title:
An equidistribution theorem for holomorphic Siegel modular forms for
  $GSp_4$

abstract:
  We prove an equidistribution theorem for a family of holomorphic Siegel cusp
forms for $GSp_4/\mathbb{Q}$ in various aspects. A main tool is Arthur's
invariant trace formula. While Shin and Shin-Templier used Euler-Poincar\'e
functions at infinity in the formula, we use a pseudo-coefficient of a
holomorphic discrete series to extract holomorphic Siegel cusp forms. Then the
non-semisimple contributions arise from the geometric side, and this provides
new second main terms $A, B_1$ in the main theorem which have not been studied
and a mysterious second term $B_2$ also appears in the second main term coming
from the semisimple elements. Furthermore our explicit study enables us to
treat more general aspects in the weight. We also give several applications
including the vertical Sato-Tate theorem, the unboundedness of Hecke fields and
low-lying zeros for degree 4 spinor $L$-functions and degree 5 standard
$L$-functions of holomorphic Siegel cusp forms.


title: Can the diphoton enhancement at 750 GeV be due to a neutral technipion?

abstract:
  We discuss a scenario in which the diphoton enhancement at $M_{\gamma
\gamma}$ = 750 GeV, observed by the ATLAS and CMS Collaborations, is a neutral
technipion $\tilde{\pi}^0$. We consider two distinct minimal models for the
dynamical electroweak symmetry breaking. In a first one, two-flavor vector-like
technicolor (VTC) model, we assume that the two-photon fusion is a dominant
production mechanism. We include $\gamma \gamma \to {\tilde \pi}^0$ and
production of technipion associated with one or two jets. All the considered
mechanisms give similar contributions. With the strong Yukawa
(technipion-techniquark) coupling $g_{TC}$ = 10 - 20 we obtain the measured
cross section of the "signal". With such values of $g_{TC}$ we get a relatively
small $\Gamma_{\rm tot}$. In a second approach, one-family walking technicolor
(WTC) model, the isoscalar technipion is produced dominantly via the
gluon-gluon fusion. We also discuss the size of the signal at lower energies
(LHC, Tevatron) for $\gamma \gamma$ (VTC) and jet-jet (WTC) final states and
check consistency with the existing experimental data. We predict a measurable
cross section for ${\tilde \pi}^0$ production associated with one or two soft
jets. The technipion signal in both models is compared with the SM background
diphoton contributions. We observe the dominance of inelastic-inelastic
processes for $\gamma \gamma$ induced processes. In the VTC scenario, we
predict the signal cross section for purely exclusive $p p \to p p \gamma
\gamma$ processes at $\sqrt{s}$ = 13 TeV to be about 0.2 fb. Such a cross
section would be, however, difficult to measure with the planned integrated
luminosity. In all considered cases the signal is below the background or/and
below the threshold set by statistics.


title:
Sentence Level Recurrent Topic Model: Letting Topics Speak for
  Themselves

abstract:
  We propose Sentence Level Recurrent Topic Model (SLRTM), a new topic model
that assumes the generation of each word within a sentence to depend on both
the topic of the sentence and the whole history of its preceding words in the
sentence. Different from conventional topic models that largely ignore the
sequential order of words or their topic coherence, SLRTM gives full
characterization to them by using a Recurrent Neural Networks (RNN) based
framework. Experimental results have shown that SLRTM outperforms several
strong baselines on various tasks. Furthermore, SLRTM can automatically
generate sentences given a topic (i.e., topics to sentences), which is a key
technology for real world applications such as personalized short text
conversation.


title:
Natural Connections with Totally Skew-Symmetric Torsion on Manifolds
  with Almost Contact 3-Structure and Metrics of Hermitian-Norden Type

abstract:
  It is considered a differentiable manifold equipped with a pseudo-Riemannian
metric and an almost contact 3-struc\-ture so that an almost contact metric
structure and two almost contact B-metric structures are generated. There are
introduced the so-called associated Nijenhuis tensors for the studied
structures. It is given a geometric interpretation of the vanishing of these
tensors as a necessary and sufficient condition for the existence of linear
connections with totally skew-symmetric torsions preserving the structure. An
example of a 7-dimensional manifold with connections of the considered type is
given.


title:
Topological superconductivity and anti-Shiba states in disordered chains
  of magnetic adatoms

abstract:
  Regular arrays of magnetic atoms on a superconductor provide a promising
platform for topological superconductivity. In this work we study effects of
disorder in these systems, focusing on vacancies realized by missing magnetic
atoms. We develop approaches that allow treatment of ferromagnetic dense chains
as well as long-range hopping ferromagnetic and helical Shiba chains at
arbitrary subgap energies. Vacancies in magnetic chains play an analogous role
to magnetic impurities in a clean $s$-wave superconductor. A single vacancy in
a topological chain gives rise to a low-lying "anti-Shiba" state below the band
edge of a regular magnetic chain. Proliferation of the anti-Shiba band formed
by a finite density of hybridized vacancy states leads to deterioration of the
topological phase, which exhibits unusual fragility in a particular parameter
region in dilute chains. We also consider local fluctuation in the Shiba
coupling and discuss how vacancy states could contribute to experimental
verification of topological superconductivity.


title: Quantum-gravity effects on a Higgs-Yukawa model

abstract:
  A phenomenologically viable theory of quantum gravity must accommodate all
observed matter degrees of freedom and their properties. Here, we explore
whether a toy model of the Higgs-Yukawa sector of the Standard Model is
compatible with asymptotically safe quantum gravity. We discuss the
phenomenological implications of our result in the context of the Standard
Model. We analyze the quantum scaling dimension of the system, and find an
irrelevant Yukawa coupling at a joint gravity-matter fixed point. Further, we
explore the impact of gravity-induced couplings between scalars and fermions,
which are non-vanishing in asymptotically safe gravity.


title:
Increase of quantum volume entropy in presence of degenerate
  eigenenergies

abstract:
  The entropy of a classical thermally isolated Hamiltonian system is given by
the logarithm of the measure of phase space enclosed by the constant energy
hyper-surface, also known as volume entropy. It has been shown that on average
the latter cannot decrease if the initial state is sampled from a classical
passive distribution. Quantum extension of this result has been shown, but only
for systems with a non-degenerate energy spectrum. Here we further extend to
the case of possible degeneracies.

categories: cond-mat.stat-mech math-ph math.MP quant-ph


title: A model for configuration spaces of points

abstract:
  We construct a real combinatorial model for the configuration spaces of
points of compact smooth oriented manifolds without boundary. We use these
models to show that the real homotopy type of configuration spaces of a simply
connected such manifold only depends on the real homotopy type of the manifold.
  Moreover, we show that for framed $D$-dimensional manifolds these models
capture a natural right homotopy action of the little $D$-disks operad.


title:
The super-super exchange mechanism in iron-based antiperovskite
  chalco-halides

abstract:
  By using the first-principles electronic structure calculations, we have
systematically studied the magnetism in three recently synthesized iron-based
antiperovskite chalco-halides: Ba$_3$(FeS$_4$)Cl, Ba$_3$(FeS$_4$)Br, and
Ba$_3$(FeSe$_4$)Br. These compounds consist of edge-sharing Ba$Q_6$ ($Q$=Cl or
Br) octahedra intercalated with isolated Fe$X_4$ ($X$=S or Se) tetrahedra. We
find that even though the shortest distances between the nearest-neighboring Fe
atoms in these three compounds already exceed 6 \AA, much larger than the bond
length of a chemical bonding, they all remarkably show antiferromagnetic (AFM)
coupling along $b$ axis with very weak spin-spin correlation along $a$ axis.
Our study shows that the mechanism underlying this novel AFM coupling is such a
new type of exchange interaction between the nearest-neighboring Fe-based
super-moments mediated by Ba cations, which we call the super-super exchange
interaction, in which each magnetic Fe atom partially polarizes its four
nearest-neighboring $X$ atoms to form a super-moment through $p$-$d$ orbital
hybridization and the $X$ atoms in neighboring Fe$X_4$ tetrahedra along $b$
axis antiferromagnetically couple with each others through the intermediate Ba
cations. Different from the conventional superexchange, here it is cations
rather than anions that mediate two neighboring super-moments. According to the
calculated strength of the AFM coupling, we predict that among these compounds
the highest AFM phase transition temperature $T_N$ may reach 110 K in
Ba$_3$(FeSe$_4$)Br, in comparison with the observed $T_N$s of 84 K in
Ba$_3$(FeS$_4$)Br and 95 K in Ba$_3$(FeS$_4$)Cl.


title:
Heterogeneous diffusion, viscosity and the Stokes Einstein relation in
  binary liquids

abstract:
  We investigate the origin of the breakdown of the Stokes-Einstein relation
(SER) between diffusivity and viscosity in undercooled melts. A binary
Lennard-Jones system, as a model for a metallic melt, is studied by molecular
dynamics. A weak breakdown at high temperatures can be understood from the
collectivization of motion, seen in the isotope effect. The strong breakdown at
lower temperatures is connected to an increase in dynamic heterogeneity. On
relevant timescales some particles diffuse much faster than the average or than
predicted by the SER. The van-Hove self correlation function allows to
unambiguously identify slow particles. Their diffusivity is even less than
predicted by the SER. The time-span of these particles being slow particles,
before their first conversion to be a fast one, is larger than the decay time
of the stress correlation. The contribution of the slow particles to the
viscosity rises rapidly upon cooling. Not only the diffusion but also the
viscosity shows a dynamically heterogeneous scenario. We can define a "slow"
viscosity. The SER is recovered as relation between slow diffusivity and slow
viscosity.


title: Quantum state tomography via reduced density matrices

abstract:
  Quantum state tomography via local measurements is an efficient tool for
characterizing quantum states. However it requires that the original global
state be uniquely determined (UD) by its local reduced density matrices (RDMs).
In this work we demonstrate for the first time a class of states that are UD by
their RDMs under the assumption that the global state is pure, but fail to be
UD in the absence of that assumption. This discovery allows us to classify
quantum states according to their UD properties, with the requirement that each
class be treated distinctly in the practice of simplifying quantum state
tomography. Additionally we experimentally test the feasibility and stability
of performing quantum state tomography via the measurement of local RDMs for
each class. These theoretical and experimental results advance the project of
performing efficient and accurate quantum state tomography in practice.


title:
Canonical correlation analysis of high-dimensional data with very small
  sample support

abstract:
  This paper is concerned with the analysis of correlation between two
high-dimensional data sets when there are only few correlated signal components
but the number of samples is very small, possibly much smaller than the
dimensions of the data. In such a scenario, a principal component analysis
(PCA) rank-reduction preprocessing step is commonly performed before applying
canonical correlation analysis (CCA). We present simple, yet very effective
approaches to the joint model-order selection of the number of dimensions that
should be retained through the PCA step and the number of correlated signals.
These approaches are based on reduced-rank versions of the Bartlett-Lawley
hypothesis test and the minimum description length information-theoretic
criterion. Simulation results show that the techniques perform well for very
small sample sizes even in colored noise.


title: Star formation in Galactic flows

abstract:
  We investigate the triggering of star formation in clouds that form in
Galactic scale flows as the ISM passes through spiral shocks. We use the
Lagrangian nature of SPH simulations to trace how the star forming gas is
gathered into self-gravitating cores that collapse to form stars. Large scale
flows that arise due to Galactic dynamics create shocks of order 30 km/s that
compress the gas and form dense clouds $(n> $several $\times 10^2$ cm$^{-3}$)
in which self-gravity becomes relevant. These large-scale flows are necessary
for creating the dense physical conditions for gravitational collapse and star
formation. Local gravitational collapse requires densities in excess of
$n>10^3$ cm$^{-3}$ which occur on size scales of $\approx 1$ pc for low-mass
star forming regions ($M<100 M_{\odot}$), and up to sizes approaching 10 pc for
higher-mass regions ($M>10^3 M_{\odot}$). Star formation in the 250 pc region
lasts throughout the 5 Myr timescale of the simulation with a star formation
rate of $\approx 10^{-1} M_{\odot}$ yr$^{-1}$ kpc$^{-2}$. In the absence of
feedback, the efficiency of the star formation per free-fall time varies from
our assumed 100 % at our sink accretion radius to values of $< 10^{-3}$ at low
densities.


title: Unions and ideals of locally strongly porous sets

abstract:
  For subsets of $\mathbb R^+ = [0,\infty)$ we introduce a notion of coherently
porous sets as the sets for which the upper limit in the definition of porosity
at a point is attained along the same sequence. We prove that the union of two
strongly porous at $0$ sets is strongly porous if and only if these sets are
coherently porous. This result leads to a characteristic property of the
intersection of all maximal ideals containing in the family of strongly porous
at $0$ subsets of $\mathbb R^+$. It is also shown that the union of a set $A
\subseteq \mathbb R^+$ with arbitrary strongly porous at $0$ subset of $\mathbb
R^+$ is porous at $0$ if and only if $A$ is lower porous at $0$.


title:
Lindblad-Driven Discretized Leads for Non-Equilibrium Steady-State
  Transport in Quantum Impurity Models: Recovering the Continuum Limit

abstract:
  The description of interacting quantum impurity models in steady-state
nonequilibrium is an open challenge for computational many-particle methods:
the numerical requirement of using a finite number of lead levels and the
physical requirement of describing a truly open quantum system are seemingly
incompatible. One possibility to bridge this gap is the use of Lindblad-driven
discretized leads (LDDL): one couples auxiliary continuous reservoirs to the
discretized lead levels and represents these additional reservoirs by Lindblad
terms in the Liouville equation. For quadratic models governed by Lindbladian
dynamics, we present an elementary approach for obtaining correlation functions
analytically. In a second part, we use this approach to explicitly discuss the
conditions under which the continuum limit of the LDDL approach recovers the
correct representation of thermal reservoirs. As an analytically solvable
example, the nonequilibrium resonant level model is studied in greater detail.
Lastly, we present ideas towards a numerical evaluation of the suggested
Lindblad equation for interacting impurities based on matrix product states. In
particular, we present a reformulation of the Lindblad equation, which has the
useful property that the leads can be mapped onto a chain where both the
Hamiltonian dynamics and the Lindblad driving are local at the same time.
Moreover, we discuss the possibility to combine the Lindblad approach with a
logarithmic discretization needed for the exploration of exponentially small
energy scales.


title:
Tracking Changes in Resilience and Level of Coordination in Terrorist
  Groups

abstract:
  Activity profiles of terrorist groups show frequent spurts and downfalls
corresponding to changes in the underlying organizational dynamics. In
particular, it is of interest in understanding changes in attributes such as
intentions/ideology, tactics/strategies, capabilities/resources, etc., that
influence and impact the activity. The goal of this work is the quick detection
of such changes and in general, tracking of macroscopic as well as microscopic
trends in group dynamics. Prior work in this area are based on parametric
approaches and rely on time-series analysis techniques, self-exciting hurdle
models (SEHM), or hidden Markov models (HMM). While these approaches detect
spurts and downfalls reasonably accurately, they are all based on model
learning --- a task that is difficult in practice because of the "rare" nature
of terrorist attacks from a model learning perspective. In this paper, we
pursue an alternate non-parametric approach for spurt detection in activity
profiles. Our approach is based on binning the count data of terrorist activity
to form observation vectors that can be compared with each other. Motivated by
a majorization theory framework, these vectors are then transformed via certain
functionals and used in spurt classification. While the parametric approaches
often result in either a large number of missed detections of real changes or
false alarms of unoccurred changes, the proposed approach is shown to result in
a small number of missed detections and false alarms. Further, the
non-parametric nature of the approach makes it attractive for ready
applications in a practical context.


title: Elastocapillarity: Surface Tension and the Mechanics of Soft Solids

abstract:
  It is widely appreciated that surface tension can dominate the behavior of
liquids at small scales. Solids also have surface stresses of a similar
magnitude, but they are usually overlooked. However, recent work has shown that
these can play an central role in the mechanics of soft solids such as gels.
Here, we review this emerging field. We outline the theory of surface stresses,
from both mechanical and thermodynamic perspectives, emphasizing the
relationship between surface stress and surface energy. We describe a wide
range of phenomena at interfaces and contact lines where surface stresses play
an important role. We highlight how surface stresses causes dramatic departures
from classic theories for wetting (Young-Dupr\'{e}), adhesion
(Johnson-Kendall-Roberts), and composites (Eshelby). A common thread is the
importance of the ratio of surface stress to an elastic modulus, which defines
a length scale below which surface stresses can dominate.


title:
Strong convergence of full-discrete nonlinearity-truncated accelerated
  exponential Euler-type approximations for stochastic Kuramoto-Sivashinsky
  equations

abstract:
  This article introduces and analyzes a new explicit, easily implementable,
and full discrete accelerated exponential Euler-type approximation scheme for
additive space-time white noise driven stochastic partial differential
equations (SPDEs) with possibly non-globally monotone nonlinearities such as
stochastic Kuramoto-Sivashinsky equations. The main result of this article
proves that the proposed approximation scheme converges strongly and
numerically weakly to the solution process of such an SPDE. Key ingredients in
the proof of our convergence result are a suitable generalized coercivity-type
condition, the specific design of the accelerated exponential Euler-type
approximation scheme, and an application of Fernique's theorem.


title: Limiting Spurious Flow in Simulations of Electrokinetic Phenomena

abstract:
  Electrokinetic transport phenomena can strongly influence the behaviour of
macromolecules and colloidal particles in solution, with applications in, e.g.,
DNA translocation through nanopores, electro-osmotic flow in nanocapillaries,
and electrophoresis of charged macromolecules. Numerical simulations are an
important tool to investigate these electrokinetic phenomena, but are often
plagued by spurious fluxes and spurious flows that can easily exceed physical
fluxes and flows. Here, we present a method that reduces one of these spurious
currents, spurious flow, by several orders of magnitude. We demonstrate the
effectiveness and generality of our method for both electrokinetic
lattice-Boltzmann and finite-element-method based algorithms by simulating a
charged sphere in an electrolyte solution, and flow through a nanopore. We also
show that previous attempts to suppress these spurious currents introduce other
sources of error.


title:
Probing the 2D temperature structure of protoplanetary disks with
  Herschel observations of high-J CO lines

abstract:
  The gas temperature structure of protoplanetary disks is a key ingredient for
interpreting various disk observations and for quantifying the subsequent
evolution of these systems. The comparison of low- and mid-$J$ CO rotational
lines is a powerful tool to assess the temperature gradient in the warm
molecular layer of disks. Spectrally resolved high-$J$ ($J_{\rm u} > 14$) CO
lines probe intermediate distances and heights from the star that are not
sampled by (sub-)millimeter CO spectroscopy. This paper presents new {\it
Herschel}/HIFI and archival PACS observations of $^{12}$CO, $^{13}$CO and \cii
\ emission in 4 Herbig AeBe (HD 100546, HD 97048, IRS 48, HD 163296) and 3 T
Tauri (AS 205, S CrA, TW Hya) disks. In the case of the T Tauri systems AS 205
and S CrA, the CO emission has a single-peaked profile, likely due to a slow
wind. For all other systems, the {\it Herschel} CO spectra are consistent with
pure disk emission and the spectrally-resolved lines (HIFI) and the CO
rotational ladder (PACS) are analyzed simultaneously assuming power-law
temperature and column density profiles, using the velocity profile to locate
the emission in the disk. The temperature profile varies substantially from
disk to disk. In particular, $T_{\rm gas}$ in the disk surface layers can
differ by up to an order of magnitude among the 4 Herbig AeBe systems with HD
100546 being the hottest and HD 163296 the coldest disk of the sample. Clear
evidence of a warm disk layer where $T_{\rm gas} > T_{\rm dust}$ is found in
all the Herbig Ae disks. The observed CO fluxes and line profiles are compared
to predictions of physical-chemical models. The primary parameters affecting
the disk temperature structure are the flaring angle, the gas-to-dust mass
ratio the scale height and the dust settling.


title:
An enhanced rate of tidal disruptions in the centrally overdense E+A
  galaxy NGC 3156

abstract:
  Time domain optical surveys have discovered roughly a dozen candidate stellar
tidal disruption flares in the last five years, and future surveys like the
{\it Large Synoptic Survey Telescope} will likely find hundreds to thousands
more. These tidal disruption events (TDEs) present an interesting puzzle: a
majority of the current TDE sample is hosted by rare post-starburst galaxies,
and tens of percent are hosted in even rarer E+A galaxies, which make up $\sim
0.1\%$ of all galaxies in the local universe. E+As are therefore
overrepresented among TDE hosts by 1-2 orders of magnitude, a discrepancy
unlikely to be accounted for by selection effects. We analyze {\it Hubble Space
Telescope} photometry of one of the nearest E+A galaxies, NGC~3156, to estimate
the rate of stellar tidal disruption produced as two-body relaxation diffuses
stars onto orbits in the loss cone of the central supermassive black hole. The
rate of TDEs produced by two-body relaxation in NGC~3156 is large when compared
to other galaxies with similar black hole mass: $\dot{N}_{\rm TDE}\sim 1\times
10^{-3}~{\rm yr}^{-1}$. This suggests that the preference of TDEs for E+A hosts
may be due to central stellar overdensities produced in recent starbursts.


title: Alpha Virginis: line-profile variations and orbital elements

abstract:
  Abridged: Alpha Virginis is a binary system whose proximity and brightness
allow detailed investigations of the internal structure and evolution of stars
undergoing time-variable tidal interactions. Previous studies have led to the
conclusion that the internal structure of Spica's primary star may be more
centrally condensed than predicted by theoretical models of single stars,
raising the possibility that the interactions could lead to effects that are
currently neglected in structure and evolution calculations. The key parameters
in confirming this result are the values of the orbital eccentricity $e$, the
apsidal period $U$, and the primary star's radius, R_1. We analyze the impact
that line profile variability has on the derivation of its orbital elements and
R_1. We use high SNR observations obtained in 2000, 2008, and 2013 to derive
the orbital elements from fits to the radial velocity curves. We produce
synthetic line profiles using an ab initio tidal interaction model. Results:
The variations in the line profiles can be understood in terms of the tidal
flows, whose large-scale structure is relatively fixed in the rotating binary
system reference frame. Fits to the radial velocity curves yield
$e$=0.108$\pm$0.014. However, the analogous RV curves from theoretical line
profiles indicate that the distortion in the lines causes the fitted value of
$e$ to depend on the argument of periastron; i.e., on the epoch of observation.
As a result, the actual value of $e$ may be as high as 0.125. We find that
$U$=117.9$\pm$1.8, which is in agreement with previous determinations. Using
the value $R_1=6.8 R_\odot$ derived by Palate et al. (2013) the value of the
observational internal structure constant $k_{2,obs}$ is consistent with
theory. We confirm the presence of variability in the line profiles of the
secondary star.


title:
Sufficient Conditions for Existence of $J_{\alpha}(X +
  \sqrt[\alpha]{\eta}N)$

abstract:
  In his technical report~\cite[sec. 6]{barrontech}, Barron states that the de
Bruijn's identity for Gaussian perturbations holds for any RV having a finite
variance. In this report, we follow Barron's steps as we prove the existence of
$J_{\alpha}\left(X + \sqrt[\alpha]{\eta}N\right)$, $\eta > 0$ for any Radom
Variable (RV) $X \in \mathcal{L}$ where \begin{equation*} \mathcal{L} = \left\{
\text{RVs} \,\,U: \int \ln\left(1 + |U|\right)\,dF_{U}(u) \text{ is finite }
\right\}, \end{equation*} and where $N \sim \mathcal{S}(\alpha;1)$ is
independent of $X$, $0< \alpha <2$.


title: A refined energy bound for perpendicular bisectors

abstract:
  Let $\mathcal{P}$ be a set of $n$ points in the Euclidean plane. We prove
that, for any $\epsilon > 0$, either a single line or circle contains $n/2$
points of $\mathcal{P}$, or the number of distinct perpendicular bisectors
determined by pairs of points in $\mathcal{P}$ is $\Omega(n^{52/35 -
\epsilon})$, where the constant implied by the $\Omega$ notation depends on
$\mathcal{P}$. This is progress toward a conjecture of Lund, Sheffer, and de
Zeeuw, that either a single line or circle contains $n/2$ points of
$\mathcal{P}$, or the number of distinct perpendicular bisectors is
$\Omega(n^2)$.
  The proof relies bounding the size of a carefully selected subset of the
quadruples $(a,b,c,d) \in \mathcal{P}^4$ such that the perpendicular bisector
of $a$ and $b$ is the same as the perpendicular bisector of $c$ and $d$.


title:
Real-space imaging of a topological protected edge state with ultracold
  atoms in an amplitude-chirped optical lattice

abstract:
  Topological states of matter, as quantum Hall systems or topological
insulators, cannot be distinguished from ordinary matter by local measurements
in the bulk of the material. Instead, global measurements are required,
revealing topological invariants as the Chern number. At the heart of
topological materials are topologically protected edge states that occur at the
intersection between regions of different topological order. Ultracold atomic
gases in optical lattices are promising new platforms for topological states of
matter, though the observation of edge states has so far been restricted in
these systems to the state space imposed by the internal atomic structure. Here
we report on the observation of an edge state between two topological distinct
phases of an atomic physics system in real space using optical microscopy. An
interface between two spatial regions of different topological order is
realized in a one-dimensional optical lattice of spatially chirped amplitude.
To reach this, a magnetic field gradient causes a spatial variation of the
Raman detuning in an atomic rubidium three- level system and a corresponding
spatial variation of the coupling between momentum eigenstates. This novel
experimental technique realizes a cold atom system described by a Dirac
equation with an inhomogeneous mass term closely related to the SSH-model. The
observed edge state is characterized by measuring the overlap to various
initial states, revealing that this topological state has singlet nature in
contrast to the other system eigenstates, which occur pairwise. We also
determine the size of the energy gap to the adjacent eigenstate doublet. Our
findings hold prospects for the spectroscopy of surface states in topological
matter and for the quantum simulation of interacting Dirac systems.


title:
On a Class of Non-self-adjoint Multidimensional Periodic Schrodinger
  Operators

abstract:
  We investigate the multidimensional Schrodinger operator L(q) with
complex-valued periodic, with respect to a lattice, potential q when the
Fourier coefficients of q with respect to the orthogonal system {exp(i(a,x))},
where a changes in the dual lattice, vanish if a belong to a half-space We
prove that the Bloch eigenvalues of L(q) and of the free operator L(0) are the
same and find explicit formulas for the Bloch functions. It implies that the
Fermi surfaces of L(q) and L(0) are the same. The considered set of operators
includes a large class of PT symmetric operators used in the PT symmetric
quantum theory.


title: Polarization of Cosmic Microwave Background

abstract:
  In this work we present an extension of the ROMA map-making code for data
analysis of Cosmic Microwave Background polarization, with particular attention
given to the inflationary polarization B-modes. The new algorithm takes into
account a possible cross-correlated noise component among the different
detectors of a CMB experiment. We tested the code on the observational data of
the BOOMERanG (2003) experiment and we show that we are provided with a better
estimate of the power spectra, in particular the error bars of the BB spectrum
are smaller up to 20% for low multipoles. We point out the general validity of
the new method. A possible future application is the LSPE balloon experiment,
devoted to the observation of polarization at large angular scales.


title: On the Combinatorics of the Universal Enveloping Algebra Uh(sl2)

abstract:
  We study using combinatorial methods the structural coefficients of the
formal homogeneous universal enveloping algebra Uh(sl2) of the special linear
algebra sl2 over a field of characteristic zero. We provide explicit formulae
for the product of generic elements in Uh(sl2), and construct combinatorial
objects giving flesh to these formulae.


title:
Stochastic Allen-Cahn approximation of the mean curvature flow: large
  deviations upper bound

abstract:
  Consider the Allen-Cahn equation on the $d$-dimensional torus, $d=2,3$, in
the sharp interface limit. As it is well known, the limiting dynamics is
described by the motion by mean curvature of the interface between the two
stable phases. Here, we analyze a stochastic perturbation of the Allen-Cahn
equation and describe its large deviation asymptotics in a joint sharp
interface and small noise limit. Relying on previous results on the variational
convergence of the action functional, we prove the large deviation upper bound.
The corresponding rate function is finite only when there exists a time
evolving interface of codimension one between the two stable phases. The zero
level set of this rate function is given by the evolution by mean curvature in
the sense of Brakke. Finally, the rate function can be written in terms of the
sum of two non-negative quantities: the first measures how much the velocity of
the interface deviates from its mean curvature, while the second is due to the
possible occurrence of nucleation events.


title: Mapping Seyfert and LINER Excitation Modes in the Inner kpc of NGC 3393

abstract:
  We have mapped the extended narrow line region (ENLR) of NGC 3393 on scales
of $r\lesssim4^{\prime\prime}$ ($\sim1\,$kpc) from the nucleus using emission
line images of H$\alpha\,\lambda6563$, [O III]$\lambda5007$, and [S
II]$\lambda\lambda6717,6731$ taken with HST as part of the CHandra survey of
Extended Emission line Regions in nearby Seyfert galaxies (CHEERS). By mapping
these lines onto a spatially resolved Baldwin-Phillips-Terlevich (BPT) diagram,
we investigate the impact of feedback from a Compton-thick AGN on its
circumnuclear ISM. We find the expected Seyfert-like emission within the
ionization bicone ($\lesssim3^{\prime\prime}$; 770 pc). We also find a new,
figure 8 shaped LINER cocoon enveloping the bicone and defining a sharp
($\lesssim100\;$pc) transition between higher and lower ionization zones. These
data illustrate the morphological dependence of ionization states of the ENLR
relative to bicone and host gas geometries.


title: Lyman-alpha blobs: polarization arising from cold accretion

abstract:
  Lyman-$\alpha$ nebulae are usually found in massive environments at high
redshift ($z > 2$). The origin of their Lyman-$\alpha$ (Lya) emission remains
debated. Recent polarimetric observations showed that at least some Lya sources
are polarized. This is often interpreted as a proof that the photons are
centrally produced, and opposed to the scenario in which the Lya emission is
the cooling radiation emitted by gas heated during the accretion onto the halo.
We suggest that this scenario is not incompatible with the polarimetric
observations. In order to test this idea, we post-process a radiative
hydrodynamics simulation of a blob with the MCLya Monte Carlo transfer code. We
compute radial profiles for the surface brightness and the degree of
polarization and compare them to existing observations. We find that both are
consistent with a significant contribution of the extragalactic gas to the Lya
emission. Most of the photons are centrally emitted and scattered inside the
filament afterwards, producing the observed high level of polarization. We
argue that the contribution of the extragalactic gas to the Lya emission does
not prevent polarization to arise. On the contrary, we find that pure galactic
emission causes the polarization profile to be too steep to be consistent with
observations.


title:
Higher moments of arithmetic functions in short intervals: a geometric
  perspective

abstract:
  We study the geometry associated to the distribution of certain arithmetic
functions, including the von Mangoldt function and the M\"obius function, in
short intervals of polynomials over a finite field $\mathbb{F}_q$. Using the
Grothendieck-Lefschetz trace formula, we reinterpret each moment of these
distributions as a point-counting problem on a highly singular complete
intersection variety. We compute part of the $\ell$-adic cohomology of these
varieties, corresponding to an asymptotic bound on each moment for fixed degree
$n$ in the limit as $q \to \infty$. The results of this paper can be viewed as
a geometric explanation for asymptotic results that can be proved using
analytic number theory over function fields.


title: Temperature and high fluence induced ripple rotation on Si(100) surface

abstract:
  Topography evolution of Si(100) surface due to oblique incidence low energy
ion beam sputtering (IBS) is investigated. Experiments were carried out at
different elevated temperatures from 20$^{\circ}$C to 450$^{\circ}$C and at
each temperature, the ion fluence is systematically varied in a wide range from
$\sim$ 1$\times$10$^{18}$cm$^{-2}$ to 1$\times$10$^{20}$cm$^{-2}$. The ion
sputtered surface morphologies are characterized by atomic force microscopy and
high-resolution cross-sectional transmission electron microscopy. At room
temperature, the ion sputtered surfaces show periodic ripple nanopatterns and
their wave-vector remains parallel to ion beam projection for entire fluence
range. With increase of substrate temperature, these patterns tend to demolish
and reduce into randomly ordered mound-like structures around 350$^{\circ}$C.
Further rise in temperature above 400$^{\circ}$C leads, surprisingly,
orthogonally rotated ripples beyond fluence 5$\times$10$^{19}$cm$^{-2}$. All
the results are discussed combining the theoretical framework of linear,
non-linear and recently developed mass redistribution continuum models of
pattern formation by IBS. These results have technological importance regarding
the control over ion induced pattern formation as well as it provides useful
information for further progress in theoretical field.


title:
Synergy between measurements of the gravitational wave and the triple
  Higgs coupling in probing first order phase transition

abstract:
  Probing the Higgs potential and new physics behind the electroweak symmetry
breaking is one of the most important issues of particle physics. In
particular, nature of electroweak phase transition is essential for
understanding physics at the early Universe, such that the strongly first order
phase transition is required for a successful scenario of electroweak
baryogenesis. The strongly first order phase transition is expected to be
tested by precisely measuring the triple Higgs boson coupling at future
colliders like the International Linear Collider. It can also be explored via
the spectrum of stochastic gravitational waves to be measured at future
space-based interferometers such as eLISA and DECIGO. We discuss
complementarity of both the methods in testing the strongly first order phase
transition of the electroweak symmetry in models with additional isospin
singlet scalar fields with and without classical scale invariance. We find that
they are synergetic in identifying specific models of electroweak symmetry
breaking in more details.


title:
Coupling hydrodynamics and radiation calculations for star-jet
  interactions in AGN

abstract:
  Stars and their winds can contribute to the non-thermal (NT) emission in
extragalactic jets. Given the complexity of jet-star interactions, the
properties of the resulting emission are strongly linked to those of the
emitting flows. We simulate the interaction between a stellar wind and a
relativistic extragalactic jet and use the hydrodynamic results to compute the
NT emission under different conditions. We perform relativistic axisymmetric
hydrodynamical simulations of a relativistic jet interacting with a supersonic,
non-relativistic stellar wind. We compute the corresponding streamlines out of
the simulation results, and calculate the injection, evolution, and emission of
NT particles accelerated in the jet shock, focusing on electrons or
$e^\pm$-pairs. Several cases are explored, considering different jet-star
interaction locations, magnetic fields and observer lines of sight. The jet
luminosity and star properties are fixed, but the results are easily scalable
under changes of these parameters. Individual jet-star interactions produce
synchrotron and inverse Compton (IC) emission that peaks from X-rays to MeV
energies (depending on the magnetic field), and at $\sim 100-1000$ GeV
(depending on the stellar type), respectively. The radiation spectrum is hard
in the scenarios explored here due to non-radiative cooling dominance, as
low-energy electrons are efficiently advected even under relatively high
magnetic fields. Interactions of jets with cold stars lead to an even harder IC
spectrum because of the Klein-Nishina effect in the cross-section. Doppler
boosting has a strong impact on the observer luminosity. The emission levels
for individual interactions found here are in the line of previous, more
approximate, estimates, strengthening the hypothesis that collective jet-star
interactions could significantly contribute at high energies under efficient
particle acceleration.


title:
Scalable and interpretable product recommendations via overlapping
  co-clustering

abstract:
  We consider the problem of generating interpretable recommendations by
identifying overlapping co-clusters of clients and products, based only on
positive or implicit feedback. Our approach is applicable on very large
datasets because it exhibits almost linear complexity in the input examples and
the number of co-clusters. We show, both on real industrial data and on
publicly available datasets, that the recommendation accuracy of our algorithm
is competitive to that of state-of-art matrix factorization techniques. In
addition, our technique has the advantage of offering recommendations that are
textually and visually interpretable. Finally, we examine how to implement our
technique efficiently on Graphical Processing Units (GPUs).


title:
MIGA: Combining laser and matter wave interferometry for mass
  distribution monitoring and advanced geodesy

abstract:
  The Matter-Wave laser Interferometer Gravitation Antenna, MIGA, will be a
hybrid instrument composed of a network of atom interferometers horizontally
aligned and interrogated by the resonant field of an optical cavity. This
detector will provide measurements of sub Hertz variations of the gravitational
strain tensor. MIGA will bring new methods for geophysics for the
characterization of spatial and temporal variations of the local gravity field
and will also be a demonstrator for future low frequency Gravitational Wave
(GW) detections. MIGA will enable a better understanding of the coupling at low
frequency between these different signals. The detector will be installed
underground in Rustrel (FR), at the "Laboratoire Souterrain Bas Bruit" (LSBB),
a facility with exceptionally low environmental noise and located far away from
major sources of anthropogenic disturbances. We give in this paper an overview
of the operating mode and status of the instrument before detailing simulations
of the gravitational background noise at the MIGA installation site.

categories: physics.atom-ph gr-qc physics.geo-ph physics.ins-det


title: Codimension two CR singular submanifolds and extensions of CR functions

abstract:
  Let $M \subset {\mathbb{C}}^{n+1}$, $n \geq 2$, be a real codimension two CR
singular real-analytic submanifold that is nondegenerate and holomorphically
flat. We prove that every real-analytic function on $M$ that is CR outside the
CR singularities extends to a holomorphic function in a neighborhood of $M$.
Our motivation is to prove the following analogue of the Hartogs-Bochner
theorem. Let $\Omega \subset {\mathbb{C}}^n \times {\mathbb{R}}$, $n \geq 2$,
be a bounded domain with a connected real-analytic boundary such that $\partial
\Omega$ has only nondegenerate CR singularities. We prove that if $f \colon
\partial \Omega \to {\mathbb{C}}$ is a real-analytic function that is CR at CR
points of $\partial \Omega$, then $f$ extends to a holomorphic function on a
neighborhood of $\overline{\Omega}$ in ${\mathbb{C}}^n \times {\mathbb{C}}$.


title:
Order reduction, projectability and constraints of second-order field
  theories and higher-order mechanics

abstract:
  The projectability of Poincar\'e-Cartan forms in a third-order jet bundle
$J^3\pi$ onto a lower-order jet bundle is a consequence of the degenerate
character of the corresponding Lagrangian. This fact is analyzed using the
constraint algorithm for the associated Euler-Lagrange equations in $J^3\pi$.
The results are applied to study the Hilbert Lagrangian for the Einstein
equations (in vacuum) from a multisymplectic point of view. Thus we show how
these equations are a consequence of the application of the constraint
algorithm to the geometric field equations, meanwhile the other constraints are
related with the fact that this second-order theory is equivalent to a
first-order theory. Furthermore, the case of higher-order mechanics is also
studied as a particular situation.


title: On the Kauffman bracket skein module of the 3-torus

abstract:
  Carrega has shown that the Kauffman bracket skein module of the 3-torus over
the field of rational functions in the variable A can be generated by 9 skein
elements. We show this set of generators is linearly independent.


title: Searching for the HR 8799 Debris Disk with HST/STIS

abstract:
  We present a new algorithm for space telescope high contrast imaging of
close-to-face-on planetary disks called Optimized Spatially Filtered (OSFi)
normalization. This algorithm is used on HR 8799 Hubble Space Telescope (HST)
coronagraphic archival data, showing an over-luminosity after reference star
point spread function (PSF) subtraction that may be from the inner disk and/or
planetesimal belt components of this system. The PSF-subtracted radial profiles
in two separate epochs from 2011 and 2012 are consistent with one another, and
self-subtraction shows no residual in both epochs. We explore a number of
possible false-positive scenarios that could explain this residual flux,
including telescope breathing, spectral differences between HR 8799 and the
reference star, imaging of the known warm inner disk component, OSFi algorithm
throughput and consistency with the standard spider normalization HST PSF
subtraction technique, and coronagraph misalignment from pointing accuracy. In
comparison to another similar STIS dataset, we find that the over-luminosity is
likely a result of telescope breathing and spectral difference between HR 8799
and the reference star. Thus, assuming a non-detection, we derive upper limits
on the HR 8799 dust belt mass in small grains. In this scenario, we find that
the flux of these micron-sized dust grains leaving the system due to radiation
pressure is small enough to be consistent with measurements of other debris
disk halos.


title: The geometry of C_60: a rigorous approach via Molecular Mechanics

abstract:
  Molecular Mechanics describes molecules as particle configurations
interacting via classical potentials. These {\it configurational energies}
usually consist of the sum of different phenomenological terms which are
tailored to the description of specific bonding geometries. This approach is
followed here to model the fullerene $C_{60}$, an allotrope of carbon
corresponding to a specific hollow spherical structure of sixty atoms. We
rigorously address different modeling options and advance a set of minimal
requirements on the configurational energy able to deliver an accurate
prediction of the fine three-dimensional geometry of $C_{60}$ as well as of its
remarkable stability. In particular, the experimentally observed
truncated-icosahedron structure with two different bond lengths is shown to be
a strict local minimizer.

categories: cond-mat.mtrl-sci math-ph math.AP math.MP


title: Graded twisting of comodule algebras and module categories

abstract:
  Continuing our previous work on graded twisting of Hopf algebras and monoidal
categories, we introduce a graded twisting construction for equivariant
comodule algebras and module categories. As an example we study actions of
quantum subgroups of $G\subset SL_{-1}(2)$ on $K_{-1}[x,y]$ and show that in
most cases the corresponding invariant rings $K_{-1}[x,y]^G$ are invariant
rings $K[x,y]^{G'}$ for the action of a classical subgroup $G'\subset SL(2)$.
As another example we study Poisson boundaries of graded twisted categories and
show that under the assumption of weak amenability they are graded twistings of
the Poisson boundaries.


title:
Magnon-mediated spin current noise in ferromagnet$|$non-magnetic
  conductor hybrids

abstract:
  The quantum excitations of the collective magnetization dynamics in a
ferromagnet (F) - magnons - enable spin transport without an associated charge
current. This pure spin current can be transferred to electrons in an adjacent
non-magnetic conductor (N). We evaluate the finite temperature noise of the
magnon-mediated spin current injected into N by an adjacent F driven by a
coherent microwave field. We find that the dipolar interaction leads to
squeezing of the magnon modes giving them wavevector dependent non-integral
spin, which directly manifests itself in the shot noise. For temperatures
higher than the magnon gap, the thermal noise is dominated by large wavevector
magnons which exhibit negligible squeezing. The noise spectrum is white up to
the frequency corresponding to the maximum of the temperature or the magnon
gap. At larger frequencies, the noise is dominated by vacuum fluctuations. The
shot noise is found to be much larger than its thermal counterpart over a broad
temperature range, making the former easier to be measured experimentally.


title:
Planning with Information-Processing Constraints and Model Uncertainty
  in Markov Decision Processes

abstract:
  Information-theoretic principles for learning and acting have been proposed
to solve particular classes of Markov Decision Problems. Mathematically, such
approaches are governed by a variational free energy principle and allow
solving MDP planning problems with information-processing constraints expressed
in terms of a Kullback-Leibler divergence with respect to a reference
distribution. Here we consider a generalization of such MDP planners by taking
model uncertainty into account. As model uncertainty can also be formalized as
an information-processing constraint, we can derive a unified solution from a
single generalized variational principle. We provide a generalized value
iteration scheme together with a convergence proof. As limit cases, this
generalized scheme includes standard value iteration with a known model,
Bayesian MDP planning, and robust planning. We demonstrate the benefits of this
approach in a grid world simulation.


title: Analysis of a Living Fluid Continuum Model

abstract:
  Generalized Navier-Stokes equations which were proposed recently to describe
active turbulence in living fluids are analyzed rigorously. Results on
wellposedness and stability in the $L^2(\mathbb{R}^n)$-setting are derived. Due
to the presence of a Swift-Hohenberg term global wellposedness in a strong
setting for arbitrary initial data in $L^2_\sigma(\mathbb{R}^n)$ is available.
Based on the existence of global strong solutions, results on linear and
nonlinear (in-) stability for the disordered steady state and the manifold of
ordered polar steady states are derived, depending on the involved parameters.


title:
From the Flamm-Einstein-Rosen bridge to the modern renaissance of
  traversable wormholes

abstract:
  We consider the possibility of multiply-connected spacetimes, ranging from
the Flamm-Einstein-Rosen bridge, geons, and the modern renaissance of
traversable wormholes. A fundamental property in wormhole physics is the
flaring-out condition of the throat, which through the Einstein field equation
entails the violation of the null energy condition. In the context of modified
theories of gravity, it has also been shown that the normal matter can be
imposed to satisfy the energy conditions, and it is the higher order curvature
terms, interpreted as a gravitational fluid, that sustain these non-standard
wormhole geometries, fundamentally different from their counterparts in general
relativity. We explore interesting features of these geometries, in particular,
the physical properties and characteristics of these `exotic spacetimes'.


title:
Some remarks on wheeled autonomous vehicles and the evolution of their
  control design

abstract:
  Recent investigations on the longitudinal and lateral control of wheeled
autonomous vehicles are reported. Flatness-based techniques are first
introduced via a simplified model. It depends on some physical parameters, like
cornering stiffness coefficients of the tires, friction coefficient of the
road, ..., which are notoriously difficult to identify. Then a model-free
control strategy, which exploits the flat outputs, is proposed. Those outputs
also depend on physical parameters which are poorly known, i.e., the vehicle
mass and inertia and the position of the center of gravity. A totally
model-free control law is therefore adopted. It employs natural output
variables, namely the longitudinal velocity and the lateral deviation of the
vehicle. This last method, which is easily understandable and implementable,
ensures a robust trajectory tracking problem in both longitudinal and lateral
dynamics. Several convincing computer simulations are displayed.


title:
Estimates of crystalline LiF thermal conductivity at high temperature
  and pressure by a Green-Kubo method

abstract:
  Given the unique optical properties of LiF, it is often used as an
observation window in high-temperature and pressure experiments; and, hence,
estimates of its transmission properties are necessary to interpret
observations. Since direct measurements of the thermal conductivity of LiF at
the appropriate conditions are difficult, we resort to molecular simulation
methods. Using the Belonoshko et al. (2000) empirical potential validated
against ab initio phonon density of states, we estimate the thermal
conductivity of LiF at high temperatures (1000-4000K) and pressures (100-400
GPa) with the Green-Kubo method. We also compare these estimates to those
derived directly from ab initio data. To ascertain the correct phase of LiF at
these extreme conditions we calculate the (relative) phase stability of the B1
and B2 structures using a quasiharmonic ab initio model of the free energy. We
also estimate the thermal conductivity of LiF in an uniaxial loading state that
emulates initial stages of compression in high-stress ramp loading experiments
and show the degree of anisotropy induced in the conductivity due to
deformation.


title:
A robust autoassociative memory with coupled networks of Kuramoto-type
  oscillators

abstract:
  Uncertain recognition success, unfavorable scaling of connection complexity
or dependence on complex external input impair the usefulness of current
oscillatory neural networks for pattern recognition or restrict technical
realizations to small networks. We propose a new network architecture of
coupled oscillators for pattern recognition which shows none of the mentioned
aws. Furthermore we illustrate the recognition process with simulation results
and analyze the new dynamics analytically: Possible output patterns are
isolated attractors of the system. Additionally, simple criteria for
recognition success are derived from a lower bound on the basins of attraction.


title:
Inhabitation in Simply-Typed Lambda-Calculus through a Lambda-Calculus
  for Proof Search

abstract:
  A new, comprehensive approach to inhabitation problems in simply-typed
lambda-calculus is shown, dealing with both decision and counting problems.
This approach works by exploiting a representation of the search space
generated by a given inhabitation problem, which is in terms of a
lambda-calculus for proof search that the authors developed recently. The
representation may be seen as extending the Curry-Howard representation of
proofs by lambda-terms, staying within the methods of lambda-calculus and type
systems. Our methodology reveals inductive descriptions of the decision
problems, driven by the syntax of the proof-search expressions, and the end
products are simple, recursive decision procedures and counting functions.


title: A quantitative Oppenheim Theorem for generic diagonal quadratic forms

abstract:
  We establish a quantitative version of Oppenheim's conjecture for generic
ternary indefinite quadratic forms using an analytic number theory approach.
The statements come with power gains and in some cases are essentially optimal


title: Max k-cut and the smallest eigenvalue

abstract:
  Let $G$ be a graph of order $n$ and size $m$, and let $\mathrm{mc}_{k}\left(
G\right) $ be the maximum size of a $k$-cut of $G.$ It is shown that \[
\mathrm{mc}_{k}\left( G\right) \leq\frac{k-1}{k}\left( m-\frac{\mu_{\min
}\left( G\right) n}{2}\right) , \] where $\mu_{\min}\left( G\right) $ is the
smallest eigenvalue of the adjacency matrix of $G.$
  An infinite class of graphs forcing equality in this bound is constructed.


title: Exactly soluble model of boundary degeneracy

abstract:
  We investigate the topological degeneracy that can be realized in Abelian
fractional quantum spin Hall states with multiply connected gapped boundaries.
Such a topological degeneracy (also dubbed as "boundary degeneracy") does not
require superconducting proximity effect and can be created by simply applying
a depletion gate to the quantum spin Hall material and using a generic
spin-mixing term (e.g., due to backscattering) to gap out the edge modes. We
construct an exactly soluble microscopic model manifesting this topological
degeneracy and solve it using the recently developed technique [S. Ganeshan and
M. Levin, Phys. Rev. B 93, 075118 (2016)]. The corresponding string operators
spanning this degeneracy are explicitly calculated. It is argued that the
proposed scheme is experimentally reasonable.


title: Representing uncertainty on model analysis plots

abstract:
  Model analysis provides a mechanism for representing student learning as
measured by standard multiple-choice surveys. The model plot contains
information regarding both how likely students in a particular class are to
choose the correct answer and how likely they are to choose an answer
consistent with a well-documented conceptual model. Unfortunately Bao's
original presentation of the model plot did not include a way to represent
uncertainty in these measurements. I present details of a method to add error
bars to model plots by expanding the work of Sommer and Lindell. I also provide
a template for generating model plots with error bars.


title: Long, partial-short, and special conformal fields

abstract:
  In the framework of metric-like approach, totally symmetric arbitrary spin
bosonic conformal fields propagating in flat space-time are studied. Depending
on the values of conformal dimension, spin, and dimension of space-time, we
classify all conformal field as long, partial-short, short, and special
conformal fields. An ordinary-derivative (second-derivative) Lagrangian
formulation for such conformal fields is obtained. The ordinary-derivative
Lagrangian formulation is realized by using double-traceless gauge fields,
Stueckelberg fields, and auxiliary fields. Gauge-fixed Lagrangian invariant
under global BRST transformations is obtained. The gauge-fixed BRST Lagrangian
is used for the computation of partition functions for all conformal fields.
Using the result for the partition functions, numbers of propagating D.o.F for
the conformal fields are also found.


title: Neutrino-nucleon cross sections at energies of Megaton-scale detectors

abstract:
  An updated set of (anti)neutrino-nucleon charged and neutral current cross
sections at $3~{\rm GeV} \lesssim E_\nu \lesssim 100~{\rm GeV}$ is presented.
These cross sections are of particular interest for the detector optimization
and data processing and interpretation in the future Megaton-scale experiments
like PINGU, ORCA, and Hyper-Kamiokande. Finite masses of charged leptons and
target mass corrections in exclusive and deep inelastic $(\bar\nu)\nu N$
interactions are taken into account. A new set of QCD NNLO parton density
functions, the ABMP15, is used for calculation of the DIS cross sections. The
sensitivity of the cross sections to phenomenological parameters and to
extrapolations of the nucleon structure functions to small $x$ and $Q^2$ is
studied. An agreement within the uncertainties of our calculations with
experimental data is demonstrated.


title: Impact of water on the charge transport of a glass-forming ionic liquid

abstract:
  Using dielectric spectroscopy and differential scanning calorimetry, we have
performed a detailed investigation of the influence of water uptake on the
translational and reorientational glassy dynamics in the typical ionic liquid
1-Butyl-3-methyl-imidazolium chloride. From a careful analysis of the measured
dielectric permittivity and conductivity spectra, we find a significant
acceleration of cation reorientation and a marked increase of the ionic
conductivity for higher water contents. The latter effect mainly arises due to
a strong impact of water content on the glass temperature, which for the
well-dried material is found to be larger than any values reported in
literature for this system. The fragility, characterizing the non-Arrhenius
glassy dynamics of the ionic subsystem, also changes with varying water
content. Decoupling of the ionic motion from the structural dynamics has to be
considered to explain the results.


title: On Fully Dynamic Graph Sparsifiers

abstract:
  We initiate the study of dynamic algorithms for graph sparsification problems
and obtain fully dynamic algorithms, allowing both edge insertions and edge
deletions, that take polylogarithmic time after each update in the graph. Our
three main results are as follows. First, we give a fully dynamic algorithm for
maintaining a $ (1 \pm \epsilon) $-spectral sparsifier with amortized update
time $poly(\log{n}, \epsilon^{-1})$. Second, we give a fully dynamic algorithm
for maintaining a $ (1 \pm \epsilon) $-cut sparsifier with \emph{worst-case}
update time $poly(\log{n}, \epsilon^{-1})$. Both sparsifiers have size $ n
\cdot poly(\log{n}, \epsilon^{-1})$. Third, we apply our dynamic sparsifier
algorithm to obtain a fully dynamic algorithm for maintaining a $(1 +
\epsilon)$-approximation to the value of the maximum flow in an unweighted,
undirected, bipartite graph with amortized update time $poly(\log{n},
\epsilon^{-1})$.


title:
High-resolution abundance analysis of red giants in the metal-poor bulge
  globular cluster HP~1

abstract:
  The globular cluster HP~1 is projected at only 3.33 degrees from the Galactic
center. Together with its distance, this makes it one of the most central
globular clusters in the Milky Way. It has a blue horizontal branch (BHB) and a
metallicity of [Fe/H]~-1.0. This means that it probably is one of the oldest
objects in the Galaxy. Abundance ratios can reveal the nucleosynthesis pattern
of the first stars as well as the early chemical enrichment and early formation
of stellar populations. High-resolution spectra obtained for six stars were
analyzed to derive the abundances of the light elements C, N, O, Na, and Al,
the alpha-elements Mg, Si, Ca, and Ti, and the heavy elements Sr, Y , Zr, Ba,
La, and Eu.} High-resolution spectra of six red giants that are confirmed
members of the bulge globular cluster HP~1 were obtained with the 8m VLT
UT2-Kueyen telescope with the UVES spectrograph in FLAMES-UVES configuration.
The spectroscopic parameter derivation was based on the excitation and
ionization equilibrium of FeI and FeII. We confirm a mean metallicity of [Fe/H]
= -1.06~0.10, by adding the two stars that were previously analyzed in HP~1.
The alpha-elements O and Mg are enhanced by about +0.3<[O,Mg/Fe]<+0.5 dex, Si
is moderately enhanced with +0.15<[Si/Fe]<+0.35dex, while Ca and Ti show lower
values of -0.04<[Ca,Ti/Fe]<+0.28dex. The r-element Eu is also enhanced with
[Eu/Fe]~+0.4, which together with O and Mg is indicative of early enrichment by
type II supernovae. Na and Al are low, but it is unclear if Na-O are
anticorrelated. The heavy elements are moderately enhanced, with
-0.20<[La/Fe]<+0.43dex and 0.0<[Ba/Fe]<+0.75~dex, which is compatible with
r-process formation. The spread in Y, Zr, Ba, and La abundances, on the other
hand, appears to be compatible with the spinstar scenario or other additional
mechanisms such as the weak r-process.


title: Dynamics of beneficial epidemics

abstract:
  Pathogens can spread epidemically through populations. Beneficial contagions,
such as viruses that enhance host survival or technological innovations that
improve quality of life, also have the potential to spread epidemically. How do
the dynamics of beneficial biological and social epidemics differ from those of
detrimental epidemics? We investigate this question using three theoretical
approaches. First, in the context of population genetics, we show that a
horizontally-transmissible element that increases fitness, such as viral DNA,
spreads superexponentially through a population, more quickly than a beneficial
mutation. Second, in the context of behavioral epidemiology, we show that
infections that cause increased connectivity lead to superexponential fixation
in the population. Third, in the context of dynamic social networks, we find
that preferences for increased global infection accelerate spread and produce
superexponential fixation, but preferences for local assortativity halt
epidemics by disconnecting the infected from the susceptible. We conclude that
the dynamics of beneficial biological and social epidemics are characterized by
the rapid spread of beneficial elements, which is facilitated in biological
systems by horizontal transmission and in social systems by active spreading
behavior of infected individuals.

categories: physics.soc-ph cs.MA cs.SI nlin.AO q-bio.PE


title:
On the Duration and Intensity of Competitions in Nonlinear P\'olya Urn
  Processes with Fitness

abstract:
  Cumulative advantage (CA) refers to the notion that accumulated resources
foster the accumulation of further resources in competitions, a phenomenon that
has been empirically observed in various contexts. The oldest and arguably
simplest mathematical model that embodies this general principle is the P\'olya
urn process, which finds applications in a myriad of problems. The original
model captures the dynamics of competitions between two equally fit agents
under linear CA effects, which can be readily generalized to incorporate
different fitnesses and nonlinear CA effects. We study two statistics of
competitions under the generalized model, namely duration (i.e., time of the
last tie) and intensity (i.e., number of ties). We give rigorous mathematical
characterizations of the tail distributions of both duration and intensity
under the various regimes for fitness and nonlinearity, which reveal very
interesting behaviors. For example, fitness superiority induces much shorter
competitions in the sublinear regime while much longer competitions in the
superlinear regime. Our findings can shed light on the application of P\'olya
urn processes in more general contexts where fitness and nonlinearity may be
present.


title: Hopf braces and Yang-Baxter operators

abstract:
  This paper introduces Hopf braces, a new algebraic structure related to the
Yang-Baxter equation which include Rump's braces and their non-commutative
generalizations as particular cases. Several results of classical braces are
still valid in our context. Furthermore, Hopf braces provide the right setting
for considering left symmetric algebras as Lie-theoretical analogs of braces.


title: WeSME: Uncovering Mutual Exclusivity of Cancer Drivers and Beyond

abstract:
  Mutual exclusivity is a widely recognized property of many cancer drivers.
Knowledge about these relationships can provide important insights into cancer
drivers, cancer-driving pathways, and cancer subtypes. It can also be used to
predict new functional interactions between cancer driving genes and uncover
novel cancer drivers. Currently, most of mutual exclusivity analyses are
preformed focusing on a limited set of genes in part due to the computational
cost required to rigorously compute p-values. To reduce the computing cost and
perform less restricted mutual exclusivity analysis, we developed an efficient
method to estimate p-values while controlling the mutation rates of individual
patients and genes similar to the permutation test. A comprehensive mutual
exclusivity analysis allowed us to uncover mutually exclusive pairs, some of
which may have relatively low mutation rates. These pairs often included likely
cancer drivers that have been missed in previous analyses. More importantly,
our results demonstrated that mutual exclusivity can also provide information
that goes beyond the interactions between cancer drivers and can, for example,
elucidate different mutagenic processes in different cancer groups. In
particular, including frequently mutated, long genes such as TTN in our
analysis allowed us to observe interesting patterns of APOBEC activity in
breast cancer and identify a set of related driver genes that are highly
predictive of patient survival. In addition, we utilized our mutual exclusivity
analysis in support of a previously proposed model where APOBEC activity is the
underlying process that causes TP53 mutations in a subset of breast cancer
cases.


title:
Hankel Matrix Nuclear Norm Regularized Tensor Completion for
  $N$-dimensional Exponential Signals

abstract:
  Signals are generally modeled as a superposition of exponential functions in
spectroscopy of chemistry, biology and medical imaging. For fast data
acquisition or other inevitable reasons, however, only a small amount of
samples may be acquired and thus how to recover the full signal becomes an
active research topic. But existing approaches can not efficiently recover
$N$-dimensional exponential signals with $N\geq 3$. In this paper, we study the
problem of recovering N-dimensional (particularly $N\geq 3$) exponential
signals from partial observations, and formulate this problem as a low-rank
tensor completion problem with exponential factor vectors. The full signal is
reconstructed by simultaneously exploiting the CANDECOMP/PARAFAC structure and
the exponential structure of the associated factor vectors. The latter is
promoted by minimizing an objective function involving the nuclear norm of
Hankel matrices. Experimental results on simulated and real magnetic resonance
spectroscopy data show that the proposed approach can successfully recover full
signals from very limited samples and is robust to the estimated tensor rank.

categories: stat.ML cs.IT cs.NA math.IT math.SP physics.med-ph


title:
Relationship between Population Dynamics and the Self-Energy in Driven
  Non-Equilibrium Systems

abstract:
  We compare the decay rates of excited populations directly calculated within
a Keldysh formalism to the equation of motion of the population itself for a
Hubbard-Holstein model in two dimensions. While it is true that these two
approaches must give the same answer, it is common to make a number of
simplifying assumptions within the differential equation for the populations
that allows one to interpret the decay in terms of hot electrons interacting
with a phonon bath. Here we show how care must be taken to ensure an accurate
treatment of the equation of motion for the populations due to the fact that
there are identities that require cancellations of terms that naively look like
they contribute to the decay rates. In particular, the average time dependence
of the Green's functions and self-energies plays a pivotal role in determining
these decay rates.

categories: cond-mat.mes-hall cond-mat.stat-mech cond-mat.str-el quant-ph


title: Naturalness of MSSM dark matter

abstract:
  There exists a vast literature examining the electroweak (EW) fine-tuning
problem in supersymmetric scenarios, but little concerned with the dark matter
(DM) one, which should be combined with the former. In this paper, we study
this problem in an, as much as possible, exhaustive and rigorous way. We have
considered the MSSM framework, assuming that the LSP is the lightest
neutralino, $\chi_1^0$, and exploring the various possibilities for the mass
and composition of $\chi_1^0$, as well as different mechanisms for annihilation
of the DM particles in the early Universe (well-tempered neutralinos, funnels
and co-annihilation scenarios). We also present a discussion about the
statistical meaning of the fine-tuning and how it should be computed for the DM
abundance, and combined with the EW fine-tuning. The results are very robust
and model-independent and favour some scenarios (like the h-funnel when
$M_{\chi_1^0}$ is not too close to $m_h/2$) with respect to others (such as the
pure wino case). These features should be taken into account when one explores
"natural SUSY" scenarios and their possible signatures at the LHC and in DM
detection experiments.


title:
Cooperative Planning of Renewable Generations for Interconnected
  Microgrids

abstract:
  We study the renewable energy generations in Hong Kong based on realistic
meteorological data, and find that different renewable sources exhibit diverse
time-varying and location-dependent profiles. To efficiently explore and
utilize the diverse renewable energy generations, we propose a theoretical
framework for the cooperative planning of renewable generations in a system of
interconnected microgrids. The cooperative framework considers the
self-interested behaviors of microgrids, and incorporates both their long-term
investment costs and short-term operational costs over the planning horizon.
Specifically, interconnected microgrids jointly decide where and how much to
deploy renewable energy generations, and how to split the associated investment
cost. We show that the cooperative framework minimizes the overall system cost.
We also design a fair cost sharing method based on Nash bargaining to
incentivize cooperative planning, such that all microgrids will benefit from
cooperative planning. Using realistic data obtained from the Hong Kong
observatory, we validate the cooperative planning framework, and demonstrate
that all microgrids benefit through the cooperation, and the overall system
cost is reduced by 35.9% compared to the noncooperative planning benchmark.


title: On Parametric Spaces of Bicentric Quadrilaterals

abstract:
  In Euclidean geometry, a bicentric quadrilateral is a convex quadrilateral
that has both a circumcircle passing through the four vertices and an incircle
having the four sides as tangents. Consider a bicentric quadrilateral with
rational sides. We discuss the problem of finding such quadrilaterals where the
ratio of the radii of the circumcircle and incircle is rational. We show that
this problem can be formulated in terms of a family of elliptic curves given by
$E_a:y^2=x^3+(a^4-4a^3-2a^2-4a+1)x^2+16a^4x$ which have, in general, \(\mathbb
Z/8\mathbb Z\), and in rare cases \(\mathbb Z/2\mathbb Z\times\mathbb
Z/8\mathbb Z\) as torsion subgroups. We show the existence of infinitely many
elliptic curves $E_a$ of rank at least two with torsion subgroup $\mathbb
Z/8\mathbb Z$, parameterized by the points of an elliptic curve of rank at
least one, and give five particular examples of rank $5$. We, also, show the
existence of a subfamily of $E_a$ whose torsion subgroup is $\mathbb Z/2\mathbb
Z\times\mathbb Z/8\mathbb Z$.


title: All trees are six-cordial

abstract:
  For any integer $k>0$, a tree $T$ is $k$-cordial if there exists a labeling
of the vertices of $T$ by $\mathbb{Z}_k$, inducing a labeling on the edges with
edge-weights found by summing the labels on vertices incident to a given edge
modulo $k$ so that each label appears on at most one more vertex than any other
and each edge-weight appears on at most one more edge than any other.
  We prove that all trees are six-cordial by an adjustment of the test proposed
by Hovey (1991) to show all trees are $k$-cordial.


title: Observing the carbon-climate system

abstract:
  Increases in atmospheric CO2 and CH4 result from a combination of forcing
from anthropogenic emissions and Earth System feedbacks that reduce or amplify
the effects of those emissions on atmospheric concentrations. Despite decades
of research carbon-climate feedbacks remain poorly quantified. The impact of
these uncertainties on future climate are of increasing concern, especially in
the wake of recent climate negotiations. Emissions, long concentrated in the
developed world, are now shifting to developing countries, where the emissions
inventories have larger uncertainties. The fraction of anthropogenic CO2
remaining in the atmosphere has remained remarkably constant over the last 50
years. Will this change in the future as the climate evolves? Concentrations of
CH4, the 2nd most important greenhouse gas, which had apparently stabilized,
have recently resumed their increase, but the exact cause for this is unknown.
While greenhouse gases affect the global atmosphere, their sources and sinks
are remarkably heterogeneous in time and space, and traditional in situ
observing systems do not provide the coverage and resolution to attribute the
changes to these greenhouse gases to specific sources or sinks. In the past few
years, space-based technologies have shown promise for monitoring carbon stocks
and fluxes. Advanced versions of these capabilities could transform our
understanding and provide the data needed to quantify carbon-climate feedbacks.
A new observing system that allows resolving global high resolution fluxes will
capture variations on time and space scales that allow the attribution of these
fluxes to underlying mechanisms.


title: The topological sliceness of 3-strand pretzel knots

abstract:
  We give a complete characterization of the topological slice status of odd
3-strand pretzel knots, proving that an odd 3-strand pretzel knot is
topologically slice if and only if either it is ribbon or has trivial Alexander
polynomial. (By work of [FS85], a nontrivial odd 3-strand pretzel knot $K$
cannot both be ribbon and have $\Delta_K(t)=1$.) We also show that
topologically slice even 3-strand pretzel knots (except perhaps for members of
Lecuona's exceptional family of [Lec13]) must be ribbon. These results follow
from computations of the Casson-Gordon 3-manifold signature invariants
associated to the double branched covers of these knots.


title: The Search for Directed Intelligence

abstract:
  We propose a search for sources of directed energy systems such as those now
becoming technologically feasible on Earth. Recent advances in our own
abilities allow us to foresee our own capability that will radically change our
ability to broadcast our presence. We show that systems of this type have the
ability to be detected at vast distances and indeed can be detected across the
entire horizon. This profoundly changes the possibilities for searches for
extra-terrestrial technology advanced civilizations. We show that even modest
searches can be extremely effective at detecting or limiting many civilization
classes. We propose a search strategy that will observe more than 10 12 stellar
and planetary systems with possible extensions to more than 10 20 systems
allowing us to test the hypothesis that other similarly or more advanced
civilization with this same capability, and are broadcasting, exist.


title: Dictator Functions Maximize Mutual Information

abstract:
  Let $(\mathbf X, \mathbf Y)$ denote $n$ independent, identically distributed
copies of two arbitrarily correlated Rademacher random variables $(X, Y)$. We
prove that the inequality $I(f(\mathbf X); g(\mathbf Y)) \le I(X; Y)$ holds for
any two Boolean functions: $f,g \colon \{-1,1\}^n \to \{-1,1\}$ ($I(\cdot;
\cdot)$ denotes mutual information). We further show that equality in general
is achieved only by the dictator functions $f(\mathbf x)=\pm g(\mathbf x)=\pm
x_i$, $i \in \{1,2,\dots,n\}$.


title: Time-dependent Aharonov-Bohm effect on the noncommutative space

abstract:
  We study the time-dependent Aharonov-Bohm effect on the noncommutative space.
Because there is no net Aharonov-Bohm phase shift in the time-dependent case on
the commutative space, therefore, a tiny deviation from zero indicates new
physics. Based on the Seiberg-Witten map we obtain the gauge invariant and
Lorentz covariant Aharonov-Bohm phase shift in general case on noncommutative
space. We find there are two kinds of contribution: momentum-dependent and
momentum-independent corrections. For the momentum-dependent correction, there
is a cancellation between the magnetic and electric phase shifts, just like the
case on the commutative space. However, there is a non-trivial contribution in
the momentum-independent correction. This is true for both the time-independent
and time-dependent Aharonov-Bohm effects on the noncommutative space. However,
for the time-dependent Aharonov-Bohm effect, there is no overwhelming
background which exists in the time-independent Aharonov-Bohm effect on both
commutative and noncommutative space. Therefore, the time-dependent
Aharonov-Bohm can be sensitive to the spatial noncommutativity. \draftnote{The
net correction is proportional to the product of the magnetic fluxes through
the fundamental area represented by the noncommutative parameter $\theta$, and
through the surface enclosed by the trajectory of charged particle.} More
interestingly, there is an anti-collinear relation between the logarithms of
the magnetic field $B$ and the averaged flux $\Phi/N$ (N is the number of
fringes shifted). This nontrivial relation can also provide a way to test the
spatial noncommutativity. For $B\Phi/N\sim 1$, our estimation on the
experimental sensitivity shows that it can reach the $\rm 10GeV$ scale. This
sensitivity can be enhanced by using stronger magnetic field strength, larger
magnetic flux, as well as higher experimental precision on the phase shift.


title:
Convergence analysis of projected fixed-point iteration on a low-rank
  matrix manifold

abstract:
  In this paper we analyse convergence of projected fixed-point iteration on a
Riemannian manifold of matrices with fixed rank. As a retraction method we use
`projector splitting scheme'. We prove that the projector splitting scheme
converges at least with the same rate as standard fixed-point iteration without
rank constraints. We also provide counter-example to the case when conditions
of the theorem do not hold. Finally we support our theoretical results with
numerical experiments.


title:
On a collocation method for the time-fractional convection-diffusion
  equation with variable coefficients

abstract:
  In this work, a new collocation approach using a combination of a wavelet
operational matrix method and the exponential spline interpolation is proposed
to solve the time-fractional convection-diffusion equation with variable
coefficients. The operational matrix of fractional order integration is first
derived based on sine-cosine wavelet functions, which helps to convert the
underlying equation into a linear algebraic system. Then, an exponential
B-spline method is introduced in spatial direction. On selecting a set of
proper collocation points, the method in presence is evaluated on several test
problems and the numerical results finally illustrate its validity and
applicability.


title: Parallel Delta-Stepping Algorithm for Shared Memory Architectures

abstract:
  We present a shared memory implementation of a parallel algorithm, called
delta-stepping, for solving the single source shortest path problem for
directed and undirected graphs. In order to reduce synchronization costs we
make some deviations from the algorithm and discuss the consequences. We study
the behaviour of our implementation on small-world and scale-free graphs, and
graphs arising from game maps. We collect performance data on multi-core CPUs
and Intel Xeon Phi. When run in sequential mode, our implementation outperforms
the implementation of Dijkstra's algorithm from Boost Graph Library on graphs
with a small diameter. Both on the CPU and the co-processor we achieve an
overall performance of at least 50% parallel efficiency.


title:
Distributed Resource Management in Systems of Systems: An Architecture
  Perspective

abstract:
  This paper introduces a framework for studying the interactions of autonomous
system components and the design of the connectivity structure in Systems of
Systems (SoSs). This framework, which uses complex network models, is also used
to study the connectivity structure's impact on resource management. We discuss
resource sharing as a mechanism that adds a level of flexibility to distributed
systems and describe the connectivity structures that enhance components'
access to the resources available within the system. The framework introduced
in this paper explicitly incorporates costs of connection and the benefits that
are received by direct and indirect access to resources and provides measures
of the optimality of connectivity structures. We discuss central and a
distributed schemes that, respectively, represent systems in which a central
planner determines the connectivity structure and systems in which distributed
components are allowed to add and sever connections to improve their own
resource access. Furthermore, we identify optimal connectivity structures for
systems with various heterogeneity conditions.


title: Trajectory Aligned Features For First Person Action Recognition

abstract:
  Egocentric videos are characterised by their ability to have the first person
view. With the popularity of Google Glass and GoPro, use of egocentric videos
is on the rise. Recognizing action of the wearer from egocentric videos is an
important problem. Unstructured movement of the camera due to natural head
motion of the wearer causes sharp changes in the visual field of the egocentric
camera causing many standard third person action recognition techniques to
perform poorly on such videos. Objects present in the scene and hand gestures
of the wearer are the most important cues for first person action recognition
but are difficult to segment and recognize in an egocentric video. We propose a
novel representation of the first person actions derived from feature
trajectories. The features are simple to compute using standard point tracking
and does not assume segmentation of hand/objects or recognizing object or hand
pose unlike in many previous approaches. We train a bag of words classifier
with the proposed features and report a performance improvement of more than
11% on publicly available datasets. Although not designed for the particular
case, we show that our technique can also recognize wearer's actions when hands
or objects are not visible.


title: Discovery of Weyl semimetal state violating Lorentz invariance in MoTe2

abstract:
  A new type of Weyl semimetal state, in which the energy values of Weyl nodes
are not the local extrema, has been theoretically proposed recently, namely
type II Weyl semimetal. Distinguished from type I semimetal (e.g. TaAs), the
Fermi surfaces in a type II Weyl semimetal consist of a pair of electron and
hole pockets touching at the Weyl node. In addition, Weyl fermions in type II
Weyl semimetals violate Lorentz invariance. Due to these qualitative
differences distinct spectroscopy and magnetotransport properties are expected
in type II Weyl semimetals. Here, we present the direct observation of the
Fermi arc states in MoTe2 by using angle resolved photoemission spectroscopy.
Two arc states are identified for each pair of Weyl nodes whoes surface
projections of them possess single topological charge, which is a unique
property for type II Weyl semimetals. The experimentally determined Fermi arcs
are consistent with our first principle calculations. Our results unambiguously
establish that MoTe2 is a type II Weyl semimetal, which serves as a great test
bed to investigate the phenomena of new type of Weyl fermions with Lorentz
invariance violated.


title:
String completion of an $\mathrm{SU(3)_c \otimes SU(3)_L \otimes
  U(1)_X}$ electroweak model

abstract:
  The extended electroweak $\mathrm{SU(3)_c \otimes SU(3)_L \otimes U(1)_X}$
symmetry framework "explaining" the number of fermion families is revisited.
While $331$-based schemes can not easily be unified within the conventional
field theory sense, we show how to do it within an approach based on D-branes
and (un)oriented open strings, on Calabi-Yau singularities. We show how the
theory can be UV-completed in a quiver setup, free of gauge and string
anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos
are Dirac-type, and their lightness results from a novel TeV scale seesaw
mechanism. Dynamical violation of baryon number by exotic instantons could
induce neutron-antineutron oscillations, with proton decay and other dangerous
R-parity violating processes strictly forbidden.


title:
Law of large numbers for the largest component in a hyperbolic model of
  complex networks

abstract:
  We consider the component structure of a recent model of random graphs on the
hyperbolic plane that was introduced by Krioukov et al. The model exhibits a
power law degree sequence, small distances and clustering, features that are
associated with the so-called complex networks. The model is controlled by two
parameters $\alpha$ and $\nu$ where, roughly speaking, $\alpha$ controls the
exponent of the power law and $\nu$ controls the average degree. Refining
earlier results, we are able to show a law of large numbers for the largest
component. That is, we show that the fraction of points in the largest
component tends in probability to a constant $c$ that depends only on
$\alpha,\nu$, while all other components are sublinear. We also study how $c$
depends on $\alpha, \nu$. To deduce our results, we introduce a local
approximation of the random graph by a continuum percolation model on
$\mathbb{R}^2$ that may be of independent interest.


title:
Data processing for the sandwiched R\'enyi divergence: a condition for
  equality

abstract:
  The $\alpha$-sandwiched R\'enyi divergence satisfies the data processing
inequality, i.e. monotonicity under quantum operations, for $\alpha\geq 1/2$.
In this article, we derive a necessary and sufficient algebraic condition for
equality in the data processing inequality for the $\alpha$-sandwiched R\'enyi
divergence for all $\alpha\geq 1/2$. For the range $\alpha\in [1/2,1)$, our
result provides the only condition for equality obtained thus far. To prove our
result, we first consider the special case of partial trace, and derive a
condition for equality based on the original proof of the data processing
inequality by Frank and Lieb [J. Math. Phys. 54.12 (2013), p. 122201] using a
strict convexity/concavity argument. We then generalize to arbitrary quantum
operations via the Stinespring Representation Theorem. As applications of our
condition for equality in the data processing inequality, we deduce conditions
for equality in various entropic inequalities. We formulate a R\'enyi version
of the Araki-Lieb inequality and analyze the case of equality, generalizing a
result by Carlen and Lieb [Lett. Math. Phys. 101.1 (2012), pp. 1-11] about
equality in the original Araki-Lieb inequality. Furthermore, we prove a general
lower bound on a R\'enyi version of the entanglement of formation, and observe
that it is attained by states saturating the R\'enyi version of the Araki-Lieb
inequality. Finally, we prove that the known upper bound on the entanglement
fidelity in terms of the usual fidelity is saturated only by pure states.


title: BTZ Black Holes and Flat Space Cosmologies in Higher Derivative Theories

abstract:
  We consider BTZ black holes and flat space cosmologies in generic higher
derivative gravity theories in 2+1 dimensions. Our goal is to prove the match
between the bulk Iyer-Wald entropy and the field theory entropy for various
symmetry algebras (CFT$_2$, Warped CFT$_2$, BMS$_3$). We also discuss phase
transitions in higher curvature theories, and argue that, in the flat case,
there is strictly speaking no phase transition in the grand canonical ensemble.


title: Boson stars in biscalar extensions of Horndeski gravity

abstract:
  This paper is concerned with the construction and analysis of boson stars in
the context of nonminimal derivative coupling theories. In particular we embed
our model in the biscalar extension of Horndeski gravity, considering a scalar
field theory displaying a nonminimally coupled kinetic term given by the
Einstein tensor. We focus on the case where the potential is given by a mass
term only, and when a six order self-interaction is included. In the latter
case we consider specific couplings in the self-interacting terms in such a way
that our self-interaction is given by a positive definite potential presenting
two degenerate local vacua. We show how solutions can be obtained and we
compare its principal properties with standard configurations constructed with
the usual minimally coupled kinetic term.


title:
Modeling Concurrency and Reconfiguration in Vehicular Systems: A
  $\pi$-calculus Approach

abstract:
  As autonomous or semi-autonomous vehicles are deployed on the roads, they
will have to eventually start communicating with each other in order to achieve
increased efficiency and safety. Current approaches in the control of
collaborative vehicles primarily consider homogeneous simplified vehicle
dynamics and usually ignore any communication issues. This raises an important
question of how systems without the aforementioned limiting assumptions can be
modeled, analyzed and certified for safe operation by both industry and
governmental agencies. In this work, we propose a modeling framework where
communication and system reconfiguration is modeled through $\pi$-calculus
expressions while the closed-loop control systems are modeled through hybrid
automata. We demonstrate how the framework can be utilized for modeling and
simulation of platooning behaviors of heterogeneous vehicles.


title:
Multilevel Weighted Support Vector Machine for Classification on
  Healthcare Data with Missing Values

abstract:
  This work is motivated by the needs of predictive analytics on healthcare
data as represented by Electronic Medical Records. Such data is invariably
problematic: noisy, with missing entries, with imbalance in classes of
interests, leading to serious bias in predictive modeling. Since standard data
mining methods often produce poor performance measures, we argue for
development of specialized techniques of data-preprocessing and classification.
In this paper, we propose a new method to simultaneously classify large
datasets and reduce the effects of missing values. It is based on a multilevel
framework of the cost-sensitive SVM and the expected maximization imputation
method for missing values, which relies on iterated regression analyses. We
compare classification results of multilevel SVM-based algorithms on public
benchmark datasets with imbalanced classes and missing values as well as real
data in health applications, and show that our multilevel SVM-based method
produces fast, and more accurate and robust classification results.


title:
Theoretical prediction of magnetic and noncentrosymmetric Weyl fermion
  semimetal states in the R-Al-X family of compounds (R=rare earth,
  Al=aluminium, X=Si, Ge)

abstract:
  Weyl semimetals are novel topological conductors that host Weyl fermions as
emergent quasiparticles. While the Weyl fermions in high-energy physics are
strictly defined as the massless solution of the Dirac equation and uniquely
fixed by Lorentz symmetry, there is no such constraint for a topological metal
in general. Specifically, the Weyl quasiparticles can arise by breaking either
the space-inversion ($\mathcal{I}$) or time-reversal ($\mathcal{T}$) symmetry.
They can either respect Lorentz symmetry (type-I) or strongly violate it
(type-II). To date, different types of Weyl fermions have been predicted to
occur only in different classes of materials. In this paper, we present a
significant materials breakthrough by identifying a large class of Weyl
materials in the RAlX (R=Rare earth, Al, X=Ge, Si) family that can realize all
different types of emergent Weyl fermions ($\mathcal{I}$-breaking,
$\mathcal{T}$-breaking, type-I or type-II), depending on a suitable choice of
the rare earth elements. Specifically, RAlX can be ferromagnetic, nonmagnetic
or antiferromagnetic and the electronic band topology and topological nature of
the Weyl fermions can be tuned. The unparalleled tunability and the large
number of compounds make the RAlX family of compounds a unique Weyl semimetal
class for exploring the wide-ranging topological phenomena associated with
different types of emergent Weyl fermions in transport, spectroscopic and
device-based experiments.


title:
Resolving Language and Vision Ambiguities Together: Joint Segmentation &
  Prepositional Attachment Resolution in Captioned Scenes

abstract:
  We present an approach to simultaneously perform semantic segmentation and
prepositional phrase attachment resolution for captioned images. Some
ambiguities in language cannot be resolved without simultaneously reasoning
about an associated image. If we consider the sentence "I shot an elephant in
my pajamas", looking at language alone (and not using common sense), it is
unclear if it is the person or the elephant wearing the pajamas or both. Our
approach produces a diverse set of plausible hypotheses for both semantic
segmentation and prepositional phrase attachment resolution that are then
jointly reranked to select the most consistent pair. We show that our semantic
segmentation and prepositional phrase attachment resolution modules have
complementary strengths, and that joint reasoning produces more accurate
results than any module operating in isolation. Multiple hypotheses are also
shown to be crucial to improved multiple-module reasoning. Our vision and
language approach significantly outperforms the Stanford Parser (De Marneffe et
al., 2006) by 17.91% (28.69% relative) and 12.83% (25.28% relative) in two
different experiments. We also make small improvements over DeepLab-CRF (Chen
et al., 2015).


title: On Stochastic Belief Revision and Update and their Combination

abstract:
  I propose a framework for an agent to change its probabilistic beliefs when a
new piece of propositional information $\alpha$ is observed. Traditionally,
belief change occurs by either a revision process or by an update process,
depending on whether the agent is informed with $\alpha$ in a static world or,
respectively, whether $\alpha$ is a 'signal' from the environment due to an
event occurring. Boutilier suggested a unified model of qualitative belief
change, which "combines aspects of revision and update, providing a more
realistic characterization of belief change." In this paper, I propose a
unified model of quantitative belief change, where an agent's beliefs are
represented as a probability distribution over possible worlds. As does
Boutilier, I take a dynamical systems perspective. The proposed approach is
evaluated against several rationality postulated, and some properties of the
approach are worked out.