title: Galerkin Methods for the Fully Nonlinear Monge-Amp\`ere Equation

abstract:
  This paper develops and analyzes finite element Galerkin and spectral
Galerkin methods for approximating viscosity solutions of the fully nonlinear
Monge-Amp\`ere equation $\det(D^2u^0)=f$ based on the vanishing moment method
which was developed by the authors in \cite{Feng2,Feng1}. In this approach, the
Monge-Amp\`ere equation is approximated by the fourth order quasilinear
equation $-\epsilon\Delta^2 u^\epsilon + \det{D^2u^\epsilon} =f$ accompanied by
appropriate boundary conditions. This new approach allows one to construct
convergent Galerkin numerical methods for the fully nonlinear Monge-Amp\`ere
equation, a task which has been impracticable before. In this paper, we first
develop some finite element and spectral Galerkin methods for approximating the
solution $u^\epsilon$ of the regularized fourth order problem. We then derive
optimal order error estimates for the proposed numerical methods. In
particular, we track explicitly the dependence of the error bounds on the
parameter $\vepsi$, for the error $u^\epsilon-u^\epsilon_h$. Finally, using the
Aygris finite element method as an example, we present a detailed numerical
study of the rates of convergence in terms of powers of $\vepsi$ for the error
$u^0-u_h^\vepsi$, and numerically examine what is the "best" mesh size $h$ in
relation to $\vepsi$ in order to achieve these rates.


title:
Mixed finite element methods for the fully nonlinear Monge-Amp\`ere
  equation based on the vanishing moment method

abstract:
  This paper studies mixed finite element approximations of the viscosity
solution to the Dirichlet problem for the fully nonlinear Monge-Amp\`ere
equation $\det(D^2u^0)=f$ based on the vanishing moment method which was
proposed recently by the authors in \cite{Feng2}. In this approach, the second
order fully nonlinear Monge-Amp\`ere equation is approximated by the fourth
order quasilinear equation $-\epsilon\Delta^2 u^\epsilon + \det{D^2u^\epsilon}
=f$. It was proved in \cite{Feng1} that the solution $u^\epsilon$ converges to
the unique convex viscosity solution $u^0$ of the Dirichlet problem for the
Monge-Amp\`ere equation. This result then opens a door for constructing
convergent finite element methods for the fully nonlinear second order
equations, a task which has been impracticable before. The goal of this paper
is threefold. First, we develop a family of Hermann-Miyoshi type mixed finite
element methods for approximating the solution $u^\epsilon$ of the regularized
fourth order problem, which computes simultaneously $u^\vepsi$ and the moment
tensor $\sigma^\vepsi:=D^2u^\epsilon$. Second, we derive error estimates, which
track explicitly the dependence of the error constants on the parameter
$\vepsi$, for the errors $u^\epsilon-u^\epsilon_h$ and
$\sigma^\vepsi-\sigma_h^\vepsi$. Finally, we present a detailed numerical study
on the rates of convergence in terms of powers of $\vepsi$ for the error
$u^0-u_h^\vepsi$ and $\sigma^\vepsi-\sigma_h^\vepsi$, and numerically examine
what is the "best" mesh size $h$ in relation to $\vepsi$ in order to achieve
these rates.


title:
High multipole transitions in NIXS: valence and hybridization in 4f
  systems

abstract:
  Momentum-transfer (q) dependent non-resonant inelastic x-ray scattering
measurements were made at the N4,5 edges for several rare earth compounds. With
increasing q, giant dipole resonances diminish, to be replaced by strong
multiplet lines at lower energy transfer. These multiplets result from two
different orders of multipole scattering and are distinct for systems with
simple 4f^0 and 4f^1 initial states. A many-body theoretical treatment of the
multiplets agrees well with the experimental data on ionic La and Ce phosphate
reference compounds. Comparing measurements on CeO2 and CeRh3 to the theory and
the phosphates indicates sensitivity to hybridization as observed by a
broadening of 4f^0-related multiplet features. We expect such strong, nondipole
features to be generic for NIXS from f-electron systems.


title: What are the Luminous Compact Blue Galaxies?

abstract:
  Luminous Compact Blue Galaxies (LCBGs) are common at z~1, contributing
significantly to the total star formation rate density. By z~0, they are a
factor of ten rarer. While we know that LCBGs evolve rapidly, we do not know
what drives their evolution nor into what types of galaxies they evolve. We
present the results of a single-dish HI survey of local LCBGs undertaken to
address these questions. Our results indicate that LCBGs have M(HI) and M(DYN)
consistent with low-mass spirals, but typically exhaust their gas reservoirs in
less than 2 Gyr. Overall, the properties of LCBGs are consistent with them
evolving into high-mass dwarf elliptical or dwarf irregular galaxies or
low-mass, late-type spiral galaxies.


title: Projectively full ideals in Noetherian rings, a survey

abstract:
  We discuss projective equivalence of ideals in Noetherian rings and the
existence or failure of existence of projectively full ideals. We describe
connections with the Rees valuations and Rees integers of an ideal, and
consider the question of whether improvements can be made by passing to an
integral extension ring.


title:
Massive Star Formation Near Sgr A* and Bimodal Star Formation in the
  Nuclear Disk

abstract:
  The history of star formation in the strong gravitational potential of the
Galactic center has been of much interest, recently. We propose that the
sub-parsec-scale disk of massive stars orbiting the massive black hole at the
Galactic center can be interpreted in terms of partial accretion of extended
Galactic center clouds, such as the 50 \kms molecular cloud, as these clouds
envelop Sgr A* on their passage through the inner Galactic center. The loss of
angular momentum of the captured cloud material by self-interaction subsequent
to gravitationally focusing by Sgr A* naturally creates a compact gaseous disk
of material close to Sgr A* in which star formation takes place. On a larger
scale the formation of massive clusters such as the Arches and Quintuplet
clusters or on-going massive star formation such as Sgr B2 could also be
triggered by cloud-cloud collisions due to gravitational focusing in the deep
potential of the central bulge.
  Unlike the violent and high-pressure environment of clustered star formation
triggered by cloud-cloud collision, there are also isolated pockets of star
formation and quiescent dense clouds. These sites suggest an inefficient, slow
mode of star formation. We propose enhanced cosmic rays in the nuclear disk may
be responsible for inhibiting the process of star formation in this region. In
particular, we argue that the enhanced ionization rate due to the impact of
cosmic-ray particles is responsible for lowering the efficiency of on-going
star formation in the nuclear disk of our Galaxy. The higher ionization
fraction and higher thermal energy due to the impact of these electrons may
also reduce MHD wave damping which contributes to the persistence of the high
velocity dispersion of the molecular gas in the nuclear disk.


title: Orbit closures of directing modules are regular in codimension one

abstract:
  We show that the orbit closure of a directing module is regular in
codimension one. In particular, this result gives information about a
distinguished irreducible component of a module variety.


title: Pyrometric Measurement of the Temperature of Shocked Molybdenum

abstract:
  Measurements of the temperature of Mo shocked to ~60 GPa and then released to
~28 GPa were previously attempted using high explosive driven flyer plates and
pyrometry. Analysis of the radiance traces at different wavelengths indicates
that the temporal evolution of the radiance can be explained by a contribution
from the LiF window to the measured thermal radiation. Fitting the radiance
traces with a simple model, supported by continuum dynamics studies which were
able to relate structures in the radiance history to hydrodynamic events in the
experiment, the contribution of the window was obtained and hence the
temperature of the Mo sample. The shock-and release temperature obtained in the
Mo was 762+/-40K which is consistent with calculations taking the contribution
of plastic work to the heating into account. The radiance obtained for the LiF
window shows a non thermal distribution which can be described by a bulk
temperature of 624+/-112K and hot spots (less than 0.5% in total volume) within
the window at a temperature of about 2000K.


title:
Determination of Trion and Exciton Lineshapes in Modulation-Doped
  Quantum Wells

abstract:
  We investigate the effect of a two dimensional electron gas on the linear
optical properties of CdTe quantum wells. We evidence experimentally the high
energy tail of the exciton and charged exciton resonances which depends on
electron concentration. Based on that, we show that the scattering of electrons
with excitons and charged excitons is needed to be included in the matrix
transfer calculations to describe the reflectivity spectra. We demonstrate by
time-resolved reflectivity experiments the importance of electron distribution
in the resonance lineshapes.


title:
Symbolic Rees algebras, vertex covers and irreducible representations of
  Rees cones

abstract:
  Let G be a simple graph and let J be its ideal of vertex covers. We give a
graph theoretical description of the irreducible b-vertex covers of G, i.e., we
describe the minimal generators of the symbolic Rees algebra of J. Then we
study the irreducible b-vertex covers of the blocker of G, i.e., we study the
minimal generators of the symbolic Rees algebra of the edge ideal of G. We give
a graph theoretical description of the irreducible binary b-vertex covers of
the blocker of G. It is shown that they correspond to irreducible induced
subgraphs of G. As a byproduct we obtain a method, using Hilbert bases, to
obtain all irreducible induced subgraphs of G. In particular we obtain all odd
holes and antiholes. We study irreducible graphs and give a method to construct
irreducible b-vertex covers of the blocker of G with high degree relative to
the number of vertices of G.


title: Gravitational Wave Detection with Atom Interferometry

abstract:
  We propose two distinct atom interferometer gravitational wave detectors, one
terrestrial and another satellite-based, utilizing the core technology of the
Stanford $10 \text{m}$ atom interferometer presently under construction. The
terrestrial experiment can operate with strain sensitivity $ \sim
\frac{10^{-19}}{\sqrt{\text{Hz}}}$ in the 1 Hz - 10 Hz band, inaccessible to
LIGO, and can detect gravitational waves from solar mass binaries out to
megaparsec distances. The satellite experiment probes the same frequency
spectrum as LISA with better strain sensitivity $ \sim
\frac{10^{-20}}{\sqrt{\text{Hz}}}$. Each configuration compares two widely
separated atom interferometers run using common lasers. The effect of the
gravitational waves on the propagating laser field produces the main effect in
this configuration and enables a large enhancement in the gravitational wave
signal while significantly suppressing many backgrounds. The use of ballistic
atoms (instead of mirrors) as inertial test masses improves systematics coming
from vibrations and acceleration noise, and reduces spacecraft control
requirements.

categories: gr-qc astro-ph hep-ph hep-th physics.atom-ph


title:
Quantum Phase Transition between (Luttinger) Liquid and Gas of Cold
  Molecules

abstract:
  We consider cold polar molecules confined in a helical optical lattice
similar to those used in holographic microfabrication. An external electric
field polarizes molecules along the axis of the helix. The large-distance
inter-molecular dipolar interaction is attractive but the short-scale
interaction is repulsive due to geometric constraints and thus prevents
collapse. The interaction strength depends on the electric field. We show that
a zero-temperature second-order liquid-gas transition occurs at a critical
field. It can be observed under experimentally accessible conditions.


title: The D^6 R^4 term in type IIB string theory on T^2 and U-duality

abstract:
  We propose a manifestly U-duality invariant modular form for the D^6 R^4
interaction in the effective action of type IIB string theory compactified on
T^2. It receives perturbative contributions upto genus three, as well as
non-perturbative contributions from D-instantons and (p,q) string instantons
wrapping T^2. Our construction is based on constraints coming from string
perturbation theory, U-duality, the decompactification limit to ten dimensions,
and the equality of the perturbative part of the amplitude in type IIA and type
IIB string theories. Using duality, parts of the perturbative amplitude are
also shown to match exactly the results obtained from eleven dimensional
supergravity compactified on T^3 at one loop. We also obtain parts of the genus
one and genus k amplitudes for the D^{2k} R^4 interaction for arbitrary k > 3.
We enhance a part of this amplitude to a U-duality invariant modular form.


title:
Understanding the Protected Nodes and Collapse of the Fermi Arcs in
  Underdoped Cuprate Superconductors

abstract:
  We show how recent angle resolved photoemission measurements addressing the
Fermi arcs in the cuprates reveal a very natural phenomenological description
of the complex superfluid phase. Importantly, this phenomenology is consistent
with a previously presented microscopic theory. By distinguishing the order
parameter and the excitation gap, we are able to demonstrate how the collapse
of the arcs below $T_c$ into well defined nodes is associated with the
\emph{smooth} emergence of superconducting coherence. Comparison of this theory
with experiment shows good semi-quantitative agreement.


title: Large Radius Hagedorn Regime in String Gas Cosmology

abstract:
  We calculate the equation of state of a gas of strings at high density in a
large toroidal universe, and use it to determine the cosmological evolution of
background metric and dilaton fields in the entire large radius Hagedorn
regime, (ln S)^{1/d} << R << S^{1/d} (with S the total entropy). The pressure
in this regime is not vanishing but of O(1), while the equation of state is
proportional to volume, which makes our solutions significantly different from
previously published approximate solutions. For example, we are able to
calculate the duration of the high-density "Hagedorn" phase, which increases
exponentially with increasing entropy, S. We go on to discuss the difficulties
of the scenario, quantifying the problems of establishing thermal equilibrium
and producing a large but not too weakly-coupled universe.


title:
Stochastic actions for diffusive dynamics: Reweighting, sampling, and
  minimization

abstract:
  In numerical studies of diffusive dynamics, two different action functionals
are often used to specify the probability distribution of trajectories, one of
which requiring the evaluation of the second derivative of the potential in
addition to the force. Here it is argued that both actions are equivalent
prescriptions for the purposes of reweighting and sampling trajectories,
whereas the most probable path is more generally given by the global minimum of
the action involving the second derivative term. The answer to this apparent
paradox lies in the non-differentiable character of Brownian paths, as well as
in the "entropy" associated with a given trajectory.


title:
Teleparallel Energy-Momentum Distribution of Spatially Homogeneous
  Rotating Spacetimes

abstract:
  The energy-momentum distribution of spatially homogeneous rotating spacetimes
in the context of teleparallel theory of gravity is investigated. For this
purpose, we use the teleparallel version of Moller prescription. It is found
that the components of energy-momentum density are finite and well-defined but
are different from General Relativity. However, the energy-momentum density
components become the same in both theories under certain assumptions. We also
analyse these quantities for some special solutions of the spatially
homogeneous rotating spacetimes.


title:
Quasi-energies and Floquet states of two weakly coupled Bose-Einstein
  condensates under periodic driving

abstract:
  We investigate the quasi-energies and Floquet states of two weakly coupled
Bose-Einstein condensates driven by a periodic force. The quasi-energies and
Floquet states of this system are computed within two different theoretical
frameworks: the mean-field model and the second-quantized model. The mean-field
approach reveals a triangular structure in the quasi-energy band. Our analysis
of the corresponding Floquet states shows that this triangle signals the onset
of a localization phenomenon, which can be regarded as a generalization of the
well-known phenomenon called coherent destruction of tunneling. With the second
quantized model, we find also a triangular structure in the quantum
quasi-energy band, which is enveloped by the mean-field triangle. The close
relation between these two sets of quasi-energies is further explored by a
semi-classical method. With a Sommerfeld rule generalized to time-dependent
systems, the quantum quasi-energies are computed by quantizing semiclassically
the mean-field model and they are found to agree very well with the results
obtained directly with the second-quantized model.


title:
Numerical performance of the parabolized ADM (PADM) formulation of
  General Relativity

abstract:
  In a recent paper the first coauthor presented a new parabolic extension
(PADM) of the standard 3+1 Arnowitt, Deser, Misner formulation of the equations
of general relativity. By parabolizing first-order ADM in a certain way, the
PADM formulation turns it into a mixed hyperbolic - second-order parabolic,
well-posed system. The surface of constraints of PADM becomes a local attractor
for all solutions and all possible well-posed gauge conditions. This paper
describes a numerical implementation of PADM and studies its accuracy and
stability in a series of standard numerical tests. Numerical properties of PADM
are compared with those of standard ADM and its hyperbolic Kidder, Scheel,
Teukolsky (KST) extension. The PADM scheme is numerically stable, convergent
and second-order accurate. The new formulation has better control of the
constraint-violating modes than ADM and KST.


title: Hierarchical, Regular Small-World Networks

abstract:
  Two new classes of networks are introduced that resemble small-world
properties. These networks are recursively constructed but retain a fixed,
regular degree. They consist of a one-dimensional lattice backbone overlayed by
a hierarchical sequence of long-distance links. Both types of networks, one
3-regular and the other 4-regular, lead to distinct behaviors, as revealed by
renormalization group studies. The 3-regular networks are planar, have a
diameter growing as \sqrt{N} with the system size N, and lead to
super-diffusion with an exact, anomalous exponent d_w=1.3057581..., but
possesses only a trivial fixed point T_c=0 for the Ising ferromagnet. In turn,
the 4-regular networks are non-planar, have a diameter growing as
~2^[\sqrt(\log_2 N^2)], exhibit "ballistic" diffusion (d_w=1), and a
non-trivial ferromagnetic transition, T_c>0. It suggest that the 3-regular
networks are still quite "geometric", while the 4-regular networks qualify as
true small-world networks with mean-field properties. As an example of an
application we discuss synchronization of processors on these networks.


title: Large Volume Axionic Swiss-Cheese Inflation

abstract:
  Continuing with the ideas of (section 4 of) [1], after inclusion of
perturbative and non-perturbative alpha' corrections to the Kaehler potential
and (D1- and D3-) instanton generated superpotential, we show the possibility
of slow-roll axionic inflation in the large volume limit of Swiss-Cheese
Calabi-Yau orientifold compactifications of type IIB string theory. We also
include one- and two-loop corrections to the Kaehler potential but find the
same to be subdominant to the (perturbative and non-perturbative) alpha'
corrections. The NS-NS axions provide a flat direction for slow-roll inflation
to proceed from a saddle point to the nearest dS minimum.


title: Masses of Nix and Hydra

abstract:
  A four-body orbit solution for the Pluto system yields GM values of 870.3 +/-
3.7, 101.4 +/- 2.8, 0.039 +/- 0.034, and 0.021 +/- 0.042 km3 sec-2 for Pluto,
Charon, Nix, and Hydra, respectively. Assuming a Charon-like density of 1.63 gm
cm-3, the implied diameters for Nix and Hydra are 88 and 72 km, leading to
visual geometric albedos of 0.08 and 0.18, respectively, though with
considerable uncertainty. The eccentricity of Charon's orbit has a significant
nonzero value; however, the 0.030 +/- 0.009 deg yr-1 rate at which the line of
apsides precesses is insufficient to explain the difference in the longitude of
periapsis seen in the orbits fitted to the 1992-1993 and 2002-2003 data sets.
The mean orbital periods for Hydra, Nix, and Charon are in the ratios of 6.064
+/- 0.006 : 3.991 +/- 0.007 : 1, but we have not identified any resonant
arguments that would indicate the existence of a mean motion resonance between
any pairs of satellites.


title: Magnetic Moment Collapse-Driven Mott Transition in MnO

abstract:
  The metal-insulator transition in correlated electron systems, where electron
states transform from itinerant to localized, has been one of the central
themes of condensed matter physics for more than half a century. The
persistence of this question has been a consequence both of the intricacy of
the fundamental issues and the growing recognition of the complexities that
arise in real materials, even when strong repulsive interactions play the
primary role. The initial concept of Mott was based on the relative importance
of kinetic hopping (measured by the bandwidth) and on-site repulsion of
electrons. Real materials, however, have many additional degrees of freedom
that, as is recently attracting note, give rise to a rich variety of scenarios
for a ``Mott transition.'' Here we report results for the classic correlated
insulator MnO which reproduce a simultaneous moment collapse, volume collapse,
and metallization transition near the observed pressure, and identify the
mechanism as collapse of the magnetic moment due to increase of crystal field
splitting, rather than to variation in the bandwidth.


title: Crustal Oscillations of Slowly Rotating Relativistic Stars

abstract:
  We study low-amplitude crustal oscillations of slowly rotating relativistic
stars consisting of a central fluid core and an outer thin solid crust. We
estimate the effect of rotation on the torsional toroidal modes and on the
interfacial and shear spheroidal modes. The results compared against the
Newtonian ones for wide range of neutron star models and equations of state.


title: Theoretical construction of 1D anyon models

abstract:
  One-dimensional anyon models are renewedly constructed by using path integral
formalism. A statistical interaction term is introduced to realize the anyonic
exchange statistics. The quantum mechanics formulation of statistical
transmutation is presented.


title:
The trapped two-dimensional Bose gas: from Bose-Einstein condensation to
  Berezinskii-Kosterlitz-Thouless physics

abstract:
  We analyze the results of a recent experiment with bosonic rubidium atoms
harmonically confined in a quasi-two-dimensional geometry. In this experiment a
well defined critical point was identified, which separates the
high-temperature normal state characterized by a single component density
distribution, and the low-temperature state characterized by a bimodal density
distribution and the emergence of high-contrast interference between
independent two-dimensional clouds. We first show that this transition cannot
be explained in terms of conventional Bose-Einstein condensation of the trapped
ideal Bose gas. Using the local density approximation, we then combine the
mean-field (MF) Hartree-Fock theory with the prediction for the
Berezinskii-Kosterlitz-Thouless transition in an infinite uniform system. If
the gas is treated as a strictly 2D system, the MF predictions for the spatial
density profiles significantly deviate from those of a recent Quantum
Monte-Carlo (QMC) analysis. However when the residual thermal excitation of the
strongly confined degree of freedom is taken into account, an excellent
agreement is reached between the MF and the QMC approaches. For the interaction
strength corresponding to the experiment, we predict a strong correction to the
critical atom number with respect to the ideal gas theory (factor $\sim 2$). A
quantitative agreement between theory and experiment is reached concerning the
critical atom number if the predicted density profiles are used for temperature
calibration.


title:
Majoration du nombre de z\'eros d'une fonction m\'eromorphe en dehors
  d'une droite verticale et applications

abstract:
  We study the distribution of the zeros of functions of the form $f(s)=h(s)
\pm h(2a-s)$, where $h(s)$ is a meromorphic function, real on the real line,
$a$ a real number. One of our results establishes sufficient conditions under
which all but finitely many of the zeros of $f(s)$ lie on the line $\Re s = a$,
called the {\it critical line} for the function $f(s)$, and be simple, given
that all but finitely many of the zeros of $h(s)$ lie on the half-plane $\Re s
< a$. This results can be regarded as a generalization of the necessary
condition of stability for the function $h(s)$, in the Hermite-Biehler theorem.
We apply this results to the study of translations of the Riemann Zeta Function
and $L$ functions, and integrals of Eisenstein Series, among others.


title: Plasma induced neutrino spin flip via the neutrino magnetic moment

abstract:
  The neutrino spin flip radiative conversion processes nu_L -> nu_R + gamma^*
and nu_L + gamma^* -> nu_R in medium are considered. It is shown in part that
an analysis of the so-called spin light of neutrino without a complete taking
account of both the neutrino and the photon dispersion in medium is physically
inconsistent.


title:
Induced magnetism by single carbon vacancies in a three-dimensional
  graphitic network: a supercell study

abstract:
  We present an ab initio DFT study of the magnetic moments that arise in
graphite by creating single carbon vacancies in a 3-D graphite network, using a
full potential, all electron, spin polarized electronic structure calculations.
In previous reports the appearance of magnetic moments was explained in a 2-D
graphene sheet just through the existence of the vacancies itself [1-5]. The
dependence of the arising magnetic moment on the nature and geometry of the
vacancies for different supercells is reported. We found that the highest value
of magnetic moment is obtained for a 3x3x1 supercell and that the highly
diluted 5x5x1 supercell shows no magnetic ordering. The results obtained in
this manuscript are indicative of the importance of interlayer interactions
present in a 3-D stacking. We conclude that this should not be underestimated
when vacancies-based studies on magnetism in graphitic systems are carried out.


title:
On the facial structure of Symmetric and Graphical Traveling Salesman
  Polyhedra

abstract:
  The Symmetric Traveling Salesman Polytope $S_n$ for a fixed number $n$ of
cities is a face of the corresponding Graphical Traveling Salesman Polyhedron
$P_n$. This has been used to study facets of $S_n$ using $P_n$ as a tool. In
this paper, we study the operation of "rotating" (or "lifting") valid
inequalities for $S_n$ to obtain a valid inequalities for $P_n$.
  As an application, we describe a surprising relationship between (a) the
parsimonious property of relaxations of the Symmetric Traveling Salesman
Polytope and (b) a connectivity property of the ridge graph of the Graphical
Traveling Salesman Polyhedron.


title: Coulomb Blockade in Graphene Nanodisks

abstract:
  Graphene nanodisk is a graphene derivative with a closed edge. The trigonal
zigzag nanodisk with size $N$ has $N$-fold degenerated zero-energy states. We
investigate electron-electron interaction effects in the zero-energy sector. We
explicitely derive the direct and exchange interactions, which are found to
have no SU($N$) symmetry. Then, regarding a nanodisk as a quantum dot with an
internal degree of freedom, we analyze the nanodisk-lead system consisting of a
nanodisk and two leads. Employing the standard Green function method, we reveal
novel Coulomb blockade effects in the system. The occupation number in the
nanodisk exhibits a peculiar series of plateaux and dips, reflecting a peculiar
structure of energy spectrum of nanodisk without SU($N$) symmetry. Dips are
argued to emerge due to a Coulomb correlation effect.


title: Fundamentals for Symplectic $\mathcal{A}$-modules

abstract:
  Sheaf theoretically based Abstract Differential Geometry incorporates and
generalizes all the classical differential geometry. Here, we undertake to
partially explore the implications of Abstract Differential Geometry to
classical symplectic geometry. The full investigation will be presented
elsewhere.


title: Navigation between quantum states by quantum mirrors

abstract:
  We introduce a technique that allows one to connect any two arbitrary (pure
or mixed) superposition states of an N-state quantum system. The proposed
solution to this inverse quantum mechanical problem is analytical, exact, and
very compact. The technique uses standard and generalized quantum Householder
reflections (QHRs), which require external pulses of precise areas and
frequencies. We show that any two pure states can be linked by just a single
generalized QHR. The transfer between any two mixed states with the same
dynamic invariants (e.g., the same density matrix eigenvalues) requires in
general N QHRs. Moreover, we propose recipes for synthesis of arbitrary
preselected mixed states using a combination of QHRs and incoherent processes
(pure dephasing or spontaneous emission).


title:
Jupiter, Saturn and the Pioneer anomaly: a planetary-based independent
  test

abstract:
  In this paper we use the ratio of the corrections to the standard
Newtonian/Einsteinian secular precessions of the longitudes of perihelia of
Jupiter and Saturn, recently estimated by the Russian astronomer E.V. Pitjeva
by fitting almost one century of data with the EPM ephemerides, to make an
independent, planetary-based test of the hypothesis that the Pioneer anomaly
(PA), as it is presently known in the 5-10 AU region, is of gravitational
origin. Accounting for the errors in the determined apsidal extra-rates and in
the values of the PA acceleration at the orbits of Jupiter and Saturn the
answer is negative. If and when the re-analysis of the entire Pioneer 10/11
will be completed more firm conclusions could be reached. Moreover, it would
also be important that other teams of astronomers estimate independently their
own corrections to the perihelion precessions.


title: INTEGRAL observation of the accreting pulsar 1E1145.1-6141

abstract:
  We analyze 1050 ks of INTEGRAL data of the high mass X-ray binary pulsar 1E
1145.1-6141 to study its properties over a long time baseline, from June 2003
to June 2004, with wide spectral coverage.
  We study three high luminosity episodes, two of them at the system apoastron,
three brightening with lower intensity, two at the periastron, and one extended
period of intermediate luminosity spanning one orbital cycle. We perform timing
analysis to determine the pulse period and pulse profiles at different energy
ranges. We also analyze the broad band phase average spectrum of different
luminosity states and perform phase resolved spectroscopy for the first flare.
  From the timing analysis, we find a pulse period of ~297 s around MJD 53000
with a significant scatter around the mean value. From the spectral analysis we
find that the source emission can be described by an absorbed bremsstrahlung
model in which the electron temperature varies between ~25 and ~37 keV, without
any correlation to luminosity, and the intrinsic absorbing column is constantly
of the order of 10^23 cm^-2. Phase resolved spectral analysis evidences a
different temperature of the plasma in the ascending and descending edges of
the pulse during the first flare. This justifies the pulse maximum shift by
~0.4 phase units between 20 and 100 keV observed in the pulse profiles.
  The comparison with the previous period measurements reveals that the source
is currently spinning-down, in contrast to the long term secular trend observed
so far indicating that at least a temporary accretion disk is formed. The study
of the spectral property variations with respect to time and spin phase
suggests the presence of two emitting components at different temperatures
whose relative intensity varies with time.


title: Continuous-time trading and emergence of randomness

abstract:
  A new definition of events of game-theoretic probability zero in continuous
time is proposed and used to prove results suggesting that trading in financial
markets results in the emergence of properties usually associated with
randomness. This paper concentrates on "qualitative" results, stated in terms
of order (or order topology) rather than in terms of the precise values taken
by the price processes (assumed continuous).


title:
Superconductivity in the Three-Fold Charge-Ordered Metal of the
  Triangular-Lattice Extended Hubbard Model

abstract:
  The quarter-filling extended Hubbard model on the triangular lattice is
studied to explore pairing instability in the three-fold charge-ordered (CO)
metal. We derive a second-order strong-coupling effective Hamiltonian of doped
carriers into the three-fold CO insulator at electron density of $n=2/3$, and
then study the $f$- and $d_{xy}$-wave superconductivities down to $n=1/2$ by
using the BCS mean-field approximation. It is found that the triplet $f$-wave
pairing is more stable than the $d_{xy}$-wave one. We also point out that this
coexisting state of the charge ordering and superconductivity is possible to
have critical temperature $T_c \sim 0.01 t$.


title: Spin-resolved crossed Andreev reflection in ballistic heterostructures

abstract:
  We theoretically analyze non-local effects in electron transport across
three-terminal ballistic normal-superconducting-normal (NSN) structures with
spin-active interfaces. Subgap electrons entering S-electrode from one N-metal
may form Cooper pairs with their counterparts penetrating from another N-metal.
This phenomenon of crossed Andreev reflection is highly sensitive to electron
spins and yields a rich variety of properties of non-local conductance which we
describe non-perturbatively at arbitrary interface transmissions, voltages and
temperatures. Our results can be applied to hybrid structures with normal,
ferromagnetic and half-metallic electrodes and can be directly tested in future
experiments.


title: Analytical models for quark stars

abstract:
  We find two new classes of exact solutions to the Einstein-Maxwell system of
equations. The matter content satisfies a linear equation of state consistent
with quark matter; a particular form of one of the gravitational potentials is
specified to generate solutions. The exact solutions can be written in terms of
elementary functions, and these can be related to quark matter in the presence
of an electromagnetic field. The first class of solutions generalises the Mak
and Harko model. The second class of solutions does not admit any singularities
in the matter and gravitational potentials at the centre.


title: Kleene, Rogers and Rice Theorems Revisited in C and in Bash

abstract:
  The recursion theorem in the weak form {e}(z)=x(e,z) (universal function not
needed) and in Rogers form {n}(z)={{x}(n)}(z) and Rice theorem are proved a
first time using programs in C, and a second time with scripts in Bash.


title: Neutrino Spectra and Uncertainties for MINOS

abstract:
  The MINOS experiment at Fermilab has released an updated result on muon
disappearance based upon 2.5 x 10^20 protons on target. The experiment utilizes
the intense source of muon neutrinos provided by the NuMI beam line. This note
summarizes the systematic uncertainties in the experiment's knowledge of the
flux and energy spectrum of the neutrinos from NuMI.


title: Polar Behavior in a Magnetic Perovskite Via A-Site Disorder

abstract:
  We elucidate a mechanism for obtaining polar behavior in magnetic perovskites
based on A-site disorder and demonstrate this mechanism by density functional
calculations for the double perovskite (La,Lu)MnNiO$_6$ with Lu concentrations
at and below 50%. We show that this material combines polar behavior and
ferromagnetism. The mechanism is quite general and may be applicable to a wide
range of magnetic perovskites.


title:
Thermal noise can facilitate energy transformation in the presence of
  entropic barriers

abstract:
  Efficiency of a Brownian particle moving along the axis of a
three-dimensional asymmetric periodic channel is investigated in the presence
of a symmetric unbiased force and a load. Reduction of the spatial
dimensionality from two or three physical dimensions to an effective
one-dimensional system entails the appearance of entropic barriers and an
effective diffusion coefficient. The energetics in the presence of entropic
barriers exhibits peculiar behavior which is different from that occurring
through energy barriers. We found that even on the quasistatic limit there is a
regime where the efficiency can be a peaked function of temperature, which
indicates that thermal noise can facilitate energy transformation, contrary to
the case of energy barriers. The appearance of entropic barriers may induce
optimized efficiency at a finite temperature.


title:
On-The-Fly Observing System of the Nobeyama 45-m and ASTE 10-m
  Telescopes

abstract:
  We have developed spectral line On-The-Fly (OTF) observing mode for the
Nobeyama Radio Observatory 45-m and the Atacama Submillimeter Telescope
Experiment 10-m telescopes. Sets of digital autocorrelation spectrometers are
available for OTF with heterodyne receivers mounted on the telescopes,
including the focal-plane 5 x 5 array receiver, BEARS, on the 45-m. During OTF
observations, the antenna is continuously driven to cover the mapped region
rapidly, resulting in high observing efficiency and accuracy. Pointing of the
antenna and readouts from the spectrometer are recorded as fast as 0.1 second.
In this paper we report improvements made on software and instruments,
requirements and optimization of observing parameters, data reduction process,
and verification of the system. It is confirmed that, using optimal parameters,
the OTF is about twice as efficient as conventional position-switch observing
method.


title:
Nature of metal-nonmetal transition in metal-ammonia solutions. II. From
  uniform metallic state to inhomogeneous electronic microstructure

abstract:
  Applying semi-analytical models of nonideal plasma, we evaluate the behavior
of the metallic phase in metal-ammonia solutions (MAS). This behavior is mainly
controlled by the degenerate electron gas, which remains stable down to 5 MPM
due to high solvent polarizability and strong dielectric screening of solvated
ions. Comparing the behavior of the metallic state with those of localized
solvated electrons, we have estimated the miscibility gap $\Delta n$ for
various alkali metals and found $\Delta n$(Na)$> \Delta n($K$)$. It is rather
narrow in Rb-NH$_3$ and does not occur in Cs-NH$_3$ solutions, which is in full
agreement with the experiments. The case of Li is discussed separately. The
difference calculated in the excess free energies of the metallic and
nonmetallic phases is in the order of $k_BT$, yielding a thermally fluctuating
mixed state at intermediate metal concentrations. It results in a continuous
metal-nonmetal (MNM) transition above the consolute point $T_c$ and a phase
separation below $T_c$. We propose a criterion for the MNM transition which may
be attributed to the line of the maximum of compressibility above $T_c$. This
line crosses the spinodal one at the critical temperature. Finally, we assert
that a new electronic phase similar to microemulsion should also arise between
the spinodal and the binodal lines.


title: "Flavored" Electric Dipole Moments in Supersymmetric Theories

abstract:
  The Standard Model (SM) predictions for the hadronic electric dipole moments
(EDMs) are well far from the present experimental resolutions, thus, the EDMs
represent very clean probes of New Physics (NP) effects. Especially, within an
MSSM framework with flavor-changing (but not necessarily CP violating) soft
terms, large and potentially visible effects to the EDMs are typically
expected. In this Letter we point out that, beyond-leading-order (BLO) effects,
so far neglected in the literature, dominate over the leading-order (LO)
effects in large regions of the parameter space, hence, their inclusion in the
evaluation of the hadronic EDMs is unavoidable.


title: Miyawaki's $F_{12}$ Spinor L-function Conjecture

abstract:
  In this paper we prove the Miyawaki conjecture related to the spinor
$L$--function of a Siegel cusp form of weight 12 and degree 3 as a special
example of results related to Miyawaki lifts of odd degree.


title: The shape of invasion perclation clusters in random and correlated media

abstract:
  The shape of two-dimensional invasion percolation clusters are studied
numerically for both non-trapping (NTIP) and trapping (TIP) invasion
percolation processes. Two different anisotropy quantifiers, the anisotropy
parameter and the asphericity are used for probing the degree of anisotropy of
clusters. We observe that in spite of the difference in scaling properties of
NTIP and TIP, there is no difference in the values of anisotropy quantifiers of
these processes. Furthermore, we find that in completely random media, the
invasion percolation clusters are on average slightly less isotropic than
standard percolation clusters. Introducing isotropic long-range correlations
into the media reduces the isotropy of the invasion percolation clusters. The
effect is more pronounced for the case of persisting long-range correlations.
The implication of boundary conditions on the shape of clusters is another
subject of interest. Compared to the case of free boundary conditions, IP
clusters of conventional rectangular geometry turn out to be more isotropic.
Moreover, we see that in conventional rectangular geometry the NTIP clusters
are more isotropic than TIP clusters.


title: Study of Structure of the Mass Gap between Two Spin Multiplets

abstract:
  Studying our semirelativistic potential model and the numerical results,
which succeeds in predicting and reproducing recently discovered higher
resonances of $D$, $D_s$, $B$, and $B_s$, we find a simple expression for the
mass gap between two spin multiplets of heavy-light mesons, $(0^-,1^-)$ and
$(0^+,1^+)$. The mass gap between chiral partners defined by $\Delta
M=M(0^+)-M(0^-)$ and/or $M(1^+)-M(1^-)$ is given by $\Delta
M=M(0^+)-M(0^-)=M(1^+)-M(1^-)\approx \Lambda_{\rm Q}-m_q$ in the limit of heavy
quark symmetry. We also study the case including $1/m_Q$ corrections.


title: Regimes of Precursor-Mediated Epitaxial Growth

abstract:
  A discussion of epitaxial growth is presented for those situations (OMVPE,
CBE, ALE, MOMBE, GSMBE, etc.) when the kinetics of surface processes associated
with molecular precursors may be rate limiting. Emphasis is placed on the
identification of various {\it characteristic length scales} associated with
the surface processes. Study of the relative magnitudes of these lengths
permits one to identify regimes of qualitatively different growth kinetics as a
function of temperature and deposition flux. The approach is illustrated with a
simple model which takes account of deposition, diffusion, desorption,
dissociation, and step incorporation of a single precursor species, as well as
the usual processes of atomic diffusion and step incorporation. Experimental
implications are discussed in some detail.


title:
Numerically exact Green functions from Hirsch-Fye quantum Monte Carlo
  simulations

abstract:
  We present a new method for extracting numerically exact imaginary-time Green
functions from standard Hirsch-Fye quantum Monte Carlo (HF-QMC) simulations
within dynamical mean-field theory. By analytic continuation, angular resolved
spectra are obtained without the discretization bias previously associated with
HF-QMC results. The method is shown to be accurate even at very low
temperatures (T=W/800 for bandwidth W) in the strongly correlated regime.


title:
Second Order Gravitational Effects on CMB Temperature Anisotropy in
  Lambda dominated flat universes

abstract:
  We study second order gravitational effects of local inhomogeneities on the
cosmic microwave background radiation in flat universes with matter and a
cosmological constant $\Lambda$. We find that the general relativistic
correction to the Newtonian approximation is negligible at second order
provided that the size of the inhomogeneous region is sufficiently smaller than
the horizon scale. For a spherically symmetric top-hat type quasi-linear
perturbation, the first order temperature fluctuation corresponding to the
linear integrated Sachs-Wolfe (ISW) effect is enhanced(suppressed) by the
second order one for a compensated void(lump). As a function of redshift of the
local inhomogeneity, the second order temperature fluctuations due to evolution
of the gravitational potential have a peak before the matter-$\Lambda$ equality
epoch for a fixed comoving size and a density contrast. The second order
gravitational effects from local quasi-linear inhomogeneities at a redshift z~1
may significantly affect the cosmic microwave background.


title: Two-body scattering without angular-momentum decomposition

abstract:
  Two-body scattering is studied by solving the Lippmann-Schwinger equation in
momentum space without angular-momentum decomposition for a local spin
dependent short range interaction plus Coulomb. The screening and
renormalization approach is employed to treat the Coulomb interaction.
Benchmark calculations are performed by comparing our procedure with
partial-wave calculations in configuration space for p-10Be, p-16O and 12C-10Be
elastic scattering, using a simple optical potential model.


title:
Interplay between carrier localization and magnetism in diluted magnetic
  and ferromagnetic semiconductors

abstract:
  The presence of localized spins exerts a strong influence on quantum
localization in doped semiconductors. At the same time carrier-mediated
interactions between the localized spins are modified or even halted by
carriers' localization. The interplay of these effects is discussed for II-VI
and III-V diluted magnetic semiconductors. This insight is exploited to
interpret the complex dependence of resistance on temperature, magnetic field,
and concentration of valence-band holes in (Ga,Mn)As. In particular, high field
negative magnetoresistance results from the orbital weak localization effect.
The resistance maximum and the associated negative magnetoresistance near the
Curie temperature are assigned to the destructive influence of preformed
ferromagnetic bubbles on the "antilocalization" effect driven by
disorder-modified carrier-carrier interactions. These interactions account also
for the low-temperature increase of resistance. Furthermore, the sensitivity of
conductance to spin splitting and to scattering by spin disorder may explain
resistance anomalies at coercive fields, where relative directions of external
and molecular fields change.


title:
Forward virtual Compton scattering and the Lamb shift in chiral
  perturbation theory

abstract:
  We compute the spin-independent structure functions of the forward
virtual-photon Compton tensor of the proton at one loop using heavy baryon
chiral perturbation theory and dispersion relations. We study the relation
between both approaches. We use these results to generalize some sum rules to
virtual photon transfer momentum and relate them with sum rules in deep
inelastic scattering. We then compute the leading chiral term of the
polarizability correction to the Lamb shift of the hydrogen and muonic
hydrogen. We obtain -87.05/n^3 Hz and -0.148/n^3 meV for the correction to the
hydrogen and muonic hydrogen Lamb shift respectively.


title: The Walsh model for $M_2^{*}$ Carleson

abstract:
  We study the Walsh model of a certain maximal truncation of Carleson's
operator, related to the Return Times Theorem from Ergodic Theory.


title: A generalization of inversion formulas of Pestov and Uhlmann

abstract:
  In this note, we give a generalization of the inversion formulas of
Pestov-Uhlmann for the geodesic ray transform of functions and vector fields on
simple 2-dimensional manifolds of constant curvature. The inversion formulas
given here hold for 2-dimensional simple manifolds whose curvatures close to a
constant.


title:
The Structure of the Local Supercluster of Galaxies Revealed by the
  Three-Dimensional Voronoi's Tessellation Method

abstract:
  3D Voronoi's tessellation method was first applied to identify groups of
galaxies in the structure of a supercluster. The sample under consideration
consists of more than 7000 galaxies of the Local Supercluster (LS) with radial
velocities up to 3100 km/s. Because of an essential non-homogeneity of the LS
catalogue, it was proposed to overscale distances in such an ''artificial'' way
that the concentration of galaxies was varying as with increase of the distance
a power-behaved function with the same exponent beta as for the full
homogeneous catalogue. Various parameters of clustering were taking into
account: alpha (0.01, 0.1, 1%) as the part of galaxies, which have the relative
volume of a Voronoi's cell smaller than the critical one for the random
distribution; beta = 0, which fits to the random galaxy distribution; beta =
0.7, which is close to the pancake galaxy distribution. It is revealed that
Voronoi's tessellation method depends weakly on beta-parameter, and the number
of galaxies in rich structures is growing rather than in poor ones with
increase of alpha-parameter. The comparison of the groups derived with the
groups obtained by Karachentsev's dynamical method shows that the number of
groups, which coincides by all the components, is 22%. As a whole, the
dynamical method is more preferred for identifying sparsely populated galaxy
groups, whereas 3D Voronoi's tessellation method is preferred for more
populated ones.


title: On the classification of gradient Ricci solitons

abstract:
  We show that the only complete shrinking gradient Ricci solitons with
vanishing Weyl tensor are quotients of the standard ones. This gives a new
proof of the Hamilton-Ivey-Perel'man classification of 3-dimensional shrinking
gradient solitons. We also prove a classification for expanding gradient Ricci
solitons with constant scalar curvature and suitably decaying Weyl tensor.


title: Stability of strong ideal-gas shock layers

abstract:
  Extending recent results in the isentropic case, we use a combination of
asymptotic ODE estimates and numerical Evans-function computations to examine
the spectral stability of shock-wave solutions of the compressible
Navier--Stokes equations with ideal gas equation of state. Our main results are
that, in appropriately rescaled coordinates, the Evans function associated with
the linearized operator about the wave (i) converges in the large-amplitude
limit to the Evans function for a limiting shock profile of the same equations,
for which internal energy vanishes at one endstate; and (ii) has no unstable
(positive real part) zeros outside a uniform ball $|\lambda|\le \Lambda$. Thus,
the rescaled eigenvalue ODE for the set of all shock waves, augmented with the
(nonphysical) limiting case, form a compact family of boundary-value problems
that can be conveniently investigated numerically. An extensive numerical
Evans-function study yields one-dimensional spectral stability, independent of
amplitude, for gas constant $\gamma$ in $[1.2, 3]$ and ratio $\nu/\mu$ of heat
conduction to viscosity coefficient within $[0.2,5]$ ($\gamma\approx 1.4$,
$\nu/\mu\approx 1.47$ for air). Other values may be treated similarly but were
not considered. The method of analysis extends also to the multi-dimensional
case, a direction that we shall pursue in a future work.


title:
Equidistribution of Horocyclic Flows on Complete Hyperbolic Surfaces of
  Finite Area

abstract:
  We provide a self-contained, accessible introduction to Ratner's
Equidistribution Theorem in the special case of horocyclic flow on a complete
hyperbolic surface of finite area. This equidistribution result was first
obtained in the early 1980s by Dani and Smillie and later reappeared as an
illustrative special case of Ratner's work on the equidistribution of unipotent
flows in homogeneous spaces. We also prove an interesting probabilistic result
due to Breuillard: on the modular surface an arbitrary uncentered random walk
on the horocycle through almost any point will fail to equidistribute, even
though the horocycles are themselves equidistributed. In many aspects of this
exposition we are indebted to Bekka and Mayer's more ambitious survey, "Ergodic
Theory and Topological Dynamics for Group Actions on Homogeneous Spaces."


title: The maximum spectral radius of C_4-free graphs of given order and size

abstract:
  Let G be a graph of n vertices and m edges, and let G has no cycles of length
4. We give upper bounds on the adjacency spectral radius of G in terms of n and
m.


title:
Spectrum of the product of Toeplitz matrices with application in
  probability

abstract:
  We study the spectrum of the product of two Toeplitz operators. Assume that
the symbols of these operators are continuous and real-valued and that one of
them is non-negative. We prove that the spectrum of the product of finite
section Toeplitz matrices converges to the spectrum of the product of the
semi-infinite Toeplitz operators. We give an example showing that the supremum
of this set is not always the supremum of the product of the two symbols.
Finally, we provide an application in probability which is the first motivation
of this study. More precisely, we obtain a large deviation principle for
Gaussian quadratic forms.


title: Aftershock identification

abstract:
  Earthquake aftershock identification is closely related to the question "Are
aftershocks different from the rest of earthquakes?" We give a positive answer
to this question and introduce a general statistical procedure for clustering
analysis of seismicity that can be used, in particular, for aftershock
detection. The proposed approach expands the analysis of Baiesi and Paczuski
[PRE, 69, 066106 (2004)] based on the space-time-magnitude nearest-neighbor
distance $\eta$ between earthquakes. We show that for a homogeneous Poisson
marked point field with exponential marks, the distance $\eta$ has Weibull
distribution, which bridges our results with classical correlation analysis for
unmarked point fields. We introduce a 2D distribution of spatial and temporal
components of $\eta$, which allows us to identify the clustered part of a point
field. The proposed technique is applied to several synthetic seismicity models
and to the observed seismicity of Southern California.


title:
Electronic structure of copper intercalated transition metal
  dichalcogenides: First-principles calculations

abstract:
  We report first principles calculations, within density functional theory, of
copper intercalated titanium diselenides, CuxTiSe2, for values of x ranging
from 0 to 0.11. The effect of intercalation on the energy bands and densities
of states of the host material is studied in order to better understand the
cause of the superconductivity that was recently observed in these structures.
We find that charge transfer from the copper atoms to the metal dichalcogenide
host layers causes a gradual reduction in the number of holes in the otherwise
semi-metallic pristine TiSe2, thus suppressing the charge density wave
transition at low temperatures, and a corresponding increase in the density of
states at the Fermi level. These effects are probably what drive the
superconducting transition in the intercalated systems.


title:
Thermal and surface anisotropy effects on the magnetization reversal of
  a nanocluster

abstract:
  The relaxation rate and temperature-dependent switching field curve of a
spherical magnetic nanocluster are calculated by taking into account the effect
of surface anisotropy via an effective anisotropy model. In particular, it is
shown that surface anisotropy may change the thermally activated magnetization
reversal by more than an order of magnitude, and that temperature-dependent
switching field curves noticeably deviate from the Stoner-Wohlfarth astroid.
With recent and future $\mu$-SQUID measurements in mind, we indicate how
comparison of our results with experimental data on isolated clusters may allow
one to obtain valuable information on surface anisotropy.


title:
Enhanced grain surface effect on magnetic properties of nanometric
  La0.7Ca0.3MnO3 manganite : Evidence of surface spin freezing of manganite
  nanoparticles

abstract:
  We have investigated the effect of nanometric grain size on magnetic
properties of single phase, nanocrystalline, granular La0.7Ca0.3MnO3 (LCMO)
sample. We have considered core-shell structure of our LCMO nanoparticles,
which can explain its magnetic properties. From the temperature dependence of
field cooled (FC) and zero-field cooled (ZFC) dc magnetization (DCM), the
magnetic properties could be distinguished into two regimes: a relatively high
temperature regime T > 40 K where the broad maximum of ZFC curve (at T = Tmax)
is associated with the blocking of core particle moments, whereas the sharp
maximum (at T = TS) is related to the freezing of surface (shell) spins. The
unusual shape of M (H) loop at T = 1.5 K, temperature dependent feature of
coercive field and remanent magnetization give a strong support of surface spin
freezing that are occurring at lower temperature regime (T < 40 K) in this LCMO
nanoparticles. Additionally, waiting time (tw) dependence of ZFC relaxation
measurements at T = 50 K show weak dependence of relaxation rate [S(t)] on tw
and dM/dln(t) following a logarithmic variation on time. Both of these features
strongly support the high temperature regime to be associated with the blocking
of core moments. At T = 20 K, ZFC relaxation measurements indicates the
existence of two different types of relaxation processes in the sample with
S(t) attaining a maximum at the elapsed time very close to the wait time tw =
1000 sec, which is an unequivocal sign of glassy behavior. This age-dependent
effect convincingly establish the surface spin freezing of our LCMO
nanoparticles associated with a background of superparamagnetic (SPM) phase of
core moments.


title:
Arsenic uptake by gypsum and calcite: Modeling and probing by neutron
  and x-ray scattering

abstract:
  Here we report on two structural studies performed on As-doped gypsum (CaSO4
2H2O) and calcite (CaCO3), using neutron (D20-ILL) and x-ray (ID11-ESRF)
diffraction data and EXAFS (BM8-ESRF). The aim of this study is to determine
whether As gets into the bulk of gypsum and calcite structures or is simply
adsorbed on the surface. Different mechanisms of substitution are used as
hypotheses. The combined Rietveld analysis of neutron and x-ray diffraction
data shows an expansion of the unit cell volume proportional to the As
concentration within the samples. DFT-based simulations confirm the increase of
the unit cell volume proportional to the amount of carbonate or sulphate groups
substituted. Interpolation of the experimental Rietveld data allows us to
distinguish As substituted within the structure from that adsorbed on the
surface of both minerals.


title:
Outflow-Dominated Emission from the Quiescent Massive Black Holes in NGC
  4621 and NGC 4697

abstract:
  The nearby elliptical galaxies NGC 4621 and NGC 4697 each host a supermassive
black hole with a mass more than 1e8 Solar masses. Analysis of archival Chandra
data and new NRAO Very Large Array data shows that each galaxy contains a
low-luminosity active galactic nucleus (LLAGN), identified as a faint, hard
X-ray source that is astrometrically coincident with a faint 8.5-GHz source.
The latter has a diameter less than 0.3 arcsec (26 pc for NGC 4621, 17 pc for
NGC 4697). The black holes energizing these LLAGNs have Eddington ratios L(2-10
keV) / L(Edd) ~ 1e-9, placing them in the so-called quiescent regime. The
emission from these quiescent black holes is radio-loud, with log Rx = log
nuLnu(8.5 GHz) / L(2-10 keV) ~ -2, suggesting the presence of a radio outflow.
Also, application of the radio-X-ray-mass relation from Yuan & Cui for
quiescent black holes predicts the observed radio luminosities nuLnu(8.5 GHz)
to within a factor of a few. Significantly, that relation invokes X-ray
emission from the outflow rather than from an accretion flow. The faint, but
detectable, emission from these two massive black holes is therefore consistent
with being outflow-dominated. Observational tests of this finding are
suggested.


title: Complex base numeral systems

abstract:
  In this paper will be introduced large, probably complete family of complex
base systems, which are 'proper' - for each point of the space there is a
representation which is unique for all but some zero measure set. The condition
defining this family is the periodicity - we get periodic covering of the plane
by fractals in hexagonal-type structure, what can be used for example in image
compression. There will be introduced full methodology of analyzing and using
this approach - both for the integer part: periodic lattice and the fractional:
attractor of some IFS, for which the convex hull or properties like dimension
of the boundary can be found analytically. There will be also shown how to
generalize this approach to higher dimensions and found some proper systems in
dimension 3.


title: About Algorithm for Transformation of Logic Functions (ATLF)

abstract:
  In this article the algorithm for transformation of logic functions which are
given by truth tables is considered. The suggested algorithm allows the
transformation of many-valued logic functions with the required number of
variables and can be looked in this sense as universal.


title:
Model-Independent and Quasi-Model-Independent Search for New Physics at
  CDF

abstract:
  Data collected in Run II of the Fermilab Tevatron are searched for
indications of new electroweak scale physics. Rather than focusing on
particular new physics scenarios, CDF data are analyzed for discrepancies with
respect to the standard model prediction. A model-independent approach (Vista)
considers the gross features of the data, and is sensitive to new large cross
section physics. A quasi-model-independent approach (Sleuth) searches for a
significant excess of events with large summed transverse momentum, and is
particularly sensitive to new electroweak scale physics that appears
predominantly in one final state. This global search for new physics in over
three hundred exclusive final states in 927 pb^-1 of ppbar collisions at
sqrt(s)=1.96 TeV reveals no such significant indication of physics beyond the
standard model.


title:
A delay differential model of ENSO variability: Parametric instability
  and the distribution of extremes

abstract:
  We consider a delay differential equation (DDE) model for El-Nino Southern
Oscillation (ENSO) variability. The model combines two key mechanisms that
participate in ENSO dynamics: delayed negative feedback and seasonal forcing.
We perform stability analyses of the model in the three-dimensional space of
its physically relevant parameters. Our results illustrate the role of these
three parameters: strength of seasonal forcing $b$, atmosphere-ocean coupling
$\kappa$, and propagation period $\tau$ of oceanic waves across the Tropical
Pacific. Two regimes of variability, stable and unstable, are separated by a
sharp neutral curve in the $(b,\tau)$ plane at constant $\kappa$. The detailed
structure of the neutral curve becomes very irregular and possibly fractal,
while individual trajectories within the unstable region become highly complex
and possibly chaotic, as the atmosphere-ocean coupling $\kappa$ increases. In
the unstable regime, spontaneous transitions occur in the mean ``temperature''
({\it i.e.}, thermocline depth), period, and extreme annual values, for purely
periodic, seasonal forcing. The model reproduces the Devil's bleachers
characterizing other ENSO models, such as nonlinear, coupled systems of partial
differential equations; some of the features of this behavior have been
documented in general circulation models, as well as in observations. We
expect, therefore, similar behavior in much more detailed and realistic models,
where it is harder to describe its causes as completely.


title:
The black hole dynamical horizon and generalized second law of
  thermodynamics

abstract:
  The generalized second law of thermodynamics for a system containing a black
hole dynamical horizon is proposed in a covariant way. Its validity is also
tested in case of adiabatically collapsing thick light shells.


title:
Deuteron frozen spin polarized target for nd experiements at the VdG
  accelerator of Charles University

abstract:
  A frozen spin polarized deuteron target cooled by the 3He/4He dilution
refrigerator is described. Fully deuterated 1,2-propanediol was used as a
target material. Deuteron vector polarization about 40% was obtained for the
target in the shape of a cylinder of 2 cm diameter and 6 cm length. The target
is intended for a study of 3N interactions at the polarized neutron beam
generated by the Van de Graaff accelerator at the Charles University in Prague.


title: The Meaning of Dimensions

abstract:
  We review the current status of dimensions, as the result of a long and
controversial history that includes input from philosophy and physics. Our
conclusion is that they are subjective but essential concepts which provide a
kind of book-keeping device, their number increasing as required by advances in
physics. The world almost certainly has more than the four dimensions of space
and time, but the introduction of the fifth and higher dimensions requires a
careful approach wherein known results are embedded and new ones are couched in
the most productive manner.


title:
Hierarchical Disk Galaxy Assembly as the Origin of Scatter in the z~1
  Stellar Mass Tully-Fisher Relation

abstract:
  Recent observations of distant disk galaxies show that there is little to no
evolution in the relation between maximum rotation speed and stellar mass at z
< 1.2. There is however a significant scatter between these two quantities
whose origin is uncertain. We show in this paper that this scatter is at least
partially the result of galaxy merging, revealing that disk galaxy growth at z
< 1 is fundamentally hierarchical. We carry this out by calculating CAS
(concentration, asymmetry, clumpiness) structural parameters using archival
Hubble Space Telescope imaging of 91 high-redshift disk galaxies at 0.4 < z <
1.0 with robustly measured stellar masses and rotational maximum velocities
taken from Conselice et al. (2005). We separate our sample into two redshift
bins divided at z = 0.7, and investigate deviations from the stellar-mass
Tully-Fisher relation in both the M_* and V_max directions, and how these
correlate with structural asymmetries. We find a significant (> 3 sigma)
correlation between the residuals from the stellar-mass Tully-Fisher relation
in both the M_* and V_max directions, and high asymmetries. This result holds
after we remove contributions from star formation and edge-on galaxies which
can produce higher asymmetries unrelated to merging. While there are a few
cases in which our disk galaxies have very large asymmetries, and are
potentially involved in major mergers, in general these asymmetries are smaller
than the major merger limit. It is therefore likely that these galaxies are
forming hierarchically through minor galaxy mergers, which is also suggested by
the constant slope and zero point of the stellar mass Tully-Fisher relation
during the same epoch.


title:
How to facet a gemstone: from potential modularity to the proof of
  Serre's modularity conjecture

abstract:
  In this survey paper we present recent results obtained by Khare,
Wintenberger and the author that have led to a proof of Serre's conjecture,
such as existence of compatible families, modular upper bounds for universal
deformation rings and existence of minimal lifts, prime switching and
modularity propagation, weight reduction (via existence of conjugates) and
(iterated) killing ramification.
  The main tools used in the proof of these results are modularity lifting
theorems a la Wiles and a result of potential modularity due to R. Taylor.


title: The Einstein-Podolsky-Rosen Argument and the Bell Inequalities

abstract:
  In 1935 Einstein, Podolsky, and Rosen (EPR) published an important paper in
which they claimed that the whole formalism of quantum mechanics together with
what they called "Reality Criterion" imply that quantum mechanics cannot be
complete. That is, there must exist some elements of reality that are not
described by quantum mechanics. There must be, they concluded, a more complete
description of physical reality behind quantum mechanics. There must be a
state, a hidden variable, characterizing the state of affairs in the world in
more details than the quantum mechanical state, something that also reflects
the missing elements of reality.
  Under some further but quite plausible assumptions, this conclusion implies
that in some spin-correlation experiments the measured quantum mechanical
probabilities should satisfy particular inequalities (Bell-type inequalities).
The paradox consists in the fact that quantum probabilities do not satisfy
these inequalities. And this paradoxical fact has been confirmed by several
laboratory experiments in the last three decades. The problem is still open and
hotly debated among both physicists and philosophers. It has motivated a wide
range of research from the most fundamental quantum mechanical experiments
through foundations of probability theory to the theory of stochastic causality
as well as the metaphysics of free will.


title: A homotopy theory for enrichment in simplicial modules

abstract:
  We put a Quillen model structure on the category of small categories enriched
in simplicial $k$-modules and non-negatively graded chain complexes of
$k$-modules, where $k$ is a commutative ring. The model structure is obtained
by transfer from the model structure on simplicial categories due to J.
Bergner.


title: A beginner's guide to forcing

abstract:
  This expository paper, aimed at the reader without much background in set
theory or logic, gives an overview of Cohen's proof (via forcing) of the
independence of the continuum hypothesis. It emphasizes the broad outlines and
the intuitive motivation while omitting most of the proofs. The reader must of
course consult standard textbooks for the missing details, but this article
provides a map of the forest so that the beginner will not get lost while
forging through the trees.


title:
Singularity theorems and the Lorentzian splitting theorem for the
  Bakry-Emery-Ricci tensor

abstract:
  We consider the Hawking-Penrose singularity theorems and the Lorentzian
splitting theorem under the weaker curvature condition of nonnegative
Bakry-Emery-Ricci curvature $Ric_f^m$ in timelike directions. We prove that
they still hold when $m$ is finite, and when $m$ is infinite, they hold under
the additional assumption that $f$ is bounded from above.


title:
Anomalous double peak structure in Nb/Ni superconductor/ferromagnet
  tunneling DOS

abstract:
  We have experimentally investigated the density of states (DOS) in Nb/Ni
(S/F) bilayers as a function of Ni thickness, $d_F$. Our thinnest samples show
the usual DOS peak at $\pm\Delta_0$, whereas intermediate-thickness samples
have an anomalous ``double-peak'' structure. For thicker samples ($d_F \geq
3.5$ nm), we see an ``inverted'' DOS which has previously only been reported in
superconductor/weak-ferromagnet structures. We analyze the data using the
self-consistent non-linear Usadel equation and find that we are able to
quantitatively fit the features at $\pm\Delta_0$ if we include a large amount
of spin-orbit scattering in the model. Interestingly, we are unable to
reproduce the sub-gap structure through the addition of any parameter(s).
Therefore, the observed anomalous sub-gap structure represents new physics
beyond that contained in the present Usadel theory.


title:
Aperiodic order via dynamical systems: Diffraction for sets of finite
  local complexity

abstract:
  We give an introduction into diffraction theory for aperiodic order. We focus
on an approach via dynamical systems and the phenomenon of pure point
diffraction. We review recent results and sketch proofs. We then present a new
uniform Wiener/Wintner type result generalizing various earlier results of this
type.


title: Koszul differential graded algebras and BGG correspondence

abstract:
  The concept of Koszul differential graded algebra (Koszul DG algebra) is
introduced. Koszul DG algebras exist extensively, and have nice properties
similar to the classic Koszul algebras. A DG version of the Koszul duality is
proved. When the Koszul DG algebra $A$ is AS-regular, the Ext-algebra $E$ of
$A$ is Frobenius. In this case, similar to the classical BGG correspondence,
there is an equivalence between the stable category of finitely generated left
$E$-modules, and the quotient triangulated category of the full triangulated
subcategory of the derived category of right DG $A$-modules consisting of all
compact DG modules modulo the full triangulated subcategory consisting of all
the right DG modules with finite dimensional cohomology. The classical BGG
correspondence can derived from the DG version.


title: Quantum Circuits Architecture

abstract:
  We present a method for optimizing quantum circuits architecture. The method
is based on the notion of "quantum comb", which describes a circuit board in
which one can insert variable subcircuits. The method allows one to efficiently
address novel kinds of quantum information processing tasks, such as
storing-retrieving, and cloning of channels.


title: Mirror World with Broken Mirror Parity, E(6) Unification and Cosmology

abstract:
  In the present paper we have developed a concept of parallel ordinary (O) and
mirror (M) worlds. We have shown that in the case of a broken mirror parity
(MP), the evolutions of fine structure constants in the O- and M-worlds are not
identical. It is assumed that E_6-unification inspired by superstring theory
restores the broken MP at the scale \sim 10^{18} GeV, what unavoidably leads to
the different E_6-breakdowns at this scale: E_6 \to SO(10)\times U(1)_Z - in
the O-world, and E'_6 \to SU(6)'\times SU(2)'_Z - in the M-world. Considering
only asymptotically free theories, we have presented the running of all the
inverse gauge constants \alpha_i^{-1} in the one-loop approximation. Then a
`quintessence' scenario is discussed for our model of accelerating universe.
Such a scenario is related with an axion (`acceleron') of a new gauge group
SU(2)'_Z which has a coupling constant g_Z extremely growing at the scale
\Lambda_Z\sim 10^{-3} eV.


title: Classification of Cohomogeneity One Manifolds in Low Dimensions

abstract:
  A cohomogeneity one manifold is a manifold with the action of a compact Lie
group, whose quotient is one dimensional. Such manifolds are of interest in
Riemannian geometry, in the context of nonnegative sectional curvature, as well
as in other areas of geometry and in physics. In this paper we classify compact
simply connected cohomogeneity one manifolds in dimensions 5, 6 and 7. We also
show that all such manifolds admit metrics of nonnegative sectional curvature,
with the possible exception of two families of manifolds.


title: When Are Torsionless Modules Projective?

abstract:
  In this paper, we study the problem when a finitely generated torsionless
module is projective. Let $\Lambda$ be an Artinian local algebra with radical
square zero. Then a finitely generated torsionless $\Lambda$-module $M$ is
projective if ${\rm Ext^1_\Lambda}(M,M)=0$. For a commutative Artinian ring
$\Lambda$, a finitely generated torsionless $\Lambda$-module $M$ is projective
if the following conditions are satisfied: (1) ${\rm
Ext}^i_{\Lambda}(M,\Lambda)=0$ for $i=1,2,3$; and (2) ${\rm
Ext}^i_{\Lambda}(M,M)=0$ for $i=1,2$. As a consequence of this result, we have
that for a commutative Artinian ring $\Lambda$, a finitely generated Gorenstein
projective $\Lambda$-module is projective if and only if it is selforthogonal.


title:
Strong non-collapsing and uniform Sobolev inequalities for Ricci flow
  with surgeries

abstract:
  We prove a uniform Sobolev inequality for Ricci flow, which is independent of
the number of surgeries. As an application, under less assumptions, a
non-collapsing result stronger than Perelman's $\kappa$ non-collapsing with
surgery is derived. The proof is shorter and seems more accessible. The result
also improves some earlier ones where the Sobolev inequality depended on the
number of surgeries.


title: Discovery of a bipolar X-ray jet from the T Tauri star DG Tau

abstract:
  We have obtained and analyzed Chandra ACIS-S observations of the strongly
accreting classical T Tauri star DG Tau. Our principal goals are to map the
immediate environment of the star to characterize possible extended X-rays
formed in the jet, and to re-visit the anomalous, doubly absorbed X-ray
spectrum of DG Tau itself. We combine our new ACIS-S data with a data set
previously obtained. The data are superimposed to obtain flux and hardness
images. Separate X-ray spectra are extracted for DG Tau and areas outside its
point spread function. We detect a prominent X-ray jet at a position angle of
PA ~225 deg (tentatively suggested by Guedel et al. 2005), coincident with the
optical jet axis. We also identify a counter jet at PA = 45 deg. The X-ray jets
are detected out to a distance of ~5" from the star, their sources being
extended at the ACIS-S resolution. The jet spectra are soft, with a best-fit
electron temperature of 3.4 MK. We find evidence for excess absorption of the
counter jet. The spectrum of the DG Tau point source shows two components with
largely different temperatures and absorption column densities. The similar
temperatures and small absorbing gas columns of the jet sources and the soft
component of the "stellar" source suggest that these sources are related,
produced either by shocks or by magnetic heating in the jets. Cooling estimates
suggest that the pressure in the hot gas contributes to jet expansion. The hard
"stellar" component, on the other hand, is associated with a stellar corona or
magnetosphere. The excessive photoelectric absorption of this component
suggests the presence of dust-depleted accretion streams above coronal magnetic
fields.


title:
Super-linear elliptic equation for the Pucci operator without growth
  restrictions for the data

abstract:
  In this paper we deal with existence and uniqueness of solution to
super-linear problems for the Pucci operator: $$ -\M^+(D^2u)+|u|^{s-1}u=f(x)
\quad {in} \RR^n, $$ where $s>1$ and $f$ satisfies only local integrability
conditions. This result is well known when, instead of the Pucci operator, the
Laplacian or a divergence form operator is considered. Our existence results
use the Alexandroff-Bakelman-Pucci inequality since we cannot use any
variational formulation. For radially symmetric $f$ we can prove our results
under less local integrability assumptions, taking advantage of an appropriate
variational formulation. We also obtain an existence result with boundary
explosion in smooth domains.


title: Ramanujan-type formulae for $1/\pi$: A second wind?

abstract:
  In 1914 S. Ramanujan recorded a list of 17 series for $1/\pi$. We survey the
methods of proofs of Ramanujan's formulae and indicate recently discovered
generalizations, some of which are not yet proven.


title:
Non-intersecting squared Bessel paths and multiple orthogonal
  polynomials for modified Bessel weights

abstract:
  We study a model of $n$ non-intersecting squared Bessel processes in the
confluent case: all paths start at time $t = 0$ at the same positive value $x =
a$, remain positive, and are conditioned to end at time $t = T$ at $x = 0$. In
the limit $n \to \infty$, after appropriate rescaling, the paths fill out a
region in the $tx$-plane that we describe explicitly. In particular, the paths
initially stay away from the hard edge at $x = 0$, but at a certain critical
time $t^*$ the smallest paths hit the hard edge and from then on are stuck to
it. For $t \neq t^*$ we obtain the usual scaling limits from random matrix
theory, namely the sine, Airy, and Bessel kernels. A key fact is that the
positions of the paths at any time $t$ constitute a multiple orthogonal
polynomial ensemble, corresponding to a system of two modified Bessel-type
weights. As a consequence, there is a $3 \times 3$ matrix valued
Riemann-Hilbert problem characterizing this model, that we analyze in the large
$n$ limit using the Deift-Zhou steepest descent method. There are some novel
ingredients in the Riemann-Hilbert analysis that are of independent interest.


title:
Radiatively Induced Spontaneous Symmetry Breaking by Wilson Line in a
  Warped Extra Dimension

abstract:
  We investigate the dynamical gauge-Higgs unification in the Randall-Sundrum
(RS) space-time. We study the dynamical gauge-Higgs unification in the SU(2)
gauge theory with a bulk fermion in the RS space-time. We evaluate the
contribution from fermion loop to the one-loop effective potential with respect
to the Wilson-line phase, and study the dynamical gauge symmetry breaking. We
also apply this mechanism of the gauge symmetry breaking to the electroweak
gauge-Higgs unification in the RS space-time. Especially we numerically studied
a SU(3)_w gauge model as a toy model of electroweak gauge-Higgs unification in
the RS space-time. We introduce an adjoint fermion into the model to break the
gauge symmetry and to obtain the U(1)_em electromagnetic symmetry. We found
that in this model the ratio of Z-boson mass to W-boson varies with respect to
the Wilson-line phase even at the tree level. We also propose a dynamical
mechanism of tuning the ratio m_Z/m_W to the experimental value
91.2GeV/80.4GeV=1.13 by introducing bulk scalars or bulk fermions with twisted
boundary conditions. In these models the Higgs can vary in mass between zero
and 290GeV.


title: Discrimination of particle masses in multivariant space-time geometry

abstract:
  Multivariance of geometry means that at the point $P_{0}$ there exist many
vectors $P_{0}P_{1}$, $\P_{0}P_{2}$,... which are equivalent (equal) to the
vector $\Q_{0}Q_{1}$ at the point $Q_{0}$, but they are not equivalent between
themselves. The discrimination capacity (zero-variance) of geometry appears,
when at the point $P_{0}$ there are no vectors, which are equivalent to the
vector $Q_{0}Q_{1}$ at the point $Q_{0}$. It is shown, that in some
multivariant space-time geometries some particles of small mass may be
discriminated (i.e. either they do not exist, or their evolution is
impossible). The possibility of some particle discrimination may appear to be
important for explanation of the discrete character of mass spectrum of
elementary particles.


title:
$\pi$ and $\sigma$ mesons at finite temperature and density in the NJL
  model with dimensional regularization

abstract:
  Dynamical Symmetry breaking and meson masses are studied in the
Nambu-Jona-Lasinio (NJL) model at finite temperature and chemical potential
using the dimensional regularization. Since the model is not renormalizable in
four space-time dimensions, physical results and parameters depend on the
regularization method. Following the imaginary time formalism, we introduce the
temperature, $T$ and the chemical potential, $\mu$. The parameters in the model
are fixed by calculating the pion mass and decay constant in the dimensional
regularization at $T=\mu=0$.


title: Axiomatizing rational power series

abstract:
  Iteration semirings are Conway semirings satisfying Conway's group
identities. We show that the semirings $\N^{\rat}\llangle \Sigma^* \rrangle$ of
rational power series with coefficients in the semiring $\N$ of natural numbers
are the free partial iteration semirings. Moreover, we characterize the
semirings $\N_\infty^{\rat}\llangle \Sigma^* \rrangle$ as the free semirings in
the variety of iteration semirings defined by three additional simple
identities, where $\N_\infty$ is the completion of $\N$ obtained by adding a
point of infinity. We also show that this latter variety coincides with the
variety generated by the complete, or continuous semirings. As a consequence of
these results, we obtain that the semirings $\N_\infty^{\rat}\llangle \Sigma^*
\rrangle$, equipped with the sum order, are free in the class of symmetric
inductive $^*$-semirings. This characterization corresponds to Kozen's
axiomatization of regular languages.


title:
On the Subpulse Modulation, Polarization and Subbeam Carousel
  Configuration of Pulsar B1857--26

abstract:
  New GMRT observations of the five-component pulsar B1857--26 provide detailed
insight into its pulse-sequence modulation phenomena for the first time. The
outer conal components exhibit a 7.4-rotation-period, longitude-stationary
modulation. Several lines of evidence indicate a carousel circulation time
$\P3hat$ of about 147 stellar rotations, characteristic of a pattern with 20
beamlets. The pulsar nulls some 20% of the time, usually for only a single
pulse, and these nulls show no discernible order or periodicity. Finally, the
pulsar's polarization-angle traverse raises interesting issues: if most of its
emission is comprised of a single polarization mode, the full traverse exceeds
180\degr; or if both polarization modes are present, then the leading and the
trailing halves of the profiles exhibit two different modes. In either case the
rotating vector model fails to fit the polarization-angle traverse of the core
component.


title:
Joint Receiver and Transmitter Optimization for Energy-Efficient CDMA
  Communications

abstract:
  This paper focuses on the cross-layer issue of joint multiuser detection and
resource allocation for energy efficiency in wireless CDMA networks. In
particular, assuming that a linear multiuser detector is adopted in the uplink
receiver, the case considered is that in which each terminal is allowed to vary
its transmit power, spreading code, and uplink receiver in order to maximize
its own utility, which is defined as the ratio of data throughput to transmit
power. Resorting to a game-theoretic formulation, a non-cooperative game for
utility maximization is formulated, and it is proved that a unique Nash
equilibrium exists, which, under certain conditions, is also Pareto-optimal.
Theoretical results concerning the relationship between the problems of SINR
maximization and MSE minimization are given, and, resorting to the tools of
large system analysis, a new distributed power control algorithm is
implemented, based on very little prior information about the user of interest.
The utility profile achieved by the active users in a large CDMA system is also
computed, and, moreover, the centralized socially optimum solution is analyzed.
Considerations on the extension of the proposed framework to a multi-cell
scenario are also briefly detailed. Simulation results confirm that the
proposed non-cooperative game largely outperforms competing alternatives, and
that it exhibits a quite small performance loss with respect to the socially
optimum solution, and only in the case in which the users number exceeds the
processing gain. Finally, results also show an excellent agreement between the
theoretical closed-form formulas based on large system analysis and the outcome
of numerical experiments.


title: Spectroscopic study of pulsations in the atmosphere of roAp star 10 Aql

abstract:
  We present the analysis of spectroscopic time-series observations of the roAp
star 10 Aql. Observations were carried out in July 2006 with the UVES and SARG
spectrographs simultaneously with the MOST mini-satellite photometry. All these
data were analysed for radial velocity (RV) variations. About 150 lines out of
the 1000 measured reveal clear pulsation signal. Frequency analysis of the
spectroscopic data gives four frequencies. Three highest amplitude frequencies
in spectroscopy coincide with the photometric ones. Phase-amplitude diagrams
created for the lines of different elements/ions show that atmospheric
pulsations may be represented by a superposition of the standing and running
wave components, similar to other roAp stars. The highest RV amplitudes,
300-400 m/s, were measured for Ce II, Dy III, Tb III, and two unidentified
lines at lambda 5471, 5556 A. We discovered ~0.4 period phase jump in the RV
measurements across the Nd III line profiles. It indicates the presence of the
pulsation node in stellar atmosphere. The phase jump occurs at nearly the same
atmospheric layers for the two main frequencies. There is no rotational
modulation in the average spectra for the 6 different nights we analysed.


title: Dirac Neutrino Masses from Generalized Supersymmetry Breaking

abstract:
  We demonstrate that Dirac neutrino masses in the experimentally preferred
range are generated within supersymmetric gauge extensions of the Standard
Model with a generalized supersymmetry breaking sector. If the usual
superpotential Yukawa couplings are forbidden by the additional gauge symmetry
(such as a U(1)'), effective Dirac mass terms involving the "wrong Higgs" field
can arise either at tree level due to hard supersymmetry breaking fermion
Yukawa couplings, or at one-loop due to nonanalytic or "nonholomorphic" soft
supersymmetry breaking trilinear scalar couplings. As both of these operators
are naturally suppressed in generic models of supersymmetry breaking, the
resulting neutrino masses are naturally in the sub-eV range. The neutrino
magnetic and electric dipole moments resulting from the radiative mechanism
also vanish at one-loop order.


title: Stochastic adaptation of importance sampler

abstract:
  Improving efficiency of importance sampler is at the center of research in
Monte Carlo methods. While adaptive approach is usually difficult within the
Markov Chain Monte Carlo framework, the counterpart in importance sampling can
be justified and validated easily. We propose an iterative adaptation method
for learning the proposal distribution of an importance sampler based on
stochastic approximation. The stochastic approximation method can recruit
general iterative optimization techniques like the minorization-maximization
algorithm. The effectiveness of the approach in optimizing the Kullback
divergence between the proposal distribution and the target is demonstrated
using several simple examples.


title:
An Hilbert space approach for a class of arbitrage free implied
  volatilities models

abstract:
  We present an Hilbert space formulation for a set of implied volatility
models introduced in \cite{BraceGoldys01} in which the authors studied
conditions for a family of European call options, varying the maturing time and
the strike price $T$ an $K$, to be arbitrage free. The arbitrage free
conditions give a system of stochastic PDEs for the evolution of the implied
volatility surface ${\hat\sigma}_t(T,K)$. We will focus on the family obtained
fixing a strike $K$ and varying $T$. In order to give conditions to prove an
existence-and-uniqueness result for the solution of the system it is here
expressed in terms of the square root of the forward implied volatility and
rewritten in an Hilbert space setting. The existence and the uniqueness for the
(arbitrage free) evolution of the forward implied volatility, and then of the
the implied volatility, among a class of models, are proved. Specific examples
are also given.


title: The mean field Ising model trough interpolating techniques

abstract:
  Aim of this work is not trying to explore a macroscopic behavior of some
recent model in statistical mechanics but showing how some recent techniques
developed within the framework of spin glasses do work on simpler model,
focusing on the method and not on the analyzed system. To fulfil our will the
candidate model turns out to be the paradigmatic mean field Ising model. The
model is introduced and investigated with the interpolation techniques. We show
the existence of the thermodynamic limit, bounds for the free energy density,
the explicit expression for the free energy with its suitable expansion via the
order parameter, the self-consistency relation, the phase transition, the
critical behavior and the self-averaging properties. At the end a bridge to a
Parisi-like theory is tried and discussed.


title: Sequential operators in computability logic

abstract:
  Computability logic (CL) (see http://www.cis.upenn.edu/~giorgi/cl.html) is a
semantical platform and research program for redeveloping logic as a formal
theory of computability, as opposed to the formal theory of truth which it has
more traditionally been. Formulas in CL stand for (interactive) computational
problems, understood as games between a machine and its environment; logical
operators represent operations on such entities; and "truth" is understood as
existence of an effective solution, i.e., of an algorithmic winning strategy.
  The formalism of CL is open-ended, and may undergo series of extensions as
the study of the subject advances. The main groups of operators on which CL has
been focused so far are the parallel, choice, branching, and blind operators.
The present paper introduces a new important group of operators, called
sequential. The latter come in the form of sequential conjunction and
disjunction, sequential quantifiers, and sequential recurrences. As the name
may suggest, the algorithmic intuitions associated with this group are those of
sequential computations, as opposed to the intuitions of parallel computations
associated with the parallel group of operations: playing a sequential
combination of games means playing its components in a sequential fashion, one
after one.
  The main technical result of the present paper is a sound and complete
axiomatization of the propositional fragment of computability logic whose
vocabulary, together with negation, includes all three -- parallel, choice and
sequential -- sorts of conjunction and disjunction. An extension of this result
to the first-order level is also outlined.


title: Zeta Function Methods and Quantum Fluctuations

abstract:
  A review of some recent advances in zeta function techniques is given, in
problems of pure mathematical nature but also as applied to the computation of
quantum vacuum fluctuations in different field theories, and specially with a
view to cosmological applications.


title: Dynamical Casimir Effect with Semi-Transparent Mirrors, and Cosmology

abstract:
  After reviewing some essential features of the Casimir effect and,
specifically, of its regularization by zeta function and Hadamard methods, we
consider the dynamical Casimir effect (or Fulling-Davis theory), where related
regularization problems appear, with a view to an experimental verification of
this theory. We finish with a discussion of the possible contribution of vacuum
fluctuations to dark energy, in a Casimir like fashion, that might involve the
dynamical version.


title: Photometry of GSC 762-110, a new triple-mode radially pulsating star

abstract:
  Stars pulsating in three radial modes are very rare; only three examples are
known in the Galaxy. These stars are very useful since their periods may be
measured very precisely, and this will constrain the global stellar parameters
and the models of the star's interior. The purpose of this paper is to present
a new example of the class of triple-mode radial pulsators. A search for
candidate multi-mode pulsators was carried out in public survey data.
Time-series photometry of one of the candidates, GSC 762-110, was performed.
GSC 762-110 was found to be a triple-mode radial pulsator, with a fundamental
period of 0.1945d and period ratios of 0.7641 and 0.8012. In addition two
non-radial modes were found, for which the amplitude has diminished
considerably over the last few years.


title:
Low- and high-field induced uniform and staggered magnetizations of a
  spin ladder with DM term

abstract:
  Analytic expressions for uniform and staggered magnetizations of a spin
ladder with a staggered Dzyaloshinskii-Moriya interaction along rungs are
obtained in the lowest perturbative orders. The obtained formulas describe
magnetic behavior in two marginal regions related to low ($h\ll h_c$) and high
($h\gg h_s$) magnetic fields.


title: Cavity BPM System Tests for the ILC Spectrometer

abstract:
  The main physics programme of the International Linear Collider (ILC)
requires a measurement of the beam energy at the interaction point with an
accuracy of $10^{-4}$ or better. To achieve this goal a magnetic spectrometer
using high resolution beam position monitors (BPMs) has been proposed. This
paper reports on the cavity BPM system that was deployed to test this proposal.
We demonstrate sub-micron resolution and micron level stability over 20 hours
for a $1\m$ long BPM triplet. We find micron-level stability over 1 hour for 3
BPM stations distributed over a $30\m$ long baseline. The understanding of the
behaviour and response of the BPMs gained from this work has allowed full
spectrometer tests to be carried out.


title:
Cooperation and the Emergence of Role Differentiation in the Dynamics of
  Social Networks

abstract:
  By means of extensive computer simulations, the authors consider the
entangled coevolution of actions and social structure in a new version of a
spatial Prisoner's Dilemma model that naturally gives way to a process of
social differentiation. Diverse social roles emerge from the dynamics of the
system: leaders are individuals getting a large payoff who are imitated by a
considerable fraction of the population, conformists are unsatisfied
cooperative agents that keep cooperating, and exploiters are defectors with a
payoff larger than the average one obtained by cooperators. The dynamics
generate a social network that can have the topology of a small world network.
The network has a strong hierarchical structure in which the leaders play an
essential role in sustaining a highly cooperative stable regime. But
disruptions affecting leaders produce social crises described as dynamical
cascades that propagate through the network.