title:
Host Galaxies of Luminous Quasars: Structural Properties and the
  Fundamental Plane

abstract:
  We present stellar velocity dispersion measurements in the host galaxies of
10 luminous quasars (M_V < -23) using the Ca H&K lines in off-nuclear spectra.
We combine these data with effective radii and magnitudes from the literature
to place the host galaxies on the Fundamental Plane (FP) where their properties
are compared to other types of galaxies. We find that the radio-loud (RL) QSO
hosts have similar properties to massive elliptical galaxies, while the
radio-quiet (RQ) hosts are more similar to intermediate mass galaxies. The RL
hosts lie at the upper extreme of the FP due to their large velocity
dispersions (<sigma_*> = 321 km s^-1), low surface brightness (<mu_e(r)> = 20.8
mag arcsec^-2), and large effective radii (<R_e> = 11.4 kpc), and have <M_*> =
1.5 x 10^12 M_sun and <M/L> = 12.4. In contrast, properties of the RQ hosts are
<sigma_*> = 241 km s^-1, <M_*> ~ 4.4 x 10^11 M_sun, and <M/L> ~ 5.3. The
distinction between these galaxies occurs at sigma_* ~ 300 km s^-1, R_e ~ 6
kpc, and corresponding M_* ~ 5.9 +/- 3.5 x 10^11 M_sun. Our data support
previous results that PG QSOs are related to gas-rich galaxy mergers that form
intermediate-mass galaxies, while RL QSOs reside in massive early-type
galaxies, most of which also show signs of recent mergers or interactions. Most
previous work has drawn these conclusions by using estimates of the black hole
mass and inferring host galaxy properties from that, while here we have relied
purely on directly measured host galaxy properties.


title: Cluster Magnetic Fields from Galactic Outflows

abstract:
  We performed cosmological, magneto-hydrodynamical simulations to follow the
evolution of magnetic fields in galaxy clusters, exploring the possibility that
the origin of the magnetic seed fields are galactic outflows during the
star-burst phase of galactic evolution. To do this we coupled a semi-analytical
model for magnetized galactic winds as suggested by \citet{2006MNRAS.370..319B}
to our cosmological simulation. We find that the strength and structure of
magnetic fields observed in galaxy clusters are well reproduced for a wide
range of model parameters for the magnetized, galactic winds and do only weakly
depend on the exact magnetic structure within the assumed galactic outflows.
Although the evolution of a primordial magnetic seed field shows no significant
differences to that of galaxy clusters fields from previous studies, we find
that the magnetic field pollution in the diffuse medium within filaments is
below the level predicted by scenarios with pure primordial magnetic seed
field. We therefore conclude that magnetized galactic outflows and their
subsequent evolution within the intra-cluster medium can fully account for the
observed magnetic fields in galaxy clusters. Our findings also suggest that
measuring cosmological magnetic fields in low-density environments such as
filaments is much more useful than observing cluster magnetic fields to infer
their possible origin.


title:
A Distributed and Deterministic TDMA Algorithm for
  Write-All-With-Collision Model

abstract:
  Several self-stabilizing time division multiple access (TDMA) algorithms are
proposed for sensor networks. In addition to providing a collision-free
communication service, such algorithms enable the transformation of programs
written in abstract models considered in distributed computing literature into
a model consistent with sensor networks, i.e., write all with collision (WAC)
model. Existing TDMA slot assignment algorithms have one or more of the
following properties: (i) compute slots using a randomized algorithm, (ii)
assume that the topology is known upfront, and/or (iii) assign slots
sequentially. If these algorithms are used to transform abstract programs into
programs in WAC model then the transformed programs are probabilistically
correct, do not allow the addition of new nodes, and/or converge in a
sequential fashion. In this paper, we propose a self-stabilizing deterministic
TDMA algorithm where a sensor is aware of only its neighbors. We show that the
slots are assigned to the sensors in a concurrent fashion and starting from
arbitrary initial states, the algorithm converges to states where
collision-free communication among the sensors is restored. Moreover, this
algorithm facilitates the transformation of abstract programs into programs in
WAC model that are deterministically correct.


title:
Observations of the Gas Reservoir around a Star Forming Galaxy in the
  Early Universe

abstract:
  We present a high signal-to-noise spectrum of a bright galaxy at z = 4.9 in
14 h of integration on VLT FORS2. This galaxy is extremely bright, i_850 =
23.10 +/- 0.01, and is strongly-lensed by the foreground massive galaxy cluster
Abell 1689 (z=0.18). Stellar continuum is seen longward of the Ly-alpha
emission line at ~7100 \AA, while intergalactic H I produces strong absorption
shortward of Ly-alpha. Two transmission spikes at ~6800 Angstroms (A) and ~7040
A are also visible, along with other structures at shorter wavelengths.
Although fainter than a QSO, the absence of a strong central ultraviolet flux
source in this star forming galaxy enables a measurement of the H I flux
transmission in the intergalactic medium (IGM) in the vicinity of a high
redshift object. We find that the effective H I optical depth of the IGM is
remarkably high within a large 14 Mpc (physical) region surrounding the galaxy
compared to that seen towards QSOs at similar redshifts. Evidently, this
high-redshift galaxy is located in a region of space where the amount of H I is
much larger than that seen at similar epochs in the diffuse IGM. We argue that
observations of high-redshift galaxies like this one provide unique insights on
the nascent stages of baryonic large-scale structures that evolve into the
filamentary cosmic web of galaxies and clusters of galaxies observed in the
present universe.


title:
Spectroscopy of globular clusters in the low-luminosity spiral galaxy
  NGC 45

abstract:
  CONTEXT: Extragalactic globular clusters have been studied in elliptical
galaxies and in a few luminous spiral galaxies, but little is known about
globular clusters in low-luminosity spirals.
  AIMS: Past observations with the ACS have shown that NGC 45 hosts a large
population of globular clusters (19), as well as several young star clusters.
In this work we aim to confirm the bona fide globular cluster status for 8 of
19 globular cluster candidates and to derive metallicities, ages, and
velocities.
  METHODS: VLT/FORS2 multislit spectroscopy in combination with the Lick/IDS
system was used to derive velocities and to constrain metallicities and
[alpha/Fe] element ratio of the globular clusters.
  RESULTS: We confirm the 8 globular clusters as bona fide globular clusters.
Their velocities indicate halo or bulge-like kinematics, with little or no
overall rotation. From absorption indices such as H_beta, H_gamma, and H_delta
and the combined [MgFe]' index, we found that the globular clusters are
metal-poor [Z/H]<=-0.33 dex and [alpha/Fe]<=0.0 element ratio. These results
argue in favor of a population of globular clusters formed during the
assembling of the galaxy.


title: ZZ boundary states and fragmented AdS2 spaces

abstract:
  In this paper we show that Liouville gravity on the strip with
Zamolodchikov-Zamolodchikov (ZZ) boundary conditions has a semi-classical
interpretation in terms of fragmented AdS2 spacetime geometries. Further, we
study the three-point functions of the ZZ boundary states, and show that they
are dominated by multi-AdS2 instantons in the classical limit.


title:
Magnetism from $2p$ States in Alkaline Earth Monoxides: Trends with
  Varying N Impurity Concentration

abstract:
  $2p$-based magnetic moments and magnetic coupling are studied with density
functional based methods for substitutional N in the alkaline earth monoxide
series MgO, CaO, SrO, BaO. The hole is rather strongly localized near the
N$^{2-}$ ion, being somewhat more so when strong on-site interactions are
included in the calculations. Strong magnetic coupling is obtained in the
itinerant electron limit but decreases strongly in the localized limit in which
the Coulomb repulsion within the N $2p$ shell (U) is much greater than the N
$2p$ impurity bandwidth (W). We find that this limit is appropriate for
realistic N concentrations. Ordering on a simple cubic sublattice may maximize
the magnetic coupling due to its high directionality.


title:
The simulated 21 cm signal during the epoch of reionization : full
  modeling of the Ly-alpha pumping

abstract:
  The 21 cm emission of neutral hydrogen is the most promising probe of the
epoch of reionization(EoR). In the next few years, the SKA pathfinders will
provide statistical measurements of this signal. Numerical simulations
predicting these observations are necessary to optimize the design of the
instruments. The main difficulty is the computation of the spin temperature of
neutral hydrogen which depends on the gas kinetic temperature and on the level
of the local Lyman-alpha flux. A T_s >> T_cmb assumption is usual. However,
this assumption does not apply early in the reionization history, or even later
in the history as long as the sources of X-rays are too weak to heat the
intergalactic medium significantly. This work presents the first EoR numerical
simulations including, beside dynamics and ionizing continuum radiative
transfer, a self-consistent treatment of the Ly-alpha radiative transfer. This
allows us to compute the spin temperature more accurately. We use two different
box sizes, 20 Mpc/h and 100 Mpc/h, and a star source model. Using the redshift
dependence of average quantities, maps, and power spectra, we quantify the
effect of using different assumptions to compute the spin temperature and the
influence of the box size. The first effect comes from allowing for a signal in
absorption. The magnitude of this effect depends on the amount of heating by
hydrodynamic shocks and X-rays in the intergalactic medium(IGM). The second
effects comes from using the real, local, Lyman-alpha flux. This effect is
important for an average ionization fraction of less than 10%: it changes the
overall amplitude of the 21 cm signal, and adds its own fluctuations to the
power spectrum.


title: A New FUSE Survey of Interstellar HD

abstract:
  We have used archival FUSE data to complete a survey of interstellar HD in 41
lines of sight with a wide range of extinctions. This follow up to an earlier
survey was made to further assess the utility of HD as a cosmological probe; to
analyze the HD formation process; and to see what trends with other
interstellar properties were present in the data. We employed the
curve-of-growth method, supported by line profile fitting, to derive accurate
column densities of HD. We find that the N(HD)/2N(H2) ratio is substantially
lower than the atomic D/H ratio and conclude that the molecular ratio has no
bearing on cosmology, because local processes are responsible for the formation
of HD. Based on correlations with E(B-V), H2, CO, and iron depletion, we find
that HD is formed in the densest portion of the clouds; the slope of the
logN(HD)/log(H2) correlation is greater than 1.0, caused by the destruction
rate of HD declining more slowly than that of H2; and, as a sidelight, that the
depletions are density dependent.


title:
Another chiral critical end-point induced by neutral color
  superconductivity

abstract: This paper has been withdrawn by the authors, due to it's incompleteness.


title: Proof of Han's Hook Expansion Conjecture

abstract:
  We prove a conjecture by Guo-Niu Han which interpolates between two known
hook expansion formulas.


title:
Kondo Effect and Spin Glass Behavior of Dilute Iron Clusters in Silver
  Studied by M\"{o}ssbauer Spectroscopy and Resistivity

abstract:
  Thin films of silver containing 0.3 - 1.5 at % Fe have been prepared by vapor
co-deposition. Depending on substrate temperature and iron concentration we
could systematically follow the formation of nanometer size clusters of iron
from initially dilute iron monomers. samples were characterized via X-ray
diffraction, resistivity and M\"{o}ssbauer spectroscopic measurements. The
magnetic behavior derived from M\"{o}ssbauer data can be best described with an
ensemble of ferromagnetic mono-domain particles. The magnetic freezing observed
at low temperatures, is controlled via the inter-particle interactions mediated
via conduction electron polarization, i.e. RKKY interaction. The interaction of
the cluster magnetic moments with the conduction electron sea is best
quantified by the electrical resistivity data. For all studied concentrations
we find a non-monotonic variation with temperature which can be understood by
competing shielding of the cluster moments by conduction electron spin
scattering due to Kondo effect and the magnetic coupling.


title: A Line-Of-Sight Galaxy Cluster Collision: Simulated X-Ray Observations

abstract:
  Several lines of evidence have suggested that the the galaxy cluster
Cl~0024+17, an apparently relaxed system, is actually a collision of two
clusters, the interaction occurring along our line of sight. In this paper we
present a high-resolution $N$-body/hydrodynamics simulation of such a
collision. We have created mock X-ray observations of our simulated system
using MARX, a program that simulates the on-orbit performance of the Chandra
X-ray Observatory. We analyze these simulated data to generate radial profiles
of the surface brightness and temperature. At later times, $t = 2.0-3.0$ Gyr
after the collision, the simulated surface brightness profiles are better fit
by a superposition of two $\beta$-model profiles than a single profile, in
agreement with the observations of Cl~0024+17. In general, due to projection
effects, much of the post-collision density and temperature structure of the
clusters is not seen in the observations. In particular, the observed
temperatures from spectral fitting are much lower than the temperature of the
hottest gas. We determine from our fitted profiles that if the system is
modeled as a single cluster, the hydrostatic mass estimate is a factor
$\sim$2-3 less than the actual mass, but if the system is modeled as two galaxy
clusters in superposition, a hydrostatic mass estimation can be made which is
accurate to within $\sim$10%. We examine some implications of these results for
galaxy cluster X-ray surveys.


title: Dynamical polarization, screening, and plasmons in gapped graphene

abstract:
  The one-loop polarization function of graphene has been calculated at zero
temperature for arbitrary wavevector, frequency, chemical potential (doping),
and band gap. The result is expressed in terms of elementary functions and is
used to find the dispersion of the plasmon mode and the static screening within
the random phase approximation. At long wavelengths the usual square root
behaviour of plasmon spectra for two-dimensional (2D) systems is obtained. The
presence of a small (compared to a chemical potential) gap leads to the
appearance of a new undamped plasmon mode. At greater values of the gap this
mode merges with the long-wavelength one, and vanishes when the Fermi level
enters the gap. The screening of charged impurities at large distances differs
from that in gapless graphene by slower decay of Friedel oscillations ($1/r^2$
instead of $1/r^3$), similarly to conventional 2D systems.


title: First Resolved Images of the Eclipsing and Interacting Binary Beta Lyrae

abstract:
  We present the first resolved images of the eclipsing binary Beta Lyrae,
obtained with the CHARA Array interferometer and the MIRC combiner in the H
band. The images clearly show the mass donor and the thick disk surrounding the
mass gainer at all six epochs of observation. The donor is brighter and
generally appears elongated in the images, the first direct detection of
photospheric tidal distortion due to Roche-lobe filling. We also confirm
expectations that the disk component is more elongated than the donor and is
relatively fainter at this wavelength. Image analysis and model fitting for
each epoch were used for calculating the first astrometric orbital solution for
Beta Lyrae, yielding precise values for the orbital inclination and position
angle. The derived semi-ma jor axis also allows us to estimate the distance of
Beta Lyrae; however, systematic differences between the models and the images
limit the accuracy of our distance estimate to about 15%. To address these
issues, we will need a more physical, self-consistent model to account for all
epochs as well as the multi-wavelength information from the eclipsing light
curves.


title: Observation of chi-b(1PJ,2PJ) decays to light hadrons

abstract:
  Analyzing $\Upsilon(nS)$ decays acquired with the CLEO detector operating at
the CESR $e^+e^-$ collider, we measure for the first time the product branching
fractions ${\cal B}[\Upsilon(nS)\to\gamma\chi_{b}((n-1)P_J)] \times {\cal
B}[\chi_{b}(n-1)P_J)\to X_i]$ for $n=2$ and 3, where $X_i$ denotes, for each
$i$, one of the fourteen exclusive light-hadron final states for which we
observe significant signals in both $\chi_b(1P_J)$ and $\chi_b(2P_J)$ decays.
We also determine upper limits for the electric dipole (E1) transitions
$\Upsilon(3S) \to \gamma \chi_b(1P_J)$.


title: Triangles of Baumslag-Solitar Groups

abstract:
  Our main result is that many triangles of Baumslag-Solitar groups collapse to
finite groups, generalizing a famous example of Hirsch. A triangle of
Baumslag-Solitar groups means a group with three generators, cyclically
ordered, with each generator conjugating some power of the previous one to
another power. There are six parameters, occurring in pairs, and we show that
the triangle fails to be developable whenever one of the parameters divides its
partner, except for a few special cases. Furthermore, under fairly general
conditions, the group turns out to be finite and solvable of class<4. We obtain
a lot of information about finite quotients, even when we cannot determine
developability.


title:
Tailor-made Quantum Well-in-a-Well Systems: Their Bound States and
  Scattering Properties

abstract:
  The resulting stationary states and scattering properties of an effective
potential brought about by embedding a quantum well in another well are
investigated in this work. The composite well system is constructed via a
superposition of modified Poeschl - Teller potential wells. The energy spectrum
in each composite well is obtained using the shooting method and the transport
of a particle above this system is analyzed using the transfer matrix method.
It is shown that decreasing the size of the embedded middle well lowers the
ground state energy of the well-in-a-well system. Moreover, the bound states
increase in number and become more evenly spaced. In addition, the transmission
probability of a free particle incident above a composite well is lowest for
the system with a large embedded well as compared to well-in-a-well systems of
the same depth. Small variations in designed potential wells yield different
quantum mechanical features.


title: Preheating with Non-Standard Kinetic Term

abstract:
  We consider reheating after inflation in theories with a non-standard kinetic
term. We show that the equation that exhibits parametric resonance is the
Hill-Whittaker equation, which is a particular case of the more general Hill
equation. This equation is in general more unstable than the Mathieu equation,
such that narrow resonance preheating may be efficient in theories with a
non-canonical kinetic term.


title: Derivation of effective field theories

abstract:
  A general self-consistency approach allows a thorough treatment of the
corrections to the mean-field approximation (MFA). The natural extension of
standard MFA with the help of a cumulant expansion leads to a new point of view
on the effective field theories. The proposed approach can be used for a
systematic treatment of fluctuation effects of various length scales and,
perhaps, for the development of a new coarse graining procedure. We outline and
justify our method by some preliminary calculations. Results are given for the
critical temperature and the Landau parameters of the $\phi^4$-theory -- the
field counterpart of the Ising model. An important unresolved problem of the
modern theory of phase transitions -- the problem for the calculation of the
true critical temperature, is considered within the framework of the present
approach. A comprehensive description of the ground state properties of
many-body systems is also demonstrated.


title: Geometric Entanglement in a One-Dimensional Valence Bond Solid State

abstract:
  In this paper we provide the analytical derivation of the global geometric
entanglement per block for the valence bond solid ground state of the spin-1
AKLT chain. In particular, we show that this quantity saturates exponentially
fast to a constant when the sizes of the blocks are sufficiently large. Our
result provides the first known example of an analytical calculation of the
geometric entanglement for a gapped quantum many-body system in one dimension
and far away from a quantum critical point.


title:
On the phase diagrams of the ferromagnetic superconductors ZrZn2 and
  UGe2

abstract:
  A general phenomenological theory is presented for the phase behavior of
ferromagnetic superconductors with spin-triplet electron Cooper pairing. The
theory accounts in detail for the temperature-pressure phase diagram of
ZrZn$_2$, while the main features of the diagram for UGe$_2$ are also
described. Quantitative criteria are deduced for the U-type (type I) and
Zr-type (type II) unconventional ferromagnetic superconductors with
spin-triplet Cooper electron pairing. Some basic properties of quantum phase
transitions are also elucidated.

categories: cond-mat.supr-con astro-ph cond-mat.mtrl-sci cond-mat.str-el quant-ph


title: Corrigendum to "Knot Floer homology detects fibred knots"

abstract:
  We correct a mistake on the citation of JSJ theory in \cite{Ni}. Some
arguments in \cite{Ni} are also slightly modified accordingly.


title: One-Loop Multi-Parton Amplitudes with a Vector Boson for the LHC

abstract:
  In this talk, we present the first, numerically stable, results for the
one-loop amplitudes needed for computing W,Z + 3 jet cross sections at the LHC
to next-to-leading order in the QCD coupling. We implemented these processes in
BlackHat, an automated program based on on-shell methods. These methods scale
very well with increasing numbers of external partons, and are applicable to a
wide variety of problems of phenomenological interest at the LHC.


title:
Dissipative and nonequilibrium effects near a superconductor-metal
  quantum critical point

abstract:
  We present a microscopic derivation of the effect of current flow on a system
near a superconductor-metal quantum critical point. The model studied is a 2d
itinerant electron system where the electrons interact via an attractive
interaction and are coupled to an underlying normal metal substrate which
provides a source of dissipation, and also provides a source of inelastic
scattering that allows a nonequilibrium steady state to reach. A nonequilibrium
Keldysh action for the superconducting fluctuations on the normal side is
derived. Current flow, besides its minimal coupling to the order parameter is
found to give rise to two new effects. One is a source of noise that acts as an
effective temperature $T_{eff} = e E v_F \tau_{sc}$ where $E$ is the external
electric field, $v_F$ the Fermi velocity, and $\tau_{sc}$ is the escape time
into the normal metal substrate. Secondly current flow also produces a drift of
the order-parameter. Scaling equations for the superconducting gap and the
current are derived and are found to be consistent with previous
phenomenological treatments as long as a temperature $T \sim T_{eff}$ is
included. The current induced drift is found to produce additional corrections
to the scaling which are smaller by a factor of ${\cal O}(\frac{1}{E_F
\tau_{sc}})$, $E_F$ being the Fermi energy.


title: Noncommutative Corrections to the Robertson-Walker metric

abstract:
  Upon applying Chamseddine's noncommutative deformation of gravity we obtain
the leading order noncommutative corrections to the Robertson-Walker metric
tensor. We get an isotropic inhomogeneous metric tensor for a certain choice of
the noncommutativity parameters. Moreover, the singularity of the commutative
metric at $t=0$ is replaced by a more involved space-time structure in the
noncommutative theory. In a toy model we construct a scenario where there is no
singularity at $t=0$ at leading order in the noncommutativity parameter.
Although singularities may still be present for nonzero $t$, they need not be
the source of all time-like geodesics and the result resembles a bouncing
cosmology.


title: Improving Quantum State Estimation with Mutually Unbiased Bases

abstract:
  When used in quantum state estimation, projections onto mutually unbiased
bases have the ability to maximize information extraction per measurement and
to minimize redundancy. We present the first experimental demonstration of
quantum state tomography of two-qubit polarization states to take advantage of
mutually unbiased bases. We demonstrate improved state estimation as compared
to standard measurement strategies and discuss how this can be understood from
the structure of the measurements we use. We experimentally compared our method
to the standard state estimation method for three different states and observe
that the infidelity was up to 1.84+/-0.06 times lower using our technique than
it was using standard state estimation methods.


title:
Probing the ZZgamma and Zgammagamma Couplings Through the Process e+e-
  --> nu anti-nu gamma

abstract:
  We study the sensitivity for testing the anomalous triple gauge couplings
$ZZ\gamma$ and $Z\gamma\gamma$ via the process $e^+e^-\to \nu \bar\nu \gamma$
at high energy linear colliders. For integrated luminosities of 500 $fb^{-1}$
and center of mass energies between 0.5 and 1.5 $TeV$, we find that this
process can provide tests of the triple neutral gauge boson couplings of order
$10^{-4}$, one order of magnitude lower than the standard model prediction.


title: Contributions to Seymour's Second Neighborhood Conjecture

abstract:
  Let D be a simple digraph without loops or digons. For any v in V(D) let
N_1(v) be the set of all nodes at out-distance 1 from v and let N_2(v) be the
set of all nodes at out-distance 2. We provide sufficient conditions under
which there must exist some v in V(D) such that |N_1(v)| is less than or equal
to |N_2(v)|, as well as examine properties of a minimal graph which does not
have such a node. We show that if one such graph exists, then there exist
infinitely many strongly-connected graphs having no such vertex.


title: Suppressed conductance in a metallic graphene nano-junction

abstract:
  The linear conductance spectrum of a metallic graphene junction formed by
interconnecting two gapless graphene nanoribbons is calculated. A strong
conductance suppression appears in the vicinity of the Dirac point. We found
that such a conductance suppression arises from the antiresonance effect
associated with the edge state localized at the zigzag-edged shoulder of the
junction. The conductance valley due to the antiresonance is rather robust in
the presence of the impurity and vacancy scattering. And the center of the
conductance valley can be readily tuned by an electric field exerted on the
wider nanoribbon.


title: Capacity of a Class of Diamond Channels

abstract:
  We study a special class of diamond channels which was introduced by Schein
in 2001. In this special class, each diamond channel consists of a transmitter,
a noisy relay, a noiseless relay and a receiver. We prove the capacity of this
class of diamond channels by providing an achievable scheme and a converse. The
capacity we show is strictly smaller than the cut-set bound. Our result also
shows the optimality of a combination of decode-and-forward (DAF) and
compress-and-forward (CAF) at the noisy relay node. This is the first example
where a combination of DAF and CAF is shown to be capacity achieving. Finally,
we note that there exists a duality between this diamond channel coding problem
and the Kaspi-Berger source coding problem.


title: Critical behaviour in quantum gravitational collapse

abstract:
  We study the gravitational collapse of an inhomogeneous scalar field with
quantum gravity corrections associated with singularity avoidance. Numerical
simulations indicate that there is critical behaviour at the onset of black
hole formation as in the classical theory, but with the difference that black
holes form with a mass gap.


title: Tunable pure spin currents in a triple-quantum-dot ring

abstract:
  Electron transport properties in a triple-quantum-dot ring with three
terminals are theoretically studied. By introducing local Rashba spin-orbit
interaction on an individual quantum dot, we calculate the charge and spin
currents in one lead. We find that a pure spin current appears in the absence
of a magnetic field. The polarization direction of the spin current can be
inverted by altering the bias voltage. In addition, by tuning the magnetic
field strength, the charge and spin currents reach their respective peaks
alternately.


title:
A minimal set of invariants as a systematic approach to higher order
  gravity models

abstract:
  Higher-order gravity models have been recently the subject of much attention
in the context of cosmic acceleration. These models are derived by adding
various curvature invariants to the Einstein-Hilbert action. Several studies
showed that these models can have late-time self-acceleration and could, in
some cases, fit various observational constraints. In view of the infinite
spectrum of invariants that could be built from curvature tensors, we propose
here a method based on minimal sets of independent invariants as a possible
route for a systematic approach to these models. We explore a connection made
between theorems on bases in invariants theory in relativity and higher-order
cosmological models. A dynamical system analysis is performed and some models
with accelerating attractors are discussed. The asymptotic behavior of the
models is also studied using analytical calculations.


title:
Phenomenological model for two gap states in underdoped high-temperature
  superconductors and short-range antiferromagnetic correlation effect

abstract:
  Assuming antiferromagnetic orbital correlations to model the pseudogap state
in the underdoped high-temperature superconductors, we study how this
correlation is distinguished from the d-wave superconductivity correlation with
including the finite-range antiferromagnetic correlation effect. In spite of
the fact that both correlations have the same d-wave symmetry, the
contributions from each correlation is clearly distinguished in the spectral
weight and the density of states.


title:
The applicability of causal dissipative hydrodynamics to relativistic
  heavy ion collisions

abstract:
  We utilize nonequilibrium covariant transport theory to determine the region
of validity of causal Israel-Stewart dissipative hydrodynamics (IS) and
Navier-Stokes theory (NS) for relativistic heavy ion physics applications. A
massless ideal gas with 2->2 interactions is considered in a 0+1D Bjorken
scenario, appropriate for the early longitudinal expansion stage of the
collision. In the scale invariant case of a constant shear viscosity to entropy
density ratio eta/s ~ const, we find that Israel-Stewart theory is 10% accurate
in calculating dissipative effects if initially the expansion timescale exceeds
half the transport mean free path tau0/lambda0 > ~2. The same accuracy with
Navier-Stokes requires three times larger tau0/lambda0 > ~6. For dynamics
driven by a constant cross section, on the other hand, about 50% larger
tau0/lambda0 > ~3 (IS) and ~9 (NS) are needed. For typical applications at RHIC
energies s_{NN}**(1/2) ~ 100-200 GeV, these limits imply that even the
Israel-Stewart approach becomes marginal when eta/s > ~0.15. In addition, we
find that the 'naive' approximation to Israel-Stewart theory, which neglects
products of gradients and dissipative quantities, has an even smaller range of
applicability than Navier-Stokes. We also obtain analytic Israel-Stewart and
Navier-Stokes solutions in 0+1D, and present further tests for numerical
dissipative hydrodynamics codes in 1+1, 2+1, and 3+1D based on generalized
conservation laws.


title: Achievable rate regions for bi-directional relaying

abstract:
  In a bi-directional relay channel, two nodes wish to exchange independent
messages over a shared wireless half-duplex channel with the help of a relay.
In this paper, we derive achievable rate regions for four new half-duplex
protocols and compare these to four existing half-duplex protocols and outer
bounds. In time, our protocols consist of either two or three phases. In the
two phase protocols, both users simultaneously transmit during the first phase
and the relay alone transmits during the second phase, while in the three phase
protocol the two users sequentially transmit followed by a transmission from
the relay. The relay may forward information in one of four manners; we outline
existing Amplify and Forward (AF), Decode and Forward (DF) and Compress and
Forward (CF) relaying schemes and introduce the novel Mixed Forward scheme. The
latter is a combination of CF in one direction and DF in the other. We derive
achievable rate regions for the CF and Mixed relaying schemes for the two and
three phase protocols. In the last part of this work we provide a comprehensive
treatment of 8 possible half-duplex bi-directional relaying protocols in
Gaussian noise, obtaining their respective achievable rate regions, outer
bounds, and their relative performance under different SNR and relay
geometries.


title: Unitary orbits in a full matrix algebra

abstract:
  The Hilbert manifold $\Sigma$ consisting of positive invertible (unitized)
Hilbert-Schmidt operators has a rich structure and geometry. The geometry of
unitary orbits $\Omega\subset \Sigma$ is studied from the topological and
metric viewpoints: we seek for conditions that ensure the existence of a smooth
local structure for the set $\Omega$, and we study the convexity of this set
for the geodesic structures that arise when we give $\Sigma$ two Riemannian
metrics.


title: Unwrapping Closed Timelike Curves

abstract:
  Closed timelike curves (CTCs) appear in many solutions of the Einstein
equation, even with reasonable matter sources. These solutions appear to
violate causality and so are considered problematic. Since CTCs reflect the
global properties of a spacetime, one can attempt to change its topology,
without changing its geometry, in such a way that the former CTCs are no longer
closed in the new spacetime. This procedure is informally known as unwrapping.
However, changes in global identifications tend to lead to local effects, and
unwrapping is no exception, as it introduces a special kind of singularity,
called quasi-regular. This "unwrapping" singularity is similar to the string
singularities. We give two examples of unwrapping of essentially 2+1
dimensional spacetimes with CTCs, the Gott spacetime and the Godel universe. We
show that the unwrapped Gott spacetime, while singular, is at least devoid of
CTCs. In contrast, the unwrapped Godel spacetime still contains CTCs through
every point. A "multiple unwrapping" procedure is devised to remove the
remaining circular CTCs. We conclude that, based on the two spacetimes we
investigated, CTCs appearing in the solutions of the Einstein equation are not
simply a mathematical artifact of coordinate identifications, but are indeed a
necessary consequence of General Relativity, provided only that we demand these
solutions do not possess naked quasi-regular singularities.


title: Quarkonium transport in thermal AdS/CFT

abstract:
  We consider a heavy meson moving slowly through high temperature non-abelian
plasmas. Using a simple dipole effective Lagrangian, we calculate the in-medium
mass shift and the drag coefficient of the meson in $\N=4$ Super Yang Mills
theory at weak and strong coupling. As anticipated, in the large $N$ limit the
mass shift is finite while the drag is suppressed by $1/N^2$ . After comparing
results to perturbative QCD estimates (which are also calculated), we reach the
conclusion that relative to weak coupling expectations the effect of strong
coupling is to reduce the momentum diffusion rate and to {\it increase} the
relaxation time by up to a factor of four.


title:
On the complete integrability and linearization of nonlinear ordinary
  differential equations - Part III: Coupled first order equations

abstract:
  Continuing our study on the complete integrability of nonlinear ordinary
differential equations, in this paper we consider the integrability of a system
of coupled first order nonlinear ordinary differential equations (ODEs) of both
autonomous and non-autonomous types. For this purpose, we modify the original
Prelle-Singer procedure so as to apply it to both autonomous and non-autonomous
systems of coupled first order ODEs. We briefly explain the method of finding
integrals of motion (time independent as well as time dependent integrals) for
two and three coupled first order ODEs by extending the Prelle-Singer(PS)
method. From this we try to answer some of the open questions in the original
PS method. We also identify integrable cases for the two dimensional
Lotka-Volterra system and three-dimensional R$\ddot{o}$ssler system as well as
other examples including non-autonomous systems in a straightforward way using
this procedure. Finally, we develop a linearization procedure for coupled first
order ODEs.


title: The dual role of shear in large-scale dynamos

abstract:
  The role of shear in alleviating catastrophic quenching by shedding
small-scale magnetic helicity through fluxes along contours of constant shear
is discussed. The level of quenching of the dynamo effect depends on the
quenched value of the turbulent magnetic diffusivity. Earlier estimates that
might have suffered from the force-free degeneracy of Beltrami fields are now
confirmed for shear flows where this degeneracy is lifted. For a dynamo that is
saturated near equipartition field strength those estimates result in a 5-fold
decrease of the magnetic diffusivity as the magnetic Reynolds number based on
the wavenumber of the energy-carrying eddies is increased from 2 to 600.
Finally, the role of shear in driving turbulence and large-scale fields by the
magneto-rotational instability is emphasized. New simulations are presented and
the 3pi/4 phase shift between poloidal and toroidal fields is confirmed. It is
suggested that this phase shift might be a useful diagnostic tool in
identifying mean-field dynamo action in simulations and to distinguish this
from other scenarios invoking magnetic buoyancy as a means to explain migration
away from the midplane.


title: Turbulent protostellar discs

abstract:
  Aspects of turbulence in protostellar accretion discs are being reviewed. The
emergence of dead zones due to poor ionization and alternatives to the
magneto-rotational instability are discussed. The coupling between dust and gas
in protostellar accretion discs is explained and turbulent drag is compared
with laminar drag in the Stokes and Epstein regimes. Finally, the significance
of magnetic field generation in turbulent discs is emphasized in connection
with driving outflows and with star-disc coupling.


title: Large-scale dynamos at low magnetic Prandtl numbers

abstract:
  Using direct simulations of hydromagnetic turbulence driven by random
polarized waves it is shown that dynamo action is possible over a wide range of
magnetic Prandtl numbers from 10^-3 to 1. Triply periodic boundary conditions
are being used. In the final saturated state the resulting magnetic field has a
large-scale component of Beltrami type. For the kinematic phase, growth rates
have been determined for magnetic Prandtl numbers between 0.01 and 1, but only
the case with the smallest magnetic Prandtl number shows large-scale magnetic
fields. It is less organized than in the nonlinear stage. For small magnetic
Prandtl numbers the growth rates are comparable to those calculated from an
alpha squared mean-field dynamo. In the linear regime the magnetic helicity
spectrum has a short inertial range compatible with a -5/3 power law, while in
the nonlinear regime it is the current helicity whose spectrum may be
compatible with such a law. In the saturated case, the spectral magnetic energy
in the inertial range is in slight excess over the spectral kinetic energy,
although for small magnetic Prandtl numbers the magnetic energy spectrum
reaches its resistive cut off wavenumber more quickly. The viscous energy
dissipation declines with the square root of the magnetic Prandtl number, which
implies that most of the energy is dissipated via Joule heat.


title:
Verification of Peterson's Algorithm for Leader Election in a
  Unidirectional Asynchronous Ring Using NuSMV

abstract:
  The finite intrinsic nature of the most distributed algorithms gives us this
ability to use model checking tools for verification of this type of
algorithms. In this paper, I attempt to use NuSMV as a model checking tool for
verifying necessary properties of Peterson's algorithm for leader election
problem in a unidirectional asynchronous ring topology. Peterson's algorithm
for an asynchronous ring supposes that each node in the ring has a unique ID
and also a queue for dealing with storage problem. By considering that the
queue can have any combination of values, a constructed model for a ring with
only four nodes will have more than a billion states. Although it seems that
model checking is not a feasible approach for this problem, I attempt to use
several effective limiting assumptions for hiring formal model checking
approach without losing the correct functionality of the Peterson's algorithm.
These enforced limiting assumptions target the degree of freedom in the model
checking process and significantly decrease the CPU time, memory usage and the
total number of page faults. By deploying these limitations, the number of
nodes can be increased from four to eight in the model checking process with
NuSMV.


title: A parallel algorithm for the enumeration of benzenoid hydrocarbons

abstract:
  We present an improved parallel algorithm for the enumeration of fixed
benzenoids B_h containing h hexagonal cells. We can thus extend the enumeration
of B_h from the previous best h=35 up to h=50. Analysis of the associated
generating function confirms to a very high degree of certainty that $B_h \sim
A \kappa^h /h$ and we estimate that the growth constant $\kappa =
5.161930154(8)$ and the amplitude $A=0.2808499(1)$.


title: On the Euler Numbers and its Applications

abstract:
  Recently the new q-Euler numbers are defined. In this paper we derive the the
Kummer type congruence related to q-Euler numbers and we introduce some
interesting formulae related to these q-Euler numbers.


title: Pyrophosphate Groups in Liquid Crystalline Phases of the DNA

abstract:
  We study electrostatic interaction between molecules of the DNA in which a
number of phosphate groups of the sugar-phosphate backbone are exchanged for
the pyrophosphate ones. We employ a model in which the DNA is considered as a
one-dimensional lattice of dipoles and charges corresponding to base pairs and
(pyro)phosphate groups, respectively. The interaction between molecules of the
DNA is described by a pair potential $U$ of electrostatic forces between the
two sets of dipoles and charges belonging to respective lattices describing the
molecules. Minima of potential $U$ indicate orientational ordering of the
molecules and thus liquid crystalline phases of the DNA. We use numerical
methods for finding the set of minima in conjunction with symmetries verified
by potential $U$. The symmetries form a noncommutative group of 8-th order,
${\cal S}$. Using the group ${\cal S}$ we suggest a classification of liquid
crystalline phases of the DNA, which allows of several cholesteric phases, that
is polymorphism. Pyrophosphate forms of the DNA could clarify the part played
by charges in its liquid crystalline phases, and make for experimental
research, important for nano-technological and bio-medical applications.


title:
Extinction of impurity resonances in large-gap regions of inhomogeneous
  d-wave superconductors

abstract:
  Impurity resonances observed by scanning tunneling spectroscopy in the
superconducting state have been used to deduce properties of the underlying
pure state. Here we study a longstanding puzzle associated with these
measurements, the apparent extinction of these resonances for Ni and Zn
impurities in large-gap regions of the inhomogeneous BSCCO superconductor. We
calculate the effect of order parameter and hopping suppression near the
impurity site, and find that these two effects are sufficient to explain the
missing resonances in the case of Ni. There are several possible scenarios for
the extinction of the Zn resonances, which we discuss in turn; in addition, we
propose measurements which could distinguish among them.


title:
The sparsity and bias of the Lasso selection in high-dimensional linear
  regression

abstract:
  Meinshausen and Buhlmann [Ann. Statist. 34 (2006) 1436--1462] showed that,
for neighborhood selection in Gaussian graphical models, under a neighborhood
stability condition, the LASSO is consistent, even when the number of variables
is of greater order than the sample size. Zhao and Yu [(2006) J. Machine
Learning Research 7 2541--2567] formalized the neighborhood stability condition
in the context of linear regression as a strong irrepresentable condition. That
paper showed that under this condition, the LASSO selects exactly the set of
nonzero regression coefficients, provided that these coefficients are bounded
away from zero at a certain rate. In this paper, the regression coefficients
outside an ideal model are assumed to be small, but not necessarily zero. Under
a sparse Riesz condition on the correlation of design variables, we prove that
the LASSO selects a model of the correct order of dimensionality, controls the
bias of the selected model at a level determined by the contributions of small
regression coefficients and threshold bias, and selects all coefficients of
greater order than the bias of the selected model. Moreover, as a consequence
of this rate consistency of the LASSO in model selection, it is proved that the
sum of error squares for the mean response and the $\ell_{\alpha}$-loss for the
regression coefficients converge at the best possible rates under the given
conditions. An interesting aspect of our results is that the logarithm of the
number of variables can be of the same order as the sample size for certain
random dependent designs.


title:
On the complete integrability and linearization of nonlinear ordinary
  differential equations - Part IV: Coupled second order equations

abstract:
  Coupled second order nonlinear differential equations are of fundamental
importance in dynamics. In this part of our study on the integrability and
linearization of nonlinear ordinary differential equations we focus our
attention on the method of deriving general solution of two coupled second
order nonlinear ordinary differential equations through the extended
Prelle-Singer procedure. We describe a procedure to obtain integrating factors
and required number of integrals of motion so that the general solution follows
straightforwardly from these integrals. Our method tackles both isotropic and
non-isotropic cases in a systematic way. In addition to the above, we introduce
a new method of transforming coupled second order nonlinear ODEs into uncoupled
ones. We illustrate the theory with potentially important examples.


title:
On the complete integrability and linearization of nonlinear ordinary
  differential equations - Part V: Linearization of coupled second order
  equations

abstract:
  Linearization of coupled second order nonlinear ordinary differential
equations (SNODEs) is one of the open and challenging problems in the theory of
differential equations. In this paper we describe a simple and straightforward
method to derive linearizing transformations for a class of two coupled SNODEs.
Our procedure gives several new types of linearizing transformations of both
invertible and non-invertible kinds. In both the cases we provide algorithms to
derive the general solution of the given SNODE. We illustrate the theory with
potentially important examples.


title: Diffraction and forward physics: from HERA to LHC

abstract:
  I discuss and connect a number of topics in small-x physics at HERA and at
LHC, pointing out recent progress and open questions in theory and
phenomenology.


title: Dalitz Plot Analysis of D_s+ -> pi+ pi- pi+

abstract:
  A Dalitz plot analysis of approximately 13,000 Ds+ decays to pi+pi-pi+ has
been performed. The analysis uses a 384 fb-1 data sample recorded by the BaBar
detector at the PEP-II asymmetric-energy e+e- storage ring running at center of
mass energies near 10.6 GeV. Amplitudes and phases of the intermediate
resonances which contribute to this final state are measured. A high precision
measurement of the ratio of branching fractions is performed: BR(Ds+ ->
pi+pi-pi+)/BR(Ds+ -> K+ K- pi+)=0.199 +/- 0.004 +/- 0.009. Using a
model-independent partial wave analysis, the amplitude and phase of the S-wave
have been measured.


title: Some news about generalised parton distributions

abstract:
  I briefly discuss some recent developments (and recall some old news) in the
theory and phenomenology of generalised parton distributions.


title: Text Modeling using Unsupervised Topic Models and Concept Hierarchies

abstract:
  Statistical topic models provide a general data-driven framework for
automated discovery of high-level knowledge from large collections of text
documents. While topic models can potentially discover a broad range of themes
in a data set, the interpretability of the learned topics is not always ideal.
Human-defined concepts, on the other hand, tend to be semantically richer due
to careful selection of words to define concepts but they tend not to cover the
themes in a data set exhaustively. In this paper, we propose a probabilistic
framework to combine a hierarchy of human-defined semantic concepts with
statistical topic models to seek the best of both worlds. Experimental results
using two different sources of concept hierarchies and two collections of text
documents indicate that this combination leads to systematic improvements in
the quality of the associated language models as well as enabling new
techniques for inferring and visualizing the semantics of a document.


title: Superconductivity of Mo3Sb7 from first principles

abstract:
  Superconductivity in Mo3Sb7 is analyzed using the combined electronic
structure and phonon calculations, and the electron--phonon coupling constant
\lambda_{ph}=0.54 is determined from first principles. This value explains the
experimental value of the superconducting critical temperature T_c=2.2 K. The
possible influence of spin fluctuations and spin gap on the superconductivity
in Mo3Sb7 is discussed, and electron--paramagnon interaction is found to be
weak.


title:
Magnetocaloric properties of Fe_{2-x}T_xP (T = Ru and Rh) from
  electronic structure calculations and magnetisation measurements

abstract:
  An analysis of the magnetocaloric properties of the pure and substituted Fe2P
compounds is made based on KKR-CPA electronic structure calculations and
magnetisation M(H,T) measurements. The computed electronic densities of states
and magnetic moments are used to calculate both the values of the electronic
and magnetic entropies, which fairly agree with the experimental findings. To
enlighten the magnetic properties above Curie temperature, the paramagnetic
state behaviours are simulated using the disordered local moments (DLM)
concept. The KKR-CPA computations show, that in Fe2P, the Fe magnetic moment of
the (3f) site disappears in the DLM state, while the moment of the (3g) site is
only little lowered, comparison made with the low temperature ferromagnetic
state.


title: Statistics of extremes by oracle estimation

abstract:
  We use the fitted Pareto law to construct an accompanying approximation of
the excess distribution function. A selection rule of the location of the
excess distribution function is proposed based on a stagewise lack-of-fit
testing procedure. Our main result is an oracle type inequality for the
Kullback--Leibler loss.


title:
Dimension reduction based on constrained canonical correlation and
  variable filtering

abstract:
  The ``curse of dimensionality'' has remained a challenge for high-dimensional
data analysis in statistics. The sliced inverse regression (SIR) and canonical
correlation (CANCOR) methods aim to reduce the dimensionality of data by
replacing the explanatory variables with a small number of composite directions
without losing much information. However, the estimated composite directions
generally involve all of the variables, making their interpretation difficult.
To simplify the direction estimates, Ni, Cook and Tsai [Biometrika 92 (2005)
242--247] proposed the shrinkage sliced inverse regression (SSIR) based on SIR.
In this paper, we propose the constrained canonical correlation ($C^3$) method
based on CANCOR, followed by a simple variable filtering method. As a result,
each composite direction consists of a subset of the variables for
interpretability as well as predictive power. The proposed method aims to
identify simple structures without sacrificing the desirable properties of the
unconstrained CANCOR estimates. The simulation studies demonstrate the
performance advantage of the proposed $C^3$ method over the SSIR method. We
also use the proposed method in two examples for illustration.


Cognitive MIMO Radio: A Competitive Optimality Design Based on Subspace
  Projections


title: Neutron spectroscopy and magnetic relaxation of the Mn$_6$ nanomagnets

abstract:
  Inelastic neutron scattering has been used to determine the microscopic
Hamiltonian describing two high-spin variants of the high-anisotropy Mn$_6$
nanomagnet. The energy spectrum of both systems is characterized by the
presence of several excited total-spin multiplets partially overlapping the
S=12 ground multiplet. This implies that the relaxation processes of these
molecules are different from those occurring in prototype giant-spin
nanomagnets. In particular, we show that both the height of the energy barrier
and resonant tunnelling processes are greatly influenced by low-lying excited
total-spin multiplets.


title: On Complexity of Minimum Leaf Out-branching Problem

abstract:
  Given a digraph $D$, the Minimum Leaf Out-Branching problem (MinLOB) is the
problem of finding in $D$ an out-branching with the minimum possible number of
leaves, i.e., vertices of out-degree 0. Gutin, Razgon and Kim (2008) proved
that MinLOB is polynomial time solvable for acyclic digraphs which are exactly
the digraphs of directed path-width (DAG-width, directed tree-width,
respectively) 0. We investigate how much one can extend this polynomiality
result. We prove that already for digraphs of directed path-width (directed
tree-width, DAG-width, respectively) 1, MinLOB is NP-hard. On the other hand,
we show that for digraphs of restricted directed tree-width (directed
path-width, DAG-width, respectively) and a fixed integer $k$, the problem of
checking whether there is an out-branching with at most $k$ leaves is
polynomial time solvable.


title: "Equilibrium" states of non equilibrium system

abstract:
  A possible approach to description of the non equilibrium system has been
proposed. Based on the Fokker-Plank equation in term of energy for non
equilibrium distribution function of macroscopical system was obtained the
stationary solution which can be interpreted as the equilibrium distribution
function for new energetic state. The proposed approach takes into account the
possible motion between different states of system, induced by dissipation of
energy and influence of environment which dependence on energy of the system. A
non-linear model, which describe possible stationary state of system with
different processes in it, has been described.


title:
$q$-Discrete Painlev\'e equations for recurrence coefficients of
  modified $q$-Freud orthogonal polynomials

abstract:
  We present an asymmetric $q$-Painlev\'e equation. We will derive this using
$q$-orthogonal polynomials with respect to generalized Freud weights: their
recurrence coefficients will obey this $q$-Painlev\'e equation (up to a simple
transformation). We will show a stable method of computing a special solution
which gives the recurrence coefficients. We establish a connection with
$\alpha-q-P_V$.


title:
Density of states near a vortex core in ferromagnetic superconductors:
  Application to STM measurements

abstract:
  We investigate numerically the local density of states (LDOS) in the vicinity
of a vortex core in a ferromagnetic superconductor. Specifically, we
investigate how the LDOS is affected by the relative weight of the spin bands
in terms of the superconducting pairing, and we also examine the effect of
different pairing symmetries for the superconducting order parameter. Our
findings are directly related to scanning tunneling microscopy measurements and
may thus be highly useful to clarify details of the superconducting pairing in
recently discovered ferromagnetic superconductors.


title: Fidelity induced distance measures for quantum states

abstract:
  Fidelity plays an important role in quantum information theory. In this
letter, we introduce new metric of quantum states induced by fidelity, and
connect it with the well-known trace metric, Sine metric and Bures metric for
the qubit case. The metric character is also presented for the qudit (i.e.,
$d$-dimensional system) case. The CPT contractive property and joint convex
property of the metric are also studied.


title: Fence methods for mixed model selection

abstract:
  Many model search strategies involve trading off model fit with model
complexity in a penalized goodness of fit measure. Asymptotic properties for
these types of procedures in settings like linear regression and ARMA time
series have been studied, but these do not naturally extend to nonstandard
situations such as mixed effects models, where simple definition of the sample
size is not meaningful. This paper introduces a new class of strategies, known
as fence methods, for mixed model selection, which includes linear and
generalized linear mixed models. The idea involves a procedure to isolate a
subgroup of what are known as correct models (of which the optimal model is a
member). This is accomplished by constructing a statistical fence, or barrier,
to carefully eliminate incorrect models. Once the fence is constructed, the
optimal model is selected from among those within the fence according to a
criterion which can be made flexible. In addition, we propose two variations of
the fence. The first is a stepwise procedure to handle situations of many
predictors; the second is an adaptive approach for choosing a tuning constant.
We give sufficient conditions for consistency of fence and its variations, a
desirable property for a good model selection procedure. The methods are
illustrated through simulation studies and real data analysis.


title:
Clump morphology and evolution in MHD simulations of molecular cloud
  formation

abstract:
  Abridged: We study the properties of clumps formed in three-dimensional
weakly magnetized magneto-hydrodynamic simulations of converging flows in the
thermally bistable, warm neutral medium (WNM). We find that: (1) Similarly to
the situation in the classical two-phase medium, cold, dense clumps form
through dynamically-triggered thermal instability in the compressed layer
between the convergent flows, and are often characterised by a sharp density
jump at their boundaries though not always. (2) However, the clumps are bounded
by phase-transition fronts rather than by contact discontinuities, and thus
they grow in size and mass mainly by accretion of WNM material through their
boundaries. (3) The clump boundaries generally consist of thin layers of
thermally unstable gas, but these layers are often widened by the turbulence,
and penetrate deep into the clumps. (4) The clumps are approximately in both
ram and thermal pressure balance with their surroundings, a condition which
causes their internal Mach numbers to be comparable to the bulk Mach number of
the colliding WNM flows. (5) The clumps typically have mean temperatures 20 < T
< 50 K, corresponding to the wide range of densities they contain (20 < n <
5000 pcc) under a nearly-isothermal equation of state. (6) The turbulent ram
pressure fluctuations of the WNM induce density fluctuations that then serve as
seeds for local gravitational collapse within the clumps. (7) The velocity and
magnetic fields tend to be aligned with each other within the clumps, although
both are significantly fluctuating, suggesting that the velocity tends to
stretch and align the magnetic field with it. (8) The typical mean field
strength in the clumps is a few times larger than that in the WNM. (9) The
magnetic field strength has a mean value of B ~ 6 mu G ...


title:
A new graph perspective on max-min fairness in Gaussian parallel
  channels

abstract:
  In this work we are concerned with the problem of achieving max-min fairness
in Gaussian parallel channels with respect to a general performance function,
including channel capacity or decoding reliability as special cases. As our
central results, we characterize the laws which determine the value of the
achievable max-min fair performance as a function of channel sharing policy and
power allocation (to channels and users). In particular, we show that the
max-min fair performance behaves as a specialized version of the Lovasz
function, or Delsarte bound, of a certain graph induced by channel sharing
combinatorics. We also prove that, in addition to such graph, merely a certain
2-norm distance dependent on the allowable power allocations and used
performance functions, is sufficient for the characterization of max-min fair
performance up to some candidate interval. Our results show also a specific
role played by odd cycles in the graph induced by the channel sharing policy
and we present an interesting relation between max-min fairness in parallel
channels and optimal throughput in an associated interference channel.


title: Derived Kodaira Spencer map, Cosection lemma, and semiregularity

abstract:
  The cosection lemma proved by J. Li and Y.H. Kiem said the intrinsic normal
cone lies inside the kernel of any cosection of the obstruction sheaf when the
moduli has a perfect obstruction theory. With a definition of higher tangent
vectors of a scheme at a point, and a construction of the derived Kodaira
Spencer map by K. Behrend and B. Fantechi, we prove a derived version of
cosection lemma without perfect obstruction theory condition. As an application
we give a short proof of the Kodaira's Principle \textit{ambient cohomology
annihilates obstruction} (semiregularity), assuming the existence of locall
universal family.


title: Semiparametric detection of significant activation for brain fMRI

abstract:
  Functional magnetic resonance imaging (fMRI) aims to locate activated regions
in human brains when specific tasks are performed. The conventional tool for
analyzing fMRI data applies some variant of the linear model, which is
restrictive in modeling assumptions. To yield more accurate prediction of the
time-course behavior of neuronal responses, the semiparametric inference for
the underlying hemodynamic response function is developed to identify
significantly activated voxels. Under mild regularity conditions, we
demonstrate that a class of the proposed semiparametric test statistics, based
on the local linear estimation technique, follow $\chi^2$ distributions under
null hypotheses for a number of useful hypotheses. Furthermore, the asymptotic
power functions of the constructed tests are derived under the fixed and
contiguous alternatives. Simulation evaluations and real fMRI data application
suggest that the semiparametric inference procedure provides more efficient
detection of activated brain areas than the popular imaging analysis tools AFNI
and FSL.


title: Effective Scenario of Loop Quantum Cosmology

abstract:
  Semiclassical states in isotropic loop quantum cosmology are employed to show
that the improved dynamics has the correct classical limit. The effective
Hamiltonian for the quantum cosmological model with a massless scalar field is
thus obtained, which incorporates also the next to leading order quantum
corrections. The possibility that the higher order correction terms may lead to
significant departure from the leading order effective scenario is revealed. If
the semiclassicality of the model is maintained in the large scale limit, there
are great possibilities for $k=0$ Friedmann expanding universe to undergo a
collapse in the future due to the quantum gravity effect. Thus the quantum
bounce and collapse may contribute a cyclic universe in the new scenario.


title:
Ferro-electric phase transition in a polar liquid and the nature of
  \lambda-transition in supercooled water

abstract:
  We develop a series of approximations to calculate free energy of a polar
liquid. We show that long range nature of dipole interactions between the
molecules leads to para-electric state instability at low temperatures and to a
second-order phase transition. We establish the transition temperature, T_{c},
both within mean field and ring diagrams approximation and show that the
ferro-electric transition may play an important role explaining a number of
peculiar properties of supercooled water, such as weak singularity of
dielectric constant as well as to a large extent anomalous density behavior.
Finally we discuss the role of fluctuations, shorter range forces and establish
connections with phenomenological models of polar liquids.


title: On the string coupling in a class of stringy orbifold GUTs

abstract:
  In this short note, we examine the relationship between the string coupling
constant, $\gstring{}$, and the grand unified gauge coupling constant,
$\alphagut{}$, in a highly successful class of models based on anisotropic
orbifold compactifications of the weakly coupled heterotic string. These models
represent a stringy embedding of SU(6) gauge-Higgs unification in a five
dimensional orbifold GUT. We find that the requirement that the theory be
perturbative provides a non-trivial constraint on these models. Interestingly,
there is a correlation between the proton decay rate (due to dimension six
operators) and the string coupling constant. Finally, we make some comments
concerning the extension of these models to the six (and higher) dimensional
case.


title: Indications of Universal Excess Fluctuations in Nonequilibrium Systems

abstract:
  The fluctuation in electric current in nonequilibrium steady states is
investigated by molecular dynamics simulation of macroscopically uniform
conductors. At low frequencies, appropriate decomposition of the spectral
intensity of current into thermal and excess fluctuations provides a simple
picture of excess fluctuations behaving as shot noise. This indicates that the
fluctuation-dissipation relation may be violated in a universal manner by the
appearance of shot noise for a wide range of systems with particle or momentum
transport.


title:
Scaling properties of critical bubble of homogeneous nucleation in
  stretched fluid of square-gradient density-functional model with
  triple-parabolic free energy

abstract:
  The square-gradient density-functional model with triple-parabolic free
energy is used to study homogeneous bubble nucleation in a stretched liquid to
check the scaling rule for the work of formation of the critical bubble as a
function of scaled undersaturation $\Delta\mu/\Delta\mu_{\rm spin}$, the
difference in chemical potential $\Delta\mu$ between the bulk undersaturated
and saturated liquid divided by $\Delta\mu_{\rm spin}$ between the liquid
spinodal and saturated liquid. In contrast to our study, a similar
density-functional study for a Lennard-Jones liquid by Shen and Debenedetti [J.
Chem. Phys. {\bf 114}, 4149 (2001)] found that not only the work of formation
but other various quantities related to the critical bubble show the scaling
rule, however, we found virtually no scaling relationships in our model near
the coexistence. Although some quantities show almost perfect scaling relations
near the spinodal, the work of formation divided by the value deduced from the
classical nucleation theory shows no scaling in this model even though it
correctly vanishes at the spinodal. Furthermore, the critical bubble does not
show any anomaly near the spinodal as predicted many years ago. In particular,
our model does not show diverging interfacial width at the spinodal, which is
due to the fact that compressibility remains finite until the spinodal is
reached in our parabolic models.


title: Normal Forms for Semilinear Quantum Harmonic Oscillators

abstract:
  We consider the semilinear harmonic oscillator $$i\psi_t=(-\Delta +\va{x}^{2}
+M)\psi +\partial_2 g(\psi,\bar \psi), \quad x\in \R^d, t\in \R$$ where $M$ is
a Hermite multiplier and $g$ a smooth function globally of order 3 at least. We
prove that such a Hamiltonian equation admits, in a neighborhood of the origin,
a Birkhoff normal form at any order and that, under generic conditions on $M$
related to the non resonance of the linear part, this normal form is integrable
when $d=1$ and gives rise to simple (in particular bounded) dynamics when
$d\geq 2$. As a consequence we prove the almost global existence for solutions
of the above equation with small Cauchy data. Furthermore we control the high
Sobolev norms of these solutions.


title: Interplay between 3d and 4f magnetism in CeCoPO

abstract:
  The ground state properties of CeCoPO, a homologue of the new high
temperature superconductors RFePnO1-xFx, were studied by means of
susceptibility, specific heat, and resistivity measurements on polycrystals.
The observation of a well defined Curie-Weiss behavior above 230K with
mu_eff=2.9mu_B and a ferromagnetic ordering below T_C=75K is similar to what
was observed in LaCoPO and points to magnetism of the Co-3d electrons. However,
the Ce-ions are on the border to magnetism with a Kondo scale of T_K~40K and
show an enhanced Sommerfeld-coefficient of \gamma~200mJ/molK^2.


title: The gravitational field of a light wave

abstract:
  According to the classical Einstein-Maxwell theory of gravity and
electromagnetism, a light-wave traveling in empty space-time is accompanied by
a gravitational field of the pp-type. Therefore point masses are scattered by a
light wave, even if they carry no electric or magnetic charge, or dipole
moment. In this paper I present the explicit form of the metric and curvature
for both circularly and linearly polarized light, and discuss the geodesic
motion of test masses. This is followed by a discussion of classical scattering
of point particles by the gravitational field associated with a circularly
polarized electromagnetic block wave. A generalization to a quantum theory of
particles in the background of these classical wave fields is presented in
terms of the covariant Klein-Gordon equation. I derive the energy spectrum of
quantum particles in the specific case of the circularly polarized block wave.
Finally, a few general remarks on the extension to a quantum light wave are
presented.


title: Supersolid behavior of nonlinear light

abstract:
  We present a formal demonstration that light can simultaneously exhibit a
superfluid behavior and spatial long-range order when propagating in a photonic
crystal with self-focussing nonlinearity. In this way, light presents the
distinguishing features of matter in a "supersolid" phase. We show that this
supersolid phase provides the stability conditions for nonlinear Bloch waves
and, at the same time, permits the existence of topological solitons or defects
for the envelope of these waves. We use a condensed matter analysis instead of
a standard nonlinear optics approach and provide numerical evidence of these
theoretical findings.


title: On finite groups acting on acyclic low-dimensional manifolds

abstract:
  We consider finite groups which admit a faithful, smooth action on an acyclic
manifold of dimension three, four or five (e.g. euclidean space). Our first
main result states that a finite group acting on an acyclic 3- or 4-manifold is
isomorphic to a subgroup of the orthogonal group O(3) or O(4), respectively.
The analogue remains open in dimension five (where it is not true for arbitrary
continuous actions, however). We prove that the only finite nonabelian simple
groups admitting a smooth action on an acyclic 5-manifold are the alternating
groups A_5 and A_6, and deduce from this a short list of finite groups, closely
related to the finite subgroups of SO(5), which are the candidates for
orientation-preserving actions on acyclic 5-manifolds.


title:
Fitness Landscape Analysis for Dynamic Resource Allocation in Multiuser
  OFDM Based Cognitive Radio Systems

abstract: This paper has been withdrawn.


title:
Happy places or happy people? A multi-level modelling approach to the
  analysis of happiness and well-being

abstract:
  This paper aims to enhance our understanding of substantive questions
regarding self-reported happiness and well-being through the specification and
use of multi-level models. To date, there have been numerous quantitative
research studies of the happiness of individuals, based on single-level
regression models, where typically a happiness index is related to a set of
explanatory variables. There are also several single-level studies comparing
aggregate happiness levels between countries. Nevertheless, there have been
very few studies that attempt to simultaneously take into account variations in
happiness and well-being at several different levels, such as individual,
household, and area. Here, multilevel models are used with data from the
British Household Panel Survey to assess the nature and extent of variations in
happiness and well-being to determine the relative importance of the area
(district, region), household and individual characteristics on these outcomes.
Moreover, having taken into account the characteristics at these different
levels in the multilevel models, the paper shows how it is possible to identify
any areas that are associated with especially positive or negative feelings of
happiness and well-being.


title:
Solutions of Dirac Equation for Symmetric Generalized Woods-Saxon
  Potential by the Hypergeometric Method

abstract:
  The Dirac equation is solved approximately for the Hulthen potential with the
pseudospin symmetry for any spin-orbit quantum number $\kappa$ in the
position-dependent mass background. Solutions are obtained reducing the Dirac
equation into a Schr\"{o}dinger-like differential equation by using an
appropriate coordinate transformation. The Nikiforov-Uvarov method is used in
the calculations to get energy eigenvalues and the corresponding wave
functions.


title:
Study of Charm Fragmentation into D^{*\pm} Mesons in Deep-Inelastic
  Scattering at HERA

abstract:
  The process of charm quark fragmentation is studied using $D^{*\pm}$ meson
production in deep-inelastic scattering as measured by the H1 detector at HERA.
Two different regions of phase space are investigated defined by the presence
or absence of a jet containing the $D^{*\pm}$ meson in the event. The
parameters of fragmentation functions are extracted for QCD models based on
leading order matrix elements and DGLAP or CCFM evolution of partons together
with string fragmentation and particle decays. Additionally, they are
determined for a next-to-leading order QCD calculation in the fixed flavour
number scheme using the independent fragmentation of charm quarks to $D^{*\pm}$
mesons.


title: Left-right asymmetry in semi-inclusive deep inelastic scattering process

abstract:
  We analyze the left-right asymmetry of pion production in semi-inclusive deep
inelastic scattering (SIDIS) process of unpolarized charged lepton on
transversely polarized nucleon target. Unlike available treatments, in which
some specific weighting functions are multiplied to separate theoretically
motivated quantities, we do not introduce any weighting function following the
analyzing method by the E704 experiment. The advantage is that this basic
observable is free of any theoretical bias, although we can perform the
calculation under the current theoretical framework. We present numerical
calculations at both HERMES kinematics for the proton target and JLab
kinematics for the neutron target. We find that with the current theoretical
understanding, Sivers effect plays a key role in our analysis.


title:
Theory of time-resolved optical spectroscopy on correlated electron
  systems

abstract:
  The real-time dynamics of interacting electrons out of equilibrium contains
detailed microscopic information about electronically correlated materials,
which can be read out with time-resolved optical spectroscopy. The reflectivity
that is typically measured in pump-probe experiments is related to the
nonequilibrium optical conductivity. We show how to express this quantity in
terms of real-time Green functions using dynamical mean-field theory. As an
application we study the electrical response of the Falicov-Kimball model
during the ultrafast buildup of the gapped phase at large interaction.


title: Infinite potential well with a sinusoidal bottom

abstract:
  We construct a tridiagonal matrix representation of the wave operator that
maps the wave equation into a three-term recursion relation for the expansion
coefficients of the wavefunction. Finding a solution of the recursion relation
is equivalent to solving the original problem. Consequently, a larger class of
solvable potentials is obtained. The usual diagonal representation constraint
results in a reduction to the conventional class of solvable potentials. To
exhibit the power of this approach, we give an exact solution for the infinite
potential well with sinusoidal bottom.


title: On Quantum Capacity of Compound Channels

abstract:
  In this paper we address the issue of universal or robust communication over
quantum channels. Specifically, we consider memoryless communication scenario
with channel uncertainty which is an analog of compound channel in classical
information theory. We determine the quantum capacity of finite compound
channels and arbitrary compound channels with informed decoder. Our approach in
the finite case is based on the observation that perfect channel knowledge at
the decoder does not increase the capacity of finite quantum compound channels.
As a consequence we obtain coding theorem for finite quantum averaged channels,
the simplest class of channels with long-term memory. The extension of these
results to quantum compound channels with uninformed encoder and decoder, and
infinitely many constituents remains an open problem.


title:
Symmetry Classes in Graphene Quantum Dots: Universal Spectral
  Statistics, Weak Localization, and Conductance Fluctuations

abstract:
  We study the symmetry classes of graphene quantum dots, both open and closed,
through the conductance and energy level statistics. For abrupt termination of
the lattice, these properties are well described by the standard orthogonal and
unitary ensembles. However, for smooth mass confinement, special time-reversal
symmetries associated with the sublattice and valley degrees of freedom are
critical: they lead to block diagonal Hamiltonians and scattering matrices with
blocks belonging to the unitary symmetry class even at zero magnetic field.
While the effect of this structure is clearly seen in the conductance of open
dots, it is suppressed in the spectral statistics of closed dots, because the
intervalley scattering time is shorter than the time required to resolve a
level spacing in the closed systems but longer than the escape time of the open
systems.


title:
Incommensurate spin density modulation in a copper-oxide chain compound
  with commensurate charge order

abstract:
  Neutron diffraction has been used to determine the magnetic structure of
Na$_8$Cu$_5$O$_{10}$, a stoichiometric compound containing chains based on
edge-sharing CuO$_4$ plaquettes. The chains are doped with 2/5 hole per Cu site
and exhibit long-range commensurate charge order with an onset well above room
temperature. Below $T_N = 23$ K, the neutron data indicate long-range collinear
magnetic order with a spin density modulation whose propagation vector is
commensurate along and incommensurate perpendicular to the chains. Competing
interchain exchange interactions are discussed as a possible origin of the
incommensurate magnetic order.


title: Confidence bands in nonparametric time series regression

abstract:
  We consider nonparametric estimation of mean regression and conditional
variance (or volatility) functions in nonlinear stochastic regression models.
Simultaneous confidence bands are constructed and the coverage probabilities
are shown to be asymptotically correct. The imposed dependence structure allows
applications in many linear and nonlinear auto-regressive processes. The
results are applied to the S&P 500 Index data.


title: Hadronic B Decays at BABAR and BELLE

abstract:
  We review recent results of the BABAR and BELLE Collaborations on the the
alpha and gamma angles of the unitary triangle, on the B to K pi pi Dalitz-plot
analyses, and on the searches for baryonic B decays and for B to DD decays.


title: One-step sparse estimates in nonconcave penalized likelihood models

abstract:
  Fan and Li propose a family of variable selection methods via penalized
likelihood using concave penalty functions. The nonconcave penalized likelihood
estimators enjoy the oracle properties, but maximizing the penalized likelihood
function is computationally challenging, because the objective function is
nondifferentiable and nonconcave. In this article, we propose a new unified
algorithm based on the local linear approximation (LLA) for maximizing the
penalized likelihood for a broad class of concave penalty functions.
Convergence and other theoretical properties of the LLA algorithm are
established. A distinguished feature of the LLA algorithm is that at each LLA
step, the LLA estimator can naturally adopt a sparse representation. Thus, we
suggest using the one-step LLA estimator from the LLA algorithm as the final
estimates. Statistically, we show that if the regularization parameter is
appropriately chosen, the one-step LLA estimates enjoy the oracle properties
with good initial estimators. Computationally, the one-step LLA estimation
methods dramatically reduce the computational cost in maximizing the nonconcave
penalized likelihood. We conduct some Monte Carlo simulation to assess the
finite sample performance of the one-step sparse estimation methods. The
results are very encouraging.


title:
Discussion: One-step sparse estimates in nonconcave penalized likelihood
  models

abstract:
  Discussion of ``One-step sparse estimates in nonconcave penalized likelihood
models'' [arXiv:0808.1012]


title:
What is measured in a photoluminescence experiment on Quantum dots
  embedded in a large Purcell factor microcavity?

abstract:
  It is usually assumed that when performing a photoluminescence experiment on
a microcavity containing an inhomogeneously broadened quantum dots ensemble,
the cavity mode appears as a positive peak with a linewidth that reflects the
mode quality factor Q. We show in this article that this conclusion is in
general not true, and that the measured mode linewidth depends strongly on the
excitation power for microcavities having large Purcell factors. We analyze
theoretically this effect in the case of the micropillar cavity and we show
that the same microcavity can give rise to a large variety of photoluminescence
spectral signatures depending on the excitation power and collection set-up. We
finally give guidelines to measure the real cavity quality factor by
photoluminescence.


title: QED$_{4}$ Ward Identity for fermionic field in the light-front

abstract:
  In a covariant gauge we implicitly assume that the Green's function
propagates information from one point of the space-time to another, so that the
Green's function is responsible for the dynamics of the relativistic particle.
In the light front form, which in principle is a change of coordinates, one
would expect that this feature would be preserved. In this manner, the
fermion's field propagator can be split into a propagating piece and a
non-propagating (``contact'') term. Since the latter (``contact'') one does not
propagate information, and therefore, assumedly with no harm to the field
dynamics we wanted to know what would be the impact of dropping it off. To do
that, we investigated its role in the Ward identity in the light front.


title:
Discussion: One-step sparse estimates in nonconcave penalized likelihood
  models: Who cares if it is a white cat or a black Cat?


title: Efficient use of the Generalized Eigenvalue Problem

abstract:
  We analyze the systematic errors made when using the generalized eigenvalue
problem to extract energies and matrix elements in lattice gauge theory.
Effective theories such as HQET are also discussed. Numerical results are shown
for the extraction of ground-state and excited B-meson masses and the
ground-state decay constant in the static approximation.


title: Universality in the Energy Spectrum of Medium-Sized Quantum Dots

abstract:
  In a two-dimensional parabolic quantum dot charged with $N$ electrons,
Thomas-Fermi theory states that the ground-state energy satisfies the following
non-trivial relation: $E_{gs}/(\hbar\omega)\approx N^{3/2}
f_{gs}(N^{1/4}\beta)$, where the coupling constant, $\beta$, is the ratio
between Coulomb and oscillator ($\hbar\omega$) characteristic energies, and
$f_{gs}$ is a universal function. We perform extensive Configuration
Interaction calculations in order to verify that the exact energies of
relatively large quantum dots approximately satisfy the above relation. In
addition, we show that the number of energy levels for intraband and interband
(excitonic and biexcitonic) excitations of the dot follows a simple exponential
dependence on the excitation energy, whose exponent, $1/\Theta$, satisfies also
an approximate scaling relation {\it a la} Thomas-Fermi,
$\Theta/(\hbar\omega)\approx N^{-\gamma} g(N^{1/4}\beta)$. We provide an
analytic expression for $f_{gs}$, based on two-point Pad\'e approximants, and
two-parameter fits for the $g$ functions.


title:
Quantum SUSY Algebra of $Q$-lumps in the Massive Grassmannian Sigma
  Model

abstract:
  We compute the $\mathcal{N}=2$ SUSY algebra of the massive Grassmannian sigma
model in 2+1 dimensions. We first rederive the action of the model by using the
Scherk-Schwarz dimensional reduction from $\mathcal{N}=1$ theory in 3+1
dimensions. Then, we perform the canonical quantization by using the Dirac
method. We find that a particular choice of the operator ordering yields the
quantum SUSY algebra of the $Q$-lumps with cental extension.


title: Photonic Time Stretch Enhanced Recording Scope

abstract:
  We demonstrate a new mode of operation for the Time Stretched A/D converter.
The technique is superior to the sampling scope in that it permits the capture
of non periodic events such as clustered noise.


title: Autoregressive description of biological phenomena

abstract:
  Many natural phenomena can be described by power-laws. A closer look at
various experimental data reveals more or less significant deviations from a
1/f spectrum. We exemplify such cases with phenomena offered by molecular
biology, cell biophysics, and cognitive psychology. Some of these cases can be
described by first order autoregressive (AR) models or by higher order AR
models which are short range correlation models. The calculations are checked
against astrophysical data which were fitted to a an AR model by a different
method. We found that our fitting method of the data give similar results for
the astrhophysical data and therefore applied the method for examples mentioned
above. Our results show that such phenomena can be described by first or higher
order of AR models. Therefore such examples are described by short range
correlation properties while they can be easily confounded with long range
correlation phenomena.


title: High-energy hadron-hadron (dipole-dipole) scattering from lattice QCD

abstract:
  In this paper the problem of high-energy hadron-hadron (dipole-dipole)
scattering is approached (for the first time) from the point of view of lattice
QCD, by means of Monte Carlo numerical simulations. In the first part, we give
a brief review of how high-energy scattering amplitudes can be reconstructed,
using a functional-integral approach, in terms of certain correlation functions
of two Wilson loops and we also briefly recall some relevant analyticity and
crossing-symmetry properties of these loop-loop correlation functions, when
going from Euclidean to Minkowskian theory. In the second part, we shall see
how these (Euclidean) loop-loop correlation functions can be evaluated in
lattice QCD and we shall compare our numerical results with some
nonperturbative analytical estimates that appeared in the literature,
discussing in particular the question of the analytic continuation from
Euclidean to Minkowskian theory and its relation to the still unsolved problem
of the asymptotic s-dependence of the hadron-hadron total cross sections.


title: Categorical quantum mechanics

abstract:
  This invited chapter in the Handbook of Quantum Logic and Quantum Structures
consists of two parts: 1. A substantially updated version of quant-ph/0402130
by the same authors, which initiated the area of categorical quantum mechanics,
but had not yet been published in full length; 2. An overview of the progress
which has been made since then in this area.


title:
Tetragonal to orthorhombic phase transition in SmFeAsO: a synchrotron
  powder diffraction investigation

abstract:
  The crystal structure of SmFeAsO has been investigated by means of Rietveld
refinement of high resolution synchrotron powder diffraction data collected at
300 K and 100 K. The compound crystallizes in the tetragonal P4/nmm space group
at 300 K and in the orthorhombic Cmma space group at 100 K; attempts to refine
the low temperature data in the monoclinic P112/n space group diverged. On the
basis of both resistive and magnetic analyses the tetragonal to orthorhombic
phase transition can be located at T about 140 K.


title: Some General Theorems of Incremental Thermoelectroelasticity

abstract:
  We extend to incremental thermoelectroelasticity with biasing fields certain
classical theorems, that have been stated and proved in linear
thermopiezoelectricity referred to a natural configuration. A uniqueness
theorem for the solutions to the initial boundary value problem, the
generalized Hamilton principle and a theorem of reciprocity of work are deduced
for incremental fields superposed on finite biasing fields in a
thermoelectroelastic body.


title: Exclusive Upsilon-photoproduction: from HERA to Tevatron

abstract:
  The amplitude for photoproduction gamma p -> \Upsilon p is calculated in a
pQCD k_\perp-factorization approach. The total cross section for diffractive
\Upsilon's is compared to recent HERA data. The amplitude is used to predict
the cross section for exclusive ppbar \to ppbar \Upsilon(1S,2S) process in
hadronic reactions at Tevatron energies. We also included absorption effects.


title: Energy Gaps and Kohn Anomalies in Elemental Superconductors

abstract:
  The momentum and temperature dependence of the lifetimes of acoustic phonons
in the elemental superconductors Pb and Nb was determined by resonant spin-echo
spectroscopy with neutrons. In both elements, the superconducting energy gap
extracted from these measurements was found to converge with sharp anomalies
originating from Fermi-surface nesting (Kohn anomalies) at low temperatures.
The results indicate electron many-body correlations beyond the standard
theoretical framework for conventional superconductivity. A possible mechanism
is the interplay between superconductivity and spin- or charge-density-wave
fluctuations, which may induce dynamical nesting of the Fermi surface.


title: Bases in diagrammatic quantum protocols

abstract:
  This paper contains two new results:
  1. We amend the notion of abstract basis in a dagger symmetric monoidal
category, as well as its corresponding graphical representation, in order to
accommodate non-self-dual dagger compact structures; this is crucial for
obtaining a `planar' diagrammatical representation of the induced dagger
compact structure as well as for representing many complementary bases within
one diagrammatic calculus.
  2. We (crucially) rely on these basis structures in a purely diagrammatic
derivation of the `quantum state transfer protocol'; this derivation provides
interesting insights in the distinct structural resources required for
state-transfer and teleportation as models of quantum computing.


title:
Rejoinder: One-step sparse estimates in nonconcave penalized likelihood
  models

abstract:
  We would like to take this opportunity to thank the discussants for their
thoughtful comments and encouragements on our work [arXiv:0808.1012]. The
discussants raised a number of issues from theoretical as well as computational
perspectives. Our rejoinder will try to provide some insights into these issues
and address specific questions asked by the discussants.


title: Commissioning of the ATLAS Experiment

abstract:
  The status of the commissioning of the ATLAS experiment as of May 2008 is
presented. The sub-detector integration in recent milestone weeks is described.
Cosmic commissioning in milestone week M6 included simultaneous data-taking and
combined track analysis of the muon detector and inner detector, as well as
combined analysis of muon detector and muon trigger. The calorimeters have
achieved near-full operation, and are integrated with the calorimeter trigger.
The high-level-trigger infrastructure is being installed and algorithms tested
in technical runs.


title: Introducing categories to the practicing physicist

abstract:
  We argue that category theory should become a part of the daily practice of
the physicist, and more specific, the quantum physicist and/or informatician.
The reason for this is not that category theory is a better way of doing
mathematics, but that monoidal categories constitute the actual algebra of
practicing physics. We will not provide rigorous definitions or anything
resembling a coherent mathematical theory, but we will take the reader for a
journey introducing concepts which are part of category theory in a manner that
the physicist will recognize them.

categories: quant-ph math-ph math.CT math.LO math.MP


title: NGC 602 Environment, Kinematics and Origins

abstract:
  The young star cluster NGC 602 and its associated HII region, N90, formed in
a relatively isolated and diffuse environment in the Wing of the Small
Magellanic Cloud. Its isolation from other regions of massive star formation
and the relatively simple surrounding HI shell structure allows us to constrain
the processes that may have led to its formation and to study conditions
leading to massive star formation. We use images from Hubble Space Telescope
and high resolution echelle spectrographic data from the Anglo-Australian
Telescope along with 21-cm neutral hydrogen (HI) spectrum survey data and the
shell catalogue derived from it to establish a likely evolutionary scenario
leading to the formation of NGC 602. We identify a distinct HI cloud component
that is likely the progenitor cloud of the cluster and HII region which
probably formed in blister fashion from the cloud's periphery. We also find
that the past interaction of HI shells can explain the current location and
radial velocity of the nebula. The surrounding Interstellar Medium is diffuse
and dust-poor as demonstrated by a low visual optical depth throughout the
nebula and an average HI density of the progenitor cloud estimated at 1 cm^-3.
These conditions suggest that the NGC 602 star formation event was produced by
compression and turbulence associated with HI shell interactions. It therefore
represents a single star forming event in a low gas density region.


title:
Exclusive $eta_b$ decay to double $J/\psi$ at next-to-leading order in
  $alpha_s$

abstract:
  Within the nonrelativistic QCD (NRQCD) factorization framework, we calculate
the exclusive decay process \eta_b \to J/\psi J/\psi to next-to-leading order
in the strong coupling constant, while at leading order in charm quark relative
velocity. It is found that this new contribution to the amplitude is comparable
in magnitude with the previously calculated relativistic correction piece, but
differs by a phase about 90^\circ. Including this new contribution will
increase the previous prediction to B(\eta_b \to J/\psi J/\psi) substantially,
thus brightening the discovery potential of this clean hadronic decay channel
of \eta_b in the forthcoming LHC experiment.


title: Global One-Dimensionality conjecture within Quantum General Relativity

abstract:
  The simple quantum gravity model, based on a new conjecture within the
canonically quantized 3+1 general relativity, is presented. The conjecture
states that matter fields are functionals of an embedding volume form only, and
reduces the quantum geometrodynamics. By dimensional reduction the resulting
theory is presented in the form of the Dirac equation, and application of the
Fock quantization with the diagonalization procedure yields construction of the
appropriate quantum field theory. The 1D wave function is derived, the
corresponding 3-dimensional manifolds are discussed, and physical scales are
associated with quantum correlations.


title:
On Boundary Control Problems in Slow Processes for Piezothermoelastic
  Plates

abstract:
  We consider a piezothermoelastic panel occupied by a material of hexagonal
crystal class. We study the response when the boundary conditions vary very
slowly with time and one of the bounding faces is subject to thermal exposure.
We show that in some cases the temperature on the other bounding face can be
controlled by the difference of electric potential between the faces.