title: Limits of slow-light in photonic crystals

abstract:
  While ideal photonic crystals would support modes with a vanishing group
velocity, state-of-the art structures have still only provided a slow-down by
roughly two orders of magnitude. We find that the induced density of states
caused by lifetime broadening of the electromagnetic modes results in the group
velocity acquiring a finite value above zero at the band gap edges, while
attaining superluminal values within the band gap. Simple scalings of the
minimum and maximum group velocities with the imaginary part of the dielectric
function or, equivalently, the linewidth of the broadened states, are
presented. The results obtained are entirely general and may be applied to any
effect which results in a broadening of the electromagnetic states, such as
loss, disorder, finite-size effects, etc. This significantly limits the
reduction in group velocity attainable via photonic crystals.


title: Some limit theorems for rescaled Wick powers

abstract:
  We establish the strong L2(P)-convergence of properly rescaled Wick powers as
the power index tends to infinity. The explicit representation of such limit
will also provide the convergence in distribution to normal and log-normal
random variables. The proofs rely on some estimates for the L2(P)-norm of Wick
products and on the properties of second quantization operators.


title:
A Four Component Picture for Jet Induced Correlations in Heavy Ion
  Collisions?

abstract:
  These proceedings review recent results from two and three particle
correlations in heavy ion collisions. In particular we discuss the modified
structure of the away side jet correlations. Under the assumption that the away
side can be decomposed into a punch through component at $\Delta\phi=\pi$ and a
shoulder component with a peak displaced from $\pi$ many similar properties are
observed between the ridge and shoulder. The particle ratios, yields and $p_T$
spectra are in near agreement. We also highlight important future measurements,
including investigating if the decomposition of the away side jet correlations
remains reasonable with high $p_T$ triggers and technical improvements to the
extraction of jet induced correlations.


title: Finitely presented residually free groups

abstract:
  We establish a general criterion for the finite presentability of subdirect
products of groups and use this to characterize finitely presented residually
free groups. We prove that, for all $n\in\mathbb{N}$, a residually free group
is of type ${\rm{FP}}_n$ if and only if it is of type ${\rm{F}}_n$.
  New families of subdirect products of free groups are constructed, including
the first examples of finitely presented subgroups that are neither
${\rm{FP}}_\infty$ nor of Stallings-Bieri type. The template for these examples
leads to a more constructive characterization of finitely presented residually
free groups up to commensurability.
  We show that the class of finitely presented residually free groups is
recursively enumerable and present a reduction of the isomorphism problem. A
new algorithm is described which, given a finite presentation of a residually
free group, constructs a canonical embedding into a direct product of finitely
many limit groups.
  The (multiple) conjugacy and membership problems for finitely presented
subgroups of residually free groups are solved.


title:
Divergence of the Magnetic Gr\"{u}neisen Ratio at the Field-Induced
  Quantum Critical Point in YbRh$_2$Si$_2$

abstract:
  The heavy fermion compound YbRh$_2$Si$_2$ is studied by low-temperature
magnetization $M(T)$ and specific-heat $C(T)$ measurements at magnetic fields
close to the quantum critical point ($H_c=0.06$ T, $H\perp c$). Upon
approaching the instability, $dM/dT$ is more singular than $C(T)$, leading to a
divergence of the magnetic Gr\"uneisen ratio $\Gamma_{\rm mag}=-(dM/dT)/C$.
Within the Fermi liquid regime, $\Gamma_{\rm mag}=-G_r(H-H_c^{fit})$ with
$G_r=-0.30\pm 0.01$ and $H_c^{fit}=(0.065\pm 0.005)$ T which is consistent with
scaling behavior of the specific-heat coefficient in
YbRh$_2$(Si$_{0.95}$Ge$_{0.05}$)$_2$. The field-dependence of $dM/dT$ indicates
an inflection point of the entropy as a function of magnetic field upon passing
the line $T^\star(H)$ previously observed in Hall- and thermodynamic
measurements.


title: Action of the gravitational field on the dynamical Casimir effect

abstract:
  In this paper we analyze the action of the gravitational field on the
dynamical Casimir effect. We consider a massless scalar field confined in a
cuboid cavity placed in a gravitational field described by a static and
diagonal metric. With one of the plane mirrors of the cavity allowed to move,
we compute the average number of particles created inside the cavity by means
of the Bogoliubov coefficients computed through perturbative expansions. We
apply our result to the case of an oscillatory motion of the mirror, assuming a
weak gravitational field described by the Schwarzschild metric. The regime of
parametric amplification is analyzed in detail, demonstrating that our computed
result for the mean number of particles created agrees with specific associated
cases in the literature. Our results, obtained in the framework of the
perturbation theory, are restricted, under resonant conditions, to a short-time
limit.


title: Surgical distance between lens spaces

abstract:
  It is well-known that any pair of closed orientable 3-manifolds are related
by a finite sequence of Dehn surgeries on knots. Furthermore Kawauchi showed
that such knots can be taken to be hyperbolic. In this article, we consider the
minimal length of such sequences connecting a pair of 3-manifolds, in
particular, a pair of lens spaces.


title: Prospects for SUSY searches in CMS and ATLAS

abstract:
  We discuss how the CMS and ATLAS experiments are preparing for the analysis
of first LHC data with emphasis on the search for supersymmetry. We will show
the importance of the understanding of detector, trigger, reconstruction and
backgrounds, and we will present realistic estimates of the reach of CMS and
ATLAS.


title: Out of Equilibrium Solutions in the $XY$-Hamiltonian Mean Field model

abstract:
  Out of equilibrium magnetised solutions of the $XY$-Hamiltonian Mean Field
($XY$-HMF) model are build using an ensemble of integrable uncoupled pendula.
Using these solutions we display an out-of equilibrium phase transition using a
specific reduced set of the magnetised solutions.


title: A note on certain Kronecker coefficients

abstract:
  We prove an explicit formula for the tensor product with itself of an
irreducible complex representation of the symmetric group defined by a
rectangle of height two. We also describe part of the decomposition for the
tensor product of representations defined by rectangles of heights two and
four. Our results are deduced, through Schur-Weyl duality, from the observation
that certain actions on triple tensor products of vector spaces, are
multiplicity free.


title: Chirplet approximation of band-limited, real signals made easy

abstract:
  In this paper we present algorithms for approximating real band-limited
signals by multiple Gaussian Chirps. These algorithms do not rely on matching
pursuit ideas. They are hierarchial and, at each stage, the number of terms in
a given approximation depends only on the number of positive-valued maxima and
negative-valued minima of a signed amplitude function characterizing part of
the signal. Like the algorithms used in \cite{gre2} and unlike previous
methods, our chirplet approximations require neither a complete dictionary of
chirps nor complicated multi-dimensional searches to obtain suitable choices of
chirp parameters.


title: Entanglement Resonance in Driven Spin Chains

abstract:
  We consider a spin-1/2 anisotropic XY model with time-dependent spin-spin
coupling as means of creating long-distance entanglement. We predict the
emergence of significant entanglement between the first and the last spin
whenever the ac part of the coupling has a frequency matching the Zeeman
splitting. In particular, we find that the concurrence assumes its maximum with
a vanishing dc part. Mapping the time-dependent Hamiltonian within a
rotating-wave approximation to an effective static model provides qualitative
and quantitative understanding of this entanglement resonance. Numerical
results for the duration of the entanglement creation and its length dependence
substantiate the effective static picture.


title:
Experimental evidence of an instability over an impedance wall in a duct
  with flow

abstract:
  An experimental investigation of the acoustical behaviour of a liner in a
rectangu- lar channel with grazing flow has been conducted. The liner consists
of a ceramic structure of parallel square channels: 1mm by 1 mm in cross
section, 65 mm in length, and a surface density of 400 channels/inch square.
The channels are rigidly terminated, thus constituting a locally reacting
structure. In the absence of flow the liner reacts classically: There is a
significant decrease in transmission coefficient around the frequency of
minimal impedance. When the wall is exposed to a grazing flow this behaviour is
changed: an increase in transmission coefficient appears at this resonance
frequency. The transmission coefficient can be even rise above 1 (up to 3 for a
Mach number of 0.3). This behaviour is caused by the appearance of a
hydrodynamic instability above the liner. Furthermore, the stationary pressure
drop induced by this liner is deeply affected by its acoustic behaviour. When a
sound wave is added, at the resonance frequency of the liner, the pressure drop
can increase by a factor 3 when the Mach number is 0.3. This effect is
attributed to a modification of the turbulent boundary layer induced by the
acoustic wave.


title:
Existence, uniqueness and a constructive solution algorithm for a class
  of finite Markov moment problems

abstract:
  We consider a class of finite Markov moment problems with arbitrary number of
positive and negative branches. We show criteria for the existence and
uniqueness of solutions, and we characterize in detail the non-unique solution
families. Moreover, we present a constructive algorithm to solve the moment
problems numerically and prove that the algorithm computes the right solution.


title: Residue Network Construction and Predictions of Elastic Network Models

abstract:
  The past decade has witnessed the development and success of coarse-grained
network models of proteins for predicting many equilibrium properties related
to collective modes of motion. Curiously, the results are usually robust
towards the different methodologies used for constructing the residue networks
from knowledge of the experimental coordinates. We present a systematical study
of network construction strategies, and their effect on the predicted
properties. The analysis is based on the radial distribution function and the
spectral dimensions of a large set of proteins as well as a newly defined
quantity, the angular distribution function. By partitioning the interactions
into an essential and a residual set, we show that the robustness originates
from a large number of long-distance interactions belonging to the latter.
These residuals have a vanishingly small effect on the force vectors on each
residue. The overall force balance then translates into the Hessian as small
shifts in the slow modes of motion and an invariance of the corresponding
eigenvectors. Implications for the study of biologically relevant properties of
proteins are discussed.


title: NNPDF1.0 parton set for the LHC

abstract:
  We present the first NNPDF full set of Parton Distribution Functions from a
comprehensive DIS analysis. This approach, combining a Monte Carlo sampling of
the probability measure in the space of PDFs with the use of neural networks as
interpolating functions, provides a faithful and statistically sound
determination of the uncertainty in parton distributions. The features of the
fit and the results are discussed in details as well as some preliminary
phenomenological analysis


title:
The $\gamma \gamma$ decay of the $f_0(1370)$ and $f_2(1270)$ resonances
  in the hidden gauge formalism

abstract:
  Using recent results obtained within the hidden gauge formalism for vector
mesons, in which the $f_0(1370)$ and $f_2(1270)$ resonances are dynamically
generated resonances from the $\rho \rho$ interaction, we evaluate the
radiative decay of these resonances into $\gamma \gamma$. We obtain results for
the width in good agreement with the experimental data for the $f_2(1270)$
state and a width about a factor five smaller for the $f_0(1370)$ resonance,
which would agree with preliminary results from the Belle collaboration,
hinting at an order of magnitude smaller width for this resonance than for the
$f_2(1270)$.


title: Asymptotics of LQG fusion coefficients

abstract:
  The fusion coefficients from SO(3) to SO(4) play a key role in the definition
of spin foam models for the dynamics in Loop Quantum Gravity. In this paper we
give a simple analytic formula of the EPRL fusion coefficients. We study the
large spin asymptotics and show that they map SO(3) semiclassical intertwiners
into $SU(2)_L\times SU(2)_R$ semiclassical intertwiners. This non-trivial
property opens the possibility for an analysis of the semiclassical behavior of
the model.


title:
New examples of finitely presented groups with strong fixed point
  properties

abstract:
  The aim of this note is to give an easy example of a finitely presented group
that cannot act without a fix point on a CAT(0) space of finite dimension. Such
an example has been recently constructed by Arjantseva et al., using other
techniques


title: Cremona transformations and diffeomorphisms of surfaces

abstract:
  We show that the action of Cremona transformations on the real points of
quadrics exhibits the full complexity of the diffeomorphisms of the sphere, the
torus, and of all non-orientable surfaces. The main result says that if X is
rational, then Aut(X), the group of algebraic automorphisms, is dense in
Diff(X), the group of self-diffeomorphisms of X.


title:
An Inexpensive Field-Widened Monolithic Michelson Interferometer for
  Precision Radial Velocity Measurements

abstract:
  We have constructed a thermally compensated field-widened monolithic
Michelson interferometer that can be used with a medium-resolution spectrograph
to measure precise Doppler radial velocities of stars. Our prototype monolithic
fixed-delay interferometer is constructed with off-the-shelf components and
assembled using a hydrolysis bonding technique. We installed and tested this
interferometer in the Exoplanet Tracker (ET) instrument at the Kitt Peak 2.1m
telescope, an instrument built to demonstrate the principles of dispersed fixed
delay interferometry. An iodine cell allows the interferometer drift to be
accurately calibrated, relaxing the stability requirements on the
interferometer itself. When using our monolithic interferometer, the ET
instrument has no moving parts (except the iodine cell), greatly simplifying
its operation. We demonstrate differential radial velocity precision of a few m
s$^{-1}$ on well known radial velocity standards and planet bearing stars when
using this interferometer. Such monolithic interferometers will make it
possible to build relatively inexpensive instruments that are easy to operate
and capable of precision radial velocity measurements. A larger multi-object
version of the Exoplanet Tracker will be used to conduct a large scale survey
for planetary systems as part of the Sloan Digital Sky Survey III (SDSS III).
Variants of the techniques and principles discussed in this paper can be
directly applied to build large monolithic interferometers for such
applications, enabling the construction of instruments capable of efficiently
observing many stars simultaneously at high velocity-precision.


title:
The Luminosity and Energy Dependence of Pulse Phase Lags in the
  Accretion-powered Millisecond Pulsar SAX J1808.4-3658

abstract:
  Soft phase lags, in which X-ray pulses in lower energy bands arrive later
than pulses in higher energy bands, have been observed in nearly all
accretion-powered millisecond pulsars, but their origin remains an open
question. In a study of the 2.5 ms accretion-powered pulsar SAX J1808.4-3658,
we report that the magnitude of these lags is strongly dependent on the
accretion rate. During the brightest stage of the outbursts from this source,
the lags increase in magnitude as the accretion rate drops; when the outbursts
enter their dimmer flaring-tail stage, the relationship reverses. We evaluate
this complex dependence in the context of two theoretical models for the lags,
one relying on the scattering of photons by the accretion disk and the other
invoking a two-component model for the photon emission. In both cases, the
turnover suggests that we are observing the source transitioning into the
"propeller" accretion regime.


title:
Determination of the Spin Polarization of RFe2 (R = Dy, Er, Y) by Point
  Contact Andreev Reflection

abstract:
  Epitaxially grown intermetallic RFe2 (R = Dy, Er, Y) thin films have been
studied by point contact Andreev reflection. Spin polarization values were
extracted by fitting normalized conductance curves for mechanical Nb/RFe2 point
contacts, using a modified Blonder-Tinkham-Klapwijk (BTK) model. Good agreement
is found between this model and the experimentally obtained data. Extracted
values of spin polarization, which are close to the spin polarization of Fe,
reveal no variation with the rare earth component for the measured
intermetallic compounds. This suggests that using this technique we probe the
Fe sub-lattice, and that this lattice drives spintronic effects in these
compounds.


title:
Weighted graphs defining facets: a connection between stable set and
  linear ordering polytopes

abstract:
  A graph is alpha-critical if its stability number increases whenever an edge
is removed from its edge set. The class of alpha-critical graphs has several
nice structural properties, most of them related to their defect which is the
number of vertices minus two times the stability number. In particular, a
remarkable result of Lov\'asz (1978) is the finite basis theorem for
alpha-critical graphs of a fixed defect. The class of alpha-critical graphs is
also of interest for at least two topics of polyhedral studies. First,
Chv\'atal (1975) shows that each alpha-critical graph induces a rank inequality
which is facet-defining for its stable set polytope. Investigating a weighted
generalization, Lipt\'ak and Lov\'asz (2000, 2001) introduce critical
facet-graphs (which again produce facet-defining inequalities for their stable
set polytopes) and they establish a finite basis theorem. Second, Koppen (1995)
describes a construction that delivers from any alpha-critical graph a
facet-defining inequality for the linear ordering polytope. Doignon, Fiorini
and Joret (2006) handle the weighted case and thus define facet-defining
graphs. Here we investigate relationships between the two weighted
generalizations of alpha-critical graphs. We show that facet-defining graphs
(for the linear ordering polytope) are obtainable from 1-critical facet-graphs
(linked with stable set polytopes). We then use this connection to derive
various results on facet-defining graphs, the most prominent one being derived
from Lipt\'ak and Lov\'asz's finite basis theorem for critical facet-graphs. At
the end of the paper we offer an alternative proof of Lov\'asz's finite basis
theorem for alpha-critical graphs.


title: Near universal cycles for subsets exist

abstract:
  Let S be a cyclic n-ary sequence. We say that S is a {\it universal cycle}
((n,k)-Ucycle) for k-subsets of [n] if every such subset appears exactly once
contiguously in S, and is a Ucycle packing if every such subset appears at most
once. Few examples of Ucycles are known to exist, so the relaxation to packings
merits investigation. A family {S_n} of (n,k)-Ucycle packings for fixed k is a
near-Ucycle if the length of S_n is $(1-o(1))\binom{n}{k}$. In this paper we
prove that near-(n,k)-Ucycles exist for all k.


title:
Solution Poisson-Boltzmann equation: Application in the Human Neuron
  Membrane

abstract:
  With already demonstrated in previous work the equations that describe the
space dependence of the electric potential are determined by the solution of
the equation of Poisson-Boltzmann. In this work we consider these solutions for
the membrane of the human neuron, using a model simplified for this structure
considering the distribution of electrolytes in each side of the membrane, as
well as the effect of glycocalyx and the lipidic bilayer. It was assumed that
on both sides of the membrane the charges are homogeneously distributed and
that the potential depends only on coordinate z.


title: Universality in percolation of arbitrary Uncorrelated Nested Subgraphs

abstract:
  The study of percolation in so-called {\em nested subgraphs} implies a
generalization of the concept of percolation since the results are not linked
to specific graph process. Here the behavior of such graphs at criticallity is
studied for the case where the nesting operation is performed in an
uncorrelated way. Specifically, I provide an analyitic derivation for the
percolation inequality showing that the cluster size distribution under a
generalized process of uncorrelated nesting at criticality follows a power law
with universal exponent $\gamma=3/2$. The relevance of the result comes from
the wide variety of processes responsible for the emergence of the giant
component that fall within the category of nesting operations, whose outcome is
a family of nested subgraphs.


title:
Controlling Mixing Inside a Droplet by Time Dependent Rigid-body
  Rotation

abstract:
  The use of microscopic discrete fluid volumes (i.e., droplets) as
microreactors for digital microfluidic applications often requires mixing
enhancement and control within droplets. In this work, we consider a
translating spherical liquid droplet to which we impose a time periodic
rigid-body rotation which we model using the superposition of a Hill vortex and
an unsteady rigid body rotation. This perturbation in the form of a rotation
not only creates a three-dimensional chaotic mixing region, which operates
through the stretching and folding of material lines, but also offers the
possibility of controlling both the size and the location of the mixing. Such a
control is achieved by judiciously adjusting the three parameters that
characterize the rotation, i.e., the rotation amplitude, frequency and
orientation of the rotation. As the size of the mixing region is increased,
complete mixing within the drop is obtained.


title: Characterizations of lattice surfaces

abstract:
  We answer a question of Vorobets by showing that the lattice property for
flat surfaces is equivalent to the existence of a positive lower bound for the
areas of affine triangles. We show that the set of affine equivalence classes
of lattice surfaces with a fixed positive lower bound for the areas of
triangles is finite and we obtain explicit bounds on its cardinality. We deduce
several other characterizations of the lattice property.


title:
Experimental Tests of General Relativity: Recent Progress and Future
  Directions

abstract:
  Einstein's general theory of relativity is the standard theory of gravity,
especially where the needs of astronomy, astrophysics, cosmology and
fundamental physics are concerned. As such, this theory is used for many
practical purposes involving spacecraft navigation, geodesy and time transfer.
Here I review the foundations of general relativity, discuss recent progress in
the tests of relativistic gravity, and present motivations for the new
generation of high-accuracy tests of new physics beyond general relativity.
Space-based experiments in fundamental physics are capable today to uniquely
address important questions related to the fundamental laws of nature. I
discuss the advances in our understanding of fundamental physics that are
anticipated in the near future and evaluate the discovery potential of a number
of the recently proposed space-based gravitational experiments.


title: Uncertainty Relations for Shift-Invariant Analog Signals

abstract:
  The past several years have witnessed a surge of research investigating
various aspects of sparse representations and compressed sensing. Most of this
work has focused on the finite-dimensional setting in which the goal is to
decompose a finite-length vector into a given finite dictionary. Underlying
many of these results is the conceptual notion of an uncertainty principle: a
signal cannot be sparsely represented in two different bases. Here, we extend
these ideas and results to the analog, infinite-dimensional setting by
considering signals that lie in a finitely-generated shift-invariant (SI)
space. This class of signals is rich enough to include many interesting special
cases such as multiband signals and splines. By adapting the notion of
coherence defined for finite dictionaries to infinite SI representations, we
develop an uncertainty principle similar in spirit to its finite counterpart.
We demonstrate tightness of our bound by considering a bandlimited lowpass
train that achieves the uncertainty principle. Building upon these results and
similar work in the finite setting, we show how to find a sparse decomposition
in an overcomplete dictionary by solving a convex optimization problem. The
distinguishing feature of our approach is the fact that even though the problem
is defined over an infinite domain with infinitely many variables and
constraints, under certain conditions on the dictionary spectrum our algorithm
can find the sparsest representation by solving a finite-dimensional problem.


title:
Study of the island morphology at the early stages of Fe/Mo(110) MBE
  growth

abstract:
  We present theoretical study of morphology of Fe islands grown at Mo(110)
surface in sub-monolayer MBE mode. We utilize atomistic SOS model with bond
counting, and interactions of Fe adatom up to third nearest neighbors. We
performed KMC simulations for different values of adatom interactions and
varying temperatures. We have found that, while for the low temperature islands
are fat fractals, for the temperature 500K islands have faceted rhombic-like
shape. For the higher temperature, islands acquire a rounded shape. In order to
evaluated qualitatively morphological changes, we measured averaged aspect
ration of islands. We calculated dependence of the average aspect ratio on the
temperature, and on the strength of interactions of an adatom with neighbors.


title:
A measurement of large-scale peculiar velocities of clusters of
  galaxies: technical details

abstract:
  This paper presents detailed analysis of large-scale peculiar motions derived
from a sample of ~ 700 X-ray clusters and cosmic microwave background (CMB)
data obtained with WMAP. We use the kinematic Sunyaev-Zeldovich (KSZ) effect
combining it into a cumulative statistic which preserves the bulk motion
component with the noise integrated down. Such statistic is the dipole of CMB
temperature fluctuations evaluated over the pixels of the cluster catalog
(Kashlinsky & Atrio-Barandela 2000). To remove the cosmological CMB
fluctuations the maps are Wiener-filtered in each of the eight WMAP channels
(Q, V, W) which have negligible foreground component. Our findings are as
follows: The thermal SZ (TSZ) component of the clusters is described well by
the Navarro-Frenk-White profile expected if the hot gas traces the dark matter
in the cluster potential wells. Such gas has X-ray temperature decreasing
rapidly towards the cluster outskirts, which we demonstrate results in the
decrease of the TSZ component as the aperture is increased to encompass the
cluster outskirts. We then detect a statistically significant dipole in the CMB
pixels at cluster positions. Arising exclusively at the cluster pixels this
dipole cannot originate from the foreground or instrument noise emissions and
must be produced by the CMB photons which interacted with the hot intracluster
gas via the SZ effect. The dipole remains as the monopole component, due to the
TSZ effect, vanishes within the small statistical noise out to the maximal
aperture where we still detect the TSZ component. We demonstrate with
simulations that the mask and cross-talk effects are small for our catalog and
contribute negligibly to the measurements. The measured dipole thus arises from
the KSZ effect produced by the coherent large scale bulk flow motion.


title:
A measurement of large-scale peculiar velocities of clusters of
  galaxies: results and cosmological implications

abstract:
  Peculiar velocities of clusters of galaxies can be measured by studying the
fluctuations in the cosmic microwave background (CMB) generated by the
scattering of the microwave photons by the hot X-ray emitting gas inside
clusters. While for individual clusters such measurements result in large
errors, a large statistical sample of clusters allows one to study cumulative
quantities dominated by the overall bulk flow of the sample with the
statistical errors integrating down. We present results from such a measurement
using the largest all-sky X-ray cluster catalog combined to date and the 3-year
WMAP CMB data. We find a strong and coherent bulk flow on scales out to at
least > 300 h^{-1} Mpc, the limit of our catalog. This flow is difficult to
explain by gravitational evolution within the framework of the concordance LCDM
model and may be indicative of the tilt exerted across the entire current
horizon by far-away pre-inflationary inhomogeneities.


title: Star Formation in the Eagle Nebula

abstract:
  M16 (the Eagle Nebula) is a striking star forming region, with a complex
morphology of gas and dust sculpted by the massive stars in NGC 6611. Detailed
studies of the famous ``elephant trunks'' dramatically increased our
understanding of the massive star feedback into the parent molecular cloud. A
rich young stellar population (2 - 3 Myr) has been identified, from massive
O-stars down to substellar masses. Deep into the remnant molecular material,
embedded protostars, Herbig-Haro objects and maser sources bear evidence of
ongoing star formation in the nebula, possibly triggered by the massive cluster
members. M 16 is a excellent template for the study of star formation under the
hostile environment created by massive O-stars. This review aims at providing
an observational overview not only of the young stellar population but also of
the gas remnant of the star formation process.


title: Electric dipole rovibrational transitions in HD molecule

abstract:
  The rovibrational electric dipole transitions in the ground electronic state
of the HD molecule are studied. A simple, yet rigorous formula is derived for
the transition rates in terms of the electric dipole moment function $D(R)$,
which is calculated in a wide range of $R$. Our numerical results for
transition rates are in moderate agreement with experiments and previous
calculations, but are at least an order of magnitude more accurate.


title: BS196: an old star cluster far from the SMC main body

abstract:
  We present B and V photometry of the outlying SMC star cluster BS196 with the
4.1-m SOAR telescope. The photometry is deep (to V~25) showing ~3 mag below the
cluster turnoff point (TO) at Mv=2.5 (1.03 Msun). The cluster is located at the
SMC distance. The CMD and isochrone fittings provide a cluster age of 5.0+-0.5
Gyr, indicating that this is one of the 12 oldest clusters so far detected in
the SMC. The estimated metallicity is [Fe/H]=-1.68+-0.10. The structural
analysis gives by means of King profile fittings a core radius Rc=8.7+-1.1
arcsec (2.66+-0.14 pc) and a tidal radius Rt=69.4+-1.7 arcsec (21.2+-1.2 pc).
BS196 is rather loose with a concentration parameter c=0.90. With
Mv=-1.89+-0.39, BS196 belongs to the class of intrinsically fainter SMC
clusters, as compared to the well-known populous ones, which starts to be
explored.


title: Twisted geometric Satake equivalence

abstract:
  We generalize the classical Satake equivalence as follows. Let k be an
algebraically closed field, set O=k[[t]] and F=k((t)). For an almost simple
algebraic group G we classify central extensions of G(F) by the multiplicative
group. Any such extension E splits canonically over G(O). Consider the category
of G(O)-biinvariant perverse sheaves on E with a given Gm-monodromy . We show
that this is a tensor category, which is tensor equivalent to the category of
representations of a reductive group. We compute the root datum of this group.


title:
Any order imaginary time propagation method for solving the Schrodinger
  equation

abstract:
  The eigenvalue-function pair of the 3D Schr\"odinger equation can be
efficiently computed by use of high order, imaginary time propagators. Due to
the diffusion character of the kinetic energy operator in imaginary time,
algorithms developed so far are at most fourth-order. In this work, we show
that for a grid based algorithm, imaginary time propagation of any even order
can be devised on the basis of multi-product splitting. The effectiveness of
these algorithms, up to the 12$^{\rm th}$ order, is demonstrated by computing
all 120 eigenstates of a model C$_{60}$ molecule to very high precisions. The
algorithms are particularly useful when implemented on parallel computer
architectures.


title:
2MASS wide field extinction maps: II. The Ophiuchus and the Lupus cloud
  complexe

abstract:
  We present an extinction map of a ~1,700 deg sq region that encloses the
Ophiuchus, the Lupus, and the Pipe dark complexes using 42 million stars from
the Two Micron All Sky Survey (2MASS) point source catalog. The use of a robust
and optimal near-infrared method to map dust column density (Nicer, described
in Lombardi & Alves 2001) allow us to detect extinction as low as A_K = 0.05
mag with a 2-sigma significance, and still to have a resolution of 3 arcmin on
our map. We also present a novel, statistically sound method to characterize
the small-scale inhomogeneities in molecular clouds. Finally, we investigate
the cloud structure function, and show that significant deviations from the
results predicted by turbulent models are observed.


title: Infrared Propagators in MAG and Feynman gauge on the lattice

abstract:
  We propose to investigate infrared properties of gluon and ghost propagators
related to the so-called Gribov-Zwanziger confinement scenario, originally
formulated for Landau and Coulomb gauges, for other gauges as well. We present
results of our investigation of SU(2) lattice gauge theory in the maximally
Abelian gauge (MAG), focusing on the behavior of propagators in the
off-diagonal (i.e. non-Abelian) sector. We also comment on our preliminary
results for general linear covariant gauges, in particular for Feynman gauge.


title: Frobenius map for quintic threefolds

abstract:
  We calculate the matrix of the Frobenius map on the middle dimensional
cohomology of the one parameter family that is related by mirror symmetry to
the family of all quintic threefolds.


title: Sivers and Collins effects in polarized pp scattering processes

abstract:
  We summarize the present phenomenology of Sivers and Collins effects for
transverse single spin asymmetries in polarized proton-proton collisions within
the framework of the generalized parton model (GPM). We will discuss a
reassessment of the Collins effect and some preliminary predictions for SSA's
in p(pol) p -> pi,K + X processes at RHIC obtained using updated information
from SIDIS data and a new set of meson fragmentation functions.


title: Aspects of Infrared Modifications of Gravity

abstract:
  In the first part of the thesis, and after an introduction to certain models
of modified gravity, we study consistent Lagrangians for Lorentz invariant
(massive and massless) spin-2 and spin-3/2 particles in flat space. The second
part of the dissertation is devoted to non-linear extensions for the spin-2
case, focusing on unimodular gravity and bigravity. Both theories lead to
modifications of General Relativity at large distances and we will study exact
solutions, causal structure of those solutions, and perturbation theory
(specially for the Lorentz breaking case). Some comments on quantization of
these theories can be found in an appendix.


title: Abundances of Planetary Nebulae NGC3242 and NGC6369

abstract:
  The spectra of the planetary nebulae NGC3242 and NGC6369 are reanalysed using
spectral measurements made in the mid-infrared with the Spitzer Space Telescope
and the Infrared Space Observatory (ISO). The aim is to determine the chemical
composition of these objects. We also make use of International Ultraviolet
Explorer (IUE) and ground based spectra. These elliptical PNe are interesting
because they are well-studied, nearby, bright objects and therefore allow a
reasonably complete comparison of this type of nebulae. Abundances determined
from the mid-infrared lines, which are insensitive to electron temperature, are
used as the basis for the determination of the composition, which are found to
differ somewhat from earlier results. The abundances found, especially the low
value of helium and oxygen, indicate that the central star was originally of
rather low mass. The abundance of phosphorus has been determined for the first
time in NGC3242. The electron temperature in both of these nebulae is roughly
constant unlike NGC6302 and NGC2392 where a strong temperature gradient is
found. The temperature of the central star is discussed for both nebulae.
Finally a comparison of the element abundances in these nebulae with the solar
abundance is made. The low abundance of Fe and P is noted and it is suggested
that these elements are an important constituent of the nebular dust.


title: Viscous Properties of Strongly Interacting Matter at High Temperature

abstract:
  Substantial collective flow is observed in collisions between large nuclei at
high energy, and the data are well-reproduced by perfect fluid dynamics. In a
separate development, calculation of the dimensionless ratio of shear viscosity
$\eta$ to entropy density within AdS/CFT yields $\eta/s = 1/4\pi$, which has
been conjectured to be a lower bound for any physical system. It is shown that
the transition from hadrons to quarks and gluons has behavior similar to
helium, nitrogen, and water at and near their phase transitions in the ratio
$\eta/s$. Conversely, there are indications that the ratio of bulk viscosity
$\zeta$ to entropy density may have a maximum in the vicinity of the phase
transition. Therefore it is possible that experimental measurements can
pinpoint the location of the transition or rapid crossover in QCD via the
ratios $\eta/s$ and $\zeta/s$ in addition to and independently of the equation
of state.


title: System Parameters for the Eclipsing B-Star Binary HD 42401

abstract:
  I present results from an optical spectroscopic investigation of the binary
system HD 42401 (V1388 Ori; B2.5 IV-V + B3 V). A combined analysis of V-band
photometry and radial velocities indicates that the system has an orbital
period of 2.18706 +/- 0.00005 days and an inclination of 75.5 +/- 0.2 degrees.
This solution yields masses and radii of M1 = 7.42 +/- 0.08 Solar Masses and R1
= 5.60 +/- 0.04 Solar Radii for the primary and M2 = 5.16 +/- 0.03 Solar Masses
and R2 = 3.76 +/- 0.03 Solar Radii for the secondary. Based on the position of
the two stars plotted on a theoretical H-R diagram, I find that the age of the
system is > 25 Myr and that both stars appear overluminous for their masses
compared to single star evolutionary tracks. A fit of the spectral energy
distribution based on photometry from the literature yields a distance to HD
42401 of 832 +/- 89 parsecs.


title: Algebras and non-geometric flux vacua

abstract:
  In this work we classify the subalgebras satisfied by non-geometric Q-fluxes
in type IIB orientifolds on T^6/(Z_2 x Z_2) with three moduli (S,T,U). We find
that there are five subalgebras compatible with the symmetries, each one
leading to a characteristic flux-induced superpotential. Working in the
4-dimensional effective supergravity we obtain families of supersymmetric AdS_4
vacua with all moduli stabilized at small string coupling g_s. Our results are
mostly analytic thanks to a judicious parametrization of the non-geometric, RR
and NSNS fluxes. We are also able to leave the flux-induced C_4 and C_8 RR
tadpoles as free variables, thereby enabling us to study which values are
allowed for each Q-subalgebra. Another novel outcome is the appearance of
multiple vacua for special sets of fluxes. However, they generically have g_s >
1 unless the net number of O3/D3 or O7/D7 sources needed to cancel the tadpoles
is large. We also discuss briefly the issues of axionic shift symmetries and
cancellation of Freed-Witten anomalies.


title:
The Growth & Migration of Jovian Planets in Evolving Protostellar Disks
  with Dead Zones

abstract:
  The growth of Jovian mass planets during migration in their protoplanetary
disks is one of the most important problems that needs to be solved in light of
observations of the exosolar planets. Studies of the migration of planets in
standard gas disk models routinely show that migration is too fast to form
Jovian planets, and that such migrating planetary cores generally plunge into
the central stars in less than a Myr. In previous work, we have shown that a
poorly ionized, less viscous region in a protoplanetary disk called a dead zone
slows down the migration of fixed-mass planets. In this paper, we extend our
numerical calculations to include dead zone evolution along with the disk, as
well as planet formation via accretion of rocky and gaseous materials. Using
our symplectic-integrator-gas dynamics code, we find that dead zones, even in
evolving disks wherein migrating planets grow by accretion, still play a
fundamental role in saving planetary systems. We demonstrate that Jovian
planets form within 2.5 Myr for disks that are ten times more massive than a
minimum mass solar nebula (MMSN) with an opacity reduction and without slowing
down migration artificially. Our simulations indicate that protoplanetary disks
with an initial mass comparable to the MMSN only produce Neptunian mass
planets. We also find that planet migration does not help core accretion as
much in the oligarchic planetesimal accretion scenario as it was expected in
the runaway accretion scenario. Therefore we expect that an opacity reduction
(or some other mechanisms) is needed to solve the formation timescale problem
even for migrating protoplanets, as long as we consider the oligarchic growth.
We also point out a possible role of a dead zone in explaining long-lived,
strongly accreting gas disks.


title: Universality in Complex Wishart ensembles: The 2 cut case

abstract:
  We studied the universality of Wishart ensembles whose covariance matrix has
2 distinct eigenvalues. We studied the asymptotic limit when the number of both
eigenvalues goes to infinity and obtained universality results. In this case,
the limiting eigenvalue distribution can be supported on 1 or 2 disjoint
intervals. We obtained a necessary and sufficient condition on the parameters
such that the limiting distribution is supported on 2 disjoint intervals and
have computed the eigenvalue density in the limit. Furthermore, by using
Riemann-Hilbert analysis, we have shown that under proper rescaling of the
eigenvalues, the limiting correlation kernel is given by the sine kernel and
the Airy kernel in the bulk and the edge of the spectrum respectively. As a
consequence, the behavior of the largest eigenvalue in this model is described
by the Tracy-Widom distribution.


title:
Computer simulation of two continuous spin models using
  Wang-Landau-Transition-Matrix Monte Carlo Algorithm

abstract:
  Monte Carlo simulation using a combination of Wang Landau (WL) and Transition
Matrix (TM) Monte Carlo algorithms to simulate two lattice spin models with
continuous energy is described. One of the models, the one dimensional
Lebwohl-Lasher model has an exact solution and we have used this to test the
performance of the mixed algorithm (WLTM). The other system we have worked on
is the two dimensional XY-model. The purpose of the present work is to test the
performance of the WLTM algorithm in continuous models and to suggest methods
for obtaining best results in such systems using this algorithm.


title:
Simulations of the formation of stellar discs in the Galactic centre via
  cloud-cloud collisions

abstract:
  Young massive stars in the central parsec of our Galaxy are best explained by
star formation within at least one, and possibly two, massive self-gravitating
gaseous discs. With help of numerical simulations, we here consider whether the
observed population of young stars could have originated from a large angle
collision of two massive gaseous clouds at R approx. 1 parsec from Sgr A*. In
all the simulations performed, the post-collision gas flow forms an inner,
nearly circular gaseous disc and one or two eccentric outer filaments,
consistent with the observations. Furthermore, the radial stellar mass
distribution is always very steep, Sigma proportional to R^-2, again consistent
with the observations. All of our simulations produce discs that are warped by
between 30 to 60 degrees, in accordance with the most recent observations. The
3D velocity structure of the stellar distribution is sensitive to initial
conditions (e.g., the impact parameter of the clouds) and gas cooling details.
For example, the runs in which the inner disc is fed intermittently with
material possessing fluctuating angular momentum result in multiple stellar
discs with different orbital orientations, contradicting the observed data. In
all the cases the amount of gas accreted by our inner boundary condition is
large, enough to allow Sgr A* to radiate near its Eddington limit over approx.
10^5 years. This suggests that a refined model would have physically larger
clouds (or a cloud and a disc such as the circumnuclear disc) colliding at a
distance of a few parsecs rather than 1 parsec as in our simulations.


title: Polyfolds And A General Fredholm Theory

abstract:
  We survey a very general (nonlinear) Fredholm theory for a new class of
ambient spaces, called polyfolds. This theory is being currently developed
jointly with K. Wysocki and E. Zehnder. The basic feature of these new spaces
is that in general they may have locally varying dimensions. These new spaces
are needed for a functional analytic treatment of nonlinear problems involving
analytic limiting behavior. This theory is applicable to Gromov-Witten and
Floer Theory as well as Symplectic Field Theory.


title: Locally connected models for Julia sets

abstract:
  Let $P$ be a polynomial with a connected Julia set $J$. We use continuum
theory to show that it admits a \emph{finest monotone map $\ph$ onto a locally
connected continuum $J_{\sim_P}$}, i.e. a monotone map $\ph:J\to J_{\sim_P}$
such that for any other monotone map $\psi:J\to J'$ there exists a monotone map
$h$ with $\psi=h\circ \ph$. Then we extend $\ph$ onto the complex plane $\C$
(keeping the same notation) and show that $\ph$ monotonically semiconjugates
$P|_{\C}$ to a \emph{topological polynomial $g:\C\to \C$}. If $P$ does not have
Siegel or Cremer periodic points this gives an alternative proof of Kiwi's
fundamental results on locally connected models of dynamics on the Julia sets,
but the results hold for all polynomials with connected Julia sets. We also
give a criterion and a useful sufficient condition for the map $\ph$ not to
collapse $J$ into a point.


title:
Plasmoids in Reconnecting Current Sheets: Solar and Terrestrial Contexts
  Compared

abstract:
  Magnetic reconnection plays a crucial role in violent energy conversion
occurring in the environments of high electrical conductivity, such as the
solar atmosphere, magnetosphere, and fusion devices. We focus on the
morphological features of the process in two different environments, the solar
atmosphere and the geomagnetic tail. In addition to indirect evidence that
indicates reconnection in progress or having just taken place, such as auroral
manifestations in the magnetosphere and the flare loop system in the solar
atmosphere, more direct evidence of reconnection in the solar and terrestrial
environments is being collected. Such evidence includes the reconnection inflow
near the reconnecting current sheet, and the outflow along the sheet
characterized by a sequence of plasmoids. Both turbulent and unsteady
Petschek-type reconnection processes could account for the observations. We
also discuss other relevant observational consequences of both mechanisms in
these two settings. While on face value, these are two completely different
physical environments, there emerge many commonalities, for example, an Alfven
speed of the same order of magnitude, a key parameter determining the
reconnection rate. This comparative study is meant as a contribution to current
efforts aimed at isolating similarities in processes occurring in very
different contexts in the heliosphere, and even in the universe.


title: Monolithically Patterned Wide-Narrow-Wide All-Graphene Devices

abstract:
  We investigate theoretically the performance advantages of all-graphene
nanoribbon field-effect transistors (GNRFETs) whose channel and source/drain
(contact) regions are patterned monolithically from a two-dimensional single
sheet of graphene. In our simulated devices, the source/drain and interconnect
regions are composed of wide graphene nanoribbon (GNR) sections that are
semimetallic, while the channel regions consist of narrow GNR sections that
open semiconducting bandgaps. Our simulation employs a fully atomistic model of
the device, contact and interfacial regions using tight-binding theory. The
electronic structures are coupled with a self-consistent three-dimensional
Poisson's equation to capture the nontrivial contact electrostatics, along with
a quantum kinetic formulation of transport based on non-equilibrium Green's
functions (NEGF). Although we only consider a specific device geometry, our
results establish several general performance advantages of such monolithic
devices (besides those related to fabrication and patterning), namely the
improved electrostatics, suppressed short-channel effects, and Ohmic contacts
at the narrow-to-wide interfaces.


title:
Electron-capture branch of 100Tc and tests of nuclear wave functions for
  double-beta decays

abstract:
  We present a measurement of the electron-capture branch of $^{100}$Tc. Our
value, $B(\text{EC}) = (2.6 \pm 0.4) \times 10^{-5}$, implies that the
$^{100}$Mo neutrino absorption cross section to the ground state of $^{100}$Tc
is roughly one third larger than previously thought. Compared to previous
measurements, our value of $B(\text{EC})$ prevents a smaller disagreement with
QRPA calculations relevant to double-$\beta$ decay matrix elements.


title: Response of Single Polymers to Localized Step Strains

abstract:
  In this paper, the response of single three-dimensional phantom and
self-avoiding polymers to localized step strains are studied for two cases in
the absence of hydrodynamic interactions: (i) polymers tethered at one end with
the strain created at the point of tether, and (ii) free polymers with the
strain created in the middle of the polymer. The polymers are assumed to be in
their equilibrium state before the step strain is created. It is shown that the
strain relaxes as a power-law in time $t$ as $t^{-\eta}$. While the strain
relaxes as $1/t$ for the phantom polymer in both cases; the self-avoiding
polymer relaxes its strain differently in case (i) than in case (ii): as
$t^{-(1+\nu)/(1+2\nu)}$ and as $t^{-2/(1+2\nu)}$ respectively. Here $\nu$ is
the Flory exponent for the polymer, with value $\approx0.588$ in three
dimensions. Using the mode expansion method, exact derivations are provided for
the $1/t$ strain relaxation behavior for the phantom polymer. However, since
the mode expansion method for self-avoiding polymers is nonlinear, similar
theoretical derivations for the self-avoiding polymer proves difficult to
provide. Only simulation data are therefore presented in support of the
$t^{-(1+\nu)/(1+2\nu)}$ and the $t^{-2/(1+2\nu)}$ behavior. The relevance of
these exponents for the anomalous dynamics of polymers are also discussed.


title: The N2D+/N2H+ ratio as an evolutionary tracer of Class 0 protostars

abstract:
  Deuterated ions are abundant in cold (T=10 K), dense (n=10^5 cm^-3) regions,
in which CO is frozen out onto dust grains. In such environments, the deuterium
fractionation of such ions can exceed the elemental abundance ratio of D/H by a
factor of 10^4. In this paper we use the deuterium fractionation to investigate
the evolutionary state of Class 0 protostars. In a sample of 20 protostellar
objects, we found a clear correlation between the N2D+/N2H+ ratio and
evolutionary tracers. As expected, the coolest, i.e. the youngest, objects show
the largest deuterium fractionation. Furthermore, we find that sources with a
high N2D+/N2H+ ratio show clear indication for infall.


title: The Baryogenesis Window in the MSSM

abstract:
  Electroweak baryogenesis provides an attractive explanation of the origin of
the matter-antimatter asymmetry that relies on physics at the weak scale and
thus it is testable at present and near future high-energy physics experiments.
Although this scenario may not be realized within the Standard Model, it can be
accommodated within the MSSM provided there are new CP-violating phases and the
lightest stop mass is smaller than the top-quark mass. In this work we provide
an evaluation of the values of the stop (m_{\tilde t}) and Higgs (m_H) masses
consistent with the requirements of electroweak baryogenesis based on an
analysis that makes use of the renormalization group improved Higgs and stop
potentials, and including the dominant two-loop effects at high temperature. We
find an allowed window in the (m_{\tilde t},m_H)-plane, consistent with all
present experimental data, where there is a strongly first-order electroweak
phase transition and where the electroweak vacuum is metastable but
sufficiently long-lived. In particular we obtain absolute upper bounds on the
Higgs and stop masses, m_H\lesssim 127 GeV and m_{\tilde t}\lesssim 120 GeV,
implying that this scenario will be probed at the LHC.


title: Can we avoid dark energy?

abstract:
  The idea that we live near the centre of a large, nonlinear void has
attracted attention recently as an alternative to dark energy or modified
gravity. We show that an appropriate void profile can fit both the latest
cosmic microwave background and supernova data. However, this requires either a
fine-tuned primordial spectrum or a Hubble rate so low as to rule these models
out. We also show that measurements of the radial baryon acoustic scale can
provide very strong constraints. Our results present a serious challenge to
void models of acceleration.


title: Climate Science: Is it currently designed to answer questions?

abstract:
  For a variety of inter-related cultural, organizational, and political
reasons, progress in climate science and the actual solution of scientific
problems in this field have moved at a much slower rate than would normally be
possible. Not all these factors are unique to climate science, but the heavy
influence of politics has served to amplify the role of the other factors. Such
factors as the change in the scientific paradigm from a dialectic opposition
between theory and observation to an emphasis on simulation and observational
programs, the inordinate growth of administration in universities and the
consequent increase in importance of grant overhead, and the hierarchical
nature of formal scientific organizations are cosidered. This paper will deal
with the origin of the cultural changes and with specific examples of the
operation and interaction of these factors. In particular, we will show how
political bodies act to control scientific institutions, how scientists adjust
both data and even theory to accommodate politically correct positions, and how
opposition to these positions is disposed of.


title:
Wide bandwidth phase-locked diode laser with an intra-cavity
  electro-optic modulator

abstract:
  Two extended cavity laser diodes are phase-locked, thanks to an intra-cavity
electro-optical modulator. The phase-locked loop bandwidth is on the order of
10 MHz, which is about twice larger than when the feedback correction is
applied on the laser current. The phase noise reaches -120 dBrad$^2$/Hz at 10
kHz. This new scheme reduces the residual laser phase noise, which constitutes
one of the dominant contributions in the sensitivity limit of atom
interferometers using two-photon transitions.


title: Locality and the classical limit of quantum mechanics

abstract:
  I argue that conventional estimates of the criterion for classical behavior
of a macroscopic body are incorrect, because they do not take into account the
locality of interactions, which characterizes the behavior of all systems
described approximately by local quantum field theory. Black holes are the only
localized objects which do not have such a description. The deviations from
classical behavior of a macroscopic body, except for those which can be
described as classical uncertainties in the initial values of macroscopic
variables,are {\it exponentially} small as a function of the volume of the
macro-system in microscopic units.


title: An analogue of the Narasimhan-Seshadri theorem and some applications

abstract:
  We prove an analogue in higher dimensions of the classical
Narasimhan-Seshadri theorem for strongly stable vector bundles of degree 0 on a
smooth projective variety $X$ with a fixed ample line bundle $\Theta$. As
applications, over fields of characteristic zero, we give a new proof of the
main theorem in a recent paper of Balaji and Koll\'ar and derive an effective
version of this theorem; over uncountable fields of positive characteristics,
if $G$ is a simple and simply connected algebraic group and the characteristic
of the field is bigger than the Coxeter index of $G$, we prove the existence of
strongly stable principal $G$ bundles on smooth projective surfaces whose
holonomy group is the whole of $G$.


title: Progenitor mass of the type IIP supernova 2005cs

abstract:
  The progenitor mass of type IIP supernova can be determined from either
hydrodynamic modeling of the event or pre-explosion observations. To compare
these approaches, we determine parameters of the sub-luminous supernova 2005cs
and estimate its progenitor mass. We compute the hydrodynamic models of the
supernova to describe its light curves and expansion velocity data. We estimate
a presupernova mass of 17.3 Msun, an explosion energy of 4.1x10^{50} erg, a
presupernova radius of 600 Rsun, and a radioactive Ni-56 mass of 0.0082 Msun.
The derived progenitor mass of SN 2005cs is 18.2 Msun, which is in-between
those of low-luminosity and normal type IIP supernovae. The obtained progenitor
mass of SN 2005cs is higher than derived from pre-explosion images. The masses
of four type IIP supernovae estimated by means of hydrodynamic modeling are
systematically higher than the average progenitor mass for the 9-25 Msun mass
range. This result, if confirmed for a larger sample, would imply that a
serious revision of the present-day view on the progenitors of type IIP
supernovae is required.


title:
Stochastic and deterministic models for age-structured populations with
  genetically variable traits

abstract:
  Understanding how stochastic and non-linear deterministic processes interact
is a major challenge in population dynamics theory. After a short review, we
introduce a stochastic individual-centered particle model to describe the
evolution in continuous time of a population with (continuous) age and trait
structures. The individuals reproduce asexually, age, interact and die. The
'trait' is an individual heritable property (d-dimensional vector) that may
influence birth and death rates and interactions between individuals, and vary
by mutation. In a large population limit, the random process converges to the
solution of a Gurtin-McCamy type PDE. We show that the random model has a long
time behavior that differs from its deterministic limit. However, the results
on the limiting PDE and large deviation techniques \textit{\`a la}
Freidlin-Wentzell provide estimates of the extinction time and a better
understanding of the long time behavior of the stochastic process. This has
applications to the theory of adaptive dynamics used in evolutionary biology.
We present simulations for two biological problems involving life-history trait
evolution when body size is plastic and individual growth is taken into
account.


title: A note on stability conditions for planar switched systems

abstract:
  This paper is concerned with the stability problem for the planar linear
switched system $\dot x(t)=u(t)A_1x(t)+(1-u(t))A_2x(t)$, where the real
matrices $A_1,A_2\in \R^{2\times 2}$ are Hurwitz and $u(\cdot)
[0,\infty[\to\{0,1\}$ is a measurable function. We give coordinate-invariant
necessary and sufficient conditions on $A_1$ and $A_2$ under which the system
is asymptotically stable for arbitrary switching functions $u(\cdot)$. The new
conditions unify those given in previous papers and are simpler to be verified
since we are reduced to study 4 cases instead of 20. Most of the cases are
analyzed in terms of the function $\Gamma(A_1,A_2)={1/2}(\tr(A_1) \tr(A_2)-
\tr(A_1A_2))$.


title:
Systematic study of the jet fragmentation function for inclusive
  jet-production in p+p collisions at sqrt{s}=200 GeV in STAR

abstract:
  Jet fragmentation functions measured in e^+e^- and p+\bar{p} experiments are
well-described on an inclusive hadron level by QCD-based calculations.
Fragmentation is expected to be modified by the presence of a strongly
interacting medium, but full theoretical description of this modification must
still be developed. It has recently been suggested that particle-identified
fragmentation functions may provide additional insight into the processes
underlying jet quenching. To assess the applicability of QCD-based
fragmentation calculations to RHIC data, and to provide a baseline with which
to compare fragmentation function measurements in heavy ion collisions, we
present the first measurements of charged hadron and particle-identified
fragmentation functions of jets reconstructed via a midpoint-cone algorithm
from p+p collisions at 200 GeV in STAR. We study the dependence on jet
cone-size and jet-energy, and compare the results to PYTHIA simulations based
on the Modified Leading Log Approximation (MLLA).


title: Collision of a sphere onto a wall coated with a liquid film

abstract:
  Particle-particle and particle-wall collisions occur in many natural and
industrial applications such as sedimentation, agglomeration, and granular
flows. To accurately predict the behavior of particulate flows, fundamental
knowledge of the mechanisms of a single collision is required. In this fluid
dynamics video, particle-wall collisions onto a wall coated with 1.5%
poly(ethylene-oxide) (PEO) (viscoelastic liquid) and 80% Glycerol and water
(Newtonian liquid) are shown.


title: Test for reality of algebraic functions

abstract:
  In this paper is proved that a complex algebraic function on complexification
of a real algebraic curve is equivalent to real algebraic function, if and only
if the divisor of preimage of critical values is stable under the involution of
complex conjugation.


title:
An Anomalous Extra Z Prime from Intersecting Branes with Drell-Yan and
  Direct Photons at the LHC

abstract:
  We quantify the impact of gauge anomalies at the Large Hadron Collider by
studying the invariant mass distributions in Drell-Yan and in double prompt
photon, using an extension of the Standard Model characterized by an additional
anomalous U(1) derived from intersecting branes. The approach is rather general
and applies to any anomalous abelian gauge current. Anomalies are cancelled
using either the Wess-Zumino mechanism with suitable Peccei-Quinn-like
interactions and a Stueckelberg axion, or by the Green-Schwarz mechanism. We
compare predictions for the corresponding extra Z-prime to anomaly-free
realizations such as those involving U(1)_{B-L}. We identify the leading
anomalous corrections to both channels, which contribute at higher orders, and
compare them against the next-to-next-to-leading order (NNLO) QCD background.
Anomalous effects in these inclusive observables are found to be very small,
far below the percent level and below the size of the typical QCD corrections
quantified by NNLO K-factors.


title: AdS_4/CFT_3 -- Squashed, Stretched and Warped

abstract:
  We use group theoretic methods to calculate the spectrum of short multiplets
around the extremum of N=8 gauged supergravity potential which possesses N=2
supersymmetry and SU(3) global symmetry. Upon uplifting to M-theory, it
describes a warped product of AdS_4 and a certain squashed and stretched
7-sphere. We find quantum numbers in agreement with those of the gauge
invariant operators in the N=2 superconformal Chern-Simons theory recently
proposed to be the dual of this M-theory background. This theory is obtained
from the U(N)xU(N) theory through deforming the superpotential by a term
quadratic in one of the superfields. To construct this model explicitly, one
needs to employ monopole operators whose complete understanding is still
lacking. However, for the U(2)xU(2) gauge theory we make a proposal for the
form of the monopole operators which has a number of desired properties. In
particular, this proposal implies enhanced symmetry of the U(2)xU(2) ABJM
theory for k=1,2; it makes its similarity to and subtle difference from the BLG
theory quite explicit.


title:
The T=0 random-field Ising model on a Bethe lattice with large
  coordination number: hysteresis and metastable states

abstract:
  In order to elucidate the relationship between rate-independent hysteresis
and metastability in disordered systems driven by an external field, we study
the Gaussian RFIM at T=0 on regular random graphs (Bethe lattice) of finite
connectivity z and compute to O(1/z) (i.e. beyond mean-field) the quenched
complexity associated with the one-spin-flip stable states with magnetization m
as a function of the magnetic field H. When the saturation hysteresis loop is
smooth in the thermodynamic limit, we find that it coincides with the envelope
of the typical metastable states (the quenched complexity vanishes exactly
along the loop and is positive everywhere inside). On the other hand, the
occurence of a jump discontinuity in the loop (associated with an infinite
avalanche) can be traced back to the existence of a gap in the magnetization of
the metastable states for a range of applied field, and the envelope of the
typical metastable states is then reentrant. These findings confirm and
complete earlier analytical and numerical studies.


title:
Self-consistent physical parameters for MC clusters from CMD modelling:
  application to SMC clusters observed with the SOAR telescope

abstract:
  The Magellanic Clouds (MCs) present a rich system of stellar clusters that
can be used to probe the dynamical and chemical evolution of these neighboring
and interacting irregular galaxies. In particular, these stellar clusters (SCs)
present combinations of age and metallicity that are not found for this class
of objects in the Milky Way, being therefore very useful templates to test and
to calibrate integrated light simple stellar population (SSP) models applied to
unresolved distance galaxies. On its turn, the age and metallicity for a
cluster can be determined spatially resolving its stars, by means of analysis
of its colour-magnitude diagrams (CMDs). In this work we present our method to
determine self-consistent physical parameters (age, metallicity, distance
modulus and reddening) for a stellar cluster, from CMDs modelling of relatively
unstudied SCs in the Small Magellanic Cloud (SMC) imaged in the BVI filters
with the 4.1 m SOAR telescope. Our preliminary results confirm our expectations
that come from a previous integrated spectra and colour analysis: at least one
of them (Lindsay 2) is an intermediate-age stellar cluster with ~ 2.6 Gyr and
[Fe/H] ~ -1.3, being therefore a new interesting witness regarding the
reactivation of the star formation in the MCs in the last 4 Gyr.


title:
Charge Renormalization, Effective Interactions, and Thermodynamics of
  Deionized Colloidal Suspensions

abstract:
  Thermodynamic properties of charge-stabilised colloidal suspensions depend
sensitively on the effective charge of the macroions, which can be
substantially lower than the bare charge in the case of strong
counterion-macroion association. A theory of charge renormalization is
proposed, combining an effective one-component model of charged colloids with a
thermal criterion for distinguishing between free and associated counterions.
The theory predicts, with minimal computational effort, osmotic pressures of
deionized suspensions of highly charged colloids in close agreement with
large-scale simulations of the primitive model.


title:
Using Synchronization for Prediction of High-Dimensional Chaotic
  Dynamics

abstract:
  We experimentally observe the nonlinear dynamics of an optoelectronic
time-delayed feedback loop designed for chaotic communication using commercial
fiber optic links, and we simulate the system using delay differential
equations. We show that synchronization of a numerical model to experimental
measurements provides a new way to assimilate data and forecast the future of
this time-delayed high-dimensional system. For this system, which has a
feedback time delay of 22 ns, we show that one can predict the time series for
up to several delay periods, when the dynamics is about 15 dimensional.


title: Optimal Risk Sharing under Distorted Probabilities

abstract:
  We study optimal risk sharing among $n$ agents endowed with distortion risk
measures. Our model includes market frictions that can either represent linear
transaction costs or risk premia charged by a clearing house for the agents.
Risk sharing under third-party constraints is also considered. We obtain an
explicit formula for Pareto optimal allocations. In particular, we find that a
stop-loss or deductible risk sharing is optimal in the case of two agents and
several common distortion functions. This extends recent result of Jouini et
al. (2006) to the problem with unbounded risks and market frictions.


title: Efimov Trimer Formation via Ultracold Four-body Recombination

abstract:
  We discuss the collisional formation of Efimov trimers via ultracold
four-body recombination. In particular, we consider the reaction A+A+A+B->A3+B
with A and B ultracold atoms. We obtain expressions for the four-body
recombination rate and show that it reflects the three-body Efimov physics
either as a function of collision energy or as a function of the two-body
s-wave scattering length between A atoms. In addition, we briefly discuss
issues important for experimentally observing this interesting and relatively
unexplored process.


title: Diresonance in production and scattering of heavy mesons

abstract:
  We consider the production and scattering amplitudes of heavy mesons in a
situation, where there are two closely spaced narrow resonances, which
structure we refer to as a diresonance. Assuming strong overlapping of the
resonances coupled to common channels, it is found, using the unitarity and
analyticity constraints, that the production amplitudes in different channels
should have similar behavior with energy. In particular the ratio of the
coefficients for each pole contribution to the production amplitude is fixed at
-1.


title: Global Search for New Physics with 2.0/fb at CDF

abstract:
  Data collected in Run II of the Fermilab Tevatron are searched for
indications of new electroweak-scale physics. Rather than focusing on
particular new physics scenarios, CDF data are analyzed for discrepancies with
the standard model prediction. A model-independent approach (Vista) considers
gross features of the data, and is sensitive to new large cross-section
physics. Further sensitivity to new physics is provided by two additional
algorithms: a Bump Hunter searches invariant mass distributions for "bumps"
that could indicate resonant production of new particles; and the Sleuth
procedure scans for data excesses at large summed transverse momentum. This
combined global search for new physics in 2.0/fb of ppbar collisions at
sqrt(s)=1.96 TeV reveals no indication of physics beyond the standard model.


title: Ballistic transport in disordered graphene

abstract:
  An analytic theory of electron transport in disordered graphene in a
ballistic geometry is developed. We consider a sample of a large width W and
analyze the evolution of the conductance, the shot noise, and the full
statistics of the charge transfer with increasing length L, both at the Dirac
point and at a finite gate voltage. The transfer matrix approach combined with
the disorder perturbation theory and the renormalization group is used. We also
discuss the crossover to the diffusive regime and construct a ``phase diagram''
of various transport regimes in graphene.


title: Non-Abelian Berry Phases and BPS Monopoles

abstract:
  We study a simple quantum mechanical model of a spinning particle moving on a
sphere in the presence of a magnetic field. The system has two ground states.
As the magnetic field is varied, the ground states mix through a non-Abelian
Berry phase. We show that this Berry phase is the path ordered exponential of
the smooth SU(2) 't Hooft-Polyakov monopole. We further show that, by adjusting
a potential on the sphere, the monopole becomes BPS and obeys the Bogomolnyi
equations. For this choice of potential, it turns out that there is a hidden
supersymmetry underlying the system and the Bogomolnyi equations are analogous
to the tt* equations of Cecotti and Vafa. We conjecture that the Bogomolnyi
equations also govern the Berry phase of N=(2,2) supersymmetric sigma models
with other target spaces.


title:
Galaxy cluster X-ray luminosity scaling relations from a representative
  local sample (REXCESS)

abstract:
  (Abridged) We examine the X-ray luminosity scaling relations of 31 nearby
galaxy clusters from the Representative XMM-Newton Cluster Structure Survey
(REXCESS). The objects are selected in X-ray luminosity only, optimally
sampling the cluster luminosity function; temperatures range from 2 to 9 keV
and there is no bias toward any particular morphological type. Pertinent values
are extracted in an aperture corresponding to R_500, estimated using the tight
correlation between Y_X and total mass. The data exhibit power law relations
between bolometric X-ray luminosity and temperature, Y_X and total mass, all
with slopes that are significantly steeper than self-similar expectations. We
examine the causes for the steepening, finding that the primary driver appears
to be a systematic variation of the gas content with mass. Scatter about the
relations is dominated in all cases by the presence of cool cores. The natural
logarithmic scatter about the raw X-ray luminosity-temperature relation is
about 70%, and about the X-ray luminosity-Y_X relation it is 40%. Cool core and
morphologically disturbed systems occupy distinct regions in the residual space
with respect to the best fitting mean relation, the former lying systematically
to the high luminosity side, the latter to the low luminosity side. Exclusion
of the central regions serves to reduce the scatter by more than 50%. Using Y_X
as a mass proxy, we derive a Malmquist bias corrected luminosity-mass relation
and compare with previous determinations. Our results indicate that luminosity
can be a reliable mass proxy with controllable scatter, which has important
implications for upcoming all-sky cluster surveys, such as those to be
undertaken with Planck and eROSITA, and ultimately for the use of clusters for
cosmological purposes.


title:
HD molecules at high redshift: A low astration factor of deuterium in a
  solar-metallicity DLA system at z=2.418

abstract:
  We present the detection of deuterated molecular hydrogen (HD) in the remote
Universe in a damped Lyman-alpha cloud at zabs=2.418 toward the quasar SDSS
J143912.04+111740.5. This is a unique system in which H2 and CO molecules are
also detected. The chemical enrichment of this gas derived from ZnII and SII is
as high as in the Sun. We measure N(HD)/2 N(H2)=1.5+0.6-0.4 x 10^-5, which is
significantly higher than the same ratio measured in the Galaxy and close to
the primordial D/H ratio estimated from the WMAP constraint on the baryonic
matter density Omega_b. This indicates a low astration factor of deuterium that
contrasts with the unusually high chemical enrichment of the gas. This can be
interpreted as the consequence of an intense infall of primordial gas onto the
associated galaxy. Detection of HD molecules at high-z also opens the
possibility to obtain an independent constraint on the cosmological-time
variability of mu, the proton-to-electron mass ratio.


title:
Wilson Loops in Superconformal Chern-Simons Theory and Fundamental
  Strings in Anti-de Sitter Supergravity Dual

abstract:
  We study Wilson loop operators in three-dimensional, N=6 superconformal
Chern-Simons theory dual to IIA superstring theory on AdS4 x CP3. Novelty of
Wilson loop operators in this theory is that, for a given contour, there are
two linear combinations of Wilson loop transforming oppositely under
time-reversal transformation. We show that one combination is holographically
dual to IIA fundamental string, while orthogonal combination is set to zero. We
gather supporting evidences from detailed comparative study of generalized
time-reversal transformations in both D2-brane worldvolume and ABJM theories.
We then classify supersymmetric Wilson loops and find at most
1/6-supersymmetry. We next study Wilson loop expectation value in planar
perturbation theory. For circular Wilson loop, we find features remarkably
parallel to circular Wilson loop in N=4 super Yang-Mills theory in four
dimensions. First, all odd loop diagrams vanish identically and even loops
contribute nontrivial contributions. Second, quantum corrected gauge and scalar
propagators take the same form as those of N=4 super Yang-Mills theory.
Combining these results, we propose that expectation value of circular Wilson
loop is given by Wilson loop expectation value in pure Chern-Simons theory
times zero-dimensional Gaussian matrix model whose variance is specified by an
interpolating function of `t Hooft coupling. We suggest the function
interpolates smoothly between weak and strong coupling regime, offering new
test ground of the AdS/CFT correspondence.


title: The Magellanic Group and the Seven Dwarfs

abstract:
  The Magellanic Clouds were the largest members of a group of dwarf galaxies
that entered the Milky Way (MW) halo at late times. This group, dominated by
the LMC, contained ~4% of the mass of the Milky Way prior to its accretion and
tidal disruption, but ~70% of the known dwarfs orbiting the MW. Our theory
addresses many outstanding problems in galaxy formation associated with dwarf
galaxies. First, it can explain the planar orbital configuration populated by
some dSphs in the MW. Second, it provides a mechanism for lighting up a subset
of dwarf galaxies to reproduce the cumulative circular velocity distribution of
the satellites in the MW. Finally, our model predicts that most dwarfs will be
found in association with other dwarfs. The recent discovery of Leo V
(Belokurov et al. 2008), a dwarf spheroidal companion of Leo IV, and the nearby
dwarf associations supports our hypothesis.


title: Constraints on the Local Sources of Ultra High-Energy Cosmic Rays

abstract:
  Ultra high-energy cosmic rays (UHECRs) are believed to be protons accelerated
in magnetized plasma outflows of extra-Galactic sources. The acceleration of
protons to ~10^{20} eV requires a source power L>10^{47} erg/s. The absence of
steady sources of sufficient power within the GZK horizon of 100 Mpc, implies
that UHECR sources are transient. We show that UHECR "flares" should be
accompanied by strong X-ray and gamma-ray emission, and that X-ray and
gamma-ray surveys constrain flares which last less than a decade to satisfy at
least one of the following conditions: (i) L>10^{50} erg/s; (ii) the power
carried by accelerated electrons is lower by a factor >10^2 than the power
carried by magnetic fields or by >10^3 than the power in accelerated protons;
or (iii) the sources exist only at low redshifts, z<<1. The implausibility of
requirements (ii) and (iii) argue in favor of transient sources with L>10^{50}
erg/s.


title:
Quasars Are Not Light-Bulbs: Testing Models of Quasar Lifetimes with the
  Observed Eddington Ratio Distribution

abstract:
  We use the observed distribution of Eddington ratios as a function of
supermassive black hole (BH) mass to constrain models of AGN lifetimes and
lightcurves. Given the observed AGN luminosity function, a model for AGN
lifetimes (time above a given luminosity) translates directly to a predicted
Eddington ratio distribution. Models for self-regulated BH growth, in which
feedback produces a 'blowout' decay phase after some peak luminosity (shutting
down accretion) make specific predictions for the lifetimes distinct from those
expected if AGN are simply gas starved (without feedback) and very different
from simple phenomenological 'light bulb' models. Present observations of the
Eddington ratio distribution, spanning 5 decades in Eddington ratio, 3 in BH
mass, and redshifts z=0-1, agree with the predictions of self-regulated models,
and rule out 'light-bulb', pure exponential, and gas starvation models at high
significance. We compare the Eddington ratio distributions at fixed BH mass and
fixed luminosity (both are consistent, but the latter are much less
constraining). We present empirical fits to the lifetime distribution and show
how the Eddington ratio distributions place tight limits on AGN lifetimes at
various luminosities. We use this to constrain the shape of the typical AGN
lightcurve, and provide simple analytic fits. Given independent constraints on
episodic lifetimes, most local BHs must have gained their mass in no more than
a couple of bright episodes, in agreement with merger-driven fueling models.


title:
Intrinsic Ellipticity Correlation of SDSS Luminous Red Galaxies and
  Misalignment with their Host Dark Matter Halos

abstract:
  We investigate the orientation correlation of giant elliptical galaxies by
measuring the intrinsic ellipticity correlation function of 83,773 luminous red
galaxies (LRGs) at redshifts 0.16 -- 0.47 from the Sloan Digital Sky Survey. We
have accurately determined the correlation up to 30 $h^{-1}$Mpc. Luminosity
dependence of the ellipticity correlation is also detected although the error
bars are large, while no evidence is found for its redshift evolution between
$z=0.2$ and $z=0.4$. Then we use a cosmological $N$-body simulation to examine
misalignment between the central LRGs and their parent dark matter halos.
Central and satellite galaxies are assigned to simulated halos by employing a
halo occupation distribution model for the LRGs. The ellipticity correlation is
predicted to have the same shape as but an amplitude about 4 times higher than
our observation if the central LRGs are perfectly aligned with their host
halos. This indicates that the central LRG galaxies are preferentially but not
perfectly aligned with their host halos. With the assumption that there is a
misalignment angle between a central LRG and its host halo which follows a
Gaussian distribution with a zero mean and a width $\sigma_\theta$, we obtain a
tight constraint on the misalignment parameter,
$\sigma_\theta={35.4}^{+4.0}_{-3.3}$ deg. This type of intrinsic ellipticity
correlation, if not corrected, can lead to contamination at 5% level to the
shear power spectrum in weak lensing surveys of limiting magnitude
$R_{AB}=24.5$ if the source central galaxies follow the same misalignment
distribution as the LRGs.


title: Searching for modified growth patterns with tomographic surveys

abstract:
  In alternative theories of gravity, designed to produce cosmic acceleration
at the current epoch, the growth of large scale structure can be modified. We
study the potential of upcoming and future tomographic surveys such as DES and
LSST, with the aid of CMB and supernovae data, to detect departures from the
growth of cosmic structure expected within General Relativity. We employ
parametric forms to quantify the potential time- and scale-dependent variation
of the effective gravitational constant, and the differences between the two
Newtonian potentials. We then apply the Fisher matrix technique to forecast the
errors on the modified growth parameters from galaxy clustering, weak lensing,
CMB, and their cross-correlations across multiple photometric redshift bins. We
find that even with conservative assumptions about the data, DES will produce
non-trivial constraints on modified growth, and that LSST will do significantly
better.


title:
The impact of priors and observables on parameter inferences in the
  Constrained MSSM

abstract:
  We use a newly released version of the SuperBayeS code to analyze the impact
of the choice of priors and the influence of various constraints on the
statistical conclusions for the preferred values of the parameters of the
Constrained MSSM. We assess the effect in a Bayesian framework and compare it
with an alternative likelihood-based measure of a profile likelihood. We employ
a new scanning algorithm (MultiNest) which increases the computational
efficiency by a factor ~200 with respect to previously used techniques. We
demonstrate that the currently available data are not yet sufficiently
constraining to allow one to determine the preferred values of CMSSM parameters
in a way that is completely independent of the choice of priors and statistical
measures. While b->s gamma generally favors large m_0, this is in some contrast
with the preference for low values of m_0 and m_1/2 that is almost entirely a
consequence of a combination of prior effects and a single constraint coming
from the anomalous magnetic moment of the muon, which remains somewhat
controversial. Using an information-theoretical measure, we find that the
cosmological dark matter abundance determination provides at least 80% of the
total constraining power of all available observables. Despite the remaining
uncertainties, prospects for direct detection in the CMSSM remain excellent,
with the spin-independent neutralino-proton cross section almost guaranteed
above sigma_SI ~ 10^{-10} pb, independently of the choice of priors or
statistics. Likewise, gluino and lightest Higgs discovery at the LHC remain
highly encouraging. While in this work we have used the CMSSM as particle
physics model, our formalism and scanning technique can be readily applied to a
wider class of models with several free parameters.


title:
Noncommmutative solitons and kinks in the affine Toda model coupled to
  matter

abstract:
  Some properties of the non-commutative (NC) versions of the generalized
sine-Gordon model (NCGSG) and its dual massive Thirring theory are studied. Our
method relies on the NC extension of integrable models and the master
lagrangian approach to deal with dual theories. The master lagrangian turns out
to be the NC version of the so-called affine Toda model coupled to matter
related to the group GL(n), in which the Toda field $g \subset GL(n), (n=2,
3)$. Moreover, as a reduction of GL(3) NCGSG one gets a NC version of the
remarkable double sine-Gordon model.


title: Broken scale invariance, massless dilaton and confinement in QCD

abstract:
  Classical conformal invariance of QCD in the chiral limit is broken
explicitly by scale anomaly. As a result, the lightest scalar particle (scalar
glueball, or dilaton) in QCD is not light, and cannot be described as a
Goldstone boson. Nevertheless basing on an effective low-energy theory of
broken scale invariance we argue that inside the hadrons the non-perturbative
interactions of gluon fields result in the emergence of a massless dilaton
excitation (which we call the "scalaron"). We demonstrate that our effective
theory of broken scale invariance leads to confinement. This theory allows a
dual formulation as a classical Yang-Mills theory on a curved conformal
space-time background. Possible applications are discussed, including the
description of strongly coupled quark-gluon plasma and the spin structure of
hadrons.


title:
Radial structure, inflow & central mass of stationary radiative galaxy
  clusters

abstract:
  We analyse the radial structure of self-gravitating spheres consisting of
multiple interpenetrating fluids, such as the X-ray emitting gas and the dark
halo of a galaxy cluster. In these dipolytropic models, adiabatic dark matter
sits in equilibrium, while the gas develops a gradual, smooth, quasi-stationary
cooling flow. Both affect and respond to the collective gravitational field. We
find that all subsonic, radially continuous, steady solutions require a
non-zero minimum central point mass. For Mpc-sized halos with 7 to 10 effective
degrees of freedom (F2), the minimum central mass is compatible with
observations of supermassive black holes. Smaller gas mass influxes enable
smaller central masses for wider ranges of F2. The halo comprises a sharp spike
around the central mass, embedded within a core of nearly constant density (at
10-10^2.5kpc scales), with outskirts that attenuate and naturally truncate at
finite radius (several Mpc). The gas density resembles a broken power law in
radius, but the temperature dips and peaks within the dark core. A finite
minimum temperature occurs due to gravitational self-warming, without cold mass
dropout nor needing regulatory heating. X-ray emission from the intracluster
medium mimics a beta-model plus bright compact nucleus. Near-sonic points in
the gas flow are bottlenecks to allowed steady solutions; the outermost are at
kpc scales. These sites may preferentially develop cold mass dropout during
strong perturbations off equilibrium. Within the sonic point, the profile of
gas specific entropy is flatter than s r^{1/2}, but this is a shallow ramp and
not an isentropic core. When F2 is large, the inner halo spike is only
marginally Jeans stable in the central pc, suggesting that a large non-linear
disturbance could trigger local dark collapse onto the central object.


title: Electronic conduction in a three-terminal molecular transistor

abstract:
  The electronic conduction of a novel, three-terminal molecular architecture,
analogous to a heterojunction bipolar transistor is studied. In this
architecture, two diode arms consisting of donor-acceptor molecular wires fuse
through a ring, while a gate modulating wire is a \pi-conjugated wire. The
calculated results show the enhancement or depletion mode of a transistor by
applying a gate field along the positive or negative direction. A small gate
field is required to switch on the current in the proposed architecture. The
changes in the electronic conduction can be attributed to the intrinsic dipolar
molecular architecture in terms of the evolution of molecular wavefunctions,
specifically the one associated with the terphenyl group of the modulating wire
in the presence of the gate field.


title: A simple proof of Hardy-Lieb-Thirring inequalities

abstract:
  We give a short and unified proof of Hardy-Lieb-Thirring inequalities for
moments of eigenvalues of fractional Schroedinger operators. The proof covers
the optimal parameter range. It is based on a recent inequality by Solovej,
Soerensen, and Spitzer. Moreover, we prove that any non-magnetic Lieb-Thirring
inequality implies a magnetic Lieb-Thirring inequality (with possibly a larger
constant).


title: Kinesin and the Crooks fluctuation theorem

abstract:
  The thermal efficiency of the kinesin cycle at stalling is presently a matter
of some debate, with published predictions ranging from 0 (A. W. C. Lau, D.
Lacoste and K. Mallick, Phys. Rev. Lett. 99, 158102 (2007); D. Lacoste, A. W.
C. Lau and K. Mallick, Phys. Rev. E78, 011915 (2008)) to 100% (G. Oster and H.
Wang, in Molecular Motors, edited by M. Schliwa (Wiley-VCH Verlag GmbH,
Weinheim (2003), p. 207). In this note we attemp to clarify the issues
involved. We also find an upper bound on the kinesin efficieny by constructing
an ideal kinesin cycle to which the real cycle may be compared. The ideal cycle
has a thermal efficiency of less than one, and the real one is less efficient
than the ideal one always, in compliance with Carnot's theorem.


title: DC four point resistance of a double barrier quantum pump

abstract:
  We investigate the behavior of the dc voltage drop in a periodically driven
double barrier structure (DBS) sensed by voltages probes that are weakly
coupled to the system. We find that the four terminal resistance $R_{4t}$
measured with the probes located outside the DBS results identical to the
resistance measured in the same structure under a stationary bias voltage
difference between left and right reservoirs. This result, valid beyond the
adiabatic pumping regime, can be taken as an indication of the universal
character of $R_{4t}$ as a measure of the resistive properties of a sample,
irrespectively of the mechanism used to induce the transport.


title: Quantum stabilization of 1/3-magnetization plateau in Cs_2CuBr_4

abstract:
  We consider the phase diagram of a spatially anisotropic 2D triangular
antiferromagnet in a magnetic field. Classically, the ground state is
umbrella-like for all fields, but we show that the quantum phase diagram is
much richer and contains a 1/3 magnetization plateau, two commensurate planar
states, two incommensurate chiral umbrella phases, and, possibly, a planar
state separating the two chiral phases. Our analysis sheds light on several
recent experimental findings for the spin-1/2 system Cs_2CuBr_4.


title: Vrijhk Photometry of PKS 0537-441 and PKS 2155-304 in 2006-2008

abstract:
  We report the 2006-2008 light curves obtained with the REM telescope in
VRIJHK bands for the two BL Lac objects PKS 0537-441 and PKS 2155-304


title:
Atomic Fluorescence and Prospects for Observing Magnetic Geometry Using
  Atomic Magnetic Realignment

abstract:
  Yan and Lazarian have proposed a new technique through which the magnetic
field geometry in the diffuse interstellar medium, or in circumstellar matter,
could be determined from the linear polarization of interstellar absorption or
fluorescence emission lines from ions pumped by an anisotropic illuminating
flux. New long-slit spectroscopic observations of the reflection nebula
NGC2023, obtained with the Southern African Large Telescope Robert Stobie
Spectrograph (RSS), have detected a number of atomic fluorescence lines of OI,
NI, SiII, and FeII for the first time in a neutral medium. A model which
predicts these lines and others illustrates which lines would be appropriate
targets for an RSS spectropolarimetric investigation of this new diagnostic.


title:
Survival tree and meld to predict long term survival in liver
  transplantation waiting list

abstract:
  Background: Many authors have described MELD as a predictor of short-term
mortality in the liver transplantation waiting list. However MELD score
accuracy to predict long term mortality has not been statistically evaluated.
Objective: The aim of this study is to analyze the MELD score as well as other
variables as a predictor of long-term mortality using a new model: the Survival
Tree analysis. Study Design and Setting: The variables obtained at the time of
liver transplantation list enrollment and considered in this study are: sex,
age, blood type, body mass index, etiology of liver disease, hepatocellular
carcinoma, waiting time for transplant and MELD. Mortality on the waiting list
is the outcome. Exclusion, transplantation or still in the transplantation list
at the end of the study are censored data. Results: The graphical
representation of the survival trees showed that the most statistically
significant cut off is related to MELD score at point 16. Conclusion: The
results are compatible with the cut off point of MELD indicated in the clinical
literature.


title:
Parametrization of the $\bar PP$ Elastic Scattering Differential Cross
  Section Between 2 GeV/c $\leq P_{lab}\leq$ 16 GeV/c

abstract:
  A parameterization of the $\bar pp$ differential elastic scattering cross
section in the beam momentum range from 2 to 16 GeV/c is proposed. The
parameterization well describes the existing data including the observed
diffraction pattern at four-momentum transfer $|t|$ up to 1.5-2.0 GeV$^2$. It
can be used for detailed calculations of the radiation load on the detectors
being designed for the PANDA detector at the future FAIR facility in Darmstadt.


title: New fits to the reaction $\gamma p\to K^+\Lambda$

abstract:
  The reaction $\gamma p\to K^+\Lambda$ has been investigated over the
center-of-momentum energy, $W$, range from threshold up to 2.2 GeV in a
tree-level effective Lagrangian model that incorporates most of the
well-established baryon resonances with spins equal to or below 5/2. Four less
well-established nucleon resonances of higher mass are also included. The
fitted parameters consist, for each resonance included, of the products of the
coupling strengths at the electromagnetic and strong interaction vertices and,
for the less-established nucleon resonances, the total decay width. For the
well-established nucleon resonances, the energy and momentum dependence of the
widths is treated within a dynamical model that is normalized to give the
empirical decay branching ratios on the resonance mass shells. For the
less-established resonances, the total decay width is treated as a single
parameter independent of the reaction kinematics. The model is used to fit
recent data for the unpolarized differential cross section (CLAS), the induced
hyperon polarization asymmetry, $P$ (CLAS, GRAAL, and SAPHIR), the beam spin
asymmetry, $\Sigma$ (LEPS), and the double polarization observables $C_x$ and
$C_z$ (CLAS). Two different fits were obtained: one that incorporates SU(3)
symmetry constraints on the Born contributions to the reaction amplitude and
one in which these constraints are relaxed. Explicit numerical results are
given only for the first fit since the two fits gave nearly identical results
for the observables and the $\chi^2$ per degree of freedom obtained with the
second fit was only marginally better than that of the first fit ($<1%$
better). Results are presented for the fitted observables at several different
energies and center-of-momentum (c.m.) frame kaon angles.