title: Optics of spin-1 particles from gravity-induced phases

abstract:
  The Maxwell and Maxwell-de Rham equations can be solved exactly to first
order in an external gravitational field. The gravitational background induces
phases in the wave functions of spin-1 particles. These phases yield the optics
of the particles without requiring any thin lens approximation.


title: Recognizing Members of the Tournament Equilibrium Set is NP-hard

abstract:
  A recurring theme in the mathematical social sciences is how to select the
"most desirable" elements given a binary dominance relation on a set of
alternatives. Schwartz's tournament equilibrium set (TEQ) ranks among the most
intriguing, but also among the most enigmatic, tournament solutions that have
been proposed so far in this context. Due to its unwieldy recursive definition,
little is known about TEQ. In particular, its monotonicity remains an open
problem up to date. Yet, if TEQ were to satisfy monotonicity, it would be a
very attractive tournament solution concept refining both the Banks set and
Dutta's minimal covering set. We show that the problem of deciding whether a
given alternative is contained in TEQ is NP-hard.


title: Spectral Study of the Galactic Ridge X-ray Emission with Suzaku

abstract:
  We have observed a typical Galactic plane field at (l,b) = (28.46d, -0.20d)
with Suzaku for 100 ksec to carry out a precise spectral study of the Galactic
Ridge X-ray Emission (GRXE). The field is known to be devoid of X-ray point
sources brighter than ~2 x 10^{-13} ergs s^{-1} cm^{-2} (2--10 keV), and
already deeply observed with Chandra. Thanks to the low and stable background
and high spectral resolution of Suzaku, we were able to resolve, for the first
time, three narrow iron K-emission lines from low-ionized (6.41 keV),
helium-like (6.67 keV), and hydrogenic ions (7.00 keV) in the GRXE spectrum.
These line features constrain the GRXE emission mechanisms: The cosmic-ray ion
charge exchange model or the non-equilibrium ionization plasma model are
unlikely, since they require either broad emission lines or lines at
intermediate ionization states. Collisional ionization equilibrium plasma is
the likely origin for the 6.67 keV and 7.00 keV lines, while origin of the 6.41
keV line, which is due to fluorescence from cold material, is not elucidated.
Low non-X-ray background and little stray-light contamination of Suzaku allowed
us to precisely measure the absolute X-ray surface brightness in the direction
of the Galactic plane. Excluding the point sources brighter than ~2 x 10^{-13}
ergs s^{-1} cm^{-2} (2--10 keV), the total surface brightness on the Galactic
plane is ~6.1 x 10^{-11} ergs s^{-1} cm^{-2} deg^{-2} (2--10 keV), including
the contribution of the cosmic X-ray background that is estimated to be ~1.3x
10^{-11} ergs s^{-1} cm^{-2} deg^{-2}.


title: Renormalization Group Theory for the Imbalanced Fermi Gas

abstract:
  We formulate a wilsonian renormalization group theory for the imbalanced
Fermi gas. The theory is able to recover quantitatively well-established
results in both the weak-coupling and the strong-coupling (unitarity) limit. We
determine for the latter case the line of second-order phase transitions of the
imbalanced Fermi gas and in particular the location of the tricritical point.
We obtain good agreement with the recent experiments of Y. Shin {\it et al}.
[Nature {\bf 451}, 689 (2008)].


title: Optimal Algorithmic Cooling of Spins

abstract:
  Algorithmic Cooling (AC) of Spins is potentially the first near-future
application of quantum computing devices. Straightforward quantum algorithms
combined with novel entropy manipulations can result in a method to improve the
identification of molecules. We introduce here several new exhaustive cooling
algorithms, such as the Tribonacci and k-bonacci algorithms. In particular, we
present the ``all-bonacci'' algorithm, which appears to reach the maximal
degree of cooling obtainable by the optimal AC approach.


title:
Deformation Quantization of Surjective Submersions and Principal Fibre
  Bundles

abstract:
  In this paper we establish a notion of deformation quantization of a
surjective submersion which is specialized further to the case of a principal
fibre bundle: the functions on the total space are deformed into a right module
for the star product algebra of the functions on the base manifold. In case of
a principal fibre bundle we require in addition invariance under the principal
action. We prove existence and uniqueness of such deformations. The commutant
within all differential operators on the total space is computed and gives a
deformation of the algebra of vertical differential operators. Applications to
noncommutative gauge field theories and phase space reduction of star products
are discussed.


title: Supernova Brightening from Chameleon-Photon Mixing

abstract:
  Measurements of standard candles and measurements of standard rulers give an
inconsistent picture of the history of the universe. This discrepancy can be
explained if photon number is not conserved as computations of the luminosity
distance must be modified. I show that photon number is not conserved when
photons mix with chameleons in the presence of a magnetic field. The strong
magnetic fields in a supernova mean that the probability of a photon converting
into a chameleon in the interior of the supernova is high, this results in a
large flux of chameleons at the surface of the supernova. Chameleons and
photons also mix as a result of the intergalactic magnetic field. These two
effects combined cause the image of the supernova to be brightened resulting in
a model which fits both observations of standard candles and observations of
standard rulers.


title: Photo- and Electron-Production of Mesons on Nucleons and Nuclei

abstract:
  In these lectures I will show some results obtained with the chiral unitary
approach applied to the photo and electroproduction of mesons. The results for
photoproduction of $\eta \pi^0 p$ and $K^0 \pi^0 \Sigma^+$, together with
related reactions will be shown, having with common denominator the excitation
of the $\Delta(1700)$ resonance which is one of those dynamically generated in
the chiral unitary approach. Then I will show results obtained for the $e^+ e^-
\to \phi f_0(980)$ reaction which reproduce the bulk of the data except for a
pronounced peak, giving support to a new mesonic resonance, X(2175). Results
will also be shown for the electromagnetic form factors of the $N^*(1535)$
resonance, also dynamically generated in this approach. Finally, I will show
some results on the photoproduction of the $\omega$ in nuclei, showing that
present experimental results claiming a shift of the $\omega$ mass in the
medium are tied to a particular choice of background and are not conclusive.
One the other hand, the same experimental results show unambiguously a huge
increase of the $\omega$ width in the nuclear medium.


title:
Zero-temperature equation of state of solid 4He at low and high
  pressures

abstract:
  We study the zero-temperature equation of state (EOS) of solid 4He in the
hexagonal closed packet (hcp) phase over the 0-57 GPa pressure range by means
of the Diffusion Monte Carlo (DMC) method and the semi-empirical Aziz pair
potential HFD-B(HE). In the low pressure regime (P ~ 0-1 GPa) we assess
excellent agreement with experiments and we give an accurate description of the
atomic kinetic energy, Lindemann ratio and Debye temperature over a wide range
of molar volumes (22-6 cm^{3}/mol). However, on moving to higher pressures our
calculated P-V curve presents an increasingly steeper slope which ultimately
provides differences within ~40 % with respect to measurements. In order to
account for many-body interactions arising in the crystal with compression
which are not reproduced by our model, we perform additional electronic
density-functional theory (DFT) calculations for correcting the computed DMC
energies in a perturbative way. We explore both generalized gradient and local
density approximations (GGA and LDA, respectively) for the electronic
exchange-correlation potential. By proceeding in this manner, we show that
discrepancies with respect to high pressure data are reduced to 5-10 % with few
computational extra cost. Further comparison between our calculated EOSs and ab
initio curves deduced for the perfect crystal and corrected for the zero-point
motion of the atoms enforces the reliability of our approach.


title:
Cosmological Bang within Matter Era. Is the Generation of Galactic-Scale
  Mass Possible?

abstract:
  A heuristic hypothesis about domination of Bose-Einstein statistics in the
early Universe is suggested. The possibility of Bose-Einstein condensation
(BEC) of primordial baryon-antibaryon pairs is considered. In accordance with
this postulation enormous masses in the order of galactic mass may be
accumulated within the cosmic scales. At the certain threshold value of the
matter density the structural bosons decay into fermions and the sharp
breakdown of quantum-mechanical symmetry of the particles wave functions
occurs. Then, due to the Pauli principle of exclusion a large-scale phase
transition occurs because of enormous pressure jump of the matter. This
phenomenon might cause Cosmological Bang at the beginning stage of the Matter
Era. As a mechanism of accumulation of galactic mass much larger than the
configuration with structural bosons, a hypothetical BEC of elementary bosons
(gauge bosons $W^{\pm}$ and $Z^{0})$ is discussed as well.


title: Free holomorphic functions and interpolation

abstract:
  In this paper we obtain a noncommutative multivariable analogue of the
classical Nevanlinna-Pick interpolation problem for analytic functions with
positive real parts on the open unit disc. As consequences, we deduce some
results concerning operator-valued analytic interpolation on the unit ball on
C^n.


title:
IT services design to support coordination practices in the
  Luxembourguish AEC sector

abstract:
  In the Architecture Engineering and Construction sector (AEC) cooperation
between actors is essential for project success. The configuration of actors'
organization takes different forms like the associated coordination mechanisms.
Our approach consists in analyzing these coordination mechanisms through the
identification of the "base practices" realized by the actors of a construction
project to cooperate. We also try with practitioners to highlight the "best
practices" of cooperation. Then we suggest here two prototypes of IT services
aiming to demonstrate the value added of IT to support cooperation. These
prototype tools allow us to sensitize the actors through terrain experiments
and then to bring inch by inch the Luxembourgish AEC sector towards electronic
cooperation.


title: Wet Sand flows better than dry sand

abstract:
  We investigated the yield stress and the apparent viscosity of sand with and
without small amounts of liquid. By pushing the sand through a tube with an
enforced Poiseuille like profile we minimize the effect of avalanches and shear
localization. We find that the system starts to flow when a critical shear of
the order of one particle diameter is exceeded. In contrast to common believe,
we observe that the resistance against the flow of wet sand is much smaller
than that of dry sand. For the dissipative flow we propose a non-equilibrium
state equation for granular fluids.


title: Emergence and Computation at the Edge of Classical and Quantum Systems

abstract:
  The problem of emergence in physical theories makes necessary to build a
general theory of the relationships between the observed system and the
observing system. It can be shown that there exists a correspondence between
classical systems and computational dynamics according to the Shannon-Turing
model. A classical system is an informational closed system with respect to the
observer; this characterizes the emergent processes in classical physics as
phenomenological emergence. In quantum systems, the analysis based on the
computation theory fails. It is here shown that a quantum system is an
informational open system with respect to the observer and able to exhibit
processes of observational, radical emergence. Finally, we take into
consideration the role of computation in describing the physical world.


title: Composition with a two variable function

abstract:
  We compute the motivic nearby cycles of functions obtained by composition of
two functions with distinct sets of variables with a two variable function


title: Self-Trapping of Bosons and Fermions in Optical Lattices

abstract:
  We theoretically investigate the enhanced localization of bosonic atoms by
fermionic atoms in three-dimensional optical lattices and find a self-trapping
of the bosons for attractive boson-fermion interaction. Because of this mutual
interaction, the fermion orbitals are substantially squeezed, which results in
a strong deformation of the effective potential for bosons. This effect is
enhanced by an increasing bosonic filling factor leading to a large shift of
the transition between the superfluid and the Mott-insulator phase. We find a
nonlinear dependency of the critical potential depth on the boson-fermion
interaction strength. The results, in general, demonstrate the important role
of higher Bloch bands for the physics of attractively interacting quantum gas
mixtures in optical lattices and are of direct relevance to recent experiments
with 87Rb - 40K mixtures, where a large shift of the critical point has been
found.


title: XMM-Newton and Broad Iron Lines

abstract:
  Iron line emission is common in the X-ray spectra of accreting black holes.
When the line emission is broad or variable then it is likely to originate from
close to the black hole. X-ray irradiation of the accretion flow by the
power-law X-ray continuum produces the X-ray 'reflection' spectrum which
includes the iron line. The shape and variability of the iron lines and
reflection can be used as a diagnostic of the radius, velocity and nature of
the flow. The inner radius of the dense flow corresponds to the innermost
stable circular orbit and thus can be used to determine the spin of the black
hole. Studies of broad iron lines and reflection spectra offer much promise for
understanding how the inner parts of accretion flows (and outflows) around
black holes operate. There remains great potential for XMM-Newton to continue
to make significant progress in this work. The need for high quality spectra
and thus for long exposure times is paramount.


title: Rare D Decays

abstract:
  We discuss several recent measurements of rare charmed hadron decays. Focus
is placed on radiative and annihilation topologies highlighting their
sensitivity to new physics and pointing out the strengths and weaknesses of
different channels. We compare the different measurement techniques employed at
fixed target and $e^+e^-$ dedicated charm experiments, B-factories, and the
Tevatron experiments. Comparisons are also made to similar topologies in the
beauty, strange, and top systems where appropriate.


title: Stochastic Mechanics as a Gauge Theory

abstract:
  We show that non-relativistic Quantum Mechanics can be faithfully represented
in terms of a classical diffusion process endowed with a gauge symmetry of
group Z_4. The representation is based on a quantization condition for the
realized action along paths. A lattice regularization is introduced to make
rigorous sense of the construction and then removed. Quantum mechanics is
recovered in the continuum limit and the full U(1) gauge group symmetry of
electro-magnetism appears. Anti-particle representations emerge naturally,
albeit the context is non-relativistic. Quantum density matrices are obtained
by averaging classical probability distributions over phase-action variables.
We find that quantum conditioning can be described in classical terms but not
through the standard notion of sub sigma-algebras. Delicate restrictions arise
by the constraint that we are only interested in the algebra of gauge invariant
random variables. We conclude that Quantum Mechanics is equivalent to a theory
of gauge invariant classical stochastic processes we call Stochastic Mechanics.


title: The Local Group dwarf Leo T: HI on the brink of star formation

abstract:
  We present Giant Meterwave Radio Telescope (GMRT) and Westerbork ynthesis
Radio Telescope (WSRT) observations of the recently discovered Local Group
dwarf galaxy, Leo T. The peak HI column density is measured to be 7x10^20
cm^-2, and the total HI mass is 2.8Xx10^5 Msun, based on a distance of 420 kpc.
Leo T has both cold (~ 500 K) and warm (~ 6000 K) HI at its core, with a global
velocity dispersion of 6.9 km/s, from which we derive a dynamical mass within
the HI radius of 3.3x10^6 Msun, and a mass-to-light ratio of greater than 50.
We calculate the Jeans mass from the radial profiles of the HI column density
and velocity dispersion, and predict that the gas should be globally stable
against star formation. This finding is inconsistent with the half light radius
of Leo T, which extends to 170 pc, and indicates that local conditions must
determine where star formation takes place. Leo T is not only the lowest
luminosity galaxy with on-going star formation discovered to date, it is also
the most dark matter dominated, gas-rich dwarf in the Local Group.


title: Stochastic Integrals and Abelian Processes

abstract:
  We study triangulation schemes for the joint kernel of a diffusion process
with uniformly continuous coefficients and an adapted, non-resonant Abelian
process. The prototypical example of Abelian process to which our methods apply
is given by stochastic integrals with uniformly continuous coeffcients. The
range of applicability includes also a broader class of processes of practical
relevance, such as the sup process and certain discrete time summations we
discuss. We discretize the space coordinate in uniform steps and assume that
time is either continuous or finely discretized as in a fully explicit Euler
method and the Courant condition is satisfied. We show that the Fourier
transform of the joint kernel of a diffusion and a stochastic integral
converges in a uniform graph norm associated to the Markov generator.
Convergence also implies smoothness properties for the Fourier transform of the
joint kernel. Stochastic integrals are straightforward to define for finite
triangulations and the convergence result gives a new and entirely constructive
way of defining stochastic integrals in the continuum. The method relies on a
reinterpretation and extension of the classic theorems by Feynman-Kac,
Girsanov, Ito and Cameron-Martin, which are also re-obtained. We make use of a
path-wise analysis without relying on a probabilistic interpretation. The
Fourier representation is needed to regularize the hypo-elliptic character of
the joint process of a diffusion and an adapted stochastic integral. The
argument extends as long as the Fourier analysis framework can be generalized.
This condition leads to the notion of non-resonant Abelian process.


title: Bjorken model with Freeze Out

abstract:
  The freeze out of the expanding systems, created in relativistic heavy ion
collisions, is discussed. We combine Bjorken scenario with earlier developed
freeze out equations into a unified model. The important feature of the
proposed model is that physical freeze out is completely finished in a finite
time, which can be varied from 0 (freeze out hypersurface) to infinity. The
dependence of the post freeze out distribution function on this freeze out time
will be studied. As an example model is completely solved and analyzed for the
gas of pions.


title:
Thermodynamic inadmissibility of the incompressible hydrodynamics
  description of turbulent stratified fluid flows at low Mach numbers

abstract:
  The incompressible Navier-Stokes equations currently represent the primary
model for describing stratified turbulent fluid flows at low Mach number. The
validity of the incompressible assumption, however, has so far only been
rigorously established for adiabatic motions. Here, we show from first principl
es that the use of available energetics and thermodynamics considerations
applied to a turbulent mixing event associated with stratified shear flow
instability r efutes the widespread idea that the incompressible assumption is
also valid when diabatic irreversible effects are important. The main
consequence is that dynamics and thermodynamics are strongly coupled in
stratified turbulence. This departs strongly from the currently accepted
wisdom, and calls for a complete revisiting of the physical processes governing
stratified turbulence at low Mach numbers.


title: Dijet and photon-jet correlations in proton-proton collisions at RHIC

abstract:
  We discuss correlations in azimuthal angle as well as correlations in
two-dimensional space of transverse momenta of two jets as well as photon and
jet. Some $k_t$-factorization subprocesses are included for the first time in
the literature. Different unintegrated gluon/parton distributions are used in
the $k_t$-factorization approach. The results depend on UGDF/UPDF used. The
collinear NLO $2 \to 3$ contributions dominate over $k_t$-factorization cross
section at small relative azimuthal angles as well as for asymmetric transverse
momentum configurations.


title: Estimation of microscopic averages from metadynamics

abstract:
  With the help of metadynamics it is possible to calculate efficiently the
free energy of systems displaying high energy barriers as a function of few
selected "collective variables". In doing this, the contribution of all the
other degrees of freedom ("microscopic" variables) is averaged out and, thus,
lost. In the following, it is shown that it is possible to calculate the
thermal average of these microscopic degrees of freedom during the
metadynamics, not loosing this piece of information.


title: Conical soliton escape into a third dimension of a surface vortex

abstract:
  We present an exact three-dimensional solitonic solution to a
sine-Gordon-type Euler-Lagrange equation, that describes a configuration of a
three-dimensional vector field n constrained to a surface p-vortex, with a
prescribed polar tilt angle on a planar substrate and escaping into the third
dimension in the bulk. The solution is relevant to characterization of a
schlieren texture in nematic liquid-crystal films with tangential (in-plane)
substrate alignment. The solution is identical to a section of a point defect
discovered many years ago by Saupe [Mol. Cryst. Liq. Cryst. 21, 211 (1973)],
when latter is restricted to a surface.


title: The role of uncertainties in parton distribution functions

abstract:
  I consider the uncertainties in parton distributions and the consequences for
hadronic cross-sections. There is ever-increasing sophistication in the
relationship between the uncertainties of the distributions and the errors on
the experimental data used to extract them. However, I demonstrate that this
uncertainty is frequently subsumed by that due to the choice of data used in
fits, and more surprisingly by the precise details of the theoretical framework
used. Variations in heavy flavour prescriptions provide striking examples.


title: Almost positive curvature on the Gromoll-Meyer sphere

abstract:
  Gromoll and Meyer have represented a certain exotic 7-sphere $\Sigma^7$ as a
biquotient of the Lie group $G = Sp(2)$. We show for a 2-parameter family of
left invariant metrics on $G$ that the induced metric on $\Sigma^7$ has
strictly positive sectional curvature at all points outside four subvarieties
of codimension $\geq 1$ which we describe explicitly.


title: Neutrino Experiments: Status, Recent Progress, and Prospects

abstract:
  Neutrino physics has seen an explosion of activity and new results in the
last decade. In this report the current state of the field is summarized, with
a particular focus on progress in the last two years. Prospects for the near
term (roughly 5 years) are also described.


title: Gravitational Softening and Adaptive Mass Resolution

abstract:
  Pairwise forces between particles in cosmological N-body simulations are
generally softened to avoid hard collisions. Physically, this softening
corresponds to treating the particles as diffuse clouds rather than point
masses. For particles of unequal mass (and hence unequal softening length),
computing the softened force involves a nontrivial double integral over the
volumes of the two particles. We show that Plummer force softening is
consistent with this interpretation of softening while spline softening is not.
We provide closed-form expressions and numerical implementation for pairwise
gravitational force laws for pairs of particles of general softening scales
$\epsilon_1$ and $\epsilon_2$ assuming the commonly used cloud profiles: NGP,
CIC, TSC, and PQS. Similarly, we generalize Plummer force law into pairs of
particles of general softenings. We relate our expressions to the gaussian,
Plummer and spline force softenings known from literature. Our expressions
allow possible inclusions of pointlike particles such as stars or supermassive
black holes.


title:
Quasiperiodic Spectra and Orthogonality for Iterated Function System
  Measures

abstract:
  We extend classical basis constructions from Fourier analysis to attractors
for affine iterated function systems (IFSs). This is of interest since these
attractors have fractal features, e.g., measures with fractal scaling
dimension. Moreover, the spectrum is then typically quasi-periodic, but
non-periodic, i.e., the spectrum is a ``small perturbation'' of a lattice. Due
to earlier research on IFSs, there are known results on certain classes of
spectral duality-pairs, also called spectral pairs or spectral measures. It is
known that some duality pairs are associated with complex Hadamard matrices.
However, not all IFSs $X$ admit spectral duality. When $X$ is given, we
identify geometric conditions on $X$ for the existence of a Fourier spectrum,
serving as the second part in a spectral pair. We show how these spectral pairs
compose, and we characterize the decompositions in terms of atoms. The
decompositions refer to tensor product factorizations for associated complex
Hadamard matrices.


title:
Quantization of the open string on plane-wave limits of dS_n x S^n and
  non-commutativity outside branes

abstract:
  The open string on the plane-wave limit of $dS_n\times S^n $ with constant
  $B_2$ and dilaton background fields is canonically quantized. This entails
solving the classical equations of motion for the string, computing the
symplectic form, and defining from its inverse the canonical commutation
relations. Canonical quantization is proved to be perfectly suited for this
task, since the symplectic form is unambiguously defined and non-singular. The
string position and the string momentum operators are shown to satisfy
equal-time canonical commutation relations. Noticeably the string position
operators define non-commutative spaces for all values of the string
world-sheet parameter $\sig$, thus extending non-commutativity outside the
branes on which the string endpoints may be assumed to move. The Minkowski
spacetime limit is smooth and reproduces the results in the literature, in
particular non-commutativity gets confined to the endpoints.


title:
Gravitational solitons and $C^0$ vacuum metrics in five-dimensional
  Lovelock gravity

abstract:
  Junction conditions for vacuum solutions in five-dimensional
Einstein-Gauss-Bonnet gravity are studied. We focus on those cases where two
spherically symmetric regions of space-time are joined in such a way that the
induced stress tensor on the junction surface vanishes. So a spherical vacuum
shell, containing no matter, arises as a boundary between two regions of the
space-time. A general analysis is given of solutions that can be constructed by
this method of geometric surgery. Such solutions are a generalized kind of
spherically symmetric empty space solutions, described by metric functions of
the class $C^0$. New global structures arise with surprising features. In
particular, we show that vacuum spherically symmetric wormholes do exist in
this theory. These can be regarded as gravitational solitons, which connect two
asymptotically (Anti) de-Sitter spaces with different masses and/or different
effective cosmological constants. We prove the existence of both static and
dynamical solutions and discuss their (in)stability under perturbations that
preserve the symmetry. This leads us to discuss a new type of instability that
arises in five-dimensional Lovelock theory of gravity for certain values of the
coupling of the Gauss-Bonnet term. The issues of existence and uniqueness of
solutions and determinism in the dynamical evolution are also discussed.


title: Fragmentation processes in impact of spheres

abstract:
  We study the brittle fragmentation of spheres by using a three-dimensional
Discrete Element Model. Large scale computer simulations are performed with a
model that consists of agglomerates of many particles, interconnected by
beam-truss elements. We focus on the detailed development of the fragmentation
process and study several fragmentation mechanisms. The evolution of meridional
cracks is studied in detail. These cracks are found to initiate in the inside
of the specimen with quasi-periodic angular distribution. The fragments that
are formed when these cracks penetrate the specimen surface give a broad peak
in the fragment mass distribution for large fragments that can be fitted by a
two-parameter Weibull distribution. This mechanism can only be observed in 3D
models or experiments. The results prove to be independent of the degree of
disorder in the model. Our results significantly improve the understanding of
the fragmentation process for impact fracture since besides reproducing the
experimental observations of fragment shapes, impact energy dependence and mass
distribution, we also have full access to the failure conditions and evolution.


title:
Gauge Theory Duals of Cosmological Backgrounds and their Energy Momentum
  Tensors

abstract:
  We revisit Type IIB supergravity backgrounds with null and spacelike
singularities with natural gauge theory duals proposed in {\tt hep-th/0602107}
and {\tt hep-th/0610053}. We show that for these backgrounds there are always
choices of the boundaries of these deformed $AdS_5 \times S^5$ space-times,
such that the dual gauge theories live on {\it flat} metrics and have
space-time dependent couplings. We present a new time dependent solution of
this kind where the effective string coupling is always bounded and vanishes at
a spacelike singularity in the bulk, and the space-time becomes $AdS_5 \times
S^5$ at early and late times. The holographic energy momentum tensor calculated
with a choice of flat boundary is shown to vanish for null backgrounds and to
be generically non-zero for time dependent backgrounds.


title: How can we explore the onset of deconfinement by experiment?

abstract:
  There is little doubt that Quantumchromodynamics (QCD) is the theory which
describes strong interaction physics. Lattice gauge simulations of QCD predict
that in the $\mu,T$ plane there is a line where a transition from confined
hadronic matter to deconfined quarks takes place. The transition is either a
cross over (at low $\mu$) or of first order (at high $\mu$). It is the goal of
the present and future heavy ion experiment at RHIC and FAIR to study this
phase transition at different locations in the $\mu,T$ plane and to explore the
properties of the deconfined phase. It is the purpose of this contribution to
discuss some of the observables which are considered as useful for this
purpose.


title: The Kohn-Sham system in one-matrix functional theory

abstract:
  A system of electrons in a local or nonlocal external potential can be
studied with 1-matrix functional theory (1MFT), which is similar to density
functional theory (DFT) but takes the one-particle reduced density matrix
(1-matrix) instead of the density as its basic variable. Within 1MFT, Gilbert
derived [PRB 12, 2111 (1975)] effective single-particle equations analogous to
the Kohn-Sham (KS) equations in DFT. The self-consistent solution of these
1MFT-KS equations reproduces not only the density of the original electron
system but also its 1-matrix. While in DFT it is usually possible to reproduce
the density using KS orbitals with integer (0 or 1) occupancy, in 1MFT
reproducing the 1-matrix requires in general fractional occupancies. The
variational principle implies that the KS eigenvalues of all fractionally
occupied orbitals must collapse at self-consistency to a single level, equal to
the chemical potential. We show that as a consequence of the degeneracy the
iteration of the KS equations is intrinsically divergent. Fortunately, the
level shifting method, commonly introduced in Hartree-Fock calculations, is
always able to force convergence. We introduce an alternative derivation of the
1MFT-KS equations that allows control of the eigenvalue collapse by
constraining the occupancies. As an explicit example, we apply the 1MFT-KS
scheme to calculate the ground state 1-matrix of an exactly solvable two-site
Hubbard model.


title: Completing Continuum Coulomb Gauge in the Functional Formalism

abstract:
  It is argued that within the continuum functional formalism, there is no need
to supply a further (spatially independent) gauge constraint to complete the
Coulomb gauge of Yang-Mills theory. It is shown explicitly that a natural
completion of the gauge-fixing leads to a contradiction with the perturbative
renormalizability of the theory.


title: Optimizing diversity

abstract:
  We consider the problem of minimizing the size of a family of sets G such
that every subset of 1,...,n can be written as a disjoint union of at most k
members of G, where k and n are given numbers. This problem originates in a
real-world application aiming at the diversity of industrial production. At the
same time, the minimum of G so that every subset of 1,...,n is the union of two
sets in G has been asked by Erdos and studied recently by Furedi and Katona
without requiring the disjointness of the sets. A simple construction providing
a feasible solution is conjectured to be optimal for this problem for all
values of n and k and regardless of the disjointness requirement; we prove this
conjecture in special cases including all (n,k) for which n <= 3k holds, and
some individual values of n and k.


title: Solvable Metric Growing Networks

abstract:
  Structure and dynamics of complex networks usually deal with degree
distributions, clustering, shortest path lengths and other graph properties.
Although these concepts have been analysed for graphs on abstract spaces, many
networks happen to be embedded in a metric arrangement, where the geographic
distance between vertices plays a crucial role. The present work proposes a
model for growing network that takes into account the geographic distance
between vertices: the probability that they are connected is higher if they are
located nearer than farther. In this framework, the mean degree of vertices,
degree distribution and shortest path length between two randomly chosen
vertices are analysed.


title: Quantum Mechanics and imprecise probability

abstract:
  An extension of the Born rule, the {\it quantum typicality rule}, has
recently been proposed [B. Galvan: Found. Phys. 37, 1540-1562 (2007)]. Roughly
speaking, this rule states that if the wave function of a particle is split
into non-overlapping wave packets, the particle stays approximately inside the
support of one of the wave packets, without jumping to the others.
  In this paper a formal definition of this rule is given in terms of {\it
imprecise probability}. An imprecise probability space is a measurable space
$(\Omega, {\cal A})$ endowed with a {\it set} of probability measures $\cal P$.
The quantum formalism and the quantum typicality rule allow us to define a set
of probabilities ${\cal P}_\Psi$ on $(X^T, {\cal F})$, where $X$ is the
configuration space of a quantum system, $T$ is a time interval and ${\cal F}$
is the $\sigma$-algebra generated by the cylinder sets. Thus, it is proposed
that a quantum system can be represented as the {\it imprecise stochastic
process} $(X^T, {\cal F}, {\cal P}_\Psi)$, which is a canonical stochastic
process in which the single probability measure is replaced by a set of
measures. It is argued that this mathematical model, when used to represent
macroscopic systems, has sufficient predictive power to explain both the
results of the statistical experiments and the quasi-classical structure of the
macroscopic evolution.


title: Formation of Millisecond Pulsars in Globular Clusters

abstract:
  In this contribution we discuss how neutron stars are produced and retained
in globular clusters, outlining the most important dynamical channels and
evolutionary events that affect thepopulation of mass-transferring binaries
with neutron stars and result in the formation of recycled pulsars. We confirm
the importance of electron-capture supernovae in globular clusters as the major
supplier of retained neutron stars.By comparing the observed millisecond pulsar
population and the results obtained from simulations, we discuss several
constraints on the evolution of mass-transferring systems.In particular, we
find that in our cluster model the following mass-gaining events create
populations of MSPs that do not match the observations (with respect to binary
periods and companion masses or the number of produced systems) and therefore
likely do not lead to NSs spun up to millisecond periods: (i) accretion during
a common envelope event with a NS formed through accretion-induced collapse,
and (ii) mass transfer from a WD donor. By restricting ourselves to the
evolutionary and dynamical paths that most likely lead to neutron star
recycling, we obtain good agreement between our models and the numbers and
characteristics of observed millisecond pulsars in the clusters Terzan 5 and 47
Tuc.


title:
Probing phase coexistence and stabilization of the spin-ordered
  ferrimagnetic state by Calcium addition in the YBa_{1-x}Ca_{x}Co_{2}O_{5.5}
  layered cobaltites using neutron diffraction

abstract:
  In this article we study the effects of a partial substitution of Ba with the
smaller cation Ca in the layered cobaltites YBaCo_2O_{5+\delta} for \delta
\approx 0.5. Neutron thermodiffractograms are reported for the compounds
YBa_{0.95}Ca_{0.05}Co_2O_{5.5} (x_{Ca}=0.05) and YBa_{0.90}Ca_{0.10}Co_2O_{5.5}
(x_{Ca}=0.10) in the temperature range 20 K \leq T \leq 300 K, as well as high
resolution neutron diffraction experiments at selected temperatures for the
samples x_{Ca}=0.05, x_{Ca}=0.10 and the parent compound x_{Ca}=0. We have
found the magnetic properties to be strongly affected by the cationic
substitution. Although the "122" perovskite structure seems unaffected by Ca
addition, the magnetic arrangements of Co ions are drastically modified: the
antiferromagnetic (AFM) long-range order is destroyed, and a ferrimagnetic
phase with spin state order is stabilized below T \sim 290 K. For the sample
with x_{Ca}=0.05 a fraction of AFM phase coexists with the ferrimagnetic one
below T \sim 190 K, whereas for x_{Ca}=0.10 the AFM order is completely lost.
The systematic refinement of the whole series has allowed for a better
understanding of the observed low-temperature diffraction patterns of the
parent compound, YBaCo_2O_{5.5}, which had not yet been clarified. A two-phase
scenario is proposed for the x_{Ca}=0 compound which is compatible with the
phase coexistence observed in the x_{Ca}=0.05 sample.


title: Electroweak Physics at the ILC

abstract:
  Some aspects of electroweak physics at the International Linear Collider
(ILC) are reviewed. The importance of precision measurements in the Higgs
sector and in top-quark physics is emphasized, and the physics potential of the
GigaZ option of the ILC is discussed. It is shown in particular that even in a
scenario where the states of new physics are so heavy that they would be
outside of the reach of the LHC and the first phase of the ILC, the GigaZ
precision on the effective weak mixing angle may nevertheless allow the
detection of quantum effects of new physics.


title: Computational Methods in Quantum Field Theory

abstract:
  After a brief introduction to the statistical description of data, these
lecture notes focus on quantum field theories as they emerge from lattice
models in the critical limit. For the simulation of these lattice models,
Markov chain Monte-Carlo methods are widely used. We discuss the heat bath and,
more modern, cluster algorithms. The Ising model is used as a concrete
illustration of important concepts such as correspondence between a theory of
branes and quantum field theory or the duality map between strong and weak
couplings. The notes then discuss the inclusion of gauge symmetries in lattice
models and, in particular, the continuum limit in which quantum Yang-Mills
theories arise.


title:
Gamma Ray Burst engine activity within the quark nova scenario: Prompt
  emission, X-ray Plateau, and sharp drop-off

abstract:
  We present a three-stage model for a long GRB inner engine to explain the
prompt gamma ray emission, and interpret recent Swift satellite observations of
early X-ray afterglow plateaus followed by a sharp drop off or a shallow power
law decay. The three stages involves a neutron star phase, a quark star (QS)
and a black hole phase as described in Staff et al. (2007). We find that the QS
stage allows for more energy to be extracted from neutron star to QS conversion
as well as from ensuing accretion onto the QS. The QS accretion phase naturally
extends the engine activity and can account for both the prompt emission and
irregular early X-ray afterglow activity. Following the accretion phase, the QS
can spin-down by emission of a baryon-free outflow. The magnetar-like magnetic
field strengths resulting from the NS to QS transition provide enough spin-down
energy, for the correct amount of time, to account for the plateau in the X-ray
afterglow. In our model, a sharp drop-off following the plateau occurs when the
QS collapses to a BH during the spin-down, thus shutting-off the secondary
outflow. We applied our model to GRB 070110 and GRB 060607A and found that we
can consistently account for the energetics and duration during the prompt and
plateau phases.


title: Strongly paired fermions: Cold atoms and neutron matter

abstract:
  Experiments with cold Fermi atoms can be tuned to probe strongly interacting
fluids that are very similar to the low-density neutron matter found in the
crusts of neutron stars. In contrast to traditional superfluids and
superconductors, matter in this regime is very strongly paired, with gaps of
the order of the Fermi energy. We compute the T=0 equation of state and pairing
gap for cold atoms and low-density neutron matter as a function of the Fermi
momentum times the scattering length. Results of quantum Monte Carlo
calculations show that the equations of state are very similar. The neutron
matter pairing gap at low densities is found to be very large but, except at
the smallest densities, significantly suppressed relative to cold atoms because
of the finite effective range in the neutron-neutron interaction.


title:
Modulation of the gravitational waveform by the effect of radiation
  reaction

abstract:
  When we calculate gravitational waveforms from extreme-mass-ratio inspirals
(EMRIs) by metric perturbation, it is a common strategy to use the adiabatic
approximation. Under that approximation, we first calculate the linear metric
perturbation induced by geodesics orbiting a black hole, then we calculate the
adiabatic evolution of the parameters of geodesics due to the radiation
reaction effect through the calculation of the self-force. This procedure is
considered to be reasonable, however, there is no direct proof that it can
actually produce the correct waveform we would observe. In this paper, we study
the formal expression of the second order metric perturbation and show that it
be expressed as the linear metric perturbation modulated by the adiabatic
evolution of the geodesic. This evidence supports the assumption that the
adiabatic approximation can produce the correct waveform, and that the
adiabatic expansion we propose in Ref.\cite{adi} is an appropriate perturbation
expansion for studying the radiation reaction effect on the gravitational
waveform.


title:
The Galactic Positron Annihilation Radiation & The Propagation of
  Positrons in the Interstellar Medium

abstract:
  We consider positron propagation in the interstellar medium and show that the
positrons from the beta-plus decay chains of the radioactive nuclei Ni-56,
Ti-44, and Al-26, produced in Galactic supernovae, can fully account for all
the features of the diffuse Galactic 511 keV annihilation radiation observed by
INTEGRAL/SPI. We also predict additional measurable features that can further
test the origin of positrons and provide new information on the nature of the
interstellar medium.


title:
An asymptotic behavior of the dilatation for a family of pseudo-Anosov
  braids

abstract:
  The dilatation of a pseudo-Anosov braid is a conjugacy invariant. In this
paper, we study the dilatation of a special family of pseudo-Anosov braids. We
prove an inductive formula to compute their dilatation, a monotonicity and an
asymptotic behavior of the dilatation for this family of braids. We also give
an example of a family of pseudo-Anosov braids with arbitrarily small
dilatation such that the mapping torus obtained from such braid has 2 cusps and
has an arbitrarily large volume.


title: Azimuthal anisotropy of direct photons

abstract:
  The electromagnetic bremsstrahlung produced by a quark interacting with
nucleons or nuclei is azimuthally asymmetric. In the light-cone dipole approach
this effect is related to the orientation dependent dipole cross section. Such
a radiation anisotropy is expected to contribute to the azimuthal asymmetry of
direct photons in pA and AA collisions, as well as in DIS and in the production
of dileptons.


title: Absolutely Indecomposable Modules

abstract:
  A module is called absolutely indecomposable if it is directly indecomposable
in every generic extension of the universe. We want to show the existence of
large abelian groups that are absolutely indecomposable. This will follow from
a more general result about R-modules over a large class of commutative rings R
with endomorphism ring R which remains the same when passing to a generic
extension of the universe. It turns out that `large' in this context has the
precise meaning, namely being smaller then the first omega-Erdos cardinal
defined below. We will first apply result on large rigid trees with a similar
property established by Shelah in 1982, and will prove the existence of related
` R_omega-modules' (R-modules with countably many distinguished submodules) and
finally pass to R-modules. The passage through R_omega-modules has the great
advantage that the proofs become very transparent essentially using a few
`linear algebra' arguments accessible also for graduate students. The result
gives a new construction of indecomposable modules in general using a counting
argument.


title:
BlackMax: A black-hole event generator with rotation, recoil, split
  branes and brane tension

abstract:
  We present a comprehensive black-hole event generator, BlackMax, which
simulates the experimental signatures of microscopic and Planckian black-hole
production and evolution at the LHC in the context of brane world models with
low-scale quantum gravity. The generator is based on phenomenologically
realistic models free of serious problems that plague low-scale gravity, thus
offering more realistic predictions for hadron-hadron colliders. The generator
includes all of the black-hole graybody factors known to date and incorporates
the effects of black-hole rotation, splitting between the fermions, non-zero
brane tension and black-hole recoil due to Hawking radiation (although not all
simultaneously).
  The generator can be interfaced with Herwig and Pythia.


title: Natural realizations of sparsity matroids

abstract:
  A hypergraph G with n vertices and m hyperedges with d endpoints each is
(k,l)-sparse if for all sub-hypergraphs G' on n' vertices and m' edges, m'\le
kn'-l. For integers k and l satisfying 0\le l\le dk-1, this is known to be a
linearly representable matroidal family.
  Motivated by problems in rigidity theory, we give a new linear representation
theorem for the (k,l)-sparse hypergraphs that is natural; i.e., the
representing matrix captures the vertex-edge incidence structure of the
underlying hypergraph G.


title: On The Survival and Abundance of Disk-dominated Galaxies

abstract:
  We study the formation of disk-dominated galaxies in a Lambda CDM universe.
Their existence is considered to be a challenge for the Lambda CDM cosmology,
because galaxy mergers isotropize stellar disks and trigger angular momentum
transport in gas disks, thus fostering the formation of central stellar
spheroids. Here, we postulate that the formation of stellar spheroids from
gas-rich disks is controlled by two parameters that characterize galaxy
mergers, the mass ratio of merging dark matter halos, and the virial velocity
of the larger merging halo. We utilize merger histories generated from
realizations of the cosmological density field to calculate the fraction of
dark matter halos that have avoided spheroid formation, and compare the derived
statistics with the spheroid occupation fractions in surveys of nearby
galaxies. We find, for example, that the survival rate of disk-dominated
galaxies in Lambda CDM is just high enough to explain the observed fractional
representation of disk-dominated galaxies in the universe if the only mergers
which lead to central spheroid formation are those with mass ratios M2/M1 > 0.3
and virial velocities Vvir,1 > 55 km/s. We discuss the physical origin of this
criterion.


title: Quantum magnetism and criticality

abstract:
  Magnetic insulators have proved to be fertile ground for studying new types
of quantum many body states, and I survey recent experimental and theoretical
examples. The insights and methods transfer also to novel superconducting and
metallic states. Of particular interest are critical quantum states, sometimes
found at quantum phase transitions, which have gapless excitations with no
particle- or wave-like interpretation, and control a significant portion of the
finite temperature phase diagram. Remarkably, their theory is connected to
holographic descriptions of Hawking radiation from black holes.

categories: cond-mat.str-el cond-mat.supr-con hep-th quant-ph


title: Diluted antiferromagnet in a ferromagnetic enviroment

abstract:
  The question of robustness of a network under random ``attacks'' is treated
in the framework of critical phenomena. The persistence of spontaneous
magnetization of a ferromagnetic system to the random inclusion of
antiferromagnetic interactions is investigated. After examing the static
properties of the quenched version (in respect to the random antiferromagnetic
interactions) of the model, the persistence of the magnetization is analysed
also in the annealed approximation, and the difference in the results are
discussed.


title:
Dynamic plasticity of beryllium in the inertial fuel fusion capsule
  regime

abstract:
  The plastic response of beryllium was investigated during loading by
laser-induced shock waves, using surface velocimetry and in-situ x-ray
diffraction. Results from loading by thermal x-rays (hohlraum) were consistent
with more extensive studies using laser ablation. Strong elastic waves were
observed, up to ~1 km/s in free surface speed, with significant structure
before the arrival of the plastic shock. The magnitude and shape of the
precursor could be reproduced with a plasticity model based on dislocation
dynamics. Changes in lattice spacing measured from the x-ray diffraction
pattern gave a direct measurement of uniaxial compression in the elastic wave,
triaxial flow from the decay of the precursor, and triaxial compression in the
plastic shock; these were consistent with the velocity data. The dynamic
strength behavior deduced from the laser experiments was used to help interpret
surface velocity data around the onset of shock-induced melting. A model of
heterogeneous mixtures is being extended to treat anisotropic components, and
spall.


title: Higgs Self-Coupling as a Probe of Electroweak Phase Transition

abstract:
  We argue that, within a broad class of extensions of the Standard Model,
there is a tight corellation between the dynamics of the electroweak phase
transition and the cubic self-coupling of the Higgs boson: Models which exhibit
a strong first-order EWPT predict a large deviation of the Higgs self-coupling
from the Standard Model prediction, as long as no accidental cancellations
occur. Order-one deviations are typical. This shift would be observable at the
Large Hadron Collider if the proposed luminosity or energy upgrades are
realized, as well as at a future electron-positron collider such as the
proposed International Linear Collider. These measurements would provide a
laboratory test of the dynamics of the electroweak phase transition.


title: Quantum-Space Attacks

abstract:
  Theoretical quantum key distribution (QKD) protocols commonly rely on the use
of qubits (quantum bits). In reality, however, due to practical limitations,
the legitimate users are forced to employ a larger quantum (Hilbert) space, say
a quhexit (quantum six-dimensional) space, or even a much larger quantum
Hilbert space. Various specific attacks exploit of these limitations. Although
security can still be proved in some very special cases, a general framework
that considers such realistic QKD protocols, as well as} attacks on such
protocols, is still missing.
  We describe a general method of attacking realistic QKD protocols, which we
call the `quantum-space attack'. The description is based on assessing the
enlarged quantum space actually used by a protocol, the `quantum space of the
protocol'. We demonstrate these new methods by classifying various (known)
recent attacks against several QKD schemes, and by analyzing a novel attack on
interferometry-based QKD.


title:
A Singlet-pairing superconductor is always also a
  super-spin-current-conductor

abstract:
  It is shown that, in a conductor carrying a moderate spin current, singlet
pairing can still take place almost as effectively as without a spin current.
The system will still be fully gapped for all spin-up and -down single-particle
excitations, with no depaired electrons. All thermodynamic properties will be
practically the same as without the spin current. All universality relations
and laws of corresponding states found in the theory of Bardeen, Cooper, and
Schrieffer should remain valid. Thus a singlet-pairing superconductor can
always carry a persistent and dissipation-less spin-current. A heuristic
argument to support this conclusion is also given, as well as two possible
experimental tests of this prediction.


title: Emergence of quasi-units in the one dimensional Zhang model

abstract:
  We study the Zhang model of sandpile on a one dimensional chain of length
$L$, where a random amount of energy is added at a randomly chosen site at each
time step. We show that in spite of this randomness in the input energy, the
probability distribution function of energy at a site in the steady state is
sharply peaked, and the width of the peak decreases as $ {L}^{-1/2}$ for large
$L$. We discuss how the energy added at one time is distributed among different
sites by topplings with time. We relate this distribution to the time-dependent
probability distribution of the position of a marked grain in the one
dimensional Abelian model with discrete heights. We argue that in the large $L$
limit, the variance of energy at site $x$ has a scaling form $L^{-1}g(x/L)$,
where $g(\xi)$ varies as $\log(1/\xi)$ for small $\xi$, which agrees very well
with the results from numerical simulations.


title: Search for Ultra High-Energy Neutrinos with AMANDA-II

abstract:
  A search for diffuse neutrinos with energies in excess of 10^5 GeV is
conducted with AMANDA-II data recorded between 2000 and 2002. Above 10^7 GeV,
the Earth is essentially opaque to neutrinos. This fact, combined with the
limited overburden of the AMANDA-II detector (roughly 1.5 km), concentrates
these ultra high-energy neutrinos at the horizon. The primary background for
this analysis is bundles of downgoing, high-energy muons from the interaction
of cosmic rays in the atmosphere. No statistically significant excess above the
expected background is seen in the data, and an upper limit is set on the
diffuse all-flavor neutrino flux of E^{-2} $\Phi$_{90%CL} < 2.7 $\times$
10^{-7} GeV cm^{-2} s^{-1} sr^{-1} valid over the energy range of 2 $\times$
10^5 GeV to 10^9 GeV. A number of models which predict neutrino fluxes from
active galactic nuclei are excluded at the 90% confidence level.


title: Stacky Abelianization of an Algebraic Group

abstract:
  Let G be a connected algebraic group and let [G,G] be its commutator
subgroup. We prove a conjecture of Drinfeld about the existence of a connected
etale group cover H of [G,G], characterized by the following properties: every
central extension of G, by a finite etale group scheme, splits over H, and the
commutator map of G lifts to H. We prove, moreover, that the quotient stack of
G by the natural action of H is the universal Deligne-Mumford Picard stack to
which G maps.


title: Progress in measuring neutrino quasielastic interactions

abstract:
  This is an exciting time for folks who are looking at neutrino cross
sections, and the especially important quasielastic interaction. We are able to
inspect several recent results from K2K and MiniBooNE and are looking forward
to a couple more high statistics measurements of neutrino and anti-neutrino
interactions. There is additional interest because of the need for this cross
section information for current and upcoming neutrino oscillation experiments.
This paper is a brief review of our current understanding and some puzzles when
we compare the recent results with past measurements. I articulate some of the
short term challenges facing experimentalists, neutrino event generators, and
theoretical work on the quasielastic interaction.


title:
Synoptic studies of seventeen blazars detected in very high-energy
  gamma-rays

abstract:
  Since 2002, the number of detected blazars at gamma-ray energies above 100
GeV has more than doubled. I study 17 blazars currently known to emit E>100 GeV
gamma rays. Their intrinsic energy spectra are reconstructed by removing
extragalactic background light attenuation effects. Luminosity and spectral
slope in the E>100 GeV region are then compared and correlated among each
other, with X-ray, optical and radio data, and with the estimated black hole
(BH) masses of the respective host galaxies.
  According to expectations from synchrotron self-Compton emission models, a
correlation on the 3.6-sigma significance level between gamma-ray and X-ray
fluxes is found, while correlations between gamma-ray and optical/radio fluxes
are less pronounced. Further, a general hardening of the E>100 GeV spectra with
increasing gamma-ray luminosity is observed. This goes in line with a
correlation of the gamma-ray luminosity and the synchrotron peak frequency,
which is also seen. Tests for possible selection effects reveal a hardening of
the spectra with increasing redshift. The gamma-ray emission might depend on
the mass of the central BH. The studied blazars show no correlation of the BH
masses with the spectral index and the luminosity in the E>100 GeV region.
  Also temporal properties of the X-ray and E>100 GeV gamma-ray flux are
considered. No general trends are found, except that the blazars with the most
massive BHs do not show particularly high duty cycles. In general, VHE flare
time-scales are not found to scale with the BH mass.
  As a specific application of the luminosity study, a constraint for the still
undetermined redshift of the blazar PG 1553+113 is discussed.


title: Strings on conifolds from strong coupling dynamics: quantitative results

abstract:
  Three quantitative features of string theory on AdS_5 x X_5, for any
(quasi)regular Sasaki-Einstein X_5, are recovered exactly from an expansion of
field theory at strong coupling around configurations in the moduli space of
vacua. These configurations can be thought of as a generalized matrix model of
(local) commuting matrices. First, we reproduce the spectrum of scalar
Kaluza-Klein modes on X_5. Secondly, we recover the precise spectrum of BMN
string states, including a nontrivial dependence on the volume of X_5. Finally,
we show how the radial direction in global AdS_5 emerges universally in these
theories by exhibiting states dual to AdS giant gravitons.


title: The narrow escape problem revisited

abstract:
  The time needed for a particle to exit a confining domain through a small
window, called the narrow escape time (NET), is a limiting factor of various
processes, such as some biochemical reactions in cells. Obtaining an estimate
of the mean NET for a given geometric environment is therefore a requisite step
to quantify the reaction rate constant of such processes, which has raised a
growing interest in the last few years. In this Letter, we determine explicitly
the scaling dependence of the mean NET on both the volume of the confining
domain and the starting point to aperture distance. We show that this
analytical approach is applicable to a very wide range of stochastic processes,
including anomalous diffusion or diffusion in the presence of an external force
field, which cover situations of biological relevance.


title: A noncommutative Atiyah-Patodi-Singer index theorem in KK-theory

abstract:
  We investigate an extension of ideas of Atiyah-Patodi-Singer (APS) to a
noncommutative geometry setting framed in terms of Kasparov modules. We use a
mapping cone construction to relate odd index pairings to even index pairings
with APS boundary conditions in the setting of KK-theory, generalising the
commutative theory. We find that Cuntz-Kreiger systems provide a natural class
of examples for our construction and the index pairings coming from APS
boundary conditions yield complete K-theoretic information about certain graph
C*-algebras.


title: The MINERvA Neutrino Interaction Experiment

abstract:
  The MINERvA neutrino interaction experiment in the NuMI beam at Fermilab will
measure several aspects of neutrino interactions in the few GeV energy region.
We will make cross section and form factor measurements using a fine-grained
fully active scintillator (CH) target, and also investigate nuclear effects on
neutrino interactions as well as hadron rescattering using integral nuclear
targets made of helium, carbon, iron, and lead. We will improve or add to
existing measurements and address some specific questions that are important
for current and upcoming neutrino oscillation experiments. This paper reports
on the progress toward the design, construction, and calibration of the
detector, which we expect will get its first neutrino beam in 2009.


title: Diamonds

abstract:
  We prove, e.g., that if lambda=chi^+=2^chi and S subseteq
{delta<lambda:cf(delta) neq cf(chi)} is stationary then diamondsuit_lambda
holds true.


title: Basic Subgroups and Freeness, A Counterexample

abstract:
  We construct a non-free but aleph_1-separable, torsion-free abelian group G
with a pure free subgroup B such that all subgroups of G disjoint from B are
free and such that G/B is divisible. This answers a question of Irwin and shows
that a theorem of Blass and Irwin cannot be strengthened so as to give an exact
analog for torsion-free groups of a result proved for p-groups by Benabdallah
and Irwin.


title: Pseudo focal points along Lorentzian geodesics and Morse index

abstract:
  Given a Lorentzian manifold $(M,g)$, a geodesic $\gamma$ in $M$ and a
timelike Jacobi field $\mathcal Y$ along $\gamma$, we introduce a special class
of instants along $\gamma$ that we call $\mathcal Y$-pseudo conjugate (or focal
relatively to some initial orthogonal submanifold). We prove that the $\mathcal
Y$-pseudo conjugate instants form a finite set, and their number equals the
Morse index of (a suitable restriction of) the index form. This gives a
Riemannian-like Morse index theorem. As special cases of the theory, we will
consider geodesics in stationary and static Lorentzian manifolds, where the
Jacobi field $\mathcal Y$ is obtained as the restriction of a globally defined
timelike Killing vector field.


title:
Searching for Kaluza-Klein Dark Matter Signatures in the LAT Electron
  Flux

abstract:
  We present here the prospects for the GLAST Large Area Telescope (LAT)
detection of the signature of the lightest Kaluza-Klein particle (LKP). It
decays by direct annihilation into electron-positron pairs that may be
detectable in the high energy electron flux. We discuss the LAT capability for
detecting the high energy (20 GeV - ~1 TeV) cosmic ray electron flux and we
analyze the LAT sensitivity to detect LKP-produced electrons for various
particle masses. We include an analysis of the diffusive propagation of the
electrons in the galaxy.


title: Different progenitors of short hard gamma-ray bursts

abstract:
  We consider the spatial offsets of short hard gamma-ray bursts (SHBs) from
their host galaxies. We show that all SHBs with extended duration soft emission
components lie very close to their hosts. We suggest that NS-BH binary mergers
offer a natural explanation for the properties of this extended duration/low
offset group. SHBs with large offsets have no observed extended emission
components and are less likely to have an optically detected afterglow,
properties consistent with NS-NS binary mergers occurring in low density
environments.


title: Statistical Inference for Disordered Sphere Packings

abstract:
  Sphere packings are essential to the development of physical models for
powders, composite materials, and the atomic structure of the liquid state.
There is a strong scientific need to be able to assess the fit of packing
models to data, but this is complicated by the lack of formal probabilistic
models for packings. Without formal models, simulation algorithms and
collections of physical objects must be used as models. Identification of
common aspects of different realizations of the same packing process requires
the use of new descriptive statistics, many of which have yet to be developed.
Model assessment will require the use of large samples of independent and
identically distributed realizations, rather than the large single stationary
realizations found in conventional spatial statistics. The development of
procedures for model assessment will resemble the development of thermodynamic
models, and will be based on much exploration and experimentation rather than
on extensions of established statistical methods.


title: Calculation of bound states and resonances in perturbed Coulomb models

abstract:
  We calculate accurate bound states and resonances of two interesting
perturbed Coulomb models by means of the Riccati-Pad\'{e} method. This approach
is based on a rational approximation to a modified logarithmic derivative of
the eigenfunction and produces sequences of roots of Hankel determinants that
converge towards the eigenvalues of the equation.


title: Tie-points and fixed-points in N^*

abstract:
  A point x is a (bow) tie-point of a space X if X setminus {x} can be
partitioned into (relatively) clopen sets each with x in its closure.
Tie-points have appeared in the construction of non-trivial autohomeomorphisms
of betaN setminus N and in the recent study of (precisely) 2-to-1 maps on betaN
setminus N . In these cases the tie-points have been the unique fixed point of
an involution on betaN setminus N. This paper is motivated by the search for
2-to-1 maps and obtaining tie-points of strikingly differing characteristics.


title: More on Tie-points and homeomorphism in N^*

abstract:
  A point x is a (bow) tie-point of a space X if X setminus {x} can be
partitioned into (relatively) clopen sets each with x in its closure.
Tie-points have appeared in the construction of non-trivial autohomeomorphisms
of betaN setminus N= N^* and in the recent study of (precisely) 2-to-1 maps on
N^*. In these cases the tie-points have been the unique fixed point of an
involution on N^*. One application of the results in this paper is the
consistency of there being a 2-to-1 continuous image of N^* which is not a
homeomorph of N^* .


title:
Wilson line correlator in the MV model: relating the glasma to deep
  inelastic scattering

abstract:
  In the color glass condensate framework the saturation scale measured in deep
inelastic scattering of high energy hadrons and nuclei can be determined from
the correlator of Wilson lines in the hadron wavefunction. These same Wilson
lines give the initial condition of the classical field computation of the
initial gluon multiplicity and energy density in a heavy ion collision. In this
paper the Wilson line correlator in both adjoint and fundamental
representations is computed using exactly the same numerical procedure that has
been used to calculate gluon production in a heavy ion collision. In particular
the discretization of the longitudinal coordinate has a large numerical effect
on the relation between the color charge density parameter g^2 mu and the
saturation scale Qs. Our result for this relation is Qs = 0.6 g^2 mu, which
results in the classical Yang-Mills value for the "gluon liberation
coefficient" c = 1.1.


title: Quantifying Disorder in Point Patterns

abstract:
  Disorder in point patterns can be quantified by means of the complexity,
rather than in terms of geometric attributes of pattern structure. A
complexity-based disorder-quantifying statistic indicates the practical
difficulties associated with modeling processes that produce jammed patterns,
particularly with the assessment of model fit and with the simulation of
high-intensity hard-core patterns.


title: LIGO: The Laser Interferometer Gravitational-Wave Observatory

abstract:
  The goal of the Laser Interferometric Gravitational-Wave Observatory (LIGO)
is to detect and study gravitational waves of astrophysical origin. Direct
detection of gravitational waves holds the promise of testing general
relativity in the strong-field regime, of providing a new probe of exotic
objects such as black hole and neutron stars, and of uncovering unanticipated
new astrophysics. LIGO, a joint Caltech-MIT project supported by the National
Science Foundation, operates three multi-kilometer interferometers at two
widely separated sites in the United States. These detectors are the result of
decades of worldwide technology development, design, construction, and
commissioning. They are now operating at their design sensitivity, and are
sensitive to gravitational wave strains smaller than 1 part in 1E21. With this
unprecedented sensitivity, the data are being analyzed to detect or place
limits on gravitational waves from a variety of potential astrophysical
sources.


title:
A free-boundary problem for the evolution $p$-Laplacian equation with a
  combustion boundary condition

abstract:
  We study the existence, uniqueness and regularity of solutions of the
equation $f_t = \Delta_p f = \text{div} (|Df|^{p-2} Df)$ under over-determined
boundary conditions $f = 0$ and $|Df| = 1$. We show that if the initial data is
concave and Lipschitz with a bounded and convex support, then the problem
admits a unique solution which exists until it vanishes identically.
Furthermore, the free-boundary of the support of $f$ is smooth for all positive
time.


title: Karp height of models of stable theories

abstract:
  A trichotomy theorem for countable, stable, unsuperstable theories is
offered. We develop the notion of a `regular ideal' of formulas and study types
that are minimal with respect to such an ideal.


title: Charm Physics Opportunities at a Super Flavor Factory

abstract:
  The primary physics goals of a high luminosity e+e- flavor factory are
discussed, including the possibilities to perform detailed studies of the CKM
mechanism of quark mixing, and constrain virtual Higgs and non-standard model
particle contributions to the dynamics of rare B_{u,d,s} decays. The large
samples of D mesons and tau leptons produced at a flavor factory will result in
improved sensitivities to rare D processes - mixing, CP violation and rare
decays - and lepton flavor violation searches, respectively. Recent
developments in accelerator physics have demonstrated the feasibility to build
an accelerator that can achieve luminosities of ~10^36 cm-2 s^-1 at sqrt{s}=10
GeV. The capablity to run at sqrt{s}=3.770 GeV with luminosity of ~10^35 cm^-2
s^-1 is included in the initial design. This report emphasizes the charm
physics that can be probed at a Super Flavor Factory.


title: Generalized E-Algebras via lambda-Calculus I

abstract:
  An R-algebra A is called E(R)-algebra if the canonical homomorphism from A to
the endomorphism algebra End_RA of the R-module {}_R A, taking any a in A to
the right multiplication a_r in End_R A by a is an isomorphism of algebras. In
this case {}_R A is called an E(R)-module. E(R)-algebras come up naturally in
various topics of algebra, so it's not surprising that they were investigated
thoroughly in the last decade. Despite some efforts it remained an open
question whether proper generalized E(R)-algebras exist. These are R-algebras A
isomorphic to End_R A but not under the above canonical isomorphism, so not
E(R)-algebras. This question was raised about 30 years ago (for R=Z) by Phil
Schultz and we will answer it. For PIDs R of characteristic 0 that are neither
quotient fields nor complete discrete valuation rings - we will establish the
existence of generalized E(R)-algebras. It can be shown that E(R)-algebras over
rings R that are complete discrete valuation rings or fields must trivial
(copies of R). The main tool is an interesting connection between
lambda-calculus (used in theoretical computer sciences) and algebra. It seems
reasonable to divide the work into two parts, in this paper we will work in V=L
(Godel universe) hence stronger combinatorial methods make the final arguments
more transparent. The proof based entirely on ordinary set theory (the axioms
of ZFC) will appear in a subsequent paper.


title:
The gravitational wave signal of the short rise fling of galactic run
  away pulsars

abstract:
  Determination of pulsar parallaxes and proper motions addresses fundamental
astrophysical open issues. Here, the ATNF Catalog is scrutinized searching for
pulsar distances and proper motions. For a sample of 212 run away pulsars
(RAPs), which currently run across the Galaxy at very high speed and undergo
large displacements, some gravitational-wave (GW) signals produced by such
present accelerations appear to be detectable after calibration against the
Advanced LIGO (LIGO II). Motivated by this insight, we address the issue of the
pulsar kick at birth. We show that during the short rise fling each run away
pulsar (RAP) generates a GW signal with characteristic amplitude and frequency
that makes it detectable by current GW interferometers. For a realistic
analysis, an efficiency parameter is introduced to quantify the expenditure of
the rise fling kinetic energy, which is estimated from the linear momentum
conservation law applied to the supernova explosion that kicks out the pulsar.
The remaining energy is supposed to be used to make the star to spin. Thus, a
comparison with the spin of ATNF pulsars having velocity in the interval
400-500 km s$^{-1}$ is performed. The resulting difference suggests that other
mechanisms should dissipate part of that energy to produce the observed pulsar
spin periods. Meanwhile, the kick phenomenon may also occur in globular and
open star clusters at the formation or disruption of very short period compact
binary systems wherein abrupt velocity and acceleration similar to those given
to RAPs during the short rise fling can be imparted to each orbital partner.
Thus pulsar astrometry from micro- to nano-arsec scales might be of much help.
In case of a supernova, the RAP GW signal could be a benchmark for the GW
signal from the core collapse.


title:
Far-infrared polarimetry from the Stratospheric Observatory for Infrared
  Astronomy

abstract:
  Multi-wavelength imaging polarimetry at far-infrared wavelengths has proven
to be an excellent tool for studying the physical properties of dust, molecular
clouds, and magnetic fields in the interstellar medium. Although these
wavelengths are only observable from airborne or space-based platforms, no
first-generation instrument for the Stratospheric Observatory for Infrared
Astronomy (SOFIA) is presently designed with polarimetric capabilities. We
study several options for upgrading the High-resolution Airborne Wideband
Camera (HAWC) to a sensitive FIR polarimeter. HAWC is a 12 x 32 pixel bolometer
camera designed to cover the 53 - 215 micron spectral range in 4 colors, all at
diffraction-limited resolution (5 - 21 arcsec). Upgrade options include: (1) an
external set of optics which modulates the polarization state of the incoming
radiation before entering the cryostat window; (2) internal polarizing optics;
and (3) a replacement of the current detector array with two state-of-the-art
superconducting bolometer arrays, an upgrade of the HAWC camera as well as
polarimeter. We discuss a range of science studies which will be possible with
these upgrades including magnetic fields in star-forming regions and galaxies
and the wavelength-dependence of polarization.


title: Volumes of Space as Subsystems

abstract:
  As a novel approach with possible relevance to semiclassical gravity, we
propose to define regions of space as quantum subsystems. After recalling how
to divide a generic quantum system into ``parts'', we apply this idea to a free
scalar field in Minkowski space and we compare two different localization
schemes. The first scheme is the standard one, induced by the local
relativistic fields; the alternative scheme that we consider is the one induced
by the Newton-Wigner operators. If degrees of freedom are divided according to
the latter, the Hamiltonian of the field exhibits a certain amount of
non-locality. Moreover, when a region of space is cut off from the rest
according to the Newton-Wigner scheme, the geometric entropy is finite and
exhibits a sensible thermodynamic behaviour.


title: The inverse inertia problem for graphs

abstract:
  Let G be an undirected graph on n vertices and let S(G) be the set of all
real symmetric n x n matrices whose nonzero off-diagonal entries occur in
exactly the positions corresponding to the edges of G. The inverse inertia
problem for G asks which inertias can be attained by a matrix in S(G). We give
a complete answer to this question for trees in terms of a new family of graph
parameters, the maximal disconnection numbers of a graph. We also give a
formula for the inertia set of a graph with a cut vertex in terms of inertia
sets of proper subgraphs. Finally, we give an example of a graph that is not
inertia-balanced, and investigate restrictions on the inertia set of any graph.


title: Ramsey properties of subsets of $\mathbb{N}$

abstract:
  We associate ergodic properties to some subsets of the natural numbers. For
any given family of subsets of the natural numbers one may study the question
of occurrence of certain "algebraic patterns" in every subset in the family. By
"algebraic pattern" we mean a set of solutions of a system of diophantine
equations. In this work we investigate a concrete family of subsets - WM sets.
These sets are characterized by the property that the dynamical systems
associated to such sets are "weakly mixing", and as such they represent a broad
family of randomly constructed subsets of (\mathbb{N}). We find that certain
systems of equations are solvable within every WM set, and our subject is to
learn which systems have this property. We give a complete characterization of
linear diophantine systems which are solvable within every WM set. In addition
we study some non-linear equations and systems of equations with regard to the
question of solvability within every WM set.


title: Non-existence of unbounded Fatou components of a meromorphic function

abstract:
  This paper is devoted to establish sufficient conditions under which a
transcendental meromorphic function has no unbounded Fatou components and to
extend some results for entire functions to meromorphic functions. Actually, we
shall mainly discuss non-existence of unbounded wandering domains of a
meromorphic function. The case for a composition of finitely many meromorphic
function with at least one of them being transcendental can be also
investigated in the argument of this paper.


title:
Suppressing the fragmentation of fragile molecules in helium
  nanodroplets by co-embedding with water: Possible role of the electric dipole
  moment

abstract:
  When fragile molecules such as glycine, polyglicine, alkanes, and
alkanethiols are embedded in liquid helium nanodroplets, electron-impact
ionization of the beam leads to fragmentation which is as extensive as that of
isolated gas-phase molecules. However, it turns out that if a few molecules of
water are co-embedded with the peptide and alkane chains, their fragmentation
is drastically reduced or completely eliminated. On the other hand, the
fragmentation of alkanethiols remains unaffected. On the basis of these
observations, it is proposed that the fragmentation "buffering" effect may
correlate with the magnitude of the impurity's electric dipole moment, which
steers the migration of the ionizing He^+ hole in the droplet.


title: PICO-LON Project for WIMPs search

abstract:
  Highly segmented inorganic crystal has been shown to have good performance
for dark matter search. The energy resolution of ultra thin and large area
NaI(Tl) scintillator has been developed. The estimated sensitivity for
spin-dependent excitation of 127I was discussed. The recent status of low
background measurement at Oto Cosmo Observatory is reported


title: The centers of spin symmetric group algebras and Catalan numbers

abstract:
  Generalizing the work of Farahat-Higman on symmetric groups, we describe the
structures of the even centers Z_n of integral spin symmetric group
superalgebras, which lead to universal algebras termed as the spin FH-algebras.
A connection between the odd Jucys-Murphy elements and the Catalan numbers is
developed and then used to determine the algebra generators of the spin
FH-algebras and of the even centers Z_n.


title:
Variation of Galactic Bar Length with Amplitude and Density as Evidence
  for Bar Growth over a Hubble Time

abstract:
  K_s-band images of 20 barred galaxies show an increase in the peak amplitude
of the normalized m=2 Fourier component with the R_25-normalized radius at this
peak. This implies that longer bars have higher $m=2$ amplitudes. The long bars
also correlate with an increased density in the central parts of the disks, as
measured by the luminosity inside 0.25R_25 divided by the cube of this radius
in kpc. Because denser galaxies evolve faster, these correlations suggest that
bars grow in length and amplitude over a Hubble time with the fastest evolution
occurring in the densest galaxies. All but three of the sample have early-type
flat bars; there is no clear correlation between the correlated quantities and
the Hubble type.


title: Some remarks on the GNS representations of topological $^*$-algebras

abstract:
  After an appropriate restatement of the GNS construction for topological
$^*$-algebras we prove that there exists an isomorphism among the set
$\cycl(A)$ of weakly continuous strongly cyclic $^*$-representations of a
barreled dual-separable $^*$-algebra with unit $A$, the space $\hilb_A(A^*)$ of
the Hilbert spaces that are continuously embedded in $A^*$ and are
$^*$-invariant under the dual left regular action of $A$ and the set of the
corresponding reproducing kernels. We show that these isomorphisms are cone
morphisms and we prove many interesting results that follow from this fact. We
discuss how these results can be used to describe cyclic representations on
more general inner product spaces.


title: Cayley graphs formed by conjugate generating sets of S_n

abstract:
  We investigate subsets of the symmetric group with structure similar to that
of a graph. The trees of these subsets correspond to minimal conjugate
generating sets of the symmetric group. There are two main theorems in this
paper. The first is a characterization of minimal conjugate generating sets of
S_n. The second is a generalization of a result due to Feng characterizing the
automorphism groups of the Cayley graphs formed by certain generating sets
composed of cycles. We compute the full automorphism groups subject to a weak
condition and conjecture that the characterization still holds without the
condition. We also present some computational results in relation to
hamiltonicity of Cayley graphs, including a generalization of the work on
quasi-hamiltonicity by Gutin and Yeo to undirected graphs.


title:
Two elliptic height models with factorized domain wall partition
  functions

abstract:
  We obtain factorized domain wall partition functions in two elliptic height
models: 1. A Felderhof-type model, which is new, and 2. A Perk-Schultz-type
gl(1|1) model of Deguchi and Martin.


title:
Domain wall solitons and Hopf algebraic translational symmetries in
  noncommutative field theories

abstract:
  Domain wall solitons are the simplest topological objects in field theories.
The conventional translational symmetry in a field theory is the generator of a
one-parameter family of domain wall solutions, and induces a massless moduli
field which propagates along a domain wall. We study similar issues in braided
noncommutative field theories possessing Hopf algebraic translational
symmetries. As a concrete example, we discuss a domain wall soliton in the
scalar phi^4 braided noncommutative field theory in Lie-algebraic
noncommutative spacetime, [x^i,x^j]=2i kappa epsilon^{ijk}x_k (i,j,k=1,2,3),
which has a Hopf algebraic translational symmetry. We first discuss the
existence of a domain wall soliton in view of Derrick's theorem, and construct
explicitly a one-parameter family of solutions in perturbation of the
noncommutativity parameter kappa. We then find the massless moduli field which
propagates on the domain wall soliton. We further extend our analysis to the
general Hopf algebraic translational symmetry.


title: Regular representations of the quantum groups at roots of unity

abstract:
  We study the bimodule structure of the quantum function algebra at roots of 1
and prove that it admits an increasing filtration with factors isomorphic to
the tensor products of the dual of Weyl modules $V_\lambda^* \otimes V_{-
\omega_0 \lambda}^*$. As an application we compute the 0-th Hochschild
cohomology of the function algebra at roots of 1.


title: Some algebraic invariants of mixed product ideals

abstract:
  We compute some algebraic invariants (e.g. depth, Castelnuovo - Mumford
regularity) for a special class of monomial ideals, namely the ideals of mixed
products. As a consequence, we characterize the Cohen-Macaulay ideals of mixed
products.


title:
Generalized Clustering Conditions of Jack Polynomials at Negative Jack
  Parameter $\alpha$

abstract:
  We present several conjectures on the behavior and clustering properties of
Jack polynomials at \emph{negative} parameter $\alpha=-\frac{k+1}{r-1}$, of
partitions that violate the $(k,r,N)$ admissibility rule of Feigin \emph{et.
al.} [\onlinecite{feigin2002}]. We find that "highest weight" Jack polynomials
of specific partitions represent the minimum degree polynomials in $N$
variables that vanish when $s$ distinct clusters of $k+1$ particles are formed,
with $s$ and $k$ positive integers. Explicit counting formulas are conjectured.
The generalized clustering conditions are useful in a forthcoming description
of fractional quantum Hall quasiparticles.


title:
Strangeness Production Process $pp \to nK^ + \Sigma ^ +$ within
  Resonance Model

abstract:
  We explore production mechanism and final state interaction in the $pp \to
nK^ + \Sigma ^ +$ channel based on the inconsistent experimental data published
respectively by COSY-11 and COSY-ANKE. The scattering parameter $a> 0$ for
$n\Sigma ^ +$ interaction is favored by large near-threshold cross section
within a nonrelativistic parametrization investigation, and a strong $n\Sigma ^
+$ interaction comparable to $pp$ interaction is also indicated. Based on this
analysis we calculate the contribution from resonance $\Delta ^* (1920)$
through $\pi ^ +$ exchange within resonance model, and the numerical result
suggests a rather small near-threshold total cross section, which is consistent
with the COSY-ANKE data. With an additional sub-threshold resonance $\Delta
^*(1620)$, the model gives a much better description to the rather large
near-threshold total cross section published by COSY-11.


title: Optical Bloch oscillations in periodic structures with metamaterials

abstract:
  We predict that optical Bloch oscillations can be observed in layered
structures with left-handed metamaterials and zero average refractive index
where the layer thickness varies linearly across the structure. We demonstrate
a new type of the Bloch oscillations associated with coupled surface waves
excited at the interfaces between the layers with left-handed material and
conventional dielectric.


title: Two-Photon Exchange in Electron-Proton Elastic Scattering: Theory Update

abstract:
  Recent theoretical developments in the studies of two-photon exchange effects
in elastic electron-proton scattering are reviewed. Two-photon exchange
mechanism is considered a likely source of discrepancy between polarized and
unpolarized experimental measurements of the proton electric form factor at
momentum transfers of several GeV$^2$. This mechanism predicts measurable
effects that are currently studied experimentally.


title: Entangling Power of an Expanding Universe

abstract:
  We show that entanglement can be used to detect spacetime curvature. Quantum
fields in the Minkowski vacuum are entangled with respect to local field modes.
This entanglement can be swapped to spatially separated quantum systems using
standard local couplings. A single, inertial field detector in the
exponentially expanding (de Sitter) vacuum responds as if it were bathed in
thermal radiation in a Minkowski universe. We show that using two inertial
detectors, interactions with the field in the thermal case will entangle
certain detector pairs that would not become entangled in the corresponding de
Sitter case. The two universes can thus be distinguished by their entangling
power.


title: A plane sextic with finite fundamental group

abstract:
  We analyze irreducible plane sextics whose fundamental group factors to
$D_{14}$. We produce explicit equations for all curves and show that, in the
simplest case of the set of singularities $3A_6$, the group is $D_{14}\times
Z_3$.


title:
Playing The Hypothesis Testing Minority Game In The Maximal Reduced
  Strategy Space

abstract:
  Hypothesis Testing Minority Game (HMG) is a variant of the standard Minority
Game (MG) that models the inertial behavior of agents in the market. In the
earlier study of our group, we find that agents cooperate better in HMG than in
the standard MG when strategies are picked from the full strategy space. Here
we continue to study the behavior of HMG when strategies are chosen from the
maximal reduced strategy space. Surprisingly, we find that, unlike the standard
MG, the level of cooperation in HMG depends strongly on the strategy space
used. In addition, a novel intermittency dynamics is also observed in the
minority choice time series in a certain parameter range in which the orderly
phases are characterized by a variety of periodic dynamics. Remarkably, all
these findings can be explained by the crowd-anticrowd theory.


title:
Beauty production in two-photon interactions at LEP2: kt-factorization
  versus data

abstract:
  Inclusive beauty quark production in photon-photon collisions at CERN LEP2 is
considered in the framework of the kt-factorization approach. Both direct and
resolved photon contributions are taken into account. The unintegrated gluon
distributions in a photon are either obtained from the full CCFM evolution
equation or from the Kimber-Martin-Ryskin prescription. The predicted beauty
cross section reasonably agrees with the recent experimental data taken by the
ALEPH collaboration. We argue that theoretical and experimental studies of the
azimuthal correlations in heavy quark production at high energies can serve as
a crucial probe of the unintegrated gluon densities.


title: On irreducible sextics with non-abelian fundamental group

abstract:
  We calculate the fundamental groups $\pi=\pi_1(P^2\setminus B)$ for all
irreducible plane sextics $B\subset\P^2$ with simple singularities for which
$\pi$ is known to admit a dihedral quotient $D_{10}$. All groups found are
shown to be finite, two of them being of large order: 960 and 21600.


title:
The Hot Interstellar Medium in Normal Elliptical Galaxies. II.
  Morphological Evidence for AGN Feedback

abstract:
  We report on the discovery of a new quantitative relationship between X-ray
gas morphology and radio and X-ray AGN luminosities in normal elliptical
galaxies. This is the second paper in a series using data on 54 objects from
the Chandra public archive and builds on the findings of Paper I, which
demonstrated that hydrostatic equilibrium in elliptical galaxies holds, at
best, only approximately and that the shape of the X-ray isophotes is unrelated
to the shape of the gravitational potential. Instead, the gas is almost always
asymmetrically disturbed. In this paper, we quantify the amount of asymmetry
and study its correlation with other galaxy properties. We also determine radio
powers and derive X-ray AGN luminosities for our galaxy sample. We find that
the amount of asymmetry in the gas is correlated with both measures of AGN
activity, in the sense that the hot gas is more disturbed in galaxies with
higher radio and X-ray AGN luminosities. We find no evidence that galaxy
density has significant effects on gas morphology. We do however find evidence
for a correlation between gas asymmetry and the presence of hot ambient gas,
which we interpret as a signature of hydrodynamic interactions with an external
ambient medium. Surprisingly, the AGN-morphology connection persists all the
way down to the weakest AGN luminosities in rather X-ray faint galaxies. This
is strong morphological evidence that supports the general importance of AGN
feedback, even in normal elliptical galaxies.


title:
Robust Global Stabilizability by Means of Sampled-Data Control with
  Positive Sampling Rate

abstract:
  This work proposes a notion of robust reachability of one set from another
set under constant control. This notion is used to construct a control
strategy, involving sequential set-to-set reachability, which guarantees robust
global stabilization of nonlinear sampled data systems with positive sampling
rate. Sufficient conditions for robust reachability of one set from another
under constant control are also provided. Finally, the proposed method is
illustrated through two examples.


title: Operators of the $q$-oscillator

abstract:
  We scrutinize the possibility of extending the result of \cite{ccr} to the
case of q-deformed oscillator for $q$ real; for this we exploit the whole range
of the deformation parameter as much as possible. We split the case into two
depending on whether a solution of the commutation relation is bounded or not.
Our {\it leitmotif} is {\it subnormality}.
  The deformation parameter $q$ is reshaped and this is what makes our approach
effective. The newly arrived parameter, the operator $C$, has two remarkable
properties: it separates in the commutation relation the annihilation and
creation operators from the deformation as well as it $q$-commutes with those
two. This is why introducing the operator $C$ seems to be far-reaching.


title: On the semi-regular module and vertex operator algebras

abstract:
  We prove a conjecture stated in a previous paper by the author about the
existence of canonical filtrations for a family of vertex operator algebras in
rational levels.


title:
Dimensional tuning of electronic states under strong and frustrated
  interactions

abstract:
  We study a model of strongly interacting spinless fermions on an anisotropic
triangular lattice. At half-filling and the limit of strong repulsive
nearest-neighbor interactions, the fermions align in stripes and form an
insulating state. When a particle is doped, it either follows a one-dimensional
free motion along the stripes or fractionalizes perpendicular to the stripes.
The two propagations yield a dimensional tuning of the electronic state. We
study the stability of this phase and derive an effective model to describe the
low-energy excitations. Spectral functions are presented which can be used to
experimentally detect signatures of the charge excitations.


title: Radiative decays of hadronic molecules

abstract:
  It is argued that radiative decays of scalars a0/f0(980) can serve as a
decisive tool in establishing the nature of the latter. In particular,
predictions for the widths of the radiative decays S->gamma V (S=a0/f0(980),
V=omega/rho/gamma) are given in the framework of the molecule model of the
scalars. Finite-range corrections are discussed in detail for the two-gamma
decays of hadronic molecules, with a special attention payed to the interplay
of various scales involved in the problem and to the gauge invariance of the
amplitude. The results are applied to the two-photon decay of the f0(980), and
the existing experimental data on this decay are argued to support the molecule
assignment for the scalar f0(980).