,C)$
are given explicitly. In the given parametrization, the problem of inverting
any $4\times 4$ matrix $G$ is solved. Expression for determinant of any matrix
$G$ is found: $\det G = F(k,m,n,l)$. Unitarity conditions $G^{+} = G^{-1}$ have
been formulated in the form of non-linear cubic algebraic equations including
complex conjugation. Several simplest solutions of these unitarity equations
have been found: three 2-parametric subgroups $G_{1}$, $G_{2}$, $G_{3}$ - each
of subgroups consists of two commuting Abelian unitary groups; 4-parametric
unitary subgroup consisting of a product of a 3-parametric group isomorphic
SU(2) and 1-parametric Abelian group. The Dirac basis of generators
$\Lambda_{k}$, being of Gell-Mann type, substantially differs from the basis
$\lambda_{i}$ used in the literature on SU(4) group, formulas relating them are
found - they permit to separate SU(3) subgroup in SU(4). Special way to list 15
Dirac generators of $GL(4,C)$ can be used $\{\Lambda_k\} =
\{\alpha_i\oplus\beta_j\oplus(\alpha_iV\beta_j = {\boldsymbol K} \oplus
{\boldsymbol L}\oplus{\boldsymbol M})\}$, which permit to factorize SU(4)
transformations according to $S = e^{i\vec{a}\vec{\alpha}}
e^{i\vec{b}\vec\beta}} e^{i{\boldsymbol k}{\boldsymbol K}} e^{i{\boldsymbol
l}{\boldsymbol L}} e^{i\boldsymbol m}{\boldsymbol M}}$, where two first factors
commute with each other and are isomorphic to SU(2) group, the three last ones
are 3-parametric groups, each of them consisting of three Abelian commuting
unitary subgroups.


title:
Advanced resistivity model for arbitrary magnetization orientation
  applied to a series of compressive- to tensile-strained (Ga,Mn)As layers

abstract:
  The longitudinal and transverse resistivities of differently strained
(Ga,Mn)As layers are theoretically and experimentally studied as a function of
the magnetization orientation. The strain in the series of (Ga,Mn)As layers is
gradually varied from compressive to tensile using (In,Ga)As templates with
different In concentrations. Analytical expressions for the resistivities are
derived from a series expansion of the resistivity tensor with respect to the
direction cosines of the magnetization. In order to quantitatively model the
experimental data, terms up to the fourth order have to be included. The
expressions derived are generally valid for any single-crystalline cubic and
tetragonal ferromagnet and apply to arbitrary surface orientations and current
directions. The model phenomenologically incorporates the longitudinal and
transverse anisotropic magnetoresistance as well as the anomalous Hall effect.
The resistivity parameters obtained from a comparison between experiment and
theory are found to systematically vary with the strain in the layer.


title:
A limited in bandwidth uniformity for the functional limit law of the
  increments of the empirical process

abstract:
  Consider the following local empirical process indexed by $K\in \mathcal{G}$,
for fixed $h>0$ and $z\in \mathbb{R}^d$: $$G_n(K,h,z):=\sum_{i=1}^n K
\Bigl(\frac{Z_i-z}{h^{1/d}}\Big) - \mathbbE \Bigl(K
\Bigl(\frac{Z_i-z}{h^{1/d}}\Big)\Big),$$ where the $Z_i$ are i.i.d. on
$\mathbb{R}^d$. We provide an extension of a result of Mason (2004). Namely,
under mild conditions on $\mathcal{G}$ and on the law of $Z_1$, we establish a
uniform functional limit law for the collections of processes
$\bigl\{G_n(\cdot,h_n,z), z\in H, h\in [h_n,\mathfrak{h}_n]\big\}$, where
$H\subset \mathbb{R}^d$ is a compact set with nonempty interior and where $h_n$
and $\mathfrak{h}_n$ satisfy the Cs\"{o}rg\H{o}-R\'{e}v\'{e}sz-Stute
conditions.


title: Topological Black Holes in Lovelock-Born-Infeld Gravity

abstract:
  In this paper, we present topological black holes of third order Lovelock
gravity in the presence of cosmological constant and nonlinear electromagnetic
Born-Infeld field. Depending on the metric parameters, these solutions may be
interpreted as black hole solutions with inner and outer event horizons, an
extreme black hole or naked singularity. We investigate the thermodynamics of
asymptotically flat solutions and show that the thermodynamic and conserved
quantities of these black holes satisfy the first law of thermodynamic. We also
endow the Ricci flat solutions with a global rotation and calculate the finite
action and conserved quantities of these class of solutions by using the
counterterm method. We compute the entropy through the use of the Gibbs-Duhem
relation and find that the entropy obeys the area law. We obtain a Smarr-type
formula for the mass as a function of the entropy, the angular momenta, and the
charge, and compute temperature, angular velocities, and electric potential and
show that these thermodynamic quantities coincide with their values which are
computed through the use of geometry. Finally, we perform a stability analysis
for this class of solutions in both the canonical and the grand-canonical
ensemble and show that the presence of a nonlinear electromagnetic field and
higher curvature terms has no effect on the stability of the black branes, and
they are stable in the whole phase space.


title: Hidden Symmetries of M-Theory and Its Dynamical Realization

abstract:
  We discuss hidden symmetries of M-theory, its feedback on the construction of
the M-theory effective action, and a response of the effective action when
locality is preserved. In particular, the locality of special symmetries of the
duality-symmetric linearized gravity constraints the index structure of the
dual to graviton field in the same manner as it is required to separate the
levels 0 and 1 generators subalgebra from the infinite-dimensional hidden
symmetry algebra of gravitational theory. This conclusion fails once matter
fields are taken into account and we give arguments for that. We end up
outlining current problems and development perspectives.


title:
A new Comptonization model for low-magnetized accreting neutron stars in
  low mass X-ray binaries

abstract:
  We developed a new model for the X-ray spectral fitting \xspec package which
takes into account the effects of both thermal and dynamical (i.e. bulk)
Comptonization. The model consists of two components: one is the direct
blackbody-like emission due to seed photons which are not subjected to
effective Compton scattering, while the other one is a convolution of the
Green's function of the energy operator with a blackbody-like seed photon
spectrum. When combined thermal and bulk effects are considered, the analytic
form of the Green's function may be obtained as a solution of the diffusion
Comptonization equation. Using data from the BeppoSAX, INTEGRAL and RXTE
satellites, we test our model on the spectra of a sample of six persistently
low magnetic field bright neutron star Low Mass X-ray Binaries, covering three
different spectral states. Particular attention is given to the transient
powerlaw-like hard X-ray (> 30 keV) tails that we interpret in the framework of
the bulk motion Comptonization process. We show that the values of the best-fit
delta-parameter, which represents the importance of bulk with respect to
thermal Comptonization, can be physically meaningful and can at least
qualitatively describe the physical conditions of the environment in the
innermost part of the system. Moreover, we show that in fitting the thermal
Comptonization spectra to the X-ray spectra of these systems, the best-fit
parameters of our model are in excellent agreement with those of COMPTT, a
broadly used and well established XSPEC model.


title: Universal Properties of Ferroelectric Domains

abstract:
  Basing on Ginzburg-Landau approach we generalize the Kittel theory and derive
the interpolation formula for the temperature evolution of a multi-domain
polarization profile P(x,z). We resolve the long-standing problem of the
near-surface polarization behavior in ferroelectric domains and demonstrate the
polarization vanishing instead of usually assumed fractal domain branching. We
propose an effective scaling approach to compare the properties of different
domain-containing ferroelectric plates and films.


title:
Separation and coupling cutoffs for tuples of independent Markov
  processes

abstract:
  We consider an $n$-tuple of independent ergodic Markov processes, each of
which converges (in the sense of separation distance) at an exponential rate,
and obtain a necessary and sufficient condition for the $n$-tuple to exhibit a
separation cutoff. We also provide general bounds on the (asymmetric) window
size of the cutoff, and indicate links to classical extreme value theory.


title:
Signal of New Physics and Chemical Composition of Matter in Core
  Crossing Neutrinos

abstract:
  We consider non-standard matter effect in flavor conversion of neutrinos
crossing the core of the Earth. We show that oscillation of core crossing
neutrinos with $E \gsim 0.5$ GeV can be well described by a first order
perturbation theory. We show that due to non-standard matter effect varying
chemical composition in the Earth can modify the neutrino flavor conversion by
100%. Effects of CP violating phases in non-standard Neutral Current
interactions are emphasized in particular.


title: The normal distribution in some constrained sample spaces

abstract:
  Phenomena with a constrained sample space appear frequently in practice. This
is the case e.g. with strictly positive data and with compositional data, like
percentages and the like. If the natural measure of difference is not the
absolute one, it is possible to use simple algebraic properties to show that it
is more convenient to work with a geometry that is not the usual Euclidean
geometry in real space, and with a measure which is not the usual Lebesgue
measure, leading to alternative models which better fit the phenomenon under
study. The general approach is presented and illustrated both on the positive
real line and on the D-part simplex.


title: Percolation transition in correlated static model

abstract:
  We introduce a correlated static model and investigate a percolation
transition. The model is a modification of the static model and is
characterized by assortative degree-degree correlation. As one varies the edge
density, the network undergoes a percolation transition. The percolation
transition is characterized by a weak singular behavior of the mean cluster
size and power-law scalings of the percolation order parameter and the cluster
size distribution in the entire non-percolating phase. These results suggest
that the assortative degree-degree correlation generates a global structural
correlation which is relevant to the percolation critical phenomena of complex
networks.


title:
Complete moment and integral convergence for sums of negatively
  associated random variables

abstract:
  For a sequence of identically distributed negatively associated random
variables $\{X_n; n\geq 1\}$ with partial sums $S_n=\sum_{i=1}^nX_i, n\geq 1$,
refinements are presented of the classical Baum-Katz and Lai complete
convergence theorems. More specifically, necessary and sufficient moment
conditions are provided for complete moment convergence of the form $$ \sum_{n
\ge n_0} n^{r -2 -\frac{1}{pq}} a_n E(\max_{1 \le k \le n}|S_k|^{\frac{1}{q}} -
\epsilon b_n^{\frac{1}{pq}})^+ < \infty $$ to hold where $r>1, q>0$ and either
$n_0=1, 0<p<2, a_n=1, b_n=n$ or $n_0=3, p=2, a_n=(\log n)^{-\frac{1}{2q}},
b_n=n\log n$. These results extend results of Chow (1988) and Li and
Sp\u{a}taru (2005) from the independent and identically distributed case to the
identically distributed negatively associated setting. The complete moment
convergence is also shown to be equivalent to a form of complete integral
convergence.


title:
Hyperon-nucleon single-particle potentials with low-momentum
  interactions

abstract:
  Single-particle potentials in Hartree-Fock approximation for different
hyperon-nucleon (YN) channels are calculated in the framework of the effective
low-momentum YN interaction V_lowk. In contrast to the nucleon-nucleon
interaction, the available experimental data for the YN interaction are scarce.
As a consequence no unique YN low-momentum potential V_lowk can be predicted
from the various bare potentials. The resulting momentum- and density-dependent
single-particle potentials for several different bare OBE models and for chiral
effective field theory are compared to each other.


title:
X-ray spectra from magnetar candidates. I. Monte Carlo simulations in
  the non-relativistic regime

abstract:
  The anomalous X-ray pulsars and soft gamma-repeaters are peculiar high-energy
sources believed to host a magnetar, i.e. an ultra-magnetized neutron star.
Their persistent, soft X-ray emission (~1-10 keV)is usually modeled by the
superposition of a blackbody and a power-law tail. It has been suggested that
this spectrum forms as the thermal photons emitted by the star surface traverse
the magnetosphere. Magnetar magnetospheres are likely different from those of
ordinary radio-pulsars, since the external magnetic field may acquire a
toroidal component as a consequence of the deformation of the star crust
induced by the super-strong interior field. In turn, the magnetosphere will be
permeated by currents that can boost primary photons through repeated
scatterings. Here we present 3D Monte Carlo simulations of photon propagation
in a twisted magnetosphere. Our model is based on a simplified treatment of the
charge carriers velocity distribution which, however, accounts for the particle
collective motion, in addition to the thermal one. Present treatment is
restricted to conservative (Thomson) scattering in the electron rest frame. The
code, nonetheless, is completely general and inclusion of the relativistic QED
resonant cross section, which is required in the modeling of the hard (~20-200
keV) spectral tails observed in the magnetar candidates, is under way. The
properties of emerging spectra have been assessed under different conditions,
by exploring the model parameter space, including effects arising from the
viewing geometry. Monte Carlo runs have been collected into a spectral archive.
Two tabulated XSPEC spectral models, with and without viewing angles, have been
produced and applied to the 0.1-10 keV XMM-Newton EPIC-pn spectrum of the AXP
CXOU J1647-4552.


title: Search for tetraquark candidate Z(4430) in meson photoproduction

abstract:
  We propose a search for the newly discovered tetraquark candidate Z(4430) in
photoproduction. Based on the Belle results we show that if Z(4430) is a
genuine resonance, its significantly large coupling to $\psi^\prime\pi$ will
cause it to stand out above the background in $\gamma p\to Z^+(4430) n\to
\psi^\prime \pi^+ n$. We consider the dependence of the cross section for the
quantum numbers ($J^{P}=1^{-}$, $1^{+}$ or $0^{-}$).