title:
The first eigenvalue of the $p$-Laplacian on time dependent Riemannian
  metrics

abstract:
  Let $(M,g)$ be an $n$-dimensional compact Riemannian manifold ($n>1$) whose
metric $g(t)$ evolves by the generalized abstract geometric flow. This paper
discusses the evolution, monotonicity and differentiability for the first
eigenvalue of the $p$-Laplacian on $(M,g(t))$ with respect to time evolution.
We prove that the first nonzero $p$-eigenvalue is monotone nondecreasing along
the flow under certain geometric condition and that the first eigenvalue is
differentiable almost everywhere. When $p=2$, we recover the corresponding
results for the usual Laplace-Beltrami operator. Our results provide a unified
approach to the study of $p$-eigenvalue under various geometric flows


title: Magnetic fields in ring galaxies

abstract:
  Many galaxies contain magnetic fields supported by galactic dynamo action.
However, nothing definitive is known about magnetic fields in ring galaxies.
Here we investigate large-scale magnetic fields in a previously unexplored
context, namely ring galaxies, and concentrate our efforts on the structures
that appear most promising for galactic dynamo action, i.e. outer star-forming
rings in visually unbarred galaxies. We use tested methods for modelling
$\alpha-\Omega$ galactic dynamos, taking into account the available
observational information concerning ionized interstellar matter in ring
galaxies. Our main result is that dynamo drivers in ring galaxies are strong
enough to excite large-scale magnetic fields in the ring galaxies studied. The
variety of dynamo driven magnetic configurations in ring galaxies obtained in
our modelling is much richer than that found in classical spiral galaxies. In
particular, various long-lived transients are possible. An especially
interesting case is that of NGC 4513 where the ring counter-rotates with
respect to the disc. Strong shear in the region between the disc and the ring
is associated with unusually strong dynamo drivers for the counter-rotators.
The effect of the strong drivers is found to be unexpectedly moderate. With
counter-rotation in the disc, a generic model shows that a steady mixed parity
magnetic configuration, unknown for classical spiral galaxies, may be excited,
although we do not specifically model NGC 4513. We deduce that ring galaxies
constitute a morphological class of galaxies in which identification of
large-scale magnetic fields from observations of polarized radio emission, as
well as dynamo modelling, may be possible. Such studies have the potential to
throw additional light on the physical nature of rings, their lifetimes and
evolution.


title:
Photometric observations and light curve solutions of the W UMa stars
  NSVS 2244206, NSVS 908513, CSS J004004.7+385531 and VSX J062624.4+570907

abstract:
  Photometric observations in Sloan g' and i' bands of four W UMa stars, NSVS
2244206, NSVS 908513, CSS J004004.7+385531, VSX J062624.4+570907, are
presented. The light curve solutions reveal that all targets have overcontact
configurations with fillout factor within 0.15-0.26. Their components are of
G-K spectral type and almost in thermal contacts. They are relatively close
also in size and luminosity: the radius rations r_2/r_1 are within 0.75-0.90;
the luminosity ratios l_2/l_1 are within 0.53-0.63. The results of the light
curve solution of CSS J004007.7+385531 imply weak limb-darkening effect of its
primary component and possible presence of additional absorbing feature in the
system.


title: Minimising movements for oscillating energies: the critical regime

abstract:
  Minimising movements are investigated for an energy which is the
superposition of a convex functional and fast small oscillations. Thus a
minimising movement scheme involves a temporal parameter $\tau$ and a spatial
parameter $\epsilon$, with $\tau$ describing the time step and the frequency of
the oscillations being proportional to $\frac 1 \epsilon$. The extreme cases of
fast time scales $\tau << \epsilon$ and slow time scales $\epsilon << \tau$
have been investigated in Braides, Springer Lecture Notes 2094 (2014). In this
article, the intermediate (critical) case of finite ratio $\epsilon/\tau>0$ is
studied. It is shown that a pinning threshold exists, with initial data below
the threshold being a fixed point of the dynamics. A characterisation of the
pinning threshold is given. For initial data above the pinning threshold, the
equation and velocity describing the homogenised motion are determined.


title:
From Sazonov's Non-Dcpo Natural Domains to Closed Directed-Lub Partial
  Orders

abstract:
  Normann proved that the domains of the game model of PCF (the domains of
sequential functionals) need not be dcpos. Sazonov has defined natural domains
for a theory of such incomplete domains. This paper further develops that
theory. It defines lub-rules that infer natural lubs from existing natural
lubs, and lub-rule classes that describe axiom systems like that of natural
domains. There is a canonical proper subcategory of the natural domains, the
closed directed lub partial orders (cdlubpo), that corresponds to the complete
lub-rule class of all valid lub-rules. Cdlubpos can be completed to restricted
dcpos, which are dcpos that retain the data of the incomplete cdlubpo as a
subset.


title: Measure Theoretic Aspects Of Error Terms

abstract:
  This thesis investigates on measure theoretic aspects of fluctuations of
error terms appearing in various asymptotic formulas.


title:
A note on the augmented Zagreb index of cacti with fixed number of
  vertices and cycles

abstract:
  Let $\mathcal{C}_{n,k}$ be the family of all cacti with $k$ cycles and
$n\geq4$ vertices. In the present note, the element of the class
$\mathcal{C}_{n,k}$ having minimum augmented Zagreb index ($AZI$) is
characterized. Moreover, some structural properties of the graph(s) having
maximum $AZI$ value over the collection $\mathcal{C}_{n,0}$, are also reported.


title:
Flexible objective Bayesian linear regression with applications in
  survival analysis

abstract:
  We study objective Bayesian inference for linear regression models with
residual errors distributed according to the class of two-piece scale mixtures
of normal distributions. These models allow for capturing departures from the
usual assumption of normality of the errors in terms of heavy tails, asymmetry,
and certain types of heteroscedasticity. We propose a general noninformative,
scale-invariant, prior structure and provide sufficient conditions for the
propriety of the posterior distribution of the model parameters, which cover
cases when the response variables are censored. These results allow us to apply
the proposed models in the context of survival analysis. This paper represents
an extension to the Bayesian framework of the models proposed in Rubio and Hong
(2015). We present a simulation study that shows good frequentist properties of
the posterior credible intervals as well as point estimators associated to the
proposed priors. We illustrate the performance of these models with real data
in the context of survival analysis of cancer patients.


title: The Ricci tensor of almost parahermitian manifolds

abstract:
  We study the pseudoriemannian geometry of almost parahermitian manifolds,
obtaining a formula for the Ricci tensor of the Levi-Civita connection. The
formula uses the intrinsic torsion of an underlying SL(n,R)-structure; we
express it in terms of exterior derivatives of some appropriately defined
differential forms. As an application, we construct Einstein and Ricci-flat
examples on Lie groups. We disprove the parak\"ahler version of the Goldberg
conjecture, and obtain the first compact examples of a non-flat, Ricci-flat
nearly parak\"ahler structure. We study the paracomplex analogue of the first
Chern class in complex geometry, which obstructs the existence of Ricci-flat
parak\"ahler metrics.


title: Bounds on collapse models from cold-atom experiments

abstract:
  The spontaneous localization mechanism of collapse models induces a Brownian
motion in all physical systems. This effect is very weak, but experimental
progress in creating ultracold atomic systems can be used to detect it. In this
paper, we considered a recent experiment [1], where an atomic ensemble was
cooled down to picokelvins. Any Brownian motion induces an extra increase of
the position variance of the gas. We study this effect by solving the dynamical
equations for the Continuous Spontaneous Localizations (CSL) model, as well as
for its non-Markovian and dissipative extensions. The resulting bounds, with a
95% of confidence level, are beaten only by measurements of spontaneous X-ray
emission and by experiments with cantilever (in the latter case, only for rC >
10^(-7) m, where rC is one of the two collapse parameters of the CSL model). We
show that, contrary to the bounds given by X-ray measurements, non-Markovian
effects do not change the bounds, for any reasonable choice of a frequency
cutoff in the spectrum of the collapse noise. Therefore the bounds here
considered are more robust. We also show that dissipative effects are
unimportant for a large spectrum of temperatures of the noise, while for low
temperatures the excluded region in the parameter space is the more reduced,
the lower the temperature.


title:
Response to the Comment by Haack et al. (2015) on the paper by
  Anfinogenov et al. (2014): John's stone: A possible fragment of the 1908
  Tunguska meteorite

abstract:
  The article provides an open discussion and a critical feedback to the
comments of Haack et al. (2015) and emphasizes a significance of the first
macroscopic evidence for a candidate meteorite of a new type: planetary-origin
meteorite composed of silica-rich sedimentary rock. Discussion concerns the
arguments for (i) candidate parental bodies including the Earth, Mars and icy
moons of Saturn and Jupiter; (ii) PGE anomaly versus glassy silicate
microspherules and quartz grains anomaly in the area of the 1908 Tunguska
catastrophe; (iii) isotopic heterogeneity of unmixed silicate reservoirs on
Mars; (iv) possible terrestrial loss or contamination in the noble gas
signatures in meteorites that spent time in the extreme weather conditions; (v)
cosmogenic isotopes and shielding; and (vi) pseudo meteorites. We conclude that
the list of candidate parental bodies for hypothetical sedimentary-origin
meteorites includes, but is not limited by the Earth, Mars, Enceladus,
Ganymede, and Europa. A parental body should be identified based on the entire
body of evidence which is not limited solely by tests of oxygen and noble gas
isotopes whose signatures may undergo terrestrial contamination and may exhibit
significant heterogeneity within the parental bodies.


title:
Metric dynamics for membrane transformation through regulated cell
  proliferation

abstract:
  This study develops an equation for describing three-dimensional membrane
transformation through proliferation of its component cells regulated by
morphogen density distributions on the membrane. The equation is developed in a
two-dimensional coordinate system mapped on the membrane, referred to as the
membrane coordinates. When the membrane expands, the membrane coordinates
expand in the same manner so that the membrane is invariant in the coordinates.
In the membrane coordinate system, the transformation of membrane is described
with a time-derivative equation for metric tensors. By defining relationships
between morphogen density distributions and the direction and rate of cell
division, trajectories of membrane transformation are obtained in terms of the
morphogen distributions. An example of the membrane transformation is shown
numerically.


title: Chimera patterns in the Kuramoto-Battogtokh model

abstract:
  Kuramoto and Battogtokh [Nonlinear Phenom. Complex Syst. 5, 380 (2002)]
discovered chimera states represented by stable coexisting synchrony and
asynchrony domains in a lattice of coupled oscillators. After reformulation in
terms of local order parameter, the problem can be reduced to partial
differential equations. We find uniformly rotating periodic in space chimera
patterns as solutions of a reversible ordinary differential equation, and
demonstrate a plethora of such states. In the limit of neutral coupling they
reduce to analytical solutions in form of one- and two-point chimera patterns
as well as localized chimera solitons. Patterns at weakly attracting coupling
are characterized by virtue of a perturbative approach. Stability analysis
reveals that only simplest chimeras with one synchronous region are stable.


title:
Sentiment-enhanced Multidimensional Analysis of Online Social Networks:
  Perception of the Mediterranean Refugees Crisis

abstract:
  We propose an analytical framework able to investigate discussions about
polarized topics in online social networks from many different angles. The
framework supports the analysis of social networks along several dimensions:
time, space and sentiment. We show that the proposed analytical framework and
the methodology can be used to mine knowledge about the perception of complex
social phenomena. We selected the refugee crisis discussions over Twitter as
the case study. This difficult and controversial topic is an increasingly
important issue for the EU. The raw stream of tweets is enriched with space
information (user and mentioned locations), and sentiment (positive vs.
negative) w.r.t. refugees. Our study shows differences in positive and negative
sentiment in EU countries, in particular in UK, and by matching events,
locations and perception it underlines opinion dynamics and common prejudices
regarding the refugees.


title:
On Stress-Strain Responses and Young's Moduli of Single Alkane
  Molecules, A Molecular Mechanics Study Using the Modified Embedded-Atom
  Method

abstract:
  In this work, molecular mechanics simulations were performed using a modified
embedded-atom method (MEAM) potential to generate the stress-strain responses
of a series of n-alkane molecules from ethane (C$_2$H$_6$) to undecane
(n-C$_{11}$H$_{24}$) in tensile deformation up to the point of bond rupture.
The results are further generalized to a single polyethylene (PE) chain. Force,
true Cauchy stress, true virial stress, and Young's moduli were calculated as a
function of true strain for all of the molecules. In calculating the stress of
a single molecule, three methods (designated in this work as M1, M2, and M3)
are suggested based on three different metrics to quantify both the
instantaneous molecular cross-sectional area and volume during deformation. The
predictions of these methods are compared to theoretical, first-principles, and
experimental data. M1 gives true Cauchy and true virial stress results that are
essentially equivalent, suggesting that it is a better method for calculating
stress in alkane molecules and, hence, PE single chain. The MEAM predictions of
the average elastic modulus for a single PE chain using M1, M2, and M3 are 401
GPa, 172 GPa, and 147 GPa, respectively. Though these results are disparate, M1
gives a modulus value that is strikingly close to the ab initio-calculated
value of 405 GPa for the -CH$_2$CH$_2$- repeat unit of PE at 0 K. To further
test the MEAM potential, the Young's modulus (C$_{33}$ elastic constant) of an
orthorhombic PE crystal cell was calculated, but its value (184 GPa)
underestimates the DFT-calculated value of 316 GPa by 42%.


title:
Parabolic conformally symplectic structures II; parabolic
  contactification

abstract:
  Parabolic almost conformally symplectic structures were introduced in the
first part of this series of articles as a class of geometric structures which
have an underlying almost conformally symplectic structure. If this underlying
structure is conformally symplectic, then one obtains a PCS-structure. In the
current article, we relate PCS-structures to parabolic contact structures.
Starting from a parabolic contact structure with a transversal infinitesimal
automorphism, we first construct a natural PCS-structure on any leaf space of
the corresponding foliation. Then we develop a parabolic version of
contactification to show that any PCS-structure can be locally realized
(uniquely up to isomorphism) in this way.
  In the second part of the paper, these results are extended to an analogous
correspondence between contact projective structures and so-called conformally
Fedosov structures. The developments in this article provide the technical
background for a construction of sequences and complexes of differential
operators which are naturally associated to PCS-structures by pushing down BGG
sequences on parabolic contact structures. This is the topic of the third part
of this series of articles.


title: Boosted scalar confronting 750 GeV di-photon excess

abstract:
  We consider the di-photon signal arises from two bunches of collimated photon
jets emitting from a pair of highly boosted scalars. Following the discussion
of detecting the photon jets at the collider, we extend the two-Higgs-doublet
model (2HDM) by adding a gauge singlet scalar. To explain the di-photon excess
which is recently observed at the first 13 TeV run of the LHC, the mixing
between the heavy doublet state and the newly added singlet is crucially
needed. After the mixing, one can have a heavy Higgs state $Y_2$ at 750 GeV and
a very singlet-like scalar $Y_1$ of sub-GeV, which would be highly boosted
through the $Y_2$ decay. Both real singlet and complex singlet extension are
studied. It turns out that only the complex model can yield the 1-10 fb cross
section in the di-photon final state in accompany with the decay length of the
order of 1 m for the $Y_1$. This complex model parametrically predicts the
width of 750 GeV resonance $\gtrsim 1$ GeV. In addition, the pseudoscalar
component of the singlet in this model is naturally stable and hence could be a
dark matter candidate.


title:
Mixed type multiple orthogonal polynomials associated with the modified
  Bessel functions and products of two coupled random matrices

abstract:
  We consider mixed type multiple orthogonal polynomials associated with a
system of weight functions consisting of two vectors. One vector is defined in
terms of scaled modified Bessel function of the first kind $I_\mu$ and
$I_{\mu+1}$, the other vector is defined in terms of scaled modified Bessel
function of the second kind $K_\nu$ and $K_{\nu+1}$. We show that the
corresponding mixed type multiple orthogonal polynomials exist. For the special
case that each multi-index is on or close to the diagonal, basic properties of
the polynomials and their linear forms are investigated, which include explicit
formulas, integral representations, differential properties, limiting forms and
recurrence relations. It comes out that, for specified parameters, the linear
forms of these mixed type multiple orthogonal polynomials can be interpreted as
biorthogonal functions encountering in recent studies of products of two
coupled random matrices. This particularly implies a Riemann-Hilbert
characterization of the correlation kernel, which provides an alternative way
for further asymptotic analysis.


title: Optically probing symmetry breaking in the chiral magnet Cu2OSeO3

abstract:
  We report on the linear optical properties of the chiral magnet Cu2OSeO3,
specifically associated with the absence of inversion symmetry, the chiral
crystallographic structure, and magnetic order. Through spectroscopic
ellipsometry, we observe local crystal-field excitations below the
charge-transfer gap. These crystal-field excitations are optically allowed due
to the lack of inversion symmetry at the Cu sites. Optical polarization
rotation measurements were used to study the structural chirality and magnetic
order. The temperature dependence of the natural optical rotation, originating
in the chiral crystal structure, provides evidence for a finite
magneto-electric effect in the helimagnetic phase. We find a large
magneto-optical susceptibility on the order of V(540nm)~10^4 rad/(T*m) in the
helimagnetic phase and a maximum Faraday rotation of ~165deg/mm in the
ferrimagnetic phase. The large value of V can be explained by considering spin
cluster formation and the relative ease of domain reorientation in this
metamagnetic material. The magneto-optical activity allows us to map the
magnetic phase diagram, including the skyrmion lattice phase. In addition to
this, we probe and discuss the nature of the various magnetic phase transitions
in Cu2OSeO3.


title: Bridging Online and Offline Social Networks: Multiplex Analysis

abstract:
  We show that three basic actor characteristics, namely normalized
reciprocity, three cycles, and triplets, can be expressed using an unified
framework that is based on computing the similarity index between two sets
associated with the actor: the set of her/his friends and the set of those
considering her/him as a friend. These metrics are extended to multiplex
networks and then computed for two friendship networks generated by collecting
data from two groups of undergraduate students. We found that in offline
communication strong and weak ties are (almost) equally presented, while in
online communication weak ties are dominant. Moreover, weak ties are much less
reciprocal than strong ties. However, across different layers of the multiplex
network reciprocities are preserved, while triads (measured with normalized
three cycles and triplets) are not significant.


title: Extremely long-lived magnetic excitations in supported Fe chains

abstract:
  We report on a theoretical study of the lifetime of the first excited state
of spin chains made of an odd number of Fe atoms on Cu2N/Cu(100). Yan et al
(Nat. Nanotech. 10, 40 (2015)) recently observed very long lifetimes in the
case of Fe3 chains. We consider the decay of the first excited state induced by
electron-hole pair creation in the substrate. For a finite magnetic field, the
two lowest-lying states in the chain have a quasi-N\'eel state structure. Decay
from one state to the other strongly depends on the degree of entanglement of
the local spins in the chain. The entanglement in the chain accounts for the
long lifetimes that increase exponentially with chain length. Despite their
apparently very different properties, the behaviour of odd and even chains is
governed by the same kind of phenomena, in particular entanglement effects. The
present results account quite well for the lifetimes recently measured by Yan
et al on Fe3


title: Deterministic Leader Election Takes $\Theta(D + \log n)$ Bit Rounds

abstract:
  Leader election is, together with consensus, one of the most central problems
in distributed computing. This paper presents a distributed algorithm, called
\STT, for electing deterministically a leader in an arbitrary network, assuming
processors have unique identifiers of size $O(\log n)$, where $n$ is the number
of processors. It elects a leader in $O(D +\log n)$ rounds, where $D$ is the
diameter of the network, with messages of size $O(1)$. Thus it has a bit round
complexity of $O(D +\log n)$. This substantially improves upon the best known
algorithm whose bit round complexity is $O(D\log n)$. In fact, using the lower
bound by Kutten et al. (2015) and a result of Dinitz and Solomon (2007), we
show that the bit round complexity of \STT is optimal (up to a constant
factor), which is a significant step forward in understanding the interplay
between time and message optimality for the election problem. Our algorithm
requires no knowledge on the graph such as $n$ or $D$, and the pipelining
technique we introduce to break the $O(D\log n)$ barrier is general.


title: On Dimensional Reduction of Magical Supergravity Theories

abstract:
  We prove, by a direct dimensional reduction and an explicit construction of
the group manifold, that the nonlinear sigma model of the dimensionally reduced
three-dimensional A = R magical supergravity is F4(+4)/(USp(6)xSU(2)). This
serves as a basis for the solution generating technique in this supergravity as
well as allows to give the Lie algebraic characterizations to some of the
parameters and functions in the original D = 5 Lagrangian. Generalizations to
other magical supergravities are also discussed.


title: What can topology tell us about the neural code?

abstract:
  Neuroscience is undergoing a period of rapid experimental progress and
expansion. New mathematical tools, previously unknown in the neuroscience
community, are now being used to tackle fundamental questions and analyze
emerging data sets. Consistent with this trend, the last decade has seen an
uptick in the use of topological ideas and methods in neuroscience. In this
talk I will survey recent applications of topology in neuroscience, and explain
why topology is an especially natural tool for understanding neural codes.
Note: This is a write-up of my talk for the Current Events Bulletin, held at
the 2016 Joint Math Meetings in Seattle, WA.


title: SuperDARN scalar radar equations

abstract:
  The quadratic scalar radar equations are obtained for SuperDARN radars that
are suitable for the analysis and interpretation of experimental data. The
paper is based on a unified approach to the obtaining radar equations for the
monostatic and bistatic sounding with use of hamiltonian optics and ray
representation of scalar Green's function and without taking into account the
polarization effects. The radar equation obtained is the sum of several terms
corresponding to the propagation and scattering over the different kinds of
trajectories, depending on their smoothness and the possibility of reflection
from the ionosphere. It is shown that the monostatic sounding in the media with
significant refraction, unlike the case of refraction-free media, should be
analyzed as a combination of monostatic and bistatic scattering. This leads to
strong dependence of scattering amplitude on background ionospheric density due
to focusing mechanism and appearance of new (bistatic) areas of effective
scattering with significant distortion of the scattered signal spectrum.
Selective properties of the scattering also have been demonstrated.


title: Hamiltonian YM 2+1: note on point splitting regularization

abstract:
  The Hamiltonian of 2+1 dimensional Yang Mills theory was derived by Karabali,
Kim and Nair by using point splitting regularization. But in calculating e.g.
the vacuum wave functional this scheme was left in favour of arguments. Here we
follow up a conjecture of Leigh, Minic and Yelnikov of how this gap might be
filled by including all positive powers of the regularization parameter ($\ep
\to +0$). Admittedly, though we concentrate on the ground state in the large
$N$ limit, only two such powers could be included due to the increasing
complexity of the task.


title: Superconducting gap structure of FeSe

abstract:
  The microscopic mechanism governing the zero-resistance flow of current in
some iron-based, high-temperature superconducting materials is not well
understood up to now. A central issue concerning the investigation of these
materials is their superconducting gap symmetry and structure. Here we present
a combined study of low-temperature specific heat and scanning tunnelling
microscopy measurements on single crystalline FeSe. The results reveal the
existence of at least two superconducting gaps which can be represented by a
phenomenological two-band model. The analysis of the specific heat suggests
significant anisotropy in the gap magnitude with deep gap minima. The tunneling
spectra display an overall "U"-shaped gap close to the Fermi level away as well
as on top of twin boundaries. These results are compatible with the anisotropic
nodeless models describing superconductivity in FeSe.


title: Equilibrium measures in the presence of weak rational external fields

abstract:
  In this paper equilibrium measures in the presence of external fields created
by fixed charges are analyzed. These external fields are a particular case of
the so-called rational external fields (in the sense that their derivatives are
rational functions). Along with some general results, a thorough analysis of
the particular case of two fixed negative charges (``attractors') is presented.
As for the main tools used, this paper is a natural continuation of
\cite{MOR2015}, where polynomial external fields were thoroughly studied, and
\cite{OrSL2015}, where rational external fields with a polynomial part were
considered. However, the absence of the polynomial part in the external fields
analyzed in the current paper adds a considerable difficulty to solve the
problem and justifies its separated treatment; moreover, it is noteworthy to
point out the simplicity and beauty of the results obtained.


title: Creating lenticular galaxies with major mergers

abstract:
  Lenticular galaxies (S0s) represent the majority of early-type galaxies in
the local Universe, but their formation channels are still poorly understood.
While galaxy mergers are obvious pathways to suppress star formation and
increase bulge sizes, the marked parallelism between spiral and lenticular
galaxies (e.g. photometric bulge-disc coupling) seemed to rule out a potential
merger origin. Here, we summarise our recent work in which we have shown,
through N-body numerical simulations, that disc-dominated lenticulars can
emerge from major mergers of spiral galaxies, in good agreement with
observational photometric scaling relations. Moreover, we show that mergers
simultaneously increase the light concentration and reduce the angular momentum
relative to their spiral progenitors. This explains the mismatch in angular
momentum and concentration between spirals and lenticulars recently revealed by
CALIFA observations, which is hard to reconcile with simple fading mechanisms
(e.g. ram-pressure stripping).


title:
Critical behaviour of ($2+1$)-dimensional QED: 1/N_f-corrections in the
  Landau gauge

abstract:
  The dynamical generation of a fermion mass is studied within
($2+1$)-dimensional QED with $N$ four-component fermions in the leading and
next-to-leading orders of the 1/N expansion. The analysis is carried out in the
Landau gauge which is supposed to insure the gauge independence of the critical
fermion flavour number, N_c. It is found that the dynamical fermion mass
appears for N<N_c where N_c=3.29, that is only about $1\%$ larger than its
value at leading order.


title:
Magnetic shift of the chemical freezeout and electric charge
  fluctuations

abstract:
  We discuss the effect of a strong magnetic field on the chemical freezeout
points in the ultrarelativistic heavy-ion collision. As a result of the inverse
magnetic catalysis or the magnetic inhibition, the crossover onset to hot and
dense matter out of quarks and gluons should be shifted to a lower temperature.
To quantify this shift we employ the hadron resonance gas model and an
empirical condition for the chemical freezeout. We point out that the charged
particle abundances are significantly affected by the magnetic field so that
the electric charge fluctuation is largely enhanced especially at high baryon
density. The charge conservation partially cancels the enhancement but our
calculation shows that the electric charge fluctuation and the charge chemical
potential could serve as a magnetometer. We find that the fluctuation exhibits
a crossover behavior rapidly increased for eB >~ (0.4GeV)^2, while the charge
chemical potential has better sensitivity to the magnetic field.


title: Torsion orders of complete intersections

abstract:
  By a classical result of Roitman, a complete intersection $X$ of sufficiently
small degree admits a rational decomposition of the diagonal. This means that
some multiple of the diagonal by a positive integer $N$, when viewed as a cycle
in the Chow group, has support in $X\times D\cup F\times X$, for some divisor
$D$ and a finite set of closed points $F$. The minimal such $N$ is called the
torsion order. We study lower bounds for the torsion order following the
specialization method of Voisin, Colliot-Th\'el\`ene and Pirutka. We give a
lower bound for the generic complete intersection with and without point.
Moreover, we use methods of Koll\'ar and Totaro to show lower bounds for the
very general complete intersection.


title:
Electromagnetic Imaging with Atomic Magnetometers: A Novel Approach to
  Security and Surveillance

abstract:
  We describe our research programme on the use of atomic magnetometers to
detect conductive objects via electromagnetic induction. The extreme
sensitivity of atomic magnetometers at low frequencies, up to seven orders of
magnitude higher than a coil-based system, permits deep penetration through
different media and barriers, and in various operative environments. This
eliminates the limitations usually associated with electromagnetic detection.


title: Lepton Flavor Violation in the singlet-triplet scotogenic model

abstract:
  We investigate lepton flavor violation (LFV) in the the singlet-triplet
scotogenic model in which neutrinos acquire non-zero masses at the 1-loop
level. In contrast to the most popular variant of this setup, the singlet
scotogenic model, this version includes a triplet fermion as well as a triplet
scalar, leading to a scenario with a richer dark matter phenomenology. Taking
into account results from neutrino oscillation experiments, we explore some
aspects of the LFV phenomenology of the model. In particular, we study the
relative weight of the dipole operators with respect to other contributions to
the LFV amplitudes and determine the most constraining observables. We show
that in large portions of the parameter space, the most promising experimental
perspectives are found for LFV 3-body decays and for coherent $\mu-e$
conversion in nuclei.


title: Quantum change point

abstract:
  Sudden changes are ubiquitous in nature. Identifying them is of crucial
importance for a number of applications in medicine, biology, geophysics, and
social sciences. Here we investigate the problem in the quantum domain,
considering a source that emits particles in a default state, until a point
where it switches to another state. Given a sequence of particles emitted by
the source, the problem is to find out where the change occurred. For large
sequences, we obtain an analytical expression for the maximum probability of
correctly identifying the change point when joint measurements on the whole
sequence are allowed. We also construct strategies that measure the particles
individually and provide an online answer as soon as a new particle is emitted
by the source. We show that these strategies substantially underperform the
optimal strategy, indicating that quantum sudden changes, although happening
locally, are better detected globally.


title: Dynamical and structural signatures of the glass transition in emulsions

abstract:
  We investigate structural and dynamical properties of moderately polydisperse
emulsions across an extended range of droplet volume fractions phgr,
encompassing fluid and glassy states up to jamming. Combining experiments and
simulations, we show that when $\phi$ approaches the glass transition volume
fraction ${{\phi}_{g}}$ , dynamical heterogeneities and amorphous order arise
within the emulsion. In particular, we find an increasing number of clusters of
particles having five-fold symmetry (i.e. the so-called locally favoured
structures, LFS) as $\phi$ approaches ${{\phi}_{g}}$ , saturating to a roughly
constant value in the glassy regime. However, contrary to previous studies, we
do not observe a corresponding growth of medium-range crystalline order;
instead, the emergence of LFS is decoupled from the appearance of more ordered
regions in our system. We also find that the static correlation lengths
associated with the LFS and with the fastest particles can be successfully
related to the relaxation time of the system. By contrast, this does not hold
for the length associated with the orientational order. Our study reveals the
existence of a link between dynamics and structure close to the glass
transition even in the absence of crystalline precursors or crystallization.
Furthermore, the quantitative agreement between our confocal microscopy
experiments and Brownian dynamics simulations indicates that emulsions are and
will continue to be important model systems for the investigation of the glass
transition and beyond.


title:
$\zeta^2$ Ret, its debris disk, and its lonely stellar companion
  $\zeta^1$ Ret. Different $T_{\mathrm{c}}$ trends for different spectra

abstract:
  Several studies have reported a correlation between the chemical abundances
of stars and condensation temperature (known as Tc trend). Very recently, a
strong Tc trend was reported for the $\zeta$ Reticuli binary system, which
consists of two solar analogs. The observed trend in $\zeta^2$ Ret relative to
its companion was explained by the presence of a debris disk around $\zeta^2$
Ret. Our goal is to re-evaluate the presence and variability of the Tc trend in
the $\zeta$ Reticuli system and to understand the impact of the presence of the
debris disk on a star. We used very high-quality spectra of the two stars
retrieved from the HARPS archive to derive very precise stellar parameters and
chemical abundances. We derived the stellar parameters with the classical
(nondifferential) method, while we applied a differential line-by-line analysis
to achieve the highest possible precision in abundances, which are fundamental
to explore for very tiny differences in the abundances between the stars. We
confirm that the abundance difference between $\zeta^2$ Ret and $\zeta^1$ Ret
shows a significant ($\sim$ 2 $\sigma$) correlation with Tc. However, we also
find that the Tc trends depend on the individual spectrum used (even if always
of very high quality). In particular, we find significant but varying
differences in the abundances of the same star from different individual
high-quality spectra. Our results for the $\zeta$ Reticuli system show, for
example, that nonphysical factors, such as the quality of spectra employed and
errors that are not accounted for, can be at the root of the Tc trends for the
case of individual spectra.


title: User Reviews and Language: How Language Influences Ratings

abstract:
  The number of user reviews of tourist attractions, restaurants, mobile apps,
etc. is increasing for all languages; yet, research is lacking on how reviews
in multiple languages should be aggregated and displayed. Speakers of different
languages may have consistently different experiences, e.g., different
information available in different languages at tourist attractions or
different user experiences with software due to
internationalization/localization choices. This paper assesses the similarity
in the ratings given by speakers of different languages to London tourist
attractions on TripAdvisor. The correlations between different languages are
generally high, but some language pairs are more correlated than others. The
results question the common practice of computing average ratings from reviews
in many languages.


title:
Is it "natural" to expect Economics to become a part of the Natural
  Sciences?

abstract:
  We are in the middle of a complex debate as to whether Economics is really a
proper natural science. The 'Discussion & Debate' issue of this Euro. Phys. J.
Special Topic volume is: 'Can economics be a Physical Science?' I discuss some
aspects here.


title: Electrically pumped single-defect light emitters in WSe$_2$

abstract:
  Recent developments in fabrication of van der Waals heterostructures enable
new type of devices assembled by stacking atomically thin layers of
two-dimensional materials. Using this approach, we fabricate light-emitting
devices based on a monolayer WSe$_2$, and also comprising boron nitride
tunnelling barriers and graphene electrodes, and observe sharp luminescence
spectra from individual defects in WSe$_2$ under both optical and electrical
excitation. This paves the way towards the realization of electrically-pumped
quantum emitters in atomically thin semiconductors. In addition we demonstrate
tuning by more than 1 meV of the emission energy of the defect luminescence by
applying a vertical electric field. This provides an estimate of the permanent
electric dipole created by the corresponding electron-hole pair. The
light-emitting devices investigated in our work can be assembled on a variety
of substrates enabling a route to integration of electrically pumped single
quantum emitters with existing technologies in nano-photonics and
optoelectronics.


title: An analogous Wu-Yang monopole in superfluid

abstract:
  By identifying the Schr\"{o}dinger equation with the hydrodynamic equations
in superfluid ${^3}$He, the effective potential is introduced in the
Schr\"{o}dinger equation to solve the quantum pressure in steady state. The
pure gauge velocity solutions of hydrodynamic equations provide an analogous
Wu-Yang monopole potential. The two cases of velocity in superfluid are
equivalent to the two regions of Wu-Yang monopole potential. Due to the
compressibility of superfluid, the physical models are limited, such as hard
core and harmonic oscillator. It is important that the constraint condition of
$\nabla\rho\cdot \textbf{v}=0$ plays a key role, which determines that the
integral quantum numbers are selected in monopole harmonics and shows the
special analogous Wu-Yang monopole. The results provide a new possibility for
the simulation of Wu-Yang monopole.


title:
UAV-based Autonomous Image Acquisition with Multi-View Stereo Quality
  Assurance by Confidence Prediction

abstract:
  In this paper we present an autonomous system for acquiring close-range
high-resolution images that maximize the quality of a later-on 3D
reconstruction with respect to coverage, ground resolution and 3D uncertainty.
In contrast to previous work, our system uses the already acquired images to
predict the confidence in the output of a dense multi-view stereo approach
without executing it. This confidence encodes the likelihood of a successful
reconstruction with respect to the observed scene and potential camera
constellations. Our prediction module runs in real-time and can be trained
without any externally recorded ground truth. We use the confidence prediction
for on-site quality assurance and for planning further views that are tailored
for a specific multi-view stereo approach with respect to the given scene. We
demonstrate the capabilities of our approach with an autonomous Unmanned Aerial
Vehicle (UAV) in a challenging outdoor scenario.


title:
A degenerate chemotaxis system with flux limitation: Maximally extended
  solutions and absence of gradient blow-up

abstract:
  This paper aims at providing a first step toward a qualitative theory for a
new class of chemotaxis models derived from the celebrated Keller-Segel system,
with the main novelty being that diffusion is nonlinear with flux delimiter
features. More precisely, as a prototypical representative of this class we
study radially symmetric solutions of the parabolic-elliptic system (see the
text).
  Under the initial condition $u|_{t=0}=u_0>0$ and no-flux boundary conditions
in balls $\Omega\subset\mathbb{R}^n$, where $\chi>0$ and
$\mu:=\frac{1}{|\Omega|} \int_\Omega u_0$.\abs
  The main results assert the existence of a unique classical solution,
extensible in time up to a maximal $T_{max} \in (0,\infty]$ which has the
property that $$\mbox{if} \quad T_{max}<\infty \quad \mbox{then}
\quad\limsup_{t\nearrow T_{max}} \|u(\cdot,t)\|_{L^\infty(\Omega)}=\infty.
\qquad \qquad (\star)$$
  The proof therefore is mainly based on comparison methods, which firstly
relate pointwise lower and upper bounds for the spatial gradient $u_r$ to
$L^\infty$ bounds for $u$ and to {\em upper bounds} for $z:=\frac{u_t}{u}$;
secondly, another comparison argument involving nonlocal nonlinearities
provides an appropriate control of $z_+$ in terms of bounds for $u$ and
$|u_r|$, with suitably mild dependence on the latter.
  As a consequence of ($\star$) by means of suitable a priori estimates it is
moreover shown that the above solutions are global and bounded when either
$$n\ge 2 \ \mbox{ and } \chi<1, \qquad \mbox{or} \qquad n=1, \ \chi>0 \ \mbox{
and } m<m_c, $$ with $m_c:=\frac{1}{\sqrt{\chi^2-1}}$ if $\chi>1$ and
$m_c:=\infty$ if $\chi\le 1$. That these conditions are essentially optimal
will be shown in a forthcoming paper in which ($\star$) will be used to derive
complementary results on the occurrence of solutions blowing up in finite time
with respect to the norm of $u$ in $L^\infty(\Omega)$.


title:
Summation formula inequalities for eigenvalues of Schr\"odinger
  operators

abstract:
  We derive inequalities for sums of eigenvalues of Schr\"{o}dinger operators
on finite intervals and tori. In the first of these cases, the inequalities
converge to the classical trace formulae in the limit as the number of
eigenvalues considered approaches infinity.


title:
Dynamical Scheme for Interferometric Measurements of Full-Counting
  Statistics

abstract:
  We propose a dynamical scheme for measuring the full counting statistics in a
mesoscopic conductor using an electronic Mach-Zehnder interferometer. The
conductor couples capacitively to one arm of the interferometer and causes a
phase shift which is proportional to the number of transferred charges.
Importantly, the full counting statistics can be obtained from average current
measurements at the outputs of the interferometer. The counting field can be
controlled by varying the time delay between two separate voltage signals
applied to the conductor and the interferometer, respectively. As a specific
application we consider measuring the entanglement entropy generated by
partitioning electrons on a quantum point contact. Our scheme is robust against
moderate environmental dephasing and can be realized thanks to recent advances
in giga-hertz quantum electronics.


title:
Bifurcations and exceptional points in a PT-symmetric dipolar
  Bose-Einstein condensate

abstract:
  We investigate the bifurcation structure of stationary states in a dipolar
Bose-Einstein condensate located in an external PT-symmetric potential. The
imaginary part of this external potential allows for the effective description
of in- and out-coupling of particles. To unveil the complete bifurcation
structure and the properties of the exceptional points we perform an analytical
continuation of the Gross-Pitaevskii equation, which is used to describe the
system. We use an elegant and numerically efficient method for the analytical
continuation of the Gross-Pitaevskii equation with dipolar interactions
containing bicomplex numbers. The Bose-Einstein condensate with dipole
interaction shows a much richer bifurcation scenario than a condensate without
long-range interactions. The inclusion of analytically continued states can
also explain property changes of bifurcation points which were hidden before,
and allows for the examination of the properties of the exceptional points
associated with the branch points. With the new analytically continued states
we are able to prove the existence of an exceptional point of fifth order.


title:
Summation formula inequalities for eigenvalues of the perturbed harmonic
  oscillator

abstract:
  We derive explicit inequalities for sums of eigenvalues of one-dimensional
Schr\"{o}dinger operators on the whole line. In the case of the perturbed
harmonic oscillator, these bounds converge to the corresponding trace formula
in the limit as the number of eigenvalues covers the whole spectrum.


title: Currents algebra for an atom-molecule Bose-Einstein condensate model

abstract:
  I present an interconversion currents algebra for an atom-molecule
Bose-Einstein condensate model and use it to get the quantum dynamics of the
currents. For different choices of the Hamiltonian parameters I get different
currents dynamics.


title:
Context Information Based Initial Cell Search for Millimeter Wave 5G
  Cellular Networks

abstract:
  Millimeter wave (mmWave) communication is envisioned as a cornerstone to
fulfill the data rate requirements for fifth generation (5G) cellular networks.
In mmWave communication, beamforming is considered as a key technology to
combat the high path-loss, and unlike in conventional microwave communication,
beamforming may be necessary even during initial access/cell search. Among the
proposed beamforming schemes for initial cell search, analog beamforming is a
power efficient approach but suffers from its inherent search delay during
initial access. In this work, we argue that analog beamforming can still be a
viable choice when context information about mmWave base stations (BS) is
available at the mobile station (MS). We then study how the performance of
analog beamforming degrades in case of angular errors in the available context
information. Finally, we present an analog beamforming receiver architecture
that uses multiple arrays of Phase Shifters and a single RF chain to combat the
effect of angular errors, showing that it can achieve the same performance as
hybrid beamforming.


title:
On some extensions to GA package: hybrid optimisation, parallelisation
  and islands evolution

abstract:
  Genetic algorithms are stochastic iterative algorithms in which a population
of individuals evolve by emulating the process of biological evolution and
natural selection. The R package GA provides a collection of general purpose
functions for optimisation using genetic algorithms. This paper describes some
enhancements recently introduced in version 3 of the package. In particular,
hybrid GAs have been implemented by including the option to perform local
searches during the evolution. This allows to combine the power of genetic
algorithms with the speed of a local optimiser. Another major improvement is
the provision of facilities for parallel computing. Parallelisation has been
implemented using both the master-slave approach and the islands evolution
model. Several examples of usage are presented, with both real-world data
examples and benchmark functions, showing that often high-quality solutions can
be obtained more efficiently.


title: Eisenhart lifts and symmetries of time-dependent systems

abstract:
  Certain dissipative systems, such as Caldirola and Kannai's damped simple
harmonic oscillator, may be modelled by time-dependent Lagrangian and hence
time dependent Hamiltonian systems with $n$ degrees of freedom. In this paper
we treat these systems, their projective and conformal symmetries as well as
their quantisation from the point of view of the Eisenhart lift to a Bargmann
spacetime in $n+2$ dimensions, equipped with its covariantly constant null
Killing vector field. Reparametrization of the time variable corresponds to
conformal rescalings of the Bargmann metric. We show how the Arnold map lifts
to Bargmann spacetime. We contrast the greater generality of the
Caldirola-Kannai approach with that of Arnold and Bateman. At the level of
quantum mechanics, we are able to show how the relevant Schr\"odinger equation
emerges naturally using the techniques of quantum field theory in curved
spacetimes, since a covariantly constant null Killing vector field gives rise
to well defined one particle Hilbert space. Time-dependent Lagrangians arise
naturally also in cosmology and give rise to the phenomenon of Hubble friction.
We provide an account of this for Friedmann-Lemaitre and Bianchi cosmologies
and how it fits in with our previous discussion in the non-relativistic limit.


title:
Conformal field theories from deformations of theories with $W_n$
  symmetry

abstract:
  We construct a set of non-rational conformal field theories that consist of
deformations of Toda field theory for sl(n). Besides conformal invariance, the
theories still enjoy a remnant infinite-dimensional affine symmetry. The case
n=3 is used to illustrate this phenomenon, together with further deformations
that yield enhanced Kac-Moody symmetry algebras. For generic n we compute
N-point correlation functions on the Riemann sphere and show that these can be
expressed in terms of sl(n) Toda field theory correlation functions.


title:
Small field inflation in ${\cal N}=1$ supergravity with a single chiral
  superfield

abstract:
  We consider "new inflation" inflationary models at small fields, embedded in
minimal ${\cal N}=1$ supergravity with a single chiral superfield. Imposing a
period of inflation compatible with experiment severely restricts possible
models, classified in perturbation theory. If moreover we impose that the field
goes to large values and very small potential at the current time, like would
be needed for instance for the inflaton being the volume modulus in large extra
dimensional scenarios, the possible models are restricted to very contrived
superpotentials.


abstract:
  We study the asymptotic Dirichlet problem for $f$-minimal graphs in
Cartan-Hadamard manifolds $M$. $f$-minimal hypersurfaces are natural
generalizations of self-shrinkers which play a crucial role in the study of
mean curvature flow. In the first part of this paper, we prove the existence of
$f$-minimal graphs with prescribed boundary behavior on a bounded domain
$\Omega \subset M$ under suitable assumptions on $f$ and the boundary of
$\Omega$. In the second part, we consider the asymptotic Dirichlet problem.
Provided that $f$ decays fast enough, we construct solutions to the problem.
Our assumption on the decay of $f$ is linked with the sectional curvatures of
$M$. In view of a result of Pigola, Rigoli and Setti, our results are almost
sharp.


title: Functional Choice and Non-significance Regions in Regression

abstract:
  Given data $y$ and $k$ covariates $x$ the problem is to decide which
covariates to include when approximating $y$ by a linear function of the
covariates. The decision is based on replacing subsets of the covariates by
i.i.d. normal random variables and comparing the error with that obtained by
retaining the subsets. If the two errors are not significantly different for a
particular subset it is concluded that the covariates in this subset are no
better than random noise and they are not included in the linear approximation
to $y$.


title: Constraints on 750 GeV colorless Q-onia from running couplings

abstract:
  We present yet another composite model explaining the relatively broad peak
in the diphoton invariant mass distribution around 750 GeV recently observed at
the LHC experiments. We consider the excess originates in bound states of
vector-like fermions Q transforming under the electroweak group (but not QCD)
of the standard model and which are also charged under a new SU(N_{TC})
QCD-like confining force. Since the new uncolored fields transform as SU(2)
doublets they can acquire a mass through Yukawa interactions with the
electroweak Higgs doublet, as quarks and leptons. We parametrize the Q-onium
bound state using the Coulomb approximation and give a numerical fit to the
diphoton excess consistent with no strong coupling effects up to about 30 TeV,
which is the energy scale for next generation colliders. The range of allowed
hypercharge Y_Q is given by 2.26 \leq Y_Q \leq 2.53 for N_{\rm TC} =2 and 2.17
\leq Y_Q \leq 2.31 for N_{\rm TC} = 3. The smoking gun for the model would be
the discovery of Q-onia decaying into Higgs and Z-boson.


title: The final spin from binary black holes in quasi-circular orbits

abstract:
  We revisit the problem of predicting the spin magnitude and direction of the
black hole resulting from the merger of two black holes with arbitrary masses
and spins inspiralling in quasi-circular orbits. We do this by analyzing a
catalog of 619 recent numerical-relativity simulations collected from the
literature and spanning a large variety of initial conditions. By combining
information from the post-Newtonian approximation, the extreme mass-ratio limit
and perturbative calculations, we improve our previously proposed
phenomenological formulae for the final remnant spin. In contrast with
alternative suggestions in the literature, and in analogy with our previous
expressions, the new formula is a simple algebraic function of the initial
system parameters and is not restricted to binaries with spins
aligned/anti-aligned with the orbital angular momentum, but can be employed for
fully generic binaries. The accuracy of the new expression is significantly
improved, especially for almost extremal progenitor spins and for small mass
ratios, yielding a root-mean-square error $\sigma\approx0.002$ for
aligned/anti-aligned binaries and $\sigma\approx0.006$ for generic binaries.
Our new formula is suitable for cosmological applications and can be employed
robustly in the analysis of the gravitational waveforms from advanced
interferometric detectors.


title: Energy Disaggregation for Real-Time Building Flexibility Detection

abstract:
  Energy is a limited resource which has to be managed wisely, taking into
account both supply-demand matching and capacity constraints in the
distribution grid. One aspect of the smart energy management at the building
level is given by the problem of real-time detection of flexible demand
available. In this paper we propose the use of energy disaggregation techniques
to perform this task. Firstly, we investigate the use of existing
classification methods to perform energy disaggregation. A comparison is
performed between four classifiers, namely Naive Bayes, k-Nearest Neighbors,
Support Vector Machine and AdaBoost. Secondly, we propose the use of Restricted
Boltzmann Machine to automatically perform feature extraction. The extracted
features are then used as inputs to the four classifiers and consequently shown
to improve their accuracy. The efficiency of our approach is demonstrated on a
real database consisting of detailed appliance-level measurements with high
temporal resolution, which has been used for energy disaggregation in previous
studies, namely the REDD. The results show robustness and good generalization
capabilities to newly presented buildings with at least 96% accuracy.


title:
On the Number of Reflexive and Shared Nearest Neighbor Pairs in
  One-Dimensional Uniform Data

abstract:
  For a random sample of points in $\mathbb{R}$, we consider the number of
pairs whose members are nearest neighbors (NN) to each other and the number of
pairs sharing a common NN. The first type of pairs are called reflexive NNs
whereas latter type of pairs are called shared NNs. In this article, we
consider the case where the random sample of size $n$ is from the uniform
distribution on an interval. We denote the number of reflexive NN pairs and the
number of shared NN pairs in the sample as $R_n$ and $Q_n$, respectively. We
derive the exact forms of the expected value and the variance for both $R_n$
and $Q_n$, and derive a recurrence relation for $R_n$ which may also be used to
compute the exact probability mass function of $R_n$. Our approach is a novel
method for finding the pmf of $R_n$ and agrees with the results in literature.
We also present SLLN and CLT results for both $R_n$ and $Q_n$ as $n$ goes to
infinity.


title: Partial DNA Assembly: A Rate-Distortion Perspective

abstract:
  Earlier formulations of the DNA assembly problem were all in the context of
perfect assembly; i.e., given a set of reads from a long genome sequence, is it
possible to perfectly reconstruct the original sequence? In practice, however,
it is very often the case that the read data is not sufficiently rich to permit
unambiguous reconstruction of the original sequence. While a natural
generalization of the perfect assembly formulation to these cases would be to
consider a rate-distortion framework, partial assemblies are usually
represented in terms of an assembly graph, making the definition of a
distortion measure challenging. In this work, we introduce a distortion
function for assembly graphs that can be understood as the logarithm of the
number of Eulerian cycles in the assembly graph, each of which correspond to a
candidate assembly that could have generated the observed reads. We also
introduce an algorithm for the construction of an assembly graph and analyze
its performance on real genomes.


title: Edge-covers in d-interval hypergraphs

abstract:
  A d-interval hypergraph has d disjoint copies of the unit interval as its
vertex set, and each edge is the union of d subintervals, one on each copy.
Extending a classical result of Gallai on the case d = 1, Tardos and Kaiser
used topological tools to bound the ratio between the transversal number and
the matching number in such hypergraphs. We take a dual point of view, and
bound the edge-covering number (namely the minimal number of edges covering the
entire vertex set) in terms of a parameter expressing independence of systems
of partitions of the d unit intervals. The main tool we use is an extension of
the KKM theorem to products of simplices, due to Peleg. Our approach also
yields a new proof of the Tardos-Kaiser result.


title: From Fock's Transformation to de Sitter Space

abstract:
  As in Deformed Special Relativity, we showed recently that the Fock
coordinate transformation can be derived from a new deformed Poisson brackets.
This approach allowed us to establish the corresponding momentum transformation
which keeps invariant the four dimensional contraction $p_{\mu} x^{\mu} $. From
the resulting deformed algebra, we construct in this paper the corresponding
first Casimir. After first quantization, we show by using the Klein-Gordon
equation that the spacetime of the Fock transformation is the de Sitter one. As
we will see, the invariant length representing the universe radius in the
spacetime of Fock's transformation is exactly the radius of the embedded
hypersurface representing the de Sitter spacetime.


title: SDNsec: Forwarding Accountability for the SDN Data Plane

abstract:
  SDN promises to make networks more flexible, programmable, and easier to
manage. Inherent security problems in SDN today, however, pose a threat to the
promised benefits. First, the network operator lacks tools to proactively
ensure that policies will be followed or to reactively inspect the behavior of
the network. Second, the distributed nature of state updates at the data plane
leads to inconsistent network behavior during reconfigurations. Third, the
large flow space makes the data plane susceptible to state exhaustion attacks.
  This paper presents SDNsec, an SDN security extension that provides
forwarding accountability for the SDN data plane. Forwarding rules are encoded
in the packet, ensuring consistent network behavior during reconfigurations and
limiting state exhaustion attacks due to table lookups. Symmetric-key
cryptography is used to protect the integrity of the forwarding rules and
enforce them at each switch. A complementary path validation mechanism allows
the controller to reactively examine the actual path taken by the packets.
Furthermore, we present mechanisms for secure link-failure recovery and
multicast/broadcast forwarding.


title:
The Gaia-ESO Survey: Inhibited extra mixing in two giants of the open
  cluster Trumpler 20?

abstract:
  We report the discovery of two Li-rich giants, with A(Li) ~ 1.50, in an
analysis of a sample of 40 giants of the open cluster Trumpler 20 (with turnoff
mass ~ 1.8 Msun). The cluster was observed in the context of the Gaia-ESO
Survey. The atmospheric parameters and Li abundances were derived using
high-resolution UVES spectra. The Li abundances were corrected for nonlocal
thermodynamical equilibrium (non-LTE) effects. Only upper limits of the Li
abundance could be determined for the majority of the sample. Two giants with
detected Li turned out to be Li rich: star MG 340 has A(Li) non-LTE = 1.54 \pm
0.21 dex and star MG 591 has A(Li) non-LTE = 1.60 \pm 0.21 dex. Star MG 340 is
on average ~ 0.30 dex more rich in Li than stars of similar temperature, while
for star MG 591 this difference is on average ~ 0.80 dex. Carbon and nitrogen
abundances indicate that all stars in the sample have completed the first
dredge-up. The Li abundances in this unique sample of 40 giants in one open
cluster clearly show that extra mixing is the norm in this mass range. Giants
with Li abundances in agreement with the predictions of standard models are the
exception. To explain the two Li-rich giants, we suggest that all events of
extra mixing have been inhibited. This includes rotation-induced mixing during
the main sequence and the extra mixing at the red giant branch luminosity bump.
Such inhibition has been suggested in the literature to occur because of fossil
magnetic fields in red giants that are descendants of main-sequence Ap-type
stars.


title:
A determination of mc(mc) from HERA data using a matched heavy-flavor
  scheme

abstract:
  The charm quark mass is one of the fundamental parameters of the Standard
Model Lagrangian. In this work we present a determination of the MSbar charm
mass from a fit to the inclusive and charm HERA deep-inelastic structure
function data. The analysis is performed within the xFitter framework, with
structure functions computed in the FONLL general-mass scheme as implemented in
APFEL. In the case of the FONLL-C scheme, we obtain mc(mc) = 1.335 +-
0.043(exp) +0.019 -0.000(param) +0.011 -0.008(mod) +0.033 -0.008(th) GeV. We
also perform an analogous determination in the fixed-flavor-number scheme at
next-to-leading order, finding mc(mc) = 1.318 +- 0.054(exp) +0.011
-0.010(param) +0.015 -0.019(mod) +0.045 -0.004(th) GeV, compatible with the
FONLL-C value. Our results are consistent with previous determinations from DIS
data as well as with the PDG world average.


title:
Resource allocation in OFDMA networks with half-duplex and imperfect
  full-duplex users

abstract:
  Recent studies indicate the feasibility of in-band fullduplex (FD) wireless
communications, where a wireless radio transmits and receives simultaneously in
the same band. Due to its potential to increase the capacity, analyzing the
performance of a cellular network that contains full-duplex devices is crucial.
In this paper, we consider maximizing the weighted sum-rate of downlink and
uplink of a single cell OFDMA network which consists of an imperfect FD
base-station (BS) and a mixture of half-duplex and imperfect full-duplex mobile
users. To this end, the joint problem of sub-channel assignment and power
allocation is investigated and a two-step solution is proposed. A heuristic
algorithm to allocate each sub-channel to a pair of downlink and uplink users
with polynomial complexity is presented. The power allocation problem is
convexified based on the difference of two concave functions approach, for
which an iterative solution is obtained. Simulation results demonstrate that
when all the users and the BS are perfect FD nodes the network throughput could
be doubled, Otherwise, the performance improvement is limited by the inter-node
interference and the self-interference. We also investigate the effect of the
self-interference cancellation capability and the percentage of FD users on the
network performance in both indoor and outdoor scenarios.


title: Tests of Sunspot Number Sequences: 2. Using Geomagnetic and Auroral Data

abstract:
  We compare four sunspot-number data sequences against geomagnetic and
terrestrial auroral observations. The comparisons are made for the original
SIDC composite of Wolf-Zurich-International sunspot number [$R_{ISNv1}$], the
group sunspot number [$R_{G}$] by Hoyt and Schatten (Solar Phys., 1998), the
new "backbone" group sunspot number [$R_{BB}$] by Svalgaard and Schatten (Solar
Phys., 2016), and the "corrected" sunspot number [$R_{C}$] by Lockwood at al.
(J.G.R., 2014). Each sunspot number is fitted with terrestrial observations, or
parameters derived from terrestrial observations to be linearly proportional to
sunspot number, over a 30-year calibration interval of 1982-2012. The fits are
then used to compute test sequences, which extend further back in time and
which are compared to $R_{ISNv1}$, $R_{G}$, $R_{BB}$, and $R_{C}$. To study the
long-term trends, comparisons are made using averages over whole solar cycles
(minimum-to-minimum). The test variations are generated in four ways: i) using
the IDV(1d) and IDV geomagnetic indices (for 1845-2013) fitted over the
calibration interval using the various sunspot numbers and the phase of the
solar cycle; ii) from the open solar flux (OSF) generated for 1845 - 2013 from
four pairings of geomagnetic indices by Lockwood et al. (Ann. Geophys., 2014)
and analysed using the OSF continuity model of Solanki at al. (Nature, 2000)
which employs a constant fractional OSF loss rate; iii) the same OSF data
analysed using the OSF continuity model of Owens and Lockwood (J.G.R., 2012) in
which the fractional loss rate varies with the tilt of the heliospheric current
sheet and hence with the phase of the solar cycle; iv) the occurrence frequency
of low-latitude aurora for 1780-1980 from the survey of Legrand and Simon (Ann.
Geophys., 1987). For all cases, $R_{BB}$ exceeds the test terrestrial series by
an amount that increases as one goes back in time.


title:
The wage transition in developed countries and its implications for
  China

abstract:
  The expression "wage transition" refers to the fact that over the past two or
three decades in all developed economies wage increases have levelled off.
There has been a widening divergence and decoupling between wages on the one
hand and GDP per capita on the other hand. Yet, in China wages and GDP per
capita climbed in sync (at least up to now). In the first part of the paper we
present comparative statistical evidence which measures the extent of the wage
transition effect. In a second part we consider the reasons of this phenomenon,
in particular we explain how the transfers of labor from low productivity
sectors (such as agriculture) to high productivity sectors (such as
manufacturing) are the driver of productivity growth, particularly through
their synergetic effects. Although rural flight represents only one of these
effects, it is certainly the most visible because of the geographical
relocation that it implies; it is also the most well-defined statistically.
Moreover, it will be seen that it is a good indicator of the overall
productivity and attractivity of the non-agricultural sector. Because this
model accounts fairly well for the observed evolution in industrialized
countries, we use it to predict the rate of Chinese economic growth in the
coming decades. Our forecast for the average annual growth of real wages ranges
from 4% to 6% depending on how well China will control the development of its
healthcare industry.


title: Automatic LQR Tuning Based on Gaussian Process Global Optimization

abstract:
  This paper proposes an automatic controller tuning framework based on linear
optimal control combined with Bayesian optimization. With this framework, an
initial set of controller gains is automatically improved according to a
pre-defined performance objective evaluated from experimental data. The
underlying Bayesian optimization algorithm is Entropy Search, which represents
the latent objective as a Gaussian process and constructs an explicit belief
over the location of the objective minimum. This is used to maximize the
information gain from each experimental evaluation. Thus, this framework shall
yield improved controllers with fewer evaluations compared to alternative
approaches. A seven-degree-of-freedom robot arm balancing an inverted pole is
used as the experimental demonstrator. Results of a two- and four-dimensional
tuning problems highlight the method's potential for automatic controller
tuning on robotic platforms.


title: Origin of Mass - Horizons Expanding from the Nambu's Theory

abstract:
  Origin of mass may be strong dynamics of matter in the vacuum. Since the
initial proposal of Nambu for the origin of the nucleon mass, the dynamical
symmetry breaking in the strongly coupled underlying theories has been
expanding the horizons in the context of the modern version of the origin of
mass beyond the Standard Model (SM). The Nambu-Jona-Lasinio (NJL) model is a
typical strong coupling theory with the non-zero critical coupling, in sharp
contrast to its precedent model, the Bardeen-Cooper-Schrieffer theory for the
superconductor. The non-zero critical coupling is also hidden in the
asymptotically free gauge theories including QCD and walking technicolor. As is
well known, the NJL model can be cast into the SM Higgs Lagrangian. We show
that the SM Higgs Lagrangian is simply rewritten into a form of the
(approximately) scale-invariant nonlinear sigma model, with both the chiral
symmetry and scale symmetry realized nonlinearly, with the SM Higgs being
nothing but the (pseudo-) dilaton. The SM Higgs Lagrangian is further gauge
equivalent to the scale-invariant Hidden Local Symmetry (HLS) Lagrangian,
s-HLS, having spin 1 bosons hidden in the SM. As the simplest possible
underlying theory for the SM Higgs Lagrangian we first discuss the top quark
condensate ("top-mode SM"), where the top-mode dilaton is the 125 GeV Higgs. We
then discuss the walking technicolor having near infrared conformality, whose
effective theory is the s-HLS model precisely the same as the SM Higgs
Lagrangian (with larger chiral symmetry), where the 125 GeV Higgs is
successfully identified with the techidilaton.


title: Pattern formation mechanisms in motility mutants of Myxococcus xanthus

abstract:
  Formation of spatial patterns of cells is a recurring theme in biology and
often depends on regulated cell motility. Motility of M. xanthus depends on two
motility machineries: the S-engine and A-engine. Moving M. xanthus cells can
organize into spreading colonies or spore-filled fruiting bodies depending on
their nutritional status. To understand these two pattern formation processes
and the contributions by the two motility machineries, as well as cell
reversal, we analyze spatial self-organization in 3 strains: i) a mutant that
moves unidirectionally without reversing by the A-motility system only, ii) a
unidirectional mutant that is also equipped with the S-motility system, and
iii) the wild-type that, in addition to the two motility systems, reverses its
direction of movement. The mutant moving by the A-engine illustrates that
collective motion in the form of large moving clusters can arise in gliding
bacteria due to steric interactions of the rod-shaped cells, without the need
of invoking any biochemical signal regulation. The two-engine strain mutant
reveals that the same phenomenon emerges when both motility systems are
present, and as long as cells exhibit unidirectional motion only. From the
study of these two strains, we conclude that unidirectional cell motion induces
the formation of large moving clusters at low and intermediate densities, while
it results into vortex formation at very high densities. These findings are
consistent with what is known from self-propelled rods which strongly suggests
that the combined effect of self-propulsion and volume exclusion interactions
is the pattern formation mechanism leading to the observed phenomena. In
addition, we learn that when cells reverse, as observed in the wild-type, cells
form small but strongly elongated clusters and self-organize into a mesh-like
structure at high enough densities.


title: Grassmannization of classical models

abstract:
  Applying Feynman diagrammatics to non-fermionic strongly correlated models
with local constraints might seem generically impossible for two separate
reasons: (i) the necessity to have a Gaussian (non-interacting) limit on top of
which the perturbative diagrammatic expansion is generated by Wick's theorem,
and (ii) the Dyson's collapse argument implying that the expansion in powers of
coupling constant is divergent. We show that for arbitrary classical lattice
models both problems can be solved/circumvented by reformulating the
high-temperature expansion (more generally, any discrete representation of the
model) in terms of Grassmann integrals. Discrete variables residing on either
links, plaquettes, or sites of the lattice are associated with the Grassmann
variables in such a way that the partition function (and correlations) of the
original system and its Grassmann-field counterpart are identical. The
expansion of the latter around its Gaussian point generates Feynman diagrams. A
proof-of-principle implementation is presented for the classical 2D Ising
model. Our work paves the way for studying lattice gauge theories by treating
bosonic and fermionic degrees of freedom on equal footing.

categories: cond-mat.stat-mech cond-mat.str-el hep-lat hep-th


title:
Observation estimate for kinetic transport equation by diffusion
  approximation

abstract:
  We study the unique continuation property for the neutron transport equation
and for a simplified model of the Fokker-Planck equation in a bounded domain
with absorbing boundary condition. An observation estimate is derived. It
depends on the smallness of the mean free path and the frequency of the
velocity average of the initial data. The proof relies on the well known
diffusion approximation under convenience scaling and on basic properties of
this diffusion. Eventually we propose a direct proof for the observation at one
time of parabolic equations. It is based on the analysis of the heat kernel.


title:
Variation in the pre-transit Balmer line signal around the hot Jupiter
  HD 189733 b

abstract:
  As followup to our recent detection of a pre-transit signal around HD 189733
b, we obtained full pre-transit phase coverage of a single planetary transit.
The pre-transit signal is again detected in the Balmer lines but with variable
strength and timing, suggesting that the bow shock geometry reported in our
previous work does not describe the signal from the latest transit. We also
demonstrate the use of the Ca II H and K residual core flux as a proxy for the
stellar activity level throughout the transit. A moderate trend is found
between the pre-transit absorption signal in the 2013 data and the Ca II H
flux. This suggests that some of the 2013 pre-transit hydrogen absorption can
be attributed to varying stellar activity levels. A very weak correlation is
found between the Ca II H core flux and the Balmer line absorption in the 2015
transit, hinting at a smaller contribution from stellar activity compared to
the 2013 transit. We simulate how varying stellar activity levels can produce
changes in the Balmer line transmission spectra. These simulations show that
the strength of the 2013 and 2015 pre-transit signals can be reproduced by
stellar variability. If the pre-transit signature is attributed to
circumplanetary material, its evolution in time can be described by accretion
clumps spiraling towards the star, although this interpretation has serious
limitations. Further high-cadence monitoring at H-alpha is necessary to
distinguish between true absorption by transiting material and short-term
variations in the stellar activity level.


title: Transformation of Communication Processes: Data Journalism

abstract:
  This article gives a brief review of the history of data journalism, as well
as the prerequisites for its appearance. The authors describe the advantages of
employing data-journalism skills in the newsrooms. Finally, the article
provides a review of data-driven journalism projects all over the world, state
of art 2014.


title:
Iron: A Key Element for Understanding the Origin and Evolution of
  Interstellar Dust

abstract:
  The origin and depletion of iron differ from all other abundant refractory
elements that make up the composition of the interstellar dust. Iron is
primarily synthesized in Type Ia supernovae (SNe Ia) and in core collapse
supernovae (CCSN), and is present in the outflows from AGB stars. Only the
latter two are observed to be sources of interstellar dust, since searches for
dust in SN~Ia have provided strong evidence for the absence of any significant
mass of dust in their ejecta. Consequently, more than 65% of the iron is
injected into the ISM in gaseous form. Yet, ultraviolet and X-ray observations
along many lines of sight in the ISM show that iron is severely depleted in the
gas phase compared to expected solar abundances. The missing iron, comprising
about 90% of the total, is believed to be locked up in interstellar dust. This
suggests that most of the missing iron must have precipitated from the ISM gas
by cold accretion onto preexisting silicate, carbon, or composite grains. Iron
is thus the only element that requires most of its growth to occur outside the
traditional stellar condensation sources. This is a robust statement that does
not depend on our evolving understanding of the dust destruction efficiency in
the ISM. Reconciling the physical, optical, and chemical properties of such
composite grains with their many observational manifestations is a major
challenge for understanding the nature and origin of interstellar dust.


title: Nakayama Automorphism and Rigidity of Dual Reflections Group Coactions

abstract:
  We study homological properties and rigidity of group coactions on
Artin-Schelter regular algebras.


title:
Point Island Models for Nucleation and Growth of Supported Nanoclusters
  during Surface Deposition

abstract:
  Point island models (PIMs) are presented for the formation of supported
nanoclusters (or islands) during deposition on flat crystalline substrates at
lower submonolayer coverages. These models treat islands as occupying a single
adsorption site, although carrying a label to track their size (i.e., they
suppress island structure). However, they are particularly effective in
describing the island size and spatial distributions. In fact, these PIMs
provide fundamental insight into the key features for homogeneous nucleation
and growth processes on surfaces. PIMs are also versatile being readily adapted
to treat both diffusion-limited and attachment-limited growth, and also a
variety of other nucleation processes with modified mechanisms. Their behavior
is readily and precisely assessed by kinetic Monte Carlo simulation.


title:
Polarization Enhancement of terahertz radiation generated by intrinsic
  Josephson junctions in a truncated edge square
  Bi_{2}Sr_{2}CaCu_{2}O_{8+{\delta}} mesa

abstract:
  In this study, we investigated the terahertz radiation from a truncated edge
square mesa structure made from a superconducting
Bi_{2}Sr_{2}CaCu_{2}O_{8+{\delta}} . Using a commercial software, the
polarization characteristics were determined, and introduced, while accounting
for the skin effect. The axial ratio was enhanced in the simulation by
performing a parametric study on the design.


title: 1/r potential in higher dimensions

abstract:
  In Einstein gravity, gravitational potential goes as $1/r^{d-3}$ in $d$
non-compactified spacetime dimensions, which assumes the familiar $1/r$ form in
four dimensions. On the other hand, it goes as $1/r^{\alpha}$, with
$\alpha=(d-2m-1)/m$, in pure Lovelock gravity involving only one $m$th order
term of the Lovelock polynomial in the gravitational action. The latter offers
a novel possibility of having $1/r$ potential for the non-compactified
dimension spectrum given by $d=3m+1$. Thus it turns out that in the two
prototype gravitational settings of isolated objects, like black holes and the
universe as a whole --- cosmological models, the Einstein gravity in four and
$m$th order pure Lovelock gravity in $3m+1$ dimensions behave in a similar
fashion as far as gravitational interactions are considered. However
propagation of gravitational waves (or the number of degrees of freedom) does
indeed serve as a discriminator because it has two polarizations only in four
dimensions.


title: Dual Hodge decompositions and derived Poisson brackets

abstract:
  We study general properties of Hodge-type decompositions of cyclic and
Hochschild homology of universal enveloping algebras of (DG) Lie algebras. Our
construction generalizes the operadic construction of cyclic homology of Lie
algebras due to Getzler and Kapranov. We give a topological interpretation of
such Lie Hodge decompositions in terms of $S^1$-equivariant homology of the
free loop space of a simply connected topological space. We prove that the
canonical derived Poisson structure on a universal enveloping algebra arising
from a cyclic pairing on the Koszul dual coalgebra preserves the Hodge
filtration on cyclic homology. As an application, we show that the
Chas-Sullivan Lie algebra of any simply connected closed manifold carries a
natural Hodge filtration. We conjecture that the Chas-Sullivan Lie algebra is
actually graded, i.e. the string topology bracket preserves the Hodge
decomposition.


title:
Global sausage oscillation of solar flare loops detected by the
  Interface Region Imaging Spectrograph

abstract:
  An observation from the Interface Region Imaging Spectrograph reveals
coherent oscillations in the loops of an M1.6 flare on 2015 March 12. Both the
intensity and Doppler shift of Fe~{\sc{xxi}}~1354.08\AA{}~show clear
oscillations with a period of $\sim$25 seconds. Remarkably similar oscillations
were also detected in the soft X-ray flux recorded by the Geostationary
Operational Environmental Satellites (GOES). With an estimated phase speed of
$\sim$2420~km~s$^{-1}$ and a derived electron density of at least
5.4$\times$10$^{10}$ cm$^{-3}$, the observed short-period oscillation is most
likely the global fast sausage mode of a hot flare loop. We find a phase shift
of $\sim$$\pi$/2 (1/4 period) between the Doppler shift oscillation and the
intensity/GOES oscillations, which is consistent with a recent forward modeling
study of the sausage mode. The observed oscillation requires a density contrast
between the flare loop and coronal background of a factor $\geqslant$42. The
estimated phase speed of the global mode provides an lower limit of the
Alfv\'en speed outside the flare loop. We also find an increase of the
oscillation period, which might be caused by the separation of the loop
footpoints with time.


title:
An Exact Convex Formulation of Optimal Power Flow in Radial Distribution
  Networks Including Transverse Components

abstract:
  The recent literature has discussed the use of the relaxed Second Order Cone
Programming (SOCP) to formulate Optimal Power Flow problems (OPF) for radial
power grids. However, if the shunt parameters of the lines, composing the power
grid, are considered the proposed methods do not provide sufficient conditions
that can be verified ex ante for the exactness of the optimal solutions.
Additionally, the same formulations have not correctly accounted for the
ampacity constraint of the lines. Similar to the inclusion of upper
voltage-magnitude limit, the SOCP relaxation faces difficulties when the
ampacity constraints of the lines are binding. In order to overcome these
limitations, we propose a convex formulation of the OPF problem applied to
radial power grids for which the AC-OPF equations, including the transverse
parameters, are considered. We augment the formulation with a new set of more
conservative constraints to limit the lines current together with the nodal
voltage-magnitudes. Sufficient conditions are provided to ensure the
feasibility and optimality of the proposed OPF solution. Furthermore, the
proofs of the exactness of the SOCP relaxation are provided. Using standard
power grids, we show that these conditions are mild and hold for real
distribution networks.


title: An anomaly in space and time and the origin of dynamics

abstract:
  The Hamiltonian defines the dynamical properties of the universe. Evidence
from particle physics shows that there is a different version of the
Hamiltonian for each direction of time. As there is no physical basis for the
universe to be asymmetric in time, both versions must operate equally. However,
conventional physical theories accommodate only one version of the Hamiltonian
and one direction of time. This represents an unexplained anomaly in
conventional physics and calls for a reworking of the concepts of time and
space. Here I explain how the anomaly can be resolved by allowing dynamics to
emerge phenomenologically. The resolution offers a picture of time and space
that lies below our everyday experience, and one in which their differences are
epiphenomenal rather than elemental.


title: A New approach to the construction of braided T-categories

abstract:
  The aim of this paper is to construct a new braided $T$-category via the
generalized Yetter-Drinfel'd modules and Drinfel'd codouble over Hopf algebra,
an approach different from that proposed by Panaite and Staic \cite{PS}.
Moreover, in the case of finite dimensional, we will show that this category
coincides with the corepresentation of a certain coquasitriangular Turaev group
algebra that we construct. Finally we apply our theory to the case of group
algebra.


title: Configurational entropy as a bounding of Gauss-Bonnet braneworld models

abstract:
  Configurational entropy has been revealed as a reliable method for
constraining some parameters of a given model [Phys. Rev. D \textbf{92} (2015)
126005, Eur. Phys. J. C \textbf{76} (2016) 100]. In this letter we calculate
the configurational entropy in Gauss-Bonnet braneworld models. Our results
restrict the range of acceptability of the Gauss-Bonnet scalar values. In this
way, the information theoretical measure in Gauss-Bonnet scenarios opens a new
window to probe situations where the additional parameters, responsible for the
Gauss-Bonnet sector, are arbitrary. We also show that such an approach is very
important in applications that include p and Dp-branes and various
superstring-motivated theories.


title: Projective Modules over Quantum Projective Line

abstract:
  Taking a groupoid C*-algebra approach to the study of the quantum complex
projective spaces $\mathbb{P}^{n}\left( \mathcal{T}\right) $ constructed from
the multipullback quantum spheres introduced by Hajac and collaborators, we
analyze the structure of the C*-algebra $C\left( \mathbb{P}^{1}\left(
\mathcal{T}\right) \right) $ realized as a concrete groupoid C*-algebra, and
find its $K$-groups. Furthermore after a complete classification of the unitary
equivalence classes of projections or equivalently the isomorphism classes of
finitely generated projective modules over the C*-algebra $C\left(
\mathbb{P}^{1}\left( \mathcal{T}\right) \right) $, we identify those quantum
principal $U\left( 1\right) $-bundles introduced by Hajac and collaborators
among the projections classified.


title: Szlenk and $w^*$-dentability indices of $C(K)$

abstract:
  Given any compact, Hausdorff space $K$ and $1<p<\infty$, we compute the
Szlenk and $w^*$-dentability indices of the spaces $C(K)$ and $L_p(C(K))$. We
show that if $K$ is compact, Hausdorff, scattered, $CB(K)$ is the
Cantor-Bendixson index of $K$, and $\xi$ is the minimum ordinal such that
$CB(K)\leqslant \omega^\xi$, then $Sz(C(K))=\omega^\xi$ and
$Dz(C(K))=Sz(L_p(C(K)))= \omega^{1+\xi}.$


title: Pseudo Principal Pivot Transform: The Group Inverse Case

abstract:
  In this short note, we prove a formula for the group inverse of a block
matrix and consider the pseudo principal pivot transform expressed in terms of
group inverses. Extensions of the usual principal pivot transform, where the
usual inverse is replaced by the Moore-Penrose inverse, were considered in the
literature. The objective here is to derive the corresponding formulae for the
group generalized inverse. These are expected to be useful in our future work.


title:
An Adaptive Partial Linearization Method for Optimization Problems on
  Product Sets

abstract:
  We suggest an adaptive version of a partial linearization method for
composite optimization problems. The goal function is the sum of a smooth
function and a non necessary smooth convex separable function, whereas the
feasible set is the corresponding Cartesian product. The method consists in
selective component-wise steps together with a special control of a tolerance
sequence. This technique is destined to reduce the computational expenses per
iteration and maintain the basic convergence properties. We also establish its
convergence rates and describe some examples of applications. Preliminary
results of computations illustrate usefulness of the new method.


title:
Light-Matter Interactions in Two-Dimensional Transition Metal
  Dichalcogenides: Dominant Excitonic Transitions in mono- and few-layer
  MoX$_2$ and Band Nesting

abstract:
  We report ab initio calculations of the dielectric function of six mono- and
bilayer molybdenum dichalcogenides based in a Bethe Salpether
equation+G$_0$W$_0$ ansatz, focussing on the excitonic transitions dominating
the absorption spectrum up to an excitation energy of 3\,eV. Our calculations
suggest that switching chalcogen atoms and the strength of interlayer
interactions should affect the detailed composition of the high 'C' peaks in
experimental optical spectra of molybdenum dichalcogenides and cause a
significant spin-orbit-splitting of the contributing excitonic transitions in
monolayer MoSe$_2$ and MoTe$_2$. This can be explained through changes in the
electronic dispersion around the Fermi energy along the chalcogen series
S$\rightarrow$Se$\rightarrow$Te that move the van-Hove singularities in the
density of states of the two-dimensional materials along the
\textit{$\Gamma$}-\textit{K} line in the Brillouin zone. Further, we confirm
the distinct interlayer character of the '\textsl{C}' peak transition in
few-layer MoS$_2$ that was predicted before from experimental data and show
that a similar behaviour can be expected for MoSe$_2$ and MoTe$_2$ as well.


title:
Random patterns in fish schooling enhance alertness: a hydrodynamic
  perspective

abstract:
  One of the most highly debated questions in the field of animal swarming and
social behaviour, is the collective random patterns and chaotic behaviour
formed by some animal species, in particular if there is a danger. Is such a
behaviour beneficial or unfavourable for survival? Here we report on one of the
most remarkable forms of animal swarming and social behaviour - fish schooling
- from a hydrodynamic point of view. We found that some fish species do not
have preferred orientation and they swarm in a random pattern mode, despite the
excess of energy consumed. Our analyses, which includes calculations of the
hydrodynamic forces between slender bodies, show that such a behaviour enhances
the transfer of hydrodynamic information, and thus enhances the survivability
of the school. These findings support the general hypothesis that a disordered
and non-trivial collective behaviour of individuals within a nonlinear
dynamical system is essential for optimising transfer of information - an
optimisation that might be crucial for survival.


title:
Convergence of transition amplitudes obtained with the Schwinger
  variational principle

abstract:
  An exactly solvable time-dependent quantum mechanical problem is employed to
study the convergence properties of transition amplitudes calculated by using
the Schwinger variational principle. A detailed comparison between the
amplitudes approximated by the perturbative series and by their associated
Schwinger variational principles is performed. The much better performance
obtained by the variational principle is documented through different case
studies. For a given order of the Schwinger principle, it is observed that the
transition amplitudes do not converge to the exact one for large perturbations.
The latter is true even though large combinations of unperturbed states with
constant coefficients are taken as trial wave functions. As a matter of fact,
it is shown that the improvement of the method comes from using better trial
wave functions and increasing the order of the Schwinger principle employed.


title: Real-space Hopfield diagonalization of inhomogeneous dispersive media

abstract:
  We introduce a real-space technique able to extend the standard Hopfield
approach commonly used in quantum polaritonics to the case of inhomogeneous
lossless materials interacting with the electromagnetic field. We derive the
creation and annihilation polaritonic operators for the system normal modes as
linear, space-dependent superpositions of the microscopic light and matter
fields, and we invert the Hopfield transformation expressing the microscopic
fields as functions of the polaritonic operators. As an example, we apply our
approach to the case of a planar interface between vacuum and a polar
dielectric, showing how we can consistently treat both propagative and surface
modes, and express their nonlinear interactions, arising from phonon
anharmonicity, as polaritonic scattering terms. We also show that our theory
can be naturally extended to the case of dissipative materials.


title:
The Accounting Network: how financial institutions react to systemic
  crisis

abstract:
  The role of Network Theory in the study of the financial crisis has been
widely spotted in the latest years. It has been shown how the network topology
and the dynamics running on top of it can trigger the outbreak of large
systemic crisis. Following this methodological perspective we introduce here
the Accounting Network, i.e. the network we can extract through vector
similarities techniques from companies' financial statements. We build the
Accounting Network on a large database of worldwide banks in the period
2001-2013, covering the onset of the global financial crisis of mid-2007. After
a careful data cleaning, we apply a quality check in the construction of the
network, introducing a parameter (the Quality Ratio) capable of trading off the
size of the sample (coverage) and the representativeness of the financial
statements (accuracy). We compute several basic network statistics and check,
with the Louvain community detection algorithm, for emerging communities of
banks. Remarkably enough sensible regional aggregations show up with the
Japanese and the US clusters dominating the community structure, although the
presence of a geographically mixed community points to a gradual convergence of
banks into similar supranational practices. Finally, a Principal Component
Analysis procedure reveals the main economic components that influence
communities' heterogeneity. Even using the most basic vector similarity
hypotheses on the composition of the financial statements, the signature of the
financial crisis clearly arises across the years around 2008. We finally
discuss how the Accounting Networks can be improved to reflect the best
practices in the financial statement analysis.