title:
Instantaneous and lagged measurements of linear and nonlinear dependence
  between groups of multivariate time series: frequency decomposition

abstract:
  Measures of linear dependence (coherence) and nonlinear dependence (phase
synchronization) between any number of multivariate time series are defined.
The measures are expressed as the sum of lagged dependence and instantaneous
dependence. The measures are non-negative, and take the value zero only when
there is independence of the pertinent type. These measures are defined in the
frequency domain and are applicable to stationary and non-stationary time
series. These new results extend and refine significantly those presented in a
previous technical report (Pascual-Marqui 2007, arXiv:0706.1776 [stat.ME],
http://arxiv.org/abs/0706.1776), and have been largely motivated by the seminal
paper on linear feedback by Geweke (1982 JASA 77:304-313). One important field
of application is neurophysiology, where the time series consist of electric
neuronal activity at several brain locations. Coherence and phase
synchronization are interpreted as "connectivity" between locations. However,
any measure of dependence is highly contaminated with an instantaneous,
non-physiological contribution due to volume conduction and low spatial
resolution. The new techniques remove this confounding factor considerably.
Moreover, the measures of dependence can be applied to any number of brain
areas jointly, i.e. distributed cortical networks, whose activity can be
estimated with eLORETA (Pascual-Marqui 2007, arXiv:0710.3341 [math-ph]).


title: The Glueball Superpotential for G_2

abstract:
  We perform a perturbative computation of the glueball superpotential for N=1
supersymmetric G_2 gauge theory with one adjoint matter multiplet. We find that
the computation simplifies because the bosonic momentum integral cancels with
the fermionic momentum integral. The effective glueball superpotential allows
us to gain an insight into non-perturbative aspect of the supersymetric gauge
theory.


title:
Defect healing at room temperature in pentacene thin films and improved
  transistor performance

abstract:
  We report on a healing of defects at room temperature in the organic
semiconductor pentacene. This peculiar effect is a direct consequence of the
weak intermolecular interaction which is characteristic of organic
semiconductors. Pentacene thin-film transistors were fabricated and
characterized by in situ gated four-terminal measurements. Under high vacuum
conditions (base pressure of order 10E-8 mbar), the device performance is found
to improve with time. The effective field-effect mobility increases by as much
as a factor of two and mobilities up to 0.45 cm2/Vs were achieved. In addition,
the contact resistance decreases by more than an order of magnitude and there
is a significant reduction in current hysteresis. Oxygen/nitrogen exposure and
annealing experiments show the improvement of the electronic parameters to be
driven by a thermally promoted process and not by chemical doping. In order to
extract the spectral density of trap states from the transistor
characteristics, we have implemented a powerful scheme which allows for a
calculation of the trap densities with high accuracy in a straightforward
fashion. We show the performance improvement to be due to a reduction in the
density of shallow traps <0.15 eV from the valence band edge, while the
energetically deeper traps are essentially unaffected. This work contributes to
an understanding of the shallow traps in organic semiconductors and identifies
structural point defects within the grains of the polycrystalline thin films as
a major cause.


title: Floquet system, Bloch oscillation, and Stark ladder

abstract:
  We prove the multi-band Bloch oscillation and Stark ladder in the $nk$ and
site representation from the Floquet theorem. The proof is also possible from
the equivalence between the Floquet system, Bloch oscillation, and the rotator
with spin. We also exactly solve the periodically driven two level atom and two
band Bloch oscillation in terms of Heun function.


title:
Unraveling neutrino parameters with a magical beta-beam experiment at
  INO

abstract:
  We expound in detail the physics reach of an experimental set-up in which the
proposed large magnetized iron detector at the India-based Neutrino Observatory
(INO) would serve as the far detector for a so-called beta-beam. If this pure
$\nue$ and/or $\anue$ beam is shot from some source location like CERN such
that the source-detector distance $L \simeq 7500$ km, the impact of the CP
phase $\delta_{CP}$ on the oscillation probability and associated parameter
correlation and degeneracies are almost negligible. This ``magical'' beta-beam
experiment would have unprecedented sensitivity to the neutrino mass hierarchy
and $\theta_{13}$, two of the missing ingredients needed for our understanding
of the neutrino sector. With Lorentz boost $\gamma=650$ and irrespective of the
true value of $\delta_{CP}$, the neutrino mass hierarchy could be determined at
$3\sigma$ C.L. if $\sin^22\theta_{13}{\rm {(true)}} > 5.6 \times 10^{-4}$ and
we can expect an unambiguous signal for $\theta_{13}$ at $3\sigma$ C.L. if
$\sin^22\theta_{13}{\rm {(true)}} > 5.1 \times 10^{-4}$ independent of the true
neutrino mass hierarchy.


title: On the Thermodynamic Temperature of a General Distribution

abstract:
  The concept of temperature is one of the key ideas in describing the
thermodynamical properties of a physical system. In classical statistical
mechanics of ideal gases, the notion of temperature can be described in two
different ways, the kinetic temperature and the thermodynamic temperature. For
the Boltzmann distribution, the two notions lead to the same result. However,
for a general probability density function, while the kinetic temperature has
been commonly used, there appears to be no corresponding general definition of
thermodynamic temperature. In this paper, we propose such a definition and show
that it is connected to the Fisher information associated with the distribution
of the momenta.


title: Semiconductor Spintronics

abstract:
  Spintronics refers commonly to phenomena in which the spin of electrons in a
solid state environment plays the determining role. In a more narrow sense
spintronics is an emerging research field of electronics: spintronics devices
are based on a spin control of electronics, or on an electrical and optical
control of spin or magnetism. This review presents selected themes of
semiconductor spintronics, introducing important concepts in spin transport,
spin injection, Silsbee-Johnson spin-charge coupling, and spindependent
tunneling, as well as spin relaxation and spin dynamics. The most fundamental
spin-dependent nteraction in nonmagnetic semiconductors is spin-orbit coupling.
Depending on the crystal symmetries of the material, as well as on the
structural properties of semiconductor based heterostructures, the spin-orbit
coupling takes on different functional forms, giving a nice playground of
effective spin-orbit Hamiltonians. The effective Hamiltonians for the most
relevant classes of materials and heterostructures are derived here from
realistic electronic band structure descriptions. Most semiconductor device
systems are still theoretical concepts, waiting for experimental
demonstrations. A review of selected proposed, and a few demonstrated devices
is presented, with detailed description of two important classes: magnetic
resonant tunnel structures and bipolar magnetic diodes and transistors. In most
cases the presentation is of tutorial style, introducing the essential
theoretical formalism at an accessible level, with case-study-like
illustrations of actual experimental results, as well as with brief reviews of
relevant recent achievements in the field.


title:
Experimental Test of the Dynamical Coulomb Blockade Theory for Short
  Coherent Conductors

abstract:
  We observed the recently predicted quantum suppression of dynamical Coulomb
blockade on short coherent conductors by measuring the conductance of a quantum
point contact embedded in a tunable on-chip circuit. Taking advantage of the
circuit modularity we measured most parameters used by the theory. This allowed
us to perform a reliable and quantitative experimental test of the theory.
Dynamical Coulomb blockade corrections, probed up to the second conductance
plateau of the quantum point contact, are found to be accurately normalized by
the same Fano factor as quantum shot noise, in excellent agreement with the
theoretical predictions.


title: Comparison of D --> K_s^0 pi and D --> K_L^0 pi Decay Rates

abstract:
  We present measurements of D -> K0_S pi and D -> K0_L pi branching fractions
using 281 pb-1 of psi(3770) data at the CLEO-c experiment. We find that B(D0 ->
K0_S pi0) is larger than B(D0 -> K0_L pi0), with an asymmetry of R(D0) = 0.108
+- 0.025 +- 0.024. For B(D+ -> K0_S pi+) and B(D+ -> K0_L pi+), we observe no
measurable difference; the asymmetry is R(D+) = 0.022 +- 0.016 +- 0.018. The D0
asymmetry is consistent with the value based on the U-spin prediction A(D0 ->
K0 pi0)/A(D0 -> K0bar pi0) = -tan^2(theta_C), where theta_C is the Cabibbo
angle.


title: Low-Temperature Collapse of Electron Localisation in Two Dimensions

abstract:
  We report direct experimental evidence that the insulating phase of a
disordered, yet strongly interacting two-dimensional electron system (2DES)
becomes unstable at low temperatures. As the temperature decreases, a
transition from insulating to metal-like transport behaviour is observed, which
persists even when the resistivity of the system greatly exceeds the quantum of
resistivity h/e^2. The results have been achieved by measuring transport on a
mesoscopic length-scale while systematically varying the strength of disorder.


title: Phantom Energy with Variable G and Lambda

abstract:
  We have investigated a cosmological model of a phantom energy with a variable
cosmological constant ($\Lambda$) depending on the energy density ($\rho$) as
$\Lambda\propto \rho^{-\alpha}$, $\alpha=\rm const.$ and a variable
gravitational constant ($G$). The model requires $\alpha<0$ and a negative
gravitational constant. A negative gravitational constant may forbid
\emph{black holes} to form a particle horizon in a background of phantom
energy. This implies that black holes are naked, and consequently the
\emph{Cosmic Censorship} theorem is violated. The cosmological constant evolves
with time as, $\Lambda\propto t^{-2}$. For $\omega>-1$ and $\alpha<-1$ the
cosmological constant, $\Lambda<0$, $G>0$ and $\rho$ decrease with cosmic
expansion. For ordinary matter (or dark matter), i.e., $\omega>-1$ we have
$-1<\alpha<0$ and $\beta>0$ so that $G>0$ increases with time and $\rho$
decreases with time. Cosmic acceleration with dust particles is granted
provided $-{2/3}<\alpha <0$ and $\Lambda>0$.


title: Predicting relevant empty spots in social interaction

abstract:
  An empty spot refers to an empty hard-to-fill space which can be found in the
records of the social interaction, and is the clue to the persons in the
underlying social network who do not appear in the records. This contribution
addresses a problem to predict relevant empty spots in social interaction.
Homogeneous and inhomogeneous networks are studied as a model underlying the
social interaction. A heuristic predictor function approach is presented as a
new method to address the problem. Simulation experiment is demonstrated over a
homogeneous network. A test data in the form of baskets is generated from the
simulated communication. Precision to predict the empty spots is calculated to
demonstrate the performance of the presented approach.


title: Symmetry breaking in Laughlin's state on a cylinder

abstract:
  We investigate Laughlin's fractional quantum Hall effect wave function on a
cylinder. We show that it displays translational symmetry breaking in the axial
direction for sufficiently thin cylinders. At filling factor 1/p, the period is
p times the period of the filled lowest Landau level. The proof uses a
connection with one-dimensional polymer systems and discrete renewal equations.


title: Net-Baryon Physics: Basic Mechanisms

abstract:
  It is well known that, in nuclear collisions, a sizable fraction of the
available energy is carried away by baryons. As the baryon number is conserved,
the net-baryon $B-\bar{B}$ retains information on the energy-momentum carried
by the incoming nuclei. A simple but consistent model for net-baryon production
in high energy hadron-hadron, hadron-nucleus and nucleus-nucleus collisions is
presented. The basic ingredients of the model are valence string formation
based on standard PDFs with QCD evolution and string fragmentation via the
Schwinger mechanism. The results of the model are presented and compared with
both data and existing models. These results show that a good description of
the main features of net-baryon data is possible on the framework of a
simplistic model, with the advantage of making the fundamental production
mechanisms manifest.


title:
Ground-state energy eigenvalue calculation of the quantum mechanical
  well $V(x)={1/2}kx^{2}+\lambda {x^{4}}$ via analytical transfer matrix method

abstract:
  The analytical transfer matrix technique is applied to the Schr\"{o}dinger
equation of symmetric quartic-well potential problem in the form
$V(x)={1/2}kx^{2}+\lambda{x^{4}}.$ This gives quantization condition from which
we can calculate the ground-state energy eigenvalues numerically. We also
compare the results with those obtained from numerical shooting method,
perturbation theory, and WKB method.


title:
Source shape determination with directional fragment-fragment velocity
  correlations

abstract:
  Correlation functions, constructed from directional projections of the
relative velocities of fragments, are used to determine the shape of the
breakup volume in coordinate space. For central collisions of 129Xe + natSn at
50 MeV per nucleon incident energy, measured with the 4pi multi-detector INDRA
at GSI, a prolate shape aligned along the beam direction with an axis ratio of
1:0.7 is deduced. The sensitivity of the method is discussed in comparison with
conventional fragment-fragment velocity correlations.


title:
(O(V+F), O(V)) is a Gelfand pair for any quadratic space V over a local
  field F

abstract:
  Let V be a quadratic space with a form q over an arbitrary local field F of
characteristic different from 2. Let $W=V \oplus Fe$ with the form Q extending
q with Q(e)=1. Consider the standard embedding of O(V) into O(W) and the
two-sided action of $O(V)\times O(V)$ on $O(W)$.
  In this note we show that any $O(V)\times O(V)$-invariant distribution on
O(W) is invariant with respect to transposition. This result was earlier proven
in a bit different form in [vD] for F=R, in [AvD] for F=C and in [BvD] for
p-adic fields. Here we give a different proof.
  Using results from [AGS], we show that this result on invariant distributions
implies that the pair (O(V),O(W)) is a Gelfand pair. In the archimedean setting
this means that for any irreducible admissible smooth Frechet representation E
of O(W) we have $dim Hom_{O(V)}(E,C) \leq 1.$
  A stronger result for p-adic fields is obtained in [AGRS].


title: Two-dimensional Gauge Theories and Quantum Integrable Systems

abstract:
  In this paper the relation between 2d topological gauge theories and Bethe
Ansatz equations is reviewed. In addition we present some new results and
clarifications. We hope the relations discussed here are particular examples of
more general relations between quantum topological fields theories in
dimensions $d\leq 4$ and quantum integrable systems.


title:
Quantum Scholasticism: On Quantum Contexts, Counterfactuals, and the
  Absurdities of Quantum Omniscience

abstract:
  Unlike classical information, quantum knowledge is restricted to the outcome
of measurements of maximal observables corresponding to single contexts.


title:
A 3D Study of Combined Density and Temperature Fluctuations in Gaseous
  Nebulae I: Theory

abstract:
  This draft (in preparation) has been withdrawn so as to be combined with its
second part (work also in preparation), to produce a single paper, that
includes further analysis and revisions done after new important results
obtained.


title:
A Digital Switch and Femto-Tesla Magnetic Field Sensor Based on Fano
  Resonance in a Spin Field Effect Transistor

abstract:
  We show that a Spin Field Effect Transistor, realized with a semiconductor
quantum wire channel sandwiched between half-metallic ferromagnetic contacts,
can have Fano resonances in the transmission spectrum. These resonances appear
because the ferromagnets are half-metallic, so that the Fermi level can be
placed above the majority but below the minority spin band. In that case, the
majority spins will be propagating, but the minority spins will be evanescent.
At low temperatures, the Fano resonances can be exploited to implement a
digital binary switch that can be turned on or off with a very small gate
voltage swing of few tens of microvolts, leading to extremely small dynamic
power dissipation during switching. An array of 500,000 x 500,000 such
transistors can detect ultrasmall changes in a magnetic field with a
sensitivity of 1 femto-Tesla/sqrt{Hz}, if each transistor is biased near a Fano
resonance.


title: Radon transform on symmetric matrix domains

abstract:
  Let $\bbK=\mathbb R, \mathbb C, \mathbb H$ be the field of real, complex or
quaternionic numbers and $M_{p, q}(\bbK)$ the vector space of all $p\times
q$-matrices. Let $X$ be the matrix unit ball in $M_{n-r, r}(\bbK)$ consisting
of contractive matrices. As a symmetric space, $X=G/K=O(n-r, r)/O(n-r)\times
O(r)$, $U(n-r, r)/U(n-r)\times U(r)$ and respectively $Sp(n-r, r)/Sp(n-r)\times
Sp(r)$. The matrix unit ball $y_0$ in $M_{r^\prime-r, r}$ with $r^\prime \le
n-1$ is a totally geodesic submanifold of $X$ and let $Y$ be the set of all
$G$-translations of the submanifold $y_0$. The set $Y$ is then a manifold and
an affine symmetric space. We consider the Radon transform $\mathcal Rf(y)$ for
functions $f\in C_0^\infty(X)$ defined by integration of $f$ over the subset
$y$, and the dual transform $\mathcal R^t F(x), x\in X$ for functions $F(y)$ on
$Y$. We find inversion formulas by constructing explicit certain invariant
differential operators.


title: On Weak Tail Domination of Random Vectors

abstract:
  Motivated by a question of Krzysztof Oleszkiewicz we study a notion of weak
tail domination of random vectors. We show that if the dominating random
variable is sufficiently regular weak tail domination implies strong tail
domination. In particular positive answer to Oleszkiewicz question would follow
from the so-called Bernoulli conjecture.


title:
A constructive Borel-Cantelli Lemma. Constructing orbits with required
  statistical properties

abstract:
  In the general context of computable metric spaces and computable measures we
prove a kind of constructive Borel-Cantelli lemma: given a sequence
(constructive in some way) of sets $A_{i}$ with effectively summable measures,
there are computable points which are not contained in infinitely many $A_{i}$.
  As a consequence of this we obtain the existence of computable points which
follow the \emph{typical statistical behavior} of a dynamical system (they
satisfy the Birkhoff theorem) for a large class of systems, having computable
invariant measure and a certain ``logarithmic'' speed of convergence of
Birkhoff averages over Lipshitz observables. This is applied to uniformly
hyperbolic systems, piecewise expanding maps, systems on the interval with an
indifferent fixed point and it directly implies the existence of computable
numbers which are normal with respect to any base.

categories: math.CA cs.IT math.DS math.IT math.PR math.ST stat.TH


title:
On the dual variable of the Cauchy stress tensor in isotropic finite
  hyperelasticity

abstract:
  If the constitutive law linking the second Piola-Kirchhoff stress tensor and
the right Cauchy-Green strain tensor derives from a potential, then the Cauchy
stress tensor and the logarithm of the left Cauchy-Green strain tensor are
linked by a related potential. We give a new and concise proof which is based
on an explicit formula expressing the derivative of the exponential of a
tensor.


title:
Degenerate principal series representations and their holomorphic
  extensions

abstract:
  Let $X=H/L$ be an irreducible real bounded symmetric domain realized as a
real form in an Hermitian symmetric domain $D=G/K$. The intersection $S$ of the
  Shilov boundary of $D$ with $X$ defines a distinguished subset of the
topological boundary of $X$ and is invariant under $H$ and can also be realized
as $S=H/P$ for certain parabolic subgroup $P$ of $H$. We study the spherical
representations $Ind_P^H(\lam)$ of $H$ induced from $P$. We find formulas for
the spherical functions in terms of the Macdonald ${}_2F_1$ hypergeometric
function. This generalizes the earlier result of Faraut-Koranyi for Hermitian
symmetric spaces $D$. We consider a class of $H$-invariant integral
intertwining operators from the representations $Ind_P^H(\lam)$ on $L^2(S)$ to
the holomorphic representations of $G$ on $D$ restricted to $H$. We construct a
new class of complementary series for the groups $H=SO(n, m)$, $SU(n, m)$ (with
$n-m >2$) and $Sp(n, m)$ (with $n-m>1$). We realize them as a discrete
component in the branching rule of the analytic continuation of the holomorphic
discrete series of $G=SU(n, m)$, $SU(n, m)\times SU(n, m)$ and $SU(2n, 2m)$
respectively.


title: The very long range nature of capillary interactions in liquid films

abstract:
  Micron-sized objects confined in thin liquid films interact through forces
mediated by the deformed liquid-air interface. This capillary interactions
provide a powerful driving mechanism for the self-assembly of ordered
structures such as photonic materials or protein crystals. Direct probing of
capillary interactions requires a controlled force field to independently
manipulate small objects while avoiding any physical contact with the
interface. We demonstrate how optical micro-manipulation allows the direct
measurement of capillary interactions between two micron sized spheres in a
free standing liquid film. The force falls off as an inverse power law in
particles separation. We derive and validate an explicit expression for this
exponent whose magnitude is mainly governed by particles size. For micron-sized
objects we found an exponent close to, but smaller than one, making capillary
interactions a unique example of strong and very long ranged forces in the
mesoscopic world.


title:
A Dual Gate Spin Field Effect Transistor With Very Low Switching Voltage
  and Large ON-to-OFF Conductance Ratio

abstract:
  We propose and analyze a novel dual-gate Spin Field Effect Transistor
(SpinFET) with half-metallic ferromagnetic source and drain contacts. The
transistor has two gate pads that can be biased independently. It can be
switched ON or OFF with a few mV change in the differential bias between the
two pads, resulting in extremely low dynamic power dissipation during
switching. The ratio of ON to OFF conductance remains fairly large (~ 60) up to
a temperature of 10 K. This device also has excellent inverter characteristics,
making it attractive for applications in low power and high density Boolean
logic circuits.


title: Dynamical creation of bosonic Cooper-like pairs

abstract:
  We propose a scheme to create a metastable state of paired bosonic atoms in
an optical lattice. The most salient features of this state are that the
wavefunction of each pair is a Bell state and that the pair size spans half the
lattice, similar to fermionic Cooper pairs. This mesoscopic state can be
created with a dynamical process that involves crossing a quantum phase
transition and which is supported by the symmetries of the physical system. We
characterize the final state by means of a measurable two-particle correlator
that detects both the presence of the pairs and their size.


title: Geometry and Topology in Hamiltonian Dynamics and Statistical Mechanics

abstract:
  This submission has been withdrawn by arXiv administrators because it is
incomplete and thus violates arXiv policy.


title: Understanding the Charged Meson Z(4430)

abstract:
  The difference between Z(4430) as a $D^{*}D_1$ molecule and a tetraquark
state and how to distinguish between them are discussed. We construct an
effective Lagrangian with $D^{*}D_1$ contact interactions constrained by the
heavy quark symmetry and chiral symmetry to study Z(4430). We find that if
Z(4430) is a $D^{*}D_1$ molecule state, there should be a $B^{*}B_1$ bound
state as well, and it mass is about 11048.6 MeV.


title: Fundamental Conditions for N-th Order Accurate Lattice Boltzmann Models

abstract:
  In this paper, we theoretically prove a set of fundamental conditions
pertaining discrete velocity sets and corresponding weights. These conditions
provide sufficient conditions for a priori formulation of lattice Boltzmann
models that automatically admit correct hydrodynamic moments up to any given
N-th order.


title:
Osculating spaces and diophantine equations (with an appendix by Pietro
  Corvaja and Umberto Zannier)

abstract:
  This paper deals with some classical problems about the projective geometry
of complex algebraic curves. We call \textit{locally toric} a projective curve
that in a neighbourhood of every point has a local analytical parametrization
of type $(t^{a_1},...,t^{a_n})$, with $a_1,..., a_n$ relatively prime positive
integers. In this paper we prove that the general tangent line to a locally
toric curve in $\bP^3$ meets the curve only at the point of tangency. This
result extends and simplifies those of the paper \cite{kaji} by H.Kaji where
the same result is proven for any curve in $\bP^3$ such that every branch is
smooth. More generally, under mild hypotesis, up to a finite number of
anomalous parametrizations $(t^{a_1},...,t^{a_n})$, the general osculating
2-space to a locally toric curve of genus $g<2$ in $\bP^4$ does not meet the
curve again. The arithmetic part of the proof of this result relies on the
Appendix \cite{cz:rk} to this paper. By means of the same methods we give some
applications and we propose possible further developments.


title:
Theoretical study on isotopic shift in angle-resolved photoemission
  spectra of Bi2Sr2CaCu2O8

abstract:
  We develop a path-integral theory to study the angle-resolved photoemission
spectra (ARPES) of high-T_c superconductors based on a two-dimensional model
for the CuO2 conduction plane, including both electron-electron (e-e) and
electron-phonon (e-ph) interactions. Comparing our result with the experimental
one of Bi2Sr2CaCu2O8, we find that the experimentally observed isotopic band
shift in ARPES is due to the off-diagonal quadratic e-ph coupling, whereas the
presence of e-e repulsion partially suppresses this effect.


title:
Controlling spatiotemporal chaos in excitable media using an array of
  control points

abstract:
  The dynamics of activation waves in excitable media can give rise to spiral
turbulence, the resulting spatiotemporal chaos being associated with empirical
biological phenomena such as life-threatening disturbances in the natural
rhythm of the heart. In this paper, we propose a spatially extended but
non-global scheme using an array of control points for terminating such
spatiotemporally chaotic excitations. A low-amplitude control signal is applied
sequentially at each point on the array, resulting in a traveling wave of
excitation in the underlying medium which drives away the turbulent activity.
Our method is robust even in the presence of significant heterogeneities in the
medium, which have often been an impediment to the success of other control
schemes.


title: Summary of SLAC'S SEY Measurement On Flat Accelerator Wall Materials

abstract:
  The electron cloud effect (ECE) causes beam instabilities in accelerator
structures with intense positively charged bunched beams. Reduction of the
secondary electron yield (SEY) of the beam pipe inner wall is effective in
controlling cloud formation. We summarize SEY results obtained from flat TiN,
TiZrV and Al surfaces carried out in a laboratory environment. SEY was measured
after thermal conditioning, as well as after low energy, less than 300 eV,
particle exposure.


title:
Integral-field spectroscopy of a Lyman-Break Galaxy at z=3.2: evidence
  for merging

abstract:
  We present spatially-resolved, rest-frame optical spectroscopy of a z~3
Lyman-break galaxy (LBG), Q0347-383 C5, obtained with SINFONI on the VLT. This
galaxy, among the ~10% brightest LBGs, is only the second z~3 LBG observed with
an integral-field spectrograph. It was first described by Pettini et al.
(2001), who obtained WFPC2 F702W imaging and longslit spectroscopy in the
K-band. We find that the emission line morphology is dominated by two
unresolved blobs at a projected distance of ~5 kpc with a velocity offset of
~33 km s^-1. Velocity dispersions suggest that each blob has a mass of ~10^10
M_sun. Unlike Pettini et al. (2001), our spectra are deep enough to detect
H-beta, and we derive star-formation rates of ~20-40 M_sun yr^-1, and use the
H-beta/[OIII] ratio to crudely estimate an oxygen abundance 12+[O/H]=7.9-8.6,
which is in the range typically observed for LBGs. We compare the properties of
Q0347-383 C5 with what is found for other LBGs, including the gravitationally
lensed ``arc+core'' galaxy (Nesvadba et al. 2006), and discuss possible
scenarios for the nature of the source, namely disk rotation, a
starburst-driven wind, disk fragmentation, and merging of two LBGs. We favor
the merging interpretation or bright, extended LBGs like Q0347-383C5, in broad
agreement with predicted merger rates from hierarchical models.


title: Persistent Current for a genus g=2 structure

abstract:
  We report the first calculation of persistent current in two coupled rings
which form a character ``8'' genus g=2 structure. We obtain an exact solution
for the persistent current and investigated the exact solution numerically. For
two large coupled rings with equal fluxes, we find that the persistent current
in the two coupled rings is equal to that in a single ring. For opposite fluxes
the energy has a chaotic structure. For both cases the periodicity is $h/e$.
This results are obtained within an extension of Dirac's second class method to
fermionic constraints. This theory can be tested in the ballistic regime.


title:
The role of minor mergers in the recent star formation history of
  early-type galaxies

abstract:
  We demonstrate that the large scatter in the ultra-violet (UV) colours of
intermediate-mass early-type galaxies in the local Universe and the inferred
low-level recent star formation in these objects can be reproduced by minor
mergers in the standard LCDM cosmology. Numerical simulations of mergers with
mass ratios less than or equal to 1:4, with reasonable assumptions for the
ages, metallicities and dust properties of the merger progenitors, produce good
agreement to the observed UV colours of the early-type population, if the
infalling satellites are assumed to have (cold) gas fractions greater than 20%.
Early-types that satisfy (NUV-r) < 3.8 are likely to have experienced mergers
with mass ratios between 1:4 and 1:6 within the last ~1.5 Gyrs, while those
that satisfy 3.8<(NUV-r)<5.5 are consistent with either recent mergers with
mass ratios < 1:6 or mergers with higher mass ratios that occurred more than
~1.5 Gyrs in the past. We demonstrate that the early-type colour-magnitude
relations and colour distributions in both the UV and optical spectral ranges
are consistent with the expected frequency of minor merging activity in the
standard LCDM cosmology at low redshift. We present a strong plausibility
argument for minor mergers to be the principal mechanism behind the large UV
scatter and associated low-level recent star formation observed in early-type
galaxies in the nearby Universe.


title: Rings graded equivalent to the Weyl algebra

abstract:
  We consider the first Weyl algebra, A, in the Euler gradation, and completely
classify graded rings B that are graded equivalent to A: that is, the
categories gr-A and gr-B are equivalent. This includes some surprising
examples: in particular, we show that A is graded equivalent to an idealizer in
a localization of A. We obtain this classification as an application of a
general Morita-type characterization of equivalences of graded module
categories.


title:
V838 Monocerotis: A Geometric Distance from Hubble Space Telescope
  Polarimetric Imaging of its Light Echo

abstract:
  Following the outburst of the unusual variable star V838 Monocerotis in 2002,
a spectacular light echo appeared. A light echo provides the possibility of
direct geometric distance determination, because it should contain a ring of
highly linearly polarized light at a linear radius of ct, where t is the time
since the outburst. We present imaging polarimetry of the V838 Mon light echo,
obtained in 2002 and 2005 with the Advanced Camera for Surveys onboard the
Hubble Space Telescope, which confirms the presence of the highly polarized
ring. Based on detailed modeling that takes into account the outburst light
curve, the paraboloidal echo geometry, and the physics of dust scattering and
polarization, we find a distance of 6.1+-0.6 kpc. The error is dominated by the
systematic uncertainty in the scattering angle of maximum linear polarization,
taken to be theta_{max}=90^o +- 5^o. The polarimetric distance agrees
remarkably well with a distance of 6.2+-1.5 kpc obtained from the entirely
independent method of main-sequence fitting to a sparse star cluster associated
with V838 Mon. At this distance, V838 Mon at maximum light had M_V\simeq-9.8,
making it temporarily one of the most luminous stars in the Local Group. Our
validation of the polarimetric method offers promise for measurement of
extragalactic distances using supernova light echoes.


title: Mass gap in the 2D O(3) non-linear sigma model with a theta=pi term

abstract:
  By analytic continuation to real theta of data obtained from numerical
simulation at imaginary theta we study the Haldane conjecture and show that the
O(3) non-linear sigma model with a theta term in 2 dimensions becomes massless
at theta=3.10(5). A modified cluster algorithm has been introduced to simulate
the model with imaginary theta. Two different definitions of the topological
charge on the lattice have been used; one of them needs renormalization to
match the continuum operator. Our work also offers a successful test for
numerical methods based on analytic continuation.


title:
Chirality and $Z_2$ vortices in an Heisenberg spin model on the kagom\'e
  lattice

abstract:
  The phase diagram of the classical \jj model on the \kag lattice is
investigated using extensive \mc simulations. In a realistic range of
parameters, this model has a low-temperature chiral-ordered phase without
long-range spin order. We show that the critical transition marking the
destruction of chiral order is preempted by the first order proliferation of
\Zdeux point defects. The core energy of these vortices appears to vanish when
approaching the T=0 phase boundary, where both \Zdeux defects and gapless
magnons contribute to disordering the system at very low temperature. This
situation might be typical of a large class of frustrated magnets. Possible
relevance for real materials is also discussed.


title:
Magnetic field amplification in proto-neutron stars -- The role of the
  neutron-finger instability for dynamo excitation

abstract:
  During the first 40 s after their birth, proto-neutron stars are expected to
be subject to at least two types of instability: the convective instability and
the neutron-finger one. Both instabilities involve convective motions and hence
can trigger dynamo actions which may be responsible for the large magnetic
fields in neutron stars and magnetars. We have solved the mean-field induction
equation in a simplified one-dimensional model of both the convective and the
neutron-finger instability zones. Although very idealized, the model includes
the nonlinearities introduced by the feedback processes which tend to saturate
the growth of the magnetic field (alpha-quenching) and suppress its turbulent
diffusion (eta-quenching). The possibility of a dynamo action is studied within
a dynamical model of turbulent diffusivity where the boundary of the unstable
zone is allowed to move. We show that the dynamo action can be operative and
that the amplification of the magnetic field can still be very effective.
Furthermore, we confirm the existence of a critical spin-period, below which
the dynamo is always excited independently of the degree of differential
rotation, and whose value is related to the size of the neutron-finger
instability zone. Finally we provide a relation for the intensity of the final
field as a function of the spin of the star and of its differential rotation.
Although they were obtained by using a toy model, we expect that our results
are able to capture the qualitative and asymptotic behaviour of a mean-field
dynamo action developing in the neutron-finger instability zone. Overall, we
find that such a dynamo is very efficient in producing magnetic fields well
above equipartition and thus that it could represent a possible explanation for
the large surface magnetic fields observed in neutron stars.


title:
Emission spectra of atoms with non-Markovian interaction: Fluorescence
  in a photonic crystal

abstract:
  We present a formula to evaluate the spontaneous emission spectra of an atom
in contact with a radiation field with non-Markovian effects. This formula is
written in terms of a two-time correlation of system observables and the
environmental correlation function, and depends on the distance between the
emitting atom and the detector. As an example, we use it to analyze the
fluorescence spectra of a two level atom placed as an impurity in a photonic
crystal. The radiation field within those materials has a gap or discontinuity
where electromagnetic modes cannot propagate in the stationary limit. In that
situation, the atomic emission occurs in the form of evanescent waves which are
detected with less efficiency the farther we place the detector. The
methodology presented in this paper may be useful to study the non-Markovian
dynamics of any quantum open system in linear interaction with a harmonic
oscillator reservoir and within the weak coupling approximation.


title: Quantum Monte Carlo Calculations of Light Nuclei

abstract:
  During the last 15 years, there has been much progress in defining the
nuclear Hamiltonian and applying quantum Monte Carlo methods to the calculation
of light nuclei. I describe both aspects of this work and some recent results.


title: On the phase dependence of a reversed quantum transitions

abstract: Physical nature of widely known Ramsey fringes phenomenon is discussed.


title: On the origin of the lightest Molybdenum isotopes

abstract:
  We discuss implications of recent precision measurements for the Rh93 proton
separation energy for the production of the lightest molybdenum isotopes in
proton-rich type II supernova ejecta. It has recently been shown that a novel
neutrino-induced process makes these ejecta a promising site for the production
of the light molybdenum isotopes and other "p-nuclei" with atomic mass near
100. The origin of these isotopes has long been uncertain. A distinguishing
feature of nucleosynthesis in neutrino-irradiated outflows is that the relative
production of Mo92 and Mo94 is set by a competition governed by the proton
separation energy of Rh93. We use detailed nuclear network calculations and the
recent experimental results for this proton separation energy to place
constraints on the outflow characteristics that produce the lightest molybdenum
isotopes in their solar proportions. It is found that for the conditions
calculated in recent two-dimensional supernova simulations, and also for a
large range of outflow characteristics around these conditions, the solar ratio
of Mo92 to Mo94 cannot be achieved. This suggests that either proton-rich winds
from type II supernova do not exclusively produce both isotopes, or that these
winds are qualitatively different than calculated in today's supernova models.


title:
Random matrix models for decoherence and fidelity decay in quantum
  information systems

abstract:
  This course aims to introduce the student to random matrix models for
decoherence and fidelity decay. They present a very powerful alternate
approach, that emphasizes the disordered character of many environments and
uncontrollable perturbations/couplings. The inherent integrability of such
models makes analytic studies possible. We limit our considerations to linear
response treatment, as high fidelity and small decoherence are the backbone of
quantum information processes. For fidelity decay, where experimental results
are available, a comparison with experiments shows excellent agreement with
random matrix theory predictions.


title:
Superconductivity and topological Fermi surface transitions in
  electron-doped cuprates near optimal doping

abstract:
  We discuss evolution of the Fermi surface (FS) topology with doping in
electron doped cuprates within the framework of a one-band Hubbard Hamiltonian,
where antiferromagnetism and superconductivity are assumed to coexist in a
uniform phase. In the lightly doped insulator, the FS consists of electron
pockets around the $(\pi,0)$ points. The first change in the FS topology occurs
in the optimally doped region when an additional hole pocket appears at the
nodal point. The second change in topology takes place in the overdoped regime
($\sim18%$) where antiferromagnetism disappears and a large
$(\pi,\pi)$-centered metallic FS is formed. Evidence for these two topological
transitions is found in recent Hall effect and penetration depth experiments on
Pr$_{2-x}$Ce$_{x}$CuO$_{4-\delta}$ (PCCO) and with a number of spectroscopic
measurements on Nd$_{2-x}$Ce$_{x}$CuO$_{4-\delta}$ (NCCO).


title: From Hopf to Neimark-Sacker bifurcation: a computational algorithm

abstract:
  We construct an algorithm for approximating the invariant tori created at a
Neimark-Sacker bifurcation point. It is based on the same philosophy as many
algorithms for approximating the periodic orbits created at a Hopf bifurcation
point, i.e. a Fourier spectral method. For Neimark-Sacker bifurcation, however,
we use a simple parametrisation of the tori in order to determine low-order
approximations, and then utilise the information contained therein to develop a
more general parametrisation suitable for computing higher-order
approximations. Different algorithms, applicable to either autonomous or
periodically-forced systems of differential equations, are obtained.


title: Unparticle Dark Matter

abstract:
  Once a parity is introduced in unparticle physics, under which unparticle
provided in a hidden conformal sector is odd while all Standard Model particles
are even, unparticle can be a suitable candidate for the cold dark matter (CDM)
in the present universe through its coupling to the Standard Model Higgs
doublet. We find that for Higgs boson mass in the range, 114.4 GeV < m_h < 250
GeV, the relic abundance of unparticle with mass 50 GeV < m_U < 80 GeV can be
consistent with the currently observed CDM density. In this scenario, Higgs
boson with mass m_h < 160 GeV dominantly decays into a pair of unparticles and
such an invisible Higgs boson may be discovered in future collider experiments.


title:
Inhomogeneous Coupling in Two-Channel Asymmetric Simple Exclusion
  Processes

abstract:
  Asymmetric exclusion processes for particles moving on parallel channels with
inhomogeneous coupling are investigated theoretically. Particles interact with
hard-core exclusion and move in the same direction on both lattices, while
transitions between the channels is allowed at one specific location in the
bulk of the system. An approximate theoretical approach that describes the
dynamics in the vertical link and horizontal lattice segments exactly but
neglects the correlation between the horizontal and vertical transport is
developed. It allows us to calculate stationary phase diagrams, particle
currents and densities for symmetric and asymmetric transitions between the
channels. It is shown that in the case of the symmetric coupling there are
three stationary phases, similarly to the case of single-channel totally
asymmetric exclusion processes with local inhomogeneity. However, the
asymmetric coupling between the lattices lead to a very complex phase diagram
with ten stationary-state regimes. Extensive Monte Carlo computer simulations
generally support theoretical predictions, although simulated stationary-state
properties slightly deviate from calculated in the mean-field approximation,
suggesting the importance of correlations in the system. Dynamic properties and
phase diagrams are discussed by analyzing constraints on the particle currents
across the channels.


title: Aharonov-Bohm effect in graphene

abstract:
  We investigate experimentally transport through ring-shaped devices etched in
graphene and observe clear Aharonov-Bohm conductance oscillations. The
temperature dependence of the oscillation amplitude indicates that below 1 K
the phase coherence length is comparable to or larger than the size of the
ring. An increase in the amplitude is observed at high magnetic field, when the
cyclotron diameter becomes comparable to the width of the arms of the ring. By
measuring the dependence on gate voltage, we also observe an unexpected linear
dependence of the oscillation amplitude on the ring conductance, which had not
been reported earlier in rings made using conventional metals or semiconducting
heterostructures.


title:
Study of a model-independent method for the measurement of the angle
  phi_3

abstract:
  This report shows the latest results on the study of the method to determine
the angle phi_3 of the unitarity triangle using Dalitz plot analysis of $D^0$
decay from B->DK process in a model-independent way. We concentrate on the case
with a limited charm data sample, which will be available from the CLEO-c
collaboration in the nearest future, with the main goal to find the optimal
strategy for phi_3 extraction. We find that the analysis using decays of D_CP
only cannot provide a completely model-independent measurement in the case of
limited data sample. The procedure involving binned analysis of B->DK and
psi(3770)->(K^0_S pi^+ pi^-)_D(K^0_S pi^+ pi^-)_D decays is proposed, that
allows to obtain the phi_3 precision comparable to unbinned model-dependent
fit.


title:
Diverging thermal expansion of the spin-ladder system
  (C$_5$H$_{12}$N)$_2$CuBr$_4$

abstract:
  We present high-resolution measurements of the $c^\star$-axis thermal
expansion and magnetostriction of piperidinium copper bromide \hp. The
experimental data at low temperatures is well accounted for by a two-leg
spin-ladder Hamiltonian. The thermal expansion shows a complex behaviour with
various sign changes and approaches a $1/\sqrt{T}$ divergence at the critical
fields. All low-temperature features are semi-quantitatively explained within a
free fermion model; full quantitative agreement is obtained with Quantum Monte
Carlo simulations.


title: Sensitivities of Future Long Baseline Experiments in the US

abstract:
  Sensitivities to neutrino oscillation parameters for possible very long
baseline neutrino oscillation experiments are discussed. The reach for
observing a non-zero mixing angle $\theta_{13}$, establishing CP violation and
determining the mass hierarchy are compared between various experimental
options. Different possibilities for neutrino beams are briefly described, as
well as the assumptions about the performance of a large water Cherenkov and
liquid Argon detector.


title: Assouad-Nagata dimension of locally finite groups and asymptotic cones

abstract:
  In this work we study two problems about Assouad-Nagata dimension:
  1) Is there a metric space of non zero Assouad-Nagata dimension such that all
of its asymptotic cones are of Assouad-Nagata dimension zero? (Dydak and Higes)
  2) Suppose $G$ is a locally finite group with a proper left invariant metric
$d_G$. If $\dim_{AN}(G, d_G)>0$, is $\dim_{AN} (G, d_G)$ infinite? (Brodskiy,
Dydak and Lang)
  The first question is answered positively not only for general metric spaces
but also for discrete groups with proper left invariant metrics.
  The second question has a negative solution. We show that for each $n$ there
exists a locally finite group of Assouad-Nagata dimension $n$. A generalization
to countable groups of arbitrary asymptotic dimension is given


title:
Interference versus success probability in quantum algorithms with
  imperfections

abstract:
  We study the influence of errors and decoherence on both the performance of
Shor's factoring algorithm and Grover's search algorithm, and on the amount of
interference in these algorithms using a recently proposed interference
measure. We consider systematic unitary errors, random unitary errors, and
decoherence processes. We show that unitary errors which destroy the
interference destroy the efficiency of the algorithm, too. However, unitary
errors may also create useless additional interference. In such a case the
total amount of interference can increase, while the efficiency of the quantum
computation decreases. For decoherence due to phase flip errors, interference
is destroyed for small error probabilities, and converted into destructive
interference for error probabilities approaching one, leading to success
probabilities which can even drop below the classical value. Our results show
that in general interference is necessary in order for a quantum algorithm to
outperform classical computation, but large amounts of interference are not
sufficient and can even lead to destructive interference with worse than
classical success rates.


title: Challenges to Path Integral Formulations of Quantum Theories

abstract:
  The functional integral has many triumphs in elucidating quantum theory. But
incorporating charge fractionalization into that formalism remains a challenge.


title:
Spitzer Observations of the HII Region NGC 2467: An Analysis of
  Triggered Star Formation

abstract:
  We present new Spitzer Space Telescope observations of the region NGC 2467,
and use these observations to determine how the environment of an HII region
affects the process of star formation. Our observations comprise IRAC (3.6,
4.5, 5.8, and 8.0 um) and MIPS (24 um) maps of the region, covering
approximately 400 square arcminutes. The images show a region of ionized gas
pushing out into the surrounding molecular cloud, powered by an O6V star and
two clusters of massive stars in the region. We have identified as candidate
Young Stellar Objects (YSOs) 45 sources in NGC 2467 with infrared excesses in
at least two mid-infrared colors. We have constructed color-color diagrams of
these sources and have quantified their spatial distribution within the region.
We find that the YSOs are not randomly distributed in NGC 2467; rather, over
75% of the sources are distributed at the edge of the HII region, along
ionization fronts driven by the nearby massive stars. The high fraction of YSOs
in NGC 2467 that are found in proximity to gas that has been compressed by
ionization fronts supports the hypothesis that a significant fraction of the
star formation in NGC 2467 is triggered by the massive stars and the expansion
of the HII region. At the current rate of star formation, we estimate at least
25-50% of the total population of YSOs formed by this process.


title: Selective screenability and the Hurewicz property

abstract:
  We characterize the Hurewicz covering property in metrizable spaces in terms
of properties of the metrics of the space. Then we show that a weak version of
selective screenability, when combined with the Hurewicz property, implies
selective screenability.


title: Combinatorial polar orderings and recursively orderable arrangements

abstract:
  Polar orderings arose in recent work of Salvetti and the second author on
minimal CW-complexes for complexified hyperplane arrangements. We study the
combinatorics of these orderings in the classical framework of oriented
matroids, and reach thereby a weakening of the conditions required to actually
determine such orderings. A class of arrangements for which the construction of
the minimal complex is particularly easy, called {\em recursively orderable}
arrangements, can therefore be combinatorially defined. We initiate the study
of this class, giving a complete characterization in dimension 2 and proving
that every supersolvable complexified arrangement is recursively orderable.


title: Constraints on the Magnetic Field Geometry of Magnetars

abstract:
  We study the effect of the magnetic field geometry on the oscillation spectra
of strongly magnetized stars. The magnetic field distributions include both
toroidal and poloidal contributions. We observe that the toroidal contribution
does not influence significantly the torsional oscillations of the crust.
Moreover, in the case that the core is a type I supercontactor and the magnetic
fields are confined in the crust, the torsional oscillation spectrum is
drastically affected by the presence of the strong magnetic fields. Comparison
with results and estimations for the magnetic field strength, from
observations, exclude the possibility that magnetars will have a magnetic field
solely confined in the crust i.e. our results suggest that the magnetic field
in whatever geometry has to permeate the whole star.


title:
A Comparison of the Variability of the Symbiotic X-ray Binaries GX 1+4,
  4U 1954+31, and 4U 1700+24 from Swift/BAT and RXTE/ASM Observations

abstract:
  We present an analysis of the X-ray variability of three symbiotic X-ray
binaries, GX 1+4, 4U 1700+24, and 4U 1954+31, using observations made with the
Swift Burst Alert Telescope (BAT) and the Rossi X-ray Timing Explorer (RXTE)
All-Sky Monitor (ASM). Observations of 4U 1954+31 with the Swift BAT show
modulation at a period near 5 hours. Models to explain this modulation are
discussed including the presence of an exceptionally slow X-ray pulsar in the
system and accretion instabilities. We conclude that the most likely
interpretation is that 4U 1954+31 contains one of the slowest known X-ray
pulsars. Unlike 4U 1954+31, neither GX 1+4 nor 4U 1700+24 show any evidence for
modulation on a timescale of hours. An analysis of the RXTE ASM light curves of
GX 1+4, 4U 1700+24, and 4U 1954+31 does not show the presence of periodic
modulation in any source, although there is considerable variability on long
timescales for all three sources. There is no modulation in GX 1+4 on either
the optical 1161 day orbital period or a previously reported 304 day X-ray
period. For 4U 1700+24 we do not confirm the 404 day X-ray period previously
proposed for this source from a shorter duration ASM light curve. We conclude
that all three sources have substantial low-frequency noise in their power
spectra that may give the appearance of periodic modulation if this noise is
not properly accounted for, particularly if short duration light curves are
examined.


title: Manin's conjecture on toric varieties with different heights

abstract:
  In this paper I verify Manin's conjecture for a class of rational projective
toric varieties with a large class of heights other than the usual one that
comes from the standard metric on projective space.


title:
The nature of HHL 73 from optical imaging and Integral Field
  Spectroscopy

abstract:
  We present new results on the nature of the Herbig-Haro-like object 73
(HHL73, also known as [G84b] 11) based on narrow-band CCD H_alpha and [SII]
images of the HHL73 field, and Integral Field Spectroscopy and radio continuum
observations at 3.6 cm covering the emission of the HHL 73 object. The CCD
images allow us to resolve the HHL 73 comet-shaped morphology into two
components and a collimated emission feature of ~4" long, reminiscent of a
microjet. The IFS spectra of HHL 73 showed emission lines characteristic of the
spectra of Herbig--Haro objects. The kinematics derived for HHL~73 are complex.
The profiles of the [SII] lambda6717, 6731AA lines were well fitted with a
model of three Gaussian velocity components peaking at -100, -20 and +35 km/s.
We found differences among the spatial distribution of the kinematic components
that are compatible with the emission from a bipolar outflow with two
blueshifted (low- and high-velocity) components. Extended radio continuum
emission at 3.6 cm was detected showing a distribution in close agreement with
the HHL~73 redshifted gas. From the results discussed here, we propose HHL 73
to be a true HH object. IRAS 21432+4719, offset 30 arcsec northeast from the
HHL 73 apex, is the most plausible candidate to be driving HHL 73, although the
evidence is not conclusive.


title:
Chaotic Gene Regulatory Networks Can Be Robust Against Mutations and
  Noise

abstract:
  Robustness to mutations and noise has been shown to evolve through
stabilizing selection for optimal phenotypes in model gene regulatory networks.
The ability to evolve robust mutants is known to depend on the network
architecture. How do the dynamical properties and state-space structures of
networks with high and low robustness differ? Does selection operate on the
global dynamical behavior of the networks? What kind of state-space structures
are favored by selection? We provide damage propagation analysis and an
extensive statistical analysis of state spaces of these model networks to show
that the change in their dynamical properties due to stabilizing selection for
optimal phenotypes is minor. Most notably, the networks that are most robust to
both mutations and noise are highly chaotic. Certain properties of chaotic
networks, such as being able to produce large attractor basins, can be useful
for maintaining a stable gene-expression pattern. Our findings indicate that
conventional measures of stability, such as the damage-propagation rate, do not
provide much information about robustness to mutations or noise in model gene
regulatory networks.


title: MANX: A 6D Ionization-Cooling Experiment

abstract:
  Six-dimensional ionization cooling of muons is essential for muon colliders
and possibly beneficial for neutrino factories. An experiment to demonstrate
six-dimensional ionization cooling using practical apparatus is presented. It
exploits recent innovative ideas that may lead to six-dimensional muon-cooling
channels with emittance reduction approaching that needed for high-luminosity
muon colliders.


title: Integrable systems from membranes on AdS_4 x S^7

abstract:
  We describe how Neumann and Neumann-Rosochatius type integrable systems, as
well as the continuous limit of the SU(2) integrable spin chain, can be
obtained from membranes on AdS_4 x S^7 background, in the framework of AdS/CFT
correspondence.


title: Duality and Braiding in Twisted Quantum Field Theory

abstract:
  We re-examine various issues surrounding the definition of twisted quantum
field theories on flat noncommutative spaces. We propose an interpretation
based on nonlocal commutative field redefinitions which clarifies previously
observed properties such as the formal equivalence of Green's functions in the
noncommutative and commutative theories, causality, and the absence of UV/IR
mixing. We use these fields to define the functional integral formulation of
twisted quantum field theory. We exploit techniques from braided tensor algebra
to argue that the twisted Fock space states of these free fields obey
conventional statistics. We support our claims with a detailed analysis of the
modifications induced in the presence of background magnetic fields, which
induces additional twists by magnetic translation operators and alters the
effective noncommutative geometry seen by the twisted quantum fields. When two
such field theories are dual to one another, we demonstrate that only our
braided physical states are covariant under the duality.


title:
Orbital Parameters and Chemical Composition of Four White Dwarfs in
  Post-Common Envelope Binaries

abstract:
  We present FUSE observations of the hot white dwarfs in the post-common
envelope binaries Feige 24, EUVE J0720-317, BPM 6502, and EUVE J2013+400. The
spectra show numerous photospheric absorption lines which trace the white dwarf
orbital motion. We report the detection of C III, O VI, P V, and Si IV in the
spectra of Feige 24, EUVE J0720-317 and EUVE J2013+400, and the detection of C
III, N II, Si III, Si IV, and Fe III in the spectra of BPM 6502. Abundance
measurements support the possibility that white dwarfs in post-common envelope
binaries accrete material from the secondary star wind. The FUSE observations
of BPM 6502 and EUVE J2013+400 cover a complete binary orbit. We used the FUSE
spectra to measure the radial velocities traced by the white dwarf in the four
binaries, where the zero-point velocity were fixed using the ISM velocities in
the line of sight of the stellar systems. For BPM 6502 we determined a white
dwarf velocity semi-amplitude of K_WD = 18.6+/-0.5km/s, and with the velocity
semi-amplitude of the red dwarf companion (K_RD = 75.2+/-3.1 km/s), we estimate
the mass ratio to be q = 0.25+/-0.01. Adopting a spectroscopic mass
determination for the white dwarf, we infer a low secondary mass of M_RD =
0.14+/-0.01 M_solar. For EUVE J2013+400 we determine a white dwarf velocity
semi-amplitude of K_WD = 36.7+/-0.7 km/s. The FUSE observations of EUVE
J0720-317 cover approximately 30% of the binary period and combined with the
HST GHRS measurements (Vennes et al. 1999, ApJ 523, 386), we update the binary
properties. FUSE observations of Feige 24 cover approximately 60% of the orbit
and we combine this data set with HST STIS (Vennes et al. 2000, ApJ, 544, 423)
data to update the binary properties.


title:
The non-equilibrium response of the critical Ising model: Universal
  scaling properties and Local Scale Invariance

abstract:
  Motivated by recent numerical findings [M. Henkel, T. Enss, and M. Pleimling,
J. Phys. A: Math. Gen. 39 (2006) L589] we re-examine via Monte Carlo
simulations the linear response function of the two-dimensional Ising model
with Glauber dynamics quenched to the critical point. At variance with the
results of Henkel et al., we detect discrepancies between the actual scaling
behavior of the response function and the prediction of Local Scale Invariance.
Such differences are clearly visible in the impulse autoresponse function,
whereas they are drastically reduced in integrated response functions.
Accordingly, the scaling form predicted on the basis of Local Scale Invariance
simply provides an accurate fitting form for some quantities but cannot be
considered to be exact.


title:
Structural, elastic and electronic properties of Fe3C from
  first-principles

abstract:
  Using first-principles calculations within the generalized gradient
approximation, we predicted the lattice parameters, elastic constants,
vibrational properties, and electronic structure of cementite (Fe3C). Its nine
single-crystal elastic constants were obtained by computing total energies or
stresses as a function of applied strain. Furthermore, six of them were
determined from the initial slopes of the calculated longitudinal and
transverse acoustic phonon branches along the [100], [010] and [001]
directions. The three methods agree well with each other, the calculated
polycrystalline elastic moduli are also in good overall agreement with
experiments. Our calculations indicate that Fe3C is mechanically stable. The
experimentally observed high elastic anisotropy of Fe3C is also confirmed by
our study. Based on electronic density of states and charge density
distribution, the chemical bonding in Fe3C was analyzed and was found to
exhibit a complex mixture of metallic, covalent, and ionic characters.


title: Lawvere-Tierney sheaves in algebraic set theory

abstract:
  We present a solution to the problem of defining a counterpart in Algebraic
Set Theory of the construction of internal sheaves in Topos Theory. Our
approach is general in that we consider sheaves as determined by
Lawvere-Tierney coverages, rather than by Grothendieck coverages, and assume
only a weakening of the axioms for small maps originally introduced by Joyal
and Moerdijk, thus subsuming the existing topos-theoretic results.


title:
Evolution over Time of Magentic Dynamo Driven UV & X-ray Emissions of
  dG-M Stars and Effects on Hosted Planets

abstract:
  The evolution over time of the magnetic activity and the resulting X-ray and
UV coronal and chromospheric emissions of main-sequence dG, dK, and dM stars
with widely different ages are discussed. Young cool stars spin rapidly and
have correspondingly very robust magnetic dynamos and strong coronal and
chromospheric X-ray - UV (XUV) emissions. However, these stars spin-down with
time as they lose angular momentum via magnetized winds and their magnetic
generated activity and emissions significantly decrease. Studies of dK-dM stars
over a wide range of ages and rotations show similar (but not identical)
behavior. Particular emphasis is given to discussing the effects that XUV
emissions have on the atmospheres and evolution of solar system planets as well
as the increasing number of extrasolar planets found hosted by dG-dM stars. The
results from modeling the early atmospheres of Venus, Earth and Mars using
recently determined XUV irradiances and inferred winds of the young Sun are
also briefly discussed. For example, the loss of water from juvenile Venus and
Mars can be explained by action of the strong XUV emissions and robust winds of
the young Sun. We also examine the effects of strong X-ray and UV coronal and
chromospheric emissions (and frequent flares) that dM stars have on possible
planets orbiting within their shrunken habitable zones (HZs) - located close to
the low luminosity host stars (HZ < ~0.4 AU). Dwarf M stars make interesting
targets for further study because of their deep outer convective zones (CZs),
efficient dynamos, frequent flares and strong XUV emissions. Furthermore, a
large fraction of dM stars are very old (>5 Gyr), which present intriguing
possibilities for the development of highly advanced modes of intelligent life
on planets that may orbit them.


title:
Many-spinon states and representations of Yangians in the SU(n)
  Haldane--Shastry model

abstract:
  We study the relation of Yangians and spinons in the SU(n) Haldane--Shastry
model. The representation theory of the Yangian is shown to be intimately
related to the fractional statistics of the spinons. We construct the spinon
Hilbert space from tensor products of the fundamental representations of the
Yangian.


title: Spin glasses and algorithm benchmarks: A one-dimensional view

abstract:
  Spin glasses are paradigmatic models that deliver concepts relevant for a
variety of systems. However, rigorous analytical results are difficult to
obtain for spin-glass models, in particular for realistic short-range models.
Therefore large-scale numerical simulations are the tool of choice. Concepts
and algorithms derived from the study of spin glasses have been applied to
diverse fields in computer science and physics. In this work a one-dimensional
long-range spin-glass model with power-law interactions is discussed. The model
has the advantage over conventional systems in that by tuning the power-law
exponent of the interactions the effective space dimension can be changed thus
effectively allowing the study of large high-dimensional spin-glass systems to
address questions as diverse as the existence of an Almeida-Thouless line,
ultrametricity and chaos in short range spin glasses. Furthermore, because the
range of interactions can be changed, the model is a formidable test-bed for
optimization algorithms.


title: N3Logic: A Logical Framework For the World Wide Web

abstract:
  The Semantic Web drives towards the use of the Web for interacting with
logically interconnected data. Through knowledge models such as Resource
Description Framework (RDF), the Semantic Web provides a unifying
representation of richly structured data. Adding logic to the Web implies the
use of rules to make inferences, choose courses of action, and answer
questions. This logic must be powerful enough to describe complex properties of
objects but not so powerful that agents can be tricked by being asked to
consider a paradox. The Web has several characteristics that can lead to
problems when existing logics are used, in particular, the inconsistencies that
inevitably arise due to the openness of the Web, where anyone can assert
anything. N3Logic is a logic that allows rules to be expressed in a Web
environment. It extends RDF with syntax for nested graphs and quantified
variables and with predicates for implication and accessing resources on the
Web, and functions including cryptographic, string, math. The main goal of
N3Logic is to be a minimal extension to the RDF data model such that the same
language can be used for logic and data. In this paper, we describe N3Logic and
illustrate through examples why it is an appropriate logic for the Web.


title: A Hofer-like metric on the group of symplectic diffeomorphisms

abstract:
  Using a "Hodge decomposition" of symplectic isotopies on a compact symplectic
manifold $(M,\omega)$, we construct a norm on the identity component in the
group of all symplectic diffeomorphisms of $(M,\omega)$ whose restriction to
the group $Ham(M,\omega)$ of hamiltonian diffeomorphisms is bounded from above
by the Hofer norm. Moreover, $Ham(M,\omega)$ is closed in $Symp(M,\omega)$
equipped with the topology induced by the extended norm. We give an application
to the $C^0$ symplectic topology. We also discuss extensions of Oh's spectral
distance.


title: Elie Cartan's torsion in geometry and in field theory, an essay

abstract:
  We review the application of torsion in field theory. First we show how the
notion of torsion emerges in differential geometry. In the context of a Cartan
circuit, torsion is related to translations similar as curvature to rotations.
Cartan's investigations started by analyzing Einsteins general relativity
theory and by taking recourse to the theory of Cosserat continua. In these
continua, the points of which carry independent translational and rotational
degrees of freedom, there occur, besides ordinary (force) stresses,
additionally spin moment stresses. In a 3-dimensional continuized crystal with
dislocation lines, a linear connection can be introduced that takes the crystal
lattice structure as a basis for parallelism. Such a continuum has similar
properties as a Cosserat continuum, and the dislocation density is equal to the
torsion of this connection. Subsequently, these ideas are applied to
4-dimensional spacetime. A translational gauge theory of gravity is displayed
(in a Weitzenboeck or teleparallel spacetime) as well as the viable
Einstein-Cartan theory (in a Riemann-Cartan spacetime). In both theories, the
notion of torsion is contained in an essential way. Cartan's spiral staircase
is described as a 3-dimensional Euclidean model for a space with torsion, and
eventually some controversial points are discussed regarding the meaning of
torsion.


title: Group Extensions and Automorphism Group Rings

abstract:
  The group ring of the automorphism group of a p-group is studied using the
automorphism groups of subgroups and quotient groups of P.


title: Black Hole Formation and Growth: Simulations in General Relativity

abstract:
  Black holes are popping up all over the place: in compact binary X-ray
sources and GRBs, in quasars, AGNs and the cores of all bulge galaxies, in
binary black holes and binary black hole-neutron stars, and maybe even in the
LHC! Black holes are strong-field objects governed by Einstein's equations of
general relativity. Hence general relativistic, numerical simulations of
dynamical phenomena involving black holes may help reveal ways in which black
holes can form, grow and be detected in the universe. To convey the
state-of-the art, we summarize several representative simulations here,
including the collapse of a hypermassive neutron star to a black hole following
the merger of a binary neutron star, the magnetorotational collapse of a
massive star to a black hole, and the formation and growth of supermassive
black hole seeds by relativistic MHD accretion in the early universe.


title: Insulator-metal transition on the triangular lattice

abstract:
  Mott insulators with a half-filled band of electrons on the triangular
lattice have been recently studied in a variety of organic compounds. All of
these compounds undergo transitions to metallic/superconducting states under
moderate hydrostatic pressure. We describe the Mott insulator using its
hypothetical proximity to a Z_2 spin liquid of bosonic spinons. This spin
liquid has quantum phase transitions to descendant confining states with Neel
or valence bond solid order, and the insulator can be on either side of one of
these transitions. We present a theory of fermionic charged excitations in
these states, and describe the route to metallic states with Fermi surfaces. We
argue that an excitonic condensate can form near this insulator-metal
transition, due to the formation of charge neutral pairs of charge +e and
charge -e fermions. This condensate breaks the lattice space group symmetry,
and we propose its onset as an explanation of a low temperature anomaly in
kappa-(ET)2Cu2(CN)3. We also describe the separate BCS instability of the
metallic states to the pairing of like-charge fermions and the onset of
superconductivity.


title: Quantum-fluid dynamics of microcavity polaritons

abstract:
  Semiconductor microcavities offer a unique system to investigate the physics
of weakly interacting bosons. Their elementary excitations, polaritons--a
mixture of excitons and photons--behave, in the low density limit, as bosons
that can undergo a phase transition to a regime characterised by long range
coherence. Condensates of polaritons have been advocated as candidates for
superfluidity; and the formation of vortices as well as elementary excitations
with a linear dispersion are actively sought after. In this work, we have
created and set in motion a macroscopically degenerate state of polaritons and
let it collide with a variety of defects present in the sample. Our experiments
show striking manifestations of a coherent light-matter packet that displays
features of a superfluid, although one of a highly unusual character as it
involves an out-of-equilibrium dissipative system where it travels at
ultra-fast velocity of the order of 1% the speed of light. Our main results are
the observation of i) a linear polariton dispersion accompanied with
diffusion-less motion, ii) flow without resistance when crossing an obstacle,
iii) suppression of Rayleigh scattering and iv) splitting into two fluids when
the size of the obstacle is comparable with the size of the wavepacket. This
work opens the way to the investigation of new phenomenology of
out-of-equilibrium condensates.


title: The onion universe: all sky lightcone simulations in spherical shells

abstract:
  Galaxy surveys provide a large-scale view of the universe that typically has
a limited line-of-sight or redshift resolution. The lack of radial accuracy in
these surveys can be modelled by picturing the universe as a set of concentric
radial shells of finite width around the observer, i.e, an onion-like
structure. We present a new N-body simulation with 2048^3 particles developed
at the Marenostrum supercomputer with the GADGET-2 code. Using the lightcone
output we build a set of angular maps that mimic this onion-like representation
of the universe. The onion maps are a highly compressed version of the raw data
(i.e. a factor >1000 smaller size for arcminute resolution maps) and they
provide a new and powerful tool to exploit large scale structure observations.
We introduce two basic applications of these maps that are especially useful
for constraning dark energy properties: the baryon acoustic oscillations (BAO)
in the galaxy power spectrum and all-sky maps of the weak lensing distortion.
Using the weak lensing maps, we measure the convergence power spectra and
compare it to halo fit predictions. As a further application, we compute the
variance and higher-order moments of the maps. We show that sampling variance
on scales of few degrees is quite large, resulting in a significant (25% at 10
arminute scales) bias in the variance. We caution that current lensing surveys
such as the COSMOS HST should take into account this bias and extra sampling
error in their clustering analyses and inferred cosmological parameter
constraints. Finally, we test the importance of projection effects in the weak
lensing mass reconstruction. On the mean, the mass calibration works well but
it exhibits a large non-Gaussian scatter what could induce a large bias in the
recovered mass function.


title: Balanced homodyne detectors and Casimir energy densities

abstract:
  We recall and generalize the analysis of the output of the so-called balanced
homodyne detectors. The most important feature of these detectors is their
ability to quantify the vacuum fluctuations of the electric field, that is
expectation values of products of (quantum-) electric-field operators. More
precisely, the output of BHDs provides information on the one- and two-point
functions of arbitrary states of quantum fields. We generalize the analysis of
the response of BHDs to the case of quantum fields under influence of static
external conditions such as cavities or polarizable media. By recalling the
expressions for two-point functions of quantum fields in Casimir geometries we
show, that a rich, position- and frequency-dependent pattern of BHD responses
is predicted for ground states. This points to a potentially new
characterization of quantum fields in Casimir setups which would not only
complement the current global methods (Casimir forces), but also improve
understanding of sub-vacuum energy densities present in some regions in these
geometries.


title: The History and Morphology of Helium Reionization

abstract:
  A variety of observations now indicate that intergalactic helium was fully
ionized by z~3. The most recent measurements of the high-redshift quasar
luminosity function imply that these sources had produced ~2.5 ionizing photons
per helium atom by that time, consistent with a picture in which the known
quasar population drives HeII reionization. Here we describe the distribution
of ionized and neutral helium gas during this era. Because the sources were
rare and bright (with the photon budget dominated by quasars with luminosities
L>L_\star), random fluctuations in the quasar population determined the
morphology of ionized gas when the global ionized fraction x_i was small, with
the typical radius R_c of a HeIII bubble ~15-20 comoving Mpc. Only when x_i>0.5
did the large-scale clustering of the quasars drive the characteristic size of
ionized regions above this value. Still later, when x_i>0.75, most ionizing
photons were consumed by dense, recombining systems before they reached the
edge of their source's ionized surroundings, halting the bubble growth when
R_c~35-40 Mpc. These phases are qualitatively similar to those in hydrogen
reionization, but the rarity of the sources makes the early stochastic phase
much more important. Moreover, the well-known characteristics of the z=3
intergalactic medium allow a much more robust description of the late phase in
which recombinations dominate.


title:
Linear response results for phonons and electron-phonon coupling in hcp
  Sc - spin fluctuations and implications for superconductivity

abstract:
  We present a study of the electronic structure, phonon frequencies and
electron-phonon coupling in hcp Sc under pressure. The electron-phonon coupling
constant is found to increase steadily with pressure in the hcp phase, until
the pressure reaches a value where the hcp phase becomes unstable. Calculations
for the normal pressure $c/a$ ratio predict a phase change somewhere between
calculated pressures of 22 and 30 GPa. The calculated frequencies for the
equilibrium hcp lattice parameters are in good agreement with the inelastic
neutron scattering results. From the measured value of the electronic specific
heat constant and the calculated values of the Fermi level density of states
and electron-phonon coupling constant, we conclude that the electron-paramagnon
coupling constant in hcp Sc should be comparable to the electron-phonon
coupling constant. This indicates that the spin fluctuation effects are strong
enough to suppress superconductivity completely in hcp Sc. Based on estimates
of the electron-paramagnon coupling constants and the calculated or estimated
electron-phonon coupling constants, we argue that the hcp phase may become
superconducting with a very low transition temperature immediately prior to the
transition to the Sc-II phase and that the Sc-II phase should indeed be
superconducting.


title: Charmed Meson Dalitz Plot Analyses at BaBar

abstract:
  We report recent results of the Dalitz plot analyses of D and D_S decays
performed by the BaBar collaboration, and point out some of the important
applications of these results.


title:
Evidence for Two Populations of Classical Transneptunian Objects: The
  Strong Inclination Dependence of Classical Binaries

abstract:
  We have searched 101 Classical transneptunian objects for companions with the
Hubble Space Telescope. Of these, at least 21 are binary. The heliocentric
inclinations of the objects we observed range from 0.6-34 degrees. We find a
very strong anticorrelation of binaries with inclination. Of the 58 targets
that have inclinations of less than 5.5 degrees, 17 are binary, a binary
fraction of 29 +7/-6%. All 17 are similar-brightness systems. On the contrary,
only 4 of the 42 objects with inclinations greater than 5.5 degrees have
satellites and only 1 of these is a similar-brightness binary. This striking
dichotomy appears to agree with other indications that the low eccentricity,
non-resonant Classical transneptunian objects include two overlapping
populations with significantly different physical properties and dynamical
histories.


title: A bound for the "torsion conductor" of a non-CM elliptic curve

abstract:
  Given a non-CM elliptic curve E over Q, define the ``torsion conductor'' m_E
to be the smallest positive integer so that the Galois representation on the
torsion of E has image Pi^{-1}(Gal(Q(E[m_E])/Q), where Pi denotes the natural
projection GL_2(\hat{Z}) onto GL_2(Z/m_E Z). We show that, uniformly for
semi-stable non-CM elliptic curves E over Q, m_E is less than a constant times
the 5th power of the conductor of E.


title:
Resonant Phonon Scattering in Quantum Hall Systems Driven by dc Electric
  Fields

abstract:
  Using dc excitation to spatially tilt Landau levels, we study resonant
acoustic phonon scattering in two-dimensional electron systems. We observe that
dc electric field strongly modifies phonon resonances, transforming resistance
maxima into minima and back into maxima. Further, phonon resonances are
enhanced dramatically in the non-linear dc response and can be detected even at
low temperatures. Most of our observations can be explained in terms of
dc-induced (de)tuning of the resonant acoustic phonon scattering and its
interplay with intra-Landau level impurity scattering. Finally, we observe a
dc-induced zero-differential resistance state and a resistance maximum which
occurs when the electron drift velocity approaches the speed of sound.


title: Weak pseudoconcavity and the maximum modulus principle

abstract:
  We discuss the maximum modulus principle, and weak unique continuation, for
CR functions on an abstract almost CR manifold M. We investigate these matters
under the assumption of weak pseudoconcavity, and obtain sharp results about
propagation along Sussmann leaves.


title:
Rare-earth Doped Amorphous Silicon Microdisk and Microstadium Resonators
  with Emission at 1550nm

abstract:
  Microdisks and microstadium resonators were fabricated on erbium doped
amorphous hydrogenated silicon (a-Si:H<Er>) layers sandwiched in air and native
SiO2 on Si substrates. Annealing condition is optimized to allow large emission
at 1550 nm for samples with erbium concentrations as high as 1.02x10^20
atoms/cm3. Near field scanning optical microscopy shows evidences of the
simultaneous presence of bow-tie and diamond scars. These modes indicate the
high quality of the resonators and the potentiality for achieving amorphous
silicon microcavity lasers.


title: Detecting z > 2 Type IIn Supernovae

abstract:
  Type IIn supernovae (SNe IIn) dominate the brightest supernova events in
observed FUV flux (~1200-2000A). We show that multi-band, multi-epoch optical
surveys complete to m_r = 27 can detect the FUV emission of ~25 z > 2 SNe IIn
deg^-2 yr^-1 rest-frame (~10 SNe IIn deg^-2 yr^-1 observed-frame) to 4 sigma
using a technique monitoring color-selected galaxies. Moreover, the strength
and evolution of the bright emission lines observed in low redshift SNe IIn
imply that the Ly-a emission features in ~70% of z > 2 SNe IIn are above
8m-class telescope spectroscopic thresholds for ~2 yr rest-frame. As a result,
existing facilities have the capability to both photometrically detect and
spectroscopically confirm z > 2 SNe IIn and pave the way for efficient searches
by future 8m-class survey and 30m-class telescopes. The method presented here
uses the sensitivities and wide-field capabilities of current optical
instruments and exploits (1) the efficiency of z > 2 galaxy color-selection
techniques, (2) the intrinsic brightness distribution (<M_B> = -19.0 +/-0.9)
and blue profile of SNe IIn continua, (3) the presence of extremely bright,
long-lived emission features, and (4) the potential to detect blueshifted SNe
Ly-a emission shortward of host galaxy Ly-a features.


title:
On the recognition of fundamental physical principles in recent
  atmospheric-environmental studies

abstract:
  In this paper, so-called alternative mass balance equations for atmospheric
constituents published recently are assessed in comparison with the true local
mass balance equations deduced from exact integral formulations. It is shown
that these "alternative" expressions appreciably violate the physical law of
the conservation of mass as expressed by the equation of continuity. It is also
shown that terms of these "alternative" mass balance equations have different
physical units, a clear indication that these "alternative" expressions are
incorrect. Furthermore, it is argued that in the case of "alternative" mass
balance equations a real basis for Monin-Obukhov similarity laws does not
exist. These similarity laws are customarily used to determine the turbulent
fluxes of momentum, sensible heat and matter in the so-called atmospheric
surface layer over even terrain. Moreover, based on exact integral formulations
a globally averaged mass balance equation for trace species is derived. It is
applied to discuss the budget of carbon dioxide on the basis of the globally
averaged natural and anthropogenic emissions and the globally averaged uptake
caused by the terrestrial biosphere and the oceans.


title: Homotopy methods for counting reaction network equilibria

abstract:
  Dynamical system models of complex biochemical reaction networks are usually
high-dimensional, nonlinear, and contain many unknown parameters. In some cases
the reaction network structure dictates that positive equilibria must be unique
for all values of the parameters in the model. In other cases multiple
equilibria exist if and only if special relationships between these parameters
are satisfied. We describe methods based on homotopy invariance of degree which
allow us to determine the number of equilibria for complex biochemical reaction
networks and how this number depends on parameters in the model.


title: Mid-Infrared Spectral Diagnosis of Submillimeter Galaxies

abstract:
  We present deep mid-infrared spectroscopy with the Spitzer Space Telescope of
13 submillimeter galaxies (SMGs) in the Great Observatories Origins Deep Survey
North (GOODS-N) field. We find strong polycyclic aromatic hydrocarbon (PAH)
emission in all of our targets which allows us to measure mid-IR spectroscopic
redshifts and place constraints on the contribution from star formation and
active galactic nuclei (AGN) activity to the mid-IR emission. In the high
signal-to-noise ratio composite spectrum of SMGs, we find that the hot dust
continuum from an AGN contributes at most 30% of the mid-IR luminosity. We find
that the mid-IR properties of SMGs are distinct from those of 24 micron
-selected ULIRGs at z~2; the former are predominantly dominated by star
formation while the latter are a more heterogeneous sample with many showing
significant AGN activity. We fit the IRS spectrum and the mid-IR to radio
photometry of SMGs with template spectral energy distributions to determine the
best estimate of the total infrared luminosity from star formation. While many
SMGs contain an AGN as evinced by their X-ray properties, our multi-wavelength
analysis shows that the total infrared luminosity, LIR, in SMGs, is dominated
by star formation and not AGN activity. We find that high redshift SMGs lie on
the relation between LIR and LPAH6.2 (or LPAH7.7 or LPAH11.3) that has been
established for local starburst galaxies. This suggests that PAH luminosity can
be used as a proxy for the star formation rate in SMGs. SMGs are consistent
with being a short lived cool phase in a massive merger. Although there appears
to be an AGN present in many SMGs, it does not appear to have become strong
enough to heat the dust and dominate the mid- or far-infrared emission.


title:
CCO Pulsars as Anti-Magnetars: Evidence of Neutron Stars Weakly
  Magnetized at Birth

abstract:
  Our new study of the two central compact object pulsars, PSR J1210-5226 (P =
424 ms) and PSR J1852+0040 (P = 105 ms), leads us to conclude that a weak natal
magnetic field shaped their unique observational properties. In the dipole
spin-down formalism, the 2-sigma upper limits on their period derivatives, <
2E-16 for both pulsars, implies surface magnetic field strengths of B_s < 3E11
G and spin periods at birth equal to their present periods to three significant
digits. Their X-ray luminosities exceed their respective spin-down
luminosities, implying that their thermal spectra are derived from residual
cooling and perhaps partly from accretion of supernova debris. For sufficiently
weak magnetic fields an accretion disk can penetrate the light cylinder and
interact with the magnetosphere while resulting torques on the neutron star
remain within the observed limits. We propose the following as the origin of
radio-quiet CCOs: the magnetic field, derived from a turbulent dynamo, is
weaker if the NS is formed spinning slowly, which enables it to accrete SN
debris. Accretion excludes neutron stars born with both B_s < 1E11 G and P >
0.1 s from radio pulsar surveys, where such weak fields are not encountered
except among very old (> 40 Myr) or recycled pulsars. We predict that these
birth properties are common, and may be attributes of the youngest detected
neutron star, the CCO in Cassiopeia A, as well as an undetected infant neutron
star in the SN 1987A remnant. In view of the far-infrared light echo discovered
around Cas A and attributed to an SGR-like outburst, it is especially important
to determine via timing whether Cas A hosts a magnetar or not. If not a
magnetar, the Cas A NS may instead have undergone a one-time phase transition
(corequake) that powered the light echo.


title: Decoherence in quantum walks and quantum computers

abstract:
  Decoherence is the major stumbling block in the realization of a large-scale
quantum computer. Ingenious methods have been devised to overcome decoherence,
but their success has been proven only for over-simplified models of
system-environment interaction. Whether such methods will be reliable in the
face of more realistic models is a fundamental open question. In this partly
pedagogical article, we study two toy models of quantum information processing,
using the language of \emph{quantum walks}. Decoherence is incorporated in 3
ways - by coupling to a noisy `projective measurement' system, and by coupling
to oscillator and spin baths.


title: A comparative code study for quantum fault-tolerance

abstract:
  We study a comprehensive list of quantum codes as candidates of codes to be
used at the bottom, physical, level in a fault-tolerant code architecture.
Using the Aliferis-Gottesman-Preskill (AGP) ex-Rec method we calculate the
pseudo-threshold for these codes against depolarizing noise at various levels
of overhead. We estimate the logical noise rate as a function of overhead at a
physical error rate of $p_0=1\times 10^{-4}$. The Bacon-Shor codes and the
Golay code are the best performers in our study.


title:
Gluing constructions for asymptotically hyperbolic manifolds with
  constant scalar curvature

abstract:
  We show that asymptotically hyperbolic initial data satisfying smallness
conditions in dimensions $n\ge 3$, or fast decay conditions in $n\ge 5$, or a
genericity condition in $n\ge 9$, can be deformed, by a deformation which is
supported arbitrarily far in the asymptotic region, to ones which are exactly
Kottler ("Schwarzschild- adS") in the asymptotic region.


title:
Infrared Investigation of the Charge Ordering Pattern in the Organic
  Spin Ladder Candidate (DTTTF)2Cu(mnt)2

abstract:
  We measured the variable temperature infrared response of the spin ladder
candidate (DTTTF)2Cu(mnt)2 in order to distinguish between two competing ladder
models, rectangular versus zigzag, proposed for this family of materials. The
distortion along the stack direction below 235 K is consistent with a doubling
along b through the metal-insulator transition. While this would agree with
either of the ladder models, the concomitant transverse distortion rules out
the rectangular ladder model and supports the zigzag scenario. Intramolecular
distortions within the DTTTF building block molecule also give rise to on-site
charge asymmetry.


title: Emergent universe in a Jordan-Brans-Dicke theory

abstract:
  In this paper we study emergent universe model in the context of a self
interacting Jordan-Brans-Dicke theory. The model presents a stable past eternal
static solution which eventually enters a phase where the stability of this
solution is broken leading to an inflationary period. We also establish
constraints for the different parameters appearing in our model.


title:
Improving the Calibration of Type Ia Supernovae Using Late-time
  Lightcurves

abstract:
  The use of Type Ia supernovae (SNe Ia) as cosmological standard candles is a
key to solving the mystery of dark energy. Improving the calibration of SNe Ia
increases their power as cosmological standard candles. We find tentative
evidence for a correlation between the late-time lightcurve slope and the peak
luminosity of SNe Ia in the B band; brighter SNe Ia seem to have shallower
lightcurve slopes between 100 and 150 days from maximum light. Using a Markov
Chain Monte Carlo analysis in calibrating SNe Ia, we are able to simultaneously
take into consideration the effect of dust extinction, the luminosity and
lightcurve width correlation (parametrized by \Delta m_{15}), and the
luminosity and late-time lightcurve slope correlation. For the available sample
of 11 SNe Ia with well-measured late-time lightcurves, we find that correcting
for the correlation between luminosity and late-time lightcurve slope of the
SNe Ia leads to an intrinsic dispersion of 0.12 mag in the Hubble diagram. Our
results have significant implications for future supernova surveys aimed to
illuminate the nature of dark energy.


title: The Hecke group algebra of a Coxeter group and its representation theory

abstract:
  Let W be a finite Coxeter group. We define its Hecke-group algebra by gluing
together appropriately its group algebra and its 0-Hecke algebra. We describe
in detail this algebra (dimension, several bases, conjectural presentation,
combinatorial construction of simple and indecomposable projective modules,
Cartan map) and give several alternative equivalent definitions (as symmetry
preserving operator algebra, as poset algebra, as commutant algebra, ...).
  In type A, the Hecke-group algebra can be described as the algebra generated
simultaneously by the elementary transpositions and the elementary sorting
operators acting on permutations. It turns out to be closely related to the
monoid algebras of respectively nondecreasing functions and nondecreasing
parking functions, the representation theory of which we describe as well.
  This defines three towers of algebras, and we give explicitly the
Grothendieck algebras and coalgebras given respectively by their induction
products and their restriction coproducts. This yields some new interpretations
of the classical bases of quasi-symmetric and noncommutative symmetric
functions as well as some new bases.


title: Universal Fermi Gas with Two- and Three-Body Resonances

abstract:
  We consider a Fermi gas with two components of different masses, with the
s-wave two-body interaction tuned to unitarity. In the range of mass ratio
8.62<M/m<13.6, it is possible for a single contact interaction between heavy
fermions to produce a resonance in a three-body channel. The resulting system
is scale invariant and has universal properties, and is very strongly
interacting. When M/m is slightly above the lower limit 8.62, the ground state
energy of a 2:1 mixture of heavy and light fermions is less than 2% of the
energy of a noninteracting gas with the same number densities. We derive exact
relationships between the pressures of the unitary Fermi gases with and without
three-body resonance when the mass ratio is close to the critical values of
8.62 and 13.6. Possible experimental realization with cold atoms in optical
lattices is discussed.


title: Bose Hubbard model in the presence of Ohmic dissipation

abstract:
  We study the zero temperature mean-field phase diagram of the Bose-Hubbard
model in the presence of local coupling between the bosons and an external
bath. We consider a coupling that conserves the on-site occupation number,
preserving the robustness of the Mott and superfluid phases. We show that the
coupling to the bath renormalizes the chemical potential and the interaction
between the bosons and reduces the size of the superfluid regions between the
insulating lobes. For strong enough coupling, a finite value of hopping is
required to obtain superfluidity around the degeneracy points where Mott phases
with different occupation numbers coexist. We discuss the role that such a bath
coupling may play in experiments that probe the formation of the
insulator-superfluid shell structure in systems of trapped atoms.