title:
Is a deep one-cell meridional circulation essential for the flux
  transport Solar Dynamo?

abstract:
  The solar activity cycle is successfully modeled by the flux transport
dynamo, in which the meridional circulation of the Sun plays an important role.
Most of the kinematic dynamo simulations assume a one-cell structure of the
meridional circulation within the convection zone, with the equatorward return
flow at its bottom. In view of the recent claims that the return flow occurs at
a much shallower depth, we explore whether a meridional circulation with such a
shallow return flow can still retain the attractive features of the flux
transport dynamo (such as a proper butterfly diagram, the proper phase relation
between the toroidal and poloidal fields). We consider additional cells of the
meridional circulation below the shallow return flow---both the case of
multiple cells radially stacked above one another and the case of more
complicated cell patterns. As long as there is an equatorward flow in low
latitudes at the bottom of the convection zone, we find that the solar behavior
is approximately reproduced. However, if there is either no flow or a poleward
flow at the bottom of the convection zone, then we cannot reproduce solar
behavior. On making the turbulent diffusivity low, we still find periodic
behavior, although the period of the cycle becomes unrealistically large. Also,
with a low diffusivity, we do not get the observed correlation between the
polar field at the sunspot minimum and the strength of the next cycle, which is
reproduced when diffusivity is high. On introducing radially downward pumping,
we get a more reasonable period and more solar-like behavior even with low
diffusivity.


title: Tunable nonlinear PT-symmetric defect modes with an atomic cell

abstract:
  We propose a scheme of creating a tunable highly nonlinear defect in a
one-dimensional photonic crystal. The defect consists of an atomic cell filled
in with two isotopes of three-level atoms. The probe-field refractive index of
the defect can be made parity-time (PT) symmetric, which is achieved by proper
combination of a control field and of Stark shifts induced by a
far-off-resonance field. In the PT-symmetric system families of stable
nonlinear defect modes can be formed by the probe field.


title:
Increasing stability for determining the potential in the Schr\"odinger
  equation with attenuation from the Dirichlet-to-Neumann map

abstract:
  We derive some bounds which can be viewed as an evidence of increasing
stability in the problem of recovering the potential coefficient in the
Schr\"odinger equation from the Dirichlet-to-Neumann map in the presence of
attenuation, when energy level/frequency is growing. These bounds hold under
certain a-priori regularity constraints on the unknown coefficient. Proofs use
complex and bounded complex geometrical optics solutions.


title:
Sensitivity, uncertainty analyses and algorithm selection for Sea Ice
  Thickness retrieval from Radar Altimeter

abstract:
  For accurate forecast of climate change, sea ice mass balance, ocean
circulation and sea- atmosphere interactions is required to have long term
records of Sea Ice Thickness (SIT). Different approaches have been applied to
retrieve SIT and only satellite altimetry, radar or laser, have been proven to
provide hemispheric estimates of SIT distribution over a sufficient thickness
range. To simplify the algorithm for SIT retrieval from RA, constant ice
density has been applied until now, which lead to different results for derived
SIT and SID, in dependence on input information for sea ice density and snow
depth. The purpose of this paper is to select algorithm for SID and SIT
retrieval from RA, using statistical, sensitivity analyses and independent
observations of SID from moored ULS, or on Submarine. The impact of ice density
and snow depth on accuracy of the retrieved SIT has been examined, applying
sensitivity analyses, and the propagated uncertainties have been summarised.
Accuracy of algorithms for snow depth retrieval in the Arctic have been
discussed and it is concluded that the assumption of half snow depth over First
Year Ice (FYI) will lead always to underestimation of SIT and SID derived from
RA and is not applicable for SIT retrieval from RA, using the equation for
hydrostatic equilibrium. Algorithms for freeboard depended ice densities and
SIT retrieval from RA have been developed and a FD algorithm for SIT retrieval
from RA has been selected, based on statistical, sensitivity analyses and
comparison with collocated observations of SID from moored ULS and on Submarine
. ESA (ERS1, 2, ENVISAT, CryoSat2), future ESA (Sentinel) and NASA satellite
and airborne missions, climate and numerical forecast programs will benefit the
results of this paper.


title:
Emptiness and Universality Problems in Timed Automata with Positive
  Frequency

abstract:
  The languages of infinite timed words accepted by timed automata are
traditionally defined using Buchi-like conditions. These acceptance conditions
focus on the set of locations visited infinitely often along a run, but
completely ignore quantitative timing aspects. In this paper we propose a
natural quantitative semantics for timed automata based on the so-called
frequency, which measures the proportion of time spent in the accepting
locations. We study various properties of timed languages accepted with
positive frequency, and in particular the emptiness and universality problems.


title:
Gravitational phase transitions with an exclusion constraint in position
  space

abstract:
  We discuss the statistical mechanics of a system of self-gravitating
particles with an exclusion constraint in position space in a space of
dimension $d$. The exclusion constraint puts an upper bound on the density of
the system and can stabilize it against gravitational collapse. We plot the
caloric curves giving the temperature as a function of the energy and
investigate the nature of phase transitions as a function of the size of the
system and of the dimension of space in both microcanonical and canonical
ensembles. We consider stable and metastable states and emphasize the
importance of the latter for systems with long-range interactions. For $d\le
2$, there is no phase transition. For $d>2$, phase transitions can take place
between a "gaseous" phase unaffected by the exclusion constraint and a
"condensed" phase dominated by this constraint. The condensed configurations
have a core-halo structure made of a "rocky core" surrounded by an
"atmosphere", similar to a giant gaseous planet. For large systems there exist
microcanonical and canonical first order phase transitions. For intermediate
systems, only canonical first order phase transitions are present. For small
systems there is no phase transition at all. As a result, the phase diagram
exhibits two critical points, one in each ensemble. There also exist a region
of negative specific heats and a situation of ensemble inequivalence for
sufficiently large systems. By a proper interpretation of the parameters, our
results have application for the chemotaxis of bacterial populations in biology
described by a generalized Keller-Segel model including an exclusion constraint
in position space. They also describe colloids at a fluid interface driven by
attractive capillary interactions when there is an excluded volume around the
particles. Connexions with two-dimensional turbulence are also mentioned.


title:
Twist-two operators and the BFKL regime - nonstandard solutions of the
  Baxter equation

abstract:
  The link between BFKL physics and twist-two operators involves an analytical
continuation in the spin of the operators away from the physical even integer
values. Typically this is done only after obtaining an analytical result for
integer spin through nested harmonic sums. In this paper we propose analyticity
conditions for the solution of Baxter equation which would work directly for
any value of complex spin and reproduce results from the analytical
continuation of harmonic sums. We carry out explicit contructions up to 2-loop
level. These nonstandard solutions of the Baxter equation have rather
surprising asymptotics. We hope that these analyticity conditions may be used
for incorporating them into the exact TBA/FiNLIE/QSC approaches valid at any
coupling.


title: Continuous model for pathfinding system with self-recovery property

abstract:
  This study propose a continuous pathfinding system based on coupled
oscillator systems. We consider acyclic graphs whose vertices are connected by
unidirectional edges. The proposed model autonomously finds a path connecting
two specified vertices, and the path is represented by phase-synchronized
oscillatory solutions. To develop a system capable of self-recovery, that is, a
system with the ability to find a path when one of the connections in the
existing path is suddenly removed, we implemented three-state Boolean-like
regulatory rules for interaction functions. We also demonstrate that
appropriate installation of inhibitory interaction improves the finding time.


title: The Limit Shape of a Stochastic Bulgarian Solitaire

abstract:
  We consider a stochastic version of Bulgarian solitaire: A number of cards
are distributed in piles; in every round a new pile is formed by cards from the
old piles, and each card is picked independently with a fixed probability. This
game corresponds to a multi-square birth-and-death process on Young diagrams of
integer partitions. We prove that this process converges in a strong sense to
an exponential limit shape as the number of cards tends to infinity.
Furthermore, we bound the probability of deviation from the limit shape and
relate this to the number of rounds played in the solitaire.


title: Non-singular bounce transitions in the multiverse

abstract:
  According to classical GR, negative-energy (AdS) bubbles in the multiverse
terminate in big crunch singularities. It has been conjectured, however, that
the fundamental theory may resolve these singularities and replace them by
non-singular bounces. Here we explore possible dynamics of such bounces using a
simple modification of the Friedmann equation, which ensures that the scale
factor bounces when the matter density reaches some critical value $\rho_c$.
This is combined with a simple scalar field `landscape', where the energy
barriers between different vacua are small compared to $\rho_c$. We find that
the bounce typically results in a transition to another vacuum, with a scalar
field displacement $\Delta\phi \sim 1$ in Planck units. If the new vacuum is
AdS, we have another bounce, and so on, until the field finally transits to a
positive-energy (de Sitter) vacuum. We also consider perturbations about the
homogeneous solution and discuss some of their amplification mechanisms (e.g.,
tachyonic instability and parametric resonance). For a generic potential, these
mechanisms are much less efficient than in models of slow-roll inflation. But
the amplification may still be strong enough to cause the bubble to fragment
into a mosaic of different vacua.


title: High-dimensional cluster analysis with the Masked EM Algorithm

abstract:
  Cluster analysis faces two problems in high dimensions: first, the `curse of
dimensionality' that can lead to overfitting and poor generalization
performance; and second, the sheer time taken for conventional algorithms to
process large amounts of high-dimensional data. In many applications, only a
small subset of features provide information about the cluster membership of
any one data point, however this informative feature subset may not be the same
for all data points. Here we introduce a `Masked EM' algorithm for fitting
mixture of Gaussians models in such cases. We show that the algorithm performs
close to optimally on simulated Gaussian data, and in an application of `spike
sorting' of high channel-count neuronal recordings.


title: The Production of Small Primary Craters on Mars and the Moon

abstract:
  We model the primary crater production of small (D < 100 m) primary craters
on Mars and the Moon using the observed annual flux of terrestrial fireballs.
From the size-frequency distribution (SFD) of meteor diameters, with
appropriate velocity distributions for Mars and the Moon, we are able to
reproduce martian and lunar crater-count chronometry systems (isochrons) in
both slope and magnitude. We include an atmospheric model for Mars that
accounts for the deceleration, ablation, and fragmentation of meteors. We find
that the details of the atmosphere or the fragmentation of the meteors do not
strongly influence our results. The downturn in the crater SFD from atmospheric
filtering is predicted to occur at D ~ 10-20 cm, well below the downturn
observed in the distribution of fresh craters detected by the Mars Global
Surveyor (MGS) Mars Orbiter Camera (MOC) or the Mars Reconnaissance Orbiter
(MRO) Context Camera (CTX). Crater counts conducted on the ejecta blanket of
Zunil crater on Mars and North Ray crater on the Moon yielded crater SFDs with
similar slopes and ages (~1 Ma, and ~58 Ma, respectively) to our model,
indicating that the average cratering rate has been constant on these bodies
over these time periods. Since our Monte Carlo simulations demonstrate that the
existing crater chronology systems can be applied to date young surfaces using
small craters on the Moon and Mars, we conclude that the signal from secondary
craters in the isochrons must be relatively small, as our Monte Carlo model
only generates primary craters.


title:
Overlap Dirac operator with chiral chemical potential and Chiral
  Magnetic Effect on the lattice

abstract:
  A self-consistent construction of the overlap lattice Dirac operator coupled
to chiral chemical potential is proposed. With the help of the constructed
operator we compute electric current induced by a constant magnetic field
(Chiral Magnetic Effect). We find that the result disagrees with the one
predicted by anomaly-based arguments and comment on the origin of this
discrepancy. We demonstrate that a straightforward lattice calculation with a
constant magnetic field and a uniform chiral chemical potential in fact
corresponds to an infrared singularity in the dimensionally reduced
polarization tensor and hence yields the result which is extremely sensitive to
infrared regulators such as finite volume or finite temperature.


title:
Squeezing a thermal mechanical oscillator by stabilized parametric
  effect on the optical spring

abstract:
  We report the confinement of an optomechanical micro-oscillator in a squeezed
thermal state, obtained by parametric modulation of the optical spring. We
propose and implement an experimental scheme based on parametric feedback
control of the oscillator, which stabilizes the amplified quadrature while
leaving the orthogonal one unaffected. This technique allows us to surpass the
-3dB limit in the noise reduction, associated to parametric resonance, with a
best experimental result of -7.4dB. In a moderately cooled system, our
technique can be efficiently exploited to produce strong squeezing of a
macroscopic mechanical oscillator below the zero-point motion.


title:
From Cues to Signals: Evolution of Interspecific Communication Via
  Aposematism and Mimicry in a Predator-Prey System

abstract:
  Current evolutionary theory suggests that many natural signaling systems
evolved from preexisting cues. In aposematic systems, prey warning signals
benefit both predator and prey. When the signal is highly beneficial, a third
species often evolves to mimic the unpalatable species, exploiting the
signaling system for its own protection. We investigated the evolutionary
development of predator cue utilization and prey signaling in a digital
predator-prey system in which mimicking prey could evolve to alter their
appearance to resemble poison-free or poisonous prey. In predators, we observed
rapid evolution of cue recognition (i.e. active behavioral responses) when
presented with sufficiently poisonous prey. In addition, active signaling (i.e.
mimicry) evolved in prey under all conditions that led to cue utilization. Thus
we show that despite imperfect and dishonest signaling, given a high cost of
consuming poisonous prey, complex systems of interspecific communication can
evolve via predator cue recognition and prey signal manipulation. This provides
evidence supporting hypotheses that cues may serve as stepping-stones in the
evolution of more advanced communication systems and signals incorporating
information about the environment.


title: General Purpose Textual Sentiment Analysis and Emotion Detection Tools

abstract:
  Textual sentiment analysis and emotion detection consists in retrieving the
sentiment or emotion carried by a text or document. This task can be useful in
many domains: opinion mining, prediction, feedbacks, etc. However, building a
general purpose tool for doing sentiment analysis and emotion detection raises
a number of issues, theoretical issues like the dependence to the domain or to
the language but also pratical issues like the emotion representation for
interoperability. In this paper we present our sentiment/emotion analysis
tools, the way we propose to circumvent the di culties and the applications
they are used for.


title:
Spontaneous generation of inertial waves from boundary turbulence in a
  librating sphere

abstract:
  In this work, we report the excitation of inertial waves in a librating
sphere even for libration frequencies where these waves are not directly
forced. This spontaneous generation comes from the localized turbulence induced
by the centrifugal instabilities in the Ekman boundary layer near the equator
and does not depend on the libration frequency. We characterize the key
features of these inertial waves in analogy with previous studies of the
generation of internal waves in stratified flows from localized turbulent
patterns. In particular, the temporal spectrum exhibits preferred values of
excited frequency. This first-order phenomenon is generic to any rotating flow
in the presence of localized turbulence and is fully relevant for planetary
applications.


title:
Nano-scale buckling in lamellar block polymers: a molecular dynamics
  simulation approach

abstract:
  Oriented block copolymers exhibit a buckling instability when submitted to a
tensile test perpendicular to the lamellae direction. In this paper we study
this behavior using a coarse grained molecular dynamics simulation approach.
Coarse grained models of lamellar copolymers with alternate glassy rubbery
layers are generated using the Radical Like Polymerization method, and their
mechanical response is studied. For large enough systems, uniaxial tensile
tests perpendicular to the direction of the lamellae reveal the occurrence of
the buckling instability at low strain. The results that emerge from molecular
simulation are compared to an elastic theory of the buckling instability
introduced by Read and coworkers. At high strain rates, significant differences
are observed between elastic theory and simulation results for the buckling
strain and the buckling wavelength. We explain this difference by the strain
rate dependence of the mechanical response. A simple model that takes into
account the influence of the strain rate in the mechanical response is
presented to rationalize the results at low and moderate strain rates. At very
high strain rates, cavitation takes place in the rubbery phase of the sample
and limits the validity of the approach.


title:
Energy levels of an anharmonic oscillator in both weak and strong
  coupling limit using convergency of Morse-Feshbach non-linear perturbation
  series

abstract:
  We make an extensive rigorous study on convergent behaviour of Morse-Feshbach
nonlinear perturbation series (MFNPS) to find out energy levels of the
anharmonic oscillator (AHO) in both weak and strong coupling limit. We develop
a new method of multi step optimal splitting in order to get convergency in
MFNPS for ground state of AHO and found that two step optimal splitting is
sufficient to provide convergency in MFNPS. Unlike the ground state the optimal
splitting parameters for excited states is modified according to their
dependency on state in order to achieve convergency in MFNPS.


title:
Approximating Markov chains and V-geometric ergodicity via weak
  perturbation theory

abstract:
  Let $P$ be a Markov kernel on a measurable space $\X$ and let
$V:\X\r[1,+\infty)$. This paper provides explicit connections between the
$V$-geometric ergodicity of $P$ and that of finite-rank nonnegative sub-Markov
kernels $\Pc_k$ approximating $P$. A special attention is paid to obtain an
efficient way to specify the convergence rate for $P$ from that of $\Pc_k$ and
conversely. Furthermore, explicit bounds are obtained for the total variation
distance between the $P$-invariant probability measure and the
$\Pc_k$-invariant positive measure. The proofs are based on the Keller-Liverani
perturbation theorem which requires an accurate control of the essential
spectral radius of $P$ on usual weighted supremum spaces. Such computable
bounds are derived in terms of standard drift conditions. Our spectral
procedure to estimate both the convergence rate and the invariant probability
measure of $P$ is applied to truncation of discrete Markov kernels on $\X:=\N$.


title: The noisy Hegselmann-Krause model for opinion dynamics

abstract:
  In the model for continuous opinion dynamics introduced by Hegselmann and
Krause, each individual moves to the average opinion of all individuals within
an area of confidence. In this work we study the effects of noise in this
system. With certain probability, individuals are given the opportunity to
change spontaneously their opinion to another one selected randomly inside the
opinion space with different rules. If the random jump does not occur,
individuals interact through the Hegselmann-Krause's rule. We analyze two
cases, one where individuals can carry out opinion random jumps inside the
whole opinion space, and other where they are allowed to perform jumps just
inside a small interval centered around the current opinion. We found that
these opinion random jumps change the model behavior inducing interesting
phenomena. Using pattern formation techniques, we obtain approximate analytical
results for critical conditions of opinion cluster formation. Finally, we
compare the results of this work with the noisy version of the Deffuant et al.
model for continuous-opinion dynamics.


title:
How to identify the structure of near-threshold states from the line
  shape

abstract:
  We revisit the compositeness theorem proposed by Weinberg in an effective
field theory (EFT) and explore criteria which are sensitive to the structure of
$S$-wave threshold states. On a general basis, we show that the wave function
renormalization constant $Z$, which is the probability of finding an elementary
component in the wave function of a threshold state, can be explicitly
introduced in the description of the threshold state. As an application of this
EFT method, we describe the near-threshold line shape of the $D^{\ast 0}\bar
D^0$ invariant mass spectrum in $B\rightarrow D^{\ast 0}\bar D^0 K$ and
determine a nonvanishing value of $Z$. It suggests that the $X(3872)$ as a
candidate of the $D^{\ast 0}\bar D^0$ molecule may still contain a small
$c\bar{c}$ core. This elementary component, on the one hand, explains its
production in the $B$ meson decay via a short-distance mechanism, and on the
other hand, is correlated with the $D^{\ast 0}\bar D^0$ threshold enhancement
observed in the $D^{\ast 0}\bar D^0$ invariant mass distributions. Meanwhile,
we also show that if $Z$ is non-zero, the near-threshold enhancement of the
$D^{\ast 0}\bar D^0$ mass spectrum in the $B$ decay will be driven by the
short-distance production mechanism. This conclusion is still true even if the
long-distance production is enhanced by some unexpected mechanism.


title: Weber's optimal stopping problem and generalizations

abstract:
  One way to interpret the classical secretary problem (CSP) is to consider it
as a special case of the following problem. We observe $n$ independent
indicator variables $I_1,I_2,\dotsc,I_n$ sequentially and we try to stop on the
last variable being equal to 1. If $I_k=1$ it means that the $k$-th observed
secretary has smaller rank than all previous ones (and therefore is a better
secretary). In the CSP $p_k=E(I_k)=1/k$ and the last $k$ with $I_k=1$ stands
for the best candidate. The more general problem of stopping on a last "1" was
studied by Bruss(2000). In what we will call Weber's problem the variables
$I_k$ can take more than two values and we try to stop on the last occurence of
\textit{one} of these values. Notice that we do not know in advance the value
taken by the variable on which we stop.
  We can solve this problem in some cases and provide algorithms to compute the
optimal stopping rule. These cases carry enough generality to be applicable in
concrete situations.


title: Pairing Symmetry, Spin-Gap and more in HTSC Cuprates

abstract:
  This work is based on the double correlated linear aggregations of holes in
checkerboard geometry. It is proved that the pairing function symmetry is -
d(x*x-y*y), as been observed experimentally. It is also shown that there is a
"superconductive spin gap" for the observation of the magnetic incommensurate
modulation peaks, in agreement with experiment. In addition, the unperturbed
Hamiltonian is reanalyzed and modified.


title:
Weighted reciprocal of temperature, weighted thermal flux, and their
  applications in finite-time thermodynamics

abstract:
  The concepts of weighted reciprocal of temperature and weighted thermal flux
are proposed for a heat engine operating between two heat baths and outputting
mechanical work. With the aid of these two concepts, the generalized
thermodynamic fluxes and forces can be expressed in a consistent way within the
framework of irreversible thermodynamics. Then the efficiency at maximum power
output for a heat engine, one of key topics in finite-time thermodynamics, is
investigated on the basis of a generic model under the tight-coupling
condition. The corresponding results have the same forms as those of
low-dissipation heat engines [M. Esposito, R. Kawai, K. Lindenberg, and C. Van
den Broeck, {Phys. Rev. Lett.} \textbf{105}, 150603 (2010)]. The mappings from
two kinds of typical heat engines, such as the low-dissipation heat engine and
the Feynman ratchet, into the present generic model are constructed. The
universal efficiency at maximum power output up to the quadratic order is found
to be valid for a heat engine coupled symmetrically and tightly with two baths.
The concepts of weighted reciprocal of temperature and weighted thermal flux
are also transplanted to the optimization of refrigerators.


title: Edge states in bilayer graphene in a magnetic field

abstract:
  Edge states in biased bilayer graphene in a magnetic field are studied within
the four-band continuum model. The analysis is done for the semi-infinite
graphene plane and for the graphene ribbon of a finite width, in the cases of
zigzag and armchair edges. Exact dispersion equations for the edge states and
analytic expressions for their wave functions are written in terms of the
parabolic cylinder functions. The spectrum of edge states for each type of the
boundary conditions is found by numerically solving the corresponding
dispersion equations. The low-energy modes localized at zigzag edges are
explored in detail.


title: Confined colloidal crystals in and out of equilibrium

abstract:
  Recent studies on confined crystals of charged colloidal particles are
reviewed, both in equilibrium and out of equilibrium. We focus in particular on
direct comparisons of experiments (light scattering and microscopy) with
lattice sum calculations and computer simulations. In equilibrium we address
buckling and crystalline multilayering of charged systems in hard and soft slit
confinement. We discuss also recent crystalline structures obtained for charged
mixtures. Moreover, we put forward possibilities to apply external
perturbations, in order to drive the system out of equilibrium. These include
electrolyte gradients as well as the application of shear and electric fields.


title:
Time discretization of FBSDE with polynomial growth drivers and
  reaction-diffusion PDEs

abstract:
  In this paper, we undertake the error analysis of the time discretization of
systems of Forward-Backward Stochastic Differential Equations (FBSDEs) with
drivers having polynomial growth and that are also monotone in the state
variable. We show with a counter-example that the natural explicit Euler scheme
may diverge, unlike in the canonical Lipschitz driver case. This is due to the
lack of a certain stability property of the Euler scheme which is essential to
obtain convergence. However, a thorough analysis of the family of
$\theta$-schemes reveals that this required stability property can be recovered
if the scheme is sufficiently implicit. As a by-product of our analysis, we
shed some light on higher order approximation schemes for FBSDEs under
non-Lipschitz condition. We then return to fully explicit schemes and show that
an appropriately tamed version of the explicit Euler scheme enjoys the required
stability property and as a consequence converges. In order to establish
convergence of the several discretizations, we extend the canonical path- and
first-order variational regularity results to FBSDEs with polynomial growth
drivers which are also monotone. These results are of independent interest for
the theory of FBSDEs.


title: The microfluidic Kelvin water dropper

abstract:
  The so-called "Kelvin water dropper" is a simple experiment demonstrating the
spontaneous appearance of induced free charge in droplets emitted through a
tube. As Lord Kelvin explained, water droplets spontaneously acquire a net
charge during detachment from a faucet due to the presence of electrical fields
in their surrounding created by any metallic object. In his experiment, two
streams of droplets are allowed to drip from separated nozzles into separated
buckets, which are at the same time interconnected through the dripping
needles. In this paper we build a microfluidic water dropper and demonstrate
that the droplets get charged and break-up due to electrohydrodynamic
instabilities. A comparison with recent simulations shows the dependence of the
acquired charge in the droplets on different parameters of the system. The
phenomenon opens a door to cheap and accessible transformation of pneumatic
pressure into electrical energy and to an enhanced control in microfluidic and
biophysical manipulation of capsules, cells and droplets via self-induced
charging of the elements.


title:
Rapid creation of distant entanglement by multiphoton resonant
  fluorescence

abstract:
  We study a simple, effective and robust method for entangling two separate
stationary quantum dot spin qubits with high fidelity using multiphoton
Gaussian state. The fluorescence signals from the two dots interfere at a beam
splitter. The bosonic nature of photons leads, in analogy with the
Hong-Ou-Mandel effect, to selective pairing of photon holes (photon absences in
the fluorescent signals). As a result, two odd photon number detections at the
outgoing beams herald trion entanglement creation, and subsequent reduction of
the trions to the spin ground states leads to spin-spin entanglement. The
robustness of the Gaussian states is evidenced by the ability to compensate for
photon absorption and noise by a moderate increase in the number of photons at
the input. We calculate the entanglement generation rate in the ideal, nonideal
and near-ideal detector regimes and find substantial improvement over
single-photon schemes in all three regimes. Fast and efficient spin-spin
entanglement creation can form the basis for a scalable quantum dot quantum
computing network. Our predictions can be tested using current experimental
capabilities.


title: Mass estimates for visual binaries with incomplete orbits

abstract:
  The problem of estimating the total mass of a visual binary when its orbit is
incomplete is treated with Bayesian methods. The posterior mean of a mass
estimator is approximated by a triple integral over orbital period, time of
periastron and orbital eccentricity. This reduction to 3-D from the 7-D space
defined by the conventional Campbell parameters is achieved by adopting the
Thiele-Innes elements and exploiting the linearity with respect to the four
Thiele-Innes constants. The formalism is tested on synthetic observational data
covering a variable fraction of a model binary's orbit. The posterior mean of
the mass estimator is numerically found to be unbiased when the data cover >
40% of the orbit.


title:
ACTORS: A Goal-driven Approach for Capturing and Managing Consent in
  e-Health Systems

abstract:
  The notion of patient's consent plays a major role in granting access to
medical data. In typical healthcare systems, consent is captured by a form that
the patient has to fill in and sign. In e-Health systems, the paper-form
consent is being replaced by the integration of the notion of consent in the
mechanisms that regulate the access to the medical data. This helps in
empowering the patient with the capability of granting and revoking consent in
a more effective manner. However, the process of granting and revoking consent
greatly varies according to the situation in which the patient is. Our main
argument is that such a level of detail is very difficult and error-prone to
capture as a set of authorisation policies. In this paper, we present ACTORS, a
goal-driven approach to manage consent. The main idea behind ACTORS is to
leverage the goal-driven approach of Teleo-Reactive (TR) programming for
managing consent that takes into account changes regarding the domains and
contexts in which the patient is providing her consent.


title:
Analytical Framework of LDGM-based Iterative Quantization with
  Decimation

abstract:
  While iterative quantizers based on low-density generator-matrix (LDGM) codes
have been shown to be able to achieve near-ideal distortion performance with
comparatively moderate block length and computational complexity requirements,
their analysis remains difficult due to the presence of decimation steps. In
this paper, considering the use of LDGM-based quantizers in a class of
symmetric source coding problems, with the alphabet being either binary or
non-binary, it is proved rigorously that, as long as the degree distribution
satisfies certain conditions that can be evaluated with density evolution (DE),
the belief propagation (BP) marginals used in the decimation step have
vanishing mean-square error compared to the exact marginals when the block
length and iteration count goes to infinity, which potentially allows
near-ideal distortion performances to be achieved. This provides a sound
theoretical basis for the degree distribution optimization methods previously
proposed in the literature and already found to be effective in practice.


title:
Global hydromagnetic simulations of a planet embedded in a dead zone:
  gap opening, gas accretion and formation of a protoplanetary jet

abstract:
  We present global hydrodynamic and magnetohydrodynamic (MHD) simulations with
mesh refinement of accreting planets embedded in protoplanetary disks (PPDs).
The magnetized disk includes Ohmic resistivity that depends on the overlying
mass column, leading to turbulent surface layers and a dead zone near the
midplane. The main results are: (i) The accretion flow in the Hill sphere is
intrinsically 3D for hydrodynamic and MHD models. Net inflow toward the planet
is dominated by high latitude flows. A circumplanetary disk (CPD) forms. Its
midplane flows outward in a pattern whose details differ between models. (ii)
Gap opening magnetically couples and ignites the dead zone near the planet,
leading to stochastic accretion, a quasi-turbulent flow in the Hill sphere and
a CPD whose structure displays high levels of variability. (iii) Advection of
magnetized gas onto the rotating CPD generates helical fields that launch
magnetocentrifugally driven outflows. During one specific epoch a highly
collimated, one-sided jet is observed. (iv) The CPD's surface density
$\sim30{\rm\,g\,cm^{-2}}$, small enough for significant ionization and
turbulence to develop. (v) The accretion rate onto the planet in the MHD
simulation reaches a steady value $8 \times 10^{-3} {\rm M_\oplus yr^{-1}}$,
and is similar in the viscous hydrodynamic runs. Our results suggest that gas
accretion onto a forming giant planet within a magnetized PPD with dead zone
allows rapid growth from Saturnian to Jovian masses. As well as being relevant
for giant planet formation, these results have important implications for the
formation of regular satellites around gas giant planets.


title:
Random transitions described by the stochastic Smoluchowski-Poisson
  system and by the stochastic Keller-Segel model

abstract:
  We study random transitions between two metastable states that appear below a
critical temperature in a one dimensional self-gravitating Brownian gas with a
modified Poisson equation experiencing a second order phase transition from a
homogeneous phase to an inhomogeneous phase. We numerically solve the $N$-body
Langevin equations and the stochastic Smoluchowski-Poisson system which takes
fluctuations (finite $N$ effects) into account. The system switches back and
forth between the two metastable states (bistability) and the particles
accumulate successively at the center or at the boundary of the domain. We show
that these random transitions exhibit the phenomenology of the ordinary Kramers
problem for a Brownian particle in a double-well potential. The distribution of
the residence time is Poissonian and the average lifetime of a metastable state
is given by the Arrhenius law, i.e. it is proportional to the exponential of
the barrier of free energy $\Delta F$ divided by $k_B T$. Since the free energy
is proportional to the number of particles $N$ for a system with long-range
interactions, the lifetime of metastable states scales as $e^N$ and is
considerable for $N\gg 1$. As a result, in many applications, metastable states
of systems with long-range interactions can be considered as stable states.
However, for moderate values of $N$, or close to a critical point $T_c$, the
lifetime of the metastable states is reduced since the barrier of free energy
decreases. In that case, the fluctuations become important and the mean field
approximation is no more valid. This is the situation considered in this paper.
By an appropriate change of notations, our results also apply to bacterial
populations experiencing chemotaxis in biology. Their dynamics can be described
by a stochastic Keller-Segel model that takes fluctuations into account and
goes beyond the usual mean field approximation.


title: Numerical evaluation of spherical GJMS determinants

abstract:
  A numerical expression in the form of an integral is given for the
determinant of the scalar GJMS operator on an odd--dimensional sphere.
Manipulation yields a curious sum formula for the logdet in terms of the
logdets of the ordinary conformal Laplacian for other dimensions. A few graphs
are drawn.


title:
The $\Delta_2$-condition and $\varphi$-families of probability
  distributions

abstract:
  In this paper, we provide some results related to the $\Delta_2$-condition of
Musielak-Orlicz functions and $\varphi$-families of probability distributions,
which are modeled on Musielak-Orlicz spaces. We show that if two
$\varphi$-families are modeled on Musielak-Orlicz spaces generated by
Musielak-Orlicz functions satisfying the $\Delta_{2}$-condition, then these
$\varphi$-families are equal as sets. We also investigate the behavior of the
normalizing function near the boundary of the set on which a $\varphi$-family
is defined.


title: Twisted conjugacy in Richard Thompson's group T

abstract:
  Let $f$ be an automorphism of a group $G$. Two elements $x, y$ in $G$ are
said to be in the same $f$-twisted conjugacy class if there exists an element
$z$ in $G$ such that $y=z x f(z^{-1})$. This is an equivalence relation known
as $f$-twisted conjugacy. If the number $R(f)$ of $f$-twisted conjugacy classes
is infinite for every automorphism $f$ of $G$ one says that $G$ has the
$R_\infty$-property. We show that the Richard Thompson group $T$ has the
$R_\infty$-property.


title: Exact Evolution of Discrete Relativistic Cosmological Models

abstract:
  We study the effects of inhomogeneities on the evolution of the Universe, by
considering a range of cosmological models with discretized matter content.
This is done using exact and fully relativistic methods that exploit the
symmetries in and about submanifolds of spacetimes that themselves possess no
continuous global symmetries. These methods allow us to follow the evolution of
our models throughout their entire history, far beyond what has previously been
possible. We find that while some space-like curves collapse to anisotropic
singularities in finite time, others remain non-singular forever. The resulting
picture is of a cosmological spacetime in which some behaviour remains close to
Friedmann-like, while other behaviours deviate radically. In particular, we
find that large-scale acceleration is possible without any violation of the
energy conditions.


title:
Rigorous high-precision computation of the Hurwitz zeta function and its
  derivatives

abstract:
  We study the use of the Euler-Maclaurin formula to numerically evaluate the
Hurwitz zeta function $\zeta(s,a)$ for $s, a \in \mathbb{C}$, along with an
arbitrary number of derivatives with respect to $s$, to arbitrary precision
with rigorous error bounds. Techniques that lead to a fast implementation are
discussed. We present new record computations of Stieltjes constants, Keiper-Li
coefficients and the first nontrivial zero of the Riemann zeta function,
obtained using an open source implementation of the algorithms described in
this paper.


title:
Heat transport in magnetic fields by quantum spin liquid in the organic
  insulators EtMe3Sb[Pd(dmit)2]2 and \kappa-(BEDT-TTF)2Cu2(CN)3

abstract:
  Measurements of the low-temperature thermal conductivity collected on
insulators with geometrical frustration produce important experimental facts
shedding light on the nature of quantum spin liquid composed of spinons. We
employ a model of strongly correlated quantum spin liquid located near the
fermion condensation phase transition to analyze the exciting measurements of
the low-temperature thermal conductivity in magnetic fields collected on the
organic insulators EtMe3Sb[Pd(dmit)_2]2 and \kappa-(BEDT-TTF)2Cu2(CN)3. Our
analysis of the conductivity allows us to reveal a strong dependence of the
effective mass of spinons on magnetic fields, to detect a scaling behavior of
the conductivity, and to relate it to both the spin-lattice relaxation rate and
the magnetoresistivity. Our calculations and observations are in a good
agreement with experimental data.


title:
Mass formulas for local Galois representations and quotient
  singularities I: a comparison of counting functions

abstract:
  We study a relation between the Artin conductor and the weight coming from
the motivic integration over wild Deligne-Mumford stacks. As an application, we
prove some version of the McKay correspondence, which relates Bhargava's mass
formula for extensions of a local field and the Hilbert scheme of points.


title:
Stabilized fiber-optic Mach-Zehnder interferometer for carrier-frequency
  rejection

abstract:
  We have demonstrated stabilization of a fiber-optic Mach-Zehnder
interferometer, with a centimeter-scale path difference, to the transmission
minimum for the carrier wave of a frequency-modulated laser beam. A
time-averaged extinction of 32 dB, limited by the bandwidth of the feedback,
was maintained over several hours. The interferometer was used to remove the
carrier wave from a 780 nm laser beam that had been phase modulated at 2.7 GHz.


title:
Hidden $T$-Linear Scattering Rate in Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$
  Revealed by Optical Spectroscopy

abstract:
  The optical properties of Ba$_{0.6}$K$_{0.4}$Fe$_{2}$As$_{2}$ have been
determined in the normal state for a number of temperatures over a wide
frequency range. Two Drude terms, representing two groups of carriers with
different scattering rates ($1/\tau$), well describe the real part of the
optical conductivity, $\sigma_{1}(\omega)$. A "broad" Drude component results
in an incoherent background with a $T$-independent $1/\tau_b$, while a "narrow"
Drude component reveals a $T$-linear $1/\tau_n$ resulting in a resistivity
$\rho_n \equiv 1/\sigma_{1n}(\omega\rightarrow 0)$ also linear in temperature.
An arctan($T$) low-frequency spectral weight is also a strong evidence for a
$T$-linear 1/$\tau$. Comparison to other materials with similar behavior
suggests that the $T$-linear $1/\tau_n$ and $\rho_n$ in
Ba$_{0.6}$K$_{0.4}$Fe$_{2}$As$_{2}$ originate from scattering from spin
fluctuations and hence that an antiferromagnetic quantum critical point is
likely to exist in the superconducting dome.


title: Nonlinearly Realized Gauge Theories for LHC Physics

abstract:
  We consider a minimal nonlinearly realized electroweak theory where mass
generation happens \`a la Stueckelberg. Deformation of the nonlinearly realized
gauge symmetry is controlled by functional methods. The Weak Power Counting
allows to select uniquely the Hopf algebra of the theory and gives definite
predictions on the Beyond-the-Standard Model (BSM) sector of the theory: the
latter includes one CP-odd and two charged physical scalars (in addition to the
Higgs-like CP-even resonance). The model interpolates between a purely
Stueckelberg and a Higgs scenario. It can be used in order to check whether the
presence of a Stueckelberg mass component can already be excluded on the basis
of the existing LHC7-8 data.


title:
Disproving the conjecture on structural physical approximation to
  optimal decomposable entanglement witnesses

abstract:
  We disprove the conjecture that structural physical approximations to optimal
entanglement witnesses are separable states. The conjecture holds true for
extremal decomposable entanglement witnesses.


title: Causal Domain Restriction for Eikonal Equations

abstract:
  Many applications require efficient methods for solving continuous shortest
path problems. Such paths can be viewed as characteristics of static
Hamilton-Jacobi equations. Several fast numerical algorithms have been
developed to solve such equations on the whole domain. In this paper we
consider a somewhat different problem, where the solution is needed at one
specific point, so we restrict the computations to a neighborhood of the
characteristic. We explain how heuristic under/over-estimate functions can be
used to obtain a causal domain restriction, significantly decreasing the
computational work without sacrificing convergence under mesh refinement. The
discussed techniques are inspired by an alternative version of the classical A*
algorithm on graphs. We illustrate the advantages of our approach on continuous
isotropic examples in 2D and 3D. We compare its efficiency and accuracy to
previous domain restriction techniques. We also analyze the behavior of errors
under the grid refinement and show how Lagrangian (Pontryagin's Maximum
Principle-based) computations can be used to enhance our method.


title: Finitely connected domains, Rational maps and Ahlfors functions

abstract:
  Using Ahlfors functions, Grunsky maps and the Bell representation theorem, we
show that a certain subset of the rational maps of degree $n$ forms a trivial
bundle over the moduli space of non-degenerate $n$-connected domains with one
marked tangent vector with fiber the $n$-fold symmetric product of the circle.
A consequence is that the set of rational Ahlfors functions of degree $n$ forms
a closed embedded submanifold inside the space of rational maps of degree $n$.
As an application, we show the existence of rational Ahlfors functions with
non-positive residues, resolving a question left open in a previous paper by
the authors.


title: Reduced Wu and Generalized Simon Invariants for Spatial Graphs

abstract:
  We introduce invariants of spatial graphs related to the Wu invariant and the
Simon invariant, and apply them to prove that certain graphs are intrinsically
chiral, and to obtain lower bounds for the minimal crossing number of embedded
graphs.


title:
Charge avalanches and depinning in the Coulomb glass: The role of
  long-range interactions

abstract:
  We explore the stability of far-from-equilibrium metastable states of a
three-dimensional Coulomb glass at zero temperature by studying charge
avalanches triggered by a slowly varying external electric field. Surprisingly,
we identify a sharply defined dynamical ("depinning") phase transition from
stationary to nonstationary charge displacement at a critical value of the
external electric field. Using particle-conserving dynamics, scale-free
system-spanning avalanches are observed only at the critical field. We show
that the qualitative features of this depinning transition are completely
different for an equivalent short-range model, highlighting the key importance
of long-range interactions for nonequilibrium dynamics of Coulomb glasses.


title: On the Jones polynomial of 2n-plat presentations of knots

abstract:
  In this paper, a method is given to calculate the Jones polynomial of the
6-plat presentations of knots by using a representation of the braid group
$\mathbb{B}_6$ into a group of $5\times 5$ matrices. We also can calculate the
Jones polynomial of the $2n$-plat presentations of knots by generalizing the
method for the 6-plat presentations of knots.


title: Kinematics of Top Quark Final States: A Snowmass White Paper

abstract:
  This is the summary report of the Top Quark Kinematics working group prepared
for Snowmass 2013. We survey the current state of theoretical predictions for
top pair differential distributions, in both boosted and un-boosted regimes,
and present an overview of uncertainties and prospects for top spin
correlations. We study the prospects for measuring the inclusive SM top pair
production asymmetry AFC at LHC 14 as a function of systematic error, and show
that some improvement over current systematic uncertainties, as customarily
handled, is required for observing a SM-size asymmetry. Cuts on top pair
invariant mass and rapidity do not substantially alter this conclusion. We
summarize the conclusions of contributed studies on alternate LHC measurements
of the ttbar production asymmetry, in ttbar+jet final states and in forward top
production at LHCb, both of which show good prospects for observing SM-size
asymmetries in 50 fb-1 of data at LHC14.


title: Relative amenability

abstract:
  We introduce a relative fixed point property for subgroups of a locally
compact group, which we call relative amenability. It is a priori weaker than
amenability. We establish equivalent conditions, related among others to a
problem studied by Reiter in 1968. We record a solution to Reiter's problem.
  We study the class X of groups in which relative amenability is equivalent to
amenability for all closed subgroups; we prove that X contains all familiar
groups. Actually, no group is known to lie outside X.
  Since relative amenability is closed under Chabauty limits, it follows that
any Chabauty limit of amenable subgroups remains amenable if the ambient group
belongs to the vast class X.


title: Bilaplacians problems with a sign-changing coefficient

abstract:
  We investigate the properties of the operator
\Delta(\sigma\Delta.):H^2_0(\Omega)-> H^{-2}(\Omega), where \sigma is a given
parameter whose sign can change on the bounded domain \Omega. Here,
H^2_0(\Omega) denotes the subspace of H^2(\Omega) made of the functions w such
that w=\nu.\nabla w=0 on the boundary. The study of this problem arises when
one is interested in some configurations of the Interior Transmission
Eigenvalue Problem. We prove that \Delta(\sigma\Delta.):H^2_0(\Omega)->
H^{-2}(\Omega) is a Fredholm operator of index zero as soon as \sigma\in
L^{\infty}(\Omega), with \sigma^{-1}\in L^{\infty}(\Omega), is such that \sigma
remains uniformly positive (or uniformly negative) in a neighbourhood of the
boundary. We also study configurations where \sigma changes sign on the
boundary and we prove that Fredholm property can be lost for such situations.
In the process, we examine in details the features of a simpler problem where
the boundary condition \nu.\nabla v=0 is replaced by \sigma\Delta v=0.


title: Nonlinear pressure dependence of T_N in almost multiferroic EuTiO_3

abstract:
  The antiferromagnetic (AFM) phase transition temperature T_N of EuTiO_3 has
been studied as a function of pressure p. The data reveal a nonlinear
dependence of T_N on p with T_N increasing with increasing pressure. The
exchange interactions exhibit an analogous dependence on p as T_N (if the
absolute value of the nearest neighbor interaction is considered) and there is
evidence that the AFM transition is robust with increasing pressure. The
corresponding Weiss temperature {\Theta}_W remains anomalous since it always
exhibits positive values. The data are analyzed within the Bloch power law
model and provide excellent agreement with experiment.


title:
Third Order Integrable Equation Possessing Symplectic Operator Of Degree
  9

abstract:
  We perform a classification of third order integrable systems of evolution
equations with respect to higher symmetries. Applying it, we consider
polynomial systems that are 0-homogeneous under a suitable weighting of
variables with main matrix $***$ having a seventh-order symmetry. A new
integrable equation is discovered. For this new supersymmetric equation the Lax
representation and bi-Hamiltonian structures are given.


title:
Occupation Probabilities and Fluctuations in the Asymmetric Simple
  Inclusion Process

abstract:
  The Asymmetric Simple Inclusion Process (ASIP), a lattice-gas model of
unidirectional transport and aggregation, was recently proposed as an
`inclusion' counterpart of the Asymmetric Simple Exclusion Process (ASEP). In
this paper we present an exact closed-form expression for the probability that
a given number of particles occupies a given set of consecutive lattice sites.
Our results are expressed in terms of the entries of Catalan's trapezoids ---
number arrays which generalize Catalan's numbers and Catalan's triangle. We
further prove that the ASIP is asymptotically governed by: (i) an inverse
square root law of occupation; (ii) a square root law of fluctuation; and (iii)
a Rayleigh law for the distribution of inter-exit times. The universality of
these results is discussed.


title: Sparse and Functional Principal Components Analysis

abstract:
  Regularized variants of Principal Components Analysis, especially Sparse PCA
and Functional PCA, are among the most useful tools for the analysis of complex
high-dimensional data. Many examples of massive data, have both sparse and
functional (smooth) aspects and may benefit from a regularization scheme that
can capture both forms of structure. For example, in neuro-imaging data, the
brain's response to a stimulus may be restricted to a discrete region of
activation (spatial sparsity), while exhibiting a smooth response within that
region. We propose a unified approach to regularized PCA which can induce both
sparsity and smoothness in both the row and column principal components. Our
framework generalizes much of the previous literature, with sparse, functional,
two-way sparse, and two-way functional PCA all being special cases of our
approach. Our method permits flexible combinations of sparsity and smoothness
that lead to improvements in feature selection and signal recovery, as well as
more interpretable PCA factors. We demonstrate the efficacy of our method on
simulated data and a neuroimaging example on EEG data.


title: Skewness, kurtosis and Newton's inequality

abstract:
  We show that an inequality related to Newton's inequality provides one more
relation between skewness and kurtosis. This also gives simple and alternative
proofs of the bounds for skewness and kurtosis.


title:
The linearity problem for the unitriangular automorphism groups of free
  groups

abstract:
  We prove that the unitriangular automorphism group of a free group of rank
$n$ has a faithful representation by matrices over a field, or in other words,
it is a linear group, if and only if $n \leq 3.$ Thus, we have completed a
description of relatively free groups with linear the unitriangular
automorphism groups. This description was initiated by Erofeev and the author
in \cite{Erofeev}, where proper varieties of groups have been considered.


title:
Graphs of Edge-Intersecting Non-Splitting Paths in a Tree: Towards Hole
  Representations-Part I

abstract:
  Given a tree and a set ${\cal P}$ of non-trivial simple paths on it,
$VPT({\cal P})$ is the VPT graph (i.e. the vertex intersection graph) of the
paths ${\cal P}$ of the tree $T$, and $EPT({\cal P})$ is the EPT graph (i.e.
the edge intersection graph) of ${\cal P}$. These graphs have been extensively
studied in the literature. Given two (edge) intersecting paths in a graph,
their \emph{split vertices} is the set of vertices having degree at least $3$
in their union. A pair of (edge) intersecting paths is termed
\emph{non-splitting} if they do not have split vertices (namely if their union
is a path).
  In this work, motivated by an application in all-optical networks, we define
the graph $ENPT({\cal P})$ of edge-intersecting non-splitting paths of a tree,
termed the ENPT graph, as the (edge) graph having a vertex for each path in
${\cal P}$, and an edge between every pair of paths that are both
edge-intersecting and non-splitting. A graph $G$ is an ENPT graph if there is a
tree $T$ and a set of paths ${\cal P}$ of $T$ such that $G=ENPT({\cal P})$, and
we say that $<T,{\cal P}>$ is a \emph{representation} of $G$. We first show
that cycles, trees and complete graphs are ENPT graphs.
  Our work follows the lines of Golumbic and Jamison's research in which they
defined the EPT graph class, and characterized the representations of chordless
cycles (holes). It turns out that ENPT holes have a more complex structure than
EPT holes. In our analysis, we assume that the EPT graph corresponding to a
representation of an ENPT hole is given. We also introduce three assumptions
$(P1)$, $(P2)$, $(P3)$ defined on EPT, ENPT pairs of graphs. In this Part I,
using the results of Golumbic and Jamison as building blocks, we characterize
(a) EPT, ENPT pairs that satisfy $(P1)$, $(P2)$, $(P3)$, and (b) the unique
minimal representation of such pairs.


title:
Mapping a star with transits: orbit precession effects in the Kepler-13
  system

abstract:
  Kepler-13b (KOI-13.01) is a most intriguing exoplanet system due to the rapid
precession rate, exhibiting several exotic phenomena. We analyzed $Kepler$
Short Cadence data up to Quarter 14, with a total time-span of 928 days, to
reveal changes in transit duration, depth, asymmetry, and identify the possible
signals of stellar rotation and low-level activity. We investigated long-term
variations of transit light curves, testing for duration, peak depth and
asymmetry. We also performed cluster analysis on $Kepler$ quarters. We computed
the autocorrelation function of the out-of-transit light variations. Transit
duration, peak depth, and asymmetry evolve slowly, due to the slowly drifting
transit path through the stellar disk. The detected transit shapes will map the
stellar surface on the time scale of decades. We found a very significant
clustering pattern with 3-orbit period. Its source is very probably the
rotating stellar surface, in the 5:3 spin-orbit resonance reported in a
previous study. The autocorrelation function of the out-of-transit light
variations, filtered to 25.4 hours and harmonics, shows slow variations and a
peak around 300--360 day period, which could be related to the activity cycle
of the host star.


title: Mining for Spatially-Near Communities in Geo-Located Social Networks

abstract:
  Current approaches to community detection in social networks often ignore the
spatial location of the nodes. In this paper, we look to extract spatially-near
communities in a social network. We introduce a new metric to measure the
quality of a community partition in a geolocated social networks called
"spatially-near modularity" a value that increases based on aspects of the
network structure but decreases based on the distance between nodes in the
communities. We then look to find an optimal partition with respect to this
measure - which should be an "ideal" community with respect to both social ties
and geographic location. Though an NP-hard problem, we introduce two heuristic
algorithms that attempt to maximize this measure and outperform non-geographic
community finding by an order of magnitude. Applications to counter-terrorism
are also discussed.


title: Reliability, calibration and metrology in ionizing radiation dosimetry

abstract:
  Radiation dosimetry systems are complex systems, comprised of a milieu of
components, designed for determining absorbed dose after exposure to ionizing
radiation. Although many materials serve as absorbing media for measurement,
thermoluminescent dosimeters represent some of the more desirable materials
available; yet, reliability studies have revealed a clear and definite
decrement in dosimeter sensitivity after repeated use. Unfortunately, repeated
use of any such material for absorbing media in ionizing radiation dosimetry
will in time experience performance decrements; thus, in order to achieve the
most accuracy and/or precision in dosimetry, it is imperative proper
compensation be made in calibration. Yet, analysis proves the majority of the
measured decrement in sensitivity experienced by dosimeters is attributable to
drift noise and not to any degradation in dosimeter performance, at least, not
to any great degree. In addition to investigating dosimeter reliability,
implications for metrological traceability and influences for calibration, this
monograph addresses certain errors in applied statistics, which are rather
alarming habits found in common usage throughout the radiation dosimetry
community. This monograph can also be considered a systems analysis of sorts;
because, attention to such key topics, so general and essential in nature,
produces an effective system analysis, where each principle covered aptly
applies to radiation dosimetry systems in general.


title: Towards Quantum Information Processing at the Attosecond Timescale

abstract:
  Coherent processing of quantum information and attosecond science had so far
little in common. We here show that recent data in high harmonic emission
reveal quantum information processing at the attosecond timescale. By observing
the interference pattern created by the spatiotemporal overlap of photons
emitted by two interfering electron paths we generate a photon Hadamard gate
and thus erase the electron-trajectory information. This allows the measurement
of the relative phase in electron-trajectory quantum superpositions and
establishes the era of electron-photon quantum coherence and entanglement at
the attosecond timescale of high-field physics.


title: Note on Archimedean property in ordered vector spaces

abstract:
  It is shown that an ordered vector space $X$ is Archimedean if and only if
$\inf\limits_{\tau\in\{\tau\}, y\in L}(x_\tau -y) \ = 0$ for any bounded
decreasing net $x_\tau\downarrow$ in $X$, where $L$ is the collection of all
lower bounds of $\{x_\tau\}_{\tau}$. We give also a characterization of the
almost Archimedean property of $X$ in terms of existence of a linear extension
of an additive mapping $T:Y_+\to X_+$ of the positive cone $Y_+$ of an ordered
vector space $Y$ into $X_+$.


title:
A System-Theoretic Clean Slate Approach to Provably Secure Ad Hoc
  Wireless Networking

abstract:
  Traditionally, wireless network protocols have been designed for performance.
Subsequently, as attacks have been identified, patches have been developed.
This has resulted in an "arms race" development process of discovering
vulnerabilities and then patching them. The fundamental difficulty with this
approach is that other vulnerabilities may still exist. No provable security or
performance guarantees can ever be provided.
  We develop a system-theoretic approach to security that provides a complete
protocol suite with provable guarantees, as well as proof of min-max optimality
with respect to any given utility function of source-destination rates. Our
approach is based on a model capturing the essential features of an adhoc
wireless network that has been infiltrated with hostile nodes. We consider any
collection of nodes, some good and some bad, possessing specified capabilities
vis-a-vis cryptography, wireless communication and clocks. The good nodes do
not know the bad nodes. The bad nodes can collaborate perfectly, and are
capable of any disruptive acts ranging from simply jamming to non-cooperation
with the protocols in any manner they please.
  The protocol suite caters to the complete life-cycle, all the way from birth
of nodes, through all phases of ad hoc network formation, leading to an
optimized network carrying data reliably. It provably achieves the min-max of
the utility function, where the max is over all protocol suites published and
followed by the good nodes, while the min is over all Byzantine behaviors of
the bad nodes. Under the protocol suite, the bad nodes do not benefit from any
actions other than jamming or cooperating.
  This approach supersedes much previous work that deals with several types of
attacks.


title: Components of spaces of surface group representations

abstract:
  We give a new lower bound on the number of connected components of the space
of representations of a surface group into the group of orientation preserving
homeomorphisms of the circle. Precisely, for the fundamental group of a genus g
surface, we show there are at least k^(2g) + 1 connected components containing
representations with Euler number (2g-2)/(k). We also show that certain
representations are rigid, meaning that all deformations lie in the same
semiconjugacy class. Our methods apply to representations of surface groups
into finite covers of PSL(2,R) and into Diff+(S^1) as well, in which case we
recover theorems of W. Goldman and J. Bowden.
  The key technique is an investigation of local maximality phenomena for
rotation numbers of products of circle homeomorphisms, using techniques of
Calegari-Walker. This is a new approach to studying deformation classes of
group actions on the circle, and may be of independent interest.


title: Informationally Incomplete Quantum Tomography

abstract:
  In quantum-state tomography on sources with quantum degrees of freedom of
large Hilbert spaces, inference of quantum states of light for instance, a
complete characterization of the quantum states for these sources is often not
feasible owing to limited resources. As such, the concepts of informationally
incomplete state estimation becomes important. These concepts are ideal for
applications to quantum channel/process tomography, which typically requires a
much larger number of measurement settings for a full characterization of a
quantum channel. Some key aspects of both quantum-state and quantum-process
tomography are arranged together in the form of a tutorial review article that
is catered to students and researchers who are new to the field of quantum
tomography, with focus on maximum-likelihood related techniques as instructive
examples to illustrate these ideas.


title: Radial Forcing and Edgar Allan Poe's Lengthening Pendulum

abstract:
  Inspired by Edgar Allan Poe's The Pit and the Pendulum, we investigate a
radially driven, lengthening pendulum. We first show that increasing the length
of an undriven pendulum at a uniform rate does not amplify the oscillations in
a manner consistent with the behavior of the scythe in Poe's story. We discuss
parametric amplification and the transfer of energy (through the parameter of
the pendulum's length) to the oscillating part of the system. In this manner
radial driving may easily and intuitively be understood, and the fundamental
concept applied in many other areas. We propose and show by a numerical model
that appropriately timed radial forcing can increase the oscillation amplitude
in a manner consistent with Poe's story. Our analysis contributes a
computational exploration of the complex harmonic motion that can result from
radially driving a pendulum, and sheds light on a mechanism by which
oscillations can be amplified parametrically. These insights should prove
especially valuable in the undergraduate physics classroom, where
investigations into pendulums and oscillations are commonplace.


title: Gas Electron Multipliers versus Multiwire Proportional Chambers

abstract:
  Gas Electron Multiplication technology is finding more and more applications
in beam instrumentation and at CERN these detectors have recently been adapted
for use in transverse profile measurements at several of our facilities. In the
experimental areas of CERN's Antiproton Decelerator, low energy Gas Electron
Multipliers successfully replaced all Multwire Proportional Chambers in 2012
and another detector type has now been developed for high energy applications
in the experimental areas of the SPS, totaling a potential of more than a
hundred profile detectors to be replaced by GEM detectors of different types.
This paper aims to describe the historical evolution of GEM technology by
covering the many different applications but with specific focus on its
potential to replace Multiwire Proportional Chambers for standard transverse
profile measurement.


title:
Quantum Backflow States from Eigenstates of the Regularized Current
  Operator

abstract:
  We present an exhaustive class of states with quantum backflow -- the
phenomenon in which a state consisting entirely of positive momenta may have
negative current and the probability flows in the opposite direction to the
momentum. They are characterized by a general function of momenta subject to
very weak conditions. Such a family of states is of interest in the light of a
recent experimental proposal to measure backflow. We find one particularly
simple state which has surprisingly large backflow -- about 41 percent of the
lower bound on flux derived by Bracken and Melloy. We study the eigenstates of
a regularized current operator and we show how some of these states, in a
certain limit, lead to our class of backflow states. This limit also clarifies
the correspondence between the spectrum of the regularized current operator,
which has just two non-zero eigenvalues in our chosen regularization, and the
usual current operator.


title:
Group Theory of Circular-Polarization Effects in Chiral Photonic
  Crystals with Four-Fold Rotation Axes, Applied to the Eight-Fold Intergrowth
  of Gyroid Nets

abstract:
  We use group or representation theory and scattering matrix calculations to
derive analytical results for the band structure topology and the scattering
parameters, applicable to any chiral photonic crystal with body-centered cubic
symmetry I432 for circularly-polarised incident light. We demonstrate in
particular that all bands along the cubic [100] direction can be identified
with the irreducible representations E+/-,A and B of the C4 point group. E+ and
E- modes represent the only transmission channels for plane waves with wave
vector along the ? line, and can be identified as non-interacting transmission
channels for right- (E-) and left-circularly polarised light (E+),
respectively. Scattering matrix calculations provide explicit relationships for
the transmission and reflectance amplitudes through a finite slab which
guarantee equal transmission rates for both polarisations and vanishing
ellipticity below a critical frequency, yet allowing for finite rotation of the
polarisation plane. All results are verified numerically for the so-called
8-srs geometry, consisting of eight interwoven equal-handed dielectric Gyroid
networks embedded in air. The combination of vanishing losses, vanishing
ellipticity, near-perfect transmission and optical activity comparable to that
of metallic meta-materials makes this geometry an attractive design for
nanofabricated photonic materials.


title: Numerical Boson Stars with a Single Killing Vector II: the D=3 Case

abstract:
  We complete the analysis of part I in this series (Ref.
\cite{Stotyn:2013yka}) by numerically constructing boson stars in 2+1
dimensional Einstein gravity with negative cosmological constant, minimally
coupled to a complex scalar field. These lower dimensional boson stars have
strikingly different properties than their higher dimensional counterparts,
most noticeably that there exists a finite central energy density, above which
an extremal BTZ black hole forms. In this limit, all of the scalar field
becomes enclosed by the horizon; it does not contract to a singularity, but
rather the origin remains smooth and regular and the solution represents a
spinning boson star trapped inside a degenerate horizon. Additionally, whereas
in higher dimensions the mass, angular momentum, and angular velocity all
display damped harmonic oscillations as functions of the central energy
density, in $D=3$ these quantities change monotonically up to the bound on the
central energy density. Some implications for the holographic dual of these
objects are discussed and it is argued that the boson star and extremal BTZ
black hole phases are dual to a spontaneous symmetry breaking at zero
temperature but finite energy scale.


title: Hadronic absorption cross sections of $B_{c}$

abstract:
  The cross sections of $B_{c}$\ absorption by $\pi $ mesons are calculated
using hadronic Lagrangian based on SU(5) flavor symmetry. Calculated cross
sections are found to be in range 2 to 7 mb and 0.2 to 2 mb for the processes
$B_{c}^{+}\pi \rightarrow DB$ and $B_{c}^{+}\pi \rightarrow D^{\ast}B^{\ast}$
respectively, when the monopole form factor is included. These results could be
useful in calculating production rate of $B_{c}$ meson in relativistic heavy
ion collisions.


title:
Group Theory of Chiral Photonic Crystals with 4-fold Symmetry: Band
  Structure and S-Parameters of Eight-Fold Intergrown Gyroid Nets

abstract:
  The Single Gyroid, or srs, nanostructure has attracted interest as a
circular-polarisation sensitive photonic material. We develop a group
theoretical and scattering matrix method, applicable to any photonic crystal
with symmetry I432, to demonstrate the remarkable chiral-optical properties of
a generalised structure called 8-srs, obtained by intergrowth of eight
equal-handed srs nets. Exploiting the presence of four-fold rotations, Bloch
modes corresponding to the irreducible representations E- and E+ are identified
as the sole and non-interacting transmission channels for right- and
left-circularly polarised light, respectively. For plane waves incident on a
finite slab of the 8-srs, the reflection rates for both circular polarisations
are identical for all frequencies and transmission rates are identical up to a
critical frequency below which scattering in the far field is restricted to
zero grating order. Simulations show the optical activity of the lossless
dielectric 8-srs to be large, comparable to metallic metamaterials,
demonstrating its potential as a nanofabricated photonic material.


title:
Accurate determination of electron-hole asymmetry and next-nearest
  neighbor hopping in graphene

abstract:
  The next-nearest neighbor hopping term t' determines a magnitude and, hence,
importance of several phenomena in graphene, which include self-doping due to
broken bonds and the Klein tunneling that in the presence of t' is no longer
perfect. Theoretical estimates for t' vary widely whereas a few existing
measurements by using polarization resolved magneto-spectroscopy have found
surprisingly large t', close or even exceeding highest theoretical values. Here
we report dedicated measurements of the density of states in graphene by using
high-quality capacitance devices. The density of states exhibits a pronounced
electron-hole asymmetry that increases linearly with energy. This behavior
yields t' approx -0.30 eV +-15%, in agreement with the high end of theory
estimates. We discuss the role of electron-electron interactions in determining
t' and overview phenomena which can be influenced by such a large value of t'.


title:
Randomized Quantization and Source Coding with Constrained Output
  Distribution

abstract:
  This paper studies fixed-rate randomized vector quantization under the
constraint that the quantizer's output has a given fixed probability
distribution. A general representation of randomized quantizers that includes
the common models in the literature is introduced via appropriate mixtures of
joint probability measures on the product of the source and reproduction
alphabets. Using this representation and results from optimal transport theory,
the existence of an optimal (minimum distortion) randomized quantizer having a
given output distribution is shown under various conditions. For sources with
densities and the mean square distortion measure, it is shown that this optimum
can be attained by randomizing quantizers having convex codecells. For
stationary and memoryless source and output distributions a rate-distortion
theorem is proved, providing a single-letter expression for the optimum
distortion in the limit of large block-lengths.


title:
Role of doped Ru in coercivity-enhanced La$_{0.6}$Sr$_{0.4}MnO$_3$ thin
  film studied by x-ray magnetic circular dichroism

abstract:
  The coercivity of La$_{1-x}$Sr$_x$MnO$_3$ thin films can be enhanced by Ru
substitution for Mn. In order to elucidate its mechanism, we performed soft
x-ray absorption and magnetic circular dichroism measurements at the Ru
M$_{2,3}$ and Mn L$_{2,3}$ edges. We found that the spin direction of Ru and Mn
are opposite and that Ru has a finite orbital magnetic moment. Cluster-model
analysis indicated that the finite orbital magnetic moment as well as the
reduced spin moment of Ru result from local lattice distortion caused by
epitaxial strain from the SrTiO$_3$ substrate in the presence of spin-orbit
interaction.


title: Higher order non-linear parameters with PLANCK

abstract:
  We investigate how higher order non-linear parameters affect lower order ones
through loop effects. We calculate the loop corrections up to two-loops and
explicitly show that the tree contribution is stable against loop terms in most
cases. We argue that, nevertheless, observational constraints on non-linear
parameters such as fNL and tauNL can also give a limit even for higher order
ones due to the loop contribution. We discuss these issues both for
single-source and multi-source cases.


title: On the role of interaction in sequential Monte Carlo algorithms

abstract:
  We introduce a general form of sequential Monte Carlo algorithm defined in
terms of a parameterized resampling mechanism. We find that a suitably
generalized notion of the Effective Sample Size (ESS), widely used to monitor
algorithm degeneracy, appears naturally in a study of its convergence
properties. We are then able to phrase sufficient conditions for time-uniform
convergence in terms of algorithmic control of the ESS, in turn achievable by
adaptively modulating the interaction between particles. This leads us to
suggest novel algorithms which are, in senses to be made precise, provably
stable and yet designed to avoid the degree of interaction which hinders
parallelization of standard algorithms. As a byproduct, we prove time-uniform
convergence of the popular adaptive resampling particle filter.


title:
Superconducting current and proximity effect in ABA and ABC multilayer
  graphene Josephson junctions

abstract:
  Using a numerical tight-binding approach based on the Chebyshev-Bogoliubov-de
Gennes method we describe Josephson junctions made of multilayer graphene
contacted by top superconducting gates. Both Bernal (ABA) and rhombohedral
(ABC) stacking are considered and we find that the type of stacking has a
strong effect on the proximity effect and the supercurrent flow. For both cases
the pair amplitude shows a polarization between dimer and non-dimer atoms,
being more pronounced for rhombohedral stacking. Even though the proximity
effect in non-dimer sites is enhanced when compared to single layer graphene,
we find that the supercurrent is suppressed. The spatial distribution of the
supercurrent shows that for Bernal stacking the current flows only in the
top-most layers while for rhombohedral stacking the current flows throughout
the whole structure.


title: Evolutionary Information Diffusion over Social Networks

abstract:
  Social networks have become ubiquitous in our daily life, as such it has
attracted great research interests recently. A key challenge is that it is of
extremely large-scale with tremendous information flow, creating the phenomenon
of "Big Data". Under such a circumstance, understanding information diffusion
over social networks has become an important research issue. Most of the
existing works on information diffusion analysis are based on either network
structure modeling or empirical approach with dataset mining. However, the
information diffusion is also heavily influenced by network users' decisions,
actions and their socio-economic connections, which is generally ignored in
existing works. In this paper, we propose an evolutionary game theoretic
framework to model the dynamic information diffusion process in social
networks. Specifically, we analyze the framework in uniform degree and
non-uniform degree networks and derive the closed-form expressions of the
evolutionary stable network states. Moreover, the information diffusion over
two special networks, Erd\H{o}s-R\'enyi random network and the
Barab\'asi-Albert scale-free network, are also highlighted. To verify our
theoretical analysis, we conduct experiments by using both synthetic networks
and real-world Facebook network, as well as real-world information spreading
dataset of Twitter and Memetracker. Experiments shows that the proposed game
theoretic framework is effective and practical in modeling the social network
users' information forwarding behaviors.


title: On Scale and Conformal Invariance in Four Dimensions

abstract:
  We study the implications of scale invariance in four-dimensional quantum
field theories. Imposing unitarity, we find that infinitely many matrix
elements vanish in a suitable kinematical configuration. This vanishing is a
nontrivial necessary condition for conformality. We provide an argument why
this is expected to be a sufficient condition as well, thereby linking scale
and conformal invariance in unitary theories. We also discuss possible
exceptions to our argument.


title:
Indian Buffet Game with Negative Network Externality and Non-Bayesian
  Social Learning

abstract:
  How users in a dynamic system perform learning and make decision become more
and more important in numerous research fields. Although there are some works
in the social learning literatures regarding how to construct belief on an
uncertain system state, few study has been conducted on incorporating social
learning with decision making. Moreover, users may have multiple concurrent
decisions on different objects/resources and their decisions usually negatively
influence each other's utility, which makes the problem even more challenging.
In this paper, we propose an Indian Buffet Game to study how users in a dynamic
system learn the uncertain system state and make multiple concurrent decisions
by not only considering the current myopic utility, but also taking into
account the influence of subsequent users' decisions. We analyze the proposed
Indian Buffet Game under two different scenarios: customers request multiple
dishes without budget constraint and with budget constraint. For both cases, we
design recursive best response algorithms to find the subgame perfect Nash
equilibrium for customers and characterize special properties of the Nash
equilibrium profile under homogeneous setting. Moreover, we introduce a
non-Bayesian social learning algorithm for customers to learn the system state,
and theoretically prove its convergence. Finally, we conduct simulations to
validate the effectiveness and efficiency of the proposed algorithms.


title: $\Upsilon$ absorption cross sections by nucleons

abstract:
  The cross sections of $\Upsilon $\ absorption by nucleons are calculated in
meson-baryon exchange model using an effective hadronic Lagrangian. Calculated
cross sections are found to peak near threshold followed by an increase which
tends to settle at large center of mass energy. Peak values are found in range
about 1.8 to 4 mb when cutoff parameter of monopole form factor is varied from
1.2 to 1.8 GeV. The results disagree with pQCD calculations but are consistent
with the effective value of the absorption cross section extracted from p-A
scattering data in E772 experiment at $\sqrt{s_{NN}}=39$ GeV. We use this data
value to find a best fit of the cutoff parameter which enables us provide
definite predictions for the values of $\Upsilon $ absorption cross sections by
nucleons for upcoming p-A scattering experiments at RHIC and LHC energies for
zero rapidity $b\bar{b}$ states. The results could be useful in studying the
effect of $\Upsilon $ absorption by nucleons at its production stage in
relativistic heavy-ion collision experiments. We also find that thermal
averaged values of total absorption cross sections are small enough to rule out
the effect of absorption of $\Upsilon $ by the comovers in the hadronic matter.


title: Soft beams: when capillarity induces axial compression

abstract:
  We study the interaction of an elastic beam with a liquid drop in the case
where bending and extensional effects are both present. We use a variational
approach to derive equilibrium equations and constitutive relation for the
beam. This relation is shown to include a term due to surface energy in
addition of the classical Young's modulus term, leading to a modification of
Hooke's law. At the triple point where solid, liquid, and vapor phases meet we
find that the external force applied on the beam is parallel to the
liquid-vapor interface. Moreover, in the case where solid-vapor and
solid-liquid interface energies do not depend on the extension state of the
beam, we show that the extension in the beam is continuous at the triple point
and that the wetting angle satisfy the classical Young-Dupr\'e relation.


title:
Stark Ionization of Atoms and Molecules within Density Functional
  Resonance Theory

abstract:
  We show that the energetics and lifetimes of resonances of finite systems
under an external electric field can be captured by Kohn--Sham density
functional theory (DFT) within the formalism of uniform complex scaling.
Properties of resonances are calculated self-consistently in terms of complex
densities, potentials and wavefunctions using adapted versions of the known
algorithms from DFT. We illustrate this new formalism by calculating ionization
rates using the complex-scaled local density approximation and exact exchange.
We consider a variety of atoms (H, He, Li and Be) as well as the hydrogen
molecule. Extensions are briefly discussed.


title: Kwant: a software package for quantum transport

abstract:
  Kwant is a Python package for numerical quantum transport calculations. It
aims to be an user-friendly, universal, and high-performance toolbox for the
simulation of physical systems of any dimensionality and geometry that can be
described by a tight-binding model. Kwant has been designed such that the
natural concepts of the theory of quantum transport (lattices, symmetries,
electrodes, orbital/spin/electron-hole degrees of freedom) are exposed in a
simple and transparent way: Defining a new simulation setup is very close to
describing the corresponding mathematical model. Kwant offers direct support
for calculations of transport properties (conductance, noise, scattering
matrix), dispersion relations, modes, wave functions, various Green's
functions, and out-of-equilibrium local quantities. Other computations
involving tight-binding Hamiltonians can be implemented easily thanks to its
extensible and modular nature. Kwant is free software available at
http://kwant-project.org/.


title: The number of $C_{2l}$-free graphs

abstract:
  One of the most basic questions one can ask about a graph $H$ is: how many
$H$-free graphs on $n$ vertices are there? For non-bipartite $H$, the answer to
this question has been well-understood since 1986, when Erd\H{o}s, Frankl and
R\"odl proved that there are $2^{(1 + o(1)) ex(n,H)}$ such graphs. For
bipartite graphs, however, much less is known: even the weaker bound
$2^{O(ex(n,H))}$ has been proven in only a few special cases: for cycles of
length four and six, and for some complete bipartite graphs.
  For even cycles, Bondy and Simonovits proved in the 1970s that ex$(n,C_{2l})
= O( n^{1 + 1/l} )$, and this bound is conjectured to be sharp up to the
implicit constant. In this paper we prove that the number of $C_{2l}$-free
graphs on $n$ vertices is at most $2^{O(n^{1 + 1/l})}$, confirming a conjecture
of Erd\H{o}s. Our proof uses the hypergraph container method, which was
developed recently (and independently) by Balogh, Morris and Samotij, and by
Saxton and Thomason, together with a new 'balanced supersaturation theorem' for
even cycles. We moreover show that there are at least $2^{(1 + c)ex(n,C_6)}$
$C_6$-free graphs on $n$ vertices for some $c > 0$ and infinitely many values
of $n$, disproving a well-known and natural conjecture. As a further
application of our method, we essentially resolve the so-called Tur\'an problem
on the Erd\H{o}s-R\'enyi random graph $G(n,p)$ for both even cycles and
complete bipartite graphs.


title:
Quantization of the Interacting Non-Hermitian Higher Order Derivative
  Field

abstract:
  The quantization of higher order time derivative theories including
interactions is unclear. In this paper in order to solve this problem, we
propose to consider a complex version of the higher order derivative theory and
map this theory to a real first order theory. To achieve this relationship, the
higher order derivative formulation must be complex since there is not a real
canonical transformation from this theory to a real first order theory with
stable interactions. In this manner, we work with a non-Hermitian higher order
time derivative theory. To quantize this complex theory, we introduce reality
conditions that allow us to map the complex higher order theory to a real one,
and we show that the resulting theory is regularizable and renormalizable for a
class of interactions.


title:
The VLT-FLAMES Tarantula Survey XII. Rotational velocities of the single
  O-type stars

abstract:
  Aims. Using ground based multi-object optical spectroscopy obtained in the
framework of the VLT-FLAMES Tarantula Survey (VFTS), we aim to establish the
(projected) rotational velocity distribution for a sample of 216 presumably
single O-type stars in 30 Doradus (30 Dor).
  Methods. We measured projected rotational velocities, \vrot, by means of a
Fourier transform method and a profile fitting method applied on a set of
isolated spectral lines. We also used an iterative deconvolution procedure to
infer the probability density, $\rm{P(\veq)}$, of the equatorial rotational
velocity, \veq.
  Results. The distribution of \vrot\ shows a two-component structure: a peak
around 80 \kms\ and a high-velocity tail extending up to $\sim$600 \kms. This
structure is also present in the inferred distribution $\rm{P(\veq)}$ with
around 80% of the sample having 0 $<$ \veq\, $\leq\, 300$ \kms\ and the other
20% distributed in the high-velocity region.
  Conclusions. Most of the stars in our sample rotate with a rate less than
20%\ of their break-up velocity. For the bulk of the sample, mass-loss in a
stellar wind and/or envelope expansion is not efficient enough to significantly
spin down these stars within the first few Myr of evolution. The presence of a
sizeable population of fast rotators is compatible with recent population
synthesis computations that investigate the influence of binary evolution on
the rotation rate of massive stars. Despite the fact that we have excluded
stars that show significant radial velocity variations, our sample may have
remained contaminated by post-interaction binary products. The fact that the
high-velocity tail may be preferentially (and perhaps even exclusively),
populated by post-binary interaction products, has important implications for
the evolutionary origin of systems that produce gamma-ray bursts.


title: Quantum theory of photonic crystals

abstract:
  In this paper, we have firstly presented a new quantum theory to study
one-dimensional photonic crystals. We give the quantum transform matrix,
quantum dispersion relation and quantum transmissivity, and compare them with
the classical dispersion relation and classical transmissivity. By the
calculation, we find the classical and quantum dispersion relation and
transmissivity are identical. The new approach can be studied two-dimensional
and three-dimensional photonic crystals.


title: Novel solutions to the tetrahedron equation

abstract:
  This is the English translation of the short note where the first nontrivial
tetrahedron relation (solution of the Zamolodchikov tetrahedron equation) with
variables on the edges was presented.


title: Oscillatory inflation in non-minimal derivative coupling model

abstract:
  Inflation during rapid oscillation of a scalar field in non-minimal
derivative coupling model is discussed. Cosmological perturbations originated
in this stage are studied and consistency of the results with observational
constraints coming from Planck 2013 data are investigated.


title: Line geometry and electromagnetism I: basic structures

abstract:
  Some key notions of line geometry are recalled, along with their application
to mechanics. It is then shown that most of the basic structures that one
introduces in the pre-metric formulation of electromagnetism can be interpreted
directly in terms of corresponding concepts in line geometry. The results are
summarized in a table.


title:
Investigating of longitudinal development parameters through air shower
  simulation by different hadronic models

abstract:
  In this work the simulation of the Extensive Air Showers was performed by
investigating the longitudinal development parameters (N and Xmax) by using a
system for air shower simulation which is called AIRES version 2.6.0 at the
energy range (10^14-10^19 eV) for different primary particles like (gamma,
electron, positron, proton and iron nuclei) and different zenith angles. The
comparison of simulated longitudinal profile was fulfilled for different
hadronic models (SIBYLL, QGSJET99 and SIBYLL S16).


title: B_{c} absorption cross sections by nucleons

abstract:
  The cross sections of $B_{c}$\ absorption by nucleons are calculated in
meson-baryon exchange model using hadronic Lagrangian based on SU(4)/SU(5)
flavor symmetries. The values of different coupling constants used in the model
are obtained from vector meson dominance model, QCD sum rule or SU(4)/SU(5)
flavor symmetries. Calculated values of cross sections are found to be
significantly different from the previous study in which b-flavored hadron
exchange is neglected. These results could be useful in calculating production
rate of $B_{c}$ meson in relativistic heavy ion collisions.


title:
A Chandra View Of Nonthermal Emission In The Northwestern Region Of
  Supernova Remnant RCW 86: Particle Acceleration And Magnetic Fields

abstract:
  The shocks of supernova remnants (SNRs) are believed to accelerate particles
to cosmic ray (CR) energies. The amplification of the magnetic field due to CRs
propagating in the shock region is expected to have an impact on both the
emission from the accelerated particle population, as well as the acceleration
process itself. Using a 95 ks observation with the Advanced CCD Imaging
Spectrometer (ACIS) onboard the Chandra X-ray Observatory, we map and
characterize the synchrotron emitting material in the northwestern region of
RCW 86. We model spectra from several different regions, filamentary and
diffuse alike, where emission appears dominated by synchrotron radiation. The
fine spatial resolution of Chandra allows us to obtain accurate emission
profiles across 3 different non-thermal rims in this region. The narrow width
(l = 10''-30'') of these filaments constrains the minimum magnetic field
strength at the post-shock region to be approximately 80 {\mu}G.


title:
Bound state energy of a Coulomb impurity in gapped bilayer graphene:
  "Hydrogen atom with a Mexican hat"

abstract:
  Application of a perpendicular electric field induces a band gap in bilayer
graphene, and it also creates a "Mexican hat" structure in the dispersion
relation. This structure has unusual implications for the hydrogen-like bound
state of an electron to a Coulomb impurity. We calculate the ground state
energy of this hydrogen-like state as a function of the applied interlayer
voltage and the effective fine structure constant. Unlike in the normal
hydrogen atom, the resulting wavefunction has many nodes even in the ground
state. Further, the electron state undergoes "atomic collapse" into the Dirac
continuum both at small and large voltage.


title: Exoplanet Transit Variability: Bow Shocks and Winds Around HD 189733b

abstract:
  By analogy with the solar system, it is believed that stellar winds will form
bow shocks around exoplanets. For hot Jupiters the bow shock will not form
directly between the planet and the star, causing an asymmetric distribution of
mass around the exoplanet and hence an asymmetric transit. As the planet orbits
thorough varying wind conditions, the strength and geometry of its bow shock
will change, thus producing transits of varying shape. We model this process
using magnetic maps of HD 189733 taken one year apart, coupled with a 3D
stellar wind model, to determine the local stellar wind conditions throughout
the orbital path of the planet. We predict the time-varying geometry and
density of the bow shock that forms around the magnetosphere of the planet and
simulate transit light curves. Depending on the nature of the stellar magnetic
field, and hence its wind, we find that both the transit duration and ingress
time can vary when compared to optical light curves. We conclude that
consecutive near-UV transit light curves may vary significantly and can
therefore provide an insight into the structure and evolution of the stellar
wind.