title:
Deep surface photometry of edge-on spirals in Abell galaxy clusters:
  constraining environmental effects

abstract:
  There is a clear scarcity of structural parameters for stellar thick discs,
especially for spiral galaxies located in high-density regions, such as galaxy
clusters and compact groups. We have modelled the thin and thick discs of 4
edge-on spirals located in Abell clusters: NGC 705, ESO243G49, ESO187G19,
LCSBS0496P. Deep I band images of NGC 705 were taken from the HST archive,
whereas the remaining images were obtained with the Southern Telescope for
Astrophysical Research (SOAR) in Gunn r filter. They reached surface brightness
levels of $\mu_I \simeq 26.0$ mag arcsec$^{-2}$ and $\mu_r \simeq 26.5$ mag
arcsec$^{-2}$, respectively. Profiles were extracted from the deep images, in
directions both parallel and perpendicular to the major axis. Profile fits were
carried out at several positions, yielding horizontal and vertical scale
parameters for both thin and thick disc components. The extracted profiles and
fitted disc parameters vary from galaxy to galaxy. Two galaxies have a
horizontal profile with a strong down-turn at outer radii, preventing a simple
exponential from fitting the entire range. For the 2 early-type spirals, the
thick discs have larger scalelengths than the thin discs, whereas no trend is
seen for the later types . Both the thin and thick discs sampled tend to have
similar scalelengths and scaleheights when compared to typical field disc
galaxies. However, the thin disc parameters of the 2 farthest galaxies, both
late-type spirals, may be significantly affected by seeing effects. Taken at
face value, our results suggest that environment plays a minor role in
determining the thin and thick disc sizes.


title: Spin-magnetophonon level splitting in semimagnetic quantum wells

abstract:
  Spin-magnetophonon level splitting in a quantum well made of a semimagnetic
wide gap semiconductor is considered. The semimagnetic semiconductors are
characterized by a large effective $g$ factor. The resonance conditions
$\hbar\omega_{\rm LO}=\mu_BgB$ for the spin flip between two Zeeman levels due
to interaction with longitudinal optical phonons can be achieved sweeping
magnetic field $B$. This condition is studied in quantum wells. It is shown
that it leads to a level splitting that is dependent on the electron-phonon
coupling strength as well as on the spin-orbit interaction in this structure.
  We treat in detail the Rashba model for the spin-orbit interaction assuming
that the quantum well lacks inversion symmetry and briefly discuss other
models. The resonant transmission and reflection of light by the well is
suggested as a suitable experimental probe of the level splitting.


title:
Digraphs with a fixed number of edges and vertices, having a maximal
  number of walks of length 2

abstract:
  Inspired by the work of Backelin on non-commutative correspondences to
Macaulay's theorem of the growth of the Hilbert series of affine algebras, we
study embedding dimension dependant versions of his degree 2 to degree 3
result. In graph-theoretical terms, we study the following question: what is
the maximal number of directed walks of length 2 in a digraph with (k) edges
and (n) vertices? The problem can also be formulated as follows: maximize (<
\lambda, \lambda^T >) when (\lambda) is a partition of (k), contained in an (n
\times n) box. We show that for mild restrictions on (n), optimal digraphs are
the ``stars of saturated stars''.


title:
De Broglie-Bohm Prediction of Quantum Violations for Cosmological
  Super-Hubble Modes

abstract:
  The hypothesis of quantum nonequilibrium at the big bang is shown to have
observable consequences. For a scalar field on expanding space, we show that
relaxation to quantum equilibrium (in de Broglie-Bohm theory) is suppressed for
field modes whose quantum time evolution satisfies a certain inequality,
resulting in a 'freezing' of early quantum nonequilibrium for these particular
modes. For an early radiation-dominated expansion, the inequality implies a
corresponding physical wavelength that is larger than the (instantaneous)
Hubble radius. These results make it possible, for the first time, to make
quantitative predictions for nonequilibrium deviations from quantum theory, in
the context of specific cosmological models. We discuss some possible
consequences: corrections to inflationary predictions for the cosmic microwave
background, non-inflationary super-Hubble field correlations, and relic
nonequilibrium particles.


title: Brill-Noether-type Theorems with a Movable Ramification Point

abstract:
  The classical Brill-Noether theorems count the dimension of the family of
maps from a general curve of genus g to non-degenerate curves of degree d in
r-dimensional projective space. These theorems can be extended to include
ramification conditions at fixed general points. This paper deals with the
problem of imposing a ramification condition at an unspecified point. We solve
the problem completely in dimensions 1 and 2, and provide an existence test and
bound the dimension of the family in the general case.


title: S_3-covers of schemes

abstract:
  We analyze flat S_3-covers, attempting to create structures parallel to those
found in the abelian theory. We use an initial local analysis as a guide in
finding a global description.


title: Rotating soliton solutions in nonlocal nonlinear media

abstract:
  We discuss generic properties of rotating nonlinear wave solutions, the so
called azimuthons, in nonlocal media. Variational methods allow us to derive
approximative values for the rotating frequency, which is shown to depend
crucially on the nonlocal response function. Further on, we link families of
azimuthons to internal modes of classical non-rotating stationary solutions,
namely vortex and multipole solitons. This offers an exhaustive method to
identify azimuthons in a given nonlocal medium.


title:
Measurements of Cold Nuclear Matter Effects on J/psi in the PHENIX
  Experiment via Deuteron-Gold Collisions

abstract:
  A new calculation of R_{dAu} has been performed using the 2003 d+Au data and
the higher-statistics 2005 p+p data. These nuclear modification factors are
compared to calculations using nuclear-modified PDFs and a J/psi breakup cross
section is extracted. These values are then used to project the cold nuclear
matter effects in Au+Au collisions. Additionally, a more data-driven projection
is performed.


title:
STAR's measurement of Long-range forward-backward multiplicity
  correlations as the signature of "dense partonic matter" in the Heavy Ion
  collisions at $\sqrt{s_{NN}}=$200 GeV.}

abstract:
  Forward-backward multiplicity correlations have been measured with the STAR
detector for Au+Au, Cu+Cu and {\it p+p} collisions at $\sqrt{s_{NN}}$ = 200
GeV. A strong, long-range correlation is observed for central heavy ion
collisions that vanishes in semi-peripheral events and {\it pp} collisions.
There is no apparent scaling of correlation strength with the number of
participants involved in the collision. Both the Dual Parton Model and the
Color Glass condensate indicate that the long range correlations are due to
multiple parton interactions. This suggests that the dense partonic matter
might have been created in mid-central and central Au+Au collisions at
$\sqrt{s_{NN}}$ = 200 GeV.


title: Rateless Coding for MIMO Block Fading Channels

abstract:
  In this paper the performance limits and design principles of rateless codes
over fading channels are studied. The diversity-multiplexing tradeoff (DMT) is
used to analyze the system performance for all possible transmission rates. It
is revealed from the analysis that the design of such rateless codes follows
the design principle of approximately universal codes for parallel
multiple-input multiple-output (MIMO) channels, in which each sub-channel is a
MIMO channel. More specifically, it is shown that for a single-input
single-output (SISO) channel, the previously developed permutation codes of
unit length for parallel channels having rate LR can be transformed directly
into rateless codes of length L having multiple rate levels (R, 2R, . . ., LR),
to achieve the DMT performance limit.


title: Transitive latin bitrades

abstract:
  In this note we give two results. First, if a latin bitrade $(T_1, T_2)$ is
primary, thin, separated, and the autotopism group of $T_1$ acts regularly on
$T_1$, then $(T_1, T_2)$ may be derived from a group-based construction.
Second, if a latin bitrade $(T_1, T_2)$ has genus 0 then the disjoint mate
$T_2$ is unique and the autotopism group of $T_1$ is equal to the autotopism
group of $T_2$.


title:
Topological symmetry, spin liquids and CFT duals of Polyakov model with
  massless fermions

abstract:
  We prove the absence of a mass gap and confinement in the Polyakov model with
massless complex fermions in any representation of the gauge group. A
$U(1)_{*}$ topological shift symmetry protects the masslessness of one dual
photon. This symmetry emerges in the IR as a consequence of the Callias index
theorem and abelian duality. For matter in the fundamental representation, the
infrared limits of this class of theories interpolate between weakly and
strongly coupled conformal field theory (CFT) depending on the number of
flavors, and provide an infinite class of CFTs in $d=3$ dimensions. The long
distance physics of the model is same as certain stable spin liquids. Altering
the topology of the adjoint Higgs field by turning it into a compact scalar
does not change the long distance dynamics in perturbation theory, however,
non-perturbative effects lead to a mass gap for the gauge fluctuations. This
provides conceptual clarity to many subtle issues about compact QED$_3$
discussed in the context of quantum magnets, spin liquids and phase fluctuation
models in cuprate superconductors. These constructions also provide new
insights into zero temperature gauge theory dynamics on $\R^{2,1}$ and
$\R^{2,1} \times S^1$. The confined versus deconfined long distance dynamics is
characterized by a discrete versus continuous topological symmetry.


title: Spitzer Observations of Supernova Remnant IC 443

abstract:
  We present Spitzer observations of IC 443 obtained with MIPS and IRS as part
of our GTO program on the astrophysics of ejecta from evolved stars. We find
that the overall morphology at mid/far IR wavelengths resembles even more
closely a loop or a shell than the ground based optical and/or near IR
images.The dust temperature map, based on the 70/160micron ratio, shows a range
from 18 to 30 K degrees. The IRS spectra confirm the findings from previous
near+mid IR spectroscopic observations of a collisionally excited gas, atomic
and molecular, rich in fine structure atomic and pure H2 rotational emission
lines, respectively. The spectroscopic shock indicator, [Ne II] 12.8micron,
suggests shock velocities ranging from 60-90 km/s, consistent with the values
derived from other indicators.


title:
Combining geometry and combinatorics: A unified approach to sparse
  signal recovery

abstract:
  There are two main algorithmic approaches to sparse signal recovery:
geometric and combinatorial. The geometric approach starts with a geometric
constraint on the measurement matrix and then uses linear programming to decode
information about the signal from its measurements. The combinatorial approach
constructs the measurement matrix and a combinatorial decoding algorithm to
match. We present a unified approach to these two classes of sparse signal
recovery algorithms.
  The unifying elements are the adjacency matrices of high-quality unbalanced
expanders. We generalize the notion of Restricted Isometry Property (RIP),
crucial to compressed sensing results for signal recovery, from the Euclidean
norm to the l_p norm for p about 1, and then show that unbalanced expanders are
essentially equivalent to RIP-p matrices.
  From known deterministic constructions for such matrices, we obtain new
deterministic measurement matrix constructions and algorithms for signal
recovery which, compared to previous deterministic algorithms, are superior in
either the number of measurements or in noise tolerance.


title:
Strong frustration due to competing ferromagnetic and antiferromagnetic
  interactions: magnetic properties of M(VO)2(PO4)2 (M = Ca and Sr)

abstract:
  We present a detailed investigation of the magnetic properties of complex
vanadium phosphates M(VO)2(PO4)2 (M = Ca, Sr) by means of magnetization,
specific heat, 31P NMR measurements, and band structure calculations.
Experimental data evidence the presence of ferro- and antiferromagnetic
interactions in M(VO)2(PO4)2 resulting in a nearly vanishing Curie-Weiss
temperature \theta_{CW} < 1 K that contrasts with the maximum of magnetic
susceptibility at 3 K. Specific heat and NMR measurements also reveal weak
exchange couplings with the thermodynamic energy scale J_c = 10-15 K.
Additionally, the reduced maximum of the magnetic specific heat indicates
strong frustration of the spin system. Band structure calculations show that
the spin systems of the M(VO)2(PO4)2 compounds are essentially
three-dimensional with the frustration caused by competing ferro- and
antiferromagnetic interactions. Both calcium and strontium compounds undergo
antiferromagnetic long-range ordering at T_N = 1.5 K and 1.9 K, respectively.
The spin model reveals an unusual example of controllable frustration in
three-dimensional magnetic systems.


title:
Size effects in the nonlinear resistance and flux creep in a virtual
  Berezinskii-Kosterlitz-Thouless state of superconducting films

abstract:
  We show that the size effects radically affect the electric field-current
($E-I$) relation of superconducting films. We calculate $E(J)$ due to
thermally-activated hopping of single vortices driven by current $I$ across the
film in a magnetic field $H$, taking into account interaction of free vortices
with their antivortex images and peaks in the Meissner currents at the film
edges. Unbinding of virtual vortex-antivortex pairs not only mimics the
transport uniform BKT behavior, it can dominate the observed $E(J)$ and result
in the field-dependent ohmic resistance at small $I$. We show that $E(I)$ can
be tuned by changing the film geometry and propose experimental tests of this
theory.


title: Measuring the Complete Transverse Spatial Mode Spectrum of a Wave Field

abstract:
  We put forward a method that allows the experimental determination of the
entire spatial mode spectrum of any arbitrary monochromatic wave field in a
plane normal to its propagation direction. For coherent optical fields, our
spatial spectrum analyzer can be implemented with a small number of benchmark
refractive elements embedded in a single Mach-Zehnder interferometer. We detail
an efficient setup for measuring in the Hermite-Gaussian mode basis. Our scheme
should also be feasible in the context of atom optics for analyzing the spatial
profiles of macroscopic matter waves.


title: The $N^*(1710)$ as a resonance in the $\pi\pi N$ system

abstract:
  We study the $\pi \pi N$ system by solving the Faddeev equations, for which
the input two-body $t$-matrices are obtained by solving the Bethe-Salpeter
equation in the coupled channel formalism. The potentials for the $\pi \pi$,
$\pi N$ sub-systems and their coupled channels are obtained from chiral
Lagrangians, which have been earlier used to study resonances in these systems
successfully. In this work, we find a resonance in the $\pi\pi N$ system with a
mass of $1704 - i 375/2$ MeV and with quantum numbers $I=1/2$, $J^\pi =1/2^+$.
We identify this state with the $N^*(1710)$. This peak is found where the
energies of the $\pi \pi$ sub-system fall in the region of the $\sigma$
resonance. We do not find evidence for the Roper resonance in our study
indicating a more complex structure for this resonance, nor for any state with
total isospin $I=3/2$ or $5/2$.


title: Scalar curvature and holomorphy potentials

abstract:
  A holomorphy potential is a complex valued function whose complex gradient,
with respect to some K\"ahler metric, is a holomorphic vector field. Given $k$
holomorphic vector fields on a compact complex manifold, form, for a given
K\"ahler metric, a product of the following type: a function of the scalar
curvature multiplied by functions of the holomorphy potentials of each of the
vector fields. It is shown that the stipulation that such a product be itself a
holomorphy potential for yet another vector field singles out critical metrics
for a particular functional. This may be regarded as a generalization of the
extremal metric variation of Calabi, where $k=0$ and the functional is the
square of the $L^2$-norm of the scalar curvature. The existence question for
such metrics is examined in a number of special cases. Examples are constructed
in the case of certain multifactored product manifolds. For the \sk metrics
investigated by Derdzinski and Maschler and residing in the complex projective
space, it is shown that only one type of nontrivial criticality holds in
dimension three and above.


title: Universal Limits on Massless High-Spin Particles

abstract:
  We present a model-independent argument showing that massless particles
interacting with gravity in a Minkowski background space can have at most spin
two. This result is proven by extending a famous theorem due to Weinberg and
Witten to theories that do not possess a gauge-invariant stress-energy tensor.


title:
The Peculiar Volatile Composition of Comet 8P/Tuttle: A Contact Binary
  of Chemically Distinct Cometesimals?

abstract:
  We report measurements of eight native (i.e., released directly from the
comet nucleus) volatiles (H2O, HCN, CH4, C2H2, C2H6, CO, H2CO, and CH3OH) in
comet 8P/Tuttle using NIRSPEC at Keck 2. Comet Tuttle reveals a truly unusual
composition, distinct from that of any comet observed to date at infrared
wavelengths. The prominent enrichment of methanol relative to water contrasts
the depletions of other molecules, especially C2H2 and HCN. We suggest that the
nucleus of 8P/Tuttle may contain two cometesimals characterized by distinct
volatile composition. The relative abundances C2/CN, C2/OH, and CN/OH in
8P/Tuttle (measured at optical/near-UV wavelengths) differ substantially from
the mixing ratios of their potential parents (C2H2/HCN, C2H2/H2O, and HCN/H2O)
found in this work. Based on this comparison, our results do not support C2H2
and HCN being the principal precursors for respectively C2 and CN in Tuttle.
The peculiar native composition observed in 8P/Tuttle (compared to other
comets) provides new strong evidence for chemical diversity in the volatile
materials stored in comet nuclei. We discuss the implications of this diversity
for expected variations in the deuterium enrichment of water among comets.


title:
Center-of-mass motion and cross-channel coupling in time-dependent
  Hartree-Fock theory

abstract:
  We provide a discussion of issues related to the center-of-mass motion and
cross-channel coupling in applications of the time-dependent Hartree-Fock
(TDHF) theory to heavy-ion collisions. We find that the entrance channel
dynamics of a heavy-ion collision as described by TDHF does not seem to be
significantly influenced by these effects, whereas the long-time evolution may
be less reliable.


title: Chiral symmetry breaking beyond BCS and theorem on the width of scalars

abstract:
  We review chiral symmetry breaking at the BCS level, in the framework of
chiral invariant quark models and in the Schwinger-Dyson formalism. We revisit
the pi mass problem beyond the BCS level. We show a theorem on the masses, on
the widths and on the q qbar content of the scalar mesons sigma and f0.


title:
Optical Properties of Ultrashort Semiconducting Single-Walled Carbon
  Nanotube Capsules Down to Sub-10 nm

abstract:
  Single-walled carbon nanotubes (SWNTs) are typically long (>100 nm) and have
been well established as novel quasi one-dimensional systems with interesting
electrical, mechanical, and optical properties. Here, quasi zero-dimensional
SWNTs with finite lengths down to the molecular scale (7.5 nm in average) were
obtained by length separation using a density gradient ultracentrifugation
method. Different sedimentation rates of nanotubes with different lengths in a
density gradient were taken advantage of to sort SWNTs according to length.
Optical experiments on the SWNT fractions revealed that the UV-vis-NIR
absorption and photoluminescence peaks of the ultrashort SWNTs blue-shift up to
30 meV compared to long nanotubes, owing to quantum confinement effects along
the length of ultrashort SWNTs. These nanotube capsules essentially correspond
to SWNT quantum dots.


title: Non-Hermitian Hamiltonians of Lie algebraic type

abstract:
  We analyse a class of non-Hermitian Hamiltonians, which can be expressed
bilinearly in terms of generators of a sl(2,R)-Lie algebra or their isomorphic
su(1,1)-counterparts. The Hamlitonians are prototypes for solvable models of
Lie algebraic type. Demanding a real spectrum and the existence of a well
defined metric, we systematically investigate the constraints these
requirements impose on the coupling constants of the model and the parameters
in the metric operator. We compute isospectral Hermitian counterparts for some
of the original non-Hermitian Hamiltonian. Alternatively we employ a
generalized Bogoliubov transformation, which allows to compute explicitly real
energy eigenvalue spectra for these type of Hamiltonians, together with their
eigenstates. We compare the two approaches.


title: Multiband magnetism and superconductivity in Fe-based compounds

abstract:
  Recent discovery of high T_c superconductivity in Fe-based compounds may have
opened a new pathway to the room temperature superconductivity. The new
materials feature FeAs layers instead of the signature CuO_2 planes of
much-studied cuprates. A model Hamiltonian describing FeAs layers is
introduced, highlighting the crucial role of puckering of As atoms in promoting
d-electron itinerancy and warding off large local-moment magnetism of Fe ions,
the main enemy of superconductivity. Quantum many-particle effects in charge,
spin and multiband channels are explored and a nesting-induced spin
density-wave order is found in the parent compund. We argue that this largely
itinerant antiferromagnetism and high T_c itself are essentially tied to the
multiband nature of the Fermi surface.


title:
Mass formulas for local Galois representations to wreath products and
  cross products

abstract:
  Bhargava proved a formula for counting, with certain weights, degree n etale
extensions of a local field, or equivalently, local Galois representations to
S_n. This formula is motivation for his conjectures about the density of
discriminants of S_n-number fields. We prove there are analogous ``mass
formulas'' that count local Galois representations to any group that can be
formed from symmetric groups by wreath products and cross products,
corresponding to counting towers and direct sums of etale extensions. We obtain
as a corollary that the above mentioned groups have rational character tables.
Our result implies that D_4 has a mass formula for certain weights, but we show
that D_4 does not have a mass formula when the local Galois representations to
D_4 are weighted in the same way as representations to S_4 are weighted in
Bhargava's mass formula.


title: The Effects of Clumps in Explaining X-ray Emission Lines from Hot Stars

abstract:
  It is now well established that stellar winds of hot stars are fragmentary
and that the X-ray emission from stellar winds has a strong contribution from
shocks in winds. Chandra high spectral resolution observations of line profiles
of O and B stars have shown numerous properties that had not been expected.
Here we suggest explanations by considering the X-rays as arising from bow
shocks that occur where the stellar wind impacts on spherical clumps in the
winds. We use an accurate and stable numerical hydrodynamical code to obtain
steady-state physical conditions for the temperature and density structure in a
bow shock. We use these solutions plus analytic approximations to interpret
some major X-ray features: the simple power-law distribution of the observed
emission measure derived from many hot star X-ray spectra and the wide range of
ionization stages that appear to be present in X-ray sources throughout the
winds. Also associated with the adiabatic cooling of the gas around a clump is
a significant transverse velocity for the hot plasma flow around the clumps,
and this can help to understand anomalies associated with observed line widths,
and the differences in widths seen in stars with high and low mass-loss rates.
The differences between bow shocks and the planar shocks that are often used
for hot stars are discussed. We introduce an ``on the shock'' (OTSh)
approximation that is useful for interpreting the X-rays and the consequences
of clumps in hot star winds and elsewhere in astronomy.


title: $d$-Regular graphs of acyclic chromatic index at least $d+2$

abstract:
  An $acyclic$ edge coloring of a graph is a proper edge coloring such that
there are no bichromatic cycles. The \emph{acyclic chromatic index} of a graph
is the minimum number k such that there is an acyclic edge coloring using k
colors and is denoted by $a'(G)$. It was conjectured by Alon, Sudakov and Zaks
  (and earlier by Fiamcik) that $a'(G)\le \Delta+2$, where $\Delta =\Delta(G)$
denotes the maximum degree of the graph. Alon et.al also raised the question
whether the complete graphs of even order are the only regular graphs which
require $\Delta+2$ colors to be acyclically edge colored. In this paper, using
a simple counting argument we observe not only that this is not true, but
infact all d-regular graphs with $2n$ vertices and $d > n$, requires at least
$d+2$ colors. We also show that $a'(K_{n,n}) \ge n+2$, when $n$ is odd using a
more non-trivial argument(Here $K_{n,n}$ denotes the complete bipartite graph
with $n$ vertices on each side). This lower bound for $K_{n,n}$ can be shown to
be tight for some families of complete bipartite graphs and for small values of
$n$. We also infer that for every $d,n$ such that $d \ge 5$, $n \ge 2d + 3$ and
$dn$ even, there exist $d$-regular graphs which require at least $d+2$-colors
to be acyclically edge colored.


title: Introduction to Relational Networks for Classification

abstract:
  The use of computational intelligence techniques for classification has been
used in numerous applications. This paper compares the use of a Multi Layer
Perceptron Neural Network and a new Relational Network on classifying the HIV
status of women at ante-natal clinics. The paper discusses the architecture of
the relational network and its merits compared to a neural network and most
other computational intelligence classifiers. Results gathered from the study
indicate comparable classification accuracies as well as revealed relationships
between data features in the classification data. Much higher classification
accuracies are recommended for future research in the area of HIV
classification as well as missing data estimation.


title:
System and energy dependence of strange and non-strange particle
  correlations in STAR at RHIC

abstract:
  Two-particle high-$p_T$ triggered correlations in $Cu+Cu$ and $Au+Au$
collisions at $\sqrt{s_{NN}}$ = 62 $GeV$ and $\sqrt{s_{NN}}$ = 200 $GeV$ in
STAR at RHIC are presented. The $N_{part}$, $p_T^{associated}$, and
$p_T^{trigger}$ dependence of the yield per trigger in the \textit{Jet} and
\textit{Ridge} components of the near-side is investigated for h, $K^0_S$,
$\Lambda$, and $\Xi$ trigger and associated particles. The system and energy
dependence of these components is a potentially powerful tool to distinguish
between models used to describe their production.


title:
Limit to 2D mobility in modulation-doped GaAs quantum structures: How to
  achieve a mobility of 100 millions

abstract:
  Considering scattering by unintentional background charged impurities and by
charged dopants in the modulation doping layer as well as by GaAs acoustic
phonons, we theoretically consider the practical intrinsic (phonons) and
extrinsic (background and dopants) limits to carrier mobility in modulation
doped AlGaAs-GaAs 2D semiconductor structures. We find that reducing background
impurity density to $10^{12}$ cm$^{-3}$ along with a modulation doping
separation of 1000 \AA or above will achieve a mobility of $100 \times 10^6$
cm$^2$/Vs at a carrier density of $3\times 10^{11}$ cm$^{-2}$ for T=1K. At T=4
(10)K, however, the hard limit to the 2D mobility would be set by acoustic
phonon scattering with the maximum intrinsic mobility being no higher than 22
$(5) \times 10^6$ cm$^2$/Vs. Detailed numerical results are presented as a
function of carrier density, modulation doping distance, and temperature to
provide a quantitative guide to experimental efforts for achieving ultra-high
2D mobilities.


title: Gaussian Processes and Limiting Linear Models

abstract:
  Gaussian processes retain the linear model either as a special case, or in
the limit. We show how this relationship can be exploited when the data are at
least partially linear. However from the perspective of the Bayesian posterior,
the Gaussian processes which encode the linear model either have probability of
nearly zero or are otherwise unattainable without the explicit construction of
a prior with the limiting linear model in mind. We develop such a prior, and
show that its practical benefits extend well beyond the computational and
conceptual simplicity of the linear model. For example, linearity can be
extracted on a per-dimension basis, or can be combined with treed partition
models to yield a highly efficient nonstationary model. Our approach is
demonstrated on synthetic and real datasets of varying linearity and
dimensionality.


title: Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4

abstract:
  Galactic winds are a prime suspect for the metal enrichment of the
intergalactic medium and may have a strong influence on the chemical evolution
of galaxies and the nature of QSO absorption line systems. We use a sample of
1406 galaxy spectra at z~1.4 from the DEEP2 redshift survey to show that
blueshifted Mg II 2796, 2803 A absorption is ubiquitous in starforming galaxies
at this epoch. This is the first detection of frequent outflowing galactic
winds at z~1. The presence and depth of absorption are independent of AGN
spectral signatures or galaxy morphology; major mergers are not a prerequisite
for driving a galactic wind from massive galaxies. Outflows are found in
coadded spectra of galaxies spanning a range of 30x in stellar mass and 10x in
star formation rate (SFR), calibrated from K-band and from MIPS IR fluxes. The
outflows have column densities of order N_H ~ 10^20 cm^-2 and characteristic
velocities of ~ 300-500 km/sec, with absorption seen out to 1000 km/sec in the
most massive, highest SFR galaxies. The velocities suggest that the outflowing
gas can escape into the IGM and that massive galaxies can produce
cosmologically and chemically significant outflows. Both the Mg II equivalent
width and the outflow velocity are larger for galaxies of higher stellar mass
and SFR, with V_wind ~ SFR^0.3, similar to the scaling in low redshift
IR-luminous galaxies. The high frequency of outflows in the star-forming galaxy
population at z~1 indicates that galactic winds occur in the progenitors of
massive spirals as well as those of ellipticals. The increase of outflow
velocity with mass and SFR constrains theoretical models of galaxy evolution
that include feedback from galactic winds, and may favor momentum-driven models
for the wind physics.


title: The Warped Plane of the Classical Kuiper Belt

abstract:
  By numerically integrating the orbits of the giant planets and of test
particles over a period of four billion years, we follow the evolution of the
location of the midplane of the Kuiper belt. The Classical Kuiper belt conforms
to a warped sheet that precesses with a 1.9 Myr period. The present-day
location of the Kuiper belt plane can be computed using linear secular
perturbation theory: the local normal to the plane is given by the theory's
forced inclination vector, which is specific to every semimajor axis. The
Kuiper belt plane does not coincide with the invariable plane, but deviates
from it by up to a few degrees in stable zones. For example, at a semimajor
axis of 38 AU, the local Kuiper belt plane has an inclination of 1.9 deg and a
longitude of ascending node of 149.9 deg when referred to the mean ecliptic and
equinox of J2000. At a semimajor axis of 43 AU, the local plane has an
inclination of 1.9 deg and a nodal longitude of 78.3 deg. Only at infinite
semimajor axis does the Kuiper belt plane merge with the invariable plane,
whose inclination is 1.6 deg and nodal longitude is 107.7 deg. A Kuiper belt
object keeps its inclination relative to the Kuiper belt plane nearly constant,
even while the latter plane departs from the trajectory predicted by linear
theory. The constancy of relative inclination reflects the undamped amplitude
of free oscillation. Current observations of Classical Kuiper belt objects are
consistent with the plane being warped by the giant planets alone, but the
sample size will need to increase by a few times before confirmation exceeds
3-sigma in confidence. In principle, differences between the theoretically
expected plane and the observed plane could be used to infer as yet unseen
masses orbiting the Sun, but carrying out such a program would be challenging.


title: Braided and coboundary monoidal categories

abstract:
  In this expository paper, we discuss and compare the notions of braided and
coboundary monoidal categories. Coboundary monoidal categories are analogues of
braided monoidal categories in which the role of the braid group is replaced by
the cactus group. We focus on the categories of representations of quantum
groups and crystals and explain how while the former is a braided monoidal
category, this structure does not pass to the crystal limit. However, the
categories of representations of quantum groups of finite type also possess the
structure of a coboundary category which does behave well in the crystal limit.
We explain this construction and also a recent interpretation of the coboundary
structure using quiver varieties. This geometric viewpoint allows one to show
that the category of crystals is in fact a coboundary monoidal category for
arbitrary symmetrizable Kac-Moody type.


title: Introduction to Potential Theory via Applications

abstract:
  We introduce the basic concepts related to subharmonic functions and
potentials, mainly for the case of the complex plane and prove the Riesz
decomposition theorem. Beyond the elementary facts of the theory we deviate
slightly from the usual path of exposition and introduce further concepts
alongside with applications. We cover the Dirichlet problem in detail and
illustrate the relations between potential theory and probability by
considering harmonic measure and its relation to Brownian motion. Furthermore
Green's function is introduced and an application to growth of polynomials is
given. Equilibrium measures are motivated by their original development in
physics and we end with a brief discussion of capacity and its relation to
Hausdorff measure.
  We hope that the reader, who is familiar with the main elements of real
analysis, complex analysis, measure theory and some probability theory benefits
from these notes. No new results are presented but we hope that the style of
presentation enables the reader to understand quickly the basic ideas of
potential theory and how it can be used in different contexts.
  The notes can also be used for a short course on potential theory. Therefore
the required prerequisites are described in the Appendix. References are given
where expositions and details can be found; roughly speaking, familiarity with
the basic foundations of real and complex analysis should suffice to proceed
without any background reading.


title:
The radial distribution of type Ia supernovae in early-type galaxies:
  implications for progenitor scenarios

abstract:
  We study the radial distribution of supernova Ia (SNe Ia) in morphologically
selected early-type host galaxies from the Sloan Digital Sky Survey (SDSS) and
discuss its implications for the progenitor systems of SNe Ia. While new
observations of early-type galaxies suggest that they contain small fractions
of young stellar populations, they are also the most likely hosts for long time
delay SNe Ia. We find that there is no statistically significant difference
between the radial distribution of SNe Ia and the light profile of their
early-type host galaxies, which are dominated by old, metal-rich stellar
populations. This confirms the commonly accepted idea that some SN Ia
progenitors have time delays of the order of several Gyr.


title:
Pfaffian statistics through adiabatic transport in the 1D coherent state
  representation

abstract:
  Recent work has shown that the low energy sector of certain quantum Hall
states is adiabatically connected to simple charge-density-wave patterns that
appear, e.g., when the system is deformed into a thin torus. Here it is shown
that the patterns emerging in this limit already determine the non-abelian
statistics of the $\nu=1$ Moore-Read state. Aside from the knowledge of these
patterns, the method only relies on the principle of adiabatic continuity, the
effectively noncommutative geometry in a strong magnetic field, and topological
as well as locality arguments.


title:
PCA detection and denoising of Zeeman signatures in stellar polarised
  spectra

abstract:
  Our main objective is to develop a denoising strategy to increase the signal
to noise ratio of individual spectral lines of stellar spectropolarimetric
observations.
  We use a multivariate statistics technique called Principal Component
Analysis. The cross-product matrix of the observations is diagonalized to
obtain the eigenvectors in which the original observations can be developed.
This basis is such that the first eigenvectors contain the greatest variance.
Assuming that the noise is uncorrelated a denoising is possible by
reconstructing the data with a truncated basis. We propose a method to identify
the number of eigenvectors for an efficient noise filtering.
  Numerical simulations are used to demonstrate that an important increase of
the signal to noise ratio per spectral line is possible using PCA denoising
techniques. It can be also applied for detection of magnetic fields in stellar
atmospheres. We analyze the relation between PCA and commonly used well-known
techniques like line addition and least-squares deconvolution. Moreover, PCA is
very robust and easy to compute.


title:
Long-Time Asymptotics of the Toda Lattice for Decaying Initial Data
  Revisited

abstract:
  The purpose of this article is to give a streamlined and self-contained
treatment of the long-time asymptotics of the Toda lattice for decaying initial
data in the soliton and in the similarity region via the method of nonlinear
steepest descent.


title:
Characterizing right-veering homeomorphisms of the punctured torus via
  the Burau representation

abstract:
  We classify right-veering homeomorphisms of the once-punctured torus using
the Burau representation of the 3-strand braid group. We show that reducible
and periodic mapping classes in B_3 can be identified as right-veering by
consideration of the reduced version of the Burau representation. Given any
element beta in B_3, we give a method to quickly determine its action on the
generators of the fundamental group of the 3-times punctured disk. This action
which determines whether beta is right-veering, left-veering, or neither.


title:
Nonlinear evolution equations for degenerate transverse waves in
  anisotropic elastic solids

abstract:
  Transverse elastic waves behave differently in nonlinear isotropic and
anisotropic media. Quadratically nonlinear coupling in the evolution equations
for wave amplitudes is not possible in isotropic solids, but such a coupling
may occur for certain directions in anisotropic materials. We identify the
expression responsible for the coupling and we derive coupled canonical
evolution equations for transverse wave amplitudes in the case of two-fold and
three-fold symmetry acoustic axes. We illustrate our considerations by examples
for a cubic crystal.


title:
A Simple Method for Rise-Time Discrimination of Slow Pulses from
  Charge-Sensitive Preamplifiers

abstract:
  Performance of a simple method of particle identification via pulse rise time
discrimination is demonstrated for slow pulses from charge-sensitive
preamplifiers with rise times ranging from 10 ns to 500 ns. The method is based
on a comparison of the amplitudes of two pulses, derived from each raw
preamplifier pulse with two amplifiers with largely differing shaping times,
using a fast peak-sensing ADC. For the injected charges corresponding to energy
deposits in silicon detectors of a few tens of MeV, a rise time resolution of
the order of 1 ns can be achieved. The identification method is applicable in
particle experiments involving large-area silicon detectors, but is easily
adaptable to other detectors with a response corresponding to significantly
different pulse rise times for different particle species.


title: Convergence of all-order many-body methods: coupled-cluster study for Li

abstract:
  We present and analyze results of the relativistic coupled-cluster
calculation of energies, hyperfine constants, and dipole matrix elements for
the $2s$, $2p_{1/2}$, and $2p_{3/2}$ states of Li atom. The calculations are
complete through the fourth order of many-body perturbation theory for energies
and through the fifth order for matrix elements and subsume certain chains of
diagrams in all orders. A nearly complete many-body calculation allows us to
draw conclusions on the convergence pattern of the coupled-cluster method. Our
analysis suggests that the high-order many-body contributions to energies and
matrix elements scale proportionally and provides a quantitative ground for
semi-empirical fits of {\em ab inito} matrix elements to experimental energies.


title:
Common Signatures of Statistical Coulomb Fragmentation of Highly Excited
  Nuclei and Phase Transitions in Confined Microcanonical Systems

abstract:
  Characteristic signatures of statistical Coulomb fragmentation of highly
excited nuclear systems were analyzed. It was found that in some important
aspects, they coincide with perceived signatures of phase transitions in
confined hypothetical pseudo-microcanonical systems, thus potentially giving
rise to a false interpretation of experimental observations in terms of phase
transitions. It is demonstrated that the heat capacity as derived based on
experimental observations may show domains of faux negative heat capacity for
the same fundamental reason a faux negative heat capacity appears in
constrained numerical modeling of phase transitions in excited nuclear matter,
the reason being an effective truncation of the microcanonical phase space.
Similarly, selected experimental data may exhibit bimodality apparently in
accordance with the truncated pseudo-microcanonical (but not the true
microcanonical) calculations for confined systems.


title:
Orbital Advection by Interpolation: A Fast and Accurate Numerical Scheme
  for Super-Fast MHD Flows

abstract:
  In numerical models of thin astrophysical disks that use an Eulerian scheme,
gas orbits supersonically through a fixed grid. As a result the time step is
sharply limited by the Courant condition. Also, because the mean flow speed
with respect to the grid varies with position, the truncation error varies
systematically with position. For hydrodynamic (unmagnetized) disks an
algorithm called FARGO has been developed that advects the gas along its mean
orbit using a separate interpolation substep. This relaxes the constraint
imposed by the Courant condition, which now depends only on the peculiar
velocity of the gas, and results in a truncation error that is more nearly
independent of position. This paper describes a FARGO-like algorithm suitable
for evolving magnetized disks. Our method is second order accurate on a smooth
flow and preserves the divergence-free constraint to machine precision. The
main restriction is that the magnetic field must be discretized on a staggered
mesh. We give a detailed description of an implementation of the code and
demonstrate that it produces the expected results on linear and nonlinear
problems. We also point out how the scheme might be generalized to make the
integration of other supersonic/super-fast flows more efficient. Although our
scheme reduces the variation of truncation error with position, it does not
eliminate it. We show that the residual position dependence leads to
characteristic radial variations in the density over long integrations.


title: Regularity of a vector potential problem and its spectral curve

abstract:
  In this note we study a minimization problem for a vector of measures subject
to a prescribed interaction matrix in the presence of external potentials. The
conductors are allowed to have zero distance from each other but the external
potentials satisfy a growth condition near the common points.
  We then specialize the setting to a specific problem on the real line which
arises in the study of certain biorthogonal polynomials (studied elsewhere) and
we prove that the equilibrium measures solve a pseudo-algebraic curve under the
assumption that the potentials are real analytic. In particular the supports of
the equilibrium measures are shown to consist of a finite union of compact
intervals.


title: Superposition-Coded Concurrent Decode-and-Forward Relaying

abstract:
  In this paper, a superposition-coded concurrent decode-and-forward (DF)
relaying protocol is presented. A specific scenario, where the inter-relay
channel is sufficiently strong, is considered. Assuming perfect source-relay
transmissions, the proposed scheme further improves the diversity performance
of previously proposed repetition-coded concurrent DF relaying, in which the
advantage of the inter-relay interference is not fully extracted.


title: Extending the Ehresmann-Schein-Nambooripad Theorem

abstract:
  We extend the `join-premorphisms' part of the Ehresmann-Schein-Nambooripad
Theorem to the case of two-sided restriction semigroups and inductive
categories, following on from a result of Lawson (1991) for the `morphisms'
part. However, it is so-called `meet-premorphisms' which have proved useful in
recent years in the study of partial actions. We therefore obtain an
Ehresmann-Schein-Nambooripad-type theorem for meet-premorphisms in the case of
two-sided restriction semigroups and inductive categories. As a corollary, we
obtain such a theorem in the inverse case.


title:
Quantum Non-locality and Partial Transposition for Continuous-Variable
  Systems

abstract:
  A continuous-variable Bell inequality, valid for an arbitrary number of
observers measuring observables with an arbitrary number of outcomes, was
recently introduced in [Cavalcanti \emph{et al.}, Phys. Rev. Lett. {\bf 99},
210405 (2007)]. We prove that any $n$-mode quantum state violating this
inequality with quadrature measurements necessarily has a negative partial
transposition. Our results thus establish the first link between nonlocality
and bound entanglement for continuous-variable systems.


title: Up to and beyond ninth order in opacity: Radiative energy loss with GLV

abstract:
  A new examination of the GLV all-orders opacity result for radiative energy
loss is presented. The opacity expansion is shown to be a Dyson expansion of a
Schrodinger-like (or diffusion) equation, a form also found in BDMPS-Z-ASW, AMY
and Higher Twist formalisms of radiative energy loss. A new, efficient
numerical evaluation of the GLV all-orders result gives results up to and
beyond ninth order in opacity. This presents a solution to this
Schrodinger-like equation to almost arbitrary accuracy for lengths and
densities applicable at RHIC and LHC. The first order is found to be most
important, although higher orders implemented in a geometry integration will be
needed for quantitative jet tomography.


title:
Hidden Symmetries of Higher Dimensional Black Holes and Uniqueness of
  the Kerr-NUT-(A)dS spacetime

abstract:
  We prove that the most general solution of the Einstein equations with the
cosmological constant which admits a principal conformal Killing-Yano tensor is
the Kerr-NUT-(A)dS metric. Even when the Einstein equations are not imposed,
any spacetime admitting such hidden symmetry can be written in a canonical form
which guarantees the following properties: it is of the Petrov type D, it
allows the separation of variables for the Hamilton-Jacobi, Klein-Gordon, and
Dirac equations, the geodesic motion in such a spacetime is completely
integrable. These results naturally generalize the results obtained earlier in
four dimensions.


title: Hadronic structure from the lattice

abstract:
  In recent years the investigation of hadron structure using lattice
techniques has attracted growing attention. In this talk we give an overview on
recent work with a focus on results for nucleon spectrum and structure from the
QCDSF collaboration.


title: Hamiltonicity thresholds in Achlioptas processes

abstract:
  In this paper we analyze the appearance of a Hamilton cycle in the following
random process. The process starts with an empty graph on n labeled vertices.
At each round we are presented with K=K(n) edges, chosen uniformly at random
from the missing ones, and are asked to add one of them to the current graph.
The goal is to create a Hamilton cycle as soon as possible.
  We show that this problem has three regimes, depending on the value of K. For
K=o(\log n), the threshold for Hamiltonicity is (1+o(1))n\log n /(2K), i.e.,
typically we can construct a Hamilton cycle K times faster that in the usual
random graph process. When K=\omega(\log n) we can essentially waste almost no
edges, and create a Hamilton cycle in n+o(n) rounds with high probability.
Finally, in the intermediate regime where K=\Theta(\log n), the threshold has
order n and we obtain upper and lower bounds that differ by a multiplicative
factor of 3.


title: Error propagation in polarimetric demodulation

abstract:
  The polarization analysis of the light is typically carried out using
modulation schemes. The light of unknown polarization state is passed through a
set of known modulation optics and a detector is used to measure the total
intensity passing the system. The modulation optics is modified several times
and, with the aid of such several measurements, the unknown polarization state
of the light can be inferred. How to find the optimal demodulation process has
been investigated in the past. However, since the modulation matrix has to be
measured for a given instrument and the optical elements can present problems
of repeatability, some uncertainty is present in the elements of the modulation
matrix and/or covariances between these elements. We analyze in detail this
issue, presenting analytical formulae for calculating the covariance matrix
produced by the propagation of such uncertainties on the demodulation matrix,
on the inferred Stokes parameters and on the efficiency of the modulation
process. We demonstrate that, even if the covariance matrix of the modulation
matrix is diagonal, the covariance matrix of the demodulation matrix is, in
general, non-diagonal because matrix inversion is a nonlinear operation. This
propagates through the demodulation process and induces correlations on the
inferred Stokes parameters.


title: Calculation of Superdiffusion for the Chirikov-Taylor Model

abstract:
  It is widely known that the paradigmatic Chirikov-Taylor model presents
enhanced diffusion for specific intervals of its stochasticity parameter due to
islands of stability, which are elliptic orbits surrounding accelerator mode
fixed points. In contrast with normal diffusion, its effect has never been
analytically calculated. Here, we introduce a differential form for the
Perron-Frobenius evolution operator in which normal diffusion and
superdiffusion are treated separately through phases formed by angular wave
numbers. The superdiffusion coefficient is then calculated analytically
resulting in a Schloemilch series with an exponent $\beta=3/2$ for the
divergences. Numerical simulations support our results.


title: Opportunities for TeV Laser Acceleration

abstract:
  A set of ballpark parameters for laser, plasma, and accelerator technologies
that define for electron energies reaching as high as TeV are identified. These
ballpark parameters are carved out from the fundamental scaling laws that
govern laser acceleration, theoretically suggested and experimentally explored
over a wide range in the recent years. In the density regime on the order of
10^{16} cm^{-3}, the appropriate laser technology, we find, matches well with
that of a highly efficient high fluence LD driven Yb ceramic laser. Further,
the collective acceleration technique applies to compactify the beam stoppage
stage by adopting the beam-plasma wave deceleration, which contributes to
significantly enhance the stopping power and energy recovery capability of the
beam. Thus we find the confluence of the needed laser acceleration parameters
dictated by these scaling laws and the emerging laser technology. This may
herald a new technology in the ultrahigh energy frontier.


title:
On Skyrmion semiclassical quantization in the presence of an isospin
  chemical potential

abstract:
  The semiclassical description of Skyrmions at small isospin chemical
potential $\mu_I$ is carefully analyzed. We show that when the calculation of
the energy of a nucleon is performed using the straightforward generalization
of the vacuum sector techniques ($\mu_I=0$), together with the "natural"
assumption $\mu_I = {\cal O} (N_c^0)$, the proton and neutron masses are
nonlinear in $\mu_I$ in the regime $|\mu_I| < m_\pi$. Although these
nonlinearities turn out to be numerically quite small, such a result fails to
strictly agree with the very robust prediction that for those values of $\mui$
the energy excitations above the vacuum are linear in $\mu_I$. The resolution
of this paradox is achieved by studying the realization of the large $N_c$
limit of $QCD$ in the Skyrme model at finite $\mui$. This is done in a
simplified context devoid of the technical complications present in the Skyrme
model but which fully displays the general scaling behavior with $N_c$. The
analysis shows that the paradoxical result appears as a symptom of using the
semi-classical approach beyond its regime of validity and that, at a formal
level, the standard methods for dealing with the Skyrme model are only strictly
justified for states of high isospin $I \sim N_c$.


title: Reductions of integrable lattices

abstract:
  Based on the notion of Darboux-KP chain hierarchy and its invariant
submanifolds we construct some class of constraints compatible with integrable
lattices. Some simple examples are given.


title: Imaging with two spiral diffracting elements intermediated by a pinhole

abstract:
  A pseudoscopic (inverted depth) image made with spiral diffracting elements
intermediated by a pinhole is explained by its symmetry properties. The whole
process is made under common white light illumination and allows the projection
of images. The analysis of this projection demonstrates that the images of two
objects pointing away longitudinally have the main features of standard
pseudoscopic image points. An orthoscopic (normal depth) image has also been
obtained with the breaking of the symmetry conditions.


title:
Network Structure and Dynamics, and Emergence of Robustness by
  Stabilizing Selection in an Artificial Genome

abstract:
  Genetic regulation is a key component in development, but a clear
understanding of the structure and dynamics of genetic networks is not yet at
hand. In this work we investigate these properties within an artificial genome
model originally introduced by Reil. We analyze statistical properties of
randomly generated genomes both on the sequence- and network level, and show
that this model correctly predicts the frequency of genes in genomes as found
in experimental data. Using an evolutionary algorithm based on stabilizing
selection for a phenotype, we show that robustness against single base
mutations, as well as against random changes in initial network states that
mimic stochastic fluctuations in environmental conditions, can emerge in
parallel. Evolved genomes exhibit characteristic patterns on both sequence and
network level.

categories: q-bio.MN cond-mat.dis-nn cs.NE q-bio.GN q-bio.PE


title:
Hall-Littlewood Polynomials, Alcove Walks, and Fillings of Young
  Diagrams

abstract:
  A recent breakthrough in the theory of (type A) Macdonald polynomials is due
to Haglund, Haiman and Loehr, who exhibited a combinatorial formula for these
polynomials in terms of a pair of statistics on fillings of Young diagrams. The
inversion statistic, which is the more intricate one, suffices for specializing
a closely related formula to one for the type A Hall-Littlewood Q-polynomials
(spherical functions on p-adic groups). An apparently unrelated development, at
the level of arbitrary finite root systems, led to Schwer's formula (rephrased
and rederived by Ram) for the Hall-Littlewood P-polynomials of arbitrary type.
The latter formula is in terms of so-called alcove walks, which originate in
the work of Gaussent-Littelmann and of the author with Postnikov on discrete
counterparts to the Littelmann path model. In this paper, we relate the above
developments, by deriving a Haglund-Haiman-Loehr type formula for the
Hall-Littlewood P-polynomials of type A from Ram's version of Schwer's formula
via a "compression" procedure.


title: On Combinatorial Formulas for Macdonald Polynomials

abstract:
  A recent breakthrough in the theory of (type A) Macdonald polynomials is due
to Haglund, Haiman and Loehr, who exhibited a combinatorial formula for these
polynomials in terms of a pair of statistics on fillings of Young diagrams. Ram
and Yip gave a formula for the Macdonald polynomials of arbitrary type in terms
of so-called alcove walks; these originate in the work of Gaussent-Littelmann
and of the author with Postnikov on discrete counterparts to the Littelmann
path model. In this paper, we relate the above developments, by explaining how
the Ram-Yip formula compresses to a new formula, which is similar to the
Haglund-Haiman-Loehr one but contains considerably fewer terms.


title: Intelligent Unmanned Explorer for Deep Space Exploration

abstract:
  asteroids or comets have received remarkable attention in the world. In small
body explorations, especially, detailed in-situ surface exploration by tiny
rover is one of effective and fruitful means and is expected to make strong
contributions towards scientific studies. JAXA ISAS is promoting MUSES C
mission, which is the worlds first sample and return attempt to or from the
near earth asteroid. Hayabusa spacecraft in MUSES C mission took the tiny
rover, which was expected to perform the in-situ surface exploration by
hopping. This paper describes the system design, mobility and intelligence of
the developed unmanned explorer. This paper also presents the ground
experimental results and the flight results.


title: Is SUSY Natural?

abstract:
  Spacetime supersymmetry is widely believed to play an important role in most
fundamental theories of physics, and is usually invoked in order to address
problems of naturalness. In this paper, we examine the question of whether
supersymmetry itself is ``natural'' (i.e., likely to exist as a fundamental
component of nature at high energy scales). Our approach to answering this
question is based on a statistical examination of the heterotic string
landscape, and our conclusion is that supersymmetry is an exceedingly rare
phenomenon. We also find that the likelihood of supersymmetry appearing at the
string scale is dependent on the gauge symmetries present at the string scale,
with certain gauge groups strongly favoring the appearance of N=1 supersymmetry
and others not. This article summarizes several recent papers, yet also
contains some new results. In particular, one new result is that the heterotic
landscape appears to favor either the non-supersymmetric Standard Model or an
N=1 SUSY GUT gauge group at the string scale; by contrast, the opposite
outcomes (namely the MSSM or a non-supersymmetric GUT) are significantly
disfavored.


title: Combinatorial Constructions of Weight Bases: The Gelfand-Tsetlin Basis

abstract:
  This work is part of a project on weight bases for the irreducible
representations of semisimple Lie algebras with respect to which the
representation matrices of the Chevalley generators are given by explicit
formulas. In the case of sl_n, the celebrated Gelfand-Tsetlin basis is the only
such basis known. Using the setup of supporting graphs developed by Donnelly,
we present a simple combinatorial proof of the Gelfand-Tsetlin formulas based
on a rational function identity. Some properties of the Gelfand-Tsetlin basis
are derived via an algorithm for solving certain equations on the lattice of
semistandard Young tableaux.


title: Energy band of graphene ribbons under the tensile force

abstract:
  According to the tight-binding approximation, we investigate the electronic
structures of graphene ribbons with zigzag shaped edges (ZGRs) and armchair
shaped edges (AGRs) drawn by the tensile force, and obtain the analytic
relations between the energy bands of pi-electrons in ZGR, AGR and the tensile
force based on only considering the nearest-neighbor interaction and the
hydrogen-like atomic wave function is considered as pi-electron wave function.
Importantly, we find the tensile force can open an energy gap at the K point
for ZGR and AGR, and the force perpendicular to the zigzag edges can open
energy gap more easily besides the gap values of ZGR and AGR at the K point
both increase as the tensile force increases.


title: Minimal Open Strings

abstract:
  We study FZZT-branes and open string amplitudes in (p,q) minimal string
theory. We focus on the simplest boundary changing operators in two-matrix
models, and identify the corresponding operators in worldsheet theory through
the comparison of amplitudes. Along the way, we find a novel linear relation
among FZZT boundary states in minimal string theory. We also show that the
boundary ground ring is realized on physical open string operators in a very
simple manner, and discuss its use for perturbative computation of higher open
string amplitudes.


title: Yamabe flow, conformal gravity and spacetime foam

abstract:
  It is shown that 3D part of a spherically symmetric solution in conformal
Weyl gravity interacting with Maxwell electrodynamics is a Yamabe flow as well.
The Yamabe flow describes the transition from a horn of an initial wormhole to
a 3D Euclidean space both filled with a radial electric field. It is supposed
that such transition may describe appearing/disappearing quantum wormholes in a
spacetime foam.


title:
Monitoring the Thermal Power of Nuclear Reactors with a Prototype Cubic
  Meter Antineutrino Detector

abstract:
  In this paper, we estimate how quickly and how precisely a reactor's
operational status and thermal power can be monitored over hour to month time
scales, using the antineutrino rate as measured by a cubic meter scale
detector. Our results are obtained from a detector we have deployed and
operated at 25 meter standoff from a reactor core. This prototype can detect a
prompt reactor shutdown within five hours, and monitor relative thermal power
to three percent within seven days. Monitoring of short-term power changes in
this way may be useful in the context of International Atomic Energy Agency's
(IAEA) Reactor Safeguards Regime, or other cooperative monitoring regimes.


title:
Effect of sigma electrons on the pi-electron behavior in single-wall
  carbon nanotubes

abstract:
  The hybrid orbitals of single-wall carbon nanotubes are given according to
the structure of the nanotube. Because the energy levels of these hybrid
orbitals are close to each other, the sigma-orbitals will affect the behavior
of the pi-electrons, which is called the scattering of pi- electrons. This
scattering effect is taken into account in the nanotube and the local wave
function of pi-electrons is constructed, which is called the extended Wannier
function. In the Wannier representation, the electronic hopping energies and
the energy gap of the tubes (9,0) and (9,9) are calculated. Our results show
that the band gap of the tubes increases in direct ratio with the scattering
coefficients of sigma-orbitals and this scattering is able to enhance the
localization of pi-electrons.


title: Running a Quantum Circuit at the Speed of Data

abstract:
  We analyze circuits for a number of kernels from popular quantum computing
applications, characterizing the hardware resources necessary to take ancilla
preparation off the critical path. The result is a chip entirely dominated by
ancilla generation circuits. To address this issue, we introduce optimized
ancilla factories and analyze their structure and physical layout for ion trap
technology. We introduce a new quantum computing architecture with highly
concentrated data-only regions surrounded by shared ancilla factories. The
results are a reduced dependence on costly teleportation, more efficient
distribution of generated ancillae and more than five times speedup over
previous proposals.


title: Ising models on locally tree-like graphs

abstract:
  We consider ferromagnetic Ising models on graphs that converge locally to
trees. Examples include random regular graphs with bounded degree and uniformly
random graphs with bounded average degree. We prove that the "cavity"
prediction for the limiting free energy per spin is correct for any positive
temperature and external field. Further, local marginals can be approximated by
iterating a set of mean field (cavity) equations. Both results are achieved by
proving the local convergence of the Boltzmann distribution on the original
graph to the Boltzmann distribution on the appropriate infinite random tree.

categories: math.PR cond-mat.stat-mech math-ph math.MP


title: Complete conditions for legitimate Wigner distributions

abstract:
  Given a real-valued phase-space function, it is a nontrivial task to
determine whether it corresponds to a Wigner distribution for a physically
acceptable quantum state. This topic has been of fundamental interest for long,
and in a modern application, it can be related to the problem of entanglement
detection for multi-mode cases. In this paper, we present a hierarchy of
complete conditions for a physically realizable Wigner distribution. Our
derivation is based on the normally-ordered expansion, in terms of annihilation
andcreation operators, of the quasi-density operator corresponding to the
phase-space function in question. As a by-product, it is shown that the
phase-space distributions with elliptical symmetry can be readily diagonalized
in our representation, facilitating the test of physical realizability. We also
illustrate how the current formulation can be connected to the detection of
bipartite entanglement for continuous variables.


title:
Representations of Aut(A(Gamma)) acting on homogeneous components of
  A(Gamma) and A(Gamma) dual

abstract:
  In this paper we will study the structure of algebras A(Gamma) associated to
two directed, layered graphs Gamma. These are algebras associated with Hasse
graphs of n-gons and the algebras Q_n related to pseudoroots of noncommutative
polynomials. We will find the filtration preserving automorphism group of these
algebras and then we will find the multiplicities of the irreducible
representations of Aut(A(Gamma)) acting on the homogeneous components of
A(Gamma) and A(Gamma) dual.


title:
Can a chaos term in the QCD evolution equation restrain high-energy
  collider physics?

abstract:
  We indicate that the random aperiodic oscillation of the gluon distributions
in a modified BFKL equation has the positive Lyapunov exponents. This first
example of chaos in QCD evolution equations, raises the sudden disappearance of
the gluon distributions at a critical small value of the Bjorken variable $x$
and may stop the increase of the new particle events in a ultra high energy
hadron collider.


title: On the contribution of nearby sources to the observed cosmic-ray nuclei

abstract:
  The presence of nearby discrete cosmic-ray (CR) sources can lead to many
interesting effects on the observed properties of CRs. In this paper, we study
about the possible effects on the CR primary and secondary spectra and also the
subsequent effects on the CR secondary-to-primary ratios. For the study, we
assume that CRs undergo diffusive propagation in the Galaxy and we neglect the
effect of convection, energy losses and reacceleration. In our model, we assume
that there exists a uniform and continuous distribution of CR sources in the
Galaxy generating a stationary CR background at the Earth. In addition, we also
consider the existence of some nearby sources which inject CRs in a discrete
space-time model. Assuming a constant CR source power throughout the Galaxy,
our study has found that the presence of nearby supernova remnants (SNRs)
produces noticeable variations in the primary fluxes mainly above ~ 100 GeV/n,
if CRs are assumed to be released instantaneously after the supernova
explosion. The variation reaches a value of ~ 45% at around 10^5 GeV/n. Respect
to earlier studies, the variation in the case of the secondaries is found to be
almost negligible. We also discuss about the possible effects of the different
particle release times from the SNRs. For the particle release time of ~ 10^5
yr, predicted by the diffusive shock acceleration theories in SNRs, we have
found that the presence of the nearby SNRs hardly produces any significant
effects on the CRs at the Earth.


title: Ferromagnetic Ising spin systems on the growing random tree

abstract:
  We analyze the ferromagnetic Ising model on a scale-free tree; the growing
random network model with the linear attachment kernel $A_k=k+\alpha$
introduced by [Krapivsky et al.: Phys. Rev. Lett. {\bf 85} (2000) 4629-4632].
We derive an estimate of the divergent temperature $T_s$ below which the
zero-field susceptibility of the system diverges. Our result shows that $T_s$
is related to $\alpha$ as $\tanh(J/T_s)=\alpha/[2(\alpha+1)]$, where $J$ is the
ferromagnetic interaction. An analysis of exactly solvable limit for the model
and numerical calculation support the validity of this estimate.


title:
On the Inhibition of Linear Absorption in Opaque Materials Using
  Phase-Locked Harmonic Generation

abstract:
  We theoretically predict and experimentally demonstrate inhibition of linear
absorption for phase and group velocity mismatched second and third harmonic
generation in strongly absorbing materials, GaAs in particular, at frequencies
above the absorption edge. A 100-fs pump pulse tuned to 1300nm generates 650nm
and 435nm second and third harmonic pulses that propagate across a 450
micron-thick GaAs substrate without being absorbed. We attribute this to a
phase-locking mechanism that causes the pump to trap the harmonics and to
impress them with its dispersive properties.


title: Jet fragmentation and gauge/string duality

abstract:
  We consider an analog of e^+e^- annihilation in gauge theories which have a
dual string description in asymptotically AdS_5 space and discuss the nature of
jet fragmentation. We construct the timelike anomalous dimension which governs
the scale dependence of the fragmentation function. In the limit of infinite 't
Hooft coupling, the average multiplicity rises linearly with the energy and the
inclusive spectrum is peaked at the kinematical boundary.


title: Magnetic-Field Control of Quantum Critical Points of Valence Transition

abstract:
  We study the mechanism how critical end points of first-order valence
transitions are controlled by a magnetic field. We show that the critical
temperature is suppressed to be a quantum critical point (QCP) by a magnetic
field and unexpectedly the QCP exhibits nonmonotonic field dependence in the
ground-state phase diagram, giving rise to emergence of metamagnetism even in
the intermediate valence-crossover regime. The driving force of the
field-induced QCP is clarified to be cooperative phenomena of Zeeman effect and
Kondo effect, which create a distinct energy scale from the Kondo temperature.
This mechanism explains peculiar magnetic response in CeIrIn5 and metamagnetic
transition in YbXCu4 for X=In as well as sharp contrast between X=Ag and Cd.


title: Twisted Fourier-Mukai number of a K3 surface

abstract:
  We give a counting formula for the twisted Fourier-Mukai partners of a
projective K3 surface. As an application, we describe all twisted Fourier-Mukai
partners of a projective K3 surface of Picard number 1.


title: Spin-transfer torque in magnetic tunnel junctions: Scattering theory

abstract:
  We study the bias-dependent spin-transfer torque in magnetic tunnel junctions
in the Stoner model by scattering theory. We show that the in-plane
(Slonczewski type) torque vanishes and subsequently reverses its direction when
the bias voltage becomes larger or the barrier wider than material and
device-dependent critical values. We are able to reproduce the magnitude and
the bias dependence of measured in-plane and out-of-plane torques using
realistic parameters. The condition for the vanishing torque is summarized by a
phase diagram depending on the applied bias and barrier width, which is
explained in terms of an interface spin polarization and the electron focusing
by the barrier. Quantum size effects in the spin-transfer torque are predicted
as a function of the thickness of a normal metal layer inserted between the
ferromagnet and tunnel barrier.


title: Non-equilibrium Relaxation Analysis on Two-dimensional Melting

abstract:
  The melting transition in the hard-disk system is considered. Non-equilibrium
relaxation analysis of the six-fold bond-orientational order parameter has been
carried out. The critical point between the hexatic and the fluid phase is
determined on the basis of the dynamic scaling hypothesis. The value of the
critical exponent $\eta$ is determined from the fluctuation of the order
parameter at the criticality as $\eta = 0.25(2)$ which is consistent with the
prediction by the Kosterlitz-Thouless-Halperin-Nelson-Young theory.


title:
Structural shrinkage of nonparametric spectral estimators for
  multivariate time series

abstract:
  In this paper we investigate the performance of periodogram based estimators
of the spectral density matrix of possibly high-dimensional time series. We
suggest and study shrinkage as a remedy against numerical instabilities due to
deteriorating condition numbers of (kernel) smoothed periodogram matrices.
Moreover, shrinking the empirical eigenvalues in the frequency domain towards
one another also improves at the same time the Mean Squared Error (MSE) of
these widely used nonparametric spectral estimators. Compared to some existing
time domain approaches, restricted to i.i.d. data, in the frequency domain it
is necessary to take the size of the smoothing span as "effective or local
sample size" into account. While B\"{o}hm and von Sachs (2007) proposes a
multiple of the identity matrix as optimal shrinkage target in the absence of
knowledge about the multidimensional structure of the data, here we consider
"structural" shrinkage. We assume that the spectral structure of the data is
induced by underlying factors. However, in contrast to actual factor modelling
suffering from the need to choose the number of factors, we suggest a
model-free approach. Our final estimator is the asymptotically MSE-optimal
linear combination of the smoothed periodogram and the parametric estimator
based on an underfitting (and hence deliberately misspecified) factor model. We
complete our theoretical considerations by some extensive simulation studies.
In the situation of data generated from a higher-order factor model, we compare
all four types of involved estimators (including the one of B\"{o}hm and von
Sachs (2007)).


title:
Optical polarimetric study of open clusters: Distribution of
  Interstellar matter towards NGC 654

abstract:
  We present new B, V and R linear polarimetric observations for 61 stars
towards the region of the young open cluster NGC 654. In this study we found
evidence for the presence of at least two layers of dust along the line of
sight to the cluster. The distances to the two dust layers are estimated to be
~ 200 pc and ~ 1 kpc which are located much closer to the Sun than the cluster
(~ 2.4 kpc). Both the dust layers have their local magnetic field orientation
nearly parallel to the direction of the Galactic plane. The foreground dust
layer is found to have a ring morphology with the central hole coinciding with
the center of the cluster. The foreground dust grains are suggested to be
mainly responsible for both the observed differential reddening and the
polarization towards the cluster.


title: An Affine-invariant Time-dependent Triangulation of Spatio-temporal Data

abstract:
  In the geometric data model for spatio-temporal data, introduced by Chomicki
and Revesz, spatio-temporal data are modelled as a finite collection of
triangles that are transformed by time-dependent affinities of the plane. To
facilitate querying and animation of spatio-temporal data, we present a normal
form for data in the geometric data model. We propose an algorithm for
constructing this normal form via a spatio-temporal triangulation of geometric
data objects. This triangulation algorithm generates new geometric data objects
that partition the given objects both in space and in time. A particular
property of the proposed partition is that it is invariant under time-dependent
affine transformations, and hence independent of the particular choice of
coordinate system used to describe he spatio-temporal data in. We can show that
our algorithm works correctly and has a polynomial time complexity (of
reasonably low degree in the number of input triangles and the maximal degree
of the polynomial functions that describe the transformation functions). We
also discuss several possible applications of this spatio-temporal
triangulation.


title:
The Effect of Structural Diversity of an Ensemble of Classifiers on
  Classification Accuracy

abstract:
  This paper aims to showcase the measure of structural diversity of an
ensemble of 9 classifiers and then map a relationship between this structural
diversity and accuracy. The structural diversity was induced by having
different architectures or structures of the classifiers The Genetical
Algorithms (GA) were used to derive the relationship between diversity and the
classification accuracy by evolving the classifiers and then picking 9
classifiers out on an ensemble of 60 classifiers. It was found that as the
ensemble became diverse the accuracy improved. However at a certain diversity
measure the accuracy began to drop. The Kohavi-Wolpert variance method is used
to measure the diversity of the ensemble. A method of voting is used to
aggregate the results from each classifier. The lowest error was observed at a
diversity measure of 0.16 with a mean square error of 0.274, when taking 0.2024
as maximum diversity measured. The parameters that were varied were: the number
of hidden nodes, learning rate and the activation function.


title:
STAR's Measurement of Energy and System Size Dependence of K/$\pi$
  Fluctuations at RHIC

abstract:
  Strangeness enhancement has been predicted to be one of the signatures of the
formation of the quark gluon plasma (QGP) and event-by-event fluctuations of
strangeness may reveal the nature of such a phase transition. We report results
for $K/\pi$ fluctuations from Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 and 200 GeV and
Au+Au collisions at $\sqrt{s_{NN}}$ = 62.4, 130 and 200 GeV using the STAR
detector at the Relativistic Heavy Ion Collider. We compare our results with
the results observed in central Pb+Pb collisions at SPS energies at
$\sqrt{s_{NN}}$ = 6.3, 7.6, 8.8, 12.3, and 17.3 GeV. We observe the fluctuation
strength measured at the highest SPS energy point by the NA49 collaboration in
Pb+Pb collisions is similar to our results in Cu+Cu and Au+Au collisions. We
also compare our results with HIJING, a statistical hadronization model and a
multi-phase transport model.


title:
Mass Measurements and Implications for the Energy of the High-Spin
  Isomer in 94Ag

abstract:
  Nuclides in the vicinity of 94Ag have been studied with the Penning trap mass
spectrometer JYFLTRAP at the Ion-Guide Separator On-Line. The masses of the
two-proton-decay daughter 92Rh and the beta-decay daughter 94Pd of the
high-spin isomer in 94Ag have been measured, and the masses of 93Pd and 94Ag
have been deduced. When combined with the data from the one-proton or
two-proton-decay experiments, the results lead to contradictory mass excess
values for the high-spin isomer in 94Ag, -46370(170) or -44970(100) keV,
corresponding to excitation energies of 6960(400) or 8360(370) keV,
respectively.


title: Lattice Problems, Gauge Functions and Parameterized Algorithms

abstract:
  Given a k-dimensional subspace M\subseteq \R^n and a full rank integer
lattice L\subseteq \R^n, the \emph{subspace avoiding problem} SAP is to find a
shortest vector in L\setminus M. Treating k as a parameter, we obtain new
parameterized approximation and exact algorithms for SAP based on the AKS
sieving technique. More precisely, we give a randomized
$(1+\epsilon)$-approximation algorithm for parameterized SAP that runs in time
2^{O(n)}.(1/\epsilon)^k, where the parameter k is the dimension of the subspace
M. Thus, we obtain a 2^{O(n)} time algorithm for \epsilon=2^{-O(n/k)}. We also
give a 2^{O(n+k\log k)} exact algorithm for the parameterized SAP for any
\ell_p norm.
  Several of our algorithms work for all gauge functions as metric with some
natural restrictions, in particular for all \ell_p norms. We also prove an
\Omega(2^n) lower bound on the query complexity of AKS sieving based exact
algorithms for SVP that accesses the gauge function as oracle.


title: Magnetism of quantum dot clusters: A Hubbard model study

abstract:
  Magnetic properties of two and three-dimensional clusters of quantum dots are
studied with exact diagonalization of a generalized Hubbard model. We study the
weak coupling limit, where the electrons interact only within a quantum dot and
consider cases where the second or third harmonic oscillator shell is partially
filled. The results show that in the case of half-filled shell the magnetism is
determined by the antiferromagnetic Heisenberg model with spin 1/2, 1 or 3/2,
depending on the number of electrons in the open shell. For other fillings the
system in most cases favors a large total spin, indicating a ferromagnetic
coupling between the dots.


title: A revision of the Generalized Uncertainty Principle

abstract:
  The Generalized Uncertainty Principle arises from the Heisenberg Uncertainty
Principle when gravity is taken into account, so the leading order correction
to the standard formula is expected to be proportional to the gravitational
constant $G_N = L_{Pl}^2$. On the other hand, the emerging picture suggests a
set of departures from the standard theory which demand a revision of all the
arguments used to deduce heuristically the new rule. In particular, one can now
argue that the leading order correction to the Heisenberg Uncertainty Principle
is proportional to the first power of the Planck length $L_{Pl}$. If so, the
departures from ordinary quantum mechanics would be much less suppressed than
what is commonly thought.


title: Inclusive gluon production in the dipole approach: AGK cutting rules

abstract:
  We consider single gluon production in the dipole model and reproduce the
result of Kovchegov and Tuchin for the adjoint (gluonic) dipole structure of
the inclusive cross section. We show the validity of the adjoint dipole
structure to any order of evolution deriving and solving the non-linear
evolution for the non-diagonal cross section of a dipole scattering off the
target. The form of the solution to this equation restores the dipole
interpretation for non-diagonal cross sections, that appear in gluon
production. Using this formalism, we analyse the single inclusive production
cross section in terms of the contributions of different multiplicities, and we
derive the Abramovskii-Gribov-Kancheli(AGK) cutting rules for two Pomeron
exchange. The cutting rules, which were found in this formalism, fully
reproduce the original AGK rules for the total cross section. However, for the
case of gluon production, the AGK rules are violated already for one gluon
emission from the vertex.


title: Batalin-Vilkovisky coalgebra of string topology

abstract:
  We show that the reduced Hochschild homology of a DG open Frobenius algebra
has the natural structure of a Batalin-Vilkovisky coalgebra, and the reduced
cyclic homology has the natural structure of a gravity coalgebra. This gives an
algebraic model for a Batalin-Vilkovisky coalgebra structure on the reduced
homology of the free loop space of a simply connected closed oriented manifold,
and a gravity coalgebra structure on the reduced equivariant homology.


title:
Study of improving nano-contouring performance by employing
  cross-coupling controller

abstract:
  For the tracking stage path planning, we design a two-axis cross-coupling
control system which uses the PI controller to compensate the contour error
between axes. In this paper, the stage adoptive is designed by our laboratory
(Precision Machine Center of National Formosa University). The cross-coupling
controller calculates the actuating signal of each axis by combining multi-axes
position error. Hence, the cross-coupling controller improves the stage
tracking ability and decreases the contour error. The experiments show
excellent stage motion. This finding confirms that the proposed method is a
powerful and efficient tool for improving stage tracking ability. Also found
were the stages tracking to minimize contour error of two types circular to
approximately 25nm.


title: The Numerical Control Design for a Pair of Dubins Vehicles

abstract:
  In this paper, a model of a pair of Dubins vehicles is considered. The
vehicles move from an initial position and orientation to final position and
orientation. A long the motion, the two vehicles are not allowed to collide
however the two vehicles cant to far each other. The optimal control of the
vehicle is found using the Pontryagins Maximum Principle (PMP). This PMP leads
to a Hamiltonian system consisting of a system of differential equation and its
adjoint. The originally differential equation has initial and final condition
but the adjoint system doesn't have one. The classical difficulty is solved
numerically by the greatest gradient descent method. Some simulation results
are presented in this paper.


title: Strong colour fields and cosmic ray showers at ultra-high energies

abstract:
  We argue that the increase of the ratio baryon/meson due to the presence of
strong colour fields and percolation in ultra-high energy hadronic collisions,
helps to explain some of the global features of ultra-high energy cosmic ray
cascades at E>10^18 eV and, in particular the observed excess in the number of
muons with respect to current models of hadronic interactions. A reasonable
agreement with the small value and slope of the average depth of shower maximum
Xmax vs shower energy -- as seen in data collected at the Pierre Auger
Observatory -- can be obtained with a fast increase of the p-Air production
cross-section compatible with the Froissart bound.


title: Simulation of Dynamic Yaw Stability Derivatives of a Bird Using CFD

abstract:
  Simulation results on dynamic yaw stability derivatives of a gull bird by
means of computational fluid dynamics are presented. Two different kinds of
motions are used for determining the dynamic yaw stability derivatives CNr and
CNbeta . Concerning the first one, simple lateral translation and yaw rotary
motions in yaw are considered. The second one consists of combined motions. To
determine dynamic yaw stability derivatives of the bird, the simulation of an
unsteady flow with a bird model showing a harmonic motion is performed. The
unsteady flow solution for each time step is obtained by solving unsteady Euler
equations based on a finite volume approach for a smaller reduced frequency.
Then, an evaluation of unsteady forces and moments for one cycle is conducted
using harmonic Fourier analysis. The results on the dynamic yaw stability
derivatives for both simulations of the model motion show a good agreement.


title:
Wavelet Based Iterative Learning Control with Fuzzy PD Feedback for
  Position Tracking of A Pneumatic Servo System

abstract:
  In this paper, a wavelet-based iterative learning control (WILC) scheme with
Fuzzy PD feedback is presented for a pneumatic control system with nonsmooth
nonlinearities and uncertain parameters. The wavelet transform is employed to
extract the learnable dynamics from measured output signal before it can be
used to update the control profile. The wavelet transform is adopted to
decompose the original signal into many low-resolution signals that contain the
learnable and unlearnable parts. The desired control profile is then compared
with the learnable part of the transformed signal. Thus, the effects from
unlearnable dynamics on the controlled system can be attenuated by a Fuzzy PD
feedback controller. As for the rules of Fuzzy PD controller in the feedback
loop, a genetic algorithm (GA) is employed to search for the inference rules of
optimization. A proportional-valve controlled pneumatic cylinder actuator
system is used as the control target for simulation. Simulation results have
shown a much-improved positiontracking performance.


title: Positive Real Synthesis of Networked Control System An LMI Approach

abstract:
  This paper presents the positive real analysis and synthesis for Networked
Control Systems (NCS) in discrete time. Based on the definition of passivity,
the sufficient condition of NCS is given by stochastic Lyapunov functional. The
controller via state feedback is designed to guarantee the stability of NCS and
closed-loop positive realness. It is shown that a mode-dependent positive real
controller exists if a set of coupled linear matrix inequalities has solutions.
The controller can be then constructed in terms of the solutions.


title: On Hamiltonians Generating Optimal-Speed Evolutions

abstract:
  We present a simple derivation of the formula for the Hamiltonian operator(s)
that achieve the fastest possible unitary evolution between given initial and
final states. We discuss how this formula is modified in pseudo-Hermitian
quantum mechanics and provide an explicit expression for the most general
optimal-speed quasi-Hermitian Hamiltonian. Our approach allows for an explicit
description of the metric- (inner product-) dependence of the lower bound on
the travel time and the universality (metric-independence) of the upper bound
on the speed of unitary evolutions.


title: Some Multi-Quark Potentials, Pseudo-Potentials and AdS/QCD

abstract:
  The static three-quark potential and pseudo-potential of a pure SU(3) gauge
theory are studied in a five-dimensional framework known as AdS/QCD. The
results support the Y-ansatz for the baryonic area law. A comparison with the
quark-antiquark calculations shows the universality of the string tension as
well as the spatial string tension. We also discuss extensions to SU(N) gauge
theories.


title:
Analysis of Stability, Response and LQR Controller Design of a Small
  Scale Helicopter Dynamics

abstract:
  This paper presents how to use feedback controller with helicopter dynamics
state space model. A simplified analysis is presented for controller design
using LQR of small scale helicopters for axial and forward flights. Our
approach is simple and gives the basic understanding about how to develop
controller for solving the stability of linear helicopter flight dynamics.


title:
Numerical Method of Lines for the Relaxational Dynamics of Nematic
  Liquid Crystals

abstract:
  We propose an efficient numerical scheme, based on the method of lines, for
solving the Landau-de Gennes equations describing the relaxational dynamics of
nematic liquid crystals. Our method is computationally easy to implement,
balancing requirements of efficiency and accuracy. We benchmark our method
through the study of the following problems: the isotropic-nematic interface,
growth of nematic droplets in the isotropic phase and the kinetics of
coarsening following a quench into the nematic phase. Our results, obtained
through solutions of the full coarse-grained equations of motion with no
approximations, provide a stringent test of the de Gennes ansatz for the
isotropic - nematic interface, illustrate the anisotropic character of droplets
in the nucleation regime and validate dynamical scaling in the coarsening
regime.


title:
Design and control of dynamical quantum processes in ortho para H2
  conversion on surfaces

abstract:
  We present here a novel, cost-effective method for increasing and controlling
the ortho para H2 (o p H2) conversion yield. First, we invoke two processes
derived from fundamental, surface science insights, based on the effect of
molecular orientation on the hydrogen solid surface reaction, i.e., dynamical
quantum filtering and steering, and apply them to enhance the o p H2 conversion
yield. Second, we find an important factor that can significantly influence the
yield i.e., inhomogeneity of spin density distribution. This factor gives us a
promising possibility to increase the yield and to find the best catalyst e.g.,
design of materials that can function as catalysts for the o p H2 conversion.


title:
STAR results on medium properties and response of the medium to
  energetic partons

abstract:
  We report new STAR results on the consequences of highly energetic partons
propagating through the medium formed in heavy ion collisions using
correlations as an experimental probe. The recent results providing insights
about color factor effects and path length dependence of parton energy loss,
system size dependence of di-hadron fragmentation functions, conical emission
and ridge formation in heavy ion collisions are presented.


title:
Molecular hydrogen in the circumstellar environments of Herbig Ae/Be
  stars probed by FUSE

abstract:
  We observed molecular hydrogen around a sample of pre-main sequence stars in
order to better characterize their gaseous CS environments. We analyzed the
FUSE (Far Ultraviolet Spectroscopic Explorer) spectra of a sample of Herbig
Ae/Be stars (HAeBes) covering a broad spectral range, including the
main-sequence A5 star Beta-Pictoris. To better diagnose the origin of the
detected H2 and its excitation conditions, we used a model of a
photodissociation region. Our analysis demonstrates that the excitation of H2
is clearly different around most of the HAeBes compared to the interstellar
medium. Moreover, the characteristics of H2 around Herbig Ae and Be stars give
evidence for different excitation mechanisms. For the most massive stars of our
sample (B8 to B2 type), the excitation diagrams are reproduced well by a model
of photodissociation regions (PDR). Our results favor an interpretation in
terms of large CS envelopes, remnants of the molecular clouds in which the
stars were formed. On the other hand, the group of Ae stars (later than B9
type) known to possess disks is more inhomogeneous. In most cases, when CS H2
is detected, the lines of sight do not pass through the disks. The excitation
conditions of H2 around Ae stars cannot be reproduced by PDR models and
correspond to warm and/or hot excited media very close to the stars. In
addition, no clear correlation has been found between the ages of the stars and
the amount of circumstellar H2. Our results suggest structural differences
between Herbig Ae and Be star environments. Herbig Be stars do evolve faster
than Ae stars, and consequently, most Herbig Be stars are younger than Ae ones
at the time we observe them. It is thus more likely to find remnants of their
parent cloud around them.


title:
Topological low-energy modes in N=0 Landau levels of graphene: a
  possibility of a quantum-liquid ground state

abstract:
  We point out that the zero-energy Landau level of Dirac fermions in graphene
can be, in the presence of a repulsive electron-electron interaction, split
into two (levels) associated with a "bond ordering" formation having a "Kekule
pattern", which respects the chiral symmetry. Since the Kekule pattern has a
three-fold degeneracy, domain structures are implied, for which we show that
in-gap states localized along the domain boundaries exist as topological
states. Based on this a possibility of a quantum-liquid ground state of
graphene in magnetic fields is discussed.


title:
Crystal chemical simulation of superconductors on the basis of oxide and
  intermetallic layers

abstract:
  Simulation of 'hybrid' superconductors of 3d-, 4d- and 5d-transition elements
consisting of two different superconducting fragments located between
positively charged ions planes - B'O2 oxide planes and B2C2 intermetallic
layers - has been performed on the basis of the structure of Sr2Mn3As2O2
(A2(B2C2)(B'O2)). The oxide planes are similar to those of CuO2 in
high-temperature superconducting cuprates while the intermetallic layers - to
those of Ni2B2 in low-temperature superconducting borocarbides RNi2B2C and
Fe2As2 layers in high-temperature superconducting oxypnictides RFeAsO1-xFx.


title:
Conjugacy of P-configurations and nonlinear solutions to a certain
  conditional Cauchy equation

abstract:
  We study the connection between conjugations of a special kind of dynamical
systems, called P-configurations, and solutions to homogeneous Cauchy type
functional equations. We find that any two regular P-configurations are
conjugate by a homeomorphism, but cannot be conjugate by a diffeomorphism. This
leads us to the following conclusion (resolving an open problem posed by
Paneah): there exist continuous nonlinear solutions to the functional equation:
f(t) = f((t+1)/2) + f((t-1)/2), t \in [-1,1] .