title: Optical emission from massive donors in ULX binary systems

abstract:
  We present evolutionary tracks of binary systems with high mass companion
stars and stellar-through-intermediate mass BHs. Using Eggleton's stellar
evolution code, we compute the luminosity produced by accretion from the donor
during its entire evolution. We compute also the evolution of the optical
spectrum of the binary system taking the disc contribution and irradiation
effects into account. The calculations presented here can be used to constrain
the properties of the donor stars in Ultraluminous X-ray Sources by comparing
their position on the HR or color-magnitude diagrams with the evolutionary
tracks of massive BH binaries. This approach may actually provide interesting
clues also on the properties of the binary system itself, including the BH
mass. We found that, on the basis of their position on the color-magnitude
diagram, some of the candidate counterparts considered can be ruled out and
more stringent constraints can be applied to the donor masses.


title: A classification of some Finsler connections and their applications

abstract:
  Some general Finsler connections are defined. Emphasis is being made on the
Cartan tensor and its derivatives. Vanishing of the hv-curvature tensors of
these connections characterizes Landsbergian, Berwaldian as well as Riemannian
structures. This view point makes it possible to give a smart representation of
connection theory in Finsler geometry and yields to a classification of Finsler
connections. Some practical applications of these connections are also
considered.


title: Progress in the evaluation of the anti-B -> X_s gamma decay rate at NNLO

abstract:
  The theoretical status of NNLO QCD corrections to the inclusive radiative
anti-B -> X_s gamma decay in the standard model is briefly overviewed. Emphasis
is put on recent results for three-loop fermionic corrections to matrix
elements of the most relevant four-quark operators.


title: Track finding in gamma conversions in CMS

abstract:
  A track finding algorithm has been developed for reconstruction of e+e-
pairs. It combines the information of the electromagnetic calorimeter with the
information provided by the Tracker. Results on reconstruction efficiency of
converted photons, as well as on fake rate are shown for single isolated
photons and for photons from H->gamma gamma events with pile-up events at 10^33
cm^-2 s^-1 LHC luminosity.


title: Fractional diffusion equation for aging and equilibrated random walks

abstract:
  We consider continuous time random walks (CTRW) and discuss situations
pertinent to aging. These correspond to the case when the initial state of the
system is known not at preparation (at $t=0$) but at the later instant of time
$t_1>0$ (intermediate-time initial condition). We derive the generalized aging
diffusion equation for this case and express it through a single memory kernel.
The results obtained are applied to the practically relevant case of the
equilibrated random walks. We moreover discuss some subtleties in the setup of
the aging subdiffusion problem and show that the behavior of the system depends
on what was taken as the intermediate-time initial condition: whether it was
coordinate of one particle given by measurement or the whole probability
distribution. The two setups lead to different predictions for the evolution of
a system. This fact stresses the necessity of a precise definition of aging
statistical ensembles.


title: Resonant mode flopping in modulated waveguiding structures

abstract:
  We put forward the concept of resonant, Rabi-like flopping and adiabatic
transitions between confined light modes in properly modulated multimode
waveguides. The phenomenon is shown to take place in both, the linear and the
nonlinear regimes. In addition, we find that the mode transitions occur not
only in simple geometries, but also in complex confining multimode structures.
The phenomenon is analogous to the familiar stimulated state transitions that
occur in multilevel quantum systems.


title:
First Stiefel-Whitney class of real moduli spaces of stable maps to a
  convex surface

abstract:
  Let $(X,c_X)$ be a convex projective surface equipped with a real structure.
The space of stable maps $\bar{\mathcal{M}}_{0,k}(X,d)$ carries different real
structures induced by $c_X$ and any order two element $\tau$ of permutation
group $S_k$ acting on marked points. Each corresponding real part
$\R_{\tau}\bar{\mathcal{M}}_{0,k}(X,d)$ is a real normal projective variety. As
the singular locus is of codimension bigger than two, these spaces thus carry a
first Stiefel-Whitney class for which we determine a representative in the case
$k=c_1(X)d-1$ where $c_1(X)$ is the first Chern class of $X$. Namely, we give a
homological description of these classes in term of the real part of boundary
divisors of the space of stable maps.


title: SFitter: Reconstructing the MSSM Lagrangian from LHC data

abstract:
  Once supersymmetry is found at the LHC, the question arises what are the
fundamental parameters of the Lagrangian. The answer to this question should
thereby not be biased by assumptions on high-scale models. SFitter is a tool
designed for this task. Taking LHC (and possibly ILC) data as input it scans
the TeV-scale MSSM parameter space using its new weighted Markov chain
technique. Using this scan it determines a list of best-fitting parameter
points. Additionally a log-likelihood map is calculated, which can be reduced
to lower-dimensional Frequentist's profile likelihoods or Bayesian probability
maps.


title: On the Whitehead spectrum of the circle

abstract:
  The seminal work of Waldhausen, Farrell and Jones, Igusa, and Weiss and
Williams shows that the homotopy groups in low degrees of the space of
homeomorphisms of a closed Riemannian manifold of negative sectional curvature
can be expressed as a functor of the fundamental group of the manifold. To
determine this functor, however, it remains to determine the homotopy groups of
the topological Whitehead spectrum of the circle. The cyclotomic trace of B
okstedt, Hsiang, and Madsen and a theorem of Dundas, in turn, lead to an
expression for these homotopy groups in terms of the equivariant homotopy
groups of the homotopy fiber of the map from the topological Hochschild
T-spectrum of the sphere spectrum to that of the ring of integers induced by
the Hurewicz map. We evaluate the latter homotopy groups, and hence, the
homotopy groups of the topological Whitehead spectrum of the circle in low
degrees. The result extends earlier work by Anderson and Hsiang and by Igusa
and complements recent work by Grunewald, Klein, and Macko.


title:
Polarization Retarder with Cylindrical-Symmetry for Radially Polarized
  Light

abstract:
  We demonstrate a cylindrically-symmetric polarization retarder for generating
exact radially polarized light. It involves an uni-axial crystal whose
crystallographic optics axis is aligned to its optical axis. This method offers
high power-handling capability


title:
Spatially extended PAHs in circumstellar disks around T Tauri and Herbig
  Ae stars

abstract:
  Our aim is to determine the presence and location of the emission from
polycyclic aromatic hydrocarbons (PAHs) towards low and intermediate mass young
stars with disks using large aperture telescopes.
  VLT-VISIR N-band spectra and VLT-ISAAC and VLT-NACO L-band spectra of 29
sources are presented, spectrally resolving the 3.3, 8.6, 11.2, and 12.6 micron
PAH features. Spatial-extent profiles of the features and the continuum
emission are derived and used to associate the PAH emission with the disks. The
results are discussed in the context of recent PAH-emission disk models.
  The 3.3, 8.6, and 11.2 micron PAH features are detected toward a small
fraction of the T Tauri stars, with typical upper limits between 1E-15 and
5E-17 W/m^2. All 11.2 micron detections from a previous Spitzer survey are
confirmed with (tentative) 3.3 micron detections, and both the 8.6 and the 11.2
micron features are detected in all PAH sources. For 6 detections, the spatial
extent of the PAH features is confined to scales typically smaller than
0.12-0.34'', consistent with the radii of 12-60 AU disks at their distances
(typically 150 pc). For 3 additional sources, WL 16, HD 100546, and TY CrA, one
or more of the PAH features are more extended than the hot dust continuum of
the disk, whereas for Oph IRS 48, the size of the resolved PAH emission is
confirmed as smaller than for the large grains. For HD 100546, the 3.3 micron
emission is confined to a small radial extent of 12 +- 3 AU, most likely
associated with the outer rim of the gap in this disk. Gaps with radii out to
10-30 AU may also affect the observed PAH extent for other sources. For both
Herbig Ae and T Tauri stars, the small measured extents of the 8.6 and 11.2
micron features are consistent with larger (>= 100 carbon atoms) PAHs.


title:
Ferromagnetic resonance study of polycrystalline Fe_{1-x}V_x alloy thin
  films

abstract:
  Ferromagnetic resonance has been used to study the magnetic properties and
magnetization dynamics of polycrystalline Fe$_{1-x}$V$_{x}$ alloy films with
$0\leq x < 0.7$. Films were produced by co-sputtering from separate Fe and V
targets, leading to a composition gradient across a Si substrate. FMR studies
were conducted at room temperature with a broadband coplanar waveguide at
frequencies up to 50 GHz using the flip-chip method. The effective
demagnetization field $4 \pi M_{\mathrm{eff}}$ and the Gilbert damping
parameter $\alpha$ have been determined as a function of V concentration. The
results are compared to those of epitaxial FeV films.


title: A high fidelity approximation of radial polarization conversion

abstract:
  We report a high fidelity (>90%) approximation of radial polarization
conversion using a birefringent lens. It offers the advantages of low-cost,
easy fabrication, alignment robustness and high laser power handling
capability.


title:
Fermionic representation for the ferromagnetic Kondo lattice model --
  diagrammatic study of spin-charge coupling effects on magnon excitations

abstract:
  A purely fermionic representation is introduced for the ferromagnetic Kondo
lattice model which allows conventional diagrammatic tools to be employed to
study correlation effects. Quantum 1/S corrections to magnon excitations are
investigated using a systematic inverse-degeneracy expansion scheme which
incorporates correlation effects in the form of self-energy and vertex
corrections, while explicitly preserving the continuous spin-rotation symmetry.
Magnon self-energy is studied in the full range of interaction strength, and
shown to result in strong magnon damping and anomalous softening for zone
boundary modes, which accounts for several zone-boundary anomalies observed in
recent spin-wave measurements of ferromagnetic manganites.


title:
Nonequilibrium critical dynamics of the two-dimensional Ising model
  quenched from a correlated initial state

abstract:
  The universality class, even the order of the transition, of the
two-dimensional Ising model depends on the range and the symmetry of the
interactions (Onsager model, Baxter-Wu model, Turban model, etc.), but the
critical temperature is generally the same due to self-duality. Here we
consider a sudden change in the form of the interaction and study the
nonequilibrium critical dynamical properties of the nearest-neighbor model. The
relaxation of the magnetization and the decay of the autocorrelation function
are found to display a power law behavior with characteristic exponents that
depend on the universality class of the initial state.


title:
Precision extraction of a_nn from pi- d --> n n gamma using chiral
  perturbation theory

abstract:
  The neutron-neutron scattering length a_nn provides a sensitive probe of
charge-symmetry breaking in the strong interaction. Here we summarize our
recent efforts to use chiral perturbation theory in order to systematically
relate a_nn to the shape of the neutron spectrum in the reaction pi- d --> n n
gamma. In particular we show how the chiral symmetry of QCD relates this
process to low-energy electroweak reactions such as p p --> d e+ nu_e. This
allows us to reduce the uncertainty in the extracted a_nn (mainly due to
short-distance physics in the two-nucleon system) by a factor of more than
three, to <0.05 fm. We also report first results on the impact that two-nucleon
mechanisms of chiral order P^4 have on the pi- d --> n n gamma neutron
spectrum.


title:
Quantum dynamics in phase space: From coherent states to the Gaussian
  representation

abstract:
  We give an outlook on the future of coherence theory and many-body quantum
dynamics as experiments develop in the arena of ultra-cold atoms. Novel results
on quantum heating of center-of-mass temperature in evaporative cooling and
simulation methods for long-range interactions are obtained, using positive-P
phase-space techniques.


title:
Schr\"odinger operator with periodic plus compactly supported potentials
  on the half-line

abstract:
  We consider the Schr\"odinger operator $H$ with a periodic potential $p$ plus
a compactly supported potential $q$ on the half-line. We prove the following
results: 1) a forbidden domain for the resonances is specified, 2) asymptotics
of the resonance-counting function is determined, 3) in each nondegenerate gap
$\g_n$ for $n$ large enough there is exactly an eigenvalue or an antibound
state, 4) the asymptotics of eigenvalues and antibound states are determined at
high energy, 5) the number of eigenvalues plus antibound states is odd $\ge 1$
in each gap,
  6) between any two eigenvalues there is an odd number $\ge 1$ of antibound
states, 7) for any potential $q$ and for any sequences $(\s_n)_{1}^\iy, \s_n\in
\{0,1\}$ and $(\vk_n)_1^\iy\in \ell^2, \vk_n\ge 0$, there exists a potential
$p$ such that each gap length $|\g_n|=\vk_n, n\ge 1$ and $H$ has exactly $\s_n$
eigenvalues and $1-\s_n$ antibound state in each gap $\g_n\ne \es$ for $n$
large enough, 8) if unperturbed operator (at $q=0$) has infinitely many virtual
states, then for any sequence $(\s)_1^\iy, \s_n\in \{0,1\}$, there exists a
potential $q$ such that $H$ has $\s_n$ bound states and $1-\s_n$ antibound
states in each gap open $\g_n$ for $n$ large enough.


title: Marchenko-Ostrovski mappings for periodic Jacobi matrices

abstract:
  We consider the 1D periodic Jacobi matrices. The spectrum of this operator is
purely absolutely continuous and consists of intervals separated by gaps. We
solve the inverse problem (including characterization) in terms of vertical
slits on the quasimomentum domain . Furthermore, we obtain a priori two-sided
estimates for vertical slits in terms of Jacoby matrices.


title:
Fermion masses and neutrino mixing in an U(1)_H flavor symmetry model
  with hierarchical radiative generation for light charged fermion masses

abstract:
  I report the analysis performed on fermion masses and mixing, including
neutrino mixing, within the context of a model with hierarchical radiative mass
generation mechanism for light charged fermions, mediated by exotic scalar
particles at one and two loops, respectively, meanwhile the neutrinos get
Majorana mass terms at tree level through the Yukawa couplings with two SU(2)_L
Higgs triplets. All the resulting mass matrices in the model, for the u, d, and
e fermion charged sectors, the neutrinos and the exotic scalar particles, are
diagonalized in exact analytical form. Quantitative analysis shows that this
model is successful to accommodate the hierarchical spectrum of masses and
mixing in the quark sector as well as the charged lepton masses. The lepton
mixing matrix, V_{PMNS}, is written completely in terms of the neutrino masses
m_1, m_2, and m_3. Large lepton mixing for \theta_{12} and \theta_{23} is
predicted in the range of values 0.7 \lesssim \sin^22\theta_{12}\lesssim 0.7772
and 0.87 \lesssim \sin^22\theta_{23} \lesssim 0.9023 by using 0.033 \lesssim
s_{13}^2 \lesssim 0.04. These values for lepton mixing are consistent with 3
\sigma allowed ranges provided by recent global analysis of neutrino data
oscillation. From \Delta m_{\text{sol}}^2 bounds, neutrino masses are predicted
in the range of values m_1 \thickapprox (1.706 - 2.494) x 10^{- 3} eV, m_2
\thickapprox (6.675 - 12.56) x 10^{- 3} eV, and m_3 \thickapprox (1.215 -
2.188) x 10^{- 2} eV, respectively. The above allowed lepton mixing leads to
the quak-lepton complementary relations \theta_{12}^{CKM} + \theta_{12}^{PMNS}
\thickapprox 41.543^{\circ} - 44.066^{\circ} and
\theta_{23}^{CKM}+\theta_{23}^{PMNS}\thickapprox 36.835^{\circ} -
38.295^{\circ}.


title: Folksonomies and clustering in the collaborative system CiteULike

abstract:
  We analyze CiteULike, an online collaborative tagging system where users
bookmark and annotate scientific papers. Such a system can be naturally
represented as a tripartite graph whose nodes represent papers, users and tags
connected by individual tag assignments. The semantics of tags is studied here,
in order to uncover the hidden relationships between tags. We find that the
clustering coefficient reflects the semantical patterns among tags, providing
useful ideas for the designing of more efficient methods of data classification
and spam detection.


title: Topological entropies of equivalent smooth flows

abstract:
  Two flows defined on a smooth manifold are equivalent if there exists a
homeomorphism of the manifold that sends each orbit of one flow onto an orbit
of the other flow while preserving the time orientation. The topological
entropy of a flow is defined as the entropy of its time-1 map. While
topological entropy is an invariant for equivalent homeomorphisms, finite
non-zero topological entropy for a flow cannot be an invariant because its
value is affected by time reparameterization. However, 0 and $\infty$
topological entropy are invariants for equivalent flows without fixed points.
  In equivalent flows with fixed points there exists a counterexample,
constructed by Ohno, showing that neither 0 nor $\infty$ topological entropy is
preserved by equivalence. The two flows constructed by Ohno are suspensions of
a transitive subshift and thus are not differentiable. Note that a
differentiable flow on a compact manifold cannot have $\infty$ entropy. These
facts led Ohno in 1980 to ask the following: "Is 0 topological entropy an
invariant for equivalent differentiable flows?"
  In this paper, we construct two equivalent $C^\infty$ smooth flows with a
singularity, one of which has positive topological entropy while the other has
zero topological entropy. This gives a negative answer to Ohno's question in
the class $C^\infty$.


title: Overhauser effect in individual InP/GaInP dots

abstract:
  Sizable nuclear spin polarization is pumped in individual InP/GaInP dots in a
wide range of external magnetic fields B_ext=0-5T by circularly polarized
optical excitation. We observe nuclear polarization of up to ~40% at Bext=1.5T
and corresponding to an Overhauser field of ~1.2T. We find a strong feedback of
the nuclear spin on the spin pumping efficiency. This feedback, produced by the
Overhauser field, leads to nuclear spin bi-stability at low magnetic fields of
Bext=0.5-1.5T. We find that the exciton Zeeman energy increases markedly, when
the Overhauser field cancels the external field. This counter-intuitive result
is shown to arise from the opposite contribution of the electron and hole
Zeeman splittings to the total exciton Zeeman energy.


title: Experimental Precision Tests for the Electroweak Standard Model

abstract:
  This paper contains a review of recent precision measurements of electroweak
observables and resulting tests of the electroweak Standard Model.


title: Magnetic field evolution in neutron stars

abstract:
  Neutron stars contain persistent, ordered magnetic fields that are the
strongest known in the Universe. However, their magnetic fluxes are similar to
those in magnetic A and B stars and white dwarfs, suggesting that flux
conservation during gravitational collapse may play an important role in
establishing the field, although it might also be modified substantially by
early convection, differential rotation, and magnetic instabilities. The
equilibrium field configuration, established within hours (at most) of the
formation of the star, is likely to be roughly axisymmetric, involving both
poloidal and toroidal components. The stable stratification of the neutron star
matter (due to its radial composition gradient) probably plays a crucial role
in holding this magnetic structure inside the star. The field can evolve on
long time scales by processes that overcome the stable stratification, such as
weak interactions changing the relative abundances and ambipolar diffusion of
charged particles with respect to neutrons. These processes become more
effective for stronger magnetic fields, thus naturally explaining the magnetic
energy dissipation expected in magnetars, at the same time as the longer-lived,
weaker fields in classical and millisecond pulsars.


title:
Effective Action, Conformal Anomaly and the Issue of Quadratic
  Divergences

abstract:
  For massless $\phi^4$ theory, we explicitly compute the lowest order
non-local contributions to the one-loop effective action required for the
determination of the trace anomaly. Imposing exact conformal invariance of the
local part of the effective action, we argue that the issue of quadratic
divergences does not arise in a theory where exact conformal symmetry is only
broken by quantum effects. Conformal symmetry can thus replace low energy
supersymmetry as a possible guide towards stabilizing the weak scale and
solving the hierarchy problem, if (i) there are no intermediate scales between
the weak scale and the Planck scale, and (ii) the running couplings exhibit
neither Landau poles nor instabilities over this whole range of energies.


title:
Interplay of causticity and vorticality within the complex quantum
  Hamilton-Jacobi formalism

abstract:
  Interference dynamics is analyzed in the light of the complex quantum
Hamilton-Jacobi formalism, using as a working model the collision of two
Gaussian wave packets. Though simple, this model nicely shows that interference
in quantum scattering processes gives rise to rich dynamics and trajectory
topologies in the complex plane, both ruled by two types of singularities:
caustics and vortices, where the former are associated with the regime of free
wave-packet propagation, and the latter with the collision (interference)
process. Furthermore, an unambiguous picture connecting the complex and real
frameworks is also provided and discussed.


title: Coherence and Correlations in Atom Lasers

abstract:
  We review and characterize the quantum coherence measures that are most
useful for quantum gases, including Bose-Einstein condensates (BEC) and
ultra-cold fermions, and outline how to calculate these in the typically
dynamical environment of an interacting multi-mode quantum gas.


title:
Relativistic time dilatation and the spectrum of electrons emitted by 33
  TeV lead ions penetrating thin foils

abstract:
  We study the energy distribution of ultrarelativistic electrons produced when
a beam of 33 TeV Pb$^{81+}$(1s) ions penetrates a thin Al foil. We show that,
because of a prominent role of the excitations of the ions inside the foil
which becomes possible due to the relativistic time dilatation, the width of
this distribution can be much narrower compared to the case when the ions
interact with rarefied gaseous targets. We also show that a very similar shape
of the energy distribution may arise when 33 TeV Pb$^{82+}$ ions penetrate a
thin Au foil. These results shed some light on the origin of the very narrow
electron energy distributions observed experimentally about a decade ago.


title: Does a particle swept by a turbulent liquid diffuse?

abstract:
  Since the famous 1926 paper by Richardson, the relative diffusion of two
particles in a turbulent liquid has attracted a lot of interest. The motion of
a single particle on the other hand is usually considered not to be especially
interesting. The widely accepted picture is that the velocity of the particle
has short-range correlations in time, resulting in motion that is diffusive on
time scales large compared to the correlation time. We find, however, that the
correlation time is infinite and that the square displacement, F, is not linear
in the traversed time, T, which would correspond to diffusion, but rather F is
proportional to T^6/5. Namely, the motion is slightly super diffusive.


title:
Current saturation and Coulomb interactions in organic single-crystal
  transistors

abstract:
  Electronic transport through rubrene single-crystal field effect transistors
(FETs) is investigated experimentally in the high carrier density regime (n ~
0.1 carrier/molecule). In this regime, we find that the current does not
increase linearly with the density of charge carriers, and tends to saturate.
At the same time, the activation energy for transport unexpectedly increases
with increasing n. We perform a theoretical analysis in terms of a well-defined
microscopic model for interacting Frohlich polarons, that quantitatively
accounts for our experimental observations. This work is particularly
significant for our understanding of electronic transport through organic FETs.


title: Two-photon decay of heavy quarkonium from heavy-quark spin symmetry

abstract:
  With the recent measurements on $\eta_{c}$ and $\eta_{c}^{\prime}$ at CLEO,
Babar and Belle, and with the prospect of finding the $\eta_{b}$ at the
Tevatron, it seems appropriate to have another look at the two-photon decay of
heavy quarkonium from the standpoint of an effective Lagrangian based on local
operator expansion and heavy-quark spin symmetry. In this talk, I would like to
discuss a recent work on the two-photon decay rates of ground states and
excited states of $\eta_c$ and $\eta_b$ using the local operator expansion
approach and heavy-quark spin symmetry and taking into account the
binding-energy. We find that the predicted two-photon width for $\eta_c$ agrees
well with experiment, but the predicted value for $\eta_c(2S)$ is twice larger
than the CLEO estimation. We point out that the essentially model-independent
ratio of $\eta_b$ two-photon width to the $\Upsilon$ leptonic width and the
$\eta_b $ two-photon width could be used to extract the strong coupling
constant $\alpha_s$ .


title:
A synchrotron self-Compton scenario for the very high energy gamma-ray
  emission of the radiogalaxy M87

abstract:
  M87 is the first extragalactic source detected in the TeV range that is not a
blazar. With the increasing performances of ground-based Cherenkov telescopes,
we can now probe the variability in the gamma-ray flux at small timescales,
thus putting strong constraints on the size of the emitting zone. A
modification of standard emission models of TeV blazars appears necessary to
account for the gamma-ray observations despite this misalignment. We explain
TeV gamma-ray spectra and fast variability of M87 by invoking an emission zone
close to the central supermassive black hole, which is filled with several
plasma blobs moving in the large opening angle of the jet formation zone. We
develop a new multi-blob synchrotron self-Compton (SSC) model with emitting
blobs beyond the Alfven surface in the jet, at a distance of about 100 r_g from
the central engine. This model is explicitly adapted to deal with large viewing
angles and moderate values of the Lorentz factor inferred from (general
relativistic) magnetohydrodynamic models of jet formation. This scenario can
account for the recent gamma-ray observations of M87 made by the High Energy
Stereoscopic System (H.E.S.S.) telescope array. We find individual blob radii
of about 10^{14} cm, which is compatible with the variability on timescales of
days recently reported by the H.E.S.S. collaboration and is of the order of the
black hole gravitational radius. Predictions of the very high energy emission
for three other sources with extended optical or X-ray jet which could be
misaligned blazars still with moderate beaming are presented for one Seyfert 2
radiogalaxy, namely Cen A, one peculiar BL Lac, PKS 0521-36, and one quasar, 3C
273.


title: Consistency of trace norm minimization

abstract:
  Regularization by the sum of singular values, also referred to as the trace
norm, is a popular technique for estimating low rank rectangular matrices. In
this paper, we extend some of the consistency results of the Lasso to provide
necessary and sufficient conditions for rank consistency of trace norm
minimization with the square loss. We also provide an adaptive version that is
rank consistent even when the necessary condition for the non adaptive version
is not fulfilled.


title: NA57 main results

abstract:
  The CERN NA57 experiment was designed to study the production of strange and
multi-strange particles in heavy ion collisions at SPS energies; its physics
programme is essentially completed. A review of the main results is presented.


title: Local SU(5) Unification in 6D from the Heterotic String

abstract:
  We present a six-dimensional T^2/Z_2 orbifold model which arises as an
intermediate step in the compactification of the heterotic string to the MSSM.
The orbifold contains two pairs of inequivalent fixed points, with unbroken
local gauge groups SU(5) and SU(2)xSU(4), respectively, the intersection of
which gives the standard model gauge group. All bulk and brane anomalies are
cancelled by the Green--Schwarz mechanism. At each SU(5) fixed point, there is
a localised \bar{5}+10 standard model generation, while the third generation
and the Higgs fields come in split bulk multiplets due to the breaking of SU(5)
at the other fixed point.


title: CP asymmetries at D0

abstract:
  Using two independent measurements of the semileptonic CP asymmetry in the
$B_s$ system, we constrain the CP violating phase of the $B_s$ system to be
$\phi_s = -0.70^{+0.47}_{-0.39}$. The data sample corresponds to an integrated
luminosity of 1.1 fb$^{-1}$ accumulated with D0 detector at the Fermilab
Tevatron collider. We also measure the direct CP violating asymmetry in the
decay $B^+ \to J/\psi K^+$ to be $A_{CP}(B^+ \to J/\psi K^+) = +0.0067 \pm
0.0074$(stat)$\pm0.0026$(syst). The data corresponds to an integrated
luminosity of 1.6 fb$^{-1}$.


title: Generating models for temporal representations

abstract:
  We discuss the use of model building for temporal representations. We chose
Polish to illustrate our discussion because it has an interesting aspectual
system, but the points we wish to make are not language specific. Rather, our
goal is to develop theoretical and computational tools for temporal model
building tasks in computational semantics. To this end, we present a
first-order theory of time and events which is rich enough to capture
interesting semantic distinctions, and an algorithm which takes minimal models
for first-order theories and systematically attempts to ``perturb'' their
temporal component to provide non-minimal, but semantically significant,
models.


title: Exotic hadrons and SU(3) chiral dynamics

abstract:
  We explore a possibility to generate exotic hadrons dynamically in the
scattering of hadrons. The s-wave scattering amplitude of an arbitrary hadron
with the Nambu-Goldstone boson is constructed so as to satisfy the unitarity
condition and the chiral low energy theorem. We find that the chiral
interaction for the exotic channels is in most cases repulsive, and that the
strength of the possible attractive interaction is uniquely determined. We show
that the attractive interaction in exotic channels is not strong enough to
generate a bound state, while the interaction in nonexotic channel generate
bound states which are considered to be the origin of some resonances observed
in nature.


title:
Diffraction in low-energy electron scattering from DNA: bridging gas
  phase and solid state theory

abstract:
  Using high-quality gas phase electron scattering calculations and multiple
scattering theory, we attempt to gain insights on the radiation damage to DNA
induced by secondary low-energy electrons in the condensed phase, and to bridge
the existing gap with the gas phase theory and experiments. The origin of
different resonant features (arising from single molecules or diffraction) is
discussed and the calculations are compared to existing experiments in thin
films.


title:
Comparison between 2-D and 3-D codes in dynamical simulations of gas
  flow in barred galaxies

abstract:
  Context: One of the ways to determine the contribution of the dark halo to
the gravitational potential of a galaxy is the study of non-circular
(streaming) motions and the associated gas shocks in the bar region. These
motions, determined by the potential in the inner parts, can break the
disk-halo degeneracy. Here, two main fluid dynamical approaches have been
chosen to model the non-circular motions in the bar region; a 2-D Eulerian grid
code for an isothermal gas (FS2) and a 3-D smoothed particle hydrodynamic code
(N-body/SPH). Aims: The aim of this paper is to compare and quantify the
differences of the gas flows in rotating barred potential obtained using two
different fluid dynamical approaches. We analyse the effect of using 2-D and a
3-D codes in the calculation of gas flow in barred galaxies and to which extend
the results are affected by the code. To do this, we derive the velocity field
and density maps for the mass model of NGC 4123 using a 3-D N-body/SPH code and
compare the results to the previous 2-D Eulerian grid code results. Methods:
Numerical modelling, 3-D N-body/SPH simulations Results: The global velocity
field and the gas distribution is very similar in both models. The study shows
that the position and strength of the shocks developed in the SPH simulations
do not vary significantly compared to the results derived from the 2-D FS2
code. The largest velocity difference across the shock is 20\kms between the
2-D and 3-D fluid dynamical models. Conclusions: The results obtained in the
studies deriving the dark matter content of barred galaxies using the bar
streaming motions and strength and position of shocks are robust to the fluid
dynamical model used. The effect of 2-D and 3-D modelling can be neglected in
this type of studies.


title:
An asymptotic integral representation for Carleman orthogonal
  polynomials

abstract:
  In this paper we investigate the asymptotic behavior of polynomials that are
orthonormal over the interior domain of an analytic Jordan curve L with respect
to area measure. We prove that, inside L, these polynomials behave
asymptotically like a sequence of certain integrals involving the canonical
conformal map of the exterior of L onto the exterior of the unit circle and
certain meromorphic kernel function defined in terms of a conformal map of the
interior of L onto the unit disk. The error term in the integral representation
is proven to decay geometrically and sufficiently fast, allowing us to obtain
more precise asymptotic formulas for the polynomials under certain additional
geometric considerations. These formulas yield, in turn, fine results on the
location, limiting distribution and accumulation points of the zeros of the
polynomials.


title: Renormalisable SO(10) models and neutrino masses and mixing

abstract:
  We discuss some recent developments in SUSY Grand Unified Theories based on
the gauge group SO(10). Considering renormalisable Yukawa couplings, we present
ways to accommodate quark and lepton masses and and mixings.


title: Observation of an unexpected hardening in the spectrum of GRB 021206

abstract:
  GRB 021206 is one of the brightest GRBs ever observed. Its prompt emission,
as measured by RHESSI, shows an unexpected spectral feature. The spectrum has a
peak energy of about 700 keV and can be described by a Band function up to 4.5
MeV. Above 4.5 MeV, the spectrum hardens again, so that the Band function fails
to fit the whole RHESSI energy range up to 17 MeV. Nor does the sum of a
blackbody function plus a power law, even though such a function can describe a
spectral hardening. The cannonball model on the other hand predicts such a
hardening, and we found that it fits the spectrum of GRB 021206 perfectly. We
also analysed other strong GRBs observed by RHESSI, namely GRBs 020715, 021008,
030329, 030406, 030519B, 031027, 031111. We found that all their spectra can be
fit by the cannonball model as well as by a Band function.


title: Nonequilibrium valley polarization in graphene nanoconstrictions

abstract:
  We recently shown, using tight-binding calculations, that nonequilibrium
valley polarization can be realized in graphene, when the current is injected
through "valley filter": a ballistic point contact with zigzag edges. Here we
demonstrate, that the effect is surprisingly robust against changing the
crystallographic orientation of the filter axis. Namely, the output current
remains polarized unless a point contact has perfect armchair edges, at which
two subblattices are equally represented. The polarization is inverted when the
filter orientation crosses the amchair line and, subsequently, dominating
subblattice index of terminal atoms changes. In a bended graphene strip, the
valley-polarized current can be directed towards one edge providing a
theoretical possibility to observe a zero-magnetic-field analogue of the
well-known Hall effect. For the valley valve, build of two valley filters in
series and controlled elecrostatically by a gate voltage, the
conductance-to-gate characteristic is inverted when $\pi/3$ vertex is placed
between two filters.


title: Universal derived equivalences of posets of cluster tilting objects

abstract:
  We show that for two quivers without oriented cycles related by a BGP
reflection, the posets of their cluster tilting objects are related by a simple
combinatorial construction, which we call a flip-flop.
  We deduce that the posets of cluster tilting objects of derived equivalent
path algebras of quivers without oriented cycles are universally derived
equivalent. In particular, all Cambrian lattices corresponding to the various
orientations of the same Dynkin diagram are universally derived equivalent.


title:
A Feynman-Kac-type formula for the deterministic and stochastic wave
  equations

abstract:
  We establish a probabilistic representation for a wide class of linear
deterministic p.d.e.s with potential term, including the wave equation in
spatial dimensions 1 to 3. Our representation applies to the heat equation,
where it is related to the classical Feynman-Kac formula, as well as to the
telegraph and beam equations. If the potential is a (random) spatially
homogeneous Gaussian noise, then this formula leads to an expression for the
moments of the solution.


title: Non-perturbative renormalisation of four-fermion operators in N_f=2 QCD

abstract:
  We present results for the non-perturbative renormalisation of four-fermion
operators with two flavours of dynamical quarks. We consider both fully
relativistic left current-left current operators, and a full basis for $\Delta
B=2$ operators with static heavy quarks. The renormalisation group running of
the operators to high energy scales is computed in the continuum limit for a
family of Schroedinger Functional renormalisation schemes, via standard finite
size scaling techniques. The total renormalisation factors relating
renormalisation group invariant to bare operators are computed for a choice of
lattice regularisations.


title:
First quenched results for the matrix elements of the B_{B_s} mixing
  parameter in the static limit from tmQCD

abstract:
  We report on a non-perturbative study of the scale-dependent renormalization
factors of a multiplicatively renormalizable basis of Delta B=2 parity-odd
four-fermion operators in quenched lattice QCD. We also present some
preliminary results of the matrix elements related to the mixing parameter of
the B_s-meson. In our lattice formulation, the heavy quark is treated in the
static approximation, while the strange one belongs to a doublet of twisted
mass fermions at full twist, i.e. with twist angle alpha=pi/2. In this
framework, the parity-even Delta B=2 four-fermion operators responsible for the
mixing are rotated onto a linear combination of parity-odd operators in the
above-mentioned basis. Their physical matrix elements between static B_s-mesons
are extracted from lattice correlators with Schroedinger functional boundary
conditions. We observe a suppression of excited state contributions to the
B_{B_s} mixing parameter and speculate about possible explanations.


title: The Outer Cut-Off of the Giant Planet Population and the 6pc-Survey

abstract:
  We present results from two high-contrast imaging surveys that exploit a
novel technique, L-band angular differential imaging. Our first survey targeted
21 young stars in the Beta Pic and Tuc-Hor moving groups with VLT/NACO reaching
typical sensitivities of <1 MJup at r > 20 AU. The statistical analysis of the
null result demonstrates that the giant planet population is truncated at 30 AU
or less (90% confidence level). Our second, on-going MMT/Clio survey utilizes
the unique sensitivity achieved in the L-band for old planets to probe all
M-dwarf stars within 6 pc. The proximity of these targets enables direct
imaging of planets in orbits like Jupiter for the first time - a key step for
directly imaging giant planets.


title:
Individual complex Dirac eigenvalue distributions from random matrix
  theory and comparison to quenched lattice QCD with a quark chemical potential

abstract:
  We analyze how individual eigenvalues of the QCD Dirac operator at nonzero
quark chemical potential are distributed in the complex plane. Exact and
approximate analytical results for both quenched and unquenched distributions
are derived from non-Hermitian random matrix theory. When comparing these to
quenched lattice QCD spectra close to the origin, excellent agreement is found
for zero and nonzero topology at several values of the quark chemical
potential. Our analytical results are also applicable to other physical systems
in the same symmetry class.


title:
Intersubband spin-orbit coupling and spin splitting in symmetric quantum
  wells

abstract:
  In semiconductors with inversion asymmetry, spin-orbit coupling gives rise to
the well-known Dresselhaus and Rashba effects. If one considers quantum wells
with two or more conduction subbands, an additional, intersubband-induced
spin-orbit term appears whose strength is comparable to the Rashba coupling,
and which remains finite for symmetric structures. We show that the conduction
band spin splitting due to this intersubband spin-orbit coupling term is
negligible for typical III-V quantum wells.


title: QED in arbitrary linear media: amplifying media

abstract:
  Recently, we have developed a unified approach to QED in arbitrary linearly
responding media in equilibrium--media that give rise to absorption [Phys. Rev.
A \textbf{75}, (2007) 053813]. In the present paper we show that, under
appropriate conditions, the theory can be quite naturally generalized to
amplifying media the effect of which is described within the framework of
linear response theory. We discuss the limits of validity of the generalized
theory and make contact with earlier quantization schemes suggested for the
case of linearly and locally responding amplifying dielectric-type media. To
illustrate the theory, we present the electromagnetic-field correlation
functions that determine the Casimir force in the presence of amplifying media.


title: Maximally multipartite entangled states

abstract:
  We introduce the notion of maximally multipartite entangled states of n
qubits as a generalization of the bipartite case. These pure states have a
bipartite entanglement that does not depend on the bipartition and is maximal
for all possible bipartitions. They are solutions of a minimization problem.
Examples for small n are investigated, both analytically and numerically.


title: Canonical extensions of local systems

abstract:
  A local system H on a complex manifold M can be viewed in two ways--either as
a locally free sheaf, or as a union of covering spaces T = T(H). When M is an
open set in a bigger manifold, the local system will generally not extend,
because of local monodromy. This paper proposes an extension of the local
system as an analytic space, in the case when the complement of M has normal
crossing singularities, and the local system is unipotent along the boundary
divisor. The analytic space is obtained by taking the closure of T inside the
total space of Deligne's canonical extension of the associated vector bundle.
It is not normal, but its normalization is locally toric.


title: On the "pits effect" of Littlewood and Offord

abstract:
  Suppose that the moduli of the coefficients of a power series are 1/n!, while
the arguments are arbitrary. If an entire function f represented by such power
series decreases exponentially on some ray, then it has to be an exponential.
If the arguments of the coefficients are of the form 2pi n^2a, where a is
irrational, then the function displays the so-called "pits effect". More
precisely, under this condition, f is of completely regular growth with
constant indicator.


title:
High-Efficiency Resonant RF Spin Rotator with Broad Phase Space
  Acceptance for Pulsed Polarized Cold Neutron Beams

abstract:
  We have developed a radio-frequency resonant spin rotator to reverse the
neutron polarization in a 9.5 cm x 9.5 cm pulsed cold neutron beam with high
efficiency over a broad cold neutron energy range. The effect of the spin
reversal by the rotator on the neutron beam phase space is compared
qualitatively to RF neutron spin flippers based on adiabatic fast passage. The
spin rotator does not change the kinetic energy of the neutrons and leaves the
neutron beam phase space unchanged to high precision. We discuss the design of
the spin rotator and describe two types of transmission-based neutron spin-flip
efficiency measurements where the neutron beam was both polarized and analyzed
by optically-polarized 3He neutron spin filters. The efficiency of the spin
rotator was measured to be 98.0+/-0.8% on resonance for neutron energies from
3.3 to 18.4 meV over the full phase space of the beam. As an example of the
application of this device to an experiment we describe the integration of the
RF spin rotator into an apparatus to search for the small parity-violating
asymmetry A_gamma in polarized cold neutron capture on para-hydrogen by the
NPDGamma collaboration at LANSCE.


title: Geometrical constraints on dark energy models

abstract:
  This contribution intends to give a pedagogical introduction to the topic of
dark energy (the mysterious agent supposed to drive the observed late time
acceleration of the Universe) and to various observational tests which require
only assumptions on the geometry of the Universe. Those tests are the
supernovae luminosity, the CMB shift, the direct Hubble data, and the baryon
acoustic oscillations test. An historical overview of Cosmology is followed by
some generalities on FRW spacetimes (the best large-scale description of the
Universe), and then the test themselves are discussed. A convenient section on
statistical inference is included as well.


title:
Sensitive multiplex spectroscopy in the molecular fingerprint 2.4 $\mu$m
  region with a Cr^{2+}:ZnSe femtosecond laser

abstract:
  An ultrashort-pulse Cr^{2+}:ZnSe laser is a novel broadband source for
sensitive high resolution molecular spectroscopy. A 130-fs pulse allows
covering of up to 380 cm^-1 spectral domain around 2.4 $\mu$m which is analyzed
simultaneously with a 0.12 cm^-1 (3.6 GHz) resolution by a Fourier-transform
spectrometer. Recorded in 13 s, from 70-cm length absorption around 4150 cm^-1,
acetylene and ammonia spectra exhibit a 3800 signal-to-noise ratio and a
2.4*10^-7 cm^-1*Hz^-1/2 noise equivalent absorption coefficient at one second
averaging per spectral element, suggesting a 0.2 ppbv detection level for HF
molecule. With the widely practiced classical tungsten lamp source instead of
the laser, identical spectra would have taken more than one hour.


title:
Infrared frequency combs and supercontinua for multiplex high
  sensitivity spectroscopy

abstract:
  An infrared high-brightness light source based on supercontinuum generation
through a SF6 photonic crystal fiber seeded by a Cr^4+:YAG femtosecond
oscillator is developed for high resolution multiplex spectroscopy in the 1.5
$\mu$m region. Moreover, a multiplex high resolution approach based on a
Cr^4+:YAG frequency comb enables to probe large spectral domains, with
simultaneous sensitive measurement of the absorption and the dispersion
associated with all individual spectral features.


title:
What are the benefits of bound (protonation) states for the
  electron-transfer kinetics?

abstract:
  We describe a model of electron transfer reactions affected by local binding
to the donor or acceptor sites of a particle in equilibrium with the solution.
The statistics of fluctuations of the donor-acceptor energy gap caused by
binding/unbinding events are non-Gaussian, and the resulting free energy
surfaces of electron transfer are non-parabolic. The band-width of the
charge-transfer optical transition is predicted to pass through a maximum as a
function of the concentration of binding particles in the solution. The model
is used to rationalize recent observations of pH-dependence of electron
transfer rates involving changes in the protonation state of the donor-acceptor
complex.


title: Information, Inflation, and Interest

abstract:
  We propose a class of discrete-time stochastic models for the pricing of
inflation-linked assets. The paper begins with an axiomatic scheme for asset
pricing and interest rate theory in a discrete-time setting. The first axiom
introduces a "risk-free" asset, and the second axiom determines the
intertemporal pricing relations that hold for dividend-paying assets. The
nominal and real pricing kernels, in terms of which the price index can be
expressed, are then modelled by introducing a Sidrauski-type utility function
depending on (a) the aggregate rate of consumption, and (b) the aggregate rate
of real liquidity benefit conferred by the money supply. Consumption and money
supply policies are chosen such that the expected joint utility obtained over a
specified time horizon is maximised subject to a budget constraint that takes
into account the "value" of the liquidity benefit associated with the money
supply. For any choice of the bivariate utility function, the resulting model
determines a relation between the rate of consumption, the price level, and the
money supply. The model also produces explicit expressions for the real and
nominal pricing kernels, and hence establishes a basis for the valuation of
inflation-linked securities.


title: Differential isospin-fractionation in dilute asymmetric nuclear matter

abstract:
  The differential isospin-fractionation (IsoF) during the liquid-gas phase
transition in dilute asymmetric nuclear matter is studied as a function of
nucleon momentum. Within a self-consistent thermal model it is shown that the
neutron/proton ratio of the gas phase becomes {\it smaller} than that of the
liquid phase for energetic nucleons, although the gas phase is overall more
neutron-rich. Clear indications of the differential IsoF consistent with the
thermal model predictions are demonstrated within a transport model for
heavy-ion reactions. Future comparisons with experimental data will allow us to
extract critical information about the momentum dependence of the isovector
strong interaction.


title: Hydrogen Adsorption of Back Side of Graphene

abstract:
  We studied the interaction between a single hydrogen atom and a single
graphene using classical molecular dynamics simulation with modified Brenner
REBO potential. Three interactions, which are adsorption, reflection,
penetration, were observed. Overhang structure appears and creates an
adsorption site on the backside of the graphene. It is considered that backside
adsorption occurs under the two conditions that an incident hydrogen atom
should have incident energy which is larger than the potential barrier of a
hexagonal hole of the graphene and that after the hydrogen atom passes through
the graphene, it does not keep its kinetic energy to be trapped by the
adsorption site. The conditions explained that as the incident energy
increased, the incident point of the backside adsorption shifted to the
periphery of a hexagonal hole of the graphene in the simulation. Moreover, when
a hexagonal hole of the graphene was expanded by the hydrogen atom incidence to
the periphery of the hexagonal hole, its potential barrier was reduced.


title: The Richness and Beauty of the Physics of Cosmological Recombination

abstract:
  The physical ingredients to describe the epoch of cosmological recombination
are amazingly simple and well-understood. This fact allows us to take into
account a very large variety of processes, still finding potentially measurable
consequences. In this contribution we highlight some of the detailed physics
that were recently studied in connection with cosmological hydrogen
recombination. The impact of these considerations is two-fold: (i) the
associated release of photons during this epoch leads to interesting and unique
deviations of the Cosmic Microwave Background (CMB) energy spectrum from a
perfect blackbody, which, in particular at decimeter wavelength, may become
observable in the near future. Observing these distortions, in principle would
provide an additional way to determine some of the key parameters of the
Universe (e.g. the specific entropy, the CMB monopole temperature and the
pre-stellar abundance of helium), not suffering from limitations set by cosmic
variance. Also it permits us to confront our detailed understanding of the
recombination process with direct observational evidence. In this contribution
we illustrate how the theoretical spectral template for the cosmological
recombination spectrum may be utilized for this purpose. (ii) with the advent
of high precision CMB data, e.g. as will be available using the Planck Surveyor
or Cmbpol, a very accurate theoretical understanding of the ionization history
of the Universe becomes necessary for the interpretation of the CMB temperature
and polarization anisotropies. (abridged)


title:
A determination of the B_s^0 and B_d^0 mixing parameters in 2+1 lattice
  QCD

abstract:
  We report on the advances in our unquenched calculation of the matrix
elements relevant for the analysis of B^0-\bar B^0 mixing using the Asqtad
(light quark) and Fermilab (heavy quark) actions. We have calculated the
hadronic parameters for the mass and width differences in the neutral B meson
system. Preliminary results are presented for f_{B_q}^2 B_q as well as for the
ratio \xi^2=f_{B_s}^2 B_{B_s}/f_{B_d}^2 B_{B_d}.


title: On the Geometry of Supersymmetric Quantum Mechanical Systems

abstract:
  We consider some simple examples of supersymmetric quantum mechanical systems
and explore their possible geometric interpretation with the help of geometric
aspects of real Clifford algebras. This leads to natural extensions of the
considered systems to higher dimensions and more complicated potentials.


title:
The Initial Mass Function of the Massive Star-forming Region NGC 3603
  from Near-Infrared Adaptive Optics observations

abstract:
  We study the initial mass function (IMF) of one of the most massive Galactic
star-forming regions NGC 3603 to answer a fundamental question in current
astrophysics: is the IMF universal, or does it vary? Using our very deep, high
angular resolution JHKsL' images obtained with NAOS-CONICA at the VLT at ESO,
we have successfully revealed the stellar population down to the subsolar mass
range in the core of the starburst cluster. The derived IMF of NGC 3603 is
reasonably fitted by a single power law with index Gamma ~ -0.74 within a mass
range of 0.4 - 20 Msun, substantially flatter than the Salpeter-like IMF. A
strong radial steepening of the IMF is observed mainly in the inner r < 30''
field, indicating mass segregation in the cluster center. We estimate the total
mass of NGC 3603 to be about 1.0 - 1.6 x 10^4 Msun. The derived core density is
> 6 x 10^4 Msun pc^-3, an order of magnitude larger than e.g., the Orion Nebula
Cluster. The estimate of the half-mass relaxation time for solar-mass stars is
about 10 - 40 Myr, suggesting that the intermediate- and low-mass stars have
not yet been affected significantly by the dynamical relaxation in the cluster.
The relaxation time for the high-mass stars can be comparable to the age of the
cluster. We estimate that the stars residing outside the observed field cannot
steepen the IMF significantly, indicating our IMF adequately describes the
whole cluster. Analyzing thoroughly the systematic uncertainties in our IMF
determination, we conclude that the power law index of the IMF of NGC 3603 is
Gamma = -0.74^{+0.62}_{-0.47}. Our result thus supports the hypothesis of a
potential top-heavy IMF in massive star-forming clusters and starbursts.


title: What rare K decays can tell about the MSSM

abstract:
  The supersymmetric contributions to the theoretically clean K+ --> pi+ nu nu
bar, KL --> pi0 nu nu bar, KL --> pi0 e+ e- and KL --> pi0 mu+ mu- decays are
briefly reviewed. Particular emphasis is laid on the information one could get
on the MSSM flavor sector from a combined study of the four modes.


title: The Urysohn sphere is oscillation stable

abstract:
  We solve the oscillation stability problem for the Urysohn sphere, an analog
of the distortion problem for the Hilbert space in the context of the Urysohn
universal metric space. This is achieved by solving a purely combinatorial
problem involving a family of countable homogeneous metric spaces with finitely
many distances.


title:
Partition properties of the dense local order and a colored version of
  Milliken's theorem

abstract:
  We study the finite dimensional partition properties of the countable
homogeneous dense local order. Some of our results use ideas borrowed from the
partition calculus of the rationals and are obtained thanks to a strengthening
of Milliken's theorem on trees.


title:
$\kappa$-Minkowski space, scalar field, and the issue of Lorentz
  invariance

abstract:
  We describe $\kappa$-Minkowski space and its relation to group theory. The
group theoretical picture makes it possible to analyze the symmetries of this
space. As an application of this analysis we analyze in detail free field
theory on $\kappa$-Minkowski space and the Noether charges associated with
deformed spacetime symmetries.


title:
Implementation, Compilation, Optimization of Object-Oriented Languages,
  Programs and Systems - Report on the Workshop ICOOOLPS'2006 at ECOOP'06

abstract:
  ICOOOLPS'2006 was the first edition of ECOOP-ICOOOLPS workshop. It intended
to bring researchers and practitioners both from academia and industry
together, with a spirit of openness, to try and identify and begin to address
the numerous and very varied issues of optimization. This succeeded, as can be
seen from the papers, the attendance and the liveliness of the discussions that
took place during and after the workshop, not to mention a few new cooperations
or postdoctoral contracts. The 22 talented people from different groups who
participated were unanimous to appreciate this first edition and recommend that
ICOOOLPS be continued next year. A community is thus beginning to form, and
should be reinforced by a second edition next year, with all the improvements
this first edition made emerge.


title:
Pair-distribution functions of two-temperature two-mass systems:
  Comparison of MD, HNC, CHNC, QMC and Kohn-Sham calculations for dense
  hydrogen

abstract:
  Two-temperature, two-mass quasi-equilibrium plasmas may occur in electron-ion
plasmas,nuclear-matter, as well as in electron-hole condensed-matter systems.
Dense two-temperature hydrogen plasmas straddle the difficult partially -
degenerate regime of electron densities and temperatures which are important in
astrophysics, in inertial-confinement fusion research, and other areas of warm
dense matter physics. Results from Kohn-Sham calculations and QMC are used to
benchmark the procedures used in classical molecular-dynamics simulations, HNC
and CHNC methods to derive electron-electron and electron-proton pair -
distribution functions. Then, nonequilibrium molecular dynamics for two
-temperature, two-mass plasmas are used to obtain the pair distribution. Using
these results, the correct HNC and CHNC procedures for the evaluation of
pair-distribution functions in two-temperature two-mass two-component charged
fluids are established. Results for a mass ratio of 1:5, typical of
electron-hole fluids, as well as for compressed hydrogen are presented. PACS
Numbers: 52.25.Kn, 52.25Gj, 71.10.-w, 52.27.Gr, 26.30.+k

categories: cond-mat.stat-mech astro-ph cond-mat.str-el physics.plasm-ph


title: An efficient reduction of ranking to classification

abstract:
  This paper describes an efficient reduction of the learning problem of
ranking to binary classification. The reduction guarantees an average pairwise
misranking regret of at most that of the binary classifier regret, improving a
recent result of Balcan et al which only guarantees a factor of 2. Moreover,
our reduction applies to a broader class of ranking loss functions, admits a
simpler proof, and the expected running time complexity of our algorithm in
terms of number of calls to a classifier or preference function is improved
from $\Omega(n^2)$ to $O(n \log n)$. In addition, when the top $k$ ranked
elements only are required ($k \ll n$), as in many applications in information
extraction or search engines, the time complexity of our algorithm can be
further reduced to $O(k \log k + n)$. Our reduction and algorithm are thus
practical for realistic applications where the number of points to rank exceeds
several thousands. Much of our results also extend beyond the bipartite case
previously studied.
  Our rediction is a randomized one. To complement our result, we also derive
lower bounds on any deterministic reduction from binary (preference)
classification to ranking, implying that our use of a randomized reduction is
essentially necessary for the guarantees we provide.


title:
Model for a collimated spin wave beam generated by a single layer, spin
  torque nanocontact

abstract:
  A model of spin torque induced magnetization dynamics based upon
semi-classical spin diffusion theory for a single layer nanocontact is
presented. The model incorporates effects due to the current induced Oersted
field and predicts the generation of a variety of spatially dependent,
coherent, precessional magnetic wave structures. Directionally controllable
collimated spin wave beams, vortex spiral waves, and localized standing waves
are found to be excited by the interplay of the Oersted field and the
orientation of an applied field. These fields act as a spin wave ``corral''
around the nanocontact that controls the propagation of spin waves in certain
directions.


title: SUSY Model Building

abstract:
  I review some of the latest directions in supersymmetric model building,
focusing on SUSY breaking mechanisms in the minimal supersymmetric standard
model [MSSM], the "little" hierarchy and $\mu$ problems, etc. I then discuss
SUSY GUTs and UV completions in string theory.


title: On the Diversity of the Taurus Transitional Disks: UX Tau A & Lk Ca 15

abstract:
  The recently recognized class of "transitional disk" systems consists of
young starswith optically-thick outer disks but inner disks which are mostly
devoid of small dust. Here we introduce a further class of "pre-transitional
disks" with significant near-infrared excesses which indicate the presence of
an optically thick inner disk separated from an optically thick outer disk;
thus, the spectral energy distributions of pre-transitional disks suggest the
incipient development of disk gaps rather than inner holes. In UX Tau A, our
analysis of the Spitzer IRS spectrum finds that the near-infrared excess is
produced by an inner optically thick disk and a gap of ~56 AU is present. The
Spitzer IRS spectrum of LkCa 15 is suggestive of a gap of ~46 AU, confirming
previous millimeter imaging. In addition, UX Tau A contains crystalline
silicates in its disk at radii >~ 56 AU which poses a challenge to our
understanding of the production of this crystalline material. In contrast, LkCa
15's silicates are amorphous and pristine. UX Tau A and LkCa 15 increase our
knowledge of the diversity of dust clearing in low-mass star formation.


title: On solutions of Rashevskii equation

abstract:
  The solutions of Rashevskii equation for gonometric family of plane curves
are considered. Their properties are studied. The connection with the theory of
duality for the second order ODE's is discussed.


title: HAT-P-6b: A Hot Jupiter transiting a bright F star

abstract:
  In the ongoing HATNet survey we have detected a giant planet, with radius
1.33 +/- 0.06 RJup and mass 1.06 +/- 0.12 MJup, transiting the bright (V =
10.5) star GSC 03239-00992. The planet is in a circular orbit with period
3.852985 +/- 0.000005 days and mid-transit epoch 2,454,035.67575 +/- 0.00028
(HJD). The parent star is a late F star with mass 1.29 +/- 0.06 Msun, radius
1.46 +/- 0.06 Rsun, Teff ~ 6570 +/- 80 K, [Fe=H] = -0.13 +/- 0.08 and age ~
2.3+/-^{0.5}_{0.7}Gy. With this radius and mass, HAT-P-6b has somewhat larger
radius than theoretically expected. We describe the observations and their
analysis to determine physical properties of the HAT-P-6 system, and briefly
discuss some implications of this finding.


title: Quaternionic Analysis and the Algebrodynamics

abstract:
  We present the ``algebrodynamical'' approach to field-particle theory based
on a nonlinear generalization of the Cauchy-Riemann conditions to
non-commutative algebras of quaternion-like type. For complex quaternions the
theory is Lorentz invariant and naturally carries some gauge and twistor
structures. Point- and string-like singularities are considered as
particle-like formations; their electric charge is ``self-quantized''. A novel
``causal Minkowski geometry with additional phase'' is presented that is
induced by the structure of primordial biquaternion algebra. On this
geometrical background a self-consistent algebraic dynamics of singularities
(``ensemble of dublicons'') is briefly discussed.


title:
EasyNData: A simple tool to extract numerical values from published
  plots

abstract:
  The comparison of numerical data with published plots is a frequently
occurring task. In this article I present a short computer program written in
Java(TM) helping in those cases where someone wants to get the numbers out of a
plot but is not able to read the plot with a decent accuracy and cannot contact
the author of the plot directly for whatever reason. The accuracy reached by
this method depends on many factors. For the examples illustrated in this paper
a precision at the level of a few per mille could be reached. The tool might
help in improving the quality of future publications.


title: Searches for Squarks and Gluinos with D0 Detector

abstract:
  Searches for supersymmetry in the framework of R-parity conserving models
have been performed in data collected by the D0 detector at the Tevatron
$p\bar{p}$ collider at a center-of-mass energy of 1.96 TeV. Topologies analyzed
consist of acoplanar-jets, multijets, and leptons with large missing transverse
energy in the final state. The 1 fb$^{-1}$ data shows good agreement with the
standard model expectations. The improved mass limits at 95% CL have been
derived. In the first search, generic squarks and gluinos productions are
investigated and lower limits of 375 GeV and 289 GeV are derived on the squarks
and gluino masses, respectively, with $\tan$($\beta$) = 3, $A_0$ = 0 and $\mu
<$ 0. In second analysis, squarks are searched for in a final state that has
$\tau$ leptons accompanied by jets and missing transverse energy. This channel
is explored for the first time at the Tevatron and excludes squark masses $<$
366 GeV. Supergravity inspired models suggest the existence of light
supersymmetric partners of the third generation quarks: a light stop for
moderate values of $\tan(\beta)$, a light sbottom for large $\tan(\beta)$. If
stop is the next-to-lightest supersymmetric particle, the expected decay
channel is $\tilde{t} \to c \tilde{\chi}^0_1$ with $\tilde{\chi}^0_1$ assumed
to be the lightest supersymmetric particle. Using this channel, stop masses $<$
149 GeV and neutralino masses $<$ 63 GeV are excluded. If there is a mass
hierarchy between stop, chargino and sneutrino masses, stop is expected to
decay via $\tilde{t} \to b l \tilde{\nu}$ where $l$ could be an electron or
muon. The search performed with both electrons, muons and dimuon final states
excludes stop mass $<$ 186 GeV for sneutrino mass of 71 GeV.


title:
Higher rank numerical ranges and low rank perturbations of quantum
  channels

abstract:
  For a positive integer $k$, the rank-$k$ numerical range $\Lambda_k(A)$ of an
operator $A$ acting on a Hilbert space $\cH$ of dimension at least $k$ is the
set of scalars $\lambda$ such that $PAP = \lambda P$ for some rank $k$
orthogonal projection $P$. In this paper, a close connection between low rank
perturbation of an operator $A$ and $\Lambda_k(A)$ is established. In
particular, for $1 \le r < k$ it is shown that $\Lambda_k(A) \subseteq
\Lambda_{k-r}(A+F)$ for any operator $F$ with $\rank (F) \le r$. In quantum
computing, this result implies that a quantum channel with a $k$-dimensional
error correcting code under a perturbation of rank $\le r$ will still have a
$(k-r)$-dimensional error correcting code. Moreover, it is shown that if $A$ is
normal or if the dimension of $A$ is finite, then $\Lambda_k(A)$ can be
obtained as the intersection of $\Lambda_{k-r}(A+F)$ for a collection of rank
$r$ operators $F$. Examples are given to show that the result fails if $A$ is a
general operator. The closure and the interior of the convex set $\Lambda_k(A)$
are completely determined. Analogous results are obtained for
$\Lambda_\infty(A)$ defined as the set of scalars $\lambda$ such that $PAP =
\lambda P$ for an infinite rank orthogonal projection $P$. It is shown that
$\Lambda_\infty(A)$ is the intersection of all $\Lambda_k(A)$ for $k = 1, 2,
>...$. If $A - \mu I$ is not compact for any $\mu \in \IC$, then the closure
and the interior of $\Lambda_\infty(A)$ coincide with those of the essential
numerical range of $A$. The situation for the special case when $A-\mu I$ is
compact for some $\mu \in \IC$ is also studied.


title:
Discovery of 21cm absorption in a $z_{\rm abs} =2.289$ DLA towards TXS
  0311+430: The first low spin temperature absorber at z > 1

abstract:
  We report the detection of HI 21 cm absorption from the $z=2.289$ damped
Lyman-$\alpha$ system (DLA) towards TXS 0311+430, with the Green Bank
Telescope. The 21 cm absorption has a velocity spread (between nulls) of $\sim
110$ km s$^{-1}$ and an integrated optical depth of $\int \tau {\rm d}V =
(0.818 \pm 0.085)$ km s$^{-1}$. We also present new Giant Metrewave Radio
Telescope 602 MHz imaging of the radio continuum. TXS 0311+430 is unresolved at
this frequency, indicating that the covering factor of the DLA is likely to be
high. Combining the integrated optical depth with the DLA HI column density of
\nhi = $(2 \pm 0.5) \times 10^{20}$ \cm, yields a spin temperature of $T_s =
(138 \pm 36)$ K, assuming a covering factor of unity. This is the first case of
a low spin temperature ($< 350$ K) in a $z > 1$ DLA and is among the lowest
ever measured in any DLA. Indeed, the $T_s$ measured for this DLA is similar to
values measured in the Milky Way and local disk galaxies. We also determine a
lower limit (Si/H) $\gtrsim 1/3$ solar for the DLA metallicity, amongst the
highest abundances measured in DLAs at any redshift. Based on low redshift
correlations, the low $T_s$, large 21 cm absorption width and high metallicity
all suggest that the $z \sim 2.289$ DLA is likely to arise in a massive,
luminous disk galaxy.


title:
In Search of Possible Associations between Planetary Nebulae and Open
  Clusters

abstract:
  We consider the possibility of cluster membership for 13 planetary nebulae
that are located in close proximity to open clusters lying in their lines of
sight. The short lifetimes and low sample size of intermediate-mass planetary
nebulae with respect to nearby open clusters conspire to reduce the probability
of observing a true association. Not surprisingly, line of sight coincidences
almost certainly exist for 7 of the 13 cases considered. Additional studies are
advocated, however, for 6 planetary nebula/open cluster coincidences in which a
physical association is not excluded by the available evidence, namely M
1-80/Berkeley 57, NGC 2438/NGC 2437, NGC 2452/NGC 2453, VBRC 2 & NGC 2899/IC
2488, and HeFa 1/NGC 6067. A number of additional potential associations
between planetary nebulae and open clusters is tabulated for reference
purposes. It is noteworthy that the strongest cases involve planetary nebulae
lying in cluster coronae, a feature also found for short-period cluster
Cepheids, which are themselves potential progenitors of planetary nebulae.


title:
Bulges versus disks: the evolution of angular momentum in cosmological
  simulations of galaxy formation

abstract:
  We investigate the evolution of angular momentum in simulations of galaxy
formation in a cold dark matter universe. We analyse two model galaxies
generated in the N-body/hydrodynamic simulations of Okamoto et al. Starting
from identical initial conditions, but using different assumptions for the
baryonic physics, one of the simulations produced a bulge-dominated galaxy and
the other one a disc-dominated galaxy. The main difference is the treatment of
star formation and feedback, both of which were designed to be more efficient
in the disc-dominated object. We find that the specific angular momentum of the
disc-dominated galaxy tracks the evolution of the angular momentum of the dark
matter halo very closely: the angular momentum grows as predicted by linear
theory until the epoch of maximum expansion and remains constant thereafter. By
contrast, the evolution of the angular momentum of the bulge-dominated galaxy
resembles that of the central, most bound halo material: it also grows at first
according to linear theory, but 90% of it is rapidly lost as pre-galactic
fragments, into which gas had cooled efficiently, merge, transferring their
orbital angular momentum to the outer halo by tidal effects. The disc-dominated
galaxy avoids this fate because the strong feedback reheats the gas which
accumulates in an extended hot reservoir and only begins to cool once the
merging activity has subsided. Our analysis lends strong support to the
classical theory of disc formation whereby tidally torqued gas is accreted into
the centre of the halo conserving its angular momentum.


title:
A Half-Megasecond Chandra Observation of the Oxygen-Rich Supernova
  Remnant G292.0+1.8

abstract:
  We report on our initial analysis of a deep 510 ks observation of the
Galactic oxygen-rich supernova remnant (SNR) G292.0+1.8 with the {\it Chandra
X-ray Observatory}. Our new {\it Chandra} ACIS-I observation has a larger field
of view and an order of magnitude deeper exposure than the previous {\it
Chandra} observation, which allows us to cover the entire SNR and to detect new
metal-rich ejecta features. We find a highly non-uniform distribution of
thermodynamic conditions of the X-ray emitting hot gas that correlates well
with the optical [O {\small III}] emission, suggesting the possibility that the
originating supernova explosion of G292.0+1.8 was itself asymmetric. We also
reveal spectacular substructures of a torus, a jet, and an extended central
compact nebula all associated with the embedded pulsar J1124$-$5916.


title: Non-LTE dust nucleation in sub-saturated vapors

abstract:
  We use the kinetic theory of nucleation to explore the properties of dust
nucleation in sub-saturated vapors. Due to radiation losses, the sub-critical
clusters have a smaller temperature compared to their vapor. This alters the
dynamical balance between attachment and detachment of monomers, allowing for
stable nucleation of grains in vapors that are sub-saturated for their
temperature. We find this effect particularly important at low densities and in
the absence of a strong background radiation field. We find new conditions for
stable nucleation in the n-T phase diagram. The nucleation in the non-LTE
regions is likely to be at much slower rate than in the super-saturated vapors.
We evaluate the nucleation rate, warning the reader that it does depend on
poorly substantiated properties of the macro-molecules assumed in the
computation. On the other hand, the conditions for nucleation depend only on
the properties of the large stable grains and are more robust. We finally point
out that this mechanism may be relevant in the early universe as an initial
dust pollution mechanism, since once the interstellar medium is polluted with
dust, mantle growth is likely to be dominant over non-LTE nucleation in the
diffuse medium.


title: Planets Around Massive Subgiants

abstract:
  Compared to planets around Sun-like stars, relatively little is known about
the occurrence rate and orbital properties of planets around stars more massive
than 1.3 Msun. The apparent deficit of planets around massive stars is due to a
strong selection bias against early-type dwarfs in Doppler-based planet
searches. One method to circumvent the difficulties inherent to massive
main-sequence stars is to instead observe them after they have evolved onto the
subgiant branch. We show how the cooler atmospheres and slower rotation
velocities of subgiants make them ideal proxies for F- and A-type stars. We
present the early results from our planet search that reveal a paucity of
planets orbiting within 1 AU of stars more massive than 1.5 Msun, and evidence
of a rising trend in giant planet occurrence with stellar mass.


title:
Chiral Random Two-Matrix Theory and QCD with imaginary chemical
  potential

abstract:
  We summarise recent results for the chiral Random Two-Matrix Theory
constructed to describe QCD in the epsilon-regime with imaginary chemical
potential. The virtue of this theory is that unquenched Lattice simulations can
be used to determine both low energy constants Sigma and F in the leading order
chiral Lagrangian, due to their respective coupling to quark mass and chemical
potential. We briefly recall the analytic formulas for all density and
individual eigenvalue correlations and then illustrate them in detail in the
simplest, quenched case with imaginary isospin chemical potential. Some
peculiarities are pointed out for this example: i) the factorisation of density
and individual eigenvalue correlation functions for large chemical potential
and ii) the factorisation of the non-Gaussian weight function of bi-orthogonal
polynomials into Gaussian weights with ordinary orthogonal polynomials.


title:
The gl(1|1) super-current algebra: the role of twist and logarithmic
  fields

abstract:
  A free field representation of the gl(1|1)_k current algebra at arbitrary
level k is given in terms of two scalar fields and a symplectic fermion. The
primary fields for all representations are explicitly constructed using the
twist and logarithmic fields in the symplectic fermion sector. A closed
operator algebra is described at integer level k. Using a new super spin charge
separation involving gl(1|1)_N and su(N)_0, we describe how the gl(1|1)_N
current algebra can describe a non-trivial critical point of disordered Dirac
fermions. Local gl(1|1) invariant lagrangians are defined which generalize the
Liouville and sine-Gordon theories. We apply these new tools to the spin
quantum Hall transition and show that it can be described as a logarithmic
perturbation of the osp(2|2)_k current algebra at k=-2.


title:
Renormalization group approach to 2D Coulomb interacting Dirac fermions
  with random gauge potential

abstract:
  We argue that massless Dirac particles in two spatial dimensions with $1/r$
Coulomb repulsion and quenched random gauge field are described by a manifold
of fixed points which can be accessed perturbatively in disorder and
interaction strength, thereby confirming and extending the results of
arXiv:0707.4171. At small interaction and small randomness, there is an
infra-red stable fixed curve which merges with the strongly interacting
infra-red unstable line at a critical endpoint, along which the dynamical
critical exponent $z=1$.


title: A tour of theta dualities on moduli spaces of sheaves

abstract:
  The purpose of this paper is twofold. First, we survey known results about
theta dualities on moduli spaces of sheaves on curves and surfaces. Secondly,
we establish new such dualities in the surface case. Among others, the case of
elliptic K3 surfaces is studied in detail; we propose further conjectures which
are shown to imply strange duality.


title:
Signal and Charge Transfer Efficiency of Few Electrons Clocked on
  Microscopic Superfluid Helium Channels

abstract:
  Electrons floating on the surface of liquid helium are possible spin-qubits
for quantum information processing. Varying electric potentials are not
expected to modify spin states, which allows their transport on helium using a
charge-coupled device (CCD)-like array of underlying gates. This approach
depends upon efficient inter-gate transfer of individual electrons.
Measurements are presented here of the charge transfer efficiency (CTE) of few
electrons clocked back and forth above a short microscopic CCD-like structure.
A charge transfer efficiency of 0.99999992 is obtained for a clocking frequency
of 800 kHz.


title: Generating dark solitons by single photons

abstract:
  We show that dark solitons in 1D bose systems may be excited by resonant
absorption of single quanta of an external ac field. The energy of the quantum
$\hbar\omega$ should be slightly blue-detuned from the energy of a soliton with
momentum $\hbar q$, where $q$ is the external field wavenumber $q$. We
calculate the absorption cross-section and show that it has power-law
dependence on the frequency detuning. This reflects the quantum nature of the
absorption process and the orthogonality catastrophe phenomenon associated with
it.


title: Spectral isolation of bi-invariant metrics on compact Lie groups

abstract:
  We show that a bi-invariant metric on a compact connected Lie group $G$ is
spectrally isolated within the class of left-invariant metrics. In fact, we
prove that given a bi-invariant metric $g_0$ on $G$ there is a positive integer
$N$ such that, within a neighborhood of $g_0$ in the class of left-invariant
metrics of at most the same volume, $g_0$ is uniquely determined by the first
$N$ distinct non-zero eigenvalues of its Laplacian (ignoring multiplicities).
In the case where $G$ is simple, $N$ can be chosen to be two.


title: Updating Probabilities: An Econometric Example

abstract:
  We demonstrate how information in the form of observable data and moment
constraints are introduced into the method of Maximum relative Entropy (ME). A
general example of updating with data and moments is shown. A specific
econometric example is solved in detail which can then be used as a template
for real world problems. A numerical example is compared to a large deviation
solution which illustrates some of the advantages of the ME method.


title: Tight closure does not commute with localization

abstract:
  We give an example showing that tight closure does not commute with
localization.


title: Andreev-like reflections with cold atoms

abstract:
  We propose a setup in which Andreev-like reflections predicted for 1D
transport systems could be observed time-dependently using cold atoms in a 1D
optical lattice. Using time-dependent Density Matrix Renormalisation Group
methods we analyse the wavepacket dynamics as a density excitation propagates
across a boundary in the interaction strength. These phenomena exhibit good
correspondence with predictions from Luttinger liquid models and could be
observed in current experiments in the context of the Bose-Hubbard model.


title: The late-time tails in the Reissner-Nordstr\"{o}m spacetime revisited

abstract:
  We propose that the late-time tail problem in the Reissner-Nordstr\"{o}m (RN)
spacetime is dual to a tail problem in the Schwarzschild spacetime with a
different initial data set: at a fixed observation point the asymptotic decay
rate of the fields are equal. This duality is used to find the decay rate for
tails in RN. This decay rate is exactly as in Schwarzschild, including the case
of the extremely-charged RN spacetime (ERN). The only case where any deviation
from the Schwarzschild decay rate is found is the case of the tails along the
event horizon of an ERN spacetime, where the decay rate is the same as at
future null infinity. As observed at a fixed location, the decay rate in ERN is
the same as in Schwarzschild. We verify these expectations with numerical
simulations.


title: Dissociation and ionization of small molecules steered by external noise

abstract:
  We show that ionization and dissociation can be influenced separately in a
molecule with appropriate external noise. Specifically we investigate the
hydrogen molecular ion under a stochastic force quantum mechanically beyond the
Born-Oppenheimer approximation. We find that up to 30% of dissociation without
ionization can be achieved by suitably tuning the forcing parameters.


title:
Comparison of Boltzmann Kinetics with Quantum Dynamics for a Chiral
  Yukawa Model Far From Equilibrium

abstract:
  Boltzmann equations are often used to describe the non-equilibrium
time-evolution of many-body systems in particle physics. Prominent examples are
the computation of the baryon asymmetry of the universe and the evolution of
the quark-gluon plasma after a relativistic heavy ion collision. However,
Boltzmann equations are only a classical approximation of the quantum
thermalization process, which is described by so-called Kadanoff-Baym
equations. This raises the question how reliable Boltzmann equations are as
approximations to the complete Kadanoff-Baym equations. Therefore, we present
in this article a detailed comparison of Boltzmann and Kadanoff-Baym equations
in the framework of a chirally invariant Yukawa-type quantum field theory
including fermions and scalars. The obtained numerical results reveal
significant differences between both types of equations. Apart from
quantitative differences, on a qualitative level the late-time universality
respected by Kadanoff-Baym equations is severely restricted in the case of
Boltzmann equations. Furthermore, Kadanoff-Baym equations strongly separate the
time scales between kinetic and chemical equilibration. In contrast to this
standard Boltzmann equations cannot describe the process of quantum-chemical
equilibration, and consequently also cannot feature the above separation of
time scales.


title: Twisted Yangians and finite W-algebras

abstract:
  We construct an explicit set of generators for the finite W-algebras
associated to nilpotent matrices in the symplectic or orthogonal Lie algebras
whose Jordan blocks are all of the same size. We use these generators to show
that such finite W-algebras are quotients of twisted Yangians.


title: Phase structure of twisted Eguchi-Kawai model

abstract:
  We study the phase structure of the four-dimensional twisted Eguchi-Kawai
model using numerical simulations. This model is an effective tool for studying
SU(N) gauge theory in the large-N limit and provides a nonperturbative
formulation of the gauge theory on noncommutative spaces. Recently it was found
that its Z_N^4 symmetry, which is crucial for the validity of this model, can
break spontaneously in the intermediate coupling region. We investigate in
detail the symmetry breaking point from the weak coupling side. Our simulation
results show that the continuum limit of this model cannot be taken.


title:
Continuum theory for the piezoelectric response of chiral nanotubes
  under uniaxial and torsional stresses

abstract:
  We develop and solve a continuum theory for the piezoelectric response of
nanotubes under applied uniaxial and torsional stresses. We find that the
piezoelectric response is controlled by the chiral angle, the aspect ratio, and
two dimensionless parameters specifying the ratio of the strengths of the
electrostatic and elastic energies. The model is solved in two limiting cases
and the solutions are discussed. These systems are found to have several
unexpected physical effects not seen in conventional bulk systems, including a
strong stretch-twist coupling and the development of a significant bound charge
density in addition to a surface charge density. The model is applied to
estimate the piezoelectric response of a boron-nitride nanotube under uniform
tensile stress.


title: Shock-Induced Flows through Packed Beds: Transient Regimes

abstract:
  The early stage of the transient regimes in the shock-induced flows within
solid-packed beds are investigated in the linear longwave and high-frequency
approximation. The transient resistance law is refined as the Duhameltime
integral that follows from the general concept of dynamic tortuosity and
compressibility of the packed beds. A closed-form solution is expected to
describe accurately the early stage of the transient regime flow and is in
qualitative agreement with available experimental data.


title:
Experimental demonstration of phase measurement precision beating
  standard quantum limit by projection measurement

abstract:
  We propose and demonstrate experimentally a projection scheme to measure the
quantum phase with a precision beating the standard quantum limit. The initial
input state is a twin Fock state $|N,N>$ proposed by Holland and Burnett [Phys.
Rev. Lett. {\bf 71}, 1355 (1993)] but the phase information is extracted by a
quantum state projection measurement. The phase precision is about $1.4/N$ for
large photon number $N$, which approaches the Heisenberg limit of 1/N.
Experimentally, we employ a four-photon state from type-II parametric
down-conversion and achieve a phase uncertainty of $0.291\pm 0.001$ beating the
standard quantum limit of $1/\sqrt{N} = 1/2$ for four photons.


title: Looking for signals beyond the neutrino Standard Model

abstract:
  Any new neutrino physics at the TeV scale must include a suppression
mechanism to keep its contribution to light neutrino masses small enough. We
review some seesaw model examples with weakly broken lepton number, and comment
on the expected effects at large colliders and in neutrino oscillations.


title: Neutron Polarisabilities from Deuteron Compton Scattering in \chiEFT

abstract:
  Chiral Effective Field Theory is for photon energies up to 200 MeV the tool
to accurately determine the polarisabilities of the neutron from deuteron
Compton scattering. A multipole analysis reveals that dispersive effects from
an explicit Delta(1232) prove in particular indispensable to understand the
data at 95 MeV measured at SAL. Simple power-counting arguments derived from
nuclear phenomenology lead to the correct Thomson limit and gauge invariance.
At next-to-leading order, the static scalar dipole polarisabilities are
extracted as identical for proton and neutron within the error-bar of available
data: \alpha^n=11.6\pm1.5_stat\pm0.6_Baldin,
\beta^n=3.6\mp1.5_stat\pm0.6_Baldin for the neutron, in units of 10^-4 fm^3,
compared to \alpha^p=11.0\pm1.4_stat\pm0.4_Baldin,
\beta}^p=2.8\mp1.4_stat\pm0.4_Baldin for the proton in the same framework. New
experiments e.g. at MAXlab (Lund) will improve the statistical error-bar.


title:
Bridging over p-wave pi-production and weak processes in few-nucleon
  systems with chiral perturbation theory

abstract:
  We focus on a powerful aspect of chiral perturbation theory (chi PT) which
provides us with a ``bridge'' over different reactions. For this purpose, we
study a contact operator which contributes p-wave pi-production and several
weak processes. We fix the unknown coupling of the contact operator using a
matrix element of a low-energy weak process (pp\to de^+\nu_e), and then
calculate the partial wave amplitude (a_0) for the p-wave pi-production (pp\to
pn\pi^+). We find that the chiral operator including the contact term does not
reproduce a_0 extracted from data, showing that the bridging over reactions
with significantly different kinematics is not necessarily successful. We argue
the importance of a specific higher order calculation. In order to gain an
insight into a higher order calculation, we consider a higher order counter
term, and find that the energy dependence of a_0 is then consistent with the
data.


title: Long Baseline Neutrino Experiments with Two-Detector Setup

abstract:
  I discuss why and how powerful is the two-detector setting in neutrino
oscillation experiments. I cover three concrete examples: (1) reactor
\theta_{13} experiments, (2) T2KK, Tokai-to-Kamioka-Korea two-detector complex
for measuring CP violation, determining the neutrino mass hierarchy, and
resolving the eight-fold parameter degeneracy, (3) two-detector setting in a
neutrino factory at baselines 3000 km and 7000 km for detecting effects of
non-standard interactions (NSI) of neutrinos.


title:
Renormalization group analysis of the chiral pion production operator
  for NN\to d\pi

abstract:
  We are interested in the consistency between the cutoff, chiral symmetry, and
the power counting. For this purpose, we apply the Wilsonian renormalization
group (RG) to an operator and then decrease the Wilsonian cutoff. As an
example, we study the s-wave pion production operator for NN\to d\pi, derived
in chiral perturbation theory. We find that the renormalized part of the RG
effective operator is accurately absorbed by chiral counter terms of higher
order with natural coefficients. Thus, the use of the (sharp) cutoff
regularization does not require us to introduce chiral-symmetry-breaking
counter terms, at least in the case of the NN\to d\pi reaction.


title:
Embedding A4 into left-right flavor symmetry: Tribimaximal neutrino
  mixing and fermion hierarchy

abstract:
  We address two fundamental aspects of flavor physics: the mass hierarchy and
the large lepton mixing angles. On one side, left-right flavor symmetry
realizes the democratic mass matrix patterns and explains why one family is
much heavier than the others. On the other side, discrete flavor symmetry such
as A4 leads to the observed tribimaximal mixing for the leptons. We show that,
by explicitly breaking the left-right flavor symmetry into the diagonal A4, it
is possible to explain both the observed charged fermion mass hierarchies and
quark and lepton mixing angles. In particular we predict a heavy 3rd family,
the tribimaximal mixing for the leptons, and we suggest a possible origin of
the Cabibbo and other mixing angles for the quarks.


title:
Quantum Barnes function as the partition function of the resolved
  conifold

abstract:
  We suggest a new strategy for proving large $N$ duality by interpreting
Gromov-Witten, Donaldson-Thomas and Chern-Simons invariants of a Calabi-Yau
threefold as different characterizations of the same holomorphic function. For
the resolved conifold this function turns out to be the quantum Barnes
function, a natural $q$-deformation of the classical one that in its turn
generalizes Euler's gamma function. Our reasoning is based on a new formula for
this function that expresses it as a graded product of $q$-shifted
multifactorials.


title:
Atmospheric Circulation of Hot Jupiters: A Review of Current
  Understanding

abstract:
  Hot Jupiters are new laboratories for the physics of giant planet
atmospheres. Subject to unusual forcing conditions, the circulation regime on
these planets may be unlike anything known in the Solar System. Characterizing
the atmospheric circulation of hot Jupiters is necessary for reliable
interpretation of the multifaceted data currently being collected on these
planets. We discuss several fundamental concepts of atmospheric dynamics that
are likely central to obtaining a solid understanding of these fascinating
atmospheres. A particular effort is made to compare the various modeling
approaches employed so far to address this challenging problem.


title:
Exchange biasing of single-domain Ni nanoparticles spontaneously grown
  in an antiferromagnetic MnO matrix

abstract:
  Exchange biased composites of ferromagnetic single-domain Ni nanoparticles
embedded within large grains of MnO have been prepared by reduction of
Ni$_x$Mn$_{1-x}$O$_4$ phases in flowing hydrogen. The Ni precipitates are 15-30
nm in extent, and the majority are completely encased within the MnO matrix.
The manner in which the Ni nanoparticles are spontaneously formed imparts a
high ferromagnetic- antiferromagnetic interface/volume ratio, which results in
substantial exchange bias effects. Exchange bias fields of up to 100 Oe are
observed, in cases where the starting Ni content $x$ in the precursor
Ni$_x$Mn$_{1-x}$O$_4$ phase is small. For particles of approximately the same
size, the exchange bias leads to significant hardening of the magnetization,
with the coercive field scaling nearly linearly with the exchange bias field.


title: Total positivity for cominuscule Grassmannians

abstract:
  In this paper we explore the combinatorics of the non-negative part (G/P)+ of
a cominuscule Grassmannian. For each such Grassmannian we define Le-diagrams --
certain fillings of generalized Young diagrams which are in bijection with the
cells of (G/P)+. In the classical cases, we describe Le-diagrams explicitly in
terms of pattern avoidance. We also define a game on diagrams, by which one can
reduce an arbitrary diagram to a Le-diagram. We give enumerative results and
relate our Le-diagrams to other combinatorial objects. Surprisingly, the
totally non-negative cells in the open Schubert cell of the odd and even
orthogonal Grassmannians are (essentially) in bijection with preference
functions and atomic preference functions respectively.