title: Relativistic tunneling and accelerated transmission

abstract:
  We obtain the solutions for the tunneling zone of a one-dimensional
electrostatic potential in the relativistic (Dirac to Klein-Gordon) wave
equation regime when the incoming wave packet exhibits the possibility of being
almost totally transmitted through the potential barrier. The conditions for
the occurrence of accelerated and, eventually, superluminal tunneling
transmission probabilities are all quantified and the problematic superluminal
interpretation originated from the study based on non-relativistic dynamics of
tunneling is overcome. The treatment of the problem suggests revealing insights
into condensed-matter experiments using electrostatic barriers in single- and
bi-layer graphene, for which the accelerated tunneling effect deserves a more
careful investigation.


title:
The coupling constants for an electroweak model with a $SU(4)_{PS}
  \otimes SU(4)_{EW}$ unification symmetry

abstract:
  We introduce the sequence of spontaneous symmetry breaking of a coupling
between Pati-Salam and electroweak symmetries $SU(4)_{PS} \otimes SU(4)_{EW}$
in order to establish a mathematically consistent relation among the coupling
constants at grand unification energy scale. With the values of baryon minus
lepton quantum numbers of known quarks and leptons, by including right-handed
neutrinos, we can find the mixing angle relations at different energy levels up
to the electromagnetic $U(1)_{EM}$ scale.


title:
Dirac neutrino mass from the beta decay end-point modified by the
  dynamics of a Lorentz-violating equation of motion

abstract:
  Using a generalized procedure for obtaining the equation of motion of a
propagating fermionic particle, we examine previous claims for a lightlike
preferred axis embedded in the framework of Lorentz-invariance violation with
preserved algebra. In a high energy scale, the corresponding equation of motion
is reduced to a conserving lepton number chiral (VSR) equation, and in a low
energy scale, the Dirac equation for a free is recovered. The new dynamics
introduces some novel ingredients (modified cross section) to the phenomenology
of the tritium beta decay end-point.


title:
Negative capacitance in organic semiconductor devices: bipolar injection
  and charge recombination mechanism

abstract:
  We report negative capacitance at low frequencies in organic semiconductor
based diodes and show that it appears only under bipolar injection conditions.
We account quantitatively for this phenomenon by the recombination current due
to electron-hole annihilation. Simple addition of the recombination current to
the well established model of space charge limited current in the presence of
traps, yields excellent fits to the experimentally measured admittance data.
The dependence of the extracted characteristic recombination time on the bias
voltage is indicative of a recombination process which is mediated by localized
traps.


title: Foundations of Relational Particle Dynamics

abstract:
  Relational particle dynamics include the dynamics of pure shape and cases in
which absolute scale or absolute rotation are additionally meaningful. These
are interesting as regards the absolute versus relative motion debate as well
as discussion of conceptual issues connected with the problem of time in
quantum gravity. In spatial dimension 1 and 2 the relative configuration spaces
of shapes are n-spheres and complex projective spaces, from which knowledge I
construct natural mechanics on these spaces. I also show that these coincide
with Barbour's indirectly-constructed relational dynamics by performing a full
reduction on the latter. Then the identification of the configuration spaces as
n-spheres and complex projective spaces, for which spaces much mathematics is
available, significantly advances the understanding of Barbour's relational
theory in spatial dimensions 1 and 2. I also provide the parallel study of a
new theory for which positon and scale are purely relative but orientation is
absolute. The configuration space for this is an n-sphere regardless of the
spatial dimension, which renders this theory a more tractable arena for
investigation of implications of scale invariance than Barbour's theory itself.


title:
Feedback in the Antennae Galaxies (NGC 4038/9): I. High-Resolution
  Infrared Spectroscopy of Winds from Super Star Clusters

abstract:
  We present high-resolution (R ~ 24,600) near-IR spectroscopy of the youngest
super star clusters (SSCs) in the prototypical starburst merger, the Antennae
Galaxies. These SSCs are young (3-7 Myr old) and massive (10^5 - 10^7 M_sun for
a Kroupa IMF) and their spectra are characterized by broad, extended Br-gamma
emission, so we refer to them as emission-line clusters (ELCs) to distinguish
them from older SSCs. The Brgamma lines of most ELCs have supersonic widths
(60-110 km/s FWHM) and non-Gaussian wings whose velocities exceed the clusters'
escape velocities. This high-velocity unbound gas is flowing out in winds that
are powered by the clusters' massive O and W-R stars over the course of at
least several crossing times. The large sizes of some ELCs relative to those of
older SSCs may be due to expansion caused by these outflows; many of the ELCs
may not survive as bound stellar systems, but rather dissipate rapidly into the
field population. The observed tendency of older ELCs to be more compact than
young ones is consistent with the preferential survival of the most
concentrated clusters at a given age.


title:
On the commuting charges for the highest dimension SU(2) operators in
  planar ${\cal N}=4$ SYM

abstract:
  We consider the highest anomalous dimension operator in the SU(2) sector of
planar ${\cal N}=4$ SYM at all-loop, though neglecting wrapping contributions.
In any case, the latter enter the loop expansion only after a precise
length-depending order. In the thermodynamic limit we write both a linear
integral equation for the Bethe root density and a linear system obeyed by the
commuting charges. Consequently, we determine the leading strong coupling
contribution to the density and from this an approximation to the leading and
sub-leading terms of any charge $Q_r$: it scales as $\lambda ^{1/4-r/2}$, which
generalises the Gubser-Klebanov-Polyakov energy law. In the end, we briefly
extend these considerations to finite lengths and 'excited' operators by using
the idea of a non-linear integral equation.


title: Rips complexes and covers in the uniform category

abstract:
  James \cite{Jam} introduced uniform covering maps as an analog of covering
maps in the topological category. Subsequently Berestovskii and Plaut
\cite{BP3} introduced a theory of covers for uniform spaces generalizing their
results for topological groups \cite{BP1}-\cite{BP2}. Their main concepts are
discrete actions and pro-discrete actions, respectively. In case of
pro-discrete actions Berestovskii and Plaut provided an analog of the universal
covering space and their theory works well for the so-called coverable spaces.
As will be seen in Section \ref{SECTION-Comparison}, \cite{BP3} generalizes
only regular covering maps in topology and pro-discrete actions may not be
preserved by compositions.
  In this paper we redefine the uniform covering maps and we generalize
pro-discrete actions using Rips complexes and the chain lifting property. We
expand the concept of generalized paths of Krasinkiewicz and Minc
\cite{KraMin}.


title: The UV-optical Galaxy Color-Magnitude Diagram I: Basic Properties

abstract:
  We have analyzed the bivariate distribution of galaxies as a function of
ultraviolet-optical colors and absolute magnitudes in the local universe. The
sample consists of galaxies with redshifts and optical photometry from the
Sloan Digital Sky Survey (SDSS) main galaxy sample matched with detections in
the near-ultraviolet (NUV) and far-ultraviolet (FUV) bands in the Medium
Imaging Survey being carried out by the Galaxy Evolution Explorer (GALEX)
satellite. In the (NUV-r)_{0.1} vs. M_{r,0.1} galaxy color-magnitude diagram,
the galaxies separate into two well-defined blue and red sequences. The
(NUV-r)_{0.1} color distribution at each M_{r,0.1} is not well fit by the sum
of two Gaussians due to an excess of galaxies in between the two sequences. The
peaks of both sequences become redder with increasing luminosity with a
distinct blue peak visible up to M_{r,0.1}\sim-23. The r_{0.1}-band luminosity
functions vary systematically with color, with the faint end slope and
characteristic luminosity gradually increasing with color. After correcting for
attenuation due to dust, we find that approximately one quarter of the color
variation along the blue sequence is due to dust with the remainder due to star
formation history and metallicity. Finally, we present the distribution of
galaxies as a function of specific star formation rate and stellar mass. The
specific star formation rates imply that galaxies along the blue sequence
progress from low mass galaxies with star formation rates that increase
somewhat with time to more massive galaxies with a more or less constant star
formation rate. Above a stellar mass of ~10^10.5 M_{sun}, galaxies with low
ratios of current to past averaged star formation rate begin to dominate.


title: Future Directions in Parity Violation: From Quarks to the Cosmos

abstract:
  I discuss the prospects for future studies of parity-violating (PV)
interactions at low energies and the insights they might provide about open
questions in the Standard Model as well as physics that lies beyond it. I cover
four types of parity-violating observables: PV electron scattering; PV hadronic
interactions; PV correlations in weak decays; and searches for the permanent
electric dipole moments of quantum systems.


title: The Northern Site of the Pierre Auger Observatory

abstract:
  The Pierre Auger Observatory is a multi-national project for research on
ultra-high energy cosmic rays. The Southern Auger Observatory in Mendoza
province, Argentina, is approaching completion in 2007 with an instrumented
area of 3,000 km^2. It will accurately measure the spectrum and composition of
ultra-high energy cosmic rays up to and beyond the predicted GZK feature. We
are obtaining results on the energy spectrum, mass composition and distribution
of arrival directions on the southern sky. The Northern Auger Observatory is
designed to complete and extend the investigations begun in the South. It will
establish charged particle astronomy and thus open a new window into the
universe. The distribution of arrival directions of the highest energy events
will point the way to unveiling the almost century old mystery of the origin
and nature of ultra-high energy cosmic rays. Achieving this goal requires
collecting many more events in spite of the steeply falling energy spectrum.
The planned northern site will have an instrumented area of 4,000 square miles
(10,370 km}^2 in Southeast Colorado, USA. The paper covers the science of
charged particle astronomy, the layout and the technical implementation of the
Northern Auger Observatory.


title:
Intrinsic alignments of galaxies and their effects on weak lensing
  detections of mass concentrations

abstract:
  In this paper we investigate the influence of the intrinsic alignment of
background galaxies on weak lensing detections of mass concentrations.
Specifically, we analyze the number counts of false peaks resulting from
intrinsic ellipticities in lensing convergence maps. Including the alignment of
source galaxies, the full noise variance from intrinsic ellipticites in
convergence $\kappa$-maps can be written as
$\sigma^2_0=\sigma^2_{0ran}+\sigma^2_{0corr}$, where $\sigma^2_{0ran}$ is the
noise contributed from randomly oriented source galaxies and $\sigma^2_{0corr}$
denotes the additional noise from intrinsic alignments. However, it is
observationally difficult to measure $\sigma^2_{0corr}$ and usually only
$\sigma^2_{0ran}$ can be estimated in weak lensing observations. Thus the
observational signal-to-noise ratio is often defined with respect to
$\sigma_{0ran}$, which is denoted as $\nu_{ran}$ in this paper. The true
signal-to-noise ratio $\nu$ in terms of $\sigma_0$ is then
$\nu=\nu_{ran}/(1+\sigma^2_{0corr}/\sigma^2_{0ran})^{1/2}$. Given a detection
threshold on $\nu_{ran}$, a larger value of $\sigma^2_{0corr}/\sigma^2_{0ran}$
leads to a lower threshold on $\nu$ and therefore a larger expected number of
false peaks. With $\sigma^2_{0corr}/\sigma^2_{0ran}\sim 10%$, the average
number of false peaks with $\nu_{ran}\ge 3.5$ nearly doubles compared to that
without considering the alignment, and for $\nu_{ran}\ge 5$, the number is
tripled. As a result, the efficiency of weak lensing cluster detection degrades
significantly. (Abridged)


title: Chiral Symmetries and Low Energy Searches for New Physics

abstract:
  I discuss low energy searches for new physics beyond the Standard Model,
identifying the role played by chiral symmetries in these searches and in
various new physics scenarios. I focus in particular on electric dipole moment
searches; precision studies of weak decays and electron scattering; and
neutrino properties and interactions.


title:
The globular cluster system in NGC5866: optical observations from HST
  Advanced Camera for Surveys

abstract:
  We perform a detailed study of the Globular Cluster (GC) system in the galaxy
NGC5866 based on F435W, F555W, and F625W (~ B, V, and R) HST Advanced Camera
for Surveys images.
  Adopting color, size and shape selection criteria, the final list of GC
candidates comprises 109 objects, with small estimated contamination from
background galaxies, and foreground stars.
  The color distribution of the final GC sample has a bimodal form. Adopting
color to metallicity transformations derived from the Teramo--SPoT simple
stellar population model, we estimate a metallicity [Fe/H]~ -1.5, and -0.6 dex
for the blue and red peaks, respectively. A similar result is found if the
empirical color-metallicity relations derived from Galactic GCs data are used.
  The two subpopulations show some of the features commonly observed in the GC
system of other galaxies, like a ``blue tilt'', higher central concentrations
of the red subsystem, and larger half--light radii at larger galactocentric
distances. However, we do not find evidence of a substantial difference between
the average sizes of red and blue clusters.
  Our analysis of the GC Luminosity Function indicates a V-band Turn-Over
Magnitude V$_0^{TOM}$=23.46+-0.06, or M$_{V,0}^{TOM}\sim-7.29 +- 0.10$ mag,
using the distance modulus derived from the average of SBF and the PNLF
distances. The absolute Turn-Over Magnitude obtained agrees well with
calibrations from literature. The specific frequency is measured to be $S_N=1.4
+- 0.3$, typical for galaxies of this type.


abstract:
  A new tetra-quark interpretation of X(3872) is presented. In this model,
X(3872) consists of two degenerate tetra-quark mesons, {[cn](cbar nbar) +-
(cn)[cbar nbar]}_{I=0}, and, therefore, it is naturally understood that X(3872)
decays into two different eigenstates of G-parity.


title: Slow light with integrated gain and large pulse delay

abstract:
  We demonstrate slow and stored light in Rb vapor with a combination of
desirable features: minimal loss and distortion of the pulse shape, and large
fractional delay (> 10). This behavior is enabled by: (i) a group index that
can be controllably varied during light pulse propagation; and (ii)
controllable gain integrated into the medium to compensate for pulse loss. Any
medium with the above two characteristics should be able to realize similarly
high-performance slow light.


title:
Phase diagram for a Bose-Einstein condensate moving in an optical
  lattice

abstract:
  The stability of superfluid currents in a system of ultracold bosons was
studied using a moving optical lattice. Superfluid currents in a very weak
lattice become unstable when their momentum exceeds 0.5 recoil momentum.
Superfluidity vanishes already for zero momentum as the lattice deep reaches
the Mott insulator(MI) phase transition. We study the phase diagram for the
disappearance of superfluidity as a function of momentum and lattice depth
between these two limits. Our phase boundary extrapolates to the critical
lattice depth for the superfluid-to-MI transition with 2% precision. When a
one-dimensional gas was loaded into a moving optical lattice a sudden
broadening of the transition between stable and unstable phases was observed.


title: Transient Lunar Phenomena: Regularity and Reality

abstract:
  Transient lunar phenomena (TLPs) have been reported for centuries, but their
nature is largely unsettled. A review of TLP reports shows regularities in the
observations; a key question is whether this structure is imposed by human
observer effects, terrestrial atmospheric effects or processes tied to the
lunar surface. I interrogate an extensive TLP catalog to determine if human
factors determine the distribution of TLP reports. I divide the sample
according to variables which should produce varying results if determining
factors involve humans e.g., historical epoch or geographical location of the
observer, not reflecting phenomena tied to the lunar surface. Regardless of how
we split the ample, the results are similar: ~50% of the reports involve crater
Aristarchus nd vicinity, ~16% from Plato, ~6% from other recent, major impacts,
plus a few at Grimaldi. Mare Crisium produces a robust signal for three of five
averages of up to 7% of the reports (however, Crisium is an extended feature).
The consistency in TLP report counts for specific features indicates that >~80%
of reports are consistent with being real (perhaps excepting Crisium). Some
commonly reported sites disappear from the robust averages, including
Alphonsus, Ross D and Gassendi. TLP reports supporting these sites originate
almost entirely after year 1955, when TLPs became more popular targets of
observation and many more (and inexperienced) observers searched for TLPs. In a
companion paper, we compare the spatial distribution of robust TLP sites of
transient outgassing (seen on Apollo and Lunar Prospector). To a high
confidence against the random hypothesis, robust TLP sites and those of lunar
outgassing correlate strongly, further arguing for the reality of TLPs.
[Abstract abridged.]


title:
Metal-insulator transition in the two-orbital Hubbard model at
  fractional band fillings: Self-energy functional approach

abstract:
  We investigate the infinite-dimensional two-orbital Hubbard model at
arbitrary band fillings. By means of the self-energy functional approach, we
discuss the stability of the metallic state in the systems with same and
different bandwidths. It is found that the Mott insulating phases are realized
at commensurate band fillings. Furthermore, it is clarified that the orbital
selective Mott phase with one orbital localized and the other itinerant is
stabilized even at fractional band fillings in the system with different
bandwidths.


title:
Lunar Outgassing, Transient Phenomena and The Return to The Moon, I:
  Existing Data

abstract:
  Herein the transient lunar phenomena (TLP) report database is subjected to a
discriminating statistical filter robust against sites of spurious reports, and
produces a restricted sample that may be largely reliable. This subset is
highly correlated geographically with the catalog of outgassing events seen by
the Apollo 15, 16 and Lunar Prospector alpha-particle spectrometers for
episodic Rn-222 gas release. Both this robust TLP sample and even the larger,
unfiltered sample are highly correlated with the boundary between mare and
highlands, as are both deep and shallow moonquakes, as well as Po-210, a
long-lived product of Rn-222 decay and a further tracer of outgassing. This
offers another significant correlation relating TLPs and outgassing, and may
tie some of this activity to sagging mare basalt plains (perhaps mascons).
Additionally, low-level but likely significant TLP activity is connected to
recent, major impact craters (while moonquakes are not), which may indicate the
effects of cracks caused by the impacts, or perhaps avalanches, allowing
release of gas. The majority of TLP (and Rn-222) activity, however, is confined
to one site that produced much of the basalt in the Procellarum Terrane, and it
seems plausible that this TLP activity may be tied to residual outgassing from
the formerly largest volcanic ffusion sites from the deep lunar interior. With
the coming in the next few years of robotic spacecraft followed by human
exploration, the study of TLPs and outgassing is both promising and imperiled.
We will have an unprecedented pportunity to study lunar outgassing, but will
also deal with a greater burden of anthropogenic lunar gas than ever produced.
There is a pressing need to study lunar atmosphere and its sources while still
pristine. [Abstract abridged.]


title:
Thorn independence in the field of real numbers with a small
  multiplicative group

abstract:
  We characterize thorn-independence in a variety of structures, focusing on
the field of real numbers expanded by predicate defining a dense multiplicative
subgroup, G, satisfying the Mann property and whose pth powers are of finite
index in G. We also show such structures are super-rosy and eliminate
imaginaries up to codes for small sets.


title: Extending SU(2) to SU(N) QCD

abstract:
  Abelian dominance is used to reformulate the QCD Lagrangian as a sum over the
roots of Lie group representation theory. This greatly facilitates extending
the SU(2) magnetic ground state energy spectrum, several arguments for the
stability of the magnetic ground state, and the Faddeev-Skyrme model to
arbitrary SU(N) QCD.


title:
Lunar Outgassing, Transient Phenomena and The Return to The Moon, II:
  Predictions for Interactions between Outgassing and Regolith

abstract:
  We consider the implications from Paper I on how gas leaking through the
lunar surface might interact with the regolith, and in what respects this might
affect or cause the appearance of optical Transient Lunar Phenomena (TLPs). We
consider briefly a range of phenomena, but concentrate at the extremes of high
and low gas flow rate, which might represent the more likely behaviors.
Extremely fast i.e., explosive, expulsion of gas from the surface is
investigated by examining the minimal amount of gas needed to displace a plug
of regolith above a site of gaseous overpressure at the regolith's base. The
area and timescale of this disturbance, it is consistent with observed TLPs.
Furthermore there are several ways in which such an explosion might be expected
to change the lunar surface appearance in a way consistent with many TLPs,
including production of obscuration, brightening and color changes. At the slow
end of the volatile flow range, gas seeping from the interior is retained below
the surface for extensive times due to the low diffusivity of regolith
material. A special circumstance arises if the volatile flow contains water
vapor, because water is uniquely capable of freezing as it passes from the base
to the surface of the regolith. For a large TLP site, it is plausible to think
of areas on the square-km scale accumulating significant bodies of water ice.
Furthermore, as the system evolves over geological time, the ice accumulation
zone will evolve downwards into the regolith. Since many reactions possible
between the volatiles and regolith, depending on the additional gases besides
water, can act to decrease diffusivity in the regolith, it is plausible that
the volatiles produce a barrier between the seepage source and vacuum, forcing
the ice zone to expand to larger areas.


title:
Maps between moduli spaces of vector bundles and the base locus of the
  theta divisor

abstract:
  Given a vector bundle $E$ of rank $r$ and degree $d$ on a curve $C$ of genus
$g$, one can associate to $E$ in a natural way several other vector bundles.
For example, one can take wedge powers of $E$. If $E$ is generated by global
sections, the kernel of the evaluation map of sections is again a vector
bundle. Also, new vector bundles can be produced by taking elementary
transformations centered at a fixed point. Under suitable conditions on degree
and rank, these constructions can be carried out globally. While all this
processes seem quite elementary, very little is known about the resulting maps.
The purpose of this paper is to fill in this gap.


title:
Lunar Outgassing, Transient Phenomena and The Return to The Moon, III:
  Observational and Experimental Techniques

abstract:
  In Papers II and III we show that Transient Lunar Phenomena (TLPs) are likely
related to lunar outgassing, albeit in ways not fully understood. Here we
propose a path forward, in which current and forthcoming technologies provide a
more controlled, sensitive probe of lunar outgassing. Many of these techniques
are being realized for the first time. Given the optical transient/outgassing
connection, progress can be made by remote sensing, and we suggest programs of
imaging, spectroscopy and combinations thereof. However, as found in Paper II,
many aspects of lunar outgassing seem covert in nature. TLPs betray outgassing,
but not all outgassing produces TLPs. Some outgassing may never appear at the
surface, but remain trapped in the regolith. We also suggest more intrusive
techniques, from radar mapping to in-situ probes. Understanding these volatiles
seems promising in terms of a resource for humans on the Moon and beyond, and
offers an interesting scientific goal in its own right. Hence this paper is a
series of proposed techniques, some in practice, some which might be soon, and
some requiring significant future investment, some of which may prove unwise
pending results from predecessor investigations. These point towards
enhancement of our knowledge of lunar outgassing, its relation to other lunar
processes, and an increase in our understanding of how volatiles are involved
in the evolution of the Moon. We emphasize certain ground-based observations in
time for flights of SELENE, LRO and other robotic missions, and others before
extensive human xploration. We discuss how study of the pristine lunar
atmosphere pertains to understanding the role of anthropogenic volatiles, an
important confusing signal


title:
Study of charmonia in four-meson final states produced in two-photon
  collisions

abstract:
  We report measurements of charmonia produced in two-photon collisions and
decaying to four-meson final states, where the meson is either a charged pion
or a charged kaon. The analysis is based on a 395fb^{-1} data sample
accumulated with the Belle detector at the KEKB electron-positron collider. We
observe signals for the three C-even charmonia eta_c(1S), chi_{c0}(1P) and
chi_{c2}(1P) in the pi^+pi^-pi^+pi^-, K^+K^-pi^+pi^- and K^+K^-K^+K^- decay
modes. No clear signals for eta_c(2S) production are found in these decay
modes. We have also studied resonant structures in charmonium decays to
two-body intermediate meson resonances. We report the products of the
two-photon decay width and the branching fractions, Gamma_{gamma gamma}B, for
each of the charmonium decay modes.


title: Long-time tails in freely cooling granular gases

abstract:
  The long-time behavior of the current auto-correlation functions for the
velocity, the shear stress and the heat flux is investigated in freely cooling
granular gases. It is found that the correlation functions for the velocity and
the shear stress have the long-time tails obeying $\tau^{-d/2}$, while the
correlation function of heat flux decays as $\tau^{-(d+2)/2} \exp(-\zeta^*
\tau)$ with the dimensionless cooling rate $\zeta^*$, the spatial dimension $d$
and the scaled time $\tau$ in terms of the collision frequency. The result of
our numerical simulation of the freely cooling granular gases is consistent
with the theoretical prediction.


title: Notes on $\pi_1$ of Smooth Loci of Log Del Pezzo Surfaces

abstract:
  It is known that the fundamental groups of smooth loci of Log del Pezzo
Surfaces are finite groups. The aim of this note is to study these finite
groups. A short table containing these groups is given. And lots of groups on
the table are proved to be fundamental groups.


title:
Di-jet hadron pair correlation in a hydrodynamical model with a
  quenching jet

abstract:
  In jet quenching, a hard QCD parton, before fragmenting into a jet of
hadrons, deposits a fraction of its energy in the medium, leading to suppressed
production of high-$p_T$ hadrons. Assuming that the deposited energy quickly
thermalizes, we simulate the subsequent hydrodynamic evolution of the QGP
fluid. Hydrodynamic evolution and subsequent particle emission depend on the
jet trajectories. Azimuthal distribution of excess $\pi^-$ due to quenching
jet, averaged over all the trajectories, reasonably well reproduce the
di-hadron correlation as measured by the STAR and PHENIX collaboration in
central and in peripheral Au+Au collisions.


title: Self-Similar Dynamics of a Magnetized Polytropic Gas

abstract:
  In broad astrophysical contexts of large-scale gravitational collapses and
outflows and as a basis for various further astrophysical applications, we
formulate and investigate a theoretical problem of self-similar MHD for a
non-rotating polytropic gas of quasi-spherical symmetry permeated by a
completely random magnetic field. We derive two coupled nonlinear MHD ordinary
differential equations (ODEs), examine properties of the magnetosonic critical
curve, obtain various asymptotic and global semi-complete similarity MHD
solutions, and qualify the applicability of our results. Unique to a magnetized
gas cloud, a novel asymptotic MHD solution for a collapsing core is
established. Physically, the similarity MHD inflow towards the central dense
core proceeds in characteristic manners before the gas material eventually
encounters a strong radiating MHD shock upon impact onto the central compact
object. Sufficiently far away from the central core region enshrouded by such
an MHD shock, we derive regular asymptotic behaviours. We study asymptotic
solution behaviours in the vicinity of the magnetosonic critical curve.
Numerically, we construct global semi-complete similarity MHD solutions that
cross the magnetosonic critical curve zero, one, and two times. For comparison,
counterpart solutions in the case of an isothermal unmagnetized and magnetized
gas flows are demonstrated in the present MHD framework at nearly isothermal
and weakly magnetized conditions. For a polytropic index $\gamma=1.25$ or a
strong magnetic field, different solution behaviours emerge. In these cases,
there exist semi-complete similarity solutions crossing the magnetosonic
critical curve only once, and the MHD counterpart of expansion-wave collapse
solution disappears.


title: Kaluza-Klein Gluons as a Diagnostic of Warped Models

abstract:
  We study the properties of $g^{1}$, the first excited state of the gluon in
representative variants of the Randall Sundrum model with the Standard Model
fields in the bulk. We find that measurements of the coupling to light quarks
(from the inclusive cross-section for $pp\to g^{1} \to t\bar t$), the coupling
to bottom quarks (from the rate of $pp\to g^{1} b$), as well as the overall
width, can provide powerful discriminants between the models. In models with
large brane kinetic terms, the $g^1$ resonance can even potentially be
discovered decaying into dijets against the large QCD background. We also
derive bounds based on existing Tevatron searches for resonant $t \bar{t}$
production and find that they require $M_{g^{1}} \gtrsim 950$ GeV. In addition
we explore the pattern of interference between the $g^1$ signal and the
non-resonant SM background, defining an asymmetry parameter for the invariant
mass distribution. The interference probes the relative signs of the couplings
of the $g^{1}$ to light quark pairs and to $t\bar t$, and thus provides an
indication that the top is localized on the other side of the extra dimension
from the light quarks, as is typical in the RS framework.


title: Extra dimensions and atomic transition frequencies

abstract:
  New unification theories predict Large Extra Dimensions (LEDs). If that is
the case, gravity would be stronger at short ranges than what Newtonian gravity
predicts. LEDs could also have effects at atomic level. In this paper we
propose a new method to constrain the size of gravity-only LEDs by analyzing
how these LEDs modify the energy of the atomic transitions 1s-2s and 2s-2p
(Lamb shift), for the particular case of the hydrogen and muonium atoms. We
estimate these effects by using Bethe's non-relativistic treatment of Lamb
shift. For the particular case of three LEDs, which may be a candidate to
explain the interaction mechanism of dark matter particles, we have found that
current knowledge in atomic spectroscopy could constrain their sizes to be less
than 10 * 10^(-6) m. Although our contributions do not reach the sensitivity
given by SN1987a, they are still slightly better than recent constraints given
by Inverse Square Law tests of Eot-Wash group at Washington University, which
gave R3 < 36.6 * 10^(-6) m.


title: Quantum measurement, detection and locality

abstract:
  According to Bell's theorem, local realism is incompatible with quantum
theory. However, it depends on an implied assumption about quantum measurement.
We suggest that the assumption might be removed by a detailed quantum analysis
of the interaction between the measured system and measuring apparatus using
Born's statistical interpretation. But it is conceivable that detailed analysis
of all possible Bell experiments would allow the compatibility of quantum
theory and local realism. The difficulties of theory and experiment are closely
related.


title: Carbonates in space - The challenge of low temperature data

abstract:
  Carbonates have repeatedly been discussed as possible carriers of stardust
emission bands. However, the band assignments proposed so far were mainly based
on room temperature powder transmission spectra of the respective minerals.
Since very cold calcite grains have been claimed to be present in protostars
and in Planetary Nebulae such as NGC 6302, the changes of their dielectric
functions at low temperatures are relevant from an astronomical point of view.
We have derived the IR optical constants of calcite and dolomite from
reflectance spectra - measured at 300, 200, 100 and 10K - and calculated small
particle spectra for different grain shapes, with the following results: i) The
absorption efficiency factors both of calcite and dolomite are extremely
dependent on the particle shapes. This is due to the high peak values of the
optical constants of CaCO3 and CaMg[CO3]2. ii) The far infrared properties of
calcite and dolomite depend also very significantly on the temperature. Below
200K, a pronounced sharpening and increase in the band strengths of the FIR
resonances occurs. iii) In view of the intrinsic strength and sharpening of the
44 mum band of calcite at 200-100K, the absence of this band -- inferred from
Infrared Space Observatory data -- in PNe requires dust temperatures below 45K.
iv) Calcite grains at such low temperatures can account for the '92' mum band,
while our data rule out dolomite as the carrier of the 60-65 mum band. The
optical constants here presented are publicly available in the electronic
database http://www.astro.uni-jena.de/Laboratory/OCDB


abstract:
  We consider compact hyperbolic Coxeter polytopes whose Coxeter diagram
contains a unique dotted edge. We prove that such a polytope in d-dimensional
hyperbolic space has at most d+3 facets. In view of results of Lann\'er,
Kaplinskaja, Esselmann, and the second author, this implies that compact
hyperbolic Coxeter polytopes with a unique pair of non-intersecting facets are
completely classified. They do exist only up to dimension 6 and in dimension 8.


title:
Unambiguous symmetry assignment for the top valence band of ZnO by
  magneto-optical studies of the free A-exciton state

abstract:
  We studied the circular polarization and angular dependences of the
magneto-photoluminescence spectra of the free A-exciton 1S state in wurtzite
ZnO at T = 5 K. The circular polarization properties of the spectra clearly
indicate that the top valence band has Gamma_7 symmetry. The out-of-plane
component of the magnetic field, which is parallel to the sample's c axis,
leads to linear Zeeman splitting of both the dipole-allowed Gamma_5 exciton
state and the weakly allowed Gamma_1/Gamma_2 exciton states. The in-plane
field, which is perpendicular to the c axis, increases the oscillator strength
of the weak Gamma_1/Gamma_2 states by forming a mixed exciton state.


title:
A double-slit `which-way' experiment on the complementarity--uncertainty
  debate

abstract:
  A which-way measurement in Young's double-slit will destroy the interference
pattern. Bohr claimed this complementarity between wave- and particle behaviour
is enforced by Heisenberg's uncertainty principle: distinguishing two positions
a distance s apart transfers a random momentum q \sim \hbar/s to the particle.
This claim has been subject to debate: Scully et al. asserted that in some
situations interference can be destroyed with no momentum transfer, while
Storey et al. asserted that Bohr's stance is always valid. We address this
issue using the experimental technique of weak measurement. We measure a
distribution for q that spreads well beyond [-\hbar/s, \hbar/s], but
nevertheless has a variance consistent with zero. This weakvalued
momentum-transfer distribution P_{wv}(q) thus reflects both sides of the
debate.


title: Revisiting Rotational Perturbations and the Microwave Background

abstract:
  We consider general-relativistic rotational perturbations in homogeneous and
isotropic Friedman - Robertson - Walker (FRW) cosmologies. Taking linear
perturbations of FRW models, the general solution of the field equations
contains tensorial, vectorial and scalar functions. The vectorial terms are in
connection with rotations in the given model and due to the Sachs - Wolfe
effect they produce contributions to the temperature fluctuations of the cosmic
microwave background radiation (CMBR). In present paper we obtain the analytic
time dependence of these contributions in a spatially flat, FRW model with
pressureless ideal fluid, in the presence and the absence of a cosmological
constant. We find that the solution can be separated into an integrable and a
non-integrable part as is the situation in the case of scalar perturbations.
Analyzing the solutions and using the results of present observations we
estimate the order of magnitude of the angular velocity corresponding to the
rotation tensor at the time of decoupling and today.


title: Multiscale inference about a density

abstract:
  We introduce a multiscale test statistic based on local order statistics and
spacings that provides simultaneous confidence statements for the existence and
location of local increases and decreases of a density or a failure rate. The
procedure provides guaranteed finite-sample significance levels, is easy to
implement and possesses certain asymptotic optimality and adaptivity
properties.


title: Passage Times for Polymer Translocation Pulled through a Narrow Pore

abstract:
  We study the passage times of a translocating polymer of length $N$ in three
dimensions, while it is pulled through a narrow pore with a constant force $F$
applied to one end of the polymer. At small to moderate forces, satisfying the
condition $FN^{\nu}/k_BT\lesssim1$, where $\nu\approx0.588$ is the Flory
exponent for the polymer, we find that $\tau_N$, the mean time the polymer
takes to leave the pore, scales as $N^{2+\nu}$ independent of $F$, in agreement
with our earlier result for F=0. At strong forces, i.e., for
$FN^{\nu}/k_BT\gg1$, the behaviour of the passage time crosses over to
$\tau_N\sim N^2/F$. We show here that these behaviours stem from the polymer
dynamics at the immediate vicinity of the pore -- in particular, the memory
effects in the polymer chain tension imbalance across the pore.

categories: cond-mat.soft cond-mat.stat-mech physics.bio-ph q-bio.BM


title: Raynaud vector bundles

abstract:
  We construct vector bundles $R^r_\mu$ on a smooth projective curve $X$ having
the property that for all sheaves $E$ of slope $\mu$ and rank $r$ on $X$ we
have an equivalence: $E$ is a semistable vector bundle $\iff$
$Hom(R^r_\mu,E)=0$.
  As a byproduct of our construction we obtain effective bounds on $r$ such
that the linear system $|R \cdot \Theta|$ has base points on the moduli space
$U_X(r,r(g-1))$.


title: On the L^p-distorsion of finite quotients of amenable groups

abstract:
  We study the L^p-distortion of finite quotients of amenable groups. In
particular, for every number p larger or equal than 2, we prove that the
l^p-distortion of the finite lamplighter group grows like (\log n)^{1/p}. We
also give the asymptotic behavior of the l^p-distortion of finite quotients of
certain metabelian polycyclic groups and of the solvable Baumslag-Solitar
groups BS(m,1). The proofs are short and elementary.


title:
XMM-Newton observation of the persistent Be/neutron-star system X Persei
  at a high-luminosity level

abstract:
  We report on the XMM-Newton observation of the HMXRB X Persei, the prototype
of the persistent and low-luminosity Be/neutron star pulsars, which was
performed on February 2003. The source was detected at a luminosity level of ~
1.4x10^35 erg/s, which is the highest level of the latest three decades. The
pulsation period has increased up to 839.3 s, thus confirming the overall
spin-down of the NS detected in the previous observations. The folded
light-curve has a complex structure, with features not observed at lower
luminosities, and shows a significant energy dependence. The spectral analysis
reveals the presence of a significant excess at low energies over the main
power-law spectral component, which can be described by a black-body spectrum
of high temperature (kT_BB ~ 1.5 keV) and small emitting region (R_BB ~ 340 m);
its properties are consistent with a polar-cap origin. Phase-resolved
spectroscopy shows that the emission spectrum varies along the pulse period,
but it is not possible to prove whether the thermal component is pulsed or not.


title: Whitehead-Torsion und Faserungen

abstract:
  This work treats on the question whether a given map f: M -> B of smooth
closed manifolds is homotopic to a smooth fiber bundle. We define a first
obstruction in H^1(B;Wh(\pi_1(E))) and, provided that this obstruction vanishes
and one additional condition is verified, a second obstruction in Wh(\pi_1(E))
>. Both elements vanish if the answer to the above question is positive. In the
case where B is the 1-sphere and the dimension of M exceeds five, we show that
the converse is also true, using a relationship with two obstructions defined
by Farrell in this particular situation.


title: Kinetic and hydrodynamic models of chemotactic aggregation

abstract:
  We derive general kinetic and hydrodynamic models of chemotactic aggregation
that describe certain features of the morphogenesis of biological colonies
(like bacteria, amoebae, endothelial cells or social insects). Starting from a
stochastic model defined in terms of N coupled Langevin equations, we derive a
nonlinear mean field Fokker-Planck equation governing the evolution of the
distribution function of the system in phase space. By taking the successive
moments of this kinetic equation and using a local thermodynamic equilibrium
condition, we derive a set of hydrodynamic equations involving a damping term.
In the limit of small frictions, we obtain a hyperbolic model describing the
formation of network patterns (filaments) and in the limit of strong frictions
we obtain a parabolic model which is a generalization of the standard
Keller-Segel model describing the formation of clusters (clumps). Our approach
connects and generalizes several models introduced in the chemotactic
literature. We discuss the analogy between bacterial colonies and
self-gravitating systems and between the chemotactic collapse and the
gravitational collapse (Jeans instability). We also show that the basic
equations of chemotaxis are similar to nonlinear mean field Fokker-Planck
equations so that a notion of effective generalized thermodynamics can be
developed.


title: Hierarchical Spatial Organization of Geographical Networks

abstract:
  In this work we propose the use of a hirarchical extension of the
polygonality index as a means to characterize and model geographical networks:
each node is associated with the spatial position of the nodes, while the edges
of the network are defined by progressive connectivity adjacencies. Through the
analysis of such networks, while relating its topological and geometrical
properties, it is possible to obtain important indications about the
development dynamics of the networks under analysis. The potential of the
methodology is illustrated with respect to synthetic geographical networks.


title: Towards an Experimental Test of Gravity-induced Quantum State Reduction

abstract:
  According to the hypothesis of Penrose and Diosi, quantum state reduction is
a manifestation of the incompatibilty of general relativity and the unitary
time evolution of quantum physics. Dimensional analysis suggests that
Schrodinger cat type states should collapse on measurable time scales when
masses and lengths of the order of bacterial scales are involved. We analyze
this hypothesis in the context of modern developments in condensed matter and
cold atoms physics, aimed at realizing macroscopic quantum states. We first
consider 'micromechanical' quantum states, analyzing the capacity of an atomic
force microscopy based single spin detector to measure the gravitational state
reduction, but we conclude that it seems impossible to suppress environmental
decoherence to the required degree. We subsequently discuss 'split' cold atom
condensates to find out that these are at present lacking the required mass
scale by many orders of magnitude. We then extent Penrose's analysis to
superpositions of mass current carrying states, and we apply this to the flux
quantum bits realized in superconducting circuits. We find that the flux qubits
approach the scale where gravitational state reduction should become
measurable, but bridging the few remaining orders of magnitude appears to be
very difficult with present day technology.


title:
Multipolar expansion of the electrostatic interaction between charged
  colloids at interfaces

abstract:
  The general form of the electrostatic potential around an arbitrarily charged
colloid at an interface between a dielectric and a screening phase (such as air
and water, respectively) is analyzed in terms of a multipole expansion. The
leading term is isotropic in the interfacial plane and varies with $d^{-3}$
where $d$ is the in--plane distance from the colloid. The electrostatic
interaction potential between two arbitrarily charged colloids is likewise
isotropic and $\propto d^{-3}$, corresponding to the dipole--dipole interaction
first found for point charges at water interfaces. Anisotropic interaction
terms arise only for higher powers $d^{-n}$ with $n \ge 4$.


title: Holographic heavy-light mesons from non-Abelian DBI

abstract:
  In the context of gauge/gravity duals with flavor, we examine heavy-light
mesons which involve a heavy and a light quark. For this purpose we embed two
D7 brane probes at different positions into the gravity background. We
establish the non-Abelian Dirac-Born-Infeld (DBI) action for these probes, in
which the U(2) matrix describing the embedding is diagonal. The fluctuations of
the brane probes correspond to the mesons. In particular, the off-diagonal
elements of the U(2) fluctuation matrix correspond to the heavy-light mesons,
while the diagonal elements correspond to the light-light and heavy-heavy
mesons, respectively. The heavy-light mesons scale differently with the 't
Hooft coupling than the mesons involving quarks of equal mass. The model
describes both scalar and vector mesons. For different dilaton-deformed gravity
backgrounds, we also calculate the Wilson loop energy, and compare with the
meson masses.


title: The informational model - possible tests

abstract:
  In our previous arXiv papers (more systematically the informational
conception is presented in the paper "The Information as Absolute", 2010) it
was rigorously shown that Matter in our Universe - and Universe as a whole -
are some informational systems (structures), which exist as uninterruptedly
transforming [practically] infinitesimal sub-sets in the absolutely infinite
and fundamental set "Information". Such a conception allows to suggest a
reasonable physical model that is based on the conjecture that Matter is some
analogue of computer (more correct - of a [huge] number of mutually
comparatively independent automata). The conjecture, in turn, allows
introducing in the model the basic logical elements that constitute the
material structures and support the informational exchange - i.e. the forces -
between the structures. The model yet now makes more clear a number of basic
problems in special relativity, quantum mechanics, and, rather probably, in
[now - in Newtonian] gravity. In this paper some possible experiments for the
model testing are considered.


title: Fluctuation Propagator and Heavy Quark Diffusion

abstract:
  The quark fluctuation propagator is evaluated. It defines the diffusion
coefficient in the vicinity of the phase transition and the gradient term in
the Ginzburg-Landau functional.


title: On the Greenfield-Wallach and Katok conjectures

abstract:
  We survey recent progress on the Greenfield-Wallach and Katok conjectures on
globally hypoelliptic and cohomology free vector fields and derive a proof of
the conjectures in dimension three. The argument is primarily based on recent
work of F. and J. Rodriguez Hertz which allows us to reduce the question to the
case of a Reeb flow for a contact form. The contact case is settled by invoking
the Weinstein conjecture (which has been recently announced by C. Taubes).


title: Lorentz anomaly in the semi-light-cone gauge superstrings

abstract:
  We study the Lorentz invariance of D=4 and 6 superstrings in the
double-spinor formalism, which are equivalent to the D=4 and 6 superstrings in
the pure-spinor formalism in the sense of the BRST cohomology. We first
re-examine how the conformal and Lorentz anomalies appear in the D=4 and 6
Green-Schwarz superstrings in the semi-light-cone gauge in the framework of
BRST quantization. We construct a set of BRST invariant Lorentz generators and
show that they do not form a closed algebra, even cohomologically. We then turn
to the construction of Lorentz generators in the D=4 and 6 double-spinor
superstrings, and show that the Lorentz invariance is again anomalous. We also
discuss the relation between the anomaly-free Lorentz generators in the
lower-dimensional pure-spinor formalisms and that obtained in this paper.


title: Social applications of two-dimensional Ising models

abstract:
  I review three socio-economic models of economic opinions, urban segregation,
and language change and show that the well known two-dimensional Ising model
gives about the same results in each case.


title: A Comparison of Push and Pull Techniques for Ajax

abstract:
  Ajax applications are designed to have high user interactivity and low
user-perceived latency. Real-time dynamic web data such as news headlines,
stock tickers, and auction updates need to be propagated to the users as soon
as possible. However, Ajax still suffers from the limitations of the Web's
request/response architecture which prevents servers from pushing real-time
dynamic web data. Such applications usually use a pull style to obtain the
latest updates, where the client actively requests the changes based on a
predefined interval. It is possible to overcome this limitation by adopting a
push style of interaction where the server broadcasts data when a change occurs
on the server side. Both these options have their own trade-offs. This paper
explores the fundamental limits of browser-based applications and analyzes push
solutions for Ajax technology. It also shows the results of an empirical study
comparing push and pull.


title:
Distributions associated with general runs and patterns in hidden Markov
  models

abstract:
  This paper gives a method for computing distributions associated with
patterns in the state sequence of a hidden Markov model, conditional on
observing all or part of the observation sequence. Probabilities are computed
for very general classes of patterns (competing patterns and generalized later
patterns), and thus, the theory includes as special cases results for a large
class of problems that have wide application. The unobserved state sequence is
assumed to be Markovian with a general order of dependence. An auxiliary Markov
chain is associated with the state sequence and is used to simplify the
computations. Two examples are given to illustrate the use of the methodology.
Whereas the first application is more to illustrate the basic steps in applying
the theory, the second is a more detailed application to DNA sequences, and
shows that the methods can be adapted to include restrictions related to
biological knowledge.


title:
Positivity of Some Integral Transforms, and Generalization of Bochner's
  Theorem on Functions of Positive Type

abstract:
  Using the integral representations of the solutions of Schr\"odinger
equation, which are the essential ingredients of the Gel'fand-Levitan and
Marchenko integral equations of inverse scattering theory, we obtain a general
theorem on the positivity of some integral transforms, and extend the theorem
of Bochner on Fourier transforms of functions of positive type to more general
transforms. The present study is restricted to the positive half-axis. We then
obtain a theorem on the positivity of Fourier cosine transform of the
phase-shifts.


title: Exciting the quark-gluon plasma with a relativistic jet

abstract:
  We discuss the properties of a system composed by a static plasma traversed
by a jet of particles. Assuming that both the jet and the plasma can be
described using a hydrodynamical approach, and in the conformal limit, we find
that unstable modes arise when the velocity of the jet is larger than the speed
of the sound of the plasma and only modes with momenta smaller than a certain
values are unstable. Moreover, for ultrarelativistic velocities of the jet the
most unstable modes correspond to relative angles between the velocity of the
jet and momentum of the collective mode ~ pi/4. Our results suggest an
alternative mechanism for the description of the jet quenching phenomenon,
where the jet crossing the plasma loses energy exciting colored unstable modes.
In LHC this effect should be seen with an enhanced production of hadrons for
some specific values of their momenta and in certain directions of momenta
space.


title: 5-dimensional solution with acceleration and small variation of G

abstract:
  A 5-dimensional cosmological solution in the model with two 2-forms and two
``phantom'' scalar fields is considered. The model contains two dilatonic
coupling vectors obeying certain restrictions. It is shown that there exists a
time interval where accelerating expansion of ``our'' 3-dimensional space is
compatible with a small value of effective gravitational ``constant''
variation.


title:
Hans-Juergen Treder and the discovery of confinement in Einstein's
  unified field theory

abstract:
  In the year 1957, when interest in Einstein's unified field theory was fading
away for lack of understanding of its physical content, Treder performed a
momentous critical analysis of the possible definitions of the electric
four-current in the theory. As an outcome of this scrutiny he was able to prove
by the E.I.H. method that properly defined point charges, appended at the
right-hand side of the field equation $R_{[[\mu\nu],\lambda]}=0$, interact
mutually with Coulomb-like forces, provided that a mutual force independent of
distance is present too. This unwanted, but unavoidable addition, could not but
lay further disbelief on the efforts initiated by Einstein and Schroedinger one
decade earlier. However in 1980 Treder himself recalled that the potential
$\phi=a/r+cr$, found by him in 1957, was the one used by particle physicists to
account phenomenologically for the spectrum of bound quark systems like mesons.
Exact solutions have later confirmed beyond any doubt that Einstein's unified
field theory does account in a simple way, already in classical form, for the
confinement of pole charges defined by the four-current first availed of by
Treder. In the present paper it is proposed, ad memoriam, a thorough
recollection of the article published by Treder in 1957, showing the way kept
by him to find what would have been later recognized as confinement in
Einstein's unified field theory.


title:
The order completion method for systems of nonlinear PDEs:
  Pseudo-topological perspectives

abstract:
  By setting up appropriate uniform convergence structures, we are able to
reformulate the Order Completion Method of Oberguggenberger and Rosinger in a
setting that more closely resembles the usual topological constructions for
solving PDEs. As an application, we obtain existence and uniqueness results for
the solutions of arbitrary continuous, nonlinear PDEs.


title: A Quiver of Many Runaways

abstract:
  We study the quantum corrections to the moduli space of the quiver gauge
theory corresponding to regular and fractional D3-branes at the dP_1
singularity. We find that besides the known runaway behavior at the lowest step
of the duality cascade, there is a runaway direction along a mesonic branch at
every higher step of the cascade. Moreover, the algebra of the chiral operators
which obtain the large expectation values is such that we reproduce Altmann's
first order deformation of the dP_1 cone.


title: Wedge-Local Quantum Fields and Noncommutative Minkowski Space

abstract:
  Within the setting of a recently proposed model of quantum fields on
noncommutative Minkowski spacetime, the consequences of the consistent
application of the proper, untwisted Poincare group as the symmetry group are
investigated. The emergent model contains an infinite family of fields which
are labelled by different noncommutativity parameters, and related to each
other by Lorentz transformations. The relative localization properties of these
fields are investigated, and it is shown that to each field one can assign a
wedge-shaped localization region of Minkowski space. This assignment is
consistent with the principles of covariance and locality, i.e. fields
localized in spacelike separated wedges commute.
  Regarding the model as a non-local, but wedge-local, quantum field theory on
ordinary (commutative) Minkowski spacetime, it is possible to determine
two-particle S-matrix elements, which turn out to be non-trivial. Some partial
negative results concerning the existence of observables with sharper
localization properties are also obtained.


title: Quantum Resonances and Ratchets in Free-Falling Frames

abstract:
  Quantum resonance (QR) is defined in the free-falling frame of the quantum
kicked particle subjected to gravity. The general QR conditions are derived.
They imply the rationality of the gravity parameter $\eta$, the kicking-period
parameter $\tau /(2\pi)$, and the quasimomentum $\beta$. Exact results are
obtained concerning wave-packet evolution for arbitrary periodic kicking
potentials in the case of integer $\tau /(2\pi)$ (the main QRs). It is shown
that a quantum ratchet generally arises in this case for resonant $\beta$. The
noninertial nature of the free-falling frame affects the ratchet by effectively
changing the kicking potential to one depending on $(\beta ,\eta)$. For a
simple class of initial wave packets, it is explicitly shown that the ratchet
characteristics are determined to a large extent by symmetry properties and by
number-theoretical features of $\eta$.


title: Attractor scenarios and superluminal signals in k-essence cosmology

abstract:
  Cosmological scenarios with k-essence are invoked in order to explain the
observed late-time acceleration of the universe. These scenarios avoid the need
for fine-tuned initial conditions (the "coincidence problem") because of the
attractor-like dynamics of the k-essence field \phi. It was recently shown that
all k-essence scenarios with Lagrangians p=L(X)/\phi^2, necessarily involve an
epoch where perturbations of \phi propagate faster than light (the "no-go
theorem"). We carry out a comprehensive study of attractor-like cosmological
solutions ("trackers") involving a k-essence scalar field \phi and another
matter component. The result of this study is a complete classification of
k-essence Lagrangians that admit asymptotically stable tracking solutions,
among all Lagrangians of the form p=K(\phi)L(X) . Using this classification, we
select the class of models that describe the late-time acceleration and avoid
the coincidence problem through the tracking mechanism. An analogous "no-go
theorem" still holds for this class of models, indicating the existence of a
superluminal epoch. In the context of k-essence cosmology, the superluminal
epoch does not lead to causality violations. We discuss the implications of
superluminal signal propagation for possible causality violations in
Lorentz-invariant field theories.


title:
Dynamical instability and dispersion management of an attractive
  condensate in an optical lattice

abstract:
  We investigate the stability of an attractive Bose-Einstein condensate in a
moving 1D optical lattice in the presence of transverse confinement. By means
of a Bogoliubov linear stability analysis we find that the system is
dynamically unstable for low quasimomenta and becomes stable near the band
edge, in a specular fashion with respect to the repulsive case. For low
interactions the instability occurs via long wavelength excitations that are
not sufficient for spoiling the condensate coherence, producing instead an
oscillating density pattern both in real and momentum space. This behaviour is
illustrated by simulations for the expansion of the condensate in a moving
lattice.


title:
Phase transitions in higher derivative gravity and gauge theory:
  R-charged black holes

abstract:
  This is a continuation of our earlier work where we constructed a
phenomenologically motivated effective action of the boundary gauge theory at
finite temperature and finite gauge coupling on $S^3 \times S^1$. In this
paper, we argue that this effective action qualitatively reproduces the gauge
theory representing various bulk phases of R-charged black hole with
Gauss-Bonnet correction. We analyze the system both in canonical and grand
canonical ensemble.


title:
Kondo quantum dot coupled to ferromagnetic leads: Numerical
  renormalization group study

abstract:
  We systematically study the influence of ferromagnetic leads on the Kondo
resonance in a quantum dot tuned to the local moment regime. We employ Wilson's
numerical renormalization group method, extended to handle leads with a spin
asymmetric density of states, to identify the effects of (i) a finite spin
polarization in the leads (at the Fermi-surface), (ii) a Stoner splitting in
the bands (governed by the band edges) and (iii) an arbitrary shape of the
leads density of states. For a generic lead density of states the quantum dot
favors being occupied by a particular spin-species due to exchange interaction
with ferromagnetic leads leading to a suppression and splitting of the Kondo
resonance. The application of a magnetic field can compensate this asymmetry
restoring the Kondo effect. We study both the gate-voltage dependence (for a
fixed band structure in the leads) and the spin polarization dependence (for
fixed gate voltage) of this compensation field for various types of bands.
Interestingly, we find that the full recovery of the Kondo resonance of a
quantum dot in presence of leads with an energy dependent density of states is
not only possible by an appropriately tuned external magnetic field but also
via an appropriately tuned gate voltage. For flat bands simple formulas for the
splitting of the local level as a function of the spin polarization and gate
voltage are given.


title: Fluctuation Effects on R_pA at High Energy

abstract:
  We discuss a new physical phenomenon for R_pA in the fixed coupling case, the
total gluon shadowing, which arises due to the effect of gluon number
fluctuations.


title: On Matrix Superpotential and Three-Component Normal Modes

abstract:
  We consider the supersymmetric quantum mechanics (SUSY QM) with three-
component normal modes for the Bogomol'nyi-Prasad-Sommerfield (BPS) states. An
explicit form of the SUSY QM matrix superpotential is presented and the
corresponding three-component bosonic zero-mode eigenfunction is investigated.


title: Effective field theory and cold Fermi gases near unitary limit

abstract:
  We study a dynamics of ultracold Fermi-gases near the unitary limit in the
framework of Effective Field Theory. It is shown that, while one can obtain a
reasonable description of the universal proportionality constant both in the
narrow and the broad Feshbach resonance limits, the reguirement of the
reparametrisation invariance leads to appearance of the three body forces
needed to cancel the otherwise arising off-shell uncertainties. The size of the
unsertainties is estimated.


title:
Pseudo-Quantum Criticality in Electron Liquids Exhibited in Expanded
  Alkali Metals

abstract:
  With paying special attention to the divergence in the compressibility
$\kappa$, we study the Coulombic screening in alkali metals to find singular
long-range fluctuations in the electronic polarization originating from this
divergence. As a consequence of this singularity, we predict the decrease of
the equilibration distance between ions against the increase of $r_s$ the
Wigner-Seitz radius of valence electrons, provided that the condition of $2r_c
< r_s < 4r_c$ is satisfied with $r_c$ the ion-core radius. This prediction is
in good quantitative agreement with the recent experiment on liquid Rb.


title:
Local results for flows whose speed or height satisfies a bound of the
  form $\frac c t$

abstract:
  In this paper we prove local results for solutions to the Ricci flow (heat
flow) whose speed (height) is bounded by $\frac c t$ for some time interval $ t
\in (0,T)$. These results are contained in chapter 7 of the author's
habilitation thesis, University of Freiburg, Germany, 2006.


title: Shot noise in the interacting resonance level model

abstract:
  The shot noise power and the Fano factor of a spinless resonant level model
is calculated. The Coulomb interaction which in this model acts between the
lead electron and the impurity is considered in the first order approximation.
The logarithmic divergencies which appeared in the expressions for shot noise
and the transport current are removed by renormalization group analysis. It is
shown that Keldysh technique gives an adequate description of perturbation
theory results. By passing to the bosonized form of the resonance model it is
proven that in the strong interaction limit the tunnelling becomes irrelevant
and decreases.


title:
End-to-End Available Bandwidth Measurement Tools : A Comparative
  Evaluation of Performances

abstract:
  In recent years, there has been a strong interest in measuring the available
bandwidth of network paths. Several methods and techniques have been proposed
and various measurement tools have been developed and evaluated. However, there
have been few comparative studies with regards to the actual performance of
these tools. This paper presents a study of available bandwidth measurement
techniques and undertakes a comparative analysis in terms of accuracy,
intrusiveness and response time of active probing tools. Finally, measurement
errors and the uncertainty of the tools are analysed and overall conclusions
made.


title:
Absolute frequency measurements for hyperfine structure determination of
  the R(26) 62-0 transition at 501.7 nm in molecular iodine

abstract:
  The absolute frequencies of the hyperfine components of the R(26) 62-0
transition in molecular iodine at 501.7 nm are measured for the first time with
an optical clockwork based on a femtosecond laser frequency comb generator. The
set-up is composed of an Ar+ laser locked to a hyperfine component of the R(26)
62-0 transition detected in a continuously pumped low-pressure cell (0.33 Pa).
The detected resonances show a linewidth of 45 kHz (half-width at
half-maximum). The uncertainty of the frequency measurement is estimated to be
250 Hz.


title: Gutzwiller's Trace Formula and Vacuum Pair Production

abstract:
  We propose a new application of the Gutzwiller trace formula formalism, to
give a compact expression for the semiclassical vacuum pair production rate in
quantum electrodynamics, for general inhomogeneous electromagnetic background
fields.


title:
Transmission des forces dans un milieu compos\'e de grains non
  sph\'eriques

abstract:
  We perform a detailed analysis of the contact force network in a dense
confined packing of pentagonal particles simulated by means of the contact
dynamics method. The effect of particle shape is evidenced by comparing the
data from pentagon packing and from a packing with identical characteristics
except for the circular shape of the particles. A counterintuitive finding of
this work is that, under steady shearing, the pentagon packing develops a lower
structural anisotropy than the disk packing. We show that this weakness is
compensated by a higher force anisotropy, leading to enhanced shear strength of
the pentagon packing. We revisit "strong" and "weak" force networks in the
pentagon packing, but our simulation data provide also evidence for a large
class of "very weak" forces carried mainly by vertex-to-edge contacts. The
strong force chains are mostly composed of edge-to-edge contacts with a marked
zig-zag aspect and a decreasing exponential probability distribution as in a
disk packing.


title:
Conserved Matter Superenergy Currents for Orthogonally Transitive
  Abelian G2 Isometry Groups

abstract:
  In a previous paper we showed that the electromagnetic superenergy tensor,
the Chevreton tensor, gives rise to a conserved current when there is a
hypersurface orthogonal Killing vector present. In addition, the current is
proportional to the Killing vector. The aim of this paper is to extend this
result to the case when we have a two-parameter Abelian isometry group that
acts orthogonally transitive on non-null surfaces. It is shown that for
four-dimensional Einstein-Maxwell theory with a source-free electromagnetic
field, the corresponding superenergy currents lie in the orbits of the group
and are conserved. A similar result is also shown to hold for the trace of the
Chevreton tensor and for the Bach tensor, and also in Einstein-Klein-Gordon
theory for the superenergy of the scalar field. This links up well with the
fact that the Bel tensor has these properties and the possibility of
constructing conserved mixed currents between the gravitational field and the
matter fields.


title: Multi-criteria scheduling of pipeline workflows

abstract:
  Mapping workflow applications onto parallel platforms is a challenging
problem, even for simple application patterns such as pipeline graphs. Several
antagonist criteria should be optimized, such as throughput and latency (or a
combination). In this paper, we study the complexity of the bi-criteria mapping
problem for pipeline graphs on communication homogeneous platforms. In
particular, we assess the complexity of the well-known chains-to-chains problem
for different-speed processors, which turns out to be NP-hard. We provide
several efficient polynomial bi-criteria heuristics, and their relative
performance is evaluated through extensive simulations.


title: Quantum toy model for black-hole back-reaction

abstract:
  We propose a simple quantum field theoretical toy model for black hole
evaporation and study the back-reaction of Hawking radiation onto the classical
background. It turns out that the horizon is also ``pushed back'' in this
situation (i.e., the interior region shrinks) but this back-reaction is not
caused by energy conservation but by momentum balance. The effective heat
capacity and the induced entropy variation can have both signs -- depending on
the parameters of the model. PACS: 04.62.+v, 04.70.Dy.


title:
Determination of density and concentration from fluorescent images of a
  gas flow

abstract:
  A fluorescent image analysis procedure to determine the distribution of
species concentration and density in a gas flow is proposed. The fluorescent
emission is due to the excitation of atoms/molecules of a gas that is
intercepted by an electron blade. The intensity of the fluorescent light is
proportional to the local number density of the gas. When the gas flow is a
mixture of different species, this proportionality can be exploited to extract
the contribution associated to the species from the spectral superposition
acquired by a digital camera. This yields a method that simultaneously reveals
species concentrations and mass density of the mixture. The procedure is
applied to two under-expanded sonic jets discharged into a different gas
ambient - Helium into Argon and Argon into Helium - to measure the
concentration and density distribution along the jet axis and across it. A
comparison with experimental and numerical results obtained by other authors
when observing under-expanded jets at different Mach numbers is made with the
density distribution along the axis of the jet. This density distribution
appears to be self-similar.


title: Existence of mesons after deconfinement

abstract:
  We investigate the possibility for a quark-antiquark pair to form a bound
state at temperatures higher than the critical one ($T>T_c$), thus after
deconfinement. Our main goal is to find analytical criteria constraining the
existence of such mesons. Our formalism relies on a Schr\"{o}dinger equation
for which we study the physical consequences of both using the free energy and
the internal energy as potential term, assuming a widely accepted
temperature-dependent Yukawa form for the free energy and a recently proposed
nonperturbative form for the screening mass. We show that using the free energy
only allows for the 1S bottomonium to be bound above $T_c$, with a dissociation
temperature around $1.5\times T_c$. The situation is very different with the
internal energy, where we show that no bound states at all can exist in the
deconfined phase. But, in this last case, quasi-bound states could be present
at higher temperatures because of a positive barrier appearing in the
potential.


title:
A Chandra Study of the Lobe/ISM Interactions Around the Inner Radio
  Lobes of Centaurus A: Constraints on the Temperature Structure and Transport
  Processes

abstract:
  We present results from deeper {\em Chandra} observations of the southwest
radio lobe of Centaurus A, first described by Kraft et al. (2003). We find that
the sharp X-ray surface brightness discontinuity extends around $\sim$75% of
the periphery of the radio lobe, and detect significant temperature jumps in
the brightest regions of this discontinuity nearest to the nucleus. This
demonstrates that this discontinuity is indeed a strong shock which is the
result of an overpressure which has built up in the entire lobe over time.
Additionally, we demonstrate that if the mean free path for ions to transfer
energy and momentum to the electrons behind the shock is as large as the
Spitzer value, the electron and proton temperatures will not have equilibrated
along the SW boundary of the radio lobe where the shock is strongest. Thus the
proton temperature of the shocked gas could be considerably larger than the
observed electron temperature, and the total energy of the outburst
correspondingly larger as well. We investigate this using a simple
one-dimensional shock model for a two-fluid (proton/electron) plasma. We find
that for the thermodynamic parameters of the Cen A shock the electron
temperature rises rapidly from $\sim$0.29 keV (the temperature of the ambient
ISM) to $\sim$3.5 keV at which point heating from the protons is balanced by
adiabatic losses. The proton and electron temperatures do not equilibrate in a
timescale less than the age of the lobe. We note that the measured electron
temperature of similar features in other nearby powerful radio galaxies in poor
environments may considerably underestimate the strength and velocity of the
shock.


title: The Disturbed 17 keV Cluster Associated with the Radio Galaxy 3C 438

abstract:
  We present results from a {\em Chandra} observation of the cluster gas
associated with the FR II radio galaxy 3C 438. This radio galaxy is embedded
within a massive cluster with gas temperature $\sim$17 keV and bolometric
luminosity of 6$\times10^{45}$ ergs s$^{-1}$. It is unclear if this high
temperature represents the gravitational mass of the cluster, or if this is an
already high ($\sim$ 11 keV) temperature cluster that has been heated
transiently. We detect a surface brightness discontinuity in the gas that
extends $\sim$600 kpc through the cluster. The radio galaxy 3C 438 is too small
($\sim$110 kpc across) and too weak to have created this large disturbance in
the gas. The discontinuity must be the result of either an extremely powerful
nuclear outburst or the major merger of two massive clusters. If the observed
features are the result of a nuclear outburst, it must be from an earlier epoch
of unusually energetic nuclear activity. However, the energy required
($\sim10^{63}$ ergs) to move the gas on the observed spatial scales strongly
supports the merger hypothesis. In either scenario, this is one of the most
extreme events in the local Universe.


title: Self-Stabilizing Wavelets and r-Hops Coordination

abstract:
  We introduce a simple tool called the wavelet (or, r-wavelet) scheme.
Wavelets deals with coordination among processes which are at most r hops away
of each other. We present a selfstabilizing solution for this scheme. Our
solution requires no underlying structure and works in arbritrary anonymous
networks, i.e., no process identifier is required. Moreover, our solution works
under any (even unfair) daemon. Next, we use the wavelet scheme to design
self-stabilizing layer clocks. We show that they provide an efficient device in
the design of local coordination problems at distance r, i.e., r-barrier
synchronization and r-local resource allocation (LRA) such as r-local mutual
exclusion (LME), r-group mutual exclusion (GME), and r-Reader/Writers. Some
solutions to the r-LRA problem (e.g., r-LME) also provide transformers to
transform algorithms written assuming any r-central daemon into algorithms
working with any distributed daemon.


title: Heavy-Quarkonia in the Star Experiment

abstract:
  Heavy Quarkonium states modifications in relativistic heavy ion collisions
have been of great interest since the proposal by Matsui and Satz of J/psi
suppression as a signature of Quark-Gluon Plasma (QGP) formation. Recent
studies suggest that the excited states chi_c, psi(2S) and Upsilon(3S) melt
sequentially[1,2] and the amount of observed suppression depends on the state
and medium conditions. Therefore, this suppression pattern may be used as a
probe of the medium temperature. In this work we present preliminary results on
the charmonium and bottomnium measurements performed by the STAR experiment at
RHIC for p+p and Cu+Cu collisions at sqrt(s_{NN})=200GeV


title: The Role of Gauge Invariance in Single-Spin Asymmetries

abstract:
  We argue that through the Wilson lines, gauge invariance has as an effect
that the hard functions in weighted spin-asymmetries in hadronic scattering
processes are given by gluonic pole cross sections, rather than the usual
partonic cross sections.


title: Stochastic control problems for systems driven by normal martingales

abstract:
  In this paper we study a class of stochastic control problems in which the
control of the jump size is essential. Such a model is a generalized version
for various applied problems ranging from optimal reinsurance selections for
general insurance models to queueing theory. The main novel point of such a
control problem is that by changing the jump size of the system, one
essentially changes the type of the driving martingale. Such a feature does not
seem to have been investigated in any existing stochastic control literature.
We shall first provide a rigorous theoretical foundation for the control
problem by establishing an existence result for the multidimensional structure
equation on a Wiener--Poisson space, given an arbitrary bounded jump size
control process; and by providing an auxiliary counterexample showing the
nonuniqueness for such solutions. Based on these theoretical results, we then
formulate the control problem and prove the Bellman principle, and derive the
corresponding Hamilton--Jacobi--Bellman (HJB) equation, which in this case is a
mixed second-order partial differential/difference equation. Finally, we prove
a uniqueness result for the viscosity solution of such an HJB equation.


title: Induction and computation of Bass Nil Groups for finite groups

abstract:
  Let G be a finite group. We show that the Bass Nil-groups $NK_n(RG)$, $n \in
Z$, are generated from the p-subgroups of G by induction maps, certain twisting
maps depending on elements in the centralizers of the p-subgroups, and the
Verschiebung homomorphisms. As a consequence, the groups $NK_n(RG)$ are
generated by induction from elementary subgroups. For $NK_0(ZG)$ we get an
improved estimate of the torsion exponent.


title: Extensivity and Relativistic Thermodynamics

abstract:
  The mathematical properties associated with the widely accepted concept of
the extensivity of many of the common thermodynamic variables are examined and
some of their consequences considered. The possible conflict between some of
these and currently accepted results of special relativistic thermodynamics is
highlighted. Although several questions are raised, answers are not advanced as
this seems an area demanding calm, widespread reflection which could
conceivably lead to radical revision of part, or parts, of theoretical physics.


title: Nonergodicity and Central Limit Behavior for Long-range Hamiltonians

abstract:
  We present a molecular dynamics test of the Central Limit Theorem (CLT) in a
paradigmatic long-range-interacting many-body classical Hamiltonian system, the
HMF model. We calculate sums of velocities at equidistant times along
deterministic trajectories for different sizes and energy densities. We show
that, when the system is in a chaotic regime (specifically, at thermal
equilibrium), ergodicity is essentially verified, and the Pdfs of the sums
appear to be Gaussians, consistently with the standard CLT. When the system is,
instead, only weakly chaotic (specifically, along longstanding metastable
Quasi-Stationary States), nonergodicity (i.e., discrepant ensemble and time
averages) is observed, and robust $q$-Gaussian attractors emerge, consistently
with recently proved generalizations of the CLT.

categories: cond-mat.stat-mech astro-ph nucl-th physics.data-an


title:
A 100ks XMM-Newton view of the Seyfert 1.8 ESO113-G010. I. Discovery of
  large X-ray variability and study of the FeKalpha line complex

abstract:
  (Abridged) We present here a long (100ks) XMM-Newton follow-up of the Seyfert
1.8 galaxy ESO113-G010 performed in November 2005, in order to study over a
longer time-scale its main X-ray properties. The source was found in a
higher/softer time-averaged flux state, and timing analysis of this source
reveals strong, rapid variability. The Power Spectral Density (PSD) analysis
indicates (at 95% c.l.) a break at 3.7 x 10^-4 Hz. This cut-off frequency is
comparable to those measured in some other rapidly-variable Seyferts, such as
MCG-6-30-15 and NGC4051. From the mass-luminosity-time-scale, we infer that
M_BH ranges from 4 x 10^6 - 10^7 M_odot and the source is accreting at or close
to the Eddington rate (or even higher). The existing data cannot distinguish
between spectral pivoting of the continuum and a two-component origin for the
spectral softening, primarily because the data do not span a broad enough flux
range. In the case of the two-component model, the fractional offsets measured
in the flux-flux plots increase significantly toward higher energies (similar
to what is observed in MCG-6-30-15) as expected if there exists a constant
reflection component. Contrary to May 2001, no significant highly redshifted
emission line is observed (which might be related to the source flux level),
while two narrow emission lines at about 6.5keV and 7keV are observed. The S/N
is not high enough to establish if the lines are variable or constant. As
already suggested by the 2001 observation, no significant constant narrow
6.4keV FeK line (EW~32eV) is observed, hence excluding any dominant emission
from distant cold matter such as a torus in this Seyfert type 1.8 galaxy.


title:
Role of the Delta(1232) in pion-deuteron scattering at threshold within
  chiral effective field theory

abstract:
  We investigate the role of the delta isobar in the reaction $\pi d\to \pi d$
at threshold in chiral effective field theory. We discuss the corresponding
power counting and argue that this calculation completes the evaluation of
diagrams up to the order (m_pi/M_N)^(3/2), with m_pi (M_N) for the pion
(nucleon) mass. The net effect of all delta contributions at this order to the
pion-deuteron scattering length is (2.4 +/- 0.4)x 10^(-3) m_pi^{-1}.


title:
Cool Customers in the Stellar Graveyard IV: Spitzer Search for Mid-IR
  excesses Around Five DAs

abstract:
  Hydrogen atmosphere white dwarfs with metal lines, so-called DAZs, require
external accretion of material to explain the presence of weak metal line
absorption in their photospheres. The source of this material is currently
unknown, but could come from the interstellar medium, unseen companions, or
relic planetesimals from asteroid belt or Kuiper belt analogues. Accurate
mid-infrared photometry of these white dwarfs provide additional information to
solve the mystery of this accretion and to look for evidence of planetary
systems that have survived post main sequence evolution. We present {\em
Spitzer} IRAC photometry accurate to $\sim$3% for four DAZs and one DA with
circumstellar absorption lines in the UV. We search for excesses due to unseen
companions or circumstellar dust disks. We use {\em Hubble Space Telescope}
NICMOS imaging of these white dwarfs to gauge the level of background
contamination to our targets as well as rule out common proper motion
companions to WD 1620-391. All of our targets show no excesses due to
companions $>$20 M$_{J}$, ruling out all but very low mass companions to these
white dwarfs at all separations. No excesses due to circumstellar disks are
observed, and we place limits on what types of disks may still be present.


title: Plausible "faster-than-light" displacements in a two-sheeted spacetime

abstract:
  In this paper, we explore the implications of a two-point discretization of
an extra-dimension in a five-dimensional quantum setup. We adopt a pragmatic
attitude by considering the dynamics of spin-half particles through the
simplest possible extension of the existing Dirac and Pauli equations. It is
shown that the benefit of this approach is to predict new physical phenomena
while maintaining the number of constitutive hypothesis at minimum. As the most
striking feature of the model, we demonstrate the possibility of fermionic
matter oscillations between the two four-dimensional sections and hyper-fast
displacements in case of asymmetric warping (without conflicting special
relativity). This result, similar to previous reported ones in brane-world
theories, is completely original as it is derived by using quantum mechanics
only without recourse to general relativity and bulk geodesics calculation. The
model allows causal contact between normally disconnected regions. If it proves
to be physically founded, its practical aspects could have deep implications
for the search of extra-dimensions.


title: Two Pion Production from Nuclei

abstract:
  Differences in the photoproduction of mesons on the free proton and on nuclei
are expected to reveal changes in the properties of hadrons. Double pion
photoproduction from nuclei has been used to investigate the in medium
modification of meson-meson interactions with the TAPS photon spectrometer at
MAMI-B. Recent developments are reported.
  Hadron-hadron interactions and meson production and decays involving light
nuclei are also studied in hadron induced experiments. In particular, the
physics program of the new WASA-at-COSY facility includes double pion
production from light nuclei. Here, the efforts focus on the ABC effect, the
puzzling low-mass enhancement in the pi-pi invariant mass spectrum, first
observed in inclusive measurements of two-pion production in nuclear
collisions.


title: Alkali Halide Surfaces Near Melting: Wetting and Nanofriction Properties

abstract:
  Alkali halide (100) crystal surfaces are poorly wetted by their own melt at
the triple point. We carried out simulations for NaCl(100) within the well
tested BMHFT model potential. Calculations of the solid-vapor, solid-liquid and
liquid-vapor free energies showed that solid NaCl(100) is a non-melting
surface, and explain its bad wetting in detail.
  The extreme stability of NaCl(100) is ideal for a study of the nanofriction
in the high temperature regime, close to and even above the bulk melting
temperature (T_M). Our simulations reveal in this regime two distinct and
opposite phenomena for plowing and for grazing friction. We found a frictional
drop close to T_M for deep ploughing and wear, but on the contrary a frictional
rise for grazing, wearless sliding. For both phenomena we obtain a fresh
microscopic understanding, relating the former to ``skating'' through a local
liquid cloud, the latter to softening of the free substrate surface. It is
argued that both phenomena, to be pursued experimentally, should be much more
general than the specific NaCl surface case. Most metals in particular
possessing one or more close packed non-melting surface, such as Pb, Al or
Au(111), should behave quite similarly.


title:
Theoretical analysis of the atmospheres of CP stars. Effects of the
  individual abundance patterns

abstract:
  Context. See abstract in the paper.
  Aims. See abstract in the paper.
  Methods. See abstract in the paper.
  Results. We present a homogeneous study of model atmosphere temperature
structure, energy distribution, photometric indices in the uvbybeta and Delta_a
systems, hydrogen line profiles, and the abundance determination procedure as
it applies to CP stars. In particular, we found that Si, Cr and Fe are the main
elements to influence model atmospheres of CP stars, and thus to be considered
in order to assess the adequacy of model atmospheres with scaled solar
abundances in application to CP stars. We provide a theoretical explanation of
the robust property of the Delta_a photometric system to recognize CP stars
with peculiar Fe content. Also, the results of our numerical tests using model
atmospheres with one or several elements overabundant (Si and Fe by +1 dex, Cr
by +2 dex) suggest that the uncertainty of abundance analysis in the
atmospheres of CP stars using models with scaled abundances is less than
plus/minus 0.25 dex. If the same homogeneous models are used for the abundance
stratification analysis then we find that the uncertainty of the value of the
vertical abundance gradient is within an 0.4 dex error bar.
  Conclusions. Model atmospheres with individual abundance patterns should be
used in order to match the actual anomalies of CP stars and minimize analysis
errors.


title:
Dynamics of a qubit coupled to a broadened harmonic mode at finite
  detuning

abstract:
  We study the dynamics of a symmetric two-level system strongly coupled to a
broadened harmonic mode. Upon mapping the problem onto a spin-boson model with
peaked spectral density, we show how analytic solutions can be obtained, at
arbitrary detuning and finite temperatures, in the case of large Q-factors of
the oscillator. In general {\em two} or more oscillation frequencies of the
two-level particle are observed as a consequence of the entanglement with the
oscillator. Our approximated analytical solution well agrees with numerical
predictions obtained within the non-interacting blip approximation.


title: On the Pauli principle violation in QFT

abstract:
  We propose a new mechanism for a ''small" violation of Pauli Principle in the
framework of Quantum Field Theory. Instead of modification of algebra -
commutation relations for fields - we introduce spontaneous violation of Pauli
Principle which is proportional to the vacuum fermionic condensate.


title: Small effects of low-energy quantum gravity

abstract:
  Small effects of quantum gravity on the scale $\sim 10^{-3} eV$ and their
cosmological consequences are discussed and compared with observations of
supernovae 1a, gamma-ray bursts and galaxies.


title:
How much information about a dynamical system do its recurrences
  contain?

abstract:
  We show that, under suitable assumptions, Poincare recurrences of a dynamical
system determine its topology in phase space. Therefore, dynamical systems with
the same recurrences are topologically equivalent.


title:
Testing the viability of the interacting holographic dark energy model
  by using combined observational constraints

abstract:
  Using the data coming from the new 182 Gold type Ia supernova samples, the
shift parameter of the Cosmic Microwave Background given by the three-year
Wilkinson Microwave Anisotropy Probe observations, and the baryon acoustic
oscillation measurement from the Sloan Digital Sky Survey, $H(z)$ and lookback
time measurements, we have performed a statistical joint analysis of the
interacting holographic dark energy model. Consistent parameter estimations
show us that the interacting holographic dark energy model is a viable
candidate to explain the observed acceleration of our universe.


title:
Caustics due to Negative Refractive Index in Circular Graphene p-n
  Junctions

abstract:
  We show that the wavefunctions form caustics in circular graphene p-n
junctions which in the framework of geometrical optics can be interpreted with
negative refractive index.


title: Encounter-based worms: Analysis and Defense

abstract:
  Encounter-based network is a frequently-disconnected wireless ad-hoc network
requiring immediate neighbors to store and forward aggregated data for
information disseminations. Using traditional approaches such as gateways or
firewalls for deterring worm propagation in encounter-based networks is
inappropriate. We propose the worm interaction approach that relies upon
automated beneficial worm generation aiming to alleviate problems of worm
propagations in such networks. To understand the dynamic of worm interactions
and its performance, we mathematically model worm interactions based on major
worm interaction factors including worm interaction types, network
characteristics, and node characteristics using ordinary differential equations
and analyze their effects on our proposed metrics. We validate our proposed
model using extensive synthetic and trace-driven simulations. We find that, all
worm interaction factors significantly affect the pattern of worm propagations.
For example, immunization linearly decreases the infection of susceptible nodes
while on-off behavior only impacts the duration of infection. Using realistic
mobile network measurements, we find that encounters are bursty, multi-group
and non-uniform. The trends from the trace-driven simulations are consistent
with the model, in general. Immunization and timely deployment seem to be the
most effective to counter the worm attacks in such scenarios while cooperation
may help in a specific case. These findings provide insight that we hope would
aid to develop counter-worm protocols in future encounter-based networks.


title:
The Thermal Structure of the Circumstellar Disk Surrounding the
  Classical Be Star gamma Cassiopeia

abstract:
  We have computed radiative equilibrium models for the gas in the
circumstellar envelope surrounding the hot, classical Be star $\gamma
$Cassiopeia. This calculation is performed using a code that incorporates a
number of improvements over previous treatments of the disk's thermal structure
by \citet{mil98} and \citet{jon04}; most importantly, heating and cooling rates
are computed with atomic models for H, He, CNO, Mg, Si, Ca, & Fe and their
relevant ions. Thus, for the first time, the thermal structure of a Be disk is
computed for a gas with a solar chemical composition as opposed to assuming a
pure hydrogen envelope. We compare the predicted average disk temperature, the
total energy loss in H$\alpha$, and the near-IR excess with observations and
find that all can be accounted for by a disk that is in vertical hydrostatic
equilibrium with a density in the equatorial plane of $\rho(R)\approx 3$ to
$5\cdot 10^{-11} (R/R_*)^{-2.5} \rm g cm^{-3}$. We also discuss the changes in
the disk's thermal structure that result from the additional heating and
cooling processes available to a gas with a solar chemical composition over
those available to a pure hydrogen plasma.


title: Ha Emission from the Magellanic Bridge

abstract:
  We present here a preliminary report and commentary of recently processed
observations of Ha emission towards the Magellanic Bridge. These data have been
analysed in an attempt to quantify the extent to which the stellar population
is capable of reshaping the local ISM. We find that the Ha emission regions are
small, weak and sparsely distributed, consistent with a relatively quiescent
and inactive ISM where radiative and collisional ionisation is inefficient and
sporadic. This suggests that energetic processes at the small scale (i.e. ~tens
of pc) do not dominate the energy balance within the ISM of the Bridge, which
therefore hosts a pristine turbulent structure, otherwise inaccessible within
our own Galaxy. We find Ha emission that is well correlated with detected
12CO(1-0) line emission (a proxy for molecular hydrogen), as well as other
easily identified ring-like HI features.