title: Searching for Cool Core Clusters at High redshift

abstract:
  We investigate the detection of Cool Cores (CCs) in the distant galaxy
cluster population, with the purpose of measuring the CC fraction out to
redshift 0.7 < z < 1.4. Using a sample of nearby clusters spanning a wide range
of morphologies, we define criteria to characterize cool cores, which are
applicable to the high redshift sample. We analyzed azimuthally averaged
surface brightness (SB) profiles using the known scaling relations and fitted
single/double beta models to the data. Additionally, we measured a surface
brightness concentration, c_SB, as the ratio of the peak over the ambient SB.
To verify that this is an unbiased parameter as a function of redshift, we
developed a model independent "cloning" technique to simulate the nearby
clusters as they would appear at the same redshifts and luminosities as those
in the distant sample. A more physical parameterization of CC presence is
obtained by computing the cooling time at a radius of 20 kpc from the cluster
center. The distribution of the SB concentration and the stacked radial
profiles of the low-z sample, combined with published information on the CC
properties of these clusters, show 3 degrees of SB cuspiness: non-CC, moderate
and strong CC. The same analysis applied to the high-z clusters reveals two
regimes: non-CC and moderate CC. The cooling time distribution corroborates
this result by showing a strong negative correlation with c_SB. Our analysis
indicates a significant fraction of distant clusters harboring a moderate CC
out to z=1.4, similar to those found in the local sample. The absence of strong
cooling which we report is likely linked with a higher merger rate expected at
redshift z > 0.7, and should also be related with the shorter age of distant
clusters, implying less time to develop a cool core.


title: Punctuated Chirality

abstract:
  Most biomolecules occur in mirror, or chiral, images of each other. However,
life is homochiral: proteins contain almost exclusively levorotatory (L) amino
acids, while only dextrorotatory (R) sugars appear in RNA and DNA. The
mechanism behind this fundamental asymmetry of life remains an open problem.
Coupling the spatiotemporal evolution of a general autocatalytic polymerization
reaction network to external environmental effects, we show through a detailed
statistical analysis that high intensity and long duration events may drive
achiral initial conditions towards chirality. We argue that life's
homochirality resulted from sequential chiral symmetry breaking triggered by
environmental events, thus extending the theory of punctuated equilibrium to
the prebiotic realm. Applying our arguments to other potentially life-bearing
planetary platforms, we predict that a statistically representative sampling
will be racemic on average.


title: A JSJ splitting for triangulated open 3-manifolds

abstract:
  We give a sufficient condition for an open 3-manifold to admit a
decomposition along properly embedded open annuli and tori, generalizing the
toric splitting of Jaco-Shalen and Johannson.


title: Discrete Riemann surfaces, linear and non-linear

abstract:
  3 pages presentation of the theory of discrete conformal parameterization
using circle patterns or its linearized theory. Principal results and ideas.


title:
Dynamic localization of lattice electrons under time dependent electric
  and magnetic fields

abstract:
  Applying the method of characteristics leads to wavefunctions and dynamic
localization conditions for electrons on the one dimensional lattice under
perpendicular time dependent electric and magnetic fields. Such conditions
proceed again in terms of sums of products of Bessel functions of the first
kind. However, this time one deals with both the number of magnetic flux quanta
times $\pi $ and the quotients between the Bloch frequency and the ones
characterizing competing fields. Tuning the phases of time dependent
modulations leads to interesting frequency mixing effects providing an
appreciable simplification of dynamic localization conditions one looks for.
The understanding is that proceeding in this manner, the time dependent
superposition mentioned above gets reduced effectively to the influence of
individual ac-fields exhibiting mixed frequency quotients. Besides pure field
limits and superpositions between uniform electric and time dependent magnetic
fields, parity and periodicity effects have also been discussed.


title: Generators of Jacobians of Genus Two Curves

abstract:
  We prove that in most cases relevant to cryptography, the Frobenius
endomorphism on the Jacobian of a genus two curve is represented by a diagonal
matrix with respect to an appropriate basis of the subgroup of l-torsion
points. From this fact we get an explicit description of the Weil-pairing on
the subgroup of l-torsion points. Finally, the explicit description of the
Weil-pairing provides us with an efficient, probabilistic algorithm to find
generators of the subgroup of l-torsion points on the Jacobian of a genus two
curve.


title: Optimal design of composite granular protectors

abstract:
  We employ an evolutionary algorithm to investigate the optimal design of
composite protectors using one-dimensional granular chains composed of beads of
various sizes, masses, and stiffnesses. We define a fitness function using the
maximum force transmitted from the protector to a "wall" that represents the
body to be protected and accordingly optimize the {topology} (arrangement),
{size}, and {material} of the chain. We obtain optimally randomized granular
protectors characterized by high-energy equipartition and the transformation of
incident waves into interacting solitary pulses. We consistently observe that
the pulses traveling to the wall combine to form an extended (long-wavelength),
small-amplitude pulse.

categories: cond-mat.mtrl-sci cond-mat.stat-mech nlin.PS physics.comp-ph


title:
The shape of the initial cluster mass function: what it tells us about
  the local star formation efficiency

abstract:
  We explore how the expulsion of gas from star-cluster forming cloud-cores due
to supernova explosions affects the shape of the initial cluster mass function,
that is, the mass function of star clusters when effects of gas expulsion are
over. We demonstrate that if the radii of cluster-forming gas cores are roughly
constant over the core mass range, as supported by observations, then more
massive cores undergo slower gas expulsion. Therefore, for a given star
formation efficiency, more massive cores retain a larger fraction of stars
after gas expulsion. The initial cluster mass function may thus differ from the
core mass function substantially, with the final shape depending on the star
formation efficiency. A mass-independent star formation efficiency of about 20
per cent turns a power-law core mass function into a bell-shaped initial
cluster mass function, while mass-independent efficiencies of order 40 per cent
preserve the shape of the core mass function.


title: Prime numbers of a kind x^2+1

abstract: The number of primes of a kind x^2+1 is infinite.


title: Macdonald polynomials at $t=q^k$

abstract:
  We investigate the homogeneous symmetric Macdonald polynomials
$P_\lambda(\X;q,t)$ for the specialization $t=q^k$. We show an identity relying
the polynomials $P_\lambda(\X;q,q^k)$ and
$P_\lambda(\frac{1-q}{1-q^k}\X;q,q^k)$. As a consequence, we describe an
operator whose eigenvalues characterize the polynomials $P_\lambda(\X;q,q^k)$.


title:
Neutron-proton mass difference in finite nuclei and the Nolen-Schiffer
  anomaly

abstract:
  The neutron-proton mass difference in finite nuclei is studied in the
framework of a medium-modified Skyrme model. The possible interplay between the
effective nucleon mass in finite nuclei and the Nolen-Schiffer anomaly is
discussed. In particular, we find that a correct description of the properties
of mirror nuclei leads to a stringent restriction of possible modifications of
the nucleon's effective mass in nuclei.


title: Comparison Principles for subelliptic equations of Monge-Ampere type

abstract:
  We present two comparison principles for viscosity sub- and supersolutions of
Monge-Ampere-type equations associated to a family of vector fields. In
particular, we obtain the uniqueness of a viscosity solution to the Dirichlet
problem for the equation of prescribed horizontal Gauss curvature in a Carnot
group.


title:
Moat flow in the vicinity of sunspots for various penumbral
  configurations

abstract:
  High-resolution time series of sunspots have been obtained with the Swedish
1m Solar Telescope between 2003 and 2006 at different locations on the solar
disc. Proper motions in seven different active regions have been studied. The
analysis has been done by applying local correlation tracking to every series
of sunspots, each of them more than 40 minutes long. The sunspots' shapes
include a different variety of penumbral configurations. We report on a
systematic behaviour of the large-scale outflows surrounding the sunspots,
commonly known as moat flows, that are essentially present only when preceded
by a penumbra not tangential but perpendicular to the sunspot border. We
present one case for which this rule appears not to be confirmed. We speculate
that the magnetic neutral line, which is located in the vicinity of the
anomalous region, might be responsible for blocking the outflow. These new
results confirm the systematic and strong relation between the moat flows and
the existence of penumbrae. A comparative statistical study between moats and
standard granulation is also performed.


title:
Mean-free path effects in magnetoresistance of ferromagnetic
  nanocontacts

abstract:
  We investigated the mean-free path effects on the magnetoresistance of
ferromagnetic nanocontacts. For most combinations of parameters the
magnetoresistance monotonously decreases with increasing the contact
cross-section. However, for a certain choice of parameters the calculations
show non-monotonous behavior of the magnetoresistance in the region in which
the diameter of the contact becomes comparable with the mean-free path of
electrons. We attribute this effect to different conduction regimes in the
vicinity of the nanocontact: ballistic for electrons of one spin projection,
and simultaneously diffusive for the other. Furthermore, at certain
combinations of spin asymmetries of the bulk mean-free paths in a
heterocontact, the magnetoresistance can be almost constant, or may even grow
as the contact diameter increases. Thus, our calculations suggest a way to
search for combinations of material parameters, for which high
magnetoresistances can be achieved not only at the nanometric size of the
contact, but also at much larger cross-sections of nanocontacts which can be
easier for fabrication with current technologies. The trial calculations of the
magnetoresistance with material parameters close to those for the Mumetal-Ni
heterocontacts agree satisfactorily with the available experimental data.


title:
Aspects of proper differential sequences of ordinary differential
  equations

abstract:
  We define a proper differential sequence of ordinary differential equations
and introduce a method to derive an alternative sequence of integrals for such
a sequence. We describe some general properties which are illustrated by
several examples.


title: Photon and Dilepton Production in Soft Wall AdS/QCD

abstract:
  We consider the Soft-Wall-model of AdS/QCD to calculate photon production in
strongly coupled Quark Gluon Plasma (sQGP). The IR cut-off only affects the
low-frequency-component of the production rate. The full spectral function is
determined numerically and shows remarkable similarity to computations of the
photon production rate in AdS-duals of $\mathcal{N}=2$ theories with massive
flavor. It is further support that Soft-Wall AdS-QCD correctly captures the IR
physics of the chiral perturbation theory regime of QCD. We confirm this by
relating the IR-effects of the massive flavor deformations to the AdS/QCD soft
wall cut-off. The AdS/QCD spectral function is smooth, however, and unlike
massive flavor models shows no spectral peaks.


title: Analytic continuation of eigenvalues of a quartic oscillator

abstract:
  We consider the Schrodinger operator on the real line with even quartic
potential and study analytic continuation of eigenvalues, as functions of the
coefficient of the potential. We prove several properties of this analytic
continuation conjectured by Bender, Wu, Loeffel and Martin. 1. All eigenvalues
are given by branches of two multi-valued analytic functions, one for even
eigenfunctions and one for odd ones. 2. The only singularities of these
multi-valued functions in the complex plane are algebraic ramification points,
and there are only finitely many singularities over each compact subset of the
plane.


title: Anomalous Hall effect in Fe/Cu bilayers

abstract:
  The scaling of anomalous Hall resistivity on the longitudinal resistivity has
been intensively studied in the different magnetic systems, including
multilayers and granular films, to examine which mechanism, skew scattering or
side-jump, dominates. The basis of the scaling law is that both the
resistivities are due to the electron scattering at the imperfections in the
materials. By studying of anomalous Hall effect (AHE) in the simple Fe/Cu
bilayers, we demonstrate that the measured anomalous Hall effect should not
follow the scaling laws derived from skew scattering or side-jump mechanism due
to the short-circuit and shunting effects of the non-magnetic layers.


title:
Lift of Invariant to Non-Invariant Solutions of Complex Monge-Amp\`ere
  Equations

abstract:
  We show how partner symmetries of the elliptic and hyperbolic complex
Monge-Amp\`ere equations (CMA and HCMA) provide a lift of non-invariant
solutions of three- and two-dimensional reduced equations, i.e., a lift of
invariant solutions of the original CMA and HCMA equations, to non-invariant
solutions of the latter four-dimensional equations. The lift is applied to
non-invariant solutions of the two-dimensional Helmholtz equation to yield
non-invariant solutions of CMA, and to non-invariant solutions of
three-dimensional wave equation and three-dimensional hyperbolic Boyer-Finley
equation to yield non-invariant solutions of HCMA. By using these solutions as
metric potentials, it is possible to construct four-dimensional Ricci-flat
metrics of Euclidean and ultra-hyperbolic signatures that have non-zero
curvature tensors and no Killing vectors.


title: Upper Bounds on the Noise Threshold for Fault-tolerant Quantum Computing

abstract:
  We prove new upper bounds on the tolerable level of noise in a quantum
circuit. We consider circuits consisting of unitary k-qubit gates each of whose
input wires is subject to depolarizing noise of strength p, as well as
arbitrary one-qubit gates that are essentially noise-free. We assume that the
output of the circuit is the result of measuring some designated qubit in the
final state. Our main result is that for p>1-\Theta(1/\sqrt{k}), the output of
any such circuit of large enough depth is essentially independent of its input,
thereby making the circuit useless. For the important special case of k=2, our
bound is p>35.7%. Moreover, if the only allowed gate on more than one qubit is
the two-qubit CNOT gate, then our bound becomes 29.3%. These bounds on p are
notably better than previous bounds, yet are incomparable because of the
somewhat different circuit model that we are using. Our main technique is the
use of a Pauli basis decomposition, which we believe should lead to further
progress in deriving such bounds.


title: 3-Way Composition of Weighted Finite-State Transducers

abstract:
  Composition of weighted transducers is a fundamental algorithm used in many
applications, including for computing complex edit-distances between automata,
or string kernels in machine learning, or to combine different components of a
speech recognition, speech synthesis, or information extraction system. We
present a generalization of the composition of weighted transducers, 3-way
composition, which is dramatically faster in practice than the standard
composition algorithm when combining more than two transducers. The worst-case
complexity of our algorithm for composing three transducers $T_1$, $T_2$, and
$T_3$ resulting in $T$, \ignore{depending on the strategy used, is $O(|T|_Q
d(T_1) d(T_3) + |T|_E)$ or $(|T|_Q d(T_2) + |T|_E)$,} is $O(|T|_Q \min(d(T_1)
d(T_3), d(T_2)) + |T|_E)$, where $|\cdot|_Q$ denotes the number of states,
$|\cdot|_E$ the number of transitions, and $d(\cdot)$ the maximum out-degree.
As in regular composition, the use of perfect hashing requires a pre-processing
step with linear-time expected complexity in the size of the input transducers.
In many cases, this approach significantly improves on the complexity of
standard composition. Our algorithm also leads to a dramatically faster
composition in practice. Furthermore, standard composition can be obtained as a
special case of our algorithm. We report the results of several experiments
demonstrating this improvement. These theoretical and empirical improvements
significantly enhance performance in the applications already mentioned.


title: Spin-orbit interaction in Au structures of various dimensionalities

abstract:
  Variation of the geometrical and electronic properties of the gold materials
in different dimensions has been investigated by $ab$
  $initio$ method, taking into account the spin-orbit (SO) interaction. It is
found that SO effects in different dimensional Au materials depend greatly on
fundamental symmetry and dimensionality. For single walled gold nanotubes
(SWGNTs), SO interaction decreases significantly the conducting channel number
of achiral SWGNT (4, 0), and leads to spin splitting at Fermi level of chiral
SWGNT, indicating that quasi-1D SWGNT can be a good candidate for the
spin-electron devices. Furthermore, our results suggest that cage cluster might
be synthesizable experimentally by taking gold tube structure as parent
material.


title:
The study of structure, electronic and optical properties of
  double-walled carbon nanotube bundle under hydrostatic pressure

abstract:
  Combining a classical force field, a tight-binding model, and
first-principles calculations, we have studied structural, electronic, and
optical properties of double-walled carbon nanotube (DWNT) bundles under
hydrostatic pressure. We find that the outer tube acts as a protection shield
for the inner tube and the inner tube increases the structure stability and the
ability to resist the pressure of the outer tube. Moreover, the collapsed
structures of the double-walled carbon nanotube bundle called ``parallel'' and
``in-between'' are more stable than the one called ``herringbone''. The
structural phase transition induces a pseudogap along symmetry line
\textit{$\Gamma $X}. Furthermore, the optical properties change greatly after
the collapse and a strong anisotropy appears in the collapsed structure. This
provides an efficient experimental way to detect structural phase transitions
in DWNT bundles.


title: On the Ruelle eigenvalue sequence

abstract:
  For certain real analytic data, we show that the eigenvalue sequence of the
associated transfer operator L is insensitive to the holomorphic function space
on which L acts. Explicit bounds on this eigenvalue sequence are established.


title: Fully-connected network of superconducting qubits in a cavity

abstract:
  A fully-connected qubit network is considered, where every qubit interacts
with every other one. When the interactions between the qubits are homogeneous,
the system is a special case of the finite Lipkin-Meshkov-Glick model. We
propose a natural implementation of this model using superconducting qubits in
state-of-the-art circuit QED. The ground state, the low-lying energy spectrum
and the dynamical evolution are investigated. We find that, under realistic
conditions, highly entangled states of Greenberger-Horne-Zeilinger and W types
can be generated. We also comment on the influence of disorder on the system
and discuss the possibility of simulating complex quantum systems, such as
Sherrington-Kirkpatrick spin glasses, with superconducting qubit networks.


title: Dynamical QCD simulation with theta terms

abstract:
  The theta term that breaks the Strong CP symmetry is introduced in the two
flavors of dynamical QCD simulation. theta is analytically continued to a pure
imaginary number to make the probability of Monte Carlo positive. The Neutron's
Electric Dipole Moment (NEDM) is measured on the ensemble under a uniform and
week electric field. Other applications of theta terms are also discussed.


title: Error-Correcting Data Structures

abstract:
  We study data structures in the presence of adversarial noise. We want to
encode a given object in a succinct data structure that enables us to
efficiently answer specific queries about the object, even if the data
structure has been corrupted by a constant fraction of errors. This new model
is the common generalization of (static) data structures and locally decodable
error-correcting codes. The main issue is the tradeoff between the space used
by the data structure and the time (number of probes) needed to answer a query
about the encoded object. We prove a number of upper and lower bounds on
various natural error-correcting data structure problems. In particular, we
show that the optimal length of error-correcting data structures for the
Membership problem (where we want to store subsets of size s from a universe of
size n) is closely related to the optimal length of locally decodable codes for
s-bit strings.


title: Low-momentum interactions in three- and four-nucleon scattering

abstract:
  Low momentum two-nucleon interactions obtained with the renormalization group
method and the similarity renormalization group method are used to study the
cutoff dependence of low energy 3N and 4N scattering observables. The residual
cutoff dependence arises from omitted short-ranged 3N (and higher) forces that
are induced by the renormalization group transformations, and may help to
estimate the sensitivity of various 3N and 4N scattering observables to
short-ranged many-body forces.


title: Morphisms of Cartan connections

abstract:
  We define what we call morphisms of Cartan connections. We generalize the
main theorems on Cartan connections to theorems on morphisms. Many of the known
constructions involving Cartan connections turn out to be examples of
morphisms. We prove some basic results concerning completeness of Cartan
connections. We provide a new method to prove completeness of Cartan
connections using families of morphisms.


title: Omega meson production in pp collisions with a polarized beam

abstract:
  Model independent formulae are derived for the beam analyzing power $A_y$ and
beam to meson spin transfers in $pp \to pp \omega$ taking into consideration
all the six threshold partial wave amplitudes covering the $Ss, Sp$ and $Ps$
channels. Attention is also focussed on the empirical determination of the
lowest three partial wave amplitudes $f_1, f_2, f_3$ without any discrete
ambiguities.


title:
Robust and Efficient Quantum Repeaters with Atomic Ensembles and Linear
  Optics

abstract:
  In the last few years there has been a lot of interest in quantum repeater
protocols using only atomic ensembles and linear optics. Here we show that the
local generation of high-fidelity entangled pairs of atomic excitations, in
combination with the use of two-photon detections for long-distance
entanglement generation, permits the implementation of a very attractive
quantum repeater protocol. Such a repeater is robust with respect to phase
fluctuations in the transmission channels, and at the same time achieves higher
entanglement generation rates than other protocols using the same ingredients.
We propose an efficient method of generating high-fidelity entangled pairs
locally, based on the partial readout of the ensemble-based memories. We also
discuss the experimental implementation of the proposed protocol.


title:
Simulation of majority rule disturbed by power-law noise on directed and
  undirected Barabasi-Albert networks

abstract:
  On directed and undirected Barabasi-Albert networks the Ising model with spin
S=1/2 in the presence of a kind of noise is now studied through Monte Carlo
simulations. The noise spectrum P(n) follows a power law, where P(n) is the
probability of flipping randomly select n spins at each time step. The noise
spectrum P(n) is introduced to mimic the self-organized criticality as a model
influence of a complex environment. In this model, different from the square
lattice, the order-disorder phase transition of the order parameter is not
observed. For directed Barabasi-Albert networks the magnetisation tends to zero
exponentially and for undirected Barabasi-Albert networks, it remains constant.


title: Spectral Properties of Matrices Associated with Some Directed Graphs

abstract:
  We study the spectral properties of certain non-self-adjoint matrices
associated with large directed graphs. Asymptotically the eigenvalues converge
to certain curves, apart from a finite number that have limits not on these
curves.


title: Laws of large numbers for epidemic models with countably many types

abstract:
  In modeling parasitic diseases, it is natural to distinguish hosts according
to the number of parasites that they carry, leading to a countably infinite
type space. Proving the analogue of the deterministic equations, used in models
with finitely many types as a "law of large numbers" approximation to the
underlying stochastic model, has previously either been done case by case,
using some special structure, or else not attempted. In this paper we prove a
general theorem of this sort, and complement it with a rate of convergence in
the $\ell_1$-norm.


title:
Density-constrained time-dependent Hartree-Fock calculation of
  $^{16}$O+$^{208}$Pb fusion cross sections

abstract:
  We present a fully microscopic study of the $^{16}$O+$^{208}$Pb fusion using
the density-constrained time-dependent Hartree-Fock theory. The calculated
fusion cross-sections are in good agreement with the experimental data for the
entire energy range indicating that the incorporation of dynamical effects is
crucial in describing heavy-ion fusion.


title: A plastic flow theory for amorphous materials

abstract:
  Starting from known kinematic picture for plasticity, we derive a set of
dynamical equations describing plastic flow in a Lagrangian formulation. Our
derivation is a natural and a straightforward extension of simple fluids,
elastic and viscous solids theories. These equations contain the Maxwell model
as a special limit. We discuss some results of plasticity which can be
described by this set of equations. We exploit the model equations for the
simple examples: straining of a slab and a rod. We find that necking manifests
always itself (not as a result of instability), except if the very special
constant-velocity stretching process is imposed.


title:
Identifying neutrino mass hierarchy at extremely small theta(13) through
  Earth matter effects in a supernova signal

abstract:
  Collective neutrino flavor transformations deep inside a supernova are
sensitive to the neutrino mass hierarchy even at extremely small values of
theta(13). Exploiting this effect, we show that comparison of the antineutrino
signals from a galactic supernova in two megaton class water Cherenkov
detectors, one of which is shadowed by the Earth, will enable us to distinguish
between the hierarchies if sin^2 theta(13) < 10^{-5}. On the other hand, the
observation of Earth effects in the inverted hierarchy for sin^2 theta(13) >
10^{-3} will provide a robust observable signature of collective oscillations
occurring deep inside the supernova.


title:
Single Slepton Production in association with a single Top Quark at the
  Tevatron and LHC

abstract:
  We calculate the total cross section for single charged slepton production in
association with a top quark at hadron colliders in the baryon triality (B$_3$)
supersymmetric model. We compute event rates for the Tevatron and LHC. We study
the signatures for different supersymmetric scenarios including neutralino and
stau LSPs. We perform a detailed analysis with basic cuts for the B$_3$
operator $\lam^\prime_{231}$ using Monte Carlo simulations to show that the
signal can be distinguished from the background at the LHC. In particular we
employ the resulting lepton charge asymmetry.


title: Accurate eigenvalues of bounded oscillators

abstract:
  We calculate accurate eigenvalues of a bounded oscillator by means of the
Riccati--Pad\'e method that is based on a rational approximation to a
regularized logarithmic derivative of the wavefunction. Sequences of roots of
Hankel determinants approach the model eigenvalues from below with remarkable
convergence rate.


title:
Lifting KK-elements, asymptotical unitary equivalence and classification
  of simple C*-algebras

abstract:
  Let $A$ and $C$ be two unital simple C*-algebas with tracial rank zero.
Suppose that $C$ is amenable and satisfies the Universal Coefficient Theorem.
Denote by ${{KK}}_e(C,A)^{++}$ the set of those $\kappa$ for which
$\kappa(K_0(C)_+\setminus\{0\})\subset K_0(A)_+\setminus\{0\}$ and
$\kappa([1_C])=[1_A]$. Suppose that $\kappa\in {KK}_e(C,A)^{++}.$
  We show that there is a unital monomorphism $\phi: C\to A$ such that
$[\phi]=\kappa.$ Suppose that $C$ is a unital AH-algebra and $\lambda:
\mathrm{T}(A)\to \mathrm{T}_{\mathtt{f}}(C)$ is a continuous affine map for
which $\tau(\kappa([p]))=\lambda(\tau)(p)$ for all projections $p$ in all
matrix algebras of $C$ and any $\tau\in \mathrm{T}(A),$ where $\mathrm{T}(A)$
is the simplex of tracial states of $A$ and $\mathrm{T}_{\mathtt{f}}(C)$ is the
convex set of faithful tracial states of $C.$ We prove that there is a unital
monomorphism $\phi: C\to A$ such that $\phi$ induces both $\kappa$ and
$\lambda.$
  Suppose that $h: C\to A$ is a unital monomorphism and $\gamma \in
\mathrm{Hom}(\Kone(C), \aff(A)).$ We show that there exists a unital
monomorphism $\phi: C\to A$ such that $[\phi]=[h]$ in ${KK}(C,A),$ $\tau\circ
\phi=\tau\circ h$ for all tracial states $\tau$ and the associated rotation map
can be given by $\gamma.$ Applications to classification of simple C*-algebras
are also given.


title: Fitting orbits to tidal streams

abstract:
  Recent years have seen the discovery of many tidal streams through the
Galaxy. Relatively straightforward observations of a stream allow one to deduce
three phase-space coordinates of an orbit. An algorithm is presented that
reconstructs the missing phase-space coordinates from these data. The
reconstruction starts from assumed values of the Galactic potential and a
distance to one point on the orbit, but with noise-free data the condition that
energy be conserved on the orbit enables one to reject incorrect assumptions.
The performance of the algorithm is investigated when errors are added to the
input data that are comparable to those in published data for the streams of
Pal 5. It is found that the algorithm returns distances and proper motions that
are accurate to of order one percent, and enables one to reject quite
reasonable but incorrect trial potentials. In practical applications it will be
important to minimize errors in the input data, and there is considerable scope
for doing this.


title:
Neural network predictions for Z' boson within LEP2 data set of Bhabha
  process

abstract:
  The neural network approach is applied to search for the Z'-boson within the
LEP2 data set for e+ e- -> e+ e- scattering process. In the course of the
analysis, the data set is reduced by 20 percent. The axial-vector and vector
couplings of the Z' are estimated at 95 percent CL within a two-parameter fit.
The mass is determined to be 0.53-1.05 TeV. Comparisons with other results are
given.


title:
Sunyer-i-Balaguer's Almost Elliptic Functions and Yosida's Normal
  Functions

abstract:
  We study the properties of two classes of meromorphic functions in the
complex plane. The first one is the class of almost elliptic functions in the
sense of Sunyer-i-Balaguer. This is the class of meromorphic functions f such
that the family of shifts f(z+h) (h are complex numbers) is normal with respect
to the uniform convergence in the whole complex plane. Given two sequences of
complex numbers, we provide sufficient conditions for them to be zeros and
poles of some almost elliptic function. These conditions enable one to give
(for the first time) explicit non-trivial examples of almost elliptic
functions.
  The second class was introduced by K.Yosida, who called it a class of normal
functions of the first category. This is the class of meromorphic functions f
such that the family of shifts f(z+h)is normal with respect to the uniform
convergence on compacta in the complex plane and no limit point of the family
is a constant function. We give necessary and sufficient conditions for two
sequences of complex numbers to be zeros and poles of some normal function of
the first category and obtain a parametric representation for this class in
terms of zeros and poles.


title: Cops or robbers - a bistable society

abstract:
  The norm game described by Axelrod in 1985 was recently treated with the
master equation formalism. Here we discuss the equations, where {\it i)} those
who break the norm cannot punish and those who punish cannot break the norm,
{\it ii)} the tendency to punish is suppressed if the majority breaks the norm.
The second mechanism is new. For some values of the parameters the solution
shows the saddle-point bifurcation. Then, two stable solutions are possible,
where the majority breaks the norm or the majority punishes. This means, that
the norm breaking can be discontinuous, when measured in the social scale. The
bistable character is reproduced also with new computer simulations on the
Erd{\H o}s--R\'enyi directed network.


title:
Parameter Degeneracy in Flavor-Dependent Reconstruction of Supernova
  Neutrino Fluxes

abstract:
  We reexamine the possibility of reconstructing the initial fluxes of
supernova neutrinos emitted in a future core-collapse galactic supernova
explosion and detected in a Megaton-sized water Cherenkov detector. A novel key
element in our method is the inclusion, in addition to the total and the
average energies of each neutrino species, of a "pinching" parameter
characterizing the width of the distribution as a fit parameter. We uncover in
this case a continuous degeneracy in the reconstructed parameters of supernova
neutrino fluxes at the neutrinosphere. We analyze in detail the features of
this degeneracy and show how it occurs irrespective of the parametrization used
for the distribution function. Given that this degeneracy is real we briefly
comment on possible steps towards resolving it, which necessarily requires
going beyond the setting presented here.


title: Closed k-strings in SU(N) gauge theories : 2+1 dimensions

abstract:
  We calculate the ground state energies of closed k-strings in
(2+1)-dimensional SU(N) gauge theories, for N=4,5,6,8 and k=2,3,4. From the
dependence of the ground state energy on the string length, we infer that such
k-strings are described by an effective string theory that is in the same
bosonic universality class (Nambu-Goto) as the fundamental string. When we
compare the continuum k-string tensions to the corresponding fundamental string
tensions, we find that the ratios are close to, but typically 1-2 percent
above, the Casimir scaling values favoured by some theoretical approaches.
Fitting the N-dependence in a model-independent way favours an expansion in 1/N
(as in Casimir scaling) rather than the 1/N^2 that is suggested by naive colour
counting. We also observe that the low-lying spectrum of k-string states falls
into sectors that belong to particular irreducible representations of SU(N),
demonstrating that the dynamics of string binding knows about the full gauge
group and not just about its centre.


title: On operator fields in the bundle of Dirac spinors

abstract:
  Operator fields in the bundle of Dirac spinors and their conversion to
spatial fields are considered. Some commutator equations are studied with the
use of the conversion technique.


title: Entanglement and Quantum Groups

abstract:
  We describe quantum mechanical entanglement in terms of compact quantum
groups. We prove an analog of positivity of partial transpose (PPT) criterion
and formulate a Horodecki-type Theorem.


title: Enhanced reaction kinetics in biological cells

abstract:
  The cell cytoskeleton is a striking example of "active" medium driven
out-of-equilibrium by ATP hydrolysis. Such activity has been shown recently to
have a spectacular impact on the mechanical and rheological properties of the
cellular medium, as well as on its transport properties : a generic tracer
particle freely diffuses as in a standard equilibrium medium, but also
intermittently binds with random interaction times to motor proteins, which
perform active ballistic excursions along cytoskeletal filaments. Here, we
propose for the first time an analytical model of transport limited reactions
in active media, and show quantitatively how active transport can enhance
reactivity for large enough tracers like vesicles. We derive analytically the
average interaction time with motor proteins which optimizes the reaction rate,
and reveal remarkable universal features of the optimal configuration. We
discuss why active transport may be beneficial in various biological examples:
cell cytoskeleton, membranes and lamellipodia, and tubular structures like
axons.


title: Repulsive, nonmonotonic Casimir forces in a glide-symmetric geometry

abstract:
  We describe a three-dimensional geometry that exhibits a repulsive Casimir
force using ordinary metallic materials, as computed via an exact numerical
method (no uncontrolled approximations). The geometry consists of a zippelike,
glide-symmetric structure formed of interleaved metal brackets attached to
parallel plates. Depending on the separation, the perpendicular force between
the plates/brackets varies from attractive (large separations) to repulsive
(intermediate distances) and back to attractive (close separations), with one
point of stable equilibrium in the perpendicular direction. This geometry was
motivated by a simple intuition of attractive interactions between surfaces,
and so we also consider how a rough proximity force approximation of pairwise
attractions compares to the exact calculations.


title:
A characterisation of the Z^n + Z(\delta) lattice and definite
  nonunimodular intersection forms

abstract:
  We prove a generalisation of Elkies' theorem to nonunimodular definite forms
(and lattices). Combined with inequalities of Froyshov and of Ozsvath and
Szabo, this gives a simple test of whether a rational homology 3-sphere may
bound a definite four-manifold. As an example we show that small positive
surgeries on torus knots do not bound negative-definite four-manifolds.


title: Lie-like Algebras (Superalgeras)

abstract:
  We introduce the notion of a Lie-like algebra$^{\diamond}$
(superalgebra$^{\diamond}$) for $\diamond\in\{^{1-st}, ^{2-nd}, ^{3-rd} \}$.


title: Helicoid-Like Minimal Disks and Uniqueness

abstract:
  We show that an embedded minimal disk in R^3 with large curvature is
bilipschitz with a piece of a helicoid. Additionally, a simplified proof of the
uniqueness of the helicoid is provided.


title: Selective Mott transition and heavy fermions

abstract:
  Starting with an extended version of the Anderson lattice where the
f-electrons are allowed a weak dispersion, we examine the possibility of a Mott
localization of the f-electrons, for a finite value of the hybridization $V$.
We study the fluctuations at the quantum critical point (QCP) where the
f-electrons localize. We find they are in the same universality class as for
the Kondo breakdown QCP, with the following notable features.
  The quantum critical regime sees the appearance of an additional energy scale
separating two universality classes. In the low energy regime, the fluctuations
are dominated by massless gauge modes, while in the intermediate energy regime,
the fluctuations of the modulus of the order parameter are the most relevant
ones. In the latter regime, electric transport simplifies drastically, leading
to a quasi-linear resistivity in 3D and anomalous exponents lower than T in 2
D. This rather unique feature of the quantum critical regime enables us to make
experimentally testable predictions.


title:
First order phase transition in Ising model on two connected
  Barabasi-Albert networks

abstract:
  We investigate the behavior of the Ising model on two connected
Barabasi-Albert scale-free networks. We extend previous analysis and show that
a first order temperature-driven phase transition occurs in such system. The
transition between antiparalelly ordered networks to paralelly ordered networks
is shown to be discontinuous. We calculate the critical temperature. We confirm
the calculations with numeric simulations using Monte-Carlo methods.


title:
Effects of time dependency and efficiency on information flow in
  financial markets

abstract:
  We investigated financial market data to determine which factors affect
information flow between stocks. Two factors, the time dependency and the
degree of efficiency, were considered in the analysis of Korean, the Japanese,
the Taiwanese, the Canadian, and US market data. We found that the frequency of
the significant information decreases as the time interval increases. However,
no significant information flow was observed in the time series from which the
temporal time correlation was removed. These results indicated that the
information flow between stocks evidences time-dependency properties.
Furthermore, we discovered that the difference in the degree of efficiency
performs a crucial function in determining the direction of the significant
information flow.


title:
The long-period Galactic Cepheid RS Puppis - I. A geometric distance
  from its light echoes

abstract:
  Context: The bright southern Cepheid RS Pup is surrounded by a circumstellar
nebula reflecting the light from the central star. The propagation of the light
variations from the Cepheid inside the dusty nebula creates spectacular light
echoes that can be observed up to large distances from the star itself. This
phenomenon is currently unique in this class of stars. Aims: For this
relatively distant star, the trigonometric parallax available from Hipparcos
has a low accuracy. A careful observation of the light echoes has the potential
to provide a very accurate, geometric distance to RS Pup. Methods: We obtained
a series of CCD images of RS Pup with the NTT/EMMI instrument, covering the
variation period of the star (P=41.4d). This allowed us to track the
progression of the light wavefronts over the nebular features surrounding the
star. We measured precisely the phase lag of the photometric variation in
several regions of the circumstellar nebula. Results: From our phase lag
measurements, we derived a geometric distance of 1992 +/- 28 pc to RS Pup. This
distance is affected by a total uncertainty of 1.4%, and corresponds to a
parallax of pi = 0.502 +/- 0.007 mas and a distance modulus of mu = 11.50 +/-
0.03. Conclusions: The geometric distance we derived is by far the most
accurate to a Cepheid, and among the most accurate to any star. RS Pup appears
both as somewhat neglected and particularly promising to investigate the
mass-loss history of Cepheids. Thanks to its highly accurate distance, it is
also bound to become an important luminosity fiducial for the long period part
of the period-luminosity diagram.


title: Frictionless bead packs have macroscopic friction, but no dilatancy

abstract:
  The statement of the title is shown by numerical simulation of homogeneously
sheared packings of frictionless, nearly rigid beads in the quasistatic limit.
Results coincide for steady ﬂows at constant shear rate γ in the
limit of small γ and static approaches, in which packings are equilibrated
under growing deviator stresses. The internal friction angle ϕ, equal to
5.76 $\pm$ 0.22 degrees in simple shear, is independent on the average pressure
P in the rigid limit. It is shown to stem from the ability of stable
frictionless contact networks to form stress-induced anisotropic fabrics. No
enduring strain localization is observed. Dissipation at the macroscopic level
results from repeated network rearrangements, like the eﬀective friction
of a frictionless slider on a bumpy surface. Solid fraction Φ remains
equal to the random close packing value ≃ 0.64 in slowly or statically
sheared systems. Fluctuations of stresses and volume are observed to regress in
the large system limit, and we conclude that the same friction law for simple
shear applies in the large psystem limit if normal stress or density is
externally controlled. Deﬁning the inertia number as I = γ m/(aP),
with m the grain mass and a its diameter, both internal friction
coeﬃcient $\mu$∗ = tan ϕ and volume 1/Φ increase as
powers of I in the quasistatic limit of vanishing I, in which all mechanical
properties are determined by contact network geometry. The microstructure of
the sheared material is characterized with a suitable parametrization of the
fabric tensor and measurements of connectivity and coordination numbers
associated with contacts and near neighbors.


title:
Rotational dynamics of a soft filament: wrapping transition and
  propulsive forces

abstract:
  We analyze experimentally the shape of a long elastic filament rotating in a
viscous liquid. We identify a continuous but sharp transition from a straight
to an helical shape, resulting from the competition between viscous stresses
and elastic forces. This induced helicity generates a propulsive force along
the axis of rotation. In addition, we show that the shape transition is
associated with an unstable branch in the force-torque relation. A linearized
model of the fluid-structure interaction is proposed to account for all the
features of the non-linear filament dynamics.


title:
Thermodynamics and linear response of a Bose-Einstein condensate of
  microcavity polaritons

abstract:
  In this work we derive a theory of polariton condensation based on the theory
of interacting Bose particles. In particular, we describe self-consistently the
linear exciton-photon coupling and the exciton-nonlinearities, by generalizing
the Hartree-Fock-Popov description of BEC to the case of two coupled Bose
fields at thermal equilibrium. In this way, we compute the density-dependent
one-particle spectrum, the energy occupations and the phase diagram. The
results quantitatively agree with the existing experimental findings. We then
present the equations for the linear response of a polariton condensate and we
predict the spectral response of the system to external optical or mechanical
perturbations.


title:
Solution of symmetry equation and hierarchy of self dual Yang-Mills
  systems

abstract:
  The solution of symmetry equation of Yang-Mills self dual system is found in
explicit form of its raising Hamiltonian operator. Thus explicit form of
equations of self dual Yang Mills hierarchy is constructed.


title:
Hyperforests on the Complete Hypergraph by Grassmann Integral
  Representation

abstract:
  We study the generating function of rooted and unrooted hyperforests in a
general complete hypergraph with n vertices by using a novel Grassmann
representation of their generating functions. We show that this new approach
encodes the known results about the exponential generating functions for the
different number of vertices. We consider also some applications as counting
hyperforests in the k-uniform complete hypergraph and the one complete in
hyperedges of all dimensions. Some general feature of the asymptotic regimes
for large number of connected components is discussed.

categories: math-ph cond-mat.stat-mech hep-lat math.CO math.MP


title: Sheared Flow As A Stabilizing Mechanism In Astrophysical Jets

abstract:
  It has been hypothesized that the sustained narrowness observed in the
asymptotic cylindrical region of bipolar outflows from Young Stellar Objects
(YSO) indicates that these jets are magnetically collimated. The j cross B
force observed in z-pinch plasmas is a possible explanation for these
observations. However, z-pinch plasmas are subject to current driven
instabilities (CDI). The interest in using z-pinches for controlled nuclear
fusion has lead to an extensive theory of the stability of magnetically
confined plasmas. Analytical, numerical, and experimental evidence from this
field suggest that sheared flow in magnetized plasmas can reduce the growth
rates of the sausage and kink instabilities. Here we propose the hypothesis
that sheared helical flow can exert a similar stabilizing influence on CDI in
YSO jets.


title:
Next-to-leading order gravitational spin1-spin2 coupling with
  Kaluza-Klein reduction

abstract:
  We use the recently proposed Kaluza-Klein (KK) reduction over the time
dimension, within an effective field theory (EFT) approach, to calculate the
next to leading order (NLO) gravitational spin1-spin2 interaction between two
spinning compact objects. It is shown here that to NLO in the spin1-spin2
interaction, the reduced KK action within the stationary approximation is
sufficient to describe the gravitational interaction, and that it simplifies
calculation substantially. We also find here that the gravito-magnetic vector
field defined within the KK decomposition of the metric mostly dominates the
mediation of the interaction. Our results coincide with those calculated in the
ADM Hamiltonian formalism, and we provide another explanation for the
discrepancy with the result previously derived within the EFT approach, thus
demonstrating clearly the equivalence of the ADM Hamiltonian formalism and the
EFT action approach.


title: The Bousfield lattice for truncated polynomial algebras

abstract:
  The global structure of the unbounded derived category of a truncated
polynomial ring on countably many generators is investigated, via its Bousfield
lattice. The Bousfield lattice is shown to have cardinality larger than that of
the real numbers, and objects with large tensor-nilpotence height are
constructed.


title:
Influence of Low-Degree High-Order p-Mode Splittings on the Solar
  Rotation Profile

abstract:
  The solar rotation profile is well constrained down to about 0.25 R thanks to
the study of acoustic modes. Since the radius of the inner turning point of a
resonant acoustic mode is inversely proportional to the ratio of its frequency
to its degree, only the low-degree p modes reach the core. The higher the order
of these modes, the deeper they penetrate into the Sun and thus they carry more
diagnostic information on the inner regions. Unfortunately, the estimates of
frequency splittings at high frequency from Sun-as-a-star measurements have
higher observational errors due to mode blending, resulting in weaker
constraints on the rotation profile in the inner core. Therefore inversions for
the solar internal rotation use only modes below 2.4 mHz for l < 4. In the work
presented here, we used an 11.5 year-long time series to compute the rotational
frequency splittings for modes l < 4 using velocities measured with the GOLF
instrument. We carried out a theoretical study of the influence of the
low-degree modes in the region 2 to 3.5 mHz on the inferred rotation profile as
a function of their error bars.


title: Calculations for Magnetism in SQUIDs at Millikelvin Temperatures

abstract:
  Here we present details of a calculation that allows us to extract a surface
density of unpaired spins from flux vs. temperature experiments performed on
field-cooled dc Superconducting QUantum Interference Devices (dc SQUIDs).


title: The Order of Phase Transitions in Barrier Crossing

abstract:
  A spatially extended classical system with metastable states subject to weak
spatiotemporal noise can exhibit a transition in its activation behavior when
one or more external parameters are varied. Depending on the potential, the
transition can be first or second-order, but there exists no systematic theory
of the relation between the order of the transition and the shape of the
potential barrier. In this paper, we address that question in detail for a
general class of systems whose order parameter is describable by a classical
field that can vary both in space and time, and whose zero-noise dynamics are
governed by a smooth polynomial potential. We show that a quartic potential
barrier can only have second-order transitions, confirming an earlier
conjecture [1]. We then derive, through a combination of analytical and
numerical arguments, both necessary conditions and sufficient conditions to
have a first-order vs. a second-order transition in noise-induced activation
behavior, for a large class of systems with smooth polynomial potentials of
arbitrary order. We find in particular that the order of the transition is
especially sensitive to the potential behavior near the top of the barrier.


title: Non-universal Interspecific Allometric Scaling of Metabolism

abstract:
  We extend a previously theory for the interspecific allometric scaling
developed in a $d+1$-dimensional space of metabolic states. The time, which is
characteristic of all biological processes, is included as an extra dimension
to $d$ biological lengths. The different metabolic rates, such as basal (BMR)
and maximum (MMR), are described by supposing that the biological lengths and
time are related by different transport processes of energy and mass.
  We consider that the metabolic rates of animals are controlled by three main
transport processes: convection, diffusion and anomalous diffusion. Different
transport mechanisms are related to different metabolic states, with its own
values for allometric exponents. In $d=3$, we obtain that the exponent $b$ of
BMR is $b=0.71$, and that the aerobic sustained MMR upper value of the exponent
is $b=0.86$ (best empirical values for mammals: $b=0.69(2)$ and $b=0.87(3)$).
The 3/4-law appears as an upper limit of BMR. The MMR scaling in different
conditions, other exponents related to BMR and MMR, and the metabolism of
unicellular organisms are also discussed.


title:
Minimal Committee Problem for Inconsistent Systems of Linear
  Inequalities on the Plane

abstract:
  A representation of an arbitrary system of strict linear inequalities in R^n
as a system of points is proposed. The representation is obtained by using a
so-called polarity. Based on this representation an algorithm for constructing
a committee solution of an inconsistent plane system of linear inequalities is
given. A solution of two problems on minimal committee of a plane system is
proposed. The obtained solutions to these problems can be found by means of the
proposed algorithm.


title: Neutrino clustering in growing neutrino quintessence

abstract:
  A growing neutrino mass can stop the dynamical evolution of a dark energy
scalar field, thus explaining the 'why now' problem. We show that such models
lead to a substantial neutrino clustering on the scales of superclusters.
Nonlinear neutrino lumps form at redshift z \sim 1 and could partially drag the
clustering of dark matter. If observed, large scale non-linear structures could
be an indication for a new attractive 'cosmon force' stronger than gravity.


title: On single file and less dense processes

abstract:
  The diffusion process of N hard rods in a 1D interval of length L (--> inf)
is studied using scaling arguments and an asymptotic analysis of the exact
N-particle probability density function (PDF). In the class of such systems,
the universal scaling law of the tagged particle's mean absolute displacement
reads, <|r|>~ <|r|>_{free}/n^mu, where <|r|>_{free} is the result for a free
particle in the studied system and n is the number of particles in the covered
length. The exponent mu is given by, mu=1/(1+a), where a is associated with the
particles' density law of the system, rho~rho_0*L^(-a), 0<= a <=1. The scaling
law for <|r|> leads to, <|r|>~rho_0^((a-1)/2) (<|r| >_{free})^((1+a)/2), an
equation that predicts a smooth interpolation between single file diffusion and
free particle diffusion depending on the particles' density law, and holds for
any underlying dynamics. In particular, <|r|>~t^((1+a)/2) for normal diffusion,
with a Gaussian PDF in space for any value of a (deduced by a complementary
analysis), and, <|r|>~t^((beta(1+a))/2), for anomalous diffusion in which the
system's particles all have the same power-law waiting time PDF for individual
events, psi~t^(-1-beta), 0<beta<1. Our analysis shows that the scaling
<|r|>~t^(1/2) in a 'standard' single file is a direct result of the fixed
particles' density condition imposed on the system, a=0.


title: On the $\ell_1-\ell_q$ Regularized Regression

abstract:
  In this paper we consider the problem of grouped variable selection in
high-dimensional regression using $\ell_1-\ell_q$ regularization ($1\leq q \leq
\infty$), which can be viewed as a natural generalization of the
$\ell_1-\ell_2$ regularization (the group Lasso). The key condition is that the
dimensionality $p_n$ can increase much faster than the sample size $n$, i.e.
$p_n \gg n$ (in our case $p_n$ is the number of groups), but the number of
relevant groups is small. The main conclusion is that many good properties from
$\ell_1-$regularization (Lasso) naturally carry on to the $\ell_1-\ell_q$ cases
($1 \leq q \leq \infty$), even if the number of variables within each group
also increases with the sample size. With fixed design, we show that the whole
family of estimators are both estimation consistent and variable selection
consistent under different conditions. We also show the persistency result with
random design under a much weaker condition. These results provide a unified
treatment for the whole family of estimators ranging from $q=1$ (Lasso) to
$q=\infty$ (iCAP), with $q=2$ (group Lasso)as a special case. When there is no
group structure available, all the analysis reduces to the current results of
the Lasso estimator ($q=1$).


title: Magnetism in SQUIDs at Millikelvin Temperatures

abstract:
  We have characterized the temperature dependence of the flux threading dc
SQUIDs cooled to millikelvin temperatures. The flux increases as 1/T as
temperature is lowered; moreover, the flux change is proportional to the
density of trapped vortices. The data is compatible with the thermal
polarization of surface spins in the trapped fields of the vortices. In the
absence of trapped flux, we observe evidence of spin-glass freezing at low
temperature. These results suggest an explanation for the "universal" 1/f flux
noise in SQUIDs and superconducting qubits.


title:
NLTE determination of the aluminium abundance in a homogeneous sample of
  extremely metal-poor stars

abstract:
  Aims: Aluminium is a key element to constrain the models of the chemical
enrichment and the yields of the first supernovae. But obtaining precise Al
abundances in extremely metal-poor (EMP) stars requires that the non-LTE
effects be carefully taken into account.
  Methods: The NLTE profiles of the blue resonance aluminium lines have been
computed in a sample of 53 extremely metal-poor stars with a modified version
of the program MULTI applied to an atomic model of the Al atom with 78 levels
of Al I and 13 levels of Al II, and compared to the observations.
  Results: With these new determinations, all the stars of the sample show a
ratio Al/Fe close to the solar value: [Al/Fe] =-0.06 +- 0.10 with a very small
scatter. These results are compared to the models of the chemical evolution of
the halo using different models of SN II and are compatible with recent
computations. The sodium-rich giants are not found to be also aluminium-rich
and thus, as expected, the convection in these giants only brings to the
surface the products of the Ne-Na cycle.


title: Toolbox for analyzing finite two-state trajectories

abstract:
  In many experiments, the aim is to deduce an underlying multi-substate on-off
kinetic scheme (KS) from the statistical properties of a two-state trajectory.
However, the mapping of a KS into a two-state trajectory leads to the loss of
information about the KS, and so, in many cases, more than one KS can be
associated with the data. We recently showed that the optimal way to solve this
problem is to use canonical forms of reduced dimensions (RD). RD forms are
on-off networks with connections only between substates of different states,
where the connections can have non-exponential waiting time probability density
functions (WT-PDFs). In theory, only a single RD form can be associated with
the data. To utilize RD forms in the analysis of the data, a RD form should be
associated with the data. Here, we give a toolbox for building a RD form from a
finite two-state trajectory. The methods in the toolbox are based on known
statistical methods in data analysis, combined with statistical methods and
numerical algorithms designed specifically for the current problem. Our toolbox
is self-contained - it builds a mechanism based only on the information it
extracts from the data, and its implementation on the data is fast (analyzing a
10^6 cycle trajectory from a thirty-parameter mechanism takes a couple of hours
on a PC with a 2.66 GHz processor). The toolbox is automated and is freely
available for academic research upon electronic request.


title:
Stochastic Algorithm For Parameter Estimation For Dense Deformable
  Template Mixture Model

abstract:
  Estimating probabilistic deformable template models is a new approach in the
fields of computer vision and probabilistic atlases in computational anatomy. A
first coherent statistical framework modelling the variability as a hidden
random variable has been given by Allassonni\`ere, Amit and Trouv\'e in [1] in
simple and mixture of deformable template models. A consistent stochastic
algorithm has been introduced in [2] to face the problem encountered in [1] for
the convergence of the estimation algorithm for the one component model in the
presence of noise. We propose here to go on in this direction of using some
"SAEM-like" algorithm to approximate the MAP estimator in the general Bayesian
setting of mixture of deformable template model. We also prove the convergence
of this algorithm toward a critical point of the penalised likelihood of the
observations and illustrate this with handwritten digit images.


title:
Nonlinear Saturation of g-modes in Proto-Neutron Stars: Quieting the
  Acoustic Engine

abstract:
  According to Burrows et al.'s acoustic mechanism for core-collapse supernova
explosions, the primary, l=1, g-mode in the core of the proto-neutron star is
excited to an energy of ~ 10^{50} ergs and damps by the emission of sound
waves. Here we calculate the damping of the primary mode by the parametric
instability, i.e., by nonlinear, 3-mode coupling between the low-order primary
mode and pairs of high-order g-modes. We show that the primary mode is strongly
coupled to highly resonant, neutrino damped pairs with n>10; such short
wavelength interactions cannot be resolved in the simulations. We find that the
parametric instability saturates the primary mode energy at ~10^{48} ergs, well
below the energy needed to drive an explosion. We therefore conclude that
acoustic power is unlikely to be energetically significant in core-collapse
supernova explosions.


title: Confronting Lemaitre-Tolman-Bondi models with Observational Cosmology

abstract:
  The possibility that we live in a special place in the universe, close to the
centre of a large void, seems an appealing alternative to the prevailing
interpretation of the acceleration of the universe in terms of a LCDM model
with a dominant dark energy component. In this paper we confront the
asymptotically flat Lemaitre-Tolman-Bondi (LTB) models with a series of
observations, from Type Ia Supernovae to Cosmic Microwave Background and Baryon
Acoustic Oscillations data. We propose two concrete LTB models describing a
local void in which the only arbitrary functions are the radial dependence of
the matter density Omega_M and the Hubble expansion rate H. We find that all
observations can be accommodated within 1 sigma, for our models with 4 or 5
independent parameters. The best fit models have a chi^2 very close to that of
the LCDM model. We perform a simple Bayesian analysis and show that one cannot
exclude the hypothesis that we live within a large local void of an otherwise
Einstein-de Sitter model.


title: Eccentricity of masing disks in Active Galactic Nuclei

abstract:
  Observations of Keplerian disks of masers in NCG 4258 and other Seyfert
galaxies can be used to obtain geometric distance estimates and derive the
Hubble constant. The ultimate precision of such measurements could be limited
by uncertainties in the disk geometry. Using a time-dependent linear theory
model, we study the evolution of a thin initially eccentric disk under
conditions appropriate to sub-pc scales in Active Galactic Nuclei. The
evolution is controlled by a combination of differential precession driven by
the disk potential and propagating eccentricity waves that are damped by
viscosity. A simple estimate yields a circularization timescale of
approximately 10 Myr at 0.1 pc. Numerical solutions for the eccentricity
evolution confirm that damping commences on this timescale, but show that the
subsequent decay rate of the eccentricity depends upon the uncertain strength
of viscous damping of eccentricity. If eccentricity waves are important further
decay of the eccentricity can be slow, with full circularization requiring up
to 50 Myr for disks at radii of 0.1 pc to 0.2 pc. Observationally, this implies
that it is plausible that enough time has elapsed for the eccentricity of
masing disks to have been substantially damped, but that it may not be
justified to assume vanishing eccentricity. We predict that during the damping
phase the pericenter of the eccentric orbits describes a moderately tightly
wound spiral with radius.


title: A model of diffuse Galactic Radio Emission from 10 MHz to 100 GHz

abstract:
  Understanding diffuse Galactic radio emission is interesting both in its own
right and for minimizing foreground contamination of cosmological measurements.
Cosmic Microwave Background experiments have focused on frequencies > 10 GHz,
whereas 21 cm tomography of the high redshift universe will mainly focus on <
0.2 GHz, for which less is currently known about Galactic emission. Motivated
by this, we present a global sky model derived from all publicly available
total power large-area radio surveys, digitized with optical character
recognition when necessary and compiled into a uniform format, as well as the
new Villa Elisa data extending the 1.4 GHz map to the entire sky. We quantify
statistical and systematic uncertainties in these surveys by comparing them
with various global multi-frequency model fits. We find that a principal
component based model with only three components can fit the 11 most accurate
data sets (at 10, 22, 45 & 408 MHz and 1.4, 2.3, 23, 33, 41, 61, 94 GHz) to an
accuracy around 1%-10% depending on frequency and sky region. Both our data
compilation and our software returning a predicted all-sky map at any frequency
from 10 MHz to 100 GHz are publicly available at
http://space.mit.edu/home/angelica/gsm .


title: Do Newton's G and Milgrom's a_0 vary with cosmological epoch ?

abstract:
  In the scalar tensor gravitational theories Newton's constant G_N evolves in
the expanding universe. Likewise, it has been speculated that the acceleration
scale a_0 in Milgrom's modified Newtonian dynamics (MOND) is tied to the scale
of the cosmos, and must thus evolve. With the advent of relativistic
implementations of the modified dynamics, one can address the issue of
variability of the two gravitational ''constants'' with some confidence. Using
TeVeS, the Tensor-Vector-Scalar gravitational theory, as an implementation of
MOND, we calculate the dependence of G_N and a_0 on the TeVeS parameters and
the coeval cosmological value of its scalar field, \phi_c. We find that G_N,
when expressed in atomic units, is strictly nonevolving, a result fully
consistent with recent empirical limits on the variation of G_N. By contrast,
we find that a_0 depends on \phi_c and may thus vary with cosmological epoch.
However, for the brand of TeVeS which seems most promising, a_0 variation
occurs on a timescale much longer than Hubble's, and should be imperceptible
back to redshift unity or even beyond it. This is consistent with emergent data
on the rotation curves of disk galaxies at significants redshifts.


title:
Adiabatic optical entanglement between electron spins in separate
  quantum dots

abstract:
  We present an adiabatic approach to the design of entangling quantum
operations with two electron spins localized in separate InAs/GaAs quantum dots
via the Coulomb interaction between optically-excited localized states.
Slowly-varying optical pulses minimize the pulse noise and the relaxation of
the excited states. An analytic "dressed state" solution gives a clear physical
picture of the entangling process, and a numerical solution is used to
investigate the error dynamics. For two vertically-stacked quantum dots we show
that, for a broad range of dot parameters, a two-spin state with concurrence
$C>0.85$ can be obtained by four optical pulses with durations $\sim 0.1 - 1$
ns.


title:
Bayesian Galaxy Shape Measurement for Weak Lensing Surveys -II.
  Application to Simulations

abstract:
  We extend the Bayesian model fitting shape measurement method presented in
Miller et al. (2007) and use the method to estimate the shear from the Shear
TEsting Programme simulations (STEP). The method uses a fast model fitting
algorithm which uses realistic galaxy profiles and analytically marginalises
over the position and amplitude of the model by doing the model fitting in
Fourier space. This is used to find the full posterior probability in
ellipticity so that the shear can be estimated in a fully Bayesian way. The
Bayesian shear estimation allows measurement bias arising from the presence of
random noise to be removed. In this paper we introduce an iterative algorithm
that can be used to estimate the intrinsic ellipticity prior and show that this
is accurate and stable. By using the method to estimate the shear from the
STEP1 simulations we find the method to have a shear bias of m ~ 0.005 and a
variation in shear offset with PSF type of sigma_c ~ 0.0002. These values are
smaller than for any method presented in the STEP1 publication that behaves
linearly with shear. Using the method to estimate the shear from the STEP2
simulations we find than the shear bias and offset are m ~ 0.002 and c ~
-0.0007 respectively. In addition we find that the bias and offset are stable
to changes in magnitude and size of the galaxies. Such biases should yield any
cosmological constraints from future weak lensing surveys robust to systematic
effects in shape measurement.


title:
Synchrotron Self-Compton Analysis of TeV X-ray Selected BL Lacertae
  Objects

abstract:
  We introduce a methodology for analysis of multiwavelength data from X-ray
selected BL Lac (XBL) objects detected in the TeV regime. By assuming that the
radio--through--X-ray flux from XBLs is nonthermal synchrotron radiation
emitted by isotropically-distributed electrons in the randomly oriented
magnetic field of a relativistic blazar jet, we obtain the electron spectrum.
This spectrum is then used to deduce the synchrotron self-Compton (SSC)
spectrum as a function of the Doppler factor, magnetic field, and variability
timescale. The variability timescale is used to infer the comoving blob radius
from light travel-time arguments, leaving only two parameters. With this
approach, we accurately simulate the synchrotron and SSC spectrum of flaring
XBLs in the Thomson through Klein-Nishina regimes. Photoabsorption by
interactions with internal jet radiation and the intergalactic background light
(IBL) is included. Doppler factors, magnetic fields, and absolute jet powers
are obtained by fitting the {\em HESS} and {\em Swift} data of the recent giant
TeV flare observed from \object{PKS 2155--304}. For the contemporaneous {\em
Swift} and {\em HESS} data from 28 and 30 July 2006, respectively, Doppler
factors $\gtrsim 60$ and absolute jet powers $\gtrsim 10^{46}$ ergs s$^{-1}$
are required for a synchrotron/SSC model to give a good fit to the data, for a
low intensity of the IBL and a ratio of 10 times more energy in hadrons than
nonthermal electrons. Fits are also made to a TeV flare observed in 2001 from
Mkn 421 which require Doppler factors $\gtrsim 30$ and jet powers $\gtrsim
10^{45}$ erg s$^{-1}$.


title:
The inflationary gravitational-wave background and measurements of the
  scalar spectral index

abstract:
  Inflation predicts a stochastic background of gravitational waves over a
broad range of frequencies, from those accessible with cosmic microwave
background (CMB) measurements, to those accessible directly with
gravitational-wave detectors, like NASA's Big-Bang Observer (BBO), currently
under study. In a previous paper [Phys. Rev. D73, 023504 (2006)] we connected
CMB constraints to the amplitude and tensor spectral index of the inflationary
gravitational-wave background (IGWB) at BBO frequencies for four classes of
models of inflation by directly solving the inflationary equations of motion.
Here we extend that analysis by including results obtained in the WMAP
third-year data release as well as by considering two additional classes of
inflationary models. As often noted in the literature, the recent indication
that the primordial density power-spectrum has a red spectral index implies
(with some caveats) that the amplitude of the IGWB may be large enough to be
observable in the CMB polarization. Here we also explore the implications for
the direct detection of the IGWB.


title:
Vacuum Energy, the Cosmological Constant and Compact Extra Dimensions:
  Constraints from Casimir Effect Experiments

abstract:
  We consider a universe with a compact extra dimension and a cosmological
constant emerging from a suitable ultraviolet cutoff on the zero point energy
of the vacuum. We derive the Casimir force between parallel conducting plates
as a function of the following scales: plate separation, radius of the extra
dimension and cutoff energy scale. We find that there are critical values of
these scales where the Casimir force between the plates changes sign. For the
cutoff energy scale required to reproduce the observed value of the
cosmological constant, we find that the Casimir force changes sign and becomes
repulsive for plate separations less than a critical separation $d_0=0.6mm$,
assuming a zero radius of the extra dimension (no extra dimension). This
prediction contradicts Casimir experiments which indicate an attractive force
down to plate separations of $100nm$. For a non-zero extra dimension radius,
the critical separation $d_0$ gets even larger than $0.6mm$ and remains
inconsistent with Casimir force experiments. We conclude that with or without
the presence of a compact extra dimension, vacuum energy with any suitable
cutoff can not play the role of the cosmological constant.


title: Cosmic dynamics in the era of Extremely Large Telescopes

abstract:
  The redshifts of all cosmologically distant sources are expected to
experience a small, systematic drift as a function of time due to the evolution
of the Universe's expansion rate. A measurement of this effect would represent
a direct and entirely model-independent determination of the expansion history
of the Universe over a redshift range that is inaccessible to other methods.
Here we investigate the impact of the next generation of Extremely Large
Telescopes on the feasibility of detecting and characterising the cosmological
redshift drift. We consider the Lyman alpha forest in the redshift range 2 < z
< 5 and other absorption lines in the spectra of high redshift QSOs as the most
suitable targets for a redshift drift experiment. Assuming photon-noise limited
observations and using extensive Monte Carlo simulations we determine the
accuracy to which the redshift drift can be measured from the Ly alpha forest
as a function of signal-to-noise and redshift. Based on this relation and using
the brightness and redshift distributions of known QSOs we find that a 42-m
telescope is capable of unambiguously detecting the redshift drift over a
period of ~20 yr using 4000 h of observing time. Such an experiment would
provide independent evidence for the existence of dark energy without assuming
spatial flatness, using any other cosmological constraints or making any other
astrophysical assumption.


title: Magnetic Fields in the Aftermath of Phase Transitions

abstract:
  The COSLAB effort has focussed on the formation of topological defects during
phase transitions. Yet there is another potentially interesting signature of
cosmological phase transitions, which also deserves study in the lab. This is
the generation of magnetic fields during phase transitions. In particular,
cosmological phase transitions that also lead to preferential production of
matter over antimatter (``baryogenesis''), are expected to produce helical
(left-handed) magnetic fields. The study of analogous processes in the lab can
yield important insight into the production of helical magnetic fields, and the
observation of such fields in the universe can be invaluable for both particle
physics and cosmology.


title: Constructing QCD one-loop amplitudes

abstract:
  In the context of constructing one-loop amplitudes using a unitarity
bootstrap approach we discuss a general systematic procedure for obtaining the
coefficients of the scalar bubble and triangle integral functions of one-loop
amplitudes. Coefficients are extracted after examining the behaviour of the cut
integrand as the unconstrained parameters of a specifically chosen
parametersiation of the cut loop momentum approach infinity.


title: Blueprint for a Classic Proof of the Four Colour Theorem

abstract:
  The proof uses the property that the vertices of a triangulated planar graph
can be four coloured if the triangles can have a +1 or -1 orientation so that
the sum of the triangle orientations around each vertex is a multiple of 3.
Such orientation is first used separately on one of the two triangulated
polygons resulting from a Hamilton circuit in a triangulated planar graph with
v vertices. The graph is then reconstructed by adding the triangles of the
other polygon one by one. When the graph is totally reconstructed there is
always a combination for the orientations of the triangles for which their sum
around each of v-2 successive vertices in the Hamilton circuit is a multiple of
3. It is then provable that the sum of the triangle orientations around the two
remaining vertices must also be a multiple of 3.


title: A Pair Of Quanta Cannot Be Wed

abstract:
  Wooters, Zurek and others have shown that "A Single Quantum Cannot Be
Cloned". The reason is two-fold: 1. A quantum cloner would permit FTL
signaling; 2. A quantum cloner would violate the linearity requirement for
quantum superposition. I present here a similar proof that two arbitrary
quantum states cannot be universally welded together to produce a double
quantum state. In particular, opposite polarization states cannot be perfectly
merged. This paper closes another FTL loophole and discloses a new law of
nature: Perfect quantum weddings are not possible.


title:
Nonthermal Synchrotron and Synchrotron Self-Compton Emission from GRBs:
  Predictions for {\em Swift} and {\em GLAST}

abstract:
  Results of a leptonic jet model for the prompt emission and early afterglows
of GRBs are presented. The synchrotron component is modeled with the canonical
Band spectrum and the synchrotron self-Compton component is calculated from the
implied synchrotron-emitting electron spectrum in a relativistic plasma blob.
In the comoving frame the magnetic field is assumed to be tangled and the
electron and photon distributions are assumed to be isotropic. The
Compton-scattered spectrum is calculated using the full Compton cross-section
in the Thomson through Klein-Nishina using the Jones formula. Pair production
photoabsorption, both from ambient radiation in the jet and from the
extragalactic background light (EBL), is taken into account. Results are
presented as a function of a small set of parameters: the Doppler factor, the
observed variability timescale, the comoving magnetic field, the peak
synchrotron flux, and the redshift of the burst. Model predictions will be
tested by multiwavelength observations, including the {\em Swift} and {\em
GLAST} satellites, which will provide unprecedented coverage of GRBs.


title:
The Intergalactic Propagation of Ultra-High Energy Cosmic Ray Nuclei: An
  Analytic Approach

abstract:
  It is likely that ultra-high energy cosmic rays contain a significant
component of heavy or intermediate mass nuclei. The propagation of ultra-high
energy nuclei through cosmic radiation backgrounds is more complicated than
that of protons and its study has required the use of Monte Carlo techniques.
We present an analytic method for calculating the spectrum and the composition
at Earth of ultra-high energy cosmic rays which start out as heavy nuclei from
their extragalactic sources. The results obtained are in good agreement with
those obtained using numerical methods.


title: Mollifiers in Clifford Analysis

abstract:
  We introduce mollifiers in Clifford analysis setting and construct a sequence
of $\C^{\infinity}$-functions that approximate a $\gamma$-regular function and
a solution to a non homogeneous BVP of an in homogeneous Dirac like operator in
certain Sobolev spaces over bounded domains whose boundary is not that wild.
One can extend the smooth functions upto the boundary if the domain has a
$\C^1$-boundary and this is the case in the paper as we consider a domain whose
boundary is a $\C^2$-hyper surface.


title:
On how to complete the Dynamical Generation of Quark-Level Linear Sigma
  Model like Theories beyond one Loop

abstract:
  A self-consistent strategy is proposed to complete in a renormalization
scheme independent way the dynamical generation of Quark-Level Linear Sigma
Model like Lagrangean theories beyond one loop like the theories of strong and
electroweak interactions. The present discussion refers for simplicity to
scalar and pseudoscalar degrees of freedom only while disregarding yet -
without loss of generality - vector and axial vector degrees of freedom.
Moreover points the discussion to approximations underlying dimensional and
implicit regularization as presently used.


title:
The polydisperse cell model: Non-linear screening and charge
  renormalization in colloidal mixtures

abstract:
  We propose a model for the calculation of renormalized charges and osmotic
properties of mixtures of highly charged colloidal particles. The model is a
generalization of the cell model and the notion of charge renormalization as
introduced by Alexander and his collaborators (J. Chem. Phys. 80, 5776 (1984)).
The total solution is partitioned into as many different cells as components in
the mixture. The radii of these cells are determined self-consistently for a
given set of parameters from the solution of the non-linear Poisson-Boltzmann
equation with appropriate boundary conditions. This generalizes Alexanders's
model where the (unique) Wigner-Seitz cell radius is fixed solely by the
colloids packing fraction. We illustrate the technique by considering a binary
mixture of colloids with the same sign of charge. The present model can be used
to calculate thermodynamic properties of highly charged colloidal mixtures at
the level of linear theories, while taking the effect of non-linear screening
into account.


title: Thermal conduction in molecular chains: Non-Markovian effects

abstract:
  We study the effect of non-Markovian reservoirs on the heat conduction
properties of short to intermediate size molecular chains. Using classical
molecular dynamics simulations, we show that the distance dependence of the
heat current is determined not only by the molecular properties, rather it is
also critically influenced by the spectral properties of the heat baths for
both harmonic and anharmonic molecular chains. For highly correlated reservoirs
the current of an anharmonic chain may exceed the flux of the corresponding
harmonic system. Our numerical results are accompanied by a simple single-mode
heat conduction model that can capture the intricate distance dependence
obtained numerically.


title: Tidal Evolution of Close-in Extra-Solar Planets

abstract:
  The distribution of eccentricities e of extra-solar planets with semi-major
axes a > 0.2 AU is very uniform, and values for e are generally large. For a <
0.2 AU, eccentricities are much smaller (most e < 0.2), a characteristic widely
attributed to damping by tides after the planets formed and the protoplanetary
gas disk dissipated. We have integrated the classical coupled tidal evolution
equations for e and a backward in time over the estimated age of each planet,
and confirmed that the distribution of initial e values of close-in planets
matches that of the general population for reasonable tidal dissipation values
Q, with the best fits for stellar and planetary Q being ~ 10^5.5 and ~ 10^6.5
respectively. The current small values of a were only reached gradually due to
tides over the lifetimes of the planets, i.e., the earlier gas disk migration
did not bring all planets to their current orbits. As the orbits tidally
evolved, there was substantial tidal heating within the planets. The past tidal
heating of each planet may have contributed significantly to the thermal budget
that governed the planet's physical properties, including its radius, which in
many cases may be measured by observing transit events. Here we also compute
the plausible heating histories for a few planets with anomalously large
measured radii, including HD 209458 b. We show that they may have undergone
substantial tidal heating during the past billion years, perhaps enough to
explain their large radii. Theoretical models of exoplanet interiors and the
corresponding radii should include the role of large and time-variable tidal
heating. Our results may have important implications for planet formation
models, physical models of "hot Jupiters", and the success of transit surveys.


title:
Local density of states of 1D Mott insulators and CDW states with a
  boundary

abstract:
  We determine the local density of states (LDOS) of one-dimensional
incommensurate charge density wave (CDW) states in the presence of a strong
impurity potential, which is modeled by a boundary. We find that the CDW gets
pinned at the impurity, which results in a singularity in the Fourier transform
of the LDOS at momentum 2k_F. At energies above the spin gap we observe
dispersing features associated with the spin and charge degrees of freedom
respectively. In the presence of an impurity magnetic field we observe the
formation of a bound state localized at the impurity. All of our results carry
over to the case of one dimensional Mott insulators by exchanging the roles of
spin and charge degrees of freedom. We discuss the implications of our result
for scanning tunneling microscopy experiments on spin-gap systems such as
two-leg ladder cuprates and 1D Mott insulators.


title: Representation theory of Jordanian algebra

abstract:
  We describe the complete set of pairwise non-isomorphic irreducible modules
S(a) over the algebra R given by the defining relation xy-yx=yy, and the rule
how they could be glued to indecomposables. Namely, we show that
Ext_k^1(S(a),S(b))=0, if a not equal to b. Also the set of all representations
is described subject to the Jordan normal form of Y.
  We study then properties of the image algebras in the endomorphism ring.
Among facts we prove is that they are all basic algebras. Along this line we
establish an analogue of the Gerstenhaber-Taussky-Motzkin theorem on the
dimension of algebras generated by two commuting matrices. All image algebras
of indecomposable modules turned out to be local complete algebras. We compare
them with the Ringel's classification by means of finding relations of image
algebras. As a result we derive that all image algebras of n-dimensional
representations with full block Y are tame for n smaller or equal then 4 and
wild for n starting from 5.
  We suggest a stratification of representation space of R related to the
partitions of n defined by the Jordan normal form of Y. We give a complete
classification by parameters for some strata and present examples of tame (up
to automorphisms) strata, while the generic strata is wild.


title: Enhanced Geometry Fluctuations in Minkowski and Black Hole Spacetimes

abstract:
  We will discuss selected physical effects of spacetime geometry fluctuations,
especially the operational signatures of geometry fluctuations and their
effects on black hole horizons. The operational signatures which we discuss
involve the effects of the fluctuations on images, and include luminosity
variations, spectral line broadening and angular blurring. Our main interest
will be in black hole horizon fluctuations, especially horizon fluctuations
which have been enhanced above the vacuum level by gravitons or matter in
squeezed states. We investigate whether these fluctuations can alter the
thermal character of a black hole. We find that this thermal character is
remarkably robust, and that Hawking's original derivation using transplanckian
modes does not seem to be sensitive even to enhanced horizon fluctuations.


title: Study of B-> phi phi K Decays

abstract:
  We report an observation of the decay B^\pm -> \phi \phi K^\pm and evidence
for B^0 -> \phi \phi K^0. These results are based on a 414 fb^{-1} data sample
collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider
operating at the \Upsilon(4S) resonance. The branching fractions for these
decay modes are measured to be Br(B^{\pm} -> \phi \phi K^\pm) =
(3.2^{+0.6}_{-0.5} +- 0.3) * 10^{-6} and Br(B^{0} \to \phi \phi K^{0}) =
(2.3^{+1.0}_{-0.7} +- 0.2) * 10^{-6} for \phi \phi invariant mass below 2.85
GeV/c^2. The corresponding partial rate asymmetry for the charged B mode is
measured to be A_{CP}(B^\pm -> \phi \phi K^\pm) = 0.01^{+0.19}_{-0.16} +- 0.02.
We also study the decays B^\pm -> J/\psi K^\pm and B^\pm -> \eta_c K^\pm, where
the J/\psi and \eta_c decay to final states with four charged kaons. We find
A_{CP}(B^\pm -> \phi \phi K^\pm) with the \phi\phi candidates within the \eta_c
mass region is 0.15^{+0.16}_{-0.17} +- 0.02, consistent with no asymmetry.


title:
Persistence of instanton connections in chemical reactions with time
  dependent rates

abstract:
  The evolution of a system of chemical reactions can be studied, in the
eikonal approximation, by means of a Hamiltonian dynamical system. The fixed
points of this dynamical system represent the different states in which the
chemical system can be found, and the connections among them represent
instantons or optimal paths linking these states. We study the relation between
the phase portrait of the Hamiltonian system representing a set of chemical
reactions with constant rates and the corresponding system when these rates
vary in time. We show that the topology of the phase space is robust for small
time-dependent perturbations in concrete examples and state general results
when possible. This robustness allows us to apply some of the conclusions on
the qualitative behavior of the autonomous system to the time-dependent
situation.


title:
Metric Dependence and Asymptotic Minimization of the Expected Number of
  Critical Points of Random Holomorphic Sections

abstract:
  We prove the main conjecture from [M. R. Douglas, B. Shiffman and S.
Zelditch, Critical points and supersymmetric vacua, II: Asymptotics and
extremal metrics. J. Differential Geom. 72 (2006), no. 3, 381-427] concerning
the metric dependence and asymptotic minimization of the expected number
\mathcal{N}^{crit}_{N,h} of critical points of random holomorphic sections of
the Nth tensor power of a positive line bundle. The first non-topological term
in the asymptotic expansion of \mathcal{N}^{crit}_{N,h} is the the Calabi
functional multiplied by the constant \be_2(m) which depends only on the
dimension of the manifold. We prove that \be_2(m) is strictly positive in all
dimensions, showing that the expansion is non-topological for all m, and that
the Calabi extremal metric, when it exists, asymptotically minimizes
\mathcal{N}^{crit}_{N,h}.


title:
A paradigmatic flow for small-scale magnetohydrodynamics: properties of
  the ideal case and the collision of current sheets

abstract:
  We propose two sets of initial conditions for magnetohydrodynamics (MHD) in
which both the velocity and the magnetic fields have spatial symmetries that
are preserved by the dynamical equations as the system evolves. When
implemented numerically they allow for substantial savings in CPU time and
memory storage requirements for a given resolved scale separation. Basic
properties of these Taylor-Green flows generalized to MHD are given, and the
ideal non-dissipative case is studied up to the equivalent of 2048^3 grid
points for one of these flows. The temporal evolution of the logarithmic
decrements, delta, of the energy spectrum remains exponential at the highest
spatial resolution considered, for which an acceleration is observed briefly
before the grid resolution is reached. Up to the end of the exponential decay
of delta, the behavior is consistent with a regular flow with no appearance of
a singularity. The subsequent short acceleration in the formation of small
magnetic scales can be associated with a near collision of two current sheets
driven together by magnetic pressure. It leads to strong gradients with a fast
rotation of the direction of the magnetic field, a feature also observed in the
solar wind.


title: A nonholonomic Moser theorem and optimal transport

abstract:
  We prove the following nonholonomic version of the classical Moser theorem:
given a bracket-generating distribution on a connected compact manifold
(possibly with boundary), two volume forms of equal total volume can be
isotoped by the flow of a vector field tangent to this distribution. We
describe formal solutions of the corresponding nonholonomic mass transport
problem and present the Hamiltonian framework for both the Otto calculus and
its nonholonomic counterpart as infinite-dimensional Hamiltonian reductions on
diffeomorphism groups.
  Finally, we define a nonholonomic analog of the Wasserstein (or, Kantorovich)
metric on the space of densities and prove that the subriemannian heat equation
defines a gradient flow on the nonholonomic Wasserstein space with the
potential given by the Boltzmann relative entropy functional.


title:
Covariant spectator theory of np scattering: Phase shifts obtained from
  precision fits to data below 350 MeV

abstract:
  Using the covariant spectator theory (CST), we present two one boson exchange
kernels that have been successfully adjusted to fit the 2007 world np data
(containing 3788 data) below 350 MeV. One model (which we designate WJC-1) has
27 parameters and fits with a chi2/N = 1.06. The other model (designated WJC-2)
has only 15 parameters and fits with a chi2/N = 1.12. Both of these models also
reproduce the experimental triton binding energy without introducing additional
irreducible three-nucleon forces. One result of this work is a new phase shift
analysis, updated for all data until 2006, which is useful even if one does not
work within the CST. In carrying out these fits we have reviewed the entire
data base, adding new data not previously used in other high precision fits and
restoring some data omitted in previous fits. A full discussion and evaluation
of the 2007 data base is presented.


title: Detection of supernovae neutrinos with neutrino-iron scattering

abstract:
  The $\nu_e-^{56}$Fe cross section is evaluated in the projected quasiparticle
random phase approximation (PQRPA). This model solves the puzzle observed in
RPA for nuclei with mass around $^{12}$C, because it is the only RPA model that
treats the Pauli principle correctly. The cross sections as a function of the
incident neutrino energy are compared with recent theoretical calculations of
similar models. The average cross section weighted with the flux spectrum
yields a good agreement with the experimental data. The expected number of
events in the detection of supernova neutrinos is calculated for the LVD
detector leading to an upper limit for the electron neutrino energy of
particular importance in this experiment


title: Fast Computation of Partial Fourier Transforms

abstract:
  We introduce two efficient algorithms for computing the partial
  Fourier transforms in one and two dimensions. Our study is motivated by the
wave extrapolation procedure in reflection seismology. In both algorithms, the
main idea is to decompose the summation domain of into simpler components in a
multiscale way. Existing fast algorithms are then applied to each component to
obtain optimal complexity. The algorithm in 1D is exact and takes $O(N\log^2
N)$ steps. Our solution in 2D is an approximate but accurate algorithm that
takes $O(N^2 \log^2 N)$ steps. In both cases, the complexities are almost
linear in terms of the degree of freedom. We provide numerical results on
several test examples.


title: Constructing Linear Codes with Good Joint Spectra

abstract:
  The problem of finding good linear codes for joint source-channel coding
(JSCC) is investigated in this paper. By the code-spectrum approach, it has
been proved in the authors' previous paper that a good linear code for the
authors' JSCC scheme is a code with a good joint spectrum, so the main task in
this paper is to construct linear codes with good joint spectra. First, the
code-spectrum approach is developed further to facilitate the calculation of
spectra. Second, some general principles for constructing good linear codes are
presented. Finally, we propose an explicit construction of linear codes with
good joint spectra based on low density parity check (LDPC) codes and low
density generator matrix (LDGM) codes.


title:
Partition Functions of Torsion >1 Dyons in Heterotic String Theory on
  T^6

abstract:
  The original proposal of Dijkgraaf, Verlinde and Verlinde for the quarter BPS
dyon partition function in heterotic string theory on T^6 is known to correctly
produce the degeneracy of dyons of torsion 1, i.e. dyons for which gcd(Q\wedge
P)=1. We propose a generalization of this formula for dyons of arbitrary
torsion. Our proposal satisfies the constraints coming from S-duality
invariance, wall crossing formula, black hole entropy and the gauge theory
limit. Furthermore using our proposal we derive a general wall crossing formula
that is valid even when both the decay products are non-primitive half-BPS
dyons.