title:
Finite temperature spectral function of a hole in a quantum
  antiferromagnet and role of phonons

abstract:
  We study thermal broadening of the hole spectral function of the
two-dimensional t-J model (and its extensions) within the non-crossing
approximation with and without the contribution of optical phonons. We find
that phonons at finite temperature broaden the lowest energy quasiparticle
peak, however, the string excitations survive even for relatively strong
electron-phonon coupling. Experimental angle resolved photo-emission
spectroscopy(ARPES) results compare well with our calculations at finite
temperature when we use strong electron-phonon coupling without any adhoc
broadening. In addition, we have studied the role of vertex corrections and we
find that their contribution allows us achieve the same overall agreement with
the ARPES experimental results but using smaller values for the electron-phonon
coupling.


title: Protostellar Outflow Evolution in Turbulent Environments

abstract:
  The link between turbulence in star formatting environments and protostellar
jets remains controversial. To explore issues of turbulence and fossil cavities
driven by young stellar outflows we present a series of numerical simulations
tracking the evolution of transient protostellar jets driven into a turbulent
medium. Our simulations show both the effect of turbulence on outflow
structures and, conversely, the effect of outflows on the ambient turbulence.
We demonstrate how turbulence will lead to strong modifications in jet
morphology. More importantly, we demonstrate that individual transient outflows
have the capacity to re-energize decaying turbulence. Our simulations support a
scenario in which the directed energy/momentum associated with cavities is
randomized as the cavities are disrupted by dynamical instabilities seeded by
the ambient turbulence. Consideration of the energy power spectra of the
simulations reveals that the disruption of the cavities powers an energy
cascade consistent with Burgers'-type turbulence and produces a driving
scale-length associated with the cavity propagation length. We conclude that
fossil cavities interacting either with a turbulent medium or with other
cavities have the capacity to sustain or create turbulent flows in star forming
environments. In the last section we contrast our work and its conclusions with
previous studies which claim that jets can not be the source of turbulence.


title:
Mean curvature one surfaces in hyperbolic space, and their relationship
  to minimal surfaces in Euclidean space

abstract:
  We describe local similarities and global differences between minimal
surfaces in Euclidean 3-space and constant mean curvature 1 surfaces in
hyperbolic 3-space. We also describe how to solve global period problems for
constant mean curvature 1 surfaces in hyperbolic 3-space, and we give an
overview of recent results on these surfaces. We include computer graphics of a
number of examples.


title: Gravitation, C, P and T symmetries and the Second Law

abstract:
  The intimate links between gravitation and the second law are summarized and
two less known relations between gravity and thermodynamics are studied.
Firstly, the information cost required to operate a Maxwell's demon on a curved
spacetime is estimated using the Kolmogorov-Sinai entropy. More importantly,
the charge and time (C and T) reversal properties of the Kerr-Newman solution
in General relativity show that this solution, similarly to the Dirac equation,
appears to represent both a particle and its antiparticle and suggests a
definition of antimatter in general relativity. This definition leads to a
parameter free explanation of the cosmological constant term observed in the
supernovae data. The relation of this definition of antimatter with the coupled
systems through opposite time arrows studied by Schulman is also emphasized.


title: Minimal surfaces with planar boundary curves

abstract:
  We consider compact connected minimal surfaces, with a pair of boundary
curves (not necessarily convex) in distinct planes, that have least-area
amongst all orientable surfaces with the same boundary. When the planes
containing these two boundary curves are either parallel or sufficiently close
to parallel, and when the boundary curves themselves are sufficiently close to
each other, we draw specific conclusions about the geometry and topology of the
surfaces. We also strength the following result: Let $M$ be any compact minimal
annulus with two planar boundary curves of diameters $d_1$ and $d_2$ in
parallel planes $P_1$ and $P_2$; if the distance between $P_1$ and $P_2$ is
$h$, then the inequality $h \leq {3/2}\max\{d_1,d_2\}$ is satisfied. We
strength it by removing the assumption that $M$ is an annulus and by showing
that the stronger conclusion $h \leq \max\{d_1,d_2\}$ holds. We also include a
similar result for nonminimal constant mean curvature surfaces.


title:
Magnetically Regulated Star Formation in 3D: The Case of Taurus
  Molecular Cloud Complex

abstract:
  We carry out three-dimensional MHD simulations of star formation in
turbulent, magnetized clouds, including ambipolar diffusion and feedback from
protostellar outflows. The calculations focus on relatively diffuse clouds
threaded by a strong magnetic field capable of resisting severe tangling by
turbulent motions and retarding global gravitational contraction in the
cross-field direction. They are motivated by observations of the Taurus
molecular cloud complex (and, to a lesser extent, Pipe Nebula), which shows an
ordered large-scale magnetic field, as well as elongated condensations that are
generally perpendicular to the large-scale field. We find that stars form in
earnest in such clouds when enough material has settled gravitationally along
the field lines that the mass-to-flux ratios of the condensations approach the
critical value. Only a small fraction (of order 1% or less) of the nearly
magnetically-critical, condensed material is turned into stars per local
free-fall time, however. The slow star formation takes place in condensations
that are moderately supersonic; it is regulated primarily by magnetic fields,
rather than turbulence. The quiescent condensations are surrounded by diffuse
halos that are much more turbulent, as observed in the Taurus complex. Strong
support for magnetic regulation of star formation in this complex comes from
the extremely slow conversion of the already condensed, relatively quiescent
C$^{18}$O gas into stars, at a rate two orders of magnitude below the maximum,
free-fall value. We analyze the properties of dense cores, including their mass
spectrum, which resembles the stellar initial mass function.


title:
High-Dimensional Graphical Model Selection Using $\ell_1$-Regularized
  Logistic Regression

abstract:
  We consider the problem of estimating the graph structure associated with a
discrete Markov random field. We describe a method based on
$\ell_1$-regularized logistic regression, in which the neighborhood of any
given node is estimated by performing logistic regression subject to an
$\ell_1$-constraint. Our framework applies to the high-dimensional setting, in
which both the number of nodes $p$ and maximum neighborhood sizes $d$ are
allowed to grow as a function of the number of observations $n$. Our main
results provide sufficient conditions on the triple $(n, p, d)$ for the method
to succeed in consistently estimating the neighborhood of every node in the
graph simultaneously. Under certain assumptions on the population Fisher
information matrix, we prove that consistent neighborhood selection can be
obtained for sample sizes $n = \Omega(d^3 \log p)$, with the error decaying as
$\order(\exp(-C n/d^3))$ for some constant $C$. If these same assumptions are
imposed directly on the sample matrices, we show that $n = \Omega(d^2 \log p)$
samples are sufficient.


title: Minimal Surfaces with Catenoid Ends

abstract:
  In this paper, we use the conjugate surface construction to prove the
existence of certain non-periodic symmetric immersed minimal surfaces. These
surfaces have finite total curvature and embedded catenoid ends, and they have
positive genus yet maintain the symmetry of their genus-zero counterparts
constructed by Jorge-Meeks and Xu.


title:
Distance Distributions in Finite Uniformly Random Networks: Theory and
  Applications

abstract:
  In wireless networks, the knowledge of nodal distances is essential for
several areas such as system configuration, performance analysis and protocol
design. In order to evaluate distance distributions in random networks, the
underlying nodal arrangement is almost universally taken to be an infinite
Poisson point process. While this assumption is valid in some cases, there are
also certain impracticalities to this model. For example, practical networks
are non-stationary, and the number of nodes in disjoint areas are not
independent. This paper considers a more realistic network model where a finite
number of nodes are uniformly randomly distributed in a general d-dimensional
ball of radius R and characterizes the distribution of Euclidean distances in
the system. The key result is that the probability density function of the
distance from the center of the network to its nth nearest neighbor follows a
generalized beta distribution. This finding is applied to study network
characteristics such as energy consumption, interference, outage and
connectivity.


title: Minimal surfaces in $R^3$ with dihedral symmetry

abstract:
  We construct new examples of immersed minimal surfaces with catenoid ends and
finite total curvature, of both genus zero and higher genus. In the genus zero
case, we classify all such surfaces with at most $2n+1$ ends, and with symmetry
group the natural $\bfZ_2$ extension of the dihedral group $D_n$. The surfaces
are constructed by proving existence of the conjugate surfaces. We extend this
method to cases where the conjugate surface of the fundamental piece is
noncompact and is not a graph over a convex plane domain.


title: $2N$ qubit "mirror states" for optimal quantum communication

abstract:
  We introduce a new genuinely 2N qubit state, known as the "mirror state" with
interesting entanglement properties. The well known Bell and the cluster states
form a special case of these "mirror states", for N=1 and N=2 respectively. It
can be experimentally realized using $SWAP$ and multiply controlled phase shift
operations. After establishing the general conditions for a state to be useful
for various communicational protocols involving quantum and classical
information, it is shown that the present state can optimally implement
algorithms for the quantum teleportation of an arbitrary N qubit state and
achieve quantum information splitting in all possible ways. With regard to
superdense coding, one can send 2N classical bits by sending only N qubits and
consuming N ebits of entanglement. Explicit comparison of the mirror state with
the rearranged N Bell pairs and the linear cluster states is considered for
these quantum protocols. We also show that mirror states are more robust than
the rearranged Bell pairs with respect to a certain class of collisional
decoherence.


title: Unified Approach to Universal Cloning and Phase-Covariant Cloning

abstract:
  We analyze the problem of approximate quantum cloning when the quantum state
is between two latitudes on the Bloch's sphere. We present an analytical
formula for the optimized 1-to-2 cloning. The formula unifies the universal
quantum cloning (UQCM) and the phase covariant quantum cloning.


title:
On embeddedness of area-minimizing disks, and an application to
  constructing complete minimal surfaces

abstract:
  Let $\alpha$ be a polygonal Jordan curve in $\bfR^3$. We show that if
$\alpha$ satisfies certain conditions, then the least-area Douglas-Rad\'{o}
disk in $\bfR^3$ with boundary $\alpha$ is unique and is a smooth graph. As our
conditions on $\alpha$ are not included amongst previously known conditions for
embeddedness, we are enlarging the set of Jordan curves in $\bfR^3$ which are
known to be spanned by an embedded least-area disk. As an application, we
consider the conjugate surface construction method for minimal surfaces. With
our result we can apply this method to a wider range of complete catenoid-ended
minimal surfaces in $\bfR^3$.


title:
Comments on gap anisotropy and nodal constant Fermi velocity in a
  superconductor, BSCCO

abstract:
  On the basis of both the inhomogeneity of a superconductor, BSCCO-2212, and
the effect of measurement, we reveal that an anomalously large gap anisotropy
known as evidence of dx2-y2-wave symmetry [Phys. Rev. Lett. 70 (1993) 1553] is
not intrinsic, and that the constant Fermi velocity at node as an unsolved
problem [Nature 423 (2003) 398] is due to the dx2-y2-wave insulator-metal
transition.


title: Sums of Zeros for Certain Special Functions

abstract:
  Key words and phrases: q-Airy function (Ramanujan's entire function);
q-Bessel function; Bessel function; Airy function; Riemann zeta function;
Dirichlet L-series.


title: Constant mean curvature surfaces with two ends in hyperbolic space

abstract:
  We investigate the close relationship between minimal surfaces in Euclidean
3-space and constant mean curvature 1 surfaces in hyperbolic 3-space. Just as
in the case of minimal surfaces in Euclidean 3-space, the only complete
connected embedded constant mean curvature 1 surfaces with two ends in
hyperbolic space are well-understood surfaces of revolution -- the catenoid
cousins. In contrast to this, we show that, unlike the case of minimal surfaces
in Euclidean 3-space, there do exist complete connected immersed constant mean
curvature 1 surfaces with two ends in hyperbolic space that are not surfaces of
revolution -- the genus 1 catenoid cousins. The genus 1 catenoid cousins are of
interest because they show that, although minimal surfaces in Euclidean 3-space
and constant mean curvature 1 surfaces in hyperbolic 3-space are intimately
related, there are essential differences between these two sets of surfaces
(when the surfaces are considered globally). The proof we give of existence of
the genus 1 catenoid cousins is a mathematically rigorous verification that the
results of a computer experiment are sufficiently accurate to imply existence.


title: Boundary-induced abrupt transition in the symmetric exclusion process

abstract:
  We investigate the role of the boundary in the symmetric simple exclusion
process with competing nonlocal and local hopping events. With open boundaries,
the system undergoes a first order phase transition from a finite density phase
to an empty road phase as the nonlocal hopping rate increases. Using a cluster
stability analysis, we determine the location of such an abrupt nonequilibrium
phase transition, which agrees well with numerical results. Our cluster
analysis provides a physical insight into the mechanism behind this transition.
We also explain why the transition becomes discontinuous in contrast to the
case with periodic boundary conditions, in which the continuous phase
transition has been observed.


title: Spin-torque oscillator based on tilted magnetization of the fixed layer

abstract:
  The spin torque oscillator (STO), where the magnetization of the fixed layer
is tilted out of the film plane, is capable of strong microwave signal
generation in zero magnetic field. Through numerical simulations of the
Landau-Lifshitz-Gilbert-Slonczewski equations, within a macro-spin
approximation, we study the microwave signal generation as a function of drive
current for two realistic tilt angles. The tilt magnetization of the fixed
layer can be achieved by using a material with high out-of-plane
magnetocrystalline anisotropy, such as L10 FePt.


title: On the idempotents of Hecke algebras

abstract:
  We give a new construction of primitive idempotents of the Hecke algebras
associated with the symmetric groups. The idempotents are found as evaluated
products of certain rational functions thus providing a new version of the
fusion procedure for the Hecke algebras. We show that the normalization factors
which occur in the procedure are related to the Ocneanu--Markov trace of the
idempotents.


title:
Minimal classical communication and measurement complexity for quantum
  information splitting of a two qubit state

abstract:
  We provide explicit schemes for quantum information splitting (QIS) of real
or equatorial two qubit states among two parties, through the five particle
cluster and Brown states respectively. The schemes introduced are neither fully
deterministic nor completely probabilistic and are carried out in the case
where, the information that is to be shared is partially or fully known to the
sender. We show that, QIS can be accomplished with just two classical bits, as
against four classical bits, when the information is unknown to the sender.


title: Quantum Mechanics, is it magic?

abstract:
  We show that quantum mechanics is the first theory in human history that
violates the basic a priori principles that have shaped human thought since
immemorial times. Therefore although it is more contrary to magic than any body
of knowledge could be, what could be called its magic precisely resides in this
violation.


title:
Topos Mediated Gravity: Toward the Categorical Resolution of the
  Cosmological Constant Problem

abstract:
  According to D\"oring and Isham the spectral topos corresponds to any quantum
system. The description of a system in the topos becomes similar to this given
by classical theory, up to multiplication of observables. Logic of the emergent
theory is rather intuitionistic than classical. Adding to the language the type
of self-adjoint operators and their products, which are interpreted by the
on-stages daseinisations and their products, one gets commuting presheaves in
the topos. The interpretation agrees with on-stages daseinisations of squares
up to some automorphisms of the topos. The uncertainty principle does not hold
for such an interpretation. According to the recent proposition by the author,
topoi can modify local smooth spacetime structure. A way how to add gravity
into the spectral topos of a system is presented. Assuming that a quantum
system modifies the local spacetime structure and interacts with a
gravitational field via the spectral topos, the lowest energy modes of a
quantum harmonic oscillator are gravitationally nullified. Moreover, a theory
of gravity and systems should be symmetric with respect to the 2-group of
automorphisms of the category of topoi. Under the $\delta_0$-interpretation for
the hamiltonian of a quantum harmonic oscillator, its lowest modes have
vanishing contributions to the cosmological constant. This is related with a
fundamental higher symmetry group of gravity. Without the
$\delta_0$-interpretation, small non-zero value of the effective cosmological
constant can be approached.


title: Predicting the asymmetric response of a genetic switch to noise

abstract:
  We present a simple analytical tool which gives an approximate insight into
the stationary behavior of nonlinear systems undergoing the influence of a weak
and rapid noise from one dominating source, e.g. the kinetic equations
describing a genetic switch with the concentration of one substrate fluctuating
around a constant mean. The proposed method allows for predicting the
asymmetric response of the genetic switch to noise, arising from the
noise-induced shift of stationary states. The method has been tested on an
example model of the lac operon regulatory network: a reduced Yildirim-Mackey
model with fluctuating extracellular lactose concentration. We calculate
analytically the shift of the system's stationary states in the presence of
noise. The results of the analytical calculation are in excellent agreement
with the results of numerical simulation of the noisy system. The simulation
results suggest that the structure of the kinetics of the underlying
biochemical reactions protects the bistability of the lactose utilization
mechanism from environmental fluctuations. We also show that, in the
consequence of the noise-induced shift of stationary states, the presence of
fluctuations stabilizes the behavior of the system in a selective way: although
the extrinsic noise facilitates, to some extent, switching off the lactose
metabolism, the same noise prevents it from switching on.


title:
Automated Classification of Sloan Digital Sky Survey (SDSS) Stellar
  Spectra using Artificial Neural Networks

abstract:
  Automated techniques have been developed to automate the process of
classification of objects or their analysis. The large datasets provided by
upcoming spectroscopic surveys with dedicated telescopes urges scientists to
use these automated techniques for analysis of such large datasets which are
now available to the community. Sloan Digital Sky Survey (SDSS) is one of such
surveys releasing massive datasets. We use Probabilistic Neural Network (PNN)
for automatic classification of about 5000 SDSS spectra into 158 spectral type
of a reference library ranging from O type to M type stars.


title: Dimer lambda_d Expansion Computer Computations

abstract:
  In a previous paper an asymptotic expansion for lambda_d in powers of 1/d was
developed. The results of computer computations for some terms in the
expansion, as well as various quantities associated to the expansion, are
herein presented. The computations (in integer arithmetic) are actually done
only for d=1, d=2, and d=3, but some results for arbitrary dimension follow
from the general structure of the theory. In particular we obtain the next term
in powers of 1/d, the 1/d^3 term in the asymptotic expansion for lambda_d, as
well as checking the correctness of the terms previously calculated by hand.
  For d=2 and d=3 a second expansion for lambda_d is defined and numerically
studied. Contrary to our hopes this second type of expansion appears not to be
convergent. There is not enough evidence to argue if the expansions for
lambda_d in powers of 1/d are convergent for either d=2 or d=3, but likely they
are not. (Certainly convergence, but at a very slow rate, remains an
interesting possibility in all our cases.)


title: Quantum Gravity and Recovery of Information in Black Hole Evaporation

abstract:
  The Generalized Uncertainty Principle (GUP), motivated by current
alternatives of quantum gravity, produces significant modifications to the
Hawking radiation and the final stage of black hole evaporation. We show that
incorporation of the GUP into the quantum tunneling process (based on the
null-geodesic method) causes correlations between the tunneling probability of
different modes in the black hole radiation spectrum. In this manner, the
quantum information becomes encrypted in the Hawking radiation, and information
can be recovered as non-thermal GUP correlations between tunneling
probabilities of different modes.


title: A spectral solver for evolution problems with spatial S3-topology

abstract:
  We introduce a single patch collocation method in order to compute solutions
of initial value problems of partial differential equations whose spatial
domains are 3-spheres. Besides the main ideas, we discuss issues related to our
implementation and analyze numerical test applications. Our main interest lies
in cosmological solutions of Einstein's field equations. Motivated by this, we
also elaborate on problems of our approach for general tensorial evolution
equations when certain symmetries are assumed. We restrict to U(1)- and Gowdy
symmetry here.


title: Complex and Kaehler structures on compact solvmanifolds

abstract:
  We discuss our recent results on the existence and classification problem of
complex and Kaehler structures on compact solvmanifolds. In particular, we
determine in this paper all the complex surfaces which are diffeomorphic to
compact solvmanifolds (and compact homogeneous manifolds in general).


title:
Investigations of solutions of Einstein's field equations close to
  lambda-Taub-NUT

abstract:
  We present investigations of a class of solutions of Einstein's field
equations close to the family of lambda-Taub-NUT spacetimes. The studies are
done using a numerical code introduced by the author elsewhere. One of the main
technical complication is due to the S3-topology of the Cauchy surfaces.
Complementing these numerical results with heuristic arguments, we are able to
yield some first insights into the strong cosmic censorship issue and the
conjectures by Belinskii, Khalatnikov, and Lifschitz in this class of
spacetimes. In particular, the current investigations suggest that strong
cosmic censorship holds in this class. We further identify open issues in our
current approach and point to future research projects.


title: The Charmonium (Bottomonium) binding ate finite T

abstract:
  The charmonium (bottomonim) binding at finite temperature is studied with
static potentials extracted from the lattice QCD data of Kaczmarek et al. The
bottomonium spectrum is also studied. This is relevant for Hard Probes in Heavy
Ion Collisions.


title: Potentially $K_{m}-G$-graphical Sequences: A Survey

abstract:
  The set of all non-increasing nonnegative integers sequence $\pi=$
  ($d(v_1),$ $d(v_2),$ $...,$ $d(v_n)$) is denoted by $NS_n$.
  A sequence $\pi\in NS_n$ is said to be graphic if it is the degree sequence
of a simple graph $G$ on $n$ vertices, and such a graph $G$ is called a
realization of $\pi$. The set of all graphic sequences in $NS_n$ is denoted by
$GS_n$. A graphical sequence $\pi$ is potentially $H$-graphical if there is a
realization of $\pi$ containing $H$ as a subgraph, while $\pi$ is forcibly
$H$-graphical if every realization of $\pi$ contains $H$ as a subgraph. Let
$K_k$ denote a complete graph on $k$ vertices. Let $K_{m}-H$ be the graph
obtained from $K_{m}$ by removing the edges set $E(H)$ of the graph $H$ ($H$ is
a subgraph of $K_{m}$). This paper summarizes briefly some recent results on
potentially $K_{m}-G$-graphic sequences and give a useful classification for
determining $\sigma(H,n)$.


title: Final state interactions in the decay $B^0 \to \eta_c K^*$

abstract:
  In this article, we study the final-state rescattering effects in the decay
$B^0 \to \eta_cK^*$, the numerical results indicate the corrections are
comparable with the contribution from the naive factorizable amplitude, and the
total amplitudes can accommodate the experimental data.


title:
Spatially Resolved Stellar Kinematics of Field Early-Type Galaxies at
  z=1: Evolution of the Rotation Rate

abstract:
  We use the spatial information of our previously published VLT/FORS2
absorption line spectroscopy to measure mean stellar velocity and velocity
dispersion profiles of 25 field early-type galaxies at a median redshift z=0.97
(full range 0.6<z<1.2). This provides the first detailed study of early-type
galaxy rotation at these redshifts. From surface brightness profiles from HST
imaging we calculate two-integral oblate axisymmetric Jeans equation models for
the observed kinematics. Fits to the data yield for each galaxy the degree of
rotational support and the mass-to-light ratio M/L_Jeans. S0 and Sa galaxies
are generally rotationally supported, whereas elliptical galaxies rotate less
rapidly or not at all. Down to M(B)=-19.5 (corrected for luminosity evolution),
we find no evidence for evolution in the fraction of rotating early-type (E+S0)
galaxies between z=1 (63+/-11%) and the present (61+/-5%). We interpret this as
evidence for little or no change in the field S0 fraction with redshift. We
compare M/L_Jeans with M/L_vir inferred from the virial theorem and globally
averaged quantities and assuming homologous evolution. There is good agreement
for non-rotating (mostly E) galaxies. However, for rotationally supported
galaxies (mostly S0) M/L_Jeans is on average ~40% higher than M/L_vir. We
discuss possible explanations and the implications for the evolution of M/L
between z=1 and the present and its dependence on mass.


title: An intrinsic non-triviality of graphs

abstract:
  We say that a graph is intrinsically non-trivial if every spatial embedding
of the graph contains a non-trivial spatial subgraph. We prove that an
intrinsically non-trivial graph is intrinsically linked, namely every spatial
embedding of the graph contains a non-splittable 2-component link. We also show
that there exists a graph such that every spatial embedding of the graph
contains either a non-splittable 3-component link or an irreducible spatial
handcuff graph whose constituent 2-component link is split.


title:
The intensity contrast of solar granulation: comparing Hinode SP results
  with MHD simulations

abstract:
  The contrast of granulation is an important quantity characterizing solar
surface convection. We compare the intensity contrast at 630 nm, observed using
the Spectro-Polarimeter (SP) aboard the Hinode satellite, with the 3D radiative
MHD simulations of V{\"o}gler & Sch{\"u}ssler (2007). A synthetic image from
the simulation is degraded using a theoretical point-spread function of the
optical system, and by considering other important effects. The telescope
aperture and the obscuration by the secondary mirror and its attachment spider,
reduce the simulated contrast from 14.4 % to 8.5 %. A slight effective defocus
of the instrument brings the simulated contrast down to 7.5 %, close to the
observed value of 7.0 %. A proper consideration of the effects of the optical
system and a slight defocus, lead to sufficient degradation of the synthetic
image from the MHD simulation, such that the contrast reaches almost the
observed value. The remaining small discrepancy can be ascribed to straylight
and slight imperfections of the instrument, which are difficult to model.
Hence, Hinode SP data are consistent with a granulation contrast which is
predicted by 3D radiation MHD simulations.


title:
On the Joint Distribution of Energy Levels of Random Schroedinger
  Operators

abstract:
  We consider operators with random potentials on graphs, such as the lattice
version of the random Schroedinger operator. The main result is a general bound
on the probabilities of simultaneous occurrence of eigenvalues in specified
distinct intervals, with the corresponding eigenfunctions being separately
localized within prescribed regions. The bound generalizes the Wegner estimate
on the density of states. The analysis proceeds through a new multiparameter
spectral averaging principle.


title:
Electromagnetic and strong contributions to dAu soft coherent inelastic
  diffraction at RHIC

abstract:
  We estimate electromagnetic (ultra-peripheral) and strong contributions to
dAu soft coherent inelastic diffraction at RHIC, dAu \to X Au. We show that the
electromagnetic contribution is the dominant one and that the corresponding
cross section is sizable, \sigma^{dAu \to XAu}_{\rm e.m.}=214 mb, which
constitutes 10% of the total dAu inelastic cross section.


title:
A state sum invariant for regular isotopy of links having a polynomial
  number of states

abstract:
  The state sum regular isotopy invariant of links which I introduce in this
work is a generalization of the Jones Polynomial. So it distinguishes any pair
of links which are distinguishable by Jones'. This new invariant, denoted {\em
VSE-invariant} is strictly stronger than Jones': I detected a pair of links
which are not distinguished by Jones' but are distinguished by the new
invariant. The full VSE-invariant has $3^n$ states. However, there are useful
specializations of it parametrized by an integer k, having
$O(n^k)=\sum_{\ell=0}^k {n \choose \ell} 2^\ell $ states. The link with more
crossings of the pair which was distinguished by the VSE-invariant has 20
crossings. The specialization which is enough to distinguish corresponds to k=2
and has only 801 states, as opposed to the $2^{20} = 1,048,576$ states of the
Jones polynomial of the same link. The full VSE-invariant of it has $3^{20} =
3,486,784,401$ states. The VSE-invariant is a good alternative for the Jones
polynomial when the number of crossings makes the computation of this
polynomial impossible. For instance, for $k=2$ the specialization of the
VSE-invariant of a link with $n=500$ crossings can be computed in a few
minutes, since it has only $2 n^2+1 = 500,001$ states.


title: Products of Toeplitz Operators on a Vector Valued Bergman Space

abstract:
  We give a necessary and a sufficient condition for the boundedness of the
Toeplitz product $T_FT_{G^*}$ on the vector valued Bergman space
$L_a^2(\mathbb{C}^n)$, where $F$ and $G$ are matrix symbols with scalar valued
Bergman space entries. The results generalize existing results in the scalar
valued Bergman space case. We also characterize boundedness and invertibility
of Toeplitz products $T_FT_{G^*}$ in terms of the Berezin transform,
generalizing results found by Zheng and Stroethoff for the scalar valued
Bergman space.


title: Twistors, 4-symmetric spaces and integrable systems

abstract:
  An order four automorphism of a Lie algebra gives rise to an integrable
system discussed by Terng. We show that solutions of this system may be
identified with certain vertically harmonic twistor lifts of conformal maps of
surfaces in a Riemannian symmetric space.
  Specialising to 4-dimensional target, we find that surfaces with holomorphic
mean curvature in 4-dimensional spaces with constant sectional or holomorphic
sectional curvatures constitute an integrable system as do Hamiltonian
stationary Lagrangian surfaces in a 4-dimensional Hermitian symmetric space
(this last being a result of Helein-Romon).


title: Exotic clouds in the local interstellar medium

abstract:
  The neutral interstellar medium (ISM) inside the Local Bubble (LB) has been
known to have properties typical of the warm neutral medium (WNM). However,
several recent neutral hydrogen (HI) absorption experiments show evidence for
the existence of at least several cold diffuse clouds inside or at the boundary
of the LB, with properties highly unusual relative to the traditional cold
neutral medium. These cold clouds have a low HI column density, and AU-scale
sizes. As the kinematics of cold and warm gas inside the LB are similar, this
suggests a possibility of all these different flavors of the local ISM
belonging to the same interstellar flow. The co-existence of warm and cold
phases inside the LB is exciting as it can be used to probe the thermal
pressure inside the LB. In addition to cold clouds, several discrete screens of
ionized scattering material are clearly located inside the LB.
  The cold exotic clouds inside the LB are most likely long-lived, and we
expect many more clouds with similar properties to be discovered in the future
with more sensitive radio observations. While physical mechanisms responsible
for the production of such clouds are still poorly understood, dynamical
triggering of phase conversion and/or interstellar turbulence are likely to
play an important role.


title: Explaining the Logical Nature of Electrical Solitons in Neural Circuits

abstract:
  Neurons are modeled electrically based on ferroelectric membranes thin enough
to permit charge transfer, conjectured to be the tunneling result of thermally
energetic ions and random electrons. These membranes can be triggered to
produce electrical solitons, the main signals for brain associative memory and
logical processing. Dendritic circuits are modeled, and electrical solitons are
simulated to demonstrate the nature of soliton propagation, soliton reflection,
the collision of solitons, as well as soliton OR gates, AND gates, XOR gates
and NOT gates.


title: Siegel disk for complexified Henon map

abstract:
  It is shown that critical phenomena associated with Siegel disk, intrinsic to
1D complex analytical maps, survives in 2D complex invertible dissipative
H\'{e}non map. Special numerical method of estimation of the Siegel disk
scaling center position (for 1D maps it corresponds to extremum) for
multi-dimensional invertible maps are developed.


title: Capacity Definitions for General Channels with Receiver Side Information

abstract:
  We consider three capacity definitions for general channels with channel side
information at the receiver, where the channel is modeled as a sequence of
finite dimensional conditional distributions not necessarily stationary,
ergodic, or information stable. The {\em Shannon capacity} is the highest rate
asymptotically achievable with arbitrarily small error probability. The {\em
capacity versus outage} is the highest rate asymptotically achievable with a
given probability of decoder-recognized outage. The {\em expected capacity} is
the highest average rate asymptotically achievable with a single encoder and
multiple decoders, where the channel side information determines the decoder in
use. As a special case of channel codes for expected rate, the code for
capacity versus outage has two decoders: one operates in the non-outage states
and decodes all transmitted information, and the other operates in the outage
states and decodes nothing. Expected capacity equals Shannon capacity for
channels governed by a stationary ergodic random process but is typically
greater for general channels. These alternative capacity definitions
essentially relax the constraint that all transmitted information must be
decoded at the receiver. We derive capacity theorems for these capacity
definitions through information density. Numerical examples are provided to
demonstrate their connections and differences. We also discuss the implication
of these alternative capacity definitions for end-to-end distortion,
source-channel coding and separation.


title:
Spatial Periodicity of Galaxy Number Counts, CMB Anisotropy, and SNIa
  Hubble Diagram Based on the Universe Accompanied by a Non-Minimally Coupled
  Scalar Field

abstract:
  We have succeeded in establishing a cosmological model with a non-minimally
coupled scalar field $\phi$ that can account not only for the spatial
periodicity or the {\it picket-fence structure} exhibited by the galaxy $N$-$z$
relation of the 2dF survey but also for the spatial power spectrum of the
cosmic microwave background radiation (CMB) temperature anisotropy observed by
the WMAP satellite. The Hubble diagram of our model also compares well with the
observation of Type Ia supernovae. The scalar field of our model universe
starts from an extremely small value at around the nucleosynthesis epoch,
remains in that state for sufficiently long periods, allowing sufficient time
for the CMB temperature anisotropy to form, and then starts to grow in
magnitude at the redshift $z$ of $\sim 1$, followed by a damping oscillation
which is required to reproduce the observed picket-fence structure of the
$N$-$z$ relation. To realize such behavior of the scalar field, we have found
it necessary to introduce a new form of potential $V(\phi)\propto
\phi^2\exp(-q\phi^2)$, with $q$ being a constant. Through this parameter $q$,
we can control the epoch at which the scalar field starts growing.

categories: astro-ph astro-ph.CO gr-qc hep-ph hep-th


title: Jump processes on leaves of multibranching trees

abstract:
  The p-adic numbers have found applications in a wide range of diverse fields
of research. In some applications the algebraic properties of p-adics enter as
an indispensable ingredient of the theory. Another class of applications has to
do with hierarchical tree like systems. In this context the applications are
based on the well known correspondence between p-adics and the trees with
p-branches emerging from every branching point. Then the algebraic structure
does not enter and p-adics are used merely as a labeling system for the tree
branches. We introduce a space of numerical sequences suitable for labeling the
trees with varying number of branches emerging from the branching points. We
equipe this space with a non Archimedian metric and describe its basic
topological properties. We also demonstrate that the known construction of the
stochastic processes on p-adics carry over to the stochastic processes on the
above mentioned space and hence on the corresponding trees.


title:
Superluminal tunneling of microwaves in smoothly varying transmission
  lines

abstract:
  Tunneling of microwaves through a smooth barrier in a transmission line is
considered. In contrast to standard wave barriers, we study the case where the
dielectric permittivity is positive, and the barrier is caused by the
inhomogeneous dielectric profile. It is found that reflectionless, superluminal
tunneling can take place for waves with a finite spectral width. The
consequences of these findings are discussed, and an experimental setup testing
our predictions is proposed.


title:
Character of Locally Inequivalent Classes of States and Entropy of
  Entanglement

abstract:
  In this letter we have established the physical character of pure bipartite
states with the same amount of entanglement in the same Schmidt rank that
either they are local unitarily connected or they are incomparable. There exist
infinite number of deterministically locally inequivalent classes of pure
bipartite states in the same Schmidt rank (starting from three) having same
amount of entanglement. Further, if there exists incomparable states with same
entanglement in higher Schmidt ranks (greater than three), then they should
differ in at least three Schmidt coefficients.


title: Entropy and its variational principle for noncompact metric spaces

abstract:
  In the present paper, we introduce a natural extension of AKM-topological
entropy for noncompact spaces and prove a variational principle which states
that the topological entropy, the supremum of the measure theoretical entropies
and the minimum of the metric theoretical entropies always coincide. We apply
the variational principle to show that the topological entropy of automorphisms
of simply connected nilpotent Lie groups always vanishes. This shows that the
classical formula for the entropy of an automorphism of a noncompact Lie group
is just an upper bound for its topological entropy.


title: Embeddings of four-valent framed graphs into two-surfaces

abstract:
  We study the problem of finding the minimal (maximal) genus for a surface
where a given four-valent graph with fixed opposite edge structure can be
embedded into. We find several partial relations and give new reformulations in
combinatorial and knot theoretic languages.


title: Finite generation of Tate cohomology

abstract:
  Let G be a finite group and let k be a field of characteristic p. Given a
finitely generated indecomposable non-projective kG-module M, we conjecture
that if the Tate cohomology $\HHHH^*(G, M)$ of G with coefficients in M is
finitely generated over the Tate cohomology ring $\HHHH^*(G, k)$, then the
support variety V_G(M) of M is equal to the entire maximal ideal spectrum
V_G(k). We prove various results which support this conjecture. The converse of
this conjecture is established for modules in the connected component of k in
the stable Auslander-Reiten quiver for kG, but it is shown to be false in
general. It is also shown that all finitely generated kG-modules over a group G
have finitely generated Tate cohomology if and only if G has periodic
cohomology.


title:
Origin of resistivity minima at low temperature in ferromagnetic
  metallic manganites

abstract:
  The resistivity and magnetoresistance measurements were carried out on thin
film of La0.7Ca0.3MnO3 to investigate the possible origin of low temperature
resistivity minimum observed in these samples. We observed large hysteresis in
the magnetoresistance at low temperature; 5K and the sample current I has large
effect on resistivity minima temperature. The observation of hysteresis at low
temperatures suggests the presence of inhomogeneity at low temperatures. These
in-homogeneities consist of regions of different resistive phases. It appears
that the high resistive phase prevents the tunneling of charge carriers between
two low resistive regions and thus giving rise to the resistivity minimum in
these samples.


title: A hysteresis model for two-dimensional input signals

abstract:
  We formulate and analyze a new model of vector hysteresis for the case of
two-dimensional input signals. We prove certain properties of this model and we
present the solutions to two identification problems connected with our model.


title:
Vibrational modes of metal nanoshells and bimetallic core-shell
  nanoparticles

abstract:
  We study theoretically spectrum of radial vibrational modes in composite
metal nanostructures such as bimetallic core-shell particles and metal
nanoshells with dielectric core in an environment. We calculate frequencies and
damping rates of fundamental (breathing) modes for these nanostructures along
with those of two higher-order modes. For metal nanoshells, we find that the
breathing mode frequency is always lower than the one for solid particles of
the same size, while the damping is higher and increases with reduction of the
shell thickness. We identify two regimes that can be characterized as weakly
damped and overdamped vibrations in the presence of external medium. For
bimetalllic particles, we find periodic dependence of frequency and damping
rate on the shell thickness with period determined by mode number. For both
types of nanostructures, the frequency of higher modes is nearly independent of
the environment, while the damping rate shows strong sensitivity to outside
medium.


title: Magnetic phases evolution in the LaMn1-xFexO3+y system

abstract:
  We have investigated the crystal structure and magnetic properties for
polycrystalline samples of LaMn1-xFexO3+y, in the whole range x=0.0 to x=1.0,
prepared by solid state reaction in air. All samples show the ORT-2
orthorhombic structure that suppresses the Jahn-Teller distortion, thus
favoring a ferromagnetic (FM) superexchange (SE) interaction between
Mn^{3+}-O-Mn^{3+}. For x=0.0 the oxygen excess (y ~ 0.09) produces vacancies in
the La and Mn sites and generates a fraction around 18% of Mn^{4+} ions and 82%
of the usual Mn^{3+} ions, with possible double exchange interaction between
them. The Fe doping in this system is known to produce only stable Fe^{3+}
ions. We find an evolution from a fairly strong FM phase with a Curie
temperature T_{C} ~ 160 K, for x=0.0, to an antiferromagnetic (AFM) phase with
T_{N} = 790 K, for x=1.0, accompanied by clear signatures of a cluster-glass
behavior. For intermediate Fe contents a mixed-phase state occurs, with a
gradual decrease (increase) of the FM (AFM) phase, accompanied by a systematic
transition broadening for 0.2 < x < 0.7. A model based on the expected exchange
interaction among the various magnetic-ion types, accounts very well for the
saturation-magnetization dependence on Fe doping.


title: Chaotic Advection and the Emergence of Tori in the K\"uppers-Lortz State

abstract:
  Motivated by the roll-switching behavior observed in rotating
Rayleigh-B\'enard convection, we define a K\"uppers-Lortz (K-L) state as a
volume-preserving flow with periodic roll switching. For an individual roll
state, the Lagrangian particle trajectories are periodic. In a system with
roll-switching, the particles can exhibit three-dimensional, chaotic motion. We
study a simple phenomenological map that models the Lagrangian dynamics in a
K-L state. When the roll axes differ by $120^{\circ}$ in the plane of rotation,
we show that the phase space is dominated by invariant tori if the ratio of
switching time to roll turnover time is small. When this parameter approaches
zero these tori limit onto the classical hexagonal convection patterns, and, as
it gets large, the dynamics becomes fully chaotic and well-mixed. For
intermediate values, there are interlinked toroidal and poloidal structures
separated by chaotic regions. We also compute the exit time distributions and
show that the unbounded chaotic orbits are normally diffusive. Although the map
presumes instantaneous switching between roll states, we show that the
qualitative features of the flow persist when the model has smooth, overlapping
time-dependence for the roll amplitudes (the Busse-Heikes model).


title: Autocorrelation Function for Radio Galaxies

abstract:
  We discuss the autocorrelation function $/zeta (r)$ for the sample 1157
radio-identified galaxies . The sample of galaxies is based on the Las Campanas
Redshift Survey (LCRS) and 1.4 Ghz NRA)-VLA Sky Survey (NVSS) catalog of the
radio sources. For separation $2-15h^{-1}$ Mpc autocorrelation function $/zeta
(r)$$\gamma (s)$ can be approximated by the power law with correlation length
and slope $-\gamma (s)=-1.8$. There are no clearly differences for correlation
length between AGN and SB galaxies while value $\gamma$ for both samples are
different: $\gamma=2.4$ for AGN and $\gamma=1.7$ for SB.


title:
On the Nonlinear Continuum Mechanics of Space and the Notion of
  Luminiferous Medium

abstract:
  We prove that, when linearized, the governing equations of an incompressible
elastic continuum yield Maxwell's equations as corollaries. Through judicious
distinction between the referential and local descriptions, the principle of
material invariance is established and shown to be a true covariance principle,
unlike the Lorentz covariance, which is valid only for non-deforming frames in
rectilinear relative motion. Thus, this paper establishes that electrodynamics
can be fully explained if one assumes that it is the manifestation of the
internal forces of an underlying elastic material which we term the
metacontinuum.
  The new frame-indifferent formulation of electrodynamics is shown to
incorporate the Lorentz force as an integral part of Faraday's law, rather than
as an additional empirical variable. Respectively, if the upper-convected
derivative is added in Maxwell's displacement current it can explain
Biot-Savart's and Oersted-Ampere's laws. An immediate corollary of the material
invariance is the Galilean invariance of the model.
  The possible detection of the absolute continuum is also discussed. First,
the famous experiment of Ives and Stilwell is reexamined with a modified
Bohr-Rydberg formula for the emitted frequencies from a moving atom, and it is
shown that the results are fully compatible with the presence of an absolute
medium. Second, a new interferometry experiment is proposed in which the
first-order Doppler effect can be measured, and thus the presence of a medium
at rest can be unequivocally established.


title: Neutron Electric Dipole Moment Experiments

abstract:
  The neutron electric dipole moment (EDM) provides unique information on CP
violation and physics beyond the Standard Model. We first review the history of
experimental searches for neutron electric dipole moment. The status of future
neutron EDM experiments, including experiments using ultra-cold neutrons
produced in superfluid helium, will then be presented.


title:
Expected Message Delivery Time for Small-world Networks in the Continuum
  Limit

abstract:
  Small-world networks are networks in which the graphical diameter of the
network is as small as the diameter of random graphs but whose nodes are highly
clustered when compared with the ones in a random graph. Examples of
small-world networks abound in sociology, biology, neuroscience and physics as
well as in human-made networks. This paper analyzes the average delivery time
of messages in dense small-world networks constructed on a plane. Iterative
equations for the average message delivery time in these networks are provided
for the situation in which nodes employ a simple greedy geographic routing
algorithm. It is shown that two network nodes communicate with each other only
through their short-range contacts, and that the average message delivery time
rises linearly if the separation between them is small. On the other hand, if
their separation increases, the average message delivery time rapidly saturates
to a constant value and stays almost the same for all large values of their
separation.


title: Tilting generators via ample line bundles

abstract:
  It is known that a tilting generator on an algebraic variety $X$ gives a
derived equivalence between $X$ and a certain non-commutative algebra. In this
paper, we explain a method to construct a tilting generator from an ample line
bundle, and construct it in several examples.


title:
Ion-dipole interactions are asymptotically unscreened by water in
  dipolar nanopores, yielding patterned ion distributions

abstract:
  The permeation, rejection, and transport of electrolytes in water-filled
nanopores are critical to ion current gating and desalinalion processes in
synthetic porous membranes and the functions of biological ion channels. Mile
the effects of confinement pore polarizability, and discrete channel charge
sites have been much studied, the potentially dramatic impact of dipole-lined
synthetic pores on electrolytes has seldom been addressed. Dipole layers
naturally occur on the interior surfaces of certain nanopores, leading to
intrinsic preference for cations or anions. This preference can be exploited
when the membrane surface is functionalized differently from the pore interior
or when there are alternating dipolar/nondipolar stretches inside a long pore.
The dipole-ion interaction is asymptotically unscreened by water, leading to
ionic, charge segregated, insulating behavior that can block ion transport, and
potentially novel current-voltage (I-V) characteristics.


title:
Continuity properties and infinite divisibility of stationary
  distributions of some generalized Ornstein--Uhlenbeck processes

abstract:
  Properties of the law $\mu$ of the integral
$\int_0^{\infty}c^{-N_{t-}}\,dY_t$ are studied, where $c>1$ and
$\{(N_t,Y_t),t\geq0\}$ is a bivariate L\'{e}vy process such that $\{N_t\}$ and
$\{Y_t\}$ are Poisson processes with parameters $a$ and $b$, respectively. This
is the stationary distribution of some generalized Ornstein--Uhlenbeck process.
The law $\mu$ is parametrized by $c$, $q$ and $r$, where $p=1-q-r$, $q$, and
$r$ are the normalized L\'{e}vy measure of $\{(N_t,Y_t)\}$ at the points
$(1,0)$, $(0,1)$ and $(1,1)$, respectively. It is shown that, under the
condition that $p>0$ and $q>0$, $\mu_{c,q,r}$ is infinitely divisible if and
only if $r\leq pq$. The infinite divisibility of the symmetrization of $\mu$ is
also characterized. The law $\mu$ is either continuous-singular or absolutely
continuous, unless $r=1$. It is shown that if $c$ is in the set of
Pisot--Vijayaraghavan numbers, which includes all integers bigger than 1, then
$\mu$ is continuous-singular under the condition $q>0$. On the other hand, for
Lebesgue almost every $c>1$, there are positive constants $C_1$ and $C_2$ such
that $\mu$ is absolutely continuous whenever $q\geq C_1p\geq C_2r$. For any
$c>1$ there is a positive constant $C_3$ such that $\mu$ is continuous-singular
whenever $q>0$ and $\max\{q,r\}\leq C_3p$. Here, if $\{N_t\}$ and $\{Y_t\}$ are
independent, then $r=0$ and $q=b/(a+b)$.


title: Speed-up via Quantum Sampling

abstract:
  The Markov Chain Monte Carlo method is at the heart of efficient
approximation schemes for a wide range of problems in combinatorial enumeration
and statistical physics. It is therefore very natural and important to
determine whether quantum computers can speed-up classical mixing processes
based on Markov chains. To this end, we present a new quantum algorithm, making
it possible to prepare a quantum sample, i.e., a coherent version of the
stationary distribution of a reversible Markov chain. Our algorithm has a
significantly better running time than that of a previous algorithm based on
adiabatic state generation. We also show that our methods provide a speed-up
over a recently proposed method for obtaining ground states of (classical)
Hamiltonians.


title: BES3 time of flight monitoring system

abstract:
  A Time of Flight monitoring system has been developed for BES3.
  The light source is a 442-443 nm laser diode, which is stable and provides a
pulse width as narrow as 50 ps and a peak power as large as 2.6 W. Two
optical-fiber bundles with a total of 512 optical fibers, including spares, are
used to distribute the light pulses to the Time of Flight counters. The design,
operation, and performance of the system are described.


title: Braneworld Remarks in Riemann-Cartan Manifolds

abstract:
  We analyze the projected effective Einstein equation in a 4-dimensional
arbitrary manifold embedded in a 5-dimensional Riemann-Cartan manifold. The
Israel-Darmois matching conditions are investigated, in the context where the
torsion discontinuity is orthogonal to the brane. Unexpectedly, the presence of
torsion terms in the connection does not modify such conditions whatsoever,
despite of the modification in the extrinsic curvature and in the connection.
Then, by imposing the Z_2-symmetry, the Einstein equation obtained via
Gauss-Codazzi formalism is extended, in order to now encompass the torsion
terms. We also show that the factors involving contorsion change drastically
the effective Einstein equation on the brane, as well as the effective
cosmological constant.


title:
A posteriori error control for discontinuous Galerkin methods for
  parabolic problems

abstract:
  We derive energy-norm a posteriori error bounds for an Euler time-stepping
method combined with various spatial discontinuous Galerkin schemes for linear
parabolic problems. For accessibility, we address first the spatially
semidiscrete case, and then move to the fully discrete scheme by introducing
the implicit Euler time-stepping. All results are presented in an abstract
setting and then illustrated with particular applications. This enables the
error bounds to hold for a variety of discontinuous Galerkin methods, provided
that energy-norm a posteriori error bounds for the corresponding elliptic
problem are available. To illustrate the method, we apply it to the interior
penalty discontinuous Galerkin method, which requires the derivation of novel a
posteriori error bounds. For the analysis of the time-dependent problems we use
the elliptic reconstruction technique and we deal with the nonconforming part
of the error by deriving appropriate computable a posteriori bounds for it.


title:
Impurity Quantum Phase Transition in a Current-Carrying d-Wave
  Superconductor

abstract:
  We study an Anderson impurity embedded in a d-wave superconductor carrying a
supercurrent. The low-energy impurity behavior is investigated by using the
numerical renormalization group method developed for arbitrary electronic bath
spectra. The results explicitly show that the local impurity state is
completely screened upon the non-zero current intensity. The impurity quantum
criticality is in accordance with the well-known Kosterlitz-Thouless
transition.


title: Families of absolutely simple hyperelliptic jacobians

abstract:
  We prove that the jacobian of a hyperelliptic curve $y^2=(x-t)h(x)$ has no
nontrivial endomorphisms over an algebraic closure of the ground field $K$ of
characteristic zero if $t \in K$ and the Galois group of the polynomial $h(x)$
over $K$ is "very big" and $deg(h)$ is an even number >8. (The case of odd
$deg(h)>3$ follows easily from previous results of the author.)


title:
Smoothed Particle Hydrodynamics in Thermal Phases of a One Dimensional
  Molecular Cloud

abstract:
  We present an investigation on effect of the ion-neutral (or ambipolar)
diffusion heating rate on thermal phases of a molecular cloud. We use the
modeling of ambipolar diffusion with two-fluid smoothed particle hydrodynamics,
as discussed by Nejad-Asghar & Molteni. We take into account the ambipolar
drift heating rate on the net cooling function of the molecular clouds, and we
investigate the thermal phases in a self-gravitating magnetized one dimensional
slab. The results show that the isobaric thermal instability criterion is
satisfied in the outer parts of the cloud, thus, these regions are thermally
unstable while the inner part is stable. This feature may be responsible for
the planet formation in the outer parts of a collapsing molecular cloud and/or
may also be relevant for the formation of star forming dense cores in the
clumps.


title: Parameter estimation of high-dimensional linear differential equations

abstract:
  We study the problem of estimating the coefficients in linear ordinary
differential equations (ODE's) with a diverging number of variables when the
solutions are observed with noise. The solution trajectories are first smoothed
with local polynomial regression and the coefficients are estimated with
nonconcave penalty proposed by \cite{fan01}. Under some regularity and sparsity
conditions, we show the procedure can correctly identifies nonzero coefficients
with probability converging to one and the estimators for nonzero coefficients
have the same asymptotic normal distribution as they would have when the zero
coefficients are known and the same two-step procedure is used. Our asymptotic
results are valid under the misspecified case where linear ODE's are only used
as an approximation to nonlinear ODE's, and the estimates will converge to the
coefficients of the best approximating linear system. From our results, when
the solution trajectories of the ODE's are sufficiently smooth, the parametric
$\sqrt{n}$ rate is achieved even though nonparametric regression estimator is
used in the first step of the procedure. The performance of the two-step
procedure is illustrated by a simulation study as well as an application to
yeast cell-cycle data.


title: O(3) Flavor Symmetry and an Empirical Neutrino Mass Matrix

abstract:
  Based on a new approach to quark and lepton masses, where the mass spectra
originate in vacuum expectation values of O(3)-flavor 1+5 (gauge singlet)
scalars, a neutrino mass matrix of a new type is speculated. The mass matrix is
described in terms of the up-quark and charged lepton masses, and, by assuming
a special flavor basis, it can be accommodated to a nearly tribimaximal mixing
without explicitly assuming a discrete symmetry. Quark mass relations are also
discussed based on the new approach.


title:
Yet another generalization of Postnikov's hook length formula for binary
  trees

abstract:
  We discover another one-parameter generalization of Postnikov's hook length
formula for binary trees. The particularity of our formula is that the hook
length $h_v$ appears as an exponent. As an application, we derive another
simple hook length formula for binary trees when the underlying parameter takes
the value 1/2.


title: The automatic gain-matching in the PIBETA CsI calorimeter

abstract:
  Segmented electromagnetic calorimeters are used to determine both the total
energy and direction (momentum components) of charged particles and photons. A
trade off is involved in selecting the degree of segmentation of the
calorimeter as the spatial and energy resolutions are affected differently.
Increased number of individual detectors reduces accidental particle pile-up
per detector but introduces complications related to ADC pedestals and pedestal
variations, exacerbates the effects of electronic noise and ground loops, and
requires summing and discrimination of multiple analog signals. Moreover,
electromagnetic showers initiated by individual ionizing particles spread over
several detectors. This complicates the precise gain-matching of the detector
elements which requires an iterative procedure. The PIBETA calorimeter is a
240-module pure CsI non-magnetic detector optimized for detection of photons
and electrons in the energy range 5-100 MeV. We present the
computer-controlled, automatic, in situ gain-matching procedure that we
developed and used routinely in several rare pion and muon decay experiments
with the PIBETA detector.


title:
Energy and centrality dependence of particle production at very low
  transverse momenta in Au+Au collisions

abstract:
  The PHOBOS experiment at RHIC has the unique capability of measuring particle
production at very low transverse momenta. New results on low-transverse
momentum invariant yields of pions, kaons, protons and antiprotons in 200 GeV
Au+Au collisions are presented as a function of the collision centrality for
the 50% most central events. In contrast to the results from d+Au collisions,
no $m_{T}$ scaling is observed in the very low $p_{T}$ region. The low
transverse momentum yields agree with extrapolations from intermediate
transverse momentum measurements. For all collision centralities a flattening
of the transverse momentum spectra is observed, consistent with a rapid
transverse expansion of the system.


title:
Prediction of Half Metallicity along the Edge of Boron Nitride Zigzag
  Nanoribbons

abstract:
  First-principles calculations reveal half metallicity in zigzag boron nitride
(BN) nanoribbons (ZBNNRs). When the B edge, but not the N edge, of the ZBNNR is
passivated, despite being a pure $sp$-electron system, the ribbon shows a giant
spin splitting. The electrons at the Fermi level are 100% spin polarized with a
half-metal gap of 0.38 eV and its conductivity is dominated by metallic
single-spin states. The two states across at the Dirac point have different
molecular origins, which signals a switch of carrier velocity. The ZBNNR should
be a good potential candidate for widegap spintronics.


title:
High-resolution radio observations of nuclear and circumnuclear
  starbursts in Luminous Infrared Galaxies

abstract:
  High-resolution radio observations of nearby starburst galaxies have shown
that the distribution of their radio emission consists of a compact (<150 pc),
high surface brightness, central radio source immersed in a low surface
brightness circumnuclear halo. This radio structure is similar to that detected
in bright Seyferts galaxies like NGC 7469 or Mrk 331, which display clear
circumnuclear rings. While the compact, centrally located radio emission in
these starbursts might be generated by a point-like source (AGN), or by the
combined effect of multiple radio supernovae and supernova remnants (e.g., the
evolved nuclear starburst in Arp~220), it seems well established that the
circumnuclear regions of those objects host an ongoing burst of star-formation
(e.g., NGC 7469; Colina et al. 2001, Alberdi et al. 2006). Therefore,
high-resolution radio observations of Luminous Infra-Red Galaxies (LIRGs) in
our local universe are a powerful tool to probe the dominant dust heating
mechanism in their nuclear and circumnuclear regions.
  In this contribution, we show results obtained from VLA-A, MERLIN, and EVN
(VLBI) radio observations of the galaxies NGC 7469 (D~70 Mpc) and IRAS
18293-3413 (D ~ 79 Mpc), where two extremely bright radio supernovae have been
found. High-resolution studies of these and other LIRGs would allow us to
determine the core-collapse supernova rate in them, as well as their
star-formation rate.


title:
The Frolicher--Kriegl differentiabilities as a particular case of the
  Bertram--Glockner--Neeb construction

abstract:
  We prove that the order $k$ differentiability classes for $k=0,1,...\infty$
in the "arc-generated" interpretation of the Lipschitz theory of
differentiation by Frolicher and Kriegl can be obtained as particular cases of
the general construction by Bertram, Glockner and Neeb leading to $C^k$
differentiabilities from a given $C^0$ concept.


title: Applying Shower Development Universality to KASCADE Data

abstract:
  On basis of the theorem of a universal shower development stating that a
hadronically generated extensive air shower is completely described by the
primary energy, the position of the shower maximum and a parameter related to
the total muon number, the so-called correlation curve method is developed and
applied to KASCADE data. Correlation information of the muon and electron
content of showers measured by the KASCADE experiment are used for the
reconstruction of energy and mass of primary cosmic rays. Systematic
uncertainties of the method and the results are discussed in detail. It is
shown that by this method general tendencies in spectrum and composition indeed
can be revealed, but the absolute normalization in energy and mass scale
requires much more detailed simulations.


title: The twenty-four near-instabilities of Caspar-Klug viruses

abstract:
  Group theoretical arguments combined with normal mode analysis techniques are
applied to a coarse-grained approximation of icosahedral viral capsids which
incorporates areas of variable flexibility. This highlights a remarkable
structure of the low-frequency spectrum in this approximation, namely the
existence of a plateau of 24 near zero-modes with universal group theory
content.


title: On the non-existence of exceptional automorphisms on Shimura curves

abstract:
  We study the group of automorphisms of Shimura curves $X_0(D, N)$ attached to
an Eichler order of square-free level $N$ in an indefinite rational quaternion
algebra of discriminant $D>1$. We prove that, when the genus $g$ of the curve
is greater than or equal to 2, $\Aut (X_0(D, N))$ is a 2-elementary abelian
group which contains the group of Atkin-Lehner involutions $W_0(D, N)$ as a
subgroup of index 1 or 2. It is conjectured that $\Aut (X_0(D, N)) = W_0(D, N)$
except for finitely many values of $(D, N)$ and we provide criteria that allow
us to show that this is indeed often the case. Our methods are based on the
theory of complex multiplication of Shimura curves and the Cerednik-Drinfeld
theory on their rigid analytic uniformization at primes $p\mid D$.


title:
Numerical investigation of lenses with substructures using the
  perturbative method

abstract:
  We present a statistical study of the effects induced by substructures on the
deflection potential of dark matter halos in the strong lensing regime. This
investigation is based on the pertubative solution around the Einstein radius
(Alard 2007) in which all the information on the deflection potential is
specified by only a pair of one-dimensional functions on this ring. Using
direct comparison with ray-tracing solutions, we found that the iso-contours of
lensed images predicted by the pertubative solution is reproduced with a mean
error on their radial extension of less than 1% - in units of the Einstein
radius, for reasonable substructure masses. It demonstrates the efficiency of
the approximation to track possible signatures of substructures. We have
evaluated these two fields and studied their properties for different lens
configurations modelled either through massive dark matter halos from a
cosmological N-body simulation, or via toy models of Monte Carlo distribution
of substructures embedded in a triaxial Hernquist potential. As expected, the
angular power spectra of these two fields tend to have larger values for larger
harmonic numbers when substructures are accounted for and they can be
approximated by power-laws, whose values are fitted as a function of the
profile and the distribution of the substructures.


title: A new solution of the Schrodinger equation

abstract:
  We obtained a new solution of Schrodinger equation by the method of Euclidean
approach (Wick rotation). This is a wave motion which is fluctuating.


title: Detecting phylogenetic relations out from sparse context trees

abstract:
  The goal of this paper is to study the similarity between sequences using a
distance between the \emph{context} trees associated to the sequences. These
trees are defined in the framework of \emph{Sparse Probabilistic Suffix Trees}
(SPST), and can be estimated using the SPST algorithm. We implement the
Phyl-SPST package to compute the distance between the sparse context trees
estimated with the SPST algorithm. The distance takes into account the
structure of the trees, and indirectly the transition probabilities. We apply
this approach to reconstruct a phylogenetic tree of protein sequences in the
globin family of vertebrates. We compare this tree with the one obtained using
the well-known PAM distance.


title: Thoughts on Defining the Multiverse

abstract:
  The possibility that the multiverse corresponds to physical reality deserves
serious investigation. Having three different important theories,(quantum
mechanics, string theory and inflation), predict the existence of the
multiverse is hardly coincidental. I argue that the existence of the multiverse
must be expected from the underlying fundamental theory or else we can not
meaningfully address the puzzle of the initial conditions. In this view, the
extension of our current cosmology to a multiverse framework becomes an
extension of the Copernican principle to nature. In order to discuss the
ontology of the multiverse I propose to apply:
  - the principle of 'No Perpetual Motion' as a criterion for the parameter of
time; and,
  - the principle of 'Domains Correlations' as a criterion for determining the
background spacetime in which the multiverse is embedded.


title: Coherent Particle Transfer in an On-Demand Single-Electron Source

abstract:
  Coherent electron transfer from a localized state trapped in a quantum dot
into a ballistic conductor, taking place in on-demand electron sources, in
general may result in excitation of particle-hole pairs. We consider a simple
model for these effects, involving a resonance level with time-dependent
energy, and derive Floquet scattering matrix describing inelastic transitions
of particles in the Fermi sea. We find that, as the resonance level is driven
through the Fermi level, particle transfer may take place completely without
particle-hole excitations for certain driving protocols. In particular, such
noiseless transfer occurs when the level moves with constant rapidity, its
energy changing linearly with time. A detection scheme for studying the
coherence of particle transfer is proposed.


title:
Failure of the collinear expansion in calculation of the induced gluon
  emission

abstract:
  We demonstrate that the collinear expansion fails in the case of gluon
emission from a fast quark produced in $eA$ DIS. In this approximation the N=1
rescattering contribution to the gluon spectrum vanishes. We show that the
higher-twist approach by Guo, Wang and Zhang [4,5] based on the collinear
expansion is wrong. The nonzero gluon spectrum obtained in [4,5] is a
consequence of unjustified neglecting some important terms in the collinear
expansion.


title:
Flavor and CP conserving moduli mediated SUSY breaking in flux
  compactification

abstract:
  In certain class of flux compactification, moduli mediated supersymmetry
(SUSY) breaking preserves flavor and CP at leading order in the perturbative
expansion controlled by the vacuum expectation value of the messenger modulus.
Nevertheless there still might be dangerous flavor or CP violation induced by
higher order K\"ahler potential. We examine the constraints on such SUSY
breaking scheme imposed by low energy flavor and/or CP violating observables.
It is found that all phenomenological constraints can be satisfied even for
generic form of higher order K\"ahler potential and sparticle spectra in the
sub-TeV range, under plausible assumptions on the size of higher order
correction and flavor mixing angles. This implies for instance that mirage
mediation scheme of SUSY breaking, which involves such modulus mediation
together with an anomaly mediation of comparable size, and also the
modulus-dominated mediation realized in flux compactification can be free from
the SUSY flavor and CP problems, while giving gaugino and sfermion masses in
the sub-TeV range.


title: Network Coding Capacity of Random Wireless Networks under a SINR Model

abstract:
  Previous work on network coding capacity for random wired and wireless
networks have focused on the case where the capacities of links in the network
are independent. In this paper, we consider a more realistic model, where
wireless networks are modelled by random geometric graphs with interference and
noise. In this model, the capacities of links are not independent. By employing
coupling and martingale methods, we show that, under mild conditions, the
network coding capacity for random wireless networks still exhibits a
concentration behavior around the mean value of the minimum cut.


title:
Supercharacters of the Sylow p-subgroups of the finite symplectic and
  orthogonal groups

abstract:
  We define and study supercharacters of the classical finite unipotent groups
of symplectic and orthogonal types (over any finite field of odd
characteristic). We show how supercharacters for groups of those types can be
obtained by restricting the supercharacter theory of the finite unitriangular
group, and prove that supercharacters are orthogonal and provide a partition of
the set of all irreducible characters. We also describe all irreducible
characters of maximum degree in terms of the root system, and show how they can
be obtained as constituents of particular supercharacters.


title: Structure of wrap groups of quaternion and octonion fiber bundles

abstract:
  This article is devoted to the investigation of structure of wrap groups of
connected fiber bundles over the fields of real $\bf R$, complex $\bf C$
numbers, the quaternion skew field $\bf H$ and the octonion algebra $\bf O$.
Iterated wrap groups are studied as well. Their smashed products are
constructed.


title: Simple polytopes arising from finite graphs

abstract:
  Let $G$ be a finite graph allowing loops, having no multiple edge and no
isolated vertex. We associate $G$ with the edge polytope ${\cal P}_G$ and the
toric ideal $I_G$. By classifying graphs whose edge polytope is simple, it is
proved that the toric ideals $I_G$ of $G$ possesses a quadratic Gr\"obner basis
if the edge polytope ${\cal P}_G$ of $G$ is simple. It is also shown that, for
a finite graph $G$, the edge polytope is simple but not a simplex if and only
if it is smooth but not a simplex. Moreover, the Ehrhart polynomial and the
normalized volume of simple edge polytopes are computed.


title: Top Quark Pair Production and Properties Measurements at the Tevatron

abstract:
  The Tevatron proton-antiproton collider at Fermilab with its centre of mass
energy of 1.96 TeV is currently the only source for the production of top
quarks. This report reflects the current status of measurements of the top
quark pair production cross section and properties performed by the CDF and D0
Collaborations. Utilising datasets of up to two inverse fb, these measurements
allow unprecedented precision in probing the validity of the Standard Model.


title:
Solutions to the time-dependent Schrodinger equation in the continuous
  spectrum case

abstract:
  We generalize the Lewis-Riesenfeld technique of solving the time-dependent
Schrodinger equation to cases where the invariant has continuous eigenvalues.
An explicit formula for a generalized Lewis-Riesenfeld phase is derived in
terms of the eigenstates of the invariant. As an illustration the generalized
phase is calculated for a particle in a time-dependent linear potential.


title: Thorium-doping induced superconductivity up to 56 K in Gd1-xThxFeAsO

abstract:
  Following the discovery of superconductivity in an iron-based arsenide
LaO1-xFxFeAs with a superconducting transition temperature (Tc) of 26 K[1], Tc
was pushed up surprisingly to above 40 K by either applying pressure[2] or
replacing La with Sm[3], Ce[4], Nd[5] and Pr[6]. The maximum Tc has climbed to
55 K, observed in SmO1-xFxFeAs[7, 8] and SmFeAsO1-x[9]. The value of Tc was
found to increase with decreasing lattice parameters in LnFeAsO1-xFx (Ln stands
for the lanthanide elements) at an apparently optimal doping level. However,
the F- doping in GdFeAsO is particularly difficult[10,11] due to the lattice
mismatch between the Gd2O2 layers and Fe2As2 layers. Here we report observation
of superconductivity with Tc as high as 56 K by the Th4+ substitution for Gd3+
in GdFeAsO. The incorporation of relatively large Th4+ ions relaxes the lattice
mismatch, hence induces the high temperature superconductivity.


title: Effective Field Theory for Inflation

abstract:
  The methods of effective field theory are used to study generic theories of
inflation with a single inflaton field. For scalar modes, the leading
corrections to the ${\cal R}$ correlation function are found to be purely of
the $k$-inflation type. For tensor modes the leading corrections to the
correlation function arise from terms in the action that are quadratic in the
curvature, including a parity-violating term that makes the propagation of
these modes depend on their helicity. These methods are also briefly applied to
non-generic theories of inflation with an extra shift symmetry, as in so-called
ghost inflation.


title: Optical position meters analyzed in the non-inertial reference frames

abstract:
  In the framework of General Relativity we develop a method for analysis of
the operation of the optical position meters in their photodetectors proper
reference frames. These frames are non-inertial in general due to the action of
external fluctuative forces on meters test masses, including detectors. For
comparison we also perform the calculations in the laboratory (globally
inertial) reference frame and demonstrate that for certain optical schemes
laboratory-based analysis results in unmeasurable quantities, in contrast to
the detector-based analysis. We also calculate the response of the simplest
optical meters to weak plane gravitational waves and fluctuative motions of
their test masses. It is demonstrated that for the round-trip meter analysis in
both the transverse-traceless (TT) and local Lorentz (LL) gauges produces equal
results, while for the forward-trip meter corresponding results differ in
accordance with different physical assumptions (e.g. procedure of clocks
synchronization) implicitly underlying the construction of the TT and LL
gauges.


title: Ising and Spin orders in Iron-based Superconductors

abstract:
  Motivated by recent neutron scattering experiments, we study the ordering of
spins in the iron-based superconductors La(O_{1-x}F_x)FeAs, assuming them in
proximity to a Mott insulator in the phase diagram. The ground state of the
parent system with x = 0 is a spin density wave with ordering wave vector Q =
(0, \pi) or (\pi, 0). Upon raising the temperature, we find the system to
restore SU(2) symmetry, while an Ising symmetry remains broken, explaining the
experimentally observed lattice distortion to a monoclinic crystal structure.
Upon further temperature increase, the spins finally disorder at a second
transition. The phase transition driven by doping with charge carriers
similarly splits into an O(3) transition, and an Ising transition with z = 3 at
larger doping.


title: Non-equilibrium Luttinger liquid: Zero-bias anomaly and dephasing

abstract:
  A one-dimensional system of interacting electrons out of equilibrium is
studied in the framework of the Luttinger liquid model. We analyze several
setups and develop a theory of tunneling into such systems. A remarkable
property of the problem is the absence of relaxation in energy distribution
functions of left- and right-movers, yet the presence of the finite dephasing
rate due to electron-electron scattering, which smears zero-bias-anomaly
singularities in the tunneling density of states.


title: From nesting to dressing

abstract:
  In integrable field theories the S-matrix is usually a product of a
relatively simple matrix and a complicated scalar factor. We make an
observation that in many relativistic integrable field theories the scalar
factor can be expressed as a convolution of simple kernels appearing in the
nested levels of the nested Bethe ansatz. We formulate a proposal, up to some
discrete ambiguities, how to reconstruct the scalar factor from the nested
Bethe equations and check it for several relativistic integrable field
theories. We then apply this proposal to the AdS asymptotic Bethe ansatz and
recover the dressing factor in the integral representation of Dorey, Hofman and
Maldacena.


title: Cosmological Perturbation Theory in Slow-Roll Spacetimes

abstract:
  We present a gauge invariant argument that a nonlocal measure of second-order
metric and matter perturbations dominate that of linear fluctuations in its
effect on the gravitational field in 'slow-rolling' spacetimes.


title:
Non-flow correlations and elliptic flow fluctuations in Au+Au collisions
  at sqrt(s_NN)=200GeV

abstract:
  We present first results on event-by-event elliptic flow fluctuations in
nucleus-nucleus collisions corrected for effects of non-flow correlations where
the magnitude of non-flow correlations has been independently measured in data.
Over the measured range in centrality, we see large relative fluctuations of
25-50%. The results are consistent with predictions from both color glass
condensate and Glauber type initial condition calculations of the
event-by-event participant eccentricity fluctuations.


title: Wireless Erasure Networks with Feedback

abstract:
  Consider a lossy packet network of queues, communicating over a wireless
medium. This paper presents a throughput-optimal transmission strategy for a
unicast network when feedback is available, which has the following advantages:
It requires a very limited form of acknowledgment feedback. It is completely
distributed, and independent of the network topology. Finally, communication at
the information theoretic cut-set rate requires no network coding and no
rateless coding on the packets. This simple strategy consists of each node
randomly choosing a packet from its buffer to transmit at each opportunity.
However, the packet is only deleted from a node's buffer once it has been
successfully received by the final destination


title:
Predicting Large Hadron Collider Observations using Kazuo Kondo's Mass
  Quantum Cascade

abstract:
  The late Kazuo Kondo left a hitherto unknown a priori particle theory which
provides predictions of massive particles which may be detected by the Large
Hadron Collider (LHC). This article briefly introduces Kondo's work and
documents the derivation and masses of his expected hyper-mesons,
hyper-hadrons, heavy leptons and massive neutrinos. Several particles in these
classes may have already been detected.


title: E8(8) in Light Cone Superspace

abstract:
  We derive the non-linear action of E8(8) on the constrained chiral superfield
in the light-cone superspace with eight complex Grassmann variables. We
construct (to lowest order in the coupling) the sixteen dynamical
supersymmetries which generate a Hamiltonian with E8(8) invariance in three
space-time dimensions, and show that it has only interactions with even powers
of the coupling constant.


title:
Null structure and almost optimal local well-posedness of the
  Maxwell-Dirac system

abstract:
  We uncover the full null structure of the Maxwell-Dirac system in Lorenz
gauge. This structure, which cannot be seen in the individual component
equations, but only when considering the system as a whole, is expressed in
terms of tri- and quadrilinear integral forms with cancellations measured by
the angles between spatial frequencies. In the 3D case, we prove
frequency-localized $L^2$ space-time estimates for these integral forms at the
scale invariant regularity up to a logarithmic loss, hence we obtain almost
optimal local well-posedness of the system by iteration.


title: Anisotropic bilinear $L^2$ estimates related to the 3d wave equation

abstract:
  We first review the $L^2$ bilinear generalizations of the $L^4$ estimate of
Strichartz for solutions of the homogeneous 3D wave equation, and give a short
proof based solely on an estimate for the volume of intersection of two
thickened spheres. We then go on to prove a number of new results, the main
theme being how additional, anisotropic Fourier restrictions influence the
estimates. Moreover, we prove some refinements which are able to simultaneously
detect both concentrations and nonconcentrations in Fourier space.


title:
Three-dimensional Simulation of Magnetized Cloud Fragmentation Induced
  by Nonlinear Flows and Ambipolar Diffusion

abstract:
  We demonstrate that the formation of collapsing cores in subcritical clouds
is accelerated by nonlinear flows, by performing three-dimensional non-ideal
MHD simulations. An initial random supersonic (and trans-Alfvenic)
turbulent-like flow is input into a self-gravitating gas layer that is threaded
by a uniform magnetic field (perpendicular to the layer) such that the initial
mass-to-flux ratio is subcritical. Magnetic ambipolar diffusion occurs very
rapidly initially due to the sharp gradients introduced by the turbulent flow.
It subsequently occurs more slowly in the traditional near-quasistatic manner,
but in regions of greater mean density than present in the initial state. The
overall timescale for runaway growth of the first core(s) is several times,
10^6 yr, even though previous studies have found a timescale of several times,
10^7 yr when starting with linear perturbations and similar physical
parameters. Large-scale supersonic flows exist in the cloud and provide an
observationally testable distinguishing characteristic from core formation due
to linear initial perturbations. However, the nonlinear flows have decayed
sufficiently that the relative infall motions onto the first core are subsonic,
as in the case of starting from linear initial perturbations. The ion infall
motions are very similar to those of neutrals; however, they lag the neutral
infall in directions perpendicular to the mean magnetic field direction and
lead the neutral infall in the direction parallel to the mean magnetic field.


title: The Fibonacci Model and the Temperley-Lieb Algebra

abstract:
  We give an elementary construction of the Fibonacci model, a unitary braid
group representation that is universal for quantum computation. This paper is
dedicated to Professor C. N. Yang, on his 85-th birthday.


title: An Algorigtm for Singular Value Decomposition of Matrices in Blocks

abstract:
  Two methods to decompose block matrices analogous to Singular Matrix
Decomposition are proposed, one yielding the so called economy decomposition,
and other yielding the full decomposition. This method is devised to avoid
handling matrices bigger than the biggest blocks, so it is particularly
appropriate when a limitation on the size of matrices exists. The method is
tested on a document-term matrix (17780x3204) divided in 4 blocks, the
upper-left corner being 215x215.


title:
Efficient wave function matching approach for quantum transport
  calculations

abstract:
  The Wave Function Matching (WFM) technique has recently been developed for
the calculation of electronic transport in quantum two-probe systems. In terms
of efficiency it is comparable with the widely used Green's function approach.
The WFM formalism presented so far requires the evaluation of all the
propagating and evanescent bulk modes of the left and right electrodes in order
to obtain the correct coupling between device and electrode regions. In this
paper we will describe a modified WFM approach that allows for the exclusion of
the vast majority of the evanescent modes in all parts of the calculation. This
approach makes it feasible to apply iterative techniques to efficiently
determine the few required bulk modes, which allows for a significant reduction
of the computational expense of the WFM method. We illustrate the efficiency of
the method on a carbon nanotube field-effect-transistor (FET) device displaying
band-to-band tunneling and modeled within the semi-empirical Extended H\"uckel
theory (EHT) framework.


title: The saga of rooted staggered quarks

abstract:
  I look at the rooting controversy from a historical point of view and review
how I have come to the conclusion that these simulations involving staggered
quarks must be discarded.


title:
Volume Dependence of Spectral Weights for Unstable Particles in a
  Solvable Model

abstract:
  Volume dependence of the spectral weight is usually used as a simple criteria
to distinguish single-particle states from multi-particle states in lattice QCD
calculations. Within a solvable model, the Lee model, we show that this
criteria is in principle only valid for a stable particle or a narrow
resonance. If the resonance being studied is broad, then the volume dependence
of the corresponding spectral weight resembles that of a multi-particle state
instead of a single-particle one. For an unstable $V$-particle in the Lee
model, the transition from single-particle to multi-particle volume dependence
is governed by the ratio of its physical width to the typical level spacing in
the finite volume. We estimate this ratio for practical lattice QCD simulations
and find that, for most cases, the resonance studied in lattice QCD simulations
still resembles the single particle behavior.


title: Measurements of thermal photons in heavy ion collisions with PHENIX

abstract:
  Thermal photons are thought to be the ideal probe to measure the temperature
of the quark-gluon plasma created in heavy ion collisions. PHENIX has measured
direct photons with p_T < 5 GeV/c via their internal conversions into e+e-
pairs in Au+Au collisions at sqrt(s_NN) = 200 GeV and has now provided a
baseline measurement from p+p data.


title: A new generalization of Ostrowski type inequality on time scales

abstract:
  In this paper we first extend a generalization of Ostrowski type inequality
on time scales for functions whose derivatives are bounded and then unify
corresponding continuous and discrete versions. We also point out some
particular integral type inequalities on time scales as special cases.


title: The Limiting Distribution of Decoherent Quantum Random Walks

abstract:
  The behaviors of one-dimensional quantum random walks are strikingly
different from those of classical ones. However, when decoherence is involved,
the limiting distributions take on many classical features over time. In this
paper, we study the decoherence on both position and ``coin'' spaces of the
particle. We propose a new analytical approach to investigate these phenomena
and obtain the generating functions which encode all the features of these
walks. Specifically, from these generating functions, we find exact analytic
expressions of several moments for the time and noise dependence of position.
Moreover, the limiting position distributions of decoherent quantum random
walks are shown to be Gaussian in an analytical manner. These results
explicitly describe the relationship between the system and the level of
decoherence.


title:
AEGIS: The Nature of the Host Galaxies of Low-ionization Outflows at z <
  0.6

abstract:
  We report on a S/N-limited search for low-ionization gas outflows in the
spectra of the 0.11 < z < 0.54 objects in the EGS portion of the DEEP2 survey.
Doppler shifts from the host galaxy redshifts are systematically searched for
in the Na I 5890,96 doublet (Na D). Although the spectral resolution and S/N
limit us to study the interstellar gas kinematics from fitting a single doublet
component to each observed Na D profile, the typical outflow often seen in
local luminous-infrared galaxies (LIRGs) should be detected at >~ 6 sigma in
absorption equivalent width down to the survey limiting S/N (~ 5 per pixel) in
the continuum around Na D. The detection rate of LIRG-like outflow clearly
shows an increasing trend with star-forming activity and infrared luminosity.
However, by virtue of not selecting our sample on star formation, we also find
a majority of outflows in galaxies on the red sequence in the rest-frame (U-B,
M_B) color-magnitude diagram. Most of these red-sequence outflows are of
early-type morphology and show the sign of recent star formation in their
UV-optical colors; some show enhanced Balmer H-beta absorption lines indicative
of poststarburst as well as high dust extinction. These findings demonstrate
that outflows outlive starbursts and suggest that galactic-scale outflows play
a role in quenching star formation in the host galaxies on their way to the red
sequence. The fate of relic winds, as well as the observational constraints on
gaseous feedback models, may be studied in galaxies during their poststarburst
phase. We also note the presence of inflow candidates in red, early-type
galaxies, some with signs of AGNs/LINERs but little evidence for star
formation.


title: Potential ultra-incompressible material ReN: first-principles prediction

abstract:
  The structural, elastic and electronic properties of ReN are investigated by
first-principles calculations based on density functional theory. Two competing
structures, i.e., CsCl-like and NiAs-like structures, are found and the most
stable structure, NiAs-like, has a hexagonal symmetry which belongs to space
group P63/mmc with a=2.7472 and c=5.8180 \AA. ReN with hexagonal symmetry is a
metal ultra-incompressible solid and has less elastic anisotropy. The
ultra-incompressibility of ReN is attributed to its high valence electron
density and strong covalence bondings. Calculations of density of states and
charge density distribution, together with Mulliken atomic population analysis,
show that the bondings of ReN should be a mixture of metallic, covalent, and
ionic bondings. Our results indicate that ReN can be used as a potential
ultra-incompressible conductor. In particular, we obtain a superconducting
transition temperature T$_c$=4.8 K for ReN.


title: Optimal driving waveform for overdamped, adiabatic rocking ratchets

abstract:
  As a first step in the project of ratchet optimisation, the optimal driving
waveform among a wide class of admissible functions for an overdamped,
adiabatic rocking ratchet is shown to be dichotomous. `Optimum' is defined as
that which achieves the maximum (or minimum negative) average particle
velocity. Implications for the design of ratchets, for example in
nanotechnological transport, may follow. The main result is applicable to a
general class of adiabatic responses.


title: Dispelling the curse of the neutron skin in atomic parity violation

abstract:
  We perform calculations for the neutron skin of nuclei and its contribution
to atomic parity non-conservation (PNC) in many isotopes of Cs, Ba, Sm, Dy, Yb,
Tl, Pb, Bi, Fr, Ra. Three problems are addressed: i) Neutron-skin induced
errors to single-isotope PNC, ii) Possibility to measure neutron skin using
atomic PNC, iii) Neutron-skin induced errors for ratios of PNC effects in
different isotopes. In the latter case the correlations in the neutron skin
values for different isotopes lead to cancelations of the errors; this makes
the isotopic ratio method a competitive tool in a search for new physics beyond
the standard model.


title: Asymmetric Quantum LDPC Codes

abstract:
  Recently, quantum error-correcting codes were proposed that capitalize on the
fact that many physical error models lead to a significant asymmetry between
the probabilities for bit flip and phase flip errors. An example for a channel
which exhibits such asymmetry is the combined amplitude damping and dephasing
channel, where the probabilities of bit flips and phase flips can be related to
relaxation and dephasing time, respectively. We give systematic constructions
of asymmetric quantum stabilizer codes that exploit this asymmetry. Our
approach is based on a CSS construction that combines BCH and finite geometry
LDPC codes.