title:
Higher order terms in the geometric resonance of open orbits in
  unidirectional lateral superlattices

abstract:
  The geometric resonance of open orbits in unidirectional lateral
superlattices has been examined with high magnetic-field resolution.
Magnetoresistance oscillations periodic in 1/B, analogous to the well-known
commensurability oscillations but orders of magnitude smaller both in magnitude
and in the magnetic-field scale, have been observed superposed on the low-field
positive magnetoresistance. The periodicity in 1/B can be interpreted in terms
of higher order resonances.


title: Probing the thermal atoms of a Bose gas through Raman transition

abstract:
  We explore the many body physics of a Bose condensed atom gas at finite
temperature through the Raman transition between two hyperfine levels. Unlike
the Bragg scattering where the phonon-like nature of the collective excitations
has been observed, a different branch of thermal atom excitation is found
theoretically in the Raman scattering. This excitation is predicted in the
generalized random phase approximation (GRPA) and has a gapped and parabolic
dispersion relation. The gap energy results from the exchange interaction and
is released during the Raman transition. The scattering rate is determined
versus the transition frequency $\omega$ and the transferred momentum $\vc{q}$
and shows the corresponding resonance around this gap. Nevertheless, the Raman
scattering process is attenuated by the superfluid part of the gas. The
macroscopic wave function of the condensate deforms its shape in order to
screen locally the external potential displayed by the Raman light beams. This
screening is total for a condensed atom transition in order to prevent the
condensate from incoherent scattering. The experimental observation of this
result would explain some of the reasons why a superfluid condensate moves
coherently without any friction with its surrounding.


title: Effects of rotation on the evolution of primordial stars

abstract:
  (Abridged) Rotation has been shown to play a determinant role at very low
metallicity, bringing heavy mass loss where almost none was expected. Is this
still true when the metallicity strictly equals zero? The aim of our study is
to get an answer to this question, and to determine how rotation changes the
evolution and the chemical signature of the primordial stars. We have
calculated 14 differentially-rotating and non-rotating stellar models at zero
metallicity, with masses between 9 and 200 Msol. The evolution has been
followed up to the pre-supernova stage. We find that Z=0 models rotate with an
internal profile Omega(r) close to local angular momentum conservation, because
of a very weak core-envelope coupling. Rotational mixing drives a H-shell boost
due to a sudden onset of CNO cycle in the shell. This boost leads to a high 14N
production. Generally, the rotating models produce much more metals than their
non-rotating counterparts. The mass loss is very low, even for the models that
reach the critical velocity during the main sequence. Due to the low mass loss
and the weak coupling, the core retains a high angular momentum at the end of
the evolution. The high rotation rate at death probably leads to a much
stronger explosion than previously expected, changing the fate of the models.
The inclusion of our yields in a chemical evolution model of the Galactic halo
predicts log values of N/O, C/O and 12C/13C ratios of -2.2, -0.95 and 50
respectively at log O/H +12 = 4.2.


title: Equisingularity and The Euler Characteristic of a Milnor Fibre

abstract:
  We study the Euler characteristic of the Milnor fibre of a hypersurface
singularity. This invariant is given in terms of the Euler characteristic of a
fibre in between the original singularity and its Milnor fibre and in terms of
the Euler characteristics associated to strata of the in-between fibre.
  From this we can deduce a result of Massey and Siersma regarding
singularities with a one-dimensional critical locus. The result is also applied
to the study of equisingularity. The famous Brian\c{c}on-Speder-Teissier result
states that a family of isolated hypersurface singularities is equisingular if
and only if its $\mu ^*$-sequence is constant. We show that if a similar
sequence for a family of corank 1 complex analytic mappings from n-space to
(n+1)-space is constant, then the image of the family of mappings is
equisingular. For families of corank 1 maps from 3-space to 4-space we show
that the converse is true also.


title: Iteratively re-weighted least squares minimization for sparse recovery

abstract:
  We analyze an Iteratively Re-weighted Least Squares (IRLS) algorithm for
promoting l1-minimization in sparse and compressible vector recovery. We prove
its convergence and we estimate its local rate. We show how the algorithm can
be modified in order to promote lt-minimization for t<1, and how this
modification produces superlinear rates of convergence.


title:
Feasibility study of the eta-prime -> pi+pi-pi0 decay using WASA-at-COSY
  apparatus

abstract:
  One of the objectives of the vast physics programme of the recently
comissioned WASA-at-COSY facility is the study of fundamental symmetries via
the measurements of the eta and eta-prime mesons decays. Especially interesting
are isospin violating hadronic precesses of these mesons into 3pi systems
driven by the term of QCD Lagrangian which depends on the mass difference of
the u and d quarks. When an eta or an eta-prime meson is created in the
hadronic reaction signals from such decays may be significantly obscured by the
prompt production of pi mesons. In this thesis we present the estimation of the
upper limit of the background due to prompt pion production for the eta-prime
->3pi0 and eta-prime->pi+pi-pi decays. Using the data from proton-proton
collisions measured by the COSY-11 group we have extracted differential cross
sections for the multimeson production with the invariant mass corresponding to
the mass of the eta-prime meson. Based on these results and on parametrizations
of the total cross sections for the eta-prime meson as well as parametrization
of the upper limit for the prompt pi+pi-pi0 production in the collisions of
protons we discuss in details the feasibility of a measurement of the eta-prime
meson decay into 3pi channels with the WASA-at-COSY facility. Based on the
chiral unitary approach the value of the branching ratio
BR(eta-prime->pi+pi-pi0) was recently predicted to be about 1%. We show that
the WASA-at-COSY has a potential to verify this result empirically.


title: Three-dimensional compact manifolds and the Poincare conjecture

abstract:
  The aim of the work is to prove the following main theorem. Theorem. Let M3
be a three-dimensional, connected, simple-connected, closed, compact, smooth
manifold. Tnen the manifold M3 is diffeomorphic to the three-dimensional
sphere.


title:
Simple Explanation of Fermi Arcs in Cuprate Pseudogaps: a Motional
  Narrowing Phenomenon

abstract:
  ARPES measurements on underdoped cuprates above the superconducting
transition temperature exhibit the unique phenomenon of Fermi arcs, gapless
arcs of Fermi surface around the nodal points of the superconducting gap, which
terminate before reaching the antinodes. We show that this phenomenon is easily
explained (including its temperature dependence and observed hole-electron
asymmetry) as the natural consequence of a time-fluctuating d-wave gap.


title: XMM-Newton X-ray spectra of the SNR 0509-67.5: data and models

abstract:
  We report on X-ray observations of the supernova remnant 0509-67.5 in the
Large Magellanic Cloud with XMM-Newton X-ray observatory. We use the imaging
spectroscopy (EPIC) and Reflective Grating Spectrometer (RGS) data to
investigate properties of the remnant and its environment. The X-ray spectra
were analyzed with SPEX software package. In addition to this we performed a
numerical hydrodynamic simulation of the remnant. The EPIC data show prominent
Fe K line emission, but the deduced overall amount of iron in the shocked
ejecta is low. The data also show that the remnant has an asymmetric ejecta
structure: the bright southwest region of the remnant shows an overabundance of
metals. The analysis of the RGS spectrum shows that the remnant has a high
lines velocity broadening of ~5000 km/s. We found a hydrodynamical model for
the remnant with basic hydrodynamical and spectral parameters similar to the
observed ones. The data analysis show that the reverse shock just recently
reached iron layers of the ejecta. The brightness enhancement in the southwest
region could be a sign of an asymmetric explosion or it could be the result of
a density enhancement of the interstellar medium. We constructed numerical
models which are in good agreement with the observations, with circumstellar
density of 3e-25 g/cm^3, age of ~400 years, velocities of ~5000 km/s and an
electron to ion temperature ratio of 0.01.


title:
On the Consistence Conditions to Braneworlds Sum Rules in Scalar-Tensor
  Gravity for Arbitrary Dimensions

abstract:
  We derive an one-parameter family of consistence conditions to braneworlds in
the Brans-Dicke gravity. The sum rules are constructed in a completely general
frame and they reproduce the conditions already obtained in General Relativity
theory just by using a right limit of the Brans-Dicke parameter.


title:
Transport properties and Kondo correlations in nanostructures: the
  time-dependent DMRG method applied to quantum dots coupled to Wilson chains

abstract:
  We apply the adaptive time-dependent Density Matrix Renormalization Group
method (tDMRG) to the study of transport properties of quantum-dot systems
connected to metallic leads. Finite-size effects make the usual tDMRG
description of the Kondo regime a numerically demanding task. We show that such
effects can be attenuated by describing the leads by "Wilson chains", in which
the hopping matrix elements decay exponentially away from the impurity ($t_n
\propto \Lambda^{-n/2}$). For a given system size and in the linear response
regime, results for $\Lambda > 1$ show several improvements over the undamped,
$\Lambda=1$ case: perfect conductance is obtained deeper in the strongly
interacting regime and current plateaus remain well defined for longer time
scales. Similar improvements were obtained in the finite-bias regime up to bias
voltages of the order of the Kondo temperature. These results show that, with
the proposed modification, the tDMRG characterization of Kondo correlations in
the transport properties can be substantially improved, while it turns out to
be sufficient to work with much smaller system sizes. We discuss the numerical
cost of this approach with respect to the necessary system sizes and the
entanglement growth during the time-evolution.


title:
Direct observation of Space Charge Dynamics by picosecond Low Energy
  Electron Scattering

abstract:
  The electric field governing the dynamics of space charge produced by high
intensity femtosecond laser pulses focused on a copper surface is investigated
by time-resolved low-energy-electron-scattering. The pump-probe experiment has
a measured temporal resolution of better than 35 ps at 55 eV probe electron
energy. The probe electron acceleration due to space charge is reproduced
within a 3-dimensional non-relativistic model, which determines an effective
number of electrons in the space charge electron cloud and its initial
diameter. Comparison of the simulations with the experiments indicates a
Coulomb explosion, which is consistent with transients in the order of 1 ns,
the terminal kinetic energy of the cloud and the thermoemission currents
predicted by the Richardson-Dushman formula.


title: Natural Metric for Quantum Information Theory

abstract:
  We study in detail a very natural metric for quantum states. This new
proposal has two basic ingredients: entropy and purification. The metric for
two mixed states is defined as the square root of the entropy of the average of
representative purifications of those states. Some basic properties are
analyzed and its relation with other distances is investigated. As an
illustrative application, the proposed metric is evaluated for 1-qubit mixed
states.


title: Deformation Theory of Courant Algebroids via the Rothstein Algebra

abstract:
  In this paper we define Courant algebroids in a purely algebraic way and
study their deformation theory by using two different but equivalent graded
Poisson algebras of degree -2. First steps towards a quantization of Courant
algebroids are proposed by employing a Fedosov like deformation quantization.


title:
Electric Field Control of the LaAlO$_{3}$/SrTiO$_{3}$ Interface Ground
  State

abstract:
  Interfaces between complex oxides are emerging as one of the most interesting
playgrounds in condensed matter physics. In this special setting, in which
translational symmetry is artificially broken, a variety of novel electronic
phases can be promoted. Theoretical studies predict complex phase diagrams and
suggest the key role of the carrier density in determining the systems ground
states. A particularly fascinating system is the interface between the
insulators LaAlO$_{3}$ and SrTiO$_{3}$, which displays conductivity with high
mobility. Recently two possible ground states have been experimentally
identified: a magnetic state and a two dimensional (2D) superconducting
condensate. In this Letter we use the electric field effect to explore the
phase diagram of the system. The electrostatic tuning of the carrier density
allows an on/off switching of superconductivity and drives a quantum phase
transition (QPT) between a 2D superconducting state and an insulating state
(2D-QSI). Analyses of the magnetotransport properties in the insulating state
are consistent with weak localisation and do not provide evidence for
magnetism. The electric field control of superconductivity demonstrated here
opens the way to the development of novel mesoscopic superconducting circuits


title: Degenerate and critical Bloch branes

abstract:
  In the last few years a number of works reported the appearance of thick
branes with internal structure, induced by the parameter which controls the
interaction between two scalar fields coupled to gravity in (4,1) dimensions in
warped space-time with one extra dimension. Here we show that one can implement
the control over the brane thickness without needing to change the potential
parameter. On the contrary, this is going to be done by means of the variation
of a parameter associated to the domain wall degeneracy. We also report the
existence of novel and qualitatively different solutions for a critical value
of the degeneracy parameter, which could be called critical Bloch branes.


title: Competitions of magnetism and superconductivity in FeAs-based materials

abstract:
  Using the numerical unrestricted Hartree-Fock approach, we study the ground
state of a two-orbital model describing newly discovered FeAs-based
superconductors. We observe the competition of a $(0, \pi)$ mode spin-density
wave and the superconductivity as the doping concentration changes. There might
be a small region in the electron-doping side where the magnetism and
superconductivity coexist. The superconducting pairing is found to be spin
singlet, orbital even, and mixed s$_{xy}$ + d$_{x^{2}-y^{2}}$ wave (even
parity).


title: On Locally Conformally Flat Gradient Shrinking Ricci Solitons

abstract:
  In this paper, we first apply an integral identity on Ricci solitons to prove
that closed locally conformally flat gradient Ricci solitons are of constant
sectional curvature. We then generalize this integral identity to complete
noncompact gradient shrinking Ricci solitons, under the conditions that the
Ricci curvature is bounded from below and the Riemannian curvature tensor has
at most exponential growth. As a consequence of this identity, we classify
complete locally conformally flat gradient shrinking Ricci solitons with Ricci
curvature bounded from below.


title:
Search for events with an isolated lepton and missing transverse
  momentum and a measurement of W production at HERA

abstract:
  A search for events with an isolated high-energy lepton and large missing
transverse momentum has been performed with the ZEUS detector at HERA using a
total integrated luminosity of 504 $\mathrm{pb}^{-1}$. The results agree well
with Standard Model predictions. The cross section for production of single $W$
bosons in electron-proton collisions with unpolarised electrons is measured to
be $0.89^{+0.25}_{-0.22}$ (stat.) $\pm{0.10}$ (syst.) pb.


title: The Hubble diagram of high redshift objects, QSOs and AGNs

abstract:
  According to the Hubble law, high redshift objects such as Quasar (QSOs),
X-ray Active Galactic Nuclei (AGN) together with the Gamma Ray Burst (GRBs) are
the fastest and farthest objects. These characteristics provides strong
motivations for they to be used to constrain the cosmological parameters,
without the limitations found in the Ia supernovae study and which is
restricted to redshift of up to 1.7. However, the variability and behavior in
the QSOs and AGNs spectra tell us that they have very complex structures and
the standard candle framework can not be applied. So far the available data of
QSOs and AGNs have shown some anomalies observed in their brightness and
metallicities, difficult to understand, under an orthodox point of view. Here,
we show that their Hubble diagram flattens for $z\geq 3 $. The result need
further confirmation, because the statistics of high redshift extragalactic
objects is still poor. Details and some implications of these results are
reported in this work.


title: Higgs sector of the next-to-minimal renormalizable SUSY SO(10)

abstract:
  We study the Higgs potential of the next-to-minimal renormalizable SUSY
SO(10) GUT with 120 Higgs representation on top of the "standard" minimal model
Higgs sector spanning over 10, 126bar+126 and 210. All the GUT-scale Higgs
sector mass matrices for the 592 Higgs states of the model are written down in
detail with all the conventions fully specified. The consistency of the results
is checked by the decoupling of 120 and independently by the analysis of the
relevant Goldstone modes. The matching of the Yukawa sector sum-rules driving
the matter fermion masses and mixing at the level of the effective theory is
described thoroughly.


title: Orthogonal systems in vector spaces over finite fields

abstract:
  We prove that if a subset of the d-dimensional vector space over a finite
field is large enough, then it contains many k-tuples of mutually orthogonal
vectors.


title: Higher Tetraquark Particles

abstract:
  There are strong arguments favoring a four-quark interpretation of sub-GeV
light scalar mesons and the diquark-antidiquark body-plan of the tetraquark
seems to provide the most convincing picture. The building diquarks of these
particles are assumed to be spin zero objects. In this paper we explore the
possibility that radially excited aggregations of spin zero or spin one
diquarks might exist and discuss the possibility of the Y(2175) state observed
by BaBar and confirmed by BES being one such state.


title: Beam asymmetry in near threshold omega photoproduction off the proton

abstract:
  The photoproduction of omega mesons off protons has been studied at the Bonn
ELSA accelerator from threshold to E_gamma = 1700 MeV. Linearly polarized beams
were produced via coherent bremsstrahlung. Large photon asymmtries in excess of
50% were obtained, whereas the pion asymmetries from omega \to pi^0 gamma are
close to zero. The asymmetries do characteristically depend on Theta_{cm}
rather than |t| and indicate s-channel resonance formation on top of t-channel
exchange processes.


title:
Nonstandard linear recurring sequence subgroups in finite fields and
  automorphisms of cyclic codes

abstract:
  Let $q=p^r$ be a prime power, and let $f(x)=x^m-\gs_{m-1}x^{m-1}-
>...-\gs_1x-\gs_0$ be an irreducible polynomial over the finite field $\GF(q)$
of size $q$. A zero $\xi$ of $f$ is called {\em nonstandard (of degree $m$)
over $\GF(q)$} if the recurrence relation $u_m=\gs_{m-1}u_{m-1} + ... +
\gs_1u_1+\gs_0u_0$ with characteristic polynomial $f$ can generate the powers
of $\xi$ in a nontrivial way, that is, with $u_0=1$ and $f(u_1)\neq 0$. In
2003, Brison and Nogueira asked for a characterisation of all nonstandard cases
in the case $m=2$, and solved this problem for $q$ a prime, and later for
$q=p^r$ with $r\leq4$.
  In this paper, we first show that classifying nonstandard finite field
elements is equivalent to classifying those cyclic codes over $\GF(q)$
generated by a single zero that posses extra permutation automorphisms.
  Apart from two sporadic examples of degree 11 over $\GF(2)$ and of degree 5
over $\GF(3)$, related to the Golay codes, there exist two classes of examples
of nonstandard finite field elements. One of these classes (type I) involves
irreducible polynomials $f$ of the form $f(x)=x^m-f_0$, and is well-understood.
The other class (type II) can be obtained from a primitive element in some
subfield by a process that we call extension and lifting. We will use the known
classification of the subgroups of $\PGL(2,q)$ in combination with a recent
result by Brison and Nogueira to show that a nonstandard element of degree two
over $\GF(q)$ necessarily is of type I or type II, thus solving completely the
classification problem for the case $m=2$.


title: Zero-size objects in Riemann-Cartan spacetime

abstract:
  We use the conservation law of the stress-energy and spin tensors to study
the motion of massive zero-size objects in Riemann-Cartan geometry. The
resultant world line equations turn out to exhibit a novel spin-curvature
coupling. In particular, the spin of the Dirac particle does not couple to the
background curvature. This is a consequence of its truly zero size which
consistently rules out the orbital degrees of freedom. As a test of
consistency, the wave packet solution of the free Dirac equation is considered.
It is shown that the wave packet spin and orbital angular momentum disappear
simultaneously in the zero-size limit.


title: Topological open strings on orbifolds

abstract:
  We use the remodeling approach to the B-model topological string in terms of
recursion relations to study open string amplitudes at orbifold points. To this
end, we clarify modular properties of the open amplitudes and rewrite them in a
form that makes their transformation properties under the modular group
manifest. We exemplify this procedure for the C^3/Z_3 orbifold point of local
P^2, where we present results for topological string amplitudes for genus zero
and up to three holes, and for the one-holed torus. These amplitudes can be
understood as generating functions for either open orbifold Gromov-Witten
invariants of C^3/Z_3, or correlation functions in the orbifold CFT involving
insertions of both bulk and boundary operators.


title: Steady compressible Oseen flow with slip boundary conditions

abstract:
  We prove the existence of solution in a class H^2(\Omega) x H^1(\Omega) to
steady compressible Oseen system with slip boundary conditions in a two
dimensional, convex domain with the boundary of class H^{5/2}. The method is to
regularize a weak solution obtained via the Galerkin method. The problem of
regularization is reduced to a problem of solvability of a certain transport
equation by application of the Helmholtz decomposition. The method works under
additional assumption on the geometry of the boundary.


title: Semisimple Hopf algebras and their depth two Hopf subalgebras

abstract:
  We prove that a depth two Hopf subalgebra K of a semisimple Hopf algebra H is
normal (where the ground field $k$ is algebraically closed of characteristic
zero). This means on the one hand that a Hopf subalgebra is normal when
inducing (then restricting) modules several times as opposed to one time
creates no new simple constituents. This point of view was taken in the paper
http://arxiv.org/abs/math/0409346 which established a normality result in case
H and K are finite group algebras. On the other hand this means that K is
normal in H when H | K is a Galois extension with respect to action of
generalized bialgebras such as bialgebroids, weak Hopf algebras or Hopf
algebroids. The generalized Galois picture of depth two is the point of view we
take here: after showing the centralizer R is separable algebra via Hopf
invariant theory, we compute that the depth two semisimple Hopf algebra pair H
| K is free Frobenius extension with Markov trace satisfying all hypotheses
considered in Kadison and Nikshych, Frobenius Extensions and Weak Hopf
Algebras, J.Algebra 244 (2001). By the main theorem in that paper it is then a
Galois extension with action of semisimple weak Hopf algebra (also regular and
possessing Haar integral). Then the Galois canonical isomorphism (via coring
theory) restricted to integral induces algebra homomorphism from Hopf algebra
into weak Hopf algebra with kernel HK^+ = K^+H.


title: Central exclusive production of dijets at hadronic colliders

abstract:
  In view of the recent diffractive dijet data from CDF run II, we critically
re-evaluate the standard approach to the calculation of central production of
dijets in quasi-elastic hadronic collisions. We find that the process is
dominated by the non-perturbative region, and that even perturbative
ingredients, such as the Sudakov form factor, are not under theoretical
control. Comparison with data allows us to fix some of the uncertainties.
Although we focus on dijets, our arguments apply to other high-mass central
systems, such as the Higgs boson.


title:
Warming in systems with discrete spectrum: spectral diffusion of two
  dimensional electrons in magnetic field

abstract:
  Warming in complex physical systems, in particular global warming, attracts
significant contemporary interest. It is essential, therefore, to understand
basic physical mechanisms leading to overheating. It is well known that
application of an electric field to conductors heats electric charge carriers.
Often an elevated electron temperature describes the result of the heating.
This paper demonstrates that an electric field applied to a conductor with
discrete electron spectrum produces a non-equilibrium electron distribution,
which cannot be described by temperature. Such electron distribution changes
dramatically the conductivity of highly mobile two dimensional electrons in a
magnetic field, forcing them into a state with a zero differential resistance.
Most importantly the results demonstrate that, in general, the effective
overheating in the systems with discrete spectrum is significantly stronger
than the one in systems with continuous and homogeneous distribution of the
energy levels at the same input power.


title: Capillary filling with pseudo-potential binary Lattice-Boltzmann model

abstract:
  We present a systematic study of capillary filling for a binary fluid by
using a mesoscopic lattice Boltzmann model for immiscible fluids describing a
diffusive interface moving at a given contact angle with respect to the walls.
The phenomenological way to impose a given contact angle is analysed.
Particular attention is given to the case of complete wetting, that is contact
angle equal to zero. Numerical results yield quantitative agreement with the
theoretical Washburn law, provided that the correct ratio of the dynamic
viscosities between the two fluids is used. Finally, the presence of precursor
films is experienced and it is shown that these films advance in time with a
square-root law but with a different prefactor with respect to the bulk
interface.


title:
Collisional and Thermal Emission Models of Debris Disks: Towards
  Planetesimal Population Properties

abstract:
  Debris disks around main-sequence stars are believed to derive from
planetesimal populations that have accreted at early epochs and survived
possible planet formation processes. While debris disks must contain solids in
a broad range of sizes - from big planetesimals down to tiny dust grains -
debris disk observations are only sensitive to the dust end of the size
distribution. Collisional models of debris disks are needed to "climb up" the
ladder of the collisional cascade, from dust towards parent bodies,
representing the main mass reservoir of the disks. We have used our collisional
code to generate five disks around a sun-like star, assuming planetesimal belts
at 3, 10, 30, 100, and 200 AU with 10 times the Edgeworth-Kuiper-belt mass
density, and to evolve them for 10 Gyr. Along with an appropriate scaling rule,
this effectively yields a three-parametric set of reference disks (initial
mass, location of planetesimal belt, age). For all the disks, we have generated
spectral energy distributions (SEDs), assuming homogeneous spherical
astrosilicate dust grains. A comparison between generated and actually observed
SEDs yields estimates of planetesimal properties (location, total mass etc.).
As a test and a first application of this approach, we have selected five disks
around sun-like stars with well-known SEDs. In four cases, we have reproduced
the data with a linear combination of two disks from the grid (an "asteroid
belt" at 3 AU and an outer "Kuiper belt"); in one case a single, outer
component was sufficient. The outer components are compatible with "large
Kuiper belts" of 0.2-50 earth masses (in the bodies up to 100 km in size) with
radii of 100-200 AU.


title:
Estimates on the Probability of Outliers for Real Random Bargmann-Fock
  functions

abstract:
  In this paper we consider the distribution of the zeros of a real random
Bargmann-Fock function of one or more variables. For these random functions we
prove estimates for two types of families of events, both of which are large
deviations from the mean. First, we prove that the probability there are no
zeros in $[-r,r]^m\subset\R^m$ decays at least exponentially in terms of $r^m$.
For this event we also prove a lower bound on the order of decay, which we do
not expect to be sharp. Secondly, we compute the order of decay for the
probability of families of events where the volume of the complex zero set is
either much larger or much smaller then expected.


title: Precise predictions for LHC using a GOLEM

abstract:
  In this talk we present recent next-to-leading order results relevant for LHC
phenomenology obtained with the GOLEM method. After reviewing the status of
this Feynman diagrammatic approach for multi-leg one-loop calculations we
discuss three applications: the loop-induced process gg -> Z^*Z^* and the
virtual corrections to the five and six point processes qq -> ZZg and u ubar ->
s sbar c cbar. We demonstrate that our method leads to representations of such
amplitudes which allow for efficient phase space integration. In this context
we propose a reweighting technique of the leading order unweighted events by
local K-factors.


title: NGC300 X-1 and IC10 X-1: a new breed of black hole binary?

abstract:
  [ABRIDGED] IC10 X-1 has recently been confirmed as a black hole (BH) +
Wolf-Rayet (WR) X-ray binary, and NGC300 X-1 is thought to be. IC10 X-1 and
NGC300 X-1 have similar X-ray properties, with luminosities ~10^38 erg/s, and
orbital periods ~30 hr. We investigate similarities between these two, as well
as differences between them and the known Galactic BH binary systems. We have
examined XMM-Newton observations of NGC300 X-1 and IC10 X-1. We extracted
lightcurves and spectra; power density spectra (PDS) were constructed from the
lightcurves, and the X-ray emission spectra were modeled. Each source exhibits
PDS that are characteristic of disc-accreting X-ray binaries (XBs) in the high
state. In this state, Galactic XBs with known BH primaries have soft, thermal
emission; however the emission spectra of our targets are predominantly
non-thermal. Furthermore, the Observation 1 spectrum of NGC300 X-1 is
strikingly similar to that of IC10 X-1. The remarkable similarity between the
behaviour of NGC300 X-1 in Observation 1 and that of IC10 X-1 lends strong
evidence for NGC300 X-1 being a (BH+WR) binary. The unusual spectra of NGC300
X-1 and IC10 X-1 may be due to these systems existing in a persistently high
state, whereas all known BH LMXBs are transient. BH XBs in a persistent high
state could retain their corona, and hence exhibit a large non-thermal
component. LMC X-1 is a BH XB that has only been observed in the high state,
and its spectrum is remarkably similar to those of our targets. We therefore
classify NGC300 X-1, IC10 X-1 and perhaps LMC X-1 as a new breed of BH XB,
defined by their persistently high accretion rates and consequent stable disc
configuration and corona. This scenario may also explain the lack of
ultraluminous X-ray sources in the canonical soft state.


title: Weak-Interacting Holographic QCD

abstract:
  We propose a simple prescription for including low-energy weak-interactions
into the framework of holographic QCD, based on the standard AdS/CFT dictionary
of double-trace deformations. As our proposal enables us to calculate various
electro-weak observables involving strongly coupled QCD, it opens a new
perspective on phenomenological applications of holographic QCD. We illustrate
efficiency and usefulness of our method by performing a few exemplar
calculations; neutron beta decay, charged pion weak decay, and meson-nucleon
parity non-conserving (PNC) couplings. The idea is general enough to be
implemented in both Sakai-Sugimoto as well as Hard/Soft Wall models.


title: The Freiheitssatz and the automorphisms of free right-symmetric algebras

abstract:
  We prove the Freiheitssatz for right-symmetric algebras and the decidability
of the word problem for right-symmetric algebras with a single defining
relation. We also prove that two generated subalgebras of free right-symmetric
algebras are free and automorphisms of two generated free right-symmetric
algebras are tame.


title: Controlled Coupling and Occupation of Silicon Atomic Quantum Dots

abstract:
  It is discovered that the zero-dimensional character of the silicon atom
dangling bond (DB) state allows controlled formation and occupation of a new
form of quantum dot assemblies. Whereas on highly doped n-type substrates
isolated DBs are negatively charged, it is found that Coulomb repulsion causes
DBs separated by less than ~2 nm to experience reduced localized charge. The
unoccupied states so created allow a previously unobserved electron
tunnel-coupling of DBs, evidenced by a pronounced change in the time-averaged
view recorded by scanning tunneling microscopy. Direct control over net
electron occupation and tunnel-coupling of multi-DB ensembles through
separation controlled is demonstrated. Through electrostatic control, it is
shown that a pair of tunnel-coupled DBs can be switched from a symmetric
bi-stable state to one exhibiting an asymmetric electron occupation. Similarly,
the setting of an antipodal state in a square assembly of four DBs is achieved,
demonstrating at room temperature the essential building block of a quantum
cellular automata device.


title: Lightweight Security for Network Coding

abstract:
  Under the emerging network coding paradigm, intermediate nodes in the network
are allowed not only to store and forward packets but also to process and mix
different data flows. We propose a low-complexity cryptographic scheme that
exploits the inherent security provided by random linear network coding and
offers the advantage of reduced overhead in comparison to traditional
end-to-end encryption of the entire data. Confidentiality is achieved by
protecting (or "locking") the source coefficients required to decode the
encoded data, without preventing intermediate nodes from running their standard
network coding operations. Our scheme can be easily combined with existing
techniques that counter active attacks.


title: Gravitational Geons in 1+1 Dimensions

abstract:
  It is well known that general relativity does not admit gravitational geons
that are stationary, asymptotically flat, singularity free and topologically
trivial. However, it is likely that general relativity will receive corrections
at large curvatures and the modified field equations may admit solutions
corresponding to this type of geon. If geons are produced in the early universe
and survive until today they could account for some of the dark matter that has
been "observed" in galaxies and galactic clusters.
  In this paper I consider gravitational geons in 1+1 dimensional theories of
gravity. I show that the Jackiw-Teitelboim theory with corrections proportional
to $R^2$ and $\Box R$ admits gravitational geons. I also show that
gravitational geons exist in a class of theories that includes Lagrangians
proportional to $R^{2/3}$.


title: Neutrino Mixing and the Private Higgs

abstract:
  We extend the Private Higgs scenario to account for charged lepton and
neutrino masses by introducing a private Higgs field for each lepton family. We
analyze a model in which neutrino Majorana masses are radiatively induced.
Contrary to previous models the neutrino mass scale ~ 10^{-2} eV is naturally
obtained without excessive fine tunings. The model requires the introduction of
SU(2) singlet scalar fields, two charged and one neutral. We discuss a possible
realization giving a normal neutrino mass hierarchy. Our model fits data and
predicts a non-zero V_{e3}.


title: Asperity contacts at the nanoscale: comparison of Ru and Au

abstract:
  We develop and validate an interatomic potential for ruthenium based on the
embedded atom method framework with the Finnis/Sinclair representation. We
confirm that the new potential yields a stable hcp lattice with reasonable
lattice and elastic constants and surface and stacking fault energies. We
employ molecular dynamics simulations to bring two surfaces together; one flat
and the other with a single asperity. We compare the process of asperity
contact formation and breaking in Au and Ru, two materials currently in use in
micro electro mechanical system switches. While Au is very ductile at 150 and
300 K, Ru shows considerably less plasticity at 300 and 600 K (approximately
the same homologous temperature). In Au, the asperity necks down to a single
atom thick bridge at separation. While similar necking occurs in Ru at 600 K,
it is much more limited than in Au. On the other hand, at 300 K, Ru breaks by a
much more brittle process of fracture/decohesion with limited plastic
deformation.


title:
Distinguished Torsion, Curvature and Deflection Tensors in the
  Multi-Time Hamilton Geometry

abstract:
  The aim of this paper is to present the main geometrical objects on the dual
1-jet bundle $J^{1*}(\cal{T},M)$ (this is the polymomentum phase space of the
De Donder-Weyl covariant Hamiltonian formulation of field theory) that
characterize our approach of multi-time Hamilton geometry. In this direction,
we firstly introduce the geometrical concept of a nonlinear connection $N$ on
the dual 1-jet space $J^{1*}(\cal{T},M)$. Then, starting with a given
$N$-linear connection $D$ on $J^{1*}(\cal{T},M)$, we describe the adapted
components of the torsion, curvature and deflection distinguished tensors
attached to the $N$-linear connection $D$.


title: Blazhko Effect in Double Mode Cepheids

abstract:
  Systematic survey for multiperiodicity in the LMC Cepheids (Moskalik,
Kolaczkowski & Mizerski 2004, 2006) has led to discovery of several new forms
of pulsational behaviour. One of them is periodic amplitude and phase
modulation observed in many first/second overtone (FO/SO) double mode Cepheids.
In the current paper we present detailed discussion of this newly discovered
phenomenon, based on a combined OGLE+MACHO sample of double mode pulsators.


title: Pressure induced superconductivity in CaFe$_2$As$_2$

abstract:
  CaFe$_2$As$_2$ has been found to be exceptionally sensitive to the
application of hydrostatic pressure and superconductivity has been found to
exist in a narrow pressure region that appears to be at the interface between
two different phase transitions. The pressure - temperature ($P - T$) phase
diagram of CaFe$_2$As$_2$ reveals that this stoichiometric, highly ordered,
compound can be easily tuned to reveal all the salient features associated with
FeAs-based superconductivity without introducing any disorder. Whereas at
ambient pressure CaFe$_2$As$_2$ does not superconduct for $T > 1.8$ K and
manifests a first order structural phase transition near $T \approx 170$ K, the
application of $\sim 5$ kbar hydrostatic pressure fully suppresses the
resistive signature of the structural phase transition and instead
superconductivity is detected for $T < 12$ K. For $P \ge 5.5$ kbar a different
transition is detected, one associated with a clear reduction in resistivity
and for $P > 8.6$ kbar superconductivity is no longer detected. This higher
pressure transition temperature increases rapidly with increasing pressure,
exceeding 300 K by $P \sim 17$ kbar. The low temperature, superconducting dome
is centered around 5 kbar, extending down to 2.3 kbar and up to 8.6 kbar. This
superconducting phase appears to exist when the low pressure transition is
suppressed sufficiently, but before the high pressure transition has reduced
the resistivity, and possibly the associated fluctuations, too dramatically.


title: The Anomalous Acceleration of the Pioneer Spacecrafts

abstract:
  Radiometric data from the Pioneer 10 and 11 spacecrafts have revealed an
unexplained constant acceleration of a_A = (8.74 +/- 1.33) x 10^(-10) m s^(-2)
towards the Sun, also known as the Pioneer anomaly. Different groups have
analyzed the Pioneer data and have got the same results, which rules out
computer programming and handling errors. Attempts to explain this phenomenon
arguing intrinsic causes on-board the spacecrafts failed or have lead to
inconclusive results. Therefore, the Pioneer anomalous acceleration has
motivated the interest of researchers to find out explanations that could bring
insight upon the forces acting in the outer Solar Systems or a hint to discover
new natural laws.


title: Midgap spectrum of the fermion-vortex system

abstract:
  I study the midgap spectrum of the fermion-vortex system in two spatial
dimensions. The existence of bound states, in addition to the zero modes found
by Jackiw and Rossi, is established. For a singly quantized vortex, I present
complete analytical solutions in terms of generalized Laguerre polynomials in
the opposite limits of vanishing and large vortex core size. There is an
infinite number of such bound states, with a spectrum that is, when squared,
given by, respectively, the Coulomb potential and the isotropic harmonic
oscillator. Possible experimental signatures of this spectrum in
condensed-matter realizations of the system are pointed out.


title: Galois covers of the open p-adic disc

abstract:
  This paper investigates Galois branched covers of the open $p$-adic disc and
their reductions to characteristic $p$. Using the field of norms functor of
Fontaine and Wintenberger, we show that the special fiber of a Galois cover is
determined by arithmetic and geometric properties of the generic fiber and its
characteristic zero specializations. As applications, we derive a criterion for
good reduction in the abelian case, and give an arithmetic reformulation of the
local Oort Conjecture concerning the liftability of cyclic covers of germs of
curves.


title:
L-functions for holomorphic forms on GSp(4) x GL(2) and their special
  values

abstract:
  We provide an explicit integral representation for L-functions of pairs (F,g)
where F is a holomorphic genus 2 Siegel newform and g a holomorphic elliptic
newform, both of squarefree levels and of equal weights. When F,g have level
one, this was earlier known by the work of Furusawa. The extension is not
straightforward. Our methods involve precise double-coset and volume
computations as well as an explicit formula for the Bessel model for GSp(4) in
the Steinberg case; the latter is possibly of independent interest. We apply
our integral representation to prove an algebraicity result for a critical
special value of L(s, F \times g). This is in the spirit of known results on
critical values of triple product L-functions, also of degree 8, though there
are significant differences.


title: Far-from-Equilibrium Measurements of Thermodynamic Length

abstract:
  Thermodynamic length is a path function that generalizes the notion of length
to the surface of thermodynamic states. Here, we show how to measure
thermodynamic length in far-from-equilibrium single molecule experiments using
the work fluctuation relations. For these microscopic systems, it proves
necessary to define the thermodynamic length in terms of the Fisher
information. Consequently, the thermodynamic length can be directly related to
the magnitude of fluctuations about equilibrium. The work fluctuation relations
link the work and the free energy change during an external perturbation on a
system. We use this result to determine equilibrium averages at intermediate
points of the protocol in which the system is out-of-equilibrium. This allows
us to extend Bennett's method to determine the potential of mean force, as well
as the thermodynamic length, in single molecule experiments.


title:
The dark matter transfer function: free streaming, particle statistics
  and memory of gravitational clustering

abstract:
  The transfer function $T(k)$ of dark matter (DM) perturbations during matter
domination is obtained by solving the collisionless Boltzmann-Vlasov equation.
We find an \emph{exact} expression for $T(k)$ for \emph{arbitrary} distribution
functions of decoupled particles and initial conditions}. We find a remarkably
accurate and simple approximation valid on all scales of cosmological relevance
for structure formation in the linear regime. The natural scale of suppression
is the free streaming wavevector at matter-radiation equality, $ k_{fs}(t_{eq})
= [{4\pi\rho_{0M}}/{[< \vec{V}^2> (1+z_{eq})]} ]^\frac12 $. An important
ingredient is a non-local kernel determined by the distribution functions of
the decoupled particles which describes the \emph{memory of the initial
conditions and gravitational clustering} and yields a correction to the fluid
description. Distribution functions that favor the small momentum region lead
to an \emph{enhancement of power at small scales} $ k > k_{fs}(t_{eq}) $. For
DM thermal relics that decoupled while ultrarelativistic we find $
k_{fs}(t_{eq}) \simeq 0.003 (g_d/2)^\frac13 (m/\mathrm{keV})
[\mathrm{kpc}]^{-1} $, where $ g_d $ is the number of degrees of freedom at
decoupling. For WIMPS we obtain $ k_{fs}(t_{eq}) = 5.88 (g_d/2)^\frac13 (m/100
\mathrm{GeV})^\frac12 (T_d/10 \mathrm{MeV})^\frac12 [\mathrm{pc}]^{-1} $. For
$k\ll k_{fs}(t_{eq})$, $T(k) \sim 1-\mathrm{C}[k/k_{fs}(t_{eq})]^2 $ where $C
=\mathrm{O}(1)$ for all cases considered and simple and accurate fits for
\emph{small} scales.


title: Nonradial Modes in Classical Cepheids

abstract:
  Systematic search for multiperiodicity in the LMC Cepheids (Moskalik,
Kolaczkowski & Mizerski 2004) has led to discovery of low amplitude nonradial
modes in a substantial fraction of overtone pulsators. We present detailed
discussion of this new type of multimode Cepheid pulsators and compare them to
similar nonradial pulsators discovered among RR Lyrae stars. Finally, we show
first detections of secondary nonradial modes in FU/FO double-mode Cepheids.


title:
A Markov Chain Monte Carlo Algorithm for analysis of low signal-to-noise
  CMB data

abstract:
  We present a new Monte Carlo Markov Chain algorithm for CMB analysis in the
low signal-to-noise regime. This method builds on and complements the
previously described CMB Gibbs sampler, and effectively solves the low
signal-to-noise inefficiency problem of the direct Gibbs sampler. The new
algorithm is a simple Metropolis-Hastings sampler with a general proposal rule
for the power spectrum, C_l, followed by a particular deterministic rescaling
operation of the sky signal. The acceptance probability for this joint move
depends on the sky map only through the difference of chi-squared between the
original and proposed sky sample, which is close to unity in the low
signal-to-noise regime. The algorithm is completed by alternating this move
with a standard Gibbs move. Together, these two proposals constitute a
computationally efficient algorithm for mapping out the full joint CMB
posterior, both in the high and low signal-to-noise regimes.


title: Type II Migration: Varying Planet Mass and Disc Viscosity

abstract:
  This paper continues an earlier study of giant planet migration, examining
the effect of planet mass and disc viscosity on the migration rate. We find
that the migration rate of a gap-opening planet varies systematically with the
planet's mass, as predicted in our earlier work. However, the variation with
disc viscosity appears to be much weaker than expected.


title:
Asymptotic Mean Time To Failure and Higher Moments for Large, Recursive
  Networks

abstract:
  This paper deals with asymptotic expressions of the Mean Time To Failure
(MTTF) and higher moments for large, recursive, and non-repairable systems in
the context of two-terminal reliability. Our aim is to extend the well-known
results of the series and parallel cases. We first consider several exactly
solvable configurations of identical components with exponential failure-time
distribution functions to illustrate different (logarithmic or power-law)
behaviors as the size of the system, indexed by an integer n, increases. The
general case is then addressed: it provides a simple interpretation of the
origin of the power-law exponent and an efficient asymptotic expression for the
total reliability of large, recursive systems. Finally, we assess the influence
of the non-exponential character of the component reliability on the
n-dependence of the MTTF.


title: Belief decision support and reject for textured images characterization

abstract:
  The textured images' classification assumes to consider the images in terms
of area with the same texture. In uncertain environment, it could be better to
take an imprecise decision or to reject the area corresponding to an unlearning
class. Moreover, on the areas that are the classification units, we can have
more than one texture. These considerations allows us to develop a belief
decision model permitting to reject an area as unlearning and to decide on
unions and intersections of learning classes. The proposed approach finds all
its justification in an application of seabed characterization from sonar
images, which contributes to an illustration.


title:
Explicit large nuclear charge limit of electronic ground states for Li,
  Be, B, C, N, O, F, Ne and basic aspects of the periodic table

abstract:
  This paper is concerned with the Schr\"odinger equation for atoms and ions
with N=1 to 10 electrons. In the asymptotic limit of large nuclear charge $Z$,
we determine explicitly the low-lying energy levels and eigenstates.
  The asymptotic energies and wavefunctions are in good quantitative agreement
with experimental data for positive ions, and in excellent qualitative
agreement even for neutral atoms ($Z=N$). In particular, the predicted ground
state spin and angular momentum quantum numbers ($^1S$ for He, Be, Ne, $^2S$
for H and Li, $^4S$ for N, $^2P$ for B and F, and $^3P$ for C and O) agree with
experiment in every case.
  The asymptotic Schr\"odinger ground states agree, up to small corrections,
with the semi-empirical hydrogen orbital configurations developed by Bohr, Hund
and Slater to explain the periodic table. In rare cases where our results
deviate from this picture, such as the ordering of the lowest ${}^1D^o$ and
${}^3S^o$ states of the Carbon isoelectronic sequence, experiment confirms our,
not Hund's, predictions.


title: Exact two-terminal reliability of some directed networks

abstract:
  The calculation of network reliability in a probabilistic context has long
been an issue of practical and academic importance. Conventional approaches
(determination of bounds, sums of disjoint products algorithms, Monte Carlo
evaluations, studies of the reliability polynomials, etc.) only provide
approximations when the network's size increases, even when nodes do not fail
and all edges have the same reliability p. We consider here a directed, generic
graph of arbitrary size mimicking real-life long-haul communication networks,
and give the exact, analytical solution for the two-terminal reliability. This
solution involves a product of transfer matrices, in which individual
reliabilities of edges and nodes are taken into account. The special case of
identical edge and node reliabilities (p and rho, respectively) is addressed.
We consider a case study based on a commonly-used configuration, and assess the
influence of the edges being directed (or not) on various measures of network
performance. While the two-terminal reliability, the failure frequency and the
failure rate of the connection are quite similar, the locations of complex
zeros of the two-terminal reliability polynomials exhibit strong differences,
and various structure transitions at specific values of rho. The present work
could be extended to provide a catalog of exactly solvable networks in terms of
reliability, which could be useful as building blocks for new and improved
bounds, as well as benchmarks, in the general case.


title:
Discrete Accidental Symmetry for a Particle in a Constant Magnetic Field
  on a Torus

abstract:
  A classical particle in a constant magnetic field undergoes cyclotron motion
on a circular orbit. At the quantum level, the fact that all classical orbits
are closed gives rise to degeneracies in the spectrum. It is well-known that
the spectrum of a charged particle in a constant magnetic field consists of
infinitely degenerate Landau levels. Just as for the $1/r$ and $r^2$
potentials, one thus expects some hidden accidental symmetry, in this case with
infinite-dimensional representations. Indeed, the position of the center of the
cyclotron circle plays the role of a Runge-Lenz vector. After identifying the
corresponding accidental symmetry algebra, we re-analyze the system in a finite
periodic volume. Interestingly, similar to the quantum mechanical breaking of
CP invariance due to the $\theta$-vacuum angle in non-Abelian gauge theories,
quantum effects due to two self-adjoint extension parameters $\theta_x$ and
$\theta_y$ explicitly break the continuous translation invariance of the
classical theory. This reduces the symmetry to a discrete magnetic translation
group and leads to finite degeneracy. Similar to a particle moving on a cone, a
particle in a constant magnetic field shows a very peculiar realization of
accidental symmetry in quantum mechanics.


title:
Distinct Scaling Regimes of Energy Release Dynamics in the Nighttime
  Magnetosphere

abstract:
  Based on a spatiotemporal analysis of POLAR UVI images, we show that the
auroral emission events that initiate equatorward of the isotropic boundary
(IB) obtained from a time-dependent empirical model, have systematically
steeper power-law slopes of energy, power, area and lifetime probability
distributions compared to the events that initiate poleward of the IB. The
low-latitude group of events contains a distinct subpopulation of
substorm-scale disturbances violating the power-law behavior, while the high
latitude group is described by nearly perfect power-law statistics over the
entire range of scales studied. The results obtained indicate that the inner
and outer portions of the plasma sheet are characterized by substantially
different scaling regimes of bursty energy dissipation suggestive of different
physics in these regions.


title:
Strong coupling between magnetic and structural order parameters in
  SrFe2As2

abstract:
  X-ray and Neutron diffraction as well as muon spin relaxation and M\"ossbauer
experiments performed on SrFe$_2$As$_2$ polycrystalls confirm a sharp first
order transition at $T_0 = 205$,K corresponding to an orthorhombic phase
distortion and to a columnar antiferromagnetic Fe ordering with a propagation
vector (1,0,1), and a larger distortion and larger size of the ordered moment
than reported for BaFe$_2$As$_2$. The structural and the magnetic order
parameters present an remarkable similarity in their temperature dependence
from $T_0$ down to low temperatures, showing that both phenomena are intimately
connected. Accordingly, the size of the ordered Fe moments scale with the
lattice distortion when going from SrFe$_2$As$_2$ to BaFe$_2$As$_2$.
Full-potential band structure calculations confirm that the columnar magnetic
order and the orthorhombic lattice distortion are intrinsically tied to each
other.


title: AdS/NRCFT for the (super) Calogero model

abstract:
  We propose a correspondence between the non-relativistic quantum Calogero
model in d spatial dimensions and classical gravity theory in a deformed
AdS_{d+3} background for single particle and AdS_{Nd+3} for N-particles. Later
we extend our construction to the superspace for a super Calogero model.


title: LGS AO Science Impact: Present and Future Perspectives

abstract:
  The recent advent of laser guide star adaptive optics (LGS AO) on the largest
ground-based telescopes has enabled a wide range of high angular resolution
science, previously infeasible from ground-based and/or space-based
observatories. As a result, scientific productivity with LGS has seen enormous
growth in the last few years, with a factor of ~10 leap in publication rate
compared to the first decade of operation. Of the 54 refereed science papers to
date from LGS AO, half have been published in the last ~2 years, and these LGS
results have already made a significant impact in a number of areas. At the
same time, science with LGS AO can be considered in its infancy, as astronomers
and instrumentalists are only beginning to understand its efficacy for
measurements such as photometry, astrometry, companion detection, and
quantitative morphology. We examine the science impact of LGS AO in the last
few years of operations, largely due to the new system on the Keck II 10-meter
telescope. We review currently achieved data quality, including results from
our own ongoing brown dwarf survey with Keck LGS. We assess current and
near-future performance with a critical eye to LGS AO's capabilities and
deficiencies. From both qualitative and quantitative considerations, it is
clear that the era of regular and important science from LGS AO has arrived.


title:
Vega library for processing DICOM data required in Monte Carlo
  verification of radiotherapy treatment plans

abstract:
  Monte Carlo (MC) methods provide the most accurate to-date dose calculations
in heterogeneous media and complex geometries, and this spawns increasing
interest in incorporating MC calculations into treatment planning quality
assurance process. This involves MC dose calculations for clinically produced
treatment plans. To perform these calculations, a number of treatment plan
parameters specifying radiation beam and patient geometries need to be
transferred to MC codes, such as BEAMnrc and DOSXYZnrc. Extracting these
parameters from DICOM files is not a trivial task, one that has previously been
performed mostly using Matlab-based software. This paper describes the DICOM
tags that contain information required for MC modeling of conformal and IMRT
plans, and reports the development of an in-house DICOM interface, through a
library (named Vega) of platform-independent, object-oriented C++ codes. The
Vega library is small and succinct, offering just the fundamental functions for
reading/modifying/writing DICOM files in a C++ program. The library, however,
is flexible enough to extract all MC required data from DICOM files, and write
MC produced dose distributions into DICOM files that can then be processed in a
treatment planning system environment. The library can be made available upon
request to the authors.


title:
On the baryonic, stellar, and luminous scaling relations of disk
  galaxies

abstract:
  We explore how the slopes and scatters of the scaling relations of disk
galaxies (Vm-L[-M], R-L[-M], and Vm-R) do change when moving from B to K bands
and to stellar and baryonic quantities. For our compiled sample of 76 normal,
non-interacting high and low surface brightness galaxies, we find some changes,
which evidence evolution effects, mainly related to gas infall and star
formation (SF). We also explore correlations among the (B-K) color, stellar
mass fraction fs, mass M (luminosity L), and surface density (SB), as well as
correlations among the residuals of the scaling relations. Some of our findings
are: (i) the scale length Rb is a third parameter in the baryonic TF relation
and the residuals of this relation follow a trend (slope ~-0.15) with the
residuals of the Rb-Mb relation; for the stellar and K band cases, R is not
anymore a third parameter and the mentioned trend disappears; (ii) among the
TFRs, the B-band TFR is the most scattered; in this case, the color is a third
parameter; (iii) the LSB galaxies break some observed trends, which suggest a
threshold in the gas surface density Sg, below which the SF becomes independent
of the gas infall rate and Sg. Our results are interpreted and discussed in the
light of LCDM-based models of galaxy evolution. The models explain not only the
baryonic scaling relations, but also most of the processes responsible for the
observed changes in the slopes, scatters, and correlations among the residuals
when changing to stellar and luminous quantities. The baryon fraction is
required to be smaller than 0.05 on average. We detect some potential
difficulties for the models: the observed color-M and surface density-M
correlations are steeper, and the intrinsic scatter in the baryonic TFR is
smaller than those predicted. [abridged]


title: Hypergeometric functions with rational arguments

abstract:
  We elaborate on the expansion of hypergeometric functions about rational
parameters, where we focus mainly on the integer and half-integer case. The
strategy and the basic steps of a recently developed algorithm for the
expansion about half-integer parameters are described. The algorithm is
implemented in the Mathematica package HypExp, by means of which we derive
(partially new) results of selected multi-loop Feynman diagrams. Moreover, we
give a new formulation of a conjecture in the context of a three-loop master
integral in HQET.


title:
Spontaneous Particle-Hole Symmetry Breaking in the $\nu=5/2$ Fractional
  Quantum Hall Effect

abstract:
  The essence of the $\nu=5/2$ fractional quantum Hall effect is believed to be
well captured by the Moore-Read Pfaffian (or anti-Pfaffian) description.
However, an important mystery regarding the formation of the Pfaffian state is
the role of the three-body interaction Hamiltonian $H_3$ that produces the
Pfaffian as an exact ground state and the concomitant particle-hole symmetry
breaking. We show that a two-body interaction Hamiltonian $H_2$ constructed via
particle-hole symmetrization of $H_3$ produces a ground state nearly exactly
approximating the Pfaffian and anti-Pfaffian states, respectively, in the
spherical geometry. More importantly, the ground state energy of $H_2$ is shown
to exhibit a ``Mexican-hat'' structure as a function of particle number in the
vicinity of half filling for a given flux indicating spontaneous particle-hole
symmetry breaking. We do not find any such Mexican-hat signature in the second
Landau level Coulomb interaction at 5/2.


title: Virtual Processes and Superradiance in Spin-Boson Models

abstract:
  We consider spin-boson models composed by a single bosonic mode and an
ensemble of $N$ identical two-level atoms. The situation where the coupling
between the bosonic mode and the atoms generates real and virtual processes is
studied, where the whole system is in thermal equilibrium with a reservoir at
temperature $\beta^{-1}$. Phase transitions from ordinary fluorescence to
superradiant phase in three different models is investigated. First a model
where the coupling between the bosonic mode and the $j-th$ atom is via the
pseudo-spin operator $\sigma^{,z}_{(j)}$ is studied. Second, we investigate the
generalized Dicke model, introducing different coupling constants between the
single mode bosonic field and the environment, $g_{1}$ and $g_{2}$ for rotating
and counter-rotating terms, respectively. Finally it is considered a modified
version of the generalized Dicke model with intensity-dependent coupling in the
rotating terms. In the first model the zero mode contributes to render the
canonical entropy a negative quantity for low temperatures. The last two models
presents phase transitions, even when only Hamiltonian terms which generates
virtual processes are considered.


title: Splints of classical root systems

abstract:
  This article introduces a new term "splint" and classifies the splints of the
classical root systems. The motivation comes from representation theory of
semisimple Lie algebras. In a few instances, splints play a role in determining
branching rules of a module over a complex semisimple Lie algebra when
restricted to a subalgebra. In these particular cases, the set of submodules
with respect to the subalgebra themselves may be regarded as the character of
another Lie algebra.


title: Dynamic Model of Smoothing Problem in Water Power Systems

abstract:
  In this paper the problem of optimal performance of a power system is
considered. The problem is posed in various aspects within the frames of the
theory of optimal control of stores. Mathematical models are presented by means
of the recurrent equations of a dynamic programming. In the general case a new
method is presented which avoids the "curse of dimensionality."


title:
Synchrony and variability induced by spatially correlated additive and
  multiplicative noise in the coupled Langevin model

abstract:
  The synchrony and variability have been discussed of the coupled Langevin
model subjected to spatially correlated additive and multiplicative noise. We
have employed numerical simulations and the analytical augmented-moment method
which is the second-order moment method for local and global variables [H.
Hasegawa, Phys. Rev. E {\bf 67}, 041903 (2003)]. It has been shown that the
synchrony of an ensemble is increased (decreased) by a positive (negative)
spatial correlation in both additive and multiplicative noise. Although the
variability for local fluctuations is almost insensitive to spatial
correlations, that for global fluctuations is increased (decreased) by positive
(negative) correlations. When a pulse input is applied, the synchrony is
increased for the correlated multiplicative noise, whereas it may be decreased
for correlated additive noise coexisting with uncorrelated multiplicative
noise. An application of our study to neuron ensembles has demonstrated the
possibility that information is conveyed by the variance and synchrony in input
signals, which accounts for some neuronal experiments.


title: Finite-Size Effects for Multi-Magnon States

abstract:
  We propose the generalized Luscher formula for multi-magnon states by which
one can compute the finite-size correction to the energy of multi giant magnons
at classical and one-loop levels. It is shown that the F-term of our formula is
consistent with the exact finite-size spectrum of the sinh-Gordon model, and
the mu-term agrees with the finite-size energy of magnon boundstate of the
asymptotic Bethe Ansatz in the su(2) sector at strong coupling. In an appendix,
we evaluate our formula at weak coupling under some approximations, and find
that the transcendental terms arise from a sum over an infinite tower of BPS
boundstates.


title:
Greedy D-Approximation Algorithm for Covering with Arbitrary Constraints
  and Submodular Cost

abstract:
  This paper describes a simple greedy D-approximation algorithm for any
covering problem whose objective function is submodular and non-decreasing, and
whose feasible region can be expressed as the intersection of arbitrary (closed
upwards) covering constraints, each of which constrains at most D variables of
the problem. (A simple example is Vertex Cover, with D = 2.) The algorithm
generalizes previous approximation algorithms for fundamental covering problems
and online paging and caching problems.


title: Searches for Large Extra Dimensions at the Tevatron

abstract:
  The presence of extra dimensions can be probed in high energy collisions via
the production or exchange of gravitons. The former corresponds to signatures
with missing energy while the latter corresponds to modifications of the final
state spectra. Here I review results of analyses performed by the CDF and D0
Collaborations on ppbar collisions at 1.96 TeV in signatures sensitive to large
extra dimensions. These include analyses of photon+(missing transverse energy)
and jet+(missing transverse energy) as signatures of graviton production as
well as analyses of dilepton and diboson final states sensitive to graviton
exchange.


title: Clustering properties of a sterile neutrino dark matter candidate

abstract:
  The clustering properties of sterile neutrinos are studied within an
extension of the minimal standard model, where these are produced via the decay
of a gauge singlet scalar. The distribution function after decoupling is
strongly out of equilibrium. (DM) abundance and phase space density constraints
from (dSphs) constrain the mass in the $\mathrm{keV}$ range consistent with a
gauge singlet with mass and vacuum expectation value $\sim 100,\mathrm{GeV}$
decoupling at this temperature. The (DM) transfer function and power spectrum
are obtained from the solution of the non-relativistic Boltzmann-Vlasov
equation in the matter dominated era. The small momentum enhancement of the
distribution function leads to long range memory of gravitational clustering
and a \emph{substantial enhancement of the power spectrum at small scales
compared to a thermal relic or sterile neutrino produced via non-resonant
mixing with active neutrinos}. The scale of suppression of the power spectrum
for such sterile neutrino with $m\sim \mathrm{keV}$ is $\lambda \sim 488
,\mathrm{kpc}$. At large scales $T(k)\sim 1-C, k^2/k^2_{fs}(t_{eq}) +...$ with
$C \sim \mathrm{O}(1)$. At small scales $65 \mathrm{kpc} \lesssim \lambda
\lesssim 500 \mathrm{kpc}$ corrections to the fluid description and memory of
gravitational clustering become important, and we find $T(k) \simeq 1.902
e^{-k/k_{fs}(t_{eq})}$, where $k_{fs}(t_{eq}) \sim 0.013/\mathrm{kpc}$ is the
free streaming wavevector at matter-radiation equality. The enhancement of
power at small scales may provide a possible relief to the tension between the
constraints from X-ray and Lyman-$\alpha$ forest data.


title:
New constraints on H_0 and Omega_M from SZE/X-RAY data and Baryon
  Acoustic Oscillations

abstract:
  The Hubble constant, $H_0$, sets the scale of the size and age of the
Universe and its determination from independent methods is still worthwhile to
be investigated. In this article, by using the Sunyaev-Zel`dovich effect and
X-ray surface brightness data from 38 galaxy clusters observed by Bonamente
{\it{et al.}} (2006), we obtain a new estimate of $H_0$ in the context of a
flat $\Lambda$CDM model. There is a degeneracy on the mass density parameter
($\Omega_{m}$) which is broken by applying a joint analysis involving the
baryon acoustic oscillations (BAO) as given by Sloan Digital Sky Survey (SDSS).
This happens because the BAO signature does not depend on $H_0$. Our basic
finding is that a joint analysis involving these tests yield $H_0=
0.765^{+0.035}_{-0.033}$ km s$^{-1}$ Mpc$^{-1}$ and
$\Omega_{m}=0.27^{+0.03}_{-0.02}$. Since the hypothesis of spherical geometry
assumed by Bonamente {\it {et al.}} is questionable, we have also compared the
above results to a recent work where a sample of triaxial galaxy clusters has
been considered.


title: Two-Photon Decays Reexamined: Cascade Contributions and Gauge Invariance

abstract:
  The purpose of this paper is to calculate the two-photon decay rate
corresponding to the two-photon transitions nS->1S and nD->1S in hydrogenlike
ions with a low nuclear charge number Z (for principal quantum numbers n =
2,...,8. Numerical results are obtained within a nonrelativistic framework, and
the results are found to scale approximately as (Z alpha)^6/n^3, where alpha is
the fine-structure constant. We also attempt to clarify a number of subtle
issues regarding the treatment of the coherent, quasi-simultaneous emission of
the two photons as opposed to one-photon cascades. In particular, the gauge
invariance of the decay rate is shown explicitly.


title:
Search for Oscillation of the Electron-Capture Decay Probability of
  $^{142}$Pm

abstract:
  We have searched for time modulation of the electron capture decay
probability of $^{142}$Pm in an attempt to confirm a recent claim from a group
at the Gesellschaft f\"{u}r Schwerionenforschung (GSI). We produced $^{142}$Pm
via the $^{124}$Sn($^{23}$Na, 5n)$^{142}$Pm reaction at the Berkeley 88-Inch
Cyclotron with a bombardment time short compared to the reported modulation
period. Isotope selection by the Berkeley Gas-filled Separator is followed by
implantation and a long period of monitoring the $^{142}$Nd K$_{\alpha}$ x-rays
from the daughter. The decay time spectrum of the x-rays is well-described by a
simple exponential and the measured half-life of 40.68(53) seconds is
consistent with the accepted value. We observed no oscillatory modulation at
the proposed frequency at a level 31 times smaller than that reported by
Litvinov {\it et al.} (Phys. Lett. B 664 (2008) 162; arXiv:0801.2079
[nucl-ex]). A literature search for previous experiments that might have been
sensitive to the reported modulation uncovered another example in $^{142}$Eu
electron-capture decay. A reanalysis of the published data shows no oscillatory
behavior.


title: Alpha_s(M_Z) from hadronic tau decays

abstract:
  We perform an extraction of alpha_s based on sum rules involving isovector
hadronic tau decay data. The particular sum rules employed are constructed
specifically to suppress contributions associated with poorly known higher
dimension condensates, and hence reduce theoretical systematic uncertainties
associated with the treatment of such contributions which are shown to be
present in earlier related analyses. Running our results from the n_f=3 to
n_f=5 regime we find alpha_s(M_Z^2)=0.1187(16), in excellent agreement with the
recently updated global fit to electroweak data at the Z scale, 0.1191(27), and
other high-scale direct determinations.


title:
Relativistic calculation of the two-photon decay rate of highly-excited
  ionic states

abstract:
  Based on quantum electrodynamics, we reexamine the two-photon decay of
one-electron atoms. Special attention is paid to the calculation of the
(two-photon) total decay rates which can be viewed as the imaginary part of the
two-loop self-energy. We argue that our approach can easily be applied to the
cases with a virtual state having an intermediate energy between the initial
and the final state of the decay process leading, thus, to the resonance peaks
in the two-photon energy distribution. In order to illustrate our approach, we
obtain fully relativistic results, resolved into electric and magnetic
multipole components, for the two-photon decay rates of the 3S_{1/2} ->
1S_{1/2} transition in neutral hydrogen as well as in various hydrogen-like
ions.


title: Atomic Oxygen in the Comae of Comets

abstract:
  We report on the detection of atomic oxygen lines in the spectra of 8 comets.
These forbidden lines are a result of the photodissociation of the parent
oxygen-bearing species directly into an excited state. We used high resolution
spectra obtained at the McDonald Observatory 2.7m telescope to resolve the
cometary oxygen lines from the telluric oxygen lines and from other cometary
emissions. We find that the relative intensities of the two red lines (6300.304
and 6363.776A) are consistent with theory. The green line (5577.339A) has an
intensity which is about 10% of the sum of the intensities of the two red
lines. We show that collisional quenching may be important in the inner coma.
If we assume the relative excitation rates of potential parents which have
appeared in the literature, then H2O would be the parent of the cometary green
oxygen line. However, those rates have been questioned. We measured the width
of the three oxygen lines and find that the green line is wider than either of
the two red lines. The finding of a wider line could imply a different parent
for the green and red lines. However, the constancy of the green to red line
flux ratio suggests the parent is the same for these lines but that the
exciting photons have different energies.


title: Algebra of formal vector fields on the line and Buchstaber's conjecture

abstract:
  Let L_1 denotes the Lie algebra of formal vector fields on the line which
vanish at the origin together with their first derivatives. Buchstaber and
Shokurov have shown that the universal enveloping algebra U(L_1) is isomorphic
to the tensor product of the Landweber-Novikov algebra S in complex cobordism
theory by reals. The cohomology H*(L_1) has trivial multiplication. Buchstaber
conjectured that H*(L_1) is generated with respect to non-trivial Massey
products by H^1(L_1). Feigin, Fuchs and Retakh found representation of H*(L_1)
by trivial Massey products. In the present article we prove that H*(L_1) is
generated with respect to non-trivial Massey products by two elements from
H^1(L_1).


title: The quaternionic Cullen-regular product for a larger class of functions

abstract:
  We introduce the regular product for Cullen-regular quaternionic functions in
a manner that does not depend upon a representation in power series but upon
another, weaker kind of representation. The special case when the functions are
represented as quaternionic power series is studied. We show that the regular
ring of quaternionic power series is a subring of the regular associative ring
of real-analytical Hyperholomorphic functions.


title:
Accurate calculation of eigenvalues and eigenfunctions. I: Symmetric
  potentials

abstract:
  We describe a method for the calculation of accurate energy eigenvalues and
expectation values of observables of separable quantum-mechanical models. We
discuss the application of the approach to one-dimensional anharmonic
oscillators with symmetric potential-energy functions.


title: Fabry-Perot temperature dependence and surface-mounted optical cavities

abstract:
  Factors that contribute to the temperature dependence of a resonant frequency
in a low-expansion optical cavity are discussed, including deformation at the
cavity ends due to different coefficients of thermal expansion (CTE) of the
spacer, optically-contacted mirror substrate and coating. A model of the
temperature dependence is presented that incorporates finite-element-analysis
of the cavity ends. A measurement of frequency versus temperature of a cavity
mode is used along with the model to deduce a spacers CTE versus temperature
profile. The measured profile correlates very well with a separate experiment
utilizing a temporary surface-mounted Fabry-Perot cavity fabricated on the
outside of the spacer with hydroxy-catalysis bonding.


title:
Discovery and Interpretation of an X-ray Period in the Galactic Center
  Source CXOGC J174536.1-285638

abstract:
  We present X-ray and infrared observations of the X-ray source CXOGC
J174536.1-285638. Previous observations suggest that this source may be an
accreting binary with a high-mass donor (HMXB) or a colliding wind binary
(CWB). Based on the Chandra and XMM-Newton light curve, we have found an
apparent 189+/-6 day periodicity with better than 99.997% confidence. We
discuss several possible causes of this periodicity, including both orbital and
superorbital interpretations. We explore in detail the possibility that the
X-ray modulation is related to an orbital period and discuss the implications
for two scenarios; one in which the variability is caused by obscuration of the
X-ray source by a stellar wind, and the other in which it is caused by an
eclipse of the X-ray source. We find that in the first case, CXOGC
J174536.1-285638 is consistent with both CWB and HMXB interpretations, but in
the second, CXOGC J174536.1-285638 is more likely a HMXB.


title: A diagrammatic approach to Hopf monads

abstract:
  Given a Hopf algebra in a symmetric monoidal category with duals, the
category of modules inherits the structure of a monoidal category with duals.
If the notion of algebra is replaced with that of monad on a monoidal category
with duals then Bruguieres and Virelizier showed when the category of modules
inherits this structure of being monoidal with duals, and this gave rise to
what they called a Hopf monad. In this paper it is shown that there are good
diagrammatic descriptions of dinatural transformations which allows the
three-dimensional, object-free nature of their constructions to become
apparent.


title: Role of dense matter in collective supernova neutrino transformations

abstract:
  For neutrinos streaming from a supernova (SN) core, dense matter suppresses
self-induced flavor transformations if the electron density n_e significantly
exceeds the neutrino density n_nu in the conversion region. If n_e is
comparable to n_nu one finds multi-angle decoherence, whereas the standard
self-induced transformation behavior requires that in the transformation region
n_nu is safely above n_e. This condition need not be satisfied in the early
phase after supernova core bounce. Our new multi-angle effect is a subtle
consequence of neutrinos traveling on different trajectories when streaming
from a source that is not point-like.


title: SN2007ax : An Extremely Faint Type Ia Supernova

abstract:
  We present multi-band photometric and optical spectroscopic observations of
SN2007ax, the faintest and reddest Type Ia supernova (SNIa) yet observed. With
M_B = -15.9 and (B-V)max = 1.2, this SN is over half a magnitude fainter at
maximum light than any other SNIa. Similar to subluminous SN2005ke, SN2007ax
also appears to show excess in UV emission at late time. Traditionally,
Delta-m_15(B) has been used to parameterize the decline rate for SNeIa.
However, the B-band transition from fast to slow decline occurs sooner than 15
days for faint SNeIa. Therefore we suggest that a more physically motivated
parameter, the time of intersection of the two slopes, be used instead. Only by
explaining the faintest (and the brightest) supernovae, we can thoroughly
understand the physics of thermonuclear explosions. We suggest that future
surveys should carefully design their cadence, depth, pointings and follow-up
to find an unbiased sample of extremely faint members of this subclass of faint
SNeIa.


title:
Collaborative Virtual Queue: Fair Management of Congested Departure
  Operations and Benefit Analysis

abstract:
  Due to the stochastic nature of departure operations, working at full
capacity makes major US airports very sensitive to uncertainties. Consequently,
airport ground operations face critically congested taxiways and long runway
queues. In this report, we show how improved management of departure operations
from the ready-to-push-back time to the wheels-off time can potentially yield
significant benefits to airlines and air traffic services. We develop a
Collaborative Virtual Queue to enable better optimization capabilities during
congested situations while taking into account the laissez-faire competitive
environment. Results are evaluated using a departure system model, validated
using current statistics and previous studies. First, the Collaborative Virtual
Queue enables keeping aircraft away from runway queues, which increases
wheels-off time predictability. Second, holding aircraft enables last-minute
intra-airline flight switching. This creates new optimization capabilities for
airlines i.e. it gives airlines the flexibility to prioritize their flight
sequence in real-time. These capabilities are illustrated by the trade-off
between minimizing the average passenger waiting time and minimizing the level
of unfairness between aircraft of the same airline. For instance, airlines
could choose to decrease by up to 15% their average passenger waiting time by
prioritizing heavy planes over small planes when the taxiway system is
congested.


title: Magnetic Order of the Iron Spins in NdOFeAs

abstract:
  Polarized and unpolarized neutron diffraction measurements have been carried
out to investigate the iron magnetic order in undoped NdOFeAs.
Antiferromagnetic order is observed below 141(6) K, which is in close proximity
to the structural distortion observed in this material. The magnetic structure
consists of chains of parallel spins that are arranged antiparallel between
chains, which is the same in-plane spin arrangement as observed in all the
other iron oxypnictide materials. Nearest-neighbor spins along the c-axis are
antiparallel like LaOFeAs. The ordered moment is 0.25(7) muB, which is the
smallest moment found so far in these systems.


title:
The Triple Higgs Boson Self-Coupling at Future Linear e+e- Colliders
  Energies: ILC and CLIC

abstract:
  We analyzed the triple Higgs boson self-coupling at future $e^{+}e^{-}$
colliders energies, with the reactions $e^{+}e^{-}\to b \bar b HH, t \bar t
HH$. We evaluate the total cross-sections for both $b\bar bHH$ and $t\bar tHH$,
and calculate the total number of events considering the complete set of
Feynman diagrams at tree-level. We vary the triple coupling
$\kappa\lambda_{3H}$ within the range $\kappa=-1$ and +2. The numerical
computation is done for the energies expected to be available at a possible
Future Linear $e^{+}e^{-}$ Collider with a center-of-mass energy $800, 1000,
1500$ $GeV$ and a luminosity 1000 $fb^{-1}$. Our analysis is also extended to a
center-of-mass energy 3 $TeV$ and luminosities of 1000 $fb^{-1}$ and 5000
$fb^{-1}$. We found that for the process $e^{+}e^{-}\to b \bar b HH$, the
complete calculation differs only by 3% from the approximate calculation
$e^{+}e^{-}\to ZHH(Z\to b\bar b)$, while for the process $e^{+}e^{-}\to t \bar
tHH$, the expected number of events, considering the decay products of both $t$
and $H$, is not enough to obtain an accurate determination of the triple Higgs
boson self-coupling.


title: Dynamics and structure of an aging binary colloidal glass

abstract:
  We study aging in a colloidal suspension consisting of micron-sized particles
in a liquid. This system is made glassy by increasing the particle
concentration. We observe samples composed of particles of two sizes, with a
size ratio of 1:2.1 and a volume fraction ratio 1:6, using fast laser scanning
confocal microscopy. This technique yields real-time, three-dimensional movies
deep inside the colloidal glass. Specifically, we look at how the size, motion
and structural organization of the particles relate to the overall aging of the
glass. Particles move in spatially heterogeneous cooperative groups. These
mobile regions tend to be richer in small particles, and these small particles
facilitate the motion of nearby particles of both sizes.


title: Phenomenological loop quantum geometry of the Schwarzschild black hole

abstract:
  The interior of a Schwarzschild black hole is investigated at the level of
phenomenological dynamics with the discreteness corrections of loop quantum
geometry implemented in two different improved quantization schemes. In one
scheme, the classical black hole singularity is resolved by the quantum bounce,
which bridges the black hole interior with a white hole interior. In the other
scheme, the classical singularity is resolved and the event horizon is also
diffused by the quantum bounce. Jumping over the quantum bounce, the black hole
gives birth to a baby black hole with a much smaller mass. This lineage
continues as each classical black hole brings forth its own descendant in the
consecutive classical cycle, giving the whole extended spacetime fractal
structure, until the solution eventually descends into deep Planck regime,
signaling a breakdown of the semiclassical description. The issues of scaling
symmetry and no-hair theorem are also discussed.


title: Ergodic billiards that are not quantum unique ergodic

abstract:
  Partially rectangular domains are compact two-dimensional Riemannian
manifolds $X$, either closed or with boundary, that contain a flat rectangle or
cylinder. In this paper we are interested in partially rectangular domains with
ergodic billiard flow; examples are the Bunimovich stadium, the Sinai billiard
or Donnelly surfaces.
  We consider a one-parameter family $X_t$ of such domains parametrized by the
aspect ratio $t$ of their rectangular part. There is convincing theoretical and
numerical evidence that the Laplacian on $X_t$ with Dirichlet or Neumann
boundary conditions is not quantum unique ergodic (QUE). We prove that this is
true for all $t \in [1,2]$ excluding, possibly, a set of Lebesgue measure zero.
This yields the first examples of ergodic billiard systems proven to be
non-QUE.


title:
Intense Terahertz Laser Fields Induced and Manipulated Pseudospin
  Polarization in Graphene

abstract:
  We investigate the pseudospin-dependent density-energy relation (whose
differential with respect to energy is density of states) of a monolayer
graphene under intense terahertz laser field by exactly solving the
time-dependent Schr\"{o}dinger equation with help of Floquet's theorem. We find
that psedospin polarization can be induced by a circular polarized terahertz
laser field. The psedospin polarization in K and K$^{\prime}$ valleys can be
exactly opposite sign when the electron densities in these two calleys are
equivalent. Further more, we find that the psedospin polarization can be
manipulated by the strength, frequency, and especially the polarization
orientation of the field.


title: Experimental quantum computing without entanglement

abstract:
  Entanglement is widely believed to lie at the heart of the advantages offered
by a quantum computer. This belief is supported by the discovery that a
noiseless (pure) state quantum computer must generate a large amount of
entanglement in order to offer any speed up over a classical computer. However,
deterministic quantum computation with one pure qubit (DQC1), which employs
noisy (mixed) states, is an efficient model that generates at most a marginal
amount of entanglement. Although this model cannot implement any arbitrary
algorithm it can efficiently solve a range of problems of significant
importance to the scientific community. Here we experimentally implement a
first-order case of a key DQC1 algorithm and explicitly characterise the
non-classical correlations generated. Our results show that while there is no
entanglement the algorithm does give rise to other non-classical correlations,
which we quantify using the quantum discord - a stronger measure of
non-classical correlations that includes entanglement as a subset. Our results
suggest that discord could replace entanglement as a necessary resource for a
quantum computational speed-up. Furthermore, DQC1 is far less resource
intensive than universal quantum computing and our implementation in a scalable
architecture highlights the model as a practical short-term goal.


title: Complete one-loop electroweak corrections to $ZZZ$ production at the ILC

abstract:
  We study the complete ${\cal O}(\alpha_{ew})$ electroweak (EW) corrections to
the production of three $Z^0$-bosons in the the framework of the standard
model(SM) at the ILC. The leading order and the EW next-to-leading order
corrected cross sections are presented, and their dependence on the colliding
energy $\sqrt{s}$ and Higgs-boson mass $m_{H}$ is analyzed. We investigate also
the LO and one-loop EW corrected distributions of the transverse momentum of
final $Z^0$ boson, and the invariant mass of $Z^0Z^0$-pair. Our numerical
results show that the EW one-loop correction generally suppresses the
tree-level cross section, and the relative correction with $m_{H}=120 GeV(150
GeV)$ varies between $-15.8%(-13.9%)$ and $-7.5%(-6.2%)$ when $\sqrt{s}$ goes
up from $350 GeV$ to $1 TeV$.


title: Quantum interference and spin polarization on Rashba double quantum dots

abstract:
  We report on the quantum interference and spin accumulation on double quantum
dots with Rashba spin-orbit coupling and electron-electron interaction, based
on the Keldysh nonequilibrium Green function formalism. It is shown that Rashba
spin-orbit interaction can strongly affect the conductance spectrum. By
gradually increasing the Rashba parameter from zero, Fano resonances in strong
overlap regime continuously evolve to resolve antiresonances. This transition
is ascribed to the phase shift of couplings between molecular states and the
lead due to spin precession. We also show that both bias and Rashba effect
strengthen the induced spin polarization in this device. For particular energy
position, up- and down-spin electron occupation can intersect to form a
crossing point. Spin polarization on different side of this point has opposite
sign in consequence. The magnitude and direction of spin polarization are
therefore controllable by tuning the dot levels and the Rashba parameter
through gates.


title:
Realignment-enhanced coherent anti-Stokes Raman scattering (CARS) and
  three-dimensional imaging in anisotropic fluids

abstract:
  We apply coherent anti-Stokes Raman Scattering (CARS) microscopy to
characterize director structures in liquid crystals.

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


title: Algorithmic Problem Complexity

abstract:
  People solve different problems and know that some of them are simple, some
are complex and some insoluble. The main goal of this work is to develop a
mathematical theory of algorithmic complexity for problems. This theory is
aimed at determination of computer abilities in solving different problems and
estimation of resources that computers need to do this. Here we build the part
of this theory related to static measures of algorithms. At first, we consider
problems for finite words and study algorithmic complexity of such problems,
building optimal complexity measures. Then we consider problems for such
infinite objects as functions and study algorithmic complexity of these
problems, also building optimal complexity measures. In the second part of the
work, complexity of algorithmic problems, such as the halting problem for
Turing machines, is measured by the classes of automata that are necessary to
solve this problem. To classify different problems with respect to their
complexity, inductive Turing machines, which extend possibilities of Turing
machines, are used. A hierarchy of inductive Turing machines generates an
inductive hierarchy of algorithmic problems. Here we specifically consider
algorithmic problems related to Turing machines and inductive Turing machines,
and find a place for these problems in the inductive hierarchy of algorithmic
problems.


title:
Population Uncertainty in Model Ecosystem: Analysis by Stochastic
  Differential Equation

abstract:
  Perturbation experiments are carried out by contact process and its
mean-field version. Here, the mortality rate is increased or decreased
suddenly. It is known that the fluctuation enhancement (FE) occurs after the
perturbation, where FE means a population uncertainty. In the present paper, we
develop a new theory of stochastic differential equation. The agreement between
the theory and the mean-field simulation is almost perfect. This theory enables
us to find much stronger FE than reported previously. We discuss the population
uncertainty in the recovering process of endangered species.


title:
Effect of polydispersity on the relative stability of hard-sphere
  crystals

abstract:
  By extending the nonequilibrium potential refinement algorithm and lattice
switch method to the semigrand ensemble, the semigrand potentials of the fcc
and hcp structures of polydisperse hard-sphere crystals are calculated with the
bias sampling scheme. The result shows that the fcc structure is more stable
than the hcp structure for polydisperse hard-sphere crystals below the terminal
polydispersity.


title:
Pressure Effect on Superconductivity of Iron-based Arsenic-oxide
  ReFeAsO0.85 (Re=Sm and Nd)

abstract:
  Here we report pressure effect on superconducting transition temperature (Tc)
of ReFeAsO0.85 (Re= Sm and Nd) system without fluorine doping. In-situ
measurements under high pressure showed that Tc of the two compounds decrease
monotonously over the pressure range investigated. The pressure coefficients
dTc/dP in SmFeAsO0.85 and Nd FeAsO0.85 were different, revealing the important
influence of the deformation in layers on Tc. Theoretical calculations
suggested that the electron density of states decrease with increasing
pressure, following the same trend of experimental data.


title: Massive Dirac fermions in single-layer graphene

abstract:
  Motivated by the results of recent photoemission and tunneling studies, we
discuss potential many-body sources of a finite gap in the Dirac fermion
spectrum of graphene. Specifically, we focus on the putative Peierls- and
Cooper-like pairing instabilities which can be driven by sufficiently strong
Coulomb and electron-phonon interactions, respectively. Our results compare
favorably with the available experimental and Monte Carlo data.


title:
A noncommutative de Finetti theorem: Invariance under quantum
  permutations is equivalent to freeness with amalgamation

abstract:
  We show that the classical de Finetti theorem has a canonical noncommutative
counterpart if we strengthen `exchangeability' (i.e., invariance of the joint
distribution of the random variables under the action of the permutation group)
to invariance under the action of the quantum permutation group. More
precisely, for an infinite sequence of noncommutative random variables, we
prove that invariance of their joint distribution under quantum permutations is
equivalent to the fact that the random variables are identically distributed
and free with respect to the conditional expectation onto their tail algebra.