title: Coevolution of teaching activity promotes cooperation

abstract:
  Evolutionary games are studied where the teaching activity of players can
evolve in time. Initially all players following either the cooperative or
defecting strategy are distributed on a square lattice. The rate of strategy
adoption is determined by the payoff difference and a teaching activity
characterizing the donor's capability to enforce its strategy on the opponent.
Each successful strategy adoption process is accompanied with an increase in
the donor's teaching activity. By applying an optimum value of the increment
this simple mechanism spontaneously creates relevant inhomogeneities in the
teaching activities that support the maintenance of cooperation for both the
prisoner's dilemma and the snowdrift game.


title: Analysis of boosting algorithms using the smooth margin function

abstract:
  We introduce a useful tool for analyzing boosting algorithms called the
``smooth margin function,'' a differentiable approximation of the usual margin
for boosting algorithms. We present two boosting algorithms based on this
smooth margin, ``coordinate ascent boosting'' and ``approximate coordinate
ascent boosting,'' which are similar to Freund and Schapire's AdaBoost
algorithm and Breiman's arc-gv algorithm. We give convergence rates to the
maximum margin solution for both of our algorithms and for arc-gv. We then
study AdaBoost's convergence properties using the smooth margin function. We
precisely bound the margin attained by AdaBoost when the edges of the weak
classifiers fall within a specified range. This shows that a previous bound
proved by R\"{a}tsch and Warmuth is exactly tight. Furthermore, we use the
smooth margin to capture explicit properties of AdaBoost in cases where cyclic
behavior occurs.


title: Electrodynamic spherical harmonic

abstract:
  Electrodynamic spherical harmonic is a second rank tensor in
three-dimensional space. It allows to separate the radial and angle variables
in vector solutions of Maxwell's equations. Using the orthonormalization for
electrodynamic spherical harmonic, a boundary problem on a sphere can be easily
solved.


title:
Search for a stochastic background of 100-MHz gravitational waves with
  laser interferometers

abstract:
  This letter reports the results of a search for a stochastic background of
gravitational waves (GW) at 100 MHz by laser interferometry. We have developed
a GW detector, which is a pair of 75-cm baseline synchronous recycling
(resonant recycling) interferometers. Each interferometer has a strain
sensitivity of ~ 10^{-16} Hz^{-1/2} at 100 MHz. By cross-correlating the
outputs of the two interferometers within 1000 seconds, we found h_{100}^2
Omega_{gw} < 6 times 10^{25} to be an upper limit on the energy density
spectrum of the GW background in a 2-kHz bandwidth around 100 MHz, where a flat
spectrum is assumed.


title: K-stability of constant scalar curvature K\"ahler manifolds

abstract:
  We show that a polarised manifold with a constant scalar curvature K\"ahler
metric and discrete automorphisms is K-stable. This refines the K-semistability
proved by S. K. Donaldson.


title:
On the number of $k$-cycles in the assignment problem for random
  matrices

abstract:
  We continue the study of the assignment problem for a random cost matrix. We
analyse the number of $k$-cycles for the solution and their dependence on the
symmetry of the random matrix. We observe that for a symmetric matrix one and
two-cycles are dominant in the optimal solution. In the antisymmetric case the
situation is the opposite and the one and two-cycles are suppressed. We solve
the model for a pure random matrix (without correlations between its entries)
and give analytic arguments to explain the numerical results in the symmetric
and antisymmetric case. We show that the results can be explained to great
accuracy by a simple ansatz that connects the expected number of $k$-cycles to
that of one and two cycles.


title:
Detecting gravitational wave emission from the known accreting neutron
  stars

abstract:
  Detection of gravitational waves from accreting neutron stars (NSs) in our
galaxy, due to ellipticity or internal oscillation, would be a breakthrough in
our understanding of compact objects and explain the absence of NSs rotating
near the break-up limit. Direct detection, however, poses a formidable
challenge. Using the current data available on the properties of the accreting
NSs in Low Mass X-Ray Binaries (LMXBs), we quantify the detectability for the
known accreting NSs, considering various emission scenarios and taking into
account the negative impact of parameter uncertainty on the data analysis
process. Only a few of the persistently bright NSs accreting at rates near the
Eddington limit are detectable by Advanced LIGO if they are emitting
gravitational waves at a rate matching the torque from accretion. A larger
fraction of the known population is detectable if the spin and orbital
parameters are known in advance, especially with the narrow-band Advanced LIGO.
We identify the most promising targets, and list specific actions that would
lead to significant improvements in detection probability. These include
astronomical observations (especially for unknown orbital periods),
improvements in data analysis algorithms and capabilities, and further detector
development.


title:
Brill-Noether theory of curves on Enriques surfaces I: the positive cone
  and gonality

abstract:
  We study the existence of linear series on curves lying on an Enriques
surface and general in their complete linear system. Using a method that works
also below the Bogomolov-Reider range, we compute, in all cases, the gonality
of such curves. We also give a new result about the positive cone of line
bundles on an Enriques surface and we show how this relates to the gonality.


title:
IRCS/Subaru Observations of Water in the Inner Coma of Comet
  73P-B/Schwassmann-Wachmann 3: Spatially Resolved Rotational Temperatures and
  Ortho-Para Ratios

abstract:
  Comet 73P-B/Schwassmann-Wachmann 3 was observed with IRCS/Subaru at
geocentric distance of 0.074 AU on UT 10 May 2006. Multiple H2O emission lines
were detected in non-resonant fluorescence near 2.9 microns. No significant
variation in total H2O production rate was found during the (3 hour) duration
of our observations. H2O rotational temperatures and ortho-to-para abundance
ratios were measured for several positions in the coma. The temperatures
extracted from two different time intervals show very similar spatial
distributions. For both, the rotational temperature decreased from ~110 K to
~90 K as the projected distance from the nucleus increased from ~5 to ~30 km.
We see no evidence for OPR change in the coma. The H2O ortho-para ratio is
consistent with the statistical equilibrium value (3.0) for all spatially
resolved measurements. This implies a nuclear spin temperature higher than ~ 45
K.


title: The extreme, red afterglow of GRB 060923A: Distance or dust?

abstract:
  Gamma-ray bursts are powerful probes of the early universe, but locating and
identifying very distant GRBs remains challenging. We report here the discovery
of the K-band afterglow of Swift GRB 060923A, imaged within the first hour
post-burst, and the faintest so far found. It was not detected in any bluer
bands to deep limits, making it a candidate very high redshift burst (z>11).
However, our later-time optical imaging and spectroscopy reveal a faint galaxy
coincident with the GRB position which, if it is the host, implies a more
moderate redshift (most likely z<2.8) and therefore that dust is the likely
cause of the very red afterglow colour. This being the case, it is one of the
few instances so far found of a GRB afterglow with high dust extinction.


title: Measuring and testing dependence by correlation of distances

abstract:
  Distance correlation is a new measure of dependence between random vectors.
Distance covariance and distance correlation are analogous to product-moment
covariance and correlation, but unlike the classical definition of correlation,
distance correlation is zero only if the random vectors are independent. The
empirical distance dependence measures are based on certain Euclidean distances
between sample elements rather than sample moments, yet have a compact
representation analogous to the classical covariance and correlation.
Asymptotic properties and applications in testing independence are discussed.
Implementation of the test and Monte Carlo results are also presented.


title: Proposal for a loophole-free Bell test with electron spins of donors

abstract:
  So far, all experimental tests of Bell inequalities which must be satisfied
by all local realistic hidden-variable theories and are violated by quantum
mechanical predictions have left at least one loophole open. We propose a
feasible setup allowing for a loophole-free test of the Bell inequalities. Two
electron spin qubits of phosphorus donors in semiconductors in different
cavities 300 m apart are entangled through a bright coherent light and
postselections using homodyne measurements. The electron spins are then read
out randomly and independently by Alice and Bob, respectively, with unity
efficiency in less than 0.7$\mu$s by using optically induced spin to charge
transduction detected by radio-frequency single electron transistor. A
violation of Bell inequality larger than 37% and 18% is achievable provided
that the detection accuracy is 0.99 and 0.95, respectively.


title: Helical Symmetry in Linear Systems

abstract:
  We investigate properties of solutions of the scalar wave equation and
Maxwell's equations on Minkowski space with helical symmetry. Existence of
local and global solutions with this symmetry is demonstrated with and without
sources. The asymptotic properties of the solutions are analyzed. We show that
the Newman--Penrose retarded and advanced scalars exhibit specific symmetries
and generalized peeling properties.


title: Parity doubling from Weinberg sum rules

abstract:
  We investigate the relation among slopes and intercepts of Regge trajectories
for mesons of a given spin and different parities using large N_c arguments and
the matching to perturbative QCD in the deep-Minkowski region. For spin-1
mesons of opposite parities we prove that: a) for large and increasing N_c, the
scale \Lambda^{(V,A)} separating the resonance-dominated and the
perturbative-saturated region in the channels V,A grows as \sqrt{N_c}; b) to
satisfy the Weinberg sum rules the slopes of Regge trajectories for mesons of
opposite parities must coincide; c) their intercepts may differ and their
difference corresponds to the difference between \Lambda^V and \Lambda^A. Some
arguments indicate that this difference should tend to zero as N_c\to\infty.


title: Chiral Brownian rotor and heat pump

abstract:
  This paper provides some comprehensive calculations supporting the results in
Phys. Rev. Lett. 100, 130601 (2008) [arXiv:0711.1758].


title:
Cosmological perturbation theory, instantaneous gauges and local
  inertial frames

abstract:
  Linear perturbations of Friedmann-Robertson-Walker universes with any
curvature and cosmological constant are studied in a general gauge without
decomposition into harmonics. Desirable gauges are selected as those which
embody best Mach's principle: in these gauges local inertial frames can be
determined instantaneously via the perturbed Einstein field equations from the
distributions of energy and momentum in the universe. The inertial frames are
identified by their `accelerations and rotations' with respect to the
cosmological frames associated with the `Machian gauges'. In closed spherical
universes, integral gauge conditions are imposed to eliminate motions generated
by the conformal Killing vectors. The meaning of Traschen's integral constraint
vectors is thus elucidated. For all three types of FRW universes the Machian
gauges admit much less residual freedom than the synchronous or generalized
harmonic gauge. Mach's principle is best exhibited in the Machian gauges in
closed spherical universes. Independent of any Machian motivation the general
perturbation equations and discussion of gauges are useful for cosmological
perturbation theory.


title: Equivalence of Two Approaches for Quantum-Classical Hybrid Systems

abstract:
  We discuss two approaches that are used frequently to describe
quantum-classical hybrid system. One is the well-known mean-field theory and
the other adopts a set of hybrid brackets which is a mixture of quantum
commutators and classical Poisson brackets. We prove that these two approaches
are equivalent.


title:
Relativistic and Nonrelativistic Descriptions of Electron Energy Levels
  in a Static Magnetic Field

abstract:
  The physical consequences of the relativistic and nonrelativistic approaches
to describe the energy levels of electrons which propagate in a static
homogeneous magnetic field are considered. It is shown that for a given
strength of the magnetic field, the quantized energy levels of the electrons
calculated by nonrelativistic and relativistic equations differ substantially,
up to few orders of magnitude for a magnetic field of about 1 Tesla.
Experimental verification to resolve the discrepancy would be very welcome.


title:
Abrupt boundaries of intermediate phases and space filling in oxide
  glasses

abstract:
  Modulated DSC measurements on bulk (Na2O)x(GeO2)1-x glasses show a sharp
reversibility window in the 14% < x < 19% soda range, which correlates well
with a broad global minimum in molar volumes. Raman and IR reflectance TO and
LO mode frequencies exhibit anomalies between xc(1) = 14% (stress transition)
and xc(2) = 19% (rigidity transition), with optical elasticity power-laws
confirming the nature of the transitions . Birefringence measurements dramatize
the macroscopically stress-free nature of the Intermediate Phase in the
reversibility window.


title: Fermionic un-particles, gauge interactions and the $\beta$ function

abstract:
  The dynamics of fermionic unparticles is developed from first principles. It
is shown that any unparticle, whether fermionic or bosonic, can be recast in
terms of a canonically quantized field, but with non-local interaction terms.
We further develop a possible gauge theory for fermionic unparticles. Computing
the consequent contribution of un-fermions to the $\beta$ function of the
theory, it is shown that this can be viewed as the sum of two contributions,
one fermion-like and the other scalar-like. However, if full conformal
invariance is imposed, the latter vanishes identically. We discuss the
consequences thereof as well as some general phenomenological issues.


title:
Family of non-equilibrium statistical operators and influence of the
  past on the present

abstract:
  A family of non-equilibrium statistical operators (NSO) is introduced which
differ by the system lifetime distribution over which the quasi-equilibrium
(relevant) distribution is averaged. This changes the form of the source in the
Liouville equation, as well as the expressions for the kinetic coefficients,
average fluxes, and kinetic equations obtained with use of NSO. It is possible
to choose a class of lifetime distributions for which thermodynamic limiting
transition and to tend to infinity of average lifetime of system is reduced to
the result received at exponential distribution for lifetime, used by Zubarev.
However there is also other extensive class of realistic distributions of
lifetime of system for which and after to approach to infinity of average
lifetime of system non-equilibrium properties essentially change. For some
distributions the effect of "finite memory" when only the limited interval of
the past influence on behaviour of system is observed. It is shown, how it is
possible to spend specification the description of effects of memory within the
limits of NSO method, more detailed account of influence on evolution of system
of quickly varying variables through the specified and expanded form of density
of function of distribution of lifetime. The account of character of history of
the system, features of its conduct in the past, can have substantial influence
on non-equilibrium conduct of the system in a present moment time.


title:
Estimation of the covariance matrix of random effects in longitudinal
  studies

abstract:
  Longitudinal studies are often conducted to explore the cohort and age
effects in many scientific areas. The within cluster correlation structure
plays a very important role in longitudinal data analysis. This is because not
only can an estimator be improved by incorporating the within cluster
correlation structure into the estimation procedure, but also the within
cluster correlation structure can sometimes provide valuable insights in
practical problems. For example, it can reveal the correlation strengths among
the impacts of various factors. Motivated by data typified by a set from
Bangladesh pertinent to the use of contraceptives, we propose a random effect
varying-coefficient model, and an estimation procedure for the within cluster
correlation structure of the proposed model. The estimation procedure is
optimization-free and the proposed estimators enjoy asymptotic normality under
mild conditions. Simulations suggest that the proposed estimation is
practicable for finite samples and resistent against mild forms of model
misspecification. Finally, we analyze the data mentioned above with the new
random effect varying-coefficient model together with the proposed estimation
procedure, which reveals some interesting sociological dynamics.


title: Classifying Hilbert functions of fat point subschemes in $\mathbb P^2$

abstract:
  A recent paper by the first and third authors together with Sabourin raised
the question of what the possible Hilbert functions are for fat point
subschemes of the form $2p_1+...+2p_r$, for all possible choices of $r$
distinct points in the projective plane. We study this problem for $r$ points
in the plane over an algebraically closed field $k$ of arbitrary characteristic
in case either $r \le 8$ or the points lie on a (possibly reducible) conic. In
either case, it follows from work of the second author that there are only
finitely many configuration types of points, where our notion of configuration
type is a generalization of the notion of a representable combinatorial
geometry, also known as a representable simple matroid. (We say $p_1,...,p_r$
and $p'_1,...,p'_r$ have the same {\it configuration type} if for all choices
of nonnegative integers $m_i$, $Z=m_1p_1+...+m_rp_r$ and
$Z'=m_1p'_1+...+m_rp'_r$ have the same Hilbert function.) Assuming either that
$7 \le r\le 8$ (see recent work of Guardo and the second author for the cases
$r\le 6$) or that the points $p_i$ lie on a conic, we explicitly determine all
the configuration types, and show how the configuration type and the
coefficients $m_i$ determine (in an explicitly computable way) the Hilbert
function (and sometimes the graded Betti numbers) of $Z=m_1p_1+...+m_rp_r$. We
demonstrate our results by explicitly listing all Hilbert functions for schemes
of $r\le 8$ double points, and for each Hilbert function we state precisely how
the points must be arranged (in terms of the configuration type) to obtain that
Hilbert function.


title:
Examples of cohomology manifolds which are not homologically locally
  connected

abstract:
  Bredon has constructed a 2-dimensional compact cohomology manifold which is
not homologically locally connected, with respect to the singular homology. In
the present paper we construct infinitely many such examples (which are in
addition metrizable spaces) in all remaining dimensions $n \ge 3$.


title: Manifestly-covariant chiral PT calculation of nucleon Compton scattering

abstract:
  We compute the Compton scattering off the nucleons in the framework of
manifestly covariant baryon chiral perturbation theory (B$\chi$PT). The results
for observables differ substantially from the corresponding calculations in
heavy-baryon chiral perturbation theory (HB$\chi$PT), most appreciably in the
forward kinematics. We verify that the covariant $p^3$ result fulfills the
forward-Compton-scattering sum rules. We also explore the effect of the
$\Delta$(1232) resonance at order $p^4/\varDelta$, with $\varDelta\approx 300$
MeV, the resonance excitation energy. We find that the substantial effect of
the $\Delta$-excitation on the nucleon polarizabilities can naturally be
accommodated in the manifestly covariant calculation.


title:
Dipole Oscillations of a Bose-Einstein Condensate in Presence of Defects
  and Disorder

abstract:
  We consider dipole oscillations of a trapped dilute Bose-Einstein condensate
in the presence of a scattering potential consisting either in a localized
defect or in an extended disordered potential. In both cases the breaking of
superfluidity and the damping of the oscillations are shown to be related to
the appearance of a nonlinear dissipative flow. At supersonic velocities the
flow becomes asymptotically dissipationless.


title: Fr\'{e}chet-Urysohn fans in free topological groups

abstract:
  In this paper we answer the question of T. Banakh and M. Zarichnyi
constructing a copy of the Fr\'echet-Urysohn fan $S_\w$ in a topological group
$G$ admitting a functorial embedding $[0,1]\subset G$. The latter means that
each autohomeomorphism of $[0,1]$ extends to a continuous homomorphism of $G$.
This implies that many natural free topological group constructions (e.g. the
constructions of the Markov free topological group, free abelian topological
group, free totally bounded group, free compact group) applied to a Tychonov
space $X$ containing a topological copy of the space $\IQ$ of rationals give
topological groups containing $S_\w$.


title:
Correction. Strong invariance principles for sequential Bahadur--Kiefer
  and Vervaat error processes of long-range dependent sequences

abstract:
  Correction to The Annals of Statistics (2006) 34, 1013--1044 [URL:
http://projecteuclid.org/euclid.aos/1151418250]


title:
Determination of the effective strong coupling constant
  alpha_{s,g_1}(Q^2) from CLAS spin structure function data

abstract:
  We present a new extraction of the effective strong coupling constant
\alpha_{s,g_1}(Q^2). The result agrees with a previous determination and
extends the measurement of the low and high Q^2 behavior of \alpha_{s,g_1}(Q^2)
that was previously deduced from sum rules. In particular, it experimentally
verifies the lack of Q^2-dependence of \alpha_{s,g_1}(Q^2) in the low Q^2
limit. This fact is necessary for application of the AdS/CFT correspondence to
QCD calculations. We provide a parameterization of \alpha_{s,g_1}(Q^2) thatcan
equivalently be used to parameterize the Q^2-dependence of the generalized
Gerasimov-Drell-Hearn and Bjorken sums.


title:
The Interplay Between the "Low" and "High" Energy CP-Violation in
  Leptogenesis

abstract:
  We analyse within the "flavoured" leptogenesis scenario of baryon asymmetry
generation, the interplay of the "low energy" CP-violation, originating from
the PMNS neutrino mixing matrix $U$, and the "high energy" CP-violation which
can be present in the matrix of neutrino Yukawa couplings, $\lambda$, and can
manifest itself only in "high" energy scale processes. The type I see-saw model
with three heavy right-handed Majorana neutrinos having hierarchical spectrum
is considered. The "orthogonal" parametrisation of the matrix of neutrino
Yukawa couplings, which involves a complex orthogonal matrix $R$, is employed.
In this approach the matrix $R$ is the source of "high energy" CP-violation.
Results for normal hierarchical (NH) and inverted hierarchical (IH) light
neutrino mass spectrum are derived in the case of decoupling of the heaviest RH
Majorana neutrino. It is shown that taking into account the contribution to
$Y_B$ due to the CP-violating phases in the neutrino mixing matrix $U$ can
change drastically the predictions for $Y_B$, obtained assuming only "high
energy" CP-violation from the $R$-matrix is operative in leptogenesis. In the
case of IH spectrum, in particular, there exist significant regions in the
corresponding parameter space where the purely "high energy" contribution in
$Y_B$ plays a subdominant role in the production of baryon asymmetry compatible
with the observations.


title: A diagrammatic approach to categorification of quantum groups I

abstract:
  To each graph without loops and multiple edges we assign a family of rings.
Categories of projective modules over these rings categorify
$U^-_q(\mathfrak{g})$, where $\mathfrak{g}$ is the Kac-Moody Lie algebra
associated with the graph.


title: Multiple timescales in a model for DNA denaturation dynamics

abstract:
  The denaturation dynamics of a long double-stranded DNA is studied by means
of a model of the Poland-Scheraga type. We note that the linking of the two
strands is a locally conserved quantity, hence we introduce local updates that
respect this symmetry. Linking dissipation via untwist is allowed only at the
two ends of the double strand. The result is a slow denaturation characterized
by two time scales that depend on the chain length $L$. In a regime up to a
first characteristic time $\tau_1\sim L^{2.15}$ the chain embodies an
increasing number of small bubbles. Then, in a second regime, bubbles coalesce
and form entropic barriers that effectively trap residual double-stranded
segments within the chain, slowing down the relaxation to fully molten
configurations, which takes place at $\tau_2\sim L^3$. This scenario is
different from the picture in which the helical constraints are neglected.


title: Dense planetary rings and the viscous overstability

abstract:
  This paper examines the onset of the viscous overstability in dense
particulate rings. First, we formulate a dense gas kinetic theory that is
applicable to the Saturnian system. Our model is essentially that of Araki and
Tremaine (1986), which we show can be both simplified and generalised. Second,
we put this model to work computing the equilibrium properties of dense
planetary rings, which we subsequently compare with the results of N-body
simulations, namely those of Salo (1991). Finally, we present the linear
stability analyses of these equilibrium states, and derive criteria for the
onset of viscous overstability in the self-gravitating and non-self-gravitating
cases. These are framed in terms of particle size, orbital frequency, optical
depth, and the parameters of the collision law. Our results compare favourably
with the simulations of Salo et al. (2001). The accuracy and practicality of
the continuum model we develop encourages its general use in future
investigations of nonlinear phenomena.


title: Generalization of Friedberg-Lee Symmetry

abstract:
  We study the possible origin of Friedberg-Lee symmetry. First, we propose the
generalized Friedberg-Lee symmetry in the potential by including the scalar
fields in the field transformations, which can be broken down to the FL
symmetry spontaneously. We show that the generalized Friedberg-Lee symmetry
allows a typical form of Yukawa couplings, and the realistic neutrino masses
and mixings can be generated via see-saw mechanism. If the right-handed
neutrinos transform non-trivially under the generalized Friedberg-Lee symmetry,
we can have the testable TeV scale see-saw mechanism. Second, we present two
models with the $SO(3)\times U(1)$ global flavour symmetry in the lepton
sector. After the flavour symmetry breaking, we can obtain the charged lepton
masses, and explain the neutrino masses and mixings via see-saw mechanism.
Interestingly, the complete neutrino mass matrices are similar to those of the
above models with generalized Friedberg-Lee symmetry. So the Friedberg-Lee
symmetry is the residual symmetry in the neutrino mass matrix after the
$SO(3)\times U(1)$ flavour symmetry breaking.


title:
Driven interfaces in random media at finite temperature : is there an
  anomalous zero-velocity phase at small external force ?

abstract:
  The motion of driven interfaces in random media at finite temperature $T$ and
small external force $F$ is usually described by a linear displacement $h_G(t)
\sim V(F,T) t$ at large times, where the velocity vanishes according to the
creep formula as $V(F,T) \sim e^{-K(T)/F^{\mu}}$ for $F \to 0$. In this paper,
we question this picture on the specific example of the directed polymer in a
two dimensional random medium. We have recently shown (C. Monthus and T. Garel,
arxiv:0802.2502) that its dynamics for F=0 can be analyzed in terms of a strong
disorder renormalization procedure, where the distribution of renormalized
barriers flows towards some "infinite disorder fixed point". In the present
paper, we obtain that for small $F$, this "infinite disorder fixed point"
becomes a "strong disorder fixed point" with an exponential distribution of
renormalized barriers. The corresponding distribution of trapping times then
only decays as a power-law $P(\tau) \sim 1/\tau^{1+\alpha}$, where the exponent
$\alpha(F,T)$ vanishes as $\alpha(F,T) \propto F^{\mu}$ as $F \to 0$. Our
conclusion is that in the small force region $\alpha(F,T)<1$, the divergence of
the averaged trapping time $\bar{\tau}=+\infty$ induces strong
non-self-averaging effects that invalidate the usual creep formula obtained by
replacing all trapping times by the typical value. We find instead that the
motion is only sub-linearly in time $h_G(t) \sim t^{\alpha(F,T)}$, i.e. the
asymptotic velocity vanishes V=0. This analysis is confirmed by numerical
simulations of a directed polymer with a metric constraint driven in a traps
landscape. We moreover obtain that the roughness exponent, which is governed by
the equilibrium value $\zeta_{eq}=2/3$ up to some large scale, becomes equal to
$\zeta=1$ at the largest scales.


title: Preserving $Z$-sets by Dranishnikov's resolution

abstract:
  We prove that Dranishnikov's $k$-dimensional resolution $d_k\colon \mu^k\to
Q$ is a UV$^{n-1}$-divider of Chigogidze's $k$-dimensional resolution $c_k$.
This fact implies that $d_k^{-1}$ preserves $Z$-sets. A further development of
the concept of UV$^{n-1}$-dividers permits us to find sufficient conditions for
$d_k^{-1}(A)$ to be homeomorphic to the N\"{o}beling space $\nu^k$ or the
universal pseudoboundary $\sigma^k$. We also obtain some other applications.


title: Shock acceleration as origin of the radio relic in A521?

abstract:
  We present new high sensitivity observations of the radio relic in A521
carried out with the Giant Metrewave Radio Telescope at 327 MHz and with the
Very Large Array at 4.9 and 8.5 GHz. We imaged the relic at these frequencies
and carried out a detailed spectral analysis, based on the integrated radio
spectrum between 235 MHz and 4.9 GHz, and on the spectral index image in the
frequency range 327-610 MHz. To this aim we used the new GMRT observations and
other proprietary as well as archival data. We also searched for a possible
shock front co-located with the relic on a short archival Chandra X-ray
observation of the cluster. The integrated spectrum of the relic is consistent
with a single power law; the spectral index image shows a clear trend of
steepening going from the outer portion of the relic toward the cluster centre.
We discuss the origin of the source in the light of the theoretical models for
the formation of cluster radio relics. Our results on the spectral properties
of the relic are consistent with acceleration of relativistic electrons by a
shock in the intracluster medium. This scenario is further supported by our
finding of an X-ray surface brightness edge coincident with the outer border of
the radio relic. This edge is likely a shock front.


title: Gravitation Is Torsion

abstract:
  The mantra about gravitation as curvature is a misnomer. The curvature tensor
for a standard of rest does not describe acceleration in a gravitational field
but the \underline{gradient} of the acceleration (e.g. geodesic deviation). The
gravitational field itself (Einstein 1907) is essentially an accelerated
reference system. It is characterized by a field of orthonormal four-legs in a
Riemann space with Lorentz metric. By viewing vectors at different events
having identical leg-components as parallel (teleparallelism) the geometry in a
gravitational field defines torsion. This formulation of Einstein's 1907
principle of equivalence uses the same Riemannian metric and the same 1916
field equations for his theory of gravitation and fulfills his vision of
General Relativity.


title: Regularity of conjugacies of algebraic actions of Zariski dense groups

abstract:
  Let \alpha_0 be an affine action of a discrete group \Gamma on a compact
homogeneous space X and \alpha_1 a smooth action of \Gamma on X which is
C^1-close to \alpha_0. We show that under some conditions, every topological
conjugacy between \alpha_0 and \alpha_1 is smooth. In particular, our results
apply to Zariski dense subgroups of SL_d(Z) acting on the torus T^d and Zariski
dense subgroups of a simple noncompact Lie group G acting on a compact
homogeneous space X of G with an invariant measure.


title: On extending actions of groups

abstract:
  Problems of dense and closed extension of actions of compact transformation
groups are solved. The method developed in the paper is applied to problems of
extension of equivariant maps and of construction of equivariant
compactifications.


title:
The Search for Stellar Companions to Exoplanet Host Stars Using the
  CHARA Array

abstract:
  Most exoplanets have been discovered via radial velocity studies, which are
inherently insensitive to orbital inclination. Interferometric observations
will show evidence of a stellar companion if it sufficiently bright, regardless
of the inclination. Using the CHARA Array, we observed 22 exoplanet host stars
to search for stellar companions in low-inclination orbits that may be
masquerading as planetary systems. While no definitive stellar companions were
discovered, it was possible to rule out certain secondary spectral types for
each exoplanet system observed by studying the errors in the diameter fit to
calibrated visibilities and by searching for separated fringe packets.


title:
A Consistent Prescription for Combining Perturbative Calculations and
  Parton Showers in Case of Associated Z b anti-b Hadroproduction

abstract:
  This paper presents the method of combining parton shower formalism with
perturbative calculations (matrix elements) in form of a Monte-Carlo algorithm
for the process g g -> Z b anti-b,consistenlty including the heavy quark masses
and overlap removal.


title: Multipolar corrections for Lense-Thirring precession

abstract:
  For stationary axially symmetric spacetimes we find a simple expression for
the Lense-Thirring precession in terms of the Ernst potential. This expression
is used to compute, in the weak field approximation, the major non-spherical
contributions to the precession of a gyroscope orbiting the Earth. We reproduce
previously known results and give a new estimation for non-spherical
contributions.


title: Neutralino decay of MSSM neutral Higgs bosons

abstract:
  We compute the one loop corrected effective Lagrangian for the
neutralino-neutralino-neutral Higgs interactions $\chi^{0}_{\ell}
\chi^{0}_kH^{0}_m$. The analysis completes the previous analyses where similar
corrections were computed for the $\bar{f} f H^{0}_m$ couplings, where $f$
stands for Standard Model quarks and leptons and for the
chargino-chargino-neutral Higgs couplings $\chi^{+}_l \chi^{-}_kH^{0}_m$ within
the minimal supersymmetric standard model MSSM. The effective one loop
Lagrangian is then applied to the computation of the neutral Higgs decays. The
sizes of the supersymmetric loop corrections of the neutral Higgs decay widths
into $\chi^{0}_{\ell} \chi^{0}_k$ (${\ell}=1,2,3,4$; $k=1,2,3,4$) are
investigated and the supersymmetric loop correction is found to be in the range
of $\sim 10%$ in significant regions of the parameter space. By including the
loop corrections of the other decay channels $\bar{b} b$, $\bar{t} t$,
$\bar{\tau} \tau$, $\bar{c} c$, and $\chi^{-}_i \chi^{+}_j$ ($i=1,2$; $j=1,2$),
the corrections to branching ratios for $H^{0}_m\to \chi^{0}_{\ell} \chi^{0}_k$
can reach as high as 50%. The effects of CP phases on the branching ratio are
also investigated. A discussion of the implications of the analysis for
colliders is given.


title: First-principles study of improper ferroelectricity in TbMnO3

abstract:
  We have carried out a first-principles theoretical study of the magnetically
induced polarization in orthorhombic TbMnO3, a prototypical material in which a
cycloidal spin structure generates an electric polarization via the spin-orbit
interaction. We compute both the electronic and the lattice-mediated
contributions to the polarization and find that the latter is strongly
dominant. We analyze the spin-orbit induced forces and lattice displacements
from both atomic and mode-decomposition viewpoints, and show that a simple
model based on nearest Mn--Mn neighbor Dzyaloshinskii-Moriya interactions is
not able to account fully for the results. The direction and magnitude of our
computed polarization are in good agreement with experiment.


title: Homological stability for certain classical groups

abstract:
  We prove homological stability for standard unitary groups over R, C and H
and for general linear groups over skew-fields with infinite centre. We focus
on the similarities and differences of these proofs. Both proofs are due to
Chih-Han Sah (Homology of classical Lie groups made discrete I: Stability
theorems and Schur multipliers. Comment. Math. Helv. 61(2), 1986).


title: Surface subgroups from homology

abstract:
  Let G be a word-hyperbolic group, obtained as a graph of free groups
amalgamated along cyclic subgroups. If H_2(G;Q) is nonzero, then G contains a
closed hyperbolic surface subgroup. Moreover, the unit ball of the
Gromov-Thurston norm on H_2(G;R) is a finite-sided rational polyhedron.


title:
The contribution of the Unresolved Extragalactic Radio Sources to the
  Brightness Temperature of the sky

abstract:
  The contribution of the Unresolved Extragalactic Radio Sources to the diffuse
brightness of the sky was evaluated using the source number - flux measurements
available in literature. We first optimized the fitting function of the data
based on number counts distribution. We then computed the brightness
temperature at various frequencies from 151 MHz to 8440 MHz and derived its
spectral dependence. As expected the frequency dependence can be described by a
power law with a spectral index $\gamma \simeq -2.7$, in agreement with the
flux emitted by the {\it steep spectrum} sources. The contribution of {\it flat
spectrum} sources becomes relevant at frequencies above several GHz. Using the
data available in literature we improved our knowledge of the brightness of the
unresolved extragalactic radio sources. The results obtained have general
validity and they can be used to disentangle the various contributions of the
sky brightness and to evaluate the CMB temperature.


title:
Baryon enhancement in high-density QCD and relativistic heavy ion
  collisions

abstract:
  We argue that the collinear factorization of the fragmentation functions in
high energy nuclear collisions breaks down at transverse momenta $p_T \lesssim
Q_s/g$ due to high parton densities in the colliding hadrons and/or nuclei. We
find that gluon recombination dominates in that $p_T$ region. We calculate the
inclusive cross-section for $\pi$ meson and nucleon production using the low
energy theorems for the scale anomaly in QCD, and compare our quantitative
baryon-to-meson ratio to the RHIC data.


title: Stretching helical nano-springs at finite temperature

abstract:
  Using dynamic simulations and analytic methods, we study the elastic response
of a helical filament subject to uniaxial tension over a wide range of bend and
twist persistence length. A low-pitch helix at low temperatures exhibits a
stretching instability and the force-extension curve consists of a sequence of
spikes. At elevated temperature (i.e. small persistence lengths) the helix
melts and a pronounced force plateau is obtained in the fixed-extension
ensemble. The torque boundary condition significantly affects the resulting
elastic properties.


title: Exploring the meson spectrum with twisted mass lattice QCD

abstract:
  Numerical simulations with access to all possible meson quantum numbers,
J^{PC}, are presented using two-flavor (up and down) quenched twisted mass
lattice QCD with three different lattice spacings and four different quark
masses. The connection between the quantum numbers (P and C) and the symmetries
of the twisted mass action are discussed, as is the connection between J and
the lattice rotation group, for the 400 operators used in this study. Curve
fitting of this large data set is accomplished by using an evolutionary fitting
algorithm. Results are reported for conventional and exotic quantum numbers.


title: Measuring the 2D Vector Aspect of Momentum Using Only One Dimension

abstract:
  Without the use of cameras to record 2D motion and an appropriate analysis
tool, creating a laboratory activity for students to experience the vector
nature of momentum can be challenging. Even with appropriate measurement tools,
it is difficult to predict the final velocities of the objects in the system
unless you know the impact parameter. For accurately predicting the final
velocities, the typical momentum experiment involves colliding gliders on an
air track or colliding low-friction carts on a track. These one-dimensional
experiments require the vector nature of momentum for correct analysis but do
not require breaking the momentum vector into components.
  In this work we present another experiment, using this aforementioned
equipment, which only requires a stopwatch, ruler, and mass balance yet
requires the two-dimensional analysis of the momentum vector.


title: AsteroFLAG: first results from hare-and-hounds Exercise 1

abstract:
  We report on initial results from the first phase of Exercise 1 of the
asteroFLAG hare and hounds. The asteroFLAG group is helping to prepare for the
asteroseismology component of NASA's Kepler mission, and the first phase of
Exercise 1 is concerned with testing extraction of estimates of the large and
small frequency spacings of the low-degree p modes from Kepler-like artificial
data. These seismic frequency spacings will provide key input for complementing
the exoplanet search data.


title: Angular Momentum of a Brane-world Model

abstract:
  In this paper we discuss the properties of the general covariant angular
momentum of a five-dimensional brane-world model. Through calculating the total
angular momentum of this model, we are able to analyze the properties of the
total angular momentum in the inflationary RS model. We show that the
space-like components of the total angular momentum of are all zero while the
others are non-zero, which agrees with the results from ordinary RS model.


title:
Diffusion and desorption of SiH3 on hydrogenated H:Si(100)-(2x1) from
  first principles

abstract:
  We have studied diffusion pathways of a silyl radical adsorbed on the
hydrogenated Si (100)-(2x1) surface by density-functional theory. The process
is of interest for the growth of crystalline silicon by plasma-enhanced
chemical vapor deposition. Preliminary searches for migration mechanisms have
been performed using metadynamics simulations. Local minima and transition
states have been further refined by using the nudged-elastic-band method.
Barriers for diffusion from plausible adsorption sites as low as 0.2 eV have
been found, but trap states have also been spotted, leading to a more stable
configuration, with escape barriers of 0.7 eV. Diffusion among weakly bound
physisorbed states is also possible with very low activation barriers (<50
meV). However, desorption mechanisms (either as SiH3 or as SiH4) from
physisorbed or more strongly bound adsorption configurations turn out to have
activation energies similar to diffusion barriers. Kinetic Monte Carlo
simulations based on ab initio activation energies show that the silyl radical
diffuses at most by a few lattice spacing before desorbing at temperatures in
the range 300-1000 K.


title:
Contact mechanics: contact area and interfacial separation from small
  contact to full contact

abstract:
  We present a molecular dynamics study of the contact between a rigid solid
with a randomly rough surface and an elastic block with a flat surface. The
numerical calculations mainly focus on the contact area and the interfacial
separation from small contact (low load) to full contact (high load). For small
load the contact area varies linearly with the load and the interfacial
separation depends logarithmically on the load. For high load the contact area
approaches the nominal contact area (i.e., complete contact), and the
interfacial separation approaches zero. The numerical results have been
compared with analytical theory and experimental results. They are in good
agreement with each other. The present findings may be very important for soft
solids, e.g., rubber, or for very smooth surfaces, where complete contact can
be reached at moderate high loads without plastic deformation of the solids.


title: Principalization of ideals in abelian extensions of number fields

abstract:
  We give the complete proof of a conjecture of Georges Gras which claims that,
for any extension $K/k$ of number fields in which at least one infinite place
is totally split, every ideal $I$ of $K$ principalizes in the compositum
$Kk^{ab}$ of $K$ with the maximal abelian extension $k^{ab}$ of $k$


title: Is turbulent mixing a self convolution process ?

abstract:
  Experimental results for the evolution of the probability distribution
function (PDF) of a scalar mixed by a turbulence flow in a channel are
presented. The sequence of PDF from an initial skewed distribution to a sharp
Gaussian is found to be non universal. The route toward homogeneization depends
on the ratio between the cross sections of the dye injector and the channel. In
link with this observation, advantages, shortcomings and applicability of
models for the PDF evolution based on a self-convolution mechanisms are
discussed.


title:
Extreme statistics and volume fluctuations in a confined one-dimensional
  gas

abstract:
  We consider the statistics of volume fluctuations in a one-dimensional
classical gas of non-interacting particles confined by a piston, and subjected
to an arbitrary external potential. We show that despite the absence of
interactions between particles, volume fluctuations of the gas are
non-Gaussian, and are described by generalized extreme value distributions. The
continuous shape parameter of these distributions is related to the ratio
between the force acting on the piston, and the force acting on the particles.
Gaussian fluctuations are recovered in the strong compression limit, when the
effect of the external potential becomes negligible. Consequences for the
thermodynamics are also discussed.


title: Density-Functional Theory of Graphene Sheets

abstract:
  We outline a Kohn-Sham-Dirac density-functional-theory (DFT) scheme for
graphene sheets that treats slowly-varying inhomogeneous external potentials
and electron-electron interactions on an equal footing. The theory is able to
account for the the unusual property that the exchange-correlation contribution
to chemical potential increases with carrier density in graphene. Consequences
of this property, and advantages and disadvantages of using the DFT approach to
describe it, are discussed. The approach is illustrated by solving the
Kohn-Sham-Dirac equations self-consistently for a model random potential
describing charged point-like impurities located close to the graphene plane.
The influence of electron-electron interactions on these non-linear screening
calculations is discussed at length, in the light of recent experiments
reporting evidence for the presence of electron-hole puddles in nearly-neutral
graphene sheets.


title: Superheavy Elements in the Magic Islands

abstract:
  Recent microscopic calculation based on the density functional theory
predicts long-lived superheavy elements in a variety of shapes, including
spherical, axial and triaxial configurations. Only when N=184 is approached one
expects superheavy nuclei that are spherical in their ground states. Magic
islands of extra-stability have been predicted to be around Z=114, 124 or, 126
with N=184, and Z=120, with N=172. However, the question of whether the
fission-survived superheavy nuclei with high Z and N would live long enough for
detection or, undergo alpha-decay in a very short time remains open. In this
talk I shall present results of our calculations of alpha-decay half lives of
heavy and superheavy nuclei. Calculations, carried out in a WKB framework using
density-dependent M3Y interaction, have been found to reproduce the
experimental data quite well. Fission survived Sg nuclei with Z=106, N=162 is
predicted to have the highest alpha-decay half life (~3.2 hrs) in the
Z=106-108, N=160-164 region called, small island/peninsula. Neutron-rich (N
>170) superheavy nuclei with Z >118 are found to have half-lives of the order
of microseconds or, less.


title:
Triggered massive-star formation on the borders of Galactic HII regions.
  IV- Star formation at the periphery of Sh2-212

abstract:
  Aims: We wish to establish whether sequential star formation is taking place
at the periphery of the Galactic HII region Sh2-212.
  Methods: We present CO millimetre observations of this region obtained at the
IRAM 30-m telescope to investigate the distribution of associated molecular
material. We also use deep JHK observations obtained at the CFHT to study the
stellar content of the region, and radio observations obtained at the VLA to
look for the presence of an ultra-compact (UC) HII region and for maser
emission.
  Results: In the optical, Sh2-212 is spherically symmetric around its central
exciting cluster. This HII region is located along a molecular filament. A
thin, well-defined half ring of molecular material surrounds the brightest part
of the HII region at the rear and is fragmented. The most massive fragment
(~200 solar masses) contains a massive young stellar object displaying a
near-IR excess; its spectral energy distribution indicates a high-mass
(~14solar masses), high-temperature (~30000K), and high-luminosity (~17000
solar luminosities) source. This object ionizes a UC HII region.
  Conclusions: Sh2-212 is a good example of massive-star formation triggered
via the collect and collapse process. The massive YSO observed at its periphery
is a good candidate for a massive star formed in isolation.


title:
Demonstration of perfect coherence preservation for matter-waves
  perturbed by a delta-kicked rotor

abstract:
  We demonstrate perfect coherence preservation in an atom interferometer
perturbed by kicks from off-resonant standing wave pulses. Under most
conditions, the decoherence induced by the pulses reduces the signal; however,
the coherence is perfectly preserved when the kicking period is equal to the
rational fraction of the inverse atomic recoil frequency, independent of the
number or the randomness of the strength of the applied kicks. The width
narrowing of coherence revival as a function of increasing kick number and
strength provides a new accurate measurement of the recoil frequency.


title:
Kondo-Dicke resonances in electronic transport through triple quantum
  dots

abstract:
  Electronic transport through a triple quantum dot system, with only a single
dot coupled directly to external leads, is considered theoretically. The model
includes Coulomb correlations in the central dot, while such correlations in
the two side-coupled dots are omitted. The infinite-U mean-field slave-boson
approach is used to obtain basic transport characteristics in the Kondo regime.
When tuning position of the side-coupled dots' levels, transition from
subradiant to superradiant like mode (and vice versa) has been found in the
spectral function, in analogy to the Dicke effect in atomic physics. Bias
dependence of the differential conductance and zero frequency shot noise is
also analysed.


title:
The Tracy--Widom limit for the largest eigenvalues of singular complex
  Wishart matrices

abstract:
  This paper extends the work of El Karoui [Ann. Probab. 35 (2007) 663--714]
which finds the Tracy--Widom limit for the largest eigenvalue of a nonsingular
$p$-dimensional complex Wishart matrix $W_{\mathbb{C}}(\Omega_p,n)$ to the case
of several of the largest eigenvalues of the possibly singular $(n<p)$ matrix
$W_{\mathbb{C}}(\Omega_p,n).$ As a byproduct, we extend all results of Baik,
Ben Arous and Peche [Ann. Probab. 33 (2005) 1643--1697] to the singular Wishart
matrix case. We apply our findings to obtain a 95% confidence set for the
number of common risk factors in excess stock returns.


title:
Proton Stability, Dark Matter and Light Color Octet Scalars in Adjoint
  SU(5) Unification

abstract:
  The unification of gauge interactions in the context of Adjoint SU(5) and its
phenomenological consequences are investigated. We show the allowed mass
spectrum of the theory which is compatible with proton decay, and discuss the
possibility to have a cold dark matter candidate. Due to the upper bounds on
the proton decay partial lifetimes, tau (p --> K^+ nubar) < 9.3 10^{36} years
and tau(p --> pi^+ nubar) < 3.0 10^{35} years, the theory could be tested at
future proton decay experiments. The theory predicts also light scalar color
octets which could be produced at the Large Hadron Collider.


title:
On the electronic structure of the charge-ordered phase in epitaxial and
  polycrystalline La1-xCaxMnO3 (x = 0.55, 0.67) perovskite manganites

abstract:
  In this work the charge transport properties of charge ordered (CO)
La1-xCaxMnO3 (LCMO) (x= 0.55, 0.67) epitaxial thin films and polycrystals are
discussed following the recent controversy of localised electron states vs.
weakly or de- localised charge density wave (CDW) states in CO manganites. The
transport properties were investigated by current vs. voltage, direct current
resistivity vs. temperature, local activation energy vs. temperature,
magnetoresistance and admittance spectroscopy measurements, which all indicated
a localised electronic structure in the single CO phase. Delocalised charge
anomalies observed previously may be restricted to phase separated materials.


title: Symplectic tomography of ultracold gases in tight-waveguides

abstract:
  The phase space is the natural ground to smoothly extrapolate between local
and non-local correlation functions. With this objective, we introduce the
symplectic tomography of many-body quantum gases in tight-waveguides, and
concentrate on the reduced single-particle symplectic tomogram (RSPST) whose
marginals are the density profile and momentum distribution. We present an
operational approach to measure the RSPST from the time evolution of the
density profile after shutting off the interactions in a variety of relevant
situations: free expansion, fall under gravity, and oscillations in a harmonic
trap. From the RSPST, the one-body density matrix of the trapped state can be
reconstructed.


title: Search for extrasolar planets with high-precision relative astrometry

abstract:
  We present our search program for substellar companions using high-precision
relative astronomy. Due to its orbital motion around the star, an unseen
substellar companion would produce a periodic "wobble" of the host star, which
is the astrometric signal of the unseen companion. By measuring the separation
between the components of stellar double and triple systems, we want to measure
this astrometric signal of a possible unseen companion indirectly as a relative
and periodic change of these separations. Using a new observation mode (the
"cube-mode") where the frames were directly saved in cubes with nearly no loss
of time during the readout, an adaptive optics system to correct for
atmospheric noise and an infrared narrow band filter in the near infrared to
suppress differential chromatic refraction (DCR) effects we achive for our
first target (the double star HD 19994) a relative precision for the separation
measurements of about 100...150 micro-arsecond per epoch. To reach a precision
in the micro-arcsec-regime, we use a statistical approach. We take several
thousand frames per target and epoche and after a verification of a Gaussian
distribution the measurement precision can be calculated as the standard
deviation of our measurements divided by the square root of the number of
Gaussian distributed measurements. Our first observed target is the stellar
binary HD 19994 A & B, where the A component has a known radial velocity planet
candidate.


title: The Calderon Projection: New Definition and Applications

abstract:
  We consider an arbitrary linear elliptic first--order differential operator A
with smooth coefficients acting between sections of complex vector bundles E,F
over a compact smooth manifold M with smooth boundary N. We describe the
analytic and topological properties of A in a collar neighborhood U of N and
analyze various ways of writing A|U in product form. We discuss the sectorial
projections of the corresponding tangential operator, construct various
invertible doubles of A by suitable local boundary conditions, obtain Poisson
type operators with different mapping properties, and provide a canonical
construction of the Calderon projection. We apply our construction to
generalize the Cobordism Theorem and to determine sufficient conditions for
continuous variation of the Calderon projection and of well--posed selfadjoint
Fredholm extensions under continuous variation of the data.


title: (N)LO Simulation of Chargino Production and Decay

abstract:
  We consider NLO chargino production and decays at the ILC. For this, we
present an NLO extension of the Monte Carlo Event Generator Whizard including
the NLO production. For photonic corrections, we use both a fixed order and a
resummation approach. The latter method evades the problem of negative event
weights and automatically includes leading higher order corrections. We present
results for cross sections and event generation for both methods. As a first
step towards a full NLO Monte Carlo, we consider a LO implementation of the
chargino production and subsequent leptonic decay and investigate the precision
of the sneutrino mass determination by means of lepton energy distributions in
chargino decays. The SM and SUSY backgrounds are included in our study using
full matrix elements as well as smearing effects from ISR and beamstrahlung.
Without using energy distribution fits, the sneutrino mass can be determined
with an error in the percent regime.


title:
High sensitivity measurement of 224Ra and 226Ra in water with an
  improved hydrous titanium oxide technique at the Sudbury Neutrino Observatory

abstract:
  The existing hydrous titanium oxide (HTiO) technique for the measurement of
224Ra and 226Ra in the water at the Sudbury Neutrino Observatory (SNO) has been
changed to make it faster and less sensitive to trace impurities in the HTiO
eluate. Using HTiO-loaded filters followed by cation exchange adsorption and
HTiO co-precipitation, Ra isotopes from 200-450 tonnes of heavy water can be
extracted and concentrated into a single sample of a few millilitres with a
total chemical efficiency of 50%. Combined with beta-alpha coincidence
counting, this method is capable of measuring 2.0x10^3 uBq/kg of 224Ra and
3.7x10^3 uBq/kg of 226Ra from the 232Th and 238U decay chains, respectively,
for a 275 tonne D2O assay, which are equivalent to 5x10^16 g Th/g and 3x10^16 g
U/g in heavy water.


title:
Supersymmetry and R-symmetry breaking in models with non-canonical
  Kahler potential

abstract:
  We analyze several aspects of R-symmetry and supersymmetry breaking in
generalized O'Raifeartaigh models with non-canonical Kahler potential. Some
conditions on the Kahler potential are derived in order for the
non-supersymmetric vacua to be degenerate. We calculate the Coleman-Weinberg
(CW) effective potential for general quiral non-linear sigma models and then
study the 1-loop quantum corrections to the pseudo-moduli space. For
R-symmetric models, the quadratic dependence of the CW potential with the
ultraviolet cutoff scale disappears. We also show that the conditions for
R-symmetry breaking are independent of this scale and remain unchanged with
respect to those of canonical models. This is, R-symmetry can be broken when
generic R-charge assignments to the fields are made, while it remains unbroken
when only fields with R-charge 0 and 2 are present. We further show that these
models can keep the runaway behavior of their canonical counterparts and also
new runaway directions can be induced. Due to the runaway directions, the
non-supersymmetric vacua is metastable.


title: The energy output of the Universe from 0.1 micron to 1000 micron

abstract:
  The dominant source of electromagnetic energy in the Universe today (over
ultraviolet, optical and near-infrared wavelengths) is starlight. However,
quantifying the amount of starlight produced has proven difficult due to
interstellar dust grains which attenuate some unknown fraction of the light.
Combining a recently calibrated galactic dust model with observations of 10,000
nearby galaxies we find that (integrated over all galaxy types and
orientations) only (11 +/- 2)% of the 0.1 micron photons escape their host
galaxies; this value rises linearly (with log(lambda)) to (87 +/- 3)% at 2.1
micron. We deduce that the energy output from stars in the nearby Universe is
(1.6+/-0.2) x 10^{35} W Mpc^{-3} of which (0.9+/-0.1) x 10^{35} W Mpc^{-3}
escapes directly into the inter-galactic medium. Some further ramifications of
dust attenuation are discussed, and equations that correct individual galaxy
flux measurements for its effect are provided.


title:
Strong approximation methods in group theory, an LMS/EPSRC Short course
  lecture notes

abstract:
  These are the lecture notes for the LMS/EPSRC short course on strong
approximation methods in linear groups organized by Dan Segal in Oxford in
September 2007.


title:
Effective Properties of Textile Composites: Application of the
  Mori-Tanaka Method

abstract:
  An efficient approach to the evaluation of effective elastic properties of
carbon-carbon plain weave textile composites using the Mori-Tanaka method is
presented. The method proves its potential even if applied to real material
systems with various types of imperfections including the non-uniform waviness
of the fiber-tow paths, both along its longitudinal direction and through the
laminate thickness. Influence of the remaining geometrical parameters is
accounted for by optimal calibration of the shape of the equivalent ellipsoidal
inclusion. An application of the method to a particular sample of the
carbon-carbon composite laminate demonstrates not only its applicability but
also its efficiency particularly when compared to finite element simulations.


title: New twisted quantum deformations of D=4 super-Poincare algebra

abstract:
  We show how some classical r-matrices for the D=4 Poincare algebra can be
supersymmetrized by an addition of part depending on odd supercharges. These
r-matrices for D=4 super-Poincare algebra can be presented as a sum of the
so-called subordinated r-matrices of super-Abelian and super-Jordanian type.
Corresponding twists describing quantum deformations are obtained in an
explicit form. These twists are the super-extensions of twists obtained in the
paper arXiv:0712.3962.


title: Relative differential K-characters

abstract:
  We define a group of relative differential K-characters associated with a
smooth map between two smooth compact manifolds. We show that this group fits
into a short exact sequence as in the non-relative case. Some secondary
geometric invariants are expressed in this theory.


title:
Exchange parameters of copper-based quasi-two-dimensional Heisenberg
  magnets measured using high magnetic fields and muon-spin rotation

abstract:
  Pulsed-field magnetization experiments (fields $B$ of up to 85 T and
temperatures $T$ down to 0.4 K) are reported on nine organic Cu-based
two-dimensional (2D) Heisenberg magnets. All compounds show a low-$T$
magnetization that is concave as a function of $B$, with a sharp ``elbow''
transition to a constant value at a field $B_{\rm c}$. Monte-Carlo simulations
including a finite interlayer exchange energy $J_{\perp}$ quantitatively
reproduce the data; the concavity indicates the effective dimensionality and
$B_{\rm c}$ is an accurate measure of the in-plane exchange energy $J$. Using
these values and Ne\'el temperatures measured by muon-spin rotation, it is also
possible to obtain a quantitative estimate of $|J_{\perp}/J|$. In the light of
these results, it is suggested that in magnets of the form
[Cu(HF$_2$)(pyz)$_2$]X, where X is an anion, the sizes of $J$ and $J_{\perp}$
are controlled by the tilting of the pyrazine (pyz) molecule with respect to
the 2D planes.


title:
Neutronic Design and Measured Performance of the Low Energy Neutron
  Source (LENS) Target Moderator Reflector Assembly

abstract:
  The Low Energy Neutron Source (LENS) is an accelerator-based pulsed cold
neutron facility under construction at the Indiana University Cyclotron
Facility (IUCF). The idea behind LENS is to produce pulsed cold neutron beams
starting with ~MeV neutrons from (p,n) reactions in Be which are moderated to
meV energies and extracted from a small solid angle for use in neutron
instruments which can operate efficiently with relatively broad (~1 msec)
neutron pulse widths. Although the combination of the features and operating
parameters of this source is unique at present, the neutronic design possesses
several features similar to those envisioned for future neutron facilities such
as long-pulsed spallation sources (LPSS) and very cold neutron (VCN) sources.
We describe the underlying ideas and design details of the
target/moderator/reflector system (TMR) and compare measurements of its
brightness, energy spectrum, and emission time distribution under different
moderator configurations with MCNP simulations. Brightness measurements using
an ambient temperature water moderator agree with MCNP simulations within the
20% accuracy of the measurement. The measured neutron emission time
distribution from a solid methane moderator is in agreement with simulation and
the cold neutron flux is sufficient for neutron scattering studies of
materials. We describe some possible modifications to the existing design which
would increase the cold neutron brightness with negligible effect on the
emission time distribution.


title: Average growth of the spectral function on a Riemannian manifold

abstract:
  We study average growth of the spectral function of the Laplacian on a
Riemannian manifold. Two types of averaging are considered: with respect to the
spectral parameter and with respect to a point on a manifold. We obtain as well
related estimates of the growth of the pointwise zeta-function along vertical
lines in the complex plane. Some examples and open problems regarding almost
periodic properties of the spectral function are also discussed.


title:
Reply to "Comment on 'Critique of the foundations of time-dependent
  density functional theory'"

abstract:
  In a recent Comment (arXiv:0710.0018), Maitra, Burke, and van Leeuwen (MBL)
attempt to refute our criticism of the foundations of TDDFT (see Phys. Rev. A
75, 022513 (2007)). However, their arguments miss the essence of our position.
This is mainly due to an ambiguity concerning the meaning of the so-called
mapping derivation of time-dependent Kohn-Sham equations. We distinguish two
different conceptions, referred to as potential-functional based fixed-point
iteration (PF-FPI) and direct Kohn-Sham potential (DKSP) scheme, respectively.
We argue that the DKSP scheme, apparently adopted by MBL, is not a
density-functional method at all. The PF-FPI concept, on the other hand, while
legitimately predicated on the Runge-Gross mapping theorem, is invalid because
the convergence of the fixed-point iteration is not assured.


title:
Dynamical mass generation in QED with magnetic fields: arbitrary field
  strength and coupling constant

abstract:
  We study the dynamical generation of masses for fundamental fermions in
quenched quantum electrodynamics, in the presence of magnetic fields of
arbitrary strength, by solving the Schwinger-Dyson equation (SDE) for the
fermion self-energy in the rainbow approximation. We employ the Ritus
eigenfunction formalism which provides a neat solution to the technical problem
of summing over all Landau levels. It is well known that magnetic fields
catalyze the generation of fermion mass m for arbitrarily small values of
electromagnetic coupling \alpha. For intense fields it is also well known that
m \propto \sqrt eB. Our approach allows us to span all regimes of parameters
\alpha and eB. We find that m \propto \sqrt eB provided \alpha is small.
However, when \alpha increases beyond the critical value \alpha_c which marks
the onslaught of dynamical fermion masses in vacuum, we find m \propto \Lambda,
the cut-off required to regularize the ultraviolet divergences. Our method
permits us to verify the results available in literature for the limiting cases
of eB and \alpha. We also point out the relevance of our work for possible
physical applications.


title:
Universal and nonuniversal contributions to block-block entanglement in
  many-fermion systems

abstract:
  We calculate the entanglement entropy of blocks of size x embedded in a
larger system of size L, by means of a combination of analytical and numerical
techniques. The complete entanglement entropy in this case is a sum of three
terms. One is a universal x and L-dependent term, first predicted by Calabrese
and Cardy, the second is a nonuniversal term arising from the thermodynamic
limit, and the third is a finite size correction. We give an explicit
expression for the second, nonuniversal, term for the one-dimensional Hubbard
model, and numerically assess the importance of all three contributions by
comparing to the entropy obtained from fully numerical diagonalization of the
many-body Hamiltonian. We find that finite-size corrections are very small. The
universal Calabrese-Cardy term is equally small for small blocks, but becomes
larger for x>1. In all investigated situations, however, the by far dominating
contribution is the nonuniversal term steming from the thermodynamic limit.


title: Parity patterns associated with lifts of Hecke groups

abstract:
  Let $q$ be an odd prime, $m$ a positive integer, and let $\Ga_m(q)$ be the
group generated by two elements $x$ and $y$ subject to the relations
$x^{2m}=y^{qm}=1$ and $x^2=y^q$; that is, $\Ga_m(q)$ is the free product of two
cyclic groups of orders $2m$ respectively $qm$, amalgamated along their
subgroups of order $m$. Our main result determines the parity behaviour of the
generalized subgroup numbers of $\Ga_m(q)$ which were defined in [T. W.
M\"uller, Adv. in Math. 153 (2000), 118-154], and which count all the
homomorphisms of index $n$ subgroups of $\Ga_m(q)$ into a given finite group
$H$, in the case when $\gcd(m,| H|)=1$. This computation depends upon the
solution of three counting problems in the Hecke group $\mathfrak
H(q)=C_2*C_q$: (i) determination of the parity of the subgroup numbers of
$\mathfrak H(q)$; (ii) determination of the parity of the number of index $n$
subgroups of $\mathfrak H(q)$ which are isomorphic to a free product of copies
of $C_2$ and of $C_\infty$; (iii) determination of the parity of the number of
index $n$ subgroups in $\mathfrak H(q)$ which are isomorphic to a free product
of copies of $C_q$. The first problem has already been solved in [T. W.
M\"uller, in: {\it Groups: Topological, Combinatorial and Arithmetic Aspects},
(T. W. M\"uller ed.), LMS Lecture Notes Series 311, Cambridge University Press,
Cambridge, 2004, pp. 327-374]. The bulk of our paper deals with the solution of
Problems (ii) and (iii).


title:
Differentiating Neutrino Models on the Basis of $\theta_{13}$ and Lepton
  Flavor Violation

abstract:
  We show how models of neutrino masses and mixings can be differentiated on
the basis of their predictions for $\theta_{13}$ and lepton flavor violation in
radiative charged lepton decays and $\mu - e$ conversion. We illustrate the
lepton flavor violation results for five predictive SO(10) SUSY GUT models and
point out the relative importance of their heavy right-handed neutrino mass
spectra and $\theta_{13}$ predictions.


title: Sector Decomposition

abstract:
  Sector decomposition is a constructive method to isolate divergences from
parameter integrals occurring in perturbative quantum field theory. We explain
the general algorithm in detail and review its application to multi-loop
Feynman parameter integrals as well as infrared divergent phase-space integrals
over real radiation matrix elements.


title:
An approximation formula for holomorphic functions by interpolation on
  the ball

abstract:
  We deal with a problem of the reconstruction of any holomorphic function $f$
on the unit ball of $\mathbb{C}^2$ from its restricions on a union of complex
lines. We give an explicit formula of Lagrange interpolation's type that is
constructed from the knowledge of $f$ and its derivatives on these lines. We
prove that this formula approximates any function when the number of lines
increases. The motivation of this problem comes also from possible applications
in mathematical economics and medical imaging.


title: Two-sided Grassmann-Rayleigh quotient iteration

abstract:
  The two-sided Rayleigh quotient iteration proposed by Ostrowski computes a
pair of corresponding left-right eigenvectors of a matrix $C$. We propose a
Grassmannian version of this iteration, i.e., its iterates are pairs of
$p$-dimensional subspaces instead of one-dimensional subspaces in the classical
case. The new iteration generically converges locally cubically to the pairs of
left-right $p$-dimensional invariant subspaces of $C$. Moreover, Grassmannian
versions of the Rayleigh quotient iteration are given for the generalized
Hermitian eigenproblem, the Hamiltonian eigenproblem and the skew-Hamiltonian
eigenproblem.


title: An Automated Implementation of On-Shell Methods for One-Loop Amplitudes

abstract:
  We present the first results from BlackHat, an automated C++ program for
calculating one-loop amplitudes. The program implements the unitarity method
and on-shell recursion to construct amplitudes. As input to the calculation, it
uses compact analytic formulae for tree amplitudes for four-dimensional
helicity states. The program performs all related computations numerically. We
make use of recently developed on-shell methods for evaluating coefficients of
loop integrals, introducing a discrete Fourier projection as a means of
improving efficiency and numerical stability. We illustrate the numerical
stability of our approach by computing and analyzing six-, seven- and
eight-gluon amplitudes in QCD and comparing against previously-obtained
analytic results.


title: Gas Dynamic Virtual Nozzle for Generation of Microscopic Droplet Streams

abstract:
  As shown by Ganan-Calvo and co-workers, a free liquid jet can be compressed
in iameter through gas-dynamic forces exerted by a co-flowing gas, obviating
the need for a solid nozzle to form a microscopic liquid jet and thereby
alleviating the clogging problems that plague conventional droplet sources of
small diameter. We describe in this paper a novel form of droplet beam source
based on this principle. The source is miniature, robust, dependable, easily
fabricated, and eminently suitable for delivery of microscopic liquid droplets,
including hydrated biological samples, into vacuum for analysis using vacuum
instrumentation. Monodisperse, single file droplet streams are generated by
triggering the device with a piezoelectric actuator. The device is essentially
immune to clogging.


title:
A normalization formula for the Jack polynomials in superspace and an
  identity on partitions

abstract:
  We prove a previously conjectured closed form formula for the norm of the
Jack polynomials in superspace with respect to a certain scalar product. The
proof is mainly combinatorial and relies on the explicit expression in terms of
admissible tableaux of the non-symmetric Jack polynomials. In the final step of
the proof appears an identity on weighted sums of partitions that we
demonstrate using the methods of Gessel-Viennot.


title: Comments on 1/16 BPS Quantum States and Classical Configurations

abstract:
  We formulate the problem of counting 1/16 BPS states of N = 4 Yang Mills
theory as the enumeration of the local cohomology of an operator acting on
holomorphic fields on C^2. We study aspects of the enumeration of this
cohomology at finite N, especially for operators constructed only out of
products of covariant derivatives of scalar fields, and compare our results to
the states obtained from the quantization of giant gravitons and dual giants.
We physically interpret the holomorphic fields that enter our conditions for
supersymmetry semi-classically by deriving a set of Bogomolnyi equations for
1/16-BPS bosonic field configurations in N = 4 Yang Mills theory on R^4 with
reality properties and boundary conditions appropriate to radial quantization.
An arbitrary solution to these equations in the free theory is parameterized by
holomorphic data on C^2 and lifts to a nearby solution of the interacting
Bogomolnyi equations only when the constraints equivalent to Q cohomology are
obeyed.


title: When is sinx+cosx+tanx+cotx+secx+cscx an integer ?

abstract:
  In this paper, we investigate the one-variable equation,
sinx+cosx+tanx+cotx+secx+cscx=n, where n is an integer. We prove that if n lies
between(inclusively) -1 and 6; then the above equation has no real number
solutions. While if n is greater than or equal to 7; or less than or equal to
-2, then the said equation has a nonempty solution set which we describe.


title:
New Results on the Submillimeter Polarization Spectrum of the Orion
  Molecular Cloud

abstract:
  We have used the SHARP polarimeter at the Caltech Submillimeter Observatory
to map the polarization at wavelengths of 350 and 450 micron in a ~2 x 3 arcmin
region of the Orion Molecular Cloud. The map covers the brightest region of the
OMC-1 ridge including the Kleinmann-Low (KL) nebula and the submillimeter
source Orion-south. The ratio of 450-to-350 micron polarization is ~ 1.3 +/-
0.3 in the outer parts of the cloud and drops by a factor of 2 towards KL. The
outer cloud ratio is consistent with measurements in other clouds at similar
wavelengths and confirms previous measurements placing the minimum of the
polarization ratio in dusty molecular clouds at a wavelength ~ 350 micron.


title: Effective pair potentials for spherical nanoparticles

abstract:
  An effective description for spherical nanoparticles in a fluid of point
particles is presented. The points inside the nanoparticles and the point
particles are assumed to interact via spherically symmetric additive pair
potentials, while the distribution of points inside the nanoparticles is taken
to be spherically symmetric and smooth. The resulting effective pair
interactions between a nanoparticle and a point particle, as well as between
two nanoparticles, are then given by spherically symmetric potentials. If
overlap between particles is allowed, the effective potential generally has
non-analytic points, but for each effective potential the expressions for
different overlapping cases can be written in terms of one analytic auxiliary
potential. Effective potentials for hollow nanoparticles (appropriate e.g. for
buckyballs) are also considered, and shown to be related to those for solid
nanoparticles. Finally, explicit expressions are given for the effective
potentials derived from basic pair potentials of power law and exponential
form, as well as from the commonly used London-Van der Waals, Morse,
Buckingham, and Lennard-Jones potential. The applicability of the latter is
demonstrated by comparison with an atomic description of nanoparticles with an
internal face centered cubic structure.


title:
Gaussian approximation to single particle correlations at and below the
  picosecond scale for Lennard-Jones and nanoparticle fluids

abstract:
  To describe short-time (picosecond) and small-scale (nanometre) transport in
fluids, a Green's function approach was recently developed. This approach
relies on an expansion of the distribution of single particle displacements
around a Gaussian function, yielding an infinite series of correction terms.
Applying a recent theorem [Van Zon and Cohen, J. Stat. Phys. 123, 1-37 (2006)]
shows that for sufficiently small times the terms in this series become
successively smaller, so that truncating the series near or at the Gaussian
level might provide a good approximation. In the present paper, we derive a
theoretical estimate for the time scale at which truncating the series at or
near the Gaussian level could be supposed to be accurate for equilibrium
nanoscale systems. In order to numerically estimate this time scale, the
coefficients for the first few terms in the series are determined in computer
simulations for a Lennard-Jones fluid, an isotopic Lennard-Jones mixture and a
suspension of a Lennard-Jones-based model of nanoparticles in a Lennard-Jones
fluid. The results suggest that for Lennard-Jones fluids an expansion around a
Gaussian is accurate at time scales up to a picosecond, while for nanoparticles
in suspension (a nanofluid), the characteristic time scale up to which the
Gaussian is accurate becomes of the order of five to ten picoseconds.


title:
Cohomological gauge theory, quiver matrix models and Donaldson-Thomas
  theory

abstract:
  We study the relation between Donaldson-Thomas theory of Calabi-Yau
threefolds and a six-dimensional topological Yang-Mills theory. Our main
example is the topological U(N) gauge theory on flat space in its Coulomb
branch. To evaluate its partition function we use equivariant localization
techniques on its noncommutative deformation. As a result the gauge theory
localizes on noncommutative instantons which can be classified in terms of
N-coloured three-dimensional Young diagrams. We give to these noncommutative
instantons a geometrical description in terms of certain stable framed coherent
sheaves on projective space by using a higher-dimensional generalization of the
ADHM formalism. From this formalism we construct a topological matrix quantum
mechanics which computes an index of BPS states and provides an alternative
approach to the six-dimensional gauge theory.


title: Atomic Zitterbewegung

abstract:
  Ultra-cold atoms which are subject to ultra-relativistic dynamics are
investigated. By using optically induced gauge potentials we show that the
dynamics of the atoms is governed by a Dirac type equation. To illustrate this
we study the trembling motion of the centre of mass for an effective two level
system, historically called Zitterbewegung. Its origin is described in detail,
where in particular the role of the finite width of the atomic wave packets is
seen to induce a damping of both the centre of mass dynamics and the dynamics
of the populations of the two levels.


title:
Chiral potentials, perturbation theory, and the 1S0 channel of NN
  scattering

abstract:
  We use nucleon-nucleon phase shifts obtained from experimental data, together
with the chiral expansion for the long-distance part of the NN interaction, to
obtain information about the short-distance piece of the NN potential that is
at work in the 1S0 channel. We find that if the scale R that defines the
separation between "long-" and "short-" distance is chosen to be \lsim 1.8 fm
then the energy dependence produced by short-distance dynamics is well
approximated by a two-term polynomial for Tlab < 200 MeV. We also find that a
quantitative description of NN dynamics is possible, at least in this channel,
if one treats the long-distance parts of the chiral NN potential in
perturbation theory. However, in order to achieve this we have to choose a
separation scale R that is larger than 1.0 fm.


title: A simple BRST system with quadratically constrained ghosts

abstract:
  I present a toy model for the Berkovits pure spinor superparticle. It is a
D=1, N=2 superparticle with no physical degrees of freedom. We study the
cohomology in various ways, in particular finding an explicit expression for
the `b'-field. Finally, we construct the topological string B-model from a
straightforward generalization of the system.


title: Quark Mass Deformation of Holographic Massless QCD

abstract:
  We propose several quark mass deformations of the holographic model of
massless QCD using the D4/D8/D8bar brane configuration proposed by Sakai and
Sugimoto. The deformations are based on introducing additional D4 or D6 branes
away from the QCD D4 branes. The idea is similar to extended technicolor
theories, where the chiral symmetry breaking by additional D-branes are
mediated to QCD to induce non-zero quark masses. In the D-brane picture as well
as the holographic dual gravity description, the quark and the pion masses are
generated by novel worldsheet instantons with finite area. We also derive the
Gell-Mann-Oakes-Renner relation, and find the value of the chiral condensate in
the Sakai-Sugimoto model.


title:
General relativistic simulations of magnetized binary neutron star
  mergers

abstract:
  Binary neutron stars (NSNS) are expected to be among the leading sources of
gravitational waves observable by ground-based laser interferometers and may be
the progenitors of short-hard gamma ray bursts. We present a series of general
relativistic NSNS coalescence simulations both for unmagnetized and magnetized
stars. We adopt quasiequilibrium initial data for circular, irrotational
binaries constructed in the conformal thin-sandwich (CTS) framework. We adopt
the BSSN formulation for evolving the metric and a high-resolution
shock-capturing scheme to handle the magnetohydrodynamics. Our simulations of
unmagnetized binaries confirm the results of Shibata, Taniguchi and Uryu
(2003). In cases in which the mergers result in a prompt collapse to a black
hole, we are able to use puncture gauge conditions to extend the evolution and
determine the mass of the material that forms a disk. We find that the disk
mass is less than 2% of the total mass in all cases studied. We then add a
small poloidal magnetic field to the initial configurations and study the
subsequent evolution. For cases in which the remnant is a hypermassive neutron
star, we see measurable differences in both the amplitude and phase of the
gravitational waveforms following the merger. For cases in which the remnant is
a black hole surrounded by a disk, the disk mass and the gravitational
waveforms are about the same as the unmagnetized cases. Magnetic fields
substantially affect the long-term, secular evolution of a hypermassive neutron
star (driving `delayed collapse') and an accretion disk around a nascent black
hole.


title: Weak Lensing of the Primary CMB Bispectrum

abstract:
  The cosmic microwave background (CMB) bispectrum is a well-known probe of the
non-Gaussianity of primordial perturbations. Just as the intervening
large-scale structure modifies the CMB angular power spectrum through weak
gravitational lensing, the CMB primary bispectrum generated at the last
scattering surface is also modified by lensing. We discuss the lensing
modification to the CMB bispectrum and show that lensing leads to an overall
decrease in the amplitude of the primary bispectrum at multipoles of interest
between 100 and 2000 through additional smoothing introduced by lensing. Since
weak lensing is not accounted for in current estimators of the primordial
non-Gaussianity parameter, the existing measurements of $f_{\rm NL}$ of the
local model with WMAP out to $l_{\rm max} \sim 750$ is biased low by about 6%.
For a high resolution experiment such as Planck, the lensing modification to
the bispectrum must be properly included when attempting to estimate the
primordial non-Gaussianity or the bias will be at the level of 30%. For Planck,
weak lensing increases the minimum detectable value for the non-Gaussianity
parameter of the local type $f_{\rm NL}$ to 7 from the previous estimate of
about 5 without lensing. The minimum detectable value of $f_{\rm NL}$ for a
cosmic variance limited experiment is also increased from less than 3 to $\sim$
5.


title: Supercritical Coulomb Impurities in Gapped Graphene

abstract:
  We study the problem of Coulomb field-induced charging of the ground state in
a system of 2D massive Dirac particles (gapped graphene). As in its 3D QED
counterpart, the critical Coulomb coupling is renormalized to higher values,
compared to the massless case. We find that in gapped graphene a novel
supercritical regime is possible, where the screening charge is comparable to
the impurity charge, thus leading to suppression of the Coulomb field at
nanometer scales. We corroborate this with numerical solution of the
tight-binding problem in the honeycomb lattice.


title:
The WIMPless Miracle: Dark Matter Particles without Weak-scale Masses or
  Weak Interactions

abstract:
  We propose that dark matter is composed of particles that naturally have the
correct thermal relic density, but have neither weak-scale masses nor weak
interactions. These WIMPless models emerge naturally from gauge-mediated
supersymmetry breaking, where they elegantly solve the dark matter problem. The
framework accommodates single or multiple component dark matter, dark matter
masses from 10 MeV to 10 TeV, and interaction strengths from gravitational to
strong. These candidates enhance many direct and indirect signals relative to
WIMPs and have qualitatively new implications for dark matter searches and
cosmological implications for colliders.


title:
Optimization of Enzymatic Biochemical Logic for Noise Reduction and
  Scalability: How Many Biocomputing Gates Can Be Interconnected in a Circuit?

abstract:
  We report an experimental evaluation of the "input-output surface" for a
biochemical AND gate. The obtained data are modeled within the rate-equation
approach, with the aim to map out the gate function and cast it in the language
of logic variables appropriate for analysis of Boolean logic for scalability.
In order to minimize "analog" noise, we consider a theoretical approach for
determining an optimal set for the process parameters to minimize "analog"
noise amplification for gate concatenation. We establish that under optimized
conditions, presently studied biochemical gates can be concatenated for up to
order 10 processing steps. Beyond that, new paradigms for avoiding noise
build-up will have to be developed. We offer a general discussion of the ideas
and possible future challenges for both experimental and theoretical research
for advancing scalable biochemical computing.

categories: q-bio.MN cond-mat.other cond-mat.soft cs.CC q-bio.BM q-bio.OT q-bio.QM quant-ph


title: On the Enhancement of Mass Loss in Cepheids Due to Radial Pulsation

abstract:
  An analytical derivation is presented for computing mass-loss rates of
Cepheids by using the method of Castor, Abbott, & Klein (1975) modified to
include a term for momentum input from pulsation and shocks generated in the
atmosphere. Using this derivation, mass-loss rates of Cepheids are determined
as a function of stellar parameters. When applied to a set of known Cepheids,
the calculated mass-loss rates range from 10^{-10} to 10^{-7}M_{Sun}/yr, larger
than if the winds were driven by radiation alone. Infrared excesses based on
the predicted mass-loss rates are compared to observations from optical
interferometry and IRAS, and predictions are made for Spitzer observations. The
mass-loss rates are consistent with the observations, within the uncertainties
of each. The rate of period change of Cepheids is discussed and shown to relate
to mass loss, albeit the dependence is very weak. There is also a correlation
between the large mass-loss rates and the Cepheids with slowest absolute rate
of period change due to evolution through the instability strip. The enhanced
mass loss helps illuminate the issue of infrared excess and the mass
discrepancy found in Cepheids.


title: Correlations between O VI Absorbers and Galaxies at Low Redshift

abstract:
  We investigate the relationship between galaxies and metal-line absorption
systems in a large-scale cosmological simulation with galaxy formation. Our
detailed treatment of metal enrichment and non-equilibrium calculation of
oxygen species allow us, for the first time, to carry out quantitative
calculations of the cross-correlations between galaxies and O VI absorbers. We
find the following: (1) The cross-correlation strength depends weakly on the
absorption strength but strongly on the luminosity of the galaxy. (2) The
correlation distance increases monotonically with luminosity from ~0.5-1h^-1
Mpc for 0.1L* galaxies to ~3-5h^-1 Mpc for L* galaxies. (3) The correlation
distance has a complicated dependence on absorber strength, with a
luminosity-dependent peak. (4) Only 15% of O VI absorbers lie near >=Lz*
galaxies. The remaining 85%, then, must arise ``near'' lower-luminosity
galaxies, though, the positions of those galaxies is not well-correlated with
the absorbers. This may point to pollution of intergalactic gas predominantly
by smaller galaxies. (5) There is a subtle trend that for >~0.5Lz* galaxies,
there is a positive correlation between absorber strength and galaxy luminosity
in the sense that stronger absorbers have a slightly higher probability of
finding such a large galaxy at a given projection distance. For less luminous
galaxies, there seems to be a negative correlation between luminosity and
absorber strength.


title: Bounded excursion stable gravastars and black holes

abstract:
  Dynamical models of prototype gravastars were constructed in order to study
their stability. The models are the Visser-Wiltshire three-layer gravastars, in
which an infinitely thin spherical shell of stiff fluid divides the whole
spacetime into two regions, where the internal region is de Sitter, and the
external is Schwarzschild. It is found that in some cases the models represent
the "bounded excursion" stable gravastars, in which the thin shell is
oscillating between two finite radii, while in other cases they collapse until
the formation of black holes. In the phase space, the region for the ``bounded
excursion" gravastars is very small in comparison to that of black holes, but
not empty. Therefore, although the existence of gravastars cannot be excluded
from such dynamical models, our results do indicate that, even if gravastars
indeed exist, they do not exclude the existence of black holes.


title: Three Natural Generalizations of Fedosov Quantization

abstract:
  Fedosov's simple geometrical construction for deformation quantization of
symplectic manifolds is generalized in three ways without introducing new
variables: (1) The base manifold is allowed to be a supermanifold. (2) The star
product does not have to be of Weyl/symmetric or Wick/normal type. (3) The
initial geometric structures are allowed to depend on Planck's constant.


title: Anomalies in Fermionic UV Completions of Little Higgs Models

abstract:
  We consider fermionic UV completions of little Higgs models and their
associated T-parity violating anomalous vertices. In particular, we investigate
strategies to avoid such parity-violating anomalies. We show that it is
unlikely a QCD-like UV completion could be used to implement a model with
anomaly-free global symmetry groups. This is because the vacuum state is
unlikely to achieve the necessary alignment. However, we will see that certain
multi-link moose models, although anomalous, possess a modified form of
T-parity that leads to a stable particle. Finally, we briefly discuss a
discriminant for detecting anomalous decays at colliders.


title:
New High Proper Motion Stars from the Digitized Sky Survey. IV.
  Completion of the Southern Survey and 170 Additional Stars with pm>0.45
  arcsec/yr

abstract:
  Completion of the SUPERBLINK proper motion survey in the southern celestial
hemisphere has turned up 170 new stars with proper motion 0.45 arcsec/yr < pm <
2.0 arcsec/yr. This fourth and final installment completes the all-sky,
data-mining of the Digitized Sky Surveys for stars with large proper motions.
The areas investigated in this final installment comprise 11,600 square degrees
in the declination range -30 degrees < Decl. <0 degrees, and in low galactic
latitude areas south of Decl.= -30 degrees which had not been covered in
earlier data releases. Astrometric and photometric data are provided for the
170 new stars, along with finder charts. Most of the new discoveries are found
in densely populated fields along the Milky Way, towards the Galactic
bulge/center. The list of new discoveries includes 4 stars with proper motion
pm >1.0 arcsec/yr. The total list of high proper motion stars recovered by
SUPERBLINK in the southern sky now includes 2,228 stars with proper motions
0.45 arcsec/yr < pm <2.0 arcsec/yr.


title:
Classical-Quantum Mappings for Geometrically Frustrated Systems: Spin
  Ice in a [100] Field

abstract:
  Certain classical statistical systems with strong local constraints are known
to exhibit Coulomb phases, where long-range correlation functions have
power-law forms. Continuous transitions from these into ordered phases cannot
be described by a naive application of the Landau-Ginzburg-Wilson theory, since
neither phase is thermally disordered. We present an alternative approach to a
critical theory for such systems, based on a mapping to a quantum problem in
one fewer spatial dimensions. We apply this method to spin ice, a magnetic
material with geometrical frustration, which exhibits a Coulomb phase and a
continuous transition to an ordered state in the presence of a magnetic field
applied in the [100] direction.


title: Multi-channel Kondo Models in non-Abelian Quantum Hall Droplets

abstract:
  We study the coupling between a quantum dot and the edge of a non-Abelian
fractional quantum Hall state which is spatially separated from it by an
integer quantum Hall state. Near a resonance, the physics at energy scales
below the level spacing of the edge states of the dot is governed by a
$k$-channel Kondo model when the quantum Hall state is a Read-Rezayi state at
filling fraction $\nu=2+k/(k+2)$ or its particle-hole conjugate at
$\nu=2+2/(k+2)$. The $k$-channel Kondo model is channel isotropic even without
fine tuning in the former state; in the latter, it is generically channel
anisotropic. In the special case of $k=2$, our results provide a new venue,
realized in a mesoscopic context, to distinguish between the Pfaffian and
anti-Pfaffian states at filling fraction $\nu=5/2$.