title:
Signatures of integrability in charge and thermal transport in 1D
  quantum systems

abstract:
  Integrable and non-integrable systems have very different transport
properties. In this work, we highlight these differences for specific one
dimensional models of interacting lattice fermions using numerical exact
diagonalization. We calculate the finite temperature adiabatic stiffness (or
Drude weight) and isothermal stiffness (or ``Meissner'' stiffness) in
electrical and thermal transport and also compute the complete momentum and
frequency dependent dynamical conductivities $\sigma(q,\omega)$ and
$\kappa(q,\omega)$. The Meissner stiffness goes to zero rapidly with system
size for both integrable and non-integrable systems. The Drude weight shows
signs of diffusion in the non-integrable system and ballistic behavior in the
integrable system. The dynamical conductivities are also consistent with
ballistic and diffusive behavior in the integrable and non-integrable systems
respectively.


title: Distance to Orion KL Measured with VERA

abstract:
  We present the initial results of multi-epoch VLBI observations of the 22 GHz
H2O masers in the Orion KL region with VERA (VLBI Exploration of Radio
Astrometry). With the VERA dual-beam receiving system, we have carried out
phase-referencing VLBI astrometry and successfully detected an annual parallax
of Orion KL to be 2.29+/-0.10 mas, corresponding to the distance of 437+/-19 pc
from the Sun. The distance to Orion KL is determined for the first time with
the annual parallax method in these observations. Although this value is
consistent with that of the previously reported, 480+/-80 pc, which is
estimated from the statistical parallax method using proper motions and radial
velocities of the H2O maser features, our new results provide the much more
accurate value with an uncertainty of only 4%. In addition to the annual
parallax, we have detected an absolute proper motion of the maser feature,
suggesting an outflow motion powered by the radio source I along with the
systematic motion of source I itself.


title: Precision measurement of the Casimir-Lifshitz force in a fluid

abstract:
  The Casimir force, which results from the confinement of the quantum
mechanical zero-point fluctuations of the electromagnetic fields, has received
significant attention in recent years for its effect on micro- and nano-scale
mechanical systems. With few exceptions, experimental observations have been
limited to conductive bodies interacting separated by vacuum or air. However,
interesting phenomena including repulsive forces are expected to exist in
certain circumstances between metals and dielectrics when the intervening
medium is not vacuum. In order to better understand the effect of the Casimir
force in such situations and to test the robustness of the generalized
Casimir-Lifshitz theory, we have performed the first precision measurements of
the Casimir force between two metals immersed in a fluid. For this situation,
the measured force is attractive and is approximately 80% smaller than the
force predicted by Casimir for ideal metals in vacuum. We present experimental
results and find them to be consistent with Lifshitz's theory.


title: Stability conditions on curves

abstract:
  We study some examples of Bridgeland-Douglas stability conditions on
triangulated categories. From one side we give a complete description of the
stability manifolds for smooth projective curves of positive genus. From the
other side we study stability conditions on triangulated categories generated
by an exceptional collection. In the case of the projective line this leads to
the connectedness and simply-connectedness of the stability manifold.


title: The Cosmology of Modified Gauss-Bonnet Gravity

abstract:
  We consider the cosmology where some function f(G) of the Gauss-Bonnet term G
is added to the gravitational action to account for the late-time accelerating
expansion of the universe. The covariant and gauge invariant perturbation
equations are derived with a method which could also be applied to general
f(R,R^abR_ab,R^abcdR_abcd) gravitational theories. It is pointed out that,
despite their fourth-order character, such f(G) gravity models generally cannot
reproduce arbitrary background cosmic evolutions; for example, the standard
LCDM paradigm with Omega_DE = 0.76 cannot be realized in f(G) gravity theories
unless f is a true cosmological constant because it imposes exclusionary
constraints on the form of f(G). We analyze the perturbation equations and find
that, as in f(R) model, the stability of early-time perturbation growth puts
some constraints on the functional form of f(G), in this case d^2 f/d G^2 < 0.
Furthermore, the stability of small-scale perturbations also requires that f
not deviate significantly from a constant. These analyses are illustrated by
numerically propagating the perturbation equations with a specific model
reproducing a representative LCDM cosmic history. Our results show how the f(G)
models are highly constrained by cosmological data.


title: Dust-Gas Interaction in SNR 1987A

abstract:
  Multiwavelength observations of SNR 1987A show that its morphology is rapidly
changing at X-ray, radio, and optical wavelengths as the blast wave from the
explosion expands into the circumstellar equatorial ring. Infrared emission
arises from the interaction of dust grains with the hot X-ray emitting gas. We
show that the IR emission provides important complementary information on the
interaction of the SN blast wave with the circumstellar equatorial ring that
cannot be obtained at any other wavelength.


title:
The Secular Evolution of a Close Ring-Satellite System: The Excitation
  of Spiral Bending Waves at a Nearby Gap Edge

abstract:
  The secular perturbations exerted by an inclined satellite orbiting in a gap
in a broad planetary ring tends to excite the inclinations of the nearby ring
particles, and the ring's self-gravity can allow that disturbance to propagate
away in the form of a spiral bending wave. The amplitude of this spiral bending
wave is determined, as well as the wavelength, which shrinks as the waves
propagate outwards due to the effects of the central planet's oblateness. The
excitation of these bending waves also damps the satellite's inclination I.
This secular I damping is also compared to the inclination excitation that is
due to the satellite's many other vertical resonances in the ring, and the
condition for inclination damping is determined. The secular I damping is
likely responsible for confining the orbits of Saturn's two known gap-embedded
moons, Pan and Daphnis, to the ring plane.


title:
Extension of the generalised inductive approach to the lace expansion:
  Full proof

abstract:
  This paper extends the inductive approach to the lace expansion of van der
Hofstad and Slade in order to prove Gaussian asymptotic behaviour for models
with critical dimension other than 4. The results are applied by Holmes to
study sufficiently spread-out lattice trees in dimensions d>8 and may also be
applicable to percolation in dimensions d>6.


title:
The Evolution of Dust in the Early Universe with Applications to the
  Galaxy SDSS J1148+5251

abstract:
  Dusty hyperluminous galaxies in the early universe provide unique
environments for studying the role of massive stars in the formation and
destruction of dust. At redshifts above ~ 6, when the universe was less than ~
1 Gyr old, dust could have only condensed in the explosive ejecta of Type II
supernovae (SNe), since most of the progenitors of the AGB stars, the major
alternative source of interstellar dust, did not have time to evolve off the
main sequence since the onset of star formation. In this paper we present
analytical models for the evolution of the gas, dust, and metals in high
redshift galaxies, with a special application to SDSS J1148+5251, a
hyperluminous quasar at z = 6.4. We find that an average supernova must
condense at least 1 Msun of dust to account for the observed dust mass in this
quasar. Observationally, it is in excess of the largest dust yield of ~0.02
Msun found thus far in the ejecta of any SN. If future observations find this
to be a typical supernova dust yield, then additional processes, such as
accretion onto preexisting grains, or condensation around the AGN will need to
be invoked to account for the large amount of dust in this and similar objects.
The galaxy's star formation history is still uncertain, and current
observations of the gas, metal, and dust contents of J1148 can be reproduced by
either an intensive and short burst of star formation (~ 1000 Msun/yr) with a
duration of ~ 100 Myr, or a much lower star formation rate (~ 100 Msun/yr)
occurring over the lifetime of the galaxy.


title:
Spitzer/IRS Imaging and Spectroscopy of the luminous infrared galaxy NGC
  6052 (Mrk 297)

abstract:
  We present photometric and spectroscopic data of the interacting starburst
galaxy NGC 6052 obtained with the Spitzer Space Telescope. The mid-infrared
(MIR) spectra of the three brightest spatially resolved regions in the galaxy
are remarkably similar and are consistent with dust emission from young nearly
coeval stellar populations. Analysis of the brightest infrared region of the
system, which contributes ~18.5 % of the total 16\micron flux, indicates that
unlike similar off-nuclear infrared-bright regions found in Arp 299 or NGC
4038/9, its MIR spectrum is inconsistent with an enshrouded hot dust (T > 300K)
component. Instead, the three brightest MIR regions all display dust continua
of temperatures less than ~ 200K. These low dust temperatures indicate the dust
is likely in the form of a patchy screen of relatively cold material situated
along the line of sight. We also find that emission from polycyclic aromatic
hydrocarbons (PAHs) and the forbidden atomic lines is very similar for each
region. We conclude that the ionization regions are self-similar and come from
young (about 6 Myr) stellar populations. A fourth region, for which we have no
MIR spectra, exhibits MIR emission similar to tidal tail features in other
interacting galaxies.


title:
Deep radio images of the HEGRA and Whipple TeV sources in the Cygnus OB2
  region

abstract:
  Context. The modern generation of Cherenkov telescopes has revealed a new
population of gamma-ray sources in the Galaxy. Some of them have been
identified with previously known X-ray binary systems while other remain
without clear counterparts a lower energies. Our initial goal here was
reporting on extensive radio observations of the first extended and yet
unidentified source, namely TeV J2032+4130. This object was originally detected
by the HEGRA telescope in the direction of the Cygnus OB2 region and its nature
has been a matter of debate during the latest years.
  Aims. We aim to pursue our radio exploration of the TeV J2032+4130 position
that we initiated in a previous paper but taking now into account the latest
results from new Whipple and MILAGRO TeV telescopes.
  Methods. Our investigation is mostly based on interferometric radio
observations with the Giant Metre Wave Radio Telescope (GMRT) close to Pune
(India) and the Very Large Array (VLA) in New Mexico (USA). We also conducted
near infrared observations with the 3.5 m telescope and the OMEGA2000 camera at
the Centro Astronomico Hispano Aleman (CAHA) in Almeria (Spain).
  Results. We present deep radio maps centered on the TeV J2032+4130 position
at different wavelengths. In particular, our 49 and 20 cm maps cover a field of
view larger than half a degree that fully includes the Whipple position and the
peak of MILAGRO emission. Our most important result here is a catalogue of 153
radio sources detected at 49 cm within the GMRT antennae primary beam with a
full width half maximum (FWHM) of 43 arc-minute. Moreover, our
multi-configuration VLA images reveal the non-thermal extended emission
previously reported by us with improved angular resolution.


title: Theoretical status of $B_s$-mixing and lifetimes of heavy hadrons

abstract:
  We review the theoretical status of the lifetime ratios $\tau_{B^+} /
\tau_{B_d}$, $\tau_{B_s} / \tau_{B_d}$, $\tau_{\Lambda_b} / \tau_{B_d}$ and
$\tau_{B_c}$ and of the mixing quantities $\Delta M_s$, $\Delta \Gamma_s$ and
$\phi_s$. $\Delta M_s$ and $\Delta \Gamma_s$ suffer from large uncertainties
due to the badly known decay constants, while the ratio $\Delta \Gamma_s /
\Delta M_s$ can be determined with almost no non-perturbative uncertainties,
therefore it can be used perfectly to find possible new physics contributions
in the mixing parameters. We suggest a very clear method of visualizing the
bounds on new physics and demonstrate this by combining the latest experimental
numbers on the mixing quantities quantities with theory - one already gets some
hints for new physics contributions, but more precise experimental numbers are
needed to draw some definite conclusions. We conclude with a ranking list of
all the discussed quantities according to their current theoretical
uncertainties and point out possible improvements.


title: On implications in sectionally pseudocomplemented posets

abstract:
  A sectionally pseudocomplemented poset P is one which has the top element and
in which every principal order filter is a pseudocomplemented poset. The
sectional pseudocomplements give rise to an implication-like operation on P
which coincides with the relative pseudocomplementation if P is relatively
psudocomplemented. We characterise this operation and study some elementary
properties of upper semilattices, lower semilattices and lattices equipped with
this kind of implication. We deal also with a few weaker versions of
implication. Sectionally pseudocomplemented lattices have already been studied
in the literature.


title: Exclusive e+e-, Di-photon and Di-jet Production at the Tevatron

abstract:
  Results from studies on exclusive production of electron-position pair,
di-photon, and di-jet production at CDF in proton-antiproton collisions at the
Fermilab Tevatron are presented. The first observation and cross section
measurements of exclusive e+e- and di-jet production in hadron-hadron
collisions are emphasized.


title: Coulomb blockade in graphene nanoribbons

abstract:
  We propose that recent transport experiments revealing the existence of an
energy gap in graphene nanoribbons may be understood in terms of Coulomb
blockade. Electron interactions play a decisive role at the quantum dots which
form due to the presence of necks arising from the roughness of the graphene
edge. With the average transmission as the only fitting parameter, our theory
shows good agreement with the experimental data.


title:
A Hypercontractive Inequality for Matrix-Valued Functions with
  Applications to Quantum Computing and LDCs

abstract:
  The Bonami-Beckner hypercontractive inequality is a powerful tool in Fourier
analysis of real-valued functions on the Boolean cube. In this paper we present
a version of this inequality for matrix-valued functions on the Boolean cube.
Its proof is based on a powerful inequality by Ball, Carlen, and Lieb. We also
present a number of applications. First, we analyze maps that encode $n$
classical bits into $m$ qubits, in such a way that each set of $k$ bits can be
recovered with some probability by an appropriate measurement on the quantum
encoding; we show that if $m<0.7 n$, then the success probability is
exponentially small in $k$. This result may be viewed as a direct product
version of Nayak's quantum random access code bound. It in turn implies strong
direct product theorems for the one-way quantum communication complexity of
Disjointness and other problems. Second, we prove that error-correcting codes
that are locally decodable with 2 queries require length exponential in the
length of the encoded string. This gives what is arguably the first
``non-quantum'' proof of a result originally derived by Kerenidis and de Wolf
using quantum information theory, and answers a question by Trevisan.


title:
Pressure-induced changes in the optical properties of
  quasi-one-dimensional $\beta$-Na$_{0.33}$V$_2$O$_5$

abstract:
  The pressure-induced changes in the optical properties of
$\beta$-Na$_{0.33}$V$_2$O$_5$ single crystals at room temperature were studied
by polarization-dependent Raman and far-infrared reflectivity measurements
under high pressure. From the changes in the Raman- and infrared-active phonon
modes in the pressure range 9 - 12 GPa a transfer of charge between the
different V sites can be inferred. The importance of electron-phonon coupling
in the low-pressure regime is discussed.


title:
Parabolic equations with measurable coefficients in $L_p$-spaces with
  mixed norms

abstract:
  The unique solvability of parabolic equations in Sobolev spaces with mixed
norms is presented. The second order coefficients (except $a^{11}$) are assumed
to be only measurable in time and one spatial variable, and VMO in the other
spatial variables. The coefficient $a^{11}$ is measurable in one spatial
variable and VMO in the other variables.


title:
The infrared behavior of Landau gauge Yang-Mills theory in d=2, 3 and 4
  dimensions

abstract:
  We develop a general power counting scheme for the infrared limit of Landau
gauge SU(N) Yang-Mills theory in arbitrary dimensions. Employing a skeleton
expansion, we find that the infrared behavior is qualitatively independent of
the spacetime dimension d. In the cases d=2, 3 and 4 even the quantitative
results for the infrared exponents of the vertices differ only slightly.
Therefore, corresponding lattice simulations provide interesting qualitative
information for the physical case. We furthermore find that the loop integrals
depend only weakly on the numerical values of the IR exponents.


title: Crossed products of locally C*-algebras and Morita equivalence

abstract:
  We introduce the notion of strong Morita equivalence for group actions on
locally C*-algebras and prove that the crossed products associated with two
strongly Morita equivalent continuous inverse limit actions of a locally
compact group G on the locally C*-algebras A and B are strongly Morita
equivalent. This generalizes a result of F. Combes, Proc. London Math. Soc.
49(1984) and R. E. Curto, P.S. Muhly, D. P. Williams, Proc. Amer. Soc.
90(1984).


title: Confinement in N=1 SQCD: One Step Beyond Seiberg's Duality

abstract:
  We consider N=1 supersymmetric quantum chromodynamics (SQCD) with the gauge
group U(N_c) and N_c+N quark flavors. N_c flavors are massless; the
corresponding squark fields develop (small) vacuum expectation values (VEVs) on
the Higgs branch. Extra N flavors are endowed with small (and equal) mass
terms. We study this theory through its Seiberg's dual: U(N) gauge theory with
N_c +N flavors of "dual quark" fields plus a gauge-singlet mesonic field M. The
original theory is referred to as "quark theory" while the dual one is termed
"monopole theory." The suggested mild deformation of Seiberg's procedure
changes the dynamical regime of the monopole theory from infrared free to
asymptotically free at large distances. We show that, upon condensation of the
"dual quarks," the dual theory supports non-Abelian flux tubes (strings).
Seiberg's duality is extended beyond purely massless states to include light
states on both sides. Being interpreted in terms of the quark theory, the
monopole-theory flux tubes are supposed to carry chromoelectric fields. The
string junctions -- confined monopole-theory monopoles -- can be viewed as
"constituent quarks" of the original quark theory. We interpret closed strings
as glueballs of the original quark theory. Moreover, there are string
configurations formed by two junctions connected by a pair of different
non-Abelian strings. These can be considered as constituent quark mesons of the
quark theory.


title: Dynamics of the Teichmueller flow on compact invariant sets

abstract:
  Let Q(S) be the moduli space of area one holomorphic quadratic differentials
for an oriented surface S of genus g with m punctures and 3g-3+m>1. We show
that the supremum over all compact subsets K of Q(S) of the asymptotic growth
rate of the number of periodic orbits of the Teichmueller flow which are
contained in K equals h=6g-6+2m. Moreover, h is also the supremum of the
topological entropies of the restriction of the Teichmueller flow to compact
invariant subsets of Q(S).


title:
Experimental scheme for unambiguous discrimination of linearly
  independent symmetric states

abstract:
  We propose an optimal discrimination scheme for a case of four linearly
independent nonorthogonal symmetric quantum states, based on linear optics
only. The probability of discrimination is in agreement with the optimal
probability for unambiguous discrimination among N symmetric states [Phys.
Lett. A \textbf{250}, 223 (1998)]. The experimental setup can be extended for
the case of discrimination among $2^M$ nonorthogonal symmetric quantum states.


title:
The strongly interacting Quark Gluon Plasma, and the critical behaviour
  of QCD at imaginary chemical potential

abstract:
  We explore the highly non-perturbative hot region of the QCD phase diagram
close to Tc by use of an imaginary chemical potential mu which avoids the sign
problem. The number density and the quark number susceptibility are consistent
with a critical behaviour associated with the transition line in the negative
mu^2 half-plane. We compare the analytic continuation of these results with
various phenomenological models, none of which provides a satisfactory
description of data, a failure on which we make some comments. These results
complement and extend the information obtained via the analysis of the
susceptibilities evaluated at zero mu, yielding a simple description of the
candidate strongly interacting QGP phase. As a byproduct of our analysis we
investigate the Polyakov loop and its hermitian conjugate. Our data offer a
vivid evidence of the importance of the complex nature of the functional
integral measure, which results in L (mu) ne \bar L(mu) for a real chemical
potential.


title:
Measurement of the Atmospheric Muon Charge Ratio at TeV Energies with
  MINOS

abstract:
  The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray
muon data since the beginning of August, 2003 at a depth of 2070
meters-water-equivalent in the Soudan Underground Laboratory, Minnesota, USA.
The data with both forward and reversed magnetic field running configurations
were combined to minimize systematic errors in the determination of the
underground muon charge ratio. When averaged, two independent analyses find the
charge ratio underground to be 1.374 +/- 0.004 (stat.) +0.012 -0.010(sys.).
Using the map of the Soudan rock overburden, the muon momenta as measured
underground were projected to the corresponding values at the surface in the
energy range 1-7 TeV. Within this range of energies at the surface, the MINOS
data are consistent with the charge ratio being energy independent at the two
standard deviation level. When the MINOS results are compared with measurements
at lower energies, a clear rise in the charge ratio in the energy range 0.3 --
1.0 TeV is apparent. A qualitative model shows that the rise is consistent with
an increasing contribution of kaon decays to the muon charge ratio.


title:
Separated cross sections in \pi^0 electroproduction at threshold at Q^2
  = 0.05 GeV^2/c^2

abstract:
  The differential cross sections \sigma_0=\sigma_T+\epsilon \sigma_L,
\sigma_{LT}, and \sigma_{TT} of \pi^0 electroproduction from the proton were
measured from threshold up to an additional center of mass energy of 40 MeV, at
a value of the photon four-momentum transfer of Q^2= 0.05 GeV^2/c^2 and a
center of mass angle of \theta=90^\circ. By an additional out-of-plane
measurement with polarized electrons \sigma_{LT'} was determined. This showed
for the first time the cusp effect above the \pi^+ threshold in the imaginary
part of the s-wave. The predictions of Heavy Baryon Chiral Perturbation Theory
are in disagreement with these data. On the other hand, the data are somewhat
better predicted by the MAID phenomenological model and are in good agreement
with the dynamical model DMT.


title: Non extensive statistic of Tsallis in the heartbeat of healthy humans

abstract:
  It is studied the MIT-BIH Normal Sinus Rhythm Database using a statistical
technique of analysis, that is based on the Wavelet and Hilbert Transforms.
With that technique, it was previously found, that there is a collective and
intrinsic dynamical behavior up to a scale of 64 heartbeats. Now it is shown,
that using the Biorthogonal wavelet bior3.1 such a behavior reaches the scale
1024. That result confirms, that the circulatory system is out of equilibrium.
According to the Statistical Mechanics of Tsallis, and a recent interpretation
of G. Wilk et al. respect to the non extensive parameter q, the healthy human
being is characterized by q=1.70+/-0.01.


title: Field dependent quasiparticles in a strongly correlated local system II

abstract:
  We extend the renormalized quasiparticle description of the symmetric
Anderson model in a magnetic field $H$, developed in earlier work, to the
non-symmetric model. The renormalized parameters are deduced from the low
energy NRG fixed point for arbitrary field values. We find quasiparticle
resonance widths, $\tilde\Delta_\sigma(H)$, which depend in general on the spin
$\sigma$ as well as $H$. The low temperature static properties can be expressed
completely in terms of these parameters, which can also be used as inputs for a
renormalized perturbation theory. We show that taking into account repeated
quasiparticle scattering gives results for the longitudinal and transverse
dynamic spin susceptibilities which are in very good agreement with those
obtained from direct NRG calculations.


title: On Morita equivalence of group actions on locally C*-algebras

abstract:
  We extend to the context of locally C*-algebras a result of F. Combes [Proc.
London Math. Soc. 49(1984), 289-306].


title: Maximizing Maximal Angles for Plane Straight-Line Graphs

abstract:
  Let $G=(S, E)$ be a plane straight-line graph on a finite point set
$S\subset\R^2$ in general position. The incident angles of a vertex $p \in S$
of $G$ are the angles between any two edges of $G$ that appear consecutively in
the circular order of the edges incident to $p$.
  A plane straight-line graph is called $\phi$-open if each vertex has an
incident angle of size at least $\phi$. In this paper we study the following
type of question: What is the maximum angle $\phi$ such that for any finite set
$S\subset\R^2$ of points in general position we can find a graph from a certain
class of graphs on $S$ that is $\phi$-open? In particular, we consider the
classes of triangulations, spanning trees, and paths on $S$ and give tight
bounds in most cases.


title: On pseudo-harmonic maps in conformal geometry

abstract:
  We extend harmonic map techniques to the setting of more general differential
equations in conformal geometry. We obtain an extension of Siu's rigidity to
Kahler-Weyl geometry and apply the latter to Vaisman's conjecture. Other
applications include topological obstructions to the existence of Kahler-Weyl
structures. For example, we show that no co-compact lattice in SO(1,n), n>2,
can be the fundamental group of a compact Kahler-Weyl manifold of certain type.


title: The Cut-off Covering Spectrum

abstract:
  We introduce the $R$ cut-off covering spectrum and the cut-off covering
spectrum of a complete length space or Riemannian manifold. The spectra measure
the sizes of localized holes in the space and are defined using covering spaces
called $\delta$ covers and $R$ cut-off $\delta$ covers. They are investigated
using $\delta$ homotopies which are homotopies via grids whose squares are
mapped into balls of radius $\delta$.
  On locally compact spaces, we prove that these new spectra are subsets of the
closure of the length spectrum. We prove the $R$ cut-off covering spectrum is
almost continuous with respect to the pointed Gromov-Hausdorff convergence of
spaces and that the cut-off covering spectrum is also relatively well behaved.
This is not true of the covering spectrum defined in our earlier work which was
shown to be well behaved on compact spaces. We close by analyzing these spectra
on Riemannian manifolds with lower bounds on their sectional and Ricci
curvature and their limit spaces.


title: A note on toric Deligne-Mumford stacks

abstract:
  We give a new description of the data needed to specify a morphism from a
scheme to a toric Deligne-Mumford stack. The description is given in terms of a
collection of line bundles and sections which satisfy certain conditions. As
applications, we characterize any toric Deligne-Mumford stack as a product of
roots of line bundles over the rigidified stack, describe the torus action,
describe morphisms between toric Deligne-Mumford stacks with complete coarse
moduli spaces in terms of homogeneous polynomials, and compare two different
definitions of toric stacks.


title: Field dependent quasiparticles in the infinite dimensional Hubbard model

abstract:
  We present dynamical mean field theory (DMFT) results for the local spectral
densities of the one- and two-particle response functions for the infinite
dimensional Hubbard model in a magnetic field. We look at the different regimes
corresponding to half-filling, near half-filling and well away from
half-filling, for intermediate and strong values of the local interaction $U$.
The low energy results are analyzed in terms of quasiparticles with field
dependent parameters. The renormalized parameters are determined by two
different methods, both based on numerical renormalization group (NRG)
calculations, and we find good agreement. Away from half-filling the
quasiparticle weights, $z_\sigma(H)$, differ according to the spin type
$\sigma=\uparrow$ or $\sigma=\downarrow$. Using the renormalized parameters, we
show that DMFT-NRG results for the local longitudinal and transverse dynamic
spin susceptibilities in an arbitrary field can be understood in terms of
repeated scattering of these quasiparticles. We also check Luttinger's theorem
for the Hubbard model and find it to be satisfied in all parameter regimes and
for all values of the magnetic field.


title:
Magnetic Phase Diagrams of Multiferroic Hexagonal RMnO3 (R=Er, Yb, Tm,
  and Ho)

abstract:
  The magnetic phase diagrams of RMnO3 (R = Er, Yb, Tm, Ho) are investigated up
to 14 Tesla via magnetic and dielectric measurements. The stability range of
the AFM order below the Neel temperature of the studied RMnO3 extends to far
higher magnetic fields than previously assumed. Magnetic irreversibility
indicating the presence of a spontaneous magnetic moment is found near 50 K for
R=Er, Yb, and Tm. At very low temperatures and low magnetic fields the phase
boundary defined by the ordering of the rare earth moments is resolved. The
sizable dielectric anomalies observed along all phase boundaries are evidence
for strong spin-lattice coupling in the hexagonal RMnO3. In HoMnO3 the strong
magnetoelastic distortions are investigated in more detail via magnetostriction
experiments up to 14 Tesla. The results are discussed based on existing data on
magnetic symmetries and the interactions between the Mn-spins, the rare earth
moments, and the lattice.


title: Notes on Schubert classes of a loop group

abstract:
  In these notes, we survey the homology of the loop group Omega(K) of a
compact group K, also known as the affine Grassmannian of a complex loop group.
Using the Bott picture of H_*(Omega(K)), the homology algebra or Pontryagin
ring, we obtain two new results: A. Factorization of affine Schubert homology
classes. B. Definition of affine Schubert polynomials representing the affine
Schubert homology classes in all types, in terms similar to ordinary Schubert
polynomials.


title: Width and mean curvature flow

abstract:
  Given a Riemannian metric on a homotopy $n$-sphere, sweep it out by a
continuous one-parameter family of closed curves starting and ending at point
curves. Pull the sweepout tight by, in a continuous way, pulling each curve as
tight as possible yet preserving the sweepout. We show:
  Each curve in the tightened sweepout whose length is close to the length of
the longest curve in the sweepout must itself be close to a closed geodesic. In
particular, there are curves in the sweepout that are close to closed
geodesics.
  Finding closed geodesics on the 2-sphere by using sweepouts goes back to
Birkhoff in 1917.
  As an application, we bound from above, by a negative constant, the rate of
change of the width for a one-parameter family of convex hypersurfaces that
flows by mean curvature. The width is loosely speaking up to a constant the
square of the length of the shortest closed curve needed to ``pull over'' $M$.
This estimate is sharp and leads to a sharp estimate for the extinction time;
cf. [CM1], [CM2] where a similar bound for the rate of change for the two
dimensional width is shown for homotopy 3-spheres evolving by the Ricci flow
(see also Perelman).


title: Falling into a black hole

abstract:
  String theory tells us that quantum gravity has a dual description as a field
theory (without gravity). We use the field theory dual to ask what happens to
an object as it falls into the simplest black hole: the 2-charge extremal hole.
In the field theory description the wavefunction of a particle is spread over a
large number of `loops', and the particle has a well-defined position in space
only if it has the same `position' on each loop. For the infalling particle we
find one definition of `same position' on each loop, but there is a different
definition for outgoing particles and no canonical definition in general in the
horizon region. Thus the meaning of `position' becomes ill-defined inside the
horizon.


title:
Matched Filtering of Numerical Relativity Templates of Spinning Binary
  Black Holes

abstract:
  Tremendous progress has been made towards the solution of the
binary-black-hole problem in numerical relativity. The waveforms produced by
numerical relativity will play a role in gravitational wave detection as either
test-beds for analytic template banks or as template banks themselves. As the
parameter space explored by numerical relativity expands, the importance of
quantifying the effect that each parameter has on first the detection of
gravitational waves and then the parameter estimation of their sources
increases. In light of this, we present a study of equal-mass, spinning
binary-black-hole evolutions through matched filtering techniques commonly used
in data analysis. We study how the match between two numerical waveforms varies
with numerical resolution, initial angular momentum of the black holes and the
inclination angle between the source and the detector. This study is limited by
the fact that the spinning black-hole-binaries are oriented axially and the
waveforms only contain approximately two and a half orbits before merger. We
find that for detection purposes, spinning black holes require the inclusion of
the higher harmonics in addition to the dominant mode, a condition that becomes
more important as the black-hole-spins increase. In addition, we conduct a
preliminary investigation of how well a template of fixed spin and inclination
angle can detect target templates of arbitrary spin and inclination for the
axial case considered here.


title:
Bloch's theory in periodic structures with Rashba's spin-orbit
  interaction

abstract:
  We consider a two-dimensional electron gas with Rashba's spin-orbit
interaction and two in-plane potentials superimposed along directions
perpendicular to each other. The first of these potentials is assumed to be a
general periodic potential while the second one is totally arbitrary. A general
form for Bloch's amplitude is found and an eigen-value problem for the band
structure of the system is derived. We apply the general result to the two
particular cases in which either the second potential represents a harmonic
in-plane confinement or it is zero. We find that for a harmonic confinement
regions of the Brillouin zone with high polarizations are associated with the
ones of large group velocity.


title: Relationship between various supersymmetric lattice models

abstract:
  We comment on the relationships between several supersymmetric lattice
models; the ``orbifold lattice theory'' by Cohen-Kaplan-Katz-Unsal (CKKU),
lattice regularization of the topological field theory by Sugino and the
``geometrical approach'' by Catterall. We point out that these three models
have close relationships; the N =(2,2) model by Catterall [Catterall] and the
two-dimensional N = (2,2) lattice theory being similar to Sugino's construction
[Sugino] can be derived by appropriate truncation of fields in the
two-dimensional N = (4,4) orbifold lattice theory by CKKU [Cohen et al].
Catterall's N = (2,2) description possesses extra degrees of freedom compared
to the target N = (2,2) theory. If we remove those extra degrees of freedom in
a way keeping supersymmetry on the lattice, Catterall's description reduces to
a model of the Sugino type.


title: Superstatistics: Theoretical concepts and physical applications

abstract:
  A review of the superstatistics concept is provided, including various recent
applications to complex systems.


title:
The sharp constant in the Hardy-Sobolev-Maz'ya inequality in the three
  dimensional upper half-space

abstract:
  It is shown that the sharp constant in the Hardy-Sobolev-Maz'ya inequality on
the three dimensional upper half space is given by the Sobolev constant. This
is achieved by a duality argument relating the problem to a
Hardy-Littlewood-Sobolev type inequality whose sharp constant is determined as
well.


title: The incidence class and the hierarchy of orbits

abstract:
  R. Rim\'anyi defined the incidence class of two singularities X and Y as
$[X]|_Y$, the restriction of the Thom polynomial of X to Y. He conjectured that
(under mild conditions) the incidence is not zero if and only if Y is in the
closure of X. Generalizing this notion we define the incidence class of two
orbits X and Y of a representation. We give a sufficient condition (positivity)
for Y to have the property that the incidence class $[X]|_Y$ is not zero if and
only if Y is in the closure of X for any other orbit X. We show that for many
interesting cases, e.g. the quiver representations of Dynkin type positivity
holds for all orbits. In other words in these cases the incidence classes
completely determine the hierarchy of the orbits. We also study the case of
singularities where positivity doesn't hold for all orbits.


title: Oscillation Effects and Time Variation of the Supernova Neutrino Signal

abstract:
  The neutrinos detected from the next Galactic core-collapse supernova will
contain valuable information on the internal dynamics of the explosion. One
mechanism leading to a temporal evolution of the neutrino signal is the
variation of the induced neutrino flavor mixing driven by changes in the
density profile. With one and two dimensional hydrodynamical simulations we
identify the behavior and properties of prominent features of the explosion.
Using these results we demonstrate the time variation of the neutrino crossing
probabilities due to changes in the MSW neutrino transformations as the star
explodes by using the S-matrix - Monte Carlo - approach to neutrino
propagation. After adopting spectra for the neutrinos emitted from the
proto-neutron star we calculate for a Galactic supernova the evolution of the
positron spectra within a water Cerenkov detector and the ratio of charged
current to neutral current event rates for a heavy water - SNO like - detector
and find that these detector signals are feasible probes of a number of
explosion features.


title:
Emergence of Cooper pairs, d-wave duality and the phase diagram of
  cuprate superconductors

abstract:
  BCS theory describes the formation of Cooper pairs and their instant "Bose
condensation" into a superconducting state. Helium atoms are preformed bosons
and, in addition to their condensed superfluid state, can also form a quantum
solid, lacking phase-coherence. Here we show that the fate of Cooper pairs can
be more varied than the BCS or helium paradigms. In copper-oxide d-wave
superconductors (dSC) Cooper pairs are intrinsically non-local objects, with
both center-of-mass and relative motions. As doping decreases, the center-of
mass fluctuations force a correlated dSC into a state with enhanced
diamagnetism and robust but short-ranged superconducting order. At extreme
underdoping, the relative fluctuations take over and two pseudogaps --
``small'' (charge) and ``large'' (spin) -- emerge naturally from the theory, as
Cooper pairs ``disintegrate'' and charge ``detaches'' from spin-singlet bonds.
The ensuing ground state(s) are governed by diagonal (mostly antiferromagnetic)
rather than by superconducting (off-diagonal) correlations. The theory is used
to account for several recent experiments and to draw general conclusions about
the phase diagram.


title: A Delicate Universe

abstract:
  We investigate whether explicit models of warped D-brane inflation are
possible in string compactifications. To this end, we study the potential for
D3-brane motion in a warped conifold that includes holomorphically-embedded
D7-branes involved in moduli stabilization. The presence of the D7-branes
significantly modifies the inflaton potential. We construct an example based on
a very simple and symmetric embedding due to Kuperstein, z_1 = constant, in
which it is possible to fine-tune the potential so that slow roll inflation can
occur. The resulting model is rather delicate: inflation occurs in the vicinity
of an inflection point, and the cosmological predictions are extremely
sensitive to the precise shape of the potential.


title:
The private classical capacity with a symmetric side channel and its
  application to quantum cryptography

abstract:
  We study the symmetric-side-channel-assisted private capacity of a quantum
channel, for which we provide a single-letter formula. This capacity is
additive, convex, and, for degradable channels, equal to the unassisted private
capacity. While a channel's (unassisted) capacity for for private classical
communication may be strictly larger than its quantum capacity, we will show
that these capacities are equal for degradable channels, thus demonstrating the
equivalence of privacy and quantum coherence in this context. We use these
ideas to find new bounds on the key rate of quantum key distribution protocols
with one-way classical post-processing. For the Bennett-Brassard-84 (BB84)
protocol, our results demonstrate that collective attacks are strictly stronger
than individual attacks.


title: Some Extensions of Witt's Theorem

abstract:
  We extend Witt's theorem to several kinds of simultaneous isometries of
subspaces. We determine sufficient and necessary conditions for the extension
of an isometry of subspaces $\phi:E\to E'$ to an isometry $\phi_V:V\to V'$ that
also sends a given subspace to another, or a given self-dual flag to another,
or a Witt's decomposition to another and a special self-dual flag to another.
We also determine sufficient and necessary conditions for the isometry of
generic flags or the simultaneous isometry of (subspace, self-dual flag) pairs.


title:
Device-spectroscopy of magnetic field effects in a polyfluorene organic
  light-emitting diode

abstract:
  We perform charge-induced absorption and electroluminescence spectroscopy in
a polyfluorene organic magnetoresistive device. Our experiments allow us to
measure the singlet exciton, triplet exciton and polaron densities in a live
device under an applied magnetic field, and to distinguish between three
different models that were proposed to explain organic magnetoresistance. These
models are based on different spin-dependent interactions, namely exciton
formation, triplet exciton-polaron quenching and bipolaron formation. We show
that the singlet exciton, triplet exciton and polaron densities and
conductivity all increase with increasing magnetic field. Our data are
inconsistent with the exciton formation and triplet-exciton polaron quenching
models.


title: Renormalization Group Evolution in the type I + II seesaw model

abstract:
  We carefully analyze the renormalization group equations in the type I + II
seesaw scenario in the extended standard model (SM) and minimal supersymmetric
standard model (MSSM). Furthermore, we present analytic formulae of the mixing
angles and phases and discuss the RG effect on the different mixing parameters
in the type II seesaw scenario. The renormalization group equations of the
angles have a contribution which is proportional to the mass squared difference
for a hierarchical spectrum. This is in contrast to the inverse proportionality
to the mass squared difference in the effective field theory case.


title: A survey of total positivity

abstract:
  We survey the history of totally positive matrices and the generalization to
Lie groups. We describe a reduction of a bilinear form to a canonical form
(generalizing the case of symplectic nondegenerate forms) using ideas from
total positivity; we also place this in a Lie group context. We give a short
exposition of results of Fock and Goncharov on the study of homomorphisms of
the fundamental group of a closed surface into a Lie group.


title:
Distribution of the very first PopIII stars and their relation to bright
  z~6 quasars

abstract:
  We discuss the link between dark matter halos hosting the first PopIII stars
and the rare, massive, halos that are generally considered to host bright
quasars at high redshift z~6. The main question that we intend to answer is
whether the super-massive black holes powering these QSOs grew out from the
seeds planted by the first intermediate massive black holes created in the
universe. This question involves a dynamical range of 10^13 in mass and we
address it by combining N-body simulations of structure formation to identify
the most massive halos at z~6 with a Monte Carlo method based on linear theory
to obtain the location and formation times of the first light halos within the
whole simulation box. We show that the descendants of the first ~10^6 Msun
virialized halos do not, on average, end up in the most massive halos at z~6,
but rather live in a large variety of environments. The oldest PopIII
progenitors of the most massive halos at z~6, form instead from density peaks
that are on average one and a half standard deviations more common than the
first PopIII star formed in the volume occupied by one bright high-z QSO. The
intermediate mass black hole seeds planted by the very first PopIII stars at
z>40 can easily grow to masses m_BH>10^9.5 Msun by z=6 assuming Eddington
accretion with radiative efficiency \epsilon~0.1. Quenching of the black hole
accretion is therefore crucial to avoid an overabundance of supermassive black
holes at lower redshift. This can be obtained if the mass accretion is limited
to a fraction \eta~6*10^{-3} of the total baryon mass of the halo hosting the
black hole. The resulting high end slope of the black hole mass function at z=6
is \alpha ~ -3.7, a value within the 1\sigma error bar for the bright end slope
of the observed quasar luminosity function at z=6.


title: Radion Phenomenology in Realistic Warped Space Models

abstract:
  We investigate the phenomenology of the Randall-Sundrum radion in realistic
models of electroweak symmetry breaking with bulk gauge and fermion fields,
since the radion may turn out to be the lightest particle in such models. We
calculate the coupling of the radion in such scenarios to bulk fermion and
gauge modes. Special attention needs to be devoted to the coupling to massless
gauge fields (photon, gluon), since it is well known that loop effects may be
important for these fields. We also present a detailed explanation of these
couplings from the CFT interpretation. We then use these couplings to determine
the radion branching fractions and discuss some of the discovery potential of
the LHC for the radion. We find that the gamma-gamma signal is enhanced over
most of the range of the radion mass over the gamma-gamma signal of a SM Higgs,
as long as the RS scale is sufficiently low. However, the signal significance
depends strongly on free parameters that characterize the magnitude of bare
brane-localized kinetic terms for the massless gauge fields. In the absence of
such terms, the signal can be be enhanced over the traditional RS1 models
(where all standard model fields are localized on the IR brane), but the signal
can also be reduced compared to RS1 if the brane localized terms are sizeable.
We also show that for larger radion masses, where the gamma-gamma signal is no
longer significant, one can use the usual 4 lepton signal to discover the
radion.


title: BSSN in Spherical Symmetry

abstract:
  The BSSN (Baumgarte-Shapiro-Shibata-Nakamura) formulation of the Einstein
evolution equations is written in spherical symmetry. These equations can be
used to address a number of technical and conceptual issues in numerical
relativity in the context of a single Schwarzschild black hole. One of the
benefits of spherical symmetry is that the numerical grid points can be tracked
on a Kruskal--Szekeres diagram. Boundary conditions suitable for puncture
evolution of a Schwarzschild black hole are presented. Several results are
shown for puncture evolution using a fourth--order finite difference
implementation of the equations.


title: The SN 1987A Link to Gamma-Ray Bursts

abstract:
  Early measurements of SN 1987A indicate a beam/jet (BJ) which hit polar
ejecta (PE) to produce the "Mystery Spot" (MS). The SN flash takes an extra 8 d
to hit the MS, and this was confirmed at 2e39 ergs/s in the optical at day 8. A
ramp in luminosity starting near day 10 indicates particles from the BJ hitting
the PE, with the fastest particles traveling at 0.8 c, and an upper limit for
the optical luminosity of the MS of 5e40 ergs/s at day 20. The details of SN
1987A strongly suggest that it resulted from a merger of 2 stellar cores of a
common envelope (CE) binary, i.e. a "double-degenerate" (DD)-initiated SN, and
is thus the Rosetta Stone for 99% of MSPs in the non-core-collapsed globular
clusters, GRBs, and SNe, including all recent nearby SNe except SN 1986J and
the more distant SN 2006gy. Without having to blast through the CE of Sk -69
202, it is likely that the BJ would have caused a full, long-soft gamma-ray
burst (lGRB) upon hitting the PE, thus DD can produce lGRBs. The typical 0.5
deg collimation of a GRB, over the 22 lt-d from SN 1987A to its PE, produces
~100 s of delay, MATCHING the observed delay of the non-prompt parts of lGRBs.
Because DD must be the dominant SN mechanism in elliptical galaxies, where only
short, hard GRBs (sGRBs) have been observed, DD without CE or PE must also make
sGRBs, thus the initial photon spectrum of 99% of ALL GRBs is KNOWN, & neutron
star (NS)-NS mergers may not make GRBs as we know them. Observations of Ia's
strongly suggest that these are also DD, implying another systematic effect in
Ia Cosmology, as Ia's will appear to be Ic's when viewed from their DD merger
poles, given sufficient matter above that lost to core- collapse (otherwise it
would just beg the question of what ELSE they could possibly be). There is no
need to invent exotica, such as collapsars or hypernovae, to account for GRBs.


title: Warped Resolved L^{a,b,c} Cones

abstract:
  We construct supergravity solutions describing a stack of D3-branes localized
at a point on a blown-up cycle of a resolved L^{a,b,c} cone. The geometry flows
from AdS_5 x L^{a,b,c} to AdS_5 x S^5/Z_k. The corresponding quiver gauge
theory undergoes an RG flow between two superconformal fixed points, which
leads to semi-infinite chains of flows between the various L^{a,b,c} fixed
points. The general system is described by a triplet of Heun equations which
can each be solved by an expansion with a three-term recursion relation, though
there are closed-form solutions for certain cases. This enables us to read off
the operators which acquire non-zero vacuum expectation values as the quiver
gauge theory flows away from a fixed point.


title:
Statistical Model for Meteorological Elements Based on Local Radiosonde
  Measurements in Mediterranean Region

abstract:
  A comprehensive statistical model is developed for vertical profiles of the
horizontal wind and temperature throughout the troposphere based on
several-years radiosonde measurements of strong winds. The profiles measured
under quite different atmospheric conditions exhibit qualitative similarity. A
proper choice of the reference scales for the wind, temperature and altitude
levels allow us to consider the measurement data as realizations of a random
process with universal characteristics: means, the basic functions and
parameters of standard distributions for transform coefficients of the
Principal Component Analysis. The features of the atmospheric conditions are
described by statistical characteristics of the wind-temperature ensemble of
dimensional reference scales. The model can be useful for air pollution and
safety in high-risk areas such as chemical and nuclear plants.


title:
Interplay of the Rashba and Dresselhaus spin-orbit coupling in the
  optical spin susceptibility of 2D electron systems

abstract:
  We present calculations of the frequency-dependent spin susceptibility tensor
of a two-dimensional electron gas with competing Rashba and Dresselhaus
spin-orbit interaction. It is shown that the interplay between both types of
spin-orbit coupling gives rise to an anisotropic spectral behavior of the spin
density response function which is significantly different from that of
vanishing Rashba or Dresselhaus case. Strong resonances are developed in the
spin susceptibility as a consequence of the angular anisotropy of the energy
spin-splitting. This characteristic optical modulable response may be useful to
experimentally probe spin accumulation and spin density currents in such
systems.


title:
Understanding Quantum Mechanics Through the Complementary Descriptions
  Approach

abstract:
  Niels Bohr introduced the concept of complementarity in order to give a
general account of quantum mechanics, however he stressed that the idea of
complementarity is related to the general dificulty in the formation of human
ideas, inherent in the distinction between subject and object. Earlier, we have
introduced a development of the concept of complementarity which constitutes a
new approach to the interpretation of quantum mechanics. We argue that this
development allows a better understanding of some of the paradigmatic
interpretational problems of quantum theory.
  Within the scheme proposed by modal interpretations we analyze the relation
between holism and reductionism as well as the problems proposed by Arntzenius
and Clifton. We discuss the problem of presupposing the concept of entity
within the quantum formalism and bring into stage the concept of faculty as a
way to recover the objective character of quantum mechanics.


title:
Fast computation by block permanents of cumulative distribution
  functions of order statistics from several populations

abstract:
  The joint cumulative distribution function for order statistics arising from
several different populations is given in terms of the distribution function of
the populations. The computational cost of the formula in the case of two
populations is still exponential in the worst case, but it is a dramatic
improvement compared to the general formula by Bapat and Beg. In the case when
only the joint distribution function of a subset of the order statistics of
fixed size is needed, the complexity is polynomial, for the case of two
populations.


title: A cube of resolutions for knot Floer homology

abstract:
  We develop a skein exact sequence for knot Floer homology, involving singular
knots. This leads to an explicit, algebraic description of knot Floer homology
in terms of a braid projection of the knot.


title: 8.4GHz VLBI observations of SN2004et in NGC6946

abstract:
  We report on 8.4GHz Very Long Baseline Interferometry (VLBI) observations of
the type II-P supernova SN2004et in the spiral galaxy NGC 6946, made on 20
February 2005 (151 days after explosion). The Very Large Array (VLA) flux
density was 1.23$\pm$0.07 mJy, corresponding to an isotropic luminosity at
8.4GHz of (4.45$\pm$0.3)$\times10^{25}$ erg s$^{-1}$ Hz$^{-1}$ and a brightness
temperature of (1.3$\pm$0.3)$\times10^{8}$ K. We also provide an improved
source position, accurate to about 0.5 mas in each coordinate. The VLBI image
shows a clear asymmetry. From model fitting of the size of the radio emission,
we estimate a minimum expansion velocity of 15,700$\pm$2,000 km s$^{-1}$. This
velocity is more than twice the expected mean expansion velocity estimated from
a synchrotron self-absorbed emission model, thus suggesting that synchrotron
self-absorption is not relevant for this supernova. With the benefit of an
optical spectrum obtained 12 days after explosion, we favor an emission model
which consists of two hot spots on an underlying expanding shell of width
comparable to that of SN 1993J.


title: Hadronic Gamma Rays from Supernova Remnants

abstract:
  A gas cloud near a supernova remnant (SNR) provides a target for
pp-collisions leading to subsequent gamma-ray emission through neutral pion
decay. The assumption of a power-law ambient spectrum of accelerated particles
with index near -2 is usually built into models predicting the spectra of
very-high energy (VHE) gamma-ray emission from SNRs. However, if the gas cloud
is located at some distance from the SNR shock, this assumption is not
necessarily correct. In this case, the particles which interact with the cloud
are those leaking from the shock and their spectrum is approximately
monoenergetic with the injection energy gradually decreasing as the SNR ages.
In the GLAST energy range the gamma-ray spectrum resulting from particle
interactions with the gas cloud will be flatter than expected, with the cutoff
defined by the pion momentum distribution in the laboratory frame. We evaluate
the flux of particles escaping from a SNR shock and apply the results to the
VHE diffuse emission detected by the HESS at the Galactic centre.


title: HST/FGS Parallaxes of AM CVn Stars and Astrophysical Consequences

abstract:
  We present absolute parallaxes and relative proper motions for five AM CVn
stars, which we obtained using the Fine Guidance Sensors on board the Hubble
Space Telescope. Our parallax measurements translate into distances d(AM
CVn)=606+135-93 pc, d(HP Lib)=197+14-12 pc, d(CR Boo)=337+44-35 pc, d(V803
Cen)=347+32-27 pc, and d(GP Com)=75+2-2 pc. From these distances we estimate
the space density of AM CVn stars and suggest that previous estimates have been
too high by about an order of magnitude. We also infer the mass accretion rates
which allows us to constrain the masses of the donor stars, and we show that
relatively massive, semi-degenerate donor stars are favored in all systems
except GP Com. Finally, we give updated estimates for their gravitational-wave
signals, relevant for future space missions such as the proposed Laser
Interferometer Space Antenna (LISA), based on their distances and the inferred
masses of the binary components. We show that all systems but GP Com are
excellent candidates for detection with LISA.


title: Gamma-ray albedo of the moon

abstract:
  We use the GEANT4 Monte Carlo framework to calculate the gamma-ray albedo of
the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our
calculation of the albedo spectrum agrees with the EGRET data. We show that the
spectrum of gamma rays from the Moon is very steep with an effective cutoff
around 4 GeV (600 MeV for the inner part of the Moon disc). Apart from other
astrophysical sources, the albedo spectrum of the Moon is well understood,
including its absolute normalisation; this makes it a useful "standard candle"
for gamma-ray telescopes, such as the forthcoming Gamma Ray Large Area Space
Telescope (GLAST). The albedo flux depends on the incident CR spectrum which
changes over the solar cycle. Therefore, it is possible to monitor the CR
spectrum using the albedo gamma-ray flux. Simultaneous measurements of CR
proton and helium spectra by the Payload for Antimatter Matter Exploration and
Light-nuclei Astrophysics (PAMELA), and observations of the albedo gamma rays
by the GLAST Large Area Telescope (LAT), can be used to test the model
predictions and will enable the GLAST LAT to monitor the CR spectrum near the
Earth beyond the lifetime of PAMELA.


title:
Extremal metrics for spectral functions of Dirac operators in even and
  odd dimensions

abstract:
  Let (M^n, g) be a closed smooth Riemannian spin manifold and denote by D its
Atiyah-Singer-Dirac operator. We study the variation of Riemannian metrics for
the zeta function and functional determinant of D^2, and prove finiteness of
the Morse index at stationary metrics, and local extremality at such metrics
under general, i.e. not only conformal, change of metrics.
  In even dimensions, which is also a new case for the conformal Laplacian, the
relevant stability operator is of log-polyhomogeneous pseudodifferential type,
and we prove new results of independent interest, on the spectrum for such
operators. We use this to prove local extremality under variation of the
Riemannian metric, which in the important example when (M^n, g) is the round
n-sphere, gives a partial verification of Branson's conjecture on the pattern
of extremals. Thus det(D^2) has a local (max, max, min, min) when the dimension
is (4k, 4k + 1, 4k + 2, 4k + 3), respectively.


title: Tomographic RF Spectroscopy of a Trapped Fermi Gas at Unitarity

abstract:
  We present spatially resolved radio-frequency spectroscopy of a trapped Fermi
gas with resonant interactions and observe a spectral gap at low temperatures.
The spatial distribution of the spectral response of the trapped gas is
obtained using in situ phase-contrast imaging and 3D image reconstruction. At
the lowest temperature, the homogeneous rf spectrum shows an asymmetric
excitation line shape with a peak at 0.48(4)$\epsilon_F$ with respect to the
free atomic line, where $\epsilon_F$ is the local Fermi energy.


title: Systematics of Soft Particle Production at RHIC: Lessons from PHOBOS

abstract:
  The PHOBOS experiment has measured the properties of particle production in
heavy ion collisions between sqrt(s_NN) of 20 and 200 GeV. The dependencies of
charged particle yield on energy, system size, and both longitudinal and
transverse momentum have been determined over close to the full kinematic
range. Identified charged particles emitted near mid-rapidity have been studied
over about 2 orders of magnitude in transverse momentum. This broad data set
was found to be characterized by a small number of simple scalings which
factorize to a surprising degree. This study has recently been extended by the
addition of new data for Cu+Cu as well as new analyses of Au+Au data, including
more peripheral collisions. In addition, the exploration of global properties
has been expanded with the use of new techniques, including two-particle
correlations, more sensitive searches for rare events, and more detailed
studies of particles emitted at very forward rapidity. The characteristics of
particle production which are revealed by this extensive data set will be
described along with the implications for future data from the LHC.


title:
Indecomposable p-algebras and Galois subfields in generic abelian
  crossed products

abstract:
  Let F be a Henselian valued field with char(F) = p and D a semi-ramified,
"not strongly degenerate" p-algebra. We show that all Galois subfields of D are
inertial. Using this as a tool we study generic abelian crossed product
p-algebras, proving among other things that the noncyclic generic abelian
crossed product p-algebras defined by non-degenerate matrices are
indecomposable p-algebras. To construct examples of these indecomposable
p-algebras with exponent p and large index we study the relationship between
degeneracy in matrices defining abelian crossed products and torsion in CH^2 of
Severi-Brauer varieties.


title:
Distribution of Farey Fractions in Residue Classes and Lang--Trotter
  Conjectures on Average

abstract:
  We prove that the set of Farey fractions of order $T$, that is, the set
$\{\alpha/\beta \in \Q : \gcd(\alpha, \beta) = 1, 1 \le \alpha, \beta \le T\}$,
is uniformly distributed in residue classes modulo a prime $p$ provided $T \ge
p^{1/2 +\eps}$ for any fixed $\eps>0$. We apply this to obtain upper bounds for
the Lang--Trotter conjectures on Frobenius traces and Frobenius fields ``on
average'' over a one-parametric family of elliptic curves.


title: Rational Approximation for Two-Point Boundary value problems

abstract:
  We propose a method for the treatment of two--point boundary value problems
given by nonlinear ordinary differential equations. The approach leads to
sequences of roots of Hankel determinants that converge rapidly towards the
unknown parameter of the problem. We treat several problems of physical
interest: the field equation determining the vortex profile in a
Ginzburg--Landau effective theory, the fixed--point equation for Wilson's exact
renormalization group, a suitably modified Wegner--Houghton's fixed point
equation in the local potential approximation, a Riccati equation, and the
Thomas--Fermi equation. We consider two models where the approach does not
apply in order to show the limitations of our Pad\'{e}--Hankel approach.


title:
Monte Carlo simulations of ${\rm Rb_2MnF_4}$, a classical Heisenberg
  antiferromagnet in two-dimensions with dipolar interaction

abstract:
  We study the phase diagram of a quasi-two dimensional magnetic system ${\rm
Rb_2MnF_4}$ with Monte Carlo simulations of a classical Heisenberg spin
Hamiltonian which includes the dipolar interactions between ${\rm Mn}^{2+}$
spins. Our simulations reveal an Ising-like antiferromagnetic phase at low
magnetic fields and an XY phase at high magnetic fields. The boundary between
Ising and XY phases is analyzed with a recently proposed finite size scaling
technique and found to be consistent with a bicritical point at T=0. We discuss
the computational techniques used to handle the weak dipolar interaction and
the difference between our phase diagram and the experimental results.


title:
Inductively Coupled Circuits with Spin Wave Bus for Information
  Processing

abstract:
  We describe a new approach to logic devices interconnection by the inductive
coupling via a ferromagnetic film. The information among the distant devices is
transmitted in a wireless manner via a magnetic field produced by spin waves
propagating in the ferromagnetic film, referred to as the spin wave bus. As an
alternative approach to the transistor-based architecture, logic circuits with
spin wave bus do not use charge as an information carrier. A bit of information
can be encoded into the phase or the amplitude of the spin wave signal. We
present experimental data demonstrating inductive coupling through the 100nm
thick NiFe and CoFe films at room temperature. The performance of logic
circuits with spin wave bus is illustrated by numerical modeling based on the
experimental data. Potentially, logic circuits with spin wave bus may resolve
the interconnect problem and provide "wireless" read-in and read-out. Another
expected benefit is in the enhanced logic functionality. A set of NOT, AND, and
OR logic gates can be realized in one device structure. The coupling between
the circuits and the spin wave bus can be controlled. We present the results of
numerical simulations showing the controllable switching of a bi-stable logic
cell inductively coupled to the spin wave bus. The shortcomings and limitations
of circuits with spin wave bus are also discussed.


title:
A Chandra archival study of the temperature and metal abundance profiles
  in hot Galaxy Clusters at 0.1 < z < 0.3

abstract:
  We present the analysis of the temperature and metallicity profiles of 12
galaxy clusters in the redshift range 0.1--0.3 selected from the Chandra
archive with at least ~20,000 net ACIS counts and kT>6 keV. We divide the
sample between 7 Cooling-Core (CC) and 5 Non-Cooling-Core (NCC) clusters
according to their central cooling time. We find that single power-laws can
describe properly both the temperature and metallicity profiles at radii larger
than 0.1 r_180 in both CC and NCC systems, showing the NCC objects steeper
profiles outwards. A significant deviation is only present in the inner 0.1
r_180. We perform a comparison of our sample with the De Grandi & Molendi
BeppoSAX sample of local CC and NCC clusters, finding a complete agreement in
the CC cluster profile and a marginally higher value (at ~1sigma) in the inner
regions of the NCC clusters. The slope of the power-law describing kT(r) within
0.1 r_180 correlates strongly with the ratio between the cooling time and the
age of the Universe at the cluster redshift, being the slope >0 and
tau_c/tau_age<=0.6 in CC systems.


title: N=8 non-BPS Attractors, Fixed Scalars and Magic Supergravities

abstract:
  We analyze the Hessian matrix of the black hole potential of N=8, d=4
supergravity, and determine its rank at non-BPS critical points, relating the
resulting spectrum to non-BPS solutions (with non-vanishing central charge) of
N=2, d=4 magic supergravities and their ``mirror'' duals. We find agreement
with the known degeneracy splitting of N=2 non-BPS spectrum of generic special
Kahler geometries with cubic holomorphic prepotential. We also relate non-BPS
critical points with vanishing central charge in N=2 magic supergravities to a
particular reduction of the N=8, 1/8-BPS critical points.


title: Thermoelectric effects in a strongly correlated model for Na$_x$CoO$_2$

abstract:
  Thermal response functions of strongly correlated electron systems are of
appreciable interest to the larger scientific community both theoretically and
technologically. Here we focus on the infinitely correlated t-J model on a
geometrically frustrated two-dimensional triangular lattice.
  Using exact diagonalization on a finite sized system we calculate the
dynamical thermal response functions in order to determine the thermopower,
Lorenz number, and dimensionless figure of merit. The dynamical thermal
response functions is compared to the infinite frequency limit and shown to be
very weak functions of frequency, hence, establishing the validity of the high
frequency formalism recently proposed by Shastry for the thermopower, Lorenz
number, and the dimensionless figure of merit. Further, the thermopower is
demonstrated to have a low to mid temperature enhancement when the sign of the
hopping parameter $t$ is switched from positive to negative for the
geometrically frustrated lattice considered.


title: Discrete Control Systems

abstract:
  Discrete control systems, as considered here, refer to the control theory of
discrete-time Lagrangian or Hamiltonian systems. These discrete-time models are
based on a discrete variational principle, and are part of the broader field of
geometric integration. Geometric integrators are numerical integration methods
that preserve geometric properties of continuous systems, such as conservation
of the symplectic form, momentum, and energy. They also guarantee that the
discrete flow remains on the manifold on which the continuous system evolves,
an important property in the case of rigid-body dynamics.
  In nonlinear control, one typically relies on differential geometric and
dynamical systems techniques to prove properties such as stability,
controllability, and optimality. More generally, the geometric structure of
such systems plays a critical role in the nonlinear analysis of the
corresponding control problems. Despite the critical role of geometry and
mechanics in the analysis of nonlinear control systems, nonlinear control
algorithms have typically been implemented using numerical schemes that ignore
the underlying geometry.
  The field of discrete control system aims to address this deficiency by
restricting the approximation to choice of a discrete-time model, and
developing an associated control theory that does not introduce any additional
approximation. In particular, this involves the construction of a control
theory for discrete-time models based on geometric integrators that yields
numerical implementations of nonlinear and geometric control algorithms that
preserve the crucial underlying geometric structure.


title:
A first-principles model of early evolution: Emergence of gene families,
  species and preferred protein folds

abstract:
  In this work we develop a microscopic physical model of early evolution,
where phenotype,organism life expectancy, is directly related to genotype, the
stability of its proteins in their native conformations which can be determined
exactly in the model. Simulating the model on a computer, we consistently
observe the Big Bang scenario whereby exponential population growth ensues as
soon as favorable sequence-structure combinations (precursors of stable
proteins) are discovered. Upon that, random diversity of the structural space
abruptly collapses into a small set of preferred proteins. We observe that
protein folds remain stable and abundant in the population at time scales much
greater than mutation or organism lifetime, and the distribution of the
lifetimes of dominant folds in a population approximately follows a power law.
The separation of evolutionary time scales between discovery of new folds and
generation of new sequences gives rise to emergence of protein families and
superfamilies whose sizes are power-law distributed, closely matching the same
distributions for real proteins. On the population level we observe emergence
of species, subpopulations which carry similar genomes. Further we present a
simple theory that relates stability of evolving proteins to the sizes of
emerging genomes. Together, these results provide a microscopic first
principles picture of how first gene families developed in the course of early
evolution


title: Metallic AdS/CFT

abstract:
  We use the AdS/CFT correspondence to compute the conductivity of massive N=2
hypermultiplet fields at finite baryon number density in an N=4 SU(N_c)
super-Yang-Mills theory plasma in the large N_c, large 't Hooft coupling limit.
The finite baryon density provides charge carriers analogous to electrons in a
metal. An external electric field then induces a finite current which we
determine directly. Our result for the conductivity is good for all values of
the mass, external field and density, modulo statements about the
yet-incomplete phase diagram. In the appropriate limits it agrees with known
results obtained from analyzing small fluctuations around equilibrium. For
large mass, where we expect a good quasi-particle description, we compute the
drag force on the charge carriers and find that the answer is unchanged from
the zero density case. Our method easily generalizes to a wide class of systems
of probe branes in various backgrounds.


title:
Anomalies and de Sitter radiation from the generic black holes in de
  Sitter spaces

abstract:
  Robinson-Wilczek's recent work shows that, the energy momentum tensor flux
required to cancel gravitational anomaly at the event horizon of a
Schwarzschild-type black hole has an equivalent form to that of a
(1+1)-dimensional blackbody radiation at the Hawking temperature. Motivated by
their work, Hawking radiation from the cosmological horizons of the general
Schwarzschild-de Sitter and Kerr-de Sitter black holes, has been studied by the
method of anomaly cancellation. The result shows that the absorbing gauge
current and energy momentum tensor fluxes required to cancel gauge and
gravitational anomalies at the cosmological horizon are precisely equal to
those of Hawking radiation from it. It should be emphasized that the effective
field theory for generic black holes in de Sitter spaces should be formulated
within the region between the event horizon (EH) and the cosmological horizon
(CH), to integrate out the classically irrelevant ingoing modes at the EH and
the classically irrelevant outgoing modes at the CH, respectively.


title:
In-plane structure and ordering at liquid sodium surfaces and interfaces
  from ab initio molecular dynamics

abstract:
  Atoms at liquid metal surfaces are known to form layers parallel to the
surface. We analyze the two-dimensional arrangement of atoms within such layers
at the surface of liquid sodium, using ab initio molecular dynamics (MD)
simulations based on density functional theory. Nearest neighbor distributions
at the surface indicate mostly 5-fold coordination, though there are noticeable
fractions of 4-fold and 6-fold coordinated atoms. Bond angle distributions
suggest a movement toward the angles corresponding to a six-fold coordinated
hexagonal arrangement of the atoms as the temperature is decreased towards the
solidification point. We rationalize these results with a distorted hexagonal
order at the surface, showing a mixture of regions of five and six-fold
coordination. The liquid surface results are compared with classical MD
simulations of the liquid surface, with similar effects appearing, and with ab
initio MD simulations for a model solid-liquid interface, where a pronounced
shift towards hexagonal ordering is observed as the temperature is lowered.


title: Top Quark Mass Measurements at the Tevatron and the Standard Model Fits

abstract:
  New measurements of the top quark mass from the Tevatron are presented.
Combined with previous results, they yield a preliminary new world average of
Mtop=170.9+-1.1(stat)+-1.5(syst)GeV/c**2 and impose new constraints on the mass
of the Higgs boson.


title: Two Centered Black Holes and N=4 Dyon Spectrum

abstract:
  The exact spectrum of dyons in a class of N=4 supersymmetric string theories
is known to change discontinuously across walls of marginal stability. We show
that the change in the degeneracy across the walls of marginal stability can be
accounted for precisely by the entropy of two centered small black holes which
disappear as we cross the walls of marginal stability.


title:
Correlated photon-pair generation in reverse-proton-exchange PPLN
  waveguides with integrated mode demultiplexer at 10 GHz clock

abstract:
  We report 10-ps correlated photon pair generation in periodically-poled
reverse-proton-exchange lithium niobate waveguides with integrated mode
demultiplexer at a wavelength of 1.5-um and a clock of 10 GHz. Using
superconducting single photon detectors, we observed a coincidence to
accidental count ratio (CAR) as high as 4000. The developed photon-pair source
may find broad application in quantum information systems as well as quantum
entanglement experiments.


title:
New exact solution of Dirac-Coulomb equation with exact boundary
  condition

abstract:
  It usually writes the boundary condition of the wave equation in the Coulomb
field as a rough form without considering the size of the atomic nucleus. The
rough expression brings on that the solutions of the Klein-Gordon equation and
the Dirac equation with the Coulomb potential are divergent at the origin of
the coordinates, also the virtual energies, when the nuclear charges number Z >
137, meaning the original solutions do not satisfy the conditions for
determining solution. Any divergences of the wave functions also imply that the
probability density of the meson or the electron would rapidly increase when
they are closing to the atomic nucleus. What it predicts is not a truth that
the atom in ground state would rapidly collapse to the neutron-like. We
consider that the atomic nucleus has definite radius and write the exact
boundary condition for the hydrogen and hydrogen-like atom, then newly solve
the radial Dirac-Coulomb equation and obtain a new exact solution without any
mathematical and physical difficulties. Unexpectedly, the K value constructed
by Dirac is naturally written in the barrier width or the equivalent radius of
the atomic nucleus in solving the Dirac equation with the exact boundary
condition, and it is independent of the quantum energy. Without any divergent
wave function and the virtual energies, we obtain a new formula of the energy
levels that is different from the Dirac formula of the energy levels in the
Coulomb field.


title: On the closure of the diagonal of a $T_1$-space

abstract:
  Let X be a topological space. The closure of \Delta = {(x, x) : x \in X} in X
\times X is a symmetric relation on X. We characterise those equivalence
relations on an infinite set that arise as the closure of the diagonal with
respect to a T_1-topology.


title: Distributive lattice orderings and Priestley duality

abstract:
  The ordering relation of a bounded distributive lattice L is a (distributive)
(0, 1)-sublattice of L \times L. This construction gives rise to a functor \Phi
from the category of bounded distributive lattices to itself. We examine the
interaction of \Phi with Priestley duality and characterise those bounded
distributive lattices L such that there is a bounded distributive lattice K
such that \Phi(K) is (isomorphic to) L.


title:
Universal characteristics of resonant-tunneling field emission from
  nanostructured surfaces

abstract:
  We have performed theoretical and experimental studies of field emission from
nanostructured semiconductor cathodes. Resonant tunneling through
electric-field-induced interface bound states is found to strongly affect the
field-emission characteristics. Our analytical theory predicts power-law and
Lorentzian-shaped current-voltage curves for resonant-tunneling field emission
from three-dimensional substrates and two-dimensional accumulation layers,
respectively. These predicted line shapes are observed in field emission
characteristics from self-assembled silicon nanostructures. A simple model
describes formation of an accumulation layer and of the resonant level in these
systems.


title:
Fine-structure splitting of exciton states in quantum dot molecules:
  symmetry and tunnel-coupling effects

abstract:
  Exciton levels and fine-structure splitting in laterally-coupled quantum dot
molecules are studied. The electron and hole tunneling energies as well as the
direct Coulomb interaction are essential for the exciton levels. It is found
that fine-structure splitting of the two-lowest exciton levels is contributed
from the intra- and inter-dot exchange interactions, both of which are largely
influenced by the symmetry and tunnel-coupling between the two dots. As the
inter-dot separation is reduced, fine-structure splitting of the exciton ground
state is largely increased while those of the excited states are decreased.
Moreover, the dependence of the fine-structure splitting in quantum dot
molecules on the Coulomb correlation is clearly clarified.


title: Topological structures in Yang Mills Magneto-Fluids

abstract:
  Knotted configurations supported by a Yang Mills fluid-field system are
suggested as a model for glueballs.


title: Viscous Spacetime Fluid and Higher Curvature Gravity

abstract:
  The Einstein field equation as an equation of state of a thermodynamical
system of spacetime is reconsidered in the present Letter. We argue that a
consistent interpretation leads us to identify scalar curvature and
cosmological constant terms representing the bulk viscosity of the spacetime
fluid. Since Einstein equation itself corresponds to a near-equilibrium state
in this interpretation invoking $f(R)$ gravity for nonequilibrium
thermodynamics is not required. A logically consistent generalization to
include the effect of so called 'tidal forces' due to the Riemann curvature is
presented. A new equation of state for higher curvature gravity is derived and
its physical interpretation is discussed.


title:
Comment on "Cyclotron resonance study of the electron and hole velocity
  in graphene monolayers"

abstract:
  In this comment it is pointed out that the electron velocity of the same
order as observed in graphene had been measured in GaAs submicron devices long
ago. Particle- antiparticle asymmetry related with electron and hole effective
masses in graphene seems puzzling as hole in a condensed matter system cannot
be treated as anti-electron. It is argued that there should be a universal
electrodynamics for QHE and superconductivity. In this context attention is
drawn to the new approach based on massless electron and the interpretation
that magnetic field represents angular momentum of the photon fluid.
Measurement of electron velocity in graphene and GaAs in parallel is suggested
for testing the massless electrodynamics.


title:
Inclusive electron spectrum in the region of pion production in
  electron-nucleus scattering and the effect of the quasi-elastic interaction

abstract:
  We have carried out a calculation of the inclusive electron scattering cross
section off oxygen in the kinematical region corresponding to beam energies
between 700 and 1200 MeV, where quasielastic scattering and single pion
production are the dominant reaction mechanisms. The formalism developed and
successfully applied to describe quasielastic scattering has been extended to
include both delta production and non-resonant pion production. The results are
in fairly good agreement with experimental data over the whole range of energy
transfer, including the dip region between the quasielastic peak and the first
resonance.


title:
Catastrophic eruption of magnetic flux rope in the corona and solar wind
  with and without magnetic reconnection

abstract:
  It is generally believed that the magnetic free energy accumulated in the
corona serves as a main energy source for solar explosions such as coronal mass
ejections (CMEs). In the framework of the flux rope catastrophe model for CMEs,
the energy may be abruptly released either by an ideal magnetohydrodynamic
(MHD) catastrophe, which belongs to a global magnetic topological instability
of the system, or by a fast magnetic reconnection across preexisting or
rapidly-developing electric current sheets. Both ways of magnetic energy
release are thought to be important to CME dynamics. To disentangle their
contributions, we construct a flux rope catastrophe model in the corona and
solar wind and compare different cases in which we either prohibit or allow
magnetic reconnection to take place across rapidly-growing current sheets
during the eruption. It is demonstrated that CMEs, even fast ones, can be
produced taking the ideal MHD catastrophe as the only process of magnetic
energy release. Nevertheless, the eruptive speed can be significantly enhanced
after magnetic reconnection sets in. In addition, a smooth transition from slow
to fast eruptions is observed when increasing the strength of the background
magnetic field, simply because in a stronger field there is more free magnetic
energy at the catastrophic point available to be released during an eruption.
This suggests that fast and slow CMEs may have an identical driving mechanism.


title:
Two Energy Release Processes for CMEs: MHD Catastrophe and Magnetic
  Reconnection

abstract:
  It remains an open question how magnetic energy is rapidly released in the
solar corona so as to create solar explosions such as solar flares and coronal
mass ejections (CMEs). Recent studies have confirmed that a system consisting
of a flux rope embedded in a background field exhibits a catastrophic behavior,
and the energy threshold at the catastrophic point may exceed the associated
open field energy. The accumulated free energy in the corona is abruptly
released when the catastrophe takes place, and it probably serves as the main
means of energy release for CMEs at least in the initial phase. Such a release
proceeds via an ideal MHD process in contrast with nonideal ones such as
magnetic reconnection. The catastrophe results in a sudden formation of
electric current sheets, which naturally provide proper sites for fast magnetic
reconnection. The reconnection may be identified with a solar flare associated
with the CME on one hand, and produces a further acceleration of the CME on the
other. On this basis, several preliminary suggestions are made for future
observational investigations, especially with the proposed KuaFu satellites, on
the roles of the MHD catastrophe and magnetic reconnection in the magnetic
energy release associated with CMEs and flares.


title:
Higgs boson production at the LHC: transverse-momentum resummation and
  rapidity dependence

abstract:
  We consider Higgs boson production by gluon fusion in hadron collisions. We
study the doubly-differential transverse-momentum (q_T) and rapidity (y)
distribution of the Higgs boson in perturbative QCD. In the region of small q_T
(q_T << M_H, M_H being the mass of the Higgs boson), we include the effect of
logarithmically-enhanced contributions due to multiparton radiation to all
perturbative orders. We use the impact parameter and double Mellin moments to
implement and factorize the multiparton kinematics constraint of transverse-
and longitudinal-momentum conservation. The logarithmic terms are then
systematically resummed in exponential form. At small q_T, we perform the
all-order resummation of large logarithms up to next-to-next-to-leading
logarithmic accuracy, while at large q_T (q_T ~ M_H), we apply a matching
procedure that recovers the fixed-order perturbation theory up to
next-to-leading order. We present quantitative results for the differential
cross section in q_T and y at the LHC, and we comment on the comparison with
the q_T cross section integrated over y.


title: Symbolic Reachability Analysis of Higher-Order Context-Free Processes

abstract:
  We consider the problem of symbolic reachability analysis of higher-order
context-free processes. These models are generalizations of the context-free
processes (also called BPA processes) where each process manipulates a data
structure which can be seen as a nested stack of stacks. Our main result is
that, for any higher-order context-free process, the set of all predecessors of
a given regular set of configurations is regular and effectively constructible.
This result generalizes the analogous result which is known for level 1
context-free processes. We show that this result holds also in the case of
backward reachability analysis under a regular constraint on configurations. As
a corollary, we obtain a symbolic model checking algorithm for the temporal
logic E(U,X) with regular atomic predicates, i.e., the fragment of CTL
restricted to the EU and EX modalities.


title: Ten Year Review of Queue Scheduling of the Hobby-Eberly Telescope

abstract:
  This paper presents a summary of the first 10 years of operating the
Hobby-Eberly Telescope (HET) in queue mode. The scheduling can be quite complex
but has worked effectively for obtaining the most science possible with this
uniquely designed telescope. The queue must handle dozens of separate
scientific programs, the involvement of a number of institutions with
individual Telescope Allocation Committees as well as engineering and
instrument commissioning. We have continuously revised our queue operations as
we have learned from experience. The flexibility of the queue and the
simultaneous availability of three instruments, along with a staff trained for
all aspects of telescope and instrumentation operation, have allowed optimum
use to be made of variable weather conditions and have proven to be especially
effective at accommodating targets of opportunity and engineering tasks. In
this paper we review the methodology of the HET queue along with its strengths
and weaknesses.


title: Phase transition in compressible Ising systems at fixed volume

abstract:
  Using a Ginzburg-Landau model, we study the phase transition behavior of
compressible Ising systems at constant volume by varying the temperature $T$
and the applied magnetic field $h$. We show that two phases can coexist
macroscopically in equilibrium within a closed region in the $T$-$h$ plane. It
occurence is favored near tricriticality. We find a field-induced critical
point, where the correlation length diverges, the difference of the coexisting
two phases and the surface tension vanish, but the isothermal magnetic
susceptibility does not diverge in the mean field theory. We also investigate
phase ordering numerically.


title: Renormalization flow for unrooted forests on a triangular lattice

abstract:
  We compute in small temperature expansion the two-loop renormalization
constants and the three-loop coefficient of the beta-function, that is the
first non-universal term, for the sigma-model with O(N) invariance on the
triangular lattice at N=-1. The partition function of the corresponding
Grassmann theory is, for negative temperature, the generating function of
unrooted forests on such a lattice, where the temperature acts as a chemical
potential for the number of trees in the forest. To evaluate Feynman diagrams
we extend the coordinate space method to the triangular lattice.


title: Spin foam model from canonical quantization

abstract:
  We suggest a modification of the Barrett-Crane spin foam model of
4-dimensional Lorentzian general relativity motivated by the canonical
quantization. The starting point is Lorentz covariant loop quantum gravity. Its
kinematical Hilbert space is found as a space of the so-called projected spin
networks. These spin networks are identified with the boundary states of a spin
foam model and provide a generalization of the unique Barrette-Crane
intertwiner. We propose a way to modify the Barrett-Crane quantization
procedure to arrive at this generalization: the B field (bi-vectors) should be
promoted not to generators of the gauge algebra, but to their certain
projection. The modification is also justified by the canonical analysis of
Plebanski formulation. Finally, we compare our construction with other
proposals to modify the Barret-Crane model.


title: Complexified Dynamical Systems

abstract:
  Many dynamical systems, such as the Lotka-Volterra predator-prey model and
the Euler equations for the free rotation of a rigid body, are PT symmetric.
The standard and well-known real solutions to such dynamical systems constitute
an infinitessimal subclass of the full set of complex solutions. This paper
examines a subset of the complex solutions that contains the real solutions,
namely, those having PT symmetry. The condition of PT symmetry selects out
complex solutions that are periodic.


title: Is Thick Brane Model Consistent with the Recent Observations?

abstract:
  There exist many observational evidences implying the expansion of our
universe is undergoing a late-time acceleration, the mechanism of this
acceleration is yet unknown. In the so-called thick brane model this phenomena
is attributed to the thickness of the brane along the extra dimension. In this
study we mainly rely to the consistency of this model with most recent
observational data related to the background evolution. The new Supernova Type
Ia (SNIa) Gold sample and Supernova Legacy Survey (SNLS) data, the position of
the acoustic peak at the last scattering surface from the WMAP observations and
the baryon acoustic oscillation peak found in the Sloan Digital Sky Survey
(SDSS) are used to constrain the free parameter of the thick codimension 1
brane model. To infer its consistency with age of our universe, we compare the
age of old cosmological objects with what computed using the best fit values
for the model parameters. When the universe is matter dominated, $w=0$, at 68%
level of confidence, the combination of Gold sample SNIa, CMB shift parameter
and SDSS databases provides $\Omega_m=0.31_{-0.02}^{+0.02}$,
$\Omega_{\cal{C}}=0.05_{-0.01}^{+0.01}$, $w_r=-1.40_{-0.20}^{+0.20}$, hence a
spatially open universe with $\Omega_k=0.21_{-0.08}^{+0.08}$. The same
combination with SNLS supernova observation gives
$\Omega_m=0.28_{-0.02}^{+0.03}$, $\Omega_{\cal{C}}=0.037_{-0.004}^{+0.003}$,
$w_r=-2.05_{-0.15}^{+0.15}$ consequently provides a spatially open universe
$\Omega_k=0.11_{-0.07}^{+0.10}$. These results obviously seem to be in
contradiction with the most recent WMAP results indicating a flat universe.


title: Towards Understanding the Origin of Genetic Languages

abstract:
  Molecular biology is a nanotechnology that works--it has worked for billions
of years and in an amazing variety of circumstances. At its core is a system
for acquiring, processing and communicating information that is universal, from
viruses and bacteria to human beings. Advances in genetics and experience in
designing computers have taken us to a stage where we can understand the
optimisation principles at the root of this system, from the availability of
basic building blocks to the execution of tasks. The languages of DNA and
proteins are argued to be the optimal solutions to the information processing
tasks they carry out. The analysis also suggests simpler predecessors to these
languages, and provides fascinating clues about their origin. Obviously, a
comprehensive unraveling of the puzzle of life would have a lot to say about
what we may design or convert ourselves into.

categories: q-bio.GN cs.IT math.IT physics.bio-ph quant-ph


title: Hydrogen adsorption on boron doped graphene: an {\it ab initio} study

abstract:
  The electronic and structural properties of (i) boron doped graphene sheets,
and (ii) the chemisorption processes of hydrogen adatoms on the boron doped
graphene sheets have been examined by {\it ab initio} total energy
calculations.


title: A remark on quantum gravity

abstract:
  We discuss the structure of Dyson--Schwinger equations in quantum gravity and
conclude in particular that all relevant skeletons are of first order in the
loop number. There is an accompanying sub Hopf algebra on gravity amplitudes
equivalent to identities between n-graviton scattering amplitudes which
generalize the Slavnov Taylor identities. These identities map the infinite
number of charges and finite numbers of skeletons in gravity to an infinite
number of skeletons and a finite number of charges needing renormalization. Our
analysis suggests that gravity, regarded as a probability conserving but
perturbatively non-renormalizable theory, is renormalizable after all, thanks
to the structure of its Dyson--Schwinger equations.