title:
A generalization of Gabriel's Galois covering functors and derived
  equivalences

abstract:
  Let $G$ be a group acting on a category $\mathcal{C}$. We give a definition
for a functor $F\colon \mathcal{C} \to \mathcal{C}'$ to be a $G$-covering and
three constructions of the orbit category $\mathcal{C}/G$, which generalizes
the notion of a Galois covering of locally finite-dimensional categories with
group $G$ whose action on $\mathcal{C}$ is free and locally bonded defined by
Gabriel. Here $\mathcal{C}/G$ is defined for any category $\mathcal{C}$ and we
do not require that the action of $G$ is free or locally bounded. We show that
a $G$-covering is a universal "$G$-invariant" functor and is essentially given
by the canonical functor $\mathcal{C} \to \mathcal{C}/G$. By using this we
improve a covering technique for derived equivalence. Also we prove theorems
describing the relationships between smash product construction and the orbit
category construction by Cibils and Marcos (2006) without the assumption that
the $G$-action is free. The orbit category construction by a cyclic group
generated by an auto-equivalence modulo natural isomorphisms (e.g., the
construction of cluster categories) is justified by a notion of the "colimit
orbit category". In addition, we give a presentation of the orbit category of a
category with a monoid action by a quiver with relations, which enables us to
calculate many examples.


title:
Strangely dispersed minimal sets in the quasiperiodically forced Arnold
  map

abstract:
  We study quasiperiodically forced circle endomorphisms, homotopic to the
identity, and show that under suitable conditions these exhibit uncountably
many minimal sets with a complicated structure, to which we refer to as
`strangely dispersed'. Along the way, we generalise some well-known results
about circle endomorphisms to the uniquely ergodically forced case. Namely, all
rotation numbers in the rotation interval of a uniquely ergodically forced
circle endomorphism are realised on minimal sets, and if the rotation interval
has non-empty interior then the topological entropy is strictly positive. The
results apply in particular to the quasiperiodically forced Arnold circle map,
which serves as a paradigm example.


title:
Recent developments in photon-level operations on travelling light
  fields

abstract:
  Annihilating and creating a photon in a travelling light field are useful
building blocks for quantum-state engineering to generate a photonic state at
will. In this paper, we review the relevance of these operations to some of the
fundamental aspects of quantum physics and recent advances in this research.


title: Bosonic Fields in Causal Set Theory

abstract:
  In this paper we will define a Lagrangian for scalar and gauge fields on
causal sets, based on the selection of an Alexandrov set in which the
variations of appropriate expressions in terms of either the scalar field or
the gauge field holonomies around suitable loops take on the least value. For
these fields, we will find that the values of the variations of these
expressions define Lagrangians in covariant form.


title: Disk-outflow Connection and the Molecular Dusty Torus

abstract:
  Toroidal obscuration is a keystone of AGN unification. There is now direct
evidence for the torus emission in infrared, and possibly water masers. Here I
summarize the torus properties, its possible relation to the immediate
molecular environment of the AGN and present some speculations on how it might
evolve with the AGN luminosity.


title: Dose dependence of ferromagnetism in Co-implanted ZnO

abstract:
  We have studied the structural, magnetic and electronic properties of
Co-implanted ZnO (0001) films grown on Al2O3 (1120) substrates for different
implantation doses and over a wide temperature range. Strong room temperature
ferromagnetism is observed with magnetic parameters depending on the cobalt
implantation dose. A detailed analysis of the structural and magnetic
properties indicates that there are two magnetic phases in Co-implanted ZnO
films. One is a ferromagnetic phase due to the formation of long range
ferromagnetic ordering between implanted magnetic cobalt ions in the ZnO layer,
the second one is a superparamagnetic phase, which occurs due to the formation
of metallic cobalt clusters in the Al2O3 substrate. Using x-ray resonant
magnetic scattering, the element specific magnetization of cobalt, oxygen and
Zn was investigated. Magnetic dichroism was observed at the Co L2,3 edges as
well as at the O K edge. In addition, the anomalous Hall effect is also
observed, supporting the intrinsic nature of ferromagnetism in Co-implanted ZnO
films.


title: Chiral Negative-Index Metamaterials in Terahertz

abstract:
  Negative index metamaterials (NIMs) give rise to unusual and intriguing
properties and phenomena, which may lead to important applications such as
superlens, subwavelength cavity and slow light devices. However, the negative
refractive index in metamaterials normally requires a stringent condition of
simultaneously negative permittivity and negative permeability. A new class of
negative index metamaterials - chiral NIMs, have been recently proposed. In
contrast to the conventional NIMs, chiral NIMs do not require the above
condition, thus presenting a very robust route toward negative refraction. Here
we present the first experimental demonstration of a chiral metamaterial
exhibiting negative refractive index down to n=-5 at terahertz frequencies,
with only a single chiral resonance. The strong chirality present in the
structure lifts the degeneracy for the two circularly polarized waves and
relieves the double negativity requirement. Chiral NIM are predicted to possess
intriguing electromagnetic properties that go beyond the traditional NIMs, such
as opposite signs of refractive indices for the two circular polarizations and
negative reflection. The realization of terahertz chiral NIMs offers new
opportunities for investigations of their novel electromagnetic properties, as
well as important terahertz device applications.


title:
Simplified Renormalizable $T^{'}$ Model for Tribimaximal Mixing and
  Cabibbo Angle

abstract:
  In a simplified renormalizable model where the neutrinos have PMNS
(Pontecorvo-Maki-Nakagawa-Sakata) mixings tan$^{2} \theta_{12} = {1/2},
\theta_{13}=0, \theta_{23} = \pi/4$ and with flavor symmetry $T^{'}$ there is a
corresponding prediction where the quarks have CKM (Cabibbo-Kobayashi-Maskawa)
mixings tan$2 \Theta_{12} = \frac{\sqrt{2}}{3}, \Theta_{13}=0, \Theta_{23} =0$.


title: Enhanced Horizons

abstract:
  Half-supersymmetric geometries of N=2 five-dimensional gauged supergravity
have recently been fully classified using spinorial geometry techniques. We use
this classification to determine all possible regular half-supersymmetric
near-horizon geometries, assuming that all of the gauge-invariant spinor
bilinears are regular at the horizon. Four geometries are found, two of which
have been found previously in hep-th/0611351 and arXiv:0708.3695.


title: Eventually Expanding Maps

abstract:
  In this paper we show that the piecewise linear map f(x) = px for x in
[0,1/p], and sx-s/p for x in (1/p,1], p > 1, 0 < s < 1 which has an expanding,
onto branch and a contracting branch is eventually piecewise expanding and
exact.


title:
The quantum phase transition in the sub-ohmic spin-boson model: Quantum
  Monte-Carlo study with a continuous imaginary time cluster algorithm

abstract:
  A continuous time cluster algorithm for two-level systems coupled to a
dissipative bosonic bath is presented and applied to the sub-ohmic spin-Boson
model. When the power s of the spectral function J(w) \propto w^s is smaller
than 1/2, the critical exponents are found to be classical, mean-field like.
Potential sources for the discrepancy with recent renormalization group
predictions are traced back to the effect of a dangerously irrelevant variable.


title: Stability diagram for the forced Kuramoto model

abstract:
  We analyze the periodically forced Kuramoto model. This system consists of an
infinite population of phase oscillators with random intrinsic frequencies,
global sinusoidal coupling, and external sinusoidal forcing. It represents an
idealization of many phenomena in physics, chemistry and biology in which
mutual synchronization competes with forced synchronization. In other words,
the oscillators in the population try to synchronize with one another while
also trying to lock onto an external drive. Previous work on the forced
Kuramoto model uncovered two main types of attractors, called forced
entrainment and mutual entrainment, but the details of the bifurcations between
them were unclear. Here we present a complete bifurcation analysis of the model
for a special case in which the infinite-dimensional dynamics collapse to a
two-dimensional system. Exact results are obtained for the locations of Hopf,
saddle-node, and Takens-Bogdanov bifurcations. The resulting stability diagram
bears a striking resemblance to that for the weakly nonlinear forced van der
Pol oscillator.


title: Incompressible surfaces, hyperbolic volume, Heegaard genus and homology

abstract:
  We show that if M is a complete, finite-volume, hyperbolic 3-manifold having
exactly one cusp, and if H_1(M;Z_2) has dimension at least 6, then M has volume
greater than 5.06. We also show that if M is a closed, orientable hyperbolic
3-manifold such that H_1(M;Z_2) has dimension at least 4, and if the image of
the cup product map in H^2(M;Z_2) has dimension at most 1, then M has volume
greater than 3.08. The proofs of these geometric results involve new
topological results relating the Heegaard genus of a closed Haken manifold M to
the Euler characteristic of the kishkes (i.e guts) of the complement of an
incompressible surface in M.


title: On an Auxiliary Function for Log-Density Estimation

abstract:
  In this note we provide explicit expressions and expansions for a special
function which appears in nonparametric estimation of log-densities. This
function returns the integral of a log-linear function on a simplex of
arbitrary dimension. In particular it is used in the R-package "LogCondDEAD" by
Cule et al. (2007).


title: The Colombeau Quaternion Algebra

abstract:
  We introduce the Colombeau Quaternio Algebra and study its algebraic
structure. We also study the dense ideal, dense in the algebraic sense, of the
algebra of Colombeau generalized numbers and use this show the existence of a
maximal ting of quotions which is Von Neumann regular. Recall that it is
already known that then algebra of COlombeau generalized numbers is not Von
Neumann regular. We also use the study of the dense ideals to give a criteria
for a generalized holomorphic function to satisfy the identity theorem.
  Aragona-Fernadez-Juriaans showed that a generalized holomorphic function has
a power series. This is one of the ingredients use to prove the identity
theorem.


title:
Anatomy and Phenomenology of the Lepton Flavor Universality in SUSY
  Theories

abstract:
  High precision electroweak tests, such as deviations from the Standard Model
expectations of the Lepton Flavor Universality breaking in K->lnu (with l= e or
mu), represent a powerful tool to test the Standard Model and, hence, to
constrain or obtain indirect hints of New Physics beyond it. We explore such a
possibility within Supersymmetric theories. Interestingly enough, a process
that in itself does not need lepton flavor violation to occur, i.e. the
violation of mu-e non-universality in K_l2, proves to be quite effective in
constraining not only relevant regions of SUSY models where lepton flavor is
conserved, but even those where specific lepton flavor violating contributions
arise. Indeed, a comparison with analogous bounds coming from tau lepton flavor
violating decays shows the relevance of the measurement of R_K to probe Lepton
Flavor Violation in SUSY. We outline the role and the interplay of the direct
New Physics searches at the LHC with the indirect searches performed by LFU
tests.


title: Analytical Solutions of Open String Field Theory

abstract:
  In this work we review Schnabl's construction of the tachyon vacuum solution
to bosonic covariant open string field theory and the results that followed.
  We survey the state of the art of string field theory research preceding this
construction focusing on Sen's conjectures and the results obtained using level
truncation methods.
  The tachyon vacuum solution can be described in various ways. We describe its
geometric representation using wedge states, its formal algebraic
representation as a pure-gauge solution and its oscillator representation. We
also describe the analytical proofs of some of Sen's conjectures for this
solution.
  The tools used in the context of the vacuum solution can be adapted to the
construction of other solutions, namely various marginal deformations. We
present some of the approaches used in the construction of these solutions.
  The generalization of these ideas to open superstring field theory is
explained in detail. We start from the exposition of the problems one faces in
the construction of superstring field theory. We then present the cubic and the
non-polynomial versions of superstring field theory and discuss a proposal
suggesting their classical equivalence. Finally, the bosonic solutions are
generalized to this case. In particular, we focus on the (somewhat surprising)
generalization of the tachyon solution to the case of a theory with no
tachyons.


title: Four-dimensional wall-crossing via three-dimensional field theory

abstract:
  We give a physical explanation of the Kontsevich-Soibelman wall-crossing
formula for the BPS spectrum in Seiberg-Witten theories. In the process we give
an exact description of the BPS instanton corrections to the hyperkahler metric
of the moduli space of the theory on R^3 x S^1. The wall-crossing formula
reduces to the statement that this metric is continuous. Our construction of
the metric uses a four-dimensional analogue of the two-dimensional tt*
equations.


title: On the dark nature of exciton Bose-Einstein condensate

abstract:
  We show that for the very same reason that excitons are bright, i.e. coupled
to photons, they have a higher energy than dark excitons, even for electrons
spatially separated from holes, such as in a double quantum well. Indeed, the
same channel which produces the finite electron-hole effective overlap
responsible for the absorption and emission of photon allows for Coulomb
interband exchange processes, which are nothing but a sequence of virtual
recombination and creation of one electron-hole pair. Consequently, this
additional repulsive electron-hole Coulomb exchange interaction exists for
bright excitons, but not for dark excitons. If we now remember that dark
excitons with spins $\pm 2$ are formed in a natural way through carrier
exchange between two opposite spin bright excitons, we are led to predict that
in a double quantum well sample with one trap -- a configuration appropriate to
get high density -- exciton Bose-Einstein condensation should appear when
cooling down the sample as a dark spot made of $(\pm 2)$ excitons at the center
of the trap.


title: Classical Hamiltonian Dynamics and Lie Group Algebras

abstract:
  The classical Hamilton equations of motion yield a structure sufficiently
general to handle an almost arbitrary set of ordinary differential equations.
Employing elementary algebraic methods, it is possible within the Hamiltonian
structure to describe many physical systems exhibiting Lie group symmetries.
Elementary examples include magnetic moment precession and the mechanical
orbits of color charged particles in classical non-abelian chromodynamics.


title: On a conjecture of Laugesen and Morpurgo

abstract:
  A well known conjecture of R. Laugesen and C. Morpurgo asserts that the
diagonal element of the Neumann heat kernel of the unit ball in
$\mathbb{R}^{n}$ ($n\geq1$) is a radially increasing function. In this paper,
we use probabilistic arguments to settle this conjecture, and, as an
application, we derive a new proof of the Hot Spots conjecture of J. Rauch in
the case of the unit disk.


title: The GBG-Rank and t-Cores I. Counting and 4-Cores

abstract:
  Let r_j(\pi,s) denote the number of cells, colored j, in the s-residue
diagram of partition \pi. The GBG-rank of \pi mod s is defined as
r_0+r_1*w_s+r_2*w_s^2+...+r_(s-1)*w_s^(s-1), where w_s=exp(2*\Pi*I/s). We will
prove that for (s,t)=1, v(s,t) <= binomial(s+t,s)/(s+t), where v(s,t) denotes a
number of distinct values that GBG-rank mod s of t-core may assume. The above
inequality becomes an equality when s is prime or when s is composite and
t<=2p_s, where p_s is a smallest prime divisor of s. We will show that the
generating functions for 4-cores with the prescribed values of GBG-rank mod 3
are all eta-products.


title: On the dynamics of thin shells of counter rotating particles

abstract:
  In this paper we study the dynamics of self gravitating spherically symmetric
thin shells of counter rotating particles. We consider all possible velocity
distributions for the particles, and show that the equations of motion by
themselves do not constrain this distribution. We therefore consider the
dynamical stability of the resulting configurations under several possible
processes. This include the stability of static configurations as a whole,
where we find a lower bound for the compactness of the shells. We analyze also
the stability of the single particle orbits, and find conditions for "single
particle evaporation". Finally, in the case of a shell with particles whose
angular momenta are restricted to two values, we consider the conditions for
stability under splitting into two separate shells. This analysis leads to the
conclusion that under certain conditions, that are given explicitly, an
evolving shell may split into one or more separate shells. We provide explicit
examples to illustrate this phenomenon. We also include a derivation of the
thick to thin shell limit for an Einstein shell that shows that the limiting
distribution of angular momenta is unique, covering continuously a finite range
of values.


title:
Long-term cycles in the history of life: Periodic biodiversity in the
  Paleobiology Database

abstract:
  Time series analysis of fossil biodiversity of marine invertebrates in the
Paleobiology Database (PBDB) shows a significant periodicity at approximately
63 My, in agreement with previous analyses based on the Sepkoski database. I
discuss how this result did not appear in a previous analysis of the PBDB. The
existence of the 63 My periodicity, despite very different treatment of
systematic error in both PBDB and Sepkoski databases strongly argues for
consideration of its reality in the fossil record. Cross-spectral analysis of
the two datasets finds that a 62 My periodicity coincides in phase by 1.6 My,
equivalent to better than the errors in either measurement. Consequently, the
two data sets not only contain the same strong periodicity, but its peaks and
valleys closely correspond in time. Two other spectral peaks appear in the PBDB
analysis, but appear to be artifacts associated with detrending and with the
increased interval length. Sampling-standardization procedures implemented by
the PBDB collaboration suggest that the signal is not an artifact of sampling
bias. Further work should focus on finding the cause of the 62 My periodicity.

categories: q-bio.PE astro-ph physics.bio-ph physics.data-an physics.geo-ph q-bio.QM stat.AP


title:
Cosmic-Ray Nuclei, Antiprotons and Gamma-rays in the Galaxy: a New
  Diffusion Model

abstract:
  We model the transport of cosmic ray nuclei in the Galaxy by means of a new
numerical code. Differently from previous numerical models we account for a
generic spatial distribution of the diffusion coefficient. We found that in the
case of radially uniform diffusion, the main secondary/primary ratios (B/C, N/O
and sub-Fe/Fe) and the modulated antiproton spectrum match consistently the
available observations. Convection and re-acceleration do not seem to be
required in the energy range we consider: $1 < E < 10^3$ GeV/nucleon. We
generalize these results accounting for radial dependence of the diffusion
coefficient, which is assumed to trace that of the cosmic ray sources. While
this does not affect the prediction of secondary/primary ratios, the simulated
longitude profile of the diffuse $\gamma$-ray emission is significantly
different from the uniform case and may agree with EGRET measurements without
invoking ad hoc assumptions on the galactic gas density distribution.


title:
Maxwell strata in sub-Riemannian problem on the group of motions of a
  plane

abstract:
  The left-invariant sub-Riemannian problem on the group of motions of a plane
is considered. Sub-Riemannian geodesics are parametrized by Jacobi's functions.
Discrete symmetries of the problem generated by reflections of pendulum are
described. The corresponding Maxwell points are characterized, on this basis an
upper bound on the cut time is obtained.


title: Hiding Quantum States in a Superposition

abstract:
  A method to hide certain quantum states in a superposition will be proposed.
Such method can be used to increase the security of a communication channel.
States represent an encrypted message will disappear during data exchange. This
makes the message 100% safe under direct measurement by an eavesdropper. No
entanglement sharing is required among the communicating parties.


title: Manin's conjecture for a cubic surface with D_5 singularity

abstract:
  The Manin conjecture is established for a split singular cubic surface in
P^3, with singularity type D_5.


title: Morse theory of the moment map for representations of quivers

abstract:
  The results of this paper concern the Morse theory of the norm-square of the
moment map on the space of representations of a quiver. We show that the
gradient flow of this function converges, and that the Morse stratification
induced by the gradient flow co-incides with the Harder-Narasimhan
stratification from algebraic geometry. Moreover, the limit of the gradient
flow is isomorphic to the graded object of the
Harder-Narasimhan-Jordan-H\"older filtration associated to the initial
conditions for the flow. With a view towards applications to Nakajima quiver
varieties we construct explicit local co-ordinates around the Morse strata and
(under a technical hypothesis on the stability parameter) describe the negative
normal space to the critical sets. Finally, we observe that the usual Kirwan
surjectivity theorems in rational cohomology and integral K-theory carry over
to this non-compact setting, and that these theorems generalize to certain
equivariant contexts.


title: Conformal actions of nilpotent groups on pseudo-Riemannian manifolds

abstract:
  We study conformal actions of connected nilpotent Lie groups on compact
pseudo-Riemannian manifolds. We prove that if a type-(p,q) compact manifold M
supports a conformal action of a connected nilpotent group H, then the degree
of nilpotence of H is at most 2p+1, assuming p <= q; further, if this maximal
degree is attained, then M is conformally equivalent to the universal
type-(p,q), compact, conformally flat space, up to finite covers. The proofs
make use of the canonical Cartan geometry associated to a pseudo-Riemannian
conformal structure.


title: Finite representations of continuum environments

abstract:
  Understanding dissipative and decohering processes is fundamental to the
study of quantum systems. An accurate and generic method for investigating
these processes is to simulate both the system and environment, which, however,
is computationally very demanding. We develop a novel approach to constructing
finite representations of the environment based on the influence of different
frequency scales on the system's dynamics. As an illustration, we analyze a
solvable model of an optical mode decaying into a reservoir. The influence of
the environment modes is constant for small frequencies, but drops off rapidly
for large frequencies, allowing for a very sparse representation at high
frequencies that gives a significant computational speedup in simulating the
environment. This approach provides a general framework for simulating open
quantum systems.


title: The cluster lens ACO 1703: redshift contrast and the inner profile

abstract:
  ACO 1703 is a cluster recently found to have a variety of strongly lensed
objects: there is a quintuply-imaged system at z=0.888 and several other lensed
objects from z=2.2 to 3.0 (the cluster itself is at z=0.28). It is not
difficult to model the lens, as previous work has already done. However, lens
models are generically non-unique. We generate ensembles of models to explore
the non-uniqueness. When the full range of source redshifts is included, all
models are close to \rho \propto r^{-1} out to 200 kpc. But if the quint is
omitted, both shallower and steeper models (e.g., \rho \propto r^{-2}) are
possible. The reason is that the redshift contrast between the quint and the
other sources gives a good measurement of the enclosed mass at two different
radii, thus providing a good estimate of the mass profile in between. This
result supports universal profiles and explains why single-model approaches can
give conflicting results. The mass map itself is elongated in the NW-SE
direction, like the galaxy distribution. An overdensity in both mass and light
is also apparent to the SE, which suggests meso-structure.


title: Stochastic Quantization for Complex Actions

abstract:
  We use the stochastic quantization method to study systems with complex
valued path integral weights. We assume a Langevin equation with a memory
kernel and Einstein's relations with colored noise. The equilibrium solution of
this non-Markovian Langevin equation is analyzed. We show that for a large
class of elliptic non-Hermitian operators acting on scalar functions on
Euclidean space, which define different models in quantum field theory,
converges to an equilibrium state in the asymptotic limit of the Markov
parameter. Moreover, as we expected, we obtain the Schwinger functions of the
theory.


title:
Mod-Gaussian convergence: new limit theorems in probability and number
  theory

abstract:
  We introduce a new type of convergence in probability theory, which we call
``mod-Gaussian convergence''. It is directly inspired by theorems and
conjectures, in random matrix theory and number theory, concerning moments of
values of characteristic polynomials or zeta functions. We study this type of
convergence in detail in the framework of infinitely divisible distributions,
and exhibit some unconditional occurrences in number theory, in particular for
families of $L$-functions over function fields in the Katz-Sarnak framework. A
similar phenomenon of ``mod-Poisson convergence'' turns out to also appear in
the classical Erd\H{o}s-K\'ac Theorem.


title:
Multivariable Bessel polynomials related to the hyperbolic Sutherland
  model with external Morse potential

abstract:
  A multivariable generalisation of the Bessel polynomials is introduced and
studied. In particular, we deduce their series expansion in Jack polynomials, a
limit transition from multivariable Jacobi polynomials, a sequence of
algebraically independent eigenoperators, Pieri type recurrence relations, and
certain orthogonality properties. We also show that these multivariable Bessel
polynomials provide a (finite) set of eigenfunctions of the hyperbolic
Sutherland model with external Morse potential.


title: Entanglement and ground states of gapped Hamiltonians

abstract:
  We begin by deriving bounds for the entanglement of a spin with an (adjacent
and non-adjacent) interval of spins in an arbitrary pure Finitely Correlated
States (FCS). The bounds we derive become exact in the case where one considers
the entanglement of a single spin with a half-infinite chain to the right of
it. Our result permits a more efficient calculation, numerically and in some
cases even analytically, of the entanglement in arbitrary finitely correlated
quantum spin chains. We continue the study of entanglement in the setting of
ground states of Hamiltonians with a spectral gap. In particular, for $V$ a
finite subset of $Z^d$, we let $H_V$ denote a Hamiltonian on $V$ with finite
range, finite strength interactions and a unique ground state with a
non-vanishing spectral gap. For a density matrix $\rho_A$ that describes the
finite-volume restriction to a region $A$ of the unique ground state, we
provide a detailed version of a proof by M. Hastings, that the entropy of
$\rho_A$ is bounded by a uniform constant $C$. Moreover, we provide a detailed
generalization of the 1-dimensional construction of Hastings' approximation to
the ground state in dimensions 2 and higher. Finally, we turn our attention to
the study of a conjecture central to Quantum Information Theory, the
multiplicativity of the maximal output Schatten $p$-norm of quantum channels,
for $p > 1$. In particular, we study the output 2-norm for a special class of
quantum channels, the depolarized Werner-Holevo channels, and show that
multiplicativity holds for a product of two identical channels in this class.


title:
The effect of pressure and spin on the isotopic composition of ferrous
  iron dissolved in periclase and silicate perovskite

abstract:
  We perform density functional calculations of the equilibrium 57Fe/54Fe
ratios for ferrous iron dissolved in periclase and MgSiO3 perovskite at the
pressures and temperatures of the Earth's mantle. Pressure increases the
partitioning of 57Fe into both phases by a factor of three from the Earth's
surface to the core-mantle boundary. In ferropericlase, a large contribution to
this increase comes from the electronic transition from high-spin to low-spin
iron. Our calculations demonstrate that pressure-induced fractionation can play
a major role in determining planetary iron-isotope composition.


title:
Comparison of low amplitude oscillatory shear in experimental and
  computational studies of model foams

abstract:
  A fundamental difference between fluids and solids is their response to
applied shear. Solids possess static shear moduli, while fluids do not. Complex
fluids such as foams display an intermediate response to shear with nontrivial
frequency-dependent shear moduli. In this manuscript, we conduct coordinated
experiments and numerical simulations of model foams subjected to
boundary-driven oscillatory, planar shear. Our studies are performed on bubble
rafts (experiments) and the bubble model (simulations) in 2D. We focus on the
low-amplitude flow regime in which T1 bubble rearrangement events do not occur,
yet the system transitions from solid- to liquid-like behavior as the driving
frequency is increased. In both simulations and experiments, we observe two
distinct flow regimes. At low frequencies $\omega$, the velocity profile of the
bubbles increases linearly with distance from the stationary wall, and there is
a nonzero total phase shift between the moving boundary and interior bubbles.
In this frequency regime, the total phase shift scales as a power-law $\Delta
\sim \omega^n$ with $n \approx 3$. In contrast, for frequencies above a
crossover frequency $\omega > \omega_{p}$, the total phase shift $\Delta$
scales linearly with the driving frequency. At even higher frequencies above a
characteristic frequency $\omega_{nl} > \omega_{p}$, the velocity profile
changes from linear to nonlinear. We fully characterize this transition from
solid- to liquid-like flow behavior in both the simulations and experiments,
and find qualitative and quantitative agreement for the characteristic
frequencies.


title: Dynamically Induced Zeeman Effect in Massless QED

abstract:
  It is shown that in non-perturbative massless QED an anomalous magnetic
moment is dynamically induced by an applied magnetic field. The induced
magnetic moment produces a Zeeman splitting for electrons in Landau levels
higher than $l=0$. The expressions for the non-perturbative Lande g-factor and
Bohr magneton are obtained. Possible applications of this effect are outlined.


title: Generalizing the Croke-Kleiner Construction

abstract:
  It is well known that every word hyperbolic group has a well-defined visual
boundary. An example of C. Croke and B. Kleiner shows that the same cannot be
said for CAT(0) groups. All boundaries of a CAT(0) group are, however, shape
equivalent, as observed by M. Bestvina and R. Geoghegan. Bestvina has asked if
they also satisfy the stronger condition of being cell-like equivalent. This
article describes a construction which will produce CAT(0) groups with multiple
boundaries. These groups have very complicated boundaries in high dimensions.
It is our hope that their study may provide insight into Bestvina's question.


title:
Les groupes de triangles $(2,p,q)$ sont d\'etermine\'es par leur spectre
  des longueurs

abstract:
  We describe the length spectra of triangle groups $(2,p,q)$ before showing
that the length spectra characterizes the isometry class of such a group.


title:
Heavy Quark Potential at Finite Temperature Using the Holographic
  Correspondence

abstract:
  We revisit the calculation of a heavy quark potential in N =4 supersymmetric
Yang-Mills theory at finite temperature using the AdS/CFT correspondence. As is
widely known, the potential calculated in the pioneering works of Rey et al.
and Brandhuber et al. is zero for separation distances r between the quark and
the anti-quark above a certain critical separation, at which the potential has
a kink. We point out that by analytically continuing the string configurations
into the complex plane, and using a slightly different renormalization
subtraction, one obtains a smooth non-zero (negative definite) potential
without a kink. The obtained potential also has a non-zero imaginary
(absorptive) part for separations r > r_c = 0.870/\pi T . At large separations
r the real part of the potential does not exhibit the exponential Debye falloff
expected from perturbation theory and instead falls off as a power law,
proportional to 1/r^4 for r > r_0 = 2.702 / \pi T.


title: Diffeomorphism invariance in spherically symmetric loop quantum gravity

abstract:
  We study the issue of the recovery of diffeomorphism invariance in the
recently introduced loop quantum gravity treatment of the exterior
Schwarzschild space-time. Although the loop quantization agrees with the
quantization in terms of metric variables in identifying the physical Hilbert
space, we show that diffeomorphism invariance in space-time is recovered with
certain limitations due to the use of holonomic variables in the loop treatment
of the model. This resembles behaviors that are expected in the full theory.


title: Origin and evolution of the genetic code: The universal enigma

abstract:
  The genetic code is nearly universal, and the arrangement of the codons in
the standard codon table is highly non-random. The three main concepts on
origin and evolution of the code are the stereochemical theory; the coevolution
theory; and the error minimization theory. These theories are not mutually
exclusive and are also compatible with the frozen accident hypothesis.
Mathematical analysis of the structure and possible evolutionary trajectories
of the code shows that it is highly robust to translational error but there is
a huge number of more robust codes, so that the standard code potentially could
evolve from a random code via a short sequence of codon series reassignments.
Thus, much of the evolution that led to the standard code can be interpreted as
a combination of frozen accident with selection for translational error
minimization although contributions from coevolution of the code with metabolic
pathways and/or weak affinities between amino acids and nucleotide triplets
cannot be ruled out. However, such scenarios for the code evolution are based
on formal schemes whose relevance to the actual primordial evolution is
uncertain, so much caution in interpretation is necessary. A real understanding
of the code's origin and evolution is likely to be attainable only in
conjunction with a credible scenario for the evolution of the coding principle
itself and the translation system.


title: TRIS II: search for CMB spectral distortions at 0.60, 0.82 and 2.5 GHz

abstract:
  With the TRIS experiment we have performed absolute measurements of the sky
brightness in a sky circle at $\delta = +42^{\circ}$ at the frequencies $\nu =$
0.60, 0.82 and 2.5 GHz. In this paper we discuss the techniques used to
separate the different contributions to the sky emission and give an evaluation
of the absolute temperature of the Cosmic Microwave Background. For the
black-body temperature of the CMB we get: $T_{cmb}^{th}=(2.837 \pm 0.129 \pm
0.066)K$ at $\nu=0.60$ GHz; $T_{cmb}^{th}=(2.803 \pm 0.051 ^{+0.430}
_{-0.300})K$ at $\nu=0.82$ GHz; $T_{cmb}^{th}=(2.516 \pm 0.139 \pm 0.284)K$ at
$\nu=2.5$ GHz. The first error bar is statistic (1$\sigma$) while the second
one is systematic. These results represent a significant improvement with
respect to the previous measurements. We have also set new limits to the
free-free distortions, $ -6.3 \times 10^{-6} < Y_{ff} < 12.6 \times 10^{-6}$,
and slightly improved the Bose-Einstein upper limit, $|\mu| < 6 \times
10^{-5}$, both at 95% confidence level.


title: 2D to 3D transition in soap films demonstrated by microrheology

abstract:
  We follow the diffusive motion of colloidal particles of diameter $d$ in soap
films of varying thickness $h$ with fluorescence microscopy. Diffusion
constants are obtained both from one- and two-particle microrheological
measurements of particle motion in these films. These diffusion constants are
related to the surface viscosity of the interfaces comprising the soap films,
by means of the Trapeznikov approximation [A. A. Trapeznikov, \emph{PICSA}
(1957)] and Saffman's equation for diffusion in a 2D fluid. Unphysical values
of the surface viscosity are found for thick soap films ($h/d > 7$), indicating
a transition from 2D to 3D behavior.


title: Efficient precision quantization in AdS/CFT

abstract:
  Understanding finite-size effects is one of the key open questions in solving
planar AdS/CFT. In this paper we discuss these effects in the AdS_5xS^5 string
theory at one-loop in the world-sheet coupling. First we provide a very
general, efficient way to compute the fluctuation frequencies, which allows to
determine the energy shift for very general multi-cut solutions. Then we apply
this to two-cut solutions, in particular the giant magnon and determine the
finite-size corrections at subleading order. The latter are then compared to
the finite-size corrections from Luscher-Klassen-Melzer formulas and found to
be in perfect agreement.


title:
Counterexamples to the maximal p-norm multiplicativity conjecture for
  all p > 1

abstract:
  For all p > 1, we demonstrate the existence of quantum channels with
non-multiplicative maximal output p-norms. Equivalently, for all p >1, the
minimum output Renyi entropy of order p of a quantum channel is not additive.
The violations found are large; in all cases, the minimum output Renyi entropy
of order p for a product channel need not be significantly greater than the
minimum output entropy of its individual factors. Since p=1 corresponds to the
von Neumann entropy, these counterexamples demonstrate that if the additivity
conjecture of quantum information theory is true, it cannot be proved as a
consequence of any channel-independent guarantee of maximal p-norm
multiplicativity. We also show that a class of channels previously studied in
the context of approximate encryption lead to counterexamples for all p > 2.


title: Superfluid Heat Conduction and the Cooling of Magnetized Neutron Stars

abstract:
  We report on a new mechanism for heat conduction in the neutron star crust.
We find that collective modes of superfluid neutron matter, called superfluid
phonons (sPhs), can influence heat conduction in magnetized neutron stars. They
can dominate the heat conduction transverse to magnetic field when the magnetic
field $B \gsim 10^{13}$ G. At density $\rho \simeq 10^{12}-10^{14} $ g/cm$^3$
the conductivity due to sPhs is significantly larger than that due to lattice
phonons and is comparable to electron conductivity when temperature $\simeq
10^8$ K. This new mode of heat conduction can limit the surface anisotropy in
highly magnetized neutron stars. Cooling curves of magnetized neutron stars
with and without superfluid heat conduction could show observationally
discernible differences.


title: Prime regular Hopf Algebras of GK-dimension One

abstract:
  This paper constitutes the first part of a program to classify all affine
prime regular Hopf algebras $H$ of Gelfand-Kirillov dimension one over an
algebraically closed field of characteristic zero. We prove a number of
properties of such an algebra, list some classes of examples, and then prove
that - when the PI-degree of $H$ is prime - our list contains all such
algebras.


title:
Restricted Wiedemann-Franz law and vanishing thermoelectric power in
  one-dimensional conductors

abstract:
  In one-dimensional (1D) conductors with linear E-k dispersion (Dirac systems)
intrabranch thermalization is favored by elastic electron-electron interaction
in contrast to electron systems with a nonlinear (parabolic) dispersion. We
show that under external electric fields or thermal gradients the carrier
populations of different branches, treated as Fermi gases, have different
temperatures as a consequence of self-consistent carrier-heat transport.
Specifically, in the presence of elastic phonon scattering, the Wiedemann-Franz
law is restricted to each branch with its specific temperature and is
characterized by twice the Lorenz number. In addition thermoelectric power
vanishes due to electron-hole symmetry, which is validated by experiment.


title: Dynamics of drying in 3D porous media

abstract:
  The drying dynamics in three dimensional porous media are studied with
confocal microscopy. We observe abrupt air invasions in size from single
particle to hundreds of particles. We show that these result from the strong
flow from menisci in large pores to menisci in small pores during drying. This
flow causes air invasions to start in large menisci and subsequently spread
throughout the entire system. We measure the size and structure of the air
invasions and show that they are in accord with invasion percolation. By
varying the particle size and contact angle we unambiguously demonstrate that
capillary pressure dominates the drying process.


title:
Painlev\'{e} V and the distribution function of discontinuous linear
  statistics in the Laguerre Unitary Ensembles

abstract:
  In this paper we study the characteristic or generating function of a certain
discontinuous linear statistics of the Laguerre unitary ensembles and show that
this is a particular fifth Painl\'eve transcendant in the variable $t,$ the
position of the discontinuity.
  The proof of the ladder operators adapted to orthogonal polynomial with
discontinuous weight announced sometime ago is presented here, followed by the
non-linear difference equations satisfied by two auxiliary quantities and the
derivation of the Painl\'eve equation.


title:
Efficiency of Rejection-Free Methods for Dynamic Monte Carlo Studies of
  Off-lattice Interacting Particles

abstract:
  We calculate the efficiency of a rejection-free dynamic Monte Carlo method
for $d$-dimensional off-lattice homogeneous particles interacting through a
repulsive power-law potential $r^{-p}$. Theoretically we find the algorithmic
efficiency in the limit of low temperatures and/or high densities is
asymptotically proportional to $\rho^{\tfrac{p+2}{2}}T^{-\tfrac{d}{2}}$ with
the particle density $\rho$ and the temperature $T$. Dynamic Monte Carlo
simulations are performed in 1-, 2- and 3-dimensional systems with different
powers $p$, and the results agree with the theoretical predictions.


title:
Measurement of branching fractions of B0 decays to K1(1270)+ pi- and
  K1(1400)+ pi-

abstract:
  We present a measurement of the branching fraction of neutral B meson
decaying to final states containing a K_1 meson, i.e. K_1(1270) and K_1(1400),
and a charged pion. The data, collected with the BaBar detector at the Stanford
Linear Accelerator Center, represent 454 million BBbar pairs produced in e+e-
annihilation. We measure the branching fraction BF(B0 -> K_1+ pi-) = (31.0 +-
2.7 +- 6.9) x 10^-6, where the first error quoted is statistical and the second
is systematic. In the framework of the K-matrix formalism used to describe
these decays, we also set limits on the ratio of the production constants for
the K_1(1270)+ and K_1(1400)+ mesons in B0 decays.


title:
Certain aperiodic automorphisms of unital simple projectionless
  C*-algebras

abstract:
  Let $G$ be an inductive limit of finite cyclic groups and let $A$ be a unital
simple projectionless C*-algebra with $K_1(A) \cong G$ and with a unique
tracial state, as constructed based on dimension drop algebras by Jiang and Su.
First, we show that any two aperiodic elements in $\Aut(A)/\WInn(A)$ are
conjugate, where $\WInn(A)$ means the subgroup of $\Aut(A)$ consisting of
automorphisms which are inner in the tracial representation.
  In the second part of this paper, we consider a class of unital simple
C*-algebras with a unique tracial state which contains the class of unital
simple AT-algebras of real rank zero with a unique tracial state. This class is
closed under inductive limits and under crossed products by actions of $\Z$
with the Rohlin property. Let $A$ be a TAF-algebra in this class. We show that
for any automorphism $\alpha$ of $A$ there exists an automorphism
$\widetilde{\alpha}$ of $A$ with the Rohlin property such that
$\widetilde{\alpha}$ and $\alpha$ are asymptotically unitarily equivalent. In
its proof we use an aperiodic automorphism of the Jiang-Su algebra.


title:
Backaction noise produced via cavity-aided nondemolition measurement of
  an atomic clock state

abstract:
  We use a quantum nondemolition measurement to probe the collective pseudospin
of an atomic ensemble in a high-finesse optical cavity. We analyze the
backaction antisqueezing produced by the measurement process to show that our
protocol could create conditional spin squeezing in the atomic ensemble.


title: Cryogenic Ion Trapping Systems with Surface-Electrode Traps

abstract:
  We present two simple cryogenic RF ion trap systems in which cryogenic
temperatures and ultra high vacuum pressures can be reached in as little as 12
hours. The ion traps are operated either in a liquid helium bath cryostat or in
a low vibration closed cycle cryostat. The fast turn around time and
availability of buffer gas cooling made the systems ideal for testing
surface-electrode ion traps. The vibration amplitude of the closed cycled
cryostat was found to be below 106 nm. We evaluated the systems by loading
surface-electrode ion traps with $^{88}$Sr$^+$ ions using laser ablation, which
is compatible with the cryogenic environment. Using Doppler cooling we observed
small ion crystals in which optically resolved ions have a trapped lifetime
over 2500 minutes.


title: Jet schemes, invariant chiral differential operators, and Howe duality

abstract: This paper has been withdrawn due to an error in the proof of Theorem 5.3.


title:
Non-random coil behavior as a consequence of extensive PPII structure in
  the denatured state

abstract:
  Unfolded proteins may contain native or non-native residual structure, which
has important implications for the thermodynamics and kinetics of folding as
well as for misfolding and aggregation diseases. However, it has been
universally accepted that residual structure should not affect the global size
scaling of the denatured chain, which obeys the statistics of random coil
polymers. Here we use a single-molecule optical technique, fluorescence
correlation spectroscopy, to probe the denatured state of set of repeat
proteins containing an increasing number of identical domains, from two to
twenty. The availability of this set allows us to obtain the scaling law for
the unfolded state of these proteins, which turns out to be unusually compact,
strongly deviating from random-coil statistics. The origin of this unexpected
behavior is traced to the presence of extensive non-native polyproline II
helical structure, which we localize to specific segments of the polypeptide
chain. We show that the experimentally observed effects of PPII on the size
scaling of the denatured state can be well-described by simple polymer models.
Our findings suggest an hitherto unforeseen potential of non-native structure
to induce significant compaction of denatured proteins, affecting significantly
folding pathways and kinetics.


title: The Large-Scale Atomic and Molecular Gas in the Circinus Galaxy

abstract:
  We have used the ATCA and the SEST to map the large-scale atomic and
molecular gas in the nearby Circinus galaxy. The HI mosaic of Circinus exhibits
the warps in position angle and inclination revealed in the single-pointing
image, both of which appear to settle beyond the inner 30 kpc which was
previously imaged. The molecular gas has been mapped in both the CO
transitions, where we derive a total molecular gas mass of ~2e9 Mo. Within a
radius of 3 kpc, i.e. where CO was clearly detected, the molecular fraction
climbs steeply from ~0.7 to unity with proximity to the nucleus. Our HI mosaic
gives an atomic gas mass of ~6e9 Mo which is 70% of the fully mapped single
dish value. The total neutral gas mass to dynamical mass ratio is therefore 3%,
consistent with the SAS3 classification of Circinus. The high (molecular) gas
mass fraction found previously, only occurs close to the central ~0.5 kpc and
falls to < 10% within and outwith this region, allaying previous concerns
regarding the validity of applying the Galactic conversion ratio to Circinus.
The rotation curve, as traced by both the HI and CO, exhibits a steep dip at ~1
kpc, the edge of the atomic/molecular ring, within which the star-burst is
occurring. We find the atomic and molecular gases to trace different
kinematical features and believe that the fastest part of the sub-kpc ring
consists overwhelmingly of molecular gas. Beyond the inner kpc, the velocity
climbs to settle into a solid body rotation at >10 kpc. Most of the starlight
emanates from within this radius and so much of the dynamical mass, which
remains climbing to the limit of our data (>50 kpc), must be due to the dark
matter halo.


title: Photovoltaic Hall effect in graphene

abstract:
  Response of electronic systems in intense lights (AC electric fields) to DC
source-drain fields is formulated with the Floquet method. We have then applied
the formalism to graphene, for which we show that a non-linear effect of a
circularly polarized light can open a gap in the Dirac cone, which leads to a
photo-induced dc Hall current. This is numerically confirmed for a graphene
ribbon attached to electrodes with the Keldysh Green's function.


title:
Derivation of the nonlinear fluctuating hydrodynamic equation from
  underdamped Langevin equation

abstract:
  We derive the fluctuating hydrodynamic equation for the number and momentum
densities exactly from the underdamped Langevin equation. This derivation is an
extension of the Kawasaki-Dean formula in underdamped case. The steady state
probability distribution of the number and momentum densities field can be
expressed by the kinetic and potential energies. In the massless limit, the
obtained fluctuating hydrodynamic equation reduces to the Kawasaki-Dean
equation. Moreover, the derived equation corresponds to the field equation
derived from the canonical equation when the friction coefficient is zero.


title: Quantum phase transitions of the asymmetric three-leg spin tube

abstract:
  We investigate quantum phase transitions of the S=1/2 three-leg
antiferromagnetic spin tube with asymmetric inter-chain (rung) exchange
interactions. On the basis of the electron tube system, we propose a useful
effective theory to give the global phase diagram of the asymmetric spin tube.
In addition, using other effective theories we raise the reliability of the
phase diagram. The density-matrix renormalization-group and the numerical
diagonalization analyses show that the finite spin gap appears in a narrow
region around the rung-symmetric line, in contrast to a recent paper by
Nishimoto and Arikawa [Phys. Rev. B78, 054421 (2008)]. The numerical
calculations indicate that this global phase diagram obtained by use of the
effective theories is qualitatively correct. In the gapless phase on the phase
diagram, the numerical data are fitted by a finite-size scaling in the c=1
conformal field theory. We argue that all the phase transitions between the
gapful and gapless phases belong to the Berezinskii-Kosterlitz-Thouless
universality class.


title:
Channel Coding and Decoding in a Relay System Operated with Physical
  layer Network Coding

abstract:
  Physical-layer Network Coding (PNC) can significantly improve the throughput
of wireless two way relay channel (TWRC) by allowing the two end nodes to
transmit messages to the relay simultaneously. To achieve reliable
communication, channel coding could be applied on top of PNC. This paper
investigates link-by-link channel-coded PNC, in which a critical process at the
relay is to transform the superimposed channel-coded packets received from the
two end nodes plus noise, Y3=X1+X2+W3, to the network-coded combination of the
source packets, S1 XOR S2 . This is in distinct to the traditional
multiple-access problem, in which the goal is to obtain S1 and S2 separately.
The transformation from Y3 to (S1 XOR S2) is referred to as the
Channel-decoding-Network-Coding process (CNC) in that it involves both channel
decoding and network coding operations. A contribution of this paper is the
insight that in designing CNC, we should first (i) channel-decode Y3 to the
superimposed source symbols S1+S2 before (ii) transforming S1+S2 to the
network-coded packets (S1 XOR S2) . Compared with previously proposed
strategies for CNC, this strategy reduces the channel-coding network-coding
mismatch. It is not obvious, however, that an efficient decoder for step (i)
exists. A second contribution of this paper is to provide an explicit
construction of such a decoder based on the use of the Repeat Accumulate (RA)
code. Specifically, we redesign the belief propagation algorithm of the RA code
for traditional point-to-point channel to suit the need of the PNC
multiple-access channel. Simulation results show that our new scheme
outperforms the previously proposed schemes significantly in terms of BER
without added complexity.


title:
Centrality-dependent direct photon pt spectra in Au+Au collisions at
  RHIC

abstract:
  We calculate the centrality-dependence of transverse momentum ($\pt$) spectra
for direct photons in Au+Au collisions at the RHIC energy, based on a realistic
data-constrained (3+1) dimensional hydrodynamic description of the expanding
hot and dense matter, a reasonable treatment of the propagation of partons and
their energy loss in the fluid, and a systematic study of the main sources of
direct photons. The resultant $\pt$ spectra agree with recent PHENIX data in a
broad $\pt$ range. The competition among the different direct photon sources is
investigated at various centralities. Parton energy loss in the plasma is
considered for photons from fragmentation and jet photon conversion, which
causes about 40% decrease in the total contribution. In the high $\pt$ region,
the observed $R_{AA}$ of photons is centrality independent at the accuracy of
5% based on a realistic treatment of energy loss. We also link the different
behavior of $R_{AA}$ for central and peripheral collisions, in the low $\pt$
region, to the fact that the plasma in central collisions is hotter compared to
peripheral ones.


title:
Extinction in a self-regulating population with demographic and
  environmental noise

abstract:
  We present an explicit unified stochastic model of fluctuations in population
size due to random birth, death, density-dependent competition and
environmental fluctuations. Stochastic dynamics provide insight into small
populations, including processes such as extinction, that cannot be correctly
treated by deterministic methods. We present exact analytical and
simulation-based results for extinction times of our stochastic model and
compare the different effects of environmental stochasticity and intrinsic
demographic stochasticity. We use both the discrete master equation approach
and an exact mapping to a Fokker-Planck equation (the Poisson method) and
stochastic equation, showing they are precisely equivalent. We also calculate
approximate extinction times using a steepest descent method. This model can
readily be extended to accommodate metapopulation structure and genetic
variation in the population and thus represents a step towards a
microscopically explicit synthesis of population dynamics and population
genetics.


title: Thresholdless dressed-atom laser in a photonic band-gap material

abstract:
  We demonstrate the capability of complete thresholdless lasing operation
between dressed states of a two-level atom located inside a microscopic cavity
engineered in a photonic band-gap material. We distinguish between threshold
and thresholdless behaves by analyzing the Mandel's Q parameter for the cavity
field. We find that the threshold behave depends on whether the spontaneous
emission is or is not present on the lasing transition. In the presence of the
spontaneous emission, the mean photon number of the cavity field exhibits
threshold behavior indicating that the system may operate as an ordinary laser.
When the spontaneous emission is eliminated on the lasing transition, no
threshold is observed for all values of the pumping rate indicating the system
becomes a thresholdless laser. Moreover, we find that under a thresholdless
operation, the mean photon number can increase nonlinearly with the pumping
rate, and this process is accompanied by a sub-Poisson statistics of the field.
This suggests that the nonclassical statistics can be used to distinguish a
nonlinear operation of the dressed-atom laser.


title:
Thermo-optic noise in coated mirrors for high-precision optical
  measurements

abstract:
  Thermal fluctuations in the coatings used to make high-reflectors are
becoming significant noise sources in precision optical measurements and are
particularly relevant to advanced gravitational wave detectors. There are two
recognized sources of coating thermal noise, mechanical loss and thermal
dissipation. Thermal dissipation causes thermal fluctuations in the coating
which produce noise via the thermo-elastic and thermo-refractive mechanisms. We
treat these mechanisms coherently, give a correction for finite coating
thickness, and evaluate the implications for Advanced LIGO.


title: Superconductivity close to magnetic instability in Fe(Se1-xTex)0.82

abstract:
  We report our study of the evolution of superconductivity and the phase
diagram of the ternary Fe(Se1-xTex)0.82 (0<=x<=1.0) system. We discovered a new
superconducting phase with Tc,max = 14 K in the 0.3 < x < 1.0 range. This
superconducting phase is suppressed when the sample composition approaches the
end member FeTe0.82, which exhibits an incommensurate antiferromagnetic order.
We discuss the relationship between the superconductivity and magnetism of this
material system in terms of recent results from neutron scattering
measurements. Our results and analyses suggest that superconductivity in this
new class of Fe-based compounds is associated with magnetic fluctuations, and
therefore may be unconventional in nature.


title: Center and representations of infinitesimal Hecke algebras of sl_2

abstract:
  In this paper, we compute the center of the infinitesimal Hecke algebras Hz
associated to sl_2 ; then using nontriviality of the center, we study
representations of these algebras in the framework of the BGG category O. We
also discuss central elements in infinitesimal Hecke algebras over gl(n) and
sp(2n) for all n. We end by proving an analogue of the theorem of Duflo for Hz.


title:
Anomalous quartic WWgammagamma and WWZgamma couplings through WWZ
  production in gamma gamma colliders

abstract:
  We find 95% confidence level limits on the anomalous coupling parameters
$a_0$, $a_c$ and $a_n$ with an integrated luminosity of $500fb^{-1}$ and $\sqrt
s =0.5, 1$ and 1.5 TeV energies. We take into account incoming beam
polarizations and also the final state polarizations of the gauge bosons in the
cross-section calculations to improve the bounds. We show that polarization
leads to a significant amount of improvement in the sensitivity limits.


title:
Coupling convectively driven atmospheric circulation to surface
  rotation: Evidence for active methane weather in the observed spin rate drift
  of Titan

abstract:
  A large drift in the rotation rate of Titan observed by Cassini provided the
first evidence of a subsurface ocean isolating the massive core from the icy
crust. Seasonal exchange of angular momentum between the surface and atmosphere
accounts for the magnitude of the effect, but observations lag the expected
signal by a few years. We argue that this time lag is due to the presence of an
active methane weather cycle in the atmosphere. An analytic model of the
seasonal cycle of atmospheric angular momentum is developed and compared with
time-dependent simulations of Titan's atmosphere with and without methane
thermodynamics. The disappearance of clouds at the summer pole suggests the
drift rate has already switched direction, signaling the change in season from
solstice to equinox.


title:
Dynamics revealed by correlations of time-distributed weak measurements
  of a single spin

abstract:
  We show that the correlations in stochastic outputs of time-distributed weak
measurements can be used to study the dynamics of an individual quantum object,
with a proof-of-principle setup based on small Faraday rotation caused by a
single spin in a quantum dot. In particular, the third order correlation can
reveal the "true" spin decoherence, which would otherwise be concealed by the
inhomogeneous broadening effect in the second order correlations. The viability
of such approaches lies in that (1) in weak measurement the state collapse
which would disturb the system dynamics occurs at a very low probability, and
(2) a shot of measurement projecting the quantum object to a known basis state
serves as a starter or stopper of the evolution without pumping or coherently
controlling the system as otherwise required in conventional spin echo.


title: On the colored Jones polynomials of certain cable of the torus knots

abstract:
  In this paper, we study the asymptotic behavior of the colored Jones
polynomials evaluated at roots of unity for a special class of knots. We show
that certain limit is zero as predicted by the volume conjecture.


title:
Determination of Landau Fermi-liquid parameters of strongly interacting
  fermions by means of a nonlinear scaling transformation

abstract:
  A nonlinear transformation approach is formulated for the correlated
fermions' thermodynamics through a medium-scaling effective action. An
auxiliary implicit variable-effective chemical potential is introduced to
characterize the non-Gaussian fluctuations physics. By incorporating the
nonlocal correlation effects, the achieved grand partition function is made of
coupled highly nonlinear parametric equations. Analytically, the low
temperature expansions for the strongly interacting unitary Fermi gas are
performed for the adiabatic compressibility-sound speed and specific heat with
the Sommerfeld lemma. The expressions for the Landau Fermi-Liquid parameters
$F_0^s$ and $F_1^s$ of the strongly interacting fermion system are obtained. As
a universal constant, the effective fermion mass ratio is $m^*/m={10/9}$ at
unitarity.

categories: cond-mat.stat-mech cond-mat.quant-gas hep-ph nucl-th


title: The escape fraction of ionizing photons from high redshift galaxies

abstract:
  The fraction of ionizing photons which escape their host galaxy and so are
able to ionize hydrogen in the inter-galactic medium (IGM) is a critical
parameter in studies of the reionization era and early galaxy formation. In
this paper we combine observations of Lyman-alpha absorption towards high
redshift quasars with the measured UV luminosity function of high redshift
galaxies to constrain the escape fraction (f_esc) of ionizing photons from
galaxies at z ~ 5.5-6. The observed Lyman-alpha transmission constrains the
escape fraction to lie in the range f_esc ~ 10-25 % (at z ~ 5.5-6). Excluding
halos with M< 10^10 M_sun (as might be expected if galaxy formation is
suppressed due to the reionization of the IGM) implies a larger escape fraction
of f_esc ~ 20-45 %. Using the numerical results to calibrate an analytic
relation between the escape fraction and minimum galaxy halo mass we also
extrapolate our results to a mass (M~10^8 M_sun) corresponding to the hydrogen
cooling threshold. In this case we find f_esc ~ 5-10 %, consistent with
observed estimates at lower redshift. We find that the escape fraction of high
redshift galaxies must be greater than 5 % irrespepctive of galaxy mass. Based
on these results we use a semi-analytic description to model the reionization
history of the IGM, assuming ionizing sources with escape fractions suggested
by our numerical simulations. We find that the IBG observed at z ~ 5.5-6
implies a sufficient number of ionizing photons to have reionized the Universe
by z ~ 6. However, if the minimum mass for star-formation were greater than
10^9 M_sun, the IBG would be over-produced at redshifts less than z ~ 5. In
summary, our results support a scenario in which the IGM was reionized by low
mass galaxies.


title:
Digital image restoration based on pixel simultaneous detection
  probabilities

abstract:
  Here an image restoration on the basis of pixel simultaneous detection
probabilities (PSDP) is proposed. These probabilities can be precisely
determined by means of correlations measurement [NIMA 586 (2008) 314-326]. The
proposed image restoration is based on the solution of matrix equation.
Non-zero elements of Toeplitz block matrix with ones on the main diagonal, is
determined using PSDP. The number of non zero descending diagonals depends on
the detector construction and is not always smaller than 8. To solve the matrix
equation, the Gaussian elimination algorithm is used. The proposed restoration
algorithm is studied by means of the simulated images (with and without
additive noise using PSDP for General Electric Senographe 2000D mammography
device detector) and a small area (160x160 pixels) of real images acquired by
the above mentioned device. The estimation errors of PSDP and the additive
noise magnitude permits to restore images with the precision better than 3% for
the above mentioned detector. The additive noise in the real image is present
after restoration and almost has the same magnitude. In the restored small area
(16x16 mm) of real images, the pixel responses are not correlated. The spatial
resolution improvement is also analyzed by the image of an absorber edge.


title: Network Evolution of Body Plans

abstract:
  Segmentation in arthropod embryogenesis represents a well-known example of
body plan diversity. Striped patterns of gene expression that lead to the
future body segments appear simultaneously or sequentially in long and short
germ-band development, respectively. Regulatory genes relevant for stripe
formation are evolutionarily conserved among arthropods, therefore the
differences in the observed traits are thought to have originated from how the
genes are wired. To reveal the basic differences in the network structure, we
have numerically evolved hundreds of gene regulatory networks that produce
striped patterns of gene expression. By analyzing the topologies of the
generated networks, we show that the characteristics of stripe formation in
long and short germ-band development are determined by Feed-Forward Loops
(FFLs) and negative Feed-Back Loops (FBLs) respectively. Network architectures,
gene expression patterns and knockout responses exhibited by the artificially
evolved networks agree with those reported in the fly Drosophila melanogaster
and the beetle Tribolium castaneum. For other arthropod species, principal
network architectures that remain largely unknown are predicted.


title:
Strong Incompatability of Tribimaximal Mixing with Quark-Lepton
  Complementarity

abstract:
  Although tribimaximal mixing (TBM) and quark-lepton complementarity (QLC) are
both compatible with experimental data within one standard deviation ($ 1
\sigma$), the TBM and QLC assumptions are mutually exclusive by $56 \sigma$.


title:
Rapid spectral and timing variability of Be/X-ray binaries during type
  II outbursts

abstract:
  We have investigated the spectral and timing variability of four accreting
X-ray pulsars with Be-type companions during major X-ray outbursts. Different
spectral states were defined according to the value of the X-ray colours and
flux. Transient Be/X-ray binaries exhibit two branches in their colour-colour
and colour-intensity diagrams: the horizontal branch corresponds to a
low-intensity state and shows the larger fractional rms, similar to the the
island state in atolls and horizontal branch in Z sources; the diagonal branch
corresponds to a high-intensity state, in which the source spends about 75% of
the total duration of the outburst. Despite the complexity of the power spectra
due to the peaks of the pulse period and its harmonics, the aperiodic
variability of Be/X-ray binaries can be described with a relatively low number
of Lorentzian components. Some of these components can be associated with the
same type of noise as that seen in low-mass X-ray binaries, although the
characteristic frequencies are about one order of magnitude lower. The pattern
traced by V 0332+53 results in a Z shaped track, similar to the low-mass Z
sources, without the flaring branch. In contrast, the horizontal branch in 4U
0115+63, KS 1947+300 and EXO 2030+375 corresponds to a low/soft state, not seen
in other types of X-ray binaries. The noise at very low frequencies follows a
power law in V 0332+53 (like in LMXB Z) and it is flat-topped in 4U 0115+63, KS
1947+300 and EXO 2030+375 (like in LMXB atoll). V 0332+53 shows a noise
component coupled with the periodic variability that it is not seen in any of
the other three sources.


title: Nonlinear photonic crystals near the supercollimation point

abstract:
  We uncover a strong coupling between nonlinearity and diffraction in a
photonic crystal at the supercollimation point. We show this is modeled by a
nonlinear diffraction term in a nonlinear schroedinger type equation, in which
the properties of solitons are investigated. Linear stability analysis shows
solitons are stable in an existence domain that obeys the Vakhitov-Kolokolov
criterium. In addition, we investigate the influence of the nonlinear
diffraction on soliton collision scenarios.


title: Efficient purification protocols using iSWAP gates in solid-state qubits

abstract:
  We show an efficient purification protocol in solid-state qubits by replacing
the usual bilateral CNOT gate by the bilateral iSWAP gate. We also show that
this replacement can be applied to breeding and hashing protocols, which are
useful for quantum state purification. These replacements reduce the number of
fragile and cumbersome two-qubit operations, making more feasible
quantum-information-processing with solid-state qubits. As examples, we also
present quantitative analyses for the required time to perform state
purification using either superconducting or semiconducting qubits.


title: Rotating surface soliton complexes in annular waveguides

abstract:
  We address surface soliton complexes formed at the edge of annular guiding
structures containing several concentric rings. Such soliton complexes feature
a -phase difference between neighboring spots. It is shown that the
multipole-mode solitons can rotate steadily upon propagation, and the existence
domain is strongly affected by the rotation frequency. The rotation may enhance
the stabilization of surface multipole-mode solitons.


title: Wild cyclic-by-tame extensions

abstract:
  Suppose G is a semi-direct product of the form Z/p^n \rtimes Z/m where p is
prime and m is relatively prime to p. Suppose K is a local field of
characteristic p > 0. The main result states necessary and sufficient
conditions on the ramification filtrations that occur for wildly ramified
G-Galois extensions of K. In addition, we prove that there exists a parameter
space for G-Galois extensions of K with given ramification filtration whose
dimension depends only on the ramification filtration. We provide explicit
equations for wild cyclic extensions of K of degree p^3.


title:
Metal to insulator transition in epitaxial graphene induced by molecular
  doping

abstract:
  The capability to control the type and amount of charge carriers in a
material and, in the extreme case, the transition from metal to insulator is
one of the key challenges of modern electronics. By employing angle resolved
photoemission spectroscopy (ARPES) we find that a reversible metal to insulator
transition and a fine tuning of the charge carriers from electrons to holes can
be achieved in epitaxial bilayer and single layer graphene by molecular doping.
The effects of electron screening and disorder are also discussed. These
results demonstrate that epitaxial graphene is suitable for electronics
applications, as well as provide new opportunities for studying the hole doping
regime of the Dirac cone in graphene.


title: Two-color surface lattice solitons

abstract:
  We study the properties of surface solitons generated at the edge of a
semi-infinite photonic lattice in nonlinear quadratic media, namely two-color
surface lattice solitons. We analyze the impact of phase mismatch on existence
and stability of surface modes, and find novel classes of two-color twisted
surface solitons which are stable in a large domain of their existence.


title: Random Time-Scale Invariant Diffusion and Transport Coefficients

abstract:
  Single particle tracking of mRNA molecules and lipid granules in living cells
shows that the time averaged mean squared displacement $\overline{\delta^2}$ of
individual particles remains a random variable while indicating that the
particle motion is subdiffusive. We investigate this type of ergodicity
breaking within the continuous time random walk model and show that
$\overline{\delta^2}$ differs from the corresponding ensemble average. In
particular we derive the distribution for the fluctuations of the random
variable $\overline{\delta^2}$. Similarly we quantify the response to a
constant external field, revealing a generalization of the Einstein relation.
Consequences for the interpretation of single molecule tracking data are
discussed.


title: Rabi Oscillations in Landau-Quantized Graphene

abstract:
  We investigate the relation between the canonical model of quantum optics,
the Jaynes-Cummings Hamiltonian and Dirac fermions in quantizing magnetic
field. We demonstrate that Rabi oscillations are observable in the optical
response of graphene, providing us with a transparent picture about the
structure of optical transitions. While the longitudinal conductivity reveals
chaotic Rabi oscillations, the Hall component measures coherent ones. This
opens up the possibility of investigating a microscopic model of a few quantum
objects in a macroscopic experiment with tunable parameters.


title: Incompressible one-sided surfaces in filled link spaces

abstract:
  When a Dehn filled link manifold contains a geometrically incompressible
one-sided surface, it is shown there is a unique boundary incompressible
position that the surface can take in the link space. The proof uses a version
of the sweep-out technique from two-sided Heegaard splitting theory. When
applied to one-sided Heegaard splittings, this result can be used to complete
the classification of one-sided splittings of (2p, q) fillings of Figure 8 knot
space: determining that fillings with |2p/q|<3 have two non-isotopic
geometrically incompressible one-sided splitting surfaces.


title: Phase diagram of the asymmetric tetrahedral Ising-Heisenberg chain

abstract:
  The asymmetric tetrahedron is composed by all edges of tetrahedron
represented by Ising interaction except one, which has a Heisenberg type
interaction. This asymmetric tetrahedron is arranged connecting a vertex which
edges are only Ising type interaction to another vertex with same structure of
another tetrahedron. The process is replicated and this kind of lattice we call
the asymmetric Ising-Heisenberg chain. We have studied the ground state phase
diagram for this kind of models. Particularly we consider two situations in the
Heisenberg-type interaction, (i) The asymmetric tetrahedral spin(1/2,1/2)
Ising-XYZ chain, and (ii) the asymmetric tetrahedral spin-(1/2,1) Ising-XXZ
chain, where we have found a rich phase diagram and a number of multicritical
points. Additionally we have also studied their thermodynamics properties and
the correlation function, using the decorated transformation. We have mapped
the asymmetric tetrahedral Ising-Heisenberg chain in an effective Ising chain,
and we have also concluded that it is possible to evaluate the partition
function including a longitudinal external magnetic field.


title:
Transitions in the computational power of thermal states for
  measurement-based quantum computation

abstract:
  We show that the usefulness of the thermal state of a specific spin-lattice
model for measurement-based quantum computing exhibits a transition between two
distinct "phases" - one in which every state is a universal resource for
quantum computation, and another in which any local measurement sequence can be
simulated efficiently on a classical computer. Remarkably, this transition in
computational power does not coincide with any phase transition, classical or
quantum, in the underlying spin-lattice model.


title:
Testing the nature of the $\Lambda$(1520) in the
  $J/\psi\to\bar{\Lambda}K^-p$ and $J/\psi\to\bar{\Lambda}\pi^+\pi^-\Lambda$
  reactions

abstract:
  We study the reactions $J/\psi\to\bar{\Lambda}K^-p$ and
$J/\psi\to\bar{\Lambda}\pi^+\pi^-\Lambda$ with a unitary chiral approach. We
predict the ratio of the invariant mass distributions of these two reactions at
the $\Lambda(1520)$ peak position, which is free of the unknown production
mechanism and reflects only the properties of the $\Lambda(1520)$. An
experimental measurement of this ratio will provide the couplings of the
$\Lambda(1520)$ to its decay channels, allowing to test the predictions of the
chiral unitary approach on this resonance, which appears as dynamically
generated in that approach.


title:
Peak reduction and finite presentations for automorphism groups of
  right-angled Artin groups

abstract:
  We generalize the peak-reduction algorithm (Whitehead's theorem) for free
groups to a theorem about a general right-angled Artin group A_Gamma. As an
application, we find a finite presentation for the automorphism group Aut
A_Gamma that generalizes McCool's presentation for the automorphism group of a
finite rank free group. We also give consider a stronger generalization of
peak-reduction, giving a counterexample and proving a special case.


title: Toric cohomological rigidity of simple convex polytopes

abstract:
  A simple convex polytope $P$ is \emph{cohomologically rigid} if its
combinatorial structure is determined by the cohomology ring of a quasitoric
manifold over $P$. Not every $P$ has this property, but some important
polytopes such as simplices or cubes are known to be cohomologically rigid. In
this article we investigate the cohomological rigidity of polytopes and
establish it for several new classes of polytopes including products of
simplices. Cohomological rigidity of $P$ is related to the \emph{bigraded Betti
numbers} of its \emph{Stanley--Reisner ring}, another important invariants
coming from combinatorial commutative algebra.


title:
Symplectic structures on right-angled Artin groups: between the mapping
  class group and the symplectic group

abstract:
  We define a family of groups that include the mapping class group of a genus
g surface with one boundary component and the integral symplectic group
Sp(2g,Z). We then prove that these groups are finitely generated. These groups,
which we call mapping class groups over graphs, are indexed over labeled
simplicial graphs with 2g vertices. The mapping class group over the graph
Gamma is defined to be a subgroup of the automorphism group of the right-angled
Artin group A_Gamma of Gamma. We also prove that the kernel of the map Aut
A_Gamma to Aut H_1(A_Gamma) is finitely generated, generalizing a theorem of
Magnus.


title: Matrix representations for toric parametrizations

abstract:
  In this paper we show that a surface in P^3 parametrized over a 2-dimensional
toric variety T can be represented by a matrix of linear syzygies if the base
points are finite in number and form locally a complete intersection. This
constitutes a direct generalization of the corresponding result over P^2
established in [BJ03] and [BC05]. Exploiting the sparse structure of the
parametrization, we obtain significantly smaller matrices than in the
homogeneous case and the method becomes applicable to parametrizations for
which it previously failed. We also treat the important case T = P^1 x P^1 in
detail and give numerous examples.


title: Barycentric decomposition of quantum measurements in finite dimensions

abstract:
  We analyze the convex structure of the set of positive operator valued
measures (POVMs) representing quantum measurements on a given finite
dimensional quantum system, with outcomes in a given locally compact Hausdorff
space. The extreme points of the convex set are operator valued measures
concentrated on a finite set of k \le d^2 points of the outcome space, d<
\infty being the dimension of the Hilbert space. We prove that for second
countable outcome spaces any POVM admits a Choquet representation as the
barycenter of the set of extreme points with respect to a suitable probability
measure. In the general case, Krein-Milman theorem is invoked to represent
POVMs as barycenters of a certain set of POVMs concentrated on k \le d^2 points
of the outcome space.


title:
Dirac equation for quasi-particles in graphene and quantum field theory
  of their Coulomb interaction

abstract:
  There is evidence for existence of massless Dirac quasi-particles in
graphene, which satisfy Dirac equation in (1+2) dimensions near the so called
Dirac points which lie at the corners at the graphene's brilluoin zone. We
revisit the derivation of Dirac equation in (1+2) dimensions obeyed by
quasiparticles in graphene near the Dirac points. It is shown that parity
operator in (1+2) dimensions play an interesting role and can be used for
defining "conserved" currents resulting from the underlying Lagrangian for
Dirac quasi-particles in graphene which is shown to have U_{A}(1)*U_{B}(1)
symmetry. Further the quantum field theory (QFT) of Coulomb interaction of 2D
graphene is developed and applied to vacuum polarization and electron self
energy and the renormalization of the effective coupling g of this interaction
and Fermi velocity $v_{f}$ which has important implications in the
renormalization group analysis of g and v_{f}.


title: Reheating induced by competing decay modes

abstract:
  We address the problem of studying the decay of the inflaton field $\phi$ to
another scalar field $\chi$ through parametric resonance in the case of a
coupling that involves several decay modes. This amounts to the presence of
extra harmonic terms in the perturbation of the $\chi$ field dynamics. For the
case of two frequencies we compute the geometry of the resonance regions, which
is significantly altered due to the presence of non-cuspidal resonance regions
associated to higher harmonics and to the emergence of instability `pockets'.
We discuss the effect of this change in the efficiency of the energy transfer
process for the simplest case of a coupling given by a combination of the two
interaction terms of homogeneous degree usually considered in the literature.
We find that the presence of higher harmonics has limited cosmological
implications.


title: On the evidence for narrow, relativistically shifted X-ray lines

abstract:
  In recent years there have been many reported detections of highly redshifted
or blueshifted narrow spectral lines (both emission or absorption) in the X-ray
spectra of active galaxies, but these are all modest detections in terms of
their statistical significance. The aim of this paper is to review the issue of
the significance of these detections and, in particular, take account of
publication bias. A literature search revealed 38 reported detections of
narrow, strongly shifted (v/c >= 0.05) X-ray lines in the 1.5-20 keV spectra of
Seyfert galaxies and quasars. These published data show a close, linear
relationship between the estimated line strength and its uncertainty, in the
sense that better observations (with smaller uncertainties) only ever show the
smallest lines. This result is consistent with many of the reported lines being
false detections resulting from random fluctuations, drawn from a large body of
data and filtered by publication bias such that only the most `significant'
fluctuations are ever reported. The reality of many of these features, and
certainly their prevalence in the population at large, therefore remains an
open question that is best settled though uniform analysis (and reporting) of
higher quality observations.


title: H2-optimal approximation of MIMO linear dynamical systems

abstract:
  We consider the problem of approximating a multiple-input multiple-output
(MIMO) $p\times m$ rational transfer function $H(s)$ of high degree by another
$p\times m$ rational transfer function $\hat H(s)$ of much smaller degree, so
that the ${\cal H}_2$ norm of the approximation error is minimized. We
characterize the stationary points of the ${\cal H}_2$ norm of the
approximation error by tangential interpolation conditions and also extend
these results to the discrete-time case. We analyze whether it is reasonable to
assume that lower-order models can always be approximated arbitrarily closely
by imposing only first-order interpolation conditions. Finally, we analyze the
${\cal H}_2$ norm of the approximation error for a simple case in order to
illustrate the complexity of the minimization problem.


title: Transformations of algebraic Gauss hypergeometric functions

abstract:
  A celebrated theorem of Klein implies that any hypergeometric differential
equation with algebraic solutions is a pull-back of one of the few standard
hypergeometric equations with algebraic solutions. The most interesting cases
are hypergeometric equations with tetrahedral, octahedral or icosahedral
monodromy groups. We give an algorithm for computing Klein's pull-back
coverings in these cases, based on certain explicit expressions (Darboux
evaluations) of algebraic hypergeometric functions. The explicit expressions
can be computed using contiguous relations and a data base of simplest Darboux
evaluations (covering the Schwarz table). Klein's pull-back transformations
also induce algebraic transformations between hypergeometric solutions and a
standard hypergeometric function with the same finite monodromy group.


title:
Trinucleon Electromagnetic Form Factors and the Light-Front Hamiltonian
  Dynamics

abstract:
  This contribution briefly illustrates preliminary calculations of the
electromagnetic form factors of $^3$He and $^3$H, obtained within the
Light-front Relativistic Hamiltonian Dynamics, adopting i) a Poincar\'e
covariant current operator, without dynamical two-body currents, and ii)
realistic nuclear bound states with $S$, $P$ and $D$ waves. The kinematical
region of few $(GeV/c)^2$, relevant for forthcoming TJLAB experiments, has been
investigated, obtaining possible signatures of relativistic effects for
$Q^2>2.5 ~(GeV/c)^2$.


title:
The influence of the stationary electric field upon the resonance
  absorption of microwaves in HeII

abstract:
  The interaction between electromagnetic microwaves (40-200 GHz) and
superfluid helium in a stationary electric field has been investigated
experimentally. It is found that the narrow line of resonance absorption at the
roton frequency is split in the electric field into two symmetric lines. The
splitting magnitude increases almost linearly with the electric field, which
suggests a linear Stark effect. The results obtained point of orientational
polarizability and dipole moment (10^(-34)C*m) in HeII. It is shown that the
spectral line profile consists of two parts - a narrow line of resonance
absorption (or induced radiation when superfluid stream are generated) and a
broad background. The background with agrees well with the latest neutron data
for the roton line.


title: Deforming the Lie Superalgebra $\mathcal{K}(1)$-Modules Of Symbols

abstract:
  We study non-trivial deformations of the natural action of the Lie
superalgebra $mathcalK(1)$ of contact vector fields on the (1,1)-dimensional
superspace $mathbbR^{1|1}$ of th espace of symbols.
  We calculate obstructions for integrability of infinitesimal multi-parameter
deformation and determine the complete commutative algebra corresponding to the
miniversal deformation in the sense of A. Fialowski.
  Besides, we compute the first even differential cohomology space
$mathrmH^1_{mathrm{diff}}(cK(1);widetilde{cD}_{lambda,mu})$ of the Lie
superalgebra $mathcalK(1)$ of contact vector fields on the (1,1)-dimensional
superspace $mathbbR^{1|1}$ with coefficients in the superspace
$widetilde{mathcalD}_{lambda,mu}$ of linear differential operators from the
superspace of weighted densities $\fF_{\lamda}$ to $\fF_{\mu}$. (To appear in
Journal of Generalized Lie Theory and Applications)


title: Population extinction in a time-modulated environment

abstract:
  The extinction time of an isolated population can be exponentially reduced by
a periodic modulation of its environment. We investigate this effect using, as
an example, a stochastic branching-annihilation process with a time-dependent
branching rate. The population extinction is treated in eikonal approximation,
where it is described as an instanton trajectory of a proper reaction
Hamiltonian. The modulation of the environment perturbs this trajectory and
synchronizes it with the modulation phase. We calculate the corresponding
change in the action along the instanton using perturbation techniques
supported by numerical calculations. The techniques include a first-order
theory with respect to the modulation amplitude, a second-order theory in the
spirit of the Kapitsa pendulum effect, and adiabatic theory valid for low
modulation frequencies.


title: Force-clamp spectroscopy of reversible bond breakage

abstract:
  We consider reversible breaking of adhesion bonds or folding of proteins
under the influence of a constant external force. We discuss the stochastic
properties of the unbinding/rebinding events and analyze their mean number and
their variance in the framework of simple two-state models. In the
calculations, we exploit the analogy to single molecule fluorescence and
particularly between unbinding/rebinding and photon emission events.
Environmental fluctuation models are used to describe deviations from Markovian
behavior. The second moment of the event-number distribution is found to be
very sensitive to possible exchange processes and can thus be used to identify
temporal fluctuations of the transition rates.


title:
Universality in the two matrix model: a Riemann-Hilbert steepest descent
  analysis

abstract:
  The eigenvalue statistics of a pair $(M_1,M_2)$ of $n\times n$ Hermitian
matrices taken random with respect to the measure
  $$\frac{1}{Z_n}\exp\big(-n\Tr (V(M_1)+W(M_2)-\tau M_1M_2)\big) {\rm d}M_1
{\rm d} M_2 $$ can be described in terms of two families of biorthogonal
polynomials. In this paper we give a steepest descent analysis of a $4 \times
4$ matrix-valued Riemann-Hilbert problem characterizing one of the families of
biorthogonal polynomials in the special case $W(y)=y^4/4$ and $V$ an even
polynomial. As a result we obtain the limiting behavior of the correlation
kernel associated to the eigenvalues of $M_1$ (when averaged over $M_2$) in the
global and local regime as $n\to \infty$ in the one-cut regular case. A special
feature in the analysis is the introduction of a vector equilibrium problem
involving both an external field and an upper constraint.


title: Mixing-induced CP violating sources for electroweak baryogenesis

abstract:
  The effects of flavor mixing in electroweak baryogenesis is investigated in a
generalized semiclassical WKB approach. Through calculating the nonadiabatic
corrections to the particle currents it is shown that extra CP violation
sources arise from the off-diagonal part of the equation of motion of particles
moving inside the bubble wall. The numerical importance of the mixing-induced
source is discussed in the Minimal Supersymmetric Standard Model and compared
with the source term induced by semiclassical force.


title:
Mass transfer variation in the outburst model of dwarf novae and soft
  X-ray transients

abstract:
  We discuss two mechanisms that could result in an enhancement of the mass
transfer rate during outbursts of dwarf novae and soft X-ray transients: the
hot outer disc rim itself could heat the L1 point and scattered radiation by
optically thin outflowing matter could also heat L1 significantly. We determine
quantitatively the increase of the mass transfer rate resulting from an extra
heating. During outbursts, the disc edge heats up the upper layer of the
secondary with a flux of the order of the intrinsic stellar flux. This probably
has no large effect on the mass transfer rate. In soft X-ray transients, the
environing medium of the disc (corona+wind) could back-scatter a certain
fraction of the accretion luminosity toward L1. Since soft X-ray transients
reach high luminosities, even a low efficiency of this effect could yield a
significant heating of L1, whereas we show that in dwarf novae this effect is
negligible. Initially the incoming radiation does not penetrate below the
photosphere of the secondary. Depending on the heating efficiency, which has to
be determined, the mass transfer rate could be significantly increased (~x100).


title: Singular cotangent model

abstract:
  Any singular level of a completely integrable system (c.i.s.) with
non-degenerate singularities has a singular affine structure. We shall show how
to construct a simple c.i.s. around the level, having the above affine
structure. The cotangent budle of the desingularised level is used to perform
the construction, and the c.i.s. obtained looks like the simplest one
associated to the affine structure. This method of construction is used to
provide several examples of c.i.s. with different kinds of non-degenerate
singularities.


title:
Torus quotients of homogeneous spaces-minimal dimensional Schubert
  Variety admitting semi-stable points

abstract:
  In this paper, for any simple, simply connected algebraic group $G$ of type
$B_n,C_n$ or $D_n$ and for any maximal parabolic subgroup $P$ of $G$, we
describe all minimal dimensional Schubert varieties in $G/P$ admitting
semistable points for the action of a maximal torus $T$ with respect to an
ample line bundle on $G/P$. In this paper, we also describe, for any
semi-simple simply connected algebraic group $G$ and for any Borel subgroup $B$
of $G$, all Coxeter elements $\tau$ for which the Schubert variety $X(\tau)$
admits a semistable point for the action of the torus $T$ with respect to a
non-trivial line bundle on
  $G/B$.


title: Thermal Noise on Adiabatic Quantum Computation

abstract:
  The success of adiabatic quantum computation (AQC) depends crucially on the
ability to maintain the quantum computer in the ground state of the evolution
Hamiltonian. The computation process has to be sufficiently slow as restricted
by the minimal energy gap. However, at finite temperatures, it might need to be
fast enough to avoid thermal excitations. The question is, how fast does it
need to be? The structure of evolution Hamiltonians for AQC is generally too
complicated for answering this question. Here we model an adiabatic quantum
computer as a (parametrically driven) harmonic oscillator. The advantages of
this model are (1) it offers high flexibility for quantitative analysis on the
thermal effect, (2) the results qualitatively agree with previous numerical
calculation, and (3) it could be experimentally verified with quantum
electronic circuits.


title: Data analysis recipes: Choosing the binning for a histogram

abstract:
  Data points are placed in bins when a histogram is created, but there is
always a decision to be made about the number or width of the bins. This
decision is often made arbitrarily or subjectively, but it need not be. A
jackknife or leave-one-out cross-validation likelihood is defined and employed
as a scalar objective function for optimization of the locations and widths of
the bins. The objective is justified as being related to the histogram's
usefulness for predicting future data. The method works for data or histograms
of any dimensionality.


title: Sivers function in constituent quark models

abstract:
  A formalism to evaluate the Sivers function, developed for calculations in
constituent quark models, is applied to the Isgur-Karl model. A non-vanishing
Sivers asymmetry, with opposite signs for the u and d flavor, is found; the
Burkardt sum rule is fulfilled up to 2 %. Nuclear effects in the extraction of
neutron single spin asymmetries in semi-inclusive deep inelastic scattering off
3He are also evaluated. In the kinematics of JLab, it is found that the nuclear
effects described by an Impulse Approximation approach are under control.


title: Sur le corps des modules de certaines vari\'et\'es

abstract:
  To every covering of curves, we associate several varieties having the same
field of moduli and same fields of definition. We deduce examples of curves
having Q (the field of rationals) as field of moduli, that admit models over
any completion of Q but no model over Q.