title: Canonical matrices of bilinear and sesquilinear forms

abstract:
  Canonical matrices are given for
  (a) bilinear forms over an algebraically closed or real closed field;
  (b) sesquilinear forms over an algebraically closed field and over real
quaternions with any nonidentity involution; and
  (c) sesquilinear forms over a field F of characteristic different from 2 with
involution (possibly, the identity) up to classification of Hermitian forms
over finite extensions of F.
  A method for reducing the problem of classifying systems of forms and linear
mappings to the problem of classifying systems of linear mappings is used to
construct the canonical matrices. This method has its origins in representation
theory and was devised in [V.V. Sergeichuk, Math. USSR-Izv. 31 (1988) 481-501].


title:
Skein Theory and Topological Quantum Registers: Braiding Matrices and
  Topological Entanglement Entropy of Non-Abelian Quantum Hall States

abstract:
  We study topological properties of quasi-particle states in the non-Abelian
quantum Hall states. We apply a skein-theoretic method to the Read--Rezayi
state whose effective theory is the SU(2)_K Chern--Simons theory. As a
generalization of the Pfaffian (K=2) and the Fibonacci (K=3) anyon states, we
compute the braiding matrices of quasi-particle states with arbitrary spins.
Furthermore we propose a method to compute the entanglement entropy
skein-theoretically. We find that the entanglement entropy has a nontrivial
contribution called the topological entanglement entropy which depends on the
quantum dimension of non-Abelian quasi-particle intertwining two subsystems.


title:
Distributed Decision Through Self-Synchronizing Sensor Networks in the
  Presence of Propagation Delays and Asymmetric Channels

abstract:
  In this paper we propose and analyze a distributed algorithm for achieving
globally optimal decisions, either estimation or detection, through a
self-synchronization mechanism among linearly coupled integrators initialized
with local measurements. We model the interaction among the nodes as a directed
graph with weights (possibly) dependent on the radio channels and we pose
special attention to the effect of the propagation delay occurring in the
exchange of data among sensors, as a function of the network geometry. We
derive necessary and sufficient conditions for the proposed system to reach a
consensus on globally optimal decision statistics. One of the major results
proved in this work is that a consensus is reached with exponential convergence
speed for any bounded delay condition if and only if the directed graph is
quasi-strongly connected. We provide a closed form expression for the global
consensus, showing that the effect of delays is, in general, the introduction
of a bias in the final decision. Finally, we exploit our closed form expression
to devise a double-step consensus mechanism able to provide an unbiased
estimate with minimum extra complexity, without the need to know or estimate
the channel parameters.


title:
The ILC Energy Requirements from the Constraints on New Boson Production
  at the Tevatron

abstract:
  Direct constraints on the masses of new heavy bosons by the Tevatron data are
discussed. Some excesses in the experimental data are interpreted as a
resonance production of new charged and `leptophobic' neutral chiral bosons
with masses around 500 GeV and 700 GeV, respectively. The interpretation was
provided on the basis of the theoretical model, proposed by the author about 15
years ago. New Tevatron data and the LHC results will definitely confirm or
reject this interpretation. The ILC with an energy above 1 TeV would be an
ideal place to produce and to study the properties of these particles.


title:
XMM-Newton observation of the deep minimum state of PG 2112+059: A
  spectrum dominated by reflection from the accretion disk?

abstract:
  We analyse a 75ks XMM-Newton observation of PG 2112+059 performed in November
2005 and compare it with a 15ks XMM-Newton observation taken in May 2003. PG
2112+059 was found in a deep minimum state as its 0.2-12 keV flux decreased by
a factor of 10 in comparison to the May 2003 observation. During the deep
minimum state the spectra show strong emission in excess of the continuum in
the 3-6 keV region. The excess emission corresponds to an EW = 26.1 keV whereas
its shape resembles that of heavily absorbed objects. The spectra of both
observations of PG 2112+059 can be explained statistically by a combination of
two absorbers where one shows a high column density, $N_{H} \sim 4.5 \times
10^{23} cm^{-2}$, and the other high ionisation parameters. As the ionisation
parameter of the high flux state, $\xi \sim 34 erg cm s^{-1}$, is lower than
the value found for the deep minimum state, $\xi \sim 110 erg cm s^{-1}$,
either the absorbers are physically different or the absorbing material is
moving with respect to the X-ray source. The spectra can also be explained by a
continuum plus X-ray ionised reflection on the accretion disk, seen behind a
warm absorber. The ionisation parameter of the high state ($\xi \sim 5.6 erg cm
s^{-1}$) is higher than the ionisation parameter of the deep minimum state
($\xi \sim 0.2 erg cm s^{-1}$), as expected for a stationary absorber. The
values found for the ionisation parameters are in the range typical for AGNs.
The spectra observed during the deep minimum state are reflection dominated and
show no continuum emission. These can be understood in the context of light
bending near the supermassive black hole as predicted by Minutti and Fabian.


title: Hom-Lie admissible Hom-coalgebras and Hom-Hopf algebras

abstract:
  The aim of this paper is to generalize the concept of Lie-admissible
coalgebra introduced by Goze and Remm to Hom-coalgebras and to introduce
Hom-Hopf algebras with some properties. These structures are based on the
Hom-algebra structures introduced by the authors.


title: Dynamical Constraints on the Cosmological Parameters

abstract:
  In cosmology, the cosmic curvature $K$ and the cosmological constant
$\Lambda$ are two important parameters, and the values have strong influence on
the behavior of the universe. In the context of normal cosmology, under the
ordinary assumptions of positive mass-energy and initial negative pressure, we
find the initial singularity of the universe is certainly absent and we have
$K=1$. This means total spatial structure of the universe should be a
3-dimensional sphere $S^3$. For the cyclic cosmological model, we have
$\Lambda\lesssim 10^{-24} {\rm ly}^{-2}$. Obviously, such constraints would be
helpful for the researches on the properties of dark matter and dark energy in
cosmology.


title:
Maxwell equations in Riemannian space-time, geometry effect on material
  equations in media

abstract:
  The known possibility to consider the (vacuum) Maxwell equations in a curved
space-time as Maxwell equations in flat space-time(Mandel'stam L.I., Tamm I.E.)
taken in an effective media the properties of which are determined by metrical
structure of the curved model is studied. Metrical structure of the curved
space-time generates effective constitutive equations for electromagnetic
fields, the form of four corresponding symmetrical tensors is found explicitly
for general case of an arbitrary Riemannian space - time. Four constitutive
tensors are not independent and obey some additional constraints between them.
Several simple examples are specified in detail:itis given geometrical modeling
of the anisotropic media (magnetic crystals) and the geometrical modeling of a
uniform media in moving reference frame in the Minkowsky electrodynamics -- the
latter is realized trough the use of a non-diagonal metrical tensor determined
by 4-vector velocity of the moving uniform media. Also the effective material
equations generated by geometry of space of constant curvature (Lobachevsky and
Riemann models) are determined.


title: Measuring Volatility Clustering in Stock Markets

abstract:
  We propose a novel method to quantify the clustering behavior in a complex
time series and apply it to a high-frequency data of the financial markets. We
find that regardless of used data sets, all data exhibits the volatility
clustering properties, whereas those which filtered the volatility clustering
effect by using the GARCH model reduce volatility clustering significantly. The
result confirms that our method can measure the volatility clustering effect in
financial market.


title:
The solar chromosphere at high resolution with IBIS. I. New insights
  from the Ca II 854.2 nm line

abstract:
  (Abridged)
  Aims: In this paper, we seek to establish the suitability of imaging
spectroscopy performed in the Ca II 854.2 nm line as a means to investigate the
solar chromosphere at high resolution.
  Methods: We utilize monochromatic images obtained with the Interferometric
BIdimensional Spectrometer (IBIS) at multiple wavelengths within the Ca II
854.2 nm line and over several quiet areas. We analyze both the morphological
properties derived from narrow-band monochromatic images and the average
spectral properties of distinct solar features such as network points,
internetwork areas and fibrils.
  Results: The spectral properties derived over quiet-Sun targets are in full
agreement with earlier results obtained with fixed-slit spectrographic
observations, highlighting the reliability of the spectral information obtained
with IBIS. Furthermore, the very narrowband IBIS imaging reveals with much
clarity the dual nature of the Ca II 854.2 nm line: its outer wings gradually
sample the solar photosphere, while the core is a purely chromospheric
indicator. The latter displays a wealth of fine structures including bright
points, akin to the Ca II H2V and K2V grains, as well as fibrils originating
from even the smallest magnetic elements. The fibrils occupy a large fraction
of the observed field of view even in the quiet regions, and clearly outline
atmospheric volumes with different dynamical properties, strongly dependent on
the local magnetic topology. This highlights the fact that 1-D models
stratified along the vertical direction can provide only a very limited
representation of the actual chromospheric physics.


title:
The theoretical DFT study of electronic structure of thin Si/SiO2
  quantum nanodots and nanowires

abstract:
  The atomic and electronic structure of a set of proposed thin (1.6 nm in
diameter) silicon/silica quantum nanodots and nanowires with narrow interface,
as well as parent metastable silicon structures (1.2 nm in diameter), was
studied in cluster and PBC approaches using B3LYP/6-31G* and PW PP LDA
approximations. The total density of states (TDOS) of the smallest
quasispherical silicon quantum dot (Si85) corresponds well to the TDOS of the
bulk silicon. The elongated silicon nanodots and 1D nanowires demonstrate the
metallic nature of the electronic structure. The surface oxidized layer opens
the bandgap in the TDOS of the Si/SiO2 species. The top of the valence band and
the bottom of conductivity band of the particles are formed by the silicon core
derived states. The energy width of the bandgap is determined by the length of
the Si/SiO2 clusters and demonstrates inverse dependence upon the size of the
nanostructures. The theoretical data describes the size confinement effect in
photoluminescence spectra of the silica embedded nanocrystalline silicon with
high accuracy.


title: Gravitational Higgs Mechanism with a Topological Term

abstract:
  We investigate the Higgs mechanism for gravity, which has been recently put
forward by 't Hooft, when the Polyakov-type action for scalar fields is added
to the original action. We find that from the Polyakov-type action, it is very
natural to derive an 'alternative' metric tensor composed of the scalar fields.
The positivity condition on the determinant can be also derived easily by
requiring that this term does not change the dynamics at all and becomes a
topological number, that is, the wrapping number. It turns out that the gauge
conditions adopted by 't Hooft are nothing but the restriction on a sector with
unit wrapping number.


title:
Gamete recognition and complementary haplotypes in sexual Penna ageing
  model

abstract:
  In simulations of sexual reproduction with diploid individuals, we introduce
that female haploid gametes recognize one specific allele of the genomes as a
marker of the male haploid gametes. They fuse to zygotes preferrably with male
gametes having a different marker than their own. This gamete recognition
enhances the advantage of complementary bit-strings in the simulated diploid
individuals, at low recombination rates. Thus with rare recombinations the
bit-string evolve to be complementary; with recombination rate above about 0.1
instead they evolve under Darwinian purification selection, with few bits
mutated.


title:
The Araucaria Project. Near-Infrared Photometry of Cepheid Variables in
  the Sculptor Galaxy NGC 55

abstract:
  We have obtained deep images in the near-infrared J and K filters of four
fields in the Sculptor Group spiral galaxy NGC 55 with the ESO VLT and ISAAC
camera. For 40 long-period Cepheid variables in these fields which were
recently discovered by Pietrzy{\'n}ski et al., we have determined mean J and K
magnitudes from observations at two epochs, and derived distance moduli from
the observed PL relations in these bands. Using these values together with the
previously measured distance moduli in the optical V and I bands, we have
determined a total mean reddening of the NGC 55 Cepheids of E(B-V)=0.127 $\pm$
0.019 mag, which is mostly produced inside NGC 55 itself. For the true distance
modulus of the galaxy, our multiwavelength analysis yields a value of 26.434
$\pm$ 0.037 mag (random error), corresponding to a distance of 1.94 $\pm$ 0.03
Mpc. This value is tied to an adopted true LMC distance modulus of 18.50 mag.
The systematic uncertainty of our derived Cepheid distance to NGC 55 (apart
from the uncertainty on the adopted LMC distance) is $\pm$4%, with the main
contribution likely to come from the effect of blending of some of the Cepheids
with unresolved companion stars. The distance of NGC 55 derived from our
multiwavelength Cepheid analysis agrees within the errors with the distance of
NGC 300, strengthening the case for a physical association of these two
Sculptor Group galaxies.


title:
Characterization of the Core-Shell Nanoparticles Formed as Soluble
  Hydrogen-Bonding Interpolymer Complexes at low pH

abstract:
  The formation of soluble hydrogen-bonding interpolymer complexes between
poly(acrylic acid) (PAA) and poly(acrylic
acid-co-2-acrylamido-2-methyl-1-propane sulfonic acid)-graft-poly(N, N
dimethylacrylamide) (P(AA-co-AMPSA)-g-PDMAM) at pH = 2.0 was studied. A
viscometric study showed that in semidilute solution a physical gel is formed,
due to the interconnection of the anionic P(AA-co-AMPSA) backbone of the graft
copolymer, in a transient network, by means of the complexes formed between the
PDMAM side chains of the graft copolymer and PAA. Dynamic and static light
scattering measurements, in conjunction with small angle neutron scattering
measurements, suggest the formation of core-shell colloidal nanoparticles in
dilute solution, comprised by an insoluble PAA/PDMAM core surrounded by an
anionic P(AA-co-AMPSA) corona. Even if larger clusters are formed in semidilute
solution, the size of the insoluble core remains practically stable. Atomic
force microscopy performed under ambient conditions, reveal that the particles
collapse and flatten upon deposition on a substrate, with dimensions close to
the ones of the dry hydrophobic core.


title: Effectiveness of Measures of Performance During Speculative Bubbles

abstract:
  Statistical analysis of financial data most focused on testing the validity
of Brownian motion (Bm). Analysis performed on several time series have shown
deviation from the Bm hypothesis, that is at the base of the evaluation of many
financial derivatives. We inquiry in the behavior of measures of performance
based on maximum drawdown movements (MDD), testing their stability when the
underlying process deviates from the Bm hypothesis. In particular we consider
the fractional Brownian motion (fBm), and fluctuations estimated empirically on
raw market data. The case study of the rising part of speculative bubbles is
reported.


title:
Quantum path interference in the wavelength dependence of high-harmonic
  generation

abstract:
  We investigate the dependence of the intensity of radiation due to
high-harmonic generation (HHG) as a function of the wavelength of the
fundamental driver field. Superimposed on a smooth power-law dependence
observed previously we find surprisingly strong and rapid fluctuations on a
fine wavelength scale. We identify the origin of these fluctuations in terms of
quantum path interferences with up to five returning orbits significantly
contributing.


title: Detection of acceleration radiation in a Bose-Einstein condensate

abstract:
  We propose and study methods for detecting the Unruh effect in a
Bose-Einstein condensate. The Bogoliubov vacuum of a Bose-Einstein condensate
is used here to simulate a scalar field-theory, and accelerated atom dots or
optical lattices as means for detecting phonon radiation due to acceleration
effects. We study Unruh's effect for linear acceleration and circular
acceleration. In particular, we study the dispersive effects of the Bogoliubov
spectrum on the ideal case of exact thermalization. Our results suggest that
Unruh's acceleration radiation can be tested using current accessible
experimental methods.


title:
A realistic interpretation of quantum mechanics. Asymmetric random walks
  in a discrete spacetime

abstract:
  In this paper, I propose a realistic interpretation (RI) of quantum
mechanics, that is, an interpretation according to which a particle follows a
definite path in spacetime. The path is not deterministic but it is rather a
random walk. However, the probability of each step of the walk is found to
depend from some average properties of the particle that can be interpreted as
its propensity to have a certain macroscopic momentum and energy. The proposed
interpretation requires spacetime to be discrete. Prediction of standard
quantum mechanics coincide with predictions of large ensembles of particles in
the RI.


title:
The Mid-Infrared Spectral Energy Distribution, Surface Brightness and
  Color Profiles in Elliptical Galaxies

abstract:
  We describe photometry at mid-infrared passbands (1.2 - 24 microns) for a
sample of 18 elliptical galaxies. All surface brightness distributions resemble
de Vaucouleurs profiles, indicating that most of the emission arises from the
photospheres or circumstellar regions of red giant stars. The spectral energy
distribution peaks near 1.6 microns, but the half-light or effective radius has
a pronounced minimum near the K band (2.15 microns). Apart from the 24 micron
passband, all sample-averaged radial color profiles have measurable slopes
within about twice the (K band) effective radius. Evidently this variation
arises because of an increase in stellar metallicity toward the galactic cores.
For example, the sampled-averaged color profile (K - 5.8 microns) has a
positive slope although no obvious absorption feature is observed in spectra of
elliptical galaxies near 5.8 microns. This, and the minimum in the effective
radius, suggests that the K band may be anomalously luminous in metal-rich
stars in galaxy cores. Unusual radial color profiles involving the 24 micron
passband may suggest that some 24 micron emission comes from interstellar not
circumstellar dust grains.


title:
A Proposal for a Cryogenic Experiment to Measure the Neutron Electric
  Dipole Moment (nEDM)

abstract:
  This document is a copy of the original 2003 proposal for the construction
grant for the CryoEDM Experiment at ILL, Grenoble. It is here made publicly
available as a technical reference source for interested parties. It does not
necessarily represent the final configuration of the experiment. Items
pertaining to costs, personnel etc. have been removed.


title: A Universal Property of the Groups Spin^c and Mp^c

abstract:
  It is well known that spinors on oriented Riemannian manifolds cannot be
defined as sections of a vector bundle associated with the frame bundle. For
this reason spin and spin^c structures are often introduced. In this paper we
prove that spin^c structures have a universal property among all other
structures that enable the construction of spinor bundles. We proceed to prove
a similar result for metaplectic^c structures on symplectic manifolds.


title: Singular manifolds, topology change and the dynamics of compactification

abstract:
  We investigate the dynamics of the geometric transitions associated to
compactified spacetimes. By including the dynamics of gravity we are able to
follow the evolution of collapsing cycles as they attempt to undergo a topology
changing transition. Rather than achieving this singular geometry we find that
one of two scenarios occur, depending on the initial conditions. Either a
horizon forms, shielding a curvature singularity, or the cycle re-expands after
an initial contraction phase. For the case where a horizon forms we identify
the final state with a known analytic black-hole solution. We also show use our
results to demonstate a novel compactification mechanism, owing to the
asymptotic structure of this black-hole solution.


title: $\Delta L=2$ hyperon semileptonic decays

abstract:
  We compute the rates of semileptonic B_A \to B_Bl^-l^- (l=e or \mu) hyperon
transitions in a model where intermediate states involve loops of baryons and a
Majorana neutrino. These rates turn out to be well below present experimental
bounds and other theoretical estimates. From the experimental upper limit on
the \Xi^- \to p\mu^-\mu^- decay, we derive the bound <m_{\mu \mu}> < 22 TeV for
the effective Majorana mass of the muon neutrino. Also, an estimate of
background contributions for these decays due to the allowed B_A \to
B_Bl^-l^-\bar{\nu}\bar{\nu} decays are provided.


title: Morphological Studies of the PWN Candidate HESS J1809-193

abstract:
  The source HESS J1809-193 was discovered in 2006 in data of the Galactic
Plane survey, followed by several re-observations. It shows a hard gamma-ray
spectrum and the emission is clearly extended. Its vicinity to PSR J1809-1917,
a high spin-down luminosity pulsar powerful enough to drive the observed
gamma-ray emission, makes it a plausible candidate for a TeV Pulsar Wind Nebula
(PWN). On the other hand, in this region of the sky a number of faint,
radio-emitting supernova remnants can be found, making a firm conclusion on the
source type difficult.
  Here we present a detailed morphological study of recent H.E.S.S. data and
compare the result with X-ray measurements taken with Chandra and radio data.
The association with a PWN is likely, but contributions from supernova remnants
cannot be ruled out.


title:
Toward explaining black hole entropy quantization in loop quantum
  gravity

abstract:
  In a remarkable numerical analysis of the spectrum of states for a
spherically symmetric black hole in loop quantum gravity, Corichi, Diaz-Polo
and Fernandez-Borja found that the entropy of the black hole horizon increases
in what resembles discrete steps as a function of area. In the present article
we reformulate the combinatorial problem of counting horizon states in terms of
paths through a certain space. This formulation sheds some light on the origins
of this step-like behavior of the entropy. In particular, using a few extra
assumptions we arrive at a formula that reproduces the observed step-length to
a few tenths of a percent accuracy. However, in our reformulation the
periodicity ultimately arises as a property of some complicated process, the
properties of which, in turn, depend on the properties of the area spectrum in
loop quantum gravity in a rather opaque way. Thus, in some sense, a deep
explanation of the observed periodicity is still lacking.


title:
A new weak approximation scheme of stochastic differential equations and
  the Runge-Kutta method

abstract:
  In this paper, authors successfully construct a new algorithm for the new
higher order scheme of weak approximation of SDEs. The algorithm presented here
is based on [1][2]. Although this algorithm shares some features with the
algorithm presented by [3], algorithms themselves are completely different and
the diversity is not trivial. They apply this new algorithm to the problem of
pricing Asian options under the Heston stochastic volatility model and obtain
encouraging results.
  [1] Shigeo Kusuoka, "Approximation of Expectation of Diffusion Process and
Mathematical Finance," Advanced Studies in Pure Mathematics, Proceedings of
Final Taniguchi Symposium, Nara 1998 (T. Sunada, ed.), vol. 31 2001, pp.
147--165. [2] Terry Lyons and Nicolas Victoir, "Cubature on Wiener Space,"
Proceedings of the Royal Society of London. Series A. Mathematical and Physical
Sciences 460 (2004), pp. 169--198. [3] Syoiti Ninomiya, Nicolas Victoir, "Weak
approximation of stochastic differential equations and application to
derivative pricing," Applied Mathematical Finance, Volume 15, Issue 2 April
2008, pages 107--121


title: Generalized second law in modified theory of gravity

abstract:
  In the context of modified theory of gravity (f(R) gravity) we try to study
the conditions required for validity of the generalized second law.


title: A Note on Singular Cardinals in Set Theory Without Choice

abstract:
  We discuss how singular can cardinals be in absence of the axiom of choice.
We show that, contrasting with known negative consistency results (of Gitik and
others), certain positive results are provable. Then we pose some problems.


title: On Cauchy surfaces in conformally stationary spacetimes

abstract:
  This paper has been withdrawn by the authors because it has been merged with
paper arXiv:0903.3501v1 [math.DG]


title: KAON 2007: Conference Summary

abstract:
  A concise overview of the interesting recent developments in kaon phyiscs
discussed at KAON 2007 is presented.


title: Soft-photon corrections in multi-body meson decays

abstract:
  The effects due to soft-photon emission (and the related virtual corrections)
in multi-body decays of B, D, and K mesons are analysed. We present analytic
expressions for the universal O(alpha) correction factors which can be applied
to all multi-body decay modes where a tight soft-photon energy cut in the
decaying-particle rest-frame is applied. All-order resummations valid in the
limit of small and large velocities of the final-state particles are also
discussed. The phenomenological implications of these correction factors in the
distortion of Dalitz-plot distributions of K -> 3 pi decays are briefly
analysed.


title:
Time-Dependent Multi-Centre Solutions from New Metrics with Holonomy
  Sim(n-2)

abstract:
  The classifications of holonomy groups in Lorentzian and in Euclidean
signature are quite different. A group of interest in Lorentzian signature in n
dimensions is the maximal proper subgroup of the Lorentz group, SIM(n-2).
Ricci-flat metrics with SIM(2) holonomy were constructed by Kerr and Goldberg,
and a single four-dimensional example with a non-zero cosmological constant was
exhibited by Ghanam and Thompson. Here we reduce the problem of finding the
general $n$-dimensional Einstein metric of SIM(n-2) holonomy, with and without
a cosmological constant, to solving a set linear generalised Laplace and
Poisson equations on an (n-2)-dimensional Einstein base manifold. Explicit
examples may be constructed in terms of generalised harmonic functions. A
dimensional reduction of these multi-centre solutions gives new time-dependent
Kaluza-Klein black holes and monopoles, including time-dependent black holes in
a cosmological background whose spatial sections have non-vanishing curvature.


title: A characterization of Weingarten surfaces in hyperbolic 3-space

abstract:
  We study 2-dimensional submanifolds of the space
${\mathbb{L}}({\mathbb{H}}^3)$ of oriented geodesics of hyperbolic 3-space,
endowed with the canonical neutral K\"ahler structure. Such a surface is
Lagrangian iff there exists a surface in ${\mathbb{H}}^3$ orthogonal to the
geodesics of $\Sigma$.
  We prove that the induced metric on a Lagrangian surface in
${\mathbb{L}}({\mathbb{H}}^3)$ has zero Gauss curvature iff the orthogonal
surfaces in ${\mathbb{H}}^3$ are Weingarten: the eigenvalues of the second
fundamental form are functionally related. We then classify the totally null
surfaces in ${\mathbb{L}}({\mathbb{H}}^3)$ and recover the well-known
holomorphic constructions of flat and CMC 1 surfaces in ${\mathbb{H}}^3$.


title: Complete intersection dimensions and Foxby classes

abstract:
  Let $R$ be a local ring and $M$ a finitely generated $R$-module. The complete
intersection dimension of $M$--defined by Avramov, Gasharov and Peeva, and
denoted $\cidim_R(M)$--is a homological invariant whose finiteness implies that
$M$ is similar to a module over a complete intersection. It is related to the
classical projective dimension and to Auslander and Bridger's Gorenstein
dimension by the inequalities $\gdim_R(N)\leq\cidim_R(N)\leq\pd_R(N)$.
  Using Blanco and Majadas' version of complete intersection dimension for
local ring homomorphisms, we prove the following generalization of a theorem of
Avramov and Foxby: Given local ring homomorphisms $\phi\colon R\to S$ and
$\psi\colon S\to T$ such that $\phi$ has finite Gorenstein dimension, if $\psi$
has finite complete intersection dimension, then the composition
$\psi\circ\phi$ has finite Gorenstein dimension. This follows from our result
stating that, if $M$ has finite complete intersection dimension, then $M$ is
$C$-reflexive and is in the Auslander class $\catac(R)$ for each semidualizing
$R$-complex $C$.


title: Fractional Dynamical Systems on Fractional Leibniz Algebroids

abstract:
  The theory of derivative of noninteger order goes back to Leibniz, Liouville
and Riemann. Derivatives of fractional order have found many applications in
recent studies in mechanics, physics, economics. In this paper we define the
fractional tangent bundle on a manifold, using a method of Radu Miron. The
fractional Leibniz algebroids are investigated. The associated objects have an
geometric character. Some fractional dynamical systems on a fractional Leibniz
algebroid are disscussed.


title: Unitary and Euclidean representations of a quiver

abstract:
  A unitary (Euclidean) representation of a quiver is given by assigning to
each vertex a unitary (Euclidean) vector space and to each arrow a linear
mapping of the corresponding vector spaces. We recall an algorithm for reducing
the matrices of a unitary representation to canonical form, give a certain
description of the representations in canonical form, and reduce the problem of
classifying Euclidean representations to the problem of classifying unitary
representations. We also describe the set of dimensions of all indecomposable
unitary (Euclidean) representations of a quiver and establish the number of
parameters in an indecomposable unitary representation of a given dimension.


title: A Simple Characterization of Strategic Behaviors in Broadcast Channels

abstract:
  In this paper, we consider the problem of resource allocation among two
competing users sharing a binary symmetric broadcast channel. We model the
interaction between autonomous selfish users in the resource allocation and
analyze their strategic behavior in manipulating the allocation outcome. We
analytically show that users will improve their performance (i.e. gain higher
allocated rates) if they have more information about the strategy of the
competing user.


title: Learning for Dynamic Bidding in Cognitive Radio Resources

abstract:
  In this paper, we model the various wireless users in a cognitive radio
network as a collection of selfish, autonomous agents that strategically
interact in order to acquire the dynamically available spectrum opportunities.
Our main focus is on developing solutions for wireless users to successfully
compete with each other for the limited and time-varying spectrum
opportunities, given the experienced dynamics in the wireless network. We
categorize these dynamics into two types: one is the disturbance due to the
environment (e.g. wireless channel conditions, source traffic characteristics,
etc.) and the other is the impact caused by competing users. To analyze the
interactions among users given the environment disturbance, we propose a
general stochastic framework for modeling how the competition among users for
spectrum opportunities evolves over time. At each stage of the dynamic resource
allocation, a central spectrum moderator auctions the available resources and
the users strategically bid for the required resources. The joint bid actions
affect the resource allocation and hence, the rewards and future strategies of
all users. Based on the observed resource allocation and corresponding rewards
from previous allocations, we propose a best response learning algorithm that
can be deployed by wireless users to improve their bidding policy at each
stage. The simulation results show that by deploying the proposed best response
learning algorithm, the wireless users can significantly improve their own
performance in terms of both the packet loss rate and the incurred cost for the
used resources.


title: Testing Lorentz Symmetry with Gravity

abstract:
  In this talk, results from the gravitational sector of the Standard-Model
Extension (SME) are discussed. The weak-field phenomenology of the resulting
modified gravitational field equations is explored. The application of the
results to a variety of modern gravity experiments, including lunar laser
ranging, Gravity Probe B, binary pulsars, and Earth-laboratory tests, shows
promising sensitivity to gravitational coefficients for Lorentz violation in
the SME.


title: Symmetric symplectic homotopy K3 surfaces

abstract:
  A study on the relation between the smooth structure of a symplectic homotopy
K3 surface and its symplectic symmetries is initiated. A measurement of
exoticness of a symplectic homotopy K3 surface is introduced, and the influence
of an effective action of a K3 group via symplectic symmetries is investigated.
It is shown that an effective action by various maximal symplectic K3 groups
forces the corresponding homotopy K3 surface to be minimally exotic with
respect to our measure. (However, the standard K3 is the only known example of
such minimally exotic homotopy K3 surfaces.) The possible structure of a finite
group of symplectic symmetries of a minimally exotic homotopy K3 surface is
determined and future research directions are indicated.


title: Some classes of rational functions and related Banach spaces

abstract:
  For positive integers d, r, and M, we consider the class of rational
functions on real d-dimensional space whose denominators are products of at
most r functions of the form 1+Q(x) where each Q is a quadratic form with
eigenvalues bounded above by M and below by 1/M. Each numerator is a monic
monomial of the same degree as the corresponding denominator. Then we form the
Banach space of countable linear combinations of such rational functions with
absolutely summable coefficients, normed by the infimum of sums of absolute
values of the coefficients. We show that for rational functions whose
denominators are rth powers of a specific 1+Q, or differences of two such
rational functions with the same numerator, the norm is achieved by and only by
the obvious combination of one or two functions respectively. We also find
bounds for coefficients in partial-fraction decompositions of some specific
rational functions, which in some cases are quite sharp.


title: Numerical methods comparison for protostellar collapse calculations

abstract:
  The development of parallel supercomputers allows today the detailed study of
the collapse and the fragmentation of prestellar cores with increasingly
accurate numerical simulations. Thanks to the advances in sub-millimeter
observations, a wide range of observed initial conditions enable us to study
the different modes of low-mass star formation. The challenge for the
simulations is to reproduce the observational results. Two main numerical
methods, namely AMR and SPH, are widely used to simulate the collapse and the
fragmentation of prestellar cores. We compare here thoroughly these two methods
with numerical resolution requirements deduced from previous studies. Our
physical model is as simple as possible, and consists of an isothermal sphere
rotating around the z-axis. We first study the conservation of angular momentum
as a function of the resolution. Then, we explore a wide range of simulation
parameters to study the fragmentation of prestellar cores. There seems to be a
convergence between the two methods, provided resolution in each case is
sufficient. Resolution criteria adapted to our physical cases, in terms of
resolution per Jeans mass, for an accurate description of the formation of
protostellar cores are deduced from the present study. This convergence is
encouraging for future work in simulations of low-mass star formation,
providing the aforementioned criteria are fulfilled.


title: Cooling, Gravity and Geometry: Flow-driven Massive Core Formation

abstract:
  We study numerically the formation of molecular clouds in large-scale
colliding flows including self-gravity. The models emphasize the competition
between the effects of gravity on global and local scales in an isolated cloud.
Global gravity builds up large-scale filaments, while local gravity --
triggered by a combination of strong thermal and dynamical instabilities --
causes cores to form. The dynamical instabilities give rise to a local focusing
of the colliding flows, facilitating the rapid formation of massive
protostellar cores of a few 100 M$_\odot$. The forming clouds do not reach an
equilibrium state, though the motions within the clouds appear comparable to
``virial''. The self-similar core mass distributions derived from models with
and without self-gravity indicate that the core mass distribution is set very
early on during the cloud formation process, predominantly by a combination of
thermal and dynamical instabilities rather than by self-gravity.


title: Besov Spaces and Frames on Compact Manifolds

abstract:
  We show that one can characterize the Besov spaces on a smooth compact
oriented Riemannian manifold, for the full range of indices, through a
knowledge of the size of frame coefficients, using the frames we have
constructed in [8].


title:
About Superluminal motions and Special Relativity: A Discussion of some
  recent Experiments, and the solution of the Causal Paradoxes

abstract:
  Some experiments, performed at Berkeley, Cologne, Florence, Vienna, Orsay,
Rennes, etc., led to the claim that something seems to travel with a group
velocity larger than the speed c of light in vacuum. Various other experimental
results seem to point in the same direction: For instance, localized wavelet-
type solutions to Maxwell equations have been found, both theoretically and
experimentally, that travel with superluminal speed. [Even muonic and
electronic neutrinos [it has been proposed] might be "tachyons", since their
square mass appears to be negative]. With regard to the first-mentioned
experiments, it was recently claimed by Guenter Nimtz that those results with
evanescent waves (or tunneling photons) imply superluminal signal and impulse
transmission, and therefore violate Einstein causality. In this note we want to
stress that, on the contrary, all such results do not place relativistic
causality in jeopardy, even if they referred to actual tachyonic motions: In
fact, Special Relativity can cope even with superluminal objects and waves. For
instance, it is possible (at least in microphysics) to solve also the known
causal paradoxes, devised for faster than light motion, although this is not
widely recognized yet. Here we show, in detail and rigorously, how to solve the
oldest causal paradox, originally proposed by Tolman, which is the kernel of
many further tachyon paradoxes (like J.Bell's, F.A.E.Pirani's, J.D.Edmonds' and
others'). The key to the solution is a careful application of tachyon
mechanics, as it unambiguously follows from special relativity. At Last, in one
of the two Appendices, we propose how to evaluate the group-velocity in the
case of evanescent waves. [PACS nos.: 03.30.+p; 03.50.De; 41.20.Jb; 73.40.Gk;
84.40.Az; 42.82.Et ]


title:
Gravitational Fugacity as the seed of self-organized violent relaxaton
  process toward Local Virial relation

abstract:
  We propose the self-organized relaxation process which drives a collisionless
self-gravitating system (SGS) to the equilibrium state satisfying local virial
(LV) relation. During the violent relaxation process, particles can move widely
within the time interval as short as a few free fall times, because of the
effective potential oscillations. Since such particle movement causes further
potential oscillations, it is expected that the system approaches the critical
state where such particle activities, which we call gravitational fugacity, is
independent of the local position as much as possible. Here we demonstrate that
gravitational fugacity can be described as the functional of the LV ratio,
which means that the LV ratio is a key ingredient estimating the particle
activities against gravitational potential. We also demonstrate that LV
relation is attained if the LV ratio exceeds the crticaial value $b=1$
everywhere in the bound region during the violent relaxation process. The local
region which does not meet this criterion can be trapped into the pre-saturated
state. However, small phase-space perturbation can bring the inactive part into
the LV critical state.


title:
Existence of a multiplicative basis for a finitely spaced module over an
  aggregate

abstract:
  By [R. Bautista, P. Gabriel, A.V Roiter., L. Salmeron, Representation-finite
algebras and multiplicative basis. Invent. Math. 81 (1985) 217-285.], a
finite-dimensional algebra having finitely many isoclasses of indecomposable
representations admits a multiplicative basis. In Sections 4.10-4.12 of [P.
Gabriel, A. V. Roiter, Representations of finite-dimensional algebras.
Encyclopaedia of Math. Sci., vol. 73, Algebra 8, Springer-Verlag, 1992] an
analogous hypothesis was formulated for finitely spaced modules over an
aggregate. We prove this conjecture.


title: Holographic Cosmological Constant and Dark Energy

abstract:
  A general holographic relation between UV and IR cutoff of an effective field
theory is proposed. Taking the IR cutoff relevant to the dark energy as the
Hubble scale, we find that the cosmological constant is highly suppressed by a
numerical factor and the fine tuning problem seems alleviative. We also use
different IR cutoffs to study the case in which the universe is composed of
matter and dark energy.


title:
Global analysis of hadron-production data in e^+ e^- annihilation for
  determining fragmentation functions

abstract:
  Fragmentation functions of pion, kaon, and nucleon are determined by global
analyses of hadron-production data in $e^+e^-$ annihilation. It is particularly
important that uncertainties of the fragmentation functions are estimated for
the first time. We found that light-quark and gluon fragmentation functions
have large uncertainties, so that one should be careful in using these
functions for hadron-production processes in heavy-ion collisions and lepton
scattering. The analysis is extended to possible exotic hadron search by
fragmentation functions. We found that internal structure of $f_0 (980)$, such
as $s\bar s$ or tetraquark configuration, can be determined by noting
differences between favored and disfavored fragmentation functions.


title: Positivity criteria generalizing the leading principal minors criterion

abstract:
  For each Hermitian matrix, we prove that instead of the leading principal
minors some of their sums can be used in the leading principal minors criterion
and in other inertia problems.


title:
Quantum theory of the low-frequency linear susceptibility of
  interferometer-type superconducting qubits

abstract:
  We use the density matrix formalism to analyze the interaction of
interferometer-type superconducting qubits with a high quality tank circuit,
which frequency is well below the gap frequency of a qubit. We start with the
ground state characterization of the superconducting flux and charge qubits.
Then, by making use of a dressed state approach we describe the qubits'
spectroscopy when the qubit is irradiated by a microwave field which is tuned
to the gap frequency. The last section of the paper is devoted to continuous
monitoring of qubit states by using a DC SQUID in the inductive mode.


title:
The problems of classifying pairs of forms and local algebras with zero
  cube radical are wild

abstract:
  We prove that over an algebraically closed field of characteristic not two
the problems of classifying pairs of sesquilinear forms in which the second is
Hermitian, pairs of bilinear forms in which the second is symmetric
(skew-symmetric), and local algebras with zero cube radical and square radical
of dimension 2 are hopeless since each of them reduces to the problem of
classifying pairs of n-by-n matrices up to simultaneous similarity.


title: A Logic of Injectivity

abstract:
  Injectivity of objects with respect to a set $\ch$ of morphisms is an
important concept of algebra, model theory and homotopy theory. Here we study
the logic of injectivity consequences of $\ch$, by which we understand
morphisms $h$ such that injectivity with respect to $\ch$ implies injectivity
with respect to $h$. We formulate three simple deduction rules for the
injectivity logic and for its finitary version where \mor s between finitely
ranked objects are considered only, and prove that they are sound in all
categories, and complete in all "reasonable" categories.


title:
Plasma mechanisms of resonant terahertz detection in two-dimensional
  electron channel with split gates

abstract:
  We analyze the operation of a resonant detector of terahertz (THz) radiation
based on a two-dimensional electron gas (2DEG) channel with split gates. The
side gates are used for the excitation of plasma oscillations by incoming THz
radiation and control of the resonant plasma frequencies. The central gate
provides the potential barrier separating the source and drain portions of the
2DEG channel. Two possible mechanisms of the detection are considered: (1)
modulation of the ac potential drop across the barrier and (2) heating of the
2DEG due to the resonant plasma-assisted absorption of THz radiation followed
by an increase in thermionic dc current through the barrier. Using the device
model we calculate the frequency and temperature dependences of the detector
responsivity associated with both dynamic and heating (bolometric) mechanisms.
It is shown that the dynamic mechanisms dominates at elevated temperatures,
whereas the heating mechanism provides larger contribution at low temperatures,
T=35-40 K.


title:
Problems of classifying associative or Lie algebras and triples of
  symmetric or skew-symmetric matrices are wild

abstract:
  We prove that the problems of classifying triples of symmetric or
skew-symmetric matrices up to congruence, local commutative associative
algebras with zero cube radical and square radical of dimension 3, and Lie
algebras with central commutator subalgebra of dimension 3 are hopeless since
each of them reduces to the problem of classifying pairs of n-by-n matrices up
to simultaneous similarity.


title:
An ultrametric version of the Maillet-Malgrange theorem for nonlinear
  q-difference equations

abstract:
  We prove an ultrametric q-difference version of the Maillet-Malgrange
theorem, on the Gevrey nature of formal solutions of nonlinear analytic
q-difference equations. Since \deg_q and \ord_q define two valuations on
{\mathbb C}(q), we obtain, in particular, a result on the growth of the degree
in q and the order at q of formal solutions of nonlinear q-difference
equations, when q is a parameter. We illustrate the main theorem by considering
two examples: a q-deformation of ``Painleve' II'', for the nonlinear situation,
and a q-difference equation satisfied by the colored Jones polynomials of the
figure 8 knots, in the linear case.
  We consider also a q-analog of the Maillet-Malgrange theorem, both in the
complex and in the ultrametric setting, under the assumption that |q|=1 and a
classical diophantine condition.


title: Biquandle longitude invariant of long virtual knots

abstract:
  It is known that the number of biquandle colorings of a long virtual knot
diagram, with a fixed color of the initial arc, is a knot invariant. In this
paper we describe a more subtle invariant: a family of biquandle endomorphisms
obtained from the set of colorings and longitudinal information.


title: Littlewood's algorithm and quaternion matrices

abstract:
  A strengthened form of Schur's triangularization theorem is given for
quaternion matrices with real spectrum (for complex matrices it was given by
Littlewood). Littlewood's algorithm for reducing a complex matrix to a
canonical form under unitary similarity is extended to quaternion matrices
whose eigenvalues have geometric multiplicity 1.


title:
Resonant Excitation of Disk Oscillations in Deformed Disks II: A Model
  of High Frequency QPOs

abstract:
  The amplification of disk oscillations resulting from nonlinear resonant
couplings between the oscillations and a disk deformation is examined. The disk
is geometrically thin and general relativistic with a non-rotating central
source. A Lagrangian formulation is adopted. The author examined the same
problem a few years ago, but here we derive a general stability criterion in a
more perspective way. Another distinct point from the previous work is that in
addition to the case where the deformation is a warp, the case where the
deformation is a one-armed pattern symmetric with respect to the equatorial
plane is considered. The results obtained show that in addition to the previous
results that the inertial-acoustic mode and g-mode oscillations are amplified
by horizontal resonance in warped disks, they also amplified by horizontal
resonance in disks deformed by one-armed pattern symmetric with respect to the
equatorial plane. If we consider local oscillations that are localized around
boundaries of their propagation region, the resonance occurs at $4r_{\rm g}$,
where $r_{\rm g}$ is the Schwarzschild radius. If nonlocal oscillations are
considered, frequency ranges of oscillations where oscillations are resonantly
amplified are specified.


title: Adjoint cohomology of graded Lie algebras of maximal class

abstract:
  We compute explicitly the adjoint cohomology of two N-graded Lie algebras of
maximal class (infinite dimensional filiform Lie algebras) m_0 and m_2. It is
known that up to an isomorphism there are only three N-graded Lie algebras of
the maximal class. The third algebra from this list is the "positive" part L_1
of the Witt (or Virasoro) algebra and its adjoint cohomology was computed
earlier by Feigin and Fukhs. We show that the total space H*(m_j,m_j) is
"almost" isomorphic to the completed tensor product of the algebra m_j by
scalar cohomology space H^*(m_j), j=0,2.


title:
Estimate of the number of one-parameter families of modules over a tame
  algebra

abstract:
  The problem of classifying modules over a tame algebra A reduces to a block
matrix problem of tame type whose indecomposable canonical matrices are zero-
or one-parameter. Respectively, the set of nonisomorphic indecomposable modules
of dimension at most d divides into a finite number f(d,A) of modules and
one-parameter series of modules.
  We prove that the number of m-by-n canonical parametric block matrices with a
given partition into blocks is bounded by 4^s, where s is the number of free
entries (which is at most mn), and estimate the number f(d,A).


title:
Computation of the canonical form for the matrices of chains and cycles
  of linear mappings

abstract:
  Paul Van Dooren [Linear Algebra Appl. 27 (1979) 103-140] constructed an
algorithm for the computation of all irregular summands in Kronecker's
canonical form of a matrix pencil. The algorithm is numerically stable since it
uses only unitary transformations. We extend Paul Van Dooren's algorithm to the
matrices of a cycle of linear mappings.


title: Q-Curvature, Spectral Invariants, and Representation Theory

abstract:
  We give an introductory account of functional determinants of elliptic
operators on manifolds and Polyakov-type formulas for their infinitesimal and
finite conformal variations. We relate this to extremal problems and to the
Q-curvature on even-dimensional conformal manifolds. The exposition is
self-contained, in the sense of giving references sufficient to allow the
reader to work through all details.


title: Formation of molecular hydrogen on amorphous silicate surfaces

abstract:
  Experimental results on the formation of molecular hydrogen on amorphous
silicate surfaces are presented and analyzed using a rate equation model. The
energy barriers for the relevant diffusion and desorption processes are
obtained. They turn out to be significantly higher than those obtained for
polycrystalline silicates, demonstrating the importance of grain morphology.
Using these barriers we evaluate the efficiency of molecular hydrogen formation
on amorphous silicate grains under interstellar conditions. It is found that
unlike polycrystalline silicates, amorphous silicate grains are efficient
catalysts of H_2 formation in diffuse interstellar clouds.


title: Canonical forms for complex matrix congruence and *congruence

abstract:
  Canonical forms for congruence and *congruence of square complex matrices
were given by Horn and Sergeichuk in [Linear Algebra Appl. 389 (2004) 347-353],
based on Sergeichuk's paper [Math. USSR, Izvestiya 31 (3) (1988) 481-501],
which employed the theory of representations of quivers with involution. We use
standard methods of matrix analysis to prove directly that these forms are
canonical. Our proof provides explicit algorithms to compute all the blocks and
parameters in the canonical forms. We use these forms to derive canonical pairs
for simultaneous congruence of pairs of complex symmetric and skew-symmetric
matrices as well as canonical forms for simultaneous *congruence of pairs of
complex Hermitian matrices.


title: The Camera of the MAGIC-II Telescope

abstract:
  The MAGIC 17m diameter Cherenkov telescope will be upgraded with a second
telescope within the year 2007. The camera of MAGIC-II will include several new
features compared to the MAGIC-I camera. Photomultipliers with the highest
available photon collection efficiency have been selected. A modular design
allows easier access and flexibility to test new photodetector technologies.
The camera will be uniformly equipped with 0.1 degree diamter pixels, which
allows the use of an increased trigger area. Finally, the overall signal chain
features a large bandwidth to retain the shape of the very fast Cherenkov
signals.


title: Sparse Representations for Structured Noise Filtering

abstract:
  The role of sparse representations in the context of structured noise
filtering is discussed. A strategy, especially conceived so as to address
problems of an ill posed nature, is presented. The proposed approach revises
and extends the Oblique Matching Pursuit technique. It is shown that, by
working with an orthogonal projection of the signal to be filtered, it is
possible to apply orthogonal matching pursuit like strategies in order to
accomplish the required signal discrimination


title: Cross Comparison of Synonym Graphs in A Multi Linguistic Context

abstract:
  Language is one of the most important aspects of human cognition; it
represents the way we think, act and communicate with each other. Each language
has its own history, background, and form. A language represents a lot of
important cultural aspects of the nation speaking it. Languages differ and so
do cultures. In this paper we analyze cultural differences between East and
West in a multi-linguistic context from a complex networks point of view. There
has been considerable work on the topic of cultural differences by psychologist
and sociologist. Also studies on complex networks that make use of WordNet have
been done, but until now there is no previous work that uses WordNets from
different Eastern and Western languages as complex lexical networks in order to
obtain possible differences or similarities between the cultures using those
respective languages. Our work aims to do this.


title:
Source radii at target rapidity from two-proton and two-deuteron
  correlations in central Pb+Pb collisions at 158 A GeV

abstract:
  Two-proton and two-deuteron correlations have been studied in the target
fragmentation region of central Pb+Pb collisions at 158 A GeV. Protons and
deuterons were measured with the Plastic Ball spectrometer of the WA98
experiment at the CERN SPS. The results of one-dimensional and
multi-dimensional analyses using both the Bertsch-Pratt and
Yano-Koonin-Podgoretsky parameterizations of the two-particle correlation
functions are presented. The proton source exhibits a volume emission, while
the deuteron source, with small outward radius, appears opaque. Both proton and
deuteron sources have cross-terms R_{ol}^2 and longitudinal velocities beta
consistent with zero, indicating a boost-invariant expansion. The invariant
radius parameter R follows an approximate A/sqrt{m} scaling while the
longitudinal and transverse radii,
  R_{L} and R_{T}, scale approximately as A/sqrt{m_{T}} with A ~ 3 fm GeV^{1/2}
in both cases.


title: Unparticle physics in diphoton production at the CERN LHC

abstract:
  We have considered the di-photon production with unparticle at LHC. The
contributions of spin-0 and spin-2 unparticle to the di-photon production are
studied in the invariant mass and other kinematical distributions, along with
their dependencies on the model dependent parameters. The signal corresponding
to the unparticle is significant for moderate coupling constant values.


title: Electron/Photon identification in ATLAS and CMS

abstract:
  Recent studies in ATLAS and CMS experiments for the reconstruction and
identification of electrons and photons using full Monte Carlo and testbeam
data are reported


title:
Aharonov-Bohm differential conductance modulation in defective metallic
  single-wall carbon nanotubes

abstract:
  Using a perturbative approach, the effects of the energy gap induced by the
Aharonov-Bohm (AB) flux on the transport properties of defective metallic
single-walled carbon nanotubes (MSWCNTs) are investigated. The electronic waves
scattered back and forth by a pair of impurities give rise to Fabry-Perot
oscillations which constitutes a coherent backscattering interference pattern
(CBSIP). It is shown that, the CBSIP is aperiodically modulated by applying a
magnetic field parallel to the nanotube axis. In fact, the AB-flux brings this
CBSIP under control by an additional phase shift. As a consequence, the extrema
as well as zeros of the CBSIP are located at the irrational fractions of the
quantity $\Phi_\rho={\Phi}/{\Phi_0}$, where $\Phi$ is the flux piercing the
nanotube cross section and $\Phi_{0}=h/e$ is the magnetic quantum flux. Indeed,
the spacing between two adjacent extrema in the magneto-differential
conductance (MDC) profile is decreased with increasing the magnetic field. The
faster and higher and slower and shorter variations is then obtained by
metallic zigzag and armchair nanotubes, respectively. Such results propose that
defective metallic nanotubes could be used as magneto-conductance switching
devices based on the AB effect.


title:
Next-nearest-neighbor spin-spin and chiral-spin correlation functions in
  generalized XXX chain

abstract:
  We develop a simple technique for calculation of next to nearest neighbor
spin-spin and chiral-spin correlation functions in inhomogeneous XXX model.
Exact expression of the chiral-spin order parameter as a function of the model
parameter, $\omega$, is analytically found. Using the same method we also
calculate the next to nearest neighbor spin-spin correlation function. In the
limit $\omega -> 0$ it reproduces the known result for the vacuum expectation
value of the next to nearest neighbor spins in the standard Heisenberg spin
chain. The technique is simple and can be extended for calculation of next to
next to nearest neighbor correlation functions as well as for calculation of
correlation functions in XXZ model.


title: Normal form of m-by-n-by-2 matrices for equivalence

abstract:
  We give a canonical form of m-by-2-by-2 spatial matrices for equivalence over
any field.


title: Quantum Thetas on Noncommutative T^d with General Embeddings

abstract:
  In this paper we construct quantum theta functions over noncommutative T^d
with general embeddings. Manin has constructed quantum theta functions from the
lattice embedding into vector space x finite group. We extend Manin's
construction of quantum thetas to the case of general embedding of vector space
x lattice x torus. It turns out that only for the vector space part of the
embedding there exists the holomorphic theta vector, while for the lattice part
there does not. Furthermore, the so-called quantum translations from embedding
into the lattice part become non-additive, while those from the vector space
part are additive.


title:
Effect of Motion of the Reference Frame on Geometrical Form of the Line
  of Monopole Singularity

abstract:
  The monopole singularity string, infinite direct line in the rest reference
frame, is considered as a rigid physical line, and behavior of its geometrical
form under the Lorentz transformations is studied. The method to test the form
of any rigid line or surface in relativistical terms is based on the use of
light signals emitted from the origin of the reference frame. Influence of the
motion of the reference frame on the form of singularity line is as follows:
(1) in general case, when the line does not go through the origin of the rest
reference frame the line in the moving reference frame becomes a hyperbola; (2)
in the special case, when the line of singularity goes through the origin of
the rest reference frame, the line in the moving reference preserves its form
only modified by the relativistical aberration effect.


title: Canonical matrices for linear matrix problems

abstract:
  We consider a large class of matrix problems, which includes the problem of
classifying arbitrary systems of linear mappings. For every matrix problem from
this class, we construct Belitskii's algorithm for reducing a matrix to a
canonical form, which is the generalization of the Jordan normal form, and
study the set C(m,n) of indecomposable canonical m-by-n matrices. Considering
C(m,n) as a subset in the affine space of m-by-n matrices, we prove that either
C(m,n) consists of a finite number of points and straight lines for every
(m,n), or C(m,n) contains a 2-dimensional plane for a certain (m,n).


title: Field equations of electromagnetic and gravitational fields

abstract:
  The paper studies the validity of Maxwell equation in the case for
coexistence of electromagnetic field and gravitational field. With the algebra
of quaternions, the Newton's law of gravitation is the same as that in
classical theory of gravitational field. Meanwhile the Maxwell equation is
identical with that in classical theory of electromagnetic field. And the
related conclusions can be spread to the case for coexistence of
electromagnetic field and gravitational field by the algebra of octonions. The
study claims that Maxwell equation keeps unchanged in the case for coexistence
of gravitational field and electromagnetic field, except for the direction of
displacement current.


title: Exploring the QCD phase structure with density fluctuations

abstract:
  We briefly summarize the properties of conserved charge fluctuations as a
sensitive probe for the QCD phase transitions. We discuss the density
fluctuations which play a significant role to search for the critical end
point. The importance of spinodal instabilities to distinguish the first-order
phase transition is also indicated.


title: Complexity of matrix problems

abstract:
  In representation theory, the problem of classifying pairs of matrices up to
simultaneous similarity is used as a measure of complexity; classification
problems containing it are called wild problems. We show in an explicit form
that this problem contains all classification matrix problems given by quivers
or posets. Then we prove that it does not contain (but is contained in) the
problem of classifying three-valent tensors. Hence, all wild classification
problems given by quivers or posets have the same complexity; moreover, a
solution of any one of these problems implies a solution of each of the others.
The problem of classifying three-valent tensors is more complicated.


title: Congruences of a square matrix and its transpose

abstract:
  It is known that any square matrix over any field F is congruent to its
transpose. We show that they are also *congruent with respect to any
nonidentity involution on F.


title: Semiclassical limit of the scattering cross section as a distribution

abstract:
  We consider quantum scattering from a compactly supported potential $q$. The
semiclassical limit amounts to letting the wavenumber $k \to \infty$ while
rescaling the potential as $k^2 q$ (alternatively, one can scale Planck's
constant $\hbar \searrow 0$). It is well-known that, under appropriate
conditions, for $\om \in \bbS_{n-1}$ such that there is exactly one outgoing
ray with direction $\om$ (in the sense of geometric optics), the differential
scattering cross section $|f(\om,k)|^{2}$ tends to the classical differential
cross section $|f_{cl}(\om)|^2$ as $k \uparrow \infty$. It is also clear that
the same can not be true if there is more than one outgoing ray with direction
$\om$ or for \emph{nonregular} directions (including the forward direction
$\theta_0$). However, based on physical intuition, one could conjecture $|f|^2
\to |f_{cl}|^2 + \sigma_{cl} \delta_{\theta_0}$ where $|f_{cl}|^2$ is the
classical cross section and $\delta_{\theta_0}$ is the Dirac measure supported
at the forward direction $\theta_0$. The aim of this paper is to prove this
conjecture.


title: Supersymmetry Breaking Vacua from M Theory Fivebranes

abstract:
  We consider intersecting brane configurations realizing N=2 supersymmetric
gauge theories broken to N=1 by multitrace superpotentials, and softly to N=0.
We analyze, in the framework of M5-brane wrapping a curve, the supersymmetric
vacua and the analogs of spontaneous supersymmetry breaking and soft
supersymmetry breaking in gauge theories. We show that the M5-brane does not
exhibit the analog of metastable spontaneous supersymmetry breaking, and does
not have non-holomorphic minimal volume curves with holomorphic boundary
conditions. However, we find that any point in the N=2 moduli space can be
rotated to a non-holomorphic minimal volume curve, whose boundary conditions
break supersymmetry. We interpret these as the analogs of soft supersymmetry
breaking vacua in the gauge theory.


title: A Gauge field Induced by the Global Gauge Invariance of Action Integral

abstract:
  As a general rule, it is considered that the global gauge invariance of an
action integral does not cause the occurrence of gauge field. However, in this
paper we demonstrate that when the so-called localized assumption is excluded,
the gauge field will be induced by the global gauge invariance of the action
integral. An example is given to support this conclusion.


title:
Infraparticle Scattering States in Non-Relativistic QED: I. The
  Bloch-Nordsieck Paradigm

abstract:
  We construct infraparticle scattering states for Compton scattering in the
standard model of non-relativistic QED. In our construction, an infrared cutoff
initially introduced to regularize the model is removed completely. We
rigorously establish the properties of infraparticle scattering theory
predicted in the classic work of Bloch and Nordsieck from the 1930's, Faddeev
and Kulish, and others. Our results represent a basic step towards solving the
infrared problem in (non-relativistic) QED.


title: Exact solution of one class of Maryland model

abstract:
  The Hamiltonian H of one-body Maryland model is defined as the sum of a
linear unperturbed Hamiltonian H_0 and the interaction V, which is a Toeplitz
matrix. Maryland model with a doubly infinite Hilbert space are exactly solved.
Special cases of one-body Maryland model include the original Maryland model
(Phys. Rev. Lett. 49, 833 (1982) and Physica 10D, 369 (1984)), which describes
a quantum kickied linear rotator and single band Bloch oscillations. Maryland
model and single band Bloch oscillations are the same Hamiltonian in two
different representations. A special case of many-body Maryland model is
Luttinger model.


title:
Reentrant temperature dependence of critical current in superconductor -
  ferromagnet - superconductor junctions based on PdFe alloys

abstract:
  The magnetic and transport properties of $Pd_{0.99}Fe_{0.01}$ thin films have
been studied. We have found that the Curie temperature of the films is about 20
K and the magnetic properties strongly depend on temperature below $T_{Curie}$.
We have also fabricated the set of superconductor-ferromagnet-superconductor
josephson junctions $Nb-PdFe-Nb$. The temperature dependence of the junctions
with the ferromagnet layer thickness of about 36 nm shows the reentrant
behaviour that is the evidence of the transition of the junction into the
$\pi$-state.


title:
Resolution of singularities, asymptotic expansions of oscillatory
  integrals, and related phenomena

abstract:
  The elementary resolution of singularities algorithm of the author's earlier
paper (math.CA/0609217) is developed further, replacing the quasibump functions
in the blown up coordinates with the characteristic function of a rectangle
times a smooth function. Such functions are easier to deal with, and as
application the existence of asymptotic expansions for oscillatory integrals
and related objects is given an elementary proof. In addition, some more
detailed information about these expansions is given.


title:
Comment on ``Method to analyze electromechanical stability of dielectric
  elastomers" [Appl. Phys. Lett. 91, 061921 (2007)]

abstract:
  The model of Zhao and Suo can be readily generalized to predict the critical
breakdown electric field $E_c$ value of elastomers with arbitrary elastic
strain energy function. An explicit expression for $E_c$ is presented for
elastomeric thin films under biaxial strain and comparisons are made with
experimental data using a two term Ogden rubber elasticity model. Simplified
results for uniaxial and for equi-biaxial stress provide further insight into
the findings of Zhao and Suo.


title: Four-Probe Measurements of Carbon Nanotubes with Narrow Metal Contacts

abstract:
  We find that electrons in single-wall carbon nanotubes may propagate
substantial distances (tens of nanometers) under the metal contacts. We perform
four-probe transport measurements of the nanotube conductance and observe
significant deviations from the standard Kirchhoff's circuit rules. Most
noticeably, injecting current between two neighboring contacts on one end of
the nanotube, induces a non-zero voltage difference between two contacts on the
other end.


title: Our Search for an H-R Diagram of Quasars

abstract:
  The 4D Eigenvector 1 parameter space was introduced seven years ago as an
attempt at multiwavelength spectroscopic representation of quasars. It appears
to be the most effective diagnostic space for unifying the diversity of broad
line AGN. This progress report shows that the diagnostic power of 4DE1 is
confirmed using optical spectra from the SDSS, UV spectra from HST and X-ray
spectra from XMM. Our introduction of the population A-B concept continues to
provide useful insights into quasar diversity. Largely radio-quiet, high
accreting, low BH mass Pop. A sources (FWHM H_beta <= 4000 km/s) show strong
FeII emission, a soft X-ray excess and a CIV profile blueshift. Low accreting
large BH mass Pop. B quasars (FWHM H_beta > 4000 km/s) include most radio-loud
AGN and show weak FeII emission and little evidence for a soft X-ray excess or
a CIV blueshift.


title: The Pierre Auger Observatory: status, results and perspective

abstract:
  While the completion of the Pierre Auger Observatory (or simply ``Auger'') is
still underway, the 5165 km^2.sr.yr integrated acceptance accumulated since the
January 1st, 2004 is now significantly larger than what was gathered by the
previous experiments dedicated to the detection of ultra-high-energy cosmic
rays (UHECRs). We report on the development status of Auger and present some
results related to the cosmic-ray energy spectrum, composition and
anisotropies, and the photon fraction at ultra-high energy. We briefly discuss
the importance of the ankle region to understand the overall phenomenology of
cosmic-rays, and mention future enhancements of Auger focusing on this energy
range.


title: Generalized vorticity in transitional quantum turbulence

abstract:
  Transition to condensate state in the degenerate gas of bosons is studied
using the Gross-Pitaevskii equation. It is shown that adiabatic invariance of
an enstrophy (mean squared vorticity) based on a generalized vorticity $curl
(|\psi|^2 {\bf v})/|\psi|^2$, controls dynamics of the transitional turbulence
just before formation of the condensate with its tangles of quantized vortices
($|\psi|^2 {\bf v}$ is the weighted velocity field defined on the macroscopic
wave function $\psi$). Scaling of the angle-averaged occupation number
spectrum, $N_k \sim k^{-1}$, has been obtained for the free developing
transitional turbulence for the weak nonlinear (and completely disordered)
initial conditions. Results of the three-dimensional numerical simulations have
been used to support the theoretical consideration.


title:
Ultrahigh-energy cosmic-ray bounds on nonbirefringent modified-Maxwell
  theory

abstract:
  A particularly simple Lorentz-violating modification of the Maxwell theory of
photons maintains gauge invariance, CPT, and renormalization. This
modified-Maxwell theory, coupled to standard Dirac particles, involves nineteen
dimensionless "deformation parameters." Ten of these parameters lead to
birefringence and are already tightly constrained by astrophysics. New bounds
on the remaining nine nonbirefringent parameters can be obtained from the
absence of vacuum Cherenkov radiation for ultrahigh-energy cosmic rays
(UHECRs). Using selected UHECR events recorded at the Pierre Auger Observatory
and assigning pseudo-random directions (i.e., assuming large-scale isotropy),
Cherenkov bounds are found at the 10^{-18} level, which improve considerably
upon current laboratory bounds. Future UHECR observations may reduce these
Cherenkov bounds to the 10^{-23} level. An Addendum with two-sided bounds has
been published separately [Phys. Rev. D 77, 117901 (2008), arXiv:0806.4351].


title: Decohering d-dimensional quantum resistance

abstract:
  The Landauer scattering approach to 4-probe resistance is revisited for the
case of a d-dimensional disordered resistor in the presence of decoherence. Our
treatment is based on an invariant-embedding equation for the evolution of the
coherent reflection amplitude coefficient in the length of a 1-dimensional
disordered conductor, where decoherence is introduced at par with the disorder
through an outcoupling, or stochastic absorption, of the wave amplitude into
side (transverse) channels, and its subsequent incoherent re-injection into the
conductor. This is essentially in the spirit of B{\"u}ttiker's
reservoir-induced decoherence. The resulting evolution equation for the
probability density of the 4-probe resistance in the presence of decoherence is
then generalised from the 1-dimensional to the d-dimensional case following an
anisotropic Migdal-Kadanoff-type procedure and analysed. The anisotropy, namely
that the disorder evolves in one arbitrarily chosen direction only, is the main
approximation here that makes the analytical treatment possible. A
qualitatively new result is that arbitrarily small decoherence reduces the
localisation-delocalisation transition to a crossover making resistance moments
of all orders finite.


title: Rigidity, boundary interpolation and reproducing kernels

abstract:
  We use reproducing kernel methods to study various rigidity problems. The
methods and setting allow us to also consider the non-positive case.


title:
Dark Energy-Dark Matter Interaction from the Abell Cluster A586 and
  violation of the Equivalence Principle

abstract:
  We find that the Abell Cluster A586 exhibits evidence of the interaction
between dark matter and dark energy and argue that this interaction suggests
evidence of violation of the Equivalence Principle. This violation is found in
the context of two different models of dark energy-dark matter interaction.


title:
Autoencoder, Principal Component Analysis and Support Vector Regression
  for Data Imputation

abstract:
  Data collection often results in records that have missing values or
variables. This investigation compares 3 different data imputation models and
identifies their merits by using accuracy measures. Autoencoder Neural
Networks, Principal components and Support Vector regression are used for
prediction and combined with a genetic algorithm to then impute missing
variables. The use of PCA improves the overall performance of the autoencoder
network while the use of support vector regression shows promising potential
for future investigation. Accuracies of up to 97.4 % on imputation of some of
the variables were achieved.


title:
Scattering Theory for Jacobi Operators with General Steplike
  Quasi-Periodic Background

abstract:
  We develop direct and inverse scattering theory for Jacobi operators with
steplike coefficients which are asymptotically close to different finite-gap
quasi-periodic coefficients on different sides. We give a complete
characterization of the scattering data, which allow unique solvability of the
inverse scattering problem in the class of perturbations with finite first
moment.


title: Some aspects of calculus on non-smooth sets

abstract:
  Sets in R^n in which every pair of elements x, y can be connected by a path
in the set of length bounded by a constant multiple of the distance between x
and y are considered.


title: Measurement of Rashba and Dresselhaus spin-orbit magnetic fields

abstract:
  Spin-orbit coupling is a manifestation of special relativity. In the
reference frame of a moving electron, electric fields transform into magnetic
fields, which interact with the electron spin and lift the degeneracy of
spin-up and spin-down states. In solid-state systems, the resulting spin-orbit
fields are referred to as Dresselhaus or Rashba fields, depending on whether
the electric fields originate from bulk or structure inversion asymmetry,
respectively. Yet, it remains a challenge to determine the absolute value of
both contributions in a single sample. Here we show that both fields can be
measured by optically monitoring the angular dependence of the electrons' spin
precession on their direction of movement with respect to the crystal lattice.
Furthermore, we demonstrate spin resonance induced by the spin-orbit fields. We
apply our method to GaAs/InGaAs quantum-well electrons, but it can be used
universally to characterise spin-orbit interactions in semiconductors,
facilitating the design of spintronic devices.


title:
The Rise and Fall of Debris Disks: MIPS Observations of h and chi Persei
  and the Evolution of Mid-IR Emission from Planet Formation

abstract:
  We describe Spitzer/MIPS observations of the double cluster, h and $\chi$
Persei, covering a $\sim$ 0.6 square-degree area surrounding the cores of both
clusters. The data are combined with IRAC and 2MASS data to investigate $\sim$
616 sources from 1.25-24 $\mu m$. We use the long-baseline $K_{s}$-[24] color
to identify two populations with IR excess indicative of circumstellar
material: Be stars with 24 $\mu m$ excess from optically-thin free free
emission and 17 fainter sources (J$\sim$ 14-15) with [24] excess consistent
with a circumstellar disk. The frequency of IR excess for the fainter sources
increases from 4.5 $\mu m$ through 24 $\mu m$. The IR excess is likely due to
debris from the planet formation process. The wavelength-dependent behavior is
consistent with an inside-out clearing of circumstellar disks. A comparison of
the 24 $\mu m$ excess population in h and $\chi$ Per sources with results for
other clusters shows that 24 $\mu m$ emission from debris disks 'rises' from 5
to 10 Myr, peaks at $\sim$ 10-15 Myr, and then 'falls' from $\sim$ 15/20 Myr to
1 Gyr.


title: Hamiltonian vector fields of homogeneous polynomials in two variables

abstract:
  Let $g:\mathbb{R}^2\to\mathbb{R}$ be a homogeneous polynomial of degree
$p>1$, $G=(-g'_{y}, g'_{x})$ be its Hamiltonian vector field, and $G_t$ be the
local flow generated by $G$. Denote by $E(G,O)$ the space of germs of
$C^{\infty}$ diffeomorphisms $(\mathbb{R}^2,O)\to(\mathbb{R}^2,O)$ that
preserve orbits of $G$. Let also $E_{\mathrm{id}}(G,O)$ be the identity
component of $E(G,O)$ with respect to $C^1$-topology.
  Suppose that $g$ has no multiple prime factors. Then we prove that for every
$h\in E_{\mathrm{id}}(G,O)$ there exists a germ of a smooth function
$\alpha:\mathbb{R}^2\to\mathbb{R}$ at $O$ such that $h(z)=G_{\alpha(z)}(z)$.


title: Quantifying Homology Classes II: Localization and Stability

abstract:
  In the companion paper, we measured homology classes and computed the optimal
homology basis. This paper addresses two related problems, namely, localization
and stability. We localize a class with the cycle minimizing a certain
objective function. We explore three different objective functions, namely,
volume, diameter and radius. We show that it is NP-hard to compute the smallest
cycle using the former two. We also prove that the measurement defined in the
companion paper is stable with regard to small changes of the geometry of the
concerned space.


title: Extension of the Weil-Petersson connection

abstract:
  Convexity properties of Weil-Petersson geodesics on the Teichm\"{u}ller space
of punctured Riemann surfaces are investigated. A normal form is presented for
the Weil-Petersson Levi-Civita connection for pinched hyperbolic metrics. The
normal form is used to establish approximation of geodesics in boundary spaces.
Considerations are combined to establish convexity along Weil-Petersson
geodesics of the functions the distance between horocycles for a hyperbolic
metric.


title: Time Optimal Attitude Control for a Rigid Body

abstract:
  A time optimal attitude control problem is studied for the dynamics of a
rigid body. The objective is to minimize the time to rotate the rigid body to a
desired attitude and angular velocity while subject to constraints on the
control input. Necessary conditions for optimality are developed directly on
the special orthogonal group using rotation matrices. They completely avoid
singularities associated with local parameterizations such as Euler angles, and
they are expressed as compact vector equations. In addition, a discrete control
method based on a geometric numerical integrator, referred to as a Lie group
variational integrator, is proposed to compute the optimal control input. The
computational approach is geometrically exact and numerically efficient. The
proposed method is demonstrated by a large-angle maneuver for an elliptic
cylinder rigid body.


title: Hanle effect in the CN violet system with LTE modeling

abstract:
  Weak entangled magnetic fields with mixed polarity occupy the main part of
the quiet Sun. The Zeeman effect diagnostics fails to measure such fields
because of cancellation in circular polarization. However, the Hanle effect
diagnostics, accessible through the second solar spectrum, provides us with a
very sensitive tool for studying the distribution of weak magnetic fields on
the Sun. Molecular lines are very strong and even dominate in some regions of
the second solar spectrum. The CN $B {}^{2} \Sigma - X {}^{2} \Sigma$ system is
one of the richest and most promising systems for molecular diagnostics and
well suited for the application of the differential Hanle effect method. The
aim is to interpret observations of the CN $B {}^{2} \Sigma - X {}^{2} \Sigma$
system using the Hanle effect and to obtain an estimation of the magnetic field
strength. We assume that the CN molecular layer is situated above the region
where the continuum radiation is formed and employ the single-scattering
approximation. Together with the Hanle effect theory this provides us with a
model that can diagnose turbulent magnetic fields. We have succeeded in fitting
modeled CN lines in several regions of the second solar spectrum to
observations and obtained a magnetic field strength in the range from 10--30 G
in the upper solar photosphere depending on the considered lines.


title: Calice Si-W EM Calorimeter: Preliminary Results of the Testbeams 2006

abstract:
  The CALICE Si-W electromagnetic calorimeter has been tested with electron
beams (1 to 6 GeV) at DESY in May 2006, as well as electrons (6 to 45 GeV) and
hadrons (6 to 80 GeV) at CERN in August and October 2006. Several millions of
events have been taken at different incident angles and three beam impact
positions. The ECAL calibration is performed with muon beams and shows a good
uniformity for nearly all channels. The large statistics available allows not
only to characterise the ECAL physics performance, but also to identify subtle
hardware effects.


title: Compact Stellar Systems around NGC 1399

abstract:
  We have obtained spectroscopic redshifts of colour-selected point sources in
four wide area VLT-FLAMES fields around the Fornax Cluster giant elliptical
galaxy NGC 1399, identifying as cluster members 30 previously unknown faint
(-10.5<M_g'<-8.8) compact stellar systems (CSS), and improving redshift
accuracy for 23 previously catalogued CSS.
  By amalgamating our results with CSS from previous 2dF observations and
excluding CSS dynamically associated with prominent (non-dwarf) galaxies
surrounding NGC 1399, we have isolated 80 `unbound' systems that are either
part of NGC 1399's globular cluster (GC) system or intracluster GCs. For these
unbound systems, we find (i) they are mostly located off the main stellar locus
in colour-colour space; (ii) their projected distribution about NGC 1399 is
anisotropic, following the Fornax Cluster galaxy distribution, and there is
weak evidence for group rotation about NGC 1399; (iii) their
completeness-adjusted radial surface density profile has a slope similar to
that of NGC 1399's inner GC system; (iv) their mean heliocentric recessional
velocity is between that of NGC 1399's inner GCs and that of the surrounding
dwarf galaxies, but their velocity dispersion is significantly lower; (v)
bright CSS (M_V<-11) are slightly redder than the fainter systems, suggesting
they have higher metallicity; (vi) CSS show no significant trend in $g' - i'$
colour index with radial distance from NGC 1399.


title: Contact Interactions at the LHC

abstract:
  Contact interactions offer a general framework for describing a new
interaction with a scale above the energy scale probed. These interactions can
occur if the Standard Model particles are composite or if new heavy particles
are exchanged. The discovery potential of contact interactions at the LHC in
dimuon and dijet final states at startup and the asymptotic reach are
presented.


title: A photometric search for transients in galaxy clusters

abstract:
  We have begun a program to search for supernovae and other transients in the
fields of galaxy clusters with the 2.3m Bok Telescope on Kitt Peak. We present
our automated photometric methods for data reduction, efficiency
characterization, and initial spectroscopy. With this program, we aim to
ultimately identify $\sim$25-35 cluster SN Ia ($\sim$10 of which will be
intracluster, hostless events) and constrain the SN Ia rate associated with
old, passive stellar populations. With these measurements we will constrain the
relative contribution of hostless and hosted SN Ia to the metal enrichment of
the intracluster medium. In the current work, we have identified a central
excess of transient events within $1.25 r_{200}$ in our cluster fields after
statistically subtracting out the 'background' transient rate taken from an
off-cluster CCD chip. Based on the published rate of SN Ia for cluster
populations we estimate that $\sim$20 percent of the excess cluster transients
are due to cluster SN Ia, a comparable fraction to core collapse (CC)
supernovae and the remaining are likely to be active galactic nuclei.
Interestingly, we have identified three intracluster SN candidates, all of
which lay beyond $R>r_{200}$. These events, if truly associated with the
cluster, indicate a large deficit of intracluster (IC) SN at smaller radii, and
may be associated with the IC stars of infalling groups or indicate that the
intracluster light (ICL) in the cluster outskirts is actively forming stars
which contribute CC SN or prompt SN Ia.


title: Orbital-quenching-induced magnetism in Ba_2NaOsO_6

abstract:
  The double perovskite \bnoo with heptavalent Os ($d^1$) is observed to remain
in the ideal cubic structure ({\it i.e.} without orbital ordering) despite
single occupation of the $t_{2g}$ orbitals, even in the ferromagnetically
ordered phase below 6.8 K. Analysis based on the {\it ab initio} dispersion
expressed in terms of an Os $t_{2g}$-based Wannier function picture, spin-orbit
coupling, Hund's coupling, and strong Coulomb repulsion shows that the magnetic
OsO$_6$ cluster is near a moment-less condition due to spin and orbital
compensation. Quenching (hybridization) then drives the emergence of the small
moment. This compensation, unprecedented in transition metals, arises in a
unified picture that accounts for the observed Mott insulating behavior.


title: A Logical Analysis of the Time-Warp Effect of General Relativity

abstract:
  Several versions of the Gravitational Time Dilation effect of General
Relativity are formulated by the use of Einstein's Equivalence Principle. It is
shown that all of them are logical consequence of a first-order axiom system of
Special Relativity extended to accelerated observers.


title: Activating Mg acceptors in AlN by oxygen: first principles calculations

abstract:
  First principles calculations based on density functional theory (DFT) are
performed to study the electronic properties of Mg acceptors in AlN at the
presence of oxygen. It is found that Mg and O tend to form complexes like Mg-O,
Mg$_2$-O, Mg$_3$-O and Mg$_4$-O which have activation energies about 0.23 eV
lower than that of Mg (except of the passive Mg-O). The lower activation
energies originate from the extra states over valence band top of AlN induced
by the passive Mg-O. By comparing to the well-established case of GaN, it is
possible to fabricate Mg and O codoped AlN without MgO precipitate. These
results suggest the possibility of achieving higher hole concentration in AlN
by Mg and O codoping.


title:
A Generalization of the Poincar\'e-Cartan Integral Invariant for a
  Nonlinear Nonholonomic Dynamical System

abstract:
  Based on the d'Alembert-Lagrange-Poincar\'{e} variational principle, we
formulate general equations of motion for mechanical systems subject to
nonlinear nonholonomic constraints, that do not involve Lagrangian undetermined
multipliers. We write these equations in a canonical form called the
Poincar\'{e}-Hamilton equations, and study a version of corresponding
Poincar\'{e}-Cartan integral invariant which are derived by means of a type of
asynchronous variation of the Poincar\'{e} variables of the problem that
involve the variation of the time. As a consequence, it is shown that the
invariance of a certain line integral under the motion of a mechanical system
of the type considered characterizes the Poincar\'{e}-Hamilton equations as
underlying equations of the motion. As a special case, an invariant analogous
to Poincar\'{e} linear integral invariant is obtained.


title: Cheon's anholonomies in Floquet operators

abstract:
  Anholonomies in the parametric dependences of the eigenvalues and the
eigenvectors of Floquet operators that describe unit time evolutions of
periodically driven systems, e.g., kicked rotors, are studied. First, an
example of the anholonomies induced by a periodically pulsed rank-1
perturbation is given. As a function of the strength of the perturbation, the
perturbed Floquet operator of the quantum map and its spectrum are shown to
have a period. However, we show examples where each eigenvalue does not obey
the periodicity of the perturbed Floquet operator and exhibits an anholonomy.
Furthermore, this induces another anholonomy in the eigenspaces, i.e., the
directions of the eigenvectors, of the Floquet operator. These two anholonomies
are previously observed in a family of Hamiltonians [T. Cheon, Phys. Lett. A
248, 285 (1998)] and are different from the phase anholonomy known as geometric
phases. Second, the stability of Cheon's anholonomies in periodically driven
systems is established by a geometrical analysis of the family of Floquet
operators. Accordingly, Cheon's anholonomies are expected to be abundant in
systems whose time evolutions are described by Floquet operators. As an
application, a design principle for quantum state manipulations along adiabatic
passages is explained.


title: H-Decompositions

abstract:
  We show that for all graphs H of size n, the complete graph $K_{2n+1}$ has an
$H$-decomposition.


title: Many body generalization of the Landau Zener problem

abstract:
  We formulate and approximately solve a specific many-body generalization of
the Landau-Zener problem. Unlike with the single particle Landau-Zener problem,
our system does not abide in the adiabatic ground state, even at very slow
driving rates. The structure of the theory suggests that this finding reflects
a more general phenomenon in the physics of adiabatically driven many particle
systems. Our solution can be used to understand, for example, the behavior of
two-level systems coupled to an electromagnetic field, as realized in cavity
QED experiments.


title:
Formation Process of a Light Bridge Revealed with the Hinode Solar
  Optical Telescope

abstract:
  The Solar Optical Telescope (SOT) aboard HINODE successfully and continuously
observed a formation process of a light bridge in a matured sunspot of the NOAA
active region 10923 for several days with high spatial resolution. During its
formation, many umbral dots were observed emerging from the leading edges of
penumbral filaments, and intruding into the umbra rapidly. The precursor of the
light bridge formation was also identified as the relatively slow inward motion
of the umbral dots which emerged not near the penumbra, but inside the umbra.
The spectro-polarimeter on SOT provided physical conditions in the photosphere
around the umbral dots and the light bridges. We found the light bridges and
the umbral dots had significantly weaker magnetic fields associated with
upflows relative to the core of the umbra, which implies that there was hot gas
with weak field strength penetrating from subphotosphere to near the visible
surface inside those structures. There needs to be a mechanism to drive the
inward motion of the hot gas along the light bridges. We suggest that the
emergence and the inward motion are triggered by a buoyant penumbral flux tube
as well as the subphotospheric flow crossing the sunspot.


title:
Confinement Induced Polarization effects in Valence and Inner-shell
  Spectra of Atactic Polystyrene

abstract:
  Vacuum ultraviolet (VUV) transmission spectra show a clear polarization
effect in pi electronic transition in spin coated atactic polystyrene (aPS)
films of thickness below 4Rg, where Rg (~20.4nm) is the radius of gyration of
the polymer. This transition associated with pendant benzene rings in
polystyrene. The polarization effect clearly indicates pendant benzene ring
alignment on a macroscopic scale. Study of core electron (1s) transition
through near edge x-ray absorption fine structure (NEXAFS) spectroscopy
confirms the ordering and shows that the rings are oriented towards
out-of-plane direction with a tilt angle ~63 degree with the sample plane,
which is consistent with the observed in-plane (sample surface) VUV
polarization. These results indicate the transition of a common polymer, like
polystyrene, inherently disordered in the bulk, to an orientationally ordered
phase under a certain degree of confinement.


title: A New Family of Somos-like Recurrences

abstract:
  We exhibit a three parameter infinite family of quadratic recurrence
relations inspired by the well known Somos sequences. For one infinite
subfamily we prove that the recurrence generates an infinite sequence of
integers by showing that the same sequence is generated by a linear recurrence
(with suitable initial conditions). We also give conjectured relations among
the three parameters so that the quadratic recurrences generate sequences of
integers.


title:
Three-boson problem at low energy and Implications for dilute
  Bose-Einstein condensates

abstract:
  It is shown that the effective interaction strength of three bosons at small
collision energies can be extracted from their wave function at zero energy. An
asymptotic expansion of this wave function at large interparticle distances is
derived, from which is defined a quantity $D$ named three-body scattering
hypervolume, which is an analog of the two-body scattering length. Given any
finite-range interaction potentials, one can thus predict the effective
three-body force from a numerical solution of the Schr\"{o}dinger equation. In
this way the constant $D$ for hard-sphere bosons is computed, leading to the
complete result for the ground state energy per particle of a dilute
Bose-Einstein condensate (BEC) of hard spheres to order $\rho^2$, where $\rho$
is the number density. Effects of $D$ are also demonstrated in the three-body
energy in a finite box of size $L$, which is expanded to the order $L^{-7}$,
and in the three-body scattering amplitude in vacuum. Another key prediction is
that there is a violation of the effective field theory (EFT) in the condensate
fraction in dilute BECs, caused by short-range physics. EFT predictions for the
ground state energy and few-body scattering amplitudes, however, are
corroborated.