title: Quasi-Systematic Sampling From a Continuous Population

abstract:
  A specific family of point processes are introduced that allow to select
samples for the purpose of estimating the mean or the integral of a function of
a real variable. These processes, called quasi-systematic processes, depend on
a tuning parameter $r>0$ that permits to control the likeliness of jointly
selecting neighbor units in a same sample. When $r$ is large, units that are
close tend to not be selected together and samples are well spread. When $r$
tends to infinity, the sampling design is close to systematic sampling. For all
$r > 0$, the first and second-order unit inclusion densities are positive,
allowing for unbiased estimators of variance.
  Algorithms to generate these sampling processes for any positive real value
of $r$ are presented. When $r$ is large, the estimator of variance is unstable.
It follows that $r$ must be chosen by the practitioner as a trade-off between
an accurate estimation of the target parameter and an accurate estimation of
the variance of the parameter estimator. The method's advantages are
illustrated with a set of simulations.


title: The frequency dependence of scattering imprints on pulsar observations

abstract:
  Observations of pulsars across the radio spectrum are revealing a dependence
of the characteristic scattering time ($\tau$) on frequency, which is more
complex than the simple power law with a theoretically predicted power law
index. In this paper we investigate these effects using simulated pulsar data
at frequencies below 300 MHz. We investigate different scattering mechanisms,
namely isotropic and anisotropic scattering, by thin screens along the line of
sight, and the particular frequency dependent impact on pulsar profiles and
scattering time scales of each. We also consider how the screen shape, location
and offset along the line of sight lead to specific observable effects. We
evaluate how well forward fitting techniques perform in determining $\tau$. We
investigate the systematic errors in $\tau$ associated with the use of an
incorrect fitting method and with the determination of an off-pulse baseline.
Our simulations provide examples of average pulse profiles at various
frequencies. Using these we compute spectra of $\tau$ and mean flux for
different scattering setups. We identify setups that lead to deviations from
the simple theoretical picture. This work provides a framework for
interpretation of upcoming low frequency data, both in terms of modelling the
interstellar medium and understanding intrinsic emission properties of pulsars.


title: Searching for the optical counterparts of two young gamma-ray pulsars

abstract:
  We report on the first deep optical observations of two $\gamma$-ray pulsars,
both among the very first discovered by the {\em Fermi} Gamma-ray Space
Telescope. The two pulsars are the radio-loud PSR\, J1907+0602 in the TeV
pulsar wind nebula (PWN) MGRO\, J1908+06 and the radio-quiet PSR\, J1809$-$2332
in the "Taz" radio/X-ray PWN. These pulsars are relatively young and energetic
and have been both detected in the X-rays by \xmm, which makes them viable
targets for optical observations. We observed the pulsar fields in the B and V
bands with the Very Large Telescope (VLT) in June/July 2015 to search for their
optical counterparts. Neither of the two pulsars has been detected down to
$3\sigma$ limiting magnitudes of $m_{\rm v} \sim 26.9$ and $m_{\rm v} \sim
27.6$ for PSR\, J1907+0602 and PSR\, J1809$-$2332, respectively. We discuss
these results in the framework of the multi-wavelength emission properties of
pulsars.


title:
Study of spin-phonon coupling and magnetic field induced spin
  reorientation in polycrystalline multiferroic $GdFeO_3$

abstract:
  The present work reports the preparation of polycrystalline multiferroic
$GdFeO_3$ (GdFO) and characterization with x-ray diffraction (XRD),
magnetization, temperature dependent Raman spectroscopy, temperature and
magnetic field dependent $^{57}Fe$ M$\ddot{o}$ssbauer spectroscopy
measurements. The sample is found to be phase pure from Rietveld refinement of
XRD pattern. The M$\ddot{o}$ssbauer spectra measured in the presence of
external magnetic field show the signatures of field induced spin reorientation
transition, which are corroborated by magnetization measurements. From the
temperature dependent variation of internal hyperfine field, N$\grave{e}$el
transition temperature ($T_{N,Fe}$) of 672.5$\pm$0.2 K and critical exponent
($\beta$) of 0.333$\pm$0.003 is obtained. Temperature dependent (300 - 760 K)
Raman spectroscopy measurements show the signatures of spin-phonon coupling and
local structural re-arrangement across $T_{N,Fe}$.


title:
A robust derivation of the tight relationship of radio core dominance to
  inclination angle in high redshift 3CRR sources

abstract:
  It is believed that, in radio-loud active galactic nuclei (AGN), the core
radio flux density can be normalized to the flux density of the extended lobe
emission to infer the orientation of a radio source. However very little is
known about the reliability and precision of this method, and we are unaware of
any robust conversion recipe to infer the inclination from the core dominance.
Investigating whether or not the radio core dominance parameter R separates the
quasars from the radio-galaxies in the $z \ge$~1 3CRR catalog, we found
excellent agreement of R with optical type, infrared flux ratios and optical
polarization. This indicates that probably both R and optical classification
are very good orientation indicators, and the unified model is strongly
predictive for these objects. The relative number densities indicate
half-opening angles close to 60$^\circ$, as expected from large surveys. The
separations of optical types according to radio core dominance as well as
NIR/MIR ratios, which are essentially perfect, means that there can be only a
small dispersion of torus half-opening angles. Also, even though torus dust is
thought to be clumpy, there is an almost zero probability to see a type-1
source at high inclination. Finally, using only the Copernican Principle, i,e,
the assumption that solid angle is filled uniformly with source axis
orientations, we estimated a semi-empirical relation between core dominance and
AGN inclination. This makes it possible to use R to infer the inclination of a
source to an accuracy of $\sim$ 10 degrees or less, at least for this type of
object.


title: D3-D5 theories with unquenched flavors

abstract:
  We construct the string duals of the defect theories generated when N_f
flavor D5-branes intersect N_c color D3-branes along a 2+1 dimensional
subspace. We work in the Veneziano limit in which N_c and N_f are large and
N_f/N_c is fixed. By smearing the D5-branes, we find supergravity solutions
that take into account the backreaction of the flavor branes and preserve two
supercharges. When the flavors are massless the resulting metric displays an
anisotropic Lifshitz-like scale invariance. The case of massive quarks is also
considered.


title:
Intervalley scattering in MoS$_2$ imaged by two-photon photoemission
  with a high-harmonic probe

abstract:
  We report on the direct mapping of electron transfer in the momentum space of
bulk MoS$_2$ by means of time- and angle-resolved two-photon photoemission with
a high-harmonic probe. For this purpose, we have combined a high-repetition
rate high-harmonic source with tunable femtosecond pump pulses and a 3D ($k_x,
k_y, E$) electron spectrometer. We show that optical excitation slightly above
the A exciton resonance results in an immediate occupation of the conduction
band at $\overline{K}$ followed by an ultrafast transfer ($< 50$~fs) to the
conduction band minimum at $\overline{\Sigma}$. Both signals, at $\overline{K}$
and $\overline{\Sigma}$, do not vanish over the observed period of 400~fs. The
technique described here enables direct access to the charge transfer dynamics
in $k$-space and allows the study of decay times and decay channels in various
systems with dependence on the excess energy or helicity of the excitation.


title: What determines the observational differences of blazars?

abstract:
  We examine the scenario that the Doppler factor determines the observational
differences of blazars in this paper. Significantly negative correlations are
found between the observational synchrotron peak frequency and the Doppler
factor. After correcting the Doppler boosting, the intrinsic peak frequency
further has a tightly linear relation with the Doppler factor. It is more
interesting that this relation is consistent with the scenario that the black
hole mass governs both the bulk Lorentz factor and the synchrotron peak
frequency. In addition, the distinction of the kinetic jet powers between BL
Lacs and FSRQs disappears after the boosting factor $\delta^2$ is considered.
The negative correlation between the peak frequency and the observational
isotropic luminosity, known as the blazar sequence, also disappears after the
Doppler boosting is corrected. We also find that the correlation between the
Compton dominance and the Doppler factor exists for all types of blazars.
Therefore, this correlation is unsuitable to examine the external Compton
emission dominance.


title: On Failing Sets of the Interval-Passing Algorithm for Compressed Sensing

abstract:
  In this work, we analyze the failing sets of the interval-passing algorithm
(IPA) for compressed sensing. The IPA is an efficient iterative algorithm for
reconstructing a k-sparse nonnegative n-dimensional real signal x from a small
number of linear measurements y. In particular, we show that the IPA fails to
recover x from y if and only if it fails to recover a corresponding binary
vector of the same support, and also that only positions of nonzero values in
the measurement matrix are of importance for success of recovery. Based on this
observation, we introduce termatiko sets and show that the IPA fails to fully
recover x if and only if the support of x contains a nonempty termatiko set,
thus giving a complete (graph-theoretic) description of the failing sets of the
IPA. Finally, we present an extensive numerical study showing that in many
cases there exist termatiko sets of size strictly smaller than the stopping
distance of the binary measurement matrix; even as low as half the stopping
distance in some cases.


title: Geometric Mean Metric Learning

abstract:
  We revisit the task of learning a Euclidean metric from data. We approach
this problem from first principles and formulate it as a surprisingly simple
optimization problem. Indeed, our formulation even admits a closed form
solution. This solution possesses several very attractive properties: (i) an
innate geometric appeal through the Riemannian geometry of positive definite
matrices; (ii) ease of interpretability; and (iii) computational speed several
orders of magnitude faster than the widely used LMNN and ITML methods.
Furthermore, on standard benchmark datasets, our closed-form solution
consistently attains higher classification accuracy.


title:
Three years of harvest with the vector vortex coronagraph in the thermal
  infrared

abstract:
  For several years, we have been developing vortex phase masks based on
sub-wavelength gratings, known as Annular Groove Phase Masks. Etched onto
diamond substrates, these AGPMs are currently designed to be used in the
thermal infrared (ranging from 3 to 13 {\mu}m). Our AGPMs were first installed
on VLT/NACO and VLT/VISIR in 2012, followed by LBT/LMIRCam in 2013 and
Keck/NIRC2 in 2015. In this paper, we review the development, commissioning,
on-sky performance, and early scientific results of these new coronagraphic
modes and report on the lessons learned. We conclude with perspectives for
future developments and applications.


title: Stationarity of the inter-event power-law distributions

abstract:
  A number of human activities exhibit a bursty pattern, namely periods of very
high activity that are followed by rest periods. Records of these processes
generate time series of events whose inter-event times follow a probability
distribution that displays a fat tail. The grounds for such phenomenon are not
yet clearly understood. In the present work we use the freely available
Wikipedia editing records to unravel some features of this phenomenon. We show
that even though the probability to start editing is conditioned by the
circadian 24 hour cycle, the conditional probability for the time interval
between successive edits at a given time of the day is independent from the
latter. We confirm our findings with the activity of posting on the social
network Twitter. Our result suggests there is an intrinsic humankind scheduling
pattern: after overcoming the encumbrance to start an activity, there is a
robust distribution of new related actions, which does not depend on the time
of day.


title: Minimal model theory for relatively trivial log canonical pairs

abstract:
  We study relative log canonical pairs with relatively trivial log canonical
divisors. We fix such a pair $(X,\Delta)/Z$ and establish the minimal model
theory for the pair $(X,\Delta)$ assuming the minimal model theory for all
Kawamata log terminal pairs whose dimension is not greater than ${\rm dim}\,Z$.
We also show the finite generation of log canonical rings for log canonical
pairs of dimension five which are not of log general type.


title:
End-to-end optimization of nonlinear transform codes for perceptual
  quality

abstract:
  We introduce a general framework for end-to-end optimization of the
rate--distortion performance of nonlinear transform codes assuming scalar
quantization. The framework can be used to optimize any differentiable pair of
analysis and synthesis transforms in combination with any differentiable
perceptual metric. As an example, we consider a code built from a linear
transform followed by a form of multi-dimensional local gain control.
Distortion is measured with a state-of-the-art perceptual metric. When
optimized over a large database of images, this representation offers
substantial improvements in bitrate and perceptual appearance over fixed (DCT)
codes, and over linear transform codes optimized for mean squared error.


title:
Fast generation of weak lensing maps by the inverse-Gaussianization
  method

abstract:
  To take full advantage of the unprecedented power of upcoming weak lensing
surveys, understanding the noise, such as cosmic variance and geometry/mask
effects, is as important as understanding the signal itself. Accurately
quantifying the noise requires a large number of statistically independent
mocks for a variety of cosmologies. This is impractical for weak lensing
simulations, which are costly for simultaneous requirements of large box size
(to cover a significant fraction of the past light cone) and high resolution
(to robustly probe the small scale where most lensing signal resides).
Therefore fast mock generation methods are desired and are under intensive
investigation. We propose a new fast weak lensing map generation method, named
the inverse-Gaussianization method, based on the finding that a lensing
convergence field can be Gaussianized to excellent accuracy by a local
transformation [Yu et al, Phys. Rev. D 84, 023523 (2011)]. Given a simulation,
it enables us to produce as many as infinite statistically independent lensing
maps as fast as producing the simulation initial conditions. The proposed
method is tested against simulations for each tomography bin centered at lens
redshift $z \sim 0.5$, 1, and 2, with various statistics. We find that the
lensing maps generated by our method have reasonably accurate power spectra,
bispectra, and power spectrum covariance matrix. Therefore, it will be useful
for weak lensing surveys to generate realistic mocks. As an example of
application, we measure the probability distribution function of the lensing
power spectrum, from 16384 lensing maps produced by the inverse-Gaussianization
method.


title: An Extended Note on the Comparison-optimal Dual Pivot Quickselect

abstract:
  In this note the precise minimum number of key comparisons any dual-pivot
quickselect algorithm (without sampling) needs on average is determined. The
result is in the form of exact as well as asymptotic formul\ae{} of this number
of a comparison-optimal algorithm. It turns out that the main terms of these
asymptotic expansions coincide with the main terms of the corresponding
analysis of the classical quickselect, but still---as this was shown for
Yaroslavskiy quickselect---more comparisons are needed in the dual-pivot
variant. The results are obtained by solving a second order differential
equation for the generating function obtained from a recursive approach.


title: An analogy between optical turbulence and activator-inhibitor dynamics

abstract:
  The propagation of laser beams through madia with cubic nonlinear
polarization is part of a wide range of practical applications. The processes
that are involved are at the limit of extreme (cuasi-singular) concentration of
intensity and the transversal modulational instability, the saturation and
defocusing effect of the plasma generated through avalanche and multi-photon
(MPI) ionization are competing leading to a complicated pattern of intensity in
the transversal plane. This regime has been named \textquotedblleft optical
turbulence\textquotedblright and it has been studied in experiments and
numerical simulations. Led by the similarity of the portraits we have
investigated the possibility that the mechanism that underlies the creation of
the complex pattern of the intensity field is the manifestation of the dynamics
\textit{activator-inhibitor}. In a previous work we have considered a unique
connection, the \textit{complex Landau-Ginzburg equation}, a common ground for
the nonlinear Schrodinger equation (optical propagation) and reaction-diffusion
systems (activator-inhibitor). The present work is a continuation of this
investigation. We start from the exact integrability of the elementary
self-focusing propagation (\textit{gas Chaplygin with anomalous polytropic})
and show that the analytical model for the intensity can be extended on
physical basis to include the potential barrier separating two states of
equilibria and the drive due to competing Kerr and MPI nonlinearities. We
underline the variational structure and calculate the width of a branch of the
cluster of high intensity (when it is saturated at a finite value). Our result
is smaller but satisfactorily in the range of the experimental observations.


title: Hyperbolic complex contact structures on $\mathbb{C}^{2n+1}$

abstract:
  In this paper we construct complex contact structures on $\mathbb{C}^{2n+1}$
for any $n\ge 1$ with the property that every holomorphic Legendrian map
$\mathbb{C}\to \mathbb{C}^{2n+1}$ is constant. In particular, these contact
structures are not globally contactomorphic to the standard complex contact
structure on $\mathbb{C}^{2n+1}$.


title: A generalized maximal diameter sphere theorem

abstract:
  We prove that if a complete connected $n$-dimensional Riemannian manifold $M$
has radial sectional curvature at a base point $p\in M$ bounded from below by
the radial curvature function of a two-sphere of revolution $\widetilde M$
belonging to a certain class, then the diameter of $M$ does not exceed that of
$\widetilde M.$ Moreover, we prove that if the diameter of $M$ equals that of
$\widetilde M,$ then $M$ is isometric to the $n$-model of $\widetilde M.$ The
class of a two-sphere of revolution employed in our main theorem is very wide.
For example, this class contains both ellipsoids of prolate type and spheres of
constant sectional curvature. Thus our theorem contains both the maximal
diameter sphere theorem proved by Toponogov [9] and the radial curvature
version by the present author [2] as a corollary.


title: Crystal field states of Kondo lattice heavy fermions CeRuSn3 and CeRhSn3

abstract:
  Inelastic neutron scattering experiments have been carried out to determine
the crystal field states of the Kondo lattice heavy fermions CeRuSn3 and
CeRhSn3. Both the compounds crystallize in LaRuSn3-type cubic structure (space
group Pm-3n) in which the Ce atoms occupy two distinct crystallographic sites
with cubic (m-3) and tetragonal (-4m.2) point symmetries. The INS data of
CeRuSn3 reveal the presence of a broad excitation centered around 6-8 meV which
is accounted by a model based on crystal electric field (CEF) excitations. On
the other hand, the INS data of isostructural CeRhSn3 reveal three CEF
excitations around 7.0, 12.2 and 37.2 meV. The neutron intensity sum rule
indicates that the Ce ions at both cubic and tetragonal Ce sites are in Ce3+
state in both CeRuSn3 and CeRhSn3. The CEF level schemes for both the compounds
are deduced. We estimate the Kondo temperature T_K = 3.1(2) K for CeRuSn3 from
neutron quasielastic linewidth in excellent agreement with that determined from
the scaling of magnetoresistance which gives T_K = 3.2(1) K. For CeRhSn3 the
neutron quasielastic linewidth gives T_K = 4.6 K. For both CeRuSn3 and CeRhSn3,
the ground state of Ce3+ turns out to be a quartet for the cubic site and a
doublet for the tetragonal site.


title: Towards robust coupled field induced Josephson junctions

abstract:
  The concept of coupled robust field induced Josephson junctions placed in
complex electromagnetic environments is presented. Such structures are made by
polarization of superconducting nanostructures by magnetic fields. The
methodology of modeling of structures and possible implementations is
introduced. The presented scheme is expected to implement and describe both
classical and quantum computers with use of Josephson junction and artificial
evolution. In such cases one can obtain unexpected new topologies of circuits
that can contribute in enhancement of known and used circuit schemes.
Furthermore one can obtain the non-invasive detectors of moving charged
particles from robust field induced Josephson junctions which are illustrated
by examples.


title: Language classification from bilingual word embedding graphs

abstract:
  We study the role of the second language in bilingual word embeddings in
monolingual semantic evaluation tasks. We find strongly and weakly positive
correlations between down-stream task performance and second language
similarity to the target language. Additionally, we show how bilingual word
embeddings can be employed for the task of semantic language classification and
that joint semantic spaces vary in meaningful ways across second languages. Our
results support the hypothesis that semantic language similarity is influenced
by both structural similarity as well as geography/contact.


title:
Monitoring and Prediction in Smart Energy Systems via Multi-timescale
  Nexting

abstract:
  Reliable prediction of system status is a highly demanded functionality of
smart energy systems, which can enable users or human operators to react
quickly to potential future system changes. By adopting the multi-timescale
nexting method, we develop an architecture of human-in-the-loop energy control
system, which is capable of casting short-term predictive information about the
specific smart energy system. The developed architecture does either require a
system model nor additional acquisition of (sensor) data in the existing system
configuration. Our first experiments demonstrate the performance of the
proposed control architecture in an electrical heating system simulation. In
the second experiment, we verify the effectiveness of our developed structure
in simulating a heating system in a thermal model of a building, by employing
natural EnergyPlus temperature data.


title: Cooperative eigenmodes and scattering in 1D atomic arrays

abstract:
  Collective coupling between dipoles can dramatically modify the optical
response of a medium. Such effects depend strongly on the geometry of the
medium and the polarization of the light. Using a classical coupled dipole
model, here we investigate the simplest case of one dimensional (1D) arrays of
interacting atomic dipoles driven by a weak laser field. Changing the
polarization and direction of the driving field allows us to separately address
superradiant, subradiant, red-shifted, and blue-shifted eigenmodes, as well as
observe strong Fano-like interferences between different modes. The cooperative
eigenvectors can be characterized by the phase difference between nearest
neighbor dipoles, ranging from all oscillating in phase to all oscillating out
of phase with their nearest neighbors. Investigating the eigenvalue behavior as
a function of atom number and lattice spacing, we find that certain eigenmodes
of an infinite atomic chain have the same decay rate as a single atom between
two mirrors. The effects we observe provide a framework for collective control
of the optical response of a medium, giving insight into the behavior of more
complicated geometries, as well as providing further evidence for the dipolar
analog of cavity QED.


title:
Grant-free Rateless Multiple Access: A Novel Massive Access Scheme for
  Internet of Things

abstract:
  Rateless Multiple Access (RMA) is a novel non-orthogonal multiple access
framework that is promising for massive access in Internet of Things (IoT) due
to its high efficiency and low complexity. In the framework, after certain
\emph{registration}, each active user respectively transmits to the access
point (AP) randomly based on an assigned random access control function (RACf)
until receiving an acknowledgement (ACK). In this work, by exploiting the
intrinsic access pattern of each user, we propose a grant-free RMA scheme,
which no longer needs the registration process as in the original RMA, thus
greatly reduces the signalling overhead and system latency. Furthermore, we
propose a low-complexity joint iterative detection and decoding algorithm in
which the channel estimation, active user detection, and information decoding
are done simultaneously. Finally, we propose a method based on density
evolution (DE) to evaluate the system performance.


title:
Instability of the roll/streak structure induced by free-stream
  turbulence in pre-transitional Couette flow

abstract:
  Although the roll/streak structure is ubiquitous in pre-transitional
wall-bounded shear flow, this structure is linearly stable if the idealization
of laminar flow is made. Lacking an instability, the large transient growth of
the roll/streak structure has been invoked to explain its appearance as
resulting from chance occurrence in the free-stream turbulence (FST) of
perturbations configured to optimally excite it. However, there is an
alternative interpretation which is that FST interacts with the roll/streak
structure to destabilize it. Statistical state dynamics (SSD) provides analysis
methods for studying instabilities of this type which arise from interaction
between the coherent and incoherent components of turbulence. Stochastic
structural stability theory (S3T), which implements SSD in the form of a
closure at second order, is used to analyze the SSD modes arising from
interaction between the coherent streamwise invariant component and the
incoherent FST component of turbulence. The least stable S3T mode is
destabilized at a critical value of a parameter controlling FST intensity and a
finite amplitude roll/streak structure arises from this instability through a
bifurcation in this parameter. Although this bifurcation has analytical
expression only in SSD, it is closely reflected in both the dynamically similar
quasi-linear system, referred to as the restricted non-linear (RNL) system, and
in DNS. S3T also predicts a second bifurcation at a higher value of the
turbulent excitation parameter. This second bifurcation is shown to lead to
transition to turbulence. Bifurcation from a finite amplitude roll/streak
equilibrium provides a direct route to the turbulent state through the S3T
roll/streak instability.


title: Embedded WENO: a design strategy to improve existing WENO schemes

abstract:
  Embedded WENO methods utilize all adjacent smooth substencils to construct a
desirable interpolation. Conventional WENO schemes under-use this possibility
close to large gradients or discontinuities. We develop a general approach for
constructing embedded versions of existing WENO schemes. Embedded methods based
on the WENO schemes of Jiang and Shu (J. Comput. Phys. 126 (1996)) and on the
WENO-Z scheme of Borges et al. (J. Comput. Phys. 227 (2008)) are explicitly
constructed. Several possible choices are presented that result in either
better spectral properties or a higher order of convergence for sufficiently
smooth solutions. However, these improvements carry over to discontinuous
solutions. The embedded methods are demonstrated to be indeed improvements over
their standard counterparts by several numerical examples. All the embedded
methods presented have no added computational effort compared to their standard
counterparts.


title:
Statistical state dynamics-based analysis of the physical mechanisms
  sustaining and regulating turbulence in Couette flow

abstract:
  This paper describes a study of the self-sustaining process in
wall-turbulence based on a second order statistical state dynamics (SSD) model
of Couette flow. SSD models with this form are referred to as S3T models and
self-sustain turbulence with a mean flow and second order perturbation
structure similar to that obtained by DNS. The use of a SSD model to study the
physical mechanisms underlying turbulence has advantages over the traditional
approach of studying the dynamics of individual realizations of turbulence. One
advantage is that the analytical structure of SSD isolates and directly
expresses the interaction between the coherent mean flow and the incoherent
perturbation components of the turbulence. Isolation of the interaction between
these components reveals how this interaction underlies both the maintenance of
the turbulence variance by transfer of energy from the externally driven flow
to the perturbation components as well as the enforcement of the observed
statistical mean turbulent state by feedback regulation between the mean and
perturbation fields. Another advantage of studying turbulence using SSD models
is that the analytical structure of S3T turbulence can be completely
characterized. For example, turbulence in the S3T system is maintained by a
parametric growth mechanism. Furthermore, the equilibrium statistical state of
the turbulence can be demonstrated to be enforced by feedback regulation in
which transient growth of the incoherent perturbations episodically suppresses
coherent streak growth preventing runaway parametric growth of the incoherent
turbulent component. Using S3T to isolate these parametric growth and feedback
regulation mechanisms allows a detailed characterization of the dynamics of the
self-sustaining process in S3T turbulence with compelling implications for
understanding the mechanism of wall-turbulence.


title: Topological vacuum bubble by anyon braiding

abstract:
  According to a basic rule of fermionic and bosonic many-body physics, known
as the linked cluster theorem, physical observables are not affected by vacuum
bubbles, which represent virtual particles created from vacuum and
self-annihilating without interacting with real particles. Here, we show that
this conventional knowledge must be revised for anyons, quasiparticles that
obey fractional exchange statistics intermediate between fermions and bosons.
We find that a certain class of vacuum bubbles of Abelian anyons does affect
physical observables. They represent virtually excited anyons which wind around
real anyonic excitations. These topological bubbles result in a
temperature-dependent phase shift of Fabry-Perot interference patterns in the
fractional quantum Hall regime accessible in current experiments, thus
providing a tool for direct and unambiguous observation of elusive fractional
statistics.


title:
Asymptotic metric behavior of random Cayley graphs of finite abelian
  groups

abstract:
  Using methods of Marklof and Str\"ombergsson we establish several limit laws
for metric parameters of random Cayley graphs of finite abelian groups with
respect to a randomly chosen set of generators of a fixed size. Doing so we
settle a conjecture of Amir and Gurel-Gurevich.


title:
Intelligent Biohybrid Neurotechnologies: Are They Really What They
  Claim?

abstract:
  In the era of intelligent biohybrid neurotechnologies for brain repair, new
fanciful terms are appearing in the scientific dictionary to define what has so
far been unimaginable. As the emerging neurotechnologies are becoming
increasingly polyhedral and sophisticated, should we talk about evolution and
rank the intelligence of these devices?


title:
Rotation-k Affine-Power-Affine-like Multiple Substitution-Boxes for
  Secure Communication

abstract:
  Substitution boxes with thorough cryptographic strengths are essential for
the development of strong encryption systems. They are the only portions
capable of inducing nonlinearity in symmetric encryption systems. Bijective
substitution boxes having both high nonlinearities and high algebraic
complexities are the most desirable to thwart linear, differential and
algebraic attacks. In this paper, a method of constructing algebraically
complex and cryptographically potent multiple substitution boxes is proposed.
The multiple substitution boxes are synthesized by applying the concept of
rotation-k approach on the affine-power-affine structure. It is shown that the
rotation-k approach inherits all the features of affine-power-affine structure.
Performance assessment of all the proposed substitution boxes is done against
nonlinearity, strict avalanche criteria, bits independent criteria,
differential probability, linear approximation probability and algebraic
complexity. It has been found that the proposed substitution boxes have
outstanding cryptographic characteristics and outperform the various recent
substitution boxes.


title: Light extraction from 2D materials using liquid formed micro-lenses

abstract:
  The recent discovery of semiconducting two-dimensional materials has led to
the prediction of a revolution in the field of optoelectronics, driven by the
introduction of a series of new components that are just a few atoms thick. Key
remaining challenges for producing practical devices from these materials lie
in improving the coupling of light into and out of single atomic layers, and in
making these layers robust to the influence of their surrounding environment.
We present a solution to tackle both of these problems simultaneously, by
deterministically placing a micro-lens directly onto the surface of these
materials. These lenses are dynamically tuned to increase the coupling of
light, whilst controlling chromatic aberration, before being set in place with
UV light. We show that this approach enhances photoluminescence of tungsten
diselenide (WSe2) monolayers by up to 300%, and nearly doubles the imaging
resolution of the system. Furthermore, this solution fully encapsulates the
monolayer, preventing it from physical damage and degradation in air. The
optical solution we have developed could become a key enabling technology for
the mass production of ultra-thin optical devices, such as quantum light
emitting diodes.


title:
Almost mobility edges and existence of critical regions in
  one-dimensional quasiperiodic lattices

abstract:
  We study a one-dimensional quasiperiodic system described by the
Aubry-Andr\'e model in the small wave vector limit and demonstrate the
existence of almost mobility edges and critical regions in the system. It is
well known that the eigenstates of the Aubry-Andr\'e model are either extended
or localized depending on the strength of incommensurate potential $V$ being
less or bigger than a critical value $V_c$, and thus no mobility edge exists.
However, it was shown in a recent work that this conclusion does not hold true
when the wave vector $\alpha$ of the incommensurate potential is small, and for
the system with $V<V_c$, there exist almost mobility edges at the energy
$E_{c_{\pm}}$, which separate the robustly delocalized states from "almost
localized" states. We find that, besides $E_{c_{\pm}}$, there exist
additionally another energy edges $E_{c'_{\pm}}$, at which abrupt change of
inverse participation ratio occurs. By using the inverse participation ratio
and carrying out multifractal analyses, we identify the existence of critical
regions among $|E_{c_{\pm}}| \leq |E| \leq |E_{c'_{\pm}}|$ with the almost
mobility edges $E_{c_{\pm}}$ and $E_{c'_{\pm}}$ separating the critical region
from the extended and localized regions, respectively. We also study the system
with $V>V_c$, for which all eigenstates are localized states, but can be
divided into extended, critical and localized states in their dual space by
utilizing the self-duality property of the Aubry-Andr\'e model.


title:
Overcoming the sign problem in 1-dimensional QCD by new integration
  rules with polynomial exactness

abstract:
  In this paper we describe a new integration method for the groups $U(N)$ and
$SU(N)$, for which we verified numerically that it is polynomially exact for
$N\le 3$. The method is applied to the example of 1-dimensional QCD with a
chemical potential. We explore, in particular, regions of the parameter space
in which the sign problem appears due the presence of the chemical potential.
While Markov Chain Monte Carlo fails in this region, our new integration method
still provides results for the chiral condensate on arbitrary precision,
demonstrating clearly that it overcomes the sign problem. Furthermore, we
demonstrate that our new method leads to orders of magnitude reduced errors
also in other regions of parameter space.


title:
Adaptive Artificial Intelligence in Games: Issues, Requirements, and a
  Solution through Behavlets-based General Player Modelling

abstract:
  We present the last of a series of three academic essays which deal with the
question of how and why to build a generalized player model. We propose that a
general player model needs parameters for subjective experience of play,
including: player psychology, game structure, and actions of play. Based on
this proposition, we pose three linked research questions: RQ1 what is a
necessary and sufficient foundation to a general player model?; RQ2 can such a
foundation improve performance of a computational intelligence- based player
model?; and RQ3 can such a player model improve efficacy of adaptive artificial
intelligence in games?
  We set out the arguments behind these research questions in each of the three
essays, presented as three preprints. The third essay, in this preprint,
presents the argument that adaptive game artificial intelligence will be
enhanced by a generalised player model. This is because games are inherently
human artefacts which therefore, require some encoding of the human perspective
in order to effectively autonomously respond to the individual player. The
player model informs the necessary constraints on the adaptive artificial
intelligence. A generalised player model is not only more efficient than a
per-game solution, but also allows comparison between games which makes it a
useful tool for studying play in general. We describe the concept and meaning
of an adaptive game. We propose requirements for functional adaptive AI,
arguing from first principles drawn from the games research literature. We
propose solutions to these requirements, based on a formal model approach to
our existing 'Behavlets' method for psychologically-derived player modelling:
  Cowley, B., & Charles, D. (2016). Behavlets: a Method for Practical Player
Modelling using Psychology-Based Player Traits and Domain Specific Features.
User Modeling and User-Adapted Interaction, 26(2), 257-306.


title:
Correction of distortion for optimal image stacking in Wide Field
  Adaptive Optics: Application to GeMS data

abstract:
  The advent of Wide Field Adaptive Optics (WFAO) systems marks the beginning
of a new era in high spatial resolution imaging. The newly commissioned Gemini
South Multi-Conjugate Adaptive Optics System (GeMS) combined with the infrared
camera Gemini South Adaptive Optics Imager (GSAOI), delivers quasi
diffraction-limited images over a field of 2 arc-minutes across. However,
despite this excellent performance, some variable residues still limit the
quality of the analyses. In particular, distortions severely affect GSAOI and
become a critical issue for high-precision astrometry and photometry. In this
paper, we investigate an optimal way to correct for the distortion following an
inverse problem approach. Formalism as well as applications on GeMS data are
presented.


title: Edge correlation function of the 8-vertex model when $a+c = b+d$

abstract:
  This paper is devoted to the 8-vertex model and its edge correlation
function. In some particular (integrable) cases, we find a closed form of the
edge correlation function and we deduce also its asymptotic. In addition, we
quantify influence of boundary conditions on this function.
  To do this, we introduce a system of particles in interaction related to the
8-vertex model. This system, studied using various tools from analytic
combinatorics, random walks and conics, permits to compute the correlation
function. To study the influence of boundary conditions, we involve
probabilistic cellular automata of order 2.


title: Enumerative Aspects of Nullstellensatz Certificates

abstract:
  Using polynomial equations to model combinatorial problems has been a popular
tool both in computational combinatorics as well as an approach to proving new
theorems. In this paper, we look at several combinatorics problems modeled by
systems of polynomial equations satisfying special properties. If the equations
are infeasible, Hilbert's Nullstellensatz gives a certificate of this fact.
These certificates have been studied and exhibit combinatorial meaning. In this
paper, we generalize some known results and show that the Nullstellensatz
certificate can be viewed as enumerating combinatorial structures. As such,
Gr\"obner basis algorithms for solving these decision problems may implicitly
be solving the enumeration problem as well.


title: Tycho Brahe, Abu Mashar, and the comet beyond Venus (ninth century A.D.)

abstract:
  From his observations of the A.D. 1572 super-nova and the A.D. 1577 comet,
Tycho Brahe concluded that such transient celestial objects are outside the
Earth's atmosphere, and he quoted the 9th century A.D. Persian astrologer and
astronomer Abu Mashar: Dixit Albumasar, Cometa supra Venerem visus fuit, i.e.
that he had reported much earlier that comets were seen beyond Venus. However,
even from a more detailed Latin translation, the observations and logic behind
Abu Mashar's conclusion were not understandable. We present here the original
Arabic text (MS Ankara, Saib 199) together with our translation and
interpretation: Abu Mashar reported that he had observed Venus in (or projected
onto) the tail of a comet and concluded that the comet was behind Venus,
because he had observed the extinction of Venus due to the cometary tail to be
negligible (light of Venus was unimpaired). He then concluded that the comet
would be located behind Venus. He also mentioned that others had observed
Jupiter and Saturn in cometary tails, so that those comets would even be
located beyond those two outer planets - in the sphere of the stars. The dates
of the observed close conjunctions were not mentioned; using known orbital
elements for a few comets, we found a few close conjunctions between comets and
planets from A.D. 770 to 868, but we cannot be sure regarding which
conjunctions were reported. While the argument of Abu Mashar is not correct (as
cometary tails are optically thin), parts of the conclusion - namely that
comets are outside the Earth atmosphere and beyond the moon - is correct. This
may have helped Tycho Brahe to come to his revolutionary conclusion.


title:
Asymptotic behaviour for a class of non-monotone delay differential
  systems with applications

abstract:
  The paper concerns a class of $n$-dimensional non-autonomous delay
differential equations obtained by adding a non-monotone delayed perturbation
to a linear homogeneous cooperative system of ordinary differential equations.
This family covers a wide set of models used in structured population dynamics.
By exploiting the stability and the monotone character of the linear ODE, we
establish sufficient conditions for both the extinction of all the populations
and the permanence of the system. In the case of DDEs with autonomous
coefficients (but possible time-varying delays), sharp results are obtained,
even in the case of a reducible community matrix. As a sub-product, our results
improve some criteria for autonomous systems published in recent literature. As
an important illustration, the extinction, persistence and permanence of a
non-autonomous Nicholson system with patch structure and multiple
time-dependent delays are analysed.


title:
Big data challenges for the social sciences: from society and opinion to
  replications

abstract:
  Big Data dealing with the social produce predictive correlations for the
benefit of brands and web platforms. Beyond "society" and "opinion" for which
the text lays out a genealogy, appear the "traces" that must be theorized as
"replications" by the social sciences in order to reap the benefits of the
uncertain status of entities' widespread traceability. High frequency
replications as a collective phenomenon did exist before the digital networks
emergence but now they leave traces that can be computed. The third generation
of Social Sciences currently emerging must assume the specific nature of the
world of data created by digital networks, without reducing them to the
categories of the sciences of "society" or "opinion". Examples from recent
works on Twitter and other digital corpora show how the search for structural
effects or market-style trade-offs are prevalent even though insights about
propagation, virality and memetics could help build a new theoretical
framework.


title:
Robust Multigrid for Isogeometric Analysis Based on Stable Splittings of
  Spline Spaces

abstract:
  We present a robust and efficient multigrid method for single-patch
isogeometric discretizations using tensor product B-splines of maximum
smoothness. Our method is based on a stable splitting of the spline space into
a large subspace of interior splines which satisfy a robust inverse inequality,
as well as one or several smaller subspaces which capture the boundary effects
responsible for the spectral outliers which occur in Isogeometric Analysis. We
then construct a multigrid smoother based on an additive subspace correction
approach, applying a different smoother to each of the subspaces. For the
interior splines, we use a mass smoother, whereas the remaining components are
treated with suitably chosen Kronecker product smoothers or direct solvers.
  We prove that the resulting multigrid method exhibits iteration numbers which
are robust with respect to the spline degree and the mesh size. Furthermore, it
can be efficiently realized for discretizations of problems in arbitrarily high
geometric dimension. Some numerical examples illustrate the theoretical results
and show that the iteration numbers also scale relatively mildly with the
problem dimension.


title: Black holes in Einstein-Maxwell Theory

abstract:
  We prove variants of known singularity theorems ensuring the existence of a
region of finite lifetime that are particularly well applicable if the solution
admits a conformal extension, a property satisfied e.g. by maximal Cauchy
developments of Einstein-Maxwell initial values close to the trivial ones.


title:
A Markov Chain Model for the Decoding Probability of Sparse Network
  Coding

abstract:
  Random Linear Network Coding (RLNC) has been proved to offer an efficient
communication scheme, leveraging an interesting robustness against packet
losses. However, it suffers from a high computational complexity and some novel
approaches, which follow the same idea, have been recently proposed. One of
such solutions is Tunable Sparse Network Coding (TSNC), where only few packets
are combined in each transmissions. The amount of data packets to be combined
in each transmissions can be set from a density parameter/distribution, which
could be eventually adapted. In this work we present an analytical model that
captures the performance of SNC on an accurate way. We exploit an absorbing
Markov process where the states are defined by the number of useful packets
received by the decoder, i.e the decoding matrix rank, and the number of
non-zero columns at such matrix. The model is validated by means of a thorough
simulation campaign, and the difference between model and simulation is
negligible. A mean square error less than $4 \cdot 10^{-4}$ in the worst cases.
We also include in the comparison some of more general bounds that have been
recently used, showing that their accuracy is rather poor. The proposed model
would enable a more precise assessment of the behavior of sparse network coding
techniques. The last results show that the proposed analytical model can be
exploited by the TSNC techniques in order to select by the encoder the best
density as the transmission evolves.


title: Groups whose character degree graph has diameter three

abstract:
  Let \(G\) be a finite group, and let \(\Delta(G)\) denote the \emph{prime
graph} built on the set of degrees of the irreducible complex characters of
\(G\). It is well known that, whenever \(\Delta(G)\) is connected, the diameter
of \(\Delta(G)\) is at most \(3\). In the present paper, we provide a
description of the finite solvable groups for which the diameter of this graph
attains the upper bound. This also enables us to confirm a couple of
conjectures proposed by M.L. Lewis.


title: Jet reconstruction at high-energy lepton colliders

abstract:
  In this paper we study the performance in $e^+e^-$ collisions of classical
$e^+e^-$ jet reconstruction algorithms, longitudinally invariant algorithms and
the recently-proposed Valencia algorithm. The study includes a comparison of
perturbative and non-perturbative jet energy corrections and the response under
realistic background conditions. Several algorithms are benchmarked with a
detailed detector simulation at $\sqrt{s}= 3$~\tev. We find that the classical
$e^+e^-$ algorithms, with or without beam jets, have the best response, but are
inadequate in environments with non-negligible background. The Valencia
algorithm and longitudinally invariant $k_t$ algorithms have a much more robust
performance, with a slight advantage for the former.


title: Effective Theory for Electroweak Doublet Dark Matter

abstract:
  We perform a detailed study of an effective field theory which includes the
Standard Model particle content extended by a pair of Weyl fermionic
SU(2)-doublets with opposite hypercharges. A discrete symmetry guarantees that
a linear combination of the doublet components is stable and can act as a
candidate particle for Dark Matter. The dark sector fermions interact with the
Higgs and gauge bosons through renormalizable $d=4$ operators, and
non-renormalizable $d=5$ operators that appear after integrating out extra
degrees of freedom above the TeV scale. We study collider, cosmological and
astrophysical probes for this effective theory of Dark Matter. We find that a
WIMP with a mass nearby to the electroweak scale, and thus observable at LHC,
is consistent with collider and astrophysical data only when fairly large
magnetic dipole moment transition operators with the gauge bosons exist,
together with moderate Yukawa interactions.


title:
Periodic solutions for a non-monotone family of delayed differential
  equations with applications to Nicholson systems

abstract:
  For a family of $n$-dimensional periodic delay differential equations which
encompasses a broad set of models used in structured population dynamics, the
existence of a positive periodic solution is obtained under very mild
conditions. The proof uses the Schauder fixed point theorem and relies on the
permanence of the system. A general criterion for the existence of a positive
periodic solution for Nicholson's blowflies periodic systems (with both
distributed and discrete time-varying delays) is derived as a simple
application of our main result, generalizing the few existing results
concerning multi-dimensional Nicholson models.
  In the case of a Nicholson system with discrete delays all multiples of the
period, the global attractivity of the positive periodic solution is further
analyzed, improving results in recent literature.


title: An empirical comparison of global and local functional depths

abstract:
  A functional data depth provides a center-outward ordering criterion which
allows the definition of measures such as median, trimmed means, central
regions or ranks in a functional framework. A functional data depth can be
global or local. With global depths, the degree of centrality of a curve $x$
depends equally on the rest of the sample observations, while with local
depths, the contribution of each observation in defining the degree of
centrality of $x$ decreases as the distance from $x$ increases. We empirically
compare the global and the local approaches to the functional depth problem
focusing on three global and two local functional depths. First, we consider
two real data sets and show that global and local depths may provide different
insights. Second, we use simulated data to show when we should expect
differences between a global and a local approach to the functional depth
problem.


title:
Entanglement, coherence, and redistribution of quantum resources in
  double spontaneous downconversion processes

abstract:
  We study the properties of bi-squeezed tripartite Gaussian states created by
two spontaneous parametric down-conversion processes that share a common idler.
We give a complete description of the quantum correlations across of all
partitions, as well as of the genuine multipartite entanglement, obtaining
analytical expressions for most of the quantities of interest. We find that the
state contains genuine tripartite entanglement, in addition to the bipartite
entanglement among the modes that are directly squeezed. We also investigate
the effect of homodyne detection of the photons in the common idler mode, and
analyse the final reduced state of the remaining two signal modes. We find that
this measurement leads to a conversion of the coherence of the two signal modes
into entanglement, a phenomenon that can be regarded as a redistribution of
quantum resources between the modes. The applications of these results to
quantum optics and circuit quantum electrodynamics platforms are also
discussed.


title:
Quasi-analytical solutions of hybrid platform and the optimization of
  highly sensitive thin-film sensors for terahertz radiation

abstract:
  We present quasi-analytical solutions (QANS) of hybrid platform (HP)
comprising metallic grating (MG) and stacked-dielectric layers for terahertz
(THz) radiation. The QANS are validated by finite difference time domain
simulation. It is found that the Wood anomalies induce the high-order spoof
surface plasmon resonances in the HP. The QANS are applied to optimize new
perfect absorber for THz sensing of large-area thin film with ultrahigh figure
of merit reaching fifth order of magnitude for the film thickness 0.0001p (p:
MG period). The first-order Wood's anomaly of the insulator layer and the
Fabry-Perot in the slit's cavity account for the resonance of the perfect
absorber. The QANS and the new perfect absorber may lead to highly sensitive
and practical nano-film refractive index sensor for THz radiation.


title:
Lettere scritte da Thomas Archer Hirst a Luigi Cremona dal 1865 al 1892
  conservate presso l'Istituto Mazziniano di Genova

abstract:
  The content of this paper is the noted transcription of 84 letters that
Thomas Archer Hirst wrote to Luigi Cremona and of 2 letters that Cremona wrote
to Hirst between 1865 and 1892. The correspondence is stored at the Istituto
Mazziniano, Museo del Risorgimento in Genova and is now available at
www.luigi-cremona.it
  -----
  La corrispondenza qui riprodotta, composta da 84 lettere scritte da Thomas
Archer Hirst a Luigi Cremona e da 2 lettere scritte da Cremona a Hirst tra il
1865 e il 1892, si trova a Genova (Istituto Mazziniano, Museo del Risorgimento)
e ora anche sul sito www.luigi-cremona.it


title: Deep Cascaded Bi-Network for Face Hallucination

abstract:
  We present a novel framework for hallucinating faces of unconstrained poses
and with very low resolution (face size as small as 5pxIOD). In contrast to
existing studies that mostly ignore or assume pre-aligned face spatial
configuration (e.g. facial landmarks localization or dense correspondence
field), we alternatingly optimize two complementary tasks, namely face
hallucination and dense correspondence field estimation, in a unified
framework. In addition, we propose a new gated deep bi-network that contains
two functionality-specialized branches to recover different levels of texture
details. Extensive experiments demonstrate that such formulation allows
exceptional hallucination quality on in-the-wild low-res faces with significant
pose and illumination variations.


title:
A Batch, Off-Policy, Actor-Critic Algorithm for Optimizing the Average
  Reward

abstract:
  We develop an off-policy actor-critic algorithm for learning an optimal
policy from a training set composed of data from multiple individuals. This
algorithm is developed with a view towards its use in mobile health.


title:
VBCA: A Virtual Forces Clustering Algorithm for Autonomous Aerial Drone
  Systems

abstract:
  We consider the positioning problem of aerial drone systems for efficient
three-dimensional (3-D) coverage. Our solution draws from molecular geometry,
where forces among electron pairs surrounding a central atom arrange their
positions. In this paper, we propose a 3-D clustering algorithm for autonomous
positioning (VBCA) of aerial drone networks based on virtual forces. These
virtual forces induce interactions among drones and structure the system
topology. The advantages of our approach are that (1) virtual forces enable
drones to self-organize the positioning process and (2) VBCA can be implemented
entirely localized. Extensive simulations show that our virtual forces
clustering approach produces scalable 3-D topologies exhibiting near-optimal
volume coverage. VBCA triggers efficient topology rearrangement for an altering
number of nodes, while providing network connectivity to the central drone. We
also draw a comparison of volume coverage achieved by VBCA against existing
approaches and find VBCA up to 40\% more efficient.


title:
YSO jets in the Galactic Plane from UWISH2: III - Jets and Outflows in
  Cassiopeia and Auriga

abstract:
  We present the analysis of 35.5 square degrees of images in the 1-0S(1) line
of H2 from the UK Widefield Infrared Survey for H2 (UWISH2) towards Cassiopeia
and Auriga. We have identified 98 Molecular Hydrogen emission-line Objects
(MHOs) driven by Young Stellar Objects, 60% of which are bipolar outflows and
all are new discoveries. We estimate that the UWISH2 extended emission object
catalogue contains fewer than % false positives and is complete at the 95%
level for jets and outflows brighter than the UWISH2 detection limit. We
identified reliable driving source candidates for three quarters of the
detected outflows, 40% of which are associated with groups and clusters of
stars. The driving source candidates are 20% protostars, the remainder are
CTTSs. We also identified 15 new star cluster candidates near MHOs in the
survey area.
  We find that the typical outflow identified in the sample has the following
characteristics: the position angles are randomly orientated; bipolar outflows
are straight within a few degrees; the two lobes are slightly asymmetrical in
length and brightness; the length and brightness of the lobes are not
correlated; typical time gaps between major ejections of material are 1-3kyr,
hence FU-Ori or EX-Ori eruptions are most likely not the cause of these, but we
suggest MNors as a possible source. Furthermore, we find that outflow lobe
length distributions are statistically different from the widely used total
length distributions. There are a larger than expected number of bright
outflows indicating that the flux distribution does not follow a power law.


title: Deformed Virasoro algebras from elliptic quantum algebras

abstract:
  We revisit the construction of deformed Virasoro algebras from elliptic
quantum algebras of vertex type, generalizing the bilinear trace procedure
proposed in the 90's. It allows us to make contact with the vertex operator
techniques that were introduced separately at the same period. As a by-product,
the method pinpoints two critical values of the central charge for which the
center of the algebra is extended, as well as (in the $gl(2)$ case) a Liouville
formula.


title: False confidence, non-additive beliefs, and valid statistical inference

abstract:
  Statistics has made tremendous advances since the times of Fisher, Neyman,
Jeffreys, and others, but the fundamental and practically relevant questions
about probability and inference that puzzled our founding fathers remain
unanswered. To bridge this gap, I propose to look beyond the two dominating
schools of thought and ask the following three questions: what do scientists
need out of statistics, do the existing frameworks meet these needs, and, if
not, how to fill the void? To the first question, I contend that scientists
seek to convert their data, posited statistical model, etc., into calibrated
degrees of belief about quantities of interest. To the second question, I argue
that any framework that returns additive beliefs, i.e., probabilities,
necessarily suffers from {\em false confidence}---certain false hypotheses tend
to be assigned high probability---and, therefore, risks systematic bias. This
reveals the fundamental importance of {\em non-additive beliefs} in the context
of statistical inference. But non-additivity alone is not enough so, to the
third question, I offer a sufficient condition, called {\em validity}, for
avoiding false confidence, and present a framework, based on random sets and
belief functions, that provably meets this condition. Finally, I discuss
characterizations of p-values and confidence intervals in terms of valid
non-additive beliefs, which imply that users of these classical procedures are
already following the proposed framework without knowing it.


title:
Signature of topological transition in persistent current in a Dirac
  Ring

abstract:
  We study the persistent current in a one dimensional Dirac ring and show that
the change of spin current with respect to an applied perpendicular electric
field can be used to identify the topological phases. We further study the
effect of Rashba spin orbit coupling and show that the Aharonov-Casher phase
appearing due to Rashba spin orbit coupling vanishes in topologically
nontrivial regime and thus can identify the topological phases. This
Aharonov-Casher phase causes a finite spin-valley current in presence of valley
mixing perturbation and is thus useful to detect the topological phases even in
presence of such impurity.


title: On The Energy Variant of the Sum-Product Conjecture

abstract:
  We prove new exponents for the energy version of the Erd\H{o}s-Szemer\'edi
sum-product conjecture, raised by Balog and Wooley. They match the previously
established milestone values for the standard formulation of the question, both
for general fields and the special case of real or complex numbers, and appear
to be the best ones attainable within the currently available technology.
Further results are obtained about multiplicative energies of additive shifts
and a strengthened energy version of the "few sums, many products" inequality
of Elekes and Ruzsa. The latter inequality enables us to obtain a minor
improvement of the state-of the art sum-product exponent over the reals due to
Konyagin and the second author, up to $\frac{4}{3}+\frac{1}{1509}$. An
application of energy estimates to an instance of arithmetic growth in prime
residue fields is presented.


title: Solution landscapes in nematic microfluidics

abstract:
  We study the static equilibria of a simplified Leslie--Ericksen model for a
unidirectional uniaxial nematic flow in a prototype microfluidic channel, as a
function of the pressure gradient $\mathcal{G}$ and inverse anchoring strength,
$\mathcal{B}$. We numerically find multiple static equilibria for admissible
pairs $(\mathcal{G}, \mathcal{B})$ and classify them according to their winding
numbers and stability. The case $\mathcal{G}=0$ is analytically tractable and
we numerically study how the solution landscape is transformed as $\mathcal{G}$
increases. We study the one-dimensional dynamical model, the sensitivity of the
dynamic solutions to initial conditions and the rate of change of $\mathcal{G}$
and $\mathcal{B}$. We provide a physically interesting example of how the time
delay between the applications of $\mathcal{G}$ and $\mathcal{B}$ can determine
the selection of the final steady state.


title: Fekete polynomials and shapes of Julia sets

abstract:
  We prove that a nonempty, proper subset $S$ of the complex plane can be
approximated in a strong sense by polynomial filled Julia sets if and only if
$S$ is bounded and $\hat{\mathbb{C}} \setminus \textrm{int}(S)$ is connected.
The proof that such a set is approximable by filled Julia sets is constructive
and relies on Fekete polynomials. Illustrative examples are presented. We also
prove an estimate for the rate of approximation in terms of geometric and
potential theoretic quantities.


title: Mixing, malnormal subgroups and cohomology in degree one

abstract:
  The aim of the current paper is to explore the implications on the group $G$
of the non-vanishing of the cohomology in degree one of one of its
representation $\pi$, given some mixing conditions on $\pi$. In one direction,
harmonic cocycles are used to show that the FC-centre should be finite (for
mildly mixing unitary representations). Next, for any subgroup $H<G$, $H$ will
either be "small", almost-malnormal or $\pi_{|H}$ also has non-trivial
cohomology in degree one (in this statement, "small", reduced vs unreduced
cohomology and unitary vs generic depend on the mixing condition). The notion
of q-normal subgroups is an important ingredient of the proof and results on
the vanishing of the reduced $\ell^p$-cohomology in degree one are obtained as
an intermediate step.


title:
Semi-classical quantization rules for a periodic orbit of hyperbolic
  type

abstract:
  Determination of periodic orbits for a Hamiltonian system together with their
semi-classical quantization has been a long standing problem. We consider here
resonances for a $h$-Pseudo-Differential Operator $H(y,hD_y;h)$ induced by a
periodic orbit of hyperbolic type at energy $E_0$. We generalize the framework
of [G\'eSj], in the sense that we allow for both hyperbolic and elliptic
eigenvalues of Poincar\'e map, and show that all resonances in
$W=[E_0-\varepsilon_0,E_0+\varepsilon_0]-i]0,h^\delta]$, $0<\delta<1$, are
given by a generalized Bohr-Sommerfeld quantization rule.


title: Decuplets, glueballs and nonet anomalies

abstract:
  A new approach to problem of glueball search is presented. It refers to early
J. Rosner's attempts to detect the tensor glueball. In the present description
the glueball state is treated on equal footing with singlet $q\bar{q}$ one.
Mixing glueball with $q\bar{q}$ nonet creates decuplet. Glueball can be
detected as its component. Our approach is based on hypothesis of vanishing
exotic commutators described as VEC model. The model describes all multiplets
of light mesons. This makes possible to compare the mass patterns of different
multiplets. According to VEC description some abnormal nonets can be
interpreted as incomplete decuplets. This makes possible to relate the anomaly
of the nonet to a glueball component of decuplet. The model reflects rich
diversity of strong interaction properties. The treatment presented is quite
elementary: only masses of physical states are required to be known.


title: High-energy gamma-rays from Cyg X-1

abstract:
  We have obtained a firm detection of Cyg X-1 during its hard and intermediate
spectral states in the energy range of 40 MeV--60 GeV based on observations by
the Fermi Large Area Telescope, confirming the independent results at
$\geq$60MeV of a previous work. The detection significance is $\simeq\!8\sigma$
in the 0.1--10 GeV range. In the soft state, we have found only upper limits on
the emission at energies $\gtrsim$0.1 MeV. However, we have found emission with
a very soft spectrum in the 40--80 MeV range, not detected previously. This is
likely to represent the high-energy cutoff of the high-energy power-law tail
observed in the soft state. Similarly, we have detected a $\gamma$-ray soft
excess in the hard state, which appears to be of similar origin. We have also
confirmed the presence of an orbital modulation of the detected emission in the
hard state, expected if the $\gamma$-rays are from Compton upscattering of
stellar blackbody photons. However, the observed modulation is significantly
weaker than that predicted if the blackbody upscattering were the dominant
source of $\gamma$-rays. This argues for a significant contribution from
$\gamma$-rays produced by the synchrotron-self-Compton process. We have found
that such strong contribution is possible if the jet is strongly clumped. We
reproduce the observed hard-state average broad-band spectrum using a
self-consistent jet model, taking into account all the relevant emission
processes, e$^\pm$ pair absorption, and clumping. This model also reproduces
the amplitude of the observed orbital modulation.


title:
Attempts to test an alternative electrodynamic theory of superconductors
  by low-temperature scanning tunneling and atomic force microscopy

abstract:
  We perform an experiment to test between two theories of the electrodynamics
of superconductors: the standard London theory and an alternative proposed by
J. E. Hirsch [Phys. Rev. B 69, 214515 (2004)]. The two alternatives give
different predictions with respect to the screening of an electric field by a
superconductor, and we try to detect this effect using atomic force microscopy
on a niobium sample. We also perform the reverse experiment, where we
demonstrate a superconductive tip mounted on a qPlus force sensor. Due to
limited accuracy, we are able neither to prove nor to disprove Hirsch's
hypothesis. Within our accuracy of 0.17 N/m, the superconductive transition
does not alter the atomic-scale interaction between tip and sample.


title: Minimal graphs over Riemannian surfaces and harmonic diffeomorphisms

abstract:
  We construct a parabolic entire minimal graph $S$ over a finite topology
complete Riemannian surface $\Sigma$ of curvature $-1$ and infinite area (thus
of non-parabolic conformal type). The vertical projection of this graph yields
a harmonic diffeomorphism from $S$ onto $\Sigma$. The proof uses the theory of
divergence lines to construct minimal graphs.
  We also generalize a theorem of R. Schoen. Let $g_1$ and $g_2$ be two
complete metrics on a orientable surface $S$ with compact boundary and suppose
$$\int_{S_r^2}K_{g_2}^-d\sigma_{g_2}\le C\ln(2+r)$$ for some $C>0$ and all
$r>0$. If there is a harmonic diffeomorphism from $(S,g_1)$ to $(S,g_2)$, then
$(S,g_1)$ is parabolic.


title: Fate of photon blockade in the deep strong coupling regime

abstract:
  We investigate the photon emission properties of the driven-dissipative Rabi
model in the so-called ultrastrong and deep strong coupling regimes, where the
atom-cavity coupling rate $g$ becomes comparable or larger than the cavity
frequency $\omega_c$. By solving numerically the master equation in the
dressed-state basis, we compute the output field correlation functions in the
steady-state for a wide range of coupling rates. We find that, as the
atom-cavity coupling strength increases, the system undergoes multiple
transitions in the photon statistics. In particular, a first sharp
anti-bunching to bunching transition, occurring at $g\sim0.45\omega_c$, leading
to the breakdown of the photon blockade due to the counter-rotating terms, is
shown to be the consequence of a parity shift in the energy spectrum. A
subsequent revival of the photon blockade and the emergence of the
quasi-coherent statistics, for even larger coupling rates, are attributed to an
interplay between the nonlinearity in the energy spectrum and the transition
rates between the dressed states.


title:
Collision of two general particles around a rotating regular Hayward's
  black holes

abstract:
  The rotating regular Hayward's spacetime, apart from mass ($M$) and angular
momentum ($a$), has an additional deviation parameter ($g$) due to the magnetic
charge, which generalizes the Kerr black hole when $g\neq0$, and for $g=0$, it
goes over to the Kerr black hole. We analyze how the ergoregion is affected by
the parameter $g$ to show that the area of ergoregion increases with increasing
values of $g$. Further, for each $g$, there exist critical $a_E$, which
corresponds to a regular extremal black hole with degenerate horizons
$r=r^E_H$, and $a_E$ decrease whereas $r^E_H$ increases with an increase in the
parameter $g$. Ban{\~a}dos, Silk and West (BSW) demonstrated that the extremal
Kerr black hole can act as a particle accelerator with arbitrarily high
center-of-mass energy ($E_{CM}$) when the collision of two particles takes
place near the horizon. We study the BSW process for two particles with
different rest masses, $m_1$ and $m_2$, moving in the equatorial plane of
extremal Hayward's black hole for different values of $g$, to show that
$E_{CM}$ of two colliding particles is arbitrarily high when one of the
particles takes a critical value of angular momentum. For a nonextremal case,
there always exist a finite upper bound for the $E_{CM}$, which increases with
the deviation parameter $g$. Our results, in the limit $g \rightarrow 0$,
reduces to that of the Kerr black hole.


title: Bounds on the Reliability of a Typewriter Channel

abstract:
  We give new bounds on the reliability function of a typewriter channel with 5
inputs and crossover probability $1/2$. The lower bound is more of theoretical
than practical importance; it improves very marginally the expurgated bound,
providing a counterexample to a conjecture on its tightness by Shannon,
Gallager and Berlekamp which does not need the construction of
algebraic-geometric codes previously used by Katsman, Tsfasman and
Vl\u{a}du\c{t}. The upper bound is derived by using an adaptation of the linear
programming bound and it is essentially useful as a low-rate anchor for the
straight line bound.


title: Processing In-memory realization using Quantum Dot Cellular Automata

abstract:
  The present manuscript deals with the realization of Processing In-memory
(PIM) computing architecture using Quantum Dot Cellular Automata (QCA) and
Akers array. The PIM computing architecture becomes popular due to its
effective framework for storage and computation of data in a single unit. Here,
we illustrate two input NAND and NOR gate with the help of QCA based Akers
Array as a case study. The QCA flip-flop is used as a primitive cell to design
PIM architecture. The results suggested that both the gate have minimum power
dissipation. The polarization results of proposed architecture suggested that
the signals are in good control. The foot print of the primitive cell equals to
0.04 micron^2, which is smaller than conventional CMOS primitive cell. The
combination of QCA and Akers array provides many additional benefits over the
conventional architecture like reduction in the power consumption and feature
size, furthermore, it also improves the computational speed.


title: Recycle deep features for better object detection

abstract:
  Aiming at improving the performance of existing detection algorithms
developed for different applications, we propose a region regression-based
multi-stage class-agnostic detection pipeline, whereby the existing algorithms
are employed for providing the initial detection proposals. Better detection is
obtained by exploiting the power of deep learning in the region regress scheme
while avoiding the requirement on a huge amount of reference data for training
deep neural networks. Additionally, a novel network architecture with recycled
deep features is proposed, which provides superior regression results compared
to the commonly used architectures. As demonstrated on a data set with ~1200
samples of different classes, it is feasible to successfully train a deep
neural network in our proposed architecture and use it to obtain the desired
detection performance. Since only slight modifications are required to common
network architectures and since the deep neural network is trained using the
standard hyperparameters, the proposed detection is well accessible and can be
easily adopted to a broad variety of detection tasks.


title:
On Coefficient Estimates of Negative Powers and Inverse Coefficients for
  Certain Starlike Functions

abstract:
  For $-1\le B<A\le 1$, let $\mathcal{S}^*(A,B)$ denote the class of normalized
analytic functions $f(z)= z+\sum_{n=2}^{\infty}a_n z^n$ in $|z|<1$ which
satisfy the subordination relation $zf'(z)/f(z)\prec (1+Az)/(1+Bz)$ and
$\Sigma^*(A,B)$ be the corresponding class of meromorphic functions in $|z|>1$.
For $f\in\mathcal{S}^*(A,B)$ and $\lambda>0$, we shall estimate the absolute
value of the Taylor coefficients $a_n(-\lambda,f)$ of the analytic function
$(f(z)/z)^{-\lambda}$. Using this we shall determine the coefficient estimate
for inverses of functions in the classes $\mathcal{S}^*(A,B)$ and
$\Sigma^*(A,B)$.


title:
Numerical modelling of shaking effects due to strong motions on the
  tiber alluvial deposits in Rome (Italy)

abstract:
  A multidisciplinary approach is proposed for evaluating the effects of
shaking due to strong motions on the Tiber river alluvial deposits in Rome's
historical centre. At this aim, a detailed 3D geological model of the Tiber
river alluvial deposit has been constructed and a numerical analysis of site
response was performed along two geological sections across the historical
centre of Rome. The numerical models were performed in both 1D and 2D
configurations assuming linear and nonlinear conditions, by applying a three
component seismic input. The results show that the maximum shear strains are
strongly conditioned by the layer geometries (i.e. 2D or 1D conditions) and by
the soil heterogeneity. Moreover, the reliability of the maximum strains
obtained by numerical modeling is discussed comparing these values respect to
both the volumetric and the degradation dynamic thresholds of the considered
soils.


title:
Algorithmic Trading: A brief, computational finance case study on data
  centre FPGAs

abstract:
  Increasingly FPGAs will be deployed at scale due to the need for increased
need for power efficient computation and improved high level synthesis tool
flows, creating a new category of device: data centre FPGAs. A method for using
these FPGAs is to identify what proportion of a given workload would benefit
from being implemented upon the available FPGAs while minimising communication
off-chip. As part of the implementation of these tasks, care should be taken in
identifying the parallel execution mode, task or pipeline parallelism that
should be used. When considering a case study of computational finance tasks, a
benchmark workload of Heston and Black-Scholes-based options implemented using
OpenCL and OpenSPL, the benefit of this method of using data centre FPGAs is
illustrated. These devices deliver latency performance close to that of
workstation grade GPUs, while requiring considerably less energy, resulting in
30% more floating point operations per Joule of energy consumed.


title: Multi-region relaxed Hall magnetohydrodynamics with flow

abstract:
  The recent formulations of multi-region relaxed magnetohydrodynamics (MRxMHD)
have generalized the famous Woltjer-Taylor states by incorporating a collection
of "ideal barriers" that prevent global relaxation, and flow. In this paper, we
generalize MRxMHD with flow to include Hall effects (MRxHMHD), and thereby
obtain the partially relaxed counterparts of the famous double Beltrami states
as a special subset. The physical and mathematical consequences arising from
the introduction of the Hall term are also presented. We demonstrate that our
results (in the ideal MHD limit) constitute an important subset of ideal MHD
equilibria, and we compare our approach against other variational principles
proposed for deriving the partially relaxed states.


title:
Laser agitates probability flow in atoms to form alternating current and
  its peak-dip phenomenon

abstract:
  By using trajectory-based approaches to quantum transition, it is found that
laser can agitate the probability flow in atoms to form alternating current
with the frequency of the laser. The detailed physical process of quantum
transition is investigated, during which the alternating current in atomic
probability flow becomes a key role connecting the external electromagnetic
wave with the evolution of the quantum states in atoms. Computer was employed
to simulate the physical process. The atomic alternating current may have the
peak-dip phenomenon.


title:
Density diagnostics derived from the OIV and SIV intercombination lines
  observed by IRIS

abstract:
  The intensity of the \oiv~2s$^{2}$ 2p $^{2}$P-2s2p$^{2}$ $^{4}$P and \siv~3
s$^{2}$ 3p $^{2}$P- 3s 3p$^{2}$ $^{4}$ P intercombination lines around
1400~\AA~observed with the \textit{Interface Region Imaging Spectrograph}
(IRIS) provide a useful tool to diagnose the electron number density
($N_\textrm{e}$) in the solar transition region plasma. We measure the electron
number density in a variety of solar features observed by IRIS, including an
active region (AR) loop, plage and brightening, and the ribbon of the
22-June-2015 M 6.5 class flare. By using the emissivity ratios of \oiv\ and
\siv\ lines, we find that our observations are consistent with the emitting
plasma being near isothermal (log$T$[K] $\approx$ 5) and iso-density
($N_\textrm{e}$ $\approx$~10$^{10.6}$ cm$^{-3}$) in the AR loop. Moreover, high
electron number densities ($N_\textrm{e}$ $\approx$~10$^{13}$ cm$^{-3}$) are
obtained during the impulsive phase of the flare by using the \siv\ line ratio.
We note that the \siv\ lines provide a higher range of density sensitivity than
the \oiv\ lines. Finally, we investigate the effects of high densities
($N_\textrm{e}$ $\gtrsim$ 10$^{11}$ cm$^{-3}$) on the ionization balance. In
particular, the fractional ion abundances are found to be shifted towards lower
temperatures for high densities compared to the low density case. We also
explored the effects of a non-Maxwellian electron distribution on our
diagnostic method.


title: Higher-Order Block Term Decomposition for Spatially Folded fMRI Data

abstract:
  The growing use of neuroimaging technologies generates a massive amount of
biomedical data that exhibit high dimensionality. Tensor-based analysis of
brain imaging data has been proved quite effective in exploiting their multiway
nature. The advantages of tensorial methods over matrix-based approaches have
also been demonstrated in the characterization of functional magnetic resonance
imaging (fMRI) data, where the spatial (voxel) dimensions are commonly grouped
(unfolded) as a single way/mode of the 3-rd order array, the other two ways
corresponding to time and subjects. However, such methods are known to be
ineffective in more demanding scenarios, such as the ones with strong noise
and/or significant overlapping of activated regions. This paper aims at
investigating the possible gains from a better exploitation of the spatial
dimension, through a higher- (4 or 5) order tensor modeling of the fMRI signal.
In this context, and in order to increase the degrees of freedom of the
modeling process, a higher-order Block Term Decomposition (BTD) is applied, for
the first time in fMRI analysis. Its effectiveness is demonstrated via
extensive simulation results.


title: Deep Active Contours

abstract:
  We propose a method for interactive boundary extraction which combines a
deep, patch-based representation with an active contour framework. We train a
class-specific convolutional neural network which predicts a vector pointing
from the respective point on the evolving contour towards the closest point on
the boundary of the object of interest. These predictions form a vector field
which is then used for evolving the contour by the Sobolev active contour
framework proposed by Sundaramoorthi et al. The resulting interactive
segmentation method is very efficient in terms of required computational
resources and can even be trained on comparatively small graphics cards. We
evaluate the potential of the proposed method on both medical and non-medical
challenge data sets, such as the STACOM data set and the PASCAL VOC 2012 data
set.


title:
Functional Augmented State Transfer (FAST) Architecture for
  Computationally Intensive Network Applications

abstract:
  We describe a novel architecture that combines the simplicity of RESTful
architecture with the power of functional programming for delivering
web-services. Although, RESTful architecture has been quite useful in
simplifying the development of scalable systems, it is not suited for all types
of network applications. Our architecture improves upon the RESTful
architecture to provide scalable framework for computationally intensive
network applications. The proposed architecture is ideal for applications that
involve data management and data analysis/calculations on data. Data analytics
and financial calculations are two areas where the architecture can be applied
efficiently.


title:
Analysis of chromatic dispersion compensation and carrier phase recovery
  in long-haul optical transmission system influenced by equalization enhanced
  phase noise

abstract:
  The performance of long-haul coherent optical fiber transmission system is
significantly affected by the equalization enhanced phase noise (EEPN), due to
the interaction between the electronic dispersion compensation (EDC) and the
laser phase noise. In this paper, we present a comprehensive study on different
chromatic dispersion (CD) compensation and carrier phase recovery (CPR)
approaches, in the n-level phase shift keying (n-PSK) and the n-level
quadrature amplitude modulation (n-QAM) coherent optical transmission systems,
considering the impacts of EEPN. Four CD compensation methods are considered:
the time-domain equalization (TDE), the frequency-domain equalization (FDE),
the least mean square (LMS) adaptive equalization are applied for EDC, and the
dispersion compensating fiber (DCF) is employed for optical dispersion
compensation (ODC). Meanwhile, three carrier phase recovery methods are also
involved: a one-tap normalized least mean square (NLMS) algorithm, a block-wise
average (BWA) algorithm, and a Viterbi-Viterbi (VV) algorithm. Numerical
simulations have been carried out in a 28-Gbaud dual-polarization quadrature
phase shift keying (DP-QPSK) coherent transmission system, and the results
indicate that the origin of EEPN depends on the choice of chromatic dispersion
compensation methods, and the effects of EEPN also behave moderately different
in accordance to different carrier phase recovery scenarios.


title:
Playing Atari Games with Deep Reinforcement Learning and Human
  Checkpoint Replay

abstract:
  This paper introduces a novel method for learning how to play the most
difficult Atari 2600 games from the Arcade Learning Environment using deep
reinforcement learning. The proposed method, human checkpoint replay, consists
in using checkpoints sampled from human gameplay as starting points for the
learning process. This is meant to compensate for the difficulties of current
exploration strategies, such as epsilon-greedy, to find successful control
policies in games with sparse rewards. Like other deep reinforcement learning
architectures, our model uses a convolutional neural network that receives only
raw pixel inputs to estimate the state value function. We tested our method on
Montezuma's Revenge and Private Eye, two of the most challenging games from the
Atari platform. The results we obtained show a substantial improvement compared
to previous learning approaches, as well as over a random player. We also
propose a method for training deep reinforcement learning agents using human
gameplay experience, which we call human experience replay.


title: Comparing Different Mathematical Definitions of 2D CFT

abstract:
  We give introductions into the representation theory of the Virasoro algebra,
Wightman axioms and vertex algebras in the first part.
  In the second part, we compare the above definitions. We give a proof of
Luescher and Mack that a dilation invariant 2D QFT with an energy-momentum
tensor gives rise to two commuting unitary representations of the Virasoro
algebra.
  In the last chapter we compare Wightman QFTs to vertex algebras. We present
Kac's proof that every Wightman Moebius CFT (a 2D Wightman QFT containing
quasiprimary fields) gives rise to two commuting strongly-generated
positive-energy Moebius conformal vertex algebras. If the number of generating
fields of each conformal weight is finite, then these vertex algebras are
unitary quasi-vertex operator algebras. As a corollary using Luescher--Mack's
Theorem we obtain that a Wightman CFT (a Wightman Moebius CFT with an
energy-momentum tensor) gives rise to a conformal vertex algebra which
furthermore becomes a unitary vertex operator algebra, if the number of
generating fields of each conformal weight is finite. We reverse Kac's
arguments and get a converse proof that two unitary (quasi)-vertex operator
algebras can be combined to give a Wightman (Moebius) CFT.


title:
Skeletal mechanism generation for surrogate fuels using directed
  relation graph with error propagation and sensitivity analysis

abstract:
  A novel implementation for the skeletal reduction of large detailed reaction
mechanisms using the directed relation graph with error propagation and
sensitivity analysis (DRGEPSA) is developed and presented with examples for
three hydrocarbon components, n-heptane, iso-octane, and n-decane, relevant to
surrogate fuel development. DRGEPSA integrates two previously developed
methods, directed relation graph-aided sensitivity analysis (DRGASA) and
directed relation graph with error propagation (DRGEP), by first applying DRGEP
to efficiently remove many unimportant species prior to sensitivity analysis to
further remove unimportant species, producing an optimally small skeletal
mechanism for a given error limit. It is illustrated that the combination of
the DRGEP and DRGASA methods allows the DRGEPSA approach to overcome the
weaknesses of each, specifically that DRGEP cannot identify all unimportant
species and that DRGASA shields unimportant species from removal. Skeletal
mechanisms for n-heptane and iso-octane generated using the DRGEP, DRGASA, and
DRGEPSA methods are presented and compared to illustrate the improvement of
DRGEPSA. From a detailed reaction mechanism for n-alkanes covering n-octane to
n-hexadecane with 2115 species and 8157 reactions, two skeletal mechanisms for
n-decane generated using DRGEPSA, one covering a comprehensive range of
temperature, pressure, and equivalence ratio conditions for autoignition and
the other limited to high temperatures, are presented and validated. The
comprehensive skeletal mechanism consists of 202 species and 846 reactions and
the high-temperature skeletal mechanism consists of 51 species and 256
reactions. Both mechanisms are further demonstrated to well reproduce the
results of the detailed mechanism in perfectly-stirred reactor and laminar
flame simulations over a wide range of conditions.


title:
`Zwicky's Nonet': a compact merging ensemble of nine galaxies and 4C
  35.06, a peculiar radio galaxy with dancing radio jets

abstract:
  We report the results of our radio, optical and infra-red studies of a
peculiar radio source 4C~35.06, an extended radio-loud AGN at the center of
galaxy cluster Abell 407 ($z=0.047$). The central region of this cluster hosts
a remarkably tight ensemble of nine galaxies, the spectra of which resemble
those of passive red ellipticals, embedded within a diffuse stellar halo of
$\sim$1~arcmin size. This system (named the `Zwicky's Nonet') provides unique
and compelling evidence for a multiple-nucleus cD galaxy precursor.
Multifrequency radio observations of 4C~35.06 with the Giant Meterwave Radio
Telescope (GMRT) at 610, 235 and 150 MHz reveal a system of 400~kpc scale
helically twisted and kinked radio jets and outer diffuse lobes. The outer
extremities of jets contain extremely steep spectrum (spectral index -1.7 to
-2.5) relic/fossil radio plasma with a spectral age of a few$\,\times (10^7 -
10^8)$ yr. Such ultra-steep spectrum relic radio lobes without definitive
hot-spots are rare, and they provide an opportunity to understand the
life-cycle of relativistic jets and physics of black hole mergers in dense
environments. We interpret our observations of this radio source in the context
of the growth of its central black hole, triggering of its AGN activity and jet
precession, all possibly caused by galaxy mergers in this dense galactic
system. A slow conical precession of the jet axis due to gravitational
perturbation between interacting black holes is invoked to explain the unusual
jet morphology.


title:
Nonlinear differential algorithm to compute all the zeros of a generic
  polynomial

abstract:
  A simple algorithm to compute all the zeros of a generic polynomial is
proposed.


title: Finite Temperature Lattice QCD - Baryons in the Quark-Gluon Plasma

abstract:
  Baryonic correlation functions provide an ideal tool to study parity doubling
and chiral symmetry using lattice simulations. We present a study using $2+1$
flavors of anisotropic Wilson clover fermions on the FASTSUM ensembles and find
clear evidence that parity doubling emerges in the quark-gluon plasma. This
result is confirmed on the level of spectral functions, which are obtained
using a MEM reconstruction. We further highlight the importance of Gaussian
smearing in this study.


title:
Embedded trilayer graphene flakes under efficient tensile and
  compressive loading

abstract:
  The mechanical response of embedded ABA trilayer graphene flakes loaded in
tension and compression on polymer beams is monitored by simultaneous Raman
measurements through the strain sensitivity of the G or 2D peaks. A
characteristic peculiarity of the investigated flake is that it contains a
trilayer and bilayer part. The Bernal stacked bilayer was used as a strain
sensor aiming to assess the efficiency of the load transfer from the polymer
matrix through shear to the individual graphene layers. For the trilayer
graphene in tension, both peaks are redshifted and splitting of the G peak is
reported for the first time. In compression, the studied sample was an almost
isolated trilayer, in which both peaks are blue-shifted up to a critical
compressive strain. This critical strain is found to be one fourth of the value
found in the case of single layer graphene despite the higher bending rigidity
that trilayer exhibits over the much thinner monolayer.


title:
Determination of the muonic branching ratio of the W boson and its total
  width via cross-section measurements at the Tevatron and LHC

abstract:
  The total $W$-boson decay width $\Gamma_W$ is an important observable which
allows testing of the standard model. The current world average value is based
on direct measurements of final state kinematic properties of $W$-boson decays,
and has a relative uncertainty of 2%. The indirect determination of $\Gamma_W$
via the cross-section measurements of vector-boson production can lead to a
similar accuracy. The same methodology leads also to a determination of the
leptonic branching ratio. This approach has been successfully pursued by the
CDF and D0 experiments at the Tevatron collider, as well as by the CMS
collaboration at the LHC. In this paper we present for the first time a
combination of the available measurements at hadron colliders, accounting for
the correlations of the associated systematic uncertainties. Our combination
leads to values of $\textrm{BR}(W\rightarrow\mu\nu)=(10.72 \pm 0.16)\%$ and
$\Gamma_W = 2113 \pm 31$ MeV, respectively, both compatible with the current
world averages.


title: Predictive Index for slope instabilities in open pit mining

abstract:
  In this paper we study the stability and deformation of structures, in
particular the wall of an open pit mine is studied by using information
obtained from a variety of remote sensors and some extra data, with a novelty
approach considering the use of mathematical models and data mining techniques.
In particular we present two models to help the study the slope stability of
pit and the possible occurrence of movements. Primarily we present an static
model for slow movements, which will help us identify areas of possible risks
areas with time horizons of several months or years, depends on the available
information, before the wall start moving, and secondly a dynamic short-term
model, which help us to determine risks of collapse zones with several days in
advance. We remark that this methodology can be a powerful tool to plain future
actions in order to simulate possible scenarios considering the production
plans.


title: Association schemes and Hypergroups

abstract:
  In this paper, we investigate hypergroups which arise from association
schemes in a canonical way; this class of hypergroups is called realizable. We
first study basic algebraic properties of realizable hypergroups. Then we prove
that two interesting classes of hypergroups (partition hypergroups and linearly
ordered hypergroups) are realizable. Along the way, we prove that a certain
class of projective geometries is equipped with a canonical association scheme
structure which allows us to link three objects; association schemes,
hypergroups, and projective geometries.