title: Phase-space structures I: A comparison of 6D density estimators

abstract:
  This paper reviews and analyses methods used to identify neighbours in 6D
space and estimate the corresponding phase-space density. It compares SPH
methods to 6D Delaunay tessellation on statical and dynamical realisation of
single halo profiles, paying attention to the unknown scaling, S_G, used to
relate the spatial dimensions to the velocity dimensions. The methods with
local adaptive metric provide the best phase-space estimators. They make use of
a Shannon entropy criterion combined with a binary tree partitioning and with
SPH interpolation using 10-40 neighbours. Local scaling implemented by such
methods, which enforces local isotropy of the distribution function, can vary
by about one order of magnitude in different regions within the system. It
presents a bimodal distribution, in which one component is dominated by the
main part of the halo and the other one is dominated by the substructures.
While potentially better than SPH techniques, since it yields an optimal
estimate of the local softening volume (and the local number of neighbours
required to perform the interpolation), the Delaunay tessellation in fact
poorly estimates the phase-space distribution function. Indeed, it requires,
the choice of a global scaling S_G. We propose two methods to estimate S_G that
yield a good global compromise. However, the Delaunay interpolation still
remains quite sensitive to local anisotropies in the distribution. We also
compare 6D phase-space density estimation with the proxy, Q=rho/sigma^3, where
rho is the local density and 3 sigma^2 is the local 3D velocity dispersion. We
show that Q only corresponds to a rough approximation of the true phase-space
density, and is not able to capture all the details of the distribution in
phase-space, ignoring, in particular, filamentation and tidal streams.


title:
With commuting Killing vectors, the lapse and shift of one Killing
  vector are constants along the other

abstract:
  Given an d-dimensional manifold with two commuting Killing vectors, together
with an d - 1 dimensional submanifold in which one of the Killing vectors lies,
then the lapse and shift of the second Killing vector, relative to this slice,
remain constant along the orbits of the `surface' Killing vector.
Alternatively, the six dot products that can be formed from the three vectors,
the two Killing vectors and the normal to the submanifold, are all constants
along the `surface' Killing vector.


title:
Stellar wobble caused by a binary system: Can it really be mistaken as
  an extra-solar planet?

abstract:
  The traditional method for detecting extra-solar planets relies on measuring
a small stellar wobble which is assumed to be caused by a planet orbiting the
star. Recently, it was suggested that a similar stellar wobble could be caused
by a close binary system (Schneider and Cabrera, 2006). Here we show that,
although the effect of a close binary system can at first sight be mistaken as
a planetary companion to the star, more careful analysis of the observational
data should allow us to distinguish between the two effects.


title: An overview of abelian varieties in homotopy theory

abstract:
  This is an expository article on the theory of formal group laws in homotopy
theory, with the goal of leading to the connection with higher-dimensional
abelian varieties and automorphic forms. These are roughly based on a talk at
the conference "New Topological Contexts for Galois Theory and Algebraic
Geometry."


title: Drawing disconnected graphs on the Klein bottle

abstract:
  We prove that two disjoint graphs must always be drawn separately on the
Klein bottle, in order to minimize the crossing number of the whole drawing.


title:
Continuous Paranematic-to-Nematic Ordering Transitions of Liquid
  Crystals in Tubular Silica Nanochannels

abstract:
  The optical birefringence of rod-like nematogens (7CB, 8CB), imbibed in
parallel silica channels with 10 nm diameter and 300 micrometer length, is
measured and compared to the thermotropic bulk behavior. The orientational
order of the confined liquid crystals, quantified by the uniaxial nematic
ordering parameter, evolves continuously between paranematic and nematic
states, in contrast to the discontinuous isotropic-to-nematic bulk phase
transitions. A Landau-de Gennes model reveals that the strength of the
orientational ordering fields, imposed by the silica walls, is beyond a
critical threshold, that separates discontinuous from continuous
paranematic-to-nematic behavior. Quenched disorder effects, attributable to
wall irregularities, leave the transition temperatures affected only
marginally, despite the strong ordering fields in the channels.

categories: cond-mat.soft cond-mat.mtrl-sci cond-mat.stat-mech physics.chem-ph physics.optics


title:
Colloidal charge reversal: Dependence on the ionic size and the
  electrolyte concentration

abstract:
  Extensive Monte Carlo simulations and scaling arguments are used to study the
colloidal charge reversal. The critical colloidal surface charge density
$\sigma_c$ at which the reversal first appears is found to depend strongly on
the ionic size. We find that $\sigma_c$ has an inflection point as a function
of the electrolyte concentration. The width of the plateau region in the
vicinity of the inflection point depends on the temperature and the ionic
radius $a$. In agreement with the theoretical predictions it is found that the
critical colloidal charge above which the electrophoretic mobility becomes
reversed diverges as $Z_c \sim 1/a^2$ in the limit $a \to 0$.


title: Lightest Neutralino Mass in the MNSSM

abstract:
  We argue that the allowed range of the mass of the lightest neutralino in the
MNSSM is limited. We establish the theoretical upper bound on the lightest
neutralino mass and obtain an approximate solution for this mass.


title: Persistence in Advection of Passive Scalar

abstract:
  We consider the persistence phenomenon in advectecd passive scalar equation
in 1-dimension. The velocity field is random with the
$<v(k,\omega)v(-k,-\omega) > \sim |k|^{-(2+\alpha)}$. In presence of the
non-linearity the complete Green's function becomes
$G^{-1}=-i\omega+Dk^2+\Sigma$. We determine $\Sigma$ self-consistently from the
correlation function which gives $\Sigma \sim k^{\beta}$, with
$\beta=(1-\alpha)/2$. The effect of the non-linear term in the equation in the
$\mathcal{O}(\epsilon^2)$ is to replace the diffusion term due to molecular
viscosity by an effective term of the form $\Sigma_0 k^{\beta}$. The stationary
correlator for this system is $[\mathrm{Sech}(T/2)]^{1/\beta}$. Using the
self-consistent theory we have determined the relation between $\beta$ and
$\alpha$. Finally, IIA is used to determine the persistent exponent.


title:
Detection of blueshifted emission and absorption and a relativistic Iron
  line in the X-ray spectrum of ESO 323-G077

abstract:
  We report on the X-ray observation of the Seyfert 1 ESO323-G077 performed
with XMM-Newton. The spectra show a complex spectrum with conspicuous
absorption and emission features. The continuum emission can be modelled with a
power law with an index of 1.99+/-0.02 in the whole XMM-Newton energy band,
marginally consistent with typical values of Type-I objects. An absorption
component with an uncommonly high equivalent Hydrogen column,
n_H=5.82(+0.12/-0.11)x10^22 cm-2, is affecting the soft part of the spectrum.
Additionally, two warm absorption components are also present. The lower
ionised one has an ionisation parameter of Log(U)=2.14(+0.06/-0.07) and an
outflowing velocity of v=3200(+600/-200) km/s. Two absorption lines located at
~6.7 and ~7.0 keV can be modelled with the highly ionised absorber. The
ionisation parameter and outflowing velocity of the gas measured are
Log(U)=3.26(+0.19/-0.15) and v=1700(+600/-400) km/s, respectively. Four
emission lines were also detected in the soft energy band. The most likely
explanation for these emission lines is that they are associated with an
outflowing gas with a velocity of ~2000 km/s. The data suggest that the same
gas which is causing the absorption could also being responsible of these
emission features. Finally, the spectrum shows the presence of a relativistic
iron emission line likely originated in the accretion disc of a Kerr BH with an
inclination of ~25 deg. We propose a model to explain the observed X-ray
properties which invokes the presence of a two-phase outflow with cone-like
structure and a velocity of the order of 2,000-4,000 km/s. The inner layer of
the cone would be less ionised, or even neutral, than the outer layer. The
inclination angle would be lower than the opening angle of the outflowing cone.


title: Quantum Space-times: Beyond the Continuum of Minkowski and Einstein

abstract:
  In general relativity space-time ends at singularities. The big bang is
considered as the Beginning and the big crunch, the End. However these
conclusions are arrived at by using general relativity in regimes which lie
well beyond its physical domain of validity. Examples where detailed analysis
is possible show that these singularities are naturally resolved by quantum
geometry effects. Quantum space-times can be vastly larger than what Einstein
had us believe. These non-trivial space-time extensions enable us to answer of
some long standing questions and resolve of some puzzles in fundamental
physics. Thus, a century after Minkowski's revolutionary ideas on the nature of
space and time, yet another paradigm shift appears to await us in the wings.


title: Observation of Galactic Gamma-ray Sources with VERITAS

abstract:
  We report on VERITAS observations at energies above 200 GeV of known or
potential galactic gamma-ray sources. The observed objects comprise pulsars,
pulsar wind nebulae, high-mass X-ray binaries and gamma-ray sources with
unknown counterparts in other wavelengths. Among the highlights are the
observation of variable gamma-ray emission from the X-ray binary LS I +61 303
and the detection of MGRO J1906+06/HESS J1906+063, an extended gamma-ray source
which could not be associated with any obvious counterpart at lower energies.


title: Generation of Flavour Dependent Lepton Asymmetries in the E$_6$SSM

abstract:
  We calculate flavour dependent lepton asymmetries within the $E_6$ inspired
Supersymmetric Standard Model. Our analysis reveals that the substantial lepton
CP asymmetries can be induced even if $M_1\simeq 10^6 {GeV}$.


title:
Modelling the Global Solar Corona III: Origin of the Hemispheric Pattern
  of Filaments

abstract:
  We consider the physical origin of the hemispheric pattern of filament
chirality on the Sun. Our 3D simulations of the coronal field evolution over a
period of 6 months, based on photospheric magnetic measurements, were
previously shown to be highly successful at reproducing observed filament
chiralities. In this paper we identify and describe the physical mechanisms
responsible for this success. The key mechanisms are found to be (1)
differential rotation of north-south polarity inversion lines, (2) the shape of
bipolar active regions, and (3) evolution of skew over a period of many days.
As on the real Sun, the hemispheric pattern in our simulations holds in a
statistical sense. Exceptions arise naturally for filaments in certain
locations relative to bipolar active regions, or from interactions between a
number of active regions.


title: Coxeter group actions on 4F3(1) hypergeometric series

abstract:
  We investigate a certain linear combination $K(\vec{x})=K(a;b,c,d;e,f,g)$ of
two Saalschutzian hypergeometric series of type ${_4}F_3(1)$. We first show
that $K(a;b,c,d;e,f,g)$ is invariant under the action of a certain matrix group
$G_K$, isomorphic to the symmetric group $S_6$, acting on the affine hyperplane
$V=\{(a,b,c,d,e,f,g)\in\Bbb C^7\colon e+f+g-a-b-c-d=1\}$. We further develop an
algebra of three-term relations for $K(a;b,c,d;e,f,g)$. We show that, for any
three elements $\mu_1,\mu_2,\mu_3$ of a certain matrix group $M_K$, isomorphic
to the Coxeter group $W(D_6)$ (of order 23040), and containing the above group
$G_K$, there is a relation among $K(\mu_1\vec{x})$, $K(\mu_2\vec{x})$, and
$K(\mu_3\vec{x})$, provided no two of the $\mu_j$'s are in the same right coset
of $G_K$ in $M_K$. The coefficients in these three-term relations are seen to
be rational combinations of gamma and sine functions in $a,b,c,d,e,f,g$.
  The set of $({|M_K|/|G_K|\atop 3})=({32\atop 3})=4960$ resulting three-term
relations may further be partitioned into five subsets, according to the
Hamming type of the triple $(\mu_1,\mu_2,\mu_3) $ in question. This Hamming
type is defined in terms of Hamming distance between the $\mu_j$'s, which in
turn is defined in terms of the expression of the $\mu_j$'s as words in the
Coxeter group generators.
  Each three-term relation of a given Hamming type may be transformed into any
other of the same type by a change of variable. An explicit example of each of
the five types of three-term relations is provided.


title:
Anisotropy of tracer dispersion in rough model fractures with sheared
  walls

abstract:
  Dispersion experiments are compared for two transparent model fractures with
identical complementary rough walls but with a relative shear displacement
$\vec{\delta}$ parallel ($\vec{\delta}\parallel \vec{U}$) or perpendicular
($\vec{\delta} \perp \vec{U}$) to the flow velocity $\vec{U}$. The structure of
the mixing front is characterized by mapping the local normalized local transit
time $\bar t(x,y)$ and dispersivity $\alpha(x,y)$. For $\vec{\delta} \perp
\vec{U}$, displacement fronts display large fingers: their geometry and the
distribution of $\bar t(x,y)U/x$ are well reproduced by assuming parallel
channels of hydraulic conductance deduced from the aperture field. For
$\vec{\delta} \parallel \vec{U}$, the front is flatter and $\alpha(x,y)$
displays a narrow distribution and a Taylor-like variation with $Pe$.


title:
Gamma Ray Burst Section of the White Paper on the Status and Future of
  Ground-based TeV Gamma-ray Astronomy

abstract:
  This is a report on the findings of the gamma ray burst working group for the
white paper on the status and future of TeV gamma-ray astronomy. The white
paper is an APS commissioned document, and the overall version has also been
released and can be found on astro-ph. This detailed section of the white paper
discusses the status of past and current attempts to observe gamma ray bursts
at GeV-TeV energies. We concentrate on the potential of future ground-based
gamma-ray experiments to observe the highest energy emission ever recorded for
GRBs, particularly for those that are nearby and have high Lorentz factors in
the GRB jet. It is clear that major advances are possible and that the
detection of very high energy emission would have strong implications for GRB
models, as well as cosmic ray origin.


title:
Characterizing Entanglement Entropy Produced by Non-Linear Scalar
  Interactions During Inflation

abstract:
  The density fluctuations that we observe in the universe today are thought to
originate from quantum fluctuations produced during a phase of the early
universe called inflation. By evolving a wavefunction describing two coupled
Fourier modes of a scalar field forward through an inflationary epoch, we
demonstrate that non-linear effects can result in a generation of entanglement
entropy between modes with different momenta in a scalar field during the
inflationary period when just one of the modes is observed. Through this
mechanism, the field would experience decoherence and appear more like a
classical distribution today; however the mechanism is not sufficiently
efficient to explain classicality. We find that the amount of entanglement
entropy generated scales roughly as a power law S \propto \lambda^{1.75}, where
\lambda is the coupling coefficient of the non-linear potential term. We also
investigate how the entanglement entropy scales with the duration of inflation
and compare various entanglement measures from the literature with the von
Neumann entropy. This demonstration explicitly follows particle creation and
interactions between modes; consequently, the mechanism contributing to the
generation of the von Neumann entropy can be easily seen.


title:
Boundary estimates for positive solutions to second order elliptic
  equations

abstract:
  Consider positive solutions to second order elliptic equations with
measurable coefficients in a bounded domain, which vanish on a portion of the
boundary. We give simple necessary and sufficient geometric conditions on the
domain, which guarantee the Hopf-Oleinik type estimates and the boundary
Lipschitz estimates for solutions. These conditions are sharp even for harmonic
functions.


title: Pairing on striped $t$-$t'$-$J$ lattices

abstract:
  Results are given from a density matrix renormalization group study of
pairing on a striped $t$-$t'$-$J$ lattice in the presence of boundary magnetic
and pair fields. We find that pairing on a stripe depends sensitively on both
$J/t$ and $t'/t$. In the strong-pairing model-parameter regime the stripes are
easily coupled by the pair field, and have a uniform phase. There is a small
but measurable energy cost to create anti-phase superconducting domain walls.


title: Cosmological Constant in SUGRA Models Inspired by Degenerate Vacua

abstract:
  It is well known that global symmetries protect local supersymmetry and a
zero value for the cosmological constant in no--scale supergravity. A
particular breakdown of these symmetries, which ensures the vanishing of the
vacuum energy density, leads to the natural realisation of the multiple point
principle (MPP). In the MPP inspired SUGRA models the cosmological constant is
naturally tiny.


title: The fate of black branes in Einstein-Gauss-Bonnet gravity

abstract:
  Black branes are studied in Einstein-Gauss-Bonnet (EGB) gravity. Evaporation
drives black branes towards one of two singularities depending on the sign of
$\alpha$, the Gauss-Bonnet coupling. For positive $\alpha$ and sufficiently
large ratio $\sqrt{\alpha}/L$, where $L/2\pi$ is the radius of
compactification, black branes avoid the Gregory-Laflamme (GL) instability
before reaching a critical state. No black branes with the radius of horizon
smaller than the critical value can exist. Approaching the critical state
branes have a nonzero Hawking temperature. For negative $\alpha$ all black
branes encounter the GL instability. No black branes may exist outside of the
interval of the critical values, $0\leq\beta<3$, where $\beta=1- 8\alpha/r_h^2$
and $r_h$ is the radius of horizon of the black brane. The first order phase
transition line of GL transitions ends in a second order phase transition point
at $\beta=0$.


title: Jet Formation in MHD Simulations

abstract:
  In this talk I review the current status of jet formation in direct numerical
simulations of black-hole accretion disks and magnetospheres. I address the
following critical questions: What constitutes the jet? What is the launching
mechanism? Where is the launching point of the jet? What is the Lorentz factor?
What is the opening angle? How is the jet collimated? Just as importantly, I
also discuss how dependent the answers to the above questions are on factors
such as the initial conditions of the simulation. I end by discussing possible
future directions for this research.


title:
Supersymmetric solutions of gauged five-dimensional supergravity with
  general matter couplings

abstract:
  We perform the characterization program for the supersymmetric configurations
and solutions of the $\mathcal{N}=1$, $d=5$ Supergravity Theory coupled to an
arbitrary number of vectors, tensors and hypermultiplets and with general
non-Abelian gaugins. By using the conditions yielded by the characterization
program, new exact supersymmetric solutions are found in the $SO(4,1)/SO(4)$
model for the hyperscalars and with $SU(2)\times U(1)$ as the gauge group. The
solutions also content non-trivial vector and massive tensor fields, the latter
being charged under the U(1) sector of the gauge group and with selfdual
spatial components. These solutions are black holes with $AdS_2 \times S^3$
near horizon geometry in the gauged version of the theory and for the ungauged
case we found naked singularities. We also analyze supersymmetric solutions
with only the scalars $\phi^x$ of the vector/tensor multiplets and the metric
as the non-trivial fields. We find that only in the null class the scalars
$\phi^x$ can be non-constant and for the case of constant $\phi^x$ we refine
the classification in terms of the contributions to the scalar potential.


title: Clustering of Dust-Obscured Galaxies at z ~ 2

abstract:
  We present the angular autocorrelation function of 2603 dust-obscured
galaxies (DOGs) in the Bootes field of the NOAO Deep Wide-Field Survey. DOGs
are red, obscured galaxies, defined as having R-[24] \ge 14 (F_24/F_R \ga
1000). Spectroscopy indicates that they are located at 1.5 \la z \la 2.5. We
find strong clustering, with r_0 = 7.40^{+1.27}_{-0.84} Mpc/h for the full F_24
> 0.3 mJy sample. The clustering and space density of the DOGs are consistent
with those of submillimeter galaxies, suggestive of a connection between these
populations. We find evidence for luminosity-dependent clustering, with the
correlation length increasing to r_0 = 12.97^{+4.26}_{-2.64} Mpc/h for brighter
(F_24 > 0.6 mJy) DOGs. Bright DOGs also reside in richer environments than
fainter ones, suggesting these subsamples may not be drawn from the same parent
population. The clustering amplitudes imply average halo masses of log M =
12.2^{+0.3}_{-0.2} Msun for the full DOG sample, rising to log M =
13.0^{+0.4}_{-0.3} Msun for brighter DOGs. In a biased structure formation
scenario, the full DOG sample will, on average, evolve into ~ 3 L* present-day
galaxies, whereas the most luminous DOGs may evolve into brightest cluster
galaxies.


title: Galaxy Clusters at 0.9<z<1.7 in the AKARI NEP deep field

abstract:
  There is a huge gap between properties of red-sequence selected massive
galaxy clusters at z<1 and Lyman-break selected proto-clusters at z>3. It is
important to understand when and how the z>3 proto-clusters evolve into passive
clusters at z<1.
  We aim to fill this cluster desert by using the space-based N4(4um) imaging
with the AKARI. The z'-N4 color is a powerful separator of cluster galaxies at
z>1, taking advantage of the 4000A break and the 1.6um bump. We carefully
selected 16 promising cluster candidates at 0.9<z<1.7, which all show obvious
over-density of galaxies and a prominent red-sequence.
  At this redshift range, the mid-infrared S15um/S9um flux ratio is an
extinction-free indicator of galaxy star formation activity due to the
redshifted PAH emission lines (6.2,7.7 and 8.6um). We show statistically that
the cluster galaxies have a lower S15um/S9um flux ratio than field galaxies,
i.e., cluster galaxies already have lower star-formation activity at 0.9<z<1.7,
pushing the formation epoch of these galaxy clusters to a higher redshift.


title:
A Catalog of Extended Green Objects (EGOs) in the GLIMPSE Survey: A new
  sample of massive young stellar object outflow candidates

abstract:
  Using images from the Spitzer GLIMPSE Legacy survey, we have identified more
than 300 extended 4.5 micron sources (abbreviated EGO, Extended Green Object,
for the common coding of the [4.5] band as green in 3-color composite IRAC
images). We present a catalog of these EGOs, including integrated flux density
measurements at 3.6, 4.5, 5.8, 8.0, and 24 microns from the GLIMPSE and MIPSGAL
surveys. The average angular separation between a source in our sample and the
nearest IRAS point source is >1 arcminute. The majority of EGOs are associated
with infrared dark clouds (IRDCs), and where high-resolution 6.7 GHz methanol
maser surveys overlap the GLIMPSE coverage, EGOs and 6.7 GHz methanol masers
are strongly correlated. Extended 4.5 micron emission is thought to trace
shocked molecular gas in protostellar outflows; the association of EGOs with
IRDCs and 6.7 GHz methanol masers suggests that extended 4.5 micron emission
may pinpoint outflows specifically from massive protostars. The mid-infrared
colors of EGOs lie in regions of color-color space occupied by young protostars
still embedded in infalling envelopes.


title:
Tunneling magnetoresistance of Fe/ZnSe (001) single- and double-barrier
  junctions as a function of interface structure

abstract:
  In this contribution, we calculate the spin-dependent ballistic and coherent
transport through epitaxial Fe/ZnSe (001) simple and double magnetic tunnel
junctions with two different interface terminations: Zn-terminated and
Se-terminated. The electronic structure of the junctions is modeled by a
second-nearest neighbors {\it spd} tight-binding Hamiltonian parametrized to
{\it ab initio} calculated band structures, while the conductances and the
tunneling magnetoresistance are calculated within Landauer's formalism. The
calculations are done at zero bias voltage and as a function of energy. We show
and discuss the influence of the interface structure on the spin-dependent
transport through simple and double tunnel junctions.


title: Three New Complexity Results for Resource Allocation Problems

abstract:
  We prove the following results for task allocation of indivisible resources:
  - The problem of finding a leximin-maximal resource allocation is in P if the
agents have max-utility functions and atomic demands.
  - Deciding whether a resource allocation is Pareto-optimal is coNP-complete
for agents with (1-)additive utility functions.
  - Deciding whether there exists a Pareto-optimal and envy-free resource
allocation is Sigma_2^p-complete for agents with (1-)additive utility
functions.


title: The Nemo-3 Experiment and the Supernemo Project

abstract:
  The NEMO experiment is investigating the neutrinoless double beta decay. The
NEMO-3 detector is taking data in the Frejus Underground Laboratory. The goal
of the SuperNEMO detector is to reach a sensitivity on the order of 10^26 year
on the half-life of the bb0nu process. The chosen isotopes for the future
detector are 82Se and 150Nd, because of the reduced background. The
collaboration has started a 3-year R&D development on all components : tracking
detector, calorimeter, source enrichment and purification, radiopurity
measurements.


title: Quantum Illumination with Gaussian States

abstract:
  An optical transmitter irradiates a target region containing a bright
thermal-noise bath in which a low-reflectivity object might be embedded. The
light received from this region is used to decide whether the object is present
or absent. The performance achieved using a coherent-state transmitter is
compared with that of a quantum illumination transmitter, i.e., one that
employs the signal beam obtained from spontaneous parametric downconversion
(SPDC). By making the optimum joint measurement on the light received from the
target region together with the retained SPDC idler beam, the quantum
illumination system realizes a 6 dB advantage in error probability exponent
over the optimum reception coherent-state system. This advantage accrues
despite there being no entanglement between the light collected from the target
region and the retained idler beam.


title:
Modification to the Luminosity Distance Redshift Relation in Modified
  Gravity Theories

abstract:
  We derive an expression for the luminosity distance as a function of redshift
for a flat Robertson-Walker spacetime perturbed by arbitrary scalar
perturbations possibly produced by a modified gravity theory with two different
scalar perturbation potentials. Measurements of the luminosity distance as
function of redshift provide a constraint on a combination of the scalar
potentials and so they can complement weak lensing and other measurements in
trying to distinguish among the various alternative theories of gravity.


title:
Critical points in a relativistic bosonic gas induced by the quantum
  structure of spacetime

abstract:
  It is well known that phase transitions arise if the interaction among
particles embodies an attractive as well as a repulsive contribution. In this
work it will be shown that the breakdown of Lorentz symmetry, characterized
through a deformation in the relation dispersion, plus the bosonic statistics
predict the emergence of critical points. In other words, in some quantum
gravity models the structure of spacetime implies the emergence of critical
points even when no interaction among the particle has been considered.


title: Modular properties of Eisenstein series and statistical physics

abstract:
  The temperature inversion properties of the internal energy, E, on odd
spheres, and its derivatives, together with their expression in elliptic terms,
as expounded in previous papers, are extended to the integrals of E, thence
making contact with the theory of modular forms with rational period functions.
  I point out that the period functions of (holomorphic) Eisenstein series
computed by Zagier were already available since the time of Ramanujan and I
give a rederivation by contour integration. Removing both the Planck and
Casimir terms gives a fully subtracted form of the series which allows a more
elegant and compact treatment. I expound the relation to Eichler cohomology
cocycles and also rewrite the theory in a distributional, Green function way.
Some historical and technical developments of the Selberg--Chowla formula are
presented, and it is suggested that this be renamed the Epstein--Kober formula.
On another point of historical justice, the work of Koshliakov on Dirichlet
series is reprised. A representation of a `massive' generalised Dirchlet series
due to Berndt is also reproved, applied to the Epstein series and to a
derivation of the standard statistical mode sum, interpreted as a Kronecker
limit formula.


title: Valley splitting in a Si/SiGe quantum point contact

abstract:
  We present the theory and measurement of valley splitting in a quantum point
contact (QPC) in a modulation doped Si/SiGe heterostructure. Our measurements
are performed on a submicron Schottky-gated device. An effective mass theory is
developed for a QPC formed in a quantum well, grown on a miscut substrate. Both
theory and experiments include a perpendicular magnetic field. Our results
indicate that both QPC and magnetic confinement can enhance the valley
splitting by reducing the spatial extent of the electronic wavefunction.
Consequently, the valley splitting can be much larger than the spin splitting
for small magnetic fields. We also observe different valley splittings for
different transverse modes in the QPC, supporting the notion that when steps
are present at the quantum well interface, the spatial extent of the
wavefunction plays a dominant role in determining the valley splitting.


title:
Connection between matrix-product states and superposition of Bernoulli
  shock measures

abstract:
  We consider a generalized coagulation-decoagulation system on a
one-dimensional discrete lattice with reflecting boundaries. It is known that a
Bernoulli shock measure with two shock fronts might have a simple random-walk
dynamics, provided that some constraints on the microscopic reaction rates of
this system are fulfilled. Under these constraints the steady-state of the
system can be written as a linear superposition of such shock measures. We show
that the coefficients of this expansion can be calculated using the
finite-dimensional representation of the quadratic algebra of the system
obtained from a matrix-product approach.


title: The Production of Neutral Bilepton Bosons in Proton-Proton Collisions

abstract:
  We establish some signatures of the extra bilepton boson ${X^0}$ predicted in
the ${SU (3)_C \times SU (3)_L \times U (1)_X}$ model with right-handed
neutrinos. We analyze the process $p + p \longrightarrow X^0 +X^{0*} + {\hbox
{anything}}$, for center of mass energy regime of the Large Hadron Collider.
The main contributions for the neutral bilepton production in $q \bar q$
process come from the $s-$channel ($Z$ and $Z^\prime$ exchanges), when the
initial quarks have charge 2/3, and from an additional $t-$channel (heavy quark
exchange) when they have -1/3 of the positron electric charge. We calculate
some distributions of the final bileptons and from these results we conclude
that LHC can show a clear signature for the existence of the $X^0$ predicted in
the 3-3-1 model.


title:
On the efficiency of nondegenerate quantum error correction codes for
  Pauli channels

abstract:
  We examine the efficiency of pure, nondegenerate quantum-error
correction-codes for Pauli channels. Specifically, we investigate if correction
of multiple errors in a block is more efficient than using a code that only
corrects one error per block. Block coding with multiple-error correction
cannot increase the efficiency when the qubit error-probability is below a
certain value and the code size fixed. More surprisingly, existing
multiple-error correction codes with a code length equal or less than 256
qubits have lower efficiency than the optimal single-error correcting codes for
any value of the qubit error-probability. We also investigate how efficient
various proposed nondegenerate single-error correcting codes are compared to
the limit set by the code redundancy and by the necessary conditions for
hypothetically existing nondegenerate codes. We find that existing codes are
close to optimal.


title:
Polaron Recombination in Pristine and Annealed Bulk Heterojunction Solar
  Cells

abstract:
  We determined the dominant polaron recombination loss mechanism in pristine
and annealed polythiophene:fullerene blend solar cells by applying the
photo-induced charge extraction by linearly increasing voltage (photo-CELIV)
method in dependence on temperature. In pristine samples, we find a strongly
temperature dependent bimolecular polaron recombination rate, which is reduced
as compared to the Langevin theory. For the annealed sample, we observe a
polaron decay rate which follows a third order of carrier concentration almost
temperature independently.


title: Semileptonic decays in the limit of a heavy daughter quark

abstract:
  The rate of the semileptonic decay b to c l v is calculated with order
alphas^2 accuracy, as an expansion around the limit of equal masses of the b
and c quarks. Recent results obtained around the limit of the c-quark much
lighter than b are confirmed. Details of the new expansion method are
described.


title: An extreme EXO: a type 2 QSO at z=1.87

abstract:
  We aim to understand the multi-wavelength properties of 2XMM J123204+215255,
the source with the most extreme X-ray-to-optical flux ratio amongst a sample
of bright X-ray selected EXOs drawn from a cross-correlation of the 2XMMp
catalogue with the SDSS-DR5 catalogue. We use 2XMMp X-ray data, SDSS-DR5, NOT
and UKIRT optical/NIR photometric data and Subaru MOIRCS IR spectroscopy to
study the properties of 2XMM J123204+215255. We created a model SED including
an obscured QSO and the host galaxy component to constrain the optical/IR
extinction and the relative contribution of the AGN and the galaxy to the total
emission. 2XMM J123204+215255 is a bright X-ray source with f_X~10^{-12} erg
cm^{-2} s^{-1} (2-10 keV energy band) which has no detection down to a
magnitude i' > 25.2. NIR imaging reveals a faint K-band counterpart and NIR
spectroscopy shows a single broad (FWHM=5300 km/s) emission line, which is
almost certainly H-alpha at z=1.87. The X-ray spectrum shows evidence of
significant absorption (N_H > 10^{23} cm^{-2}), typical of type 2 AGN, but the
broad H-alpha emission suggests a type 1 AGN classification. The very red
optical/NIR colours (i'-K > 5.3) strongly suggest significant reddening
however. We find that simple modelling can successfully reproduce the NIR
continuum and strongly constrain the intrinsic nuclear optical/IR extinction to
A_V~4, which turns out to be much smaller than the expected from the X-ray
absorption (assuming Galactic gas-to-dust ratio).


title: Phase Referencing in Optical Interferometry

abstract:
  One of the aims of next generation optical interferometric instrumentation is
to be able to make use of information contained in the visibility phase to
construct high dynamic range images. Radio and optical interferometry are at
the two extremes of phase corruption by the atmosphere. While in radio it is
possible to obtain calibrated phases for the science objects, in the optical
this is currently not possible. Instead, optical interferometry has relied on
closure phase techniques to produce images. Such techniques allow only to
achieve modest dynamic ranges. However, with high contrast objects, for faint
targets or when structure detail is needed, phase referencing techniques as
used in radio interferometry, should theoretically achieve higher dynamic
ranges for the same number of telescopes. Our approach is not to provide
evidence either for or against the hypothesis that phase referenced imaging
gives better dynamic range than closure phase imaging. Instead we wish to
explore the potential of this technique for future optical interferometry and
also because image reconstruction in the optical using phase referencing
techniques has only been performed with limited success. We have generated
simulated, noisy, complex visibility data, analogous to the signal produced in
radio interferometers, using the VLTI as a template. We proceeded with image
reconstruction using the radio image reconstruction algorithms contained in
AIPS IMAGR (CLEAN algorithm). Our results show that image reconstruction is
successful in most of our science cases, yielding images with a 4
milliarcsecond resolution in K band. (abridged)


title: Recent Developments in Dual Lattice Algorithms

abstract:
  We review recent progress in numerical simulations with dually transformed
SU(2) LGT, starting with a discussion of explicit dual amplitudes and
algorithms for SU(2) pure Yang Mills in D=3 and D=4. In the D=3 case, we
discuss results that validate the dual algorithm against conventional
simulations. We also review how a local, exact dynamical fermion algorithm can
naturally be incorporated into the dual framework. We conclude with an outlook
for this technique and a look at some of the current challenges we've
encountered with this method, specifically critical slowing down and the sign
problem.


title:
Quantum Monte Carlo calculations of magnetic moments and M1 transitions
  in A<=7 nuclei including meson-exchange currents

abstract:
  Green's function Monte Carlo calculations of magnetic moments and M1
transitions including two-body meson-exchange current (MEC) contributions are
reported for A<=7 nuclei. The realistic Argonne v18 two-nucleon and Illinois-2
three-nucleon potentials are used to generate the nuclear wave functions. The
two-body meson-exchange operators are constructed to satisfy the continuity
equation with the Argonne v18 potential. The MEC contributions increase the
A=3,7 isovector magnetic moments by 16% and the A=6,7 M1 transition rates by
17--34%, bringing them into very good agreement with the experimental data.


title: pi+ pi+, K+ K+ and B B Interactions

abstract:
  The most recent calculations of pi+ pi+ and K+ K+ scattering by the NPLQCD
collaboration using domain-wall valence quarks on staggered MILC configurations
are presented. In addition, a quenched calculation of the potentials between
two B-mesons is discussed.


title: Phase Closure Image Reconstruction for Future VLTI Instrumentation

abstract:
  Classically, optical and near-infrared interferometry have relied on closure
phase techniques to produce images. Such techniques allow us to achieve modest
dynamic ranges. In order to test the feasibility of next generation optical
interferometers in the context of the VLTI-spectro-imager (VSI), we have
embarked on a study of image reconstruction and analysis. Our main aim was to
test the influence of the number of telescopes, observing nights and
distribution of the visibility points on the quality of the reconstructed
images. Our results show that observations using six Auxiliary Telescopes (ATs)
during one complete night yield the best results in general and is critical in
most science cases; the number of telescopes is the determining factor in the
image reconstruction outcome. In terms of imaging capabilities, an optical, six
telescope VLTI-type configuration and ~200 meter baseline will achieve 4 mas
spatial resolution, which is comparable to ALMA and almost 50 times better than
JWST will achieve at 2.2 microns. Our results show that such an instrument will
be capable of imaging, with unprecedented detail, a plethora of sources,
ranging from complex stellar surfaces to microlensing events.


title: Nonexistence of Entanglement Sudden Death in High NOON States

abstract:
  We study the dynamics of entanglement in continuous variable quantum systems
(CVQS). Specifically, we study the phenomena of Entanglement Sudden Death (ESD)
in general two-mode-N-photon states undergoing pure dephasing. We show that for
these states, ESD never occurs. These states are generalizations of the
so-called High NOON states, shown to decrease the Rayleigh limit of lambda to
lambda/N, which promises great improvement in resolution of interference
patterns if states with large N are physically realized. However, we show that
in dephasing NOON states, the time to reach V_crit, critical visibility, scales
inversely with N^2. On the practical level, this shows that as N increases, the
visibility degrades much faster, which is likely to be a considerable drawback
for any practical application of these states.


title: Top Quark Pair Production Cross-Section Measurements at DO

abstract:
  We present recent measurements of the top quark pair production cross-section
in the dilepton, lepton+jets and lepton+tau final states with the D0 detector
in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV.


title: Superexchange-Driven Magnetoelectricity in Magnetic Vortices

abstract:
  We demonstrate that magnetic vortices in which spins are coupled to polar
lattice distortions via superexchange exhibit an unusually large linear
magnetoelectric response. We show that the periodic arrays of vortices formed
by frustrated spins on Kagom\'e lattices provide a realization of this concept;
our {\it ab initio} calculations for such a model structure yield a
magnetoelectric coefficient that is 30 times larger than that of prototypical
single phase magnetoelectrics. Finally, we identify the design rules required
to obtain such a response in a practical material.


title: Measurement of the Inclusive Isolated Photon Cross Section at CDF

abstract:
  We present preliminary results on inclusive direct photon production in
$p\bar{p}$ collisions at $\sqrt{s}$=1.96 TeV, using data collected with the
upgraded Collider Detector at Fermilab in Run II, corresponding to an
integrated luminosity of 451 pb$^{-1}$. Measurements are performed as a
function of the photon transverse momentum for photons with $p_{T}>$30 GeV and
$|\eta|<$1.0. Photons are required to be isolated in the calorimeter. The
measurement is corrected to the hadron level and compared to NLO pQCD
predictions.


title: On the Corporate Votes and their relation with Daisy Models

abstract:
  The distribution of votes of one of the corporate parties in Mexico during
elections of 2000, 2003 and 2006 is analyzed. After proper normalization and
unfolding the agreement of the votes distributions with those of daisy models
of several ranks is good. These models are generated by retaining each $r+1$
level in a sequence which follows a Poisson distribution.Beyond the fact that
rank 2 daisy model resembles the distribution of the quasi-optimal distances
for the Traveling Salesman Problem no clear explanation exists for this
behavior, but the agreement is not fortuitous and the possibility of a
universal phenomena for corporate vote is discussed.


title: CFHTLS weak-lensing constraints on the neutrino masses

abstract:
  We use measurements of cosmic shear from CFHTLS, combined with WMAP-5 cosmic
microwave background anisotropy data, baryonic acoustic oscillations from SDSS
and 2dFGRS and supernovae data from SNLS and Gold-set, to constrain the
neutrino mass. We obtain a 95% confidence level upper limit of 0.54 eV for the
sum of the neutrino masses, and a lower limit of 0.03 eV. The preference for
massive neutrinos vanishes when shear-measurement systematics are included in
the analysis.


title: Generalized dKP: Manakov-Santini hierarchy and its waterbag reduction

abstract:
  We study Manakov-Santini equation, starting from Lax-Sato form of associated
hierarchy. The waterbag reduction for Manakov-Santini hierarchy is introduced.
Equations of reduced hierarchy are derived.We construct new coordinates
transforming non-hydrodynamic evolution of waterbag reduction to
non-homogeneous Riemann invariants form of hydrodynamic type.


title: Re`class'ification of `quant'ified classical simulated annealing

abstract:
  We discuss a classical reinterpretation of quantum-mechanics-based analysis
of classical Markov chains with detailed balance, that is based on the
quantum-classical correspondence. The classical reinterpretation is then used
to demonstrate that it successfully reproduces a sufficient condition for
cooling schedule in classical simulated annealing, which has the
inverse-logarithmic scaling.


title: The Ratio Index for Budgeted Learning, with Applications

abstract:
  In the budgeted learning problem, we are allowed to experiment on a set of
alternatives (given a fixed experimentation budget) with the goal of picking a
single alternative with the largest possible expected payoff. Approximation
algorithms for this problem were developed by Guha and Munagala by rounding a
linear program that couples the various alternatives together. In this paper we
present an index for this problem, which we call the ratio index, which also
guarantees a constant factor approximation. Index-based policies have the
advantage that a single number (i.e. the index) can be computed for each
alternative irrespective of all other alternatives, and the alternative with
the highest index is experimented upon. This is analogous to the famous Gittins
index for the discounted multi-armed bandit problem.
  The ratio index has several interesting structural properties. First, we show
that it can be computed in strongly polynomial time. Second, we show that with
the appropriate discount factor, the Gittins index and our ratio index are
constant factor approximations of each other, and hence the Gittins index also
gives a constant factor approximation to the budgeted learning problem.
Finally, we show that the ratio index can be used to create an index-based
policy that achieves an O(1)-approximation for the finite horizon version of
the multi-armed bandit problem. Moreover, the policy does not require any
knowledge of the horizon (whereas we compare its performance against an optimal
strategy that is aware of the horizon). This yields the following surprising
result: there is an index-based policy that achieves an O(1)-approximation for
the multi-armed bandit problem, oblivious to the underlying discount factor.


title:
Blaschke's problem for timelike surfaces in pseudo-Riemannian space
  forms

abstract:
  We show that isothermic surfaces and S-Willmore surfaces are also the
solutions to the corresponding Blaschke's problem for both spacelike and
timelike surfaces in pseudo-Riemannian space forms. For timelike surfaces both
Willmore and isothermic, we obtain a description by minimal surfaces similar to
the classical results of Thomsen.


title:
Dynamical Opacity-Sampling Models of Mira Variables. I: Modelling
  Description and Analysis of Approximations

abstract:
  We describe the Cool Opacity-sampling Dynamic EXtended (CODEX) atmosphere
models of Mira variable stars, and examine in detail the physical and numerical
approximations that go in to the model creation. The CODEX atmospheric models
are obtained by computing the temperature and the chemical and radiative states
of the atmospheric layers, assuming gas pressure and velocity profiles from
Mira pulsation models, which extend from near the H-burning shell to the outer
layers of the atmosphere. Although the code uses the approximation of Local
Thermodynamic Equilibrium (LTE) and a grey approximation in the dynamical
atmosphere code, many key observable quantities, such as infrared diameters and
low-resolution spectra, are predicted robustly in spite of these
approximations. We show that in visible light, radiation from Mira variables is
dominated by fluorescence scattering processes, and that the LTE approximation
likely under-predicts visible-band fluxes by a factor of two.


title:
Algebraic Methods for Inferring Biochemical Networks: a Maximum
  Likelihood Approach

abstract:
  We present a novel method for identifying a biochemical reaction network
based on multiple sets of estimated reaction rates in the corresponding
reaction rate equations arriving from various (possibly different) experiments.
The current method, unlike some of the graphical approaches proposed in the
literature, uses the values of the experimental measurements only relative to
the geometry of the biochemical reactions under the assumption that the
underlying reaction network is the same for all the experiments.
  The proposed approach utilizes algebraic statistical methods in order to
parametrize the set of possible reactions so as to identify the most likely
network structure, and is easily scalable to very complicated biochemical
systems involving a large number of species and reactions. The method is
illustrated with a numerical example of a hypothetical network arising form a
"mass transfer"-type model.


title:
Recollimation and Radiative Focusing of Relativistic Jets: Applications
  to Blazars and M87

abstract:
  Recent observations of M87 and some blazars reveal violent activity in small
regions located at relatively large distances from the central engine.
Motivated by these considerations, we study the hydrodynamic collimation of a
relativistic cooling outflow using a semi-analytical model developed earlier.
We first demonstrate that radiative cooling of the shocked outflow layer can
lead to a focusing of the outflow and its reconfinement in a region having a
very small cross-sectional radius. Such a configuration can produce rapid
variability at large distances from the central engine via reflections of the
converging recollimation shock. Possible applications of this model to TeV
blazars are discussed. We then apply our model to M87. The low radiative
efficiency of the M87 jet renders focusing unlikely. However, the shallow
profile of the ambient medium pressure inferred from observations, results in
extremely good collimation that can explain the reported variability of the
X-ray flux emitted from the HST-1 knot.


title: 2+1 flavor lattice QCD simulation with $O(a)$-improved Wilson quarks

abstract:
  We present simulation details and results for the light hadron spectrum in N
f = 2 + 1 lattice QCD with the nonperturbatively O(a)-improved Wilson quark
action and the Iwasaki gauge action. Simulations are carried out at a lattice
spacing of 0.09 fm on a (2.9fm)^3 box using the PACS-CS computer. We employ the
Luscher's domain-decomposed HMC algorithm with several improvements to reduce
the degenerate up-down quark mass toward the physical value. So far the
resulting pseudoscalar meson mass is ranging from 702MeV down to 156MeV. We
discuss on the stability and the efficiency of the algorithm. The light harden
spectrum extrapolated at the physical point is compared with the experimental
values. We also present the values of the quark masses and the pseudoscalar
meson decay constants.


title: Hanohano:A Deep Ocean Antineutrino Observatory

abstract:
  This paper presents the science potential of a deep ocean antineutrino
observatory being developed at Hawaii and elsewhere. The observatory design
allows for relocation from one site to another. Positioning the observaory some
60 km distant from a nuclear reactor complex enables preecision measurement of
neutrino mixing parameters, leading to a determination of neutrino mass
hierarchy and theta_13. At a mid-Pacific location, the observatory measures the
flux of uranium and thorium decay series antineutrinos from earth's mantle and
performs a sensitive search for a hypothetical natural fission reactor in
earth's core. A subequent deployment at another mid-ocean location would test
lateral homogeneity of uranium and thorium in earth's mantle. These
measurements have significance for earth energy studies.


title: Quantum Teleportation of Light

abstract:
  Requirements for the successful teleportation of a beam of light, including
its temporal correlations, are discussed. Explicit expressions for the degrees
of first- and second-order optical coherence are derived. Teleportation of an
antibunched photon stream illustrates our results.


title: Charmless Three-body $B$ Decays at BABAR

abstract:
  We present Dalitz-plot analyses of $B^+\to K^+\pi^-\pi^+$ and $B^0\to
K^+\pi^-\pi^0$ using the data sample collected at the $\Upsilon(4S)$ by the
BABAR detector. We have found evidence for direct CP-violation in the decay
$B^\pm\to\rho^0 K^\pm$, with a CP-violation parameter ${\cal
A}_{CP}={\Gamma_{B^+}-\Gamma_{B^-}\over \Gamma_{B^+}+\Gamma_{B^-}}=
(+44\pm10\pm4^{+5}_{-13})%$, where $\Gamma_{B^\pm}$ are the decay rates. The
uncertainties are statistical, systematic, and model-dependent, respectively.
We also search for the suppressed decays $B^+\to K^-\pi^+\pi^+$ and
$K^+K^+\pi^-$ and improve upper limits on the decay branching fractions.


title:
Reed-Solomon Subcodes with Nontrivial Traces: Distance Properties and
  Soft-Decision Decoding

abstract:
  Reed-Solomon (RS) codes over GF$(2^m)$ have traditionally been the most
popular non-binary codes in almost all practical applications. The distance
properties of RS codes result in excellent performance under hard-decision
bounded-distance decoding. However, efficient and implementable soft decoding
for high-rate (about 0.9) RS codes over large fields (GF(256), say) continues
to remain a subject of research with a promise of further coding gains. In this
work, our objective is to propose and investigate $2^m$-ary codes with
non-trivial binary trace codes as an alternative to RS codes. We derive bounds
on the rate of a $2^m$-ary code with a non-trivial binary trace code. Then we
construct certain subcodes of RS codes over GF($2^m$) that have a non-trivial
binary trace with distances and rates meeting the derived bounds. The
properties of these subcodes are studied and low-complexity hard-decision and
soft-decision decoders are proposed. The decoders are analyzed, and their
performance is compared with that of comparable RS codes. Our results suggest
that these subcodes of RS codes could be viable alternatives for RS codes in
applications.


title: Finite simple groups with narrow prime spectrum

abstract:
  We find the nonabelian finite simple groups with order prime divisors not
exceeding 1000. More generally, we determine the sets of nonabelian finite
simple groups whose maximal order prime divisor is a fixed prime less than
1000. Our results are based on calculations in the computer algebra system GAP.


title: Ultracool Subdwarfs: The Halo Population Down to the Substellar Limit

abstract:
  Ultracool subdwarfs are low luminosity, late-type M and L dwarfs that exhibit
spectroscopic indications of subsolar metallicity and halo kinematics. Their
recent discovery and ongoing investigation have led to new insights into the
role of metallicity in the opacity structure, chemistry (e.g. dust formation)
and evolution of low-temperature atmospheres; the long-term evolution of
magnetic activity and angular momentum amongst the lowest-mass stars; the form
of the halo luminosity and mass functions down to the hydrogen-burning mass
limit; and even fundamental issues such as spectral classification and absolute
brightness scales. This Splinter Session was devoted to bringing advances in
observational and theoretical ultracool subdwarf research to the attention of
the low-mass stellar and brown dwarf communities, as well as to share results
among ultracool subdwarf enthusiasts.


title:
Clouds, Brightening and Multiplicity Across the L Dwarf/T Dwarf
  Transition

abstract:
  The transition between the two lowest-luminosity spectral classes of brown
dwarfs--the L dwarfs and T dwarfs--is traversed by nearly all brown dwarfs as
they cool over time. Yet distinct features of this transition, such as the
"J-band bump" and an unusually high rate of multiplicity, remain outstanding
problems, although evidence points to condensate cloud evolution as a critical
component. Using a Monte Carlo population simulation that incorporates the
empirical spectral properties of unresolved brown dwarfs in magnitude-limited
samples, I demonstrate that the J-band bump and enhanced multiplicity naturally
emerge from a short timescale of photospheric cloud dissipation. This timescale
may help constrain future evolutionary models exploring the cloud dissipation
process.


title:
Study of the process e+e-\to \mu+\mu- in the energy region \sqrt{s}=980,
  1040 -- 1380 MeV

abstract:
  The cross section of the process e+e-\to\mu+\mu- was measured in the SND
experiment at the VEPP-2M e+e- collider in the energy region \sqrt{s}=980, 1040
-- 1380 MeV. The event numbers of the process e+e-\to\mu+\mu- were normalized
to the integrated luminosity measured using e+e-\to e+e- and
e+e-\to\gamma\gamma processes. The ratio of the measured cross section to the
theoretically predicted value is 1.006\pm 0.007 \pm 0.016 and 1.005 \pm 0.007
\pm 0.018 in the first and second case respectively. Using results of the
measurements, the electromagnetic running coupling constant \alpha in the
energy region \sqrt{s}=1040 -- 1380 MeV was obtained <1/\alpha> = 134.1\pm 0.5
\pm 1.2 and this is in agreement with theoretical expectation.


title: Intersection exponents for biased random walks on discrete cylinders

abstract:
  We prove existence of intersection exponents xi(k,lambda) for biased random
walks on d-dimensional half-infinite discrete cylinders, and show that, as
functions of lambda, these exponents are real analytic. As part of the
argument, we prove convergence to stationarity of a time-inhomogeneous Markov
chain on half-infinite random paths. Furthermore, we show this convergence
takes place at exponential rate, an estimate obtained via a coupling of
weighted half-infinite paths.


title: Recent $\nu$s from IceCube

abstract:
  IceCube is a 1 km$^3$ neutrino detector now being built at the South Pole.
Its 4800 optical modules will detect Cherenkov radiation from charged particles
produced in neutrino interactions. IceCube will search for neutrinos of
astrophysical origin, with energies from 100 GeV up to $10^{19}$ eV. It will be
able to separate $\nu_e$, $\nu_\mu$ and $\nu_\tau$. In addition to detecting
astrophysical neutrinos, IceCube will also search for neutrinos from WIMP
annihilation in the Sun and the Earth, look for low-energy (10 MeV) neutrinos
from supernovae, and search for a host of exotic signatures. With the
associated IceTop surface air shower array, it will study cosmic-ray air
showers.
  IceCube construction is now 50% complete. After presenting preliminary
results from the partial detector, I will discuss IceCube's future plans.


title: A note on Kaehler-Ricci flow

abstract:
  Let $g(t)$ with $t\in [0,T)$ be a complete solution to the Kaehler-Ricci
flow: $\frac{d}{dt}g_{i\bar j}=-R_{i\bar j}$ where $T$ may be $\infty$. In this
article, we show that the curvatures of $g(t)$ is uniformly bounded if the
solution $g(t)$ is uniformly equivalet. This result is stronger than the main
result in \v{S}e\v{s}um \cite{sesum} within the category of K\"ahler-Ricci
flow.


title: A geometric proof of the classification of complex vector cross product

abstract:
  In this article, we give a geometric proof of the classification of complex
vector cross product due to Lee-Leung.


title: Negativity of Perelman's Li-Yau-Hamilton type expression

abstract:
  Chau-Tam-Yu has proved the non-positivity of Perelman's new Li-Yau-Hamilton
type expression on noncompact manifolds. In this article, we further prove that
$v$ is negative if the Ricci flow is not end up with an Euclidean space.


title:
A Spin-Orbital Singlet and Quantum Critical Point on the Diamond
  Lattice: FeSc2S4

abstract:
  We present a theory of spin and orbital physics in the A-site spinel compound
FeSc2S4, which experimentally exhibits a broad "spin-orbital liquid" regime. A
spin-orbital Hamiltonian is derived from a combination of microscopic
consideration and symmetry analysis. We demonstrate a keen competition between
spin-orbit interactions, which favor formation of a local "Spin-Orbital
Singlet" (SOS), and exchange, which favors magnetic and orbital ordering.
Separating the SOS from the ordered state is a quantum critical point (QCP). We
argue that FeSc2S4 is close to this QCP on the SOS side. The full phase diagram
of the model includes a commensurate-incommensurate transition within the
ordered phase. A variety of comparison to and suggestion for experiments are
discussed.


title:
Some Estimates of Fundamental Solution on noncompact manifolds with
  time-dependent metrics

abstract:
  In this article, we obtain some further estimates of fundamental solutions
comparing to the result of Chau-Tam-Yu and give some applications of the
estimates on asymptotic behaviors of fundamental solutions.


title: Almost Sure Convergence of Extreme Order Statistics

abstract:
  Let $M_n^{(k)}$ denote the $k$th largest maximum of a sample
$(X_1,X_2,...,X_n)$ from parent $X$ with continuous distribution. Assume there
exist normalizing constants $a_n>0$, $b_n\in \mathbb{R}$ and a nondegenerate
distribution $G$ such that $a_n^{-1}(M_n^{(1)}-b_n)\stackrel{w}{\to}G$. Then
for fixed $k\in \mathbb{N}$, the almost sure convergence of
\[\frac{1}{D_N}\sum_{n=k}^Nd_n\mathbb{I}\{M_n^{(1)}\le a_nx_1+b_n,M_n^{(2)}\le
a_nx_2+b_n,...,M_n^{(k)}\le a_nx_k+b_n\}\] is derived if the positive weight
sequence $(d_n)$ with $D_N=\sum_{n=1}^Nd_n$ satisfies conditions provided by
H\"{o}rmann.


title: Entanglement renormalization, scale invariance, and quantum criticality

abstract:
  The use of entanglement renormalization in the presence of scale invariance
is investigated. We explain how to compute an accurate approximation of the
critical ground state of a lattice model, and how to evaluate local
observables, correlators and critical exponents. Our results unveil a precise
connection between the multi-scale entanglement renormalization ansatz (MERA)
and conformal field theory (CFT). Given a critical Hamiltonian on the lattice,
this connection can be exploited to extract most of the conformal data of the
CFT that describes the model in the continuum limit.


title: Cobordism categories of manifolds with corners

abstract:
  In this paper we study the topology of cobordism categories of manifolds with
corners. Specifically, if {Cob}_{d,<k>} is the category whose objets are a
fixed dimension d, with corners of codimension less than or equal to k, then we
identify the homotopy type of the classifying space B{Cob}_{d,<k>} as the zero
space of a homotopy colimit of certain diagram of Thom spectra. We also
identify the homotopy type of the corresponding cobordism category when extra
tangential structure is assumed on the manifolds. These results generalize the
results of Galatius, Madsen, Tillmann and Weiss, and the proofs are an
adaptation of the their methods. As an application we describe the homotopy
type of the category of open and closed strings with a background space X, as
well as its higher dimensional analogues. This generalizes work of
Baas-Cohen-Ramirez and Hanbury.


title: Chemical Abundances of the Leo II Dwarf Galaxy

abstract:
  We use previously-published moderate-resolution spectra in combination with
stellar atmosphere models to derive the first measured chemical abundance
ratios in the Leo II dSph galaxy. We find that for spectra with SNR > 24, we
are able to measure abundances from weak Ti, Fe and Mg lines located near the
calcium infrared triplet (CaT). We also quantify and discuss discrepancies
between the metallicities measured from Fe I lines and those estimated from the
CaT features. We find that while the most metal-poor ([Fe/H] <-2.0]) Leo II
stars have Ca and Ti abundance ratios similar to those of Galactic globular
clusters, the more metal-rich stars show a gradual decline of Ti, Mg and Ca
abundance ratio with increasing metallicity. Finding these trends in this
distant and apparently dynamically stable dSph galaxy supports the hypothesis
that the slow chemical enrichment histories of the dSph galaxies is universal,
independent of any interaction with the Milky Way. Combining our spectroscopic
abundances with published broadband photometry and updated isochrones, we are
able to approximate stellar ages for our bright RGB stars to a relative
precision of 2-3 Gyr. While the derived age-metallicity relationship of Leo II
hints at some amount of slow enrichment, the data are still statistically
consistent with no enrichment over the history of Leo II.


title: Detection of organic materials by spectrometric radiography method

abstract:
  In this paper we report a spectrometric approach to dual-energy digital
radiography that has been developed and applied to identify specific organic
substances and discern small differences in their effective atomic number. An
experimental setup has been designed, and a theoretical description proposed
based on the experimental results obtained. The proposed method is based on
application of special reference samples made of materials with different
effective atomic number and thickness, parameters known to affect X-ray
attenuation in the low-energy range. The results obtained can be used in the
development of a new generation of multi-energy customs or medical X-ray
scanners.


title: Ground-State Entropy of the Random Vertex-Cover Problem

abstract:
  Counting the number of ground states for a spin-glass or NP-complete
combinatorial optimization problem is even more difficult than the already hard
task of finding a single ground state. In this paper the entropy of minimum
vertex-covers of random graphs is estimated through a set of iterative
equations based on the cavity method of statistical mechanics. During the
iteration both the cavity entropy contributions and cavity magnetizations for
each vertex are updated. This approach overcomes the difficulty of iterative
divergence encountered in the zero temperature first-step
replica-symmetry-breaking (1RSB) spin-glass theory. It is still applicable when
the 1RSB mean-field theory is no longer stable. The method can be extended to
compute the entropies of ground-states and metastable minimal-energy states for
other random-graph spin-glass systems.


title: Note About Unstable M3-brane Action

abstract:
  We construct an action for unstable M3-brane in M-theory. We argue that in
order to find M3-brane action that upon direct dimensional reduction leads to
non-BPS D3-brane action in type IIA theory we have to presume that the
background possesses Killing isometry and that this isometry has to be gauged
on the world-volume of M3-brane. Then we construct singular tachyon kink on
world-volume of M3-brane and we show that the dynamics of resulting topological
defect is governed by an action that upon direct dimensional reduction leads to
D2-brane in type IIA theory and that is equivalent to standard M2-brane action
in flat background.


title: Differentiability of Banach Spaces via Constructible Sets

abstract:
  the main goal of this paper is to prove that any Banach space X, that every
dual ball in X** is weak* -separable, or every weak* -closed convex subset in
X** is weak* -separable, or every norm-closed convex set in X* is
constructible, admits an equivalent Frechet differentiable norm.


title:
Convexity of Chebyshev Sets Through Differentiability of Distance
  Function

abstract:
  In this paper, we study a part of approximation theory that presents the
conditions under which a \Ceby\sev set in a Banach space is convex. To do so,
we use Gateaux differentiability of the distance function.


title: Impact of slepton generation mixing on the search for sneutrinos

abstract:
  We perform a systematic study of sneutrino production and decays in the
Minimal Supersymmetric Standard Model (MSSM) with lepton flavour violation
(LFV). We study bosonic decays of sneutrinos as well as fermionic ones. We show
that the effect of slepton generation mixing on the sneutrino production and
decays can be quite large in a significant part of the MSSM parameter space
despite the very strong experimental limits on LFV processes. This could have
an important impact on the search for sneutrinos and the determination of the
MSSM parameters at LHC and future colliders, such as ILC, CLIC and muon
collider.


title: Expansive homoclinic classes

abstract:
  We prove that for $C^1$ generic diffeomorphisms, every expansive homoclinic
class is hyperbolic.


title:
One- and two-photon spectroscopy of a flux qubit coupled to a
  microscopic defect

abstract:
  We observed the dynamics of a superconducting flux qubit coupled to an
extrinsic quantum system (EQS). The presence of the EQS is revealed by an
anticrossing in the spectroscopy of the qubit. The excitation of a two-photon
transition to the third excited state of the qubit-EQS system allows us to
extract detailed information about the energy level structure and the coupling
of the EQS. We deduce that the EQS is a two-level system, with a transverse
coupling to the qubit. The transition frequency and the coupling of the EQS
changed during experiments, which supports the idea that the EQS is a two-level
system of microscopic origin.


title: On certain permutation groups and sums of two squares

abstract:
  We consider the question of existence of ramified covers over P_1 matching
certain prescribed ramification conditions. This problem has already been faced
in a number of papers, but we discuss alternative approaches for an existence
proof, involving elliptic curves and universal ramified covers with signature.
We also relate the geometric problem with finite permutation groups and with
the Fermat-Euler Theorem on the representation of a prime as a sum of two
squares.


title:
Enhancing extraordinary transmission of light through a metallic nano
  slit with a nano cavity antenna

abstract:
  The extraordinary transmission of light through a nano slit in a metal film
is enhanced by introducing a nano cavity antenna formed by a nearby metallic
nano-strip over the slit opening. For a fixed wavelength, the width of the
metallic nano-strip should be chosen to make the horizontal
metal-insulator-metal waveguide of finite length resonant as a Fabry-Perot
cavity. When such a cavity antenna is used to enhance the transmission through
a non-resonant nano slit, the slit should be opened at a position with maximal
magnetic field in the horizontal resonant cavity. It is shown that an optimized
cavity antenna can enhance greatly the transmission of light through a
non-resonant nano slit (by about 20 times) or a resonant nano slit (by 124%).
The transmission spectrum of the nano slit can also be tuned by adjusting the
width of the metallic nano-strip. Such a transmission enhancement with a nano
cavity antenna is studied for the first time and the physical mechanism is
explained.


title: Information inequalities and a dependent Central Limit Theorem

abstract:
  We adapt arguments concerning information-theoretic convergence in the
Central Limit Theorem to the case of dependent random variables under
Rosenblatt mixing conditions. The key is to work with random variables
perturbed by the addition of a normal random variable, giving us good control
of the joint density and the mixing coefficient. We strengthen results of
Takano and of Carlen and Soffer to provide entropy-theoretic, not weak
convergence.


title: On the Combinatorics of the Boros-Moll Polynomials

abstract:
  The Boros-Moll polynomials arise in the evaluation of a quartic integral. The
original double summation formula does not imply the fact that the coefficients
of these polynomials are positive. Boros and Moll proved the positivity by
using Ramanujan's Master Theorem to reduce the double sum to a single sum.
Based on the structure of reluctant functions introduced by Mullin and Rota
along with an extension of Foata's bijection between Meixner endofunctions and
bi-colored permutations, we find a combinatorial proof of the positivity. In
fact, from our combinatorial argument one sees that it is essentially the
binomial theorem that makes it possible to reduce the double sum to a single
sum.


title: Recent Results from Super-Kamiokande

abstract:
  The recent results on the oscillation analyses of solar neutrino and the
atmospheric neutrino measurements in Super-Kamiokande are presented. Recent
status of the detector is also reported.


title: On quantum semigroup actions on finite quantum spaces

abstract:
  We show that a continuous action of a quantum semigroup $\mathcal{S}$ on a
finite quantum space (finite dimensional $\mathrm{C}^*$-algebra) preserving a
faithful state comes from a continuous action of the quantum Bohr
compactification $\mathfrak{b}\mathcal{S}$ of $\mathcal{S}$. Using the
classification of continuous compact quantum group actions on $M_2$ we give a
complete description of all continuous quantum semigroup actions on this
quantum space preserving a faithful state.


title: Direct Imaging of Fine Structure in the Chromosphere of a Sunspot Umbra

abstract:
  High-resolution imaging observations from the Hinode spacecraft in the CaII H
line are employed to study the dynamics of the chromosphere above a sunspot. We
find that umbral flashes and other brightenings produced by the oscillation are
extremely rich in fine structure, even beyond the resolving limit of our
observations (0.22"). The umbra is tremendously dynamic, to the point that our
time cadence of 20 s does not suffice to resolve the fast lateral (probably
apparent) motion of the emission source. Some bright elements in our dataset
move with horizontal propagation speeds of 30 km/s. We have detected
filamentary structures inside the umbra (some of which have a horizontal
extension of ~1500 km) which, to our best knowledge, had not been reported
before. The power spectra of the intensity fluctuations reveals a few distinct
areas with different properties within the umbra that seem to correspond with
the umbral cores that form it. Inside each one of these areas the dominant
frequencies of the oscillation are coherent, but they vary considerably from
one core to another.


title:
Fermionic Corrections to the Heavy-Quark Pair Production in the
  Quark-Antiquark Channel

abstract:
  We describe the analytic calculation of the fermionic two-loop QCD
corrections to the heavy-quark pair production process in the quark-antiquark
channel.


title: Translated Poisson approximation for Markov chains

abstract:
  The paper is concerned with approximating the distribution of a sum W of n
integer valued random variables Y_i, whose distributions depend on the state of
an underlying Markov chain X. The approximation is in terms of a translated
Poisson distribution, with mean and variance chosen to be close to those of W,
and the error is measured with respect to the total variation norm. Error
bounds comparable to those found for normal approximation with respect to the
weaker Kolmogorov distance are established, provided that the distribution of
the sum of the Y_i's between the successive visits of X to a reference state is
aperiodic. Without this assumption, approximation in total variation cannot be
expected to be good.


title: Squeezing and entanglement in a Bose-Einstein condensate

abstract:
  Entanglement, a key feature of quantum mechanics, is a resource that allows
the improvement of precision measurements beyond the conventional bound
reachable by classical means. This is known as the standard quantum limit,
already defining the accuracy of the best available sensors for various
quantities such as time or position. Many of these sensors are interferometers
in which the standard quantum limit can be overcome by feeding their two input
ports with quantum-entangled states, in particular spin squeezed states. For
atomic interferometers, Bose-Einstein condensates of ultracold atoms are
considered good candidates to provide such states involving a large number of
particles. In this letter, we demonstrate their experimental realization by
splitting a condensate in a few parts using a lattice potential. Site resolved
detection of the atoms allows the measurement of the conjugated variables atom
number difference and relative phase. The observed fluctuations imply
entanglement between the particles, a resource that would allow a precision
gain of 3.8 dB over the standard quantum limit for interferometric
measurements.


title: On meromorphic extendibility

abstract:
  Let D be a bounded domain in the complex plane whose boundary bD consists of
finitely many pairwise disjoint real analytic simple closed curves. Let f be an
integrable function on bD. In the paper we show how to compute the candidates
for poles of a meromorphic extension of f through D and thus reduce the
question of meromorphic extendibility to the question of holomorphic
extendibility. Let A(D) be the algebra of all continuous functions on the
closure of D which are holomorphic on D. For continuous functions f on bD we
obtain a characterization of meromorphic extendibility in terms of the argument
principle: f extends meromorphically through D if and only if there is a
nonnegative integer N such that the winding number of Pf+Q along bD is bounded
below by -N for all P, Q in A(D) such that Pf+Q has no zero on bD. If this is
the case then the meromorphic extension of f has at most N poles in D, counting
multiplicity.


title:
Stochastic excitation of nonradial modes II. Are solar asymptotic
  gravity modes detectable?

abstract:
  Detection of solar gravity modes remains a major challenge to our
understanding of the innerparts of the Sun. Their frequencies would enable the
derivation of constraints on the core physical properties while their
amplitudes can put severe constraints on the properties of the inner convective
region. Our purpose is to determine accurate theoretical amplitudes of solar g
modes and estimate the SOHO observation duration for an unambiguous detection.
We investigate the stochastic excitation of modes by turbulent convection as
well as their damping. Input from a 3D global simulation of the solar
convective zone is used for the kinetic turbulent energy spectrum. Damping is
computed using a parametric description of the nonlocal time-dependent
convection-pulsation interaction. We then provide a theoretical estimation of
the intrinsic, as well as apparent, surface velocity. Asymptotic g-mode
velocity amplitudes are found to be orders of magnitude higher than previous
works. Using a 3D numerical simulation, from the ASH code, we attribute this to
the temporal-correlation between the modes and the turbulent eddies which is
found to follow a Lorentzian law rather than a Gaussian one as previously used.
We also find that damping rates of asymptotic gravity modes are dominated by
radiative losses, with a typical life-time of $3 \times 10^5$ years for the
$\ell=1$ mode at $\nu=60 \mu$Hz. The maximum velocity in the considered
frequency range (10-100 $\mu$Hz) is obtained for the $\ell=1$ mode at $\nu=60
\mu$Hz and for the $\ell=2$ at $\nu=100 \mu$Hz. Due to uncertainties in the
modeling, amplitudes at maximum i.e. for $\ell=1$ at 60 $\mu$Hz can range from
3 to 6 mm s$^{-1}$.


title:
On-Line Long-Exposure Phase Diversity: a Powerful Tool for Sensing
  Quasi-Static Aberrations of Extreme Adaptive Optics Imaging Systems

abstract:
  The phase diversity technique is a useful tool to measure and pre-compensate
for quasi-static aberrations, in particular non-common path aberrations, in an
adaptive optics corrected imaging system. In this paper, we propose and
validate by simulations an extension of the phase diversity technique that uses
long exposure adaptive optics corrected images for sensing quasi-static
aberrations during the scientific observation, in particular for high-contrast
imaging. The principle of the method is that, for a sufficiently long exposure
time, the residual turbulence is averaged into a convolutive component of the
image and that phase diversity estimates the sole static aberrations of
interest. The advantages of such a procedure, compared to the processing of
short-exposure image pairs, are that the separation between static aberrations
and turbulence-induced ones is performed by the long-exposure itself and not
numerically, that only one image pair must be processed, that the estimation
benefits from the high SNR of long-exposure images, and that only the static
aberrations of interest are to be estimated. Long-exposure phase diversity can
also be used as a phasing sensor for a segmented aperture telescope. Thus, it
may be particularly useful for future planet finder projects such as EPICS on
the European ELT.


title: Pushing towards the ET sensitivity using 'conventional' technology

abstract:
  Recently, the design study `Einstein gravitational wave Telescope' (ET) has
been funded within the European FP7 framework. The ambitious goal of this
project is to provide a conceptual design of a detector with a hundred times
better sensitivity than currently operating instruments. It is expected that
this will require the development and implementation of new technologies, which
go beyond the concepts employed for the first and second detector generations.
However, it is a very interesting and educational exercise to imagine a
Michelson interferometer in which conventional technologies have been pushed to
- or maybe beyond - their limits to reach the envisaged sensitivity for the
Einstein Telescope. In this document we present a first sketchy analysis of
what modifications and improvements are necessary to go, step-by-step, from
second generation gravitational wave detectors to the Einstein Telescope.


title: Brachistochrones With Loose Ends

abstract:
  The classical problem of the brachistochrone asks for the curve down which a
body sliding from rest and accelerated by gravity will slip (without friction)
from one point to another in least time. In undergraduate courses on classical
mechanics, the solution of this problem is the primary example of the power of
the variational calculus. Here we address the generalized brachistochrone
problem that asks for the fastest sliding curve between a point and a given
curve or between two given curves. The generalized problem can be solved by
considering variations with varying endpoints. We will contrast the formal
solution with a much simpler solution based on symmetry and kinematic
reasoning. Our exposition should encourage teachers to include variational
problems with free boundary conditions in their courses and students to try
simple, intuitive solutions first.


title:
Study of the nucleon spin-dependent structure function $g_1$. A
  comparison with recent HERMES and COMPASS data

abstract:
  Predictions for the spin dependent structure function $g_1$ of the nucleon
are presented. We use an unified approach incorporating the LO DGLAP evolution
and the resummation of double logarithmic terms $ln^2(x)$. We show, that the
singular input parametrisation as $x\to 0$ can be a substitute of the $ln^2(x)$
resummation. An impact of the `more running' coupling is discussed. We
determine the contribution to the Bjorken sum rule solving the evolution
equation for the truncated moment of $g_1^{NS}$. A comparison with the
re-analysed HERMES and COMPASS data is given.


title:
Numerical simulation of stochastic motion of vortex loops under action
  of random force. Evidence of the thermodynamic equilibrium

abstract:
  Numerical simulation of stochastic dynamics of vortex filaments under action
of random (Langevin) force is fulfilled. Calculations are performed on base of
the full Biot--Savart law for different intensities of the Langevin force. A
new algorithm, which is based on consideration of crossing lines, is used for
vortex reconnection procedure. After some transient period the vortex tangle
develops into the stationary state characterizing by the developed fluctuations
of various physical quantities, such as total length, energy etc. We tested
this state to learn whether or not it the thermodynamic equilibrium is reached.
With the use of a special treatment, so called method of weighted histograms,
we process the distribution energy of the vortex system. The results obtained
demonstrate that the thermodynamical equilibrium state with the temperature
obtained from the fluctuation dissipation theorem is really reached.
PACS-numbers: 67.40.Vs 98.80.Cq 7.37.+q


title:
Dilution effects in Ho$_{2-x}$Y$_x$Sn$_2$O$_7$: from the Spin Ice to the
  single-ion magnet

abstract:
  A study of the modifications of the magnetic properties of
Ho$_{2-x}$Y$_x$Sn$_2$O$_7$ upon varying the concentration of diamagnetic
Y$^{3+}$ ions is presented. Magnetization and specific heat measurements show
that the Spin Ice ground-state is only weakly affected by doping for $x\leq
0.3$, even if non-negligible changes in the crystal field at Ho$^{3+}$ occur.
In this low doping range $\mu$SR relaxation measurements evidence a
modification in the low-temperature dynamics with respect to the one observed
in the pure Spin Ice. For $x\to 2$, or at high temperature, the dynamics
involve fluctuations among Ho$^{3+}$ crystal field levels which give rise to a
characteristic peak in $^{119}$Sn nuclear spin-lattice relaxation rate. In this
doping limit also the changes in Ho$^{3+}$ magnetic moment suggest a variation
of the crystal field parameters.


title:
Rare decays of $\Lambda_b \to \Lambda \gamma$ and $\Lambda_b \to \Lambda
  l^{+} l^{-}$ in universal extra dimension model

abstract:
  The exclusive weak decay of $\Lambda_b \to \Lambda \gamma$ and $\Lambda_b \to
\Lambda l^{+} l^{-}$ are investigated in the Applequist-Cheng-Dobrescu model,
which is an extension of the standard model in presence of universal extra
dimensions. Employing the transition form factors obtained in the light-cone
sum rues, we analyze how the invariant mass distribution, forward-backward
asymmetry and polarization asymmetry of $\Lambda$ baryon of these decay modes
can be used to constrain the only one additional free parameter with respect to
the standard model, namely, the radius $R$ of the extra dimension. Our results
indicate that the Kaluza-Klein modes can lead to approximately 25% suppression
of the branching ratio of $\Lambda_b \to \Lambda \gamma$, however, their
contributions can bring about 10% enhancement to the decay rate of $\Lambda_b
\to \Lambda l^{+} l^{-}$. It is shown that the zero-position of
forward-backward asymmetry of $\Lambda_b \to \Lambda \mu^{+} \mu^{-}$ is
sensitive to the compactification parameter $R$ in this scenario, while the
measurement of polarizations of $\Lambda$ baryon in the $\Lambda_b$ decays is
not suitable to provide some valuable information for the universal extra
dimension model.


title: Inverse Spin Hall Effect Driven by Spin Motive Force

abstract:
  The spin Hall effect is a phenomenon that an electric field induces a spin
Hall current. In this Letter, we examine the inverse effect that, in a
ferromagnetic conductor, a charge Hall current is induced by a spin motive
force, or a spin-dependent effective ` electric' field ${\bm E}_{\rm s}$,
arising from the time variation of magnetization texture. By considering
skew-scattering and side-jump processes due to spin-orbit interaction at
impurities, we obtain the Hall current density as $\sigma_{\rm SH} {\bm
n}\times{\bm E}_{\rm s}$, where ${\bm n}$ is the local spin direction and
$\sigma_{\rm SH}$ is the spin Hall conductivity. The Hall angle due to the spin
motive force is enhanced by a factor of $P^{2}$ compared to the conventional
anomalous Hall effect due to the ordinary electric field, where $P$ is the spin
polarization of the current. The Hall voltage is estimated for a field-driven
domain wall oscillation in a ferromagnetic nanowire.


title:
General properties of the boundary renormalization group flow for
  supersymmetric systems in 1+1 dimensions

abstract:
  We consider the general supersymmetric one-dimensional quantum system with
boundary, critical in the bulk but not at the boundary. The renormalization
group flow on the space of boundary conditions is generated by the boundary
beta functions \beta^{a}(\lambda) for the boundary coupling constants
\lambda^{a}. We prove a gradient formula \partial\ln z/\partial\lambda^{a}
=-g_{ab}^{S}\beta^{b} where z(\lambda) is the boundary partition function at
given temperature T=1/\beta, and g_{ab}^{S}(\lambda) is a certain
positive-definite metric on the space of supersymmetric boundary conditions.
The proof depends on canonical ultraviolet behavior at the boundary. Any system
whose short distance behavior is governed by a fixed point satisfies this
requirement. The gradient formula implies that the boundary energy,
-\partial\ln z/\partial\beta = -T\beta^{a}\partial_{a}\ln z, is nonnegative.
Equivalently, the quantity \ln z(\lambda) decreases under the renormalization
group flow.


title:
SMEI observations of previously unseen pulsation frequencies in gamma
  Doradus

abstract:
  Aims: As g-mode pulsators, gamma-Doradus-class stars may naively be expected
to show a large number of modes. Taking advantage of the long photometric
time-series generated by the Solar Mass Ejection Imager (SMEI) instrument, we
have studied the star gamma Doradus to determine whether any other modes than
the three already known are present at observable amplitude. Methods:
High-precision photometric data from SMEI taken between April 2003 and March
2006 were subjected to periodogram analysis with the PERIOD04 package. Results:
We confidently determine three additional frequencies at 1.39, 1.87, and 2.743
cycles per day. These are above and beyond the known frequencies of 1.320,
1.364, and 1.47 cycles per day. Conclusions: Two of the new frequencies, at
1.39 and 1.87 cycles per day, are speculated to be additional modes of
oscillation, with the third frequency at 2.743 cycles per day a possible
combination frequency.


title: On the condensed matter scheme for emergent gravity and interferometry

abstract:
  An increasingly popular approach to quantum gravity rests on the idea that
gravity (and maybe electromagnetism and the other gauge fields) might be an
'emergent phenomenon', in the sense of representing a collective behaviour
resulting from a very different microscopic physics. A prominent example of
this approach is the condensed matter scheme for quantum gravity, which
considers the possibility that gravity emerges as an effective low-energy
phenomenon from the quantum vacuum in a way similar to the emergence of
collective excitations in condensed matter systems. This condensed matter view
of the quantum vacuum clearly hints that, while the term 'ether' has been
discredited for about a century, quantum gravity holds many (if not all) of the
characteristics that have led people in the past to label various hypothetical
substances with the term 'ether'. Since the last burst of enthusiasm for an
ether, at the end of the 19th century, was brought to the grave in part by the
performance of a series of important experiments in interferometry, the
suggestion then naturally arises that maybe interferometry could also play a
role in the current discussion on quantum gravity. We will highlight some
aspects of this suggestion in the context of the condensed matter scheme for
emergent gravity.


title: Um Erro Com Um Seculo

abstract:
  The "rigid bodies" must be in Relativity the "deformable bodies" where the
longitudinal waves propagate with the maximun speed $c$. In 1909, Born studied
the "relativistic underformable body" but made the mistake of calling it
"rigid". The "rigid body" one can find in all Relativity books is, in fact,
Born's "undeformable body" of 1909. This error was at the origin of a lot of
difficulties and paradoxes not yet clarifed in any relativity book. The
"relativistic elastic laws for rigid bodies in one dimension" were discovered
by Mc Crea, in 1952, and by A.Brotas, in 1968. The generalization of these laws
for 2 and 3 dimensions resolve all those paradoxes. We propose the introdution
of these laws in the elementary courses of Relativity.


title:
Coherent bremsstrahlung in periodically deformed crystals with a complex
  base

abstract:
  In the present paper we investigate coherent bremsstrahlung of high energy
electrons moving in a periodically deformed single crystal with a complex base.
The formula for corresponding differential cross-section is derived for an
arbitrary deformation field. The conditions are discussed under which the
influence of the deformation is important. The case is considered in detail
when the electron enters into the crystal at small angles with respect to a
crystallographic axis. It is shown that in dependence of the parameters, the
presence of the deformation can either enhance or reduce the bremsstrahlung
cross-section.


title:
Influence of antisymmetric exchange interaction on quantum tunneling of
  magnetization in a dimeric molecular magnet Mn6

abstract:
  We present magnetization measurements on the single molecule magnet Mn6,
revealing various tunnel transitions inconsistent with a giant-spin
description. We propose a dimeric model of the molecule with two coupled spins
S=6, which involves crystal-field anisotropy, symmetric Heisenberg exchange
interaction, and antisymmetric Dzyaloshinskii-Moriya exchange interaction. We
show that this simplified model of the molecule explains the experimentally
observed tunnel transitions and that the antisymmetric exchange interaction
between the spins gives rise to tunneling processes between spin states
belonging to different spin multiplets.


title: The Constrained E$_6$SSM

abstract:
  We present a self--consistent $E_6$ inspired supersymmetric model with an
extra $U(1)_{N}$ gauge symmetry under which right-handed neutrinos have zero
charge. We explore the particle spectrum within the constrained version of this
exceptional supersymmetric standard model (E$_6$SSM) and discuss its possible
collider signatures.


title: What do dynamical cluster masses really tell us about dynamics?

abstract:
  The diagnostic age versus mass-to-light ratio diagram is often used in
attempts to constrain the shape of the stellar initial mass function, and the
stability and the potential longevity of extragalactic young to
intermediate-age massive star clusters. Here, we explore the pitfalls
associated with this approach and its potential for use with Galactic open
clusters. We conclude that for an open cluster to survive for any significant
fraction of a Hubble time (in the absence of substantial external
perturbations), it is a necessary but not a sufficient condition to be located
close to the predicted photometric evolutionary sequences for "normal" simple
stellar populations.


title:
Gravimagnetic nucleon form-factors in the impact parameter
  representation

abstract:
  In the framework of the new t-dependence of the General Parton Distributions
(GPDs), which reproduce the electromagnetic form factors of the proton and
neutron at small and large momentum transfer, the gravitational form factors of
the nucleons and a separate contribution of the quarks to them are obtained.


title:
Analysis of the Schroedinger Functional with Chirally Rotated Boundary
  Conditions

abstract:
  The Schroedinger functional provides a valuable tool to perform
non-perturbative renormalization on the lattice, in particular in a mass
independent scheme. We study two different types of chirally rotated
Schroedinger functional boundary conditions which have been recently proposed
to retain the bulk automatic O(a) improvement of massless Wilson fermions in
finite volume. We investigate the spectral properties and the quark propagators
which derive from these two proposals in the continuum at tree-level of
perturbation theory.


title:
Hadronic observables from Au+Au collisions at s(NN)**(1/2)=200 GeV and
  Pb+Pb collisions at s(NN)**(1/2)=5.5 TeV from a simple kinematic model

abstract:
  A simple kinematic model based on superposition of p+p collisions,
relativistic geometry and final-state hadronic rescattering is used to
calculate various hadronic observables in s(NN)**(1/2) = 200 GeV Au+Au
collisions and s(NN)**(1/2) = 5.5 TeV Pb+Pb collisions. The model calculations
are compared with experimental results from several s(NN)**(1/2) = 200 GeV
Au+Au collision studies. If a short hadronization time is assumed in the model,
it is found that this model describes the trends of the observables from these
experiments surprisingly well considering the model's simplicity. This also
gives more credibility to the model predictions presented for s(NN)**(1/2) =
5.5 TeV Pb+Pb collisions.


title: Spherical Deformation for One-dimensional Quantum Systems

abstract:
  System-size dependence of the ground-state energy E^N is investigated for
N-site one-dimensional (1D) quantum systems with open boundary condition, where
the interaction strength decreases towards the both ends of the system. For the
spinless Fermions on the 1D lattice we have considered, it is shown that the
finite-size correction to the energy per site, which is defined as E^N / N -
\lim_{N \to \infty} E^N / N, is of the order of 1 / N^2 when the reduction
factor of the interaction is expressed by a sinusoidal function. We discuss the
origin of this fast convergence from the view point of the spherical geometry.


title: Atomic Frequency standards Based on Pulsed Coherent Light Storage

abstract:
  We propose a new scheme of microwave frequency standards based on pulsed
coherent optical information storage. Unlike the usual frequency reference
where the Ramsey fringe is printed on the population of a certain state, we
print the Ramsey fringe on the coherence. Then the coherence is detected in the
form of a retrieval light. The central line of the Ramsey fringe can be used as
a frequency reference in an absorption-cell-based atomic frequency standard.
This scheme is free of light shifts as the interrogating process is separated
from the optical pumping processes, and the cavity pulling effect is negligible
due to the low Q requirement. Encoding the Ramsey interference into the
retrieval light pulse has the merit of high signal to noise ratio and the
estimated frequency stability of shot noise limit is about $2\times10^{-14}$ in
1 second, this scheme is promising for building small, compact and stable
atomic frequency standards.