title:
Localized eigenmodes of the overlap operator and their impact on the
  eigenvalue distribution

abstract:
  In a system where chiral symmetry is spontaneously broken, the low energy
eigenmodes of the continuum Dirac operator are extended. On the lattice, due to
discretization effects, the Dirac operator can have localized eigenmodes that
affect physical quantities sensitive to chiral symmetry. While the infrared
eigenmodes of the Wilson Dirac operator are usually extended even on coarse
lattices, the chiral overlap operator has many localized eigenmodes in the
physical region, especially in mixed action simulations. Depending on their
density, these modes can introduce strong lattice artifacts. The effect can be
controlled by changing the parameters of the overlap operator, in particular
the clover improvement term and the center of the overlap projection.


title: Cosmological tests of generalized RS brane-worlds with Weyl fluid

abstract:
  A class of generalized Randall-Sundrum type II (RS) brane-world models with
Weyl fluid are confronted with the Gold supernovae data set and BBN
constraints. We consider three models with different evolutionary history of
the Weyl fluid, characterized by the parameter $\alpha$. For $\alpha=0$ the
Weyl curvature of the bulk appears as dark radiation on the brane, while for
$\alpha =2$ and 3 the brane radiates, leaving a Weyl fluid on the brane with
energy density decreasing slower than that of (dark) matter. In each case the
contribution $\Omega_d$ of the Weyl fluid represents but a few percent of the
energy content of the Universe. All models fit reasonably well the Gold2006
data. The best fit model for $\alpha =0$ is for $\Omega_d=0.04$. In order to
obey BBN constraints in this model however, the brane had to radiate at earlier
times.


title: Two physical characteristics of numerical apparent horizons

abstract:
  This article translates some recent results on quasilocal horizons into the
language of $(3+1)$ general relativity so as to make them more useful to
numerical relativists. In particular quantities are described which
characterize how quickly an apparent horizon is evolving and how close it is to
either equilibrium or extremality.


title:
The Algebraic Complexity of Maximum Likelihood Estimation for Bivariate
  Missing Data

abstract:
  We study the problem of maximum likelihood estimation for general patterns of
bivariate missing data for normal and multinomial random variables, under the
assumption that the data is missing at random (MAR). For normal data, the score
equations have nine complex solutions, at least one of which is real and
statistically significant. Our computations suggest that the number of real
solutions is related to whether or not the MAR assumption is satisfied. In the
multinomial case, all solutions to the score equations are real and the number
of real solutions grows exponentially in the number of states of the underlying
random variables, though there is always precisely one statistically
significant local maxima.


title:
New Curved Spacetime Dirac Equations - On the Anomalous Gyromagnetic
  Ratio

abstract:
  I propose three new curved spacetime versions of the Dirac Equation. These
equations have been developed mainly to try and account in a natural way for
the observed anomalous gyromagnetic ratio of Fermions. The derived equations
suggest that particles including the Electron which is thought to be a point
particle do have a finite spatial size which is the reason for the observed
anomalous gyromagnetic ratio. A serendipitous result of the theory, is that,
two of the equation exhibits an asymmetry in their positive and negative energy
solutions the first suggestion of which is clear that a solution to the problem
as to why the Electron and Muon - despite their acute similarities - exhibit an
asymmetry in their mass is possible. The Mourn is often thought as an Electron
in a higher energy state. Another of the consequences of three equations
emanating from the asymmetric serendipity of the energy solutions of two of
these equations, is that, an explanation as to why Leptons exhibit a three
stage mass hierarchy is possible.


title: On the reliability of linear band structure methods

abstract:
  We discuss an efficiency of various band structure algorithms in determining
the Fermi surface (FS) of the paramagnetic ErGa3. The linear muffin-tin orbital
(LMTO) in the atomic sphere approximation (ASA) method and three full potential
(FP) codes: FP-LMTO, FP linear augmented plane wave (FLAPW), and FP local
orbitals (FPLO) methods are employed. Results are compared with
electron-positron (e-p) momentum densities reconstructed from two dimensional
angular correlation of annihilation radiation (2D ACAR). Unexpectedly, none of
used modern FP codes is able to give satisfying description of the experimental
data that are in perfect agreement with LMTO-ASA results. We suspect that it
can be connected with a different choice of the linearization energy.


title: Half-metallic graphene nanodots

abstract:
  A comprehensive first-principles theoretical study of the electronic
properties and half-metallic nature of finite rectangular graphene nanoribbons
is presented. We identify the bisanthrene isomer of the C28H14 molecule to be
the smallest polycyclic aromatic hydrocarbon to present a spin polarized ground
state. Even at this quantum dot level, the spins are predicted to be aligned
antiferromagnetically at the two zigzag edges of the molecule. As a rule of
thumb, we find that zigzag edges that are at least three consecutive units
long, will present spin polarization if the width of the system is 1 nm or
wider. Room temperature detectability of the magnetic ordering is predicted for
molecules with zigzag edges 1 nm and longer. For the longer systems studied,
spin wave structures appear in some high spin multiplicity states. Energy gap
oscillations with the length of the zigzag edge are observed. The amplitude of
these oscillations is found to be smaller than that predicted for infinite
ribbons. The half-metallic nature of the ribbons under an external in-plane
electric field is found to be preserved even for finite and extremely short
systems.


title: Dimension Six Corrections to the Vector Sector of AdS/QCD Model

abstract:
  We study the effects of dimension six terms on the predictions of the
holographic model for the vector meson form factors and determine the
corrections to the electric radius, the magnetic and the quadrupole moments of
the rho-meson. We show that the only dimension six terms which contribute
nontrivially to the vector meson form factors are X^2F^2 and F^3. It appears
that the effect from the former term is equivalent to the metric deformation
and can change only masses, decay constants and charge radii of vector mesons,
leaving the magnetic and the quadrupole moments intact. The latter term gives
different contributions to the three form factors of the vector meson and
changes the values of the magnetic and the quadrupole moments. The results
suggest that the addition of the higher dimension terms improves the
holographic model.


title:
Coherent network analysis for triggered gravitational wave burst
  searches

abstract:
  Searches for gravitational wave bursts that are triggered by the observation
of astronomical events require a different mode of analysis than all-sky, blind
searches. For one, much more prior information is usually available in a
triggered search which can and should be used in the analysis. Second, since
the data volume is usually small in a triggered search, it is also possible to
use computationally more expensive algorithms for tasks such as data
pre-processing that can consume significant computing resources in a high
data-volume un-triggered search. From the statistical point of view, the
reduction in the parameter space search volume leads to higher sensitivity than
an un-triggered search. We describe here a data analysis pipeline for triggered
searches, called {\tt RIDGE}, and present preliminary results for simulated
noise and signals.


title:
Ettore Majorana's Inaugural Lecture on Theoretical Physics (Naples,
  Italy; Jan.13, 1938)

abstract:
  Ettore Majorana was a member of Enrico Fermi's research group in Rome, Italy.
Fermi did regard Majorana as much brihter than himself as far as theoretical
physics was concerned (more information can be found particularly in the
arXives' e-print physics/9810023, in Italian, and refs therein, and also in the
recent multilanguage arXiv:0708.2855v1 [physics.hist-ph]). In 1937 Majorana
partecipated in the national Italian competition, for a chair in theoretical
phyics, requested by Emilio Segre' at that time at Palermo University: Other
competitors being GC.Wick, G.Racah, and G.Gentile jr. After a proposal of the
judging Commette, chaired by E.Fermi, Majorana got a full-professorship at
Naples University, for exceptional scientific merits, outside the competition
normal procedures. In this e-print we make known the notes prepared by Majorana
for his Inaugural Lecture (and discovered long ago, in 1973, by one of the
present editors (ER)),together with some comments of ours: everything being
both in English (first article) and in Italian (second article, with a short
Bibliography at its end). The present articles have been prepared on the
occasion of the Centenary (2006) of Majorana's birth. The preliminary notes for
his Inaugural Lecture reveal Majorana's interest not only for scientific
research, but also for the best didactical methods to be followed in order to
teach classical and quantum physics in the most effective way (while his
approach to Special Relativity is known to us from his lecture notes, published
elesewhere). P.S.: Il Riassunto in Italiano appare all'inizio della versione
italiana.


title:
Matters of Gravity, The Newsletter of the Topical Group in Gravitation
  of the American Physical Society, Volume 30, Fall 2007

abstract:
  GGR News:
  -we hear that..., by David Garfinkle
  -News from the GRG Society, by Abhay Ashtekar
  -LIGO/GEO/Virgo work together, by Peter Saulson
  -GWIC Ten Years on, by Stan Whitcomb
  Research Briefs:
  -Quasi-local energy, by Bjoern S. Schmekel
  -The current status of cosmic strings, by Patrick Peter
  -Gravitational waves from `mountains' on neutron stars, by Ian Jones
  Conference reports:
  -GR18/Amaldi 2007 in Sydney, by Jorge Pullin
  -Synergy in Singularities? by Don Marolf
  -Gravitation and the Cosmos, by Derek Fox and Parampreet Singh
  -NumRel meets PN, by Buonanno et al
  -SaulFest, by Greg Cook
  -3rd Gulf Coast Gravity Conference, by Vitor Cardoso


title: On the Frobenius functor and colon ideals

abstract:
  In this paper we study the commutativity of the Frobenius functor and the
colon operation of two ideals for Noetherian rings of positive characteristic
$p$. New characterizations of regular rings and local UFDs are given.


title:
An m sin i = 24 Earth Mass Planetary Companion To The Nearby M Dwarf GJ
  176

abstract:
  We report the detection of a planetary companion with a minimum mass of m sin
i = 0.0771 M_Jup = 24.5 M_Earth to the nearby (d = 9.4 pc) M2.5V star GJ 176.
The star was observed as part of our M dwarf planet search at the Hobby-Eberly
Telescope (HET). The detection is based on 5 years of high-precision
differential radial velocity (RV) measurements using the
High-Resolution-Spectrograph (HRS). The orbital period of the planet is 10.24
d. GJ 176 thus joins the small (but increasing) sample of M dwarfs hosting
short-periodic planets with minimum masses in the Neptune-mass range. Low mass
planets could be relatively common around M dwarfs and the current detections
might represent the tip of a rocky planet population.


title: The Survival Rate of Ejected Terrestrial Planets with Moons

abstract:
  During planet formation, a gas giant will interact with smaller protoplanets
that stray within its sphere of gravitational influence. We investigate the
outcome of interactions between gas giants and terrestrial-sized protoplanets
with lunar-sized companions. An interaction between a giant planet and a
protoplanet binary may have one of several consequences, including the delivery
of volatiles to the inner system, the capture of retrograde moons by the giant
planet, and the ejection of one or both of the protoplanets. We show that an
interesting fraction of terrestrial-sized planets with lunar sized companions
will likely be ejected into interstellar space with the companion bound to the
planet. The companion provides an additional source of heating for the planet
from tidal dissipation of orbital and spin angular momentum. This heat flux
typically is larger than the current radiogenic heating of the Earth for up to
the first few hundred million years of evolution. In combination with an
atmosphere of sufficient thickness and composition, the heating can provide the
conditions necesary for liquid water to persist on the surface of the
terrestrial mass planet, making it a potential site for life. We also determine
the possibility for directly detecting such systems through all-sky infrared
surveys or microlensing surveys. Microlensing surveys in particular will
directly measure the frequency of this phenomenon.


title: The Warm Spitzer Mission: Prospects for Studies of the Distant Universe

abstract:
  IRAC excels at detecting distant objects. Due to a combination of the shapes
of the spectral energy distributions of galaxies and the low background
achieved from space, IRAC reaches greater depth in comparable exposure time at
3.6 and 4.5 micron than any ground- or space-based facility currently can at
2.2 micron. Furthermore, the longer wavelengths probed by IRAC enable studies
of the rest-frame optical and near-infrared light of galaxies and AGN to much
higher redshift than is possible from the ground. This white paper explores the
merits of different survey strategies for studying the distant universe during
the warm mission. A three-tiered approach serves a wide range of science goals
and uses the spacecraft effectively: 1) an ultra-deep survey of ~0.04 square
degrees to a depth of ~250 hrs (in conjunction with an HST/WFC3 program), to
study the Universe at 7<z<14; 2) a survey of ~2 square degrees to the GOODS
depth of 20 hrs, to identify luminous galaxies at z>6 and characterize the
relation between the build-up of dark matter halos and their constituent
galaxies at 2<z<6, and 3) a 500 square degree survey to the SWIRE depth of 120
s, to systematically study large scale structure at 1<z<2 and characterize high
redshift AGN. One or more of these programs could conceivably be implemented by
the SSC, following the example of the Hubble Deep Field campaigns. As
priorities in this field continuously shift it is also crucial that a fraction
of the exposure time remains unassigned, thus enabling science that will
reflect the frontiers of 2010 and beyond rather than those of 2007.


title: A search for CO+ in planetary nebulae

abstract:
  We have carried out a systematic search for the molecular ion CO+ in a sample
of 8 protoplanetary and planetary nebulae in order to determine the origin of
the unexpectedly strong HCO+ emission previously detected in these sources. An
understanding of the HCO+ chemistry may provide direct clues to the physical
and chemical evolution of planetary nebulae. We find that the integrated
intensity of the CO+ line may be correlated with that of HCO+, suggesting that
the reaction of CO+ with molecular hydrogen may be an important formation route
for HCO+ in these planetary nebulae.


title:
QUBIT4MATLAB V3.0: A program package for quantum information science and
  quantum optics for MATLAB

abstract:
  A program package for MATLAB is introduced that helps calculations in quantum
information science and quantum optics. It has commands for the following
operations: (i) Reordering the qudits of a quantum register, computing the
reduced state of a quantum register. (ii) Defining important quantum states
easily. (iii) Formatted input and output for quantum states and operators. (iv)
Constructing operators acting on given qudits of a quantum register and
constructing spin chain Hamiltonians. (v) Partial transposition, matrix
realignment and other operations related to the detection of quantum
entanglement. (vi) Generating random state vectors, random density matrices and
random unitaries.


title:
The nearby young visual binary HIP 115147 and its common proper motion
  companion LSPM J2322+7847

abstract:
  We report a late M-type, common proper motion companion to a nearby young
visual binary HIP 115147 (V368 Cep), separated by 963 arcseconds from the
primary K0 dwarf. This optically dim star has been identified as a candidate
high proper motion, nearby dwarf LSPM J2322+7847 by L{\'e}pine in 2005. The
wide companion is one of the latest post-T Tauri low mass stars found within 20
pc. We obtain a trigonometric parallax of $51.6\pm0.8$ mas, in good agreement
with the Hipparcos parallax of the primary star ($50.7\pm0.6$ mas). Our $BVRI$
photometric data and near-infrared data from 2MASS are consistent with LSPM
J2322+7847 being brighter by 1 magnitude in $K_s$ than field M dwarfs at
$V-K_s=6.66$, which indicates its pre-main sequence status. We conclude that
the most likely age of the primary HIP 115147 and its 11-arcsecond companion
HIP 115147B is 20-50 Myr. The primary appears to be older than its close analog
PZ Tel (age 12-20 Myr) and members of the TWA association (7 Myr).


title: Cosmic Strings from Supersymmetric Flat Directions

abstract:
  Flat directions are a generic feature of the scalar potential in
supersymmetric gauge field theories. They can arise, for example, from D-terms
associated with an extra abelian gauge symmetry. Even when supersymmetry is
broken softly, there often remain directions in the scalar field space along
which the potential is almost flat. Upon breaking a gauge symmetry along one of
these almost flat directions, cosmic strings may form. Relative to the standard
cosmic string picture based on the abelian Higgs model, these flat-direction
cosmic strings have the extreme Type-I properties of a thin gauge core
surrounded by a much wider scalar field profile. We perform a comprehensive
study of the microscopic, macroscopic, and observational characteristics of
this class of strings. We find many differences from the standard string
scenario, including stable higher winding mode strings, the dynamical formation
of higher mode strings from lower ones, and a resultant multi-tension scaling
string network in the early universe. These strings are only moderately
constrained by current observations, and their gravitational wave signatures
may be detectable at future gravity wave detectors. Furthermore, there is the
interesting but speculative prospect that the decays of cosmic string loops in
the early universe could be a source of ultra-high energy cosmic rays or
non-thermal dark matter. We also compare the observational signatures of
flat-direction cosmic strings with those of ordinary cosmic strings as well as
(p,q) cosmic strings motivated by superstring theory.


title:
Three-Dimensional Simulations of Inflows Irradiated by a Precessing
  Accretion Disk in Active Galactic Nuclei: Formation of Outflows

abstract:
  We present three-dimensional (3-D) hydrodynamical simulations of gas flows in
the vicinity of an active galactic nucleus (AGN) powered by a precessing
accretion disk. We consider the effects of the radiation force from such a disk
on its environment on a relatively large scale (up to ~10 pc. We implicitly
include the precessing disk by forcing the disk radiation field to precess
around a symmetry axis with a given period ($P$) and a tilt angle ($\Theta$).
We study time evolution of the flows irradiated by the disk, and investigate
basic dependencies of the flow morphology, mass flux, angular momentum on
different combinations of $\Theta$ and $P$. We find the gas flow settles into a
configuration with two components, (1) an equatorial inflow and (2) a bipolar
inflow/outflow with the outflow leaving the system along the poles (the
directions of disk normals). However, the flow does not always reach a steady
state. We find that the maximum outflow velocity and the kinetic outflow power
at the outer boundary can be reduced significantly with increasing $\Theta$. We
also find that of the mass inflow rate across the inner boundary does not
change significantly with increasing $\Theta$. (Abbreviated)


title: Measuring AGN Feedback with the Sunyaev-Zel'dovich Effect

abstract:
  One of the most important and poorly-understood issues in structure formation
is the role of outflows driven by active galactic nuclei (AGN). Using
large-scale cosmological simulations, we compute the impact of such outflows on
the small-scale distribution of the cosmic microwave background (CMB). Like
gravitationally-heated structures, AGN outflows induce CMB distortions both
through thermal motions and peculiar velocities, by processes known as the
thermal and kinetic Sunyaev-Zel'dovich (SZ) effects, respectively. For AGN
outflows the thermal SZ effect is dominant, doubling the angular power spectrum
on arcminute scales. But the most distinct imprint of AGN feedback is a
substantial increase in the thermal SZ distortions around elliptical galaxies,
post-starburst ellipticals, and quasars, which is linearly proportional to the
outflow energy. While point source subtraction is difficult for quasars, we
show that by appropriately stacking microwave measurements around early-type
galaxies, the new generation of small-scale microwave telescopes will be able
to directly measure AGN feedback at the level important for current theoretical
models.


title: Intrinsic Structure and Kinematics of the Sub-Parsec Scale Jet of M87

abstract:
  We report new results from a sub-parsec scale study of the inner jet in M87
performed at 15 GHz with the Very Long Baseline Array. We have detected a limb
brightened structure of the jet along with a faint 3 mas long counter-feature
which we also find to be limb brightened. Typical speeds of separate jet
features are measured to be less than 0.05 speed of light, despite the highly
asymmetric jet structure and the implications of the canonical relativistic
beaming scenario. The observed intrinsic jet structure can be described in
terms of a two stream spine-sheath velocity gradient across the jet according
to theoretical predications based on the recently discovered strong and
variable TeV emission from M87. The jet to counter-jet flux density ratio is
measured to be greater than 200. The observed intrinsic jet structure is
broadly consistent with theoretical predictions of a spine-sheath velocity
gradient suggested by recently discovered TeV emission from M87.


title: Polaron tunneling dynamics in the DNA molecule

abstract:
  The formation of polaron and its migration in a DNA chain are studied within
a semiclassical Peyrard-Biship-Holstein polaron model. Comparing the energetics
of the polaron system found from the quantum chemical and semiclassical
calculations, we extract the charge-phonon coupling constant for poly DNA
sequences. The coupling constant is found to be larger for the G-C than for the
A-T pairs. With this coupling constant we study tunneling in the DNA molecule.
The rates and the nature of tunneling have strong dependence on the DNA
sequence. By changing the trap positions in the molecular bridge the tunneling
rate can by varied up to seven orders of magnitude.


title: Fastest mixing Markov chain on graphs with symmetries

abstract:
  We show how to exploit symmetries of a graph to efficiently compute the
fastest mixing Markov chain on the graph (i.e., find the transition
probabilities on the edges to minimize the second-largest eigenvalue modulus of
the transition probability matrix). Exploiting symmetry can lead to significant
reduction in both the number of variables and the size of matrices in the
corresponding semidefinite program, thus enable numerical solution of
large-scale instances that are otherwise computationally infeasible. We obtain
analytic or semi-analytic results for particular classes of graphs, such as
edge-transitive and distance-transitive graphs. We describe two general
approaches for symmetry exploitation, based on orbit theory and
block-diagonalization, respectively. We also establish the connection between
these two approaches.


title: The gas density around SN 1006

abstract:
  The density of the ambient medium where the supernova remnant evolves is a
relevant parameter for its hydrodynamical evolution, for the mechanism of
particle acceleration, and for the emission at TeV energies. Using XMM-Newton
X-ray observations, we present a study of the ambient medium density of the
historical supernova remnant SN 1006. We modelled the post-shock thermal
emission to constrain the ambient medium density. Our study is focused on the
North-West and the South-East rims of the remnant, where the thermal emission
dominates. We used a plane-parallel shock plasma model plus another component
for the ejecta that are not negligible in the regions of our study. The
importance of the synchrotron component is also studied. In order to improve
statistics, we combined several observations of the remnant.
  The density found in the South-East rim is low, roughly 0.05 cm-3, and seems
to be representative of the rest of the remnant. However, in the North-West rim
(close to the bright optical filament), the density is significantly higher
(about 0.15-0.25 cm-3). This confirms a picture of SN 1006 evolving in a
tenuous ambient medium, except in the North-West where the remnant has recently
encountered a denser region.
  A density this low is compatible with the non-detection of the remnant by the
HESS gamma-ray observatory. The lower density in the South-East implies a
higher shock speed of 4900 km/s, higher than that of 2890 km/s measured in the
North-West. This new estimate of the velocity could increase the maximum energy
that accelerated particles can reach to energies of about 1 PeV.


title:
Counting and Locating the Solutions of Polynomial Systems of Maximum
  Likelihood Equations, II: The Behrens-Fisher Problem

abstract:
  Let $\mu$ be a $p$-dimensional vector, and let $\Sigma_1$ and $\Sigma_2$ be
$p \times p$ positive definite covariance matrices. On being given random
samples of sizes $N_1$ and $N_2$ from independent multivariate normal
populations $N_p(\mu,\Sigma_1)$ and $N_p(\mu,\Sigma_2)$, respectively, the
Behrens-Fisher problem is to solve the likelihood equations for estimating the
unknown parameters $\mu$, $\Sigma_1$, and $\Sigma_2$. We shall prove that for
$N_1, N_2 > p$ there are, almost surely, exactly $2p+1$ complex solutions of
the likelihood equations. For the case in which $p = 2$, we utilize Monte Carlo
simulation to estimate the relative frequency with which a typical
Behrens-Fisher problem has multiple real solutions; we find that multiple real
solutions occur infrequently.


title: Spectroscopy and Strong Decays of Charmed Baryons

abstract:
  Spectroscopy and strong decays of the charmed baryons are reviewed. Possible
spin-parity quantum numbers of several newly observed charmed baryon resonances
are discussed. Strong decays of charmed baryons are analyzed in the framework
of heavy hadron chiral perturbation theory in which heavy quark symmetry and
chiral symmetry are synthesized.


title: The Morse-Bott inequalities via dynamical systems

abstract:
  Let $f:M \to \mathbb{R}$ be a Morse-Bott function on a compact smooth finite
dimensional manifold $M$. The polynomial Morse inequalities and an explicit
perturbation of $f$ defined using Morse functions $f_j$ on the critical
submanifolds $C_j$ of $f$ show immediately that $MB_t(f) = P_t(M) + (1+t)R(t)$,
where $MB_t(f)$ is the Morse-Bott polynomial of $f$ and $P_t(M)$ is the
Poincar\'e polynomial of $M$. We prove that $R(t)$ is a polynomial with
nonnegative integer coefficients by showing that the number of gradient flow
lines of the perturbation of $f$ between two critical points $p,q \in C_j$
coincides with the number of gradient flow lines between $p$ and $q$ of the
Morse function $f_j$. This leads to a relationship between the kernels of the
Morse-Smale-Witten boundary operators associated to the Morse functions $f_j$
and the perturbation of $f$. This method works when $M$ and all the critical
submanifolds are oriented or when $\mathbb{Z}_2$ coefficients are used.


title: Exact edge singularities and dynamical correlations in spin-1/2 chains

abstract:
  Exact formulas for the singularities of the dynamical structure factor,
S^{zz}(q,omega), of the S=1/2 xxz spin chain at all q and any anisotropy and
magnetic field in the critical regime are derived, expressing the exponents in
terms of the phase shifts which are known exactly from the Bethe ansatz
solution. We also study the long time asymptotics of the self-correlation
function <0|S_j^z(t)S_j^z(0)|0>. Utilizing these results to supplement very
accurate time-dependent Density Matrix Renormalization Group (DMRG) for short
to moderate times, we calculate S^{zz}(q,omega) to very high precision.


title:
A New Distributed Topology Control Algorithm for Wireless Environments
  with Non-Uniform Path Loss and Multipath Propagation

abstract:
  Each node in a wireless multi-hop network can adjust the power level at which
it transmits and thus change the topology of the network to save energy by
choosing the neighbors with which it directly communicates. Many previous
algorithms for distributed topology control have assumed an ability at each
node to deduce some location-based information such as the direction and the
distance of its neighbor nodes with respect to itself. Such a deduction of
location-based information, however, cannot be relied upon in real environments
where the path loss exponents vary greatly leading to significant errors in
distance estimates. Also, multipath effects may result in different signal
paths with different loss characteristics, and none of these paths may be
line-of-sight, making it difficult to estimate the direction of a neighboring
node. In this paper, we present Step Topology Control (STC), a simple
distributed topology control algorithm which reduces energy consumption while
preserving the connectivity of a heterogeneous sensor network without use of
any location-based information. We show that the STC algorithm achieves the
same or better order of communication and computational complexity when
compared to other known algorithms that also preserve connectivity without the
use of location-based information. We also present a detailed simulation-based
comparative analysis of the energy savings and interference reduction achieved
by the algorithms. The results show that, in spite of not incurring a higher
communication or computational complexity, the STC algorithm performs better
than other algorithms in uniform wireless environments and especially better
when path loss characteristics are non-uniform.


title:
An Estimation of the Gamma-Ray Burst Afterglow Apparent Optical
  Brightness Distribution Function

abstract:
  By using recent publicly available observational data obtained in conjunction
with the NASA Swift gamma-ray burst mission and a novel data analysis
technique, we have been able to make some rough estimates of the GRB afterglow
apparent optical brightness distribution function. The results suggest that 71%
of all burst afterglows have optical magnitudes with mR < 22.1 at 1000 seconds
after the burst onset, the dimmest detected object in the data sample. There is
a strong indication that the apparent optical magnitude distribution function
peaks at mR ~ 19.5. Such estimates may prove useful in guiding future plans to
improve GRB counterpart observation programs. The employed numerical techniques
might find application in a variety of other data analysis problems in which
the intrinsic distributions must be inferred from a heterogeneous sample.


title: Enhanced sensitivity to variation of $m_{e}/m_{p}$ in molecular spectra

abstract:
  We propose new experiments with high sensitivity to a possible spatial or
temporal variation of the electron-to-proton mass ratio $\mu \equiv m_e/m_p$.
We consider a nearly-degenerate pair of molecular vibrational levels, where
each state is associated with a different electronic potential. The change in
the splitting between such levels, with respect to a change in $\mu$, can be
large both on an absolute scale and relative to the splitting. We demonstrate
the existence of such pairs of levels in Cs$_2$. The narrow spectral lines
achievable with ultracold Cs$_2$ in these long-lived levels make this system
promising for future searches for small variations in $\mu$.


title: Computing quantum phase transitions

abstract:
  This article first gives a concise introduction to quantum phase transitions,
emphasizing similarities with and differences to classical thermal transitions.
After pointing out the computational challenges posed by quantum phase
transitions, a number of successful computational approaches is discussed. The
focus is on classical and quantum Monte Carlo methods, with the former being
based on the quantum-to classical mapping while the latter directly attack the
quantum problem. These methods are illustrated by several examples of quantum
phase transitions in clean and disordered systems.


title:
The Induced Bounded-Degree Subgraph Problem and Stream Control in MIMO
  Networks

abstract:
  In this report, we consider maximal solutions to the induced bounded-degree
subgraph problem and relate it to issues concerning stream control in
multiple-input multiple-output (MIMO) networks. We present a new distributed
algorithm that completes in logarithmic time with high probability and is
guaranteed to complete in linear time. We conclude the report with simulation
results that address the effectiveness of stream control and the relative
impact of receiver overloading and flexible interference suppression.


title: Can giant planets form by gravitational fragmentation of discs?

abstract:
  Gravitational fragmentation has been proposed as a mechanism for the
formation of giant planets in close orbits around solar-type stars. However, it
is debatable whether this mechanism can function in the inner regions (R<40 AU)
of real discs. We use a newly developed method for treating the energy equation
and the equation of state, which accounts for radiative transfer effects in SPH
simulations of circumstellar discs. The different chemical and internal states
of hydrogen and the properties of dust at different densities and temperatures
(ice coated dust grains at low temperatures, ice melting, dust sublimation) are
all taken into account by the new method.We present radiative hydrodynamic
simulations of the inner regions of massive circumstellar discs and examine two
cases: (i) a disc irradiated by a cool background radiation field
(T_bgr=10K)and (ii) a disc heated by radiation from its central star
(T_bgr~1/R). In neither case does the disc fragment: in the former because it
cannot cool fast enough and in the latter because it is not gravitationally
unstable. Our results (a) corroborate previous numerical results using
different treatments for the hydrodynamics and the radiative transfer, and (b)
confirm our own earlier analytic predictions. We conclude that disc
fragmentation is unlikely to be able to produce giant planets around solar-type
stars at radii <40 AU.


title: Fault Tolerance in Cellular Automata at High Fault Rates

abstract:
  A commonly used model for fault-tolerant computation is that of cellular
automata. The essential difficulty of fault-tolerant computation is present in
the special case of simply remembering a bit in the presence of faults, and
that is the case we treat in this paper. We are concerned with the degree (the
number of neighboring cells on which the state transition function depends)
needed to achieve fault tolerance when the fault rate is high (nearly 1/2). We
consider both the traditional transient fault model (where faults occur
independently in time and space) and a recently introduced combined fault model
which also includes manufacturing faults (which occur independently in space,
but which affect cells for all time). We also consider both a purely
probabilistic fault model (in which the states of cells are perturbed at
exactly the fault rate) and an adversarial model (in which the occurrence of a
fault gives control of the state to an omniscient adversary). We show that
there are cellular automata that can tolerate a fault rate $1/2 - \xi$ (with
$\xi>0$) with degree $O((1/\xi^2)\log(1/\xi))$, even with adversarial combined
faults. The simplest such automata are based on infinite regular trees, but our
results also apply to other structures (such as hyperbolic tessellations) that
contain infinite regular trees. We also obtain a lower bound of
$\Omega(1/\xi^2)$, even with purely probabilistic transient faults only.


title:
Characteristics of EGRET Blazars in the VLBA Imaging and Polarimetry
  Survey (VIPS)

abstract:
  We examine the radio properties of EGRET-detected blazars observed as part of
the VLBA Imaging and Polarimetry Survey (VIPS). VIPS has a flux limit roughly
an order of magnitude below the MOJAVE survey and most other samples that have
been used to study the properties of EGRET blazars. At lower flux levels, radio
flux density does not directly correlate with gamma-ray flux density. We do
find that the EGRET-detected blazars tend to have higher brightness
temperatures, greater core fractions, and possibly larger than average jet
opening angles. A weak correlation is also found with jet length and with
polarization. All of the well-established trends can be explained by
systematically larger Doppler factors in the gamma-ray loud blazars, consistent
with the measurements of higher apparent velocities found in monitoring
programs carried out at radio frequencies above 10 GHz.


title: Chiral vibrations in the A=135 region

abstract:
  Chiral vibrations are studied with the RPA plus self-consistent tilted axis
cranking formalism in the A=135 region. In this method chiral vibrations appear
as a precursor to the static chiral regime. The properties of the RPA phonons
are discussed and compared to experimental data. We discuss the limits the
chiral region and the transition to the non harmonic regime.


title: A Bayesian periodogram finds evidence for three planets in HD 11964

abstract:
  A Bayesian multi-planet Kepler periodogram has been developed for the
analysis of precision radial velocity data (Gregory 2005b and 2007). The
periodogram employs a parallel tempering Markov chain Monte Carlo algorithm.
The HD 11964 data (Butler et al. 2006) has been re-analyzed using 1, 2, 3 and 4
planet models. Assuming that all the models are equally probable a priori, the
three planet model is found to be >= 600 times more probable than the next most
probable model which is a two planet model. The most probable model exhibits
three periods of 38.02+0.06-0.05, 360+-4 and 1924+44-43 d, and eccentricities
of 0.22+0.11-0.22, 0.63+0.34-0.17 and 0.05+0.03-0.05, respectively. Assuming
the three signals (each one consistent with a Keplerian orbit) are caused by
planets, the corresponding limits on planetary mass (M sin i) and semi-major
axis are 0.090+0.15-0.14 M_J, 0.253+-0.009 au, 0.21+0.06-0.07 M_J, 1.13+-0.04
au, 0.77+-0.08 M_J, 3.46+-0.13 au, respectively. The small difference (1.3
sigma) between the 360 day period and one year suggests that it might be worth
investigating the barycentric correction for the HD 11964 data.


title: $k$-Ribbon Fibonacci Tableaux

abstract:
  We extend the notion of $k$-ribbon tableaux to the Fibonacci lattice, a
differential poset defined by R. Stanley in 1975. Using this notion, we
describe an insertion algorithm that takes $k$-colored permutations to pairs of
$k$-ribbon Fibonacci tableaux of the same shape, and we demonstrate a
color-to-spin property, similar to that described by Shimozono and White for
ribbon tableaux. We give an evacuation algorithm which relates the pair of
$k$-ribbon Fibonacci tableaux obtained through the insertion algorithm to the
pair of $k$-ribbon Fibonacci tableaux obtained using Fomin's growth diagrams.
In addition, we present an analogue of Knuth relations for $k$-colored
permutations and $k$-ribbon Fibonacci tableaux.


title:
Electron Energy Distributions at Relativistic Shock Sites: Observational
  Constraints from the Cygnus A Hotspots

abstract:
  We report new detections of the hotspots in Cygnus A at 4.5 and 8.0 microns
with the Spitzer Space Telescope. Together with detailed published radio
observations and synchrotron self-Compton modeling of previous X-ray
detections, we reconstruct the underlying electron energy spectra of the two
brightest hotspots (A and D). The low-energy portion of the electron
distributions have flat power-law slopes (s~1.5) up to the break energy which
corresponds almost exactly to the mass ratio between protons and electrons; we
argue that these features are most likely intrinsic rather than due to
absorption effects. Beyond the break, the electron spectra continue to higher
energies with very steep slopes s>3. Thus, there is no evidence for the
`canonical' s=2 slope expected in 1st order Fermi-type shocks within the whole
observable electron energy range. We discuss the significance of these
observations and the insight offered into high-energy particle acceleration
processes in mildly relativistic shocks.


title: Green-Schwarz, Nambu-Goto Actions, and Cayley's Hyperdeterminant

abstract:
  It has been recently shown that Nambu-Goto action can be re-expressed in
terms of Cayley's hyperdeterminant with the manifest SL(2,R) X SL(2,R) X
SL(2,R) symmetry. In the present paper, we show that the same feature is shared
by Green-Schwarz sigma-model for N=2 superstring whose target space-time is
D=2+2. When its zweibein field is eliminated from the action, it contains the
Nambu-Goto action which is nothing but the square root of Cayley's
hyperdeterminant of the pull-back in superspace \sqrt{\hyperdet(\Pi_{i
\a\Dot\a})} manifestly invariant under SL(2,R) X SL(2,R) X SL(2,R). The target
space-time D=2+2 can accommodate self-dual supersymmetric Yang-Mills theory.
Our action has also fermionic kappa-symmetry, satisfying the criterion for its
light-cone equivalence to Neveu-Schwarz-Ramond formulation for N=2 superstring.


title: Finding Paths and Cycles in Graphs

abstract:
  A polynomial time algorithm which detects all paths and cycles of all lengths
in form of vertex pairs (start, finish).


title: Multiloop realization of extended affine Lie algebras and Lie tori

abstract:
  An important theorem in the theory of infinite dimensional Lie algebras
states that any affine Kac-Moody algebra can be realized (that is to say
constructed explicitly) using loop algebras. In this paper, we consider the
corresponding problem for a class of Lie algebras called extended affine Lie
algebras (EALAs) that generalize affine algebras. EALAs occur in families that
are constructed from centreless Lie tori, so the realization problem for EALAs
reduces to the realization problem for centreless Lie tori. We show that all
but one family of centreless Lie tori can be realized using multiloop algebras
(in place of loop algebras). We also obtain necessary and sufficient for two
centreless Lie tori realized in this way to be isotopic, a relation that
corresponds to isomorphism of the corresponding families of EALAs.


title: Multifractal regime transition in a modified minority game model

abstract:
  The search for more realistic modeling of financial time series reveals
several stylized facts of real markets. In this work we focus on the
multifractal properties found in price and index signals. Although the usual
Minority Game (MG) models do not exhibit multifractality, we study here one of
its variants that does. We show that the nonsynchronous MG models in the
nonergodic phase is multifractal and in this sense, together with other
stylized facts, constitute a better modeling tool. Using the Structure Function
(SF) approach we detected the stationary and the scaling range of the time
series generated by the MG model and, from the linear (nonlinear) behavior of
the SF we identified the fractal (multifractal) regimes. Finally, using the
Wavelet Transform Modulus Maxima (WTMM) technique we obtained its multifractal
spectrum width for different dynamical regimes.


title: Frustration-driven successive metamagnetic transitions in TbB4

abstract:
  Resonant magnetic x-ray diffraction experiments on the Shastry-Sutherland
lattice TbB$_4$ were carried out under strong pulsed magnetic fields up to 30
T. TbB$_4$ exhibits a multi-step magnetization process above 16 T when magnetic
fields are applied along the c-axis. We examined the intensity of the 010
magnetic reflection as a function of magnetic field and found that the
magnetization plateau phases are accompanied by large XY components of magnetic
moments, in contrast to normal fractional magnetization plateau phases. The
magnetization was calculated using a simple spin model deduced from the above
result. Finally we propose that frustration is the key to understanding the
observed multi-step magnetization.


title:
Cyclotron modeling phase-resolved infrared spectroscopy of polars I: EF
  Eridani

abstract:
  We present phase-resolved low resolution infrared spectra of the polar EF
Eridani obtained over a period of 2 years with SPEX on the IRTF. The spectra,
covering the wavelength range 0.8 to 2.4 microns, are dominated by cyclotron
emission at all phases. We use a ``Constant Lambda'' prescription to attempt to
model the changing cyclotron features seen in the spectra. A single cyclotron
emission component with B = 12.6 MG, and a plasma temperature of kT = 5.0 keV,
does a reasonable job in matching the features seen in the H and K bands, but
fails to completely reproduce the morphology shortward of 1.6 microns. We find
that a two component model, where both components have similar properties, but
whose contributions differ with viewing geometry, provides an excellent fit to
the data. We discuss the implications of our models and compare them with
previously published results. In addition, we show that a cyclotron model with
similar properties to those used for modeling the infrared spectra, but with a
field strength of B = 115 MG, can explain the GALEX observations of EF Eri.


title: Rare Semileptonic Decays of Heavy Mesons with Flavor SU(3) Symmetry

abstract:
  In this paper, we calculate the decay rates of $D^+ \to D^0 e^+ \nu$, $D^+_S
\to D^0 e^+ \nu$, $B^0_S \to B^+ e^- \bar{\nu}$, $D^+_S \to D^+ e^- e^+$ and
$B^0_S \to B^0 e^-e^+$ semileptonic decay processes, in which only the light
quarks decay, while the heavy flavors remain unchanged. The branching ratios of
these decay processes are calculated with the flavor SU(3) symmetry. The
uncertainties are estimated by considering the SU(3) breaking effect. We find
that the decay rates are very tiny in the framework of the Standard Model. We
also estimate the sensitivities of the measurements of these rare decays at the
future experiments, such as BES-III, super-$B$ and LHC-$b$.


title: The Minimally Tuned Minimal Supersymmetric Standard Model

abstract:
  The regions in the Minimal Supersymmetric Standard Model with the minimal
amount of fine-tuning of electroweak symmetry breaking are presented for
general messenger scale. No a priori relations among the soft supersymmetry
breaking parameters are assumed and fine-tuning is minimized with respect to
all the important parameters which affect electroweak symmetry breaking. The
superpartner spectra in the minimally tuned region of parameter space are quite
distinctive with large stop mixing at the low scale and negative squark soft
masses at the high scale. The minimal amount of tuning increases enormously for
a Higgs mass beyond roughly 120 GeV.


title: A characterization of the rational normal curve

abstract:
  We give a characterization of the rational normal curve in terms of the rank
function associated to a curve.


title: Detecting Cosmic Strings in the CMB with the Canny Algorithm

abstract:
  Line discontinuities in cosmic microwave background anisotropy maps are a
distinctive prediction of models with cosmic strings. These signatures are
visible in anisotropy maps with good angular resolution and should be
identifiable using edge detection algorithms. One such algorithm is the Canny
algorithm. We study the potential of this algorithm to pick out the line
discontinuities generated by cosmic strings. By applying the algorithm to
small-scale microwave anisotropy maps generated from theoretical models with
and without cosmic strings, we find that, given an angular resolution of
several minutes of arc, cosmic strings can be detected down to a limit of the
mass per unit length of the string which is one order of magnitude lower than
the current upper bounds.


title: The Luminosity Function of Low-Redshift Abell Galaxy Clusters

abstract:
  We present the results from a survey of 57 low-redshift Abell galaxy clusters
to study the radial dependence of the luminosity function (LF). The dynamical
radius of each cluster, r200, was estimated from the photometric measurement of
cluster richness, Bgc. The shape of the LFs are found to correlate with radius
such that the faint-end slope, alpha, is generally steeper on the cluster
outskirts. The sum of two Schechter functions provides a more adequate fit to
the composite LFs than a single Schechter function. LFs based on the selection
of red and blue galaxies are bimodal in appearance. The red LFs are generally
flat for -22 < M_Rc < -18, with a radius-dependent steepening of alpha for M_Rc
> -18. The blue LFs contain a larger contribution from faint galaxies than the
red LFs. The blue LFs have a rising faint-end component (alpha ~ -1.7) for M_Rc
> -21, with a weaker dependence on radius than the red LFs. The dispersion of
M* was determined to be 0.31 mag, which is comparable to the median measurement
uncertainty of 0.38 mag. This suggests that the bright-end of the LF is
universal in shape at the 0.3 mag level. We find that M* is not correlated with
cluster richness when using a common dynamical radius. Also, we find that M* is
weakly correlated with BM-type such that later BM-type clusters have a brighter
M*. A correlation between M* and radius was found for the red and blue galaxies
such that M* fades towards the cluster center.


title: Characterization of the near-Earth Asteroid 2002NY40

abstract:
  In August 2002, the near-Earth asteroid 2002 NY40, made its closest approach
to the Earth. This provided an opportunity to study a near-Earth asteroid with
a variety of instruments. Several of the telescopes at the Maui Space
Surveillance System were trained at the asteroid and collected adaptive optics
images, photometry and spectroscopy. Analysis of the imagery reveals the
asteroid is triangular shaped with significant self-shadowing. The photometry
reveals a 20-hour period and the spectroscopy shows that the asteroid is a
Q-type.


title: Matterwave Transport Without Transit

abstract:
  Classically it is impossible to have transport without transit, i.e., if the
points one, two and three lie sequentially along a path then an object moving
from one to three must, at some point in time, be located at two. However, for
a quantum particle in a three-well system it is possible to transport the
particle between wells one and three such that the probability of finding it at
any time in the classically accessible state in well two is negligible. We
consider theoretically the analogous scenario for a Bose-Einstein condensate
confined within a three well system. In particular, we predict the adiabatic
transportation of an interacting Bose-Einstein condensate of 2000 Li atoms from
well one to well three without transiting the allowed intermediate region. To
an observer of this macroscopic quantum effect it would appear that, over a
timescale of the order of one second, the condensate had transported, but not
transited, a macroscopic distance of 20 microns between wells one and three.


title: Self-injective algebras and the second Hochschild cohomology group

abstract:
  In this paper we study the second Hochschild cohomology group
${HH}^2(\Lambda)$ of a finite dimensional algebra $\Lambda$. In particular, we
determine ${HH}^2(\Lambda)$ where $\Lambda$ is a finite dimensional
self-injective algebra of finite representation type over an algebraically
closed field $K$ and show that this group is zero for most such $\Lambda$; we
give a basis for ${HH}^2(\Lambda)$ in the few cases where it is not zero.


title: The combinatorics of associated Hermite polynomials

abstract:
  We develop a combinatorial model of the associated Hermite polynomials and
their moments, and prove their orthogonality with a sign-reversing involution.
We find combinatorial interpretations of the moments as complete matchings,
connected complete matchings, oscillating tableaux, and rooted maps and show
weight-preserving bijections between these objects. Several identities,
linearization formulas, the moment generating function, and a second
combinatorial model are also derived.


title: On the Embeddability of Skeleta of Spheres

abstract:
  We consider a generalization of the van Kampen-Flores Theorem and relate it
to the long-standing $g$-conjecture for simplicial spheres.


title: Trans-phonon effects in ultrafast nano-devices

abstract:
  We report a novel phenomenon in carbon nanotube (CNT) based devices, the
transphonon effects, which resemble the transonic effects in aerodynamics. It
is caused by dissipative resonance of nanotube phonons similar to the radial
breathing mode, and subsequent drastic surge of the dragging force on the
sliding tube, and multiple phonon barriers are encountered as the intertube
sliding velocity reaches critical values. It is found that the transphonon
effects can be tuned by applying geometric constraints or varying chirality
combinations of the nanotubes.


title:
Some discretizations of geometric evolution equations and the Ricci
  iteration on the space of Kahler metrics, I

abstract:
  In this article and in its sequel we propose the study of certain
discretizations of geometric evolution equations as an approach to the study of
the existence problem of some elliptic partial differential equations of a
geometric nature as well as a means to obtain interesting dynamics on certain
infinite-dimensional spaces. We illustrate the fruitfulness of this approach in
the context of the Ricci flow, as well as another flow, in Kahler geometry. We
introduce and study dynamical systems related to the Ricci operator on the
space of Kahler metrics that arise as discretizations of these flows. We pose
some problems regarding their dynamics. We point out a number of applications
to well-studied objects in Kahler and conformal geometry such as constant
scalar curvature metrics, Kahler-Ricci solitons, Nadel-type multiplier ideal
sheaves, balanced metrics, the Moser-Trudinger-Onofri inequality, energy
functionals and the geometry and structure of the space of Kahler metrics.
E.g., we obtain a new sharp inequality strengthening the classical
Moser-Trudinger-Onofri inequality on the two-sphere.


title: Comments on a faint old stellar system at 150 kpc

abstract:
  Context.Recent study of SDSS J1257+3419 has revealed that this stellar system
is either a faint and small dwarf galaxy or a faint and widely extended
globular cluster (see also arXiv:0709.0327 [astro-ph]). Aims.In this short
note, the author suggests that this system is one of the smallest dwarf
spheroidals (dSphs) in the Milky Way. Methods.We re-examine some observational
quantities of this object and check whether it can be bound system. Results. As
a result, we find the mass of SDSS J1257+3419 is the lowest of dSphs in the
Milky Way, and its mass density is typical of dSphs. Important is that the
tidal radius of SDSS J1257+3419 is much larger than its half-light radius. That
is, this very small dSph can be bound by its own gravity.


title: Graphene nano-ribbon under tension

abstract:
  The mechanical response of graphene nano-ribbon under tensile loading has
been investigated using atomistic simulation. Lattice symmetry dependence of
elastic properties are found, which fits prediction from Cauchy-Born rule well.
Concurrent brittle and ductile behaviors are observed in the failure process at
elastic limit, which dominates at low and high temperature respectively. In
addition, the free edges of finite width ribbon help to activate bond-flip
events and initialize ductile behavior.


title:
The Description of Information in 4-Dimensional Pseudo-Euclidean
  Information Space

abstract:
  This article is presented new method of description information systems in
abstract 4-dimensional pseudo-Euclidean information space (4-DPIES) with using
special relativity (SR) methods. This purpose core postulates of existence
4-DPIES are formulated. The theorem setting existence criteria of the invariant
velocity of the information transference is formulated and proved. One more
theorem allowed relating discrete parameters of information and continuous
space-time treating and also row of supplementary theorems is formulated and
proved. For description of dynamics and interaction of information, in article
is introduced general parameter of information - generalized information
emotion (GIE), reminding simultaneously on properties the mass and the charge.
At performing calculation of information observable parameters in the
information space is introduced continual integration methods of Feynman. The
applying idea about existence of GIE as measures of the information inertness
and the interaction carrier, and using continual integration methods of Feynman
can be calculated probability of information process in 4-DPIES. In this frame
presented approach has allowed considering information systems when interest is
presented with information processes, their related with concrete definition
without necessity. The relation between 4-DPIES and real systems parameters is
set at modelling of matching between observable processes and real phenomena
from information interpretation.


title:
Molecular dynamics simulations of reflection and adhesion behavior in
  Lennard-Jones cluster deposition

abstract:
  We conduct molecular dynamics simulations of the collision of atomic clusters
with a weakly-attractive surface. We focus on an intermediate regime, between
soft-landing and fragmentation, where the cluster undergoes deformation on
impact but remains largely intact, and will either adhere to the surface (and
possibly slide), or be reflected. We find that the outcome of the collision is
determined by the Weber number, We i.e. the ratio of the kinetic energy to the
adhesion energy, with a transition between adhesion and reflection occurring as
We passes through unity. We also identify two distinct collision regimes: in
one regime the collision is largely elastic and deformation of the cluster is
relatively small but in the second regime the deformation is large and the
adhesion energy starts to depend on the kinetic energy. If the transition
between these two regimes occurs at a similar kinetic energy to that of the
transition between reflection and adhesion, then we find that the probability
of adhesion for a cluster can be bimodal. In addition we investigate the
effects of the angle of incidence on adhesion and reflection. Finally we
compare our findings both with recent experimental results and with macroscopic
theories of particle collisions.


title: Inertial Screening in Sedimentation

abstract:
  We use particle image velocimetry to measure the sedimentation dynamics of a
semi-dilute suspension of non-Brownian spheres at Reynolds numbers, $0.001\le
Re\le 2.3$, extending from the Stokes to the moderately inertial regime. We
find that the onset of inertial corrections to Stokes sedimentation occurs when
the inertial screening length $l=a/Re$ becomes similar to the Stokes
sedimentation length $\xi_0$, at $Re_c= a/\xi_0\approx 0.05$. For $Re>Re_c$,
inertial screening significantly reduces both the magnitude and spatial extent
of the particle velocity fluctuations. A modified Hinch force balance model
connects the fluctuation magnitudes $\sigma_V/V$ to the correlation sizes
$\xi$.


title: $\Lambda d$ correlations from the $^4$He(stopped-$K^-$,$d$) reaction

abstract:
  We have observed an intense high-energy component in an inclusive
$^4$He(stopped $K^-$, $d$) spectrum. For back-to-back $\Lambda d$ pairs a
prominent event cluster has been found just below the
$m_{^4\textrm{He}}+m_{K^-}-m_{n}$ mass threshold in the $\Lambda d$ invariant
mass spectrum of $\Lambda dn$ events, which is evidence for a three-nucleon
absorption process of $K^-$ in $^4$He. In addition, an appreciable strength is
revealed below $\sim$3220 MeV/$c^2$. Well separated $\Sigma^0 dn$ events show a
peak similar to the case of $\Lambda dn$.


title:
Short-time critical dynamics of the three-dimensional systems with
  long-range correlated disorder

abstract:
  Monte Carlo simulations of the short-time dynamic behavior are reported for
three-dimensional Ising and XY models with long-range correlated disorder at
criticality, in the case corresponding to linear defects. The static and
dynamic critical exponents are determined for systems starting separately from
ordered and disordered initial states. The obtained values of the exponents are
in a good agreement with results of the field-theoretic description of the
critical behavior of these models in the two-loop approximation and with our
results of Monte Carlo simulations of three-dimensional Ising model in
equilibrium state.


title: Teichm\"uller Spaces and Bundles with Negatively Curved Fibers

abstract:
  We study the Teichm\"uller space of negatively curved metrics on a high
dimensional manifold, with applications to bundles with negatively curved
fibers.


title:
Classification of Toric log Del Pezzo Surfaces having Picard Number 1
  and Index $\le 3$

abstract:
  Toric log Del Pezzo surfaces with Picard number 1 have been completely
classified whenever their index is $\le 2$: In this paper we extend the
classification for those having index 3: We prove that, up to isomorphism,
there are exactly 18 surfaces of this kind.


title: Measurement of the $K^+\to\pi^+\nu\bar{\nu}$ Branching Ratio

abstract:
  Experiment E949 at Brookhaven National Laboratory studied the rare decay
\$K^+\to\pi^+\nu\bar{\nu}$ and other processes with an exposure of $1.77\times
10^{12}$ $K^+$'s. The data were analyzed using a blind analysis technique
yielding one candidate event with an estimated background of $0.30\pm0.03$
events. Combining this result with the observation of two candidate events by
the predecessor experiment E787 gave the branching ratio
${\calB}(K^+\to\pi^+\nu\bar{\nu})=(1.47^{+1.30}_{-0.89})\times 10^{-10}$,
consistent with the Standard Model prediction of $(0.74\pm0.20)\times
10^{-10}$. This is a more detailed report of results previously published in
Physical Review Letters.


title:
Tunable high-energy ion source via oblique laser pulse incidence on a
  double-layer target

abstract:
  The laser-driven acceleration of high quality proton beams from a
double-layer target, comprised of a high-Z ion layer and a thin disk of
hydrogen, is investigated with three-dimensional particle-in-cell simulations
in the case of oblique incidence of a laser pulse. It is shown that the proton
beam energy reaches its maximum at a certain incidence angle of the laser
pulse, where it can be much greater than the energy at normal incidence. The
proton beam propagates at some angle with respect to the target surface normal,
as determined by the proton energy and the incidence angle.


title: Identification of shallow two-body bound states in finite volume

abstract:
  We discuss signatures of bound-state formation in finite volume via the
Luscher finite size method. Assuming that the phase-shift formula in this
method inherits all aspects of the quantum scattering theory, we may expect
that the bound-state formation induces the sign of the scattering length to be
changed. If it were true, this fact provides us a distinctive identification of
a shallow bound state even in finite volume through determination of whether
the second lowest energy state appears just above the threshold. We also
consider the bound-state pole condition in finite volume, based on Luscher's
phase-shift formula and then find that the condition is fulfilled only in the
infinite volume limit, but its modification by finite size corrections is
exponentially suppressed by the spatial lattice size L. These theoretical
considerations are also numerically checked through lattice simulations to
calculate the positronium spectrum in compact scalar QED, where the short-range
interaction between an electron and a positron is realized in the Higgs phase.


title: Weak lensing goes bananas: What flexion really measures

abstract:
  In weak gravitational lensing, the image distortion caused by shear measures
the projected tidal gravitational field of the deflecting mass distribution. To
lowest order, the shear is proportional to the mean image ellipticity. If the
image sizes are not small compared to the scale over which the shear varies,
higher-order distortions occur, called flexion. For ordinary weak lensing, the
observable quantity is not the shear, but the reduced shear, owing to the
mass-sheet degeneracy. Likewise, the flexion itself is unobservable. Rather,
higher-order image distortions measure the reduced flexion, i.e., derivatives
of the reduced shear. We derive the corresponding lens equation in terms of the
reduced flexion and calculate the resulting relation between brightness moments
of source and image. Assuming an isotropic distribution of source orientations,
estimates for the reduced shear and flexion are obtained; these are then tested
with simulations. In particular, the presence of flexion affects the
determination of the reduced shear. The results of these simulations yield the
amount of bias of the estimators, as a function of the shear and flexion. We
point out and quantify a fundamental limitation of the flexion formalism, in
terms of the product of reduced flexion and source size. If this product
increases above the derived threshold, multiple images of the source are formed
locally, and the formalism breaks down. Finally, we show how a general
(reduced) flexion field can be decomposed into its four components: two of them
are due to a shear field, carrying an E- and B-mode in general. The other two
components do not correspond to a shear field; they can also be split up into
corresponding E- and B-modes.


title:
Measurement of focusing properties for high numerical aperture optics
  using an automated submicron beamprofiler

abstract:
  The focusing properties of three aspheric lenses with numerical aperture (NA)
between 0.53 and 0.68 were directly measured using an interferometrically
referenced scanning knife-edge beam profiler with sub-micron resolution. The
results obtained for two of the three lenses tested were in agreement with
paraxial gaussian beam theory. It was also found that the highest NA aspheric
lens which was designed for 830nm was not diffraction limited at 633nm. This
process was automated using motorized translation stages and provides a direct
method for testing the design specifications of high numerical aperture optics.


title: A dynamical system approach to inhomogeneous dust solutions

abstract:
  We examine numerically and qualitatively the Lema\^\i tre--Tolman--Bondi
(LTB) inhomogeneous dust solutions as a 3--dimensional dynamical system
characterized by six critical points. One of the coordinates of the phase space
is an average density parameter, $<\Omega>$, which behaves as the ordinary
$\Omega$ in Friedman-Lema\^\i tre--Robertson--Walker (FLRW) dust spacetimes.
The other two coordinates, a shear parameter and a density contrast function,
convey the effects of inhomogeneity. As long as shell crossing singularities
are absent, this phase space is bounded or it can be trivially compactified.
This space contains several invariant subspaces which define relevant
particular cases, such as: ``parabolic'' evolution, FLRW dust and the
Schwarzschild--Kruskal vacuum limit. We examine in detail the phase space
evolution of several dust configurations: a low density void formation
scenario, high density re--collapsing universes with open, closed and wormhole
topologies, a structure formation scenario with a black hole surrounded by an
expanding background, and the Schwarzschild--Kruskal vacuum case. Solution
curves start expanding from a past attractor (source) in the plane
$<\Omega>=1$, associated with self similar regime at an initial singularity.
Depending on the initial conditions and specific configurations, the curves
approach several saddle points as they evolve between this past attractor and
other two possible future attractors: perpetually expanding curves terminate at
a line of sinks at $<\Omega>=0$, while collapsing curves reach maximal
expansion as $<\Omega>$ diverges and end up in sink that coincides with the
past attractor and is also associated with self similar behavior.


title:
A New Efficient Method of Hartree-Fock-Bogoliubov Calculation for Weakly
  Bound Nuclei

abstract:
  We propose a new method to solve the Hartree-Fock-Bogoliubov equations for
weakly bound nuclei, which works for both spherical and axially deformed cases.
In this approach, the quasiparticle wave functions are expanded in a complete
set of analytical Poschl-Teller-Ginocchio and Bessel/Coulomb wave functions.
Correct asymptotic properties of the quasiparticle wave functions are endowed
in the proposed algorithm. Good agreement is obtained with the results of the
Hartree-Fock-Bogoliubov calculation using the box boundary condition for a set
of benchmark spherical and deformed nuclei.


title: Reanalysis of the $e^+e^-\to\eta\gamma$ reaction cross section

abstract:
  In the experiment with the SND detector at the VEPP-2M $e^+e^-$ collider
measuring the $e^+e^-\to \eta\gamma$ cross section in the energy range
$0.6<\sqrt{s}<1.38 \mathrm{GeV}$ the reanalysis of data is performed. The goal
is to improve the accuracy of the previous results by analysing ambiguities in
the approximation of energy dependence of the $e^+e^-\to \eta\gamma$ cross
section, which were not taken into account in our previous study. We report new
results on the approximation of the $e^+e^-\to \eta\gamma$ cross section based
on Vector Dominance Model under new model parameter assumptions.


title:
Generalized solutions of the Cauchy problem for the Navier-Stokes system
  and diffusion processes

abstract:
  We reduce the construction of a weak solution of the Cauchy problem for the
Navier-Stokes system to the construction of a solution to a stochastic problem.
Namely, we construct diffusion processes which allow us to obtain a
probabilistic representation of a weak (in distributional sense) solution to
the Cauchy problem for the Navier- Stokes system.


title:
The H$\alpha$ Luminosity Function and Star Formation Rate at $z \approx
  0.24$ in the Cosmos 2 Square-Degree Field

abstract:
  To derive a new H$\alpha$ luminosity function and to understand the
clustering properties of star-forming galaxies at $z \approx 0.24$, we have
made a narrow-band imaging survey for H$\alpha$ emitting galaxies in the HST
COSMOS 2 square degree field. We used the narrow-band filter NB816 ($\lambda_c
= 8150$ \AA, $\Delta \lambda = 120$ \AA) and sampled H$\alpha$ emitters with
$EW_{\rm obs}(\rm H\alpha + [N\textsc{ii}]) > 12$ \AA in a redshift range
between $z=0.233$ and $z=0.251$ corresponding to a depth of 70 Mpc. We obtained
980 H$\alpha$ emitting galaxies in a sky area of 5540 arcmin$^2$, corresponding
to a survey volume of $3.1 \times 10^4 {\rm Mpc^3}$. We derive a H$\alpha$
luminosity function with a best-fit Schechter function parameter set of $\alpha
= -1.35^{+0.11}_{-0.13}$, $\log\phi_* = -2.65^{+0.27}_{-0.38}$, and $\log L_*
({\rm erg s^{-1}}) = 41.94^{+0.38}_{-0.23}$. The H$\alpha$ luminosity density
is $2.7^{+0.7}_{-0.6} \times 10^{39}$ ergs s$^{-1}$ Mpc$^{-3}$. After
subtracting the AGN contribution (15 %) to the H$\alpha$ luminosity density,
the star formation rate density is evaluated as $1.8^{+0.7}_{-0.4} \times
10^{-2}$ $M_{\sun}$ yr$^{-1}$ Mpc$^{-3}$. The angular two-point correlation
function of H$\alpha$ emitting galaxies of $\log L({\rm H\alpha}) > 39.8$ is
well fit by a power law form of $w(\theta) = 0.013^{+0.002}_{-0.001}
\theta^{-0.88 \pm 0.03}$, corresponding to the correlation function of $\xi(r)
= (r/1.9{\rm Mpc})^{-1.88}$. We also find that the H$\alpha$ emitters with
higher H$\alpha$ luminosity are more strongly clustered than those with lower
luminosity.


title:
On the Correspondence between Poincar\'e Symmetry of Commutative QFT and
  Twisted Poincar\'e Symmetry of Noncommutative QFT

abstract:
  The space-time symmetry of noncommutative quantum field theories with a
deformed quantization is described by the twisted Poincar\'e algebra, while
that of standard commutative quantum field theories is described by the
Poincar\'e algebra. Based on the equivalence of the deformed theory with a
commutative field theory, the correspondence between the twisted Poincar\'e
symmetry of the deformed theory and the Poincar\'e symmetry of a commutative
theory is established. As a by-product, we obtain the conserved charge
associated with the twisted Poincar\'e transformation to make the twisted
Poincar\'e symmetry evident in the deformed theory. Our result implies that the
equivalence between the commutative theory and the deformed theory holds in a
deeper level, i.e., it holds not only in correlation functions but also in
(different types of) symmetries.


title: Generic features of Einstein-Aether black holes

abstract:
  We reconsider spherically symmetric black hole solutions in Einstein-Aether
theory with the condition that this theory has identical PPN parameters as
those for general relativity, which is the main difference from the previous
research. In contrast with previous study, we allow superluminal propagation of
a spin-0 Aether-gravity wave mode. As a result, we obtain black holes having a
spin-0 "horizon" inside an event horizon. We allow a singularity at a spin-0
"horizon" since it is concealed by the event horizon. If we allow such a
configuration, the kinetic term of the Aether field can be large enough for
black holes to be significantly different from Schwarzschild black holes with
respect to ADM mass, innermost stable circular orbit, Hawking temperature, and
so on. We also discuss whether or not the above features can be seen in more
generic vector-tensor theories.


title:
Insertion of a magnesium(II)-octacarboranyl(hexylsulfanyl) porphyrazine
  into liposomes: a physico-chemical study

abstract:
  The synthesis, characterization and liposome insertion of a novel
magnesium(II) carboranyl-porphyrazine, i.e. [2,3,7,8,12,13,17,18-octakis-
(1,2-dicarba-closo-dodecaboranyl)-hexylthio-5,10,15,20-
porphyrazine]magnesium(II) complex, MgHECSPz, is described. MgHECSPz was
designed to improve the potentiality in multiple approach anticancer therapy.
Liposomal formulations with different surface charge were prepared as
delivering agents. The obtained loaded vectors were characterized by DLS, SAXS,
SANS and \zeta potential measurements in order to define the overall properties
and structural details of loaded liposomes.


title: Empirical processes indexed by estimated functions

abstract:
  We consider the convergence of empirical processes indexed by functions that
depend on an estimated parameter $\eta$ and give several alternative conditions
under which the ``estimated parameter'' $\eta_n$ can be replaced by its natural
limit $\eta_0$ uniformly in some other indexing set $\Theta$. In particular we
reconsider some examples treated by Ghoudi and Remillard [Asymptotic Methods in
Probability and Statistics (1998) 171--197, Fields Inst. Commun. 44 (2004)
381--406]. We recast their examples in terms of empirical process theory, and
provide an alternative general view which should be of wide applicability.


title:
Critical phenomena and renormalization-group flow of multi-parameter
  \Phi^4 field theories

abstract:
  In the framework of the renormalization-group (RG) approach, critical
phenomena can be investigated by studying the RG flow of multi-parameter
$\Phi^4$ field theories with an $N$-component fundamental field, containing up
to 4th-order polynomials of the field. Some physically interesting systems
require $\Phi^4$ field theories with several quadratic and quartic parameters,
depending essentially on their symmetry and symmetry-breaking pattern at the
transition. Results for their RG flow apply to disorder and/or frustrated
systems, anisotropic magnetic systems, density wave models, competing orderings
giving rise to multicritical behaviors. The general properties of the RG flow
in multi-parameter $\Phi^4$ field theories are discussed. An overview of
field-theoretical results for some physically interesting cases is presented,
and compared with other theoretical approaches and experiments. Finally, this
RG approach is applied to investigate the nature of the finite-temperature
transition of QCD with $N_f$ light quarks.


title:
Two-dimensional semiconducting nanostructures based on single graphene
  sheets with lines of adsorbed hydrogen atoms

abstract:
  It is shown that lines of adsorbed hydrogen pair atoms divide the graphene
sheet into strips and form hydrogen-based superlattice structures (2HG-SL). We
show that the forming of 2HG-SL drastically changes the electronic properties
of graphene from semimetal to semiconductor. The electronic spectra of "zigzag"
(n,0) 2HG-SL is similar to that of (n,0) carbon nanotubes and have a similar
oscillation of band gap with number n, but with non-zero minimal values. The
composite dual-periodic (n,0)+(m,0) 2HG-SLs of "zigzag" strips are analyzed,
with the conclusion that they may be treated as quasi-two-dimensional
heterostructures. We also suggest an experimental way of fabricating hydrogen
superlattices.


title: Charge Form Factor and Cluster Structure of $^6$Li Nucleus

abstract:
  The charge form factor of ${}^6$Li nucleus is considered on the basis of its
cluster structure. The charge density of ${}^6$Li is presented as a
superposition of two terms. One of them is a folded density and the second one
is a sum of ${}^4$He and the deuteron densities. Using the available
experimental data for ${}^4$He and deuteron charge form factors, a good
agreement of the calculations within the suggested scheme is obtained with the
experimental data for the charge form factor of ${}^6$Li, including those in
the region of large transferred momenta.


title:
A multibeam atom laser: coherent atom beam splitting from a single far
  detuned laser

abstract:
  We report the experimental realisation of a multibeam atom laser. A single
continuous atom laser is outcoupled from a Bose-Einstein condensate (BEC) via
an optical Raman transition. The atom laser is subsequently split into up to
five atomic beams with slightly different momenta, resulting in multiple,
nearly co-propagating, coherent beams which could be of use in interferometric
experiments. The splitting process itself is a novel realization of Bragg
diffraction, driven by each of the optical Raman laser beams independently.
This presents a significantly simpler implementation of an atomic beam
splitter, one of the main elements of coherent atom optics.


title:
Corner Multifractality for Reflex Angles and Conformal Invariance at 2D
  Anderson Metal-Insulator Transition with Spin-Orbit Scattering

abstract:
  We investigate boundary multifractality of critical wave functions at the
Anderson metal-insulator transition in two-dimensional disordered
non-interacting electron systems with spin-orbit scattering. We show
numerically that multifractal exponents at a corner with an opening angle
\theta=3\pi/2 are directly related to those near a straight boundary in the way
dictated by conformal symmetry. This result extends our previous numerical
results on corner multifractality obtained for \theta < \pi to \theta > \pi,
and gives further supporting evidence for conformal invariance at criticality.
We also propose a refinement of the validity of the symmetry relation of A. D.
Mirlin et al., Phys. Rev. Lett. \textbf{97} (2006) 046803, for corners.


title: Realistic Neutrinogenesis with Radiative Vertex Correction

abstract:
  We propose a new model for naturally light Dirac neutrinos and explain the
baryon asymmetry of the universe through neutrinogenesis. We extend the
standard model with a real singlet scalar, a heavy singlet Dirac fermion and a
heavy doublet scalar besides three right-handed neutrinos, respecting lepton
number conservation and a Z_2 symmetry. The neutrinos acquire small Dirac
masses due to the suppression of the weak scale over the heavy mass scale. As a
key feature of our construction, once the heavy Dirac fermion and doublet
scalar go out of equilibrium, their decays induce the CP asymmetry from the
interference of tree-level processes with the \textit{radiative vertex
corrections} (rather than the self-energy corrections). Although there is no
lepton number violation, an equal and opposite amount of CP asymmetry is
generated in the left-handed and the right-handed neutrinos. The left-handed
lepton asymmetry would then be converted to the baryon asymmetry in the
presence of the sphalerons, while the right-handed lepton asymmetry remains
unaffected.


title: Evolution Strategies in Optimization Problems

abstract:
  Evolution Strategies are inspired in biology and part of a larger research
field known as Evolutionary Algorithms. Those strategies perform a random
search in the space of admissible functions, aiming to optimize some given
objective function. We show that simple evolution strategies are a useful tool
in optimal control, permitting to obtain, in an efficient way, good
approximations to the solutions of some recent and challenging optimal control
problems.


title: Spacetime structure of 5D hypercylindrical vacuum solutions with tension

abstract:
  We investigate geometrical properties of 5D cylindrical vacuum solutions with
a transverse spherical symmetry. The metric is uniform along the fifth
direction and characterized by tension and mass densities. The solutions are
classified by the tension-to-mass ratio. One particular example is the
well-known Schwarzschild black string which has a curvature singularity
enclosed by a horizon. We focus mainly on geometry of other solutions which
possess a naked singularity. The light signal emitted by an object approaching
the singularity reaches a distant observer with finite time, but is infinitely
red-shifted.


title:
b\to s\nu\bar{\nu} decay in the MSSM: Implication of b\to s\gamma at
  large tan beta

abstract:
  The decay $b\to s\nu\bar{\nu}$ is discussed in the minimal supersymmetric
standard model with general flavor mixing for squarks, at large $\tan\beta$. In
this case, in addition to the chargino loop contributions which were analyzed
in previously studies, $\tan\beta$-enhanced contributions from the gluino and
charged Higgs boson loops might become sizable compared with the standard model
contribution, at least in principle. However, it is demonstrated that the
experimental bounds on the new physics contributions to the radiative decay
$b\to s\gamma$ should strongly constrain these contributions to $b\to
s\nu\bar{\nu}$, especially on the gluino contribution. We also briefly comment
on a possible constraint from the $B_s\to\mu^+\mu^-$ decay.


title: Constraint optimization and landscapes

abstract:
  We describe an effective landscape introduced in [1] for the analysis of
Constraint Satisfaction problems, such as Sphere Packing, K-SAT and Graph
Coloring. This geometric construction reexpresses these problems in the more
familiar terms of optimization in rugged energy landscapes. In particular, it
allows one to understand the puzzling fact that unsophisticated programs are
successful well beyond what was considered to be the `hard' transition, and
suggests an algorithm defining a new, higher, easy-hard frontier.

categories: quant-ph cond-mat.stat-mech cs.CC nlin.AO


title:
Computational performance of a parallelized high-order spectral and
  mortar element toolbox

abstract:
  In this paper, a comprehensive performance review of a MPI-based high-order
spectral and mortar element method C++ toolbox is presented. The focus is put
on the performance evaluation of several aspects with a particular emphasis on
the parallel efficiency. The performance evaluation is analyzed and compared to
predictions given by a heuristic model, the so-called Gamma model. A
tailor-made CFD computation benchmark case is introduced and used to carry out
this review, stressing the particular interest for commodity clusters.
Conclusions are drawn from this extensive series of analyses and modeling
leading to specific recommendations concerning such toolbox development and
parallel implementation.


title:
Coexistence of CDW with staggered superconductivity in a ferromagnetic
  material

abstract:
  In usual superconductivity (SC), the pairs have zero total momentum
irrespective of their symmetry. Staggered SC would involve, instead, pairs with
a finite commensurate total momentum, but such exotic states have never been
proven to be realized in nature. Here we study for the first time the influence
of particle-hole asymmetry on the competition of staggered SC with Charge
Density Waves (CDW) in a ferromagnetic medium. We obtain unprecedented
situations in which CDW and staggered SC coexist. We also obtain cases of a SC
dome near the collapse of a CDW state as well as cascades of transitions that
exhibit remarkable similarities with the pressure phase diagram in UGe$_2$
suggesting that SC in this material may be staggered coexisting and competing
with a CDW state.


title: Parton showers from the dipole formalism

abstract:
  We present an implementation of a parton shower algorithm for hadron
colliders and electron-positron colliders based on the dipole factorisation
formulae. The algorithm treats initial-state partons on equal footing with
final-state partons. We implemented the algorithm for massless and massive
partons.


title: A parton shower algorithm based on Catani-Seymour dipole factorisation

abstract:
  In this publication the implementation of a new parton shower model based on
the Catani-Seymour dipole factorisation, as first suggested by Z. Nagy and D.
E. Soper, is discussed. First results obtained with the new algorithm are
compared with experimental data.


title: Analytic evidence for the Gubser-Mitra conjecture

abstract:
  A simple master equation for the static perturbation of charged black strings
is derived while employing the gauge proposed by Kol. As the charge is varied
it is found that the potential in the master equation for the perturbations
becomes positive exactly when the specific heat turns positive thus forbidding
a bound state and the onset of the Gregory-Laflamme instability. It can safely
be said that this is the first analytic and explicit evidence for the
Gubser-Mitra conjecture, correlating the classical and thermodynamic
instabilities of black branes. Possible generalizations of the analysis are
also discussed.


title:
Four-lepton LHC events from MSSM Higgs boson decays into neutralino and
  chargino pairs

abstract:
  Heavy neutral Higgs boson production and decay into neutralino and chargino
pairs is studied at the Large Hadron Collider in the context of the Minimal
Supersymmetric Standard Model. Higgs boson decays into the heavier neutralino
and chargino states, i.e., H^0 or A^0 to tilde{chi}_i^0 tilde{chi}_j^0 (i,j =
2,3,4) as well as H^0 or A^0 to tilde{chi}_1^{pm} tilde{chi}_2^{mp},
tilde{chi}_2^+ tilde{chi}_2^- (all leading to four-lepton plus missing
transverse energy final states), is found to improve the possibilities of
discovering such Higgs states beyond those previously identified by considering
H^0 or A^0 to tilde{chi}_2^0 tilde{chi}_2^0 decays only. In particular, H^0,A^0
bosons with quite heavy masses, approaching ~800 GeV in the so-called
`decoupling region' where no clear SM signatures for the heavier MSSM Higgs
bosons are known to exist, can now be discerned, for suitable but not
particularly restrictive configurations of the low energy supersymmetric
parameters. The high M_A discovery reach for the H^0 and A^0 may thus be
greatly extended. Full event-generator level simulations, including realistic
detector effects and analyses of all significant backgrounds, are performed to
delineate the potential H^0,A^0 discovery regions. The wedgebox plot technique
is also utilized to further analyze the 4l plus missing transverse energy
signal and background events. This study marks the first thorough and
reasonably complete analysis of this important class of MSSM Higgs boson
signature modes. In fact, this is the first time discovery regions including
all possible neutralino and chargino decay modes of the Higgs bosons have ever
been mapped out.


title: Detection of long-lived staus and gravitinos at the ILC

abstract:
  A study is presented illustrating the excellent potential of future
  International Linear Collider (ILC) experiments to detect metastable staus
$\stau$, measure precisely their mass and lifetime, and to determine the mass
of the gravitino $\sG$ from the decay $\stau\to\tau\sG$, thus providing direct
access to the gravitational coupling, respectively Planck scale.


title: How to Detect `Decoupled' Heavy Supersymmetric Higgs Bosons

abstract:
  Heretofore neglected decay modes of heavy MSSM Higgs bosons into a variety of
neutralino pairs may push the LHC discovery reach for these crucial elements of
an extended Higgs sector to nearly the TeV-scale -- if sparticle-sector MSSM
input parameters are favorable. This is well into the so-called decoupling
region, including moderate to low tan(beta) values, where no known signals
exist for said heavy Higgs bosons via decays involving solely SM daughter
particles, and the lighter h^0 mimics the lone SM Higgs boson. While the
expanse of the Higgs to sparticle discovery region is sensitive to a number of
MSSM parameters, including in particular those for the sleptons, its presence
is primarily linked to the gaugino inputs -- in fact, to just one parameter,
M_2, if gaugino unification is invoked. Thus consideration of high vs. low M_2
realms in the MSSM should be placed on a par with the extensive consideration
already given to high vs. low tan(beta) regimes.


title:
Weyl asymptotics for magnetic Schr\"odinger operators and de Gennes'
  boundary condition

abstract:
  This paper is concerned with the discrete spectrum of the self-adjoint
realization of the semi-classical Schr\"odinger operator with constant magnetic
field and associated with the de Gennes (Fourier/Robin) boundary condition. We
derive an asymptotic expansion of the number of eigenvalues below the essential
spectrum (Weyl-type asymptotics). The methods of proof relies on results
concerning the asymptotic behavior of the first eigenvalue obtained in a
previous work [A. Kachmar, J. Math. Phys. Vol. 47 (7) 072106 (2006)].


title:
The investigation of particle acceleration in colliding-wind massive
  binaries with SIMBOL-X

abstract:
  An increasing number of early-type (O and Wolf-Rayet) colliding wind binaries
(CWBs) is known to accelerate particles up to relativistic energies. In this
context, non-thermal emission processes such as inverse Compton (IC) scattering
are expected to produce a high energy spectrum, in addition to the strong
thermal emission from the shock-heated plasma. SIMBOL-X will be the ideal
observatory to investigate the hard X-ray spectrum (above 10 keV) of these
systems, i.e. where it is no longer dominated by the thermal emission. Such
observations are strongly needed to constrain the models aimed at understanding
the physics of particle acceleration in CWB. Such systems are important
laboratories for investigating the underlying physics of particle acceleration
at high Mach number shocks, and probe a different region of parameter space
than studies of supernova remnants.


title:
Heat kernel estimates and spectral properties of a pseudorelativistic
  operator with magnetic field

abstract:
  Based on the Mehler heat kernel of the Schroedinger operator for a free
electron in a constant magnetic field an estimate for the kernel of E_A is
derived, where E_A represents the kinetic energy of a Dirac electron within the
pseudorelativistic no-pair Brown-Ravenhall model. This estimate is used to
provide the bottom of the essential spectrum for the two-particle
Brown-Ravenhall operator, describing the motion of the electrons in a central
Coulomb field and a constant magnetic field, if the central charge is
restricted to Z below or equal 86.


title:
Scaling and aging in the homogeneous cooling state of a granular fluid
  of hard particles

abstract:
  The presence of the aging phenomenon in the homogeneous cooling state (HCS)
of a granular fluid composed of inelastic hard spheres or disks is
investigated. As a consequence of the scaling property of the $N$-particle
distribution function, it is obtained that the decay of the normalized two-time
correlation functions slows down as the time elapsed since the beginning of the
measurement increases. This result is confirmed by molecular dynamics
simulations for the particular case of the total energy of the system. The
agreement is also quantitative in the low density limit, for which an explicit
analytical form of the time correlation function has been derived. The reported
results also provide support for the existence of the HCS as a solution of the
N-particle Liouville equation.


title: Longitudinal and Transverse Form Factors from $^{12}$C

abstract:
  Electron scattering form factors from $^{12}$C have been studied in the
framework of the particle-hole shell model. Higher configurations are taken
into account by allowing particle-hole excitations from the 1$s$ and 1$p$
shells core orbits up to the 1$f-2p$ shell. The inclusion of the higher
configurations modifies the form factors markedly and describes the
experimental data very well in all momentum transfer regions.


title: The joint large-scale foreground-CMB posteriors of the 3-year WMAP data

abstract:
  Using a Gibbs sampling algorithm for joint CMB estimation and component
separation, we compute the large-scale CMB and foreground posteriors of the
3-yr WMAP temperature data. Our parametric data model includes the cosmological
CMB signal and instrumental noise, a single power law foreground component with
free amplitude and spectral index for each pixel, a thermal dust template with
a single free overall amplitude, and free monopoles and dipoles at each
frequency. This simple model yields a surprisingly good fit to the data over
the full frequency range from 23 to 94 GHz. We obtain a new estimate of the CMB
sky signal and power spectrum, and a new foreground model, including a
measurement of the effective spectral index over the high-latitude sky. A
particularly significant result is the detection of a common spurious offset in
all frequency bands of ~ -13muK, as well as a dipole in the V-band data.
Correcting for these is essential when determining the effective spectral index
of the foregrounds. We find that our new foreground model is in good agreement
with template-based model presented by the WMAP team, but not with their MEM
reconstruction. We believe the latter may be at least partially compromised by
the residual offsets and dipoles in the data. Fortunately, the CMB power
spectrum is not significantly affected by these issues, as our new spectrum is
in excellent agreement with that published by the WMAP team. The corresponding
cosmological parameters are also virtually unchanged.


title: Emergent charge ordering in near half doped Na$_{0.46}$CoO$_{2}$

abstract:
  We have utilized neutron powder diffraction to probe the crystal structure of
layered Na$_{x}$CoO$_{2}$ near the half doping composition of $x=$0.46 over the
temperature range of 2 to 600K. Our measurements show evidence of a dynamic
transition in the motion of Na-ions at 300K which coincides with the onset of a
near zero thermal expansion in the in-plane lattice constants. The effect of
the Na-ordering on the CoO$_{2}$ layer is reflected in the octahedral
distortion of the two crystallographically inequivalent Co-sites and is evident
even at high temperatures. We find evidence of a weak charge separation into
stripes of Co$^{+3.5+\epsilon}$ and Co$^{+3.5-\epsilon}$, $\epsilon\sim0.06e$
below \Tco=150K. We argue that changes in the Na(1)-O bond lengths observed at
the magnetic transition at \tm=88K reflect changes in the electronic state of
the CoO$_{2}$ layer


title: Critical scaling of stochastic epidemic models

abstract:
  In the simple mean-field SIS and SIR epidemic models, infection is
transmitted from infectious to susceptible members of a finite population by
independent $p-$coin tosses. Spatial variants of these models are proposed, in
which finite populations of size $N$ are situated at the sites of a lattice and
infectious contacts are limited to individuals at neighboring sites. Scaling
laws for both the mean-field and spatial models are given when the infection
parameter $p$ is such that the epidemics are critical. It is shown that in all
cases there is a critical threshold for the numbers initially infected: below
the threshold, the epidemic evolves in essentially the same manner as its
branching envelope, but at the threshold evolves like a branching process with
a size-dependent drift.


title:
What is Minimal Model of 3He Adsorbed on Graphite? -Importance of
  Density Fluctuations in 4/7 Registered Solid -

abstract:
  We show theoretically that the second layer of 3He adsorbed on graphite and
solidified at 4/7 of the first-layer density is close to the fluid-solid
boundary with substantial density fluctuations on the third layer. The solid
shows a translational symmetry breaking as in charge-ordered insulators of
electronic systems. We construct a minimal model beyond the multiple-exchange
Heisenberg model. An unexpectedly large magnetic field required for the
measured saturation of magnetization is well explained by the density
fluctuations. The emergence of quantum spin liquid is understood from the same
mechanism as in the Hubbard model and in \kappa-(ET)_2Cu_2(CN)_3 near the Mott
transitions.


title: Rainich theory applied to m-rank tensors in n-dimensions

abstract:
  We show a tensorial-computational way to find out conditions that must fulfil
an m-rank tensor in arbitrary dimension in order to be algebraically the
energy-momentum tensor of some field. We apply in this paper our method to
three 2-rank tensors: electromagnetic, mass less scalar field and perfect fluid
tensors. Finally we apply the Rainich theory to some examples.