title: Model Independent Explorations of Majorana Neutrino Mass Origins

abstract:
  The scale of neutrino mass generation may be too large to explore directly,
but useful information may still be extracted from independent experimental
channels. Here I survey various model independent probes of Majorana neutrino
mass origins. An introduction to the concepts relevant to the analysis is
followed by a discussion of the physical ranges of neutrino parameters within
the context of standard and non-standard interactions. Armed with this, I move
on to systematically analyze the properties of radiatively generated neutrino
masses induced by nonrenormalizable lepton number violating effective operators
of mass dimensions five through eleven. By fitting these to the observed light
mass scale, I extract predictions for neutrino mixing as well as neutrinoless
double beta decay, rare meson/tau decays and collider phenomenology. I find
that many such models are already constrained by current data and many more
will be probed in the near future. I then move on demonstrate the utility of a
low scale seesaw mechanism via a viable sterile neutrino model that satisfies
all oscillation data as well as solves problems associated with supernova kicks
and heavy element nucleosynthesis. From this I extract predictions for tritium
and neutrinoless double beta decay searches.


title:
Response to "Comment on `Method of handling the divergences in the
  radiation theory of sources that move faster than their own waves'" [J. Math.
  Phys. 40, 4331 (1999)]

abstract:
  There is a fundamental difference between the classical expression for the
retarded electromagnetic potential and the corresponding retarded solution of
the wave equation that governs the electromagnetic field. While the boundary
contribution to the retarded solution for the potential can always be rendered
equal to zero by means of a gauge transformation that preserves the Lorenz
condition, the boundary contribution to the retarded solution of the wave
equation governing the field may be neglected only if it diminishes with
distance faster than the contribution of the source density in the far zone. In
the case of a source whose distribution pattern rotates superluminally (i.e.,
faster than the speed of light in vacuo), the boundary term in the retarded
solution governing the field is by a factor of the order of R^(1/2) larger than
the source term of this solution in the limit where the distance R of the
boundary from the source tends to infinity. This result is consistent with the
prediction of the retarded potential that the radiation field generated by a
rotating superluminal source decays as 1/R^(1/2), instead of 1/R. It also
explains why an argument based on the solution of the wave equation governing
the field in which the boundary term is neglected, such as Hannay presents in
his Comment, misses the nonspherical decay of the field.


title: Electron-electron interactions in graphene bilayers

abstract:
  We study the effect of electron-electron interactions in the quasiparticle
dispersion of a graphene bilayer within the Hartree-Fock-Thomas-Fermi theory by
using a four-bands model. We find that the electronic fluid can be described by
a non-interacting-like dispersion but with renormalized parameters. We compare
our results with recent cyclotron resonance experiments in this system.


title:
The Host Galaxies of Short-Duration Gamma-Ray Bursts: Luminosities,
  Metallicities, and Star Formation Rates

abstract:
  The association of some short-duration gamma-ray bursts (GRBs) with
elliptical galaxies established that their progenitors, unlike those of long
GRBs, belong to an old stellar population. However, the majority of short GRBs
appear to occur in star forming galaxies, raising the possibility that some
progenitors are related to recent star formation activity. Here we present
optical spectroscopy of these hosts and measure their luminosities, star
formation rates, and metallicities. We find luminosities of L_B~0.1-1.5 L*,
star formation rates of SFR~0.2-6 M_sun/yr, and metallicities of
12+log(O/H)~8.5-8.9 (Z~0.6-1.6 Z_sun). A detailed comparison to the hosts of
long GRBs reveals systematically higher luminosities, lower specific star
formation rates (SFR/L_B) by about an order of magnitude, and higher
metallicities by about 0.6 dex. The K-S probability that the short and long GRB
hosts are drawn from the same underlying galaxy distribution is only 10^-3. On
the other hand, short GRB hosts exhibit excellent agreement with the specific
star formation rates and the luminosity-metallicity relation of field galaxies
at z~0.1-1. We thus conclude that short GRB hosts are not dominated by young
stellar populations like long GRBs hosts. Instead, short GRB hosts appear to be
drawn uniformly from the underlying galaxy distribution, indicating that the
progenitors have a wide age distribution of several Gyr.


title:
Disentangling Visibility and Self-Promotion Bias in the arXiv:astro-ph
  Positional Citation Effect

abstract:
  We established in an earlier study that articles listed at or near the top of
the daily arXiv:astro-ph mailings receive on average significantly more
citations than articles further down the list. In our earlier work we were not
able to decide whether this positional citation effect was due to author
self-promotion of intrinsically more citable papers or whether papers are cited
more often simply because they are at the top of the astro-ph listing. Using
new data we can now disentangle both effects. Based on their submission times
we separate articles into a self-promoted sample and a sample of articles that
achieved a high rank on astro-ph by chance and compare their citation
distributions with those of articles on lower astro-ph positions. We find that
the positional citation effect is a superposition of self-promotion and
visibility bias.


title: The Role of Environment in the Mass-Metallicity Relation

abstract:
  Using a sample of 57,377 star-forming galaxies drawn from the Sloan Digital
Sky Survey, we study the relationship between gas-phase oxygen abundance and
environment in the local Universe. We find that there is a strong relationship
between metallicity and environment such that more metal-rich galaxies favor
regions of higher overdensity. Furthermore, this metallicity-density relation
is comparable in strength to the color-density relation along the blue cloud.
After removing the mean dependence of environment on color and luminosity, we
find a significant residual trend between metallicity and environment that is
largely driven by galaxies in high-density regions, such as groups and
clusters. We discuss the potential source of this relationship between
metallicity and local galaxy density in the context of feedback models, with
special attention paid to quantifying the impact of environment on the scatter
in the mass-metallicity relation. We find that environment is a non-negligible
source of scatter in this fundamental relation, with > 15% of the measured
scatter correlated with environment.


title:
A New Channel for Detecting Dark Matter Substructure in Galaxies:
  Gravitational Lens Time Delays

abstract:
  We show that dark matter substructure in galaxy-scale halos perturbs the time
delays between images in strong gravitational lens systems. The variance of the
effect depends on the subhalo mass function, scaling as the product of the
substructure mass fraction and a characteristic mass of subhalos (namely
<m^2>/<m>). Time delay perturbations therefore complement gravitational lens
flux ratio anomalies and astrometric perturbations by measuring a different
moment of the subhalo mass function. Unlike flux ratio anomalies, "time delay
millilensing" is unaffected by dust extinction or stellar microlensing in the
lens galaxy. Furthermore, we show that time delay ratios are immune to the
radial profile degeneracy that usually plagues lens modeling. We lay out a
mathematical theory of time delay perturbations and find it to be tractable and
attractive. We predict that in "cusp" lenses with close triplets of images,
substructure may change the arrival-time order of the images (compared with
smooth models). We discuss the possibility that this effect has already been
observed in RX J1131-1231.


title: A Halo Model of Galaxy Colors and Clustering in the SDSS

abstract:
  Successful halo-model descriptions of the luminosity dependence of clustering
distinguish between the central galaxy in a halo and all the others
(satellites). To include colors, we provide a prescription for how the
color-magnitude relation of centrals and satellites depends on halo mass. This
follows from two assumptions: (i) the bimodality of the color distribution at
fixed luminosity is independent of halo mass, and (ii) the fraction of
satellite galaxies which populate the red sequence increases with luminosity.
We show that these two assumptions allow one to build a model of how galaxy
clustering depends on color without any additional free parameters than those
required to model the luminosity dependence of galaxy clustering. We then show
that the resulting model is in good agreement with the distribution and
clustering of colors in the SDSS, both by comparing the predicted correlation
functions of red and blue galaxies with measurements, and by comparing the
predicted color mark correlation function with the measured one. Mark
correlation functions are powerful tools for identifying and quantifying
correlations between galaxy properties and their environments: our results
indicate that the correlation between halo mass and environment is the primary
driver for correlations between galaxy colors and the environment; additional
correlations associated with halo `assembly bias' are relatively small. Our
approach shows explicitly how to construct mock catalogs which include both
luminosities {\em and} colors -- thus providing realistic training sets for,
e.g., galaxy cluster finding algorithms. Our prescription is the first step
towards incorporating the entire spectral energy distribution into the halo
model approach.


title:
Clifford Algebras, Clifford Groups, and a Generalization of the
  Quaternions

abstract:
  One of the main goals of these notes is to explain how rotations in reals^n
are induced by the action of a certain group, Spin(n), on reals^n, in a way
that generalizes the action of the unit complex numbers, U(1), on reals^2, and
the action of the unit quaternions, SU(2), on reals^3 (i.e., the action is
defined in terms of multiplication in a larger algebra containing both the
group Spin(n) and reals^n). The group Spin(n), called a spinor group, is
defined as a certain subgroup of units of an algebra, Cl_n, the Clifford
algebra associated with reals^n.
  Since the spinor groups are certain well chosen subgroups of units of
Clifford algebras, it is necessary to investigate Clifford algebras to get a
firm understanding of spinor groups. These notes provide a tutorial on Clifford
algebra and the groups Spin and Pin, including a study of the structure of the
Clifford algebra Cl_{p, q} associated with a nondegenerate symmetric bilinear
form of signature (p, q) and culminating in the beautiful "8-periodicity
theorem" of Elie Cartan and Raoul Bott (with proofs).


title:
BD-22 5866: A Low-mass Quadruple-lined Spectroscopic AND Eclipsing
  Binary

abstract:
  We report our discovery of an extremely rare, low mass, quadruple-lined
spectroscopic binary BD-22 5866 (=NLTT 53279, integrated spectral type = M0 V),
found during an ongoing search for the youngest M dwarfs in the solar
neighborhood. From the cross-correlation function, we are able to measure
relative flux levels, estimate the spectral types of the components, and set
upper limits on the orbital periods and separations. The resulting system is
hierarchical composed of K7 + K7 binary and a M1 + M2 binary with semi-major
axes of asini_{A}<=0.06 AU and asini_{B}<=0.30 AU. A subsequent search of the
SuperWASP photometric database revealed that the K7 + K7 binary is eclipsing
with a period of 2.21 days and at an inclination angle of 85 degrees. Within
uncertainties of 5%, the masses and radii of both components appear to be equal
(0.59 Msun, 0.61 Rsun). These two tightly orbiting stars (a = 0.035 AU) are in
synchronous rotation causing the observed excess Ca II, Halpha, X-ray and UV
emission. The fact that the system was unresolved with published adaptive
optics imaging, limits the projected physical separation of the two binaries at
the time of the observation to d_{AB} < 4.1 AU at the photometric distance of
51 pc. The maximum observed radial velocity difference between the A and B
binaries limits the orbit to asini_{AB}<=6.1 AU. As this tight configuration is
difficult to reproduce with current formation models of multiple systems, we
speculate that an early dynamical process reduced the size of the system such
as the interaction of the two binaries with a circumquadruple disk. Intensive
photometric, spectroscopic and interferometric monitoring as well as a parallax
measurement of this rare quadruple system is certainly warranted.


title: On accelerated Universe expansion

abstract:
  It is shown that observed peculiarities of the Universe expansion are an
inevitable consequence of the gravitational force properties following from
gauge-invariant gravitation equations considered in detail in an author's paper
in Annalen der Physik, v.17, 28 (2008).


title:
Sums of norm spheres are norm shells and lower triangle inequalities are
  sharp

abstract:
  The statements in the title are explained and proved, as a little exercise in
elementary normed vector space theory at the level of Chapter 5 of
Dieudonn\'e's "Foundations of Mathematical Analysis". A connection to recent
moment bounds for submartingales is sketched.


title: On the large N limit of matrix integrals over the orthogonal group

abstract:
  We reexamine the large N limit of matrix integrals over the orthogonal group
O(N) and their relation with those pertaining to the unitary group U(N). We
prove that lim_{N to infty} N^{-2} \int DO exp N tr JO is half the
corresponding function in U(N), and a similar relation for lim_{N to infty}
\int DO exp N tr(A O B O^t), for A and B both symmetric or both skew symmetric.


title: Neutron scattering as a probe of the Fe-pnicitide superconducting gap

abstract:
  Inelastic neutron scattering provides a probe for studying the spin and
momentum structure of the superconducting gap. Here, using a two-orbital model
for the Fe-pnicitide superconductors and an RPA-BCS approximation for the
dynamic spin susceptibility, we explore the scattering response for various
gaps that have been proposed.


title:
Path Integral Monte Carlo and Density Functional Molecular Dynamics
  Simulations of Hot, Dense Helium

abstract:
  Two first-principles simulation techniques, path integral Monte Carlo (PIMC)
and density functional molecular dynamics (DFT-MD), are applied to study hot,
dense helium in the density-temperature range of 0.387 - 5.35 g/cc and 500 K -
1.28x10^8 K. One coherent equation of state (EOS) is derived by combining
DFT-MD data at lower temperatures with PIMC results at higher temperatures.
Good agreement between both techniques is found in an intermediate temperature
range. For the highest temperatures, the PIMC results converge to the
Debye-Hueckel limiting law. In order derive the entropy, a thermodynamically
consistent free energy fit is introduced that reproduces the internal energies
and pressure derived from the first-principles simulations. The equation of
state is presented in form of a table as well as a fit and is compared with
chemical models. In addition, the structure of the fluid is analyzed using pair
correlation functions. Shock Hugoniot curves are compared with recent laser
shock wave experiments.


title: Eotvos bounds on couplings of fundamental parameters to gravity

abstract:
  The possible dependence of fundamental couplings and mass ratios on the
gravitational potential has been bounded by comparing atomic clock frequencies
over Earth's elliptical orbit. Here we evaluate bounds on such dependence from
E"otv"os-type experiments that test the Weak Equivalence Principle, including
previously neglected contributions from nuclear binding energy. We find that
variations of fundamental parameters correlated with the gravitational
potential are bounded at 10^-8--10^-9, an improvement of 2--3 orders of
magnitude over atomic clock bounds.


title:
Comment on "Magnetic Order in the Pseudogap Phase of High-Tc
  Superconductors''

abstract:
  In a recent Letter, Fauque et al. [Phys. Rev. Lett. 96, 197001 (2006)]
reported the detection of a novel magnetic order in YBCO near the pseudogap
transition temperature T*. They remark that this magnetic order has not been
clearly identified by local probes and, in particular, by muon spin resonance.
The purpose of this Comment is to point out that this is untrue, and together
with the more recent detection of broken time reversal symmetry by polar Kerr
effect measurements [J. Xia et al. Phys. Rev. Lett. 100, 127002 (2008)], there
are now three very different kinds of experiments that provide evidence for
this magnetic transition.


title: On the norm convergence of nonconventional ergodic averages

abstract:
  We offer a generalization of the recent result of Tao (building on earlier
results of Conze and Lesigne, Furstenberg and Weiss, Zhang, Host and Kra,
Frantzikinakis and Kra and Ziegler) that the nonconventional ergodic averages
associated to an arbitrary number of commuting probability-preserving
transformations always converge to some limit in L^2. We prove the
corresponding result for a collection of commuting actions of a larger discrete
Abelian group, and gives convergence that is uniform in the start-point of the
averages. While Tao's proof rests on a conversion to a finitary problem, we
invoke only techniques from classical ergodic theory, so giving a new proof of
his result.


title:
Molecular Gas in the z=1.2 Ultraluminous Merger GOODS
  J123634.53+621241.3

abstract:
  We report the detection of CO(2-1) emission from the z=1.2 ultraluminous
infrared galaxy (ULIRG) GOODS J123634.53+621241.3 (also known as the
sub-millimeter galaxy GN26). These observations represent the first discovery
of high-redshift CO emission using the new Combined Array for Research in
Millimeter-Wave Astronomy (CARMA). Of all high-redshift (z>1) galaxies within
the GOODS-North field, this source has the largest far-infrared (FIR) flux
observed in the Spitzer 70um and 160um bands. The CO redshift confirms the
optical identification of the source, and the bright CO(2-1) line suggests the
presence of a large molecular gas reservoir of about 7x10^10 M(sun). The
infrared-to-CO luminosity ratio of L(IR)/L'(CO) = 80+/-30 L(sun) (K Km/s
pc^2)^-1 is slightly smaller than the average ratio found in local ULIRGs and
high-redshift sub-millimeter galaxies. The short star-formation time scale of
about 70 Myr is consistent with a starburst associated with the merger event
and is much shorter than the time scales for spiral galaxies and estimates made
for high-redshift galaxies selected on the basis of their B-z and z-K colors.


title: Thermal rectifier from deformed carbon nanohorns

abstract:
  We study thermal rectification in single-walled carbon nanohorns (SWNHs) by
using non-equilibrium molecular dynamics (MD) method. It is found that the
horns with the bigger top angles show larger asymmetric heat transport due to
the larger structural gradient distribution. This kind of gradient behavior can
be further adjusted by applying external strain on the SWNHs. After being
carefully elongated along the axial direction, the thermal rectification in the
elongated SWNHs can become more obvious than that in undeformed ones. The
maximum rectification efficiency of SWNHs is much bigger than that of carbon
nanotube intramolecular junctions.


title: On submanifolds with tamed second fundamental form

abstract:
  We show that a complete submanifold $M$ with tamed second fundamental form in
a complete Riemannian manifold $N$ with sectional curvature $K_{N}\leq \kappa
\leq 0$ are proper, (compact if $N$ is compact). In addition, if $N$ is
Hadamard then $M$ has finite topology. We also show that the fundamental tone
is an obstruction for a Riemannian manifold to be realized as submanifold with
tamed second fundamental form of a Hadamard manifold with sectional curvature
bounded below.


title: Width of homoclinic zone for quadratic maps

abstract:
  We study several families of planar quadratic diffeomorphisms near a
Bogdanov-Takens bifurcation. For each family, the associate bifurcation diagram
can be deduced from the interpolating flow. However, a zone of chaos confined
between two lines of homoclinic bifurcation that are exponentially close to
one-another is observed. The goal of this paper is to test numerically an
accurate asymptotic expansion for the width of this chaotic zone for different
families.


title: Flavon Inflation

abstract:
  We propose an entirely new class of particle physics models of inflation
based on the phase transition associated with the spontaneous breaking of
family symmetry responsible for the generation of the effective quark and
lepton Yukawa couplings. We show that the Higgs fields responsible for the
breaking of family symmetry, called flavons, are natural candidates for the
inflaton field in new inflation, or the waterfall fields in hybrid inflation.
This opens up a rich vein of possibilities for inflation, all linked to the
physics of flavour, with interesting cosmological and phenomenological
implications. Out of these, we discuss two examples which realise flavon
inflation: a model of new inflation based on the discrete non-Abelian family
symmetry group A_{4} or Delta_{27}, and a model of hybrid inflation embedded in
an existing flavour model with a continuous SU(3) family symmetry. With the
inflation scale and family symmetry breaking scale below the Grand Unification
Theory (GUT) scale, these classes of models are free of the monopole (and
similar) problems which are often associated with the GUT phase transition.


title:
Avalanches, branching ratios, and clustering of attractors in Random
  Boolean Networks and in the segment polarity network of \emph{Drosophila}

abstract:
  We discuss basic features of emergent complexity in dynamical systems far
from equilibrium by focusing on the network structure of their state space. We
start by measuring the distributions of avalanche and transient times in Random
Boolean Networks (RBNs) and in the \emph{Drosophila} polarity network by exact
enumeration. A transient time is the duration of the transient from a starting
state to an attractor. An avalanche is a special transient which starts as
single Boolean element perturbation of an attractor state. Significant
differences at short times between the avalanche and the transient times for
RBNs with small connectivity $K$ -- compared to the number of elements $N$ --
indicate that attractors tend to cluster in configuration space. In addition,
one bit flip has a non-negligible chance to put an attractor state directly
onto another attractor. This clustering is also present in the segment polarity
gene network of \emph{Drosophila melanogaster}, suggesting that this may be a
robust feature of biological regulatory networks. We also define and measure a
branching ratio for the state space networks and find evidence for a new time
scale that diverges roughly linearly with $N$ for $2\leq K \ll N$. Analytic
arguments show that this time scale does not appear in the random map nor can
the random map exhibit clustering of attractors. We further show that for K=2
the branching ratio exhibits the largest variation with distance from the
attractor compared to other values of $K$ and that the avalanche durations
exhibit no characteristic scale within our statistical resolution. Hence, we
propose that the branching ratio and the avalanche duration are new indicators
for scale-free behavior that may or may not be found simultaneously with other
indicators of emergent complexity in extended, deterministic dynamical systems.


title: Electron spin decoherence of single Nitrogen-Vacancy defects in diamond

abstract:
  We present a theoretical analysis of the electron spin decoherence in single
Nitrogen-Vacancy defects in ultra-pure diamond. The electron spin decoherence
is due to the interactions with Carbon-13 nuclear spins in the diamond lattice.
Our approach takes advantage of the low concentration (1.1%) of Carbon-13 and
their random distribution in the diamond lattice by an algorithmic aggregation
of spins into small, strongly interacting groups. By making use of this
\emph{disjoint cluster} approach, we demonstrate a possibility of non-trival
dynamics of the electron spin that can not be described by a single time
constant. This dependance is caused by a strong coupling between the electron
and few nuclei and results, in particular, in a substantial echo signal even at
microsecond time scales. Our results are in good agreement with recent
experimental observations.


title: Quantum Data Compression and Relative Entropy Revisited

abstract:
  B. Schumacher and M. Westmoreland have established a quantum analog of a
well-known classical information theory result on a role of relative entropy as
a measure of non-optimality in (classical) data compression. In this paper, we
provide an alternative, simple and constructive proof of this result by
constructing quantum compression codes (schemes) from classical data
compression codes. Moreover, as the quantum data compression/coding task can be
effectively reduced to a (quasi-)classical one, we show that relevant results
from classical information theory and data compression become applicable and
therefore can be extended to the quantum domain.


title: Branching Ratios and Polarization in B-> VV,VA,AA Decays

abstract:
  We present a detailed study of charmless two-body B decays into final states
involving two vector mesons (VV) or two axial-vector mesons (AA) or one vector
and one axial-vector meson (VA), within the framework of QCD factorization,
where $A$ is either a $^3P_1$ or $^1P_1$ axial-vector meson. The main results
are as follows. (i) In the presence of NLO nonfactorizable corrections,
effective Wilson coefficients $a_i^h$ are helicity dependent. For some
penguin-dominated modes, the constructive (destructive) interference in the
negative-helicity (longitudinal-helicity) amplitude of the $B\to VV$ decay will
render the former comparable to the latter and push up the transverse
polarization. (ii) In QCD factorization, the transverse polarization fraction
can be large for penguin-dominated charmless $VV$ modes by allowing for sizable
penguin annihilation contributions. (iii) Using the measured $\bar
K^{*0}\rho^-$ channel as an input, we predict the branching ratios and
polarization fractions for other $\ov B\to \bar K^*\rho$ decays. (iv) The
smallness of the axial-vector decay constant of the $^1P_1$ axial vector meson
can be tested by measuring various $b_1\rho$ modes to see if $\Gamma(\bar
B^0\to b_1^-\rho^+)\ll \Gamma(\bar B^0\to b_1^+\rho^-)$ and $\Gamma(B^-\to
b_1^-\rho^0)\ll \Gamma(B^-\to b_1^0\rho^-)$. (v) For the penguin-dominated
modes $a_1K^*$ and $b_1K^*$, it is found that the former are dominated by
transverse polarization amplitudes, whereas the latter are governed by
longitudinal polarization states.


title: Alternating Automata on Data Trees and XPath Satisfiability

abstract:
  A data tree is an unranked ordered tree whose every node is labelled by a
letter from a finite alphabet and an element ("datum") from an infinite set,
where the latter can only be compared for equality. The article considers
alternating automata on data trees that can move downward and rightward, and
have one register for storing data. The main results are that nonemptiness over
finite data trees is decidable but not primitive recursive, and that
nonemptiness of safety automata is decidable but not elementary. The proofs use
nondeterministic tree automata with faulty counters. Allowing upward moves,
leftward moves, or two registers, each causes undecidability. As corollaries,
decidability is obtained for two data-sensitive fragments of the XPath query
language.


title: Hot DQ White Dwarfs: Something Different

abstract:
  We present a detailed analysis of all the known Hot DQ white dwarfs in the
Fourth Data Release of the Sloan Digital Sky Survey (SDSS) recently found to
have carbon dominated atmospheres. Our spectroscopic and photometric analysis
reveals that these objects all have effective temperatures between ~18,000 and
24,000 K. The surface composition is found to be completely dominated by
carbon, as revealed by the absence of Hbeta and HeI 4471 lines (or
determination of trace amount in a few cases). We find that the surface gravity
of all objects but one seems to be ''normal'' and around log g = 8.0 while one
is likely near log g = 9.0. The presence of a weak magnetic field is directly
detected by spectropolarimetry in one object and is suspected in two others. We
propose that these strange stars could be cooled down versions of the weird
PG1159 star H1504+65 and form a new family of hydrogen and helium deficient
objects following the post-AGB phase. Finally, we present the results of full
nonadiabatic calculations dedicated specifically to each of the Hot DQ that
show that only SDSS J142625.70+575218.4 is expected to exhibit luminosity
variations. This result is in excellent agreement with recent observations by
Montgomery et al. who find that J142625.70+575218.4 is the only pulsator among
6 Hot DQ white dwarfs surveyed in February 2008.


title:
Entanglement Spectrum as a Generalization of Entanglement Entropy:
  Identification of Topological Order in Non-Abelian Fractional Quantum Hall
  Effect States

abstract:
  We study the "entanglement spectrum" (a presentation of the Schmidt
decomposition analogous to a set of "energy levels") of a many-body state, and
compare the Moore-Read model wavefunction for the $\nu$ = 5/2 fractional
quantum Hall state with a generic 5/2 state obtained by finite-size
diagonalization of the second-Landau-level-projected Coulomb interactions.
Their spectra share a common "gapless" structure, related to conformal field
theory. In the model state, these are the \textit{only} levels, while in the
"generic" case, they are separated from the rest of the spectrum by a clear
"entanglement gap", which appears to remain finite in the thermodynamic limit.
We propose that the low-lying entanglement spectrum can be used as a
"fingerprint" to identify topological order.


title: Wave propagation in the magnetic sun

abstract:
  This paper reports on efforts to simulate wave propagation in the solar
interior. Presented is work on extending a numerical code for constant entropy
acoustic waves in the absence of magnetic fields to the case where magnetic
fields are present. A set of linearized magnetohydrodynamic (MHD) perturbation
equations has been derived and implemented.


title: Resistance Quenching in Graphene Interconnects

abstract:
  We investigated experimentally the high-temperature electrical resistance of
graphene interconnects. The test structures were fabricated using the focused
ion beam from the single and bi-layer graphene produced by mechanical
exfoliation. It was found that as temperature increases from 300 to 500K the
resistance of the single- and bi-layer graphene interconnects drops down by 30%
and 70%, respectively. The quenching and temperature dependence of the
resistance were explained by the thermal generation of the electron-hole pairs
and acoustic phonon scattering. The obtained results are important for the
proposed applications of graphene as interconnects in integrated circuits.


title: Where Does the Energy Loss Lose Strength?

abstract:
  Nuclear modification factors for pion production in AuAu and CuCu collisions
are analyzed at very high transverse momenta. At p_T > 10 GeV/c, the
R_{AA}(p_T) is determined mostly by the initial state nuclear modifications
(e.g. EMC effect) and the non-Abelian jet-energy loss in the final state. At
high momenta these effects together are strong enough to suppress R_{AA}(p_T)
to below 1 at RHIC energies. We display results using HKN shadowing in our pQCD
improved parton model. Result of a similar calculation at LHC energies for PbPb
collisions are also displayed. Based on dN/dy estimates, a larger opacity
value, L/\lambda_g = 10 +/- 2, is used for the produced partonic matter in
central collisions at the LHC.


title: Flop Invariance of Refined Topological Vertex and Link Homologies

abstract:
  It has been proposed recently that the topological A-model string theory on
local toric Calabi-Yau manifolds has a two parameter extension. Amplitudes of
the two parameter topological strings can be computed using a diagrammatic
method called the refined topological vertex. In this paper we study properties
of the refined amplitudes under the flop transition of toric Calabi-Yau
three-folds. We also discuss that the slicing invariance and the flop
transition imply a simple formula for the homological sl(N) invariants of the
Hopf link. The new expression for the invariants gives a simple refinement of
the Hopf link invariant of Chern-Simons theory.


title: On Distributed Function Computation in Structure-Free Random Networks

abstract:
  We consider in-network computation of MAX in a structure-free random multihop
wireless network. Nodes do not know their relative or absolute locations and
use the Aloha MAC protocol. For one-shot computation, we describe a protocol in
which the MAX value becomes available at the origin in $O(\sqrt{n/\log n})$
slots with high probability. This is within a constant factor of that required
by the best coordinated protocol. A minimal structure (knowledge of
hop-distance from the sink) is imposed on the network and with this structure,
we describe a protocol for pipelined computation of MAX that achieves a rate of
$\Omega(1/(\log^2 n)).$


title:
SPH Simulations of Direct Impact Accretion in the Ultracompact AM CVn
  Binaries

abstract:
  The ultracompact binary systems V407 Vul (RX J1914.4+2456) and HM Cnc (RX
J0806.3+1527) - a two-member subclass of the AM CVn stars - continue to pique
interest because they defy unambiguous classification. Three proposed models
remain viable at this time, but none of the three is significantly more
compelling than the remaining two, and all three can satisfy the observational
constraints if parameters in the models are tuned. One of the three proposed
models is the direct impact model of Marsh & Steeghs (2002), in which the
accretion stream impacts the surface of a rapidly-rotating primary white dwarf
directly but at a near-glancing angle. One requirement of this model is that
the accretion stream have a high enough density to advect its specific kinetic
energy below the photosphere for progressively more-thermalized emission
downstream, a constraint that requires an accretion spot size of roughly
1.2x10^5 km^2 or smaller. Having at hand a smoothed particle hydrodynamics code
optimized for cataclysmic variable accretion disk simulations, it was
relatively straightforward for us to adapt it to calculate the footprint of the
accretion stream at the nominal radius of the primary white dwarf, and thus to
test this constraint of the direct impact model. We find that the mass flux at
the impact spot can be approximated by a bivariate Gaussian with standard
deviation \sigma_{\phi} = 164 km in the orbital plane and \sigma_{\theta} = 23
km in the perpendicular direction. The area of the the 2\sigma ellipse into
which 86% of the mass flux occurs is roughly 47,400 km^2, or roughly half the
size estimated by Marsh & Steeghs (2002). We discuss the necessary parameters
of a simple model of the luminosity distribution in the post-impact emission
region.


title: Quantum Knots and Mosaics

abstract:
  In this paper, we give a precise and workable definition of a quantum knot
system, the states of which are called quantum knots. This definition can be
viewed as a blueprint for the construction of an actual physical quantum
system.
  Moreover, this definition of a quantum knot system is intended to represent
the "quantum embodiment" of a closed knotted physical piece of rope. A quantum
knot, as a state of this system, represents the state of such a knotted closed
piece of rope, i.e., the particular spatial configuration of the knot tied in
the rope. Associated with a quantum knot system is a group of unitary
transformations, called the ambient group, which represents all possible ways
of moving the rope around (without cutting the rope, and without letting the
rope pass through itself.)
  Of course, unlike a classical closed piece of rope, a quantum knot can
exhibit non-classical behavior, such as quantum superposition and quantum
entanglement. This raises some interesting and puzzling questions about the
relation between topological and quantum entanglement.
  The knot type of a quantum knot is simply the orbit of the quantum knot under
the action of the ambient group. We investigate quantum observables which are
invariants of quantum knot type. We also study the Hamiltonians associated with
the generators of the ambient group, and briefly look at the quantum tunneling
of overcrossings into undercrossings.
  A basic building block in this paper is a mosaic system which is a formal
(rewriting) system of symbol strings. We conjecture that this formal system
fully captures in an axiomatic way all of the properties of tame knot theory.


abstract:
  We propose that the existence of Metastable Innershell Molecular State (MIMS)
was experimentally discovered by Bae et al. in hypervelocity (v>100km/s) impact
of nanoparticles. The decay of MIMS resulted in the observed intense soft
x-rays in the range of 75 - 100 eV in agreement with Winterberg's recent
prediction.


title: Nathanson's Heights and the CSS Conjecture for Cayley Graphs

abstract:
  Let $G$ be a finite directed graph, $\beta(G)$ the minimum size of a subset
$X$ of edges such that the graph $G' = (V,E \smallsetminus X)$ is directed
acyclic and $\gamma(G)$ the number of pairs of nonadjacent vertices in the
undirected graph obtained from $G$ by replacing each directed edge with an
undirected edge. Chudnovsky, Seymour and Sullivan \cite{CSS07} proved that if
$G$ is triangle-free, then $\beta(G) \leq \gamma(G)$. They conjectured a
sharper bound (so called the "CSS conjecture") that $\beta(G) \leq
\dfrac{\gamma(G)}{2}$. Nathanson and Sullivan verified this conjecture for the
directed Cayley graph $\Cay(\bbZ/N\bbZ, E_A)$ whose vertex set is the additive
group $\bbZ/N\bbZ$ and whose edge set $E_A$ is determined by $E_A = {(x,x+a) :
x \in \bbZ/N\bbZ, a \in A}$ when $N$ is prime in \cite{NS07} by introducing
"height". In this work, we extend the definition of height and the proof of CSS
conjecture for $\Cay(\bbZ/N\bbZ, E_A)$ to any positive integer $N$.


title: Central Limit Theorem for a Class of Linear Systems

abstract:
  We consider a class of interacting particle systems with values in
$[0,\8)^{\zd}$, of which the binary contact path process is an example. For $d
\ge 3$ and under a certain square integrability condition on the total number
of the particles, we prove a central limit theorem for the density of the
particles, together with upper bounds for the density of the most populated
site and the replica overlap.


title:
Exclusive Production of Quarkonia in $pp$ and $p \bar p$ Collisions Far
  from the Threshold

abstract:
  I discuss exclusive production of the $\eta'$, $J/\psi$, and $\chi_c(0^+)$
mesons in $pp$ and $p \bar p$ collisions at high energies. QCD diffractive
mechanisms as well as nondiffractive mechanisms are discussed. Different
unintegrated gluon distribution functions (UGDF) are used. Some differential
distributions are shown and discussed.


title:
The Effects of Thermal Conduction on the ADAF with a Toroidal Magnetic
  Field

abstract:
  The observation of the hot gas surrounding Sgr $A^*$ and a few other nearby
galactic nuclei imply that electron and proton mean free paths are comparable
to the gas capture radius. So, the hot accretion flows is likely to proceed
under week-collision conditions. Hence, thermal conduction has been suggested
as a possible mechanism by which the sufficient extra heating is provided in
hot ADAF accretion disks. We consider the effects of thermal conduction in the
presence of a toroidal magnetic field in an advection-dominated accretion flow
around a compact object. For a steady-state structure of such accretion flows a
set of self-similar solutions are presented. We find two types solutions which
represent high and slow accretion rate. They have different behaviors with
saturated thermal conduction parameter, $\phi$.


title: Universal spaces for manifolds equipped with a closed integral k-form

abstract:
  In this note we prove that any integral closed k-form $\phi ^k$, $k\ge 3$, on
a m-dimensional manifold $M^m$, $m \ge k$, is the restriction of a universal
closed k-form $h^k$ on a universal manifold $U^{d(m,k)}$ as a result of an
embedding of $M^m$ to $U^{d(m,k)}$.


title: Statistical mechanics of damage phenomena

abstract:
  This paper applies the formalism of classical, Gibbs-Boltzmann statistical
mechanics to the phenomenon of non-thermal damage. As an example, a non-thermal
fiber-bundle model with the global uniform (meanfield) load sharing is
considered. Stochastic topological behavior in the system is described in terms
of an effective temperature parameter thermalizing the system. An equation of
state and a topological analog of the energy-balance equation are obtained. The
formalism of the free energy potential is developed, and the nature of the
first order phase transition and spinodal is demonstrated.


title:
Application of classical statistical mechanics to multifractals and
  dynamical systems

abstract:
  Classical, self-consistent theory of statistical mechanics was developed for
the thermodynamic and conservative Hamiltonian systems. Later there were many
attempts (Sinai-Bowen-Ruelle's temperature, Tsallis' non-extensive theory) to
apply similar formalism to non-Hamiltonian dynamical systems. Although these
theories reveal aspects of complex behavior, they have limited applicability.
This paper applies the classical Gibbs-Boltzmann statistical mechanics to
complex systems such as i.i.d. processes, multifractals, and non-Hamiltonian
dynamical systems with strange attractors. The effective thermolization of
stochastic noise in the system is introduced and the formalism of a ruling
(governing, free energy) potential is developed.


abstract:
  In this note we introduce a Yang-Mills bar equation on complex vector bundles
over compact Hermitian manifolds as the Euler-Lagrange equation for a
Yang-Mills bar functional. We show the existence of a non-trivial solution of
this equation over compact K\"ahler manifolds as well as a short time existence
of the negative Yang-Mills bar gradient flow. We also show a rigidity of
holomorphic connections among a class of Yang-Mills bar connections over
compact K\"ahler manifolds of positive Ricci curvature.


title: Periods and elementary real numbers

abstract:
  The periods, introduced by Kontsevich and Zagier, form a class of complex
numbers which contains all algebraic numbers and several transcendental
quantities. Little has been known about qualitative properties of periods. In
this paper, we compare the periods with hierarchy of real numbers induced from
computational complexities. In particular we prove that periods can be
effectively approximated by elementary rational Cauchy sequences. As an
application, we exhibit a computable real number which is not a period.


title: Accuracy of the quantum adiabatic theorem in its original form

abstract:
  An explicit proof is developed to reinforce the accuracy of the quantum
adiabatic theorem in its original form without any inconsistency and/or
violation. Based on this proof, we discuss physical implications that give rise
to the violation of the quantum adiabatic approximation. We show that such a
violation can be obtained if and only if one violates the adiabatic criterion
itself or due to the existence of degeneracy at a later time. Subsequently,
comparison of our proof with respect to other recently developed proofs and
counter-examples are analyzed and discussed.


title: An accretion disc model for quasar optical variability

abstract:
  Some different correlations between optical-UV variability and other quasar
properties, such as luminosity, black hole mass and rest-frame wavelength, were
discovered. The positive correlation between optical-UV variability amplitude
and black hole mass was first found by Wold et al., and this was confirmed by
Wilhite et al. We suggest that the accretion disk model can explain these
correlations, provided the optical-UV variability is triggered by the change of
accretion rate. The disk temperature of accretion discs decreases with
increasing black hole mass, which leads to systematical spectral shape
difference with black hole mass even if the black hole is accreting at the same
rate m_dot (m_dot = M_dot / M_dotEdd). The observed positive correlation
between optical-UV variability and black hole mass can be well reproduced by
our model calculations, if the mean accretion rate m_dot0 ~ 0.1 with variation
of m_delta ~ 0.4 - 0.5 m_dot0. We also found that the observed correlations of
optical-UV variability amplitude with luminosity or rest-frame wavelength can
be qualitatively explained by this accretion disc model.


title:
Asymptotic enumeration of constellations and related families of maps on
  orientable surfaces

abstract:
  We perform the asymptotic enumeration of two classes of rooted maps on
orientable surfaces of genus g: m-hypermaps and m-constellations. For m=2, they
correspond respectively to maps with even face degrees and bipartite maps. We
obtain explicit asymptotic formulas for the number of such maps with any finite
set of allowed face degrees.
  Our proofs rely on the generalisation to orientable surfaces of the
Bouttier-Di Francesco-Guitter bijection, and on generating series methods. We
show that each of the 2g fondamental cycles of the surface contributes a factor
m between the numbers of m-hypermaps and m-constellations -- for example, large
maps of genus g with even face degrees are bipartite with probability tending
to 1/2^{2g}.
  A special case of our results implies former conjectures of Gao.


title: Equation of state for $\beta$-stable hot nuclear matter

abstract:
  We provide an equation of state for hot nuclear matter in $\beta$-equilibrium
by applying a momentum-dependent effective interaction. We focus on the study
of the equation of state of high-density and high-temperature nuclear matter,
containing leptons (electrons and muons) under the chemical equilibrium
condition in which neutrinos have left the system. The conditions of charge
neutrality and equilibrium under $\beta$-decay process lead first to the
evaluation of proton and lepton fractions and afterwards of internal energy,
free energy, pressure and in total to the equation of state of hot nuclear
matter. Thermal effects on the properties and equation of state of nuclear
matter are assesed and analyzed in the framework of the proposed effective
interaction model. Special attention is dedicated to the study of the
contribution of the components of $\beta$-stable nuclear matter to the entropy
per particle, a quantity of great interest for the study of structure and
collapse of supernova.


title: Probing extended Higgs sector through rare b --> s mu+ mu- transitions

abstract:
  We study the constraints on the contribution of new physics in the form of
scalar/pseudoscalar operators to the average forward backward asymmetry
<A_{FB}> of muons in B --> K mu+ mu- and the longitudinal polarization
asymmetry A_{LP} of muons in B_s --> mu+ mu-. We find that the maximum possible
value of <A_{FB}> allowed by the present upper bound on B(B_s --> mu+ mu-) is
about 1% at 95% C.L. and hence will be very difficult to measure. On the other
hand, the present bound on B(B_s --> mu+ mu-) fails to put any constraints on
A_{LP}, which can be as high as 100% even if B(B_s --> mu+ mu-) is close to its
standard model prediction. The measurement of A_{LP} will be a direct evidence
for an extended Higgs sector, and combined with the branching ratio B(B_s -->
mu+ mu-) it can even separate the new physics scalar and pseudoscalar
contributions.


title: Interpretation of high-pressure experiments on FeAs superconductors

abstract:
  In two recent articles (cond-mat/0606177 and arXiv:0804.1615), we have
suggested a unified theory of superconductivity based on the real-space
spin-parallel electron pairing and superconducting mechanism and have shown
that the stable hexagonal and tetragonal vortex lattices (the optimal doping
phases) can be expected in the newly discovered LaO{1-x}F{x}FeAs
(x0=1/7=0.1428) and SmO{1-x}F{x}FeAs (x0=1/6=0.1667), respectively. In this
paper, we present a theoretical study of the effects of hydrostatic and
anisotropic pressure on the superconducting transition temperature Tc of the
Fe-based layered superconductors based on the above mentioned theory. Our
results indicate a strong doping-dependent pressure effects on the Tc of this
compound system. Under high hydrostatic pressure, we find that dTc/dP is
negative when x>x0 (the so-called overdoped region) and is positive when x<x0
(the so-called underdoped region). Qualitatively, our finding is in good
agreement with the existing experimental data in LaO{1-x}F{x}FeAs (x=0.11<1/7)
(arXiv:0803.4266) and SmO{1-x}F{x}FeAs (x=0.13<1/6 and x=0.3>1/6)
(arXiv:0804.1582). Furthermore, Tc of both overdoped and underdoped samples
shows an increase with uniaxial pressure in the charge stripe direction and a
decrease with pressure in the direction perpendicular to the stripes. We
suggest that the mechanism responsible for the pressure effect is not specific
to the iron-based family and it may also be applicable to other superconducting
materials.


title:
Holonomy corrections to the cosmological primordial tensor power
  spectrum

abstract:
  Loop quantum gravity is one of the leading candidate theory to
non-perturbatively quantize gravity. In this framework, holonomy corrections to
the equation of propagation of gravitons in a FLRW background have been
derived. We investigate the consequences of those corrections on the tensor
power spectrum in de-Sitter and slow-roll inflations, for n=-1/2. Depending on
the value of the Barbero-Immirzi parameter, several observational features
could be expected.


title:
M\"obius transformations and the Poincar\'e distance in the quaternionic
  setting

abstract:
  In the space $\hh$ of quaternions, we investigate the natural, invariant
geometry of the open, unit disc $\Delta_{\hh}$ and of the open half-space
$\hh^{+}$. These two domains are diffeomorphic via a Cayley-type
transformation. We first study the geometrical structure of the groups of
M\"obius transformations of $\Delta_{\hh}$ and $\hh^{+}$ and identify original
ways of representing them in terms of two (isomorphic) groups of matrices with
quaternionic entries. We then define the cross-ratio of four quaternions, prove
that, when real, it is invariant under the action of the M\"obius
transformations, and use it to define the analogous of the Poincar\'e distances
on $\Delta_{\hh}$ and $\hh^{+}$. We easily deduce that there exists no isometry
between the quaternionic Poincar\'e distance of $\Delta_{\hh}$ and the
Kobayashi distance inherited by $\Delta_{\hh}$ as a domain of $\mathbb{C}^{2}$,
in accordance with a direct consequence of the classification of the non
compact, rank 1, symmetric spaces.


title: Dynamics of nonlinear resonances in Hamiltonian systems

abstract:
  It is well known that the dynamics of a Hamiltonian system depends crucially
on whether or not it possesses nonlinear resonances. In the generic case, the
set of nonlinear resonances consists of independent clusters of resonantly
interacting modes, described by a few low-dimensional dynamical systems. We
show that 1) most frequently met clusters are described by integrable dynamical
systems, and 2) construction of clusters can be used as the base for the
Clipping method, substantially more effective for these systems than the
Galerkin method. The results can be used directly for systems with cubic
Hamiltonian.


title:
Strong cleanness of the $2\times 2$ matrix ring over a general local
  ring

abstract:
  A ring $R$ is called strongly clean if every element of $R$ is the sum of a
unit and an idempotent that commute with each other. A recent result of
Borooah, Diesl and Dorsey \cite{BDD05a} completely characterized the
commutative local rings $R$ for which ${\mathbb M}_n(R)$ is strongly clean. For
a general local ring $R$ and $n>1$, however, it is unknown when the matrix ring
${\mathbb M}_n(R)$ is strongly clean. Here we completely determine the local
rings $R$ for which ${\mathbb M}_2(R)$ is strongly clean.


title: Prediction and Mitigation of Crush Conditions in Emergency Evacuations

abstract:
  Several simulation environments exist for the simulation of large-scale
evacuations of buildings, ships, or other enclosed spaces. These offer
sophisticated tools for the study of human behaviour, the recreation of
environmental factors such as fire or smoke, and the inclusion of architectural
or structural features, such as elevators, pillars and exits. Although such
simulation environments can provide insights into crowd behaviour, they lack
the ability to examine potentially dangerous forces building up within a crowd.
These are commonly referred to as crush conditions, and are a common cause of
death in emergency evacuations.
  In this paper, we describe a methodology for the prediction and mitigation of
crush conditions. The paper is organised as follows. We first establish the
need for such a model, defining the main factors that lead to crush conditions,
and describing several exemplar case studies. We then examine current methods
for studying crush, and describe their limitations. From this, we develop a
three-stage hybrid approach, using a combination of techniques. We conclude
with a brief discussion of the potential benefits of our approach.


title: Intrinsic room temperature ferromagnetism in Co-implanted ZnO

abstract:
  We report on the structural and magnetic properties of a cobalt-implanted ZnO
film grown on a sapphire substrate. X-ray diffraction and transmission electron
microscopy reveal the presence of a (10-10)-oriented hexagonal Co phase in the
Al2O3 sapphire substrate, but not in the ZnO film. Co clusters, with a diameter
of is about 5-6 nm, form a Co rich layer in the substrate close to the
ZnO/Al2O3 interface. Magnetization measurements indicate that there exist two
different magnetic phases in the implanted region. One originates from the Co
clusters in Al2O3, the other one belongs to a homogeneous ferromagnetic phase
with a ferromagnetic Curie temperature far above room temperature and can be
attributed to Co substitution on Zn sites in the ZnO layer. We have observed
magnetic dichroism at the Co L2,3 and O K edges at room temperature as well as
the multiplet structure in x-ray absorption spectra around the Co L3 edge,
supporting the intrinsic nature of the observed ferromagnetism in Co-implanted
ZnO film. The magnetic moment per substituted cobalt is found about 2.81 Bohr
magneton which is very close to the theoretical expected value of 3 Bohr
magneton per Co atom for Co 2+ in its high spin state.


title: Fluctuation relations without microreversibility in nonlinear transport

abstract:
  In linear transport, the fluctuation-dissipation theorem relates equilibrium
current correlations to the linear conductance coefficient. For nonlinear
transport, there exist fluctuation relations that rely on Onsager's principle
of microscopic reversibility away from equilibrium. However, both theory and
experiments have shown deviations from microreversibility in the form of
magnetic field asymmetric current-voltage relations. We present novel
fluctuation relations for nonlinear transport in the presence of magnetic
fields that relate current correlation functions at any order at equilibrium to
response coefficients of current cumulants of lower order. We illustrate our
results with the example of an electrical Mach-Zehnder interferometer.


title:
Binding Energies of the Alpha Particle and the A=3 Isobars from a
  Theoretical Geometric Model

abstract:
  We assume a triple geometric structure for the electromagnetic nuclear
interaction. This nuclear electromagnetism is used to calculate the binding
energies of the alpha particle and the A=3 isobar nuclides. The approximation
for the resultant wave equation which lead to the deuteron binding energy from
the modified Mathieu equation for the radial eigenvalue equation also
establishes proton-electron-proton magnetic bonds in these nuclides and
determines their binding energies. Completely theoretical calculations give
28.5 Mev., 7.64 Mev. and 8.42 Mev. for the binding energies of the alpha
particle, the helium 3 isotope and tritium respectively. These values admit
correction factors due to the approximations made.


title:
Charmed hadron production at low transverse momentum in Au+Au collisions
  at RHIC

abstract:
  We report measurements of charmed hadron production from hadronic
($D^{0}\rightarrow K\pi$) and semileptonic ($\mu$ and $e$) decays in 200 GeV
Au+Au collisions at RHIC. Analysis of the spectra indicates that charmed
hadrons have a different radial flow pattern from light or multi-strange
hadrons. Charm cross sections at mid-rapidity are extracted by combining the
three independent measurements, covering the transverse momentum range that
contributes to $\sim$90% of the integrated cross section. The cross sections
scale with number of binary collisions of the initial nucleons, a signature of
charm production exclusively at the initial impact of colliding heavy ions. The
implications for charm quark interaction and thermalization in the strongly
interacting matter are discussed.


title:
Fourier analyses of commensurability oscillations in Fibonacci lateral
  superlattices

abstract:
  Magnetotransport measurements have been performed on Fibonacci lateral
superlattices (FLSLs) -- two-dimensional electron gases subjected to a weak
potential modulation arranged in the Fibonacci sequence, LSLLSLS..., with
L/S=tau (the golden ratio). Complicated commensurability oscillation (CO) is
observed, which can be accounted for as a superposition of a series of COs each
arising from a sinusoidal modulation representing the characteristic length
scale of one of the self-similar generations in the Fibonacci sequence.
Individual CO components can be separated out from the magnetoresistance trace
by performing a numerical Fourier band-pass filter. From the analysis of the
amplitude of a single-component CO thus extracted, the magnitude of the
corresponding Fourier component in the potential modulation can be evaluated.
By examining all the Fourier contents observed in the magnetoresistance trace,
the profile of the modulated potential seen by the electrons can be
reconstructed with some remaining ambiguity about the interrelation of the
phase between different components.


title:
A General Variational Principle of Classical Field and Its Application
  to General relativity I

abstract:
  A general variational principle of classical fields with a Lagrangian
containing the field quantity and its derivatives of up to the N-th order is
presented. Noether's theorem is derived. The generalized Hamilton-Jacobi's
equation for the Hamilton's principal functional is obtained. These results are
surprisingly in great harmony with each other. They will be applied to the
general relativity in the subsequent articles, especially the generalized
Noether's theorem will be applied to the problem of conservation and
non-conservation in curved spacetime..


title: On Smarandache Bryant Schneider group of a Smarandache loop

abstract:
  The concept of Smarandache Bryant Schneider Group of a Smarandache loop is
introduced. Relationship(s) between the Bryant Schneider Group and the
Smarandache Bryant Schneider Group of an S-loop are discovered and the later is
found to be useful in finding Smarandache isotopy-isomorphy condition(s) in
S-loops just like the formal is useful in finding isotopy-isomorphy
condition(s) in loops. Some properties of the Bryant Schneider Group of a loop
are shown to be true for the Smarandache Bryant Schneider Group of a
Smarandache loop. Some interesting and useful cardinality formulas are also
established for a type of finite Smarandache loop.


title:
Topological methods in analysis of periodic and chaotic canard-type
  trajectories

abstract:
  We investigate the role of topological methods in the analysis of canard-type
periodic and chaotic trajectories. In the first part of the paper, we apply
topological degree to the analysis of multi-dimensional canards. The second
part is devoted to an application of a special corollary of the
Poincare-Bendixson theorem to the existence of periodic two-dimensional
canards.


title:
Chain Length Dependence on Folding Transition of a Semiflexible
  Homo-polymer Chain: Appearance of a Core-Shell Structure

abstract:
  The folding transition of single, long semiflexible polymers was studied with
special emphasis on the chain length effect using Monte Carlo simulations.
While a relatively short chain (10-25 Kuhn segments) undergoes a large discrete
transiton between swollen coil and compact toroid conformations, a long chain
(50 Kuhn segments) exhibits an intrachain segregated state between the
disordered coil and ordered toroid.


title:
Three-Dimensional Doppler Images of the Disk-like and Stream-like States
  of U Coronae Borealis

abstract:
  The 3D Radioastronomical Approach to Doppler tomography has been used to
study the H$\alpha$ emission sources in U Coronae Borealis. These 3D tomograms
provide greater resolution than the projected 2D version and highlight the
jet-like gas flows in the $V_z$ direction transverse to the orbital plane. In
this paper, the 3D tomograms are compared at two distinct epochs when U CrB was
in the disk-like state (1993 data) and the stream-like state (1994 data). Both
states display a prominent emission source, the circumprimary bulge, which is
produced when the gas stream strikes the photosphere of the mass-gainer. This
source is detected within $V_z$ = $\pm$150 km s{$^{-1}$}, and demonstrates that
the bulge is not confined to the orbital plane although it achieves maximum
strength near $V_z$=0 km s{$^{-1}$}. Other emission sources include the
stream-star and stream-disk shocks and a Localized Region (LR) where the
circling disk material strikes the incoming gas stream. The LR has $V_z$
velocities of 200 to 500 km s{$^{-1}$} in the disk-like state. The disk
emission is seen over a range of $V_z$ velocities, and there is evidence that
the disk is inclined to the orbital plane or may have two arms. The gas stream
flows along its predicted trajectory in the stream-like state, and a comparison
with the disk-like state suggests that the gas stream has a higher density than
the disk in both states of this binary.


title: Constraints on unparticle physics from the $gt\bar t$ anomalous coupling

abstract:
  We study the impact of unparticle physics to the chromomagnetic dipole moment
(CMDM) of the top quark. We compute the effect induced by unparticle operators
of scalar and vector nature coupled to fermions on the CMDM. We find that this
dipole moment is sensitive to the scale dimensions $d_u$ of the unparticle and
the new couplings of the respective effective operators. Using the bounds
imposed on the CMDM by low-energy precision and Tevatron measurements we derive
indirect limits on the unparticle parameter space. In particular, we find that
the scalar-unparticle operator contribution fulfills both constraints for most
of the unparticle parameter space, while the low-energy precision bound on the
CMDM excludes a vector-unparticle contribution for low values of respective
scale dimension $d_u$.


title:
Elliptic Curves, Algebraic Geometry Approach in Gravity Theory and
  Uniformization of Multivariable Cubic Algebraic Equations

abstract:
  Based on the distinction between the covariant and contravariant metric
tensor components in the framework of the affine geometry approach and the s.c.
"gravitational theories with covariant and contravariant connection and
metrics", it is shown that a wide variety of third, fourth, fifth, seventh,
tenth- degree algebraic equations exists in gravity theory. This is important
in view of finding new solutions of the Einstein's equations, if they are
treated as algebraic ones. Since the obtained cubic algebraic equations are
multivariable, the standard algebraic geometry approach for parametrization of
two-dimensional cubic equations with the elliptic Weierstrass function cannot
be applied. Nevertheless, for a previously considered cubic equation for
reparametrization invariance of the gravitational Lagrangian and on the base of
a newly introduced notion of "embedded sequence of cubic algebraic equations",
it is demonstrated that in the multivariable case such a parametrization is
also possible, but with complicated irrational and non-elliptic functions.
After finding the solutions of a system of first - order nonlinear differential
equations, these parametrization functions can be considered also as
uniformization ones (depending only on the complex uniformization variable z)
for the initial multivariable cubic equation.


title:
The semiclassical small-$\hbar$ limit of loci of roots of fundamental
  solutions for polynomial potentials

abstract:
  In this paper a description of the small-$\hbar$ limit of loci of zeros of
fundamental solutions for polynomial potentials is given. The considered cases
of the potentials are bounded to the ones which provided us with simple turning
points only. Among the latter potentials still several cases of Stokes graphs
the potentials provide us with are distinguished, i.e. the general non-critical
Stokes graphs, the general critical ones but with only single internal Stokes
line and the Stokes graphs corresponding to arbitrary multiple-well real even
degree polynomial potentials with internal Stokes lines distributed on the real
axis only. All these cases are considered in their both versions of the
quantized and not quantized $\hbar$. In particular due to the fact that the
small-$\hbar$ limit is semiclassical it is shown that loci of roots of
fundamental solutions in the cases considered are collected along Stokes lines.
There are infinitely many roots of fundamental solutions on such lines escaping
to infinity and a finite number of them on internal Stokes lines.


title: A Limit Theorem for Products of Free Unitary Operators

abstract:
  This paper establishes necessary and sufficient conditions for the products
of freely independent unitary operators to converge in distribution to the
uniform law on the unit circle.


title:
Wireless Secrecy in Cellular Systems with Infrastructure--Aided
  Cooperation

abstract:
  In cellular systems, confidentiality of uplink transmission with respect to
eavesdropping terminals can be ensured by creating intentional inteference via
scheduling of concurrent downlink transmissions. In this paper, this basic idea
is explored from an information-theoretic standpoint by focusing on a two-cell
scenario where the involved base stations are connected via a finite-capacity
backbone link. A number of transmission strategies are considered that aim at
improving uplink confidentiality under constraints on the downlink rate that
acts as an interfering signal. The strategies differ mainly in the way the
backbone link is exploited by the cooperating downlink- to the uplink-operated
base stations. Achievable rates are derived for both the Gaussian (unfaded) and
the fading cases, under different assumptions on the channel state information
available at different nodes. Numerical results are also provided to
corroborate the analysis. Overall, the analysis reveals that a combination of
scheduling and base station cooperation is a promising means to improve
transmission confidentiality in cellular systems.


title:
Observational Biases Masquerading as Cosmological Effects? A Cautionary
  Tale about Blue Tilts and Other Trends in Globular Cluster Systems

abstract:
  The high spatial resolution of the Hubble Space Telescope (HST) has led to
tremendous progress in many areas of astronomy. The ability of the HST to peer
into the bright inner regions of galaxies and distinguish between globular
clusters (GCs) and background objects has been particularly beneficial to the
study of clusters. But the very virtue of the HST that has been an asset to
such research can be its pitfall if the consequences of superior angular
resolution are not considered in detail. Recent HST studies show a small, but
consistent, color-magnitude correlation in the metal-poor halo GCs of nearby
galaxies. This `blue-tilt' has been interpreted as a mass-metallicity
relationship, implying self-enrichment in the higher mass GCs. We show that the
`blue-tilt' is likely the consequence of a small, but measurable with HST,
mass-size relationship in GCs. The combined effects of Poisson noise and
surface brightness fluctuations can explain other apparent correlations of the
`blue-tilt' with environment. Some HST based studies have similarly suggested
that the mean metallicity of the blue, metal-poor, halo clusters increases with
host galaxy mass, indicating that GC metallicity is linked to the size of the
host galaxy halo. We show that this correlation is also likely due to the
effects of GC size in high resolution HST images. We also point out that the
presumed fundamental plane of GCs itself varies with galactocentric distance
due to GC size trends and ultra compact dwarfs may simply reflect the tail of
the globular cluster distribution.


title:
Measuring the cosmological parameters with the Ep,i-Eiso correlation of
  Gamma-Ray Bursts

abstract:
  We have used the Ep,i-Eiso correlation of GRBs to measure the cosmological
parameter Omega_M. By adopting a maximum likelihood approach which allows us to
correctly quantify the extrinsic (i.e. non--Poissonian) scatter of the
correlation, we constrain (for a flat universe) Omega_M to 0.04-0.40 (68%
confidence level), with a best fit value of Omega_M ~ 0.15, and exclude Omega_M
= 1 at 99.9% confidence level. If we release the assumption of a flat universe,
we still find evidence for a low value of Omega_M (0.04-0.50 at 68% confidence
level) and a weak dependence of the dispersion of the Ep,i-Eiso correlation on
Omega_Lambda (with an upper limit of Omega_Lambda ~ 1.15 at 90% confidence
level). Our approach makes no assumptions on the Ep,i-Eiso correlation and it
does not use other calibrators to set the "zero' point of the relation,
therefore our treatment of the data is not affected by circularity and the
results are independent of those derived via type Ia SNe (or other cosmological
probes). Unlike other multi-parameters correlations, our analysis grounds on
only two parameters, then including a larger number (a factor ~3) of GRBs and
being less affected by systematics. Simulations based on realistic
extrapolations of ongoing (and future) GRB experiments (e.g., Swift,
Konus-Wind, GLAST) show that: i) the uncertainties on cosmological parameters
can be significantly decreased; ii) future data will allow us to get clues on
the "dark energy" evolution.


title:
Kramers degeneracy in a magnetic field and Zeeman spin-orbit coupling in
  antiferromagnetic conductors

abstract:
  In this article, I study magnetic response of electron wavefunctions in a
commensurate collinear antiferromagnet. I show that, at a special set of
momenta, hidden anti-unitary symmetry protects Kramers degeneracy of Bloch
eigenstates against a magnetic field, pointing transversely to staggered
magnetization. Hence a substantial momentum dependence of the transverse
g-factor in the Zeeman term, turning the latter into a spin-orbit coupling,
that may be present in materials from chromium to borocarbides, cuprates,
pnictides, as well as organic and heavy fermion conductors.


title: Non-Involutive Constrained Systems and Hamilton-Jacobi Formalism

abstract:
  In this work we discuss the natural appearance of the Generalized Brackets in
systems with non-involutive (equivalent to second class) constraints in the
Hamilton-Jacobi formalism. We show how a consistent geometric interpretation of
the integrability conditions leads to the reduction of degrees of freedom of
these systems and, as consequence, naturally defines a dynamics in a reduced
phase space.


title: Hydrodynamic limit for a zero-range process in the Sierpinski gasket

abstract:
  We prove that the hydrodynamic limit of a zero-range process evolving in
graphs approximating the Sierpinski gasket is given by a nonlinear heat
equation. We also prove existence and uniqueness of the hydrodynamic equation
by considering a finite-difference scheme.


title:
A Novel Approach for Lattice Simulations of Polymer Chains in Dense
  Amorphous Polymer Systems: Method Development and Validation with 2-D
  Lattices

abstract:
  We present here the systematic development of quantitative lattice
simulations of dense polymers through a novel computational technique that
allows for an efficient accounting of the chain conformations. Our approach is
based on the decomposition of the original lattice into sublattices of optimal
size. We develop and validate the method here for 2-D lattices using
sublattices of 4x4 nodes. For each possible connectivity, i.e. arrangement of
bonds connecting the 4x4 nodes of a sublattice with the rest of the nodes of
the lattice, all possible sublattice microstates (submicrostates) are
evaluated. We apply this technique to study the interlamellar amorphous phase
in dense semicrystalline polymers where in polymer chains conform to a 2-D
square lattice. For lattices of moderate size (up to 8x8 nodes), exact results
can be obtained from an exhaustive enumeration of all the microstates
corresponding to the fully dense (i.e. with no free chain ends) interlamellar
amorphous phase of a semicrystalline system. For larger lattices, a stochastic
enumeration technique (purely entropic) and an efficient Metropolis Monte Carlo
scheme were developed. A large selection of Monte Carlo moves makes the
correlation between the Monte Carlo moves especially short. Thus, statistical
quantities of interest can be obtained with tight error bars (calculated
concurrently with the averages) using small number of steps.


title:
Quantitative Lattice Simulations of the Dense Amorphous Phase in
  Semicrystalline Polymers : Size and Energy Effects in 2-D Lattices

abstract:
  In this work we illustrate our novel quantitative simulation approach for
dense amorphous polymer systems, as discussed in our previous work[Kulkarni et
al., A Novel Approach for Lattice Simulations of Polymer Chains in Dense
Amorphous Polymer Systems: Method Development and Validation with 2-D Lattices,
arXiV, 2008] in applications involving large lattice sizes and high energetic
bias. We first demonstrate how the topology of the microstate ensemble in 2-D
lattices presents a serious challenge for the collection of accurate and
reliable quantitative results (i.e., with simultaneous determination of error
bars) for large lattices. This necessitates a further enhancement of our Monte
Carlo simulation scheme to sample effectively a meaningful 2-D lattice
configurational subspace. Two techniques were investigated: simulated annealing
and parallel tempering, to avoid trapping near a local free energy minimum in
simulations at high energetic bias. Extensive results of the prediction of
various chain conformation statistics and thermodynamic quantities, in the
thermodynamic limit (i.e. infinite lateral sizes) are presented.


title: Alternatives to Pearson's and Spearman's Correlation Coefficients

abstract:
  This article presents several alternatives to Pearson's correlation
coefficient and many examples. In the samples where the rank in a discrete
variable counts more than the variable values, the mixtures that we propose of
Pearson's and Spearman's correlation coefficients give better results.


title:
Localized nonlinear waves in systems with time- and space-modulated
  nonlinearities

abstract:
  Using similarity transformations we construct explicit nontrivial solutions
of nonlinear Schr\"odinger equations with potentials and nonlinearities
depending on time and on the spatial coordinates. We present the general theory
and use it to calculate explicitly non-trivial solutions such as periodic
(breathers), resonant or quasiperiodically oscillating solitons. Some
implications to the field of matter-waves are also discussed.


title:
Fast partons as a source of energy and momentum in a perturbative
  quark-gluon plasma

abstract:
  I derive the space-time distribution of energy and momentum deposited by a
fast parton traversing a perturbative quark-gluon plasma by considering the
fast parton as the source of an external color field interacting with the
medium. I include the medium's response to screen the fast parton's color field
by incorporating dielectric functions and compare to the unscreened result.


title: Disk Dispersal and Planet Formation Time Scales

abstract:
  Well before the existence of exo-solar systems was confirmed, it was accepted
knowledge that most -- if not all -- stars possess circumstellar material
during the first one-to-several million years of their pre-main sequence lives,
and thus that they commonly have the potential to form planets. Here I
summarize current understanding regarding the evolution of proto-planetary dust
and gas disks, emphasizing the diversity in evolutionary paths.


title:
Using Linear Programming to Construct Better Criteria for Closing the
  Detection Loophole in Epr Experiments

abstract:
  I formulate the problem of closing the detection loophole as a constrained
optimization problem. Numerical methods can then be used to maximize the
detector efficiency subject to the constraint that there exists a local realist
explanation for the quantum correlations observed in the EPR experiment in
question. Any detector efficiency larger than this maximum rules out all local
realist explanations, and hence closes the detection loophole.


title: Classical Worldsheets for String Scattering on Flat and AdS Spacetime

abstract:
  We present a study of the worldsheets that describe the classical limit of
various string scattering processes. Our main focus is on string scattering in
AdS spacetime because of its relation via the AdS/CFT correspondence to gluon
scattering in {\cal N}=4 supersymmetric Yang-Mills theory. But we also consider
analogous processes in flat Minkowski spacetime which we compare to the AdS
case. In addition to scattering of string by string we also find and study
worldsheets describing the scattering of a string by external sources.


title:
Algorithms for Probabilistically-Constrained Models of Risk-Averse
  Stochastic Optimization with Black-Box Distributions

abstract:
  We consider various stochastic models that incorporate the notion of
risk-averseness into the standard 2-stage recourse model, and develop novel
techniques for solving the algorithmic problems arising in these models. A key
notable feature of our work that distinguishes it from work in some other
related models, such as the (standard) budget model and the (demand-) robust
model, is that we obtain results in the black-box setting, that is, where one
is given only sampling access to the underlying distribution. Our first model,
which we call the risk-averse budget model, incorporates the notion of
risk-averseness via a probabilistic constraint that restricts the probability
(according to the underlying distribution) with which the second-stage cost may
exceed a given budget B to at most a given input threshold \rho. We also a
consider a closely-related model that we call the risk-averse robust model,
where we seek to minimize the first-stage cost and the (1-\rho)-quantile of the
second-stage cost.
  We obtain approximation algorithms for a variety of combinatorial
optimization problems including the set cover, vertex cover, multicut on trees,
min cut, and facility location problems, in the risk-averse budget and robust
models with black-box distributions. We obtain near-optimal solutions that
preserve the budget approximately and incur a small blow-up of the probability
threshold (both of which are unavoidable). To the best of our knowledge, these
are the first approximation results for problems involving probabilistic
constraints and black-box distributions. A major component of our results is a
fully polynomial approximation scheme for solving the LP-relaxation of the
risk-averse problem.


title: What drives mesoscale atmospheric turbulence?

abstract:
  Measurements of atmospheric winds in the mesoscale range (10-500 km) reveal
remarkably universal spectra with the $k^{-5/3}$ power law. Despite initial
expectations of the inverse energy cascade, as in two-dimensional (2D)
turbulence, measurements of the third velocity moment in atmosphere, suggested
a direct energy cascade. Here we propose a possible solution to this
controversy by accounting for the presence of a large-scale coherent flow, or a
spectral condensate. We present new experimental laboratory data and show that
the presence of a large-scale shear flow modifies the third-order velocity
moment in spectrally condensed 2D turbulence, making it, in some conditions,
similar to that observed in the atmosphere.


title:
Density Matrix Equation for a Bathed Small System and its Application to
  Molecular Magnets

abstract:
  The technique of density matrix equation (DME) for a small system interacting
with a bath is explained in detail. Special attention is given to the
nonsecular DME that is needed in the vicinity of overdamped tunnelling
resonances in molecular magnets (MM). The relaxation terms of the DME for MM
are represented in the universal form that does not employ any unknown
spin-lattice coupling constants and absorbs the information about the spin
Hamiltonian in the exact basis states and transition frequencies. This makes
adding new types of anisotropy easy and error-free. The Mathematica code is
available from the author.


title: Freiman-Ruzsa-type theory for small doubling constant

abstract:
  In this paper, we study the linear structure of sets $A \subset
\mathbb{F}_2^n$ with doubling constant $\sigma(A)<2$, where
$\sigma(A):=\frac{|A+A|}{|A|}$. In particular, we show that $A$ is contained in
a small affine subspace. We also show that $A$ can be covered by at most four
shifts of some subspace $V$ with $|V|\leq |A|$. Finally, we classify all binary
sets with small doubling constant.


title: Tri-crystal fixed exit monochromator

abstract:
  It is proposed a novel design of an X-ray monochromator which uses three
crystals. The exit beam turns in horizontal plane on the angle $2\alpha$ with
respect to the incoming beam. So, this kind of monochromator is suitable for
side beam-lines; several tunable beam-lines can be built for a one fan beam of
synchrotron radiation (from wiggler or bending magnet).
  In contrast to the double-crystal scheme of general position considered
previously (which also suitable for side beam-lines), the new variant does not
lead to a tilt of exit beam profile.


title: Gr\"unbaum Colorings of Toroidal Triangulations

abstract:
  We prove that if G is a triangulation of the torus and \chi(G) \neq 5, then
there is a 3-coloring of the edges of G so that the edges bounding every face
are assigned three different colors.


title:
Atomic data and electron-impact broadening effect in DO white dwarf
  atmospheres: Si VI

abstract:
  Energy levels, electric dipole transition probabilities and oscillator
strengths in five times ionized silicon have been calculated in intermediate
coupling. The present calculations were carried out with the general purpose
atomic-structure program SUPERSTRUCTURE. The relativistic corrections to the
non-relativistic Hamiltonian are taken into account through the Breit-Pauli
approximation. We have also introduced a semi-empirical correction (TEC) for
the calculation of the energy-levels. These atomic data are used to provide
semiclassical electron-, proton- and ionized helium- impact line widths and
shifts for 15 Si VI muliplet. Calculated results have been used to consider the
influence of Stark broadening for DO white dwarf atmospheric conditions.


title: Representation Growth of Linear Groups

abstract:
  Let $\Gamma$ be a group and $r_n(\Gamma)$ the number of its $n$-dimensional
irreducible complex representations. We define and study the associated
representation zeta function $\calz_\Gamma(s) = \suml^\infty_{n=1}
r_n(\Gamma)n^{-s}$. When $\Gamma$ is an arithmetic group satisfying the
congruence subgroup property then $\calz_\Gamma(s)$ has an ``Euler
factorization". The "factor at infinity" is sometimes called the "Witten zeta
function" counting the rational representations of an algebraic group. For
these we determine precisely the abscissa of convergence. The local factor at a
finite place counts the finite representations of suitable open subgroups $U$
of the associated simple group $G$ over the associated local field $K$. Here we
show a surprising dichotomy: if $G(K)$ is compact (i.e. $G$ anisotropic over
$K$) the abscissa of convergence goes to 0 when $\dim G$ goes to infinity, but
for isotropic groups it is bounded away from 0. As a consequence, there is an
unconditional positive lower bound for the abscissa for arbitrary finitely
generated linear groups. We end with some observations and conjectures
regarding the global abscissa.


title:
Electron energy-loss spectroscopy and ab initio electronic structure of
  the LaOFeP superconductor

abstract:
  The electronic band structures of the LaOFeP superconductor have been
calculated theoretically by the first principles method and measured
experimentally by electron energy loss spectroscopy. The calculations indicate
that the Fe atom in LaOFeP crystal shows a weak magnetic moment and does not
form a long-range magnetic ordering. Band structure, Fermi surfaces and
fluorine-doping effects are also analyzed based on the data of the density
functional theory. The fine structures of the EELS data have been carefully
examined in both the low loss energy region and the core losses region (O K, Fe
L2,3, and La M4,5). A slight bump edge at 44 eV shows notable
orientation-dependence: it can be observed in the low loss EELS spectra with q
parallel to c, but becomes almost invisible in the q vertical to c spectra.
Annealing experiments indicate that low oxygen pressure favors the appearance
of superconductivity in LaOFeP, this fact is also confirmed by the changes of
Fe L2,3 and O K excitation edges in the experimental EELS data.


title: Hypernucleus Production by $A(p,pK^+)_{\Lambda}B$ Reactions

abstract:
  The $\Lambda$-hypernucleus production by $A(p, pK^+)_{\Lambda}B$ reactions is
investigated within the framework of the distorted wave impulse
approximation(DWIA). The amplitude for the elementary process is evaluated in a
fully covariant two-nucleon model based on the effective Lagrangian. The
reaction cross sections for $\Lambda$-hypernucleus productions on $^6Li$,
$^{12}C$ and $^{16}O$ targets are calculated. It is found that the distortion
effects tend to reduce the cross sections by a factor of 3$\sim$10. Various
differential cross sections (DCS) and double differential cross sections (DDCS)
are presented. It is shown that for the $s_{\Lambda}-$wave hypernucleus
production, the DCS is decreased with increasing nuclear mass, and the DCS for
the $p_{\Lambda}-$wave hypernucleus production is normally higher than that for
the $s_{\Lambda}-$wave hypernucleus production. As a reference, the DDCS with
respect to the momenta of the outgoing proton and kaon is also demonstrated.
Finally, the missing mass spectra of the inclusive reaction $p+A\to p+ K^+ + X$
for $^6Li$, $^{12}C$ and $^{16}O$ targets are presented, from which the masses
of hypernuclei can accurately be extracted. Thus, we conclude that the missing
mass spectrum method is an alternative to study hypernuclear physics. And the
study of hypernuclear physics can be carried out in COSY and CSR by the
$A(p,pK^+)_{\Lambda}B$ reaction due to the $\mu$b-order reaction cross
sections.


title:
On absolute continuity of the spectrum of a d-dimensional periodic
  magnetic Dirac operator

abstract:
  In this paper, for d > 2, we prove the absolute continuity of the spectrum of
a d-dimensional periodic Dirac operator with some discontinuous magnetic and
electric potentials. In particular, for d = 3, electric potentials from Zygmund
classes $L^3\ln ^{1+\delta}L(K)$, $\delta >0$, and also ones with Coulomb
singularities, with constraints on charges depending on the magnetic potential,
are admitted (here K is the fundamental domain of the period lattice).


title: The Player's Effect

abstract:
  In a function that takes its inputs from various players, the effect of a
player measures the variation he can cause in the expectation of that function.
In this paper we prove a tight upper bound on the number of players with large
effect, a bound that holds even when the players' inputs are only known to be
pairwise independent. We also study the effect of a set of players, and show
that there always exists a "small" set that, when eliminated, leaves every set
with little effect. Finally, we ask whether there always exists a player with
positive effect. We answer this question differently in various scenarios,
depending on the properties of the function and the distribution of players'
inputs. More specifically, we show that if the function is non-monotone or the
distribution is only known to be pairwise independent, then it is possible that
all players have 0 effect. If the distribution is pairwise independent with
minimal support, on the other hand, then there must exist a player with "large"
effect.


title:
The Dark Matter Constraints on the Left-Right Symmetric Model with Z_2
  Symmetry

abstract:
  In the framework of Left-Right symmetric model, we investigate an interesting
scenario, in which the so-called VEV seesaw problem can be naturally solved
with Z_2 symmetry. In such a scenario, we find a pair of stable weakly
interacting massive particles (WIMPs), which may be the cold dark matter
candidates. However, the WIMP-nucleon cross section is 3-5 orders of magnitude
above the present upper bounds from the direct dark matter detection
experiments for $m \sim 10^2-10^4 $ GeV. As a result, the relic number density
of two stable particles has to be strongly suppressed to a very small level.
Nevertheless, our analysis shows that this scenario can't provide very large
annihilation cross sections so as to give the desired relic abundance except
for the resonance case. Only for the case if the rotation curves of disk
galaxies are explained by the Modified Newtonian Dynamics (MOND), the stable
WIMPs could be as the candidates of cold dark matter.


title:
Universal and non-universal tails of distribution functions in the
  directed polymer and KPZ problems

abstract:
  The optimal fluctuation approach is applied to study the most distant
(non-universal) tails of the free-energy distribution function P(F) for an
elastic string (of a large but finite length L) interacting with a quenched
random potential. A further modification of this approach is proposed which
takes into account the renormalization effects and allows one to study the most
close (universal) parts of the tails. The problem is analyzed for different
dimensions of a space in which the polymer is imbedded. In terms the stochastic
growth problem, the same distribution function describes the distribution of
heights in the regime of a non-stationary growth in a situation when an
interface starts to grow from a flat configuration.


title: Some Lagrangians with Zeta Function Nonlocality

abstract:
  Some nonlocal and nonpolynomial scalar field models originated from p-adic
string theory are considered. Infinite number of spacetime derivatives is
governed by the Riemann zeta function through d'Alembertian $\Box$ in its
argument. Construction of the corresponding Lagrangians begins with the exact
Lagrangian for effective field of p-adic tachyon string, which is generalized
replacing p by arbitrary natural number n and then taken a sum of over all n.
Some basic classical field properties of these scalar fields are obtained. In
particular, some trivial solutions of the equations of motion and their tachyon
spectra are presented. Field theory with Riemann zeta function nonlocality is
also interesting in its own right.


title:
Controlled generation of coherent matter-currents using a periodic
  driving field

abstract:
  We study the effect of a strong, oscillating driving field on the dynamics of
ultracold bosons held in an optical lattice. Modeling the system as a
Bose-Hubbard model, we show how the driving field can be used to produce and
maintain a coherent atomic current by controlling the phase of the intersite
tunneling processes. We investigate both the stroboscopic and time-averaged
behavior using Floquet theory, and demonstrate that this procedure provides a
stable and precise method of controlling coherent quantum systems.


title:
Enhancement of the superconducting transition temperature in
  La2-xSrxCuO4 bilayers: Role of pairing and phase stiffness

abstract:
  The superconducting transition temperature, Tc, of bilayers comprising
underdoped La2-xSrxCuO4 films capped by a thin heavily overdoped metallic
La1.65Sr0.35CuO4 layer, is found to increase with respect to Tc of the bare
underdoped films. The highest Tc is achieved for x = 0.12, close to the
'anomalous' 1/8 doping level, and exceeds that of the optimally-doped bare
film. Our data suggest that the enhanced superconductivity is confined to the
interface between the layers. We attribute the effect to a combination of the
high pairing scale in the underdoped layer with an enhanced phase stiffness
induced by the overdoped film.


title:
Scaling theory for diffusion limited cluster aggregation in a porous
  medium

abstract:
  A scaling theory is developed for diffusion-limited cluster aggregation in a
porous medium, where the primary particles and clusters stick irreversibly to
the walls of the pore space as well as to each other. Three scaling regimes are
predicted, connected by smooth crossovers. The first regime is at low primary
particle concentrations where the primary particles stick individually to the
walls. The second regime is at intermediate concentrations where clusters grow
to a certain size, smaller than the pore size, then stick individually to the
walls. The third regime is at high concentrations where the final state is a
pore-space-filling network.


title:
Freezing and extreme value statistics in a Random Energy Model with
  logarithmically correlated potential

abstract:
  We investigate some implications of the freezing scenario proposed by
Carpentier and Le Doussal (CLD) for a random energy model (REM) with
logarithmically correlated random potential. We introduce a particular
(circular) variant of the model, and show that the integer moments of the
partition function in the high-temperature phase are given by the well-known
Dyson Coulomb gas integrals. The CLD freezing scenario allows one to use those
moments for extracting the distribution of the free energy in both high- and
low-temperature phases. In particular, it yields the full distribution of the
minimal value in the potential sequence. This provides an explicit new class of
extreme-value statistics for strongly correlated variables, manifestly
different from the standard Gumbel class.
  -

categories: cond-mat.dis-nn cond-mat.stat-mech math-ph math.MP


title:
Modeling of optical, transport, and thermodynamic properties of Al metal
  irradiated by intense femtosecond laser pulses

abstract:
  A theoretical model is developed for the interaction of intense femtosecond
laser pulses with solid targets on the basis of the two-temperature equation of
state for an irradiated substance. It allows the description of the dynamics of
the plasma formation and expansion. Comparison of available experimental data
on the amplitude and phase of the complex reflection coefficient of aluminum
with the simulation results provides new information on the transport
coefficients and absorption capacity of the strongly coupled Al plasma over a
wide range of temperatures and pressures.


title:
Gaussian wave packet solution of the Schrodinger equation in the
  presence of a time-dependent linear potential

abstract:
  We argue that the way to get the general solution of a Schrodinger equation
in the presence of a time-dependent linear potential based on the
Lewis-Riesenfeld framework is to use a Hermitian linear invariant operator. We
demonstrate that the linear invariant proposed in p and q is an Hermitian
operator which has the Gaussian wave packet as its eigenfunction.


title: Collinear triples in permutations

abstract:
  Let $\alpha:\mathbb{F}_q\to\mathbb{F}_q$ be a permutation and $\Psi(\alpha)$
be the number of collinear triples in the graph of $\alpha$, where
$\mathbb{F}_q$ denotes a finite field of $q$ elements. When $q$ is odd Cooper
and Solymosi once proved $\Psi(\alpha)\geq(q-1)/4$ and conjectured the sharp
bound should be $\Psi(\alpha)\geq(q-1)/2$. In this note we indicate that the
Cooper-Solymosi conjecture is true.


title: The near neutrino detector for the T2K experiment

abstract:
  The T2K experiment is a second generation long baseline neutrino oscillation
experiment designed as a sensitive search for nu_e appearance. The T2K near
neutrino detector complex is located 280 meters from the pion production target
and will measure both neutrino beam properties close to the production point
and interaction cross sections. The main design features, test results and
status of these detectors are presented.


title: Fast dynamos in weakly ionized gases

abstract:
  The turnover of interstellar gas on $\sim 10^9$yr timescales argues for the
continuous operation of a galactic dynamo. The conductivity of interstellar gas
is so high that the dynamo must be "fast" - i.e. the magnetic field must be
amplified at a rate nearly independent of the magnetic diffusivity. Yet, all
the fast dynamos so far known - and all direct numerical simulations of
interstellar dynamos - yield magnetic power spectra that peak at the resistive
scale, while galactic magnetic fields have substantial power on large scales.
In this paper we show that in weakly ionized gas the limiting scale may be the
ion-neutral decoupling scale, which although still small is many orders of
magnitude larger than the resistive scale.