title: Sur les corrections de la g\'eom\'etrie thermodynamique des trous noirs

abstract:
  We study thermodynamic geometry of certain black holes and black branes with
and without generalized uncertainty principle or stringy $ \alpha^{\prime}
$-corrections to the entropy. From this perspective, we analyze Ruppenier
geometry of Reissner-Nordstr\"om black holes and show that it is well defined
and corresponds to a non-interacting statistical system. We investigate that
the Weinhold geometry of dilatonic black holes is regular everywhere and that
of large mass Reissner-Nordstr\"om black holes in the Poincar\'e patch of $
AdS_4 $ contains certain narrow range of thermodynamically unstable regions in
the statespace. We obtain that the generalized uncertainty principle corrected
Ruppenier geometry of Reissner-Nordstr\"om black holes correspond to a
non-interacting statistical system unlike the magnetically charged black holes.
We show that the stringy $ \alpha^{\prime} $-corrections do not introduce
singularity in the statespace geometry of non-supersymmetric extremal black
holes in $ D= 4 $. Interestingly, the degree of scalar curvature and that of
the determinant of this Ruppenier geometry can be written as an integer
multiple of the order of $ \alpha^{\prime} $-correction. We further show that
the statespace geometry of Gauss- Bonnet corrected supersymmetric extremal
black holes in $ D=4 $ as well as non-extremal $D_1D_5$ and $D_2D_6NS_5$ black
branes in $ D=10 $ is regular everywhere. Furthermore, the thermodynamic
geometry of four dimensional rotating Kerr-Newman extremal black holes in
Einstein-Maxwell theory is everywhere ill-defined and that of the Kaluza-Klein
black holes in Einstein-Maxwell theory or the one arrising from heterotic
string compactification is ill-defined only at the points of the ergo-branch.


title:
Local estimates and global continuities in Lebesgue spaces for bilinear
  operators

abstract:
  In this paper, we first prove some local estimates for bilinear operators
(closely related to the bilinear Hilbert transform and similar singular
operators) with truncated symbol. Such estimates, in accordance with the
Heisenberg uncertainty principle correspond to a description of
``off-diagonal'' decay. In addition they allow us to prove global continuities
in Lebesgue spaces for bilinear operators with spatial dependent symbol.


title: How much in the Universe can be explained by geometry?

abstract:
  The paper uses geometrical arguments to derive equations with relevance for
cosmology; 5-dimensional spacetime is assumed because it has been shown in
other works to provide a setting for significant unification of different areas
of physics. Monogenic functions, which zero the vector derivative are shown to
effectively model electrodynamics and relativistic dynamics if one allows for
space curvature. Applying monogenic functions to flat space, the Hubble
relation can be derived straightforwardly as a purely geometrical effect.
Consideration of space curvature induced by mass density allows the derivation
of flat rotation curves for galaxies without appealing for dark matter.
Similarly, a small overall mass density in the Universe is shown to provide a
possible explanation for recent supernovae observations, without the need for a
cosmological constant.


title:
The Stability of an Isotropic Cosmological Singularity in Higher-Order
  Gravity

abstract:
  We study the stability of the isotropic vacuum Friedmann universe in gravity
theories with higher-order curvature terms of the form $(R_{ab}R^{ab})^{n}$
added to the Einstein-Hilbert Lagrangian of general relativity on approach to
an initial cosmological singularity. Earlier, we had shown that, when $% n=1$,
a special isotropic vacuum solution exists which behaves like the
radiation-dominated Friedmann universe and is stable to anisotropic and small
inhomogeneous perturbations of scalar, vector and tensor type. This is
completely different to the situation that holds in general relativity, where
an isotropic initial cosmological singularity is unstable in vacuum and under a
wide range of non-vacuum conditions. We show that when $n\neq 1$, although a
special isotropic vacuum solution found by Clifton and Barrow always exists, it
is no longer stable when the initial singularity is approached. We find the
particular stability conditions under the influence of tensor, vector, and
scalar perturbations for general $n$ for both solution branches. On approach to
the initial singularity, the isotropic vacuum solution with scale factor
$a(t)=t^{P_{-}/3}$ is found to be stable to tensor perturbations for $0.5<n<
1.1309$ and stable to vector perturbations for $0.861425 < n \leq 1$, but is
unstable as $t \to 0$ otherwise. The solution with scale factor
$a(t)=t^{P_{+}/3}$ is not relevant to the case of an initial singularity for
$n>1$ and is unstable as $t \to 0$ for all $n$ for each type of perturbation.


title: Triplets of Quasars at high redshift I: Photometric data

abstract:
  We have conducted an optical and infrared imaging in the neighbourhoods of 4
triplets of quasars. R, z', J and Ks images were obtained with MOSAIC II and
ISPI at Cerro Tololo Interamerican Observatory. Accurate relative photometry
and astrometry were obtained from these images for subsequent use in deriving
photometric redshifts. We analyzed the homogeneity and depth of the photometric
catalog by comparing with results coming from the literature. The good
agreement shows that our magnitudes are reliable to study large scale structure
reaching limiting magnitudes of R = 24.5, z' = 22.5, J = 20.5 and Ks = 19.0.
With this catalog we can study the neighbourhoods of the triplets of quasars
searching for galaxy overdensities such as groups and galaxy clusters.


title:
A compactly supported formula for equivariant localization, and,
  simplicial complexes of Bialynicki-Birula decompositions

abstract:
  Let X be a projective scheme carrying a circle action S with isolated fixed
points. We associate a simplicial complex Delta(X,S) of "closure chains" using
a refinement of its Morse/Bialynicki-Birula decomposition. If this
decomposition is a stratification (e.g. when X is a flag manifold), then
Delta(X,S) is just the order complex of the poset of fixed points. For X a
toric variety, Delta(X,S) is a triangulation of the moment polytope. We compute
some other examples, including a Bott-Samelson manifold and the punctual
Hilbert scheme of 4 points in the plane.
  Summing over the facets of Delta(X,S), we obtain a positive formula for the
Duistermaat-Heckman measure on the moment polytope of X, defined for any torus
action extending S. We explain how, through brutal use of partial fractions,
this can be extended to an AB/BV-type formula for integrating general classes.
Throughout we work with equivariant Chow groups, and do not make any smoothness
requirements on X.


title: Evolution of Substructure in Galaxy Clusters as Observed in X-Rays

abstract:
  Clusters of galaxies are the largest gravitationally-bound objects in the
Universe, having diameters on order of Mpc. Our work asked whether their shapes
(morphologies) change over time as the Universe ages. We observed a sample of
165 galaxy clusters, at 0.1 < z < 1.3. A variety of measures were used to
quantify the shapes of galaxy clusters. Archive observations from the Chandra
X-Ray Observatory were used. Morphology evolution was probed at two different
distances from clusters' centers -- 300 kpc and 500 kpc -- for comparison. In
almost all cases, we were able to rule out that clusters retain their
morphology over the history of the Universe, which is in agreement with our
current picture of large-scale structure formation. In addition, we found that
ellipticities, as a means of quantifying morphologies, are of limited use in
studies such as this work.


title:
Long Time Tail of the Velocity Autocorrelation Function in a
  Two-Dimensional Moderately Dense Hard Disk Fluid

abstract:
  Alder and Wainwright discovered the slow power decay $\sim t^{-d/2}$
($d$:dimension) of the velocity autocorrelation function in moderately dense
hard sphere fluids using the event-driven molecular dynamics simulations. In
the two-dimensional case, the diffusion coefficient derived using the time
correlation expression in linear response theory shows logarithmic divergence,
which is called the ``2D long-time-tail problem''. We revisited this problem to
perform a large-scale, long-time simulation with one million hard disks using a
modern efficient algorithm and found that the decay of the long tail in
moderately dense fluids is slightly faster than the power decay ($\sim 1/t$).
We also compared our numerical data with the prediction of the self-consistent
mode-coupling theory in the long time limit ($\sim 1/(t\sqrt{\ln{t}})$).


title: Electronic texture of the thermoelectric oxide Na0.75CoO2

abstract:
  From 59Co and 23Na NMR, we demonstrate the impact of the Na+ vacancy ordering
on the cobalt electronic states in Na0.75CoO2: at long time scales, there is
neither a disproportionation into 75 % Co3+ and 25 % Co4+ states, nor a
mixed-valence metal with a uniform Co3.25+ state. Instead, the system adopts an
intermediate configuration in which 30 % of the lattice sites form an ordered
pattern of localized Co3+ states. Above 180 K, an anomalous mobility of
specific Na+ sites is found to coexist with this electronic texture, suggesting
that the formation of the latter may contribute to stabilizing the Na+
ordering. Control of the ion doping in these materials thus appears to be
crucial for fine-tuning of their thermoelectric properties.


title: Diversity of critical behavior within a universality class

abstract:
  We study spatial anisotropy effects on the bulk and finite-size critical
behavior of the O$(n)$ symmetric anisotropic $\phi^4$ lattice model with
periodic boundary conditions in a $d$-dimensional hypercubic geometry above, at
and below $T_c$. The absence of two-scale factor universality is discussed for
the bulk order-parameter correlation function, the bulk scattering intensity,
and for several universal bulk amplitude relations. For the confined system,
renormalization-group theory within the minimal subtraction scheme at fixed
dimension $d$ for $2<d<4$ is employed. For the case of cubic symmetry and for
$n=1$ our perturbation approach yields excellent agreement with the Monte Carlo
(MC) data for the finite-size amplitude of the free energy of the
three-dimensional Ising model at $T_c$ by Mon [Phys. Rev. Lett. {\bf 54}, 2671
(1985)]. Below $T_c$ a minimum of the scaling function of the excess free
energy is found. We predict a measurable dependence of this minimum on the
anisotropy parameters. The relative anisotropy effect on the free energy is
predicted to be significantly larger than that on the Binder cumulant. Our
theory agrees quantitatively with the non-monotonic dependence of the Binder
cumulant on the ferromagnetic next-nearest neighbor (NNN) coupling of the
two-dimensional Ising model found by MC simulations of Selke and Shchur [J.
Phys. {\bf A 38}, L739 (2005)]. Our theory also predicts a non-monotonic
dependence for small values of the {\it antiferromagnetic} NNN coupling and the
existence of a Lifschitz point at a larger value of this coupling. The
nonuniversal anisotropy effects in the finite-size scaling regime are predicted
to satisfy a kind of restricted universality. The tails of the large-$L$
behavior at $T \neq T_c$ violate both finite-size scaling and universality.


title:
A sampling inequality for fractional order Sobolev semi-norms using
  arbitrary order data

abstract:
  To improve convergence results obtained using a framework for unsymmetric
meshless methods due to Schaback (Preprint G\"ottingen 2006), we extend, in two
directions, the Sobolev bound due to Arcang\'eli et al. (Numer Math 107,
181-211, 2007), which itself extends two others due to Wendland and Rieger
(Numer Math 101, 643-662, 2005) and Madych (J. Approx Theory 142, 116-128,
2006). The first is to incorporate discrete samples of arbitrary order
derivatives into the bound, which are used to obtain higher order convergence
in higher order Sobolev norms. The second is to optimally bound fractional
order Sobolev semi-norms, which are used to obtain more optimal convergence
rates when solving problems requiring fractional order Sobolev spaces, notably
inhomogeneous boundary value problems.


title: Experimental Implementation of Projective Measurement in Bell Basis

abstract:
  A scheme for direct projection of a quantum state on Bell states is
described. The method is based on constructing an average Hamiltonian with Bell
eigenstates and then, projecting the state on these eigenstates. The projection
is performed by adding the results of a direct and time-reversed evolution.
Experimental demonstration is shown for pairs of dipolar-coupled nuclear spins.


title: Extensions of Lie-Rinehart algebras and cotangent bundle reduction

abstract:
  Let Q denote a smooth manifold acted upon smoothly by a Lie group G. The
G-action lifts to an action on the total space T of the cotangent bundle of Q
and hence on the standard symplectic Poisson algebra of smooth functions on T.
The Poisson algebra of G-invariant functions on T yields a Poisson structure on
the space T/G of G-orbits. We relate this Poisson algebra with extensions of
Lie-Rinehart algebras and derive an explicit formula for this Poisson structure
in terms of differentials. We then show, for the particular case where the
G-action on Q is principal, how an explicit description of the Poisson algebra
derived in the literature by an ad hoc construction is essentially a special
case of the formula for the corresponding extension of Lie-Rinehart algebras.
By means of various examples, we also show that this kind of description breaks
down when the G-action does not define a principal bundle.


title: Finding the Kraus decomposition from a master equation and vice versa

abstract:
  For any master equation which is local in time, whether Markovian,
non-Markovian, of Lindblad form or not, a general procedure is reviewed for
constructing the corresponding linear map from the initial state to the state
at time t, including its Kraus-type representations. Formally, this is
equivalent to solving the master equation. For an N-dimensional Hilbert space
it requires (i) solving a first order N^2 x N^2 matrix time evolution (to
obtain the completely positive map), and (ii) diagonalising a related N^2 x N^2
matrix (to obtain a Kraus-type representation). Conversely, for a given
time-dependent linear map, a necessary and sufficient condition is given for
the existence of a corresponding master equation, where the (not necessarily
unique) form of this equation is explicitly determined. It is shown that a
`best possible' master equation may always be defined, for approximating the
evolution in the case that no exact master equation exists. Examples involving
qubits are given.


title:
Inducing the mu and the B mu Term by the Radion and the 5d Chern-Simons
  Term

abstract:
  In 5-dimensional models with gauge-Higgs unification, the F-term vacuum
expectation value of the radion provides, in close analogy to the
Giudice-Masiero mechanism, a natural source for the mu and B mu term. Both the
leading order gauge theory lagrangian and the supersymmetric Chern-Simons term
contain couplings to the radion superfield which can be used for this purpose.
We analyse the basic features of this mechanism for mu term generation and
provide an explicit example, based on a variation of the SU(6) gauge-Higgs
unification model of Burdman and Nomura. This construction contains all the
relevant features used in our generic analysis. More generally, we expect our
mechanism to be relevant to many of the recently discussed orbifold GUT models
derived from heterotic string theory. This provides an interesting way of
testing high-scale physics via Higgs mass patterns accessible at the LHC.


title: On a formula for the spectral flow and its applications

abstract:
  We consider a continuous path of bounded symmetric Fredholm bilinear forms
with arbitrary endpoints on a real Hilbert space, and we prove a formula that
gives the spectral flow of the path in terms of the spectral flow of the
restriction to a finite codimensional closed subspace. We also discuss the case
of restrictions to a continuous path of finite codimensional closed subspaces.
As an application of the formula, we introduce the notion of spectral flow for
a periodic semi-Riemannian geodesic, and we compute its value in terms of the
Maslov index.


title: Eddington-Born-Infeld action for dark energy and dark matter

abstract:
  We argue that Einstein gravity coupled to a Born-Infeld theory provides an
attractive candidate to represent dark matter and dark energy. For cosmological
models, the Born-Infeld field has an equation of state which interpolates
between matter, w=0 (small times), and a cosmological constant w=-1 (large
times). On galactic scales, the Born-Infeld field predicts asymptotically flat
rotation curves.


title: Relationship between scattering matrix and spectrum of quantum graphs

abstract:
  We investigate the equivalence between spectral characteristics of the
Laplace operator on a metric graph, and the associated unitary scattering
operator. We prove that the statistics of level spacings, and moments of
observations in the eigenbases coincide in the limit that all bond lengths
approach a positive constant value.


title: Quantified Propositional Logspace Reasoning

abstract:
  In this paper, we develop a quantified propositional proof systems that
corresponds to logarithmic-space reasoning. We begin by defining a class
SigmaCNF(2) of quantified formulas that can be evaluated in log space. Then our
new proof system GL^* is defined as G_1^* with cuts restricted to SigmaCNF(2)
formulas and no cut formula that is not quantifier free contains a free
variable that does not appear in the final formula.
  To show that GL^* is strong enough to capture log space reasoning, we
translate theorems of VL into a family of tautologies that have polynomial-size
GL^* proofs. VL is a theory of bounded arithmetic that is known to correspond
to logarithmic-space reasoning. To do the translation, we find an appropriate
axiomatization of VL, and put VL proofs into a new normal form.
  To show that GL^* is not too strong, we prove the soundness of GL^* in such a
way that it can be formalized in VL. This is done by giving a logarithmic-space
algorithm that witnesses GL^* proofs.


title:
Enrichment of the dust-to-gas mass ratio in Bondi/Jeans accretion/cloud
  systems due to unequal changes in dust and gas incoming velocities

abstract:
  The ratio of the Bondi and Jeans lengths is used to develop a cloud-accretion
model that describes both an inner Bondi-type regime where gas pressure is
balanced by the gravity of a central star and an outer Jeans-type regime where
gas pressure is balanced by gas self-gravity. The gas density profile provided
by this model makes a smooth transition from a wind-type inner solution to a
Bonnor-Ebert type outer solution. It is shown that high-velocity dust impinging
on this cloud will tend to pile-up due to having a different velocity profile
than gas so that the dust-to-gas ratio is substantially enriched above the 1%
ISM level.


title: Note on Frobenius monoidal functors

abstract:
  It is well known that strong monoidal functors preserve duals. In this short
note we show that a slightly weaker version of functor, which we call
"Frobenius monoidal", is sufficient.


title: Flaxino dark matter and stau decay

abstract:
  If the spontaneous breaking of Peccei-Quinn symmetry comes from soft
supersymmetry breaking, the fermionic partners of the symmetry-breaking fields
have mass of order the gravitino mass, and are called flatinos. The lightest
flatino, called here the flaxino, is a CDM candidate if it is the lightest
supersymmetric particle. We here explore flaxino dark matter assuming that the
lightest ordinary supersymmetric particle is the stau, with gravity-mediated
supersymmetry breaking. The decay of the stau to the flaxino is fast enough not
to spoil the standard predictions of Big Bang Nucleosynthesis, and its track
and decay can be seen in future colliders.


title: A new gravitational wave background from the Big Bang

abstract:
  The reheating of the universe after hybrid inflation proceeds through the
nucleation and subsequent collision of large concentrations of energy density
in the form of bubble-like structures moving at relativistic speeds. This
generates a significant fraction of energy in the form of a stochastic
background of gravitational waves, whose time evolution is determined by the
successive stages of reheating: First, tachyonic preheating makes the amplitude
of gravity waves grow exponentially fast. Second, bubble collisions add a new
burst of gravitational radiation. Third, turbulent motions finally sets the end
of gravitational waves production. From then on, these waves propagate
unimpeded to us. We find that the fraction of energy density today in these
primordial gravitational waves could be significant for GUT scale models of
inflation, although well beyond the frequency range sensitivity of
gravitational wave observatories like LIGO, LISA or BBO. However, low-scale
models could still produce a detectable signal at frequencies accessible to BBO
or DECIGO. For comparison, we have also computed the analogous background from
some chaotic inflation models and obtained similar results to those of other
groups. The discovery of such a background would open a new observational
window into the very early universe, where the details of the process of
reheating could be explored. Thus, it could also serve as a new experimental
tool for testing the Inflationary Paradigm.


title:
New Regulators for Quantum Field Theories with Compactified Extra
  Dimensions. II: Ultraviolet Finiteness and Effective Field Theory
  Implementation

abstract:
  In a previous companion paper [arXiv:0712.3532], we proposed two new
regulators for quantum field theories in spacetimes with compactified extra
dimensions. Unlike most other regulators which have been used in the
extra-dimension literature, these regulators are specifically designed to
respect the original higher-dimensional Lorentz and gauge symmetries that exist
prior to compactification, and not merely the four-dimensional symmetries which
remain afterward. In this paper, we use these regulators in order to develop a
method for extracting ultraviolet-finite results from one-loop calculations.
This method also allows us to derive Wilsonian effective field theories for
Kaluza-Klein modes at different energy scales. Our method operates by ensuring
that divergent corrections to parameters describing the physics of the excited
Kaluza-Klein modes are absorbed into the corresponding parameters for zero
modes, thereby eliminating the need to introduce independent counterterms for
parameters characterizing different Kaluza-Klein modes. Our effective field
theories can therefore simplify calculations involving Kaluza-Klein modes, and
be compared directly to potential experimental results emerging from collider
data.


title: Entanglement entropy in d+1 SU(N) gauge theory

abstract:
  We consider the entanglement entropy for a sub-system in d+1 dimensional
SU(N) lattice gauge theory. The 1+1 gauge theory is treated exactly and shows
trivial behavior. Gauge theories in higher dimensions are treated within
Migdal-Kadanoff approximation. We consider the gauge theory in the confinement
phase. We demonstrate the existence of a non-analytical change from the short
distance to long distance form in the entanglement entropy in such systems
(d>2) reminiscent of a phase transition. The transition is manifested in
nontrivial change in the RG flow of the character expansion coefficients
defining the partition function.


title:
Thermodynamical properties of topological Born-Infeld-dilaton black
  holes

abstract:
  We examine the $(n+1)$-dimensional $(n\geq3)$ action in which gravity is
coupled to the Born-Infeld nonlinear electrodynamic and a dilaton field. We
construct a new $(n+1)$-dimensional analytic solution of this theory in the
presence of Liouville-type dilaton potentials. These solutions which describe
charged topological dilaton black holes with nonlinear electrodynamics, have
unusual asymptotics. They are neither asymptotically flat nor (anti)-de Sitter.
The event horizons of these black holes can be an $(n-1)$-dimensional positive,
zero or negative constant curvature hypersurface. We also analyze
thermodynamics and stability of these solutions and disclose the effect of the
dilaton and Born-Infeld fields on the thermal stability in the canonical
ensemble.


title: Geometric Properties of Assur Graphs

abstract:
  In our previous paper, we presented the combinatorial theory for minimal
isostatic pinned frameworks - Assur graphs - which arise in the analysis of
mechanical linkages. In this paper we further explore the geometric properties
of Assur graphs, with a focus on singular realizations which have static
self-stresses. We provide a new geometric characterization of Assur graphs,
based on special singular realizations. These singular positions are then
related to dead-end positions in which an associated mechanism with an inserted
driver will stop or jam.


title: Schubert patches degenerate to subword complexes

abstract:
  We study the intersections of general Schubert varieties X_w with permuted
big cells, and give an inductive degeneration of each such "Schubert patch" to
a Stanley-Reisner scheme. Similar results had been known for Schubert patches
in various types of Grassmannians. We maintain reducedness using the results of
[Knutson 2007] on automatically reduced degenerations, or through more standard
cohomology-vanishing arguments.
  The underlying simplicial complex of the Stanley-Reisner scheme is a subword
complex, as introduced for slightly different purposes in [Knutson-Miller
2004], and is homeomorphic to a ball. This gives a new proof of the
Andersen-Jantzen-Soergel/Billey and Graham/Willems formulae for restrictions of
equivariant Schubert classes to fixed points.


title: Quantum walks on Erdos-Renyi networks

abstract:
  We study the coherent exciton transport of continuous-time quantum walks
(CTQWs) on Erdos-Renyi networks. The Erdos-Renyi network of N nodes is
constructed by connecting every pair of nodes with probability $p$. We
numerically calculate the ensemble averaged transition probability of quantum
transport between two nodes of the networks. For finite networks, we find that
the limiting transition probability is reached very quickly. For infinite
networks whose spectral density follows the semicircle law, the efficiencies of
the classical and quantum-mechanical transport are compared on networks of
different average degree. In the long time limiting, we consider the
distribution of the ensemble averaged transition probabilities, and show that
there is a high probability to find the exciton at the initial node. Such high
return probability almost do not alter in a wide range of connection
probability p but increases rapidly when the network approaches to be fully
connected. For networks whose topology is not extremely connected, the return
probability is inversely proportional to the network size N. Furthermore, the
transport dynamics are compared with that on a random graph model in which the
degree of each node equals to the average degree of the Erdos-Renyi networks.


title: High Resolution Near-Infrared Spectroscopy of FUors and FUor-like stars

abstract:
  We present new high resolution (R=18,000) near-infrared spectroscopic
observations of a sample of classical FU Orionis stars (FUors) and other young
stars with FUor characteristics that are sources of Herbig-Haro flows. Spectra
are presented for the region 2.203 - 2.236 microns which is rich in absorption
lines sensitive to both effective temperatures and surface gravities of stars.
Both FUors and FUor-like stars show numerous broad and weak unidentified
spectral features in this region. Spectra of the 2.280 - 2.300 micron region
are also presented, with the 2.2935 micron v=2-0 CO absorption bandhead being
clearly the strongest feature seen in the spectra all FUors and Fuor-like
stars. A cross-correlation analysis shows that FUor and FUor-like spectra in
the 2.203 - 2.236 micron region are not consistent with late-type dwarfs,
giants, nor embedded protostars. The cross-correlations also show that the
observed FUor-like Herbig-Haro energy sources have spectra that are
substantively similar to those of FUors. Both object groups also have similar
near-infrared colors. The large line widths and double-peaked nature of the
spectra of the FUor-like stars are consistent with the established accretion
disk model for FUors, also consistent with their near-infrared colors. It
appears that young stars with FUor-like characteristics may be more common than
projected from the relatively few known classical FUors.


title:
Universal condition for the existence of interface modes in the whole
  momentum space with arbitrary materials

abstract:
  It is shown that, by theoretical and experimental results, a universal
zero-impedance condition exists for two kinds of localized interface modes in
the whole momentum space (both above and below the light line). It can be
applied at the interface between any two materials including photonic crystals,
single-negative (negative-permittivity or negative-permeability) materials, or
double-negative metamaterials. In addition, it presents an intuitive physical
concept, and also provides a feasible way to determine interface modes, which
will have predominance in various applications.


title: Entropy of Kerr-Newman black hole to all orders in the Planck length

abstract:
  Using the quantum statistical method, the difficulty of solving the wave
equation on the background of the black hole is avoided.We directly solve the
partition functions of Bose and Fermi field on the background of an
axisymmetric Kerr-Newman black hole using the new equation of state density
motivated by the generalized uncertainty principle in the quantum gravity. Then
near the black hole horizon, we calculate entropies of Bose and Fermi field
between the black hole horizon surface and the hypersurface with the same
inherent radiation temperature measured by an observer at an infinite distance.
In our results there are not cutoffs and little mass approximation introduced
in the conventional brick-wall method. The series expansion of the black hole
entropy is obtained. And this series is convergent. It provides a way for
studying the quantum statistical entropy of a black hole in a non-spherical
symmetric spacetime.


title: Strategic Alert Throttling for Intrusion Detection Systems

abstract:
  Network intrusion detection systems are themselves becoming targets of
attackers. Alert flood attacks may be used to conceal malicious activity by
hiding it among a deluge of false alerts sent by the attacker. Although these
types of attacks are very hard to stop completely, our aim is to present
techniques that improve alert throughput and capacity to such an extent that
the resources required to successfully mount the attack become prohibitive. The
key idea presented is to combine a token bucket filter with a realtime
correlation algorithm. The proposed algorithm throttles alert output from the
IDS when an attack is detected. The attack graph used in the correlation
algorithm is used to make sure that alerts crucial to forming strategies are
not discarded by throttling.


title:
Dependence of electronic and optical properties on a high-frequency
  field for carbon nanotubes

abstract:
  We study theoretically the electronic structure, transport and optical
properties for a zigzag single-wall carbon nanotube connected to two normal
conductor leads under the irradiation of an external electromagnetic field at
low temperatures, with particular emphasis on the features of high-frequency
response. Using the standard nonequilibrium Green's function techniques, we
examine the time-averaged density of states, the conductivity, the dielectric
function and the electron energy loss spectra for the system with photon
polarization parallel with the tunneling current direction, respectively.
Through some numerical examples, it is shown that the density of states is
strongly dependent on the incident electron energy, the strength and frequency
of the applied field. For higher electron energies in comparison with
lead-nanotube coupling energy, the system conductance decreases with increasing
the field strength and increases with increasing the field frequency
respectively, and shows some oscillation structures. Moreover, the optical
functions for the system have also a rich structure with the variation of field
frequency. It may demonstrate that this transport dependence on the external
field parameters can be used to give the energy spectra information of carbon
nanotubes and to detect the high-frequency microwave irradiation.


title:
A note on the Compound Burgers-Korteweg-de Vries Equation with
  higher-order nonlinearities and its traveling solitary waves

abstract:
  In this paper, we study a compound Korteweg-de Vries-Burgers equation with a
higher-order nonlinearity. A class of solitary wave solutions is obtained by
means of a series expansion.


title:
Plotting Calibration Curve Using Biosynthetic Specifically Labeled
  Compounds for Accurate Mass Isotopomer Analysis

abstract:
  This paper has been withdrawn by the author(s), due to the requirement of the
journal it currently submitted to


title:
Interior matter estimates of the X-ray pulsar in SAX J1808.4-3658 from
  mass-radius and rotation measurements

abstract:
  To constrain the equation of state of super-nuclear density matter and probe
the interior composition of the X-ray pulsar in SAX J1808.4-3658. In our
estimation, we consider both its persistent 2.49 ms X-ray pulsations discovered
by Wijnands and van der Klis from using the Rossi X-ray Timing Explorer, which
is interpreted to come from an accreting-powered millisecond X-ray pulsar in
the low mass X-ray binaries, and the corresponding mass-radius data analyzed of
the light curves of SAX J1808.4-3685 during its 1998 and 2005 outbursts by
Leahy et al. from assuming a hot spot model where the X-rays are originated
from the surface of the neutron star.


title: High Precision Photometry of Extreme KBO 2003 EL61

abstract:
  We present high precision, time-resolved visible and near infrared photometry
of the large (diameter ~ 2500 km) Kuiper belt object (136108) 2003 EL61. The
new data confirm rapid rotation at period P = 3.9155+/-0.0001 hr with a
peak-to-peak photometric range (Delta m_R) = 0.29+/-0.02 mag and further show
subtle but reproducible color variations with rotation. Rotational deformation
of 2003 EL61 alone would give rise to a symmetric lightcurve free of color
variations. The observed photometric deviations from the best-fit equilibrium
model show the existence of a large surface region with an albedo and color
different from the mean surface of 2003 EL61. We explore constraints on the
nature of this anomalous region set by the existing data.


title: Precise half-life measurement of the 26Si ground state

abstract:
  The beta-decay half-life of 26Si was measured with a relative precision of
1.4*10e3. The measurement yields a value of 2.2283(27) s which is in good
agreement with previous measurements but has a precision that is better by a
factor of 4. In the same experiment, we have also measured the non-analogue
branching ratios and could determine the super-allowed one with a precision
similar to the previously reported measurements. The experiment was done at the
Accelerator Laboratory of the University of Jyvaskyla where we used the IGISOL
technique with the JYFLTRAP facility to separate pure samples of 26Si.


title:
Non-Destructive Probing of Rabi Oscillations on the Cesium Clock
  Transition near the Standard Quantum Limit

abstract:
  We report on non-destructive observation of Rabi oscillations on the Cs clock
transition. The internal atomic state evolution of a dipole-trapped ensemble of
cold atoms is inferred from the phase shift of a probe laser beam as measured
using a Mach-Zehnder interferometer. We describe a single color as well as a
two-color probing scheme. Using the latter, measurements of the collective
pseudo-spin projection of atoms in a superposition of the clock states are
performed and the observed spin fluctuations are shown to be close to the
standard quantum limit.


title:
Reconstructing the geometric structure of a Riemannian symmetric space
  from its Satake diagram

abstract:
  The local geometry of a Riemannian symmetric space is described completely by
the Riemannian metric and the Riemannian curvature tensor of the space. In the
present article I describe how to compute these tensors for any Riemannian
symmetric space from the Satake diagram, in a way that is suited for the use
with computer algebra systems. As an example application, the totally geodesic
submanifolds of the Riemannian symmetric space SU(3)/SO(3) are classified.
  The submission also contains an example implementation of the algorithms and
formulas of the paper as a package for Maple 10, the technical documentation
for this implementation, and a worksheet carrying out the computations for the
space SU(3)/SO(3) used in the proof of Proposition 6.1 of the paper.


title:
Topologies and Laplacian spectra of a deterministic uniform recursive
  tree

abstract:
  The uniform recursive tree (URT) is one of the most important models and has
been successfully applied to many fields. Here we study exactly the topological
characteristics and spectral properties of the Laplacian matrix of a
deterministic uniform recursive tree, which is a deterministic version of URT.
Firstly, from the perspective of complex networks, we determine the main
structural characteristics of the deterministic tree. The obtained vigorous
results show that the network has an exponential degree distribution, small
average path length, power-law distribution of node betweenness, and positive
degree-degree correlations. Then we determine the complete Laplacian spectra
(eigenvalues) and their corresponding eigenvectors of the considered graph.
Interestingly, all the Laplacian eigenvalues are distinct.


title:
Scaling Laws and Techniques in Decentralized Processing of Interfered
  Gaussian Channels

abstract:
  The scaling laws of the achievable communication rates and the corresponding
upper bounds of distributed reception in the presence of an interfering signal
are investigated. The scheme includes one transmitter communicating to a remote
destination via two relays, which forward messages to the remote destination
through reliable links with finite capacities. The relays receive the
transmission along with some unknown interference. We focus on three common
settings for distributed reception, wherein the scaling laws of the capacity
(the pre-log as the power of the transmitter and the interference are taken to
infinity) are completely characterized. It is shown in most cases that in order
to overcome the interference, a definite amount of information about the
interference needs to be forwarded along with the desired message, to the
destination. It is exemplified in one scenario that the cut-set upper bound is
strictly loose. The results are derived using the cut-set along with a new
bounding technique, which relies on multi letter expressions. Furthermore,
lattices are found to be a useful communication technique in this setting, and
are used to characterize the scaling laws of achievable rates.


title: Solving Min-Max Problems with Applications to Games

abstract:
  We refine existing general network optimization techniques, give new
characterizations for the class of problems to which they can be applied, and
show that they can also be used to solve various two-player games in almost
linear time. Among these is a new variant of the network interdiction problem,
where the interdictor wants to destroy high-capacity paths from the source to
the destination using a vertex-wise limited budget of arc removals. We also
show that replacing the limit average in mean payoff games by the maximum
weight results in a class of games amenable to these techniques.


title:
Effective Temperature Dynamics in an Athermal Amorphous Plasticity
  Theory

abstract:
  Recent developments in the theory of amorphous plasticity point to the
central role played by the concept of an effective disorder temperature
$T_{eff}$. An athermal dynamics for $T_{eff}$ are proposed in the framework of
a deformation theory and discussed in light of the recent steady state
simulations by Haxton and Liu [Phys. Rev. Lett. {\bf 99}, 195701 (2007)]. The
structure of the resulting theory, its parameters and transient dynamics are
discussed and compared to available data.


title:
Spin dynamics of two-dimensional electrons with Rashba spin-orbit
  coupling and electron-electron interactions

abstract:
  We study the spin dynamics of two dimensional electron gases (2DEGs) with
Rashba spin-orbit coupling by taking account of electron-electron interactions.
The diffusion equations for charge and spin densities are derived by making use
of the path-integral approach and the quasiclassical Green's function.
Analyzing the effect of the interactions, we show that the spin-relaxation time
can be enhanced by the electron-electron interaction in the ballistic regime.


title: Causality, Modality and Explanation

abstract:
  We present a sequent calculus system for a modal reformulation of a system of
nonmonotonic logic due to McCain and Turner: we prove cut elimination for our
system. The proof system is in general infinitary: because we can prove cut
elimination, many applications need, in practice, only the application of
finitary rules. Consequently, nonmonotonic logic is, in many cases, much less
scary than it might seem to be a priori. We derive from this a critique of
Fodor's philosophical worries about the nonmonotonicity of human reasoning.


title: The algorithms of the implicit moment method for plasma simulation

abstract:
  We discuss the fundamentals of the implicit moment method for Particle In
Cell (PIC) simulation as presently implemented in the CELESTE3D code. We
present the method in its fully electromagnetic and fully kinetic version. The
application of the method is to problems with multiple temporal and spatial
scales, common in all space, astrophysical and laboratory plasmas.


title: Self-consistent models of triaxial galaxies in MOND gravity

abstract:
  The Bekenstein-Milgrom gravity theory with a modified Poisson equation is
tested here for the existence of triaxial equilibrium solutions. Using the
non-negative least square method, we show that self-consistent triaxial
galaxies exist for baryonic models with a mild density cusp $\rho \sim {\Sigma
\over r}$. Self-consistency is achieved for a wide range of central
concentrations, $\Sigma \sim 10-1000\mathrm{M_{\odot}pc^{-2}}$, representing
low-to-high surface brightness galaxies. Our results demonstrate for the first
time that the orbit superposition technique is fruitful for constructing galaxy
models beyond Newtonian gravity, and triaxial cuspy galaxies might exist
without the help of Cold dark Matter.


title:
Characteristic cycles of standard modules for the rational Cherednik
  algebra of type Z/lZ

abstract:
  We study the representation theory of the rational Cherednik algebra
$H_\kappa = H_\kappa({\mathbb Z}_l)$ for the cyclic group ${\mathbb Z}_l =
{\mathbb Z} / l {\mathbb Z}$ and its connection with the geometry of the quiver
variety $M_\theta(\delta)$ of type $A_{l-1}^{(1)}$.
  We consider a functor between the categories of $H_\kappa$-modules with
different parameters, called the shift functor, and give the condition when it
is an equivalence of categories.
  We also consider a functor from the category of $H_\kappa$-modules with good
filtration to the category of coherent sheaves on $M_\theta(\delta)$. We prove
that the image of the regular representation of $H_\kappa$ by this functor is
the tautological bundle on $M_\theta(\delta)$. As a corollary, we determine the
characteristic cycles of the standard modules. It gives an affirmative answer
to a conjecture given in [Gordon, arXiv:math/0703150v1] in the case of
${\mathbb Z}_l$.


title: Continuous biorthogonality of the elliptic hypergeometric function

abstract:
  We construct a family of continuous biorthogonal functions related to an
elliptic analogue of the Gauss hypergeometric function. The key tools used for
that are the elliptic beta integral and the integral Bailey chain introduced
earlier by the author. Relations to the Sklyanin algebra and elliptic analogues
of the Faddeev modular double are discussed in detail.


title: Plane Jacobian problem for rational polynomials

abstract:
  This paper has been withdrawn by the author due to a crucial error in the
last lines in the proof of Lemma 3.3.


title:
Characterizing the nature of embedded young stellar objects through
  silicate, ice and millimeter observations

abstract:
  (Abridged) Classification schemes for YSOs are based on evaluating the degree
of dissipation of the surrounding envelope, whose main effects are the
extinction of the optical radiation from the central YSO and re-emission in the
far-infrared. Since extinction is a property of column density along the line
of sight, the presence of a protoplanetary disk may lead to a misclassification
when the system is viewed edge-on.
  We performed radiative transfer calculations, using the axysimmetric 3D
radiative transfer codes RADMC and RADICAL, to show the effects of different
geometries on the main indicators of YSO evolutionary stage, like the slope of
the flux between 2 and 24mum, the bolometric temperature and the optical depth
of silicates and ices.
  We show that for systems viewed at intermediate angles the 'classical'
indicators of evolution accurately trace the envelope column density, and they
all agree with each other. On the other hand, edge-on system are misclassified
for inclinations larger than ~65deg. In particular, silicate emission, typical
of pre-main sequence stars with disks, turns into absorption when the disk
column density reaches 1e22cm-2, corresponding e.g. to a 5e-3 Msun flaring disk
viewed at 64deg. A similar effect is noticed in all the other classification
indicators studied alpha, Tbol, and the H2O and CO2 ices absorption strengths.
This misclassification has a big impact on the nature of the flat-spectrum
sources (alpha ~0), whose number can be explained by simple geometrical
arguments without invoking evolution. A reliable classification scheme using a
minimal number of observations is constituted by observations of the mm-flux
with both a single dish and an interferometer.


title: Dirac's hole theory and the Pauli principle: clearing up the confusion

abstract:
  In Dirac's hole theory (HT) the vacuum state is generally believed to be the
state of minimum energy due to the assumption that the Pauli Exclusion
Principle prevents the decay of positive energy electrons into occupied
negative energy states. However recently papers have appeared that claim to
show that there exist states with less energy than that of the vacuum[4][5][6].
Here we will consider a simple model of HT consisting of zero mass electrons in
1-1D space-time. It will be shown that for this model there are states with
less energy than the HT vacuum state and that the Pauli Principle is obeyed.
Therefore the conjecture that the Pauli Principle prevents the existence of
states with less energy than the vacuum state is not correct.


title: Divergence in lattices in semisimple Lie groups and graphs of groups

abstract:
  Divergence functions of a metric space estimate the length of a path
connecting two points $A$, $B$ at distance $\le n$ avoiding a large enough ball
around a third point $C$. We characterize groups with non-linear divergence
functions as groups having cut-points in their asymptotic cones. By
Olshanskii-Osin-Sapir, that property is weaker than the property of having
Morse (rank 1) quasi-geodesics. Using our characterization of Morse
quasi-geodesics, we give a new proof of the theorem of Farb-Kaimanovich-Masur
that states that mapping class groups cannot contain copies of irreducible
lattices in semi-simple Lie groups of higher ranks. It also gives a
generalization of the result of Birman-Lubotzky-McCarthy about solvable
subgroups of mapping class groups not covered by the Tits alternative of Ivanov
and McCarthy.
  We show that any group acting acylindrically on a simplicial tree or a
locally compact hyperbolic graph always has "many" periodic Morse
quasi-geodesics (i.e. Morse elements), so its divergence functions are never
linear. We also show that the same result holds in many cases when the
hyperbolic graph satisfies Bowditch's properties that are weaker than local
compactness. This gives a new proof of Behrstock's result that every
pseudo-Anosov element in a mapping class group is Morse.
  On the other hand, we conjecture that lattices in semi-simple Lie groups of
higher rank always have linear divergence. We prove it in the case when the
$\mathbb{Q}$-rank is 1 and when the lattice is $SL_n(\mathcal{O}_S)$ where
$n\ge 3$, $S$ is a finite set of valuations of a number field $K$ including all
infinite valuations, and $\mathcal{O}_S$ is the corresponding ring of
$S$-integers.


title: Modification from Noncommutative Inflation

abstract:
  We explore the noncommutative effect on single field inflation and compare
with WMAP five-year data. First, we calculate the noncommutative effect from
the potential and dynamical terms, and construct the general form of modified
power spectrum. Second, we consider the leading order modification of
slow-roll, DBI and K-inflation and unite the modification, which means the
modification is nearly model independent at this level. Finally, comparing with
the WMAP5 data, we find that the modified can be well realized as the origin of
the relative large spectral index and the quite small running.


title:
Spectral conservation laws for periodic nonlinear equations of the
  Melnikov type

abstract:
  We consider the nonlinear equations obtained from soliton equations by adding
self-consistent sources. We demonstrate by using as an example the
Kadomtsev-Petviashvili equation that such equations on periodic functions are
not isospectral. They deform the spectral curve but preserve the multipliers of
the Floquet functions. The latter property implies that the conservation laws,
for soliton equations, which may be described in terms of the Floquet
multipliers give rise to conservation laws for the corresponding equations with
self-consistent sources. Such a property was first observed by us for some
geometrical flow which appears in the conformal geometry of tori in three- and
four-dimensional Euclidean spaces (math/0611215).


title: Lie bialgebra structures on the $W$-algebra W(2,2)

abstract:
  Verma modules over the $W$-algebra W(2,2) were considered by Zhang and Dong,
while the Harish-Chandra modules and irreducible weight modules over the same
algebra were classified by Liu and Zhu etc. In the present paper we shall
investigate the Lie bialgebra structures on the referred algebra, which are
shown to be triangular coboundary.


title: From Laplacian Transport to Dirichlet-to-Neumann (Gibbs) Semigroups

abstract:
  The paper gives a short account of some basic properties of
\textit{Dirichlet-to-Neumann} operators $\Lambda_{\gamma,\partial\Omega}$
including the corresponding semigroups motivated by the Laplacian transport in
anisotropic media ($\gamma \neq I$) and by elliptic systems with dynamical
boundary conditions. For illustration of these notions and the properties we
use the explicitly constructed \textit{Lax semigroups}. We demonstrate that for
a general smooth bounded convex domain $\Omega \subset \mathbb{R}^d$ the
corresponding {Dirichlet-to-Neumann} semigroup $\left\{U(t):= e^{-t
\Lambda_{\gamma,\partial\Omega}}\right\}_{t\geq0}$ in the Hilbert space
$L^2(\partial \Omega)$ belongs to the \textit{trace-norm} von Neumann-Schatten
ideal for any $t>0$. This means that it is in fact an \textit{immediate Gibbs}
semigroup. Recently Emamirad and Laadnani have constructed a
\textit{Trotter-Kato-Chernoff} product-type approximating family
$\left\{(V_{\gamma, \partial\Omega}(t/n))^n \right\}_{n \geq 1}$
\textit{strongly} converging to the semigroup $U(t)$ for $n\to\infty$. We
conclude the paper by discussion of a conjecture about convergence of the
\textit{Emamirad-Laadnani approximantes} in the the {\textit{trace-norm}}
topology.


title: Goodness of fit test for small diffusions by discrete observations

abstract:
  We consider a nonparametric goodness of fit test problem for the drift
coefficient of one-dimensional small diffusions. Our test is based on discrete
observation of the processes, and the diffusion coefficient is a nuisance
function which is estimated in our testing procedure. We prove that the limit
distribution of our test is the supremum of the standard Brownian motion, and
thus our test is asymptotically distribution free. We also show that our test
is consistent under any fixed alternatives.


title:
Flavor Diagonal and Off-Diagonal Susceptibilities in a Quasiparticle
  Model of the Quark-Gluon Plasma

abstract:
  The Taylor coefficients of flavor diagonal and off-diagonal susceptibilities
as well as baryon number, isovector and electric charge susceptibilities are
considered within a phenomenological quasiparticle model of the quark-gluon
plasma and successfully compared with lattice QCD data for two degenerate quark
flavors. These susceptibility coefficients represent sensible probes of baryon
density effects in the equation of state. The baryon charge is carried, in our
model, by quark-quasiparticle excitations for hard momenta.


title: Gravitation: in search of the missing torsion

abstract:
  A linear Lorentz connection has always two fundamental derived
characteristics: curvature and torsion. The latter is assumed to vanish in
general relativity. Three gravitational models involving non-vanishing torsion
are examined: teleparallel gravity, Einstein-Cartan, and new general
relativity. Their dependability is critically examined. Although a final answer
can only be given by experience, it is argued that teleparallel gravity
provides the most consistent approach.


title:
Optimal Location of Two Laser-interferometric Detectors for
  Gravitational Wave Backgrounds at 100 MHz

abstract:
  Recently, observational searches for gravitational wave background (GWB) have
been developed and given constraints on the energy density of GWB in a broad
range of frequencies. These constraints have already resulted in the rejection
of some theoretical models of relatively large GWB spectra. However, at 100
MHz, there is no strict upper limit from direct observation, though an indirect
limit exists due to He4 abundance due to big-bang nucleosynthesis. In our
previous paper, we investigated the detector designs that can effectively
respond to GW at high frequencies, where the wavelength of GW is comparable to
the size of a detector, and found that the configuration, a so-called
synchronous-recycling interferometer is best at these sensitivity. In this
paper, we investigated the optimal location of two synchronous-recycling
interferometers and derived their cross-correlation sensitivity to GWB. We
found that the sensitivity is nearly optimized and hardly changed if two
coaligned detectors are located within a range 0.2 m, and that the sensitivity
achievable in an experiment is far below compared with the constraint
previously obtained in experiments.


title: e-Science perspectives in Venezuela

abstract:
  We describe the e-Science strategy in Venezuela, in particular initiatives by
the Centro Nacional de Calculo Cientifico Universidad de Los Andes (CECALCULA),
Merida, the Universidad de Los Andes (ULA), Merida, and the Instituto
Venezolano de Investigaciones Cientificas (IVIC), Caracas. We present the plans
for the Venezuelan Academic Grid and the current status of Grid ULA supported
by Internet2. We show different web-based scientific applications that are
being developed in quantum chemistry, atomic physics, structural damage
analysis, biomedicine and bioclimate within the framework of the
E-Infrastructure shared between Europe and Latin America (EELA)


title: The structure of time and inertial forces in Lagrangian mechanics

abstract:
  Classically time is kept fixed for infinitesimal variations in problems in
mechanics. Apparently, there appears to be no mathematical justification in the
literature for this standard procedure. This can be explained canonically by
unveiling the intrinsic mathematical structure of time in Lagrangian mechanics.
Moreover, this structure also offers a general method to deal with inertial
forces.


title:
Fluctuation theorem and large deviation function for a solvable model of
  a molecular motor

abstract:
  We study a discrete stochastic model of a molecular motor. This discrete
model can be viewed as a \emph{minimal} ratchet model. We extend our previous
work on this model, by further investigating the constraints imposed by the
Fluctuation Theorem on the operation of a molecular motor far from equilibrium.
In this work, we show the connections between different formulations of the
Fluctuation Theorem. One formulation concerns the generating function of the
currents while another one concerns the corresponding large deviation function,
which we have calculated exactly for this model. A third formulation of FT
concerns the ratio of the probability of making one forward step to the
probability of making one backward step. The predictions of this last
formulation of the Fluctuation Theorem adapted to our model are in very good
agreement with the data of Carter and Cross [Nature, {\bf 435}, 308 (2005)] on
single molecule measurements with kinesin. Finally, we show that all the
formulations of FT can be understood from the notion of entropy production.


title: Critical percolation of virtually free groups and other tree-like graphs

abstract:
  This article presents a method for finding the critical probability $p_c$ for
the Bernoulli bond percolation on graphs with the so-called tree-like
structure. Such a graph can be decomposed into a tree of pieces, each of which
has finitely many isomorphism classes. This class of graphs includes the Cayley
graphs of amalgamated products, HNN extensions or general groups acting on
trees. It also includes all transitive graphs with more than one end. The idea
of the method is to find a multi-type Galton--Watson branching process (with a
parameter $p$) which has finite expected population size if and only if the
expected percolation cluster size is finite. This provides sufficient
information about $p_c$. In particular, if the pairwise intersections of pieces
are finite, then $p_c$ is the smallest positive $p$ such that $\operatorname
{det}(M-1)=0$, where $M$ is the first-moment matrix of the branching process.
If the pieces of the tree-like structure are finite, then $p_c$ is an algebraic
number and we give an algorithm computing $p_c$ as a root of some algebraic
function. We show that any Cayley graph of a virtually free group (i.e., a
group acting on a tree with finite vertex stabilizers) with respect to any
finite generating set has a tree-like structure with finite pieces. In
particular, we show how to compute $p_c$ for the Cayley graph of a free group
with respect to any finite generating set.


title: Worldsheet Instantons and Torsion Curves

abstract:
  We study aspects of worldsheet instantons relevant to a heterotic standard
model. The non-simply connected Calabi-Yau threefold used admits Z_3 x Z_3
Wilson lines, and a more detailed investigation shows that the homology classes
of curves are H_2(X,Z)=Z^3+Z_3+Z_3. We compute the genus-0 prepotential, this
is the first explicit calculation of the Gromov-Witten invariants of homology
classes with torsion (finite subgroups). In particular, some curve classes
contain only a single instanton. This ensures that the Beasley-Witten
cancellation of instanton contributions cannot happen on this (non-toric)
Calabi-Yau threefold.


title: Spectrum of $\pi$-electrons in Graphene As a Macromolecule

abstract:
  We report the exact solution of spectral problem for a graphene sheet framed
by two armchair- and two zigzag-shaped boundaries. The solution is found for
the $\pi$ electron Hamiltonian and gives, in particular, a closed analytic
expression of edge-state energies in graphene. It is shown that the lower
symmetry of graphene, in comparison with $C_{6h}$ of 2D graphite, has a
profound effect on the graphene band structure. This and other obtained results
have far going implications for the understanding of graphene electronics. Some
of them are briefly discussed.


title:
From combinatorics to large deviations for the invariant measures of
  some multiclass particle systems

abstract:
  We prove large deviation principles (LDP) for the invariant measures of the
multiclass totally asymmetric simple exclusion process (TASEP) and the
multiclass Hammersely-Aldous-Diaconis (HAD) process on a torus. The proof is
based on a combinatorial representation of the measures in terms of a
\emph{collapsing procedure} introduced in \cite{A} for the 2-class TASEP and
then generalized in \cite{FM1}, \cite{FM2} and \cite{FM3} to the multiclass
TASEP and the multiclass HAD process. The rate functionals are written in terms
of variational problems that we solve in the cases of 2-class processes.


title: Multiparticle Quantum Cosmology

abstract:
  Fock space quantization of Hamiltonian constraints of General Relativity and
thermodynamics of quantum states for flat Friedmann-Lemaitre-Robertson-Walker
metrics is presented.


title:
Measuring the Dynamical State of the Internet: Large Scale Network
  Tomography via the ETOMIC Infrastructure

abstract:
  In this paper we show how to go beyond the study of the topological
properties of the Internet, by measuring its dynamical state using special
active probing techniques and the methods of network tomography. We demonstrate
this approach by measuring the key state parameters of Internet paths, the
characteristics of queueing delay, in a part of the European Internet. In the
paper we describe in detail the ETOMIC measurement platform that was used to
conduct the experiments, and the applied method of queueing delay tomography.
The main results of the paper are maps showing various spatial structure in the
characteristics of queueing delay corresponding to the resolved part of the
European Internet. These maps reveal that the average queueing delay of network
segments spans more than two orders of magnitude, and that the distribution of
this quantity is very well fitted by the log-normal distribution.


title: Critical Temperature and Energy Gap for the BCS Equation

abstract:
  We derive upper and lower bounds on the critical temperature $T_c$ and the
energy gap $\Xi$ (at zero temperature) for the BCS gap equation, describing
spin 1/2 fermions interacting via a local two-body interaction potential
$\lambda V(x)$. At weak coupling $\lambda \ll 1$ and under appropriate
assumptions on $V(x)$, our bounds show that $T_c \sim A \exp(-B/\lambda)$ and
$\Xi \sim C \exp(-B/\lambda)$ for some explicit coefficients $A$, $B$ and $C$
depending on the interaction $V(x)$ and the chemical potential $\mu$. The ratio
$A/C$ turns out to be a universal constant, independent of both $V(x)$ and
$\mu$. Our analysis is valid for any $\mu$; for small $\mu$, or low density,
our formulas reduce to well-known expressions involving the scattering length
of $V(x)$.


title:
The fluid motion physics: The interaction mechanics of a free liquid jet
  with a body and with the other free liquid jet

abstract:
  Solution of a problem on the interaction mechanics of a free liquid jet with
a flat plate, body and with other jet has been achieved by means of a
graphic-analytical method, developed by author of the given article. This
method has allowed physically adequately and visually to describe the flow
field near the streamlined surface and to give expressions for quantitative
evaluation of the jet pressure profile onto this surface. This method is
equally correct for both a flat jet and a jet with a round cross-section.
Analysis of the flow field has allowed to detect a jet component, induced by
the body fore part in the unrestricted fluid stream and determining the body
form drag. Besides that, it has been ascertained that a friction also induces
the jet component in the potential boundary layer. It has been introduced a new
notion of the stream total head vector, determining an origin of the possible
jet flow in the stream.


title:
Generalized Gravity I : Kinematical Setting and reformalizing Quantum
  Field Theory

abstract:
  The first part of this work deals with the development of a natural
differential calculus on non-commutative manifolds. The second part extends the
covariance and equivalence principle as well studies its kinematical
consequences such as the arising of gauge theory. Furthermore, a manifestly
causal and covariant formulation of quantum field theory is presented which
surpasses the usual Hamiltonian and path integral construction. A particular
representation of this theory on the kinematical structure developed in section
three is moreover given.


title: Distribution of twisted Kloosterman sums modulo prime powers

abstract:
  In this note we study Kloosterman sums twisted by a multiplicative characters
modulo a prime power. We show, by an elementary calculation, that these sums
become equidistributed on the real line with respect to a suitable measure.


title: Empirical analysis on a keyword-based semantic system

abstract:
  Keywords in scientific articles have found their significance in information
filtering and classification. In this article, we empirically investigated
statistical characteristics and evolutionary properties of keywords in a very
famous journal, namely Proceedings of the National Academy of Science of the
United States of America (PNAS), including frequency distribution, temporal
scaling behavior, and decay factor. The empirical results indicate that the
keyword frequency in PNAS approximately follows a Zipf's law with exponent
0.86. In addition, there is a power-low correlation between the cumulative
number of distinct keywords and the cumulative number of keyword occurrences.
Extensive empirical analysis on some other journals' data is also presented,
with decaying trends of most popular keywords being monitored. Interestingly,
top journals from various subjects share very similar decaying tendency, while
the journals of low impact factors exhibit completely different behavior. Those
empirical characters may shed some light on the in-depth understanding of
semantic evolutionary behaviors. In addition, the analysis of keyword-based
system is helpful for the design of corresponding recommender systems.


title:
Inter-areal coordination of columnar architectures during visual
  cortical development

abstract:
  The occurrence of a critical period of plasticity in the visual cortex has
long been established, yet its function in normal development is not fully
understood. Here we show that as the late phase of the critical period unfolds,
different areas of cat visual cortex develop in a coordinated manner.
Orientation columns in areas V1 and V2 become matched in size in regions that
are mutually connected. The same age trend is found for such regions in the
left and right brain hemisphere. Our results indicate that a function of
critical period plasticity is to progressively coordinate the functional
architectures of different cortical areas - even across hemispheres.


title:
Milliarcsecond N-Band Observations of the Nova RS Ophiuchi: First
  Science with the Keck Interferometer Nuller

abstract:
  We report observations of the nova RS Ophiuchi (RS Oph) using the Keck
Interferometer Nuller (KIN), approximately 3.8 days following the most recent
outburst that occurred on 2006 February 12. These observations represent the
first scientific results from the KIN, which operates in N-band from 8 to 12.5
microns in a nulling mode. By fitting the unique KIN data, we have obtained an
angular size of the mid-infrared continuum of 6.2, 4.0, or 5.4 mas for a disk
profile, gaussian profile (FWHM), and shell profile respectively. The data show
evidence of enhanced neutral atomic hydrogen emission and atomic metals
including silicon located in the inner spatial regime near the white dwarf (WD)
relative to the outer regime. There are also nebular emission lines and
evidence of hot silicate dust in the outer spatial region, centered at ! 17 AU
from the WD, that are not found in the inner regime. Our evidence suggests that
these features have been excited by the nova flash in the outer spatial regime
before the blast wave reached these regions. These identifications support a
model in which the dust appears to be present between outbursts and is not
created during the outburst event. We further discuss the present results in
terms of a unifying model of the system that includes an increase in density in
the plane of the orbit of the two stars created by a spiral shock wave caused
by the motion of the stars through the cool wind of the red giant star. These
data show the power and potential of the nulling technique which has been
developed for the detection of Earth-like planets around nearby stars for the
Terrestrial Planet Finder Mission and Darwin missions.


title:
Kondo screening cloud and the charge staircase in one-dimensional
  mesoscopic devices

abstract:
  We propose that the finite size of the Kondo screening cloud, xi_K, can be
probed by measuring the charge quantization in a one-dimensional system coupled
to a small quantum dot. When the chemical potential, mu in the system is varied
at zero temperature, one should observe charge steps whose locations are at
values of mu that are controlled by the Kondo effect when the system size L is
comparable to xi_K. We show that, if the standard Kondo model is used, the
ratio between the widths of the Coulomb blockade valleys with odd or even
number of electrons is a universal scaling function of xi_K/L. If we take into
account electron-electron interactions in a single-channel wire, this ratio
also depends on the parameters of the effective Luttinger model; in addition,
the scaling is weakly violated by a marginal bulk interaction. For the geometry
of a quantum dot embedded in a ring, we show that the dependence of the charge
steps on a magnetic flux through the ring is controlled by the size of the
Kondo screening cloud.


title: Probing Heliospheric Asymmetries with an MHD-kinetic Model

abstract:
  New solar wind data from the Voyager 1 and Voyager 2 spacecraft, together
with the SOHO SWAN measurements of the direction that neutral hydrogen enters
into the inner heliosheath and neutral helium measurements provided by multiple
observations are expected to provide more reliable constraints on the
ionization ratio of the local interstellar medium (LISM) and the direction and
magnitude of the interstellar magnetic field (ISMF). In this paper we use
currently the most sophisticated numerical model of the heliospheric interface,
which is based on an MHD treatment of the ion flow and kinetic modeling of
neutral particles, to analyze an ISMF-induced asymmetry of the heliosphere in
the presence of the interplanetary magnetic field and neutral particles. It is
shown that secondary hydrogen atoms modify the LISM properties leading to its
shock-free deceleration at the heliopause. We determine the deflection of
hydrogen atoms from their original trajectory in the unperturbed LISM and show
that it occurs not only in the plane defined by the ISMF and LISM velocity
vectors, but also, to a lesser extent, perpendicular to this plane. We also
consider the possibility of using 2-3 kHz radio emission data to further
constrain the ISMF direction.


title: Deeply Virtual Compton Scattering with CLAS12

abstract:
  An overview is given about the capabilities provided by the JLab 12 GeV
Upgrade to measure deeply virtual exclusive processes with high statistics and
covering a large kinematics range in the parameters that are needed to allow
reconstruction of a spatial image of the nucleon's quark structure. The
measurements planned with CLAS12 will cross section asymmetries with polarized
beams and with longitudinally and transversely polarized proton targets in the
constrained kinematics $x = \pm \xi$. In addition, unpolarized DVCS cross
sections, and doubly polarized beam target asymmetries will be measured as
well. In this talk only the beam and target asymmetries will be discussed.


title:
Two-Dimensional Lattice Boltzmann Model For Compressible Flows With High
  Mach Number

abstract:
  In this paper we present an improved lattice Boltzmann model for compressible
Navier-Stokes system with high Mach number. The model is composed of three
components: (i) the discrete-velocity-model by Watari and Tsutahara [Phys Rev E
\textbf{67},036306(2003)], (ii) a modified Lax-Wendroff finite difference
scheme where reasonable dissipation and dispersion are naturally included,
(iii) artificial viscosity. The improved model is convenient to compromise the
high accuracy and stability. The included dispersion term can effectively
reduce the numerical oscillation at discontinuity. The added artificial
viscosity helps the scheme to satisfy the von Neumann stability condition.
Shock tubes and shock reflections are used to validate the new scheme. In our
numerical tests the Mach numbers are successfully increased up to 20 or higher.
The flexibility of the new model makes it suitable for tracking shock waves
with high accuracy and for investigating nonlinear nonequilibrium complex
systems.


title: Magnetism as a mass term of the edge states in graphene

abstract:
  The magnetism by the edge states in graphene is investigated theoretically.
An instability of the pseudo-spin order of the edge states induces
ferrimagnetic order in the presence of the Coulomb interaction. Although the
next nearest-neighbor hopping can stabilize the pseudo-spin order, a strong
Coulomb interaction makes the pseudo-spin unpolarized and real spin polarized.
The magnetism of the edge states makes two peaks of the density of states in
the conduction and valence energy bands near the Fermi point. Using a
continuous model of the Weyl equation, we show that the edge-induced gauge
field and the spin dependent mass terms are keys to make the magnetism of the
edge states. A relationship between the magnetism of the edge states and the
parity anomaly is discussed.


title: Time-dependent Green's functions approach to nuclear reactions

abstract:
  Nonequilibrium Green's functions represent underutilized means of studying
the time evolution of quantum many-body systems. In view of a rising computer
power, an effort is underway to apply the Green's functions formalism to the
dynamics of central nuclear reactions. As the first step, mean-field evolution
for the density matrix for colliding slabs is studied in one dimension. The
strategy to extend the dynamics to correlations is described.


title:
Computational aspects and applications of a new transform for solving
  the complex exponentials approximation problem

abstract:
  Many real life problems can be reduced to the solution of a complex
exponentials approximation problem which is usually ill posed. Recently a new
transform for solving this problem, formulated as a specific moments problem in
the plane, has been proposed in a theoretical framework. In this work some
computational issues are addressed to make this new tool useful in practice. An
algorithm is developed and used to solve a Nuclear Magnetic Resonance
spectrometry problem, two time series interpolation and extrapolation problems
and a shape from moments problem.


title:
Timing and spectral properties of the accreting millisecond pulsar SWIFT
  J1756.9-2508

abstract:
  SWIFT J1756.9-2508 is one of the few accreting millisecond pulsars (AMPs)
discovered to date. We report here the results of our analysis of its aperiodic
X-ray variability, as measured with the Rossi X-ray Timing Explorer during the
2007 outburst of the source. We detect strong (~35%) flat-topped broadband
noise throughout the outburst with low characteristic frequencies (~0.1 Hz).
This makes SWIFT J1756.9-2508 similar to the rest of AMPs and to other low
luminosity accreting neutron stars when they are in their hard states, and
enables us to classify this AMP as an atoll source in the extreme island state.
We also find a hard tail in its energy spectrum extending up to 100 keV, fully
consistent with such source and state classification.


title: Sobolev of the Euler School

abstract:
  This is a short overview of the origins of distribution theory as well as the
life of Sergei Sobolev (1908--1989) and his contribution to the formation of
the modern outlook of mathematics.


title:
Gauge-invariant electromagnetic response of a chiral px+ipy
  superconductor

abstract:
  We present a gauge-invariant theory of the electromagnetic response of a
chiral px+ipy superconductor in the clean limit. Due to the spontaneously
broken time-reversal symmetry, the effective action of the system contains an
anomalous term not present in conventional superconductors. As a result, the
electromagnetic charge and current responses contain anomalous terms, which
depend explicitly on the chirality of the superconducting order parameter.
These terms lead to a number of unusual effects, such as coupling of the
transverse currents to the collective plasma oscillations and a possibility of
inducing the charge density by the magnetic field perpendicular to the
conducting planes. We calculate the antisymmetric part of the conductivity
tensor (the intrinsic Hall conductivity) and show that it depends on the wave
vector of the electromagnetic field. We also show that the Mermin-Muzikar
magnetization current and the Hall conductivity are strongly suppressed at high
frequencies. Finally, we discuss implications of the theory to the experiments
in Sr2RuO4.


title: Multigap superconductivity in sesquicarbides La$_2$C$_3$ and Y$_2$C$_3$

abstract:
  A complex structure of the superconducting order parameter in $Ln_2$C$_3$
($Ln$ = La, Y) is demonstrated by muon spin relaxation ($\mu$SR) measurements
in their mixed state. The muon depolarization rate [$\sigma_{\rm v}(T)$]
exhibits a characteristic temperature dependence that can be perfectly
described by a phenomenological double-gap model for nodeless
superconductivity. While the magnitude of two gaps is similar between
La$_2$C$_3$ and Y$_2$C$_3$, a significant difference in the interband coupling
between those two cases is clearly observed in the behavior of $\sigma_{\rm
v}(T)$.


title:
Eigenfrequency of nodeless elastic vibrations locked in the crust of
  quaking neutron star

abstract:
  The Newtonian solid-mechanical theory of non-compressional spheroidal and
torsional nodeless elastic vibrations in the homogenous crust model of a
quaking neutron star is developed and applied to the modal classification of
the quasi-periodic oscillations (QPOs) of X-ray luminosity in the aftermath of
giant flares in SGR 1806-20 and SGR 1900+14. Particular attention is given to
the low-frequency QPOs in the data for SGR 1806-20 whose physical origin has
been called into question. Our calculations suggest that unspecified QPOs are
due to nodeless dipole torsional and dipole spheroidal elastic shear
vibrations.


title: Young Massive Clusters

abstract:
  Over the past ten years, there has been a revolution in our understanding of
massive young stellar clusters in the Galaxy. Initially, there were no known
examples having masses $>10^4$, yet we now know that there are at least a half
dozen such clusters in the Galaxy. In all but one case, the masses have been
determined through infrared observations. Several had been identified as
clusters long ago, but their massive natures were only recently determined.
Presumably, we are just scratching the surface, and we might look forward to
having statistically significant samples of coeval massive stars at all
important stages of stellar evolution in the near future. I review the efforts
that have led to this dramatic turn of events and the growing sample of young
massive clusters in the Galaxy.


title: Lectures on Stability and Constant Scalar Curvature

abstract:
  An introduction is provided to some current research trends in stability in
geometric invariant theory and the problem of Kaehler metrics of constant
scalar curvature. Besides classical notions such as Chow-Mumford stability, the
emphasis is on several new stability conditions, such as K-stability,
Donaldson's infinite-dimensional GIT, and conditions on the closure of orbits
of almost-complex structures under the diffeomorphism group. Related analytic
methods are also discussed, including estimates for energy functionals,
Tian-Yau-Zelditch approximations, estimates for moment maps, complex
Monge-Ampere equations and pluripotential theory, and the Kaehler-Ricci flow


title: Continuous-time quantum walks on one-dimension regular networks

abstract:
  In this paper, we consider continuous-time quantum walks (CTQWs) on
one-dimension ring lattice of N nodes in which every node is connected to its
2m nearest neighbors (m on either side). In the framework of the Bloch function
ansatz, we calculate the spacetime transition probabilities between two nodes
of the lattice. We find that the transport of CTQWs between two different nodes
is faster than that of the classical continuous-time random walk (CTRWs). The
transport speed, which is defined by the ratio of the shortest path length and
propagating time, increases with the connectivity parameter m for both the
CTQWs and CTRWs. For fixed parameter m, the transport of CTRWs gets slow with
the increase of the shortest distance while the transport (speed) of CTQWs
turns out to be a constant value. In the long time limit, depending on the
network size N and connectivity parameter m, the limiting probability
distributions of CTQWs show various paterns. When the network size N is an even
number, the probability of being at the original node differs from that of
being at the opposite node, which also depends on the precise value of
parameter m.


title: Symmetric and Asymptotically Symmetric Permutations

abstract:
  We consider two related problems arising from a question of R. Graham on
quasirandom phenomena in permutation patterns. A ``pattern'' in a permutation
$\sigma$ is the order type of the restriction of $\sigma : [n] \to [n]$ to a
subset $S \subset [n]$. First, is it possible for the pattern counts in a
permutation to be exactly equal to their expected values under a uniform
distribution? Attempts to address this question lead naturally to an
interesting number theoretic problem: when does $k!$ divide $\binom{n}{k}$?
Second, if the tensor product of a permutation with large random permutations
is random-like in its pattern counts, what must the pattern counts of the
original permutation be? A recursive formula is proved which uses a certain
permutation ``contraction.''


title: An Equation for Charge Decay Valid in Both Conductors and Insulators

abstract:
  Gauss' law and the equation of continuity must be satisfied in all materials
be they solids, liquids or gases. Most materials are classified as simple
materials; i.e., their electrical properties are linear, isotropic and
homogeneous. Charge transport in these simple materials should be described by
a constitutive equation known as Ohm's law. When Ohm's law is combined with
Gauss' law and the equation of continuity, a differential equation for volume
charge density relaxation results. The usual solution to this equation shows
that charge decays exponentially with a relaxation time given by the material's
permittivity divided by its electrical conductivity. Experiments show that good
conductors follow this exponential decay but that poor conductors (insulators)
tend to follow a decay that initially is more hyperbolic than exponential. This
suggests that either Ohm's law is not valid for insulator materials or that a
deeper understanding of Ohm's law is needed to explain charge decay in these
less than good conductors. This paper examines the latter approach and shows
that, when all the free charges within a simple material are taken into
account, a new unipolar charge decay equation is derived which is valid for any
simple material: conductor, insulator or anywhere in between. For good
conductors the equation reduces to the standard exponential law of decay. For
very poor conductors it reduces to the Vellenga-Klinkenberg modified hyperbolic
law with the initial decay producing the characteristic Bustin hyperbolic law
of decay. Explicit definitions for a good conductor and a good insulator are
obtained and are used to define the range where explicit deviations from both
of these hyperbolic laws occur.


title: Interstellar Holography

abstract:
  The dynamic spectrum of a radio pulsar is an in-line digital hologram of the
ionised interstellar medium. It has previously been demonstrated that such
holograms permit image reconstruction, in the sense that one can determine an
approximation to the complex electric field values as a function of
Doppler-shift and delay, but to date the quality of the reconstructions has
been poor. Here we report a substantial improvement in the method which we have
achieved by simultaneous optimisation of the thousands of coefficients that
describe the electric field. For our test spectrum of PSR B0834+06 we find that
the model provides an accurate representation of the data over the full 63 dB
dynamic range of the observations: residual differences between model and data
are noise-like. The advent of interstellar holography enables detailed
quantitative investigation of the interstellar radio-wave propagation paths for
a given pulsar at each epoch of observation; we illustrate this using our test
data which show the scattering material to be structured and highly
anisotropic. The temporal response of the medium exhibits a scattering tail out
to beyond 100 microsec and a pulse arrival time measurement at this frequency
and this epoch of observation would be affected by a mean delay of 15 microsec
due to multipath propagation in the interstellar medium.


title:
Phase Diagram of Na$_x$CoO$_2$ Studied by Gutzwiller Density Functional
  Theory

abstract:
  The ground states of Na$_x$CoO$_2$ ($0.0<x<1.0$) is studied by the
LDA+Gutzwiller approach, where charge transfer and orbital fluctuations are all
self-consistently treated {\it ab-initio}. In contrast to previous studies,
which are parameter-dependent, we characterized the phase diagram as: (1)
Stoner magnetic metal for $x>0.6$ due to $a_{1g}$ van-Hove singularity near
band top; (2) correlated non-magnetic metal without $e_g^{\prime}$ pockets for
$0.3<x<0.6$; (3) $e_g^{\prime}$ pockets appear for $x<0.3$, and additional
magnetic instability involves. Experimental quasi-particle properties is well
explained, and the $a_{1g}$-$e_g^{\prime}$ anti-crossing is attributed to
spin-orbital coupling.


title:
Polarization analysis of gravitational-wave backgrounds from the
  correlation signals of ground-based interferometers: measuring a
  circular-polarization mode

abstract:
  The Stokes V parameter characterizes asymmetry of amplitudes between right-
and left-handed waves, and non-vanishing value of the V parameter yields a
circularly polarized signal. Cosmologically, V parameter may be a direct probe
for parity violation in the universe. In this paper, we theoretically
investigate a measurement of this parameter, particularly focusing on the
gravitational-wave backgrounds observed via ground-based interferometers. In
contrast to the traditional analysis that only considers the total amplitude
(or equivalently $\Omega_{GW}$), the signal analysis including a
circular-polarized mode has a rich structure due to the multi-dimensionality of
target parameters. We show that, by using the network of next-generation
detectors, separation between polarized and unpolarized modes can be performed
with small statistical loss induced by their correlation.


title: B_K with two flavors of dynamical overlap fermions

abstract:
  We present a two-flavor QCD calculation of $B_K$ on a $16^3 \times 32$
lattice at $a\sim 0.12$ fm (or equivalently $a^{-1}\sim$1.67 GeV). Both valence
and sea quarks are described by the overlap fermion formulation. The matching
factor is calculated non-perturbatively with the so-called RI/MOM scheme. We
find that the lattice data are well described by the next-to-leading order
(NLO) partially quenched chiral perturbation theory (PQChPT) up to around a
half of the strange quark mass ($m_s^{\rm phys}/2$). The data at quark masses
heavier than $m_s^{\rm phys}/2$ are fitted including a part of
next-to-next-to-leading order terms. We obtain $B_K^{\bar{\rm MS}}(2 {\rm
GeV})= 0.537(4)(40)$, where the first error is statistical and the second is an
estimate of systematic uncertainties from finite volume, fixing topology, the
matching factor, and the scale setting.


title:
Carbon-Enhanced Metal-Poor Stars. III. Main-Sequence Turn-Off Stars from
  the SDSS/SEGUE Sample

abstract:
  The chemical compositions of seven Carbon-Enhanced Metal-Poor (CEMP) turn-off
stars are determined from high-resolution spectroscopy. Five of them are
selected from the SDSS/SEGUE sample of metal-poor stars. The effective
temperatures of these objects are all higher than 6000 K, while their
metallicities, parametrized by [Fe/H], are all below -2. Six of our program
objects exhibit high abundance ratios of barium ([Ba/H]> +1), suggesting large
contributions of the products of former AGB companions via mass transfer across
binary systems. Combining our results with previous studies provides a total of
20 CEMP main-sequence turn-off stars for which the abundances of carbon and at
least some neutron-capture elements are determined. Inspection of the [C/H]
ratios for this sample of CEMP turn-off stars show that they are generally
higher than those of CEMP giants; their dispersion in this ratio is also
smaller. We take these results to indicate that the carbon-enhanced material
provided from the companion AGB star is preserved at the surface of turn-off
stars with no significant dilution. In contrast, a large dispersion in the
observed [Ba/H] is found for the sample of CEMP turn-off stars, suggesting that
the efficiency of the s-process in very metal-poor AGB stars may differ greatly
from star to star. Four of the six stars from the SDSS/SEGUE sample exhibit
kinematics that are associated with membership in the outer-halo population, a
remarkably high fraction.


title:
Magnetic and structural transitions in La$_{1-x}A_{1-x}$CoO$_{3}$ ($A$ =
  Ca, Sr, and Ba)

abstract:
  We report thermal-expansion, lattice-constant, and specific-heat data of the
series La_1-xA_xCoO_3 for 0<= x <= 0.30 with A = Ca, Sr, and Ba. For the
undoped compound LaCoO_3 the thermal-expansion coefficient alpha(T) exhibits a
pronounced maximum around T=50K caused by a temperature-driven spin-state
transition from a low-spin state of the Co^{3+$ ions at low towards a higher
spin state at higher temperatures. The partial substitution of the La^{3+} ions
by divalent Ca^{2+}, Sr^{2+}, or Ba^{2+} ions causes drastic changes in the
macroscopic properties of LaCoO3. The large maximum in alpha(T) is suppressed
and completely vanishes for x> 0.12. For A = Ca three different anomalies
develop in alpha(T) with further increasing x, which are visible in
specific-heat data as well. Together with temperature-dependent x-ray data we
identify several phase transitions as a function of the doping concentration x
and temperature. From these data we propose an extended phase diagram for
La_1-xCa_xCoO_3.


title: String non(anti)commutativity for Neveu-Schwarz boundary conditions

abstract:
  The appearance of non(anti)commutativity in superstring theory, satisfying
the Neveu-Schwarz boundary conditions is discussed in this paper. Both an open
free superstring and also one moving in a background antisymmetric tensor field
are analyzed to illustrate the point that string non(anti)commutativity is a
consequence of the nontrivial boundary conditions. The method used here is
quite different from several other approaches where boundary conditions were
treated as constraints. An interesting observation of this study is that, one
requires that the bosonic sector satisfies Dirichlet boundary conditions at one
end and Neumann at the other in the case of the bosonic variables $X^{\mu}$
being antiperiodic. The non(anti)commutative structures derived in this paper
also leads to the closure of the super constraint algebra which is essential
for the internal consistency of our analysis.


title:
Phylogenies without Branch Bounds: Contracting the Short, Pruning the
  Deep

abstract:
  We introduce a new phylogenetic reconstruction algorithm which, unlike most
previous rigorous inference techniques, does not rely on assumptions regarding
the branch lengths or the depth of the tree. The algorithm returns a forest
which is guaranteed to contain all edges that are: 1) sufficiently long and 2)
sufficiently close to the leaves. How much of the true tree is recovered
depends on the sequence length provided. The algorithm is distance-based and
runs in polynomial time.

categories: q-bio.PE cs.CE cs.DS math.PR math.ST stat.TH


title: GaMnAs-based hybrid multiferroic memory device

abstract:
  A rapidly developing field of spintronics is based on the premise that
substituting charge with spin as a carrier of information can lead to new
devices with lower power consumption, non-volatility and high operational
speed. Despite efficient magnetization detection, magnetization manipulation is
primarily performed by current-generated local magnetic fields and is very
inefficient. Here we report a novel non-volatile hybrid multiferroic memory
cell with electrostatic control of magnetization based on strain-coupled GaMnAs
ferromagnetic semiconductor and a piezoelectric material. We use the
crystalline anisotropy of GaMnAs to store information in the orientation of the
magnetization along one of the two easy axes, which is monitored via transverse
anisotropic magnetoresistance. The magnetization orientation is switched by
applying voltage to the piezoelectric material and tuning magnetic anisotropy
of GaMnAs via the resulting stress field.


title: An Adhesion Model for the Drag Force

abstract:
  The paper present a model for the drag force between a resistive medium and a
solid body using the hypothesis that the drag force is created by the adhesion
of some particles of the resistive medium on the solid body's surface. The
study focus on the mass evolution of the solid body.


title: p-Wave superfluid and phase separation in atomic Bose-Fermi mixture

abstract:
  We consider a system of repulsively interacting Bose-Fermi mixtures of spin
polarized uniform atomic gases at zero temperature. We examine possible
realization of p-wave superfluidity of fermions due to an effective attractive
interaction via density fluctuations of Bose-Einstein condensate within
mean-field approximation. We find the ground state of the system by direct
energy comparison of p-wave superfluid and phase-separated states, and suggest
an occurrence of the p-wave superfluid for a strong boson-fermion interaction
regime. We study some signatures in the p-wave superfluid phase, such as
anisotropic energy gap and quasi-particle energy in the axial state, that have
not been observed in spin unpolarized superfluid of atomic fermions. We also
show that a Cooper pair is a tightly bound state like a diatomic molecule in
the strong boson-fermion coupling regime and suggest an observable indication
of the p-wave superfluid in the real experiment.


title:
A statistical mechanical interpretation of algorithmic information
  theory

abstract:
  We develop a statistical mechanical interpretation of algorithmic information
theory by introducing the notion of thermodynamic quantities, such as free
energy, energy, statistical mechanical entropy, and specific heat, into
algorithmic information theory. We investigate the properties of these
quantities by means of program-size complexity from the point of view of
algorithmic randomness. It is then discovered that, in the interpretation, the
temperature plays a role as the compression rate of the values of all these
thermodynamic quantities, which include the temperature itself. Reflecting this
self-referential nature of the compression rate of the temperature, we obtain
fixed point theorems on compression rate.


title: Quasinormal Modes of Kerr Black Holes in Four and Higher Dimensions

abstract:
  We analytically calculate to leading order the asymptotic form of quasinormal
frequencies of Kerr black holes in four, five and seven dimensions. All the
relevant quantities can be explicitly expressed in terms of elliptical
integrals. In four dimensions, we confirm the results obtained by Keshest and
Hod by comparing the analytic results to the numerical ones.


title:
Neutrino masses and lepton flavor violation in the 3-3-1 model with
  right-handed neutrinos

abstract:
  We show that in the framework of the 3-3-1 model with right-handed neutrinos,
small neutrino masses and large lepton flavor violating processes such as \mu
\to 3e and \mu \to e\gamma can be obtained by just introducing an additional
Higgs sextet. In the limit of vanishing of the Yukawa interaction among Higgs
and lepton triplets (h^\nu = 0), the decay \mu \to 3e strongly depends on the
neutrino mass patterns, but the \mu \to e\gamma almost does not. The neutrino
masses are not constrained by such processes in the cases of h^\nu \neq 0.


title: Thermal Inflation and the Gravitational Wave Background

abstract:
  We consider the impact of thermal inflation -- a short, secondary period of
inflation that can arise in supersymmetric scenarios -- on the stochastic
gravitational wave background. We show that while the primordial inflationary
gravitational wave background is essentially unchanged at CMB scales, it is
massively diluted at solar system scales and would be unobservable by a BBO
style experiment. Conversely, bubble collisions at the end of thermal inflation
can generate a new stochastic background. We calculate the likely properties of
the bubbles created during this phase transition, and show that the expected
amplitude and frequency of this signal would fall within the BBO range.