title: Measuring and Predicting Speed of Social Mobilization

abstract:
  Large-scale mobilization of individuals across social networks is becoming
increasingly influential in society. However, little is known about what traits
of recruiters and recruits and affect the speed at which one mobilizes the
other. Here we identify and measure traits of individuals and their
relationships that predict mobilization speed. We ran a global social
mobilization contest and recorded personal traits of the participants and those
they recruited. We identified how those traits corresponded with the speed of
mobilization. Recruits mobilized faster when they first heard about the contest
directly from the contest organization, and decreased in speed when hearing
from less personal source types (e.g. family vs. media). Mobilization was
faster when the recruiter and the recruit heard about the contest through the
same source type, and slower when both individuals were in different countries.
Females mobilized other females faster than males mobilized other males.
Younger recruiters mobilized others faster, and older recruits mobilized
slower. These findings suggest relevant factors for engineering social
mobilization tasks for increased speed.


title: Superconductivity from orbital nematic fluctuations

abstract:
  Recent experiments suggest that besides of antiferromagnetic fluctuations
nematic fluctuations may contribute to the occurrence of superconductivity in
iron pnictides. Motivated by this observation we study superconductivity from
nematic fluctuations in a minimal two-band model. The employed band parameters
are appropriate for iron pnictides and lead to four pockets for the Fermi line.
It is shown that low-energy, long-wavelength nematic fluctuations within the
pockets give rise to strong-coupling superconductivity whereas the large
momenta density fluctuations between pockets are rather irrelevant. The
obtained transition temperatures are similar to those typically found in the
pnictides and are rather robust against repulsive Coulomb interactions. The
superconducting and nematic states coexist in a large region of the phase
diagram.


title: A new class of superregular matrices and MDP convolutional codes

abstract:
  This paper deals with the problem of constructing superregular matrices that
lead to MDP convolutional codes. These matrices are a type of lower block
triangular Toeplitz matrices with the property that all the square submatrices
that can possibly be nonsingular due to the lower block triangular structure
are nonsingular. We present a new class of matrices that are superregular over
a suficiently large finite field F. Such construction works for any given
choice of characteristic of the field F and code parameters (n; k; d) such that
(n-k)|d. Finally, we discuss the size of F needed so that the proposed matrices
are superregular.


title:
The VIMOS Public Extragalactic Redshift Survey (VIPERS). A precise
  measurement of the galaxy stellar mass function and the abundance of massive
  galaxies at redshifts 0.5<z<1.3

abstract:
  We measure the evolution of the galaxy stellar mass function from z=1.3 to
z=0.5 using the first 53,608 redshifts of the ongoing VIMOS Public
Extragalactic Survey (VIPERS). We estimate the galaxy stellar mass function at
several epochs discussing in detail the amount of cosmic variance affecting our
estimate. We find that Poisson noise and cosmic variance of the galaxy mass
function in the VIPERS survey are comparable with the statistical uncertainties
of large surveys in the local universe. VIPERS data allow us to determine with
unprecedented accuracy the high-mass tail of the galaxy stellar mass function,
which includes a significant number of galaxies that are usually too rare to
detect with any of the past spectroscopic surveys. At the epochs sampled by
VIPERS, massive galaxies had already assembled most of their stellar mass. We
apply a photometric classification in the (U-V) rest-frame colour to compute
the mass function of blue and red galaxies, finding evidence for the evolution
of their contribution to the total number density budget: the transition mass
above which red galaxies dominate is found to be about 10^10.4 M_sun at z=0.55
and evolves proportionally to (1+z)^3. We are able to trace separately the
evolution of the number density of blue and red galaxies with masses above
10^11.4 M_sun, in a mass range barely studied in previous work. We find that
for such large masses, red galaxies show a milder evolution with redshift, when
compared to objects at lower masses. At the same time, we detect a population
of similarly massive blue galaxies, which are no longer detectable below z=0.7.
These results show the improved statistical power of VIPERS data, and give
initial promising indications of mass-dependent quenching of galaxies at z~1.
[Abridged]


title:
A local-global principle for isogenies of prime degree over number
  fields

abstract:
  We give a description of the set of exceptional pairs for a number field $K$,
that is the set of pairs $(\ell, j(E))$, where $\ell$ is a prime and $j(E)$ is
the $j$-invariant of an elliptic curve $E$ over $K$ which admits an
$\ell$-isogeny locally almost everywhere but not globally. We obtain an upper
bound for $\ell$ in such pairs in terms of the degree and the discriminant of
$K$. Moreover, we prove finiteness results about the number of exceptional
pairs.


title: Continuous images of Cantor's ternary set

abstract:
  The Hausdorff-Alexandroff Theorem states that any compact metric space is the
continuous image of Cantor's ternary set $C$. It is well known that there are
compact Hausdorff spaces of cardinality equal to that of $C$ that are not
continuous images of Cantor's ternary set. On the other hand, every compact
countably infinite Hausdorff space is a continuous image of $C$. Here we
present a compact countably infinite non-Hausdorff space which is not the
continuous image of Cantor's ternary set.


title: Advanced materials for solid-state refrigeration

abstract:
  Recent progress on caloric effects are reviewed. The application of external
stimuli such as magnetic field, hydrostatic pressure, uniaxial stress and
electric field give rise respectively to magnetocaloric, barocaloric,
elastocaloric and electrocaloric effects. The values of the relevant quantities
such as isothermal entropy and adiabatic temperature-changes are compiled for
selected materials. Large values for these quantities are found when the
material is in the vicinity of a phase transition. Quite often there is
coupling between different degrees of freedom, and the material can exhibit
cross-response to different external fields. In this case, the material can
exhibit either conventional or inverse caloric effects when a field is applied.
The values reported for the many caloric effects at moderate fields are large
enough to envisage future application of these materials in efficient and
environmental friendly refrigeration.


title: Phases of attractive spin-imbalanced fermions in square lattices

abstract:
  We determine the relative stability of different ground-state phases of
spin-imbalanced popula- tions of attractive fermions in square lattices. The
phases are systematically characterized by the symmetry of the order parameter
and the real- and momentum-space structures using Hartree- Fock-Bogoliubov
theory. We find several type of unidirectional Larkin-Ovchinikov-type phases.
We discuss the effect of commensuration between the ordering wave vector and
the density imbalance, and describe the mechanism of Fermi surface
reconstruction and pairing for various orders. A robust supersolid phase is
shown to exist when the ordering wave vector is diagonally directed.


title:
Intersection bodies that are not polar zonoids: A flat top condition in
  dimensions four and six

abstract:
  We find general geometric conditions on a convex body of revolution K, in
dimensions four and six, so that its intersection body IK is not a polar
zonoid. We exhibit several examples of intersection bodies which are are not
polar zonoids.


title:
Broadband second harmonic generation in whispering gallery mode
  resonators

abstract:
  Optical frequency conversion processes in nonlinear materials are limited in
wavelength by the accessible phase matching and the required high pump powers.
In this letter, we report a novel broadband phase matching (PM) technique in
high quality factor (Q) whispering gallery mode (WGM) resonators made of
birefringent crystalline materials. This technique relies on two interacting
WGMs, one with constant and the other with spatially oscillating phase
velocity. Thus, phase matching occurs cyclically. The technique can be
implemented with a WGM resonator with its disk plane parallel to the optic axis
of the crystal. With a single beta barium borate (BBO) resonator in that
configuration, we experimentally demonstrated efficient second harmonic
generation (SHG) to harmonic wavelengths from 780 nm in the near infrared to
317 nm in the ultraviolet (UV). The observed SHG conversion efficiency is as
high as 4.6% (mW)-1. This broadband PM technique opens a new way for nonlinear
optics applications in WGM resonators. This work is also the first reported
continuous wave UV generation by direct SHG in a WGM resonator


title: On the Prediction of the Occurence of dates of GLEs

abstract:
  Ground level enhancements (GLEs) are relativistic sol particles measured at
ground level by a worldwide network of cosmic ray detectors. These sporadic
events are associated with solar flares and are assumed to be of a quasi-random
nature. Their study gives us information about their source and propagation
processes, about the maximum capacity of the sun as a particle accelerator
engine, about the magnetic structure of the medium traversed, etc. Space
vehicles may be damaged by this kind of radiation, as well as electric
transformers and gas pipes at high latitudes. As a result, their prediction has
turned out to be very important, but because of their random occurrence, up to
now few efforts to this end have been made. The results of these efforts have
been limited to possible warnings in real time, just before GLE occurrence, but
no specific dates have been predicted well enough in advance to prevent
possible hazards. In this study we show that, in spite of the quasi-stochastic
nature of GLEs, it is possible to predict them with relative precision, even
for future solar cycles. We reproduce previous GLE events and present results
for future events.


title:
Direct and indirect detection of higgsino-like WIMPs: concluding the
  story of electroweak naturalness

abstract:
  Supersymmetric models which fulfill the conditions of electroweak naturalness
generally contain light higgsinos with mass not too far from m_h ~125 GeV,
while other sparticles can be much heavier. In R-parity conserving models, the
lightest neutralino is then a higgsino-like WIMP (albeit with non-negligible
gaugino components), with thermal relic density well below measured values.
This leaves room for axions to function as co-dark matter particles. The local
WIMP abundance is then expected to be below standard estimates, and direct and
indirect detection rates must be accordingly rescaled. We calculate rescaled
direct and indirect higgsino-like WIMP detection rates in SUSY models that
fulfil the electroweak naturalness condition. In spite of the rescaling, we
find that ton-scale noble liquid detectors can probe the entire higgsino-like
WIMP parameter space, so that these experiments should either discover WIMPs or
exclude the concept of electroweak naturalness in R-parity conserving natural
SUSY models. Prospects for spin-dependent or indirect detection are more
limited due in part to the rescaling effect.


title: An Efficient Hybrid Localization Technique in Wireless Sensor Networks

abstract:
  Sensor nodes are low cost, low power devices that are used to collect
physical data and monitor environmental conditions from remote locations.
Wireless Sensor Networks(WSN) are collection of sensor nodes, coordinating
among themselves to perform a particular task. Localization is defined as the
deployment of the sensor nodes at known locations in the network. Localization
techniques are classified as Centralized and Distributed. MDS-Map and SDP are
some of the centralized algorithms while Diffusion, Gradient,APIT, Bounding
Box, Relaxation-Based and Coordinate System Stitching come under Distributed
algorithms. In this paper, we propose a new hybrid localization technique,
which combines the advantages of the centralized and distributed algorithms and
overcomes some of the drawbacks of the existing techniques. Simulations done
with J-Sim prove advantage of the proposed scheme in terms of localization
error calculated by varying the sink nodes, increasing node density and
increasing communication range.


title: On Self Sustained Photonic Globes

abstract:
  In this paper we consider a classical treatment of a very dense collection of
photons forming a self-sustained globe under its own gravitational influence.
We call this a "photonic globe" We show that such a dense photonic globe will
have a radius closely corresponding to the Schwarzschild radius. Thus lending
substance to the conjuncture that the region within the Schwarzschild radius of
a black hole contains only pure radiation. As an application example, we
consider the case of a very large photonic globe whose radius corresponds to
the radius of the universe and containing radiation of the frequency of the
microwave background (160.2 GHZ). It so turns out that such a photonic globe
has an average density which closely corresponds to the observed average
density of our universe.


title:
Stabilizing a Bell state of two superconducting qubits by dissipation
  engineering

abstract:
  We propose a dissipation engineering scheme that prepares and protects a
maximally entangled state of a pair of superconducting qubits. This is done by
off-resonantly coupling the two qubits to a low-Q cavity mode playing the role
of a dissipative reservoir. We engineer this coupling by applying six
continuous-wave microwave drives with appropriate frequencies. The two qubits
need not be identical. We show that our approach does not require any
fine-tuning of the parameters and requires only that certain ratios between
them be large. With currently achievable coherence times, simulations indicate
that a Bell state can be maintained over arbitrary long times with fidelities
above 94%. Such performance leads to a significant violation of Bell's
inequality (CHSH correlation larger than 2.6) for arbitrary long times.


title: Probing New Physics with the B_s to {\mu}+ {\mu}- Time-Dependent Rate

abstract:
  The B_s to mu+ mu- decay plays an outstanding role in tests of the Standard
Model and physics beyond it. The LHCb collaboration has recently reported the
first evidence for this decay at the 3.5 sigma level, with a branching ratio in
the ballpark of the Standard Model prediction. Thanks to the recently
established sizable decay width difference of the B_s system, another
observable, A^mumu_DeltaGamma, is available, which can be extracted from the
time-dependent untagged B_s to mu+ mu- rate. If tagging information is
available, a CP-violating asymmetry, S_mumu, can also be determined. These two
observables exhibit sensitivity to New Physics that is complementary to the
branching ratio. We define and analyse scenarios in which these quantities
allow us to discriminate between model-independent effective operators and
their CP-violating phases. In this context we classify a selection of popular
New Physics models into the considered scenarios. Furthermore, we consider
specific models with tree-level FCNCs mediated by a heavy neutral gauge boson,
pseudoscalar or scalar, finding striking differences in the predictions of
these scenarios for the observables considered and the correlations among them.
We update the Standard Model prediction for the time-integrated branching ratio
taking the subtle decay width difference effects into account. We find (3.56
+/- 0.18) x 10^-9, and discuss the error budget.


title:
Tuning interaction strength leads to ergodic-nonergodic transition of
  quantum correlations in anisotropic Heisenberg spin model

abstract:
  We investigate the time dynamics of quantum correlations of the anisotropic
Heisenberg model in a time-dependent magnetic field, in one-dimensional,
ladder, and two-dimensional lattices. We find that quantum correlation measures
in the entanglement-separability paradigm are ergodic in these systems
irrespective of system parameters. However, information-theoretic quantum
correlation measures can also be nonergodic, and exhibit a transition from
nonergodic to ergodic behavior with the change of interaction strength in the
direction of the magnetic field. We also observe that the transition point
changes drastically as we go from one-dimensional and ladder lattices to the
two-dimensional one.


title:
Simultaneous extraction of transversity and Collins functions from new
  SIDIS and e+e- data

abstract:
  We present a global re-analysis of the most recent experimental data on
azimuthal asymmetries in semi-inclusive deep inelastic scattering, from the
HERMES and COMPASS Collaborations, and in e+e- --> h_1 h_2 X processes, from
the Belle Collaboration. The transversity and the Collins functions are
extracted simultaneously, in the framework of a revised analysis in which a new
parameterisation of the Collins functions is also tested.


title:
Purely helical absolute equilibria and chirality of (magneto)fluid
  turbulence

abstract:
  Left- and right-handed helical modes' statistical absolute equilibria appear
\textit{separately}. If both chiral sectors present, one can dominate around
its positive pole, which is relevant to the nearly maximally helical (force
free for magnetic field) states of turbulence. Pure magnetodynamics (PMD, or
electron magnetohydrodynamics --- EMHD), pure hydrodynamics (PHD), and,
single-fluid and two-fluid MHDs are studied. Relevant documented data and
issues of cascade properties, and, helical and nonhelical dynamos are
revisited. We also discuss new scenarios, such as PMD inverse magnetic helicity
and forward energy cascades, and, the continuous transition from
completely-inverse to partly-inverse-and-partly-forward and to
completely-forward energy transfers in PHD.


title: Bayesian Seismology of the Sun

abstract:
  We perform a Bayesian grid-based analysis of the solar l=0,1,2 and 3 p modes
obtained via BiSON in order to deliver the first Bayesian asteroseismic
analysis of the solar composition problem. We do not find decisive evidence to
prefer either of the contending chemical compositions, although the revised
solar abundances (AGSS09) are more probable in general. We do find indications
for systematic problems in standard stellar evolution models, unrelated to the
consequences of inadequate modelling of the outer layers on the higher-order
modes. The seismic observables are best fit by solar models that are several
hundred million years older than the meteoritic age of the Sun. Similarly,
meteoritic age calibrated models do not adequately reproduce the observed
seismic observables. Our results suggest that these problems will affect any
asteroseismic inference that relies on a calibration to the Sun.


title:
A linearized kinetic problem on the half-line with collision operator
  from a Bose condensate with excitations

abstract:
  The paper studies a Milne type problem for a linearized quantum Boltzmann
equation. Existence and uniqueness of the solution, together with asymptotic
properties are proven for a given energy flow. The energy flow is proportional
to the asymptotic limit of the mass flow, and the collision frequency is
aymptoticlaly cubic in velocity. The setting differs from the one for the
classical Boltzmann and related equations, where the fluid-dynamic mass flow
along half-line is constant. Here it is no more constant. Instead the study is
based on the energy flow which is no more fluid-dynamic, and on the entropy
flow which differs from the classical case.


title: Characterization of a Thick Ozone Layer in Mars' Past

abstract:
  All three terrestrial planets with atmospheres support O3 layers of some
thickness. While currently only that of Earth is substantial enough to be
climatically significant, we hypothesize that ancient Mars may also have
supported a thick O3 layer during volcanically quiescent periods whenthe
atmosphere was oxidizing. To characterize such an O3 layer and determine the
significance of its fedback on the Martian climate, we apply a 1D line-by-line
radiative-convective model under clear sky conditions coupled to a simple
photochemical model. The parameter space of atmospheric pressure, insolation,
and O2 mixing fraction are explored to find conditions favorable to O3
formation. We find that a substantial O3 layer is most likely for surface
pressures of 0.3-1.0 bar, and could produce an O3 column comparable to that of
modern Earth for O2 mixing fractions approaching 1%. However, even for thinner
O3 layers, significant UV shielding of the surface occurs along with feedback
on both the energy budget and photochemistry of the atmosphere. In particular,
CO2 condensation in the middle atmosphere is inhibited and the characteristics
of H2O dissociation are modified, shifting from a direct photolysis dominated
state similar to modern Mars to a more Earth-like state controlled by O(1D)
attack.


title: Towards a serious games evacuation simulator

abstract:
  The evacuation of complex buildings is a challenge under any circumstances.
Fire drills are a way of training and validating evacuation plans. However,
sometimes these plans are not taken seriously by their participants. It is also
difficult to have the financial and time resources required. In this scenario,
serious games can be used as a tool for training, planning and evaluating
emergency plans. In this paper a prototype of a serious games evacuation
simulator is presented. To make the environment as realistic as possible, 3D
models were made using Blender and loaded onto Unity3D, a popular game engine.
This framework provided us with the appropriate simulation environment. Some
experiences were made and results show that this tool has potential for
practitioners and planners to use it for training building occupants.


title: Using Serious Games to Train Evacuation Behaviour

abstract:
  Emergency evacuation plans and evacuation drills are mandatory in public
buildings in many countries. Their importance is considerable when it comes to
guarantee safety and protection during a crisis. However, sometimes
discrepancies arise between the goals of the plan and its outcomes, because
people find it hard to take them very seriously, or due to the financial and
time resources required. Serious games are a possible solution to tackle this
problem. They have been successfully applied in different areas such as health
care and education, since they can simulate an environment/task quite
accurately, making them a practical alternative to real-life simulations. This
paper presents a serious game developed using Unity3D to recreate a virtual
fire evacuation training tool. The prototype application was deployed which
allowed the validation by user testing. A sample of 30 individuals tested the
evacuating scenario, having to leave the building during a fire in the shortest
time possible. Results have shown that users effectively end up learning some
evacuation procedures from the activity, even if only to look for emergency
signs indicating the best evacuation paths. It was also evidenced that users
with higher video game experience had a significantly better performance.


title:
Renormalization Group on hierarchical lattices in finite dimensional
  disordered Ising and Blume-Emery-Griffiths Models

abstract:
  Renormalization group on hierarchical lattices is often considered a valuable
tool to understand the critical behavior of more complicated statistical
mechanical models. In presence of quenched disorder, however, in many model
cases predictions obtained with the Migdal-Kadanoff bond removal approach fail
to quantitatively and qualitatively reproduce critical properties obtained in
the mean-field approximation or by numerical simulations in finite dimensions.
In order to critically review this limitation we analyze the behavior of Ising
and Blume-Emery-Griffiths models on more complicated hierarchical lattices. We
find that, apart from some exceptions, the different behavior appears not only
limited to Midgal-Kadanoff-like cells but is associated right to the
hierarchization of Bravais lattices in small cells also when in-cell loops are
considered.


title:
Abundances of Suprathermal Heavy Ions in CIRs during the Minimum of
  Solar Cycle 23

abstract:
  In this paper we examine the elemental composition of the 0.1-1 MeV/nucleon
interplanetary heavy ions from H to Fe in corotating interaction regions (CIRs)
measured by the SIT (Suprathermal Ion Telescope) instrument. We use
observations taken on board the STEREO spacecraft from January 2007 through
December 2010, which included the unusually long solar minimum following solar
cycle 23. During this period instruments on STEREO observed more than 50 CIR
events making it possible to investigate CIR ion abundances during solar
minimum conditions with unprecedented high statistics. The observations reveal
annual variations of relative ion abundances in the CIRs during the 2007-2008
period as indicated by the He/H, He/O and Fe/O elemental ratios. We discuss
possible causes of the variability in terms of the helium focusing cone passage
and heliolatitude dependence. The year 2009 was very quiet in CIR event
activity. In 2010 the elemental composition in CIRs were influenced by sporadic
solar energetic particle (SEP) events. The 2010 He/H and He/O abundance ratios
in CIRs show large event to event variations with values resembling the
SEP-like composition. This finding points out that the suprathermal SEPs could
be the source population for CIR acceleration.


title:
Radiation induced electronic trap states and local structural disorder
  in van~der~Waals bonded semiconductor crystals

abstract:
  In controlled X-ray irradiation experiments, the formation of trap states in
the prototypical van der Waals bonded semiconductor Rubrene is studied
quantitatively for doses up to 82 Gy (Gy = J/kg). About 100 electronic trap
states, located around 0.3 eV above the valence band, are created by each
absorbed 8 keV photon which is 2-3 orders of magnitude more than 1 MeV protons
produce. Thermal annealing is shown to reduce these traps. Local structural
disorder, which has also been induced by other means in different studies, is
thus identified as a common origin of trap states in van der Waals bonded
molecular organic semiconductors.


title:
Cavity-QED of a leaky planar resonator coupled to an atom and an input
  single-photon pulse

abstract:
  In contrast to the free-space evolution of an atom governed by a multi-mode
interaction with the surrounding electromagnetic vacuum, the evolution of a
cavity-QED system can be characterized by just three parameters, (i)
atom-cavity coupling strength g, (ii) cavity relaxation rate \kappa, and (iii)
atomic decay rate into the non-cavity modes \gamma. In the case of an atom
inserted into a planar resonator with an input beam coupled from the outside,
it has been shown by Koshino [Phys. Rev. A 73, 053814 (2006)] that these three
parameters are determined not only by the atom and cavity characteristics, but
also by the spatial distribution of the input pulse. By an ab-initio treatment,
we generalize the framework of Koshino and determine the cavity-QED parameters
of a coupled system of atom, planar (leaky) resonator, and input single-photon
pulse as functions of the lateral profile of the pulse and the length of
resonator. We confirm that the atomic decay rate can be suppressed by tailoring
appropriately the lateral profile of the pulse. Such an active suppression of
atomic decay opens an attractive route towards an efficient quantum memory for
long-term storage of an atomic qubit inside a planar resonator.


title: Higgs decay into diphoton in the Composite Higgs Model

abstract:
  We explore the Higgs couplings to gauge bosons in the minimal $SO(5)/SO(4)$
4D composite Higgs model. The pions scatterings put unitary constraints on the
couplings and therefore determine the branch ratios of various Higgs decays.
Through fine tuning the parameters, enhancement of Higgs to diphoton rate is
possible to be achieved with the existence of vector meson fields.


title:
Towards modeling quasi-periodic oscillations of microquasars with
  oscillating slender tori

abstract:
  Context. One of the often discussed models for X-ray binaries high-frequency
quasi-periodic oscillations is the oscillating torus model that considers
oscillation modes of slender accretion tori. Aims. Here, we aim at developing
this model by considering the observable signature of an optically thick
slender accretion torus subject to simple periodic deformations. Methods. We
compute light curves and power spectra of a slender accretion torus subject to
simple periodic deformations: vertical or radial translation, rotation,
expansion and shear. Results. We show that different types of deformations lead
to very different Fourier power spectra and therefore could be observationally
distinguished. Conclusions. This work is a first step in a longer-term study of
the observable characteristics of the oscillating torus model. It gives
promising perspectives on the possibility to constrain this model by studying
the observed power spectra of quasi-periodic oscillations.


title:
Chromium-doped silica optical fibres : influence of the core composition
  on the Cr oxidation states and crystal field

abstract:
  We have made chromium-doped, silica-based preforms and optical fibres by
Modified Chemical Vapour Deposition and have studied the influence of the
chemical composition of the doped region on the Cr-oxidation states and the
spectroscopic properties of the samples. Chromium, introduced initially as
Cr3+, is partially or totally oxidized during the fabrication process, and is
stabilized in the core of the preforms and fibres as Cr3+ in octahedral
coordination, and/or as Cr4+ in distorded tetrahedral coordination (Cs). Small
concentrations (~1-2 mol%) of codopants in silica, such as germanium or
aluminium, suffice to promote a particular oxidation state. Particularly, 1 mol
% of aluminium stabilizes all present chromium into Cr4+. The ligand field
parameters, Dq, B and Dq/B, for Cr3+ and Cr4+ are derived. It is shown that the
chromium ions in our samples are in low to intermediate ligand field and that
Dq and Dq/B decrease when the aluminium content increases. The absorption cross
sections of Cr3+ are similar to that reported in glasses and crystals, whereas
Cr4+ has lower values than reference laser materials.


title: Asymptotic properties of some minor-closed classes of graphs

abstract:
  Let A be a minor-closed class of labelled graphs, and let G_n be a random
graph sampled uniformly from the set of n-vertex graphs of A. When n is large,
what is the probability that G_n is connected? How many components does it
have? How large is its biggest component? Thanks to the work of McDiarmid and
his collaborators, these questions are now solved when all excluded minors are
2-connected. Using exact enumeration, we study a collection of classes A
excluding non-2-connected minors, and show that their asymptotic behaviour may
be rather different from the 2-connected case. This behaviour largely depends
on the nature of dominant singularity of the generating function C(z) that
counts connected graphs of A. We classify our examples accordingly, thus taking
a first step towards a classification of minor-closed classes of graphs.
Furthermore, we investigate a parameter that has not received any attention in
this context yet: the size of the root component. It follows non-gaussian limit
laws (beta and gamma), and clearly deserves a systematic investigation.


title: Tests against noncontextual models with measurement disturbances

abstract:
  The testability of the Kochen-Specker theorem is a subject of ongoing
controversy. A central issue is that experimental implementations relying on
sequential measurements cannot achieve perfect compatibility between the
measurements and that therefore the notion of noncontextuality is not well
defined. We demonstrate by an explicit model that such compatibility violations
may yield a violation of noncontextuality inequalities, even if we assume that
the incompatibilities merely originate from context-independent noise. We show,
however, that this problem can be circumvented by combining the ideas behind
Leggett-Garg inequalities with those of the Kochen-Specker theorem.


title:
One-Dimensional Quantum Confinement Effect Modulated Thermoelectric
  Properties in InAs Nanowires

abstract:
  We report electrical conductance and thermopower measurements on InAs
nanowires synthesized by chemical vapor deposition. Gate modulation of the
thermopower of individual InAs nanowires with diameter around 20nm is obtained
over T=40 to 300K. At low temperatures (T< ~100K), oscillations in the
thermopower and power factor concomitant with the stepwise conductance
increases are observed as the gate voltage shifts the chemical potential of
electrons in InAs nanowire through quasi-one-dimensional (1D) sub-bands. This
work experimentally shows the possibility to modulate semiconductor nanowire's
thermoelectric properties through the peaked 1D electronic density of states in
the diffusive transport regime, a long-sought goal in nanostructured
thermoelectrics research. Moreover, we point out the importance of scattering
(or disorder) induced energy level broadening in smearing out the 1D
confinement enhanced thermoelectric power factor at practical temperatures
(e.g. 300K).


title: Localized Features in Non-Gaussianity from Heavy Physics

abstract:
  We discuss the possibility that we could obtain some hints of the heavy
physics during inflation by analyzing local features of the primordial
bispectrum. A heavy scalar field could leave large signatures in the primordial
spectra through the parametric resonance between its background oscillation and
the fluctuations. Since the duration of the heavy-mode oscillations is finite,
the effect of the resonance is localized in momentum space. In this paper, we
show that the bispectrum is amplified when such a resonance occurs, and that
the peak amplitude of the feature can be O(10^{1-2}), or as large as O(10^5)
depending on the type of interactions. In particular, the resonance can give
large contributions in finitely squeezed configurations, while the bispectrum
cannot be large in the exact squeezed limit. We also find that there is a
relation between the scales at which the features appear in the bispectrum and
the power spectrum, and that the feature in the bispectrum can be much larger
than that in the power spectrum. If correlated features are observed at
characteristic scales in the primordial spectra, it will indicate the presence
of heavy degrees of freedom. By analyzing these features, we may be able to
obtain some information on the physics behind inflation.


title:
Two-dimensional short-range interacting attractive and repulsive Fermi
  gases at zero temperature

abstract:
  We study a two-dimensional two-component Fermi gas with attractive or
repulsive short-range interactions at zero temperature. We use Diffusion Monte
Carlo with Fixed Node approximation in order to calculate the energy per
particle and the opposite-spin pair distribution functions. We show the
relevance of beyond mean field effects and verify the consistency of our
approach by using Tan's Contact relations.


title: Evolution of Planetary Systems with Time Dependent Stellar Mass Loss

abstract:
  Observations indicate that intermediate mass stars, binary stars, and stellar
remnants often host planets; a complete explanation of these systems requires
an understanding of how planetary orbits evolve as their central stars lose
mass. Motivated by these dynamical systems, this paper generalizes in two
directions previous studies of orbital evolution in planetary systems with
stellar mass loss: [1] Many previous treatments focus on constant mass loss
rates and much of this work is carried out numerically. Here we study a class
of single planet systems where the stellar mass loss rate is time dependent.
The mass loss rate can be increasing or decreasing, but the stellar mass always
decreases monotonically. For this class of models, we develop analytic
approximations to specify the final orbital elements for planets that remain
bound after the epoch of mass loss, and find the conditions required for the
planets to become unbound. We also show that for some mass loss functions,
planets become unbound only in the asymptotic limit where the stellar mass
vanishes. [2] We consider the chaotic evolution for two planet systems with
stellar mass loss. Here we focus on a model consisting of analogs of Jupiter,
Saturn, and the Sun. By monitoring the divergence of initially similar
trajectories through time, we calculate the Lyapunov exponents of the system.
This analog solar system is chaotic in the absence of mass loss with Lyapunov
time in the range 5 - 10 Myr; we find that the Lyapunov time decreases with
increasing stellar mass loss rate, with a nearly linear relationship between
the two time scales. Taken together, the results of this paper help provide an
explanation for a wide range of dynamical evolution that occurs in solar
systems with stellar mass loss.


title:
Antibiotic resistance landscapes: a quantification of theory-data
  incompatibility for fitness landscapes

abstract:
  Fitness landscapes are central in analyzing evolution, in particular for drug
resistance mutations for bacteria and virus. We show that the fitness
landscapes associated with antibiotic resistance are not compatible with any of
the classical models; additive, uncorrelated and block fitness landscapes. The
NK model is also discussed. It is frequently stated that virtually nothing is
known about fitness landscapes in nature. We demonstrate that available records
of antimicrobial drug mutations can reveal interesting properties of fitness
landscapes in general. We apply the methods to analyze the TEM family of
$\beta$-lactamases associated with antibiotic resistance. Laboratory results
agree with our observations. The qualitative tools we suggest are well suited
for comparisons of empirical fitness landscapes. Fitness landscapes are central
in the theory of recombination and there is a potential for finding relations
between the tools and recombination strategies.


title:
Universality of the three-body Efimov parameter at narrow Feshbach
  resonances

abstract:
  We measure the critical scattering length for the appearance of the first
three-body bound state, or Efimov three-body parameter, at seven different
Feshbach resonances in ultracold 39K atoms. We study both intermediate and
narrow resonances, where the three-body spectrum is expected to be determined
by the non-universal coupling of two scattering channels. We observe instead
approximately the same universal relation of the three-body parameter with the
two-body van der Waals radius already found for broader resonances, which can
be modeled with a single channel. This unexpected observation suggests the
presence of a new regime for three-body scattering at narrow resonances.


title:
Low-Complexity Channel Estimation with Set-Membership Algorithms for
  Cooperative Wireless Sensor Networks

abstract:
  In this paper, we consider a general cooperative wireless sensor network
(WSN) with multiple hops and the problem of channel estimation. Two
matrix-based set-membership algorithms are developed for the estimation of the
complex matrix channel parameters. The main goal is to reduce the computational
complexity significantly as compared with existing channel estimators and
extend the lifetime of the WSN by reducing its power consumption. The first
proposed algorithm is the set-membership normalized least mean squares
(SM-NLMS) algorithm. The second is the set-membership recursive least squares
(RLS) algorithm called BEACON. Then, we present and incorporate an error bound
function into the two channel estimation methods which can adjust the error
bound automatically with the update of the channel estimates. Steady-state
analysis in the output mean-squared error (MSE) are presented and closed-form
formulae for the excess MSE and the probability of update in each recursion are
provided. Computer simulations show good performance of our proposed algorithms
in terms of convergence speed, steady state mean square error and bit error
rate (BER) and demonstrate reduced complexity and robustness against the
time-varying environments and different signal-to-noise ratio (SNR) values.


title:
Unique heavy lepton signature at $e^+e^-$ linear collider with polarized
  beams

abstract:
  We explore the effects of neutrino and electron mixing with exotic heavy
leptons in the process e^+e^-\to W^+W^- within E_6 models. We examine the
possibility of uniquely distinguishing and identifying such effects of heavy
neutral lepton exchange from Z-Z' mixing within the same class of models and
also from analogous ones due to competitor models with anomalous trilinear
gauge couplings (AGC) that can lead to very similar experimental signatures at
the e^+e^- International Linear Collider (ILC) for \sqrt{s}=350, 500 GeV and 1
TeV. Such clear identification of the model is possible by using a certain
double polarization asymmetry. The availability of both beams being polarized
plays a crucial role in identifying such exotic-lepton admixture. In addition,
the sensitivity of the ILC for probing exotic-lepton admixture is substantially
enhanced when the polarization of the produced W^\pm bosons is considered.


title:
Ambipolar Surface Conduction in Ternary Topological Insulator
  Bi_2(Te_{1-x}Se_x)_3 Nanoribbons

abstract:
  We report the composition and gate voltage induced tuning of transport
properties in chemically synthesized Bi2(Te1-xSex)3 nanoribbons. It is found
that increasing Se concentration effectively suppresses the bulk carrier
transport and induces semiconducting behavior in the temperature dependent
resistance of Bi2(Te1-xSex)3 nanoribbons when x is greater than ~10%. In
Bi2(Te1-xSex)3 nanoribbons with x ~20%, gate voltage enables ambipolar
modulation of resistance (or conductance) in samples with thickness around or
larger than 100nm, indicating significantly enhanced contribution in transport
from the gapless surface states.


title:
Cubic-scaling algorithm and self-consistent field for the random-phase
  approximation with second-order screened exchange

abstract:
  The random-phase approximation with second-order screened exchange
(RPA+SOSEX) is a model of electron correlation energy with two caveats: its
accuracy depends on an arbitrary choice of mean field, and it scales as
$\mathcal{O}(n^5)$ operations and $\mathcal{O}(n^3)$ memory for $n$ electrons.
We derive a new algorithm that reduces its scaling to $\mathcal{O}(n^3)$
operations and $\mathcal{O}(n^2)$ memory using controlled approximations and a
new self-consistent field that approximates Brueckner coupled-cluster doubles
(BCCD) theory with RPA+SOSEX, referred to as Brueckner RPA (BRPA) theory. The
algorithm comparably reduces the scaling of second-order
M$\mathrm{{\o}}$ller-Plesset (MP2) perturbation theory with smaller cost
prefactors than RPA+SOSEX. Within a semiempirical model, we study H$_2$
dissociation to test accuracy and H$_n$ rings to verify scaling.


title: Semiclassical wavefunctions for open quantum billiards

abstract:
  We present a semiclassical approximation to the scattering wavefunction
$\Psi(\mathbf{r},k)$ for an open quantum billiard which is based on the
reconstruction of the Feynman path integral. We demonstrate its remarkable
numerical accuracy for the open rectangular billiard and show that the
convergence of the semiclassical wavefunction to the full quantum state is
controlled by the path length or equivalently the dwell time. Possible
applications include leaky billiards and systems with decoherence present.


title:
Joint Maximum Sum-Rate Receiver Design and Power Adjustment for Multihop
  Wireless Sensor Networks

abstract:
  In this paper, we consider a multihop wireless sensor network (WSN) with
multiple relay nodes for each hop where the amplify-and-forward (AF) scheme is
employed. We present a strategy to jointly design the linear receiver and the
power allocation parameters via an alternating optimization approach that
maximizes the sum rate of the WSN. We derive constrained maximum sum-rate (MSR)
expressions along with an algorithm to compute the linear receiver and the
power allocation parameters with the optimal complex amplification coefficients
for each relay node. Computer simulations show good performance of our proposed
methods in terms of sum rate compared to the method with equal power
allocation.


title: Unconventional Magnetic Ground State in Yb$_2$Ti$_2$O$_7$

abstract:
  We report low temperature specific heat and muon spin relaxation/rotation
($\mu$SR) measurements on both polycrystalline and single crystal samples of
the pyrochlore magnet Yb$_2$Ti$_2$O$_7$. This system is believed to possess a
spin Hamiltonian supporting a Quantum Spin Ice (QSI) ground state and to
display sample variation in its low temperature heat capacity. Our two samples
exhibit extremes of this sample variation, yet our $\mu$SR measurements
indicate a similar disordered low temperature state down to 16 mK in both. We
report little temperature dependence to the spin relaxation and no evidence for
ferromagnetic order, in contrast to recent reports by Chang \emph{et al.} (Nat.
Comm. {\bf 3}, 992 (2012)). Transverse field (TF) $\mu$SR measurements show
changes in the temperature dependence of the muon Knight shift which coincide
with heat capacity anomalies. We are therefore led to propose that
Yb$_2$Ti$_2$O$_7$ enters a hidden order ground state below $T_c\sim265$ mK
where the nature of the ordered state is unknown but distinct from simple long
range order.


title: Metal-Insulator Transition in Variably Doped (Bi1-xSbx)2Se3 Nanosheets

abstract:
  Topological insulators are novel quantum materials with metallic surface
transport, but insulating bulk behavior. Often, topological insulators are
dominated by bulk contributions due to defect induced bulk carriers, making it
difficult to isolate the more interesting surface transport characteristics.
Here, we report the synthesis and characterization of nanosheets of topological
insulator Bi2Se3 with variable Sb-doping level to control the electron carrier
density and surface transport behavior. (Bi1-xSbx)2Se3 thin films of thickness
less than 10 nm are prepared by epitaxial growth on mica substrates in a vapor
transport setup. The introduction of Sb in Bi2Se3 effectively suppresses the
room temperature electron density from ~4 \times 10^13/cm^2 in pure Bi2Se3 (x =
0) to ~2 \times 10^12/cm^2 in (Bi1-xSbx)2Se3 at x ~0.15, while maintaining the
metallic transport behavior. At x > ~0.20, a metal-insulator transition (MIT)
is observed indicating that the system has transformed into an insulator in
which the metallic surface conduction is blocked. In agreement with the
observed MIT, Raman spectroscopy reveals the emergence of vibrational modes
arising from Sb-Sb and Sb-Se bonds at high Sb concentrations, confirming the
appearance of Sb2Se3 crystal structure in the sample. These results suggest
that nanostructured chalcogenide films with controlled doping can be a tunable
platform for fundamental studies and electronic applications of topological
insulator systems.


title: Intervals and factors in the Bruhat order

abstract:
  In this paper we study those generic intervals in the Bruhat order of the
symmetric group that are isomorphic to the principal order ideal of a
permutation w, and consider when the minimum and maximum elements of those
intervals are related by a certain property of their reduced words. We show
that the property does not hold when w is a decomposable permutation, and that
the property always holds when w is the longest permutation.


title: Reduction Theorems for the Strong Real Jacobian Conjecture

abstract:
  Implementations of known reductions of the Strong Real Jacobian Conjecture
(SRJC), to the case of an identity map plus cubic homogeneous or cubic linear
terms, and to the case of gradient maps, are shown to preserve significant
algebraic and geometric properties of the maps involved. That permits the
separate formulation and reduction, though not so far the solution, of the SRJC
for classes of nonsingular polynomial endomorphisms of real n-space that
exclude the Pinchuk counterexamples to the SRJC, for instance those that induce
rational function field extensions of a given fixed odd degree.


title:
Applications of baryon chiral perturbation theory. A topical example:
  The nucleon sigma terms

abstract:
  We present an overview of modern approaches to low-energy baryon structure
based on baryon chiral perturbation theory. These are driven by the emergence
of Lorentz covariant schemes and the systematic consideration of the effects of
the lowest-lying decuplet resonances. In order to illustrate the progress
recently achieved in this field, we present the last developments on our
understanding of the nucleon sigma terms along these lines. In particular, we
will show how these methods, in SU(2) or SU(3) settings, are reliable tools to
process and maximize the information on the physical structure of the nucleon
one can obtain from either experimental data or lattice QCD results.


title: Grasping Complexity

abstract:
  The century of complexity has come. The face of science has changed.
Surprisingly, when we start asking about the essence of these changes and then
critically analyse the answers, the result are mostly discouraging. Most of the
answers are related to the properties that have been in the focus of scientific
research already for more than a century (like non-linearity). This paper is
Preface to the special issue "Grasping Complexity" of the journal "Computers
and Mathematics with Applications". We analyse the change of era in science,
its reasons and main changes in scientific activity and give a brief review of
the papers in the issue.


title:
Direct measurement of the upper critical field in a cuprate
  superconductor

abstract:
  The upper critical field Hc2 is a fundamental measure of the pairing
strength, yet there is no agreement on its magnitude and doping dependence in
cuprate superconductors. We have used thermal conductivity as a direct probe of
Hc2 in the cuprates YBa2Cu3Oy and YBa2Cu4O8 to show that there is no vortex
liquid at T = 0, allowing us to use high-field resistivity measurements to map
out the doping dependence of Hc2 across the phase diagram. Hc2(p) exhibits two
peaks, each located at a critical point where the Fermi surface undergoes a
transformation. The condensation energy obtained directly from Hc2, and
previous Hc1 data, undergoes a 20-fold collapse below the higher critical
point. These data provide quantitative information on the impact of competing
phases in suppressing superconductivity in cuprates.


title: The number of {1243, 2134}-avoiding permutations

abstract:
  We show that the counting sequence for permutations avoiding both of the
(classical) patterns 1243 and 2134 has the algebraic generating function
supplied by Vaclav Kotesovec for sequence A164651 in The On-Line Encyclopedia
of Integer Sequences.


title: Scintillation of Liquid Helium for Low-Energy Nuclear Recoils

abstract:
  The scintillation properties of liquid helium upon the recoil of a low energy
helium atom are discussed in the context of the possible use of this medium as
a detector of dark matter. It is found that the prompt scintillation yield in
the range of recoil energies from a few keV to 100 keV is somewhat higher than
that obtained by a linear extrapolation from the measured yield for an 5 MeV
alpha particle. A comparison is made of both the scintillation yield and the
charge separation by an electric field for nuclear recoils and for electrons
stopped in helium.


title:
Nuclear spin polarization in a single quantum dot pumped by two laser
  beams

abstract:
  We theoretically investigate dynamic nuclear spin polarization in a
self-assembled quantum dot pumped optically by two laser beams. With the
assumption that a noncollinear interaction between the hole spin and nuclear
spins leads to nuclear spin polarization, we find that both weak and strong
nuclear spin polarizations can arise, depending on the intensities and central
frequencies of the lasers. For weak nuclear spin polarization, we use a
perturbation method to show that the distribution of the nuclear spin
Overhauser field may become significantly narrower. Using Monte Carlo
simulations to study a single quantum dot, we find that strong nuclear spin
polarization can also be generated via appropriate optical pumping.


title:
Inducing spin-correlations and entanglement in a double quantum dot
  through non-equilibrium transport

abstract:
  For a double quantum dot system in a parallel geometry, we demonstrate that
by combining the effects of a flux and driving an electrical current through
the structure, the spin correlations between electrons localized in the dots
can be controlled at will. In particular, a current can induce spin
correlations even if the spins are uncorrelated in the initial equilibrium
state. Therefore, we are able to engineer an entangled state in this double-dot
structure. We take many-body correlations fully into account by simulating the
real-time dynamics using the time-dependent density matrix renormalization
group method. Using a canonical transformation, we provide an intuitive
explanation for our results, related to Ruderman-Kittel-Kasuya-Yoshida physics
driven by the bias.


title:
Generation of quantum entanglement between three level atoms via $n$
  coupled cavities

abstract:
  Based on two-photon exchange interaction between $n$ coupled optical cavities
each of them containing a single three level atom, the $n$-qubit and
$n$-photonic state transfer is investigated. In fact, following the approach of
Ref.\cite{Alex1}, we consider $n$ coupled cavities instead of two cavities and
generalize the discussions about quantum state transfer, photon transition
between cavities and entanglement generations between $n$ atoms. More clearly,
by employing the consistency of number of photons (the symmetry of
Hamiltonian), the hamiltonian of the system is reduced from $3^n$ dimensional
space into 2n dimensional one. Moreover, by introducing suitable basis for the
atom-cavity state space based on Fourier transform, the reduced Hamiltonian is
block-diagonalized, with 2 dimensional blocks. Then, the initial state of the
system is evolved under the corresponding Hamiltonian and the suitable times
$T$ at which the initially unentangled atoms, become maximally entangled, are
determined in terms of the hopping strength $\xi$ between cavities.


title: What is the relativistic spin operator?

abstract:
  Although the spin is regarded as a fundamental property of the electron,
there is no universally accepted spin operator within the framework of
relativistic quantum mechanics. We investigate the properties of different
proposals for a relativistic spin perator. It is shown that most candidates are
lacking essential features of proper angular momentum operators, leading to
spurious Zitterbewegung (quivering motion) or violating the angular momentum
algebra. Only the Foldy-Wouthuysen operator and the Pryce operator qualify as
proper relativistic spin operators. We demonstrate that ground states of highly
charged hydrogen-like ions can be utilized to identify a legitimate
relativistic spin operator experimentally.


title:
The Improved Measurement of Electron-antineutrino Disappearance at Daya
  Bay

abstract:
  With 2.5x the previously reported exposure, the Daya Bay experiment has
improved the measurement of the neutrino mixing parameter sin^2(2theta_13) =
0.089+-0.010(stat)+-0.005(syst). Reactor anti-neutrinos were produced by six
2.9 GW(th) commercial power reactors, and measured by six 20-ton target-mass
detectors of identical design. A total of 234,217 anti-neutrino candidates were
detected in 127 days of exposure. An anti-neutrino rate of
0.944+-0.007(stat)+-0.003(syst) was measured by three detectors at a
flux-weighted average distance of 1648 m from the reactors, relative to two
detectors at 470 m and one detector at 576 m. Detector design and depth
underground limited the background to 5+-0.3% (far detectors) and 2+-0.2% (near
detectors) of the candidate signals. The improved precision confirms the
initial measurement of reactor anti-neutrino disappearance, and continues to be
the most precise measurement of theta_13.


title: Reaction dynamics through kinetic transition states

abstract:
  The transformation of a system from one state to another is often mediated by
a bottleneck in the system's phase space. In chemistry these bottlenecks are
known as \emph{transition states} through which the system has to pass in order
to evolve from reactants to products. The chemical reactions are usually
associated with configurational changes where the reactants and products states
correspond, e.g., to two different isomers or the undissociated and dissociated
state of a molecule or cluster. In this letter we report on a new type of
bottleneck which mediates \emph{kinetic} rather than configurational changes.
The phase space structures associated with such \emph{kinetic transition
states} and their dynamical implications are discussed for the rotational
vibrational motion of a triatomic molecule. An outline of more general related
phase space structures with important dynamical implications is given.


title:
Tuning the static spin-stripe phase and superconductivity in
  La_(2-x)Ba_xCuO_4 (x = 1/8) by hydrostatic pressure

abstract:
  Magnetization and muon spin rotation experiments were performed in
La_(2-x)Ba_xCuO_4 (x = 1/8) as a function of hydrostatic pressure up to p = 2.2
GPa. It was found that the magnetic volume fraction of the static stripe phase
strongly decreases linearly with pressure, while the superconducting volume
fraction increases by the same amount. This demonstrates competition between
bulk superconductivity and static magnetic order in the stripe phase of
La_1.875Ba_0.125CuO_4 and that these phenomena occur in mutually exclusive
spatial regions. The present results also reveal that the static spin-stripe
phase still exists at pressures, where the long-range low-temperature
tetragonal (LTT) structure is completely suppressed. This indicates that the
long-range LTT structure is not necessary for stabilizing the static spin order
in La_1.875Ba_0.125CuO_4.


title:
Variational Semi-blind Sparse Deconvolution with Orthogonal Kernel Bases
  and its Application to MRFM

abstract:
  We present a variational Bayesian method of joint image reconstruction and
point spread function (PSF) estimation when the PSF of the imaging device is
only partially known. To solve this semi-blind deconvolution problem, prior
distributions are specified for the PSF and the 3D image. Joint image
reconstruction and PSF estimation is then performed within a Bayesian
framework, using a variational algorithm to estimate the posterior
distribution. The image prior distribution imposes an explicit atomic measure
that corresponds to image sparsity. Importantly, the proposed Bayesian
deconvolution algorithm does not require hand tuning. Simulation results
clearly demonstrate that the semi-blind deconvolution algorithm compares
favorably with previous Markov chain Monte Carlo (MCMC) version of myopic
sparse reconstruction. It significantly outperforms mismatched non-blind
algorithms that rely on the assumption of the perfect knowledge of the PSF. The
algorithm is illustrated on real data from magnetic resonance force microscopy
(MRFM).


title: A Survey for Planetary Nebulae in M31 Globular Clusters

abstract:
  We report the results of an [O III] 5007 spectroscopic survey for planetary
nebulae (PNe) located within the star clusters of M31. By examining R ~ 5000
spectra taken with the WIYN+Hydra spectrograph, we identify 3 PN candidates in
a sample of 274 likely globular clusters, 2 candidates in objects which may be
globular clusters, and 5 candidates in a set of 85 younger systems. The
possible PNe are all faint, between ~2.5 and ~6.8 mag down the PN luminosity
function, and, partly as a consequence of our selection criteria, have high
excitation, with [O III] 5007 to H-beta ratios ranging from 2 to ~12. We
discuss the individual candidates, their likelihood of cluster membership, and
the possibility that they were formed via binary interactions within the
clusters. Our data are consistent with the suggestion that PN formation within
globular clusters correlates with binary encounter frequency, though, due to
the small numbers and large uncertainties in the candidate list, this study
does not provide sufficient evidence to confirm the hypothesis.


title: Spatial extent of an outbreak in animal epidemics

abstract:
  Characterizing the spatial extent of epidemics at the outbreak stage is key
to controlling the evolution of the disease. At the outbreak, the number of
infected individuals is typically small, so that fluctuations around their
average are important: then, it is commonly assumed that the
susceptible-infected-recovered (SIR) mechanism can be described by a stochastic
birth-death process of Galton-Watson type. The displacements of the infected
individuals can be modelled by resorting to Brownian motion, which is
applicable when long-range movements and complex network interactions can be
safely neglected, as in case of animal epidemics. In this context, the spatial
extent of an epidemic can be assessed by computing the convex hull enclosing
the infected individuals at a given time. We derive the exact evolution
equations for the mean perimeter and the mean area of the convex hull, and
compare them with Monte Carlo simulations.


title: Enhancing the Figure of Merit in Te-doped FeSb2 through nanostructuring

abstract:
  We study the thermoelectric properties of Te-doped FeSb2 nanostructured
samples. Four samples of stoichiometry FeSb1.84Te0.16 were prepared by a hot
press method at temperatures of 200, 400, 500, and 600 oC. Te-doping enhances
the dimensionless figure of merit (ZT) on FeSb2 via two mechanisms. First, a
semiconductor to metal transition is induced, which enhances the value of the
power factor at low-temperatures. Second, the thermal conductivity, which was
already reduced in nanostructured FeSb2 samples, is further reduced by
increased point defect scattering through the n type substitution of Sb site by
Te atom. The combined effect results in a ZT = 0.022 at 100 K, an increase of
62% over the ZT value for the optimized Te-doped single crystal sample. Hall
coefficient and electrical resistivity measurements reveal a decreased mobility
and increased concentration of the carriers in the doped sample.


title: Higgs Inflation in f(\Phi,R) Theory

abstract:
  We generalize the scalar-curvature coupling model ${\xi \Phi^2 R}$ of Higgs
inflation to $ {\xi \Phi^a R^b} $ to study inflation.
  We compute the amplitude and spectral index of curvature perturbations
generated during inflation and fix the parameters of the model by comparing
these with the Planck$+$WP data. We find that if the scalar self coupling
$\lambda$ is in the range $(10^{-5}-0.1)$, parameter $a$ in the range $(2.3
-3.6)$ and $b$ in the range $(0.77-0.22)$ at the Planck scale, one can have a
viable inflation model even for $\xi \simeq 1$. The tensor to scalar ratio $r$
in this model is small and our model with scalar-curvature couplings is not
ruled out by observational limits on $r$ unlike the pure $\frac{\lambda}{4}
\Phi^4$ theory. By requiring the curvature coupling parameter to be of order
unity, we have evaded the problem of unitarity violation in scalar-graviton
scatterings which plague the $\xi \Phi^2 R$ Higgs inflation models.
  We conclude that the Higgs field may still be a good candidate for being the
inflaton in the early universe if one considers higher dimensional curvature
coupling.


title:
A Measurement of Atomic X-ray Yields in Exotic Atoms and Implications
  for an Antideuteron-Based Dark Matter Search

abstract:
  The General AntiParticle Spectrometer (GAPS) is a novel approach for the
indirect dark matter search that exploits cosmic antideuterons. GAPS utilizes a
distinctive detection method using atomic X-rays and charged particles from the
exotic atom as well as the timing, stopping range and dE/dX energy deposit of
the incoming particle, which provides excellent antideuteron identification. In
anticipation of a future balloon experiment, an accelerator test was conducted
in 2004 and 2005 at KEK, Japan, in order to prove the concept and to precisely
measure the X-ray yields of antiprotonic exotic atoms formed with different
target materials [1]. The X-ray yields of the exotic atoms with Al and S
targets were obtained as ~ 75%, which are higher than were previously assumed
in [2]. A simple, but comprehensive cascade model has been developed not only
to evaluate the measurement results but also to predict the X-ray yields of the
exotic atoms formed with any materials in the GAPS instrument. The cascade
model is extendable to any kind of exotic atom (any negatively charged
cascading particles with any target materials), and it was compared and
validated with other experimental data and cascade models for muonic and
antiprotonic exotic atoms. The X-ray yields of the antideuteronic exotic atoms
are predicted with a simple cascade model and the sensitivity for the GAPS
antideuteron search was estimated for the proposed long duration balloon
program [3], which suggests that GAPS has a strong potential to detect
antideuterons as a dark matter signature. A GAPS prototype flight (pGAPS) was
launched successfully from the JAXA/ISAS balloon facility in Hokkaido, Japan in
summer 2012 [4, 5] and a proposed GAPS science flight is to fly from Antarctica
in the austral summer of 2017-2018.


title: Homogeneous Cotton solitons

abstract:
  Left-invariant Cotton solitons on homogeneous manifolds are determined.
Moreover, algebraic Cotton solitons are studied providing examples of
non-invariant Cotton solitons, both in the Riemannian and Lorentzian
homogeneous settings.


title: Finite rigid subgraphs of the pants graphs of punctured spheres

abstract:
  We prove a strong form of finite rigidity for pants graphs of spheres.
Specifically, for any $n\geq4$, we construct a finite subgraph $X_n$ of the
pants graph $P(S_{0,n})$ of the n-punctured sphere $S_{0,n}$ with the following
property. Any simplicial embedding of $X_n$ into any pants graph $P(S_{0,m})$
of a punctured sphere is induced by an embedding $S_{0,n} \to S_{0,m}$.


title: Neutrinos in Cosmology and Astrophysics

abstract:
  We briefly review the recent developments in neutrino physics and
astrophysics which have import for frontline research in nuclear physics. These
developments, we argue, tie nuclear physics to exciting developments in
observational cosmology and astrophysics in new ways. Moreover, the behavior of
neutrinos in dense matter is itself a fundamental problem in many-body quantum
mechanics, in some ways akin to well-known issues in nuclear matter and nuclei,
and in some ways radically different, especially because of nonlinearity and
quantum de-coherence. The self-interacting neutrino gas is the only many body
system driven by the weak interactions.


title:
F1000 recommendations as a new data source for research evaluation: A
  comparison with citations

abstract:
  F1000 is a post-publication peer review service for biological and medical
research. F1000 aims to recommend important publications in the biomedical
literature, and from this perspective F1000 could be an interesting tool for
research evaluation. By linking the complete database of F1000 recommendations
to the Web of Science bibliographic database, we are able to make a
comprehensive comparison between F1000 recommendations and citations. We find
that about 2% of the publications in the biomedical literature receive at least
one F1000 recommendation. Recommended publications on average receive 1.30
recommendations, and over 90% of the recommendations are given within half a
year after a publication has appeared. There turns out to be a clear
correlation between F1000 recommendations and citations. However, the
correlation is relatively weak, at least weaker than the correlation between
journal impact and citations. More research is needed to identify the main
reasons for differences between recommendations and citations in assessing the
impact of publications.


title: Effective Lagrangian for a light Higgs-like scalar

abstract:
  We reconsider the effective Lagrangian that describes a light Higgs-like
boson and better clarify a few issues which were not exhaustively addressed in
the previous literature. In particular we highlight the strategy to determine
whether the dynamics responsible for the electroweak symmetry breaking is
weakly or strongly interacting. We also discuss how the effective Lagrangian
can be implemented into automatic tools for the calculation of Higgs decay
rates and production cross sections.


title:
Identification of fractional order systems using modulating functions
  method

abstract:
  The modulating functions method has been used for the identification of
linear and nonlinear systems. In this paper, we generalize this method to the
on-line identification of fractional order systems based on the
Riemann-Liouville fractional derivatives. First, a new fractional integration
by parts formula involving the fractional derivative of a modulating function
is given. Then, we apply this formula to a fractional order system, for which
the fractional derivatives of the input and the output can be transferred into
the ones of the modulating functions. By choosing a set of modulating
functions, a linear system of algebraic equations is obtained. Hence, the
unknown parameters of a fractional order system can be estimated by solving a
linear system. Using this method, we do not need any initial values which are
usually unknown and not equal to zero. Also we do not need to estimate the
fractional derivatives of noisy output. Moreover, it is shown that the proposed
estimators are robust against high frequency sinusoidal noises and the ones due
to a class of stochastic processes. Finally, the efficiency and the stability
of the proposed method is confirmed by some numerical simulations.


title:
From molten salts to room temperature ionic liquids: Simulation studies
  on chloroaluminate systems

abstract:
  An interaction potential including chloride anion polarization effects,
constructed from first-principles calculations, is used to examine the
structure and transport properties of a series of chloroaluminate melts. A
particular emphasis was given to the study of the equimolar mixture of
aluminium chloride with 1-ethyl-3-methylimidazolium chloride, which forms a
room temperature ionic liquid EMI-AlCl 4. The structure yielded by the
classical simulations performed within the framework of the polarizable ion
model is compared to the results obtained from entirely electronic
structure-based simulations: An excellent agreement between the two flavors of
molecular dynamics is observed. When changing the organic cation EMI+ by an
inorganic cation with a smaller ionic radius (Li+, Na+, K+), the
chloroaluminate speciation becomes more complex, with the formation of Al2Cl 7-
in small amounts. The calculated transport properties (diffusion coefficients,
electrical conductivity and viscosity) of EMI-AlCl4 are in good agreement with
experimental data.


title: Updated Global Analysis of Higgs Couplings

abstract:
  There are many indirect and direct experimental indications that the new
particle H discovered by the ATLAS and CMS Collaborations has spin zero and
(mostly) positive parity, and that its couplings to other particles are
correlated with their masses. Beyond any reasonable doubt, it is a Higgs boson,
and here we examine the extent to which its couplings resemble those of the
single Higgs boson of the Standard Model. Our global analysis of its couplings
to fermions and massive bosons determines that they have the same relative sign
as in the Standard Model. We also show directly that these couplings are highly
consistent with a dependence on particle masses that is linear to within a few
%, and scaled by the conventional electroweak symmetry-breaking scale to within
10%. We also give constraints on loop-induced couplings, on the total Higgs
decay width, and on possible invisible decays of the Higgs boson under various
assumptions.


title: An extension of a result by Lonke to intersection bodies

abstract:
  In this paper we prove that intersection bodies cannot be direct sums using
Fourier analytic techniques. This extends a result by Lonke. We also prove a
necessary regularity condition and a convexity condition for a body of
revolution to be an intersection body of a star body.


title:
Arboricity and spanning-tree packing in random graphs with an
  application to load balancing

abstract:
  We study the arboricity A and the maximum number T of edge-disjoint spanning
trees of the Erdos-Renyi random graph G(n,p). For all p(n) in [0,1], we show
that, with high probability, T is precisely the minimum between delta and
floor(m/(n-1)), where delta is the smallest degree of the graph and m denotes
the number of edges. Moreover, we explicitly determine a sharp threshold value
for p such that: above this threshold, T equals floor(m/(n-1)) and A equals
ceiling(m/(n-1)); and below this threshold, T equals delta, and we give a
two-value concentration result for the arboricity A in that range. Finally, we
include a stronger version of these results in the context of the random graph
process where the edges are sequentially added one by one. A direct application
of our result gives a sharp threshold for the maximum load being at most k in
the two-choice load balancing problem, where k goes to infinity.


title: A Gaussian distribution for refined DT invariants and 3D partitions

abstract:
  We show that the refined Donaldson-Thomas invariants of C3, suitably
normalized, have a Gaussian distribution as limit law. Combinatorially these
numbers are given by weighted counts of 3D partitions. Our technique is to use
the Hardy-Littlewood circle method to analyze the bivariate asymptotics of a
q-deformation of MacMahon's function. The proof is based on that of E.M. Wright
who explored the single variable case.


title: Lagrangian mechanics on centered semi-direct product

abstract:
  There exists two types of semi-direct products between a Lie group $G$ and a
vector space $V$.
  The left semi-direct product, $G \ltimes V$, can be constructed when $G$ is
equipped with a left action on $V$.
  Similarly, the right semi-direct product, $G \rtimes V$, can be constructed
when $G$ is equipped with a right action on $V$.
  In this paper, we will construct a new type of semi-direct product, $G \Join
V$, which can be seen as the `sum' of a right and left semi-direct product.
  We then parallel existing semi-direct product Euler-Poincar\'{e} theory.
  We find that the group multiplication, the Lie bracket, and the diamond
operator can each be seen as a sum of the associated concepts in right and left
semi-direct product theory.
  Finally, we conclude with a toy example and the group of 2-jets of
diffeomorphisms above a fixed point.
  This final example has potential use in the creation of particle methods for
problems on diffeomorphism groups.


title:
Excitonic parameters of InxGa1-xAs-GaAs heterostructures with quantum
  wells at low temperatures

abstract:
  Characteristics of GaAs/In$_{x}$Ga$_{1-x}$As/GaAs heterostructures with a
single quantum well, which were obtained at various growth parameters, are
evaluated according to the results of measurements of low-temperature
photoluminescence spectra and their corresponding theoretical analysis.


title:
Graphene and Some of its Structural Analogues: Full-potential Density
  Functional Theory Calculations

abstract:
  Using full-potential density functional calculations we have investigated the
structural and electronic properties of graphene and some of its structural
analogues, viz., monolayer (ML) of SiC, GeC, BN, AlN, GaN, ZnO, ZnS and ZnSe.
While our calculations corroborate some of the reported results based on
different methods, our results on ZnSe, the two dimensional bulk modulus of
ML-GeC, ML-AlN, ML-GaN, ML-ZnO and ML-ZnS and the effective masses of the
charge carriers in these binary mono-layers are something new. With the current
progress in synthesis techniques, some of these new materials may be
synthesized in near future for applications in nano-devices.


title: Secondary Eclipse Photometry of the Exoplanet WASP-5b with Warm Spitzer

abstract:
  We present photometry of the extrasolar planet WASP-5b in the 3.6 and 4.5
micron bands taken with the Spitzer Space Telescope's Infrared Array Camera as
part of the extended warm mission. By examining the depth of the planet's
secondary eclipse at these two wavelengths, we can place joint constraints on
the planet's atmospheric pressure-temperature profile and chemistry. We measure
secondary eclipse depths of 0.197% +/- 0.028% and 0.227% +/- 0.025% in the 3.6
micron and 4.5 micron bands, respectively. Our observations are best matched by
models showing a hot dayside and, depending on our choice of model, a weak
thermal inversion or no inversion at all. We measure a mean offset from the
predicted center of eclipse of 0.078 +/- 0.032 hours, translating to
ecos(omega) = 0.0031 +/- 0.0013 and consistent with a circular orbit. We see no
evidence for any eclipse timing variations comparable to those reported in a
previous transit study.


title: Probing patchy reionization through tau-21cm correlation statistics

abstract:
  We consider the cross-correlation between free electrons and neutral hydrogen
during the epoch of reionization. The free electrons are traced by the optical
depth to reionization tau, while the neutral hydrogen can be observed through
21 cm photon emission. As expected, this correlation is sensitive to the
detailed physics of reionization. Foremost, if reionization occurs through the
merger of relatively large halos hosting an ionizing source, the free electrons
and neutral hydrogen are anti-correlated for most of the reionization history.
A positive contribution to the correlation can occur when the halos that can
form an ionizing source are small. A measurement of this sign change in the
cross-correlation would directly measure the bubble bias and as, such, the halo
mass. We estimate the signal-to-noise of the cross-correlation using the
estimator for inhomogeneous reionization tau_{lm} proposed by Dvorkin and Smith
(2009). We find that with upcoming radio interferometers and CMB experiments,
the cross-correlation is measurable going up to multipoles l ~ 1000. We also
derive parameter constraints and conclude that, despite the foregrounds, the
cross-correlation proofs a complementary measurement of the EoR parameters to
the 21 cm and CMB polarization auto-correlations expected to be observed in the
coming decade.


title: Conglomeration of kilometre-sized planetesimals

abstract:
  We study the efficiency of forming large bodies, starting from a sea of
equal-sized planetesimals. This is likely one of the earlier steps of planet
formation and relevant for the formation of the asteroid belt, the Kuiper belt
and extra-solar debris disks. Here we consider the case that the seed
planetesimals do not collide frequently enough for dynamical collisional to be
important (the collisionless limit), using a newly constructed conglomeration
code, and by carefully comparing numerical results with analytical scalings. In
the absence of collisional cooling, as large bodies grow by accreting small
bodies, the velocity dispersion of the small bodies ($u$) is increasingly
excited. Growth passes from the well-known run-away stage (when $u$ is higher
than the big bodies' hill velocity) to the newly discovered trans-hill stage
(when $u$ and big bodies both grow, but $u$ remains at the big bodies' hill
velocity). We find, concurring with the analytical understandings developed in
Lithwick (2014), as well as previous numerical studies, that a size spectrum
$dn/dR \propto R^{-4}$ results, and that the formation efficiency, defined as
mass fraction in bodies much larger than the initial size, is $\sim {\mathrm{ a
\,\, few}}\times R_\odot/a$, or $\sim 10^{-3}$ at the distance of the Kuiper
belt. We argue that this extreme inefficiency invalidates the conventional
conglomeration model for the formation of both our Kuiper belt and extra-solar
debris disks. New theories, possibly involving direct gravitational collapse,
or strong collisional cooling of small planetesimals, are required.


title: CIV Line-Width Anomalies: The Perils of Low S/N Spectra

abstract:
  Comparison of six high-redshift quasar spectra obtained with the Large
Binocular Telescope with previous observations from the Sloan Digital Sky
Survey shows that failure to correctly identify absorption and other problems
with accurate characterization of the CIV emission line profile in low S/N data
can severely limit the reliability of single-epoch mass estimates based on the
CIV emission line. We combine the analysis of these new high-quality data with
a reanalysis of three other samples based on high S/N spectra of the CIV
emission line region. We find that a large scatter between the Hbeta- and
CIV-based masses remains even for this high S/N sample when using the FWHM to
characterize the BLR velocity dispersion and the standard virial assumption to
calculate the mass. However, we demonstrate that using high-quality data and
the line dispersion to characterize the CIV line width leads to a high level of
consistency between CIV- and Hbeta-based masses, with <0.3 dex of observed
scatter, and an estimated ~0.2 dex intrinsic scatter, in the mass residuals.


title: After Runaway: The Trans-Hill Stage of Planetesimal Growth

abstract:
  When planetesimals begin to grow by coagulation, they enter an epoch of
runaway, during which the biggest bodies grow faster than all the others. The
questions of how runaway ends and what comes next have not been answered
satisfactorily. Here we show that runaway is followed by a `trans-hill stage'
that commences once the bodies become trans-hill, i.e. once the Hill velocity
of the bodies that dominate viscous stirring matches the random speed of the
small bodies they accrete. Subsequently, the small bodies' speed grows in
lockstep with the big bodies' sizes, such that the bodies remain in the
trans-hill state. Trans-hill growth is crucial for determining the efficiency
of growing big bodies, as well as their growth timescale and size spectrum.
  We work out the properties of trans-hill growth analytically and confirm
these numerically. Trans-hill growth has two sub-stages. In the earlier one,
collisional cooling is irrelevant, in which case the efficiency of forming big
bodies remains very low (0.1% in the Kuiper belt) and their mass spectrum is
flat. This explains results from previous coagulation simulations for both the
Kuiper belt and the asteroid belt. The second sub-stage commences when small
bodies begin to collide with one another. Collisional cooling then controls the
evolution, in which case the efficiency of forming big bodies rises, and their
size spectrum becomes more top-heavy.
  Trans-hill growth terminates in one of two ways, depending on parameters.
First, mutual accretion of big bodies can become significant and conglomeration
proceeds until half the total mass is converted into big bodies. This mode of
growth may explain the size distributions of minor bodies in the Solar System,
and is explored in forthcoming work. Second, if big bodies become separated by
their Hill radius, oligarchy commences. This mode likely precedes the formation
of fully-fledged planets.


title: Quantum Google in a Complex Network

abstract:
  We investigate the behavior of the recently proposed quantum Google
algorithm, or quantum PageRank, in large complex networks. Applying the quantum
algorithm to a part of the real World Wide Web, we find that the algorithm is
able to univocally reveal the underlying scale-free topology of the network and
to clearly identify and order the most relevant nodes (hubs) of the graph
according to their importance in the network structure. Moreover, our results
show that the quantum PageRank algorithm generically leads to changes in the
hierarchy of nodes. In addition, as compared to its classical counterpart, the
quantum algorithm is capable to clearly highlight the structure of secondary
hubs of the network, and to partially resolve the degeneracy in importance of
the low lying part of the list of rankings, which represents a typical
shortcoming of the classical PageRank algorithm. Complementary to this study,
our analysis shows that the algorithm is able to clearly distinguish scale-free
networks from other widespread and important classes of complex networks, such
as Erd\H{o}s-R\'enyi networks and hierarchical graphs. We show that the ranking
capabilities of the quantum PageRank algorithm are related to an increased
stability with respect to a variation of the damping parameter $\alpha$ that
appears in the Google algorithm, and to a more clearly pronounced power-law
behavior in the distribution of importance among the nodes, as compared to the
classical algorithm. Finally, we study to which extent the increased
sensitivity of the quantum algorithm persists under coordinated attacks of the
most important nodes in scale-free and Erd\H{o}s-R\'enyi random graphs.

categories: quant-ph cond-mat.stat-mech cs.NI physics.soc-ph


title:
Exact black hole solution for scale dependent gravitational couplings
  and the corresponding coupling flow

abstract:
  We study a black hole solution for the generalized Einstein Hilbert action
with scale dependent couplings G(r) and Lambda(r). The form of the couplings is
not imposed, but rather deduced from the existence of a non trivial symmetrical
solution. A classical-like choice of the integration constants is found.
Finally, the induced flow of the couplings is derived and compared to the flow
that is obtained in the context of the exact renormalization group approach.


title: Location of the bow shock ahead of cloud G2 at the Galactic Center

abstract:
  We perform detailed magnetohydrodynamic simulations of the gas cloud G2
interacting with the accretion flow around the Galactic Center black hole Sgr
A*. We take as our initial conditions a steady-state, converged solution of the
accretion flow obtained earlier using the general-relativistic
magnetohydrodynamic code HARM. Using the observed parameters for the cloud's
orbit, we compute the interaction of the cloud with the ambient gas and
identify the shock structure that forms ahead of the cloud. We show that for
many configurations, the cloud front crosses orbit pericenter 7 to 9 months
earlier than the center-of-mass.


title: SN2009ip: Constraints on the progenitor mass-loss rate

abstract:
  Some supernovae (SNe) show evidence for mass-loss events taking place prior
to their explosions. Measuring their pre-outburst mass-loss rates provide
essential information regarding the mechanisms that are responsible for these
events. Here we present XMM-Newton and Swift X-ray observations taken after the
latest, and presumably the final, outburst of SN 2009ip. We use these
observations as well as new near infra-red and visible light spectra, and
published radio and visible light observations to put six independent
order-of-magnitude constrains on the mass-loss rate of the SN progenitor prior
to the explosion. Our methods utilize: the X-ray luminosity, the bound-free
absorption, the H alpha luminosity, the SN rise-time, free-free absorption, and
the bolometric luminosity of the outburst detected prior to the explosion.
Assuming spherical mass-loss with a wind density profile, we estimate that the
effective mass-loss rate from the progenitor was between 10^-3 to 10^-2 solar
masses per year, over a few years prior to the explosion, with a velocity of
~1000 km/s. This mass-loss rate corresponds to a total circum stellar matter
mass of ~0.04 solar masses, within 6x10^15 cm of the SN. We note that the
mass-loss rate estimate based on the H alpha luminosity is higher by an order
of magnitude. This can be explained if the narrow line H alpha component is
generated at radii larger than the shock radius, or if the CSM has an
aspherical geometry. We discuss simple geometries which are consistent with our
results.


title: Bootstrapping from inflationary magnetogenesis to CMB initial conditions

abstract:
  The temperature and polarization anisotropies of the Cosmic Microwave
Background are analyzed under the hypothesis that the same inflationary seed
accounting for protogalactic magnetism also affects the Einstein-Boltzmann
hierarchy whose initial conditions are assigned for typical correlation scales
larger than the Hubble radius after matter-radiation equality but before
decoupling. Since the primordial gauge spectrum depends on a combination of
pivotal parameters of the concordance model, the angular power spectra of the
temperature and of the polarization are computed, for the first time, in the
presence of a putative large-scale magnetic field of inflationary origin and
without supplementary hypotheses.


title: Constraining New Physics with D meson decays

abstract:
  Latest Lattice results on $D$ form factors evaluation from first principles
show that the standard model (SM) branching ratios prediction for the leptonic
$D_s \to \ell \nu_\ell$ decays and the semileptonic SM branching ratios of the
$D^0$ and $D^+$ meson decays are in good agreement with the world average
experimental measurements. It is possible to disprove New Physics hypothesis or
find bounds over several models beyond the SM. Using the observed leptonic and
semileptonic branching ratios for the D meson decays, we performed a combined
analysis to constrain non standard interactions which mediate the $c\bar{s}\to
l\bar{\nu}$ transition. This is done either by a model independent way through
the corresponding Wilson coefficients or in a model dependent way by finding
the respective bounds over the relevant parameters for some models beyond the
standard model. In particular, we obtain bounds for the Two Higgs Doublet Model
Type-II and Type III, the Left-Right model, the Minimal Supersymmetric Standard
Model with explicit R-Parity violation and Leptoquarks. Finally, we estimate
the transverse polarization of the lepton in the $D^0$ decay and we found it
can be as high as $P_T=0.23$.


title: The teleparallel equivalent of general relativity

abstract:
  A review of the teleparallel equivalent of general relativity is presented.
It is emphasized that general relativity may be formulated in terms of the
tetrad fields and of the torsion tensor, and that this geometrical formulation
leads to alternative insights into the theory. The equivalence with the
standard formulation in terms of the metric and curvature tensors takes place
at the level of field equations. The review starts with a brief account of the
history of teleparallel theories of gravity. Then the ordinary interpretation
of the tetrad fields as reference frames adapted to arbitrary observers in
space-time is discussed, and the tensor of inertial accelerations on frames is
obtained. It is shown that the Lagrangian and Hamiltonian field equations allow
to define the energy, momentum and angular momentum of the gravitational field,
as surface integrals of the field quantities. In the phase space of the theory,
these quantities satisfy the algebra of the Poincar\'{e} group.


title: Fractal globule as an artificial molecular machine

abstract:
  The relaxation of an elastic network, constructed by a contact map of a
fractal (crumpled) polymer globule is investigated. We found that: i) the
slowest mode of the network is separated from the rest of the spectrum by a
wide gap, and ii) the network quickly relaxes to a low--dimensional
(one-dimensional, in our demonstration) manifold spanned by slowest degrees of
freedom with a large basin of attraction, and then slowly approaches the
equilibrium not escaping this manifold. By these dynamic properties, the
fractal globule elastic network is similar to real biological molecular
machines, like myosin. We have demonstrated that unfolding of a fractal globule
can be described as a cascade of equilibrium phase transitions in a
hierarchical system. Unfolding manifests itself in a sequential loss of
stability of hierarchical levels with the temperature change.


title: Kepler planets: a tale of evaporation

abstract:
  (Abridged) Inspired by the Kepler planet discoveries, we consider the thermal
contraction of planets close to their parent star, under the influence of
evaporation. The mass-loss rates are based on hydrodynamic models of
evaporation that include both X-ray and EUV irradiation. We find that only
low-mass planets with hydrogen envelopes are significantly affected by
evaporation, with evaporation being able to remove massive hydrogen envelopes
inward of 0.1 AU for Neptune-mass objects.
  We construct a theoretical population of planets with varying core masses,
envelope masses, orbital separations, and stellar spectral types, and compare
these against the sizes and densities measured for low-mass planets, both in
the Kepler mission and from radial velocity surveys. This exercise leads us to
conclude that evaporation is the driving force of evolution for close-in Kepler
planets. In fact, some 50% of the Kepler planet candidates may have been
significantly eroded. Evaporation explains two striking correlations observed
in these objects: a lack of large radius/low density planets close to the
stars, and a bimodal distribution in planet sizes with a deficit of planets
around 2R_E. Planets that have experienced high X-ray exposures are generally
smaller than this size, and those with lower X-ray exposures are typically
larger. A bimodal distribution is naturally explained by the evaporation model,
where, depending on their X-ray exposure, close-in planets can either hold on
to hydrogen envelopes 1% in mass, or be stripped entirely.
  To quantitatively reproduce the observed features, we argue that not only do
low-mass Kepler planets need to be made of rocky cores overlaid with hydrogen
envelopes, but few of them should have initial masses above 20 M_E, and the
majority of them should have core masses of a few Earth masses.


title: A silicon electromechanical photodetector

abstract:
  Opto-mechanical systems have enabled wide-band optical frequency conversion
and multi-channel all-optical radio frequency amplification. Realization of an
on-chip silicon communication platform is limited by photodetectors needed to
convert optical information to electrical signals for further signal
processing. In this paper we present a coupled silicon micro-resonator, which
converts near-IR optical intensity modulation at 174.2MHz and 1.198GHz into
motional electrical current. This device emulates a photodetector which detects
intensity modulation of continuous wave laser light in the
full-width-at-half-maximum bandwidth of the mechanical resonance. The resonant
principle of operation eliminates dark current challenges associated with
convetional photodetectors.


title:
Efficient Evolutionary Algorithm for Single-Objective Bilevel
  Optimization

abstract:
  Bilevel optimization problems are a class of challenging optimization
problems, which contain two levels of optimization tasks. In these problems,
the optimal solutions to the lower level problem become possible feasible
candidates to the upper level problem. Such a requirement makes the
optimization problem difficult to solve, and has kept the researchers busy
towards devising methodologies, which can efficiently handle the problem.
Despite the efforts, there hardly exists any effective methodology, which is
capable of handling a complex bilevel problem. In this paper, we introduce
bilevel evolutionary algorithm based on quadratic approximations (BLEAQ) of
optimal lower level variables with respect to the upper level variables. The
approach is capable of handling bilevel problems with different kinds of
complexities in relatively smaller number of function evaluations. Ideas from
classical optimization have been hybridized with evolutionary methods to
generate an efficient optimization algorithm for generic bilevel problems. The
efficacy of the algorithm has been shown on two sets of test problems. The
first set is a recently proposed SMD test set, which contains problems with
controllable complexities, and the second set contains standard test problems
collected from the literature. The proposed method has been evaluated against
two benchmarks, and the performance gain is observed to be significant.


title:
Multiple recurrence and convergence for certain averages along shifted
  primes

abstract:
  We show any subset $A\subset\mathbb{N}$ with positive upper Banach density
contains the pattern $\{m,m+[n\alpha],\dots,m+k[n\alpha]\}$, for some
$m\in\mathbb{N}$ and $n=p-1$ for some prime $p$, where
$\alpha\in\mathbb{R}\backslash\mathbb{Q}$. Making use for the Furstenberg
Correspondence Principle, we do this by proving an associated recurrence result
in ergodic theory along the shifted primes. We also prove the convergence
result for the associated averages along primes and indicate other applications
of these methods.