title:
Euler-Bernoulli beams from a symmetry standpoint-characterization of
  equivalent equations

abstract:
  We completely solve the equivalence problem for Euler-Bernoulli equation
using Lie symmetry analysis. We show that the quotient of the symmetry Lie
algebra of the Bernoulli equation by the infinite-dimensional Lie algebra
spanned by solution symmetries is a representation of one of the following Lie
algebras: $2A_1$, $A_1\oplus A_2$, $3A_1$, or $A_{3,3}\oplus A_1$. Each
quotient symmetry Lie algebra determines an equivalence class of
Euler-Bernoulli equations. Save for the generic case corresponding to arbitrary
lineal mass density and flexural rigidity, we characterize the elements of each
class by giving a determined set of differential equations satisfied by
physical parameters (lineal mass density and flexural rigidity). For each
class, we provide a simple representative and we explicitly construct
transformations that maps a class member to its representative. The maximally
symmetric class described by the four-dimensional quotient symmetry Lie algebra
$A_{3,3}\oplus A_1$ corresponds to Euler-Bernoulli equations homeomorphic to
the uniform one (constant lineal mass density and flexural rigidity) . We
rigorously derive some non-trivial and non-uniform Euler-Bernoulli equations
reducible to the uniform unit beam. Our models extend and emphasize the
symmetry flavor of Gottlieb's iso-spectral beams (Proceedings of the Royal
Society London A 413 (1987) 235-250)


title:
Power-law Signatures and Patchiness in Genechip Oligonucleotide
  Microarrays

abstract:
  . Genechip oligonucleotide microarrays have been used widely for
transcriptional profiling of a large number of genes in a given paradigm. Gene
expression estimation precedes biological inference and is given as a complex
combination of atomic entities on the array called probes. These probe
intensities are further classified into perfect-match (PM) and mis-match (MM)
probes. While former is a measure of specific binding, the lat-ter is a measure
of non-specific binding. The behavior of the MM probes has especially proven to
be elusive. The present study investigates qualita-tive similarities in the
distributional signatures and local correlation struc-tures/patchiness between
the PM and MM probe intensities. These qualita-tive similarities are
established on publicly available microarrays generated across laboratories
investigating the same paradigm. Persistence of these similarities across raw
as well as background subtracted probe intensities is also investigated. The
results presented raise fundamental concerns in inter-preting Genechip
oligonucleotide microarray data.


title: Cross-correlation Weak Lensing of SDSS Galaxy Clusters I: Measurements

abstract:
  This is the first in a series of papers on the weak lensing effect caused by
clusters of galaxies in Sloan Digital Sky Survey. The photometrically selected
cluster sample, known as MaxBCG, includes ~130,000 objects between redshift 0.1
and 0.3, ranging in size from small groups to massive clusters. We split the
clusters into bins of richness and luminosity and stack the surface density
contrast to produce mean radial profiles. The mean profiles are detected over a
range of scales, from the inner halo (25 kpc/h) well into the surrounding large
scale structure (30 Mpc/h), with a significance of 15 to 20 in each bin. The
signal over this large range of scales is best interpreted in terms of the
cluster-mass cross-correlation function. We pay careful attention to sources of
systematic error, correcting for them where possible. The resulting signals are
calibrated to the ~10% level, with the dominant remaining uncertainty being the
redshift distribution of the background sources. We find that the profiles
scale strongly with richness and luminosity. We find the signal within a given
richness bin depends upon luminosity, suggesting that luminosity is more
closely correlated with mass than galaxy counts. We split the samples by
redshift but detect no significant evolution. The profiles are not well
described by power laws. In a subsequent series of papers we invert the
profiles to three-dimensional mass profiles, show that they are well fit by a
halo model description, measure mass-to-light ratios and provide a cosmological
interpretation.


abstract:
  We study Brauer-Manin obstructions to integral points on open subsets of the
projective plane.


title: iso-spectral Euler-Bernoulli beams \`a la Sophus Lie

abstract:
  We obtain iso-spectral Euler-Bernoulli beams by using factorization and Lie
symmetry techniques. The canonical Euler-Bernoulli beam operator is factorized
as the product of a second-order linear differential operator and its adjoint.
The factors are then reversed to obtain iso-spectral beams. The factorization
is possible provided the coefficients of the factors satisfy a system of
non-linear ordinary differential equations . The uncoupling of this system
yields a single non-linear third-order ordinary differential equation. This
ordinary differential equation, refer to as the {\it principal equation}, is
analyzed and solved using Lie group methods. We show that the principal
equation may admit a one-dimensional or three-dimensional symmetry Lie algebra.
When the principal system admits a unique symmetry, the best we can do is to
depress its order by one. We obtain a one-parameter family of solutions in this
case. The maximally symmetric case is shown to be isomorphic to a Chazy
equation which is solved in closed form to derive the general solution of the
principal equation.


title: Hypervelocity Stars from the Andromeda Galaxy

abstract:
  Hypervelocity stars (HVSs) discovered in the Milky Way (MW) halo are thought
to be ejected from near the massive black hole (MBH) at the galactic centre. In
this paper we investigate the spatial and velocity distributions of the HVSs
which are expected to be similarly produced in the Andromeda galaxy (M31). We
consider three different HVS production mechanisms: (i) the disruption of
stellar binaries by the galactocentric MBH; (ii) the ejection of stars by an
in-spiraling intermediate mass black hole; and (iii) the scattering of stars
off a cluster of stellar-mass black holes orbiting around the MBH. While the
first two mechanisms would produce large numbers of HVSs in M31, we show that
the third mechanism would not be effective in M31. We numerically calculate
1.2*10^6 trajectories of HVSs from M31 within a simple model of the Local Group
and hence infer the current distribution of these stars. Gravitational focusing
of the HVSs by the MW and the diffuse Local Group medium leads to high
densities of low mass (~ solar mass) M31 HVSs near the MW. Within the
virialized MW halo, we expect there to be of order 1000 HVSs for the first
mechanism and a few hundred HVSs for the second mechanism; many of these stars
should have distinctively large approach velocities (< -500 km/s). In addition,
we predict ~5 hypervelocity RGB stars within the M31 halo which could be
identified observationally. Future MW astrometric surveys or searches for
distant giants could thus find HVSs from M31.


title: Impact of slepton generation mixing on the search for sneutrinos

abstract:
  We perform a systematic study of sneutrino production and decays in the
Minimal Supersymmetric Standard Model (MSSM) with slepton generation mixing. We
study both fermionic decays like sneutrino \to l^- chargino^+, nu neutralino
and bosonic decays such as sneutrino \to slepton^- H^+, slepton^- W^+. We show
that the effect of slepton generation mixing on the sneutrino production cross
sections and its decay branching ratios can be quite large in a significant
part of the MSSM parameter space despite the very strong experimental limits on
lepton flavour violating processes. This could have an important impact on the
search for sneutrinos and the determination of the MSSM parameters at future
colliders, such as LHC, ILC, CLIC and muon collider.


title:
Measuring the mean and scatter of the X-ray luminosity -- optical
  richness relation for maxBCG galaxy clusters

abstract:
  Determining the scaling relations between galaxy cluster observables requires
large samples of uniformly observed clusters. We measure the mean X-ray
luminosity--optical richness (L_X--N_200) relation for an approximately
volume-limited sample of more than 17,000 optically-selected clusters from the
maxBCG catalog spanning the redshift range 0.1<z<0.3. By stacking the X-ray
emission from many clusters using ROSAT All-Sky Survey data, we are able to
measure mean X-ray luminosities to ~10% (including systematic errors) for
clusters in nine independent optical richness bins. In addition, we are able to
crudely measure individual X-ray emission from ~800 of the richest clusters.
Assuming a log-normal form for the scatter in the L_X--N_200 relation, we
measure \sigma_\ln{L}=0.86+/-0.03 at fixed N_200. This scatter is large enough
to significantly bias the mean stacked relation. The corrected median relation
can be parameterized by L_X = (e^\alpha)(N_200/40)^\beta 10^42 h^-2 ergs/s,
where \alpha = 3.57+/-0.08 and \beta = 1.82+/-0.05. We find that X-ray selected
clusters are significantly brighter than optically-selected clusters at a given
optical richness. This selection bias explains the apparently X-ray
underluminous nature of optically-selected cluster catalogs.


title:
Cross-correlation Weak Lensing of SDSS galaxy Clusters II: Cluster
  Density Profiles and the Mass--Richness Relation

abstract:
  We interpret and model the statistical weak lensing measurements around
130,000 groups and clusters of galaxies in the Sloan Digital Sky Survey
presented by Sheldon et al. 2007 (Paper I). We present non-parametric
inversions of the 2D shear profiles to the mean 3D cluster density and mass
profiles in bins of both optical richness and cluster i-band luminosity. We
correct the inferred 3D profiles for systematic effects, including non-linear
shear and the fact that cluster halos are not all precisely centered on their
brightest galaxies. We also model the measured cluster shear profile as a sum
of contributions from the brightest central galaxy, the cluster dark matter
halo, and neighboring halos. We infer the relations between mean cluster virial
mass and optical richness and luminosity over two orders of magnitude in
cluster mass; the virial mass at fixed richness or luminosity is determined
with a precision of 13% including both statistical and systematic errors. We
also constrain the halo concentration parameter and halo bias as a function of
cluster mass; both are in good agreement with predictions of LCDM models. The
methods employed here will be applicable to deeper, wide-area optical surveys
that aim to constrain the nature of the dark energy, such as the Dark Energy
Survey, the Large Synoptic Survey Telescope and space-based surveys.


title: The Relativistic Factor in the Orbital Dynamics of Point Masses

abstract:
  There is a growing population of relativistically relevant minor bodies in
the Solar System and a growing population of massive extrasolar planets with
orbits very close to the central star where relativistic effects should have
some signature. Our purpose is to review how general relativity affects the
orbital dynamics of the planetary systems and to define a suitable relativistic
correction for Solar System orbital studies when only point masses are
considered. Using relativistic formulae for the N body problem suited for a
planetary system given in the literature we present a series of numerical
orbital integrations designed to test the relevance of the effects due to the
general theory of relativity in the case of our Solar System. Comparison
between different algorithms for accounting for the relativistic corrections
are performed. Relativistic effects generated by the Sun or by the central star
are the most relevant ones and produce evident modifications in the secular
dynamics of the inner Solar System. The Kozai mechanism, for example, is
modified due to the relativistic effects on the argument of the perihelion.
Relativistic effects generated by planets instead are of very low relevance but
detectable in numerical simulations.


title:
Fabrication and Characterization of Two-Dimensional Photonic Crystal
  Microcavities in Nanocrystalline Diamond

abstract:
  Diamond-based photonic devices offer exceptional opportunity to study cavity
QED at room temperature. Here we report fabrication and optical
characterization of high quality photonic crystal (PC) microcavities based on
nanocrystalline diamond. Fundamental modes near the emission wavelength of
negatively charged nitrogen-vacancy (N-V) centers (637 nm) with quality factors
(Qs) as high as 585 were observed. Three-dimensional Finite-Difference
Time-Domain (FDTD) simulations were carried out and had excellent agreement
with experimental results in the values of the mode frequencies. Polarization
measurements of the modes were characterized; their anomalous behavior provides
important insights to scattering loss in these structures.


title:
Cross-correlation Weak Lensing of SDSS Galaxy Clusters III:
  Mass-to-light Ratios

abstract:
  We present measurements of the excess mass-to-light ratio measured
aroundMaxBCG galaxy clusters observed in the SDSS. This red sequence cluster
sample includes objects from small groups with masses ranging from ~5x10^{12}
to ~10^{15} M_{sun}/h. Using cross-correlation weak lensing, we measure the
excess mass density profile above the universal mean \Delta \rho(r) = \rho(r) -
\bar{\rho} for clusters in bins of richness and optical luminosity. We also
measure the excess luminosity density \Delta l(r) = l(r) - \bar{l} measured in
the z=0.25 i-band. For both mass and light, we de-project the profiles to
produce 3D mass and light profiles over scales from 25 kpc/ to 22 Mpc/h. From
these profiles we calculate the cumulative excess mass M(r) and excess light
L(r) as a function of separation from the BCG. On small scales, where \rho(r)
>> \bar{\rho}, the integrated mass-to-light profile may be interpreted as the
cluster mass-to-light ratio. We find the M/L_{200}, the mass-to-light ratio
within r_{200}, scales with cluster mass as a power law with index 0.33+/-0.02.
On large scales, where \rho(r) ~ \bar{\rho}, the M/L approaches an asymptotic
value independent of cluster richness. For small groups, the mean M/L_{200} is
much smaller than the asymptotic value, while for large clusters it is
consistent with the asymptotic value. This asymptotic value should be
proportional to the mean mass-to-light ratio of the universe <M/L>. We find
<M/L>/b^2_{ml} = 362+/-54 h (statistical). There is additional uncertainty in
the overall calibration at the ~10% level. The parameter b_{ml} is primarily a
function of the bias of the L <~ L_* galaxies used as light tracers, and should
be of order unity. Multiplying by the luminosity density in the same bandpass
we find \Omega_m/b^2_{ml} = 0.02+/-0.03, independent of the Hubble parameter.


title: The electronic properties of graphene

abstract:
  This article reviews the basic theoretical aspects of graphene, a one atom
thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic
excitations. The Dirac electrons can be controlled by application of external
electric and magnetic fields, or by altering sample geometry and/or topology.
We show that the Dirac electrons behave in unusual ways in tunneling,
confinement, and integer quantum Hall effect. We discuss the electronic
properties of graphene stacks and show that they vary with stacking order and
number of layers. Edge (surface) states in graphene are strongly dependent on
the edge termination (zigzag or armchair) and affect the physical properties of
nanoribbons. We also discuss how different types of disorder modify the Dirac
equation leading to unusual spectroscopic and transport properties. The effects
of electron-electron and electron-phonon interactions in single layer and
multilayer graphene are also presented.


title:
The Nature of the Dense Core Population in the Pipe Nebula: Thermal
  Cores Under Pressure

abstract:
  In this paper we present the results of a systematic investigation of an
entire population of starless dust cores within a single molecular cloud.
Analysis of extinction data shows the cores to be dense objects characterized
by a narrow range of density. Analysis of C18O and NH3 molecular-line
observations reveals very narrow lines. The non-thermal velocity dispersions
measured in both these tracers are found to be subsonic for the large majority
of the cores and show no correlation with core mass (or size). Thermal pressure
is thus the dominate source of internal gas pressure and support for most of
the core population. The total internal gas pressures of the cores are found to
be roughly independent of core mass over the entire range of the core mass
function (CMF) indicating that the cores are in pressure equilibrium with an
external source of pressure. This external pressure is most likely provided by
the weight of the surrounding Pipe cloud within which the cores are embedded.
Most of the cores appear to be pressure confined, gravitationally unbound
entities whose nature, structure and future evolution are determined by only a
few physical factors which include self-gravity, the fundamental processes of
thermal physics and the simple requirement of pressure equilibrium with the
surrounding environment. The observed core properties likely constitute the
initial conditions for star formation in dense gas. The entire core population
is found to be characterized by a single critical Bonnor-Ebert mass. This mass
coincides with the characteristic mass of the Pipe CMF indicating that most
cores formed in the cloud are near critical stability. This suggests that the
mass function of cores (and the IMF) has its origin in the physical process of
thermal fragmentation in a pressurized medium.


title: On a class of weighted anisotropic Sobolev inequalities

abstract:
  In this article, motivated by a work of Caffarelli and Cordoba in phase
transitions analysis, we prove new weighted anisotropic Sobolev type
inequalities, that is Sobolev type inequalities where different derivatives
have different weight functions. The inequalities we are dealing with, are also
intimately connected to weighted Sobolev inequalities for Grushin type
operators, the weights being not necessarily Muckenhoupt. For example we
consider here Sobolev inequalities on finite cylinders, the weights being
different powers of the distance function from the top and the bottom of the
cylinder. We also prove similar inequalities in the more general case in which
the weight is the distance function from an higher codimension part of the
boundary.


title: An Optimal Linear Time Algorithm for Quasi-Monotonic Segmentation

abstract:
  Monotonicity is a simple yet significant qualitative characteristic. We
consider the problem of segmenting a sequence in up to K segments. We want
segments to be as monotonic as possible and to alternate signs. We propose a
quality metric for this problem using the l_inf norm, and we present an optimal
linear time algorithm based on novel formalism. Moreover, given a
precomputation in time O(n log n) consisting of a labeling of all extrema, we
compute any optimal segmentation in constant time. We compare experimentally
its performance to two piecewise linear segmentation heuristics (top-down and
bottom-up). We show that our algorithm is faster and more accurate.
Applications include pattern recognition and qualitative modeling.


title: Using RDF to Model the Structure and Process of Systems

abstract:
  Many systems can be described in terms of networks of discrete elements and
their various relationships to one another. A semantic network, or
multi-relational network, is a directed labeled graph consisting of a
heterogeneous set of entities connected by a heterogeneous set of
relationships. Semantic networks serve as a promising general-purpose modeling
substrate for complex systems. Various standardized formats and tools are now
available to support practical, large-scale semantic network models. First, the
Resource Description Framework (RDF) offers a standardized semantic network
data model that can be further formalized by ontology modeling languages such
as RDF Schema (RDFS) and the Web Ontology Language (OWL). Second, the recent
introduction of highly performant triple-stores (i.e. semantic network
databases) allows semantic network models on the order of $10^9$ edges to be
efficiently stored and manipulated. RDF and its related technologies are
currently used extensively in the domains of computer science, digital library
science, and the biological sciences. This article will provide an introduction
to RDF/RDFS/OWL and an examination of its suitability to model discrete element
complex systems.


title: Supersymmetric Giant Graviton Solutions in AdS_3

abstract:
  We parameterize all classical probe brane configurations that preserve 4
supersymmetries in (a) the extremal D1-D5 geometry, (b) the extremal D1-D5-P
geometry, (c) the smooth D1-D5 solutions proposed by Lunin and Mathur and (d)
global $AdS_3 \times S_3 \times T^4/K3$. These configurations consist of D1
branes, D5 branes and bound states of D5 and D1 branes with the property that a
particular Killing vector is tangent to the brane worldvolume at each point. We
show that the supersymmetric sector of the D5 brane worldvolume theory may be
analyzed in an effective 1+1 dimensional framework that places it on the same
footing as D1 branes. In global AdS and the corresponding Lunin-Mathur
solution, the solutions we describe are `bound' to the center of AdS for
generic parameters and cannot escape to infinity. We show that these probes
only exist on the submanifold of moduli space where the background $B_{NS}$
field and theta angle vanish. We quantize these probes in the near horizon
region of the extremal D1-D5 geometry and obtain the theory of long strings
discussed by Seiberg and Witten.


title: The K+K+ Scattering Length from Lattice QCD

abstract:
  The K+K+ scattering length is calculated in fully-dynamical lattice QCD with
domain-wall valence quarks on the MILC asqtad-improved gauge configurations
with rooted staggered sea quarks. Three-flavor mixed-action chiral perturbation
theory at next-to-leading order, which includes the leading effects of the
finite lattice spacing, is used to extrapolate the results of the lattice
calculation to the physical value of m_{K+}/f_{K+}. We find m_{K+} a_{K+K+} =
-0.352 +- 0.016, where the statistical and systematic errors have been combined
in quadrature.


title: Inflation from Wrapped Branes

abstract:
  We show that the use of higher dimensional wrapped branes can significantly
extend the inflaton field range compared to brane inflation models which use
D3-branes. We construct a simple inflationary model in terms of 5-branes
wrapping a 2-cycle and traveling towards the tip of the Klebanov-Strassler
throat. Inflation ends when the branes reach the tip of the cone and
self-annihilate. Assuming a quadratic potential for the brane it is possible to
match the CMB data in the DBI regime, but we argue that the backreaction of the
brane is important and cannot be neglected. This scenario predicts a strong
non-Gaussian signal and possibly detectable gravitational waves.


title: Counting Giant Gravitons in AdS_3

abstract:
  We quantize the set of all quarter BPS brane probe solutions in global AdS_3
\times S^3 \times T^4/K3 found in arxiv:0709.1168 [hep-th]. We show that,
generically, these solutions give rise to states in discrete representations of
the SL(2,R) WZW model on AdS_3. Our procedure provides us with a detailed
description of the low energy 1/4 and 1/2 BPS sectors of string theory on this
background. The 1/4 BPS partition function jumps as we move off the point in
moduli space where the bulk theta angle and NS-NS fields vanish. We show that
generic 1/2 BPS states are protected because they correspond to geodesics
rather than puffed up branes. By exactly quantizing the simplest of the probes
above, we verify our description of 1/4 BPS states and find agreement with the
known spectrum of 1/2 BPS states of the boundary theory. We also consider the
contribution of these probes to the elliptic genus and discuss puzzles, and
their possible resolutions, in reproducing the elliptic genus of the symmetric
product.


title:
Galaxy Evolution and Star Formation Efficiency in the Last Half of the
  Universe

abstract:
  We present the results of a CO(1-0) emission survey with the IRAM 30m of 30
galaxies at moderate redshift (z ~ 0.2-0.6) to explore galaxy evolution and in
particular the star formation efficiency, in the redshift range filling the gap
between local and very high-z objects. Our detection rate is about 50%. One of
the bright objects was mapped at high resolution with the IRAM interferometer,
and about 50% of the total emission found in the 27 arcsec (97 kpc) single dish
beam is recovered by the interferometer, suggesting the presence of extended
emission. The FIR-to-CO luminosity ratio is enhanced, following the increasing
trend observed between local and high-z ultra-luminous starbursts.


title: When--and how--can a cellular automaton be rewritten as a lattice gas?

abstract:
  Both cellular automata (CA) and lattice-gas automata (LG) provide finite
algorithmic presentations for certain classes of infinite dynamical systems
studied by symbolic dynamics; it is customary to use the term `cellular
automaton' or `lattice gas' for the dynamic system itself as well as for its
presentation. The two kinds of presentation share many traits but also display
profound differences on issues ranging from decidability to modeling
convenience and physical implementability.
  Following a conjecture by Toffoli and Margolus, it had been proved by Kari
(and by Durand--Lose for more than two dimensions) that any invertible CA can
be rewritten as an LG (with a possibly much more complex ``unit cell''). But
until now it was not known whether this is possible in general for
noninvertible CA--which comprise ``almost all'' CA and represent the bulk of
examples in theory and applications. Even circumstantial evidence--whether in
favor or against--was lacking.
  Here, for noninvertible CA, (a) we prove that an LG presentation is out of
the question for the vanishingly small class of surjective ones. We then turn
our attention to all the rest--noninvertible and nonsurjective--which comprise
all the typical ones, including Conway's `Game of Life'. For these (b) we prove
by explicit construction that all the one-dimensional ones are representable as
LG, and (c) we present and motivate the conjecture that this result extends to
any number of dimensions.
  The tradeoff between dissipation rate and structural complexity implied by
the above results have compelling implications for the thermodynamics of
computation at a microscopic scale.


title:
Electrochemically Top Gated Graphene: Monitoring Dopants by Raman
  Scattering

abstract:
  We demonstrate electrochemical top gating of graphene by using a solid
polymer electrolyte. This allows to reach much higher electron and hole doping
than standard back gating. In-situ Raman measurements monitor the doping. The G
peak stiffens and sharpens for both electron and hole doping, while the 2D peak
shows a different response to holes and electrons. Its position increases for
hole doping, while it softens for high electron doping. The variation of G peak
position is a signature of the non-adiabatic Kohn anomaly at $\Gamma$. On the
other hand, for visible excitation, the variation of the 2D peak position is
ruled by charge transfer. The intensity ratio of G and 2D peaks shows a strong
dependence on doping, making it a sensitive parameter to monitor charges.


title: Multiple fluxoid transitions in mesoscopic superconducting rings

abstract:
  The authors report magnetic measurements of fluxoid transitions in
mesoscopic, superconducting aluminum rings. The transitions are induced by
applying a flux to the ring so that the induced supercurrent approaches the
critical current. In a temperature range near $T_c$, only a single fluxoid
enters or leaves at a time, leading to a final state above the ground state.
Upon lowering the temperature, several fluxoids enter or leave at once, and the
final state approaches the ground state, which can be reached below
approximately 0.5 $T_c$. A model based on the widely used time dependent
Ginzburg-Landau theory for gapless superconductors can only explain the data if
unphysical parameters are used. Heating and quasiparticle diffusion may be
important for a quantitative understanding of this experiment, which could
provide a model system for studying the nonlinear dynamics of superconductors
far from equilibrium.


title: On equitable zero sums

abstract:
  It is well-known that any sequence of at least N integers contains a
subsequence whose sum is 0 (mod N). However, there can be very few subsequences
with this property (e.g. if the initial sequence is just N 1's, then there is
only one subsequence). When the length L of the sequence is much longer, we
might expect that there are 2^L/N subsequences with this property (imagine the
subsequences have sum-of-terms uniformly distributed modulo N -- the 0 class
gets about 2^L/N subsequences); however, it is easy to see that this is
actually false. Nonetheless, we are able to prove that if the initial sequence
has length at least 4N, and N is odd, then there is a subsequence of length L >
N, having at least 2^L/N subsequences that sum to 0 mod N.


title:
Magnetowave Induced Plasma Wakefield Acceleration for Ultra High Energy
  Cosmic Rays

abstract:
  Magnetowave induced plasma wakefield acceleration (MPWA) in a relativistic
astrophysical outflow has been proposed as a viable mechanism for the
acceleration of cosmic particles to ultra high energies. Here we present
simulation results that clearly demonstrate the viability of this mechanism for
the first time. We invoke the high frequency and high speed whistler mode for
the driving pulse. The plasma wakefield so induced validates precisely the
theoretical prediction. We show that under appropriate conditions, the plasma
wakefield maintains very high coherence and can sustain high-gradient
acceleration over a macroscopic distance. Invoking gamma ray burst (GRB) as the
source, we show that MPWA production of ultra high energy cosmic rays (UHECR)
beyond ZeV 10^21 eV is possible.


title:
The Trigonometric Parallax of the Brown Dwarf Planetary System 2MASSW
  J1207334-393254

abstract:
  We have measured a trigonometric parallax to the young brown dwarf 2MASSW
J1207334-393254. The distance [54.0 (+3.2,-2.8) pc] and space motion confirm
membership in the TW Hydrae Association. The primary is a ~25 M_jup brown
dwarf. We discuss the "planetary mass" secondary, which is certainly below the
deuterium-burning limit but whose colors and absolute magnitudes pose
challenges to our current understanding of planetary-mass objects.


title: Inelastic X-ray Scattering Study of Phonons in Superconducting CaC6

abstract:
  We investigate the dispersion and temperature dependence of a number of
phonons in the recently discovered superconductor CaC6 utilizing inelastic
x-ray scattering. Four [00L] and two ab-plane phonon modes are observed, and
measured at temperatures both above and below T_c. In general, our measurements
of phonon dispersions are in good agreement with existing theoretical
calculations of the phonon dispersion. This is significant in light of several
discrepancies between experimental measurements of phonon-derived quantities
and theoretical calculations. The present work suggests that the origin of
these discrepancies lies in the understanding of the electron-phonon coupling
in this material, rather than in the phonons themselves.


title: Variable stars in the Open Cluster M11 (NGC 6705)

abstract:
  V-band time-series CCD photometric observations of the intermediate-age open
cluster M11 were performed to search for variable stars. Using these
time-series data, we carefully examined light variations of all stars in the
observing field. A total of 82 variable stars were discovered, of which 39
stars had been detected recently by Hargis et al. (2005). On the basis of
observational properties such as variable period, light curve shape, and
position on a color-magnitude diagram, we classified their variable types as 11
delta Scuti-type pulsating stars, 2 gamma Doradus-type pulsating stars, 40 W
UMa-type contact eclipsing binaries, 13 Algol-type detached eclipsing binaries,
and 16 eclipsing binaries with long period. Cluster membership for each
variable star was deduced from the previous proper motion results (McNamara et
al. 1977) and position on the color-magnitude diagram. Many pulsating stars and
eclipsing binaries in the region of M11 are probable members of the cluster.


title: Isotopy for extended affine Lie algebras and Lie tori

abstract:
  Centreless Lie tori have been used by E. Neher to construct all extended
affine Lie algebras (EALAs). In this article, we study notions of isotopes and
isotopy for centreless Lie tori, and we use these notions, along with Neher's
construction, to show that there is a 1-1 correspondence between centreless Lie
tori up to isotopy and families of EALAs up to isomorphism. Also, centreless
Lie tori can be coordinatized by unital algebras that are in general
nonassociative, and, for many types of centreless Lie tori, there are classical
notions of isotopes and isotopy for the coordinate algebras. We show for those
types that an isotope of the Lie torus is coordinatized by an isotope of its
coordinate algebra. In writing the article, we have not assumed prior knowledge
of the theories of EALAs, Lie tori or isotopy. In fact, we hope that this
article will help to introduce the reader to these theories and their
interconnections.


title:
Near-Infrared Variability in the 2MASS Calibration Fields: A Search for
  Planetary Transit Candidates

abstract:
  The 2MASS photometric calibration observations cover ~6 square degrees on the
sky in 35 "calibration fields" each sampled in nominal photometric conditions
between 562 and 3692 times during the four years of the 2MASS mission. We
compile a catalog of variables from the calibration observations to search for
M dwarfs transited by extra-solar planets. We present our methods for measuring
periodic and non-periodic flux variability. From 7554 sources with apparent Ks
magnitudes between 5.6 and 16.1, we identify 247 variables, including
extragalactic variables and 23 periodic variables. We have discovered three M
dwarf eclipsing systems, including two candidates for transiting extrasolar
planets.


title:
The Scientific Manuscripts left Unpublished by Ettore Majorana (with
  outlines of his life and work)

abstract:
  We present a panoramic view of the main scientific manuscripts left
unpublished by the brightest Italian theoretical physicist of the XX century,
Ettore Majorana. We deal in particular: (i) with his very original "study"
notes (the so-called "Volumetti"), already published by us in English, in 2003,
c/o Kluwer Acad.Press, Dordrecht & Boston, and in the original Italian
language, in 2006, c/o Zanichelli pub., Bologna, Italy; and (ii) with a
selection of his research notes (the so-called "Quaderni"), that we shall
publish c/o Springer, Berlin. We seize the present opportunity for setting
forth also some suitable -scarcely known- information about Majorana's life and
work, on the basis of documents (letters, testimonies, different documents...)
discovered or collected by ourselves during the last decades. [A finished,
enlarged version of this paper will appear as the editors' Preface, at the
beginning of the coming book "Ettore Majorana - Unpublished Research Notes on
Theoretical Physics", edited by S.Esposito, E.Recami, A.van der Merwe and
R.Battiston, to be printed by Springer verlag, Berlin].


title:
A refinement of Sharkovskii's theorem on orbit types characterized by
  two parameters

abstract:
  The so-called type problem or forcing problem is considered as a way to
generalize Sharkovskii's theorem. In this paper, by focusing on certain types
of orbits, we obtain a solution of the type problem, which gives a refinement
of Sharkovskii's theorem on orbit types characterized by two parameters.


title: Orbit equivalence of one-sided subshifts and the associated C^*-algebras

abstract:
  A $\lambda$-graph system ${\frak L}$ is a generalization of a finite labeled
graph and presents a subshift. We will prove that the topological dynamical
systems $(X_{{\frak L}_1},\sigma_{{\frak L}_1})$ and $(X_{{\frak
L}_2},\sigma_{{\frak L}_2})$ for $\lambda$-graph systems ${\frak L}_1$ and
${\frak L}_2$ are continuously orbit equivalent if and only if there exists an
isomorphism between the associated $C^*$-algebras ${\Cal O}_{{\frak L}_1}$ and
${\Cal O}_{{\frak L}_2}$ keeping their commutative $C^*$-subalgebras
$C(X_{{\frak L}_1})$ and $C(X_{{\frak L}_2})$. It is also equivalent to the
condition that there exists a homeomorphism from $X_{{\frak L}_1}$ to
$X_{{\frak L}_2}$ intertwining their topological full inverse semigroups. In
particular, one-sided subshifts $X_{\Lambda_1}$ and $X_{\Lambda_2}$ are
$\lambda$-continuously orbit equivalent if and only if there exists an
isomorphism between the associated $C^*$-algebras ${\Cal O}_{\Lambda_1}$ and
${\Cal O}_{\Lambda_2}$ keeping their commutative $C^*$-subalgebras
$C(X_{\Lambda_1})$ and $C(X_{\Lambda_2})$.


title:
Entropy of the Schwarzschild-de Sitter Black Hole due to arbitrary spin
  fields in different Coordinates

abstract:
  By using the Newman-Penrose formalism and the improved thin-layer ``brick
wall'' approach, the statistical-mechanical entropies of the Schwarzschild-de
Sitter black hole arising from quantum massless arbitrary spin fields are
studied in the Painlev\'e and Lemaitre coordinates. Although the metrics in
both the Painlev\'e and the Lemaitre coordinates do not obviously possess the
singularities as that in the Schwarzschild-like coordinate, we find that, for
arbitrary spin fields, the entropies in the Painlev\'e and Lemaitre coordinates
are exactly equivalent to that in the Schwarzschild-like coordinate.


title: A spin-dependent local moment approach to the Anderson impurity model

abstract:
  We present an extension of the local moment approach to the Anderson impurity
model with spin-dependent hybridization. By employing the two-self-energy
description, as originally proposed by Logan and co-workers, we applied the
symmetry restoration condition for the case with spin-dependent hybridization.
Self-consistent ground states were determined through variational minimization
of the ground state energy. The results obtained with our spin-dependent local
moment approach applied to a quantum dot system coupled to ferromagnetic leads
are in good agreement with those obtained from previous work using numerical
renormalization group calculations.


title:
Particle Velocity Fluctuations in Steady State Sedimentation:
  Stratification Controlled Correlations

abstract:
  The structure and dynamics of steady state sedimentation of semi-concentrated
($\phi=0.10$) monodisperse spheres are studied in liquid fluidized beds. Laser
turbidity and particle imaging methods are used to measure the particle
velocity fluctuations and the steady state concentration profiles. Using a wide
range of particle and system sizes, we find that the measured gradients $\nabla
\phi$, the fluctuation magnitudes $\sigma_v$, and their spatial correlation
lengths $\xi$, are not uniform in the columns - they all show strongly
$z-$dependent profiles. These profiles also display a scaling in which results
from different particle sizes collapse together when plotted in the forms
$-a\nabla \phi(z)$, $\xi(z)/a$, and $\sigma_v(z)/v_p$, demonstrating the
universality of the particle dynamics and structure in steady state
sedimentation. Our results are also used to test a recently proposed model for
the correlation lengths $\xi(z)$ in terms of the concentration stratification
$\nabla \phi(z)$ [P.J. Mucha and M.P. Brenner, Phys. Fluids {\bf 15}, 1305
(2003)], $\xi(z)=c_0 a[\phi S(\phi)]^{1/5}[-a\nabla\phi(z)]^{-2/5}$. We find
that the correlation lengths predicted by this model are in very good agreement
with our measured values, showing that the origin of the fluctuation length
$\xi$ lies with the concentration stratification $\nabla \phi$.


title: Effect of THz-radiation on Behavior of Male Mice

abstract:
  Effect of terahertz radiation (3.6 THz, 81.5 mkm,15 mV) on some behavioral
patterns of intact mice has been investigated. In home cage mice demonstrated
avoidance of laser ray and enhanced replacement activity in free behavior.
Animals irradiated during 30 minutes manifested an increased level of anxiety,
which was evaluated in the plus maze test on the day following the radiation.


title:
Belief-Propagation for Weighted b-Matchings on Arbitrary Graphs and its
  Relation to Linear Programs with Integer Solutions

abstract:
  We consider the general problem of finding the minimum weight $\bm$-matching
on arbitrary graphs. We prove that, whenever the linear programming (LP)
relaxation of the problem has no fractional solutions, then the belief
propagation (BP) algorithm converges to the correct solution. We also show that
when the LP relaxation has a fractional solution then the BP algorithm can be
used to solve the LP relaxation. Our proof is based on the notion of graph
covers and extends the analysis of (Bayati-Shah-Sharma 2005 and Huang-Jebara
2007}.
  These results are notable in the following regards: (1) It is one of a very
small number of proofs showing correctness of BP without any constraint on the
graph structure. (2) Variants of the proof work for both synchronous and
asynchronous BP; it is the first proof of convergence and correctness of an
asynchronous BP algorithm for a combinatorial optimization problem.


title: Thom polynomials of invariant cones, Schur functions, and positivity

abstract:
  We generalize the notion of Thom polynomials from singularities of maps
between two complex manifolds to invariant cones in representations, and
collections of vector bundles. We prove that the generalized Thom polynomials,
expanded in the products of Schur functions of the bundles, have nonnegative
coefficients. For classical Thom polynomials associated with maps of complex
manifolds, this gives an extension of our former result for stable
singularities to nonnecessary stable ones. We also discuss some related aspects
of Thom polynomials, which makes the article expository to some extent.


title: K-H_2 Quasi-molecular absorption detected in the T-dwarf epsilon Indi Ba

abstract:
  T-type dwarfs present a broad and shallow absorption feature centred around
6950 A in the blue wing of the K doublet at 0.77 micron which resembles in
depth and shape the satellite absorption predicted by detailed collisional
broadening profiles. In our previous work, the predicted line satellite
position was however somewhat too blue compared to the observed feature. In
this paper we investigate whether new calculations of the energy surfaces of
the potentials in the K-H_2 system, including spin-orbit coupling, result in a
closer coincidence of the satellite with the observed position. We also
investigate the extent to which CaH absorption bands contribute to the feature.
We present model atmospheres and synthetic spectra, including gravitational
settling for an improved description of depth-dependent abundances of
refractory elements, and based on new K-H_2 line profiles using improved
interaction potentials. By comparison with a high signal-to-noise optical
spectrum of the T1 dwarf epsilon Indi Ba, we find that these new models do
reproduce the observed feature, while CaH does not contribute for the
atmospheric parameters considered. We also find that CaH is settled out so deep
into the atmosphere that even turbulent vertical mixing would appear
insufficient to bring significant amounts of CaH to the photosphere in dwarfs
later than ~L5. We conclude that previous identification of the feature at this
location in T and late L dwarf spectra with CaH was erroneous, as expected on
physical grounds: calcium condenses onto grains in early L dwarfs and thus
should have settled out of the photosphere in cooler brown dwarfs. This finding
revokes one observational verification for the cloud-clearing theory: a gradual
clearing of the cloud cover in early T dwarfs.


title: Hard exclusive processes with photons

abstract:
  Virtual photons have proven to be very efficient probes of the hadronic
structure, mostly through deep inelastic scattering and related processes. The
advent of high luminosity lepton beams has allowed to enlarge the studied
processes to hard exclusive reactions, such as deeply virtual Compton
scattering and the electroproduction of mesons. We discuss theoretical progress
which has lately been quite remarkable in this domain and first much
encouraging experimental data.


title: Nonlinear diffusion from Einstein's master equation

abstract:
  We generalize Einstein's master equation for random walk processes by
considering that the probability for a particle at position $r$ to make a jump
of length $j$ lattice sites, $P_j(r)$ is a functional of the particle
distribution function $f(r,t)$. By multiscale expansion, we obtain a
generalized advection-diffusion equation. We show that the power law $P_j(r)
\propto f(r)^{\alpha - 1}$ (with $\alpha > 1$) follows from the requirement
that the generalized equation admits of scaling solutions ($ f(r;t) =
t^{-\gamma}\phi (r/t^{\gamma}) $). The solutions have a $q$-exponential form
and are found to be in agreement with the results of Monte-Carlo simulations,
so providing a microscopic basis validating the nonlinear diffusion equation.
Although its hydrodynamic limit is equivalent to the phenomenological porous
media equation, there are extra terms which, in general, cannot be neglected as
evidenced by the Monte-Carlo computations.}


title: Selective advantage for sexual reproduction with random haploid fusion

abstract:
  This paper develops a simplified set of models describing asexual and sexual
replication in unicel- lular diploid organisms. The models assume organisms
whose genomes consist of two chromosomes, where each chromosome is assumed to
be functional if it is equal to some master sequence $ \sigma_0 $, and
non-functional otherwise. The first-order growth rate constant, or fitness, of
an organism, is determined by whether it has zero, one, or two functional
chromosomes in its genome. For a population replicating asexually, a given cell
replicates both of its chromosomes, and splits its genetic material evenly
between the two cells. For a population replicating sexually, a given cell
first divides into two haploids, which enter a haploid pool, fuse into
diploids, and then divide via the normal mitotic process. Haploid fusion is
modeled as a second-order rate process. When the cost for sex is small, as
measured by the ratio of the characteristic haploid fusion time to the
characteristic growth time, we find that sexual replication with random haploid
fusion leads to a greater mean fitness for the population than a purely asexual
strategy. However, independently of the cost for sex, we find that sexual
replication with a selective mating strategy leads to a higher mean fitness
than the random mating strategy. This result is based on the assumption that a
selective mating strategy does not have any additional time or energy costs
over the random mating strategy, an assumption that is discussed in the paper.
The results of this paper are consistent with previous studies suggesting that
sex is favored at intermediate mutation rates, for slowly replicating
organisms, and at high population densities.


title:
Combination of inverse spectral transform method and method of
  characteristics: deformed Pohlmeyer equation

abstract:
  We apply a version of the dressing method to a system of four dimensional
nonlinear Partial Differential Equations (PDEs), which contains both Pohlmeyer
equation (i.e. nonlinear PDE integrable by the Inverse Spectral Transform
Method) and nonlinear matrix PDE integrable by the method of characteristics as
particular reductions. Some other reductions are suggested.


title:
An efficient algorithm finds noticeable trends and examples concerning
  the \v{C}erny conjecture

abstract:
  A word w is called synchronizing (recurrent, reset, directed) word of a
deterministic finite automaton (DFA) if w sends all states of the automaton on
a unique state. Jan Cerny had found in 1964 a sequence of n-state complete DFA
with shortest synchronizing word of length (n-1)^2. He had conjectured that it
is an upper bound for the length of the shortest synchronizing word for any
$n$-state complete DFA.
  The examples of DFA with shortest synchronizing word of length (n-1)^2 are
relatively rare. To the Cerny sequence were added in all examples of Cerny,
Piricka and Rosenauerova (1971), of Kari (2001) and of Roman (2004).
  By help of a program based on some effective algorithms, a wide class of
automata of size less than 11 was checked. The order of the algorithm finding
synchronizing word is quadratic for overwhelming majority of known to date
automata. Some new examples of n-state DFA with minimal synchronizing word of
length (n-1)^2 were discovered. The program recognized some remarkable trends
concerning the length of the minimal synchronizing word.
http://www.cs.biu.ac.il/~trakht/Testas.html


title:
Complex Projection of Quasianti-Hermitian Quaternionic Hamiltonian
  Dynamics

abstract:
  We characterize the subclass of quasianti-Hermitian quaternionic Hamiltonian
dynamics such that their complex projections are one-parameter semigroup
dynamics in the space of complex quasi-Hermitian density matrices. As an
example, the complex projection of a spin-1/2 system in a constant
quasianti-Hermitian quaternionic potential is considered.


title:
Generalized Misner-Sharp quasi-local mass in Einstein-Gauss-Bonnet
  gravity

abstract:
  We investigate properties of a quasi-local mass in a higher-dimensional
spacetime having symmetries corresponding to the isomertries of an
$(n-2)$-dimensional maximally symmetric space in Einstein-Gauss-Bonnet gravity
in the presence of a cosmological constant. We assume that the Gauss-Bonnet
coupling constant is non-negative. The quasi-local mass was recently defined by
one of the authors as a counterpart of the Misner-Sharp quasi-local mass in
general relativity. The quasi-local mass is found to be a quasi-local conserved
charge associated with a locally conserved current constructed from the
generalized Kodama vector and exhibits the unified first law corresponding to
the energy-balance law. In the asymptotically flat case, it converges to the
Arnowitt-Deser-Misner mass at spacelike infinity, while it does to the
Deser-Tekin and Padilla mass at infinity in the case of asymptotically AdS.
Under the dominant energy condition, we show the monotonicity of the
quasi-local mass for any $k$, while the positivity on an untrapped hypersurface
with a regular center is shown for $k=1$ and for $k=0$ with an additional
condition, where $k=\pm1,0$ is the constant sectional curvature of each spatial
section of equipotential surfaces. Under a special relation between coupling
constants, positivity of the quasi-local mass is shown for any $k$ without
assumptions above. We also classify all the vacuum solutions by utilizing the
generalized Kodama vector. Lastly, several conjectures on further
generalization of the quasi-local mass in Lovelock gravity are proposed.


title:
Role of the cooling rate in the stability of the superconducting phase
  of (TMTSF)_2ClO_4

abstract:
  The noncentrosymmetric ClO$_4$ anions of the organic superconductor
(TMTSF)$_2$ClO$_4$ order below 24K. The size of domains where the anions are
ordered is substantially dependent on the cooling rate which is a key parameter
for the stability of the low temperature electronic ground states. We study the
effect of the cooling rate on the SC phase within a self consistent approach in
the framework of the time dependent Ginzburg-Landau theory taking into account
the superconducting fluctuations. We derive the superconducting transition
temperature which is found to decrease with increasing cooling rate in
agreement with recent experimental data.


title: On the Proof Complexity of Deep Inference

abstract:
  We obtain two results about the proof complexity of deep inference: 1)
deep-inference proof systems are as powerful as Frege ones, even when both are
extended with the Tseitin extension rule or with the substitution rule; 2)
there are analytic deep-inference proof systems that exhibit an exponential
speed-up over analytic Gentzen proof systems that they polynomially simulate.


title: Towards Z_2-protected gauge--Higgs unification

abstract:
  In theories with flux compactification in eight or higher dimensions, the
extra-dimensional components of the gauge field may be regarded as the Higgs
field candidates. We suggest a way to protect these components from getting
large tree-level masses by imposing a $Z_2$-symmetry acting on compact
manifolds and background fields on them. In our scheme the infinite series of
heavy KK modes naturally decouples from the light Higgs candidates, whose
number is generically larger than one. We also present toy models with three
families of leptons, illustrating that the Yukawa sector in our scheme is
fairly strongly constrained. In one of these models, one fermion gets a
tree-level mass after electroweak symmetry breaking, while two others remain
naturally massless at the tree level.


title: Searches for New Physics by the H1 Experiment at HERA

abstract:
  The high energy program of the HERA $ep$ collider ended in March 2007, where
data equivalent to an integrated luminosity of $\sim$ 0.5 fb$^{-1}$ has been
collected by the H1 experiment. In this context, some of the most recent
results from H1 about searches for new phenomena are presented.


title: Harmonic ultrafilters

abstract:
  A set of natural numbers will be called \emph{harmonic} if the reciprocals of
its elements form a divergent series. An ultrafilter of the natural numbers
will he called \emph{harmonic} if all each members are harmonic sets. The
harmonic ultrafilters are shown to constitute a compact semigroup under the
Glazer addition and its smallest ideal is obtained.
  This paper is an extension of work begun by Hindman. Alle ingredients are
found in the treatise by Hindman and Strauss.


title: Normalisation Control in Deep Inference via Atomic Flows

abstract:
  We introduce `atomic flows': they are graphs obtained from derivations by
tracing atom occurrences and forgetting the logical structure. We study simple
manipulations of atomic flows that correspond to complex reductions on
derivations. This allows us to prove, for propositional logic, a new and very
general normalisation theorem, which contains cut elimination as a special
case. We operate in deep inference, which is more general than other syntactic
paradigms, and where normalisation is more difficult to control. We argue that
atomic flows are a significant technical advance for normalisation theory,
because 1) the technique they support is largely independent of syntax; 2)
indeed, it is largely independent of logical inference rules; 3) they
constitute a powerful geometric formalism, which is more intuitive than syntax.


title:
Superconductivity and Spin gap in the zigzag chain t-J model simulating
  a CuO double chain in Pr_2Ba_4Cu_7O_15-delta

abstract:
  Using the numerical diagonalization method, we examine the one-dimensional
t_1-t_2-J_1-J_2 model (zigzag chain t-J model) which represents an effective
model for metallic CuO double chain in the superconductor
Pr_2Ba_4Cu_7O_15-\delta. Based on the Tomonaga-Luttinger liquid theory, we
calculate the Luttinger-liquid parameter K_\rho as a function of electron
density n. It is found that superconductivity is realized in parameter region
corresponding to the experimental result. We show phase diagram of spin gap on
the t_2/|t_1|-n plane by analyzing the expectation value of twist-operator
Z_\sigma in the spin sector. The spin gap appears in the region with large
t_2/|t_1|, where the phase boundary at half-filling is consistent with that of
the known frustrated quantum spin system. The analysis also suggests that the
estimated value of the spin gap reaches 100K in the realistic parameter region
of Pr_2Ba_4Cu_7O_15-delta.


title: The P versus NP Brief

abstract:
  This paper discusses why P and NP are likely to be different. It analyses the
essence of the concepts and points out that P and NP might be diverse by sheer
definition. It also speculates that P and NP may be unequal due to natural
laws.


title: The measurement errors in the Swift-UVOT and XMM-OM

abstract:
  The probability of photon measurement in some photon counting
instrumentation, such as the Optical Monitor on the XMM-Newton satellite, and
the UVOT on the Swift satellite, does not follow a Poisson distribution due to
the detector characteristics, but a Binomial distribution. For a single-pixel
approximation, an expression was derived for the incident countrate as a
function of the measured count rate by Fordham, Moorhead and Galbraith (2000).
We show that the measured countrate error is binomial, and extend their
formalism to derive the error in the incident count rate. The error on the
incident count rate at large count rates is larger than the Poisson-error of
the incident count rate.


title: Primitive Characters and Permutation Characters of Solvable Groups

abstract:
  Let X be an irreducible, primitive complex character of the finite solvable
group G, and let X* denote the complex conjugate character. If the degree X(1)
is odd, then we show how to associate to X in a unique way, a conjugacy class
of subgroups U of G for which X*X = (1_U)^G, the permutation character on the
cosets of U. We investigate this situation and give a number of applications to
properties of primitive characters of solvable and p-solvable groups.


title: Hermitian conjugate measurement

abstract:
  We propose a new class of probabilistic reversing operations on the state of
a system that was disturbed by a weak measurement. It can approximately recover
the original state from the disturbed state especially with an additional
information gain using the Hermitian conjugate of the measurement operator. We
illustrate the general scheme by considering a quantum measurement consisting
of spin systems with an experimentally feasible interaction and show that the
reversing operation simultaneously increases both the fidelity to the original
state and the information gain with such a high probability of success that
their average values increase simultaneously.


title: Likelihood ratios and Bayesian inference for Poisson channels

abstract:
  In recent years, infinite-dimensional methods have been introduced for the
Gaussian channels estimation. The aim of this paper is to study the application
of similar methods to Poisson channels. In particular we compute the Bayesian
estimator of a Poisson channel using the likelihood ratio and the discrete
Malliavin gradient. This algorithm is suitable for numerical implementation via
the Monte-Carlo scheme. As an application we provide an new proof of the
formula obtained recently by Guo, Shamai and Verdu\'u relating some derivatives
of the input-output mutual information of a time-continuous Poisson channel and
the conditional mean estimator of the input. These results are then extended to
mixed Gaussian-Poisson channels.


title: Distinctive features in the quantum sub-dynamics of bipartite systems

abstract:
  Distinctive features in the sub-dynamics of an interacting bipartite system
are explored. The sub-dynamic Heisenberg operators are introduced in a novel
way leading to the quasi-particle-like concept in the respective subsystems.
This formulation is illustrated using the known exact solutions of the generic
(Jaynes - Cummings) model of interacting bipartite system of a spin 1/2
particle and a single mode electromagnetic field (more generally, boson field).
The striking effects of interaction and entanglement are reflected in the
dressing of the non-interacting number and spin representations, displaying
quasi-particle-like properties. This development may be at the heart of the
physics of back - action discussed in the recent literature.


title:
Locating the zeros of partial sums of exp(z) with Riemann-Hilbert
  methods

abstract:
  In this paper we derive uniform asymptotic expansions for the partial sums of
the exponential series. We indicate how this information will be used in a
later publication to obtain full and explicitly computable asymptotic
expansions with error bounds for all zeros of the Taylor polynomials
$p_{n-1}(z) = \sum_{k=0}^{n-1} z^k/ k!$. Our proof is based on a representation
of $p_{n-1}(nz)$ in terms of an integral of the form $\int_{\gamma}
\frac{e^{n\phi(s)}}{s-z}ds$. We demonstrate how to derive uniform expansions
for such integrals using a Riemann-Hilbert approach. A comparison with
classical steepest descent analysis shows the advantages of the Riemann-Hilbert
analysis in particular for points $z$ that are close to the critical points of
$\phi$.


title:
Statistical mechanical theory of an oscillating isolated system. The
  relaxation to equilibrium

abstract:
  In this contribution we show that a suitably defined nonequilibrium entropy
of an N-body isolated system is not a constant of the motion in general and its
variation is bounded, the bounds determined by the thermodynamic entropy, i.e.,
the equilibrium entropy. We define the nonequilibrium entropy as a convex
functional of the set of n-particle reduced distribution functions
(n=0,......., N) generalizing the Gibbs fine-grained entropy formula.
Additionally, as a consequence of our microscopic analysis we find that this
nonequilibrium entropy behaves as a free entropic oscillator. In the approach
to the equilibrium regime we find relaxation equations of the Fokker-Planck
type, particularly for the one-particle distribution function.


title: Haar expectations of ratios of random characteristic polynomials

abstract:
  We compute Haar ensemble averages of ratios of random characteristic
polynomials for the classical Lie groups K = O(N), SO(N), and USp(N). To that
end, we start from the Clifford-Weyl algebera in its canonical realization on
the complex of holomorphic differential forms for a C-vector space V. From it
we construct the Fock representation of an orthosymplectic Lie superalgebra osp
associated to V. Particular attention is paid to defining Howe's oscillator
semigroup and the representation that partially exponentiates the Lie algebra
representation of sp in osp. In the process, by pushing the semigroup
representation to its boundary and arguing by continuity, we provide a
construction of the Shale-Weil-Segal representation of the metaplectic group.
  To deal with a product of n ratios of characteristic polynomials, we let V =
C^n \otimes C^N where C^N is equipped with its standard K-representation, and
focus on the subspace of K-equivariant forms. By Howe duality, this is a
highest-weight irreducible representation of the centralizer g of Lie(K) in
osp. We identify the K-Haar expectation of n ratios with the character of this
g-representation, which we show to be uniquely determined by analyticity, Weyl
group invariance, certain weight constraints and a system of differential
equations coming from the Laplace-Casimir invariants of g. We find an explicit
solution to the problem posed by all these conditions. In this way we prove
that the said Haar expectations are expressed by a Weyl-type character formula
for all integers N \ge 1. This completes earlier work by Conrey, Farmer, and
Zirnbauer for the case of U(N).


title: The Persian-Toledan Astronomical Connection and the European Renaissance

abstract:
  This paper aims at presenting a brief overview of astronomical exchanges
between the Eastern and Western parts of the Islamic world from the 8th to 14th
century. These cultural interactions were in fact vaster involving Persian,
Indian, Greek, and Chinese traditions. I will particularly focus on some
interesting relations between the Persian astronomical heritage and the
Andalusian (Spanish) achievements in that period. After a brief introduction
dealing mainly with a couple of terminological remarks, I will present a
glimpse of the historical context in which Muslim science developed. In Section
3, the origins of Muslim astronomy will be briefly examined. Section 4 will be
concerned with Khwarizmi, the Persian astronomer/mathematician who wrote the
first major astronomical work in the Muslim world. His influence on later
Andalusian astronomy will be looked into in Section 5. Andalusian astronomy
flourished in the 11th century, as will be studied in Section 6. Among its
major achievements were the Toledan Tables and the Alfonsine Tables, which will
be presented in Section 7. The Tables had a major position in European
astronomy until the advent of Copernicus in the 16th century. Since Ptolemy's
models were not satisfactory, Muslim astronomers tried to improve them, as we
will see in Section 8. This Section also shows how Andalusian astronomers took
part in this effort, which was necessary in the path to the Scientific
Revolution. Finally, Section 9 presents the Spanish influence on the eve of the
Renaissance.


title:
High-field vortices in Josephson junctions with alternating critical
  current density

abstract:
  We study long Josephson junctions with the critical current density
alternating along the junction. New equilibrium states, which we call the field
synchronized or FS states, are shown to exist if the applied field is from
narrow intervals centered around equidistant series of resonant fields, $H_m$.
The values of $H_m$ are much higher than the flux penetration field, $H_s$. The
flux per period of the alternating critical current density, $\phi_i$, is fixed
for each of the FS states. In the $m$-th FS state the value of $\phi_i$ is
equal to an integer amount of flux quanta, $\phi_i =m\phi_0$. Two types of
single Josephson vortices carrying fluxes $\phi_0$ or/and $\phi_0/2$ can exist
in the FS states. Specific stepwise resonances in the current-voltage
characteristics are caused by periodic motion of these vortices between the
edges of the junction.


title:
Electroweak symmetry breaking and cold dark matter from strongly
  interacting hidden sector

abstract:
  We consider a hidden sector with a vectorlike confining gauge theory like QCD
with $N_{h,c}$ colors and $N_{h,f}$ light quarks ${\cal Q}_h$ in the hidden
sector. Then a scale $\Lambda_H$ would be generated by dimensional
transmutation, and chiral symmetry breaking occurs in the hidden sector. This
scale $\Lambda_H$ can play a role of the SM Higgs mass parameter, triggering
electroweak symmetry breaking (EWSB). Furthermore the lightest mesons in the
hidden sector is stable by flavor conservation of the hidden sector strong
interaction, and could be a good cold dark matter (CDM). We study collider
phenomenology, and relic density and direct detection rates of the CDM of this
model.


title:
Relaxation dynamics of aftershocks after large volatility shocks in the
  SSEC index

abstract:
  The relaxation dynamics of aftershocks after large volatility shocks are
investigated based on two high-frequency data sets of the Shanghai Stock
Exchange Composite (SSEC) index. Compared with previous relevant work, we have
defined main financial shocks based on large volatilities rather than large
crashes. We find that the occurrence rate of aftershocks with the magnitude
exceeding a given threshold for both daily volatility (constructed using
1-minute data) and minutely volatility (using intra-minute data) decays as a
power law. The power-law relaxation exponent increases with the volatility
threshold and is significantly greater than 1. Taking financial volatility as
the counterpart of seismic activity, the power-law relaxation in financial
volatility deviates remarkably from the Omori law in Geophysics.


title: Surface solitons in left-handed metamaterials

abstract:
  A theory of self-induced transparency of surface TM-mode propagating along a
interface separating conventional and left-handed metamaterials is developed. A
transition layer sandwiched between connected media is described using a model
of a two-dimensional gas of quantum dots. Explicit analytical expressions for a
surface optical soliton in the presence of single and biexciton transitions,
depending on the magnetic permeability of the left-handed medium, are obtained
with realistic parameters which can be reached in current experiments. It is
shown that the sign of the total energy flow the surface mode depends on the
material parameters of the quantum dots and the connected media.


title:
Anomalous Lineshapes and Aging Effects in Two-Dimensional Correlation
  Spectroscopy

abstract:
  Multitime correlation functions provide useful probes for the ensembles of
trajectories underlying the stochastic dynamics of complex systems. These can
be obtained by measuring their optical response to sequences of ultrashort
optical pulse. Using the continuous time random walk model for spectral
diffusion, we analyze the signatures of anomalous relaxation in two-dimensional
four wave mixing signals. Different models which share the same two point joint
probability distribution show markedly different lineshapes and may be
distinguished. Aging random walks corresponding to waiting time distributions
with diverging first moment show dependence of 2D lineshapes on initial
observation time, which persist for long times.


title: Energetic Electrons and Nuclear Transmutations in Exploding Wires

abstract:
  Nuclear transmutations and fast neutrons have been observed to emerge from
large electrical current pulses passing through wire filaments which are
induced to explode. The nuclear reactions may be explained as inverse beta
transitions of energetic electrons absorbed either directly by single protons
in Hydrogen or by protons embedded in other more massive nuclei. The critical
energy transformations to the electrons from the electromagnetic field and from
the electrons to the nuclei are best understood in terms of coherent collective
motions of the many flowing electrons within a wire filament. Energy
transformation mechanisms have thus been found which settle a theoretical
paradox in low energy nuclear reactions which has remained unresolved for over
eight decades. It is presently clear that nuclear transmutations can occur
under a much wider range of physical conditions than was heretofore thought
possible.


title:
Group-theoretic Methods for Bounding the Exponent of Matrix
  Multiplication

abstract:
  The (asymptotic) complexity of matrix multiplication (over the complex field)
is measured by a real parameter w > 0, called the exponent of matrix
multiplication (over the complex field), which is defined to be the smallest
real number w > 0 such that for an arbitrary degree of precision > 0, two n by
n complex matrices can be multiplied using an algorithm using O(n^(w+\epsilon))
number of non-division arithmetical operations. By the standard algorithm for
multiplying two matrices, the trivial lower and upper bounds for the exponent w
are 2 and 3 respectively.
  W. Strassen in 1969 obtained the first important result that w < 2.81 using
his result that 2 by 2 matrix multiplication could be performed using 7
multiplications, not 8, as in the standard algorithm. In 1984, V. Pan improved
this to 2.67, using a variant of Strassen's approach. It has been conjectured
that w = 2, but the best known result is that w < 2.38, due to D. Coppersmith
and S. Winograd. In all these approaches, estimates for w depend on the number
of main running steps in their algorithms.
  In a recent series of papers in 2003 and 2005, H. Cohn and C. Umans put
forward an entirely different approach using fairly elementary methods
involving finite groups, group algebras and their representations. The author
describes and proves their main results, and suggests possible ways of getting
improved estimates for the exponent using their methods.


title: Magnetized strange quark matter and magnetized strange quark stars

abstract:
  Strange quark matter could be found in the core of neutron stars or forming
strange quark stars. As is well known, these astrophysical objects are endowed
with strong magnetic fields which affect the microscopic properties of matter
and modify the macroscopic properties of the system. In this paper we study the
role of a strong magnetic field in the thermodynamical properties of a
magnetized degenerate strange quark gas, taking into account beta-equilibrium
and charge neutrality. Quarks and electrons interact with the magnetic field
via their electric charges and anomalous magnetic moments. In contrast to the
magnetic field value of 10^19 G, obtained when anomalous magnetic moments are
not taken into account, we find the upper bound B < 8.6 x 10^17 G, for the
stability of the system. A phase transition could be hidden for fields greater
than this value.


title: Holographic phase transitions at finite chemical potential

abstract:
  Recently holographic techniques have been used to study the thermal
properties of N=2 super-Yang-Mills theory, with gauge group SU(Nc) and coupled
to Nf << Nc flavours of fundamental matter, at large Nc and large 't Hooft
coupling. Here we consider the phase diagram as a function of temperature and
baryon chemical potential mu. For fixed mu < Nc Mq there is a line of first
order thermal phase transitions separating a region with vanishing baryon
density and one with nonzero density. For fixed mu > Nc Mq there is no phase
transition as a function of the temperature and the baryon density is always
nonzero. We also compare the present results for the grand canonical ensemble
with those for canonical ensemble in which the baryon density is held fixed
[1].


title: On the implications of a dilaton in gauge theory

abstract:
  Some recent work on the implications of a dilaton in 4d gauge theories are
revisited. In part I of this paper we see how an effective dilaton coupling to
gauge kinetic term provides a simple attractive mechanism to generate
confinement. In particular, we put emphasis on the derivation of confining
analytical solutions and look into the problem how dilaton degrees of freedom
modify Coulom potential and when a confining phase occurs. In part II, we solve
the semi-relativistic wave equation, for Dick interquark potential using the
Shifted l-expansion technique (SLET) in the heavy quarkonium sector. The
results of this phenomenological analysis proves that these effective theories
can be relevant to model quark confinement and may shed some light on
confinement mechanism.


title:
Efficient Algorithms for Node Disjoint Subgraph Homeomorphism
  Determination

abstract:
  Recently, great efforts have been dedicated to researches on the management
of large scale graph based data such as WWW, social networks, biological
networks. In the study of graph based data management, node disjoint subgraph
homeomorphism relation between graphs is more suitable than (sub)graph
isomorphism in many cases, especially in those cases that node skipping and
node mismatching are allowed. However, no efficient node disjoint subgraph
homeomorphism determination (ndSHD) algorithms have been available. In this
paper, we propose two computationally efficient ndSHD algorithms based on state
spaces searching with backtracking, which employ many heuristics to prune the
search spaces. Experimental results on synthetic data sets show that the
proposed algorithms are efficient, require relative little time in most of the
testing cases, can scale to large or dense graphs, and can accommodate to more
complex fuzzy matching cases.


title: Koszul duality for Operads

abstract:
  This is a copy of the article by the same authors published in Duke Math. J.
(1994).


title: Outer Billiards on Kites

abstract:
  Outer billiards is a simple dynamical system based on a convex planar shape.
The Moser-Neumann question, first posed by B.H. Neumann around 1960, asks if
there exists a planar shape for which outer billiards has an unbounded orbit.
The first half of this monograph proves that outer billiards has an unbounded
orbit defined relative to any irrational kite. The second half of the monograph
gives a very sharp description of the set of unbounded orbits, both in terms of
the dynamics and the Hausdorff dimension. The analysis in both halves reveals a
close connection between outer billiards on kites and the modular group, as
well as connections to self-similar tilings, polytope exchange maps,
Diophantine approximation, and odometers.


title: Exciton formation in graphene bilayer

abstract:
  Exciton instability in graphene bilayer systems is studied in the case of a
short-ranged Coulomb interaction and a finite voltage difference between the
layers. Self-consistent exciton gap equations are derived and solved
numerically and analytically under controlled approximation. We obtain that a
critical strength of the Coulomb interaction exists for the formation of
excitons. The critical strength depends on the amount of voltage difference
between the layers and on the inter-layer hopping parameter.


title:
Connexions with totally skew-symmetric torsion and nearly-Kaehler
  geometry

abstract:
  We study almost Hermitian structures admitting a Hermitian connexion with
totally skew-symmetric torsion or equivalently, those almost Hermitian
structures with totally skew-symmetric Nijenhuis tensor. We investigate up to
what extent the Nijenhuis tensor fails to be parallel with respect to the
characteristic connexion. This is naturally described by means of an extension
of the notion of Killing form to almost Hermitian geometry. In this context, we
also make an essentially self-contained survey of nearly-Kaehler geometry, but
from the perspective of non-integrable holonomy systems.


title:
Functional determinants for general self-adjoint extensions of
  Laplace-type operators resulting from the generalized cone

abstract:
  In this article we consider the zeta regularized determinant of Laplace-type
operators on the generalized cone. For {\it arbitrary} self-adjoint extensions
of a matrix of singular ordinary differential operators modelled on the
generalized cone, a closed expression for the determinant is given. The result
involves a determinant of an endomorphism of a finite-dimensional vector space,
the endomorphism encoding the self-adjoint extension chosen. For particular
examples, like the Friedrich's extension, the answer is easily extracted from
the general result. In combination with \cite{BKD}, a closed expression for the
determinant of an arbitrary self-adjoint extension of the full Laplace-type
operator on the generalized cone can be obtained.


title: Confinement and the second vortex of the SU(4) gauge group

abstract:
  We study the potential between static SU(4) sources using the Model of Thick
Center Vortices. Such vortices are characterized by the center elements
$z_1=\mathrm i$ and $z_2=z_1^2$. Fitting the ratios of string tensions to those
obtained in Monte-Carlo calculations of lattice QCD we get $f_2>f_1^2$, where
$f_n$ is the probability that a vortex of type $n$ is piercing a plaquette.
Because of $z_2=z_1^2$ vortices of type two are overlapping vortices of type
one. Therefore, $f_2>f_1^2$ corresponds to the existence of an attractive force
between vortices of type one.


title:
A constrained-transport magnetohydrodynamics algorithm with
  near-spectral resolution

abstract:
  Numerical simulations including magnetic fields have become important in many
fields of astrophysics. Evolution of magnetic fields by the constrained
transport algorithm preserves magnetic divergence to machine precision, and
thus represents one preferred method for the inclusion of magnetic fields in
simulations. We show that constrained transport can be implemented with
volume-centered fields and hyperresistivity on a high-order finite difference
stencil. Additionally, the finite-difference coefficients can be tuned to
enhance high-wavenumber resolution. Similar techniques can be used for the
interpolations required for dealiasing corrections at high wavenumber.
Together, these measures yield an algorithm with a wavenumber resolution that
approaches the theoretical maximum achieved by spectral algorithms. Because
this algorithm uses finite differences instead of fast Fourier transforms, it
runs faster and isn't restricted to periodic boundary conditions. Also, since
the finite differences are spatially local, this algorithm is easily scalable
to thousands of processors. We demonstrate that, for low-Mach-number
turbulence, the results agree well with a high-order, non-constrained-transport
scheme with Poisson divergence cleaning.


title: Monotonicity for entrywise functions of matrices

abstract:
  We characterize real functions $f$ on an interval $(-\alpha,\alpha)$ for
which the entrywise matrix function $[a_{ij}] \mapsto [f(a_{ij})]$ is positive,
monotone and convex, respectively, in the positive semidefiniteness order.
Fractional power functions are exemplified and related weak majorizations are
shown.


title:
The metal abundance of circumnuclear star forming regions in early type
  spirals. Spectrophotometric observations

abstract:
  We have obtained long-slit observations in the optical and near infrared of
12 circumnuclear HII regions (CNSFR) in the early type spiral galaxies NGC
2903, NGC 3351 and NGC 3504 with the aim of deriving their chemical abundances.
Only for one of the regions, the [SIII] $\lambda$ 6312 \AA was detected
providing, together with the nebular [SIII] lines at $\lambda\lambda$ 9069,
9532 \AA, a value of the electron temperature of T$_e$([SIII])= 8400$^{+
4650}_{-1250}$K. A semi-empirical method for the derivation of abundances in
the high metallicity regime is presented.
  We obtain abundances which are comparable to those found in high metallicity
disc HII regions from direct measurements of electron temperatures and
consistent with solar values within the errors. The region with the highest
oxygen abundance is R3+R4 in NGC 3504, 12+log(O/H) = 8.85, about 1.5 solar if
the solar oxygen abundance is set at the value derived by Asplund et al.
(2005), 12+log(O/H)$_{\odot}$ = 8.66$\pm$0.05. Region R7 in NGC 3351 has the
lowest oxygen abundance of the sample, about 0.6 times solar. In all the
observed CNSFR the O/H abundance is dominated by the O$^+$/H$^+$ contribution,
as is also the case for high metallicity disc HII regions. For our observed
regions, however, also the S$^+$/S$^{2+}$ ratio is larger than one, contrary to
what is found in high metallicity disc HII regions for which, in general, the
sulphur abundances are dominated by S$^{2+}$/H$^+$...


title: Transition rates for a S \ge 1 model coupled to a phonon bath

abstract:
  We investigate transition rates between different spin configurations for $S
\ge 1$ spins weakly coupled to a $d$-dimensional phonon bath. This study is
motivated by understanding observed magnetization relaxation as a function of
temperature in diverse magnetic systems such as arrays of magnetic
nanoparticles and magnetic molecules. We assume that the magnetization of the
spin system relaxes through consecutive emission or absorption of a single
phonon. From a weak, linear spin-phonon coupling Hamiltonian, we derive
transition rates that would be used to examine dynamic properties of the system
in kinetic Monte Carlo simulations. Although the derived phonon-assisted
transition rates satisfy detailed balance, in the case of two and three
dimensional phonon baths, transitions between degenerate states are not
allowed. Thus, if there are no alternative paths along which the spin system
can relax, the relaxation time diverges. Otherwise, the system finds other
paths, which leads to an increase in the relaxation time and energy barrier.
However, when higher-order phonon processes are included in the transition
rates, it is found that the system can reach the states which were inaccessible
due to the forbidden transitions. As a result, the system recovers some of the
dynamic properties obtained using the Glauber transition rate.


title:
Corrections to the fine structure constant in higher dimensional global
  monopole spacetime

abstract:
  In this paper we use the Generalized Uncertainty Principle in order to obtain
the corrections to the fine structure constant in (D+1)-dimensional global
monopole spacetime. The result is particularized to D-dimensional spacetime. We
also discuss the particular case D=3 corresponding to the (3+1)-dimensional
global monopole spacetime.


title:
Bridging over p-wave pi-production and weak processes in few-nucleon
  systems with chiral perturbation theory

abstract:
  I study an aspect of chiral perturbation theory (\chi PT) which enables one
to ``bridge'' different reactions. That is, an operator fixed in one of the
reactions can then be used to predict the other. For this purpose, I calculate
the partial wave amplitude for the p-wave pion production (pp\to pn\pi^+) using
the pion production operator from the lowest and the next nonvanishing orders.
The operator includes a contact operator whose coupling has been fixed using a
matrix element of a low-energy weak process (pp\to de^+\nu_e). I find that this
operator does not reproduce the partial wave amplitude extracted from
experimental data, showing that the bridging over the reactions with
significantly different kinematics is not necessarily successful. I study the
dependence of the amplitude on the various inputs such as the NN potential, the
\pi N\Delta coupling, and the cutoff. I argue the importance of a higher order
calculation. In order to gain an insight into a higher order calculation, I add
a higher order counter term to the operator used above, and fit the couplings
to both the low-energy weak process and the pion production. The energy
dependence of the partial wave amplitude for the pion production is described
by the operator consistently with the data. However, I find a result which
tells us to be careful about the convergence of the chiral expansion for the
pp\to pn\pi^+ reaction.


title: Generalized Second Law and phantom Cosmology: accreting black holes

abstract:
  The accretion of phantom fields by black holes within a thermodynamic context
is addressed. For a fluid violating the dominant energy condition, case of a
phantom fluid, the Euler and Gibbs relations permit two different possibilities
for the entropy and temperature: a situation in which the entropy is negative
and the temperature is positive or vice-versa. In the former case, if the
generalized second law (GSL) is valid, then the accretion process is not
allowed whereas in the latter, there is a critical black hole mass below which
the accretion process occurs. In a universe dominated by a phantom field, the
critical mass drops quite rapidly with the cosmic expansion and black holes are
only slightly affected by accretion. All black holes disappear near the big
rip, as suggested by previous investigations, if the GSL is violated.


title: Homotopically non-trivial maps with small k-dilation

abstract:
  We construct homotopically non-trivial maps from S^m to S^n with arbitrarily
small 3-dilation for certain pairs (m,n). The simplest example is m=4, n=3.
Other examples include arbitrarily large values of m and n. We show that a
homotopy class in pi_7(S^4) can be represented by maps with arbitrarily small
4-dilation if and only if the class is torsion.


title: Noise from metallic surfaces -- effects of charge diffusion

abstract:
  Non-local electrodynamic models are developed for describing metallic
surfaces for a diffusive metal. The electric field noise at a distance z_0 from
the surface is evaluated and compared with data from ion chips that show
anomalous heating with a noise power decaying as z_0^{-4}. We find that high
surface diffusion can account for the latter result.


title: The existence of two closed geodesics on every Finsler 2-sphere

abstract:
  In this paper, we prove that for every Finsler metric on the 2-dimensional
sphere there exist at least two distinct prime closed geodesics. For the case
of the two-sphere, this solves an open problem posed by D. V. Anosov in 1974.


title:
Scaling of Anisotropic Flows and Nuclear Equation of State in
  Intermediate Energy Heavy Ion Collisions

abstract:
  Elliptic flow ($v_2$) and hexadecupole flow ($v_4$) of light clusters have
been studied in details for 25 MeV/nucleon $^{86}$Kr + $^{124}$Sn at large
impact parameters by Quantum Molecular Dynamics model with different potential
parameters. Four parameter sets which include soft or hard equation of state
(EOS) with/without symmetry energy term are used. Both number-of-nucleon ($A$)
scaling of the elliptic flow versus transverse momentum ($p_t$) and the scaling
of $v_4/A^{2}$ versus $(p_t/A)^2$ have been demonstrated for the light clusters
in all above calculation conditions. It was also found that the ratio of
$v_4/{v_2}^2$ keeps a constant of 1/2 which is independent of $p_t$ for all the
light fragments. By comparisons among different combinations of EOS and
symmetry potential term, the results show that the above scaling behaviors are
solid which do not depend the details of potential, while the strength of flows
is sensitive to EOS and symmetry potential term.


title:
Comparison of elastic electron or positron scattering from proton-rich
  nuclei

abstract:
  We investigate the cross sections of the elastic electron or positron
scattering from $^{208}$Pb, $^{12}$C, $^{12,16}$O and $^{28, 32}$S by the
relativistic partial-wave expansion method using the static charge density
distribution from the self-consistent relativistic mean field model and also
calculate the charge form factor for $^{12, 16}$O and $^{28, 32}$S. The
numerical results are compared with the available data. Calculations indicate
that the extended charge density distributions of $^{12}$O and $^{28}$S have
observable effects on the cross sections of the electron or positron scattering
as well as the charge form factors.


title:
Andreev Reflection in Heavy-Fermion Superconductors and Order Parameter
  Symmetry in CeCoIn_5

abstract:
  Differential conductance spectra are obtained from nanoscale junctions on the
heavy-fermion superconductor CeCoIn$_5$ along three major crystallographic
orientations. Consistency and reproducibility of characteristic features among
the junctions ensure their spectroscopic nature. All junctions show a similar
conductance asymmetry and Andreev reflection-like conductance with reduced
signal (~ 10%-13%), both commonly observed in heavy-fermion superconductor
junctions. Analysis using the extended Blonder-Tinkham-Klapwijk model indicates
that our data provide the first spectroscopic evidence for $d_{x^2-y^2}$
symmetry. To quantify our conductance spectra, we propose a model by
considering the general phenomenology in heavy fermions, the two-fluid
behavior, and an energy-dependent density of states. Our model fits to the
experimental data remarkably well and should invigorate further investigations.


title: The Hopf invariant and simplex straightening

abstract:
  Let M be a closed 3-manifold which can be triangulated with N simplices. We
prove that any map from M to a genus 2 surface has Hopf invariant at most C^N.
Let X be a closed oriented hyperbolic 3-manifold with injectivity radius less
than epsilon at one point. If there is a degree non-zero map from M to X, then
we prove that epsilon is at least C^{-N}.


title:
Gli Strumenti Scientifici di Interesse Storico di tre antiche Scuole
  Medie Superiori di Bergamo ("Lussana", "Vittorio Emanuele", e "Quarenghi")

abstract:
  Wherever old Universities exist [in Europe, for example: Italy being not the
last one], there can be found Scientific Instruments of Historical Interest,
e.g., for Physics -which is the case we are concerned with here;- even if
proper attention has been paid to such an exceptional heritage only during the
last half a century. [We studied ourselves the material existing at the
University of Catania, Catania, Italy, almost 600 years old]. However, even
where ancient universities do not exist, a lot of Historical Scientific
Instruments are often owned by the local Senior High Schools. By the present
"small book" we want to make known the antique physics instruments that are in
possession of three Senior High Schools of Bergamo, Italy: the "Istituto
Tecnico Vittorio Emanuele", the "Liceo Scientifico Lussana", and the "Istituto
per Geometri Quarenghi". Namely, we catalogue and describe: 61 instruments of
the "Vittorio Emanuele" (52 of the second half of the XIX century, and 9 of the
first half of the XX century); 100 instruments of the "Lussana" (belonging
essentially to the first half of the XX century); and 26 instruments, mainly
topographical in this case, of the "Quarenghi" (8 of the second half of the XIX
century, and 16 of the first half of the XX century); without forgetting to add
suitable explanations about their functioning. Our aim will be reached if we
happen to stimulate other colleagues to perform similar work in their towns.
The present small book is in Italian, but it contains fifty-one (51)
self-explanatory photographs in color, and nineteen (19) black-and-white
sketches. Actually, we can put in the Archives this small book, instead of
others, also because -with the help of the typesetter- we eventually suceeded
in reducing its whole size to less than 1 M-b.


title: Emergence of Symmetry in Complex Networks

abstract:
  Many real networks have been found to have a rich degree of symmetry, which
is a very important structural property of complex network, yet has been rarely
studied so far. And where does symmetry comes from has not been explained. To
explore the mechanism underlying symmetry of the networks, we studied
statistics of certain local symmetric motifs, such as symmetric bicliques and
generalized symmetric bicliques, which contribute to local symmetry of
networks. We found that symmetry of complex networks is a consequence of
similar linkage pattern, which means that nodes with similar degree tend to
share similar linkage targets. A improved version of BA model integrating
similar linkage pattern successfully reproduces the symmetry of real networks,
indicating that similar linkage pattern is the underlying ingredient that
responsible for the emergence of the symmetry in complex networks.


title:
Strongly Resonant Transmission of Electromagnetic Radiation in Periodic
  Anisotropic Layered Media

abstract:
  The electromagnetic dispersion in periodic layered media can be tailored and
their resonant properties can be considerably improved by utilizing anisotropic
materials. Periodic structures with a photonic band edge split into two parts,
or so-called split band edge, exhibit superior resonant properties including
exceptionally high Q-values of transmission resonances and nearly perfect
impedance matching at the boundaries, even when the number of unit cells N is
not large. A microwave transmission resonance with Q~220 is demonstrated in a
periodic stack of form-birefringent layers with N=12 realized in a waveguide
geometry.


title: Geomagnetic Field Effects on the Imaging Air Shower Cherenkov Technique

abstract:
  Imaging Air Cherenkov Telescopes (IACTs) detect the Cherenkov light flashes
of Extended Air Showers (EAS) triggered by very high energy (VHE) gamma-rays
impinging on the Earth's atmosphere. Due to the overwhelming background from
hadron induced EAS, the discrimination of the rare gamma-like events is rather
difficult, in particular at energies below 100 GeV. The influence of the
Geomagnetic Field (GF) on the EAS development can further complicate this
discrimination and, in addition, also systematically affect the gamma
efficiency and energy resolution of an IACT. Here we present the results from
dedicated Monte Carlo (MC) simulations for the MAGIC telescope site.
Additionally we show that measurements of sub-TeV gamma-rays from the Crab
nebula are affected even for a low GF strength of less than 33 micro Tesla.


title: The Geometry of Toric Hyperk\"ahler Varieties

abstract:
  In this survey article we describe the geometry of toric hyperk\"ahler
varieties, which are hyperk\"ahler quotients of the quaternionic vector spaces
by tori. In particular, we discuss the Betti numbers, the cohomology ring, and
variation of hyperk\"ahler structures of these spaces with many improved
results and proofs.


title: The Entire Cyclic Cohomology of Noncommutative 2-Tori

abstract:
  Our aim in this paper is to compute the entire cyclic cohomology of
noncommutative 2-tori. First of all, we clarify their algebraic structure of
noncommutative 2-tori as a $F^*$-algebra, according to the idea of
Elliott-Evans. Actually, they are the inductive limit of subhomogeneous
$F^*$-algebras. Using such a result, we compute their entire cyclic cohomology,
which is isomorphic to their periodic one as a complex vector space.


title: Z+(4430) as a cusp in D*(2010)Dbar_1(2420)

abstract:
  The Z^+(4430) observed by Belle is explained naturally as a threshold cusp in
the D*(2010)Dbar_1(2420) system.


title: Local structure of algebraic monoids

abstract:
  We describe the local structure of an irreducible algebraic monoid $M$ at an
idempotent element $e$. When $e$ is minimal, we show that $M$ is an induced
variety over the kernel $MeM$ (a homogeneous space) with fibre the two-sided
stabilizer $M_e$ (a connected affine monoid having a zero element and a dense
unit group). This yields the irreducibility of stabilizers and centralizers of
idempotents when $M$ is normal, and criteria for normality and smoothness of an
arbitrary $M$. Also, we show that $M$ is an induced variety over an abelian
variety, with fiber a connected affine monoid having a dense unit group.


title: Experiments needed in Meson and Baryon Spectroscopy

abstract:
  Three (or four) straightforward experiments would contribute greatly to
completing the spectroscopy of baryons and light mesons. In the baryon sector,
data are needed on inelastic reactions from a polarised target with pi and kaon
beams up to 3 GeV/c. Similar data are needed in the light meson sector for
pbar-p interactions in the momentum range 0.3 to 2 GeV/c. In both cases,
valuable information is to be obtained from longitudinal (L) and sideways (S)
target polarisations as well as the conventional normal (N) polarisation.
Thirdly, 3S_1 and 3D_1 mesons in the mass range 1 to 2.4 GeV/c could probably
be separated either by diffractive dissociation of transversely polarised
photons or by radiative return experiments using transversely and
longitudinally polarised electrons.