title: Q-manifolds and Mackenzie theory: an overview

abstract:
  This text is meant to be a brief overview of the topics announced in the
title and is based on my talk in Vienna (August/September 2007). It does not
contain new results (except probably for a remark concerning Q-manifold
homology, which I wish to elaborate elsewhere).
  "Mackenzie theory" stands for the rich circle of notions that have been put
forward by Kirill Mackenzie (solo or in collaboration): double structures such
as double Lie groupoids and double Lie algebroids, Lie bialgebroids and their
doubles, nontrivial dualities for double and multiple vector bundles, etc.
"Q-manifolds" are (super)manifolds with a homological vector field, i.e., a
self-commuting odd vector field. They may have an extra Z-grading (called
weight) not necessarily linked with the Z_2-grading (parity). I discuss double
Lie algebroids (discovered by Mackenzie) and explain how this quite complicated
fundamental notion is equivalent to a very simple one if the language of
Q-manifolds is used. In particular, it shows how the two seemingly different
notions of a "Drinfeld double" of a Lie bialgebroid due to Mackenzie and
Roytenberg respectively, turn out to be the same thing if properly understood.


abstract:
  VERITAS, the Very Energetic Radiation Imaging Telescope Array System, is an
array of four 12 m diameter imaging atmospheric Cherenkov telescopes for
gamma-ray astronomy above 100 GeV currently in operation in Arizona. The
VERITAS Collaboration has developed VEGAS, the VERITAS Gamma-ray Analysis
Suite, a data-analysis software package for the processing of single- and
multiple-telescope data produced by the array. The package consists of a core
of six stages as well as visualisation and diagnostic components. It has been
developed in C++ using modern objected-oriented design patterns to be highly
flexible, configurable and extendable. VEGAS utilises CERN's ROOT data-analysis
framework and runs on Linux and Mac OS X systems. The architecture and
structure of the VEGAS package will be described in detail while the data
analysis algorithms are described in additional papers.


title: Cosmological bounds on oscillating dark energy models

abstract:
  We study some cosmological constraints on the two phenomenological models of
oscillating dark energy. In these scenarios, the equation of state of dark
energy varies periodically and may provide a way to unify the early
acceleration (inflation) and the late time acceleration of the universe. These
models give also an effective way to tackle the so-called cosmic coincidence
problem. We examine observational constraints on this class of models from the
latest observational data including the \emph{gold} sample of 182 type Ia
supernovae, the CMB shift parameter $R$ and the BAO measurements from the Sloan
Digital Sky Survey.


title: Extended matter coupled to BF theory

abstract:
  Recently, a topological field theory of membrane-matter coupled to BF theory
in arbitrary spacetime dimensions was proposed [1]. In this paper, we discuss
various aspects of the four-dimensional theory. Firstly, we study classical
solutions leading to an interpretation of the theory in terms of strings
propagating on a flat spacetime. We also show that the general classical
solutions of the theory are in one-to-one correspondence with solutions of
Einstein's equations in the presence of distributional matter (cosmic strings).
Secondly, we quantize the theory and present, in particular, a prescription to
regularize the physical inner product of the canonical theory. We show how the
resulting transition amplitudes are dual to evaluations of Feynman diagrams
coupled to three-dimensional quantum gravity. Finally, we remove the regulator
by proving the topological invariance of the transition amplitudes.


title: HST search for M subdwarf binaries

abstract:
  We present HST/ACS observations of 19 nearby M subdwarfs in a search for
binary systems. Other than the wide common proper motion pair LHS 2140/2139,
none of our sdM and esdM targets are found to be binaries. Our survey is
sensitive to equal-luminosity companions at close (2-8 AU) separations, while
sub-stellar secondaries could have been detected at separations in the range of
6-30 AU. To check for wide binaries, we have compared the POSS I and II images
in a field of view as large as 10'x10', but could not detect a single co-moving
star for any of the targets. Combining our results with those from Gizis &
Reid, we have a binary fraction of 3% (1/28). Detection of a small number of M
subdwarf binaries reported in the literature suggests a higher fraction than
the one obtained here, probably comparable to that found for the more massive
solar-type stars in the halo (13-15%). Comparison with the disk M dwarf
fraction (25%) however suggests multiplicity to be rare among the lowest mass
halo stars, implying the two populations formed under different initial
conditions. The low binary fraction in our survey could be explained by
selection biases. A decrease in multiplicity has been observed in the disk for
masses below 0.1Msun, the peak in the disk mass function (MF). The globular
cluster MF is found to peak at about 0.33Msun, with a decrease in the number of
stars per unit mass below the peak mass. Our sample being composed of stars
with masses between ~0.2 and 0.085 Msun suggests that a decrease in
multiplicity similar to the disk may also be true for the halo stars, but
perhaps below a mass of ~0.3Msun. A higher M subdwarf binary fraction may be
obtained if the selected primaries have masses near or higher than the peak in
the MF.


title: Type Ia Supernova: Burning and Detonation in the Distributed Regime

abstract:
  A simple, semi-analytic representation is developed for nuclear burning in
Type Ia supernovae in the special case where turbulent eddies completely
disrupt the flame. The speed and width of the ``distributed'' flame front are
derived. For the conditions considered, the burning front can be considered as
a turbulent flame brush composed of corrugated sheets of well-mixed flames.
These flames are assumed to have a quasi-steady-state structure similar to the
laminar flame structure, but controlled by turbulent diffusion. Detonations
cannot appear in the system as long as distributed flames are still
quasi-steady-state, but this condition is violated when the distributed flame
width becomes comparable to the size of largest turbulent eddies. When this
happens, a transition to detonation may occur. For current best estimates of
the turbulent energy, the most likely density for the transition to detonation
is in the range 0.5 - 1.5 x 10^7 g cm^{-3}.


title: Generic local distinguishability and completely entangled subspaces

abstract:
  A subspace of a multipartite Hilbert space is completely entangled if it
contains no product states. Such subspaces can be large with a known maximum
size, S, approaching the full dimension of the system, D. We show that almost
all subspaces with dimension less than or equal to S are completely entangled,
and then use this fact to prove that n random pure quantum states are
unambiguously locally distinguishable if and only if n does not exceed D-S.
This condition holds for almost all sets of states of all multipartite systems,
and reveals something surprising. The criterion is identical for separable and
for nonseparable states: entanglement makes no difference.


title: An introduction to the geometry of metric spaces

abstract:
  These informal notes deal with some basic properties of metric spaces,
especially concerning lengths of curves.


title: The Impact of Carbon Enhancement on Extra Mixing in Metal-Poor Stars

abstract:
  We critically examine the constraints imposed by carbon-enhanced metal-poor
(CEMP) stars on the mixing mechanisms that operate in red giants. CEMP stars
are created when the surface layers of a metal-poor dwarf are enriched with
He-burning products via mass transfer from an evolved donor. The difference
between main sequence (MS) and red giant CEMP abundances can be used as a
diagnostic of the timescale for the mixing of the processed material into
stellar interiors on the MS. Abundance trends with luminosity among red giant
CEMP stars test theories of canonical extra mixing for low mass giants with a
high bulk metallicity. We find a significant dilution in CN enrichment in giant
CEMP stars relative to their MS precursors, and take this as evidence that
thermohaline mixing induced by mean molecular weight inversions is ineffective
in CEMP stars. This contradicts models that rely on efficient thermohaline
mixing induced by small mu gradients in red giants, because such models would
predict that MS CEMP stars with large mu inversions would be homogenized on a
very short timescale. The data do not rule out slower MS thermohaline mixing
comparable to previously published estimates. We also find that canonical extra
mixing is strongly suppressed in CEMP giants relative to stars with the same
iron abundance. A likely cause is the shift in the location of non-equilibrium
CN processing relative to the steep mu gradient in the hydrogen burning shell,
which also occurs in solar metallicity RGB stars. Implications for the mass
accreted by CEMP stars and the mechanism for canonical extra mixing are
discussed.


title: Permutahedra and generalized associahedra

abstract:
  Given a finite Coxeter system $(W,S)$ and a Coxeter element $c$, we construct
a simple polytope whose outer normal fan is N. Reading's Cambrian fan $F_c$,
settling a conjecture of Reading that this is possible. We call this polytope
the $c$-generalized associahedron. Our approach generalizes Loday's realization
of the associahedron (a type $A$ $c$-generalized associahedron whose outer
normal fan is not the cluster fan but a coarsening of the Coxeter fan arising
from the Tamari lattice) to any finite Coxeter group. A crucial role in the
construction is played by the $c$-singleton cones, the cones in the
$c$-Cambrian fan which consist of a single maximal cone from the Coxeter fan.
  Moreover, if $W$ is a Weyl group and the vertices of the permutahedron are
chosen in a lattice associated to $W$, then we show that our realizations have
integer coordinates in this lattice.


title:
Rational Expectations, psychology and inductive learning via moving
  thresholds

abstract:
  This work suggests modifications to a previously introduced class of
heterogeneous agent models that allow for the inclusion of different types of
agent motivations and behaviours in a unified way. The agents operate within a
highly simplified environment where they are only able to be long or short one
unit of the asset. The price of the asset is influenced by both an external
information stream and the demand of the agents. The current strategy of each
agent is defined by a pair of moving thresholds straddling the current price.
When the price crosses either of the thresholds for a particular agent, that
agent switches position and a new pair of thresholds is generated.
  Different kinds of threshold motion correspond to different sources of
motivation, running the gamut from purely rational information-processing,
through rational (but often undesirable) behaviour induced by perverse
incentives and moral hazards, to purely psychological effects. As with the
previous class of models, the fact that the simplest model of this kind
precisely conforms to the Efficient Market Hypothesis allows causal
relationships to be established between properties at the agent level and
violations of EMH price statistics at the global level.


title:
Direct and inverse theorems in the theory of approximation by the Ritz
  method

abstract:
  For an arbitrary self-adjoint operator $B$ in a Hilbert space $H$, we present
direct and inverse theorems establishing the relationship between the degree of
smoothness of a vector $x \in H$ with respect to the operator $B$, the rate of
convergence to zero of its best approximation by exponential-type entire
vectors of the operator $B$, and the $k$-modulus of continuity of the vector
$x$ with respect to the operator $B$. The results are used for finding a priori
estimates for the Ritz approximate solutions of operator equations in a Hilbert
space.


title:
Superconducting d-wave stripes in cuprates: Valence bond order
  coexisting with nodal quasiparticles

abstract:
  We point out that unidirectional bond-centered charge-density-wave states in
cuprates involve electronic order in both s- and d-wave channels, with
non-local Coulomb repulsion suppressing the s-wave component. The resulting
bond-charge-density wave, coexisting with superconductivity, is compatible with
recent photoemission and tunneling data and as well as neutron-scattering
measurements, once long-range order is destroyed by slow fluctuations or glassy
disorder. In particular, the real-space structure of d-wave stripes is
consistent with the scanning-tunneling-microscopy measurements on both
underdoped Bi2Sr2CaCu2O8+x and Ca2-xNaxCuO2Cl2 of Kohsaka et al. [Science 315,
1380 (2007), arXiv:cond-mat/0703309].


title:
Minimal conductivity in graphene: interaction corrections and
  ultraviolet anomaly

abstract:
  Conductivity of a disorder-free intrinsic graphene is studied to the first
order in the long-range Coulomb interaction and is found to be
\sigma=\sigma_0(1+0.01 g), where 'g' is the dimensionless ("fine structure")
coupling constant. The calculations are performed using three different
methods: i) electron polarization function, ii) Kubo formula for the
conductivity, iii) quantum transport equation. Surprisingly, these methods
yield different results unless a proper ultraviolet cut-off procedure is
implemented, which requires that the interaction potential in the effective
Dirac Hamiltonian is cut-off at small distances (large momenta).


title: Spin-orbital effects in magnetized quantum wires and spin chains

abstract:
  We present analysis of the interacting quantum wire problem in the presence
of magnetic field and spin-orbital interaction. We show that an interesting
interplay of Zeeman and spin-orbit terms, facilitated by the electron-electron
interaction, results in the spin-density wave (SDW) state when the magnetic
field and spin-orbit axes are orthogonal. We show that this instability is
enhanced in a closely related problem of Heisenberg spin chain with asymmetric
uniform Dzyaloshinskii-Moriya (DM) interaction. Magnetic field in the direction
perpendicular to the DM anisotropy axis results in staggered long-range
magnetic order along the orthogonal to the applied field direction. We explore
consequences of the uniform DM interaction for the electron spin resonance
(ESR) measurements, and point out that they provide way to probe right- and
left-moving excitations of the spin chain separately.


title:
Modeling the Infrared Bow Shock at delta Velorum: Implications for
  Studies of Debris Disks and lambda Bootis Stars

abstract:
  We have discovered a bow shock shaped mid-infrared excess region in front of
delta Velorum using 24 micron observations obtained with the Multiband Imaging
Photometer for Spitzer (MIPS). The excess has been classified as a debris disk
from previous infrared observations. Although the bow shock morphology was only
detected in the 24 micron observations, its excess was also resolved at 70
micron. We show that the stellar heating of an ambient interstellar medium
(ISM) cloud can produce the measured flux. Since delta Velorum was classified
as a debris disk star previously, our discovery may call into question the same
classification of other stars. We model the interaction of the star and ISM,
producing images that show the same geometry and surface brightness as is
observed. The modeled ISM is 15 times overdense relative to the average Local
Bubble value, which is surprising considering the close proximity (24 pc) of
delta Velorum.
  The abundance anomalies of lambda Bootis stars have been previously explained
as arising from the same type of interaction of stars with the ISM. Low
resolution optical spectra of delta Velorum show that it does not belong to
this stellar class. The star therefore is an interesting testbed for the ISM
accretion theory of the lambda Bootis phenomenon.


title:
The SINFONI MgII Program for Line Emitters (SIMPLE): Discovering
  starbursts near QSO sight-lines

abstract:
  Low-ionization transitions such as the MgII 2796/2803 doublet trace cold gas
in the vicinity of galaxies. It is not clear whether this gas is part of the
interstellar medium of large proto-disks, part of dwarfs, or part of entrained
material in supernovae-driven outflows. Studies based on MgII statistics, e.g.
stacked images and clustering analysis, have invoked starburst-driven outflows
where MgII absorbers are tracing the denser and colder gas of the outflow. A
consequence of the outflow scenario is that the strongest absorbers ought to be
associated with starbursts. We use the near-IR integral field spectrograph
SINFONI to test whether starbursts are found around z~1 MgII absorbers. For 67%
(14 out of 21) of the absorbers with rest-frame equivalent width larger than 2
AA, we do detect Ha in emission within 200 km/s of the predicted wavelength
based on the \MgII redshift.
  The star-formation rate (SFR) inferred from Halpha ranges from 1 to 20
Msun/yr, i.e. showing a level of star-formation larger than in M82 by a factor
of >4 on average. Our flux limit (3-sigma) corresponds to a SFR of 0.5 Msun/yr.
We find evidence (at >95% confidence) for a correlation between SFR and
equivalent width, indicating a physical connection between starburst phenomena
and gas seen in absorption. In the cases where we can extract the velocity
field, the host-galaxies reside in halos with mean mass <log M_h>=11.2 in good
agreement with clustering measurements.


title:
HI Imaging Observations of Superthin Galaxies. II. IC2233 and the Blue
  Compact Dwarf NGC2537

abstract:
  We have used the VLA to image the HI 21-cm line emission in the edge-on Sd
galaxy IC2233 and the blue compact dwarf NGC2537. We also present new optical
B,R, and H alpha imaging of IC2233 obtained with the WIYN telescope. Despite
evidence of localized massive star formation, IC2233 has a low surface
brightness disk with a low global star formation rate (~0.05 M_sun/yr), and no
significant 21-cm radio continuum emission. The HI and ionized gas disks of
IC2233 are clumpy and vertically distended, with scale heights comparable to
the young stars. Both the stellar and HI disks of IC2233 appear flared, and we
also find a vertically extended, rotationally anomalous HI component extending
to z~2.4 kpc. The HI disk exhibits a mild lopsidedness as well as a global
corrugation pattern with a period of ~7 kpc and an amplitude of ~150 pc. To our
knowledge, this is the first time corrugations of the gas disk have been
reported in an external galaxy; these undulations may be linked to bending
instabilities or to underlying spiral structure and suggest that the disk is
largely self-gravitating.
  Lying at a projected distance of 16.7' from IC2233, NGC2537 has an HI disk
with a bright, tilted inner ring and a flocculent, dynamically cold outer
region that extends to ~3.5D_25. Although NGC2537 is rotationally-dominated, it
shows significant turbulence near its center. The inner rotation curve rises
steeply, implying a strong central mass concentration. Our data indicate that
IC2233 and NGC2537 do not constitute a bound pair and most likely lie at
different distances. We also find no compelling evidence of a recent minor
merger in either galaxy, suggesting that both are examples of small disk
galaxies evolving in relative isolation. (Abridged)


title: The origin of star formation since z=1

abstract:
  The use of multiple integral field units with FLAMES/GIRAFFE at VLT has
revolutionized investigations of distant galaxy kinematics. This facility may
recover the velocity fields of almost all emission line galaxies with
I_(AB)<22.5 at z<0.8. We have gathered a unique sample of 63 velocity fields at
z=0.4-0.75, which are representative of M_stellar > 1.5*10^10 M_sun emission
line W_0([OII])>15 \AA galaxies, and are unaffected by cosmic variance. Taking
into account all galaxies -with or without emission lines- in that redshift
range, we find that 42+/-7% of them have anomalous kinematics, including
26+/-7% with complex kinematics, i.e. not supported by either rotation or by
dispersion. The large fraction of complex velocity fields suggests a large
impact of merging in shaping the galaxies in the intermediate mass range. We
discuss how this can be accommodated within the frame of current scenarios of
galaxy formation, including for the Milky Way and M31.


title: Bulk viscosity in 2SC and CFL quark matter

abstract:
  The bulk viscosities of two color-superconducting phases, the color-flavor
locked (CFL) phase and the 2SC phase, are computed and compared to the result
for unpaired quark matter. In the case of the CFL phase, processes involving
kaons and the superfluid mode give the largest contribution to the bulk
viscosity since all fermionic modes are gapped. In the case of the 2SC phase,
ungapped fermionic modes are present and the process u+d <-> u+s provides the
dominant contribution. In both cases, the bulk viscosity can become larger than
that of the unpaired phase for sufficiently large temperatures (T >~ 1 MeV for
CFL, T >~ 0.1 MeV for 2SC). Bulk viscosity (as well as shear viscosity) is
important for the damping of r-modes in compact stars and thus can potentially
be used as an indirect signal for the presence or absence of
color-superconducting quark matter.


title:
Global Models for the Evolution of Embedded, Accreting Protostellar
  Disks

abstract:
  Most analytic work to date on protostellar disks has focused on those in
isolation from their environments. However, observations are now beginning to
probe the earliest, most embedded phases of star formation, during which disks
are rapidly accreting from their parent cores and cannot be modeled in
isolation. We present a simple, one-zone model of protostellar accretion disks
with high mass infall rates. Our model combines a self-consistent calculation
of disk temperatures with an approximate treatment of angular momentum
transport via two mechanisms. We use this model to survey the properties of
protostellar disks across a wide range of stellar masses and evolutionary
times, and make predictions for disks' masses, sizes, spiral structure, and
fragmentation that will be directly testable by future large-scale surveys of
deeply embedded disks. We define a dimensionless accretion-rotation parameter
which, in conjunction with the disk's temperature, controls the disk evolution.
We track the dominant mode of angular momentum transport, and demonstrate that
for stars with final masses greater than roughly one solar mass, gravitational
instabilities are the most important mechanism as most of the mass accumulates.
We predict that binary formation through disk fission, fragmentation of the
disk into small objects, and spiral arm strength all increase in importance to
higher stellar masses.


title: Finitistic dimension through infinite projective dimension

abstract:
  We show that an artin algebra having at most three radical layers of infinite
projective dimension has finite finitistic dimension, generalizing the known
result for algebras with vanishing radical cube.


title: Measurement of the muon charge asymmetry from W boson decays

abstract:
  We present a measurement of the muon charge asymmetry from W boson decays
using 0.3 fb^{-1} of data collected at \sqrt{s}=1.96 GeV between 2002 and 2004
with the D0 detector at the Fermilab Tevatron ppbar Collider. We compare our
findings with expectations from next-to-leading-order calculations performed
using the CTEQ6.1M and MRST04 NLO parton distribution functions. Our findings
can be used to constrain future parton distribution function fits.


title: Arithmetic duality theorems for 1-motives over function fields

abstract:
  In this paper we obtain a Poitou-Tate exact sequence for finite and flat
group schemes over a global function field. We also extend the duality theorems
for 1-motives over number fields obtained by D.Harari and T.Szamuely to the
function field case.


title:
Comment on ``Elastic Stabilization of a Single-Domain Ferroelectric
  State in Nanoscale Capacitors and Tunnel Junctions" [N.A. Pertsev and H.
  Kohlstedt, Phys. Rev. Lett. 98, 257603 (2007).]

abstract:
  In a recent Letter [N.A. Pertsev and H. Kohlstedt, Phys. Rev. Lett. 98,
257603 (2007)] the authors claim that "even nanoscale capacitors and tunnel
junctions may have out of plane polarization sufficient for memory
applications." Here we show in an elementary way that this conclusion is not
substantiated by their calculations and that they should have come to the
opposite conclusion within their approximations.


title:
Thermodynamical Analogy Between BTZ Black Holes and Effective String
  Theory

abstract:
  In this paper we study the first law of thermodynamics for the (2+1)
dimensional BTZ rotating black hole considering a pair of thermodinamical
systems constructed with the two horizons of this solution. We show that these
two systems are similar to the right and left movers of string theory and that
the temperature associated with the black hole is the harmonic mean of the
temperatures associated with these two systems.


title:
Fractional statistics of topological defects in graphene and related
  structures

abstract:
  We show that fractional charges bound to topological defects in the recently
proposed time-reversal-invariant models on honeycomb and square lattices obey
fractional statistics. The effective low-energy description is given in terms
of a `doubled' level-2 Chern-Simons field theory, which is parity and
time-reversal invariant and implies two species of semions (particles with
statistical angle pi/2) labeled by a new emergent quantum number that we
identify as the fermion axial charge.


title: Unravelling Strings at the LHC

abstract:
  We construct LHC signature footprints for four semi-realistic string/$M$
theory vacua with an MSSM visible sector. We find that they all give rise to
limited regions in LHC signature space, and are qualitatively different from
each other for understandable reasons. We also propose a technique in which
correlations of LHC signatures can be effectively used to distinguish among
these string theory vacua. We expect the technique to be useful for more
general string vacua. We argue that further systematic analysis with this
approach will allow LHC data to disfavor or exclude major ``corners'' of
string/$M$ theory and favor others. The technique can be used with limited
integrated luminosity and improved.


title:
Geometric resonance cooling of polarizable particles in an optical
  waveguide

abstract:
  In the radiation field of an optical waveguide, the Rayleigh scattering of
photons is shown to result in a strongly velocity-dependent force on atoms. The
pump field, which is injected in the fundamental branch of the waveguide, is
favorably scattered by a moving atom into one of the transversely excited
branches of propagating modes. All fields involved are far detuned from any
resonances of the atom. For a simple polarizable particle, a linear friction
force coefficient comparable to that of cavity cooling can be achieved.


title: Overview of the New Horizons Science Payload

abstract:
  The New Horizons mission was launched on 2006 January 19, and the spacecraft
is heading for a flyby encounter with the Pluto system in the summer of 2015.
The challenges associated with sending a spacecraft to Pluto in less than 10
years and performing an ambitious suite of scientific investigations at such
large heliocentric distances (> 32 AU) are formidable and required the
development of lightweight, low power, and highly sensitive instruments. This
paper provides an overview of the New Horizons science payload, which is
comprised of seven instruments. Alice provides spatially resolved ultraviolet
spectroscopy. The Ralph instrument has two components: the Multicolor Visible
Imaging Camera (MVIC), which performs panchromatic and color imaging, and the
Linear Etalon Imaging Spectral Array (LEISA), which provides near-infrared
spectroscopic mapping capabilities. The Radio Experiment (REX) is a component
of the New Horizons telecommunications system that provides both occultation
and radiometry capabilities. The Long Range Reconnaissance Imager (LORRI)
provides high sensitivity, high spatial resolution optical imaging
capabilities. The Solar Wind at Pluto (SWAP) instrument measures the density
and speed of solar wind particles. The Pluto Energetic Particle Spectrometer
Science Investigation (PEPSSI) measures energetic protons and CNO ions. The
Venetia Burney Student Dust Counter (VB-SDC) is used to record dust particle
impacts during the cruise phases of the mission.


title: Nonperturbative Instability of AdS_5 x S^5/Z_k

abstract:
  We study the AdS/CFT correspondence with boundary conditions AdS_5 x S^5/Z_k,
where the Z_k acts freely but breaks all supersymmetry. While there are closed
string tachyons at small 't Hooft coupling, there are no tachyons at large
coupling. Nevertheless, we show that there is a nonperturbative instability
directly analogous to the decay of the Kaluza-Klein vacuum. We discuss the
implications of this instability for the strongly coupled dual field theory,
and compare with earlier studies of this theory at weak coupling.


title: On Cobweb posets tiling problem

abstract:
  Kwasniewski's cobweb posets uniquely represented by directed acyclic graphs
are such a generalization of the Fibonacci tree that allows joint combinatorial
interpretation for all of them under admissibility condition. This
interpretation was derived in the source papers and it entailes natural
enquieres already formulated therein. In our note we response to one of those
problems. This is a tiling problem. Our observations on tiling problem include
proofs of tiling's existence for some cobweb-admissible sequences. We show also
that not all cobwebs admit tiling as defined below.


title:
Quantum trajectory approach to circuit QED: Quantum jumps and the Zeno
  effect

abstract:
  We present a theoretical study of a superconducting charge qubit dispersively
coupled to a transmission line resonator. Starting from a master equation
description of this coupled system and using a polaron transformation, we
obtain an exact effective master equation for the qubit. We then use quantum
trajectory theory to investigate the measurement of the qubit by continuous
homodyne measurement of the resonator out-field. Using the same porlaron
transformation, a stochastic master equation for the conditional state of the
qubit is obtained. From this result, various definitions of the measurement
time are studied. Furthermore, we find that in the limit of strong homodyne
measurement, typical quantum trajectories for the qubit exhibit a crossover
from diffusive to jump-like behavior. Finally, in the presence of Rabi drive on
the qubit, the qubit dynamics is shown to exhibit quantum Zeno behavior.


title:
Multi-symmetry and Multi-band Superconductivity in Filled-skutterudites
  PrOs$_4$Sb$_{12}$ and PrRu$_4$Sb$_{12}$

abstract:
  Thermal conductivity measurements were performed on single crystal samples of
the superconducting filled skutterudite compounds PrOs$_4$Sb$_{12}$ and
PrRu$_4$Sb$_{12}$ both as a function of temperature and magnetic field applied
perpendicular to the heat current. In zero magnetic field, the low temperature
electronic thermal conductivity of PrRu$_4$Sb$_{12}$ is vanishingly small,
consistent with a fully-gapped Fermi surface. For PrOs$_4$Sb$_{12}$, however,
we find clear evidence for residual electronic conduction as the temperature
tends to zero Kelvin which is consistent with the presence of nodes in the
superconducting energy gap. The field dependence of the electronic conductivity
for both compounds shows a rapid rise immediately above H$_{c1}$ and
significant structure over the entire vortex state. In the fully gapped
superconductor PrRu$_4$Sb$_{12}$, this is interpreted in terms of multi-band
effects. In PrOs$_4$Sb$_{12}$, we consider the Doppler shift of nodal
quasiparticles at low fields and multiband effects at higher fields.


title: Ontological models and the interpretation of contextuality

abstract:
  Studying the extent to which realism is compatible with quantum mechanics
teaches us something about the quantum mechanical universe, regardless of the
validity of such realistic assumptions. It has also recently been appreciated
that these kinds of studies are fruitful for questions relating to quantum
information and computation. Motivated by this, we extend the ontological model
formalism for realistic theories to describe a set of theories emphasizing the
role of measurement and preparation devices by introducing `hidden variables'
to describe them. We illustrate both the ontological model formalism and our
generalization of it through a series of example models taken from the
literature. Our extension of the formalism allows us to quantitatively analyze
the meaning contextuality (a constraint on successful realistic theories),
finding that - taken at face-value - it can be realized as a natural
interaction between the configurations of a system and measurement device.
However, we also describe a property that we call deficiency, which follows
from contextuality, but does not admit such a natural interpretation. Loosely
speaking, deficiency breaks a symmetry between preparations and measurements in
quantum mechanics. It is the property that the set of ontic states which a
system prepared in quantum state psi may actually be in, is strictly smaller
than the set of ontic states which would reveal the measurement outcome psi
with certainty.


title:
Doping Dependence of Vortex Regimes in
  Y$_{1-x}$Pr$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-\delta}$ Single Crystals

abstract:
  Magnetic relaxation measurements on a series of
Y$_{1-x}$Pr$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-\delta}$ ($x = 0.13, 0.34, 0.47$) single
crystals were performed over a large field and temperature range in order to
investigate the characteristics of the vortex matter across the second
magnetization peak (SMP). The magnitude of the SMP varies non-monotonically
with the Pr concentration; i.e., the irreversible magnetization normalized by
its value at the onset field $H_{on}$ displays a maximum for the $x = 0.34$
single crystal. The two characteristic fields, $H_{on}$ and $H_{sp}$, follow
different temperature $T$ dependences: $H_{on} \propto T^{\nu_{on}}$ and
$H_{sp} \propto [1-(T/T_{c})^{2}]^{\nu_{sp}}$. The extracted values of the
apparent activation energy $U^\ast$ and the creep exponent $\mu$ display a
maximum at a field $H_{on} < H^\ast < H_{sp}$. Their field dependences point
toward the coexistence of both elastic and plastic creep for $H > H_{on}$. The
degree of participation of each creep mechanism is determined by the charge
carrier density, which controls both the elastic properties of the vortex
matter and the pinning potential.


title:
Coherence lifetimes of excitations in an atomic condensate due to the
  thin spectrum

abstract:
  We study the quantum coherence properties of a finite sized atomic condensate
using a toy-model and the thin spectrum model formalism. The decoherence time
for a condensate in the ground state, nominally taken as a variational symmetry
breaking state, is investigated for both zero and finite temperatures. We also
consider the lifetimes for Bogoliubov quasi-particle excitations, and contrast
them to the observability window determined by the ground state coherence time.
The lifetimes are shown to exhibit a general characteristic dependence on the
temperature, determined by the thin spectrum accompanying the spontaneous
symmetry breaking ground state.


title: Electroweak Model Without A Higgs Particle

abstract:
  An electroweak model is formulated in a finite, four-dimensional quantum
field theory without a Higgs particle. The W and Z masses are induced from the
electroweak symmetry breaking of one-loop vacuum polarization graphs. The
theory contains only the observed particle spectrum of the standard model. In
terms of the observed twelve lepton and quark masses, a loop calculation of the
non-local electroweak energy scale $\Lambda_W$ and $\rho$ predicts the values
$\Lambda_W(M_Z)=541$ GeV and $\rho(M_Z)=0.993$, yielding
$s^2_Z\equiv\sin^2\theta_W(M_Z)=0.21686\pm 0.00097$. Possible ways to detect a
non-local signal in scattering amplitudes involving loop graphs at the LHC are
discussed. Fermion masses are generated from a ``mass gap'' equation obtained
from the lowest order, finite fermion self-energy with a broken symmetry vacuum
state. The cross section for $W_L^+ W_L^-\to W_L^+ W_L^-$ is predicted to
vanish for $\sqrt{s} > {1 \rm TeV}$, avoiding a violation of the unitarity
bound. The Brookhaven National Laboratory measurement of the anomalous magnetic
moment of the muon and the residual difference between the measured value and
the standard model can provide a test of a non-local deviation from the
standard model.


title: New Horizons: Anticipated Scientific Investigations at the Pluto System

abstract:
  The New Horizons spacecraft will achieve a wide range of measurement
objectives at the Pluto system, including color and panchromatic maps,
1.25-2.50 micron spectral images for studying surface compositions, and
measurements of Pluto's atmosphere (temperatures, composition, hazes, and the
escape rate). Additional measurement objectives include topography, surface
temperatures, and the solar wind interaction. The fulfillment of these
measurement objectives will broaden our understanding of the Pluto system, such
as the origin of the Pluto system, the processes operating on the surface, the
volatile transport cycle, and the energetics and chemistry of the atmosphere.
The mission, payload, and strawman observing sequences have been designed to
acheive the NASA-specified measurement objectives and maximize the science
return. The planned observations at the Pluto system will extend our knowledge
of other objects formed by giant impact (such as the Earth-moon), other objects
formed in the outer solar system (such as comets and other icy dwarf planets),
other bodies with surfaces in vapor-pressure equilibrium (such as Triton and
Mars), and other bodies with N2:CH4 atmospheres (such as Titan, Triton, and the
early Earth).


title: A New 3D Potential-Density Basis Set

abstract:
  A set of bi-orthogonal potential-density basis functions is introduced to
model the density and its associated gravitational field of three dimensional
stellar systems. Radial components of our basis functions are weighted integral
forms of spherical Bessel functions. We discuss the properties of our basis
functions and demonstrate their shapes for the latitudinal Fourier number
$l=2$.


title:
Radio Detection of Supernova 2004ip in the Circumnuclear Region of the
  Luminous Infrared Galaxy IRAS 18293-3413

abstract:
  We report a radio detection of supernova SN 2004ip in the circumnuclear
region of the luminous infrared galaxy IRAS 18293-3413, using Very Large Array
(VLA) observations at 8.4 GHz on 11 June 2007. SN 2004ip had been previously
discovered at near-infrared wavelengths using adaptive optics observations, but
its nature (core-collapse or thermonuclear) could not be definitely
established. Our radio detection, about three years after the explosion of the
supernova, indicates a prominent interaction of the ejecta of SN 2004ip with
the circumstellar medium, confirming that the supernova was a core-collapse
event (probably Type II), and thus strongly suggesting that its progenitor was
a massive star with a significant mass-loss prior to its explosion. SN 2004ip
has a 8.4 GHz luminosity of 3.5E27 erg/s/Hz, about twice as bright as SN 2000ft
in NGC 7469 at a similar age, and given its projected distance to the nucleus
(~500 pc), is one of the closest of all known radio SNe to a galaxy nucleus,
and one of the brightest radio SNe ever.


title: Set Matrices and The Path/Cycle Problem

abstract:
  Presentation of set matrices and demonstration of their efficiency as a tool
using the path/cycle problem.


title:
Extreme gravitational lensing in vicinity of Schwarzschild-de Sitter
  black holes

abstract:
  We have developed a realistic, fully general relativistic computer code to
simulate optical projection in a strong, spherically symmetric gravitational
field. The standard theoretical analysis of optical projection for an observer
in the vicinity of a Schwarzschild black hole is extended to black hole
spacetimes with a repulsive cosmological constant, i.e, Schwarzschild-de Sitter
spacetimes. Influence of the cosmological constant is investigated for static
observers and observers radially free-falling from the static radius.
Simulations include effects of the gravitational lensing, multiple images,
Doppler and gravitational frequency shift, as well as the intensity
amplification. The code generates images of the sky for the static observer and
a movie simulations of the changing sky for the radially free-falling observer.
Techniques of parallel programming are applied to get a high performance and a
fast run of the BHC simulation code.


title: Ullemar's formula for the moment map, II

abstract:
  We establish the complex analogue of Ullemar's formula for polynomial
domains. We show that the Jacobian of the complex moment mapping is equal to
the self-resultant of the defining polynomial.


title: The Integrability of Pauli System in Lorentz Violating Background

abstract:
  We systematically analyze the integrability of a Pauli system in Lorentz
violating background at the non-relativistic level both in two- and
three-dimensions. We consider the non-relativistic limit of the Dirac equation
from the QED sector of the so-called Standard Model Extension by keeping only
two types of background couplings, the vector a_mu and the axial vector b_mu.
We show that the spin-orbit interaction comes as a higher order correction in
the non-relativistic limit of the Dirac equation. Such an interaction allows
the inclusion of spin degree non-trivially, and if Lorentz violating terms are
allowed, they might be comparable under special circumstances. By including all
possible first-order derivative terms and considering the cases a\ne 0, b\ne 0,
and b_0\ne 0 one at a time, we determine the possible forms of constants of
motion operator, and discuss the existence or continuity of integrability due
to Lorentz violating background.


title: Geometric Transitions and Dynamical SUSY Breaking

abstract:
  We show that the physics of D-brane theories that exhibit dynamical SUSY
breaking due to stringy instanton effects is well captured by geometric
transitions, which recast the non-perturbative superpotential as a classical
flux superpotential. This allows for simple engineering of Fayet, Polonyi,
O'Raifeartaigh, and other canonical models of supersymmetry breaking in which
an exponentially small scale of breaking can be understood either as coming
from stringy instantons or as arising from the classical dynamics of fluxes.


title: Long-Range Reconnaissance Imager on New Horizons

abstract:
  The LOng-Range Reconnaissance Imager (LORRI) is the high resolution imaging
instrument for the New Horizons mission to Pluto, its giant satellite Charon,
its small moons Nix and Hydra, and the Kuiper Belt, which is the vast region of
icy bodies extending roughly from Neptune's orbit out to 50 astronomical units
(AU). New Horizons launched on January 19, 2006 as the inaugural mission in
NASA's New Frontiers program. LORRI is a narrow angle (field of view=0.29 deg),
high resolution (4.95 microrad pixels), Ritchey-Chretien telescope with a 20.8
cm diameter primary mirror, a focal length of 263 cm, and a three lens
field-flattening assembly. A 1024 x 1024 pixel (optically active region),
thinned, backside-illuminated charge-coupled device (CCD) detector is used in
the focal plane unit and is operated in frame transfer mode. LORRI provides
panchromatic imaging over a bandpass that extends approximately from 350 nm to
850 nm. LORRI operates in an extreme thermal environment, situated inside the
warm spacecraft with a large, open aperture viewing cold space. LORRI has a
silicon carbide optical system, designed to maintain focus over the operating
temperature range without a focus adjustment mechanism. Moreover, the
spacecraft is thruster-stabilized without reaction wheels, placing stringent
limits on the available exposure time and the optical throughput needed to
satisfy the measurement requirements.


title:
ALICE: The Ultraviolet Imaging Spectrograph aboard the New Horizons
  Pluto-Kuiper Belt Mission

abstract:
  The New Horizons ALICE instrument is a lightweight (4.4 kg), low-power (4.4
Watt) imaging spectrograph aboard the New Horizons mission to Pluto/Charon and
the Kuiper Belt. Its primary job is to determine the relative abundances of
various species in Pluto's atmosphere. ALICE will also be used to search for an
atmosphere around Pluto's moon, Charon, as well as the Kuiper Belt Objects
(KBOs) that New Horizons hopes to fly by after Pluto-Charon, and it will make
UV surface reflectivity measurements of all of these bodies as well. The
instrument incorporates an off-axis telescope feeding a Rowland-circle
spectrograph with a 520-1870 angstroms spectral passband, a spectral point
spread function of 3-6 angstroms FWHM, and an instantaneous spatial
field-of-view that is 6 degrees long. Different input apertures that feed the
telescope allow for both airglow and solar occultation observations during the
mission. The focal plane detector is an imaging microchannel plate (MCP) double
delay-line detector with dual solar-blind opaque photocathodes (KBr and CsI)
and a focal surface that matches the instrument's 15-cm diameter
Rowland-circle. In what follows, we describe the instrument in greater detail,
including descriptions of its ground calibration and initial in flight
performance.


title: A converse to Moore's theorem on cellular automata

abstract:
  We prove a converse to Moore's ``Garden-of-Eden'' theorem: a group G is
amenable if and only if all cellular automata living on G that admit mutually
erasable patterns also admit gardens of Eden.
  It had already been conjectured in that amenability could be characterized by
cellular automata. We prove the first part of that conjecture.


title:
Ralph: A Visible/Infrared Imager for the New Horizons Pluto/Kuiper Belt
  Mission

abstract:
  The New Horizons instrument named Ralph is a visible/near infrared
multi-spectral imager and a short wavelength infrared spectral imager. It is
one of the core instruments on New Horizons, NASA's first mission to the
Pluto/Charon system and the Kuiper Belt. Ralph combines panchromatic and color
imaging capabilities with IR imaging spectroscopy. Its primary purpose is to
map the surface geology and composition of these objects, but it will also be
used for atmospheric studies and to map the surface temperature. It is a
compact, low-mass (10.5 kg), power efficient (7.1 W peak), and robust
instrument with good sensitivity and excellent imaging characteristics. Other
than a door opened once in flight, it has no moving parts. These
characteristics and its high degree of redundancy make Ralph ideally suited to
this long-duration flyby reconnaissance mission.


title:
Glassy protein dynamics and gigantic solvent reorganization energy of
  plastocyanin

abstract:
  We report the results of Molecular Dynamics simulations of electron transfer
activation parameters of plastocyanin metalloprotein involved as electron
carrier in natural photosynthesis. We have discovered that slow, non-ergodic
conformational fluctuations of the protein, coupled to hydrating water, result
in a very broad distribution of donor-acceptor energy gaps far exceeding that
observed for commonly studied inorganic and organic donor-acceptor complexes.
The Stokes shift is not affected by these fluctuations and can be calculated
from solvation models in terms of the response of the solvent dipolar
polarization. The non-ergodic character of large-amplitude protein/water
mobility breaks the strong link between the Stokes shift and reorganization
energy characteristic of equilibrium (ergodic) theories of electron transfer.
This mechanism might be responsible for low activation barriers in natural
electron transfer proteins characterized by low reaction free energy.


title:
Production and detection of atomic hexadecapole at Earth's magnetic
  field

abstract:
  Anisotropy of atomic states is characterized by population differences and
coherences between Zeeman sublevels. It can be efficiently created and probed
via resonant interactions with light, the technique which is at the heart of
modern atomic clocks and magnetometers. Recently, nonlinear magneto-optical
techniques have been developed for selective production and detection of higher
polarization moments, hexadecapole and hexacontatetrapole, in the ground states
of the alkali atoms. Extension of these techniques into the range of
geomagnetic fields is important for practical applications. This is because
hexadecapole polarization corresponding to the $\Delta M=4$ Zeeman coherence,
with maximum possible $\Delta M$ for electronic angular momentum $J=1/2$ and
nuclear spin $I=3/2$, is insensitive to the nonlinear Zeeman effect (NLZ). This
is of particular interest because NLZ normally leads to resonance splitting and
systematic errors in atomic magnetometers. However, optical signals due to the
hexadecapole moment decline sharply as a function of magnetic field. We report
a novel method that allows selective creation of a macroscopic long-lived
ground-state hexadecapole polarization. The immunity of the hexadecapole signal
to NLZ is demonstrated with F=2 $^{87}$Rb atoms at Earth's field.


title: A squeezing formalism for finite dimensional quantum systems

abstract:
  This article presents a squeezing transformation for quantum systems
associated to finite vector spaces. The physical idea of squeezing here is
taken from the action of the usual squeezing operator over wave functions
defined on a real line, that is, a transformation capable to diminish (or
enhance) the mean square deviation of a centered distribution. As it is
discussed, the definition of such an operator on finite dimensional vector
spaces is not a trivial matter, but, on the other hand, has obvious connections
with problems such as spin squeezing and (finite) quantum state reproduction.


title:
Weak convergence of Vervaat and Vervaat Error processes of long-range
  dependent sequences

abstract:
  Following Cs\"{o}rg\H{o}, Szyszkowicz and Wang (Ann. Statist. {\bf 34},
(2006), 1013--1044) we consider a long range dependent linear sequence. We
prove weak convergence of the uniform Vervaat and the uniform Vervaat error
processes, extending their results to distributions with unbounded support and
removing normality assumption.


title:
On the Radial Distribution of White Dwarfs in the Globular Cluster NGC
  6397

abstract:
  We have examined the radial distribution of white dwarfs over a single
HST/ACS field in the nearby globular cluster NGC 6397. In relaxed populations,
such as in a globular cluster, stellar velocity dispersion, and hence radial
distribution, is directly dependent on stellar masses. The progenitors of very
young cluster white dwarfs had a mass of ~0.8 solar masses, while the white
dwarfs themselves have a mass of ~0.5 solar masses. We thus expect young white
dwarfs to have a concentrated radial distribution (like that of their
progenitors) that becomes more extended over several relaxation times to mimic
that of ~0.5 solar mass main-sequence stars. However, we observe young white
dwarfs to have a significantly extended radial distribution compared to both
the most massive main sequence stars in the cluster and also to old white
dwarfs.


title: Magnetic Field Upper Limits for Jet Formation

abstract:
  Context: Very high magnetic fields at the surface of neutron stars or in the
accretion disk of black holes inhibit the production of jets. Aims: We quantify
here the magnetic field strength for jet formation. Methods: By using the
Alfven Radius, R_A, we study what we call {\it the basic condition}, R_A/R_*=1
or R_A/R_{LSO}=1 (LSO, last stable orbit), in its dependency on the magnetic
field strength and the mass accretion rate, and we analyse these results in 3-D
and 2-D plots in the case of neutron star and black hole accretor systems,
respectively. For this purpose, we did a systematic search of all available
observational data for magnetic field strength and the mass accretion rate.
Results: The association of a classical X-ray pulsar (i.e. B ~10^{12} G) with
jets is excluded even if accreting at the Eddington critical rate. Z-sources
may develop jets for B \simlt 10^{8.2} G, whereas Atoll-sources are potential
sources of jets if B \simlt 10^{7.7} G. It is not ruled out that a millisecond
X-ray pulsar could develop jets, at least for those sources where B \simlt
10^{7.5} G. In this case the millisecond X-ray pulsar could switch to a
microquasar phase during its maximum accretion rate. For stellar-mass black
hole X-ray binaries, the condition is that B \simlt 1.35 x 10^8 G and B \simlt
5 x 10^8 G at the last stable orbit for a Schwarzschild and a Kerr black hole,
respectively. For active galactic nuclei (AGNs), it reaches B \simlt 10^{5.9} G
for each kind of black hole. These theoretical results are in complete
agreement with available observational data.


title: The New Horizons Spacecraft

abstract:
  The New Horizons spacecraft was launched on 19 January 2006. The spacecraft
was designed to provide a platform for seven instruments that will collect and
return data from Pluto in 2015. The design drew on heritage from previous
missions developed at The Johns Hopkins University Applied Physics Laboratory
(APL) and other missions such as Ulysses. The trajectory design imposed
constraints on mass and structural strength to meet the high launch
acceleration needed to reach the Pluto system prior to the year 2020. The
spacecraft subsystems were designed to meet tight mass and power allocations,
yet provide the necessary control and data handling finesse to support data
collection and return when the one-way light time during the Pluto flyby is 4.5
hours. Missions to the outer solar system require a radioisotope thermoelectric
generator (RTG) to supply electrical power, and a single RTG is used by New
Horizons. To accommodate this constraint, the spacecraft electronics were
designed to operate on less than 200 W. The spacecraft system architecture
provides sufficient redundancy to provide a probability of mission success of
greater than 0.85, even with a mission duration of over 10 years. The
spacecraft is now on its way to Pluto, with an arrival date of 14 July 2015.
Initial inflight tests have verified that the spacecraft will meet the design
requirements.


title: Optical limiting using Laguerre-Gaussian beams

abstract:
  We demonstrate optical limiting using the self-lensing effect of a
higher-order Laguerre-Gaussian beam in a thin dye-doped polymer sample, which
we find is consistent with our model using Gaussian decomposition. The peak
phase shift in the sample required for limiting is smaller than for a
fundamental Gaussian beam with the added flexibility that the nonlinear medium
can be placed either in front of or behind the beam focus.


title: HIP 56948: A Solar Twin With a Low Lithium Abundance

abstract:
  For more than a decade, 18 Sco (HD 146233) has been considered the star that
most closely resembles the Sun, even though significant differences such as its
Li content, which is about three times solar, exist. Using high resolution,
high S/N spectra obtained at McDonald Observatory, we show that the stars HIP
56948 and HIP 73815 are very similar to the Sun in both stellar parameters and
chemical composition, including a low Li abundance, which was previously
thought to be peculiar in the Sun. HIP 56948, in particular, has stellar
parameters identical to solar within the observational uncertainties, being
thus the best solar twin known to date. HIP 56948 is also similar to the Sun in
its lack of hot Jupiters. Considering the age of this star (1+/-1 Gyr older
than the Sun) and its location and orbit around the Galaxy, if terrestrial
planets exist around it, they may have had enough time to develop complex life,
making it a prime target for SETI.


title: Affine descents and the Steinberg torus

abstract:
  Let $W\ltimes L$ be an irreducible affine Weyl group with Coxeter complex
$\Sigma$, where $W$ denotes the associated finite Weyl group and $L$ the
translation subgroup. The Steinberg torus is the Boolean cell complex obtained
by taking the quotient of $\Sigma$ by the lattice $L$. We show that the
ordinary and flag $h$-polynomials of the Steinberg torus (with the empty face
deleted) are generating functions over $W$ for a descent-like statistic first
studied by Cellini. We also show that the ordinary $h$-polynomial has a
nonnegative $\gamma$-vector, and hence, symmetric and unimodal coefficients. In
the classical cases, we also provide expansions, identities, and generating
functions for the $h$-polynomials of Steinberg tori.


title: Reduced State Uniquely Defines Groverian Measure of Original Pure State

abstract:
  Groverian and Geometric entanglement measures of the n-party pure state are
expressed by the (n-1)-party reduced state density operator directly. This main
theorem derives several important consequences. First, if two pure n-qudit
states have reduced states of (n-1)-qudits, which are equivalent under local
unitary(LU) transformations, then they have equal Groverian and Geometric
entanglement measures. Second, both measures have an upper bound for pure
states. However, this upper bound is reached only for two qubit systems. Third,
it converts effectively the nonlinear eigenvalue problem for three qubit
Groverian measure into linear eigenvalue equations. Some typical solutions of
these linear equations are written explicitly and the features of the general
solution are discussed in detail.


title: Quark helicity flip and the transverse spin dependence of inclusive DIS

abstract:
  Inclusive DIS with unpolarized beam exhibits a subtle dependence on the
transverse target spin, arising from the interference of one-photon and
two-photon exchange amplitudes in the cross section. We argue that this
observable probes mainly the quark helicity-flip amplitudes induced by the
non-perturbative vacuum structure of QCD (spontaneous chiral symmetry
breaking). This conjecture is based on (a) the absence of significant Sudakov
suppression of the helicity-flip process if soft gluon emission in the quark
subprocess is limited by the chiral symmetry-breaking scale mu_chiral^2 >>
Lambda_QCD^2; (b) the expectation that the quark helicity-conserving twist-3
contribution is small. The normal target spin asymmetry is estimated to be of
the order 10^{-4} in the kinematics of the planned Jefferson Lab Hall A
experiment.


title:
New constraints on dark energy from the observed growth of the most
  X-ray luminous galaxy clusters

abstract:
  We present constraints on the mean matter density, Omega_m, the normalization
of the density fluctuation power spectrum, sigma_8, and the dark-energy
equation-of-state parameter, w, obtained from measurements of the X-ray
luminosity function of the largest known galaxy clusters at redshifts z<0.7, as
compiled in the Massive Cluster Survey (MACS) and the local BCS and REFLEX
galaxy cluster samples. Our analysis employs an observed mass-luminosity
relation, calibrated by hydrodynamical simulations, including corrections for
non-thermal pressure support and accounting for the presence of intrinsic
scatter. Conservative allowances for all known systematic uncertainties are
included, as are standard priors on the Hubble constant and mean baryon
density. We find Omega_m=0.28 +0.11 -0.07 and sigma_8=0.78 +0.11 -0.13 for a
spatially flat, cosmological-constant model, and Omega_m=0.24 +0.15 -0.07,
sigma_8=0.85 +0.13 -0.20 and w=-1.4 +0.4 -0.7 for a flat, constant-w model.
Future work improving our understanding of redshift evolution and observational
biases affecting the mass--X-ray luminosity relation have the potential to
significantly tighten these constraints. Our results are consistent with those
from recent analyses of type Ia supernovae, cosmic microwave background
anisotropies, the X-ray gas mass fraction of relaxed galaxy clusters, baryon
acoustic oscillations and cosmic shear. Combining the new X-ray luminosity
function data with current supernova, cosmic microwave background and cluster
gas fraction data yields the improved constraints Omega_m=0.269 +- 0.016,
sigma_8=0.82 +- 0.03 and w=-1.02 +- 0.06. (Abridged)


title:
NeIII/OII as an oxygen abundance indicator in the HII regions and HII
  galaxies

abstract:
  To calibrate the relationship between Ne3O2 (Ne3O2 =
log(\neiii$\lambda3869$/\oii$\lambda3727$)) and oxygen abundances, we present a
sample of $\sim$3000 $\hii$ galaxies from the Sloan Digital Sky Survey (SDSS)
data release four. They are associated with a sample from the literature
intended to enlarge the oxygen abundance region. We calculated the electron
temperatures ($T_e$) of 210 galaxies in the SDSS sample with the direct method,
and $T_e$ of the other 2960 galaxies in SDSS sample calculated with an
empirical method. Then, we use a linear least-square fitting to calibrate the
Ne3O2 oxygen abundance indicator. It is found that the Ne3O2 estimator follows
a linear relation with \zoh\ that holds for the whole abundance range covered
by the sample, from approximately 7.0 to 9.0. The best linear relationship
between the Ne3O2 and the oxygen abundance is calibrated. The dispersion
between oxygen abundance and Ne3O2 index in the metal rich galaxies may come
partly from the moderate depletion of oxygen onto grains. The $Ne3O2$ method
has the virtue of being single-valued and not affected by internal reddening.
As a result, the $Ne3O2$ method can be a good metallicity indicator in the \hii
regions and \hii galaxies, especially in high-redshift galaxies.


title: Chemical System Complexity and Bifurcation Point: a New Relationship

abstract:
  The article introduces a new relationship between the chemical system
complexity and deviation of its bifurcation point from thermodynamic
equilibrium. In the formalism of discrete thermodynamics of chemical
equilibria, simulation of numerous equilibrium cases with regards to complexity
of the reaction hosting systems has lead to a conclusion that the system
deviation from thermodynamic equilibrium at the bifurcation point is directly
proportional to logarithm of the system complexity parameter. With this
relationship one can predict the efforts that are sufficient to destabilize the
system thermodynamic branch and achieve the bifurcations area.


title:
Modulated Branching Processes, Origins of Power Laws and Queueing
  Duality

abstract:
  Power law distributions have been repeatedly observed in a wide variety of
socioeconomic, biological and technological areas. In many of the observations,
e.g., city populations and sizes of living organisms, the objects of interest
evolve due to the replication of their many independent components, e.g.,
births-deaths of individuals and replications of cells. Furthermore, the rates
of the replication are often controlled by exogenous parameters causing periods
of expansion and contraction, e.g., baby booms and busts, economic booms and
recessions, etc. In addition, the sizes of these objects often have reflective
lower boundaries, e.g., cities do not fall bellow a certain size, low income
individuals are subsidized by the government, companies are protected by
bankruptcy laws, etc.
  Hence, it is natural to propose reflected modulated branching processes as
generic models for many of the preceding observations. Indeed, our main results
show that the proposed mathematical models result in power law distributions
under quite general polynomial Gartner-Ellis conditions, the generality of
which could explain the ubiquitous nature of power law distributions. In
addition, on a logarithmic scale, we establish an asymptotic equivalence
between the reflected branching processes and the corresponding multiplicative
ones. The latter, as recognized by Goldie (1991), is known to be dual to
queueing/additive processes. We emphasize this duality further in the
generality of stationary and ergodic processes.


title: Observation of the Supernova Remnant IC 443 with VERITAS

abstract:
  Shell-type supernova remnants (SNRs) accelerate particles at the shock front
between the expanding remnant and the swept-up interstellar medium. If these
particles include protons and nuclei, very-high-energy gamma-ray emission may
result from the decay of pions produced in interactions between cosmic rays and
the local insterstellar medium. For SNRs that are interacting with a nearby
molecular cloud, such as IC 443, the enhanced matter density provides a target
medium that can amplify the gamma-ray emission. IC 443 also contains the pulsar
wind nebula (PWN) CXOU J061705.3+222127. PWNe are the most plentiful galactic
sources of very-high-energy gamma rays, which are produced in the shock formed
at the collision of the pulsar wind with the ambient medium.
  VERITAS is an array of four 12-m telescopes dedicated to gamma-ray astronomy
in the energy band above 100 GeV. Located on Mt. Hopkins in southern Arizona,
VERITAS operated during the 2006-2007 season in 2-, 3-, and 4-telescope
observation modes. In this talk, results from three-telescope observations of
the composite supernova remnant IC 443 during the 2006-2007 season are
discussed.


title: TeV and X-ray Monitoring of LS I +61 303 With VERITAS, Swift, and RXTE

abstract:
  Between September 2006 and February 2007, the galactic binary LS I +61 303
was monitored in the TeV band with the VERITAS array of imaging Cherenkov
telescopes. These observations confirm LS I +61 303 as a variable TeV gamma-ray
source, with emission peaking between orbital phase 0.6 and 0.7. During this
observational period, monitoring in the X-ray regime was also carried out using
both the RXTE and Swift detectors, which offered complementary coverage of the
source. Outbursts in the 0.2-10 keV band were observed by both satellites at
close to the same orbital phase as the TeV peak during the 2 orbital cycles
covered simultaneously in both bands. While this source has been extensively
studied in the X-ray band in the past, this is the first observational campaign
to utilize contemporaneous X-ray and TeV data on LS I +61 303.


title: Observations of the Crab Nebula with the Whipple 10 m Telescope

abstract:
  Due to the strong and steady TeV gamma-ray emission from the Crab Nebula
supernova remnant, its measured flux and energy spectrum can be used to verify
the calibration and data reduction methods applied to IACT data acquired over
many observing seasons. This gives us confidence in the results obtained on
variable TeV sources observed over the same period and in relating the
sensitivity of new instruments to historical datasets. Here we present the
results of an analysis of 65.3 hours of good quality data taken on the Crab
Nebula between October 2000 and March 2006 with the Whipple 10m telescope. The
total exposure resulted in a 46 sigma signal with 11886 selected excess events.
The energy spectrum was best fit by a power law of the form dN/dE = (3.19 +/-
0.07_stat) x 10^-11 (E/TeV)^(-2.64 +/- 0.03_stat) cm^-2/s/TeV in the energy
range 0.49--8 TeV. The systematic uncertainty in the flux was estimated to be
30%, with a systematic error of 0.2 in the photon index. A reasonable agreement
is shown for a fit to a constant flux over the 6 years.


title: A bright millisecond radio burst of extragalactic origin

abstract:
  Pulsar surveys offer one of the few opportunities to monitor even a small
fraction (~0.00001) of the radio sky for impulsive burst-like events with
millisecond durations. In analysis of archival survey data, we have discovered
a 30-Jy dispersed burst of duration <5 ms located three degrees from the Small
Magellanic Cloud. The burst properties argue against a physical association
with our Galaxy or the Small Magellanic Cloud. Current models for the free
electron content in the Universe imply a distance to the burst of <1 Gpc No
further bursts are seen in 90-hr of additional observations, implying that it
was a singular event such as a supernova or coalescence of relativistic
objects. Hundreds of similar events could occur every day and act as insightful
cosmological probes.


title:
Possibilities to verify the level density and radiative strength
  functions, extracted from the two-step gamma-cascade intensities

abstract:
  The direct determination of the excitation level density and radiative
strength functions of their exciting gamma-transitions is impossible for the
larger part of the stable and long-life radioactive target nuclei. This
circumstance is uniquely determined by the fact, that the level spacing much
less than the resolution of the existing spectrometers of gamma-rays and
charged particles. The extraction of these parameters of nucleus in this
situation can be executed by their only fitting to the most probable values,
reproducing the measured in the nuclear reactions spectra and sections. This
inverse problem of mathematical analysis of its nature is principally
ambiguous. Moreover, system of equations, those connecting the number of
excitable levels and probability of the emission of charge particles are
assigned usually within the framework of some assumptions about the mechanism
of nuclear reaction and factors, determining the dynamics of the studied
process. The verification of these parameters can be partially executed by the
calculation of total gamma-spectra for their different sets. As, in particular,
the results of this analysis show, the calculation of the structure of the
excited levels to a change in the form of the energy dependence of radiative
strength functions most likely must be considered to the neutron-binding
energy. It is not possible to exclude the possibility of that, that also
radiative, and neutron strength functions depend on the structure of neutron
resonance and for the higher excitation energies.


title: Security Analyses of One-time System

abstract: This paper has been withdrawn


title:
On the correctness of various approaches in the extraction of the
  nucleus parameters on example of analysis of the two-step gamma-cascades in
  163Dy compound nucleus

abstract:
  The model-free analysis of experimental data in the intensities of two-step
cascades into 163Dy shows, that the basically special features of the cascade
gamma-decay of its compound-state completely correspond to those observed in
other nuclei. Thus, the density of the levels in this nucleus with good
precision it is reproduced as sum of three, five, seven-quasiparticle
excitations with the tenfold, as the minimum, by an increase due to vibration
type excitations. The greatest changes in the sum of the radiation strength
functions of dipole primary gamma-transitions correlate with a change in the
number of excitable quasi-particles. Accordingly, model presentations about the
radiation strength functions of larger, than for those existing, accuracy must
consider as a quantity of excited quasi-particles, so the presence of the
vibration type excitations of all possible types. Moreover, the reliable
picture of the studied process can be obtained only from the approximation of
the distributions of the intensities of cascades in the function of energies of
their primary gamma-transitions.


title:
Measurements of the steady streaming flow around oscillating spheres
  using 3D particle tracking velocimetry

abstract:
  Granular particles vibrated in a fluid have been found to exhibit
self-organization with attractive and repulsive interactions between the
particles. These interactions have been attributed to the steady streaming flow
around oscillating particles. Here we examine the steady streaming flow
surrounding a vertically oscillating sphere using three dimensional particle
tracking velocimetry. We present measurements of the flow with the sphere far
from boundaries, close to the bottom wall of the tank, and near another
oscillating sphere. The steady velocity field is found to disagree with
available analytic calculations. When the sphere is oscillated near the bottom
wall the entire topology of the flow changes, resulting in a larger repulsive
region than expected. Previous experiments saw attraction between particles in
the region where the flow around a single particle is repulsive. We conclude
that advection in the streaming flow due to a single particle cannot explain
the observed attractive and repulsive interactions, rather non-linear
interactions between the flows around two or more spheres must be responsible.


title:
Modulation of bilayer quantum Hall states by tilted-field-induced
  subband-Landau-level coupling

abstract:
  We study effects of tilted magnetic fields on energy levels in a
double-quantum-well (DQW) system, focusing on the coupling of subbands and
Landau levels (LLs). The subband-LL coupling induces anticrossings between LLs,
manifested directly in the magnetoresistance. The anticrossing gap becomes
larger than the spin splitting at the tilting angle $\theta \sim 20^\circ $ and
larger than the cyclotron energy at $\theta \sim 50^\circ $, demonstrating that
the subband-LL coupling exerts a strong influence on quantum Hall states even
in at a relatively small $\theta $ and plays a dominant role for larger $\theta
$. We also find that when the DQW potential is asymmetric, LL coupling occurs
even within a subband. Calculations including higher-order coupling reproduce
the experimental results quantitatively well.


title: The rapid decline of the prompt emission in Gamma-Ray Bursts

abstract:
  Many gamma ray bursts (GRBs) have been observed with the Burst-Alert and
X-Ray telescopes of the Swift satellite. The successive `pulses' of these GRBs
end with a fast decline and a fast spectral softening, until they are overtaken
by another pulse, or the last pulse's decline is overtaken by a less
rapidly-varying `afterglow'. The fast decline-phase has been attributed, in the
currently-explored standard fireball model of GRBs, to `high-latitude'
synchrotron emission from a collision of two conical shells. This high latitude
emission does not explain the observed spectral softening. In contrast, the
temporal behaviour and the spectral evolution during the fast-decline phase
agree with the predictions of the cannonball model of GRBs.


title:
The Globular Cluster System of M60 (NGC 4649). I. CFHT MOS Spectroscopy
  and Database

abstract:
  We present the measurement of radial velocities for globular clusters in M60,
giant elliptical galaxy in the Virgo cluster. Target globular cluster
candidates were selected using the Washington photometry based on the deep
$16\arcmin \times 16\arcmin$ images taken at the KPNO 4m and using the $VI$
photometry derived from the HST/WFPC2 archive images. The spectra of the target
objects were obtained using the Multi-Object Spectrograph (MOS) at the
Canada-France-Hawaii Telescope (CFHT). We have measured the radial velocity for
111 objects in the field of M60: 93 globular clusters (72 blue globular
clusters with $1.0\le(C-T_1)<1.7$ and 21 red globular clusters with
$1.7\le(C-T_1)<2.4$), 11 foreground stars, 6 small galaxies, and the nucleus of
M60. The measured velocities of the 93 globular clusters range from $\sim 500$
km s$^{-1}$ to $\sim 1600$ km s$^{-1}$, with a mean value of $1070_{-25}^{+27}$
km s$^{-1}$, which is in good agreement with the velocity of the nucleus of M60
($v_{\rm gal}=1056$ km s$^{-1}$). Combining our results with data in the
literature, we present a master catalog of radial velocities for 121 globular
clusters in M60. The velocity dispersion of the globular clusters in the master
catalog is found to be $234_{-14}^{+13}$ km s$^{-1}$ for the entire sample,
$223_{-16}^{+13}$ km s$^{-1}$ for 83 blue globular clusters, and
$258_{-31}^{+21}$ km s$^{-1}$ for 38 red globular clusters.


title:
The Globular Cluster System of M60 (NGC 4649). II. Kinematics of the
  Globular Cluster System

abstract:
  We present a kinematic analysis of the globular cluster (GC) system in the
giant elliptical galaxy (gE) M60 in the Virgo cluster. Using the photometric
and spectroscopic database of 121 GCs (83 blue GCs and 38 red GCs), we have
investigated the kinematics of the GC system. We have found that the M60 GC
system shows a significant overall rotation. The rotation amplitude of the blue
GCs is slightly smaller than or similar to that of the red GCs, and their
angles of rotation axes are similar. The velocity dispersions about the mean
velocity and about the best fit rotation curve for the red GCs are marginally
larger than those for the blue GCs. Comparison of observed stellar and GC
velocity dispersion profiles with those calculated from the stellar mass
profile shows that the mass-to-light ratio should be increased as the
galactocentric distance increases, indicating the existence of an extended dark
matter halo. The entire sample of GCs in M60 is found to have a tangentially
biased velocity ellipsoid unlike the GC systems in other gEs. Two subsamples
appear to have different velocity ellipsoids. The blue GC system has a modest
tangentially biased velocity ellipsoid, while the red GC system has a modest
radially biased or an isotropic velocity ellipsoid. From the comparison of the
kinematic properties of the M60 GC system to those of other gEs (M87, M49, NGC
1399, NGC 5128, and NGC 4636), it is found that the velocity dispersion of the
blue GC system is similar to or larger than that of the red GC system except
for M60, and the rotation of the GC system is not negligible. The entire sample
of each GC system shows an isotropic velocity ellipsoid except for M60, while
the subsamples show diverse velocity ellipsoids. We discuss the implication of
these results for the formation models of the GC system in gEs.


title: Extensions and degenerations of spectral triples

abstract:
  For a unital C*-algebra A, which is equipped with a spectral triple and an
extension T of A by the compacts, we construct a family of spectral triples
associated to T and depending on the two positive parameters (s,t).
  Using Rieffel's notation of quantum Gromov-Hausdorff distance between compact
quantum metric spaces it is possible to define a metric on this family of
spectral triples, and we show that the distance between a pair of spectral
triples varies continuously with respect to the parameters. It turns out that a
spectral triple associated to the unitarization of the algebra of compact
operators is obtained under the limit - in this metric - for (s,1) -> (0, 1),
while the basic spectral triple, associated to A, is obtained from this family
under a sort of a dual limiting process for (1, t) -> (1, 0).
  We show that our constructions will provide families of spectral triples for
the unitarized compacts and for the Podles sphere. In the case of the compacts
we investigate to which extent our proposed spectral triple satisfies Connes' 7
axioms for noncommutative geometry.


title:
Bounds for the second and the third derivatives of the electron density
  at the nucleus

abstract:
  Lower bound for ${\bar \rho}''(0)$, the second derivative of the spherically
averaged atomic electronic density at the nucleus, and upper bound for ${\bar
\rho}'''(0)$, the third derivative, are obtained respectively. It is shown
that, for the ground state, ${\bar \rho}''(0) \ge {10/3} Z^2 \rho(0)$ and
${\bar \rho}'''(0) \le -{14/3}Z^3 \rho(0)$ where $Z$ is the charge of the
nucleus, and $\rho(0)$ is the electron density at the nucleus. Tighter bounds
for ${\bar \rho}''(0)$ and ${\bar \rho}'''(0)$ are also reported which are
valid for both the ground state and excited states. Explicit illustration with
the example of one-electron atomic ions is given.


title: Universality of quantum symplectic structure

abstract:
  Operating in the framework of `supmech' (a scheme of mechanics which aims at
providing a concrete setting for the axiomatization of physics and probability
theory as required in Hilbert's sixth problem; integrating noncommutative
symplectic geometry and noncommutative probability in an algebraic setting, it
associates, with every `experimentally accessible' system, a symplectic algebra
and operates essentially as noncommutative Hamiltonian mechanics with some
extra sophistication in the treatment of states) it is shown that interaction
between systems can be consistently described only if either (i) all system
algebras are commutative or (ii) all system algebras are noncommutative and
have a quantum symplectic structure characterized by a UNIVERSAL Planck type
real-valued constant of the dimension of action.

categories: math.SG math-ph math.MP math.QA quant-ph


title: Schwinger Mechanism and Hawking Radiation as Quantum Tunneling

abstract:
  The common interpretation of the Hawking radiation as quantum tunneling has
some ambiguity such as coordinate-dependence of tunneling rate and
non-invariance of the action under canonical transformations. It is shown that
the tunneling process of black holes can be successfully described by Rindler
coordinates in analogy with the Schwinger mechanism for pair production. We
study the tunneling process of a charged black hole and a BTZ black hole.


title: Experimental demonstration of quantum leader election in linear optics

abstract:
  Linear optics is a promising candidate to enable the construction of quantum
computers. A number of quantum protocols gates based on linear optics have been
demonstrated. However, it is well-known that these gates are non-deterministic
and that higher order nonlinearity is necessary for deterministic operations.
We found the quantum leader election protocol (QLE) can be operated
deterministically only with linear optics, and we have demonstrated the nearly
deterministic operation which overcomes classical limit.


title: Pulsar Magnetic Field Oscillation Model and Verification Methods

abstract:
  We constructed the magnetic field oscillation model (hereafter the MO model)
by analogizing the periodically reversing phenomenon of the solar magnetic
field to pulsars. Almost all kinds of pulsar radiation phenomena are best
explained using the MO model, especially polarization characteristics, glitch,
generation rate, the geodetic precession of pulsars and the configuration of
pulsar-wind nebula of the Crab. The MO model also provides satisfactory
explanation for other characteristics of pulsars, e.g., interpulse, spin-down,
pulse nulling, beat and pulse drift, the loss rate of the rotating energy, and
the accuracy of frequency. We present eight verification methods for the MO
model. In addition to pulsars, our MO model can also be used to explain the
pulse emission from non-compact stars such as the ultracool dwarf TVLM
513-46546 and the magnetic chemically peculiar star CU Virginis.


title: Confidence intervals for the normal mean utilizing prior information

abstract:
  Consider X_1,X_2,...,X_n that are independent and identically N(mu,sigma^2)
distributed. Suppose that we have uncertain prior information that mu = 0. We
answer the question: to what extent can a frequentist 1-alpha confidence
interval for mu utilize this prior information?


title:
The connection between noise and quantum correlations in a double
  quantum dot

abstract:
  We investigate the current and noise characteristics of a double quantum dot
system. The strong correlations induced by the Coulomb interaction create
entangled two-electron states and lead to signatures in the transport
properties. We show that the interaction parameter phi, which measures the
admixture of the double-occupancy contribution to the singlet state and thus
the degree of entanglement, can be directly accessed through the Fano factor of
super-Poissonian shot noise.


title:
Comparative study between N-body and Fokker-Planck simulations for
  rotating star clusters: I. Equal-mass system

abstract:
  We have carried out N-body simulations for rotating star clusters with equal
mass and compared the results with Fokker-Planck models. These two different
approaches are found to produce fairly similar results, although there are some
differences with regard to the detailed aspects. We confirmed the acceleration
of the core collapse of a cluster due to an initial non-zero angular momentum
and found a similar evolutionary trend in the central density and velocity
dispersion in both simulations. The degree of acceleration depends on the
initial angular momentum. Angular momentum is being lost from the cluster due
to the evaporation of stars with a large angular momentum on a relaxation time
scale.


title: Local density of diffeomorphisms with large centralizers

abstract:
  Given any compact manifold M, we construct a non-empty open subset O of the
space of C^1-diffeomorphisms of M and a dense subset D of O such that the
centralizer of every diffeomorphism in D is uncountable, hence non-trivial.


title:
Experimental observation of the Anderson transition with atomic matter
  waves

abstract:
  We realize experimentally an atom-optics quantum chaotic system, the
quasiperiodic kicked rotor, which is equivalent to a 3D disordered system, that
allow us to demonstrate the Anderson metal-insulator transition. Sensitive
measurements of the atomic wavefunction dynamics and the use of finite-size
scaling techniques make it possible to extract both the critical parameters and
the critical exponent of the transition, which is in good agreement with the
value obtained in numerical simulations of the 3D Anderson model.

categories: quant-ph cond-mat.mes-hall cond-mat.other cond-mat.stat-mech nlin.CD physics.optics


title:
Chaotic scattering with direct processes: A generalization of Poisson's
  kernel for non-unitary scattering matrices

abstract:
  The problem of chaotic scattering in presence of direct processes or prompt
responses is mapped via a transformation to the case of scattering in absence
of such processes for non-unitary scattering matrices, \tilde S. In the absence
of prompt responses, \tilde S is uniformly distributed according to its
invariant measure in the space of \tilde S matrices with zero average, < \tilde
S > =0. In the presence of direct processes, the distribution of \tilde S is
non-uniform and it is characterized by the average < \tilde S > (\neq 0). In
contrast to the case of unitary matrices S, where the invariant measures of S
for chaotic scattering with and without direct processes are related through
the well known Poisson kernel, here we show that for non-unitary scattering
matrices the invariant measures are related by the Poisson kernel squared. Our
results are relevant to situations where flux conservation is not satisfied.
For example, transport experiments in chaotic systems, where gains or losses
are present, like microwave chaotic cavities or graphs, and acoustic or elastic
resonators.


title:
Rich methane laminar flames doped with light unsaturated hydrocarbons.
  Part II: 1,3butadiene

abstract:
  In line with the study presented in the part I of this paper, the structure
of a laminar rich premixed methane flame doped with 1,3-butadiene has been
investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and
3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a
ratio C4H6 / CH4 of 16 %. The flame has been stabilized on a burner at a
pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner
of 36 cm/s at 333 K. The temperature ranged from 600 K close to the burner up
to 2150 K. Quantified species included usual methane C0-C2 combustion products
and 1,3-butadiene, but also propyne, allene, propene, propane, 1,2-butadiene,
butynes, vinylacetylene, diacetylene, 1,3-pentadiene, 2-methyl-1,3-butadiene
(isoprene), 1-pentene, 3-methyl-1-butene, benzene and toluene. In order to
model these new results, some improvements have been made to a mechanism
previously developed in our laboratory for the reactions of C3-C4 unsaturated
hydrocarbons. The main reaction pathways of consumption of 1,3-butadiene and of
formation of C6 aromatic species have been derived from flow rate analyses. In
this case, the C4 route to benzene formation plays an important role in
comparison to the C3 pathway.


title: Markov basis for design of experiments with three-level factors

abstract:
  We consider Markov basis arising from fractional factorial designs with
three-level factors. Once we have a Markov basis, $p$ values for various
conditional tests are estimated by the Markov chain Monte Carlo procedure. For
designed experiments with a single count observation for each run, we formulate
a generalized linear model and consider a sample space with the same sufficient
statistics to the observed data. Each model is characterized by a covariate
matrix, which is constructed from the main and the interaction effects we
intend to measure. We investigate fractional factorial designs with $3^{p-q}$
runs noting correspondences to the models for $3^{p-q}$ contingency tables.


title: Hard Squares for z = -1

abstract:
  The hard square model in statistical mechanics has been investigated for the
case when the activity z is -1. For cyclic boundary conditions, the
characteristic polynomial of the transfer matrix has an intriguingly simple
structure, all the eigenvalues $x$ being zero, roots of unity, or solutions of
x^3 = 4 cos^2 (pi*m/N). Here we tabulate the results for lattices of up to 12
columns with cyclic or free boundary conditions and the two obvious
orientations. We remark that they are all unexpectedly simple and that for the
rotated lattice with free or fixed boundary conditions there are obvious likely
generalizations to any lattice size.


title:
Crypto-Harmonic Oscillator in Higher Dimensions: Classical and Quantum
  Aspects

abstract:
  We study complexified Harmonic Oscillator models in two and three dimensions.
Our work is a generalization of the work of Smilga \cite{sm} who initiated the
study of these Crypto-gauge invariant models that can be related to
$PT$-symmetric models. We show that rotational symmetry in higher spatial
dimensions naturally introduces more constraints, (in contrast to \cite{sm}
where one deals with a single constraint), with a much richer constraint
structure. Some common as well as distinct features in the study of the same
Crypto-oscillator in different dimensions are revealed. We also quantize the
two dimensional Crypto-oscillator.


title: Some properties of group-theoretical categories

abstract:
  We first show that every group-theoretical category is graded by a certain
double coset ring. As a consequence, we obtain a necessary and sufficient
condition for a group-theoretical category to be nilpotent. We then give an
explicit description of the simple objects in a group-theoretical category
(following Ostrik, arXiv:math/0202130) and of the group of invertible objects
of a group-theoretical category, in group-theoretical terms. Finally, under
certain restrictive conditions, we describe the universal grading group of a
group-theoretical category.


title: On and beyond entropy production: the case of Markov jump processes

abstract:
  How is it that entropy derivatives almost in their own are characterizing the
state of a system close to equilibrium, and what happens further away from it?
We explain within the framework of Markov jump processes why fluctuation theory
can be based on considerations involving entropy production alone when
perturbing around the detailed balance condition. Variational principles such
as that of minimum entropy production are understood in that way. Yet, further
away from equilibrium, dynamical fluctuations reveal a structure where the
time-symmetric sector crucially enters. The fluctuations of densities and
currents get coupled and a time-symmetric notion of dynamical activity becomes
the counterpart and equal player to the entropy production. The results are
summarized in an extended Onsager-Machlup Lagrangian, which in its quadratic
approximation is expected to be quite general in governing the small
fluctuations of nonequilibrium systems whose macroscopic behavior can be
written in terms of a Master equation autonomously describing the
time-dependence of densities and currents.


title: Deeply Virtual Compton Scattering at JLab Hall A

abstract:
  The deeply virtual Compton scattering reaction has been investigated in the
Hall A of the Jefferson Laboratory by measuring longitudinally polarized
(e,e'gamma) cross sections, in the valence quark region, for protons and
neutrons. In the proton channel, experimental results strongly support the
factorization of the cross section at Q2 as low as 2 GeV2, opening the path to
systematic measurements of generalized parton distributions (GPDs). In the
neutron case, preliminary data show sensitivity to the angular momentum of
quarks.
http://indico.cern.ch/contributionDisplay.py?contribId=89&sessionId=12&confId=9499


title: Detecting unambiguously non-Abelian geometric phases with trapped ions

abstract:
  We propose for the first time an experimentally feasible scheme to disclose
the noncommutative effects induced by a light-induced non-Abelian gauge
structure with trapped ions. Under an appropriate configuration, a true
non-Abelian gauge potential naturally arises in connection with the geometric
phase associated with two degenerated dark states in a four-state atomic system
interacting with three pulsed laser fields. We show that the population in
atomic state at the end of a composed path formed by two closed loops $C_1$ and
$C_2$ in the parameter space can be significantly different from the composed
counter-ordered path. This population difference is directly induced by the
noncommutative feature of non-Abelian geometric phases and can be detected
unambiguously with current technology.


title:
Magneto-gyrotropic photogalvanic effects in GaN/AlGaN two-dimensional
  systems

abstract:
  The magneto-gyrotropic photogalvanic and spin-galvanic effects are observed
in (0001)-oriented GaN/AlGaN heterojunctions excited by terahertz radiation. We
show that free-carrier absorption of linearly or circularly polarized terahertz
radiation in low-dimensional structures causes an electric photocurrent in the
presence of an in-plane magnetic field. Microscopic mechanisms of these
photocurrents based on spin-related phenomena are discussed. Properties of the
magneto-gyrotropic and spin-galvanic effects specific for hexagonal
heterostructures are analyzed.


title: Spiral Galaxies in the SAURON Survey

abstract:
  We discuss some recent integral field spectroscopy using the SAURON
instrument of a sample consisting of 24 early-type spirals, part of the SAURON
Survey, and 18 late-type spirals. Using 2-dimensional maps of their stellar
radial velocity, velocity dispersion, and absorption line strength, it is now
much easier to understand the nature of nearby galactic bulges. We discuss a
few highlights of this work, and point out some new ideas about the formation
of galactic bulges.


title: Sharp results in the integral-form John--Nirenberg inequality

abstract:
  We consider the strong form of the John-Nirenberg inequality for the
$L^2$-based BMO. We construct explicit Bellman functions for the inequality in
the continuous and dyadic settings and obtain the sharp constant as well as the
precise bound on the inequality's range of validity, both previously unknown.
The results for the two cases are substantially different. The paper not only
gives another instance in the short list of such explicit calculations, but
also presents the Bellman function method as a sequence of clear steps,
adaptable to a wide variety of applications.


title: BAT X-ray Survey - III: X-ray Spectra and Statistical Properties

abstract:
  In this concluding part of the series of three papers dedicated to the
Swift/BAT hard X-ray survey (BXS), we focus on the X-ray spectral analysis and
statistical properties of the source sample. Using a dedicated method to
extract time-averaged spectra of BAT sources we show that Galactic sources
have, generally, softer spectra than extragalactic objects and that Seyfert 2
galaxies are harder than Seyfert 1s. The averaged spectrum of all Seyfert
galaxies is consistent with a power-law with photon index of 2.00 (+/-0.07).
The cumulative flux-number relation for the extragalactic sources in the 14-170
keV band is best described by a power-law with a slope alpha=1.55 (+/-0.20) and
a normalization of 9.6$\pm1.9 \times 10^{-3}$ AGN deg$^{-2}$ (or 396(+/-80) AGN
all-sky) above a flux level of 2$\times 10^{-11}$erg cm$^{-2}$ s$^{-1}$ (~0.85
mCrab). The integration of the cumulative flux per unit area indicates that BAT
resolves 1-2% of the X-ray background emission in the 14-170 keV band. A
sub-sample of 24 extragalactic sources above the 4.5 sigma detection limit is
used to study the statistical properties of AGN. This sample comprises local
Seyfert galaxies (z=0.026, median value) and ~10% blazars. We find that 55% of
the Seyfert galaxies are absorbed by column densities of Log(N_H)>22, but that
none is a bona fide Compton-thick. This study shows the capabilities of BAT to
probe the hard X-ray sky to the mCrab level.


title:
Noncommutative Brownian motions with Kesten distributions and related
  Poisson processes

abstract:
  We introduce and study a noncommutative two-parameter family of
noncommutative Brownian motions in the free Fock space. They are associated
with Kesten laws and give a continuous interpolation between Brownian motions
in free probability and monotone probability. The combinatorics of our model is
based on ordered non-crossing partitions, in which to each such partition $P$
we assign a weight depending on the numbers of disorders and orders in $P$
related to the natural partial order on the set of blocks of $P$ implemented by
the relation of being inner or outer. In particular, we obtain a simple
relation between Delaney's numbers (related to inner blocks in non-crossing
partitions) and generalized Euler's numbers (related to orders and disorders in
ordered non-crossing partitions). An important feature of our interpolation is
that the mixed moments of the corresponding creation and annihilation processes
also reproduce their monotone and free counterparts, which does not take place
in other interpolations. The same combinatorics is used to construct an
interpolation between free and monotone Poisson processes.