title:
Chemotaxis and auto-chemotaxis of self-propelling artificial droplet
  swimmers

abstract:
  Chemotaxis and auto-chemotaxis play an important role in many essential
biological processes. We present a self-propelling artificial swimmer system
which exhibits chemotaxis as well as negative auto-chemotaxis. Oil droplets in
an aqueous surfactant solution are driven by interfacial Marangoni flows
induced by micellar solubilization of the oil phase. We demonstrate that
chemotaxis along micellar surfactant gradients can guide these swimmers through
a microfluidic maze. Similarly, a depletion of empty micelles in the wake of a
droplet swimmer causes negative autochemotaxis and thereby trail avoidance. We
have studied autochemotaxis quantitatively in a microfluidic device of
bifurcating channels: Branch choices of consecutive swimmers are
anticorrelated, an effect decaying over time due to trail dispersion. We have
modeled this process by a simple one-dimensional diffusion process and
stochastic Langevin dynamics. Our results are consistent with a linear
surfactant gradient force and diffusion constants appropriate for micellar
diffusion, and provide a measure of autochemotactic feedback strength versus
stochastic forces.


title: Casimir effect for Elko fields

abstract:
  The Casimir effect for {mass dimension one fermion fields (sometimes called
Elko)} in $3+1$ dimension is obtained using Dirichlet boundary conditions. It
is shown the existence of a repulsive force four times greater than the case of
the scalar field. The precise reason for such differences are highlighted and
interpreted, as well as the right parallel of the Casimir effect due to scalar
and fermionic fields.


title:
New applications of the Lambert and generalized Lambert functions to
  ferromagnetism and quantum mechanics

abstract:
  The applications of the recent results obtained in the theory of generalized
Lambert functions, to the mean field theory of ferromagnetism are presented. As
a consequence, all the predictions of the Weiss theory of ferromagnetism can be
explicitly and exactly formulated. In several quantum mechanical problems
involving delta function potentials, the solutions of the transcendental
eigenvalue equations are expressed in terms of two parameters generalized
Lambert functions. Some others, till unnoticed examples of eigenvalue equations
whose solutions can be written using the Lambert W function, are also
presented.


title:
The Einstein@Home Gamma-ray Pulsar Survey. I. Search Methods,
  Sensitivity and Discovery of New Young Gamma-ray Pulsars

abstract:
  We report on the results of a recent blind search survey for gamma-ray
pulsars in Fermi Large Area Telescope (LAT) data being carried out on the
distributed volunteer computing system, Einstein@Home. The survey has searched
for pulsations in 118 unidentified pulsar-like sources, requiring about 10,000
years of CPU core time. In total, this survey has resulted in the discovery of
17 new gamma-ray pulsars, of which 13 are newly reported in this work, and an
accompanying paper. These pulsars are all young, isolated pulsars with
characteristic ages between 12 kyr and 2 Myr, and spin-down powers between
$10^{34}$ and $4\times10^{36}$ erg/s. Two of these are the slowest spinning
gamma-ray pulsars yet known. One pulsar experienced a very large glitch $\Delta
f/f \approx 3.5\times10^{-6}$ during the Fermi mission. In this, the first of
two associated papers, we describe the search scheme used in this survey, and
estimate the sensitivity of our search to pulsations in unidentified Fermi-LAT
sources. One such estimate results in an upper limit of 57% for the fraction of
pulsed emission from the gamma-ray source associated with the Cas A supernova
remnant, constraining the pulsed gamma-ray photon flux that can be produced by
the neutron star at its center. We also present the results of precise timing
analyses for each of the newly detected pulsars.


title: Differential and integral forms on non-commutative algebras

abstract:
  An extended summary of the lecture course given at the V School on Geometry
and Physics, Bia\l owe\.za 2016, in which an algebraic approach to
differentiation and integration that is characteristic for non-commutative
geometry is described.


title: Solving the Persistent Phylogeny Problem in polynomial time

abstract:
  The notion of a Persistent Phylogeny generalizes the well-known Perfect
phylogeny model that has been thoroughly investigated and is used to explain a
wide range of evolutionary phenomena. More precisely, while the Perfect
Phylogeny model allows each character to be acquired once in the entire
evolutionary history while character losses are not allowed, the Persistent
Phylogeny model allows each character to be both acquired and lost exactly once
in the evolutionary history. The Persistent Phylogeny Problem (PPP) is the
problem of reconstructing a Persistent phylogeny tree, if it exists, from a
binary matrix where the rows represent the species (or the individuals) studied
and the columns represent the characters that each species can have.
  While the Perfect Phylogeny has a linear-time algorithm, the computational
complexity of PPP has been posed, albeit in an equivalent formulation, 20 years
ago. We settle the question by providing a polynomial time algorithm for the
Persistent Phylogeny problem.


title:
SU(5) Grand Unified Theory, its Polytopes and 5-fold Symmetric Aperiodic
  Tiling

abstract:
  We associate the lepton-quark families with the vertices of the 4D polytopes
5-cell and the rectified 5-cell derived from the SU(5) Coxeter-Dynkin diagram.
The off-diagonal gauge bosons are associated with the root poytope (1000)A4
whose facets are tetrahedra and the triangular prisms. The edge-vertex
relations are interpreted as the SU(5) charge conservation. The Dynkin diagram
symmetry of the SU(5) diagram can be interpreted as a kind of
particle-antiparticle symmetry. The Voronoi cell of the root lattice consists
of the union of the polytopes (1000)A4 + (0100)A4 + (0010)A4 + (0001)A4 whose
facets are 20 rhombohedra. We construct the Delone (Delaunay) cells of the root
lattice as the alternating 5-cell and the rectified 5-cell, a kind of dual to
the Voronoi cell. The vertices of the Delone cells closest to the origin
consists of the root vectors representing the gauge bosons. The faces of the
rhombohedra project onto the Coxeter plane as thick and thin rhombs leading to
Penrose-like tiling of the plane which can be used for the description of the
5-fold symmetric quasicrystallography. The model can be extended to SO(10) and
even to SO(11) by noting the Coxeter-Dynkin diagram embedding in A4 in D5 in
B5. Another embedding can be made through the relation A4 in D5 in E6 for more
popular GUT's.


title:
Physical quantities and spatial parameters in the complex octonion
  curved space

abstract:
  The paper focuses on finding out several physical quantities to exert an
influence on the spatial parameters of complex-octonion curved space, including
the metric coefficient, connection coefficient, and curvature tensor. In the
flat space described with the complex octonions, the radius vector is combined
with the integrating function of field potential to become a composite radius
vector. And the latter can be considered as the radius vector in a flat
composite-space (a function space). Further it is able to deduce some formulae
between the physical quantity and spatial parameter, in the complex-octonion
curved composite-space. Under the condition of weak field approximation, these
formulae infer a few results accordant with the General Theory of Relativity.
The study reveals that it is capable of ascertaining which physical quantities
are able to result in the warping of space, in terms of the curved
composite-space described with the complex octonions. Moreover, the method may
be expanded into some curved function spaces, seeking out more possible
physical quantities to impact the bending degree of curved spaces.


title: Relative Szeg\H{o} asymptotics for Toeplitz determinants

abstract:
  We study the asymptotic behavior, as $n\to\infty$, of ratios of Toeplitz
determinants $D_n(e^h d\mu)/D_n(d\mu)$ defined by a measure $\mu$ on the unit
circle and a sufficiently smooth function $h$. The approach we follow is based
on the theory of orthogonal polynomials. We prove that the second order
asymptotics depends on $h$ and only a few Verblunsky coefficients associated to
$\mu$. As a result, we establish a relative version of the Strong Szeg\H{o}
Limit Theorem for a wide class of measures $\mu$ with essential support on a
single arc. In particular, this allows the measure to have a singular component
within or outside of the arc.


title: One-loop pseudo-Goldstone masses in the minimal $SO(10)$ Higgs model

abstract:
  We calculate the prominent perturbative contributions shaping the one-loop
scalar spectrum of the minimal non-supersymmetric renormalizable $SO(10)$ Higgs
model whose unified gauge symmetry is spontaneously broken by an adjoint
scalar. Focusing on its potentially realistic $45\oplus 126$ variant in which
the rank is reduced by a VEV of the 5-index self-dual antisymmetric tensor, we
provide a thorough analysis of the corresponding one-loop Coleman-Weinberg
potential, paying particular attention to the masses of the potentially
tachyonic pseudo-Goldstone bosons (PGBs) transforming as $(8,1,0)$ and
$(1,3,0)$ under the Standard Model gauge group. The results confirm the assumed
existence of extended regions in the parameter space supporting a locally
stable SM-like quantum vacuum inaccessible at the tree-level. The effective
potential (EP) tedium is compared to that encountered in the previously studied
$45\oplus 16$ $SO(10)$ Higgs model where the polynomial corrections to the
relevant pseudo-Goldstone masses turn out to be easily calculable within a very
simplified purely diagrammatic approach.


title:
Dualization of non-abelian lattice gauge theory with Abelian Color
  Cycles (ACC)

abstract:
  We discuss a new approach to strong coupling expansion and dual
representations for non-abelian lattice gauge theories. The Wilson gauge action
is decomposed into a sum over "abelian color cycles" (ACC), which are loops
around plaquettes visiting different colors at the corners. ACCs are complex
numbers and thus commute such that a dual representation of a non-abelian
theory can be obtained as in the abelian case. We apply the ACC approach to
SU(2) and SU(3) lattice gauge theory and exactly rewrite the two partition sums
in a strong coupling series where all gauge integrals are known in closed form.


title: FLRW viscous cosmological models

abstract:
  In this paper we solve Friedmann equations by considering a universal media
as a non-perfect fluid with bulk viscosity and is described by a general "gamma
law" equation of state of the form $p= (\gamma -1) \rho + \Lambda(t)$, where
the adiabatic parameter $\gamma$ varies with scale factor $R$ of the metric and
$\Lambda$ is the time dependent cosmological constant. A unified description of
the early evolution of the universe is presented by assuming the bulk viscosity
and cosmological parameter in a linear combination of two terms of the form:
$\Lambda(t)=\Lambda_{0} + \Lambda_{1}\frac{\dot{R}}{R}$ and $\zeta = \zeta_{0}
+ \zeta_{1} \frac{\dot{R}}{R}$, where $\Lambda_{0},\;\Lambda_{1},\, \zeta_{0}$
and $ \zeta_{1}$ are constants, in which an inflationary phase is followed by
the radiation dominated phase. For this general gamma law equation of state, an
entirely integrable dynamical equation to the scale factor $R$ is obtained
along with its exact solutions. In this framework we demonstrate that the model
can be used to explain the dark energy dominant universe and for a special
choice of the parameters we can explain the accelerating expansion of the
universe also for two different phases, viz. combination of dark energy and
dark matter phase as well as unified dark energy phase. A special physical
check has been performed through sound speed constraint to validate the model.
At last we obtain a scaling relation between the Hubble parameter with
redshift.


title: Modeling Website Visits

abstract:
  We propose a multivariate model for the number of hits on a set of popular
websites, and show it to accurately reflect the behavior recorded in a data set
of Internet users in the United States. We assume that the random vector of
visits is distributed according to a censored multivariate normal with
marginals transformed to be discrete Pareto IV and, following the ideas of
Gaussian graphical models, we enforce sparsity on the inverse covariance matrix
to reduce dimensionality and to visualize the dependence structure as a graph.
The model allows for an easy inclusion of covariates and is useful for
comprehending the behavior of Internet users as a function of their age and
gender.


title:
Three-dimensional simulations of sound propagation in a trumpet with
  accurate mouthpiece shank geometry

abstract:
  The length and bore geometry of musical instruments directly influences the
quality of sound that can be produced. In brass instruments, nonlinear effects
from finite-amplitude wave propagation can lead to wave distortion giving
sounds a brassy timbre [3, 5, 14, 20, 26]. In this paper, we propose a
three-dimensional model to describe nonlinear wave propagation in a trumpet and
investigate the importance of the mouthpiece shank geometry. Time pressure
waveforms corresponding to B_3(b) and B_4(b) notes were recorded at the
mouthpiece shank and used as inputs for our model. To describe the motion of
compressible inviscid fluid, we numerically solved the compressible Euler
equations using the discontinuous Galerkin method. To validate our approach,
the numerical results were compared to the recorded musical notes outside the
bell of the trumpet. Simulations were performed on computational trumpets where
different bore geometries were considered. Our results demonstrate that the
shape of the narrow region near mouthpiece greatly influences the wave
propagation and accuracy of the trumpet model.


title: Compact Extra Dimensions in Quantum Mechanics

abstract:
  Extra-dimensions are a common topic in popular descriptions of theoretical
physics with which undergraduate student most often have no contact in physics
courses. This paper shows how students could be introduced to this topic by
presenting an approach to two basic consequences of the presence of compact
extra-dimensions based on undergraduate-level physics. The insensibility of
low-energy physics to compact extra dimensions is illustrated in the context of
non-relativistic quantum mechanics and the prediction of Kaluza-Klein
excitations of particles is discussed in the framework of relativistic
wave-equations. An exercise that could be used as a follow-up to the "particle
in a box" is proposed.


title:
Controlling the conductance of molecular junctions using proton transfer
  reactions: A theoretical model study

abstract:
  The influence of an intramolecular proton transfer reaction on the
conductance of a molecular junction is investigated employing a generic model,
which includes the effects of the electric field of the gate and leads
electrodes and the coupling to a dissipative environment. Using a quantum
master equation approach it is shown that, depending on the localization of the
proton, the junction exhibits a high or low current state, which can be
controlled by external electric fields. Considering different regimes, which
range from weak to strong hydrogen bonds in the proton transfer complex and
comprise situations with high and low barriers, necessary preconditions to
achieve control are analyzed. The results show that systems with a weak
hydrogen bond and a significant energy barrier for the proton transfer can be
used as molecular transistors or diodes.


title: Prediction of quantum many-body chaos in protactinium atom

abstract:
  Energy level spectrum of protactinium atom (Pa, Z=91) is simulated with a CI
calculation. Levels belonging to the separate manifolds of a given total
angular momentum and parity $J^\pi$ exhibit distinct properties of many-body
quantum chaos. Moreover, an extremely strong enhancement of small perturbations
takes place. As an example, effective three-electron interaction is
investigated and found to play a significant role in the system. Chaotic
properties of the eigenstates allow one to develop a statistical theory and
predict probabilities of different processes in chaotic systems.


title: On the Sum of Linear Coefficients of a Boolean Valued Function

abstract:
  Let $f:\{-1,1\}^{n}\rightarrow \{-1,1\}$ be a Boolean valued function having
total degree $d$. Then a conjecture due to Servedio and Gopalan asserts that
$\sum_{i=1}^{n}\widehat{f}(i)\leq \sum_{j=1}^{d}\widehat{\text{Maj}}_{d}(j)$
where $\text{Maj}_{d}$ is the majority function on $d$ bits. Here we give some
alternative formalisms of this conjecture involving the discrete derivative
operators on $f$.


title: Sparse Support Recovery with Non-smooth Loss Functions

abstract:
  In this paper, we study the support recovery guarantees of underdetermined
sparse regression using the $\ell_1$-norm as a regularizer and a non-smooth
loss function for data fidelity. More precisely, we focus in detail on the
cases of $\ell_1$ and $\ell_\infty$ losses, and contrast them with the usual
$\ell_2$ loss. While these losses are routinely used to account for either
sparse ($\ell_1$ loss) or uniform ($\ell_\infty$ loss) noise models, a
theoretical analysis of their performance is still lacking. In this article, we
extend the existing theory from the smooth $\ell_2$ case to these non-smooth
cases. We derive a sharp condition which ensures that the support of the vector
to recover is stable to small additive noise in the observations, as long as
the loss constraint size is tuned proportionally to the noise level. A
distinctive feature of our theory is that it also explains what happens when
the support is unstable. While the support is not stable anymore, we identify
an "extended support" and show that this extended support is stable to small
additive noise. To exemplify the usefulness of our theory, we give a detailed
numerical analysis of the support stability/instability of compressed sensing
recovery with these different losses. This highlights different parameter
regimes, ranging from total support stability to progressively increasing
support instability.


title:
Determining the dominant partial wave contributions from angular
  distributions of single- and double-polarization observables in pseudoscalar
  meson photoproduction

abstract:
  This work presents a simple method to determine the significant partial wave
contributions to experimentally determined observables in pseudoscalar meson
photoproduction. First, fits to angular distributions are presented and the
maximum orbital angular momentum $\text{L}_{\mathrm{max}}$ needed to achieve a
good fit is determined. Then, recent polarization measurements for $\gamma p
\rightarrow \pi^{0} p$ from ELSA, GRAAL, JLab and MAMI are investigated
according to the proposed method. This method allows us to project high-spin
partial wave contributions to any observable as long as the measurement has the
necessary statistical accuracy. We show, that high precision and large angular
coverage in the polarization data are needed in order to be sensitive to
high-spin resonance-states and thereby also for the finding of small resonance
contributions. This task can be achieved via interference of these resonances
with the well-known states. For the channel $\gamma p \rightarrow \pi^{0} p$,
those are the $N(1680)\frac{5}{2}^{+}$ and $\Delta(1950)\frac{7}{2}^{+}$,
contributing to the $F$-waves.


title:
Drive Mode Optimization and Path Planning for Plug-in Hybrid Electric
  Vehicles

abstract:
  Drive modes are driver-selectable pre-set configurations of powertrain and
certain vehicle parameters. Plug-in hybrid electric vehicles (PHEVs) typically
feature special options of drive modes that can affect the hybrid energy source
management system, for example, electric vehicle (EV) mode (that draws fully on
battery) and charge sustaining (CS) mode (that utilizes internal combustion
engine to charge battery while propelling the vehicle). This paper studies an
optimization problem to enable the driver to select the appropriate drive modes
for fuel minimization. We develop optimization algorithms that optimize the
decisions of drive modes based on trip information, and integrated with path
planning to find an optimal path, considering intermediate filling and charging
stations. We further provide an online algorithm that is based on the revealed
trip information. We evaluate our algorithms empirically on a Chevrolet Volt,
which shows significant fuel savings.


title: Atomic orbital self-energy and electronegativity

abstract:
  In this work, atomic calculations were performed within the local-density and
generalized-gradient approximations of exchange and correlation density
functionals within density-functional theory to provide accurate periodic
trends of first ionization energies and electron affinities of the atomic
series from hydrogen to xenon. Electronegativities were determined directly
from Mulliken's formula and were shown to be equivalently calculated rather by
using Slater-Janak's transition state or by calculating the electrostatic
self-energies of the orbitals involved in the transition to ions. Finally,
comparisons were made with other theoretical and experimental results,
including Mulliken-Jaff\'e's electronegativity scale.


title: DDalphaAMG for Twisted Mass Fermions

abstract:
  We present the Adaptive Aggregation-based Domain Decomposition Multigrid
method extended to the twisted mass fermion discretization action. We show
comparisons of results as a function of tuning the parameters that enter the
twisted mass version of the DDalphaAMG library
(https://github.com/sbacchio/DDalphaAMG). Moreover, we linked the DDalphaAMG
library to the tmLQCD software package and give details on the performance of
the multigrid solver during HMC simulations at the physical point.


title:
Dynamics and chaos in the unified scalar field cosmology II. System in a
  finite box

abstract:
  We revisit the global dynamics of unified dark matter cosmological models and
analyze it in a new dynamical system setting. In particular, by defining a
suitable set of variables we obtain a bounded variable space, a feature that
allows a better control of the critical elements of the system. First, we give
a comprehensive cosmological interpretation of the critical points. Then, we
turn our focus on particular representative trajectories with physically
motivated initial conditions studied in the first paper of the series, and we
discuss how the scale factor relates to the equation of state parameter. We
review and complement these results in the light of the new variable approach
by discussing the issue whether the system is chaotic or not.


title:
Autonomous Learning by Dynamical Systems with Inertial or Delayed
  Feedbacks

abstract:
  Dynamical systems can autonomously adapt their organization so that the
required target dynamics is reproduced. In the previous Rapid Communication
[Phys. Rev. E 90,030901(R) (2014)], it was shown how such systems can be
designed using delayed feedbacks. Here, the proposed method is further analyzed
and improved. Its extension to adaptable systems, where delays are absent and
inertial feedbacks are instead employed, is suggested. Numerical tests for
three different models, including networks of phase and amplitude oscillators,
are performed.


title: Analysis of Metagenome Composition by the Method of Random Primers

abstract:
  Metagenome, a mixture of different genomes (as a rule, bacterial), represents
a pattern, and the analysis of its composition is, currently, one of the
challenging problems of bioinformatics. In the present study, the possibility
of evaluating metagenome composition by DNA-marker methods is investigated.
These methods are based on using primers, short nucleic acid fragments. Each
primer picks out of the tested genome the fragment set specific just for this
genome, which is called its spectrum (for the given primer) and is used for
identifying the genome. The DNA-marker method, applied to a metagenome, also
gives its spectrum, which, obviously, represents the union of the spectra of
all genomes belonging to the metagenome. Thus each primer provides a projection
of the genomes and of the metagenome onto the corresponding spectra set. Here
we propose to apply the random projection (random primer) approach for
analyzing metagenome composition and present some estimates of the method
effectiveness for the case of Random Amplified Polymorphic DNA (RAPD)
technology.


title:
Classification of Curtis-Tits and Phan amalgams with $3$-spherical
  diagram

abstract:
  We classify all non-collapsing Curtis-Tits and Phan amalgams with
$3$-spherical diagram over all fields. In particular, we show that amalgams
with spherical diagram are unique, a result required by the classification of
finite simple groups. We give a simple condition on the amalgam which is
necessary and sufficient for it to arise from a group of Kac-Moody type. This
also yields a definition of a large class of groups of Kac-Moody type in terms
of a finite presentation.


title:
Entanglement spectra of superconductivity ground states on the honeycomb
  lattice

abstract:
  We analytically evaluate the entanglement spectra of the superconductivity
states in graphene, primarily focusing on the s-wave and chiral $
d_{x^{2}-y^{2}}+id_{xy} $ superconductivity states. We demonstrate that the
topology of the entanglement Hamiltonian can differ from that of the subsystem
Hamiltonian. In particular, the topological properties of the entanglement
Hamiltonian of the chiral $ d_{x^{2}-y^{2}}+id_{xy} $ superconductivity state
obtained by tracing out one spin direction clearly differ from those of the
time-reversal invariant Hamiltonian of noninteracting fermions on the honeycomb
lattice.


title: Inclusive {\Lambda} production in proton-proton collisions at 3.5 GeV

abstract:
  The inclusive production of {\Lambda} hyperons in proton-proton collisions at
$\sqrt{s}$ = 3.18 GeV was measured with HADES at the GSI Helmholtzzentrum f\"ur
Schwerionenforschung in Darmstadt. The experimental data are compared to a
data-based model for individual exclusive {\Lambda} production channels in the
same reaction. The contributions of intermediate resonances such as
{\Sigma}(1385), {\Delta}++ or N* are considered in detail. In particular, the
result of a partial wave analysis is accounted for the abundant pK$^+${\Lambda}
final state. Model and data show a reasonable agreement at mid rapidities,
while a difference is found for larger rapidities. A total {\Lambda} production
cross section in p+p collisions at $\sqrt{s}$ = 3.18 GeV of {\sigma}(pp $\to$
{\Lambda} + X) = 207.3 $\pm$ 1.3 +6.0 -7.3 (stat.) $\pm$ 8.4 (syst.) +0.4 -0.5
(model) {\mu}b is found.


title: Slow light in flight imaging

abstract:
  Slow-light media are of interest in the context of quantum computing and
enhanced measurement of quantum effects, with particular emphasis on using
slow-light with single photons. We use light-in-flight imaging with a single
photon avalanche diode camera-array to image in situ pulse propagation through
a slow light medium consisting of heated rubidium vapour. Light-in-flight
imaging of slow light propagation enables direct visualisation of a series of
physical effects including simultaneous observation of spatial pulse
compression and temporal pulse dispersion. Additionally, the single-photon
nature of the camera allows for observation of the group velocity of single
photons with measured single-photon fractional delays greater than 1 over 1 cm
of propagation.


title: Multi-Way Massive MIMO with Maximum-Ratio Processing and Imperfect CSI

abstract:
  This paper considers a multi-way massive multiple-input multiple-output
relaying system, where single-antenna users exchange their information-bearing
signals with the help of one relay station equipped with unconventionally many
antennas. The relay first estimates the channels to all users through the pilot
signals transmitted from them. Then, the relay uses maximum-ratio processing
(i.e. maximum-ratio combining in the multiple-access phase and maximum-ratio
transmission in the broadcast phase) to process the signals. A rigorous
closed-form expression for the spectral efficiency is derived. The effects of
the channel estimation error, the channel estimation overhead, the length of
the training duration, and the randomness of the user locations are analyzed.
We show that by deploying massive antenna arrays at the relay and simple
maximum-ratio processing, we can serve many users in the same time-frequency
resource, while maintaining a given quality-of-service for each user.


title: Uniformly valid confidence intervals post-model-selection

abstract:
  We suggest general methods to construct asymptotically uniformly valid
confidence intervals post-model-selection. The constructions are based on
principles recently proposed by Berk et al. (2013). In particular the candidate
models used can be misspecified, the target of inference is model-specific, and
coverage is guaranteed for any data-driven model selection procedure. After
developing a general theory we apply our methods to practically important
situations where the candidate set of models, from which a working model is
selected, consists of fixed design homoskedastic or heteroskedastic linear
models, or of binary regression models with general link functions. In an
extensive simulation study, we find that the proposed confidence intervals
perform remarkably well, even when compared to existing methods that are
tailored only for specific model selection procedures.


title:
On the $p$-adic periods of the modular curve $X(\Gamma_0(p) \cap
  \Gamma(2))$

abstract:
  We prove a variant of Oesterl\'e's conjecture about $p$-adic periods of the
modular curve $X_0(p)$, with an additional $\Gamma(2)$-structure. We use de
Shalit's techniques and $p$-adic uniformization of curves whose reduction is
semi-stable.


title:
Statistical Mechanics and the Climatology of the Arctic Sea Ice
  Thickness Distribution

abstract:
  We study the seasonal changes in the thickness distribution of Arctic sea
ice, $g(h)$, under climate forcing. Our analytical and numerical approach is
based on a Fokker-Planck equation for $g(h)$ (Toppaladoddi \& Wettlaufer
\emph{Phys. Rev. Lett.} {\bf 115}, 148501, 2015), in which the thermodynamic
growth rates are determined using observed climatology. In particular, the
Fokker-Planck equation is coupled to the observationally consistent
thermodynamic model of Eisenman \& Wettlaufer (\emph{Proc. Natl. Acad. Sci.
USA} {\bf 106}, pp. 28-32, 2009). We find that due to the combined effects of
thermodynamics and mechanics, $g(h)$ spreads during winter and contracts during
summer. This behavior is in agreement with recent satellite observations from
CryoSat-2 (Kwok \& Cunningham, \emph{Phil. Trans. R. Soc. A} {\bf 373},
20140157, 2015). Because $g(h)$ is a probability density function, we quantify
all of the key moments (e.g., mean thickness, fraction of thin/thick ice, mean
albedo, relaxation time scales) as greenhouse-gas radiative forcing, $\Delta
F_0$, increases. The mean ice thickness decays exponentially with $\Delta F_0$,
but {\em much slower} than do solely thermodynamic models. This exhibits the
crucial role that ice mechanics plays in maintaining the ice cover, by
redistributing thin ice to thick ice--far more rapidly than can thermal growth
alone.


title: Learning to Pivot with Adversarial Networks

abstract:
  Several techniques for domain adaptation have been proposed to account for
differences in the distribution of the data used for training and testing. The
majority of this work focuses on a binary domain label. Similar problems occur
in a scientific context where there may be a continuous family of plausible
data generation processes associated to the presence of systematic
uncertainties. Robust inference is possible if it is based on a pivot -- a
quantity whose distribution does not depend on the unknown values of the
nuisance parameters that parametrize this family of data generation processes.
In this work, we introduce and derive theoretical results for a training
procedure based on adversarial networks for enforcing the pivotal property (or,
equivalently, fairness with respect to continuous attributes) on a predictive
model. The method includes a hyperparameter to control the trade-off between
accuracy and robustness. We demonstrate the effectiveness of this approach with
a toy example and examples from particle physics.

categories: stat.ML cs.LG cs.NE physics.data-an stat.ME


title: Insights into the Deactivation of 5-Bromouracil after UV Excitation

abstract:
  5-Bromouracil is a nucleobase analogue that can replace thymine in DNA
strands and acts as a strong radiosensitizer, with potential applications in
molecular biology and cancer therapy. Here, the deactivation of 5-bromouracil
after UV irradiation is investigated in the singlet and triplet manifold by
accurate quantum chemistry calculations and nonadiabatic dynamics simulations.
It is found that after irradiation to the bright 1pipi* state, three main
relaxation pathways are in principle possible: relaxation back to the ground
state, intersystem crossing, and C-Br photodissociation. Based on accurate
MS-CASPT2 optimizations, we propose that ground state relaxation should be the
predominant deactivation pathway in gas phase. We then employ different
electronic structure methods to assess their suitability to carry out
excited-state dynamics simulations. MRCIS was used in surface hopping
simulations to compute the ultrafast intersystem crossing dynamics, which
mostly involves the 1nOpi* and 3pipi* states.


title: Local limits of large Galton-Watson trees rerooted at a random vertex

abstract:
  We discuss various forms of convergence of the vicinity of a uniformly at
random selected vertex in random simply generated trees, as the size tends to
infinity. For the standard case of a critical Galton-Watson tree conditioned to
be large the limit is the invariant random sin-tree constructed by Aldous
(1991). In the condensation regime, we describe in complete generality the
asymptotic local behaviour from a random vertex up to its first ancestor with
large degree. Beyond this distinguished ancestor, different behaviour may
occur, depending on the branching weights. In a subregime of complete
condensation, we obtain convergence toward a novel limit tree, that describes
the asymptotic shape of the vicinity of the full path from a random vertex to
the root vertex. This includes the case where the offspring distribution
follows a power law up to a factor that varies slowly at infinity.


title: Topological states in engineered atomic lattices

abstract:
  Topological materials exhibit protected edge modes that have been proposed
for applications in for example spintronics and quantum computation. While a
number of such systems exist, it would be desirable to be able to test
theoretical proposals in an artificial system that allows precise control over
the key parameters of the model. The essential physics of several topological
systems can be captured by tight-binding models, which can also be implemented
in artificial lattices. Here, we show that this method can be realized in a
vacancy lattice in a chlorine monolayer on a Cu(100) surface. We use
low-temperature scanning tunneling microscopy (STM) to fabricate such lattices
with atomic precision and probe the resulting local density of states (LDOS)
with scanning tunneling spectroscopy (STS). We create analogues of two
tight-binding models of fundamental importance: The polyacetylene (dimer) chain
with topological domain wall states, and the Lieb lattice, featuring a lattice
pseudospin 1 system with a flat electron band. These results provide the first
steps in realizing designer quantum materials with tailored properties.


title: On the structure of geodesic orbit Riemannian spaces

abstract:
  The paper is devoted to the study of geodesic orbit Riemannian spaces that
could be characterize by the property that any geodesic is an orbit of a
1-parameter group of isometries. In particular, we discuss some important
totally geodesic submanifolds that inherit the property to be geodesic orbit.
For a given geodesic orbit Riemannian space, we describe the structure of the
nilradical and the radical of the Lie algebra of the isometry group. In the
final part, we discuss some new tools to study geodesic orbit Riemannian
spaces, related to compact Lie group representations with non-trivial principal
isotropy algebras. We discuss also some new examples of geodesic orbit
Riemannian spaces, new methods to obtain such examples, and some unsolved
questions.


title:
Solving Reachability Problems by a Scalable Constrained Optimization
  Method

abstract:
  In this paper we consider the problem of finding an evolution of a dynamical
system that originates and terminates in given sets of states. However, if such
an evolution exists then it is usually not unique. We investigate this problem
and find a scalable approach for solving it. To this end we formulate an
equality constrained nonlinear program that addresses the non-uniqueness of the
solution of the original problem. In addition, the resulting saddle-point
matrix is sparse. We exploit the structure in order to reach an efficient
implementation of our method. In computational experiments we compare line
search and trust-region methods as well as various updates for the Hessian.


title: Equilibrium states on right LCM semigroup C*-algebras

abstract:
  We determine the structure of equilibrium states for a natural dynamics on
the boundary quotient diagram of $C^*$-algebras for a large class of right LCM
semigroups. The approach is based on abstract properties of the semigroup and
covers the previous case studies on $\mathbb{N} \rtimes \mathbb{N}^\times$,
dilation matrices, self-similar actions, and Baumslag-Solitar monoids. At the
same time, it provides new results for large classes of right LCM semigroups,
including those associated to algebraic dynamical systems.


title:
Coherent Order Parameter Oscillations in the Ground State of the
  Excitonic Insulator Ta2NiSe5

abstract:
  The excitonic insulator is an intriguing electronic phase of quasi-condensed
excitons. A prominent candidate is the small bandgap semiconductor Ta2NiSe5, in
which excitons are believed to undergo a BEC-like transition. But experimental
evidence for the existence of a coherent condensate in this material is still
missing. A direct fingerprint of such a state would be the observation of its
collective modes, which are equivalent to the Higgs- and Goldstone-modes in
superconductors. Here we report evidence for the existence of a coherent
amplitude response in the excitonic insulator phase of Ta2NiSe5. Using
non-linear excitations with short laser pulses we identify a phonon-coupled
state of the condensate that can be understood as a coupling of its electronic
Higgs-mode to a low frequency phonon. The Higgs-mode contribution substantiates
the picture of an electronically driven phase transition and characterizes the
transient order parameter of the excitonic insulator as a function of
temperature and excitation density.


title: Phase behavior of active Brownian disks, spheres, and dumbbells

abstract:
  In this paper we provide high precision estimates of the phase diagram of
active Brownian particles. We extract coexisting densities from simulations of
phase separated states in an elongated box (slab geometry) which minimizes
finite-size effects and allows for precise determination of points on the
binodal lines. Using this method, we study the influence of both shape and
dimensionality on the two-phase region. Active spheres and dumbbells of active
particles are compared to the known phase diagram of active Brownian disks. In
the case of dimers, both correlated and uncorrelated propulsion of the two
beads are studied. The influence of correlation is discussed through a simple
mapping.


title:
Learning Locomotion Skills Using DeepRL: Does the Choice of Action Space
  Matter?

abstract:
  The use of deep reinforcement learning allows for high-dimensional state
descriptors, but little is known about how the choice of action representation
impacts the learning difficulty and the resulting performance. We compare the
impact of four different action parameterizations (torques, muscle-activations,
target joint angles, and target joint-angle velocities) in terms of learning
time, policy robustness, motion quality, and policy query rates. Our results
are evaluated on a gait-cycle imitation task for multiple planar articulated
figures and multiple gaits. We demonstrate that the local feedback provided by
higher-level action parameterizations can significantly impact the learning,
robustness, and quality of the resulting policies.


title: Immigrant community integration in world cities

abstract:
  As a consequence of the accelerated globalization process, today major cities
all over the world are characterized by an increasing multiculturalism. The
integration of immigrant communities may be affected by social polarization and
spatial segregation. How are these dynamics evolving over time? To what extent
the different policies launched to tackle these problems are working? These are
critical questions traditionally addressed by studies based on surveys and
census data. Such sources are safe to avoid spurious biases, but the data
collection becomes an intensive and rather expensive work. Here, we conduct a
comprehensive study on immigrant integration in 53 world cities by introducing
an innovative approach: an analysis of the spatio-temporal communication
patterns of immigrant and local communities based on language detection in
Twitter and on novel metrics of spatial integration. We quantify the "Power of
Integration" of cities --their capacity to spatially integrate diverse
cultures-- and characterize the relations between different cultures when
acting as hosts or immigrants.


title: Sub-diffusive electronic states in octagonal tiling

abstract:
  We study the quantum diffusion of charge carriers in octagonal tilings. Our
numerical results show a power law decay of the wave-packet spreading, $L(t)
\propto t^{\beta}$, characteristic of critical states in quasicrystals at large
time $t$. For many energies states are sub-diffusive, i.e. $\beta < 0.5$, and
thus conductivity increases when the amount of defects (static defects and/or
temperature) increases.


title: Surface effects on nitrogen vacancy centers neutralization in diamond

abstract:
  The performance of nitrogen vacancy (NV$^{-}$) based magnetic sensors
strongly depends on the stability of nitrogen vacancy centers near the diamond
surface. The sensitivity of magnetic field detection is diminished as the
NV$^{-}$ turns into the neutralized charge state NV$^{0}$. We investigate the
neutralization of NV$^{-}$ and calculate the ratio of NV$^{0}$ to total NV
(NV$^{-}$+NV$^{0}$) caused by a hydrogen terminated diamond with a surface
water layer. We find that NV$^{-}$ neutralization exhibits two distinct
regions: near the surface, where the NV$^{-}$ is completely neutralized, and in
the bulk, where the\ neutralization ratio is inversely proportional to depth
following the electrostatic force law. In addition, small changes in
concentration can lead to large differences in neutralization behavior. This
phenomenon allows one to carefully control the concentration to decrease the
NV$^{-}$ neutralization. The presence of nitrogen dopant greatly reduces
NV$^{-}$ neutralization as the nitrogen ionizes in preference to NV$^{-}$
neutralization at the same depth. The water layer pH also affects
neutralization. If the pH is very low due to cleaning agent residue, then we
see a change in the band bending and the reduction of the $2$-dimensional hole
gas (DHG) region. Finally, we find that dissolved carbon dioxide resulting from
direct contact with the atmosphere at room temperature hardly affects the
NV$^{-}$ neutralization.


title: Diffusion on Delone sets

abstract:
  We consider graphs associated to Delone sets in Euclidean space. Such graphs
arise in various ways from tilings. Here, we provide a unified framework. In
this context, we study the associated Laplace operators and show Gaussian heat
kernel bounds for their semigroups. These results apply to both metric and
discrete graphs.


title:
A-Ward_p\b{eta}: Effective hierarchical clustering using the Minkowski
  metric and a fast k -means initialisation

abstract:
  In this paper we make two novel contributions to hierarchical clustering.
First, we introduce an anomalous pattern initialisation method for hierarchical
clustering algorithms, called A-Ward, capable of substantially reducing the
time they take to converge. This method generates an initial partition with a
sufficiently large number of clusters. This allows the cluster merging process
to start from this partition rather than from a trivial partition composed
solely of singletons. Our second contribution is an extension of the Ward and
Ward p algorithms to the situation where the feature weight exponent can differ
from the exponent of the Minkowski distance. This new method, called A-Ward
p\b{eta} , is able to generate a much wider variety of clustering solutions. We
also demonstrate that its parameters can be estimated reasonably well by using
a cluster validity index. We perform numerous experiments using data sets with
two types of noise, insertion of noise features and blurring within-cluster
values of some features. These experiments allow us to conclude: (i) our
anomalous pattern initialisation method does indeed reduce the time a
hierarchical clustering algorithm takes to complete, without negatively
impacting its cluster recovery ability; (ii) A-Ward p\b{eta} provides better
cluster recovery than both Ward and Ward p.


title: A Self-Referential Property of Zimin Words

abstract:
  This paper gives a short overview of Zimin words, and proves an interesting
property of their distribution. Let $L_q^m$ to be the lexically ordered
sequence of $q$-ary words of length $m$, and let $T_n(L_q^m)$ to be the binary
sequence where the $i$-th term is $1$ if and only if the $i$-th word of $L_q^m$
encounters the $n$-th Zimin word, $Z_n$. We show that the sequence $T_n(L_q^m)$
is an instance of $Z_{n+1}$ when $1 < n$ and $m=2^n-1$.


title: Stellar Pulsations in Beyond Horndeski Gravity Theories

abstract:
  Theories of gravity in the beyond Horndeski class recover the predictions of
general relativity in the solar system whilst admitting novel cosmologies,
including late-time de Sitter solutions in the absence of a cosmological
constant. Deviations from Newton's law are predicted inside astrophysical
bodies, which allow for falsifiable, smoking-gun tests of the theory. In this
work we study the pulsations of stars by deriving and solving the wave equation
governing linear adiabatic oscillations to find the modified period of
pulsation. Using both semi-analytic and numerical models, we perform a
preliminary survey of the stellar zoo in an attempt to identify the best
candidate objects for testing the theory. Brown dwarfs and Cepheid stars are
found to be particularly sensitive objects and we discuss the possibility of
using both to test the theory.


title: Stochastic Invariants for Probabilistic Termination

abstract:
  Termination is one of the basic liveness properties, and we study the
termination problem for probabilistic programs with real-valued variables.
Previous works focused on the qualitative problem that asks whether an input
program terminates with probability~1 (almost-sure termination). A powerful
approach for this qualitative problem is the notion of ranking supermartingales
with respect to a given set of invariants. The quantitative problem
(probabilistic termination) asks for bounds on the termination probability. A
fundamental and conceptual drawback of the existing approaches to address
probabilistic termination is that even though the supermartingales consider the
probabilistic behavior of the programs, the invariants are obtained completely
ignoring the probabilistic aspect.
  In this work we address the probabilistic termination problem for
linear-arithmetic probabilistic programs with nondeterminism. We define the
notion of {\em stochastic invariants}, which are constraints along with a
probability bound that the constraints hold. We introduce a concept of {\em
repulsing supermartingales}. First, we show that repulsing supermartingales can
be used to obtain bounds on the probability of the stochastic invariants.
Second, we show the effectiveness of repulsing supermartingales in the
following three ways: (1)~With a combination of ranking and repulsing
supermartingales we can compute lower bounds on the probability of termination;
(2)~repulsing supermartingales provide witnesses for refutation of almost-sure
termination; and (3)~with a combination of ranking and repulsing
supermartingales we can establish persistence properties of probabilistic
programs.
  We also present results on related computational problems and an experimental
evaluation of our approach on academic examples.


title: Experimental adaptive process tomography

abstract:
  Adaptive measurements were recently shown to significantly improve the
performance of quantum state tomography. Utilizing information about the system
for the on-line choice of optimal measurements allows to reach the ultimate
bounds of precision for state reconstruction. In this article we generalize an
adaptive Bayesian approach to the case of process tomography and experimentally
show its superiority in the task of learning unknown quantum operations. Our
experiments with photonic polarization qubits cover all types of single-qubit
channels. We also discuss instrumental errors and the criteria for evaluation
of the ultimate achievable precision in an experiment. It turns out, that
adaptive tomography provides a lower noise floor in the presence of strong
technical noise.


title:
Spherical, hyperbolic and other projective geometries: convexity,
  duality, transitions

abstract:
  Since the end of the 19th century, and after the works of F. Klein and H.
Poincar\'e, it is well known that models of elliptic geometry and hyperbolic
geometry can be given using projective geometry, and that Euclidean geometry
can be seen as a "limit" of both geometries. Then all the geometries that can
be obtained in this way. Some of these geometries had a rich development, most
remarkably hyperbolic geometry and the Lorentzian geometries of Minkowski, de
Sitter and anti-de Sitter spaces, which in higher dimension have had large
interest for a long time in mathematical physics and more precisely in General
Relativity. Moreover, some degenerate spaces appear naturally in the picture,
namely the co-Euclidean space (the space of hyperplanes of the Euclidean
space), and the co-Minkowski space (that we will restrict to the space of
space-like hyperplanes of Minkowski space), first because of duality reasons,
and second because they appear as limits of degeneration of classical spaces.
In fact, co-Minkowski space recently regained interest under the name half-pipe
geometry. The purpose of the present paper is to provide a survey on the
properties of these spaces, especially in dimensions 2 and 3, from the point of
view of projective geometry. Even with this perspective, the paper does not aim
to be an exhaustive treatment. Instead it is focused on the aspects which
concern convex subsets and their duality, degeneration of geometries and some
properties of surfaces in three-dimensional spaces. The presentation is
intended to be elementary, hence containing no deep proofs of theorems, but
trying to proceed by accessible observations and elementary proofs.


title:
Sparse Generalized Eigenvalue Problem with Application to Canonical
  Correlation Analysis for Integrative Analysis of Methylation and Gene
  Expression Data

abstract:
  We present a method for individual and integrative analysis of high
dimension, low sample size data that capitalizes on the recurring theme in
multivariate analysis of projecting higher dimensional data onto a few
meaningful directions that are solutions to a generalized eigenvalue problem.
We propose a general framework, called SELP (Sparse Estimation with Linear
Programming), with which one can obtain a sparse estimate for a solution vector
of a generalized eigenvalue problem. We demonstrate the utility of SELP on
canonical correlation analysis for an integrative analysis of methylation and
gene expression profiles from a breast cancer study, and we identify some genes
known to be associated with breast carcinogenesis, which indicates that the
proposed method is capable of generating biologically meaningful insights.
Simulation studies suggest that the proposed method performs competitive in
comparison with some existing methods in identifying true signals in various
underlying covariance structures.


title: Magnetohydrodynamic DiscWinds and LineWidth Distributions.II

abstract:
  We study AGN emission line profiles combining an improved version of the
accretion disc-wind model of Murray & Chiang with the magneto-hydrodynamic
model of Emmering et al. (1992). Here we extend our previous work to consider
central objects with different masses and/or luminosities. We have compared the
dispersions in our model C IV linewidth distributions to observational upper
limit on that dispersion, considering both smooth and clumpy torus models.
Following Fine et al., we transform that scatter in the profile line-widths
into a constraint on the torus geometry and show how the half-opening angle of
the obscuring structure depends on the mass of the central object and the
accretion rate. We find that the results depend only mildly on the
dimensionless angular momentum, one of the two integrals of motion that
characterise the dynamics of the self-similar ideal MHD outflows


title: Electronic Structure Calculatins and the Ising Machine

abstract:
  The exact solution of Schrodinger equation for atoms, molecules and extended
systems continues to be a "Holy Grail" problem that the entire field has been
striving to solve since its inception. Recently, breakthroughs have been made
in the development of quantum annealing and coherent Ising machines capable of
simulating hundreds of connected spins interacting with an Ising type
Hamiltonian. One of the most vital questions pertaining to these new devices
is: 'can these machine be used to perform electronic structure calculations?'
Here we discuss the general procedure used by these devices and show that there
is an exact mapping between the electronic structure Hamiltonian of the
Hydrogen molecule and the Ising Hamiltonian


title: Maxima Units Search (MUS) algorithm: methodology and applications

abstract:
  An algorithm for extracting identity submatrices of small rank and pivotal
units from large and sparse matrices is proposed. The procedure has already
been satisfactorily applied for solving the label switching problem in Bayesian
mixture models. Here we introduce it on its own and explore possible
applications in different contexts.


title: The accretion of migrating giant planets

abstract:
  Most studies concerning the growth and evolution of massive planets focus
either on their accretion or their migration only. In this work we study both
processes concurrently to investigate how they might mutually affect each
other. We modeled a 2-dimensional disk with a steady accretion flow onto the
central star and embed a Jupiter mass planet at 5.2 au. The disk is locally
isothermal and viscosity is modeled using a constant $\alpha$. The planet is
held on a fixed orbit for a few hundred orbits to allow the disk to adapt and
carve a gap. After this period, the planet is released and free to move
according to the gravitational interaction with the gas disk. The mass
accretion onto the planet is modeled by removing a fraction of gas from the
inner Hill sphere, and the removed mass and momentum can be added to the
planet. Our results show that a fast migrating planet is able to accrete more
gas than a slower migrating planet. Utilizing a tracer fluid we analyzed the
origin of the accreted gas which comes predominantly originating from the inner
disk for a fast migrating planet. In case of slower migration the fraction of
gas from the outer disk increases. We also found that even for very high
accretion rates in some cases gas crosses the planetary gap from the inner to
the outer disk. Our simulations show that the crossing of gas changes during
the migration process as the migration rate slows down. Therefore classical
type II migration where the planet migrates with the viscous drift rate and no
gas crosses the gap is no general process but may only occur for special
parameters and at a certain time during the orbital evolution of the planet.


title:
Inflowing gas onto a compact obscured nucleus in Arp 299A: Herschel
  spectroscopic studies of H2O and OH

abstract:
  Aims. We probe the physical conditions in the core of Arp 299A and try to put
constraints to the nature of its nuclear power source. Methods. We used
Herschel Space Observatory far-infrared and submillimeter observations of H2O
and OH rotational lines in Arp 299A to create a multi-component model of the
galaxy. In doing this, we employed a spherically symmetric radiative transfer
code. Results. Nine H2O lines in absorption and eight in emission as well as
four OH doublets in absorption and one in emission, are detected in Arp 299A.
No lines of the 18O isotopologues, which have been seen in compact obscured
nuclei of other galaxies, are detected. The absorption in the ground state OH
doublet at 119 {\mu}m is found redshifted by ~175 km/s compared to other OH and
H2O lines, suggesting a low excitation inflow. We find that at least two
components are required in order to account for the excited molecular line
spectrum. The inner component has a radius of 20-25 pc, a very high infrared
surface brightness (> 3e13 Lsun/kpc^2), warm dust (Td > 90 K), and a large H2
column density (NH2 > 1e24 cm^-2). The outer component is larger (50-100 pc)
with slightly cooler dust (70-90 K). In addition, a much more extended
inflowing component is required to also account for the OH doublet at 119
{\mu}m. Conclusions. The Compton-thick nature of the core makes it difficult to
determine the nature of the buried power source, but the high surface
brightness indicates that it is either an active galactic nucleus and/or a
dense nuclear starburst. The high OH/H2O ratio in the nucleus indicates that
ion-neutral chemistry induced by X-rays or cosmic-rays is important. Finally we
find a lower limit to the 16O/18O ratio of 400 in the nuclear region, possibly
indicating that the nuclear starburst is in an early evolutionary stage, or
that it is fed through a molecular inflow of, at most, solar metallicity.


title:
The effect of cosmic web filaments on the properties of groups and their
  central galaxies

abstract:
  The nature versus nurture scenario in galaxy and group evolution is a
long-standing problem not yet fully understood on cosmological scales. We study
the properties of groups and their central galaxies in different large-scale
environments defined by the luminosity density field and the cosmic web
filaments. We use the luminosity density field constructed using 8 Mpc/h
smoothing to characterize the large-scale environments and the Bisous model to
extract the filamentary structures in different large-scale environments. We
find differences in the properties of central galaxies and their groups in and
outside of filaments at fixed halo and large-scale environments. In
high-density environments, the group mass function has higher number densities
in filaments compared to that outside of filaments towards the massive end. The
relation is opposite in low-density environments. At fixed group mass and
large-scale luminosity density, groups in filaments are slightly more luminous
and their central galaxies have redder colors, higher stellar masses, and lower
specific star formation rates than those outside of filaments. However, the
differences in central galaxy and group properties in and outside of filaments
are not clear in some group mass bins. We show that the differences in central
galaxy properties are due to the higher abundances of elliptical galaxies in
filaments. Filamentary structures in the cosmic web are not simply visual
associations of galaxies, but rather play an important role in shaping the
properties of groups and their central galaxies. The differences in central
galaxy and group properties in and outside of cosmic web filaments are not
simple effects related to large-scale environmental density. The results point
towards an efficient mechanism in cosmic web filaments which quench star
formation and transform central galaxy morphology from late to early types.


title:
Exact results for polaron and molecule in one-dimensional spin-1/2 Fermi
  gas

abstract:
  Using exact Bethe ansatz (BA) solutions, we show that a spin-down fermion
immersed into a fully polarized spin-up Fermi sea with a weak attraction is
dressed by the surrounding spin-up fermions to form the one-dimensional analog
of a polaron. As the attraction becomes strong, the spin-down fermion binds
with one spin-up fermion to form a tightly bound molecule. Throughout the whole
interaction regime, a crossover from the polaron to a molecule state is fully
demonstrated through exact results of the excitation spectrum, the effective
mass, binding energy and kinetic energy. Furthermore, a clear distinction
between the polaron and molecule is conceived by the probability distribution,
single particle reduced density matrix and density-density correlations, which
are calculated directly from the Bethe ansatz wave function. Such a
polaron-molecule crossover presents a universal nature of an impurity immersed
into a fermionic medium with an attraction in one dimension.


title:
Diffractive imaging of transient electronic core-shell structures in a
  nanoplasma

abstract:
  We have recorded the coherent diffraction images of individual xenon clusters
with intense extreme ultraviolet pulses to elucidate the influence of
light-induced electronic changes on the diffraction pattern. Using the FLASH
free-electron laser we tuned the wavelength to specific xenon atomic and ionic
resonances. The data show the emergence of a transient core-shell structure
within the otherwise homogeneous sample. Simulations indicate that ionization
and nanoplasma formation result in a cluster shell with strongly altered
refraction. The presented resonant scattering approach enables imaging of
ultrafast electron dynamics on their natural time scale.


title:
Equivariant Cohomology of the Moduli Space of Genus Three Curves with
  Symplectic Level Two Structure via Point Counts

abstract:
  We make cohomological computations related to the moduli space of genus three
curves with symplectic level two structure by means of counting points over
finite fields. In particular, we determine the cohomology groups of the quartic
locus as representations of the symmetric group on seven elements.


title:
Implementation of a goodness-of-fit test for finding optimal concurrent
  radio and {\gamma}-ray pulsar light curves

abstract:
  Since the launch of the Fermi Large Area Telescope in 2008 the number of
known ${\gamma}$-ray pulsars has increased immensely to over 200, many of which
are also visible in the radio and X-ray bands. Seyffert et al. (2011)
demonstrated how constraints on the viewing geometries of some of these pulsars
could be obtained by comparing their observed radio and ${\gamma}$-ray light
curves by eye to light curves from geometric models. While these constraints
compare reasonably well with those yielded by more rigorous single-wavelength
approaches, they are still a somewhat subjective representation of how well the
models reproduce the observed radio and ${\gamma}$-ray light curves.
Constructing a more rigorous approach is, however, made difficult by the large
uncertainties associated with the ${\gamma}$-ray light curves as compared to
those associated with the radio light curves. Naively applying a
${\chi}^{2}$-like goodness-of-fit test to both bands invariably results in
constraints dictated by the radio light curves. A number of approaches have
been proposed to address this issue. In this paper we investigate these
approaches and evaluate the results they yield. Based on what we learn, we
implement our own version of a goodness-of-fit test, which we then use to
investigate the behaviour of the geometric models in multi-dimensional phase
space.


title: Ramification of Wild Automorphisms of Laurent Series Fields

abstract:
  Let $K$ be a complete discrete valuation field with residue class field $k$,
where both are of positive characteristic $p$. Then the group of wild
automorphisms of $K$ can be identified with the group under composition of
formal power series over $k$ with no constant term and $X$-coefficient $1$.
Under the hypothesis that $p > b^2$, we compute the first nontrivial
coefficient of the $p$th iterate of a power series over $k$ of the form $f = X
+ \sum_{i \geq 1} a_iX^{b+i}$. As a result, we obtain a necessary and
sufficient condition for an automorphism to be ``$b$-ramified,'' having lower
ramification numbers of the form $i_n(f) = b(1 + \cdots + p^n)$. This is a vast
generalization of Nordqvist's 2017 theorem on $2$-ramified power series, as
well as the analogous result for minimally ramified power series which proved
to be useful for arithmetic dynamics in a 2013 paper of Lindahl on
linearization discs in $\mathbf{C}_p$ and a 2015 result of
Lindahl--Rivera-Letelier on optimal cycles over nonarchimedean fields of
positive residue characteristic. The success of our computation is also
promising progress towards a generalization of Lindahl--Nordqvist's 2018
theorem bounding the norm of periodic points of $2$-ramified power series.


title: Classifying unavoidable Tverberg partitions

abstract:
  Let $T(d,r) = (r-1)(d+1)+1$ be the parameter in Tverberg's theorem, and call
a partition $\mathcal I$ of $\{1,2,\ldots,T(d,r)\}$ into $r$ parts a "Tverberg
type". We say that $\mathcal I$ "occurs" in an ordered point sequence $P$ if
$P$ contains a subsequence $P'$ of $T(d,r)$ points such that the partition of
$P'$ that is order-isomorphic to $\mathcal I$ is a Tverberg partition. We say
that $\mathcal I$ is "unavoidable" if it occurs in every sufficiently long
point sequence.
  In this paper we study the problem of determining which Tverberg types are
unavoidable. We conjecture a complete characterization of the unavoidable
Tverberg types, and we prove some cases of our conjecture for $d\le 4$. Along
the way, we study the avoidability of many other geometric predicates.
  Our techniques also yield a large family of $T(d,r)$-point sets for which the
number of Tverberg partitions is exactly $(r-1)!^d$. This lends further support
for Sierksma's conjecture on the number of Tverberg partitions.


title: Cutoff at the "entropic time" for sparse Markov chains

abstract:
  We study convergence to equilibrium for a large class of Markov chains in
random environment. The chains are sparse in the sense that in every row of the
transition matrix $P$ the mass is essentially concentrated on few entries.
Moreover, the random environment is such that rows of $P$ are independent and
such that the entries are exchangeable within each row. This includes various
models of random walks on sparse random directed graphs. The models are
generally non reversible and the equilibrium distribution is itself unknown. In
this general setting we establish the cutoff phenomenon for the total variation
distance to equilibrium, with mixing time given by the logarithm of the number
of states times the inverse of the average row entropy of $P$. As an
application, we consider the case where the rows of $P$ are i.i.d. random
vectors in the domain of attraction of a Poisson-Dirichlet law with index
$\alpha\in(0,1)$. Our main results are based on a detailed analysis of the
weight of the trajectory followed by the walker. This approach offers an
interpretation of cutoff as an instance of the concentration of measure
phenomenon.


title: Probabilistic Modeling of Progressive Filtering

abstract:
  Progressive filtering is a simple way to perform hierarchical classification,
inspired by the behavior that most humans put into practice while attempting to
categorize an item according to an underlying taxonomy. Each node of the
taxonomy being associated with a different category, one may visualize the
categorization process by looking at the item going downwards through all the
nodes that accept it as belonging to the corresponding category. This paper is
aimed at modeling the progressive filtering technique from a probabilistic
perspective, in a hierarchical text categorization setting. As a result, the
designer of a system based on progressive filtering should be facilitated in
the task of devising, training, and testing it.


title: On the tangent groupoid of a filtered manifold

abstract:
  We give an intrinsic (coordinate-free) construction of the tangent groupoid
of a filtered manifold.


title: The Geometry of the Mappings by General Dirichlet Series

abstract:
  We dealt in a series of previous publications with some geometric aspects of
the mappings by functions obtained as analytic continuations to the whole
complex plane of general Dirichlet series. Pictures illustrating those aspects
contain a lot of other information which has been waiting for a rigorous proof.
Such a task is partially fulfilled in this paper, where we succeeded among
other things, to prove a theorem about general Dirichlet series having as
corollary the Speiser's theorem. We have also proved that those functions do
not possess multiple zeros of order higher than $2$ and the double zeros have
very particular locations. Moreover, their derivatives have only simple zeros.
With these results at hand, we revisited GRH for a simplified proof.


title:
A Hybrid Approach to Word Sense Disambiguation Combining Supervised and
  Unsupervised Learning

abstract:
  In this paper, we are going to find meaning of words based on distinct
situations. Word Sense Disambiguation is used to find meaning of words based on
live contexts using supervised and unsupervised approaches. Unsupervised
approaches use online dictionary for learning, and supervised approaches use
manual learning sets. Hand tagged data are populated which might not be
effective and sufficient for learning procedure. This limitation of information
is main flaw of the supervised approach. Our proposed approach focuses to
overcome the limitation using learning set which is enriched in dynamic way
maintaining new data. Trivial filtering method is utilized to achieve
appropriate training data. We introduce a mixed methodology having Modified
Lesk approach and Bag-of-Words having enriched bags using learning methods. Our
approach establishes the superiority over individual Modified Lesk and
Bag-of-Words approaches based on experimentation.


abstract:
  We give a Jensen operator inequality for strongly convex functions. As a
corollary, we improve operator Holder-McCarthy inequality under suitable
conditions.


title:
Anomalous excitation facilitation in inhomogeneously broadened Rydberg
  gases

abstract:
  When atomic gases are laser driven to Rydberg states in an off resonant way,
a single Rydberg atom may enhance the excitation rate of surrounding atoms.
This leads to a facilitated excitation referred to as Rydberg anti-blockade. In
the usual facilitation scenario, the detuning of the laser from resonance
compensates the interaction shift. Here, we discuss a different excitation
mechanism, which we call anomalous facilitation. This occurs on the "wrong
side" of the resonance and originates from inhomogeneous broadening. The
anomalous facilitation may be seen in experiments of attractively interacting
atoms on the blue detuned side, where facilitation is not expected to appear.


title: Online Bayesian Inference of Diffusion Networks

abstract:
  Understanding the process by which a contagion disseminates throughout a
network is of great importance in many real world applications. The required
sophistication of the inference approach depends on the type of information we
want to extract as well as the number of observations that are available to us.
We analyze scenarios in which not only the underlying network structure
(parental relationships and link strengths) needs to be detected, but also the
infection times must be estimated. We assume that our only observation of the
diffusion process is a set of time series, one for each node of the network,
which exhibit changepoints when an infection occurs. After formulating a model
to describe the contagion, and selecting appropriate prior distributions, we
seek to find the set of model parameters that best explains our observations.
Modeling the problem in a Bayesian framework, we exploit Monte Carlo Markov
Chain,
  Sequential Monte Carlo, and time series analysis techniques to develop batch
and online inference algorithms. We evaluate the performance of our proposed
algorithms via numerical simulations of synthetic network contagions and
analysis of real-world datasets.


title:
Transforming differential equations of multi-loop Feynman integrals into
  canonical form

abstract:
  The method of differential equations has been proven to be a powerful tool
for the computation of multi-loop Feynman integrals appearing in quantum field
theory. It has been observed that in many instances a canonical basis can be
chosen, which drastically simplifies the solution of the differential equation.
In this paper, an algorithm is presented that computes the transformation to a
canonical basis, starting from some basis that is, for instance, obtained by
the usual integration-by-parts reduction techniques. The algorithm requires the
existence of a rational transformation to a canonical basis, but is otherwise
completely agnostic about the differential equation. In particular, it is
applicable to problems involving multiple scales and allows for a rational
dependence on the dimensional regulator. It is demonstrated that the algorithm
is suitable for current multi-loop calculations by presenting its successful
application to a number of non-trivial examples.


title:
Lack of nuclear clusters in dwarf spheroidal galaxies: implications for
  massive black holes formation and the cusp/core problem

abstract:
  One of the leading scenarios for the formation of nuclear star clusters in
galaxies is related to the orbital decay of globular clusters (GCs) and their
subsequent merging, though alternative theories are currently debated. The
availability of high-quality data for GCs structural and orbital parameters
allow to test different nuclear star cluster formation scenarios. The Fornax
dwarf spheroidal (dSph) galaxy is the heaviest satellite of the Milky Way and
it is the only known dwarf spheroidal hosting 5 GCs, whereas there are no clear
signatures for the presence of a central massive black hole. For this reason,
it represents a suited place to study the orbital decay process in dwarf
galaxies. In this paper we model the future evolution of the Fornax GCs
simulating them and the host galaxy by means of direct $N$-body simulations.
Our simulations take in account also the gravitational field generated by the
Milky Way. We found that if the Fornax galaxy is embedded in a standard Cold
Dark Matter Halo, the nuclear cluster formation would be significantly hampered
by the high central galactic mass density. In this context, we discuss the
possibility that infalling GCs drive the flattening of the galactic density
profile, giving a possible alternative explanation to the so-called cusp/core
problem. Moreover, we briefly discuss the link between GC infall process and
the absence of massive black holes in the centre of dSphs.


title:
LigoDV-web: Providing easy, secure and universal access to a large
  distributed scientific data store for the LIGO Scientific Collaboration

abstract:
  Gravitational-wave observatories around the world, including the Laser
Interferometer Gravitational-wave Observatory (LIGO), record a large volume of
gravitational-wave output data and auxiliary data about the instruments and
their environments. These data are stored at the observatory sites and
distributed to computing clusters for data analysis. LigoDV-web is a web-based
data viewer that provides access to data recorded at the LIGO Hanford, LIGO
Livingston and GEO600 observatories, and the 40m prototype interferometer at
Caltech. The challenge addressed by this project is to provide meaningful
visualizations of small data sets to anyone in the collaboration in a fast,
secure and reliable manner with minimal software, hardware and training
required of the end users. LigoDV-web is implemented as a Java Enterprise
Application, with Shibboleth Single Sign On for authentication and
authorization and a proprietary network protocol used for data access on the
back end. Collaboration members with proper credentials can request data be
displayed in any of several general formats from any Internet appliance that
supports a modern browser with Javascript and minimal HTML5 support, including
personal computers, smartphones, and tablets. To date 634 unique users have
visited the LigoDV-web website in a total of 33,861 sessions and generated a
total of 139,875 plots. This infrastructure has been helpful in many analyses
within the collaboration including follow-up of the data surrounding the first
gravitational-wave events observed by LIGO in 2015.


title: General and Fractional Hypertree Decompositions: Hard and Easy Cases

abstract:
  Hypertree decompositions, as well as the more powerful generalized hypertree
decompositions (GHDs), and the yet more general fractional hypertree
decompositions (FHD) are hypergraph decomposition methods successfully used for
answering conjunctive queries and for the solution of constraint satisfaction
problems. Every hypergraph H has a width relative to each of these
decomposition methods: its hypertree width hw(H), its generalized hypertree
width ghw(H), and its fractional hypertree width fhw(H), respectively.
  It is known that hw(H) <= k can be checked in polynomial time for fixed k,
while checking ghw(H) <= k is NP-complete for any k greater than or equal to 3.
The complexity of checking fhw(H) <= k for a fixed k has been open for more
than a decade.
  We settle this open problem by showing that checking fhw(H) <= k is
NP-complete, even for k=2. The same construction allows us to prove also the
NP-completeness of checking ghw(H) <= k for k=2. After proving these hardness
results, we identify meaningful restrictions, for which checking for bounded
ghw or fhw becomes tractable.


title:
Bernstein polynomial of 2-Puiseux pairs irreducible plane curve
  singularities

abstract:
  In 1982, Tamaki Yano proposed a conjecture predicting the set of b-exponents
of an irreducible plane curve singularity germ which is generic in its
equisingularity class. In \cite{ACLM-Yano2} we proved the conjecture for the
case in which the germ has two Puiseux pairs and its algebraic monodromy has
distinct eigenvalues. In this article we aim to study the Bernstein polynomial
for any function with the hypotheses above. In particular the set of all common
roots of those Bernstein polynomials is given. We provide also bounds for some
analytic invariants of singularities and illustrate the computations in
suitable examples.


title:
Cohomology Rings of Moduli of Point Configurations on the Projective
  Line

abstract:
  We describe the Chow rings of moduli spaces of ordered configurations of
points on the projective line for arbitrary (sufficiently generic) stabilities.
As an application, we exhibit such a moduli space admitting two small
desingularizations with non-isomorphic cohomology rings.


title: Performance of Interoperator Fixed-Mobile Network Sharing

abstract:
  We evaluate the downstream performance of our novel interoperator
fixed-mobile network sharing, in which operators exchange data in their access
networks. We propose a performance evaluation algorithm, and report credible
performance evaluation results obtained for 204600 randomly-generated passive
optical networks. We show that with the proposed sharing, operators can
increase their access network performance even twofold with software-defined
upgrades, and with no or minimal new hardware required.


title: Modular invariants and isogenies

abstract:
  We provide explicit bounds on the difference of heights of the $j$-invariants
of isogenous elliptic curves defined over $\overline{\mathbb{Q}}$. The first
one is reminiscent of a classical estimate for the Faltings height of isogenous
abelian varieties, which is indeed used in the proof. We also use an explicit
version of Silverman's inequality and isogeny estimates by Gaudron and
R\'emond. We give applications to the study of V\'elu's formulas and of modular
polynomials.


title:
Radial gradients in initial mass function sensitive absorption features
  in the Coma brightest cluster galaxies

abstract:
  Using the Oxford Short Wavelength Integral Field specTrograph (SWIFT), we
trace radial variations of initial mass function (IMF) sensitive absorption
features of three galaxies in the Coma cluster. We obtain resolved spectroscopy
of the central 5kpc for the two central brightest-cluster galaxies (BCGs)
NGC4889, NGC4874, and the BCG in the south-west group NGC4839, as well as
unresolved data for NGC4873 as a low-$\sigma_*$ control. We present radial
measurements of the IMF-sensitive features sodium NaI$_{\rm{SDSS}}$, calcium
triplet CaT and iron-hydride FeH0.99, along with the magnesium MgI0.88 and
titanium oxide TiO0.89 features. We employ two separate methods for both
telluric correction and sky-subtraction around the faint FeH feature to verify
our analysis. Within NGC4889 we find strong gradients of NaI$_{\rm{SDSS}}$ and
CaT but a flat FeH profile, which from comparing to stellar population
synthesis models, suggests an old, $\alpha$-enhanced population with a
Chabrier, or even bottom-light IMF. The age and abundance is in line with
previous studies but the normal IMF is in contrast to recent results suggesting
an increased IMF slope with increased velocity dispersion. We measure flat
NaI$_{\rm{SDSS}}$ and FeH profiles within NGC4874 and determine an old,
possibly slightly $\alpha$-enhanced and Chabrier IMF population. We find an
$\alpha$-enhanced, Chabrier IMF population in NGC4873. Within NGC4839 we
measure both strong NaI$_{\rm{SDSS}}$ and strong FeH, although with a large
systematic uncertainty, suggesting a possible heavier IMF. The IMFs we infer
for these galaxies are supported by published dynamical modelling. We stress
that IMF constraints should be corroborated by further spectral coverage and
independent methods on a galaxy-by-galaxy basis.


title: Spectral community detection in heterogeneous large networks

abstract:
  In this article, we study spectral methods for community detection based on $
\alpha$-parametrized normalized modularity matrix hereafter called $ {\bf
L}_\alpha $ in heterogeneous graph models. We show, in a regime where community
detection is not asymptotically trivial, that $ {\bf L}_\alpha $ can be well
approximated by a more tractable random matrix which falls in the family of
spiked random matrices. The analysis of this equivalent spiked random matrix
allows us to improve spectral methods for community detection and assess their
performances in the regime under study. In particular, we prove the existence
of an optimal value $ \alpha_{\rm opt} $ of the parameter $ \alpha $ for which
the detection of communities is best ensured and we provide an on-line
estimation of $ \alpha_{\rm opt} $ only based on the knowledge of the graph
adjacency matrix. Unlike classical spectral methods for community detection
where clustering is performed on the eigenvectors associated with extreme
eigenvalues, we show through our theoretical analysis that a regularization
should instead be performed on those eigenvectors prior to clustering in
heterogeneous graphs. Finally, through a deeper study of the regularized
eigenvectors used for clustering, we assess the performances of our new
algorithm for community detection. Numerical simulations in the course of the
article show that our methods outperform state-of-the-art spectral methods on
dense heterogeneous graphs.


title: Probing Majorana Neutrino Textures at DUNE

abstract:
  We study the possibility of probing different texture zero neutrino mass
matrices at long baseline neutrino experiment DUNE. Assuming a diagonal charged
lepton basis and Majorana nature of light neutrinos, we first classify the
possible light neutrino mass matrices with one and two texture zeros and then
numerically evaluate the parameter space in terms of atmospheric mixing angle
$\theta_{23}$ and Dirac CP phase $\delta_{\text{CP}}$ which satisfies the
texture zero conditions. We then feed these parameter values into the numerical
analysis in order to study the sensitivity of DUNE experiment to them. We find
that the DUNE will be able to exclude some of these texture zero mass matrices
which restrict the $(\theta_{23}-\delta_{\text{CP}})$ to a very specific range
of values.


title:
Magnetic avalanches in granular ferromagnets: Thermal activated
  collective behavior

abstract:
  We present a numerical study on the thermal activated avalanche dynamics in
granular materials composed of ferromagnetic clusters embedded in a
non-magnetic matrix. A microscopic dynamical simulation based on the
reaction-diffusion process is developed to modeling the magnetization process
of such systems. The large-scale simulations presented here explicitly
demonstrate inter-granular collective behavior induced by thermal activation of
spin tunneling. In particular, we observe an intriguing criticality controlled
by the rate of energy dissipation. We show that thermal activated avalanches
can be understood in the framework of continuum percolation and the emergent
dissipation induced criticality is in the universality class of
three-dimensional percolation transition. Implications of these results to the
phase-separated states of colossal magnetoresistance materials and other
artificial granular magnetic systems are also~discussed.


title:
Informational and Causal Architecture of Continuous-time Renewal and
  Hidden Semi-Markov Processes

abstract:
  We introduce the minimal maximally predictive models ({\epsilon}-machines) of
processes generated by certain hidden semi-Markov models. Their causal states
are either hybrid discrete-continuous or continuous random variables and
causal-state transitions are described by partial differential equations.
Closed-form expressions are given for statistical complexities, excess
entropies, and differential information anatomy rates. We present a complete
analysis of the {\epsilon}-machines of continuous-time renewal processes and,
then, extend this to processes generated by unifilar hidden semi-Markov models
and semi-Markov models. Our information-theoretic analysis leads to new
expressions for the entropy rate and the rates of related information measures
for these very general continuous-time process classes.

categories: cond-mat.stat-mech cs.IT math.IT math.ST nlin.CD stat.TH


title:
Analysis of a high order Trace Finite Element Method for PDEs on level
  set surfaces

abstract:
  We present a new high order finite element method for the discretization of
partial differential equations on stationary smooth surfaces which are
implicitly described as the zero level of a level set function. The
discretization is based on a trace finite element technique. The higher
discretization accuracy is obtained by using an isoparametric mapping of the
volume mesh, based on the level set function, as introduced in [C. Lehrenfeld,
\emph{High order unfitted finite element methods on level set domains using
isoparametric mappings}, Comp. Meth. Appl. Mech. Engrg. 2016]. The resulting
trace finite element method is easy to implement. We present an error analysis
of this method and derive optimal order $H^1(\Gamma)$-norm error bounds. A
second topic of this paper is a unified analysis of several stabilization
methods for trace finite element methods. Only a stabilization method which is
based on adding an anisotropic diffusion in the volume mesh is able to control
the condition number of the stiffness matrix also for the case of higher order
discretizations. Results of numerical experiments are included which confirm
the theoretical findings on optimal order discretization errors and uniformly
bounded condition numbers.


title: CogALex-V Shared Task: ROOT18

abstract:
  In this paper, we describe ROOT 18, a classifier using the scores of several
unsupervised distributional measures as features to discriminate between
semantically related and unrelated words, and then to classify the related
pairs according to their semantic relation (i.e. synonymy, antonymy, hypernymy,
part-whole meronymy). Our classifier participated in the CogALex-V Shared Task,
showing a solid performance on the first subtask, but a poor performance on the
second subtask. The low scores reported on the second subtask suggest that
distributional measures are not sufficient to discriminate between multiple
semantic relations at once.


title: Montague's Paradox without Necessitation

abstract:
  Some such as Dean (2014) suggest that Montague's paradox requires the
necessitation rule, and that the use of the rule in such a context is
contentious. But here, I show that the paradox arises independently of the
necessitation rule. A derivation of the paradox is given in modal system T
without deploying necessitation; a necessitation-free derivation is also
formulated in a significantly weaker system.


title:
Group factorisations, uniform automorphisms, and permutation groups of
  simple diagonal type

abstract:
  We present a new proof, which is independent of the finite simple group
classification and applies also to infinite groups, that quasiprimitive
permutation groups of simple diagonal type cannot be embedded into wreath
products in product action. The proof uses several deep results that concern
factorisations of direct products involving subdirect subgroups. We find that
such factorisations are controlled by the existence of uniform automorphisms.


title:
Heavy flavour corrections to polarised and unpolarised deep-inelastic
  scattering at 3-loop order

abstract:
  We report on progress in the calculation of 3-loop corrections to the
deep-inelastic structure functions from massive quarks in the asymptotic region
of large momentum transfer $Q^2$. Recently completed results allow us to obtain
the $O(a_s^3)$ contributions to several heavy flavour Wilson coefficients which
enter both polarised and unpolarised structure functions for lepton-nucleon
scattering. In particular, we obtain the non-singlet contributions to the
unpolarised structure functions $F_2(x,Q^2)$ and $x F_3(x,Q^2)$ and the
polarised structure function $g_1(x,Q^2)$. From these results we also obtain
the heavy flavour contributions to the Gross-Llewellyn-Smith and the Bjorken
sum rules.


title: Shared randomness and device-independent dimension witnessing

abstract:
  It has been shown that the conditional probability distributions obtained by
performing measurements on an uncharacterized physical system can be used to
infer its underlying dimension in a device-independent way both in the
classical and quantum setting. We analyze several aspects of the structure of
the sets of probability distributions corresponding to a certain dimension
taking into account whether shared randomness is available as a resource or
not. We first consider the so-called prepare-and-measure scenario. We show that
quantumness and shared randomness are not comparable resources. That is, on the
one hand, there exist behaviours that require a quantum system of arbitrarily
large dimension in order to be observed while they can be reproduced with a
classical physical system of minimal dimension together with shared randomness.
On the other hand, there exist behaviours which require exponentially larger
dimensions classically than quantumly even if the former is supplemented with
shared randomness. We also show that in the absence of shared randomness, the
sets corresponding to a sufficiently small dimension are negligible
(zero-measure and nowhere dense) both classically and quantumly. This is in
sharp contrast to the situation in which this resource is available and
explains the exceptional robustness of dimension witnesses in the setting in
which devices can be taken to be uncorrelated. We finally consider the Bell
scenario in the absence of shared randomness and prove some non-convexity and
negligibility properties of these sets for sufficiently small dimensions. This
shows again the enormous difference induced by the availability or not of this
resource.


title:
Two-dimensional extremely short optical pulses in silicene with random
  electric fields

abstract:
  We investigate an influence of the random external electric field on the 2D
extremely short optical pulses propagation in the silicene. The random electric
field is perpendicular to the silicene plane. An effective equation has the
form of a wave equation with saturating nonlinearity. We analyze the
dependences of the electromagnetic field intensity on the parameters of a
problem.


title: On the regularity of SLE trace

abstract:
  We revisit regularity of SLE trace, for all $\kappa \neq 8$, and establish
Besov regularity under the usual half-space capacity parametrization. With an
embedding theorem of Garsia--Rodemich--Rumsey type, we obtain finite moments
(and hence almost surely) optimal variation regularity with index $\min (1 +
\kappa / 8, 2) $, improving on previous works of Werness, and also (optimal)
H\"older regularity \`a la Johansson Viklund and Lawler.


title:
Wide-Field Strain Imaging with Preferentially-Aligned Nitrogen-Vacancy
  Centers in Polycrystalline Diamond

abstract:
  We report on wide-field optically detected magnetic resonance imaging of
nitrogen-vacancy centers (NVs) in type IIa polycrystalline diamond. These
studies reveal a heterogeneous crystalline environment that produces a varied
density of NV centers, including preferential orientation within some
individual crystal grains, but preserves long spin coherence times. Using the
native NVs as nanoscale sensors, we introduce a 3-dimensional strain imaging
technique with high sensitivity ( $< 10^{-5}$ Hz$^{-1/2}$) and
diffraction-limited resolution across a wide field of view.


title:
From degree-correlated to payoff-correlated activity for an optimal
  resolution of social dilemmas

abstract:
  An active participation of players in evolutionary games depends on several
factors, ranging from personal stakes to the properties of the interaction
network. Diverse activity patterns thus have to be taken into account when
studying the evolution of cooperation in social dilemmas. Here we study the
weak prisoner's dilemma game, where the activity of each player is determined
in a probabilistic manner either by its degree or by its payoff. While
degree-correlated activity introduces cascading failures of cooperation that
are particularly severe on scale-free networks with frequently inactive hubs,
payoff-correlated activity provides a more nuanced activity profile, which
ultimately hinders systemic breakdowns of cooperation. To determine optimal
conditions for the evolution of cooperation, we introduce an exponential decay
to payoff-correlated activity that determines how fast the activity of a player
returns to its default state. We show that there exists an intermediate decay
rate, at which the resolution of the social dilemma is optimal. This can be
explained by the emerging activity patterns of players, where the inactivity of
hubs is compensated effectively by the increased activity of average-degree
players, who through their collective influence in the network sustain a higher
level of cooperation. The sudden drops in the fraction of cooperators observed
with degree-correlated activity therefore vanish, and so does the need for the
lengthy spatiotemporal reorganization of compact cooperative clusters. The
absence of such asymmetric dynamic instabilities thus leads to an optimal
resolution of social dilemmas, especially when the conditions for the evolution
of cooperation are strongly adverse.


title:
Exchange mechanism for electron paramagnetic resonance of individual
  adatoms

abstract:
  We propose a new universal mechanism that makes it possible to drive an
individual atomic spin using a spin polarized scanning tunnel microscope (STM)
with an oscillating electric signal. We show that the combination of the
distance dependent exchange with the magnetic tip and the electrically driven
mechanical oscillation of the surface spins permits to control their quantum
state. Based on a combination of density functional theory and multiplet
calculations, we show that the proposed mechanism is essential to account for
the recently observed electrically driven paramagnetic spin resonance (ESR) of
an individual Fe atom on a MgO/Ag(100) surface. Our findings set the foundation
to deploy the ESR-STM quantum sensing technique to a much broader class of
systems.


title:
The measurement problem is the measurement problem is the measurement
  problem

abstract:
  Recently, it has been stated that single-world interpretations of quantum
theory are logically inconsistent. The claim is derived from contradicting
statements of agents in a setup combining two Wigner's-friend experiments.
Those statements stem from applying the measurement-update rule subjectively,
i.e., only for the respective agent's own measurement. We argue that the
contradiction expresses the incompatibility of collapse and unitarity -
resulting in different formal descriptions of a measurement - and does not
allow to dismiss any specific interpretation of quantum theory.