title: A Procedure to Solve the Eigen Solution to Dirac Equation

abstract:
  In this paper, we provide a procedure to solve the eigen solutions of Dirac
equation with complicated potential approximately. At first, we solve the eigen
solutions of a linear Dirac equation with complete eigen system, which
approximately equals to the original equation. Take the eigen functions as base
of Hilbert space, and expand the spinor on the bases, we convert the original
problem into solution of extremum of an algebraic function on the unit sphere
of the coefficients. Then the problem can be easily solved. This is a standard
finite element method with strict theory for convergence and effectiveness.


title:
Tripartite entanglement and threshold properties of coupled intracavity
  downconversion and sum-frequency generation

abstract:
  The process of cascaded downconversion and sum-frequency generation inside an
optical cavity has been predicted to be a potential source of three-mode
continuous-variable entanglement. When the cavity is pumped by two fields, the
threshold properties have been analysed, showing that these are more
complicated than in well-known processes such as optical parametric
oscillation. When there is only a single pumping field, the entanglement
properties have been calculated using a linearised fluctuation analysis, but
without any consideration of the threshold properties or critical operating
points of the system. In this work we extend this analysis to demonstrate that
the singly pumped system demonstrates a rich range of threshold behaviour when
quantisation of the pump field is taken into account and that asymmetric
polychromatic entanglement is available over a wide range of operational
parameters.


title: General multipartite entangled states and complex projective variety

abstract:
  We discuss and investigate the geometrical structure of general multipartite
states. In particular, we show that a geometrical measure of entanglement for
general multipartite states can be constructed by the complex projective
varieties defined by quadratic polynomials.


title:
Constraining crystalline color superconducting quark matter with
  gravitational-wave data

abstract:
  We estimate the maximum equatorial ellipticity sustainable by compact stars
composed of crystalline color-superconducting quark matter. For the
theoretically allowed range of the gap parameter $\Delta$, the maximum
ellipticity could be as large as $10^{-2}$, which is about 4 orders of
magnitude larger than the tightest upper limit obtained by the recent science
runs of the LIGO and GEO600 gravitational wave detectors based on the data from
78 radio pulsars. We point out that the current gravitational-wave strain upper
limit already has some implications for the gap parameter. In particular, the
upper limit for the Crab pulsar implies that $\Delta$ is less than O(20) MeV
for a range of quark chemical potential accessible in compact stars, assuming
that the pulsar has a mass $1.4 M_{\odot}$, radius 10 km, breaking strain
$10^{-3}$, and that it has the maximum quadrupole deformation it can sustain
without fracturing.


title:
Quantum fluctuations in the transverse Ising spin glass model: A field
  theory of random quantum spin systems

abstract:
  We develop a mean-field theory for random quantum spin systems using the spin
coherent state path integral representation. After the model is reduced to the
mean field one-body Hamiltonian, the integral is analyzed with the aid of
several methods such as the semiclassical method and the gauge transformation.
As an application we consider the Sherrington-Kirkpatrick model in a transverse
field. Using the Landau expansion and its improved versions, we give a detailed
analysis of the imaginary-time dependence of the order parameters. Integrating
out the quantum part of the order parameters, we obtain the effective
renormalized free energy written in terms of the classically defined order
parameters. Our method allows us to obtain the spin glass-paramagnetic phase
transition point $\Gamma/J\sim 1.62$ at T=0.


title:
The Second Born Corrections to the Electrical and Thermal Conductivities
  of Dense Matter in the Liquid Metal Phase

abstract:
  The second Born corrections to the electrical and thermal conductivities are
calculated for the dense matter in the liquid metal phase for various elemental
compositions of astrophysical importance. Inclusion up to the second Born
corrections is sufficiently accurate for the Coulomb scattering of the
electrons by the atomic nuclei with Z < 26. Our approach is semi-analytical,
and is in contrast to that of the previous authors who have used fully
numerical values of the cross section for the Coulomb scattering of the
electron by the atomic nucleus. The merit of the present semi-analytical
approach is that this approach affords us to obtain the results with reliable
Z-dependence and \rho-dependence. The previous fully numerical approach has
made use of the numerical values of the cross section for the scattering of the
electron off the atomic nucleus for a limited number of Z-values, Z=6, 13, 29,
50, 82, and 92, and for a limited number of electron energies, 0.05MeV, 0.1MeV,
0.2MeV, 0.4MeV, 0.7MeV, 1MeV, 2MeV, 4MeV, and 10MeV. Our study, however, has
confirmed that the previous results are sufficiently accurate. They are
recovered, if the terms higher than the second Born terms are taken into
account. We make a detailed comparison of the present results with those of the
previous authors. The numerical results are parameterized in a form of analytic
formulae that would facilitate practical uses of the results. We also extend
our calculations to the case of mixtures of nuclear species. The corresponding
subroutine can be retrieved from
http://www.ph.sophia.ac.jp/~itoh-ken/subroutine/subroutine.htm


title:
Search for strange tribaryon states in the inclusive
  ^4He(K^{-}_{stopped}, p) reaction

abstract:
  A search for tribaryon states was performed at KEK-PS. We adopted the
$^4$He($K^-_{stopped}, p)$ reaction to populate the states with strangeness -1,
charge 0 and isospin 1. No significant narrow structure was observed in the
mass region from 3000 to 3200 MeV/c^2 in an inclusive missing mass spectrum.
The upper limit of the formation branching ratio was determined to be
($1\sim3)\times 10^{-4}$, ($0.7\sim2)\times 10^{-3}$ and ($2\sim8) \times
10^{-3}$/($stopped K^{-}$) with 95 % confidence level for narrow states with an
assumed width of 0, 20 and 40 MeV/c^2, respectively.


title: Inequivalent quantization in the field of a ferromagnetic wire

abstract:
  We argue that it is possible to bind neutral atom (NA) to the ferromagnetic
wire (FW) by inequivalent quantization of the Hamiltonian. We follow the well
known von Neumann's method of self-adjoint extensions (SAE) to get this
inequivalent quantization, which is characterized by a parameter
\Sigma\in\mathbb{R}({mod}2\pi). There exists a single bound state for the
coupling constant \eta^2\in[0,1). Although this bound state should not occur
due to the existence of classical scale symmetry in the problem. But since
quantization procedure breaks this classical symmetry, bound state comes out as
a scale in the problem leading to scaling anomaly. We also discuss the strong
coupling region \eta^2< 0, which supports bound state making the problem
re-normalizable.


title:
Wightman function and scalar Casimir densities for a wedge with two
  cylindrical boundaries

abstract:
  Wightman function, the vacuum expectation values of the field square and the
energy-momentum tensor are investigated for a massive scalar field with general
curvature coupling parameter inside a wedge with two coaxial cylindrical
boundaries. It is assumed that the field obeys Dirichlet boundary condition on
bounding surfaces. The application of a variant of the generalized Abel-Plana
formula enables to extract from the expectation values the contribution
corresponding to the geometry of a wedge with a single shell and to present the
interference part in terms of exponentially convergent integrals. The local
properties of the vacuum are investigated in various asymptotic regions of the
parameters. The vacuum forces acting on the boundaries are presented as the sum
of self-action and interaction terms. It is shown that the interaction forces
between the separate parts of the boundary are always attractive. The
generalization to the case of a scalar field with Neumann boundary condition is
discussed.


title: Indo-European languages tree by Levenshtein distance

abstract:
  The evolution of languages closely resembles the evolution of haploid
organisms. This similarity has been recently exploited \cite{GA,GJ} to
construct language trees. The key point is the definition of a distance among
all pairs of languages which is the analogous of a genetic distance. Many
methods have been proposed to define these distances, one of this, used by
glottochronology, compute distance from the percentage of shared ``cognates''.
Cognates are words inferred to have a common historical origin, and subjective
judgment plays a relevant role in the identification process. Here we push
closer the analogy with evolutionary biology and we introduce a genetic
distance among language pairs by considering a renormalized Levenshtein
distance among words with same meaning and averaging on all the words contained
in a Swadesh list \cite{Sw}. The subjectivity of process is consistently
reduced and the reproducibility is highly facilitated. We test our method
against the Indo-European group considering fifty different languages and the
two hundred words of the Swadesh list for any of them. We find out a tree which
closely resembles the one published in \cite{GA} with some significant
differences.


title: The inverse fallacy and quantum formalism

abstract:
  In the present article we consider the inverse fallacy, a well known
cognitive heuristic experimentally tested in cognitive science, which occurs
for intuitive judgments in situations of bounded rationality. We show that the
quantum formalism can be used to describe in a very simple and general way this
fallacy within the quantum formalism. Thus we suggest that in cognitive science
the formalism of quantum mechanics can be used to describe a quantum regime,
the bounded-rationality regime, where the cognitive heuristics are valid.


title: Detecting q-Gaussian distributions and the normalization effect

abstract:
  We show that whenever data are gathered using a device that performs a
normalization-preprocessing, the ensuing normalized input, as recorded by the
measurement device, will always be q-Gaussian distributed if the incoming data
exhibit elliptical symmetry. As a consequence, great care should be exercised
when detecting q-Gaussians. As an example, Gaussian data will appear, after
normalization, in the guise of q-Gaussian records. Moreover, we show that the
value of the resulting parameter q can be deduced from the normalization
technique that characterizes the device.


title: The Fuzzy Vault for fingerprints is Vulnerable to Brute Force Attack

abstract:
  The \textit{fuzzy vault} approach is one of the best studied and well
accepted ideas for binding cryptographic security into biometric
authentication. The vault has been implemented in connection with fingerprint
data by Uludag and Jain. We show that this instance of the vault is vulnerable
to brute force attack. An interceptor of the vault data can recover both secret
and template data using only generally affordable computational resources. Some
possible alternatives are then discussed and it is suggested that cryptographic
security may be preferable to the one - way function approach to biometric
security.


title: Neutrino flavor oscillations in background matter

abstract:
  We study the evolution of two mixed Dirac neutrinos in an external
axial-vector field. The dynamics of this system is described in the framework
of relativistic wave equations approach on the basis of the known solutions of
the Dirac equation in an external field with a given initial condition. The
general solution of the initial condition problem, exactly accounting for the
external field, is obtained. Then we consider special form of the external
field which corresponds to the standard model neutrino interactions with the
background matter. In this limit we derive the transition probability and
compare it with the previously known results.


title: Voltage and temperature dependencies of conductivity in gated graphene

abstract:
  The resistivity of gated graphene is studied taking into account electron and
hole scattering by short- and long-range structural imperfections the
characteristics of disorder were taken from the scanning tunneling microscopy
data and by acoustic phonons. The calculations are based on the quasiclassical
kinetic equation with the normalization condition fixed by surface charge. The
gate-voltage and temperature effects on the resistance peak, which is centered
at the point of intrinsic conductivity, are found to be in agreement with the
transport measurements.


title: Two Component Model of Dark Energy

abstract:
  We consider the possibility that the dark energy is made up of two or more
independent components, each having a different equation of state. We fit the
model with supernova and gamma-ray burst (GRB) data from resent observations,
and use the Markov Chain Monte Carlo (MCMC) technique to estimate the allowed
parameter regions. We also use various model selection criteria to compare the
two component model with the LCDM, one component dark energy model with static
or variable w(XCDM), and with other multi-component models. We find that the
two component models can give reasonably good fit to the current data. For some
data sets, and depending somewhat on the model selection criteria, the two
component model can give better fit to the data than XCDM with static w and
XCDM with variable w parameterized by w = w_0 + w_az/(1+z).


title: Entanglement Entropy in Extended Quantum Systems

abstract:
  After a brief introduction to the concept of entanglement in quantum systems,
I apply these ideas to many-body systems and show that the von Neumann entropy
is an effective way of characterising the entanglement between the degrees of
freedom in different regions of space. Close to a quantum phase transition it
has universal features which serve as a diagnostic of such phenomena. In the
second part I consider the unitary time evolution of such systems following a
`quantum quench' in which a parameter in the hamiltonian is suddenly changed,
and argue that finite regions should effectively thermalise at late times,
after interesting transient effects.


title: Phase coexistence of cluster crystals: beyond the Gibbs phase rule

abstract:
  We report a study of the phase behavior of multiple-occupancy crystals
through simulation. We argue that in order to reproduce the equilibrium
behavior of such crystals it is essential to treat the number of lattice sites
as a constraining thermodynamic variable. The resulting free-energy
calculations thus differ considerably from schemes used for single-occupancy
lattices. Using our approach, we obtain the phase diagram and the bulk modulus
for a generalized exponential model that forms cluster crystals at high
densities. We compare the simulation results with existing theoretical
predictions. We also identify two types of density fluctuations that can lead
to two sound modes and evaluate the corresponding elastic constants.


title:
Astrophysical Configurations with Background Cosmology: Probing Dark
  Energy at Astrophysical Scales

abstract:
  We explore the effects of a positive cosmological constant on astrophysical
and cosmological configurations described by a polytropic equation of state. We
derive the conditions for equilibrium and stability of such configurations and
consider some astrophysical examples where our analysis may be relevant. We
show that in the presence of the cosmological constant the isothermal sphere is
not a viable astrophysical model since the density in this model does not go
asymptotically to zero. The cosmological constant implies that, for polytropic
index smaller than five, the central density has to exceed a certain minimal
value in terms of the vacuum density in order to guarantee the existence of a
finite size object. We examine such configurations together with effects of
$\Lambda$ in other exotic possibilities, such as neutrino and boson stars, and
we compare our results to N-body simulations. The astrophysical properties and
configurations found in this article are specific features resulting from the
existence of a dark energy component. Hence, if found in nature would be an
independent probe of a cosmological constant, complementary to other
observations.


title: A stabilization theorem for dynamics of continuous opinions

abstract:
  A stabilization theorem for processes of opinion dynamics is presented. The
theorem is applicable to a wide class of models of continuous opinion dynamics
based on averaging (like the models of Hegselmann-Krause and
Weisbuch-Deffuant). The analysis detects self-confidence as a driving force of
stabilization.


title: ILC Positron Production Target Simulation

abstract:
  A photon-positron conversion target of the undulator or laser based polarized
positron source is optimized using a modified GEANT-3 program adapted to count
the spin transfer. High intensity positron beam with around 0.75 polarisation
could be achieved choosing tungsten conversion target of 0.3 and 0.7 radiation
lengths for the undulator and laser case respectively.


title: Velocity fluctuations in a one dimensional Inelastic Maxwell model

abstract:
  We consider the velocity fluctuations of a system of particles described by
the Inelastic Maxwell Model. The present work extends the methods, previously
employed to obtain the one-particle velocity distribution function, to the
study of the two particle correlations. Results regarding both the homogeneous
cooling process and the steady state driven regime are presented. In particular
we obtain the form of the pair correlation function in the scaling region of
the homogeneous cooling process and show that some of its moments diverge. This
fact has repercussions on the behavior of the energy fluctuations of the model.


title:
Are neutron stars with crystalline colour superconducting cores
  interesting for the LIGO experiment?

abstract:
  We estimate the maximal deformation that can be sustained by a rotating
neutron star with a crystalline colour superconducting quark core. Our results
suggest that current gravitational-wave data from LIGO have already reached the
level where a detection would have been possible over a wide range of the
poorly constrained QCD parameters. This leads to the non-trivial conclusion
that compact objects \emph{do not} contain maximally strained colour
crystalline cores drawn from this range of parameter space. We discuss the
uncertainties associated with our simple model and how it can be improved in
the future.


title:
Suppression of vortex channeling in meandered YBa2Cu3O7-d grain
  boundaries

abstract:
  We report on the in-plane magnetic field (H) dependence of the critical
current density (Jc) in meandered and planar single grain boundaries (GBs)
isolated in YBa2Cu3O7-d (YBCO) coated conductors. The Jc(H)properties of the
planar GB are consistent with those previously seen in single GBs of YBCO films
grown on SrTiO3 bi-crystals. In the straight boundary a characteristic flux
channeling regime when H is oriented near the GB plane, associated with a
reduced Jc, is seen. The meandered GB does not show vortex channeling since it
is not possible for a sufficient length of vortex line to lie within it.


title: On the Security of the Ping-Pong Protocol

abstract:
  We briefly review the security of the ping-pong protocol in light of several
attack scenarios suggested by various authors since the proposal of the
protocol. We refute one recent attack on an ideal quantum channel, and show
that a recent claim of falseness of our original security proof is erroneous.


title: On the Low-lying zeros of Hasse-Weil L-functions for Elliptic Curves

abstract:
  In this paper, we obtain an unconditional density theorem concerning the
low-lying zeros of Hasse-Weil L-functions for a family of elliptic curves. From
this together with the Riemann hypothesis for these L-functions, we infer the
majorant of 27/14 (which is strictly less than 2) for the average rank of the
elliptic curves in the family under consideration. This upper bound for the
average rank enables us to deduce that, under the same assumption, a positive
proportion of elliptic curves have algebraic ranks equaling their analytic
ranks and finite Tate-Shafarevic group. Statements of this flavor were known
previously under the additional assumptions of GRH for Dirichlet L-functions
and symmetric square L-functions which are removed in the present paper.


title:
The in-flight spectroscopic performance of the Swift XRT CCD camera
  during 2006-2007

abstract:
  The Swift X-ray Telescope focal plane camera is a front-illuminated MOS CCD,
providing a spectral response kernel of 135 eV FWHM at 5.9 keV as measured
before launch. We describe the CCD calibration program based on celestial and
on-board calibration sources, relevant in-flight experiences, and developments
in the CCD response model. We illustrate how the revised response model
describes the calibration sources well. Comparison of observed spectra with
models folded through the instrument response produces negative residuals
around and below the Oxygen edge. We discuss several possible causes for such
residuals. Traps created by proton damage on the CCD increase the charge
transfer inefficiency (CTI) over time. We describe the evolution of the CTI
since the launch and its effect on the CCD spectral resolution and the gain.


title: Fast optimal CMB power spectrum estimation with Hamiltonian sampling

abstract:
  We present a method for fast optimal estimation of the temperature angular
power spectrum from observations of the cosmic microwave background. We employ
a Hamiltonian Monte Carlo (HMC) sampler to obtain samples from the posterior
probability distribution of all the power spectrum coefficients given a set of
observations. We compare the properties of the HMC and the related Gibbs
sampling approach on low-resolution simulations and find that the HMC method
performs favourably even in the regime of relatively low signal-to-noise. We
also demonstrate the method on high-resolution data by applying it to simulated
WMAP data. Analysis of a WMAP-sized data set is possible in a around eighty
hours on a high-end desktop computer. HMC imposes few conditions on the
distribution to be sampled and provides us with an extremely flexible approach
upon which to build.


title: Quantum gravity and charge renormalization

abstract:
  We study the question of the gauge dependence of the quantum gravity
contribution to the running gauge coupling constant for electromagnetism. The
calculations are performed using dimensional regularization in a manifestly
gauge invariant and gauge condition independent formulation of the effective
action. It is shown that there is no quantum gravity contribution to the
running charge, and hence there is no alteration to asymptotic freedom at high
energies as predicted by Robinson and Wilczek.


title:
Shape resonances in modified effective range theory for
  electron-molecule collisions

abstract:
  We develop a simple model of shape resonances in electron-molecule collisions
that is based on the modified effective-range expansion and analytical
solutions of the Schrodinger equation for the long-range part of the
interaction potential. We apply our model to electron scattering on N$_2$ and
CO$_2$. The parameters of the effective-range expansion (i.e. the scattering
length and the effective range) are determined from experimental, integral
elastic cross sections in the 0.1 - 1.0 eV energy range. For both molecular
targets our treatment predicts shape resonances that appear slightly higher
than experimentally known resonances in total cross sections. Agreement with
the experiment can be improved by assuming the position of the resonance in a
given partial wave. Influence of quadrupole potential on resonances is also
discussed: it can be disregarded for N$_2$ but gets significant for CO$_2$. In
conclusion, our model developed within the effective range formalism reproduces
well both the very low-energy behavior of the integral cross section as well as
the presence of resonances in the few eV range.


title: Quantum private queries

abstract:
  We propose a cheat sensitive quantum protocol to perform a private search on
a classical database which is efficient in terms of communication complexity.
It allows a user to retrieve an item from the server in possession of the
database without revealing which item she retrieved: if the server tries to
obtain information on the query, the person querying the database can find it
out. Furthermore our protocol ensures perfect data privacy of the database,
i.e. the information that the user can retrieve in a single queries is bounded
and does not depend on the size of the database. With respect to the known
(quantum and classical) strategies for private information retrieval, our
protocol displays an exponential reduction both in communication complexity and
in running-time computational complexity.


title:
Quantum-like Description of Probabilistic Data from Shafir-Tversky
  Experiments: evidence of trigonometric and hyperbolic (!) interference

abstract:
  In this paper we present quantum-like (QL) representation of the
Shafir-Tversky statistical effect. We apply so called contextual approach. The
Shafir-Tversky effect is considered as a consequence of combination of a number
of incompatible contexts which are involved e.g. in Prisoner's Dilemma or in
more general games inducing the disjunction effect. As a consequence, the law
of total probability is violated for experimental data obtained by Shafir and
Tversky (1992) as well as Tversky and Shafir (1992). Moreover, we can find a
numerical measure of contextual incompatibility (so called coefficient of
interference) as well as represent contexts which are involved in Prisoner's
Dilemma (PD) by probability amplitudes -- normalized vectors (``mental wave
functions''). We remark that statistical data from Shafir and Tversky (1992)
and Tversky and Shafir (1992) experiments differ crucially from the point of
view of mental interference. The second one exhibits the conventional
trigonometric ($\cos$-type) interference, but the first one exhibits so called
hyperbolic ($\cosh$-type) interference. We discuss QL processing of information
by cognitive systems, in particular, QL decision making as well as classical
and QL rationality.


title: Surface electric potential dynamic on graphite

abstract:
  We observe variations on the surface potential of graphite samples that we
attribute to the adsorption physisorption of tetracene isomers.


title: On the conjecture of Kevin Walker

abstract:
  In 1985 Kevin Walker in his study of topology of polygon spaces raised an
interesting conjecture in the spirit of the well-known question "Can you hear
the shape of a drum?" of Marc Kac. Roughly, Walker's conjecture asks if one can
recover relative lengths of the bars of a linkage from intrinsic algebraic
properties of the cohomology algebra of its configuration space. In this paper
we prove that the conjecture is true for polygon spaces in R^3. We also prove
that for planar polygon spaces the conjecture holds is several modified forms:
(a) if one takes into account the action of a natural involution on cohomology,
(b) if the cohomology algebra of the involution's orbit space is known, or (c)
if the length vector is normal. Some of our results allow the length vector to
be non-generic, the corresponding polygon spaces have singularities. Our main
tool is the study of the natural involution and its action on cohomology. A
crucial role in our proof plays the solution of the isomorphism problem for
monoidal rings due to J. Gubeladze.


title:
Structure and Nuclear Composition of General Relativistic,
  Magnetohydrodynamic Outflows from Neutrino-Cooled Disks

abstract:
  We compute the structure and degree of neutronization of general relativistic
magnetohydrodynamic (GRMHD) outflows originating from the inner region of
neutrino-cooled disks. We consider both, outflows expelled from a hydrostatic
disk corona and outflows driven by disk turbulence. We show that in outflows
driven thermally from a static disk the electron fraction quickly evolves to
its equilibrium value which is dominated by neutrino capture. Those outflows
are generally proton rich and, under certain conditions, can be magnetically
dominated. They may also provide sites for effective production of 56Ni.
Centrifugally driven outflows and outflows driven by disk turbulence, on the
other hand, can preserve the large in-disk neutron excess. Those outflows are,
quite generally, subrelativistic by virtue of the large mass flux driven by the
additional forces.


title: Topology of randon linkages

abstract:
  Betti numbers of configuration spaces of mechanical linkages (known also as
polygon spaces) depend on a large number of parameters -- the lengths of the
bars of the linkage. Motivated by applications in topological robotics,
statistical shape theory and molecular biology, we view these lengths as random
variables and study asymptotic values of the average Betti numbers as the
number of links n tends to infinity. We establish a surprising fact that for a
reasonably ample class of sequences of probability measures the asymptotic
values of the average Betti numbers are independent of the choice of the
measure. The main results of the paper apply to planar linkages as well as for
linkages in R^3. We also prove results about higher moments of Betti numbers.


title: Relative non-relativistic mechanics

abstract:
  Dynamic equations of non-relativistic mechanics are written in
covariant-coordinate form in terms of relative velocities and accelerations
with respect to an arbitrary reference frame. The notions of the
non-relativistic reference frame, inertial force, free motion equation, and
inertial frame are discussed.


title:
On the estimation of a parameter with incomplete knowledge on a nuisance
  parameter

abstract:
  In this paper we consider the problem of estimating a parameter of a
probability distribution when we have some prior information on a nuisance
parameter. We start by the very simple case where we know perfectly the value
of the nuisance parameter. The complete likelihood is the classical tool in
this case. Then, progressively, we consider the case where we are given a prior
probability distribution on this nuisance parameter. The marginal likelihood is
then the classical tool in this case. Then, we consider the case where we only
have a fixed number of its moments. Here, we may use the maximum entropy (ME)
principle to assign a prior law and thus go back to the previous case. Finally,
we consider the case where we know only its median. In our knowledge, there is
not any classical tool for this case. We propose then a new tool for this case
based on a recently proposed alternative distribution to the marginal
probability distribution. This new criterion is obtained by first remarking
that the marginal distribution can be considered as the mean value of the
original distribution over the prior probability law of the nuisance parameter,
and then, by using the median in place of the mean. In this paper, we first
summarize the classical tools used for the three first cases, then we give the
precise definition of this new criterion and its properties and, finally,
present a few examples to show the differences of these cases.
  Key Words: Nuisance parameter, Bayesian inference, Maximum Entropy,
Marginalization, Incomplete knowledge, Mean and Median of the Likelihood over
the prior distribution


title:
The Physical Properties of LBGs at z>5: Outflows and the "pre-enrichment
  problem"

abstract:
  We discuss the properties of Lyman Break galaxies (LBGs) at z>5 as determined
from disparate fields covering approximately 500 sq. arcmin. While the broad
characteristics of the LBG population has been discussed extensively in the
literature, such as luminosity functions and clustering amplitude, we focus on
the detailed physical properties of the sources in this large survey (>100 with
spectroscopic redshifts). Specifically, we discuss ensemble mass estimates,
stellar mass surface densities, core phase space densities, star-formation
intensities, characteristics of their stellar populations, etc as obtained from
multi-wavelength data (rest-frame UV through optical) for a subsample of these
galaxies. In particular, we focus on evidence that these galaxies drive
vigorous outflows and speculate that this population may solve the so-called
``pre-enrichment problem''. The general picture that emerges from these studies
is that these galaxies, observed about 1 Gyr after the Big Bang, have
properties consistent with being the progenitors of the densest stellar systems
in the local Universe -- the centers of old bulges and early type galaxies.


title: Anomaly induced effects in a magnetic field

abstract:
  We consider a modification of electrodynamics by an additional light massive
vector field, interacting with the photon via Chern-Simons-like coupling. This
theory predicts observable effects for the experiments studying the propagation
of light in an external magnetic field, very similar to those, predicted by
theories of axion and axion-like particles. We discuss a possible microscopic
origin of this theory from a theory with non-trivial gauge anomaly cancellation
between massive and light particles (including, for example, millicharged
fermions). Due to the conservation of the gauge current, the production of the
new vector field is suppressed at high energies. As a result, this theory can
avoid both stellar bounds (which exist for axions) and the bounds from CMB
considered recently, allowing for positive results in experiments like ALPS,
LIPPS, OSQAR, PVLAS-2, BMV, Q&A, etc.


title: Twisting all the way: from Classical Mechanics to Quantum Fields

abstract:
  We discuss the effects that a noncommutative geometry induced by a Drinfeld
twist has on physical theories. We systematically deform all products and
symmetries of the theory. We discuss noncommutative classical mechanics, in
particular its deformed Poisson bracket and hence time evolution and
symmetries. The twisting is then extended to classical fields, and then to the
main interest of this work: quantum fields. This leads to a geometric
formulation of quantization on noncommutative spacetime, i.e. we establish a
noncommutative correspondence principle from *-Poisson brackets to
*-commutators. In particular commutation relations among creation and
annihilation operators are deduced.


title: The dynamics of vortex generation in superfluid 3He-B

abstract:
  A profound change occurs in the stability of quantized vortices in externally
applied flow of superfluid 3He-B at temperatures ~ 0.6 Tc, owing to the rapidly
decreasing damping in vortex motion with decreasing temperature. At low damping
an evolving vortex may become unstable and generate a new independent vortex
loop. This single-vortex instability is the generic precursor to turbulence. We
investigate the instability with non-invasive NMR measurements on a rotating
cylindrical sample in the intermediate temperature regime (0.3 - 0.6) Tc. From
comparisons with numerical calculations we interpret that the instability
occurs at the container wall, when the vortex end moves along the wall in
applied flow.


title: The Far-Infrared Surveyor (FIS) for AKARI

abstract:
  The Far-Infrared Surveyor (FIS) is one of two focal plane instruments on the
AKARI satellite. FIS has four photometric bands at 65, 90, 140, and 160 um, and
uses two kinds of array detectors. The FIS arrays and optics are designed to
sweep the sky with high spatial resolution and redundancy. The actual scan
width is more than eight arcmin, and the pixel pitch is matches the diffraction
limit of the telescope. Derived point spread functions (PSFs) from observations
of asteroids are similar to the optical model. Significant excesses, however,
are clearly seen around tails of the PSFs, whose contributions are about 30% of
the total power. All FIS functions are operating well in orbit, and its
performance meets the laboratory characterizations, except for the two longer
wavelength bands, which are not performing as well as characterized.
Furthermore, the FIS has a spectroscopic capability using a Fourier transform
spectrometer (FTS). Because the FTS takes advantage of the optics and detectors
of the photometer, it can simultaneously make a spectral map. This paper
summarizes the in-flight technical and operational performance of the FIS.


title:
The Struve-Sahade effect in the optical spectra of O-type binaries I.
  Main-sequence systems

abstract:
  We present a spectroscopic analysis of four massive binary systems that are
known or are good candidates to display the Struve-Sahade effect (defined as
the apparent strengthening of the secondary spectrum of the binary when the
star is approaching, and the corresponding weakening of the lines when it is
receding).
  We use high resolution optical spectra to determine new orbital solutions and
spectral types of HD 165052, HD 100213, HD 159176 and DH Cep. As good knowledge
of the fundamental parameters of the considered systems is necessary to examine
the Struve-Sahade effect. We then study equivalent width variations in the
lines of both components of these binaries during their orbital cycle.
  In the case of these four systems, variations appear in the equivalent widths
of some lines during the orbital cycle, but the definition given above can any
longer be valid, since it is now clear that the effect modifies the primary
spectrum as much as the secondary spectrum. Furthermore, the lines affected,
and the way in which they are affected, depend on the considered system. For at
least two of them (HD 100213 and HD 159176) these variations probably reflect
the ellipsoidal variable nature of the system.


title: Ihara's lemma for imaginary quadratic fields

abstract:
  An analogue over imaginary quadratic fields of a result in algebraic number
theory known as Ihara's lemma is established. More precisely, we show that for
a prime ideal P of the ring of integers of an imaginary quadratic field F, the
kernel of the sum of the two standard P-degeneracy maps between the cuspidal
sheaf cohomology H^1_!(X_0, M_0)^2 --> H^1_!(X_1, M_1) is Eisenstein. Here X_0
and X_1 are analogues over F of the modular curves X_0(N) and X_0(Np),
respectively. To prove our theorem we use the method of modular symbols and the
congruence subgroup property for the group SL(2) which is due to Serre.


title:
On the measurement of B(E2, 0+ -> 2+) using intermediate-energy Coulomb
  excitation

abstract:
  Coulomb excitation is a standard method used to extract quadrupole excitation
strengths of even-even nuclei. In typical analyses the reaction is assumed to
be one-step, Coulomb only, and is treated within a semi-classical model. In
this work, fully-quantal coupled-channel calculations are performed for three
test cases in order to determine the importance of multi-step effects, nuclear
contributions, feeding from other states and corrections to the semi-classical
approximation. We study the excitation of 30S, 58Ni and 78Kr on 197Au at ~ 50
AMeV. We find that nuclear effects may contribute more than 10% and that
feeding contributions can be larger than 15%. These corrections do not alter
significantly the published B(E2) values, however an additional theoretical
error of up to 13% should be added to the experimental uncertainty if the
semi-classical model is used. This theoretical error is reduced to less than 7%
when performing a quantal coupled-channel analysis.


title: Exciting Maser Science with New Instruments - the Promise of the EVLA

abstract:
  In the near future, the Expanded Very Large Array (EVLA) will allow surveys
for maser sources with unprecedented sensitivity, spectral coverage and
spectroscopic capabilities. In particular, comprehensive surveys for many maser
species with simultaneous sensitive continuum imaging and absorption studies
will give a comprehensive radio picture of star formation in the Galactic plane
and elsewhere. Very efficient EVLA surveys for H2O megamasers in Active Galacic
Nuclei will be possible to practically arbitrary redshifts.
  EVLA and Atacama Large Millimeter Array (ALMA) studies of H2O and SiO masers
will serve as high resolution probes of the innermost envelopes of oxygen-rich
evolved stars and HCN masers of carbon-rich stars.
  Farther in the future, the Square Kilometer Array (SKA) promises the
detection of OH gigamasers at all conceivable redshifts and maser astrometry
with unprecedented accuracy.


title: BMW algebra, quantized coordinate algebra and type C Schur--Weyl duality

abstract:
  We prove an integral version of the Schur--Weyl duality between the
specialized Birman--Murakami--Wenzl algebra $B_n(-q^{2m+1},q)$ and the quantum
algebra associated to the symplectic Lie algebra sp_{2m}. In particular, we
deduce that this Schur--Weyl duality holds over arbitrary (commutative) ground
rings, which answers a question of Lehrer and Zhang [Strongly multiplicity free
modules for Lie algebras and quantum groups, J. Algebra (1) 306 (2006),
138--174] in the symplectic case. As a byproduct, we show that, as
$Z[q,q^{-1}]$-algebra, the quantized coordinate algebra defined by Kashiwara is
isomorphic to the quantized coordinate algebra arising from a generalized
Faddeev--Reshetikhin--Takhtajan's construction.


title: Prospects of Open Charm Production at GSI-FAIR and J-PARC

abstract:
  We present a detailed phenomenological study of the prospects of open charm
physics at the future $\bar{p}p$ and $pp$ facilities GSI-FAIR and J-PARC,
respectively. In particular, we concentrate on differential cross sections and
the charge and longitudinal double-spin asymmetries at next-to-leading order
accuracy. Theoretical uncertainties for the proposed observables are estimated
by varying the charm quark mass and the renormalization and factorization
scales.


title: The design and performance of the ZEUS Micro Vertex detector

abstract:
  In order to extend the tracking acceptance, to improve the primary and
secondary vertex reconstruction and thus enhancing the tagging capabilities for
short lived particles, the ZEUS experiment at the HERA Collider at DESY
installed a silicon strip vertex detector. The barrel part of the detector is a
63 cm long cylinder with silicon sensors arranged around an elliptical
beampipe. The forward part consists of four circular shaped disks. In total
just over 200k channels are read out using $2.9 {\rm m^2}$ of silicon. In this
report a detailed overview of the design and construction of the detector is
given and the performance of the completed system is reviewed.


title: Perturbation Expansion for Option Pricing with Stochastic Volatility

abstract:
  We fit the volatility fluctuations of the S&P 500 index well by a Chi
distribution, and the distribution of log-returns by a corresponding
superposition of Gaussian distributions. The Fourier transform of this is,
remarkably, of the Tsallis type. An option pricing formula is derived from the
same superposition of Black-Scholes expressions. An explicit analytic formula
is deduced from a perturbation expansion around a Black-Scholes formula with
the mean volatility. The expansion has two parts. The first takes into account
the non-Gaussian character of the stock-fluctuations and is organized by powers
of the excess kurtosis, the second is contract based, and is organized by the
moments of moneyness of the option. With this expansion we show that for the
Dow Jones Euro Stoxx 50 option data, a Delta-hedging strategy is close to being
optimal.

categories: q-fin.PR cond-mat.stat-mech math-ph math.MP physics.data-an physics.soc-ph


title: Bayesian segmentation of hyperspectral images

abstract:
  In this paper we consider the problem of joint segmentation of hyperspectral
images in the Bayesian framework. The proposed approach is based on a Hidden
Markov Modeling (HMM) of the images with common segmentation, or equivalently
with common hidden classification label variables which is modeled by a Potts
Markov Random Field. We introduce an appropriate Markov Chain Monte Carlo
(MCMC) algorithm to implement the method and show some simulation results.


title: Explicit formulas for efficient multiplication in F_{3^{6m}}

abstract:
  Efficient computation of the Tate pairing is an important part of
pairing-based cryptography. Recently with the introduction of the Duursma-Lee
method special attention has been given to the fields of characteristic 3.
Especially multiplication in F_{3^{6m}}, where m is prime, is an important
operation in the above method. In this paper we propose a new method to reduce
the number of F_{3^m} multiplications for multiplication in F_{3^{6m}} from 18
in recent implementations to 15. The method is based on the fast Fourier
tranmsform and explicit formulas are given. The execution times of our software
implementations for F_{3^{6m}} show the efficiency of our results.


title:
Decreasing elliptic flow at the LHC: Calculations in a parton
  recombination approach

abstract:
  We apply the parton recombination approach to study the energy dependence of
the elliptic flow, v_2 in heavy ion collisions from AGS to LHC energies. The
relevant input quantities ($T, \mu_B, \eta_T$) at the various center of mass
energies are obtained from fits to the available data. The model yields a good
description of the integrated v_2 data for charged particles at midrapidity
from AGS to RHIC energies. In stark contrast to the current expectations, we
observe a decrease of the integrated v_2 values above the highest RHIC energy.
Thus, we predict a decrease of v_2 at LHC energies compared to the RHIC
results. This drop is attributed to negative v_2 values for the underlying
parton distributions at low to moderate transverse momenta that develops if the
transverse flow velocity is high enough. At energies above the LHC regime, the
present approach predicts even negative values for the integrated v_2.


title: Star and Planet Formation with ALMA: an Overview

abstract:
  Submillimeter observations with ALMA will be the essential next step in our
understanding of how stars and planets form. Key projects range from detailed
imaging of the collapse of pre-stellar cores and measuring the accretion rate
of matter onto deeply embedded protostars, to unravelling the chemistry and
dynamics of high-mass star-forming clusters and high-spatial resolution studies
of protoplanetary disks down to the 1 AU scale.


title: Black Holes and Quantum Gravity at the LHC

abstract:
  We argue that the highly studied black hole signatures based on thermal
multiparticle final states are very unlikely and only occur in a very limited
parameter regime if at all. However, we show that if the higher-dimensional
quantum gravity scale is low, it should be possible to study quantum gravity in
the context of higher dimensions through detailed compositeness-type searches.


title:
Multiphase Plasma in Sub-Damped Lyman Alpha Systems: A Hidden Metal
  Reservoir

abstract:
  We present a VLT/UVES spectrum of a proximate sub-damped Lyman-alpha
(sub-DLA) system at z=2.65618 toward the quasar Q0331-4505
(z_qso=2.6785+/-0.0030). Absorption lines of O I, Si II, Si III, Si IV, C II, C
III, C IV, Fe II, Al II, and O VI are seen in the sub-DLA, which has a neutral
hydrogen column density log N(H I)=19.82+/-0.05. The absorber is at a velocity
of 1820+/-250 km/s from the quasar; however, its low metallicity
[O/H]=-1.64+/-0.07, lack of partial coverage, lack of temporal variations
between observations taken in 2003 and 2006, and non-detection of N V imply the
absorber is not a genuine intrinsic system. By measuring the O VI column
density and assuming equal metallicities in the neutral and ionized gas, we
determine the column density of hot ionized hydrogen in this sub-DLA, and in
two other sub-DLAs with O VI drawn from the literature. Coupling this with
determinations of the typical amount of warm ionized hydrogen in sub-DLAs, we
confirm that sub-DLAs are a more important metal reservoir than DLAs, in total
comprising at least 6-22% of the metal budget at z~2.5.


title:
Single-Symbol ML Decodable Distributed STBCs for Partially-Coherent
  Cooperative Networks

abstract:
  Space-time block codes (STBCs) that are single-symbol decodable (SSD) in a
co-located multiple antenna setting need not be SSD in a distributed
cooperative communication setting. A relay network with N relays and a single
source-destination pair is called a partially-coherent relay channel (PCRC) if
the destination has perfect channel state information (CSI) of all the channels
and the relays have only the phase information of the source-to-relay channels.
In this paper, first, a new set of necessary and sufficient conditions for a
STBC to be SSD for co-located multiple antenna communication is obtained. Then,
this is extended to a set of necessary and sufficient conditions for a
distributed STBC (DSTBC) to be SSD for a PCRC, by identifying the additional
conditions. Using this, several SSD DSTBCs for PCRC are identified among the
known classes of STBCs. It is proved that even if a SSD STBC for a co-located
MIMO channel does not satisfy the additional conditions for the code to be SSD
for a PCRC, single-symbol decoding of it in a PCRC gives full-diversity and
only coding gain is lost. It is shown that when a DSTBC is SSD for a PCRC, then
arbitrary coordinate interleaving of the in-phase and quadrature-phase
components of the variables does not disturb its SSD property for PCRC.
Finally, it is shown that the possibility of {\em channel phase compensation}
operation at the relay nodes using partial CSI at the relays increases the
possible rate of SSD DSTBCs from $\frac{2}{N}$ when the relays do not have CSI
to 1/2, which is independent of N.


title:
The short period end of the contact binary period distribution based on
  the All Sky Automated Survey (ASAS)

abstract:
  The search-volume corrected period distribution of contact binaries of the W
UMa type appears to reflect primarily the constant number ratio of ~1/500 to
the number of stars along the Main Sequence; there exist no evidence for
angular momentum evolution. The maximum in contact binary numbers is located at
shorter periods than estimated before, P ~ 0.27 d. The drop in numbers towards
the cut-off at P ~ 0.215 - 0.22 d still suffers from the small number
statistics while the cut-off itself remains unexplained. Only one out of seven
short-period ASAS variables with P<0.22 d have been retained in the sample
considered here within 8 < V < 13; this short-period field-sky record holder at
P=0.2178 d should be studied.


title: Discovery of VHE gamma-rays from the distant BL Lac 1ES 0347-121

abstract:
  Aims: Our aim is to study the production mechanism for very-high-energy (VHE;
>100GeV) gamma-rays in distant active galactic nuclei (AGN) and use the
observed VHE spectrum to derive limits on the Extragalactic Background Light
(EBL). We also want to determine physical quantities through the modeling of
the object's broad-band spectral energy distribution (SED). Methods: VHE
observations (~25h live time) of the BL Lac 1ES 0347-121 (redshift z=0.188)
were conducted with the High Energy Stereoscopic System (H.E.S.S.) between
August and December 2006. Contemporaneous X-ray and UV/optical observations
from the SWIFT satellite are used to interpret the SED of the source in terms
of a synchrotron self Compton (SSC) model. Results: An excess of 327 events,
corresponding to a statistical significance of 10.1 standard deviations, is
detected from 1ES 0347-121. Its photon spectrum, ranging from ~250GeV to ~3TeV,
is well described by a power law with a photon index of Gamma = 3.10 +/-
0.23_stat +/- 0.10_sys. The integral flux above 250GeV corresponds to ~2% of
the flux of the Crab Nebula above the same threshold. No VHE flux variability
is detected within the data set. Conclusions: Constraints on the EBL density at
optical to near-infrared wavelengths derived from the photon spectrum of 1ES
0347-121 are close to the strongest limits derived previously. The strong EBL
limits confirm earlier findings, that the EBL density in the near-infrared is
close to the lower limits from source counts. This implies that the universe is
more transparent to VHE gamma-rays than previously believed. An SSC model
provides a reasonable description of the contemporaneous SED.


title: Efficient FPGA-based multipliers for F_{3^97} and F_{3^{6*97}}

abstract:
  In this work we present a new structure for multiplication in finite fields.
This structure is based on a digit-level LFSR (Linear Feedback Shift Register)
multiplier in which the area of digit-multipliers are reduced using the
Karatsuba method. We compare our results with the other works in the literature
for F_{3^97}. We also propose new formulas for multiplication in F_{3^{6*97}}.
These new formulas reduce the number of F_{3^97}-multiplications from 18 to 15.
The fields F_{3^{97}} and F_{3^{6*97}} are relevant in the context of
pairing-based cryptography.


title:
Fine frequency shift of sigle vortex entrance and exit in
  superconducting loops

abstract:
  The heat capacity $C_{p}$ of an array of independent aluminum rings has been
measured under an external magnetic field $\vec{H}$ using highly sensitive
ac-calorimetry based on a silicon membrane sensor. Each superconducting vortex
entrance induces a phase transition and a heat capacity jump and hence $C_{p}$
oscillates with $\vec{H}$. This oscillatory and non-stationary behaviour
measured versus the magnetic field has been studied using the Wigner-Ville
distribution (a time-frequency representation). It is found that the
periodicity of the heat capacity oscillations varies significantly with the
magnetic field; the evolution of the period also depends on the sweeping
direction of the field. This can be attributed to a different behavior between
expulsion and penetration of vortices into the rings. A variation of more than
15% of the periodicity of the heat capacity jumps is observed as the magnetic
field is varied. A description of this phenomenon is given using an analytical
solution of the Ginzburg-Landau equations of superconductivity.


title:
Pump-Probe Experiments on the Single-Molecule Magnet Fe8 : Measurement
  of Excited Level Lifetimes

abstract:
  We present magnetization measurements on the single molecule magnet Fe8 in
the presence of pulsed microwave radiation. A pump-probe technique is used with
two microwave pulses with frequencies of 107 GHz and 118 GHz and pulse lengths
of several nanoseconds to study the spin dynamics via time-resolved
magnetization measurements using a Hall probe magnetometer. We find evidence
for short spin-phonon relaxation times of the order of one microsecond. The
temperature dependence of the spin-phonon relaxation time in our experiments is
in good agreement with previously published theoretical results. We also
established the presence of very short energy diffusion times, that act on a
timescale of about 70 ns.


title: The Green's function and the Ahlfors map

abstract:
  The classical Green's function associated to a simply connected domain in the
complex plane is easily expressed in terms of a Riemann mapping function. The
purpose of this paper is to express the Green's function of a finitely
connected domain in the plane in terms of a single Ahlfors mapping of the
domain, which is a proper holomorphic mapping of the domain onto the unit disc
that is the analogue of the Riemann map in the multiply connected setting.


title: Controlling the Ratchet Effect for Cold Atoms

abstract:
  Low-order quantum resonances manifested by directed currents have been
realized with cold atoms. Here we show that by increasing the strength of an
experimentally achievable delta-kicking ratchet potential, quantum resonances
of a very high order may naturally emerge and can induce larger ratchet
currents than low-order resonances, with the underlying classical limit being
fully chaotic. The results offer a means of controlling quantum transport of
cold atoms.


title:
Free 3-distributions: holonomy, Fefferman constructions and dual
  distributions

abstract:
  This paper analyses the parabolic geometries generated by a free
3-distribution in the tangent space of a manifold. It shows the existence of
normal Fefferman constructions over CR and Lagrangian contact structures
corresponding to holonomy reductions to SO(4,2) and SO(3,3), respectively.
There is also a fascinating construction of a `dual' distribution when the
holonomy reduces to $G_2'$. The paper concludes with some holonomy
constructions for free $n$-distributions for $n>3$.


title: Boundary three-point function on AdS2 D-branes

abstract:
  Using the H3+-Liouville relation, I explicitly compute the boundary
three-point function on AdS2 D-branes in H3+, and check that it exhibits the
expected symmetry properties and has the correct geometrical limit. I then find
a simple relation between this boundary three-point function and certain fusing
matrix elements, which suggests a formal correspondence between the AdS2
D-branes and discrete representations of the symmetry group. Concluding
speculations deal with the fuzzy geometry of AdS2 D-branes, strings in the
Minkowskian AdS3, and the hypothetical existence of new D-branes in H3+.


title:
Interplay between field-induced and frustration-induced quantum
  criticalities in the frustrated two-leg Heisenberg ladder

abstract:
  The antiferromagnetic Heisenberg two-leg ladder in the presence of
frustration and an external magnetic field is a system that is characterized by
two sorts of quantum criticalities, not only one. One criticality is the
consequence of intrinsic frustration, and the other one is a result of the
external magnetic field. So the behaviour of each of them in the presence of
the other deserves to be studied. Using the Jordan-Wigner transformation in
dimensions higher than one and bond-mean-field theory we examine the interplay
between the field-induced and frustration-induced quantum criticalities in this
system. The present work could constitute a prototype for those systems showing
multiple, perhaps sometimes competing, quantum criticalities. We calculate
several physical quantities like the magnetization and spin susceptibility as
functions of field and temperature.


title: QCD sum rules study of \Xi_c and \Xi_b baryons

abstract:
  We use QCD sum rules to study the masses of the baryons $\Xi_c$ and $\Xi_b$.
We work with a current where the strange and the light quarks are in a relative
spin zero, at leading order in $\alpha_s$. We consider the contributions of
condensates up to dimension six. For $\Xi_b$ we get $m_{\Xi_{b}}= (5.75\pm
0.25) {\rm GeV}$, and for $\Xi_c$ we get $m_{\Xi_{c}}= (2.5\pm 0.2) {\rm GeV}$,
both in excelent agreement with the experimental values. We also make
predictions to the state $\Omega_b(ssb)$ obtaining m_{\Omega_{b}}= (5.82\pm
0.23) GeV.


title:
Bounds to binding energies from the concavity of thermodynamical
  functions

abstract:
  Sequences of experimental ground-state energies are mapped onto concave
patterns cured from convexities due to pairing and/or shell effects. The same
patterns, completed by a list of excitation energies, can be used to give
numerical estimates of the grand potential $\Omega(\beta,\mu)$ for a mixture of
nuclei at low or moderate temperatures $T=\beta^{-1}$ and at many chemical
potentials $\mu.$ The average nucleon number $<{\bf A} >(\beta,\mu)$ then
becomes a continuous variable, allowing extrapolations towards nuclear masses
closer to drip lines. We study the possible concavity of several
thermodynamical functions, such as the free energy and the average energy, as
functions of $<{\bf A} >.$ Concavity, when present in such functions, allows
trivial interpolations and extrapolations providing upper and lower bounds,
respectively, to binding energies. Such bounds define an error bar for the
prediction of binding energies. An extrapolation scheme for such concave
functions is tested. We conclude with numerical estimates of the binding
energies of a few nuclei closer to drip lines.


title: Charged Black Holes on DGP Brane

abstract:
  We consider charged black holes localized on a three-brane in the DGP model.
With a spherically symmetric metric ansatz on the brane and assuming a
Z_2-symmetry across the brane, we find two types of solutions which correspond
to the so-called regular and accelerated branches in the DGP model. When the
charge of the black hole vanishes, our solutions agree with the Schwarzschild
solutions obtained by Gabadadze and Iglesias.


title:
Osculating orbits in Schwarzschild spacetime, with an application to
  extreme mass-ratio inspirals

abstract:
  We present a method to integrate the equations of motion that govern bound,
accelerated orbits in Schwarzschild spacetime. At each instant the true
worldline is assumed to lie tangent to a reference geodesic, called an
osculating orbit, such that the worldline evolves smoothly from one such
geodesic to the next. Because a geodesic is uniquely identified by a set of
constant orbital elements, the transition between osculating orbits corresponds
to an evolution of the elements. In this paper we derive the evolution
equations for a convenient set of orbital elements, assuming that the force
acts only within the orbital plane; this is the only restriction that we impose
on the formalism, and we do not assume that the force must be small. As an
application of our method, we analyze the relative motion of two massive
bodies, assuming that one body is much smaller than the other. Using the hybrid
Schwarzschild/post-Newtonian equations of motion formulated by Kidder, Will,
and Wiseman, we treat the unperturbed motion as geodesic in a Schwarzschild
spacetime whose mass parameter is equal to the system's total mass. The force
then consists of terms that depend on the system's reduced mass. We highlight
the importance of conservative terms in this force, which cause significant
long-term changes in the time-dependence and phase of the relative orbit. From
our results we infer some general limitations of the radiative approximation to
the gravitational self-force, which uses only the dissipative terms in the
force.


title: Dust formation in electric arc furnace : birth of the particles

abstract:
  The characterization of Electric Arc Furnace (EAF) dust shows that bubble
burst at the liquid steel surface is the principal source of dust emission. We
have therefore developed an experimental device for studying this phenomenon.
As in the case of the air-water system, the bubble-burst gives birth to two
types of droplets: film drops and jet drops. The jet drop formation is observed
with high-speed video. The film drop aerosol is collected on filters and then
characterized by means of SEM, granulometric and gravimetric analyses. Results
are presented and discussed. The quantification of both types of projections
leads to the conclusion that the film drop projections represent the major
source of dust. The amount of film drops greatly decreases with the parent
bubble size. Under 4.5 mm in bubble diameter, no film drops are formed.
Decreasing enough the bubble size would therefore represent an effective
solution for reducing drastically the EAF dust emission.


title:
Topology effects on the heat capacity of mesoscopic superconducting
  disks

abstract:
  Phase transitions in superconducting mesoscopic disks have been studied over
the H-T phase diagram through heat capacity measurement of an array of
independent aluminium disks. These disks exhibit non periodic modulations
versus H of the height of the heat capacity jump at the superconducting to
normal transition. This behaviour is attributed to giant vortex states
characterized by their vorticity L. A crossover from a bulk-like to a
mesoscopic behaviour is demonstrated. $C_{\rm p}$ versus H plots exhibit
cascades of phase transitions as L increases or decreases by one unity, with a
strong hysteresis. Phase diagrams of giant vortex states inside the
superconducting region are drawn in the vortex penetration and expulsion
regimes and phase transitions driven by temperature between vortex states are
thus predicted in the zero field cooled regime before being experimentally
evidenced.


title: On the algebraic classification of K-local spectra

abstract:
  In 1996, Jens Franke proved the equivalence of certain triangulated
categories possessing an Adams spectral sequence. One particular application of
this theorem is that the K_(p)-local stable homotopy category at an odd prime
can be described as the derived category of an abelian category. We explain
this proof from a topologist's point of view.


title:
Multi-scale analysis of the electromagnetic self-force in a weak
  gravitational field

abstract:
  We examine the motion of a charged particle in a weak gravitational field. In
addition to the Newtonian gravity exerted by a large central body, the particle
is subjected to an electromagnetic self-force that contains both a conservative
piece and a radiation-reaction piece. This toy problem shares many of the
features of the strong-field gravitational self-force problem, and it is
sufficiently simple that it can be solved exactly with numerical methods, and
approximately with analytical methods. We submit the equations of motion to a
multi-scale analysis, and we examine the roles of the conservative and
radiation-reaction pieces of the self-force. We show that the
radiation-reaction force drives secular changes in the orbit's semilatus rectum
and eccentricity, while the conservative force drives a secular regression of
the periapsis and affects the orbital time function; neglect of the
conservative term can hence give rise to an important phasing error. We next
examine what might be required in the formulation of a reliable adiabatic
approximation for the orbital evolution; this would capture all secular changes
in the orbit and discard all irrelevant oscillations. We conclude that such an
approximation would be very difficult to formulate without prior knowledge of
the exact solution.


title: f(R) Gravity with Torsion: The Metric-Affine Approach

abstract:
  The role of torsion in f(R) gravity is considered in the framework of
metric-affine formalism. We discuss the field equations in empty space and in
presence of perfect fluid matter taking into account the analogy with the
Palatini formalism. As a result, the extra curvature and torsion degrees of
freedom can be dealt as an effective scalar field of fully geometric origin.
  From a cosmological point of view, such a geometric description could account
for the whole Dark Side of the Universe.


title:
Exact Solution of Strongly Interacting Quasi-One-Dimensional Spinor Bose
  Gases

abstract:
  We present an exact analytical solution of the fundamental system of
quasi-one-dimensional spin-1 bosons with infinite delta-repulsion. The
eigenfunctions are constructed from the wave functions of non-interacting
spinless fermions, based on Girardeau's Fermi-Bose mapping, and from the wave
functions of distinguishable spins. We show that the spinor bosons behave like
a compound of non-interacting spinless fermions and non-interacting
distinguishable spins. This duality is especially reflected in the spin
densities and the energy spectrum. We find that the momentum distribution of
the eigenstates depends on the symmetry of the spin function. Furthermore, we
discuss the splitting of the ground state multiplet in the regime of large but
finite repulsion.


title: The evolution of stars in the Taurus-Auriga T association

abstract:
  In a recent study, individual parallaxes were determined for many stars of
the Taurus-Auriga T association that are members of the same moving group. We
use these new parallaxes to re-address the issue of the relationship between
classical T Tauri stars (CTTSs) and weak-emission line T Tauri stars (WTTSs).
With the available spectroscopic and photometric information for 72 individual
stars or stellar systems among the Taurus-Auriga objects with known parallaxes,
we derived reliable photospheric luminosities, mainly from the Ic magnitude of
these objects. We then studied the mass and age distributions of the stellar
sample, using pre-main sequence evolutionary models to determine the basic
properties of the stellar sample. Statistical tests and Monte Carlo simulations
were then applied to studying the properties of the two T Tauri subclasses. We
find that the probability of CTTS and WTTS samples being drawn from the same
parental age and mass distributions is low; CTTSs are, on average, younger than
WTTSs. They are also less massive, but this is due to selection effects. The
observed mass and age distributions of both T Tauri subclasses can be
understood in the framework of a simple disk evolution model, assuming that the
CTTSs evolve into WTTSs when their disks are fully accreted by the stars.
According to this empirical model, the average disk lifetime in Taurus-Auriga
is 4 10**6 (Mstar/Msun)**0.75 yr.


title:
Convergence Rate of K-Step Maximum Likelihood Estimate in Semiparametric
  Models

abstract:
  We suggest an iterative approach to computing K-step maximum likelihood
estimates (MLE) of the parametric components in semiparametric models based on
their profile likelihoods. The higher order convergence rate of K-step MLE
mainly depends on the precision of its initial estimate and the convergence
rate of the nuisance functional parameter in the semiparametric model.
Moreover, we can show that the K-step MLE is as asymptotically efficient as the
regular MLE after a finite number of iterative steps. Our theory is verified
for several specific semiparametric models. Simulation studies are also
presented to support these theoretical results.


abstract: Neutron channelling in a magnetic tube trap is discussed


title: The dark nature of GRB 051022 and its host galaxy

abstract:
  We present multiwavelength (X-ray/optical/near-infrared/millimetre)
observations of GRB 051022 between 2.5 hours and ~1.15 yr after the event. It
is the most intense gamma-ray burst (~ 10^-4 erg cm^-2) detected by HETE-2,
with the exception of the nearby GRB 030329. Optical and near infrared
observations did not detect the afterglow despite a strong afterglow at X-ray
wavelengths. Millimetre observations at Plateau de Bure (PdB) detected a source
and a flare, confirming the association of this event with a moderately bright
(R = 21.5) galaxy. Spectroscopic observations of this galaxy show strong [O
II], Hbeta and [O III] emission lines at a redshift of 0.809. The spectral
energy distribution of the galaxy implies Av (rest frame) = 1.0 and a starburst
occuring ~ 25 Myr ago, during which the star-forming-rate reached >= 25
Msun/yr. In conjunction with the spatial extent (~ 1'') it suggests a very
luminous (Mv = - 21.8) blue compact galaxy, for which we also find with Z Zsun.
The X-ray spectrum shows evidence of considerable absorption by neutral gas
with NH, X-ray = 3.47(+0.48/-0.47) x 10^22 cm^-2 (rest frame). Absorption by
dust in the host galaxy at z = 0.809 certainly cannot account for the
non-detection of the optical afterglow, unless the dust-to-gas ratio is quite
different than that seen in our Galaxy (i.e. large dust grains). It is likely
that the afterglow of the dark GRB 051022 was extinguished along the line of
sight by an obscured, dense star forming region in a molecular cloud within the
parent host galaxy. This galaxy is different from most GRB hosts being brighter
than L* by a factor of 3. We have also derived a SFR ~ 50 Msun/yr and predict
that this host galaxy will be detected at sub-mm wavelengths.


title:
Nondegenerate 3D complex Euclidean superintegrable systems and algebraic
  varieties

abstract:
  A classical (or quantum) second order superintegrable system is an integrable
n-dimensional Hamiltonian system with potential that admits 2n-1 functionally
independent second order constants of the motion polynomial in the momenta, the
maximum possible. Such systems have remarkable properties: multi-integrability
and multi-separability, an algebra of higher order symmetries whose
representation theory yields spectral information about the Schroedinger
operator, deep connections with special functions and with QES systems. Here we
announce a complete classification of nondegenerate (i.e., 4-parameter)
potentials for complex Euclidean 3-space. We characterize the possible
superintegrable systems as points on an algebraic variety in 10 variables
subject to six quadratic polynomial constraints. The Euclidean group acts on
the variety such that two points determine the same superintegrable system if
and only if they lie on the same leaf of the foliation. There are exactly 10
nondegenerate potentials.


title: From the BRST invariant Hamiltonian to the Field-Antifield Formalism

abstract:
  We study the relation between the lagrangian field-antifield formalism and
the BRST invariant phase space formulation of gauge theories. Starting from the
Batalin-Fradkin-Vilkovisky unitarized action, we demonstrate in a deductive way
the equivalence of the phase space, and the lagrangian field-antifield
partition functions for the case of irreducible first rank theories.


title:
Metric fluctuations of an evaporating black hole from back reaction of
  stress tensor fluctuations

abstract:
  This paper delineates the first steps in a systematic quantitative study of
the spacetime fluctuations induced by quantum fields in an evaporating black
hole under the stochastic gravity program. The central object of interest is
the noise kernel, which is the symmetrized two-point quantum correlation
function of the stress tensor operator. As a concrete example we apply it to
the study of the spherically-symmetric sector of metric perturbations around an
evaporating black hole background geometry. For macroscopic black holes we find
that those fluctuations grow and eventually become important when considering
sufficiently long periods of time (of the order of the evaporation time), but
well before the Planckian regime is reached. In addition, the assumption of a
simple correlation between the fluctuations of the energy flux crossing the
horizon and far from it, which was made in earlier work on
spherically-symmetric induced fluctuations, is carefully scrutinized and found
to be invalid. Our analysis suggests the existence of an infinite amplitude for
the fluctuations when trying to localize the horizon as a three-dimensional
hypersurface, as in the classical case, and, as a consequence, a more accurate
picture of the horizon as possessing a finite effective width due to quantum
fluctuations. This is supported by a systematic analysis of the noise kernel in
curved spacetime smeared with different functions under different conditions,
the details are collected in the appendices. This case study shows a pathway
for probing quantum metric fluctuations near the horizon and understanding
their physical meaning.


title:
High energy neutrino yields from astrophysical sources II: Magnetized
  sources

abstract:
  We calculate the yield of high energy neutrinos produced in astrophysical
sources for arbitrary interaction depths $\tau_0$ and magnetic field strengths
$B$. We take into account energy loss processes like synchrotron radiation and
diffusion of charged particles in turbulent magnetic fields as well as the
scattering of secondaries on background photons and the direct production of
charm neutrinos. Meson-photon interactions are simulated with an extended
version of the SOPHIA model. Diffusion leads to an increased path-length before
protons leave the source of size R_s and therefore magnetized sources lose
their transparency below the energy $E\sim 10^{18}{\rm eV} (R_s/{\rm pc})
(B/{\rm mG}) \tau_0^{1/\alpha}$, with $\alpha=1/3$ and 1 for Kolmogorov and
Bohm diffusion, respectively. Moreover, the neutrino flux is suppressed above
the energy where synchrotron energy losses become important for charged
particles. As a consequence, the energy spectrum and the flavor composition of
neutrinos are strongly modified both at low and high energies even for sources
with $\tau_0\lsim 1$.


title: Identifying Small Mean Reverting Portfolios

abstract:
  Given multivariate time series, we study the problem of forming portfolios
with maximum mean reversion while constraining the number of assets in these
portfolios. We show that it can be formulated as a sparse canonical correlation
analysis and study various algorithms to solve the corresponding sparse
generalized eigenvalue problems. After discussing penalized parameter
estimation procedures, we study the sparsity versus predictability tradeoff and
the impact of predictability in various markets.


title: Photoabsorption in a plasma in a high magnetic field

abstract:
  Photo-absorption in fully ionized plasmas in high magnetic fields is
re-examined, using the methods of many-body quantum field theory. For
frequencies in the immediate vicinity of the electron cyclotron resonance the
rates we obtain disagree markedly from those in the literature. The new element
in our work that causes most of the disagreement is the inclusion of the lowest
order real part of the energy-shift of the resonant state, where, in effect,
previous authors had included only the imaginary part. In a region around and
below the proton cyclotron resonance our results also disagree with those of
previous authors, for a number of reasons.


title:
Entangled-like Chain Dynamics in Non-entangled Polymer Blends with Large
  Dynamic Asymmetry

abstract:
  We discuss simulations of a simple model for polymer blends in the framework
of the Rouse model. At odds with standard predictions, large dynamic asymmetry
between the two components induces strong non-exponentiality of the Rouse modes
for the fast component. Despite chains being much shorter than the entanglement
length, it also induces dynamic features resembling a crossover to
entangled-like chain dynamics. This unusual behavior is associated to strong
memory effects which break down the assumption of time uncorrelation of the
external forces acting on the tagged chain.


title: Topological Higher Gauge Theory - from BF to BFCG theory

abstract:
  We study generalizations of 3- and 4-dimensional BF-theory in the context of
higher gauge theory. First, we construct topological higher gauge theories as
discrete state sum models and explain how they are related to the state sums of
Yetter, Mackaay, and Porter. Under certain conditions, we can present their
corresponding continuum counterparts in terms of classical Lagrangians. We then
explain that two of these models are already familiar from the literature: the
SigmaPhiEA-model of 3-dimensional gravity coupled to topological matter, and
also a 4-dimensional model of BF-theory coupled to topological matter.


title: Studying the MSSM Higgs sector by forward proton tagging at the LHC

abstract:
  We show that the use of forward proton detectors at the LHC installed at 220
m and 420 m distance around ATLAS and / or CMS can provide important
information on the Higgs sector of the MSSM. We analyse central exclusive
production of the neutral CP-even Higgs bosons h and H and their decays into
bottom quarks, tau leptons and W bosons in different MSSM benchmark scenarios.
Using plausible estimates for the achievable experimental efficiencies and the
relevant background processes, we find that the prospective sensitivity of the
diffractive Higgs production will allow to probe interesting regions of the
M_A--tan_beta parameter plane of the MSSM. Central exclusive production of the
CP-even Higgs bosons of the MSSM may provide a unique opportunity to access the
bottom Yukawa couplings of the Higgs bosons up to masses of M_H \lsim 250 GeV.
We also discuss the prospects for identifying the CP-odd Higgs boson, A, in
diffractive processes at the LHC.


title: Stability conditions on generic complex tori

abstract:
  In this paper we describe a simply connected component of the complex
manifold of stability conditions on the bounded derived category of a generic
complex torus of any dimension. A torus is called generic if there are no
nontrivial integral (p,p)-classes. We give an explicit description of all
stability conditions in that connected component.


title: Numerical Simulations of HH 555

abstract:
  We present 3D gasdynamic simulations of the Herbig Haro object HH 555. HH 555
is a bipolar jet emerging from the tip of an elephant trunk entering the
Pelican Nebula from the adjacent molecular cloud. Both beams of HH 555 are
curved away from the center of the H II region. This indicates that they are
being deflected by a side-wind probably coming from a star located inside the
nebula or by the expansion of the nebula itself. HH 555 is most likely an
irradiated jet emerging from a highly embedded protostar, which has not yet
been detected.
  In our simulations we vary the incident photon flux, which in one of our
models is equal to the flux coming from a star 1 pc away emitting 5x10^48
ionizing (i. e., with energies above the H Lyman limit) photons per second. An
external, plane-parallel flow (a ``side-wind'') is coming from the same
direction as the photoionizing flux. We have made four simulations, decreasing
the photon flux by a factor of 10 in each simulation. We discuss the properties
of the flow and we compute Halpha emission maps (integrated along lines of
sight).
  We show that the level of the incident photon flux has an important influence
on the shape and visibility of the jet. If the flux is very high, it causes a
strong evaporation of the neutral clump, producing a photoevaporated wind
traveling in the direction opposite to the incident flow. The interaction of
the two flows creates a double shock ``working surface'' around the clump
protecting it and the jet from the external flow. The jet only starts to curve
when it penetrates through the working surface.


title: Fourier transform on locally compact quantum groups

abstract:
  The notion of Fourier transform is among the more important tools in
analysis, which has been generalized in abstract harmonic analysis to the level
of abelian locally compact groups. The aim of this paper is to further
generalize the Fourier transform: Motivated by some recent works by Van Daele
in the multiplier Hopf algebra framework, and by using the Haar weights, we
define here the (generalized) Fourier transform and the inverse Fourier
transform, at the level of locally compact quantum groups. We will then
consider the analogues of the Fourier inversion theorem, Plancherel theorem,
and the convolution product. Along the way, we also obtain an alternative
description of the dual pairing map between a quantum group and its dual.


title:
Schwinger-Dyson operator of Yang-Mills matrix models with ghosts and
  derivations of the graded shuffle algebra

abstract:
  We consider large-N multi-matrix models whose action closely mimics that of
Yang-Mills theory, including gauge-fixing and ghost terms. We show that the
factorized Schwinger-Dyson loop equations, expressed in terms of the generating
series of gluon and ghost correlations G(xi), are quadratic equations S^i G = G
xi^i G in concatenation of correlations. The Schwinger-Dyson operator S^i is
built from the left annihilation operator, which does not satisfy the Leibnitz
rule with respect to concatenation. So the loop equations are not differential
equations. We show that left annihilation is a derivation of the graded shuffle
product of gluon and ghost correlations. The shuffle product is the point-wise
product of Wilson loops, expressed in terms of correlations. So in the limit
where concatenation is approximated by shuffle products, the loop equations
become differential equations. Remarkably, the Schwinger-Dyson operator as a
whole is also a derivation of the graded shuffle product. This allows us to
turn the loop equations into linear equations for the shuffle reciprocal, which
might serve as a starting point for an approximation scheme.


title: Voice Service Support in Mobile Ad Hoc Networks

abstract:
  Mobile ad hoc networks are expected to support voice traffic. The requirement
for small delay and jitter of voice traffic poses a significant challenge for
medium access control (MAC) in such networks. User mobility makes it more
complex due to the associated dynamic path attenuation. In this paper, a MAC
scheme for mobile ad hoc networks supporting voice traffic is proposed. With
the aid of a low-power probe prior to DATA transmissions, resource reservation
is achieved in a distributed manner, thus leading to small delay and jitter.
The proposed scheme can automatically adapt to dynamic path attenuation in a
mobile environment. Simulation results demonstrate the effectiveness of the
proposed scheme.


title:
Explicit chiral symmetry breaking and the 1/N expansion in models with
  multi-fermion interactions

abstract:
  Explicit chiral symmetry breaking is a natural feature of many QCD inspired
models with multi-quark interactions. To carry out the 1/N expansion of these
theories, one integrates over the quark fields. In the process of calculating
the one-loop fermion determinant which is not chiral invariant due to quark
masses, special care must be taken in order not to alter the original symmetry
breaking pattern of the Lagrangian. We show how to do this consistently.


title: Propagation of coherent waves in elastically scattering media

abstract:
  A general method for calculating statistical properties of speckle patterns
of coherent waves propagating in disordered media is developed. It allows one
to calculate speckle pattern correlations in space, as well as their
sensitivity to external parameters. This method, which is similar to the
Boltzmann-Langevin approach for the calculation of classical fluctuations,
applies for a wide range of systems: From cases where the ray propagation is
diffusive to the regime where the rays experience only small angle scattering.
The latter case comprises the regime of directed waves where rays propagate
ballistically in space while their directions diffuse. We demonstrate the
applicability of the method by calculating the correlation function of the wave
intensity and its sensitivity to the wave frequency and the angle of incidence
of the incoming wave.


title:
Single-Inclusive Hadron Production in Polarized pp Scattering at
  Next-to-Leading Logarithmic Accuracy

abstract:
  We study the resummation of large logarithmic perturbative corrections to the
partonic cross sections relevant for the process pp-> h X at high transverse
momentum of the hadron h, when the initial protons are longitudinally
polarized. We perform the resummation to next-to-leading logarithmic accuracy.
We present numerical results for center-of-mass energies of 19.4 GeV, relevant
for comparisons to data from the Fermilab E704 experiment, and 62.4 GeV, where
preliminary data from RHIC have recently become available. We find significant
enhancements of the spin-dependent cross sections, but a decrease of the
double-spin asymmetry for the process. This effect is less pronounced at the
higher energy.


title: Reliability of Coupled Oscillators I: Two-Oscillator Systems

abstract:
  This paper concerns the reliability of a pair of coupled oscillators in
response to fluctuating inputs. Reliability means that an input elicits
essentially identical responses upon repeated presentations regardless of the
network's initial condition. Our main result is that both reliable and
unreliable behaviors occur in this network for broad ranges of coupling
strengths, even though individual oscillators are always reliable when
uncoupled. A new finding is that at low input amplitudes, the system is highly
susceptible to unreliable responses when the feedforward and feedback couplings
are roughly comparable. A geometric explanation based on shear-induced chaos at
the onset of phase-locking is proposed.


title: Quantum communication. Non-classical correlations and their applications

abstract:
  In the first part of this thesis Bell's theorem is revisited. It points at a
difference between the quantum and the classical world. This difference is
often behind the advantages of solutions using quantum mechanics. New and more
general versions of Bell inequalities are presented. These inequalities involve
multiple settings per observer. Compared with the two-setting inequalities, the
new ones reveal the non-classical character of a broader class of states. Some
of them are also proven to be optimal (tight). Next, we go beyond Bell's
theorem. It is shown, both in theory and in experiment, that incompatibility
between quantum mechanics and realistic theories can be extended into an
important class of nonlocal models. We also show that the violation of Bell
inequalities disqualifies local realistic models with a limited lack of the
experimenter's freedom. This, at first glance quite philosophical result, has
its down-to-earth implications for quantum communication. In the second part of
the thesis well-known examples of quantum communication are reviewed. Next, new
results concerning quantum cryptography and quantum communication complexity
are given.


title: Reliability of Coupled Oscillators II: Larger Networks

abstract:
  We study the reliability of phase oscillator networks in response to
fluctuating inputs. Reliability means that an input elicits essentially
identical responses upon repeated presentations, regardless of the network's
initial condition. In this paper, we extend previous results on two-cell
networks to larger systems. The first issue that arises is chaos in the absence
of inputs, which we demonstrate and interpret in terms of reliability. We give
a mathematical analysis of networks that can be decomposed into modules
connected by an acyclic graph. For this class of networks, we show how to
localize the source of unreliability, and address questions concerning
downstream propagation of unreliability once it is produced.


title:
Synthesis and Analysis of Entangled Photonic Qubits in Spatial-Parity
  Space

abstract:
  We present the novel embodiment of a photonic qubit that makes use of one
continuous spatial degree of freedom of a single photon and relies on the the
parity of the photon's transverse spatial distribution. Using optical
spontaneous parametric downconversion to produce photon pairs, we demonstrate
the controlled generation of entangled-photon states in this new space.
Specifically, two Bell states, and a continuum of their superpositions, are
generated by simple manipulation of a classical parameter, the optical-pump
spatial parity, and not by manipulation of the entangled photons themselves. An
interferometric device, isomorphic in action to a polarizing beam splitter,
projects the spatial-parity states onto an even--odd basis. This new physical
realization of photonic qubits could be used as a foundation for future
experiments in quantum information processing.


title:
Notes on noncommutative supersymmetric gauge theory on the fuzzy
  supersphere

abstract:
  In these notes we review Klimcik's construction of noncommutative gauge
theory on the fuzzy supersphere. This theory has an exact SUSY gauge symmetry
with a finite number of degrees of freedom and thus in principle it is amenable
to the methods of matrix models and Monte Carlo numerical simulations. We also
write down in this article a novel fuzzy supersymmetric scalar action on the
fuzzy supersphere.


title:
A Proposal for a Non-Perturbative Regularization of {\cal N}=2 SUSY 4D
  Gauge Theory

abstract:
  In this letter we show that supersymmetry like geometry can be approximated
using finite dimensional matrix models and fuzzy manifolds. In particular we
propose a non-perturbative regularization of {\cal N}=2 supersymmetric U(n)
gauge action in 4D. In some planar large N limits we recover exact SUSY
together with the smooth geometry of R^4_{theta}.


title:
On the regularity of weak solutions of the 3D Navier-Stokes equations in
  $B^{-1}_{\infty,\infty}$

abstract:
  We show that if a Leray-Hopf solution $u$ to the 3D Navier-Stokes equation
belongs to $C((0,T]; B^{-1}_{\infty,\infty})$ or its jumps in the
$B^{-1}_{\infty,\infty}$-norm do not exceed a constant multiple of viscosity,
then $u$ is regular on $(0,T]$. Our method uses frequency local estimates on
the nonlinear term, and yields an extension of the classical
Ladyzhenskaya-Prodi-Serrin criterion.


title: On the structure of Thom polynomials of singularities

abstract:
  Thom polynomials of singularities express the cohomology classes dual to
singularity submanifolds. A stabilization property of Thom polynomials is known
classically, namely that trivial unfolding does not change the Thom polynomial.
In this paper we show that this is a special case of a product rule. The
product rule enables us to calculate the Thom polynomials of singularities if
we know the Thom polynomial of the product singularity. As a special case of
the product rule we define a formal power series (Thom series, Ts_Q) associated
with a commutative, complex, finite dimensional local algebra Q, such that the
Thom polynomial of {\em every} singularity with local algebra Q can be
recovered from Ts_Q.


title: Regge behavior of gluon scattering amplitudes in N=4 SYM theory

abstract:
  It is shown that the four-gluon scattering amplitude for N=4 supersymmetric
Yang-Mills theory in the planar limit can be written, in both the weak- and
strong-coupling limits, as a reggeized amplitude, with a parent trajectory and
an infinite number of daughter trajectories. This result relies crucially on
the fact that the leading IR-divergence and the finite log^2(s/t)-dependent
piece of the amplitude are characterized by the same function for all values of
the coupling, as conjectured by Bern, Dixon, and Smirnov, and proved by Alday
and Maldacena in the strong-coupling limit. We use the Alday-Maldacena result
to determine the strong-coupling Regge trajectory.


title:
Network Coding Capacity of Random Wireless Networks under a
  Signal-to-Interference-and-Noise Model

abstract:
  In this paper, we study network coding capacity for random wireless networks.
Previous work on network coding capacity for wired and wireless networks have
focused on the case where the capacities of links in the network are
independent. In this paper, we consider a more realistic model, where wireless
networks are modeled by random geometric graphs with interference and noise. In
this model, the capacities of links are not independent. We consider two
scenarios, single source multiple destinations and multiple sources multiple
destinations. In the first scenario, employing coupling and martingale methods,
we show that the network coding capacity for random wireless networks still
exhibits a concentration behavior around the mean value of the minimum cut
under some mild conditions. Furthermore, we establish upper and lower bounds on
the network coding capacity for dependent and independent nodes. In the second
one, we also show that the network coding capacity still follows a
concentration behavior. Our simulation results confirm our theoretical
predictions.


title:
The double-slit and the EPR experiments: A paradox-free kinematic
  description

abstract:
  The paradoxes of the double-slit and the EPR experiments with particles are
shown to originate in the implicit assumption that the particles are always
located in the classical space. It is demonstrated that there exists a natural
substitute for this assumption that provides a method of resolving the
paradoxes.


title: On higher real and stable ranks for CCR C*-algebras

abstract:
  We calculate the real rank and stable rank of CCR algebras which either have
only finite dimensional irreducible representations or have finite topological
dimension. We show that either rank of A is determined in a good way by the
ranks of an ideal I and the quotient A/I in four cases: When A is CCR; when I
has only finite dimensional irreducible representations; when I is separable,
of generalized continuous trace and finite topological dimension, and all
irreducible representations of I are infinite dimensional; or when I is
separable, stable, has an approximate identity consisting of projections, and
has the corona factorization property. We also present a counterexample on
higher ranks of M(A), A subhomogeneous, and a theorem of P. Green on
generalized continuous trace algebras.


title: Spontaneous Resonances and the Coherent States of the Queuing Networks

abstract:
  We present an example of a highly connected closed network of servers, where
the time correlations do not go to zero in the infinite volume limit. This
phenomenon is similar to the continuous symmetry breaking at low temperatures
in statistical mechanics. The role of the inverse temperature is played by the
average load.


title: Phase-slip induced dissipation in an atomic Bose-Hubbard system

abstract:
  Phase slips play a primary role in dissipation across a wide spectrum of
bosonic systems, from determining the critical velocity of superfluid helium to
generating resistance in thin superconducting wires. This subject has also
inspired much technological interest, largely motivated by applications
involving nanoscale superconducting circuit elements, e.g., standards based on
quantum phase-slip junctions. While phase slips caused by thermal fluctuations
at high temperatures are well understood, controversy remains over the role of
phase slips in small-scale superconductors. In solids, problems such as
uncontrolled noise sources and disorder complicate the study and application of
phase slips. Here we show that phase slips can lead to dissipation for a clean
and well-characterized Bose-Hubbard (BH) system by experimentally studying
transport using ultra-cold atoms trapped in an optical lattice. In contrast to
previous work, we explore a low velocity regime described by the 3D BH model
which is not affected by instabilities, and we measure the effect of
temperature on the dissipation strength. We show that the damping rate of
atomic motion-the analogue of electrical resistance in a solid-in the confining
parabolic potential fits well to a model that includes finite damping at zero
temperature. The low-temperature behaviour is consistent with the theory of
quantum tunnelling of phase slips, while at higher temperatures a cross-over
consistent with the transition to thermal activation of phase slips is evident.
Motion-induced features reminiscent of vortices and vortex rings associated
with phase slips are also observed in time-of-flight imaging.