title:
Local Luminous Infrared Galaxies. III. Co-evolution of Black Hole Growth
  and Star Formation Activity?

abstract:
  Local luminous infrared (IR) galaxies (LIRGs) have both high star formation
rates (SFR) and a high AGN (Seyfert and AGN/starburst composite) incidence.
Therefore, they are ideal candidates to explore the co-evolution of black hole
(BH) growth and star formation (SF) activity, not necessarily associated with
major mergers. Here, we use Spitzer/IRS spectroscopy of a complete
volume-limited sample of local LIRGs (distances of <78Mpc). We estimate typical
BH masses of 3x10^7 M_sun using [NeIII]15.56micron and optical [OIII]5007A gas
velocity dispersions and literature stellar velocity dispersions. We find that
in a large fraction of local LIRGs the current SFR is taking place not only in
the inner nuclear ~1.5kpc region, as estimated from the nuclear 11.3micron PAH
luminosities, but also in the host galaxy. We next use the ratios between the
SFRs and BH accretion rates (BHAR) to study whether the SF activity and BH
growth are contemporaneous in local LIRGs. On average, local LIRGs have SFR to
BHAR ratios higher than those of optically selected Seyferts of similar AGN
luminosities. However, the majority of the IR-bright galaxies in the RSA
Seyfert sample behave like local LIRGs. Moreover, the AGN incidence tends to be
higher in local LIRGs with the lowest SFRs. All this suggests that in local
LIRGs there is a distinct IR-bright star forming phase taking place prior to
the bulk of the current BH growth (i.e., AGN phase). The latter is reflected
first as a composite and then as a Seyfert, and later as a non-LIRG optically
identified Seyfert nucleus with moderate SF in its host galaxy.


title:
On the Classification of Exceptional Planar Functions over
  $\mathbb{F}_{p}$

abstract:
  We will present many strong partial results towards a classification of
exceptional planar/PN monomial functions on finite fields. The techniques we
use are the Weil bound, Bezout's theorem, and Bertini's theorem.


title: Decomposition Complexes

abstract:
  We introduce decomposition complexes of posets, which generalize order
complexes. The main advantage of our construction is that decomposition
complexes are closed under taking products. Other special instances of this
theory include nested set complexes as well as Bergman complexes.


title:
Impact of substrate on magnetic phase coexistence in bicritical
  $Sm_{0.53} Sr_{0.47} Mn O_3$ thin films

abstract:
  Sm0.53Sr0.47MnO3 thin films were deposited on single crystal LaAlO3
(LAO/(001)) and SrTiO3 (STO/(001)) substrates by DC magnetron sputtering. The
theta-2theta and omega-2theta scans show that these films have very good
crystallinity and the films on LAO and STO are under compressive and tensile
strain, respectively. The films on LAO and STO substrates show ferromagnetic
(insulator-metal) transition at TC \sim 126 K (at TIM \sim 128 K) and 120 K
(TIM \sim 117K), respectively. The magnetic state at T<TC is akin to cluster
glass, which is formed by the presence of charge ordered-antiferromagnetic
clusters in the ferromagnetic matrix. Huge drop in the resistivity at TIM and
the associated hysteresis with respect to cooling and warming cycles reveal the
bicritical and the first order nature of phase transition, which is also
confirmed by the Banerjee criterion. The differences and similarities in the
functional properties of films are explained in terms of substrate modified
magnetic phase coexistence.


title: Parallel resampling in the particle filter

abstract:
  Modern parallel computing devices, such as the graphics processing unit
(GPU), have gained significant traction in scientific and statistical
computing. They are particularly well-suited to data-parallel algorithms such
as the particle filter, or more generally Sequential Monte Carlo (SMC), which
are increasingly used in statistical inference. SMC methods carry a set of
weighted particles through repeated propagation, weighting and resampling
steps. The propagation and weighting steps are straightforward to parallelise,
as they require only independent operations on each particle. The resampling
step is more difficult, as standard schemes require a collective operation,
such as a sum, across particle weights. Focusing on this resampling step, we
analyse two alternative schemes that do not involve a collective operation
(Metropolis and rejection resamplers), and compare them to standard schemes
(multinomial, stratified and systematic resamplers). We find that, in certain
circumstances, the alternative resamplers can perform significantly faster on a
GPU, and to a lesser extent on a CPU, than the standard approaches. Moreover,
in single precision, the standard approaches are numerically biased for upwards
of hundreds of thousands of particles, while the alternatives are not. This is
particularly important given greater single- than double-precision throughput
on modern devices, and the consequent temptation to use single precision with a
greater number of particles. Finally, we provide auxiliary functions useful for
implementation, such as for the permutation of ancestry vectors to enable
in-place propagation.


title:
Invariant Hilbert schemes and desingularizations of quotients by
  classical groups

abstract:
  Let $W$ be a finite-dimensional representation of a reductive algebraic group
$G$. The invariant Hilbert scheme $\mathcal{H}$ is a moduli space that
classifies the $G$-stable closed subschemes $Z$ of $W$ such that the affine
algebra $k[Z]$ is the direct sum of simple $G$-modules with prescribed
multiplicities. In this article, we consider the case where $G$ is a classical
group acting on a classical representation $W$ and $k[Z]$ is isomorphic to the
regular representation of $G$ as a $G$-module. We obtain families of examples
where $\mathcal{H}$ is a smooth variety, and thus for which the Hilbert-Chow
morphism $\gamma: \mathcal{H} \rightarrow W//G$ is a canonical
desingularization of the categorical quotient.


title: Silica-Like Sequence of Anomalies in Core-Softened Systems

abstract:
  In this paper we present a simulation study of density, structural and
diffusion anomalies in core-softened system introduced in our previous
publications. It is well-known, that with appropriate parametrization,
core-softened systems are remarkable model liquids that exhibit anomalous
properties observed in tetrahedral liquids such as silica and water. It is
widely believed that core-softened potentials demonstrate the water-like
sequence of anomalies. We show that with increasing the depth of the attractive
part of the potential the order of the region of anomalous diffusion and the
regions of density and structural anomalies is inverted and have the
silica-like sequence. We also show that the slope of the Widom line is negative
like in water.


title: La conjecture de Tate enti\`ere pour les cubiques de dimension quatre

abstract:
  We prove the Tate conjecture for integral degree 4 classes on a smooth cubic
hypersurface X of dimension 4 over an algebraic closure of a field finitely
generated over its prime subfield.


title:
Wong-Zakai approximation of solutions to reflecting stochastic
  differential equations on domains in Euclidean spaces

abstract:
  In this paper, we study the Wong-Zakai approximation of the solution to the
stochastic differential equation on a domain $D$ in a Euclidean space with
normal reflection at the boundary. We prove the $L^p$ convergence of the
approximation in $C([0,T]\to \bar{D})$ under some general conditions on $D$.


title: Properties of Dust Grains Probed with Extinction Curves

abstract:
  Modern data of the extinction curve from the ultraviolet to the near infrared
are revisited to study the property of dust grains in the Milky Way (MW) and
the Small Magellanic Cloud (SMC). We confirm that the graphite-silicate mixture
of grains yields the observed extinction curve with the simple power-law
distribution of the grain size but with a cutoff at some maximal size: the
parameters are tightly constrained to be $q = 3.5 \pm 0.2$ for the size
distribution $a^{-q}$ and the maximum radius $a_{max} = 0.24 \pm 0.05$ um, for
both MW and SMC. The abundance of grains, and hence the elemental abundance, is
constrained from the reddening versus hydrogen column density, E(B-V)/N_H. If
we take the solar elemental abundance as the standard for the MW, >56 % of
carbon should be in graphite dust, while it is <40 % in the SMC using its
available abundance estimate. This disparity and the relative abundance of C to
Si explain the difference of the two curves. We find that 50-60 % of carbon may
not necessarily be in graphite but in the amorphous or the glassy phase. Iron
may also be in the metallic phase or up to ~80 % in magnetite rather than in
silicates, so that the Mg/Fe ratio in astronomical olivine is arbitrary. With
these substitutions the parameters of the grain size remain unchanged. The mass
density of dust grains relative to hydrogen is $\rho_{dust}/\rho_H = 1/(120
{+10 \atop -16})$ for the MW and $1/(760 {+70 \atop -90}) for the SMC under
some abundance constraints. We underline the importance of the
wavelength-dependence slope of the extinction curve in the near infrared in
constructing the dust model: if $A_{\lambda} \propto \lambda^{-gamma}$ with
gamma ~ 1.6, the power-law grain-size model fails, whereas it works if gamma ~
1.8-2.0.


title: A note on the growth of Betti numbers and ranks of 3-manifold groups

abstract:
  Let N be an irreducible, compact 3-manifold with empty or toroidal boundary
which is not a closed graph manifold. Using recent work of Agol, Kahn-Markovic
and Przytycki-Wise we will show that pi_1(N) admits a cofinal filtration with
`fast' growth of Betti numbers as well as a cofinal filtration of pi_1(N) with
`slow' growth of ranks.


title: Defect states and spin-orbital physics in doped vanadates Y1-xCaxVO3

abstract:
  We present a model for typical charged defects in weakly doped Y1-xCaxVO3
perovskites and study how they influence the magnetic and orbital order.
Starting from a multiband Hubbard model, we show that the charge carriers
introduced by doping are bound to the Ca defects with large binding energy of
about 1 eV at small doping, and give rise to the in-gap absorption band
observed in the optical spectroscopy. The central position of a generic Ca
defect with eight equidistant vanadium neighbors implies a partly filled defect
band and permits activated transport due to Coulomb disorder. We explore the
effect of bound charge carriers on the dynamics of the (yz,zx) orbital and spin
degrees of freedom in the context of a spin-orbital t-J model. After deriving
the superexchange interactions around the doped hole, we show that the
transition from G-type to C-type antiferromagnetic (AF) order is triggered by
the kinetic energy of doped holes via the double-exchange mechanism. The defect
states lead to local modification of orbital correlations within ferromagnetic
chains along the c axis; some of them contain hole defects, while the
charge-orbital coupling suppresses locally (yz,zx) orbital fluctuations in the
others. Thereby, Ca defects provide a physical mechanism for spin-orbital
dimerization along the ferromagnetic bonds, suggesting that, in the C-AF phase
of weakly doped Y1-xCaxVO3, dimerization increases with doping.


title:
Beyond Bell's theorem: Admissible hidden-variable models for the
  spin-singlet

abstract:
  Assuming that quantum mechanics is obeyed exactly after averaging over hidden
variables, and considering models that obey both the hypotheses of free will
and locality, we establish the form of all possible hidden-variable models that
reproduce the spin-singlet.


title: Do we need the g-index?

abstract:
  Using a very small sample of 8 datasets it was recently shown by De Visscher
(2011) that the g-index is very close to the square root of the total number of
citations. It was argued that there is no bibliometrically meaningful
difference. Using another somewhat larger empirical sample of 26 datasets I
show that the difference may be larger and I argue in favor of the g-index.


title:
On relative hyperbolicity for a group and relative quasiconvexity for a
  subgroup

abstract:
  We consider two families of subgroups of a group. Each subgroup which belongs
to one family is contained in some subgroup which belongs to the other family.
We then discuss relations of relative hyperbolicity for the group with respect
to the two families, respectively. If the group is supposed to be hyperbolic
relative to the two families, respectively, then we consider relations of
relative quasiconvexity for a subgroup of the group with respect to the two
families, respectively.


title: Diffusive Limits for Adaptive MCMC for Normal Target densities

abstract:
  In this paper we apply the Diffusion approximation procedure to a discrete
time Adaptive Markov Chain Monte Carlo (AMCMC) method when the target
distribution is standard Normal. We show that the limiting distribution of the
diffusion admits a density which we identify as the standard Normal
distribution.


title: The robustness of equilibria on convex solids

abstract:
  We examine the minimal magnitude of perturbations necessary to change the
number $N$ of static equilibrium points of a convex solid $K$. We call the
normalized volume of the minimally necessary truncation robustness and we seek
shapes with maximal robustness for fixed values of $N$. While the upward
robustness (referring to the increase of $N$) of smooth, homogeneous convex
solids is known to be zero, little is known about their downward robustness.
The difficulty of the latter problem is related to the coupling (via integrals)
between the geometry of the hull $\bd K$ and the location of the center of
gravity $G$. Here we first investigate two simpler, decoupled problems by
examining truncations of $\bd K$ with $G$ fixed, and displacements of $G$ with
$\bd K$ fixed, leading to the concept of external \rm and internal \rm
robustness, respectively. In dimension 2, we find that for any fixed number
$N=2S$, the convex solids with both maximal external and maximal internal
robustness are regular $S$-gons. Based on this result we conjecture that
regular polygons have maximal downward robustness also in the original, coupled
problem. We also show that in the decoupled problems, 3-dimensional regular
polyhedra have maximal internal robustness, however, only under additional
constraints. Finally, we prove results for the full problem in case of 3
dimensional solids. These results appear to explain why monostatic pebbles
(with either one stable, or one unstable point of equilibrium) are found so
rarely in Nature.


title: European wind variability over 140 yr

abstract:
  We present initial results of a study on the variability of wind speeds
across Europe over the past 140 yr, making use of the recent Twentieth Century
Reanalysis data set, which includes uncertainty estimates from an ensemble
method of reanalysis. Maps of the means and standard deviations of daily wind
speeds, and the Weibull-distribution parameters, show the expected features,
such as the strong, highly-variable wind in the north-east Atlantic. We do not
find any clear, strong long-term trends in wind speeds across Europe, and the
variability between decades is large. We examine how different years and
decades are related in the long-term context, by looking at the ranking of
annual mean wind speeds. Picking a region covering eastern England as an
example, our analyses show that the wind speeds there over the past ~ 20 yr are
within the range expected from natural variability, but do not span the full
range of variability of the 140-yr data set. The calendar-year 2010 is however
found to have the lowest mean wind speed on record for this region.


title:
Rigorous pointwise approximations for invariant densities of
  nonuniformly expanding maps

abstract:
  We use an Ulam-type discretization scheme to provide pointwise approximations
for invariant densities of interval maps with a neutral fixed point. We prove
that the approximate invariant density converges pointwise to the true density
at a rate $C^*\cdot\frac{\ln m}{m}$, where $C^*$ is a computable fixed constant
and $m^{-1}$ is the mesh size of the discretization.


title: Ergodicity of some open systems with particle-disk interactions

abstract:
  We consider steady states for a class of mechanical systems with
particle-disk interactions coupled to two, possibly unequal, heat baths. We
show that any steady state that satisfies some natural assumptions is ergodic
and absolutely continuous with respect to a Lebesgue-type reference measure and
conclude that there exists at most one absolutely continuous steady state.


title: Brief Report on the Extended Linear Sigma Model

abstract:
  We present a chiral effective model which exhibits all the known symmetry
features of the QCD Lagrangian. The extended Linear Sigma Model (eLSM) includes
(pseudo-)scalar and (axial-) vector mesons, glueballs, and baryons. It has
proven to be a useful tool to understand the nature of the low-energy
resonances. It can be used to describe the masses and decay widths of the known
low-energy mesons and to disentangle the complicated picture of resonances in
the low-energy range. We can answer some of the open questions in the
low-energy region, e.g. the resonance (f_0(1500)) is a predominantly glueball
state and the resonance (f_0(1370)) is most likely the chiral partner of the
pion. We could also find that the resonance (N(1650)) is favoured as the chiral
partner of the nucleon (N(939)). In addition the temperature dependence of the
chiral condensate and the glueball condensate can be used to study the phase
diagram at nonzero temperatures and densities. At nonzero density we achieve
nuclear matter saturation.


title: A Ginzburg-Landau model for the expansion of a dodecahedral viral capsid

abstract:
  We propose a Ginzburg-Landau model for the expansion of a dodecahedral viral
capsid during infection or maturation. The capsid is described as a
dodecahedron whose faces, meant to model rigid capsomers, are free to move
independent of each other, and has therefore twelve degrees of freedom. We
assume that the energy of the system is a function of the twelve variables with
icosahedral symmetry. Using techniques of the theory of invariants, we expand
the energy as the sum of invariant polynomials up to fourth order, and classify
its minima in dependence of the coefficients of the Ginzburg-Landau expansion.
Possible conformational changes of the capsid correspond to symmetry breaking
of the equilibrium closed form. The results suggest that the only generic
transition from the closed state leads to icosahedral expanded form. Our
approach does not allow to study the expansion pathway, which is likely to be
non-icosahedral.


title:
Testing the Standard Model in $B \to D \tau \bar \nu$ decay with minimal
  theory input

abstract:
  Recent experimental results for the ratio of the branching fractions of $\bar
B \to D^{(*)}\tau \nu_\tau$ and $B\to D^{(*)} \mu \nu_\mu$ decays came as a
surprise and lead to a discussion of possibility to constraining new physics
through these modes. Here we focus on $Br(B \to D \tau \bar\nu_\tau)/Br(B \to D
\mu \bar\nu_\mu)$ and argue that the result is consistent with the Standard
Model within $2\,\sigma$ and that the test of compatibility of this ratio with
the Standard Model can be done experimentally with a minimal theory input. We
also show that these two decay channels can provide us with quite good
constraints of the new physics couplings.


title: Noether's problem for p-groups with three generators

abstract:
  Let $p$ be an odd prime and $G$ be a nonabelian group of order $p^{n}$ with
the presentation $$<\alpha,\beta,\gamma\mid
\alpha^{p^{a}}=\beta^{p^{b}}=\gamma^{p^{c}}=1,
[\alpha,\gamma]=1,[\gamma,\beta]=\alpha^{p^{r}},[\alpha,\beta]=\gamma^{p^{e}}>,$$
where $n>a\geq b\geq c\geq 1$. Let $k$ be a field containing a primitive
$p^{a}$-th root of unity and $G$ act on the rational function field
$k(x_{h}:h\in G)$ by $g\cdot x_{h}=x_{gh}$ for all $g,h\in G$. In this note, we
prove that the fixed field $k(G)=k(x_{h}:h\in G)^{G}$ is rational over $k$. As
a corollary, we prove that if $k$ contains a primitive $p^{4}$-th root of unity
and $G$ is a nonabelian group of order $p^{5}$ generated by three elements,
then $k(G)$ is rational over $k$.


title: The Komlos Conjecture Holds for Vector Colorings

abstract:
  The Komlos conjecture in discrepancy theory states that for some constant K
and for any m by n matrix A whose columns lie in the unit ball there exists a
+/- 1 vector x such that the infinity norm of Ax is bounded above by K. This
conjecture also implies the Beck-Fiala conjecture on the discrepancy of bounded
degree hypergraphs. Here we prove a natural relaxation of the Komlos
conjecture: if the columns of A are assigned unit real vectors rather than +/-
1 then the Komlos conjecture holds with K=1. Our result rules out the
possibility of a counterexample to the conjecture based on semidefinite
programming. It also opens the way to proving tighter efficient
(polynomial-time computable) upper bounds for the conjecture using semidefinite
programming techniques.


title:
Relevance of coordinate and particle-number scaling in density
  functional theory

abstract:
  We discuss a $\beta$-dependent family of electronic density scalings of the
form $n_\lambda(\R)=\lambda^{3\beta+1}\; n(\lambda^\beta \R)$ in the context of
density functional theory. In particular, we consider the following special
cases: the Thomas-Fermi scaling ($\beta=1/3$ and $\lambda \gg 1$), which is
crucial for the semiclassical theory of neutral atoms; the uniform-electron-gas
scaling ($\beta=-1/3$ and $\lambda\gg 1$), that is important in the
semiclassical theory of metallic clusters; the homogeneous density scaling
($\beta=0$) which can be related to the self-interaction problem in density
functional theory when $\lambda \leq 1$; the fractional scaling ($\beta=1$ and
$\lambda\leq 1$), that is important for atom and molecule fragmentation; and
the strong-correlation scaling ($\beta=-1$ and $\lambda \gg 1$) that is
important to describe the strong correlation limit.
  The results of our work provide evidence for the importance of this family of
scalings in semiclassical and quantum theory of electronic systems, and
indicate that these scaling properties must be considered as important
constraints in the construction of new approximate density functionals. We also
show, using the uniform-electron-gas scaling, that the curvature energy of
metallic clusters is related to the second-order gradient expansion of kinetic
and exchange-correlation energies.


title:
Blind extraction of an exoplanetary spectrum through Independent
  Component Analysis

abstract:
  Blind-source separation techniques are used to extract the transmission
spectrum of the hot-Jupiter HD189733b recorded by the Hubble/NICMOS instrument.
Such a 'blind' analysis of the data is based on the concept of independent
component analysis. The de-trending of Hubble/NICMOS data using the sole
assumption that nongaussian systematic noise is statistically independent from
the desired light-curve signals is presented. By not assuming any prior, nor
auxiliary information but the data themselves, it is shown that spectroscopic
errors only about 10 - 30% larger than parametric methods can be obtained for
11 spectral bins with bin sizes of ~0.09 microns. This represents a reasonable
trade-off between a higher degree of objectivity for the non-parametric methods
and smaller standard errors for the parametric de-trending. Results are
discussed in the light of previous analyses published in the literature. The
fact that three very different analysis techniques yield comparable spectra is
a strong indication of the stability of these results.


title:
GUP-based and Snyder Non-Commutative Algebras, Relativistic Particle
  models and Deformed Symmetries: A Unified Approach

abstract:
  We have developed a unified scheme for studying Non-Commutative algebras
based on Generalized Uncertainty Principle (GUP) and Snyder form in a
relativistically covariant point particle Lagrangian (or symplectic) framework.
Even though the GUP based algebra and Snyder algebra are very distinct, the
more involved latter algebra emerges from an approximation of the Lagrangian
model of the former algebra. Deformed Poincare generators for the systems that
keep space-time symmetries of the relativistic particle models have been
studied thoroughly.
  From a purely constrained dynamical analysis perspective the models studied
here are very rich and provide insights on how to consistently construct
approximate models from the exact ones when non-linear constraints are present
in the system.
  We also study dynamics of the GUP particle in presence of external
electromagnetic field.


title:
Carrier localization and out of plane anisotropic magnetoresistance in
  $Nd_{0.55-x} Sm_x Sr_{0.45} Mn O_3$ thin films

abstract:
  The impact of carrier localization on the anisotropic magnetoresistance (AMR)
has been investigated in NSSMO thin films. Carrier localization is caused by
the reduced average radius of the A-site of the perovskite lattice and enhanced
size disorder due to substitution of smaller cations for larger.


title: Constraints from Cosmography in various parameterizations

abstract:
  We use cosmography to present constraints on the kinematics of the Universe
without postulating any underlying theoretical model a priori. To this end, we
use a Markov Chain Monte Carlo analysis to perform comparisons to the supernova
Ia union 2 compilation, combined with the Hubble Space Telescope measurements
of the Hubble constant, and the Hubble parameter datasets. The cosmographic
approach to our analysis is revisited and extended for new notions of redshift
presented as alternatives to the redshift z. Furthermore, we introduce a new
set of fitting parameters describing the kinematical evolution of the Universe
in terms of the equation of state of the Universe and derivatives of the total
pressure. Our results are consistent with the \Lambda CDM model, although
alternative models, with nearly constant pressure and no cosmological constant,
match the results accurately as well.


title: n-DBI Gravity in a nutshell

abstract:
  We present a new model of gravity which explicitly breaks Lorentz-invariance
by the introduction of a unit time-like vector field, thereby giving rise to an
extra (scalar) degree of freedom. We discuss its cosmology, exact solutions and
the dynamics of the scalar mode. We show that it predicts inflation without an
inflaton and admits the black hole solutions of General Relativity (GR). We
argue that the scalar mode is well behaved and contains none of the pathologies
previously found in similar models.


title:
Impact of strain on metamagnetic transitions in $Sm_{0.5} Sr_{0.5} Mn
  O_3$ thin films

abstract:
  SSMO50 thin films were deposited by DC magnetron sputtering on LAO and STO
substrates. The film on LAO is under compressive strain, while the film on STO
is under tensile strain. All the magnetic and magnetotransport properties have
been discussed in terms of strain controlled metamagnetic state.


title:
Infinitesimal deformations of the model $\mathbb{Z}_3$-filiform Lie
  algebra

abstract:
  In this work it is considered the vector space composed by the infinitesimal
deformations of the model $\mathbb{Z}_3$-filiform Lie algebra $L^{n,m,p}$. By
using these deformations all the $\mathbb{Z}_3$-filiform Lie algebras can be
obtained, hence the importance of these deformations. The results obtained in
this work together to those obtained in [Integrable deformations of nilpotent
color Lie superalgebras, J. Geom. Phys. 61(2011)1797-1808] and [Corrigendum to
Integrable deformations of nilpotent color Lie superalgebras, J. Geom. Phys.
62(2012)1571], leads to compute the total dimension of the mentioned space of
deformations.


title:
Low field anisotropic colossal magnetoresistance in $Sm_{0.53} Sr_{0.47}
  Mn O_3$ thin films

abstract:
  SSMO5347 thin films (thicknesses ~200 nm) were deposited by on-axis dc
magnetron sputtering on the single crystal LSAT (001) substrates. These films
are oriented along the out of plane c-direction. The ferromagnetic and
insulator-metal transition occurs at 96 K and 91 K, respectively. The
magnetization easy axis is observed to lie in the plane of the film while the
magnetic hard axis is found to be along the normal to this. The
magnetotransport of the SSMO films, which was measured as a function of angle
(theta) between the magnetic field (H) and plane of the film, shows colossal
anisotropy. Magnetoresistance (MR) decreases drastically as theta increases
from 0 degree (H//easy axis) to 90 degree (H//hard axis). The out-of-plane
anisotropic MR (AMR) is as high as 88 % at H=3.6 kOe and 78 K. The colossal
anisotropy has been explained in terms of the magnetic anisotropies at play and
the magnetic domain motion in applied magnetic field.


title: Ergodic properties of random billiards driven by thermostats

abstract:
  We consider a class of mechanical particle systems interacting with
thermostats. Particles move freely between collisions with disk-shaped
thermostats arranged periodically on the torus. Upon collision, an energy
exchange occurs, in which a particle exchanges its tangential component of the
velocity for a randomly drawn one from the Gaussian distribution with the
variance proportional to the temperature of the thermostat. In the case when
all temperatures are equal one can write an explicit formula for the stationary
distribution. We consider the general case and show that there exists a unique
absolutely continuous stationary distribution. Moreover under rather mild
conditions on the initial distribution the corresponding Markov dynamics
converges to the equilibrium with exponential rate. One of the main technical
difficulties is related to a possible overheating of moving particle. However
as we show in the paper non-compactness of the particle velocity can be
effectively controlled.


title: Punctured Trellis-Coded Modulation

abstract:
  In classic trellis-coded modulation (TCM) signal constellations of twice the
cardinality are applied when compared to an uncoded transmission enabling
transmission of one bit of redundancy per PAM-symbol, i.e., rates of
$\frac{K}{K+1}$ when $2^{K+1}$ denotes the cardinality of the signal
constellation. In order to support different rates, multi-dimensional (i.e.,
$\mathcal{D}$-dimensional) constellations had been proposed by means of
combining subsequent one- or two-dimensional modulation steps, resulting in
TCM-schemes with $\frac{1}{\mathcal{D}}$ bit redundancy per real dimension. In
contrast, in this paper we propose to perform rate adjustment for TCM by means
of puncturing the convolutional code (CC) on which a TCM-scheme is based on. It
is shown, that due to the nontrivial mapping of the output symbols of the CC to
signal points in the case of puncturing, a modification of the corresponding
Viterbi-decoder algorithm and an optimization of the CC and the puncturing
scheme are necessary.


title:
Topics in Noncommutative Gauge Theories and Deformed Relativistic
  Theories

abstract:
  This is my PhD thesis. In this thesis we study the gauge theories on
noncommutative Moyal space. We find new static solitons and instantons in terms
of the so called generalized Bose operators. Generalized Bose operators are
constructed to describe reducible representation of the oscillator algebra.
They create/annihilate $k$-quanta, $k$ being a positive integer. We start with
giving an alternative description to the already found static magnetic flux
tube solutions of the noncommutative gauge theories in terms of generalized
Bose operators. The Nielsen-Olesen vortex solutions found in terms of these
operators reduce to the already found ones. On the contrary we find a class of
new instaton solutions which are unitarily inequivalant to the the ones found
from ADHM construction on noncommutative space. The charge of the instaton has
a description in terms of the index representing the reducibility of the Fock
space, i.e., $k$. After studying the static solitonic solutions in
noncommutative Minkowski space and the instaton solutions in noncommutative
Euclidean space we go on to study the implications of the time-space
noncommutativity in Minkowski space. To understand it properly we study the
time-dependent transitions of a forced harmonic oscillator in noncommutative
1+1 dimensional spacetime. We also try to understand the implications of the
found results in the context of quantum optics. We then shift to the so called
DSR theories which are related to a different kind of noncommutative
($\kappa$-Minkowski) space. DSR (Doubly/Deformed Special Relativity) aims to
search for an alternate relativistic theory which keeps a length/energy scale
(the Planck scale) and a velocity scale (the speed of light scale) invariant.
We study thermodynamics of an ideal gas in such a scenario.


title:
Impact of growth conditions on the nature of magnetism and
  magnetotransport of $Sm_{0.55} Sr_{0.45} Mn O_3$ thin films

abstract:
  The impact of growth conditions on the magnetic and electrical transport
properties of oriented polycrystalline Sm0.55Sr0.45MnO3 thin films prepared on
nearly lattice matching LSAT(100) single crystal substrates by nebulized spray
pyrolysis has been studied.


title: On a Hierarchy of Means

abstract:
  For a class of partially ordered means we introduce a notion of the
(nontrivial) cancelling mean. A simple method is given which helps to determine
cancelling means for well known classes of Holder and Stolarsky means.


title:
Dielectric properties of Poly(vinylidene fluoride) / CaCu3Ti4O12
  composites

abstract:
  The possibility of obtaining relatively high dielectric constant
polymer-ceramic composite by incorporating the giant dielectric constant
material, CaCu3Ti4O12 (CCTO) in a Poly(vinylidene fluoride) (PVDF) polymer
matrix by melt mixing and hot pressing process was demonstrated. The structure,
morphology and dielectric properties of the composites were characterized using
X ray diffraction, Thermal analysis, Scanning Electron Microscope, and
Impedance analyzer. The effective dielectric constant of the composite
increased with increase in the volume fraction of CCTO at all the frequencies
(100 Hz to 1MHz) under study. The dielectric loss did not show any variation
upto 40 % loading of CCTO, but showed an increasing trend beyond 40%. The room
temperature dielectric constant as high as 95 at 100Hz has been realized for
the composite with 55 Vol % of CCTO, which has increased to about 190 at 150oC.
Theoretical models like Maxwells Clausius Mossotti, Effective medium theory,
logarithmic law and Yamada were employed to rationalize the dielectric
behaviour of the composite and discussed. Keywords: A. Ceramic; A. Polymer
matrix composite


title: Structure and eigenvalues of heat-bath Markov chains

abstract:
  We prove that heat-bath chains (which we define in a general setting) have no
negative eigenvalues. Two applications of this result are presented: one to
single-site heat-bath chains for spin systems and one to a heat-bath Markov
chain for sampling contingency tables. Some implications of our main result for
the analysis of the mixing time of heat-bath Markov chains are discussed. We
also prove an alternative characterisation of heat-bath chains, and consider
possible generalisations.


title:
Dielectric properties of Poly(vinylidene fluoride)/ CaCu3Ti4O12
  nanocrystal composite thick films

abstract:
  The Poly(vinylidene fluoride)/CaCu3Ti4O12 (CCTO) nanocrystal composite films
(85nm) with relatively high dielectric permittivity (90 at 100Hz) were prepared
by the solution casting followed by spin coating technique. The structural, the
microstructural and the dielectric properties of the composites were studied
using X-ray diffraction, Scanning Electron Microscope, and Impedance analyzer
respectively. The effective dielectric permittivity of the composite increased
with increase in the volume fraction of CCTO at all the frequencies (100 Hz to
1MHz) under investigation. The room temperature dielectric permittivity which
is around 90 at 100Hz, has increased to about 290 at 125oC (100Hz). These
results may be exploited in the development of high energy density capacitors.


title: Nonperturbative results on the quark-gluon vertex

abstract:
  We present analytical and numerical results for the Dirac form factor of the
quark-gluon vertex in the quark symmetric limit, where the incoming and
outgoing quark momenta have the same magnitude but opposite sign. To accomplish
this, we compute the relevant components of the quark-ghost scattering kernel
at the one-loop dressed approximation, using as basic ingredients the full
quark propagator, obtained as a solution of the quark gap equation, and the
gluon propagator and ghost dressing function, obtained from large-volume
lattice simulations.


title:
Measurements of inclusive J/psi production in Pb-Pb collisions at
  sqrt(s_NN) = 2.76 TeV with the ALICE experiment

abstract:
  Charmonium is a prominent probe of the Quark-Gluon Plasma (QGP), expected to
be formed in ultrarelativistic heavy-ion (A-A) collisions. It has been
predicted that the J/psi(c-cbar) particle is dissolved in the deconfined medium
created in A-A systems. However this suppression can be counterbalanced via
regeneration of the charm/anti-charm bound state in QGP or via statistical
production at the phase boundary. At LHC energies, the latter mechanisms are
expected to play a more important role, due to a charm production cross section
significantly larger than at lower energies.
  Measurements obtained by the ALICE experiment for inclusive J/psi production
are shown, making use of Pb-Pb data at sqrt(s_NN) = 2.76 TeV, collected in 2010
and 2011. In particular, the focus is given on the nuclear modification factor,
R_AA, derived for forward (2.5 < y < 4) and mid rapidities (|y| < 0.9), both
down to zero transverse momentum (pT). The centrality, y and pT dependences of
R_AA are presented and discussed in the context of theoretical models, together
with PHENIX and CMS results.


title: Convex hulls of planar random walks with drift

abstract:
  Denote by $L_n$ the length of the perimeter of the convex hull of $n$ steps
of a planar random walk whose increments have finite second moment and non-zero
mean. Snyder and Steele showed that $n^{-1} L_n$ converges almost surely to a
deterministic limit, and proved an upper bound on the variance $Var [ L_n] =
O(n)$. We show that $n^{-1} Var [L_n]$ converges and give a simple expression
for the limit, which is non-zero for walks outside a certain degenerate class.
This answers a question of Snyder and Steele. Furthermore, we prove a central
limit theorem for $L_n$ in the non-degenerate case.


title:
Constraints on the quark matter equation of state from astrophysical
  observations

abstract:
  We calculate the structure of neutron star interiors comprising both the
hadronic and the quark phases. For the hadronic sector we employ a microscopic
equation of state involving nucleons and hyperons derived within the
Brueckner-Hartree-Fock many-body theory with realistic two-body and three-body
forces. For the description of quark matter, we use several different models,
e.g. the MIT bag, the Nambu--Jona-Lasinio (NJL), the Color Dielectric (CDM),
the Field Correlator method (FCM), and one based on the Dyson-Schwinger model
(DSM). We find that a two solar mass hybrid star is possible only if the
nucleonic EOS is stiff enough.


title: The effective gluon mass and its dynamical equation

abstract:
  We present the general derivation of the full nonperturbative equation that
governs the momentum evolution of the dynamically generated gluon mass, in the
Landau gauge. The gluon mass originates from the inclusion of longitudinally
coupled vertices containing massless poles of non-perturbative origin, which
preserve the form of the fundamental Slavnov-Taylor identities of the theory.
The equation is obtained within the PT-BFM formalism, where the corresponding
Schwinger-Dyson equation involves a reduced number of fully dressed diagrams.
The resulting homogeneous integral equation is solved numerically for the
entire range of physical momenta, yielding positive-definite and monotonically
decreasing gluon masses, in agreement with a variety of less formal
considerations.


title:
Effect of calcium stoichiometry on the dielectric response of
  CaCu3Ti4O12 Ceramics

abstract:
  CaxCu3Ti4O12 polycrystalline powders with variation in calcium content were
prepared via the oxalate precursor route. The structural, morphological and
dielectric properties of the ceramics fabricated using these powders were
studied using x ray diffraction, Scanning Electron Microscope along with Energy
Dispersive X ray Analysis, Transmission Electron Microscopy, Electron Spin
Resonance (ESR) spectroscopy and Impedance analyzer. The X ray diffraction
patterns obtained for the x = 0.97, 1.0 and 1.1 powdered ceramics could be
indexed to a body centered cubic perovskite related structure associated with
the space group Im3. The ESR studies confirmed the absence of oxygen vacancies
in the ceramics that were prepared using the oxalate precursor route. The
dielectric properties of these suggest that the calcium deficient sample (x=
0.97) has a reduced dielectric loss while retaining the high dielectric
constant which is of significant industrial relevance.


title:
Three-dimensional orientation measurement of a single fluorescent
  nanoemitter by polarization analysis

abstract:
  We demonstrate theoretically and experimentally that the three-dimensional
orientation of a single fluorescent nano-emitter can be determined by
polarization analysis of the emitted light (while excitation polarization
analysis provides only the in-plane orientation). The determination of the
emitter orientation by polarimetry requires a theoretical description including
the objective numerical aperture, the 1D or 2D nature of the emitting dipole
and the environment close to the dipole. We develop a model covering most
experimentally relevant microscopy configurations and provide analytical
relations useful for orientation measurements. We perform polarimetric
measurements on high-quality core-shell CdSe/CdS nanocrystals and demonstrate
that they can be approximated by two orthogonal degenerated dipoles. Finally,
we show that the orientation of a dipole can be inferred by polarimetric
measurement even for a dipole in the vicinity of a gold film, while in this
case the well-established defocused microscopy is not appropriate.


title:
Nanoparticles of the giant dielectric material, CaCu3Ti4O12 from a
  precursor route

abstract:
  A method of preparing the nanoparticles of CaCu3Ti4O12 (CCTO) with the
crystallite size varying from 30 to 200 nm is optimized at a temperature as low
as 680 1C from the exothermic thermal decomposition of an oxalate precursor,
CaCu3(TiO)4(C2O4)8 ? 9H2O. The phase singularity of the complex oxalate
precursor is confirmed by the wet chemical analyses, X-ray diffraction, FT-IR
and TGA,DTA analyses. The UV Vis reflectance and ESR spectra of CCTO powders
indicate that the Cu(II) coordination changes from distorted octahedra to
nearly flattened tetrahedra (squashed) to square-planar geometry with
increasing annealing temperature. The HRTEM images have revealed that the
evolution of the microstructure in nanoscale is related to the change in Cu(II)
coordination around the surface regions for the chemically prepared powder
specimens. The nearly flattened tetrahedral geometry prevails for CuO4 in the
near surface regions of the particles, whereas square-planar CuO4 groups are
dominant in the interior regions of the nanoparticles. The powders derived from
the oxalate precursor have excellent sinterability, resulting in high-density
ceramics which exhibited giant dielectric constants upto 40,000 (1 kHz) at 25
1C, accompanied by low dielectric loss 0.07.


title: Gauss map of translating solitons of mean curvature flow

abstract:
  In this short note we study Bernstein's type theorem of translating solitons
whose images of their Gauss maps are contained in compact subsets in an open
hemisphere of the standard $\mathbf{S}^n$ (see Theorem 1.1). As a special case
we get a classical Bernstein's type theorem in minimal submanifolds in
$\mathbf{R}^{n+1}$ (see Corollary 1.2).


title:
Structural and dielectric properties of glasses in the system
  TeO2-CaCu3Ti4O12

abstract:
  The glasses in the system (100-x)TeO2-xCaCu3Ti4O12, (x=0.25 to 3 mol %) were
fabricated. The color varied from olive green to brown as the CaCu3Ti4O12
(CCTO) content increased in TeO2 matrix. The X-ray powder diffraction and
differential scanning calorimetric analyses that were carried out on the
as-quenched samples confirmed their amorphous and glassy nature respectively.
The dielectric constant and loss in the 100 Hz-1MHz frequency range were
monitored as a function of temperature (50-400oC). The dielectric constant and
the loss (D) increased as the CCTO content increased in TeO2 at all the
frequencies and temperatures under investigation. Further, the effective
dielectric constant and D were found to be frequency independent in the
50-200oC temperature range. The value obtained for the loss at 1MHz was 0.0019
which was typical of low loss materials, and exhibited near constant loss (NCL)
in the 100Hz-1MHz frequency range. The electrical relaxation was rationalized
using the electric modulus formalism. These glasses may be of considerable
interest as substrates for high frequency circuit elements in conventional
semiconductor industries owing to their high thermal stability.


title:
Computation of the effective slip of rough hydrophobic surfaces via
  homogenization

abstract:
  We present a quantitative analysis of the effect of rough hydrophobic
surfaces on viscous newtonian flows. We use a model introduced by Ybert and
coauthors in which the rough surface is replaced by a flat plane with
alternating small areas of slip and no-slip. We investigate the averaged slip
generated at the boundary, depending on the ratio between these areas. This
problem reduces to the homogenization of a non-local system, involving the
Dirichlet to Neumann map of the Stokes operator, in a domain with small holes.
Pondering on works by Allaire, we compute accurate scaling laws of the averaged
slip for various types of roughness (riblets, patches). Numerical computations
complete and confirm the analysis.


title:
In-situ synthesis and characterization of polyaniline -CaCu3Ti4O12 nano
  crystal composites

abstract:
  High dielectric constant nano composite of Polyaniline (PANI) CaCu3Ti4O12
(CCTO) was synthesized using a simple procedure involving in-situ
polymerization of aniline in dil. HCl. The PANI and the composite were
subjected to X-ray diffraction, Fourier transform infrared, Thermo gravimetric,
Scanning electron microscopy and Transmission electron microscopy analyses. The
presence of the nano crystallites of CCTO embedded in the nanofibers of PANI
matrix was established by TEM. Frequency dependent characteristics of the
dielectric constant, dielectric loss and AC conductivity were studied for the
PANI and the composites. The dielectric constant increased as the CCTO content
increased in PANI but decreased with increasing frequency of measurement. The
dielectric loss was two times less than the value obtained for pure PANI around
100Hz. The AC conductivity increased slightly upto 2kHz as the CCTO content
increased in the PANI which was attributed to the polarization of the charge
carriers.


title:
Impact of size mismatch induced quenched disorder on phase fluctuation
  and low field magnetotransport in polycrystalline $Nd_{0.58-x} Gd_x Sr_{0.42}
  Mn O_3$

abstract:
  We report the magnetic and electrical transport properties of the bulk
polycrystalline NGSMO (x ~ 0.0, 0.04, 0.08, 0.12, 0.16, 0.20, 0.25, 0.30, 0.35
and 0.42) synthesized by solid state reaction at 1350 degree Celsius. All the
samples are single phase and have grain size ~1-2 micrometer. The variation of
magnetic and magnetotransport properties as a function of the variance sigma^2
show some interesting trends. As sigma^2 increases, the
paramagnetic-ferromagnetic (PM-FM) transition shows a gradual decrease and
broadening, while the decrease in insulator metal transition (IMT) is
accompanied by sharpening. However, near equality of TC and TIM at intermediate
values of sigma2 could be understood in terms of the competing quenched and the
grain boundary disorder. The variation of peak MR (maximum MR around TC/TIM)
with sigma2 shows that maximum low field MR =35 % at H=3 kOe (68 % at H=10 kOe)
is centered around sigma2 = 0.009857 {A}2 (x=0.25). This shows that huge
intrinsic MR can be obtained at relatively higher temperatures and lower
magnetic fields in the region of enhanced phase fluctuations.


title:
Dielectric properties of Poly(methyl methacrylate) (PMMA)/CaCu3Ti4O12
  Composites

abstract:
  Materials with high dielectric constant are in great demand for the
miniaturization of electronic devices. More specifically, high dielectric
constant polymer-ceramic composites are useful for embedded capacitor
applications. A composite consisting of giant dielectric CaCu3Ti4O12 (CCTO)
incorporated into the Poly(methyl methacrylate) (PMMA) polymer matrix has been
fabricated by melt mixing followed by hot pressing. The composites thus
fabricated has been characterised for structural, morphological and dielectric
properties. The composites dielectric constants had increased when the CCTO
content increased in the PMMA matrix. The dielectric constant of PMMA is around
4.9 @ 100Hz which has increased to 15.7 @ 100Hz when the ceramic content has
increased to 40 Vol %. At low frequencies, space charge polarisation is
dominant. This composite also exhibited remarkably low dielectric loss at high
frequency, which makes this composite a suitable candidate for the capacitors
in high frequency application.


title: Measure-valued solutions for models of ferroelectric material behavior

abstract:
  In this work we study the solvability of the initial boundary value problems,
which model a quasi-static nonlinear behavior of ferroelectric materials.
Similar to the metal plasticity the energy functional of a ferroelectric
material can be additively decomposed into reversible and remanent parts. The
remanent part associated with the remanent state of the material is assumed to
be a convex non-quadratic function $f$ of internal variables. In this work we
introduce the notion of the measure-valued solutions for the ferroelectric
models and show their existence in the rate-dependent case assuming the
coercivity of the function $f$. Regularizing the energy functional by a
quadratic positive definite term, which can be viewed as hardening, we show the
existence of measure-valued solutions for the rate-independent and
rate-dependent problems avoiding the coercivity assumption on $f$.


title: Classification of Angle-Symmetric 6R Linkage

abstract:
  In this paper, we consider a special kind of overconstrained 6R closed
linkages which we call angle-symmetric 6R linkages. These are linkages with the
property that the rotation angles are equal for each of the three pairs of
opposite joints. We give a classification of these linkages. It turns that
there are three types. First, we have the linkages with line symmetry. The
second type is new. The third type is related to cubic motion polynomials.


title: A resultant for Hensel's Lemma

abstract:
  Let R be a complete discrete valuation ring with maximal ideal generated by
pi. Let f(X) in R[X] be a monic polynomial with nonzero discriminant Delta(f).
Let s >= v_pi(Delta(f)) + 1. Suppose given a factorisation of f(X) in (R/pi^s
R)[X] into several factors, not necessarily coprime in (R/pi R)[X]. We lift it
uniquely to a factorisation of f(X) in R[X]. This generalises the
Hensel-Rychlik Lemma, which covers the case of two factors. We work directly
with lifts of factorisations into several factors and avoid having to iterate
factorisations into two factors. For this purpose we define a resultant for
several polynomials in one variable as determinant of a generalised Sylvester
matrix.


title:
Carrier-envelope phase effects on the strong-field photoemission of
  electrons from metallic nanostructures

abstract:
  Sharp metallic nanotapers irradiated with few-cycle laser pulses are emerging
as a source of highly confined coherent electron wavepackets with attosecond
duration and strong directivity. The possibility to steer, control or switch
such electron wavepackets by light is expected to pave the way towards direct
visualization of nanoplasmonic field dynamics and real-time probing of electron
motion in solid state nanostructures. Such pulses can be generated by
strong-field induced tunneling and acceleration of electrons in the near-field
of sharp gold tapers within one half-cycle of the driving laser field. Here, we
show the effect of the carrier-envelope phase of the laser field on the
generation and motion of strong-field emitted electrons from such tips. This is
a step forward towards controlling the coherent electron motion in and around
metallic nanostructures on ultrashort length and time scales.


title: Integrable Hierarchy of Multi-Component Kaup -Boussinesq Equations

abstract:
  By using the Lax approach we find the integrable hierarchy of the two and
three field Kaup-Boussinesq equations. We then give a multi-component
Kaup-Boussinesq equations and their recursion operators. Finally we show that
all multi-component Kaup-Boussinesq equations are the degenerate Svinolupov KdV
systems.


title:
Maintaining the equipartition theorem in small heterogeneous molecular
  dynamics ensembles

abstract:
  It has been reported recently that the equipartition theorem is violated in
molecular dynamics simulations with periodic boundary condition [Shirts et al,
J. Chem. Phys. 125, 164102 (2006)]. This effect is associated with the
conservation of the center of mass momentum. Here, we propose a fluctuating
center of mass molecular dynamics approach (FCMMD) to solve this problem. Using
the analogy to a system exchanging momentum with its surroundings, we work out
--and validate via simulations-- an expression for the rate at which
fluctuations shall be added to the system. The restoration of equipartition
within the FCMMD is then shown both at equilibrium as well as beyond
equilibrium in the linear response regime.


title:
Fabrication and Characterization of Poly(methyl methacrylate)CaCu3Ti4O12
  Composites

abstract:
  Composites comprising Poly(Methyl Methacrylate) (PMMA) and CaCu3Ti4O12 (CCTO)
via melt mixing followed by hot pressing were fabricated. These were
characterized using X-ray diffraction (XRD), thermo gravimetric (TGA), scanning
electron microscopy (SEM) and Impedance analyser for their structural,
morphology and dielectric properties. Composites were found to have better
thermal stability than that of pure PMMA. The composite, with 38 Vol % of CCTO
(in PMMA), exhibited remarkably low dielectric loss at high frequencies and the
low frequency relaxation is attributed to the space charge polarization MWS
effect. Theoretical models were employed to rationalise the dielectric
behaviour of these composites. At higher temperatures, the relaxation peak
shifts to higher frequencies, due to the merging of both {beta} and {alpha}
relaxations into a single dielectric dispersion peak. The AC conductivity in
the high frequency region was attributed to the electronic polarization


title:
Auslander class, $\g_C$ and $C$--projective modules modulo exact
  zero-divisors

abstract:
  For a semidualizing module $C$ over a ring $R$, we study the following
classes modulo exact zero divisors: $\g_C$--projectives, $\mathcal G_C$; the
Auslander class $\mathcal A_C$; the Bass class $\mathcal B_C$;
$\mathcal{P}_C$--projective; $ {\mathcal F}_C$--projective; and ${\mathcal
I}_C$--injective dimensions.


title: Coherent state of a weakly interacting ultracold Fermi gas

abstract:
  We examine the weakly interacting atoms in an ultracold Fermi gas leading to
a state of macroscopic coherence, from a theoretical perspective. It has been
shown that this state can be described as a fermionic coherent state. These
coherent states are the eigenstates of fermionic annihilation operators, the
eigenvalues being anti-commuting numbers or Grassmann numbers. By exploiting
the simple rules of Grassmann algebra and a close kinship between relations
evaluated for more familiar bosonic fields and those for fermionic fields, we
derive the thermodynamic limit, the spontaneous symmetry breaking and the
quasi-particle spectrum of the fermionic system.


title: Measuring Spatial Distribution of Local Elastic Modulus in Glasses

abstract:
  Glasses exhibit spatially inhomogeneous elastic properties, which can be
investigated by measuring their elastic moduli at a local scale. Various
methods to evaluate the local elastic modulus have been proposed in the
literature. A first possibility is to measure the local stress-local strain
curve and to obtain the local elastic modulus from the slope of the curve, or
equivalently to use a local fluctuation formula. Another possible route is to
assume an affine strain and to use the applied global strain instead of the
local strain for the calculation of the local modulus. Most recently a third
technique has been introduced, which is easy to be implemented and has the
advantage of low computational cost. In this contribution, we compare these
three approaches by using the same model glass and reveal the differences among
them caused by the non-affine deformations.


title:
Quantum anomalous Hall effect and tunable topological states in 3d
  transition metals doped silicene

abstract:
  We engineer quantum anomalous Hall effect in silicene via doping 3d
transition metals. We show that there exists a stable quantum anomalous Hall
effect in Vanadium doped silicene using both analytical model and Wannier
interpolation. We also predict the quantum valley Hall effect and electrically
tunable topological states could be realized in certain transition metal doped
silicene where the energy band inversion occurs. Our finding provides new
scheme for the realization of quantum anomalous Hall effect and platform for
electrically controllable topological states.


title:
Using Partial Transpose and Realignment to generate Local Unitary
  Invariants

abstract:
  Motivated by link transformations of lattice gauge theory, a method for
generating local unitary invariants, especially for a system of qubits, has
been pointed out in an earlier work [M. S. Williamson {\it et. al.}, Phys. Rev.
A {\bf 83}, 062308 (2011)]. This paper first points the equivalence of the so
constructed transformations to the combined operations of partial transpose and
realignment. This allows construction of local unitary invariants of any
system, with subsystems of arbitrary dimensions. Some properties of the
resulting operators and consequences for pure tripartite higher dimensional
states are briefly discussed.


title: Knowledge Matters: Importance of Prior Information for Optimization

abstract:
  We explore the effect of introducing prior information into the intermediate
level of neural networks for a learning task on which all the state-of-the-art
machine learning algorithms tested failed to learn. We motivate our work from
the hypothesis that humans learn such intermediate concepts from other
individuals via a form of supervision or guidance using a curriculum. The
experiments we have conducted provide positive evidence in favor of this
hypothesis. In our experiments, a two-tiered MLP architecture is trained on a
dataset with 64x64 binary inputs images, each image with three sprites. The
final task is to decide whether all the sprites are the same or one of them is
different. Sprites are pentomino tetris shapes and they are placed in an image
with different locations using scaling and rotation transformations. The first
part of the two-tiered MLP is pre-trained with intermediate-level targets being
the presence of sprites at each location, while the second part takes the
output of the first part as input and predicts the final task's target binary
event. The two-tiered MLP architecture, with a few tens of thousand examples,
was able to learn the task perfectly, whereas all other algorithms (include
unsupervised pre-training, but also traditional algorithms like SVMs, decision
trees and boosting) all perform no better than chance. We hypothesize that the
optimization difficulty involved when the intermediate pre-training is not
performed is due to the {\em composition} of two highly non-linear tasks. Our
findings are also consistent with hypotheses on cultural learning inspired by
the observations of optimization problems with deep learning, presumably
because of effective local minima.


title:
Spatially resolved star formation image and the ULX population in
  NGC2207/IC2163

abstract:
  The colliding galaxy pair NGC 2207/IC 2163, at a distance of ~39 Mpc, was
observed with Chandra, and an analysis reveals 28 well resolved X-ray sources,
including 21 ultraluminous X-ray sources (ULXs) with Lx > 10^39 erg/s, as well
as the nucleus of NGC 2207. The number of ULXs is comparable with the largest
numbers of ULXs per unit mass in any galaxy yet reported. In this paper we
report on these sources, and quantify how their locations correlate with the
local star formation rates seen in spatially-resolved star formation rate
density images that we have constructed using combinations of Galex FUV and
Spitzer 24um images. We show that the numbers of ULXs are strongly correlated
with the local star formation rate densities surrounding the sources, but that
the luminosities of these sources are not strongly correlated with star
formation rate density.


title: On the regularization process for Ariki-Koike algebras

abstract:
  The aim of this note is to study a generalization of theorems by James and
Fayers on the modular representations of the symmetric group and its Hecke
algebra to the case of the complex reflection groups of type $G(l,1,n)$ and the
associated Ariki-Koike algebra.


title: Subspaces of $L_p$ that embed into $L_p(\mu)$ with $\mu$ finite

abstract:
  Enflo and Rosenthal proved that $\ell_p(\aleph_1)$, $1 < p < 2$, does not
(isomorphically) embed into $L_p(\mu)$ with $\mu$ a finite measure. We prove
that if $X$ is a subspace of an $L_p$ space, $1< p < 2$, and $\ell_p(\aleph_1)$
does not embed into $X$, then $X$ embeds into $L_p(\mu)$ for some finite
measure $\mu$.


title:
The monochromator beamline at FLASH: performance, capabilities and
  upgrade plans

abstract:
  The monochromator beamline at the FLASH facility at DESY is the worldwide
first XUV monochromator beamline operational on a free electron laser
(FEL)source. Being a single-user machine, FLASH demands a high flexibility of
the instrumentation to fulfil the needs of diverse experiments performed by a
multidisciplinary user community. Thus, the beamline has not only been used for
high-resolution spectroscopy that it was originally designed for, but also for
pump-probe experiments controlling the temporal-spectral properties at moderate
resolution, and as a filter for high harmonics of the FEL at very low
resolution. The present performance and capabilities of the beamline are
discussed with emphasis on particularities arising from the nature of the FEL
source, and current developments are presented aiming to enhance its
capabilities for accommodating a wide variety of experiments.


title: On representation-finite algebras and beyond

abstract:
  We give a survey on the theory of representation-finite and certain minimal
representation-infinite algebras.The main goals are the existence of
multiplicative bases and of coverings with good properties. Both are attained
via ray-categories. As applications we include a proof of a sharper version of
the second Brauer-Thrall conjecture and of the fact that there are no gaps in
the lengths of the indecomposable modules over an algebra.


title: Cryptanalyzing image encryption using chaotic logistic map

abstract:
  Chaotic behavior arises from very simple non-linear dynamical equation of
logistic map which makes it was used often in designing chaotic image
encryption schemes. However, some properties of chaotic maps can also
facilitate cryptanalysis especially when they are implemented in digital
domain. Utilizing stable distribution of the chaotic states generated by
iterating the logistic map, this paper presents a typical example to show
insecurity of an image encryption scheme using chaotic logistic map. This work
will push encryption and chaos be combined in a more effective way.


title:
Regularization of propagators and logarithms in the background field
  method in 4-dimensions

abstract:
  The determinant and higher loop terms, usually treated with the Pauli-Villars
and higher covariant derivatives methods, in the background field method in 4
dimensions can hardly be regularized simultaneously. At the same time we
observe that introduction of a scalar multiplier at the quadratic form, which
is equivalent to a change of the measure in the functional integral, influences
only the determinant part of the effective action. This allows one to choose
the integration measure and the function in the regularized propagator in such
a way as to make all terms in the expansion finite.


title: Special Relativity induced by Granular Space

abstract:
  We show that the special relativistic dynamics when combined with quantum
mechanics and the concept of superstatistics can be interpreted as arising from
two interlocked non-relativistic stochastic processes that operate at different
energy scales. This interpretation leads to Feynman amplitudes that are in the
Euclidean regime identical to transition probability of a Brownian particle
propagating through a granular space. Some kind of spacetime granularity could
be held responsible for the emergence at larger scales of various symmetries.
For illustration we consider also the dynamics and the propagator of a spinless
relativistic particle. Implications for doubly special relativity, quantum
field theory, quantum gravity and cosmology are discussed.


title:
Encounter dynamics of a small target by a polymer diffusing in a
  confined domain

abstract:
  We study the first passage time for a polymer, that we call the narrow
encounter time (NETP), to reach a small target located on the surface of a
microdomain. The polymer is modeled as a Freely Joint Chain (beads connected by
springs with a resting non zero length) and we use Brownian simulations to
study two cases: when (i) any of the monomer or (ii) only one can be absorbed
at the target window. Interestingly, we find that {in the first case} the NETP
is an increasing function of the polymer length until a critical length, after
which it decreases. Moreover, in the long polymer regime, we identified an
exponential scaling law for the NETP as a function of the polymer length. {In
the second case, the position of the absorbed monomer along the polymer chain
strongly influences the NETP}. Our analysis can be applied to estimate the mean
first time of a DNA fragment to a small target in the chromatin structure or
for mRNA to find a small target.


title: Bounding the Exponent of a Verbal Subgroup

abstract:
  We deal with the following conjecture. If w is a group word and G is a finite
group in which any nilpotent subgroup generated by w-values has exponent
dividing e, then the exponent of the verbal subgroup w(G) is bounded in terms
of e and w only. We show that this is true in the case where w is either the
nth Engel word or the word [x^n,y_1,y_2,...,y_k] (Theorem A). Further, we show
that for any positive integer e there exists a number k=k(e) such that if w is
a word and G is a finite group in which any nilpotent subgroup generated by
products of k values of the word w has exponent dividing e, then the exponent
of the verbal subgroup w(G) is bounded in terms of e and w only (Theorem B).


title:
The lattice gluon propagator in Landau gauge at zero and finite
  temperature

abstract:
  The interplay between the finite volume and finite lattice spacing is
investigated using lattice QCD simulations to compute the Landau gauge gluon
propagator at zero temperature. Comparing several ensembles with different
lattice spacings and physical volumes, we conclude that the dominant effects,
in the infrared region, are associated with the use of a finite lattice
spacing. The simulations show that decreasing the lattice spacing, while
keeping the same physical volume, leads to an enhancement of the infrared gluon
propagator. Moreover, we also present results for the Landau gauge gluon
propagator at finite temperature.


title:
J/Psi production in ultraperipheral Pb+Pb and p+Pb collisions at
  energies available at the CERN Large Hadron Collider

abstract:
  We compute cross sections for incoherent and coherent diffractive J/Psi
production in ultraperipheral nucleus-nucleus and proton-nucleus collisions
using two different dipole models fitted to HERA data. We obtain a reasonably
good description of the available ALICE data for coherent J/\Psi production and
present our prediction for the incoherent cross section. We also find that
while the normalization of the cross section depends quite strongly on the
dipole model and vector meson wave function used, the rapidity dependence is
very well constrained.


title: Evolutionary Algorithms and Dynamic Programming

abstract:
  Recently, it has been proven that evolutionary algorithms produce good
results for a wide range of combinatorial optimization problems. Some of the
considered problems are tackled by evolutionary algorithms that use a
representation which enables them to construct solutions in a dynamic
programming fashion. We take a general approach and relate the construction of
such algorithms to the development of algorithms using dynamic programming
techniques. Thereby, we give general guidelines on how to develop evolutionary
algorithms that have the additional ability of carrying out dynamic programming
steps. Finally, we show that for a wide class of the so-called DP-benevolent
problems (which are known to admit FPTAS) there exists a fully polynomial-time
randomized approximation scheme based on an evolutionary algorithm.


title: Effects of Beyond Standard Model Physics on GRB Neutrinos

abstract:
  The nondetection of neutrinos coming from Gamma Ray Bursts (GRBs) by the
IceCube experiment has raised serious questions on our understanding of GRB's
and the mechanism of neutrino flux production in them. Motivated by this and
the need for a precise calculation for GRB neutrino flux, here we study the
effects of beyond standard model physics on the GRB neutrino flux. In the
internal shock model of GRB, high energy neutrinos are expected from muon, pion
and kaon decays. Using the latest best fit neutrino oscillation parameters, we
compute the expected flux on earth for standard as well as non-standard
oscillation scenarios. Among the non-standard scenarios, we consider neutrino
decay, pseudo-dirac nature of neutrinos and presence of one eV scale light
sterile neutrino. Incorporating other experimental bounds on these new physics
scenarios, we show that neutrino decay scenario can significantly alter the
neutrino flux on earth from the expected ones whereas the corresponding changes
for pseudo-dirac and sterile neutrino cases are moderate.


title: Iwahori-Matsumoto involution and linear Koszul Duality

abstract:
  We use linear Koszul duality, a geometric version of the standard duality
between modules over symmetric and exterior algebras studied in previous papers
of the authors to give a geometric realization of the Iwahori-Matsumoto
involution of affine Hecke algebras. More generally we prove that linear Koszul
duality is compatible with convolution in a general context related to
convolution algebras.


title:
Ciliary contact interactions dominate surface scattering of swimming
  eukaryotes

abstract:
  Interactions between swimming cells and surfaces are essential to many
microbiological processes, from bacterial biofilm formation to human
fertilization. However, in spite of their fundamental importance, relatively
little is known about the physical mechanisms that govern the scattering of
flagellated or ciliated cells from solid surfaces. A more detailed
understanding of these interactions promises not only new biological insights
into structure and dynamics of flagella and cilia, but may also lead to new
microfluidic techniques for controlling cell motility and microbial locomotion,
with potential applications ranging from diagnostic tools to therapeutic
protein synthesis and photosynthetic biofuel production. Due to fundamental
differences in physiology and swimming strategies, it is an open question
whether microfluidic transport and rectification schemes that have recently
been demonstrated for pusher-type microswimmers such as bacteria and sperm
cells, can be transferred to puller-type algae and other motile eukaryotes, as
it is not known whether long-range hydrodynamic or short-range mechanical
forces dominate the surface interactions of these microorganisms. Here, using
high-speed microscopic imaging, we present direct experimental evidence that
the surface scattering of both mammalian sperm cells and unicellular green
algae is primarily governed by direct ciliary contact interactions. Building on
this insight, we predict and verify experimentally the existence of optimal
microfluidic ratchets that maximize rectification of initially uniform
Chlamydomonas reinhardtii suspensions. Since mechano-elastic properties of
cilia are conserved across eukaryotic species, we expect that our results apply
to a wide range of swimming microorganisms.


title:
Does the Oosterhoff Dichotomy Exist in The Andromeda Galaxy? I. The case
  of G11

abstract:
  We present the first evidence that Oosterhoff type II globular clusters exist
in the Andromeda galaxy (M31). On the basis of time-series photometry of the
moderately metal-poor ([Fe/H]\sim -1.6 dex) M31 globular cluster G11, obtained
with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope, we
detected and derived periods for 14 RR Lyrae stars, of which five are found to
lie inside the cluster tidal radius. They include three fundamental-mode (RRab)
and two first-overtone (RRc) pulsators, with average periods <Pab> = 0.70 d,
and <Pc> = 0.40 d, respectively. These mean periods and the position of the
cluster variable stars in the period-amplitude and period-metallicity diagrams,
all suggest that G11 is likely to be an Oosterhoff type II globular cluster.
This appears to be in agreement with the general behavior of Milky Way globular
clusters with similar metallicity and horizontal branch morphology.


title: A Poincar\'{e} Lemma for Whitney-de Rham complex

abstract:
  Let $M$ be a real analytic manifold, $Z$ a closed subanalytic subset of $M$.
We show that the Whitney-de Rham complex over $Z$ is quasi-isomorphic to the
constant sheaf $\mathbb{C}_{Z}$


title: Algebraization, transcendence, and D-group schemes

abstract:
  We present a conjecture in Diophantine geometry concerning the construction
of line bundles over smooth projective varieties over $\bar{\mathbb Q}}$. This
conjecture, closely related to the Grothendieck Period Conjecture for cycles of
codimension 1, is also motivated by classical algebraization results in
analytic and formal geometry and in transcendence theory. Its formulation
involves the consideration of $D$-group schemes attached to abelian schemes
over algebraic curves over $\bar{\mathbb Q}}$. We also derive the Grothendieck
Period Conjecture for cycles of codimension 1 in abelian varieties over
$\bar{\mathbb Q}}$ from a classical transcendence theorem \`a la
Schneider-Lang.


title:
Stochastic Quantization Approach for Causal Dynamical Triangulation
  String Field Theory

abstract:
  We construct a 2-dimensional Causal Dynamical Triangulation (CDT) model from
a matrix model which represents the loop gas model of closed string. The
target-space index is reinterpreted as time or geodesic distance. We apply
stochastic quantization method to the model to obtain the Generalized CDT
(GCDT), which has additional interaction of creating baby universe. If we take
a specific scaling in continuum limit, we realize an extended GCDT model
characterized by the non-critical string field theory.


title: Constraints on mass loss of globular clusters in dwarf galaxies

abstract:
  The Fornax dwarf spheroidal galaxy is well known for its very high globular
cluster specific frequency, SN=26. Furthermore, while the field star
metallicity distribution peaks at [Fe/H]=-1, four of the five GCs have
[Fe/H]<-2. Only about 5 percent of the field stars have such low metallicities.
Hence, a very large fraction of about 1/5-1/4 of the most metal-poor stars
belong to the four most metal-poor GCs. This implies that these clusters could,
at most, have been a factor of 4-5 more massive initially. A second, even more
extreme case may be the IKN dwarf galaxy where SN=124. Although metallicities
are not accurately known, the GCs account for about 13 percent of the total
V-band luminosity of IKN.


title:
Continuous dependence estimates for the ergodic problem of Bellman
  equation with an application to the rate of convergence for the
  homogenization problem

abstract:
  This paper is devoted to establish continuous dependence estimates for the
ergodic problem for Bellman operators (namely, estimates of (v_1-v_2) where v_1
and v_2 solve two equations with different coefficients). We shall obtain an
estimate of ||v_1-v_2||_\infty with an explicit dependence on the
L^\infty-distance between the coefficients and an explicit characterization of
the constants and also, under some regularity conditions, an estimate of
||v_1-v_2||_{C^2(\R^n)}.
  Afterwards, the former result will be crucial in the estimate of the rate of
convergence for the homogenization of Bellman equations. In some regular cases,
we shall obtain the same rate of convergence established in the monographs
[11,26] for regular linear problems.


title: Graphene Transfer with Reduced Residue

abstract:
  We present a new transfer procedure for graphene using acetic acid, which
removes the residue that is common in standard acetone treatments.
Post-transfer samples cleaned with acetic acid and acetone were characterized
using Raman spectroscopy and atomic force microscopy for comparison. We further
illustrate the quality of our transfer process by using fluorescence quenching
to create an optical map of surface contaminants.


title: Single-shot Sub-Rayleigh Imaging with Sparse Detection

abstract:
  For conventional imaging, the imaging resolution limit is given by the
Rayleigh criterion. Exploiting the prior knowledge of imaging object's sparsity
and fixed optical system, imaging beyond the conventional Rayleigh limit, which
is backed up by numerical simulation and experiments, is achieved by
illuminating the object with single-shot thermal light and detecting the
object's information at the imaging plane with some sparse-array single-pixel
detectors. The quality of sub-Rayleigh imaging with sparse detection is also
shown to be related to the effective number of single-pixel detectors and the
detection signal-to-noise ratio at the imaging plane.


title:
Time dependence of the proton flux measured by PAMELA during the July
  2006 - December 2009 solar minimum

abstract:
  The energy spectra of galactic cosmic rays carry fundamental information
regarding their origin and propagation. These spectra, when measured near
Earth, are significantly affected by the solar magnetic field. A comprehensive
description of the cosmic radiation must therefore include the transport and
modulation of cosmic rays inside the heliosphere. During the end of the last
decade the Sun underwent a peculiarly long quiet phase well suited to study
modulation processes. In this paper we present proton spectra measured from
July 2006 to December 2009 by PAMELA. The large collected statistics of protons
allowed the time variation to be followed on a nearly monthly basis down to 400
MV. Data are compared with a state-of-the-art three-dimensional model of solar
modulation.


title: The RMS Survey: Near-IR Spectroscopy of Massive Young Stellar Objects

abstract:
  Near-infrared H- and K-band spectra are presented for 247 objects, selected
from the Red MSX Source (RMS) survey as potential young stellar objects (YSOs).
195 (~80%) of the targets are YSOs, of which 131 are massive YSOs (L_BOL >
5x10^3 L_solar), M > 8M_solar. This is the largest spectroscopic study of
massive YSOs to date, providing a valuable resource for the study of massive
star formation. In this paper we present our exploratory analysis of the data.
The YSOs observed have a wide range of embeddedness (2.7 < A_V < 114),
demonstrating that this study covers minimally obscured objects right through
to very red, dusty sources. Almost all YSOs show some evidence for emission
lines, though there is a wide variety of observed properties. The most commonly
detected lines are Brgamma, H_2, fluorescent FeII, CO bandhead, [FeII] and HeI
2-1 2^1S-2^1P, in order of frequency of occurrence. In total, ~40% of the YSOs
display either fluorescent FeII 1.6878um or CO bandhead emission (or both),
indicative of a circumstellar disc; however, no correlation of the strength of
these lines with bolometric luminosity was found. We also find that ~60% of the
sources exhibit [FeII] or H_2 emission, indicating the presence of an outflow.
Three quarters of all sources have Brgamma in emission. A good correlation with
bolometric luminosity was observed for both the Brgamma and H_2 emission line
strengths, covering 1 L_solar< L_BOL < 3.5x10^5 L_solar. This suggests that the
emission mechanism for these lines is the same for low-, intermediate-, and
high-mass YSOs, i.e. high-mass YSOs appear to resemble scaled-up versions of
low-mass YSOs.


title:
Note on the hydrodynamic description of thin nematic films: strong
  anchoring model

abstract:
  We discuss the long-wave hydrodynamic model for a thin film of nematic liquid
crystal in the limit of strong anchoring at the free surface and at the
substrate. We rigorously clarify how the elastic energy enters the evolution
equation for the film thickness in order to provide a solid basis for further
investigation: several conflicting models exist in the literature that predict
qualitatively different behaviour. We consolidate the various approaches and
show that the long-wave model derived through an asymptotic expansion of the
full nemato-hydrodynamic equations with consistent boundary conditions agrees
with the model one obtains by employing a thermodynamically motivated gradient
dynamics formulation based on an underlying free energy functional. As a
result, we find that in the case of strong anchoring the elastic distortion
energy is always stabilising. To support the discussion in the main part of the
paper, an appendix gives the full derivation of the evolution equation for the
film thickness via asymptotic expansion.


title: Spin-wave excitations in presence of nanoclusters of magnetic impurities

abstract:
  Nanoscale inhomogeneities and impurity clustering are often found to
drastically affect the magnetic and transport properties in disordered/diluted
systems, giving rise to rich and complex phenomena. However, the physics of
these systems still remains to be explored in more details as can be seen from
the scarce literature available. We present a detailed theoretical analysis of
the effects of nanoscale inhomogeneities on the spin excitation spectrum in
diluted magnetic systems. The calculations are performed on relatively large
systems (up to $N$=$66^3$). It is found that even low concentrations of
inhomogeneities have drastic effects on both the magnon density of states and
magnon excitations. These effects become even more pronounced in the case of
short ranged magnetic interactions between the impurities. In contrast to the
increase of critical temperatures $T_C$, reported in previous studies, the
spin-stiffness $D$ is systematically suppressed in the presence of nanoscale
inhomogeneities. Moreover $D$ is found to strongly depend on the
inhomogeneities' concentration, the cluster size, as well as the range of the
magnetic interactions. The findings are discussed in the prospect of potential
spintronics applications. We believe that this detailed numerical work could
initiate future experimental studies to probe this rich physics with the most
appropriate tool, Inelastic Neutron Scattering (INS).


title: Role of the Ionic Potential in High Harmonic Generation

abstract:
  Recollision processes provide direct insight into the structure and dynamics
of electronic wave functions. However, the strength of the process sets its
basic limitations - the interaction couples numerous degrees of freedom. In
this Letter we decouple the basic steps of the process and resolve the role of
the ionic potential which is at the heart of a broad range of strong field
phenomena. Specifically, we measure high harmonic generation from argon atoms.
By manipulating the polarization of the laser field we resolve the vectorial
properties of the interaction. Our study shows that the ionic core plays a
significant role in all steps of the interaction. In particular, Coulomb
focusing induces an angular deflection of the electrons before recombination. A
complete spatiospectral analysis reveals the influence of the potential on the
spatiotemporal properties of the emitted light.


title:
Electrically Tunable Topological State in [111] Perovskite Materials
  with Antiferromagnetic Exchange Field

abstract:
  A topological state with simultaneous nonzero Chern number and spin Chern
number is possible for electrons on honeycomb lattice based on band engineering
by staggered electric potential and antiferromagnetic exchange field in
presence of intrinsic spin-orbit coupling. With first principles calculation we
confirm that the scheme can be realized by material modification in perovskite
G-type antiferromagnetic insulators grown along [111] direction, where d
electrons hop on a single buckled honeycomb lattice. This material is ideal for
spintronics applications, since it provides a spin-polarized quantized edge
current, robust to both nonmagnetic and magnetic defects, with the spin
polarization tunable by inverting electric field.


title:
Calibration and improved prediction of computer models by universal
  Kriging

abstract:
  This paper addresses the use of experimental data for calibrating a computer
model and improving its predictions of the underlying physical system. A global
statistical approach is proposed in which the bias between the computer model
and the physical system is modeled as a realization of a Gaussian process. The
application of classical statistical inference to this statistical model yields
a rigorous method for calibrating the computer model and for adding to its
predictions a statistical correction based on experimental data. This
statistical correction can substantially improve the calibrated computer model
for predicting the physical system on new experimental conditions. Furthermore,
a quantification of the uncertainty of this prediction is provided. Physical
expertise on the calibration parameters can also be taken into account in a
Bayesian framework. Finally, the method is applied to the thermal-hydraulic
code FLICA 4, in a single phase friction model framework. It allows to improve
the predictions of the thermal-hydraulic code FLICA 4 significantly.


title:
Deep-Subwavelength Spatial Characterization of Angular Emission from
  Single-Crystal Au Plasmonic Ridge Nanoantennas

abstract:
  We use spatially and angle-resolved cathodoluminescence imaging spectroscopy
to study, with deep subwavelength resolution, the radiation mechanism of single
plasmonic ridge antennas with lengths ranging from 100 to 2000 nm. We measure
the antenna's standing wave resonances up to the fifth order and measure the
dispersion of the strongly confined guided plasmon mode. By directly detecting
the emitted antenna radiation with a 2D CCD camera we are able to measure the
angular emission patterns associated with each individual antenna resonance. We
demonstrate that the shortest ridges can be modeled as a single point dipole
emitter oriented either upward (m=0) or in-plane (m=1). The far-field emission
pattern for longer antennas (m>2) is well described by two interfering in-plane
point dipoles at the end facets giving rise to an angular fringe pattern, where
the number of fringes increases as the antenna becomes longer. Taking advantage
of the deep subwavelength excitation resolution of the cathodoluminescence
technique, we are able to determine the antenna radiation pattern as function
of excitation position. By including the phase of the radiating dipoles into
our simple dipole model we completely reproduce this effect. This work
demonstrates how angle-resolved cathodoluminescence spectroscopy can be used to
fully determine the emission properties of subwavelength ridge antennas, which
ultimately can be used for the design of more complex and efficient antenna
structures.


title: Integral Points on Elliptic Curves and the Bombieri-Pila Bounds

abstract:
  Let C be an affine, plane, algebraic curve of degree d with integer
coefficients. In 1989, Bombieri and Pila showed that if one takes a box with
sides of length N then C can obtain no more than
O_{d,\epsilon}(N^{1/d+\epsilon}) integer points within the box. Importantly,
the implied constant makes no reference to the coefficients of the curve.
Examples of certain rational curves show that this bound is tight but it has
long been thought that when restricted to non-rational curves an improvement
should be possible whilst maintaining the uniformity of the bound. In this
paper we consider this problem restricted to elliptic curves and show that for
a large family of these curves the Bombieri-Pila bounds can be improved. The
techniques involved include repulsion of integer points, the theory of heights
and the large sieve. As an application we prove a uniform bound for the number
of rational points of bounded height on a general del Pezzo surface of degree
1.


title:
Another look at expurgated bounds and their statistical-mechanical
  interpretation

abstract:
  We revisit the derivation of expurgated error exponents using a method of
type class enumeration, which is inspired by statistical-mechanical methods,
and which has already been used in the derivation of random coding exponents in
several other scenarios. We compare our version of the expurgated bound to both
the one by Gallager and the one by Csiszar, Korner and Marton (CKM). For
expurgated ensembles of fixed composition codes over finite alphabets, our
basic expurgated bound coincides with the CKM expurgated bound, which is in
general tighter than Gallager's bound, but with equality for the optimum type
class of codewords. Our method, however, extends beyond fixed composition codes
and beyond finite alphabets, where it is natural to impose input constraints
(e.g., power limitation). In such cases, the CKM expurgated bound may not apply
directly, and our bound is in general tighter than Gallager's bound. In
addition, while both the CKM and the Gallager expurgated bounds are based on
Bhattacharyya bound for bounding the pairwise error probabilities, our bound
allows the more general Chernoff distance measure, thus giving rise to
additional improvement using the Chernoff parameter as a degree of freedom to
be optimized.


title: Hydrodynamic modes in a confined granular fluid

abstract:
  Confined granular fluids, placed in a shallow box that is vibrated
vertically, can achieve homogeneous stationary states thanks to energy
injection mechanisms that take place throughout the system. These states can be
stable even at high densities and inelasticities allowing for a detailed
analysis of the hydrodynamic modes that govern the dynamics of granular fluids.
Analyzing the decay of the time correlation functions it is shown that there is
a crossover between a quasielastic regime in which energy evolves as a slow
mode, to a inelastic regime, with energy slaved to the other conserved fields.
The two regimes have well differentiated transport properties and, in the
inelastic regime, the dynamics can be described by a reduced hydrodynamics with
modified longitudinal viscosity and sound speed. The crossover between the two
regimes takes place at a wavevector that is proportional to the inelasticity. A
two dimensional granular model, with collisions that mimic the energy transfers
that take place in a confined system is studied by means of microscopic
simulations. The results show excellent agreement with the theoretical
framework and allows the validation of hydrodynamic-like models.


title:
Fermi edge polaritons in a highly degenerate 2D electron gas: a
  diagrammatic theory

abstract:
  We present a theoretical study on polaritons in highly doped semiconductor
microcavities. In particular, we focus on a cavity mode that is resonant with
the absorption threshold (`Fermi edge'). In agreement with experimental
results, the strong light-matter coupling is maintained under very high doping
within our ladder diagram approximation. While the lower polariton is
qualitatively unaltered, it acquires a finite lifetime due to relaxation of the
valence band hole if the electron density exceeds a certain critical value. On
the other hand the upper polariton has a finite lifetime for all densities,
because it lies in the electron-hole continuum where no bound state exists. Our
calculations show that a narrow upper polariton quasiparticle still exists as a
result from the interplay between light-matter coupling and final state Coulomb
interaction.


title:
Critical exponents and irreversibility lines of
  La$_{0.9}$Sr$_{0.1}$CoO$_3$ single crystal

abstract:
  We have studied the dynamic and static critical behavior of spin glass
transition in insulating La$_{0.9}$Sr$_{0.1}$CoO$_3$ single crystal by ac
susceptibility and dc magnetization measurements in the vicinity of its
freezing temperature ($T_f$). The dynamic scaling analysis of the frequency
dependence of ac susceptibility data yields the characteristic time constant
$\tau_{0}$=1.6(9)$\times10^{-12}$ s, the dynamic critical exponent
$z\nu$=9.5(2), and a frequency dependence factor
$K$=$\Delta$$T_{f}/T_{f}$($\Delta$$log$$f$)=0.017, indicating that the sample
enters into a canonical spin-glass phase below $T_{f}$=34.8(2) K. The scaling
analysis of non-linear magnetization in the vicinity of $T_{f}$ through the
static scaling hypothesis yields critical exponents $\beta$=0.89(1) and
$\gamma$=2.9(1), which match well with that observed for well known
three-dimensional (3D) Heisenberg spin glasses. From the longitudinal component
of zero-field-cooled and field-cooled magnetization measurement we have
constructed the $H-T$ phase diagram which represents the field evolution of two
characteristic temperatures: the upper one, $T_{w}(H)$, indicates the onset of
spin freezing in a uniform external field $H$, while the lower one, $T_{s}(H)$,
marks the onset of strong irreversibility of the frozen state. The low field
$T_{s}(H)$ follows the critical line suggested by d'Almeida-Thouless model for
canonical spin glass, whereas the $T_{w}(H)$ exhibits a reentrant behavior with
a maximum in the $T_{w}(H)$ at a nonzero field above which it follows the
Gabay-Toulouse (GT) critical line which is a characteristic of Heisenberg spin
glass. The re-entrant behavior of the GT line resembles that predicted
theoretically for $n$-component vector spin glasses in the presence of a
uniaxial anisotropy field.


title: An algebraic formulation of the graph reconstruction conjecture

abstract:
  The graph reconstruction conjecture asserts that every finite simple graph on
at least three vertices can be reconstructed up to isomorphism from its deck -
the collection of its vertex-deleted subgraphs. Kocay's Lemma is an important
tool in graph reconstruction. Roughly speaking, given the deck of a graph $G$
and any finite sequence of graphs, it gives a linear constraint that every
reconstruction of $G$ must satisfy.
  Let $\psi(n)$ be the number of distinct (mutually non-isomorphic) graphs on
$n$ vertices, and let $d(n)$ be the number of distinct decks that can be
constructed from these graphs. Then the difference $\psi(n) - d(n)$ measures
how many graphs cannot be reconstructed from their decks. In particular, the
graph reconstruction conjecture is true for $n$-vertex graphs if and only if
$\psi(n) = d(n)$.
  We give a framework based on Kocay's lemma to study this discrepancy. We
prove that if $M$ is a matrix of covering numbers of graphs by sequences of
graphs, then $d(n) \geq \mathsf{rank}_\mathbb{R}(M)$. In particular, all
$n$-vertex graphs are reconstructible if one such matrix has rank $\psi(n)$. To
complement this result, we prove that it is possible to choose a family of
sequences of graphs such that the corresponding matrix $M$ of covering numbers
satisfies $d(n) = \mathsf{rank}_\mathbb{R}(M)$.


title: Dirac prescription from BRST symmetry in FRW space-time

abstract:
  A procedure to define the BRST charge from the Noether one in extended phase
space is given. It is outlined how this prescription can be applied to a
Friedmann-Robertson-Walker space-time with a differential gauge condition and
it allows us to reproduce the results of [19]. Then we discuss the
cohomological classes associated with functions in extended phase space having
ghost number one and we recover the frozen formalism for classical observables.
Finally, we consider the quantization of BRST-closed states and we define a
scalar product which implements the superHamiltonian constraint.