title:
d-wave Superconductivity, Orbital Magnetism, and Unidirectional Charge
  Order in the t-J Model

abstract:
  Recent scanning tunneling microscopy in the superconducting regime of two
different cuprate families has revealed unidirectional bond-centered modulation
in the local electronic density of states. Motivated by this result we
investigate the emergence of modulated d-wave superconductivity coexisting with
charge domains that form along one of the crystal axes. While detailed stripe
profiles depend on the used form of the Gutzwiller factors, the tendency
towards a valence bond crystal remain robust. We also find closely related
stripe phase originating from the staggered flux phase, a candidate for the
pseudogap phase of lightly doped cuprates.


title:
GRB 071003: Broadband Follow-up Observations of a Very Bright Gamma-Ray
  Burst in a Galactic Halo

abstract:
  The optical afterglow of long-duration GRB 071003 is among the brightest yet
to be detected from any GRB, with R ~ 12 mag in KAIT observations starting 42 s
after the GRB trigger, including filtered detections during prompt emission.
However, our high S/N ratio afterglow spectrum displays only extremely weak
absorption lines at what we argue is the host redshift of z = 1.60435 - in
contrast to the three other, much stronger Mg II absorption systems observed at
lower redshifts. Together with Keck adaptive optics observations which fail to
reveal a host galaxy coincident with the burst position, our observations
suggest a halo progenitor and offer a cautionary tale about the use of Mg II
for GRB redshift determination. We present early through late-time observations
spanning the electromagnetic spectrum, constrain the connection between the
prompt emission and early variations in the light curve (we observe no
correlation), and discuss possible origins for an unusual, marked rebrightening
that occurs a few hours after the burst: likely either a late-time refreshed
shock or a wide-angle secondary jet. Analysis of the late-time afterglow is
most consistent with a wind environment, suggesting a massive star progenitor.
Together with GRB 070125, this may indicate that a small but significant
portion of star formation in the early universe occurred far outside what we
consider a normal galactic disk.


title: Investigating gluino production at the LHC

abstract:
  Gluinos are expected to be one of the most massive sparticles (supersymmetric
partners of usual particles) which constitute the Minimal Supersymmetric
Standard Model (MSSM). The gluinos are the partners of the gluons and they are
color octet fermions, due this fact they can not mix with the other particles.
Therefore in several scenarios, given at SPS convention, they are the most
massive particles and their nature is a Majorana fermion. Therefore their
production is only feasible at a very energetic machine such as the Large
Hadron Collider (LHC). Being the fermion partners of the gluons, their role and
interactions are directly related with the properties of the supersymmetric QCD
(sQCD). We review the mechanisms for producing gluinos at the LHC and
investigate the total cross section and differential distributions, making an
analysis of their uncertainties, such as the gluino and squark masses, as
obtained in several scenarios, commenting on the possibilities of
discriminating among them.


title: An Eccentric Binary Millisecond Pulsar in the Galactic Plane

abstract:
  Binary pulsar systems are superb probes of stellar and binary evolution and
the physics of extreme environments. In a survey with the Arecibo telescope, we
have found PSR J1903+0327, a radio pulsar with a rotational period of 2.15 ms
in a highly eccentric (e = 0.44) 95-day orbit around a solar mass companion.
Infrared observations identify a possible main-sequence companion star.
Conventional binary stellar evolution models predict neither large orbital
eccentricities nor main-sequence companions around millisecond pulsars.
Alternative formation scenarios involve recycling a neutron star in a globular
cluster then ejecting it into the Galactic disk or membership in a hierarchical
triple system. A relativistic analysis of timing observations of the pulsar
finds its mass to be 1.74+/-0.04 Msun, an unusually high value.


title:
Photon-number-resolution with sub-30-ps timing using multi-element
  superconducting nanowire single photon detectors

abstract:
  A photon-number-resolving detector based on a four-element superconducting
nanowire single photon detector is demonstrated to have sub-30-ps resolution in
measuring the arrival time of individual photons. This detector can be used to
characterize the photon statistics of non-pulsed light sources and to mitigate
dead-time effects in high-speed photon counting applications. Furthermore, a
25% system detection efficiency at 1550 nm was demonstrated, making the
detector useful for both low-flux source characterization and high-speed
photon-counting and quantum communication applications. The design, fabrication
and testing of this detector are described, and a comparison between the
measured and theoretical performance is presented.


title: Missing energy look-alikes with 100 pb-1 at the LHC

abstract:
  A missing energy discovery is possible at the LHC with the first 100 pb-1 of
understood data. We present a realistic strategy to rapidly narrow the list of
candidate theories at, or close to, the moment of discovery. The strategy is
based on robust ratios of inclusive counts of simple physics objects. We study
specific cases showing discrimination of look-alike models in simulated data
sets that are at least 10 to 100 times smaller than used in previous studies.
We discriminate supersymmetry models from non-supersymmetric look-alikes with
only 100 pb-1 of simulated data, using combinations of observables that trace
back to differences in spin.


title: XO-5b: A Transiting Jupiter-sized Planet With A Four Day Period

abstract:
  The star XO-5 (GSC 02959-00729, V=12.1, G8V) hosts a Jupiter-sized,
Rp=1.15+/-0.12 Rjup, transiting extrasolar planet, XO-5b, with an orbital
period of P=4.187732+/-0.00002 days. The planet mass (Mp=1.15+/-0.08 Mjup) and
surface gravity (gp=22+/-5 m/s^2) are significantly larger than expected by
empirical Mp-P and Mp-P-[Fe/H] relationships. However, the deviation from the
Mp-P relationship for XO-5b is not large enough to suggest a distinct type of
planet as is suggested for GJ 436b, HAT-P-2b, and XO-3b. By coincidence XO-5
overlies the extreme H I plume that emanates from the interacting galaxy pair
NGC 2444/NGC 2445 (Arp 143).


title: Unidirectional Charge Instability of the d-wave RVB Superconductor

abstract:
  Starting from a uniform d-wave superconducting phase we study the energy cost
due to imposed unidirectional defects with a vanishing pairing amplitude. Both
renormalized mean-field theory and variational Monte Carlo calculations within
the t-J model yield that the energies of inhomogeneous and uniform phases are
very close to each other. This suggests that small perturbations in the
microscopic Hamiltonian, might lead to inhomogeneous superconducting phases in
real materials as observed in recent scanning tunneling microscopy on
Ca_{2-x}Na_xCuO_2Cl_2.


title:
The antipode of a dual quasi-Hopf algebra with nonzero integrals is
  bijective

abstract:
  For $A$ a Hopf algebra of arbitrary dimension over a field $K$, it is
well-known that if $A$ has nonzero integrals, or, in other words, if the
coalgebra $A$ is co-Frobenius, then the space of integrals is one-dimensional
and the antipode of $A$ is bijective. Bulacu and Caenepeel recently showed that
if $H$ is a dual quasi-Hopf algebra with nonzero integrals, then the space of
integrals is one-dimensional, and the antipode is injective. In this short note
we show that the antipode is bijective.


title: Vanishing viscosity and the accumulation of vorticity on the boundary

abstract:
  We say that the vanishing viscosity limit holds in the classical sense if the
velocity for a solution to the Navier-Stokes equations converges in the energy
norm uniformly in time to the velocity for a solution to the Euler equations.
We prove, for a bounded domain in dimension 2 or higher, that the vanishing
viscosity limit holds in the classical sense if and only if a vortex sheet
forms on the boundary.


title: Local recognition of reflection graphs on Coxeter groups

abstract:
  We provide local recognition results for the reflection graphs on spherical
Coxeter groups. In particular, we study the case $F_4$ which is locally
recognizable under additional constraints only. It is then demonstrated in the
cases $A_n$ and $F_4$ how these graph theoretical recognition results can be
used to characterize the corresponding Coxeter groups in terms of their
reflection centralizers. Finally, we outline the connection to the local
recognition of Chevalley groups which is particularly important in the
classification of the finite simple groups.


title: Baryons from quarks in curved space and deconfinement

abstract:
  Detailed account is given of the fact that the Cornell potential predicted by
Lattice QCD and its exactly solvable trigonometric extension recently reported
by us can be viewed as the respective approximate and exact counterparts on a
curved space to an 1/r flat space potential. The "curved" potential describes a
confinement phenomenon because it is of infinite depth and has only bound
states. It furthermore has the remarkable property of preserving both the SO(4)
and SO(2,1) symmetries of the ordinary 1/r potential. We first make the case
that this particular geometric version on confinement provides a remarkably
adequate description of both nucleon and Delta spectra and the proton mean
square charge radius as well, and suggests an intriguing venue toward quark
deconfinement as shut-down of the curvature considered as temperature
dependent. Next we observe that the SO(2,1) symmetry of the "curved" potential
allows to place it within the context of AdS_5/CFT correspondence and to
establish in this manner the algbraic link of the the latter to QCD
potentiology.


title: Wave instabilities in an anisotropic magnetized space plasma

abstract:
  We study wave instability in an collisionless, rarefied hot plasma (e.g.
solar wind or corona). We consider the anisotropy produced by the magnetic
field, when the thermal gas pressures across and along the field become
unequal. We apply the 16-moment transport equations (obtained from the
Boltzmann-Vlasov kinetic equation) including the anisotropic thermal fluxes.
The general dispersion relation for the incompressible wave modes is derived.
It is shown that a new, more complex wave spectrum with stable and unstable
behavior is possible, in contrast to the classic fire-hose modes obtained in
terms of the 13-moment integrated equations.


title: Resonant Activation in Asymmetric Potentials

abstract:
  The resonant activation effect (RA) has been well studied in different ways
during the last two decades. It consists in the presence of a minimum in the
mean time spent by a Brownian particle to exit from a potential well in the
presence of a fluctuating external force, as a function of the mean frequency
(or the correlation time) of the latter. This work studies the role played by
the asymmetry of a piecewise linear potential in the RA effect, and, in
general, the behavior of the mean first passage time and the mean velocity of
the particle crossing through the potential barrier. A strong dependence on the
asymmetry of the potential has been found which can be put in relationship with
the current in the ratchet whose the potential here used is an elementary
module. In this case a current reversal as a function of the frequency of the
switching potential occurs. Comparison of the calculations with the
Doering-Gadua model have been performed, as well as comparison with smooth
symmetrical potentials, by checking for the robustness of the resonant
correlation time. The calculations have been done by solving numerically the
Langevin equation in the presence of an uncorrelated Gaussian noise. The
resonant mean first passage times show an unexpected behavior as a function of
the thermal noise intensity. The related curves present for the different
symmetries an unexpected inversion of their relative behavior beyond a certain
threshold value of the noise. This means that the current reversal can only
occur for weak noise intensities, lower than that threshold value.


title: Multi-spin errors in the optical control of a spin quantum memory

abstract:
  We study a quantum memory composed of an array of charged quantum dots
embedded in a planar cavity. Optically excited polaritons, i.e. exciton-cavity
mixed states, interact with the electron spins in the dots. Linearly polarized
excitation induces two-spin and multi-spin interactions. We discuss how the
multi-spin interaction terms, which represent a source of errors for two-qubit
quantum gates, can be suppressed using local control of the exciton energy. We
show that using detuning conditional phase shift gates with high fidelity can
be obtained. The cavity provides long-range spin coupling and the resulting
gate operation time is shorter than the spin decoherence time.


title:
Measurements of B --> {pi, eta, eta'} l nu Branching Fractions and
  Determination of |Vub| with Semileptonically Tagged B Mesons

abstract:
  We report measurements of branching fractions for the decays B --> P l nu,
where P are the pseudoscalar charmless mesons pi-, pi0, eta and eta', based on
348 fb-1 of data collected with the BABAR detector, using B0 and B+ mesons
found in the recoil of a second B meson decaying as B --> D(*) l nu. Assuming
isospin symmetry, we combine pionic branching fractions to obtain B(B0 --> pi-
l+ nu) = (1.54 +/- 0.17(stat) +/- 0.09(syst)) x 10-4; we find 3.2 sigma
evidence of the decay B+ --> eta l+ nu and measure its branching fraction to be
(0.64 +/- 0.20 (stat) +/- 0.03 (syst)) x 10-4, and determine B(B+ --> eta' l+
nu) < 0.47 x 10-4 to 90% confidence level. Using partial branching fractions
for the pionic decays in ranges of the momentum transfer and a recent form
factor calculation, we obtain the magnitude of the Cabibbo-Kobayashi-Maskawa
matrix element |Vub| = (4.0 +/- 0.5(stat) +/- 0.2(syst) +0.7-0.5(theory)) x
10-3.


title: Shoikhet's Conjecture and Duflo Isomorphism on (Co)Invariants

abstract:
  In this paper we prove a conjecture of B. Shoikhet. This conjecture states
that the tangent isomorphism on homology, between the Poisson homology
associated to a Poisson structure on $\mathbb{R}^d$ and the Hochschild homology
of its quantized star-product algebra, is an isomorphism of modules over the
(isomorphic) respective cohomology algebras. As a consequence, we obtain a
version of the Duflo isomorphism on coinvariants.


title: On knots with infinite smooth concordance order

abstract:
  We use the Heegaard Floer obstructions defined by Grigsby, Ruberman, and
Strle to show that forty-six of the sixty-seven knots through eleven crossings
whose concordance orders were previously unknown have infinite concordance
order.


title:
A geometric construction of the Riemann scalar curvature in Regge
  calculus

abstract:
  The Riemann scalar curvature plays a central role in Einstein's geometric
theory of gravity. We describe a new geometric construction of this scalar
curvature invariant at an event (vertex) in a discrete spacetime geometry. This
allows one to constructively measure the scalar curvature using only clocks and
photons. Given recent interest in discrete pre-geometric models of quantum
gravity, we believe is it ever so important to reconstruct the curvature scalar
with respect to a finite number of communicating observers. This derivation
makes use of a new fundamental lattice cell built from elements inherited from
both the original simplicial (Delaunay) spacetime and its circumcentric dual
(Voronoi) lattice. The orthogonality properties between these two lattices
yield an expression for the vertex-based scalar curvature which is strikingly
similar to the corresponding hinge-based expression in Regge calculus (deficit
angle per unit Voronoi dual area). In particular, we show that the scalar
curvature is simply a vertex-based weighted average of deficits per weighted
average of dual areas.


title: Detection Confidence Tests for Burst and Inspiral Candidate Events

abstract:
  The LIGO Scientific Collaboration (LSC) is developing and running analysis
pipelines to search for gravitational-wave transients emitted by astrophysical
events such as compact binary mergers or core-collapse supernovae. However,
because of the non-Gaussian, non-stationary nature of the noise exhibited by
the LIGO detectors, residual false alarms might be found at the end of the
pipelines. A critical aspect of the search is then to assess our confidence for
gravitational waves and to distinguish them from those false alarms. Both the
'Compact Binary Coalescence' and the 'Burst' working groups have been
developing a detection checklist for the validation of candidate-events,
consisting of a series of tests which aim to corroborate a detection or to
eliminate a false alarm. These tests include for example data quality checks,
analysis of the candidate appearance, parameter consistency studies and
coherent analysis. In this paper, the general methodology used for candidate
validation is presented. The method is illustrated with an example of simulated
gravitational-wave signal and a false alarm.


title: Quantum spin models with electrons in Penning traps

abstract:
  We propose a scheme to engineer an effective spin Hamiltonian starting from a
system of electrons confined in micro-Penning traps. By means of appropriate
sequences of electromagnetic pulses, alternated to periods of free evolution,
we control the shape and strength of the spin-spin interaction. Moreover, we
can modify the effective magnetic field experienced by the particle spin. This
procedure enables us to reproduce notable quantum spin systems, such as Ising
and XY models. Thanks to its scalability, our scheme can be applied to a fairly
large number of trapped particles within the reach of near future technology.


title:
Area dependence of interlayer tunneling in strongly correlated bilayer
  2D electron systems at $\nu_T=1$

abstract:
  The area and perimeter dependence of the Josephson-like interlayer tunneling
signature of the coherent $\nu_T=1$ quantum Hall phase in bilayer
two-dimensional electron systems is examined. Electrostatic top gates of
various sizes and shapes are used to locally define distinct $\nu_T=1$ regions
in the same sample. Near the phase boundary with the incoherent $\nu_T=1$ state
at large layer separation, our results demonstrate that the tunneling
conductance in the coherent phase is closely proportional to the total area of
the tunneling region. This implies that tunneling at $\nu_T=1$ is a bulk
phenomenon in this regime.


title:
Superconducting energy gap and c-axis plasma frequency of
  (Nd,Sm)O0.82F0.18FeAs superconductors from infrared ellipsometry

abstract:
  We present ellipsometric measurements of the far-infrared dielectric response
of polycrystalline samples of the new pnictide superconductor RO0.82F0.18FeAs
(R=Nd and Sm). We find evidence that the electronic properties are strongly
anisotropic such that the optical spectra are dominated by the weakly
conducting c-axis response similar as in the cuprate high-temperature
superconductors (HTSC). Accordingly, we obtain an upper limit of the c-axis
superconducting plasma frequency of $\omega_{{\rm pl},c}^{\rm SC}\leq 260\cm$
which corresponds to a lower limit of the c-axis magnetic penetration depth of
$\lambda_c\geq6\mum$ and an anisotropy of $\lambda_c/\lambda_{ab}\geq 30$ as
compared to $\lambda_{ab}=185$ nm from muon spin rotation [A. Drew {\it et
al.}, arXiv:0805.1042]. Also in analogy to the cuprate HTSC, our spectra
exhibit the signatures of a gap-like suppression of the conductivity in the
superconducting state with a large gap magnitude of $2\Delta\approx300\cm$ (37
meV) and a ratio of $2\Delta/k_{\rm B}\tc\approx8$ that is suggestive of strong
coupling.


title: Eulerian quasisymmetric functions and poset topology

abstract:
  We introduce a family of quasisymmetric functions called {\em Eulerian
quasisymmetric functions}, which have the property of specializing to
enumerators for the joint distribution of the permutation statistics, major
index and excedance number on permutations of fixed cycle type. This family is
analogous to a family of quasisymmetric functions that Gessel and Reutenauer
used to study the joint distribution of major index and descent number on
permutations of fixed cycle type. Our central result is a formula for the
generating function for the Eulerian quasisymmetric functions, which
specializes to a new and surprising $q$-analog of a classical formula for the
exponential generating function of the Eulerian polynomials. This $q$-analog
computes the joint distribution of excedance number and major index, the only
of the four important Euler-Mahonian distributions that had not yet been
computed. Our study of the Eulerian quasisymmetric functions also yields
results that include the descent statistic and refine results of Gessel and
Reutenauer. We also obtain $q$-analogs, $(q,p)$-analogs and quasisymmetric
function analogs of classical results on the symmetry and unimodality of the
Eulerian polynomials. Our Eulerian quasisymmetric functions refine symmetric
functions that have occurred in various representation theoretic and
enumerative contexts such as in MacMahon's study of multiset derangements, in
work of Procesi and Stanley on toric varieties of Coxeter complexes and in
Stanley's work on symmetric chromatic polynomials. Here we present yet another
occurence in connection with the homology of a poset introduced by Bj\"orner
and Welker.


title:
Special Relativity and possible Lorentz violations consistently coexist
  in Aristotle space-time

abstract:
  Some studies interpret quantum measurement as being explicitly non local.
Others assume the preferred frame hypothesis. Unfortunately, these two classes
of studies conflict with Minkowski space-time geometry. On the contrary, in
Aristotle space-time, Lorentz invariance, interpreted as a physical property
applying to all phenomena actually satisfying this symmetry (as opposed to a
geometrical constraint applying to an assumed pre-existing Minkowski
space-time) consistently coexists with possible Lorentz violations. Moreover,
as will be pointed out, the geometrical framework provided by Aristotle
space-time is in fact necessary to derive the Lorentz transformations from
physical hypotheses.


title: Thermal Emission of Exoplanet XO-1b

abstract:
  We estimate flux ratios of the extrasolar planet XO-1b to its host star XO-1
at 3.6, 4.5, 5.8 and 8.0 microns with the IRAC on the Spitzer Space Telescope
to be 0.00086 +/- 0.00007, 0.00122 +/- 0.00009, 0.00261 +/- 0.00031 and 0.00210
+/- 0.00029, respectively. The fluxes are inconsistent with a canonical
cloudless model for the thermal emission from a planet and suggest an
atmosphere with a thermal inversion layer and a possible stratospheric
absorber. A newly emerging correlation between the presence of a thermal
inversion layer in the planetary atmosphere and stellar insolation of the
planet (Burrows et al. 2007b) is refined. The sub-stellar point flux from the
parent star at XO-1b of ~ 0.49 x 10^9 erg cm^-2 s^-1 sets a new lower limit for
the occurrence of a thermal inversion in a planetary atmosphere.


title:
Spectral densities of superconducting qubits with environmental
  resonances

abstract:
  In this paper we derive the environmental spectral density for flux, phase
and charge qubits when each of them is coupled to an environment with a
resonance. From the spectral density we obtain the characteristic spontaneous
emission (relaxation) lifetimes $T_1$ for each of these qubits, and show that
there is a substantial enhancement of $T_1$ beyond the resonant frequency of
the environment.


title: Synchronizability of chaotic logistic maps in delayed complex networks

abstract:
  We study a network of coupled logistic maps whose interactions occur with a
certain distribution of delay times. The local dynamics is chaotic in the
absence of coupling and thus the network is a paradigm of a complex system.
There are two regimes of synchronization, depending on the distribution of
delays: when the delays are sufficiently heterogeneous the network synchronizes
on a steady-state (that is unstable for the uncoupled maps); when the delays
are homogeneous, it synchronizes in a time-dependent state (that is either
periodic or chaotic). Using two global indicators we quantify the
synchronizability on the two regimes, focusing on the roles of the network
connectivity and the topology. The connectivity is measured in terms of the
average number of links per node, and we consider various topologies
(scale-free, small-world, star, and nearest-neighbor with and without a central
hub). With weak connectivity and weak coupling strength, the network displays
an irregular oscillatory dynamics that is largely independent of the topology
and of the delay distribution. With heterogeneous delays, we find a threshold
connectivity level below which the network does not synchronize, regardless of
the network size. This minimum average number of neighbors seems to be
independent of the delay distribution. We also analyze the effect of
self-feedback loops and find that they have an impact on the synchronizability
of small networks with large coupling strengths. The influence of feedback,
enhancing or degrading synchronization, depends on the topology and on the
distribution of delays.


title: Malicious Bayesian Congestion Games

abstract:
  In this paper, we introduce malicious Bayesian congestion games as an
extension to congestion games where players might act in a malicious way. In
such a game each player has two types. Either the player is a rational player
seeking to minimize her own delay, or - with a certain probability - the player
is malicious in which case her only goal is to disturb the other players as
much as possible.
  We show that such games do in general not possess a Bayesian Nash equilibrium
in pure strategies (i.e. a pure Bayesian Nash equilibrium). Moreover, given a
game, we show that it is NP-complete to decide whether it admits a pure
Bayesian Nash equilibrium. This result even holds when resource latency
functions are linear, each player is malicious with the same probability, and
all strategy sets consist of singleton sets. For a slightly more restricted
class of malicious Bayesian congestion games, we provide easy checkable
properties that are necessary and sufficient for the existence of a pure
Bayesian Nash equilibrium.
  In the second part of the paper we study the impact of the malicious types on
the overall performance of the system (i.e. the social cost). To measure this
impact, we use the Price of Malice. We provide (tight) bounds on the Price of
Malice for an interesting class of malicious Bayesian congestion games.
Moreover, we show that for certain congestion games the advent of malicious
types can also be beneficial to the system in the sense that the social cost of
the worst case equilibrium decreases. We provide a tight bound on the maximum
factor by which this happens.


title:
Transceiver Pair Designs for Multiple Access Channels under Fixed Sum
  Mutual Information using MMSE Decision Feedback Detection

abstract:
  In this paper, we consider the joint design of the transceivers for a
multiple access Multiple Input and Multiple Output (MIMO) system having
Inter-Symbol Interference (ISI) channels. The system we consider is equipped
with the Minimum Mean Square Error (MMSE) Decision-Feedback (DF) detector.
Traditionally, transmitter designs for this system have been based on
constraints of either the transmission power or the
signal-to-interference-and-noise ratio (SINR) for each user. Here, we explore a
novel perspective and examine a transceiver design which is based on a fixed
sum mutual information constraint and minimizes the arithmetic average of mean
square error of MMSE-decision feedback detection. For this optimization
problem, a closed-form solution is obtained and is achieved if and only if the
averaged sum mutual information is uniformly distributed over each active
subchannel. Meanwhile, the mutual information of the currently detected user is
uniformly distributed over each individual symbol within the block signal of
the user, assuming all the previous user signals have been perfectly detected.


title: Green Codes: Energy-Efficient Short-Range Communication

abstract:
  A green code attempts to minimize the total energy per-bit required to
communicate across a noisy channel. The classical information-theoretic
approach neglects the energy expended in processing the data at the encoder and
the decoder and only minimizes the energy required for transmissions. Since
there is no cost associated with using more degrees of freedom, the
traditionally optimal strategy is to communicate at rate zero.
  In this work, we use our recently proposed model for the power consumed by
iterative message passing. Using generalized sphere-packing bounds on the
decoding power, we find lower bounds on the total energy consumed in the
transmissions and the decoding, allowing for freedom in the choice of the rate.
We show that contrary to the classical intuition, the rate for green codes is
bounded away from zero for any given error probability. In fact, as the desired
bit-error probability goes to zero, the optimizing rate for our bounds
converges to 1.


title: The birational type of the moduli space of even spin curves

abstract:
  We determine the Kodaira dimension of the moduli space of even spin curves
for all genera, with one possible exception: The scheme S_g has negative
Kodaira dimension for g<8 and it is of general type for g>8. The Kodaira
dimension of S_8 is non-negative.


title: Minimal triangulations for an infinite family of lens spaces

abstract:
  The notion of a layered triangulation of a lens space was defined by Jaco and
Rubinstein in earlier work, and, unless the lens space is L(3,1), a layered
triangulation with the minimal number of tetrahedra was shown to be unique and
termed its "minimal layered triangulation." This paper proves that for each
integer n>1, the minimal layered triangulation of the lens space L(2n,1) is its
unique minimal triangulation. More generally, the minimal triangulations (and
hence the complexity) are determined for an infinite family of lens spaces
containing the lens spaces L(2n,1).


title:
Stellar and Circumstellar Properties of the Pre-Main Sequence Binary GV
  Tau from Infrared Spectroscopy

abstract:
  We report spatially resolved spectroscopy of both components of the low-mass
pre-main-sequence binary GV Tau. High resolution spectroscopy in the K- and
L-bands is used to characterize the stellar properties of the binary and to
explore the nature of the circumstellar environment. We find that the southern
component, GV Tau S, is a radial velocity variable, possibly as a result of an
unseen low-mass companion. The strong warm gaseous HCN absorption reported
previously toward GV Tau S (Gibb et al. 2007) was not present during the epoch
of our observations. Instead, we detect warm (~500 K) molecular absorption with
similar properties toward the northern infrared companion, GV Tau N. At the
epoch of our observations, the absorbing gas toward GV Tau N was approximately
at the radial velocity of the GV Tau molecular envelope, but it was redshifted
with respect to the star by ~13 km/s. One interpretation of our results is that
GV Tau N is also a binary and that most of the warm molecular absorption arises
in a circumbinary disk viewed close to edge-on.


title:
On Trapping Sets and Guaranteed Error Correction Capability of LDPC
  Codes and GLDPC Codes

abstract:
  The relation between the girth and the guaranteed error correction capability
of $\gamma$-left regular LDPC codes when decoded using the bit flipping (serial
and parallel) algorithms is investigated. A lower bound on the size of variable
node sets which expand by a factor of at least $3 \gamma/4$ is found based on
the Moore bound. An upper bound on the guaranteed error correction capability
is established by studying the sizes of smallest possible trapping sets. The
results are extended to generalized LDPC codes. It is shown that generalized
LDPC codes can correct a linear fraction of errors under the parallel bit
flipping algorithm when the underlying Tanner graph is a good expander. It is
also shown that the bound cannot be improved when $\gamma$ is even by studying
a class of trapping sets. A lower bound on the size of variable node sets which
have the required expansion is established.


title:
Phase transition in site-diluted Josephson junction arrays: A numerical
  study

abstract:
  We numerically investigate the intriguing effects produced by random
percolative disorder in two-dimensional Josephson-junction arrays. By dynamic
scaling analysis, we evaluate critical temperatures and critical exponents with
high accuracy. It is observed that, with the introduction of site-diluted
disorder, the Kosterlitz-Thouless phase transition is eliminated and evolves
into a continuous transition with power-law divergent correlation length.
Moreover, genuine depinning transition and creep motion are studied, evidence
for distinct creep motion types is provided. Our results not only are in good
agreement with the recent experimental findings, but also shed some light on
the relevant phase transitions.


title: Galactic Neutrino Communication

abstract:
  We examine the possibility to employ neutrinos to communicate within the
galaxy. We discuss various issues associated with transmission and reception,
and suggest that the resonant neutrino energy near 6.3 PeV may be most
appropriate. In one scheme we propose to make Z^o particles in an overtaking
e^+ - e^- collider such that the resulting decay neutrinos are near the W^-
resonance on electrons in the laboratory. Information is encoded via time
structure of the beam. In another scheme we propose to use a 30 PeV pion
accelerator to create neutrino or anti-neutrino beams. The latter encodes
information via the particle/anti-particle content of the beam, as well as
timing. Moreover, the latter beam requires far less power, and can be
accomplished with presently foreseeable technology. Such signals from an
advanced civilization, should they exist, will be eminently detectable in
neutrino detectors now under construction.


title: $gl(4|4)$ current algebra: free field realization and screening currents

abstract:
  The $gl(4|4)$ current algebra at general level $k$ is investigated. Its free
field representation and corresponding energy-momentum tensor are constructed.
Seven screening currents of the first kind are also presented.


title: DM-TPC: a new approach to directional detection of Dark Matter

abstract:
  Directional detection can provide unambiguous observation of Dark Matter
interactions even in presence of insidious backgrounds. The DM-TPC
collaboration is developing a detector with the goal of measuring the direction
and sense of nuclear recoils produced in Dark Matter interactions. The detector
consists of a Time Projection Chamber with optical readout filled with CF$_4$
gas at low pressure. A collision between a WIMP and a gas molecule results in a
nuclear recoil of 1-2 mm. The measurement of the energy loss along the recoil
allows us to determine the sense and the direction of the recoil.
  Results from a prototype detector operated in a low-energy neutron beam
clearly demonstrate the suitability of this approach to measure directionality.
A full-scale module with an active volume of about one cubic meter is now being
designed. This detector, which will be operated underground in 2009, will allow
us to set competitive limits on spin-dependent Dark Matter interactions using a
directional detector.


title: The Steady State Distribution of the Master Equation

abstract:
  The steady states of the master equation are investigated. We give two
expressions for the steady state distribution of the master equation a la the
Zubarev-McLennan steady state distribution, i.e., the exact expression and an
expression near equilibrium. The latter expression obtained is consistent with
recent attempt of constructing steady state theormodynamics.


title: Isometric Immersions and Compensated Compactness

abstract:
  A fundamental problem in differential geometry is to characterize intrinsic
metrics on a two-dimensional Riemannian manifold ${\mathcal M}^2$ which can be
realized as isometric immersions into $\R^3$. This problem can be formulated as
initial and/or boundary value problems for a system of nonlinear partial
differential equations of mixed elliptic-hyperbolic type whose mathematical
theory is largely incomplete. In this paper, we develop a general approach,
which combines a fluid dynamic formulation of balance laws for the
Gauss-Codazzi system with a compensated compactness framework, to deal with the
initial and/or boundary value problems for isometric immersions in $\R^3$. The
compensated compactness framework formed here is a natural formulation to
ensure the weak continuity of the Gauss-Codazzi system for approximate
solutions, which yields the isometric realization of two-dimensional surfaces
in $\R^3$. As a first application of this approach, we study the isometric
immersion problem for two-dimensional Riemannian manifolds with strictly
negative Gauss curvature. We prove that there exists a $C^{1,1}$ isometric
immersion of the two-dimensional manifold in $\R^3$ satisfying our prescribed
initial conditions. T


title: Stellar Parameters and Elemental Abundances of Late-G Giants

abstract:
  The properties of 322 intermediate-mass late-G giants (comprising 10
planet-host stars) selected as the targets of Okayama Planet Search Program,
many of which are red-clump giants, were comprehensively investigated by
establishing their various stellar parameters (atmospheric parameters including
turbulent velocity fields, metallicity, luminosity, mass, age, projected
rotational velocity, etc.), and their photospheric chemical abundances for 17
elements, in order to study their mutual dependence, connection with the
existence of planets, and possible evolution-related characteristics. The
metallicity distribution of planet-host giants was found to be almost the same
as that of non-planet-host giants, making marked contrast to the case of
planet-host dwarfs tending to be metal-rich. Generally, the metallicities of
these comparatively young (typical age of ~10^9 yr) giants tend to be somewhat
lower than those of dwarfs at the same age, and super-metal-rich ([Fe/H] > 0.2)
giants appear to be lacking. Apparent correlations were found between the
abundances of C, O, and Na, suggesting that the surface compositions of these
elements have undergone appreciable changes due to dredge-up of H-burning
products by evolution-induced deep envelope mixing which becomes more efficient
for higher-mass stars.


title: Probing Non-Standard Neutrino Physics at Neutrino Factory and T2KK

abstract:
  We discuss ways to explore non-standard interactions (NSI) which neutrinos
may possess by expressing them as effective four Fermi operators with
coefficient of the order of (M_{W} / M_{NP})^2 ~0.01 (0.0001) for energy scales
of new physics as M_{NP} ~1 (10) TeV. Neutrino Factory is a prime candidate for
such apparatus that can reach to the extreme precision. I describe a two
detector setting, one at baseline L~3000 km and the other at L~7000 km, which
is able to solve the notorious theta_{13}-NSI confusion, and possibly also the
two-phase confusion. The resultant sensitivities to off-diagonal NSI elements
\epsilon's are excellent, |\epsilon_{e tau}| \simeq a few \times10^{-3} and
|\epsilon_{e mu}| \simeq a few \times10^{-4}. Our results suggest a new picture
of neutrino factory as a hunting machine for NSI while keeping its potential of
precision measurement of lepton mixing parameters. Sensitivities to NSI by T2KK
and the related settings are also discussed.


title: Abundances of lithium, sodium, and potassium in Vega

abstract:
  Vega's photospheric abundances of Li, Na, and K were determined by using
considerably weak lines measured on the very high-S/N spectrum, while the
non-LTE correction and the gravity-darkening correction were adequately taken
into account. It was confirmed that these alkali elements are mildly
underabundant ([Li/H] ~ -0.6, [Na/H] ~ -0.3, and [K/H] ~ -0.2) compared to the
solar system values, as generally seen also in other metals. Since the tendency
of Li being more deficient than Na and K is qualitatively similar to what is
seen in typical interstellar cloud, the process of interstellar gas accretion
may be related with the abundance anomaly of Vega, as suspected in the case of
lambda Boo stars.


title:
Scalable, efficient ion-photon coupling with phase Fresnel lenses for
  large-scale quantum computing

abstract:
  Efficient ion-photon coupling is an important component for large-scale
ion-trap quantum computing. We propose that arrays of phase Fresnel lenses
(PFLs) are a favorable optical coupling technology to match with multi-zone ion
traps. Both are scalable technologies based on conventional micro-fabrication
techniques. The large numerical apertures (NAs) possible with PFLs can reduce
the readout time for ion qubits. PFLs also provide good coherent ion-photon
coupling by matching a large fraction of an ion's emission pattern to a single
optical propagation mode (TEM00). To this end we have optically characterized a
large numerical aperture phase Fresnel lens (NA=0.64) designed for use at 369.5
nm, the principal fluorescence detection transition for Yb+ ions. A
diffraction-limited spot w0=350+/-15 nm (1/e^2 waist) with mode quality M^2=
1.08+/-0.05 was measured with this PFL. From this we estimate the minimum
expected free space coherent ion-photon coupling to be 0.64%, which is twice
the best previous experimental measurement using a conventional multi-element
lens. We also evaluate two techniques for improving the entanglement fidelity
between the ion state and photon polarization with large numerical aperture
lenses.


title: Certified Exact Transcendental Real Number Computation in Coq

abstract:
  Reasoning about real number expressions in a proof assistant is challenging.
Several problems in theorem proving can be solved by using exact real number
computation. I have implemented a library for reasoning and computing with
complete metric spaces in the Coq proof assistant and used this library to
build a constructive real number implementation including elementary real
number functions and proofs of correctness. Using this library, I have created
a tactic that automatically proves strict inequalities over closed elementary
real number expressions by computation.


title:
Model-independent analysis for determining mass splittings of heavy
  baryons

abstract:
  We study the hyperfine mass differences of heavy hadrons in the heavy quark
effect theory (HQET). The effects of one-gluon exchange interaction are
considered for the heavy mesons and baryons. Base on the known experimental
data, we predict the masses of some heavy baryons in a model-independent way.


title:
Analysis of hydrocyclone performance based on information granulation
  theory

abstract:
  This paper describes application of information granulation theory, on the
analysis of hydrocyclone perforamance. In this manner, using a combining of
Self Organizing Map (SOM) and Neuro-Fuzzy Inference System (NFIS), crisp and
fuzzy granules are obtained(briefly called SONFIS). Balancing of crisp granules
and sub fuzzy granules, within non fuzzy information (initial granulation), is
rendered in an open-close iteration. Using two criteria, "simplicity of rules
"and "adaptive threoshold error level", stability of algorithm is guaranteed.
Validation of the proposed method, on the data set of the hydrocyclone is
rendered.


title: Energetics of X-ray Cavities and Radio Lobes in Galaxy Clusters

abstract:
  We describe the formation and evolution of X-ray cavities in the hot gas of
galaxy clusters. The cavities are formed only with relativistic cosmic rays
that eventually diffuse into the surrounding gas. We explore the evolution of
cavities formed with a wide range of cosmic ray diffusion rates. In previous
numerical simulations cavities are formed by injecting ultra-hot but
non-relativistic gas which increases the global thermal energy, offsetting
radiative losses in the gas and helping to solve the cooling flow problem.
Contrary to these results, we find that X-ray cavities formed solely by cosmic
rays have a global cooling effect. As the cluster gas is displaced by cosmic
rays, a global expansion of the cluster gas occurs with associated cooling that
exceeds the heating by shock waves as the cavity forms. Most cosmic rays in our
cavity evolutions do not move beyond the cooling radius even after 1 Gyr. The
gas density is depressed by cosmic rays, becomes buoyant, and undergoes a
significant outward mass transfer within the cooling radius, carrying cosmic
rays and relatively low entropy gas to distant regions in the cluster where it
remains for times exceeding the local cooling time in the hot gas. This
post-cavity mass outflow due to cosmic ray buoyancy may contribute toward
solving the cooling flow problem. We describe the energetics, size, stability
and buoyant rise of X-ray cavities in detail, showing how each depends on the
rate of cosmic ray diffusion.


title: Is the Z^+(4430) a radially excited state of D_s?

abstract:
  We present the interpretation that the recently discovered Z^+(4430) by the
Belle Collaboration can be a radial excitation of the cs-bar state. We give an
explicit cs-bar candidate for this state by calculating the mass value in our
semirelativistic quark potential model and also give a natural interpretation
on the reason why the decay mode Z-> J/\psi \pi^+ has not yet been seen while
Z-> \psi' \pi can be seen.


title:
The scale-free character of the cluster mass function and the
  universality of the stellar IMF

abstract:
  Our recent determination of a Salpeter slope for the IMF in the field of 30
Doradus (Selman and Melnick 2005) appears to be in conflict with simple
probabilistic counting arguments advanced in the past to support observational
claims of a steeper IMF in the LMC field. In this paper we re-examine these
arguments and show by explicit construction that, contrary to these claims, the
field IMF is expected to be exactly the same as the stellar IMF of the clusters
out of which the field was presumably formed. We show that the current data on
the mass distribution of clusters themselves is in excellent agreement with our
model, and is consistent with a single spectrum {\it by number of stars} of the
type $n^\beta$ with beta between -1.8 and -2.2 down to the smallest clusters
without any preferred mass scale for cluster formation. We also use the random
sampling model to estimate the statistics of the maximal mass star in clusters,
and confirm the discrepancy with observations found by Weidner and Kroupa
(2006). We argue that rather than signaling the violation of the random
sampling model these observations reflect the gravitationally unstable nature
of systems with one very large mass star. We stress the importance of the
random sampling model as a \emph{null hypothesis} whose violation would signal
the presence of interesting physics.


title: Studies on the second member of the second Painlev\'e hierarchy

abstract:
  In this paper, we study the second member of the second Painlev\'e hierarchy
$P_{II}^{(2)}$. We show that the birational transformations take this equation
to the polynomial Hamiltonian system in dimension four, and this Hamiltonian
system can be considered as a 1-parameter family of coupled Painlev\'e systems.
This Hamiltonian is new. We also show that this system admits extended affine
Weyl group symmetry of type $A_1^{(1)}$, and can be recovered by its holomorphy
conditions. We also study a fifth-order ordinary differential equation
satisfied by this Hamiltonian. After we transform this equation into a system
of the first-order ordinary differential equations of polynomial type in
dimension five by birational transformations, we give its symmetry and
holomorphy conditions.


title:
Generalized susceptibility of quasi-one dimensional system with periodic
  potential: model for the organic superconductor (TMTSF)$_2$ClO$_4$

abstract:
  The nesting vector and the magnetic susceptibility of the
quasi-one-dimensional system having imperfectly nested Fermi surface are
studied analytically and numerically. The magnetic susceptibility has the
plateau-like maximum in ``\textit{sweptback}'' region in the momentum space,
which is surrounded by $\mathbf{Q}=(2 k_F, \pi) + \mathbf{q}_i$ ($k_F$ is the
Fermi wave number, $i=1,3,4$, and $\mathbf{q}_1$, $\mathbf{q}_3$ and
$\mathbf{q}_{4}$ are given in this paper). The best nesting vector, at which
the susceptibility $\chi_0(\mathbf{Q})$ has the absolute maximum at T=0, is
obtained near but not at the inflection point, $\mathbf{Q}=(2 k_F,
\pi)+\mathbf{q}_4$. The effect of the periodic potential $V$ on the
susceptibility is studied, which is important for the successive transitions of
the field-induced spin density wave in (TMTSF)$_2$ClO$_4$. We obtain that the
sweptback region (surrounded by $\mathbf{q}_2$, $\mathbf{q}_3$ and
$\mathbf{q}_4$ when $V>0$) becomes small as $V$ increases and it shrinks to
$\mathbf{q}_3$ for $V \geq 4 t_b'$, where $t_b'$ gives the degree of imperfect
nesting of the Fermi surface, i.e. the second harmonics of the warping in the
Fermi surface. The occurrence of the sign reversal of the Hall coefficient in
the field-induced spin density wave states is discussed to be possible only
when $V<2 t_b'-2 t_4$, where $t_4$ is the amplitude of the fourth harmonics of
the warping in the Fermi surface. This gives the novel limitation for the
magnitude of $V$.


title:
Test and Developments of Crystals for a High-Resolution Electromagnetic
  Calorimeter for PANDA

abstract:
  The energy resolution of PWO crystals and their dependence on the incoming
energy has been investigated. The crystals used were first prototype crystals
of a new generation, characterized by a higher light yield. Two crystal types
with different shape and light yield, manufactured by suppliers in China and
Russia, were used. An experiments were performed on two cooled arrays of 3x3
crystals. Photon beams of eight different energies, ranging from 64 MeV to 715
MeV, were directed into the center crystals. Photo Multiplier Tubes were used
to read out the response of the scintillators. The energy resolution was
calculated using three different methods - FWHM, a two gaussian fit and a right
side fit. The two Gaussian method delivered the lowest sigma value and also the
lowest energy resolution. The obtained energy resolution for the Russian
crystals was 1.61%/sqrt(E)+0.73% and similarly 1.58%/sqrt(E)+4.25% for the
Chinese crystals.


title: An abstract characterization of unital operator spaces

abstract:
  In this article, we give an abstract characterization of the ``identity'' of
an operator space $V$ by looking at a quantity $n_{cb}(V,u)$ which is defined
in analogue to a well-known quantity in Banach space theory. More precisely, we
show that there exists a complete isometry from $V$ to some $\mathcal{L}(H)$
sending $u$ to ${\rm id}_H$ if and only if $n_{cb}(V,u) =1$. We will use it to
give an abstract characterization of operator systems. Moreover, we will show
that if $V$ is a unital operator space and $W$ is a proper complete $M$-ideal,
then $V/W$ is also a unital operator space. As a consequece, the quotient of an
operator system by a proper complete $M$-ideal is again an operator system. In
the appendix, we will also give an abstract characterisation of ``non-unital
operator systems'' using an idea arose from the definition of $n_{cb}(V,u)$.


title: Frictional Duality Observed during Nanoparticle Sliding

abstract:
  One of the most fundamental questions in tribology concerns the area
dependence of friction at the nanoscale. Here, experiments are presented where
the frictional resistance of nanoparticles is measured by pushing them with the
tip of an atomic force microscope. We find two coexisting frictional states:
While some particles show finite friction increasing linearly with the
interface areas of up to 310,000nm^2, other particles assume a state of
frictionless sliding. The results further suggest a link between the degree of
surface contamination and the occurrence of this duality.


title: Asymmetric nuclear matter : a variational approach

abstract:
  We discuss here a self-consistent method to calculate the properties of the
cold asymmetric nuclear matter. In this model, the nuclear matter is dressed
with s-wave pion pairs and the nucleon-nucleon (N-N) interaction is mediated by
these pion pairs, $\omega$ and $\rho$ mesons. The parameters of these
interactions are calculated self-consistently to obtain the saturation
properties like equilibrium binding energy, pressure, compressibility and
symmetry energy. The computed equation of state is then used in the Tolman-
Oppenheimer-Volkoff (TOV) equation to study the mass and radius of a neutron
star in the pure neutron matter limit.


title: Ion-trap quantum information processing: experimental status

abstract:
  Atomic ions trapped in ultra-high vacuum form an especially well-understood
and useful physical system for quantum information processing. They provide
excellent shielding of quantum information from environmental noise, while
strong, well-controlled laser interactions readily provide quantum logic gates.
A number of basic quantum information protocols have been demonstrated with
trapped ions. Much current work aims at the construction of large-scale
ion-trap quantum computers using complex microfabricated trap arrays. Several
groups are also actively pursuing quantum interfacing of trapped ions with
photons.


title:
The Lorentz and Levi-Civita Conservation Laws Prohibit the Existence of
  Black Holes

abstract:
  To propose that black holes do not exist would be the fundamental way to
resolve the contradiction between event horizons and quantum mechanics. In this
paper we shall use the Lorentz and Levi-Civita conservation laws to explain how
an event horizon might not exist, and the reasons for its nonexistence are
presented by using the theory of classical gravity.


title:
Updated analysis of the dynamical relation between asteroid 2003 EH1 and
  comets C/1490 Y1 and C/1385 U1

abstract:
  The asteroid 2003 EH1, proposed as the parent body of the Quadrantid meteor
shower, is thought to be the remnant of a past cometary object, tentatively
identified with the historical comets C/1490 Y1 and C/1385 U1. In the present
work we use recovery astrometry to extend the observed arc of 2003 EH1 from 10
months to about 5 years, enough to exclude the proposed direct relationship of
the asteroid with both of the comets.


title:
Non-Equilibrium Ionization State and Two-Temperature Structure in the
  Linked Region of Abell 399/401

abstract:
  We investigate a non-equilibrium ionization state and two-temperature
structure of the intracluster medium in the linked region of Abell 399/401,
using a series of N-body + SPH simulations, and find that there exist
significant shock layers at the edge of the linked region, and that the
ionization state of iron departs from the ionization equilibrium state at the
shock layers and around the center of the linked region. As for the
two-temperature structure, an obvious difference of temperature between
electrons and ions is found in the edge of the linked regions. K alpha line
emissions of Fe xxiv and Fe xxv are not severely affected by the deviation from
the ionization equilibrium state around the center of the linked region,
suggesting that the detection of relatively high metallicity in this area
cannot be ascribed to the non-equilibrium ionization state of the intracluster
medium. On the other hand, the K alpha emissions are significantly deviated
from the equilibrium values at the shock layers, and the intensity ratio of K
alpha lines between Fe xxiv-xxv and Fe xxvi is found to be significantly
altered from that in the ionization equilibrium state.


title: Splitting Sensitivity of the Ground and 7.6 eV Isomeric States of 229Th

abstract:
  The lowest-known excited state in nuclei is the 7.6 eV isomer of 229Th. This
energy is within the range of laser-based investigations that could allow
accurate measurements of possible temporal variation of this energy splitting.
This in turn could probe temporal variation of the fine-structure constant or
other parameters in the nuclear Hamiltonian. We investigate the sensitivity of
this transition energy to these quantities. We find that the two states are
predicted to have identical deformations and thus the same Coulomb energies
within the accuracy of the model (viz., within roughly 30 keV). We therefore
find no enhanced sensitivity to variation of the fine-structure constant. In
the case of the strong interaction the energy splitting is found to have a
complicated dependence on several parameters of the interaction, which makes an
accurate prediction of sensitivity to temporal changes of fundamental constants
problematical. Neither the strong- nor Coulomb-interaction contributions to the
energy splitting of this doublet can be constrained within an accuracy better
than a few tens of keV, so that only upper limits can be set on the possible
sensitivity to temporal variations of the fundamental constants.


title:
Semiclassical quantization of electrons in magnetic fields: the
  generalized Peierls substitution

abstract:
  A generalized Peierls substitution which takes into account a Berry phase
term must be considered for the semiclassical treatment of electrons in a
magnetic field. This substitution turns out to be an essential element for the
correct determination of the semiclassical equations of motion as well as for
the semiclassical Bohr-Sommerfeld quantization condition for energy levels. A
general expression for the cross-sectional area is derived and used as an
illustration for the calculation of the energy levels of Bloch and Dirac
electrons.


title: A pattern mixture model for a paired $2\times2$ crossover design

abstract:
  When conducting a paired $2\times2$ crossover design, each subject is paired
with another subject with similar characteristics. The pair is then randomized
to the same sequence of two treatments. That is, the two subjects receive the
first experimental treatment, and then they cross over and receive the other
experimental treatment(s). The paired $2\times2$ crossover design that was used
in the Beta Adrenergic Response by GEnotype (BARGE) Study conducted by the
National Heart, Lung and Blood Institute's Asthma Clinical Research Network
(ACRN) has been described elsewhere. When the data arising from such a design
are balanced and complete -- or if at least any missingness that occurs is at
random -- general linear mixed-effects model methods can be used to analyze the
data. In this paper, we present a method based on a pattern-mixture model for
analyzing the data arising from a paired $2\times2$ crossover design when some
of the data are missing in a non-ignorable fashion. Because of its inherent
scientific interest, we focus our particular attention on the estimation of the
treatment-by-type of subject interaction term. Finally, we illustrate the
pattern-mixture model methods described in this paper on the data arising from
the BARGE study.


title:
A compressible two-fluid model for the finite volume simulation of
  violent aerated flows. Analytical properties and numerical results

abstract:
  In the study of ocean wave impact on structures, one often uses Froude
scaling since the dominant force is gravity. However the presence of trapped or
entrained air in the water can significantly modify wave impacts. When air is
entrained in water in the form of small bubbles, the acoustic properties in the
water change dramatically and for example the speed of sound in the mixture is
much smaller than in pure water, and even smaller than in pure air. While some
work has been done to study small-amplitude disturbances in such mixtures,
little work has been done on large disturbances in air-water mixtures. We
propose a basic two-fluid model in which both fluids share the same velocities.
It is shown that this model can successfully mimic water wave impacts on
coastal structures. Even though this is a model without interface, waves can
occur. Their dispersion relation is discussed and the formal limit of pure
phases (interfacial waves) is considered. The governing equations are
discretized by a second-order finite volume method. Numerical results are
presented. It is shown that this basic model can be used to study violent
aerated flows, especially by providing fast qualitative estimates.

categories: physics.class-ph math.AP math.NA physics.comp-ph


title: Free Energy of Twisted Semiflexible Polymers

abstract:
  We investigate the role of fluctuations in single molecule measurements of
torque-link ($t-lk$) curves. For semiflexible polymers of finite persistence
length (i.e. polymers with contour length $L$ comparable to the persistence
length $L_P$), the torque versus link curve in the constant torque (isotorque)
ensemble is distinct from the one in the constant link (isolink) ensemble.
Thus, one encounters the conceptually interesting issue of a ``free energy of
transition'' in switching ensembles while making torque-link measurements. We
predict the dependence on the semiflexibility parameter $\beta = L/L_P$ of this
extra contribution to the free energy which shows up as an area in the
torque-link plane. This can be tested against future torque-link experiments
with single biopolymers. We bring out the inequivalence of torque-link curves
for a stiff polymer and present explicit analytical expressions for the {\it
distinct} torque-link relations in the two ensembles and the free energy
difference in switching ensembles in this context. The predictions of our work
can be tested against single molecule experiments on torsionally constrained
biopolymers.


title: New Prototype Multi-gap Resistive Plate Chambers with Long Strips

abstract:
  A new kind of Multi-gap Resistive Plate Chamber (MRPC) has been built for the
large-area Muon Telescope Detector (MTD) for the STAR experiment at RHIC. These
long read-out strip MRPCs (LMRPCs) have an active area of 87.0 x 17.0 cm2 and
ten 250 um-thick gas gaps arranged as a double stack. Each read-out strip is
2.5 cm wide and 90 cm long. The signals are read-out at both ends of each
strip. Cosmic ray tests indicate a time resolution of ~70 ps and a detection
efficiency of greater than 95%. Beam tests performed at T963 at Fermilab
indicate a time resolution of 60-70 ps and a spatial resolution of ~1 cm along
the strip direction.


title:
Projected likelihood contrasts for testing homogeneity in finite mixture
  models with nuisance parameters

abstract:
  This paper develops a test for homogeneity in finite mixture models where the
mixing proportions are known a priori (taken to be 0.5) and a common nuisance
parameter is present. Statistical tests based on the notion of Projected
Likelihood Contrasts (PLC) are considered. The PLC is a slight modification of
the usual likelihood ratio statistic or the Wilk's $\Lambda$ and is similar in
spirit to the Rao's score test. Theoretical investigations have been carried
out to understand the large sample statistical properties of these tests.
Simulation studies have been carried out to understand the behavior of the null
distribution of the PLC statistic in the case of Gaussian mixtures with unknown
means (common variance as nuisance parameter) and unknown variances (common
mean as nuisance parameter). The results are in conformity with the theoretical
results obtained. Power functions of these tests have been evaluated based on
simulations from Gaussian mixtures.


title: Hook lengths and 3-cores

abstract:
  Recently, the first author generalized a formula of Nekrasov and Okounkov
which gives a combinatorial formula, in terms of hook lengths of partitions,
for the coefficients of certain power series. In the course of this
investigation, he conjectured that $A000731(n)=0$ if and only if
$A033687(n)=0$. The numbers $A000731(n)$ are given in terms of hook lengths of
partitions, while $A033687(n)$ equals the number of 3-core partitions of $n$.
Here we prove this conjecture.


title:
Nuclear Force from Monte Carlo Simulations of Lattice Quantum
  Chromodynamics

abstract:
  The nuclear force acting between protons and neutrons is studied in the Monte
Carlo simulations of the fundamental theory of the strong interaction, the
quantum chromodynamics defined on the hypercubic space-time lattice. After a
brief summary of the empirical nucleon-nucleon (NN) potentials which can fit
the NN scattering experiments in high precision, we outline the basic
formulation to derive the potential between the extended objects such as the
nucleons composed of quarks. The equal-time Bethe-Salpeter amplitude is a key
ingredient for defining the NN potential on the lattice. We show the results of
the numerical simulations on a $32^4$ lattice with the lattice spacing $a
\simeq 0.137 $fm (lattice volume (4.4 fm)$^4$) in the quenched approximation.
The calculation was carried out using the massively parallel computer Blue
Gene/L at KEK. We found that the calculated NN potential at low energy has
basic features expected from the empirical NN potentials; attraction at long
and medium distances and the repulsive core at short distance. Various future
directions along this line of research are also summarized.


title:
The influence of intergranular interaction on the magnetization of the
  ensemble of oriented Stoner-Wohlfarth nanoparticles

abstract:
  We consider the influence of interparticle interaction on the magnetization
reversal in the oriented Stoner-Wohlfarth nanoparticles ensemble. To do so, we
solve a kinetic equation for the relaxation of the overall ensemble
magnetization to its equilibrium value in some effective mean field. Latter
field consists of external magnetic field and interaction mean field
proportional to the instantaneous value of above magnetization. We show that
the interparticle interaction influences the temperature dependence of a
coercive field. This influence manifests itself in the noticeable coercivity at
$T>T_{b}$ ($T_{b}$ is so-called blocking temperature). The above interaction
can also lead to a formation of the "superferromagnetic" state with correlated
directions of particle magnetic moments at $T>T_{b}$. This state possesses
coercivity if the overall magnetization has a component directed along the easy
axis of each particle. We have shown that the coercive field in the
"superferromagnetic" state does not depend on measuring time. This time
influences both $T_{b}$ and the temperature dependence of coercive field at
$T<T_{b}$. We corroborate our theoretical results by measurements on
nanogranular films (CoFeB)$_{x}$-(SiO$_{2}$)$_{1-x}$ with concentration of
ferromagnetic particles close, but below percolation threshold.


title: Discovering hook length formulas by expansion technique

abstract:
  We introduce the hook length expansion technique and explain how to discover
old and new hook length formulas for partitions and plane trees. The new hook
length formulas for trees obtained by our method can be proved rather easily,
whereas those for partitions are much more difficult and some of them still
remain open conjectures. We also develop a Maple package HookExp for computing
the hook length expansion. The paper can be seen as a collection of hook length
formulas for partitons and plane trees. All examples are illustrated by HookExp
and, for many easy cases, expained by well-known combinatorial arguments.


title: Schr\"oder Paths and Pattern Avoiding Partitions

abstract:
  In this paper, we show that both 12312-avoiding partitions and 12321-avoiding
partitions of the set $[n+1]$ are in one-to-one correspondence with Schr\"oder
paths of semilength $n$ without peaks at even level. As a consequence, the
refined enumeration of 12312-avoiding (resp. 12321-avoiding) partitions
according to the number of blocks can be reduced to the enumeration of certain
Schr\"oder paths according to the number of peaks. Furthermore, we get the
enumeration of irreducible 12312-avoiding (resp. 12321-avoiding) partitions,
which are closely related to skew Dyck paths.


title:
Turbulence and Magnetic Fields in the Large Scale Structure of the
  Universe

abstract:
  The nature and origin of turbulence and magnetic fields in the intergalactic
space are important problems that are yet to be understood. We propose a
scenario in which turbulent flow motions are induced via the cascade of the
vorticity generated at cosmological shocks during the formation of the large
scale structure. The turbulence in turn amplifies weak seed magnetic fields of
any origin. Supercomputer simulations show that the turbulence is subsonic
inside clusters/groups of galaxies, whereas it is transonic or mildly
supersonic in filaments. Based on a turbulence dynamo model, we then estimate
that the average magnetic field strength would be a few microgauss inside
clusters/groups, approximately 0.1 microgauss around clusters/groups, and
approximately 10 nanogauss in filaments. Our model presents a physical
mechanism that transfers the gravitation energy to the turbulence and magnetic
field energies in the large scale structure of the universe.


title: Heavy flavours

abstract:
  The paper introduces the selection of new results on heavy flavours presented
at the QCD and High Energy Interactions section of the XLIIIth ``Rencontres de
Moriond'' conference.


title: The Liouville phenomenon in the deformation problem of coisotropics

abstract:
  The work of Oh and Park ([OP]) on the deformation problem of coisotropic
submanifolds opened the possibility of studying a large and interesting class
of foliations with some explicit geometric tools. These tools assemble into the
structure of an L-infinity algebra on the shifted foliation complex
(\Omega^*[1](\fol), d_\fol), which allows a concise description of deformations
in terms of a Maurer-Cartan equation. Infinitesimal deformations are given by
d_\fol-closed forms, and the relation between infinitesimal deformations and
full deformations can be studied in terms of obstruction classes lying in the
foliation cohomology H^*_\fol. Closely related to the foliation cohomology is
Haefliger's group \Omega^*_c(T/H), an under-appreciated model for the leaf
space of a foliation. We make integral use of this group in showing solvability
and unsolvability of the obstruction equations. We also show the L-infinity
apparatus to be capable of detecting the Liouville/diophantine distinction of
KAM theory, and argue for the greater significance of Haefliger's
integration-over-leaves map in passing this fine structure to a geometric model
for the leaf space.


title:
QCD corrections to polarization of J/\psi and \Upsilon at Fermilab
  Tevatron and CERN LHC

abstract:
  In this work, we present more detail of the calculation on the NLO QCD
corrections to polarization of direct J/psi production via color singlet at
Tevatron and LHC, as well as the results for Upsilon for the first time. Our
results show that the J/psi polarization status drastically changes from
transverse polarization dominant at LO into longitudinal polarization dominant
in the whole range of the transverse momentum $p_t$ of J/psi when the NLO
corrections are counted. For Upsilon production, the p_t distribution of the
polarization status behaves almost the same as that for J/psi except that the
NLO result is transverse polarization at small p_t range. Although the
theoretical evaluation predicts a larger longitudinal polarization than the
measured value at Tevatron, it may provide a solution towards the previous
large discrepancy for J/psi and Upsilon polarization between theoretical
predication and experimental measurement, and suggests that the next important
step is to calculate the NLO corrections to hadronproduction of color octet
state J/psi^(8) and Upsilon^(8). Our calculations are performed in two ways,
namely we do and do not analytically sum over the polarizations, and then check
them with each other.


title: Bootstrapping the Grenander estimator

abstract:
  The goal of this paper is to study the bootstrap for the Grenander estimator.
The first result is a proof of the inconsistency of the nonparametric bootstrap
for the Grenander estimator at a given point. The second result is the
development and verification of a bootstrap for the $L_1$ confidence band for
the Grenander estimator. As part of this work, kernel estimators are studied as
alternatives to the Grenander estimator. We show that when the second
derivative of the true density is assumed to be uniformly bounded, there exist
kernel estimators with faster convergence rates than the Grenander estimator.
We study the implications of this in developing $L_1$ and uniform confidence
bands and discuss some open questions.


title: Characterization of Geometric Structures of Biaxial Nematic Phases

abstract:
  The ordering matrix, which was originally introduced by de Gennes, is a
well-known mathematical device for describing orientational order of biaxial
nematic liquid crystal. In this paper we propose a new interpretation of the
ordering matrix. We slightly modify the definition of the ordering matrix and
call it the geometric order parameter. The geometric order parameter is a
linear transformation which transforms a tensorial quantity of an individual
molecule to a tensorial quantity observed at a macroscopic scale. The degree of
order is defined as the singular value of the geometric order parameter. We
introduce the anisotropy diagram, which is useful for classification and
comparison of various tensorial quantities. As indices for evaluating
anisotropies of tensorial quantities, we define the degree of anisotropy and
the degree of biaxiality. We prove that a simple diagrammatic relation holds
between a microscopic tensor and a macroscopic tensor. We provide a
prescription to formulate the Landau-de Gennes free energy of a system whose
constituent molecules have an arbitrary shape. We apply our prescription to a
system which consists of D_{2h}-symmetric molecules.


title:
Stochastic local operations and classical communication properties of
  the n-qubit symmetric Dicke states

abstract:
  Recently, several schemes for the experimental creation of Dicke states were
described. In this paper, we show that all the $n$-qubit symmetric Dicke states
with $l$ ($2\leq l\leq (n-2)$) excitations are inequivalent to the $% |GHZ>$
state or the $|W>$ state under SLOCC, that the even $n$% -qubit symmetric Dicke
state with $n/2$ excitations is inequivalent to any even $n$-qubit symmetric
Dicke state with $l\neq n/2$ excitations under SLOCC, and that all the
$n$-qubit symmetric Dicke states with $l$ ($2\leq l\leq (n-2)$) excitations
satisfy Coffman, Kundu and Wootters' generalized monogamy inequality
$C_{12}^{2}+...+C_{1n}^{2}<C_{1(2...n)}^{2}<1$.


title: Ratio tests for change point detection

abstract:
  We propose new tests to detect a change in the mean of a time series. Like
many existing tests, the new ones are based on the CUSUM process. Existing
CUSUM tests require an estimator of a scale parameter to make them
asymptotically distribution free under the no change null hypothesis. Even if
the observations are independent, the estimation of the scale parameter is not
simple since the estimator for the scale parameter should be at least
consistent under the null as well as under the alternative. The situation is
much more complicated in case of dependent data, where the empirical spectral
density at 0 is used to scale the CUSUM process. To circumvent these
difficulties, new tests are proposed which are ratios of CUSUM functionals. We
demonstrate the applicability of our method to detect a change in the mean when
the errors are AR(1) and GARCH(1,1) sequences.


title: New Physics Search at LHCB

abstract:
  Although direct detection of new particles will be the main focus of the LHC,
indirect New Physics searches are expected to provide useful complementary
information. In particular, precision measurements of rare processes occurring
in flavour physics are of utmost importance in constraining the structure of
the New physics low energy effective Lagrangian. In this paper, few key LHCb
studies, including $B_s-\bar{B}_s$ mixing and rare decays through the quark
level $b\to s$ loop transition, are presented to illustrate New Physics effects
at low energy.


title:
Frustration of tilts and A-site driven ferroelectricity in
  KNbO_3-LiNbO_3 alloys

abstract:
  Density functional calculations for K_{0.5}Li_{0.5}NbO_3 show strong A-site
driven ferroelectricity, even though the average tolerance factor is
significantly smaller than unity and there is no stereochemically active A-site
ion. This is due to the frustration of tilt instabilities by A-site disorder.
There are very large off-centerings of the Li ions, which contribute strongly
to the anisotropy between the tetragonal and rhombohedral ferroelectric states,
yielding a tetragonal ground state even without strain coupling.


title:
Neutrino Cross Section Measurements for Long-Baseline Accelerator-based
  Neutrino Oscillation Experiments

abstract:
  Neutrino oscillations are clear evidence for physics beyond the standard
model. The goal of next-generation neutrino oscillation experiments is to find
a non-zero $\theta_{13}$, the last mixing matrix element for which we only know
an upper limit. For this, next-generation long-baseline neutrino oscillation
experiments require an order of magnitude better sensitivities. In particular,
accelerator-based experiments such as T2K and NOvA experiments need (1) good
neutrino energy reconstruction for the precise measurement of $\Delta m^2_{32}$
and $sin^22\theta_{23}$, and (2) good background prediction to measure $\nu_e$
appearance signals. Current and near future high statistics neutrino
experiments, such as K2K, MiniBooNE, SciBooNE, MINOS, and MINERvA help both (1)
and (2) by precise signal and background channel measurements.


title:
The structural role of weak and strong links in a financial market
  network

abstract:
  We investigate the properties of correlation based networks originating from
economic complex systems, such as the network of stocks traded at the New York
Stock Exchange (NYSE). The weaker links (low correlation) of the system are
found to contribute to the overall connectivity of the network significantly
more than the strong links (high correlation). We find that nodes connected
through strong links form well defined communities. These communities are
clustered together in more complex ways compared to the widely used
classification according to the economic activity. We find that some companies,
such as General Electric (GE), Coca Cola (KO), and others, can be involved in
different communities. The communities are found to be quite stable over time.
Similar results were obtained by investigating markets completely different in
size and properties, such as the Athens Stock Exchange (ASE). The present
method may be also useful for other networks generated through correlations.


title: Short-range correlations and shell structure of medium-mass nuclei

abstract:
  The single-particle spectrum of the two nuclei 133Sb and 101Sn is studied
within the framework of the time-dependent degenerate linked-diagram
perturbation theory starting from a class of onshell-equivalent realistic
nucleon-nucleon potentials. These potentials are derived from the CD-Bonn
interaction by using the so-called V-low-k approach with various cutoff
momenta. The results obtained evidence the crucial role of short-range
correlations in producing the correct 2s1d0g0h shell structure.


title:
A comparison of the Benjamini-Hochberg procedure with some Bayesian
  rules for multiple testing

abstract:
  In the spirit of modeling inference for microarrays as multiple testing for
sparse mixtures, we present a similar approach to a simplified version of
quantitative trait loci (QTL) mapping. Unlike in case of microarrays, where the
number of tests usually reaches tens of thousands, the number of tests
performed in scans for QTL usually does not exceed several hundreds. However,
in typical cases, the sparsity $p$ of significant alternatives for QTL mapping
is in the same range as for microarrays. For methodological interest, as well
as some related applications, we also consider non-sparse mixtures. Using
simulations as well as theoretical observations we study false discovery rate
(FDR), power and misclassification probability for the Benjamini-Hochberg (BH)
procedure and its modifications, as well as for various parametric and
nonparametric Bayes and Parametric Empirical Bayes procedures. Our results
confirm the observation of Genovese and Wasserman (2002) that for small p the
misclassification error of BH is close to optimal in the sense of attaining the
Bayes oracle. This property is shared by some of the considered Bayes testing
rules, which in general perform better than BH for large or moderate $p$'s.


title:
Curvature-spin coupling from the semi-classical limit of the Dirac
  equation

abstract:
  The notion of a classical particle is inferred from Dirac quantum fields on a
curved space-time, by an eikonal approximation and a localization hypothesis
for amplitudes. This procedure allows to define a semi-classical version of the
spin-tensor from internal quantum degrees of freedom, which has a
Papapetrou-like coupling with the curvature.


title:
The character table of a split extension of the Heisenberg group
  $H_1(q)$ by $Sp(2,q)$, $q$ odd

abstract:
  In this paper we determine the full character table of a certain split
extension $H_1(q)\rtimes Sp(2,q)$ of the Heisenberg group $H_1$ by the
odd-characteristic symplectic group $Sp(2,q)$.


title: Majorana Neutrino Superfluidity and Stability of Neutrino Dark Energy

abstract:
  We demonstrate that Majorana neutrinos can form Cooper pairs due to
long-range attractive forces and show BCS superfluidity in a class of mass
varying neutrino dark energy models. We describe the condensates for Majorana
neutrinos and estimate the value of the gap, critical temperature and Pippard
coherence length for a simple neutrino dark energy model. In the strong
coupling regime bosonic degree of freedom can become important and
Bose-Einstein condensate may govern the dynamics for the mass varying neutrino
models. Formation of the condensates can significantly alter the instability
scenario in the mass varying neutrino models.


title:
Universal frequency-dependent ac conductivity of conducting polymer
  networks

abstract:
  A model based on the aspect of the distribution of the length of conduction
paths accessible for electric charge flow reproduces the universal power-law
dispersive ac conductivity observed in polymer networks and, generally, in
disordered matter. Power exponents larger than unity observed in some cases are
physically acceptable within this model. A saturation high frequency region is
also predicted, in agreement with experimental results. There does not exist a
universal fractional power law (and is useless searching for a unique common
critical exponent), but a qualitative universal behavior of the ac conductivity
in disordered media.


title:
Azimuthal dependence of pion source radii in Pb+Au collisions at 158 A
  GeV

abstract:
  We present results of a two-pion correlation analysis performed with the
Au+Pb collision data collected by the upgraded CERES experiment in the fall of
2000. The analysis was done in bins of the reaction centrality and the pion
azimuthal emission angle with respect to the reaction plane. The pion source,
deduced from the data, is slightly elongated in the direction perpendicular to
the reaction plane, similarly as was observed at the AGS and at RHIC.


title: On estimating the change point in generalized linear models

abstract:
  Statistical models incorporating change points are common in practice,
especially in the area of biomedicine. This approach is appealing in that a
specific parameter is introduced to account for the abrupt change in the
response variable relating to a particular independent variable of interest.
The statistical challenge one encounters is that the likelihood function is not
differentiable with respect to this change point parameter. Consequently, the
conventional asymptotic properties for the maximum likelihood estimators fail
to hold in this situation. In this paper, we propose an estimating procedure
for estimating the change point along with other regression coefficients under
the generalized linear model framework. We show that the proposed estimators
enjoy the conventional asymptotic properties including consistency and
normality. Simulation work we conducted suggests that it performs well for the
situations considered. We applied the proposed method to a case-control study
aimed to examine the relationship between the risk of myocardial infarction and
alcohol intake.


title:
Migration volume for polaron dielectric relaxation in disordered
  materials

abstract:
  A theoretical study of the influence of pressure on the dielectric relaxation
related with polaron tunneling and phonon assisted hopping in disordered solids
is developed. The sign and absolute value of the migration volume, which is
obtained by employing the present formulation, evidence about the nature of the
relaxation. As a paradigm, positive and negative values of migration volume are
evaluated by analyzing recently published dielectric loss measurements under
pressure in semiconducting polypyrrole. A straightforward relation between the
value of the migration volume and the nature of short-range polaron flow and
the size of polaron distortion is revealed.


title:
Submm/FIR astronomy in Antarctica: Potential for a large telescope
  facility

abstract:
  Preliminary site testing datasets suggest that Dome C in Antarctica is one of
the best sites on Earth for astronomical observations in the 200 to 500 micron
regime, i.e. for far-infrared (FIR) and submillimetre (submm) astronomy. We
present an overview of potential science cases that could be addressed with a
large telescope facility at Dome C. This paper also includes a presentation of
the current knowledge about the site characterics in terms of atmospheric
transmission, stability, sky noise and polar constraints on telescopes. Current
and future site testing campaigns are finally described.


title: Transformation of polarons to bipolarons in disordered matter

abstract:
  The polaron to bipolaron transition in disordered media under the influence
of a broadband ac electric field is suggested: ac conductivity vs. frequency
measurements in disordered media with inhomogeneous disorder induce
spatio-temporal fluctuations of the density of polarons yielding polaron to
bipolaron transformation. The external field results in the transition,
alternatively to an increasing doping level. The assertion is confirmed by
performing successive complex impedance measurements in disordered media. A
systematic increase of the real part of the ac conductivity in the frequency
domain, followed by mutual reduction of the magnetic inductivity of conducting
polypyrrole, are explained.


title:
Geometric objects associated with the fundamental connections in Finsler
  geometry

abstract:
  The aim of the present paper is to provide an \emph{intrinsic} investigation
of the properties of the most important geometric objects associated with the
fundamental linear connections in Finsler geometry. We investigate
intrinsically the most general relations concerning the torsion tensor fields
and the curvature tensor fields associated with a given regular connection on
the pullback bundle of a Finsler manifold. These relations, in turn, play a key
role in obtaining other interesting results concerning the properties of the
most important geometric objects associated with the fundamental canonical
linear connections on the pullback bundle of a Finsler manifold, namely, the
Cartan connection, the Berwald connection, the Chern (Rund) connection and the
Hashiguchi connection.
  For the sake of completeness and for comparison reasons, we provide an
appendix presenting a global survey of canonical linear connections in Finsler
geometry and the fundamental geometric objects associated with them.


title: Using statistical smoothing to date medieval manuscripts

abstract:
  We discuss the use of multivariate kernel smoothing methods to date
manuscripts dating from the 11th to the 15th centuries, in the English county
of Essex. The dataset consists of some 3300 dated and 5000 undated manuscripts,
and the former are used as a training sample for imputing dates for the latter.
It is assumed that two manuscripts that are ``close'', in a sense that may be
defined by a vector of measures of distance for documents, will have close
dates. Using this approach, statistical ideas are used to assess
``similarity'', by smoothing among distance measures, and thus to estimate
dates for the 5000 undated manuscripts by reference to the dated ones.


title:
Search for Higgs bosons decaying to tau pairs in ppbar collisions with
  the D0 detector

abstract:
  We present a search for the production of neutral Higgs bosons phi decaying
into tau+tau- final states in ppbar collisions at a center-of-mass energy of
1.96 TeV. The data, corresponding to an integrated luminosity of approximately
1 fb-1, were collected by the D0 experiment at the Fermilab Tevatron Collider.
Limits on the production cross section times branching ratio are set. The
results are interpreted in the minimal supersymmetric standard model yielding
limits that are the most stringent to date at hadron colliders.


title:
Sequential nonparametrics and semiparametrics: Theory, implementation
  and applications to clinical trials

abstract:
  One of Pranab K. Sen's major research areas is sequential nonparametrics and
semiparametrics and their applications to clinical trials, to which he has made
many important contributions. Herein we review a number of these contributions
and related developments. We also describe some recent work on nonparametric
and semiparametric inference and the associated computational methods in
time-sequential clinical trials with survival endpoints.


title: Combinatorial cube packings in cube and torus

abstract:
  We consider sequential random packing of cubes $z+[0,1]^n$ with $z\in
\frac{1}{N}\ZZ^n$ into the cube $[0,2]^n$ and the torus $\QuotS{\RR^n}{2\ZZ^n}$
as $N\to\infty$. In the cube case $[0,2]^n$ as $N\to\infty$ the random cube
packings thus obtained are reduced to a single cube with probability
$1-O(\frac{1}{N})$. In the torus case the situation is different: for $n\leq
2$, sequential random cube packing yields cube tilings, but for $n\geq 3$ with
strictly positive probability, one obtains non-extensible cube packings.
  So, we introduce the notion of combinatorial cube packing, which instead of
depending on $N$ depend on some parameters. We use use them to derive an
expansion of the packing density in powers of $\frac{1}{N}$. The explicit
computation is done in the cube case. In the torus case, the situation is more
complicate and we restrict ourselves to the case $N\to\infty$ of strictly
positive probability. We prove the following results for torus combinatorial
cube packings: We give a general Cartesian product construction. We prove that
the number of parameters is at least $\frac{n(n+1)}{2}$ and we conjecture it to
be at most $2^n-1$. We prove that cube packings with at least $2^n-3$ cubes are
extensible. We find the minimal number of cubes in non-extensible cube packings
for $n$ odd and $n\leq 6$.


title: Rectangle groups

abstract:
  A class of groups is investigated, each of which has a fairly simple
presentation . For example the group $R = (a, b, c, d | a^3 = b^3 = c^3 = d^3 =
1, ba^{-1} =dc^{-1}, ca^{-1} = db^{-1}) $ is in the class. Such a group does
not have as a homomorphic image any group which is a 2-orbifold group or which
is a group of isometries of the reals. However it does have incompatible
splittings over subgroups which are not small. This contradicts some ideas I
had about universal JSJ decompostions for finitely presented groups over
finitely generated subgroups. Such a group also has an unstable action on an
R-tree and a cocompact action on a CAT(0) cube complex with finite cyclic point
stabilizers, and trivial edge stabilizers.


title: Spectral Geometry and the Semiclassical Approach

abstract:
  The paper is dedicated to the close analogy between these two theories - some
problems lying at the very root of Spectral Geometry are viewed in the context
of Semiclassics, and vise versa. The treatment starts from a very basic level
and gradually goes into the deep, ending up with some rather up to date
results. There are many examples concerning effective actions in QCD and String
Theory, functional determinants, first integrals from asymptotic expansions,
path quantization etc. The major theorems are only given brief explanations and
simple constructive proofs, but some rather practical formulae are obtained in
return. There is a small exercise at the end - obtaining explicit expressions
for the spectral variations of the Robin problem for a planar domain. The final
result is purely in the spirit of the familiar Sationary Perturbation Theory.
The idea for investigating this particular problem (in the context of an old
exact inverse result obtained by Guillemin and Melrose), very much motivating
most of the work, belongs to my scientific advisor Dr. Petko Nikolov.


title: Estimating medical costs from a transition model

abstract:
  Nonparametric estimators of the mean total cost have been proposed in a
variety of settings. In clinical trials it is generally impractical to follow
up patients until all have responded, and therefore censoring of patient
outcomes and total cost will occur in practice. We describe a general
longitudinal framework in which costs emanate from two streams, during sojourn
in health states and in transition from one health state to another. We
consider estimation of net present value for expenditures incurred over a
finite time horizon from medical cost data that might be incompletely
ascertained in some patients. Because patient specific demographic and clinical
characteristics would influence total cost, we use a regression model to
incorporate covariates. We discuss similarities and differences between our net
present value estimator and other widely used estimators of total medical
costs. Our model can accommodate heteroscedasticity, skewness and censoring in
cost data and provides a flexible approach to analyses of health care cost.


title:
The Ising lattice with Brascamp-Kunz boundary conditions and an external
  magnetic field

abstract:
  The partition function of the finite Ising lattice with Brascamp-Kunz
boundary conditions is calculated exactly in the absence of an external
magnetic field and for an external field i\pi/2.


title: Erice Lectures on Black Holes and Attractors

abstract:
  These lectures give an elementary introduction to the subject of four
dimensional black holes (BHs) in supergravity and the Attractor Mechanism in
the extremal case. Some thermodynamical properties are discussed and some
relevant formulae for the critical points of the BH effective potential are
given. The case of Maxwell-Einstein-axion-dilaton (super)gravity is discussed
in detail. Analogies among BH entropy and multipartite entanglement of qubits
in quantum information theory, as well moduli spaces of extremal BH attractors,
are also discussed.


title:
A synthesis model for AGN evolution: supermassive black holes growth and
  feedback modes

abstract:
  We present a comprehensive synthesis model for the AGN evolution and the
growth of supermassive black holes in the Universe. We solve the continuity
equation for SMBH mass function using the locally determined one as a boundary
condition, and the hard X-ray luminosity function as tracer of the AGN growth
rate distribution, supplemented with a luminosity-dependent bolometric
correction and an absorbing column distribution. Differently from most previous
semi-analytic and numerical models, we do not assume any specific distribution
of Eddington ratios, rather we determine it empirically by coupling the mass
and luminosity functions. SMBH show a very broad accretion rate distribution,
and we discuss the consequences of this fact for our understanding of observed
AGN fractions in galaxies. We confirm previous results and demonstrate that, at
least for z<1.5, SMBH mass function evolves anti-hierarchically, i.e. the most
massive holes grew earlier and faster than less massive ones. For the first
time, we find hints of a reversal of such a downsizing behaviour at redshifts
above the peak of the black hole accretion rate density (z~2). We also derive
tight constraints on the (mass weighted) average radiative efficiency of AGN:
we find that 0.065<\xi_0 \epsilon_{rad}< 0.07$, where \xi_0 is the local SMBH
mass density in units of 4.3x10^5 M_sun Mpc^{-3}. We trace the cosmological
evolution of the kinetic luminosity function of AGN, and find that the overall
efficiency of SMBH in converting accreted rest mass energy into kinetic power,
ranges between 3 and 5 \times 10^{-3}. Such a ``kinetic efficiency'' varies
however strongly with SMBH mass and redshift, being maximal for very massive
holes at late times, as required for the AGN feedback by many galaxy formation
models in Cosmological contexts. (Abriged)


title:
Evidence of Unconventional Universality Class in a Two-Dimensional
  Dimerized Quantum Heisenberg Model

abstract:
  The two-dimensional $J$-$J^\prime$ dimerized quantum Heisenberg model is
studied on the square lattice by means of (stochastic series expansion) quantum
Monte Carlo simulations as a function of the coupling ratio
\hbox{$\alpha=J^\prime/J$}. The critical point of the order-disorder quantum
phase transition in the $J$-$J^\prime$ model is determined as
\hbox{$\alpha_\mathrm{c}=2.5196(2)$} by finite-size scaling for up to
approximately $10 000$ quantum spins. By comparing six dimerized models we
show, contrary to the current belief, that the critical exponents of the
$J$-$J^\prime$ model are not in agreement with the three-dimensional classical
Heisenberg universality class. This lends support to the notion of nontrivial
critical excitations at the quantum critical point.