title:
CP-mtML: Coupled Projection multi-task Metric Learning for Large Scale
  Face Retrieval

abstract:
  We propose a novel Coupled Projection multi-task Metric Learning (CP-mtML)
method for large scale face retrieval. In contrast to previous works which were
limited to low dimensional features and small datasets, the proposed method
scales to large datasets with high dimensional face descriptors. It utilises
pairwise (dis-)similarity constraints as supervision and hence does not require
exhaustive class annotation for every training image. While, traditionally,
multi-task learning methods have been validated on same dataset but different
tasks, we work on the more challenging setting with heterogeneous datasets and
different tasks. We show empirical validation on multiple face image datasets
of different facial traits, e.g. identity, age and expression. We use classic
Local Binary Pattern (LBP) descriptors along with the recent Deep Convolutional
Neural Network (CNN) features. The experiments clearly demonstrate the
scalability and improved performance of the proposed method on the tasks of
identity and age based face image retrieval compared to competitive existing
methods, on the standard datasets and with the presence of a million distractor
face images.


title:
Mode coupling of interaction quenched ultracold few-boson ensembles in
  periodically driven lattices

abstract:
  The out-of-equilibrium dynamics of interaction quenched finite ultracold
bosonic ensembles in periodically driven one-dimensional optical lattices is
investigated. It is shown that periodic driving enforces the bosons in the
outer wells of the finite lattice to exhibit out-of-phase dipole-like modes,
while in the central well the atomic cloud experiences a local breathing mode.
The dynamical behavior is investigated with varying driving frequency,
revealing a resonant-like behavior of the intra-well dynamics. An interaction
quench in the periodically driven lattice gives rise to admixtures of different
excitations in the outer wells, an enhanced breathing in the center and an
amplification of the tunneling dynamics. We observe then multiple resonances
between the inter- and intra-well dynamics at different quench amplitudes, with
the position of the resonances being tunable via the driving frequency. Our
results pave the way for future investigations on the use of combined driving
protocols in order to excite different inter- and intra-well modes and to
subsequently control them.


title:
Interplay between sign problem and Z_3 symmetry in three-dimensional
  Potts model

abstract:
  We construct four kinds of Z3-symmetric three-dimentional (3-d) Potts models,
each with different number of states at each site on a 3-d lattice, by
extending the 3-d three-state Potts model. Comparing the ordinary Potts model
with the four Z3-symmetric Potts models, we investigate how Z3 symmetry affects
the sign problem and see how the deconfinement transition line changes in the
$\mu-\kappa$ plane as the number of states increases, where $\mu$ $(\kappa)$
plays a role of chemical potential (temperature) in the models. We find that
the sign problem is almost cured by imposing Z3 symmetry. This mechanism may
happen in Z3-symmetric QCD-like theory. We also show that the deconfinement
transition line has stronger $\mu$-dependence with respect to increasing the
number of states.


title:
AC susceptibility as a tool to probe the dipolar interaction in magnetic
  nanoparticles

abstract:
  The dipolar interaction is known to substantially affect the properties of
magnetic nanoparticles. This is particularly important when the particles are
kept in a fluid suspension or packed inside nano-carriers. In addition to its
usual long-range nature, in these cases the dipolar interaction may also induce
the formation of clusters of particles, thereby strongly modifying their
magnetic anisotropies. In this paper we show how AC susceptibility may be used
to obtain important information regarding the influence of the dipolar
interaction in a sample. We develop a model which includes both aspects of the
dipolar interaction and may be fitted directly to the susceptibility data. The
usual long-range nature of the interaction is implemented using a mean-field
solution, whereas the particle-particle aggregation is modeled using a
distribution of anisotropy constants. The model is then applied to two samples
studied at different concentrations. One consists of spherical magnetite
nanoparticles dispersed in oil and the other of cubic magnetite nanoparticles
embedded on PLGA nanospheres. We also introduce a simple technique to access
the importance of the dipolar interaction in a given sample, based on the
height of the AC susceptibility peaks for different driving frequencies. Our
results help illustrate the important effect that the dipolar interaction has
in most nanoparticle samples.


title: Toward a Science of Autonomy for Physical Systems

abstract:
  Our lives have been immensely improved by decades of automation research --
we are more comfortable, more productive and safer than ever before. Just
imagine a world where familiar automation technologies have failed. In that
world, thermostats don't work -- you have to monitor your home heating system
manually. Cruise control for your car doesn't exist. Every elevator has to have
a human operator to hit the right floor, most manufactured products are
assembled by hand, and you have to wash your own dishes. Who would willingly
adopt that world -- the world of last century -- today? Physical systems --
elevators, cars, home appliances, manufacturing equipment -- were more
troublesome, ore time consuming, less safe, and far less convenient. Now,
suppose we put ourselves in the place someone 20 years in the future, a future
of autonomous systems. A future where transportation is largely autonomous,
more efficient, and far safer; a future where dangerous occupations like mining
or disaster response are performed by autonomous systems supervised remotely by
humans; a future where manufacturing and healthcare are twice as productive per
person-hour by having smart monitoring and readily re-tasked autonomous
physical agents; a future where the elderly and infirm have 24 hour in-home
autonomous support for the basic activities, both physical and social, of daily
life. In a future world where these capabilities are commonplace, why would
someone come back to today's world where someone has to put their life at risk
to do a menial job, we lose time to mindless activities that have no intrinsic
value, or be consumed with worry that a loved one is at risk in their own home?
In what follows, and in a series of associated essays, we expand on these
ideas, and frame both the opportunities and challenges posed by autonomous
physical systems.


title: Systems Computing Challenges in the Internet of Things

abstract:
  A recent McKinsey report estimates the economic impact of the Internet of
Things (IoT) to be between $3.9 to $11 trillion dollars by 20251 . IoT has the
potential to have a profound impact on our daily lives, including technologies
for the home, for health, for transportation, and for managing our natural
resources. The Internet was largely driven by information and ideas generated
by people, but advances in sensing and hardware have enabled computers to more
easily observe the physical world. Coupling this additional layer of
information with advances in machine learning brings dramatic new capabilities
including the ability to capture and process tremendous amounts of data; to
predict behaviors, activities, and the future in uncanny ways; and to
manipulate the physical world in response. This trend will fundamentally change
how people interact with physical objects and the environment. Success in
developing value-added capabilities around IoT requires a broad approach that
includes expertise in sensing and hardware, machine learning, networked
systems, human-computer interaction, security, and privacy. Strategies for
making IoT practical and spurring its ultimate adoption also require a
multifaceted approach that often transcends technology, such as with concerns
over data security, privacy, public policy, and regulatory issues. In this
paper we argue that existing best practices in building robust and secure
systems are insufficient to address the new challenges that IoT systems will
present. We provide recommendations regarding investments in research areas
that will help address inadequacies in existing systems, practices, tools, and
policies.


title:
Study of the process $e^+ e^- \to K^0_{S}K^0_{L}$ in the center-of-mass
  energy range 1004--1060 MeV with the CMD-3 detector at the VEPP-2000 $e^+
  e^-$ collider

abstract:
  The $e^+ e^- \to K^0_{S}K^0_{L}$ cross section has been measured in the
center-of-mass energy range 1004--1060 MeV at 25 energy points using $6.1
\times 10^5$ events with $K^0_{S}\to \pi^+\pi^-$ decay. The analysis is based
on 5.9 pb$^{-1}$ of an integrated luminosity collected with the CMD-3 detector
at the VEPP-2000 $e^+ e^-$ collider. To obtain $\phi(1020)$ meson parameters
the measured cross section is approximated according to the Vector Meson
Dominance model as a sum of the $\rho, \omega, \phi$-like amplitudes and their
excitations. This is the most precise measurement of the $e^+ e^- \to
K^0_{S}K^0_{L}$ cross section with a 1.8\% systematic uncertainty.


title:
Permanent matching of coupled optical bottle resonators with better than
  0.16 GHz precision

abstract:
  The fabrication precision is one of the most critical challenges on the way
to the creation of practical photonic circuits composed of coupled high
Q-factor microresonators. While very accurate transient tuning of
microresonators based on local heating has been reported, the record precision
of permanent resonance positioning achieved by post-processing is still within
1-5 GHz. Here we demonstrate two coupled bottle microresonators fabricated at
the fiber surface which resonances are matched with a better than 0.16 GHz
precision. This corresponds to a better than 0.17 angstrom precision in the
effective fiber radius variation. The achieved fabrication precision is only
limited by the resolution of our optical spectrum analyzer and can be
potentially improved by an order of magnitude.


title: Quasi-local energy with respect to a static spacetime

abstract:
  This article considers the quasi-local energy in reference to a general
static spacetime. We follow the approach developed by the authors in [19, 20,
7, 9] and define the quasi-local energy as a difference of surface
Hamiltonians, which are derived from the Einstein-Hilbert action. The new
quasi-local energy provides an effective gauge independent measurement of how
far a spacetime deviates away from the reference static spacetime on a finitely
extended region.


title: An explicit description of the radiation field in 3+1-dimensions

abstract:
  In previous work with A. Vasy and J. Wunsch, the author established an
asymptotic expansion for the radiation field on asymptotically Minkowski
spacetimes and showed that the exponents seen in the expansion are given by the
poles of a meromorphic family of operators on the spacetime's "boundary at
infinity". This note provides an explicit accounting of these poles when the
spacetime is 3+1-dimensional Minkowski space. We conclude by stating the
"resonant states" for the first few resonances and then posing a combinatorial
problem.


title:
Indium segregation during III-V quantum wire and quantum dot formation
  on patterned substrates

abstract:
  We report a model for metalorganic vapor-phase epitaxy on non-planar
substrates, specifically V-grooves and pyramidal recesses, which we apply to
the growth of InGaAs nanostructures. This model, based on a set of coupled
reaction-diffusion equations, one for each facet in the system, accounts for
the facet-dependence of all kinetic processes (e.g., precursor decomposition,
adatom diffusion, and adatom lifetimes) and has been previously applied to
account for the temperature, concentration, and temporal-dependence of AlGaAs
nanostructures on GaAs (111)B surfaces with V-grooves and pyramidal recesses.
In the present study, the growth of In$_{0.12}$Ga$_{0.88}$As quantum wires at
the bottom of V-grooves is used to determine a set of optimized kinetic
parameters. Based on these parameters, we have modeled the growth of
In$_{0.25}$Ga$_{0.75}$As nanostructures formed in pyramidal site-controlled
quantum-dot systems, successfully producing a qualitative explanation for the
temperature-dependence of their optical properties, which have been reported in
previous studies. Finally, we present scanning electron and cross-sectional
atomic force microscopy images which show previously unreported facetting at
the bottom of the pyramidal recesses that allow quantum dot formation.


title: Stronger wireless signals appear more Poisson

abstract:
  Keeler, Ross and Xia (2016) recently derived approximation and convergence
results, which imply that the point process formed from the signal strengths
received by an observer in a wireless network under a general statistical
propagation model can be modelled by an inhomogeneous Poisson point process on
the positive real line. The basic requirement for the results to apply is that
there must be a large number of transmitters with different locations and
random propagation effects.The aim of this note is to apply some of the main
results of Keeler, Ross and Xia (2016) in a less general but more easily
applicable form to illustrate how the results can be applied in practice. New
results are derived that show that it is the strongest signals, after being
weakened by random propagation effects, that behave like a Poisson process,
which supports recent experimental work.


title:
Swing Amplification of Galactic Spiral Arms: Phase Synchronization of
  Stellar Epicycle Motion

abstract:
  We revisit the swing amplification model of galactic spiral arms proposed by
Toomre (1981). We describe the derivation of the perturbation equation in
detail and investigate the amplification process of stellar spirals. We find
that the elementary process of the swing amplification is the phase
synchronization of the stellar epicycle motion. Regardless of the initial
epicycle phase, the epicycle phases of stars in a spiral are synchronized
during the amplification. Based on the phase synchronization, we explain the
dependence of the pitch angle of spirals on the epicycle frequency. We find the
most amplified spiral mode and calculate its pitch angle, wavelengths, and
amplification factor, which are consistent with those obtained by the more
rigorous model based on the Boltzmann equation by Julian and Toomre (1966).


title:
$N^*$ Resonances in Lattice QCD from (mostly) Low to (sometimes) High
  Virtualities

abstract:
  I present a survey of calculations of the excited $N^*$ spectrum in lattice
QCD. I then describe recent advances aimed at extracting the momentum-dependent
phase shifts from lattice calculations, notably in the meson sector, and the
potential for their application to baryons. I conclude with a discussion of
calculations of the electromagnetic transition form factors to excited
nucleons, including calculations at high $Q^2$.


title: Collective modes in multi-Weyl semimetals

abstract:
  We investigate collective modes in three dimensional (3D) gapless multi-Weyl
semimetals with anisotropic energy band dispersions (i.e., $E\sim \sqrt{
k_{\parallel}^{2J} + k_z^2}$, where $k_{\parallel}$ and $k_z$ are wave vectors
and $J$ is a positive integer). For comparison, we also consider the gapless
semimetals with the isotropic band dispersions (i.e., $E\sim k^J$). We
calculate analytically long-wavelength plasma frequencies incorporating
interband transitions and chiral properties of carriers. For both the isotropic
and anisotropic cases, we find that interband transitions and chirality lead to
the depolarization shift of plasma frequencies. For the isotropic parabolic
band dispersion (i.e., $N=2$, $E\sim k^2$), the long-wavelength plasma
frequencies lie outside the single particle excitation regions for all carrier
densities, and thus the plasmons do not decay via Landau damping. For the
higher-order band dispersions ($N \ge 3$) the long-wavelength plasmons
experience damping below a critical density. For systems with the anisotropic
dispersion the density dependence of the long-wavelength plasma frequency along
the direction of non-linear dispersion behaves like that of the isotropic
linear band model ($N=1$), while along the direction of linear dispersion it
behaves like that of the isotropic non-linear model ($N \ge 2$). Plasmons along
both directions remain undamped over a broad range of densities due to the
chirality induced depolarization shift. Our results provide a comprehensive
picture of how band dispersion and chirality affect plasmon behaviors in 3D
gapless chiral systems with the arbitrary band dispersion.


title: Vacuum Incalescence

abstract:
  In quantum theory the vacuum is defined as a state of minimum energy that is
devoid of particles but still not completely empty. It is perhaps more
surprising that its definition depends on the geometry of the system and on the
trajectory of an observer through space-time. Along these lines we investigate
the case of an atom flying at constant velocity near a planar surface. Using
general concepts of statistical mechanics it is shown that the motion-modified
interaction with the electromagnetic vacuum is formally equivalent to the
interaction with a thermal field having an effective temperature determined by
the atom's velocity and distance from the surface. This result suggests new
ways to experimentally investigate the properties of the quantum vacuum in
non-equilibrium systems and effects such as quantum friction.


title: Diffusion and transport in locally disordered driven lattices

abstract:
  We study the effect of disorder on the particle density evolution in a
classical Hamiltonian driven lattice setup. If the disorder is localized within
a finite sub-domain of the lattice, the emergence of strong tails in the
density distribution which even increases towards larger positions is shown,
thus yielding a highly non Gaussian particle density evolution. As the key
underlying mechanism we identify the conversion between different components of
the unperturbed systems mixed phase space which is induced by the disorder.
Based on the introduction of individual conversion rates between chaotic and
regular components, a theoretical model is developed which correctly predicts
the scaling of the particle density. The effect of disorder on the transport
properties is studied where a significant enhancement of the transport for
cases of localized disorder is shown, thereby contrasting strongly the merely
weak modification of transport for global disorder.


title: Algorithmic quantum simulation of memory effects

abstract:
  We propose a method for the algorithmic quantum simulation of memory effects
described by integrodifferential evolution equations. It consists in the
systematic use of perturbation theory techniques and a Markovian quantum
simulator. Our method aims to efficiently simulate both completely positive and
nonpositive dynamics without the requirement of engineering non-Markovian
environments. Finally, we find that small error bounds can be reached with
polynomially scaling resources, evaluated as the time required for the
simulation.


title: Using Sentence-Level LSTM Language Models for Script Inference

abstract:
  There is a small but growing body of research on statistical scripts, models
of event sequences that allow probabilistic inference of implicit events from
documents. These systems operate on structured verb-argument events produced by
an NLP pipeline. We compare these systems with recent Recurrent Neural Net
models that directly operate on raw tokens to predict sentences, finding the
latter to be roughly comparable to the former in terms of predicting missing
events in documents.


title: Convergence to a single wave in the Fisher-KPP equation

abstract:
  We study the large time asymptotics of a solution of the Fisher-KPP
reaction-diffusion equation, with an initial condition that is a compact
perturbation of a step function. A well-known result of Bramson states that, in
the reference frame moving as $2t - ({3}/{2}) \log t +x_\infty$, the solution
of the equation converges as $t\to+\infty$ to a translate of the traveling wave
corresponding to the minimal speed~$c_*=2$. The constant $x_\infty$ depends on
the initial condition $u(0,x)$. The proof is elaborate, and based on
probabilistic arguments. The purpose of this paper is to provide a simple proof
based on PDE arguments.


title: Modular invariant inflation

abstract:
  Modular invariance is a striking symmetry in string theory, which may keep
stringy corrections under control. In this paper, we investigate a
phenomenological consequence of the modular invariance, assuming that this
symmetry is preserved as well as in a four dimensional (4D) low energy
effective field theory. As a concrete setup, we consider a modulus field $T$
whose contribution in the 4D effective field theory remains invariant under the
modular transformation and study inflation drived by $T$. The modular
invariance restricts a possible form of the scalar potenntial. As a result,
large field models of inflation are hardly realized. Meanwhile, a small field
model of inflation can be still accomodated in this restricted setup. The
scalar potential traced during the slow-roll inflation mimics the hilltop
potential $V_{ht}$, but it also has a non-negligible deviation from $V_{ht}$.
Detecting the primordial gravitational waves predicted in this model is rather
challenging. Yet, we argue that it may be still possible to falsify this model
by combining the information in the reheating process which can be determined
self-completely in this setup.


title: Generalized Second Law of Thermodynamic in Modified Teleparallel Theory

abstract:
  This study is conducted to examine the validity of generalized second law of
thermodynamics (GSLT) in flat FRW for modified teleparallel gravity involving
coupling between a scalar field with the torsion scalar $T$ and the boundary
term $B=2\nabla_{\mu}T^{\mu}$. This theory is very useful since it can
reproduce other important well-known scalar field theories in suitable limits.
The validity of the first and second law of thermodynamics at the apparent
horizon is discussed for any coupling. As examples, we have also explored the
validity of those thermodynamics laws in some new cosmological solutions under
the theory. Additionally, we have also considered the logarithmic entropy
corrected relation and discuss the GSLT at the apparent horizon.


title:
Measurement of fiducial differential cross sections of gluon-fusion
  production of Higgs bosons decaying to $WW^{\ast}{\rightarrow\,}e\nu\mu\nu$
  with the ATLAS detector at $\sqrt{s}=8$ TeV

abstract:
  This paper describes a measurement of fiducial and differential cross
sections of gluon-fusion Higgs boson production in the
$H{\rightarrow\,}WW^{\ast}{\rightarrow\,}e\nu\mu\nu$ channel, using 20.3
fb$^{-1}$ of proton-proton collision data. The data were produced at a
centre-of-mass energy of $\sqrt{s} = 8$ TeV at the CERN Large Hadron Collider
and recorded by the ATLAS detector in 2012. Cross sections are measured from
the observed $H{\rightarrow\,}WW^{\ast}{\rightarrow\,}e\nu\mu\nu$ signal yield
in categories distinguished by the number of associated jets. The total cross
section is measured in a fiducial region defined by the kinematic properties of
the charged leptons and neutrinos. Differential cross sections are reported as
a function of the number of jets, the Higgs boson transverse momentum, the
dilepton rapidity, and the transverse momentum of the leading jet. The jet-veto
efficiency, or fraction of events with no jets above a given transverse
momentum threshold, is also reported. All measurements are compared to QCD
predictions from Monte Carlo generators and fixed-order calculations, and are
in agreement with the Standard Model predictions.


title:
All-Optical Study of Tunable Ultrafast Spin Dynamics in [Co/Pd]-NiFe
  Systems: The Role of Spin-Twist Structure on Gilbert Damping

abstract:
  We investigate optically induced ultrafast magnetization dynamics in [Co(0.5
nm)/Pd(1 nm)]x5/NiFe(t) exchange-spring samples with tilted perpendicular
magnetic anisotropy using a time-resolved magneto-optical Kerr effect
magnetometer. The competition between the out-of-plane anisotropy of the hard
layer, the in-plane anisotropy of the soft layer and the applied bias field
reorganizes the spins in the soft layer, which are modified further with the
variation in t. The spin-wave spectrum, the ultrafast demagnetization time, and
the extracted damping coefficient all depend on the spin distribution in the
soft layer, while the latter two also depend on the spin-orbit coupling between
the Co and Pd layers. The spin-wave spectra change from multimode to
single-mode as t increases. At the maximum field reached in this study, H=2.5
kOe, the damping shows a nonmonotonic dependence on t with a minimum at t=7.5
nm. For t<7.5 nm, intrinsic effects dominate, whereas for t>7.5 nm, extrinsic
effects govern the damping mechanisms.


title: Energetic molding of chiral magnetic bubbles

abstract:
  Topologically protected magnetic structures such as skyrmions and domain
walls (DWs) have drawn a great deal of attention recently due to their thermal
stability and potential for manipulation by spin current, which is the result
of chiral magnetic configurations induced by the interfacial
Dzyaloshinskii-Moriya Interaction (DMI). Designing devices that incorporate DMI
necessitates a thorough understanding of how the interaction presents and can
be measured. One approach is to measure growth asymmetry of chiral bubble
domains in perpendicularly magnetized thin films, which has been described
elsewhere by thermally activated DW motion. Here, we demonstrate that the
anisotropic angular dependence of DW energy originating from the DMI is
critical to understanding this behavior. Domains in Co/Ni multi-layers are
observed to preferentially grow into non-elliptical teardrop shapes, which vary
with the magnitude of an applied in-plane field. We model the domain profile
using energetic calculations of equilibrium shape via the Wulff construction,
which explains both the teardrop shape and the reversal of growth symmetry at
large fields.


title: Exact Reconstruction from Insertions in Synchronization Codes

abstract:
  This work studies problems in data reconstruction, an important area with
numerous applications. In particular, we examine the reconstruction of binary
and non-binary sequences from synchronization (insertion/deletion-correcting)
codes. These sequences have been corrupted by a fixed number of symbol
insertions (larger than the minimum edit distance of the code), yielding a
number of distinct traces to be used for reconstruction. We wish to know the
minimum number of traces needed for exact reconstruction. This is a general
version of a problem tackled by Levenshtein for uncoded sequences.
  We introduce an exact formula for the maximum number of common supersequences
shared by sequences at a certain edit distance, yielding an upper bound on the
number of distinct traces necessary to guarantee exact reconstruction. Without
specific knowledge of the codewords, this upper bound is tight. We apply our
results to the famous single deletion/insertion-correcting Varshamov-Tenengolts
(VT) codes and show that a significant number of VT codeword pairs achieve the
worst-case number of outputs needed for exact reconstruction. We also consider
extensions to other channels, such as adversarial deletion and
insertion/deletion channels and probabilistic channels.


title:
Inherit Differential Privacy in Distributed Setting: Multiparty
  Randomized Function Computation

abstract:
  How to achieve differential privacy in the distributed setting, where the
dataset is distributed among the distrustful parties, is an important problem.
We consider in what condition can a protocol inherit the differential privacy
property of a function it computes. The heart of the problem is the secure
multiparty computation of randomized function. A notion \emph{obliviousness} is
introduced, which captures the key security problems when computing a
randomized function from a deterministic one in the distributed setting. By
this observation, a sufficient and necessary condition about computing a
randomized function from a deterministic one is given. The above result can not
only be used to determine whether a protocol computing differentially private
function is secure, but also be used to construct secure one. Then we prove
that the differential privacy property of a function can be inherited by the
protocol computing it if the protocol privately computes it. A composition
theorem of differentially private protocols is also presented. We also
construct some protocols to generate random variate in the distributed setting,
such as the uniform random variates and the inversion method. By using these
fundamental protocols, we construct protocols of the Gaussian mechanism, the
Laplace mechanism and the Exponential mechanism. Importantly, all these
protocols satisfy obliviousness and so can be proved to be secure in a
simulation based manner. We also provide a complexity bound of computing
randomized function in the distribute setting. Finally, to show that our
results are fundamental and powerful to multiparty differential privacy, we
construct a differentially private empirical risk minimization protocol.


title: An asymptotic multipartite K\"uhn-Osthus theorem

abstract:
  In this paper we prove an asymptotic multipartite version of a well-known
theorem of K\"uhn and Osthus by establishing, for any graph $H$ with chromatic
number $r$, the asymptotic multipartite minimum degree threshold which ensures
that a large $r$-partite graph $G$ admits a perfect $H$-tiling. We also give
the threshold for an $H$-tiling covering all but a linear number of vertices of
$G$, in a multipartite analogue of results of Koml\'os and of Shokoufandeh and
Zhao.


title:
Global stabilization of linear systems with bounds on the feedback and
  its successive derivatives

abstract:
  We address the global stabilization of linear time-invariant (LTI) systems
when the magnitude of the control input and its successive time derivatives, up
to an order $p\in\mathbb N$, are bounded by prescribed values. We propose a
static state feedback that solves this problem for any admissible LTI systems,
namely for stabilizable systems whose internal dynamics has no eigenvalue with
positive real part. This generalizes previous work done for single-input chains
of integrators and rotating dynamics.


title: Aliquot sequences with small starting values

abstract:
  We describe the results of the computation of aliquot sequences with small
starting values. In particular all sequences with starting values less than a
million have been computed until either termination occurred (at 1 or a cycle),
or an entry of 100 decimal digits was encountered. All dependencies were
recorded, and numerous statistics, curiosities, and records are reported.


title:
Direct single-shot observation of millimeter wave superradiance in
  Rydberg-Rydberg transitions

abstract:
  We have directly detected millimeter wave (mm-wave) free space superradiant
emission from Rydberg states ($n \sim 30$) of barium atoms in a single shot. We
trigger the cooperative effects with a weak initial pulse and detect with
single-shot sensitivity and 20 ps time resolution, which allows measurement and
shot-by-shot analysis of the distribution of decay rates, time delays, and
time-dependent frequency shifts. Cooperative line shifts and decay rates are
observed that exceed values that would correspond to the Doppler width of 250
kHz by a factor of 20 and the spontaneous emission rate of 50 Hz by a factor of
$10^5$. The initial superradiant output pulse is followed by evolution of the
radiation-coupled many-body system toward complex long-lasting emission modes.
A comparison to a mean-field theory is presented which reproduces the
quantitative time-domain results, but fails to account for either the
frequency-domain observations or the long-lived features.


title: Demystifying Fixed k-Nearest Neighbor Information Estimators

abstract:
  Estimating mutual information from i.i.d. samples drawn from an unknown joint
density function is a basic statistical problem of broad interest with
multitudinous applications. The most popular estimator is one proposed by
Kraskov and St\"ogbauer and Grassberger (KSG) in 2004, and is nonparametric and
based on the distances of each sample to its $k^{\rm th}$ nearest neighboring
sample, where $k$ is a fixed small integer. Despite its widespread use (part of
scientific software packages), theoretical properties of this estimator have
been largely unexplored. In this paper we demonstrate that the estimator is
consistent and also identify an upper bound on the rate of convergence of the
bias as a function of number of samples. We argue that the superior performance
benefits of the KSG estimator stems from a curious "correlation boosting"
effect and build on this intuition to modify the KSG estimator in novel ways to
construct a superior estimator. As a byproduct of our investigations, we obtain
nearly tight rates of convergence of the $\ell_2$ error of the well known fixed
$k$ nearest neighbor estimator of differential entropy by Kozachenko and
Leonenko.


title:
Keplerian integrals, elimination theory and identification of very short
  arcs in a large database of optical observations

abstract:
  The modern optical telescopes produce a huge number of asteroid observations,
that are grouped into very short arcs (VSAs), each containing a few
observations of the same object in one single night. To decide whether two
VSAs, collected in different nights, refer to the same observed object we can
attempt to compute an orbit with the observations of both arcs: this is called
the linkage problem. Since the number of orbit computations to be performed is
very large, we need efficient methods of orbit determination. Using the first
integrals of Kepler's motion we can write algebraic equations for the linkage
problem, which can be put in polynomial form. The equations introduced in
(Gronchi et al. 2015) can be reduced to a univariate polynomial of degree 9:
the unknown is the topocentric distance $\rho$ of the observed body at the mean
epoch of one of the VSAs. Using elimination theory we show an optimal property
of this polynomial: it has the least degree among the univariate polynomials in
the same variable that are consequence of the algebraic conservation laws and
are obtained without squaring operations, that can be used to bring these
algebraic equations in polynomial form. In this paper we also introduce a
procedure to join three VSAs belonging to different nights: from the
conservation of angular momentum at the three mean epochs of the VSAs, we
obtain a univariate polynomial equation of degree 8 in the topocentric distance
$\rho_2$ at the intermediate epoch. This algorithm has the same computational
complexity as the classical method by Gauss, but uses more information,
therefore we expect that it can produce more accurate results. For both
methods, linking two and three VSAs, we also discuss how to select the
solutions, making use of the full two-body dynamics, and show some numerical
tests comparing the results with the ones obtained by Gauss' method.


title:
Efficient FPT algorithms for (strict) compatibility of unrooted
  phylogenetic trees

abstract:
  In phylogenetics, a central problem is to infer the evolutionary
relationships between a set of species $X$; these relationships are often
depicted via a phylogenetic tree -- a tree having its leaves univocally labeled
by elements of $X$ and without degree-2 nodes -- called the "species tree". One
common approach for reconstructing a species tree consists in first
constructing several phylogenetic trees from primary data (e.g. DNA sequences
originating from some species in $X$), and then constructing a single
phylogenetic tree maximizing the "concordance" with the input trees. The
so-obtained tree is our estimation of the species tree and, when the input
trees are defined on overlapping -- but not identical -- sets of labels, is
called "supertree". In this paper, we focus on two problems that are central
when combining phylogenetic trees into a supertree: the compatibility and the
strict compatibility problems for unrooted phylogenetic trees. These problems
are strongly related, respectively, to the notions of "containing as a minor"
and "containing as a topological minor" in the graph community. Both problems
are known to be fixed-parameter tractable in the number of input trees $k$, by
using their expressibility in Monadic Second Order Logic and a reduction to
graphs of bounded treewidth. Motivated by the fact that the dependency on $k$
of these algorithms is prohibitively large, we give the first explicit dynamic
programming algorithms for solving these problems, both running in time
$2^{O(k^2)} \cdot n$, where $n$ is the total size of the input.


title: Know When to Persist: Deriving Value from a Stream Buffer

abstract:
  We consider \textsc{Persistence}, a new online problem concerning optimizing
weighted observations in a stream of data when the observer has limited buffer
capacity. A stream of weighted items arrive one at a time at the entrance of a
buffer with two holding locations. A processor (or observer) can process
(observe) an item at the buffer location it chooses, deriving this way the
weight of the observed item as profit. The main constraint is that the
processor can only move {\em synchronously} with the item stream; as a result,
moving from the end of the buffer to the entrance, it crosses paths with the
item already there, and will never have the chance to process or even identify
it. \textsc{Persistence}\ is the online problem of scheduling the processor
movements through the buffer so that its total derived value is maximized under
this constraint.
  We study the performance of the straight-forward heuristic {\em Threshold},
i.e., forcing the processor to "follow" an item through the whole buffer only
if its value is above a threshold. We analyze both the optimal offline and
Threshold algorithms in case the input stream is a random permutation, or its
items are iid valued. We show that in both cases the competitive ratio achieved
by the Threshold algorithm is at least $2/3$ when the only statistical
knowledge of the items is the median of all possible values. We generalize our
results by showing that Threshold, equipped with some minimal statistical
advice about the input, achieves competitive ratios in the whole spectrum
between $2/3$ and $1$, following the variation of a newly defined density-like
measure of the input. This result is a significant improvement over the case of
arbitrary input streams, since in this case we show that no online algorithm
can achieve a competitive ratio better than $1/2$.


title: Semi-supervised learning of local structured output predictors

abstract:
  In this paper, we study the problem of semi-supervised structured output
prediction, which aims to learn predictors for structured outputs, such as
sequences, tree nodes, vectors, etc., from a set of data points of both
input-output pairs and single inputs without outputs. The traditional methods
to solve this problem usually learns one single predictor for all the data
points, and ignores the variety of the different data points. Different parts
of the data set may have different local distributions, and requires different
optimal local predictors. To overcome this disadvantage of existing methods, we
propose to learn different local predictors for neighborhoods of different data
points, and the missing structured outputs simultaneously. In the neighborhood
of each data point, we proposed to learn a linear predictor by minimizing both
the complexity of the predictor and the upper bound of the structured
prediction loss. The minimization is conducted by gradient descent algorithms.
Experiments over four benchmark data sets, including DDSM mammography medical
images, SUN natural image data set, Cora research paper data set, and Spanish
news wire article sentence data set, show the advantages of the proposed
method.


title:
A Statistical Analysis of Solar Surface Indices Through the Solar
  Activity Cycles 21-23

abstract:
  Variations of total solar irradiance (TSI), magnetic field, Ca II K-flux,
faculae and plage areas due to the number and the type of sunspots/sunspot
groups (SGs) are well established by using Solar Irradiance Platform and ground
based data from various centers such as Stanford Data (SFO), Kodaikanal data
(KKL) and National Geographical Data Center (NGDC) Homepage, respectively. We
applied time series analysis for extracting the data over the descending phases
of solar activity cycles (SACs) 21, 22 and 23, and the ascending phases 22 and
23 of SACs, and analyzed the selected data using the Python programming
language. Our detailed analysis results suggest that there is a stronger
correlation between solar surface indices and the changes in the relative
portion of the small and large SGs. This somewhat unexpected finding suggest
that plage regions decreased in a lower values in spite of the higher number of
large SGs in SAC 23 while Ca II K-flux did not decrease by large amount or it
was comparable with SAC 22 for some years and relates with C type and DEF type
SGs. Thus, increase of facular areas which are influenced by large SGs caused a
small percentage decrease in TSI while decrement of plage areas triggered a
higher decrease in the flux of magnetic field. Our results thus reveal the
potential of such detailed comparison of SG analysis with solar surface indices
for understanding and predicting future trends in the SAC.


title: Theory of microphase separation in bidisperse chiral membranes

abstract:
  We present a Ginzburg-Landau theory of micro phase separation in a bidisperse
chiral membrane consisting of rods of opposite handendness. This model system
undergoes a phase transition from an equilibrium state where the two components
are completely phase separated to a microphase separated state composed of
domains of a finite size comparable to the twist penetration depth.
Characterizing the phenomenology using linear stability analysis and numerical
studies, we trace the origin of the discontinuous change in domain size that
occurs during this to a competition between the cost of creating an interface
and the gain in twist energy for small domains in which the twist penetrates
deep into the center of the domain.


title:
Gravitational waves and magnetic monopoles during inflation with
  Weitzenb\"ock torsion

abstract:
  We study the variational principle on a Hilbert-Einstein action in an
extended geometry with torsion taking into account non-trivial boundary
conditions. We obtain an effective energy-momentum tensor that has its source
in the torsion, which represents the matter geometrically induced. We explore
about the existence of magnetic monopoles and gravitational waves in this
torsional geometry. We conclude that the boundary terms can be identified as
possible sources for the cosmological constant and torsion as the source of
magnetic monopoles. We examine an example in which gravitational waves are
produced during a de Sitter inflationary expansion of the universe.


title:
Distributed Nonlinear Observer with Robust Performance - A Circle
  Criterion Approach

abstract:
  In this paper, we present a distributed version of the KYP-Lemma with the
goal to express the strictly positive real-property for a class of physically
interconnected systems by a set of local LMI-conditions. The resulting
conditions are subsequently used to constructively design distributed circle
criterion estimators, which are able to collectively estimate an underlying
linear system with a sector bounded nonlinearity.


title:
The Haight-Ruzsa method for sets with more differences than multiple
  sums

abstract:
  Let $h$ be a positive integer and let $\varepsilon > 0$. The Haight-Ruzsa
method produces a positive integer $m^*$ and a subset $A$ of the additive
abelian group $\mathbf{Z}/m^*\mathbf{Z}$ such that the difference set is large
in the sense that $A-A = \mathbf{Z}/m^*\mathbf{Z}$ and $h$-fold sumset is small
in the sense that $|hA| < \varepsilon m^*$. This note describes, and in a
modest way extends, the Haight-Ruzsa argument, and constructs sets with more
differences than multiple sums in other additive abelian groups.


title: Face monoid actions and tropical hyperplane arrangements

abstract:
  We study the combinatorics of tropical hyperplane arrangements, and their
relationship to (classical) hyperplane face monoids. We show that the
refinement operation on the faces of a tropical hyperplane arrangement,
introduced by Ardila and Develin in their definition of a tropical oriented
matroid, induces an action of the hyperplane face monoid of the classical braid
arrangement on the arrangement, and hence on a number of interesting related
structures. Along the way, we introduce a new characterization of the types (in
the sense of Develin and Sturmfels) of points with respect to a tropical
hyperplane arrangement, in terms of partial bijections which attain permanents
of submatrices of a matrix which naturally encodes the arrangement.


title: Heavy-quark mass effects in Higgs plus jets production

abstract:
  We study the production of a Standard Model Higgs boson in the gluon-fusion
channel at the 13 TeV LHC. Our results are accurate to the next-to-leading
order in QCD, bar for the lack of some two-loop amplitudes, for up to two extra
jets and are matched to the PYTHIA8 Monte Carlo. We address the impact, at the
level of inclusive rates and of differential distributions, of the merging of
samples characterised by different final-state multiplicities, and of the
effects induced by top and bottom masses through heavy-quark loop diagrams. We
find that both the merging and the heavy-quark masses must be included in the
calculation in order to realistically predict observables of experimental
interest.


title:
Statistical Properties of Quasi-Periodic Pulsations in White-Light
  Flares Observed With Kepler

abstract:
  We embark on a study of quasi-periodic pulsations (QPPs) in the decay phase
of white-light stellar flares observed by Kepler. Out of the 1439 flares on 216
different stars detected in the short-cadence data using an automated search,
56 flares are found to have pronounced QPP-like signatures in the light curve,
of which 11 have stable decaying oscillations. No correlation is found between
the QPP period and the stellar temperature, radius, rotation period and surface
gravity, suggesting that the QPPs are independent of global stellar parameters.
Hence they are likely to be the result of processes occurring in the local
environment. There is also no significant correlation between the QPP period
and flare energy, however there is evidence that the period scales with the QPP
decay time for the Gaussian damping scenario, but not to a significant degree
for the exponentially damped case. This same scaling has been observed for MHD
oscillations on the Sun, suggesting that they could be the cause of the QPPs in
those flares. Scaling laws of the flare energy are also investigated,
supporting previous reports of a strong correlation between the flare energy
and stellar temperature/radius. A negative correlation between the flare energy
and stellar surface gravity is also found.


title:
EEG in the classroom: Synchronised neural recordings during video
  presentation

abstract:
  We performed simultaneous recordings of electroencephalography (EEG) from
multiple students in a classroom, and measured the inter-subject correlation
(ISC) of activity evoked by a common video stimulus. The neural reliability, as
quantified by ISC, has been linked to engagement and attentional modulation in
earlier studies that used high-grade equipment in laboratory settings. Here we
reproduce many of the results from these studies using portable low-cost
equipment, focusing on the robustness of using ISC for subjects experiencing
naturalistic stimuli. The present data shows that stimulus-evoked neural
responses, known to be modulated by attention, can be tracked in for groups of
students with synchronized EEG acquisition. This is a step towards real-time
inference of engagement in the classroom.


title: Linearly Typed Dyadic Group Sessions for Building Multiparty Sessions

abstract:
  Traditionally, each party in a (dyadic or multiparty) session implements
exactly one role specified in the type of the session. We refer to this kind of
session as an individual session (i-session). As a generalization of i-session,
a group session (g-session) is one in which each party may implement a group of
roles based on one channel. In particular, each of the two parties involved in
a dyadic g-session implements either a group of roles or its complement. In
this paper, we present a formalization of g-sessions in a multi-threaded
lambda-calculus (MTLC) equipped with a linear type system, establishing for the
MTLC both type preservation and global progress. As this formulated MTLC can be
readily embedded into ATS, a full-fledged language with a functional
programming core that supports both dependent types (of DML-style) and linear
types, we obtain a direct implementation of linearly typed g-sessions in ATS.
The primary contribution of the paper lies in both of the identification of
g-sessions as a fundamental building block for multiparty sessions and the
theoretical development in support of this identification.


title: Tautochrone and Brachistochrone Shape Solutions for Rocking Rigid Bodies

abstract:
  Rocking rigid bodies appear in several shapes in everyday life: As furniture
like rocking chairs and rocking cradles or as toys like rocking horses or
tilting dolls. The familiar rocking motion of these objects, a non-linear
combination of a rigid rotation and a translation of the center of mass, gives
rise to a number of interesting dynamical properties. However, their study has
received little attention in the literature.
  This work presents a comprehensive introduction to the dynamics of rocking
rigid bodies, including a concise derivation of the equations of motion as well
as a general inversion procedure to construct rocking rigid body shapes with
specified dynamical properties. Moreover, two novel rigid body shapes are
derived - the tautochrone shape and the brachistochrone shape - which represent
an intriguing generalization of the well-know tautochrone and brachistochrone
curves. In particular, tautochrone shapes offer an alternative construction of
a tautochrone pendulum, in addition to Huygens' cycloid pendulum solution.


title: Asymptotic theory of path spaces of graded graphs and its applications

abstract:
  The survey covers several topics related to the asymptotic structure of
various combinatorial and analytic objects such as the path spaces in graded
graphs (Bratteli diagrams), invariant measures with respect to countable
groups, etc. The main subject is the asymptotic structure of filtrations and a
new notion of standardness. All graded graphs and all filtrations of Borel or
measure spaces can be divided into two classes: the standard ones, which have a
regular behavior at infinity, and the other ones. Depending on this property,
the list of invariant measures can either be well parameterized or have no good
parametrization at all. One of the main results is a general standardness
criterion for filtrations. We consider some old and new examples which
illustrate the usefulness of this point of view and the breadth of its
applications.


title: Multivariate Trace Inequalities

abstract:
  We prove several trace inequalities that extend the Golden-Thompson and the
Araki-Lieb-Thirring inequality to arbitrarily many matrices. In particular, we
strengthen Lieb's triple matrix inequality. As an example application of our
four matrix extension of the Golden-Thompson inequality, we prove remainder
terms for the monotonicity of the quantum relative entropy and strong
sub-additivity of the von Neumann entropy in terms of recoverability. We find
the first explicit remainder terms that are tight in the commutative case. Our
proofs rely on complex interpolation theory as well as asymptotic spectral
pinching, providing a transparent approach to treat generic multivariate trace
inequalities.


title:
Spectral stability for classical periodic waves of the Ostrovsky and
  short pulse models

abstract:
  We consider the Ostrovsky and short pulse models in a symmetric spatial
interval, subject to periodic boundary conditions. For the Ostrovsky case, we
revisit the classical periodic traveling waves and for the short pulse model,
we explicitly construct traveling waves in terms of Jacobi elliptic functions.
For both examples, we show spectral stability, for all values of the
parameters. This is achieved by studying the non-standard eigenvalue problems
in the form $L u=\la u'$, where $L$ is a Hill operator.


title:
Associated production of electroweak bosons and heavy mesons at LHCb and
  prospects to observe double parton interactions

abstract:
  The production of weak gauge bosons in association with heavy flavored mesons
at the LHCb conditions is considered, and a detailed study of the different
contributing processes is presented including single (SPS) and double (DPS)
parton scattering mechanisms. We find that the usual DPS factorization formula
needs to be corrected for the limited partonic phase space, and that including
the relevant corrections reduces discrepancies in the associated $ZD$
production. We conclude finally that double parton scattering dominates the
production of same-sign $W^\pm D^\pm$ states, as well as the production of
$W^-$ bosons associated with $B$-mesons. The latter processes can thus be
regarded as new useful DPS indicators.


title:
A Search for short-period Rocky Planets around WDs with the Cosmic
  Origins Spectrograph (COS)

abstract:
  The search for transiting habitable exoplanets has broadened to include
several types of stars that are smaller than the Sun in an attempt to increase
the observed transit depth and hence the atmospheric signal of the planet. Of
all spectral types, white dwarfs are the most favorable for this type of
investigation. The fraction of white dwarfs that possess close-in rocky planets
is unknown, but several large angle stellar surveys have the photometric
precision and cadence to discover at least one if they are common. Ultraviolet
observations of white dwarfs may allow for detection of molecular oxygen or
ozone in the atmosphere of a terrestrial planet. We use archival Hubble Space
Telescope data from the Cosmic Origins Spectrograph to search for transiting
rocky planets around UV-bright white dwarfs. In the process, we discovered
unusual variability in the pulsating white dwarf GD 133, which shows slow
sinusoidal variations in the UV. While we detect no planets around our small
sample of targets, we do place stringent limits on the possibility of
transiting planets, down to sub-lunar radii. We also point out that
non-transiting small planets in thermal equilibrium are detectable around
hotter white dwarfs through infrared excesses, and identify two candidates.


title: Comparative analysis of finite field-dependent BRST transformations

abstract:
  We present a review of our recent study (A. Reshetnyak, IJMPA 29 (2014)
1450128; P. Moshin, A. Reshetnyak, Nucl. Phys. B 888 (2014) 92; Phys. Lett B
739 (2014) 110; IJMPA 29 (2014) 1450159; IJMPA 30 (2015) 1550021; IJMPA 31
(2016) 1650111), in which the concept of finite field-dependent BRST and
BRST-antiBRST transformations for gauge theories was introduced, and their
properties investigated. An algorithm of exact calculation for the Jacobian of
a respective change of variables in the path integral is presented.
Applications to the Yang--Mills theory and Standard Model, in view of infra-red
(Gribov) peculiarities, are discussed.


title:
Superconducting phase diagrams of cuprates and pnictides as a key to the
  HTSC mechanism

abstract:
  This paper reviews experimental phase diagrams of cuprates and pnictides to
demonstrate that specific features of the superconducting phase diagrams in
bothHTSC families can be understood within the framework of the proposed
approach,which assumes the formation, under heterovalent doping, of localized
trion complexes consisting of a doped carrier and charge transfer (CT)
excitons. The geometry of such cells containing CT excitons (CT plaquettes) in
the basal plane of the crystal is determined by its crystal structure and the
type of dopant, so that the dopant concentration range corresponding to the
existence of a percolation cluster of CT plaquettes can be readily determined
for each particular compound. These dopant concentration ranges coincide with
good accuracy with the experimental ranges of superconducting domes in the
phase diagrams of the HTSC compounds considered. The generation of free
carriers and the mechanism of superconducting pairing in this pattern is
related to biexciton complexes (Heitler-London centers) emerging in neighboring
CT plaquettes.


title:
Mapping Out Narrative Structures and Dynamics Using Networks and Textual
  Information

abstract:
  Human communication is often executed in the form of a narrative, an account
of connected events composed of characters, actions, and settings. A coherent
narrative structure is therefore a requisite for a well-formulated narrative --
be it fictional or nonfictional -- for informative and effective communication,
opening up the possibility of a deeper understanding of a narrative by studying
its structural properties. In this paper we present a network-based framework
for modeling and analyzing the structure of a narrative, which is further
expanded by incorporating methods from computational linguistics to utilize the
narrative text. Modeling a narrative as a dynamically unfolding system, we
characterize its progression via the growth patterns of the character network,
and use sentiment analysis and topic modeling to represent the actual content
of the narrative in the form of interaction maps between characters with
associated sentiment values and keywords. This is a network framework advanced
beyond the simple occurrence-based one most often used until now, allowing one
to utilize the unique characteristics of a given narrative to a high degree.
Given the ubiquity and importance of narratives, such advanced network-based
representation and analysis framework may lead to a more systematic modeling
and understanding of narratives for social interactions, expression of human
sentiments, and communication.


title: Amortized Dynamic Cell-Probe Lower Bounds from Four-Party Communication

abstract:
  This paper develops a new technique for proving amortized, randomized
cell-probe lower bounds on dynamic data structure problems. We introduce a new
randomized nondeterministic four-party communication model that enables
"accelerated", error-preserving simulations of dynamic data structures.
  We use this technique to prove an $\Omega(n(\log n/\log\log n)^2)$ cell-probe
lower bound for the dynamic 2D weighted orthogonal range counting problem
(2D-ORC) with $n/\mathrm{poly}\log n$ updates and $n$ queries, that holds even
for data structures with $\exp(-\tilde{\Omega}(n))$ success probability. This
result not only proves the highest amortized lower bound to date, but is also
tight in the strongest possible sense, as a matching upper bound can be
obtained by a deterministic data structure with worst-case operational time.
This is the first demonstration of a "sharp threshold" phenomenon for dynamic
data structures.
  Our broader motivation is that cell-probe lower bounds for exponentially
small success facilitate reductions from dynamic to static data structures. As
a proof-of-concept, we show that a slightly strengthened version of our lower
bound would imply an $\Omega((\log n /\log\log n)^2)$ lower bound for the
static 3D-ORC problem with $O(n\log^{O(1)}n)$ space. Such result would give a
near quadratic improvement over the highest known static cell-probe lower
bound, and break the long standing $\Omega(\log n)$ barrier for static data
structures.


title: Chemical abundances and kinematics of barium stars

abstract:
  In this paper we present an homogeneous analysis of photospheric abundances
based on high-resolution spectroscopy of a sample of 182 barium stars and
candidates. We determined atmospheric parameters, spectroscopic distances,
stellar masses, ages, luminosities and scale height, radial velocities,
abundances of the Na, Al, $alpha$-elements, iron-peak elements, and s-process
elements Y, Zr, La, Ce, and Nd. We employed the local-thermodynamic-equilibrium
model atmospheres of Kurucz and the spectral analysis code {\sc moog}. We found
that the metallicities, the temperatures and the surface gravities for barium
stars can not be represented by a single gaussian distribution. The abundances
of $alpha$-elements and iron peak elements are similar to those of field giants
with the same metallicity. Sodium presents some degree of enrichment in more
evolved stars that could be attributed to the NeNa cycle. As expected, the
barium stars show overabundance of the elements created by the s-process. By
measuring the mean heavy-element abundance pattern as given by the ratio
[s/Fe], we found that the barium stars present several degrees of enrichment.
We also obtained the [hs/ls] ratio by measuring the photospheric abundances of
the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and
the [hs/ls] ratios are strongly anti-correlated with the metallicity. Our
kinematical analysis showed that 90% of the barium stars belong to the thin
disk population. Based on their luminosities, none of the barium stars are
luminous enough to be an AGB star, nor to become self-enriched in the s-process
elements. Finally, we determined that the barium stars also follow an
age-metallicity relation.


title: Elementary constructions of non-discrete C*-simple groups

abstract:
  Recently Raum has given the first examples of locally compact non-discrete
groups with the simple reduced group C*-algebra, answering a question of de la
Harpe. Here we construct such groups whose proof relies only on results in the
discrete case.


title: Untwisting information from Heegaard Floer homology

abstract:
  The unknotting number of a knot is the minimum number of crossings one must
change to turn that knot into the unknot. We work with a generalization of
unknotting number due to Mathieu-Domergue, which we call the untwisting number.
The p-untwisting number is the minimum number (over all diagrams of a knot) of
full twists on at most 2p strands of a knot, with half of the strands oriented
in each direction, necessary to transform that knot into the unknot. In
previous work, we showed that the unknotting and untwisting numbers can be
arbitrarily different. In this paper, we show that a common route for
obstructing low unknotting number, the Montesinos trick, does not generalize to
the untwisting number. However, we use a different approach to get conditions
on the Heegaard Floer correction terms of the branched double cover of a knot
with untwisting number one. This allows us to obstruct several 10 and
11-crossing knots from being unknotted by a single positive or negative twist.
We also use the Ozsv\'ath-Szab\'o tau invariant and the Rasmussen s invariant
to differentiate between the p- and q-untwisting numbers for certain p,q > 1.


title: M3: Scaling Up Machine Learning via Memory Mapping

abstract:
  To process data that do not fit in RAM, conventional wisdom would suggest
using distributed approaches. However, recent research has demonstrated virtual
memory's strong potential in scaling up graph mining algorithms on a single
machine. We propose to use a similar approach for general machine learning. We
contribute: (1) our latest finding that memory mapping is also a feasible
technique for scaling up general machine learning algorithms like logistic
regression and k-means, when data fits in or exceeds RAM (we tested datasets up
to 190GB); (2) an approach, called M3, that enables existing machine learning
algorithms to work with out-of-core datasets through memory mapping, achieving
a speed that is significantly faster than a 4-instance Spark cluster, and
comparable to an 8-instance cluster.


title: Learning Global Features for Coreference Resolution

abstract:
  There is compelling evidence that coreference prediction would benefit from
modeling global information about entity-clusters. Yet, state-of-the-art
performance can be achieved with systems treating each mention prediction
independently, which we attribute to the inherent difficulty of crafting
informative cluster-level features. We instead propose to use recurrent neural
networks (RNNs) to learn latent, global representations of entity clusters
directly from their mentions. We show that such representations are especially
useful for the prediction of pronominal mentions, and can be incorporated into
an end-to-end coreference system that outperforms the state of the art without
requiring any additional search.


title:
Classical and quantum dynamics of a perfect fluid scalar-energy
  dependent metric cosmology

abstract:
  Inspired from the idea of minimally coupling of a real scalar field to
geometry, we investigate the classical and quantum models of a flat
energy-dependent FRW cosmology coupled to a perfect fluid in the framework of
the scalar-rainbow metric gravity. We use the standard Schutz' representation
for the perfect fluid and show that under a particular energy-dependent gauge
fixing, it may lead to the identification of a time parameter for the
corresponding dynamical system. It is shown that, under some circumstances on
the minisuperspace prob energy, the classical evolution of the of the universe
represents a late time expansion coming from a bounce instead of the big-bang
singularity. Then we go forward by showing that this formalism gives rise to a
Schr\"{o}dinger-Wheeler-DeWitt (SWD) equation for the quantum-mechanical
description of the model under consideration, the eigenfunctions of which can
be used to construct the wave function of the universe. We use the resulting
wave function in order to investigate the possibility of the avoidance of
classical singularities due to quantum effects by means of the many-worlds and
Bohmian interpretation of quantum cosmology.


title: The Ancient Astronomy of Easter Island: Venus and Aldebaran

abstract:
  One additional position of the famous Mataveri calendar of Easter Island has
been interpreted. New data on the watchings of Venus and Aldebaran have been
rendered. Some reports about the sun, the moon as well as Sirius are of our
interest, too.


title:
Einstein's Physical Strategy, Energy Conservation, Symmetries, and
  Stability: "but Grossmann & I believed that the conservation laws were not
  satisfied"

abstract:
  Recent work on the history of General Relativity by Renn, Sauer, Janssen et
al. shows that Einstein found his field equations partly by a physical strategy
including the Newtonian limit, the electromagnetic analogy, and energy
conservation. Such themes are similar to those later used by particle
physicists. How do Einstein's physical strategy and the particle physics
derivations compare? What energy-momentum complex(es) did he use and why? Did
Einstein tie conservation to symmetries, and if so, to which? Einstein used an
identity from his assumed linear coordinate covariance x'= Mx to relate it to
the canonical tensor. Usually he avoided using matter Euler-Lagrange equations
and so was not well positioned to use or reinvent the Herglotz-Mie-Born
understanding that the canonical tensor was conserved due to translation
symmetries, a result with roots in Lagrange, Hamilton and Jacobi. Whereas Mie
and Born were concerned about the canonical tensor's asymmetry, Einstein did
not need to worry because his Entwurf Lagrangian is modeled not so much on
Maxwell's theory as on a scalar theory. As a result, it also has 3 ghosts,
failing a 1920s-30s a priori particle physics stability test with antecedents
in Lagrange's and Dirichlet's stability work.
  This critique of the Entwurf theory can be compared with Einstein's 1915
critique of his Entwurf theory for not admitting rotating coordinates and not
getting Mercury's perihelion right.
  Particle physics also can be useful in the historiography of gravity and
space-time. This topic can be a useful case study in the history of science on
recently reconsidered questions of presentism, whiggism and the like.


title: Radiative Corrections to the Solar Lepton Mixing Sum Rule

abstract:
  The simple correlation among three lepton flavor mixing angles
$(\theta^{}_{12}, \theta^{}_{13}, \theta^{}_{23})$ and the leptonic Dirac
CP-violating phase $\delta$ is conventionally called a sum rule of lepton
flavor mixing, which may be derived from a class of neutrino mass models with
flavor symmetries. In this paper, we consider the solar lepton mixing sum rule
$\theta^{}_{12} \approx \theta^{\nu}_{12} + \theta^{}_{13} \cos \delta$, where
$\theta^\nu_{12}$ stems from a constant mixing pattern in the neutrino sector
and takes the value of $\theta^\nu_{12} = 45^\circ$ for the bi-maximal mixing
(BM), $\theta^\nu_{12} = \tan^{-1}(1/\sqrt{2}) \approx 35.3^\circ$ for the
tri-bimaximal mixing (TBM) or $\theta^\nu_{12} = \tan^{-1}\left[2/(\sqrt{5} +
1)\right] \approx 31.7^\circ$ for the golden-ratio mixing (GR), and investigate
the renormalization-group (RG) running effects on lepton flavor mixing
parameters when this sum rule is assumed at a superhigh-energy scale. For
illustration, we work within the framework of the minimal supersymmetric
standard model (MSSM), and implement the Bayesian approach to explore the
posterior distribution of $\delta$ at the low-energy scale, which becomes quite
broad when the RG running effects are significant. Moreover, we also discuss
the compatibility of the above three mixing scenarios with current neutrino
oscillation data, and observe that radiative corrections can increase such a
compatibility for the BM scenario, resulting in a weaker preference for the TBM
and GR ones.


title:
Two-dimensional Hybrid Simulations of Kinetic Plasma Turbulence: Current
  and Vorticity vs Proton Temperature

abstract:
  Proton temperature anisotropies between the directions parallel and
perpendicular to the mean magnetic field are usually observed in the solar wind
plasma. Here, we employ a high-resolution hybrid particle-in-cell simulation in
order to investigate the relation between spatial properties of the proton
temperature and the peaks in the current density and in the flow vorticity. Our
results indicate that, although regions where the proton temperature is
enhanced and temperature anisotropies are larger correspond approximately to
regions where many thin current sheets form, no firm quantitative evidence
supports the idea of a direct causality between the two phenomena. On the other
hand, quite a clear correlation between the behavior of the proton temperature
and the out-of-plane vorticity is obtained.


title:
Chromosome-wide simulations uncover folding pathway and 3D organization
  of interphase chromosomes

abstract:
  Three-dimensional interphase organization of metazoan genomes has been linked
to cellular identity. However, the principles governing 3D interphase genome
architecture and its faithful transmission through disruptive events of
cell-cycle, like mitosis, are not fully understood. By using Brownian dynamics
simulations of Drosophila chromosome 3R up to time-scales of minutes, we show
that chromatin binding profile of Polycomb-repressive-complex-1 robustly
predicts a sub-set of topologically associated domains (TADs), and inclusion of
other factors recapitulates the profile of all TADs, as observed
experimentally. Our simulations show that chromosome 3R attains interphase
organization from mitotic state by a two-step process in which formation of
local TADs is followed by long-range interactions. Our model also explains
statistical features and tracks the assembly kinetics of polycomb subnuclear
clusters. In conclusion, our approach can be used to predict structural and
kinetic features of 3D chromosome folding and its associated proteins in
biological relevant genomic and time scales.


title: Distribution-Constrained Optimal Stopping

abstract:
  We solve the problem of optimal stopping of a Brownian motion subject to the
constraint that the stopping time's distribution is a given measure consisting
of finitely-many atoms. In particular, we show that this problem can be
converted to a finite sequence of state-constrained optimal control problems
with additional states corresponding to the conditional probability of stopping
at each possible terminal time. The proof of this correspondence relies on a
new variation of the dynamic programming principle for state-constrained
problems which avoids measurable selection. We emphasize that distribution
constraints lead to novel and interesting mathematical problems on their own,
but also demonstrate an application in mathematical finance to model-free
superhedging with an outlook on volatility.


title:
Cage-jump motion reveals universal dynamics and non-universal structural
  features in glass forming liquids

abstract:
  The sluggish and heterogeneous dynamics of glass forming liquids is
frequently associated to the transient coexistence of two phases of particles,
respectively with an high and low mobility. In the absence of a dynamical order
parameter that acquires a transient bimodal shape, these phases are commonly
identified empirically, which makes difficult investigating their relation with
the structural properties of the system. Here we show that the distribution of
single particle diffusivities can be accessed within a Continuous Time Random
Walk description of the intermittent motion, and that this distribution
acquires a transient bimodal shape in the deeply supercooled regime, thus
allowing for a clear identification of the two coexisting phase. In a simple
two-dimensional glass forming model, the dynamic phase coexistence is
accompanied by a striking structural counterpart: the distribution of the
crystalline-like order parameter becomes also bimodal on cooling, with
increasing overlap between ordered and immobile particles. This simple
structural signature is absent in other models, such as the three-dimesional
Kob-Andersen Lennard-Jones mixture, where more sophisticated order parameters
might be relevant. In this perspective, the identification of the two dynamical
coexisting phases opens the way to deeper investigations of structure-dynamics
correlations.

categories: cond-mat.soft cond-mat.dis-nn cond-mat.mtrl-sci cond-mat.stat-mech


title:
Wisdom of the Crowd or Wisdom of a Few? An Analysis of Users' Content
  Generation

abstract:
  In this paper we analyze how user generated content (UGC) is created,
challenging the well known {\it wisdom of crowds} concept. Although it is known
that user activity in most settings follow a power law, that is, few people do
a lot, while most do nothing, there are few studies that characterize well this
activity. In our analysis of datasets from two different social networks,
Facebook and Twitter, we find that a small percentage of active users and much
less of all users represent 50\% of the UGC. We also analyze the dynamic
behavior of the generation of this content to find that the set of most active
users is quite stable in time. Moreover, we study the social graph, finding
that those active users are highly connected among them. This implies that most
of the wisdom comes from a few users, challenging the independence assumption
needed to have a wisdom of crowds. We also address the content that is never
seen by any people, which we call digital desert, that challenges the
assumption that the content of every person should be taken in account in a
collective decision. We also compare our results with Wikipedia data and we
address the quality of UGC content using an Amazon dataset. At the end our
results are not surprising, as the Web is a reflection of our own society,
where economical or political power also is in the hands of minorities.


title:
Exploring the Inert Doublet Model through the dijet plus missing
  transverse energy channel at the LHC

abstract:
  In this study of the Inert Doublet Model (IDM), we propose that the dijet +
missing transverse energy channel at the Large Hadron Collider (LHC) will be an
effective way of searching for the scalar particles of the IDM. This channel
receives contributions from gauge boson fusion, and $t-$channel production,
along with contributions from $H^+$ associated production. We perform the
analysis including study of the Standard Model (SM) background with assumed
systematic uncertainty, and optimise the selection criteria employing suitable
cuts on the kinematic variables to maximise the signal significance. We find
that with high luminosity option of the LHC, this channel has the potential to
probe the IDM in the mass range of up to about 400 GeV, which is not accessible
through other leptonic channels. In a scenario with light dark matter of mass
about 65 GeV, charged Higgs in the mass range of around 200 GeV provides the
best possibility with a signal significance of about $2\sigma$ at an integrated
luminosity of about 3000 fb$^{-1}$.


title: On-Shell Diagrams for N = 8 Supergravity Amplitudes

abstract:
  We define recursion relations for N = 8 supergravity amplitudes using a
generalization of the on-shell diagrams developed for planar N = 4
super-Yang-Mills. Although the recursion relations generically give rise to
non-planar on-shell diagrams, we show that at tree-level the recursion can be
chosen to yield only planar diagrams, the same diagrams occurring in the planar
N = 4 theory. This implies non-trivial identities for non-planar diagrams as
well as interesting relations between the N = 4 and N = 8 theories. We show
that the on-shell diagrams of N = 8 supergravity obey equivalence relations
analogous to those of N = 4 super-Yang-Mills, and we develop a systematic
algorithm for reading off Grassmannian integral formulae directly from the
on-shell diagrams. We also show that the 1-loop 4-point amplitude of N = 8
supergravity can be obtained from on-shell diagrams.


title: Leader election: A Markov chain approach

abstract:
  A well-studied randomized election algorithm proceeds as follows: In each
round the remaining candidates each toss a coin and leave the competition if
they obtain heads. Of interest is the number of rounds required and the number
of winners, both related to maxima of geometric random samples, as well as the
number of remaining participants as a function of the number of rounds. We
introduce two related Markov chains and use ideas and methods from discrete
potential theory to analyse the respective asymptotic behaviour as the initial
number of participants grows. One of the tools used is the approach via the
R\'enyi-Sukhatme representation of exponential order statistics, which was
first used in the leader election context by Bruss and Gr\"ubel in
\cite{BrGr03}.


title: Herbertsmithite and the Search for the Quantum Spin Liquid

abstract:
  Quantum spin liquids form a novel class of matter where, despite the
existence of strong exchange interactions, spins do not order down to the
lowest measured temperature. Typically, these occur in lattices that act to
frustrate the appearance of magnetism. In two dimensions, the classic example
is the kagome lattice composed of corner sharing triangles. There are a variety
of minerals whose transition metal ions form such a lattice. Hence, a number of
them have been studied, and were then subsequently synthesized in order to
obtain more pristine samples. Of particular note was the report in 2005 by Dan
Nocera's group of the synthesis of herbertsmithite, composed of a lattice of
copper ions sitting on a kagome lattice, which indeed does not order down to
the lowest measured temperature despite the existence of a large exchange
interaction of 17 meV. Over the past decade, this material has been extensively
studied, yielding a number of intriguing surprises that have in turn motivated
a resurgence of interest in the theoretical study of the spin 1/2 Heisenberg
model on a kagome lattice. In this colloquium article, I will review these
developments, and then discuss potential future directions, both experimental
and theoretical, as well as the challenge of doping these materials with the
hope that this could lead to the discovery of novel topological and
superconducting phases.


title:
Channel Estimation for Millimeter-Wave Massive MIMO with Hybrid
  Precoding over Frequency-Selective Fading Channels

abstract:
  Channel estimation for millimeter-wave (mmWave) massive MIMO with hybrid
precoding is challenging, since the number of radio frequency (RF) chains is
usually much smaller than that of antennas. To date, several channel estimation
schemes have been proposed for mmWave massive MIMO over narrow-band channels,
while practical mmWave channels exhibit the frequency-selective fading (FSF).
To this end, this letter proposes a multi-user uplink channel estimation scheme
for mmWave massive MIMO over FSF channels. Specifically, by exploiting the
angle-domain structured sparsity of mmWave FSF channels, a distributed
compressive sensing (DCS)-based channel estimation scheme is proposed.
Moreover, by using the grid matching pursuit strategy with adaptive measurement
matrix, the proposed algorithm can solve the power leakage problem caused by
the continuous angles of arrival or departure (AoA/AoD). Simulation results
verify that the good performance of the proposed solution.


title:
A new solar signal: Average maximum sunspot magnetic fields independent
  of activity cycle

abstract:
  Over the past five years, 2010-2015, we have observed, in the near infrared
(IR), the maximum magnetic field strengths for 4145 sunspot umbrae. Herein we
distinguish field strengths from field flux. (Most solar magnetographs measure
flux). Maximum field strength in umbrae is co-spatial with the position of
umbral minimum brightness (Norton and Gilman, 2004). We measure field strength
by the Zeeman splitting of the Fe 15648.5 A spectral line. We show that in the
IR no cycle dependence on average maximum field strength (2050 G) has been
found +/- 20 Gauss. A similar analysis of 17,450 spots observed by the
Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory reveal
the same cycle independence +/- 0.18 G., or a variance of 0.01%. This is found
not to change over the ongoing 2010-2015 minimum to maximum cycle. Conclude the
average maximum umbral fields on the Sun are constant with time.


title:
Cold Atmospheric Plasma discharged in Water and its Potential Use in
  Cancer Therapy

abstract:
  Cold atmospheric plasma (CAP) has been emerged as a novel technology for
cancer treatment. CAP can directly treat cells and tissue but such direct
application is limited to skin or can be invoked as a supplement during open
surgery. In this study we report indirect plasma treatment using CAP discharged
in DI water using three gases as carriers (argon, helium and nitrogen). Plasma
stimulated water was applied to human breast cancer cell line (MDA-MB-231). MTT
assay tests showed that using argon plasma had the strongest effect on inducing
apoptosis in cultured human breast cancer cells. This result is attributed to
the elevated production of the reactive oxygen species and reactive nitrogen
species in water in the case of argon plasma.


title: Distributed Gradient Descent in Bacterial Food Search

abstract:
  Communication and coordination play a major role in the ability of bacterial
cells to adapt to ever changing environments and conditions. Recent work has
shown that such coordination underlies several aspects of bacterial responses
including their ability to develop antibiotic resistance. Here we develop a new
distributed gradient descent method that helps explain how bacterial cells
collectively search for food in harsh environments using extremely limited
communication and computational complexity. This method can also be used for
computational tasks when agents are facing similarly restricted conditions. We
formalize the communication and computation assumptions required for successful
coordination and prove that the method we propose leads to convergence even
when using a dynamically changing interaction network. The proposed method
improves upon prior models suggested for bacterial foraging despite making
fewer assumptions. Simulation studies and analysis of experimental data
illustrate the ability of the method to explain and further predict several
aspects of bacterial swarm food search.


title:
Variational Latent Gaussian Process for Recovering Single-Trial Dynamics
  from Population Spike Trains

abstract:
  When governed by underlying low-dimensional dynamics, the interdependence of
simultaneously recorded population of neurons can be explained by a small
number of shared factors, or a low-dimensional trajectory. Recovering these
latent trajectories, particularly from single-trial population recordings, may
help us understand the dynamics that drive neural computation. However, due to
the biophysical constraints and noise in the spike trains, inferring
trajectories from data is a challenging statistical problem in general. Here,
we propose a practical and efficient inference method, called the variational
latent Gaussian process (vLGP). The vLGP combines a generative model with a
history-dependent point process observation together with a smoothness prior on
the latent trajectories. The vLGP improves upon earlier methods for recovering
latent trajectories, which assume either observation models inappropriate for
point processes or linear dynamics. We compare and validate vLGP on both
simulated datasets and population recordings from the primary visual cortex. In
the V1 dataset, we find that vLGP achieves substantially higher performance
than previous methods for predicting omitted spike trains, as well as capturing
both the toroidal topology of visual stimuli space, and the noise-correlation.
These results show that vLGP is a robust method with a potential to reveal
hidden neural dynamics from large-scale neural recordings.


title: Oppositions in a line segment

abstract:
  Traditional oppositions are at least two-dimensional in the sense that they
are built based on a famous bidimensional object called square of oppositions
and on one of its extensions such as Blanch\'e's hexagon. Instead of
two-dimensional objects, this article proposes a construction to deal with
oppositions in a one-dimensional line segment.


title: Uniform convergence of proliferating particles to the FKPP equation

abstract:
  In this paper we consider a system of Brownian particles with proliferation
whose rate depends on the empirical measure. The dependence is more local than
a mean field one and has been called moderate interaction by Oelschlager [17],
[18]. We prove that the empirical process converges, uniformly in the space
variable, to the solution of the Fisher-Kolmogorov-Petrowskii-Piskunov
equation. We use a semigroup approach which is new in the framework of these
systems and is inspired by some literature on stochastic partial differential
equations.


title: Studying on Opinion Evolution by Hamilton-Jacobi Equation

abstract:
  A physical description of an opinion evolution is conducted based on the
Hamilton-Jacobi equation derived from a generalized potential and the
corresponding Langevin equation. The investigation mainly focuses on the
heterogeneities such as age, connection circle and overall quality of the
participants involved in the opinion exchange process. The evolutionary
patterns of opinion can be described by solution of the Hamilton-Jacobi
equation, information entropy. The results show that the overall qualities of
the participants play critical roles in forming an opinion. The higher the
overall quality is, the easier the consensus can reach. The solution also
demonstrates that the age and the connection circle of the agents play equally
important roles in forming an opinion. The essence of the age, overall quality,
and connection circle corresponds to the maturity of thought (opinion inertia),
reason and intelligence, influence strength of the environment, respectively.
So the information entropy distributes in the phase planes (two variable
combinations out of the three---age, connection circle and overall quality)
exhibit the evolution rules of an opinion.


title: Feynman integrals, L-series and Kloosterman moments

abstract:
  This work lies at an intersection of three subjects: quantum field theory,
algebraic geometry and number theory, in a situation where dialogue between
practitioners has revealed rich structure. It contains a theorem and 7
conjectures, tested deeply by 3 optimized algorithms, on relations between
Feynman integrals and L-series defined by products, over the primes, of data
determined by moments of Kloosterman sums in finite fields. There is an
extended introduction, for readers who may not be familiar with all three of
these subjects. Notable new results include conjectural evaluations of
non-critical L-series of modular forms of weights 3, 4 and 6, by determinants
of Feynman integrals, an evaluation for the weight 5 problem, at a critical
integer, and formulas for determinants of arbitrary size, tested up to 30
loops. It is shown that the functional equation for Kloosterman moments
determines much but not all of the structure of the L-series. In particular,
for problems with odd numbers of Bessel functions, it misses a crucial feature
captured in this work by novel and intensively tested conjectures. For the
9-Bessel problem, these lead to an astounding compression of data at the
primes.


title: Binarized Neural Networks on the ImageNet Classification Task

abstract:
  We trained Binarized Neural Networks (BNNs) on the high resolution ImageNet
ILSVRC-2102 dataset classification task and achieved a good performance. With a
moderate size network of 13 layers, we obtained top-5 classification accuracy
rate of 84.1 % on validation set through network distillation, much better than
previous published results of 73.2% on XNOR network and 69.1% on binarized
GoogleNET. We expect networks of better performance can be obtained by
following our current strategies. We provide a detailed discussion and
preliminary analysis on strategies used in the network training.


title:
Radiative Transfer of HCN: Interpreting observations of hyperfine
  anomalies

abstract:
  Molecules with hyperfine splitting of their rotational line spectra are
useful probes of optical depth, via the relative line strengths of their
hyperfine components.The hyperfine splitting is particularly advantageous in
interpreting the physical conditions of the emitting gas because with a second
rotational transition, both gas density and temperature can be derived. For HCN
however, the relative strengths of the hyperfine lines are anomalous. They
appear in ratios which can vary significantly from source to source, and are
inconsistent with local thermodynamic equilibrium. This is the HCN hyperfine
anomaly, and it prevents the use of simple LTE models of HCN emission to derive
reliable optical depths. In this paper we demonstrate how to model HCN
hyperfine line emission, and derive accurate line ratios, spectral line shapes
and optical depths. We show that by carrying out radiative transfer
calculations over each hyperfine level individually, as opposed to summing them
over each rotational level, the anomalous hyperfine emission emerges naturally.
To do this requires not only accurate radiative rates between hyperfine states,
but also accurate collisional rates. We investigate the effects of different
sets of hyperfine collisional rates, derived via the 'proportional method' and
through direct recoupling calculations. Through an extensive parameter sweep
over typical low mass star forming conditions, we show the HCN line ratios to
be highly variable to optical depth. We also reproduce an observed effect
whereby the red-blue asymmetry of the hyperfine lines (an infall signature)
switches sense within a single rotational transition.


title: Old Game, New Rules: Rethinking The Form of Physics

abstract:
  We investigate the modeling capabilities of sets of coupled classical
harmonic oscillators (CHO) in the form of a modeling game. The application of
simple but restrictive rules of the game lead to conditions for an isomorphism
between Lie-algebras and real Clifford algebras. We show that the correlations
between two coupled classical oscillators find their natural description in the
Dirac algebra and allow to model aspects of special relativity, inertial
motion, electromagnetism and quantum phenomena including spin in one go. The
algebraic properties of Hamiltonian motion of low-dimensional systems can
generally be related to certain types of interactions and hence to the
dimensionality of emergent space-times. We describe the intrinsic connection
between phase space volumes of a 2-dimensional oscillator and the Dirac
algebra. In this version of a phase space interpretation of quantum mechanics
the (components of the) spinor wave-function in momentum space are abstract
canonical coordinates, and the integrals over the squared wave function
represents second moments in phase space. The wave function in ordinary
space-time can be obtained via Fourier transformation. Within this modeling
game, 3+1-dimensional space-time is interpreted as a structural property of
electromagnetic interaction. A generalization selects a series of Clifford
algebras of specific dimensions with similar properties, specifically also 10-
and 26-dimensional real Clifford algebras.


title: Computing with functions in spherical and polar geometries II. The disk

abstract:
  A collection of algorithms is described for numerically computing with smooth
functions defined on the unit disk. Low rank approximations to functions in
polar geometries are formed by synthesizing the disk analogue of the double
Fourier sphere method with a structure-preserving variant of iterative Gaussian
elimination that is shown to converge geometrically for certain analytic
functions. This adaptive procedure is near-optimal in its sampling strategy,
producing approximants that are stable for differentiation and facilitate the
use of FFT-based algorithms in both variables. The low rank form of the
approximants is especially useful for operations such as integration and
differentiation, reducing them to essentially 1D procedures, and it is also
exploited to formulate a new fast disk Poisson solver that computes low rank
approximations to solutions. This work complements a companion paper (Part I)
on computing with functions on the surface of the unit sphere.


title:
CLEAR: Cross-Layer Exploration for Architecting Resilience - Combining
  Hardware and Software Techniques to Tolerate Soft Errors in Processor Cores

abstract:
  We present a first of its kind framework which overcomes a major challenge in
the design of digital systems that are resilient to reliability failures:
achieve desired resilience targets at minimal costs (energy, power, execution
time, area) by combining resilience techniques across various layers of the
system stack (circuit, logic, architecture, software, algorithm). This is also
referred to as cross-layer resilience. In this paper, we focus on
radiation-induced soft errors in processor cores. We address both single-event
upsets (SEUs) and single-event multiple upsets (SEMUs) in terrestrial
environments. Our framework automatically and systematically explores the large
space of comprehensive resilience techniques and their combinations across
various layers of the system stack (586 cross-layer combinations in this
paper), derives cost-effective solutions that achieve resilience targets at
minimal costs, and provides guidelines for the design of new resilience
techniques. We demonstrate the practicality and effectiveness of our framework
using two diverse designs: a simple, in-order processor core and a complex,
out-of-order processor core. Our results demonstrate that a carefully optimized
combination of circuit-level hardening, logic-level parity checking, and
micro-architectural recovery provides a highly cost-effective soft error
resilience solution for general-purpose processor cores. For example, a 50x
improvement in silent data corruption rate is achieved at only 2.1% energy cost
for an out-of-order core (6.1% for an in-order core) with no speed impact.
However, selective circuit-level hardening alone, guided by a thorough analysis
of the effects of soft errors on application benchmarks, provides a
cost-effective soft error resilience solution as well (with ~1% additional
energy cost for a 50x improvement in silent data corruption rate).


title: A note on non-broken-circuit sets and the chromatic polynomial

abstract:
  I demonstrate several generalizations of a classical formula for the
chromatic polynomial of a graph -- namely, of Whitney's theorem. One
generalization allows the exclusion of only some broken circuits, whereas
another weighs these broken circuits with weight monomials instead of excluding
them; yet another extends the theorem to the chromatic symmetric functions, and
yet another replaces the graph by a matroid. Most of these generalizations can
be combined (albeit not all of them: matroids do not seem to have chromatic
symmetric functions).


title:
Four allotropes of semiconducting layered Arsenic which switch into a
  topological insulator via an electric field: A computational study

abstract:
  We propose four different thermodynamically stable structural phases of
arsenic monolayers based on ab-initio density functional theory calculations
all of which undergo a topological phase transition on application of a
perpendicular electric field. All the four arsenic monolayer allotropes have a
wide band gap, varying from 1.21 eV to 3.0 eV (based on GW calculations), and
in general they undergo a metal-insulator quantum phase transition on
application of uniaxial in-layer strain. Additionally an increasing transverse
electric field induces band-inversion at the {\Gamma} point in all four
monolayer allotropes, leading to a nontrivial topological phase (insulating for
three and metallic for one allotrope), characterized by the switching of the Z2
index, from 0 (before band inversion) to 1 (after band inversion). The
topological phase tuned by the transverse electric field, should support
spin-separated gapless edge states which should manifest in quantum spin Hall
effect.