title: Measuring Form Factors and Structure Functions with CLAS

abstract:
  The physics program at the Thomas Jefferson National Accelerator Facility
includes a strong effort to measure form factors and structure functions to
probe the structure of hadronic matter, reveal the nature of confinement, and
develop an understanding of atomic nuclei using quark-gluon degrees of freedom.
The CLAS detector is a large acceptance device occupying one of the end
stations. We discuss here two programs that use CLAS; measuring the magnetic
form factor of the neutron and the virtual photon asymmetry of the proton. The
form factor has been measured with unprecedented kinematic coverage and
precision up to Q2=4.7 GeV2 and is consistent within 5%-10% of the dipole
parameterization. The proton virtual photon asymmetry has been measured across
a wide range in Bjorken x. The data exceed the SU(6)-symmetric quark prediction
and show evidence of a smooth approach to the scaling limit prescribed by
perturbative QCD.


title: The modular variety of hyperelliptic curves of genus three

abstract:
  The modular variety of non singular and complete hyperelliptic curves with
level-two structure of genus 3 is a 5-dimensional quasi projective variety
which admits several standard compactifications. The first one, X, comes from
the realization of this variety as a sub-variety of the Siegel modular variety
of level two and genus three .We will be to describe the equations of X in a
suitable projective embedding and its Hilbert function. It will turn out that
  X is normal. A further model comes from geometric invariant theory using
so-called semistable degenerated point configurations in (P^1)^8 . We denote
this GIT-compactification by Y. The equations of this variety in a suitable
projective embedding are known. This variety also can by identified with a
Baily-Borel compactified ball-quotient. We will describe these results in some
detail and obtain new proofs including some finer results for them. We have a
birational map between Y and X . In this paper we use the fact that there are
graded algebras (closely related to algebras of modular forms) A,B such that
X=proj(A) and Y=proj(B). This homomorphism rests on the theory of Thomae (19th
century), in which the thetanullwerte of hyperelliptic curves have been
computed. Using the explicit equations for $A,B$ we can compute the base locus
of the map from Y to X.
  Blowing up the base locus and the singularity of Y, we get a dominant, smooth
model {\tilde Y}. We will see that {\tilde Y} is isomorphic to the
compactification of families of marked projective lines (P^1,x_1,...,x_8),
usually denoted by {\bar M_{0,8}}. There are several combinatorial similarities
between the models X and Y. These similarities can be described best, if one
uses the ball-model to describe Y.


abstract:
  Motivated by recent experiments on Faraday waves in Bose-Einstein condensates
we investigate both analytically and numerically the dynamics of cigar-shaped
Bose-condensed gases subject to periodic modulation of the strength of the
transverse confinement. We offer a fully analytical explanation of the observed
parametric resonance, based on a Mathieu-type analysis of the non-polynomial
Schr{\"o}dinger equation. The theoretical prediction for the pattern
periodicity versus the driving frequency is directly compared with the
experimental data, yielding good qualitative and quantitative agreement between
the two. These results are corroborated by direct numerical simulations of both
the one-dimensional non-polynomial Schr{\"o}dinger equation and of the fully
three-dimensional Gross-Pitaevskii equation.


title:
Upper Limit on the Cosmic Gamma-Ray Burst Rate from High Energy Diffuse
  Neutrino Background

abstract:
  We derive upper limits on the ratio $f_{GRB/CCSN}(z) \equiv
R_{GRB}(z)/R_{CCSN}(z) \equiv f_{GRB/CCSN}(0)(1+z)^\alpha$, the ratio of the
rate, $R_{GRB}$, of long-duration Gamma Ray Bursts (GRBs) to the rate,
$R_{CCSN}$, of core-collapse supernovae (CCSNe) in the Universe ($z$ being the
cosmological redshift and $\alpha\geq 0$), by using the upper limit on the
diffuse TeV--PeV neutrino background given by the AMANDA-II experiment in the
South Pole, under the assumption that GRBs are sources of TeV--PeV neutrinos
produced from decay of charged pions produced in $p\gamma$ interaction of
protons accelerated to ultrahigh energies at internal shocks within GRB jets.
For the assumed ``concordance model'' of cosmic star formation rate, $R_{SF}$,
with $R_{CCSN}(z) \propto R_{SF}(z)$, our conservative upper limits are
$f_{GRB/CCSN}(0)\leq 5.0\times10^{-3}$ for $\alpha=0$, and $f_{GRB/CCSN}(0)\leq
1.1\times10^{-3}$ for $\alpha=2$, for example. These limits are already
comparable to (and, for $\alpha\geq 1$ already more restrictive than) the
current upper limit on this ratio inferred from other astronomical
considerations, thus providing a useful independent probe of and constraint on
the CCSN-GRB connection. Non-detection of a diffuse TeV--PeV neutrino
background by the up-coming IceCube detector in the South pole after three
years of operation, for example, will bring down the upper limit on
$f_{GRB/CCSN}(0)$ to below few $\times10^{-5}$ level, while a detection will
confirm the hypothesis of proton acceleration to ultrahigh energies in GRBs and
will potentially also yield the true rate of occurrence of these events in the
Universe.


title: Primary caustics and critical points behind a Kerr black hole

abstract:
  The primary optical caustic surface behind a Kerr black hole is a four-cusped
tube displaced from the line of sight. We derive the caustic surface in the
nearly asymptotic region far from the black hole through a Taylor expansion of
the lightlike geodesics up to and including fourth-order terms in m/b and a/b,
where $m$ is the black hole mass, a the spin and b the impact parameter. The
corresponding critical locus in the observer's sky is elliptical and a
point-like source inside the caustics will be imaged as an Einstein cross. With
regard to lensing near critical points, a Kerr lens is analogous to a circular
lens perturbed by a dipole and a quadrupole potential. The caustic structure of
the supermassive black hole in the Galactic center could be probed by lensing
of low mass X-ray binaries in the Galactic inner regions or by hot spots in the
accretion disk.


title: Spin-Torque Driven Magnetization Dynamics: Micromagnetic Modelling

abstract:
  In this paper we present an overview of recent progress made in the
understanding of the spin-torque induced magnetization dynamics in nanodevices
using mesoscopic micromagnetic simulations. We first specify how a spin-torque
term may be added to the usual Landau-Lifshitz-Gilbert equation of
magnetization motion and detail its physical meaning. After a brief description
of spin-torque driven dynamics in the macrospin approximation, we discuss the
validity of this approximation for various experimentally relevant geometries.
Next, we perform a detailed comparison between accurate experimental data
obtained from nanopillar devices and corresponding numerical modelling. We show
that, on the one hand, many qualitatively important features of the observed
magnetization dynamics (e.g., non-linear frequency shift and frequency jumps
with increasing current) can be satisfactory explained by sophisticated
micromagnetic models, but on the other hand, understanding of these experiments
is still far from being complete. We proceed with the numerical analysis of
point-contact experiments, where an even more complicated magnetization
dynamics is observed. Simulations reveal that such a rich behaviour is due to
the formation of several strongly non-linear oscillation modes. In the last
part of the paper we emphasize the importance of sample characterization and
conclude with some important remarks concerning the relation between
micromagnetic modelling and real experiments.


title: The nature of the Lambda(1405)

abstract:
  We present here some results supporting the nature of the $\Lambda(1405)$
resonance as dynamically generated from the meson baryon interaction in coupled
channels and resulting from the superposition of two close-by poles. We find
support for this picture in the $K^- p \to \pi^0 \pi^0 \Sigma^0 $ reaction,
which shows a different shape than the one obtained from the $\pi ^- p \to K^0
\pi \Sigma $ reaction. We also call the attention to the $K^- p \to \gamma \pi
\Sigma$ with $\pi \Sigma$ in the $\Lambda(1405)$ region, which shows a narrow
peak in the calculations around 1420 MeV. We also report on recent calculations
of the radiative decay of the two $\Lambda(1405)$ states and on reactions to
obtain information on these decay modes. Finally, we present results for the
$pp\to p K^+\Lambda(1405)$ reaction recently measured at ANKE/COSY and compare
them with theoretical results.


title: Mod 2 cohomology of 2-local finite groups of low rank

abstract:
  We determine the mod $2$ cohomology over the Steenrod algebra of the
classifying spaces of the free loop groups $LG$ for compact groups $G=Spin(7)$,
$Spin(8)$, $Spin(9)$, and $F_4$. Then, we show that they are isomorphic as
algebras over the Steenrod algebra to the mod $2$ cohomology of the
corresponding Chevalley groups of type $G(q)$, where $q$ is an odd prime power.
In a similar manner, we compute the cohomology of the free loop space over
$BDI(4)$ and show that it is isomorphic to that of $BSol(q)$ as algebras over
the Steenrod algebra.


title:
Circular polarimetry reveals helical magnetic fields in the young
  stellar object HH 135-136

abstract:
  Magnetic fields are believed to have a vital role in regulating and shaping
the flow of material onto and away from protostars during their initial mass
accretion phase. It is becoming increasingly accepted that bipolar outflows are
generated and collimated as material is driven along magnetic field lines and
centrifugally accelerated off a rotating accretion disk. However, the precise
role of the magnetic field is poorly understood and evidence for its shape and
structure has not been forthcoming. Here we report imaging circular polarimetry
in the near-infrared and Monte Carlo modelling showing that the magnetic field
along the bipolar outflow of the HH 135-136 young stellar object is helical.
The field retains this shape for large distances along the outflow, so the
field structure can also provide the necessary magnetic pressure for
collimation of the outflow. This result lends further weight to the hypothesis
- central to any theory of star formation - that the outflow is an important
instrument for the removal of high-angular-momentum material from the accretion
disk, thereby allowing the central protostar to increase its mass.


title: Relations Between Standard Model Parameters from $T^{'}$ Flavor Symmetry

abstract:
  Spontaneously broken flavor symmetry involving the binary tetrahedral group
$T^{'}$ relates parameters in the standard model. In one example the CP
violating Pontecorvo-Maki-Nakagawa-Sakata phase $\delta_{PMNS}$ and atmospheric
mixing angle $\theta_{23}$ of neutrinos are related to the Cabibbo mixing angle
$\Theta_C$ for quarks. A second formula relates a ratio of neutrino mass
eigenvalues to the Cabibbo angle.


title: Recent Results in Bottomonium / Ties to Charmonium

abstract:
  Recent results in studies of bottomonium especially relevant to charmonium
are reviewed. This report covers dipion transition matrix elements, $\eta$
production in $\Upsilon$ transitions, $\Upsilon$ decays to invisible particles,
a search for a non-standard-model pseudoscalar Higgs in $\Upsilon$ radiative
decays, and $\Upsilon$ radiative decays to $\rm{f_2(1270)}$, $\eta$, and
$\eta'$.


title: Quantifying the decay of quantum properties in single-mode states

abstract:
  The dissipative dynamics of Gaussian squeezed states (GSS) and coherent
superposition states (CSS) are analytically obtained and compared. Time scales
for sustaining different quantum properties such as squeezing, negativity of
the Wigner function or photon number distribution are calculated. Some of these
characteristic times also depend on initial conditions. For example, in the
particular case of squeezing, we find that while the squeezing of CSS is only
visible for small enough values of the field intensity, in GSS it is
independent of this quantity, which may be experimentally advantageous. The
asymptotic dynamics however is quite similar as revealed by the time evolution
of the fidelity between states of the two classes.


title: Free Bessel laws

abstract:
  We introduce and study a remarkable family of real probability measures
$\pi_{st}$, that we call free Bessel laws. These are related to the free
Poisson law $\pi$ via the formulae $\pi_{s1}=\pi^{\boxtimes s}$ and
$\pi_{1t}=\pi^{\boxplus t}$. Our study includes: definition and basic
properties, analytic aspects (supports, atoms, densities), combinatorial
aspects (functional transforms, moments, partitions), and a discussion of the
relation with random matrices and quantum groups.


title: Simulating elliptic flow with viscous hydrodynamics

abstract:
  In this work we simulate a viscous hydrodynamical model of non-central Au-Au
collisions in 2+1 dimensions, assuming longitudinal boost invariance. The model
fluid equations were proposed by \"{O}ttinger and Grmela \cite{OG}. Freezeout
is signaled when the viscous corrections become large relative to the ideal
terms. Then viscous corrections to the transverse momentum and differential
elliptic flow spectra are calculated. When viscous corrections to the thermal
distribution function are not included, the effects of viscosity on elliptic
flow are modest. However, when these corrections are included, the elliptic
flow is strongly modified at large $p_T$. We also investigate the stability of
the viscous results by comparing the non-ideal components of the stress tensor
($\pi^{ij}$) and their influence on the $v_2$ spectrum to the expectation of
the Navier-Stokes equations ($\pi^{ij} = -\eta \llangle \partial_i u_j
\rrangle$). We argue that when the stress tensor deviates from the
Navier-Stokes form the dissipative corrections to spectra are too large for a
hydrodynamic description to be reliable. For typical RHIC initial conditions
this happens for $\eta/s \gsim 0.3$.


title:
Three-body description of direct nuclear reactions: Comparison with the
  continuum discretized coupled channels method

abstract:
  The continuum discretized coupled channels (CDCC) method is compared to the
exact solution of the three-body Faddeev equations in momentum space. We
present results for: i) elastic and breakup observables of d-12C at E_d=56 MeV,
ii) elastic scattering of d-58Ni at E_d=80 MeV, and iii) elastic, breakup and
transfer observables for 11Be+p at E_{11Be}/A=38.4 MeV. Our comparative studies
show that, in the first two cases, the CDCC method is a good approximation to
the full three-body Faddeev solution, but for the 11Be exotic nucleus,
depending on the observable or the kinematic regime, it may miss out some of
the dynamic three-body effects that appear through the explicit coupling to the
transfer channel.


title: Dynamic of threshold solutions for energy-critical wave equation

abstract:
  We consider the energy-critical non-linear focusing wave equation in
dimension N=3,4,5. An explicit stationnary solution, $W$, of this equation is
known. The energy E(W,0) has been shown by C. Kenig and F. Merle to be a
threshold for the dynamical behavior of solutions of the equation. In the
present article we study the dynamics at the critical level E(u_0,u_1)=E(W,0)
and classify the corresponding solutions. We show in particular the existence
of two special solutions, connecting different behaviors for negative and
positive times. Our results are analoguous to our previous work on radial
Schr\"odinger equation, but without any radial assumption on the data. We also
refine the understanding of the dynamical behavior of the special solutions.


title: On Optimality Properties of the Shiryaev-Roberts Procedure

abstract:
  We consider the simple changepoint problem setting, where observations are
independent, iid pre-change and iid post-change, with known pre- and
post-change distributions. The Shiryaev-Roberts detection procedure is known to
be asymptotically minimax in the sense of minimizing maximal expected detection
delay subject to a bound on the average run length to false alarm, as the
latter goes to infinity. Here we present other optimality properties of the
Shiryaev-Roberts procedure.


title:
Mechanical Design, Control Choices and first Return of Use of a
  Prosthetic Arm

abstract:
  In the world of upper limb prostheses, few companies dominate the majority of
the market. They propose different kinds of hand, wrist and elbow prostheses
but their control is often difficult to understand by the patients. We have
decided to develop new myoelectric prosthetic arm (elbow, wrist and hand) by
axing our development on the use of new technologies and facility of use for
the patient. In this paper, we are explaining in details the different kinds of
prostheses currently proposed to the amputees, their advantages and their
drawbacks, the descriptions of the patients' needs and the possible
improvements of the product. We will develop the designing choices of our
prosthesis and the movements it can realize. Then we will explain the
simplified control of the product by the patient and its first reactions.
Finally, we will conclude by the news ideas and the next researches to
concretize.


title: Charge Density Wave Driven Ferromagnetism in the Periodic Anderson Model

abstract:
  We demonstrate the existence of ferromagnetism in the Periodic Anderson Model
(PAM) at conduction-band filling near a quarter. We show that this
ferromagnetism is not supported by Ruderman-Kittel-Kasuya-Yosida (RKKY)
interactions but is instead driven by the precursors of charge density wave
(CDW) formation in the conduction electron band. To study the effect of spatial
correlations, we compare Dynamical Mean field Approximation (DMFA) and
Dynamical Cluster Approximation (DCA) results. We find that both RKKY and CDW
driven ferromagnetism persist as short-range correlations are incorporated into
the theory. Both DMFA and DCA show the precursors of CDW formation through the
strong enhancement of the d-electron CDW susceptibility as the temperature
decreases, up to the ferromagnetic transition temperature. In addition, the DCA
captures the signal of a band gap opening due to Peierls instability.


title: SPITZER SAGE Observations of Large Magellanic Cloud Planetary Nebulae

abstract:
  We present IRAC and MIPS images and photometry of a sample of previously
known planetary nebulae (PNe) from the SAGE survey of the Large Magellanic
Cloud (LMC) performed with the Spitzer Space Telescope. Of the 233 known PNe in
the survey field, 185 objects were detected in at least two of the IRAC bands,
and 161 detected in the MIPS 24 micron images. Color-color and color-magnitude
diagrams are presented using several combinations of IRAC, MIPS, and 2MASS
magnitudes. The location of an individual PN in the color-color diagrams is
seen to depend on the relative contributions of the spectral components which
include molecular hydrogen, polycyclic aromatic hydrocarbons (PAHs), infrared
forbidden line emission from the ionized gas, warm dust continuum, and emission
directly from the central star. The sample of LMC PNe is compared to a number
of Galactic PNe and found to not significantly differ in their position in
color-color space. We also explore the potential value of IR PNe luminosity
functions (LFs) in the LMC. IRAC LFs appear to follow the same functional form
as the well-established [O III] LFs although there are several PNe with
observed IR magnitudes brighter than the cut-offs in these LFs.


title: Geometric Endoscopy and Mirror Symmetry

abstract:
  The geometric Langlands correspondence has been interpreted as the mirror
symmetry of the Hitchin fibrations for two dual reductive groups. This mirror
symmetry, in turn, reduces to T-duality on the generic Hitchin fibers, which
are smooth tori. In this paper we study what happens when the Hitchin fibers on
the B-model side develop orbifold singularities. These singularities correspond
to local systems with finite groups of automorphisms. In the classical
Langlands Program local systems of this type are called endoscopic. They play
an important role in the theory of automorphic representations, in particular,
in the stabilization of the trace formula. Our goal is to use the mirror
symmetry of the Hitchin fibrations to expose the special role played by these
local systems in the geometric theory. The study of the categories of A-branes
on the dual Hitchin fibers allows us to uncover some interesting phenomena
associated with the endoscopy in the geometric Langlands correspondence. We
then follow our predictions back to the classical theory of automorphic
functions. This enables us to test and confirm them. The geometry we use is
similar to that which is exploited in recent work by B.-C. Ngo, a fact which
could be significant for understanding the trace formula.


title:
Classification of the virtually cyclic subgroups of the pure braid
  groups of the projective plane

abstract:
  We classify the (finite and infinite) virtually cyclic subgroups of the pure
braid groups $P_{n}(RP^2)$ of the projective plane. The maximal finite
subgroups of $P_{n}(RP^2)$ are isomorphic to the quaternion group of order 8 if
$n=3$, and to $\Z_{4}$ if $n\geq 4$. Further, for all $n\geq 3$, up to
isomorphism, the following groups are the infinite virtually cyclic subgroups
of $P_{n}(RP^2)$: $\Z$, $\Z_{2} \times \Z$ and the amalgamated product $\Z_{4}
\ast_{\Z_{2}} \Z_{4}$.


title:
Impact of a finite cut-off for the optical sum rule in the
  superconducting state

abstract:
  A single band optical sum rule derived by Kubo can reveal a novel kind of
superconducting state. It relies, however, on a knowledge of the single band
contribution from zero to infinite frequency. A number of experiments over the
past five years have used this sum rule; their data has been interpreted in
support of 'kinetic energy-driven superconductivity'. However, because of the
presence of unwanted interband optical spectral weight, they necessarily have
to truncate their sum at a finite frequency. This work examines theoretical
models where the impact of this truncation can be examined first in the normal
state, and then in the superconducting state. The latter case is particularly
important as previous considerations attributed the observed anomalous
temperature dependence as an artifact of a non-infinite cutoff frequency. We
find that this is in fact not the case, and that the sign of the corrections
from the use of a non-infinite cutoff is such that the observed temperature
dependence is even more anomalous when proper account is taken of the cutoff.
On the other hand, in these same models, we find that the strong observed
temperature dependence in the normal state can be attributed to the effect of a
non-infinite cutoff frequency.


title: Lectures on the stable homotopy of BG

abstract:
  This paper is a survey of the stable homotopy theory of BG for G a finite
group. It is based on a series of lectures given at the Summer School
associated with the Topology Conference at the Vietnam National University,
Hanoi, August 2004.


title:
On quantum capacity of erasure channel assisted by back classical
  communication

abstract:
  We present a communication protocol for the erasure channel assisted by
backward classical communication, which achieves a significantly better rate
than the best prior result. In addition, we prove an upper bound for the
capacity of the channel. The upper bound is smaller than the capacity of the
erasure channel when it is assisted by two-way classical communication. Thus,
we prove the separation between quantum capacities assisted by backward
classical communication and two-way classical communication.


title: Some new characterizations of Banach spaces containing $\ell^1$

abstract:
  Several new characterizations of Banach spaces containing a subspace
isomorphic to $\ell^1$, are obtained. These are applied to the question of when
$\ell^1$ embeds in the injective tensor product of two Banach spaces.


title: Objective and Subjective Probabilities in Quantum Mechanics

abstract:
  The concept of probability was prominent in the original foundations of
quantum mechanics, and continues to be so today. Indeed, the controversies
regarding objective and subjective interpretations of probability have again
become active. I argue that, although both objective and subjective
probabilities have domains of relevance in QM, their roles are quite distinct.
Even where both are legitimate, the objective and subjective probabilities
differ, both conceptually and numerically. There are quantum probabilities that
have no useful subjective interpretations, and there are subjective
probabilities that cannot be realized as quantum probabilities.


title: The Varied Fates of z~2 Star-forming Galaxies

abstract:
  Star-forming galaxies constitute the majority of galaxies with stellar masses
>10^10 M_Sun/h^2 at z~2 and dominate the star-formation rate density of the
Universe at this early epoch. It is thus critical to understand their origins,
evolution, and connection to the underlying dark matter distribution. To this
end, we identify the dark matter halos (including subhalos) that are likely to
contain star-forming galaxies at z~2 (z2SFGs) within a large dissipationless
cosmological simulation and then use halo merger histories to follow the
evolution of z2SFG descendants to z~1 and z~0. The evolved halos at these
epochs are then confronted with an array of observational data in order to
uncover the likely descendants of z2SFGs. Though the evolved halos have
clustering strengths comparable to red galaxies at z~1 and z~0, we find that
the bulk of z2SFGs do not evolve into red galaxies, at either epoch. This
conclusion is based primarily on the fact that the space density of z2SFGs is
much higher than that of lower redshift red galaxies, even when accounting for
the merging of z2SFG descendants, which decreases the number density of z2SFG
descendants by at most a factor of two by z~0. Of the ~50% of z2SFGs that
survive to z~0, ~70% reside at the center of z~0 dark matter halos with M>10^12
M_Sun/h. Halo occupation modeling of z~0 galaxies suggests that such halos are
occupied by galaxies with M_r<-20.5, implying that these z2SFGs evolve into
``typical'' ~ L* galaxies today, including our own Galaxy. The remaining ~30%
become satellite galaxies by z~0, and comparison to halo occupation modeling
suggests that they are rather faint, with M_r<-19.5. (ABRIDGED)


title:
XMM-Newton Detection of a Compton-thick AGN in the 1-Jy ULIRG/LINER
  F04103-2838

abstract:
  We report on the detection of Fe Kalpha emission in F04103$-$2838, an
ultraluminous infrared galaxy (ULIRG; log[L$_{\rm IR}$/L$_\odot$] $\ge$ 12)
that is optically classified as a LINER. Previous {\it Chandra} observations
suggested the presence of both a starburst and an AGN in this source. A deeper
($\sim$20 ksec) {\it XMM-Newton} spectrum reveals an Fe Kalpha line at rest
frame energy $\sim$6.4 keV, consistent with cold neutral iron. The best-fit
spectral model indicates the Fe Kalpha line has an equivalent width of
$\sim$1.6 keV. The hard X-ray emission is dominated by a Compton-thick AGN with
intrinsic 0.2--10 keV luminosity $\sim10^{44}$ ergs s$^{-1}$, while the soft
X-ray emission is from $\sim$0.1 keV gas attributed to the starburst. The X-ray
spectrum of this source bears a striking resemblance to that of the archetypal
luminous infrared galaxy NGC 6240 despite differences in merger state and
infrared properties.


title: Boltzmann transport and residual conductivity in bilayer graphene

abstract:
  A Drude-Boltzmann theory is used to calculate the transport properties of
bilayer graphene. We find that for typical carrier densities accessible in
graphene experiments, the dominant scattering mechanism is overscreened Coulomb
impurities that behave like short-range scatterers. We anticipate that the
conductivity $\sigma(n)$ is linear in $n$ at high density and has a plateau at
low density corresponding to a residual density of $n^* = \sqrt{n_{\rm imp}
{\tilde n}}$, where ${\tilde n}$ is a constant which we estimate using a
self-consistent Thomas-Fermi screening approximation to be ${\tilde n} \approx
0.01 ~q_{\rm TF}^2 \approx 140 \times 10^{10} {\rm cm}^{-2}$. Analytic results
are derived for the conductivity as a function of the charged impurity density.
We also comment on the temperature dependence of the bilayer conductivity.


title: A "Domain Wall" Scenario for the AdS/QCD

abstract:
  We propose a scenario for bottom-up gravity dual picture of QCD-like
theories, which consists of two near-AdS$_5$ domains separated by the ``domain
wall'' at which the effective coupling relatively rapidly switches from small
perturbative value at its UV side to strong at its IR side. Its consequence are
corresponding jumps in 5-d masses of the bulk fields, related to different
anomalous dimensions of the corresponding operators. Inclusion of both weakly
and strongly coupled parts of bulk wave functions allows for consistent
inclusion of QCD hard processes.
  We further discuss how transitions from strong to weak coupling in hard
observables should look like, exemplified by pion diffractive dissociation,
which seems to show this transition experimentally. Then we propose a dynamical
mechanism for this jump related to instantons, which are point-like bulk
objects located at/near the domain wall. We further argue that in the limit of
large number of colors $N_c\to\infty$ the "domain wall" is becoming a true
singularity. Instanton-induced contributions to correlators and partition
function of the instanton ensemble is reformulated in the $AdS_5$ language.
Among other applications are lowest mesons as collective vibrations of the
``domain wall''.


title:
The Far Ultraviolet Spectroscopic Explorer Survey of OVI Absorption in
  the Disk of the Milky Way

abstract:
  To probe the distribution and physical characteristics of interstellar gas at
temperatures T ~ 3e5 K in the disk of the Milky Way, we have used the Far
Ultraviolet Spectroscopic Explorer (FUSE) to observe absorption lines of OVI
toward 148 early-type stars situated at distances 1 kpc. After subtracting off
a mild excess of OVI arising from the Local Bubble, combining our new results
with earlier surveys of OVI, and eliminating stars that show conspicuous
localized X-ray emission, we find an average OVI mid-plane density n_0 = 1.3e-8
cm^-3. The density decreases away from the plane of the Galaxy in a way that is
consistent with an exponential scale height of 3.2 kpc at negative latitudes or
4.6 kpc at positive latitudes. Average volume densities of OVI along different
sight lines exhibit a dispersion of about 0.26 dex, irrespective of the
distances to the target stars. This indicates that OVI does not arise in
randomly situated clouds of a fixed size and density, but instead is
distributed in regions that have a very broad range of column densities, with
the more strongly absorbing clouds having a lower space density. Line widths
and centroid velocities are much larger than those expected from differential
Galactic rotation, but they are nevertheless correlated with distance and
N(OVI), which reinforces our picture of a diverse population of hot plasma
regions that are ubiquitous over the entire Galactic disk. The velocity
extremes of the OVI profiles show a loose correlation with those of very strong
lines of less ionized species, supporting a picture of a turbulent, multiphase
medium churned by shock-heated gas from multiple supernova explosions.


title: Schrodinger Picture of Quantum Gravitational Collapse

abstract:
  The functional Schrodinger equation is used to study the quantum collapse of
a gravitating, spherical domain wall and a massless scalar field coupled to the
metric. The approach includes backreaction of pre-Hawking radiation on the
gravitational collapse. Truncating the degrees of freedom to a minisuperspace
leads to an integro-differential Schrodinger equation. We define a "black hole"
operator and find its eigenstates. The black hole operator does not commute
with the Hamiltonian, leading to an energy-black holeness uncertainty relation.
We discuss energy eigenstates and also obtain a partial differential equation
for the time-dependent gravitational collapse problem.


title:
Fundamental Physical Processes in Coronae: Waves, Turbulence,
  Reconnection, and Particle Acceleration

abstract:
  Our understanding of fundamental processes in the solar corona has been
greatly progressed based on the space observations of SMM, Yohkoh, Compton GRO,
SOHO, TRACE, RHESSI, and STEREO. We observe now acoustic waves, MHD
oscillations, turbulence-related line broadening, magnetic configurations
related to reconnection processes, and radiation from high-energy particles on
a routine basis. We review a number of key observations in EUV, soft X-rays,
and hard X-rays that innovated our physical understanding of the solar corona,
in terms of hydrodynamics, MHD, plasma heating, and particle acceleration
processes.


title: Positronium-ion decay

abstract:
  We present a precise theoretical prediction for the decay width of the bound
state of two electrons and a positron (a negative positronium ion), Gamma(Ps^-)
= 2.087 085(12)/ns. We include O(alpha^2) effects of hard virtual photons as
well as soft corrections to the wave function and the decay amplitude. An
outcome of a large-scale variational calculation, this is the first result for
second-order corrections to a decay of a three-particle bound state. It will be
tested experimentally in the new positronium-ion facility in Garching in
Germany.


title:
Interference Between Competing Pathways in the Interaction of
  Three-Level Ladder Atoms and Radiation

abstract:
  In this paper we explore the physical origin of the transparency induced in
absorbing three-level cascade atoms by the simultaneous interplay of two
coherent beams of light. By utilizing the scattering technique we offer what we
believe is a very convincing physical evidence for the existence, or for the
absence, of quantum interference effects in the Autler-Townes (AT) and
Electromagnetically Induced Transparency (EIT) phenomena.


title: Diameter-dependent thermopower of Bi nanowires

abstract:
  We present a study of electronic transport in individual Bi nanowires of
large diameter relative to the Fermi wavelength. Measurements of the resistance
and thermopower of intrinsic and Sn-doped Bi wires with various wire diameters,
ranging from 150-480 nm, have been carried out over a wide range of
temperatures (4-300 K) and magnetic fields (0-14 T). We find that the
thermopower of intrinsic Bi wires in this diameter range is positive (type-p)
below about 150 K, displaying a peak at around 40 K. In comparison, intrinsic
bulk Bi is type-n. Magneto-thermopower effects due to the decrease of surface
scattering when the cyclotron diameter is less than the wire diameter are
demonstrated. The measurements are interpreted in terms of a model of diffusive
thermopower, where the mobility limitations posed by hole-boundary scattering
are much less severe than those due to electron-hole scattering.


title:
Homology of the curve complex and the Steinberg module of the mapping
  class group

abstract:
  By the work of Harer, the reduced homology of the complex of curves is a
fundamental cohomological object associated to all torsion free finite index
subgroups of the mapping class group. We call this homology group the Steinberg
module of the mapping class group. It was previously known that the curve
complex has the homotopy type of a bouquet of spheres. Here, we give the first
explicit homologically nontrivial sphere in the curve complex and show that
under the action of the mapping class group, the orbit of this homology class
generates the reduced homology of the curve complex.


title:
Stringy Generalization of the First Law of Thermodynamics for Rotating
  BTZ Black Hole with a Cosmological Constant as State Parameter

abstract:
  In this paper we will show that using the cosmological constant as a new
thermodynamical state variable, the differential and integral mass formulas of
the first law of thermodynamics for asymptotic flat spacetimes can be extended
to be used at the two horizons of the (2+1) dimensional BTZ black hole. We also
extend this equations to the stringy description of the BTZ black hole, in
which two new systems that resemble the right and left modes of effective
string theory, are defined in terms of the inner and outer horizons.


title:
Optimal Concentration for SU(1,1) Coherent State Transforms and an
  analogue of the Lieb-Wehrl Conjecture for SU(1,1)

abstract:
  We derive a lower bound for the Wehrl entropy in the setting of SU(1,1). For
asymptotically high values of the quantum number k, this bound coincides with
the analogue of the Lieb-Wehrl conjecture for SU(1,1) coherent states. The
bound on the entropy is proved via a sharp norm bound. The norm bound is
deduced by using an interesting identity for Fisher information of SU(1,1)
coherent state transforms and a new family of sharp Sobolev inequalities on the
hyperbolic plane. To prove the sharpness of our Sobolev inequality, we need to
first prove a uniqueness theorem for solutions of a semi-linear Poisson
equation (which is actually the Euler-Lagrange equation for the variational
problem associated with our sharp Sobolev inequality) on the hyperbolic plane.
Uniqueness theorems proved for similar semi-linear equations in the past do not
apply here and the new features of our proof are of independent interest, as
are some of the consequences we derive from the new family of Sobolev
inequalities.


title: Quantum loop models and the non-abelian toric code

abstract:
  I define quantum loop models whose degrees of freedom are Ising spins on the
square lattice as in the toric code, but where the excitations should have
non-abelian statistics. The inner product is topological, allowing a direct
implementation of the anyonic fusion matrix on the lattice. It also makes
deconfined anyons possible for a variety of values of the weight per loop $d$
in the ground state. For d=\sqrt{2}, a gapped non-abelian topological phase can
occur with only four-spin interactions.


title:
Electric dipole-forbidden nuclear transitions driven by super-intense
  laser fields

abstract:
  Electric dipole-forbidden transitions of nuclei interacting with
super-intense laser fields are investigated considering stable isotopes with
suitable low-lying first excited states. Different classes of transitions are
identified, and all magnetic sublevels corresponding to the near-resonantly
driven nuclear transition are included in the description of the nuclear
quantum system. We find that large transition matrix elements and convenient
resonance energies qualify nuclear M1 transitions as good candidates for the
coherent driving of nuclei. We discuss the implications of resonant interaction
of intense laser fields with nuclei beyond the dipole approximation for the
controlled preparation of excited nuclear states and important aspects of
possible experiments aimed at observing these effects.


title: Tutte chromatic identities from the Temperley-Lieb algebra

abstract:
  This paper introduces a conceptual framework, in the context of quantum
topology and the algebras underlying it, for analyzing relations obeyed by the
chromatic polynomial \chi(Q) of planar graphs. Using it we give new proofs and
substantially extend a number of classical results concerning the combinatorics
of the chromatic polynomial. In particular, we show that Tutte's golden
identity is a consequence of level-rank duality for SO(N) topological quantum
field theories and Birman-Murakami-Wenzl algebras. This identity is a
remarkable feature of the chromatic polynomial relating \chi({\phi+2}) for any
triangulation of the sphere to (\chi({\phi+1}))^2 for the same graph, where
\phi denotes the golden ratio. The new viewpoint presented here explains that
Tutte's identity is special to these values of the parameter Q. A natural
context for analyzing such properties of the chromatic polynomial is provided
by the {\em chromatic algebra}, whose Markov trace is the chromatic polynomial
of an associated graph. We use it to show that another identity of Tutte's for
the chromatic polynomial at Q={\phi}+1 arises from a Jones-Wenzl projector in
the Temperley-Lieb algebra. We generalize this identity to each value Q=
2+2\cos(2\pi j/(n+1)) for j< n positive integers. When j=1, these Q are the
Beraha numbers, where the existence of such identities was conjectured by
Tutte. We present a recursive formula for this sequence of chromatic polynomial
relations.

categories: math.CO cond-mat.stat-mech math.GT math.QA


title:
On fractional Brownian motion limits in one dimensional nearest-neighbor
  symmetric simple exclusion

abstract:
  A well-known result with respect to the one dimensional nearest-neighbor
symmetric simple exclusion process is the convergence to fractional Brownian
motion with Hurst parameter 1/4, in the sense of finite-dimensional
distributions, of the subdiffusively rescaled current across the origin, and
the subdiffusively rescaled tagged particle position.
  The purpose of this note is to improve this convergence to a functional
central limit theorem, with respect to the uniform topology, and so complete
the solution to a conjecture in the literature with respect to simple exclusion
processes.


title: Flux-dominated solar dynamo model with a thin shear layer

abstract:
  Flux-dominated solar dynamo models have demonstrated to reproduce the main
features of the large scale solar magnetic cycle, however the use of a solar
like differential rotation profile implies in the the formation of strong
toroidal magnetic fields at high latitudes where they are not observed. In this
work, we invoke the hypothesis of a thin-width tachocline in order to confine
the high-latitude toroidal magnetic fields to a small area below the overshoot
layer, thus avoiding its influence on a Babcock-Leighton type dynamo process.
Our results favor a dynamo operating inside the convection zone with a
tachocline that essentially works as a storage region when it coincides with
the overshoot layer.


title: X-ray properties of an Unbiased Hard X-ray Detected Sample of AGN

abstract:
  The SWIFT gamma ray observatory's Burst Alert Telescope (BAT) has detected a
sample of active galactic nuclei (AGN) based solely on their hard X-ray flux
(14-195 keV). In this paper, we present for the first time {\it XMM-Newton}
X-ray spectra for 22 BAT AGNs with no previously analyzed X-ray spectra. If our
sources are a representative sample of the BAT AGN, as we claim, our results
present for the first time global X-ray properties of an unbiased towards
absorption (n$_H < 3 \times 10^{25}$ cm$^{-2}$), local ($<z> = 0.03$), AGN
sample. We find 9/22 low absorption (n$_H < 10^{23}$ cm$^{-2}$), simple power
law model sources, where 4 of these sources have a statistically significant
soft component. Among these sources, we find the presence of a warm absorber
statistically significant for only one Seyfert 1 source, contrasting with the
ASCA results of \citet{rey97} and \citet{geo98}, who find signatures of warm
absorption in half or more of their Seyfert 1 samples at similar redshifts.
Additionally, the remaining sources (14/22) have more complex spectra, well-fit
by an absorbed power law at $E > 2.0$ keV. Five of the complex sources are
classified as Compton-thick candidates. Further, we find four more sources with
properties consistent with the hidden/buried AGN reported by Ueda {\it et al.}
(2007). Finally, we include a comparison of the {\it XMM-Newton} EPIC spectra
with available SWIFT X-ray Telescope (XRT) observations. From these
comparisons, we find 6/16 sources with varying column densities, 6/16 sources
with varying power law indices, and 13/16 sources with varying fluxes, over
periods of hours to months. Flux and power law index are correlated for objects
where both parameters vary.


title: Aspects of nonmetricity in gravity theories

abstract:
  In this work, we show that a class of metric-affine gravities can be reduced
to a Riemann-Cartan one. The reduction is based on the cancelation of the
nonmetricity against the symmetric components of the spin connection. A
heuristic proof, in the Einstein-Cartan formalism, is performed in the special
case of diagonal unitary tangent metric tensor. The result is that the
nonmetric degrees of freedom decouple from the geometry. Thus, from the point
of view of isometries on the tangent manifold, the equivalence might be viewed
as an isometry transition from the affine group to the Lorentz group,
$A(d,\mathbb{R})\longmapsto SO(d)$. Furthermore, in this transition, depending
on the form of the starting action, the nonmetricity degrees might present a
dynamical matter field character, with no geometric interpretation in the
Riemann-Cartan geometry.


title: Baryon masses with improved staggered quarks

abstract:
  The MILC collaboration's simulations with improved staggered quarks are being
extended with runs at a lattice spacing of 0.06 fm with quark masses down to
one tenth the strange quark mass. We give a brief introduction to these new
simulations and the determination of the lattice spacing. Then we combine these
new runs with older results to study the masses of the nucleon and the Omega
minus in the continuum and chiral limits.


title: Natural inflation in 5D warped backgrounds

abstract:
  In light of the five-year data from the Wilkinson Microwave Anisotropy Probe
(WMAP), we discuss models of inflation based on the pseudo Nambu-Goldstone
potential predicted in five-dimensional gauge theories for different
backgrounds: flat Minkowski, anti-de Sitter, and dilatonic spacetime. In this
framework, the inflaton potential is naturally flat due to shift symmetries and
the mass scales associated with it are related to 5D geometrical quantities.


title: On the phase diagram of QCD at finite isospin density

abstract:
  Using a canonical formalism, we determine the equation of state and the phase
diagram of eight-flavour QCD, as a function of temperature and isospin density.
Two mechanisms are at work: Bose condensation of pions at high density, and
deconfinement at high temperature. We study their interplay and find that on
our small and coarse lattice the first order deconfinement transition appears
to end at a critical point at finite density. We investigate the strength of
the overlap and of the sign problems and discuss implications for the baryonic
density case.


title:
QCD finite T transition -- Comparison between Wilson and staggered
  results

abstract:
  A quantitative comparison between the finite temperature behaviour of the
staggered and Wilson fermion formulations are performed. The comparison is
based on a physical quantity that is expected to be quite sensitive to the
fermionic features of the action. For that purpose we use the height of the
peak for $d\chi_s/dT$, where $\chi_s$ is the quark number susceptibility.


title: Dualities in equivariant Kasparov theory

abstract:
  We study several duality isomorphisms between equivariant bivariant K-theory
groups, generalising Kasparov's first and second Poincare duality isomorphisms.
  We use the first duality to define an equivariant generalisation of Lefschetz
invariants of generalised self-maps. The second duality is related to the
description of bivariant Kasparov theory for commutative C*-algebras by
families of elliptic pseudodifferential operators. For many groupoids, both
dualities apply to a universal proper G-space. This is a basic requirement for
the dual Dirac method and allows us to describe the Baum-Connes assembly map
via localisation of categories.


title:
A Novel Precise Method for Correcting the Temperature in Stellar
  Atmosphere Models

abstract:
  A mayor problem that arises in the computation of stellar atmosphere models
is the self consistent determination of the temperature distribution via the
constraint of energy conservation. The energy balance includes the gains due to
the absorption of radiation and the losses due to emission. It is well known
that within each one of the two above integrals the part corresponding to
spectral ranges whose opacity X(nu) is huge can overcome by many orders of
magnitude the part that corresponds to the remaining frequencies. On the other
hand, at those frequencies where X(nu) is very large, the mean intensity J(nu)
of the radiation field shall be equal, up to many significant digits, to the
source function S(nu) and consequently to the Planck function B(nu,T). Then
their net share to the energy balance shall be null, albeit separately their
contributions to the gain and loss integrals are the most important
numerically. Thus the spectral range whose physical contribution to the overall
balance is null will dominate numerically both sides of the energy balance
equation, and consequently the errors on the determination of J(nu) and S(nu)
at these frequencies will falsify the balance.
  It is possible to circumvent the numerical problem brought about by the
foregoing circumstances by solving the radiative transfer equation for the
variable I(n,nu) - S(nu), instead of the customary intensity I(n,nu).
  We present here a novel iterative algorithm, based on iteration factors
already employed by us with success, which makes it possible a fast correction
of the temperature by computing directly the difference between the radiative
losses and gains at each step of the iterations.


title: Equivariant Lefschetz maps for simplicial complexes and smooth manifolds

abstract:
  Let X be a locally compact space with a continuous proper action of a locally
compact group G. Assuming that X satisfies a certain kind of duality in
equivariant bivariant Kasparov theory, we can enrich the classical construction
of Lefschetz numbers to equivariant K-homology classes. We compute the
Lefschetz invariants for self-maps of finite-dimensional simplicial complexes
and of self-maps of smooth manifolds. The resulting invariants are independent
of the extra structure used to compute them. Since smooth manifolds can be
triangulated, we get two formulas for the same Lefschetz invariant in these
cases. The resulting identity is closely related to the equivariant Lefschetz
Fixed Point Theorem of Luck and Rosenberg.


title: Selected topics on tau physics

abstract:
  The B Factories have generated a large amount of new results on the tau
lepton. The present status of some selected topics on tau physics is presented:
charged-current universality tests, bounds on lepton-flavour violation, the
determination of alpha_s from the inclusive tau hadronic width, and the
measurement of |V_{us}| through the Cabibbo-suppressed decays of the tau
lepton.


title:
Superfluid and Mott Insulating shells of bosons in harmonically confined
  optical lattices

abstract:
  Weakly interacting atomic or molecular bosons in quantum degenerate regime
and trapped in harmonically confined optical lattices, exhibit a wedding cake
structure consisting of insulating (Mott) shells. It is shown that superfluid
regions emerge between Mott shells as a result of fluctuations due to finite
hopping. It is found that the order parameter equation in the superfluid
regions is not of the Gross-Pitaeviskii type except near the insulator to
superfluid boundaries. The excitation spectra in the Mott and superfluid
regions are obtained, and it is shown that the superfluid shells posses low
energy sound modes with spatially dependent sound velocity described by a local
index of refraction directly related to the local superfluid density. Lastly,
the Berezinskii-Kosterlitz-Thouless transition and vortex-antivortex pairs are
discussed in thin (wide) superfluid shells (rings) limited by three (two)
dimensional Mott regions.


title: Four-vertex Model and Random Tilings

abstract:
  The exactly solvable four-vertex model on a square grid with the different
boundary conditions is considered. The application of the Algebraic Bethe
Ansatz method allows to calculate the partition function of the model. For the
fixed boundary conditions the connection of the scalar product of the state
vectors with the generating function of the column and row strict boxed plane
partitions is established. Tiling model on a periodic grid is discussed.


title: Metastable Supersymmetry Breaking in a Cooling Universe

abstract:
  I put metastable supersymmetry breaking in a cosmological context. I argue
that under reasonable assumptions, the cooling down early Universe favors
metastable SUSY-breaking vacua over the stable supersymmetric vacua. To
illustrate the general argument, I analyze the early-Universe history of the
Intriligator-Seiberg-Shih model.


title:
Model-independent measurement of the W boson helicity in top quark
  decays

abstract:
  We present the first model-independent measurement of the helicity of $W$
bosons produced in top quark decays, based on a 1 fb$^{-1}$ sample of candidate
$t\bar{t}$ events in the dilepton and lepton plus jets channels collected by
the D0 detector at the Fermilab Tevatron $p\bar{p}$ Collider. We reconstruct
the angle $\theta^*$ between the momenta of the down-type fermion and the top
quark in the $W$ boson rest frame for each top quark decay. A fit of the
resulting \costheta distribution finds that the fraction of longitudinal $W$
bosons $f_0 = 0.425 \pm 0.166 \hbox{(stat.)} \pm 0.102 \hbox{(syst.)}$ and the
fraction of right-handed $W$ bosons $f_+ = 0.119 \pm 0.090 \hbox{(stat.)} \pm
0.053 \hbox{(syst.)}$, which is consistent at the 30% C.L. with the standard
model.


title: The Metallicity Dependence of Wolf-Rayet Mass Loss

abstract:
  We produce models of early WN, WC, and WO stars as a function of metallicity
Z using an analytic CAK-type approach. At log(Z / Z_sun) >= -2 both WN and WC
stars have the approximate dependence Mdot \propto Z^{0.5}. For a WN wind the
mass-loss rate drops rapidly below log(Z / Z_sun) = -2, and no wind solution
can be found for log(Z / Z_sun) < -3. For WC and WO winds the mass-loss rate
plummets in the range -3 <= log(Z / Z_sun) <= -2 and tends to flatten due to
the self-enrichment of C and O to around 10^{-8} M_sun yr^{-1} for log(Z /
Z_sun) <= -4. No significant difference in Mdot was found for WC versus WO
stars at low metallicity.


title:
A universal tool for determining the time delay and the frequency shift
  of light: Synge's world function

abstract:
  In almost all of the studies devoted to the time delay and the frequency
shift of light, the calculations are based on the integration of the null
geodesic equations. However, the above-mentioned effects can be calculated
without integrating the geodesic equations if one is able to determine the
bifunction $\Omega(x_A, x_B)$ giving half the squared geodesic distance between
two points $x_A$ and $x_B$ (this bifunction may be called Synge's world
function). In this lecture, $\Omega(x_A, x_B)$ is determined up to the order
$1/c^3$ within the framework of the PPN formalism. The case of a stationary
gravitational field generated by an isolated, slowly rotating axisymmetric body
is studied in detail. The calculation of the time delay and the frequency shift
is carried out up to the order $1/c^4$. Explicit formulae are obtained for the
contributions of the mass, of the quadrupole moment and of the internal angular
momentum when the only post-Newtonian parameters different from zero are
$\beta$ and $\gamma$. It is shown that the frequency shift induced by the mass
quadrupole moment of the Earth at the order $1/c^3$ will amount to $10^{-16}$
in spatial experiments like the ESA's Atomic Clock Ensemble in Space mission.
Other contributions are briefly discussed.


title: The Point Processes of the GRW Theory of Wave Function Collapse

abstract:
  The Ghirardi-Rimini-Weber (GRW) theory is a physical theory that, when
combined with a suitable ontology, provides an explanation of quantum
mechanics. The so-called collapse of the wave function is problematic in
conventional quantum theory but not in the GRW theory, in which it is governed
by a stochastic law. A possible ontology is the flash ontology, according to
which matter consists of random points in space-time, called flashes. The joint
distribution of these points, a point process in space-time, is the topic of
this work. The mathematical results concern mainly the existence and uniqueness
of this distribution for several variants of the theory. Particular attention
is paid to the relativistic version of the GRW theory that I developed in 2004.


title: Moduli flow and non-supersymmetric AdS attractors

abstract:
  We investigate the attractor mechanism in gauged supergravity in the presence
of higher derivatives terms. In particular, we discuss the attractor behaviour
of static black hole horizons in anti-de Sitter spacetime by using the
effective potential approach as well as Sen's entropy function formalism. We
use the holographic techniques to interpret the moduli flow as an RG flow
towards the IR attractor horizon. We find that the holographic c-function obeys
the expected properties and point out some subtleties in understanding
attractors in AdS.


title:
Optical Observations of Gamma-Ray Bursts, the Discovery of Supernovae
  2005bv, 2005ee, and 2006ak, and Searches for Transients Using the "MASTER"
  Robotic Telescope

abstract:
  We present the results of observations obtained using the MASTER robotic
telescope in 2005 - 2006, including the earliest observations of the optical
emission of the gamma-ray bursts GRB 050824 and GRB 060926. Together with later
observations, these data yield the brightness-variation law t^{-0.55+-0.05} for
GRB 050824. An optical flare was detected in GRB 060926 - a brightness
enhancement that repeated the behavior observed in the X-ray variations. The
spectrum of GRB 060926 is found to be F_E ~ E^-\beta, where \beta = 1.0+-0.2.
Limits on the optical brightnesses of 26 gamma-ray bursts have been derived, 9
of these for the first time. Data for more than 90% of the accessible sky down
to $19^m$ were taken and reduced in real time during the survey. A database has
been composed based on these data. Limits have been placed on the rate of
optical flares that are not associated with detected gamma-ray bursts, and on
the opening angle for the beams of gamma-ray bursts. Three new supernovae have
been discovered: SN 2005bv (type Ia) - the first to be discovered on Russian
territory, SN 2005ee - one of the most powerful type II supernovae known, and
SN 2006ak (type Ia). We have obtained an image of SN 2006X during the growth
stage and a light curve that fully describes the brightness maximum and
exponential decay. A new method for searching for optical transients of
gamma-ray bursts detected using triangulation from various spacecraft is
proposed and tested.


title:
Detection of an oscillatory phenomenon in optical transient counterpart
  of GRB090522C from observations on Peak Terskol

abstract:
  22 Sep 2005 Swift-BAT triggered and located GRB050922C. The light curve shows
the intense broad peak with $T_{90}$ of $(5 \pm 1)$ s. The Nordic Optical
Telescope has obtained spectra of the afterglow with several absorption
features corresponding to a redshift of $z = 2.17 \pm 0.03$. Observation of
optical transient of GRB050922C was carried out in the R-band with the 60-cm
telescope equipped with a CCD on Peak Terskol (North Caucasus). The OT
magnitude was fading from R $\approx 16$ to $\approx 17.5$. Detection of an
oscillatory phenomenon in the R post-burst light curve is described in this
work. Analysis of the R data reveals coherent harmonic with a period of $0.0050
\pm 0.0003$ days (7.2 min) during observing run of about 0.05 days ($\sim 70$
min). Amplitude of oscillations is about 0.05 magnitude. The simplest model
suggests that GRB050922C may result from tidal disruption of a white dwarf star
by a black hole of about one thousand solar mass. The periodicity in the light
curve can be identified with relativistic precession of an accretion disc.


title: Quantum Cloning of Continuous Variable Entangled States

abstract:
  We consider the quantum cloning of continuous variable entangled states. This
is achieved by introducing two symmetric entanglement cloning machines (or
e-cloners): a local e-cloner and a global e-cloner; where we look at the
preservation of entanglement in the clones under the condition that the
fidelity of the clones is maximized. These cloning machines are implemented
using simple linear optical elements such as beam splitters and homodyne
detection along with squeeze gates. We show that the global e-cloner
out-performs the local e-cloner both in terms of the fidelity of the cloned
states as well as the strength of the entanglement of the clones. There is a
minimum strength of entanglement (3dB for the inseparability criterion and
5.7dB for the EPR paradox criterion) of the input state of the global e-cloner
that is required to preserve the entanglement in the clones.


title: On the uniqueness of smooth, stationary black holes in vacuum

abstract:
  We prove a conditional "no hair" theorem for smooth manifolds: if $E$ is the
domain of outer communication of a smooth, regular, stationary Einstein vacuum,
and if a technical condition relating the Ernst potential and Killing scalar is
satisfied on the bifurcate sphere, then $E$ is locally isometric to the domain
of outer communication of a Kerr space-time.


title:
Global Attraction to Solitary Waves in Models Based on the Klein-Gordon
  Equation

abstract:
  We review recent results on global attractors of U(1)-invariant dispersive
Hamiltonian systems. We study several models based on the Klein-Gordon equation
and sketch the proof that in these models, under certain generic assumptions,
the weak global attractor is represented by the set of all solitary waves. In
general, the attractors may also contain multifrequency solitary waves; we give
examples of systems which contain such solutions.


title:
Uniqueness results for ill posed characteristic problems in curved
  space-times

abstract:
  We prove two uniqueness theorems for solutions of linear and nonlinear wave
equations; the first theorem is in the Minkowski space while the second is in
the domain of outer communication of a Kerr black hole. Both theorems concern
ill posed Cauchy problems on smooth, bifurcate, characteristic hypersurfaces.
In the case of the Kerr space-time this hypersurface is the event horizon of
the black hole.


title:
The resource theory of quantum reference frames: manipulations and
  monotones

abstract:
  Every restriction on quantum operations defines a resource theory,
determining how quantum states that cannot be prepared under the restriction
may be manipulated and used to circumvent the restriction. A superselection
rule is a restriction that arises through the lack of a classical reference
frame and the states that circumvent it (the resource) are quantum reference
frames. We consider the resource theories that arise from three types of
superselection rule, associated respectively with lacking: (i) a phase
reference, (ii) a frame for chirality, and (iii) a frame for spatial
orientation. Focussing on pure unipartite quantum states (and in some cases
restricting our attention even further to subsets of these), we explore
single-copy and asymptotic manipulations. In particular, we identify the
necessary and sufficient conditions for a deterministic transformation between
two resource states to be possible and, when these conditions are not met, the
maximum probability with which the transformation can be achieved. We also
determine when a particular transformation can be achieved reversibly in the
limit of arbitrarily many copies and find the maximum rate of conversion. A
comparison of the three resource theories demonstrates that the extent to which
resources can be interconverted decreases as the strength of the restriction
increases. Along the way, we introduce several measures of frameness and prove
that these are monotonically nonincreasing under various classes of operations
that are permitted by the superselection rule.


title:
Entanglement of group-II-like atoms with fast measurement for quantum
  information processing

abstract:
  We construct a scheme for the preparation, pairwise entanglement via exchange
interaction, manipulation, and measurement of individual group-II-like neutral
atoms (Yb, Sr, etc.). Group-II-like atoms proffer important advantages over
alkali metals, including long-lived optical-transition qubits that enable fast
manipulation and measurement. Our scheme provides a promising approach for
producing weighted graph states, entangled resources for quantum communication,
and possible application to fundamental tests of Bell inequalities that close
both detection and locality loopholes.


title:
Softly broken $\mu\leftrightarrow\tau$ symmetry in the minimal see-saw
  model

abstract:
  Neutrino oscillations data indicates that neutrino mixings are consistent
with an apparent $\nu_\mu - \nu_\tau$ exchange symmetry in neutrino mass
matrix. We observe that in the mininimally extended standard model with the
see-saw mechanism, one can impose $\mu\leftrightarrow\tau$ symmetry at the tree
level on all Lagrangian terms, but for the mass difference among $\mu$ and
$\tau$ leptons. In the absence of any new extra physics, this mass difference
becomes the only source for the breaking of such a symmetry, which induces, via
radiative corrections, small but predictable values for $\theta_{13}$, and for
the deviation of $\theta_{ATM}$ from maximallity. In the CP conserving case,
the predictions only depend on neutrino mass hierarchy and may provide a unique
way to test for new physics with neutrino experiments.


title: The von Neumann-Wigner theorem in quantum dot molecules

abstract:
  We show that electrons in coupled quantum dots characterized by high aspect
ratios undergo abrupt density rotations when the dots are biased into an
asymmetric confinement configuration. Density rotations occur with electron
transfer to a single dot, and give rise to sharp variations of the exchange
coupling between electrons as a function of inter-dot detuning. Our analysis
based on exact diagonalization technique indicates that this unusual behavior
is in agreement with the von Neumann-Wigner theorem that dictates the
variations of the energy spectrum from the symmetries of the molecular states
during the detuning process. It is also shown that the overall effect is
quenched by the presence of magnetic fields, which by adding angular momentum
to the electron motion affects the spatial symmetry of the molecular states.


title:
Tunable quantum interference: How to make morning, noon, and afternoon
  states

abstract:
  We show that the N-photon states produced by interference between laser light
and downconverted light at the input of a two path interferometer can be
characterized by a single tuning parameter that describes a transition from
phase squeezing to nearly maximal path entanglement and back. The quantum
states are visualized on a sphere using the analogy between N-photon
interference and the spin-N/2 algebra.


title: Declarative Diagnosis of Floundering

abstract:
  Many logic programming languages have delay primitives which allow
coroutining. This introduces a class of bug symptoms -- computations can
flounder when they are intended to succeed or finitely fail. For concurrent
logic programs this is normally called deadlock. Similarly, constraint logic
programs can fail to invoke certain constraint solvers because variables are
insufficiently instantiated or constrained. Diagnosing such faults has received
relatively little attention to date. Since delay primitives affect the
procedural but not the declarative view of programs, it may be expected that
debugging would have to consider the often complex details of interleaved
execution. However, recent work on semantics has suggested an alternative
approach. In this paper we show how the declarative debugging paradigm can be
used to diagnose unexpected floundering, insulating the user from the
complexities of the execution.
  Keywords: logic programming, coroutining, delay, debugging, floundering,
deadlock, constraints


title: SO(4) symmetry in the relativistic hydrogen atom

abstract:
  We show that the relativistic hydrogen atom possesses an SO(4) symmetry by
introducing a kind of pseudo-spin vector operator. The same SO(4) symmetry is
still preserved in the relativistic quantum system in presence of an U(1)
monopolar vector potential as well as a nonabelian vector potential. Lamb shift
and SO(4) symmetry breaking are also discussed.


title:
Characterization of nanometer-sized, mechanically exfoliated graphene on
  the H-passivated Si(100) surface using scanning tunnelling microscopy

abstract:
  We have developed a method for depositing graphene monolayers and bilayers
with minimum lateral dimensions of 2-10 nm by the mechanical exfoliation of
graphite onto the Si(100)-2x1:H surface. Room temperature, ultra-high vacuum
(UHV) tunnelling spectroscopy measurements of nanometer-sized single-layer
graphene reveal a size dependent energy gap ranging from 0.1-1 eV. Furthermore,
the number of graphene layers can be directly determined from scanning
tunnelling microscopy (STM) topographic contours. This atomistic study provides
an experimental basis for probing the electronic structure of nanometer-sized
graphene which can assist the development of graphene-based nanoelectronics.


title:
Direct Evidence from Spitzer for a low-luminosity AGN at the center of
  the Elliptical Galaxy NGC 315

abstract:
  We present the {\it Spitzer} Space Telescope InfraRed Array Camera (IRAC) and
Multiband Imaging Photometer (MIPS) observations of the elliptical galaxy NGC
315. After removal of the host galaxy's stellar emission, we detected for the
first time an infrared-red nucleus in NGC 315. We measured the spectral energy
distribution (SED) for this active nucleus with wavelength range covering from
radio to X-ray, and obtained the bolometric luminosity of $\rm L_{bol} \approx
1.9 \times 10^{43} ergs s^{-1}$, corresponding to an extremely low Eddington
ratio (L/L$_{\rm Edd}$) of 4.97 $\times$ 10$^{-4}$. Our results confirm that
the physical nature of the nucleus of NGC 315 is a low-luminosity AGN,
consistent with the recent optical and {\it Chandra} X-ray observations.


title: TriMinimal Parametrization of the Neutrino Mixing Matrix

abstract:
  Current experimental data on neutrino mixing are very well described by
TriBiMaximal mixing. Accordingly, any phenomenological parametrization of the
MNSP matrix must build upon TriBiMaximal mixing. We propose one particularly
natural parametrization, which we call "TriMinimal". The three small deviations
of the PDG angles from their TriBiMaximal values, and the PDG phase,
parametrize the TriMinimal mixing matrix. As an important example of the
utility of this new parametrization, we present the simple resulting
expressions for the flavor-mixing probabilities of atmospheric and
astrophysical neutrinos. As no foreseeable experiment will be sensitive to more
than second order in the small parameters, we expand these flavor probabilities
to second order.


title: Study of TeV Neutrinos with Upward Showering Muons in Super-Kamiokande

abstract:
  A subset of neutrino-induced upward through-going muons in the
Super-Kamiokande detector consists of high energy muons which lose energy
through radiative processes such as bremsstrahlung, e^{+} e^{-} pair production
and photonuclear interactions. These ``upward showering muons'' comprise an
event sample whose mean parent neutrino energy is approximately 1 TeV. We show
that the zenith angle distribution of upward showering muons is consistent with
negligible distortion due to neutrino oscillations, as expected of such a
high-energy neutrino sample. We present astronomical searches using these high
energy events, such as those from WIMP annihilations in the Sun, Earth and
Galactic Center, some suspected point sources, as well as searches for diffuse
flux from the interstellar medium.


title: S-duality in N=2 supersymmetric gauge theories

abstract:
  A solution to the infinite coupling problem for N=2 conformal supersymmetric
gauge theories in four dimensions is presented. The infinitely-coupled theories
are argued to be interacting superconformal field theories (SCFTs) with weakly
gauged flavor groups. Consistency checks of this proposal are found by
examining some low-rank examples. As part of these checks, we show how to
compute new exact quantities in these SCFTs: the central charges of their
flavor current algebras. Also, the isolated rank 1 E_6 and E_7 SCFTs are found
as limits of Lagrangian field theories.


title:
Complex projective scheme approach to the geometrical structures of
  multipartite quantum systems

abstract:
  In this paper, I will discuss the geometrical structures of multipartite
quantum systems based on complex projective schemes. In particular, I will
explicitly construct multi-qubit states in terms of these schemes and also
discuss separability and entanglement of bipartite and multipartite quantum
states. These results give some geometrical insight to the fascinating quantum
mechanical phenomena of entanglement which is fundamentally important and has
many applications in the field of quantum computing.


title: Lorentz Invariance Violation and Symmetry in Randers--Finsler Spaces

abstract:
  Lorentz Invariance violation is a common feature of new physics beyond the
standard model. We show that the symmetry of Randers spaces deduces a modified
dispersion relation with characteristics of Lorentz Invariance violation. The
counterparts of the Lorentz transformation in the Einstein's Special Relativity
are presented explicitly. The coordinate transformations are unitary and form a
group. Generators and algebra satisfied by them are different from usual
Lorentz ones. The Randersian line element as well as speed of light is
invariant under the transformations. In particular, there is another invariant
speed which may be related with Planck scale and the mass of moving particle.
Thus, the Randers spaces is a suitable framework to discuss the Lorentz
Invariance violation.


title: Cohen-Macaulay modules and holonomic modules over filtered rings

abstract:
  We study Gorenstein dimension and grade of a module $M$ over a filtered ring
whose assosiated graded ring is a commutative Noetherian ring. An equality or
an inequality between these invariants of a filtered module and its associated
graded module is the most valuable property for an investigation of filtered
rings. We prove an inequality G-dim$M\leq{G-dim gr}M$ and an equality ${\rm
grade}M={\rm grade gr}M$, whenever Gorenstein dimension of ${\rm gr}M$ is
finite (Theorems 2.3 and 2.8). We would say that the use of G-dimension adds a
new viewpoint for studying filtered rings and modules. We apply these results
to a filtered ring with a Cohen-Macaulay or Gorenstein associated graded ring
and study a Cohen-Macaulay, perfect or holonomic module.


title:
Development of simulation package for atomic processes of
  ultra-large-scale system based on electronic structure theory

abstract:
  An early-stage version of simulation package is developed for electronic
structure calculation and dynamics of atom process in large-scale systems,
particularly, nm-scale or 10nm-scale systems. We adopted the Extensible Markup
Language (XML)-style in the input and the output of our simulation code, and
developed some modeling and analysis tools for dynamical simulations of atomic
processes. GaAs bulk system was calculated to demonstrate that the present code
can handle systems with more than one atom specie.


title: Point-contact search for antiferromagnetic giant magnetoresistance

abstract:
  We report the first measurements of effects of large current densities on
current-perpendicular-to-plane magnetoresistance (MR) of magnetic multilayers
containing two antiferromagnetic layers separated by a non-magnetic layer.
These measurements were intended to search for a recently predicted
antiferromagnetic giant magnetoresistance (AGMR) similar to GMR seen in
multilayers containing two ferromagnetic layers separated by a non-magnetic
layer. We report on MR measurements for current injected from point contacts
into sandwiches containing different combinations of layers of F = CoFe and AFM
= FeMn. In addition to: AFM/N/AFM, F/AFM/N/AFM, and F/AFM/N/AFM/F structures,
initial results led us to examine also AFM/F/N/AFM, F/AFM, and single F- and
AFM-layer structures. At low currents, no MR was observed in any samples, and
no MR was observed at any current densities in samples containing only AFMs.
Together, these results indicate that no AGMR is present in these samples. In
samples containing F-layers, high current densities sometimes produced a small
positive MR - largest resistance at high fields. For a given contact
resistance, this MR was usually larger for thicker F-layers, and for a given
current, it was usually larger for larger contact resistances (smaller
contacts). We tentatively attribute this positive MR to suppression at high
currents of spin accumulation induced around and within the F-layers.


title: Picolitre viscometry using optically rotated particles

abstract:
  Important aspects in the field of microrheology are the studies of the
viscosity of fluids within structures with micron dimensions and fluid samples
where only microlitre volumes are available. We have quantitatively
investigated the performance and accuracy of a microviscometer based on
rotating optical tweezers, that requires as little as one microlitre of sample.
We have characterised our microviscometer, including effects due to heating,
and demonstrated its ability to perform measurements over a large dynamic range
of viscosities (at least two orders of magnitude). We have also inserted a
probe particle through the membrane of a cell and measured the viscosity of the
intramembranous contents. Viscosity measurements of tears have also been made
with our microviscometer, which demonstrate its potential use to study
un-stimulated eye fluid.

categories: physics.optics physics.bio-ph physics.flu-dyn physics.ins-det


title: The velocity increase of mass and the classical physics

abstract:
  In the past century it was believed that both the main theories (quantum
mechanics and special relativity) predicted the existence of physical processes
that could not be explained in the framework of classical physics. However, it
has been shown recently that the solutions of Schroedinger equation have
described the physical situation practically in full agreement with classical
equations. The given equation represents the combination of classical equations
with the statistical distribution of corresponding parameters and the
properties of microscopic objects may be interpreted on the ontological basis
as it corresponds to our sensual knowledge.
  It will be shown now that also the main experimentally relevant relativistic
phenomenon (i.e., the mass increase with velocity) may be interpreted in the
framework of classical physics. A different prediction for this increase will
be then derived, which gives the possibility to decide on experimental basis
which alternative is more preferable (relativistic or classical).


title: Anisotropic fluid with time dependent viscosity coefficients

abstract:
  A spacetime endowed with an anisotropic fluid is proposed for the interior of
a Schwarzschild black hole. The geometry has an instantaneous Minkowski form
and is a solution of Einstein's equations with a stress tensor on the r.h.s.
obeying all the energy conditions.
  The interior fluid is compressible, with time dependent shear and bulk
viscosity coefficients. The energy density $\rho$ and the ''radial'' pressure
$p$ observe the equation of state $p + \rho = 0$ (as for dark energy), with no
pressures on $\theta-$ and $\phi-$ directions. However, the angular components
of the viscous part of the stress tensor are nonvanishing and equals the energy
density of the fluid.


title: On 5D AdS SUSY and Harmonic Superspace

abstract:
  In our recent paper arXiv:0704.1185 [hep-th], we presented the differential
geometry of five-dimensional N=1 anti-de Sitter superspace
AdS^{5|8}=SU(2,2|1)/SO(4,1) x U(1) and developed the harmonic and the
projective superspace settings to formulate off-shell supersymmetric theories
in AdS^{5|8}. Here we give a brief review of the geometry and the harmonic
superspace construction, and also elaborate on vector supermultiplets.


title:
Subnatural linewidth using electromagnetically induced transparency in
  Doppler-broadened vapor

abstract:
  We obtain subnatural linewidth (i.e. $<\Gamma$) for probe absorption in
room-temperature Rb vapor using electromagnetically induced transparency (EIT)
in a $\Lambda$ system. For stationary atoms, the EIT dip for a resonant control
laser is as wide as the control Rabi frequency $\Omega_c$. But in thermal
vapor, the moving atoms fill the transparency band so that the final EIT dip
remains subnatural even when $\Omega_c > \Gamma$. We observe linewidths as
small as $\Gamma/7$ in the $D_2$ line of Rb.


title: Kinematic Density Waves in Accretion Disks

abstract:
  When thin accretion disks around black holes are perturbed, the main
restoring force is gravity. If gas pressure, magnetic stresses, and radiation
pressure are neglected, the disk remains thin as long as orbits do not
intersect. Intersections would result in pressure forces which limit the growth
of perturbations. We find that a discrete set of perturbations is possible for
which orbits remain non-intersecting for arbitrarily long times. These modes
define a discrete set of frequencies. We classify all long-lived perturbations
for arbitrary potentials and show how their mode frequencies are related to
pattern speeds computed from the azimuthal and epicyclic frequencies. We show
that modes are concentrated near radii where the pattern speed has vanishing
radial derivative. We explore these modes around Kerr black holes as a possible
explanation for the high-frequency quasi-periodic oscillations of black hole
binaries such as GRO J1655-40. The long-lived modes are shown to coincide with
diskoseismic waves in the limit of small sound speed. While the waves have long
lifetime, they have the wrong frequencies to explain the pairs of
high-frequency quasi-periodic oscillations observed in black hole binaries.


title: Photon statistics from a resonantly driven quantum dot

abstract:
  Photon correlations in the emission of a resonantly driven quantum dot are
investigated, accounting for the influence of the solid-state phonon
environment. An analytical expression is derived for the second-order
fluorescence intensity correlation function, from which regimes of correlated
and uncorrelated photon emission are predicted as the driving field is varied.
Experiments to investigate this effect would provide valuable insight into
quantum dot carrier-phonon dynamics and are feasible with current technology.


title:
High-precision measurement of hyperfine structure in the $D$ lines of
  alkali atoms

abstract:
  We have measured hyperfine structure in the first-excited $P$ state ($D$
lines) of all the naturally-occurring alkali atoms. We use high-resolution
laser spectroscopy to resolve hyperfine transitions, and measure intervals by
locking the frequency shift produced by an acousto-optic modulator to the
difference between two transitions. In most cases, the hyperfine coupling
constants derived from our measurements improve previous values significantly.


title: Schreier spectrum of the Hanoi Towers group on three pegs

abstract:
  Finite dimensional representations of the Hanoi Towers group are used to
calculate the spectra of the finite graphs associated to the Hanoi Towers Game
on three pegs (the group serves as a renorm group for the game). These graphs
are Schreier graphs of the action of the Hanoi Towers group on the levels of
the rooted ternary tree. The spectrum of the limiting graph (Schreier graph of
the action on the boundary of the tree) is also provided.


title: Conditions for the Formation of First-Star Binaries

abstract:
  The fragmentation process of primordial-gas cores during prestellar collapse
is studied using three-dimensional nested-grid hydrodynamics. Starting from the
initial central number density of n \sim10^3 cm^-3, we follow the evolution of
rotating spherical cores up to the stellar density n \simeq 10^{22} cm^-3. An
initial condition of the cores is specified by three parameters: the ratios of
the rotation and thermal energies to the gravitational energy (\beta_0, and
\alpha_0, respectively), and the amplitude of the bar-mode density perturbation
(A_\phi). Cores with rotation \beta_0 > 10^{-6} are found to fragment during
the collapse. The fragmentation condition hardly depends on either the initial
thermal energy \alpha_0 or amplitude of bar-mode perturbation A_\phi. Since the
critical rotation parameter for fragmentation is lower than that expected in
the first star formation, binaries or multiples are also common for the first
stars.


title: Mirkovic-Vilonen cycles and polytopes for a Symmetric pair

abstract:
  Let $G$ be a connected, simply-connected, and almost simple algebraic group,
and let $\sigma$ be a Dynkin automorphism on $G$. In this paper, we get a
bijection between the set of $\st$-invariant MV cycles (polytopes) for $G$ and
the set of MV cycles (polytopes) for $G^\st$, which is the fixed point subgroup
of $G$; moreover, this bijection can be restricted to the set of MV cycles
(polytopes) in irreducible representations. As an application, we obtain a new
proof of the twining character formula.


title:
A modification of the Anderson-Mirkovic conjecture for Mirkovic-Vilonen
  polytopes in types B and C

abstract:
  We give an explicit description of the (lowering) Kashiwara operators on
Mirkovi\'c-Vilonen polytopes in types $B$ and $C$, which provides a simple
method for generating Mirkovi\'c-Vilonen polytopes inductively. This
description can be thought of as a modification of the original
Anderson-Mirkovi\'c conjecture, which Kamnitzer proved in the case of type $A$,
and presented a counterexample in the case of type $C_{3}$.


title: Note on the question of Sikora

abstract:
  A natural topology on the set of left orderings on free abelian groups and
free groups $F_n$, $n>1$ has studied in [1]. It has been proven already that in
the abelian case the resulted topological space is a Cantor set. There was a
conjecture: this is also true for the free group $F_n$ with $n>1$ generators.
We point out the article dealing with equivalent questions. The answer is
"yes".


title: Third moment of the remainder term for Heisenberg manifolds

abstract:
  Let R(t) be the remainder term in Weyl's law for a 3-dimensional Riemannian
Heisenberg manifold with a certain arithmetic metric. We prove a third moment
result stating that \int_1^T R(t)^3 dt =d_3
T^(13/4)+O_\delta(T^(45/14+\delta)), where d_3 is a specific positive constant
which can be evaluated explicitly. This proves the asymmetric behavior of R(t)
about the t-axis. This result is consistent with the conjecture of Petridis and
Toth stating that R(t)=O_\delta(t^(3/4+\delta)). Similar results hold for
(2n+1)-dimensional Heisenberg manifolds with arithmetic metrics.


title:
Staying positive: going beyond Lindblad with perturbative master
  equations

abstract:
  The perturbative master equation (Bloch-Redfield) is extensively used to
study dissipative quantum mechanics - particularly for qubits - despite the 25
year old criticism that it violates positivity (generating negative
probabilities). We take an arbitrary system coupled to an environment
containing many degrees-of-freedom, and cast its perturbative master equation
(derived from a perturbative treatment of Nakajima-Zwanzig or Schoeller-Schon
equations) in the form of a Lindblad master equation. We find that the
equation's parameters are time-dependent. This time-dependence is rarely
accounted for, and invalidates Lindblad's dynamical semigroup analysis. We
analyze one such Bloch-Redfield master equation (for a two-level system coupled
to an environment with a short but non-vanishing memory time), which apparently
violates positivity. We show analytically that, once the time-dependence of the
parameters is accounted for, positivity is preserved.


title: Bosons after Symmetry Breaking in Quantum Field Theory

abstract:
  We present a unified description of the spontaneous symmetry breaking and its
associated bosons in fermion field theory. There is no Goldstone boson in the
fermion field theory models of Nambu-Jona-Lasinio, Thirring and QCD$_2$ after
the chiral symmetry is spontaneously broken in the new vacuum. The defect of
the Goldstone theorem is clarified, and the "massless boson" predicted by the
theorem is virtual and corresponds to just a $free$ massless fermion and
antifermion pair. Further, we discuss the exact spectrum of the Thirring model
by the Bethe ansatz solutions, and the analytical expressions of all the
physical observables enable us to understand the essence of the spontaneous
symmetry breaking in depth. Also, we examine the boson spectrum in QCD$_2$, and
show that bosons always have a finite mass for $SU(N_c)$ colors. The problem of
the light cone prescription in QCD$_2$ is discussed, and it is shown that the
trivial light cone vacuum is responsible for the wrong prediction of the boson
mass.


title: Functional Integrals in Affine Quantum Gravity

abstract:
  A sketch of a recent approach to quantum gravity is presented which involves
several unconventional aspects. The basic ingredients include: (1) Affine
kinematical variables; (2) Affine coherent states; (3) Projection operator
approach for quantum constraints; (4) Continuous-time regularized functional
integral representation without/with constraints; and (5) Hard core picture of
nonrenormalizability. Emphasis is given to the functional integral expressions.


title: Dark Energy and Dark Gravity

abstract:
  Observations provide increasingly strong evidence that the universe is
accelerating. This revolutionary advance in cosmological observations confronts
theoretical cosmology with a tremendous challenge, which it has so far failed
to meet. Explanations of cosmic acceleration within the framework of general
relativity are plagued by difficulties. General relativistic models are nearly
all based on a dark energy field with fine-tuned, unnatural properties. There
is a great variety of models, but all share one feature in common -- an
inability to account for the gravitational properties of the vacuum energy.
Speculative ideas from string theory may hold some promise, but it is fair to
say that no convincing model has yet been proposed. An alternative to dark
energy is that gravity itself may behave differently from general relativity on
the largest scales, in such a way as to produce acceleration. The alternative
approach of modified gravity (or dark gravity) provides a new angle on the
problem, but also faces serious difficulties, including in all known cases
severe fine-tuning and the problem of explaining why the vacuum energy does not
gravitate. The lack of an adequate theoretical framework for the late-time
acceleration of the universe represents a deep crisis for theory -- but also an
exciting challenge for theorists. It seems likely that an entirely new paradigm
is required to resolve this crisis.


title:
Separability of Dirac equation in higher dimensional Kerr-NUT-de Sitter
  spacetime

abstract:
  It is shown that the Dirac equations in general higher dimensional
Kerr-NUT-de Sitter spacetimes are separated into ordinary differential
equations.


title: Generalized Cosmic Chaplygin Gas Model with or without Interaction

abstract:
  Recently developed Generalized Cosmic Chaplygin gas (GCCG) is studied as an
unified model of dark matter and dark energy. To explain the recent
accelerating phase, the Universe is assumed to have a mixture of radiation and
GCCG. The mixture is considered for without or with interaction. Solutions are
obtained for various choices of the parameters and trajectories in the plane of
the statefinder parameters and presented graphically. For particular choice of
interaction parameter, we have shown the role of statefinder parameters in
various cases for the evolution of the Universe.


title:
Degree and component size distributions in generalized uniform recursive
  tree

abstract:
  We propose a generalized model for uniform recursive tree (URT) by
introducing an imperfect growth process, which may generate disconnected
components (clusters). The model undergoes an interesting phase transition from
a singly connected network to a graph consisting of fully isolated nodes. We
investigate the distributions of degree and component sizes by both theoretical
predictions and numerical simulations. For the nontrivial cases, we show that
the network has an exponential degree distribution while its component size
distribution follows a power law, both of which are related to the imperfect
growth process. We also predict the growth dynamics of the individual
components. All analytical solutions are successfully contrasted with computer
simulations.


title:
Number of sets with small sumset and the clique number of random Cayley
  graphs

abstract:
  Let $G$ be a finite abelian group of order $n$. For any subset $B$ of $G$
with $B=-B$, the Cayley graph $G_B$ is a graph on vertex set $G$ in which $ij$
is an edge if and only if $i-j\in B.$ It was shown by Ben Green that when $G$
is a vector space over a finite field $Z/pZ$, then there is a Cayley graph
containing neither a complete subgraph nor an independent set of size more than
$clog nloglog n,$ where $c$ is an absolute constant. In this article we observe
that a modification of his arguments shows that for an arbitrary finite abelian
group of order $n$, there is a Cayley graph containing neither a complete
subgraph nor an independent set of size more than $c(omega^3(n)log omega(n)
+log nloglog n)$, where $c$ is an absolute constant and $omega(n)$ denotes the
number of distinct prime divisors of $n$.


title: Meta-Stable Brane Configurations with Multiple NS5-Branes

abstract:
  Starting from an N=1 supersymmetric electric gauge theory with the multiple
product gauge group and the bifundamentals, we apply Seiberg dual to each gauge
group, obtain the N=1 supersymmetric dual magnetic gauge theories with dual
matters including the gauge singlets. Then we describe the intersecting brane
configurations, where there are NS-branes and D4-branes(and anti D4-branes), of
type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua
of this gauge theory.
  We also discuss the case where the orientifold 4-planes are added into the
above brane configuration. Next, by adding an orientifold 6-plane, we apply to
an N=1 supersymmetric electric gauge theory with the multiple product gauge
group(where a single symplectic or orthogonal gauge group is present) and the
bifundamentals. Finally, we describe the other cases where the orientifold
6-plane intersects with NS-brane.


title: Elliptic curves related to cyclic cubic extensions

abstract:
  The aim of this paper is to study certain family of elliptic curves
$\{\mathscr{X}_H\}_H$ defined over a number field $F$ arising from hyperplane
sections of some cubic surface $\mathscr{X}/F$ associated to a cyclic cubic
extension $K/F$. We show that each $\mathscr{X}_H$ admits a 3-isogeny $\phi$
over $F$ and the dual Selmer group $S^{(\hat{\phi})}(\hat{\mathscr{X}_H}/F)$ is
bounded by a kind of unit/class groups attached to $K/F$. This is proven via
certain rational function on the elliptic curve $\mathscr{X}_H$ with nice
property. We also prove that the Shafarevich-Tate group $\text{\cyr X}
(\hat{\mathscr{X}_H}/\rat)[\hat{\phi}]$ coincides with a class group of $K$ as
a special case.


title:
Exchange in multi-defect semiconductor clusters: assessment of
  `control-qubit' architectures

abstract:
  We present a variational method to calculate the exchange interactions among
donor clusters in a semiconductor. Such clusters are candidates for a so-called
control-qubit architecture for quantum information, where the effective
exchange coupling between two atoms is controlled by the electronic state of a
third. We use a combination of the effective-mass approximation and the quantum
defect method; our variational ansatz is particularly suited to cases where an
excited state of one of the donors (control) is partially delocalised over
several different centres, forming an analogue of an extended molecular
orbital. Our method allows calculations of the "on/off" ratios of exchange
interactions in such cases. We compare exchange interactions when the control
is in the "on" and "off" states, and find that both the magnitude and sign of
the exchange interactions may be changed. To rationalize the sign-change, we
carry out a simple Green's function perturbation-theory calculation. This
simple model qualitatively explains the sign change and illustrates its origins
both in ring-exchange processes and in the delocalization of the control
electron. We also compute probability distributions for the coupling strengths
over the ensemble of clusters, and show that excitation of the control causes
narrowing of the distributions along with shifts to larger magnitudes and from
anti-ferromagnetic to ferromagnetic coupling.


title: Twisted p-adic (h,q)-L-functions

abstract:
  By using q-Volkenborn integral on Z_{p}, we (simsek, simsekCanada)
constructed new generating functions of the (h,q)-Bernoulli polynomials and
numbers. By applying the Mellin transformation to the generating functions, we
constructed integral representation of the twisted (h,q)-Hurwitz function and
twisted (h,q)-two-variable L-function. By using these functions, we construct
twisted new (h,q)-partial zeta function which interpolates the twisted
(h,q)-Bernoulli polynomials and generalized twisted (h,q)-Bernoulli numbers at
negative integers. We give relation between twisted (h,q)-partial zeta
functions and twisted (h,q)-two-variable L-function. We find the value of this
function at s=0. We also find residue of this function at s=1. We construct
p-adic twisted (h,q)-L-function, which interpolates the twisted (h,q)-Bernoulli
polynomials.


title: Convex and linear models of NP-problems

abstract:
  Reducing the NP-problems to the convex/linear analysis on the Birkhoff
polytope.