title: Partial differential equations driven by rough paths

abstract:
  We study a class of linear first and second order partial differential
equations driven by weak geometric $p$-rough paths, and prove the existence of
a unique solution for these equations. This solution depends continuously on
the driving rough path. This allows a robust approach to stochastic partial
differential equations. In particular, we may replace Brownian motion by more
general Gaussian and Markovian noise. Support theorems and large deviation
statements all became easy corollaries of the corresponding statements of the
driving process. In the case of first order equations with Gaussian noise, we
discuss the existence of a density with respect to the Lebesgue measure for the
solution.


title: Heat Conduction Process on Community Networks as a Recommendation Model

abstract:
  Using heat conduction mechanism on a social network we develop a systematic
method to predict missing values as recommendations. This method can treat very
large matrices that are typical of internet communities. In particular, with an
innovative, exact formulation that accommodates arbitrary boundary condition,
our method is easy to use in real applications. The performance is assessed by
comparing with traditional recommendation methods using real data.


title: On Singular Poisson Sternberg Spaces

abstract:
  We obtain a theory of stratified Sternberg spaces thereby extending the
theory of cotangent bundle reduction for free actions to the singular case
where the action on the base manifold consists of only one orbit type. We find
that the symplectic reduced spaces are stratified topological fiber bundles
over the cotangent bundle of the orbit space. We also obtain a Poisson
stratification of the Sternberg space. To construct the singular Poisson
Sternberg space we develop an appropriate theory of singular connections for
proper group actions on a single orbit type manifold including a theory of
holonomy extending the usual Ambrose-Singer theorem for principal bundles.


title: Laws of the single logarithm for delayed sums of random fields

abstract:
  We extend a law of the single logarithm for delayed sums by Lai to delayed
sums of random fields. A law for subsequences, which also includes the
one-dimensional case, is obtained in passing.


title: Soft X-ray spectroscopy of highly charged silicon ions in dense plasmas

abstract:
  Rich soft X-ray emission lines of highly charged silicon ions (Si VI--Si XII)
were observed by irradiating an ultra-intense laser pulse with width of 200 fs
and energy of $\sim$90 mJ on the solid silicon target. The high resolution
spectra of highly charged silicon ions with full-width at half maximum (FWHM)
of $\sim$0.3--0.4\AA is analyzed in wavelength range of 40--90 \AA . The
wavelengths of 53 prominent lines are determined with statistical uncertainties
being up to 0.005 \AA . Collisional-radiative models were constructed for Si VI
-- Si XII ions, which satisfactorily reproduces the experimental spectra, and
helps the line identification. Calculations at different electron densities
reveal that the spectra of dense plasmas are more complicate than the spectra
of thin plasmas. A comparison with the Kelly database reveals a good agreement
for most peak intensities, and differences for a few emission lines.


title:
A unified approach on Springer fibers in the hook, two-row and
  two-column cases

abstract:
  We consider the Springer fiber over a nilpotent endomorphism. Fix a Jordan
basis and consider the standard torus relative to this. We deal with the
problem to describe the flags fixed by the torus which belong to a given
component of the Springer fiber. We solve the problem in the hook, two-row and
two-column cases. We provide two main characterizations which are common to the
three cases, and which involve dominance relations between Young diagrams and
combinatorial algorithms. Then, for these three cases, we deduce topological
properties of the components and their intersections.


title: A tropical interpretation of m-dissimilarity maps

abstract:
  Let T be a weighted tree with n numbered leaves and let D be its distance
matrix, so D(i,j) is the distance between the leaves i and j. If m is an
integer between 2 and n, we prove a tropical formula to compute the
m-dissimilarity map of T (i.e. the weights of the subtrees of T with m leaves),
given D. For m equal to 3, we present a tropical description of the set of
m-dissimilarity maps of trees. For m equal to 4, a partial result is given.


title:
Soft X-ray Absorption and Photoemission Studies of Ferromagnetic
  Mn-Implanted 3$C$-SiC

abstract:
  We have performed x-ray photoemission spectroscopy (XPS), x-ray absorption
spectroscopy (XAS), and resonant photoemission spectroscopy (RPES) measurements
of Mn-implanted 3$C$-SiC (3$C$-SiC:Mn) and carbon-incorporated Mn$_{5}$Si$_{2}$
(Mn$_{5}$Si$_{2}$:C). The Mn 2$p$ core-level XPS and XAS spectra of 3$C$-SiC:Mn
and Mn$_{5}$Si$_{2}$:C were similar to each other and showed "intermediate"
behaviors between the localized and itinerant Mn 3$d$ states.
  The intensity at the Fermi level was found to be suppressed in 3$C$-SiC:Mn
compared with Mn$_{5}$Si$_{2}$:C. These observations are consistent with the
formation of Mn$_{5}$Si$_{2}$:C clusters in the 3$C$-SiC host, as observed in a
recent transmission electron microscopy study.


title: Systematic Analysis of Scaling Properties in Deep Inelastic Scattering

abstract:
  Using the ``Quality Factor'' (QF) method, we analyse the scaling properties
of deep-inelastic processes at HERA and fixed target experiments for x<0.01. We
look for scaling formulae of the form sigma(tau), where tau(log Q^2, Y) is a
scaling variable suggested by the asymptotic properties of QCD evolution
equations with rapidity Y. We consider four cases: ``Fixed Coupling'',
corresponding to the original geometric scaling proposal and motivated by the
asymptotic properties of the Balitsky-Kovchegov (BK) equation with fixed QCD
coupling constant, two versions ``Running Coupling I,II'' of the scaling
suggested by the BK equation with running coupling, and ``Diffusive Scaling''
suggested by the QCD evolution equation with Pomeron loops. The Quality
Factors, quantifying the phenomenological validity of the candidate scaling
variables, are fitted on the total and DVCS cross-section data from HERA and
predictions are made for the elastic vector-meson and for the diffractive
cross-sections at fixed small x_pom or beta. The first three scaling formulae
have comparably good QF while the fourth one is disfavored. Adjusting initial
conditions gives a significant improvement of the ``Running Coupling II''
scaling.


title:
Splitting of doubly quantized vortices in dilute Bose-Einstein
  condensates

abstract:
  We investigate the dynamics of doubly charged vortices generated in dilute
Bose-Einstein condensates by using the topological phase imprinting technique.
We find splitting times of such vortices and show that thermal atoms are
responsible for their decay.


title: Singular components of the Springer fiber in the two-columns case

abstract:
  We consider the Springer fiber ${\mathcal B}_u$ corresponding to a nilpotent
endomorphism $u$ of nilpotent order 2. As a first result, we give a description
of the elements of a given component of ${\mathcal B}_u$ which are fixed by the
action of the standard torus relative to some Jordan basis of $u$. By using
this result, we establish a necessary and sufficient condition of singularity
for the components of ${\mathcal B}_u$.


title:
Robust dynamic classes revealed by measuring the response function of a
  social system

abstract:
  We study the relaxation response of a social system after endogenous and
exogenous bursts of activity using the time-series of daily views for nearly 5
million videos on YouTube. We find that most activity can be described
accurately as a Poisson process. However, we also find hundreds of thousands of
examples in which a burst of activity is followed by an ubiquitous power-law
relaxation governing the timing of views. We find that these relaxation
exponents cluster into three distinct classes, and allow for the classification
of collective human dynamics. This is consistent with an epidemic model on a
social network containing two ingredients: A power law distribution of waiting
times between cause and action and an epidemic cascade of actions becoming the
cause of future actions. This model is a conceptual extension of the
fluctuation-dissipation theorem to social systems, and provides a unique
framework for the investigation of timing in complex systems.


title:
First principles molecular dynamics simulation of a task-specific ionic
  liquid based on silver-olefin complex: atomistic insight into separation
  process

abstract:
  This manuscript has been withdrawn by the authors, as requested by a journal
editor. Sorry for the inconvenience this may have caused you.


title:
Does there arise a significant enhancement of the dynamical quark mass
  in external magnetic field?

abstract:
  Recently, it was found in QED that the generation of a dynamical electron
mass in a strong magnetic field is significantly enhanced by the perturbative
electron mass. In the present paper, the related question of a possible
enhancement of the dynamical quark mass in an external magnetic field and with
a bare mass term is investigated in the Nambu--Jona-Lasinio model.


title: Modified Afshar Experiment: Calculations

abstract:
  The Afshar experiment is a relatively simple two-slit experiment with results
that appear to show a discrepancy with the predictions of Bohr's Principle of
Complementarity. We report on the results of a calculation using a simpler but
equivalent set-up called the modified Afshar experiment. Numerical results are
in agreement with the experimental results performed on the Afshar experiment
set-up. Calculations show that the level of which-way information and
visibility in the Afshar experiement is higher than originally estimated.


title:
Using acoustic waves to induce high-frequency current oscillations in
  superlattices

abstract:
  We show that GHz acoustic waves in semiconductor superlattices can induce THz
electron dynamics that depend critically on the wave amplitude. Below a
threshold amplitude, the acoustic wave drags electrons through the superlattice
with a peak drift velocity overshooting that produced by a static electric
field. In this regime, single electrons perform drifting orbits with THz
frequency components. When the wave amplitude exceeds the critical threshold,
an abrupt onset of Bloch-like oscillations causes negative differential
velocity. The acoustic wave also affects the collective behavior of the
electrons by causing the formation of localised electron accumulation and
depletion regions, which propagate through the superlattice, thereby producing
self-sustained current oscillations even for very small wave amplitudes. We
show that the underlying single-electron dynamics, in particular the transition
between the acoustic wave dragging and Bloch oscillation regimes, strongly
influence the spatial distribution of the electrons and the form of the current
oscillations. In particular, the amplitude of the current oscillations depends
non-monotonically on the strength of the acoustic wave, reflecting the
variation of the single-electron drift velocity.


title: Quasi-local mass in the covariant Newtonian space-time

abstract:
  In general relativity, quasi-local energy-momentum expressions have been
constructed from various formulae. However, Newtonian theory of gravity gives a
well known and an unique quasi-local mass expression (surface integration).
Since geometrical formulation of Newtonian gravity has been established in the
covariant Newtonian space-time, it provides a covariant approximation from
relativistic to Newtonian theories. By using this approximation, we calculate
Komar integral, Brown-York quasi-local energy and Dougan-Mason quasi-local mass
in the covariant Newtonian space-time. It turns out that Komar integral
naturally gives the Newtonian quasi-local mass expression, however, further
conditions (spherical symmetry) need to be made for Brown-York and Dougan-Mason
expressions.


title: A Measurement of Photon Production in Electron Avalanches in CF4

abstract:
  This paper presents a measurement of the ratio of photon to electron
production and the scintillation spectrum in a popular gas for time pro jection
chambers, carbon tetrafluoride (CF4), over the range of 200 to 800 nm; the
ratio is measured to be 0.34+/-0.04. This result is of particular importance
for a new generation of dark matter time projection chambers with directional
sensitivity which use CF4 as a fill gas.


title:
Correlations and order parameter at a Coulomb-crystal phase transition
  in a three-dimensional dimer model

abstract:
  The three-dimensional classical dimer model with interactions shows an
unexpected continuous phase transition between an ordered dimer crystal and a
Coulomb liquid. A detailed analysis of the critical dimer and monomer
correlation functions point to a subtle interplay between the fluctuations of
the crystal order parameter and the "magnetic" degrees of freedom present in
the Coulomb phase. The distribution probability of the crystal order parameter
suggests an emerging continuous O(3) symmetry at the critical point.


title:
Calculation of the conductance of a graphene sheet using the
  Chalker-Coddington network model

abstract:
  The Chalker-Coddington network model (introduced originally as a model for
percolation in the quantum Hall effect) is known to map onto the
two-dimensional Dirac equation. Here we show how the network model can be used
to solve a scattering problem in a weakly doped graphene sheet connected to
heavily doped electron reservoirs. We develop a numerical procedure to
calculate the scattering matrix with the aide of the network model. For
numerical purposes, the advantage of the network model over the honeycomb
lattice is that it eliminates intervalley scattering from the outset. We avoid
the need to include the heavily doped regions in the network model (which would
be computationally expensive), by means of an analytical relation between the
transfer matrix through the weakly doped region and the scattering matrix
between the electron reservoirs. We test the network algorithm by calculating
the conductance of an electrostatically defined quantum point contact and
comparing with the tight-binding model of graphene. We further calculate the
conductance of a graphene sheet in the presence of disorder in the regime where
intervalley scattering is suppressed. We find an increase in conductance that
is consistent with previous studies. Unlike the tight-binding model, the
network model does not require smooth potentials in order to avoid intervalley
scattering.


title:
On Agents' Agreement and Partial-Equilibrium Pricing in Incomplete
  Markets

abstract:
  We consider two risk-averse financial agents who negotiate the price of an
illiquid indivisible contingent claim in an incomplete semimartingale market
environment. Under the assumption that the agents are exponential utility
maximizers with non-traded random endowments, we provide necessary and
sufficient conditions for negotiation to be successful, i.e., for the trade to
occur. We also study the asymptotic case where the size of the claim is small
compared to the random endowments and we give a full characterization in this
case. Finally, we study a partial-equilibrium problem for a bundle of divisible
claims and establish existence and uniqueness. A number of technical results on
conditional indifference prices are provided.


title: Density scaling as a property of strongly correlating viscous liquids

abstract:
  We address a recent conjecture according to which the relaxation time $\tau$
of a viscous liquid obeys density scaling ($\tau=F(\rho^\gamma/T)$ where $\rho$
is density) if the liquid is ``strongly correlating,'' i.e., has almost 100%
correlation between equilibrium virial and potential-energy fluctuations
[Pedersen {\it et al.}, PRL {\bf 100}, 011201 (2008)]. Computer simulations of
two model liquids - an asymmetric dumbbell model and the Lewis-Wahnstr\"om OTP
model - confirm the conjecture and demonstrate that the scaling exponent
$\gamma$ can be accurately predicted from equilibrium fluctuations.


title: Estimates for periodic Zakharov-Shabat operators

abstract:
  We consider the periodic Zakharov-Shabat operators on the real line. The
spectrum of this operator consists of intervals separated by gaps with the
lengths $|g_n|\ge 0, n\in \Z$. Let $\m_n^\pm$ be the corresponding effective
masses and let $h_n$ be heights of the corresponding slits in the quasimomentum
domain. We obtain a priori estimates of sequences $g=(|g_n|)_{n\in
\Z},\m^\pm=(\m_n^\pm)_{n\in \Z}, h=(h_n)_{n\in \Z}$ in terms of weighted
$\ell^p-$norms at $p\ge 1$. The proof is based on the analysis of the
quasimomentum as the conformal mapping.


title: Microscopic Study Reveals the Singular Origins of Growth

abstract:
  P.W. Anderson proposed the concept of complexity in order to describe the
emergence and growth of macroscopic collective patterns out of the simple
interactions of many microscopic agents. In the physical sciences this paradigm
was implemented systematically and confirmed repeatedly by successful
confrontation with reality. In the social sciences however, the possibilities
to stage experiments to validate it are limited. During the 90's a series of
dramatic political and economic events have provided the opportunity to do so.
We exploit the resulting empirical evidence to validate a simple agent based
alternative to the classical logistic dynamics. The post-liberalization
empirical data from Poland confirm the theoretical prediction that the dynamics
is dominated by singular rare events which insure the resilience and
adaptability of the system. We have shown that growth is led by few singular
"growth centers" (Figure 1), that initially developed at a tremendous rate
(Figure3), followed by a diffusion process to the rest of the country and
leading to a positive growth rate uniform across the counties. In addition to
the interdisciplinary unifying potential of our generic formal approach, the
present work reveals the strong causal ties between the "softer" social
conditions and their "hard" economic consequences.


title: alpha-cluster states in intermediate mass nuclei

abstract:
  Properties of intermediate mass nuclei have been investigated within the
framework of the alpha-cluster model in combination with systematic
double-folding potentials. Previously, this alpha-cluster model has been widely
applied to light nuclei, in particular to 8Be = alpha \otimes alpha, 20Ne = 16O
\otimes alpha, and 44Ti = 40Ca \otimes alpha, and to heavy nuclei, in
particular to 212Po = 208Pb \otimes alpha. In the present work a wide range of
nuclei is investigated with the magic neutron number N = 50 in the mass range
around A \approx 80 - 100: (A+4,N=52) = (A,N=50) \otimes alpha. It is found
that excitation energies, decay properties, and transition strengths can be
described successfully within this model. The smooth and small variation of the
underlying parameters of the alpha-nucleus potential may be used for
extrapolations to predict experimentally unknown properties in the nuclei under
study.


title: From Ohmic to Ballistic Transport in Oriented Graphite

abstract:
  In this work we show that for a quasi-2D system of size $\Omega$ and
thickness $t$ the resistance goes as $(2\rho/\pi t)\ln(\Omega/W)$, diverging
logarithmically with the size. Measurements in highly oriented pyrolytic
graphite (HOPG) as well as numerical simulations confirm this relation.
Furthermore, we present an experimental method that allows us to obtain the
carriers mean free path $l(T)$, the Fermi wavelength $\lambda(T)$ and the
mobility $\mu(T)$ directly from experiments without adjustable parameters.
Measuring the electrical resistance through microfabricated constrictions in
HOPG and observing the transition from ohmic to ballistic regime we obtain that
$0.2 \mu$m $\lesssim l \lesssim 10 \mu$m, $0.1 \mu$m $\lesssim \lambda \lesssim
2 \mu$m and a mobility $5 \times 10^4$ cm$^2$/Vs $ \lesssim \mu \lesssim 4
\times 10^7$ cm$^2$/Vs when the temperature decreases from 270K to 3K. A
comparison of these results with those from literature indicates that
conventional, multiband Boltzmann-Drude approaches are inadequate for oriented
graphite. The upper value obtained for the mobility is much larger than the
mobility graphene samples of micrometer size can have.


title: A proof of the Faber intersection number conjecture

abstract:
  We prove the famous Faber intersection number conjecture and other more
general results by using a recursion formula of $n$-point functions for
intersection numbers on moduli spaces of curves. We also present some vanishing
properties of Gromov-Witten invariants.


title: When is a Bol loop Moufang?

abstract:
  There are a number of identities which, if satisfied by a Bol loop, imply
that the loop is actually Moufang. In this paper we show that in a number of
cases, the Moufang identity is also forced not by a single identity, but by
giving elements a choice of equations to satisfy.


title: The Cooper pair from radio-frequency excitations in ultracold gases

abstract:
  We discuss the concept of Cooper pair in the context of recent experimental
studies of radio-frequency excitations in ultracold atomic gases. We argue that
the threshold energy determines the size of the Cooper pair emergent from the
exact solution of the reduced BCS problem, and elaborate on the physical
distinction between bosonic and fermionic Cooper pairs.


title: MAD@VLT: Deep into the Madding Crowd of Omega Centauri

abstract:
  We present deep and accurate Near-Infrared (NIR) photometry of the Galactic
Globular Cluster (GC) Omega Cen. Data were collected using the Multi-Conjugate
Adaptive Optics Demonstrator (MAD) on VLT (ESO). The unprecedented quality of
the images provided the opportunity to perform accurate photometry in the
central crowded regions. Preliminary results indicate that the spread in age
among the different stellar populations in Omega Cen is limited.


title:
Double-exciton component of the cyclotron spin-flip mode in a quantum
  Hall ferromagnet

abstract:
  We report on the calculation of the cyclotron spin-flip excitation (CSFE) in
a spin-polarized quantum Hall system at unit filling. This mode has a
double-exciton component which contributes to the CSFE correlation energy but
can not be found by means of a mean field approach. The result is compared with
available experimental data.


title:
Upper bounds for the number of limit cycles of some planar polynomial
  differential systems

abstract:
  We give an effective method for controlling the maximum number of limit
cycles of some planar polynomial systems. It is based on a suitable choice of a
Dulac function and the application of the well-known Bendixson-Dulac Criterion
for multiple connected regions. The key point is a new approach to control the
sign of the functions involved in the criterion. The method is applied to
several examples.


title:
Local enrichment and its nonlocal consequences for victim-exploiter
  metapopulations

abstract:
  The stabilizing effects of local enrichment are revisited. Diffusively
coupled host-parasitoid and predator-prey metapopulations are shown to admit a
stable fixed point, limit cycle or stable torus with a rich bifurcation
structure. A linear toy model that yields many of the basic qualitative
features of this system is presented. The further nonlinear complications are
analyzed in the framework of the marginally stable Lotka-Volterra model, and
the continuous time analog of the unstable, host-parasitoid Nicholson-Bailey
model. The dependence of the results on the migration rate and level of spatial
variations is examined, and the possibility of "nonlocal" effect of enrichment,
where local enrichment induces stable oscillations at a distance, is studied. A
simple method for basic estimation of the relative importance of this effect in
experimental systems is presented and exemplified.


title: On Conditions for Convergence to Consensus

abstract:
  A new theorem on conditions for convergence to consensus of a multiagent
time-dependent time-discrete dynamical system is presented. The theorem is
build up on the notion of averaging maps. We compare this theorem to results by
Moreau (IEEE Transactions on Automatic Control, vol. 50, no. 2, 2005) about
set-valued Lyapunov theory and convergence under switching communication
topologies. We give examples that point out differences of approaches including
examples where Moreau's theorem is not applicable but ours is. Further on, we
give examples that demonstrate that the theory of convergence to consensus is
still not complete.


title: Conditioning Probabilistic Databases

abstract:
  Past research on probabilistic databases has studied the problem of answering
queries on a static database. Application scenarios of probabilistic databases
however often involve the conditioning of a database using additional
information in the form of new evidence. The conditioning problem is thus to
transform a probabilistic database of priors into a posterior probabilistic
database which is materialized for subsequent query processing or further
refinement. It turns out that the conditioning problem is closely related to
the problem of computing exact tuple confidence values.
  It is known that exact confidence computation is an NP-hard problem. This has
led researchers to consider approximation techniques for confidence
computation. However, neither conditioning nor exact confidence computation can
be solved using such techniques.
  In this paper we present efficient techniques for both problems. We study
several problem decomposition methods and heuristics that are based on the most
successful search techniques from constraint satisfaction, such as the
Davis-Putnam algorithm. We complement this with a thorough experimental
evaluation of the algorithms proposed. Our experiments show that our exact
algorithms scale well to realistic database sizes and can in some scenarios
compete with the most efficient previous approximation algorithms.


title: Automorphisms of Partially Commutative Groups I: Linear Subgroups

abstract:
  The goal of this paper is to construct and describe certain arithmetic
subgroups of the automorphism group of a partially commutative group. More
precisely, given an arbitrary finite graph $\Gamma$ we construct an arithmetic
subgroup $St(L(G))$, represented as a subgroup of $GL(n,Z)$, where $n$ is the
number of vertices of the graph $\Gamma$.
  In the last section of the paper we give a description of the decomposition
of the group of automorphisms $St^{conj}(L(G))$ as a semidirect product of the
group of conjugating automorphisms $Conj(G)$ and $St(L(G))$. This result is
closely related to Theorem 1.4 of the paper arXiv:0710.2573v1.


title: The Gauss Map of Hypersurfaces in 2-Step Nilpotent Lie Groups

abstract:
  In this paper we consider smooth oriented hypersurfaces in 2-step nilpotent
Lie groups with a left invariant metric and derive an expression for the
Laplacian of the Gauss map for such hypersurfaces in the general case and in
some particular cases. In the case of CMC-hypersurface in the
(2m+1)-dimensional Heisenberg group we also derive necessary and sufficient
conditions for the Gauss map to be harmonic and prove that for m=1 all
CMC-surfaces with the harmonic Gauss map are "cylinders".


title: Integral group ring of the Suzuki sporadic simple group

abstract:
  Using the Luthar--Passi method, we investigate the classical Zassenhaus
conjecture for the normalized unit group of the integral group ring of the
Suzuki sporadic simple group Suz. As a consequence, for this group we confirm
the Kimmerle's conjecture on prime graphs.


title: Low-lying Dirac eigenmodes and monopoles in 3+1D compact QED

abstract:
  We study the properties of low-lying Dirac modes in quenched compact QED at
$\beta =1.01$, employing $12^3\times N_t$ ($N_t =4,6,8,10,12$) lattices and the
overlap formalism for the fermion action. We pay attention to the spatial
distributions of low-lying Dirac modes below and above the ``phase transition
temperature'' $T_c$. Near-zero modes are found to have universal
anti-correlations with monopole currents, and are found to lose their temporal
structures above $T_c$ exhibiting stronger spatial localization properties. We
also study the nearest-neighbor level spacing distribution of Dirac eigenvalues
and find a Wigner-Poisson transition.


title:
A classification of the X-ray and radio states of Cyg X-3 and their
  long-term correlations

abstract:
  We present a detailed classification of the X-ray states of Cyg X-3 based on
the spectral shape and a new classification of the radio states based on the
long-term correlated behaviour of the radio and soft X-ray light curves. We
find a sequence of correlations, starting with a positive correlation between
the radio and soft X-ray fluxes in the hard spectral state, changing to a
negative one at the transition to soft spectral states. The temporal evolution
can be in either direction on that sequence, unless the source goes into a very
weak radio state, from which it can return only following a major radio flare.
The flare decline is via relatively bright radio states, which results in a
hysteresis loop on the flux-flux diagram. We also study the hard X-ray light
curve, and find its overall anticorrelation with the soft X-rays. During major
radio flares, the radio flux responds exponentially to the level of a hard
X-ray high-energy tail. We also specify the detailed correspondence between the
radio states and the X-ray spectral states. We compare our results to those of
black-hole and neutron-star binaries. Except for the effect of strong
absorption and the energy of the high-energy break in the hard state, the X-ray
spectral states of Cyg X-3 closely correspond to the canonical X-ray states of
black-hole binaries. Also, the radio/X-ray correlation closely corresponds to
that found in black-hole binaries, but it significantly differs from that in
neutron-star binaries. Overall, our results strongly support the presence of a
black hole in Cyg X-3.


title:
Forward-like functions for dual parametrization of GPDs from nonlocal
  chiral quark model

abstract:
  We derive the set of inversion relations allowing to establish the link
between the dual parametrization of GPDs and a broad class of phenomenological
models for GPDs. As an example we consider the results of the calculation of
the pion GPD in the framework of nonlocal chiral quark model (NlCQM) to recover
the set of forward-like functions representing this GPD in the framework of
dual parametrization. We also argue that Abel tomography method overlooks
possible delta function like contributions to GPD quintessence function making
explicit contribution to the D from factor.


title: Lighweight Target Tracking Using Passive Traces in Sensor Networks

abstract:
  We study the important problem of tracking moving targets in wireless sensor
networks. We try to overcome the limitations of standard state of the art
tracking methods based on continuous location tracking, i.e. the high energy
dissipation and communication overhead imposed by the active participation of
sensors in the tracking process and the low scalability, especially in sparse
networks. Instead, our approach uses sensors in a passive way: they just record
and judiciously spread information about observed target presence in their
vicinity; this information is then used by the (powerful) tracking agent to
locate the target by just following the traces left at sensors. Our protocol is
greedy, local, distributed, energy efficient and very successful, in the sense
that (as shown by extensive simulations) the tracking agent manages to quickly
locate and follow the target; also, we achieve good trade-offs between the
energy dissipation and latency.


title: The Anatomy of Mitos Web Search Engine

abstract:
  Engineering a Web search engine offering effective and efficient information
retrieval is a challenging task. This document presents our experiences from
designing and developing a Web search engine offering a wide spectrum of
functionalities and we report some interesting experimental results. A rather
peculiar design choice of the engine is that its index is based on a DBMS,
while some of the distinctive functionalities that are offered include advanced
Greek language stemming, real time result clustering, and advanced link
analysis techniques (also for spam page detection).


title: Submanifolds with the Harmonic Gauss Map in Lie Groups

abstract:
  In this paper we find a criterion for the Gauss map of an immersed smooth
submanifold in some Lie group with left invariant metric to be harmonic. Using
the obtained expression we prove some necessary and sufficient conditions for
the harmonicity of this map in the case of totally geodesic submanifolds in Lie
groups admitting biinvariant metrics. We show that, depending on the structure
of the tangent space of a submanifold, the Gauss map can be harmonic in all
biinvariant metrics or non-harmonic in some metric. For 2-step nilpotent groups
we prove that the Gauss map of a geodesic is harmonic if and only if it is
constant.


title:
Resonant heating and substrate-mediated cooling of a single C60 molecule
  in a tunnel junction

abstract:
  We study the influence of different metallic substrates on the electron
induced heating and heat dissipation of single C60 molecules in the junction of
a low temperature scanning tunneling microscope. The electron current passing
through the molecule produces a large amount of heat due to electron-phonon
coupling, eventually leading to thermal decomposition of the fullerene cage.
The power for decomposition varies with electron energy and reflects the
resonance structure participating in the transport. The average value for
thermal decomposition of C60 on Cu(110) amounts to 21 $\mu$W, while it is much
lower on Pb(111) (2.9 $\mu$W) and on Au(111) (1.0 $\mu$W). We ascribe this
difference to the amount of charge transfer into C60 upon adsorption on the
different surfaces, which facilitates molecular vibron quenching by
electron-hole pair creation.


title: Duality of Chordal SLE, II

abstract:
  We improve the geometric properties of SLE$(\kappa;\vec{\rho})$ processes
derived in an earlier paper, which are then used to obtain more results about
the duality of SLE. We find that for $\kappa\in (4,8)$, the boundary of a
standard chordal SLE$(\kappa)$ hull stopped on swallowing a fixed
$x\in\R\sem\{0\}$ is the image of some SLE$(16/\kappa;\vec{\rho})$ trace
started from a random point. Using this fact together with a similar
proposition in the case that $\kappa\ge 8$, we obtain a description of the
boundary of a standard chordal SLE$(\kappa)$ hull for $\kappa>4$, at a finite
stopping time. Finally, we prove that for $\kappa>4$, in many cases, the limit
of a chordal or strip SLE$(\kappa;\vec{\rho})$ trace exists.


title: Hadro-Charmonium

abstract:
  We argue that relatively compact charmonium states, $J/\psi$, $\psi(2S)$,
$\chi_c$, can very likely be bound inside light hadronic matter, in particular
inside higher resonances made from light quarks and/or gluons. The charmonium
state in such binding essentially retains its properties, so that the bound
system decays into light mesons and the particular charmonium resonance. Thus
such bound states of a new type, which we call hadro-charmonium, may explain
the properties of some of the recently observed resonant peaks, in particular
of Y(4.26), Y(4.32-4.36), Y(4.66), and Z(4.43). We discuss further possible
implications of the suggested picture for the observed states and existence of
other states of hadro-charmonium and hadro-bottomonium.


title:
The Kinematic Properties of the Extended Disks of Spiral Galaxies: A
  Sample of Edge-On Galaxies

abstract:
  We present a kinematic study of the outer regions (R_25<R<2 R_25) of 17
edge-on disk galaxies. Using deep long-slit spectroscopy (flux sensitivity a
few 10^-19 erg s^-1 cm^-2 arcsec^-2), we search for H-alpha emission, which
must be emitted at these flux levels by any accumulation of hydrogen due to the
presence of the extragalactic UV background and any other, local source of UV
flux. We present results from the individual galaxy spectra and a stacked
composite. We detect H-alpha in many cases well beyond R_25 and sometimes as
far as 2 R_25. The combination of sensitivity, spatial resolution, and
kinematic resolution of this technique thus provides a powerful complement to
21-cm observations. Kinematics in the outer disk are generally disk-like (flat
rotation curves, small velocity dispersions) at all radii, and there is no
evidence for a change in the velocity dispersion with radius. We place strong
limits, few percent, on the existence of counter-rotating gas out to 1.5 R_25.
These results suggest that thin disks extend well beyond R_25; however, we also
find a few puzzling anomalies. In ESO 323-G033 we find two emission regions
that have velocities close to the systemic velocity rather than the expected
rotation velocity. These low relative velocities are unlikely to be simply due
to projection effects and so suggest that these regions are not on disk-plane,
circular orbits. In MCG-01-31-002 we find emission from gas with a large
velocity dispersion that is co-rotating with the inner disk.


title: Unique solutions to boundary value problems in the cold plasma model

abstract:
  The unique existence of a weak solution to the homogeneous closed Dirichlet
problem on certain D-star-shaped domains is proven for a mixed
elliptic-hyperbolic equation. Equations of this kind arise in models for
electromagnetic wave propagation in cold plasma. A related class of open
boundary value problems is shown to possess strong solutions.


title:
A decomposition of the bifractional Brownian motion and some
  applications

abstract:
  In this paper we show a decomposition of the bifractional Brownian motion
with parameters H,K into the sum of a fractional Brownian motion with Hurst
parameter HK plus a stochastic process with absolutely continuous trajectories.
Some applications of this decomposition are discussed.


title: Lorentz Violation and Torsion

abstract:
  In this proceedings, similarities between the structure of theories with
Lorentz violation and theories with constant torsion in flat spacetime are
exploited to place bounds on torsion components. An example is given showing
the analysis leading to bounds on the axial-vector and mixed-symmetry
components of torsion, based on a dual-maser experiment.


title:
Understanding the 8 micron vs. Pa-alpha relationship on sub-arcsecond
  scales in Luminous Infrared Galaxies

abstract:
  This work explores in detail the relation between the 8 micron and the
Pa-alpha emissions for 122 HII regions identified in a sample of 10 low-z LIRGs
with nearly constant metallicity (12 + log (O/H) ~ 8.8). We use Gemini/T-ReCS
high-spatial resolution (<~ 0.4" ~ 120 pc for the average distance of 60 Mpc of
our sample) mid-infrared imaging (at 8.7 micron or 10.3 micron) together with
HST/NICMOS continuum and Pa-alpha images. The LIRG HII regions extend the
L_8micron vs. L_Pa-alpha relation found for HII knots in the high-metallicity
SINGS galaxies by about two orders of magnitude to higher luminosities. Since
the metallicity of the LIRG sample is nearly constant, we can rule out this
effect as a cause for the scatter seen in the relationship. In turn, it is
attributed to two effects: age and PAH features. The L_8micron/L_Pa-alpha
ratio, which varies by a factor of ten for the LIRG HII regions, is reproduced
by a model with instantaneous star formation and ages ranging from ~ 4 to 7.5
Myr. The remaining dispersion around the model predictions for a given age is
probably due to differential contributions of the PAH features (the 8.6 micron,
in our case) to the 8 micron emission from galaxy to galaxy.


title: An atomic mechanism for the boson peak in metallic glasses

abstract:
  The boson peak in metallic glasses is modeled in terms of local structural
shear rearrangements. Using Eshelby's solution of the corresponding elasticity
theory problem (J. D. Eshelby, Proc. Roy. Soc. A241, 376 (1957)), one can
calculate the saddle point energy of such a structural rearrangement. The
neighbourhood of the saddle point gives rise to soft resonant vibrational
modes. One can calculate their density, their kinetic energy, their fourth
order potential term and their coupling to longitudinal and transverse sound
waves.


title:
TeVJet: A general framework for the calculation of jet observables in
  NLO QCD

abstract:
  In this paper we present the parton level Monte Carlo program TeVJet, a
direct implementation of the dipole subtraction method for calculating jet
cross sections in NLO QCD. It has been written so as to allow the inclusion of
new processes in as straightforward a way as possible. The user must provide
the usual ingredients for an NLO calculation and from these the
process-independent parts required to make the phase space integrals finite in
4 dimensions are automatically generated. These integrals are then performed
using Monte Carlo techniques. We present the results for a few example
processes.


title: A high-sensitivity 6.7 GHz methanol maser survey toward H2O sources

abstract:
  We present the results of a high sensitivity survey for 6.7 GHz methanol
masers towards 22 GHz water maser using the 100 m Efflesberg telescope. A total
of 89 sources were observed and 10 new methanol masers were detected. The new
detections are relatively faint with peak flux densities between 0.5 and 4.0
Jy. A nil detection rate from low-mass star forming regions enhances the
conclusion that the masers are only associated with massive star formation.
Even the faintest methanol maser in our survey, with a luminosity of 1.1
$10^{-9} L_\odot$ is associated with massive stars as inferred from its
infrared luminosity.


title:
Magnetoelectric effect in mixed valency oxides mediated by charge
  carriers

abstract:
  We show that the presence of free carriers in a substance can generate the
multiferroic behavior. Namely, if the substance has mixed-valence ions, which
can supply free carriers and have electric dipole and spin moments, all three
types of long-range order (ferromagnetic, ferroelectric and magnetoelectric
(ME)) can occur at low temperature. The physical origin of the effect is that
charge carriers can mediate the multiferroic behavior via spin - spin (RKKY),
dipole-dipole and dipole - spin interactions. Our estimate of the interaction
magnitude shows that there exist an optimal carrier concentration, at which the
strength of ME interaction is maximal and comparable to that of spin-spin RKKY
interaction. This permits to conclude that in substances, where RKKY
interaction between local spins is not small, a substantial value of free
carriers mediated ME interaction can occur. Our analysis shows that disorder in
the above substances does not suppress multiferroic effects.


title:
Lensing Probabilities for Spectroscopically Selected Galaxy-Galaxy
  Strong Lenses

abstract:
  Spectroscopic galaxy-galaxy lens searches are presently the most prolific
method of identifying strong lens systems in large data sets. We study the
probabilities associated with these lens searches, namely the probability of
identifying a candidate with rogue [OII] emission lines in a galaxy's spectrum,
and the probability that the candidate will show features of strong lensing in
follow-up photometric observations. We include selection effects unique to
spectroscopic data, and apply them to the Sloan Lens ACS (SLACS) survey (Bolton
et al. 2006). The most significant selection effect is the finite size of the
spectroscopic fiber which selects against large separation lenses and results
in a non-monotonic dependence of the rogue line probability on velocity
dispersion. For example, with the 3 arcsec diameter SDSS fiber and 2 arcsec
FWHM seeing, we find that the probability that a given LRG has a rogue [OII]
line in its spectrum decreases with velocity dispersion from 150 km/s to 300
km/s and then increases up to 400 km/s for a given source size. The total
probability for observing a rogue line in a single survey spectrum is
~0.9-3.0%, and the total lensing rate is ~0.5-1.3%. The range is due to
uncertainties in the physical size of [OII] emission regions, and in the
evolution of the [OII] luminosity function. Our estimates are a factor of ~5
higher than the results of the SLACS survey, a discrepancy which we attribute
to the SLACS requirement that multiple rogue lines be observed simultaneously.


title: On the distribution of stellar masses in gamma-ray burst host galaxies

abstract:
  We analyse Spitzer images of 30 long-duration gamma-ray burst (GRB) host
galaxies. We estimate their total stellar masses (M*) based on the rest-frame
K-band luminosities (L_Krest) and constrain their star formation rates (SFRs,
not corrected for dust extinction) based on the rest-frame UV continua.
Further, we compute a mean M*/L_Krest = 0.45 Msun/Lsun. We find that the hosts
are low M*, star-forming systems. The median M* in our sample (<M*> = 10^9.7
Msun) is lower than that of "field" galaxies (e.g., Gemini Deep Deep Survey).
The range spanned by M* is 10^7 Msun < M* < 10^11 Msun, while the range spanned
by the dust-uncorrected UV SFR is 10^-2 Msun yr^-1 < SFR < 10 Msun yr^-1. There
is no evidence for intrinsic evolution in the distribution of M* with redshift.
We show that extinction by dust must be present in at least 25% of the GRB
hosts in our sample and suggest that this is a way to reconcile our finding of
a relatively lower UV-based, specific SFR (PHI = SFR/M*) with previous claims
that GRBs have some of the highest PHI values. We also examine the effect that
the inability to resolve the star-forming regions in the hosts has on PHI.


title: Next Generation Redshift Surveys and the Origin of Cosmic Acceleration

abstract:
  Cosmologists are exploring two possible sets of explanations for the
remarkable observation of cosmic acceleration: dark energy fills space or
general relativity fails on cosmological scales. We define a null test
parameter $\epsilon(k,a) \equiv\Omega_m^{- \gamma} d \ln D / d \ln a - 1$,
where $a$ is the scale factor, $D$ is the growth rate of structure,
$\Omega_m(a)$ is the matter density parameter, and $\gamma$ is a simple
function of redshift.
  We show that it can be expressed entirely in terms of the bias factor,
$b(a)$, (measured from cross-correlations with CMB lensing) and the amplitude
of redshift space distortions, $\beta(k,a)$. Measurements of the CMB power
spectrum determine $\Omega_{m 0} H_0^2$. If dark energy within GR is the
solution to the cosmic acceleration problem, then the logarithmic growth rate
of structure $d \ln D / d \ln a = \Omega_m^\gamma$. Thus, $\epsilon(k,a) =0$ on
linear scales to better than 1%. We show that in the class of Modified Gravity
models known as $f(R)$, the growth rate has a different dependence on scale and
redshift.
  By combining measurements of the amplitude of $\beta$ and of the bias, $b$,
redshift surveys will be able to determine the logarithmic growth rate as a
function of scale and redshift. We estimate the predicted sensitivity of the
proposed SDSS III (BOSS) survey and the proposed ADEPT mission and find that
they will test structure growth in General Relativity to the percent level.


title: The First Galaxies: Assembly, Cooling and the Onset of Turbulence

abstract:
  We investigate the properties of the first galaxies at z > 10 with highly
resolved numerical simulations, starting from cosmological initial conditions
and taking into account all relevant primordial chemistry and cooling. A first
galaxy is characterized by the onset of atomic hydrogen cooling, once the
virial temperature exceeds 10^4 K, and its ability to retain photoheated gas.
We follow the complex accretion and star formation history of a 5*10^7 M_sun
system by means of a detailed merger tree and derive an upper limit on the
number of Population III (Pop III) stars formed prior to its assembly. We
investigate the thermal and chemical evolution of infalling gas and find that
partial ionization at temperatures > 10^4 K catalyses the formation of H2 and
hydrogen deuteride, allowing the gas to cool to the temperature of the cosmic
microwave background. Depending on the strength of radiative and chemical
feedback, primordial star formation might be dominated by intermediate-mass Pop
III stars formed during the assembly of the first galaxies. Accretion on to the
nascent galaxy begins with hot accretion, where gas is accreted directly from
the intergalactic medium and shock-heated to the virial temperature, but is
quickly accompanied by a phase of cold accretion, where the gas cools in
filaments before flowing into the parent halo with high velocities. The latter
drives supersonic turbulence at the centre of the galaxy and could lead to very
efficient chemical mixing. The onset of turbulence in the first galaxies thus
likely marks the transition to Pop II star formation.


title:
Detectability of a phantom-like braneworld model with the integrated
  Sachs-Wolfe effect

abstract:
  We study a braneworld model in which a phantom-like behaviour occurs with
only cold dark matter and a cosmological constant, due to a large distance
modification of gravity. With the addition of curvature, the geometrical tests
are not strict enough to rule out models in which gravity is modified
significantly on large scales. We show that this degeneracy in the parameter
space is broken by the structure formation tests, such as the integrated
Sachs-Wolfe effect, which can probe general relativity on large scales.


title:
The integrated Sachs-Wolfe effect in cosmologies with coupled dark
  matter and dark energy

abstract:
  The subject of this paper is the derivation of the integrated Sachs-Wolfe
(iSW) effect in cosmologies with coupled dark matter and dark energy fluids.
These couplings influence the iSW-effect in three ways: The Hubble function
assumes a different scaling, the structure growth rate shows a different time
evolution, and in addition, the Poisson equation, which relates the density
perturbations to fluctuations in the gravitational potential, is changed, due
to the violation of the scaling rho ~ a^{-3} of the matter density rho with
scale factor a. Exemplarily, I derive the iSW-spectra for a model in which dark
matter decays into dark energy, investigate the influence of the dark matter
decay rate and the dark energy equation of state on the iSW-signal, and discuss
the analogies for gravitational lensing. Quite generally iSW-measurements
should reach similar accuracy in determining the dark energy equation of state
parameter and the coupling constant.


title: The Exo-planetary System of 55 Cancri and the Titius-Bode Law

abstract:
  The recent discovery of a fifth planet bound to 55 Cancri (Fischer et. al
2007) motivated us to investigate if this exo-planetary system fits some form
of the Titius-Bode (TB) law. We found that a simple exponential TB relation
reproduces very well the five observed major semi-axis, provided we assign the
orbital n = 6 to the largest a. This way of counting leaves empty the position
n = 5, a situation curiously reminiscent of TB law in our planetary system,
before the discovery of Ceres. The application of an exponential TB relation to
55 Cancri allows us to predict the existence of a planet at a = 2.0 AU with a
period of P = 1130 days located within the large gap between a = 0.781 AU (P =
260 days) and a = 5.77 AU (P = 5218 days). With less certainty, we also predict
a seventh planet at a = 15 AU with P = 62 years.


title: Comment on "on a new definition of quantum entropy"

abstract:
  In the article, on a new definition of quantum entropy, Campisi has explained
an operator for entropy based on quantum number operator. It has been claimed
that the expectation values for this operator increases for every
non-quasi-static time dependent perturbations. We have found an example for a
case that entropy with this definition does not increase through a spontaneous
process.


title:
New exact solutions on the Randall-Sundrum 2-brane: lumps of dark
  radiation and accelerated black holes

abstract:
  We provide the most general embedding of a purely tensional 2-brane in a 3+1
dimensional bulk described by the AdS C-metric. The AdS C-metric has been first
considered as bulk metric by Emparan, Horowitz and Myers (hep-th/9911043 and
hep-th/9912135), who have found metrics describing a brane localized black
hole. In those papers, one of the parameters of the bulk C-metric was
fine-tuned to the brane tension. We relax this fine tuning and we find two new
classes of solutions, the first describing a time dependent, rotationally
symmetric metric, the second describing accelerated black holes on the brane.
This is the first exact solution on the brane describing two objects in
interaction. We discuss the qualitative CFT interpretation of these solutions.


title: Fidelity analysis of topological quantum phase transitions

abstract:
  We apply the fidelity metric approach to analyze two recently introduced
models that exhibit a quantum phase transition to a topologically ordered
phase. These quantum models have a known connection to classical statistical
mechanical models; we exploit this mapping to obtain the scaling of the
fidelity metric tensor near criticality. The topological phase transitions
manifest themselves in divergences of the fidelity metric across the phase
boundaries. These results provide evidence that the fidelity approach is a
valuable tool to investigate novel phases lacking a clear characterization in
terms of local order parameters.


title: Vertical Ends of Constant Mean Curvature H=1/2 in H^2\times R

abstract:
  We prove a vertical halfspace theorem for surfaces with constant mean
curvature $H={1/2},$ properly immersed in the product space $\h^2\times\re,$
where $\h^2$ is the hyperbolic plane and $\re$ is the set of real numbers. The
proof is a geometric application of the classical maximum principle for second
order elliptic PDE, using the family of non compact rotational $H=1/2$ surfaces
in $\h^2\times\re.$


title:
Remarks on Nehari's problem, matrix $A_2$ condition, and weighted
  bounded mean oscillation

abstract:
  We consider Nehari's problem in the case of non-uniqueness of solution. The
solution set is then parametrized by the unit ball of $H^{\infty}$ by means of
so-called {\em regular generators} -- bounded holomorphic functions $\phi$. The
definition of {\em regularity} is given below, but let us mention now that 1)
the following assumption on modulus of $\phi$ is sufficient for {\em
regularity}: $\frac{1}{1-|\phi|^2}\in L^1(\mathbb{T})$; 2) there is no
necessary and sufficient condition of {\em regularity} on bounded holomorphic
$\phi$ in terms of $|\phi|$ on $\mathbb{T}$, \cite{Kh1}. This makes reasonable
the attempt to find a weaker sufficient condition on $|\phi|$ than the
condition in 1). This is done here. Also we are discussing certain new
necessary and sufficient conditions of {\em regularity} in terms of bounded
mean (weighted) oscillations of $\phi$. They involve the matrix $A_2$ condition
from \cite{TV}.


title: Charged Fermions Tunnelling from Kerr-Newman Black Holes

abstract:
  We consider the tunnelling of charged spin-(1/2) fermions from a Kerr-Newman
black hole and demonstrate that the expected Hawking temperature is recovered.
We discuss certain technical subtleties related to the obtention of this
result.


title:
Monge--Amp\`ere equation and Bellman optimization of Carleson Embedding
  Theorems

abstract:
  Monge--Amp\`ere equation plays an important part in Analysis. For example, it
is instrumental in mass transport problems. On the other hand, the Bellman
function technique appeared recently as a way to consider certain Harmonic
Analysis problems as the problems of Stochastic Optimal Control. This brings us
to Bellman PDE, which in stochastic setting is often a Monge--Amp\`ere equation
or its close relative. We explore the way of solving Monge--Amp\`ere equation
by a sort of method of characteristics to find the Bellman function of certain
classical Harmonic Analysis problems, and, therefore, of finding full structure
of sharp constants and extremal sequences for those problems.


title:
Perturbation of multiparameter non-self-adjoint boundary eigenvalue
  problems for operator matrices

abstract:
  We consider two-point non-self-adjoint boundary eigenvalue problems for
linear matrix differential operators. The coefficient matrices in the
differential expressions and the matrix boundary conditions are assumed to
depend analytically on the complex spectral parameter and on the vector of real
physical parameters. We study perturbations of semi-simple multiple eigenvalues
as well as perturbations of non-derogatory eigenvalues under small variations
of the parameters. Explicit formulae describing the bifurcation of the
eigenvalues are derived. Application to the problem of excitation of unstable
modes in rotating continua such as spherically symmetric MHD alpha2-dynamo and
circular string demonstrates the efficiency and applicability of the theory.

categories: math-ph astro-ph math.MP physics.flu-dyn physics.plasm-ph


title: Crossed interval groups and operations on the Hochschild cohomology

abstract:
  We prove that the operad B of natural operations on the Hochschild cohomology
has the homotopy type of the operad of singular chains on the little disks
operad. To achieve this goal, we introduce crossed interval groups and show
that B is a certain crossed interval extension of an operad T whose homotopy
type is known. This completes the investigation of the algebraic structure on
the Hochschild cochain complex that has lasted for several decades.


title: On Halo Formation Times and Assembly Bias

abstract:
  In this paper we use the ``Millennium Simulation'' to re-examine the mass
assembly history of dark matter halos and the age dependence of halo
clustering. We use eight different definitions of halo formation times to
characterize the different aspects of the assembly history of a dark matter
halo. We find that these formation times have different dependence on halo
mass. While some formation times characterize well the hierarchical nature of
halo formation, in the sense that more massive halos have later formation, the
trend is reversed for other definitions of the formation time. In particular,
the formation times that are likely to be related to the formation of galaxies
in dark halos show strong trends of ``down-sizing'', in that lower-mass halos
form later. We also investigate how the correlation amplitude of dark matter
halos depends on the different formation times. We find that this dependence is
quite strong for some definitions of formation time but weak or absent for
other definitions. In particular, the correlation amplitude of halos of a given
mass is almost independent of their last major merger time. For the definitions
that are expected to be more related to the formation of galaxies in dark
halos, a significant assembly bias is found only for halos less massive than
M_*. We discuss our results in connection to the hierarchical assembly of dark
matter halos, the ``archaeological down-sizing'' observed in the galaxy
population, and the observed color-dependence of the clustering strength of
galaxy groups and clusters.


title: Resonant scattering and recombination of pseudo-degenerate WIMPs

abstract:
  We consider the direct and indirect detection signatures of WIMPs \chi^0 in
kinematic regimes with a heavier, but nearly degenerate, charged state
\chi^{+-}. For small splittings of O(10) MeV, the scattering of WIMPs off
nuclei may be dominated by inelastic recombination processes mediated by the
formation of (\chi^- N) bound states, leading to a distinct signature for
direct detection. These cross-sections are bound primarily by limits on the
abundance of heavy isotopes, and may be considerably larger than the elastic
scattering cross section in more conventional models. If the mass splitting is
too large for recombination to occur, there may still be a significant resonant
enhancement of loop-induced electromagnetic form-factors of the WIMP, which can
enhance the elastic scattering cross-section. We also discuss how this regime
affects the annihilation cross-section and indirect detection signatures, and
note the possibility of a significant mono-energetic \gamma-signal, mediated by
resonant processes near the (\chi^+\chi^-) bound state threshold.


title: Resonant forcing of nonlinear systems of differential equations

abstract:
  We study resonances of nonlinear systems of differential equations, including
but not limited to the equations of motion of a particle moving in a potential.
We use the calculus of variations to determine the minimal additive forcing
function that induces a desired terminal response, such as an energy in the
case of a physical system. We include the additional constraint that only
select degrees of freedom be forced, corresponding to a very general class of
problems in which not all of the degrees of freedom in an experimental system
are accessible to forcing. We find that certain Lagrange multipliers take on a
fundamental physical role as the effective forcing experienced by the degrees
of freedom which are not forced directly. Furthermore, we find that the product
of the displacement of nearby trajectories and the effective total forcing
function is a conserved quantity. We demonstrate the efficacy of this
methodology with several examples.


title: Diagonal vectors of shifted Young tableaux

abstract:
  We study vectors formed by entries on the diagonal of standard Young tableaux
of shifted shapes. Such vectors are in bijection with integer lattice points of
certain integral polytopes, which are Minkowski sums of simplices. We also
describe vertices of these polytopes, and construct corresponding shifted Young
tableaux.


title: Magnetoresistance and spin-transfer torque in magnetic tunnel junctions

abstract:
  We comment on both recent progress and lingering puzzles related to research
on magnetic tunnel junctions (MTJs). MTJs are already being used in
applications such as magnetic-field sensors in the read heads of disk drives,
and they may also be the first device geometry in which spin-torque effects are
applied to manipulate magnetic dynamics, in order to make nonvolatile magnetic
random access memory. However, there remain many unanswered questions about
such basic properties as the magnetoresistance of MTJs, how their properties
change as a function of tunnel-barrier thickness and applied bias, and what are
the magnitude and direction of the spin-transfer-torque vector induced by a
tunnel current.


title:
Might Carbon-Atmosphere White Dwarfs Harbour a New Type of Pulsating
  Star?

abstract:
  In the light of the recent and unexpected discovery of a brand new type of
white dwarfs, those with carbon-dominated atmospheres, we examine the
asteroseismological potential of such stars. The motivation behind this is
based on the observation that past models of carbon-atmosphere white dwarfs
have partially ionized outer layers that bear strong resemblance with those
responsible for mode excitation in models of pulsating DB (helium-atmosphere)
and pulsating DA (hydrogen-atmosphere) white dwarfs. Our exciting main result
is that, given the right location in parameter space, some carbon-atmosphere
white dwarfs are predicted to show pulsational instability against gravity
modes. We are eagerly waiting the results of observational searches for
luminosity variations in these stars.


title: Heavy-Tailed Distribution of Cyber-Risks

abstract:
  With the development of the Internet, new kinds of massive epidemics,
distributed attacks, virtual conflicts and criminality have emerged. We present
a study of some striking statistical properties of cyber-risks that quantify
the distribution and time evolution of information risks on the Internet, to
understand their mechanisms, and create opportunities to mitigate, control,
predict and insure them at a global scale. First, we report an exceptionnaly
stable power-law tail distribution of personal identity losses per event, ${\rm
Pr}({\rm ID loss} \geq V) \sim 1/V^b$, with $b =0.7 \pm 0.1$. This result is
robust against a surprising strong non-stationary growth of ID losses
culminating in July 2006 followed by a more stationary phase. Moreover, this
distribution is identical for different types and sizes of targeted
organizations. Since $b<1$, the cumulative number of all losses over all events
up to time $t$ increases faster-than-linear with time according to
$\mathbf{\simeq t^{1/b}}$, suggesting that privacy, characterized by personal
identities, is necessarily becoming more and more insecure. We also show the
existence of a size effect, such that the largest possible ID losses per event
grow faster-than-linearly as $\sim S^{1.3}$ with the organization size $S$. The
small value $b \simeq 0.7$ of the power law distribution of ID losses is
explained by the interplay between Zipf's law and the size effect. We also
infer that compromised entities exhibit basically the same probability to incur
a small or large loss.


title: High-Resolution Radar via Compressed Sensing

abstract:
  A stylized compressed sensing radar is proposed in which the time-frequency
plane is discretized into an N by N grid. Assuming the number of targets K is
small (i.e., K much less than N^2), then we can transmit a sufficiently
"incoherent" pulse and employ the techniques of compressed sensing to
reconstruct the target scene. A theoretical upper bound on the sparsity K is
presented. Numerical simulations verify that even better performance can be
achieved in practice. This novel compressed sensing approach offers great
potential for better resolution over classical radar.


title: Some insights from total collapse

abstract:
  We discuss the Sundman-Weierstrass theorem of total collapse in its
historical context. This remarkable and relatively simple result, a type of
stability criterion, is at the crossroads of some interesting developments in
the gravitation Newtonian N-body problem. We use it as motivation to explore
the connections to such important concepts as integrability, singularities and
tyipicality in order to gain some insight on the transition from a
predominantly quantitative to a novel qualitative approach to dynamical
problems that took place at the end of the 19th century.


title:
Measurement of the ratio of the $p\bar{p}\to W$+$c$-jet cross section to
  the inclusive $p\bar{p}\to W$+jets cross section

abstract:
  We present a measurement of the fraction of inclusive $W$+jets events
produced with net charm quantum number $\pm1$, denoted $W$+$c$-jet, in
$p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using approximately 1~fb$^{-1}$ of
data collected by the D0 detector at the Fermilab Tevatron Collider. We
identify the $W$+jets events via the leptonic $W$ boson decays. Candidate
$W$+$c$-jet events are selected by requiring a jet containing a muon in
association with a reconstructed $W$ boson and exploiting the charge
correlation between this muon and $W$ boson decay lepton to perform a nearly
model-independent background subtraction. We measure the fraction of
$W$+$c$-jet events in the inclusive $W$+jets sample for jet $p_{T}>20$ GeV and
pseudorapidity $|\eta|<2.5$ to be
0.074$\pm0.019$(stat.)$\pm^{0.012}_{0.014}$(syst.), in agreement with
theoretical predictions. The probability that background fluctuations could
produce the observed fraction of $W$+$c$-jet events is estimated to be
$2.5\times 10^{-4}$, which corresponds to a 3.5 $\sigma$ statistical
significance.


title:
Refined Topological Vertex, Cylindric Partitions and the U(1) Adjoint
  Theory

abstract:
  We study the partition function of the compactified 5D U(1) gauge theory (in
the Omega-background) with a single adjoint hypermultiplet, calculated using
the refined topological vertex. We show that this partition function is an
example a periodic Schur process and is a refinement of the generating function
of cylindric plane partitions. The size of the cylinder is given by the mass of
adjoint hypermultiplet and the parameters of the Omega-background. We also show
that this partition function can be written as a trace of operators which are
generalizations of vertex operators studied by Carlsson and Okounkov. In the
last part of the paper we describe a way to obtain (q,t) identities using the
refined topological vertex.


title:
Fourier Analysis of Gapped Time Series: Improved Estimates of Solar and
  Stellar Oscillation Parameters

abstract:
  Quantitative helio- and asteroseismology require very precise measurements of
the frequencies, amplitudes, and lifetimes of the global modes of stellar
oscillation. It is common knowledge that the precision of these measurements
depends on the total length (T), quality, and completeness of the observations.
Except in a few simple cases, the effect of gaps in the data on measurement
precision is poorly understood, in particular in Fourier space where the
convolution of the observable with the observation window introduces
correlations between different frequencies. Here we describe and implement a
rather general method to retrieve maximum likelihood estimates of the
oscillation parameters, taking into account the proper statistics of the
observations. Our fitting method applies in complex Fourier space and exploits
the phase information. We consider both solar-like stochastic oscillations and
long-lived harmonic oscillations, plus random noise. Using numerical
simulations, we demonstrate the existence of cases for which our improved
fitting method is less biased and has a greater precision than when the
frequency correlations are ignored. This is especially true of low
signal-to-noise solar-like oscillations. For example, we discuss a case where
the precision on the mode frequency estimate is increased by a factor of five,
for a duty cycle of 15%. In the case of long-lived sinusoidal oscillations, a
proper treatment of the frequency correlations does not provide any significant
improvement; nevertheless we confirm that the mode frequency can be measured
from gapped data at a much better precision than the 1/T Rayleigh resolution.


title: Constant-Rank Codes and Their Connection to Constant-Dimension Codes

abstract:
  Constant-dimension codes have recently received attention due to their
significance to error control in noncoherent random linear network coding. What
the maximal cardinality of any constant-dimension code with finite dimension
and minimum distance is and how to construct the optimal constant-dimension
code (or codes) that achieves the maximal cardinality both remain open research
problems. In this paper, we introduce a new approach to solving these two
problems. We first establish a connection between constant-rank codes and
constant-dimension codes. Via this connection, we show that optimal
constant-dimension codes correspond to optimal constant-rank codes over
matrices with sufficiently many rows. As such, the two aforementioned problems
are equivalent to determining the maximum cardinality of constant-rank codes
and to constructing optimal constant-rank codes, respectively. To this end, we
then derive bounds on the maximum cardinality of a constant-rank code with a
given minimum rank distance, propose explicit constructions of optimal or
asymptotically optimal constant-rank codes, and establish asymptotic bounds on
the maximum rate of a constant-rank code.


title:
Search for scalar top quarks in the acoplanar charm jets and missing
  transverse energy final state in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV

abstract:
  We present a search for the pair production of scalar top quarks,
$\tilde{t}$, using 995 pb$^{-1}$ of data collected in $p\bar{p}$ collisions
with the D0 detector at the Fermilab Tevatron Collider at $\sqrt{s} = 1.96$
TeV. Both scalar top quarks are assumed to decay into a charm quark and a
neutralino ($\tilde{\chi}^{0}_{1}$), where $\tilde{\chi}^{0}_{1}$ is the
lightest supersymmetric particle. This leads to a final state with two
acoplanar charm jets and missing transverse energy. We find the yield of such
events to be consistent with the standard model expectation, and exclude sets
of $\tilde{t}$ and $\tilde{\chi}^{0}_{1} $ masses at the 95% C.L. that
substantially extend the domain excluded by previous searches.


title:
Dynamics of Enceladus and Dione inside the 2:1 Mean-Motion Resonance
  under Tidal Dissipation

abstract:
  In a previous work (Callegari and Yokoyama 2007, Celest. Mech. Dyn. Astr.
vol. 98), the main features of the motion of the pair Enceladus-Dione were
analyzed in the frozen regime, i.e., without considering the tidal evolution.
Here, the results of a great deal of numerical simulations of a pair of
satellites similar to Enceladus and Dione crossing the 2:1 mean-motion
resonance are shown. The resonance crossing is modeled with a linear tidal
theory, considering a two-degrees-of-freedom model written in the framework of
the general three-body planar problem. The main regimes of motion of the system
during the passage through resonance are studied in detail. We discuss our
results comparing them with classical scenarios of tidal evolution of the
system. We show new scenarios of evolution of the Enceladus-Dione system
through resonance not shown in previous approaches of the problem.


title:
Macroscopic Superpositions of Phase States with Bose-Einstein
  Condensates

abstract:
  Quantum superpositions of macroscopically distinguishable states having
distinct phases can be created with a Bose-Einstein condensate trapped in a
periodic potential. The experimental signature is contained in the phase
distribution of the interference patterns obtained after releasing the traps.
Moreover, in the double well case, this distribution exhibits a dramatic
dependence on the parity of the total number of atoms. We finally show that,
for single well occupations up to a few hundred atoms, the macroscopic quantum
superposition can be robust enough against decoherence to be experimentally
revealable within current technology.


title:
Localization of positive charge in DNA induced by its interaction with
  environment

abstract:
  Microscopic mechanisms of positive charge transfer in DNA remain unclear. A
quantum state of electron hole in DNA is determined by the competition of the
pi-stacking interaction $b$ sharing a charge between different base pairs and
the interaction $\lambda$ with the local environment which attempts to trap
charge. To determine which interaction dominates we investigated charge quantum
states in various $(GC)_{n}$ sequences choosing DNA parameters satisfying
experimental data for the balance of charge transfer rates $G^{+}
\leftrightarrow G_{n}^{+}$, $n=2,3$ \cite{FredMain}. We show that experimental
data can be consistent with theory only assuming $b\ll \lambda$ meaning that
charge is typically localized within the single $G$ site. Consequently any DNA
sequence including the one consisting of identical base pairs behaves more like
an insulating material then a molecular conductor. Our theory can be verified
experimentally, for instance measuring balance of charge transfer reactions
$G^{+} \leftrightarrow G_{n}^{+}$, $n \geq 4$ and comparing the experimental
results with our predictions.


title: 3He Spin-Dependent Cross Sections and Sum Rules

abstract:
  We present a measurement of the spin-dependent cross sections for the
\vec{^3He}(\vec{e},e')X} reaction in the quasielastic and resonance regions at
four-momentum transfer 0.1 < Q^2< 0.9 GeV^2. The spin-structure functions have
been extracted and used to evaluate the nuclear Burkhardt--Cottingham and
extended GDH sum rules for the first time. Impulse approximation and exact
three-body Faddeev calculations are also compared to the data in the
quasielastic region.


title: Nuclear Activity in Nearby Galaxies

abstract:
  A significant fraction of nearby galaxies show evidence of weak nuclear
activity unrelated to normal stellar processes. Recent high-resolution,
multiwavelength observations indicate that the bulk of this activity derives
from black hole accretion with a wide range of accretion rates. The low
accretion rates that typify most low-luminosity active galactic nuclei induce
significant modifications to their central engine. The broad-line region and
obscuring torus disappear in some of the faintest sources, and the optically
thick accretion disk transforms into a three-component structure consisting of
an inner radiatively inefficient accretion flow, a truncated outer thin disk,
and a jet or outflow. The local census of nuclear activity supports the notion
that most, perhaps all, bulges host a central supermassive black hole, although
the existence of active nuclei in at least some late-type galaxies suggests
that a classical bulge is not a prerequisite to seed a nuclear black hole.


title: Coherent States and Bayesian Duality

abstract:
  We demonstrate how large classes of discrete and continuous statistical
distributions can be incorporated into coherent states, using the concept of a
reproducing kernel Hilbert space. Each family of coherent states is shown to
contain, in a sort of duality, which resembles an analogous duality in Bayesian
statistics, a discrete probability distribution and a discretely parametrized
family of continuous distributions. It turns out that nonlinear coherent
states, of the type widely studied in quantum optics, are a particularly useful
class of coherent states from this point of view, in that they contain many of
the standard statistical distributions. We also look at vector coherent states
and multidimensional coherent states as carriers of mixtures of probability
distributions and joint probability distributions.


title:
Non affine deformations and shape recovery in solids undergoing
  martensitic transformations

abstract:
  We study, using molecular dynamics simulations, the kinetics of shape
recovery in a model solid undergoing transformations from square to a general
rhombic lattice, the triangular lattice being included as a special case. We
determine the necessary and sufficient conditions for such shape recovery in
terms of the nature and dynamics of transient and localized {\em non-affine
zones} which inevitably accompany the transformation.


title: Coevolution of Supermassive Black Holes and Circumnuclear Disks

abstract:
  We propose a new evolutionary model of a supermassive black hole (SMBH) and a
circumnuclear disk (CND), taking into account the mass-supply from a host
galaxy and the physical states of CND. In the model, two distinct accretion
modes depending on gravitational stability of the CND play a key role on
accreting gas to a SMBH. (i) If the CMD is gravitationally unstable, energy
feedback from supernovae (SNe) supports a geometrically thick, turbulent gas
disk. The accretion in this mode is dominated by turbulent viscosity, and it is
significantly larger than that in the mode (ii), i.e., the CMD is supported by
gas pressure. Once the gas supply from the host is stopped, the high accretion
phase ($\sim 0.01- 0.1 M_{\odot} {\rm yr}^{-1}$) changes to the low one (mode
(ii), $\sim 10^{-4} M_{\odot} {\rm yr}^{-1}$), but there is a delay with $\sim
10^{8}$ yr. Through this evolution, the gas-rich CND turns into the gas poor
stellar disk. We found that not all the gas supplied from the host galaxy
accrete onto the SMBH even in the high accretion phase (mode (i)), because the
part of gas is used to form stars. As a result, the final SMBH mass ($M_{\rm
BH,final}$) is not proportional to the total gas mass supplied from the host
galaxy ($M_{\rm sup}$); $M_{\rm BH,final}/M_{\rm sup}$ decreases with $M_{\rm
sup}$.This would indicate that it is difficult to form a SMBH with $\sim 10^{9}
M_{\odot}$ observed at high-$z$ QSOs. The evolution of the SMBH and CND would
be related to the evolutionary tracks of different type of AGNs.


title:
Quantum Measurement Information as a key to Energy Release from Local
  Vacuums

abstract:
  In this paper, a protocol is proposed in which energy extraction from local
vacuum states is possible by using quantum measurement information for the
vacuum state of quantum fields. In the protocol, Alice, who stays at a spatial
point, excites the ground state of the fields by a local measurement.
Consequently, wavepackects generated by A' measurement propagate the vacuum to
spatial infinity. Let us assume that Bob stays away from Alice and fails to
catch the excitation energy when the wavepackets pass in front of him. Next
Alice announces her local measurement result to Bob by classical communication.
Bob performs a local unitary operation depending on the measurement result. In
this process, positive energy is released from the fields to Bob's apparatus of
the unitary operation. In the field systems, wavepackets are generated with
negative energy around Bob's location. Soon afterwards, the negative -energy
wavepackets begin to chase after the positive-energy wavepackets generated by
Alice and form loosely bound states.


title:
On two-dimensionalization of three-dimensional turbulence in shell
  models

abstract:
  Applying a modified version of the Gledzer-Ohkitani-Yamada (GOY) shell model,
the signatures of so-called two-dimensionalization effect of three-dimensional
incompressible, homogeneous, isotropic fully developed unforced turbulence have
been studied and reproduced. Within the framework of shell models we have
obtained the following results: (i) progressive steepening of the energy
spectrum with increased strength of the rotation, and, (ii) depletion in the
energy flux of the forward forward cascade, sometimes leading to an inverse
cascade. The presence of extended self-similarity and self-similar PDFs for
longitudinal velocity differences are also presented for the rotating 3D
turbulence case.


title:
Neutrino Masses from Cosmological Probes in Interacting Neutrino
  Dark-Energy Models

abstract:
  We investigate whether interaction between massive neutrinos and quintessence
scalar field is the origin of the late time accelerated expansion of the
universe. We present explicit formulas of the cosmological linear perturbation
theory in the neutrinos probes of dark-energy model, and calculate cosmic
microwave background anisotropies and matter power spectra. In these models,
the evolution of the mass of neutrinos is determined by the quintessence scalar
field, which is responsible for a varying effective equation of states:
$\omega_{eff}(z)$ goes down -1. We consider several types of scalar field
potential and put constraints on the coupling parameter between neutrinos and
dark energy. By combining data from cosmic microwave background (CMB)
experiments including the WMAP 3-year results, large scale structure with
2dFGRS data sets, we constrain the hypothesis of massive neutrinos in the
mass-varying neutrino scenario. Assuming the flatness of the universe, the
constraint we can derive from the current observation is $\sum m_{\nu} < 0.45$
eV at 1$\sigma$ (0.87 eV at 2$\sigma$) confidence level for the sum over three
species of neutrinos. The dynamics of scalar field and the impact of scalar
field perturbations on cosmic microwave background anisotropies are discussed.
We also discuss on the instability issue of the our model and confirm that
neutrinos are stable against the density fluctuation.


title: Mobility and its temperature dependence in LSCO: viscous motion?

abstract:
  We argue that charges in underdoped La$_{2-x}$Sr$_{x}$CuO$_{4}$ move in a
dissipative environment of strong spatial and temporal fluctuations. The
unusual temperature dependence of the Hall angle known as "the separation of
lifetimes" is reinterpreted and attributed to the appearance of the thermally
activated component in the effective number of carriers with the temperature
increase. We consider the temperature interval above $T_{c}$ where localization
effects can be neglected.


title:
Vector transition form factors of the $N K^*\to\Theta^+ $ and $N
  \bar{K}^*\to \Sigma_{\bar{10}}^{*-}$ in the SU(3) chiral quark-soliton model

abstract:
  We investigate the vector transition form factors of the nucleon and vector
meson K^* to the pentaquark baryon Theta^+ within the framework of the SU(3)
chiral quark-soliton model. We take into account the rotational 1/N_c and
linear $m_{\rm s}$ corrections, assuming isospin symmetry and employing the
symmetry-conserving quantization. It turns out that the leading-order
contributions to the form factors are almost cancelled by the rotational
corrections. Because of this, the flavor SU(3) symmetry-breaking terms yield
sizeable effects on the vector transition form factors. In particular, the main
contribution to the electric-like transition form factor comes from the
wave-function corrections, which is a consequence of the generalized
Ademollo-Gatto theorem derived in the present work. We estimate with the help
of the vector meson dominance the K^* vector and tensor coupling constants for
the Theta^+: $g_{K^{*}N\Theta}=0.74 - 0.87$ and $f_{K^{*}N\Theta}=0.53 - 1.16$.
We argue that the outcome of the present work is consistent with the null
results of the CLAS experiments in the reactions gamma n -> K^- Theta^+ and
gamma p ->bar{K}^0 Theta^+. The results of the present work are also consistent
with the recent experiments at KEK. In addition, we present the results of the
$\Sigma_{\bar{10}}\to N\bar{K}^*$ transition form factors and its
$\bar{K}^*N\Sigma_{\bar{10}}$ coupling constants.


title:
Effects of Chirped Laser Pulses on Nonclassical Correlation and
  Entanglement of Photon Pairs from Single Atom

abstract:
  We study the effects of arbitrary laser pulse excitations on quantum
correlation, entanglement and the role of quantum noise. The transient
quantities are computed exactly using a method that provides exact solutions of
the Langevin field operators for photon pairs produced by a double Raman atom
driven by laser pulses. Short pulses with appropriate chirping, delay and/or
detuning can generate broadband photon pairs and yield results that provide
insights on how to generate very large nonclassical correlation. We find that
short pulses are not favorable for entanglement. The quantity was previously
found to be phase-sensitive and this is used with the pulse area concept to
explain the rapid variations of entanglement with pulse width and strength.
Photon correlation and entanglement are favored by exclusively two different
initial conditions. Analysis reinforces our understanding of the two
nonclassical concepts.


title: Fermion Mass Hierarchies and Flavor Mixing from $T'$ Symmetry

abstract:
  We construct a supersymmetric model based on $T'\otimes Z_3\otimes Z_9$
flavor symmetry. At the leading order, the charged lepton mass matrix is not
diagonal, $T'$ is broken completely, and the hierarchy in the charged lepton
masses is generated naturally. Nearly tri-bimaximal mixing is predicted,
subleading effects induce corrections of order $\lambda^2$, where $\lambda$ is
the Cabibbo angle. Both the up quark and down quark mass matrices textures of
the well-known U(2) flavor theory are produced at the leading order, realistic
hierarchies in quark masses and CKM matrix elements are obtained. The vacuum
alignment and subleading corrections are discussed in detail.


title: Spin diode based on a single-wall carbon nanotube

abstract:
  Electronic transport through a single-wall metallic carbon nanotube weakly
coupled to one ferromagnetic and one nonmagnetic lead is analyzed in the
sequential tunneling limit. It is shown that both the spin and charge currents
flowing through such systems are highly asymmetric with respect to the bias
reversal. As a consequence, nanotubes coupled to one nonmagnetic and one
ferromagnetic lead can be effectively used as spin diodes whose functionality
can be additionally controlled by a gate voltage.


title: Secondary Photons from High-energy Protons Accelerated in Hypernovae

abstract:
  Recent observations show that hypernovae may deposit some fraction of their
kinetic energy in mildly relativistic ejecta. In the dissipation process of
such ejecta in a stellar wind, cosmic ray protons can be accelerated up to
$\sim 10^{19}$ eV. We discuss the TeV to MeV gamma-ray and the X-ray photon
signatures of cosmic rays accelerated in hypernovae. Secondary X-ray photons,
emitted by electron-positron pairs produced via cascade processes due to
high-energy protons, are the most promising targets for X-ray telescopes.
Synchrotron photons emitted by protons can appear in the GeV band, requiring
nearby ($<40$ Mpc) hypernovae for detection with GLAST. In addition, air
Cherenkov telescopes may be able to detect regenerated TeV photons emitted by
electron-positron pairs generated by CMB attenuation of $\pi^0$ decay photons.


title:
On Gautschi's conjecture for generalized Gauss-Radau and Gauss-Lobatto
  formulae

abstract:
  Recently, Gautschi introduced so-called generalized Gauss-Radau and
Gauss-Lobatto formulae which are quadrature formulae of Gaussian type involving
not only the values but also the derivatives of the function at the endpoints.
In the present note we show the positivity of the corresponding weights; this
positivity has been conjectured already by Gautschi. As a consequence, we
establish several convergence theorems for these quadrature formulae.


title: A Hausdorff-Young inequality for measured groupoids

abstract:
  The classical Hausdorff-Young inequality for locally compact abelian groups
states that, for $1\le p\le 2$, the $L^p$-norm of a function dominates the
$L^q$-norm of its Fourier transform, where $1/p+1/q=1$. By using the theory of
non-commutative $L^p$-spaces and by reinterpreting the Fourier transform, R.
Kunze (1958) [resp. M. Terp (1980)] extended this inequality to unimodular
[resp. non-unimodular] groups. The analysis of the $L^p$-spaces of the von
Neumann algebra of a measured groupoid provides a further extension of the
Hausdorff-Young inequality to measured groupoids.


title: Feasibility of Portfolio Optimization under Coherent Risk Measures

abstract:
  It is shown that the axioms for coherent risk measures imply that whenever
there is an asset in a portfolio that dominates the others in a given sample
(which happens with finite probability even for large samples), then this
portfolio cannot be optimized under any coherent measure on that sample, and
the risk measure diverges to minus infinity. This instability was first
discovered on the special example of Expected Shortfall which is used here both
as an illustration and as a prompt for generalization.


title: Cartan subalgebras in C*-algebras

abstract:
  According to J. Feldman and C. Moore's well-known theorem on Cartan
subalgebras, a variant of the group measure space construction gives an
equivalence of categories between twisted countable standard measured
equivalence relations and Cartan pairs, i.e. a von Neumann algebra (on a
separable Hilbert space) together with a Cartan subalgebra. A. Kumjian gave a
C*-algebraic analogue of this theorem in the early eighties. After a short
survey of maximal abelian self-adjoint subalgebras in operator algebras, I
present a natural definition of a Cartan subalgebra in a C*-algebra and an
extension of Kumjian's theorem which covers graph algebras and some foliation
algebras.


title: A Practical Attack on the MIFARE Classic

abstract:
  The MIFARE Classic is the most widely used contactless smart card in the
market. Its design and implementation details are kept secret by its
manufacturer. This paper studies the architecture of the card and the
communication protocol between card and reader. Then it gives a practical,
low-cost, attack that recovers secret information from the memory of the card.
Due to a weakness in the pseudo-random generator, we are able to recover the
keystream generated by the CRYPTO1 stream cipher. We exploit the malleability
of the stream cipher to read all memory blocks of the first sector of the card.
Moreover, we are able to read any sector of the memory of the card, provided
that we know one memory block within this sector. Finally, and perhaps more
damaging, the same holds for modifying memory blocks.


title: Mirror fibrations and root stacks of weighted projective spaces

abstract:
  We show that the orbifold Chow ring of a root stack over a well-formed
weighted projective space can be naturally seen as the Jacobian algebra of a
function on a singular variety given by a partial compactification of its
Ginzburg-Landau model.


title: Asymmetric exclusion processes with constrained dynamics

abstract:
  Asymmetric exclusion processes with locally reversible kinetic constraints
are introduced to investigate the effect of non-conservative driving forces in
athermal systems. At high density they generally exhibit rheological-like
behavior, negative differential resistance, two-step structural relaxation,
dynamical heterogeneity and, possibly, a jamming transition driven by the
external field.


title: A Note on the Generalized Friedmann Equations for a Thick Brane

abstract:
  Within our thick brane approach previously used to obtain the cosmological
evolution equations on a thick brane embedded in a five-dimensional
Schwarzschild Anti-de Sitter spacetime it is explicitly shown that the
consistency of these equations with the energy conservation equation requires
that, in general, the thickness of the brane evolves in time. This varying
brane thickness entails the possibility that both Newton's gravitational
constant $G$ and the effective cosmological constant $\Lambda_4$ are time
dependent.


title:
Non-Relativistic Positronium Spectrum in Relativistic Schroedinger
  Theory

abstract:
  The lowest energy levels of positronium are studied in the non-relativistic
approximation within the framework of Relativistic Schr\"odinger Theory (RST).
Since it is very difficult to find the exact solutions of the RST field
equations (even in the non-relativistic limit), an approximation scheme is set
up on the basis of the hydrogen-like wave functions (i.e. polynomial times
exponential). For any approximation order $\NN (\NN=0,1,2,3,...)$ there arises
a spectrum of approximate RST solutions with the associated energies, quite
similarly to the conventional treatment of positronium in the standard quantum
theory (Appendix). For the lowest approximation order $(\NN=0)$ the RST
prediction for the \emph{groundstate} energy exactly agrees with the
conventional prediction of the standard theory. However for the higher
approximation orders $(\NN=1,2,3)$, the corresponding RST prediction differs
from the conventional result by (roughly) $0,9 [eV]$ which confirms the
previous estimate of the error being due to the use of the spherically
symmetric approximation. The excited states require the application of
higher-order approximations $(\NN>>3)$ and are therefore not adequately
described by the present orders $(\NN\le 3)$.


title: Phase Separation under Ultra-Slow Cooling: Onset of Nucleation

abstract:
  We discuss the interplay between a slow continuous drift of temperature,
which induces continuous phase separation, and the non-linear diffusion term in
the $\phi^4$-model for phase separation of a binary mixture. This leads to a
bound for the stability of diffusive demixing. It is argued that these findings
are not specific to the $\phi^4$ model, but that they always apply up to slight
modifications of the bound. In practice stable diffusive demixing can only be
achieved when special precautions are taken in experiments on real mixtures.
Therefore, the recent observations on complex dynamical behavior in such
systems should be considered as a new challenge for understanding generic
features of phase-separating systems.


title:
Dependence of single-particle energies on coupling constants of the
  nuclear energy density functional

abstract:
  We show that single-particle energies in doubly magic nuclei depend almost
linearly on the coupling constants of the nuclear energy density functional.
Therefore, they can be very well characterized by the linear regression
coefficients, which we calculate for the coupling constants of the standard
Skyrme functional. We then use these regression coefficients to refit the
coupling constants to experimental values of single-particle energies. We show
that the obtained rms deviations from experimental data are still quite large,
of the order of 1.1 MeV. This suggests that the current standard form of the
Skyrme functional cannot ensure spectroscopic-quality description of
single-particle energies, and that extensions of this form are very much
required.


title:
Elliptic Quantum Group U_{q,p}(\hat{sl}_2), Hopf Algebroid Structure and
  Elliptic Hypergeometric Series

abstract:
  We propose a new realization of the elliptic quantum group equipped with the
H-Hopf algebroid structure on the basis of the elliptic algebra
U_{q,p}(\hat{sl}_2). The algebra U_{q,p}(\hat{sl}_2) has a constructive
definition in terms of the Drinfeld generators of the quantum affine algebra
U_q(\hat{sl}_2) and a Heisenberg algebra. This yields a systematic construction
of both finite and infinite-dimensional dynamical representations and their
parallel structures to U_q(\hat{sl}_2). In particular we give a classification
theorem of the finite-dimensional irreducible pseudo-highest weight
representations stated in terms of an elliptic analogue of the Drinfeld
polynomials. We also investigate a structure of the tensor product of two
evaluation representations and derive an elliptic analogue of the
Clebsch-Gordan coefficients. We show that it is expressed by using the
very-well-poised balanced elliptic hypergeometric series 12V11.


title: Superfluid to insulator phase transition in a unitary Fermi gas

abstract:
  We study the evolution of the energy gap in a unitary Fermi gas as a function
of temperature. To this end we approximate the Fermi gas by the Hubbard lattice
Hamiltonian and solve using the dynamical mean-field approximation. We have
found that below the critical temperature, Tc, the system is a superfluid and
the energy gap is decreasing monotonously. For temperatures above Tc the system
is an insulator and the corresponding energy gap is monotonously increasing.


title: Generalized retarded integral inequalities

abstract:
  We prove some new retarded integral inequalities. The results generalize
those in [J. Math. Anal. Appl. 301 (2005), no. 2, 265--275].