title: Stellar spindown: From the ONC to the Sun

abstract:
  Rotation is a key parameter in the evolution of stars. From 1 Myr (the age of
the ONC) to 4.5 Gyr (the age of the Sun), solar-like stars lose about 1-2
orders of specific angular momentum. The main agents for this rotational
braking are believed to be star-disk interaction and magnetically powered
stellar winds. Over the last decade, the observational fundament to probe the
stellar spindown has dramatically improved. Significant progress has been made
in exploring the underlying physical causes of the rotational braking.
Parameterized models combining the effects of star-disk interaction, winds, and
pre-main sequence contraction are able to reproduce the main features of the
rotational data for stars spanning more than 3 orders of magnitude in age. This
has allowed us to constrain stellar ages based on the rotation rates
('gyrochronology'). One main challenge for future work is to extend this type
of analysis to the substellar mass range, where the rotational database is
still sparse. More theoretical and observational work is required to explore
the physics of the braking processes, aiming to explain rotational evolution
from first principles. In this review for Cool Stars 15, I will summarize the
status quo and the recent developments in the field.


title:
Spherical grand-canonical minority games with and without score
  discounting

abstract:
  We present a spherical version of the grand-canonical minority game (GCMG),
and solve its dynamics in the stationary state. The model displays several
types of transitions between multiple ergodic phases and one non-ergodic phase.
We derive analytical solutions, including exact expressions for the volatility,
throughout all ergodic phases, and compute the phase behaviour of the system.
In contrast to conventional GCMGs, where the introduction of memory-loss
precludes analytical approaches, the spherical model can be solved also when
exponential discounting is taken into account. For the case of homogeneous
incentives to trade epsilon and memory loss rates rho, an efficient phase is
found only if rho=epsilon=0. Allowing for heterogeneous memory-loss rates we
find that efficiency can be achieved as long as there is any finite fraction of
agents which is not subject to memory loss.


title: Existence theorems in linear chaos

abstract:
  Chaotic linear dynamics deals primarily with various topological ergodic
properties of semigroups of continuous linear operators acting on a topological
vector space. We treat questions of characterizing which of the spaces from a
given class support a semigroup of prescribed shape satisfying a given
topological ergodic property.
  In particular, we characterize countable inductive limits of separable Banach
spaces that admit a hypercyclic operator, show that there is a non-mixing
hypercyclic operator on a separable infinite dimensional complex Fr\'echet
space $X$ if and only if $X$ is non-isomorphic to the space $\omega$ of all
sequences with coordinatewise convergence topology. It is also shown for any
$k\in\N$, any separable infinite dimensional Fr\'echet space $X$ non-isomorphic
to $\omega$ admits a mixing uniformly continuous group $\{T_t\}_{t\in C^n}$ of
continuous linear operators and that there is no supercyclic strongly
continuous operator semigroup $\{T_t\}_{t\geq 0}$ on $\omega$. We specify a
wide class of Fr\'echet spaces $X$, including all infinite dimensional Banach
spaces with separable dual, such that there is a hypercyclic operator $T$ on
$X$ for which the dual operator $T'$ is also hypercyclic. An extension of the
Salas theorem on hypercyclicity of a perturbation of the identity by adding a
backward weighted shift is presented and its various applications are outlined.


title: (medium-modified) Fragmentation Functions

abstract:
  In this short review paper, we discuss some of the recent advances in the
field of parton fragmentation processes into hadrons as well as their possible
modifications in QCD media. Hadron production data in e+e-, deep inelastic
scattering and hadronic collisions are presented, together with global analyses
of fragmentation functions into light and heavy hadrons and developments on
parton fragmentation in perturbative QCD at small momentum fraction. Motivated
by the recent RHIC data indicating a significant suppression of large-pT hadron
production in heavy-ion collisions, several recent attempts to model
medium-modified fragmentation, e.g. by solving "medium" evolution equations or
through Monte Carlo studies, have been proposed and are discussed in detail.
Finally we mention the possibility to extract medium-modified fragmentation
functions using photon-hadron correlations.


title: Measurement of polarisation transfer in hyperon photoproduction at MAMI

abstract:
  The photoproduction of K+ mesons is an important challenge to recent QCD
based chiral perturbation theories in the strange quark sector and is an
important constraint on the nucleon excitation spectrum. We present preliminary
data from a new high precision measurement using the Crystal Ball detector. The
measurement pioneers a new technique for tagging strangeness using detailed
cluster analysis in segmented calorimeters which has potential wider
application at present and future hadron physics facilities.


title: Duality covariant quantum field theory on noncommutative Minkowski space

abstract:
  We prove that a scalar quantum field theory defined on noncommutative
Minkowski spacetime with noncommuting momentum coordinates is covariant with
respect to the UV/IR duality which exchanges coordinates and momenta. The proof
is based on suitable resonance expansions of charged noncommutative scalar
fields in a background electric field, which yields an effective description of
the field theory in terms of a coupled complex two-matrix model. The two
independent matrix degrees of freedom ensure unitarity and manifest
CT-invariance of the field theory. The formalism describes an analytic
continuation of the renormalizable Grosse-Wulkenhaar models to Minkowski
signature.


title: On the classification of fake lens spaces

abstract:
  In the first part of the paper we present a classification of fake lens
spaces of dimension >= 5 whose fundamental group is the cyclic group of order N
>= 2. The classification uses and extends the results of Wall and others in the
case N = 2 and N odd and the results of the authors of the present paper in the
case N a power of 2.
  In the second part we study the suspension map between the simple structure
sets of lens spaces of different dimensions. As an application we obtain an
inductive geometric description of the torsion invariants of fake lens spaces.


title:
Construction of Near-Optimum Burst Erasure Correcting Low-Density
  Parity-Check Codes

abstract:
  In this paper, a simple, general-purpose and effective tool for the design of
low-density parity-check (LDPC) codes for iterative correction of bursts of
erasures is presented. The design method consists in starting from the
parity-check matrix of an LDPC code and developing an optimized parity-check
matrix, with the same performance on the memory-less erasure channel, and
suitable also for the iterative correction of single bursts of erasures. The
parity-check matrix optimization is performed by an algorithm called pivot
searching and swapping (PSS) algorithm, which executes permutations of
carefully chosen columns of the parity-check matrix, after a local analysis of
particular variable nodes called stopping set pivots. This algorithm can be in
principle applied to any LDPC code. If the input parity-check matrix is
designed for achieving good performance on the memory-less erasure channel,
then the code obtained after the application of the PSS algorithm provides good
joint correction of independent erasures and single erasure bursts. Numerical
results are provided in order to show the effectiveness of the PSS algorithm
when applied to different categories of LDPC codes.


title:
Dynamical evolution and spectral characteristics of the stellar group
  Mamajek 2

abstract:
  The dynamical evolution of the recently detected stellar group Mamajek 2 is
studied by means of its past 3D orbit. The past orbits of the open clusters NGC
2516 and $\alpha$ Persei, belonging to the so-called "Local Association", were
also computed in order to check for a possible common past dynamical evolution
of these systems. To complete the data of the Mamajek 2 small group, we have
obtained high resolution FEROS spectra to measure the radial and also the
projected rotational velocities of its members; an estimate of its metallicity
was obtained as well. Two exceptionally low rotating A-type stars turned out to
be a strong magnetic Ap star in one case, and a normal A0 star with near-solar
metallicity in the other. The dynamical results showed that NGC 2516 and
Mamajek 2 may have had a common origin at the age of 135 $\pm$ 5 Myr. This
dynamical age confirms the individual ages of 140 Myr for NGC 2516 and 120
$\pm$ 25 Myr for Mamajek 2 obtained independently by photometric methods. Both
these groups appear to have the same solar metallicity giving support to a
common birth scenario. The dynamical approach is showing that some bound open
clusters can form in a coeval fashion with unbound stellar groups or with
associations.


title:
Une grammaire formelle du cr\'eole martiniquais pour la g\'en\'eration
  automatique

abstract:
  In this article, some first elements of a computational modelling of the
grammar of the Martiniquese French Creole dialect are presented. The sources of
inspiration for the modelling is the functional description given by Damoiseau
(1984), and Pinalie's & Bernabe's (1999) grammar manual. Based on earlier works
in text generation (Vaillant, 1997), a unification grammar formalism, namely
Tree Adjoining Grammars (TAG), and a modelling of lexical functional categories
based on syntactic and semantic properties, are used to implement a grammar of
Martiniquese Creole which is used in a prototype of text generation system. One
of the main applications of the system could be its use as a tool software
supporting the task of learning Creole as a second language. -- Nous
pr\'esenterons dans cette communication les premiers travaux de mod\'elisation
informatique d'une grammaire de la langue cr\'eole martiniquaise, en nous
inspirant des descriptions fonctionnelles de Damoiseau (1984) ainsi que du
manuel de Pinalie & Bernab\'e (1999). Prenant appui sur des travaux
ant\'erieurs en g\'en\'eration de texte (Vaillant, 1997), nous utilisons un
formalisme de grammaires d'unification, les grammaires d'adjonction d'arbres
(TAG d'apr\`es l'acronyme anglais), ainsi qu'une mod\'elisation de cat\'egories
lexicales fonctionnelles \`a base syntaxico-s\'emantique, pour mettre en oeuvre
une grammaire du cr\'eole martiniquais utilisable dans une maquette de
syst\`eme de g\'en\'eration automatique. L'un des int\'er\^ets principaux de ce
syst\`eme pourrait \^etre son utilisation comme logiciel outil pour l'aide \`a
l'apprentissage du cr\'eole en tant que langue seconde.


title:
Perspectives on Heavy Flavour Production and Spectroscopy Studies at the
  LHC

abstract:
  In this note we discuss prospects of analyses at the ATLAS and CMS
experiments that are related to the production of heavy flavour quarks. Trigger
strategies are summarized and a selection of studies is presented. These
include quarkonium production studies such as the differential transverse
momentum cross section measurement and polarization studies, as well as
reconstruction of excited quarkonium states. Furthermore inclusive b quark
production is discussed.


title: Short note on the perturbation of operators with dyadic products

abstract:
  In this paper we use abstract vector spaces and their duals without any
canonical basis. Some of our results can be extended to infinite dimensional
vector spaces too, but here we consider only finite dimensional spaces. We
focus on a general perturbation problem. Assume that $B:V\to V$ is a linear
operator, which is perturbated to $B'=B+Q$. We examine the question how the
determinant and the inverse change, because of this perturbation. In our
approach the operator $Q$ is given as a sum of dyadic products
$Q=\sum_{i=1}^{k}v_{i}\otimes p_{i}$, where $v_{i}\in V$ and $p_{i}\in V^{*}$.
In this paper we derive an $m$-th order ($m\in\mathbb{N}$) approximation
formula for $\det B'$ and $(B')^{-1}$, which gives the exact result if $m\geq
k$.


title: Duality and hidden symmetries in interacting particle systems

abstract:
  In the context of Markov processes, both in discrete and continuous setting,
we show a general relation between duality functions and symmetries of the
generator. If the generator can be written in the form of a Hamiltonian of a
quantum spin system, then the "hidden" symmetries are easily derived. We
illustrate our approach in processes of symmetric exclusion type, in which the
symmetry is of SU(2) type, as well as for the Kipnis-Marchioro-Presutti (KMP)
model for which we unveil its SU(1,1) symmetry. The KMP model is in turn an
instantaneous thermalization limit of the energy process associated to a large
family of models of interacting diffusions, which we call Brownian energy
process (BEP) and which all possess the SU(1,1) symmetry. We treat in details
the case where the system is in contact with reservoirs and the dual process
becomes absorbing.

categories: math-ph cond-mat.stat-mech math.MP math.PR


title:
Elliptic recurrence representation of the N=1 superconformal blocks in
  the Ramond sector

abstract:
  The structure of the 4-point N=1 super-conformal blocks in the Ramond sector
is analyzed. The elliptic recursion relations for these blocks are derived.


title: Nonzero angular momentum pairing correlation in shell model

abstract:
  A simple approximation to shell model is proposed in which the low energy
excitation spectra corresponds to the identical nucleons occupying the same
single particle states where they preferred to form pairs for the ground
states. We call this approximation as nonzero angular momentum pairing shell
model. It not only reduces the dimensionality of the shell model but also
matches the number of low energy levels in experimental spectra for few cases
where exact shell model predicts many more states. The special focus has been
done to consider the realistic interaction derived from free nucleon-nucleon
scattering data to cope with the experimental spectra. The proposed
approximation to shell model has been applied to calculate the energy spectra
of O18 and Ni58 nuclei where only two neutrons occupy the valence states
outside the core. When compared with the experimental data, the results are
found to be encouraging. It is expected that results will be more pronounced if
the even-even nuclei with higher number of valence nucleons are considered.


title:
Fast detector of the ellipticity of infrared and terahertz radiation
  based on HgTe quantum well structures

abstract:
  We report a fast, room temperature detection scheme for the polarization
ellipticity of laser radiation, with a bandwidth that stretches from the
infrared to the terahertz range. The device consists of two elements, one in
front of the other, that detect the polarization ellipticity and the azimuthal
angle of the ellipse. The elements respectively utilise the circular
photogalvanic effect in a narrow gap semiconductor and the linear photogalvanic
effect in a bulk piezoelectric semiconductor. For the former we characterized
both a HgTe quantum well and bulk Te, and for the latter, bulk GaAs. In
contrast with optical methods our device is an easy to handle all-electric
approach, which we demonstrated by applying a large number of different lasers
from low power, continuous wave systems to high power, pulsed sources.


title:
Espaces de fonctions \`a moyenne fractionnaire int\'egrable sur les
  groupes localement compacts

abstract:
  Let $G$ be a locally compact group which is $\sigma $-compact, endowed with a
left Haar measure $\lambda .$ Denote by $e$ the unit element of $G$, and by $B$
an open relatively compact and symmetric neighbourhood of $e$. For every $(p,q)
$ belonging to $[ 1 ; +\infty ] ^{2}$, we give an equivalent and a priori more
manageable definition of the Banach space $L_{(q,p)}^{\pi}(G),$ defined by R.
C. Busby and H. A. Smith in \cite% {1}. In the case $G$ is a group of
homogeneous type, we look at the subspaces $(L^{q},L^{p}) ^{\alpha}(G)$ of the
space $% L_{(q,p)}^{\pi}(G)$. Theses subspaces are extensions to non abelian
groups of the spaces of functions with integrable mean, defined by I. Fofana in
\cite{2}. Finally we show that $L^{\alpha ,+\infty}(G)$ is a complex subspace
of $(L^{q},L^{p}) ^{\alpha}(G)$.


title:
A Layered Grammar Model: Using Tree-Adjoining Grammars to Build a Common
  Syntactic Kernel for Related Dialects

abstract:
  This article describes the design of a common syntactic description for the
core grammar of a group of related dialects. The common description does not
rely on an abstract sub-linguistic structure like a metagrammar: it consists in
a single FS-LTAG where the actual specific language is included as one of the
attributes in the set of attribute types defined for the features. When the
lang attribute is instantiated, the selected subset of the grammar is
equivalent to the grammar of one dialect. When it is not, we have a model of a
hybrid multidialectal linguistic system. This principle is used for a group of
creole languages of the West-Atlantic area, namely the French-based Creoles of
Haiti, Guadeloupe, Martinique and French Guiana.


title:
Redshifted emission lines and radiative recombination continuum from the
  Wolf-Rayet binary theta Muscae: evidence for a triplet system?

abstract:
  We present XMM-Newton observations of the WC binary Theta Muscae (WR 48), the
second brightest Wolf-Rayet binary in optical wavelengths. The system consists
of a short-period (19.1375 days) WC5/WC6 + O6/O7V binary and possibly has an
additional O supergiant companion (O9.5/B0Iab) which is optically identified at
a separation of ~46 mas. Strong emission lines from highly ionized ions of C,
O, Ne, Mg, Si, S, Ar, Ca and Fe are detected. The spectra are fitted by a
multi-temperature thin-thermal plasma model with an interstellar absorption N_H
= 2--3*10**21 cm**-2. Lack of nitrogen line indicates that the abundance of
carbon is at least an order of magnitude larger than that of nitrogen. A
Doppler shift of ~630 km/s is detected for the OVIII line, while similar shifts
are obtained from the other lines. The reddening strongly suggests that the
emission lines originated from the wind-wind shock zone, where the average
velocity is ~600 km/s. The red-shift motion is inconsistent with a scenario in
which the X-rays originate from the wind-wind collision zone in the
short-period binary, and would be evidence supporting the widely separated O
supergiant as a companion. This may make up the collision zone be lying behind
the short-period binary. In addition to the emission lines, we also detected
the RRC (radiative recombination continuum) structure from carbon around 0.49
keV. This implies the existence of additional cooler plasma.


title: Flavour Violation in GMSB Scenarios: Constraints and Phenomenology

abstract:
  We present an extensive analysis of low-energy, electroweak precision, and
cosmological constraints in the Minimal Supersymmetric Standard Model (MSSM)
with Gauge-Mediated Supersymmetry Breaking (GMSB) and including the possibility
of Non-Minimal Flavour Violation (NMFV). Using detailed scans over the
parameter space, we show how NMFV allows to relax the stringent constraints
excluding large parts of the minimal GMSB. We define benchmark scenarios and
present numerical predictions for various sparticle production cross sections
at the LHC.


title: On the distance and reddening of the starburst galaxy IC10

abstract:
  We present deep and accurate optical photometry of the Local Group starburst
galaxy IC10. The photometry is based on two sets of images collected with the
Advanced Camera for Surveys and with the Wide Field Planetary Camera 2 on board
the Hubble Space Telescope. We provide new estimates of the Red Giant Branch
tip (TRGB) magnitude, m_{F814W}^{TRGB}=21.90+-0.03, and of the reddening,
E(B-V)=0.78+-0.06, using field stars in the Small Magellanic Cloud (SMC) as a
reference. Adopting the SMC and two globulars, Omega Centauri and 47 Tucanae,
as references we estimate the distance modulus to IC10: independent
calibrations give weighted average distances of mu=24.51+-0.08 (TRGB) and
mu=24.56+-0.08 (RR Lyrae). We also provide a new theoretical calibration for
the TRGB luminosity, and using these predictions we find a very similar
distance to IC10 (mu~24.60+-0.15). These results suggest that IC10 is a likely
member of the M31 subgroup.


title:
Statistics of the gravitational force in various dimensions of space:
  from Gaussian to Levy laws

abstract:
  We discuss the distribution of the gravitational force created by a
Poissonian distribution of field sources (stars, galaxies,...) in different
dimensions of space d. In d=3, it is given by a Levy law called the Holtsmark
distribution. It presents an algebraic tail for large fluctuations due to the
contribution of the nearest neighbor. In d=2, it is given by a marginal
Gaussian distribution intermediate between Gaussian and Levy laws. In d=1, it
is exactly given by the Bernouilli distribution (for any particle number N)
which becomes Gaussian for N>>1. Therefore, the dimension d=2 is critical
regarding the statistics of the gravitational force. We generalize these
results for inhomogeneous systems with arbitrary power-law density profile and
arbitrary power-law force in a d-dimensional universe.


title:
Analyse spectrale des textes: d\'etection automatique des fronti\`eres
  de langue et de discours

abstract:
  We propose a theoretical framework within which information on the vocabulary
of a given corpus can be inferred on the basis of statistical information
gathered on that corpus. Inferences can be made on the categories of the words
in the vocabulary, and on their syntactical properties within particular
languages. Based on the same statistical data, it is possible to build matrices
of syntagmatic similarity (bigram transition matrices) or paradigmatic
similarity (probability for any pair of words to share common contexts). When
clustered with respect to their syntagmatic similarity, words tend to group
into sublanguage vocabularies, and when clustered with respect to their
paradigmatic similarity, into syntactic or semantic classes. Experiments have
explored the first of these two possibilities. Their results are interpreted in
the frame of a Markov chain modelling of the corpus' generative processe(s): we
show that the results of a spectral analysis of the transition matrix can be
interpreted as probability distributions of words within clusters. This method
yields a soft clustering of the vocabulary into sublanguages which contribute
to the generation of heterogeneous corpora. As an application, we show how
multilingual texts can be visually segmented into linguistically homogeneous
segments. Our method is specifically useful in the case of related languages
which happened to be mixed in corpora.


title: Physical Properties of Very Powerful FRII Radio Galaxies

abstract:
  We estimate ages and physical properties of powerful radio galaxies. An
analysis of new multi-wavelength VLA observations of eleven very powerful
classical double (FRIIb) radio galaxies with redshifts between 0.4 and 1.3 is
presented. We estimate ages and velocities for each side of each source. The
eleven new sources are combined with previously studied samples and the
characteristics of the full sample of 31 sources are studied; the full sample
includes sources with redshifts between 0.056 and 1.79, and core-hot spot sizes
of about 30 to 400 kpc. The velocities are independent of core-hotspot
separation, suggesting the rate of growth of a given source is roughly constant
over the source lifetime. We combine the rate of growth, width, and pressure of
a source to study the beam power, lifetime, energy, and ambient gas density
using standard methods previously applied to smaller samples. Typical beam
powers are in the range from 1E44 to 1E46 erg/s; we show that this quantity is
insensitive to assumptions regarding minimum energy conditions. The beam powers
are independent of core-hotspot separation suggesting that the beam power of a
given source is roughly constant over the source lifetime. Typical total source
lifetimes are found to be about a few E6 to E7 years, and typical total outflow
energies (E/c^2) are found to be about 5(E5 - E6) solar masses. Ambient gas
densities are found to decrease with increasing core-hotspot distance, but have
no redshift dependence. Overall, the results obtained with the sample of 31
sources studied here are consistent with those obtained earlier with smaller
samples.


title: Exceptional N=6 and N=2 AdS_4 Supergravity, and Zero-Center Modules

abstract:
  We study the gauging of the orthosymplectic algebras OSp(6|4)xSO(2) and its
"dual" OSp(2|4)x SO(6), both based on supergravities with the same exceptional
coset SO*(12)/U(6), and gauge group SO(6)xSO(2). The two dual theories are
obtained by two different truncations of gauged N=8 AdS_4 supergravity. We
explicitly study the gauge sector of the two dual theories with the most
general group allowed by supersymmetry. In the ungauged (super-Poincar\'e) case
they exhibit the same (large) black-hole attractor solutions with dual
relations between the 1/N-BPS and non-BPS configurations. The N=6 gravity
multiplet has also the exceptional property to be a {\em zero-center module} of
OSp(6|4), as it is the case for superconformal Yang--Mills theory in four
dimensions based on SU(2,2|n) (PSU(2,2|4) for n=4) or OSp(n|4).


title: Scale free effects in world currency exchange network

abstract:
  A large collection of daily time series for 60 world currencies' exchange
rates is considered. The correlation matrices are calculated and the
corresponding Minimal Spanning Tree (MST) graphs are constructed for each of
those currencies used as reference for the remaining ones. It is shown that
multiplicity of the MST graphs' nodes to a good approximation develops a power
like, scale free distribution with the scaling exponent similar as for several
other complex systems studied so far. Furthermore, quantitative arguments in
favor of the hierarchical organization of the world currency exchange network
are provided by relating the structure of the above MST graphs and their
scaling exponents to those that are derived from an exactly solvable
hierarchical network model. A special status of the USD during the period
considered can be attributed to some departures of the MST features, when this
currency (or some other tied to it) is used as reference, from characteristics
typical to such a hierarchical clustering of nodes towards those that
correspond to the random graphs. Even though in general the basic structure of
the MST is robust with respect to changing the reference currency some trace of
a systematic transition from somewhat dispersed -- like the USD case -- towards
more compact MST topology can be observed when correlations increase.


title: Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)

abstract:
  This document presents the technical layout and the envisaged performance of
the Electromagnetic Calorimeter (EMC) for the PANDA target spectrometer. The
EMC has been designed to meet the physics goals of the PANDA experiment, which
is being developed for the Facility for Antiproton and Ion Research (FAIR) at
Darmstadt, Germany. The performance figures are based on extensive prototype
tests and radiation hardness studies. The document shows that the EMC is ready
for construction up to the front-end electronics interface.


title: Dispersive Approach to Abelian Axial Anomaly and $\eta-\eta'$ Mixing

abstract:
  We investigate what can be learnt about the $\eta$ -$\eta'$ mixing by means
of dispersive representation of axial anomaly. We show that our method leads to
the strong bounds for the $\eta-\eta'$ mixing angle:
  $\theta = -15.3^o \pm 1^o$. Moreover, our result manifests also a dramatic
dependence of the width $\Gamma_{\eta\to 2\gamma}$ on the mixing angle
$\theta$.
  This property explains how the relatively small mixing strongly effects the
decay width.


title: Influence of metallic nanoparticles on upconversion processes

abstract:
  It is well known that Raman scattering and fluorescence can be enhanced by
the presence of metallic nanoparticles. Here, we derive simple equations to
analyse the influence of metallic nanoparticles on upconversion processes such
as non-radiative energy transfer or excited state absorption. We compare the
resulting expressions with the more familiar Raman and fluorescence cases, and
find significant differences. We use numerical simulations to calculate the
upconverted signal enhancement achievable by means of metallic spheres of
different radii, and find particles of 100-400nm radius at infrared frequencies
to be favorable. We also discuss the considerable challenges involved in using
metallic particles to enhance upconversion for solar energy.


title:
Identification and Rejection of Fake Reconstructed Jets From a
  Fluctuating Heavy Ion Background in ATLAS

abstract:
  Full jet reconstruction in relativistic heavy ion collisions provides new and
unique insights to the physics of parton energy loss. Because of the large
underlying event multiplicity in $A+A$ collisions, random and correlated
fluctuations in the background can result in the reconstruction of fake jets.
These fake jets must be identified and rejected to obtain the purest jet sample
possible. A large but reducible fake rate of jets reconstructed using an
iterative cone algorithm on HIJING events is observed. The absolute rate of
fake jets exceeds the binary-scaled p+p jet rate below 50 GeV and is not
negligible until 100 GeV. The variable $\Sigma j_{T}$, the sum of the jet
constituent's $E_{T}$ perpendicular to the jet axis, is introduced to identify
and reject fake jets at by a factor of 100 making it negligible. This variable
is shown to not strongly depend on jet energy profiles modified by energy loss.
By studying azimuthal correlations of reconstructed di-jets, the fake jet rate
can be evaluated in data.


title: Decay constants from twisted mass QCD

abstract:
  We present results for chiral extrapolations of the mass and decay constants
of the rho meson. The data sets used are the nf=2 unquenched gauge
configurations generated with twisted mass fermions by the European Twisted
Mass Collaboration. We describe a calculation of three decay constants in
charmonium and explain why they are required.


title: Complexity of links in 3-manifolds

abstract:
  We introduce a natural-valued complexity c(X) for pairs X=(M,L), where M is a
closed orientable 3-manifold and L is a link contained in M. The definition
employs simple spines, but for well-behaved X's we show that c(X) equals the
minimal number of tetrahedra in a triangulation of M containing L in its
1-skeleton. Slightly adapting Matveev's recent theory of roots for graphs, we
carefully analyze the behaviour of c under connected sum away from and along
the link. We show in particular that c is almost always additive, describing in
detail the circumstances under which it is not. To do so we introduce a certain
(0,2)-root for a pair X, we show that it is well-defined, and we prove that X
has the same complexity as its (0,2)-root. We then consider, for links in the
3-sphere, the relations of c with the crossing number and with the hyperbolic
volume of the exterior, establishing various upper and lower bounds. We also
specialize our analysis to certain infinite families of links, providing rather
accurate asymptotic estimates.


title: On unifying the description of meson and baryon properties

abstract:
  A Poincare' covariant Faddeev equation is presented, which enables the
simultaneous prediction of meson and baryon observables using the leading-order
in a truncation of the Dyson-Schwinger equations that can systematically be
improved. The solution describes a nucleon's dressed-quark core. The evolution
of the nucleon mass with current-quark mass is discussed. A nucleon-photon
current, which can produce nucleon form factors with realistic Q^2-evolution,
is described. Axial-vector diquark correlations lead to a neutron Dirac form
factor that is negative, with r_1^{nu}>r_1^{nd}. The proton electric-magnetic
form factor ratio falls with increasing Q^2.


title: Ecological Complex Systems

abstract:
  Main aim of this topical issue is to report recent advances in noisy
nonequilibrium processes useful to describe the dynamics of ecological systems
and to address the mechanisms of spatio-temporal pattern formation in ecology
both from the experimental and theoretical points of view. This is in order to
understand the dynamical behaviour of ecological complex systems through the
interplay between nonlinearity, noise, random and periodic environmental
interactions. Discovering the microscopic rules and the local interactions
which lead to the emergence of specific global patterns or global dynamical
behaviour and the noises role in the nonlinear dynamics is an important, key
aspect to understand and then to model ecological complex systems.


title:
Noncommutative quantum mechanics: uniqueness of the functional
  description

abstract:
  The generalized Weyl transform of index $\alpha$ is used to implement the
time-slice definition of the phase space path integral yielding the Feynman
kernel in the case of noncommutative quantum mechanics. As expected, this
representation for the Feynman kernel is not unique but labeled by the real
parameter $\alpha$. We succeed in proving that the $\alpha$-dependent
contributions disappear at the limit where the time slice goes to zero. This
proof of consistency turns out to be intricate because the Hamiltonian involves
products of noncommuting operators originating from the non-commutativity. The
antisymmetry of the matrix parameterizing the non-commutativity plays a key
role in the cancelation mechanism of the $\alpha$-dependent terms.


title:
Fabry-Perot Absorption Line Spectroscopy of the Galactic Bar. I.
  Kinematics

abstract:
  We use Fabry-Perot absorption line imaging spectroscopy to measure radial
velocities using the Ca II 8542 line in 3360 stars towards three lines of sight
in the Milky Way's bar: Baade's Window and offset position at (l,b) ~ (+-5.0,
-3.5). This sample includes 2488 bar red clump giants, 339 bar M/K-giants, and
318 disk main sequence stars. We measure the first four moments of the stellar
velocity distribution of the red clump giants, and find it to be symmetric and
flat-topped. We also measure the line-of-sight average velocity and dispersion
of the red clump giants as a function of distance in the bar. We detect stellar
streams at the near and far side of the bar with velocity difference > 30 km/s
at l = +-5, but we do not detect two separate streams in Baade's Window. Our
M-giants kinematics agree well with previous studies, but have dispersions
systematically lower than those of the red clump giants by ~ 10 km/s. For the
disk main sequence stars we measure a velocity dispersion of ~ 45 km/s for all
three lines-of-sight, placing a majority of them in the thin disk within 3.5
kpc of the Sun, associated with the Sagittarius spiral arm. We measure the
equivalent widths of the Ca II 8542 line that can be used to infer
metallicities. We find indications of a metallicity gradient with Galactic
longitude, with greater metallicity in Baade's Window. We find the bulge to be
metal-rich, consistent with some previous studies.


title: Traffic Dynamics of Computer Networks

abstract:
  Two important aspects of the Internet, namely the properties of its topology
and the characteristics of its data traffic, have attracted growing attention
of the physics community. My thesis has considered problems of both aspects.
First I studied the stochastic behavior of TCP, the primary algorithm governing
traffic in the current Internet, in an elementary network scenario consisting
of a standalone infinite-sized buffer and an access link. The effect of the
fast recovery and fast retransmission (FR/FR) algorithms is also considered. I
showed that my model can be extended further to involve the effect of link
propagation delay, characteristic of WAN. I continued my thesis with the
investigation of finite-sized semi-bottleneck buffers, where packets can be
dropped not only at the link, but also at the buffer. I demonstrated that the
behavior of the system depends only on a certain combination of the parameters.
Moreover, an analytic formula was derived that gives the ratio of packet loss
rate at the buffer to the total packet loss rate. This formula makes it
possible to treat buffer-losses as if they were link-losses. Finally, I studied
computer networks from a structural perspective. I demonstrated through fluid
simulations that the distribution of resources, specifically the link
bandwidth, has a serious impact on the global performance of the network. Then
I analyzed the distribution of edge betweenness in a growing scale-free tree
under the condition that a local property, the in-degree of the "younger" node
of an arbitrary edge, is known in order to find an optimum distribution of link
capacity. The derived formula is exact even for finite-sized networks. I also
calculated the conditional expectation of edge betweenness, rescaled for
infinite networks.


title: Quantized mixed tensor space and Schur-Weyl duality

abstract:
  Let $R$ be a commutative ring with one and $q$ an invertible element of $R$.
The (specialized) quantum group ${\mathbf U} = U_q(\mathfrak{gl}_n)$ over $R$
of the general linear group acts on mixed tensor space $V^{\otimes r}\otimes
{V^*}^{\otimes s}$ where $V$ denotes the natural $\mathbf U$-module $R^n$,
$r,s$ are nonnegative integers and $V^*$ is the dual $\mathbf U$-module to $V$.
The image of $\mathbf U$ in $\mathrm{End}_R(V^{\otimes r}\otimes {V^*}^{\otimes
s})$ is called the rational $q$-Schur algebra $S_{q}(n;r,s)$. We construct a
bideterminant basis of $S_{q}(n;r,s)$. There is an action of a $q$-deformation
$\mathfrak{B}_{r,s}^n(q)$ of the walled Brauer algebra on mixed tensor space
centralizing the action of $\mathbf U$. We show that
$\mathrm{End}_{\mathfrak{B}_{r,s}^n(q)}(V^{\otimes r}\otimes {V^*}^{\otimes
s})=S_{q}(n;r,s)$. By \cite{dipperdotystoll} the image of
$\mathfrak{B}_{r,s}^n(q)$ in $\mathrm{End}_R(V^{\otimes r}\otimes
{V^*}^{\otimes s})$ is $\mathrm{End}_{\mathbf U}(V^{\otimes r}\otimes
{V^*}^{\otimes s})$. Thus mixed tensor space as $\mathbf
U$-$\mathfrak{B}_{r,s}^n(q)$-bimodule satisfies Schur-Weyl duality.


title:
Pressure Dependence of the Dynamic Crossover Temperatures in Protein and
  its Hydration Water

abstract:
  Recently we have shown experimental evidence for a fragile-to-strong dynamic
crossover (FSC) phenomenon in hydration water around a globular protein
(lysozyme) at ambient pressure. In this letter we show that when applying
pressure to the protein-water system, the FSC crossover temperatures in
hydration water of lysozyme tracks the similar Widom line emanating from the
existence of a liquid-liquid critical point in a 1-D confined water (in
MCM-41-S). The mean squared displacements (MSD) of hydrogen atoms in lysozyme
and in its hydration water show a sudden change of slopes at the same
characteristic temperature, which decreases with an increasing pressure. These
results taken together give support of the idea that the dynamic crossover (or
so-called glass transition) of the protein is a function of both temperature
and pressure, following the FSC of its hydration water.


title:
The cluster-galaxy cross-spectrum: an additional probe of cosmological
  and halo parameters

abstract:
  There are several wide field galaxy and cluster surveys planned for the
nearest future, e.g. BOSS, WFMOS, ADEPT, Hetdex, SPT, eROSITA. In the simplest
approach one would analyze these independently, thus neglecting the extra
information provided by the cluster-galaxy cross-pairs. In this paper we have
focused on the possible synergy between these surveys by investigating the
amount of information encoded in the cross-pairs. We present a model for the
cluster-galaxy cross-spectrum within the Halo Model framework. To assess the
gain in performance due to inclusion of the cluster-galaxy cross-pairs we carry
out a Fisher matrix analysis for a BOSS-like galaxy redshift survey targeting
luminous red galaxies and a hypothetical mass-limited cluster redshift survey
with a lower mass threshold of 1.7x10^14 M_sun/h over the same volume. On small
scales cluster-galaxy cross-spectrum probes directly density profile of the
halos, instead of the density profile convolved with itself, as is the case for
the galaxy power spectrum. Due to this different behavior, adding information
from the cross-pairs helps to tighten constraints on the halo occupation
distribution. By inclusion of the cross-pairs a factor of ~2 stronger
constraints are obtained for sigma_8, while the improvement for the dark energy
figure-of-merit is somewhat weaker: an increase by a factor of 1.4.


title:
Two-loop QCD correction to differential semi-leptonic b --> u decays in
  the shape-function region

abstract:
  We calculate the two-loop QCD correction to the form factors of on-shell
b-quark decay to an energetic massless quark, which constitutes the last
missing piece required for an O(alpha_s^2) determination of |V_ub| from
inclusive semi-leptonic \bar B --> X_u l nu decays in the shape-function
region.


title:
Quantum corrections to conductivity for semiconductors with various
  structures

abstract:
  We study the magnetic field dependences of the conductivity in heavily doped,
strongly disordered 2D quantum well structures within wide conductivity and
temperature ranges. We show that the exact analytical expression derived in our
previous paper [1], is in better agreement than the existing equation i.e.
Hikami(et.al.,) expression [2,3], with the experimental data even in low
magnetic field for which the diffusion approximation is valid. On the other
hand from theoretical point of view we observe that our equation is also rich
because it establishes a strong relationship between quantum corrections to the
conductivity and the quantum symmetry su_{q}(2). It is shown that the quantum
corrections to the conductivity is the trace of Green function made by a
generator of su_{q}(2)algebra. Using this fact we show that the quantum
corrections to the conductivity can be expressed as a sum of an infinite number
of Feynman diagrams.


title: On positively curved 4-manifolds with S^1-symmetry

abstract:
  It is well-known by the work of Hsiang and Kleiner that every closed oriented
positively curved 4-dimensional manifold with an effective isometric S^1-action
is homeomorphic to S^4 or CP^2. As stated, it is a topological classification.
The primary goal of this paper is to show that it is indeed a diffeomorphism
classification for such 4-dimensional manifolds. The proof of this
diffeomorphism classification also shows an even stronger statement that every
positively curved simply connected 4-manifold with an isometric circle action
admits another smooth circle action which extends to a 2-dimensional torus
action and is equivariantly diffeomorphic to a linear action on S^4 or CP^2.
The main strategy is to analyze all possible topological configurations of
effective circle actions on simply connected 4-manifolds by using the so-called
replacement trick of Pao.


title: The mixed black hole partition function for the STU model

abstract:
  We evaluate the mixed partition function for dyonic BPS black holes using the
recently proposed degeneracy formula for the STU model. The result factorizes
into the OSV mixed partition function times a proportionality factor. The
latter is in agreement with the measure factor that was recently conjectured
for a class of N=2 black holes that contains the STU model.


title:
On Resource Allocation in Fading Multiple Access Channels - An Efficient
  Approximate Projection Approach

abstract:
  We consider the problem of rate and power allocation in a multiple-access
channel. Our objective is to obtain rate and power allocation policies that
maximize a general concave utility function of average transmission rates on
the information theoretic capacity region of the multiple-access channel. Our
policies does not require queue-length information. We consider several
different scenarios. First, we address the utility maximization problem in a
nonfading channel to obtain the optimal operating rates, and present an
iterative gradient projection algorithm that uses approximate projection. By
exploiting the polymatroid structure of the capacity region, we show that the
approximate projection can be implemented in time polynomial in the number of
users. Second, we consider resource allocation in a fading channel. Optimal
rate and power allocation policies are presented for the case that power
control is possible and channel statistics are available. For the case that
transmission power is fixed and channel statistics are unknown, we propose a
greedy rate allocation policy and provide bounds on the performance difference
of this policy and the optimal policy in terms of channel variations and
structure of the utility function. We present numerical results that
demonstrate superior convergence rate performance for the greedy policy
compared to queue-length based policies. In order to reduce the computational
complexity of the greedy policy, we present approximate rate allocation
policies which track the greedy policy within a certain neighborhood that is
characterized in terms of the speed of fading.


title:
Minimal Surfaces in the Three-Dimensional Sphere and Minimal
  Hypersurfaces of Type Number Two

abstract:
  We introduce canonical principal parameters on any strongly regular minimal
surface in the three dimensional sphere and prove that any such a surface is
determined up to a motion by its normal curvature function satisfying the
Sinh-Poisson equation. We obtain a classification theorem for bi-umbilical
hypersurfaces of type number two. We prove that any minimal hypersurface of
type number two with involutive distribution is generated by a minimal surface
in the three-dimensional Euclidean space, or in the three dimensional sphere.
Thus we prove that the theory of minimal hypersurfaces of type number two with
involutive distribution is locally equivalent to the theory of minimal surfaces
in the three dimensional Euclidean space or in the three-dimensional sphere.


title: Multiple magnetic barriers in graphene

abstract:
  We study the behavior of charge carriers in graphene in inhomogeneous
perpendicular magnetic fields. We consider two types of one-dimensional
magnetic profiles, uniform in one direction: a sequence of N magnetic barriers,
and a sequence of alternating magnetic barriers and wells. In both cases, we
compute the transmission coefficient of the magnetic structure by means of the
transfer matrix formalism, and the associated conductance. In the first case
the structure becomes increasingly transparent upon increasing N at fixed total
magnetic flux. In the second case we find strong wave-vector filtering and
resonant effects. We also calculate the band structure of a periodic magnetic
superlattice, and find a wave-vector-dependent gap around zero-energy.


title: Langevin approach to synchronization of hyperchaotic time-delay dynamics

abstract:
  In this paper, we characterize the synchronization phenomenon of hyperchaotic
scalar non-linear delay dynamics in a fully-developed chaos regime. Our results
rely on the observation that, in that regime, the stationary statistical
properties of a class of hyperchaotic attractors can be reproduced with a
linear Langevin equation, defined by replacing the non-linear delay force by a
delta-correlated noise. Therefore, the synchronization phenomenon can be
analytically characterized by a set of coupled Langevin equations. We apply
this formalism to study anticipated synchronization dynamics subject to
external noise fluctuations as well as for characterizing the effects of
parameter mismatch in a hyperchaotic communication scheme. The same procedure
is applied to second order differential delay equations associated to
synchronization in electro-optical devices. In all cases, the departure with
respect to perfect synchronization is measured through a similarity function.
Numerical simulations in discrete maps associated to the hyperchaotic dynamics
support the formalism.


title:
Constant mean curvature tori as stationary solutions to the
  Davey-Stewartson equation

abstract:
  A well known result of Da Rios and Levi-Civita says that a closed planar
curve is elastic if and only if it is stationary under the localized induction
(or smoke ring) equation, where stationary means that the evolution under the
localized induction equation is by rigid motions. We prove an analogous result
for surfaces: an immersion of a torus into the conformal 3-sphere has constant
mean curvature with respect to a space form subgeometry if and only if it is
stationary under the Davey-Stewartson flow.


title: Breakdown of large-N reduction in the quenched Eguchi-Kawai model

abstract:
  We study the validity of the large-N equivalence between four-dimensional
SU(N) lattice gauge theory and its momentum quenched version -- the Quenched
Eguchi-Kawai (QEK) model. We have found strong evidence that this equivalence
does not hold in the weak-coupling regime (and thus in the continuum limit).
This is based on weak-coupling analytic arguments and Monto-Carlo simulations
at intermediate couplings with 20 <= N <= 200. Since detailed expositions of
our arguments, methods and results have already appeared in Phys. Rev.
D78:034507 (2008) and Phys. Rev. D78:074503 (2008), we attempt here to give a
more intuitive explanation of our results. The breakdown of reduction that we
find is due to a dynamically generated correlation between different Euclidean
components of the gauge fields.


title: Entanglement and its facets in condensed matter systems

abstract:
  This thesis poses a selection of recent research of the author in a common
context. It starts with a selected review on research concerning the role
entanglement might play at quantum phase transitions and introduces measures
for entanglement used for this analysis. A selection of results from this
research is given and proposed as evidence for the relevance of multipartite
entanglement in this context. A constructive method for an SLOCC classification
and quantification of multipartite qubit entanglement is outlined and results
for convex roof extensions of the resulting measures are briefly discussed on a
specific example. At the end, a transformation of antilinear expectation values
into linear expectation values is presented which admits an expression of the
aforementioned measures of genuine multipartite entanglement in terms of spin
correlation function, hence making them experimentally accessible.


title: Koszulity of splitting algebras associated with cell complexes

abstract:
  We associate to a good cell decomposition of a manifold M a quadratic algebra
and show that the Koszulity of the algebra implies a restriction on the Euler
characteristic of M. For a two-dimensional manifold M the algebra is Koszul if
and only if the Euler characteristic of M is two.


title: "Fractal Expression" in Chinese Calligraphy

abstract:
  We show that from historical record and mathematic analysis, "fractal
expressions" may have been a conscious pursuit at least one thousand years ago
as an element of beauty in ancient Chinese calligraphy.


title: Chern-Simons-Matter Theory and Mirror Symmetry

abstract:
  In this paper we study supersymmetric Chern-Simons-matter (CSM) theories with
several Higgs branches. Two such theories at small Chern-Simons level are
conjectured to describe the superconformal field theory at the infrared fixed
point of N = 4 QED with N_f = 2, 3. In particular, the mirror symmetry which
exchanges the Coulomb and Higgs branches of N = 4 QED with N_f = 2 is manifest
in the Chern-Simons-matter description. We also study the quantum corrections
to the moduli space of a class of N = 2 CSM theories.


title: SDSSJ092712.65+294344.0: NGC 1275 at z=0.7?

abstract:
  SDSSJ092712.65+294344.0 was identified by the SDSS as a quasar, but has the
unusual property of having two emission line systems offset by 2650 km/s. One
of these contains the usual combination of broad and narrow lines, the other
only narrow lines. In the first paper commenting on this system (Komossa et al.
2008), it was interpreted as a galaxy in which a pair of black holes had
merged, imparting a several thousand km/s recoil to the new, larger black hole.
In two other papers (Bogdanovic, Eracleous & Sigurdsson 2008; Dotti et al.
2008), it was interpreted as a small-separation binary black hole. We propose a
new interpretation: that this system is a more distant analog of NGC1275, a
large and a small galaxy interacting near the center of a rich cluster.


title: Dark Matter Equilibria in Galaxies and Galaxy Systems

abstract:
  [abridged] In the dark matter (DM) halos embedding galaxies and galaxy
systems the `entropy' K = \sigma^2 / \rho^{2/3} (a quantity that combines the
radial velocity dispersion \sigma with the density \rho) is found from
intensive N-body simulations to follow a powerlaw run K ~ r^{\alpha} throughout
the halos' bulk, with \alpha around 1.25. Taking up from phenomenology just
that \alpha ~ const applies, we cut through the rich analytic contents of the
Jeans equation describing the self-gravitating equilibria of the DM; we
specifically focus on computing and discussing a set of novel physical
solutions that we name \alpha-profiles, marked by the entropy slope \alpha
itself, and by the maximal gravitational pull \kappa_crit required for a viable
equilibrium to hold. We then use an advanced semianalytic description for the
cosmological buildup of halos to constrain the values of \alpha to within the
narrow range 1.25-1.29 from galaxies to galaxy systems. Our range of \alpha
applies since the transition time that - both in oursemianalytic description
and in state-of-the-art numerical simulations - separates two development
stages: an early violent collapse that comprises a few major mergers and
enforces dynamical mixing, followed by smoother mass addition through slow
accretion. We also give an accurate analytic representation of the
\alpha-profiles with parameters derived from the Jeans equation. We finally
stress how our findings and predictions as to \alpha and \kappa_crit contribute
to understand hitherto unsolved issues concerning the fundamental structure of
DM halos.


title: Finite size giant magnons in the SU(2) x SU(2) sector of AdS_4 x CP^3

abstract:
  We use the algebraic curve and Luscher's mu-term to calculate the leading
order finite size corrections to the dispersion relation of giant magnons in
the SU(2) x SU(2) sector of AdS_4 x CP^3. We consider a single magnon as well
as one magnon in each SU(2). In addition the algebraic curve computation is
generalized to give the leading order correction for an arbitrary multi-magnon
state in the SU(2) x SU(2) sector.


title:
Resonance contribution to single pion production in neutrino-nucleon
  scattering

abstract:
  Single pion production in neutrino-nucleon scattering is discussed. The
neutrino energies characteristic for T2K project are considered. Two new
parameterizations of $C_5^A$ axial form factor are proposed. Both of them are
obtained in simultaneous fit to ANL and BNL data. One of them (which fits
better to BNL data) leads to $d\sigma/dQ^2$ differential cross section which is
significantly reduced at low $Q^2$.


title: Resource Allocation in Multiple Access Channels

abstract:
  We consider the problem of rate allocation in a Gaussian multiple-access
channel, with the goal of maximizing a utility function over transmission
rates. In contrast to the literature which focuses on linear utility functions,
we study general concave utility functions. We present a gradient projection
algorithm for this problem. Since the constraint set of the problem is
described by exponentially many constraints, methods that use exact projections
are computationally intractable. Therefore, we develop a new method that uses
approximate projections. We use the polymatroid structure of the capacity
region to show that the approximate projection can be implemented by a
recursive algorithm in time polynomial in the number of users. We further
propose another algorithm for implementing the approximate projections using
rate-splitting and show improved bounds on its convergence time.


title: A Comprehensive X-ray Spectral Analysis of the Seyfert 1.5 NGC 3227

abstract:
  We present results of a 100 ks XMM observation of the Seyfert 1.5 NGC 3227.
Our best-fit broadband model to the pn spectrum consists of a moderately flat
(photon index 1.57) hard X-ray power-law absorbed by cold gas with N_H = 3 *
10^21 cm^-2, plus a strong soft excess, modeled as a steep power law with a
photon index of 3.35, absorbed by cold gas with N_H = 9 * 10^20 cm^-2. The soft
excess normalization increases by ~20% in ~20 ks, independently of the hard
X-ray component, and the UV continuum, tracked via the OM, also shows a strong
increasing trend over the observation, consistent with reprocessing of soft
X-ray emission. Warm absorber signatures are evident in both the EPIC and RGS;
we model two layers, with log(xi) = 1.2 and 2.9 erg cm s^-1, and with similar
column densities (~1-2 * 10^21 cm^-2). The outflow velocities relative to
systemic of the high- and low-ionization absorbers are estimated to be
-(2060(+240,-170)) km/s and -(420(+430,-190)) km/s, respectively. The Fe K
alpha line width FWHM is 7000 +/- 1500 km/s; its inferred radius is consistent
with the BLR and with the inner radius of the dust reverberation-mapped by
Suganuma et al. An emission feature near 6.0 keV is modeled equally well as a
narrow redshifted Fe K line, possibly associated with a disk "hot-spot," or as
the red wing to a relativistically broadened Fe line profile. Swift-BAT and
archival RXTE data suggest at most weak Compton reflection (R <~ 0.5), and a
high-energy cutoff near 100 keV. From RXTE monitoring, we find tentative
evidence for a significant fraction of the Fe line flux to track continuum
variations on time scales < 700 days.


title: Unstructured intermediate states in single protein force experiments

abstract:
  Recent single-molecule force measurements on single-domain proteins have
highlighted a three-state folding mechanism where a stabilized intermediate
state (I) is observed on the folding trajectory between the stretched state and
the native state. Here we investigate on-lattice protein-like heteropolymer
models that lead to a three-state mechanism and show that force experiments can
be useful to determine the structure of I. We have mostly found that I is
composed of a core stabilized by a high number of native contacts, plus an
unstructured extended chain. The lifetime of I is shown to be sensitive to
modifications of the protein that spoil the core. We then propose three types
of modifications--point mutations, cuts, and circular permutations--aiming at:
(1) confirming the presence of the core and (2) determining its location,
within one amino acid accuracy, along the polypeptide chain. We also propose
force jump protocols aiming to probe the on/off-pathway nature of I.


title: A Fallback Disk Accretion-Involved Formation Channel to PSR J1903+0327

abstract:
  The discovery of the eccentric binary and millisecond pulsar PSR J1903+03273
has raised interesting questions about the formation mechanisms of this
peculiar system. Here we present a born-fast scenario for PSR J1903+03273. We
assume that during the supernova (SN) explosion that produced the pulsar, a
fallback disk was formed around and accreted onto the newborn neutron star.
Mass accretion could accelerate the neutron star's spin to milliseconds, and
decrease its magnetic field to $\sim 10^8-10^9$ G, provided that there was
sufficient mass ($\sim 0.1 M_{\sun}$) in the fallback disk. The neutron star
became a millisecond pulsar after mass accretion terminated. In the meanwhile
the binary orbit has kept to be eccentric (due to the SN explosion) for $\sim
10^{9}$ yr. We have performed population synthesis calculations of the
evolutions of neutron stars with a fallback disk, and found that there might be
tens to hundreds of PSR J1903+03273-like systems in the Galaxy. This scenario
also suggests that some fraction of isolated millisecond pulsars in the
Galactic disk could be formed through the same channel.


title:
Automated LASCO CME catalog for solar cycle 23: are CMEs scale
  invariant?

abstract:
  In this paper we present the first automatically constructed LASCO CME
catalog, a result of the application of the Computer Aided CME Tracking
software (CACTus) on the LASCO archive during the interval September 1997 -
January 2007. We have studied the CME characteristics and have compared them
with similar results obtained by manual detection (CDAW CME catalog). On
average CACTus detects less than 2 events per day during solar minimum up to 8
events during maximum, nearly half of them being narrow (< 20 degrees).
Assuming a correction factor, we find that the CACTus CME rate is surprisingly
consistent with CME rates found during the past 30 years. The CACTus statistics
show that small scale outflow is ubiquitously observed in the outer corona. The
majority of CACTus-only events are narrow transients related to previous CME
activity or to intensity variations in the slow solar wind, reflecting its
turbulent nature. A significant fraction (about 15%) of CACTus-{\it only}
events were identified as independent events, thus not related to other CME
activity. The CACTus CME width distribution is essentially scale invariant in
angular span over a range of scales from 20 to 120 degrees while previous
catalogues present a broad maximum around 30 degrees. The possibility that the
size of coronal mass outflows follow a power law distribution could indicate
that no typical CME size exists, i.e. that the narrow transients are not
different from the larger well-defined CMEs.


title: Dynamic Rate Allocation in Fading Multiple-access Channels

abstract:
  We consider the problem of rate allocation in a fading Gaussian
multiple-access channel (MAC) with fixed transmission powers. Our goal is to
maximize a general concave utility function of transmission rates over the
throughput capacity region. In contrast to earlier works in this context that
propose solutions where a potentially complex optimization problem must be
solved in every decision instant, we propose a low-complexity approximate rate
allocation policy and analyze the effect of temporal channel variations on its
utility performance. To the best of our knowledge, this is the first work that
studies the tracking capabilities of an approximate rate allocation scheme
under fading channel conditions. We build on an earlier work to present a new
rate allocation policy for a fading MAC that implements a low-complexity
approximate gradient projection iteration for each channel measurement, and
explicitly characterize the effect of the speed of temporal channel variations
on the tracking neighborhood of our policy. We further improve our results by
proposing an alternative rate allocation policy for which tighter bounds on the
size of the tracking neighborhood are derived. These proposed rate allocation
policies are computationally efficient in our setting since they implement a
single gradient projection iteration per channel measurement and each such
iteration relies on approximate projections which has polynomial-complexity in
the number of users.


title: Coherent Manipulation and Decoherence of S=10 Single-Molecule Magnets

abstract:
  We report coherent manipulation of S=10 Fe$_{8}$ single-molecule magnets. The
temperature dependence of the spin decoherence time $T_2$ measured by high
frequency pulsed electron paramagnetic resonance indicates that strong spin
decoherence is dominated by Fe$_{8}$ spin bath fluctuations. By polarizing the
spin bath in Fe$_{8}$ single-molecule magnets at magnetic field $B$ = 4.6 T and
temperature $T$ = 1.3 K, spin decoherence is significantly suppressed and
extends the spin decoherence time $T_2$ to as long as 712 ns. A second
decoherence source is likely due to fluctuations of the nuclear spin bath. This
hints that the spin decoherence time can be further extended via isotopic
substitution to smaller magnetic moments.


title: A proposal for improving the hadronization of QCD currents in TAUOLA

abstract:
  After overviewing the general features of semileptonic decays of the tau
lepton, I will recall the most widely used model for them, namely that of
Kuhn-Santamaria (KS), and I will explain the subsequent works that were done
along these lines and that are implemented in the TAUOLA library for analysing
tau decays. After that, I will move to the description of our project that aims
to achieve a theory as close as possible to QCD for the considered decays. I
conclude by emphasizing the importance of the implementation of our work in
TAUOLA.


title: On spun-normal and twisted squares surfaces

abstract:
  Given a 3 manifold M with torus boundary and an ideal triangulation, Yoshida
and Tillmann give different methods to construct surfaces embedded in M from
ideal points of the deformation variety. Yoshida builds a surface from twisted
squares whereas Tillmann produces a spun-normal surface. We investigate the
relation between the generated surfaces and extend a result of Tillmann's (that
if the ideal point of the deformation variety corresponds to an ideal point of
the character variety then the generated spun-normal surface is detected by the
character variety) to the generated twisted squares surfaces.


title: Uniqueness of solutions for an elliptic equation modeling MEMS

abstract:
  We study the effect of the parameter $\lambda$, the dimension $N$, the
profile $f$ and the geometry of the domain $\Omega \subset\mathbb{R}^N$, on the
question of uniqueness of the solutions to the following elliptic boundary
value problem with a singular nonlinearity: $$ 180pt {{array}{ll} -\Delta u=
\frac{\lambda f(x)}{(1-u)^2} & \hbox{in}\Omega 0<u<1 &\hbox{in}\Omega u=0
&\hbox{on}\partial \Omega. {array}. 130pt (S)_{\lambda, f} $$ This equation has
been proposed as a model for a simple electrostatic Micro-Electromechanical
System (MEMS) device consisting of a thin dielectric elastic membrane with
boundary supported at 0 below a rigid ground plate located at height z = 1.


title:
Direct observation of hydrodynamic instabilities in driven non-uniform
  colloidal dispersions

abstract:
  A Rayleigh-Taylor-like instability of a dense colloidal layer under gravity
in a capillary of microfluidic dimensions is considered. We access all relevant
lengthscales with particle-level microscopy and computer simulations which
incorporate long-range hydrodynamic interactions between the particles. By
tuning the gravitational driving force, we reveal a mechanism whose growth is
connected to the fluctuations of specific wavelengths, non-linear pattern
formation and subsequent diffusion-dominated relaxation. Our linear stability
theory captures the initial regime and thus predicts mixing conditions, with
important implications for fields ranging from biology to nanotechnology.


title: Is the quantum theory predictably complete?

abstract:
  Quantum theory (QT) provides statistical predictions for various physical
phenomena. The outcomes of these measurements are in general some numerical
time series registered by some macroscopic instruments. The various empirical
probability distributions extracted from these time series were shown to be
consistent with the probabilistic predictions of QT. However it was not proven
that the time series of existing experimental data did not contain some
stochastic fine structures, which could have been averaged out by describing
them in terms of the empirical probability distributions. In this paper we
advocate various statistical tests which could be used to search for such fine
structures in the data and to answer the title question of this paper. In our
opinion a proper understanding of the statistical character of QT and of its
limitations is crucial in the domains such as: quantum optics and quantum
information.


title: Rate and Power Allocation in Fading Multiple Access Channels

abstract:
  We consider the problem of rate and power allocation in a fading
multiple-access channel. Our objective is to obtain rate and power allocation
policies that maximize a utility function defined over average transmission
rates. In contrast with the literature, which focuses on the linear case, we
present results for general concave utility functions. We consider two cases.
In the first case, we assume that power control is possible and channel
statistics are known. In this case, we show that the optimal policies can be
obtained greedily by maximizing a linear utility function at each channel
state. In the second case, we assume that power control is not possible and
channel statistics are not available. In this case, we define a greedy rate
allocation policy and provide upper bounds on the performance difference
between the optimal and the greedy policy. Our bounds highlight the dependence
of the performance difference on the channel variations and the structure of
the utility function.


title:
Soft Uncoupling of Markov Chains for Permeable Language Distinction: A
  New Algorithm

abstract:
  Without prior knowledge, distinguishing different languages may be a hard
task, especially when their borders are permeable. We develop an extension of
spectral clustering -- a powerful unsupervised classification toolbox -- that
is shown to resolve accurately the task of soft language distinction. At the
heart of our approach, we replace the usual hard membership assignment of
spectral clustering by a soft, probabilistic assignment, which also presents
the advantage to bypass a well-known complexity bottleneck of the method.
Furthermore, our approach relies on a novel, convenient construction of a
Markov chain out of a corpus. Extensive experiments with a readily available
system clearly display the potential of the method, which brings a visually
appealing soft distinction of languages that may define altogether a whole
corpus.


title:
The $^{22}$Ne($\alpha$,n)$^{25}$Mg neutron source: latest experimental
  results and prospects

abstract:
  The current status of the reaction rate of $^{22}$Ne($\alpha$,n)$^{25}$Mg is
summarized. Among the latest new results, probably the most relevant is the
conclusion that the E$_x$=11.15 MeV state in $^{26}$Mg has a non-natural
parity, so it does not contribute to the rates of the $\alpha$ + $^{22}$Ne
reactions. However, it may be possible that other neighboring states contribute
to the neutron yield at stellar temperatures. Here we make an account of some
of the experimental work in the literature that is relevant to this state.
Indeed, it would have been possible to avoid the controversy regarding this
state before it even started.


title:
Minimally Allowed Neutrinoless Double Beta Decay Rates From Approximate
  Flavor Symmetries

abstract:
  Neutrinoless double beta decay ($\beta\beta0\nu$) is among the only realistic
probes of Majorana neutrinos. In the standard scenario, dominated by light
neutrino exchange, the process amplitude is proportional to $m_{ee}$, the $e-e$
element of the Majorana mass matrix. Naively, current data allows for vanishing
$m_{ee}$, but this should be protected by an appropriate flavor symmetry. All
such symmetries lead to mass matrices inconsistent with oscillation
phenomenology. I perform a spurion analysis to break all possible Abelian
symmetries that guarantee vanishing $\beta\beta0\nu$ rates and search for
minimally allowed values. I survey 230 broken structures to yield $m_{ee}$
values and current phenomenological constraints under a variety of scenarios.
This analysis also extracts predictions for both neutrino oscillation
parameters and kinematic quantities. Assuming reasonable tuning levels, I find
that $m_{ee}>4\times 10^{-6}$ eV at 99% confidence. Bounds below this value
might indicate the Dirac neutrino nature or the existence of new light (eV-MeV
scale) degrees of freedom that can potentially be probed elsewhere.


title:
Field test of a practical secure communication network with decoy-state
  quantum cryptography

abstract:
  We present a secure network communication system that operated with
decoy-state quantum cryptography in a real-world application scenario. The full
key exchange and application protocols were performed in real time among three
nodes, in which two adjacent nodes were connected by approximate 20 km of
commercial telecom optical fiber. The generated quantum keys were immediately
employed and demonstrated for communication applications, including unbreakable
real-time voice telephone between any two of the three communication nodes, or
a broadcast from one node to the other two nodes by using one-time pad
encryption.


title: On the Minkowski Measure

abstract:
  The Minkowski Question Mark function relates the continued-fraction
representation of the real numbers, to their binary expansion. This function is
peculiar in many ways; one is that its derivative is 'singular'. One can show
by classical techniques that its derivative must vanish on all rationals. Since
the Question Mark itself is continuous, one concludes that the derivative must
be non-zero on the irrationals, and is thus a discontinuous-everywhere
function. This derivative is the subject of this essay.
  Various results are presented here: First, a simple but formal
measure-theoretic construction of the derivative is given, making it clear that
it has a very concrete existence as a Lebesgue-Stieltjes measure, and thus is
safe to manipulate in various familiar ways. Next, an exact result is given,
expressing the measure as an infinite product of piece-wise continuous
functions, with each piece being a Mobius transform of the form (ax+b)/(cx+d).
This construction is then shown to be the Haar measure of a certain transfer
operator. A general proof is given that any transfer operator can be understood
to be nothing more nor less than a push-forward on a Banach space; such
push-forwards induce an invariant measure, the Haar measure, of which the
Minkowski measure can serve as a prototypical example. Some minor notes
pertaining to it's relation to the Gauss-Kuzmin-Wirsing operator are made.


title: Regularity of the extremal solution in a MEMS model with advection

abstract:
  We consider the regularity of the extremal solution of the nonlinear
eigenvalue problem (S)_\lambda \qquad {rcr} -\Delta u + c(x) \cdot \nabla u &=&
\frac{\lambda}{(1-u)^2} \qquad {in $ \Omega$}, u &=& 0 \qquad {on $ \pOm$},
where $ \Omega $ is a smooth bounded domain in $ \IR^N$ and $ c(x)$ is a smooth
bounded vector field on $\bar \Omega$. We show that, just like in the
advection-free model ($c\equiv 0$), all semi-stable solutions are smooth if
(and only if) the dimension $N\leq 7$. The novelty here comes from the lack of
a suitable variational characterization for the semi-stability assumption. We
overcome this difficulty by using a general version of Hardy's inequality. In a
forthcoming paper \cite{CG2}, we indicate how this method applies to many other
nonlinear eigenvalue problems involving advection (including the Gelfand
problem), showing that they all essentially have the same critical dimension as
their advection-free counterparts.


title:
Information Theory vs. Queueing Theory for Resource Allocation in
  Multiple Access Channels

abstract:
  We consider the problem of rate allocation in a fading Gaussian
multiple-access channel with fixed transmission powers. The goal is to maximize
a general concave utility function of the expected achieved rates of the users.
There are different approaches to this problem in the literature. From an
information theoretic point of view, rates are allocated only by using the
channel state information. The queueing theory approach utilizes the global
queue-length information for rate allocation to guarantee throughput optimality
as well as maximizing a utility function of the rates. In this work, we make a
connection between these two approaches by showing that the information
theoretic capacity region of a multiple-access channel and its stability region
are equivalent. Moreover, our numerical results show that a simple greedy
policy which does not use the queue-length information can outperform
queue-length based policies in terms of convergence rate and fairness.


title: Bi-directional half-duplex protocols with multiple relays

abstract:
  In a bi-directional relay channel, two nodes wish to exchange independent
messages over a shared wireless half-duplex channel with the help of relays.
Recent work has considered information theoretic limits of the bi-directional
relay channel with a single relay. In this work we consider bi-directional
relaying with multiple relays. We derive achievable rate regions and outer
bounds for half-duplex protocols with multiple decode and forward relays and
compare these to the same protocols with amplify and forward relays in an
additive white Gaussian noise channel. We consider three novel classes of
half-duplex protocols: the (m,2) 2 phase protocol with m relays, the (m,3) 3
phase protocol with m relays, and general (m, t) Multiple Hops and Multiple
Relays (MHMR) protocols, where m is the total number of relays and 3<t< m+3 is
the number of temporal phases in the protocol. The (m,2) and (m,3) protocols
extend previous bi-directional relaying protocols for a single m=1 relay, while
the new (m,t) protocol efficiently combines multi-hop routing with
message-level network coding. Finally, we provide a comprehensive treatment of
the MHMR protocols with decode and forward relaying and amplify and forward
relaying in the Gaussian noise, obtaining their respective achievable rate
regions, outer bounds and relative performance under different SNRs and relay
geometries, including an analytical comparison on the protocols at low and high
SNR.


title: Measurement of the Optical Conductivity of Graphene

abstract:
  Optical reflectivity and transmission measurements over photon energies
between 0.2 and 1.2 eV were performed on single-crystal graphene samples on a
transparent SiO2 substrate. For photon energies above 0.5 eV, graphene yielded
a spectrally flat optical absorbance of (2.3 +/- 0.2)%. This result is in
agreement with a constant absorbance of pi*alpha, or a sheet conductivity of
pi*e^2/2h, predicted within a model of non-interacting massless Dirac Fermions.
This simple result breaks down at lower photon energies, where both spectral
and sample-to-sample variations were observed. This "non-universal" behavior is
explained by including the effects of doping and finite temperature, as well as
contributions from intraband transitions.


title:
Studies of Parton Propagation and Hadron Formation in the Space-Time
  Domain

abstract:
  Over the past decade, new data from HERMES, Jefferson Lab, Fermilab, and RHIC
that connect to parton propagation and hadron formation have become available.
Semi-inclusive DIS on nuclei, the Drell-Yan reaction, and heavy-ion collisions
all bring different kinds of information on parton propagation within a medium,
while the most direct information on hadron formation comes from the DIS data.
Over the next decade one can hope to begin to understand these data within a
unified picture. We briefly survey the most relevant data and the common
elements of the physics picture, then highlight the new Jefferson Lab data, and
close with a prospective for the future.


title: The Motion of Water Masers in the Pre-Planetary Nebula IRAS 16342-3814

abstract:
  We present high angular resolution observations, using the Very Long Baseline
Array (VLBA) of the NRAO, of the high-velocity water masers toward the
"water-fountain" pre-planetary nebula, IRAS 16342-3814. The detailed structure
of the water masers appears to be that of bow shocks on either side of a highly
collimated jet. The proper motions of the water masers are approximately equal
to the radial velocities; the three-dimensional velocities are approximately
+/-180 km/s, which leads to a very short dynamical time-scale of ~100 years.
Although we do not find direct evidence for precession of the fast collimated
jet, there may be indirect evidence for such precession.


title: The Enrichment of the Intracluster Medium

abstract:
  To determine the relative contributions of galactic and intracluster stars to
the enrichment of the intracluster medium (ICM), we present X-ray surface
brightness, temperature, and Fe abundance profiles for a set of twelve galaxy
clusters for which we have extensive optical photometry. Assuming a standard
IMF and simple chemical evolution model scaled to match the present-day cluster
early-type SN Ia rate, the stars in the brightest cluster galaxy (BCG) plus the
intracluster stars (ICS) generate 31^{+11}_{-9}%, on average, of the observed
ICM Fe within r_{500} (~ 0.6 times r_{200}, the virial radius). An alternate,
two-component SN Ia model (including both prompt and delayed detonations)
produces a similar BCG+ICS contribution of 22^{+9}_{-9}%. Because the ICS
typically contribute 80% of the BCG+ICS Fe, we conclude that the ICS are
significant, yet often neglected, contributors to the ICM Fe within r_{500}.
However, the BCG+ICS fall short of producing all the Fe, so metal loss from
stars in other cluster galaxies must also contribute. By combining the
enrichment from intracluster and galactic stars, we can account for all the
observed Fe. These models require a galactic metal loss fraction
(0.84^{+0.11}_{-0.14}) that, while large, is consistent with the metal mass not
retained by galactic stars. The SN Ia rates, especially as a function of galaxy
environment and redshift, remain a significant source of uncertainty in further
constraining the metal loss fraction. For example, increasing the SN Ia rate by
a factor of 1.8 -- to just within the 2 sigma uncertainty for present-day
cluster early-type galaxies -- allows the combined BCG + ICS + cluster galaxy
model to generate all the ICM Fe with a much lower galactic metal loss fraction
(~ 0.35).


title: X-ray tracing using Geant4

abstract:
  We describe an extension to the Geant4 software package that allows it to be
used as a general purpose X-ray tracing package. We demonstrate its use by
building a model of the X-ray optics of the XMM-Newton, calculating its
effective area, and comparing the results with the published calibration
curves.


title: Light Dragging, the Origin of Hubble's Constant

abstract:
  Recently E. Harrison has argued the Red Shift distance law proposed by Hubble
and velocity-distance law developed later on theoretical grounds has no general
proof demonstrating the two laws are actually equivalent. It is the purpose of
this paper to account for the nebular redshift law of Hubble based on two
principles: 1) Spacetime motion and light dragging. 2) An overall spacetime
index of refraction based on Hubble's Constant.


title: Possible Odderon Effects in Hadron-Nucleon Scattering

abstract:
  We consider the possible contribution of Odderon (Reggeon with
\alpha_{Odd}(0) \sim 1 and negative signature) exchange to the differences in
the total cross sections of particle and antiparticle, to the ratios of
real/imaginary parts of the elastic pp amplitude, and to the differences in the
inclusive spectra of particle and antiparticle in the central region. The
experimental differences in total cross sections of particle and antiparticle
are compatible with the existence of the Odderon component but such a large
Odderon contribution seems to be inconsistent with the values of Re/Im ratios.
In the case of inclusive particle and antiparticle production the current
energies and/or accuracy of the experimental data don't allow a clear
conclusion.


title: Counting open nodal lines of random waves on planar domains

abstract:
  We compute the asymptotic expectation of the number of {\em open} nodal lines
for random waves on smooth planar domains. We find that for both the long
energy window $[0,\lambda]$ and the short one $[\lambda,\lambda+1]$ the
expected number of open nodal lines is proportional to $\lambda$,
asymptotically as $\lambda\to\infty$. Our results are consistent with the
predictions in the physics literature made by Blum, Gnutzmann and Smilansky
\cite{BGS}.


title: A Common Origin for Neutrino Anarchy and Charged Hierarchies

abstract:
  The generation of exponential flavor hierarchies from extra-dimensional
wavefunction overlaps is re-examined. We find, surprisingly, that coexistence
of anarchic fermion mass matrices with such hierarchies is intrinsic and
natural to this setting. The salient features of charged fermion and neutrino
masses and mixings can thereby be captured within a single framework. Both
Dirac and Majorana neutrinos can be realized. The minimal phenomenological
consequences are discussed, including the need for a fundamental scale far
above the weak scale to adequately suppress flavor-changing neutral currents.
Two broad scenarios for stabilizing this electroweak hierarchy are studied,
warped compactification and supersymmetry. In warped compactifications and
"Flavorful Supersymmetry," where non-trivial flavor structure appears in the
new TeV physics, Dirac neutrinos are strongly favored over Majorana by lepton
flavor violation tests. We argue that this is part of a more general result for
flavor-sensitive TeV-scale physics. Our scenario strongly suggests that the
supersymmetric flavor problem is not solved locally in the extra dimension, but
rather at or below the compactification scale. In the supersymmetric Dirac
case, we discuss how the appearance of light right-handed sneutrinos
considerably alters the physics of dark matter.


title: Log canonical thresholds of binomial ideals

abstract:
  We prove that the log canonical thresholds of a large class of binomial
ideals, such as complete intersection binomial ideals and the defining ideals
of space monomial curves, are computable by linear programming.


title: Set theory for category theory

abstract:
  Questions of set-theoretic size play an essential role in category theory,
especially the distinction between sets and proper classes (or small sets and
large sets). There are many different ways to formalize this, and which choice
is made can have noticeable effects on what categorical constructions are
permissible. In this expository paper we summarize and compare a number of such
"set-theoretic foundations for category theory," and describe their
implications for the everyday use of category theory. We assume the reader has
some basic knowledge of category theory, but little or no prior experience with
formal logic or set theory.


title: Berry Phase and Supersymmetry

abstract:
  We study the constraints of supersymmetry on the non-Abelian holonomy given
by U=P exp(i\int A), the path-ordered exponential of a connection A. For
theories with four supercharges, we show that A satisfies the tt* equations if
it is a function of chiral multiplets. In contrast, when A is a function of
vector multiplets, it satisfies the Bogomolnyi monopole equations. We describe
applications of these results to the Berry connection in supersymmetric quantum
mechanics.


title:
Nontrivial interplay between superconductivity and spin-orbit coupling
  in non-centrosymmetric ferromagnets

abstract:
  Motivated by the recent discoveries of ferromagnetic and non-centrosymmetric
superconductors, we present a mean-field theory for a superconductor that
\textit{both} lacks inversion symmetry and displays ferromagnetism, a scenario
which is believed to be realized in UIr. We study the interplay between the
order parameters to clarify how superconductivity is affected by the presence
of ferromagnetism and spin-orbit coupling. One of our key findings is that the
spin-orbit coupling seems to enhance both ferromagnetism and superconductivity
in all spin channels. We discuss our results in the context of the heavy
fermion superconductor UIr and analyze possible symmetries of the order
parameter by the group theory method.


title: Thermodynamics of atmospheric circulation on hot Jupiters

abstract:
  Atmospheric circulation on tidally-locked exoplanets is driven by the
absorption and reradiation of heat from the host star. They are natural heat
engines, converting heat into mechanical energy. A steady state is possible
only if there is a mechanism to dissipate mechanical energy, or if the
redistribution of heat is so effective that the Carnot efficiency is driven to
zero. Simulations based on primitive, equivalent-barotropic, or shallow-water
equations without explicit provision for dissipation of kinetic energy and for
recovery of that energy as heat, violate energy conservation. More seriously
perhaps, neglect of physical sources of drag may overestimate wind speeds and
rates of advection of heat from the day to the night side.


title: The GALFA-HI Survey: Techniques

abstract:
  We explain the entire process by which we conduct the Galactic Arecibo L-Band
Feed Array HI (GALFA-HI) survey. The survey is a high resolution (3.4'), large
area (13000 deg^2), large Galactic velocity range (-750 to +750 km/s), high
spectral resolution (0.18 km/s) survey of the Galaxy in the 21 cm line
hyperfine transition of hydrogen conducted at Arecibo Observatory. We touch on
some of the new Galactic science being conducted using the GALFA-HI survey,
ranging from High-Velocity Clouds to HI narrow-line self-absorption. We explain
the many technical challenges that confront such a survey, including baseline
ripple, gain variation and asymmetrical beam shapes. To correct for these
systematic effects we use various newly developed methods, which we describe in
detail. We also explain the data reduction process step by step, starting with
the raw time-ordered data and ending with fully calibrated maps. The effects of
each step of the data reduction on the final data product is shown
sequentially. We conclude with future directions for the ongoing survey.


title:
The Gamma-Ray-Flux Probability Distribution Function from Galactic Halo
  Substructure

abstract:
  One of the targets of the recently launched Fermi Gamma-ray Space Telescope
is a diffuse gamma-ray background from dark-matter annihilation or decay in the
Galactic halo. N-body simulations and theoretical arguments suggest that the
dark matter in the Galactic halo may be clumped into substructure, rather than
smoothly distributed. Here we propose the gamma-ray-flux probability
distribution function (PDF) as a probe of substructure in the Galactic halo. We
calculate this PDF for a phenomenological model of halo substructure and
determine the regions of the substructure parameter space in which the PDF may
be distinguished from the PDF for a smooth distribution of dark matter. In
principle, the PDF allows a statistical detection of substructure, even if
individual halos cannot be detected. It may also allow detection of
substructure on the smallest microhalo mass scales, $\sim M_\oplus$, for
weakly-interacting massive particles (WIMPs). Furthermore, it may also provide
a method to measure the substructure mass function. However, an analysis that
assumes a typical halo substructure model and a conservative estimate of the
diffuse background suggests that the substructure PDF may not be detectable in
the lifespan of Fermi in the specific case that the WIMP is a neutralino.
Nevertheless, for a large range of substructure, WIMP annihilation, and diffuse
background models, PDF analysis may provide a clear signature of substructure.


title: iCosmo: an Interactive Cosmology Package

abstract:
  Aims: The interactive software package iCosmo, designed to perform
cosmological calculations is described. Methods: iCosmo is a software package
to perform interactive cosmological calculations for the low redshift universe.
Computing distance measures, the matter power spectrum, and the growth factor
is supported for any values of the cosmological parameters. It also computes
derived observed quantities for several cosmological probes such as cosmic
shear, baryon acoustic oscillations and type Ia supernovae. The associated
errors for these observables can be derived for customised surveys, or for
pre-set values corresponding to current or planned instruments. The code also
allows for the calculation of cosmological forecasts with Fisher matrices which
can be manipulated to combine different surveys and cosmological probes. The
code is written in the IDL language and thus benefits from the convenient
interactive features and scientific library available in this language. iCosmo
can also be used as an engine to perform cosmological calculations in batch
mode, and forms a convenient adaptive platform for the development of further
cosmological modules. With its extensive documentation, it may also serve as a
useful resource for teaching and for newcomers in the field of cosmology.
Results: The iCosmo package is described with various examples and command
sequences. The code is freely available with documentation at
http://www.icosmo.org, along with an interactive web interface and is part of
the Initiative for Cosmology, a common archive for cosmological resources.


title: How to De-Rotate the Cosmic Microwave Background Polarization

abstract:
  If the linear polarization of the cosmic microwave background (CMB) is
rotated in a frequency-independent manner as it propagates from the surface of
last scatter, it may introduce a B-mode polarization. Here I show that
measurement of higher-order TE, EE, EB, and TB correlations induced by this
rotation can be used to reconstruct the rotation angle as a function of
position on the sky. This technique can be used to distinguish primordial B
modes from those induced by rotation. The effects of rotation can be
distinguished geometrically from similar effects due to cosmic shear.


title:
Prompt TeV Emission from Cosmic Rays Accelerated by Gamma Ray Bursts
  Interacting with Surrounding Stellar Wind

abstract:
  Protons accelerated in the internal shocks of a long duration gamma ray burst
can escape the fireball as cosmic rays by converting to neutrons. Hadronic
interactions of these neutrons inside a stellar wind bubble created by the
progenitor star will produce TeV gamma rays via neutral meson decay and
synchrotron radiation by charged pion-decay electrons in the wind magnetic
field. Such gamma rays should be observable from nearby gamma ray bursts by
currently running and upcoming ground-based detectors.


title:
Stellar disruption by a supermassive black hole: is the light curve
  really proportional to $t^{-5/3}$?

abstract:
  In this paper we revisit the arguments for the basis of the time evolution of
the flares expected to arise when a star is disrupted by a supermassive black
hole. We present a simple analytic model relating the lightcurve to the
internal density structure of the star. We thus show that the standard
lightcurve proportional to $t^{-5/3}$ only holds at late times. Close to the
peak luminosity the lightcurve is shallower, deviating more strongly from
$t^{-5/3}$ for more centrally concentrated (e.g. solar--type) stars. We test
our model numerically by simulating the tidal disruption of several stellar
models, described by simple polytropic spheres with index $\gamma$. The
simulations agree with the analytical model given two considerations. First,
the stars are somewhat inflated on reaching pericentre because of the effective
reduction of gravity in the tidal field of the black hole. This is well
described by a homologous expansion by a factor which becomes smaller as the
polytropic index becomes larger. Second, for large polytropic indices wings
appear in the tails of the energy distribution, indicating that some material
is pushed further away from parabolic orbits by shocks in the tidal tails. In
all our simulations, the $t^{-5/3}$ lightcurve is achieved only at late stages.
In particular we predict that for solar type stars, this happens only after the
luminosity has dropped by at least two magnitudes from the peak. We discuss our
results in the light of recent observations of flares in otherwise quiescent
galaxies and note the dependence of these results on further parameters, such
as the star/hole mass ratio and the stellar orbit.


title:
Long tunneling contact as a probe of fractional quantum Hall neutral
  edge modes

abstract:
  We study the tunneling current between edge states of quantum Hall liquids
across a single long contact region, and predict a resonance at a bias voltage
set by the scale of the edge velocity. For typical devices and edge velocities
associated with charged modes, this resonance occurs outside the physically
accessible bias domain. However, for edge states that are expected to support
neutral modes, such as the $\nu={2/3}$, and $\nu={5/2}$ Pfaffian and
anti-Pfaffian states, the neutral velocity can be orders of magnitude smaller
than the charged mode and if so the resonance would be accessible. Therefore,
such long tunneling contacts can resolve the presence of neutral edge modes in
certain quantum Hall liquids.


title: Galaxy formation & evolution: the far-ir/sub-mm view

abstract:
  We review our current knowledge of the population of high-redshift sub-mm/mm
galaxies, with particular emphasis on recent results from the SCUBA HAlf Degree
Extragalactic Survey (SHADES). All available evidence indicates that these
objects form the high-redshift, high-luminosity, high-mass tail of the dusty
starforming galaxy population revealed at lower redshifts and luminosities by
Spitzer. Current theoretical models of galaxy formation struggle to reproduce
these extreme objects in the numbers indicated by current surveys.