title: New results on lower bounds for the number of (at most k)-facets

abstract:
  In this paper we present three different results dealing with the number of
$(\leq k)$-facets of a set of points:
  1. We give structural properties of sets in the plane that achieve the
optimal lower bound $3\binom{k+2}{2}$ of $(\leq k)$-edges for a fixed $0\leq
k\leq \lfloor n/3 \rfloor -1$;
  2. We give a simple construction showing that the lower bound
$3\binom{k+2}{2}+3\binom{k-\lfloor \frac{n}{3} \rfloor+2}{2}$ for the number of
$(\leq k)$-edges of a planar point set appeared in [Aichholzer et al. New lower
bounds for the number of ($\leq k$)-edges and the rectilinear crossing number
of $K_n$. {\em Disc. Comput. Geom.} 38:1 (2007), 1--14] is optimal in the range
$\lfloor n/3 \rfloor \leq k \leq \lfloor 5n/12 \rfloor -1$;
  3. We show that for $k < \lfloor n/(d+1) \rfloor$ the number of $(\leq
k)$-facets of a set of $n$ points in general position in $\mathbb{R}^d$ is at
least $(d+1)\binom{k+d}{d}$, and that this bound is tight in the given range of
$k$.


title:
Lumped and Distributed Parameter SPICE Models of TE Devices Considering
  Temperature Dependent Material Properties

abstract:
  Based on simplified one-dimensional steady-state analysis of thermoelectric
phenomena and on analogies between thermal and electrical domains, we propose
both lumped and distributed parameter electrical models for thermoelectric
devices. For lumped parameter models, constant values for material properties
are extracted from polynomial fit curves evaluated at different module
temperatures (hot side, cold side, average, and mean module temperature). For
the case of distributed parameter models, material properties are calculated
according to the mean temperature at each segment of a sectioned device. A
couple of important advantages of the presented models are that temperature
dependence of material properties is considered and that they can be easily
simulated using an electronic simulation tool such as SPICE. Comparisons are
made between SPICE simulations for a single-pellet module using the proposed
models and with numerical simulations carried out with Mathematica software.
Results illustrate accuracy of the distributed parameter models and show how
inappropriate is to assume, in some cases, constant material parameters for an
entire thermoelectric element.


title:
A Modular High-Temperature Measurement Set-Up for Semiconductor Device
  Characterization

abstract:
  We demonstrate the capabilities of a high temperature measurement set-up
recently developed at our institute. It is dedicated to the characterization of
semiconductor devices and test structures in the temperature range from room
temperature up to 500 degrees C and higher. A detailed description of the
experimental aquipment is given. Its practical use is demonstrated by measuring
temperature-dependent charcteristics of silicon VDMOSFET and IGBT devices as
well as SiC-diodes. For the silicon devices, numerical simulations based on
recently developed high temperature physical models were also performed in
order to gain a deeper understanding of the measured data, together with a
revalidation of the model parameters.


title: Numerical simulations of the Warm-Hot Intergalactic Medium

abstract:
  In this paper we review the current predictions of numerical simulations for
the origin and observability of the warm hot intergalactic medium (WHIM), the
diffuse gas that contains up to 50 per cent of the baryons at z~0. During
structure formation, gravitational accretion shocks emerging from collapsing
regions gradually heat the intergalactic medium (IGM) to temperatures in the
range T~10^5-10^7 K. The WHIM is predicted to radiate most of its energy in the
ultraviolet (UV) and X-ray bands and to contribute a significant fraction of
the soft X-ray background emission. While O VI and C IV absorption systems
arising in the cooler fraction of the WHIM with T~10^5-10^5.5 K are seen in
FUSE and HST observations, models agree that current X-ray telescopes such as
Chandra and XMM-Newton do not have enough sensitivity to detect the hotter
WHIM. However, future missions such as Constellation-X and XEUS might be able
to detect both emission lines and absorption systems from highly ionised atoms
such as O VII, O VIII and Fe XVII.


title: Improvements of the Variable Thermal Resistance

abstract:
  A flat mounting unit with electronically variable thermal resistance [1] has
been presented in the last year [2]. The design was based on a Peltier cell and
the appropriate control electronics and software. The device is devoted
especially to the thermal characterization of packages, e.g. in dual cold plate
arrangements. Although this design meets the requirements of the static
measurement we are intended to improve its parameters as the settling time and
dynamic thermal impedance and the range of realized thermal resistance. The new
design applies the heat flux sensor developed by our team as well [3], making
easier the control of the device. This development allows even the realization
of negative thermal resistances.


title: Joule Expansion Imaging Techniques on Microlectronic Devices

abstract:
  We have studied the electrically induced off-plane surface displacement on
two microelectronic devices using Scanning Joule Expansion Microscopy (SJEM).
We present the experimental method and surface displacement results. We show
that they can be successfully compared with surface displacement images
obtained using an optical interferometry method. We also present thermal images
using Scanning Thermal Microscopy (SThM) technique to underline that SJEM is
more adapted to higher frequency measurements, which should improve the spatial
resolution.


title:
On narrowing coated conductor film: emergence of granularity-induced
  field hysteresis of transport critical current

abstract:
  Critical current density Jc in polycrystalline or granular superconducting
material is known to be hysteretic with applied field H due to the focusing of
field within the boundary between adjacent grains. This is of concern in the
so-called coated conductors wherein superconducting film is grown on a
granular, but textured surface of a metal substrate. While previous work has
mainly been on Jc determined using induced or magnetization currents, the
present work utilizes transport current via an applied potential in strip
geometry. It is observed that the effect is not as pronounced using transport
current, probably due to a large difference in criterion voltage between the
two types of measurements. However, when the films are narrowed by patterning
into 200-, 100-, or 80-micron, the hysteresis is clearly seen, because of the
forcing of percolation across higher-angle grain boundaries. This effect is
compared for films grown on ion-beam-assisted-deposited (IBAD) YSZ substrate
and those grown on rolling-assisted-biaxially-textures substrates (RABiTS)
which have grains that are about ten times larger. The hysteresis is more
pronounced for the latter, which is more likely to have a weak grain boundary
spanning the width of the microbridge. This is also of concern to applications
in which coated conductors will be striated in order to reduce of AC losses.


title: Evaluation of Cooling Solutions for Outdoor Electronics

abstract:
  The thermal management of an outdoor electronic enclosure can be quite
challenging due to the additional thermal load from the sun and the requirement
of having an air-sealed enclosure. It is essential to consider the effect of
solar heating loads in the design process; otherwise, it can shorten the life
expectancy of the electronic product or lead to catastrophic failure. In this
paper we analyze and compare the effectiveness of different cooling techniques
used for outdoor electronics. Various cooling techniques were compared like
special coatings and paints on the outer surface, radiation shields,
double-walled vented enclosures, fans for internal air circulation and
air-to-air heat exchangers. A highly simplified, typical outdoor system was
selected for this study measuring approximately 300x300x400 mm (WxLxH). Solar
radiation was incident on 3 sides of the enclosure. There were 8 equally spaced
PCBs inside the enclosure dissipating 12.5W each uniformly (100 watts total). A
computational fluid dynamics (CFD) model of the system was built and analyzed.
This was followed by building a mock-up of the system and conducting
experiments to validate the CFD model. It was found that some of the simplest
cooling techniques like white oil paint on the outer surface can significantly
reduce the impact of solar loads. Adding internal circulation fans can also be
very effective. Using air-to-air heat exchangers was found to be the most
effective solution although it is more complex and costly.


title: A New Methodology for Extraction of Dynamic Compact Thermal Models

abstract:
  An innovative and accurate dynamic Compact Thermal Model extraction method is
proposed for multi-chip power electronics systems. It accounts for thermal
coupling between multiple heat sources. Transient electro-thermal coupling can
easily be taken into account by system designers. The method is based on a
definition of the Optimal Thermal Coupling Point, which is proven to be valid
even for transient modelling. Compared to the existing methods, the number of
needed 3D thermal simulations or measurements is significantly reduced.


title: Flexible profile approach to the conjugate heat transfer problem

abstract:
  The flexible profile approach proposed earlier to create CTM (compact or
reduced order thermal models) is extended to cover the area of conjugate heat
transfer. The flexible profile approach is a methodology that allows building a
highly boundary conditions independent CTM, with any desired degree of
accuracy, that may adequately replace detailed 3D models for the whole spectrum
of applications in which the modeled object may be used. The extension to
conjugate problems radically solves the problem of interfacing two different
domains. Each domain, fluid or solid, can be "compacted" independently creating
two CTM that can be joined together to produce reliable results for any
arbitrary set of external boundary conditions.


title: High Performance Thermal Interface Technology Overview

abstract:
  An overview on recent developments in thermal interfaces is given with a
focus on a novel thermal interface technology that allows the formation of 2-3
times thinner bondlines with strongly improved thermal properties at lower
assembly pressures. This is achieved using nested hierarchical surface channels
to control the particle stacking with highly particle-filled materials.
Reliability testing with thermal cycling has also demonstrated a decrease in
thermal resistance after extended times with longer overall lifetime compared
to a flat interface.


title: A Novel Thermal Position Sensor Integrated On A Plastic Substrate

abstract:
  A thermal position sensor was fabricated and evaluated. The device consists
of an array of temperature sensing elements, fabricated entirely on a plastic
substrate. A novel fabrication technology was implemented which allows direct
integration with read out electronics and communication to the macro-world
without the use of wire bonding. The fabricated sensing elements are
temperature sensitive Pt resistors with an average TCR of 0.0024/C. The device
realizes the detection of the position and the motion of a heating source by
monitoring the resistance variation of the thermistor array. The application
field of such a cost-effective position sensor is considered quite extensive.


title: Non-thermal processes in cosmological simulations

abstract:
  Non-thermal components are key ingredients for understanding clusters of
galaxies. In the hierarchical model of structure formation, shocks and
large-scale turbulence are unavoidable in the cluster formation processes.
Understanding the amplification and evolution of the magnetic field in galaxy
clusters is necessary for modelling both the heat transport and the dissipative
processes in the hot intra-cluster plasma. The acceleration, transport and
interactions of non-thermal energetic particles are essential for modelling the
observed emissions. Therefore, the inclusion of the non-thermal components will
be mandatory for simulating accurately the global dynamical processes in
clusters. In this review, we summarise the results obtained with the
simulations of the formation of galaxy clusters which address the issues of
shocks, magnetic field, cosmic ray particles and turbulence.


title: Advancement of Multifunctional support structure technologies (AMFSST)

abstract:
  The multifunctional support structure (MFSS) technology is promising a
reduction of overall mass and packing volume for spacecraft (S/C) electronic
components. This technology eliminates the electronic box chassis and the
cabling between the boxes by integrating the electronics, thermal control and
the structural support into one single element. The ultimate goal of the MFSS
technology is to reduce size, weight, power consumption, cost and production
time for future spacecraft components. The paper focus on the main challenges
and solutions related to the thermal management within the MFSS technology
based on the selected charge regulator (CR) application. Starting with the main
set of thermal requirements for the CR the paper will include, conceptual and
detailed design based on highconductivity carbon fibre CFRP, description and
results of the thermal material sample test program ; parameter and results for
the performed first thermal simulation


title: Moderate deviations for random fields and random complex zeroes

abstract:
  Moderate deviations for random complex zeroes are deduced from a new theorem
on moderate deviations for random fields.


title: Spectra of accretion discs around white dwarfs

abstract:
  We present spectra of accretion discs around white-dwarfs calculated with an
improved and updated version of the Shaviv & Wehrse (1991) model. The new
version includes line opacities and convective energy transport and can be used
to calculate spectra of hot discs in bright systems (nova--like variables or
dwarf novae in outburst) as well as spectra of cold accretion discs in
quiescent dwarf novae.


title: Observations of metals in the intra-cluster medium

abstract:
  Because of their deep gravitational potential wells, clusters of galaxies
retain all the metals produced by the stellar populations of the member
galaxies. Most of these metals reside in the hot plasma which dominates the
baryon content of clusters. This makes them excellent laboratories for the
study of the nucleosynthesis and chemical enrichment history of the Universe.
Here we review the history, current possibilities and limitations of the
abundance studies, and the present observational status of X-ray measurements
of the chemical composition of the intra-cluster medium. We summarise the
latest progress in using the abundance patterns in clusters to put constraints
on theoretical models of supernovae and we show how cluster abundances provide
new insights into the star-formation history of the Universe.


title: Gauge Theory RG Flows from a Warped Resolved Orbifold

abstract:
  We study gauge-string duality of D3-branes localized at a point on the
resolution of the ALE orbifold $\IC^3/\IZ_3$. By explicitly solving for the
warp factor, we demonstrate the holographic RG flow from $AdS_5 \times
S^5/\IZ_3$ (far away from the resolution) to the usual $AdS_5\times S^5$ (close
to the stack). On the gauge theory side, this maps to the flow between the
quiver gauge theory and ${\cal N}=4$ super Yang-Mills. We present two possible
scenarios for this RG flow depending on the choice of the VEVs. In particular,
one of the scenarios proceeds by two steps involving both Higgsing and
confinement.


title:
Conjectural estimates on the Mordell-Weil and Tate-Shafarevich groups of
  an abelian variety

abstract:
  We consider an abelian variety defined over a number field. We give
conditional bounds for the order of its Tate-Shafarevich group, as well as
conditional bounds for the N\'eron-Tate height of generators of its
Mordell-Weil group. The bounds are implied by strong but nowadays classical
conjectures, such as the Birch and Swinnerton-Dyer conjecture and the
functional equation of the L-series. In particular, we improve and generalise a
result by D. Goldfeld and L. Szpiro on the order of the Tate-Shafarevich group,
and extends a conjecture of S. Lang on the canonical height of a system of
generators of the free part of the Mordell-Weil group. The method is an
extension of the algorithm proposed by Yu. Manin for finding a basis for the
non-torsion rational points of an elliptic curve defined over the rationals.


title: q-breathers in Discrete Nonlinear Schroedinger lattices

abstract:
  $q$-breathers are exact time-periodic solutions of extended nonlinear systems
continued from the normal modes of the corresponding linearized system. They
are localized in the space of normal modes. The existence of these solutions in
a weakly anharmonic atomic chain explained essential features of the
Fermi-Pasta-Ulam (FPU) paradox. We study $q$-breathers in one- two- and
three-dimensional discrete nonlinear Sch\"{o}dinger (DNLS) lattices --
theoretical playgrounds for light propagation in nonlinear optical waveguide
networks, and the dynamics of cold atoms in optical lattices. We prove the
existence of these solutions for weak nonlinearity. We find that the
localization of $q$-breathers is controlled by a single parameter which depends
on the norm density, nonlinearity strength and seed wave vector. At a critical
value of that parameter $q$-breathers delocalize via resonances, signaling a
breakdown of the normal mode picture and a transition into strong mode-mode
interaction regime. In particular this breakdown takes place at one of the
edges of the normal mode spectrum, and in a singular way also in the center of
that spectrum. A stability analysis of $q$-breathers supplements these
findings. For three-dimensional lattices, we find $q$-breather vortices, which
violate time reversal symmetry and generate a vortex ring flow of energy in
normal mode space.


title: Very Fast Chip-level Thermal Analysis

abstract:
  We present a new technique of VLSI chip-level thermal analysis. We extend a
newly developed method of solving two dimensional Laplace equations to thermal
analysis of four adjacent materials on a mother board. We implement our
technique in C and compare its performance to that of a commercial CAD tool.
Our experimental results show that our program runs 5.8 and 8.9 times faster
while keeping smaller residuals by 5 and 1 order of magnitude, respectively.


title: On completely positive non-Markovian evolution of a d-level system

abstract:
  A sufficient condition for non-Markovian master equation which ensures the
complete positivity of the resulting time evolution is presented.


title:
Thermal And Mechanical Analysis of High-power Light-emitting Diodes with
  Ceramic Packages

abstract:
  In this paper we present the thermal and mechanical analysis of high-power
light-emitting diodes (LEDs) with ceramic packages. Transient thermal
measurements and thermo-mechanical simulation were performed to study the
thermal and mechanical characteristics of ceramic packages. Thermal resistance
from the junction to the ambient was decreased from 76.1 oC/W to 45.3 oC/W by
replacing plastic mould to ceramic mould for LED packages. Higher level of
thermo-mechanical stresses in the chip were found for LEDs with ceramic
packages despite of less mismatching coefficients of thermal expansion
comparing with plastic packages. The results suggest that the thermal
performance of LEDs can be improved by using ceramic packages, but the mounting
process of the high power LEDs with ceramic packages is critically important
and should be in charge of delaminating interface layers in the packages.


title: Lower bounds for measurable chromatic numbers

abstract:
  The Lovasz theta function provides a lower bound for the chromatic number of
finite graphs based on the solution of a semidefinite program. In this paper we
generalize it so that it gives a lower bound for the measurable chromatic
number of distance graphs on compact metric spaces.
  In particular we consider distance graphs on the unit sphere. There we
transform the original infinite semidefinite program into an infinite linear
program which then turns out to be an extremal question about Jacobi
polynomials which we solve explicitly in the limit. As an application we derive
new lower bounds for the measurable chromatic number of the Euclidean space in
dimensions 10,..., 24, and we give a new proof that it grows exponentially with
the dimension.


title: On the Period of a Periodic-Finite-Type Shift

abstract:
  Periodic-finite-type shifts (PFT's) form a class of sofic shifts that
strictly contains the class of shifts of finite type (SFT's). In this paper, we
investigate how the notion of "period" inherent in the definition of a PFT
causes it to differ from an SFT, and how the period influences the properties
of a PFT.


title: Metal enrichment processes

abstract:
  There are many processes that can transport gas from the galaxies to their
environment and enrich the environment in this way with metals. These metal
enrichment processes have a large influence on the evolution of both the
galaxies and their environment. Various processes can contribute to the gas
transfer: ram-pressure stripping, galactic winds, AGN outflows, galaxy-galaxy
interactions and others. We review their observational evidence, corresponding
simulations, their efficiencies, and their time scales as far as they are known
to date. It seems that all processes can contribute to the enrichment. There is
not a single process that always dominates the enrichment, because the
efficiencies of the processes vary strongly with galaxy and environmental
properties.


title: The chemical enrichment of the ICM from hydrodynamical simulations

abstract:
  The study of the metal enrichment of the intra-cluster and inter-galactic
media (ICM and IGM) represents a direct means to reconstruct the past history
of star formation, the role of feedback processes and the gas-dynamical
processes which determine the evolution of the cosmic baryons. In this paper we
review the approaches that have been followed so far to model the enrichment of
the ICM in a cosmological context. While our presentation will be focused on
the role played by hydrodynamical simulations, we will also discuss other
approaches based on semi-analytical models of galaxy formation, also critically
discussing pros and cons of the different methods. We will first review the
concept of the model of chemical evolution to be implemented in any
chemo-dynamical description. We will emphasise how the predictions of this
model critically depend on the choice of the stellar initial mass function, on
the stellar life-times and on the stellar yields. We will then overview the
comparisons presented so far between X-ray observations of the ICM enrichment
and model predictions. We will show how the most recent chemo-dynamical models
are able to capture the basic features of the observed metal content of the ICM
and its evolution. We will conclude by highlighting the open questions in this
study and the direction of improvements for cosmological chemo-dynamical models
of the next generation.


title: Modeling Online Reviews with Multi-grain Topic Models

abstract:
  In this paper we present a novel framework for extracting the ratable aspects
of objects from online user reviews. Extracting such aspects is an important
challenge in automatically mining product opinions from the web and in
generating opinion-based summaries of user reviews. Our models are based on
extensions to standard topic modeling methods such as LDA and PLSA to induce
multi-grain topics. We argue that multi-grain models are more appropriate for
our task since standard models tend to produce topics that correspond to global
properties of objects (e.g., the brand of a product type) rather than the
aspects of an object that tend to be rated by a user. The models we present not
only extract ratable aspects, but also cluster them into coherent topics, e.g.,
`waitress' and `bartender' are part of the same topic `staff' for restaurants.
This differentiates it from much of the previous work which extracts aspects
through term frequency analysis with minimal clustering. We evaluate the
multi-grain models both qualitatively and quantitatively to show that they
improve significantly upon standard topic models.


title:
Future instrumentation for the study of the Warm-Hot Intergalactic
  Medium

abstract:
  We briefly review capabilities and requirements for future instrumentation in
UV- and X-ray astronomy that can contribute to advancing our understanding of
the diffuse, highly ionised intergalactic medium.


title:
An Halpha-selected sample of cataclysmic variables -- I. Observations of
  newly discovered systems

abstract:
  Strong selection effects are present in observational samples of cataclysmic
variables (CVs), complicating comparisons to theoretical predictions. The
selection criteria used to define most CV samples discriminate heavily against
the discovery of short-period, intrinsically faint systems. The situation can
be improved by selecting CVs for the presence of emission lines. For this
reason, we have constructed a homogeneous sample of CVs selected on the basis
of Halpha emission. We present discovery observations of the 14 CVs and 2
additional CV candidates found in this search. The orbital periods of 11 of the
new CVs were measured; all are above 3 h. There are two eclipsing systems in
the sample, and one in which we observed a quasi-periodic modulation on a \sim
1000 s time-scale. We also detect the secondary star in the spectrum of one
system, and measure its spectral type. Several of the new CVs have the
spectroscopic appearance of nova-like variables (NLs), and a few display what
may be SW Sex star behaviour. In a companion paper, we discuss the implications
of this new sample for CV evolution.


title: On Wittgenstein's philosophy of mathematics

abstract:
  Mathematics cannot anymore be assimilated to a linguistic game, where formal
proofs are strongly differentiated with conjectural thinking, without building
any category of knowledge to understand the passage (Wittgenstein's gist).
Nowadays, philosophy has to face with the growing, exponential ramified tree of
speculative mathematical thinking. Our main (problematical) theses are: 1. In
mathematics, there is no empirical automatism, and no separate, physical-like
motricity. 2: The irreversible-synthetical must force to complexify the
exegetical game of philosophy; numerical experiments in algebra and in number
theory are a kind of letting blow up all possible problems; 4. The nature of
mathematical questioning still remains in question.


title:
The lowest-possible BER and FER for any discrete memoryless channel with
  given capacity

abstract:
  We investigate properties of a channel coding scheme leading to the
minimum-possible frame error ratio when transmitting over a memoryless channel
with rate R>C. The results are compared to the well-known properties of a
channel coding scheme leading to minimum bit error ratio. It is concluded that
these two optimization requests are contradicting. A valuable application of
the derived results is presented.


abstract:
  We present CCD photometric and mass function study of 9 young Large
Magellanic Cloud star clusters namely NGC 1767, NGC 1994, NGC 2002, NGC 2003,
NGC 2006, SL 538, NGC 2011, NGC 2098 and NGC 2136. The BVRI data reaching down
to V ~ 21 mag, are collected from 3.5-meter NTT/EFOSC2 in sub-arcsec seeing
conditions. For NGC 1767, NGC 1994, NGC 2002, NGC 2003, NGC 2011 and NGC 2136,
broad band photometric CCD data are presented for the first time. Seven of the
9 clusters have ages between 16 to 25 Myr while remaining two clusters have
ages $32\pm4$ Myr (NGC 2098) and $90\pm10$ Myr (NGC 2136). For 7 younger
clusters, the age estimates based on a recent model and the integrated spectra
are found to be systematically lower ($\sim$ 10 Myr) from the present estimate.
In the mass range of $\sim 2 - 12$ $M_{\odot}$, the MF slopes for 8 out of nine
clusters were found to be similar with the value of $\gamma$ ranging from
$-1.90\pm0.16$ to $-2.28\pm0.21$. For NGC 1767 it is flatter with $\gamma =
-1.23\pm0.27$. Mass segregation effects are observed for NGC 2002, NGC 2006,
NGC 2136 and NGC 2098. This is consistent with the findings of Kontizas et al.
for NGC 2098. Presence of mass segregation in these clusters could be an
imprint of star formation process as their ages are significantly smaller than
their dynamical evolution time. Mean MF slope of $\gamma = -2.22\pm0.16$
derived for a sample of 25 young ($\le 100$ Myr) dynamically unevolved LMC
stellar systems provide support for the universality of IMF in the intermediate
mass range $\sim 2-12 M_{\odot}$.


title: Vertically Extended Neutral Gas in the Massive Edge-on Spiral NGC 5746

abstract:
  We present Very Large Array 21-cm observations of the massive edge-on spiral
galaxy NGC 5746. This galaxy has recently been reported to have a luminous
X-ray halo, which has been taken as evidence of residual hot gas as predicted
in galaxy formation scenarios. Such models also predict that some of this gas
should undergo thermal instabilities, leading to a population of warm clouds
falling onto the disk. If so, then one might expect to find a vertically
extended neutral layer. We detect a substantial high-latitude component, but
conclude that almost all of its mass of 1.2-1.6 billion solar masses most
likely resides in a warp. Four features far from the plane containing about 100
million solar masses are found at velocities distinct from this warp. These
clouds may be associated with the expected infall, although an origin in a
disk-halo flow cannot be ruled out, except for one feature which is
counter-rotating. The warp itself may be a result of infall according to recent
models. But clearly this galaxy lacks a massive, lagging neutral halo as found
in NGC 891. The disk HI is concentrated into two rings of radii 1.5 and 3
arcminutes. Radial inflow is found in the disk, probably due to the bar in this
galaxy. A nearby member of this galaxy group, NGC 5740, is also detected. It
shows a prominent one-sided extension which may be the result of ram pressure
stripping.


title:
An Halpha-selected sample of cataclysmic variables -- II. Implications
  for CV evolution

abstract:
  We use an independent new sample of cataclysmic variables (CVs), constructed
by selecting objects for Halpha emission, to constrain the properties of the
intrinsic CV population. This sample is restricted to systems that are likely
to be non-magnetic and unevolved; it consists of 17 CVs, of which at least 10
have orbital periods above 3 h. We find that even very generous allowance for
selection effects is not sufficient to reconcile the large ratio of short- to
long-period CVs predicted by standard CV evolution theory with the observed
sample, possibly implying that short-period systems evolve faster than
predicted by the disrupted magnetic braking model. This would require that an
angular momentum loss mechanism, besides gravitational radiation, acts on CVs
with orbital periods below the period gap. To bring the model into agreement
with observations, the rate of angular momentum loss below the period gap must
be increased by a factor of at least 3, unless the model also over estimates
the angular momentum loss rate of long-period CVs.


title: X-Ray Binaries and the Dynamical States of Globular Clusters

abstract:
  We summarize and discuss recent work (Fregeau 2007) that presents the
confluence of three results suggesting that most Galactic globular clusters are
still in the process of core contraction, and have not yet reached the thermal
equilibrium phase driven by binary scattering interactions: that 1) the three
clusters that appear to be overabundant in X-ray binaries per unit encounter
frequency are observationally classified as "core-collapsed," 2) recent
numerical simulations of cluster evolution with primordial binaries show that
structural parameters of clusters in the binary-burning phase agree only with
"core-collapsed" clusters, and 3) a cluster in the binary-burning phase for the
last few Gyr should have about 5 times more dynamically formed X-ray sources
than if it were in the core contraction phase for the same time.


title:
Merging of globular clusters within inner galactic regions. II. The
  Nuclear Star Cluster formation

abstract:
  In this paper we present the results of two detailed N-body simulations of
the interaction of a sample of four massive globular clusters in the inner
region of a triaxial galaxy. A full merging of the clusters takes place,
leading to a slowly evolving cluster which is quite similar to observed Nuclear
Clusters. Actually, both the density and the velocity dispersion profiles match
qualitatively, and quantitatively after scaling, with observed features of many
nucleated galaxies. In the case of dense initial clusters, the merger remnant
shows a density profile more concentrated than that of the progenitors, with a
central density higher than the sum of the central progenitors central
densities. These findings support the idea that a massive Nuclear Cluster may
have formed in early phases of the mother galaxy evolution and lead to the
formation of a nucleus, which, in many galaxies, has indeed a luminosity
profile similar to that of an extended King model. A correlation with galactic
nuclear activity is suggested.


title: Emerging singularities in the bouncing loop cosmology

abstract:
  In this paper we calculate $\mathcal{O}(\mu^4)$ corrections from holonomies
in the Loop Quantum Gravity, usually not taken into account. Allowance of the
corrections of this kind is equivalent with the choice of the new quatization
scheme. Quantization ambiguities in the Loop Quantum Cosmology allow for this
additional freedom and presented corrections are consistent with the standard
approach. We apply these corrections to the flat FRW cosmological model and
calculate the modified Friedmann equation. We show that the bounce appears in
the models with the standard $\mathcal{O}(\mu^2)$ quantization scheme is
shifted to the higher energies $\rho_{\text{bounce}} = 3 \rho_{\text{c}}$. Also
a pole in the Hubble parameter appears for $\rho_{\text{pole}} = {3/2}
\rho_{\text{c}}$ corresponding to \emph{hyper-inflation/deflation} phases. This
pole represents a curvature singularity at which the scale factor is finite. In
this scenario the singularity and bounce co-exist. Moreover we find that an
ordinary bouncing solution appears only when quantum corrections in the lowest
order are considered. Higher order corrections can lead to the nonperturbative
effects.


title: Decay Spectrum of $K^+ \to e^+ \nu_{e}\gamma$

abstract:
  The form factors of the $K^+ \to \gamma$ transition are studied in the
light-front quark model and chiral perturbation theory of $O(p^6)$. The decay
spectrum of $K^+ \to e^+ \nu_{e}\gamma$, dominated by the structure dependent
contribution, is illustrated in both models.


title: Tunneling through molecules and quantum dots: master-equation approaches

abstract:
  An important class of approaches to the description of electronic transport
through molecules and quantum dots is based on the master equation. We discuss
various formalisms for deriving a master equation and their interrelations. It
is shown that the master equations derived by Wangsness, Bloch, and Redfield
and by Koenig et al. are equivalent. The roles of the large-reservoir and
Markov approximations are clarified. The Markov approximation is traced back to
nonzero bias voltage and temperature, whereas interactions and the
corresponding rapid relaxation in the leads are shown to be irrelevant for the
transport under certain conditions. It is explained why the T-matrix formalism
gives incomplete results except for diagonal density operators and to second
order in the tunneling amplitudes. The time-convolutionless master equation is
adapted to tunneling problems and a diagrammatic scheme for generating
arbitrary orders in the tunneling amplitudes is developed.


title:
Time variability of accretion flows: effects of the adiabatic index and
  gas temperature

abstract:
  We report on next phase of our study of rotating accretion flows onto black
holes. We consider hydrodynamical (HD) accretion flows with a spherically
symmetric density distribution at the outer boundary but with spherical
symmetry broken by the introduction of a small, latitude-dependent angular
momentum. We study accretion flows by means of numerical two-dimensional,
axisymmetric, HD simulations for variety of the adiabatic index, $\gamma$ and
the gas temperature at infinity, $c_\infty$. Our work is an extension of work
done by Proga & Begelman who consider models for only $\gamma=5/3$. Our main
result is that the flow properties such as the topology of the sonic surface
and time behavior strongly depend on $\gamma$ but little on $c_\infty$. In
particular, for $1 < \gamma < 5/3$, the mass accretion rate shows large
amplitude, slow time-variability which is a result of mixing between slow and
fast rotating gas. This temporal behavior differs significantly from that in
models with $\gamma\simless 5/3$ where the accretion rate is relatively
constant and from that in models with $\gamma\simgreat 1$ where the accretion
exhibits small amplitude quasi-periodic oscillations. The key parameter
responsible for the differences is the sound speed of the accretion flow which
in turn determines whether the flow is dominated by gas pressure, radiation
pressure or rotation. Despite these differences the time-averaged mass
accretion rate in units of the corresponding Bondi rate is a weak function of
$\gamma$ and $c_\infty$.


title:
Surface energies, work functions, and surface relaxations of low index
  metallic surfaces from first-principles

abstract:
  We study the relaxations, surface energies, and work functions of low index
metallic surfaces using pseudopotential plane-wave density-functional
calculations within the generalized gradient approximation. We study here the
(100), (110), and (111) surfaces of Al, Pd, Pt, and Au and the (0001) surface
of Ti, chosen for their use as contact or lead materials in nanoscale devices.
We consider clean, mostly non-reconstructed surfaces in the slab-supercell
approximation. Particular attention is paid to the convergence of these
quantities with respect to slab thickness; furthermore, different methodologies
for the calculation of work functions and surfaces energies are compared. We
find that the use of bulk references for calculations of surface energies and
work functions can be detrimental to convergence unless numerical grids are
closely matched, especially when surface relaxations are being considered. Our
results and comparison show that calculated values often do not quantitatively
match experimental values. This may be understandable for the surface
relaxations and surface energies, where experimental values can have large
error, but even for the work functions, neither local nor semi-local
functionals emerge as an accurate choice for every case.


title:
Single Transverse Spin Asymmetries of Identified Charged Hadrons in
  Polarized p+p Collisions at $\sqrt{s}$ = 62.4 GeV

abstract:
  The first measurements of $x_F$-dependent single spin asymmetries of
identified charged hadrons, $\pi^{\pm}$, $K^{\pm}$, and protons, from
transversely polarized proton-proton collisions at 62.4 GeV at RHIC are
presented. The measurements extend to high-$x_F$ ($|x_F|\sim 0.6$) in both the
forward and backward directions.Large asymmetries are seen in the pion and kaon
channels. The asymmetries in inclusive $\pi^{+}$ production, $A_N(\pi^+)$,
increase with $x_F$ from 0 to $\sim$0.25 %at $x_F = 0.6$ and $A_N(\pi^{-})$
decrease from 0 to $\sim$$-$0.4. Even though $K^-$ contains no valence quarks,
observed asymmetries for $K^-$ unexpectedly show positive values similar to
those for $K^+$, increasing with $x_F$, whereas proton asymmetries are
consistent with zero over the measured kinematic range. Comparisons of the data
with predictions of QCD-based models are presented. The flavor dependent single
spin asymmetry measurements of identified hadrons allow for stringent tests of
theoretical models of partonic dynamics in the RHIC energy regime.


title:
On the robustness of power-law random graphs in the finite mean,
  infinite variance region

abstract:
  We consider a conditionally Poissonian random graph model where the mean
degrees, `capacities', follow a power-tailed distribution with finite mean and
infinite variance. Such a graph of size $N$ has a giant component which is
super-small in the sense that the typical distance between vertices is of the
order of $\log\log N$. The shortest paths travel through a core consisting of
nodes with high mean degrees. In this paper we derive upper bounds of the
typical distance when an upper part of the core is removed, including the case
that the whole core is removed.


title:
Expansion velocities and core masses of bright planetary nebulae in the
  Virgo cluster

abstract:
  The line-of-sight velocities and [OIII] 5007 AA expansion velocities are
measured for 11 planetary nebulae (PNs) in the Virgo cluster core, at 15 Mpc
distance, with the FLAMES spectrograph on the ESO VLT. These PNs are located
about halfway between the two giant ellipticals M87 and M86. From the [OIII]
5007 AA line profile widths, the average half-width at half maximum expansion
velocity for this sample of 11 PNs is v_HWHM = 16.5 km/s (RMS=2.6 km/s). We use
the PN subsample bound to M87 to remove the distance uncertainties, and the
resulting [OIII] 5007 AA luminosities to derive the central star masses. We
find these masses to be at least 0.6 M_sun and obtain PN observable life times
t_PN < 2000 yrs, which imply that the bright PNs detected in the Virgo cluster
core are compact, high density nebulae. We finally discuss several scenarios
for explaining the high central star masses in these bright M87 halo PNs.


title:
A robust statistical estimation of the basic parameters of single
  stellar populations. I. Method

abstract:
  The colour-magnitude diagrams of resolved single stellar populations, such as
open and globular clusters, have provided the best natural laboratories to test
stellar evolution theory. Whilst a variety of techniques have been used to
infer the basic properties of these simple populations, systematic
uncertainties arise from the purely geometrical degeneracy produced by the
similar shape of isochrones of different ages and metallicities. Here we
present an objective and robust statistical technique which lifts this
degeneracy to a great extent through the use of a key observable: the number of
stars along the isochrone. Through extensive Monte Carlo simulations we show
that, for instance, we can infer the four main parameters (age, metallicity,
distance and reddening) in an objective way, along with robust confidence
intervals and their full covariance matrix. We show that systematic
uncertainties due to field contamination, unresolved binaries, initial or
present-day stellar mass function are either negligible or well under control.
This technique provides, for the first time, a proper way to infer with
unprecedented accuracy the fundamental properties of simple stellar
populations, in an easy-to-implement algorithm.


title:
BF Eridani: a cataclysmic variable with a massive white dwarf and an
  evolved secondary

abstract:
  We present high- and medium-resolution spectroscopic observations of the
cataclysmic variable BF Eri during its low and bright states. The orbital
period of this system was found to be 0.270881(3) days. The secondary star is
clearly visible in the spectra through absorption lines of the neutral metals
MgI, FeI and CaI. Its spectral type was found to be K3+-0.5. A radial velocity
study of the secondary yielded a semi-amplitude of K_2=182.5+-0.9 km/s. The
radial velocity semiamplitude of the white dwarf was found to be K_1=74+-3 km/s
from the motion of the wings of the Halpha and Hbeta emission lines. From these
parameters we have obtained that the secondary in BF Eri is an evolved star
with a mass of 0.50-0.59 Msun, whose size is about 30 per cent larger than a
zero-age main-sequence single-star of the same mass. We also show that BF Eri
contains a massive white dwarf (M1>1.23 Msun), allowing us to consider the
system as a SN Ia progenitor. BF Eri also shows a high gamma-velocity
(gamma=-94 km/s) and substantial proper motion. With our estimation of the
distance to the system (d~700+-200 pc), this corresponds to a space velocity of
~350 km/s with respect to the dynamical local standard of rest. The cumulative
effect of repeated nova eruptions with asymmetric envelope ejection might
explain the high space velocity of the system. We analyze the outburst
behaviour of BF Eri and question the current classification of the system as a
dwarf nova. We propose that BF Eri might be an old nova exhibiting "stunted"
outbursts.


title: Stability in the Stefan problem with surface tension (I)

abstract:
  We develop a high-order energy method to prove asymptotic stability of flat
steady surfaces for the Stefan problem with surface tension - also known as the
Stefan problem with Gibbs-Thomson correction.


title: Nonlinear Photonic Quasicrystals for Novel Optical Devices

abstract:
  Two well-known methods for the design of quasicrystal models are used to
create novel nonlinear optical devices. These devices are useful for efficient
three-wave mixing of several different processes, and therefore offer greater
flexibility with respect to the more common periodic nonlinear photonic
crystals. We demonstrate applications for polarization switching as well as
multi-wavelength and multi-directional frequency doubling. The generalized dual
grid method is proven to be efficient for designing photonic quasicrystals for
one-dimensional collinear devices as well as elaborate two-dimensional
multi-directional devices. The cut and project method is physically realized by
sending finite-width optical beams at an irrational angle through a periodic
two-dimensional nonlinear photonic crystal. This enables two simultaneous
collinear optical processes that can be varied by changing the angle of the
beams.


title: Perturbations in generalized multi-field inflation

abstract:
  We study the linear perturbations of multi-field inflationary models governed
by a Lagrangian which is a general function of the scalar fields and of a
global kinetic term combining their spacetime gradients with an arbitrary field
space metric. Our analysis includes k-inflation, DBI inflation and its
multi-field extensions which have been recently studied. For this general class
of models, we calculate the action to second order in the linear perturbations.
We decompose the perturbations into an (instantaneous) adiabatic mode, parallel
to the background trajectory, and entropy modes. We show that all the entropy
modes propagate with the speed of light whereas the adiabatic mode propagates
with an effective speed of sound. We also identify the specific combination of
entropy modes which sources the curvature perturbation on large scales. We then
study in some detail the case of two scalar fields: we write explicitly the
equations of motion for the adiabatic and entropy modes in a compact form and
discuss their quantum fluctuations and primordial power spectra.


title: Some improvements to the spherical collapse model

abstract:
  I study the joint effect of dynamical friction, tidal torques and
cosmological constant on clusters of galaxies formation I show that within
high-density environments, such as rich clusters of galaxies, both dynamical
friction and tidal torques slows down the collapse of low-? peaks producing an
observable variation in the time of collapse of the perturbation and, as a
consequence, a reduction in the mass bound to the collapsed perturbation
Moreover, the delay of the collapse produces a tendency for less dense regions
to accrete less mass, with respect to a classical spherical model, inducing a
biasing of over-dense regions toward higher mass I show how the threshold of
collapse is modified if dynamical friction, tidal torques and a non-zero
cosmological constant are taken into account and I use the Extended Press
Schecter (EPS) approach to calculate the effects on the mass function Then, I
compare the numerical mass function given in Reed et al (2003) with the
theoretical mass function obtained in the present paper I show that the barrier
obtained in the present paper gives rise to a better description of the mass
function evolution with respect to other previous models (Sheth & Tormen 1999,
MNRAS, 308, 119 (hereafter ST); Sheth & Tormen 2002, MNRAS, 329, 61 (hereafter
ST1))


title: Modeling the Coastal Ocean over a Time Period of Several Weeks

abstract:
  From a scale analysis of hydrodynamic phenomena having a significant action
on the drift of an object in coastal ocean waters, we deduce equations modeling
the associated hydrodynamic fields over a time period of several weeks. These
models are essentially non linear hyperbolic systems of PDE involving a small
parameter. Then from the models we extract a simplified and nevertheless
typical one for which we prove that its classical solution exists on a time
interval which is independent of the small parameter. We then show that the
solution weak-* converges as the small parameter goes to zero and we
characterize the equation satisfied by the weak-* limit


title:
Optimal Transport, Convection, Magnetic Relaxation and Generalized
  Boussinesq equations

abstract:
  We establish a connection between Optimal Transport Theory and classical
Convection Theory for geophysical flows. Our starting point is the model
designed few years ago by Angenent, Haker and Tannenbaum to solve some Optimal
Transport problems. This model can be seen as a generalization of the
Darcy-Boussinesq equations, which is a degenerate version of the
Navier-Stokes-Boussinesq (NSB) equations. In a unified framework, we relate
different variants of the NSB equations (in particular what we call the
generalized Hydrostatic-Boussinesq equations) to various models involving
Optimal Transport (and the related Monge-Ampere equation. This includes the 2D
semi-geostrophic equations and some fully non-linear versions of the so-called
high-field limit of the Vlasov-Poisson system and of the Keller-Segel for
Chemotaxis. Finally, we show how a ``stringy'' generalization of the AHT model
can be related to the magnetic relaxation model studied by Arnold and Moffatt
to obtain stationary solutions of the Euler equations with prescribed topology.


title: Are retrograde resonances possible in multi-planet systems?

abstract:
  Most multi-planetary systems are characterized by hot-Jupiters close to their
central star, moving on eccentric orbits. From a dynamical point of view,
compact multi-planetary systems form a specific class of the general N-body
problem (where N>=3). Moreover, extrasolar planets are found in prograde orbits
about their host star, and often in mean motion resonances (MMR). In a first
step, we study theoretically a new stabilizing mechanism suitable for compact
two-planet systems. This mechanism involves counter-revolving orbits forming a
retrograde MMR. In a second step, we investigate the feasibility of planetary
systems hosting counter-revolving planets. Dynamical stability, observations,
and formation processes of these systems are analyzed and discussed. To
characterize the dynamical behavior of multi-dimensional planetary systems, we
apply our technique of global dynamics analysis based on the MEGNO indicator
(Mean Exponential Growth factor of Nearby Orbits) that provides the fine
structure of the phase space. In a few cases of possible counter-revolving
configurations, we carry out new fits to the observations using the Pikaia
genetic algorithm. A statistical study of the stability in the neighborhood of
different observed, planetary-systems is completed using a Monte-Carlo method.
We analyse the observational data for the HD73526 planetary system and find
that counter-revolving configurations may be consistent with the observational
data. We highlight the fine and characteristic structure of retrograde MMRs. We
demonstrate that retrograde resonances open a family of stabilizing mechanisms
involving new apsidal precession behaviors. Considering two possible formation
mechanisms (free-floating planet and Slingshot model), we conclude that
counter-revolving configurations are feasible.


title: Tunneling dynamics of few bosons in a double well

abstract:
  We study few-boson tunneling in a one-dimensional double well. As we pass
from weak interactions to the fermionization limit, the Rabi oscillations first
give way to highly delayed pair tunneling (for medium coupling), whereas for
very strong correlations multi-band Rabi oscillations emerge. All this is
explained on the basis of the exact few-body spectrum and without recourse to
the conventional two-mode approximation. Two-body correlations are found
essential to the understanding of the different tunnel mechanisms. The
investigation is complemented by discussing the effect of skewing the double
well, which offers the possibility to access specific tunnel resonances


title: Dark matter and structure formation a review

abstract:
  This paper provides a review of the variants of dark matter which are thought
to be fundamental components of the universe and their role in origin and
evolution of structures and some new original results concerning improvements
to the spherical collapse model. In particular, I show how the spherical
collapse model is modified when we take into account dynamical friction and
tidal torques.


title:
Measurement of the Total Charm Cross Section by Electron-Positron
  Annihilation at Energies Between 3.97-4.26 GeV

abstract:
  Using the CLEO-c detector, we have measured the charm hadronic cross sections
for $e^{+}e^{-}$ annihilations at a total of thirteen center-of-mass energies
between 3.97 and 4.26 GeV. Observed cross sections for the production of
$D\bar{D}$, $D^{*}\bar{D}$, $D^{*}\bar{D}^{*}$, $D_{s}\bar{D}_{s}$,
$D_{s}^{*}\bar{D}_{s}$, and $D_{s}^{*}\bar{D}_{s}^{*}$, in addition to the
total charm cross section are presented. Observed cross sections were
radiatively corrected to obtain tree-level cross sections and R.


title: Heat equation approach to index theorems on odd dimensional manifolds

abstract:
  D.Freed has formulated and proved an index theorem on odd dimensional spin
manifolds with boundary. The proof is based on analysis by Calderon and Seeley.
In this note we are going to give a proof of this theorem using the heat
kernels methods for boundary conditions of Dirichlet and Von Neumann type.
Moreover we consider also the Atiyah-Patodi-Singer spectral boundary condition
which is not considered in Freed's paper. As a direct consequence of the
method, we will obtain some information about isospectral invariants of the
boundary conditions. This proof does not uses the cobordism invariance of index
and are easily generalized to family case.


title:
Collective properties of magnetobiexcitons in quantum wells' and
  graphene superlattices

abstract:
  We propose the Bose-Einstein condensation (BEC) and superfluidity of
quasi-two-dimensional (2D) spatially indirect magnetobiexcitons in a slab of
superlattice with alternating electron and hole layers consisting from the
semiconducting quantum wells (QWs) and graphene superlattice in high magnetic
field. The two different Hamiltonians of a dilute gas of magnetoexcitons with a
dipole-dipole repulsion in superlattices consisting of both QWs and graphene
layers in the limit of high magnetic field have been reduced to one effective
Hamiltonian a dilute gas of two-dimensional excitons without magnetic field.
Moreover, for $N$ excitons we have reduced the problem of $2N\times 2$
dimensional space onto the problem of $N\times 2$ dimensional space by
integrating over the coordinates of the relative motion of an electron (e) and
a hole (h). The instability of the ground state of the system of interacting
two-dimensional indirect magnetoexcitons in a slab of superlattice with
alternating electron and hole layers in high magnetic field is established. The
stable system of indirect quasi-two-dimensional magnetobiexcitons, consisting
of pair of indirect excitons with opposite dipole moments is considered. The
density of superfluid component $n_{s}(T)$ and the temperature of the
Kosterlitz-Thouless phase transition to the superfluid state in the system of
two-dimensional indirect magnetobiexcitons, interacting as electrical
quadrupoles, are obtained for both QW and graphene realizations.


title: Simultaneous analysis of Lasso and Dantzig selector

abstract:
  We exhibit an approximate equivalence between the Lasso estimator and Dantzig
selector. For both methods we derive parallel oracle inequalities for the
prediction risk in the general nonparametric regression model, as well as
bounds on the $\ell_p$ estimation loss for $1\le p\le 2$ in the linear model
when the number of variables can be much larger than the sample size.


title: On the nature of gravitational forces

abstract:
  In this paper I show how the statistics of the gravitational field is changed
when the system is characterized by a non-uniform distribution of particles. I
show how the distribution functions W(dF/dt) giving the joint probability that
a test particle is subject to a force F and an associated rate of change of F
given by dF/dt, are modified by inhomogeneity. Then I calculate the first
moment of dF/dt to study the effects of inhomogenity on dynamical friction.
Finally I test, by N-Body simulations, that the theoretical W(F) and dF/dt
describes correctly the experimental data and I find that the stochastic force
distribution obtained for the evolved system is in good agreement with theory.
Moreover, I find that in an inhomogeneous background the friction force is
actually enhanced relative to the homogeneous case.


title:
A Combinatorial Interpretation for Certain Relatives of the Conolly
  Sequence

abstract:
  For any integer s >= 0, we derive a combinatorial interpretation for the
family of sequences generated by the recursion (parameterized by s) h_s(n) =
h_s(n - s - h_s(n - 1)) + h_s(n - 2 - s - h_s(n - 3)), n > s + 3, with the
initial conditions h_s(1) = h_s(2) = ... = h_s(s+2) = 1 and h_s(s+3) = 2. We
show how these sequences count the number of leaves of a certain infinite tree
structure. Using this interpretation we prove that h_s sequences are "slowly
growing", that is, h_s sequences are monotone nondecreasing, with successive
terms increasing by 0 or 1, so each sequence hits every positive integer.
Further, for fixed s the sequence h_s(n) hits every positive integer twice
except for powers of 2, all of which are hit s+2 times. Our combinatorial
interpretation provides a simple approach for deriving the ordinary generating
functions for these sequences.


title: Block Diagonalization using SRG Flow Equations

abstract:
  By choosing appropriate generators for the Similarity Renormalization Group
(SRG) flow equations, different patterns of decoupling in a Hamiltonian can be
achieved. Sharp and smooth block-diagonal forms of phase-shift equivalent
nucleon-nucleon potentials in momentum space are generated as examples and
compared to analogous low-momentum interactions ("v_lowk").


title:
Volatile Element Chemistry during Metamorphism of Ordinary Chondritic
  Material and Some of its Implications for the Composition of Asteroids

abstract:
  We used chemical equilibrium calculations to model thermal metamorphism of
ordinary chondritic material as a function of temperature, pressure, and trace
element abundance and use our results to discuss volatile mobilization during
thermal metamorphism of ordinary chondrite parent bodies. The calculations
include ~1,700 solids and gases of 40 elements. We compiled trace element
abundances in H-, L-, and LL-chondrites for the elements Ag, As, Au, Bi, Cd,
Cs, Cu, Ga, Ge, In, Pb, Rb, Sb, Se, Sn, Te, Tl, and Zn, and identified
abundance trends as a function of petrographic type within each class. We found
that abundance patterns within the H- and L- chondrites are consistent with
mobilization of volatile elements in an onionshell-type parent body.
LL-chondrites have more complex abundance patterns that may support a
rubble-pile model for the LL-chondrite parent body. We calculated volatility
sequences for the trace elements in the ordinary chondritic material, which
differs significantly from the solar nebula volatility sequence.


title: Asphericity in Supernova Explosions from Late-Time Spectroscopy

abstract:
  Core-collapse supernovae (CC-SNe) are the explosions that announce the death
of massive stars. Some CC-SNe are linked to long-duration gamma-ray bursts
(GRBs) and are highly aspherical. One important question is to what extent
asphericity is common to all CC-SNe. Here we present late-time spectra for a
number of CC-SNe from stripped-envelope stars, and use them to explore any
asphericity generated in the inner part of the exploding star, near the site of
collapse. A range of oxygen emission-line profiles is observed, including a
high incidence of double-peaked profiles, a distinct signature of an aspherical
explosion. Our results suggest that all CC-SNe from stripped-envelope stars are
aspherical explosions and that SNe accompanied by GRBs exhibit the highest
degree of asphericity.


title: Novae as a Class of Transient X-ray Sources

abstract:
  Motivated by the recently discovered class of faint (10^34-10^35 ergs/s)
X-ray transients in the Galactic Center region, we investigate the 2-10 keV
properties of classical and recurrent novae. Existing data are consistent with
the idea that all classical novae are transient X-ray sources with durations of
months to years and peak luminosities in the 10^34-10^35 ergs/s range. This
makes classical novae a viable candidate class for the faint Galactic Center
transients. We estimate the rate of classical novae within a 15 arcmin radius
region centered on the Galactic Center (roughly the field of view of XMM-Newton
observations centered on Sgr A*) to be ~0.1 per year. Therefore, it is
plausible that some of the Galactic Center transients that have been announced
to date are unrecognized classical novae. The continuing monitoring of the
Galactic Center region carried out by Chandra and XMM-Newton may therefore
provide a new method to detect classical novae in this crowded and obscured
region, where optical surveys are not, and can never hope to be, effective.
Therefore, X-ray monitoring may provide the best means of testing the
completeness of the current understanding of the nova populations.


title: Multiferroicity due to nonstoichiometry in the chain cuprate LiVCuO_4

abstract:
  The recently observed multiferroic behavior in the s=1/2 chain cuprate
LiVCuO_4 (LiCuVO_4) with edge-shared CuO_4 plaquettes and helical spin ordering
does not agree with the existing theories such as a spin-current scenario. We
argue that the effect can be consistently explained, if the exchange-induced
electric polarization on the out-of-chain Cu^2+ centers substituting for
Li-ions in LiVCuO_4 is taken into account. These substituent centers are proved
to be an effective probe of the spin incommensurability and the magnetic field
effects.


title: Berry Phase Effect on Exciton Transport and Bose Einstein Condensate

abstract:
  With exciton lifetime much extended in semiconductor quantum-well structures,
their transport and Bose-Einstein condensation become a focus of research in
recent years. We reveal a momentum-space gauge field in the exciton
center-of-mass dynamics due to Berry phase effects. We predict spin-dependent
topological transport of the excitons analogous to the anomalous Hall and
Nernst effects for electrons. We also predict spin-dependent circulation of a
trapped exciton gas and instability in an exciton condensate in favor of vortex
formation.


title: Continuous-Variable Telecloning with Phase-Conjugate Inputs

abstract:
  We propose a scheme for continuous-variable telecloning with phase-conjugate
inputs (PCI). Two cases of PCI telecloning are considered. The first case is
where PCI telecloning produces $M$ clones nonlocally and $M$ anticlones
locally, or vice versa. This kind of PCI telecloning requires only one EPR
(Einstein-Podolsky-Rosen) entangled, two-mode squeezed state as a resource for
building the appropriate multi-mode, multipartite entangled state via linear
optics. The other case is a PCI telecloning protocol in which both clones and
anticlones are created nonlocally. Such a scheme requires two EPR entangled
states for the generation of a suitable multipartite entangled state. As our
schemes are reversible, optimal cloning fidelities are achieved in the limit of
infinite squeezing.


title: On the importance of high redshift intergalactic voids

abstract:
  We investigate the properties of one--dimensional flux ``voids'' (connected
regions in the flux distribution above the mean flux level) by comparing
hydrodynamical simulations of large cosmological volumes with a set of observed
high--resolution spectra at z ~ 2. After addressing the effects of box size and
resolution, we study how the void distribution changes when the most
significant cosmological and astrophysical parameters are varied. We find that
the void distribution in the flux is in excellent agreement with predictions of
the standard LCDM cosmology, which also fits other flux statistics remarkably
well. We then model the relation between flux voids and the corresponding
one--dimensional gas density field along the line--of--sight and make a
preliminary attempt to connect the one--dimensional properties of the gas
density field to the three--dimensional dark matter distribution at the same
redshift. This provides a framework that allows statistical interpretations of
the void population at high redshift using observed quasar spectra, and
eventually it will enable linking the void properties of the high--redshift
universe with those at lower redshifts, which are better known.


title:
A Catalog of Local E+A(post-starburst) Galaxies selected from the Sloan
  Digital Sky Survey Data Release 5

abstract:
  E+A galaxies have been interpreted as post-starburst galaxies based on the
presence of strong Balmer absorption lines combined with the absence of major
emission lines ([OII] nor H$\alpha$). As a population of galaxies in the midst
of the transformation, E+A galaxies has been subject to an intense research
activity. It has been, however, difficult to investigate E+A galaxies
statistically since E+A galaxies are an extremely rare population of galaxies
($<$1% of all galaxies in the local Universe).
  Here, we present a large catalog of 564 E+A (post-starburst) galaxies
carefully selected from half million spectra of the Sloan Digital Sky Survey
Data Release 5. We define E+A galaxies as those with H$\delta$ equivalent width
$>$5\AA and no detectable emission in [OII] $and$ H$\alpha$. The catalog
contains 564 E+A galaxies, and thus, is one of the largest of the kind to date.
In addition, we have included the H$\alpha$ line in the selection to remove
dusty star-forming galaxies, which could have contaminated previous [OII]-based
samples of E+A galaxies up to 52%. Thus, the catalog is one of the most
homogeneous, let alone its size. The catalog presented here can be used for
follow-up observations and statistical analyses of this rare population of
galaxies.


title:
The Internal Shear of Type Ia Supernova Progenitors During Accretion and
  Simmering

abstract:
  A white dwarf (WD) gains substantial angular momentum during the accretion
process that grows it toward a Chandrasekhar mass. It is therefore expected to
be quickly rotating when it ignites as a Type Ia supernova. The thermal and
shearing profile are important for subsequent flame propagation. We highlight
processes that could affect the WD shear, during accretion as well as during
the ~1000 years of pre-explosive simmering. Baroclinic instabilities and/or the
shear growth of small magnetic fields provide sufficient torque to bring the WD
very close to solid body rotation during accretion. The lack of significant
shear makes it difficult to grow a WD substantially past the typical
Chandrasekhar mass. Once carbon ignites, a convective region spreads from the
WD's center. This phase occurs regardless of progenitor scenario, and therefore
it is of great interest for understanding how the WD interior is prepared
before the explosive burning begins. We summarize some of the key properties of
the convective region, which includes demonstrating that the mass enclosed by
convection at any given time depends most sensitively on a single parameter
that can be expressed as either the ratio of temperatures or densities at the
top and bottom of the convection zone. At low Rossby numbers the redistribution
of angular momentum by convection may result in significant shearing at the
convective/non-convective boundary.


title: Spatially Resolved Spectroscopy of Passive Spiral Galaxies

abstract:
  Passive spiral galaxies, despite their spiral morphological appearance, do
not have any emission lines indicative of ongoing star formation in their
optical spectra. Previous studies have suggested that passive spiral galaxies
preferentially exist in infall regions of galaxy clusters, suggesting that the
cluster environment is likely to be responsible for creating these galaxies. By
carrying out spatially resolved long-slit spectroscopy on four nearby passive
spiral galaxies with the Apache Point Observatory 3.5-m telescope, we
investigated the stellar populations of passive spiral galaxies separately for
their inner and outer regions. In the two unambiguously passive spiral galaxies
among the four observed galaxies, H$\delta$ absorption lines are more prominent
in the outer regions of the galaxies, whereas the 4000-{\AA} breaks
(D$_{4000}$) are strongest in the inner regions of the galaxies. A comparison
with a simple stellar population model for the two passive spiral galaxies
indicates that the outer regions of the galaxies tend to harbour younger
populations of stars. The strong H$\delta$ absorption observed in the outer
regions of the sample galaxies is consistent with that of galaxies whose star
formation ceased a few Gyrs ago. Because of the large uncertainty in the
absorption indices in our samples, further observations are needed in order to
place constraints on the mechanisms that quench star formation in passive
spiral galaxies.


title:
Integrated field spectroscopy of E+A (post-starburst) galaxies with the
  Kyoto3DII

abstract:
  We have performed a two-dimensional spectroscopy of three nearby E+A
(post-starburst) galaxies with the Kyoto3DII integral field spectrograph. In
all the cases, Hdelta absorption is stronger at the centre of the galaxies, but
significantly extended in a few kpc scale. For one galaxy (J1656), we found a
close companion galaxy at the same redshift. The galaxy turned out to be a
star-forming galaxy with a strong emission in Hgamma. For the other two
galaxies, we have found that the central post-starburst regions possibly extend
toward the direction of the tidal tails. Our results are consistent with the
merger/interaction origin of E+A galaxies, where the infalling-gas possibly
caused by a galaxy-galaxy merging creates a central-starburst, succeeded by a
post-starburst (E+A) phase once the gas is depleted.


title:
A Near-Infrared Spectroscopic Survey of K-selected Galaxies at z~2.3:
  Redshifts and Implications for Broadband Photometric Studies

abstract:
  Using the Gemini Near-InfraRed Spectrograph (GNIRS), we have completed a
near-infrared spectroscopic survey for K-bright galaxies at z~2.3, selected
from the MUSYC survey. We derived spectroscopic redshifts from emission lines
or from continuum features and shapes for all 36 observed galaxies. The
continuum redshifts are driven by the Balmer/4000 Angstrom break, and have an
uncertainty in dz/(1+z) of <0.019. We use this unique sample to determine, for
the first time, how accurately redshifts and other properties of massive
high-redshift galaxies can be determined from broadband photometric data alone.
We find that the photometric redshifts of the galaxies in our sample have a
systematic error of 0.08 and a random error of 0.13 in dz/(1+z). The systematic
error can be reduced by using optimal templates and deep photometry; the random
error, however, will be hard to reduce below 5%. The spectra lead to
significantly improved constraints for stellar population parameters. For most
quantities this improvement is about equally driven by the higher spectral
resolution and by the much reduced redshift uncertainty. Properties such as the
age, A_V, current star formation rate, and the star formation history are
generally very poorly constrained with broadband data alone. Interestingly
stellar masses and mass-to-light ratios are among the most stable parameters
from broadband data. Nevertheless, photometric studies may overestimate the
number of massive galaxies at 2<z<3, and thus underestimate the evolution of
the stellar mass density. Finally,the spectroscopy supports our previous
finding that red galaxies dominate the high-mass end of the galaxy population
at z=2-3.


title:
An Accurate Age Determination for the SMC Star Cluster NGC121 with
  HST/ACS

abstract:
  As first Paper of a series devoted to study the old stellar population in
clusters and fields in the Small Magellanic Cloud, we present deep observations
of NGC121 in the F555W and F814W filters, obtained with the Advanced Camera for
Surveys on the Hubble Space Telescope. The resulting color-magnitude diagram
reaches ~3.5 mag below the main-sequence turn-off; deeper than any previous
data. We derive the age of NGC121 using both absolute and relative age-dating
methods. Fitting isochrones in the ACS photometric system to the observed ridge
line of NGC121, gives ages of 11.8 +- 0.5 Gyr (Teramo), 11.2 +- 0.5 Gyr
(Padova) and 10.5 +- 0.5 Gyr (Dartmouth). The cluster ridge line is best
approximated by the alpha-enhanced Dartmouth isochrones. Placing our relative
ages on an absolute age scale, we find ages of 10.9 +- 0.5 Gyr (from the
magnitude difference between the main-sequence turn-off and the horizontal
branch) and 11.5 +- 0.5 Gyr (from the absolute magnitude of the horizontal
branch), respectively. These five different age determinations are all lower by
2 - 3 Gyr than the ages of the oldest Galactic globular clusters of comparable
metallicity. Therefore we confirm the earlier finding that the oldest globular
cluster in the Small Magellanic Cloud, NGC121, is a few Gyr younger than its
oldest counterparts in the Milky Way and in other nearby dwarf galaxies such as
the Large Magellanic Cloud, Fornax, and Sagittarius. If it were accreted into
the Galactic halo, NGC121 would resemble the ''young halo globulars'', although
it is not as young as the youngest globular clusters associated with the
Sagittarius dwarf. The young age of NGC121 could result from delayed cluster
formation in the Small Magellanic Cloud or result from the random survival of
only one example of an initially small number star clusters.


title:
Some (big) irreducible components of the moduli space of minimal
  surfaces of general type with $p_g=q=1$ and $K^2=4$

abstract:
  In this paper we study the minimal surfaces of general type with $p_g=q=1$
and $K^2=4$ whose Albanese general fibre has genus 2, classifying those such
that the direct image (under the Albanese morphism) of the bicanonical sheaf is
sum of line bundles. We find 8 unirational families, all of dimension strictly
bigger than the expected one. These families are pairwise disjoint irreducible
components of the moduli space of minimal surfaces of general type.


title: On the spectrum of pure Yang-Mills theory

abstract:
  In this note we discuss the wave functional approach to the spectrum of pure
Yang-Mills theory in 2+1 and 3+1 dimensions by highlighting the issues of
dynamical mass generation and the role played by the kinetic term. We
extrapolate our recent analysis of 2+1 Yang-Mills theory to 3+1 dimensions, and
under certain heuristic assumptions use a simple quasi-Gaussian vacuum
wavefunctional for 3+1 Yang-Mills theory for a preliminary study of the
spectrum of glueballs which nicely fits the available lattice simulations.


title: $G$-Parking Functions, Acyclic Orientations and Spanning Trees

abstract:
  Given an undirected graph $G=(V,E)$, and a designated vertex $q\in V$, the
notion of a $G$-parking function (with respect to $q$) was independently
developed and studied by various authors, and has recently gained renewed
attention. This notion generalizes the classical notion of a parking function
associated with the complete graph. In this work, we study properties of {\em
maximum} $G$-parking functions and provide a new bijection between them and the
set of spanning trees of $G$ with no broken circuit. As a case study, we
specialize some of our results to the graph corresponding to the discrete
$n$-cube $Q_n$. We present the article in an expository self-contained form,
since we found the combinatorial aspects of $G$-parking functions somewhat
scattered in the literature, typically treated in conjunction with sandpile
models and closely related chip-firing games.


title: Space density of optically-selected type 2 quasars

abstract:
  Type 2 quasars are luminous active galactic nuclei (AGN) whose central
regions are obscured by large amounts of gas and dust. In this paper, we
present a catalog of type 2 quasars from the Sloan Digital Sky Survey (SDSS),
selected based on their optical emission lines. The catalog contains 887
objects with redshifts z < 0.83; this is six times larger than the previous
version and is by far the largest sample of type 2 quasars in the literature.
We derive the [OIII]5008 luminosity function for 10^8.3 Lsun < L[OIII] < 10^10
Lsun (corresponding to intrinsic luminosities up to M[2400A]-28 mag or
bolometric luminosities up to 4x10^47 erg/sec). This luminosity function
provides strong lower limits to the actual space density of obscured quasars,
due to our selection criteria, the details of the spectroscopic target
selection, as well as other effects. We derive the equivalent luminosity
function for the complete sample of type 1 (unobscured) quasars; then, we
determine the ratio of type 2/type 1 quasar number densities. Our best data
constrain this ratio to be at least 1.5:1 for 10^8.3 Lsun < L[OIII] < 10^9.5
Lsun at z < 0.3, and at least 1.2:1 for L[OIII]=10^10 Lsun at 0.3 < z < 0.83.
Type 2 quasars are at least as abundant as type 1 quasars in the relatively
nearby Universe (z < 0.8) for the highest luminosities.


title:
Deep MIPS Observations of the IC 348 Nebula: Constraints on the
  Evolutionary State of Anemic Circumstellar Disks and the Primordial-to-Debris
  Disk Transition

abstract:
  We describe new, deep MIPS photometry and new high signal-to-noise optical
spectroscopy of the 2.5 Myr-old IC 348 Nebula. To probe the properties of the
IC 348 disk population, we combine these data with previous optical/infrared
photometry and spectroscopy to identify stars with gas accretion, to examine
their mid-IR colors,and to model their spectral energy distributions. IC 348
contains many sources in different evolutionary states, including protostars
and stars surrounded by primordial disks, two kinds of transitional disks, and
debris disks. Most disks surrounding eary/intermediate spectral-type stars (>
1.4 Msun at 2.5 Myr) are debris disks; most disks surrounding solar and
subsolar-mass stars are primordial disks. At the 1--2 sigma level, more massive
stars also have a smaller frequency of gas accretion and smaller mid-IR
luminosities than lower-mass stars. These trends are suggestive of a stellar
mass-dependent evolution of disks, where most disks around
high/intermediate-mass stars shed their primordial disks on rapid, 2.5 Myr
timescales. The frequency of MIPS-detected transitional disks is ~ 15--35% for
stars plausibly more massive than 0.5 Msun. The relative frequency of
transitional disks in IC 348 compared to that for 1 Myr-old Taurus and 5
Myr-old NGC 2362 is consistent with a transition timescale that is a
significant fraction of the total primordial disk lifetime.


title: Velocity Dependence of Baryon Screening in a Hot Strongly Coupled Plasma

abstract:
  The L-dependence of the static potential between Nc quarks arranged in a
circle of radius L (a "baryon") immersed in the hot plasma of a gauge theory
with Nc colors defines a screening length Ls. We use the AdS/CFT correspondence
to compute this screening length for the case of heavy quarks in the plasma of
strongly coupled N=4 super Yang-Mills theory moving with velocity v relative to
the baryon. We find that in the v -> 1 limit, Ls \propto (1-v^2)^{1/4}/T, and
find that corrections to this velocity dependence are small at lower
velocities. This result provides evidence for the robustness of the analogous
behavior of the screening length defined by the static quark-antiquark pair,
which has been computed previously and in QCD is relevant to quarkonium physics
in heavy ion collisions. Our results also show that as long as the hot wind is
not blowing precisely perpendicular to the plane of the baryon configuration
that we analyze, the Nc different quarks are not all affected by the wind
velocity to the same degree, with those quarks lying perpendicular to the wind
direction screened most effectively.


title:
Detection of `parent' molecules from the inner wind of AGB stars as
  tracers of non-equilibrium chemistry

abstract:
  Asymptotic Giant Branch (AGB) stars are typified by strong dust-driven,
molecular outflows. For long, it was believed that the molecular setup of the
circumstellar envelope of AGB stars is primarily determined by the atmospheric
C/O ratio. However, recent observations of molecules such as HCN, SiO, and SO
reveal gas-phase abundances higher than predicted by thermodynamic equilibrium
(TE) models. UV-photon initiated dissociation in the outer envelope or
non-equilibrium formation by the effect of shocks in the inner envelope may be
the origin of the anomolous abundances. We aim at detecting (i.) a group of
`parent' molecules (CO, SiO, HCN, CS), predicted by the non-equilibrium study
of Cherchneff (2006) to form with almost constant abundances independent of the
C/O ratio and the stellar evolutionary stage on the Asymptotic Giant Branch
(AGB), and (ii.) few molecules, such as SiS and SO,which are sensitive to the
O- or C-rich nature of the star. Several low and high excitation rotational
transitions of key molecules are observed at mm and sub-mm wavelengths with
JCMT and APEX in four AGB stars: the oxygen-rich Mira WX Psc, the S star W Aql,
and the two carbon stars V Cyg and II Lup. A critical density analysis is
performed to determine the formation region of the high-excitation molecular
lines. We detect the four `parent' molecules in all four objects, implying
that, indeed, these chemical species form whatever the stage of evolution on
the AGB. High-excitation lines of SiS are also detected in three stars with
APEX, whereas SO is only detected in the oxygen-rich star WX Psc. This is the
first multi-molecular observational proof that periodically shocked layers
above the photosphere of AGB stars show some chemical homogeneity, whatever the
photospheric C/O ratio and stage of evolution of the star.


title: On the geometry of quantum constrained systems

abstract:
  The use of geometric methods has proved useful in the hamiltonian description
of classical constrained systems. In this note we provide the first steps
toward the description of the geometry of quantum constrained systems. We make
use of the geometric formulation of quantum theory in which unitary
transformations (including time evolution) can be seen, just as in the
classical case, as finite canonical transformations on the quantum state space.
We compare from this perspective the classical and quantum formalisms and argue
that there is an important difference between them, that suggests that the
condition on observables to become physical is through the double commutator
with the square of the constraint operator. This provides a bridge between the
standard Dirac procedure --through its geometric implementation-- and the
Master Constraint program.


title: Hot self-similar relativistic MHD flows

abstract:
  We consider axisymmetric relativistic jets with a toroidal magnetic field and
an ultrarelativistic equation of state, with the goal of studying the lateral
structure of jets whose pressure is matched to the pressure of the medium
through which they propagate. We find all self-similar steady-state solutions
of the relativistic MHD equations for this setup. One of the solutions is the
case of a parabolic jet being accelerated by the pressure gradient as it
propagates through a medium with pressure declining as p(z)\propto z^{-2}. As
the jet material expands due to internal pressure gradients, it runs into the
ambient medium resulting in a pile-up of material along the jet boundary, while
the magnetic field acts to produce a magnetic pinch along the axis of the jet.
Such jets can be in a lateral pressure equilibrium only if their opening angle
\theta_j at distance z is smaller than about 1/\gamma, where \gamma is the
characteristic bulk Lorentz-factor at this distance; otherwise, different parts
of the jet cannot maintain causal contact. We construct maps of optically thin
synchrotron emission from our self-similar models. We suggest that the boundary
pile-up may be the reason for the limb-brightening of the sub-parsec jet of
M87. We find that if the synchrotron emissivity falls with the distance from
the jet axis, the polarization fraction rises toward the edge, as seen in 3C273
and Mkn501. Projection effects and the emissivity pattern of the jet have a
strong effect on the observed polarization signal, so the interpretation of the
polarization data in terms of the geometry of magnetic fields is rather
uncertain. For example, jets with toroidal magnetic fields display the
`spine-sheath' polarization angle pattern seen in some BL Lac objects.


title: Decay and Continuity of Boltzmann Equation in Bounded Domains

abstract:
  Boundaries occur naturally in kinetic equations and boundary effects are
crucial for dynamics of dilute gases governed by the Boltzmann equation. We
develop a mathematical theory to study the time decay and continuity of
Boltzmann solutions for four basic types of boundary conditions: inflow,
bounce-back reflection, specular reflection, and diffuse reflection. We
establish exponential decay in $L^{\infty}$ norm for hard potentials for
general classes of smooth domains near an absolute Maxwellian. Moreover, in
convex domains, we also establish continuity for these Boltzmann solutions away
from the grazing set of the velocity at the boundary. Our contribution is based
on a new $L^{2}$ decay theory and its interplay with delicate $% L^{\infty}$
decay analysis for the linearized Boltzmann equation, in the presence of many
repeated interactions with the boundary.


title:
Models for Low-Mass X-Ray Binaries in the Elliptical Galaxies NGC3379
  and NGC4278: Comparison with Observations

abstract:
  We present theoretical models for the formation and evolution of populations
of low-mass X-ray binaries (LMXB) in the two elliptical galaxies NGC 3379 and
NGC 4278. The models are calculated with the recently updated StarTrack code
(Belczynski et al., 2006), assuming only a primordial galactic field LMXB
population. StarTrack is an advanced population synthesis code that has been
tested and calibrated using detailed binary star calculations and incorporates
all the important physical processes of binary evolution. The simulations are
targeted to modeling and understanding the origin of the X-ray luminosity
functions (XLF) of point sources in these galaxies. For the first time we
explore the population XLF down to luminosities of 3X10^36 erg/s, as probed by
the most recent observational results (Kim et al., 2006). We consider models
for the formation and evolution of LMXBs in galactic fields with different CE
efficiencies, stellar wind prescriptions, magnetic braking laws and initial
mass functions. We identify models that produce an XLF in excellent agreement
with the observations both in shape and absolute normalization. We also find
that the treatment of the outburst luminosity of transient systems remains a
crucial factor for the determination of the XLF since the modeled populations
are dominated by transient X-ray systems.


title: Spin 1/2 Fermions in the Unitary Limit.II

abstract:
  This report concerns the energy of a zero-temperature many-body system of
spin 1/2 fermions in the unitary limit. In a previous report (arXiv:0705.0944)
this energy was determined to be xi~0.24 in units of the free gas kinetic
energy, appreciably lower than most reports giving ~0.45$. In our calculation
the 2-body interaction satisfied exactly the unitary limit i.e. infinite
scattering length and effective range r_0=0. In the present report results with
r_0>0are shown. A strong dependence on the effective range is found. It is for
example found that an increase to r_0=1 fm increases xi to ~ 0.4 close to other
reports of xi in the unitary limit. It is concluded that because of the
singular character of the unitary limit it is necessary to verify that the
interaction actually satisfies unitarity.
  The calculations done here in a pp-ladder approximation show a resonance in
the in-medium interaction close to (and in) the unitary limit. This was already
found in the previous work.


title:
The Solvophobic Solvation and Interaction of Small Apolar Particles in
  Imidazolium-Based Ionic Liquids is Characterized by
  Enthalpy-/Entropy-Compensation

abstract:
  We report results of molecular dynamics simulations characterizing the
solvation and interaction of small apolar particles such as methane and Xenon
in imidazolium-based ionic liquids (ILs). The simulations are able to reproduce
semi-quantitatively the anomalous temperature dependence of the solubility of
apolar particles in the infinite dilution regime. We observe that the
``solvophobic solvation'' of small apolar particles in ILs is governed by
compensating entropic and enthalpic contributions, very much like the
hydrophobic hydration of small apolar particles in liquid water. In addition,
our simulations clearly indicate that the solvent mediated interaction of
apolar particles dissolved in ILs is similarly driven by compensating
enthalpic/entropic contributions, making the ``solvophobic interaction''
thermodynamically analogous to the hydrophobic interaction.


title:
An Extended Huckel Theory based Atomistic Model for Graphene
  Nanoelectronics

abstract:
  An atomistic model based on the spin-restricted extended Huckel theory (EHT)
is presented for simulating electronic structure and I-V characteristics of
graphene devices. The model is applied to zigzag and armchair graphene
nano-ribbons (GNR) with and without hydrogen passivation, as well as for
bilayer graphene. Further calculations are presented for electric fields in the
nano-ribbon width direction and in the bilayer direction to show electronic
structure modification. Finally, the EHT Hamiltonian and NEGF (Nonequilibrium
Green's function) formalism are used for a paramagnetic zigzag GNR to show
2e2/h quantum conductance.


title: Concave Programming Upper Bounds on the Capacity of 2-D Constraints

abstract:
  The capacity of 1-D constraints is given by the entropy of a corresponding
stationary maxentropic Markov chain. Namely, the entropy is maximized over a
set of probability distributions, which is defined by some linear requirements.
In this paper, certain aspects of this characterization are extended to 2-D
constraints. The result is a method for calculating an upper bound on the
capacity of 2-D constraints.
  The key steps are: The maxentropic stationary probability distribution on
square configurations is considered. A set of linear equalities and
inequalities is derived from this stationarity. The result is a concave
program, which can be easily solved numerically. Our method improves upon
previous upper bounds for the capacity of the 2-D ``no independent bits''
constraint, as well as certain 2-D RLL constraints.


title: The Unorthodox Orbits of Substructure Halos

abstract:
  (Abridged) We use cosmological N-body simulations to study the properties of
substructure halos in galaxy-sized dark matter halos. We extend prior work on
the subject by considering the whole population of subhalos physically
associated with the main system. These are defined as subhalos that have at
some time in the past been within the virial radius of the halo's main
progenitor and that have survived as self-bound entities to $z=0$. We find that
this population extends beyond {\it three times} the virial radius, and
contains objects on extreme orbits. We trace the origin of these unorthodox
orbits to the tidal dissociation of bound groups of subhalos, which results in
the ejection of some subhalos along tidal streams. Ejected subhalos are
primarily low-mass systems, leading to mass-dependent biases in their spatial
distribution and kinematics: the lower the subhalo mass at accretion time, the
less centrally concentrated and kinematically hotter their descendant
population. The bias is strongest amongst the most massive subhalos, but
disappears at the low-mass end. Our findings imply that subhalos identified
within the virial radius represent an incomplete census of the substructure
physically related to a halo: only about {\it one half} of all associated
subhalos are found today within the virial radius of a halo. These results may
explain the age dependence of the clustering of low-mass halos, and has
implications for (i) the interpretation of the structural parameters and
assembly histories of halos neighboring massive systems; (ii) the existence of
low-mass dynamical outliers in the Local Group; and (iii) the presence of
evidence for evolutionary effects well outside the traditional virial boundary
of a galaxy system.


title: Spin-Orbit Dynamics from the Gluon Asymmetry

abstract:
  Determination of the orbital angular momentum of the proton is a difficult
but important part of understanding fundamental structure. Insight can be
gained from suitable models of the gluon asymmetry applied to the Jz = 1/2 sum
rule. We have constrained the models of the asymmetry to gain possible
scenarios for the angular momentum of the proton's constituents. Results and
phenomenology for determining Lz are presented.


title:
Search for New Heavy Particles Decaying to Z^0 Z^0 -> eeee in p-pbar
  Collisions at sqrt(s) = 1.96 TeV

abstract:
  We report the results of a search for the anomalous production of a massive
particle decaying to four electrons via two Z^0 bosons in 1.1 fb^{-1} of p-pbar
collisions at sqrt(s)=1.96 TeV collected by the CDF II detector at Fermilab. We
employ optimized electron identification criteria to maximize acceptance and
efficiency. We estimate the backgrounds in the invariant mass range 500 - 1000
GeV/c^2 to be 0.028 +/- 0.009 (stat) +/- 0.011 (syst) events. We observe zero
events in this search region. Assuming a Randall-Sundrum graviton production
model, we set 95% CL limits on \sigma times BF(G -> Z^0 Z^0) < 4 - 6 pb,
depending on the graviton mass.


title:
Hessian and gradient estimates for three dimensional special Lagrangian
  Equations with large phase

abstract:
  We derive a priori interior Hessian and gradient estimates for special
Lagrangian equation of phase at least a critical value in dimension three.


title:
Reversible to Irreversible Flow Transition in Periodically Driven
  Vortices

abstract:
  We show that periodically driven superconducting vortices in the presence of
quenched disorder exhibit a transition from reversible to irreversible flow
under increasing vortex density or cycle period. This type of behavior has
recently been observed for periodically sheared colloidal suspensions and we
demonstrate that driven vortex systems exhibit remarkably similar behavior. We
also provide evidence that the onset of irreversible behavior is a dynamical
phase transition.


title: An Ap-Structure with Finslerian Flavor: I

abstract:
  A geometric structure (FAP-structure), having both absolute parallelism and
Finsler properties, is constructed. The building blocks of this structures are
assumed to be functions of position and direction. A non-linear connection
emerges naturally and is defined in terms of the building blocks of the
structure. Two linear connections, one of Berwald type and the other of the
Cartan type, are defined using the non-linear connection of the FAP. Both
linear connections are non-symmetric and consequently admit torsion. A metric
tensor is defined in terms of the building blocks of the structure. The
condition for this metric to be a Finslerian one is obtained. Also, the
condition for an FAP-space to be an AP-one is given.


title:
Monoidal categories of comodules for coquasi Hopf algebras and Radford's
  formula

abstract:
  We study the basic monoidal properties of the category of Hopf modules for a
coquasi Hopf algebra. In particular we discuss the so called fundamental
theorem that establishes a monoidal equivalence between the category of
comodules and the category of Hopf modules. We present a categorical proof of
Radford's $S^4$ formula for the case of a finite dimensional coquasi Hopf
algebra, by establishing a monoidal isomorphism between certain double dual
functors.


title:
New Measurement of the Electron Magnetic Moment and the Fine Structure
  Constant

abstract:
  A measurement using a one-electron quantum cyclotron gives the electron
magnetic moment in Bohr magnetons, g/2 = 1.001 159 652 180 73 (28) [0.28 ppt],
with an uncertainty 2.7 and 15 times smaller than for previous measurements in
2006 and 1987. The electron is used as a magnetometer to allow lineshape
statistics to accumulate, and its spontaneous emission rate determines the
correction for its interaction with a cylindrical trap cavity. The new
measurement and QED theory determine the fine structure constant, with
alpha^{-1} = 137.035 999 084 (51) [0.37 ppb], and an uncertainty 20 times
smaller than for any independent determination of alpha.