title: Boron aggregation in the ground states of boron-carbon fullerenes

abstract:
  We present novel structural motifs for boron-carbon nano-cages of the
stochiometries B12C48 and B12C50, based on first principle calculations. These
configurations are distinct from those proposed so far by the fact that the
boron atoms are not isolated and distributed over the entire surface of the
cages, but rather aggregate at one location to form a patch. Our putative
ground state of B12C48 is 1.8 eV lower in energy than the previously proposed
ground state and violates all the suggested empirical rules for constructing
low energy fullerenes. The B12C50 configuration is energetically even more
favorable than B12C48, showing that structures derived from the C60
Buckminsterfullerene are not necessarily magic sizes for heterofullerenes.


title:
Gradient bounds and rigidity results for singular, degenerate,
  anisotropic partial differential equations

abstract:
  We consider the Wulff-type energy functional $$ \mathcal{W}_\Omega(u) :=
\int_\Omega B(H(\nabla u (x))) - F(u(x)) \, dx, $$ where $B$ is positive,
monotone and convex, and $H$ is positive homogeneous of degree 1. The critical
points of this functional satisfy a possibly singular or degenerate,
quasilinear equation in an anisotropic medium. We prove that the gradient of
the solution is bounded at any point by the potential $F(u)$ and we deduce
several rigidity and symmetry properties.


title: Crossed products of Banach algebras. II

abstract:
  In earlier work a crossed product of a Banach algebra was constructed from a
Banach algebra dynamical system $(A,G,\alpha)$ and a class $\mathcal{R}$ of
continuous covariant representations, and its representations were determined.
In this paper the theory is developed further. We consider the dependence of
the crossed product on the class $\mathcal{R}$ and its essential uniqueness.
Next we study generalized Beurling algebras: weighted Bochner spaces of
$A$-valued functions on $G$ with a continuous multiplication. Though not Banach
algebras in general, they are isomorphic to a crossed product of a Banach
algebra, and the earlier work therefore predicts the structure of their
representations. Classical results for the usual Beurling (Banach) algebras of
scalar valued functions are then retrieved as special cases. We also show how,
e.g., an anti-covariant pair of anti-representations of $A$ and $G$ can be
viewed as a covariant pair for a related Banach algebra dynamical system, so
that the earlier work becomes applicable to classes of such other pairs. After
including material on the representations of the projective tensor product of
Banach algebras, we combine this idea with the results already obtained and
describe the two-sided modules over the generalized Beurling algebras, where
again specializing to the scalars gives a classical result.


title: Entanglement, Nonlocality, Superluminal Signaling and Cloning

abstract:
  The paper is a Chapter of a book. In it an exhaustive review of the proposals
to send faster than light signals resorting to quantum nonlocality and the
reduction process is presented, together with a critical analysis and rebuttal
of all proposals. The most interesting part of the Chapter is the one in which
the problem of quantum cloning is discussed. Actually, a proposal of
superluminal signaling based on an hypothetical cloning machine has been
presented by N. Herbert. The proposal does not work just because of the
assumption that one can clone nonorthogonal states. The fact that such a
machine is incompatible with quantum theory (i.e., the so-called No-Cloning
Theorem) has been proved, for the first time, by the author of the present
chapter in his referee's report to Herbert's paper. In the final part of the
paper some recent (different but similarly not correct) proposals are analyzed
and the reasons for which they are basically wrong are presented.


title:
Cookies Invading Our Privacy for Marketing Advertising and Security
  Issues

abstract:
  Privacy has been a major concern for everybody over the internet. Governments
across the globe have given their views on how the internet space can be
managed effectively so that there is some control on the flow of confidential
information and privacy to users and as well as to data is achieved. Taking
advantage of the lack of one unified body that could govern the online space
with its strict and stringent rules certain websites use the text files called
cookies in collecting data from users and using them for marketing them in
advertisements networks and third party websites with the help of JavaScript
and flash technologies. Even before many of us think what is happening around
us in the online usage we are being invaded by the cookies and are targeted
with their specific information that could tempt us to buy a product or service
to which we were longing for in the recent past. Though it may be argued its a
kind of marketing strategy to give the customer what he wants but it can no way
be something like the user is just being targeted because he has already shown
interest in something and he should be disturbed until he gets hold of
something. Its purely a security breach as most of the websites dont ask
permission for the usage of cookies and setting them into the users browser and
the most important thing is no privacy statement is issued that the information
is used for targeted marketing. This analysis paper has views from different
sources, an example of such an activity that is a potential security breach and
various other information of what these sites do to use the deadly cookies for
commercial tricks.


title:
Tent spaces over metric measure spaces under doubling and related
  assumptions

abstract:
  In this article, we define the Coifman-Meyer-Stein tent spaces
$T^{p,q,\alpha}(X)$ associated with an arbitrary metric measure space
$(X,d,\mu)$ under minimal geometric assumptions. While gradually strengthening
our geometric assumptions, we prove duality, interpolation, and change of
aperture theorems for the tent spaces. Because of the inherent technicalities
in dealing with abstract metric measure spaces, most proofs are presented in
full detail.


title: Exchange Bias driven by Dzyaloshinskii-Moriya interactions

abstract:
  The exchange bias effect in compensated IrMn3/Co(111) system is studied using
multiscale modeling from "ab initio" to atomistic calculations. We evaluate
numerically the out-of-plane hysteresis loops of the bi-layer for different
thickness of the ferromagnetic layer. The results show the existence of a
perpendicular exchange bias field and an enhancement of the coercivity of the
system. In order to elucidate the possible origin of the exchange bias, we
analyze the hysteresis loops of a selected bi-layer by tuning the different
contributions to the exchange interactions across the interface. Our results
indicate that the exchange bias is primarily induced by the
Dzyaloshinskii-Moriya interactions, while the coercivity is increased mainly
due to a spin-flop mechanism.


title: Enhanced photocurrent readout for a quantum dot qubit by bias modulation

abstract:
  We demonstrate coherent control of a quantum dot exciton using photocurrent
detection with a sinusoidal reverse bias. Optical control is performed at low
bias, where tunneling-limited coherence times are long. Following this step,
the tunneling rates are increased to remove the long-lived hole, achieving a
high photocurrent signal. For a detection efficiency of 68%, electron and hole
tunneling times during optical control of 200 ps and 20 ns can be achieved,
compared to 120 ps and 7 ns for the constant bias case, respectively.


title: Rigid objects, triangulated subfactors and abelian localizations

abstract:
  We study abelian localizations of triangulated categories induced by rigid
contravariantly finite subcategories, and also triangulated structures on
subfactor categories of triangulated categories. In this context we generalize
recent results of Buan-Marsh and Iyama-Yoshino. We also extend basic results of
Keller-Reiten concerning the Gorenstein and the Calabi-Yau property for
categories arising from certain rigid, not necessarily cluster tilting,
subcategories, as well as several results of the literature concerning the
connections between 2-cluster tilting subcategories of triangulated categories
and tilting subcategories of the associated abelian category of coherent
functors. Finally we characterize 2-cluster tilting subcategories along these
lines.


title: On algebras of finite Cohen-Macaulay type

abstract:
  We study Artin algebras $A$ and commutative Noetherian complete local rings
$R$ in connection with the following decomposition property of
Gorenstein-projective modules: $(*)$ any Gorenstein-projective module is a
direct sum of finitely generated modules. We show that this direct
decomposition property is related to the property of the algebra $A$, or the
ring $R$, being (virtually) Gorenstein of finite Cohen-Macaquly type. Along the
way we generalize classical results of Auslander and Ringel-Tachikawa from the
early seventies, and results of Chen and Yoshino on the structure of
Gorenstein-projective modules. Finally we study homological properties of
(stable) relative Auslander algebras of virtually Gorenstein algebras of finite
Cohen-Macaulay type and, under the presence of a cluster-tilting object, we
give descriptions of the stable category of Gorenstein-projective modules in
terms of suitable cluster categories.


title:
Characterization of ellipsoids through an overdetermined boundary value
  problem of Monge-Amp\`ere type

abstract:
  The study of the optimal constant in an Hessian-type Sobolev inequality leads
to a fully nonlinear boundary value problem, overdetermined with non standard
boundary conditions. We show that all the solutions have ellipsoidal symmetry.
In the proof we use the maximum principle applied to a suitable auxiliary
function in conjunction with an entropy estimate from affine curvature flow.


title:
Accelerated Thermalisation of 39K atoms in a Magnetic Trap with
  Superimposed Optical Potential

abstract:
  We report the rapid accelerated thermalisation of Potassium 39 K atoms loaded
in a magnetic trap, in the presence of a single dipole trap beam. More than an
order of magnitude reduction in the thermalisation time, to less than a second,
is observed with the focused off- resonant beam occupying only 0.01% of the
volume of the magnetic trap. The cold atoms are loaded from a Magneto-Optical
Trap(MOT) of 39 K that has gone through a compressed MOT and sub-Doppler
cooling stage. The atoms are prepared in the magnetically stretched |F = 2, mF
= 2> state prior to loading into the hybrid trap. We also report a direct
loading of 39 K atoms, prepared in the state |F = 1>, into a single beam dipole
trap.


title: Effects of spacetime anisotropy on the galaxy rotation curves

abstract:
  The observations on galaxy rotation curves show significant discrepancies
from the Newtonian theory. This issue could be explained by the effect of the
anisotropy of the spacetime. Conversely, the spacetime anisotropy could also be
constrained by the galaxy rotation curves. Finsler geometry is a kind of
intrinsically anisotropic geometry. In this paper, we study the effect of the
spacetime anisotropy at the galactic scales in the Finsler spacetime. It is
found that the Finslerian model has close relations with the Milgrom's MOND. By
performing the best-fit procedure to the galaxy rotation curves, we find that
the anisotropic effects of the spacetime become significant when the Newtonian
acceleration \(GM/r^2\) is smaller than the critical acceleration \(a_0\).
Interestingly, the critical acceleration \(a_0\), although varies between
different galaxies, is in the order of magnitude \(cH_0/2\pi\sim 10^{-10}
\rm{m\,\, s^{-2}}\).


title:
Quasi-hereditary algebras, exact Borel subalgebras,
  A-infinity-categories and boxes

abstract:
  Highest weight categories arising in Lie theory are known to be associated
with finite dimensional quasi-hereditary algebras such as Schur algebras or
blocks of category $\mathcal O$. An analogue of the PBW theorem will be shown
to hold for quasi-hereditary algebras: Up to Morita equivalence each such
algebra has an exact Borel subalgebra. The category $\mathcal{F}(\Delta)$ of
modules with standard (Verma, Weyl, \dots) filtration, which is exact, but
rarely abelian, will be shown to be equivalent to the category of
representations of a directed box. This box is constructed as a quotient of a
dg algebra associated with the $A_{\infty}$-structure on $\mathcal{F}(\Delta)$.
Its underlying algebra is an exact Borel subalgebra.


title:
Bound states of the spin-orbit coupled ultracold atom in a
  one-dimensional short-range potential

abstract:
  We solve the bound state problem for the Hamiltonian with the spin-orbit and
the Raman coupling included. The Hamiltonian is perturbed by a one-dimensional
short-range potential V which describes the impurity scattering. In addition to
the bound states obtained by considering weak solutions through the Fourier
transform or by solving the eigenvalue equation on a suitable domain directly,
it is shown that ordinary point-interaction representations of V lead to
spin-orbit induced extra states.

categories: math-ph cond-mat.quant-gas math.MP quant-ph


title: Theory of superconductivity in a three-orbital model of Sr$_2$RuO$_4$

abstract:
  In conventional and high transition temperature copper oxide and iron
pnictide superconductors, the Cooper pairs all have even parity. As a rare
exception, Sr$_2$RuO$_4$ is the first prime candidate for topological chiral
p-wave superconductivity, which has time-reversal breaking odd-parity Cooper
pairs known to exist before only in the neutral superfluid $^3$He. However,
there are several key unresolved issues hampering the microscopic description
of the unconventional superconductivity. Spin fluctuations at both large and
small wavevectors are present in experiments, but how they arise and drive
superconductivity is not yet clear. Spontaneous edge current is expected but
not observed conclusively. Specific experiments point to highly band- and/or
momentum-dependent energy gaps for quasiparticle excitations in the
superconducting state. Here, by comprehensive functional renormalization group
calculations with all relevant bands, we disentangle the various competing
possibilities. In particular we show the small wavevector spin fluctuations,
driven by a single two-dimensional band, trigger p-wave superconductivity with
quasi-nodal energy gaps.


title: New search for correlated e+e- pairs in the alpha decay of 241Am

abstract:
  A new search for production of correlated e+e- pairs in the alpha decay of
241Am has been carried out deep underground at the Gran Sasso National
Laboratory of the I.N.F.N. by using pairs of NaI(Tl) detectors of the
DAMA/LIBRA set-up. The experimental data show an excess of double coincidences
of events with energy around 511 keV in faced pairs of detectors, which are not
explained by known side reactions. This measured excess gives a relative
activity lambda = (4.70 \pm 0.63) \times 10^{-9} for the Internal Pair
Production (IPP) with respect to alpha decay of 241Am; this value is of the
same order of magnitude as previous determinations. In a conservative approach
the upper limit lambda < 5.5 \times 10^{-9} (90% C.L.) can be derived. It is
worth noting that this is the first result on IPP obtained in an underground
experiment, and that the lambda value obtained in the present work is
independent on the live-time estimate.


title:
Experiences of Using a Hybrid Cloud to Construct an Environmental
  Virtual Observatory

abstract:
  Environmental science is often fragmented: data is collected using mismatched
formats and conventions, and models are misaligned and run in isolation. Cloud
computing offers a lot of potential in the way of resolving such issues by
supporting data from different sources and at various scales, by facilitating
the integration of models to create more sophisticated software services, and
by providing a sustainable source of suitable computational and storage
resources. In this paper, we highlight some of our experiences in building the
Environmental Virtual Observatory pilot (EVOp), a tailored cloud-based
infrastructure and associated web-based tools designed to enable users from
different backgrounds to access data concerning different environmental issues.
We review our architecture design, the current deployment and prototypes. We
also reflect on lessons learned. We believe that such experiences are of
benefit to other scientific communities looking to assemble virtual
observatories or similar virtual research environments.


title: Quantum Reflection as a New Signature of Quantum Vacuum Nonlinearity

abstract:
  We show that photons subject to a spatially inhomogeneous electromagnetic
field can experience quantum reflection. Based on this observation, we propose
quantum reflection as a novel means to probe the nonlinearity of the quantum
vacuum in the presence of strong electromagnetic fields.


title: Type-Decomposition of a Synaptic Algebra

abstract:
  A synaptic algebra is a generalization of the self-adjoint part of a von
Neumann algebra. In this article we extend to synaptic algebras the
type-I/II/III decomposition of von Neumann algebras, AW*-algebras, and
JW-algebras.


title:
Simulation of a typical house in the region of Antananarivo, Madagascar.
  Determination of passive solutions using local materials

abstract:
  This paper deals with new proposals for the design of passive solutions
adapted to the climate of the highlands of Madagascar. While the strongest
population density is located in the central highlands, the problem of thermal
comfort in buildings occurs mainly during winter time. Currently, people use
raw wood to warm the poorly designed houses. This leads to a large scale
deforestation of the areas and causes erosion and environmental problems. The
methodology used consisted of the identification of a typical building and of a
typical meteorological year. Simulations were carried out using a thermal and
airflow software (CODYRUN) to improve each building component (roof, walls,
windows, and soil) in such a way as to estimate the influence of some technical
solutions on each component in terms of thermal comfort. The proposed solutions
also took into account the use of local materials and the standard of living of
the country.


title:
The new science of metagenomics and the challenges of its use in both
  developed and developing countries

abstract:
  Our view of the microbial world and its impact on human health is changing
radically with the ability to sequence uncultured or unculturable microbes
sampled directly from their habitats, ability made possible by fast and cheap
next generation sequencing technologies. Such recent developments represents a
paradigmatic shift in the analysis of habitat biodiversity, be it the human,
soil or ocean microbiome. We review here some research examples and results
that indicate the importance of the microbiome in our lives and then discus
some of the challenges faced by metagenomic experiments and the subsequent
analysis of the generated data. We then analyze the economic and social impact
on genomic-medicine and research in both developing and developed countries. We
support the idea that there are significant benefits in building capacities for
developing high-level scientific research in metagenomics in developing
countries. Indeed, the notion that developing countries should wait for
developed countries to make advances in science and technology that they later
import at great cost has recently been challenged.


title:
Experimental Study on the Conditions for Observing the Josephson Effect
  as a Method for Finding the Right Theory of Superconductivity

abstract:
  The article suggests an experiment enabling to find the right theory of
superconductivity.


title: Difference sets and frequently hypercyclic weighted shifts

abstract:
  We solve several problems on frequently hypercyclic operators. Firstly, we
characterize frequently hypercyclic weighted shifts on $\ell^p(\mathbb Z)$,
$p\geq 1$. Our method uses properties of the difference set of a set with
positive upper density. Secondly, we show that there exists an operator which
is $\mathcal U$-frequently hypercyclic, yet not frequently hypercyclic and that
there exists an operator which is frequently hypercyclic, yet not
distributionally chaotic. These (surprizing) counterexamples are given by
weighted shifts on $c_0$. The construction of these shifts lies on the
construction of sets of positive integers whose difference sets have very
specific properties.


title:
$W^{1,1}_0(\Omega)$ in some borderline cases of elliptic equations with
  degenerate coercivity

abstract:
  We study a degenerate elliptic equation, proving existence results of
distributional solutions in some borderline cases.


title: Groups Whose Chermak-Delgado Lattice is a Chain

abstract:
  For a finite group G with subgroup H the Chermak-Delgado measure of H in G
refer to the product of the order of H with the order of its centralizer,
C_G(H). The set of all subgroups with maximal Chermak-Delgado measure form a
sublattice, CD(G), within the subgroup lattice of G. This paper examines
conditions under which the Chermak-Delgado lattice is a chain of subgroups. On
the basis of a general result how to extend certain Chermak-Delgado lattices,
we construct for any prime p and any non-negative integer n a p-group whose
Chermak-Delgado lattice is a chain of length n.


title:
ISM chemistry in metal rich environments: molecular tracers of
  metallicity

abstract:
  In this paper we use observations of molecular tracers in metal rich and
alpha-enhanced galaxies to study the effect of abundance changes on molecular
chemistry. We selected a sample of metal rich spiral and star bursting objects
from the literature, and present here new data for a sample of early-type
galaxies (ETGs). We conducted the first survey of CS and methanol emission in
ETGs, detecting 7 objects in CS, and 5 in methanol emission. We find evidence
to support the hypothesis that CS is a better tracer of dense star-forming gas
than HCN. We suggest that the methanol emission in these sources is driven by
dust mantle destruction due to ionisation from high mass star formation, but
cannot rule out shocks dominating in some sources. The derived source averaged
CS/methanol column densities and rotation temperatures are similar to those
found in normal spiral and starburst galaxies, suggesting dense clouds are
little affected by the differences between galaxy types. Finally we used the
total column density ratios for our galaxy samples to show for the first time
that some molecular tracers do seem to show systematic variations that appear
to correlate with metallicity, and that these variations roughly match those
predicted by chemical models. Using this fact, the chemical models of Bayet et
al. (2012b), and assumptions about the optical depth we are able to roughly
predict the metallicity of our spiral and ETG sample, with a scatter of ~0.3
dex. We provide the community with linear approximations to the relationship
between the HCN and CS column density ratio and metallicity. Further study will
clearly be required to determine if this, or any, molecular tracer can be used
to robustly determine gas-phase metallically, but that a relationship exists at
all suggests that in the future it may be possible to calibrate a metallicity
indicator for the molecular interstellar medium (abridged).


title: New sensitivity analysis subordinated to a contrast

abstract:
  In a model of the form $Y=h(X_1,\ldots,X_d)$ where the goal is to estimate a
parameter of the probability distribution of $Y$, we define new sensitivity
indices which quantify the importance of each variable $X_i$ with respect to
this parameter of interest. The aim of this paper is to define {\it goal
oriented sensitivity indices} and we will show that Sobol indices are
sensitivity indices associated to a particular characteristic of the
distribution $Y$. We name the framework we present as {\it Goal Oriented
Sensitivity Analysis} (GOSA).


title: Late time acceleration in a slow moving galileon field

abstract:
  In this paper, we examine the cosmological viability of a slow moving
galileon field in a potential. The Lagrangian $\cal{L}$ $
=-\frac{1}{2}g^{\mu\nu}\pi_{;\mu}\pi_{;\nu}
+\frac{G^{\mu\nu}}{2M^2}\pi_{;\mu}\pi_{;\nu}$ respects the galileon symmetry in
curved space time.
  We carry out detailed investigations of the underlying dynamics of this
Lagrangian with Einstein-Hilbert term and a potential. We demonstrate that the
model can give rise to a viable ghost free late time acceleration of universe.
Furthermore we study the cosmological perturbation of the model and see that
the model gives different BBN constraints at early times. We also carry out the
observational analysis of the model and use observational data from growth,
Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations (BAO) and Cosmic
Microwave Background (CMB) to constrain the parameters of the theory.


title:
Reinterpreting the development of extensive air showers initiated by
  nuclei and photons

abstract:
  Ultra-high energy cosmic rays (UHECRs) interacting with the atmosphere
generate extensive air showers (EAS) of secondary particles. The depth
corresponding to the maximum development of the shower, $\Xmax$, is a
well-known observable for determining the nature of the primary cosmic ray
which initiated the cascade process. In this paper, we present an empirical
model to describe the distribution of $\Xmax$ for EAS initiated by nuclei, in
the energy range from $10^{17}$ eV up to $10^{21}$ eV, and by photons, in the
energy range from $10^{17}$ eV up to $10^{19.6}$ eV. Our model adopts the
generalized Gumbel distribution motivated by the relationship between the
generalized Gumbel statistics and the distribution of the sum of
non-identically distributed variables in dissipative stochastic systems. We
provide an analytical expression for describing the $\Xmax$ distribution for
photons and for nuclei, and for their first two statistical moments, namely
$\langle \Xmax\rangle$ and $\sigma^{2}(\Xmax)$. The impact of the hadronic
interaction model is investigated in detail, even in the case of the most
up-to-date models accounting for LHC observations. We also briefly discuss the
differences with a more classical approach and an application to the
experimental data based on information theory.


title:
On 1/f^alpha power laws originating from linear neuronal cable theory:
  power spectral densities of the soma potential, transmembrane current and
  single-neuron contribution to the EEG

abstract:
  Power laws, that is, power spectral densities (PSDs) exhibiting 1/f^alpha
behavior for large frequencies f, have commonly been observed in neural
recordings. Power laws in noise spectra have not only been observed in
microscopic recordings of neural membrane potentials and membrane currents, but
also in macroscopic EEG (electroencephalographic) recordings. While complex
network behavior has been suggested to be at the root of this phenomenon, we
here demonstrate a possible origin of such power laws in the biophysical
properties of single neurons described by the standard cable equation. Taking
advantage of the analytical tractability of the so called ball and stick neuron
model, we derive general expressions for the PSD transfer functions for a set
of measures of neuronal activity: the soma membrane current, the current-dipole
moment (corresponding to the single-neuron EEG contribution), and the soma
membrane potential. These PSD transfer functions relate the PSDs of the
respective measurements to the PSDs of the noisy input currents. With
homogeneously distributed input currents across the neuronal membrane we find
that all PSD transfer functions express asymptotic high-frequency 1/f^alpha
power laws. The corresponding power-law exponents are analytically identified
as alpha_inf^I = 1/2 for the soma membrane current, alpha_inf^p = 3/2 for the
current-dipole moment, and alpha_inf^V = 2 for the soma membrane potential.
These power-law exponents are found for arbitrary combinations of uncorrelated
and correlated noisy input current (as long as both the dendrites and the soma
receive some uncorrelated input currents). Comparison with available data
suggests that the apparent power laws observed in experiments may stem from
uncorrelated current sources, presumably intrinsic ion channels, which are
homogeneously distributed across the neural membranes and themselves exhibit
...


title:
Quantified Energy Dissipation Rates: Electromagnetic Wave Observations
  in the Terrestrial Bow Shock

abstract:
  We present the first quantified measure of the rate of energy dissipated per
unit volume by high frequency electromagnetic waves in the transition region of
the Earth's collisionless bow shock using data from the THEMIS spacecraft.
Every THEMIS shock crossing examined with available wave burst data showed both
low frequency (< 10 Hz) magnetosonic-whistler waves and high frequency (> 10
Hz) electromagnetic and electrostatic waves throughout the entire transition
region and into the magnetosheath. The waves in both frequency ranges had large
amplitudes, but the higher frequency waves, which are the focus of this study,
showed larger contributions to both the Poynting flux and the energy
dissipation rates. The higher frequency waves were identified as combinations
of ion-acoustic waves, electron cyclotron drift instability driven waves,
electrostatic solitary waves, and whistler mode waves. These waves were found
to have: (1) amplitudes capable of exceeding dB ~ 10 nT and dE ~ 300 mV/m,
though more typical values were dB ~ 0.1-1.0 nT and dE ~ 10-50 mV/m; (2) energy
fluxes in excess of 2000 x 10^(-6) W m^(-2); (3) resistivities > 9000 Ohm m;
and (4) energy dissipation rates > 3 x 10^(-6) W m^(-3). The dissipation rates
were found to be in excess of four orders of magnitude greater than was
necessary to explain the increase in entropy across the shocks. Thus, the waves
need only be, at times, < 0.01% efficient to balance the nonlinear wave
steepening that produces the shocks. Therefore, these results show for the
first time that high frequency electromagnetic and electrostatic waves have the
capacity to regulate the global structure of collisionless shocks.


title: Quantum Entanglement on Boundaries

abstract:
  Quantum entanglement in 3 spatial dimensions is studied in systems with
physical boundaries when an entangling surface intersects the boundary. We show
that there are universal logarithmic boundary terms in the entanglement
R\'{e}nyi entropy and derive them for different conformal field theories and
geometrical configurations. The paper covers such topics as spectral geometry
on manifolds with conical singularities crossing the boundaries, the dependence
of the entanglement entropy on mutual position of the boundary and the
entangling surface, effects of acceleration and rotation of the boundary,
relations of coefficients in the trace anomaly to coefficients in the boundary
logarithmic terms in the entropy. The computations are done for scalar, spinor
and gauge fields.


title:
Nonlinear Development of the R Mode Instability and the Maximum Rotation
  Rate of Neutron Stars

abstract:
  We describe how the nonlinear development of the R mode instability of
neutron stars influences spin up to millisecond periods via accretion. Our
arguments are based on nearly-resonant interactions of the R mode with pairs of
"daughter modes". The amplitude of the R mode saturates at the lowest value for
which parametric instability leads to significant excitation of a particular
pair of daughters. The lower bound on this limiting amplitude is proportional
to the damping rate of the daughter modes that are excited parametrically.
Based on this picture, we show that if modes damp because of dissipation in a
very thin boundary layer at the crust-core boundary then spin up to frequencies
larger than about 300 Hz does not occur. Within this conventional scenario the
R mode saturates at an amplitude that is too large for angular momentum gain
from accretion to overcome gravitational loss to gravitational radiation. We
conclude that lower dissipation is required for spin up to frequencies much
higher than 300 Hz. We conjecture that if the transition from the fluid core to
the crystalline crust occurs over a distance much longer than 1 cm then a sharp
viscous boundary layer fails to form. In this case, damping is due to shear
viscosity dissipation integrated over the entire star; the rate is slower than
if a viscous boundary layer forms. We use statistical arguments and scaling
relations to estimate the lowest parametric instability threshold from first
principles. The resulting saturation amplitudes are low enough to permit spin
up to higher frequencies. Further, we show that the requirement that the lowest
parametric instability amplitude be small enough to allow continued spin up
imposes an upper bound to the frequencies that may be attained via accretion
that may plausibly be about 750 Hz. Within this framework, the R mode is
unstable for all millisecond pulsars, whether accreting or not.


title: Semiparalel Wintgen Ideal Surfaces in E^n

abstract:
  Wintgen ideal surfaces in E^4 form an important family of surfaces, namely
surfaces with circular ellipse of curvature. Obviously, Wintgen ideal surfaces
satisfy the pointwise equality K+K_N=H^2. In the present study we consider the
Wintgen ideal surfaces in n-dimensional Euclidean space E^4. We have shown that
Wintgen ideal surfaces in E^n satisfying the semiparallelity condition
R(X,Y)h=0 are totally umbilical. Further, we obtain some results in E^4.


title: Focal Representation of k-slant Helices in E^{m+1}

abstract:
  A focal representation of a generic regular curve {\gamma} in E^{m+1}
consists of the centers of the osculating hyperplanes. A k-slant helix {\gamma}
in E^{m+1} is a (generic) regular curve whose unit normal vector V_{k} makes a
constant angle with a fixed direction U in E^{m+1}. In the present paper we
proved that if {\gamma} is a k-slant helix in E^{m+1}, then the focal
representation C_{{\gamma}} of {\gamma} in E^{m+1} is a (m-k+2)-slant helix in
E^{m+1}.


title: On the weak Lefschetz Property of graded modules over $K[x,y]$

abstract:
  It is known that graded cyclic modules over $S=K[x,y]$ have the Weak
Lefschetz Property (WLP). This is not true for non-cyclic modules over $S$. The
purpose of this note is to study which conditions on $S$-modules ensure the
WLP. We give an algorithm to test the WLP for graded modules with fixed Hilbert
function. In particular, we prove that indecomposable graded modules over $S$
with the Hilbert function $(h_0,h_1)$ have the WLP.


title: Uniformization of higher genus finite type log-Riemann surfaces

abstract:
  We consider a log-Riemann surface $\mathcal{S}$ with a finite number of
ramification points and finitely generated fundamental group. The log-Riemann
surface is equipped with a local holomorphic difffeomorphism $\pi : \mathcal{S}
\to \C$. We prove that $\mathcal{S}$ is biholomorphic to a compact Riemann
surface with finitely many punctures $S$, and the pull-back of the 1-form
$d\pi$ under the biholomorphic map $\phi : S \to \mathcal{S}$ is a 1-form
$\omega = \phi^* d\pi$ with isolated singularities at the punctures of
exponential type, i.e. near each puncture $p$, $\omega = e^h \cdot \omega_0$
where $h$ is a function meromorphic near $p$ and $\omega_0$ a 1-form
meromorphic near $p$.


title:
Radial propagation in population dynamics with density-dependent
  diffusion

abstract:
  The population dynamics that evolves in the radial symmetric geometry is
investigated. The nonlinear reaction-diffusion model, which depends on
population density, is employed as the governing equation for this system. The
approximate analytical solution to this equation has been found. It shows that
the population density evolves from initial state and propagates as the
traveling wave-like for the large time scale. One can be mentioned that, if the
distance is insufficient large, the curvature has ineluctable influence on
density profile and front speed. In comparison, the analytical solution is in
agreement with the numerical solution.


title:
Dynamics and equilibration of Rydberg excitations in dissipative atomic
  ensembles

abstract:
  We study resonant optical excitations of strongly-interacting Rydberg states
of atoms in the presence of relaxations. We employ the quantum stochastic
(Monte Carlo) wavefunctions to simulate the dissipative dynamics of tens of
atoms in two-dimensional lattices. We show that under typical experimental
conditions involving slow Rydberg state decay and sizable relaxation of atomic
coherences, on the time scale of several microseconds the atomic ensemble
approaches a stationary state in which much of the quantum correlations between
the atoms have decayed away. The steady state, however, exhibits strong
classical correlations of Rydberg excitation probabilities.


title:
How different incentives affect homework completion in introductory
  physics courses

abstract:
  This article quantitatively examines the effects that different incentives
have on students' homework completion rates in introductory physics courses at
the United States Air Force Academy. Our data suggest that no more than 10-15%
of the total course points need to be allocated to homework to maximize
completion of homework through a grade incentive. In addition, we find that
there is a strong relationship between students' perception of the benefits of
homework and homework completion rates. Students completed nearly 20% more
homework when their average perception of homework increased by 0.5 points on a
4-point Likert scale. Finally, we find that giving students in-class quizzes
taken directly from homework resulted in 15% greater homework completion than
giving them in-class quizzes that were only conceptually related to homework.
We believe that these quantitative findings, many of which agree with
common-sense notions of physics educators, will significantly aid designers of
introductory physics courses in making homework the most effective learning
tool that it can be for their respective courses.


title: Manual Calibration System for Daya Bay Reactor Neutrino Experiment

abstract:
  The Daya Bay Reactor Neutrino Experiment has measured the last unknown
neutrino mixing angle, {\theta}13, to be non-zero at the 7.7{\sigma} level.
This is the most precise measurement to {\theta}13 to date. To further enhance
the understanding of the response of the antineutrino detectors (ADs), a
detailed calibration of an AD with the Manual Calibration System (MCS) was
undertaken during the summer 2012 shutdown. The MCS is capable of placing a
radioactive source with a positional accuracy of 25 mm in R direction, 20 mm in
Z axis and 0.5{\deg} in {\Phi} direction. A detailed description of the MCS is
presented followed by a summary of its performance in the AD calibration run.


title: Bouncing Loop Quantum Cosmology from $F(T)$ gravity

abstract:
  The big bang singularity could be understood as a breakdown of Einstein's
General Relativity at very high energies. Adopting this viewpoint, other
theories, that implement Einstein Cosmology at high energies, might solve the
problem of the primeval singularity. One of them is Loop Quantum Cosmology
(LQC) with a small cosmological constant that models a universe moving along an
ellipse, which prevents singularities like the big bang or the big rip, in the
phase space $(H,\rho)$, where $H$ is the Hubble parameter and $\rho$ the energy
density of the universe. Using LQC when one considers a model of universe
filled by radiation and matter where, due to the cosmological constant, there
are a de Sitter and an anti de Sitter solution. This means that one obtains a
bouncing non-singular universe which is in the contracting phase at early
times. After leaving this phase, i.e., after bouncing, it passes trough a
radiation and matter dominated phase and finally at late times it expands in an
accelerated way (current cosmic acceleration). This model does not suffer from
the horizon and flatness problems as in big bang cosmology, where a period of
inflation that increases the size of our universe in more than 60 e-folds is
needed in order to solve both problems. The model has two mechanisms to avoid
these problems: The evolution of the universe through a contracting phase and a
period of super-inflation ($\dot{H}> 0$).


title:
Generation of Arbitrarily Non-Gaussian Fields with a Set Correlation
  Structure

abstract:
  Non-Gaussianity in the cosmic microwave background and the large-scale
structure of galaxies provides an increasingly powerful probe of the universe.
I implement an algorithm to generate realisations of fields that possess an
arbitrary probability distribution function and an arbitrary power spectrum and
demonstrate the code with a number of examples, including the uniform
distribution, the Laplace distribution, the $\chi$ and $\chi^2$ distributions,
Rayleigh and Maxwell-Boltzmann distributions. The code is available at
http://sourceforge.net/projects/nongaussian.


title: Noise and fluctuation relations of a spin diode

abstract:
  We consider fluctuation relations between the transport coefficients of a
spintronic system where magnetic interactions play a crucial role. We
investigate a prototypical spintronic device (a spin-diode) which consists of
an interacting resonant level coupled to two ferromagnetic electrodes. We
thereby obtain the cumulant generating function for the spin transport in the
sequential tunnelling regime. We demonstrate the fulfilment of the nonlinear
fluctuation relations when up and down spin currents are correlated in the
presence of both spin-flip processes and external magnetic fields.


title: The degenerate affine walled Brauer algebra

abstract:
  We define a degenerate affine version of the walled Brauer algebra, that has
the same role plaid by the degenerate affine Hecke algebra for the symmetric
group algebra. We use it to prove a higher level mixed Schur-Weyl duality for
gl_N. We consider then families of cyclotomic quotients of level two which
appear naturally in Lie theory and we prove that they inherit from there a
natural grading and a graded cellular structure.


title:
Experimental Summary: Very High Energy Cosmic Rays and their
  Interactions

abstract:
  The XVII International Symposium on Very High Energy Cosmic Ray Interactions,
held in August of 2012 in Berlin, was the first one in the history of the
Symposium, where a plethora of high precision LHC data with relevance for
cosmic ray physics was presented. This report aims at giving a brief summary of
those measurements and it discusses their relevance for observations of high
energy cosmic rays. Enormous progress has been made also in air shower
observations and in direct measurements of cosmic rays, exhibiting many more
structure in the cosmic ray energy spectrum than just a simple power law with a
knee and an ankle. At the highest energy, the flux suppression may not be
dominated by the GZK-effect but by the limiting energy of a nearby source or
source population. New projects and application of new technologies promise
further advances also in the near future. We shall discuss the experimental and
theoretical progress in the field and its prospects for coming years.


title: Effects of Domain Morphology on Kinetics of Fluid Phase Separation

abstract:
  Kinetics of phase separation in a three dimensional single-component
Lennard-Jones fluid, that exhibits vapor-liquid transition, is studied via
molecular dynamics simulations after quenching homogeneous systems, of
different overall densities, inside the coexistence region. For densities close
to the vapor branch of the coexistence curve, phase separation progresses via
nucleation of liquid droplets and collisions among them. This is different from
the evaporation-condensation mechanism proposed by Lifshitz and Slyozov, even
though both lead to power-law growth of average domain size, as a function of
time, with an exponent $\alpha=1/3$. Beyond a certain threshold value of the
overall density, we observe elongated, percolating domain morphology which
suddenly enhances the value of $\alpha$. These results are consistent with some
existing theoretical expectations.


title: Universally Truthful Secondary Spectrum Auctions

abstract:
  We present algorithms for implementing local spectrum redistribution in
wireless networks using a mechanism design approach. For example, in single-hop
request scheduling, secondary users are modeled as rational agents that have
private utility when getting assigned a channel for successful transmission. We
present a rather simple algorithmic technique that allows to turn existing and
future approximation algorithms and heuristics into truthful mechanisms for a
large variety of networking problems. In contrast to previous work, our
approach works for virtually all known interference models in the literature,
including the physical model of interference based on SINR. It allows to
address single-hop and multi-hop scheduling, routing, and even more general
assignment and allocation problems. Our mechanisms are randomized and represent
the first universally-truthful mechanisms for these problems with rigorous
worst-case guarantees on the solution quality. In this way, our mechanisms can
be used to obtain guaranteed solution quality even with risk-averse or
risk-seeking bidders, for which existing approaches fail.


title: Two-photon absorption and emission by Rydberg atoms in coupled cavities

abstract:
  We study the dynamics of a system composed of two coupled cavities, each
containing a single Rydberg atom. The interplay between Rydberg-Rydberg
interaction and photon hopping enables the transition of the atoms from the
collective ground state to the double Rydberg excitation state by individually
interacting with the hybrid cavity modes and suppressing the up conversion
process between them. The atomic transition is accompanied by the two-photon
absorption and emission of the hybrid modes. Since the energy level structure
of the atom-cavity system is photon number dependent, there is only a pair of
states being in the two-photon resonance. Therefore, the system can act as a
quantum nonlinear absorption filter through the nonclassical quantum process,
converting coherent light field into a non-classical state. Meanwhile, the
vacuum field in the cavity inspires the Rydberg atoms to simultaneously emit
two photons into the hybrid mode, resulting in obvious emission enhancement of
the mode.


title: Speech Enhancement Using Pitch Detection Approach For Noisy Environment

abstract:
  Acoustical mismatch among training and testing phases degrades outstandingly
speech recognition results. This problem has limited the development of
real-world nonspecific applications, as testing conditions are highly variant
or even unpredictable during the training process. Therefore the background
noise has to be removed from the noisy speech signal to increase the signal
intelligibility and to reduce the listener fatigue. Enhancement techniques
applied, as pre-processing stages; to the systems remarkably improve
recognition results. In this paper, a novel approach is used to enhance the
perceived quality of the speech signal when the additive noise cannot be
directly controlled. Instead of controlling the background noise, we propose to
reinforce the speech signal so that it can be heard more clearly in noisy
environments. The subjective evaluation shows that the proposed method improves
perceptual quality of speech in various noisy environments. As in some cases
speaking may be more convenient than typing, even for rapid typists: many
mathematical symbols are missing from the keyboard but can be easily spoken and
recognized. Therefore, the proposed system can be used in an application
designed for mathematical symbol recognition (especially symbols not available
on the keyboard) in schools.


title: Compressed threshold pivoting for sparse symmetric indefinite systems

abstract:
  A key technique for controlling numerical stability in sparse direct solvers
is threshold partial pivoting. When selecting a pivot, the entire candidate
pivot column below the diagonal must be up-to-date and must be scanned. If the
factorization is parallelized across a large number of cores, communication
latencies can be the dominant computational cost.
  In this paper, we propose two alternative pivoting strategies for sparse
symmetric indefinite matrices that significantly reduce communication by
compressing the necessary data into a small matrix that can be used to select
pivots. Once pivots have been chosen, they can be applied in a
communication-efficient fashion.
  For an n x p submatrix on P processors, we show our methods perform a
factorization using O(log P) messages instead of the O(p log P) for threshold
partial pivoting. The additional costs in terms of operations and communication
bandwidth are relatively small.
  A stability proof is given and numerical results using a range of symmetric
indefinite matrices arising from practical problems are used to demonstrate the
practical robustness. Timing results on large random examples illustrate the
potential speedup on current multicore machines.


title:
The interstellar medium and the massive stellar content toward the SNR
  G18.1-0.1 and neighboring HII regions

abstract:
  We perform a multiwavelength study toward the SNR G18.1-0.1 and nearby
several HII regions (infrared dust bubbles N21 and N22, and the HII regions
G018.149-00.283 and G18.197-00.181). Our goal is to provide observational
evidence supporting that massive stars usually born in clusters from the same
molecular cloud, which then produce, along their evolution, different
neighboring objects such as HII regions, interstellar bubbles and supernova
remnants. We suggest that the objects analysed in this work belong to a same
complex located at the distance of about 4 kpc. Using molecular data we
inspected the interstellar medium toward this complex and from optical and
X-ray observations we looked for OB-type stars in the region. Analysing public
13CO J=1--0 data we found several molecular structures very likely related to
the HII region/SNR complex. We suggest that the molecular gas is very likely
being swept and shaped by the expansion of the HII regions. From spectroscopic
optical observations obtained with the 2.15 m telescope at CASLEO, Argentina,
we discovered three O-type stars very likely exciting the bubbles N21 and N22,
and an uncatalogued HII region northward bubble N22, respectively. Also we
found four B0-5 stars, one toward the bubble N22 and the others within the HII
region G18.149-0.283. By inspecting the Chandra Source Catalog we found two
point X-ray sources and we suggest that one of them is an early O-type star.
Finally we inspected the large scale interstellar medium around this region. We
discovered a big molecular shell of about 70 pc x 28 pc in which the analysed
complex appears to be located in its southern border.


title: Projective surfaces of maximal sectional regularity

abstract:
  We study projective surfaces $X \subset \mathbb{P}^r$ (with $r \geq 5$) of
maximal sectional regularity and degree $d > r$, hence surfaces for which the
Castelnuovo-Mumford regularity $\reg(C)$ of a general hyperplane section curve
$C = X \cap \mathbb{P}^{r-1}$ takes the maximally possible value $d-r+3$. We
show that each of these surfaces is either a cone over a curve $C \subset
\mathbb{P}^{r-1}$ of maximal regularity or else a birational outer linear
projection of a smooth rational surface scroll $\widetilde{X} \subset
\mathbb{P}^{d+1}$. We prove that the Castelnuovo-Mumford regularity of these
surfaces satisfies the equality $\reg(X) = d-r+3$ and we compute or estimate
various of their cohomological invariants as well as their Betti numbers. We
study the the extremal variety $\mathbb{F}(X)$ of these surfaces $X$, that is
the closed union of the extremal secant lines of all smooth hyperplane section
curves of $X$. We show that $\mathbb{F}(X)$ is either a plane or that otherwise
$r =5$ and $\mathbb{F}(X)$ is a rational smooth threefold scroll $S(1,1,1)
\subset \mathbb{P}^5$.


title:
Hubble Space Telescope spectra of the type Ia supernova SN2011fe: a tail
  of low-density, high-velocity material with Z<Zsolar

abstract:
  Hubble Space Telescope spectroscopic observations of the nearby type Ia
supernova (SN Ia) SN2011fe, taken on 10 epochs from -13.1 to +40.8 days
relative to B-band maximum light, and spanning the far-ultraviolet (UV) to the
near-infrared (IR) are presented. This spectroscopic coverage makes SN2011fe
the best-studied local SN Ia to date. SN2011fe is a typical moderately-luminous
SN Ia with no evidence for dust extinction. Its near-UV spectral properties are
representative of a larger sample of local events (Maguire et al. 2012). The
near-UV to optical spectra of SN2011fe are modelled with a Monte Carlo
radiative transfer code using the technique of 'abundance tomography',
constraining the density structure and the abundance stratification in the SN
ejecta. SN2011fe was a relatively weak explosion, with moderate Fe-group
yields. The density structures of the classical model W7 and of a delayed
detonation model were tested. Both have shortcomings. An ad-hoc density
distribution was developed which yields improved fits and is characterised by a
high-velocity tail, which is absent in W7. However, this tail contains less
mass than delayed detonation models. This improved model has a lower energy
than one-dimensional explosion models matching typical SNe Ia (e.g. W7, WDD1).
The derived Fe abundance in the outermost layer is consistent with the
metallicity at the SN explosion site in M101 (~0.5 Zsolar). The spectroscopic
rise time (~19 days) is significantly longer than that measured from the early
optical light curve, implying a 'dark phase' of ~1 day. A longer rise time has
significant implications when deducing the properties of the white dwarf and
binary system from the early photometric behaviour.


title:
Immunization strategies for epidemic processes in time-varying contact
  networks

abstract:
  Spreading processes represent a very efficient tool to investigate the
structural properties of networks and the relative importance of their
constituents, and have been widely used to this aim in static networks. Here we
consider simple disease spreading processes on empirical time-varying networks
of contacts between individuals, and compare the effect of several immunization
strategies on these processes. An immunization strategy is defined as the
choice of a set of nodes (individuals) who cannot catch nor transmit the
disease. This choice is performed according to a certain ranking of the nodes
of the contact network. We consider various ranking strategies, focusing in
particular on the role of the training window during which the nodes'
properties are measured in the time-varying network: longer training windows
correspond to a larger amount of information collected and could be expected to
result in better performances of the immunization strategies. We find instead
an unexpected saturation in the efficiency of strategies based on nodes'
characteristics when the length of the training window is increased, showing
that a limited amount of information on the contact patterns is sufficient to
design efficient immunization strategies. This finding is balanced by the large
variations of the contact patterns, which strongly alter the importance of
nodes from one period to the next and therefore significantly limit the
efficiency of any strategy based on an importance ranking of nodes. We also
observe that the efficiency of strategies that include an element of randomness
and are based on temporally local information do not perform as well but are
largely independent on the amount of information available.


title: Infinities as a measure of our ignorance

abstract:
  The quantization of gravity offers a solution to the presence of
singularities in cosmology. Infinities are removed because of the existence of
finite quanta of spacetime. This is one of the most important prediction of
Loop Quantum Gravity. But treating gravity on the same footing as the other
quantum field theories introduces a different kind of infinities: the ones from
the renormalization procedure. In the covariant formulation of Loop Quantum
Gravity (Spinfoam) this kind of infinities are tamed by the presence of the
cosmological constant. These two results are guided by a specific perspective
on the appearance of infinity in physics: this is just interpreted as a
signpost that the theory should be improved. It arises from our limited
knowledge, and not as a fundamental fact of nature.


title: Ultra-high magnetic field study of the layer split bands in Graphite

abstract:
  We report studies of the magnetospectroscopy of graphite into a new regime of
high energies and ultra-high magnetic fields which allows us to perform the
first spectroscopic studies of the interlayer split off bands, $E_{1}$ and
$E_{2}$. These bands can be well described by an asymmetric bilayer model and
have only a small interlayer band gap asymmetry. We show that all of the
properties of the electrons and holes can be described by a simple relativistic
behaviour determined by $\gamma_{0}$ and $\gamma_{1}$.


title:
In situ measurement of the electron drift velocity for upcoming
  directional Dark Matter detectors

abstract:
  Three-dimensional track reconstruction is a key issue for directional Dark
Matter detection and it requires a precise knowledge of the electron drift
velocity. Magboltz simulations are known to give a good evaluation of this
parameter. However, large TPC operated underground on long time scale may be
characterized by an effective electron drift velocity that may differ from the
value evaluated by simulation. In situ measurement of this key parameter is
hence needed as it is a way to avoid bias in the 3D track reconstruction. We
present a dedicated method for the measurement of the electron drift velocity
with the MIMAC detector. It is tested on two gas mixtures: CF4 and CF4 + CHF3.
The latter has been chosen for the MIMAC detector as we expect that adding CHF3
to pure CF4 will lower the electron drift velocity. This is a key point for
directional Dark Matter as the track sampling along the drift field will be
improved while keeping almost the same Fluorine content of the gas mixture. We
show that the drift velocity at 50 mbar is reduced by a factor of about 5 when
adding 30% of CHF3.


title: Nonlinear cross-Kerr quasiclassical dynamics

abstract:
  We study the quasiclassical dynamics of the cross-Kerr effect. In this
approximation, the typical periodical revivals of the decorrelation between the
two polarization modes disappear and they remain entangled. By mapping the
dynamics onto the Poincare space, we find simple conditions for polarization
squeezing. When dissipation is taken into account, the shape of the states in
such a space is not considerably modified, but their size is reduced.


title: Revisiting Bayesian Blind Deconvolution

abstract:
  Blind deconvolution involves the estimation of a sharp signal or image given
only a blurry observation. Because this problem is fundamentally ill-posed,
strong priors on both the sharp image and blur kernel are required to
regularize the solution space. While this naturally leads to a standard MAP
estimation framework, performance is compromised by unknown trade-off parameter
settings, optimization heuristics, and convergence issues stemming from
non-convexity and/or poor prior selections. To mitigate some of these problems,
a number of authors have recently proposed substituting a variational Bayesian
(VB) strategy that marginalizes over the high-dimensional image space leading
to better estimates of the blur kernel. However, the underlying cost function
now involves both integrals with no closed-form solution and complex,
function-valued arguments, thus losing the transparency of MAP. Beyond standard
Bayesian-inspired intuitions, it thus remains unclear by exactly what mechanism
these methods are able to operate, rendering understanding, improvements and
extensions more difficult. To elucidate these issues, we demonstrate that the
VB methodology can be recast as an unconventional MAP problem with a very
particular penalty/prior that couples the image, blur kernel, and noise level
in a principled way. This unique penalty has a number of useful characteristics
pertaining to relative concavity, local minima avoidance, and scale-invariance
that allow us to rigorously explain the success of VB including its existing
implementational heuristics and approximations. It also provides strict
criteria for choosing the optimal image prior that, perhaps
counter-intuitively, need not reflect the statistics of natural scenes. In so
doing we challenge the prevailing notion of why VB is successful for blind
deconvolution while providing a transparent platform for introducing
enhancements.


title: Ultra-High Energy Cosmic Rays: Results and Prospects

abstract:
  Observations of cosmic rays have been improved at all energies, both in terms
of higher statistics and reduced systematics. As a result, the all particle
cosmic ray energy spectrum starts to exhibit more structures than could be seen
previously. Most importantly, a second knee in the cosmic ray spectrum --
dominated by heavy primaries -- is reported just below 10^{17} eV. The light
component, on the other hand, exhibits an ankle like feature above 10^{17} eV
and starts to dominate the flux at the ankle. The key question at the highest
energies is about the origin of the flux suppression observed at energies above
5 x 10^{19} eV. Is this the long awaited GZK-effect or the exhaustion of
sources? The key to answering this question is again given by the still largely
unknown mass composition at the highest energies. Data from different
observatories don't quite agree and common efforts have been started to settle
that question. The high level of isotropy observed even at the highest energies
starts to challenge a proton dominated composition if extragalactic (EG)
magnetic fields are on the order of a few nG or more. We shall discuss the
experimental and theoretical progress in the field and the prospects for the
next decade.


title:
Static fluctuations of a thick 1D interface in the 1+1 Directed Polymer
  formulation: numerical study

abstract:
  We study numerically the geometrical and free-energy fluctuations of a static
one-dimensional (1D) interface with a short-range elasticity, submitted to a
quenched random-bond Gaussian disorder of finite correlation length $\xi>0$,
and at finite temperature $T$. Using the exact mapping from the static 1D
interface to the 1+1 Directed Polymer (DP) growing in a continuous space, we
focus our analysis on the disorder free-energy of the DP endpoint, a quantity
which is strictly zero in absence of disorder and whose sample-to-sample
fluctuations at a fixed growing `time' $t$ inherit the statistical
translation-invariance of the microscopic disorder explored by the DP.
Constructing a new numerical scheme for the integration of the
Kardar-Parisi-Zhang (KPZ) evolution equation obeyed by the free-energy, we
address numerically the `time'- and temperature-dependence of the disorder
free-energy fluctuations at fixed finite $\xi$. We examine on one hand the
amplitude $\tilde{D}_{t}$ and effective correlation length $\tilde{\xi}_t$ of
the free-energy fluctuations, and on the other hand the imprint of the specific
microscopic disorder correlator on the large-`time' shape of the free-energy
two-point correlator. We observe numerically the crossover to a low-temperature
regime below a finite characteristic temperature $T_c(\xi)$, as previously
predicted by Gaussian-Variational-Method (GVM) computations and scaling
arguments, and extensively investigated analytically in [Phys. Rev. E, 87
042406 (2013)]. Finally we address numerically the `time'- and
temperature-dependence of the roughness $B(t)$, which quantifies the DP
endpoint transverse fluctuations, and we show how the amplitude
$\tilde{D}_{\infty}(T,\xi)$ controls the different regimes experienced by
$B(t)$ -- in agreement with the analytical predictions of a DP `toymodel'
approach.

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


title:
Mindlin second-gradient elastic properties from dilute two-phase
  Cauchy-elastic composites Part I: Closed form expression for the effective
  higher-order constitutive tensor

abstract:
  It is shown that second-order homogenization of a Cauchy-elastic dilute
suspension of randomly distributed inclusions yields an equivalent second
gradient (Mindlin) elastic material. This result is valid for both plane and
three-dimensional problems and extends earlier findings by Bigoni and Drugan
(Analytical derivation of Cosserat moduli via homogenization of heterogeneous
elastic materials. J. Appl. Mech., 2007, 74, 741-753) from several points of
view: (i.) the result holds for anisotropic phases with spherical or circular
ellipsoid of inertia; (ii.) the displacement boundary conditions considered in
the homogenization procedure is independent of the characteristics of the
material; (iii.) a perfect energy match is found between heterogeneous and
equivalent materials (instead of an optimal bound). The constitutive
higher-order tensor defining the equivalent Mindlin solid is given in a
surprisingly simple formula. Applications, treatment of material symmetries and
positive definiteness of the effective higher-order constitutive tensor are
deferred to Part II of the present article.


title: Observation of conduction electron spin resonance in boron doped diamond

abstract:
  We observe the electron spin resonance of conduction electrons in boron doped
(6400 ppm) superconducting diamond (Tc =3.8 K). We clearly identify the
benchmarks of conduction electron spin resonance (CESR): the nearly temperature
independent ESR signal intensity and its magnitude which is in good agreement
with that expected from the density of states through the Pauli
spin-susceptibility. The temperature dependent CESR linewidth weakly increases
with increasing temperature which can be understood in the framework of the
Elliott-Yafet theory of spin-relaxation. An anomalous and yet unexplained
relation is observed between the g-factor, CESR linewidth, and the resistivity
using the empirical Elliott-Yafet relation.


title: Time-resolved second-order correlations of microcavity photons

abstract:
  The time dependence of the correlations between the photons, emitted from the
microcavity with embedded quantum dot under incoherent pumping, is studied
theoretically. Analytical expressions for the second-order correlation function
g2(t) are presented in strong and weak coupling regimes. At moderate pumping
the correlation function demonstrates Rabi oscillations, while at larger
pumping it shows monoexponential decay. The decay time of the correlations
nonmonotonously depends on the pumping value and has a maximum corresponding to
the self-quenching transition.


title: A Characterization of the Prime Graphs of Solvable Groups

abstract:
  Let \pi(G) denote the set of prime divisors of the order of a finite group G.
The prime graph of G is the graph with vertex set \pi(G) with edges {p,q} if
and only if there exists an element of order pq in G. In this paper, we prove
that a graph is isomorphic to the prime graph of a solvable group if and only
if its complement is 3-colorable and triangle free. We then introduce the idea
of a minimal prime graph. We prove that there exists an infinite class of
solvable groups whose prime graphs are minimal. We prove the 3k-conjecture on
prime divisors in element orders for solvable groups with minimal prime graphs,
and we show that solvable groups whose prime graphs are minimal have Fitting
length 3 or 4.


title:
Priority Based Energy-Efficient Data Forwarding Algorithm in Wireless
  Sensor Networks

abstract:
  A Wireless Sensor Network(WSN) can be described as a collection of untethered
sensor nodes. An important application of WSNs is in the field of real-time
communication. Real-time communication is a critical service which requires a
qualitative routing protocol for energy-efficient network communication. The
judicious use of energy of the network nodes is essential and important for
sustainability and longevity of a WSN. This paper proposes an algorithm namely
Priority-Energy Based Data Forwarding Algorithm(PEDF) which empowers the node
to choose the most suitable packet forwarding path, based on the priority of
the packet and the current energy status of the forwarding node. The algorithm
hence dynamically adapts to the prevailing energy-scenario of the network and
takes routing decisions accordingly, based on packet priority. Minimizing
delay, minimizing energy utilization, maximizing throughput and maximizing
network lifetime are the key elements of the proposed algorithm.


title:
Scalable, Robust and Real Time Communication Architecture For Wireless
  Sensor Networks

abstract:
  In this paper we propose wireless sensor network architecture with layered
protocols, targeting different aspects of the awareness requirements in
wireless sensor networks. Under such a unified framework, we pay special
attention to the most important awareness issues in wireless sensor networks:
namely dynamic awareness, energy awareness and spatiotemporal awareness. First,
we propose the spatiotemporal aware routing protocol for wireless sensor
networks, which maintains a constant delivery speed for soft real-time
communication. Second, we introduce the time-energy aware aggregation scheme,
which increases the degree of aggregation and reduces energy consumption
without jeopardizing the end-to-end delay. It is the data aggregation scheme to
take the timely delivery of messages as well as protocol overhead into account
to adjust aggregation strategies adaptively in accordance with assessed traffic
conditions and expected wireless sensor network requirements. Third, we also
deal with dynamic awareness by proposing a new communication category based on
a lazy-binding concept. The evaluation of this integrated architecture
demonstrates its performance composability and its capability to be tailored
for applications with different awareness requirements. We believe that the
integrated architecture, supporting various kinds of awareness requirements,
lays a foundation for overall wireless sensor network.


title:
The IRAM-30m line survey of the Horsehead PDR: III. High abundance of
  complex (iso-)nitrile molecules in UV-illuminated gas

abstract:
  Complex (iso-)nitrile molecules, such as CH3CN and HC3N, are relatively
easily detected in our Galaxy and in other galaxies. We constrain their
chemistry through observations of two positions in the Horsehead edge: the
photo-dissociation region (PDR) and the dense, cold, and UV-shielded core just
behind it. We systematically searched for lines of CH3CN, HC3N, C3N, and some
of their isomers in our sensitive unbiased line survey at 3, 2, and 1mm. We
derived column densities and abundances through Bayesian analysis using a large
velocity gradient radiative transfer model. We report the first clear detection
of CH3NC at millimeter wavelength. We detected 17 lines of CH3CN at the PDR and
6 at the dense core position, and we resolved its hyperfine structure for 3
lines. We detected 4 lines of HC3N, and C3N is clearly detected at the PDR
position. We computed new electron collisional rate coefficients for CH3CN, and
we found that including electron excitation reduces the derived column density
by 40% at the PDR position. While CH3CN is 30 times more abundant in the PDR
than in the dense core, HC3N has similar abundance at both positions. The
isomeric ratio CH3NC/CH3CN is 0.15+-0.02. In the case of CH3CN, pure gas phase
chemistry cannot reproduce the amount of CH3CN observed in the UV-illuminated
gas. We propose that CH3CN gas phase abundance is enhanced when ice mantles of
grains are destroyed through photo-desorption or thermal-evaporation in PDRs,
and through sputtering in shocks. (abridged)


title:
A Study of the forced Van der Pol generalized oscillator with
  renormalization group method

abstract:
  In this paper the equation of forced Van der Pol generalized oscillator is
examined with renormalization group method. A brief recall of the
renormalization group technique is done. We have applied this method to the
equation of forced Van der Pol generalized oscillator to search for its
asymptotic solution and its renormalization group equation. The analysis of the
numerical simulation graph is done; the method's efficiency is pointed out.


title:
Heat and Moisture Transport in Unsaturated Porous Media -- A Coupled
  Model in Terms of Chemical Potential

abstract:
  Transport phenomena in porous media are commonplace in our daily lives.
Examples and applications include heat and moisture transport in soils, baking
and drying of food stuffs, curing of cement, and evaporation of fuels in wild
fires. Of particular interest to this study are heat and moisture transport in
unsaturated soils. Historically, mathematical models for these processes are
derived by coupling classical Darcy's, Fourier's, and Fick's laws with volume
averaged conservation of mass and energy and empirically based source and sink
terms. Recent experimental and mathematical research has proposed modifications
and suggested limitations in these classical equations. The primary goal of
this thesis is to derive a thermodynamically consistent system of equations for
heat and moisture transport in terms of the chemical potential that addresses
some of these limitations. The physical processes of interest are primarily
diffusive in nature and, for that reason, we focus on using the macroscale
chemical potential to build and simplify the models. The resulting coupled
system of nonlinear partial differential equations is solved numerically and
validated against the classical equations and against experimental data. It
will be shown that under a mixture theoretic framework, the classical Richards'
equation for saturation is supplemented with gradients in temperature, relative
humidity, and the time rate of change of saturation. Furthermore, it will be
shown that restating the water vapor diffusion equation in terms of chemical
potential eliminates the necessity for an empirically based fitting parameter.


title:
Vacuum stability of supersymmetric extended Higgs sectors with a
  discrete symmetry

abstract:
  We study vacuum stability of supersymmetric extended Higgs sectors with a
discrete $Z_2$ symmetry. These models may be able to explain dark matter,
neutrino masses, baryon asymmetry of the Universe and hierarchy problem
simultaneously at the TeV scale. This $Z_2$ symmetry could be broken
spontaneously. We examine the stability of the $Z_2$ symmetric vacuum at the
tree level in several models with such extended Higgs sectors.


title:
Estimate for a solution to the water wave problem in the presence of a
  submerged body

abstract:
  We study the two-dimensional problem of propagation of linear water waves in
deep water in the presence of a submerged body. Under some geometrical
requirements, we derive an explicit bound for the solution depending on the
domain and the functions on the right-hand side.


title:
Quantum Calculation of Inelastic CO Collisions with H: I. rotational
  quenching of low-lying rotational levels

abstract:
  New quantum scattering calculations for rotational deexcitation transitions
of CO induced by H collisions using two CO-H potential energy surfaces (PESs)
from Shepler et al. (2007) are reported. State-to-state rate coefficients are
computed for temperatures ranging from 1 to 3000 K for CO($v=0,j$) deexcitation
from $j=1-5$ to all lower $j^\prime$ levels, with $j$ being the rotational
quantum number. Different resonance structures in the cross sections are
attributed to the differences in the anisotropy and the long-range van der
Waals well depths of the two PESs. These differences affect rate coefficients
at low temperatures and give an indication of the uncertainty of the results.
Significant discrepancies are found between the current rate coefficients and
previous results computed using earlier potentials, while the current results
satisfy expected propensity rules. Astrophysical applications to modeling far
infrared and submillimeter observations are briefly discussed.


title: Nonabelian holomorphic Lie algebroid extensions

abstract:
  We classify nonabelian extensions of Lie algebroids in the holomorphic
category. Moreover we study a spectral sequence associated to any such
extension. This spectral sequence generalizes the Hochschild-Serre spectral
sequence for Lie algebras to the holomorphic Lie algebroid setting. As an
application, we show that the hypercohomology of the Atiyah algebroid of a line
bundle has a natural Hodge structure.


title: Quantifying the effects of anagenetic and cladogenetic evolution

abstract:
  An ongoing debate in evolutionary biology is whether phenotypic change occurs
predominantly around the time of speciation or whether it instead accumulates
gradually over time. In this work I propose a general framework incorporating
both types of change, quantify the effects of speciational change via the
correlation between species and attribute the proportion of change to each
type. I discuss results of parameter estimation of Hominoid body size in this
light. I derive mathematical formulae related to this problem, the probability
generating functions of the number of speciation events along a randomly drawn
lineage and from the most recent common ancestor of two randomly chosen tip
species for a conditioned Yule tree. Additionally I obtain in closed form the
variance of the distance from the root to the most recent common ancestor of
two randomly chosen tip species.


title: Simons' type equation for $f$-minimal hypersurfaces and applications

abstract:
  We derive the Simons' type equation for $f$-minimal hypersurfaces in weighted
Riemannian manifolds and apply it to obtain a pinching theorem for closed
$f$-minimal hypersurfaces immersed in the product manifold
$\mathbb{S}^n(\sqrt{2(n-1)})\times \mathbb{R}$ with $f=\frac {t^2}{4}$. Also we
classify closed $f$-minimal hypersurfaces with $L_f$-index one immersed in
$\mathbb{S}^n(\sqrt{2(n-1)})\times \mathbb{R}$ with the same $f$ as above.


title:
Mindlin second-gradient elastic properties from dilute two-phase
  Cauchy-elastic composites Part II: Higher-order constitutive properties and
  application cases

abstract:
  Starting from a Cauchy elastic composite with a dilute suspension of randomly
distributed inclusions and characterized at first-order by a certain
discrepancy tensor (see part I of the present article), it is shown that the
equivalent second-gradient Mindlin elastic solid: (i.) is positive definite
only when the discrepancy tensor is negative defined; (ii.) the non-local
material symmetries are the same of the discrepancy tensor, and (iii.) the
nonlocal effective behaviour is affected by the shape of the RVE, which does
not influence the first-order homogenized response. Furthermore, explicit
derivations of non-local parameters from heterogeneous Cauchy elastic
composites are obtained in the particular cases of: (a) circular cylindrical
and spherical isotropic inclusions embedded in an isotropic matrix, (b)
n-polygonal cylindrical voids in an isotropic matrix, and (c) circular
cylindrical voids in an orthortropic matrix.


title: Weak localization scattering lengths in epitaxial, and CVD graphene

abstract:
  Weak localization in graphene is studied as a function of carrier density in
the range from 1 x $10^{11}$\,cm$^{-2}$ to 1.43 x $10^{13}$\,cm$^{-2}$ using
devices produced by epitaxial growth onto SiC and CVD growth on thin metal
film. The magnetic field dependent weak localization is found to be well fitted
by theory, which is then used to analyse the dependence of the scattering
lengths L$_\varphi$, L$_i$, and L$_*$ on carrier density. We find no
significant carrier dependence for L$_\varphi$, a weak decrease for L$_i$ with
increasing carrier density just beyond a large standard error, and a
n$^{-\frac{1}{4}}$ dependence for L$_*$. We demonstrate that currents as low as
0.01\,nA are required in smaller devices to avoid hot-electron artefacts in
measurements of the quantum corrections to conductivity.


title:
Impact of active-sterile neutrino mixing on supernova explosion and
  nucleosynthesis

abstract:
  We show that for the active-sterile flavor mixing parameters suggested by the
reactor neutrino anomaly, substantial \\nu_e-\\nu_s and \bar \\nu_e-\bar \\nu_s
conversion occurs in regions with electron fraction of \approx 1/3 near the
core of an 8.8 M_sun electron-capture supernova. Compared to the case without
such conversion, the neutron-richness of the ejected material is enhanced to
allow production of elements from Sr, Y, and Zr up to Cd in broad agreement
with observations of the metal-poor star HD 122563. Active-sterile flavor
conversion also strongly suppresses neutrino heating at times when it is
important for the revival of the shock. Our results suggest that simulations of
supernova explosion and nucleosynthesis may be used to constrain active-sterile
mixing parameters in combination with neutrino experiments and cosmological
considerations.


title:
First constraint on the mass of doubly-charged Higgs bosons in the
  same-sign diboson decay scenario at the LHC

abstract:
  When the doubly-charged Higgs bosons $H^{\pm\pm}$ mainly decay into the
same-sign dilepton, a lower bound on the mass is around 400 GeV by the current
LHC data. On the other hand, no such bound has been reported by using the data
at LEP and at the LHC for the case where the same-sign diboson decay
$H^{\pm\pm}\to W^{\pm(*)} W^{\pm(*)}$ is dominant. We study limits on the mass
for such a case by using the current experimental data. From the precise
measurement of the total width of the Z boson at the LEP experiment, the mass
below 43 GeV is excluded with the 95% C.L. It turns out that the results from
four charged lepton searches at LEP do not provide any significant constraint.
We show that a new lower bound is obtained in the diboson decay scenario at the
LHC with the collision energy to be 7 TeV and the integrated luminosity to be
4.7 fb$^{-1}$. By using the data of the same-sign dilepton events, the lower
limit is found to be 60 GeV at the 95% C.L. By the extrapolation of the data to
20 fb$^{-1}$ with the same collision energy, the lower limit is evaluated to be
85 GeV.


title:
Asymptotic metrics on the space of matrices under the commutation
  relation

abstract:
  We show that the norm of the commutator defines "almost a metric" on the
quotient space of commuting matrices, in the sense that it is a semi-metric
satisfying the triangle inequality asymptotically for large matrices drawn from
a "good" distribution.


title: Extremal entanglement witnesses

abstract:
  We study extremal entanglement witnesses on a bipartite quantum system. We
define the cone of witnesses as the dual of the set of separable density
matrices, thus $\textrm{Tr}\,\Omega\rho\geq 0$ when $\Omega$ is a witness and
$\rho$ a pure product state, $\rho=\psi\psi^{\dagger}$ with
$\psi=\phi\otimes\chi$. The set of witnesses of unit trace is a compact convex
set, defined by its extremal points. The expectation value
$f(\phi,\chi)=\mathrm{Tr}\,\Omega\rho$ as a function of $\phi$ and $\chi$ is a
nonnegative biquadratic form. Every zero of $f(\phi,\chi)$ imposes real-linear
constraints on $f$ and $\Omega$. The Hessian matrix at the zero must be
nonnegative. Its eigenvectors with zero eigenvalue, if any, we call Hessian
zeros. A zero of $f(\phi,\chi)$ is quadratic if it has no Hessian zeros,
otherwise it is quartic. We call a witness quadratic if it has only quadratic
zeros, and quartic otherwise. We prove that a witness is extremal if and only
if no other witness has the same, or a larger, set of zeros and Hessian zeros.
A quadratic extremal witness has a minimum number of isolated zeros depending
on dimensions. If a witness is not extremal, the constraints defined by its
zeros and Hessian zeros determine all directions in which to search for
witnesses having more zeros or Hessian zeros. A finite number of iterated
searches in random directions lead to an extremal witness which is usually
quadratic with the minimum number of zeros. We discuss some topics related to
extremal witnesses, in particular the relation between the facial structures of
the dual sets of witnesses and separable states. We discuss the relation
between extremality and optimality of witnesses, and a conjecture of
separability of the structural physical approximation (SPA) of an optimal
witness. We discuss how to treat the entanglement witnesses on a complex
Hilbert space as witnesses on a real Hilbert space.


title: Disappointment in Social Choice Protocols

abstract:
  Social choice theory is a theoretical framework for analysis of combining
individual preferences, interests, or welfare to reach a collective decision or
social welfare in some sense. We introduce a new criterion for social choice
protocols called social disappointment. Social disappointment happens when the
outcome of a voting system occurs for those alternatives which are at the end
of at least half of individual preference profiles. Here we introduce some
protocols that prevent social disappointment and prove an impossibility theorem
based on this key concept.


title: Loss Rate Based Fountain Codes for Data Transfer

abstract:
  Fountain codes are becoming increasingly important for data transferring over
dedicated high-speed long-distance network. However, the encoding and decoding
complexity of traditional fountain codes such as LT and Raptor codes are still
high. In this paper, a new fountain codes named LRF (Loss Rate Based Fountain)
codes for data transfer is proposed. In order to improve the performance of
encoding and decoding efficiency and decrease the number of redundant encoding
symbols, an innovative degree distribution instead of robust soliton degree
distribution in LT (Luby Transfer) codes is proposed. In LRF codes, the degree
of encoding symbol is decided by loss rate property, and the window size is
extended dynamic. Simulations result using LRF codes show that the proposed
method has better performance in term of encoding ratio, degree ratio, encoding
and decoding efficiency with respect to LT and Raptor codes.


title: Fast Feature Reduction in intrusion detection datasets

abstract:
  In the most intrusion detection systems (IDS), a system tries to learn
characteristics of different type of attacks by analyzing packets that sent or
received in network. These packets have a lot of features. But not all of them
is required to be analyzed to detect that specific type of attack. Detection
speed and computational cost is another vital matter here, because in these
types of problems, datasets are very huge regularly. In this paper we tried to
propose a very simple and fast feature selection method to eliminate features
with no helpful information on them. Result faster learning in process of
redundant feature omission. We compared our proposed method with three most
successful similarity based feature selection algorithm including Correlation
Coefficient, Least Square Regression Error and Maximal Information Compression
Index. After that we used recommended features by each of these algorithms in
two popular classifiers including: Bayes and KNN classifier to measure the
quality of the recommendations. Experimental result shows that although the
proposed method can't outperform evaluated algorithms with high differences in
accuracy, but in computational cost it has huge superiority over them.


title: Hadronic Production of $chi_c$-mesons at LHC

abstract:
  Hadronic production of $P$-wave charmonium states $\chi_{cJ}$ in hadronic
interaction is considered. Using experimental results of CDF and LHCb
collaborations we show, that contributions of color-singlet components are
dominant. As for color-octet mechanism, we show, that contributions from
$P$-wave states can also be observed, while $S$-wave states can be neglected.
The best experimental observables that give information about relative
importance of color-singlet and color-octet components are the ratios
$\chi_{c2}/\chi_{c1}$ and $\chi_{c0}/\chi_{c1}$.


title:
Search for gluino mediated bottom- and top-squark production in multijet
  final states in pp collisions at 8 TeV

abstract:
  A search for supersymmetry is presented based on events with large missing
transverse energy, no isolated electron or muon, and at least three jets with
one or more identified as a bottom-quark jet. A simultaneous examination is
performed of the numbers of events in exclusive bins of the scalar sum of jet
transverse momentum values, missing transverse energy, and bottom-quark jet
multiplicity. The sample, corresponding to an integrated luminosity of 19.4
inverse femtobarns, consists of proton-proton collision data recorded at a
center-of-mass energy of 8 TeV with the CMS detector at the LHC in 2012. The
observed numbers of events are found to be consistent with the standard model
expectation, which is evaluated with control samples in data. The results are
interpreted in the context of two simplified supersymmetric scenarios in which
gluino pair production is followed by the decay of each gluino to an undetected
lightest supersymmetric particle and either a bottom or top quark-antiquark
pair, characteristic of gluino mediated bottom- or top-squark production. Using
the production cross section calculated to next-to-leading-order plus
next-to-leading-logarithm accuracy, and in the limit of a massless lightest
supersymmetric particle, we exclude gluinos with masses below 1170 GeV and 1020
GeV for the two scenarios, respectively.


title: Cryptography and Algorithmic Randomness

abstract:
  The secure instantiation of the random oracle is one of the major open
problems in modern cryptography. We investigate this problem using concepts and
methods of algorithmic randomness. In modern cryptography, the random oracle
model is widely used as an imaginary framework in which the security of a
cryptographic scheme is discussed. In the random oracle model, the
cryptographic hash function used in a cryptographic scheme is formulated as a
random variable uniformly distributed over all possibility of the function,
called the random oracle. The main result of this paper is to show that, for
any secure signature scheme in the random oracle model, there exists a specific
computable function which can instantiate the random oracle while keeping the
security originally proved in the random oracle model. In modern cryptography
the generic group model is used also for a similar purpose to the random oracle
model. We show that the same results hold for the generic group model. In the
process of proving the results, we introduce the notion of effective security,
demonstrating the importance of this notion in modern cryptography.


title:
Phase transitions in the two-dimensional super-antiferromagnetic Ising
  model with next-nearest-neighbor interactions

abstract:
  We use Monte Carlo and Transfer Matrix methods in combination with
extrapolation schemes to determine the phase diagram of the 2D
super-antiferromagnetic (SAF) Ising model with next-nearest-neighbor (nnn)
interactions in a magnetic field. The interactions between nearest-neighbor
(nn) spins are ferromagnetic along x, and antiferromagnetic along y. We find
that for sufficiently low temperatures and fields, there exists a region
limited by a critical line of 2nd-order transitions separating a SAF phase from
a magnetically induced paramagnetic phase. We did not find any region with
either first-order transition or with re-entrant behavior. The nnn couplings
produce either an expansion or a contraction of the SAF phase. Expansion occurs
when the interactions are antiferromagnetic, and contraction when they are
ferromagnetic. There is a critical ratio R_c = 1/2 between nnn- and
nn-couplings, beyond which the SAF phase no longer exists.


title: A Riemannian approach to strain measures in nonlinear elasticity

abstract:
  The isotropic Hencky strain energy appears naturally as a distance measure of
the deformation gradient to the set SO(n) of rigid rotations in the canonical
left-invariant Riemannian metric on the general linear group GL(n). Objectivity
requires the Riemannian metric to be left-GL(n)-invariant, isotropy requires
the Riemannian metric to be right-O(n)-invariant. The latter two conditions are
satisfied for a three-parameter family of Riemannian metrics on the tangent
space of GL(n). Surprisingly, the final result is basically independent of the
chosen parameters. In deriving the result, geodesics on GL(n) have to be
parametrized and a novel minimization problem, involving the matrix logarithm
for non-symmetric arguments, has to be solved.


title: Open spin chains for giant gravitons and relativity

abstract:
  We study open spin chains for strings stretched between giant graviton states
in the N=4 SYM field theory in the collective coordinate approach. We study the
boundary conditions and the effective Hamiltonian of the corresponding spin
chain to two loop order.
  The ground states of the spin chain have energies that match the relativistic
dispersion relation characteristic of massive W boson particles on the
worldvolume of the giant graviton configurations, up to second order in the
limit where the momentum is much larger than the mass. We find evidence for a
non-renormalization theorem for the ground state wave function of this spin
chain system. We also conjecture a generalization of this result to all loop
orders which makes it compatible with a fully relativistic dispersion relation.
We show that the conjecture follows if one assumes that the spin chain admits a
central charge extension that is sourced by the giant gravitons, generalizing
the giant magnon dispersion relation for closed string excitations. This
provides evidence for ten dimensional local physics mixing AdS directions and
the five-sphere emerging from an N=4 SYM computation in the presence of a
non-trivial background (made of D-branes) that break the conformal field theory
of the system.


title: Shape Reconstruction and Recognition with Isolated Non-directional Cues

abstract:
  The paper investigates a hypothesis that our visual system groups visual cues
based on how they form a surface, or more specifically triangulation derived
from the visual cues. To test our hypothesis, we compare shape recognition with
three different representations of visual cues: a set of isolated dots
delineating the outline of the shape, a set of triangles obtained from Delaunay
triangulation of the set of dots, and a subset of Delaunay triangles excluding
those outside of the shape. Each participant was assigned to one particular
representation type and increased the number of dots (and consequentially
triangles) until the underlying shape could be identified. We compare the
average number of dots needed for identification among three types of
representations. Our hypothesis predicts that the results from the three
representations will be similar. However, they show statistically significant
differences. The paper also presents triangulation based algorithms for
reconstruction and recognition of a shape from a set of isolated dots.
Experiments showed that the algorithms were more effective and perceptually
agreeable than similar contour based ones. From these experiments, we conclude
that triangulation does affect our shape recognition. However, the surface
based approach presents a number of computational advantages over the contour
based one and should be studied further.


title: Ergodic optimization, zero temperature limits and the max-plus algebra

abstract:
  Lecture notes of a course at the Brazilian Mathematical Colloquium. We review
some basic notions in ergodic theory and thermodynamic formalism, as well as
introductory results in the context of max-plus algebra, in order to exhibit
some properties of equilibrium measures when temperature goes to zero.


title:
A Detailed Comparison Between The Observed and Synthesized Properties of
  a Simulated Type ii Spicule

abstract:
  We performed a 3D radiative MHD simulation of the solar atmosphere. This
simulation shows a jet-like feature that shows similarities to the type II
spicules observed for the first time with Hinode. Rapid Blueshifted Events
(RBEs) on the solar disk are associated with these spicules. Observational
results suggest they may contribute significantly in supplying the corona with
hot plasma. We perform a detailed comparison of the properties of the simulated
jet with those of type II spicules (observed with Hinode) and RBEs (with
ground-based instruments). We analyze variety of synthetic emission and
absorption lines from the simulations including chromospheric Ca II and Ha to
TR and coronal temperatures (10E4 to several 10E6K). We compare their synthetic
intensities, line profiles, Doppler shifts, line widths and asymmetries with
observations from Hinode/SOT and EIS, SOHO/SUMER, SST and SDO/AIA. Many
properties of the synthetic observables resemble the observations, and we
describe in detail the physical processes that lead to these observables.
Detailed analysis of the synthetic observables provides insight into how
observations should be analyzed to derive information about physical variables
in such a dynamic event. For example, we find that LOS superposition in the
optically thin atmosphere requires the combination of Doppler shifts and
spectral line asymmetry to determine the velocity in the jet. Other properties
differ from the observations, especially in the chromospheric lines. The mass
density of the part of the spicule with a chromospheric temperature is too low
to produce significant opacity in chromospheric lines. These and other
discrepancies are described in detail, and we discuss which mechanisms and
physical processes may need to be included in the MHD simulations to mimic the
thermodynamic processes of the chromosphere and corona, in particular to
reproduce type II spicules.