title:
Time-dependent magnetotransport of a wave packet in a quantum wire with
  embedded quantum dots

abstract:
  We consider wave packet propagation in a quantum wire with either an embedded
antidot or an embedded parallel double open quantum dot under the influence of
a uniform magnetic field. The magnetoconductance and the time evolution of an
electron wave packet are calculated based on the Lippmann-Schwinger formalism.
This approach allows us to look at arbitrary embedded potential profiles and
illustrate the results by performing computational simulations for the
conductance and the time evolution of the electron wave packet through the
quantum wire. In the double-dot system we observe a long-lived resonance state
that enhances the spatial spreading of the wave packet, and quantum
skipping-like trajectories are induced when the envelop function of the wave
packet covers several subbands in appropriate magnetic fields.


title:
Solutions to the nonlinear Schroedinger equation carrying momentum along
  a curve. Part II: proof of the existence result

abstract:
  We prove existence of a special class of solutions to the (elliptic)
Nonlinear Schroedinger Equation $- \epsilon^2 \Delta \psi + V(x) \psi =
|\psi|^{p-1} \psi$ on a manifold or in the Euclidean space. Here V represents
the potential, p is an exponent greater than 1 and $\epsilon$ a small parameter
corresponding to the Planck constant. As $\epsilon$ tends to zero (namely in
the semiclassical limit) we prove existence of complex-valued solutions which
concentrate along closed curves, and whose phase in highly oscillatory.
Physically, these solutions carry quantum-mechanical momentum along the limit
curves. In the first part of this work we identified the limit set and
constructed approximate solutions, while here we give the complete proof of our
main existence result.


title: Kinematical Constraints on QCD Factorization in the Drell-Yan Process

abstract:
  We study factorization schemes for parton shower models in hadron-hadron
collisions. As an example, we calculate lepton pair production mediated by a
virtual photon in quark--anti-quark annihilation, and we compare factorized
cross sections obtained in the conventional $\bar{\rm MS}$ scheme with those
obtained in a factorization scheme in which a kinematical constraint due to
parton radiation is taken into account. We discuss some properties of
factorized cross sections.


title:
An evolutionary study of the pulsating subdwarf B eclipsing binary
  PG1336-018 (NY Vir)

abstract:
  The formation of subdwarf B (sdB) stars is not well understood within the
current framework of stellar single and binary evolution. In this study, we
focus on the formation and evolution of the pulsating sdB star in the very
short-period eclipsing binary PG1336-018. We aim at refining the formation
scenario of this unique system, so that it can be confronted with observations.
We probe the stellar structure of the progenitors of sdB stars in short-period
binaries using detailed stellar evolution calculations. Applying this to
PG1336-018 we reconstruct the common-envelope phase during which the sdB star
was formed. The results are interpreted in terms of the standard
common-envelope formalism (the alpha-formalism) based on the energy equation,
and an alternative description (the gamma-formalism) using the angular momentum
equation. We find that if the common-envelope evolution is described by the
alpha-formalism, the sdB progenitor most likely experienced a helium flash. We
then expect the sdB mass to be between 0.39 and 0.48 Msun, and the sdB
progenitor initial mass to be below ~2 Msun. However, the results for the
gamma-formalism are less restrictive, and a broader sdB mass range (0.3 - 0.8
Msun) is possible in this case. Future seismic mass determination will give
strong constraints on the formation of PG1336-018 and, in particular, on the CE
phase.


title:
Magnetized String Cosmological Model in Cylindrically Symmetric
  Inhomogeneous Universe with Variable Cosmological-Term $\Lambda$

abstract:
  Cylindrically symmetric inhomogeneous magnetized string cosmological model is
investigated with cosmological term $\Lambda$ varying with time. To get the
deterministic solution, it has been assumed that the expansion ($\theta$) in
the model is proportional to the eigenvalue $\sigma^{1}_{1}$ of the shear
tensor $\sigma^{i}_{j}$. The value of cosmological constant for the model is
found to be small and positive which is supported by the results from recent
supernovae Ia observations. The physical and geometric properties of the model
are also discussed in presence and absence of magnetic field.


title:
Geometric construction of metaplectic covers of $\GL_{n}$ in
  characteristic zero

abstract:
  This paper presents a new construction of the m-fold metaplectic cover of
$\GL_{n}$ over an algebraic number field k, where k contains a primitive m-th
root of unity. A 2-cocycle on $\GL_{n}(\A)$ representing this extension is
given and the splitting of the cocycle on $\GL_{n}(k)$ is found explicitly. The
cocycle is smooth at almost all places of k. As a consequence, a formula for
the Kubota symbol on $\SL_{n}$ is obtained. The construction of the paper
requires neither class field theory nor algebraic K-theory, but relies instead
on naive techniques from the geometry of numbers introduced by W. Habicht and
T. Kubota. The power reciprocity law for a number field is obtained as a
corollary.


title: Principal values for Riesz transforms and rectifiability

abstract:
  Let $E\subset R^d$ with $H^n(E)<\infty$, where H^n stands for the
$n$-dimensional Hausdorff measure. In this paper we prove that E is
n-rectifiable if and only if the limit $$\lim_{\ve\to0}\int_{y\in E:|x-y|>\ve}
\frac{x-y}{|x-y|^{n+1}} dH^n(y)$$ exists H^n-almost everywhere in E. To prove
this result we obtain precise estimates from above and from below for the $L^2$
norm of the n-dimensional Riesz transforms on Lipschitz graphs.


title: Metropolis simulations of the manipulation of DNA strands in solution

abstract: This paper has been withdrawn by the authors.


title: Fluctuating semiflexible polymer ribbon constrained to a ring

abstract:
  Twist stiffness and an asymmetric bending stiffness of a polymer or a polymer
bundle is captured by the elastic ribbon model. We investigate the effects a
ring geometry induces to a thermally fluctuating ribbon, finding bend-bend
coupling in addition to twist-bend coupling. Furthermore, due to the geometric
constraint the polymer's effective bending stiffness increases. A new parameter
for experimental investigations of polymer bundles is proposed: the mean square
diameter of a ribbonlike ring, which is determined analytically in the
semiflexible limit. Monte Carlo simulations are performed which affirm the
model's prediction up to high flexibility.


title:
Suppressing noise-induced intensity pulsations in semiconductor lasers
  by means of time-delayed feedback

abstract:
  We investigate the possibility to suppress noise-induced intensity pulsations
(relaxation oscillations) in semiconductor lasers by means of a time-delayed
feedback control scheme. This idea is first studied in a generic normal form
model, where we derive an analytic expression for the mean amplitude of the
oscillations and demonstrate that it can be strongly modulated by varying the
delay time. We then investigate the control scheme analytically and numerically
in a laser model of Lang-Kobayashi type and show that relaxation oscillations
excited by noise can be very efficiently suppressed via feedback from a
Fabry-Perot resonator.


title:
Constraints on Dissipative Non-Equilibrium Dark Energy Models from
  Recent Supernova Data

abstract:
  Non-critical string cosmologies may be viewed as the analogue of
off-equilibrium models arising within string theory as a result of a cosmically
catastrophic event in the early Universe. Such models entail relaxing-to-zero
dark energies provided by a rolling dilaton field at late times. We discuss
fits of such non-critical models to high-redshift supernovae data, including
the recent ones by HST and ESSENCE and compare the results with those of a
conventional model with Cold Dark Matter and a cosmological constant and a
model invoking super-horizon perturbations.


title: Shintani Cocycles on $\GL_{n}$

abstract:
  The aim of this paper is to define an n-1-cocycle $\sigma$ on $\GL_{n}(\Q)$
with values in a certain space $\hD$ of distributions on
$\A_f^{n}\setminus\{0\}$. Here $\A_f$ denotes the ring of finite ad\`{e}les of
$\Q$, and the distributions take values in the Laurent series
$\C((z_{1},...,z_{n}))$. This cocycle can be used to evaluate special values of
Artin L-functions on number fields at negative integers. The construction
generalizes that of Solomon in the case n=2.


title:
Nuclear matrix elements of neutrinoless double beta decay with improved
  short-range correlations

abstract:
  Nuclear matrix elements of the neutrinoless double beta decays of 96Zr,
100Mo, 116Cd, 128Te, 130Te and 136Xe are calculated for the light-neutrino
exchange mechanism by using the proton-neutron quasiparticle random-phase
approximation (pnQRPA) with a realistic nucleon-nucleon force. The g_pp
parameter of the pnQRPA is fixed by the data on the two-neutrino double beta
decays and single beta decays. The finite size of a nucleon, the higher-order
terms of nucleonic weak currents, and the nucleon-nucleon short-range
correlations (s.r.c) are taken into account. The s.r.c. are computed by the
traditional Jastrow method and by the more advanced unitary correlation
operator method (UCOM). Comparison of the results obtained by the two methods
is carried out. The UCOM computed matrix elements turn out to be considerably
larger than the Jastrow computed ones. This result is important for the
assessment of the neutrino-mass sensitivity of the present and future double
beta experiments.


title:
Fast computation of the Gauss hypergeometric function with all its
  parameters complex with application to the Poschl-Teller-Ginocchio potential
  wave functions

abstract:
  The fast computation of the Gauss hypergeometric function 2F1 with all its
parameters complex is a difficult task. Although the 2F1 function verifies
numerous analytical properties involving power series expansions whose
implementation is apparently immediate, their use is thwarted by instabilities
induced by cancellations between very large terms. Furthermore, small areas of
the complex plane are inaccessible using only 2F1 power series formulas, thus
rendering 2F1 evaluations impossible on a purely analytical basis. In order to
solve these problems, a generalization of R.C. Forrey's transformation theory
has been developed. The latter has been successful in treating the 2F1 function
with real parameters. As in real case transformation theory, the large
canceling terms occurring in 2F1 analytical formulas are rigorously dealt with,
but by way of a new method, directly applicable to the complex plane. Taylor
series expansions are employed to enter complex areas outside the domain of
validity of power series analytical formulas. The proposed algorithm, however,
becomes unstable in general when |a|,|b|,|c| are moderate or large. As a
physical application, the calculation of the wave functions of the analytical
Poschl-Teller-Ginocchio potential involving 2F1 evaluations is considered.


title: Resistance noise in Bi_2Sr_2CaCu_2O$_{8+\delta}$

abstract:
  The resistance noise in a Bi_2Sr_2CaCu_2O$_{8+\delta}$ thin film is found to
increase strongly in the underdoped regime. While the increase of the raw
resistance noise with decreasing temperature appears to roughly track the
previously reported pseudogap temperature for this material, standard noise
analysis rather suggests that the additional noise contribution is driven by
the proximity of the superconductor-insulator transition.


title: Interacting holographic generalized Chaplygin gas model

abstract:
  In this paper we consider a correspondence between the holographic dark
energy density and interacting generalized Chaplygin gas energy density in FRW
universe. Then we reconstruct the potential of the scalar field which describe
the generalized Chaplygin cosmology.


title: Sum rules for B-->pi eta('), K eta('), eta(') eta(') decays

abstract:
  We provide a set of sum rules, using flavour symmetries, relating CP-averaged
ratios and CP asymmetries of different neutral and charged B mesons decaying
into an eta(') particle together with a pion, a kaon or a second eta('). These
sume rules allow us to give a prediction for the B^0-->K^0 eta branching ratio.
We also predict a clear sign anti-correlation between the two B^0-->pi^0
(eta,eta') CP-asymmetries, and find a combined constraint on the branching
ratios and CP-asymmetries of the three B-->eta(')eta(') decay modes.


title: A case study of the Hirsch index for 26 non-prominent physicists

abstract:
  The h index was introduced by Hirsch to quantify an individual's scientific
research output. It has been widely used in different fields to show the
relevance of the research work of prominent scientists. I have worked out 26
practical cases of physicists which are not so prominent. Therefore this case
study should be more relevant to discuss various features of the Hirsch index
which are interesting or disturbing or both for the more average situation. In
particular, I investigate quantitatively some pitfalls in the evaluation and
the influence of self-citations.


abstract:
  Discussion of ``2004 IMS Medallion Lecture: Local Rademacher complexities and
oracle inequalities in risk minimization'' by V. Koltchinskii [arXiv:0708.0083]


title:
Cosmological Constraints on Radion Evolution in the Universal Extra
  Dimension Model

abstract:
  The constraints on the radion evolution in the Universal Extra Dimension
(UED) model from Cosmic Microwave Background (CMB) and Type Ia supernovae (SNe
Ia) data are studied. In the UED model, where both the gravity and standard
model fields can propagate in the extra dimensions, the evolution of the extra
dimensional volume, the radion, induces variation of fundamental constants. We
discuss the effects of variation of the relevant constants in the context of
UED for CMB power spectrum and SNe Ia data. We then use the three-year WMAP
data to constrain the radion evolution at z \sim 1100, and the 2 \sigma
constraint on \dot{\rho} / \rho_0 (\rho is a function of the radion, to be
defined in the text) is [ -8.8, 6.6] \times 10 ^{-13} yr^-1. The SNe Ia gold
sample yields a constraint on \dot{\rho} / \rho_0, for redshift between 0 and
1, to be [-4.7, 14] \times 10^{-13} yr^-1. Furthermore, the constraints from
SNe Ia can be interpreted as bounds on the evolution QCD scale parameter,
\dot{\Lambda}_{QCD} / \Lambda_{QCD, 0}, [-1.4, 2.8] \times 10^{-11} yr^-1,
without reference to the UED model.


title: SuperAGILE: the hard X-ray Imager for the AGILE space mission

abstract:
  SuperAGILE is a coded mask experiment based on silicon microstrip detectors.
It operates in the 15-45 keV nominal energy range, providing crossed
one-dimensional images of the X-ray sky with an on-axis angular resolution of 6
arcmin, over a field of view in excess of 1 steradian. It was designed as the
hard X-ray monitor of the AGILE space mission, a small satellite of the Italian
Space Agency devoted to image the gamma-ray sky in the 30 MeV - 50 GeV energy
band. The AGILE mission was launched in a low-earth orbit on 23^{rd} April
2007. In this paper we describe the SuperAGILE experiment, its construction and
test processes, and its performance before flight, based on the on-ground test
and calibrations.


title:
Discussion of ``2004 IMS Medallion Lecture: Local Rademacher
  complexities and oracle inequalities in risk minimization'' by V.
  Koltchinskii


title:
Solutions to the nonlinear Schroedinger equation carrying momentum along
  a curve. Part I: study of the limit set and approximate solutions

abstract:
  We prove existence of a special class of solutions to the (elliptic)
Nonlinear Schroeodinger Equation $- \epsilon^2 \Delta \psi + V(x) \psi =
|\psi|^{p-1} \psi$, on a manifold or in the Euclidean space. Here V represents
the potential, p an exponent greater than 1 and $\epsilon$ a small parameter
corresponding to the Planck constant. As $\epsilon$ tends to zero (namely in
the semiclassical limit) we prove existence of complex-valued solutions which
concentrate along closed curves, and whose phase is highly oscillatory.
Physically, these solutions carry quantum-mechanical momentum along the limit
curves. In this first part we provide the characterization of the limit set,
with natural stationarity and non-degeneracy conditions. We then construct an
approximate solution up to order $\epsilon^2$, showing that these conditions
appear naturally in a Taylor expansion of the equation in powers of $\epsilon$.
Based on these, an existence result will be proved in the second part.


title:
Monte Carlo simulations of the L10 long-range order relaxation in
  dimensionally reduced systems

abstract:
  Monte Carlo simulations have been performed to investigate the relaxation of
the L10 long-range order in dimensionally reduced systems. The effect of the
number of (001)-type monatomic layers and of the pair interaction energies on
these kinetics has been examined. The vacancy migration energies have been
deduced from the Arrhenius plots of the relaxation times. A substantial
increase in the migration energy for small film thickness is observed. The
results agree with previous Monte Carlo simulations and with recent
experimental results in L1_0 thin films and multilayers.


title: Accuracy control in ultra-large-scale electronic structure calculation

abstract:
  Numerical aspects are investigated in ultra-large-scale electronic structure
calculation. Accuracy control methods in process (molecular-dynamics)
calculation are focused. Flexible control methods are proposed so as to control
variational freedoms, automatically at each time step, within the framework of
generalized Wannier state theory. The method is demonstrated in silicon
cleavage simulation with 10^2-10^5 atoms. The idea is of general importance
among process calculations and is also used in Krylov subspace theory, another
large-scale-calculation theory.


title:
The alternating marked point process of h-slopes of the drifted Brownian
  motion

abstract:
  We show that the slopes between h-extrema of the drifted 1D Brownian motion
form a stationary alternating marked point process, extending the result of J.
Neveu and J. Pitman for the non drifted case. Our analysis covers the results
on the statistics of h-extrema obtained by P. Le Doussal, C. Monthus and D.
Fisher via a Renormalization Group analysis and gives a complete description of
the slope between h-extrema covering the origin by means of the Palm--Khinchin
theory. Moreover, we analyze the behavior of the Brownian motion near its
h-extrema.


title:
Low temperature specific heat of La_{3}Pd_{4}Ge_{4} with
  U_{3}Ni_{4}Si_{4}-type structure

abstract:
  Low temperature specific heat has been investigated in a novel ternary
superconductor La_{3}Pd_{4}Ge_{4} with an U_{3}Ni_{4}Si_{4}-type structure
consisting of the alternating BaAl_{4} (ThCr_{2}Si_{2})- and AlB$_{2}$-type
layers. A comparative study with the related ThCr_{2}Si_{2}-type superconductor
LaPd_{2}Ge_{2}, one of the layers in La_{3}Pd_{4}Ge_{4}, is also presented.
  From the normal state specific heat, the Sommerfeld coefficient $\gamma_{n} =
27.0$ mJ/mol K^2 and the Debye temperature $\Theta_{\rm D}$ = 256 K are derived
for the La_{3}Pd_{4}Ge_{4}, while those for the LaPd_{2}Ge_{2} are $\gamma_{n}
=8.26$ mJ/mol K^2 and $\Theta_{\rm D}$ = 291 K. The La_{3}Pd_{4}Ge_{4} has
moderately high electronic density of state at the Fermi level. Electronic
contribution on the specific heat, $C_{\rm el}$, in each compound is well
described by the BCS behavior, suggesting that both of the La_{3}Pd_{4}Ge_{4}
and the LaPd_{2}Ge_{2} have fully opened isotropic gap in the superconducting
state.


title: Lowest Weights in Cohomology of Variations of Hodge Structure

abstract:
  Let X be a smooth complex projective variety, let $j:U\into X$ an immersion
of a Zariski open subset, and let V be a variation of Hodge structure of weight
n over U. Then IH^k(X, j_*V) is known to carry a pure Hodge structure of weight
k+n, while H^k(U,V) carries a mixed Hodge structure of weight $\ge k+n$. In
this note it is shown that the image of the natural map $IH^k(X,j_*V) \to
H^k(U,V)$ is the lowest weight part of this mixed Hodge structure. The proof
uses Saito's theory of mixed Hodge modules.


title: On the Density Dependent Nuclear Matter Compressibility

abstract:
  In the present work we apply a quantum hadrodynamic effective model in the
mean-field approximation to the description of neutron stars. We consider an
adjustable derivative-coupling model and study the parameter influence on the
dynamics of the system by analyzing the full range of values they can take. We
establish a set of parameters which define a specific model that is able to
describe phenomenological properties such as the effective nucleon mass at
saturation as well as global static properties of neutron stars (mass and
radius). If one uses observational data to fix the maximum mass for neutron
stars by a specific model, we are able to predict the compression modulus of
nuclear matter K = 257,2MeV.


title: The clumpy structure of the chemically active L1157 outflow

abstract:
  We present high spatial resolution maps, obtained with the Plateau de Bure
Interferometer, of the blue lobe of the L1157 outflow. We observed four lines
at 3 mm, namely CH3OH (2_K-1_K), HC3N (11-10), HCN (1-0) and OCS (7-6).
Moreover, the bright B1 clump has also been observed at better spatial
resolution in CS (2-1), CH3OH (2_1-1_1)A-, and 34SO (3_2-2_1). These high
spatial resolution observations show a very rich structure in all the tracers,
revealing a clumpy structure of the gas superimposed to an extended emission.
In fact, the three clumps detected by previous IRAM-30m single dish
observations have been resolved into several sub-clumps and new clumps have
been detected in the outflow. The clumps are associated with the two cavities
created by two shock episodes driven by the precessing jet. In particular, the
clumps nearest the protostar are located at the walls of the younger cavity
with a clear arch-shape form while the farthest clumps have slightly different
observational characteristics indicating that they are associated to the older
shock episode. The emission of the observed species peaks in different part of
the lobe: the east clumps are brighter in HC3N (11-10), HCN (1-0) and CS (2-1)
while the west clumps are brighter in CH3OH(2_K-1_K), OCS (7-6) and 34SO
(3_2-2_1). This peak displacement in the line emission suggests a variation of
the physical conditions and/or the chemical composition along the lobe of the
outflow at small scale, likely related to the shock activity and the precession
of the outflow. In particular, we observe the decoupling of the silicon
monoxide and methanol emission, common shock tracers, in the B1 clump located
at the apex of the bow shock produced by the second shock episode.


title: LHC Physics and Cosmology

abstract:
  In these Lectures I review possible constraints on particle physics models,
obtained by means of combining the results of collider measurements with
astrophysical data. I emphasize the theoretical-model dependence of these
results. I discuss supersymmetric dark matter constraints at colliders (mainly
LHC) in various theoretical contexts: the standard
Cosmological-Constant-Cold-Dark-Matter (Lambda-CDM) model,
(super)string-inspired ones and non-equilibrium relaxation dark energy models.
I then investigate the capability of LHC measurements in asserting whether
supersymmetric matter (if discovered) constitutes part, or all, of the
astrophysical dark matter. I also discuss prospects for improving the
constraints in future precision facilities, such as the International Linear
Collider.


abstract:
  Rejoinder: 2004 IMS Medallion Lecture: Local Rademacher complexities and
oracle inequalities in risk minimization [arXiv:0708.0083]


title: Harmonic morphisms from solvable Lie groups

abstract:
  In this paper we introduce two new methods for constructing harmonic
morphisms from solvable Lie groups. The first method yields global solutions
from any simply connected nilpotent Lie group and from any Riemannian symmetric
space of non-compact type and rank $r\ge 3$. The second method provides us with
global solutions from any Damek-Ricci space and many non-compact Riemannian
symmetric spaces. We then give a continuous family of 3-dimensional solvable
Lie groups not admitting any complex valued harmonic morphisms, not even
locally.


title: Viscosity in the excluded volume hadron gas model

abstract:
  The shear viscosity $\eta$ in the van der Waals excluded volume
hadron-resonance gas model is considered. For the shear viscosity the result of
the non-relativistic gas of hard-core particles is extended to the mixture of
particles with different masses, but equal values of hard-core radius r. The
relativistic corrections to hadron average momenta in thermal equilibrium are
also taken into account. The ratio of the viscosity $\eta$ to the entropy
density s is studied. It monotonously decreases along the chemical freeze-out
line in nucleus-nucleus collisions with increasing collision energy. As a
function of hard-core radius r, a broad minimum of the ratio $\eta/s\approx
0.3$ near $r \approx 0.5$ fm is found at high collision energies. For the
charge-neutral system at $T=T_c=180$ MeV, a minimum of the ratio $\eta/s\cong
0.24$ is reached for $r\cong 0.53$ fm. To justify a hydrodynamic approach to
nucleus-nucleus collisions within the hadron phase the restriction from below,
$r~ \ge ~0.2$ fm, on the hard-core hadron radius should be fulfilled in the
excluded volume hadron-resonance gas.


title: Self-similar branching Markov chains

abstract:
  The main purpose of this work is to study self-similar branching Markov
chains. First we will construct such a process. Then we will establish certain
Limit Theorems using the theory of self-similar Markov processes.


title: Suppressed Decays of D_s^+ Mesons to Two Pseudoscalar Mesons

abstract:
  Using data collected near the Ds*+ Ds- peak production energy Ecm = 4170 MeV
by the CLEO-c detector, we study the decays of Ds+ mesons to two pseudoscalar
mesons. We report on searches for the singly-Cabibbo-suppressed Ds+ decay modes
K+ eta, K+ eta', pi+ K0S, K+ pi0, and the isospin-forbidden decay mode Ds+ to
pi+ pi0. We normalize with respect to the Cabibbo-favored Ds+ modes pi+ eta,
pi+ eta', and K+ K0S, and obtain ratios of branching fractions: Ds+ to K+ eta /
Ds+ to pi+ eta = (8.9 +- 1.5 +- 0.4)%, Ds+ to K+ eta' / Ds+ to pi+ eta' = (4.2
+- 1.3 +- 0.3)%, Ds+ to pi+ K0S / Ds+ to K+ K0S = (8.2 +- 0.9 +- 0.2)%, Ds+ to
K+ pi0 / Ds+ to K+ K0S = (5.0 +- 1.2 +- 0.6)%, and Ds+ to pi+ pi0 / Ds+ to K+
K0S < 4.1% at 90% CL, where the uncertainties are statistical and systematic,
respectively.


title:
Optical and Near-Infrared Observations of the Highly Reddened, Rapidly
  Expanding Type Ia Supernova 2006X in M100

abstract:
  We present extensive optical (UBVRI), near-infrared (JK) light curves and
optical spectroscopy of the Type Ia supernova (SN) 2006X in the nearby galaxy
NGC 4321 (M100). Our observations suggest that either SN 2006X has an
intrinsically peculiar color evolution, or it is highly reddened [E(B -
V)_{host} = 1.42+/-0.04 mag] with R_V = 1.48+/-0.06, much lower than the
canonical value of 3.1 for the average Galactic dust. SN 2006X also has one of
the highest expansion velocities ever published for a SN Ia. Compared with the
other SNe Ia we analyzed, SN 2006X has a broader light curve in the U band, a
more prominent bump/shoulder feature in the V and R bands, a more pronounced
secondary maximum in the I and near-infrared bands, and a remarkably smaller
late-time decline rate in the B band. The B - V color evolution shows an
obvious deviation from the Lira-Phillips relation at 1 to 3 months after
maximum brightness. At early times, optical spectra of SN 2006X displayed
strong, high-velocity features of both intermediate-mass elements (Si, Ca, and
S) and iron-peak elements, while at late times they showed a relatively blue
continuum, consistent with the blue U-B and B-V colors at similar epochs. A
light echo and/or the interaction of the SN ejecta and its circumstellar
material may provide a plausible explanation for its late-time photometric and
spectroscopic behavior. Using the Cepheid distance of M100, we derive a Hubble
constant of 72.7+/-8.2 km s^{-1} Mpc^{-1}(statistical) from the normalized
dereddened luminosity of SN 2006X. We briefly discuss whether abnormal dust is
a universal signature for all SNe Ia, and whether the most rapidly expanding
objects form a subclass with distinct photometric and spectroscopic properties.


title:
Using ultra-short pulses to determine particle size and density
  distributions

abstract:
  We analyze the time dependent response of strongly scattering media (SSM) to
ultra-short pulses of light. A random walk technique is used to model the
optical scattering of ultra-short pulses of light propagating through media
with random shapes and various packing densities. The pulse spreading was found
to be strongly dependent on the average particle size, particle size
distribution, and the packing fraction. We also show that the intensity as a
function of time-delay can be used to analyze the particle size distribution
and packing fraction of an optically thick sample independently of the presence
of absorption features. Finally, we propose an all new way to measure the shape
of ultra-short pulses that have propagated through a SSM.


title: The 4th Concept Detector for the International Linear Collider

abstract:
  The 4th Concept detector presently being designed for the International
Linear Collider introduces several innovations in order to achieve the
necessary experimental goal of a detecter that is 2-to-10 times better than the
already excellent SLC and LEP detectors. We introduce a dual-readout
calorimeter system, a cluster counting drift chamber, and a second solenoid to
return the magnetic flux without iron. We discuss particle identification,
momentum and energy resolutions, and the machine-detector interface that
together offer the possibility of a very high-performance detector for
e^+e^-physics up to $\sqrt{s} = 1$ TeV.


title:
Nonparametric quasi-maximum likelihood estimation for Gaussian locally
  stationary processes

abstract:
  This paper deals with nonparametric maximum likelihood estimation for
Gaussian locally stationary processes. Our nonparametric MLE is constructed by
minimizing a frequency domain likelihood over a class of functions. The
asymptotic behavior of the resulting estimator is studied. The results depend
on the richness of the class of functions. Both sieve estimation and global
estimation are considered. Our results apply, in particular, to estimation
under shape constraints. As an example, autoregressive model fitting with a
monotonic variance function is discussed in detail, including algorithmic
considerations. A key technical tool is the time-varying empirical spectral
process indexed by functions. For this process, a Bernstein-type exponential
inequality and a central limit theorem are derived. These results for empirical
spectral processes are of independent interest.


title:
Magnetic Field Structure in the Parsec Scale Jet of 3C273 from
  Multifrequency VLBA Observations

abstract:
  We present first results from a multifrequency VLBA observations of 3C273 in
2003. The source was observed simultaneously at 5.0, 8.4, 15.3, 22.2, 43.2 and
86.2 GHz, and from this multifrequency data set, spectra of 16 emission
features in the parsec scale jet were carefully constructed by using a new
model-fitting based method. The measured spectra and sizes of the emission
features were used to calculate the magnetic field density and the energy
density of the relativistic electrons in the different parts of the parsec
scale jet, independent of any equipartition assumption. We measure magnetic
field density of an order of 1 Gauss in the core. The magnetic energy density
in the core dominates over that of the relativistic electrons, while in the
downstream region our data are roughly consistent with an equipartition. A
strong gradient in the magnetic field density across the jet width, coincident
with a transverse velocity structure at about 1.5 mas from the core, was found:
the slower superluminal component B2 on the northern side of the jet has a
magnetic field density two orders of magnitude lower than the faster southern
components B3 and B4.


title: Programmable Quantum State Transfer

abstract:
  A programmable quantum networks model is used in this paper for development
of methods of control of a quantum state transport. These methods may be
applied for a wide variety of patterns of controlled state transmission and
spreading in quantum systems. The programmable perfect state transfer and
quantum walk, mobile quantum (ro)bots and lattice gas automata may be described
by unified way with such approach.


title: A Side of Mercury Not Seen By Mariner 10

abstract:
  More than 60,000 images of Mercury were taken at ~29 deg elevation during two
sunrises, at 820 nm, and through a 1.35 m diameter off-axis aperture on the
SOAR telescope. The sharpest resolve 0.2" (140 km) and cover 190-300 deg
longitude -- a swath unseen by the Mariner 10 spacecraft -- at complementary
phase angles to previous ground-based optical imagery. Our view is comparable
to that of the Moon through weak binoculars. Evident are the large crater
Mozart shadowed on the terminator, fresh rayed craters, and other albedo
features keyed to topography and radar reflectivity, including the putative
huge ``Basin S'' on the limb. Classical bright feature Liguria resolves across
the northwest boundary of the Caloris basin into a bright splotch centered on a
sharp, 20 km diameter radar crater, and is the brightest feature within a
prominent darker ``cap'' (Hermean feature Solitudo Phoenicis) that covers the
northern hemisphere between longitudes 140-250 deg. The cap may result from
space weathering that darkens via a magnetically enhanced flux of the solar
wind, or that reddens low latitudes via high solar insolation.


title: Control of unstable steady states by extended time-delayed feedback

abstract:
  Time-delayed feedback methods can be used to control unstable periodic orbits
as well as unstable steady states. We present an application of extended time
delay autosynchronization introduced by Socolar et al. to an unstable focus.
This system represents a generic model of an unstable steady state which can be
found for instance in a Hopf bifurcation. In addition to the original
controller design, we investigate effects of control loop latency and a
bandpass filter on the domain of control. Furthermore, we consider coupling of
the control force to the system via a rotational coupling matrix parametrized
by a variable phase. We present an analysis of the domain of control and
support our results by numerical calculations.


title: Modelling the behaviour of accretion flows in X-ray binaries

abstract:
  (abridged) We review how the recent increase in X-ray and radio data from
black hole and neutron star binaries can be merged together with theoretical
advances to give a coherent picture of the physics of the accretion flow in
strong gravity. Both long term X-ray light curves, X-ray spectra, the rapid
X-ray variability and the radio jet behaviour are consistent with a model where
a standard outer accretion disc is truncated at low luminosities, being
replaced by a hot, inner flow which also acts as the launching site of the jet.
Decreasing the disc truncation radius leads to softer spectra, as well as
higher frequencies (including QPO's) in the power spectra, and a faster jet.
The collapse of the hot flow when the disc reaches the last stable orbit
triggers the dramatic decrease in radio flux, as well as giving a qualitative
(and often quantitative) explanation for the major hard--soft spectral
transition seen in black holes and neutron stars.
  After collapse of the hot inner flow, the spectrum in black hole systems can
be dominated by the disc emission. Its behaviour is consistent with the
existence of a last stable orbit, and such data can be used to estimate the
black hole spin. These systems can also show very different spectra at these
high luminosities, in which the disc spectrum is strongly distorted by
Comptonization. The structure of the accretion flow becomes increasingly
uncertain as the luminosity approaches (and exceeds) the Eddington luminosity,
though there is growing evidence that winds play an important role. We stress
that these high Eddington fraction flows are key to understanding many
disparate and currently very active fields such as ULX, Narrow Line Seyfert
1's, and the growth of the first black holes in the Early Universe.


title: Modeling the spectral energy distribution of ULIRGs I: the radio spectra

abstract:
  As a constraint for new starburst/AGN models of IRAS bright galaxies we
determine the radio spectra of 31 luminous and ultraluminous IRAS galaxies
(LIRGs/ULIRGs). We construct the radio spectra using both new and archival
data. From our sample of radio spectra we find that very few have a straight
power-law slope. Although some sources show a flattening of the radio spectral
slope at high frequencies the average spectrum shows a steepening of the radio
spectrum from 1.4 to 22.5 GHz. This is unexpected because in sources with high
rates of star formation we expect flat spectrum, free-free emission to make a
significant contribution to the radio flux at higher radio frequencies. Despite
this trend the radio spectral indices between 8.4 and 22.5 GHz are flatter for
sources with higher values of the FIR-radio flux density ratio q, when this is
calculated at 8.4 GHz. Therefore, sources that are deficient in radio emission
relative to FIR emission (presumably younger sources) have a larger thermal
component to their radio emission. However, we find no correlation between the
radio spectral index between 1.4 and 4.8 GHz and q at 8.4 GHz. Because the low
frequency spectral index is affected by free-free absorption, and this is a
function of source size for a given mass of ionized gas, this is evidence that
the ionized gas in ULIRGs shows a range of densities. The youngest LIRGs and
ULIRGs are characterized by a larger contribution to their high-frequency radio
spectra from free-free emission. However, the youngest sources are not those
that have the greatest free-free absorption at low radio frequencies. The
sources in which the effects of free-free absorption are strongest are instead
the most compact sources. Although these have the warmest FIR colours, they are
not necessarily the youngest sources.


title: Range-based attacks on links in random scale-free networks

abstract:
  $Range$ and $load$ play keys on the problem of attacking on links in random
scale-free (RSF) networks. In this Brief Report we obtain the relation between
$range$ and $load$ in RSF networks analytically by the generating function
theory, and then give an estimation about the impact of attacks on the
$efficiency$ of the network. The analytical results show that short range
attacks are more destructive for RSF networks, and are confirmed numerically.
Further our results are consistent with the former literature (Physical Review
E \textbf{66}, 065103(R) (2002)).


title: Nonisomorphic Verdier octahedra on the same base

abstract:
  We show by an example that in a Verdier triangulated category, there may
exist two mutually nonisomorphic Verdier octahedra containing the same
commutative triangle.


title: Non-standard neutrino interactions in reactor and superbeam experiments

abstract:
  The formalism of non-standard four-fermion interactions provides a
convenient, model-independent way of parameterizing a wide class of ``new
physics'' scenarios. In this article, we study the performance of reactor and
superbeam neutrino experiments in the presence of such non-standard
interactions (NSI). Due to interference between the standard and non-standard
amplitudes, sizeable effects are to be expected if the NSI parameters are close
to their current upper limits. We derive approximate formulas for the relevant
oscillation probabilities including NSI, and show how the leading effects can
be understood intuitively even without any calculations. We will present a
classification of all possible NSI according to their impact on reactor and
superbeam experiments, and it will turn out that these experiments are highly
complementary in terms of their sensitivity to the non-standard parameters. The
second part of the paper is devoted to detailed numerical simulations, which
will demonstrate how a standard oscillation fit of the mixing angle theta-13
may fail if experimental data is affected by NSI. We find that for some
non-standard terms, reactor and superbeam experiments would yield seemingly
conflicting results, while in other cases, they may agree well with each other,
but the resulting value for theta-13 could be far from the true value. This
offset may be so large that the true theta-13 is even ruled out erroneously. In
the last section of the paper, we demonstrate that reactor and superbeam data
can actually establish the presence of non-standard interactions. Throughout
our discussion, we pay special attention to the impact of the complex phases,
and of the near detectors.


title: The entropy of randomized network ensembles

abstract:
  Randomized network ensembles are the null models of real networks and are
extensivelly used to compare a real system to a null hypothesis. In this paper
we study network ensembles with the same degree distribution, the same
degree-correlations or the same community structure of any given real network.
We characterize these randomized network ensembles by their entropy, i.e. the
normalized logarithm of the total number of networks which are part of these
ensembles.
  We estimate the entropy of randomized ensembles starting from a large set of
real directed and undirected networks. We propose entropy as an indicator to
assess the role of each structural feature in a given real network.We observe
that the ensembles with fixed scale-free degree distribution have smaller
entropy than the ensembles with homogeneous degree distribution indicating a
higher level of order in scale-free networks.


title: Upper limit on the transition temperature for non-ideal Bose gases

abstract:
  In this paper we show that for a non-ideal Bose gas there exists an upper
limit on the transition temperature above which Bose-Einstein condensation
cannot occur regardless of the pressure applied. Such upper limits for some
realistic Bose gases are estimated. This result implies that there may also
exist an upper limit on the transition temperature of superconductors.


title: Is D_s(2700) a charmed tetraquark state ?

abstract:
  In this article, we take the point of view that the $D_s(2700)$ be a
tetraquark state, which consists of a scalar diquark and a vector antidiquark,
and calculate its mass with the QCD sum rules. The numerical result indicates
that the mass of the vector charmed tetraquark state is about
$M_V=(3.75\pm0.18)\rm{GeV}$ or $M_V=(3.71\pm0.15)\rm{GeV}$ from different sum
rules, which is about $1\rm{GeV}$ larger than the experimental data. Such
tetraquark component should be very small in the $D_s(2700)$.


title:
Nucleosome Chiral Transition under Positive Torsional Stress in Single
  Chromatin Fibers

abstract:
  Using magnetic tweezers to investigate the mechanical response of single
chromatin fibers, we show that fibers submitted to large positive torsion
transiently trap positive turns, at a rate of one turn per nucleosome. A
comparison with the response of fibers of tetrasomes (the (H3-H4)2 tetramer
bound with ~50 bp of DNA) obtained by depletion of H2A-H2B dimers, suggests
that the trapping reflects a nucleosome chiral transition to a metastable form
built on the previously documented righthanded tetrasome. In view of its low
energy, <8 kT, we propose this transition is physiologically relevant and
serves to break the docking of the dimers on the tetramer which in the absence
of other factors exerts a strong block against elongation of transcription by
the main RNA polymerase.


title: Matrix Factorizations, D-Branes and their Deformations

abstract:
  We review in elementary, non-technical terms the description of topological
B-type of D-branes in terms of boundary Landau-Ginzburg theory, as well as some
applications.


title:
A Compton Thick AGN Powering the Hyperluminous Infrared Galaxy IRAS
  00182--7112

abstract:
  We present X-ray observations of the Hyperluminous Infrared Galaxy (HLIRG)
IRAS 00182--7112 (F00183--7111) obtained using the XMM-Newton EPIC camera. A
luminous hard X-ray source co-incident with the nucleus is revealed, along with
weaker soft X-ray emission which may be extended or offset from the hard. The
EPIC spectrum is extremely flat and shows Fe K$\alpha$ emission with very high
equivalent width: both are typical characteristics of a buried, Compton--thick
AGN which is seen only in scattered light. Perhaps the most remarkable
characteristic of the spectrum is that the Fe K$\alpha$ line energy is that of
He-like iron, making IRAS 00182--7112 the first hidden AGN known to be
dominated by ionized, Compton thick reflection. Taking an appropriate
bolometric correction we find that this AGN could easily dominate the FIR
energetics. The nuclear reflection spectrum is seen through a relatively cold
absorber with column density consistent with recent Spitzer observations. The
soft X-ray emission, which may be thermal in nature and associated with
star-forming activity, is seen unabsorbed. The soft X-rays and weak PAH
features both give estimates of the star formation rate $\sim 300 M_{\odot}$
yr$^{-1}$, insufficient to power the FIR emission and supportive of the idea
that this HLIRG is AGN-dominated.


title: Possible Way to Synthesize Superheavy Element Z=117

abstract:
  Within the framework of the dinuclear system model, the production of
superheavy element Z=117 in possible projectile-target combinations is analyzed
systematically. The calculated results show that the production cross sections
are strongly dependent on the reaction systems. Optimal combinations,
corresponding excitation energies and evaporation channels are proposed in this
letter, such as the isotopes ^{248,249}Bk in ^{48}Ca induced reactions in 3n
evaporation channels and the reactions ^{45}Sc+^{246,248}Cm in 3n and 4n
channels, and the system ^{51}V+^{244}Pu in 3n channel.


title: Colliding neutrino beams

abstract:
  From several neutrino oscillation experiments, we understand now that
neutrinos have mass. However, we really don't know what mechanism is
responsible for producing this neutrino mass. Current or planned neutrino
experiments utilize neutrino beams and long-baseline detectors to explore
flavor mixing but do not address the question of the origin of neutrino mass.
In order to answer that question, neutrino interactions need to be explored at
much higher energies. This paper outlines a program to explore neutrinos and
their interactions with various particles through a series of experiments
involving colliding neutrino beams.


title:
Entanglement entropy in quantum spin chains with finite range
  interaction

abstract:
  We study the entropy of entanglement of the ground state in a wide family of
one-dimensional quantum spin chains whose interaction is of finite range and
translation invariant. Such systems can be thought of as generalizations of the
XY model. The chain is divided in two parts: one containing the first
consecutive L spins; the second the remaining ones. In this setting the entropy
of entanglement is the von Neumann entropy of either part. At the core of our
computation is the explicit evaluation of the leading order term as L tends to
infinity of the determinant of a block-Toeplitz matrix whose symbol belongs to
a general class of 2 x 2 matrix functions. The asymptotics of such determinant
is computed in terms of multi-dimensional theta-functions associated to a
hyperelliptic curve of genus g >= 1, which enter into the solution of a
Riemann-Hilbert problem. Phase transitions for thes systems are characterized
by the branch points of the hyperelliptic curve approaching the unit circle. In
these circumstances the entropy diverges logarithmically. We also recover, as
particular cases, the formulae for the entropy discovered by Jin and Korepin
(2004) for the XX model and Its, Jin and Korepin (2005,2006) for the XY model.


title:
Implication of the proton electric FF space-like behavior puzzle in
  various physical phenomena

abstract:
  By means of the 10-resonance unitary and analytic model of nucleon
electromagnetic structure it is demonstrated that the JLab proton polarization
data on the ratio $\mu_p G_{Ep}(Q^2)/G_{Mp}(Q^2)$ are consistent with all form
factor properties, however, they strongly require an existence of the zero in
G_{Ep}(Q^2) around Q^2=13 GeV^2. As a result there are two contradicting
behaviors of G_{Ep}(Q^2) in space-like region. Consequences of this phenomenon
on the charge distribution within the proton, on the saturation of the new
proton-neutron q^2-dependent sum rule, on the behavior of strange nucleon form
factors and the deuteron elastic structure functions through the impulse
approximation are investigated.


title: Vacuum Energy Density in the Quantum Yang - Mills Theory

abstract:
  Using the effective potential approach for composite operators, we have
formulated a general method of calculation of the truly non-perturbative
Yang-Mills vacuum energy density (this is, by definition, the Bag constant
apart from the sign). It is the main dynamical characteristic of the QCD ground
state. Our method allows one to make it free of the perturbative contributions
('contaminations'), by construction. We also perform an actual numerical
calculation of the Bag constant for the confining effective charge. Its choice
uniquely defines the Bag constant, which becomes free of all the types of the
perturbative contributions now, as well as possessing many other desirable
properties as colorless, gauge independence, etc. Using further the trace
anomaly relation, we develop a general formalism which makes it possible to
relate the Bag constant to the gluon condensate not using the weak coupling
solution for the corresponding $\beta$ function. Our numerical result for the
Bag constant shows a good agreement with other phenomenological estimates of
the gluon condensate.


title: Biologically Inspired Nanomaterials: A Conference Report

abstract:
  The understanding of the nanoscale physical properties of biomolecules and
biomaterials will ultimately promote the research in the biological sciences.
In this review, we focused on theory, simulation, and experiments involving
nanoscale materials inspired by biological systems. Specifically, self-assembly
in living and synthetic materials, bio-functionalized nanomaterials and probing
techniques that use nanomaterials are discussed.


title: Robust estimates in generalized partially linear models

abstract:
  In this paper, we introduce a family of robust estimates for the parametric
and nonparametric components under a generalized partially linear model, where
the data are modeled by $y_i|(\mathbf{x}_i,t_i)\sim F(\cdot,\mu_i)$ with
$\mu_i=H(\eta(t_i)+\mathbf{x}_i^{$\mathrm{T}$}\beta)$, for some known
distribution function F and link function H. It is shown that the estimates of
$\beta$ are root-n consistent and asymptotically normal. Through a Monte Carlo
study, the performance of these estimators is compared with that of the
classical ones.


title:
Common origin of \theta_{13} and \Delta m^2_{12} in a model of neutrino
  mass with quaternion symmetry

abstract:
  The smallness of the 1-3 lepton mixing angle $\theta_{13}$ and of the
neutrino mass-squared-difference ratio $\Delta m^2_{12}/\Delta m^2_{23}$ can be
understood as the departure from a common limit where they both vanish. We
discuss in general the conditions for realizing the mass degeneracy of a pair
of neutrinos and show that the vanishing of a CP violating phase is needed. We
find that the discrete quaternion group Q of eight elements is the simplest
family symmetry which correlates the smallness of $\Delta m^2_{12}$ to the
value of $\theta_{13}$. In such a model we predict $0.12\lesssim
\sin\theta_{13} \lesssim 0.2$ if the ordering of the neutrino mass spectrum is
normal, and $\sin\theta_{13}\lesssim 0.12$ if it is inverted.


title:
On the limiting distributions of multivariate depth-based rank sum
  statistics and related tests

abstract:
  A depth-based rank sum statistic for multivariate data introduced by Liu and
Singh [J. Amer. Statist. Assoc. 88 (1993) 252--260] as an extension of the
Wilcoxon rank sum statistic for univariate data has been used in multivariate
rank tests in quality control and in experimental studies. Those applications,
however, are based on a conjectured limiting distribution, provided by Liu and
Singh [J. Amer. Statist. Assoc. 88 (1993) 252--260]. The present paper proves
the conjecture under general regularity conditions and, therefore, validates
various applications of the rank sum statistic in the literature. The paper
also shows that the corresponding rank sum tests can be more powerful than
Hotelling's T^2 test and some commonly used multivariate rank tests in
detecting location-scale changes in multivariate distributions.


title:
Topological Free Entropy Dimension in Unital C^* algebras (II) :
  Orthogonal Sum of Unital C^*-algebras

abstract:
  In the paper, we obtain a formula for topological free entropy dimension in
the orthogonal sum (or direct sum) of unital C^* algebras. As a corollary, we
compute the topological free entropy dimension of any family of self-adjoint
generators of a finite dimensional C^* algebra.


title: Data-driven goodness-of-fit tests

abstract:
  We propose and study a general method for construction of consistent
statistical tests on the basis of possibly indirect, corrupted, or partially
available observations. The class of tests devised in the paper contains
Neyman's smooth tests, data-driven score tests, and some types of multi-sample
tests as basic examples. Our tests are data-driven and are additionally
incorporated with model selection rules. The method allows to use a wide class
of model selection rules that are based on the penalization idea. In
particular, many of the optimal penalties, derived in statistical literature,
can be used in our tests. We establish the behavior of model selection rules
and data-driven tests under both the null hypothesis and the alternative
hypothesis, derive an explicit detectability rule for alternative hypotheses,
and prove a master consistency theorem for the tests from the class. The paper
shows that the tests are applicable to a wide range of problems, including
hypothesis testing in statistical inverse problems, multi-sample problems, and
nonparametric hypothesis testing.


title: On the radar method in general-relativistic spacetimes

abstract:
  If a clock, mathematically modeled by a parametrized timelike curve in a
general-relativistic spacetime, is given, the radar method assigns a time and a
distance to every event which is sufficiently close to the clock. Several
geometric aspects of this method are reviewed and their physical interpretation
is discussed.


title: Virtual screening with support vector machines and structure kernels

abstract:
  Support vector machines and kernel methods have recently gained considerable
attention in chemoinformatics. They offer generally good performance for
problems of supervised classification or regression, and provide a flexible and
computationally efficient framework to include relevant information and prior
knowledge about the data and problems to be handled. In particular, with kernel
methods molecules do not need to be represented and stored explicitly as
vectors or fingerprints, but only to be compared to each other through a
comparison function technically called a kernel. While classical kernels can be
used to compare vector or fingerprint representations of molecules, completely
new kernels were developed in the recent years to directly compare the 2D or 3D
structures of molecules, without the need for an explicit vectorization step
through the extraction of molecular descriptors. While still in their infancy,
these approaches have already demonstrated their relevance on several toxicity
prediction and structure-activity relationship problems.


title: Zero-Mode Contribution in Nucleon-Delta Transition

abstract:
  We investigate the transition form factors between nucleon and $\Delta$(1232)
particles by using a covariant quark-spectator-diquark field theory model in
(3+1) dimensions. Performing a light-front calculation in parallel with the
manifestly covariant calculation in light-front helicity basis, we examine the
light-front zero-mode contribution to the helicity components of light-front
good ("+") current matrix elements. Choosing the light-front gauge
($\epsilon^+_{h=\pm}=0$) with circular polarization in Drell-Yan-West frame, we
find that only the helicity components $({1\over 2}, {1\over 2})$ and $({1\over
2},-{1\over 2})$ of the good current receive the zero-mode contribution. Taking
into account the zero-mode, we find the prescription independence in obtaining
the light-front solution of form factors from any three helicity matrix
elements with smeared light-front wavefunctions. The angular condition, which
guarantees the full covariance of different schemes, is recovered.


title: K-minus Estimator Approach to Large Scale Structure

abstract:
  Self similar 3D distributions of point-particles, with a given quasifractal
dimension D, were generated on a Menger sponge model and then compared with
\textit{2dfGRS} and \textit{Virgo project} data
\footnote{http://www.mso.anu.edu.au/2dFGRS/,
http://www.mpa-garching.mpg.de/Virgo/}. Using the principle of local knowledge,
it is argued that in a finite volume of space only the two-point minus
estimator is acceptable in the correlation analysis of self similar spatial
distributions. In this sense, we have simplified the Pietronero-Labini
correlative analysis by defining a K-minus estimator, which when applied to
2dfGRS data revealed the quasifractal dimension $D\approx 2$ as expected. In
our approach the K-minus estimator is used only locally. Dimensions between D =
1 and D = 1.7, as suggested by the standard $\xi (r)$ analysis, were found to
be fallacy of the method. In order to visualize spatial quasifractal objects,
we created a small software program called \textit{RoPo} (''Rotate Points'').
This program illustrates and manifests local correlative analysis in which the
visual inspection emerged as a first step and a key part of the method.
Finally, we discuss importance and perspective of the visual inspection on
available real and simulated distributions. It is also argued that results of
contemporary cosmological simulations do not faithfully represent real data, as
they show a formation of ever increasing collapsars. We consent that 2dfGRS
data are reminiscent of some kind of underlying turbulence like effects in
action.


title: HTL approach to the viscosity of quark plasma

abstract:
  The quark viscosity in the quark gluon plasma is evaluated in HTL
approximation. The different contributions to the viscosity arising from the
various components of the quark spectral function are discussed. The
calculation is extended to finite values of the chemical potential.


title:
Convergence rates for Bayesian density estimation of
  infinite-dimensional exponential families

abstract:
  We study the rate of convergence of posterior distributions in density
estimation problems for log-densities in periodic Sobolev classes characterized
by a smoothness parameter p. The posterior expected density provides a
nonparametric estimation procedure attaining the optimal minimax rate of
convergence under Hellinger loss if the posterior distribution achieves the
optimal rate over certain uniformity classes. A prior on the density class of
interest is induced by a prior on the coefficients of the trigonometric series
expansion of the log-density. We show that when p is known, the posterior
distribution of a Gaussian prior achieves the optimal rate provided the prior
variances die off sufficiently rapidly. For a mixture of normal distributions,
the mixing weights on the dimension of the exponential family are assumed to be
bounded below by an exponentially decreasing sequence. To avoid the use of
infinite bases, we develop priors that cut off the series at a
sample-size-dependent truncation point. When the degree of smoothness is
unknown, a finite mixture of normal priors indexed by the smoothness parameter,
which is also assigned a prior, produces the best rate. A rate-adaptive
estimator is derived.


title: Extreme statistics of complex random and quantum chaotic states

abstract:
  An exact analytical description of extreme intensity statistics in complex
random states is derived. These states have the statistical properties of the
Gaussian and Circular Unitary Ensemble eigenstates of random matrix theory.
Although the components are correlated by the normalization constraint, it is
still possible to derive compact formulae for all values of the dimensionality
N. The maximum intensity result slowly approaches the Gumbel distribution even
though the variables are bounded, whereas the minimum intensity result rapidly
approaches the Weibull distribution. Since random matrix theory is conjectured
to be applicable to chaotic quantum systems, we calculate the extreme
eigenfunction statistics for the standard map with parameters at which its
classical map is fully chaotic. The statistical behaviors are consistent with
the finite-N formulae.


title: Asymptotically minimax Bayes predictive densities

abstract:
  Given a random sample from a distribution with density function that depends
on an unknown parameter $\theta$, we are interested in accurately estimating
the true parametric density function at a future observation from the same
distribution. The asymptotic risk of Bayes predictive density estimates with
Kullback--Leibler loss function $D(f_{\theta}||{\hat{f}})=\int{f_{\theta}
\log{(f_{\theta}/ hat{f})}}$ is used to examine various ways of choosing prior
distributions; the principal type of choice studied is minimax. We seek
asymptotically least favorable predictive densities for which the corresponding
asymptotic risk is minimax. A result resembling Stein's paradox for estimating
normal means by the maximum likelihood holds for the uniform prior in the
multivariate location family case: when the dimensionality of the model is at
least three, the Jeffreys prior is minimax, though inadmissible. The Jeffreys
prior is both admissible and minimax for one- and two-dimensional location
problems.


title:
Theoretical gravitational lensing. Beyond the weak-field small-angle
  approximation

abstract:
  An overview is given on those theoretical gravitational lensing results that
can be formulated in a spacetime setting, without assuming that the
gravitational fields are weak and that the bending angles are small. The first
part is devoted to analytical methods considering spacetimes in which the
equations for light rays (lightlike geodesics) is completely integrable. This
includes spherically symmetric static spacetimes, the Kerr spacetime and plane
gravitational waves. The second part is devoted to qualitative methods which
give some information on lensing properties without actually solving the
equation for lightlike geodesics. This includes Morse theory, methods from
differential topology and bifurcation theory.


title:
Crystal Structure and Physical Properties of Mg6Cu16Si7-type M6Ni16Si7,
  for M = Mg, Sc, Ti, Nb, and Ta

abstract:
  Five compounds were investigated for magnetic character and
superconductivity, all with non-magnetic nickel and band structures containing
flat bands and steep bands. The syntheses and crystal structures, refined by
powder X-ray diffraction, are reported for M6Ni16Si7, where M = Mg, Sc, Ti, Nb,
and Ta. All compounds form in the Mg6Cu16Si7 structure type. Resistance
measurements are also reported on M6Ni16Si7 (M = Mg, Sc, Ti, and Nb) down to
0.3 K, with all four showing metallic conductivity. No superconductivity is
observed. Magnetization measurements for all compounds reveal essentially
temperature independent paramagnetism, with a tendency toward more enhanced low
temperature paramagnetism for the cases of Mg6Ni16Si7 and Sc6Ni16Si7.


title: A Factorization Law for Entanglement Decay

abstract:
  We present a simple and general factorization law for quantum systems shared
by two parties, which describes the time evolution of entanglement upon passage
of either component through an arbitrary noisy channel. The robustness of
entanglement-based quantum information processing protocols is thus easily and
fully characterized by a single quantity.


title:
Post-ischaemic treatment with the cyclooxygenase-2 inhibitor nimesulide
  reduces blood-brain barrier disruption and leukocyte infiltration following
  transient focal cerebral ischaemia in rats

abstract:
  Several studies suggest that cyclooxygenase (COX)-2 plays a pivotal role in
the progression of ischaemic brain damage. In the present study, we
investigated the effects of selective inhibition of COX-2 with nimesulide (12
mg/kg) and selective inhibition of COX-1 with valeryl salicylate (VAS, 12-120
mg/kg) on prostaglandin E2 (PGE2) levels, myeloperoxidase (MPO) activity, Evans
blue (EB) extravasation and infarct volume in a standardized model of transient
focal cerebral ischaemia in the rat. Post-ischaemic treatment with nimesulide
markedly reduced the increase in PGE2 levels in the ischaemic cerebral cortex
24 h after stroke and diminished infarct size by 48% with respect to
vehicle-treated animals after 3 days of reperfusion. Furthermore, nimesulide
significantly attenuated the blood-brain barrier (BBB) damage and leukocyte
infiltration (as measured by EB leakage and MPO activity, respectively) seen at
48 h after the initial ischaemic episode. These studies provide the first
experimental evidence that COX-2 inhibition with nimesulide is able to limit
BBB disruption and leukocyte infiltration following transient focal cerebral
ischaemia. Neuroprotection afforded by nimesulide is observed even when the
treatment is delayed until 6 h after the onset of ischaemia, confirming a wide
therapeutic window of COX-2 inhibitors in experimental stroke. On the contrary,
selective inhibition of COX-1 with VAS had no significant effect on the
evaluated parameters. These data suggest that COX-2 activity, but not COX-1
activity, contributes to the progression of focal ischaemic brain injury, and
that the beneficial effects observed with non-selective COX inhibitors are
probably associated to COX-2 rather than to COX-1 inhibition.


title: Search for b--> u transitions in B- -> [K+pi-pi0]_D K-

abstract:
  We search for decays of a B meson into a neutral D meson and a kaon, with the
D meson decaying into K+pi-pi0. This final state can be reached through the b
--> c transition B- -> D0K- followed by the doubly Cabibbo-suppressed D0 -->
K+pi-pi0, or the b --> u transition B- --> D0bar K- followed by the
Cabibbo-favored D0bar --> K+ pi-pi 0. The interference of these two amplitudes
is sensitive to the angle gamma of the unitarity triangle. We present
preliminary results based on 226 10^{6} e+e- --> Y(4s) --> BBbar events
collected with the BABAR detector at SLAC. We find no significant evidence for
these decays and we set a limit R_ADS =(BR(B- -->[K+pi-pi0]_D K-)+ BR(B+ -->
[K-pi+pi0]_D K+))/(BR(B- -->[K-p i+pi0]_D K-)+ BR(B+ --> [K+pi-pi0]_D
K+))<0.039 at 95% confidence level, which we translate with a Bayesian approach
into r_B = |A(B- --> D0bar K-)|/|A(B- --> D0bar K-)| < 0.185 at 95% confidence
level.


title:
First-principles thermal equation of state and thermoelasticity for hcp
  Fe under high pressures

abstract:
  We investigate the equation of state and elastic properties of nonmagnetic
hcp iron at high pressures and high temperatures using the first principles
linear response linear-muffin-tin-orbital method in the generalized-gradient
approximation. We calculate the Helmholtz free energy as a function of volume,
temperature, and volume-constrained strain, including the electronic excitation
contributions from band structures and lattice vibrational contributions from
quasi-harmonic lattice dynamics. We perform detailed investigations on the
behavior of elastic moduli and equation of state properties as a function of
temperature and pressure, including the pressure-volume equation of state, bulk
modulus, the thermal expansion coefficient, the Gruneisen ratio, and the shock
Hugoniots. A detailed comparison has been made with available experimental
measurements and theoretical predictions.


title: Non-stationary quantum walks on the cycle

abstract:
  We consider quantum walks on the cycle in the non-stationary case where the
`coin' operation is allowed to change at each time step. We characterize, in
algebraic terms, the set of possible state transfers and prove that, as opposed
to the stationary case, it is possible to asymnptotically reach a uniform
distribution among the nodes of the associated graph.


title: Semiparametric estimation of fractional cointegrating subspaces

abstract:
  We consider a common-components model for multivariate fractional
cointegration, in which the $s\geq1$ components have different memory
parameters. The cointegrating rank may exceed 1. We decompose the true
cointegrating vectors into orthogonal fractional cointegrating subspaces such
that vectors from distinct subspaces yield cointegrating errors with distinct
memory parameters. We estimate each cointegrating subspace separately, using
appropriate sets of eigenvectors of an averaged periodogram matrix of tapered,
differenced observations, based on the first $m$ Fourier frequencies, with $m$
fixed. The angle between the true and estimated cointegrating subspaces is
$o_p(1)$. We use the cointegrating residuals corresponding to an estimated
cointegrating vector to obtain a consistent and asymptotically normal estimate
of the memory parameter for the given cointegrating subspace, using a
univariate Gaussian semiparametric estimator with a bandwidth that tends to
$\infty$ more slowly than $n$. We use these estimates to test for fractional
cointegration and to consistently identify the cointegrating subspaces.


title:
Regional distribution of the prostaglandin E2 receptor EP1 in the rat
  brain: accumulation in Purkinje cells of the cerebellum

abstract:
  Prostaglandin E2 (PGE2), is a major prostanoid produced by the activity of
cyclooxygenases (COX) in response to various physiological and pathological
stimuli. PGE2 exerts its effects by activating four specific E-type prostanoid
receptors (EP1, EP2, EP3, and EP4). In the present study, we analyzed the
expression of the PGE2 receptor EP1 (mRNA and protein) in different regions of
the adult rat brain (hippocampus, hypothalamus, striatum, prefrontal cerebral
cortex, parietal cortex, brain stem, and cerebellum) using reverse
transcription- polymerase chain reaction, Western blotting, and
immunohistochemical methods. On a regional basis, levels of EP1 mRNA were the
highest in parietal cortex and cerebellum. At the protein level, we found very
strong expression of EP1 in cerebellum, as revealed by Western blotting
experiments. Furthermore, the present study provides for the first time
evidence that the EP1 receptor is highly expressed in the cerebellum, where the
Purkinje cells displayed very high immunolabeling of their perikaryon and
dendrites, as observed in the immunohistochemical analysis. Results from the
present study indicate that the EP1 prostanoid receptor is expressed in
specific neuronal populations, which possibly determine the region-specific
response to PGE2.


title:
Wide therapeutic time window for nimesulide neuroprotection in a model
  of transient focal cerebral ischemia in the rat

abstract:
  Results from several studies indicate that cyclooxygenase-2 (COX-2) is
involved in ischemic brain injury. The purpose of this study was to evaluate
the neuroprotective effects of the selective COX-2 inhibitor nimesulide on
cerebral infarction and neurological deficits in a standardized model of
transient focal cerebral ischemia in rats. Three doses of nimesulide (3, 6 and
12 mg/kg; i.p.) or vehicle were administered immediately after stroke and
additional doses were given at 6, 12, 24, 36 and 48 h after ischemia. In other
set of experiments, the effect of nimesulide was studied in a situation in
which its first administration was delayed for 3-24 h after ischemia. Total,
cortical and subcortical infarct volumes and functional outcome (assessed by
neurological deficit score and rotarod performance) were determined 3 days
after ischemia. The effect of nimesulide on prostaglandin E(2) (PGE(2)) levels
in the injured brain was also investigated. Nimesulide dose-dependently reduced
infarct volume and improved functional recovery when compared to vehicle. Of
interest is the finding that neuroprotection conferred by nimesulide (reduction
of infarct size and neurological deficits and improvement of rotarod
performance) was also observed when treatment was delayed until 24 h after
ischemia. Further, administration of nimesulide in a delayed treatment paradigm
completely abolished PGE(2) accumulation in the postischemic brain, suggesting
that COX-2 inhibition is a promising therapeutic strategy for cerebral ischemia
to target the late-occurring inflammatory events which amplify initial damage.


title:
First principles investigations of the electronic, magnetic and chemical
  bonding properties of CeTSn (T=Rh,Ru)

abstract:
  The electronic structures of CeRhSn and CeRuSn are self-consistently
calculated within density functional theory using the local spin density
approximation for exchange and correlation. In agreement with experimental
findings, the analyses of the electronic structures and of the chemical bonding
properties point to the absence of magnetization within the mixed valent Rh
based system while a finite magnetic moment is observed for trivalent cerium
within the Ru-based stannide, which contains both trivalent and intermediate
valent Ce.


title: Pulsar model of the high energy phenomenology of LS 5039

abstract:
  Under the assumption that LS 5039 is a system composed by a pulsar rotating
around an O6.5V star in a $\sim 3.9$ day orbit, we present the results of a
theoretical modeling of the high energy phenomenology observed by the High
Energy Stereoscopy Array (H.E.S.S.). This model (including detailed account of
the system geometry, Klein-Nishina inverse Compton, $\gamma$-$\gamma$
absorption, and cascading) is able to describe well the rich observed
phenomenology found in the system at all timescales, both flux and
spectrum-wise.


title: GD 99 - an unusual, rarely observed DAV white dwarf

abstract:
  New observations of GD 99 are analysed. The unusual pulsation behaviour,
showing both long and short periods, has been confirmed. All the available
periods show a grouping of short and long period modes with roughly regular
spacing. If we interpret the groups separately, a binary nature can be a
possible explanation as in the similar cases of WD 2350-0054 and G29-38.


title:
Engineering exotic phases for topologically-protected quantum
  computation by emulating quantum dimer models

abstract:
  We use a nonperturbative extended contractor renormalization (ENCORE) method
for engineering quantum devices for the implementation of topologically
protected quantum bits described by an effective quantum dimer model on the
triangular lattice. By tuning the couplings of the device, topological
protection might be achieved if the ratio between effective two-dimer
interactions and flip amplitudes lies in the liquid phase of the phase diagram
of the quantum dimer model. For a proposal based on a quantum Josephson
junction array [L. B. Ioffe {\it et al.}, Nature (London) {\bf 415}, 503
(2002)] our results show that optimal operational temperatures below 1 mK can
only be obtained if extra interactions and dimer flips, which are not present
in the standard quantum dimer model and involve three or four dimers, are
included. It is unclear if these extra terms in the quantum dimer Hamiltonian
destroy the liquid phase needed for quantum computation. Minimizing the effects
of multi-dimer terms would require energy scales in the nano-Kelvin regime. An
alternative implementation based on cold atomic or molecular gases loaded into
optical lattices is also discussed, and it is shown that the small energy
scales involved--implying long operational times--make such a device
impractical. Given the many orders of magnitude between bare couplings in
devices, and the topological gap, the realization of topological phases in
quantum devices requires careful engineering and large bare interaction scales.


title:
Motion by Stopping: Rectifying Brownian Motion of Non-spherical
  Particles

abstract:
  We show that Brownian motion is spatially not symmetric for mesoscopic
particles embedded in a fluid if the particle is not in thermal equilibrium and
its shape is not spherical. In view of applications on molecular motors in
biological cells, we sustain non-equilibrium by stopping a non-spherical
particle at periodic sites along a filament. Molecular dynamics simulations in
a Lennard-Jones fluid demonstrate that directed motion is possible without a
ratchet potential or temperature gradients if the asymmetric non-equilibrium
relaxation process is hindered by external stopping. Analytic calculations in
the ideal gas limit show that motion even against a fluid drift is possible and
that the direction of motion can be controlled by the shape of the particle,
which is completely characterized by tensorial Minkowski functionals.


title: UV excess and AGB evolution in elliptical-galaxy stellar populations

abstract:
  The puzzling origin of the ``UV-upturn'' phenomenon, observed in some
elliptical galaxies, has recently been settled by identifying hot HB stars as
main contributors to galaxy ultraviolet luminosity excess. While a blue HB
morphology seems a natural characteristic of metal-poor stellar populations,
its appearence in metal-rich systems, often coupled with a poorer rate of
planetary nebulae per unit galaxy luminosity, might be calling for an intimate
connection between UV excess and AGB properties in early-type galaxies. In this
work, we want to briefly assess this issue, relying on infrared surface
brightness fluctuations as a powerful tool to trace AGB properties in external
galaxies with unresolved stellar populations.


title: Isomer triggering via nuclear excitation by electron capture

abstract:
  Triggering of long-lived nuclear isomeric states via coupling to the atomic
shells in the process of nuclear excitation by electron capture (NEEC) is
studied. NEEC occurring in highly-charged ions can excite the isomeric state to
a triggering level that subsequently decays to the ground state. We present
total cross sections for NEEC isomer triggering considering experimentally
confirmed low-lying triggering levels and reaction rates based on realistic
experimental parameters in ion storage rings. A comparison with other isomer
triggering mechanisms shows that, among these, NEEC is the most efficient.


title: Accurate seeing measurements with MASS and DIMM

abstract:
  Astronomical seeing is quantified by a single parameter, turbulence integral,
in the framework of the Kolmogorov turbulence model. This parameter can be
routinely measured by a Differential Image Motion Monitor, DIMM. A new
instrument, Multi-Aperture Scintillation Sensor (MASS), permits to measure the
seeing in the free atmosphere above ~0.5km and, together with a DIMM, to
estimate the ground-layer seeing. The absolute accuracy of both methods is
studied here using analytical theory, numerical simulation, and experiments. A
modification of the MASS data processing to compensate for partially saturated
scintillation is developed. We find that the DIMM can be severely biased by
optical aberrations (e.g. defocus) and propagation. Seeing measurements with
DIMM and MASS can reach absolute accuracy of ~10% when their biases are
carefully controlled. Pushing this limit to 1% appears unrealistic because the
seeing itself is just a model-dependent parameter of a non-stationary random
process.


title: More frequencies of KUV 02464+3239

abstract:
  Preliminary results on KUV 02464+3239, a pulsating DA white dwarf are
presented. Located near the red edge of the DAV instability strip, KUV
02464+3239 shows large amplitude and long period pulsation modes. Up to now
only one mode was known from a 50-minute-long light curve. Our more extended
observations allowed the identification of three additional frequencies. The
presence of previously known harmonics were confirmed and weak subharmonics are
also noticeable at some parts of the light curve. This suggests the dominance
of nonlinear pulsation effects from time to time.


title:
A frequency domain empirical likelihood for short- and long-range
  dependence

abstract:
  This paper introduces a version of empirical likelihood based on the
periodogram and spectral estimating equations. This formulation handles
dependent data through a data transformation (i.e., a Fourier transform) and is
developed in terms of the spectral distribution rather than a time domain
probability distribution. The asymptotic properties of frequency domain
empirical likelihood are studied for linear time processes exhibiting both
short- and long-range dependence. The method results in likelihood ratios which
can be used to build nonparametric, asymptotically correct confidence regions
for a class of normalized (or ratio) spectral parameters, including
autocorrelations. Maximum empirical likelihood estimators are possible, as well
as tests of spectral moment conditions. The methodology can be applied to
several inference problems such as Whittle estimation and goodness-of-fit
testing.


title: The Chemical Composition of an Extrasolar Minor Planet

abstract:
  We report the relative abundances of 17 elements in the atmosphere of the
white dwarf star GD 362, material that, very probably, was contained previously
in a large asteroid or asteroids with composition similar to the Earth/Moon
system. The asteroid may have once been part of a larger parent body not unlike
one of the terrestrial planets of our solar system.


title:
$\Lambda NN$ and $\Sigma NN$ systems at threshold: II. The effect of D
  waves

abstract:
  Using the two-body interactions obtained from a chiral constituent quark
model we study all $\Lambda NN$ and $\Sigma NN$ states with I=0,1,2 and
J=1/2,3/2 at threshold, taking into account all three-body configurations with
S and D wave components. We constrain further the limits for the $\Lambda N$
spin-triplet scattering length a_{1/2,1}. Using the hypertriton binding energy
we find a narrow interval for the possible values of the $\Lambda N$
spin-singlet scattering length a_{1/2,0}. We found that the $\Sigma NN$ system
has a quasibound state in the (I,J) = (1,1/2) channel very near threshold with
a width of about 2.1 MeV.


title: A Note on Shortest Developments

abstract:
  De Vrijer has presented a proof of the finite developments theorem which, in
addition to showing that all developments are finite, gives an effective
reduction strategy computing longest developments as well as a simple formula
computing their length.
  We show that by applying a rather simple and intuitive principle of duality
to de Vrijer's approach one arrives at a proof that some developments are
finite which in addition yields an effective reduction strategy computing
shortest developments as well as a simple formula computing their length. The
duality fails for general beta-reduction.
  Our results simplify previous work by Khasidashvili.


title:
Four-wave mixing, quantum control and compensating losses in doped
  negative-index photonic metamaterials

abstract:
  The possibility of compensating absorption in negative-index metatamterials
(NIMs) doped by resonant nonlinear-optical centers is shown. The role of
quantum interference and extraordinary properties of four-wave parametric
amplification of counter-propagating electromagnetic waves in NIMs are
discussed.


title: Regular spanning subgraphs of bipartite graphs of high minimum degree

abstract:
  Let G be a simple balanced bipartite graph on $2n$ vertices, $\delta =
\delta(G)/n$, and $\rho={\delta + \sqrt{2 \delta -1} \over 2}$. If $\delta >
1/2$ then it has a $\lfloor \rho n \rfloor$-regular spanning subgraph. The
statement is nearly tight.


title: The end of the Galactic spectrum

abstract:
  We use a diffusion galactic model to analyze the end of the Galactic cosmic
ray spectrum and its mixing with the extragalactic cosmic ray flux. We analyze
the transition between Galactic and extragalactic components using two
different extragalactic models. We compare the sum of the diffusive galactic
spectrum and extragalactic spectrum with the available experimental data.


title: Phase diagram and magnetocaloric effect of CoMnGe_{1-x}Sn_{x} alloys

abstract:
  We propose the phase diagram of a new pseudo-ternary compound,
CoMnGe_{1-x}Sn_{x}, in the range x less than or equal to 0.1. Our phase diagram
is a result of magnetic and calometric measurements. We demonstrate the
appearance of a hysteretic magnetostructural phase transition in the range
x=0.04 to x=0.055, similar to that observed in CoMnGe under hydrostatic
pressure. From magnetisation measurements, we show that the isothermal entropy
change associated with the magnetostructural transition can be as high as 4.5
J/(K kg) in a field of 1 Tesla. However, the large thermal hysteresis in this
transition (~20 K) will limit its straightforward use in a magnetocaloric
device.


title: Proximity DC squids in the long junction limit

abstract:
  We report the design and measurement of
Superconducting/normal/superconducting (SNS) proximity DC squids in the long
junction limit, i.e. superconducting loops interrupted by two normal metal
wires roughly a micrometer long. Thanks to the clean interface between the
metals, at low temperature a large supercurrent flows through the device. The
dc squid-like geometry leads to an almost complete periodic modulation of the
critical current through the device by a magnetic flux, with a flux periodicity
of a flux quantum h/2e through the SNS loop. In addition, we examine the entire
field dependence, notably the low and high field dependence of the maximum
switching current. In contrast with the well-known Fraunhoffer-type
oscillations typical of short wide junctions, we find a monotonous gaussian
extinction of the critical current at high field. As shown in [15], this
monotonous dependence is typical of long and narrow diffusive junctions. We
also find in some cases a puzzling reentrance at low field. In contrast, the
temperature dependence of the critical current is well described by the
proximity effect theory, as found by Dubos {\it et al.} [16] on SNS wires in
the long junction limit. The switching current distributions and hysteretic IV
curves also suggest interesting dynamics of long SNS junctions with an
important role played by the diffusion time across the junction.


title: Algebraic K-theory and abstract homotopy theory

abstract:
  We decompose the K-theory space of a Waldhausen category in terms of its
Dwyer-Kan simplicial localization. This leads to a criterion for functors to
induce equivalences of K-theory spectra that generalizes and explains many of
the criteria appearing in the literature. We show that under mild hypotheses, a
weakly exact functor that induces an equivalence of homotopy categories induces
an equivalence of K-theory spectra.


title:
Restless pions: orbifold boundary conditions and noise suppression in
  lattice QCD

abstract:
  The study of one or more baryons in lattice QCD is severely hindered by the
exponential decay in time of the signal-to-noise ratio. The rate at which the
signal-to-noise decreases is a function of the the pion mass. More precisely,
it depends on the minimum allowed pion energy in the box, which, for periodic
boundary conditions, is equal to its mass. We propose a set of boundary
conditions, given by a "parity orbifold'' construction, which eliminates the
zero momentum pion modes, raising the minimum pion energy without altering the
QCD ground state, and thereby improving the signal-to-noise ratio of
(multi)-baryon correlation functions at long Euclidean times. We discuss
variations of these "restless pions" boundary conditions and focus on their
impact on the study of nuclear forces.


title: Collective oscillations in optical matter

abstract:
  Atom and nanoparticle arrays trapped in optical lattices are shown to be
capable of sustaining collective oscillations of frequency proportional to the
strength of the external light field. The spectrum of these oscillations
determines the mechanical stability of the arrays. This phenomenon is studied
for dimers, strings, and two-dimensional planar arrays. Laterally confined
particles free to move along an optical channel are also considered as an
example of collective motion in partially-confined systems. The fundamental
concepts of dynamical response in optical matter introduced here constitute the
basis for potential applications to quantum information technology and signal
processing. Experimental realizations of these systems are proposed.


title: Models of Financial Markets with Extensive Participation Incentives

abstract:
  We consider models of financial markets in which all parties involved find
incentives to participate. Strategies are evaluated directly by their virtual
wealths. By tuning the price sensitivity and market impact, a phase diagram
with several attractor behaviors resembling those of real markets emerge,
reflecting the roles played by the arbitrageurs and trendsetters, and including
a phase with irregular price trends and positive sums. The positive-sumness of
the players' wealths provides participation incentives for them. Evolution and
the bid-ask spread provide mechanisms for the gain in wealth of both the
players and market-makers. New players survive in the market if the
evolutionary rate is sufficiently slow. We test the applicability of the model
on real Hang Seng Index data over 20 years. Comparisons with other models show
that our model has a superior average performance when applied to real
financial data.


title:
Triangulated categories of matrix factorizations for regular systems of
  weights with $\epsilon=-1$

abstract:
  We construct a full strongly exceptional collection in the triangulated
category of graded matrix factorizations of a polynomial associated to a
non-degenerate regular system of weights whose smallest exponents are equal to
-1. In the associated Grothendieck group, the strongly exceptional collection
defines a root basis of a generalized root system of sign (l,0,2) and a Coxeter
element of finite order, whose primitive eigenvector is a regular element in
the expanded symmetric domain of type IV with respect to the Weyl group.


title:
The long-term evolution of the spin, pulse shape, and orbit of the
  accretion-powered millisecond pulsar SAX J1808.4-3658

abstract:
  We present a 7 yr timing study of the 2.5 ms X-ray pulsar SAX J1808.4-3658,
an X-ray transient with a recurrence time of ~2 yr, using data from the Rossi
X-ray Timing Explorer covering 4 transient outbursts (1998-2005). We verify
that the 401 Hz pulsation traces the spin frequency fundamental and not a
harmonic. Substantial pulse shape variability, both stochastic and systematic,
was observed during each outburst. Analysis of the systematic pulse shape
changes suggests that, as an outburst dims, the X-ray "hot spot" on the pulsar
surface drifts longitudinally and a second hot spot may appear. The overall
pulse shape variability limits the ability to measure spin frequency evolution
within a given X-ray outburst (and calls previous nudot measurements of this
source into question), with typical upper limits of |nudot| < 2.5x10^{-14} Hz/s
(2 sigma). However, combining data from all the outbursts shows with high (6
sigma) significance that the pulsar is undergoing long-term spin down at a rate
nudot = (-5.6+/-2.0)x10^{-16} Hz/s, with most of the spin evolution occurring
during X-ray quiescence. We discuss the possible contributions of magnetic
propeller torques, magnetic dipole radiation, and gravitational radiation to
the measured spin down, setting an upper limit of B < 1.5x10^8 G for the
pulsar's surface dipole magnetic field and and Q/I < 5x10^{-9} for the
fractional mass quadrupole moment. We also measured an orbital period
derivative of Pdot = (3.5+/-0.2)x10^{-12} s/s. This surprising large Pdot is
reminiscent of the large and quasi-cyclic orbital period variation observed in
the so-called "black widow" millisecond radio pulsars, supporting speculation
that SAX J1808.4-3658 may turn on as a radio pulsar during quiescence. In an
appendix we derive an improved (0.15 arcsec) source position from optical data.


title: Bosonization of strongly interacting electrons

abstract:
  Strong repulsive interactions in a one-dimensional electron system suppress
the exchange coupling J of electron spins to a value much smaller than the
Fermi energy E_F. The conventional theoretical description of such systems
based on the bosonization approach and the concept of Tomonaga-Luttinger liquid
is applicable only at energies below J. In this paper we develop a theoretical
approach valid at all energies below the Fermi energy, including a broad range
of energies between J and E_F. The method involves bosonization of the charge
degrees of freedom, while the spin excitations are treated exactly. We use this
technique to calculate the spectral functions of strongly interacting electron
systems at energies in the range J<<epsilon<< E_F$. We show that in addition to
the expected features at the wavevector k near the Fermi point k_F, the
spectral function has a strong peak centered at k=0. Our theory also provides
analytical description of the spectral function singularities near 3k_F (the
"shadow band" features).


title: Permutations of Strongly Self-Absorbing C*-algebras

abstract:
  Let G be a finite group acting on {1,...,n}. For any C*-algebra A, this
defines an action of \alpha of G on A^{\otimes n}. We show that if A
tensorially absorbs a UHF algebra of infinite type, the Jiang-Su algebra, or is
approximately divisible, then A \times_{\alpha} G has the corresponding
property as well.


title:
Helioseismic Holography of Simulated Solar Convection and Prospects for
  the Detection of Small-Scale Subsurface Flows

abstract:
  We perform helioseismic holography on realistic solar convection simulations
and compare the observed travel-time perturbations with the expected travel
times from the horizontal flows in the simulations computed from forward models
under the assumption of the Born approximation. We demonstrate reasonable
agreement between the observed and model travel times which reinforces the
validity of helioseismic holography in the detection of subsurface horizontal
flows. From the variation of the signal-to-noise ratio with depth, we conclude
that the helioseismic detection of individual flow structures with spatial
scales of supergranulation or smaller is not possible for depths below about 5
Mm below the surface over time scales less than a day. Approximately half of
the observed signal originates within the first 2 Mm below the surface. A
consequence of this is a rapid decrease (and reversal in some cases) of the
travel-time perturbations with depth due to the contribution to the
measurements of oppositely directed surface flows in neighboring convective
cells. This confirms an earlier interpretation of similar effects reported from
observations.


title:
Comments on the Invariance of Physical Laws Under Particle
  Re-Arrangement

abstract:
  Observationally and experimentally, physical laws express how particles
interact. Conversely, physical laws should be invariant under any
re-arrangement of those particles, e.g., the laws of gravity do not change if
one re-arranges the stars in the sky. To explore the physical meaning of these
assertions, arguments are presented that show how the freedom of particle
re-arrangement leads to an identical twin associated with any photon, i.e.,
nature sees double. These twins can become spatially separated for
astronomically distant objects and are special in that detection of the one
causes the disappearance of the other. A tilting detector then leads to
brightness variations across an image for twin separations on the order of the
detector size.


title: Modulation effects on Landau levels in a monolayer graphene

abstract:
  A monolayer graphene exists in an environment where a uniform magnetic field
interacts a spatially modulated magnetic field. The spatially modulated
magnetic field could affect Landau levels due to a uniform magnetic field. The
modulation effects on Landau levels are investigated through the Peierl's
tight-binding model. The magneto-electronic properties are dominated by the
period, the strength, and the direction of a spatially modulated magnetic
field. Such a field could induce the growth in dimensionality, the change of
energy dispersions, the destroy of state degeneracy, and the creation of
band-edge states. There are a robust Landau level at Fermi level and 1D
parabolic subbands located around the original Landau levels, which make
density of states exhibit a delta-function-like structure and many pairs of
asymmetric peak structure, respectively. The density of states and the energies
of band-edge states strongly depend on the strength, but not on the period and
the direction.


title:
Impurity induced density of states and residual transport in nonunitary
  superconductors

abstract:
  We obtain general expressions for the residual density of states, electrical
conductivity and thermal conductivity for non-unitary superconductors due to
impurity scattering. We apply the results to the so-called `B phase' of
PrOs4Sb12, which we describe using a non-unitary gap function derived from
symmetry considerations. The conductivity tensor has inequivalent diagonal
components due to off-axis nodal positions which may be detectable in
experiments.