title: New coins from old, smoothly

abstract:
  Given a (known) function $f:[0,1] \to (0,1)$, we consider the problem of
simulating a coin with probability of heads $f(p)$ by tossing a coin with
unknown heads probability $p$, as well as a fair coin, $N$ times each, where
$N$ may be random. The work of Keane and O'Brien (1994) implies that such a
simulation scheme with the probability $\P_p(N<\infty)$ equal to 1 exists iff
$f$ is continuous. Nacu and Peres (2005) proved that $f$ is real analytic in an
open set $S \subset (0,1)$ iff such a simulation scheme exists with the
probability $\P_p(N>n)$ decaying exponentially in $n$ for every $p \in S$. We
prove that for $\alpha>0$ non-integer, $f$ is in the space $C^\alpha [0,1]$ if
and only if a simulation scheme as above exists with $\P_p(N>n) \le C
(\Delta_n(p))^\alpha$, where $\Delta_n(x)\eqbd \max \{\sqrt{x(1-x)/n},1/n \}$.
The key to the proof is a new result in approximation theory:
  Let $\B_n$ be the cone of univariate polynomials with nonnegative Bernstein
coefficients of degree $n$. We show that a function $f:[0,1] \to (0,1)$ is in
$C^\alpha [0,1]$ if and only if $f$ has a series representation
$\sum_{n=1}^\infty F_n$ with $F_n \in \B_n$ and $\sum_{k>n} F_k(x) \le
C(\Delta_n(x))^\alpha$ for all $ x \in [0,1]$ and $n \ge 1$. We also provide a
counterexample to a theorem stated without proof by Lorentz (1963), who claimed
that if some $\phi_n \in \B_n$ satisfy $|f(x)-\phi_n(x)| \le C
(\Delta_n(x))^\alpha$ for all $ x \in [0,1]$ and $n \ge 1$, then $f \in
C^\alpha [0,1]$.


title:
Kaon and antikaon optical potentials in isospin asymmetric hyperonic
  matter

abstract:
  The medium modifications of the energies of kaons and antikaons in isospin
asymmetric hyperonic matter are investigated using a chiral SU(3) model. The
isospin dependent medium effects, are important for asymmetric heavy ion
collision experiments, as well as relevant for the neutron star phenomenology
as the bulk matter in the interior of the neutron star is highly isospin
asymmetric. The effects of hyperons on the medium modifications of the kaons
and antikaons in the strange hadronic matter are investigated in the present
work and are seen to be appreciable for hadronic matter with large strangeness
fractions. The study of the K-mesons in the asymmetric strange hadronic matter
can be especially relevant for the compressed strange baryonic matter which can
result from asymmetric heavy ion collision experiments in the future
accelerator facility FAIR at GSI.


title:
Coherent population trapping in a dressed two-level atom via a
  bichromatic field

abstract:
  We show theoretically that by applying a bichromatic electromagnetic field,
the dressed states of a monochromatically driven two-level atom can be pumped
into a coherent superposition termed as dressed-state coherent population
trapping. Such effect can be viewed as a new doorknob to manipulate a two-level
system via its control over dressed-state populations. Application of this
effect in the precision measurement of Rabi frequency, the unexpected
population inversion and lasing without inversion are discussed to demonstrate
such controllability.


title: Unstable Disk Galaxies. II. the Origin of Growing and Stationary Modes

abstract:
  I decompose the unstable growing modes of stellar disks to their Fourier
components and present the physical mechanism of instabilities in the context
of resonances. When the equilibrium distribution function is a non-uniform
function of the orbital angular momentum, the capture of stars into the
corotation resonance imbalances the disk angular momentum and triggers growing
bar and spiral modes. The stellar disk can then recover its angular momentum
balance through the response of non-resonant stars. I carry out a complete
analysis of orbital structure corresponding to each Fourier component in the
radial angle, and present a mathematical condition for the occurrence of van
Kampen modes, which constitute a continuous family. I discuss on the
discreteness and allowable pattern speeds of unstable modes and argue that the
mode growth is saturated due to the resonance overlapping mechanism. An
individually growing mode can also be suppressed if the corotation and inner
Lindblad resonances coexist and compete to capture a group of stars. Based on
this mechanism, I show that self-consistent scale-free disks with a sufficient
distribution of non-circular orbits should be stable under perturbations of
angular wavenumber $m>1$. I also derive a criterion for the stability of
stellar disks against non-axisymmetric excitations.


title: Quantum computing with alkaline earth atoms

abstract:
  We present a complete scheme for quantum information processing using the
unique features of alkaline earth atoms. We show how two completely independent
lattices can be formed for the $^1$S$_0$ and $^3$P$_0$ states, with one used as
a storage lattice for qubits encoded on the nuclear spin, and the other as a
transport lattice to move qubits and perform gate operations. We discuss how
the $^3$P$_2$ level can be used for addressing of individual qubits, and how
collisional losses from metastable states can be used to perform gates via a
lossy blockade mechanism.


title:
Perfect coupling of light to surface plasmons with ultra-narrow
  linewidths

abstract:
  We examine the coupling of electromagnetic waves incident normal to a thin
silver film that forms an oscillatory grating embedded between two otherwise
uniform, semi-infinite half spaces. Two grating structures are considered, in
one of which the mid point of the Ag film remains fixed whereas the thickness
varies sinusoidally, while in the other the mid point oscillates sinusoidally
whereas the film thicknesses remains fixed. On reducing the light wavelength
from the long wavelength limit, we encounter signatures in the transmission, T,
and reflection, R, coefficients associated with: i) the short-range surface
plasmon mode, ii) the long-range surface plasmon mode, and iii) electromagnetic
diffraction tangent to the grating. The first two features can be regarded as
generalized (plasmon) Wood's anomalies whereas the third is the first-order
conventional (electromagnetic) Wood's anomaly. The energy density at the film
surface is enhanced for wavelengths corresponding to these three anomalies,
particularly for the long range plasmon mode in thin films. When exciting the
silver film with a pair of waves incident from opposite directions, we find
that by adjusting the grating oscillation amplitude and fixing the relative
phase of the incoming waves to be even or odd, T+R can be made to vanish for
one or the other of the plasmon modes; this corresponds to perfect coupling
(impedance matching in the language of electrical engineering) between the
incoming light and these modes.


title:
Logarithmic conformal field theory approach to topologically massive
  gravity

abstract:
  We study the topologically massive gravity at the chiral point (chiral
gravity) by using the logarithmic conformal field theory. Two new tensor fields
of $\psi^{new}$ and $X$ are introduced for a candidate of propagating physical
field at the chiral point. However, we show that ($\psi^{new},\psi^L$) form a
dipole ghost pair of unphysical fields and $X$ is not a primary. This implies
that there is no physically propagating degrees of freedom at the chiral point.


title:
Breakdown of the initial value formulation of scalar-tensor gravity and
  its physical meaning

abstract:
  We revisit singularities of two distinct kinds in the Cauchy problem of
general scalar-tensor theories of gravity (previously discussed in the
literature), and of metric and Palatini f(R) gravity, in both their Jordan and
Einstein frame representations. Examples and toy models are used to shed light
onto the problem and it is shown that, contrary to common lore, the two
conformal frames are equivalent with respect to the initial value problem.


title: Search for new physics in $B_s$-mixing

abstract:
  We present the current status of the search for new physics effects in the
mixing quantities $\Delta M_s$, $\Delta \Gamma_s$ and $\phi_s$ of the neutral
$B_s$-system.


title: Correction to Relativistic Mean Field binding energy and $N_pN_n$ scheme

abstract:
  The differences between the experimental and Relativistic Mean Field binding
energies have been calculated for a large number of even-even nuclei from A=50
to 220. Excluding certain mass regions, the differences, after suitable
corrections for particular isotope chains, are found to be proportional to the
Casten factor $P$, chosen as a measure of n-p interaction strength in a
nucleus. Results for even-$Z$ odd-$N$ nuclei are also seen to follow the same
relation, if the odd-even mass difference is taken into account following the
semiempirical formula. This indicates that the n-p interaction is the major
contributor to the difference between the calculated and the experimental
binding energies.


title:
Next to Leading Order Chiral Perturbation theory of $K \pi \to \pi$ and
  $K\to\pi\pi$ amplitudes

abstract:
  It is shown that the low energy coefficients of the next-to-leading order
(NLO) chiral perturbation theory needed to determine $\Delta I=1/2$,
$K\to\pi\pi$ decay amplitudes can be fixed by calculating $K\pi\to\pi$
amplitudes on lattice. Unlike using NLO $K\to\pi\pi$ amplitudes proposed by
Laiho and Soni, simulating $K\pi\to\pi$ transitions on lattice does not require
evaluations of s-channel disconnected diagrams which have been an obstacle in
practice.


title: On higher order Sugawara operators

abstract:
  The higher Sugawara operators acting on the Verma modules over the affine
Kac-Moody algebra at the critical level are related to the higher Hamiltonians
of the Gaudin model due to work of Feigin, Frenkel and Reshetikhin. An explicit
construction of the higher Hamiltonians in the case of gl_n was given recently
by Talalaev. We propose a new approach to these results from the viewpoint of
the vertex algebra theory by proving directly the formulas for the higher order
Sugawara operators. The eigenvalues of the operators in the Wakimoto modules of
critical level are also calculated.


title:
Synthesis and superconducting properties of the iron oxyarsenide
  TbFeAsO0.85

abstract:
  The iron oxyarsenide TbFeAsO0.85 was synthesized by a high-pressure method. A
high-quality polycrystalline sample was obtained and characterized by
measurements of magnetic susceptibility and electrical resistivity. Bulk
superconductivity with Tc of 42 K was clearly established without an F doping
usually conducted to tune on superconductivity in the iron oxypnictide.


title: The effect of a stellar magnetic variation on the jet velocity

abstract:
  Stellar jets are normally constituted by chains of knots with some
periodicity in their spatial distribution, corresponding to a variability of
order of several years in the ejection from the protostar/disk system. A widely
accepted theory for the presence of knots is related to the generation of
internal working surfaces due to variations in the jet ejection velocity. In
this paper we study the effect of variations in the inner disk-wind radius on
the jet ejection velocity. We show that a small variation in the inner
disk-wind radius produce a variation in the jet velocity large enough to
generate the observed knots. We also show that the variation in the inner
radius may be related to a variation of the stellar magnetic field.


title: Density, short-range order and the quark-gluon plasma

abstract:
  We study the thermal part of the energy density spatial correlator in the
quark-gluon plasma. We describe its qualitative form at high temperatures. We
then calculate it out to distances approx. 1.5/T in SU(3) gauge theory lattice
simulations for the range of temperatures 0.9<= T/T_c<= 2.2. The
vacuum-subtracted correlator exhibits non-monotonic behavior, and is almost
conformal by 2T_c. Its broad maximum at r approx. 0.6/T suggests a dense medium
with only weak short-range order, similar to a non-relativistic fluid near the
liquid-gas phase transition, where eta/s is minimal.


title:
Half-metallic ferromagnetism in binary compounds of alkali metals with
  nitrogen: Ab initio calculations

abstract:
  The first-principles full-potential linearized augmented plane-wave method
based on density functional theory is used to investigate electronic structure
and magnetic properties of hypothetical binary compounds of I$^{A}$ subgroup
elements with nitrogen (LiN, NaN, KN and RbN) in assumed three types of
cristalline structure (rock salt, wurtzite and zinc-blende). We find that, due
to the spin polarized \textit{p} orbitas of N, all four compounds are
half-metallic ferromagnets with wide energy bandgaps (up to 2.0 eV). The
calculated total magnetic moment in all investigated compounds for all three
types of crystal structure is exactly 2.00 $\mu_{\text{B}}$ per formula unit.
The predicted half-metallicity is robust with respect to lattice-constant
contraction. In all the cases ferromagnetic phase is energetically favored with
respect to the paramagnetic one. The mechanism leading to half-metallic
ferromagnetism and synthesis possibilities are discussed.


title: Correlation of spin and velocity in granular gases

abstract:
  In a granular gas of rough particles the spin of a grain is correlated with
its linear velocity. We develop an analytical theory to account for these
correlations and compare its predictions to numerical simulations, using Direct
Simulation Monte Carlo as well as Molecular Dynamics. The system is shown to
relax from an arbitrary initial state to a quasi-stationary state, which is
characterized by time-independent, finite correlations of spin and linear
velocity. The latter are analysed systematically for a wide range of system
parameters, including the coefficients of tangential and normal restitution as
well as the moment of inertia of the particles. For most parameter values the
axis of rotation and the direction of linear momentum are perpendicular like in
a sliced tennis ball, while parallel orientation, like in a rifled bullet,
occurs only for a small range of parameters. The limit of smooth spheres is
singular: any arbitrarily small roughness unavoidably causes significant
translation-rotation correlations, whereas for perfectly smooth spheres the
rotational degrees of freedom are completely decoupled from the dynamic
evolution of the gas.


title: Dust properties and distribution in dwarf galaxies

abstract:
  We present a study of the extinction, traced by the Balmer decrement, in HII
regions in the dwarf galaxies NGC 1569 and NGC 4214. We find that the
large-scale extinction around the most prominent HII regions in both galaxies
forms a shell in which locally the intrinsic extinction can adopt relatively
high values ($A_V = 0.8 - 0.9$ mag) despite the low metallicity and thus the
low overall dust content. The small-scale extinction (spatial resolution
$\sim$0.3'') shows fluctuations that are most likely due to variations in the
dust distribution. We compare the distribution of the extinction to that of the
dust emission, traced by Spitzer emission at 8 and 24 \mi, and to the emission
of cold dust at 850 \mi. We find in general a good agreement between all
tracers, expect for the 850 \mi emission in NGC 4214 which is more extended
than the extinction and the other emissions. Whereas in NGC 1569 the dust
emission at all wavelengths is very similar, NGC 4214 shows spatial variations
in the 24-to-850 \mi ratio. We furthermore compared the 24 \mi and the
extinction-corrected Halpha emission from HII regions in a sample of galaxies
with a wide range of metallicities and found a good correlation between both
emissions, independent of metallicity. We suggest that this lack of dependence
on metallicity might be due to the formation of dust shells with a relatively
constant opacity, like the ones observed here, around ionizing stars.


title: Intermediate Phase IV in Structural Phase Transitions of TlCoCl$_3$

abstract:
  The structural changes of TlCoCl$_3$ around phase IV (68 K $<T<$ 75 K) were
studied by single-crystal neutron diffraction measurement. The present
investigation revealed that a small but definite Bragg peak at (${1/6} {1/6}
2$) appeared only in phase IV. A precursor phenomenon of the phase V ($T<$ 68
K) structure in the phase IV temperatures was also identified as the
coexistence of a slightly broadened (${1/4} {1/4} 2$) Bragg peak. We confirmed
that intermediate phase IV is a stable, nontransient, single phase with
$2\sqrt{3}a\times 2\sqrt{3}a\times c$ unit cells. A possible sequence of
structural phase transitions was proposed.


title: Action integrals and infinitesimal characters

abstract:
  Let $G$ be a reductive Lie group and ${\mathcal O}$ the coadjoint orbit of a
hyperbolic element of ${\frak g}^*$. By $\pi$ is denoted the unitary
irreducible representation of $G$ associated with ${\mathcal O}$ by the orbit
method. We give geometric interpretations in terms of concepts related to
${\mathcal O}$ of the constant $\pi(g)$, for $g\in Z(G)$.
  We also offer a description of the invariant $\pi(g)$ in terms of action
integrals and Berry phases. In the spirit of the orbit method we interpret
geometrically the infinitesimal character of the differential representation of
$\pi$.


title:
Heteroepitaxial growth and optoelectronic properties of layered iron
  oxyarsenide, LaFeAsO

abstract:
  Epitaxial thin films of LaFeAsO were fabricated on MgO (001) and
mixed-perovskite (La, Sr)(Al, Ta)O3 (001) single-crystal substrates by pulsed
laser deposition using a Nd:YAG second harmonic source and a 10 at.% F-doped
LaFeAsO disk target. Temperature dependences of the electrical resistivities
showed no superconducting transition in the temperature range of 2-300 K, and
were similar to those of undoped polycrystalline bulk samples. The
transmittance spectrum exhibited a clear peak at ~0.2 eV, which is explained by
ab-initio calculations.


title:
Relationship between spin squeezing and single-particle coherence in
  two-component Bose-Einstein condensates with Josephson coupling

abstract:
  We investigate spin squeezing of a two-mode boson system with a Josephson
coupling. An exact relation between the squeezing and the single-particle
coherence at the maximal-squeezing time is discovered, which provides a more
direct way to measure the squeezing by readout the coherence in atomic
interference experiments. We prove explicitly that the strongest squeezing is
along the $J_z$ axis, indicating the appearance of atom number-squeezed state.
Power laws of the strongest squeezing and the optimal coupling with particle
number $N$ are obtained based upon a wide range of numerical simulations.


title:
Directed transient long-range transport in a slowly driven Hamiltonian
  system of interacting particles

abstract:
  We study the Hamiltonian dynamics of a one-dimensional chain of linearly
coupled particles in a spatially periodic potential which is subjected to a
time-periodic mono-frequency external field. The average over time and space of
the related force vanishes and hence, the system is effectively without bias
which excludes any ratchet effect. We pay special attention to the escape of
the entire chain when initially all of its units are distributed in a potential
well. Moreover for an escaping chain we explore the possibility of the
successive generation of a directed flow based on large accelerations. We find
that for adiabatic slope-modulations due to the ac-field transient long-range
transport dynamics arises whose direction is governed by the initial phase of
the modulation. Most strikingly, that for the driven many particle Hamiltonian
system directed collective motion is observed provides evidence for the
existence of families of transporting invariant tori confining orbits in
ballistic channels in the high dimensional phase spaces.


title: Macroscopic Model of Geomagnetic-Radiation from Air Showers

abstract:
  We have developed a macroscopic description of coherent electro-magnetic
radiation from air showers initiated by ultra-high energy cosmic rays in the
presence of the geo-magnetic field. This description offers a simple and direct
insight in the relation between the properties of the air shower and the
time-structure of the radio pulse. As we show the structure of the pulse is a
direct reflection of the important length scales in the shower.


title:
Computation of the number of neutrino events which can be registered in
  Borexino detector from the Sun neutrinos flux with energy $E_\nu = 0.862 MeV$

abstract:
  This paper gives an estimation of the number of neutrinos which can be
registered in Borexino detector from the Sun neutrinos generated in reaction
$^{7}Be + e^{-} \to ^{7}Li + \nu_e$ with energy $E_{\nu_e} = 0.862 MeV$ in the
absence of neutrino oscillations. This number is supposed be between $
N^{theor} = 86.45 \div 96.52 \frac{counters}{(day\cdot 100\quad ton)}$ in
dependence on primary neutrino fluxes. Then ratios between number of neutrinos
$N^{exper}$ registered in Borexino detector and counted numbers $N^{theor}$,
are $\frac{N^{exper}}{N^{theor}} = 0.49 \div 0.54$. This value is close enough
to the same value obtained in $^{71}Ga - ^{71}Ge$ experiments in the close
energy regions. The value $\frac{N^{exper}}{N^{theor}}$ obtained at supposition
that $\theta_{1 3} \approx 0$ and absence of the resonance effect approximately
equal to $\simeq 0.67$ and it is noticeably greater than the above value.
Probably it means that the supposition that $\theta_{1 3} \approx 0$ is not
justified and there can be a definite deposit of $\tau$ neutrinos.


title:
The Environmental Dependence of Properties of Galaxies around the
  RDCSJ0910+54 Cluster at z=1.1

abstract:
  (Abridged) We report on the environmental dependence of properties of
galaxies around the RDCSJ0910+54 cluster at z=1.1. We have obtained multi-band
wide-field images of the cluster with Suprime-Cam and MOIRCS on Subaru and
WFCAM on UKIRT. Also, an intensive spectroscopic campaign has been carried out
using LRIS on Keck and FOCAS on Subaru. We discover a possible large-scale
structure around the cluster in the form of three clumps of galaxies. This is
potentially one of the largest structures found so far in the z>1 Universe. We
then examine stellar populations of galaxies in the structure. Red galaxies
have already become the dominant population in the cores of rich clusters at
z~1, and the fraction of red galaxies has not strongly changed since then. The
red fraction depends on richness of clusters in the sense that it is higher in
rich clusters than in poor groups. The luminosity function of red galaxies in
rich clusters is consistent with that in local clusters. On the other hand,
luminosity function of red galaxies in poor groups shows a deficit of faint red
galaxies. This confirms our earlier findings that galaxies follow an
environment-dependent down-sizing evolution. There seems to be a large
variation in the evolutionary phases of galaxies in groups with similar masses.
Further studies of high-z clusters will be a promising way of addressing the
role of nature and nurture effects on galaxy evolution.


title: Phenomenological covariant approach to gravity

abstract:
  We covariantly modify the Einstein-Hilbert action such that the modified
action perturbatively resolves the flat rotational velocity curve of the spiral
galaxies and gives rise to the Tully-Fisher relation, and dynamically generates
the cosmological constant. This modification requires introducing just a single
new universal parameter.


title: Dynamical correlations and collective excitations of Yukawa liquids

abstract:
  In dusty (complex) plasmas, containing mesoscopic charged grains, the
grain-grain interaction in many cases can be well described through a Yukawa
potential. In this Review we summarize the basics of the computational and
theoretical approaches capable of describing many-particle Yukawa systems in
the liquid and solid phases and discuss the properties of the dynamical density
and current correlation spectra of three- and two-dimensional strongly coupled
Yukawa systems, generated by molecular dynamics simulations. We show details of
the $\omega(k)$ dispersion relations for the collective excitations in these
systems, as obtained theoretically following the quasilocalized charge
approximation, as well as from the fluctuation spectra created by simulations.
The theoretical and simulation results are also compared with those obtained in
complex plasma experiments.


title:
Premicellar aggregation of amphiphilic molecules: Aggregate lifetime and
  polydispersity

abstract:
  A recently introduced thermodynamic model of amphiphilic molecules in
solution has yielded, under certain realistic conditions, a significant
presence of metastable aggregates well below the critical micelle concentration
-- a phenomenon that has been reported also experimentally. The theory is
extended in two directions pertaining to the experimental and technological
relevance of such premicellar aggregates. (a) Combining the thermodynamic model
with reaction rate theory, we calculate the lifetime of the metastable
aggregates. (b) Aggregation number fluctuations are examined. We demonstrate
that, over most of the metastable concentration range, the premicellar
aggregates should have macroscopic lifetimes and small polydispersity.


title: Nonstandard Mathematics and New Zeta and L-Functions

abstract:
  This Ph.D. thesis, prepared under the supervision of Professor Ivan Fesenko,
defines new zeta functions in a nonstandard setting and their analytical
properties are developed. Further, p-adic interpolation is presented within a
nonstandard setting which enables the concept of interpolating with respect to
two, or more, distinct primes to be defined.
  The final part of the dissertation examines the work of M. J. Shai Haran and
makes initial attempts of viewing it from a nonstandard perspective.


title: Extremely short-length surface plasmon resonance sensors

abstract:
  The impact of the system design on the control of coupling between planar
waveguide modes and surface plasmon polaritons (SPP) is analyzed. We examine
how the efficiency of the coupling can be enhanced by an appropriate
dimensioning of a multi-layer device structure without using additional
gratings. We demonstrate that by proper design the length of the device can be
dramatically reduced through fabrication a surface plasmon resonance sensor
based on the SPP-photon transformation rather then on SPP dissipation.


title: Electromagnetic energy and momentum in moving media

abstract:
  The problem of the electromagnetic energy-momentum tensor is among the oldest
and the most controversial in macroscopic electrodynamics. In the center of the
issue is a dispute about the Minkowski and the Abraham tensors for moving
media. An overview of the current situation is presented. After putting the
discussion into a general Lagrange-Noether framework, the Minkowski tensor is
recovered as a canonical energy-momentum. It is shown that the balance
equations of energy, momentum, and angular momentum are always satisfied for an
open electromagnetic system despite the lack of the symmetry of the canonical
tensor. On the other hand, although the Abraham tensor is not defined from
first principles, one can formulate a general symmetrization prescription
provided a timelike vector is available. We analyze in detail the variational
model of a relativistic ideal fluid with isotropic electric and magnetic
properties interacting with the electromagnetic field. The relation between the
Minkowski energy-momentum tensor, the canonical energy-momentum of the medium
and the Abraham tensor is clarified. It is demonstrated that the Abraham
energy-momentum is relevant when the 4-velocity of matter is the only covariant
variable that enters the constitutive tensor.


title: LSD and AMAZE: the mass-metallicity relation at z>3

abstract:
  We present the first results on galaxy metallicity evolution at z>3 from two
projects, LSD (Lyman-break galaxies Stellar populations and Dynamics) and AMAZE
(Assessing the Mass Abundance redshift Evolution). These projects use deep
near-infrared spectroscopic observations of a sample of ~40 LBGs to estimate
the gas-phase metallicity from the emission lines. We derive the
mass-metallicity relation at z$>$3 and compare it with the same relation at
lower redshift. Strong evolution from z=0 and z=2 to z=3 is observed, and this
finding puts strong constrains on the models of galaxy evolution. These
preliminary results show that the effective oxygen yields does not increase
with stellar mass, implying that the simple outflow model does not apply at
z>3.


title:
Determination of the single-ion anisotropy energy in a S = 5/2 kagome
  antiferromagnet using X-ray absorption spectroscopy

abstract:
  We report x-ray absorption and x-ray linear dichroism measurements at the Fe
L2,3 edges of the geometrically frustrated systems of potassium and hydronium
iron jarosite. Comparison with simulated spectra, involving ligand-field
multiplet calculations modelling the 3d-2p hybridization between the iron ion
and the oxygen ligands, has yielded accurate estimates for the ligand metal-ion
hybridization and the resulting single-ion crystal field anisotropy energy.
Using this method we provide an experimentally verified scenario for the
appearance of a single-ion anisotropy in this nominally high-spin 3d5 orbital
singlet 6S system, which accounts for features of the spin-wave dispersion in
the long-range ordered ground state of potassium iron jarosite.


title:
A search for associated W and Higgs Boson production in ppbar collisions
  at sqrt{s}=1.96 TeV

abstract:
  We present results of a search for WH -> lepton neutrino b bbar production in
ppbar collisions based on the analysis of 1.05 fb-1 of data collected by the D0
experiment at the Fermilab Tevatron, using a neural network for separating the
signal from backgrounds. No signal-like excess is observed, and we set 95 %
C.L. upper limits on the WH production cross section multiplied by the
branching ratio for H->bb for Higgs boson masses between 100 and 150 GeV. For a
Higgs boson mass of 115 GeV, we obtain an observed (expected) limit of 1.5
(1.4) pb, a factor of 11.4 (10.7) times larger than standard model prediction.


title: Intertwiner dynamics in the flipped vertex

abstract:
  We continue the semiclassical analysis, started in a previous paper, of the
intertwiner sector of the flipped vertex spinfoam model. We use independently
both a semi-analytical and a purely numerical approach, finding the correct
behavior of wave packet propagation and physical expectation values. In the
end, we show preliminary results about correlation functions.


title: De Morgan's law and the theory of fields

abstract:
  We show that the classifying topos for the theory of fields does not satisfy
De Morgan's law, and we identify its largest dense De Morgan subtopos as the
classifying topos for the theory of fields of nonzero characteristic which are
algebraic over their prime fields.


title: MHV Lagrangians for Yang--Mills and QCD

abstract:
  Over the past few decades, it has been realised that gauge theory scattering
amplitudes have structures much simpler than the traditional Feynman graph
driven approach would suggest. In particular, Parke and Taylor found a
particularly simple expression for the tree-level amplitudes with two gluons of
different helicity than the others (the so-called MHV amplitudes). Cachazo,
Svrcek and Witten (CSW) devised rules for constructing tree-level amplitudes by
sewing lower-valence MHV amplitudes together with scalar propagators. It was
shown by Mansfield in 2005 that a canonical change of the field variables could
be constructed that resulted in a lagrangian whose vertices were proportional
to MHV amplitudes, continued off-shell by CSW's prescription, the so-called
Canonical MHV Lagrangian. We derive the explicit form of this transformation
and use this to show that the vertices are indeed the Parke--Taylor amplitudes
for up to five gluons. Noting that CSW's MHV rules cannot be used to construct
the tree-level (-++) or one-loop (++++) amplitudes, we extend our work to
augment the MHV rules with so-called completion vertices. These permit
construction of these missing amplitudes by means of evasion of the S-matrix
equivalence theorem. Indeed, together they reconstruct off-shell light-cone
Yang-Mills amplitudes algebraically. We also give a prescription for
dimensional regularisation of the Canonical MHV Lagrangian. Finally, we
construct a canonical MHV lagrangian with massless fermions in the fundamental
representation using a similar methodology.


title: Calculating intersection numbers on moduli spaces of pointed curves

abstract:
  This is a note on calculating intersection numbers on moduli spaces of
curves. A codimension 3 relation among tautological classes on the moduli space
of genus 4 curves is given.


title: N-Complexes and Higher Spin Gauge Fields

abstract:
  $N$-complexes have been argued recently to be algebraic structures relevant
to the description of higher spin gauge fields. $N$-complexes involve a linear
operator $d$ that fulfills $d^N = 0$ and that defines a generalized cohomology.
Some elementary properties of $N$-complexes and the evidence for their
relevance to the description of higher spin gauge fields are briefly reviewed.


title: Deformed quantum mechanics and q-Hermitian operators

abstract:
  Starting on the basis of the non-commutative q-differential calculus, we
introduce a generalized q-deformed Schr\"odinger equation. It can be viewed as
the quantum stochastic counterpart of a generalized classical kinetic equation,
which reproduces at the equilibrium the well-known q-deformed exponential
stationary distribution. In this framework, q-deformed adjoint of an operator
and q-hermitian operator properties occur in a natural way in order to satisfy
the basic quantum mechanics assumptions.

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


title: Visualization of Superfluid Helium Flow

abstract:
  We discuss an experimental technique to visualize the motion in the bulk of
superfluid $^4$He by tracking micron-sized solid hydrogen tracers. The behavior
of the tracers is complex since they may be trapped by the quantized vortices
while also interacting with the normal fluid via Stokes drag. We discuss the
mechanism by which tracers may be trapped by quantized vortices as well as the
dependencies on hydrogen volume fraction, temperature, and flow properties. We
apply this technique to study the dynamics of a thermal counterflow. Our
observations serve as a direct confirmation of the two-fluid model as well as a
quantitative test of the normal fluid velocity dependence on the applied heat
flux.


title: Conformally Invariant Operators via Curved Casimirs: Examples

abstract:
  We discuss a general scheme for a construction of linear conformally
invariant differential operators from curved Casimir operators; we then
explicitly carry this out for several examples. Apart from demonstrating the
efficacy of the approach via curved Casimirs, this shows that this method
applies both in regular and in singular infinitesimal character, and also that
it can be used to construct standard as well as non--standard operators. The
examples treated include conformally invariant operators with leading term, in
one case, a square of the Laplacian, and in another case, a cube of the
Laplacian.


title: $\pi$-junction qubit in monolayer graphene

abstract:
  We propose to combine the advantages of graphene, such as easy tunability and
long coherence times, with Josephson physics to manufacture qubits. If these
qubits are built around a 0 and $\pi$ junction they can be controlled by an
external flux. Alternatively, a d-wave Josephson junction can itself be tuned
via a gate voltage to create superpositions between macroscopically degenerate
states. We show that ferromagnets are not required for realizing $\pi$ junction
in graphene, thus considerably simplifying its physical implementation. We
demonstrate how one qubit gates, such as arbitrary phase rotations and the
exchange gate, can be implemented.


title:
An Iterative Method for Constructing Equilibrium Phase Models of Stellar
  Systems

abstract:
  We present a new method for constructing equilibrium phase models for stellar
systems, which we call the iterative method. It relies on constrained, or
guided evolution, so that the equilibrium solution has a number of desired
parameters and/or constraints. This method is very powerful, to a large extent
due to its simplicity. It can be used for mass distributions with an arbitrary
geometry and a large variety of kinematical constraints. We present several
examples illustrating it. Applications of this method include the creation of
initial conditions for N-body simulations and the modelling of galaxies from
their photometric and kinematic observations.


title: Planar Heterostructure Graphene -- Narrow-Gap Semiconductor -- Graphene

abstract:
  We investigate a planar heterostructure composed of two graphene films
separated by a narrow-gap semiconductor ribbon. We show that there is no the
Klein paradox when the Dirac points of the Brillouin zone of graphene are in a
band gap of a narrow-gap semiconductor. There is the energy range depending on
an angle of incidence, in which the above-barrier damped solution exists.
Therefore, this heterostructure is a "filter" transmitting particles in a
certain range of angles of incidence upon a potential barrier. We discuss the
possibility of an application of this heterostructure as a "switch".


title: Statistical QCD with non-positive measure

abstract:
  In this talk we discuss the microscopic limit of QCD at nonzero chemical
potential. In this domain, where the QCD partition function is under complete
analytical control, we uncover an entirely new link between the spectral
density of the Dirac operator and the chiral condensate: violent complex
oscillations on the microscopic scale give rise to the discontinuity of the
chiral condensate at zero quark mass. We first establish this relation exactly
within a random matrix framework and then analyze the importance of the
individual modes by Fourier analysis.


title:
Ratchet effects induced by terahertz radiation in heterostructures with
  a lateral periodic potential

abstract:
  We report on the observation of terahertz radiation induced photogalvanic
currents in semiconductor heterostructures with one-dimensional lateral
periodic potential. The potential is produced by etching a grating into the
sample surface. The electric current response is well described by
phenomenological theory including both the circular and linear photogalvanic
effects. Experimental data demonstrate that the inversion asymmetry of the
periodic lateral pattern can be varied by means of electron beam lithography to
produce classical lateral ratchets. A novel microscopical mechanism for the
polarization-dependent photogalvanic effects has been proposed to interpret the
experimental findings. The photocurrent generation is based on the combined
action of the lateral periodic potential and the modulated in-plane pumping.
The latter modulation stems from near-field effects of the radiation
propagating through the grating.


title: Detection of 6.7 GHz methanol absorption towards hot corinos

abstract:
  Methanol masers at 6.7 GHz have been found exclusively towards high-mass star
forming regions. Recently, some Class 0 protostars have been found to display
conditions similar to what are found in hot cores that are associated with
massive star formation. These hot corino sources have densities, gas
temperatures, and methanol abundances that are adequate for exciting strong 6.7
GHz maser emission. This raises the question of whether 6.7 GHz methanol masers
can be found in both hot corinos and massive star forming regions, and if not,
whether thermal methanol emission can be detected. We searched for the 6.7 GHz
methanol line towards five hot corino sources in the Perseus region using the
Arecibo radio telescope. To constrain the excitation conditions of methanol, we
observed thermal submillimeter lines of methanol in the NGC1333-IRAS 4 region
with the APEX telescope. We did not detect 6.7 GHz emission in any of the
sources, but found absorption against the cosmic microwave background in
NGC1333-IRAS 4A and NGC1333-IRAS 4B. Using a large velocity gradient analysis,
we modeled the excitation of methanol over a wide range of physical parameters,
and verify that the 6.7 GHz line is indeed strongly anti-inverted for densities
lower than 10^6 cm^-3. We used the submillimeter observations of methanol to
verify the predictions of our model for IRAS 4A by comparison with other CH3OH
transitions. Our results indicate that the methanol observations from the APEX
and Arecibo telescopes are consistent with dense (n ~ 10^6 cm^-3), cold (T ~
15-30 K) gas. The lack of maser emission in hot corinos and low-mass
protostellar objects in general may be due to densities that are much higher
than the quenching density in the region where the radiation field is conducive
to maser pumping.


title:
Superconductivity in Epitaxial Thin Films of Co-Doped SrFe2As2 with
  Bilayered FeAs Structures and their Magnetic Anisotropy

abstract:
  Superconducting epitaxial films of Fe-based layered arsenide, Co-doped
SrFe2As2, were grown at 700oC on mixed perovskite (La, Sr)(Al, Ta)O3 (001)
single-crystal substrates by pulsed-laser deposition. Both the epitaxial film
and an (001)-oriented film grown at 600oC exhibited superconducting transitions
at ~ 20 K. The zero-resistance states of the epitaxial film were sustained
under a magnetic field (H) of 9 T at 9 K when H was parallel to the c-axis,
while they were sustained at higher temperatures up to 10 K for H parallel to
the a-axis. This is the first demonstration of superconducting thin films of
FeAs-based new superconductors.


title: Finite Volume Scaling of Pseudo Nambu-Goldstone Bosons in QCD

abstract:
  We consider chiral perturbation theory in a finite volume and in a mixed
regime of quark masses. We take N_l light quarks near the chiral limit, in the
so-called epsilon-regime, while the remaining N_h quarks are heavier and in the
standard p-regime. We compute in this new mixed regime the finite-size scaling
of the light meson correlators in the scalar, pseudoscalar, vector and axial
vector channels.Using the replica method, we easily extend our results to the
partially quenched theory. With the help of our results, lattice QCD
simulations with 2+1 flavors can safely investigate pion physics with very
light up and down quark masses even in the region where the pion's correlation
length overcomes the size of the space-time lattice.


title:
Photogalvanic effects due to quantum interference in optical transitions
  demonstrated by terahertz radiation absorption in Si-MOSFETs

abstract:
  We report on the observation of the circular (helicity-dependent) and linear
photogalvanic effects in Si-MOSFETs with inversion channels. The developed
microscopic theory demonstrates that the circular photogalvanic effect in Si
structures it is of pure orbital nature originating from the quantum
interference of different pathways contributing to the light absorption.


title:
A tunable narrowband entangled photon pair source for resonant
  single-photon single-atom interaction

abstract:
  We present a tunable, frequency-stabilized, narrow-bandwidth source of
frequency-degenerate, entangled photon pairs. The source is based on
spontaneous parametric downconversion (SPDC) in periodically-poled KTiOPO4
(PPKTP). Its wavelength can be stabilized to 850 or 854 nm, thus allowing to
address two D-P transitions in 40Ca+ ions. Its output bandwidth of 22 MHz
coincides with the absorption bandwidth of the calcium ions. Its spectral power
density is 1.0 generated pairs/(s MHz mW).


title: Charged pions multiplicities at the NA49 energy

abstract:
  The wounded quark-diquark model predictions for charged pions multiplicities
in PbPb and pPb collisions in the central rapidity region at sqrt(s)=17.3 GeV
c.m. energy are presented.


title: Measurement of spatial qubits

abstract:
  In this paper we study the state determination for composite systems of two
spatial qubits. We show, theoretically, that one can use the technique of
quantum tomography to reconstruct the density matrixes of these systems. This
tomographic reconstruction is based on the free evolution of the spatial qubits
and a postelection process.


title: d-collapsibility is NP-complete for d greater or equal to 4

abstract:
  A simplicial complex is d-collapsible if it can be reduced to an empty
complex by repeatedly removing (collapsing) a face of dimension at most d-1
that is contained in a unique maximal face. We prove that the algorithmic
question whether a given simplicial complex is d-collapsible is NP-complete for
d greater or equal to 4 and polynomial time solvable for d at most 2. As an
intermediate step, we prove that d-collapsibility can be recognized by the
greedy algorithm for d at most 2, but the greedy algorithm does not work for d
greater or equal 3. A simplicial complex is d-representable if it is the nerve
of a collection of convex sets in R^d. The main motivation for studying
d-collapsible complexes is that every d-representable complex is d-collapsible.
We also observe that known results imply that analogical algorithmic question
for d-representable complexes is NP-hard for d greater or equal to 2.


title:
On visualisation scaling, subeigenvectors and Kleene stars in max
  algebra

abstract:
  The purpose of this paper is to investigate the interplay arising between max
algebra, convexity and scaling problems. The latter, which have been studied in
nonnegative matrix theory, are strongly related to max algebra. One problem is
strict visualisation scaling, which means finding, for a given nonnegative
matrix A, a diagonal matrix X such that all elements of X^{-1}AX are less than
or equal to the maximum cycle geometric mean of A, with strict inequality for
the entries which do not lie on critical cycles. In this paper such scalings
are described by means of the max-algebraic subeigenvectors and Kleene stars of
nonnegative matrices as well as by some concepts of convex geometry.


title: Symmetry breaking in low-dimensional SU(N) antiferromagnets

abstract:
  Consequences of explicit symmetry breaking in a physically motivated model of
SU(N) antiferromagnet in spatial dimensions one and two are studied. It is
shown that the case N=3, which can be realized in spin-1 cold atom systems,
displays special properties distinctly different from those for N>=4.
Qualitative form of the phase diagram depending on the model parameters is
given.


title: Short seed extractors against quantum storage

abstract:
  Some, but not all, extractors resist adversaries with limited quantum
storage. In this paper we show that Trevisan's extractor has this property,
thereby showing an extractor against quantum storage with logarithmic seed
length.


title:
Local complementation rule for continuous-variable four-mode unweighted
  graph states

abstract:
  The local complementation rule is applied for continuous-variable (CV) graph
states in the paper, which is an elementary graph transformation rule and
successive application of which generates the orbit of any graph states. The
corresponding local Gaussian transformations of local complementation for
four-mode unweighted graph states were found, which do not mirror the form of
the local Clifford unitary of qubit exactly. This work is an important step to
characterize the local Gaussian equivalence classes of CV graph states.


title: Torelli theorem for the moduli space of framed bundles

abstract:
  Let X be an irreducible smooth complex projective curve of genus g>2, and let
x be a fixed point. A framed bundle is a pair (E,\phi), where E is a vector
bundle over X, of rank r and degree d, and \phi:E_x\to C^r is a non-zero
homomorphism. There is a notion of (semi)stability for framed bundles depending
on a parameter \tau>0, which gives rise to the moduli space of \tau-semistable
framed bundles M^\tau. We prove a Torelli theorem for M^\tau, for \tau>0 small
enough, meaning, the isomorphism class of the one-pointed curve (X,x), and also
the integer r, are uniquely determined by the isomorphism class of the variety
M^\tau.


title: Stability of AdS black strings

abstract:
  We review the recent developements in the stability problem and phase diagram
for asymptotically locally $AdS$ black strings. First, we quickly review the
case of locally flat black string before turning to the case of locally $AdS$
spacetimes.


title: Classes of exact Einstein-Maxwell solutions

abstract:
  We find new classes of exact solutions to the Einstein-Maxwell system of
equations for a charged sphere with a particular choice of the electric field
intensity and one of the gravitational potentials. The condition of pressure
isotropy is reduced to a linear, second order differential equation which can
be solved in general. Consequently we can find exact solutions to the
Einstein-Maxwell field equations corresponding to a static spherically
symmetric gravitational potential in terms of hypergeometric functions. It is
possible to find exact solutions which can be written explicitly in terms of
elementary functions, namely polynomials and product of polynomials and
algebraic functions. Uncharged solutions are regainable with our choice of
electric field intensity; in particular we generate the Einstein universe for
particular parameter values.


title: Decoherence measure by gravitational wave interferometers

abstract:
  We consider the possibility to measure the quantum decoherence using
gravitational wave interferometers. Gravitational wave interferometers create
the superposition state of photons and measure the interference of the photon
state. If the decoherence occurs, the interference of the photon state vanishes
and it can be measured by the interferometers. As examples of decoherence
mechanisms, we consider 1) decoherence by spontaneous localization, 2)
gravitational decoherence and 3) decoherence by extra-dimensional gravity.


title:
Reconsidering the asymptotic null distribution of likelihood ratio tests
  for genetic linkage in multivariate variance components models

abstract:
  Accurate knowledge of the null distribution of hypothesis tests is important
for valid application of the tests. In previous papers and software, the
asymptotic null distribution of likelihood ratio tests for detecting genetic
linkage in multivariate variance components models has been stated to be a
mixture of chi-square distributions with binomial mixing probabilities. Here we
show, by simulation and by theoretical arguments based on the geometry of the
parameter space, that all aspects of the previously stated asymptotic null
distribution are incorrect--both the binomial mixing probabilities and the
chi-square components. Correcting the null distribution gives more conservative
critical values than previously stated, yielding P values that can easily be
ten times larger. The true mixing probabilities give the highest probability to
the case where all variance parameters are estimated positive, and the mixing
components show severe departures from chi-square distributions. Thus, the
asymptotic null distribution has complex features that raise challenges for the
assessment of significance of multivariate linkage findings. We propose a
method to generate an asymptotic null distribution that is much faster than
other empirical methods such as gene-dropping, enabling us to obtain P values
with higher precision more efficiently.


title:
High-output CPP-GMR sensor with synthetic-ferrimagnet free layer and
  enhanced spin-torque critical currents

abstract:
  It is shown that the maximum stable output of a CPP-GMR sensor is increased
significantly by using a synthetic ferrimagnet free layer, provided the
electron current flows from free layer to reference layer. This free layer
allows a larger magnetoresistance ratio for a given free layer magnetic moment,
and in addition results in a greater than three-fold increase in the critical
current above which spin-torque instability of the free layer occurs. In read
heads with net free layer moments equivalent to only 4.5nm of Ni80Fe20, this
effect is shown to result in sustainable sense current densities above 2e8
A/cm2.


title:
An application of Jacquet-Langlands correspondence to transfer operators
  for geodesic flows on Riemann surfaces

abstract:
  In the paper as a new application of the Jacquet-Langlands correspondence we
connect the transfer operators for different cofinite Fuchsian groups by
comparing the corresponding Selberg zeta functions.


title:
Lossless Quantum Prefix Compression for Communication Channels that are
  Always Open

abstract:
  We describe a method for lossless quantum compression if the output of the
information source is not known. We compute the best possible compression rate,
minimizing the expected base length of the output quantum bit string (the base
length of a quantum string is the maximal length in the superposition). This
complements work by Schumacher and Westmoreland who calculated the
corresponding rate for minimizing the output's average length.
  Our compressed code words are prefix-free indeterminate-length quantum bit
strings which can be concatenated in the case of multiple sources. Therefore,
we generalize the known theory of prefix-free quantum codes to the case of
strings with indeterminate length. Moreover, we describe a communication model
which allows the lossless transmission of the compressed code words. The
benefit of compression is then the reduction of transmission errors in the
presence of noise.


title: The B\"{a}cklund transforms of Peterson's deformations of quadrics

abstract:
  In trying to provide explicit deformations of quadrics the starting point of
our investigation is to use Bianchi's link between real deformations of totally
real regions of real paraboloids and various totally real forms of the
sine-Gordon equation coupled with Bianchi's simple observation that the vacuum
soliton of these totally real forms of the sine-Gordon equation provides
precisely Peterson's deformations of such quadrics in order to derive explicit
B\"{a}cklund transforms of Peterson's deformations of quadrics. Based also on
Bianchi's approach of the B\"{a}cklund transformation for quadrics via common
conjugate systems and in analogy to the solitons of the sine-Gordon equation
corresponding at the level of the geometric picture to the solitons of the
pseudo-sphere we propose a model for the solitons of quadrics.


title:
On secant loci and simple linear projections of some projective
  varieties

abstract:
  In this paper, we study how simple linear projections of some projective
varieties behave when the projection center runs through the ambient space.
More precisely, let $X \subset \P^r$ be a projective variety satisfying
Green-Lazarsfeld's property $N_p$ for some $p \geq 2$, $q \in \P^r$ a closed
point outside of $X$, and $X_q := \pi_q (X) \subset \P^{r-1}$ the projected
image of $X$ from $q$. First, it is shown that the secant locus $\Sigma_q (X)$
of $X$ with respect to $q$, i.e. the set of all points on $X$ spanning secant
lines passing through $q$, is either empty or a quadric in a subspace of
$\P^r$. This implies that the finite morphism $\pi_q : X \to X_q$ is
birational. Our main result is that cohomological and local properties of $X_q$
are precisely determined by $\Sigma_q (X)$. To complete this result, the next
step should be to classify all possible secant loci and to decompose the
ambient space via the classification of secant loci. We obtain such a
decomposition for Veronese embeddings and Segre embeddings. Also as an
application of the main result, we study cohomological properties of low degree
varieties.


title:
The increase with energy of the parton transverse momenta in the current
  fragmentation region and related pQCD phenomena in DIS at very high energies

abstract:
  We find, within the pQCD dipole model for DIS processes, a rapid increase
with energy of the scale of parton momenta in the current fragmentation region
in the limit $s\to \infty$ and fixed $Q^2$ . We explain the equivalence between
the dispersion representation over $Q^2$ for LT pQCD zero angle amplitude of
$\gamma^*+T\to \gamma^*+T$ scattering at large energies and the $k_t$
factorization, and use it to evaluate the scales of the hard processes in the
current fragmentation region. We derive within the black disc (BD) regime the
modified Gribov formula for the total cross-section of the DIS. We evaluate the
coherence length of the processes relevant for the BD regime and find that it
increases with energy as $\sim s^{0.6}$ i.e. significantly slower than in the
parton model ($1/2m_Nx$ - the Ioffe length) as well as in pQCD. In the BD
regime we estimate the gluon densities, local in the coordinate space, and find
that they do not decrease with the energy. We discuss briefly how the new pQCD
phenomena may reveal itself in the proton-proton collisions at LHC


title: Bianchi's B\"{a}cklund transformation for higher dimensional quadrics

abstract:
  We provide a generalization of Bianchi's B\"{a}cklund transformation from
2-dimensional quadrics to higher dimensional quadrics. The starting point of
our investigation is the higher dimensional (infinitesimal) version of
Bianchi's main four theorems on the theory of deformations of quadrics and
Bianchi's treatment of the B\"{a}cklund transformation for diagonal paraboloids
via conjugate systems.


title: Stably diffeomorphic manifolds and l_{2q+1}(Z[\pi])

abstract:
  The monoids l_{2q+1}(Z[\pi]) detect s-cobordisms amongst certain bordisms
between stably diffeomorphic 2q-dimensional manifolds and generalise the Wall
simple surgery obstruction groups, L_{2q+1}^s(Z[\pi]) \subset l_{2q+1}(Z[\pi]).
In this paper we give exact sequences which completely describe
l_{2q+1}(Z[\pi]) as a set and which we use to compute its Grothendieck group.
As a consequence we deduce cancellation results for stably diffeomorphic
manifolds with polycyclic-by-finite fundamental group.


title:
Thermo-Poro-Mechanical Properties of Clayey Gouge and Application to
  Rapid Fault Shearing

abstract:
  In this paper, the mechanism of fault pressurization in rapid slip events is
analyzed on the basis of a complete characterization of the
thermo-poro-mechanical behavior of a clayey gouge extracted at 760m depth in
Aigion fault in the active seismic zone of the Gulf of Corinth, Greece. It is
shown that the thermally collapsible character of this clayey gouge can be
responsible for a dramatic reduction of effective stress and a full
fluidization of the material. The thickness of the 'ultra localized' zone of
highly strained material is a key parameter that controls the competing
phenomena of pore pressure increase leading to fluidization of the fault gouge
and temperature increase leading to pore fluid vaporization.


title: Dynamical Quantum Memories

abstract:
  We propose a dynamical approach to quantum memories using an
oscillator-cavity model. This overcomes the known difficulties of achieving
high quantum input-output fidelity with storage times long compared to the
input signal duration. We use a generic model of the memory response, which is
applicable to any linear storage medium ranging from a superconducting device
to an atomic medium. The temporal switching or gating of the device may either
be through a control field changing the coupling, or through a variable
detuning approach, as in more recent quantum memory experiments. An exact
calculation of the temporal memory response to an external input is carried
out. This shows that there is a mode-matching criterion which determines the
optimum input and output mode shape. This optimum pulse shape can be modified
by changing the gate characteristics. In addition, there is a critical coupling
between the atoms and the cavity that allows high fidelity in the presence of
long storage times. The quantum fidelity is calculated both for the coherent
state protocol, and for a completely arbitrary input state with a bounded total
photon number. We show how a dynamical quantum memory can surpass the relevant
classical memory bound, while retaining a relatively long storage time.


title:
Finite element analysis of the indentation test on rocks with
  microstructure

abstract:
  Strength parameters of rocks are currently determined from indentation tests.
In this paper, a finite element analysis of this test is presented and scale
effect is studied. The rock is modelled as an elasto-plastic medium with
Cosserat microstructure and consequently possesses an internal length. The
response of the indentation curve is studied for various values of the size of
the indentor as compared to the internal length of the rock in order to assess
the scale effect.


title:
Stress orientation evaluated from strain localisation analysis in Aigion
  fault

abstract:
  Within the frame of the 'CRL' (Corinth Rift Laboratory project) (Cornet et
al, 2004a) centered on the south western sector of the Gulf of Corinth
(http://www.corinth-rift-lab.org), fault zone cores from the active Aigion
fault have been collected continuously from depths between 708 m to 782 m.
Inside this clayey core, a clear shearing surface with marked slip lines is
visible on a plane that makes a 68 degree angle with respect to the core axis.
This failure surface was not induced by the decompression process but is indeed
a slip plane as clear striation is observed at the interface. On the basis of
an elastoplastic constitutive model calibrated on triaxial tests on the clayey
gouge, it is shown that shear band formation inside the clayey core is
possible. The solution for the orientation of the shear band is compared to the
orientation of an existing slip surface inside the clayey gouge and this result
is used to deduce the orientation of the principal stresses. It is shown that
as commonly observed in weak fault zones, the orientation of the principal
stresses is locally almost parallel and perpendicular to the fault axis.


title: Perfect, strongly eutactic lattices are periodic extreme

abstract:
  We introduce a parameter space for periodic point sets, given as unions of
$m$ translates of point lattices. In it we investigate the behavior of the
sphere packing density function and derive sufficient conditions for local
optimality. Using these criteria we prove that perfect, strongly eutactic
lattices cannot be locally improved to yield a periodic sphere packing with
greater density. This applies in particular to the densest known lattice sphere
packings in dimension $d\leq 8$ and $d=24$.


title: Manifestations of CP Violation in the MSSM Higgs Sector

abstract:
  We demonstrate how CP violation manifests itself in the Higgs sector of the
minimal supersymmetric extension of the Standard Model (MSSM). Starting with a
brief introduction to CP violation in the MSSM and its effects on the Higgs
sector, we discuss some phenomenological aspects of the Higgs sector CP
violation based on the two scenarios called CPX and Trimixing


title:
Co-resonant enhancement of spin-torque critical currents in spin-valves
  with synthetic-ferrimagnet free-layer

abstract:
  It is experimentally shown that the critical current for onset of spin-torque
instability in current-perpendicular-to-plane spin-valves can be strongly
enhanced using "synthetic ferrimagnet" free-layers of form FM1/Ru/FM2
(FM=ferrromagnet). However, this enhancement occurs for only one polarity of
bias current. A two-macrospin model is shown to reproduce the observations. The
model suggests that this phenomenon is related to a polarity-dependent,
spin-torque induced co-resonance between the two natural dynamic modes of the
FM1/FM2 couple. The resonance condition facilitates energy transfer out of the
spin-torque destabilized mode into the other stable mode whose effective
damping is actually enhanced by spin-torques, thereby delaying the onset of
instability of this coupled system to larger critical currents.


title: Three-flavour neutrino oscillation update

abstract:
  We review the present status of three-flavour neutrino oscillations, taking
into account the latest available neutrino oscillation data presented at the
Neutrino 2008 Conference. This includes the data released this summer by the
MINOS collaboration, the data of the neutral current counter phase of the SNO
solar neutrino experiment, as well as the latest KamLAND and Borexino data. We
give the updated determinations of the leading 'solar' and 'atmospheric'
oscillation parameters. We find from global data that the mixing angle
$\theta_{13}$ is consistent with zero within $0.9\sigma$ and we derive an upper
bound of $\sin^2\theta_{13} < 0.035 (0.056)$ at 90% CL (3$\sigma$).


title: Nearly Tight Low Stretch Spanning Trees

abstract:
  We prove that any graph $G$ with $n$ points has a distribution $\mathcal{T}$
over spanning trees such that for any edge $(u,v)$ the expected stretch $E_{T
\sim \mathcal{T}}[d_T(u,v)/d_G(u,v)]$ is bounded by $\tilde{O}(\log n)$. Our
result is obtained via a new approach of building ``highways'' between portals
and a new strong diameter probabilistic decomposition theorem.


title: Shear viscosity in neutron star cores

abstract:
  We calculate the shear viscosity $\eta = \eta_{e\mu}+\eta_{n}$ in a neutron
star core composed of nucleons, electrons and muons ($\eta_{e\mu}$ being the
electron-muon viscosity, mediated by collisions of electrons and muons with
charged particles, and $\eta_{n}$ the neutron viscosity, mediated by
neutron-neutron and neutron-proton collisions). Deriving $\eta_{e\mu}$, we take
into account the Landau damping in collisions of electrons and muons with
charged particles via the exchange of transverse plasmons. It lowers
$\eta_{e\mu}$ and leads to the non-standard temperature behavior
$\eta_{e\mu}\propto T^{-5/3}$. The viscosity $\eta_{n}$ is calculated taking
into account that in-medium effects modify nucleon effective masses in dense
matter. Both viscosities, $\eta_{e\mu}$ and $\eta_{n}$, can be important, and
both are calculated including the effects of proton superfluidity. They are
presented in the form valid for any equation of state of nucleon dense matter.
We analyze the density and temperature dependence of $\eta$ for different
equations of state in neutron star cores, and compare $\eta$ with the bulk
viscosity in the core and with the shear viscosity in the crust.


title:
Relaxation of Terrace-width Distributions: Physical Information from
  Fokker-Planck Time

abstract:
  Recently some of us have constructed a Fokker-Planck formalism to describe
the equilibration of the terrace-width distribution of a vicinal surface from
an arbitrary initial configuration. However, the meaning of the associated
relaxation time, related to the strength of the random noise in the underlying
Langevin equation, was rather unclear. Here we present a set of careful kinetic
Monte Carlo simulations that demonstrate convincingly that the time constant
shows activated behavior with a barrier that has a physically plausible
dependence on the energies of the governing microscopic model. Furthermore, the
Fokker-Planck time at least semiquantitatively tracks the actual physical time.


title: Exclusive J/psi photoproduction in pp and ppbar collisions

abstract:
  We report on a detailed investigation of exclusive J/psi production in
proton--proton and proton-antiproton collisions. Predictions for Tevatron and
LHC energies are included.


title:
Time-dependent density-functional theory for electronic excitations in
  materials: basics and perspectives

abstract:
  Time-dependent density-functional theory (TDDFT) is widely used to describe
electronic excitations in complex finite systems with large numbers of atoms,
such as biomolecules and nanocrystals. The first part of this paper will give a
simple and pedagogical explanation, using a two-level system, which shows how
the basic TDDFT formalism for excitation energies works. There is currently an
intense effort underway to develop TDDFT methodologies for the charge and spin
dynamics in extended systems, to calculate optical properties of bulk and
nanostructured materials, and to study transport through molecular junctions.
The second part of this paper highlights some challenges and recent advances of
TDDFT in these areas. Two examples are discussed: excitonic effects in
insulators and intersubband plasmon excitations in doped semiconductor quantum
wells.


title: Scattering configuration spaces

abstract:
  For a compact manifold with boundary $X$ we introduce the
  $n$-fold scattering stretched product $X^n_{\text{sc}}$ which is a compact
manifold with corners for each $n,$ coinciding with the previously known cases
for $n=2,3.$ It is constructed by iterated blow up of boundary faces and
boundary faces of multi-diagonals in $X^n.$ The resulting space is shown to map
smoothly, by a b-fibration, covering the usual projection, to the lower
stretched products. It is anticipated that this manifold with corners, or at
least its combinatorial structure, is a universal model for phenomena on
asymptotically flat manifolds in which particle clusters emerge at infinity. In
particular this is the case for magnetic monopoles on $\mathbb{R}^3$ in which
case these spaces are closely related to compactifications of the moduli spaces
with the boundary faces mapping to lower charge idealized moduli spaces.


title: Regular induced subgraphs of a random graph

abstract:
  An old problem of Erd\H{o}s, Fajtlowicz and Staton asks for the order of a
largest induced regular subgraph that can be found in every graph on n
vertices. Motivated by this problem, we consider the order of such a subgraph
in a typical graph on n vertices, i.e., in a binomial random graph G(n,1/2). We
prove that with high probability a largest induced regular subgraph of G(n,1/2)
has about n^{2/3} vertices.


title:
On asymptotic stability of standing waves of discrete Schr\"odinger
  equation in $\Bbb Z$

abstract:
  We prove an analogue of a classical asymptotic stability result of standing
waves of the Schr\"odinger equation originating in work by Soffer and
Weinstein. Specifically, our result is a transposition on the lattice Z of a
result by Mizumachi and it involves a discrete Schr\"odinger operator H. The
decay rates on the potential are less stringent than in Mizumachi, since we
require for the potential $q\in \ell ^{1,1}$. We also prove $|e^{itH}(n,m)|\le
C < t > ^{-1/3}$ for a fixed $C$ requiring, in analogy to Goldberg and Schlag
only $q\in \ell ^{1,1}$ if $H$ has no resonances and $q\in \ell ^{1,2}$ if it
has resonances. In this way we ease the hypotheses on H contained in Pelinovsky
and Stefanov, which have a similar dispersion estimate.


title: Effective Field Equations of Brane-Induced Electromagnetism

abstract:
  Using a covariant embedding formalism, we find the effective field equations
for the Electromagnetism that emerge on branes in the context of
Dvali-Gabadadze-Porrati (DGP) braneworld scenario. Our treatment is essentially
geometrical. We start with Maxwell equations in five-dimensions and project
them into an arbitrary brane. The formalism is quite general and allows us to
consider curved bulk spaces and curved branes whose tension is not necessarily
null. The kinetic electromagnetic term induced on the world volume of the
brane, proper of DGP models, is incorporated in this formulation by means of an
appropriate match condition. We also give an estimate of each term of the
effective field equations and determine the domain in which the
four-dimensional Maxwell equations can be recovered in the brane.


title: Possible re-entrant superconductivity in EuFe2As2 under pressure

abstract:
  We studied the temperature-pressure phase diagram of EuFe2As2 by measurements
of the electrical resistivity. The antiferromagnetic spin-density-wave
transition at T_0 associated with the FeAs-layers is continuously suppressed
with increasing pressure, while the antiferromagnetic ordering temperature of
the Eu 2+ moments seems to be nearly pressure independent up to 2.6 GPa. Above
2 GPa a sharp drop of the resistivity, \rho(T), indicates the onset of
superconductivity at T_c \approx 29.5 K. Surprisingly, on further reducing the
temperature \rho(T) is increasing again and exhibiting a maximum caused by the
ordering of the Eu 2+ moments, a behavior which is reminiscent of re-entrant
superconductivity as it is observed in the ternary Chevrel phases or in the
rare-earth nickel borocarbides.


title: Efficient computation of resonance varieties via Grassmannians

abstract:
  Associated to the cohomology ring A of the complement X(A) of a hyperplane
arrangement A in complex m-space are the resonance varieties R^k(A). The most
studied of these is R^1(A), which is the union of the tangent cones at the
origin to the characteristic varieties of the fundamental group of X. R^1(A)
may be described in terms of Fitting ideals, or as the locus where a certain
Ext module is supported. Both these descriptions give obvious algorithms for
computation. In this note, we show that interpreting R^1(A) as the locus of
decomposable two-tensors in the Orlik-Solomon ideal leads to a description of
R^1(A) as the intersection of a Grassmannian with a linear space, determined by
the quadratic generators of the Orlik-Solomon ideal. This method is much faster
than previous alternatives.


title: Eigenvalues Estimates for the p-Laplace Operator on Manifolds

abstract:
  We obtain geometric estimates for the first eigenvalue and the fundamental
tone of the p-laplacian on manifolds in terms of admissible vector fields.
Also, we defined a new spectral invariant and we show its relation with the
geometry of the manifold.


title:
Coulomb corrections in quasi-elastic scattering: tests of the
  effective-momentum approximation

abstract:
  Coulomb corrections for quasi-elastic scattering of electrons by nuclei are
calculated using eikonal distorted waves. Corrections to the lowest-order
eikonal approximation are included in order to obtain accurate results.
Spin-dependent eikonal phase shifts are evaluated and they yield very small
corrections to the longitudinal and transverse cross sections at electron
energies of 500 MeV or higher. Because of this the Rosenbluth procedure is
accurate for separation of the longitudinal and transverse response functions.
The effective-momentum approximation is also found to be accurate with regard
to removal of the remaining Coulomb effects from the distorted waves.
Calculations are presented for electron scattering from Pb and Fe nuclei at
energies of 500 MeV and 800 MeV and momentum transfers q = 550 MeV/c and 900
MeV/c.


title:
Suppression of spin-torque in current perpendicular to the plane
  spin-valves by addition of Dy cap layers

abstract:
  We demonstrate that the addition of Dy capping layers in current
perpendicular to the plane giant magneto-resistive spin-valves can increase the
critical current density beyond which spin-torque induced instabilities are
observed by about a factor of three. Current densities as high as 5e7 A/cm2 are
measured provided that the electron current flows from the free to the
reference layer. While Dy capped samples exhibit nonmagnetic 1/f noise, it is
sufficiently small to be unimportant for read head operation at practical data
rates.


title: Piecewise polynomials on polyhedral complexes

abstract:
  For a d-dimensional polyhedral complex P, the dimension of the space of
piecewise polynomial functions (splines) on P of smoothness r and degree k is
given, for k sufficiently large, by a polynomial f(P,r,k) of degree d. When d=2
and P is simplicial, Alfeld and Schumaker determined a formula for all three
coefficients of f. However, in the polyhedral case, no formula is known. Using
localization techniques and specialized dual graphs associated to
codimension--2 linear spaces, we obtain the first three coefficients of
f(P,r,k), giving a complete answer when d=2.


title: Blocks of cyclotomic Hecke algebras and Khovanov-Lauda algebras

abstract:
  We construct an explicit isomorphism between blocks of cyclotomic Hecke
algebras and (sign-modified) Khovanov-Lauda algebras in type A. These
isomorphisms connect the categorification conjecture of Khovanov and Lauda to
Ariki's categorification theorem. The Khovanov-Lauda algebras are naturally
graded, which allows us to exhibit a non-trivial Z-grading on blocks of
cyclotomic Hecke algebras, including symmetric groups in positive
characteristic.


title: Proton-Rich Nuclear Statistical Equilibrium

abstract:
  Proton-rich material in a state of nuclear statistical equilibrium (NSE) is
one of the least studied regimes of nucleosynthesis. One reason for this is
that after hydrogen burning, stellar evolution proceeds at conditions of equal
number of neutrons and protons or at a slight degree of neutron-richness.
Proton-rich nucleosynthesis in stars tends to occur only when hydrogen-rich
material that accretes onto a white dwarf or neutron star explodes, or when
neutrino interactions in the winds from a nascent proto-neutron star or
collapsar-disk drive the matter proton-rich prior to or during the
nucleosynthesis. In this paper we solve the NSE equations for a range of
proton-rich thermodynamic conditions. We show that cold proton-rich NSE is
qualitatively different from neutron-rich NSE. Instead of being dominated by
the Fe-peak nuclei with the largest binding energy per nucleon that have a
proton to nucleon ratio close to the prescribed electron fraction, NSE for
proton-rich material near freeze-out temperature is mainly composed of Ni56 and
free protons. Previous results of nuclear reaction network calculations rely on
this non-intuitive high proton abundance, which this paper will explain. We
show how the differences and especially the large fraction of free protons
arises from the minimization of the free energy as a result of a delicate
competition between the entropy and the nuclear binding energy.


title: X-ray pulsars through the eyes of INTEGRAL

abstract:
  Recent results of the spectral and timing analysis of X-ray pulsars in hard
X-rays with the INTEGRAL observatory are reviewed. The evolution of the
cyclotron line energy with the source luminosity was studied in detail for the
first time for several sources. It was shown that for V0332+53 this dependence
is linear, but for 4U0115+63 and A0535+262 it is more complicated. There are
some evidences of the "reverse" evolution for GX301-2 and Her X-1, and no
evolution was found for Vela X-1, Cen X-3, etc. A strong dependence of the
pulse fraction on the energy and source luminosity was revealed and studied in
detail. A prominent feature in the pulse fraction dependence on the energy was
discovered near the cyclotron frequency for several bright sources. The
obtained results are compared with results of observations in standard X-rays
and briefly discussed in terms of current models; some preliminary explanations
are proposed.


title: Inductive Analysis on Singular Minimal Hypersurfaces

abstract:
  The present paper describes a way to relate Martin boundaries on spaces of
varying topology. This enables us to approach some detailed inductive analysis
of the eigenfunctions of conformal Laplacians on minimal hypersurfaces near
their singularities. This can directly be used resp. translated to understand
the way how such minimal hypersurfaces inherit positive scalar curvature from
their ambience resp. how to smooth singular minimal hypersurfaces to regular
hypersurfaces with positive mean curvature.


title:
Pseudo-nonstationarity in the scaling exponents of finite interval time
  series

abstract:
  The accurate estimation of scaling exponents is central in the observational
study of scale-invariant phenomena. Natural systems unavoidably provide
observations over restricted intervals; consequently a stationary stochastic
process (time series) can yield anomalous time variation in the scaling
exponents, suggestive of non-stationarity. The variance in the estimates of
scaling exponents computed from an interval of N observations is known for
finite variance processes to vary as ~1/N as N goes to infinity for certain
statistical estimators; however, the convergence to this behaviour will depend
on the details of the process, and may be slow. We study the variation in the
scaling of second order moments of the time series increments with N, for a
variety of synthetic and `real world' time series; and find that in particular
for heavy tailed processes, for realizable N, one is far from this 1/N limiting
behaviour. We propose a semi-empirical estimate for the minimum N needed to
make a meaningful estimate of the scaling exponents for model stochastic
processes and compare these with some `real world' time series.


title: Weak* continuous states on Banach algebras

abstract:
  We prove that if a unital Banach algebra $A$ is the dual of a Banach space
$\pd{A}$, then the set of weak* continuous states is weak* dense in the set of
all states on $A$. Further, weak* continuous states linearly span $\pd{A}$.


title:
Resonant nonlinear optics of backward waves in negative-index
  metamaterials

abstract:
  The extraordinary properties of resonant four-wave mixing of backward waves
in doped negative-index materials are investigated. The feasibility of
independent engineering of negative refractive index and nonlinear optical
response as well as quantum control of the nonlinear propagation process in
such composites is shown due to the coherent energy transfer from the control
to the signal field. Laser-induced transparency, quantum switching,
frequency-tunable narrow-band filtering, amplification, and realizing a
miniature mirrorless optical parametric generator of the entangled backward and
ordinary waves are among the possible applications of the investigated
processes.


title: Magnetic field measurements of O stars with FORS1 at the VLT

abstract:
  The presence of magnetic fields in O-type stars has been suspected for a long
time. The discovery of such fields would explain a wide range of well
documented enigmatic phenomena in massive stars, in particular cyclical wind
variability, H alpha emission variations, chemical peculiarity, narrow X-ray
emission lines and non-thermal radio/X-ray emission.
  To investigate the incidence of magnetic fields in O stars, we acquired 38
new spectropolarimetric observations with FORS1 (FOcal Reducer low dispersion
Spectrograph) mounted on the 8-m Kueyen telescope of the VLT.
  Spectropolarimetric observations have been obtained at different phases for a
sample of 13 O stars. 10 stars were observed in the spectral range 348-589nm,
HD36879 and HD148937 were observed in the spectral region 325-621nm, and
HD155806 was observed in both settings. To prove the feasibility of the FORS1
spectropolarimetric mode for the measurements of magnetic fields in hot stars,
we present in addition 12 FORS1 observations of the mean longitudinal magnetic
field in theta^1 Ori C and compare them with measurements obtained with the
MuSiCoS, ESPaDOnS and Narval spectropolarimeters.
  Most stars in our sample which have been observed on different nights show a
change of the magnetic field polarity, but a field at a significance level of
3sigma has been detected only in four stars, HD36879, HD148937, HD152408, and
HD164794. The largest longitudinal magnetic field, <B_z> = -276+-88G, was
detected in the Of?p star HD148937. We conclude that large-scale organised
magnetic fields with polar field strengths larger than 1kG are not widespread
among O-type stars.


title: Impossibility Proofs and Quantum Bit Commitment

abstract:
  The nature and scope of various impossibility proofs as they relate to
real-world situations are discussed. In particular, it is shown in words
without technical symbols how secure quantum bit commitment protocols may be
obtained with testing that exploits the multiple possibilities of cheating
entanglement formation.


title:
Systematic Measurements of Identified Particle Spectra in pp, d+Au and
  Au+Au Collisions from STAR

abstract:
  Identified charged particle spectra of $\pi^{\pm}$, $K^{\pm}$, $p$ and
$\pbar$ at mid-rapidity ($|y|<0.1$) measured by the $\dedx$ method in the
STAR-TPC are reported for $pp$ and d+Au collisions at $\snn = 200$ GeV and for
Au+Au collisions at 62.4 GeV, 130 GeV, and 200 GeV. ... [Shortened for arXiv
list. Full abstract in manuscript.]


title: Counting Wobbling Dual-Giants

abstract:
  We derive the BPS equations for D3-branes embedded in AdS_5 X S^5 that
preserve at least two supercharges. These are given in terms of conditions on
the pullbacks of some space-time differential four-forms. Solutions to our
equations are shown to describe all the known giant and dual-giant gravitons in
AdS_5 X S^5. We then argue that the configuration spaces of dual-giants can be
mapped to non-compact hyperbolic versions of complex projective spaces, in
contrast with the giants, whose configuration spaces have been mapped to
complex projective spaces. We quantize the configuration space of the 1/8-BPS
dual-giants with two angular momenta in AdS_5 and one angular momentum in S^5
and find agreement with the partition function in the literature obtained both
from counting appropriate 1/8-BPS configurations of giants and the boundary
gauge theory considerations.


title: On the low-energy behavior of the Adler function

abstract:
  The infrared behavior of the Adler function is examined by making use of a
recently derived integral representation for the latter. The obtained result
for the Adler function agrees with its experimental prediction in the entire
energy range. The inclusive $\tau$ lepton decay is studied in the framework of
the developed approach.


title: Supersymmetry beyond minimal flavour violation

abstract:
  We review the sources and phenomenology of non-minimal flavour violation in
the MSSM. We discuss in some detail the most important theoretical and
experimental constraints, as well as promising observables to look for
supersymmetric effects at the LHC and in the future. We emphasize the
sensitivity of flavour physics to the mechanism of supersymmetry breaking and
to new degrees of freedom present at fundamental scales, such as the grand
unification scale. We include a discussion of present data that may hint at
departures from the Standard Model.


title: Correctness is not enough

abstract:
  The usual aim of spreadsheet audit is to verify correctness. There are two
problems with this: first, it is often difficult to tell whether the
spreadsheets in question are correct, and second, even if they are, they may
still give the wrong results. These problems are explained in this paper, which
presents the key criteria for judging a spreadsheet and discusses how those
criteria can be achieved


title: Symmetries in collective neutrino oscillations

abstract:
  We discuss the relationship between a symmetry in the neutrino flavour
evolution equations and neutrino flavour oscillations in the collective
precession mode. This collective precession mode can give rise to spectral
swaps (splits) when conditions can be approximated as homogeneous and
isotropic. Multi-angle numerical simulations of supernova neutrino flavour
transformation show that when this approximation breaks down, non-collective
neutrino oscillation modes decohere kinematically, but the collective
precession mode still is expected to stand out. We provide a criterion for
significant flavour transformation to occur if neutrinos participate in a
collective precession mode. This criterion can be used to understand the
suppression of collective neutrino oscillations in anisotropic environments in
the presence of a high matter density. This criterion is also useful in
understanding the breakdown of the collective precession mode when neutrino
densities are small.


title: Gauging the cosmic microwave background

abstract:
  We provide a new derivation of the anisotropies of the cosmic microwave
background (CMB), and find an exact expression that can be readily expanded
perturbatively. Close attention is paid to gauge issues, with the motivation to
examine the effect of super-Hubble modes on the CMB. We calculate a transfer
function that encodes the behaviour of the dipole, and examine its
long-wavelength behaviour. We show that contributions to the dipole from
adiabatic super-Hubble modes are strongly suppressed, even in the presence of a
cosmological constant, contrary to claims in the literature. We also introduce
a naturally defined CMB monopole, which exhibits closely analogous
long-wavelength behaviour. We discuss the geometrical origin of this
super-Hubble suppression, pointing out that it is a simple reflection of
adiabaticity, and hence argue that it will occur regardless of the matter
content.


title: Effective Viscosity of a Dilute Suspension of Membrane-bound Inclusions

abstract:
  When particulate suspensions are sheared, perturbations in the shear flows
around the rigid particles increase the local energy dissipation, so that the
viscosity of the suspension is effectively higher than that of the solvent. For
bulk (three-dimensional) fluids, understanding this viscosity enhancement is a
classic problem in hydrodynamics that originated over a century ago with
Einstein's study of a dilute suspension of spherical particles.
\cite{Einstein1} In this paper, we investigate the analogous problem of the
effective viscosity of a suspension of disks embedded in a two-dimensional
membrane or interface. Unlike the hydrodynamics of bulk fluids, low-Reynolds
number membrane hydrodynamics is characterized by an inherent length scale
generated by the coupling of the membrane to the bulk fluids that surround it.
As a result, we find that the size of the particles in the suspension relative
to this hydrodynamic length scale has a dramatic effect on the effective
viscosity of the suspension. Our study also helps to elucidate the mathematical
tools needed to solve the mixed boundary value problems that generically arise
when considering the motion of rigid inclusions in fluid membranes.


title: Measurement of the dark matter velocity anisotropy in galaxy clusters

abstract:
  The internal dynamics of a dark matter structure may have the remarkable
property that the local temperature in the structure depends on direction. This
is parametrized by the velocity anisotropy beta which must be zero for relaxed
collisional structures, but has been shown to be non-zero in numerical
simulations of dark matter structures. Here we present a method to infer the
radial profile of the velocity anisotropy of the dark matter halo in a galaxy
cluster from X-ray observables of the intracluster gas. This non-parametric
method is based on a universal relation between the dark matter temperature and
the gas temperature which is confirmed through numerical simulations. We apply
this method to observational data and we find that beta is significantly
different from zero at intermediate radii. Thus we find a strong indication
that dark matter is effectively collisionless on the dynamical time-scale of
clusters, which implies an upper limit on the self-interaction cross-section
per unit mass sigma/m < 1 cm2/g. Our results may provide an independent way to
determine the stellar mass density in the central regions of a relaxed cluster,
as well as a test of whether a cluster is in fact relaxed.


title: Search for Gravitational Wave Bursts from Soft Gamma Repeaters

abstract:
  We present the results of a LIGO search for short-duration gravitational
waves (GWs) associated with Soft Gamma Repeater (SGR) bursts. This is the first
search sensitive to neutron star f-modes, usually considered the most efficient
GW emitting modes. We find no evidence of GWs associated with any SGR burst in
a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190
lesser events from SGR 1806-20 and SGR 1900+14 which occurred during the first
year of LIGO's fifth science run. GW strain upper limits and model-dependent GW
emission energy upper limits are estimated for individual bursts using a
variety of simulated waveforms. The unprecedented sensitivity of the detectors
allows us to set the most stringent limits on transient GW amplitudes published
to date. We find upper limit estimates on the model-dependent isotropic GW
emission energies (at a nominal distance of 10 kpc) between 3x10^45 and 9x10^52
erg depending on waveform type, detector antenna factors and noise
characteristics at the time of the burst. These upper limits are within the
theoretically predicted range of some SGR models.


title: First Results From The Taiwanese-American Occultation Survey (TAOS)

abstract:
  Results from the first two years of data from the Taiwanese-American
Occultation Survey (TAOS) are presented. Stars have been monitored
photometrically at 4 Hz or 5 Hz to search for occultations by small (~3 km)
Kuiper Belt Objects (KBOs). No statistically significant events were found,
allowing us to present an upper bound to the size distribution of KBOs with
diameters 0.5 km < D < 28 km.


title: Low-scale gaugino mediation, lots of leptons at the LHC

abstract:
  Low-scale gaugino mediation predicts that gauginos are significantly heavier
than scalar superpartners. In order of increasing mass the lightest
superpartners are the gravitino, right-handed sleptons and left-handed sleptons
(no light neutralino!). This implies that squark decay chains pass through one
or more sleptons and typical final states from squark and gluino production at
the LHC include multiple leptons. In addition, left-handed staus have large
branching fractions into right-handed staus and the Higgs. As an example, we
compute the spectrum of low-scale deconstructed gaugino mediation. In this
model gauginos acquire masses at tree level at 5 TeV while scalar masses are
generated radiatively from the gaugino masses.


title:
Spitzer's mid-infrared view on an outer Galaxy Infrared Dark Cloud
  candidate toward NGC 7538

abstract:
  Infrared Dark Clouds (IRDCs) represent the earliest observed stages of
clustered star formation, characterized by large column densities of cold and
dense molecular material observed in silhouette against a bright background of
mid-IR emission. Up to now, IRDCs were predominantly known toward the inner
Galaxy where background infrared emission levels are high. We present Spitzer
observations with the Infrared Camera Array toward object G111.80+0.58 (G111)
in the outer Galactic Plane, located at a distance of ~3 kpc from us and ~10
kpc from the Galactic center. Earlier results show that G111 is a massive, cold
molecular clump very similar to IRDCs. The mid-IR Spitzer observations
unambiguously detect object G111 in absorption. We have identified for the
first time an IRDC in the outer Galaxy, which confirms the suggestion that
cluster-forming clumps are present throughout the Galactic Plane. However,
against a low mid-IR back ground such as the outer Galaxy it takes some effort
to find them.


title: Dual Gravitons in AdS4/CFT3 and the Holographic Cotton Tensor

abstract:
  We argue that gravity theories in AdS4 are holographically dual to either of
two three-dimensional CFT's: the usual Dirichlet CFT1 where the fixed graviton
acts as a source for the stress-energy tensor, and a dual CFT2 with a fixed
dual graviton which acts as a source for a dual stress-energy tensor. The dual
stress-energy tensor is shown to be the Cotton tensor of the Dirichlet CFT. The
two CFT's are related by a Legendre transformation generated by a gravitational
Chern-Simons coupling. This duality is a gravitational version of
electric-magnetic duality valid at any radius r, where the renormalized
stress-energy tensor is the electric field and the Cotton tensor is the
magnetic field. Generic Robin boundary conditions lead to CFT's coupled to
Cotton gravity or topologically massive gravity. Interaction terms with CFT1
lead to a non-zero vev of the stress-energy tensor in CFT2 coupled to gravity
even after the source is removed. We point out that the dual graviton also
exists beyond the linearized approximation, and spell out some of the details
of the non-linear construction.


title:
The hierarchy problem, radion mass, localization of gravity and 4D
  effective Newtonian potential in string theory on $S^{1}/Z_{2}$

abstract:
  We present a systematical study of brane worlds in string theory on
$S^{1}/Z_{2}$. Starting with the toroidal compactification of the NS/NS sector
in (D+d) dimensions, we first obtain an effective $D$-dimensional action, and
then compactify one of the $(D-1)$ spatial dimensions by introducing two
orbifold branes as its boundaries. By combining the Gauss-Codacci and Lanczos
equations, we write down explicitly the general gravitational field equations
on each of the two branes, while using distribution theory we express the
matter field equations on the branes in terms of the discontinuities of the
first derivatives of the matter fields. Afterwards, we address three important
issues: (i) the hierarchy problem; (ii) the radion mass; and (iii) the
localization of gravity, the 4-dimensional Newtonian effective potential and
the Yukawa corrections due to the gravitational high-order Kaluza-Klein (KK)
modes. With a very conservative estimation, we find that the radion mass is of
the order of $10^{-2} GeV$. The gravity is localized on the visible brane, and
the spectrum of the gravitational KK modes is discrete and can be of the order
of TeV. The corrections to the 4-dimensional Newtonian potential from the
higher order of gravitational KK modes are exponentially suppressed and can be
safely neglected in current experiments. In an appendix, we also present a
systematical and pedagogical study of the Gauss-Codacci equations and Israel's
junction conditions across a (D-1)-dimensional hypersurface, which can be
either spacelike or timelike.


title:
Reply to: `Comment on: " 't Hooft vertices, partial quenching, and
  rooted staggered QCD" '

abstract:
  We reply to Creutz's comments on our paper " 't Hooft vertices, partial
quenching, and rooted staggered QCD." We show that his criticisms are incorrect
and result from a misunderstanding both of our work, and of the related work of
Adams.


title: Weighing matrices and optical quantum computing

abstract:
  Quantum computation in the one-way model requires the preparation of certain
resource states known as cluster states. We describe how the construction of
continuous-variable cluster states for optical quantum computing relate to the
existence of certain families of matrices. The relevant matrices are known as
weighing matrices, with a few additional constraints. We prove some results
regarding the structure of these matrices, and their associated graphs.