title:
DUSTiNGS III: Distribution of Intermediate-Age and Old Stellar
  Populations in Disks and Outer Extremities of Dwarf Galaxies

abstract:
  We have traced the spatial distributions of intermediate-age and old stars in
nine dwarf galaxies in the distant parts of the Local Group, using multi-epoch
3.6 and 4.5 micron data from the DUST in Nearby Galaxies with Spitzer
(DUSTiNGS) survey. Using complementary optical imaging from the Hubble Space
Telescope, we identify the tip of the red giant branch (TRGB) in the 3.6 micron
photometry, separating thermally-pulsating asymptotic giant branch (TP-AGB)
stars from the larger red giant branch (RGB) populations. Unlike the constant
TRGB in the I-band, at 3.6 micron the TRGB magnitude varies by ~0.7 mag, making
it unreliable as a distance indicator. The intermediate-age and old stars are
well mixed in two-thirds of the sample with no evidence of a gradient in the
ratio of the intermediate-age to old stellar populations outside the central
~1-2'. Variable AGB stars are detected in the outer extremities of the
galaxies, indicating that chemical enrichment from these dust-producing stars
may occur in the outer regions of galaxies with some frequency. Theories of
structure formation in dwarf galaxies must account for the lack of radial
gradients in intermediate-age populations and the presence of these stars in
the outer extremities of dwarfs. Finally, we identify unique features in
individual galaxies, such as extended tidal features in Sex A and Sag DIG and a
central concentration of AGB stars in the inner regions of NGC 185 and NGC 147.


title: The Panchromatic STARBurst IRregular Dwarf Survey (STARBIRDS) Data

abstract:
  Understanding star formation in resolved low mass systems requires the
integration of information obtained from observations at different wavelengths.
We have combined new and archival multi-wavelength observations on a set of 20
nearby starburst and post-starburst dwarf galaxies to create a data archive of
calibrated, homogeneously reduced images. Named the panchromatic "STARBurst
IRregular Dwarf Survey" (STARBIRDS) archive, the data are publicly accessible
through the Mikulski Archive for Space Telescopes (MAST). This first release of
the archive includes images from the Galaxy Evolution Explorer Telescope
(GALEX), the Hubble Space Telescope (HST), and the Spitzer Space Telescope
(Spitzer) MIPS instrument. The datasets include flux calibrated, background
subtracted images, that are registered to the same world coordinate system.
Additionally, a set of images are available which are all cropped to match the
HST field of view. The GALEX and Spitzer images are available with foreground
and background contamination masked. Larger GALEX images extending to 4 times
the optical extent of the galaxies are also available. Finally, HST images
convolved with a 5 arcsec point spread function and rebinned to the larger
pixel scale of the GALEX and Spitzer 24 micron images are provided. Future
additions are planned that will include data at other wavelengths such as
Spitzer IRAC, ground based Halpha, Chandra X-ray, and Green Bank Telescope HI
imaging.


title: Search for Heavy Stops with Merged Top-Jets

abstract:
  We study an interesting region of phase space at the LHC for pair-produced
stops decaying into hadronic top quarks and light neutralinos. After imposing a
sizeable cut on the missing transverse energy, which is the key variable for
reducing backgrounds, we have found that the two hadronic tops are likely to
merge into a single fat jet. We develop a jet-substructure-based strategy to
tag the two merged top-jets and utilize the MT2 variable to further reduce the
backgrounds. We obtain about a 50% increase to the ratio of the signal over
background and a mild increase on the signal discovery significance, based on a
signal with a 1.2 TeV stop and a 100 GeV neutralino, for the 13 TeV LHC with
100 fb$^{-1}$. The general event kinematics could also occur and be explored
for other new physics signatures with large missing transverse energy.


title:
Magnetic Properties of Solar Active Regions that Govern Large Solar
  Flares and Eruptions

abstract:
  Solar flares and coronal mass ejections (CMEs), especially the larger ones,
emanate from active regions (ARs). With the aim to understand the magnetic
properties that govern such flares and eruptions, we systematically survey all
flare events with GOES levels of >=M5.0 within 45 deg from disk center between
May 2010 and April 2016. These criteria lead to a total of 51 flares from 29
ARs, for which we analyze the observational data obtained by the Solar Dynamics
Observatory. More than 80% of the 29 ARs are found to exhibit delta-sunspots
and at least three ARs violate Hale's polarity rule. The flare durations are
approximately proportional to the distance between the two flare ribbons, to
the total magnetic flux inside the ribbons, and to the ribbon area. From our
study, one of the parameters that clearly determine whether a given flare event
is CME-eruptive or not is the ribbon area normalized by the sunspot area, which
may indicate that the structural relationship between the flaring region and
the entire AR controls CME productivity. AR characterization show that even
X-class events do not require delta-sunspots or strong-field, high-gradient
polarity inversion lines. An investigation of historical observational data
suggests the possibility that the largest solar ARs, with magnetic flux of
2x10^23 Mx, might be able to produce "superflares" with energies of order of
10^34 erg. The proportionality between the flare durations and magnetic
energies is consistent with stellar flare observations, suggesting a common
physical background for solar and stellar flares.


title: $Z$ boson mediated dark matter beyond the effective theory

abstract:
  Direct detection bounds are beginning to constrain a very simple model of
weakly interacting dark matter---a Majorana fermion with a coupling to the $Z$
boson. In a particularly straightforward gauge-invariant realization, this
coupling is introduced via a higher-dimensional operator. While attractive in
its simplicity, this model generically induces a large $\rho$ parameter. An
ultraviolet completion that avoids an overly large contribution to $\rho$ is
the singlet-doublet model. We revisit this model, focusing on the Higgs blind
spot region of parameter space where spin-independent interactions are absent.
This model successfully reproduces dark matter with direct detection mediated
by the $Z$ boson, but whose cosmology may depend on additional couplings and
states. Future direct detection experiments should effectively probe a
significant portion of this parameter space, aside from a small coannihilating
region. As such, $Z$-mediated thermal dark matter as realized in the
singlet-doublet model represents an interesting target for future searches.


title: Duality and bosonization of (2+1)d Majorana fermions

abstract:
  We construct a dual bosonized description of a massless Majorana fermion in
$(2+1)d$. In contrast to Dirac fermions, for which a bosonized description can
be constructed using a flux attachment procedure, neutral Majorana fermions
call for a different approach. We argue that the dual theory is an $SO(N)_1$
Chern-Simons gauge theory with a critical $SO(N)$ vector bosonic matter field
($N \geq 3$). The monopole of the $SO(N)$ gauge field is identified with the
Majorana fermion. We provide evidence for the duality by establishing the
correspondence of adjacent gapped phases and by a parton construction. We also
propose a generalization of the duality to $N_f$ flavors of Majorana fermions,
and discuss possible resolutions of a caveat associated with an emergent global
$Z_2$ symmetry. Finally, we conjecture a dual description of an $\mathcal{N} =
1$ supersymmetric fixed point in $(2+1)d$, which is realized by tuning a single
flavor of Majorana fermions to an interacting (Gross-Neveu) critical point.


title:
Critical features of nonlinear optical isolators for improved
  nonreciprocity

abstract:
  Light propagation in a nonlinear optical medium is nonreciprocal for
spatially asymmetric linear permittivity. We here examine physical mechanism
and properties of such nonreciprocity (NR). For this, we calculate transmission
of light through two models of a nonlinear optical isolator consisting of (a) a
two-level atom and (b) a driven $\Lambda$-type three-level atom coupled
asymmetrically to light inside open waveguides. We find a higher NR in the
model (b) than in the model (a) due to a stronger optical nonlinearity in the
former. We determine the critical intensity of incident light for maximum NR
and a dependence of the corresponding NR on asymmetry in the coupling.
Surprisingly, we find that it is mainly coherent elastic scattering compared to
incoherent scattering of incident light which causes maximum NR near the
critical intensity. We also show a higher NR of an incident light in the
presence of an additional weak light at the opposite port.


title: The XMM Cluster Outskirts Project (X-COP)

abstract:
  Galaxy clusters are thought to grow hierarchically through the continuous
merging and accretion of smaller structures across cosmic time. In the local
Universe, these phenomena are still active in the outer regions of massive
clusters ($R>R_{500}$), where the matter distribution is expected to become
clumpy and asymmetric because of the presence of accreting structures. We
present the XMM-Newton Cluster Outskirts Project (X-COP), which targets the
outer regions of a sample of 13 massive clusters
($M_{500}>3\times10^{14}M_\odot$) in the redshift range 0.04-0.1 at uniform
depth. The sample was selected based on the signal-to-noise ratio in the Planck
Sunyaev-Zeldovich (SZ) survey with the aim of combining high-quality X-ray and
SZ constraints throughout the entire cluster volume. Our observing strategy
allows us to reach a sensitivity of $3\times10^{-16}$ ergs cm$^{-2}$ s$^{-1}$
arcmin$^{-2}$ in the [0.5-2.0] keV range thanks to a good control of systematic
uncertainties. The combination of depth and field of view achieved in X-COP
will allow us to pursue the following main goals: i) measure the distribution
of entropy and thermal energy to an unprecedented level of precision; ii)
assess the presence of non-thermal pressure support in cluster outskirts; iii)
study the occurrence and mass distribution of infalling gas clumps. We
illustrate the capabilities of the program with a pilot study on the cluster
Abell 2142.


title: Farthest Neighbor: The Distant Milky Way Satellite Eridanus II

abstract:
  We present Magellan/IMACS spectroscopy of the recently-discovered Milky Way
satellite Eridanus II (Eri II). We identify 28 member stars in Eri II, from
which we measure a systemic radial velocity of $v_{\rm hel} = 75.6 \pm
1.3~\mbox{(stat.)} \pm 2.0~\mbox{(sys.)}~\mathrm{km\,s^{-1}}$ and a velocity
dispersion of $6.9^{+1.2}_{-0.9}~\mathrm{km\,s^{-1}}$. Assuming that Eri~II is
a dispersion-supported system in dynamical equilibrium, we derive a mass within
the half-light radius of Eri II is $1.2^{+0.4}_{-0.3} \times
10^{7}~\mathrm{M_\odot}$, indicating a mass-to-light ratio of
$420^{+210}_{-140}~\mathrm{M_\odot}/\mathrm{L_\odot}$ and confirming that it is
a dark matter-dominated dwarf galaxy. From the equivalent width measurements of
the CaT lines of 16 red giant member stars, we derive a mean metallicity of
${\rm [Fe/H]} = -2.38 \pm 0.13$ and a metallicity dispersion of $\sigma_{\rm
[Fe/H]} = 0.47 ^{+0.12}_{-0.09}$. The velocity of Eri II in the Galactic
Standard of Rest frame is $v_{\rm GSR} = -66.6~\mathrm{km\,s^{-1}}$, indicating
that either Eri II is falling into the Milky Way potential for the first time
or it has passed the apocenter of its orbit on a subsequent passage. At a
Galactocentric distance of $\sim$370 kpc, Eri II is one of the Milky Way's most
distant satellites known. Additionally, we show that the bright blue stars
previously suggested to be a young stellar population are not associated with
Eri II. The lack of gas and recent star formation in Eri II is surprising given
its mass and distance from the Milky Way, and may place constraints on models
of quenching in dwarf galaxies and on the distribution of hot gas in the Milky
Way halo. Furthermore, the large velocity dispersion of Eri II can be combined
with the existence of a central star cluster to constrain MACHO dark matter
with mass $\gtrsim10~\mathrm{M_\odot}$.


title: Learning Detailed Face Reconstruction from a Single Image

abstract:
  Reconstructing the detailed geometric structure of a face from a given image
is a key to many computer vision and graphics applications, such as motion
capture and reenactment. The reconstruction task is challenging as human faces
vary extensively when considering expressions, poses, textures, and intrinsic
geometries. While many approaches tackle this complexity by using additional
data to reconstruct the face of a single subject, extracting facial surface
from a single image remains a difficult problem. As a result, single-image
based methods can usually provide only a rough estimate of the facial geometry.
In contrast, we propose to leverage the power of convolutional neural networks
to produce a highly detailed face reconstruction from a single image. For this
purpose, we introduce an end-to-end CNN framework which derives the shape in a
coarse-to-fine fashion. The proposed architecture is composed of two main
blocks, a network that recovers the coarse facial geometry (CoarseNet),
followed by a CNN that refines the facial features of that geometry (FineNet).
The proposed networks are connected by a novel layer which renders a depth
image given a mesh in 3D. Unlike object recognition and detection problems,
there are no suitable datasets for training CNNs to perform face geometry
reconstruction. Therefore, our training regime begins with a supervised phase,
based on synthetic images, followed by an unsupervised phase that uses only
unconstrained facial images. The accuracy and robustness of the proposed model
is demonstrated by both qualitative and quantitative evaluation tests.


title: An adiabatic Leakage Elimination Operator in experimental framework

abstract:
  Adiabatic evolution is used in a variety of quantum information processing
tasks. However, the elimination of errors is not as well-developed as it is for
circuit model processing. Here, we present a strategy to accelerate a reliable
quantum adiabatic process by adding Leakage Elimination Operators (LEO) to the
evolution which are a sequence of pulse controls acting in an adiabatic
subspace. Using the Feshbach $PQ$ partitioning technique, we obtain an
analytical solution which traces the footprint of the target eigenstate. The
effectiveness of the LEO is independent of the specific form of the pulse but
depends on the average frequency of the control function. Furthermore, we give
the exact expression of the control function in an experimental framework by a
counter unitary transformation, thus the physical meaning of the LEO is clear.
Our results reveal the equivalence of the control function between two
different formalisms which aids in implementation.


title:
The maximum sizes of large scale structures in alternative theories of
  gravity

abstract:
  The maximum size of a cosmic structure is given by the maximum turnaround
radius -- the scale where the attraction due to its mass is balanced by the
repulsion due to dark energy. We derive generic formulae for the estimation of
the maximum turnaround radius in any theory of gravity obeying the Einstein
equivalence principle, in two situations: on a spherically symmetric spacetime
and on a perturbed Friedman-Robertson-Walker spacetime. We show that the two
formulae agree. As an application of our formula, we calculate the maximum
turnaround radius in the case of the Brans-Dicke theory of gravity. We find
that for this theory, such maximum sizes always lie above the \LCDM value, by a
factor $1 + \frac{1}{3\omega}$, where $\omega\gg 1$ is the Brans-Dicke
parameter, implying consistency of the theory with current data.


title: Recent progress in anisotropic hydrodynamics

abstract:
  The quark-gluon plasma created in a relativistic heavy-ion collisions
possesses a sizable pressure anisotropy in the local rest frame at very early
times after the initial nuclear impact and this anisotropy only slowly relaxes
as the system evolves. In a kinetic theory picture, this translates into the
existence of sizable momentum-space anisotropies in the underlying partonic
distribution functions, <p_L^2> << <p_T^2>. In such cases, it is better to
reorganize the hydrodynamical expansion by taking into account momentum-space
anisotropies at leading-order in the expansion instead of as a perturbative
correction to an isotropic distribution. The resulting anisotropic
hydrodynamics framework has been shown to more accurately describe the dynamics
of rapidly expanding systems such as the quark-gluon plasma. In this
proceedings contribution, I review the basic ideas of anisotropic
hydrodynamics, recent progress, and present a few preliminary phenomenological
predictions for identified particle spectra and elliptic flow.


title: Regularization of divergent integrals

abstract:
  We study the Hadamard finite part of divergent integrals of differential
forms with singularities on submanifolds. We give formulae for the dependence
of the finite part on the choice of regularization and express them in terms of
a suitable local residue map. The cases where the submanifold is a complex
hypersurface in a complex manifold and where it is a boundary component of a
manifold with boundary, arising in string perturbation theory, are treated in
more detail.


title: Morphological Inversion of Complex Diffusion

abstract:
  Epidemics, neural cascades, power failures, and many other phenomena can be
described by a diffusion process on a network. To identify the causal origins
of a spread, it is often necessary to identify the triggering initial node.
Here we define a new morphological operator and use it to detect the origin of
a diffusive front, given the final state of a complex network. Our method
performs better than randomized trials as well as centrality based methods.
More importantly, our method is applicable regardless of the specifics of the
forward model, and therefore can be applied to a wide range of systems such as
identifying the patient zero in an epidemic, pinpointing the neuron that
triggers a cascade, identifying the original malfunction that causes a
catastrophic infrastructure failure, and inferring the ancestral species from
which a heterogeneous population evolves.


title:
Enumeration of permutations indexing local complete intersection
  Schubert varieties

abstract:
  We find the generating function for the permutation class
$\mathcal{A}'=\text{Av}(52341,53241,52431,35142,42513,351624)$ whose
permutations index local complete intersection Schubert varieties. The method
we apply is the extension of how Albert and Brignall discover the generating
function for $\mathcal{A}=\text{Av}(4231,35142,42513,351624)$ in their paper.
This completes the enumerations of all classical permutation classes indexing
certain types of Schubert varieties.


title: Present Status of b -> s l+ l- Anomalies

abstract:
  We discuss the observed deviations in b -> s l+ l- processes from the
Standard Model predictions and present global fits for the New Physics
description of these anomalies. We further investigate the stability of the
global fits under different theoretical assumptions and suggest strategies and
a number of observables to clear up the source of the anomalies.


title: Constraints on the CP-Violating MSSM

abstract:
  We discuss the prospects for observing CP violation in the MSSM with six
CP-violating phases, using a geometric approach to maximise CP-violating
observables subject to the experimental upper bounds on electric dipole
moments. We consider constraints from Higgs physics, flavour physics, the dark
matter relic density and spin-independent scattering cross section with matter.


title:
UV completion of the Starobinsky model, tensor-to-scalar ratio, and
  constraints on non-locality

abstract:
  In this paper, we build upon the successes of the ultraviolet (UV) completion
of the Starobinsky model of inflation. This involves an extension of the
Einstein-Hilbert term by an infinite covariant derivative theory of gravity,
which is quadratic in curvature. It has been shown that such a theory can
potentially resolve the cosmological singularity for a flat, homogeneous and
isotropic geometry, and now it can also provide a successful cosmological
inflation model, which in the infrared matches all the predictions of the
Starobinsky model of inflation. The aim of this note is to show that the
tensor-to-scalar ratio is modified by the scale of non-locality, and in general
a wider range of tensor-to-scalar ratios can be obtained in this class of
model, which can put a lower bound on the scale of non-locality for the first
time as large as the O$(10^{14})$ GeV.


title:
The Fluctuating Two-Ray Fading Model: Statistical Characterization and
  Performance Analysis

abstract:
  We introduce the Fluctuating Two-Ray (FTR) fading model, a new statistical
channel model that consists of two fluctuating specular components with random
phases plus a diffuse component. The FTR model arises as the natural
generalization of the two-wave with diffuse power (TWDP) fading model; this
generalization allows its two specular components to exhibit a random amplitude
fluctuation. Unlike the TWDP model, all the chief probability functions of the
FTR fading model (PDF, CDF and MGF) are expressed in closed-form, having a
functional form similar to other state-of-the-art fading models. We also
provide approximate closed-form expressions for the PDF and CDF in terms of a
finite number of elementary functions, which allow for a simple evaluation of
these statistics to an arbitrary level of precision. We show that the FTR
fading model provides a much better fit than Rician fading for recent
small-scale fading measurements in 28 GHz outdoor millimeter-wave channels.
Finally, the performance of wireless communication systems over FTR fading is
evaluated in terms of the bit error rate and the outage capacity, and the
interplay between the FTR fading model parameters and the system performance is
discussed. Monte Carlo simulations have been carried out in order to validate
the obtained theoretical expressions.


title: Small-scale galaxy clustering in the EAGLE simulation

abstract:
  We study present-day galaxy clustering in the EAGLE cosmological
hydrodynamical simulation. EAGLE's galaxy formation parameters were calibrated
to reproduce the redshift $z=0.1$ galaxy stellar mass function, and the
simulation also reproduces galaxy colours well. The simulation volume is too
small to correctly sample large-scale fluctuations and we therefore concentrate
on scales smaller than a few mega parsecs. We find very good agreement with
observed clustering measurements from the Galaxy And Mass Assembly (GAMA)
survey, when galaxies are binned by stellar mass, color, or luminosity.
However, low-mass red-galaxies are clustered too strongly, which is at least
partly due to limited numerical resolution. Apart from this limitation, we
conclude that EAGLE galaxies inhabit similar dark matter haloes as observed
GAMA galaxies, and that the radial distribution of satellite galaxies as
function of stellar mass and colour is similar to that observed as well.


title: Global fits of scalar singlet dark matter with GAMBIT

abstract:
  The wide range of probes of physics beyond the standard model leads to the
need for tools that combine experimental results to make the most robust
possible statements about the validity of theories and the preferred regions of
their parameter space. Here we introduce a new code for such analyses: GAMBIT,
the Global and Modular BSM Inference Tool. GAMBIT is a flexible and extensible
framework for global fits of essentially any BSM theory. The code currently
incorporates direct and indirect searches for dark matter, limits on production
of new particles from the LHC and LEP, complete flavor constraints from LHCb,
LHC Higgs production and decay measurements, and various electroweak precision
observables. Here we present an overview of the code's capabilities, followed
by preliminary results from scans of the scalar singlet dark matter model.


title: Sparse Control for Dynamic Movement Primitives

abstract:
  This paper describes the use of spatially-sparse inputs to influence global
changes in the behavior of Dynamic Movement Primitives (DMPs). The dynamics of
DMPs are analyzed through the framework of contraction theory as networked
hierarchies of contracting or transversely contracting systems. Within this
framework, sparsely-inhibited rhythmic DMPs (SI-RDMPs) are introduced to both
inhibit or enable rhythmic primitives through spatially-sparse modification of
the DMP dynamics. SI-RDMPs are demonstrated in experiments to manage start-stop
transitions for walking experiments with the MIT Cheetah. New analytical
results on the coupling of oscillators with diverse natural frequencies are
also discussed.


title: On S-coherence

abstract:
  Recentely, Anderson and Dumitrescu's $S$-finiteness has attracted the
interest of several authors. In this paper, we introduce the notions of
$S$-finitely presented modules and then of $S$-coherent rings which are
$S$-versions of finitely presented modules and coherent rings, respectively.
Among other results, we give an $S$-version of the classical Chase's
characterization of coherent rings. We end the paper with a brief discussion on
other $S$-versions of finitely presented modules and coherent rings. We prove
that these last $S$-versions can be characterized in terms of localization.


title:
Gauge-free cluster variational method by maximal messages and moment
  matching

abstract:
  We present a new implementation of the Cluster Variational Method (CVM) as a
message passing algorithm. The kind of message passing algorithms used for CVM,
usually named Generalized Belief Propagation, are a generalization of the
Belief Propagation algorithm in the same way that CVM is a generalization of
the Bethe approximation for estimating the partition function. However, the
connection between fixed points of GBP and the extremal points of the CVM
free-energy is usually not a one-to-one correspondence, because of the
existence of a gauge transformation involving the GBP messages.
  Our contribution is twofold. Firstly we propose a new way of defining
messages (fields) in a generic CVM approximation, such that messages arrive on
a given region from all its ancestors, and not only from its direct parents, as
in the standard Parent-to-Child GBP. We call this approach maximal messages.
Secondly we focus on the case of binary variables, re-interpreting the messages
as fields enforcing the consistency between the moments of the local (marginal)
probability distributions. We provide a precise rule to enforce all
consistencies, avoiding any redundancy, that would otherwise lead to a gauge
transformation on the messages. This moment matching method is gauge free, i.e.
it guarantees that the resulting GBP is not gauge invariant.
  We apply our maximal messages and moment matching GBP to obtain an analytical
expression for the critical temperature of the Ising model in general
dimensions at the level of plaquette-CVM. The values obtained outperform Bethe
estimates, and are comparable with loop corrected Belief Propagation equations.
The method allows for a straightforward generalization to disordered systems.


title: Impact of non-standard interactions on neutrino-nucleon scattering

abstract:
  Non-standard neutrino-nucleon interaction is formulated and explored within
the energy range of quasi-elastic scattering. In particular, the study focuses
on the neutral-current elastic (anti)neutrino scattering off nucleons described
by the exotic reactions $\nu_\alpha ({\bar \nu}_\alpha) + n \rightarrow
\nu_\beta ({\bar \nu}_\beta) + n $ and $ \nu_\alpha ({\bar \nu}_\alpha) + p
\rightarrow \nu_\beta ({\bar \nu}_\beta) + p$, which provide corrections to the
dominant Standard Model processes. In this context, it is shown that the
required exotic nucleon form factors may have a significant impact on the
relevant cross sections. Besides cross sections, the event rate is expected to
be rather sensitive to the magnitude of the lepton-flavour violating parameters
resulting in an excess of events. The overlap of non-standard interactions and
strange quark contributions, in the region of few GeV neutrino energies, is
also examined. The formalism is applied for the case of the relevant
neutrino-nucleon scattering experiments (LSND, MiniBooNE, etc.) and motivates
the notion that such facilities have high potential to probe NSI.


title: Scaling Laws for Maximum Coloring of Random Geometric Graphs

abstract:
  We examine maximum vertex coloring of random geometric graphs, in an
arbitrary but fixed dimension, with a constant number of colors. Since this
problem is neither scale-invariant nor smooth, the usual methodology to obtain
limit laws cannot be applied. We therefore leverage different concepts based on
subadditivity to establish convergence laws for the maximum number of vertices
that can be colored. For the constants that appear in these results, we provide
the exact value in dimension one, and upper and lower bounds in higher
dimensions.


title:
The potential of asteroseismology for probing the core chemical
  stratification in white dwarf stars

abstract:
  Context. The details of the C/O core structure in white dwarf stars has
mostly remained inaccessible to the technique of asteroseismology, despite
several attempts carried out in the past.
  Aims. We re-assess the potential of asteroseismology for probing the chemical
stratification in white dwarf cores, in light of new highly efficient tools
recently developed for that purpose.
  Methods. Using the forward modeling approach and a new parameterization for
the core chemical stratification in ZZ Ceti stars, we test several situations
typical of the usually limited constraints available, such as small numbers of
observed independent modes, to carry out asteroseismology of these stars.
  Results. We find that, even with a limited number of modes, the core chemical
stratification (in particular, the location of the steep chemical transitions
expected in the oxygen profile) can be determined quite precisely due to the
significant sensitivity of some confined modes to partial reflexion (trapping)
effects. These effects are similar to the well known trapping induced by the
shallower chemical transitions at the edge of the core and at the bottom of the
H-rich envelope. We also find that success to unravel the core structure
depends on the information content of the available seismic data. In some
cases, it may not be possible to isolate a unique, well-defined seismic
solution and the problem remains degenerate.
  Conclusions. Our results establish that constraining the core chemical
stratification in white dwarf stars based solely on asteroseismology is
possible, an opportunity that we have started to exploit.


title: Non-ideal memristors for a non-ideal world

abstract:
  Memristors have pinched hysteresis loops in the $V-I$ plane. Ideal memristors
are everywhere non-linear, cross at zero and are rotationally symmetric. In
this paper we extend memristor theory to produce different types of
non-ideality and find that: including a background current (such as an ionic
current) moves the crossing point away from zero; including a degradation
resistance (that increases with experimental time) leads to an asymmetry;
modelling a low resistance filament in parallel describes triangular $V-I$
curves with a straight-line low resistance state. A novel measurement of
hysteresis asymmetry was introduced based on hysteresis and it was found that
which lobe was bigger depended on the size of the breaking current relative to
the memristance. The hysteresis varied differently with each type of
non-ideality, suggesting that measurements of several device I-V curves and
calculation of these parameters could give an indication of the underlying
mechanism.


title:
Vector Nonlocal Euclidean Median: Principal Bundle Captures The Nature
  of Patch Space

abstract:
  We extensively study the rotational group structure inside the patch space by
introducing the fiber bundle structure. The rotational group structure leads to
a new image denoising algorithm called the \textit{vector non-local Euclidean
median} (VNLEM). The theoretical aspect of VNLEM is studied, which explains why
the VNLEM and traditional non-local mean/non-local Euclidean median (NLEM)
algorithm work. The numerical issue of the VNLEM is improved by taking the
orientation feature in the commonly applied scale-invariant feature transform
(SIFT), and a theoretical analysis of the robustness of the orientation feature
in the SIFT is provided. The VNLEM is applied to an image database of 1,361
images and compared with the NLEM. Different image quality assessments based on
the error-sensitivity or the human visual system are applied to evaluate the
performance. The results confirmed the potential of the VNLEM algorithm.


title:
Dynamics of semi-superfluid fluxtubes in color-flavor locked quark
  matter

abstract:
  At very high densities, as for example in the core of a neutron star, matter
may appear in the color-flavor locked (CFL) phase, which is a superfluid. This
phase features topologically stable vortex solutions, which arise in a spinning
superfluid as localized configurations carrying quanta of angular momentum.
Despite the topological stability of these vortices they are not the lowest
energy state of the system at neutron star densities and decay into triplets of
semi-superfluid fluxtubes. In these proceedings we report on the progress of
our numerical study in the Ginzburg-Landau approach, where we investigate
lattices of semi-superfluid fluxtubes. The fluxtubes are obtained through
controlled decay of global vortex configurations in the presence of a gauge
field. Understanding the dynamics of semi-superfluid string configurations is
important in the context of angular momentum transfer from a quark matter core
of a neutron star beyond the core boundary, since not vortex-, but fluxtube
pinning seems to be the relevant mechanism in this scenario.


title: Dynamical and Reversible Control of Topological Spin Textures

abstract:
  Recent observations of topological spin textures brought spintronics one step
closer to new magnetic memories. Nevertheless, the existence of Skyrmions, as
well as their stabilization, require very specific intrinsic magnetic
properties which are usually fixed in magnets. Here we address the possibility
to dynamically control their intrinsic magnetic interactions by varying the
strength of a high-frequency laser field. It is shown that drastic changes can
be induced in the antiferromagnetic exchange interactions and the latter can
even be reversed to become ferromagnetic, provided the direct exchange is
already non-negligible in equilibrium as predicted, for example, in Si doped
with C, Sn, or Pb adatoms. In the presence of Dzyaloshinskii-Moriya
interactions, this enables us to tune features of ferromagnetic Skyrmions such
as their radius, making them easier to stabilize. Alternatively, such
topological spin textures can occur in frustrated triangular lattices. Then, we
demonstrate that a high-frequency laser field can induce dynamical frustration
in antiferromagnets, where the degree of frustration can subsequently be tuned
suitably to drive the material toward a Skyrmionic phase.


title:
Fame and Obsolescence: Disentangling growth and ageing dynamics of
  patent citations

abstract:
  We present an analysis of citations accrued over time by patents granted by
the United States Patent and Trademark Office in 1998. In contrast to previous
studies, a disaggregation by technology category is performed, and exogenously
caused citation-number growth is controlled for. Our approach reveals an
intrinsic citation rate that clearly separates into an -- in the long run,
exponentially time-dependent -- ageing function and a completely
time-independent preferential-attachment-type growth kernel. For the general
case of such a separable citation rate, we obtain the time-dependent citation
distribution analytically in a form that is valid for any functional form of
its ageing and growth parts. Good agreement between theory and long-time
characteristics of patent-citation data establishes our work as a useful
framework for addressing still open questions about knowledge-propagation
dynamics, such as the observed excess of citations at short times.


title: Evolving black holes from conformal transformations of static solutions

abstract:
  A class of nonstationary spacetimes is obtained by means of a conformal
transformation of the Schwarzschild metric, where the conformal factor $a(t)$
is an arbitrary function of the time coordinate only. We investigate several
situations including some where the final state is a central object with
constant mass. The metric is such that there is an initial big-bang type
singularity and the final state depends on the chosen conformal factor. The
Misner-Sharp mass is computed and a localized central object may be identified.
The trapping horizons, geodesic and causal structure of the resulting
spacetimes are investigated in detail. When $a(t)$ asymptotes to a constant in
a short enough time scale, the spacetime presents an event horizon and its
analytical extension reveals black-hole or white-hole regions. On the other
hand, when $a(t)$ is unbounded from above as in cosmological models, the
spacetime presents no event horizons and may present null singularities in the
future. The energy-momentum content and other properties of the respective
spacetimes are also investigated.


title:
Estimation of Stopped Protons at Energies Relevant for a Beam Energy
  Scan at the BNL Relativistic Heavy-Ion Collider

abstract:
  The recent net-proton fluctuation results of the STAR (Solenoidal Tracker At
RHIC) experiment from beam energy scan (BES) program at the BNL Relativistic
Heavy Ion Collider (RHIC) have drawn much attention to exploring the QCD
critical point and the nature of deconfinement phase transition. There has been
much speculation that the non-monotonic behavior of $\kappa\sigma^{2}$ of the
produced protons around $\sqrt{s_{\rm NN}}$ = 19.6 GeV in the STAR results may
be due to the existence of QCD critical point. However, the experimentally
measured proton distributions contain protons from heavy resonance decays, from
baryon stopping and from direct production processes. These proton
distributions are used to estimate the net-proton number fluctuation. Because
it is difficult to disentangle the protons from the above-mentioned sources, it
is better to devise a method which will account for the directly produced
baryons (protons) to study the dynamical fluctuation at different
center-of-mass energies. This is because, it is assumed that any associated
criticality in the system could affect the particle production mechanism and
hence the dynamical fluctuation in various conserved numbers. In the present
work, we demonstrate a method to estimate the number of stopped protons at RHIC
BES energies for central $0-5\%$ \auau collisions within STAR acceptance and
discuss its implications on the net-proton fluctuation results.


title: LHC Forward Physics

abstract:
  The goal of this report is to give a comprehensive overview of the rich field
of forward physics, with a special attention to the topics that can be studied
at the LHC. The report starts presenting a selection of the Monte Carlo
simulation tools currently available, chapter 2, then enters the rich
phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer,
while the unique scattering conditions of central exclusive production are
analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy
Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is
dedicated to the BFKL dynamics, multiparton interactions, and saturation. The
report ends with an overview of the forward detectors at LHC. Each chapter is
correlated with a comprehensive bibliography, attempting to provide to the
interested reader with a wide opportunity for further studies.


title: Neural stochastic codes, encoding and decoding

abstract:
  Understanding brain function, constructing computational models and
engineering neural prosthetics require assessing two problems, namely encoding
and decoding, but their relation remains controversial. For decades, the
encoding problem has been shown to provide insight into the decoding problem,
for example, by upper bounding the decoded information. However, here we show
that this need not be the case when studying response aspects beyond noise
correlations, and trace back the actual causes of this major departure from
traditional views. To that end, we reformulate the encoding and decoding
problems from the observer or organism perspective. In addition, we study the
role of spike-time precision and response discrimination, among other response
aspects, using stochastic transformations of the neural responses, here called
stochastic codes. Our results show that stochastic codes may cause different
information losses when used to describe neural responses and when employed to
train optimal decoders. Therefore, we conclude that response aspects beyond
noise correlations may play different roles in encoding and decoding. In
practice, our results show for the first time that decoders constructed
low-quality descriptions of response aspects may operate optimally on
high-quality descriptions and vice versa, thereby potentially yielding
experimental and computational savings, as well as new opportunities for
simplifying the design of computational brain models and neural prosthetics.


title:
Label-free single molecule imaging with numerical aperture-shaped
  interferometric scattering microscopy

abstract:
  Our ability to optically interrogate nanoscopic objects is controlled by the
difference between their extinction cross sections and the diffraction limited
area to which light can be confined in the far field. We show that a partially
transmissive spatial mask placed near the back focal plane of a high numerical
aperture microscope objective enhances the extinction contrast of a scatterer
near an interface by approximately $T^{-1/2}$, where T is the transmissivity of
the mask. Numerical aperture based differentiation of background from scattered
light represents a general approach to increasing extinction contrast and
enables routine label free imaging down to the single molecule level.


title:
Benchmarking inverse statistical approaches for protein structure and
  design with exactly solvable models

abstract:
  Inverse statistical approaches to determine protein structure and function
from Multiple Sequence Alignments (MSA) are emerging as powerful tools in
computational biology. However the underlying assumptions of the relationship
between the inferred effective Potts Hamiltonian and real protein structure and
energetics remain untested so far. Here we use lattice protein model (LP) to
benchmark those inverse statistical approaches. We build MSA of highly stable
sequences in target LP structures, and infer the effective pairwise Potts
Hamiltonians from those MSA. We find that inferred Potts Hamiltonians reproduce
many important aspects of 'true' LP structures and energetics. Careful analysis
reveals that effective pairwise couplings in inferred Potts Hamiltonians depend
not only on the energetics of the native structure but also on competing folds;
in particular, the coupling values reflect both positive design (stabilization
of native conformation) and negative design (destabilization of competing
folds). In addition to providing detailed structural information, the inferred
Potts models used as protein Hamiltonian for design of new sequences are able
to generate with high probability completely new sequences with the desired
folds, which is not possible using independent-site models. Those are
remarkable results as the effective LP Hamiltonians used to generate MSA are
not simple pairwise models due to the competition between the folds. Our
findings elucidate the reasons for the success of inverse approaches to the
modelling of proteins from sequence data, and their limitations.

categories: q-bio.BM cond-mat.stat-mech physics.bio-ph q-bio.QM


title: Probabilistic Failure Analysis in Model Validation & Verification

abstract:
  Automated fault localization is an important issue in model validation and
verification. It helps the end users in analyzing the origin of failure. In
this work, we show the early experiments with probabilistic analysis approaches
in fault localization. Inspired by the Kullback-Leibler Divergence from
Bayesian probabilistic theory, we propose a suspiciousness factor to compute
the fault contribution for the transitions in the reachability graph of model
checking, using which to rank the potential faulty transitions. To
automatically locate design faults in the simulation model of detailed design,
we propose to use the statistical model Hidden Markov Model (HMM), which
provides statistically identical information to component's real behavior. The
core of this method is a fault localization algorithm that gives out the set of
suspicious ranked faulty components and a backward algorithm that computes the
matching degree between the HMM and the simulation model to evaluate the
confidence degree of the localization conclusion.


title: Unpredictable solutions of differential equations

abstract:
  We apply the topology of convergence on compact sets to define unpredictable
functions [5, 6]. The topology is metrizable and easy for applications with
integral operators. To demonstrate the effectiveness of the approach, the
existence and uniqueness of the unpredictable solution for a delay differential
equation is proved. As a corollary of the theorem, a similar assertion for a
quasilinear ordinary differential equation is formulated. Examples with
simulations illustrate the obtained results.


title:
Topology of a dissipative spin: dynamical Chern number, bath induced
  non-adiabaticity and a quantum dynamo effect

abstract:
  We analyze the topological deformations of a spin-1/2 in an effective
magnetic field induced by an ohmic quantum dissipative environment at zero
temperature. From Bethe Ansatz results and a variational approach, we confirm
that the Chern number is preserved in the delocalized phase for $\alpha<1$. We
report a divergence of the Berry curvature at the equator when $\alpha_c=1$
that appears at the localization Kosterlitz-Thouless quantum phase transition
in this model. Recent experiments in quantum circuits have engineered
non-equilibrium protocols in time to access topological properties at
equilibrium from the measure of the (quasi-)adiabatic out-of-equilibrium spin
expectation values. Applying a numerically exact stochastic Schr\"{o}dinger
equation we find that, for a fixed sweep velocity, the bath induces a crossover
from (quasi-)adiabatic to non-adiabatic dynamical behavior when the spin bath
coupling increases. We also investigate the particular regime $H/\omega_c \ll
v/H \ll 1$, where the dynamical Chern number observable built from
out-of-equilibrium spin expectation values vanishes at $\alpha=1/2$. In this
regime, the mapping to an interacting resonance level model enables us to
characterize the evolution of the dynamical Chern number in the vicinity of
$\alpha=1/2$. Then, we provide an intuitive physical explanation of the
breakdown of adiabaticity in analogy to the Faraday effect in electromagnetism.
We demonstrate that the driving of the spin leads to the production of a large
number of bosonic excitations in the bath, which in return strongly affect the
spin dynamics. Finally, we quantify the spin-bath entanglement and build an
analogy with an effective model at thermal equilibrium.


title:
Hardness of Covering Alignment: Phase Transition in Post-Sequence
  Genomics

abstract:
  Covering alignment problems arise from recent developments in genomics; so
called pan-genome graphs are replacing reference genomes, and advances in
haplotyping enable full content of diploid genomes to be used as basis of
sequence analysis. In this paper, we show that the computational complexity
will change for natural extensions of alignments to pan-genome representations
and to diploid genomes. More broadly, our approach can also be seen as a
minimal extension of sequence alignment to labelled directed acyclic graphs
(labeled DAGs). Namely, we show that finding a \emph{covering alignment} of two
labeled DAGs is NP-hard even on binary alphabets. A covering alignment asks for
two paths $R_1$ (red) and $G_1$ (green) in DAG $D_1$ and two paths $R_2$ (red)
and $G_2$ (green) in DAG $D_2$ that cover the nodes of the graphs and maximize
the sum of the global alignment scores:
$\mathsf{as}(\mathsf{sp}(R_1),\mathsf{sp}(R_2))+\mathsf{as}(\mathsf{sp}(G_1),\mathsf{sp}(G_2))$,
where $\mathsf{sp}(P)$ is the concatenation of labels on the path $P$.
Pair-wise alignment of haplotype sequences forming a diploid chromosome can be
converted to a two-path coverable labelled DAG, and then the covering alignment
models the similarity of two diploids over arbitrary recombinations. We also
give a reduction to the other direction, to show that such a
recombination-oblivious diploid alignment is NP-hard on alphabets of size $3$.


title:
Software-defined and Virtualized Cellular Networks with M2M
  Communications

abstract:
  Machine-to-machine (M2M) communications have attracted great attention from
both academia and industry. In this paper, with recent advances in wireless
network virtualization and software-defined networking (SDN), we propose a
novel framework for M2M communications in software-defined cellular networks
with wireless network virtualization. In the proposed framework, according to
different functions and quality of service (QoS) requirements of machine-type
communication devices (MTCDs), a hypervisor enables the virtualization of the
physical M2M network, which is abstracted and sliced into multiple virtual M2M
networks. Moreover, we formulate a decision-theoretic approach to optimize the
random access process of M2M communications. In addition, we develop a feedback
and control loop to dynamically adjust the number of resource blocks (RBs) that
are used in the random access phase in a virtual M2M network by the SDN
controller. Extensive simulation results with different system parameters are
presented to show the performance of the proposed scheme.


title: Learning a Deep Embedding Model for Zero-Shot Learning

abstract:
  Zero-shot learning (ZSL) models rely on learning a joint embedding space
where both textual/semantic description of object classes and visual
representation of object images can be projected to for nearest neighbour
search. Despite the success of deep neural networks that learn an end-to-end
model between text and images in other vision problems such as image
captioning, very few deep ZSL model exists and they show little advantage over
ZSL models that utilise deep feature representations but do not learn an
end-to-end embedding. In this paper we argue that the key to make deep ZSL
models succeed is to choose the right embedding space. Instead of embedding
into a semantic space or an intermediate space, we propose to use the visual
space as the embedding space. This is because that in this space, the
subsequent nearest neighbour search would suffer much less from the hubness
problem and thus become more effective. This model design also provides a
natural mechanism for multiple semantic modalities (e.g., attributes and
sentence descriptions) to be fused and optimised jointly in an end-to-end
manner. Extensive experiments on four benchmarks show that our model
significantly outperforms the existing models. Code is available at
https://github.com/lzrobots/DeepEmbeddingModel_ZSL


title:
Entangled two photon absorption cross section on the 808 nm region for
  the common dyes Zinc tetraphenylporphyrin and Rhodamine B

abstract:
  We report the measurement of the entangled two photon absorption cross
section, $\sigma_E$, at 808 nm on organic chromophores in solution in a low
photon flux regime. We performed measurements on Zinc tetraphenylporphyrin
(ZnTPP) in Toluene and Rhodamine B (RhB) in Methanol. This is, to the best of
our knowledge, the first time that $\sigma_E$ is measured for RhB.
Additionally, we report a systematic study of the dependence of $\sigma_E$ on
the molecular concentration for both molecular systems. In contrast to previous
experiments, our measurements are based on detecting the pairs of photons that
are transmitted by the molecular system. By using a coincidence count circuit
it was possible to improve the signal to noise ratio. This type of work is
important for the development of spectroscopic and microscopic techniques using
entangled photons.


title: Ergodicity of one-dimensional systems coupled to the logistic thermostat

abstract:
  We analyze the ergodicity of three one-dimensional Hamiltonian systems, with
harmonic, quartic and Mexican-hat potentials, coupled to the logistic
thermostat. As criteria for ergodicity we employ: the independence of the
Lyapunov spectrum with respect to initial conditions; the absence of visual
"holes" in two-dimensional Poincar\'e sections; the agreement between the
histograms in each variable and the theoretical marginal distributions; and the
convergence of the global joint distribution to the theoretical one, as
measured by the Hellinger distance. Taking a large number of random initial
conditions, for certain parameter values of the thermostat we find no
indication of regular trajectories and show that the time distribution
converges to the ensemble one for an arbitrarily long trajectory for all the
systems considered. Our results thus provide a robust numerical indication that
the logistic thermostat can serve as a single one-parameter thermostat for
stiff one-dimensional systems.


title: NLO predictions for SMEFT in the top-quark sector

abstract:
  Predictions for the Standard Model Effective Field Theory at the
next-to-leading order accuracy in QCD, including parton-shower effects, have
started to become available in the MadGraph5_aMC@NLO framework. In this talk we
summarize some recent results for $t\bar t$, single top, $t\bar tZ/\gamma$, and
$t\bar tH$ production channels at dimension six.


title:
Partitioning Strategies and Task Allocation for Target-tracking with
  Multiple Guards in Polygonal Environments

abstract:
  This paper presents an algorithm to deploy a team of {\it free} guards
equipped with omni-directional cameras for tracking a bounded speed intruder
inside a simply-connected polygonal environment. The proposed algorithm
partitions the environment into smaller polygons, and assigns a guard to each
partition so that the intruder is visible to at least one guard at all times.
Based on the concept of {\it dynamic zones} introduced in this paper, we
propose event-triggered strategies for the guards to track the intruder. We
show that the number of guards deployed by the algorithm for tracking is
strictly less than $\lfloor {\frac{n}{3}} \rfloor$ which is sufficient and
sometimes necessary for coverage. We derive an upper bound on the speed of the
mobile guard required for successful tracking which depends on the intruder's
speed, the road map of the mobile guards, and geometry of the environment.
Finally, we extend the aforementioned analysis to orthogonal polygons, and show
that the upper bound on the number of guards deployed for tracking is strictly
less than $\lfloor {\frac{n}{4}} \rfloor$ which is sufficient and sometimes
necessary for the coverage problem.


title: Condensate of excitations in moving superfluids

abstract:
  A possibility of the condensation of excitations with a non-zero momentum in
rectilinearly moving and rotating superfluid bosonic and fermionic (with Cooper
pairing) media is considered in terms of a phenomenological order-parameter
functional at zero and non-zero temperature. The results might be applicable to
the description of bosonic systems like superfluid $^4$He, ultracold atomic
Bose gases, charged pion and kaon condensates in rotating neutron stars, and
various superconducting fermionic systems with pairing, like proton and
color-superconducting components in compact stars, metallic superconductors,
and neutral fermionic systems with pairing, like the neutron component in
compact stars and ultracold atomic Fermi gases. Order parameters of the
"mother" condensate in the superfluid and the new condensate of excitations,
corresponding energy gains, critical temperatures and critical velocities are
found.


title: Higher-orders in heavy quark processes within the LTD approach

abstract:
  The computation of perturbative corrections to processes involving heavy
quarks is crucial for the precision program of the LHC and future colliders. In
this article, we describe a powerful approach to calculate higher-orders in QCD
skipping the traditional subtraction method. Our proposal is based on the
loop-tree duality (LTD) theorem, which allows to rewrite virtual contributions
in terms of integrals over the real emission phase-space. Then, we proceed to
combine both real and virtual contributions at the integrand level, obtaining
regular expressions that can be numerically integrated in four space-time
dimensions. In this way, we avoid dealing with complicated massive Feynman
integrals and introducing infrared counter-terms. Some reference examples are
explained, in order to exhibit the potential of our method.


title: Learning Dexterous Manipulation Policies from Experience and Imitation

abstract:
  We explore learning-based approaches for feedback control of a dexterous
five-finger hand performing non-prehensile manipulation. First, we learn local
controllers that are able to perform the task starting at a predefined initial
state. These controllers are constructed using trajectory optimization with
respect to locally-linear time-varying models learned directly from sensor
data. In some cases, we initialize the optimizer with human demonstrations
collected via teleoperation in a virtual environment. We demonstrate that such
controllers can perform the task robustly, both in simulation and on the
physical platform, for a limited range of initial conditions around the trained
starting state. We then consider two interpolation methods for generalizing to
a wider range of initial conditions: deep learning, and nearest neighbors. We
find that nearest neighbors achieve higher performance. Nevertheless, the
neural network has its advantages: it uses only tactile and proprioceptive
feedback but no visual feedback about the object (i.e. it performs the task
blind) and learns a time-invariant policy. In contrast, the nearest neighbors
method switches between time-varying local controllers based on the proximity
of initial object states sensed via motion capture. While both generalization
methods leave room for improvement, our work shows that (i) local
trajectory-based controllers for complex non-prehensile manipulation tasks can
be constructed from surprisingly small amounts of training data, and (ii)
collections of such controllers can be interpolated to form more global
controllers. Results are summarized in the supplementary video:
https://youtu.be/E0wmO6deqjo


title:
Analysis and approximation of a fractional Laplacian-based closure model
  for turbulent flows and its connection to Richardson pair dispersion

abstract:
  We study a turbulence closure model in which the fractional Laplacian
$(-\Delta)^\alpha$ of the velocity field represents the turbulence diffusivity.
We investigate the energy spectrum of the model by applying Pao's energy
transfer theory. For the case $\alpha=1/3$, the corresponding power law of the
energy spectrum in the inertial range has a correction exponent on the regular
Kolmogorov -5/3 scaling exponent. For this case, this model represents
Richardson's particle pair-distance superdiffusion of a fully developed
homogeneous turbulent flow as well as L\'evy jumps that lead to the
superdiffusion. For other values of $\alpha$, the power law of the energy
spectrum is consistent with the regular Kolmogorov -5/3 scaling exponent. We
also propose and study a modular time-stepping algorithm in semi-discretized
form. The algorithm is minimally intrusive to a given legacy code for solving
Navier-Stokes equations by decoupling the local part and nonlocal part of the
equations for the unknowns. We prove the algorithm is unconditionally stable
and unconditionally, first-order convergent. We also derive error estimates for
full discretizations of the model which, in addition to the time stepping
algorithm, involves a finite element spatial discretization and a domain
truncation approximation to the range of the fractional Laplacian.


title:
Convergence of Adaptive Mixed Finite Element Methods for the Hodge
  Laplacian Equation: without harmonic forms

abstract:
  Finite element exterior calculus (FEEC) has been developed as a systematical
framework for constructing and analyzing stable and accurate numerical method
for partial differential equations by employing differential complexes. This
paper is devoted to analyze convergence of adaptive mixed finite element
methods for Hodge Laplacian equations based on FEEC without considering
harmonic forms. More precisely, a residual type posteriori error estimates is
obtained by using the Hodge decomposition, the regular decomposition and
bounded commuting quasi-interpolants. An additional marking strategy is added
to ensure the quasi-orthogonality. Using this quasi-orthogonality, the uniform
convergence of adaptive mixed finite element methods is obtained without
assuming the initial mesh size is small enough.


title: Soliton repetition rate in a silicon-nitride microresonator

abstract:
  The repetition rate of a Kerr comb comprising a single soliton in an
anomalous dispersion silicon nitride microcavity is measured as a function of
pump frequency tuning. The contributions from the Raman soliton self-frequency
shift (SSFS) and from thermal effects are evaluated both experimentally and
theoretically; the SSFS is found to dominate the changes in repetition rate.
The relationship between the changes in repetition rate and pump frequency
detuning is found to be independent of the nonlinearity coefficient and
dispersion of the cavity. Modeling of the repetition rate change by using the
generalized Lugiato-Lefever equation is discussed; the Kerr shock is found to
have only a minor effect on repetition rate for cavity solitons with duration
down to ~50 fs.


title:
Counterexamples on Jumarie's three basic fractional calculus formulae
  for non-differentiable continuous functions

abstract:
  In the present paper, we provide five counterexamples to show directly the
Jumarie's formulae are not true for non-differentiable continuous functions.


title:
Influence of awareness that results from direct experience on the spread
  of epidemics

abstract:
  Here we study ODE epidemic models with spread of awareness, assuming that a
certain proportion of the hosts will become aware of the ongoing outbreak upon
recovery. This study builds on W. Just and J. Saldana's work in [1], and is
conducted under the same framework, while addressing the influence of the
awareness gained from direct experience of the disease.
  In [1], the authors investigated the question whether preventive behavioral
response triggered by awareness of the infection is sufficient to prevent
future flare-ups from low endemic levels if awareness decays over time. They
showed that if all the hosts experienced infection return directly to the
susceptible compartment upon recovery, such oscillations are ruled out in
Susceptible-Aware-Infectious Susceptible models with a single compartment of
aware hosts, but can occur if two distinct compartments of aware hosts who
differ in their willingness to alert other susceptible hosts are considered.
Qualitatively, the models studied here produce the same results when we assume
that recovery from the disease may or even will convey awareness from direct
experience.


title: Efficient Parallel Verification of Galois Field Multipliers

abstract:
  Galois field (GF) arithmetic is used to implement critical arithmetic
components in communication and security-related hardware, and verification of
such components is of prime importance. Current techniques for formally
verifying such components are based on computer algebra methods that proved
successful in verification of integer arithmetic circuits. However, these
methods are sequential in nature and do not offer any parallelism. This paper
presents an algebraic functional verification technique of gate-level GF (2m )
multipliers, in which verification is performed in bit-parallel fashion. The
method is based on extracting a unique polynomial in Galois field of each
output bit independently. We demonstrate that this method is able to verify an
n-bit GF multiplier in n threads. Experiments performed on pre- and
post-synthesized Mastrovito and Montgomery multipliers show high efficiency up
to 571 bits.


title: Interaction of Airy-Gaussian beams in defected photonic lattices

abstract:
  We investigate interactions by means of direct numerical simulations between
two finite Airy-Gaussian (AiG) beams in different media with the defected
photonic lattices in one transverse dimension. We discuss different lattice
structures in which the beams with different intensities and phases are
launched into the medium, but accelerate in opposite directions. During
interactions we see the interference fringe, breathers and soliton pairs
generated that are not accelerating. In the linear media, the initial
deflection direction of the accelerated beams is changed by adjusting the phase
shift and the beam interval. For a certain lattice period, the periodic
interference fringe can form. A constructive or destructive interference can
vary with the defect depth and phase shift. While the nonlinearity is
introduced, the breathers is generated. Especially, the appropriate beam
amplitude and lattice depth may lead to the formation of soliton pairs.


title:
Congruence subgroups from representations of the three-strand braid
  group

abstract:
  Ng and Schauenburg proved that the kernel of a $(2+1)$-dimensional
topological quantum field theory representation of $\mathrm{SL}(2, \mathbb{Z})$
is a congruence subgroup. Motivated by their result, we explore when the kernel
of an irreducible representation of the braid group $B_3$ with finite image
enjoys a congruence subgroup property. In particular, we show that in
dimensions two and three, when the projective order of the image of the braid
generator $\sigma_1$ is between 2 and 5 the kernel projects onto a congruence
subgroup of $\mathrm{PSL}(2,\mathbb{Z})$ and compute its level. However, we
prove for three dimensional representations, the projective order is not enough
to decide the congruence property. For each integer of the form $2\ell \geq 6$
with $\ell$ odd, we construct a pair of non-congruence subgroups associated
with three-dimensional representations having finite image and $\sigma_1$
mapping to a matrix with projective order $2\ell$. Our technique uses
classification results of low dimensional braid group representations, and the
Fricke-Wohlfarht theorem in number theory.


title:
A Way out of the Odyssey: Analyzing and Combining Recent Insights for
  LSTMs

abstract:
  LSTMs have become a basic building block for many deep NLP models. In recent
years, many improvements and variations have been proposed for deep sequence
models in general, and LSTMs in particular. We propose and analyze a series of
augmentations and modifications to LSTM networks resulting in improved
performance for text classification datasets. We observe compounding
improvements on traditional LSTMs using Monte Carlo test-time model averaging,
average pooling, and residual connections, along with four other suggested
modifications. Our analysis provides a simple, reliable, and high quality
baseline model.


title: Well-Typed Languages are Sound

abstract:
  Type soundness is an important property of modern programming languages. In
this paper we explore the idea that "well-typed languages are sound": the idea
that the appropriate typing discipline over language specifications guarantees
that the language is type sound. We instantiate this idea for a certain class
of languages defined using small step operational semantics by ensuring the
progress and preservation theorems. Our first contribution is a syntactic
discipline for organizing and restricting language specifications so that they
automatically satisfy the progress theorem. This discipline is not novel but
makes explicit the way expert language designers have been organizing a certain
class of languages for long time. We give a formal account of this discipline
by representing language specifications as (higher-order) logic programs and by
giving a meta type system over that collection of formulas. Our second
contribution is a methodology and meta type system for guaranteeing that
languages satisfy the preservation theorem. Ultimately, we proved that language
specifications that conform to our meta type systems are guaranteed to be type
sound. We have implemented these ideas in the TypeSoundnessCertifier, a tool
that takes language specifications in the form of logic programs and type
checks them according to our meta type systems. For those languages that pass
our type checker, our tool automatically produces a proof of type soundness
that can be machine-checked by the Abella proof assistant. For those languages
that fail our type checker, the tool pinpoints the design mistakes that hinder
type soundness. We have applied the TypeSoundnessCertifier to a large number of
programming languages, including those with recursive types, polymorphism,
letrec, exceptions, lists and other common types and operators.


title:
Predicting the Amplitude and Hemispheric Asymmetry of Solar Cycle 25
  with Surface Flux Transport

abstract:
  Evidence strongly indicates that the strength of the Sun's polar fields near
the time of a sunspot cycle minimum determines the strength of the following
solar activity cycle. We use our Advective Flux Transport (AFT) code, with
flows well constrained by observations, to simulate the evolution of the Sun's
polar magnetic fields from early 2016 to the end of 2019 --- near the expected
time of Cycle 24/25 minimum. We run a series of simulations in which the
uncertain conditions (convective motion details, active region tilt, and
meridional flow profile) are varied within expected ranges. We find that the
average strength of the polar fields near the end of Cycle 24 will be similar
to that measured near the end of Cycle 23, indicating that Cycle 25 will be
similar in strength to the current cycle. In all cases the polar fields are
asymmetric with fields in the south stronger than those in the north. This
asymmetry would be more pronounced if not for the predicted weakening of the
southern polar fields in late 2016 and through 2017. After just four years of
simulation the variability across our ensemble indicates an accumulated
uncertainty of about 15\%. This accumulated uncertainty arises from stochastic
variations in the convective motion details, the active region tilt, and
changes in the meridional flow profile. These variations limit the ultimate
predictability of the solar cycle.


title:
Rearrangement of valence neutrons in the neutrinoless double-$\beta$
  decay of $^{136}$Xe

abstract:
  A quantitative description of the change in ground-state neutron occupancies
between $^{136}$Xe and $^{136}$Ba, the initial and final state in the
neutrinoless double-$\beta$ decay of $^{136}$Xe, has been extracted from
precision measurements of the cross sections of single-neutron adding and
-removing reactions. Comparisons are made to recent theoretical calculations of
the same properties using various nuclear-structure models. These are the same
calculations used to determine the magnitude of the nuclear matrix elements for
the process, which at present disagree with each other by factors of 2 or 3.
The experimental neutron occupancies show some disagreement with the
theoretical calculations.


title: Weak log majorization and determinantal inequalities

abstract:
  Denote by $\P_n$ the set of $n\times n$ positive definite matrices. Let $D =
D_1\oplus \dots \oplus D_k$, where $D_1\in \P_{n_1}, \dots, D_k \in \P_{n_k}$
with $n_1+\cdots + n_k=n$. Partition $C\in \P_n$ according to $(n_1, \dots,
n_k)$ so that $\Diag C = C_1\oplus \dots \oplus C_k$. We prove the following
weak log majorization result: \begin{equation*} \lambda (C^{-1}_1D_1\oplus
\cdots \oplus C^{-1}_kD_k)\prec_{w \,\log} \lambda(C^{-1}D), \end{equation*}
where $\lambda(A)$ denotes the vector of eigenvalues of $A\in \Cnn$. The
inequality does not hold if one replaces the vectors of eigenvalues by the
vectors of singular values, i.e., \begin{equation*} s(C^{-1}_1D_1\oplus \cdots
\oplus C^{-1}_kD_k)\prec_{w \,\log} s(C^{-1}D) \end{equation*} is not true. As
an application, we provide a generalization of a determinantal inequality of
Matic \cite[Theorem 1.1]{M}. In addition, we obtain a weak majorization result
which is complementary to a determinantal inequality of Choi \cite[Theorem
2]{C} and give a weak log majorization open question.


title: Low-rank Bilinear Pooling for Fine-Grained Classification

abstract:
  Pooling second-order local feature statistics to form a high-dimensional
bilinear feature has been shown to achieve state-of-the-art performance on a
variety of fine-grained classification tasks. To address the computational
demands of high feature dimensionality, we propose to represent the covariance
features as a matrix and apply a low-rank bilinear classifier. The resulting
classifier can be evaluated without explicitly computing the bilinear feature
map which allows for a large reduction in the compute time as well as
decreasing the effective number of parameters to be learned.
  To further compress the model, we propose classifier co-decomposition that
factorizes the collection of bilinear classifiers into a common factor and
compact per-class terms. The co-decomposition idea can be deployed through two
convolutional layers and trained in an end-to-end architecture. We suggest a
simple yet effective initialization that avoids explicitly first training and
factorizing the larger bilinear classifiers. Through extensive experiments, we
show that our model achieves state-of-the-art performance on several public
datasets for fine-grained classification trained with only category labels.
Importantly, our final model is an order of magnitude smaller than the recently
proposed compact bilinear model, and three orders smaller than the standard
bilinear CNN model.


title: Perpendicular magnetic anisotropy in Co$_2$MnGa

abstract:
  We report perpendicular magnetic anisotropy in the ferromagnetic Heusler
alloy Co$_2$MnGa in a MgO/Co$_2$MnGa/Pd trilayer stack for Co$_2$MnGa
thicknesses up to 3.5 nm. There is a thickness- and temperature-dependent spin
reorientation transition from perpendicular to in-plane magnetic anisotropy
which we study through the anomalous Hall effect. From the temperature
dependence of the anomalous Hall effect, we observe the expected scaling of
$\rho_{xy}^{AHE}$ with $\rho_{xx}$, suggesting the intrinsic and side-jump
mechanisms are largely responsible for the anomalous Hall effect in this
material.


title: Calculating algebraic entropies: an express method

abstract:
  We describe a method for investigating the integrable character of a given
three-point mapping, provided that the mapping has confined singularities. Our
method, dubbed "express", is inspired by a novel approach recently proposed by
R.G. Halburd. While the latter aims at computing the exact degree growth of a
given mapping based on the structure of its singularities, we content ourselves
with obtaining an answer as to whether a given system is integrable or not. We
present several examples illustrating our method as well as its limitations. We
also compare the present method to the full-deautonomisation approach we
recently introduced.


title:
Non-arithmetic ball quotients from a configuration of elliptic curves in
  an Abelian surface

abstract:
  We construct some non-arithmetic ball quotients as branched covers of a
quotient of an Abelian surface by a finite group, and compare them with
lattices that previously appear in the literature. This gives an alternative
construction, which is independent of the computer, of some lattices
constructed by the author with Parker and Paupert.


title:
Efficient Diffusion on Region Manifolds: Recovering Small Objects with
  Compact CNN Representations

abstract:
  Query expansion is a popular method to improve the quality of image retrieval
with both conventional and CNN representations. It has been so far limited to
global image similarity. This work focuses on diffusion, a mechanism that
captures the image manifold in the feature space. The diffusion is carried out
on descriptors of overlapping image regions rather than on a global image
descriptor like in previous approaches. An efficient off-line stage allows
optional reduction in the number of stored regions. In the on-line stage, the
proposed handling of unseen queries in the indexing stage removes additional
computation to adjust the precomputed data. We perform diffusion through a
sparse linear system solver, yielding practical query times well below one
second. Experimentally, we observe a significant boost in performance of image
retrieval with compact CNN descriptors on standard benchmarks, especially when
the query object covers only a small part of the image. Small objects have been
a common failure case of CNN-based retrieval.


title: Direct measurement of the critical pore size in a model membrane

abstract:
  We study pore nucleation in a model membrane system, a freestanding polymer
film. Nucleated pores smaller than a critical size close, while pores larger
than the critical size grow. Holes of varying size were purposefully prepared
in liquid polymer films, and their evolution in time was monitored using
optical and atomic force microscopy to extract a critical radius. The critical
radius scales linearly with film thickness for a homopolymer film. The results
agree with a simple model which takes into account the energy cost due to
surface area at the edge of the pore. The energy cost at the edge of the pore
is experimentally varied by using a lamellar-forming diblock copolymer
membrane. The underlying molecular architecture causes increased frustration at
the pore edge resulting in an enhanced cost of pore formation.

categories: cond-mat.soft cond-mat.mes-hall cond-mat.mtrl-sci physics.flu-dyn


title:
Improper ferroelectricity in stuffed aluminate sodalites for
  pyroelectric energy harvesting

abstract:
  Ferroelectricity in stuffed aluminate sodalites is demonstrated in the
present study. The present results indicate that stuffed aluminate sodalites
exhibit excellent performance as a pyroelectric energy harvester, suggesting
that they exhibit great promise as a class of materials for highly efficient
energy harvesting devices. (See manuscript for the full abstract)


title:
Intrinsic Enhancement of Dielectric Permittivity in (Nb + In) co-doped
  TiO2 single crystals

abstract:
  The development of dielectric materials with colossal permittivity is
important for the miniaturization of electronic devices and fabrication of
high-density energy-storage devices. The electron-pinned defect-dipoles has
been recently proposed to boost the permittivity of (Nb + In) co-doped TiO2 to
105. However, the follow-up studies suggest an extrinsic contribution to the
colossal permittivity from thermally excited carriers. Herein, we demonstrate a
marked enhancement in the permittivity of (Nb + In) co-doped TiO2 single
crystals at sufficiently low temperatures such that the thermally excited
carriers are frozen out and exert no influence on the dielectric response. The
results indicate that the permittivity attains quadruple of that for pure TiO2.
This finding suggests that the electron-pinned defect-dipoles add an extra
dielectric response to that of the TiO2 host matrix. The results offer a novel
approach for the development of functional dielectric materials with large
permittivity by engineering complex defects into bulk materials.


title:
Estimation Theory Based Robust Phase Offset Estimation in the Presence
  of Delay Attacks

abstract:
  This paper addresses the problem of robust clock phase offset estimation for
the IEEE 1588 precision time protocol (PTP) in the presence of delay attacks.
Delay attacks are one of the most effective cyber attacks in PTP, as they
cannot be mitigated using typical security measures. In this paper, we consider
the case where the slave node can exchange synchronization messages with
multiple master nodes synchronized to the same clock. We first provide lower
bounds on the best achievable performance for any phase offset estimation
scheme in the presence of delay attacks. We then present a novel phase offset
estimation scheme that employs the Expectation-Maximization algorithm for
detecting which of the master-slave communication links have been subject to
delay attacks. After discarding information from the links identified as
attacked, which we show to be optimal, the optimal vector location parameter
estimator is employed to estimate the phase offset of the slave node.
Simulation results are presented to show that the proposed phase offset
estimation scheme exhibits performance close to the lower bounds in a wide
variety of scenarios.


title:
The Amazing Mysteries of the Gutter: Drawing Inferences Between Panels
  in Comic Book Narratives

abstract:
  Visual narrative is often a combination of explicit information and judicious
omissions, relying on the viewer to supply missing details. In comics, most
movements in time and space are hidden in the "gutters" between panels. To
follow the story, readers logically connect panels together by inferring unseen
actions through a process called "closure". While computers can now describe
what is explicitly depicted in natural images, in this paper we examine whether
they can understand the closure-driven narratives conveyed by stylized artwork
and dialogue in comic book panels. We construct a dataset, COMICS, that
consists of over 1.2 million panels (120 GB) paired with automatic textbox
transcriptions. An in-depth analysis of COMICS demonstrates that neither text
nor image alone can tell a comic book story, so a computer must understand both
modalities to keep up with the plot. We introduce three cloze-style tasks that
ask models to predict narrative and character-centric aspects of a panel given
n preceding panels as context. Various deep neural architectures underperform
human baselines on these tasks, suggesting that COMICS contains fundamental
challenges for both vision and language.


title: Pseudo-Anosov mapping classes from pure mapping classes

abstract:
  We study types of mapping classes which arise as a product of a given mapping
class and powers of certain pure mapping classes. We derive an explicit
constant depending only on a surface such that almost all above pure mapping
classes give rise to pseudo-Anosov type whenever their powers are larger than
the constant. Furthermore, the stable lengths of pseudo-Anosov mapping classes
obtained by this method are directly captured from the construction.


title: Prompt atmospheric neutrino flux

abstract:
  We evaluate the prompt atmospheric neutrino flux including nuclear correction
and $B$ hadron contribution in the different frameworks: NLO perturbative QCD
and dipole models. The nuclear effect is larger in the prompt neutrino flux
than in the total charm production cross section, and it reduces the fluxes by
$10\% - 30\%$ depending on the model. We also investigate the uncertainty using
the QCD scales allowed by the charm cross section data from RHIC and LHC
experiments.


title: How the relativistic motion affects Einstein-Podolsky-Rosen steering

abstract:
  In this Letter, the dynamic behavior of Einstein-Podolsky-Rosen (EPR)
steering and the redistribution of EPR steering under a relativistic framework
are investigated. Specifically, we explore the scenario that particle A hold by
Alice is in a flat space-time and another particle B by Bob entangled with A is
in a non-inertial framework. The results show that EPR steering from Alice to
Bob is dramatically destroyed by Unruh effect caused by the acceleration of
Bob. Besides, EPR steering has an asymmetry property, and EPR steering
asymmetry increases with the growing intensity of Unruh effect, implying that
the Unruh effect can bring on EPR steering asymmetry. Furthermore, the reduced
physical accessible EPR steering from Alice to Bob is distributed to the
physical inaccessible EPR steering (from Alice to anti-Bob or from Bob to
anti-Bob). Notably, unlike entanglement and quantum discord, only one of EPR
steering from Alice to anti-Bob and Bob to anti-Bob experiences a sudden birth
with the increase of acceleration parameter, which means that they cannot
simultaneously survive. That is, the monogamy relation of EPR steering is still
tenable in such a scenario. Consequently, we believe that EPR steering could
also be served as one of important information resources within the
long-distance quantum secure communication under the relativistic framework.


title:
Integrated Resource Management in Software Defined Networking, Caching
  and Computing

abstract:
  Recently, there are significant advances in the areas of networking, caching
and computing. Nevertheless, these three important areas have traditionally
been addressed separately in the existing research. In this paper, we present a
novel framework that integrates networking, caching and computing in a
systematic way and enables dynamic orchestration of these three resources to
improve the end-to-end system performance and meet the requirements of
different applications. Then, we consider the bandwidth, caching and computing
resource allocation issue and formulate it as a joint caching/computing
strategy and servers selection problem to minimize the combination cost of
network usage and energy consumption in the framework. To minimize the
combination cost of network usage and energy consumption in the framework, we
formulate it as a joint caching/computing strategy and servers selection
problem. In addition, we solve the joint caching/computing strategy and servers
selection problem using an exhaustive-search algorithm. Simulation results show
that our proposed framework significantly outperforms the traditional network
without in-network caching/computing in terms of network usage and energy
consumption.


title:
Constraints on Brane-World Inflation from the CMB Power Spectrum:
  Revisited

abstract:
  We analyze the Randal Sundrum brane-world inflation scenario in the context
of the latest CMB constraints from Planck. We summarize constraints on the most
popular classes of models and explore some more realistic inflaton effective
potentials. The constraint on standard inflationary parameters changes in the
brane-world scenario. We confirm that in general the brane-world scenario
increases the tensor-to-scalar ratio, thus making this paradigm less consistent
with the Planck constraints. Indeed, when the BICEP2/Keck constraints are
included, all monomial potentials in the brane-world scenario become disfavored
compared to the standard scenario. However, for natural inflation the
brane-world scenario fits the constraints better due to larger allowed values
of the number of e-foldings N before the end of inflation in the brane-world.


title:
Global solution for the $3D$ quadratic Schr\"odinger equation of $Q(u,
  \bar{u})$ type

abstract:
  We study a class of $3D$ quadratic Schr\"odinger equations as follows,
$(\partial_t -i \Delta) u = Q(u, \bar{u})$. Different from nonlinearities of
the $uu$ type and the $\bar{u}\bar{u}$ type, which have been studied by
Germain-Masmoudi-Shatah, the interaction of $u$ and $\bar{u}$ is very strong at
the low frequency part, e.g., $1\times 1 \rightarrow 0$ type interaction (the
size of input frequency is "$1$" and the size of output frequency is "$0$"). It
creates a growth mode for the Fourier transform of the profile of solution
around a small neighborhood of zero. This growth mode will again cause the
growth of profile in the medium frequency part due to the $1\times 0\rightarrow
1$ type interaction. The issue of strong $1\times 1\rightarrow 0$ type
interaction makes the global existence problem very delicate.
  In this paper, we show that, as long as there are "$\epsilon$" derivatives
inside the quadratic term $Q (u, \bar{u})$, there exists a global solution for
small initial data. As a byproduct, we also give a simple proof for the almost
global existence of the small data solution of $(\partial_t -i \Delta)u = |u|^2
= u\bar{u}$, which was first proved by Ginibre-Hayashi. Instead of using vector
fields, we consider this problem purely in Fourier space.


title: Learning To Score Olympic Events

abstract:
  Estimating action quality, the process of assigning a "score" to the
execution of an action, is crucial in areas such as sports and health care.
Unlike action recognition, which has millions of examples to learn from, the
action quality datasets that are currently available are small -- typically
comprised of only a few hundred samples. This work presents three frameworks
for evaluating Olympic sports which utilize spatiotemporal features learned
using 3D convolutional neural networks (C3D) and perform score regression with
i) SVR, ii) LSTM, and iii) LSTM followed by SVR. An efficient training
mechanism for the limited data scenarios is presented for clip-based training
with LSTM. The proposed systems show significant improvement over existing
quality assessment approaches on the task of predicting scores of Olympic
events {diving, vault, figure skating}. While the SVR-based frameworks yield
better results, LSTM-based frameworks are more natural for describing an action
and can be used for improvement feedback.


title: Localized Coulomb Descriptors for the Gaussian Approximation Potential

abstract:
  We introduce a novel class of localized atomic environment representations,
based upon the Coulomb matrix. By combining these functions with the Gaussian
approximation potential approach, we present LC-GAP, a new system for
generating atomic potentials through machine learning (ML). Tests on the QM7,
QM7b and GDB9 biomolecular datasets demonstrate that potentials created with
LC-GAP can successfully predict atomization energies for molecules larger than
those used for training to chemical accuracy, and can (in the case of QM7b)
also be used to predict a range of other atomic properties with accuracy in
line with the recent literature. As the best-performing representation has only
linear dimensionality in the number of atoms in a local atomic environment,
this represents an improvement both in prediction accuracy and computational
cost when considered against similar Coulomb matrix-based methods.


title:
Quantized Ballistic Transport of Electrons and Electron Pairs in
  LaAlO$_3$/SrTiO$_3$ Nanowires

abstract:
  SrTiO$_3$-based heterointerfaces support quasi-two-dimensional (2D) electron
systems that are analogous to III-V semiconductor heterostructures, but also
possess superconducting, magnetic, spintronic, ferroelectric, and ferroelastic
degrees of freedom. Despite these rich properties, the relatively low
mobilities of 2D complex-oxide interfaces appear to preclude ballistic
transport in 1D. Here we show that the 2D LaAlO$_3$/SrTiO$_3$ interface can
support quantized ballistic transport of electrons and (non-superconducting)
electron pairs within quasi-1D structures that are created using a
well-established conductive atomic-force microscope (c-AFM) lithography
technique. The nature of transport ranges from truly single-mode (1D) to
three-dimensional (3D), depending on the applied magnetic field and gate
voltage. Quantization of the lowest $e^2/h$ plateau indicate a ballistic
mean-free path $l_{MF}\sim$ 20 $\mu$m, more than two orders of magnitude larger
than for 2D LaAlO$_3$/SrTiO$_3$ heterostructures. Non-superconducting electron
pairs are found to be stable in magnetic fields as high as $B=11$ T, and
propagate ballistically with conductance quantized at 2$e^2/h$. Theories of
one-dimensional (1D) transport of interacting electron systems depend crucially
on the sign of the electron-electron interaction, which may help explain the
highly ballistic transport behavior. The 1D geometry yields new insights into
the electronic structure of the LaAlO$_3$/SrTiO$_3$ system and offers a new
platform for the study of strongly interacting 1D electronic systems.

categories: cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.str-el cond-mat.supr-con quant-ph


title:
Designing Energy-Efficient Convolutional Neural Networks using
  Energy-Aware Pruning

abstract:
  Deep convolutional neural networks (CNNs) are indispensable to
state-of-the-art computer vision algorithms. However, they are still rarely
deployed on battery-powered mobile devices, such as smartphones and wearable
gadgets, where vision algorithms can enable many revolutionary real-world
applications. The key limiting factor is the high energy consumption of CNN
processing due to its high computational complexity. While there are many
previous efforts that try to reduce the CNN model size or amount of
computation, we find that they do not necessarily result in lower energy
consumption, and therefore do not serve as a good metric for energy cost
estimation.
  To close the gap between CNN design and energy consumption optimization, we
propose an energy-aware pruning algorithm for CNNs that directly uses energy
consumption estimation of a CNN to guide the pruning process. The energy
estimation methodology uses parameters extrapolated from actual hardware
measurements that target realistic battery-powered system setups. The proposed
layer-by-layer pruning algorithm also prunes more aggressively than previously
proposed pruning methods by minimizing the error in output feature maps instead
of filter weights. For each layer, the weights are first pruned and then
locally fine-tuned with a closed-form least-square solution to quickly restore
the accuracy. After all layers are pruned, the entire network is further
globally fine-tuned using back-propagation. With the proposed pruning method,
the energy consumption of AlexNet and GoogLeNet are reduced by 3.7x and 1.6x,
respectively, with less than 1% top-5 accuracy loss. Finally, we show that
pruning the AlexNet with a reduced number of target classes can greatly
decrease the number of weights but the energy reduction is limited.
  Energy modeling tool and energy-aware pruned models available at
http://eyeriss.mit.edu/energy.html


title: An Adaptive Multiscale Approach for Electronic Structure Methods

abstract:
  In this paper, we introduce a new scheme for the efficient numerical
treatment of the electronic Schr\"odinger equation for molecules. It is based
on the combination of a many-body expansion, which corresponds to the so-called
bond order dissection Anova approach, with a hierarchy of basis sets of
increasing order. Here, the energy is represented as a finite sum of
contributions associated to subsets of nuclei and basis sets in a telescoping
sum like fashion. Under the assumption of data locality of the electronic
density (nearsightedness of electronic matter), the terms of this expansion
decay rapidly and higher terms may be neglected. We further extend the approach
in a dimension-adaptive fashion to generate quasi-optimal approximations, i.e.
a specific truncation of the hierarchical series such that the total benefit is
maximized for a fixed amount of costs. This way, we are able to achieve
substantial speed up factors compared to conventional first principles methods
depending on the molecular system under consideration. In particular, the
method can deal efficiently with molecular systems which include only a small
active part that needs to be described by accurate but expensive models.


title:
Pseudospectral bounds on transient growth for higher order and constant
  delay differential equations

abstract:
  Asymptotic dynamics of ordinary differential equations (ODEs) are commonly
understood by looking at eigenvalues of a matrix, and transient dynamics can be
bounded above and below by considering the corresponding pseudospectra. While
asymptotics for other classes of differential equations have been studied using
eigenvalues of a (nonlinear) matrix-valued function, there are no analogous
pseudospectral bounds on transient growth. In this paper, we propose extensions
of the pseudospectral results for ODEs first to higher order ODEs and then to
delay differential equations (DDEs) with constant delay. Results are
illustrated with a discretized partial delay differential equation and a model
of a semiconductor laser with phase-conjugate feedback.


title:
Enhanced toroidal flow stabilization of edge localized modes with
  increased plasma density

abstract:
  Toroidal flow alone is generally thought to have important influence on
tokamak edge pedestal stability, even though theory analysis often predicts
merely a weak stabilizing effect of toroidal flow on the edge localized modes
(ELMs) in experimental parameter regimes. For the first time, we find from
two-fluid MHD calculations that such a stabilization, however, can be
significantly enhanced by increasing the edge plasma density. Our finding
resolves a long-standing mystery whether or how toroidal rotation can indeed
have effective influence on ELMs, and explains why the ELM mitigation and
suppression by toroidal rotation are more favorably achieved in higher
collisionality regime in recent experiments. The finding suggests a new control
scheme on modulating toroidal flow stabilization of ELMs with plasma density,
along with a new additional constraint on the optimal level of plasma density
for the desired edge plasma conditions.