title:
The CO-H2 van der Waals complex and complex organic molecules in cold
  molecular clouds: a TMC-1C survey

abstract:
  Almost 200 different species have been detected in the interstellar medium
(ISM) during the last decades, revealing not only simple species but complex
molecules with more than 6 atoms. Other exotic compounds, like the weakly-bound
dimer (H2)2, have also been detected in astronomical sources like Jupiter. We
aim at detecting for the first time the CO-H2 van der Waals complex in the ISM,
which if detected can be a sensitive indicator for low temperatures. We use the
IRAM30m telescope, located in Pico Veleta (Spain), to search for the CO-H2
complex in a cold, dense core in TMC-1C (with a temperature of 10 K). All the
brightest CO-H2 transitions in the 3 mm (80-110 GHz) band have been observed
with a spectral resolution of 0.5-0.7 km/s, reaching a rms noise level of 2 mK.
The simultaneous observation of a broad frequency band, 16 GHz, has allowed us
to conduct a serendipitous spectral line survey. No lines belonging to the
CO-H2 complex have been detected. We have set up a new, more stringent upper
limit for its abundance to be [CO-H2]/[CO] = 5x10^{-6}, while we expect the
abundance of the complex to be in the range 10^{-8}-10^{-3}. The spectral line
survey has allowed us to detect 75 lines associated with 41 different species
(including isotopologues). We detect a number of complex organic species, e.g.
methyl cyanide (CH3CN), methanol (CH3OH), propyne (CH3CCH) and ketene (CH2CO),
associated with cold gas (excitation temperatures about 7 K), confirming the
presence of these complex species not only in warm objects but also in cold
regimes.


title:
Analytic solutions in the acoustic black hole analogue of the conical
  Kerr metric

abstract:
  We study the sound perturbation of a rotating acoustic black hole in the
presence of a disclination. The radial part of the massless Klein-Gordon
equation is written into a Heun form, and its analytical solution is obtained.
These solutions have an explicit dependence on the parameter of the
disclination. We obtain the exact Hawking-Unruh radiation spectrum.


title: Excited Weak Bosons and Dark Matter

abstract:
  The weak bosons are bound states of new constituents. The p-wave excitations
are studied. The state with the lowest mass is identified with the boson, which
has been discovered at the LHC. Specific properties of the excited bosons are
discussed, in particular their decays into weak bosons and photons. The stable
fermion, consisting of three haplons, provides the dark matter in our universe.


title:
Remarks on $L^p$-limiting absorption principle of Schr\"odinger
  operators and applications to spectral multiplier theorems

abstract:
  This paper comprises two parts. We first investigate a $L^p$ type of limiting
absorption principle for Schr\"odinger operators $H=-\Delta+V$, i.e., In
$\mathbb{R}^n$ ($n\ge 3$) we prove the $\epsilon-$uniform
$L^{\frac{2(n+1)}{n+3}}$-$L^{\frac{2(n+1)}{n-1}}$ estimates of the resolvent
$(H-\lambda\pm i\epsilon)^{-1}$ for all $\lambda>0$ when the potential $V$
belongs to some integrable spaces and a spectral condition of $H$ at zero is
assumed. As an application, we establish a sharp spectral multiplier theorem
and $L^p$ bound of Bochner-Riesz means associated with Schr\"odinger operators
$H$. Next, we consider the fractional Schr\"odinger operator
$H=(-\Delta)^{\alpha}+V$ ($0<2\alpha<n$) and prove a uniform
Hardy-Littlewood-Sobolev inequality for $(-\Delta)^{\alpha}$, which generalizes
the corresponding result of Kenig-Ruiz-Sogge \cite{KRS}.


title: Smoothness of Minkowski sum and generic rotations

abstract:
  Can the Minkowski sum of two compact convex bodies be made smoother by
rotating one of them? We construct two infinitely differentiable strictly
convex plane bodies such that after any generic rotation (in the Baire category
sense) of one of the summands the Minkowski sum is not five times
differentiable. On the other hand, if for one of the bodies the zero set of the
Gaussian curvature has countable spherical image, we show that any generic
rotation makes their Minkowski sum as smooth as the summands. We also improve
and clarify some previous results on smoothness of the Minkowski sum.


title: Hybrid Recommender System Based on Personal Behavior Mining

abstract:
  Recommender systems are mostly well known for their applications in
e-commerce sites and are mostly static models. Classical personalized
recommender algorithm includes item-based collaborative filtering method
applied in Amazon, matrix factorization based collaborative filtering algorithm
from Netflix, etc. In this article, we hope to combine traditional model with
behavior pattern extraction method. We use desensitized mobile transaction
record provided by T-mall, Alibaba to build a hybrid dynamic recommender
system. The sequential pattern mining aims to find frequent sequential pattern
in sequence database and is applied in this hybrid model to predict customers'
payment behavior thus contributing to the accuracy of the model.


title:
Exposing boundary points of strongly pseudoconvex subvarieties in
  complex spaces

abstract:
  We prove that all locally exposable points in a Stein compact in a complex
space can be exposed along a given curve to a given real hypersurface.
Moreover, the exposing map for a boundary point can be sufficiently close to
the identity map outside any fixed neighborhood of the point. We also prove a
parametric version of this result for bounded strongly pseudoconvex domains in
$\mathbb C^n$. For a bounded strongly pseudoconvex domain in $\mathbb C^n$ and
a given boundary point of it, we prove that there is a global coordinate change
on the closure of the domain which is arbitrarily close to the identity map
with respect to the $C^1$-norm and maps the boundary point to a strongly convex
boundary point.


title:
Marichev-Saigo-Maeda fractional operator representations of generalized
  Struve function

abstract:
  The aim of this paper is to apply generalized operators of fractional
integration and differentiation involving Appells function due to
Marichev-Saigo-Maeda, to the generalized Struve function. The results are
expressed in terms of generalized Wright function. The results obtained here
are general in nature and can easily obtain various known results.


title: Memory Unscented Particle Filter for 6-DOF Tactile Localization

abstract:
  This paper addresses 6-DOF (degree-of-freedom) tactile localization, i.e. the
pose estimation of tridimensional objects given tactile measurements. This
estimation problem is fundamental for the operation of autonomous robots that
are often required to manipulate and grasp objects whose pose is a-priori
unknown. The nature of tactile measurements, the strict time requirements for
real-time operation and the multimodality of the involved probability
distributions pose remarkable challenges and call for advanced nonlinear
filtering techniques. Following a Bayesian approach, this paper proposes a
novel and effective algorithm, named Memory Unscented Particle Filter (MUPF),
which solves the 6-DOF localization problem recursively in real-time by only
exploiting contact point measurements. MUPF combines a modified particle filter
that incorporates a sliding memory of past measurements to better handle
multimodal distributions, along with the unscented Kalman filter that moves the
particles towards regions of the search space that are more likely with the
measurements. The performance of the proposed MUPF algorithm has been assessed
both in simulation and on a real robotic system equipped with tactile sensors
(i.e., the iCub humanoid robot). The experiments show that the algorithm
provides accurate and reliable localization even with a low number of particles
and, hence, is compatible with real-time requirements.


title:
Improving Population Monte Carlo: Alternative Weighting and Resampling
  Schemes

abstract:
  Population Monte Carlo (PMC) sampling methods are powerful tools for
approximating distributions of static unknowns given a set of observations.
These methods are iterative in nature: at each step they generate samples from
a proposal distribution and assign them weights according to the importance
sampling principle. Critical issues in applying PMC methods are the choice of
the generating functions for the samples and the avoidance of the sample
degeneracy. In this paper, we propose three new schemes that considerably
improve the performance of the original PMC formulation by allowing for better
exploration of the space of unknowns and by selecting more adequately the
surviving samples. A theoretical analysis is performed, proving the superiority
of the novel schemes in terms of variance of the associated estimators and
preservation of the sample diversity. Furthermore, we show that they outperform
other state of the art algorithms (both in terms of mean square error and
robustness w.r.t. initialization) through extensive numerical simulations.


title: Mode stability on the real axis

abstract:
  A generalization of the mode stability result of Whiting (1989) for the
Teukolsky equation is proved for the case of real frequencies. The main result
of the paper states that a separated solution of the Teukolsky equation
governing massless test fields on the Kerr spacetime, which is purely outgoing
at infinity, and purely ingoing at the horizon, must vanish. This has the
consequence, that for real frequencies, there are linearly independent
fundamental solutions of the radial Teukolsky equation which are purely ingoing
at the horizon, and purely outgoing at infinity, respectively. This fact yields
a representation formula for solutions of the inhomogenous Teukolsky equation.


title:
Distributed Hybrid Power State Estimation under PMU Sampling Phase
  Errors

abstract:
  Phasor measurement units (PMUs) have the advantage of providing direct
measurements of power states. However, as the number of PMUs in a power system
is limited, the traditional supervisory control and data acquisition (SCADA)
system cannot be replaced by the PMU-based system overnight. Therefore, hybrid
power state estimation taking advantage of both systems is important. As
experiments show that sampling phase errors among PMUs are inevitable in
practical deployment, this paper proposes a distributed power state estimation
algorithm under PMU phase errors. The proposed distributed algorithm only
involves local computations and limited information exchange between
neighboring areas, thus alleviating the heavy communication burden compared to
the centralized approach. Simulation results show that the performance of the
proposed algorithm is very close to that of centralized optimal hybrid state
estimates without sampling phase error.


title:
Subarcsecond international LOFAR radio images of Arp 220 at 150 MHz: A
  kpc-scale star forming disk surrounding nuclei with shocked outflows

abstract:
  We analyse new observations with the International Low Frequency Array
(LOFAR) telescope, and archival data from the Multi-Element Radio Linked
Interferometer Network (MERLIN) and the Karl G. Jansky Very Large Array (VLA).
We model the spatially resolved radio spectrum of Arp 220 from 150 MHz to 33
GHz. We present an image of Arp 220 at 150 MHz with resolution
$0.65''\times0.35''$, sensitivity 0.15 mJy beam$^{-1}$, and integrated flux
density $394\pm59$ mJy. More than 80% of the detected flux comes from extended
($6''\approx$2.2 kpc) steep spectrum ($\alpha=-0.7$) emission, likely from star
formation in the molecular disk surrounding the two nuclei. We find elongated
features extending $0.3''$ (110 pc) and $0.9''$ (330 pc) from the eastern and
western nucleus respectively, which we interpret as evidence for outflows. The
extent of radio emission requires acceleration of cosmic rays far outside the
nuclei. We find that a simple three component model can explain most of the
observed radio spectrum of the galaxy. When accounting for absorption at 1.4
GHz, Arp 220 follows the FIR/radio correlation with $q=2.36$, and we estimate a
star formation rate of 220 M$_\odot\text{yr}^{-1}$. We derive thermal fractions
at 1 GHz of less than 1% for the nuclei, which indicates that a major part of
the UV-photons are absorbed by dust. International LOFAR observations shows
great promise to detect steep spectrum outflows and probe regions of thermal
absorption. However, in LIRGs the emission detected at 150 MHz does not
necessarily come from the main regions of star formation. This implies that
high spatial resolution is crucial for accurate estimates of star formation
rates for such galaxies at 150 MHz.


title: Subspaces of $\displaystyle H^{p}$ linearly homeomorphic to $l^{p}.$

abstract:
  We present two fast constructions of weak*-copies of $\ell ^\infty$ in
$H^{\infty}$ and show that such copies are necessarily weak*-complemented.
Moreover, via a Paley-Wiener type of stability theorem for bases, a connection
can be made in some cases between the two types of construction, via
interpolating sequences (in fact these are at the basis of the second
construction). Our approach has natural generalizations where H $\infty$ is
replaced by an arbitrary dual space and $\ell ^{\infty }$ by $\ell^{p}$ (1
$\le$ p $\le$ $\infty$) relying on the notions of generalized interpolating
sequence and bounded linear extension. An old (very simple but unpublished so
far) construction of bases which are Besselian but not Hilbertian finds a
natural place in this development.


title: How to Allocate Resources For Features Acquisition?

abstract:
  We study classification problems where features are corrupted by noise and
where the magnitude of the noise in each feature is influenced by the resources
allocated to its acquisition. This is the case, for example, when multiple
sensors share a common resource (power, bandwidth, attention, etc.). We develop
a method for computing the optimal resource allocation for a variety of
scenarios and derive theoretical bounds concerning the benefit that may arise
by non-uniform allocation. We further demonstrate the effectiveness of the
developed method in simulations.


title:
Crossover from collisionless to collisional spin dynamics of polarized
  fermions

abstract:
  We study the transverse spin dynamics of trapped polarized Fermi gases in the
high temperature limit. In the non-interacting collisionless regime, a magnetic
field gradient induces collective spin wave oscillations. In the strongly
interacting collisional regime, the dynamics are governed by spin diffusion.
These two limits have been extensively studied both experimentally and
theoretically, but the crossover between them has received less attention. In
this paper, we use a quantum Boltzmann equation to study transverse spin
dynamics and show how the excitations evolve from dispersive to diffusive in
the high temperature limit. We provide analytical solutions in the two limiting
regimes, which agree well with our numerical results.


title:
Magnetic phases of quasi-two-dimensional antiferromagnet on triangular
  lattice CuCrO$_2$

abstract:
  We have carried out $^{63,65}$Cu NMR spectra measurements in magnetic field
up to about 45~T on single crystal of a multiferroic triangular antiferromagnet
CuCrO$_2$. The measurements were performed for magnetic fields aligned along
the crystal $c$-axis. Field and temperature evolution of the spectral shape
demonstrates a number of phase transitions. It was found that the 3D magnetic
ordering takes place in the low field range ($H\lesssim15$~T). At higher fields
magnetic structures form within individual triangular planes whereas the spin
directions of the magnetic ions from neighboring planes are not correlated. It
is established that the 2D-3D transition is hysteretic in field and
temperature. Lineshape analysis reveals several possible magnetic structures
existing within individual planes for different phases of CuCrO$_2$. Within
certain regions on the magnetic H-T phase diagram of CuCrO$_2$ a 3D magnetic
ordering with tensor order parameter is expected.


title:
Mobile Internet of Things: Can UAVs Provide an Energy-Efficient Mobile
  Architecture?

abstract:
  In this paper, the optimal trajectory and deployment of multiple unmanned
aerial vehicles (UAVs), used as aerial base stations to collect data from
ground Internet of Things (IoT) devices, is investigated. In particular, to
enable reliable uplink communications for IoT devices with a minimum energy
consumption, a new approach for optimal mobility of the UAVs is proposed.
First, given a fixed ground IoT network, the total transmit power of the
devices is minimized by properly clustering the IoT devices with each cluster
being served by one UAV. Next, to maintain energy-efficient communications in
time-varying mobile IoT networks, the optimal trajectories of the UAVs are
determined by exploiting the framework of optimal transport theory. Simulation
results show that by using the proposed approach, the total transmit power of
IoT devices for reliable uplink communications can be reduced by 56% compared
to the fixed Voronoi deployment method. Moreover, our results yield the optimal
paths that will be used by UAVs to serve the mobile IoT devices with a minimum
energy consumption.


title:
Practical stabilization of perturbed integrator chains with unknown
  bounds

abstract:
  In this paper, we present Lyapunov-based adaptive controllers for the
practical (or real) stabilization of a perturbed chain of integrators with
bounded uncertainties. We refer to such controllers as Adaptive Higher Order
Sliding Mode (AHOSM) controllers since they are designed for nonlinear SISO
systems with bounded uncertainties such that the uncertainty bounds are
unknown. Our main result states that, given any neighborhood N of the origin,
we determine a controller insuring, for every uncertainty bounds, that every
trajectory of the corresponding closed loop system enters N and eventually
remains there. The effectiveness of these controllers is illustrated through
simulations.


title:
Relating information entropy and mass variance to measure bias and
  non-Gaussianity

abstract:
  We relate the information entropy and the mass variance of any distribution
in the regime of small fluctuations. We use a set of Monte Carlo simulations of
different homogeneous and inhomogeneous distributions to verify the relation
and also test it in a set of cosmological N-body simulations. We find that the
relation is in excellent agreement with the simulations and is independent of
number density and the nature of the distributions. We show that the relation
between information entropy and mass variance can be used to determine the
linear bias on large scales and detect the signatures of non-Gaussianity on
small scales in galaxy distributions.


title: Annotation Methodologies for Vision and Language Dataset Creation

abstract:
  Annotated datasets are commonly used in the training and evaluation of tasks
involving natural language and vision (image description generation, action
recognition and visual question answering). However, many of the existing
datasets reflect problems that emerge in the process of data selection and
annotation. Here we point out some of the difficulties and problems one
confronts when creating and validating annotated vision and language datasets.


title:
Sampling-based bottleneck pathfinding with applications to Frechet
  matching

abstract:
  We describe a general probabilistic framework to address a variety of
Frechet-distance optimization problems. Specifically, we are interested in
finding minimal bottleneck-paths in $d$-dimensional Euclidean space between
given start and goal points, namely paths that minimize the maximal value over
a continuous cost map. We present an efficient and simple sampling-based
framework for this problem, which is inspired by, and draws ideas from,
techniques for robot motion planning. We extend the framework to handle not
only standard bottleneck pathfinding, but also the more demanding case, where
the path needs to be monotone in all dimensions. Finally, we provide
experimental results of the framework on several types of problems.


title:
Large-scale shell-model calculations on the spectroscopy of $N<126$ Pb
  isotopes

abstract:
  Large-scale shell-model calculations are carried out in the model space
including neutron-hole orbitals $2p_{1/2}$, $1f_{5/2}$, $2p_{3/2}$,
$0i_{13/2}$, $1f_{7/2}$ and $0h_{9/2}$ to study the structure and
electromagnetic properties of neutron deficient Pb isotopes. An optimized
effective interaction is used. Good agreement between full shell-model
calculations and experimental data is obtained for the spherical states in
isotopes $^{194-206}$Pb. The lighter isotopes are calculated with an
importance-truncation approach constructed based on the monopole Hamiltonian.
The full shell-model results also agree well with our generalized seniority and
nucleon-pair-approximation truncation calculations. The deviations between
theory and experiment concerning the excitation energies and electromagnetic
properties of low-lying $0^+$ and $2^+$ excited states and isomeric states may
provide a constraint on our understanding of nuclear deformation and intruder
configuration in this region.


title:
Large-scale configuration interaction description of the structure of
  nuclei around $^{100}$Sn and $^{208}$Pb

abstract:
  In this contribution I would like to discuss briefly the recent developments
of the nuclear configuration interaction shell model approach. As examples, we
apply the model to calculate the structure and decay properties of low-lying
states in neutron-deficient nuclei around $^{100}$Sn and $^{208}$Pb that are of
great experimental and theoretical interests.


title: Gravitational Waves in Effective Quantum Gravity

abstract:
  In this short paper we investigate quantum gravitational effects on
Einstein's equations using effective field theory techniques. We consider the
leading order quantum gravitational correction to the wave equation. Besides
the usual massless mode, we find a pair of modes with complex masses. These
massive particles have a width and could thus lead to a damping of
gravitational waves if excited in violent astrophysical processes producing
gravitational waves such as e.g. black hole mergers. We discuss the
consequences for gravitational wave events such as GW 150914 recently observed
by the Advanced LIGO collaboration.


title: Exclusive $\rho^0$ Meson Photoproduction with a Leading Neutron at HERA

abstract:
  A first measurement is presented of exclusive photoproduction of $\rho^0$
mesons associated with leading neutrons at HERA. The data were taken with the
H1 detector in the years 2006 and 2007 at a centre-of-mass energy of 319 GeV
and correspond to an integrated luminosity of 1.16/pb. The $\rho^0$ mesons with
transverse momenta $p_T<1$ GeV are reconstructed from their decays to charged
pions, while leading neutrons carrying a large fraction of the incoming proton
momentum, $x_L>$0.35, are detected in the Forward Neutron Calorimeter having a
polar angular acceptance < 0.75 mrad. Single- and double-differential cross
sections are measured as a function of several variables. The data are
interpreted in terms of a double peripheral process, involving pion exchange at
the proton vertex followed by elastic photoproduction of a $\rho^0$ meson on
the virtual pion. In the framework of one-pion-exchange dominance the elastic
cross section of photon-pion scattering is extracted. The value of this cross
section indicates significant absorptive corrections for the exclusive reaction
$\gamma p \to \rho^0 n \pi^+$.


title: The anomalous quadrupole collectivity in Te isotopes

abstract:
  We present systematic calculations on the spectroscopy and transition
properties of even-even Te isotopes by using the large-scale configuration
interaction shell model approach with a realistic interaction. These nuclei are
of particular interest since their yrast spectra show a vibrational-like
equally-spaced pattern but the few known E2 transitions show anomalous
rotational-like behavior, which cannot be reproduced by collective models. Our
calculations reproduce well the equally-spaced spectra of those isotopes as
well as the constant behavior of the $B(E2)$ values in $^{114}$Te. The
calculated $B(E2)$ values for neutron-deficient and heavier Te isotopes show
contrasting different behaviors along the yrast line. The $B(E2)$ of light
isotopes can exhibit a nearly constant bevavior upto high spins. We show that
this is related to the enhanced neutron-proton correlation when approaching
$N=50$.


title: On finite symmetries of simply connected four-manifolds

abstract:
  For most positive integer pairs $(a,b)$, the topological space $#a{\mathbb C
\mathbb P}^2#b{\bar{\mathbb C \mathbb P^2}}$ is shown to admit infinitely many
inequivalent smooth structures which dissolve upon performing a single
connected sum with $S^2\times S^2$. This is then used to construct infinitely
many non-equivalent smooth free actions of suitable finite groups on the
connected sum $#a{\mathbb C \mathbb P}^2#b{\bar{\mathbb C \mathbb P^2}}$. We
then investigate the behavior of the sign of the Yamabe invariant for the
resulting finite covers, and observe that these constructions provide many new
counter-examples to the $4$-dimensional Rosenberg Conjecture.


title: Origin of Fe3+ in Fe-containing, Al-free Mantle Silicate Perovskite

abstract:
  We have studied the ferrous (Fe2+) and ferric (Fe3+) iron concentrations in
Al-free Fe containing Mg-silicate perovskite (Mg-Pv) at pressure (P),
temperature (T), and oxygen fugacity (fO2) conditions related to the lower
mantle using a thermodynamic model based on ab-initio calculations. We consider
the oxidation reaction and the charge disproportionation reaction, both of
which can produce Fe3+ in Mg-Pv. The model shows qualitatively good agreement
with available experimental data on Fe3+/{\Sigma}Fe ({\Sigma}Fe = total Fe in
system), spin transitions, and equations of state. We predict that under
lower-mantle conditions Fe3+/{\Sigma}Fe determined by the charge
disproportionation is estimated to be 0.01-0.07 in Al-free Mg-Pv, suggesting
that low Al Mg-Pv in the uppermost pyrolitic mantle (where majoritic garnet
contains most of the Al) and in the harzburgitic heterogeneities throughout the
lower mantle contains very little Fe3+. We find that the volume reduction by
the spin transition of the B-site Fe3+ leads to a minimum Fe3+/{\Sigma}Fe in
Mg-Pv at mid-mantle pressures. The model shows that configurational entropy is
a key driving force to create Fe3+ and therefore Fe3+ content is highly
temperature sensitive. The temperature sensitivity may lead to a maximum
Fe3+/{\Sigma}Fe in Mg-Pv in warm regions at the core-mantle boundary region,
such as Large Low Shear Velocity Provinces (LLSVPs), potentially altering the
physical (e.g., bulk modulus) and transport (e.g., thermal and electrical
conductivities) properties of the heterogeneities.


title:
Generalized Multiband Typical Medium Dynamical Cluster Approximation:
  Application to (Ga,Mn)N

abstract:
  We generalize the multiband typical medium dynamical cluster approximation
and the formalism introduced by Blackman, Esterling and Berk so that it can
deal with localization in multiband disordered systems with both diagonal and
off-diagonal disorder with complicated potentials. We also introduce a new
ansatz for the angle resolved typical density of states that greatly improves
the numerical stability of the method while preserving the independence of
scattering events at different frequencies. Starting from the first-principles
effective Hamiltonian, we apply this method to the diluted magnetic
semiconductor Ga$_{1-x}$Mn$_x$N, and find the impurity band is completely
localized for Mn concentrations $x<0.03$ while for $0.03 <x<0.10$ the impurity
band has delocalized states but the chemical potential resides at or above the
mobility edge. So, the system is always insulating within the experimental
compositional limit ($x\approx 0.10$) due to Anderson localization. However,
for $0.03 <x<0.10$ hole doping could make the system metallic allowing double
exchange mediated, or enhanced, ferromagnetism. The developed method is
expected to have a large impact on first-principles studies of Anderson
localization.


title:
Imaging the redshifted 21-cm pattern around the first sources during the
  cosmic dawn using the SKA

abstract:
  Understanding properties of the first sources in the Universe using the
redshifted \HI ~21-cm signal is one of the major aims of present and upcoming
low-frequency experiments. We investigate the possibility of imaging the
redshifted 21-cm pattern around the first sources during the cosmic dawn using
the SKA1-low. We model the \HI ~21-cm image maps, appropriate for the SKA1-low,
around the first sources consisting of stars and X-ray sources within galaxies.
In addition to the system noise, we account also for the astrophysical
foregrounds by adding them to the signal maps. We find that after subtracting
the foregrounds using a polynomial fit and suppressing the noise by smoothing
the maps over $10^{'} - 30^{'}$ angular scale, the isolated sources at $z \sim
15$ are detectable with $\sim 4 - 9 \, \sigma$ confidence level in 2000 h of
observation with the SKA1-low. Although the 21-cm profiles around the sources
get altered because of the Gaussian smoothing, the images can still be used to
extract some of the source properties. We account for overlaps in the patterns
of the individual sources by generating realistic \HI ~21-cm maps of the cosmic
dawn that are based on $N$-body simulations and a one-dimensional radiative
transfer code. We find that these sources should be detectable in the SKA1-low
images at $z = 15$ with an SNR of $\sim 14 (4)$ in 2000 (200) h of
observations. One possible observational strategy thus could be to observe
multiple fields for shorter observation times, identify fields with SNR
$\gtrsim 3$ and observe these fields for much longer duration. Such
observations are expected to be useful in constraining the parameters related
to the first sources.


title:
Interpolated wave functions for nonadiabatic simulations with the
  fixed-node quantum Monte Carlo method

abstract:
  Simulating nonadiabatic effects with many-body wave function approaches is an
open field with many challenges. Recent interest has been driven by new
algorithmic developments and improved theoretical understanding of properties
unique to electron-ion wave functions. Fixed-node diffusion Monte Caro is one
technique that has shown promising results for simulating electron-ion systems.
In particular, we focus on the CH molecule for which previous results suggested
a relatively significant contribution to the energy from nonadiabatic effects.
We propose a new wave function ansatz for diatomic systems which involves
interpolating the determinant coefficients calculated from configuration
interaction methods. We find this to be an improvement beyond previous wave
function forms that have been considered. The calculated nonadiabatic
contribution to the energy in the CH molecule is reduced compared to our
previous results, but still remains the largest among the molecules under
consideration.


title:
Infrared Observations of the Quintuplet Proper Members using
  SOFIA/FORCAST and Gemini/TReCS

abstract:
  Since their discovery, the Quintuplet proper members (QPMs) have been
somewhat mysterious in nature. Originally dubbed the "cocoon stars" due to
their cool featureless spectra, high-resolution near-infrared imaging
observations have shown that at least two of the objects exhibit "pinwheel"
nebulae consistent with binary systems with a carbon-rich Wolf-Rayet star and
O/B companion. In this paper, we present 19.7, 25.2, 31.5, and 37.1 $\mu$m
observations of the QPMs (with an angular resolution of 3.2-3.8") taken with
the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) in
conjunction with high-resolution ($\sim$0.1-0.2") images at 8.8 and 11.7 $\mu$m
from the Thermal-Region Camera Spectrograph (TReCS). DUSTY models of the
thermal dust emission of two of the four detected QPMs, Q2 and Q3, are fitted
by radial density profiles which are consistent with constant mass loss rates
($\rho_d \propto r^{-2}$). For the two remaining sources, Q1 and Q9, extended
structures ($\sim$ 1") are detected around these objects in high-resolution
imaging data. Based on the fitted dust masses, Q9 has an unusually large dust
reservoir ($\mathrm{M_d}=1.3^{+0.8}_{-0.4}\times 10^{-3} \mathrm{M_{\odot}}$)
compared to typical dusty Wolf-Rayet stars which suggests that it may have
recently undergone an episode of enhanced mass loss.


title: Revisiting the optical $PT$-symmetric dimer

abstract:
  Optics has proved a fertile ground for the experimental simulation of quantum
mechanics. Most recently, optical realizations of $\mathcal{PT}$-symmetric
quantum mechanics have been shown, both theoretically and experimentally,
opening the door to international efforts aiming at the design of practical
optical devices exploiting this symmetry. Here, we focus on the optical
$\mathcal{PT}$-symmetric dimer, a two-waveguide coupler were the materials show
symmetric effective gain and loss, and provide a review of the linear and
nonlinear optical realizations from a symmetry based point of view. We go
beyond a simple review of the literature and show that the dimer is just the
smallest of a class of planar $N$-waveguide couplers that are the optical
realization of Lorentz group in 2+1 dimensions. Furthermore, we provide a
formulation to describe light propagation through waveguide couplers described
by non-Hermitian mode coupling matrices based on a non-Hermitian generalization
of Ehrenfest theorem.


title:
Tunable spin-orbit coupled Bose-Einstein condensates in deep optical
  lattices

abstract:
  Binary mixtures of Bose-Einstein condensates trapped in deep optical lattices
and subjected to equal contributions of Rashba and Dresselhaus spin-orbit
coupling (SOC), are investigated in the presence of a periodic time modulation
of the Zeeman field. SOC tunability is explicitly demonstrated by adopting a
mean-field tight-binding model for the BEC mixture and by performing an
averaging approach in the strong modulation limit. In this case, the system can
be reduced to an unmodulated vector discrete nonlinear Schr\"odinger equation
with a rescaled SOC tunning parameter $\alpha$, which depends only on the ratio
between amplitude and frequency of the applied Zeeman field. The dependence of
the spectrum of the linear system on $\alpha$ has been analytically
characterized. In particular, we show that extremal curves (ground and highest
excited states) of the linear spectrum are continuous piecewise functions
(together with their derivatives) of $\alpha$, which consist of a finite number
of decreasing band lobes joined by constant lines. This structure also remains
in presence of not too large nonlinearities. Most important, the interactions
introduce a number of localized states in the band-gaps that undergo change of
properties as they collide with band lobes. The stability of ground states in
the presence of the modulating field has been demonstrated by real time
evolutions of the original (un-averaged) system. Localization properties of the
ground state induced by the SOC tuning, and a parameter design for possible
experimental observation have also been discussed.


title: Open Information Extraction

abstract:
  Open Information Extraction (Open IE) systems aim to obtain relation tuples
with highly scalable extraction in portable across domain by identifying a
variety of relation phrases and their arguments in arbitrary sentences. The
first generation of Open IE learns linear chain models based on unlexicalized
features such as Part-of-Speech (POS) or shallow tags to label the intermediate
words between pair of potential arguments for identifying extractable
relations. Open IE currently is developed in the second generation that is able
to extract instances of the most frequently observed relation types such as
Verb, Noun and Prep, Verb and Prep, and Infinitive with deep linguistic
analysis. They expose simple yet principled ways in which verbs express
relationships in linguistics such as verb phrase-based extraction or
clause-based extraction. They obtain a significantly higher performance over
previous systems in the first generation. In this paper, we describe an
overview of two Open IE generations including strengths, weaknesses and
application areas.


title: Violator spaces vs closure spaces

abstract:
  Violator Spaces were introduced by J. Matousek et al. in 2008 as
generalization of Linear Programming problems. Convex geometries were invented
by Edelman and Jamison in 1985 as proper combinatorial abstractions of
convexity. Convex geometries are defined by anti-exchange closure operators. We
investigate an interrelations between violator spaces and closure spaces and
show that violator mapping may be defined by a week version of closure
operators. Moreover, we prove that violator spaces with an unique basis
satisfies the anti-exchange and the Krein-Milman properties.


title: On the fibrewise effective Burnside $\infty$-category

abstract:
  Effective Burnside $\infty$-categories are the centerpiece of the
$\infty$-categorical approach to equivariant stable homotopy theory. In this
\'etude, we recall the construction of the twisted arrow $\infty$-category, and
we give a new proof that it is an $\infty$-category, using an extremely helpful
modification of an argument due to Joyal--Tierney. The twisted arrow
$\infty$-category is in turn used to construct the effective Burnside
$\infty$-category. We employ a variation on this theme to construct a fibrewise
effective Burnside $\infty$-category. To show that this constuctionworks
fibrewise, we introduce a fragment of a theory of what we call marbled
simplicial sets, and we use a yet further modified form of the Joyal--Tierney
argument.


title:
NIBLES - an HI census of stellar mass selected SDSS galaxies: I. The
  Nan\c{c}ay HI survey

abstract:
  To investigate galaxy properties as a function of their total stellar mass,
we obtained 21cm HI line observations at the 100-m class Nan\c{c}ay Radio
Telescope of 2839 galaxies from the Sloan Digital Sky Survey (SDSS) in the
Local Volume (900<cz<12,000 km/s), dubbed the Nan\c{c}ay Interstellar Baryons
Legacy Extragalactic Survey (NIBLES) sample. They were selected evenly over
their entire range of absolute SDSS z-band magnitudes (-13.5 to -24 mag), which
were used as a proxy for their stellar masses. Here, a first, global
presentation of the observations and basic results is given, their further
analysis will be presented in other papers in this series. The galaxies were
selected based on their properties, as listed in SDSS DR5. Comparing this
photometry to their total HI masses, we noted that, for a few percent, the SDSS
magnitudes appeared severely misunderestimated, as confirmed by our
re-measurements for selected objects. Although using the later DR9 results
eliminated this problem in most cases, 384 still required manual photometric
source selection. Usable HI spectra were obtained for 2600 galaxies, of which
1733 (67%) were clearly detected and 174 (7%) marginally. The spectra for 241
other observed galaxies could not be used for further analysis owing to
problems with either the HI or the SDSS data. We reached the target number of
about 150 sources per half-magnitude bin over the Mz range -16.5 to -23 mag.
Down to -21 mag the overall detection rate is rather constant at the ~75% level
but it starts to decline steadily towards the 30% level at -23 mag. Making
regression fits by comparing total HI and stellar masses for our sample,
including our conservatively estimated HI upper limits for non-detections, we
find the relationship log(M_HI/M*) = -0.59 log(M*) + 5.05, which lies
significantly below the relationship found in the M_HI/M* - M* plane when only
using HI detections.


title: Parallel local approximation MCMC for expensive models

abstract:
  Performing Bayesian inference via Markov chain Monte Carlo (MCMC) can be
exceedingly expensive when posterior evaluations invoke the evaluation of a
computationally expensive model, such as a system of partial differential
equations. In recent work [Conrad et al. JASA 2016, arXiv:1402.1694], we
described a framework for constructing and refining local approximations of
such models during an MCMC simulation. These posterior--adapted approximations
harness regularity of the model to reduce the computational cost of inference
while preserving asymptotic exactness of the Markov chain. Here we describe two
extensions of that work. First, we prove that samplers running in parallel can
collaboratively construct a shared posterior approximation while ensuring
ergodicity of each associated chain, providing a novel opportunity for
exploiting parallel computation in MCMC. Second, focusing on the
Metropolis--adjusted Langevin algorithm, we describe how a proposal
distribution can successfully employ gradients and other relevant information
extracted from the approximation. We investigate the practical performance of
our strategies using two challenging inference problems, the first in
subsurface hydrology and the second in glaciology. Using local approximations
constructed via parallel chains, we successfully reduce the run time needed to
characterize the posterior distributions in these problems from days to hours
and from months to days, respectively, dramatically improving the tractability
of Bayesian inference.


title: Charagram: Embedding Words and Sentences via Character n-grams

abstract:
  We present Charagram embeddings, a simple approach for learning
character-based compositional models to embed textual sequences. A word or
sentence is represented using a character n-gram count vector, followed by a
single nonlinear transformation to yield a low-dimensional embedding. We use
three tasks for evaluation: word similarity, sentence similarity, and
part-of-speech tagging. We demonstrate that Charagram embeddings outperform
more complex architectures based on character-level recurrent and convolutional
neural networks, achieving new state-of-the-art performance on several
similarity tasks.


title:
Hyper Normalisation and Conditioning for Discrete Probability
  Distributions

abstract:
  Normalisation in probability theory turns a subdistribution into a proper
distribution. It is a partial operation, since it is undefined for the zero
subdistribution. This partiality makes it hard to reason equationally about
normalisation. A novel description of normalisation is given as a
mathematically well-behaved total function. The output of this `hyper'
normalisation operation is a distribution of distributions. It improves
reasoning about normalisation.
  After developing the basics of this theory of (hyper) normalisation, it is
put to use in a similarly new description of conditioning, producing a
distribution of conditional distributions. This is used to give a clean
abstract reformulation of refinement in quantitative information flow.


title: Syntactic Phylogenetic Trees

abstract:
  In this paper we identify several serious problems that arise in the use of
syntactic data from the SSWL database for the purpose of computational
phylogenetic reconstruction. We show that the most naive approach fails to
produce reliable linguistic phylogenetic trees. We identify some of the sources
of the observed problems and we discuss how they may be, at least partly,
corrected by using additional information, such as prior subdivision into
language families and subfamilies, and a better use of the information about
ancient languages. We also describe how the use of phylogenetic algebraic
geometry can help in estimating to what extent the probability distribution at
the leaves of the phylogenetic tree obtained from the SSWL data can be
considered reliable, by testing it on phylogenetic trees established by other
forms of linguistic analysis. In simple examples, we find that, after
restricting to smaller language subfamilies and considering only those SSWL
parameters that are fully mapped for the whole subfamily, the SSWL data match
extremely well reliable phylogenetic trees, according to the evaluation of
phylogenetic invariants. This is a promising sign for the use of SSWL data for
linguistic phylogenetics.


title: A Ramsey Class for Steiner Systems

abstract:
  We construct a Ramsey class whose objects are Steiner systems. In contrast to
the situation with general $r$-uniform hypergraphs, it turns out that simply
putting linear orders on their sets of vertices is not enough for this purpose:
one also has to strengthen the notion of subobjects used from "induced
subsystems" to something we call "strongly induced subsystems".
  Moreover we study the Ramsey properties of other classes of Steiner systems
obtained from this class by either forgetting the order or by working with the
usual notion of subsystems. This leads to a perhaps surprising induced Ramsey
theorem in which designs get coloured.


title:
On Faster Convergence of Cyclic Block Coordinate Descent-type Methods
  for Strongly Convex Minimization

abstract:
  The cyclic block coordinate descent-type (CBCD-type) methods, which performs
iterative updates for a few coordinates (a block) simultaneously throughout the
procedure, have shown remarkable computational performance for solving strongly
convex minimization problems. Typical applications include many popular
statistical machine learning methods such as elastic-net regression, ridge
penalized logistic regression, and sparse additive regression. Existing
optimization literature has shown that for strongly convex minimization, the
CBCD-type methods attain iteration complexity of
$\mathcal{O}(p\log(1/\epsilon))$, where $\epsilon$ is a pre-specified accuracy
of the objective value, and $p$ is the number of blocks. However, such
iteration complexity explicitly depends on $p$, and therefore is at least $p$
times worse than the complexity $\mathcal{O}(\log(1/\epsilon))$ of gradient
descent (GD) methods. To bridge this theoretical gap, we propose an improved
convergence analysis for the CBCD-type methods. In particular, we first show
that for a family of quadratic minimization problems, the iteration complexity
$\mathcal{O}(\log^2(p)\cdot\log(1/\epsilon))$ of the CBCD-type methods matches
that of the GD methods in term of dependency on $p$, up to a $\log^2 p$ factor.
Thus our complexity bounds are sharper than the existing bounds by at least a
factor of $p/\log^2(p)$. We also provide a lower bound to confirm that our
improved complexity bounds are tight (up to a $\log^2 (p)$ factor), under the
assumption that the largest and smallest eigenvalues of the Hessian matrix do
not scale with $p$. Finally, we generalize our analysis to other strongly
convex minimization problems beyond quadratic ones.


title: Cluster structure and dynamics in gels and glasses

abstract:
  The dynamical arrest of gels is the consequence of a well defined structural
phase transition, leading to the formation of a spanning cluster of bonded
particles. The dynamical glass transition, instead, is not accompanied by any
clear structural signature. Nevertheless, both transitions are characterized by
the emergence of dynamical heterogeneities. Reviewing recent results from
numerical simulations, we discuss the behavior of dynamical heterogeneities in
different systems and show that a clear connection with the structure exists in
the case of gels. The emerging picture may be also relevant for the more
elusive case of glasses. We show, as an example, that the relaxation process of
a simple glass-forming model can be related to a reverse percolation transition
and discuss further perspective in this direction.


title: Evaluating Effectiveness of DART Buoy Networks

abstract:
  A performance measure for a DART tsunami buoy network has been developed. The
measure is based on a statistical analysis of simulated forecasts of wave
heights outside an impact site and how much the forecasts are degraded in
accuracy when one or more buoys are inoperative. The analysis uses simulated
tsunami height time series collected at each buoy from selected source segments
in the Short-term Inundation Forecast for Tsunamis (SIFT) database and involves
a set for 1000 forecasts for each buoy/segment pair at sites just offshore of
selected impact communities. Random error-producing scatter in the time series
is induced by uncertainties in the source location, addition of real oceanic
noise, and imperfect tidal removal. Comparison with an error-free standard
leads to root-mean-square errors (RMSEs) for DART buoys located near a
subduction zone. The RMSEs indicate which buoy provides the best forecast
(lowest RMSE) for sections of the zone, under a warning-time constraint for the
forecasts of 3 hrs. The analysis also shows how the forecasts are degraded
(larger minimum RMSE among the remaining buoys) when one or more buoys become
inoperative. The RMSEs also provide a way to assess array augmentation or
redesign such as moving buoys to more optimal locations. Examples are shown for
buoys off the Aleutian Islands and off the West Coast of South America for
impact sites at Hilo HI and along the U.S. West Coast (Crescent City CA and
Port San Luis CA). A simple measure (coded green, yellow or red) of the current
status of the network's ability to deliver accurate forecasts is proposed to
flag the urgency of buoy repair.


title:
Predicted electronic markers for polytypes of LaOBiS2 examined via
  angular resolved photoemission spectroscopy

abstract:
  The natural periodic stacking of symmetry-inequivalent planes in layered
compounds can lead to the formation of natural superlattices; albeit close in
total energy, (thus in their thermodynamic stability), such polytype
superlattices can exhibit different structural symmetries, thus have markedly
different electronic properties which can in turn be used as "structural
markers". We illustrate this general principle on the layered LaOBiS2 compound
where density-functional theory (DFT) calculations on the (BiS2)/(LaO)/(BiS2)
polytype superlattices reveal both qualitatively and quantitatively distinct
electronic structure markers associated with the Rashba physics, yet the total
energies are only ~ 0.1 meV apart. This opens the exciting possibility of
identifying subtle structural features via electronic markers. We show that the
pattern of removal of band degeneracies in different polytypes by the different
forms of symmetry breaking leads to new Rashba "mini gaps" with characteristic
Rashba parameters that can be determined from spectroscopy, thereby narrowing
down the physically possible polytypes. By identifying these distinct
DFT-predicted fingerprints via ARPES measurements on LaBiOS2 we found the
dominant polytype with small amounts of mixtures of other polytypes. This
conclusion, consistent with neutron scattering results, establishes ARPES
detection of theoretically established electronic markers as a powerful tool to
delineate energetically quasidegenerate polytypes.


title:
The surprising influence of late charged current weak interactions on
  Big Bang Nucleosynthesis

abstract:
  The weak interaction charged current processes ($\nu_e+n\leftrightarrow
p+e^-$, $\bar\nu_e +p\leftrightarrow n+e^+$, $n\leftrightarrow
p+e^-+\bar\nu_e$) interconvert neutrons and protons in the early universe and
have significant influence on Big Bang Nucleosynthesis (BBN) light-element
abundance yields, particulary that for $^{4}{\rm He}$. We demonstrate that the
influence of these processes is still significant even when they operate well
below temperatures $T\sim0.7\,{\rm MeV}$ usually invoked for "weak freeze-out,"
and in fact down nearly into the alpha-particle formation epoch ($T \approx
0.1\,{\rm MeV}$). This physics is correctly captured in commonly used BBN
codes, though this late-time, low-temperature persistent effect of the
isospin-changing weak processes, and the sensitivity of the associated rates to
lepton energy distribution functions and blocking factors are not widely
appreciated. We quantify this late-time influence by analyzing weak interaction
rate dependence on the neutron lifetime, lepton energy distribution functions,
entropy, the proton-neutron mass difference, and Hubble expansion rate. The
effects we point out here render BBN a keen probe of any beyond-standard-model
physics that alters lepton number/energy distributions, even subtly, in epochs
of the early universe all the way down to near $T=100\,{\rm keV}$.


title:
Convergence rate for a Gauss collocation method applied to constrained
  optimal control

abstract:
  A local convergence rate is established for a Gauss orthogonal collocation
method applied to optimal control problems with control constraints. If the
Hamiltonian possesses a strong convexity property, then the theory yields
convergence for problems whose optimal state and costate possess two square
integrable derivatives. The convergence theory is based on a stability result
for the sup-norm change in the solution of a variational inequality relative to
a 2-norm perturbation, and on a Sobolev space bound for the error in
interpolation at the Gauss quadrature points and the additional point -1. The
tightness of the convergence theory is examined using a numerical example.


title: Hidden charm octet tetraquarks from a diquark-antidiquark model

abstract:
  Four exotic charmonium-like states, i.e. $X(4140)$, $X(4274)$, $X(4500)$, and
$X(4700)$, have been observed very recently by LHCb Collaboration in the decay
process $B^+\to J/\psi \phi K^+$ using the 3${\rm fb}^{-1}$ data of $p\bar p$
collision at $\sqrt s= 7$ and $8$ TeV. In this paper, we investigate
systematically the properties of hidden charm tetraquark states. The hidden
charm tetraquarks form an octet configuration and a singlet configuration
according to flavor $SU(3)$ symmetry. Based on a diquark-antidiquark model, the
hidden charm tetraquarks spectra are given. The previous XYZ exotic states
altogether with the newly ones $X(4140)$, $X(4274)$, $X(4500)$, and $X(4700)$,
can be well classified into certain representations. The spin-parities and
masses of the XYZ are predicted, most of which are in agreement with the data.
We particularly find that $Z_c(4430)$ may be treated as the first radial
excitation of $Z_c(3900)$, while the $Y(1^{--})$ states can be obtained by the
first orbital excitation of the $X/Z$ states. Besides, we calculate the decay
widths of the hidden charm tetraquarks into two charmed mesons. This work gives
a general tetraquark description for the XYZ states, which is helpful to
uncover their inner structures.


title: Time-domain Boundedness of Noise-to-State Exponentially Stable Systems

abstract:
  In this paper we prove the time-domain boundedness for noise-to-state
exponentially stable systems, and further make an estimation of its lower bound
function, which allows to answer the question that how long the solution of a
stochastic noise-to-state exponentially stable system stays in the domain of
attraction and what happens with it if it escapes from this region for a while.
The results will complement the probability-domain boundedness of
noise-to-state exponentially stable systems, and provide a new insight into
noise-to-state exponential stability.


title:
Bounds on the Number of Measurements for Reliable Compressive
  Classification

abstract:
  This paper studies the classification of high-dimensional Gaussian signals
from low-dimensional noisy, linear measurements. In particular, it provides
upper bounds (sufficient conditions) on the number of measurements required to
drive the probability of misclassification to zero in the low-noise regime,
both for random measurements and designed ones. Such bounds reveal two
important operational regimes that are a function of the characteristics of the
source: i) when the number of classes is less than or equal to the dimension of
the space spanned by signals in each class, reliable classification is possible
in the low-noise regime by using a one-vs-all measurement design; ii) when the
dimension of the spaces spanned by signals in each class is lower than the
number of classes, reliable classification is guaranteed in the low-noise
regime by using a simple random measurement design. Simulation results both
with synthetic and real data show that our analysis is sharp, in the sense that
it is able to gauge the number of measurements required to drive the
misclassification probability to zero in the low-noise regime.


title: Mapping distributional to model-theoretic semantic spaces: a baseline

abstract:
  Word embeddings have been shown to be useful across state-of-the-art systems
in many natural language processing tasks, ranging from question answering
systems to dependency parsing. (Herbelot and Vecchi, 2015) explored word
embeddings and their utility for modeling language semantics. In particular,
they presented an approach to automatically map a standard distributional
semantic space onto a set-theoretic model using partial least squares
regression. We show in this paper that a simple baseline achieves a +51%
relative improvement compared to their model on one of the two datasets they
used, and yields competitive results on the second dataset.


title: Parallelotope tilings and $q$-decomposition numbers

abstract:
  We provide closed formulas for a large subset of the canonical basis vectors
of the Fock space representation of $U_q(\widehat{\mathfrak{sl}}_e)$. These
formulas arise from parallelotopes which assemble to form polytopal complexes.
The subgraphs of the $\mathrm{Ext}^1$-quivers of $v$-Schur algebras at complex
$e$-th roots of unity generated by simple modules corresponding to these
canonical basis vectors are given by the $1$-skeletons of the polytopal
complexes.


title:
Estimating the number of species to attain sufficient representation in
  a random sample

abstract:
  The statistical problem of using an initial sample to estimate the number of
species in a larger sample has found important applications in fields far
removed from ecology. Here we address the general problem of estimating the
number of species that will be represented by at least a number r of
observations in a future sample. The number r indicates species with sufficient
observations, which are commonly used as a necessary condition for any robust
statistical inference. We derive a procedure to construct consistent estimators
that apply universally for a given population: once constructed, they can be
evaluated as a simple function of r. Our approach is based on a relation
between the number of species represented at least r times and the higher
derivatives of the expected number of species discovered per unit of time.
Combining this relation with a rational function approximation, we propose
nonparametric estimators that are accurate for both large values of r and
long-range extrapolations. We further show that our estimators retain
asymptotic behaviors that are essential for applications on large-scale
datasets. We evaluate the performance of this approach by both simulation and
real data applications for inferences of the vocabulary of Shakespeare and
Dickens, the topology of a Twitter social network, and molecular diversity in
DNA sequencing data.


title: Mobile Privacy-Preserving Crowdsourced Data Collection in the Smart City

abstract:
  Smart cities rely on dynamic and real-time data to enable smart urban
applications such as intelligent transport and epidemics detection. However,
the streaming of big data from IoT devices, especially from mobile platforms
like pedestrians and cars, raises significant privacy concerns.
  Future autonomous vehicles will generate, collect and consume significant
volumes of data to be utilized in delivering safe and efficient transportation
solutions. The sensed data will, inherently, contain personally identifiable
and attributable information - both external (other vehicles, environmental)
and internal (driver, passengers, devices).
  The autonomous vehicles are connected to the infrastructure cloud (e.g.,
Amazon), the edge cloud, and also the mobile cloud (vehicle to vehicle).
Clearly these different entities must co-operate and interoperate in a timely
fashion when routing and transferring the highly dynamic data. In order to
maximise the availability and utility of the sensed data, stakeholders must
have confidence that the data they transmit, receive, aggregate and reason on
is appropriately secured and protected throughout. There are many different
metaphors for providing end-to-end security for data exchanges, but they
commonly require a management and control sidechannel.
  This work proposes a scalable smart city privacy-preserving architecture
named Authorized Analytics that enables each node (e.g. vehicle) to divulge
(contextually) local privatised data. Authorized Analytics is shown to scale
gracefully to IoT scope deployments.


title:
Local exact boundary controllability of entropy solutions to a class of
  hyperbolic systems of conservation laws

abstract:
  In this paper, we study the local exact boundary controllability of entropy
solutions to a class linearly degenerate hyperbolic systems of conservation
laws with constant multiplicity. The authors prove the two-sided boundary
controllability, one-sided boundary controllability and two-sided
controllability with less controls, by applying the strategy used originally
for classical solutions with essential modifications. Our constructive method
is based on the well-posedness of semi-global solutions constructed by the
limit of $ \e $-approximate front tracking solutions to the mixed
initial-boundary value problem with general nonlinear boundary conditions and
some further properties on both $ \e $-approximate front tracking solutions and
entropy solutions.


title: Hall Effect in the Abrikosov Lattice of Type-II Superconductors

abstract:
  We study vortex charging caused by the Lorentz force on supercurrent based on
the augmented quasiclassical equa- tions of superconductivity. Our numerical
study on an s-wave vortex lattice in the range $H_{{\rm{c}}1} < H <
H_{{\rm{c}}2}$ reveals that each vortex core with a single flux quantum also
accumulates charge due to the circulating supercurrent and has a Hall voltage
across the core. The field dependence of the charge density at the core center
is well described by $H(H_{{\rm{c}}2}-H)$ with a peak near $H_{{\rm{c}}2}/2$
originating from competition between the increasing magnetic field and the
decreasing pair potential. The peak value of the accumulated charge in a core
region of radius $0.5\xi_0$ is estimated to be about $\eta\Delta_{0}/(k_{\rm
F}\xi_0)\times|e|$ C per $\Delta z=1$ nm along the flux line at low
temperatures, where $\eta\equiv\pi\epsilon_0\Delta z/|e|^2=1.09\times10^{18}$
${\rm{J^{-1}}}$ with $e<0$ the charge of an electron, $\Delta_0$ the energy gap
at $T=0$, $k_{\rm F}$ the Fermi wave number, and $\xi_0$ the coherence length
at $T=0$.


title:
Dynamic Modulation of the Transport Properties of the LaAlO3/SrTiO3
  Interface Using Uniaxial Strain

abstract:
  Among the interfacial transport modulations to the LaAlO3/SrTiO3 (LAO/STO)
heterostructure, mechanical strain has been proven to be an effective approach
by growing the LAO/STO films on different substrates with varying lattice
mismatches to STO. However, this lattice-mismatch-induced strain effect is
static and biaxial, hindering the study of the strain effect in a dynamic way.
In this work we realize dynamic and uniaxial strain to the LAO/STO oxide
heterostructure at low temperature, through mechanical coupling from a
magnetostrictive template. This anisotropic strain results in symmetry breaking
at the interface and induces further splitting of the electronic band structure
and therefore produces different conductivities along the x and y in-plane
directions. In particular, we observe that along the strained direction the
interface conductivity decreases by up to 70% under a tensile strain, while it
increases by 6.8% under a compressive strain at 2 K. Also, it is revealed that
the modulation on the interfacial transport property can be anisotropic, i.e.,
the resistance changes differently when an excitation current is parallel or
perpendicular to the strain direction. This approach of strain engineering
provides another degree of freedom for control of transport properties of oxide
heterostructures and opens an additional way to investigate strain effects in
materials science.


title:
A sharp recovery condition for block sparse signals by block orthogonal
  multi-matching pursuit

abstract:
  We consider the block orthogonal multi-matching pursuit (BOMMP) algorithm for
the recovery of block sparse signals. A sharp bound is obtained for the exact
reconstruction of block $K$-sparse signals via the BOMMP algorithm in the
noiseless case, based on the block restricted isometry constant (block-RIC).
Moreover, we show that the sharp bound combining with an extra condition on the
minimum $\ell_2$ norm of nonzero blocks of block $K-$sparse signals is
sufficient to recover the true support of block $K$-sparse signals by the BOMMP
in the noise case. The significance of the results we obtain in this paper lies
in the fact that making explicit use of block sparsity of block sparse signals
can achieve better recovery performance than ignoring the additional structure
in the problem as being in the conventional sense.


title:
The Benefits of Word Embeddings Features for Active Learning in Clinical
  Information Extraction

abstract:
  This study investigates the use of unsupervised word embeddings and sequence
features for sample representation in an active learning framework built to
extract clinical concepts from clinical free text. The objective is to further
reduce the manual annotation effort while achieving higher effectiveness
compared to a set of baseline features. Unsupervised features are derived from
skip-gram word embeddings and a sequence representation approach. The
comparative performance of unsupervised features and baseline hand-crafted
features in an active learning framework are investigated using a wide range of
selection criteria including least confidence, information diversity,
information density and diversity, and domain knowledge informativeness. Two
clinical datasets are used for evaluation: the i2b2/VA 2010 NLP challenge and
the ShARe/CLEF 2013 eHealth Evaluation Lab. Our results demonstrate significant
improvements in terms of effectiveness as well as annotation effort savings
across both datasets. Using unsupervised features along with baseline features
for sample representation lead to further savings of up to 9% and 10% of the
token and concept annotation rates, respectively.


title:
Observation of the topological soliton state in the Su-Schrieffer-Heeger
  model

abstract:
  The Su-Schrieffer-Heeger (SSH) model, which captures the most striking
transport properties of the conductive organic polymer $trans$-polyacetylene,
provides perhaps the most basic model system supporting topological
excitations. The alternating bond pattern of polyacetylene chains is captured
by the bipartite sublattice structure of the SSH model, emblematic of
one-dimensional chiral symmetric topological insulators. This structure
supports two distinct nontrivial topological phases, which, when interfaced
with one another or with a topologically trivial phase, give rise to
topologically-protected, dispersionless boundary states. Using $^{87}$Rb atoms
in a momentum-space lattice, we realize fully-tunable condensed matter
Hamiltonians, allowing us to probe the dynamics and equilibrium properties of
the SSH model. We report on the experimental quantum simulation of this model
and observation of the localized topological soliton state through quench
dynamics, phase-sensitive injection, and adiabatic preparation.


title: Excited bottom and bottom-strange mesons in the quark model

abstract:
  In order to understand the possible $q\bar{q}$ quark-model assignments of the
$B_J(5840)$ and $B_J(5960)$ recently reported by the LHCb Collaboration, we
evaluate mass spectra, strong decays, and radiative decays of bottom and
bottom-strange mesons in a nonrelativistic quark model. Comparing these
predictions with the relevant experimental results, we suggest that the
$B_J(5840)$ and $B_J(5960)$ can be identified as the $B(2^1S_0)$ and
$B(1^3D_3)$, respectively, and the $B(5970)$ reported by the CDF Collaboration
can be interpreted as the $B(2^3S_1)$ or $B(1^3D_3)$. Further precise
measurements of the width, spin and decay modes of the $B(5970)$ are needed to
distinguish these two assignments. These predictions of bottom and
bottom-strange mesons can provide useful information to further experimental
investigations.


title:
Neutron Beam Tests of Barium Fluoride Crystal for Dark Matter Direct
  Detection

abstract:
  In order to test the capabilities of Barium Fluoride (BaF2) Crystal for dark
matter direct detection, nuclear recoils are studied with mono-energetic
neutron beam. The energy spectra of nuclear recoils, quenching factors for
elastic scattering neutrons and discrimination capability between neutron
inelastic scattering events and {\gamma} events are obtained for various recoil
energies of the F content in BaF2.


title:
Powerful and Tunable THz Emitters Based on the Fe/Pt Magnetic
  Heterostructure

abstract:
  In this work, we report our study on the THz emission in Fe/Pt magnetic
heterostructures. We have carried out a comprehensive investigation of THz
emission from Fe/Pt magnetic heterostructures, employing time-domain THz
spectroscopy. We reveal that by properly tuning the thickness of Fe or Pt
layer, THz emission can be greatly improved in this type of heterostructure. We
further demonstrate that the THz field strength emitted from a newly designed
multilayer (Pt/Fe/MgO)$_n$ with n=3 can reach a value of ~1.6 kV/cm, which is
comparable to the values from the conventional GaAs antenna with a bias of 4
kV/cm, and the nonlinear crystals, e.g., 100 micrometer GaP and 2 mm ZnTe. For
the first time, the intensity and spectrum of THz wave is demonstrated to be
tunable by the magnetic field applied on the patterned magnetic Fe/Pt
heterostructures. These findings thus promise novel approaches to fabricate
powerful and tunable THz emitters based on magnetic heterostructure.


title: Efficient Activity Detection in Untrimmed Video with Max-Subgraph Search

abstract:
  We propose an efficient approach for activity detection in video that unifies
activity categorization with space-time localization. The main idea is to pose
activity detection as a maximum-weight connected subgraph problem. Offline, we
learn a binary classifier for an activity category using positive video
exemplars that are "trimmed" in time to the activity of interest. Then, given a
novel \emph{untrimmed} video sequence, we decompose it into a 3D array of
space-time nodes, which are weighted based on the extent to which their
component features support the learned activity model. To perform detection, we
then directly localize instances of the activity by solving for the
maximum-weight connected subgraph in the test video's space-time graph. We show
that this detection strategy permits an efficient branch-and-cut solution for
the best-scoring---and possibly non-cubically shaped---portion of the video for
a given activity classifier. The upshot is a fast method that can search a
broader space of space-time region candidates than was previously practical,
which we find often leads to more accurate detection. We demonstrate the
proposed algorithm on four datasets, and we show its speed and accuracy
advantages over multiple existing search strategies.


title: Development of four kinds of waveguide power divider for S band

abstract:
  Four kinds of waveguide power dividers with different structures working at
2.856 GHz are developed. By comparing the simulation performances of these four
structures, the power divider with matching rod in the middle of its structure
has got the best performance and finally be chosen for fabrication. The
prototype has got qualified microwave measurement results as well as the high
vacuum performance. It also works stable during the whole progress of microwave
commissioning.


title: Binary Codes with Locality for Four Erasures

abstract:
  In this paper, codes with locality for four erasures are considered. An upper
bound on the rate of codes with locality with sequential recovery from four
erasures is derived. The rate bound derived here is field independent. An
optimal construction for binary codes meeting this rate bound is also provided.
The construction is based on regular graphs of girth $6$ and employs the
sequential approach of locally recovering from multiple erasures. An extension
of this construction that generates codes which can sequentially recover from
five erasures is also presented.


title: Equation-free analysis of a dynamically evolving multigraph

abstract:
  In order to illustrate the adaptation of traditional continuum numerical
techniques to the study of complex network systems, we use the equation-free
framework to analyze a dynamically evolving multigraph. This approach is based
on coupling short intervals of direct dynamic network simulation with
appropriately-defined lifting and restriction operators, mapping the detailed
network description to suitable macroscopic (coarse-grained) variables and
back. This enables the acceleration of direct simulations through Coarse
Projective Integration (CPI), as well as the identification of coarse
stationary states via a Newton-GMRES method. We also demonstrate the use of
data-mining, both linear (principal component analysis, PCA) and nonlinear
(diffusion maps, DMAPS) to determine good macroscopic variables (observables)
through which one can coarse-grain the model. These results suggest methods for
decreasing simulation times of dynamic real-world systems such as
epidemiological network models. Additionally, the data-mining techniques could
be applied to a diverse class of problems to search for a succint,
low-dimensional description of the system in a small number of variables.


title:
A finite element approach to self-consistent field theory calculations
  of multiblock polymers

abstract:
  Self-consistent field theory (SCFT) has proven to be a powerful tool for
modeling equilibrium microstructures of soft materials, particularly for
multiblock polymers. A very successful approach to numerically solving the SCFT
set of equations is based on using a spectral approach. While widely
successful, this approach has limitations especially in the context of current
technologically relevant applications. These limitations include non-trivial
approaches for modeling complex geometries, difficulties in extending to
non-periodic domains, as well as non-trivial extensions for spatial adaptivity.
As a viable alternative to spectral schemes, we develop a finite element
formulation of the SCFT paradigm for calculating equilibrium polymer
morphologies. We discuss the formulation and address implementation challenges
that ensure accuracy and efficiency. We explore higher order chain contour
steppers that are efficiently implemented with Richardson Extrapolation. This
approach is highly scalable and suitable for systems with arbitrary shapes. We
show spatial and temporal convergence and illustrate scaling on up to 2048
cores. Finally, we illustrate confinement effects for selected complex
geometries. This has implications for materials design for nanoscale
applications where dimensions are such that equilibrium morphologies
dramatically differ from the bulk phases.


title: Quantum thermal transport in stanene

abstract:
  By way of the non-equilibrium Green's function simulations and analytical
expressions, the quantum thermal conductance of stanene is studied. We find
that, due to the existence of Dirac fermion in stanene, the ratio of electron
thermal conductance and electric conductance becomes a
chemical-potential-dependent quantity, violating the Wiedemann-Franz law. This
finding is applicable to any two-dimensional (2D) materials that possess
massless Dirac fermions. In strong contrast to the negligible electronic
contribution in graphene, surprisingly, the electrons and phonons in stanene
carry a comparable heat current. The unusual behaviours in stanene widen our
knowledge of quantum thermal transport in 2D materials.


title:
Discontinuity in the asymptotic behavior of planar orthogonal
  polynomials under a perturbation of the Gaussian weight

abstract:
  We consider the orthogonal polynomials, $\{P_n(z)\}_{n=0,1,\cdots}$, with
respect to the measure $$|z-a|^{2c} e^{-N|z|^2}dA(z)$$ supported over the whole
complex plane, where $a>0$, $N>0$ and $c>-1$. We look at the scaling limit
where $n$ and $N$ tend to infinity while keeping their ratio, $n/N$, fixed. The
support of the limiting zero distribution is given in terms of certain
"limiting potential-theoretic skeleton" of the unit disk. We show that, as we
vary $c$, both the skeleton and the asymptotic distribution of the zeros behave
discontinuously at $c=0$. The smooth interpolation of the discontinuity is
obtained by the further scaling of $c=e^{-\eta N}$ in terms of the parameter
$\eta\in[0,\infty).$


title:
Capacity Bounds for Networks with Correlated Sources and
  Characterisation of Distributions by Entropies

abstract:
  Characterising the capacity region for a network can be extremely difficult.
Even with independent sources, determining the capacity region can be as hard
as the open problem of characterising all information inequalities. The
majority of computable outer bounds in the literature are relaxations of the
Linear Programming bound which involves entropy functions of random variables
related to the sources and link messages. When sources are not independent, the
problem is even more complicated. Extension of Linear Programming bounds to
networks with correlated sources is largely open. Source dependence is usually
specified via a joint probability distribution, and one of the main challenges
in extending linear program bounds is the difficulty (or impossibility) of
characterising arbitrary dependencies via entropy functions. This paper tackles
the problem by answering the question of how well entropy functions can
characterise correlation among sources. We show that by using carefully chosen
auxiliary random variables, the characterisation can be fairly "accurate" Using
such auxiliary random variables we also give implicit and explicit outer bounds
on the capacity of networks with correlated sources. The characterisation of
correlation or joint distribution via Shannon entropy functions is also
applicable to other information measures such as Renyi entropy and Tsallis
entropy.


title: $a_0(980)$ photoproduction in the coupled channel model

abstract:
  We calculated the coupled channel photoproduction amplitudes of the scalar
isovector resononace $a_0(980)$, which include the $\pi\eta$, $K^+K^-$ and
$K^0\overline{K^0}$ intermediate states. Based on them we obtained the mass
distribution in the $\pi\eta$ channel at photon energy $E_\gamma$=7 GeV,
corresponding to energy accissible in new JLab experiments CLAS12 and GlueX. We
also analyzed the shape of mass distribution as a function of the phase of the
background amplitude.


title: Reaching Agreement in Quantum Hybrid Networks

abstract:
  We consider a basic quantum hybrid network model consisting of a number of
nodes each holding a qubit, for which the aim is to drive the network to a
consensus in the sense that all qubits reach a common state. Projective
measurements are applied serving as control means, and the measurement results
are exchanged among the nodes via classical communication channels. We show how
to carry out centralized optimal path planning for this network with all-to-all
classical communications, in which case the problem becomes a stochastic
optimal control problem with a continuous action space. To overcome the
computation and communication obstacles facing the centralized solutions, we
also develop a distributed Pairwise Qubit Projection (PQP) algorithm, where
pairs of nodes meet at a given time and respectively perform measurements at
their geometric average. We show that the qubit states are driven to a
consensus almost surely along the proposed PQP algorithm, and that the expected
qubit density operators converge to the average of the network's initial
values.


title: Higher cohomology operations and R-completion

abstract:
  Let $R=\mathbb{F}_p$ or a field of characteristic $0$. For each $R$-good
topological space $Y$, we define a collection of higher cohomology operations
which, together with the cohomology algebra $H^*(Y;R)$ suffice to determine $Y$
up to $R$-completion. We also provide a similar collection of higher cohomology
operations which determine when two maps $f_0,f_1: Z\to Y$ between $R$-good
spaces(inducing the same algebraic homomorphism $H^*(Y;R)\to H^*(Z;R)$) are
$R$-equivalent.


title: Comparison of the Smith-Purcell Radiation Yield for Different Models

abstract:
  Smith-Purcell radiation is used in several applications including the
measurement of the longitudinal profile of electron bunches. A correct
reconstruction of such profile requires a good understanding of the underlying
model. We have compared the leading models of Smith-Purcell radiation and shown
that they are in agreement within the experimental errors.


title:
Decay of the Higgs boson to $\tau^- \tau^+$ and non-Hermiticity of the
  Yukawa interaction

abstract:
  The issue of Hermiticity of the Higgs boson interaction with fermions is
addressed. A model for non-Hermitian Yukawa interaction is proposed and
approximation of one fermion generation is considered. Symmetry properties of
the corresponding $h f \bar{f}$ Lagrangian with respect to the discrete P, C
and T transformations are analyzed, and the modified Dirac equation for the
free fermion is studied. Longitudinal polarization of the fermions in the decay
$h \to f \bar{f}$, which arises due to non-Hermiticity of the $h f \bar{f}$
interaction, is discussed. It is suggested to study effects of this
non-Hermiticity in the decay $h \to \tau^- \tau^+ \to \mu^- {\bar \nu}_\mu
\nu_\tau \, \mu^+ \nu_\mu {\bar \nu}_\tau$, for which observables (asymmetries)
are constructed which take nonzero values for a non-Hermitian $h \tau^- \tau^+$
interaction. These asymmetries are analyzed for various configurations of the
muon energies.


title: Elastic Model for Dinucleosome Structure and Energy

abstract:
  The equilibrium structure of a Dinucleosome is studied using an elastic model
that takes into account the force and torque balance conditions. Using the
proper boundary conditions, it is found that the conformational energy of the
problem does not depend on the length of the linker DNA. In addition it is
shown that the two histone octamers are almost perpendicular to each other and
the linker DNA in short lengths is almost straight. These findings could shed
some light on the role of DNA elasticity in the chromatin structure.


title: Hypergraph Modelling for Geometric Model Fitting

abstract:
  In this paper, we propose a novel hypergraph based method (called HF) to fit
and segment multi-structural data. The proposed HF formulates the geometric
model fitting problem as a hypergraph partition problem based on a novel
hypergraph model. In the hypergraph model, vertices represent data points and
hyperedges denote model hypotheses. The hypergraph, with large and
"data-determined" degrees of hyperedges, can express the complex relationships
between model hypotheses and data points. In addition, we develop a robust
hypergraph partition algorithm to detect sub-hypergraphs for model fitting. HF
can effectively and efficiently estimate the number of, and the parameters of,
model instances in multi-structural data heavily corrupted with outliers
simultaneously. Experimental results show the advantages of the proposed method
over previous methods on both synthetic data and real images.


title: Classical limit of diagonal form factors and HHL correlators

abstract:
  We propose an expression for the classical limit of diagonal form factors in
which we integrate the corresponding observable over the moduli space of
classical solutions. In infinite volume the integral has to be regularized by
proper subtractions and we present the one, which corresponds to the classical
limit of the connected diagonal form factors. In finite volume the integral is
finite and can be expressed in terms of the classical infinite volume diagonal
form factors and subvolumes of the moduli space. We analyze carefully the
periodicity properties of the finite volume moduli space and found a classical
analogue of the Bethe-Yang equations. By applying the results to the
heavy-heavy-light three point functions we can express their strong coupling
limit in terms of the classical limit of the sine-Gordon diagonal form factors.


title:
Flow of Power-Law Liquids in a Hele-Shaw Cell Driven by Non-Uniform
  Electroosmotic Slip in the Case of Strong Depletion

abstract:
  We analyze flow of non-Newtonian fluids in a Hele-Shaw cell, subjected to
spatially non-uniform electroosmotic slip. Motivated by their potential use for
increasing the characteristic pressure fields, we specifically focus on
power-law fluids with wall depletion properties. We derive a p-Poisson equation
governing the pressure field, as well as a set of linearized equations
representing its asymptotic approximation for weakly non-Newtonian behavior. To
investigate the effect of non-Newtonian properties on the resulting fluidic
pressure and velocity, we consider several configurations in one- and
two-dimensions, and calculate both exact and approximate solutions. We show
that the asymptotic approximation is in good agreement with exact solutions
even for fluids with significant non-Newtonian behavior, allowing its use in
the analysis and design of microfluidic systems involving electro-kinetic
transport of such fluids.


title: Monopole excitation of the Hoyle state and linear-chain state in 12C

abstract:
  Background: Two new $J^\pi=0^+$ states are recently observed around a few MeV
above the Hoyle state (the second $0^+$ state in 12C). The characters of them
are only poorly discussed in theory and are still mysterious.
  Purpose: I give for the first time a comprehensive understanding of the
structures of the $0^+$ states by analyzing their wave functions, and discuss
relationship with the Hoyle state, similarities, and differences between the
states.
  Method: I extend a microscopic $\alpha$-cluster model called
Tohsaki-Horiuchi-Schuck-R\"opke (THSR) wave function so as to incorporate
$2\alpha+\alpha$ asymmetric configuration explicitly. The so-called
$r^2$-constraint method to effectively eliminate spurious continuum components
is also used.
  Results: The $0_3^+$ state is shown to have a very large squared overlap with
a single configuration of the extended THSR wave function in an orthogonal
space to the Hoyle state as well as to the ground state. The $0_4^+$ state has
a maximal squared overlap with a single extended THSR wave function with an
extremely prolately-deformed shape.
  Conclusions: The $0_3^+$ state appears as a family of the Hoyle state to have
a higher nodal structure in the internal motions of the $3\alpha$ clusters, due
to the orthogonalization to the Hoyle state. The $0_4^+$ state dominantly has a
linear-chain structure, where the $3\alpha$ clusters move freely in a
non-localized way, like a one-dimensional gas of the $3\alpha$ clusters.


title: Barycentric Subspace Analysis on Manifolds

abstract:
  This paper investigates the generalization of Principal Component Analysis
(PCA) to Riemannian manifolds. We first propose a new and general type of
family of subspaces in manifolds that we call barycentric subspaces. They are
implicitly defined as the locus of points which are weighted means of $k+1$
reference points. As this definition relies on points and not on tangent
vectors, it can also be extended to geodesic spaces which are not Riemannian.
For instance, in stratified spaces, it naturally allows principal subspaces
that span several strata, which is impossible in previous generalizations of
PCA. We show that barycentric subspaces locally define a submanifold of
dimension k which generalizes geodesic subspaces.Second, we rephrase PCA in
Euclidean spaces as an optimization on flags of linear subspaces (a hierarchy
of properly embedded linear subspaces of increasing dimension). We show that
the Euclidean PCA minimizes the Accumulated Unexplained Variances by all the
subspaces of the flag (AUV). Barycentric subspaces are naturally nested,
allowing the construction of hierarchically nested subspaces. Optimizing the
AUV criterion to optimally approximate data points with flags of affine spans
in Riemannian manifolds lead to a particularly appealing generalization of PCA
on manifolds called Barycentric Subspaces Analysis (BSA).


title: Tight Lower Bounds for Multiplicative Weights Algorithmic Families

abstract:
  We study the fundamental problem of prediction with expert advice and develop
regret lower bounds for a large family of algorithms for this problem. We
develop simple adversarial primitives, that lend themselves to various
combinations leading to sharp lower bounds for many algorithmic families. We
use these primitives to show that the classic Multiplicative Weights Algorithm
(MWA) has a regret of $\sqrt{\frac{T \ln k}{2}}$, there by completely closing
the gap between upper and lower bounds. We further show a regret lower bound of
$\frac{2}{3}\sqrt{\frac{T\ln k}{2}}$ for a much more general family of
algorithms than MWA, where the learning rate can be arbitrarily varied over
time, or even picked from arbitrary distributions over time. We also use our
primitives to construct adversaries in the geometric horizon setting for MWA to
precisely characterize the regret at $\frac{0.391}{\sqrt{\delta}}$ for the case
of $2$ experts and a lower bound of $\frac{1}{2}\sqrt{\frac{\ln k}{2\delta}}$
for the case of arbitrary number of experts $k$.


title:
Form Follows Function -- Do algorithms and applications challenge or
  drag behind the hardware evolution?

abstract:
  We summarise some of the key statements made at the workshop Form Follows
Function at ISC High Performance 2016. The summary highlights what type of
co-design the presented projects experience; often in the absence of an
explicit co-design agenda. Their software development picks up hardware trends
but it also influences the hardware development. Observations illustrate that
this cycle not always is optimal for both sides as it is not proactively
steered. Key statements characterise ideas how it might be possible to
integrate both hardware and software creation closer to the best of both
worlds---again even without classic co-design in mind where new pieces of
hardware are created. The workshop finally identified three development idioms
that might help to improve software and system design with respect to emerging
hardware.


title: Maximum principles for nonlocal parabolic Waldenfels operators

abstract:
  As a class of L\'evy type Markov generators, nonlocal Waldenfels operators
appear naturally in the context of investigating stochastic dynamics under
L\'evy fluctuations and constructing Markov processes with boundary conditions
(in particular the construction with jumps). This work is devoted to prove the
weak and strong maximum principles for `parabolic' equations with nonlocal
Waldenfels operators. Applications in stochastic differential equations with
$\alpha$-stable L\'evy processes are presented to illustrate the maximum
principles.


title: Non-Markovian dynamics in the extended cluster spin-1/2 XX chain

abstract:
  We study the dynamics of entanglement in the extended cluster spin-1/2 XX
chain, equivalent to a 1D spin-1/2 XX model with three-spin interaction (TSI).
Selecting the nearest neighbor pair spins as an open quantum system, the rest
of the chain plays the role of environment. The two-spin Heisenberg and the TSI
interaction are responsible for coupling between system and environment. We
show the existence of a critical value in the TSI, where the dynamics of
concurrence changes from Markovian to the non-Markovian. In the region with the
non-Markovian dynamics, entanglement sudden death in the system is observed. By
focusing on the nearest neighbor pair spins of the environment, we have showed
that the dynamics of entanglement in the environment is sensitive to the
Markovian and non-Markovian regions.


title:
Suppression of scattering for small dielectric particles: an anapole
  mode and invisibility

abstract:
  We reveal that an isotropic homogeneous subwavelength particle with a high
refractive index can produce ultra-weak total scattering due to vanishing
contribution of the electric dipole moment. This effect can be explained with
the help of the Fano resonance and scattering efficiency associated with the
excitation of an anapole mode. The latter is a nonradiative mode emerging from
destructive interference of electric and toroidal dipole moments, and it can be
employed for a design of highly transparent optical materials.


title: Boosting Magnetic Reconnection by Viscosity and Thermal Conduction

abstract:
  Nonlinear evolution of magnetic reconnection is investigated by means of
magnetohydrodynamic simulations including uniform resistivity, uniform
viscosity, and anisotropic thermal conduction. When viscosity exceeds
resistivity (the magnetic Prandtl number Prm > 1), the viscous dissipation
dominates outflow dynamics and leads to the decrease in the plasma density
inside a current sheet. The low-density current sheet supports the excitation
of the vortex. The thickness of the vortex is broader than that of the current
for Prm > 1. The broader vortex flow more efficiently carries the upstream
magnetic flux toward the reconnection region, and consequently boosts the
reconnection. The reconnection rate increases with viscosity provided that
thermal conduction is fast enough to take away the thermal energy increased by
the viscous dissipation (the fluid Prandtl number Pr < 1). The result suggests
the need to control the Prandtl numbers for the reconnection against the
conventional resistive model.


title: A microscopic theory for ultra-near-field radiation

abstract:
  Using the nonequilibrium Green's function (NEGF) formalism, we propose a
microscopic theory for near-field radiative heat transfer between metal plates.
Tight-binding models for the electrons are coupled to the electromagnetic field
continuum. Our approach differs from the established ones based on
fluctuational electrodynamics, in that it describes truly nonequilibrium steady
states, and is nonlocal in system's dielectric properties. For a two
quantum-dot model a new length scale emerges at which the heat current shows a
peak. This length scale is related to the physics of parallel plate capacitors.
The three-dimensional model results are consistent with the theory of Polder
and van Hove except at very short distances.


title:
Bipartisanship breakdown, functional networks and forensic analysis in
  Spanish 2015 and 2016 national elections

abstract:
  In this paper we present a social network and forensic analysis of the vote
counts of Spanish national elections that took place in December 2015 and their
sequel in June 2016. Vote counts are extracted at the level of municipalities,
yielding an unusually high resolution dataset with over 8000 samples. We
initially consider the phenomenon of Bipartisanship breakdown by analysing
spatial distributions of several Bipartisanship indices. We find that such
breakdown is more prominent close to cosmopolite and largely populated areas
and less important in rural areas where Bipartisanship still prevails, and its
evolution mildly consolidates in the 2016 round, with some evidence of
Bipartisanship reinforcement which we hypothesize to be due to psychological
mechanisms of risk aversion. On a third step we explore to which extent vote
data are faithful by applying forensic techniques to vote statistics. We first
explore the conformance of first digit distributions to Benford's law for each
of the main political parties. The results and interpretations are mixed and
vary across different levels of aggregation, finding a general good
quantitative agreement at the national scale for both municipalities and
precincts but finding systematic nonconformance at the level of individual
precincts. As a complementary metric, we further explore the co-occurring
statistics of voteshare and turnout, finding a mild tendency in the clusters of
the conservative party to smear out towards the area of high turnout and
voteshare, what has been previously interpreted as a possible sign of
incremental fraud. In every case results are qualitatively similar between 2015
and 2016 elections.


title:
Staggered Time Average Algorithm for Stochastic Non-smooth Optimization
  with O(1/T) Convergence

abstract:
  Stochastic non-smooth convex optimization constitutes a class of problems in
machine learning and operations research. This paper considers minimization of
a non-smooth function based on stochastic subgradients. When the function has a
locally polyhedral structure, a staggered time average algorithm is proven to
have O(1/T) convergence rate. A more general convergence result is proven when
the locally polyhedral assumption is removed. In that case, the convergence
bound depends on the curvature of the function near the minimum. Finally, the
locally polyhedral assumption is shown to improve convergence beyond O(1/T) for
a special case of deterministic problems.


title: Connected formulas for amplitudes in standard model

abstract:
  Witten's twistor string theory has led to new representations of S-matrix in
massless QFT as a single object, including Cachazo-He-Yuan formulas in general
and connected formulas in four dimensions. As a first step towards more
realistic processes of the standard model, we extend the construction to QCD
tree amplitudes with massless quarks and those with a Higgs boson. For both
cases, we find connected formulas in four dimensions for all multiplicities
which are very similar to the one for Yang-Mills amplitudes. The formula for
quark-gluon color-ordered amplitudes differs from the pure-gluon case only by a
Jacobian factor that depends on flavors and orderings of the quarks. In the
formula for Higgs plus multi-parton amplitudes, the massive Higgs boson is
effectively described by two additional massless legs which do not appear in
the Parke-Taylor factor. The latter also represents the first
twistor-string/connected formula for form factors.