title: Upper Limits from HESS AGN Observations in 2005-2007

abstract:
  AIMS: Very high energy (VHE; E>100 GeV) gamma-ray studies were performed for
18 active galactic nuclei (AGN) from a variety of AGN classes.
  METHODS: VHE observations of a sample of 14 AGN, considered candidate VHE
emitters, were made with the High Energy Stereoscopic System (HESS) between
January 2005 and July 2007. Large-zenith-angle observations of three northern
AGN (Mkn 421, Mkn 501, 1ES 1218+304), known to emit VHE gamma rays, were also
performed in order to sample their spectral energy distributions (SEDs) above 1
TeV. In addition, the VHE flux from 1ES 1101-232, previously detected by HESS
in 2004-2005, was monitored during 2006 and 2007.
  RESULTS: As significant detections from the HESS observation program are
reported elsewhere, the results reported here are primarily integral flux upper
limits. The average exposure for each of the 14 VHE-candidate AGN is ~7 h live
time, and the observations have an average energy threshold between 230 GeV and
590 GeV. Upper limits for these 14 AGN range from <0.9% to <4.9% of the Crab
Nebula flux, and eight of these are the most constraining ever reported for the
object. The brief (<2.2 h each) large-zenith-angle observations yield upper
limits for Mkn 501 (<20% Crab above 2.5 TeV) and 1ES 1218+304 (<17% Crab above
1.0 TeV), and a marginal detection (3.5 sigma) of Mkn 421 (50% Crab above 2.1
TeV). 1ES 1101-232 was marginally detected (3.6 sigma, 1.7% Crab above 260 GeV)
during the 2006 (13.7 h live time) observations, but not in the 2007 (4.6 h
live time) data. The upper limit in 2007 (<1.9% Crab above 260 GeV) is below
the average flux measured by HESS from 2004-2006.


title: How to realize "a sense of humour" in computers ?

abstract:
  Computer model of a "sense of humour" suggested previously [arXiv:0711.2058,
0711.2061, 0711.2270] is raised to the level of a realistic algorithm.


title:
On the global well-posedness of the Boussinesq system with zero
  viscosity

abstract:
  In this paper we prove the global well-posedness of the two-dimensional
Boussinesq system with zero viscosity for rough initial data.


title:
Analyzing and Modeling Real-World Phenomena with Complex Networks: A
  Survey of Applications

abstract:
  The success of new scientific areas can be assessed by their potential for
contributing to new theoretical approaches and in applications to real-world
problems. Complex networks have fared extremely well in both of these aspects,
with their sound theoretical basis developed over the years and with a variety
of applications. In this survey, we analyze the applications of complex
networks to real-world problems and data, with emphasis in representation,
analysis and modeling, after an introduction to the main concepts and models. A
diversity of phenomena are surveyed, which may be classified into no less than
22 areas, providing a clear indication of the impact of the field of complex
networks.


title: Towards a theory of classification

abstract:
  The well-known difficulties arising in a classification which is not
set-theoretically trivial---involving what is sometimes called a non-smooth
quotient---have been overcome in a striking way in the theory of operator
algebras by the use of what might be called a classification functor---the very
existence of which is already a surprise. Here the notion of such a functor is
developed abstractly, and a number of examples are considered (including those
which have arisen for various classes of operator algebras).


title: Polynomial largeness of sumsets and totally ergodic sets

abstract:
  We prove that a sumset of a TE subset of (\N) (these sets can be viewed as
"aperiodic" sets) with a set of positive upper density intersects a set of
values of any polynomial with integer coefficients., i.e. for any (A \subset \N
) a TE set, for any (p(n) \in \Z[n]: \deg{p(n)} > 0, p(n) \to_{n \to \infty}
\infty ) and any subset (B \subset \N ) of positive upper density we have (R_p
= A+B \cap \{p(n) | n \in \N \} \neq \emptyset). For (A ) a WM set (subclass of
TE sets) we prove that (R_p ) has lower density 1. In addition we obtain a
generalization of the latter result to the case of several polynomials and
several WM sets.


title: Conductivity and Fano factor in disordered graphene

abstract:
  Using the recursive Green's function method, we study the problem of electron
transport in a disordered single-layer graphene sheet. The conductivity is of
order $e^2/h$ and its dependence on the carrier density has a scaling form that
is controlled solely by the disorder strength and the ratio between the sample
size and the correlation length of the disorder potential. The shot noise Fano
factor is shown to have a narrow dip near the neutrality point for weak
disorder and to develop a nearly doping independent behavior at strong
disorder. Our results are in good qualitative and quantitative agreement with
experiments and provide a way for extracting microscopic information about the
magnitude of extrinsic disorder in graphene.


title: Theory of x-ray absorption by laser-aligned symmetric-top molecules

abstract:
  We devise a theory of x-ray absorption by symmetric-top molecules which are
aligned by an intense optical laser. Initially, the density matrix of the
system is composed of the electronic ground state of the molecules and a
thermal ensemble of rigid-rotor eigenstates. We formulate equations of motion
of the two-color (laser plus x rays) rotational-electronic problem. The
interaction with the laser is assumed to be nonresonant; it is described by an
electric dipole polarizability tensor. X-ray absorption is approximated as a
one-photon process. It is shown that the equations can be separated such that
the interaction with the laser can be treated independently of the x rays. The
laser-only density matrix is propagated numerically. After each time step, the
x-ray absorption is calculated. We apply our theory to study adiabatic
alignment of bromine molecules (Br2). The required dynamic polarizabilities are
determined using the ab initio linear response methods coupled-cluster singles
(CCS), second-order approximate coupled-cluster singles and doubles (CC2), and
coupled-cluster singles and doubles (CCSD). For the description of x-ray
absorption on the sigma_g 1s --> sigma_u 4p resonance, a parameter-free
two-level model is used for the electronic structure of the molecules. Our
theory opens up novel perspectives for the quantum control of x-ray radiation.


title: Fractional Quantum Hall Hierarchy and the Second Landau Level

abstract:
  We generalize the fractional quantum Hall hierarchy picture to apply to
arbitrary, possibly non-Abelian, fractional quantum Hall states. Applying this
to the nu = 5/2 Moore-Read state, we construct new explicit trial wavefunctions
to describe the fractional quantum Hall effect in the second Landau level. The
resulting hierarchy of states, which reproduces the filling fractions of all
observed Hall conductance plateaus in the second Landau level, is characterized
by electron pairing in the ground state and an excitation spectrum that
includes non-Abelian anyons of the Ising type. We propose this as a unifying
picture in which p-wave pairing characterizes the fractional quantum Hall
effect in the second Landau level.


title:
Relay Subset Selection in Wireless Networks Using Partial
  Decode-and-Forward Transmission

abstract:
  This paper considers the problem of selecting a subset of nodes in a two-hop
wireless network to act as relays in aiding the communication between the
source-destination pair. Optimal relay subset selection with the objective of
maximizing the overall throughput is a difficult problem that depends on
multiple factors including node locations, queue lengths and power consumption.
A partial decode-and-forward strategy is applied in this paper to improve the
tractability of the relay selection problem and performance of the overall
network.
  Note that the number of relays selected ultimately determines the performance
of the network. This paper benchmarks this performance by determining the net
diversity achieved using the relays selected and the partial decode-and-forward
strategy. This framework is subsequently used to further transform relay
selection into a simpler relay placement problem, and two proximity-based
approximation algorithms are developed to determine the appropriate set of
relays to be selected in the network. Other selection strategies such as random
relay selection and a greedy algorithm that relies on channel state information
are also presented. This paper concludes by showing that the proposed
proximity-based relay selection strategies yield near-optimal expected rates
for a small number of selected relays.


title: Shot Noise in Graphene

abstract:
  We report measurements of current noise in single- and multi-layer graphene
devices. In four single-layer devices, including a p-n junction, the Fano
factor remains constant to within +/-10% upon varying carrier type and density,
and averages between 0.35 and 0.38. The Fano factor in a multi-layer device is
found to decrease from a maximal value of 0.33 at the charge-neutrality point
to 0.25 at high carrier density. These results are compared to theoretical
predictions for shot noise in ballistic and disordered graphene.


title:
Search for sneutrino particles in e + mu final states in ppbar
  collisions at sqrt{s} =1.96 TeV

abstract:
  We report a search for R-parity violating production and decay of sneutrino
particles in the e+mu final state with 1.04+-0.06 fb-1 of data collected with
the D0 detector at the Fermilab Tevatron Collider in 2002--2006. Good agreement
between the data and the standard model prediction is observed. With no
evidence for new physics, we set limits on the R-parity violating couplings
$\lambda^{\prime}_{311}$ and $\lambda_{312}$ as a function of sneutrino mass.


title:
The Riemann-Hilbert approach to double scaling limit of random matrix
  eigenvalues near the "birth of a cut" transition

abstract:
  In this paper we studied the double scaling limit of a random unitary matrix
ensemble near a singular point where a new cut is emerging from the support of
the equilibrium measure. We obtained the asymptotic of the correlation kernel
by using the Riemann-Hilbert approach. We have shown that the kernel near the
critical point is given by the correlation kernel of a random unitary matrix
ensemble with weight $e^{-x^{2\nu}}$. This provides a rigorous proof of the
previous results of Eynard.


title: Influence of AGN Outbursts on the Surrounding Galaxies

abstract:
  We study the influence of a strong AGN outburst on the surrounding galaxies.
The AGN is assumed to reside in a group of galaxies, and an outburst excites a
shock wave in the hot gas in the group. We calculate the impact of the shock
wave on the galaxies. We find that if the energy of the outburst is extremely
large (E_AGN ~6x10^61 erg) as the one recently observed in clusters, the impact
is strong enough to strip the cold interstellar medium in the disc of the
galaxies in the inner region of the group. Moreover, even in the outer region
of the group, the warm gas in the halo of the galaxies would be stripped, even
if the energy of the outburst is ~6x10^60 erg. These would decrease star
formation activity of the galaxies. If these galaxies fall into the group
centre through dynamical friction and their interstellar medium is the fuel of
the supermassive black hole in the AGN, the outburst would serve as feedback.
While this mechanism works only when E_AGN is extremely large, such outbursts
have not been observed in groups at low redshift; it would work at high
redshift rather than at low redshift.


title: Brane Induced Gravity: Codimension-2

abstract:
  We review the results of arXiv:hep-th/0703190, on brane induced gravity (BIG)
in 6D. Among a large diversity of regulated codimension-2 branes, we find that
for near-critical tensions branes live inside very deep throats which
efficiently compactify the angular dimension. In there, 4D gravity first
changes to 5D, and only later to 6D. The crossover from 4D to 5D is independent
of the tension, but the crossover from 5D to 6D is not. This shows how the
vacuum energy problem manifests in BIG: instead of tuning vacuum energy to
adjust the 4D curvature, generically one must tune it to get the desired
crossover scales and the hierarchy between the scales governing the 4D \to 5D
\to 6D transitions. In the near-critical limit, linearized perturbation theory
remains under control below the crossover scale, and we find that linearized
gravity around the vacuum looks like a scalar-tensor theory.


title: Hypercharged Anomaly Mediation

abstract:
  We show that, in string models with the MSSM residing on D-branes, the bino
mass can be generated in a geometrically separated hidden sector. Hypercharge
mediation thus naturally teams up with anomaly mediation. The mixed scenario
predicts a distinctive yet viable superpartner spectrum, provided that the
ratio \alpha between the bino and gravitino mass lies in the range 0.05 <
|\alpha| < 0.25, and m_{3/2} > 35 TeV. We summarize some of the
phenomenological features of this scenario.


title: Limits on Hot Galactic Halo Gas from X-ray Absorption Lines

abstract:
  Although the existence of large-scale hot gaseous halos around massive disk
galaxies have been theorized for a long time, there is yet very little
observational evidence. We report the Chandra and XMM-Newton grating spectral
detection of OVII and NeIX Kalpha absorption lines along the sight-line of 4U
1957+11. The line absorption is consistent with the interstellar medium in
origin. Attributing these line absorptions to the hot gas associated with the
Galactic disk, we search for the gaseous halo around the Milky Way by comparing
this sight-line with more distant ones (toward X-ray binary LMC X-3 and the AGN
Mrk 421). We find that all the line absorptions along the LMC X-3 and Mrk 421
sight-lines are attributable to the hot gas in a thick Galactic disk, as traced
by the absorption lines in the spectra of 4U~1957+11 after a Galactic latitude
dependent correction. We constrain the OVII column density through the halo to
be N(OVII) < 5E15 cm^{-2} (95% confidence limit), and conclude that the hot gas
contribution to the metal line absorptions, if existing, is negligible.


title:
Satisfying the fluctuation theorem in free energy calculations with
  Hamiltonian replica exchange

abstract:
  A novel error measure, referred to as the hysteresis error, is developed from
the Crooks fluctuation theorem to evaluate sampling quality in free energy
calculations. Theory and numerical free energy of hydration calculations are
used to show that Hamiltonian replica exchange provides a direct route for
minimizing the hysteresis error. Replica exchange swap probabilies yield the
rate at which the hysteresis error falls with simulation length, and this
result can be used to decrease bias and statistical errors associated with free
energy calculations based on multicanonical simulations.


title: A Higher Form (of) Mediation

abstract:
  We exhibit a simple and robust mechanism for mediation of supersymmetry
breaking between geometrically separated D-branes in type II string theory. The
mediation proceeds via RR p-forms that couple via linear Chern-Simons terms to
the abelian vector bosons on the branes. From a 4-d low energy perspective, the
mechanism reduces to U(1) mediation.


title: How is Exotics Produced ? Where to Search for it ?

abstract:
  On the basis of existing data, we suggest such a mechanism of production for
exotic hadrons that can explain, at least qualitatively, why the Theta+-baryon
is seen in some experiments and not in others. With our hypothesis, production
of exotic hadrons is a new kind of hard processes. We also can propose new
experiments to check (and confirm?) existence of exotics and to provide new
important information about both exotic and conventional hadrons [The talk is
based on the papers by Ya. Azimov, K. Goeke, and I. Strakovsky, Phys Rev D 76,
074013 (2007)]


title:
Quantized charge pumping in superconducting double barrier structure :
  Non-trivial correlations due to proximity effect

abstract:
  We consider quantum charge pumping of electrons across a superconducting
double barrier structure in the adiabatic limit. The superconducting barriers
are assumed to be reflection-less so that an incident electron on the barrier
can either tunnel through it or Andreev reflect from it. In this structure,
quantum charge pumping can be achieved (a) by modulating the amplitudes,
$\Delta_1$ and $\Delta_2$ of the two superconducting gaps or alternatively, (b)
by a periodic modulation of the order parameter phases, $\phi_1$ and $\phi_2$
of the superconducting barriers. In the former case, we show that the
superconducting gap gives rise to a very sharp resonance in the transmission
resulting in quantization of pumped charge, when the pumping contour encloses
the resonance. On the other hand, we find that quantization is hard to achieve
in the latter case. We show that inclusion of weak electron-electron
interaction in the quantum wire leads to renormalisation group evolution of the
transmission amplitude towards the perfectly transmitting limit due to
proximity effects. Hence as we approach the zero temperature limit, we get
destruction of quantized pumped charge. This is in sharp contrast to the case
of charge pumping in a double barrier in a Luttinger liquid where quantized
charge pumping is actually achieved in the zero temperature limit. We also
propose an experimental set-up to study these effects.


title: The ATLAS High Level Trigger Region of Interest Builder

abstract:
  This article describes the design, testing and production of the ATLAS Region
of Interest Builder (RoIB). This device acts as an interface between the Level
1 trigger and the high level trigger (HLT) farm for the ATLAS LHC detector. It
distributes all of the level 1 data for a subset of events to a small number of
(16 or less) individual commodity processors. These processors in turn provide
this information to the HLT. This allows the HLT to use the level 1 information
to narrow data requests to areas of the detector where level 1 has identified
interesting objects.


title:
An Integral Measure of Aging/Rejuvenation for Repairable and
  Non-repairable Systems

abstract:
  This paper introduces a simple index that helps to assess the degree of aging
or rejuvenation of a (non)repairable system. The index ranges from -1 to 1 and
is negative for the class of decreasing failure rate distributions (or
deteriorating point processes) and is positive for the increasing failure rate
distributions (or improving point processes). The introduced index is
distribution free.


title: Annihilators of permutation modules

abstract:
  Permutation modules are fundamental in the representation theory of symmetric
groups $\Sym_n$ and their corresponding Iwahori--Hecke algebras $\He =
\He(\Sym_n)$. We find an explicit combinatorial basis for the annihilator of a
permutation module in the "integral" case -- showing that it is a cell ideal in
G.E. Murphy's cell structure of $\He$. The same result holds whenever $\He$ is
semisimple, but may fail in the non-semisimple case.


title: Fourvector algebra

abstract:
  The algebra of fourvectors is described. The fourvectors are more appropriate
than the Hamilton quaternions for its use in Physics and the sciences in
general. The fourvectors embrace the 3D vectors in a natural form. It is shown
the excellent ability to perform rotations with the use of fourvectors, as well
as their use in relativity for producing Lorentz boosts, which are understood
as simple rotations.


title: Topological dynamics of the Weil-Petersson geodesic flow

abstract:
  We prove topological transitivity for the Weil Petersson geodesic flow for
two-dimensional moduli spaces of hyperbolic structures. Our proof follows a new
approach that exploits the density of singular unit tangent vectors, the
geometry of cusps and convexity properties of negative curvature. We also show
that the Weil Petersson geodesic flow has: horseshoes, invariant sets with
positive topological entropy, and that there are infinitely many hyperbolic
closed geodesics, whose number grows exponentially in length. Furthermore, we
note that the volume entropy is infinite.


title: Quantum fields, Noether charges and \kappa-spacetime symmetries

abstract:
  We discuss how the symmetries of $\kappa$-Minkowski non-commutative spacetime
can be described by the $\kappa$-Poincar\'e Hopf algebra. In particular, we
focus on a generalization of the Noether analysis in the $\kappa$-deformed
framework which allows us to introduce Noether charges associated with
translational symmetries and makes possible to overcome the apparent
ambiguities that seemed to be associated with the action of such symmetries.
Moving from the classical to the quantum framework, we will first review past
results on path integral quantization of a scalar self-interacting field. We
will then show how recent work on the symplectic structure of classical
$\kappa$-fields suggests a new approach to the canonical quantization of free
fields and and present some new results.


title: QE Neutrino CC Cross Sections off 16O

abstract:
  The charged-current quasi-elastic scattering of muon neutrino on oxygen
target is computed for neutrino energy between 200 MeV and 2.5 GeV using
different approximations: the Plane Wave Impulse Approximation (PWIA), the
Relativistic Distorted Wave Impulse Approximation with relativistic optical
potential (RDWIA), and the Relativistic Fermi Gas Model (RFGM). The comparison
with RFGM, which is widely used in data analyses of neutrino experiments, shows
that the RFGM fails completely when applied to exclusive cross section data and
leads to overestimated values of inclusive and total cross sections.


title:
Base manifolds for fibrations of projective irreducible symplectic
  manifolds

abstract:
  Given a projective irreducible symplectic manifold $M$ of dimension $2n$, a
projective manifold $X$ and a surjective holomorphic map $f:M \to X$ with
connected fibers of positive dimension, we prove that $X$ is biholomorphic to
the projective space of dimension $n$. The proof is obtained by exploiting two
geometric structures at general points of $X$: the affine structure arising
from the action variables of the Lagrangian fibration $f$ and the structure
defined by the variety of minimal rational tangents on the Fano manifold $X$.


title:
Strong Coupling Corrections to the Ginzburg-Landau Theory of Superfluid
  ^{3}He

abstract:
  In the Ginzburg-Landau theory of superfluid $^{3}$He, the free energy is
expressed as an expansion of invariants of a complex order parameter. Strong
coupling effects, which increase with increasing pressure, are embodied in the
set of coefficients of these order parameter invariants\cite{Leg75,Thu87}.
Experiments can be used to determine four independent combinations of the
coefficients of the five fourth order invariants. This leaves the
phenomenological description of the thermodynamics near $T_{c}$ incomplete.
Theoretical understanding of these coefficients is also quite limited. We
analyze our measurements of the magnetic susceptibility and the NMR frequency
shift in the $B$-phase which refine the four experimental inputs to the
phenomenological theory. We propose a model based on existing experiments,
combined with calculations by Sauls and Serene\cite{Sau81} of the pressure
dependence of these coefficients, in order to determine all five fourth order
terms. This model leads us to a better understanding of the thermodynamics of
superfluid $^{3}$He in its various states. We discuss the surface tension of
bulk superfluid $^{3}$He and predictions for novel states of the superfluid
such as those that are stabilized by elastic scattering of quasiparticles from
a highly porous silica aerogel.


title: Supersymmetric Wilson loops on S^3

abstract:
  This paper studies in great detail a family of supersymmetric Wilson loop
operators in N=4 supersymmetric Yang-Mills theory we have recently found. For a
generic curve on an S^3 in space-time the loops preserve two supercharges but
we will also study special cases which preserve 4, 8 and 16 supercharges. For
certain loops we find the string theory dual explicitly and for the general
case we show that string solutions satisfy a first order differential equation.
This equation expresses the fact that the strings are pseudo-holomorphic with
respect to a novel almost complex structure we construct on AdS_4 x S^2. We
then discuss loops restricted to S^2 and provide evidence that they can be
calculated in terms of similar observables in purely bosonic YM in two
dimensions on the sphere.


title: Rare White dwarf stars with carbon atmospheres

abstract:
  White dwarfs represent the endpoint of stellar evolution for stars with
initial masses between approximately 0.07 msun and 8-10 msun, where msun is the
mass of the Sun (more massive stars end their life as either black holes or
neutron stars). The theory of stellar evolution predicts that the majority of
white dwarfs have a core made of carbon and oxygen, which itself is surrounded
by a helium layer and, for ~80 per cent of known white dwarfs, by an additional
hydrogen layer. All white dwarfs therefore have been traditionally found to
belong to one of two categories: those with a hydrogen-rich atmosphere (the DA
spectral type) and those with a helium-rich atmosphere (the non-DAs). Here we
report the discovery of several white dwarfs with atmospheres primarily
composed of carbon, with little or no trace of hydrogen or helium. Our analysis
shows that the atmospheric parameters found for these stars do not fit
satisfactorily in any of the currently known theories of post-asymptotic giant
branch evolution, although these objects might be the cooler counterpart of the
unique and extensively studied PG1159 star H1504+65. These stars, together with
H1504+65, might accordingly form a new evolutionary sequence that follow the
asymptotic giant branch.


title: One loop superstring effective actions and d=4 supergravity

abstract:
  We review our recent work on the existence of a new independent R^4 term, at
one loop, in the type IIA and heterotic effective actions, after reduction to
four dimensions, besides the usual square of the Bel-Robinson tensor. We
discuss its supersymmetrization.


title:
Liv\v{s}ic Theorems for Non-Commutative Groups including Diffeomorphism
  Groups and Results on the Existence of Conformal Structures for Anosov
  Systems

abstract:
  The celebrated Livsic theorem states that given M a manifold, a Lie group G,
a transitive Anosov diffeomorphism f on M and a Holder function \eta: M \mapsto
G whose range is sufficiently close to the identity, it is sufficient for the
existence of \phi :M \mapsto G satisfying \eta(x) = \phi(f(x)) \phi(x)^{-1}
that a condition -- obviously necessary -- on the cocycle generated by \eta
restricted to periodic orbits is satisfied. In this paper we present a new
proof of the main result. These methods allow us to treat cocycles taking
values in the group of diffeomorphisms of a compact manifold. This has
applications to rigidity theory. The localization procedure we develop can be
applied to obtain some new results on the existence of conformal structures for
Anosov systems.


title: Many-body Landau-Zener tunneling in the Bose-Hubbard model

abstract:
  We study a model for ultracold, spinless atoms in quasi-one dimensional
optical lattices and subjected to a tunable tilting force. Statistical tests
are employed to quantitatively characterize the spectrum of the Floquet-Bloch
operator of the system along the transition from the regular to the quantum
chaotic regime. Moreover, we perturbatively include the coupling of the
one-band model to the second energy band. This allows us to study the
Landau-Zener interband tunneling within a truly many-body description of
ultracold atoms. The distributions of the computed tunneling rates provide an
independent and experimentally accessible signature of the regular-chaotic
transition.


title: Highly Frustrated Magnetic Clusters: The kagome on a sphere

abstract:
  We present a detailed study of the low-energy excitations of two existing
finite-size realizations of the planar kagome Heisenberg antiferromagnet on the
sphere, the cuboctahedron and the icosidodecahedron. After highlighting a
number of special spectral features (such as the presence of low-lying singlets
below the first triplet and the existence of localized magnons) we focus on two
major issues. The first concerns the nature of the excitations above the
plateau phase at 1/3 of the saturation magnetization Ms. Our exact
diagonalizations for the s=1/2 icosidodecahedron reveal that the low-lying
plateau states are adiabatically connected to the degenerate collinear
``up-up-down'' ground states of the Ising point, at the same time being well
isolated from higher excitations. A complementary physical picture emerges from
the derivation of an effective quantum dimer model which reveals the central
role of the topology and the intrinsic spin s. We also give a prediction for
the low energy excitations and thermodynamic properties of the spin s=5/2
icosidodecahedron Mo72Fe30. In the second part we focus on the low-energy
spectra of the s>1/2 Heisenberg model in view of interpreting the broad
inelastic neutron scattering response reported for Mo72Fe30. To this end we
demonstrate the simultaneous presence of several broadened low-energy ``towers
of states'' or ``rotational bands'' which arise from the large discrete spatial
degeneracy of the classical ground states, a generic feature of highly
frustrated clusters. This semiclassical interpretation is further corroborated
by their striking symmetry pattern which is shown, by an independent group
theoretical analysis, to be a characteristic fingerprint of the classical
coplanar ground states.


title:
Is NGC 3108 transforming itself from an early to late type galaxy -- an
  astronomical hermaphrodite?

abstract:
  A common feature of hierarchical galaxy formation models is the process of
"inverse" morphological transformation: a bulge dominated galaxy accretes a gas
disk, dramatically reducing the system's bulge-to-disk mass ratio. During their
formation, present day galaxies may execute many such cycles across the Hubble
diagram. A good candidate for such a "hermaphrodite" galaxy is NGC 3108: a
dust-lane early-type galaxy which has a large amount of HI gas distributed in a
large scale disk. We present narrow band H_alpha and R-band imaging, and
compare the results with the HI distribution. The emission is in two
components: a nuclear bar and an extended disk component which coincides with
the HI distribution. This suggests that a stellar disk is currently being
formed out of the HI gas. The spatial distributions of the H_alpha and HI
emission and the HII regions are consistent with a barred spiral structure,
extending some 20 kpc in radius. We measure an extinction- corrected SFR of
0.42 Msun/yr. The luminosity function of the HII regions is similar to other
spiral galaxies, with a power law index of -2.1, suggesting that the star
formation mechanism is similar to other spiral galaxies. We measured the
current disk mass and find that it is too massive to have been formed by the
current SFR over the last few Gyr. It is likely that the SFR in NGC 3108 was
higher in the past. With the current SFR, the disk in NGC 3108 will grow to be
~6.2x10^9 Msun in stellar mass within the next 5.5 Gyr. While this is
substantial, the disk will be insignificant compared with the large bulge mass:
the final stellar mass disk-to-bulge ratio will be ~0.02. NGC 3108 will fail to
transform into anything resembling a spiral without a boost in the SFR and
additional supply of gas.


title: Counting the negative eigenvalues of the thermalon in three dimensions

abstract:
  Some years ago it was shown that the cosmological constant may be reduced by
thermal production of membranes that, after nucleation, collapse into a black
hole. The probability of the process was calculated in the leading
semiclassical approximation by studying an associated Euclidean configuration
called the thermalon. Here we investigate the thermalon in three spacetime
dimensions, describing the nucleation of closed strings that collapse into
point particle singularities. In this context we may analyze the one-loop
structure without the well known problems brought in by the propagating
gravitational degrees of freedom. We found that the coupling to gravity may
increase the number of negative eigenvalues of the operator.


title: Constraints on Gauss-Bonnet Cosmologies

abstract:
  The modified Gauss-Bonnet gravity can be motivated by a number of physical
reasons, including: the uniqueness of a gravitational Lagrangian in four and
higher dimensions and the leading order $\alpha^\prime$ corrections in
superstring theory. Such an effective theory of scalar-tensor gravity has been
modeled in the recent past to explain both the initial cosmological singularity
problem and the observationally supported cosmological perturbations. Here I
present an overview of the recent developments in the use of modified
Gauss-Bonnet gravity to explain current observations, touching on key
cosmological and astrophysical constraints applicable to theories of
scalar-tensor gravity. The Gauss-Bonnet type modification of Einstein's theory
admits nonsingular solutions for a wide range of scalar-curvature couplings. It
also provides plausible explanation to some outstanding cosmological
conundrums, including: the transition from matter dominance to dark energy and
the late time cosmic acceleration. The focus is placed here to constrain such
an effective theory of gravity against the recent cosmological and
astrophysical observations.


title: A Game-Theoretic Analysis of Updating Sets of Probabilities

abstract:
  We consider how an agent should update her uncertainty when it is represented
by a set $\P$ of probability distributions and the agent observes that a random
variable $X$ takes on value $x$, given that the agent makes decisions using the
minimax criterion, perhaps the best-studied and most commonly-used criterion in
the literature. We adopt a game-theoretic framework, where the agent plays
against a bookie, who chooses some distribution from $\P$. We consider two
reasonable games that differ in what the bookie knows when he makes his choice.
Anomalies that have been observed before, like time inconsistency, can be
understood as arising important because different games are being played,
against bookies with different information. We characterize the important
special cases in which the optimal decision rules according to the minimax
criterion amount to either conditioning or simply ignoring the information.
Finally, we consider the relationship between conditioning and calibration when
uncertainty is described by sets of probabilities.


title: Confidence intervals in regression utilizing prior information

abstract:
  We consider a linear regression model with regression parameter
beta=(beta_1,...,beta_p) and independent and identically N(0,sigma^2)
distributed errors. Suppose that the parameter of interest is theta = a^T beta
where a is a specified vector. Define the parameter tau=c^T beta-t where the
vector c and the number t are specified and a and c are linearly independent.
Also suppose that we have uncertain prior information that tau = 0. We present
a new frequentist 1-alpha confidence interval for theta that utilizes this
prior information. We require this confidence interval to (a) have endpoints
that are continuous functions of the data and (b) coincide with the standard
1-alpha confidence interval when the data strongly contradicts this prior
information. This interval is optimal in the sense that it has minimum weighted
average expected length where the largest weight is given to this expected
length when tau=0. This minimization leads to an interval that has the
following desirable properties. This interval has expected length that (a) is
relatively small when the prior information about tau is correct and (b) has a
maximum value that is not too large. The following problem will be used to
illustrate the application of this new confidence interval. Consider a 2-by 2
factorial experiment with 20 replicates. Suppose that the parameter of interest
theta is a specified simple effect and that we have uncertain prior information
that the two-factor interaction is zero. Our aim is to find a frequentist 0.95
confidence interval for theta that utilizes this prior information.


title:
Supernova Relic Electron Neutrinos and anti-Neutrinos in future
  Large-scale Observatories

abstract:
  We investigate the signal from supernova relic neutrinos in future large
scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at
present under study. We discuss that complementary information might be gained
from the observation of supernova relic electron anti-neutrinos and neutrinos
using the scattering on protons on one hand, and on nuclei such as oxygen,
carbon or argon on the other hand. When determining the relic neutrino fluxes
we also include, for the first time, the coupling of the neutrino magnetic
moment to magnetic fields within the core-collapse supernova. We present
numerical results on both the relic electron neutrino and anti-neutrino fluxes
and on the number of events for electron neutrinos on carbon, oxygen and argon,
as well as electron anti-neutrinos on protons, for various oscillation
scenarios. The observation of supernova relic neutrinos might provide us with
unique information on core-collapse supernova explosions, on the star formation
history and on neutrino properties, that still remain unknown.


title:
Suppression of molecular decay in ultracold gases without Fermi
  statistics

abstract:
  We study inelastic processes for ultracold three-body systems in which only
one interaction is resonant. We have found that the decay rates for weakly
bound molecules due to collisions with other atoms can be suppressed not only
without fermionic statistics but also when bosonic statistics applies. In
addition, we show that at ultracold temperatures three-body recombination
involving a single resonant pair of atoms leads mainly to formation of weakly
bound molecules which, in turn, are stable against decay. These results
indicate that recombination in three-component atomic gases can be used as an
efficient mechanism for molecular formation, allowing the achievement of high
molecular densities.


title: A deductive statistical mechanics approach for granular matter

abstract:
  We introduce a deductive statistical mechanics approach for granular
materials which is formally built from few realistic physical assumptions. The
main finding is an universal behavior for the distribution of the density
fluctuations. Such a distribution is the equivalent of the Maxwell-Boltzmann's
distribution in the kinetic theory of gasses. The comparison with a very
extensive set of experimental and simulation data for packings of monosized
spherical grains, reveals a remarkably good quantitative agreement with the
theoretical predictions for the density fluctuations both at the grain level
and at the global system level. Such agreement is robust over a broad range of
packing fractions and it is observed in several distinct systems prepared by
using different methods. The equilibrium distributions are characterized by
only one parameter ($k$) which is a quantity very sensitive to changes in the
structural organization. The thermodynamical equivalent of $k$ and its relation
with the `granular temperature' are also discussed.


title: Higher derivative correction to Kaluza-Klein black hole solution

abstract:
  We investigate the attractor mechanism in Kaluza-Klein black hole solution in
the presence of higher derivative terms. In particular, we discuss the
attractor behavior of static black holes by using the effective potential
approach as well as entropy function formalism. We consider different higher
derivative terms with a general coupling to moduli field. For the $R^2$ theory,
we use effective potential approach, looking for solutions which are analytic
near the horizon and show that they exist and enjoy the attractor behavior. The
attractor point is determined by extremization of the modified effective
potential at the horizon. We study the effect of the general higher derivative
corrections of $R^n$ terms. Using the entropy function we define the modified
effective potential and we find the conditions to have the attractor solution.
In particular for a single charged Kaluza-Klein black hole solution we show
that higher derivative correction dresses the naked singularity for an
appropriate coupling, and we can find the attractor solution.


title: Josephson Effect between Conventional and Rashba Superconductors

abstract:
  We study the Josephson effect between a conventional s-wave superconductor
and a non-centrosymmetric superconductor with Rashba spin-orbit coupling.
Rashba spin-orbit coupling affects the Josephson pair tunneling in a
characteristic way. The Josephson coupling can be decomposed into two parts, a
`spin-singlet-like' and a `spin-triplet-like' component. The latter component
can lead to shift of the Josephson phase by \pi relative to the former
coupling. This has important implications on interference effects and may
explain some recent experimental results for the Al/CePt3Si junction.


title: On the Centroids of Symmetrized Bregman Divergences

abstract:
  In this paper, we generalize the notions of centroids and barycenters to the
broad class of information-theoretic distortion measures called Bregman
divergences. Bregman divergences are versatile, and unify quadratic geometric
distances with various statistical entropic measures. Because Bregman
divergences are typically asymmetric, we consider both the left-sided and
right-sided centroids and the symmetrized centroids, and prove that all three
are unique. We give closed-form solutions for the sided centroids that are
generalized means, and design a provably fast and efficient approximation
algorithm for the symmetrized centroid based on its exact geometric
characterization that requires solely to walk on the geodesic linking the two
sided centroids. We report on our generic implementation for computing entropic
centers of image clusters and entropic centers of multivariate normals, and
compare our results with former ad-hoc methods.


title: A quasi-local mass for 2-spheres with negative Gauss curvature

abstract:
  We extend our previous definition of quasi-local mass to 2-spheres whose
Gauss curvature is negative and prove its positivity.


title:
Doppler-free, Multi-wavelength Acousto-optic deflector for two-photon
  addressing arrays of Rb atoms in a Quantum Information Processor

abstract:
  We demonstrate a dual wavelength acousto-optic deflector (AOD) designed to
deflect two wavelengths to the same angles by driving with two RF frequencies.
The AOD is designed as a beam scanner to address two-photon transitions in a
two-dimensional array of trapped neutral Rb atoms in a quantum computer.
Momentum space is used to design AODs that have the same diffraction angles for
two wavelengths (780 nm and 480 nm) and have non-overlapping Bragg-matched
frequency response at these wavelengths, so that there will be no crosstalk
when proportional RF frequencies are applied to diffract the two wavelengths.
The appropriate crystal orientation, crystal shape, transducer size, and
transducer height are determined for an AOD made with a Tellurium dioxide
crystal (TeO2). The designed and fabricated AOD has more than 100 resolvable
spots, widely separated bandshapes for the two wavelengths within an overall
octave bandwidth, spatially overlapping diffraction angles for both wavelengths
(780 nm and 480 nm), and a 4 usec or less access time. Cascaded AODs in which
the first device upshifts and the second downshifts allow Doppler-free scanning
as required for addressing the narrow atomic resonance without detuning. We
experimentally show the diffraction-limited Doppler-free scanning performance
and spatial resolution of the designed AOD.


title:
Singlet-Triplet Physics and Shell Filling in Carbon Nanotube Double
  Quantum Dots

abstract:
  An artifcial two-atomic molecule, also called a double quantum dot (DQD), is
an ideal system for exploring few electron physics. Spin-entanglement between
just two electrons can be explored in such systems where singlet and triplet
states are accessible. These two spin-states can be regarded as the two states
in a quantum two-state system, a so-called singlet-triplet qubit. A very
attractive material for realizing spin based qubits is the carbon nanotube
(CNT), because it is expected to have a very long spin coherence time. Here we
show the existence of a gate-tunable singlet-triplet qubit in a CNT DQD. We
show that the CNT DQD has clear shell structures of both four and eight
electrons, with the singlet-triplet qubit present in the four-electron shells.
We furthermore observe inelastic cotunneling via the singlet and triplet
states, which we use to probe the splitting between singlet and triplet, in
good agreement with theory.


title: Sequence dependence of DNA translocation through a nanopore

abstract:
  We investigate the dynamics of DNA translocation through a nanopore using 2D
Langevin dynamics simulations, focusing on the dependence of the translocation
dynamics on the details of DNA sequences. The DNA molecules studied in this
work are built from two types of bases $A$ and $C$, which has been shown
previously to have different interactions with the pore. We study DNA with
repeating blocks $A_nC_n$ for various values of $n$, and find that the
translocation time depends strongly on the {\em block length} $2n$ as well as
on the {\em orientation} of which base entering the pore first. Thus, we
demonstrate that the measurement of translocation dynamics of DNA through
nanopore can yield detailed information about its structure. We have also found
that the periodicity of the block sequences are contained in the periodicity of
the residence time of the individual nucleotides inside the pore.


title: A Distributed Dynamic Frequency Allocation Algorithm

abstract:
  We consider a network model where the nodes are grouped into a number of
clusters and propose a distributed dynamic frequency allocation algorithm that
achieves performance close to that of a centralized optimal algorithm. Each
cluster chooses its transmission frequency band based on its knowledge of the
interference that it experiences. The convergence of the proposed distributed
algorithm to a sub-optimal frequency allocation pattern is proved. For some
specific cases of spatial distributions of the clusters in the network,
asymptotic bounds on the performance of the algorithm are derived and
comparisons to the performance of optimal centralized solutions are made. These
analytic results and additional simulation studies verify performance close to
that of an optimum centralized frequency allocation algorithm. It is
demonstrated that the algorithm achieves about 90% of the Shannon capacities
corresponding to the optimum/near-optimum centralized frequency band
assignments. Furthermore, we consider the scenario where each cluster can be in
active or inactive mode according to a two-state Markov model. We derive
conditions to guarantee finite steady state variance for the output of the
algorithm using stochastic analysis. Further simulation studies confirm the
results of stochastic modeling and the performance of the algorithm in the
time-varying setup.


title: A Note on a Standard Embedding on Half-Flat Manifolds

abstract:
  It is argued that the ten dimensional solution that corresponds to the
compactification of $E_8 \times E_8$ heterotic string theory on a half-flat
manifold is the product space-time $R^{1,2} \times Z_7$ where $Z_7$ is a
generalized cylinder with $G_2$ riemannian holonomy. Standard embedding on
$Z_7$ then implies an embedding on the half-flat manifold which involves the
torsionful connection rather than the Levi-Civita connection. This leads to the
breakdown of $E_8 \times E_8$ to $E_6 \times E_8$, as in the case of the
standard embedding on Calabi-Yau manifolds, which agrees with the result
derived recently by Gurrieri, Lukas and Micu (arXiv:0709.1932) using a
different approach. Green-Schwarz anomaly cancellation is then implemented via
the torsionful connection on half-flat manifolds.


title:
The Effect of a Random Drift on Mixed and Pure Strategies in the
  Snowdrift Game

abstract:
  The replicator dynamics of players choosing either mixed or pure strategies
are usually regarded as equivalent, as long as strategies are played with
identical frequencies. In this paper we show that a population of pure
strategists can be invaded by mixed strategists in any two-player game with
equilibrium coexistence upon the addition of an arbitrarily small amount of
noise in the replication process.


title: Improved Fully Dynamic Reachability Algorithm for Directed Graph

abstract:
  We propose a fully dynamic algorithm for maintaining reachability information
in directed graphs. The proposed deterministic dynamic algorithm has an update
time of $O((ins*n^{2}) + (del * (m+n*log(n))))$ where $m$ is the current number
of edges, $n$ is the number of vertices in the graph, $ins$ is the number of
edge insertions and $del$ is the number of edge deletions. Each query can be
answered in O(1) time after each update. The proposed algorithm combines
existing fully dynamic reachability algorithm with well known witness counting
technique to improve efficiency of maintaining reachability information when
edges are deleted. The proposed algorithm improves by a factor of
$O(\frac{n^2}{m+n*log(n)})$ for edge deletion over the best existing fully
dynamic algorithm for maintaining reachability information.


title:
Limited Feedback-based Block Diagonalization for the MIMO Broadcast
  Channel

abstract:
  Block diagonalization is a linear precoding technique for the multiple
antenna broadcast (downlink) channel that involves transmission of multiple
data streams to each receiver such that no multi-user interference is
experienced at any of the receivers. This low-complexity scheme operates only a
few dB away from capacity but requires very accurate channel knowledge at the
transmitter. We consider a limited feedback system where each receiver knows
its channel perfectly, but the transmitter is only provided with a finite
number of channel feedback bits from each receiver. Using a random quantization
argument, we quantify the throughput loss due to imperfect channel knowledge as
a function of the feedback level. The quality of channel knowledge must improve
proportional to the SNR in order to prevent interference-limitations, and we
show that scaling the number of feedback bits linearly with the system SNR is
sufficient to maintain a bounded rate loss. Finally, we compare our
quantization strategy to an analog feedback scheme and show the superiority of
quantized feedback.


title: Study of B -> D** l nu with full reconstruction tagging

abstract:
  We report a study of semileptonic B decays to P-wave D** mesons. Semileptonic
decay to D*_2 meson is observed for the first time and its product branching
ratio is measured to be
  Br(B+ -> anti-D*0_2 l+nu) x Br(anti-D*0_2 -> D- pi+) = 0.22 +- 0.03(stat.) +-
0.04(syst.)%. The result is obtained using the fully reconstructed B tags from
a data sample that contains 657 millions BB-bar pairs collected at the
Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+
e- collider.


title:
The Effect of Sensory Blind Zones on Milling Behavior in a Dynamic
  Self-Propelled Particle Model

abstract:
  Emergent pattern formation in self-propelled particle (SPP) systems is
extensively studied because it addresses a range of swarming phenomena which
occur without leadership. Here we present a dynamic SPP model in which a
sensory blind zone is introduced into each particle's zone of interaction.
Using numerical simulations we discovered that the degradation of milling
patterns with increasing blind zone ranges undergoes two distinct transitions,
including a new, spatially nonhomogeneous transition that involves cessation of
particles' motion caused by broken symmetries in their interaction fields. Our
results also show the necessity of nearly complete panoramic sensory ability
for milling behavior to emerge in dynamic SPP models, suggesting a possible
relationship between collective behavior and sensory systems of biological
organisms.


title:
Restudy on Dark Matter Time-Evolution in the Littlest Higgs model with
  T-parity

abstract:
  Following previous study, in the Littlest Higgs model (LHM), the heavy photon
is supposed to be a possible dark matter candidate and its relic abundance of
the heavy photon is estimated in terms of the Boltzman-Lee-Weinberg
time-evolution equation. The effects of the T-parity violation is also
considered. Our calculations show that when Higgs mass $M_H$ taken to be 300
GeV and don't consider T-parity violation, only two narrow ranges
$133<M_{A_{H}}<135$ GeV and $167<M_{A_{H}}<169$ GeV are tolerable with the
current astrophysical observation and if $135<M_{A_{H}}<167$ GeV, there must at
least exist another species of heavy particle contributing to the cold dark
matter. As long as the T-parity can be violated, the heavy photon can decay
into regular standard model particles and would affect the dark matter
abundance in the universe, we discuss the constraint on the T-parity violation
parameter based on the present data. Direct detection prospects are also
discussed in some detail.


title: On the cluster multiplication theorem for acyclic cluster algebras

abstract:
  In \cite{CK2005} and \cite{Hubery2005}, the authors proved the cluster
multiplication theorems for finite type and affine type. We generalize their
results and prove the cluster multiplication theorem for arbitrary type by
using the properties of 2--Calabi--Yau
  (Auslander--Reiten formula) and high order associativity.


title:
In-situ observation of a soap film catenoid - a simple educational
  physics experiment

abstract:
  The solution to the Euler-Lagrange equation is an extremal functional.To
understand that the functional is stationary at local extrema (maxima or
minima), we propose a physics experiment that involves using soap film to form
a catenoid.
  A catenoid is a surface that is formed between two coaxial circular rings and
is classified mathematically as a minimal surface.Using soap film, we create
catenoids between two rings and characterize the catenoid in-situ while varying
distance between rings. The shape of the soap film is very interesting and can
be explained using dynamic mechanics. By observing catenoid, physics students
can observe local extrema phenomena.
  We stress that in-situ observation of soap film catenoids is an appropriate
physics experiment that combines theory and experimentation.

categories: physics.class-ph math-ph math.MP physics.ed-ph physics.pop-ph


title:
Depth profile photoemission study of thermally diffused Mn/GaAs (001)
  interfaces

abstract:
  We have performed a depth profile study of thermally diffused Mn/GaAs (001)
interfaces using photoemission spectroscopy combined with Ar$^+$-ion
sputtering. We found that Mn ion was thermally diffused into the deep region of
the GaAs substrate and completely reacted with GaAs. In the deep region, the Mn
2$p$ core-level and Mn 3$d$ valence-band spectra of the Mn/GaAs (001) sample
heated to 600 $^{\circ}$C were similar to those of Ga$_{1-x}$Mn$_x$As,
zinc-blende-type MnAs dots, and/or interstitial Mn in tetrahedrally coordinated
by As atoms, suggesting that the Mn 3$d$ states were essentially localized but
were hybridized with the electronic states of the host GaAs. Ferromagnetism was
observed in the dilute Mn phase.


title:
Singularities of solutions to Schrodinger equation on scattering
  manifold

abstract:
  In this paper we study microlocal singularities of solutions to Schrodinger
equations on scattering manifolds, i.e., noncompact Riemannian manifolds with
asymptotically conic ends. We characterize the wave front set of the solutions
in terms of the initial condition and the classical scattering maps under the
nontrapping condition. Our result is closely related to a recent work by
Hassell and Wunsch, though our model is more general and the method, which
relies heavily on scattering theoretical ideas, is simple and quite different.
In particular, we use Egorov-type argument in the standard pseudodifferential
symbol classes, and avoid using Legendre distributions. In the proof, we employ
a microlocal smoothing property in terms of the radially homogenous wave front
set, which is more precise than the preceding results.


title:
Dynamic nuclear polarization and Knight shift measurements in a
  breakdown regime of integer quantum Hall effect

abstract:
  Nuclear spins are polarized electrically in a breakdown regime of an
odd-integer quantum Hall effect (QHE). Electron excitation to the upper Landau
subband with the opposite spin polarity flips nuclear spins through the
hyperfine interaction. The polarized nuclear spins reduce the spin-splitting
energy and accelerate the QHE breakdown. The Knight shift of the nuclear spins
is also measured by tuning electron density during the irradiation of
radio-frequency magnetic fields.


title:
Bogoliubov Hamiltonian as Derivative of Dirac Hamiltonian via Braid
  Relation

abstract:
  In this paper we discuss a new type of 4-dimensional representation of the
braid group. The matrices of braid operations are constructed by q-deformation
of Hamiltonians. One is the Dirac Hamiltonian for free electron with mass m,
the other, which we find, is related to the Bogoliubov Hamiltonian for
quasiparticles in $^3$He-B with the same free energy and mass being m/2. In the
process, we choose the free q-deformation parameter as a special value in order
to be consistent with the anyon description for fractional quantum Hall effect
with $\nu = 1/2$.


title:
Mechanism of Slow Relaxation due to Screening Effect in a Frustrated
  System

abstract:
  We study a slow relaxation process in a frustrated spin system in which a
type of screening effect due to a frustrated environment plays an important
role. This screening effect is attributed to the highly degenerate
configurations of the frustrated environment. This slow relaxation is due to an
entropy effect and is different from those due to the energy barrier observed
in systems such as random ferromagnets. In the present system, even if there is
no energy gap, the slow relaxation still takes place. Thus, we call this
phenomenon ``entropic slowing down''. Here, we study the mechanism of entropic
slowing down quantitatively in an Ising spin model with the so-called decorated
bonds. The spins included in decorated bonds (decoration spins) cause a
peculiar density of states, which causes on entropy-induced screening effect.
We analytically estimate the time scale of the system that increases
exponentially with the number of decoration spins. We demonstrate the scaling
of relaxation processes using the time scale at all temperatures including the
critical point.


title: Harmonic analysis related to Schroedinger operators

abstract:
  In this article we give an overview on some recent development of
Littlewood-Paley theory for Schr\"odinger operators. We extend the
Littlewood-Paley theory for special potentials considered in the authors'
previous work. We elaborate our approach by considering potential in
$C^\infty_0$ or Schwartz class in one dimension. In particular the low energy
estimates are treated by establishing some new and refined asymptotics for the
eigenfunctions and their Fourier transforms. We give maximal function
characterization of the Besov spaces and Triebel-Lizorkin spaces associated
with $H$. Then we prove a spectral multiplier theorem on these spaces and
derive Strichartz estimates for the wave equation with a potential. We also
consider similar problem for the unbounded potentials in the Hermite and
Laguerre cases, whose potentials $V=a|x|^2+b|x|^{-2}$ are known to be critical
in the study of perturbation of nonlinear dispersive equations. This improves
upon the previous results when we apply the upper Gaussian bound for the heat
kernel and its gradient.


title: Preferential survival in models of complex ad hoc networks

abstract:
  There has been a rich interplay in recent years between (i) empirical
investigations of real world dynamic networks, (ii) analytical modeling of the
microscopic mechanisms that drive the emergence of such networks, and (iii)
harnessing of these mechanisms to either manipulate existing networks, or
engineer new networks for specific tasks. We continue in this vein, and study
the deletion phenomenon in the web by following two different sets of web-sites
(each comprising more than 150,000 pages) over a one-year period. Empirical
data show that there is a significant deletion component in the underlying web
networks, but the deletion process is not uniform. This motivates us to
introduce a new mechanism of preferential survival (PS), where nodes are
removed according to a degree-dependent deletion kernel. We use the mean-field
rate equation approach to study a general dynamic model driven by Preferential
Attachment (PA), Double PA (DPA), and a tunable PS, where c nodes (c<1) are
deleted per node added to the network, and verify our predictions via
large-scale simulations. One of our results shows that, unlike in the case of
uniform deletion, the PS kernel when coupled with the standard PA mechanism,
can lead to heavy-tailed power law networks even in the presence of extreme
turnover in the network. Moreover, a weak DPA mechanism, coupled with PS, can
help make the network even more heavy-tailed, especially in the limit when
deletion and insertion rates are almost equal, and the overall network growth
is minimal. The dynamics reported in this work can be used to design and
engineer stable ad hoc networks and explain the stability of the power law
exponents observed in real-world networks.


title:
The Focusing NLS Equation on the Half-Line with Periodic Boundary
  Conditions

abstract:
  We consider the Dirichlet problem for the focusing NLS equation on the
half-line, with given Schwartz initial data and boundary data $q(0,t)$ equal to
an exponentially decaying perturbation $u(t)$ of the periodic boundary data $ a
e^{2i\omega t + i \epsilon}$ at $x=0.$ It is known from PDE theory that this is
a well-posed problem (for fixed initial data and fixed $u$). On the other hand,
the associated inverse scattering transform formalism involves the Neumann
boundary value for $x=0$. Thus the implementation of this formalism requires
the understanding of the "Dirichlet-to-Neumann" map which characterises the
associated Neumann boundary value.
  We consider this map in an indirect way: we postulate a certain
Riemann-Hilbert problem and then prove that the solution of the
initial-boundary value problem for the focusing NLS constructed through this
Riemann-Hilbert problem satisfies all the required properties: the data
$q(x,0)$ are Schwartz and $q(0,t)-a e^{2i\omega t + i \epsilon}$ is
exponentially decaying.
  More specifically, we focus on the case $-3a^2 < \omega < a^2.$ By
considering a large class of appropriate scattering data for the t-problem, we
provide solutions of the above Dirichlet problem such that the data $q_x(0,t)$
is given by an exponentially decaying perturbation of the function $2iab
e^{2i\omega t + i \epsilon},$ where $\omega = a^2-2b^2,~~b>0$.


title: X-Ray Emission from Jet-Wind Interaction in Planetary Nebulae

abstract:
  We conduct 2D numerical simulations of jets expanding into the slow wind of
asymptotic giant branch stars. We show that the post-shock jets' material can
explain the observed extended X-ray emission from some planetary nebulae (PNs).
Such jets are thought to shape many PNs, and therefore it is expected that this
process will contribute to the X-ray emission from some PNs. In other PNs (not
simulated in this work) the source of the extended X-ray emission is the
shocked spherical wind blown by the central star. In a small fraction of PNs
both sources might contribute, and a two-temperatures gas will fit better the
X-ray properties than a one-temperature gas. A spacial separation between these
two components is expected.


title:
Umbral Fine Structures in Sunspots Observed with Hinode Solar Optical
  Telescope

abstract:
  High resolution imaging observation of a sunspot umbra was done with Hinode
Solar Optical Telescope (SOT). Filtergrams in wavelengths of blue and green
continuum were taken during three consecutive days. The umbra consisted of a
dark core region, several diffuse components and numerous umbral dots. We
derived basic properties of umbral dots (UDs), especially their temperatures,
lifetimes, proper motions, spatial distribution and morphological evolution.
Brightness of UDs is confirmed to depend on the brightness of their surrounding
background. Several UDs show fission and fusion. Thanks to the stable condition
of space observation, we could first follow the temporal behavior of these
events. The derived properties of internal structure of the umbra are discussed
in viewpoint of magnetoconvection in a strong magnetic field.


title:
Preparation and magnetoresistance of Ag 2+x Se thin films deposited via
  Pulsed Laser Deposition

abstract:
  The preparation of Ag 2+x Se thin films with thicknesses between 4 nm and
3000 nm by pulsed laser deposition on single crystalline NaCl and MgO
substrates is reported. The films are perfectly dense and show a good lateral
uniformity with a small number of defects. The microstructure of the films
corresponds to a nanoparquet, being composed of two different phases of silver
selenide. One phase is identified as the Naumannite low temperature phase of
silver selenide, the structure of the other phase has not been reported in
detail before and probably represents a metastable phase. Silver-rich films
contain silver precipitates with typical sizes on the nanoscale. Their presence
and their size appears to be responsible for the large and linear
magnetoresistance effect of silver-rich silver selenide.


title:
Nucleus-nucleus cross-sections and long-range correlations with a local
  supercritical pomeron

abstract:
  Nucleus-nucleus scattering is studied in the local Reggeon Field Theory in
the quasi-classical approximation with non-eikonal boundary conditions
corresponding to the Glauber picture at low energies. Comparison with the
commonly used eikonal boundary conditions shows that the new conditions make
both the action and nucleus-nucleus total cross-sections lower by $3\div 5$ %.
They also substantially change the behaviour of the solutions of the equations
of motion at low energies. Using expressions for the double inclusive
cross-sections derived earlier in the Reggeon Field Theory \cite{CM} long-range
rapidity correlations are calculated for the RHIC and LHC energies.


title:
An Improved Procedure for Selecting the Profiles of Perfectly Matched
  Layers

abstract:
  The perfectly matched layers (PMLs), as a boundary termination over an
unbounded spatial domain, are widely used in numerical simulations of wave
propagation problems. Given a set of discretization parameters, a procedure to
select the PML profiles based on minimizing the discrete reflectivity is
established for frequency domain simulations. We, by extending the function
class and adopting a direct search method, improve the former procedure for
traveling waves.


title: Observing Zitterbewegung in Ultracold Atoms

abstract:
  We propose an optical lattice scheme which would permit the experimental
observation of Zitterbewegung (ZB) with ultracold, neutral atoms. A four-level
"tripod" variant of the usual setup for stimulated Raman adiabatic passage
(STIRAP) has been proposed for generating non-Abelian gauge fields [1].
Dirac-like Hamiltonians, which exhibit ZB, are simple examples of such
non-Abelian gauge fields; we show how a variety of them can arise, and how ZB
can be observed, in a tripod system. We predict that the ZB should occur at
experimentally accessible frequencies and amplitudes.


title: Computer model validation with functional output

abstract:
  A key question in evaluation of computer models is Does the computer model
adequately represent reality? A six-step process for computer model validation
is set out in Bayarri et al. [Technometrics 49 (2007) 138--154] (and briefly
summarized below), based on comparison of computer model runs with field data
of the process being modeled. The methodology is particularly suited to
treating the major issues associated with the validation process: quantifying
multiple sources of error and uncertainty in computer models; combining
multiple sources of information; and being able to adapt to different, but
related scenarios. Two complications that frequently arise in practice are the
need to deal with highly irregular functional data and the need to acknowledge
and incorporate uncertainty in the inputs. We develop methodology to deal with
both complications. A key part of the approach utilizes a wavelet
representation of the functional data, applies a hierarchical version of the
scalar validation methodology to the wavelet coefficients, and transforms back,
to ultimately compare computer model output with field output. The generality
of the methodology is only limited by the capability of a combination of
computational tools and the appropriateness of decompositions of the sort
(wavelets) employed here. The methods and analyses we present are illustrated
with a test bed dynamic stress analysis for a particular engineering system.


title: Unparticles in Gluodynamics

abstract:
  The virtual effects of unparticle physics on the two-gluon jets production
are explored for CERN LHC. It is found that depending on the scale dimension,
unparticles can give rise to substantial enhancements in the transverse
momentum and pseudo-rapidity distributions of hadronic cross sections, up to a
factor of four-orders of magnitude.


title: Magnetogenesis, spectator fields and CMB signatures

abstract:
  A viable class of magnetogenesis models can be constructed by coupling the
kinetic term of the hypercharge to a spectator field whose dynamics does not
affect the inflationary evolution. The magnetic power spectrum is explicitly
related to the power spectrum of (adiabatic) curvature inhomogeneities when the
quasi-de Sitter stage of expansion is driven by a single scalar degree of
freedom. Depending upon the value of the slow-roll parameters, the amplitude of
smoothed magnetic fields over a (comoving) Mpc scale can be as large as
0.01--0.1 nG at the epoch of the gravitational collapse of the protogalaxy. The
contributions of the magnetic fields to the Sachs-Wolfe plateau and to the
temperature autocorrelations in the Doppler region compare favourably with the
constraints imposed by galactic magnetogenesis. Stimulating lessons are drawn
on the interplay between magnetogenesis models and their possible CMB
signatures.


title: Microsystem Product Development

abstract:
  Over the last decade the successful design and fabrication of complex MEMS
(MicroElectroMechanical Systems), optical circuits and ASICs have been
demonstrated. Packaging and integration processes have lagged behind MEMS
research but are rapidly maturing. As packaging processes evolve, a new
challenge presents itself, microsystem product development. Product development
entails the maturation of the design and all the processes needed to
successfully produce a product. Elements such as tooling design, fixtures,
gages, testers, inspection, work instructions, process planning, etc., are
often overlooked as MEMS engineers concentrate on design, fabrication and
packaging processes. Thorough, up-front planning of product development efforts
is crucial to the success of any project.


title: Parasitic Effects Reduction for Wafer-Level Packaging of RF-Mems

abstract:
  In RF-MEMS packaging, next to the protection of movable structures,
optimization of package electrical performance plays a very important role. In
this work, a wafer-level packaging process has been investigated and optimized
in order to minimize electrical parasitic effects. The RF-MEMS package concept
used is based on a wafer-level bonding of a capping silicon substrate to an
RF-MEMS wafer. The capping silicon substrate resistivity, substrate thickness
and the geometry of through-substrate electrical interconnect vias have been
optimized using finite-element electromagnetic simulations (Ansoft HFSS). Test
structures for electrical characterization have been designed and after their
fabrication, measurement results will be compared with simulations.


title:
Surface Conditioning Effect on Vacuum Microelectronics Components
  Fabricated by Deep Reactive Ion Etching

abstract:
  Advances in material processing such as silicon micromachining are opening
the way to vacuum microelectronics. Two-dimensional vacuum components can be
fabricated using the microsystems processes. We developed such devices using a
single metal layer and silicon micromachining by DRIE. The latter technological
step has significant impact on the characteristics of the vacuum components.
This paper presents a brief summary of electron emission possibilities and the
design leading to the fabrication of a lateral field emission diode. First
measurement results and the aging of the devices are also discussed.


title: 3-D Self-Assembled Soi Mems: An Example of Multiphysics Simulation

abstract:
  MEMS devices are typical systems where multiphysics simulations are
unavoidable. In this work, we present possible applications of 3-D
self-assembled SOI (Silicon-on-Insulator) MEMS such as, for instance, thermal
actuators and flow sensors. The numerical simulations of these microsystems are
presented. Structural and thermal parts have to be strongly coupled for
correctly describing the fabrication process and for simulating the behavior of
these 3-D SOI MEMS.


title: Electron-electron interaction in 2D and 1D ferromagnetic (Ga,Mn)As

abstract:
  We investigated the magnetotransport in high quality ferromagnetic (Ga,Mn)As
films and wires. At low temperature the conductivity decreases with decreasing
temperature without saturation down to 20 mK. Here we show, that the
conductivity decrease follows a ln($T/T_0$) dependency in 2D films and a
$-1/\sqrt{T}$ dependency in 1D wires and is independent of an applied magnetic
field. This behavior can be explained by the theory of electron-electron
interaction.


title:
Influence of the Feedback Filter on the Response of the Pulsed Digital
  Oscillator

abstract:
  This paper introduces a new feedback topology for the Pulsed Digital
Oscillator (PDO) and compares it to the classical topology. The `classic' or
single feedback topology, introduced in previous works, shows a strong behavior
dependence on the damping losses in the MEMS resonator. A new double feedback
topology is introduced here in order to help solving this problem. Comparative
discrete-time simulations and preliminary experimental measurements have been
carried out for both topologies, showing how the new double feedback topology
may increase PDO performance for some frequency ranges.


title: Chaotic behavior in the accretion disk

abstract:
  The eccentric luminosity variation of quasars is still a mystery. Analytic
results of this behavior ranged from multi-periodic behavior to a purely random
process. Recently, we have used nonlinear time-series analysis to analyze the
light curve of 3C 273 and found its eccentric behavior may be chaos [L. Liu,
Chin. J. Astron. Astrophys. \textbf{6}, 663 (2006)]. This result induces us to
look for some nonlinear mechanism to explain the eccentric luminosity
variation. In this paper, we propose a simple non-linear accretion disk model
and find it shows a kind of chaotic behavior under some circumstances. Then we
compute the outburst energy $\triangle F$, defined as the difference of the
maximum luminosity and the minimum luminosity, and the mean luminosity $<F>$.
We find that $\triangle F\sim < F >^{\alpha}$ in the chaotic domain, where
$\alpha\approx 1$. In this domain, we also find that $<F > \sim M^{0.5}$, where
$M$ is the mass of central black hole. These results are confirmed by or
compatible with some results from the observational data analysis [A. J. Pica
and A. G. Smith, Astrophys. J. \textbf{272}, 11 (1983); M. Wold, M. S.
Brotherton and Z. Shang, Mon. Not. R. Astron. Soc. \textbf{375}, 989 (2007)].


title: Relativistic Photon Mediated Shocks

abstract:
  A system of equations governing the structure of a steady, relativistic
radiation dominated shock is derived, starting from the general form of the
transfer equation obeyed by the photon distribution function. Closure is
obtained by truncating the system of moment equations at some order. The
anisotropy of the photon distribution function inside the shock is shown to
increase with increasing shock velocity, approaching nearly perfect beaming at
upstream Lorentz factors $\Gamma_{-}>>1$. Solutions of the shock equations are
presented for some range of upstream conditions. These solutions are shown to
converge as the truncation order is increased.


title: Study of Pure Annihilation Decays B_{d,s} \to D^{0} \bar D^{0}

abstract:
  With heavy quark limit and hierarchy approximation $\lambda_{QCD}\ll m_D\ll
m_B$, we analyze the $B\to D^0\bar D^0$ and $B_s\to D^0\bar D^0$ decays, which
occur purely via annihilation type diagrams. As a roughly estimation, we
calculate their branching ratios and CP asymmetries in Perturbative QCD
approach. The branching ratio of $B\to D^0\bar D^0$ is about $3.8\times10^{-5}$
that is just below the latest experimental upper limit. The branching ratio of
$B_s\to D^0\bar D^0$ is about $6.8\times10^{-4}$, which could be measured in
LHC-b. From the calculation, it could be found that this branching ratio is not
sensitive to the weak phase angle $\gamma$. In these two decay modes, there
exist CP asymmetries because of interference between weak and strong
interaction. However, these asymmetries are too small to be measured easily.


title: Modeling river delta formation

abstract:
  A new model to simulate the time evolution of river delta formation process
is presented. It is based on the continuity equation for water and sediment
flow and a phenomenological sedimentation/ erosion law. Different delta types
are reproduced using different parameters and erosion rules. The structures of
the calculated patterns are analyzed in space and time and compared with real
data patterns. Furthermore our model is capable to simulate the rich dynamics
related to the switching of the mouth of the river delta. The simulation
results are then compared with geological records for the Mississippi river.


title:
Concave Microlens Array Mold Fabrication in Photoresist Using UV
  Proximity Printing

abstract:
  This paper presents a simple and effective method to fabricate a
polydimethyl-siloxane (PDMS) microlens array with a high fill factor, which
utilizes the UV proximity printing and photoresist replication methods. The
concave microlens array mold was made using a printing gap in lithography
process, which utilizes optical diffraction of UV light to deflect away from
the aperture edges and produces a certain exposure in the photoresist material
outside the aperture edges. This method can precisely control the geometric
profile of concave microlens array. The experimental results showed that the
concave micro-lens array in photoresist could be formed automatically when the
printing gap ranged from 240 micron to 720 micron. High fill factor microlens
array can be produced, when the control pitch distance between the adjacent
apertures of the concave microlens array was decreased to the aperture size.


title: The Inhomogeneous Invariance Quantum Supergroup of Supersymmetry Algebra

abstract:
  We consider an inhomogeneous quantum supergroup which leaves invariant a
supersymmetric particle algebra. The quantum sub-supergroups of this
inhomogeneous quantum supergroup are investigated.


title:
The annealing induced extraordinary properties of SI based ZNO film
  grown by RF sputtering

abstract:
  Pb(Zr0.52Ti0.48)O3 (PZT) thin films were in situ deposited by pulsed laser
deposition (PLD) on Pt/Ti/SiO2/Si substrates using a template layer derived by
sol-gel method. A 0.1-$\mu$m-thick PZT layer with (111) or (100)-preferred
orientation was first deposited onto Pt/Ti/SiO2/Si substrates using the sol-gel
method, and than a PZT layer with thickness of 1$\mu$m was in situ deposited by
PLD on the above-mentioned PZT layer. The crystalline phases and the preferred
orientations of the PZT films were investigated by X-ray diffraction analysis.
Surface and cross-sectional morphologies were observed by scanning electron
microscopy and transmission electron microscopy. The electrical properties of
the films were evaluated by measuring their P-E hysteresis loops and dielectric
constants. The preferred orientation of the films can be controlled using the
template layer derived by the sol-gel method. The deposition temperature
required to obtain the perovskite phase in this process is approximately 460
degrees C, and is significantly lower than that in the case of direct film
deposition by PLD on the Pt/Ti/SiO2/Si substrates.
  Keywords: lead zirconate titanate (PZT), thin film, sol-gel method, laser
ablation, electrical properties


title: Parametric Yield Analysis of Mems via Statistical Methods

abstract:
  This paper considers a developing theory on the effects of inevitable process
variations during the fabrication of MEMS and other microsystems. The effects
on the performance and design yield of the microsystems devices are analyzed
and presented. A novel methodology in the design cycle of MEMS and other
microsystems is briefly introduced. This paper describes the initial steps of
this methodology that is aimed at counteracting the parametric variations in
the product cycle of microsystems. It is based on a concept of worst-case
analysis that has proven successful in the parent IC technology. Issues ranging
from the level of abstraction of the microsystem models to the availability of
such models are addressed


title:
Electrostatically-Driven Resonator on Soi with Improved Temperature
  Stability

abstract:
  This paper deals with a single-crystal-silicon (SCS) MEMS resonator with
improved temperature stability. While simulations have shown that the
temperature coefficient of resonant frequency can be down to 1 ppm/degrees C,
preliminary measurements on non-optimised structures gave evidence of a
temperature coefficient of 29 ppm/degrees C. Design, optimisation, experimental
results with post process simulation and prospective work are presented.


title:
Electromechanical Reliability Testing of Three-Axial Silicon Force
  Sensors

abstract:
  This paper reports on the systematic electromechanical characterization of a
new three-axial force sensor used in dimensional metrology of micro components.
The siliconbased sensor system consists of piezoresistive mechanicalstress
transducers integrated in thin membrane hinges supporting a suspended flexible
cross structure. The mechanical behavior of the fragile micromechanical
structure isanalyzed for both static and dynamic load cases. This work
demonstrates that the silicon microstructure withstands static forces of 1.16N
applied orthogonally to the front-side of the structure. A statistical Weibull
analysis of the measured data shows that these values are significantly reduced
if the normal force is applied to the back of the sensor. Improvements of the
sensor system design for future development cycles are derived from the
measurement results.


title:
An Active Chaotic Micromixer Integrating Thermal Actuation Associating
  PDMS and Silicon Microtechnology

abstract:
  Due to scaling laws, in microfluidic, flows are laminar. Consequently, mixing
between two liquids is mainly obtained by natural diffusion which may take a
long time or equivalently requires centimetre length channels. To reduce time
and length for mixing, it is possible to generate chaotic-like flows either by
modifying the channel geometry or by creating an external perturbation of the
flow. In this paper, an active micromixer is presented consisting on thermal
actuation with heating resistors. In order to disturb the liquid flow, an
oscillating transverse flow is generated by heating the liquid. Depending on
the value of boiling point, either bubble expansion or volumetric dilation
controlled the transverse flow amplitude. A chaotic like mixing is then induced
under particular conditions depending on volume expansion, liquid velocity,
frequency of actuation... This solution presents the advantage to achieve
mixing in a very short time (1s) and along a short channel distance (channel
width). It can also be integrated in a more complex device due to actuator
integration with microfluidics.


title:
Resolution Limits for Resonant Mems Sensors Based on Discrete Relay
  Feedback Techniques

abstract:
  This paper is devoted to the analysis of resonant MEMS sensors based on
discrete relay feedback techniques. One drawback of such techniques is that
some synchronization usually occurs between the discrete part and the
continuous part of the system: this results in sensor responses that are very
similar to the curves known as devil's staircases, i.e. the frequency does not
vary smoothly with the sensor's input. The main contribution of this paper is a
theoretical calculation of the resolution of such systems. The resolutions of
two existing resonant MEMS architectures are then calculated and these results
are discussed.


title: A Silicon-Based Micro Gas Turbine Engine for Power Generation

abstract:
  This paper reports on our research in developing a micro power generation
system based on gas turbine engine and piezoelectric converter. The micro gas
turbine engine consists of a micro combustor, a turbine and a centrifugal
compressor. Comprehensive simulation has been implemented to optimal the
component design. We have successfully demonstrated a silicon-based micro
combustor, which consists of seven layers of silicon structures. A
hairpin-shaped design is applied to the fuel/air recirculation channel. The
micro combustor can sustain a stable combustion with an exit temperature as
high as 1600 K. We have also successfully developed a micro turbine device,
which is equipped with enhanced micro air-bearings and driven by compressed
air. A rotation speed of 15,000 rpm has been demonstrated during lab test. In
this paper, we will introduce our research results major in the development of
micro combustor and micro turbine test device.


title:
The dog-and-rabbit chase problem as an exercise in introductory
  kinematics

abstract:
  The purpose of this article is to present a simple solution of the classic
dog-and-rabbit chase problem which emphasizes the use of concepts of elementary
kinematics and, therefore, can be used in introductory mechanics course. The
article is based on the teaching experience of introductory mechanics course at
Novosibirsk State University for first year physics students which are just
beginning to use advanced mathematical methods in physics problems. We hope it
will be also useful for students and teachers at other universities too.


title: Energy Conversion Using New Thermoelectric Generator

abstract:
  During recent years, microelectronics helped to develop complex and varied
technologies. It appears that many of these technologies can be applied
successfully to realize Seebeck micro generators: photolithography and
deposition methods allow to elaborate thin thermoelectric structures at the
micro-scale level. Our goal is to scavenge energy by developing a miniature
power source for operating electronic components. First Bi and Sb micro-devices
on silicon glass substrate have been manufactured with an area of 1cm2
including more than one hundred junctions. Each step of process fabrication has
been optimized: photolithography, deposition process, anneals conditions and
metallic connections. Different device structures have been realized with
different micro-line dimensions. Each devices performance will be reviewed and
discussed in function of their design structure.


title: On Order, Disorder and Coherence

abstract:
  We provide a brief survey of quantum statistical characterisations of order,
disorder and coherence in systems of many degrees of freedom. Here, order and
coherence are described in terms of symmetry breakdown, while disorder is
described in terms of entropy and algorithmic complexity, whose interconnection
has been recently extended from the classical to the quantum domain. We see
that, in the present physical context, the concepts of order and disorder are
not mutually antithetical, but bear an interrelationship similar to that
between signals and noise.

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


title: Above Ic Micro-Power Generators for RF-Mems

abstract:
  This work presents recent advances in the development and the integration of
an electrochemical (chemicalelectrical energy conversion) micro power generator
used as a high voltage energy source for RF-MEMS powering. Autonomous MEMS
require similarly miniaturized power sources. Up to day, solid state thin film
batteries are realized with mechanical masks. This method doesn't allow
dimensions below a few mm^2 active area, and besides the whole process flow is
done under controlled atmosphere so as to ensure materials chemical stability
(mainly lithiated materials). Within this context, Microelectronics
micro-fabrication procedures (photolithography, Reactive Ion Etching...) are
used to reach both miniaturisation (100x100 $\mu$m^2 targeted unit cell active
area) and Above IC technological compatibility. All process steps developed
here are realized in clean room environment.


title: Packaging of RF Mems Switching Functions on Alumina Substrate

abstract:
  Recently the strong demands in wireless communication requires expanding
development for the application of RF MEMS (Radio Frequency micro electro
mechanical systems) sensing devices such as micro-switches, tunable capacitors
because it offers lower power consumption, lower losses, higher linearity and
higher Q factors compared with conventional communications components. To
accelerate commercialisation of RF MEMS products, development for packaging
technologies is one of the most critical issues should be solved beforehand.


title: Recent Developments in Mems-Based Micro Fuel Cells

abstract:
  Micro fuel cells ($\mu$-FC) represent promising power sources for portable
applications. Today, one of the technological ways to make $\mu$-FC is to have
recourse to standard microfabrication techniques used in the fabrication of
micro electromechanical systems (MEMS). This paper shows an overview on the
applications of MEMS techniques on miniature FC by presenting several solutions
developed throughout the world. It also describes the latest developments of a
new porous silicon-based miniature fuel cell. Using a silane grafted on an
inorganic porous media as the proton-exchange membrane instead of a common
ionomer such as Nafion, the fuel cell achieved a maximum power density of 58 mW
cm-2 at room temperature with hydrogen as fuel.


title: Influence of Micro-Cantilever Geometry and Gap on Pull-in Voltage

abstract:
  In this paper, we study the behaviour of a microcantilever beam under
electrostatic actuation using finite difference method. This problem has a lot
of applications in MEMS based devices like accelerometers, switches and others.
In this paper, we formulated the problem of a cantilever beam with proof mass
at its end and carried out the finite difference solution. we studied the
effects of length, width, and the gap size on the pull-in voltage using data
that are available in the literature. Also, the stability limit is compared
with the single degree of freedom commonly used in the earlier literature as an
approximation to calculate the pull-in voltage.


title:
Design and Development of Novel Electroplating Spring Frame Mems
  Structure Specimens for the Microtensile Testing of Thin Film Materials

abstract:
  Microelectromechanical systems (MEMS) technologies are developing rapidly
with increasing study of the design, fabrication and commercialization of
microscale systems and devices. Accurate mechanical properties are important
for successful design and development of MEMS. We have demonstrated here a
novel electroplating spring frame MEMS Structure Specimen integrates pin-pin
align holes, misalignment compensate spring structure frame, load sensor beam
and freestanding thin film. The specimen can be fit into a specially designed
microtensile apparatus which is capable of carrying out a series of tests on
sub-micro scale freestanding thin films.


title:
Characterisation of the Etching Quality in Micro-Electro-Mechanical
  Systems by Thermal Transient Methodology

abstract:
  Our paper presents a non-destructive thermal transient measurement method
that is able to reveal differences even in the micron size range of MEMS
structures. Devices of the same design can have differences in their
sacrificial layers as consequence of the differences in their manufacturing
processes e.g. different etching times. We have made simulations examining how
the etching quality reflects in the thermal behaviour of devices. These
simulations predicted change in the thermal behaviour of MEMS structures having
differences in their sacrificial layers. The theory was tested with
measurements of similar MEMS devices prepared with different etching times. In
the measurements we used the T3Ster thermal transient tester equipment. The
results show that deviations in the devices, as consequence of the different
etching times, result in different temperature elevations and manifest also as
shift in time in the relevant temperature transient curves.


title:
The Effects of Additives on the Physical Properties of Electroformed
  Nickel and on the Stretch of Photoelectroformed Nickel Components

abstract:
  The process of nickel electroforming is becoming increasingly important in
the manufacture of MST products, as it has the potential to replicate complex
geometries with extremely high fidelity. Electroforming of nickel uses
multi-component electrolyte formulations in order to maximise desirable product
properties. In addition to nickel sulphamate (the major electrolyte component),
formulation additives can also comprise nickel chloride (to increase nickel
anode dissolution), sulphamic acid (to control pH), boric acid (to act as a pH
buffer), hardening/levelling agents (to increase deposit hardness and lustre)
and wetting agents (to aid surface wetting and thus prevent gas bubbles and
void formation). This paper investigates the effects of some of these variables
on internal stress and stretch as a function of applied current density.


title: Expectations for dihadron correlation measurements at the LHC

abstract:
  The suppression of high transverse momentum (P_T) inclusive hadron spectra in
heavy-ion collisions as compared to the scaled expectation of high P_T hadron
production in p-p collisions is the most direct manifestation of the
interaction of hard partons with the soft bulk medium produced in heavy-ion
collisions which is absent in p-p collisions. Yet the measured nuclear
suppression factor R_AA is a very averaged quantity and hence only a limited
amount of information about the medium evolution and the nature of the
interaction with the medium can be deduced from R_AA. Measurements of hard
back-to-back hadron correlations in 200 AGeV Au-Au collisions at RHIC have
opened a new window to study the energy loss of partons in a medium in a more
differential way and for a different distribution of in-medium pathlengths than
in the case of R_AA. In this work, we present an extrapolation of our results
for back-to-back yields at RHIC energies to 5.5 TeV Pb-Pb collisions at the
CERN LHC. We also discuss differences and similarities between the measurement
at RHIC.


title:
A Novel Contact Resistance Model of Anisotropic Conductive Film for FPD
  Packaging

abstract:
  In this research, a novel contact resistance model for the flat panel display
(FPD) packaging based on the within layer parallel and between layers series
resistance concepts was proposed. The FJ2530 anisotropic conductive films (ACF)
by Sony Inc. containing the currently smallest 3micron conductive particles was
used to conduct the experiments to verify the accuracy of the proposed model.
Calculated resistance of the chip-on-glass (COG) packaging by the proposed
model is 0.163\Omega. It is found that the gold bump with 0.162\Omega
resistance play the major role of the overall resistance. Although the
predicted resistance by the proposed model is only one third of the
experimentally measured value, it has been three-fold improvement compared to
the existing models.


title:
Measurement Technique for Elastic and Mechanical Properties of
  Polycrystalline Silicon-Germanium Films Using Surface Acoustic Waves and
  Projection Masks

abstract:
  Using Rayleigh surface acoustic waves (SAW), the Young's modulus, the density
and the thickness of polycrystalline Silicon-Germanium (SiGe) films deposited
on silicon and SiO2 were measured, in excellent agreement with theory. The
dispersion curve of the propagating SAW is calculated with a Boundary Element
Method (BEM)-Model based on Green's functions. The propagating SAW is generated
with a nanosecond laser in a narrowband scheme projecting stripes from a mask
on the surface of the sample. For this purpose a glass mask and a liquid
crystal display (LCD) mask are used. The slope of the SAW is then measured
using a probe beam setup. From the wavelength of the mask and the frequency of
the measured SAW, the dispersion curve is determined point by point. Fitting
the BEM-Model to the measured nonlinear dispersion curve provides several
physical parameters simultaneously. In the present work this is demonstrated
for the Young's modulus, the density and the thickness of SiGe films. The
results from the narrowband scheme measurement are in excellent agreement with
separated measurements of the thickness (profilometer), the density (balance)
and the Young's modulus (nanoindenter).