title: Black Holes, Qubits and Octonions

abstract:
  We review the recently established relationships between black hole entropy
in string theory and the quantum entanglement of qubits and qutrits in quantum
information theory. The first example is provided by the measure of the
tripartite entanglement of three qubits, known as the 3-tangle, and the entropy
of the 8-charge STU black hole of N=2 supergravity, both of which are given by
the [SL(2)]^3 invariant hyperdeterminant, a quantity first introduced by Cayley
in 1845. There are further relationships between the attractor mechanism and
local distillation protocols. At the microscopic level, the black holes are
described by intersecting D3-branes whose wrapping around the six compact
dimensions T^6 provides the string-theoretic interpretation of the charges and
we associate the three-qubit basis vectors, |ABC> (A,B,C=0 or 1), with the
corresponding 8 wrapping cycles. The black hole/qubit correspondence extends to
the 56 charge N=8 black holes and the tripartite entanglement of seven qubits
where the measure is provided by Cartan's E_7 supset [SL(2)]^7 invariant. The
qubits are naturally described by the seven vertices ABCDEFG of the Fano plane,
which provides the multiplication table of the seven imaginary octonions,
reflecting the fact that E_7 has a natural structure of an O-graded algebra.
This in turn provides a novel imaginary octonionic interpretation of the 56=7 x
8 charges of N=8: the 24=3 x 8 NS-NS charges correspond to the three imaginary
quaternions and the 32=4 x 8 R-R to the four complementary imaginary octonions.
N=8 black holes (or black strings) in five dimensions are also related to the
bipartite entanglement of three qutrits (3-state systems), where the analogous
measure is Cartan's E_6 supset [SL(3)]^3 invariant.


title: Neutron spectroscopic factors of Ni isotopes from transfer reactions

abstract:
  177 neutron spectroscopic factors for nickel isotopes have been extracted by
performing a systematic analysis of the angular distributions measured from
(d,p) transfer reactions. A subset of the extracted spectroscopic factors are
compared to predictions of large-basis shell models in the full pf model space
using the GXPF1A effective interaction, and the (f5/2, p3/2, p1/2, g9/2) model
space using the JJ4PNA interaction. For ground states, the predicted
spectroscopic factors using the GXPF1A effective interaction in the full pf
model space agree very well with the experimental values, while predictions
based on several other effective interactions and model spaces are about 30%
higher than the experimental values. For low-energy excited states (<3.5 MeV),
the agreement between the extracted spectroscopic factors and shell model
calculations is not better than a factor of two.


title: Two-Loop QCD Corrections to the Heavy-to-Light Quark Decay

abstract:
  We present an analytic expression for the two-loop QCD corrections to the
decay process b -> u W^*, where b and u are a massive and massless quark,
respectively, while W^* is an off-shell charged weak boson. Since the W-boson
can subsequently decay in a lepton anti-neutrino pair, the results of this
paper are a first step towards a fully analytic computation of differential
distributions for the semileptonic decay of a b-quark. The latter partonic
process plays a crucial role in the study of inclusive semileptonic charmless
decays of B-mesons. The three independent form factors characterizing the b W u
vertex are provided in form of a Laurent series in (d-4), where d is the
space-time dimension. The coefficients in the series are expressed in terms of
Harmonic Polylogarithms of maximal weight 4, and are functions of the invariant
mass of the leptonic decay products of the W-boson.


title: Jet breaks at the end of the slow decline phase of Swift GRB lightcurves

abstract:
  The Swift mission has discovered an intriguing feature of Gamma-Ray Burst
(GRBs) afterglows, a phase of shallow decline of the flux in the X-ray and
optical lightcurves. This behaviour is typically attributed to energy injection
into the burst ejecta. At some point this phase ends, resulting in a break in
the lightcurve, which is commonly interpreted as the cessation of the energy
injection. In a few cases, however, while breaks in the X-ray lightcurve are
observed, optical emission continues its slow flux decline. This behaviour
suggests a more complex scenario. In this paper, we present a model that
invokes a double component outflow, in which narrowly collimated ejecta are
responsible for the X-ray emission while a broad outflow is responsible for the
optical emission. The narrow component can produce a jet break in the X-ray
lightcurve at relatively early times, while the optical emission does not break
due to its lower degree of collimation. In our model both components are
subject to energy injection for the whole duration of the follow-up
observations. We apply this model to GRBs with chromatic breaks, and we show
how it might change the interpretation of the GRBs canonical lightcurve. We
also study our model from a theoretical point of view, investigating the
possible configurations of frequencies and the values of GRB physical
parameters allowed in our model.


title: Complexity invariance by replication in the quantum square well

abstract:
  A new kind of invariance by replication of a statistical measure of
complexity is considered. We show that the set of energy eigenstates of the
quantum infinite square well displays this particular invariance. Then, this
system presents a constant complexity for all the energy eigenstates.

categories: nlin.PS cond-mat.stat-mech physics.atom-ph quant-ph


title: Directed graphs without short cycles

abstract:
  For a directed graph $G$ without loops or parallel edges, let $\beta(G)$
denote the size of the smallest feedback arc set, i.e., the smallest subset $X
\subset E(G)$ such that $G \sm X$ has no directed cycles. Let $\gamma(G)$ be
the number of unordered pairs of vertices of $G$ which are not adjacent. We
prove that every directed graph whose shortest directed cycle has length at
least $r \ge 4$ satisfies $\beta(G) \le c\gamma(G)/r^2$, where $c$ is an
absolute constant. This is tight up to the constant factor and extends a result
of Chudnovsky, Seymour, and Sullivan.
  This result can be also used to answer a question of Yuster concerning almost
given length cycles in digraphs. We show that for any fixed $0 < \theta < 1/2$
and sufficiently large $n$, if $G$ is a digraph with $n$ vertices and $\beta(G)
\ge \theta n^2$, then for any $0 \le m \le \theta n-o(n)$ it contains a
directed cycle whose length is between $m$ and $m+6 \theta^{-1/2}$. Moreover,
there is a constant $C$ such that either $G$ contains directed cycles of every
length between $C$ and $\theta n-o(n)$ or it is close to a digraph $G'$ with a
simple structure: every strong component of $G'$ is periodic. These results are
also tight up to the constant factors.


title: A Deep XMM-Newton Observation of the Quasar 3C 287

abstract:
  We report on an XMM-Newton observation of the z=1.055 quasar and Giga-hertz
Peaked Spectrum (GPS) source 3C 287. Our 62.3 ksec observation provides an
exceptional X-ray view of a prominent member of this important subclass of
active galactic nuclei (AGN). The X-ray spectra of 3C 287 are consistent with a
simple absorbed power-law with a spectral index of Gamma = 1.72 +/- 0.02. Our
fits imply a bolometric luminosity of L = 5.8 +/- 0.2 E+45 erg/s over the
0.3-10.0 keV band; this gives a mass lower limit of M > 4.6 E+7 Msun, assuming
X-rays contribute 10% of the bolometric luminosity and radiation at the
Eddington limit. Iron emission lines are common in the X-ray spectra of many
AGN, but the observed spectra appear to rule out strong emission lines in 3C
287. The simple power-law spectrum and absence of strong emission lines may
support a picture where our line of sight intersects a relativistic jet.
Milliarcsecond radio imaging of 3C 287 appears to support this interpretation.
We discuss our results in the context of different AGN sub-classes and the
possibility that GPS sources harbor newly-formed black hole jets.


title:
Exchange Interactions and Principle of Minimal Energy in Relativistic
  Schroedinger Theory

abstract:
  The principle of minimal energy, which has been set up in the preceding
papers for systems of non-identical particles (e.g. positronium), is now
generalized to include also identical particles. Since the latter kind of
particles feels also the exchange forces (besides the usual electromagnetic
forces), one has to deal with non-zero exchange potentials which render the
theory nonlinear, according to the non-Abelian character of Relativistic
Schroedinger Theory (RST). However, the present extension of the variational
principle refers only to the linearized version of RST in order to keep the
calculations sufficiently simple. It is also demonstrated that in RST the Dirac
particles can occur in fermionic and bosonic quantum states; and the
mathematical and physical consistency of the variational principle is validated
for both types of states (concretely the fermionic hydrogen state 2p_3/2 and
the bosonic positronium state 2^1P_1).


title:
Almost all one-relator groups with at least three generators are
  residually finite

abstract:
  We prove that with probability tending to 1, a 1-relator group with at least
3 generators and relator of length n is residually finite, virtually residually
(finite p)-group for all sufficiently large p, and coherent. The proof uses
both combinatorial group theory and non-trivial results about Brownian motions,
bridges and excursions in R^k.


title: Tropical Convex Hull Computations

abstract:
  This is a survey on tropical polytopes from the combinatorial point of view
and with a focus on algorithms. Tropical convexity is interesting because it
relates a number of combinatorial concepts including ordinary convexity,
monomial ideals, subdivisions of products of simplices, matroid theory, finite
metric spaces, and the tropical Grassmannians. The relationship between these
topics is explained via one running example throughout the whole paper. The
final section explains how the new version 2.9.4 of the software system
polymake can be used to compute with tropical polytopes.


title: Brauer pairs of Camina p-groups of nilpotence class 2

abstract:
  In this paper, we find a condition that characterizes when two Camina
$p$-groups of nilpotence class 2 form a Brauer pair.


title:
A new algorithm for the recursion of multisums with improved universal
  denominator

abstract:
  The purpose of the paper is to introduce two new algorithms. The first one
computes a linear recursion for proper hypergeometric multisums, by treating
one summation variable at a time, and provides rational certificates along the
way. A key part in the search of a linear recursion is an improved universal
denominator algorithm that constructs all rational solutions $x(n)$ of the
equation $$ \frac{a_m(n)}{b_m(n)}x(n+m)+...+\frac{a_0(n)}{b_0(n)}x(n)= c(n),$$
where $a_i(n), b_i(n), c(n)$ are polynomials. Our algorithm improves Abramov's
universal denominator.


title: Perturbed Floer Homology of some fibered three manifolds

abstract:
  In this paper, we write down a special Heegaard diagram for a given product
three manifold $\Sigma_g\times S^1$. We use the diagram to compute its
perturbed Heegaard Floer homology.


title:
Central limit theorem for linear eigenvalue statistics of random
  matrices with independent entries

abstract:
  We consider $n\times n$ real symmetric and Hermitian Wigner random matrices
$n^{-1/2}W$ with independent (modulo symmetry condition) entries and the (null)
sample covariance matrices $n^{-1}X^*X$ with independent entries of $m\times n$
matrix $X$. Assuming first that the 4th cumulant (excess) $\kappa_4$ of entries
of $W$ and $X$ is zero and that their 4th moments satisfy a Lindeberg type
condition, we prove that linear statistics of eigenvalues of the above matrices
satisfy the central limit theorem (CLT) as $n\to\infty$, $m\to\infty$, $m/n\to
c\in[0,\infty)$ with the same variance as for Gaussian matrices if the test
functions of statistics are smooth enough (essentially of the class
$\mathbf{C}^5$). This is done by using a simple ``interpolation trick'' from
the known results for the Gaussian matrices and the integration by parts,
presented in the form of certain differentiation formulas. Then, by using a
more elaborated version of the techniques, we prove the CLT in the case of
nonzero excess of entries again for essentially $\mathbb{C}^5$ test function.
Here the variance of statistics contains an additional term proportional to
$\kappa_4$. The proofs of all limit theorems follow essentially the same
scheme.


title: Deformation of Sasakian metrics

abstract:
  Deformations of the Reeb flow of a Sasakian manifold as transversely K\"ahler
flows may not admit compatible Sasakian metrics anymore. We show that the
triviality of the (0,2)-component of the basic Euler class characterizes the
existence of compatible Sasakian metrics for given small deformations of the
Reeb flow as transversely holomorphic Riemannian flows. We also prove a
Kodaira-Akizuki-Nakano type vanishing theorem for basic Dolbeault cohomology of
homologically orientable transversely K\"ahler foliations. As a consequence of
these results, we show that any small deformations of the Reeb flow of a
positive Sasakian manifold admit compatible Sasakian metrics.


title:
Limits on new long range nuclear spin-dependent forces set with a K-3He
  co-magnetometer

abstract:
  A magnetometer using spin-polarized K and $^3$He atoms occupying the same
volume is used to search for anomalous nuclear spin-dependent forces generated
by a separate $^3$He spin source. We measure changes in the $^3$He spin
precession frequency with a resolution of 18 pHz and constrain anomalous spin
forces between neutrons to be less than $2 \times 10^{-8}$ of their magnetic or
less than $2\times 10^{-3}$ of their gravitational interactions on a length
scale of 50 cm. We present new limits on neutron coupling to light pseudoscalar
and vector particles, including torsion, and constraints on recently proposed
models involving unparticles and spontaneous breaking of Lorentz symmetry.


title: Aspects of the Holographic Study of Flavor Dynamics

abstract:
  This thesis is dedicated to the holographic study of flavor dynamics. The
technique employed is a D7-brane probing of various D3-brane backgrounds. The
first topic covered studies the influence of an external magnetic field on a
flavored large N Yang-Mills theory. The theory exhibits spontaneous chiral
symmetry breaking. The meson spectrum exhibits Zeeman splitting and
characteristic GMOR relation. The second topic examines thermal properties of
the dual gauge theory. The third topic studies the phase structure of the
finite temperature dual gauge theory in the presence of magnetic field. A phase
diagram of the theory is obtained and the meson spectrum is explored. The
fourth topic studies the addition of an external electric field. The observed
effect is dissociation of the bound quarks, favoring the meson melting, the
dissociation of mesons corresponds to an insulator/conductor phase transition.
The fifth topic studies the addition of an R-charge chemical potential via
brane probing of the spinning D3-brane geometry. The corresponding phase
diagram is obtained. The chemical potential favors the dissociation of mesons.
The last topic explores universal properties of gauge theories dual to the
Dp/Dq system. A universal discrete self-similar behavior associated to the
insulator/conductor phase transition is observed and the corresponding scaling
exponents are computed.


title: High pressure study on LaFeAsO with different Tc

abstract:
  We report studies on pressure dependence of superconducting transition
temperature (Tc) of LaFeAsO, LaFeAs(O0.5F0.5) and LaFeAs(O0.89F0.11) samples.
In-situ resistance measurements under high pressure showed that the Tc of these
three compounds increases with pressure initially, reaches a maximum value and
then decreases with further increasing pressure, although the Tc at ambient
pressure are different. The onset Tc of LaFeAsO is ~50 K at 1.5 GPa, which is
the highest record in La-based oxypnicited system. The significant change in Tc
induced by pressure is attributed to the orbital degeneracy and the electron
density of state at the Fermi level.


title:
The Impact of Neutrino Magnetic Moments on the Evolution of Massive
  Stars

abstract:
  We explore the sensitivity of massive stars to neutrino magnetic moments. We
find that the additional cooling due to the neutrino magnetic moments bring
about qualitative changes to the structure and evolution of stars in the mass
window 7 Msun < M < 18 Msun, rather than simply changing the time scales for
the burning. We describe some of the consequences of this modified evolution:
the shifts in the threshold masses for creating core-collapse supernovae and
oxygen-neon-magnesium white dwarfs and the appearance of a new type of
supernova in which a partial carbon-oxygen core explodes within a massive star.
The resulting sensitivity to the magnetic moment is at the level of (2-4) *
10^{-11} \mu_B.


title: CMB Lensing and the WMAP Cold Spot

abstract:
  Cosmologists have suggested a number of intriguing hypotheses for the origin
of the "WMAP cold spot", the coldest extended region seen in the CMB sky,
including a very large void and a collapsing texture. Either hypothesis
predicts a distinctive CMB lensing signal. We show that the upcoming generation
of high resolution CMB experiments such as ACT and SPT should be able to detect
the signatures of either textures or large voids. If either signal is detected,
it would have profound implications for cosmology.


title:
Rigidity of the \'Alvarez classes of Riemannian foliations with
  nilpotent structure Lie algebras

abstract:
  We show that if the structure algebra of a Riemannian foliation F on a closed
manifold M is nilpotent, then the integral of the \'Alvarez class of (M,F)
along every closed path is the exponential of an algebraic number. By this
result and the continuity of the \'Alvarez class under deformations shown in
arXiv:1009.1098v2, we prove that the \'Alvarez class and the geometrically
tautness of Riemannian foliations on a closed manifold M are invariant under
deformation, if the fundamental group of M has polynomial growth.


title:
Understanding the nature of electronic effective mass in double-doped
  SrTiO$_{3}$

abstract:
  We present an approach to tune the effective mass in an oxide semiconductor
by a double doping mechanism. We demonstrate this in a model oxide system
Sr$_{1-x}$La$_x$TiO$_{3-\delta}$, where we can tune the effective mass ranging
from 6--20$\mathrm{m_e}$ as a function of filling or carrier concentration and
the scattering mechanism, which are dependent on the chosen lanthanum and
oxygen vacancy concentrations. The effective mass values were calculated from
the Boltzmann transport equation using the measured transport properties of
thin films of Sr$_{1-x}$La$_x$TiO$_{3-\delta}$. Our method, which shows that
the effective mass decreases with carrier concentration, provides a means for
understanding the nature of transport processes in oxides, which typically have
large effective mass and low electron mobility, contrary to the tradional high
mobility semiconductors.


title: Dynamic Computation of Network Statistics via Updating Schema

abstract:
  In this paper we derive an updating scheme for calculating some important
network statistics such as degree, clustering coefficient, etc., aiming at
reduce the amount of computation needed to track the evolving behavior of large
networks; and more importantly, to provide efficient methods for potential use
of modeling the evolution of networks. Using the updating scheme, the network
statistics can be computed and updated easily and much faster than
re-calculating each time for large evolving networks. The update formula can
also be used to determine which edge/node will lead to the extremal change of
network statistics, providing a way of predicting or designing evolution rule
of networks.


title:
Solution of the inverse problem in spherical gravitational wave
  detectors using a model with independent bars

abstract:
  The direct detection of gravitational waves will provide valuable
astrophysical information about many celestial objects. The SCHENBERG has
already undergone its first test run. It is expected to have its first
scientific run soon. In this work a new data analysis approach is presented,
called method of independent bars, which can be used with SCHENBERG's data . We
test this method through the simulation of the detection of gravitational
waves. With this method we find the source's direction without the need to have
all six transducers operational. Also we show that the method is a
generalization of another one, already described in the literature, known as
the mode channels method.


title:
Calculation of electron-positron production in supercritical
  uranium-uranium collisions near the Coulomb barrier

abstract:
  The time-dependent Dirac equation was solved for zero-impact-parameter bare
U-U collisions in the monopole approximation using a mapped Fourier grid matrix
representation. A total of 2048 states including bound, as well as positive-
and negative-energy states for an N=1024 spatial grid were propagated to
generate occupation amplitudes as a function of internuclear separation. From
these amplitudes spectra were calculated for total inclusive positron and
electron production, and also the correlated spectra for ($e^+,e^-$) pair
production. These were analyzed as a function of nuclear sticking time in order
to establish signatures of spontaneous pair creation, i.e., QED vacuum decay.
Subcritical Fr-Fr and highly supercritical Db-Db collisions both at the Coulomb
barrier were also studied and contrasted with the U-U results.


title: Generalized Transformation for Decorated Spin Models

abstract:
  The paper discusses the transformation of decorated Ising models into an
effective \textit{undecorated} spin models, using the most general Hamiltonian
for interacting Ising models including a long range and high order
interactions. The inverse of a Vandermonde matrix with equidistant nodes
$[-s,s]$ is used to obtain an analytical expression of the transformation. This
kind of transformation is very useful to obtain the partition function of
decorated systems. The method presented by Fisher is also extended, in order to
obtain the correlation functions of the decorated Ising models transforming
into an effective undecorated Ising models. We apply this transformation to a
particular mixed spin-(1/2,1) and (1/2,2) square lattice with only nearest site
interaction. This model could be transformed into an effective uniform spin-$S$
square lattice with nearest and next-nearest interaction, furthermore the
effective Hamiltonian also include combinations of three-body and four-body
interactions, particularly we considered spin 1 and 2.


title: Low-cost fermions in classical field simulations

abstract:
  We discuss the possible extension of the bosonic classical field theory
simulations to include fermions. This problem has been addressed in terms of
the inhomogeneous mean field approximation by Aarts and Smit. By performing a
stochastic integration of an equivalent set of equations we can extend the
original 1+1 dimensional calculations so that they become feasible in higher
dimensions. We test the scheme in 2 + 1 dimensions and discuss some classical
applications with fermions for the first time, such as the decay of oscillons.


title: A Personal Account of Some PHOBOS Physics

abstract:
  This paper discusses some aspects of PHOBOS physics and its origins, in
particular participant scaling and extended longitudinal scaling, seen in A+A
and h+A collisions at all energies.


title: Indefinite extrinsic symmetric spaces I

abstract:
  We find a one-to-one correspondence between full extrinsic symmetric spaces
in (possibly degenerate) inner product spaces and certain algebraic objects
called (weak) extrinsic symmetric triples. In particular, this yields a
description of arbitrary extrinsic symmetric spaces in pseudo-Euclidean spaces
by corresponding infinitesimal objects.


title: Massive Particles from Massless Spinors

abstract:
  Spinors are lightlike. How do they combine to make massive particles? We
visit the zoo of Lagrangian singularities, or caustics, in spacetime
projections from spin space- the phase space of lightlike, 8- spinor flows. We
find that the species living there are the elementary particles. Codimension
J=(1,2,3,4) phase singularities - vortex lines, sheets, tubes, and knots, are
classified by the Coxeter groups generated by multiplicity s reflections: "mass
scatterings" off the vacuum spinors, that keep chiral pairs of matter envelopes
confined to a timelike world tube, endowing a bispinor particle with mass.
Using the volume in spin space as the action, the particle masses emerge in
terms of the multiplicities, s: the number of null zigzags needed to close a
cycle of mass scatterings. These mass values (calculated to lowest order in the
vacuum intensity) are within a few percent of the observed masses for the
leptons (J=1) and hadrons (J=3) ; but are up to 25 percent off for the mesons
(J=2).


title:
On the destruction of the hidden order in URu$_2$Si$_2$ by a strong
  magnetic field

abstract:
  We present a study of transport properties of the heavy fermion URu$_2$Si$_2$
in pulsed magnetic field. The large Nernst response of the hidden order state
is found to be suppressed when the magnetic field exceeds 35 T. The combination
of resistivity, Hall and Nernst data outlines the reconstruction of the Fermi
surface in the temperature-field phase diagram. The zero-field ground state is
a compensated heavy-electron semi-metal, which is destroyed by magnetic field
through a cascade of field-induced transitions. Above 40 T, URu$_2$Si$_2$
appears to be a polarized heavy fermions metal with a large density of carriers
whose effective mass rapidly decreases with increasing magnetic polarization.


title: Decoherence in Solid State Qubits

abstract:
  Interaction of solid state qubits with environmental degrees of freedom
strongly affects the qubit dynamics, and leads to decoherence. In quantum
information processing with solid state qubits, decoherence significantly
limits the performances of such devices. Therefore, it is necessary to fully
understand the mechanisms that lead to decoherence. In this review we discuss
how decoherence affects two of the most successful realizations of solid state
qubits, namely, spin-qubits and superconducting qubits. In the former, the
qubit is encoded in the spin 1/2 of the electron, and it is implemented by
confining the electron spin in a semiconductor quantum dot. Superconducting
devices show quantum behavior at low temperatures, and the qubit is encoded in
the two lowest energy levels of a superconducting circuit. The electron spin in
a quantum dot has two main decoherence channels, a (Markovian) phonon-assisted
relaxation channel, due to the presence of a spin-orbit interaction, and a
(non-Markovian) spin bath constituted by the spins of the nuclei in the quantum
dot that interact with the electron spin via the hyperfine interaction. In a
superconducting qubit, decoherence takes place as a result of fluctuations in
the control parameters, such as bias currents, applied flux, and bias voltages,
and via losses in the dissipative circuit elements.


title: A Star Product for Differential Forms on Symplectic Manifolds

abstract:
  We present a star product between differential forms to second order in the
deformation parameter $\hbar$. The star product obtained is consistent with a
graded differential Poisson algebra structure on a symplectic manifold. The
form of the graded differential Poisson algebra requires the introduction of a
connection with torsion on the manifold, and places various constraints upon
it. The star product is given to second order in $\hbar^2$.


title: New Calculations of Stellar Wind Torques

abstract:
  Using numerical simulations of magnetized stellar winds, we carry out a
parameter study to find the dependence of the stellar wind torque on observable
parameters. We find that the power-law dependencies of the torque on parameters
is significantly different than what has been used in all spin evolution models
to date.


title:
Early SUSY discovery at LHC via sparticle cascade decays to same-sign
  and multimuon states

abstract:
  In the very early stages of LHC running, uncertainties in detector
performance will lead to large ambiguities in jet, electron and photon energy
measurements, along with inferred missing transverse energy. However, muon
detection should be quite straightforward, with the added benefit that muons
can be reliably detected down to transverse energies of order 5 GeV.
Supersymmetry discovery through multimuon channels has been extensively
explored in the literature, but always relying on hard ET^miss cuts. Here, we
quantify signal and background rates for same-sign (SS) dimuon and multimuon
production at the LHC without any ET^miss cuts. The LHC, operating at
\sqrt{s}=10 TeV, should be able to discover a signal over expected background
consistent with gluino pair production for m_{\tg}\alt 450 (550) GeV in the SS
dimuon plus \ge 4 jets state with just 0.1 (0.2) fb^{-1} of integrated
luminosity.


title:
Multiconfiguration Dirac-Hartree-Fock energy levels and transition
  probabilities for 3d^5 in Fe IV

abstract:
  Multiconfiguration Dirac-Hartree-Fock electric quadrupole (E2) and magnetic
dipole (M1) transition probabilities are reported for transitions between
levels of 3d^5 in [Fe IV]. The accuracy of the ab initio energy levels and the
agreement in the length and velocity forms of the line strength for the E2
transitions are used as indicators of accuracy. The present E2 and M1
transition probabilities are compared with earlier Breit-Pauli results and
other theories. An extensive set of transition probabilites with indicators of
accuracy are reported in Appendices A and B. Recommended values of A(E2) +
A(M1) are listed in Appendix C.


title: Quantum optical coherence tomography of a biological sample

abstract:
  Quantum optical coherence tomography (QOCT) makes use of an entangled-photon
light source to carry out dispersion-immune axial optical sectioning. We
present the first experimental QOCT images of a biological sample: an
onion-skin tissue coated with gold nanoparticles. 3D images are presented in
the form of 2D sections of different orientations.


title: Is planetary chaos related to evolutionary (phenotypic) rates?

abstract:
  After Laskar, the Lyapunov time in the solar system is about five millions
years (5.000.000 [years]). On the other hand, after Kimura, the evolutionary
(phenotypic) rate, for hominids, is 1/5.000.000 [1/years]. Why are these two
quantities so closely related? In this work, following a proposition by
Finlayson and Hutchings et al, I found an inequality, which relates Lyapunov
time and evolution rate. This inequality fits well with some known cases in
biological evolution.


title:
Aging dip and cumulative aging in hierarchical successive transition of
  stage-2 CoCl$_{2}$ graphite intercalation compound

abstract:
  Memory and aging behaviors in stage-2 CoCl$_{2}$ GIC ($T_{cu}$ = 8.9 K and
$T_{cl}$ = 6.9 K) have been studied using low frequency ($f$ = 0.1 Hz) AC
magnetic susceptibility ($\chi^{\prime}$ and $\chi^{\prime\prime}$) as well as
thermoremnant magnetization. There occurs a crossover from a cumulative aging
(mainly) with a partial memory effect for the domain-growth in the intermediate
state between $T_{cu}$ and $T_{cl}$ to an aging and memory in a spin glass
phase below $T_{cl}$. When the system is aged at single or multiple stop and
wait processes at stop temperatures $T_{s}$'s below $T_{cl}$ for wait times
$t_{s}$, the AC magnetic susceptibility shows single or multiple aging dips at
$T_{s}$'s on reheating. The depth of the aging dips is logarithmically
proportional to the wait time $t_{s}$. Very weak aging dip between $T_{cu}$ and
$T_{cl}$ indicates the existence of a partial memory effect. The sign of the
difference between the reference cooling and reference heating curves changes
from positive to negative on crossing $T_{cl}$ from the high $T$-side. The time
dependence of $\chi^{\prime}$ and $\chi^{\prime\prime}$ below $T_{cl}$ is
described by a scaling function of $\omega t$. its a local maximum at 6.5 K
just below $T_{cl}$, and drastically decreases with increasing $T$. The nature
of the cumulative aging between $T_{cl}$ and $T_{cu}$ is also examined.


title:
Correlative Spectral Analysis of Gamma-Ray Bursts using Swift-BAT and
  GLAST-GBM

abstract:
  We discuss the preliminary results of spectral analysis simulations involving
anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs)
using Swift's Burst Alert Telescope (BAT) and the Gamma-Ray Large Area Space
Telescope's (GLAST) Burst Monitor (GLAST-GBM), resulting in joint spectral
fits, including characteristic photon energy (Epeak) values, for a conservative
annual estimate of ~30 GRBs. The addition of BAT's spectral response will (i)
complement in-orbit calibration efforts of GBM's detector response matrices,
(ii) augment GLAST's low energy sensitivity by increasing the ~20-100 keV
effective area, (iii) facilitate ground-based follow-up efforts of GLAST GRBs
by increasing GBM's source localization precision, and (iv) help identify a
subset of non-triggered GRBs discovered via off-line GBM data analysis. Such
multi-wavelength correlative analyses, which have been demonstrated by
successful joint-spectral fits of Swift-BAT GRBs with other higher energy
detectors such as Konus-WIND and Suzaku-WAM, would enable the study of
broad-band spectral and temporal evolution of prompt GRB emission over three
energy decades, thus potentially increasing the science return without placing
additional demands upon mission resources throughout their contemporaneous
orbital tenure over the next decade.


title:
A local greedy algorithm and higher order extensions for global
  numerical continuation of analytically varying subspaces

abstract:
  We present a family of numerical implementations of Kato's ODE propagating
global bases of analytically varying invariant subspaces, of which the
first-order version is a surprising simple "greedy algorithm" that is both
stable and easy to program and the second-order version a relaxation of a
first-order scheme of Brin and Zumbrun. The method has application to numerical
Evans function computations used to assess stability of traveling-wave
solutions of time-evolutionary PDE.


title: The t-improper chromatic number of random graphs

abstract:
  We consider the $t$-improper chromatic number of the Erd{\H o}s-R{\'e}nyi
random graph $G(n,p)$. The t-improper chromatic number $\chi^t(G)$ of $G$ is
the smallest number of colours needed in a colouring of the vertices in which
each colour class induces a subgraph of maximum degree at most $t$. If $t = 0$,
then this is the usual notion of proper colouring. When the edge probability
$p$ is constant, we provide a detailed description of the asymptotic behaviour
of $\chi^t(G(n,p))$ over the range of choices for the growth of $t = t(n)$.


title: How Does a Dipolar Bose-Einstein Condensate Collapse?

abstract:
  We emphasize that the macroscopic collapse of a dipolar Bose-Einstein
condensate in a pancake-shaped trap occurs through local density fluctuations,
rather than through a global collapse to the trap center. This hypothesis is
supported by a recent experiment in a chromium condensate.


title: Emergent Spacetime and The Origin of Gravity

abstract:
  We present an exposition on the geometrization of the electromagnetic force.
We show that, in noncommutative (NC) spacetime, there always exists a
coordinate transformation to locally eliminate the electromagnetic force, which
is precisely the Darboux theorem in symplectic geometry. As a consequence, the
electromagnetism can be realized as a geometrical property of spacetime like
gravity. We show that the geometrization of the electromagnetic force in NC
spacetime is the origin of gravity, dubbed as the emergent gravity. We discuss
how the emergent gravity reveals a novel, radically different picture about the
origin of spacetime. In particular, the emergent gravity naturally explains the
dynamical origin of flat spacetime, which is absent in Einstein gravity. This
spacetime picture turns out to be crucial for a tenable solution of the
cosmological constant problem.


title: A Kinematical Approach to Conformal Cosmology

abstract:
  We present an alternative cosmology based on conformal gravity, as originally
introduced by H. Weyl and recently revisited by P. Mannheim and D. Kazanas.
Unlike past similar attempts our approach is a purely kinematical application
of the conformal symmetry to the Universe, through a critical reanalysis of
fundamental astrophysical observations, such as the cosmological redshift and
others. As a result of this novel approach we obtain a closed-form expression
for the cosmic scale factor R(t) and a revised interpretation of the space-time
coordinates usually employed in cosmology. New fundamental cosmological
parameters are introduced and evaluated. This emerging new cosmology does not
seem to possess any of the controversial features of the current standard
model, such as the presence of dark matter, dark energy or of a cosmological
constant, the existence of the horizon problem or of an inflationary phase.
Comparing our results with current conformal cosmologies in the literature, we
note that our kinematic cosmology is equivalent to conformal gravity with a
cosmological constant at late (or early) cosmological times. The cosmic scale
factor and the evolution of the Universe are described in terms of several
dimensionless quantities, among which a new cosmological variable delta emerges
as a natural cosmic time. The mathematical connections between all these
quantities are described in details and a relationship is established with the
original kinematic cosmology by L. Infeld and A. Schild. The mathematical
foundations of our kinematical conformal cosmology will need to be checked
against current astrophysical experimental data, before this new model can
become a viable alternative to the standard theory.


title:
Steady State Convergence Acceleration of the Generalized Lattice
  Boltzmann Equation with Forcing Term through Preconditioning

abstract:
  Several applications exist in which lattice Boltzmann methods (LBM) are used
to compute stationary states of fluid motions, particularly those driven or
modulated by external forces. Standard LBM, being explicit time-marching in
nature, requires a long time to attain steady state convergence, particularly
at low Mach numbers due to the disparity in characteristic speeds of
propagation of different quantities. In this paper, we present a preconditioned
generalized lattice Boltzmann equation (GLBE) with forcing term to accelerate
steady state convergence to flows driven by external forces. The use of
multiple relaxation times in the GLBE allows enhancement of the numerical
stability. Particular focus is given in preconditioning external forces, which
can be spatially and temporally dependent. In particular, correct forms of
moment-projections of source/forcing terms are derived such that they recover
preconditioned Navier-Stokes equations with non-uniform external forces. As an
illustration, we solve an extended system with a preconditioned lattice kinetic
equation for magnetic induction field at low magnetic Prandtl numbers, which
imposes Lorentz forces on the flow of conducting fluids. Computational studies,
particularly in three-dimensions, for canonical problems show that the number
of time steps needed to reach steady state is reduced by orders of magnitude
with preconditioning. In addition, the preconditioning approach resulted in
significantly improved stability characteristics when compared with the
corresponding single relaxation time formulation.


title:
Time-Reversal Symmetry Breaking and Spontaneous Anomalous Hall Effect in
  Fermi Fluids

abstract:
  We study the spontaneous non-magnetic time-reversal symmetry breaking in a
two-dimensional Fermi liquid without breaking either the translation symmetry
or the U(1) charge symmetry. Assuming that the low-energy physics is described
by fermionic quasiparticle excitations, we identified an "emergent" local
$U(1)^N$ symmetry in momentum space for an $N$-band model. For a large class of
models, including all one-band and two-band models, we found that the
time-reversal and chiral symmetry breaking can be described by the $U(1)^N$
gauge theory associated with this emergent local $U(1)^N$ symmetry. This
conclusion enables the classification of the time-reversal symmetry-breaking
states as types I and II, depending on the type of accompanying spatial
symmetry breaking. The properties of each class are studied. In particular, we
show that the states breaking both time-reversal and chiral symmetries are
described by spontaneously generated Berry phases. We also show examples of the
time-reversal symmetry-breaking phases in several different microscopically
motivated models and calculate their associated Hall conductance within a
mean-field approximation. The fermionic nematic phase with time-reversal
symmetry breaking is also presented and the possible realizations in strongly
correlated models such as the Emery model are discussed.


title: Bi-collinear antiferromagnetic order in the tetragonal $\alpha$-FeTe

abstract:
  By the first-principles electronic structure calculations, we find that the
ground state of PbO-type tetragonal $\alpha$-FeTe is in a bi-collinear
antiferromagnetic state, in which the Fe local moments ($\sim2.5\mu_B$) are
ordered ferromagnetically along a diagonal direction and antiferromagnetically
along the other diagonal direction on the Fe square lattice. This bi-collinear
order results from the interplay among the nearest, next nearest, and next next
nearest neighbor superexchange interactions $J_1$, $J_2$, and $J_3$, mediated
by Te $5p$-band. In contrast, the ground state of $\alpha$-FeSe is in the
collinear antiferromagnetic order, similar as in LaFeAsO and BaFe$_2$As$_2$.


title: Spaces with a Finite Family of Basic Functions

abstract:
  A space X is finite dimensional, locally compact and separable metrizable if
and only if X has a finite basic family: continuous functions Phi_1,...,Phi_n
of X to the reals, R, such that for all continuous f from X to R there are
g_1,..., g_n in C(R) satisfying
f(x)=g_1(Phi_1(x))+g_2(Phi_2(x))+...+g_n(Phi_n(x)) for all x in X. This give
the complete solution to four problems on basic functions posed by Sternfeld,
as well as questions posed by Hattori and others.


title: Counting the Closed Subgroups of Profinite Groups

abstract:
  The sets of closed and closed-normal subgroups of a profinite group carry a
natural profinite topology. Through a combination of algebraic and topological
methods the size of these subgroup spaces is calculated, and the spaces
partially classified up to homeomorphism.


title: Classifying Spaces of Subgroups of Profinite Groups

abstract:
  The set of all closed subgroups of a profinite carries a natural profinite
topology. This space of subgroups can be classified up to homeomorphism in many
cases, and tight bounds placed on its complexity as expressed by its scattered
height.


title: Entanglement generation in double-$\Lambda $ system

abstract:
  In this paper, we study the generation of entanglement in a double-$\Lambda $
system. Employing standard method of laser theory, we deduce the dynamic
evolution equation of the two-mode field. We analyze the available entanglement
criterion for double-$\Lambda $ system and the condition of entanglement
existence. Our results show that under proper parameters, the two-mode field
can entangled and amlified.


title:
Measurements of $\phi$ meson production in relativistic heavy-ion
  collisions at RHIC

abstract:
  We present results for the measurement of $\phi$ meson production via its
charged kaon decay channel $\phi \to K^+K^-$ in Au+Au collisions at
$\sqrt{s_{_{NN}}}=62.4$, 130, and 200 GeV, and in $p+p$ and $d$+Au collisions
at $\sqrt{s_{_{NN}}}=200$ GeV from the STAR experiment at the BNL Relativistic
Heavy Ion Collider (RHIC). The midrapidity ($|y|<0.5$) $\phi$ meson transverse
momentum ($p_{T}$) spectra in central Au+Au collisions are found to be well
described by a single exponential distribution. On the other hand, the $p_{T}$
spectra from $p+p$, $d$+Au and peripheral Au+Au collisions show power-law tails
at intermediate and high $p_{T}$ and are described better by Levy
distributions. The constant $\phi/K^-$ yield ratio vs beam species, collision
centrality and colliding energy is in contradiction with expectations from
models having kaon coalescence as the dominant mechanism for $\phi$ production
at RHIC. The $\Omega/\phi$ yield ratio as a function of $p_{T}$ is consistent
with a model based on the recombination of thermal $s$ quarks up to $p_{T}\sim
4$ GeV/$c$, but disagrees at higher transverse momenta. The measured nuclear
modification factor, $R_{dAu}$, for the $\phi$ meson increases above unity at
intermediate $p_{T}$, similar to that for pions and protons, while $R_{AA}$ is
suppressed due to the energy loss effect in central Au+Au collisions. Number of
constituent quark scaling of both $R_{cp}$ and $v_{2}$ for the $\phi$ meson
with respect to other hadrons in Au+Au collisions at $\sqrt{s_{_{NN}}}$=200 GeV
at intermediate $p_{T}$ is observed. These observations support quark
coalescence as being the dominant mechanism of hadronization in the
intermediate $p_{T}$ region at RHIC.


title:
The Erd\"os-Falconer distance problem on the unit sphere in vector
  spaces over finite fields

abstract:
  art, Iosevich, Koh and Rudnev (2007) show, using Fourier analysis method,
that the finite Erd\"os-Falconer distance conjecture holds for subsets of the
unit sphere in $\mathbbm{F}_q^d$. In this note, we give a graph theoretic proof
of this result.


title:
Thermodynamics of ultracold trapped gases. Generalized mechanical
  variables, equation of state and heat capacity

abstract:
  The thermodynamics framework of an interacting quantum gas trapped by an
arbitrary external potential is reviewed. We show that for each confining
potential, in the thermodynamic limit, there emerge "generalized" volume and
pressure variables ${\cal V}$ and ${\cal P}$, that replace the usual volume and
hydrostatic pressure of a uniform system. This scheme is validated with the
derivation of the virial expansion of the grand potential. We show that this
approach yields experimentally amenable procedures to find the equation of
state of the fluid, ${\cal P} = {\cal P}({\cal V}/N,T)$ with $N$ the number of
atoms, as well as its heat capacity at constant generalized volume $C_{\cal V}
= C_{\cal V}({\cal V},N,T)$. With these two functions, all the thermodynamics
properties of the system may be found. As specific examples we study weakly
interacting Bose gases trapped by harmonic and by linear quadrupolar potentials
within the Hartree-Fock approximation. Comparisons with experimental results of
a $^{23}$Na ultracold gas are also presented. We claim that this route should
provide an additional and useful tool to analyze both the thermodynamic
variables of a trapped gas as well as its elementary excitations.


title: Thermal states of the Kitaev honeycomb model: a Bures metric analysis

abstract:
  We analyze the Bures metric over the canonical thermal states for the Kitaev
honeycomb mode. In this way the effects of finite temperature on topological
phase transitions can be studied. Different regions in the parameter space of
the model can be clearly identified in terms of different temperature scaling
behavior of the Bures metric tensor. Furthermore, we show a simple relation
between the metric elements and the crossover temperature between the
quasi-critical and the quasi-classical regions. These results extend the ones
of [29,30] to finite temperatures.


title: Large deviations for the leaves in some random trees

abstract:
  Large deviation principles and related results are given for a class of
Markov chains associated to the "leaves" in random recursive trees and
preferential attachment random graphs, as well as the "cherries" in Yule trees.
  In particular, the method of proof, combining analytic and Dupuis-Ellis type
path arguments, allows for an explicit computation of the large deviation
pressure.


title:
The Accuracy of Supermassive Black Hole Masses Determined by the
  Single-Epoch-Spectrum (Dibai) Method

abstract:
  The first set of supermassive black hole mass estimates, published from 1980
to 1984 by E. A. Dibai, are shown to be in excellent agreement with recent
reverberation-mapping estimates. Comparison of the masses of 17 AGNs covering a
mass range from about 10^6 to 10^9 solar masses shows that the Dibai mass
estimates agree with reverberation-mapping mass estimates to significantly
better than 0.3 dex and were, on average, only 0.14 dex (~ 40%) systematically
lower than masses obtained from reverberation mapping. This surprising
agreement with the results of over a quarter of a century ago has important
implication for the structure and kinematics of AGNs and implies that AGNs are
very similar. Our results give strong support to the use of the
single-epoch-spectrum (Dibai) method for investigating the co-evolution of
supermassive black holes and their host galaxies.


title:
The Imaginary Sliding Window As a New Data Structure for Adaptive
  Algorithms

abstract:
  The scheme of the sliding window is known in Information Theory, Computer
Science, the problem of predicting and in stastistics. Let a source with
unknown statistics generate some word $... x_{-1}x_{0}x_{1}x_{2}...$ in some
alphabet $A$. For every moment $t, t=... $ $-1, 0, 1, ...$, one stores the word
("window") $ x_{t-w} x_{t-w+1}... x_{t-1}$ where $w$,$w \geq 1$, is called
"window length". In the theory of universal coding, the code of the $x_{t}$
depends on source ststistics estimated by the window, in the problem of
predicting, each letter $x_{t}$ is predicted using information of the window,
etc. After that the letter $x_{t}$ is included in the window on the right,
while $x_{t-w}$ is removed from the window. It is the sliding window scheme.
This scheme has two merits: it allows one i) to estimate the source statistics
quite precisely and ii) to adapt the code in case of a change in the source'
statistics. However this scheme has a defect, namely, the necessity to store
the window (i.e. the word $x_{t-w}... x_{t-1})$ which needs a large memory size
for large $w$. A new scheme named "the Imaginary Sliding Window (ISW)" is
constructed. The gist of this scheme is that not the last element $x_{t-w}$ but
rather a random one is removed from the window. This allows one to retain both
merits of the sliding window as well as the possibility of not storing the
window and thus significantly decreasing the memory size.


title:
Late-time acceleration and Phantom Divide Line Crossing with Non-minimal
  Coupling and Lorentz Invariance Violation

abstract:
  We consider two alternative dark energy models: a Lorentz invariance
preserving model with a nonminimally coupled scalar field and a Lorentz
invariance violating model with a minimally coupled scalar field. We study
accelerated expansion and dynamics of equation of state parameter in these
scenarios. While a minimally coupled scalar field has not the capability to be
a successful dark energy candidate with cosmological constant line crossing, a
nonminimally coupled scalar field in the presence of Lorentz invariance or a
minimally coupled scalar field with Lorentz invariance violation have this
capability. In the later case, accelerated expansion and phantom divide line
crossing are the results of interactive nature of this Lorentz violating
scenario.


title:
Polynomial Translation Weingarten Surfaces in 3-dimensional Euclidean
  space

abstract:
  In this paper we will classify those translation surfaces in E3 involving
polynomials which are Weingarten surfaces. We analyze Weingarten translation
surfaces satisfying 2aH + bK = 0. We study also other types of translation
surfaces, involving power functions, for which the second Gaussian curvature
vanishes.


title: Reconnection of superfluid vortex bundles

abstract:
  Using the vortex filament model and the Gross Pitaevskii nonlinear
Schroedinger equation, we show that bundles of quantised vortex lines in helium
II are structurally robust and can reconnect with each other maintaining their
identity. We discuss vortex stretching in superfluid turbulence and show that,
during the bundle reconnection process, Kelvin waves of large amplitude are
generated, in agreement with the finding that helicity is produced by nearly
singular vortex interactions in classical Euler flows.


title: On parsimonious edge-colouring of graphs with maximum degree three

abstract:
  In a graph $G$ of maximum degree $\Delta$ let $\gamma$ denote the largest
fraction of edges that can be $\Delta$ edge-coloured. Albertson and Haas showed
that $\gamma \geq 13/15$ when $G$ is cubic . We show here that this result can
be extended to graphs with maximum degree 3 with the exception of a graph on 5
vertices. Moreover, there are exactly two graphs with maximum degree 3 (one
being obviously the Petersen graph) for which $\gamma = 13/15$. This extends a
result given by Steffen. These results are obtained by using structural
properties of the so called $\delta$-minimum edge colourings for graphs with
maximum degree 3. Keywords : Cubic graph; Edge-colouring


title: Balanced metrics on non-Kahler Calabi-Yau threefolds

abstract:
  We construct balanced metrics on the family of non-K\"ahler Calabi-Yau
threefolds that are obtained by smoothing after contracting $(-1,-1)$-rational
curves on K\"ahler Calabi-Yau threefold. As an application, we construct
balanced metrics on complex manifolds diffeomorphic to connected sum of $k\geq
2$ copies of $S^3\times S^3$.


title: X-ray observations of IC348 in light of an updated cluster census

abstract:
  IC348 is an excellent laboratory for studies of low-mass star formation being
nearby, compact and rich. A Chandra observation was carried out early in the
satellite's lifetime. The extensive new data in optical and infrared
wavelengths accumulated in subsequent years have changed the cluster census
calling for a re-analysis of the X-ray data.


title: Simulation of Z plus Graviton/Unparticle Production at the LHC

abstract:
  Theories with extra dimensions have gained much interest in recent years as
candidates for a possible extension of the SM. The observation of large extra
dimensions through real graviton emission is one of the most popular related
new phenomena. The main experimental signatures from graviton emission are
production of single jet and single photon events, which have been studied in
great detail. This work describes the implementation of graviton production
together with either a Z or a photon in Pythia 8. The potential of using Z plus
graviton production at the LHC as a complementary channel is also studied. For
completeness, this work also includes the more recently proposed scenario of
unparticle emission, since the effective theory of unparticles to some extent
represents a generalization of the large extra dimension model.


title: Decoherence and relaxation in the interacting quantum dot system

abstract:
  In this paper we study the low temperature kinetics of the electrons in the
system composed of a quantum dot connected to two leads by solving the equation
of motion. The decoherence and the relaxation of the system caused by the gate
voltage noise and electron-phonon scattering are investigated. In order to take
account of the strong correlation of the electrons in this system, the
quasi-exact wave functions are calculated using an improved matrix product
states algorithm. This algorithm enables us to calculate the wave functions of
the ground state and the low lying excited states with satisfied accuracy and
thus enables us to study the kinetics of the system more effectively. It is
found that although both of these two mechanisms are proportional to the
electron number operator in the dot, the kinetics are quite different. The
noise induced decoherence is much more effective than the energy relaxation,
while the energy relaxation and decoherence time are of the same order for the
electron-phonon scattering. Moreover, the noise induced decoherence increases
with the lowering of the dot level, but the relaxation and decoherence due to
the electron-phonon scattering decrease.


title: Stability in Generalized Modified Gravity

abstract:
  The stability issue of a large class of modified gravitational models is
discussed with particular emphasis to de Sitter solutions. Three approaches are
briefly presented and the generalization to more general cases is mentioned.


title:
Ultraviolet divergences of flavor changing amplitudes in the littlest
  Higgs model with T-parity

abstract:
  Flavor changing neutral current processes are studied in the littlest Higgs
model with T-parity. It is found that the logarithmic divergence reported
earlier in Z boson flavor changing processes is exactly canceled by
contributions from additional interaction terms of heavy fermions and the Z
boson. Phenomenological impact on the K --> pi nu nu_bar processes is
discussed.


title: Lynds 1622: a nearby star forming cloud projected on Orion B?

abstract:
  We present results of optical spectroscopic and photometric observation of
the pre-main sequence stars associated with the cometary shaped dark cloud
Lynds 1622, and 12CO and 13CO observations of the cloud. We determined the
effective temperatures and luminosities of 14 pre-main sequence stars
associated with the cloud from their positions in the Hertzsprung--Russell
diagram, as well as constructed their spectral energy distributions using
optical, 2MASS and Spitzer IRAC and MIPS data. We derived physical parameters
of L1622 from the molecular observations. Our results are not compatible with
the assumption that L1622 lies on the near side of the Orion-Eridanus loop, but
suggest that L1622 is as distant as Orion B. At a distance of 400 pc the mass
of the cloud, derived from our CO data, is 1100 solar masses, its star
formation efficiency is 1.8%, and the average age of its low-mass pre-main
sequence star population is about 1 million years.


title: Kohonen neural networks and genetic classification

abstract:
  We discuss the property of a.e. and in mean convergence of the Kohonen
algorithm considered as a stochastic process. The various conditions ensuring
the a.e. convergence are described and the connection with the rate decay of
the learning parameter is analyzed. The rate of convergence is discussed for
different choices of learning parameters. We proof rigorously that the rate of
decay of the learning parameter which is most used in the applications is a
sufficient condition for a.e. convergence and we check it numerically. The aim
of the paper is also to clarify the state of the art on the convergence
property of the algorithm in view of the growing number of applications of the
Kohonen neural networks. We apply our theorem and considerations to the case of
genetic classification which is a rapidly developing field.


title: Early spectroscopy and photometry of the new outburst of V1647 Ori

abstract:
  Broad-band photometric and moderate-resolution spectroscopic observations of
the young eruptive star V1647 Ori, obtained between 28 August and 1 September
2008, are presented. The observed magnitudes and emission line equivalent
widths of the star indicate that the initial conditions of the new outburst are
very similar to those of the previous one in 2004.


title: Tracking of supergranules - Does it make any sense?

abstract:
  The motions of the plasma and structures in and below the solar photosphere
is not well understood. The results obtained using various methods cannot be in
general considered as consistent, especially in details. In this contribution
we show a summary of the results obtained by the method we have developed
recently. To study the photospheric dynamics we apply the local correlation
tracking algorithm to the series of full-disc Dopplergrams obtained by
Michelson Doppler Imager (MDI) aboard the SOHO satelite. The dominant structure
recorded in Dopplergrams is the supergranulation. Under the assumtion that the
supergranules are carried by the flow field of the larger scale, we study
properties of this underlying velocity field. We perform comparative tests with
synthetic data with known properties and with results of the time-distance
helioseismology with a great success. A few case studies are shown to
demonstrate the performance of the method. We believe that tracking of
supergranules makes a perfect sense when studying the large-scale flows in the
solar photosphere. The method we demonstrate is suitable to detect large-scale
velocity field with effective resolution of 60" and random error of 15 m/s. We
believe that our method may provide a powerful tool for studies related to the
dynamic behaviour of plasmas in the solar photosphere.


title: Optical bistability in a GaAs based polariton diode

abstract:
  We report on a new type of optical nonlinearity in a polariton p-i-n
microcavity. Abrupt switching between the strong and weak coupling regime is
induced by controlling the electric field within the cavity. As a consequence
bistable cycles are observed for low optical powers (2-3 orders of magnitude
less than for Kerr induced bistability). Signatures of switching fronts
propagating through the whole 300 microns x 300 microns mesa surface are
evidenced.


title: Star Forming Regions in Cassiopeia

abstract:
  This chapter describes the Galactic star forming regions in the constellation
Cassiopeia, in the Galactic coordinate range 120 deg < l < 130 deg, -5 deg < b
< +15 deg. At b > 10 deg the nearby clouds L1333 and L1340 are found in this
region. The local arm of the Galaxy in Cassiopeia contains only a few star
forming regions, smaller and less active than the OB associations of the
neighboring Cepheus. Five members of this system, LkHalpha 198 and its
environment, L1287, L1293, L1302 / NGC 255, and S187 are discussed. Several
more distant OB associations and giant star forming regions in Cassiopeia are
associated with the Perseus arm at 2.0-3.0 kpc. Among these, the Herbig Be star
MWC 1080 is discussed in this chapter.


title:
Photoproduction of spin and charge carriers in halogen-bridged binuclear
  platinum chain complexes

abstract:
  Nonlinear lattice relaxation of photoexcited diplatinum-halide chain
compounds is theoretically investigated within a one-dimensional extended
Peierls-Hubbard model. We first illuminate the whole relaxation scenario in
terms of variational wave functions and then visualize each relaxation channel
numerically integrating the Schr\"odinger equation. High-energy excitations
above the electron-hole continuum tend to relax into polarons, while excitons
pumped within the optical gap, unless luminescent, turn into solitonic states
nonradiatively. Neutral and charged solitons coexist as stable photoproducts,
which has never been observed in conventional platinum-halide chains, and they
are highly resonant on the occasion of their birth and geminate recombination.


title: Star Forming Regions in Cepheus

abstract:
  The northern Milky Way in the constellation of Cepheus (100 deg < l < 120
deg; 0 deg < b < 20 deg) contains several star forming regions. The molecular
clouds of the Cepheus Flare region at b > 10 deg, are sites of low and
intermediate mass star formation located between 200 and 450 pc from the Sun.
Three nearby OB associations, Cep OB2, Cep OB3, Cep OB4, located at 600-800 pc,
are each involved in forming stars, like the well known high mass star forming
region S140 at 900 pc. The reflection nebula NGC 7129 around 1 kpc harbors
young, compact clusters of low and intermediate mass stars. The giant star
forming complex NGC 7538 and the young open cluster NGC 7380, associated with
the Perseus arm, are located at d > 2 kpc.


title: Ultra-high energy cosmic rays threshold in Randers-Finsler space

abstract:
  Kinematics in Finsler space is used to study the propagation of ultra high
energy cosmic rays particles through the cosmic microwave background radiation.
We find that the GZK threshold is lifted dramatically in Randers-Finsler space.
A tiny deformation of spacetime from Minkowskian to Finslerian allows more
ultra-high energy cosmic rays particles arrive at the earth. It is suggested
that the lower bound of particle mass is related with the negative second
invariant speed in Randers-Finsler space.


title:
Hamiltonian Analysis of non-chiral Plebanski Theory and its
  Generalizations

abstract:
  We consider non-chiral, full Lorentz group-based Plebanski formulation of
general relativity in its version that utilizes the Lagrange multiplier field
Phi with "internal" indices. The Hamiltonian analysis of this version of the
theory turns out to be simpler than in the previously considered in the
literature version with Phi carrying spacetime indices. We then extend the
Hamiltonian analysis to a more general class of theories whose action contains
scalars invariants constructed from Phi. Such theories have recently been
considered in the context of unification of gravity with other forces. We show
that these more general theories have six additional propagating degrees of
freedom as compared to general relativity, something that has not been
appreciated in the literature treating them as being not much different from
GR.


title: The q-exponential family in statistical physics

abstract:
  The notion of generalised exponential family is considered in the restricted
context of nonextensive statistical physics. Examples are given of models
belonging to this family. In particular, the q-Gaussians are discussed and it
is shown that the configurational probability distributions of the
microcanonical ensemble belong to the q-exponential family.


title:
Propagation of nonadiabatic magnetoacoustic waves in a threaded
  prominence with mass flows

abstract:
  High resolution observations of solar filaments suggest the presence of
groups of prominence threads, i.e. the fine-structures of prominences, which
oscillate coherently (in phase). In addition, mass flows along threads have
been often observed. Here, we investigate the effect of mass flows on the
collective fast and slow nonadiabatic magnetoacoustic wave modes supported by
systems of prominence threads. Prominence fine-structures are modeled as
parallel, homogeneous and infinite cylinders embedded in a coronal environment.
The magnetic field is uniform and parallel to the axis of threads.
Configurations of identical and nonidentical threads are both explored. We
apply the T-matrix theory of acoustic scattering to obtain the oscillatory
frequency and the eigenfunctions of linear magnetosonic disturbances. We find
that the existence of wave modes with a collective dynamics, i.e. those that
produce significant perturbations in all threads, is only possible when the
Doppler-shifted individual frequencies of threads are very similar. This can be
only achieved for very particular values of the plasma physical conditions and
flow velocities within threads.


title:
New dispersion relations in the description of $\pi\pi$ scattering
  amplitudes

abstract:
  We present a set of once subtracted dispersion relations which implement
crossing symmetry conditions for the $\pi\pi$ scattering amplitudes below 1
GeV. We compare and discuss the results obtained for the once and twice
subtracted dispersion relations, known as Roy's equations, for three $\pi\pi$
partial JI waves, S0, P and S2. We also show that once subtracted dispersion
relations provide a stringent test of crossing and analyticity for $\pi\pi$
partial wave amplitudes, remarkably precise in the 400 to 1.1 GeV region, where
the resulting uncertainties are significantly smaller than those coming from
standard Roy's equations, given the same input.


title:
New example of CP violation from search for the permanent electric
  dipole moment of Cs atoms

abstract:
  Using special capacitors three experiments to search for a permanent electric
dipole moment (EDM) of Cesium atom were completed. The electric susceptibility
xe of Cs vapor varies in direct proportion to the density N, where xe =70 when
N=7.37*1022 m-3! The relationship between xe of Cs vapor and the absolute
temperatures T is xe =B/T, where the slope B=320(k) as polar molecules
H2O(B=1.50(k)). Its capacitance C at different voltage V was measured. The C-V
curve shows that the saturation polarization of Cs vapor has be observed when
the field E=7.4*104V/m. Our measurements give the EDM of an Cs atom :
dCs=2.97*10-29 C.m=1.86*10-8 e.cm. New example of CP (charge conjugation and
parity) violation occurred in Cs atoms. Our results are easy to be repeated
because the details of the experiment are described in the article.


title: Non-extensive equilibration in relativistic matter

abstract:
  We present a view of the non-extensive thermodynamics based on general
composition rules. A formal logarithm maps these rules to the addition, which
can be used to generate stationary distributions by standard techniques. We
review the most commonly used rules and as an application we discuss the
Tsallis-Pareto distribution of transverse momenta of energetic hadrons, which
emerge from relativistic heavy-ion collisions.


title:
Clover improvement for stout-smeared 2+1 flavour SLiNC fermions:
  perturbative results

abstract:
  For the Stout Link Non-perturbative Clover (SLiNC) action we determine in
one-loop lattice perturbation theory the critical hopping parameter $\kappa_c$
and the clover parameter $c_{SW}$ which is needed for $\mathcal{O}(a)$
improvement. Performing this calculation off-shell we are also able to compute
the non gauge invariant quark field improvement coefficient $c_{NGI}$.
Additionally, we present first results for the renormalization factors of the
scalar, pseudoscalar, vector and axial vector currents. We discuss mean field
improvement for the SLiNC action.


title: Tricritical O(n) models in two dimensions

abstract:
  We show that the exactly solved low-temperature branch of the two-dimensional
O($n$) model is equivalent with an O($n$) model with vacancies and a different
value of $n$. We present analytic results for several universal parameters of
the latter model, which is identified as a tricritical point. These results
apply to the range $n \leq 3/2$, and include the exact tricritical point, the
conformal anomaly and a number of scaling dimensions, among which the thermal
and magnetic exponent, the exponent associated with crossover to ordinary
critical behavior, and to tricritical behavior with cubic symmetry. We describe
the translation of the tricritical model in a Coulomb gas. The results are
verified numerically by means of transfer-matrix calculations. We use a
generalized ADE model as an intermediary, and present the expression of the
one-point distribution function in that language. The analytic calculations are
done both for the square and the hexagonal lattice.


title: On the curvature of biquotients

abstract:
  As a means to better understanding manifolds with positive curvature, there
has been much recent interest in the study of non-negatively curved manifolds
which contain either a point or an open dense set of points at which all
2-planes have positive curvature. We study infinite families of biquotients
defined by Eschenburg and Bazaikin from this viewpoint, together with torus
quotients of $S^3 \x S^3$.


title:
Big-Bang Nucleosynthesis Reactions Catalyzed by a Long-Lived Negatively
  Charged Leptonic Particle

abstract:
  An accurate quantum three-body calculation is performed for the new type of
big-bang nucleosynthesis (BBN) reactions that are catalyzed by a long-lived
negatively-charged, massive leptonic particle (called X^-) such as the
supersymmetric (SUSY) particle stau. The reactions studied here includes, i)
4He-transfer reactions such as (4He X)+d --> 6Li+X, ii) radiative capture
reactions such as (7Be X)+ p --> (8B X) + gamma, iii) three-body breakup
reactions such as (7Li X)+ p --> 4He+4He+X, iv) charge-exchange reactions such
as (p X)+4He -->(4He X) +p, and v) neutron induced reactions such as (8Be X)+ n
-->9Be+X, where (A X) denotes a Coulombic bound state of a nucleus A and X^-.
In recent papers it has been claimed that some of the catalyzed BBN reactions
have significantly large cross sections so as to markedly change the abundances
of some elements, not only giving a solution to the 6Li-7Li problem (calculated
underproduction of 6Li by a factor of 1000 and overproduction of 7Li+7Be by a
factor of nearly 3) but also imposing strong restrictions on the lifetime and
the primordial abundance of X^-. However, most of the calculations of these
reaction cross sections in the literature were performed assuming too naive
models or approximations that are unsuitable for the complicated low-energy
nuclear reactions. We use a high-accuracy few-body calculational method
developed by the authors, and provide precise cross sections and rates of these
catalyzed BBN reactions for use in the BBN network calculation.


title: Instantons and Spin-Flavor effects in Hadron Physics

abstract:
  We discuss the role of instantons in the spectroscopy of ordinary and exotic
hadrons as well as in high energy reactions. We argue that the instanton
induced flavor- and spin-dependent quark-quark and quark-gluon interactions can
explain many features of the hadron spectrum. The observed anomalous spin and
flavor effects in various reactions with hadrons can also be understood within
the instanton model for QCD vacuum.


title:
Tuning of metal-insulator transition of two-dimensional electrons at
  parylene/SrTiO$_3$ interface by electric field

abstract:
  Electrostatic carrier doping using a field-effect-transistor structure is an
intriguing approach to explore electronic phases by critical control of carrier
concentration. We demonstrate the reversible control of the insulator-metal
transition (IMT) in a two dimensional (2D) electron gas at the interface of
insulating SrTiO$_3$ single crystals. Superconductivity was observed in a
limited number of devices doped far beyond the IMT, which may imply the
presence of 2D metal-superconductor transition. This realization of a
two-dimensional metallic state on the most widely-used perovskite oxide is the
best manifestation of the potential of oxide electronics.


title:
On asymptotic stability of ground states of NLS with a finite bands
  periodic potential in 1D

abstract:
  We consider a nonlinear Schroedinger equation with a finite bands periodic
potential in R . We assume the existence of an orbitally stable family of
ground states. We prove that under appropriate hypotheses the ground states are
asymptotically stable.


title:
The diverse broad-band light-curves of Swift GRBs reproduced with the
  cannonball model

abstract:
  Two radiation mechanisms, inverse Compton scattering (ICS) and synchrotron
radiation (SR), suffice within the cannonball (CB) model of long gamma ray
bursts (LGRBs) and X-ray flashes (XRFs) to provide a very simple and accurate
description of their observed prompt emission and afterglows. Simple as they
are, the two mechanisms and the burst environment generate the rich structure
of the light curves at all frequencies and times. This is demonstrated for 33
selected Swift LGRBs and XRFs, which are well sampled from early until late
time and faithfully represent the entire diversity of the broad-band light
curves of Swift LGRBs and XRFs. Their prompt gamma-ray and X-ray emission is
dominated by ICS of `glory' light. During their fast decline phase, ICS is
taken over by SR, which dominates their broad-band afterglow. The pulse shape
and spectral evolution of the gamma-ray peaks and the early-time X-ray flares,
and even the delayed optical `humps' in XRFs, are correctly predicted. The
`canonical' and non-canonical X-ray light curves and the chromatic behaviour of
the broad-band afterglows are well reproduced. In particular, in canonical
X-ray light curves, the initial fast decline and rapid softening of the prompt
emission, the transition to the plateau phase, the subsequent gradual
steepening of the plateau to an asymptotic power-law decay, and the transition
from chromatic to achromatic behaviour of the light curves agrees well with
those predicted by the CB model. The Swift early-time data on XRF 060218 are
inconsistent with a black-body emission from a shock break-out through a
stellar envelope. Instead, they are well described by ICS of glory light by a
jet breaking out from SN2006aj.


title:
Destabilization of long-wavelength Love and Stoneley waves in slow
  sliding

abstract:
  Love waves are dispersive interfacial waves that are a mode of response for
anti-plane motions of an elastic layer bonded to an elastic half-space.
Similarly, Stoneley waves are interfacial waves in bonded contact of dissimilar
elastic half-spaces, when the displacements are in the plane of the solids. It
is shown that in slow sliding, long wavelength Love and Stoneley waves are
destabilized by friction. Friction is assumed to have a positive instantaneous
logarithmic dependence on slip rate and a logarithmic rate weakening behavior
at steady-state.
  Long wavelength instabilities occur generically in sliding with rate- and
state-dependent friction, even when an interfacial wave does not exist. For
slip at low rates, such instabilities are quasi-static in nature, i.e., the
phase velocity is negligibly small in comparison to a shear wave speed. The
existence of an interfacial wave in bonded contact permits an instability to
propagate with a speed of the order of a shear wave speed even in slow sliding,
indicating that the quasi-static approximation is not a valid one in such
problems.

categories: math-ph cond-mat.mtrl-sci math.MP physics.geo-ph


title:
Time-dependent and Non-BPS Solutions in N=6 Superconformal Chern-Simons
  Theory

abstract:
  We study a class of classical solutions of three-dimensional N=6
superconformal Chern-Simons theory coupled with U(N) \times U(N) bi-fundamental
matter fields. Especially, time evolutions of fuzzy spheres are discussed for
both massless and massive cases. For the massive case, there are a variety of
solutions having different behaviors according to the value of the mass. In
addition to the time-dependent solutions, we analyze non-BPS static solutions
which represent parallel M5/M5 or M5/anti-M5-branes suspended by multiple
M2-branes. These solutions are similar to the fundamental strings connecting
two parallel (anti) Dp-branes in perturbative string theory. A moving M5-brane
and domain wall solutions with constant velocity that are obtained by the
Lorentz boost of the known BPS solutions are briefly addressed.


title: Anderson localization and the Planck length as source of disorder

abstract:
  The role of disorder on wave propagation through the universe is studied.
Assuming space fluctuations of the order of the Planck length and the size of
the universe as the corresponding localization length for the background
radiation, we obtain the exponent (close to unity) in the power law
relationship between these quantities. This suggests that the role of Anderson
localization is not negligible at cosmological scales.


title: New multisite observations of Delta Scuti stars V624 Tauri and HD 23194

abstract: The preliminary results of STEPHI 2006 campaign are reported.


title:
On contingent claims pricing in incomplete markets: A risk sharing
  approach

abstract:
  In an incomplete market setting, we consider two financial agents, who wish
to price and trade a non-replicable contingent claim. Assuming that the agents
are utility maximizers, we propose a transaction price which is a result of the
minimization of a convex combination of their utility differences. We call this
price the risk sharing price, we prove its existence for a large family of
utility functions and we state some of its properties. As an example, we
analyze extensively the case where both agents report exponential utility.


title: Perfect Derived Categories of Positively Graded DG Algebras

abstract:
  We investigate the perfect derived category dgPer(A) of a positively graded
differential graded (dg) algebra A whose degree zero part is a dg subalgebra
and semisimple as a ring. We introduce an equivalent subcategory of dgPer(A)
whose objects are easy to describe, define a t-structure on dgPer(A) and study
its heart. We show that dgPer(A) is a Krull-Remak-Schmidt category. Then we
consider the heart in the case that A is a Koszul ring with differential zero
satisfying some finiteness conditions.


title: Heat-flow monotonicity of Strichartz norms

abstract:
  Most notably we prove that for $d=1,2$ the classical Strichartz norm $$\|e^{i
s\Delta}f\|_{L^{2+4/d}_{s,x}(\mathbb{R}\times\mathbb{R}^d)}$$ associated to the
free Schr\"{o}dinger equation is nondecreasing as the initial datum $f$ evolves
under a certain quadratic heat-flow.


title: A Computational Study on Emotions and Temperament in Multi-Agent Systems

abstract:
  Recent advances in neurosciences and psychology have provided evidence that
affective phenomena pervade intelligence at many levels, being inseparable from
the cognitionaction loop. Perception, attention, memory, learning,
decisionmaking, adaptation, communication and social interaction are some of
the aspects influenced by them. This work draws its inspirations from
neurobiology, psychophysics and sociology to approach the problem of building
autonomous robots capable of interacting with each other and building
strategies based on temperamental decision mechanism. Modelling emotions is a
relatively recent focus in artificial intelligence and cognitive modelling.
Such models can ideally inform our understanding of human behavior. We may see
the development of computational models of emotion as a core research focus
that will facilitate advances in the large array of computational systems that
model, interpret or influence human behavior. We propose a model based on a
scalable, flexible and modular approach to emotion which allows runtime
evaluation between emotional quality and performance. The results achieved
showed that the strategies based on temperamental decision mechanism strongly
influence the system performance and there are evident dependency between
emotional state of the agents and their temperamental type, as well as the
dependency between the team performance and the temperamental configuration of
the team members, and this enable us to conclude that the modular approach to
emotional programming based on temperamental theory is the good choice to
develop computational mind models for emotional behavioral Multi-Agent systems.


title: Equivariant Sheaves on Flag Varieties

abstract:
  We show that the Borel-equivariant derived category of sheaves on the flag
variety of a complex reductive group is equivalent to the perfect derived
category of dg modules over the extension algebra of the direct sum of the
simple equivariant perverse sheaves. This proves a conjecture of Soergel and
Lunts in the case of flag varieties.


title: Radiation Damage Studies of Silicon Photomultipliers

abstract:
  We report on the measurement of the radiation hardness of silicon
photomultipliers (SiPMs) manufactured by
  Fondazione Bruno Kessler in Italy (1 mm$^2$ and 6.2 mm$^2$), Center of
Perspective Technology and Apparatus in Russia (1 mm$^2$ and 4.4 mm$^2$), and
Hamamatsu Corporation in Japan (1 mm$^2$). The SiPMs were irradiated using a
beam of 212 MeV protons at Massachusetts General Hospital, receiving fluences
of up to $3 \times 10^{10}$ protons per cm$^2$ with the SiPMs at operating
voltage. Leakage currents were read continuously during the irradiation. The
delivery of the protons was paused periodically to record scope traces in
response to calibrated light pulses to monitor the gains, photon detection
efficiencies, and dark counts of the SiPMs. The leakage current and dark noise
are found to increase with fluence. Te leakage current is found to be
proportional to the mean square deviation of the noise distribution, indicating
the dark counts are due to increased random individual pixel activation, while
SiPMs remain fully functional as photon detectors. The SiPMs are found to
anneal at room temperature with a reduction in the leakage current by a factor
of 2 in about 100 days.


title: Constraining Light Bosons with Radiative $\Upsilon(1S)$ Decays

abstract:
  Light bosons can be found in large classes of theories beyond the Standard
Model. These light bosons may not be ruled out by current experiments and,
indeed, may even provide an explanation for some anomalous experimental
results. The radiative decays of quarkonium ($c \bar c, b \bar b$) states offer
a promising opportunity to investigate such light bosons. Specifically, we
investigate the reach that current CLEO data can have on models with light
scalar and pseudoscalar bosons.


title: A thermodynamic switch for chromosome colocalization

abstract:
  A general model for the early recognition and colocalization of homologous
DNA sequences is proposed. We show, on a thermodynamic ground, how the distance
between two homologous DNA sequences is spontaneously regulated by the
concentration and affinity of diffusible mediators binding them, which act as a
switch between two phases corresponding to independence or colocalization of
pairing regions.


title: Mass loss and evolution of hot massive stars

abstract:
  We discuss the role of mass loss for the evolution of the most massive stars,
highlighting the role of the predicted bi-stability jump that might be relevant
for the evolution of rotational velocities during or just after the main
sequence. This mechanism is also proposed as an explanation for the mass-loss
variations seen in the winds from Luminous Blue Variables (LBVs). These might
be relevant for the quasi-sinusoidal modulations seen in a number of recent
transitional supernovae (SNe), as well as for the double-throughed absorption
profile recently discovered in the Halpha line of SN 2005gj. Finally, we
discuss the role of metallicity via the Z-dependent character of their winds,
during both the initial and final (Wolf-Rayet) phases of evolution, with
implications for the angular momentum evolution of the progenitor stars of long
gamma-ray bursts (GRBs).


title: Hochschild Cohomology Theories in White Noise Analysis

abstract:
  We show that the continuous Hochschild cohomology and the differential
Hochschild cohomology of the Hida test algebra endowed with the normalized Wick
product are the same.


title: On the construction of A-infinity structures

abstract:
  We relate a construction of Kadeishvili's establishing an
A-infinity-structure on the homology of a differential graded algebra or more
generally of an A-infinity algebra with certain constructions of Chen and
Gugenheim. Thereafter we establish the links of these constructions with
subsequent developments.


title: On Pure and (approximate) Strong Equilibria of Facility Location Games

abstract:
  We study social cost losses in Facility Location games, where $n$ selfish
agents install facilities over a network and connect to them, so as to forward
their local demand (expressed by a non-negative weight per agent). Agents using
the same facility share fairly its installation cost, but every agent pays
individually a (weighted) connection cost to the chosen location. We study the
Price of Stability (PoS) of pure Nash equilibria and the Price of Anarchy of
strong equilibria (SPoA), that generalize pure equilibria by being resilient to
coalitional deviations. A special case of recently studied network design
games, Facility Location merits separate study as a classic model with numerous
applications and individual characteristics: our analysis for unweighted agents
on metric networks reveals constant upper and lower bounds for the PoS, while
an $O(\ln n)$ upper bound implied by previous work is tight for non-metric
networks. Strong equilibria do not always exist, even for the unweighted metric
case. We show that $e$-approximate strong equilibria exist ($e=2.718...$). The
SPoA is generally upper bounded by $O(\ln W)$ ($W$ is the sum of agents'
weights), which becomes tight $\Theta(\ln n)$ for unweighted agents. For the
unweighted metric case we prove a constant upper bound. We point out several
challenging open questions that arise.


title: Rotation in a Generalised Dirac's Universe

abstract:
  The extension of Dirac's LNH to cover cosmological and fine-structure
time-varying "constants", and the rotation of the Universe, is here analysed,
including a "derivation" of the angular speed of the present Universe, and of
the inflationary phase. Criticizable points on the present calculation, are
clarified.


title: Efficient, Differentially Private Point Estimators

abstract:
  Differential privacy is a recent notion of privacy for statistical databases
that provides rigorous, meaningful confidentiality guarantees, even in the
presence of an attacker with access to arbitrary side information.
  We show that for a large class of parametric probability models, one can
construct a differentially private estimator whose distribution converges to
that of the maximum likelihood estimator. In particular, it is efficient and
asymptotically unbiased. This result provides (further) compelling evidence
that rigorous notions of privacy in statistical databases can be consistent
with statistically valid inference.


title: Status of MICE

abstract:
  Muon ionization cooling is the only practical method for preparing
high-brilliance beams needed for a neutrino factory or muon collider. The muon
ionization cooling experiment (MICE) under development at the Rutherford
Appleton Laboratory comprises a dedicated beamline to generate a range of input
emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a
pure muon beam. A first measurement of emittance is performed in the upstream
magnetic spectrometer with a scintillating-fiber tracker. A cooling cell will
then follow, alternating energy loss in liquid hydrogen with RF acceleration. A
second spectrometer identical to the first and a particle identification system
will measure the outgoing emittance. Plans for measurements of emittance and
cooling are described.


title: Emittance Measurement in MICE

abstract:
  Muon ionization cooling provides the only practical solution to prepare
high-brilliance beams necessary for a neutrino factory or muon collider. The
Muon Ionization Cooling Experiment (MICE), under development at the Rutherford
Appleton Laboratory, is installing the first set of particle detectors ever
built to measure to 0.1% the emittance of a 200 MeV/c or so muon beam in and
out of a cooling cell, and thus measure the cooling cell's performance. Two
identical "emittometers" (a precise scintillating-fiber tracker in solenoidal
magnetic field and a 50 ps time-of-flight station) measure the six phase-space
coordinates of each muon. Another TOF plane and two Cherenkov counters assure
the purity of the incoming muon beam. A downstream electron/muon calorimeter
eliminates contamination from decay electrons.


title:
Hopping charge transport in disordered organic materials: where is the
  disorder?

abstract:
  Effect of energetic disorder on charge carrier transport in organic materials
has been reexamined. A reliable method for mobility calculation and subsequent
evaluation of relevant disorder parameters has been discussed. This method is
well suited for a direct calculation of the magnitude of dipolar disorder
$\sigma_\textrm{dip}$ in polar organic materials from the current transients.
Calculation of $\sigma_\textrm{dip}$ for several transport materials with
varying concentration of polar dopants gives concentration dependences that are
in reasonable agreement with theoretical predictions. A possible solution of
the puzzle concerning the disorder effect on the mobility temperature
dependence has been suggested.


title: Constraint-based, Single-point Approximate Kinetic Energy Functionals

abstract:
  We present a substantial extension of our constraint-based approach for
development of orbital-free (OF) kinetic-energy (KE) density functionals
intended for the calculation of quantum-mechanical forces in multi-scale
molecular dynamics simulations. Suitability for realistic system simulations
requires that the OF-KE functional yield accurate forces on the nuclei yet be
relatively simple. We therefore require that the functionals be based on DFT
constraints, local, dependent upon a small number of parameters fitted to a
training set of limited size, and applicable beyond the scope of the training
set. Our previous "modified conjoint" generalized-gradient-type functionals
were constrained to producing a positive-definite Pauli potential. Though
distinctly better than several published GGA-type functionals in that they gave
semi-quantitative agreement with Born-Oppenheimer forces from full Kohn-Sham
results, those modified conjoint functionals suffer from unphysical
singularities at the nuclei. Here we show how to remove such singularities by
introducing higher-order density derivatives. We give a simple illustration of
such a functional used for the dissociation energy as a function of bond length
for selected molecules.


title:
Spatial correlations in sheared isothermal liquids : From elastic
  particles to granular particles

abstract:
  Spatial correlations for sheared isothermal elastic liquids and granular
liquids are theoretically investigated. Using the generalized fluctuating
hydrodynamics, correlation functions for both the microscopic scale and the
macroscopic scale are obtained. The existence of the long-range correlation
functions obeying power laws has been confirmed. The validity of our
theoretical predictions have been verified from the molecular dynamics
simulation.


title:
Jump transformations and an embedding of ${\cal O}_{\infty}$ into ${\cal
  O}_{2}$

abstract:
  A measurable map $T$ on a measure space induces a representation $\Pi_{T}$ of
a Cuntz algebra ${\cal O}_{N}$ when $T$ satisfies a certain condition. For such
two maps $\tau$ and $\sigma$ and representations $\Pi_{\tau}$ and
$\Pi_{\sigma}$ associated with them, we show that $\Pi_{\tau}$ is the
restriction of $\Pi_{\sigma}$ when $\tau$ is a jump transformation of $\sigma$.
Especially, the Gauss map $\tau_1$ and the Farey map $\sigma_1$ induce
representations $\Pi_{\tau_1}$ of ${\cal O}_{\infty}$ and that $\Pi_{\sigma_1}$
of ${\cal O}_{2}$, respectively, and $\Pi_{\tau_1}=\Pi_{\sigma_1}|_{{\cal
O}_{\infty}}$ with respect to a certain embedding of ${\cal O}_{\infty}$ into
${\cal O}_{2}$.


title: Bounds on Lorentz and CPT Violation from the Earth-Ionosphere Cavity

abstract:
  Electromagnetic resonant cavities form the basis of many tests of Lorentz
invariance involving photons. The effects of some forms of Lorentz violation
scale with cavity size. We investigate possible signals of violations in the
naturally occurring resonances formed in the Earth-ionosphere cavity.
Comparison with observed resonances places the first terrestrial constraints on
coefficients associated with dimension-three Lorentz-violating operators at the
level of 10^{-20} GeV.


title:
A variational multiscale Newton-Schur approach for the incompressible
  Navier-Stokes equations

abstract:
  In the following paper, we present a consistent Newton-Schur solution
approach for variational multiscale formulations of the time-dependent
Navier-Stokes equations in three dimensions. The main contributions of this
work are a systematic study of the variational multiscale method for
three-dimensional problems, and an implementation of a consistent formulation
suitable for large problems with high nonlinearity, unstructured meshes, and
non-symmetric matrices. In addition to the quadratic convergence
characteristics of a Newton-Raphson based scheme, the Newton-Schur approach
increases computational efficiency and parallel scalability by implementing the
tangent stiffness matrix in Schur complement form. As a result, more
computations are performed at the element level. Using a variational multiscale
framework, we construct a two-level approach to stabilizing the incompressible
Navier-Stokes equations based on a coarse and fine-scale subproblem. We then
derive the Schur complement form of the consistent tangent matrix. We
demonstrate the performance of the method for a number of three-dimensional
problems for Reynolds number up to 1000 including steady and time-dependent
flows.


title:
Reinforced communication and social navigation generate groups in model
  networks

abstract:
  To investigate the role of information flow in group formation, we introduce
a model of communication and social navigation. We let agents gather
information in an idealized network society, and demonstrate that heterogeneous
groups can evolve without presuming that individuals have different interests.
In our scenario, individuals' access to global information is constrained by
local communication with the nearest neighbors on a dynamic network. The result
is reinforced interests among like-minded agents in modular networks; the flow
of information works as a glue that keeps individuals together. The model
explains group formation in terms of limited information access and highlights
global broadcasting of information as a way to counterbalance this
fragmentation. To illustrate how the information constraints imposed by the
communication structure affects future development of real-world systems, we
extrapolate dynamics from the topology of four social networks.