title: Structural analysis of the Sextans dwarf spheroidal galaxy

abstract:
  We present wide-field $g$ and $i$ band stellar photometry of the Sextans
dwarf spheroidal galaxy and its surrounding area out to four times its
half-light radius ($r_h=695\,$pc), based on images obtained with the Dark
Energy Camera at the 4-m Blanco telescope at CTIO. We find clear evidence of
stellar substructure associated with the galaxy, extending to a distance of
$82\arcmin$ (2\,kpc) from its centre. We perform a statistical analysis of the
over-densities and find three distinct features, as well as an extended
halo-like structure, to be significant at the $99.7\%$ confidence level or
higher. Unlike the extremely elongated and extended substructures surrounding
the Hercules dwarf spheroidal galaxy, the over-densities seen around Sextans
are distributed evenly about its centre, and do not appear to form noticeable
tidal tails. Fitting a King model to the radial distribution of Sextans stars
yields a tidal radius $r_t =83.2\arcmin\pm7.1\arcmin$ (2.08$\pm$0.18\,kpc),
which implies the majority of detected substructure is gravitationally bound to
the galaxy. This finding suggests that Sextans is not undergoing significant
tidal disruption from the Milky Way, supporting the scenario in which the orbit
of Sextans has a low eccentricity.


title: Ultrafast coherent dynamics of a photonic crystal all-optical switch

abstract:
  We present pump-probe measurements of an all-optical photonic crystal switch
based on a nanocavity, resolving fast coherent temporal dynamics. The
measurements demonstrate the importance of coherent effects typically neglected
when considering nanocavity dynamics. In particular, we report the observation
of an idler pulse. The measurements are in good agreement with a theoretical
model that allows us to ascribe the observation to oscillations of the free
carrier population in the nanocavity. The effect opens perspectives for the
realization of new all-optical photonic crystal switches with unprecedented
switching contrast.


title: On the Relativistic anisotropic configurations

abstract:
  In this paper we study anisotropic spherical polytropes within the framework
of general relativity. Using the anisotropic Tolman-Oppenheimer-Volkov (TOV)
equations, we explore the relativistic anisotropic Lane-Emden equations. We
find how the anisotropic pressure affects the boundary conditions of these
equations. Also we argue that the behaviour of physical quantities near the
center of star changes in the presence of anisotropy. For constant density, a
class of exact solution is derived with the aid of a new ansatz and its
physical properties are discussed.


title: Single electron relativistic clock interferometer

abstract:
  Although time is one of the fundamental notions in physics, it does not have
a unique description. In quantum theory time is a parameter ordering the
succession of the probability amplitudes of a quantum system, while according
to relativity theory each system experiences in general a different proper
time, depending on the system's world line, due to time to time dilation. It is
therefore of fundamental interest to test the notion of time in the regime
where both quantum and relativistic effects play a role, for example, when
different amplitudes of a single quantum clock experience different magnitudes
of time dilation. Here we propose a realization of such an experiment with a
single electron in a Penning trap. The clock can be implemented in the
electronic spin precession and its time dilation then depends on the radial
(cyclotron) state of the electron. We show that coherent manipulation and
detection of the electron can be achieved already with present day technology.
A single electron in a Penning trap is a technologically ready platform where
the notion of time can be probed in a hitherto untested regime, where it
requires a relativistic as well as quantum description.


title:
Supermassive Black Holes with High Accretion Rates in Active Galactic
  Nuclei. V. A New Size-Luminosity Scaling Relation for the Broad-Line Region

abstract:
  This paper reports results of the third-year campaign of monitoring
super-Eddington accreting massive black holes (SEAMBHs) in active galactic
nuclei (AGNs) between 2014-2015. Ten new targets were selected from quasar
sample of Sloan Digital Sky Survey (SDSS), which are generally more luminous
than the SEAMBH candidates in last two years. H$\beta$ lags ($\tau_{_{\rm
H\beta}}$) in five of the 10 quasars have been successfully measured in this
monitoring season. We find that the lags are generally shorter, by large
factors, than those of objects with same optical luminosity, in light of the
well-known $R_{_{\rm H\beta}}-L_{5100}$ relation. The five quasars have
dimensionless accretion rates of $\dot{\mathscr{M}}=10-10^3$. Combining
measurements of the previous SEAMBHs, we find that the reduction of H$\beta$
lags tightly depends on accretion rates, $\tau_{_{\rm
H\beta}}/\tau_{_{R-L}}\propto\dot{\mathscr{M}}^{-0.42}$, where $\tau_{_{R-L}}$
is the H$\beta$ lag from the normal $R_{_{\rm H\beta}}-L_{5100}$ relation.
Fitting 63 mapped AGNs, we present a new scaling relation for the broad-line
region: $R_{_{\rm
H\beta}}=\alpha_1\ell_{44}^{\beta_1}\,\min\left[1,\left(\dot{\mathscr{M}}/\dot{\mathscr{M}}_c\right)^{-\gamma_1}\right]$,
where $\ell_{44}=L_{5100}/10^{44}\,\rm erg~s^{-1}$ is 5100 \AA\ continuum
luminosity, and coefficients of $\alpha_1=(29.6_{-2.8}^{+2.7})$ lt-d,
$\beta_1=0.56_{-0.03}^{+0.03}$, $\gamma_1=0.52_{-0.16}^{+0.33}$ and
$\dot{\mathscr{M}}_c=11.19_{-6.22}^{+2.29}$. This relation is applicable to
AGNs over a wide range of accretion rates, from $10^{-3}$ to $10^3$.
Implications of this new relation are briefly discussed.


title:
Supports of Invariant Measures for Piecewise Deterministic Markov
  Processes

abstract:
  For a class of piecewise deterministic Markov processes, the supports of the
invariant measures are characterized. This is based on the analysis of
controllability properties of an associated deterministic control system. Its
invariant control sets determine the supports.


title:
Sharp Tunneling Resonance from the Vibrations of an Electronic Wigner
  Crystal

abstract:
  Photoemission and tunneling spectroscopies measure the energies at which
single electrons can be added to or removed from an electronic system. Features
observed in such spectra have revealed electrons coupling to vibrational modes
of ions both in solids and in individual molecules. Here we report the
discovery of a sharp resonance in the tunneling spectrum of a 2D electron
system. Its behavior suggests that it originates from vibrational modes, not
involving ionic motion, but instead arising from vibrations of spatial ordering
of the electrons themselves. In a two-dimensional electronic system at very low
temperatures and high magnetic fields, electrons can either condense into a
variety of quantum Hall phases or arrange themselves into a highly ordered
Wigner crystal lattice. Such spatially ordered phases of electrons are often
electrically insulating and delicate and have proven very challenging to probe
with conventional methods. Using a unique pulsed tunneling method capable of
probing electron tunneling into insulating phases, we observe a sharp peak with
dependencies on energy and other parameters that fit to models for vibrations
of a Wigner crystal. The remarkable sharpness of the structure presents strong
evidence of the existence of a Wigner crystal with long correlation length.


title:
Detection and Combining Techniques for Asynchronous Random Access with
  Time Diversity

abstract:
  Asynchronous random access (RA) protocols are particularly attractive for
their simplicity and avoidance of tight synchronization requirements. Recent
enhancements have shown that the use of successive interference cancellation
(SIC) can largely boost the performance of these schemes. A further step
forward in the performance can be attained when diversity combining techniques
are applied. In order to enable combining, the detection and association of the
packets to their transmitters has to be done prior to decoding. We present a
solution to this problem, that articulates into two phases. Non-coherent
soft-correlation as well as interference-aware soft-correlation are used for
packet detection. We evaluate the detection capabilities of both solutions via
numerical simulations. We also evaluate numerically the spectral efficiency
achieved by the proposed approach, highlighting its benefits.


title:
Transition from sign-reversed to sign-preserved Cooper-pairing symmetry
  in sulfur-doped iron selenide superconductors

abstract:
  An essential step toward elucidating the mechanism of superconductivity is to
determine the sign/phase of superconducting order parameter, as it is closely
related to the pairing interaction. In conventional superconductors, the
electron-phonon interaction induces attraction between electrons near the Fermi
energy and results in a sign-preserved s-wave pairing. For high-temperature
superconductors, including cuprates and iron-based superconductors, prevalent
weak coupling theories suggest that the electron pairing is mediated by spin
fluctuations which lead to repulsive interactions, and therefore that a
sign-reversed pairing with an s+-or d-wave symmetry is favored. Here, by using
magnetic neutron scattering, a phase sensitive probe of superconducting gap, we
report the observation of a transition from the sign-reversed to sign-preserved
Cooper-pairing symmetry with insignificant changes in Tc in the S-doped iron
selenide superconductors KxFe2-y(Se1-zSz)2. We show that a rather sharp
magnetic resonant mode well below the superconducting gap (2delta) in the
undoped sample (z = 0) is replaced by a broad hump structure above 2delta under
50% S doping. These results cannot be readily explained by simple spin
fluctuation-exchange pairing theories and, therefore, multiple pairing channels
are required to describe superconductivity in this system. Our findings may
also yield a simple explanation for the sometimes contradictory data on the
sign of the superconducting order parameter in iron-based materials.


title: Task scheduling system for UAV operations in indoor environment

abstract:
  Application of UAV in indoor environment is emerging nowadays due to the
advancements in technology. UAV brings more space-flexibility in an occupied or
hardly-accessible indoor environment, e.g., shop floor of manufacturing
industry, greenhouse, nuclear powerplant. UAV helps in creating an autonomous
manufacturing system by executing tasks with less human intervention in
time-efficient manner. Consequently, a scheduler is one essential component to
be focused on; yet the number of reported studies on UAV scheduling has been
minimal. This work proposes a methodology with a heuristic (based on Earliest
Available Time algorithm) which assigns tasks to UAVs with an objective of
minimizing the makespan. In addition, a quick response towards uncertain events
and a quick creation of new high-quality feasible schedule are needed. Hence,
the proposed heuristic is incorporated with Particle Swarm Optimization (PSO)
algorithm to find a quick near optimal schedule. This proposed methodology is
implemented into a scheduler and tested on a few scales of datasets generated
based on a real flight demonstration. Performance evaluation of scheduler is
discussed in detail and the best solution obtained from a selected set of
parameters is reported.


title: Discrete Variational Derivative Methods for the EPDiff equation

abstract:
  The aim of this paper is the derivation of structure preserving schemes for
the solution of the EPDiff equation, with particular emphasis on the two
dimensional case. We develop three different schemes based on the Discrete
Variational Derivative Method (DVDM) on a rectangular domain discretized with a
regular, structured, orthogonal grid.
  We present numerical experiments to support our claims: we investigate the
preservation of energy and linear momenta, the reversibility, and the empirical
convergence of the schemes. The quality of our schemes is finally tested by
simulating the interaction of singular wave fronts.


title:
OCR Error Correction Using Character Correction and Feature-Based Word
  Classification

abstract:
  This paper explores the use of a learned classifier for post-OCR text
correction. Experiments with the Arabic language show that this approach, which
integrates a weighted confusion matrix and a shallow language model, improves
the vast majority of segmentation and recognition errors, the most frequent
types of error on our dataset.


title:
The monodromy representations of local systems associated with
  Lauricella's $F_D$

abstract:
  We give the monodromy representations of local systems of twisted homology
groups associated with Lauricella's system $F_D(a,b,c)$ of hypergeometric
differential equations under mild conditions on parameters. Our representation
is effective even in some cases when the system $F_D(a,b,c)$ is reducible. We
characterize invariant subspaces under our monodromy representations by the
kernel or image of a natural map from a finite twisted homology group to
locally finite one.


title:
Kinetics of Vapor-Solid Phase Transitions: Structure, growth and
  mechanism

abstract:
  Kinetics of separation between the low and high density phases in a single
component Lennard-Jones model has been studied via molecular dynamics
simulations, at a very low temperature, in the space dimension $d=2$. For
densities close to the vapor (low density) branch of the coexistence curve,
disconnected clusters of the high density phase exhibit ballistic motion, the
kinetic energy distribution of the clusters being closely Maxwellian. Starting
from nearly circular shapes, at the time of nucleation, these clusters grow via
sticky collisions, gaining filament-like nonequilibrium structure at late
times, with a very low fractal dimensionality. The origin of the latter is
shown to lie in the low mobility of the constituent particles, in the
corresponding cluster reference frame, due to the (quasi-long-range)
crystalline order. Standard self-similarity in the domain pattern, typically
observed in kinetics of phase transitions, is found to be absent in this growth
process. This invalidates the common method, that provides a growth law same as
in immiscible solid mixtures, of quantifying growth. An appropriate alternative
approach, involving the fractality in the structure, quantifies the growth of
the characteristic "length" to be a power-law with time, the exponent being
surprisingly high. The observed growth law has been derived via a
nonequilibrium kinetic theory.


title: A note on homogeneous ideals of polarized abelian surfaces

abstract:
  Gross and Popescu conjectured that the homogeneous ideal of an embedded
$(1,d)$-polarized abelian surface is generated by quadrics and cubics for
$d\geq 9$. We prove this using the projective normality of the embedding. It
follows that the homogeneous ideal of an abelian surface embedded by a complete
linear system is generated by quadrics and cubics, with three exceptions.


title:
Application of optimal data-based binning method to spatial analysis of
  ecological datasets

abstract:
  Investigation of highly structured data sets to unveil statistical
regularities is of major importance in complex system research. The first step
is to choose the scale at which to observe the process, the most informative
scale being the one that includes the important features while disregarding
noisy details in the data. In the investigation of spatial patterns, the
optimal scale defines the optimal bin size of the histogram in which to
visualize the empirical density of the pattern. In this paper we investigate a
method proposed recently by K.~H.~Knuth to find the optimal bin size of an
histogram as a tool for statistical analysis of spatial point processes. We
test it through numerical simulations on various spatial processes which are of
interest in ecology. We show that Knuth optimal bin size rule reducing noisy
fluctuations performs better than standard kernel methods to infer the
intensity of the underlying process. Moreover it can be used to highlight
relevant spatial characteristics of the underlying distribution such as space
anisotropy and clusterization. We apply these findings to analyse cluster-like
structures in plants' arrangement of Barro Colorado Island rainforest.


title: Galaxies in the Early Universe characterized in absorption and emission

abstract:
  Understanding how galaxies evolved from the early Universe through cosmic
time is a fundamental part of modern astrophysics. In order to study this
evolution it is important to sample the galaxies at various times in a
consistent way through time. In regular luminosity selected samples, our
analyses are biased towards the brightest galaxies at all times (as these are
easier to observe and identify). A complementary method relies on the
absorption imprint from neutral gas in galaxies, the so-called damped Ly-alpha
absorbers (DLAs) seen towards distant bright objects. This thesis seeks to
understand how the absorption selected galaxies relate to the emission selected
galaxies by identifying the faint glow from the absorbing galaxies at redshift
z~2.
  In the last Chapter, a study of the more evolved, massive galaxies is
presented. These galaxies are observed to be a factor of 2 to 6 times smaller
than local galaxies of similar masses. A new spectroscopically selected sample
is presented and the increased precision of the redshifts allows a more
detailed measurement of the scatter in the mass-size relation. The size
evolution of massive, quiescent galaxies is modelled by a `dilution' scenario,
in which progressively larger galaxies at later times are added to the
population of denser galaxies, causing an increase of the mean size of the
population. This model describes the evolution of both sizes and number
densities very well, however, the scatter in the model increases with time,
contrary to the data. It is thus concluded that a combination of `dilution' and
individual growth, e.g., through mergers, is needed.
  For brevity, the individual chapters based on published peer-reviewed
articles are omitted and a link to the given article is given instead.
  Principal supervisor: Johan P. U. Fynbo


title:
Evidence for creation of strong electromagnetic fields in relativistic
  heavy-ion collisions

abstract:
  It is proposed to identify a strong electric field created during
relativistic collisions of asymmetric nuclei via observation of pseudorapidity
and transverse momentum distributions of hadrons with the same mass but
opposite charges. The detailed calculation results for the directed flow within
the Parton-Hadron String Dynamics model are given for Cu-Au interactions at the
NICA collision energies of $\sqrt{s_{NN}}=9$ and $5$ GeV. The separation effect
is observable at 9 GeV as clearly as at 200 GeV


title:
Incremental Reconstruction of Urban Environments by Edge-Points Delaunay
  Triangulation

abstract:
  Urban reconstruction from a video captured by a surveying vehicle constitutes
a core module of automated mapping. When computational power represents a
limited resource and, a detailed map is not the primary goal, the
reconstruction can be performed incrementally, from a monocular video, carving
a 3D Delaunay triangulation of sparse points; this allows online incremental
mapping for tasks such as traversability analysis or obstacle avoidance. To
exploit the sharp edges of urban landscape, we propose to use a Delaunay
triangulation of Edge-Points, which are the 3D points corresponding to image
edges. These points constrain the edges of the 3D Delaunay triangulation to
real-world edges. Besides the use of the Edge-Points, a second contribution of
this paper is the Inverse Cone Heuristic that preemptively avoids the creation
of artifacts in the reconstructed manifold surface. We force the reconstruction
of a manifold surface since it makes it possible to apply computer graphics or
photometric refinement algorithms to the output mesh. We evaluated our approach
on four real sequences of the public available KITTI dataset by comparing the
incremental reconstruction against Velodyne measurements.


title:
Interaction of two magnetic resonance modes in polar phase of superfluid
  3He

abstract:
  We report results of low frequency nuclear magnetic resonance (NMR)
experiments in the superfluid polar phase of 3He which is stabilized by a new
type of "nematic" aerogel - nafen. We have found that an interaction between
transverse and longitudinal NMR modes may essentially influence the spin
dynamics. Theoretical formulas for NMR resonant frequencies are derived and
applied for interpretation of the experimental results.


title: Radiation Studies for the Target Station of the MOMENT

abstract:
  The discovery of the neutrino mixing angle $\theta_{13}$ opens new
opportunities for the discovery of the leptonic CP violation for high intensity
neutrino beams. MOMENT a future neutrino facility with a high-power proton beam
of 15 MW from a continuous-wave linac is focused on that discovery. The high
power of the proton beam causes extreme radiation conditions for the facility
and especially for the target station where the pion capture system of five
superconducting solenoids is located. In this paper initial studies are
performed for the effects of the radiation on the solenoid structure and the
area surrounding it. A concept cooling system is also proposed.


title:
Magnetic properties and Curie temperatures of disordered Heusler
  compounds: Co(1+x)Fe(2-x)Si

abstract:
  The local atomic environments and magnetic properties were investigated for a
series of Co(1+x)Fe(2-x)Si (0<x<1) Heusler compounds. While the total magnetic
moment in these compounds increases with the number of valance electrons, the
highest Curie temperature (Tc) in this series was found for Co1.5Fe1.5Si, with
a Tc of 1069 K (24 K higher than the well known Co2FeSi). 57Fe M\"ossbauer
spectroscopy was used to characterize the local atomic order and to estimate
the Co and Fe magnetic moments. Consideration of the local magnetic moments and
the exchange integrals is necessary to understand the trend in Tc.


title:
Non-iterative Type 4 and 5 Nonuniform FFT Methods in the One-Dimensional
  Case

abstract:
  The so-called non-uniform FFT (NFFT) is a family of algorithms for
efficiently computing the Fourier transform of finite-length signals, whenever
the time or frequency grid is nonuniformly spaced. Following the usual
classification, there exist five NFFT types. Types 1 and 2 make it possible to
pass from the time to the frequency domain with nonuniform input and output
grids respectively. Type 3 allows for both input and output nonuniform grids.
Finally, types 4 and 5 are the inverses of types 1 and 2 and are expensive
computationally, given that they involve iterative methods. In this paper, we
solve this last drawback in the one-dimensional case by presenting
non-iterative type 4 and 5 NFFT methods that just involve three NFFTs of types
1 or 2 plus some additional FFTs. The methods are based on exploiting the
structure of the Lagrange interpolation formula. The paper includes several
numerical examples in which the proposed methods are compared with the Gaussian
elimination (GE) and conjugate gradient (CG) methods, both in terms of
round-off error and computational burden.


title:
Experimentally observed decay of higher-dimensional entanglement through
  turbulence

abstract:
  The evolution of high dimensional entanglement in atmospheric turbulence is
investigated. We study the effects of turbulence on photonic states generated
by spontaneous parametric down-conversion, both theoretically and
experimentally. One of the photons propagates through turbulence, while the
other is left undisturbed. The atmospheric turbulence is simulated by a single
phase screen based on the Kolmogorov theory of turbulence. The output after
turbulence is projected into a three-dimensional (qutrit) basis composed of
specific Laguerre-Gaussian modes. A full state tomography is performed to
determine the density matrix for each output quantum state. These density
matrices are used to determine the amount of entanglement, quantified in terms
of the negativity, as a function of the scintillation strength. Theoretically,
the entanglement is calculated using a single phase screen approximation. We
obtain good agreement between theory and experiment.


title: Superconductivity in the antiperovskite Dirac-metal oxide Sr$_3$SnO

abstract:
  Oxides with perovskite-based structures have been known as essential
materials for fascinating phenomena such as high-temperature and unconventional
superconductivity. Discoveries of these oxide superconductors have driven the
science community to vastly extend the concepts of strongly correlated electron
systems. The base of these materials, the cubic perovskite oxides, $AB$O$_3$,
also exhibit superconductivity with $T_{\mathrm{c}}$ of up to 30 K, as reported
for Ba$_{0.6}$K$_{0.4}$BiO$_3$. Perovskite oxides have their counterparts,
antiperovskite oxides $A_3B$O (or "$B$O$A_3$"), in which the position of metal
and oxygen ions are reversed and therefore metallic $B$ ions take unusual
negative valence states. However, no superconductivity has been reported among
antiperovskite oxides. Here, we report the discovery of the first
superconducting antiperovskite oxide Sr$_3$SnO with $T_{\mathrm{c}}$ of around
5 K. Sr$_3$SnO possesses Dirac points in its electronic structure, originating
from the inversion of bands with different parities. Based on theoretical
analysis, we propose possibility of topological odd-parity superconductivity
analogous to the superfluid $^3$He-B, in moderately hole-doped Sr$_3$SnO,
originating from unusual orbital texture on the Fermi surface. We envision that
this discovery of a new class of oxide superconductor with the inverted valence
configuration will stimulate the exploration of topological materials science
based on a variety of antiperovskite oxides.

categories: cond-mat.supr-con cond-mat.mtrl-sci cond-mat.str-el physics.chem-ph


title:
Stellar populations and Star Formation History of the Metal-Poor Dwarf
  Galaxy DDO 68

abstract:
  We present the star formation history of the extremely metal-poor dwarf
galaxy DDO 68, based on our photometry with the Advanced Camera for Surveys.
With a metallicity of only $12+\log(O/H)=7.15$ and a very isolated location,
DDO 68 is one of the most metal-poor galaxies known. It has been argued that
DDO 68 is a young system that started forming stars only $\sim 0.15$ Gyr ago.
Our data provide a deep and uncontaminated optical color-magnitude diagram that
allows us to disprove this hypothesis, since we find a population of at least
$\sim 1$ Gyr old stars. The star formation activity has been fairly continuous
over all the look-back time. The current rate is quite low, and the highest
activity occurred between 10 and 100 Myr ago. The average star formation rate
over the whole Hubble time is $\simeq 0.01$ M$_{\odot}$ yr$^{-1}$,
corresponding to a total astrated mass of $\simeq 1.3 \times 10^8$ M$_{\odot}$.
Our photometry allows us to infer the distance from the tip of the red giant
branch, $D = 12.08 \pm 0.67$ Mpc; however, to let our synthetic color-magnitude
diagram reproduce the observed ones we need a slightly higher distance,
$D=12.65$ Mpc, or $(m-M)_0 = 30.51$, still inside the errors of the previous
determination, and we adopt the latter. DDO 68 shows a very interesting and
complex history, with its quite disturbed shape and a long Tail probably due to
tidal interactions. The star formation history of the Tail differs from that of
the main body mainly for an enhanced activity at recent epochs, likely
triggered by the interaction.


title: Physics of radio emission in gamma-ray pulsars

abstract:
  Propagation of radio emission in pulsar magnetosphere is reviewed. The
effects of polarization transfer, induced scattering and reprocessing to high
energies are analysed with an especial emphasis on the implications for the
gamma-ray pulsars. The possibilities of the pulsar plasma diagnostics based on
the observed radio pulse characteristics are outlined as well. As an example,
the plasma number density profiles obtained from the polarization data for the
Vela and the gamma-ray millisecond pulsars J1446-4701, J1939+2134 and
J1744-1134 are presented. The number densities derived tend to be the
highest/lowest when the radio pulse leads/lags the gamma-ray peak. In the PSR
J1939+2134, the plasma density profiles for the main pulse and interpulse
appear to fit exactly the same curve, testifying to the origin of both radio
components above the same magnetic pole and their propagation through the same
plasma flow in opposite directions. The millisecond radio pulse components
exhibiting flat position angle curves are suggested to result from the induced
scattering of the main pulse by the same particles that generate gamma-rays.
This is believed to underlie the wide-sense radio/gamma-ray correlation in the
millisecond pulsars. The radio quietness of young gamma-ray pulsars is
attributed to resonant absorption, whereas the radio loudness to the radio beam
escape through the periphery of the open field line tube.


title: Dynamical impact of the Planet Nine scenario: N-body experiments

abstract:
  The Planet Nine hypothesis has now enough constraints to deserve further
attention in the form of detailed numerical experiments. The results of such
studies can help us improve our understanding of the dynamical effects of such
a hypothetical object on the extreme trans-Neptunian objects or ETNOs and
perhaps provide additional constraints on the orbit of Planet Nine itself.
Here, we present the results of direct N-body calculations including the latest
data available on the Planet Nine conjecture. The present-day orbits of the six
ETNOs originally linked to the hypothesis are evolved backwards in time and
into the future under some plausible incarnations of the hypothesis to
investigate if the values of several orbital elements, including the argument
of perihelion, remain confined to relatively narrow ranges. We find that a
nominal Planet Nine can keep the orbits of (90377) Sedna and 2012 VP113
relatively well confined in orbital parameter space for hundreds of Myr, but it
may make the orbits of 2004 VN112, 2007 TG422 and 2013 RF98 very unstable on
time-scales of dozens of Myr, turning them retrograde and eventually triggering
their ejection from the Solar system. Far more stable orbital evolution is
found with slightly modified orbits for Planet Nine.


title:
Novelty Detection in MultiClass Scenarios with Incomplete Set of Class
  Labels

abstract:
  We address the problem of novelty detection in multiclass scenarios where
some class labels are missing from the training set. Our method is based on the
initial assignment of confidence values, which measure the affinity between a
new test point and each known class. We first compare the values of the two top
elements in this vector of confidence values. In the heart of our method lies
the training of an ensemble of classifiers, each trained to discriminate known
from novel classes based on some partition of the training data into
presumed-known and presumednovel classes. Our final novelty score is derived
from the output of this ensemble of classifiers. We evaluated our method on two
datasets of images containing a relatively large number of classes - the
Caltech-256 and Cifar-100 datasets. We compared our method to 3 alternative
methods which represent commonly used approaches, including the one-class SVM,
novelty based on k-NN, novelty based on maximal confidence, and the recent
KNFST method. The results show a very clear and marked advantage for our method
over all alternative methods, in an experimental setup where class labels are
missing during training.


title: Evaluation of the Effect of Improper Segmentation on Word Spotting

abstract:
  Word spotting is an important recognition task in historical document
analysis. In most cases methods are developed and evaluated assuming perfect
word segmentations. In this paper we propose an experimental framework to
quantify the effect of goodness of word segmentation has on the performance
achieved by word spotting methods in identical unbiased conditions. The
framework consists of generating systematic distortions on segmentation and
retrieving the original queries from the distorted dataset. We apply the
framework on the George Washington and Barcelona Marriage Dataset and on
several established and state-of-the-art methods. The experiments allow for an
estimate of the end-to-end performance of word spotting methods.


title:
Electromagnetic Casimir densities for a cylindrical shell on de Sitter
  space

abstract:
  Complete set of cylindrical modes is constructed for the electromagnetic
field inside and outside a cylindrical shell in the background of $(D+1)$%
-dimensional dS spacetime. On the shell, the field obeys the generalized
perfect conductor boundary condition. For the Bunch-Davies vacuum state, we
evaluate the expectation values (VEVs) of the electric field squared and of the
energy-momentum tensor. The shell-induced contributions are explicitly
extracted. In this way, for points away from the shell, the renormalization is
reduced to the one for the VEVs in the boundary-free dS bulk. As a special
case, the VEVs are obtained for a cylindrical shell in the $(D+1)$%
-dimensional Minkowski bulk. We show that the shell-induced contribution in the
electric field squared is positive for both the interior and exterior regions.
The corresponding Casimir-Polder forces are directed toward the shell. The
vacuum energy-momentum tensor, in addition to the diagonal components, has a
nonzero off-diagonal component corresponding to the energy flux along the
direction normal to the shell. This flux is directed from the shell in both the
exterior and interior regions. For points near the shell, the leading terms in
the asymptotic expansions for the electric field squared and diagonal
components of the energy-momentum tensor are obtained from the corresponding
expressions in the Minkowski bulk replacing the distance from the shell by the
proper distance in the dS bulk. The influence of the gravitational field on the
local characteristics of the vacuum is essential at distances from the shell
larger than the dS curvature radius. The results are extended for confining
boundary conditions of flux tube models in QCD.


title: A Revision of the Mool Language

abstract:
  We present here in a thorough analysis of the Mool language, covering not
only its implementation but also the formalisation (syntax, operational
semantics, and type system). The objective is to detect glitches in both the
implementation and in the formal definitions, proposing as well new features
and added expressiveness. To test our proposals we implemented the revision
developed in the Racket platform.


title:
Are there too many uncited articles? Zero inflated variants of the
  discretised lognormal and hooked power law distributions

abstract:
  Although statistical models fit many citation data sets reasonably well with
the best fitting models being the hooked power law and discretised lognormal
distribution, the fits are rarely close. One possible reason is that there
might be more uncited articles than would be predicted by any model if some
articles are inherently uncitable. Using data from 23 different Scopus
categories, this article tests the assumption that removing a proportion of
uncited articles from a citation dataset allows statistical distributions to
have much closer fits. It also introduces two new models, zero inflated
discretised lognormal distribution and the zero inflated hooked power law
distribution and algorithms to fit them. In all 23 cases, the zero inflated
version of the discretised lognormal distribution was an improvement on the
standard version and in 15 out of 23 cases the zero inflated version of the
hooked power law was an improvement on the standard version. Without zero
inflation the discretised lognormal models fit the data better than the hooked
power law distribution 6 out of 23 times and with it, the discretised lognormal
models fit the data better than the hooked power law distribution 9 out of 23
times. Apparently uncitable articles seem to occur due to the presence of
academic-related magazines in Scopus categories. In conclusion, future citation
analysis and research indicators should take into account uncitable articles,
and the best fitting distribution for sets of citation counts from a single
subject and year is either the zero inflated discretised lognormal or zero
inflated hooked power law.


title:
Finite determinacy of matrices over local rings.II. Tangent modules to
  the miniversal deformations for group-actions involving the ring
  automorphisms

abstract:
  We consider matrices with entries in a local ring, Mat(m,n;R). Fix an action
of group G on Mat(m,n;R), and a subset of allowed deformations, \Sigma in
Mat(m,n;R). The standard question (along the lines of Singularity Theory) is
the finite-(\Sigma,G)-determinacy of matrices.
  In our previous work this determinacy question was reduced to the study of
the tangent spaces to \Sigma and to the orbit, T_{(\Sigma,A)}, T_{(GA,A)}, and
their quotient: the tangent module to the miniversal deformation. In
particular, the order of determinacy is controlled by the annihilator of this
tangent module.
  Then we have studied this tangent module for the group action GL(m,R)\times
GL(n,R) on Mat(m,n;R) and for various natural subgroups of it. These are
R-linear group actions.
  In the current work we study this tangent module for group actions that
involve the automorphisms of the ring, or, geometrically, group-actions that
involve the local coordinate changes. (These actions are not R-linear.) We
obtain various bounds on the support of this module. This gives ready-to-use
criteria of determinacy for matrices, (embedded) modules and (skew-)symmetric
forms.


title: Kinematical Quantization

abstract:
  We consider here kinematical quantization: a first and often overlooked step
in quantization procedures. $\mathbb{R}$, $\mathbb{R}_+$ and the interval are
considered, as well as direct (Cartesian) products thereof. Some simple
minisuperspace models, and mode by mode consideration of slightly inhomogeneous
cosmology, have indefinite signature versions of such kinematical
quantizations. The examples in the current paper build in particular toward the
case of vacuum $\mathbb{S}^3$ slightly inhomogeneous cosmology's mode
configuration space, which is mathematically a finite time interval slab of
Minkowski spacetime.


title:
Tunable breakdown of the polaron picture for mobile impurities in a
  topological semimetal

abstract:
  Mobile impurities in cold atomic gases constitute a new platform for
investigating polaron physics. Here we show that when impurity atoms interact
with a two-dimensional Fermi gas with quadratic band touching the polaron
picture may either hold or break down depending on the particle-hole asymmetry
of the band structure. If the hole band has a smaller effective mass than the
particle band, the quasiparticle is stable and its diffusion coefficient varies
with temperature as $D(T) \propto \ln^2 T$. If the hole band has larger mass,
the quasiparticle weight vanishes at low energies due to an emergent
orthogonality catastrophe. In this case we map the problem onto a set of
one-dimensional channels and use conformal field theory techniques to obtain
$D(T)\propto T^{\nu}$ with an interaction-dependent exponent $\nu$. The
different regimes can be detected in the nonequilibrium expansion dynamics of
an initially confined impurity.


title:
Coherent nonlinear optical response of graphene in the quantum Hall
  regime

abstract:
  We study nonlinear optical response of graphene in the quantum Hall regime to
an intense laser pulse. In particular, we consider harmonic generation process.
We demonstrate that the generalized magneto-optical conductivity of graphene on
the harmonics of a strong pump laser radiation has a characteristic Hall
plateaus feature. The plateaus heights depend on the laser intensity and
broadening of Landau levels, so that are not quantized exactly. This nonlinear
effect remains robust against the significant broadening of Landau levels. We
predict realization of an experiment through the observation of the third
harmonic signal and nonlinear Faraday effect, which are within the experimental
feasibility.


title:
The influence of Gaussian strain on sublattice selectivity of impurities
  in graphene

abstract:
  Among the different strategies used to induce the opening of a band gap in
graphene, one common practice is through chemical doping. While a gap may me
opened in this way, disorder-induced scattering is an unwanted side-effect that
impacts the electron mobility in the conductive regime of the system. However,
this undesirable side effect is known to be minimised if dopants interact
asymmetrically with the two sublattices of graphene. In this work we propose
that mechanical strain can be used to introduce such a sublattice asymmetry in
the doping process of graphene. We argue that a localised out-of-plane
deformation applied to a graphene sheet can make one of the graphene
sublattices more energetically favourable for impurity adsorption than the
other and that this can be controlled by varying the strain parameters. Two
complementary modelling schemes are used to describe the electronic structure
of the flat and deformed graphene sheets: a tight-binding model and density
functional theory. Our results indicate a novel way to select the doping
process of graphene through strain engineering.


title:
Knowledge model: a method to evaluate an individual's knowledge
  quantitatively

abstract:
  As the quantity of human knowledge increasing rapidly, it is harder and
harder to evaluate a knowledge worker's knowledge quantitatively. There are
lots of demands for evaluating a knowledge worker's knowledge. For example,
accurately finding out a researcher's research concentrations for the last
three years; searching for common topics for two scientists with different
academic backgrounds; helping a researcher discover his deficiencies on a
research field etc. This paper proposes a method named knowledge model to
evaluate a knowledge worker's knowledge quantitatively without taking an
examination. It records and analyzes an individual's each learning experience,
discovering all the involved knowledge points and calculating their shares by
analyzing the text learning contents with topic model. It calculates a score
for a knowledge point by accumulating the effects of one's all learning
experiences about it. A preliminary knowledge evaluating system is developed to
testify the practicability of knowledge model.


title: Weyl-gauge invariant proof of the Spin-Statistics Theorem

abstract:
  The traditional standard theory of quantum mechanics is unable to solve the
spin-statistics problem, i.e. to justify the utterly important \qo{Pauli
Exclusion Principle} but by the adoption of the complex standard relativistic
quantum field theory. In a recent paper (Ref. [1]) we presented a proof of the
spin-statistics problem in the nonrelativistic approximation on the basis of
the \qo{Conformal Quantum Geometrodynamics}. In the present paper, by the same
theory the proof of the Spin-Statistics Theorem is extended to the relativistic
domain in the general scenario of curved spacetime. The relativistic approach
allows to formulate a manifestly step-by-step Weyl gauge invariant theory and
to emphasize some fundamental aspects of group theory in the demonstration. No
relativistic quantum field operators are used and the particle exchange
properties are drawn from the conservation of the intrinsic helicity of
elementary particles. It is therefore this property, not considered in the
Standard Quantum Mechanics, which determines the correct spin-statistics
connection observed in Nature [1]. The present proof of the Spin-Statistics
Theorem is simpler than the one presented in Ref. [1], because it is based on
symmetry group considerations only, without having recourse to frames attached
to the particles.


title:
On the Properties of a Bundle of Flexible Actin Filaments in an Optical
  Trap

abstract:
  We establish the Statistical Mechanics framework for a bundle of Nf living
and uncrosslinked actin filaments in a supercritical solution of free monomers
pressing against a mobile wall. The filaments are anchored normally to a fixed
planar surface at one of their ends and, because of their limited flexibility,
they grow almost parallel to each other. Their growing ends hit a moving
obstacle, depicted as a second planar wall, parallel to the previous one and
subjected to a harmonic compressive force. The force constant is denoted as
trap strength while the distance between the two walls as trap length to make
contact with the experimental optical trap apparatus. For an ideal solution of
reactive filaments and free monomers at fixed free monomers chemical potential,
we obtain the general expression for the grand potential from which we derive
averages and distributions of relevant physical quantities, namely the obstacle
position, the bundle polymerization force and the number of filaments in direct
contact with the wall. The grafted living filaments are modeled as discrete
Wormlike chains, with Factin persistence length, subject to discrete contour
length variations to model single monomer (de)polymerization steps. Rigid
filaments, either isolated or in bundles, all provide average values of the
stalling force in agreement with Hill's predictions, independent of the average
trap length. Flexible filaments instead, for values of the trap strength
suitable to prevent their lateral escape, provide an average bundle force and
an average trap length slightly larger than the corresponding rigid cases (few
percents). Still the stalling force remains nearly independent on the average
trap length, but results from the product of two strongly L dependent
contributions: the fraction of touching filaments and the single filament
buckling force.


title: On the set of limit points of conditionally convergent series

abstract:
  Let $\sum_{n=1}^\infty x_n$ be a conditionally convergent series in a Banach
space and let $\tau$ be a permutation of natural numbers. We study the set
$\operatorname{LIM}(\sum_{n=1}^\infty x_{\tau(n)})$ of all limit points of a
sequence $(\sum_{n=1}^p x_{\tau(n)})_{p=1}^\infty$ of partial sums of a
rearranged series $\sum_{n=1}^\infty x_{\tau(n)}$. We give full
characterization of limit sets in finite dimensional spaces. Namely, a limit
set in $\mathbb{R}^m$ is either compact and connected or it is closed and all
its connected components are unbounded. On the other hand each set of one of
these types is a limit set of some rearranged conditionally convergent series.
Moreover, this characterization does not hold in infinite dimensional spaces.
  We show that if $\sum_{n=1}^\infty x_n$ has the Rearrangement Property and
$A$ is a closed subset of the closure of the $\sum_{n=1}^\infty x_n$ sum range
and it is $\varepsilon$-chainable for every $\varepsilon>0$, then there is a
permutation $\tau$ such that $A=\operatorname{LIM}(\sum_{n=1}^\infty
x_{\tau(n)})$. As a byproduct of this observation we obtain that series having
the Rearrangement Property have closed sum ranges.


title: Galaxy cluster's rotation

abstract:
  We study the possible rotation of cluster galaxies, developing, testing and
applying a novel algorithm which identifies rotation, if such does exist, as
well as its rotational centre, its axis orientation, rotational velocity
amplitude and, finally, the clockwise or counterclockwise direction of rotation
on the plane of the sky. To validate our algorithms we construct realistic
Monte Carlo mock rotating clusters and confirm that our method provides robust
indications of rotation. We then apply our methodology on a sample of Abell
clusters with z<~0.1 with member galaxies selected from the Sloan Digital Sky
Survey (SDSS) DR10 spectroscopic data base. After excluding a number of
substructured clusters, which could provide erroneous indications of rotation,
and taking into account the expected fraction of misidentified coherent
substructure velocities for rotation, provided by our Monte-Carlo simulation
analysis, we find that ~23% of our clusters are rotating under a set of strict
criteria. Loosening the strictness of the criteria, on the expense of
introducing spurious rotation indications, we find this fraction increasing to
~28%. We correlate our rotation indicators with the cluster dynamical state,
provided either by their Bautz-Morgan type or by their X-ray isophotal shape
and find for those clusters showing rotation within 1.5 h -1 70 Mpc that the
significance of their rotation is related to the dynamically younger phases of
cluster formation but after the initial anisotropic accretion and merging has
been completed. Finally, finding rotational modes in galaxy clusters could lead
to the necessity of correcting the dynamical cluster mass calculations.


title: Reflections on the renormalization procedure for gauge theories

abstract:
  Various pieces of insight were needed to formulate the rules for working with
gauge theories of the electro-magnetic, weak and strong forces. First, it was
needed to understand how to formulate the Feynman rules. We had to learn that
there are many different ways to derive them, and it was needed to know how
different formulations of the gauge constraint lead to the same final results:
the calculated values of the scattering amplitudes. The rules for dealing with
the infinities that had to be subtracted were a big challenge, culminating in
the discovery of the Becchi-Rouet-Stora-Tyutin symmetry. Fond recollections of
the numerous discussions the author had with Raymond Stora on this topic are
memorised here. We end with some reflections on the mathematical status of
quantum field theories, and a letter sent by Stora to the author


title:
Automatic 3D Reconstruction of Manifold Meshes via Delaunay
  Triangulation and Mesh Sweeping

abstract:
  In this paper we propose a new approach to incrementally initialize a
manifold surface for automatic 3D reconstruction from images. More precisely we
focus on the automatic initialization of a 3D mesh as close as possible to the
final solution; indeed many approaches require a good initial solution for
further refinement via multi-view stereo techniques. Our novel algorithm
automatically estimates an initial manifold mesh for surface evolving
multi-view stereo algorithms, where the manifold property needs to be enforced.
It bootstraps from 3D points extracted via Structure from Motion, then iterates
between a state-of-the-art manifold reconstruction step and a novel mesh
sweeping algorithm that looks for new 3D points in the neighborhood of the
reconstructed manifold to be added in the manifold reconstruction. The
experimental results show quantitatively that the mesh sweeping improves the
resolution and the accuracy of the manifold reconstruction, allowing a better
convergence of state-of-the-art surface evolution multi-view stereo algorithms.


title: Feasibility studies for a wireless 60 GHz tracking detector readout

abstract:
  The amount of data produced by highly granular silicon tracking detectors in
high energy physics experiments poses a major challenge to readout systems. At
high collision rates, e.g. at LHC experiments, only a small fraction of data
can be read out with currently used technologies. To cope with the requirements
of future or upgraded experiments new data transfer techniques are required
which offer high data rates at low power and low material budget. Wireless
technologies operating in the 60 GHz band or at higher frequencies offer high
data rates and are thus a promising upcoming alternative to conventional data
transmission via electrical cables or optical fibers. Using wireless
technology, the amount of cables and connectors in detectors can be
significantly reduced. Tracking detectors profit most from a reduced material
budget as fewer secondary particle interactions (multiple Coulomb scattering,
energy loss, etc.) improve the tracking performance in general. We present
feasibility studies regarding the integration of the wireless technology at 60
GHz into a silicon tracking detector. Spare silicon strip modules of the ATLAS
experiment are measured to be opaque in the 60 GHz range. The reduction of
cross talk between links is studied. An estimate of the maximum achievable link
density is given. It is shown that wireless links can be placed as close as 2
cm next to each other for a layer distance of 10 cm by exploiting one or
several of the following measures: highly directive antennas, absorbers, linear
polarization and frequency channeling. Combining these measures, a data rate
area density of up to 11 Tb/(s $\cdot$ m$^2$) seems feasible. In addition, two
types of silicon sensors are tested under mm-wave irradiation . No
deterioration of the performance of both prototypes is observed.


title: The Dynamics of Initiative in Communication Networks

abstract:
  Human social interaction is often intermittent. Two acquainted persons can
have extended periods without social interaction punctuated by periods of
repeated interaction. In this case, the repeated interaction can be
characterized by a seed initiative by either of the persons and a number of
follow-up interactions. The tendency to initiate social interaction plays an
important role in the formation of social networks and is in general not
symmetric between persons. In this paper, we study the dynamics of initiative
by analysing and modeling a detailed call and text message network sampled from
a group of 700 individuals. We show that in an average relationship between two
individuals, one part is almost twice as likely to initiate communication
compared to the other part. The asymmetry has social consequences and
ultimately might lead to the discontinuation of a relationship. We explain the
observed asymmetry by a positive feedback mechanism where individuals already
taking initiative are more likely to take initiative in the future. In general,
people with many initiatives receive attention from a broader spectrum of
friends than people with few initiatives. Lastly, we compare the likelihood of
taking initiative with the basic personality traits of the five factor model.


title: Regularizing properties of Complex Monge-Amp\`ere flows

abstract:
  We study the regularizing properties of complex Monge-Amp\`ere flows on a
K\"ahler manifold $(X,\omega)$ when the initial data are $\omega$-psh functions
with zero Lelong number at all points. We prove that the general Monge-Amp\`ere
flow has a solution which is immediately smooth. We also prove the uniqueness
and stability of solution.


title: Non-equilibrium magnetic fields in ab initio spin dynamics

abstract:
  Starting from the continuity equation for the magnetization in time-dependent
spin-density functional theory, we derive an expression for the effective
time-dependent magnetic fields driving the out-of-equilibrium spin dynamics in
magnetic systems. We evaluate these, so called, kinetic magnetic fields in the
ultrafast demagnetization response to optical pulse excitations of
ferromagnetic iron-based materials, namely Fe$_6$ cluster and bulk bcc Fe. We
identify spatial "hot spots" where the demagnetization is particularly enhanced
as a result of the increased kinetic torque.


title: On determinacy/indeterminacy of Moment Problems

abstract:
  This paper treat determinacy of strong moment problems in part I and
indeterminacy of strong moment problems in part II. This paper is a summary of
the following papers:
  [1] Ald\'en. E., Determinacy of Strong Moment Problems. [2] On Indeterminacy
of Strong Moment Problems. [3] Indeterminacy of Strong Moment Problems.
  This paper will treat determinacy/indeterminacy of the strong Stieltjes and
Hamburger moment problems, part I. Indeterminacy, part II, for certain class of
distribution functions. We conclude by proving a theorem for indeterminacy of
the strong problems above for general distribution functions.


title: Data Structure Lower Bounds for Document Indexing Problems

abstract:
  We study data structure problems related to document indexing and pattern
matching queries and our main contribution is to show that the pointer machine
model of computation can be extremely useful in proving high and unconditional
lower bounds that cannot be obtained in any other known model of computation
with the current techniques. Often our lower bounds match the known space-query
time trade-off curve and in fact for all the problems considered, there is a
very good and reasonable match between the our lower bounds and the known upper
bounds, at least for some choice of input parameters. The problems that we
consider are set intersection queries (both the reporting variant and the
semi-group counting variant), indexing a set of documents for two-pattern
queries, or forbidden- pattern queries, or queries with wild-cards, and
indexing an input set of gapped-patterns (or two-patterns) to find those
matching a document given at the query time.


title:
On a smooth quartic surface containing 56 lines which is isomorphic as a
  K3 surface to the Fermat quartic

abstract:
  We give a defining equation of a complex smooth quartic surface containing 56
lines, and investigate its reductions to positive characteristics. This surface
is isomorphic to the complex Fermat quartic surface, which contains only 48
lines. We give the isomorphism explicitly.


title: First-passage phenomena in hierarchical networks

abstract:
  In this paper we study Markov processes and related first passage problems on
a class of weighted, modular graphs which generalize the Dyson hierarchical
model. In these networks, the coupling strength between two nodes depends on
their distance and is modulated by a parameter $\sigma$. We find that, in the
thermodynamic limit, ergodicity is lost and the "distant" nodes can not be
reached. Moreover, for finite-sized systems, there exists a threshold value for
$\sigma$ such that, when $\sigma$ is relatively large, the inhomogeneity of the
coupling pattern prevails and "distant" nodes are hardly reached. The same
analysis is carried on also for generic hierarchical graphs, where interactions
are meant to involve $p$-plets ($p>2$) of nodes, finding that ergodicity is
still broken in the thermodynamic limit, but no threshold value for $\sigma$ is
evidenced, ultimately due to a slow growth of the network diameter with the
size.


title: Updated galactic radio constraints on Dark Matter

abstract:
  We perform a detailed analysis of the synchrotron signals produced by Dark
Matter annihilations and decays. We consider different set-ups for the
propagation of electrons and positrons, the galactic magnetic field and Dark
Matter properties. We then confront these signals with radio and microwave
maps, including Planck measurements, from a frequency of 22 MHz up to 70 GHz.
We derive two sets of constraints: conservative and progressive, the latter
based on a modeling of the astrophysical emission. Radio and microwave
constraints are complementary to those obtained with other indirect detection
methods, especially for dark matter annihilating into leptonic channels.


title: Shells, orbit bifurcations and symmetry restorations in Fermi systems

abstract:
  The periodic-orbit theory based on the improved stationary-phase method
within the phase-space path integral approach is presented for the
semiclassical description of the nuclear shell structure, concerning the main
topics of the fruitful activity of V. G. Solovjov. We apply this theory to
study bifurcations and symmetry breaking phenomena in a radial power-law
potential which is close to the realistic Woods-Saxon one up to about the Fermi
energy. Using the realistic parametrization of nuclear shapes we explain the
origin of the double-humped fission barrier and the asymmetry in the fission
isomer shapes by the bifurcations of periodic orbits. The semiclassical origin
of the oblate-prolate shape asymmetry and tetrahedral shapes is also suggested
within the improved periodic-orbit approach. The enhancement of shell
structures at some surface diffuseness and deformation parameters of such
shapes are explained by existence of the simple local bifurcations and new
non-local bridge-orbit bifurcations in integrable and partially integrable
Fermi systems. We obtained good agreement between the semiclassical and quantum
shell-structure components of the level density and energy for several surface
diffuseness and deformation parameters of the potentials, including their
symmetry breaking and bifurcation values.


title: Dynamical system approach to scalar-vector-tensor cosmology

abstract:
  Using scalar-vector-tensor Brans Dicke (VBD) gravity [3] in presence of self
interaction BD potential $V(\phi)$ and perfect fluid matter field action we
solve corresponding field equations via dynamical system approach for flat
Friedmann Robertson Walker metric (FRW). We obtained 3 type critical points for
$\Lambda CDM$ vacuum de Sitter era where stability of our solutions are
depended to choose particular values of BD parameter $\omega.$ One of these
fixed points is supported by a constant potential which is stable for
$\omega<0$ and behaves as saddle (quasi stable) for $\omega\geq0.$ Two other
ones are supported by a linear potential $V(\phi)\sim\phi$ which one of them is
stable for $\omega=0.27647.$ For a fixed value of $\omega$ there is at least 2
out of 3 critical points reaching to a unique critical point. Namely for
$\omega=-0.16856(-0.56038)$ the second (third) critical point become unique
with the first critical point. In dust and radiation eras we obtained 1
critical point which never become unique fixed point. In the latter case
coordinates of fixed points are also depended to $\omega.$ To determine
stability of our solutions we calculate eigenvalues of Jacobi matrix of 4D
phase space dynamical field equations for de Sitter, dust and radiation eras.
We should be point also potentials which support dust and radiation eras must
be similar to $V(\phi)\sim\phi^{-\frac{1}{2}}$ and $V(\phi)\sim\phi^{-1}$
respectively. In short our study predicts that radiation and dust eras of our
VBD-FRW cosmology transmit to stable de Sitter state via non-constant potential
(effective variable cosmological parameter) by choosing $\omega=0.27647$.


title: Incorporating Semantic Knowledge into Latent Matching Model in Search

abstract:
  The relevance between a query and a document in search can be represented as
matching degree between the two objects. Latent space models have been proven
to be effective for the task, which are often trained with click-through data.
One technical challenge with the approach is that it is hard to train a model
for tail queries and tail documents for which there are not enough clicks. In
this paper, we propose to address the challenge by learning a latent matching
model, using not only click-through data but also semantic knowledge. The
semantic knowledge can be categories of queries and documents as well as
synonyms of words, manually or automatically created. Specifically, we
incorporate semantic knowledge into the objective function by including
regularization terms. We develop two methods to solve the learning task on the
basis of coordinate descent and gradient descent respectively, which can be
employed in different settings. Experimental results on two datasets from an
app search engine demonstrate that our model can make effective use of semantic
knowledge, and thus can significantly enhance the accuracies of latent matching
models, particularly for tail queries.


title: Cavity Evolution and Instability Constraints of Relativistic Interiors

abstract:
  In this manuscript, we have identified the dynamical instability constraints
of a self-gravitating cylindrical object within the framework of $f(R,T)$
theory of gravity. We have explored the modified field equations and
corresponding dynamical equations for the systematic constructions of our
analysis. We have imposed the linear perturbations on metric and material
variables with some known static profile up to first order in the perturbation
parameter. The role of expansion scalar is also examined in this scenario. The
instability regimes have been discussed in the background of Newtonian and
post-Newtonian limits. We found that the dark source terms due to the influence
of modification in the gravity model is responsible for the instability of the
system.


title: A comparison of remnants in noncommutative Bardeen black holes

abstract:
  We derive the mass term of the Bardeen metric in the presence of a
noncommutative geometry induced minimal length. In this setup, the proposal of
a stable black hole remnant as a candidate to store information is confirmed.
We consider the possibility of having an extremal configuration with one
degenerate event horizon and compare different sizes of black hole remnants. As
a result, once the magnetic charge $g$ of the noncommutative Bardeen solution
becomes larger, both the minimal nonzero mass $M_0$ and the minimal nonzero
horizon radius $r_0$ get larger. This means, subsequently, under the condition
of an adequate amount of $g$, the three parameters $g$, $M_0$, and $r_0$ are in
a connection with each other linearly. According to our results, a
noncommutative Bardeen black hole is colder than the noncommutative
Schwarzschild black hole and its remnant is bigger, so the minimum required
energy for the formation of such a black hole at particle colliders will be
larger. We also find a closely similar result for the Hayward solution.


title:
Hamiltonian finite-temperature quantum field theory from its vacuum on
  partially compactified space

abstract:
  The partition function of a relativistic invariant quantum field theory is
expressed by its vacuum energy calculated on a spatial manifold with one
dimension compactified to a 1-sphere $S^1 (\beta)$, whose circumference $\beta$
represents the inverse temperature. Explicit expressions for the usual energy
density and pressure in terms of the energy density on the partially
compactified spatial manifold $\mathbb{R}^2 \times S^1 (\beta)$ are derived. To
make the resulting expressions mathematically well-defined a Poisson
resummation of the Matsubara sums as well as an analytic continuation in the
chemical potential are required. The new approach to finite-temperature quantum
field theories is advantageous in a Hamilton formulation since it does not
require the usual thermal averages with the density operator. Instead, the
whole finite-temperature behaviour is encoded in the vacuum wave functional on
the spatial manifold $\mathbb{R}^2 \times S^1 (\beta)$. We illustrate this
approach by calculating the pressure of a relativistic Bose and Fermi gas and
reproduce the known results obtained from the usual grand canonical ensemble.
As a first non-trivial application we calculate the pressure of Yang-Mills
theory as function of the temperature in a quasi-particle approximation
motivated by variational calculations in Coulomb gauge.


title: Chinese Song Iambics Generation with Neural Attention-based Model

abstract:
  Learning and generating Chinese poems is a charming yet challenging task.
Traditional approaches involve various language modeling and machine
translation techniques, however, they perform not as well when generating poems
with complex pattern constraints, for example Song iambics, a famous type of
poems that involve variable-length sentences and strict rhythmic patterns. This
paper applies the attention-based sequence-to-sequence model to generate
Chinese Song iambics. Specifically, we encode the cue sentences by a
bi-directional Long-Short Term Memory (LSTM) model and then predict the entire
iambic with the information provided by the encoder, in the form of an
attention-based LSTM that can regularize the generation process by the fine
structure of the input cues. Several techniques are investigated to improve the
model, including global context integration, hybrid style training, character
vector initialization and adaptation. Both the automatic and subjective
evaluation results show that our model indeed can learn the complex structural
and rhythmic patterns of Song iambics, and the generation is rather successful.


title:
Isotoxal star-shaped polygonal voids and rigid inclusions in nonuniform
  antiplane shear fields. Part I: Formulation and full-field solution

abstract:
  An infinite class of nonuniform antiplane shear fields is considered for a
linear elastic isotropic space and (non-intersecting) isotoxal star-shaped
polygonal voids and rigid inclusions perturbing these fields are solved.
Through the use of the complex potential technique together with the
generalized binomial and the multinomial theorems, full-field closed-form
solutions are obtained in the conformal plane. The particular (and important)
cases of star-shaped cracks and rigid-line inclusions (stiffeners) are also
derived. Except for special cases (addressed in Part II), the obtained
solutions show singularities at the inclusion corners and at the crack and
stiffener ends, where the stress blows-up to infinity, and is therefore
detrimental to strength. It is for this reason that the closed-form
determination of the stress field near a sharp inclusion or void is crucial for
the design of ultra-resistant composites.


title:
Using Grassmann calculus in combinatorics: Lindstr\"om-Gessel-Viennot
  lemma and Schur functions

abstract:
  Grassmann (or anti-commuting) variables are extensively used in theoretical
physics. In this paper we use Grassmann variable calculus to give new proofs of
celebrated combinatorial identities such as the Lindstr\"om-Gessel-Viennot
formula for graphs with cycles and the Jacobi-Trudi identity. Moreover, we
define a one parameter extension of Schur polynomials that obey a natural
convolution identity.


title: Quantum State and Process Tomography via Adaptive Measurements

abstract:
  We investigate quantum state tomography (QST) for pure states and quantum
process tomography (QPT) for unitary channels via $adaptive$ measurements. For
a quantum system with a $d$-dimensional Hilbert space, we first propose an
adaptive protocol where only $2d-1$ measurement outcomes are used to accomplish
the QST for $all$ pure states. This idea is then extended to study QPT for
unitary channels, where an adaptive unitary process tomography (AUPT) protocol
of $d^2+d-1$ measurement outcomes is constructed for any unitary channel. We
experimentally implement the AUPT protocol in a 2-qubit nuclear magnetic
resonance system. We examine the performance of the AUPT protocol when applied
to Hadamard gate, $T$ gate ($\pi/8$ phase gate), and controlled-NOT gate,
respectively, as these gates form the universal gate set for quantum
information processing purpose. As a comparison, standard QPT is also
implemented for each gate. Our experimental results show that the AUPT protocol
that reconstructing unitary channels via adaptive measurements significantly
reduce the number of experiments required by standard QPT without considerable
loss of fidelity.


title:
Second--order equation of state with the Skyrme interaction. Cutoff and
  dimensional regularization with the inclusion of rearrangement terms

abstract:
  We evaluate the second--order (beyond--mean--field) contribution to the
equation of state of nuclear matter with the effective Skyrme force and use
cutoff and dimensional regularizations to treat the ultraviolet divergence
produced by the zero--range character of this interaction. An adjustment of the
force parameters is then performed in both cases to remove any double counting
generated by the explicit computation of beyond--mean--field corrections with
the Skyrme force. In addition, we include at second order the rearrangement
terms associated to the density--dependent part of the Skyrme force and discuss
their effect. Sets of parameters are proposed to define new effective forces
which are specially designed for second--order calculations in nuclear matter.


title:
On the problem of deformed spherical systems in Modified Newtonian
  Dynamics

abstract:
  Based on Newtonian dynamics, observations show that the luminous masses of
astrophysical objects that are the size of a galaxy or larger are not enough to
generate the measured motions which they supposedly determine. This is
typically attributed to the existence of dark matter, which possesses mass but
does not radiate (or absorb radiation). Alternatively, the mismatch can be
explained if the underlying dynamics is not Newtonian. Within this conceptual
scheme, Modified Newtonian Dynamics (MOND) is a successful theoretical
paradigm. MOND is usually expressed in terms of a nonlinear Poisson equation,
which is difficult to analyse for arbitrary matter distributions. We study the
MONDian gravitational field generated by slightly non-spherically symmetric
mass distributions based on the fact that both Newtonian and MONDian fields are
conservative (which we refer to as the compatibility condition). As the
non-relativistic version of MOND has two different formulations (AQUAL and
QuMOND) and the compatibility condition can be expressed in two ways, there are
four approaches to the problem in total. The method involves solving a suitably
defined linear deformation potential, which generally depends on the choice of
MOND interpolation function. However, for some specific form of the deformation
potential, the solution is independent of the interpolation function.


title:
Open Problems and Conjectures related to the Theory of Mathematical
  Quasicrystals

abstract:
  This list of problems arose as a collaborative effort among the participants
of the Arbeitsgemeinschaft on Mathematical Quasicrystals, which was held at the
Mathematisches Forschungsinstitut Oberwolfach in October 2015. The purpose of
our meeting was to bring together researchers from a variety of disciplines
with a common goal of understanding different viewpoints and approaches
surrounding the theory of mathematical quasicrystals. The problems reflect this
goal and this diversity and we hope that they will motivate further
cross-disciplinary research and lead to new advances in our overall vision of
this rapidly developing field.


title:
Boundedness and convergence of solutions for the string coupled to a
  nonlinear oscillator

abstract:
  A system of equations consisting of an infinite string coupled to a nonlinear
oscillator is considered. The Cauchy problem for the system with the periodic
initial data is studied. The main goal is to prove the convergence of the
solutions as $t\to\infty$ to a time periodic solution.


title:
Accelerated Douglas-Rachford methods for the solution of convex-concave
  saddle-point problems

abstract:
  We study acceleration and preconditioning strategies for a class of
Douglas-Rachford methods aiming at the solution of convex-concave saddle-point
problems associated with Fenchel-Rockafellar duality. While the basic iteration
converges weakly in Hilbert space with $\mathcal{O}(1/k)$ ergodic convergence
of restricted primal-dual gaps, acceleration can be achieved under
strong-convexity assumptions. Namely, if either the primal or dual functional
in the saddle-point formulation is strongly convex, then the method can be
modified to yield $\mathcal{O}(1/k^2)$ ergodic convergence. In case of both
functionals being strongly convex, similar modifications lead to an asymptotic
convergence of $\mathcal{O}({\vartheta}^k)$ for some $0 < {\vartheta} < 1$. All
methods allow in particular for preconditioning, i.e., the inexact solution of
the implicit linear step in terms of linear splitting methods with all
convergence rates being maintained. The efficiency of the proposed methods is
verified and compared numerically, especially showing competitiveness with
respect to state-of-the-art accelerated algorithms.


title:
A lower bound on the probability that a binomial random variable is
  exceeding its mean

abstract:
  We provide a lower bound on the probability that a binomial random variable
is exceeding its mean. Our proof employs estimates on the mean absolute
deviation and the tail conditional expectation of binomial random variables.


title:
The Impact of Services on Economic Complexity: Service Sophistication as
  Route for Economic Growth

abstract:
  Economic complexity reflects the amount of knowledge that is embedded in the
productive structure of an economy. By combining tools from network science and
econometrics, a robust and stable relationship between a country's productive
structure and its economic growth has been established. Here we report that not
only goods but also services are important for predicting the rate at which
countries will grow. By adopting a terminology which classifies manufactured
goods and delivered services as products, we investigate the influence of
services on the country's productive structure. In particular, we provide
evidence that complexity indices for services are in general higher than those
for goods, which is reflected in a general tendency to rank countries with
developed service sector higher than countries with economy centred on
manufacturing of goods. By focusing on country dynamics based on experimental
data, we investigate the impact of services on the economic complexity of
countries measured in the product space (consisting of both goods and
services). Importantly, we show that diversification of service exports and its
sophistication can provide an additional route for economic growth in both
developing and developed countries.


title: A Novel Approach to Dropped Pronoun Translation

abstract:
  Dropped Pronouns (DP) in which pronouns are frequently dropped in the source
language but should be retained in the target language are challenge in machine
translation. In response to this problem, we propose a semi-supervised approach
to recall possibly missing pronouns in the translation. Firstly, we build
training data for DP generation in which the DPs are automatically labelled
according to the alignment information from a parallel corpus. Secondly, we
build a deep learning-based DP generator for input sentences in decoding when
no corresponding references exist. More specifically, the generation is
two-phase: (1) DP position detection, which is modeled as a sequential
labelling task with recurrent neural networks; and (2) DP prediction, which
employs a multilayer perceptron with rich features. Finally, we integrate the
above outputs into our translation system to recall missing pronouns by both
extracting rules from the DP-labelled training data and translating the
DP-generated input sentences. Experimental results show that our approach
achieves a significant improvement of 1.58 BLEU points in translation
performance with 66% F-score for DP generation accuracy.


title:
Exchange Relations for Finite Type Cluster Algebras with Acyclic Initial
  Seed and Principal Coefficients

abstract:
  We give an explicit description of all the exchange relations in any finite
type cluster algebra with acyclic initial seed and principal coefficients.


title:
Recovery of entire shocked samples in a range of pressure from ~100 GPa
  to Hugoniot Elastic Limit

abstract:
  We carried out laser shock experiments and wholly recovered shocked olivine
and quartz samples. We investigated the petrographic features based on optical
micrographs of sliced samples and found that each recovered sample comprises
three regions, I (optically dark), II (opaque) and III (transparent). Scanning
electron microscopy combined with electron back-scattered diffraction shows
that there are no crystal features in the region I; the materials in the region
I have once melted. Moreover, numerical calculations performed with the iSALE
shock physics code suggest that the boundary between regions II and III
corresponds to Hugoniot Elastic Limit (HEL). Thus, we succeeded in the recovery
of the entire shocked samples experienced over a wide range of pressures from
HEL (~ 10 GPa) to melting pressure (~ 100 GPa) in a hierarchical order.


title: On the lack of bound states for certain NLS equations on metric graphs

abstract:
  The purpose of this paper is to prove some results on the absence of bound
states for certain nonlinear Schr\"odinger equations on noncompact metric
graphs with localized nonlinearity. In particular, we show how the topological
and metric properties of graphs affect the existence/nonexistence of bound
states. This work completes the discussion initiated in [17, 18].


title:
The effects of transients on photospheric and chromospheric power
  distributions

abstract:
  We have observed a quiet Sun region with the Swedish 1-meter Solar Telescope
(SST) equipped with CRISP Imaging SpectroPolarimeter. High-resolution,
high-cadence, H$\alpha$ line scanning images were taken to observe different
layers of the solar atmosphere from the photosphere to upper chromosphere. We
study the distribution of power in different period-bands at different heights.
Power maps of the upper photosphere and the lower chromosphere show suppressed
power surrounding the magnetic-network elements, known as "magnetic shadows".
These also show enhanced power close to the photosphere, traditionally referred
to as "power halos". The interaction between acoustic waves and inclined
magnetic fields is generally believed to be responsible for these two effects.
In this study we explore if small-scale transients can influence the
distribution of power at different heights. We show that the presence of
transients, like mottles, Rapid Blueshifted Excursions (RBEs) and Rapid
Redshifted Excursions (RREs), can strongly influence the power-maps. The short
and finite lifetime of these events strongly affects all powermaps, potentially
influencing the observed power distribution. We show that Doppler-shifted
transients like RBEs and RREs that occur ubiquitously, can have a dominant
effect on the formation of the power halos in the quiet Sun. For magnetic
shadows, transients like mottles do not seem to have a significant effect in
the power suppression around 3 minutes and wave interaction may play a key role
here. Our high cadence observations reveal that flows, waves and shocks
manifest in presence of magnetic fields to form a non-linear
magnetohydrodynamic system.


title:
A look at the inner structure of the $2$-adic ring $C^*$-algebra and its
  automorphism groups

abstract:
  We undertake a systematic study of the so-called $2$-adic ring $C^*$-algebra
$\mathcal{Q}_2$. This is the universal $C^*$-algebra generated by a unitary $U$
and an isometry $S_2$ such that $S_2U=U^2S_2$ and $S_2S_2^*+US_2S_2^*U^*=1$.
Notably, it contains a copy of the Cuntz algebra $\mathcal{O}_2=C^*(S_1, S_2)$
through the injective homomorphism mapping $S_1$ to $US_2$. Among the main
results, the relative commutant $C^*(S_2)'\cap \mathcal{Q}_2$ is shown to be
trivial. This in turn leads to a rigidity property enjoyed by the inclusion
$\mathcal{O}_2\subset\mathcal{Q}_2$, namely the endomorphisms of
$\mathcal{Q}_2$ that restrict to the identity on $\mathcal{O}_2$ are actually
the identity on the whole $\mathcal{Q}_2$. Moreover, there is no conditional
expectation from $\mathcal{Q}_2$ onto $\mathcal{O}_2$. As for the inner
structure of $\mathcal{Q}_2$, the diagonal subalgebra $\mathcal{D}_2$ and
$C^*(U)$ are both proved to be maximal abelian in $\mathcal{Q}_2$. The
maximality of the latter allows a thorough investigation of several classes of
endomorphisms and automorphisms of $\mathcal{Q}_2$. In particular, the
semigroup of the endomorphisms fixing $U$ turns out to be a maximal abelian
subgroup of ${\rm Aut}(\mathcal{Q}_2)$ topologically isomorphic with
$C(\mathbb{T},\mathbb{T})$. Finally, it is shown by an explicit construction
that ${\rm Out}(\mathcal{Q}_2)$ is uncountable and non-abelian.


title:
On {\gamma}-rigid regime of the Bohr-Mottelson Hamiltonian in the
  presence of a minimal length

abstract:
  A prolate {\gamma}-rigid regime of the Bohr-Mottelson Hamiltonian within the
minimal length formalism, involving an infinite square well like potential in
{\beta} collective shape variable, is developed and used to describe the
spectra of a variety of vibrational-like nuclei. The effect of the minimal
length on the energy spectrum and the wave function is duly investigated.
Numerical calculations are performed for some nuclei revealing a qualitative
agreement with the available experimental data.


title: A two-leg Su-Schrieffer-Heeger chain with glide reflection symmetry

abstract:
  The Su-Schrieffer-Heeger (SSH) model lays the foundation of many important
concepts in quantum topological matters. Since it tells one that topological
states may be distinguished by abelian geometric phases, a question naturally
arises as to what happens if one assembles two topologically distinct states.
Here, we show that a spin-dependent double-well optical lattice allows one to
couple two topologically distinct SSH chains in the bulk and realise a
glided-two-leg SSH model that respects the glide reflection symmetry. Such
model gives rise to intriguing quantum phenomena beyond the paradigm of a
traditional SSH model. It is characterised by Wilson line that requires
non-abelian Berry connections, and the interplay between the glide symmetry and
interaction automatically leads to charge fractionalisation without jointing
two lattice potentials at an interface. Our work demonstrates the power of
ultracold atoms to create new theoretical models for studying topological
matters.


title:
Asymptotic and Finite Frame Length Analysis of Frame Asynchronous Coded
  Slotted ALOHA

abstract:
  We consider a frame-asynchronous coded slotted ALOHA (FA-CSA) system where
users become active according to a Poisson random process. In contrast to
standard frame-synchronous CSA (FS-CSA), users transmit a first replica of
their message in the slot following their activation and other replicas
uniformly at random in a number of subsequent slots. We derive the
(approximate) density evolution that characterizes the asymptotic performance
of FA-CSA when the frame length goes to infinity. We show that, if users can
monitor the system before they start transmitting, a boundary-effect similar to
that of spatially-coupled codes occurs, which greatly improves the decoding
threshold as compared to FS-CSA. We also derive analytical approximations of
the error floor (EF) in the finite frame length regime. We show that FA-CSA
yields in general lower EF, better performance in the waterfall region, and
lower average delay, as compared to FS-CSA.


title: Torsion zero cycles with modulus on affine varieties

abstract:
  In this note we show that given a smooth affine variety $X$ over an
algebraically closed field $k$ and an effective (possibly non reduced) Cartier
divisor $D$ on it, the Kerz-Saito Chow group of zero cycles with modulus ${\rm
CH}_0(X|D)$ is torsion free, except possibly for $p$-torsion if the
characteristic of $k$ is $p>0$. This generalizes to the relative setting
classical theorems of Rojtman (for $X$ smooth) and of Levine (for $X$
singular). A stronger version of this result, that encompasses $p$-torsion as
well, was proven with a different and more sophisticated method by A. Krishna
and the author in another paper.


title:
Statistical study of network jets observed in the solar transition
  region: A comparison between coronal holes and quiet sun regions

abstract:
  Recent IRIS observations have revealed a prevalence of intermittent
small-scale jets with apparent speeds of 80 - 250 km s$^{-1}$, emanating from
small-scale bright regions inside network boundaries of coronal holes. We find
that these network jets appear not only in coronal holes but also in quiet-sun
regions. Using IRIS 1330A (C II) slit-jaw images, we extract several parameters
of these network jets, e.g. apparent speed, length, lifetime and increase in
foot-point brightness. Using several observations, we find that some properties
of the jets are very similar but others are obviously different between the
quiet sun and coronal holes. For example, our study shows that the coronal-hole
jets appear to be faster and longer than those in the quiet sun. This can be
directly attributed to a difference in the magnetic configuration of the two
regions with open magnetic field lines rooted in coronal holes and magnetic
loops often present in quiet sun. We have also detected compact bright loops,
likely transition region loops, mostly in quiet sun. These small loop-like
regions are generally devoid of network jets. In spite of different magnetic
structures in the coronal hole and quiet sun in the transition region, there
appears to be no substantial difference for the increase in foot-point
brightness of the jets, which suggests that the generation mechanism of these
network jets is likely the same in both regions.


title:
High-performance functional renormalization group calculations for
  interacting fermions

abstract:
  We derive a novel computational scheme for functional Renormalization Group
(fRG) calculations for interacting fermions on 2D lattices. The scheme is based
on the exchange parametrization fRG for the two-fermion interaction, with
additional insertions of truncated partitions of unity. These insertions
decouple the fermionic propagators from the exchange propagators and lead to a
separation of the underlying equations. We demonstrate that this separation is
numerically advantageous and may pave the way for refined, large-scale
computational investigations even in the case of complex multiband systems.
Furthermore, on the basis of speedup data gained from our implementation, it is
shown that this new variant facilitates efficient calculations on a large
number of multi-core CPUs. We apply the scheme to the $t$,$t'$ Hubbard model on
a square lattice to analyze the convergence of the results with the bond length
of the truncation of the partition of unity. In most parameter areas, a fast
convergence can be observed. Finally, we compare to previous results in order
to relate our approach to other fRG studies.


title:
Octupole correlations in low-lying states of 150Nd and 150Sm and their
  impact on neutrinoless double-beta decay

abstract:
  We present a generator-coordinate calculation, based on a relativistic
energy-density functional, of the low-lying spectra in the isotopes $^{150}$Nd
and $^{150}$Sm and of the nuclear matrix element that governs the neutrinoless
double-beta decay of the first isotope to the second. We carefully examine the
impact of octupole correlations on both nuclear structure and the double-beta
decay matrix element. Octupole correlations turn out to reduce quadrupole
collectivity in both nuclei. Shape fluctuations, however, dilute the effects of
octupole deformation on the double-beta decay matrix element, so that the
overall octupole-induced quenching is only about 7\%.


title:
Analysis of chaotic flow in a 2D multi-turn closed-loop pulsating heat
  pipe

abstract:
  Numerical study has been conducted for the chaotic flow in a multi-turn
closed-loop pulsating heat pipe (PHP). Heat flux and constant temperature
boundary conditions have been applied for heating and cooling sections
respectively. Water was used as working fluid. Volume of Fluid (VOF) method has
been employed for two-phase flow simulation. Volume fraction results showed
formation of perfect vapor and liquid plugs in the fluid flow of PHP.
Non-linear time series analysis, power spectrum density, correlation dimension
and autocorrelation function were used to investigate the chaos. Absence of
dominating peaks in the power spectrum density was a signature of chaos in the
pulsating heat pipe. It was found that by increasing the filling ratio and
evaporator heating power the correlation dimension increases. Decreasing of the
autocorrelation function with respect to time showed the prediction ability is
finite as a result of chaotic state. An optimal filling ratio of 60% and
minimum thermal resistance of 1.62 K/W were found for better thermal
performance of the pulsating heat pipe.


title:
Different evolutionary paths to complexity for small and large
  populations of digital organisms

abstract:
  A major aim of evolutionary biology is to explain the respective roles of
adaptive versus non-adaptive changes in the evolution of complexity. While
selection is certainly responsible for the spread and maintenance of complex
phenotypes, this does not automatically imply that strong selection enhances
the chance for the emergence of novel traits, that is, the origination of
complexity. Population size is one parameter that alters the relative
importance of adaptive and non-adaptive processes: as population size
decreases, selection weakens and genetic drift grows in importance. Because of
this relationship, many theories invoke a role for population size in the
evolution of complexity. Such theories are difficult to test empirically
because of the time required for the evolution of complexity in biological
populations. Here, we used digital experimental evolution to test whether large
or small asexual populations tend to evolve greater complexity. We find that
both small and large---but not intermediate-sized---populations are favored to
evolve larger genomes, which provides the opportunity for subsequent increases
in phenotypic complexity. However, small and large populations followed
different evolutionary paths towards these novel traits. Small populations
evolved larger genomes by fixing slightly deleterious insertions, while large
populations fixed rare beneficial insertions that increased genome size. These
results demonstrate that genetic drift can lead to the evolution of complexity
in small populations and that purifying selection is not powerful enough to
prevent the evolution of complexity in large populations.


title: Current and Cretaceous-Cenozoic diversification of Angiosperms

abstract:
  Cretaceous-Cenozoic history of angiosperms led to the a certain character of
the distribution of taxa of different levels (the number of species and genera
in families, species/genera ratio in families, the number of species in the
genera). In most cases, these distributions are satisfactorily described by a
power law (Pareto distribution). In logarithmic coordinates power function is a
straight line. Empirical curves repeat this line is good enough, but on the
right side of the graph (at low volumes taxa), there is a marked deviation of
theoretical from the empirical curves. This suggests that the small volumes of
taxa should be greater for full compliance with the theoretical curves.
Modeling ratios among genera and species in families showed that only in the
case of dynamic extinction factor observed satisfactory agreement between
observed and calculated the number of species in a wide range of iterations.
This suggested that there was a differential extinction of species during the
evolution of angiosperms. This implies that the rate of extinction had to be
minimal in genera with a large number of species. On the contrary, extinction
rates may be increased by orders of magnitude with a decrease in the number of
species. As a result, large genera became getting bigger and small genera
become less. The species frequencies of distribution in the genera varied
according to a power law. The initial divergence of taxa volume, which led to
their further division into large and small, could be caused by the emergence
and expansion of herbs with their functional and adaptive capabilities.


title:
Method for constructing shortcuts to adiabaticity by a substitute of
  counterdiabatic driving terms

abstract:
  We propose an efficientmethod to construct shortcuts to adiabaticity through
designing a substitute Hamiltonian to try to avoid the defect in which the
speed-up protocol' Hamiltonian may involve terms which are difficult to realize
in practice. We show that as long as the counterdiabatic coupling terms-even
only some of them-have been nullified by the additional Hamiltonian, the
corresponding shortcuts to the adiabatic process could be constructed and the
adiabatic process would be sped up. As an application example, we apply this
method to the popular Landau-Zener model for the realization of fast population
inversion. The results show that in both Hermitian and non-Hermitian systems,
we can design different additional Hamiltonians to replace the traditional
counterdiabatic driving Hamiltonian to speed up the process. This method
provides many choices for designing additional terms of the Hamiltonian such
that one can choose a realizable model in practice.


title:
A Parameterized Algorithmics Framework for Degree Sequence Completion
  Problems in Directed Graphs

abstract:
  There has been intensive work on the parameterized complexity of the
typically NP-hard task to edit undirected graphs into graphs fulfilling certain
given vertex degree constraints. In this work, we lift the investigations to
the case of directed graphs; herein, we focus on arc insertions. To this end,
we develop a general two-stage framework which consists of efficiently solving
a problem-specific number problem and transferring its solution to a solution
for the graph problem by applying flow computations. In this way, we obtain
fixed-parameter tractability and polynomial kernelizability results, with the
central parameter being the maximum vertex in- or outdegree of the output
digraph. Although there are certain similarities with the much better studied
undirected case, the flow computation used in the directed case seems not to
work for the undirected case while $f$-factor computations as used in the
undirected case seem not to work for the directed case.