title:
Rigorous Bounds on the Performance of a Hybrid Dynamical
  Decoupling-Quantum Computing Scheme

abstract:
  We study dynamical decoupling in a multi-qubit setting, where it is combined
with quantum logic gates. This is illustrated in terms of computation using
Heisenberg interactions only, where global decoupling pulses commute with the
computation. We derive a rigorous error bound on the trace distance or fidelity
between the desired computational state and the actual time-evolved state, for
a system subject to coupling to a bounded-strength bath. The bound is expressed
in terms of the operator norm of the effective Hamiltonian generating the
evolution in the presence of decoupling and logic operations. We apply the
bound to the case of periodic pulse sequences and find that in order maintain a
constant trace distance or fidelity, the number of cycles -- at fixed pulse
interval and width -- scales in inverse proportion to the square of the number
of qubits. This sets a scalability limit on the protection of quantum
computation using periodic dynamical decoupling.


title: How good is the Warnsdorff's knight's tour heuristic?

abstract:
  Warnsdorffs rule for a knights tour is a heuristic, i.e., it is a rule that
does not produce the desired result all the time. It is a classic example of a
greedy method in that it is based on a series of locally optimal choices. This
note describes an analysis that determines how good the heuristic is on an 8 X
8 chessboard. The order of appearance in a permutation of the eight possible
moves a knight can make determines the path the knight takes. A computer
analysis is done of the 8! permutations of the order of a knights moves in
Warnsdorffs rule on an 8 X 8 chessboard for tours starting on each of the 64
squares. Whenever a tie occurs for moves to vertices that have the lowest
degree, the first of these vertices encountered in the programming loop is
chosen. The number of permutations of the 8! total that yield non-Hamiltonian
paths is tallied. This will be the same value if we consistently choose the
last of these vertices encountered.


title:
On approximating the distributions of goodness-of-fit test statistics
  based on the empirical distribution function: The case of unknown parameters

abstract:
  This paper discusses some problems possibly arising when approximating via
Monte-Carlo simulations the distributions of goodness-of-fit test statistics
based on the empirical distribution function. We argue that failing to
re-estimate unknown parameters on each simulated Monte-Carlo sample -- and thus
avoiding to employ this information to build the test statistic -- may lead to
wrong, overly-conservative testing. Furthermore, we present a simple example
suggesting that the impact of this possible mistake may turn out to be dramatic
and does not vanish as the sample size increases.


title: The S-matrix of String Bound States

abstract:
  We find the S-matrix which describes the scattering of two-particle bound
states of the light-cone string sigma model on AdS5xS5. We realize the
M-particle bound state representation of the centrally extended su(2|2) algebra
on the space of homogeneous (super)symmetric polynomials of degree M depending
on two bosonic and two fermionic variables. The scattering matrix S^{MN} of M-
and N-particle bound states is a differential operator of degree M+N acting on
the product of the corresponding polynomials. We require this operator to obey
the invariance condition and the Yang-Baxter equation, and we determine it for
the two cases M=1,N=2 and M=N=2. We show that the S-matrices found satisfy
generalized physical unitarity, CPT invariance, parity transformation rule and
crossing symmetry. Although the dressing factor as a function of four
parameters x_1^+,x_1^-,x_2^+,x_2^- is universal for scattering of any bound
states, it obeys a crossing symmetry equation which depends on M and N.


title: Recent Developments in Gravitational Microlensing

abstract:
  Twenty-one years after Bohdan's seminal paper launched the field of
gravitational microlensing, it has radically diversified from a method narrowly
focused on finding dark matter to a very general astronomical tool.
Microlensing has now detected 12 planets, including several that are
inaccessible by other search methods. It has resolved the surfaces of distant
stars, served as a magnifying glass to take spectra of extremely faint objects,
and revealed a number of surprising phenomena. I take a sweeping look at this
remarkable technique, giving equal weight to its successes and to the tensions
that are continuing to propel it forward.


title: Dynamical noncommutativity and Noether theorem in twisted phi^*4 theory

abstract:
  A \star-product is defined via a set of commuting vector fields X_a = e_a^\mu
(x) \partial_\mu, and used in a phi^*4 theory coupled to the e_a^\mu (x)
fields. The \star-product is dynamical, and the vacuum solution phi =0, e_a^\mu
(x)=delta_a^\mu reproduces the usual Moyal product. The action is invariant
under rigid translations and Lorentz rotations, and the conserved
energy-momentum and angular momentum tensors are explicitly derived.


title: The Onsager equation for corpora

abstract:
  We consider extensions of excluded volume interactions for complex corpora
that generalize simple rod-like particles. The Onsager equation can be defined
for quite general configuration spaces, and the dimension reduction of the
phase space in the limit of highly intense interaction can be shown. The
formalism describes both freely articulated and interacting N-rods and the
example of interacting 2-rods is given in detail.


title: Some theorems in gravitational and electromagnetic fields

abstract:
  The paper discusses the influences of velocity curl and field strength on
some theorems in the electromagnetic field and gravitational field. With the
characteristics of the algebra of quaternions, the theorem of linear momentum,
conservation of linear momentum, and conservation of angular momentum etc. can
be deduced from the quaternionic definitions of physical quantities. And the
strength of gravitational field and electromagnetic field have an influence on
some theorems directly. While the velocity curl has an effect on some theorems
also.


title: Angle integrated photoemission study of SmO$_{0.85}$F$_{0.15}$FeAs

abstract:
  The electronic structure of the new superconductor, SmO$_{1-x}$F$_x$FeAs
($x=0.15$), has been studied by angle-integrated photoemission spectroscopy.
Our data show a sharp feature very close to the Fermi energy, and a relative
flat distribution of the density of states between 0.5 eV and 3 eV binding
energy, which agrees best with band structure calculations considering an
antiferromagnetic ground state. No noticeable gap opening was observed at 12
Kelvin below the superconducting transition temperature, indicating the
existence of large ungapped regions in the Brillouin zone.


title: Metabelian SL(n,C) representations of knot groups

abstract:
  We give a classification of irreducible metabelian representations from a
knot group into SL(n,C) and GL(n,C). If the homology of the n-fold branched
cover of the knot is finite, we show that every irreducible metabelian SL(n,C)
representation is conjugate to a unitary representation and that the set of
conjugacy classes of such representations is finite. In that case, we give a
formula for this number in terms of the Alexander polynomial of the knot. These
results are the higher rank generalizations of a result of Nagasato, who
recently studied irreducible, metabelian SL(2,C) representations of knot
groups. Finally we deduce the existence irreducible metabelian SL(n,C)
representations of the knot group for any knot with nontrivial Alexander
polynomial.


title: Rare Decays with a Light CP-Odd Higgs Boson in the NMSSM

abstract:
  We have previously proposed a light pseudoscalar Higgs boson in the
next-to-minimal supersymmetric standard model (NMSSM), the A_1^0, as a
candidate to explain the HyperCP observations in Sigma^+ -> p mu^+ mu^-. In
this paper we calculate the rates for several other rare decay modes that can
help confirm or refute this hypothesis. The first modes we evaluate are K_L ->
pi pi A_1^0, which are interesting because they are under study by the KTeV
Collaboration. We next turn to eta -> pi pi A_1^0, which are interesting
because they are independent of the details of the flavor-changing sector of
the NMSSM and may be accessible at DAPhNE. For completeness, we also evaluate
Omega^- -> Xi^- A_1^0.


title:
A Quartic Conformally Covariant Differential Operator for Arbitrary
  Pseudo-Riemannian Manifolds (Summary)

abstract:
  This is the original manuscript dated March 9th 1983, typeset by the Editors
for the Proceedings of the Midwest Geometry Conference 2007 held in memory of
Thomas Branson. Stephen Paneitz passed away on September 1st 1983 while
attending a conference in Clausthal and the manuscript was never published. For
more than 20 years these few pages were circulated informally. In November
2004, as a service to the mathematical community, Tom Branson added a scan of
the manuscript to his website. Here we make it available more formally. It is
surely one of the most cited unpublished articles. The differential operator
defined in this article plays a key role in conformal differential geometry in
dimension 4 and is now known as the Paneitz operator.


title: On Sequential Estimation and Prediction for Discrete Time Series

abstract:
  The problem of extracting as much information as possible from a sequence of
observations of a stationary stochastic process $X_0,X_1,...X_n$ has been
considered by many authors from different points of view. It has long been
known through the work of D. Bailey that no universal estimator for
$\textbf{P}(X_{n+1}|X_0,X_1,...X_n)$ can be found which converges to the true
estimator almost surely. Despite this result, for restricted classes of
processes, or for sequences of estimators along stopping times, universal
estimators can be found. We present here a survey of some of the recent work
that has been done along these lines.


title:
One-loop corrections to the instanton transition in the Abelian Higgs
  model: Gel'fand-Yaglom and Green's function methods

abstract:
  The fluctuation determinant, the preexponential factor for the instanton
transition, has been computed several years ago in the Abelian Higgs model,
using a method based on integrating the Euclidean Green' function. A more
elegant method for computing functional determinants, using the Gel'fand-Yaglom
theorem, has been applied recently to a variety of systems. This method runs
into difficulties if the background field has nontrivial topology, as is the
case for the instanton in the Abelian Higgs model. A shift in thre effective
centrifugal barriers makes the s-wave contribution infinite, an infinity that
is compensated by the summation over the other partial waves. This requires
some modifications of the Gel'fand-Yaglom method which are the main subject of
this work. We present here both, the Green' s function and the Gel'fand-Yaglom
method and compare the numerical results in detail.


title: Real and complex zeros of Riemannian random waves

abstract:
  We consider Riemannian random waves, i.e. Gaussian random linear combination
of eigenfunctions of the Laplacian on a compact Riemannian manifold with
frequencies from a short interval (`asymptotically fixed frequency'). We first
show that the expected limit distribution of the real zero set of a is uniform
with respect to the volume form of a compact Riemannian manifold $(M, g)$. We
then show that the complex zero set of the analytic continuations of such
Riemannian random waves to a Grauert tube in the complexification of $M$ tends
to a limit current.


title: The Universe as an Inside-Out Star

abstract:
  Acoustic modes can be used to study the physics of the interior of a cavity,
and this is especially useful when the inside region is inaccessible. Many
astrophysicists use such sound waves as an essential tool in their research.
Here we focus on two separate sub-fields in which oscillations on the surface
of a sphere are studied -- Helioseismology and CMBology -- the surface being
either the solar or cosmic photosphere. Both research areas use the language of
spherical harmonics, as well as sharing many close similarities in the
underlying physics. However, there are also many fundamental differences, which
we explain in this pedagogical article.


title: Products and Factors of Banach function spaces

abstract:
  Given two Banach function spaces we study the pointwise product space E.F,
especially for the case that the pointwise product of their unit balls is again
convex. We then give conditions on when the pointwise product E . M(E, F)=F,
where M(E,F) denotes the space of multiplication operators from E into F.


title: Quantum mechanics not on manifold

abstract:
  The free scalar field is studied on the Y-junction of three semi infinite
axes which is the simplest example of a non-manifold space. It is shown that
under an assumption that the junction point can not gain a macroscopic amount
of energy and charge the transmission rules for this system uniquely follow
from conservation of energy and charge. This result is also obtained in the
discrete version of the model. Some alternative approaches to the problem based
on quantum mechanics of Hamiltonian systems with constrains are discussed.


title: Commutators of contactomorphisms

abstract:
  The group of volume preserving diffeomorphisms, the group of
symplectomorphisms and the group of contactomorphisms constitute the classical
groups of diffeomorphisms. The first homology groups of the compactly supported
identity components of the first two groups have been computed by Thurston and
Banyaga, respectively. In this paper we solve the long standing problem on the
algebraic structure of the third classical diffeomorphism group, i.e. the
contactomorphism group. Namely we show that the compactly supported identity
component of the group of contactomorphisms is perfect and simple (if the
underlying manifold is connected). The result could be applied in various ways.


title:
Twisted SUSY Invariant Formulation of Chern-Simons Gauge Theory on a
  Lattice

abstract:
  We propose a twisted SUSY invariant formulation of Chern-Simons theory on a
Euclidean three dimensional lattice. The SUSY algebra to be realized on the
lattice is the N=4 D=3 twisted algebra that was recently proposed by D'Adda et
al.. In order to keep the manifest anti-hermiticity of the action, we introduce
oppositely oriented supercharges. Accordingly, the naive continuum limit of the
action formally corresponds to the Landau gauge fixed version of Chern-Simons
theory with complex gauge group which was originally proposed by Witten. We
also show that the resulting action consists of parity even and odd parts with
different coefficients.

categories: hep-lat cond-mat.mes-hall cond-mat.str-el hep-th


title:
Possible Indications of New Physics in Bd-mixing and in sin(2 beta)
  Determinations

abstract:
  Using the hadronic matrix elements from the lattice, B_K and xi_s, involving
only the 4-quark operators for Delta flavor (F) = 2 Hamiltonian relevant for K,
B_d and B_s mixing, along with V_cb, we deduce a non-trivial constraint on the
SM, sin (2 beta) = 0.87+-0.09. This deviates from direct experimental
measurements via the tree process, b -> c c s as well as the one via the
penguin-loop b -> s decays by around 2.1 and 2.7 sigma respectively. If these
deviations are confirmed they would imply the presence of new physics rather
pervasively in both B_d mixing (i.e. very likely in b -> d) as well as in b ->
s transitions requiring a beyond the SM CP-odd phase. Consequently,
improvements in the relevant lattice calculations should be given a high
priority.


title: Dissecting Massive YSOs with Mid-Infrared Interferometry

abstract:
  The very inner structure of massive YSOs is difficult to trace. With
conventional observational methods we often identify structures still several
hundreds of AU in size. But we also need information about the innermost
regions where the actual mass transfer onto the forming high-mass star occurs.
An innovative way to probe these scales is to utilise mid-infrared
interferometry. Here, we present first results of our MIDI GTO programme at the
VLTI. We observed 10 well-known massive YSOs down to scales of 20 mas. We
clearly resolve these objects which results in low visibilities and sizes in
the order of 30 - 50 mas. Thus, with MIDI we can for the first time quantify
the extent of the thermal emission from the warm circumstellar dust and thus
calibrate existing concepts regarding the compactness of such emission in the
pre-UCHII region phase. Special emphasis will be given to the BN-type object
M8E-IR where our modelling is most advanced and where there is indirect
evidence for a strongly bloated central star.


title: Locally constant functors

abstract:
  We study locally constant coefficients. We first study the theory of homotopy
Kan extensions with locally constant coefficients in model categories, and
explain how it characterizes the homotopy theory of small categories. We
explain how to interpret this in terms of left Bousfield localization of
categories of diagrams with values in a combinatorial model category. At last,
we explain how the theory of homotopy Kan extensions in derivators can be used
to understand locally constant functors.


title: The ART of Cosmological Simulations

abstract:
  We describe the basic ideas of MPI parallelization of the N-body Adaptive
Refinement Tree (ART) code. The code uses self-adaptive domain decomposition
where boundaries of the domains (parallelepipeds) constantly move -- with many
degrees of freedom -- in the search of the minimum of CPU time. The actual CPU
time spent by each MPI task on previous time-step is used to adjust boundaries
for the next time-step. For a typical decomposition of 5^3 domains, the number
of possible changes in boundaries is 3^{84}. We describe two algorithms of
finding minimum of CPU time for configurations with a large number of domains.
Each MPI task in our code solves the N-body problem where the large-scale
distribution of matter outside of the boundaries of a domain is represented by
relatively few temporary large particles created by other domains. At the
beginning of a zero-level time-step, domains create and exchange large
particles. Then each domain advances all its particles for many small
time-steps. At the end of the large step, the domains decide where to place new
boundaries and re-distribute particles. The scheme requires little
communications between processors and is very efficient for large cosmological
simulations.


title:
On the sampling and recovery of bandlimited functions via scattered
  translates of the Gaussian

abstract:
  Let $\lambda$ be a positive number, and let $(x_j:j\in\mathbb
Z)\subset\mathbb R$ be a fixed Riesz-basis sequence, namely, $(x_j)$ is
strictly increasing, and the set of functions $\{\mathbb R\ni t\mapsto
e^{ix_jt}:j\in\mathbb Z\}$ is a Riesz basis ({\it i.e.,} unconditionalbasis)
for $L_2[-\pi,\pi]$. Given a function $f\in L_2(\mathbb R)$ whose Fourier
transform is zero almost everywhere outside the interval $[-\pi,\pi]$, there is
a unique square-summable sequence $(a_j:j\in\mathbb Z)$, depending on $\lambda$
and $f$, such that the function$$I_\lambda(f)(x):=\sum_{j\in\mathbb
Z}a_je^{-\lambda(x-x_j)^2}, \qquad x\in\mathbb R, $$ is continuous and square
integrable on $(-\infty,\infty)$, and satisfies the interpolatory conditions
$I_\lambda (f)(x_j)=f(x_j)$, $j\in\mathbb Z$. It is shown that $I_\lambda(f)$
converges to $f$ in $L_2(\mathbb R)$, and also uniformly on $\mathbb R$, as
$\lambda\to0^+$. A multidimensional version of this result is also obtained. In
addition, the fundamental functions for the univariate interpolation process
are defined, and some of their basic properties, including their exponential
decay for large argument, are established. It is further shown that the
associated interpolation operators are bounded on $\ell_p(\mathbb Z)$ for every
$p\in[1,\infty]$.


title: Ultraluminous X-ray Sources: Beambags and Optical Counterparts

abstract:
  A significant fraction of ultraluminous X-ray sources appear to be embedded
in observable ionized nebulae that take the form of large, several 100 pc
diameter interstellar bubbles. Here we review optical observations of these
bubbles, their importance for our understanding of the nature of ULXs, the
energetics involved and their formation and evolution. Among the results
obtained are new arguments against conventional superbubble scenarios and
hypernova remnants, and we present the case in favour of ULX-wind/jet driven
bubbles. We report the discovery of new ULXs in very large SNR candidates in
nearby galaxies, and finally present an image of a triple X-ray source
coincident with the radio-bright bubble S26 in the galaxy NGC 7793 which
appears to be a clone of the microquasar SS433/W50 system.


title:
A Generic Two-band Model for Unconventional Superconductivity and
  Spin-Density-Wave Order in Electron and Hole Doped Iron-Based Superconductors

abstract:
  Based on experimental data on the newly synthesized iron-based
superconductors and the relevant band structure calculations, we propose a
minimal two-band BCS-type Hamiltonian with the interband Hubbard interaction
included. We illustrate that this two-band model is able to capture the
essential features of unconventional superconductivity and spin density wave
(SDW) ordering in this family of materials. It is found that bound
electron-hole pairs can be condensed to reveal the SDW ordering for zero and
very small doping, while the superconducting ordering emerges at small finite
doping, whose pairing symmetry is qualitatively analyzed to be of nodal d-wave.
The derived analytical formulas not only give out a nearly symmetric phase
diagram for electron and hole doping, but also is likely able to account for
existing main experimental results. Moreover, we also derive two important
relations for a general two-band model and elaborate how to apply them to
determine the band width ratio and the effective interband coupling strength
from experimental data.


title:
Multiband-Driven Superfluid-Insulator Transition of Fermionic Atoms in
  Optical Lattices: A Dynamical Mean-Field-Theory Study

abstract:
  The superfluid-insulator transitions of the fermionic atoms in optical
lattices are investigated by the two-site dynamical mean-field theory. It is
shown that the Mott transition occurs as a result of the multiband effects. The
quasiparticle weight in the superfluid state decreases significantly, as the
system approaches the Mott transition point. By changing the interaction and
the orbital splitting, we obtain the phase diagram at half filling. The
numerical results are discussed in comparison with the effective boson model.


title: Birational automorphisms of nodal quartic threefolds

abstract:
  It is well-known that a nonsingular minimal cubic surface is birationally
rigid; the group of its birational selfmaps is generated by biregular selfmaps
and birational involutions such that all relations between the latter are
implied by standard relations between reflections on an elliptic curve. It is
also known that a factorial nodal quartic threefold is birationally rigid and
its group of birational selfmaps is generated by biregular ones and certain
birational involutions. We prove that all relations between these involutions
are implied by standard relations on elliptic curves, complete the proof of
birational rigidity over a non-closed field and describe the situations when
some of the birational involutions in question become regular (and, in
particular, complete the proof of the initial theorem on birational rigidity,
since some details were not established in the original paper of M.Mella).


title: The identity type weak factorisation system

abstract:
  We show that the classifying category C(T) of a dependent type theory T with
axioms for identity types admits a non-trivial weak factorisation system. We
provide an explicit characterisation of the elements of both the left class and
the right class of the weak factorisation system. This characterisation is
applied to relate identity types and the homotopy theory of groupoids.


title: Generating Forms for Exact Volume-Preserving Maps

abstract:
  We study the group of volume-preserving diffeomorphisms on a manifold. We
develop a general theory of implicit generating forms. Our results generalize
the classical formulas for generating functions of symplectic twist maps.


title: Quantum Fields on the Groenewold-Moyal Plane

abstract:
  We give an introductory review of quantum physics on the noncommutative
spacetime called the Groenewold-Moyal plane. Basic ideas like star products,
twisted statistics, second quantized fields and discrete symmetries are
discussed. We also outline some of the recent developments in these fields and
mention where one can search for experimental signals.


title:
Experimental observation of oscillating and interacting matter wave dark
  solitons

abstract:
  We report on the generation, subsequent oscillation and interaction of a pair
of matter wave dark solitons. These are created by releasing a Bose-Einstein
condensate from a double well potential into a harmonic trap in the crossover
regime between one dimension (1D) and three dimensions (3D). The oscillation of
the solitons is observed and the frequency is in quantitative agreement with
simulations using the Gross-Pitaevskii equation. An effective particle picture
is developed and reveals that the deviation of the observed frequencies from
the asymptotic prediction $\nu_{z}/\sqrt{2}$, where $\nu_{z}$ is the
longitudinal trapping frequency, results from the dimensionality of the system
and the interaction between the solitons.


title: Polarization dependence of radiowave propagation through Antarctic ice

abstract:
  Using a bistatic radar system on the ice surface, we have studied
radiofrequency reflections off internal layers in Antarctic ice at the South
Pole. In our measurement, the total propagation time of ~ns-duration,
vertically broadcast radio signals, as a function of polarization axis in the
horizontal plane, provides a direct probe of the geometry-dependence of the ice
permittivity to depths of 1--2 km. Previous studies in East Antarctica have
interpreted the measured azimuthal dependence of reflected signals as evidence
for birefringent-induced interference effects, which are proposed to result
from preferred alignment of the crystal orientation fabric (COF) axis. To the
extent that COF alignment results from the bulk flow of ice across the
Antarctic continent, we would expect a measurable birefringent asymmetry at
South Pole, as well. Although we also observe clear dependence of reflected
amplitude on polarization angle in our measurements, we do not observe direct
evidence for birefringent-induced time-delay effects at the level of 0.1 parts
per mille.


title:
A O(n^8) X O(n^7) Linear Programming Model of the Traveling Salesman
  Problem

abstract:
  In this paper, we present a new linear programming (LP) formulation of the
Traveling Salesman Problem (TSP). The proposed model has O(n^8) variables and
O(n^7) constraints, where n is the number of cities. Our numerical
experimentation shows that computational times for the proposed linear program
are several orders of magnitude smaller than those for the existing model [3].


title: Grammar-Based Random Walkers in Semantic Networks

abstract:
  Semantic networks qualify the meaning of an edge relating any two vertices.
Determining which vertices are most "central" in a semantic network is
difficult because one relationship type may be deemed subjectively more
important than another. For this reason, research into semantic network metrics
has focused primarily on context-based rankings (i.e. user prescribed
contexts). Moreover, many of the current semantic network metrics rank semantic
associations (i.e. directed paths between two vertices) and not the vertices
themselves. This article presents a framework for calculating semantically
meaningful primary eigenvector-based metrics such as eigenvector centrality and
PageRank in semantic networks using a modified version of the random walker
model of Markov chain analysis. Random walkers, in the context of this article,
are constrained by a grammar, where the grammar is a user defined data
structure that determines the meaning of the final vertex ranking. The ideas in
this article are presented within the context of the Resource Description
Framework (RDF) of the Semantic Web initiative.


title:
Stochastic Dynamical Structure (SDS) of Nonequilibrium Processes in the
  Absence of Detailed Balance. II: construction of SDS with nonlinear force and
  multiplicative noise

abstract:
  There is a whole range of emergent phenomena in non-equilibrium behaviors can
be well described by a set of stochastic differential equations. Inspired by an
insight gained during our study of robustness and stability in phage lambda
genetic switch in modern biology, we found that there exists a classification
of generic nonequilibrium processes: In the continuous description in terms of
stochastic differential equations, there exists four dynamical elements: the
potential function $\phi$, the friction matrix $ S$, the anti-symmetric matrix
$ T $, and the noise. The generic feature of absence of detailed balance is
then precisely represented by $T$. For dynamical near a fixed point, whether or
not it is stable or not, the stochastic dynamics is linear. A rather complete
analysis has been carried out (Kwon, Ao, Thouless, cond-mat/0506280; PNAS, {\bf
102} (2005) 13029), referred to as SDS I. One important and persistent question
is the existence of a potential function with nonlinear force and with
multiplicative noise, with both nice local dynamical and global steady state
properties. Here we demonstrate that a dynamical structure built into
stochastic differential equation allows us to construct such a global
optimization potential function. First, we provide the construction. One of
most important ingredient is the generalized Einstein relation. We then present
an approximation scheme: The gradient expansion which turns every order into
linear matrix equations. The consistent of such methodology with other known
stochastic treatments will be discussed in next paper, SDS III; and the
explicitly connection to statistical mechanics and thermodynamics will be
discussed in a forthcoming paper, SDS IV.

categories: cond-mat.other astro-ph math-ph math.DS math.MP nlin.AO physics.bio-ph q-bio.PE q-bio.SC


title: Paradoxical popups: Why are they hard to catch?

abstract:
  Even professional baseball players occasionally find it difficult to
gracefully approach seemingly routine pop-ups. This paper describes a set of
towering pop-ups with trajectories that exhibit cusps and loops near the apex.
For a normal fly ball, the horizontal velocity is continuously decreasing due
to drag caused by air resistance. But for pop-ups, the Magnus force (the force
due to the ball spinning in a moving airflow) is larger than the drag force. In
these cases the horizontal velocity decreases in the beginning, like a normal
fly ball, but after the apex, the Magnus force accelerates the horizontal
motion. We refer to this class of pop-ups as paradoxical because they appear to
misinform the typically robust optical control strategies used by fielders and
lead to systematic vacillation in running paths, especially when a trajectory
terminates near the fielder. In short, some of the dancing around when
infielders pursue pop-ups can be well explained as a combination of bizarre
trajectories and misguidance by the normally reliable optical control strategy,
rather than apparent fielder error. Former major league infielders confirm that
our model agrees with their experiences.


title: Description of Multipole in f-Electron Systems

abstract:
  A systematic description of multipole degrees of freedom is discussed on the
basis of the Stevens' operator-equivalent technique. The generalized Stevens'
multiplicative factors are derived for all of the electric and the magnetic
multipoles relevant to f-electron systems. With extensive use of the Stevens'
factors, we express the spatial dependences of the electric and the magnetic
fields, and the electric and the magnetic charge densities of localized f
electrons. The latter is utilized to draw wave functions including their
magnetic profile in addition to their shape with the charge density. The
definite relation between the operators as quantum-mechanical variables in a
multipole exchange model and the multipole moments in expansion of
electromagnetic fields is given. The general treatments for the exchange model
with the RPA susceptibility and the Ginzburg-Landau free-energy expansion are
discussed, using CexLa1-xB6 as a typical example. The representative formula of
the vector spherical harmonics are summarized, which are suitable basis for
vector fields in the spherical expansion.


title: Lithium-rich giants in the Sagittarius dSph Tidal Streams

abstract:
  The nature and origin of Lithium rich giant stars is still matter of debate.
In the contest of our spectroscopic survey of giants in the tidal streams of
the Sagittarius dwarf spheroidal (dSph) galaxy, we present the serendipitous
discovery of 2 super Li-rich stars (A(Li)$>$3.5-4.0). Besides D461 in Draco,
these are the only Li-rich stars known in a Local Group dSph galaxy. The high
Li abundance and the low mass of these stars support their origin as due to
fresh Li production in the stars associated with some kind of extra-mixing
process.


title:
BCS-BEC crossover in a relativistic boson-fermion model beyond mean
  field approximation

abstract:
  We investigate the fluctuation effect of the di-fermion field in the
crossover from Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein
condensate (BEC) in a relativistic superfluid. We work within the boson-fermion
model obeying a global U(1) symmetry. To go beyond the mean field approximation
we use Cornwall-Jackiw-Tomboulis (CJT) formalism to include higher order
contributions. The quantum fluctuations of the pairing condensate is provided
by bosons in non-zero modes, whose interaction with fermions gives the
two-particle-irreducible (2PI) effective potential. It changes the crossover
property in the BEC regime. With the fluctuations the superfluid phase
transition becomes the first order in grand canonical ensemble. We calculate
the condensate, the critical temperature $T_{c}$ and particle abundances as
functions of crossover parameter the boson mass.


title: Spectral conditions on Lie and Jordan algebras of compact operators

abstract:
  We investigate the properties of bounded operators which satisfy a certain
spectral additivity condition, and use our results to study Lie and Jordan
algebras of compact operators. We prove that these algebras have nontrivial
invariant subspaces when their elements have sublinear or submultiplicative
spectrum, and when they satisfy simple trace conditions. In certain cases we
show that these conditions imply that the algebra is (simultaneously)
triangularizable.


title: Quark-meson coupling model with the cloudy bag

abstract:
  Using the volume coupling version of the cloudy bag model, the quark-meson
coupling model is extended to study the role of pion field and the properties
of nuclear matter. The extended model includes the effect of gluon exchange as
well as the pion-cloud effect, and provides a good description of the nuclear
matter properties. The relationship between the extended model and the EFT
approach to nuclear matter is also discussed.


title:
1/f spectrum and memory function analysis of solvation dynamics in a
  room-temperature ionic liquid

abstract:
  To understand the non-exponential relaxation associated with solvation
dynamics in the ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate,
we study power spectra of the fluctuating Franck-Condon energy gap of a
diatomic probe solute via molecular dynamics simulations. Results show 1/f
dependence in a wide frequency range over 2 to 3 decades, indicating
distributed relaxation times. We analyze the memory function and solvation time
in the framework of the generalized Langevin equation using a simple model
description for the power spectrum. It is found that the crossover frequency
toward the white noise plateau is directly related to the time scale for the
memory function and thus the solvation time. Specifically, the low crossover
frequency observed in the ionic liquid leads to a slowly-decaying tail in its
memory function and long solvation time. By contrast, acetonitrile
characterized by a high crossover frequency and (near) absence of 1/f behavior
in its power spectra shows fast relaxation of the memory function and
single-exponential decay of solvation dynamics in the long-time regime.


title:
Decoherence and relaxation of qubits coupled to low- and
  medium-frequency Ohmic baths directly and via a harmonic oscillator

abstract:
  Using the numerical path integral method we investigate the decoherence and
relaxation of qubits in spin-boson (SB) and spin-intermediate harmonic
oscillator (IHO)-bath (SIB) models. The cases that the environment baths with
low and medium frequencies are investigated. It is shown that the qubits in SB
and SIB models have the same decoherence and relaxation as the baths with low
frequencies. However, the qubits in the two models have different decoherence
and relaxation as the baths with medium frequencies. The decoherence and
relaxation of the qubit in SIB model can be modulated through changing the
coupling coefficients of the qubit-IHO and IHO-bath and the oscillation
frequency of the IHO.


title: Decoherence and purity of a driven solid-state qubit in Ohmic bath

abstract:
  In this paper we study the decoherence and purity of a driven solid-state
qubit in the Ohmic bath by using the method based on the master equation. At
first, instead of solving the master equation we investigate the coefficients
of the equation which describe the shift in frequency, diffusive, decoherence,
and so on. It is shown that one of the coefficients (we called it decoherence
coefficient) is crucial to the decoherence of the qubit in the model. Then we
investigate the evolution of the purity of the state in the model. From the
analysis of the purity we see that the decoherence time of the qubit decrease
with the increase of the amplitude of the driven fields and it is increase with
the increase of the frequency of the driven fields.


title: Variational formulation of Eisenhart's unified theory

abstract:
  Eisenhart's classical unified field theory is based on a non-Riemannian
affine connection related to the covariant derivative of the electromagnetic
field tensor. The sourceless field equations of this theory arise from
vanishing of the torsion trace and the symmetrized Ricci tensor. We formulate
Eisenhart's theory from the metric-affine variational principle. In this
formulation, a Lagrange multiplier constraining the torsion becomes the source
for the Maxwell equations.


title:
A new mathematical model for molecular dynamics 1: Molecular basis of
  memory

abstract:
  Proteins have been empirically linked to memory. If memory relates to protein
structure, then each conformation would_functionally_ code only one bit, making
it difficult to explain large memories. Nor is there a simple way to relate
memory to protein dynamics on current molecular dynamics (MD), which is
memoryless. Here we point out that MD may be modified to involve memory ab
initio without any new hypothesis: simply replace the electrostatic (Coulomb)
force by the electrodynamic force--which is more accurate. We now need to solve
functional differential equations (FDEs), instead of the ordinary differential
equations (ODEs) currently solved in MD. Unlike ODEs, retarded FDEs are
history-dependent: so memory is already present even at the level of
interacting sites within molecules. The resulting increase in computational
complexity is within the reach of current computers. While Amdahl's law does
pose a challenge to parallelised time-stepping with this model, the
compute-intensive part--the force calculation--may still be carried out in
parallel. Thus, reformulating MD to use FDEs is feasible, and this could help
to understand the possible dynamical basis of memory.


abstract:
  In this paper, using connections between Clifford-Wolf isometries and Killing
vector fields of constant length on a given Riemannian manifold, we classify
simply connected Clifford-Wolf homogeneous Riemannian manifolds. We also get
the classification of complete simply connected Riemannian manifolds with the
Killing property defined and studied previously by J.E. D'Atri and H.K.
Nickerson. In the last part of the paper we study properties of
Clifford-Killing spaces, that is, real vector spaces of Killing vector fields
of constant length, on odd-dimensional round spheres, and discuss numerous
connections between these spaces and various classical objects.


title:
Jacobi stability of the vacuum in the static spherically symmetric brane
  world models

abstract:
  We analyze the stability of the structure equations of the vacuum in the
brane world models, by using both the linear (Lyapunov) stability analysis, and
the Jacobi stability analysis, the Kosambi-Cartan-Chern (KCC) theory. In the
brane world models the four dimensional effective Einstein equations acquire
extra terms, called dark radiation and dark pressure, respectively, which arise
from the embedding of the 3-brane in the bulk. Generally, the spherically
symmetric vacuum solutions of the brane gravitational field equations, have
properties quite distinct as compared to the standard black hole solutions of
general relativity. We close the structure equations by assuming a simple
linear equation of state for the dark pressure. In this case the vacuum is
Jacobi stable only for a small range of values of the proportionality constant
relating the dark pressure and the dark radiation. The unstable trajectories on
the brane behave chaotically, in the sense that after a finite radial distance
it would be impossible to distinguish the trajectories that were very near each
other at an initial point. Hence the Jacobi stability analysis offers a
powerful method for constraining the physical properties of the vacuum on the
brane.


title: GRID Architecture through a Public Cluster

abstract:
  An architecture to enable some blocks consisting of several nodes in a public
cluster connected to different grid collaborations is introduced. It is
realized by inserting a web-service in addition to the standard Globus Toolkit.
The new web-service performs two main tasks : authenticate the digital
certificate contained in an incoming requests and forward it to the designated
block. The appropriate block is mapped with the username of the block's owner
contained in the digital certificate. It is argued that this algorithm opens an
opportunity for any blocks in a public cluster to join various global grids.


title:
Problems in the derivations of the renormalization group equation for
  the low momentum nucleon interactions

abstract:
  We carefully examine all the four derivations of the renormalization group
equation (RGE) for the so-called $\Vlk$ potential, given by Bogner, \textit{et.
al.}[nucl-th/0111042]. Two derivations based on the ``semi-group composition
law'' are shown to be unjustified, while the other two based on the
completeness relation of the model space must be modified if there are bound
states. It is however shown that the RGE is unchanged if the bound state
wavefunctions in the reduced theory are required to have the same low-momentum
components as those in the original theory. Several aspects of the $\Vlk$
approach are also discussed.


title: Global Compton heating and cooling in hot accretion flows

abstract:
  The hot accretion flow is usually optically thin in the radial direction,
therefore the photons produced at one radius can travel for a long distance
without being absorbed. These photons thus can heat or cool electrons at other
radii via Compton scattering. This effect has been ignored in most previous
works on hot accretion flows and is the focus of this paper. If the mass
accretion rate is described by $\dot{M}=\dot{M}_0(r/r_{\rm out})^{0.3}$ and
$r_{\rm out}=10^4r_{\rm s}$, we find that the Compton scattering will play a
cooling and heating role at $r\la 5\times 10^3 r_{\rm s}$ and $r\ga 5\times
10^3 r_{\rm s}$, respectively. Specifically, when $\dot{M}_0>0.1L_{\rm
Edd}/c^2$, the Compton cooling rate is larger than the local viscous heating
rate at certain radius; therefore the cooling effect is important. When
$\dot{M}_0>2L_{\rm Edd}/c^2$, the heating effect at $r_{\rm out}$ is important.
We can obtain the self-consistent steady solution with the global Compton
effect included only if $\dot{M}_0\la L_{\rm Edd}/c^2$ for $r_{\rm
out}=50r_{\rm s}$, which corresponds to $L\la 0.02L_{\rm Edd}$. Above this rate
the Compton cooling is so strong at the inner region that hot solutions can not
exist. On the other hand, for $r_{\rm out}= 10^5r_{\rm s}$, we can only get the
self-consistent solution when $\dot{M}_0\la L_{\rm Edd}/c^2$ and $L<0.01L_{\rm
Edd}$. Above this accretion rate the equilibrium temperature of electrons at
$r_{\rm out}$ is higher than the virial temperature as a result of strong
Compton heating, so the accretion is suppressed. In this case the activity of
the black hole will likely "oscillate" between an active and an inactive
phases, with the oscillation timescale being the radiative timescale of the gas
at $r_{\rm out}$.


title: The quantum moment problem and bounds on entangled multi-prover games

abstract:
  We study the quantum moment problem: Given a conditional probability
distribution together with some polynomial constraints, does there exist a
quantum state rho and a collection of measurement operators such that (i) the
probability of obtaining a particular outcome when a particular measurement is
performed on rho is specified by the conditional probability distribution, and
(ii) the measurement operators satisfy the constraints. For example, the
constraints might specify that some measurement operators must commute.
  We show that if an instance of the quantum moment problem is unsatisfiable,
then there exists a certificate of a particular form proving this. Our proof is
based on a recent result in algebraic geometry, the noncommutative
Positivstellensatz of Helton and McCullough [Trans. Amer. Math. Soc.,
356(9):3721, 2004].
  A special case of the quantum moment problem is to compute the value of
one-round multi-prover games with entangled provers. Under the conjecture that
the provers need only share states in finite-dimensional Hilbert spaces, we
prove that a hierarchy of semidefinite programs similar to the one given by
Navascues, Pironio and Acin [Phys. Rev. Lett., 98:010401, 2007] converges to
the entangled value of the game. It follows that the class of languages
recognized by a multi-prover interactive proof system where the provers share
entanglement is recursive.


title: Transfer maps and nonexistence of joint determinant

abstract:
  Transfer Maps, sometimes called norm maps, for Milnor's $K$-theory were first
defined by Bass and Tate (1972) for simple extensions of fields via tame symbol
and Weil's reciprocity law, but their functoriality had not been settled until
Kato (1980). On the other hand, functorial transfer maps for the Goodwillie
group are easily defined. We show that these natural transfer maps actually
agree with the classical but difficult transfer maps by Bass and Tate. With
this result, we build an isomorphism from the Goodwillie groups to Milnor's
$K$-groups of fields, which in turn provides a description of joint
determinants for the commuting invertible matrices. In particular, we
explicitly determine certain joint determinants for the commuting invertible
matrices over a finite field, the field of rational numbers, real numbers and
complex numbers into the respective group of units of given field.


title: Electric Mean Squared Radii of Lambda(1405) in Chiral Dynamics

abstract:
  The electric mean squared radii <r^2>_E of Lambda(1405) are calculated in the
chiral unitary model. We describe the Lambda(1405) as a dynamically generated
resonance fully in the octet meson and octet baryon scattering. We also
consider ``Lambda(1405)'' as a bound state of KbarN. For the later
``Lambda(1405),'' we obtain negative and larger absolute value of electric mean
squared radius than that of ordinary baryons, which implies that Lambda(1405)
have structure of widely spread K^- around p.


title:
A Group-Theoretical Method for Natanzon Potentials in Position-Dependent
  Mass Background

abstract:
  A new manner for deriving the exact potentials is presented. By making use of
conformal mappings, the general expression of the effective potentials deduced
under su(1,1) algebra can be brought back to the general Natanzon
hypergeometric potentials.


title: Is the Heisenberg uncertainty relation really violated?

abstract:
  It has been pointed out that for some types of measurement the Heisenberg
uncertainty relation seems to be violated. In order to save the situation a new
uncertainty relation was proposed by Ozawa. Here we introduce revised
definitions of error and disturbance taking into account the gain associated
with generalized measurement interactions. With these new definitions, the
validity of the Heisenberg inequality is recovered for continuous linear
measurement interactions. We also examine the changes in distribution functions
caused by the general measurement interaction and clarify the physical meanings
of infinitely large errors and disturbances.


title: Down-sizing Forever

abstract:
  Evidence for cosmic down-sizing has been growing over the last decade. It is
now clear that the major star-forming epoch for the largest galaxies occurred
earlier than for smaller galaxies. This not only runs counter to the popular
hierarchical clustering picture, but points to an even more radical revision of
our ideas of the evolution of cosmological structure. Galaxies do not form at
all.


title:
Effects of Isotope Substitution on Local Heating and Inelastic current
  in Hydrogen Molecular Junctions

abstract:
  Using first principle approaches, we investigate the effects of isotope
substitution on the inelastic features in the hydrogen molecular junction. We
observe thatlocal heating and inelastic current have significant
isotope-substitution effects. Due to the contact characters, the energies of
excited molecular vibrationsare inverse proportional to the square root of the
mass. The heavier the molecule, the smaller the onset bias. In the $H_{2}$ and
$D_{2}$ junctions, the heavier molecule has a smaller magnitude of
electron-vibration interaction. Consequently, there is a crossing in the local
temperature around $80 K$. In the HD junction, the electron-vibration
interaction is enhanced by asymmetric distribution in mass. It leads to the
largest discontinuity in the differential conductance and the most prominent
heating in the HD junction. We predict that the junction instability is
relevant to isotope substitution. The HD junction has the smallest breakdown
voltage compared with the $H_{2}$ and $D_{2}$ junction.


title:
Dynamical Rearrangement of Theta Parameter in Presence of Mixed
  Chern-Simons Term

abstract:
  We study the five-dimensional SU(3)_c x U(1)_C gauge theory on the orbifold
S^1/Z_2 with a mixed Chern-Simons term. We particularly pay attention to the
realization of the dynamical rearrangement of the theta parameter for SU(3)_c.
It is shown that the physics remains invariant under a large gauge
transformation which even changes the action, completely removing the theta
parameter, because of the Hosotani mechanism for the U(1)_C gauge interactions.
In other words, we show that the theta parameter can be regarded as a boundary
condition for the orbifolding in light of the dynamical rearrangement.


title: Regularity of monoids under Schutzenberger products

abstract:
  In this paper we give a partial answer to the problem which is about the
regularity of Schutzenberger products in semigroups asked by Gallagher in his
thesis [Problem 6.1.6]{Gallagher} and, also, we investigate the regularity for
the new version of the Schutzenberger product which was defined in [Ates].


title:
The Kostant form of $\mathfrak{U}(sl_n^+)$ and the Borel subalgebra of
  the Schur algebra S(n,r)

abstract:
  Let $A_n(K)$ be the Kostant form of $\mathfrak{U}(sl_n^+)$ and $\Gamma$ the
monoid generated by the positive roots of $sl_n$. For each $\lambda\in
\Lambda(n,r)$ we construct a functor $F_{\lambda}$ from the category of
finitely generated $\Gamma$-graded $A_n(K)$-modules to the category of finite
dimensional $S^+(n,r)$-modules, with the property that $F_{\lambda}$ maps
(minimal) projective resolutions of the one-dimensional $A_n(K)$-module $K_{A}$
to (minimal) projective resolutions of the simple $S^+(n,r)$-module
$K_{\lambda}$.


title: Discrete Approximation of Quantum Stochastic Models

abstract:
  We develop a general technique for proving convergence of repeated quantum
interactions to the solution of a quantum stochastic differential equation. The
wide applicability of the method is illustrated in a variety of examples. Our
main theorem, which is based on the Trotter-Kato theorem, is not restricted to
a specific noise model and does not require boundedness of the limit
coefficients.


title:
Element substitution effect in transition metal oxypnictide
  Re(O$_{1-x}$F$_x$)TAs (Re=rare earth, T=transition metal)

abstract:
  Different element substitution effects in transition metal oxypnictide
Re(O$_{1-x}$F$_x$)TAs with Re=La, Ce, Nd, Eu, Gd, Tm, T=Fe, Ni, Ru, were
studied. Similar to the La- or Ce-based systems, we found that the pure NdOFeAs
shows a strong resistivity anomaly near 145 K, which was ascribed to the
spin-density-wave instability. Electron doping by F increases T$_c$ to about 50
K. While in the case of Gd, the T$_c$ is reduced below 10 K. The tetragonal
ZrCuSiAs-type structure could not be formed for Eu or Tm substitution in our
preparing process. For Ni-based case, although both pure and F-doped LaONiAs
are superconducting, no superconductivity was found when La was replaced by Ce
in both cases, instead a ferromagnetic ordering transition was likely to form
at low temperature in F-doped sample. We also synthesized LaO$_{1-x}$F$_x$RuAs
and CeO$_{1-x}$F$_x$RuAs compounds. Metallic behavior was observed down to 4 K.


title:
Three-dimensional correlated-fermion phase separation from analysis of
  the geometric mean of the individual susceptibilities

abstract:
  A quasi-Gaussian approximation scheme is formulated to study the strongly
correlated imbalanced fermions thermodynamics, where the mean-field theory is
not applicable. The non-Gaussian correlation effects are understood to be
captured by the statistical geometric mean of the individual susceptibilities.
In the three-dimensional unitary fermions ground state, an {\em universal}
non-linear scaling transformation relates the physical chemical potentials with
the individual Fermi kinetic energies. For the partial polarization phase
separation to full polarization, the calculated critical polarization ratio is
$P_C={[1-(1-\xi)^{6/5}]}/{[1+(1-\xi)^{6/5}]}\doteq 0.34$. The $\xi=4/9$ defines
the ratio of the symmetric ground state energy density to that of the ideal
fermion gas.


title:
Solution to a combinatorial puzzle arising from Mayer's theory of
  cluster integrals

abstract:
  Mayer's theory of cluster integrals allows one to write the partition
function of a gas model as a generating function of weighted graphs. Recently,
Labelle, Leroux and Ducharme have studied the graph weights arising from the
one-dimensional hard-core gas model and noticed that the sum of the weights
over all connected graphs with $n$ vertices is $(-n)^{n-1}$. This is, up to
sign, the number of rooted Cayley trees on $n$ vertices and the authors asked
for a combinatorial explanation. The main goal of this article is to provide
such an explanation.


title: Are Neutrinos Majorana Particles?

abstract:
  This is an elementary account of neutrinos as Majarona particles and the
search for neutrinoless double beta decays. It also includes some more ideas
about neutrinos.


title: A Symmetric Algorithm for Hyperharmonic and Fibonacci Numbers

abstract:
  In this work, we introduce a symmetric algorithm obtained by the recurrence
relation a_{n}^{k}=a_{n-1}^{k}+a_{n}^{k-1}. We point out that this algorithm
can be apply to hyperharmonic-, ordinary and incomplete Fibonacci- and Lucas
numbers. An explicit formulae for hyperharmonic numbers, general generating
functions of the Fibonacci- and Lucas numbers are obtained. Besides we define
"hyperfibonacci numbers", "hyperlucas numbers". Using these new concepts, some
relations between ordinary and incomplete Fibonacci- and Lucas numbers are
investigated.


title: On the image of code polynomials under theta map

abstract:
  The theta map sends code polynomials into the ring of Siegel modular forms of
even weights. Explicit description of the image is known for $g\leq 3$ and the
surjectivity of the theta map follows. Instead it is known that this map is not
surjective for $g\geq 5$. In this paper we discuss the possibility of an
embedding between the associated projective varieties. We prove that this is
not possible for $g\geq 4$ and consequently we get the non surjectivity of the
graded rings for the remaining case $g=4$.


title:
Note About Redefinition of BRST Operator for Pure Spinor String in
  General Background

abstract:
  We discuss an analysis presented by N. Berkovits in [arXiv:0712.0324] in the
context of classical mechanics and perform its extension to the case of pure
spinor string in general background.


title:
A Hubble & Spitzer Space Telescope Survey for Gravitationally-Lensed
  Galaxies: Further Evidence for a Significant Population of Low Luminosity
  Galaxies beyond Redshift Seven

abstract:
  We present the results of a systematic search for gravitationally-lensed
continuum Lyman break `drop-outs' beyond a redshift 7 conducted via very deep
imaging through six foreground clusters undertaken with the Hubble and Spitzer
Space Telescopes. The survey has yielded 10 z-band and 2 J-band drop-out
candidates to photometric limits of J_110~=26.2 AB (5sigma). Taking into
account the magnifications afforded by our clusters (1-4 magnitudes), we probe
the presence of z>7 sources to unlensed limits of J_{110}~=30 AB, fainter than
those charted in the Hubble Ultradeep Field. To verify the fidelity of our
candidates we conduct a number of tests for instrumental effects which would
lead to spurious detections, and carefully evaluate the likelihood of
foreground contamination by considering photometric uncertainties in the
drop-out signature, the upper limits from stacked IRAC data and the statistics
of multiply-imaged sources. Overall, we conclude that we can expect about half
of our sample of z-band drop-outs are likely to be at high redshift. An
ambitious infrared spectroscopic campaign undertaken with the NIRSPEC
spectrograph at the WM Keck Observatory for seven of the most promising
candidates failed to detect any Lyman-alpha emission highlighting the challenge
of making further progress in this field. While the volume density of high
redshift sources will likely remain uncertain until more powerful facilities
are available, our data provides the first potentially interesting constraints
on the UV luminosity function at z~=7.5 at intrinsically faint limits. We
discuss the implications of our results in the context of the hypothesis that
the bulk of the reionizing photons in the era 7<z<12 arise in low luminosity
galaxies undetected by conventional surveys.


title: On Riemann sums and maximal functions in $\ZR^n$

abstract:
  In this paper we investigate problems on almost everywhere convergence of
subsequences of Riemann sums \md0
R_nf(x)=\frac{1}{n}\sum_{k=0}^{n-1}f\bigg(x+\frac{k}{n}\bigg),\quad x\in \ZT.
\emd We establish a relevant connection between Riemann and ordinary maximal
functions, which allows to use techniques and results of the theory of
differentiations of integrals in $\ZR^n$ in mentioned problems. In particular,
we prove that for a definite sequence of infinite dimension $n_k$ Riemann sums
$R_{n_k}f(x)$ converge almost everywhere for any $f\in L^p$ with $p>1$.


title:
Limit to mass sensitivity of nanoresonators with random rough surfaces
  due to intrinsic sources and interactions with the surrounding gas

abstract:
  We investigate initially the influence of thermomechanical and momentum
exchange noise on the limit to mass sensitivity of nanoresonators with random
rough surfaces, which are characterized by the roughness amplitude, the
correlation length, and the roughness exponent H. In fact, the limit to mass
sensitivity increases with increasing roughness (decreasing H and/or increasing
ratio roughness amplitude/correlation length) if the quality factor associated
with thermomechanical noise is larger than that due to momentum exchange noise.
Finally, the influence of adsorption-desorption noise, which is also influenced
by the surface morphology, is shown to play minimal role in presence of the
other two noise sources.


title:
Radio Observations of the Hubble Deep Field South Region IV: Optical
  Properties of the Faint Radio Population

abstract:
  The Australia Telescope Hubble Deep Field-South (ATHDFS) survey of the Hubble
Deep Field South reaches sensitivities of ~10 miceoJyJy at 1.4, 2.5, 5.2 and
8.7 GHz, making the ATHDFS one of the deepest surveys ever performed with the
Australia Telescope Compact Array. Here we present the optical identifications
of the ATHDFS radio sources using data from the literature. We find that ~66%
of the radio sources have optical counterparts to I = 23.5 mag. Deep HST
imaging of the area identifies a further 12% of radio sources. We present new
spectroscopic observations for 98 of the radio sources, and supplement these
spectroscopic redshifts with photometric ones calculated from 5-band optical
imaging. The host galaxy colors and radio-to-optical ratios indicate that low
luminosity (or "radio quiet") AGN make up a significant proportion of the
sub-mJy radio population, a result which is in accordance with a number of
other deep radio studies. The radio-to-optical ratios of the bright (S_1.4GHz >
1 mJy) sources is consistent with a bimodal distribution.


title: Elementary proof of Rayleigh formula for graphs

abstract:
  The Rayleigh monotonicity is a principle from the theory of electrical
networks. Its combinatorial interpretation says for each two edges of a graph
G, that the presence of one of them in a random spanning tree of G is
negatively correlated with the presence of the other edge. In this paper we
give a self-contained (inductive) proof of Rayleigh monotonicity for graphs.


title:
Real Roots of Random Polynomials and Zero Crossing Properties of
  Diffusion Equation

abstract:
  We study various statistical properties of real roots of three different
classes of random polynomials which recently attracted a vivid interest in the
context of probability theory and quantum chaos. We first focus on gap
probabilities on the real axis, i.e. the probability that these polynomials
have no real root in a given interval. For generalized Kac polynomials, indexed
by an integer d, of large degree n, one finds that the probability of no real
root in the interval [0,1] decays as a power law n^{-\theta(d)} where \theta(d)
> 0 is the persistence exponent of the diffusion equation with random initial
conditions in spatial dimension d. For n \gg 1 even, the probability that they
have no real root on the full real axis decays like
n^{-2(\theta(2)+\theta(d))}. For Weyl polynomials and Binomial polynomials,
this probability decays respectively like \exp{(-2\theta_{\infty}} \sqrt{n})
and \exp{(-\pi \theta_{\infty} \sqrt{n})} where \theta_{\infty} is such that
\theta(d) = 2^{-3/2} \theta_{\infty} \sqrt{d} in large dimension d. We also
show that the probability that such polynomials have exactly k roots on a given
interval [a,b] has a scaling form given by \exp{(-N_{ab} \tilde
\phi(k/N_{ab}))} where N_{ab} is the mean number of real roots in [a,b] and
\tilde \phi(x) a universal scaling function. We develop a simple Mean Field
(MF) theory reproducing qualitatively these scaling behaviors, and improve
systematically this MF approach using the method of persistence with partial
survival, which in some cases yields exact results. Finally, we show that the
probability density function of the largest absolute value of the real roots
has a universal algebraic tail with exponent {-2}. These analytical results are
confirmed by detailed numerical computations.

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


title: Stochastic thermostats: comparison of local and global schemes

abstract:
  We show that a recently introduced stochastic thermostat [J. Chem. Phys. 126
(2007) 014101] can be considered as a global version of the Langevin
thermostat. We compare the global scheme and the local one (Langevin) from a
formal point of view and through practical calculations on a model
Lennard-Jones liquid. At variance with the local scheme, the global thermostat
preserves the dynamical properties for a wide range of coupling parameters, and
allows for a faster sampling of the phase-space.


title: Stabilization of dipole solitons in nonlocal nonlinear media

abstract:
  We address the stabilization of dipole solitons in nonlocal nonlinear
materials by two different approaches. First, we study the properties of such
solitons in thermal nonlinear media, where the refractive index landscapes
induced by laser beams strongly depend on the boundary conditions and on the
sample geometry. We show how the sample geometry impacts the stability of
higher-order solitons in thermal nonlinear media and reveal that dipole
solitons can be made dynami-cally stable in rectangular geometries in contrast
to their counterparts in thermal samples with square cross-section. Second, we
discuss the impact of the saturation of the nonlocal nonlinear response on the
properties of multipole solitons. We find that the saturable response also
stabi-lizes dipole solitons even in symmetric geometries, provided that the
input power exceeds a criti-cal value.


title: Quelques calculs d'espaces $\R^i f_* G$ sur des courbes

abstract:
  We give some properties (cancellation, representability, stratification) of
the sheaf R^i f_* G for an affine relative curve f:U -> S admitting a smooth
compactification and G a solvable group.


title: Fixed points in frustrated magnets revisited

abstract:
  We analyze the validity of perturbative renormalization group estimates
obtained within the fixed dimension approach of frustrated magnets. We
reconsider the resummed five-loop beta-functions obtained within the minimal
subtraction scheme without epsilon-expansion for both frustrated magnets and
the well-controlled ferromagnetic systems with a cubic anisotropy. Analyzing
the convergence properties of the critical exponents in these two cases we find
that the fixed point supposed to control the second order phase transition of
frustrated magnets is very likely an unphysical one. This is supported by its
non-Gaussian character at the upper critical dimension d=4. Our work confirms
the weak first order nature of the phase transition occuring at three
dimensions and provides elements towards a unified picture of all existing
theoretical approaches to frustrated magnets.


title: Optical Orientation in Ferromagnet/Semiconductor Hybrids

abstract:
  The physics of optical pumping of semiconductor electrons in the
ferromagnet/semiconductor hybrids is discussed. Optically oriented
semiconductor electrons detect the magnetic state of the ferromagnetic film. In
turn, the ferromagnetism of the hybrid can be controlled optically with the
help of the semiconductor. Spin-spin interactions near the interface
ferromagnet/semiconductor play crucial role in the optical readout and the
manipulation of ferromagnetism.


title:
Photonic entanglement as a resource in quantum computation and quantum
  communication

abstract:
  Entanglement is an essential resource in current experimental implementations
for quantum information processing. We review a class of experiments exploiting
photonic entanglement, ranging from one-way quantum computing over quantum
communication complexity to long-distance quantum communication. We then
propose a set of feasible experiments that will underline the advantages of
photonic entanglement for quantum information processing.


title:
Existence and Vanishing of the Breathing Mode in Strongly Correlated
  Finite Systems

abstract:
  One of the fundamental eigenmodes of finite interacting systems is the mode
of {\em uniform radial expansion and contraction} -- the ``breathing'' mode
(BM). Here we show in a general way that this mode exists only under special
conditions: i) for harmonically trapped systems with interaction potentials of
the form $1/r^\gamma$ $(\gamma\in\mathbb{R}_{\neq0})$ or $\log(r)$, or ii) for
some systems with special symmetry such as single shell systems forming
platonic bodies. Deviations from the BM are demonstrated for two examples:
clusters interacting with a Lennard-Jones potential and parabolically trapped
systems with Yukawa repulsion. We also show that vanishing of the BM leads to
the occurence of multiple monopole oscillations which is of importance for
experiments.


title: Rademacher averages on noncommutative symmetric spaces

abstract:
  Let E be a separable (or the dual of a separable) symmetric function space,
let M be a semifinite von Neumann algebra and let E(M) be the associated
noncommutative function space. Let $(\epsilon_k)_k$ be a Rademacher sequence,
on some probability space $\Omega$. For finite sequences $(x_k)_k of E(M), we
consider the Rademacher averages $\sum_k \epsilon_k\otimes x_k$ as elements of
the noncommutative function space $E(L^\infty(\Omega)\otimes M)$ and study
estimates for their norms $\Vert \sum_k \epsilon_k \otimes x_k\Vert_E$
calculated in that space. We establish general Khintchine type inequalities in
this context. Then we show that if E is 2-concave, the latter norm is
equivalent to the infimum of $\Vert (\sum y_k^*y_k)^{{1/2}}\Vert + \Vert (\sum
z_k z_k^*)^{{1/2}}\Vert$ over all $y_k,z_k$ in E(M) such that $x_k=y_k+z_k$ for
any k. Dual estimates are given when E is 2-convex and has a non trivial upper
Boyd index. We also study Rademacher averages for doubly indexed families of
E(M).


title: LHC signals for neutrino mass model in bilinear R-parity violating mAMSB

abstract:
  We investigate a neutrino mass model in which the neutrino data is accounted
for by bilinear R-parity violating supersymmetry with anomaly mediated
supersymmetry breaking. We focus on the CERN Large Hadron Collider (LHC)
phenomenology, studying the reach of generic supersymmetry search channels with
leptons, missing energy and jets. A special feature of this model is the
existence of long lived neutralinos and charginos which decay inside the
detector leading to detached vertices. We demonstrate that the largest reach is
obtained in the displaced vertices channel and that practically all of the
reasonable parameter space will be covered with an integrated luminosity of 10
fb-1. We also compare the displaced vertex reaches of the LHC and Tevatron.


title:
ULAS J234311.93-005034.0: A gravitational lens system selected from
  UKIDSS and SDSS

abstract:
  We report the discovery of a new gravitational lens system. This object, ULAS
J234311.93-005034.0, is the first to be selected by using the new UKIRT
Infrared Deep Sky Survey (UKIDSS), together with the Sloan Digital Sky Survey
(SDSS). The ULAS J234311.93-005034.0 system contains a quasar at redshift 0.788
which is doubly imaged, with separation 1.4". The two quasar images have the
same redshift and similar, though not identical, spectra. The lensing galaxy is
detected by subtracting point-spread functions from R-band images taken with
the Keck telescope. The lensing galaxy can also be detected by subtracting the
spectra of the A and B images, since more of the galaxy light is likely to be
present in the latter. No redshift is determined from the galaxy, although the
shape of its spectrum suggests a redshift of about 0.3. The object's lens
status is secure, due to the identification of two objects with the same
redshift together with a lensing galaxy. Our imaging suggests that the lens is
found in a cluster environment, in which candidate arc-like structures, that
require confirmation, are visible in the vicinity. Further discoveries of
lenses from the UKIDSS survey are likely as part of this programme, due to the
depth of UKIDSS and its generally good seeing conditions.


title:
Ratio of viscosity to entropy density in a strongly coupled
  one-component plasma

abstract:
  String theoretical arguments led to the hypothesis that the ratio of
viscosity to entropy of any physical system has a lower bound. Strongly coupled
systems usually have a small viscosity compared to weakly coupled plasmas in
which the viscosity is proportional to the mean free path. In the case of a
one-component plasma the viscosity as a function of the coupling strength shows
a minimum. Here we show that the ratio of viscosity to entropy of a strongly
coupled one-component plasma is always above the lower bound predicted by
string theory.

categories: physics.plasm-ph astro-ph hep-ph nucl-th


title: Completely 1-complemented subspaces of Schatten spaces

abstract:
  We consider the Schatten spaces S^p in the framework of operator space theory
and for any $1\leq p\not=2<\infty$, we characterize the completely
1-complemented subspaces of S^p. They turn out to be the direct sums of spaces
of the form S^p(H,K), where H,K are Hilbert spaces. This result is related to
some previous work of Arazy-Friedman giving a description of all 1-complemented
subspaces of S^p in terms of the Cartan factors of types 1-4. We use operator
space structures on these Cartan factors regarded as subspaces of appropriate
noncommutative L^p-spaces. Also we show that for any $n\geq 2$, there is a
triple isomorphism on some Cartan factor of type 4 and of dimension 2n which is
not completely isometric, and we investigate L^p-versions of such isomorphisms.


title: Thermo-quantum diffusion

abstract:
  A new approach to thermo-quantum diffusion is proposed and a nonlinear
quantum Smoluchowski equation is derived, which describes classical diffusion
in the field of the Bohm quantum potential. A nonlinear thermo-quantum
expression for the diffusion front is obtained, being a quantum generalization
of the classical Einstein law. The quantum diffusion at zero temperature is
also described and a new dependence of the position dispersion on time is
derived. A stochastic Bohm-Langevin equation is also proposed.


title: Dilations and rigid factorisations on noncommutative L^p-spaces

abstract:
  We study some factorisation and dilation properties of completely positive
maps on noncommutative L^p-spaces. We show that Akcoglu's dilation theorem for
positive contractions on classical (=commutative) L^p-spaces has no reasonable
analog in the noncommutative setting. Our study relies on non symmetric analogs
of Pisier's operator space valued noncommutative L^p-spaces that we investigate
in the first part of the paper.


title: On the Constancy of the Characteristic Mass of Young Stars

abstract:
  The characteristic mass M_c in the stellar initial mass function (IMF) is
about constant for most star-forming regions. Numerical simulations
consistently show a proportionality between M_c and the thermal Jeans mass M_J
at the time of cloud fragmentation, but no models have explained how it can be
the same in diverse conditions. Here we show that M_J depends weakly on
density, temperature, metallicity, and radiation field in three environments:
the dense cores where stars form, larger star-forming regions ranging from GMCs
to galactic disks, and the interiors of HII regions and super star clusters. In
dense cores, the quantity T^{3/2}n^{-1/2} that appears in M_J scales with core
density as n^{0.25} or with radiation density as U^{0.1} at the density where
dust and gas come into thermal equilibrium. On larger scales, this quantity
varies with ambient density as n^{-0.05} and ambient radiation field as
U^{-0.033} when the Kennicutt-Schmidt law of star formation determines U(n). In
super star clusters with ionization and compression of pre-stellar globules,
M_J varies as the 0.13 power of the cluster column density. These weak
dependencies on n, U, and column density imply that most environmental
variations affect the thermal Jeans mass by at most a factor of ~2.
Cosmological increases in M_J, which have been suggested by observations, may
be explained if the star formation efficiency is systematically higher at high
redshift for a given density and pressure, if dust grains are smaller at lower
metallicity, and so hotter for a given radiation field, or if small pre-stellar
cores are more severely ionized in extreme starburst conditions.


title: Molecular electronics in junctions with energy disorder

abstract:
  We investigate transport through molecular wires whose energy levels are
affected by environmental fluctuations. We assume that the relevant
fluctuations are so slow that they, within a tight-binding description, can be
described by disordered, Gaussian distributed onsite energies. For long wires,
we find that the corresponding current distribution can be rather broad even
for a small energy variance. Moreover, we analyse with a Floquet master
equation the interplay of laser excitations and static disorder. Then the
disorder leads to spatial asymmetries such that the laser diving can induce a
ratchet current.


title:
A modified Potts model for the interaction of surface-attached polymer
  complexes

abstract:
  We present a simple yet generic model for the behavior of a system of many
surface-attached flexible polymers with rigid side chains. Beyond its potential
application in describing the dynamics of the extracellular matrix of mammalian
cells, the model itself shows an interesting phase transition behavior since
the underlying models (a two-dimensional Potts model and a XY-model) undergo
different phase transitions.


title: Measurement of XUV-absorption spectra of ZnS radiatively heated foils

abstract:
  Time-resolved absorption of zinc sulfide (ZnS) and aluminum in the XUV-range
has been measured. Thin foils in conditions close to local thermodynamic
equilibrium were heated by radiation from laser-irradiated gold spherical
cavities. Analysis of the aluminum foil radiative hydrodynamic expansion, based
on the detailed atomic calculations of its absorption spectra, showed that the
cavity emitted flux that heated the absorption foils corresponds to a radiation
temperature in the range 55 60 eV. Comparison of the ZnS absorption spectra
with calculations based on a superconfiguration approach identified the
presence of species Zn6+ - Zn8+ and S5+ - S6+. Based on the validation of the
radiative source simulations, experimental spectra were then compared to
calculations performed by post-processing the radiative hydrodynamic
simulations of ZnS. Satisfying agreement is found when temperature gradients
are accounted for.


title:
Oscillations in the expression of a self-repressed gene induced by a
  slow transcriptional dynamics

abstract:
  We revisit the dynamics of a gene repressed by its own protein in the case
where the transcription rate does not adapt instantaneously to protein
concentration but is a dynamical variable. We derive analytical criteria for
the appearance of sustained oscillations and find that they require degradation
mechanisms much less nonlinear than for infinitely fast regulation.
Deterministic predictions are also compared with stochastic simulations of this
minimal genetic oscillator.


title:
Consistent price systems and face-lifting pricing under transaction
  costs

abstract:
  In markets with transaction costs, consistent price systems play the same
role as martingale measures in frictionless markets. We prove that if a
continuous price process has conditional full support, then it admits
consistent price systems for arbitrarily small transaction costs. This result
applies to a large class of Markovian and non-Markovian models, including
geometric fractional Brownian motion. Using the constructed price systems, we
show, under very general assumptions, the following ``face-lifting'' result:
the asymptotic superreplication price of a European contingent claim $g(S_T)$
equals $\hat{g}(S_0)$, where $\hat{g}$ is the concave envelope of $g$ and $S_t$
is the price of the asset at time $t$. This theorem generalizes similar results
obtained for diffusion processes to processes with conditional full support.


title: Separable states and positive maps II

abstract:
  Using the natural duality between linear functionals on tensor products of
C*-algebras with the trace class operators on a Hilbert space H and linear maps
of the C*-algebra into B(H), we give two characterizations of separability, one
relating it to abelianness of the definite set of the map, and one on tensor
products of nuclear and UHF C*-algebras


title: On the number of graphs not containing $K_{3,3}$ as a minor

abstract:
  We derive precise asymptotic estimates for the number of labelled graphs not
containing $K_{3,3}$ as a minor, and also for those which are edge maximal.
Additionally, we establish limit laws for parameters in random
$K_{3,3}$-minor-free graphs, like the expected number of edges. To establish
these results, we translate a decomposition for the corresponding graph class
into equations for generating functions and use singularity analysis. We also
find a precise estimate for the number of graphs not containing the graph
$K_{3,3}$ plus an edge as a minor.


title:
The role of interactions in spin-polarised atomic Fermi gases at
  unitarity

abstract:
  We study the zero temperature properties of a trapped polarized Fermi gas at
unitarity by assuming phase separation between an unpolarized superfluid and a
polarized normal phase. The effects of the interaction are accounted using the
formalism of quasi-particles to build up the equation of state of the normal
phase with the Monte Carlo results for the relevant parameters. Our predictions
for the Chandrasekhar-Clogston limit of critical polarization and for the
density profiles, including the density jump at the interface, are confirmed
with excellent accuracy by the recent experimental results at MIT. The role of
interaction on the radial width of the minority component, on the gap of the RF
transition and on the spin oscillations in the normal phase is also discussed.
Our analysis points out the Fermi liquid nature of these strongly interacting
spin polarized configurations.


title: Magnetic Moments of Heavy $\Xi_{Q}$ Baryons in Light Cone QCD Sum Rules

abstract:
  The magnetic moments of heavy $\Xi_{Q}$ baryons containing a single charm or
bottom quark are calculated in the framework of light cone QCD sum rules
method. A comparison of our results with the predictions of the quark models is
presented.


title:
The European Electricity Grid System and Winter Peak Load Stress: For
  how long can the european grid system survive the ever increasing demand
  during cold winter days?

abstract:
  The rich countries of Western Europe and its citizens benefited during at
least the last 30 years from an extraordinary stable electricity grid. This
stability was achieved by the european grid system and a large flexible and
reliable spare power plant capacity. This system allowed a continuous demand
growth during the past 10-20 years of up to a few % per year. However,
partially due to this overcapacity, no new large power plants have been
completed during the past 10-15 years. The obvious consequence is that the
reliable spare capacity has been reduced and that a further yearly demand
growth of 1-2% for electric energy can only be achieved if new power plants
will be constructed soon. Data from various European countries, provided by the
UCTE, indicate that the system stress during peak load times and especially
during particular cold winter days is much larger than generally assumed. In
fact, the latest UCTE data on reliable power capacity indicate that already
during the Winter 2007/8 only a few very cold winter days in Western Europe
could have resulted in very unpleasant supply problems during the early evening
peak load times in France and the neighboring countries.
  An analysis of the potential to build and operate new power plants
demonstrates that no short term solution, which allows a further continuous
1-2% consumption growth seems to exist. Thus, without any action from the
various governments in Europe to reduce the electricity demand in a serious
way, the risk of blackouts will increase dramatically in the near future.
Instead of simply waiting for the blackout disaster to happen, a few simple
short term political actions are suggested.


title: The effect of ambipolar resistivity on the formation of dense cores

abstract:
  We aim to understand the formation of dense cores by magnetosonic waves in
regions where the thermal to magnetic pressure ratio is small. Because of the
low-ionisation fraction in molecular clouds, neutral and charged particles are
weakly coupled. Ambipolar diffusion then plays an important role in the
formation process. A quiescent, uniform plasma is perturbed by a fast-mode
wave. Using 2D numerical simulations, we follow the evolution of the fast-mode
wave. The simulations are done with a multifluid, adaptive mesh refinement MHD
code. Initial perturbations with wavelengths that are 2 orders of magnitude
larger than the dissipation length are strongly affected by the ion-neutral
drift. Only in situations where there are large variations in the magnetic
field corresponding to a highly turbulent gas can fast-mode waves generate
dense cores. This means that, in most cores, no substructure can be produced.
However, Core D of TMC-1 is an exception to this case. Due to its atypically
high ionisation fraction, waves with wavelengths up to 3 orders of magnitude
greater than the dissipation length can be present. Such waves are only weakly
affected by ambipolar diffusion and can produce dense substructure without
large wave-amplitudes. Our results also explain the observed transition from
Alfvenic turbulent motion at large scales to subsonic motions at the level of
dense cores.


title: The Mid-Infrared Fundamental Plane of Early-Type Galaxies

abstract:
  Three observables of early-type galaxies - size ($r_{e}$), surface brightness
($I_{e}$), and velocity dispersion ($\sigma_{0}$) - form a tight planar
correlation known as the fundamental plane (FP), which has provided great
insights into the galaxy formation and the evolution processes. However, the FP
has been found to be tilted against the simple virial expectation, prompting
debates on its origin. In order to investigate the contribution of systematic
stellar population variation to the FP tilt, we study here the FP relations of
early-type galaxies in mid-infrared (MIR) which may represent the stellar mass
well. We examined the wavelength dependence of the FP coefficients, $a$ and $b$
in $\log r_{e}= a\log\sigma_{0} + b\log< I >_{e} + c$, using a sample of 56
early-type galaxies for which visible (V-band), near-infrared (K-band), and MIR
(Spitzer IRAC, 3.6--8.0$\mu$m) data are available. We find that the coefficient
$a$ increases as a function of wavelength as $da/d\lambda=0.11\pm0.04\mu
m^{-1}$, while the coefficient $b$ reaches the closest to -1 at 3.6--5.8$\mu$m.
When applied to the visible FP coefficients derived from a larger sample of
nearby early-type galaxies, we get the FP relation with $(a,b) \simeq
$(1.6--1.8,-0.9) at 3.6$\mu$m. Our result suggests that the stellar population
effect can explain more than half of the FP tilt, closing the gap between the
virial expectation and the optical FP. The reduction in the FP tilt is
reflected in the dynamical mass-to-light ratio, $M_{dyn}/L$, dependence on $L$
which decreases toward 3.6--5.8$\mu$m, suggesting that the MIR light better
represents mass than the shorter wavelengths.


title: Fermi Surface Reconstruction in CeRh$_{1-x}$Co$_{x}$In$_{5}$

abstract:
  The evolution of the Fermi surface of CeRh$_{1-x}$Co$_x$In$_5$ was studied as
a function of Co concentration $x$ via measurements of the de Haas-van Alphen
effect. By measuring the angular dependence of quantum oscillation frequencies,
we identify a Fermi surface sheet with $f$-electron character which undergoes
an abrupt change in topology as $x$ is varied. Surprisingly, this
reconstruction does not occur at the quantum critical concentration $x_c$,
where antiferromagnetism is suppressed to T=0. Instead we establish that this
sudden change occurs well below $x_c$, at the concentration x ~ 0.4 where long
range magnetic order alters its character and superconductivity appears. Across
all concentrations, the cyclotron effective mass of this sheet does not
diverge, suggesting that critical behavior is not exhibited equally on all
parts of the Fermi surface.


title: Sensitivity and spatial resolution of square loop SQUID magnetometers

abstract:
  We calculate the flux threading the pick-up coil of a square SQUID
magnetometer in the presence of a current dipole source. The result reproduces
that of a circle coil magnetometer calculated by Wikswo with only small
differences. However it has a simpler form so that it is possible to derive
from it closed form expressions for the current dipole sensitivity and the
spatial resolution. The results are useful to assess the overall performance of
the device and to compare different designs.


title:
Diameter-dependent conductance oscillations in carbon nanotubes upon
  torsion

abstract:
  We combine electromechanical measurements with {\em ab initio} density
functional calculations to settle the controversy about the origin of
torsion-induced conductance oscillations in multi-wall carbon nanotubes.
According to our observations, the oscillation period is inversely proportional
to the squared diameter of the nanotube, as expected for a single-wall nanotube
of the same diameter. This is supported by our theoretical finding that
differential torsion effectively decouples the walls of a multi-wall nanotube
near the Fermi level and moves the Fermi momentum across quantization lines. We
exclude the alternative explanation linked to registry changes between the
walls, since it would cause a different diameter dependence of the oscillation
period.


title: Phonon mediated tunneling into graphene

abstract:
  Recent scanning tunneling spectroscopy experiments [V. W. Brar et. al., Appl.
Phys. Lett. 91, 122102 (2007), Y. Zhang et. al., arXiv:0802.4315 (2008)] on
graphene reported an unexpected gap of about $\pm 60$meV around the Fermi
level. Here, we give a theoretical investigation explaining the experimentally
observed spectra and confirming the phonon mediated tunneling as the reason for
the gap: We study the real space properties of the wave functions involved in
the tunneling process by means of ab-initio theory and present a model for the
electron-phonon interaction, which couples the graphene's Dirac electrons with
quasi free electron states at the Brillouin zone center. The self-energy
associated with this electron-phonon interaction is calculated and its effects
on tunneling into graphene are discussed. In particular, good agreement of the
tunneling density of states within our model and the experimental[V. W. Brar
et. al., Appl. Phys. Lett. 91, 122102 (2007), Y. Zhang et. al., arXiv:0802.4315
(2008)] dI/dU spectra is found.


title:
Hall effect measurements on YbRh2Si2 and relatives in the light of
  electronic structure calculations

abstract:
  We report experimental and theoretical investigations of the Hall effect in
YbRh2Si2 and its reference compounds LuRh2Si2 and YbIr2Si2. Based on
band-structure calculations we identify two bands dominating the Hall
coefficient in all these compounds. For the case of LuRh2Si2 - the non-magnetic
reference compound of YbRh2Si2 - the temperature dependence of the Hall
coefficient is described quantitatively to arise from two hole-like bands. For
YbIr2Si2 and YbRh2Si2, renormalized band calculations yield two bands of
opposite character. In YbRh2Si2 these two bands almost compensate each other.
We present strong indications that the sample dependences of the
low-temperature Hall coefficient observed for YbRh2Si2 arise from slight
variations of the relative scattering rates of the two bands. Minute changes of
the composition appear to be the origin.


title: A simple conceptual model of abrupt glacial climate events

abstract:
  Here we use a very simple conceptual model in an attempt to reduce essential
parts of the complex nonlinearity of abrupt glacial climate changes (the
so-called Dansgaard-Oeschger events) to a few simple principles, namely (i) a
threshold process, (ii) an overshooting in the stability of the system and
(iii) a millennial-scale relaxation. By comparison with a so-called Earth
system model of intermediate complexity (CLIMBER-2), in which the events
represent oscillations between two climate states corresponding to two
fundamentally different modes of deep-water formation in the North Atlantic, we
demonstrate that the conceptual model captures fundamental aspects of the
nonlinearity of the events in that model. We use the conceptual model in order
to reproduce and reanalyse nonlinear resonance mechanisms that were already
suggested in order to explain the characteristic time scale of
Dansgaard-Oeschger events. In doing so we identify a new form of stochastic
resonance (i.e. an overshooting stochastic resonance) and provide the first
explicitly reported manifestation of ghost resonance in a geosystem, i.e. of a
mechanism which could be relevant for other systems with thresholds and with
multiple states of operation. Our work enables us to explicitly simulate
realistic probability measures of Dansgaard-Oeschger events (e.g. waiting time
distributions, which are a prerequisite for statistical analyses on the
regularity of the events by means of Monte-Carlo simulations). We thus think
that our study is an important advance in order to develop more adequate
methods to test the statistical significance and the origin of the proposed
glacial 1470-year climate cycle.


title: Chern-number spin Hamiltonians for magnetic nano-clusters by DFT methods

abstract:
  Combining field-theoretical methods and ab-initio calculations, we construct
an effective Hamiltonian with a single giant-spin degree of freedom, capable of
the describing the low-energy spin dynamics of ferromagnetic metal nanoclusters
consisting of up to a few tens of atoms. In our procedure, the magnetic moment
direction of the Kohn-Sham SDFT wave-function is constrained by means of a
penalty functional, allowing us to explore the entire parameter space of
directions, and to extract the magnetic anisotropy energy and Berry curvature
functionals. The average of the Berry curvature over all magnetization
directions is a Chern number - a topological invariant that can only take on
values equal to multiples of one half, representing the dimension of the
Hilbert space of the effective spin system. The spin Hamiltonian is obtained by
quantizing the classical anisotropy energy functional, after performing a
change of variables to a constant Berry curvature space. The purpose of this
article is to examine the impact of the topological effect from the Berry
curvature on the low-energy total-spin-system dynamics. To this end, we study
small transition metal clusters: Co$_{n}$ ($n=2,...,5$), Rh$_{2}$, Ni$_{2}$,
Pd$_{2}$, Mn$_{x}$N$_{y}$, Co$_{3}$Fe$_{2}$.


title: $\alpha$-Decay Lifetime in Superheavy Nuclei With $A>282$

abstract:
  Nuclei with $A>282$ have been studied in the Relativistic Mean Field approach
using the force FSU Gold and a zero range pairing interaction. The
Euler-Lagrange equations have been solved in the co-ordinate space. Alpha
nucleus potential has been constructed with the DDM3Y1 interaction, which has
an exponential density dependence, in the double folding model using the
nucleon densities in the daughter nucleus and the $\alpha$ particle. Half lives
of $\alpha$ decay have been calculated for tunneling of the $\alpha$ particle
through the potential barrier in the WKB approximation and assuming a constant
preformation probability. The resulting values agree well with experimental
measurements.


title: Electron transport in a slot-gate Si MOSFET

abstract:
  The transversal and longitudinal resistance in the quantum Hall effect regime
was measured in a Si MOSFET sample in which a slot-gate allows one to vary the
electron density and filling factor in different parts of the sample. In case
of unequal gate voltages, the longitudinal resistances on the opposite sides of
the sample differ from each other because the originated Hall voltage
difference is added to the longitudinal voltage only on one side depending on
the gradient of the gate voltages and the direction of the external magnetic
field. After subtracting the Hall voltage difference, the increase in
longitudinal resistance is observed when electrons on the opposite sides of the
slot occupy Landau levels with different spin orientations.


title:
Creation of neutron spinless pairs in a superfluid liquid $^4$He and a
  neutron gas mixture

abstract:
  First, the creation of a free neutron spinless pairs is predicted in a
superfluid liquid $^4$He and a neutron gas mixture. For solving the given
problem, it is presented an exact solution to the model of dilute Bose gas as
an extension of the Bogoliubov model, at quantity of the condensate fraction
varying in the state $0\leq\frac{N_0}{N}\leq 1$, which in turn might be useful
for a description of the superfluid liquid $^4$He. Due to an application of
presented new model of dilute Bose gas, we prove that an appearance of atoms in
the condensate is a suppressor for the collective modes as well as a creator
for single-particle excitations On other hand, it is shown that the terms of
the interaction between the Bogoliubov excitations (Bogoliubov phonon-roton
modes) and the density modes of the neutron meditate an attractive interaction
via the neutron modes, which in turn leads to a bound state on a spinless
neutron pair.


title: Quantum Isometry Group of the n tori

abstract:
  We show that the Quantum Isometry Group(as introduced in \cite{goswami}) of
the n tori is the classical isometry group. Moreover, using a result in
\cite{bhowmick goswami}, we conclude that the Quantum Isometry group of the
noncommutative n tori is a Rieffel deformation of the Quantum Isometry Group of
the commutative n tori.