title:
Quantitative Determination of the Probability of Multiple-Motor
  Transport in Bead-Based Assays

abstract:
  With their longest dimension typically being less than 100 nm, molecular
motors are significantly below the optical-resolution limit. Despite
substantial advances in fluorescence-based imaging methodologies, labeling with
beads remains critical for optical-trapping-based investigations of molecular
motors. A key experimental challenge in bead-based assays is that the number of
motors on a bead is not well defined. Particularly for single-molecule
investigations, the probability of single versus multiple-motor events has not
been experimentally investigated. Here, we used bead travel distance as an
indicator of multiple-motor transport and determined the lower-bound
probability of bead transport by two or more motors. We limited the ATP
concentration to increase our detection sensitivity for multiple- versus
single-kinesin transport. Surprisingly, for all but the lowest motor number
examined, our measurements exceeded estimations of a previous model by R2-fold.
To bridge this apparent gap between theory and experiment, we derived a
closed-form expression for the probability of bead transport by multiple
motors, and constrained the only free parameter in this model using our
experimental measurements. Our data indicate that kinesin extends to ~57 nm
during bead transport, suggesting that kinesin exploits its conformational
flexibility to interact with microtubules at highly curved interfaces such as
those present for vesicle transport in cells. To our knowledge, our findings
provide the first experimentally constrained guide for estimating the
probability of multiple-motor transport in optical trapping studies. The
experimental approach utilized here (limiting ATP concentration) may be
generally applicable to studies in which molecular motors are labeled with
cargos that are artificial or are purified from cellular extracts.


title:
The attosecond regime of impulsive stimulated electronic Raman
  excitation

abstract:
  We have calculated the resonant and nonresonant contributions to attosecond
impulsive stimulated electronic Raman scattering (SERS) in regions of
autoionizing transitions. Comparison with Multiconfiguration Time-Dependent
Hartree-Fock (MCTDHF) calculations find that attosecond SERS is dominated by
continuum transitions and not autoionizing resonances. These results agree
quantitatively with a rate equation that includes second-order Raman and
first-and second-order photoionization rates. Such rate models can be extended
to larger molecular systems. Our results indicate that attosecond SERS
transition probabilities may be understood in terms of two-photon generalized
cross sections even in the high-intensity limit for extreme ultraviolet
wavelengths.


title: Non-Intrusive Load Monitoring: A Review and Outlook

abstract:
  With the roll-out of smart meters the importance of effective non-intrusive
load monitoring (NILM) techniques has risen rapidly. NILM estimates the power
consumption of individual devices given their aggregate consumption. In this
way, the combined consumption must only be monitored at a single, central point
in the household, providing various advantages such as reduced cost for
metering equipment. In this paper we discuss the fundamental building-blocks of
NILM, first giving a taxonomy of appliance models and device signatures and
then explaining common supervised and unsupervised learning methods.
Furthermore, we outline a fundamental algorithm that tackles the task of NILM.
Subsequently, this paper reviews recent research that has brought novel insight
to the field and more effective techniques. Finally, we formulate future
challenges in the domain of NILM and smart meters.


title: Microtubule Defects Influence Kinesin-Based Transport In Vitro

abstract:
  Microtubules are protein polymers that form "molecular highways" for
long-range transport within living cells. Molecular motors actively step along
microtubules to shuttle cellular materials between the nucleus and the cell
periphery; this transport is critical for the survival and health of all
eukaryotic cells. Structural defects in microtubules exist, but whether these
defects impact molecular motor-based transport remains unknown. Here, we report
a new, to our knowledge, approach that allowed us to directly investigate the
impact of such defects. Using a modified optical-trapping method, we examined
the group function of a major molecular motor, conventional kinesin, when
transporting cargos along individual microtubules. We found that microtubule
defects influence kinesin-based transport in vitro. The effects depend on motor
number: cargos driven by a few motors tended to unbind prematurely from the
microtubule, whereas cargos driven by more motors tended to pause. To our
knowledge, our study provides the first direct link between microtubule defects
and kinesin function. The effects uncovered in our study may have physiological
relevance in vivo.


title:
Interplay between velocity and travel distance of kinesin-based
  transport in the presence of tau

abstract:
  Although the disease-relevant microtubule-associated protein tau is known to
severely inhibit kinesin-based transport in vitro, the potential mechanisms for
reversing this detrimental effect to maintain healthy transport in cells remain
unknown. Here we report the unambiguous upregulation of multiple-kinesin travel
distance despite the presence of tau, via decreased single-kinesin velocity.
Interestingly, the presence of tau also modestly reduced cargo velocity in
multiple-kinesin transport, and our stochastic simulations indicate that the
tau-mediated reduction in single-kinesin travel underlies this observation.
Taken together, our observations highlight a nontrivial interplay between
velocity and travel distance for kinesin transport, and suggest that
single-kinesin velocity is a promising experimental handle for tuning the
effect of tau on multiple-kinesin travel distance.


title: Chemical distribution of HII regions towards the Galactic anticentre

abstract:
  We study the physical and chemical properties of a sample of HII regions
located at RG >11 kpc and present the radial distribution of abundances towards
the Galaxy anticentre.
  We carried out optical spectroscopic observations of nine HII regions with
the WHT. The sample was increased by searching the literature for optical
observations of regions towards the Galactic anticentre, re-analysing them to
obtain a single sample of 23 objects covering the Galactocentric radius from 11
kpc to 18 kpc to be processed in a homogeneous and consistent manner. Accurate
electron densities and temperatures of several ionic species were derived in 13
HII regions. These physical parameters were applied to the spectra to determine
direct total chemical abundances. For those regions without direct estimations
of temperature, chemical abundances were derived by performing tailor-made
photoionisation models and/or by using an empirical relation obtained from
radio recombination and optical temperatures.
  We performed weighted least-squares fits to the distribution of the derived
abundances along the Galactocentric distances to study the radial gradients of
metallicity. The distributions O/H, N/H, S/H, and Ar/H towards the anticentre
can be represented by decreasing linear radial gradients, while in the case of
N/O abundances the radial distribution is better fitted with a two-zone model.
The He/H radial gradient is presented here for the first time; we find a slope
that is not significantly different from zero. The derived gradient for oxygen
shows a clear decrease with distance with a slope of -0.053dex/kpc. Although a
shallower slope at large Galactocentric distances is suggested by our data, the
flattening of the distribution cannot be confirmed and more objects towards the
anticentre need to be studied in order to establish the true form of the
metallicity gradient.


title: 2-Selmer near-companion curves

abstract:
  Let $E$ and $A$ be elliptic curves over a number field $K$. Let $\chi$ be a
quadratic character of $K$. We prove the conjecture posed by Mazur and Rubin on
$n$-Selmer near-companion curves in the case $n=2$. Namely, we show if the
difference of the $2$-Selmer ranks of $E^\chi$ and $A^\chi$ is bounded
independent of $\chi$, there is a $G_K$-isomorphism $E[2] \cong A[2]$.


title: Tuning Multiple Motor Travel Via Single Motor Velocity

abstract:
  Microtubule-based molecular motors often work in small groups to transport
cargos in cells. A key question in understanding transport (and its regulation
in vivo) is to identify the sensitivity of multiple-motor-based motion to
various single molecule properties. Whereas both single-motor travel distance
and microtubule binding rate have been demonstrated to contribute to cargo
travel, the role of single-motor velocity is yet to be explored. Here, we
recast a previous theoretical study, and make explicit a potential contribution
of velocity to cargo travel. We test this possibility experimentally, and
demonstrate a strong negative correlation between single-motor velocity and
cargo travel for transport driven by two motors. Our study thus discovers a
previously unappreciated role of single-motor velocity in regulating
multiple-motor transport.


title:
Superconducting Vacuum-Gap Crossovers for High Performance Microwave
  Applications

abstract:
  The design and fabrication of low-loss wide-bandwidth superconducting
vacuum-gap crossovers for high performance millimeter wave applications are
described. In order to reduce ohmic and parasitic losses at millimeter
wavelengths a vacuum gap is preferred relative to dielectric spacer. Here,
vacuum-gap crossovers were realized by using a sacrificial polymer layer
followed by niobium sputter deposition optimized for coating coverage over an
underlying niobium signal layer. Both coplanar waveguide and microstrip
crossover topologies have been explored in detail. The resulting fabrication
process is compatible with a bulk micro-machining process for realizing
waveguide coupled detectors, which includes sacrificial wax bonding, and wafer
backside deep reactive ion etching for creation of leg isolated silicon
membrane structures. Release of the vacuum gap structures along with the wax
bonded wafer after DRIE is implemented in the same process step used to
complete the detector fabrication


title:
Using Missing Types to Improve Partial Identification with Application
  to a Study of HIV Prevalence in Malawi

abstract:
  Frequently, empirical studies are plagued with missing data. When the data
are missing not at random, the parameter of interest is not identifiable in
general. Without additional assumptions, we can derive bounds of the parameters
of interest, which, unfortunately, are often too wide to be informative.
Therefore, it is of great importance to sharpen these worst-case bounds by
exploiting additional information. Traditional missing data analysis uses only
the information of the binary missing data indicator, that is, a certain data
point is either missing or not. Nevertheless, real data often provide more
information than a binary missing data indicator, and they often record
different types of missingness. In a motivating HIV status survey, missing data
may be due to the units' unwillingness to respond to the survey items or their
hospitalization during the visit, and may also be due to the units' temporarily
absence or relocation. It is apparent that some missing types are more likely
to be missing not at random, but other missing types are more likely to be
missing at random. We show that making full use of the missing types results in
narrower bounds of the parameters of interest. In a real-life example, we
demonstrate substantial improvement of more than 50% reduction in bound widths
for estimating the prevalence of HIV in rural Malawi. As we illustrate using
the HIV study, our strategy is also useful for conducting sensitivity analysis
by gradually increasing or decreasing the set of types that are missing at
random. In addition, we propose an easy-to-implement method to construct
confidence intervals for partially identified parameters with bounds expressed
as the minimums and maximums of finite parameters, which is useful for not only
our problem but also many other problems involving bounds.


title:
Targeted Pseudorandom Generators, Simulation Advice Generators, and
  Derandomizing Logspace

abstract:
  Assume that for every derandomization result for logspace algorithms, there
is a pseudorandom generator strong enough to nearly recover the derandomization
by iterating over all seeds and taking a majority vote. We prove under a
precise version of this assumption that $\mathbf{BPL} \subseteq \bigcap_{\alpha
> 0} \mathbf{DSPACE}(\log^{1 + \alpha} n)$.
  We strengthen the theorem to an equivalence by considering two
generalizations of the concept of a pseudorandom generator against logspace. A
targeted pseudorandom generator against logspace takes as input a short uniform
random seed and a finite automaton; it outputs a long bitstring that looks
random to that particular automaton. A simulation advice generator for logspace
stretches a small uniform random seed into a long advice string; the
requirement is that there is some logspace algorithm that, given a finite
automaton and this advice string, simulates the automaton reading a long
uniform random input. We prove that $\bigcap_{\alpha > 0}
\mathbf{promise\mbox{-}BPSPACE}(\log^{1 + \alpha} n) = \bigcap_{\alpha > 0}
\mathbf{promise\mbox{-}DSPACE}(\log^{1 + \alpha} n)$ if and only if for every
targeted pseudorandom generator against logspace, there is a simulation advice
generator for logspace with similar parameters.
  Finally, we observe that in a certain uniform setting (namely, if we only
worry about sequences of automata that can be generated in logspace), targeted
pseudorandom generators against logspace can be transformed into simulation
advice generators with similar parameters.


title: Three Ways to Count Walks in a Digraph

abstract:
  We approach the problem of counting the number of walks in a digraph from
three different perspectives: enumerative combinatorics, linear algebra, and
symbolic dynamics.


title: Dark energy stars: Stable configurations

abstract:
  In present paper a spherically symmetric stellar configuration has been
analyzed by assuming the matter distribution of the stellar configuration is
anisotropic in nature and compared with the realistic objects, namely, the low
mass X-ray binaries (LMXBs) and X-ray pulsars. The analytic solution has been
obtained by utilizing the dark energy equation of state for the interior
solution corresponding to the Schwarzschild exterior vacuum solution at the
junction interface. Several physical properties like energy conditions,
stability, mass-radius ratio, and surface redshift are described through
mathematical calculations as well as graphical plots. It is found that obtained
mass-radius ration of the compact stars candidates like 4U 1820-30, PSR J
1614-2230, Vela X-1 and Cen X-3 are very much consistent with the observed data
by Gangopadhyay et al. (Mon. Not. R. Astron. Soc. 431, 3216 (2013)). So our
proposed model would be useful in the investigation of the possible clustering
of dark energy.


title: Model-independent determination on $H_0$ using the latest $H(z)$ data

abstract:
  We perform the improved constraints on the Hubble constant $H_0$ by using the
model-independent method, Gaussian Processes. Utilizing the latest 36 $H(z)$
measurements, we obtain $H_0=69.21\pm3.72$ km s$^{-1}$ Mpc$^{-1}$, which is
consistent with the Planck 2015 and Riess et al. 2016 analysis at $1\sigma$
confidence level, and reduces the uncertainty from $6.5\%$ (Busti et al. 2014)
to $5.4\%$. Different from the results of Busti et al. 2014 by only using 19
$H(z)$ measurements, our reconstruction results of $H(z)$ and the derived
values of $H_0$ are independent of the choice of covariance functions.


title: Bounce and Collapse in the Slotheonic Universe

abstract:
  In this paper, we examine the cosmological dynamics of a slotheon field in a
linear potential. The slotheon correction term
$\frac{G^{\mu\nu}}{2M^2}\pi_{;\mu}\pi_{;\nu}$ respects the galileon symmetry in
curved space time. We demonstrate the future evolution of universe in this
model. We show that in this scenario, the universe ends with the Big Crunch
singularity like the standard case. The difference being that the time at which
the singularity occurs is delayed in the slotheon gravity. The delay crucially
depends upon the strength of slotheon correction.


title: Influence of Turbulent Fluctuations on Detonation Propagation

abstract:
  The present study addresses the reaction zone structure and burning mechanism
of unstable detonations. Experiments investigated mainly two-dimensional
methane-oxygen cellular detonations in a thin channel geometry. The
sufficiently high temporal resolution permitted to determine the PDF of the
shock distribution, a power-law with an exponent of -3, and the burning rate of
unreacted pockets from their edges - through surface turbulent flames with a
speed approximately 3-7 times larger than the laminar one at the local
conditions. Numerical simulations were performed using a novel Large Eddy
Simulation method where the reactions due to both auto-ignition and turbulent
transport and treated exactly at the sub-grid scale in a reaction-diffusion
formulation. The model is an extension of Kerstein & Menon's Linear Eddy Model
for Large Eddy Simulation to treat flows with shock waves and rapid gasdynamic
transients. The two-dimensional simulations recovered well the amplification of
the laminar flame speed owing to the turbulence generated mainly by the shear
layers originating from the triple points and subsequent Richtmyer-Meshkov
instability associated with the internal pressure waves. The simulations
clarified how the level of turbulence generated controlled the burning rate of
the pockets, the hydrodynamic thickness of the wave, the cellular structure and
its distribution. Three-dimensional simulations were found in general good
agreement with the two-dimensional ones, in that the sub-grid scale model
captured the ensuing turbulent burning once the scales associated with the
cellular dynamics, where turbulent kinetic energy is injected, are well
resolved.


title:
Random fields and the enumerative geometry of lines on real and complex
  hypersurfaces

abstract:
  We derive a formula expressing the average number $E_n$ of real lines on a
random hypersurface of degree $2n-3$ in $\mathbb{R}\textrm{P}^n$ in terms of
the expected modulus of the determinant of a special random matrix. In the case
$n=3$ we prove that the average number of real lines on a random cubic surface
in $\mathbb{R}\textrm{P}^3$ equals: $$E_3=6\sqrt{2}-3.$$ Our technique can also
be used to express the number $C_n$ of complex lines on a generic hypersurface
of degree $2n-3$ in $\mathbb{C}\textrm{P}^n$ in terms of the determinant of a
random Hermitian matrix. As a special case we obtain a new proof of the
classical statement $C_3=27.$
  We determine, at the logarithmic scale, the asymptotic of the quantity $E_n$,
by relating it to $C_n$ (whose asymptotic has been recently computed D.
Zagier). Specifically we prove that: $$\lim_{n\to \infty}\frac{\log E_n}{\log
C_n}=\frac{1}{2}.$$
  Finally we show that this approach can be used to compute the number
$R_n=(2n-3)!!$ of real lines, counted with their intrinsic signs, on a generic
real hypersurface of degree $2n-3$ in $\mathbb{R}\textrm{P}^n$.


title: A Survey of Multi-View Representation Learning

abstract:
  Recently, multi-view representation learning has become a rapidly growing
direction in machine learning and data mining areas. This paper introduces two
categories for multi-view representation learning: multi-view representation
alignment and multi-view representation fusion. Consequently, we first review
the representative methods and theories of multi-view representation learning
based on the perspective of alignment, such as correlation-based alignment.
Representative examples are canonical correlation analysis (CCA) and its
several extensions. Then from the perspective of representation fusion we
investigate the advancement of multi-view representation learning that ranges
from generative methods including multi-modal topic learning, multi-view sparse
coding, and multi-view latent space Markov networks, to neural network-based
methods including multi-modal autoencoders, multi-view convolutional neural
networks, and multi-modal recurrent neural networks. Further, we also
investigate several important applications of multi-view representation
learning. Overall, this survey aims to provide an insightful overview of
theoretical foundation and state-of-the-art developments in the field of
multi-view representation learning and to help researchers find the most
appropriate tools for particular applications.


title:
Manifestation of the $P$-wave diproton resonance in single-pion
  production in $pp$ collisions

abstract:
  It is demonstrated that many important features of single-pion production in
$pp$ collisions at intermediate energies ($T_p \simeq 400$-$800$ MeV) can
naturally be explained by supposing excitation of intermediate diproton
resonances in $pp$ channels ${}^1D_2$, ${}^3F_3$ and ${}^3P_2$, in addition to
conventional mechanisms involving an intermediate $\Delta$-isobar. We predict
for the first time the crucial role of the ${}^3P_2$ diproton resonance, found
in recent experiments on the single-pion production reaction $pp \to
pp({}^1S_0) \pi^0$, in reproducing the proper behavior of spin-correlation
parameters in the reaction $pp \to d \pi^+$ which were poorly described by
conventional meson-exchange models to date. The possible quark structure of the
$P$-wave diproton resonances is also discussed.


title:
Solution theory to Semilinear Hyperbolic Stochastic Partial Differential
  Equations with polynomially bounded coefficients

abstract:
  We study mild solutions of a class of stochastic partial differential
equations, involving operators with polynomially bounded coefficients. We
consider semilinear equations under suitable hyperbolicity hypotheses on the
linear part. We provide conditions on the initial data and on the stochastic
terms, namely, on the associated spectral measure, so that mild solutions exist
and are unique in suitably chosen functional classes. More precisely,
function-valued solutions are obtained, as well as a regularity result.


title:
Towards Air Quality Estimation Using Collected Multimodal Environmental
  Data

abstract:
  This paper presents an open platform, which collects multimodal environmental
data related to air quality from several sources including official open
sources, social media and citizens. Collecting and fusing different sources of
air quality data into a unified air quality indicator is a highly challenging
problem, leveraging recent advances in image analysis, open hardware, machine
learning and data fusion and is expected to result in increased geographical
coverage and temporal granularity of air quality data.


title: Initial Results from the MAJORANA DEMONSTRATOR

abstract:
  Neutrinoless double-beta decay searches seek to determine the nature of
neutrinos, the existence of a lepton violating process, and the effective
Majorana neutrino mass. The {\sc Majorana} Collaboration is assembling an array
of high purity Ge detectors to search for neutrinoless double-beta decay in
$^{76}$Ge. The {\sc Majorana Demonstrator} is composed of 44.8~kg (29.7 kg
enriched in $^{76}$Ge) of Ge detectors in total, split between two modules
contained in a low background shield at the Sanford Underground Research
Facility in Lead, South Dakota. The initial goals of the {\sc Demonstrator} are
to establish the required background and scalability of a Ge-based,
next-generation, tonne-scale experiment. Following a commissioning run that
began in 2015, the first detector module started physics data production in
early 2016. We will discuss initial results of the Module 1 commissioning and
first physics run, as well as the status and potential physics reach of the
full {\sc Majorana Demonstrator} experiment. The collaboration plans to
complete the assembly of the second detector module by mid-2016 to begin full
data production with the entire array.


title:
ODE Maximum Principle at Infinity and Non-Compact Solutions of IMCF in
  Hyperbolic Space

abstract:
  In this work we extend the ODE Maximum principle of Hamilton to non-compact
hypersurfaces using the Omari-Yau maximum principle at infinity. As an
application of this result, we investigate Inverse Mean Curvature Flow (IMCF)
of non-compact hypersurfaces in hyperbolic space. Specifically, we look at
bounded graphs over horospheres in $\mathbb{H}^{n+1}$ and show long time
existence of the flow as well as asymptotic convergence to horospheres.


title:
Field induced Lifshitz transition in UPt$_2$Si$_2$: Fermi surface under
  extreme conditions

abstract:
  We have measured Hall effect, magnetotransport and magnetostriction on the
field induced phases of single crystalline UPt$_2$Si$_2$ in magnetic fields up
to 60\,T at temperatures down to 50\,mK. For the magnetic field applied along
the $c$ axis we observe strong changes in the Hall effect at the phase
boundaries. From a comparison to band structure calculations utilizing the
concept of a dual nature of the uranium 5$f$ electrons, we find evidence for
field induced topological changes of the Fermi surface due to at least one
Lifshitz transition. Furthermore, we find a unique history dependence of the
magnetotransport and magnetostriction data, indicating that the Lifshitz type
transition is of a discontinuous nature, as predicted for interacting electron
systems.


title: Deciding equivalence with sums and the empty type

abstract:
  The logical technique of focusing can be applied to the $\lambda$-calculus;
in a simple type system with atomic types and negative type formers (functions,
products, the unit type), its normal forms coincide with $\beta\eta$-normal
forms. Introducing a saturation phase gives a notion of quasi-normal forms in
presence of positive types (sum types and the empty type). This rich structure
let us prove the decidability of $\beta\eta$-equivalence in presence of the
empty type, the fact that it coincides with contextual equivalence, and a
finite model property.


title:
Anomaly-driven inverse cascade and inhomogeneities in a magnetized
  chiral plasma in the early Universe

abstract:
  By making use of a simple model that captures the key features of the
anomalous Maxwell equations, we study the role of inhomogeneities on the
evolution of magnetic fields in a chiral plasma. We find that inhomogeneities
of the chiral asymmetry by themselves do not prevent the anomaly-driven inverse
cascade and, as in the homogeneous case, the magnetic helicity is transferred
from shorter to longer wavelength helical modes of the magnetic field. However,
we also find that the evolution appears to be sensitive to the effects of
diffusion. In the case when diffusion is negligible, the inverse cascade slows
down considerably compared to the homogeneous scenario. In the case of the
primordial plasma, though, we find that the diffusion is substantial and
efficiently suppresses chiral asymmetry inhomogeneities. As a result, the
inverse cascade proceeds practically in the same way as in the chirally
homogeneous model.


title:
A Bayesian Approach to Modelling Fine-Scale Spatial Dynamics of
  Non-State Terrorism: World Study, 2002-2013

abstract:
  To this day, terrorism persists as a worldwide threat, as exemplified by the
ongoing lethal attacks perpetrated by ISIS in Iraq, Syria, Al Qaeda in Yemen,
and Boko Haram in Nigeria. In response, states deploy various counterterrorism
policies, the costs of which could be reduced through efficient preventive
measures. Statistical models able to account for complex spatio-temporal
dependencies have not yet been applied, despite their potential for providing
guidance to explain and prevent terrorism. In an effort to address this
shortcoming, we employ hierarchical models in a Bayesian context, where the
spatial random field is represented by a stochastic partial differential
equation. Our results confirm the contagious nature of the lethality of
terrorism and the number of lethal terrorist attacks in both space and time.
Moreover, the frequency of lethal attacks tends to be higher in richer areas,
close to large cities, and within democratic countries. In contrast, attacks
are more likely to be lethal far away from large cities, at higher altitudes,
in poorer areas, and in locations with higher ethnic diversity. We argue that,
on a local scale, the lethality of terrorism and the frequency of lethal
attacks are driven by antagonistic mechanisms.


title: Small data global regularity for half-wave maps

abstract:
  We formulate the half-wave maps problem with target $S^2$ and prove global
regularity in sufficiently high spatial dimensions for a class of small
critical data in Besov spaces.


title: New hallmarks of criticality in recurrent neural networks

abstract:
  A rigorous understanding of brain dynamics and function requires a conceptual
bridge between multiple levels of organization, including neural spiking and
network-level population activity. Mounting evidence suggests that neural
networks of cerebral cortex operate at criticality. How operating near this
network state impacts the variability of neuronal spiking is largely unknown.
Here we show in a computational model that two prevalent features of cortical
single-neuron activity, irregular spiking and the decline of response
variability at stimulus onset, are both emergent properties of a recurrent
network operating near criticality. Importantly, our work reveals that the
relation between the irregularity of spiking and the number of input
connections to a neuron, i.e., the in-degree, is maximized at criticality. Our
findings establish criticality as a unifying principle for the variability of
single-neuron spiking and the collective behavior of recurrent circuits in
cerebral cortex.


title: Reconstruction phases in the planar three- and four-vortex problems

abstract:
  Pure reconstruction phases, geometric and dynamic, are computed in the
$N$-point-vortex model in the plane, for the cases $N=3$ and $N=4$. The phases
are computed relative to a metric-orthogonal connection on appropriately
defined principal fiber bundles. The metric is similar to the kinetic energy
metric for point masses but with the masses replaced by vortex strengths. The
geometric phases are shown to be proportional to areas enclosed by the closed
orbit on the symmetry reduced spaces. More interestingly, simple formulae are
obtained for the dynamic phases, analogous to Montgomery's result for the free
rigid body, which show them to be proportional to the time period of the
symmetry reduced closed orbits. For the case $ N = 3 $ a non-zero total vortex
strength is assumed. For the case $ N = 4 $ the vortex strengths are assumed
equal.


title: Actions of finite groups and smooth functions on surfaces

abstract:
  Let $f:M\to \mathbb{R}$ be a Morse function on a smooth closed surface, $V$
be a connected component of some critical level of $f$, and $\mathcal{E}_V$ be
its atom. Let also $\mathcal{S}(f)$ be a stabilizer of the function $f$ under
the right action of the group of diffeomorphisms $\mathrm{Diff}(M)$ on the
space of smooth functions on $M,$ and $\mathcal{S}_V(f) =
\{h\in\mathcal{S}(f)\,| h(V) = V\}.$ The group $\mathcal{S}_V(f)$ acts on the
set $\pi_0\partial \mathcal{E}_V$ of connected components of the boundary of
$\mathcal{E}_V.$ Therefore we have a homomorphism $\phi:\mathcal{S}(f)\to
\mathrm{Aut}(\pi_0\partial \mathcal{E}_V)$. Let also $G = \phi(\mathcal{S}(f))$
be the image of $\mathcal{S}(f)$ in $\mathrm{Aut}(\pi_0\partial
\mathcal{E}_V).$
  Suppose that the inclusion $\partial \mathcal{E}_V\subset M\setminus V$
induces a bijection $\pi_0 \partial \mathcal{E}_V\to\pi_0(M\setminus V).$ Let
$H$ be a subgroup of $G.$ We present a sufficient condition for existence of a
section $s:H\to \mathcal{S}_V(f)$ of the homomorphism $\phi,$ so, the action of
$H$ on $\partial \mathcal{E}_V$ lifts to the $H$-action on $M$ by
$f$-preserving diffeomorphisms of $M$.
  This result holds for a larger class of smooth functions $f:M\to \mathbb{R}$
having the following property: for each critical point $z$ of $f$ the germ of
$f$ at $z$ is smoothly equivalent to a homogeneous polynomial $\mathbb{R}^2\to
\mathbb{R}$ without multiple linear factors.


title:
McKay Correspondence for semisimple Hopf actions on regular graded
  algebras, II

abstract:
  We continue our study of the McKay Correspondence for grading preserving
actions of semisimple Hopf algebras H on (noncommutative) Artin-Schelter
regular algebras A. Here, we establish correspondences between module
categories over A^H, over A\#H, and over \End_{A^H} A. We also study
homological properties of (endomorphism rings of) maximal Cohen-Macaulay
modules over A^H.


title: Seer: Empowering Software Defined Networking with Data Analytics

abstract:
  Network complexity is increasing, making network control and orchestration a
challenging task. The proliferation of network information and tools for data
analytics can provide an important insight into resource provisioning and
optimisation. The network knowledge incorporated in software defined networking
can facilitate the knowledge driven control, leveraging the network
programmability. We present Seer: a flexible, highly configurable data
analytics platform for network intelligence based on software defined
networking and big data principles. Seer combines a computational engine with a
distributed messaging system to provide a scalable, fault tolerant and
real-time platform for knowledge extraction. Our first prototype uses Apache
Spark for streaming analytics and open network operating system (ONOS)
controller to program a network in real-time. The first application we
developed aims to predict the mobility pattern of mobile devices inside a smart
city environment.


title:
Where Does the Density Localize? Convergent Behavior for Global Hybrids,
  Range Separation, and DFT+U

abstract:
  Approximate density functional theory (DFT) suffers from many-electron self-
interaction error, otherwise known as delocalization error, that may be
diagnosed and then corrected through elimination of the deviation from exact
piecewise linear behavior between integer electron numbers. Although paths to
correction of energetic delocalization error are well- established, the impact
of these corrections on the electron density is less well-studied. Here, we
compare the effect on density delocalization of DFT+U, global hybrid tuning,
and range- separated hybrid tuning on a diverse test set of 32 transition metal
complexes and observe the three methods to have qualitatively equivalent
effects on the ground state density. Regardless of valence orbital diffuseness
(i.e., from 2p to 5p), ligand electronegativity (i.e., from Al to O), basis set
(i.e., plane wave versus localized basis set), metal (i.e., Ti, Fe, Ni) and
spin state, or tuning method, we consistently observe substantial charge loss
at the metal and gain at ligand atoms (ca. 0.3-0.5 e or more). This charge loss
at the metal is preferentially from the minority spin, leading to increasing
magnetic moment as well. Using accurate wavefunction theory references, we
observe that a minimum error in partial charges and magnetic moments occur at
higher tuning parameters than typically employed to eliminate energetic
delocalization error. These observations motivate the need to develop
multi-faceted approximate-DFT error correction approaches that separately treat
density delocalization and energetic errors in order to recover both correct
density and magnetization properties.


title: Feature Learning from Spectrograms for Assessment of Personality Traits

abstract:
  Several methods have recently been proposed to analyze speech and
automatically infer the personality of the speaker. These methods often rely on
prosodic and other hand crafted speech processing features extracted with
off-the-shelf toolboxes. To achieve high accuracy, numerous features are
typically extracted using complex and highly parameterized algorithms. In this
paper, a new method based on feature learning and spectrogram analysis is
proposed to simplify the feature extraction process while maintaining a high
level of accuracy. The proposed method learns a dictionary of discriminant
features from patches extracted in the spectrogram representations of training
speech segments. Each speech segment is then encoded using the dictionary, and
the resulting feature set is used to perform classification of personality
traits. Experiments indicate that the proposed method achieves state-of-the-art
results with a significant reduction in complexity when compared to the most
recent reference methods. The number of features, and difficulties linked to
the feature extraction process are greatly reduced as only one type of
descriptors is used, for which the 6 parameters can be tuned automatically. In
contrast, the simplest reference method uses 4 types of descriptors to which 6
functionals are applied, resulting in over 20 parameters to be tuned.


title:
Identification of the low-energy excitations in a quantum critical
  system

abstract:
  We have identified low-energy magnetic excitations in a doped quantum
critical system by means of polarized neutron scattering experiments. The
presence of these excitations could explain why
Ce(Fe$_{0.76}$Ru$_{0.24}$)$_2$Ge$_2$ displays dynamical scaling in the absence
of local critical behavior or long-range spin-density wave criticality. The
low-energy excitations are associated with the reorientations of the superspins
of fully ordered, isolated magnetic clusters that form spontaneously upon
lowering the temperature. The system houses both frozen clusters and dynamic
clusters, as predicted by Hoyos and Vojta [Phys. Rev. B 74, 140401 (R) (2006)].


title:
Superposition of fundamental solutions of second order quasilinear
  equations

abstract:
  We prove a superposition principle in the spirit of Crandall-Zhang and
Lindqvist-Manfredi for a class of second order quasilinear equations. Riesz
potentials of nonnegative and compactly supported continuous functions are
either subsolutions or supersolutions for the operators associated to the
stationary form of the doubly nonlinear diffusion equation. This class of
operators includes both the p-Laplacian as well as the stationary porous medium
equation.


title: Model error moment estimation via data assimilation

abstract:
  Using a dynamical model to make predictions about a system has many sources
of error. These can include errors in how the model was initialised but also
errors in the dynamics of the model itself. For many applications in data
assimilation, probabilistic forecasting, or model improvement, these model
errors need to be known over the timestep of the model, not over a
time-averaged period. Using a forecast from a state that combines observational
information as well as prior information we can gain an approximation to the
statistics of the model errors on the timescale of the model that is required.
Here we give bounds on the errors in the estimation of the mean and covariance
of the errors in the model equations in terms of the errors made in the state
estimation. This is the first time that such a result has been derived. The
result shows to what extent the state estimation must constrain the analysis in
order to obtain a specified error on the mean or covariance of the model
errors. This is particularly useful for experimental design as it indicates the
necessary information content required in observations of the dynamical system.


title: A Duality Result for Robust Optimization with Expectation Constraints

abstract:
  This paper demonstrates a practical method for computing the solution of an
expectation-constrained robust maximization problem with immediate applications
to model-free no-arbitrage bounds and super-replication values for many
financial derivatives. While the previous literature has connected
super-replication values to a convex minimization problem whose objective
function is related to a sequence of iterated concave envelopes, we show how
this whole process can be encoded in a single convex minimization problem. The
natural finite-dimensional approximation of this minimization problem results
in an easily-implementable sparse linear program. We highlight this technique
by obtaining no-arbitrage bounds on the prices of forward-starting options,
continuously-monitored variance swaps, and discretely-monitored gamma swaps,
each subject to observed bid-ask spreads of finitely-many vanilla options.


title: Artin L-functions of small conductor

abstract:
  We study the problem of finding the Artin L-functions with the smallest
conductor for a given Galois type. We adapt standard analytic techniques to our
novel situation of fixed Galois type and get much improved lower bounds on the
smallest conductor. For small Galois types we use complete tables of number
fields to determine the actual smallest conductor.


title: When Ext is a Batalin-Vilkovisky algebra

abstract:
  We show under what conditions the complex computing general Ext-groups
carries the structure of a cyclic operad such that Ext becomes a
Batalin-Vilkovisky algebra. This is achieved by transferring cyclic cohomology
theories for the dual of a (left) Hopf algebroid to the complex in question,
which asks for the notion of contramodules introduced along with comodules by
Eilenberg-Moore half a century ago. Another crucial ingredient is an explicit
formula for the inverse of the Hopf-Galois map on the dual, by which we
illustrate recent categorical results and answer a long-standing open question.
As an application, we prove that the Hochschild cohomology of an associative
algebra A is Batalin-Vilkovisky if A itself is a contramodule over its
enveloping algebra A \otimes A^op. This is, for example, the case for symmetric
algebras and Frobenius algebras with semisimple Nakayama automorphism. We also
recover the construction for Hopf algebras.


title: A Local Inverse Formula and a Factorization

abstract:
  When a matrix has a banded inverse there is a remarkable formula that quickly
computes that inverse, using only local information in the original matrix.
This local inverse formula holds more generally, for matrices with sparsity
patterns that are examples of chordal graphs or perfect eliminators. The
formula has a long history going back at least as far as the completion problem
for covariance matrices with missing data. Maximum entropy estimates,
log-determinants, rank conditions, the Nullity Theorem and wavelets are all
closely related, and the formula has found wide applications in machine
learning and graphical models. We describe that local inverse and explain how
it can be understood as a matrix factorization.


title:
The spectrum of light isovector mesons with $C=+1$ from the COMPASS
  experiment

abstract:
  Based on the largest event sample of diffractively produced
$\pi^-\pi^-\pi^+$, obtained by a pion beam of $190~\rm{GeV/c}$ momentum, the
COMPASS collaboration has performed the most advanced partial wave analysis on
multi-body final states, using the isobar model. The large number of waves
included in the analysis reduces truncation effects. We have used fourteen out
of a total of eighty-eight waves, to extract resonance parameters for eleven
light meson candidates, most of them observed previously. The coherence of the
analysis and the large variety of systematic studies has allowed to determine
mass and width of most $a_{J}$ and $\pi_{J}$ states with six different values
of $J^{PC}$ below a mass of $2.1~\rm{GeV/c^2}$, with high confidence. We
exploited that the production rates of resonant and non-resonant contributions
in these fourteen waves vary differently with the four-momentum transfer
squared in the reaction. In addition, we have performed the first isobar-freed
analysis in diffraction, from which we have determined the shape of the
$[\pi\pi]_{S-wave}$ isobar for different $J^{PC}$ of the $3\pi$ system.


title: Giant planet formation at the pressure maxima of protoplanetary disks

abstract:
  In the classical core-accretion planet formation scenario, rapid inward
migration and accretion timescales of kilometer size planetesimals may not
favor the formation of massive cores of giant planets before the dissipation of
protoplanetary disks. On the other hand, the existence of pressure maxima in
the disk could act as migration traps and locations for solid material
accumulation, favoring the formation of massive cores. We aim to study the
radial drift of pebbles and planetesimals and planet migration at pressure
maxima in a protoplanetary disk and their implications for the formation of
massive cores as triggering a gaseous runaway accretion phase. The time
evolution of a viscosity driven accretion disk is solved numerically
introducing a a dead zone as a low-viscosity region in the protoplanetary disk.
A population of pebbles and planetesimals evolving by radial drift and
accretion by the planets is also considered. Finally, the embryos embedded in
the disk grow by the simultaneous accretion of pebbles, planetesimals and the
surrounding gas. Our simulations show that the pressure maxima generated at the
edges of the low-viscosity region of the disk act as planet migration traps,
and that the pebble and planetesimal surface densities are significantly
increased due to the radial drift towards pressure maxima locations. However,
our simulations also show that migration trap locations and solid material
accumulation locations are not exactly at the same positions. Thus, a planet's
semi-major axis oscillations around zero torque locations, predicted by MHD and
HD simulations, are needed for the planet to accrete all the available material
accumulated at the pressure maxima. Pressure maxima generated at the edges of a
low-viscosity region of a protoplanetary disk seem to be preferential locations
for the formation and trap of massive cores.


title:
Infall/Expansion Velocities in the Low-Mass Dense Cores L492, L694-2,
  and L1521F: Dependence on Position and Molecular Tracer

abstract:
  Although surveys of infall motions in dense cores have been carried out for
years, few surveys have focused on mapping infall across cores using multiple
spectral line observations. To fill this gap, we present IRAM 30-m Telescope
maps of N2H+(1-0), DCO+(2-1), DCO+(3-2), and HCO+(3-2) emission towards two
prestellar cores (L492 and L694-2) and one protostellar core (L1521F). We find
that the measured infall velocity varies with position across each core and
choice of molecular line, likely as a result of radial variations in core
chemistry and dynamics. Line-of-sight infall speeds estimated from DCO+(2-1)
line profiles can decrease by 40-50 m/s when observing at a radial offset >=
0.04 pc from the core's dust continuum emission peak. Median infall speeds
calculated from all observed positions across a core can also vary by as much
as 65 m/s depending on the transition. These results show that while
single-pointing, single-transition surveys of core infall velocities may be
good indicators of whether a core is either contracting or expanding, the
magnitude of the velocities they measure are significantly impacted by the
choice of molecular line, proximity to the core center, and core evolutionary
state.


title: Ensemble Validation: Selectivity has a Price, but Variety is Free

abstract:
  Suppose some classifiers are selected from a set of hypothesis classifiers to
form an equally-weighted ensemble that selects a member classifier at random
for each input example. Then the ensemble has an error bound consisting of the
average error bound for the member classifiers, a term for selectivity that
varies from zero (if all hypothesis classifiers are selected) to a standard
uniform error bound (if only a single classifier is selected), and small
constants. There is no penalty for using a richer hypothesis set if the same
fraction of the hypothesis classifiers are selected for the ensemble.


title: Some exact solutions in K-essence theory isotropic cosmology

abstract:
  We use a simple form of the K-essence theory and apply it to the classic
isotropic cosmological model and seek exact solutions. The particular form of
the kinetic term that we choose is $K \left(\phi, X \right)= K_0(\phi)X^m
+K_1$. The resulting field equations in the homogeneous and isotropic cosmology
(FRW)is considered. Several exact solutions are obtained.


title:
Fingerprints of bosonic symmetry protected topological state in a
  quantum point contact

abstract:
  In this work, we study the transport through a quantum point contact for
bosonic helical liquid that exists at the edge of a bilayer graphene under a
strong magnetic field. We identify "smoking gun" transport signatures to
distinguish bosonic symmetry protected topological (BSPT) state from fermionic
two-channel quantum spin Hall (QSH) state in this system. In particular, a
novel charge insulator/spin conductor phase is found for BSPT state, while
either charge insulator/spin insulator or charge conductor/spin conductor phase
is expected for the two-channel QSH state. Consequently, a simple transport
measurement will reveal the fingerprint of bosonic topological physics in
bilayer graphene systems.


title:
First law and Smarr formula of black hole mechanics in nonlinear gauge
  theories

abstract:
  Motivated by the fact that Bardeen black holes do not satisfy the usual first
law and Smarr formula, we derive a generalized first law from the Lagrangian of
nonlinear gauge field coupled to gravity. In our treatment, the Lagrangian is a
function of the electromagnetic invariant as well as some additional
parameters. Consequently, we obtain new terms in the first law. With our
formula, we find the correct forms of the first law for Bardeen black holes and
Born-Infeld black holes. By scaling arguments, we also derive a general Smarr
formula from the first law. Our results apply to a wide class of black holes
with nonlinear gauge fields.


title:
Find Your Own Way: Weakly-Supervised Segmentation of Path Proposals for
  Urban Autonomy

abstract:
  We present a weakly-supervised approach to segmenting proposed drivable paths
in images with the goal of autonomous driving in complex urban environments.
Using recorded routes from a data collection vehicle, our proposed method
generates vast quantities of labelled images containing proposed paths and
obstacles without requiring manual annotation, which we then use to train a
deep semantic segmentation network. With the trained network we can segment
proposed paths and obstacles at run-time using a vehicle equipped with only a
monocular camera without relying on explicit modelling of road or lane
markings. We evaluate our method on the large-scale KITTI and Oxford RobotCar
datasets and demonstrate reliable path proposal and obstacle segmentation in a
wide variety of environments under a range of lighting, weather and traffic
conditions. We illustrate how the method can generalise to multiple path
proposals at intersections and outline plans to incorporate the system into a
framework for autonomous urban driving.


title:
Adversary Resistant Deep Neural Networks with an Application to Malware
  Detection

abstract:
  Beyond its highly publicized victories in Go, there have been numerous
successful applications of deep learning in information retrieval, computer
vision and speech recognition. In cybersecurity, an increasing number of
companies have become excited about the potential of deep learning, and have
started to use it for various security incidents, the most popular being
malware detection. These companies assert that deep learning (DL) could help
turn the tide in the battle against malware infections. However, deep neural
networks (DNNs) are vulnerable to adversarial samples, a flaw that plagues most
if not all statistical learning models. Recent research has demonstrated that
those with malicious intent can easily circumvent deep learning-powered malware
detection by exploiting this flaw.
  In order to address this problem, previous work has developed various defense
mechanisms that either augmenting training data or enhance model's complexity.
However, after a thorough analysis of the fundamental flaw in DNNs, we discover
that the effectiveness of current defenses is limited and, more importantly,
cannot provide theoretical guarantees as to their robustness against
adversarial sampled-based attacks. As such, we propose a new adversary
resistant technique that obstructs attackers from constructing impactful
adversarial samples by randomly nullifying features within samples. In this
work, we evaluate our proposed technique against a real world dataset with
14,679 malware variants and 17,399 benign programs. We theoretically validate
the robustness of our technique, and empirically show that our technique
significantly boosts DNN robustness to adversarial samples while maintaining
high accuracy in classification. To demonstrate the general applicability of
our proposed method, we also conduct experiments using the MNIST and CIFAR-10
datasets, generally used in image recognition research.


title:
Spontaneous Emission and Light Extraction Enhancement of Light Emitting
  Diode Using Partially-Reflecting Metasurface Cavity (PRMC)

abstract:
  The enhancement of the power conversion efficiency (PCE), and subsequent
reduction of cost, of light emitting diodes (LEDs) is of crucial importance in
the current lightening market. For this reason, we propose here a PCE-enhanced
LED architecture, based on a partially reflecting metasurface cavity (PRMC)
structure. This structure simultaneously enhances the light extraction
efficiency (LEE) and the spontaneous emission rate (SER) of the LED by
enforcing the emitted light to radiate perpendicularly to the device, so as to
suppress wave trapping and enhance field confinement near the emitter, while
ensuring cavity resonance matching and maximal constructive field interference.
The PRMC structure is designed using a recent surface susceptibility
metasurface synthesis technique. A PRMC blue LED design is presented and
demonstrated by full-wave simulation to provide LEE and SER enhancements by
factors 4.0 and 1.9, respectively, which correspond to PCE enhancement factors
of 6.2, 5.2 and 4.5 for IQEs of 0.25, 0.5 and 0.75, respectively, suggesting
that the PRMC concept has a promising potential in LED technology.


title: Observable acceleration of jets by a Kerr black hole

abstract:
  In the framework of a model based on the gravitational field of the Kerr
black hole, we turn to investigate the kinematic behavior of extragalactic
jets. We analytically calculate the observable velocities and accelerations
along any geodesic. Then, by numerical calculations, we apply our results to a
geodesic, typical of the M87 jet, and probe our results by confrontation to
recent observations. A transition from non-relativistic to ultrarelativistic
speeds at subparsec scale is highlighted. This transition comes sooner and more
abruptly than in models based on magnetic paradigm, which indicates that we
need a weaker magnetic field to explain observed synchrotron radiation. We
attribute the ejection phenomenon to the repulsive effect of the
gravitomagnetic Kerr field.


title:
Sources of Emittance in RF Photocathode Injectors: Intrinsic emittance,
  space charge forces due to non-uniformities, RF and solenoid effects

abstract:
  Advances in electron beam technology have been central to creating the
current generation of x-ray free electron lasers and ultra-fast electron
microscopes. These once exotic devices have become essential tools for basic
research and applied science. One important beam technology for both is the
electron source which, for many of these instruments, is the photocathode gun.
The invention of the photocathode gun and the concepts of emittance
compensation and beam matching in the presence of space charge and RF forces
have made these high-quality beams possible. Achieving even brighter beams
requires taking a finer resolution view of the electron dynamics near the
cathode during photoemission and the initial acceleration of the beam. In
addition, the high-brightness beam is more sensitive to degradation by the
optical aberrations of the gun's field and the magnetic lenses. This paper
discusses these topics including the beam properties due to photoemission
physics, space charge effects close to the cathode, and optical distortions
introduced by the RF and solenoid fields. Analytic relations for these
phenomena are derived and compared with numerical simulations.


title:
On the Construction of Safe Controllable Regions for Affine Systems with
  Applications to Robotics

abstract:
  This paper studies the problem of constructing in-block controllable (IBC)
regions for affine systems. That is, we are concerned with constructing regions
in the state space of affine systems such that all the states in the interior
of the region are mutually accessible through the region's interior by applying
uniformly bounded inputs. We first show that existing results for checking
in-block controllability on given polytopic regions cannot be easily extended
to address the question of constructing IBC regions. We then explore the
geometry of the problem to provide a computationally efficient algorithm for
constructing IBC regions. We also prove the soundness of the algorithm. We then
use the proposed algorithm to construct safe speed profiles for different
robotic systems, including fully-actuated robots, ground robots modeled as
unicycles with acceleration limits, and unmanned aerial vehicles (UAVs).
Finally, we present several experimental results on UAVs to verify the
effectiveness of the proposed algorithm. For instance, we use the proposed
algorithm for real-time collision avoidance for UAVs.


title:
Many-body localization in Ising models with random long-range
  interactions

abstract:
  We theoretically investigate the many-body localization phase transition in a
one-dimensional Ising spin chain with random long-range spin-spin interactions,
$V_{ij}\propto\left|i-j\right|^{-\alpha}$, where the exponent of the
interaction range $\alpha$ can be tuned from zero to infinitely large. By using
exact diagonalization, we calculate the half-chain entanglement entropy and the
energy spectral statistics and use them to characterize the phase transition
towards the many-body localization phase at infinite temperature and at
sufficiently large disorder strength. We perform finite-size scaling to extract
the critical disorder strength and the critical exponent of the divergent
localization length. With increasing $\alpha$, the critical exponent
experiences a sharp increase at about $\alpha=1$ and then gradually decreases
to a value found earlier in a disordered short-ranged interacting spin chain.
For $\alpha<1$, we find that the system is mostly localized and the increase in
the disorder strength may drive a transition between two many-body localized
phases. In contrast, for $\alpha>1$, the transition is from a thermalized phase
to the many-body localization phase. Our predictions could be experimentally
tested with ion-trap quantum emulator with programmable random long-range
interactions, or with randomly distributed Rydberg atoms or polar molecules in
lattices.


title:
A Model to Estimate First-Order Mutation Coverage from Higher-Order
  Mutation Coverage

abstract:
  The test suite is essential for fault detection during software development.
First-order mutation coverage is an accurate metric to quantify the quality of
the test suite. However, it is computationally expensive. Hence, the adoption
of this metric is limited. In this study, we address this issue by proposing a
realistic model able to estimate first-order mutation coverage using only
higher-order mutation coverage. Our study shows how the estimation evolves
along with the order of mutation. We validate the model with an empirical study
based on 17 open-source projects.


title:
SU(2) Flat Connection on Riemann Surface and Twisted Geometry with
  Cosmological Constant

abstract:
  SU(2) flat connection on 2D Riemann surface is shown to relate to the
generalized twisted geometry in 3D space with cosmological constant. Various
flat connection quantities on Riemann surface are mapped to the geometrical
quantities in discrete 3D space. We propose that the moduli space of SU(2) flat
connections on Riemann surface generalizes the phase space of twisted geometry
or Loop Quantum Gravity to include the cosmological constant.


title: ECAT: Event Capture Annotation Tool

abstract:
  This paper introduces the Event Capture Annotation Tool (ECAT), a
user-friendly, open-source interface tool for annotating events and their
participants in video, capable of extracting the 3D positions and orientations
of objects in video captured by Microsoft's Kinect(R) hardware. The modeling
language VoxML (Pustejovsky and Krishnaswamy, 2016) underlies ECAT's object,
program, and attribute representations, although ECAT uses its own spec for
explicit labeling of motion instances. The demonstration will show the tool's
workflow and the options available for capturing event-participant relations
and browsing visual data. Mapping ECAT's output to VoxML will also be
addressed.


title:
How Particles can Emerge in a Relativistic Version of Bohmian Quantum
  Field Theory: Part 2 - Fermions

abstract:
  It is shown how Fermionic material particles can emerge from a covariant
formulation of the de Broglie-Bohm theory. Material particles are continuous
fields, formed as the eigenvalue of the Schrodinger field operator, evaluated
along a Bohmian trajectory. The motivation for this work is due to a theorem
proved by Malament that states there cannot be a relativistic quantum mechanics
of localizable particles.


title:
High-density kaonic-proton matter (KPM) composed of Lambda* equiv K-p
  multiplets and its astrophysical connections

abstract:
  We propose and examine a new high-density composite of $\Lambda^* \equiv K^-p
= (s \bar{u}) \otimes (uud)$, which may be called {\it Kaonic Proton Matter
(KPM)}, or simply, {\it $\Lambda^* $-Matter}, where substantial shrinkage of
baryonic bound systems originating from the strong attraction of the
$(\bar{K}N)^{I=0}$ interaction takes place, providing a ground-state neutral
baryonic system with a huge energy gap. The mass of an ensemble of $(K^-p)_m$,
where $m$, the number of the $K^-p$ pair, is larger than $m \approx 10$, is
predicted to drop down below its corresponding neutron ensemble, $(n)_m$, since
the attractive interaction is further increased by the Heitler-London type
molecular covalency, as well as by chiral symmetry restoration of the QCD
vacuum. Since the seed clusters ($K^-p$, $K^-pp$ and $K^-K^-pp$) are
short-lived, the formation of such a stabilized relic ensemble, $(K^-p)_m$, may
be conceived during the Big-Bang Quark Gluon Plasma (QGP) period in the early
universe before the hadronization and $quark$-$anti$-$quark$ annihilation
proceed. At the final stage of baryogenesis a substantial amount of primordial
($\bar{u},\bar{d}$)'s are transferred and captured into {\it KPM}, where the
anti-quarks find places to survive forever. The expected {\it KPM} state may be
{\it cold, dense and neutral $\bar{q} q$-hybrid ({\it Quark Gluon Bound (QGB)})
states, $[s(\bar{u} \otimes u) ud]_m$,} to which the relic of the disappearing
anti-quarks plays an essential role as hidden components. The {\it KPM} may
also be produced during the formation and decay of neutron stars.


title: Twisted solutions to a simplified Ericksen-Leslie equation

abstract:
  In this article we construct global solutions to a simplified Ericksen-Leslie
system on $\mathbb{R}^3$. The constructed solutions are twisted and periodic
along the $x_3$-axis with period $d = 2\pi \big/ \mu$. Here $\mu > 0$ is the
twist rate. $d$ is the distance between two planes which are parallel to the
$x_1x_2$-plane. Liquid crystal material is placed in the region enclosed by
these two planes. Given a well-prepared initial data, our solutions exist
classically for all $t \in [0, \infty)$. However these solutions become
singular at all points on the $x_3$-axis and escape into third dimension
exponentially while $t \rightarrow \infty$. An optimal blow up rate is also
obtained.


title:
Exact out-of-time-ordered correlation functions for an interacting
  lattice fermion model

abstract:
  Exact solutions for local equilibrium and nonequilibrium out-of-time-ordered
correlation (OTOC) functions are obtained for a lattice fermion model with
on-site interactions, namely the Falicov-Kimball (FK) model, in the large
dimensional and thermodynamic limit. Our approach is based on the
nonequilibrium dynamical mean-field theory generalized to an extended
Kadanoff-Baym contour. We find that the density-density OTOC is most enhanced
at intermediate coupling around the metal-insulator phase transition. In the
high-temperature limit, the OTOC remains nontrivially finite and
interaction-dependent, even though dynamical charge correlations probed by an
ordinary response function are completely suppressed. We propose an experiment
to measure OTOCs of fermionic lattice systems including the FK and Hubbard
models in ultracold atomic systems.

categories: cond-mat.quant-gas cond-mat.stat-mech cond-mat.str-el hep-th quant-ph


title: Vacuum Radiation Pressure Fluctuations and Barrier Penetration

abstract:
  We apply recent results on the probability distribution for quantum stress
tensor fluctuations to the problem of barrier penetration by quantum particles.
The probability for large stress tensor fluctuations decreases relatively
slowly with increasing magnitude of the fluctuation, especially when the
quantum stress tensor operator has been averaged over a finite time interval.
This can lead to large vacuum radiation pressure fluctuations on charged or
polarizable particles, which can in turn push the particle over a potential
barrier. The rate for this effect depends sensitively upon the details of the
time averaging of the stress tensor operator, which might be determined by
factors such as the shape of the potential. We make some estimates for the rate
of barrier penetration by this mechanism and argue that in some cases this rate
can exceed the rate for quantum tunneling through the barrier. The possibility
of observation of this effect is discussed.


title:
Some bivariate stochastic models arising from group representation
  theory

abstract:
  The aim of this paper is to study some continuous-time bivariate Markov
processes arising from group representation theory. The first component (level)
can be either discrete (quasi-birth-and-death processes) or continuous
(switching diffusion processes), while the second component (phase) will always
be discrete and finite. The infinitesimal operators of these processes will be
now matrix-valued (either a block tridiagonal matrix or a matrix-valued
second-order differential operator). The matrix-valued spherical functions
associated to the compact symmetric pair $(\mathrm{SU}(2)\times \mathrm{SU}(2),
\mathrm{diag} \, \mathrm{SU}(2))$ will be eigenfunctions of these infinitesimal
operators, so we can perform spectral analysis and study directly some
probabilistic aspects of these processes. Among the models we study there will
be rational extensions of the one-server queue and Wright-Fisher models
involving only mutation effects.


title: Canonical superdiffusion and energy fluctuation divergence

abstract:
  We propose a noble physical model obtained from a Hamiltonian with periodic
potential. This model is canonical, reversible and brings about chaotic
superdiffusion with energy fluctuation divergence. The analytical formula of
invariant density can be obtained in some parameter range. In the range it is
proved that the map is Anosov diffeomorphism and the invariant measure is a SRB
measure. We calculate the analytical formula of Lyapunov exponent.


title: Stability of elliptic Harnack inequality

abstract:
  We prove that the elliptic Harnack inequality (on a manifold, graph, or
suitably regular metric measure space) is stable under bounded perturbations,
as well as rough isometries.


title:
On the Safety of Machine Learning: Cyber-Physical Systems, Decision
  Sciences, and Data Products

abstract:
  Machine learning algorithms increasingly influence our decisions and interact
with us in all parts of our daily lives. Therefore, just as we consider the
safety of power plants, highways, and a variety of other engineered
socio-technical systems, we must also take into account the safety of systems
involving machine learning. Heretofore, the definition of safety has not been
formalized in a machine learning context. In this paper, we do so by defining
machine learning safety in terms of risk, epistemic uncertainty, and the harm
incurred by unwanted outcomes. We then use this definition to examine safety in
all sorts of applications in cyber-physical systems, decision sciences, and
data products. We find that the foundational principle of modern statistical
machine learning, empirical risk minimization, is not always a sufficient
objective. Finally, we discuss how four different categories of strategies for
achieving safety in engineering, including inherently safe design, safety
reserves, safe fail, and procedural safeguards can be mapped to a machine
learning context. We then discuss example techniques that can be adopted in
each category, such as considering interpretability and causality of predictive
models, objective functions beyond expected prediction accuracy, human
involvement for labeling difficult or rare examples, and user experience design
of software and open data.


title:
Deformation of matrix-valued orthogonal polynomials related to Gelfand
  pairs

abstract:
  In this paper we present a method to obtain deformations of families of
matrix-valued orthogonal polynomials that are associated to the representation
theory of compact Gelfand pairs. These polynomials have the Sturm-Liouville
property in the sense that they are simultaneous eigenfunctions of a symmetric
second order differential operator and we deform this operator accordingly so
that the deformed families also have the Sturm-Liouville property. Our strategy
is to deform the system of spherical functions that is related to the
matrix-valued orthogonal polynomials and then check that the polynomial
structure is respected by the deformation. Crucial in these considerations is
the full spherical function $\Psi_{0}$, which relates the spherical functions
to the polynomials. We prove an explicit formula for $\Psi_{0}$ in terms of
Krawtchouk polynomials for the Gelfand pair
$(\mathrm{SU}(2)\times\mathrm{SU}(2),\mathrm{diag}(\mathrm{SU}(2)))$. For the
matrix-valued orthogonal polynomials associated to this pair, a deformation was
already available by different methods and we show that our method gives same
results using explicit knowledge of $\Psi_{0}$.
  Furthermore we apply our method to some of the examples of size $2\times2$
for more general Gelfand pairs. We prove that the families related to the
groups $\mathrm{SU}(n)$ are deformations of one another. On the other hand, the
families associated to the symplectic groups $\mathrm{Sp}(n)$ give rise to a
new family with an extra free parameter.


title: Holographic non-Gaussianities in general single-field inflation

abstract:
  We use holographic techniques to compute inflationary non-Gaussianities for
general single-field inflation, including models with a non-trivial sound
speed. In this holographic approach, the inflationary dynamics is captured by a
relevant deformation of the dual conformal field theory (CFT) in the UV, while
the inflationary correlators are computed by conformal perturbation theory. In
this paper, we discuss the effects of higher derivative operators, such as
$(\partial_\mu\phi\partial^\mu\phi)^{m}$, which are known to induce a
non-trivial sound speed and source potentially large non-Gaussianities. We
compute the full inflationary bispectra from the deformed CFT correlators. We
also discuss the squeezed limit of the bispectra from the viewpoint of operator
product expansions. As is generic in the holographic description of inflation,
our power spectrum is blue tilted in the UV region. We extend our bispectrum
computation to the IR region by resumming the conformal perturbations to all
orders. We provide a self-consistent setup which reproduces a red tilted power
spectrum, as well as all possible bispectrum shapes in the slow-roll regime.


title: Iterated Arc Graphs

abstract:
  The arc graph $\delta(G)$ of a digraph $G$ is the digraph with the set of
arcs of $G$ as vertex-set, where the arcs of $\delta(G)$ join consecutive arcs
of $G$. In 1981, Poljak and R\"{o}dl characterised the chromatic number of
$\delta(G)$ in terms of the chromatic number of $G$ when $G$ is symmetric
(i.e., undirected). In contrast, directed graphs with equal chromatic numbers
can have arc graphs with distinct chromatic numbers. Even though the arc graph
of a symmetric graph is not symmetric, we show that the chromatic number of the
iterated arc graph $\delta^k(G)$ still only depends on the chromatic number of
$G$ when $G$ is symmetric.


title:
Bounds for the game coloring number of planar graphs with a specific
  girth

abstract:
  Let ${\rm col_g}(G)$ be the game coloring number of a given graph $G.$ Define
the game coloring number of a family of graphs $\mathcal{H}$ as ${\rm
col_g}(\mathcal{H}) := \max\{{\rm col_g}(G):G \in \mathcal{H}\}.$ Let
$\mathcal{P}_k$ be the family of planar graphs of girth at least $k.$ We show
that ${\rm col_g}(\mathcal{P}_7) \leq 5.$ This result extends a result about
the coloring number by Wang and Zhang {WZ11} (${\rm col_g}(\mathcal{P}_8) \leq
5).$ We also show that these bounds are sharp by constructing a graph $G$ where
$G \in {\rm col_g}(\mathcal{P}_k) \geq 5$ for each $k \leq 8$ such that ${\rm
col_g}(G)=5.$ As a consequence, ${\rm col_g}(\mathcal{P}_k) = 5$ for $k =7,8.$


title: Coherent states in projected Hilbert spaces

abstract:
  Coherent states in a projected Hilbert space have many useful properties.
When there are conserved quantities, a representation of the entire Hilbert
space is not necessary. The same issue arises when conditional observations are
made with post-selected measurement results. In these cases, only a part of the
Hilbert space needs to be represented, and one can define this restriction by
way of a projection operator. Here coherent state bases and normally-ordered
phase-space representations are introduced for treating such projected Hilbert
spaces, including existence theorems and dynamical equations. These techniques
are very useful in studying novel optical or microwave integrated photonic
quantum technologies, such as boson sampling or Josephson quantum computers. In
these cases states become strongly restricted due to inputs, nonlinearities or
conditional measurements. This paper focuses on coherent phase states, which
have especially simple properties. Practical applications are reported on
calculating recurrences in anharmonic oscillators, the effects of arbitrary
phase-noise on Schrodinger cat fringe visibility, and on boson sampling
interferometry for large numbers of modes.


title: Monotonicity of $p$-norms of multiple operators via unitary swivels

abstract:
  Following the various statements of [DW16] to their logical conclusion, this
note explicitly argues the following statement, implicit in [DW16]: for
positive semi-definite operators $C_{1},\ldots,\,C_{L} $, a unitary $V_{C_{i}}$
commuting with $C_{i}$, and $p\geq1$, the quantity $$
\max_{V_{C_{1}},\ldots,V_{C_{L}}}\left\Vert C_{1}^{1/p}V_{C_{1}}\cdots
C_{L}^{1/p}V_{C_{L}}\right\Vert _{p}^{p} $$ is monotone non-increasing with
respect to $p$. The idea from [DW16] is that by allowing unitary swivels
connecting a long chain of positive semi-definite operators together, we can
establish such a statement, which might not hold generally without the presence
of the unitary swivels. Other related statements follow directly from [DW16] as
well, being implicit there, and are given explicitly in this note.


title:
Sharp interface limit for stochastically perturbed mass conserving
  Allen-Cahn equation

abstract:
  This paper studies the sharp interface limit for a mass conserving Allen-Cahn
equation added an external noise and derives a stochastically perturbed mass
conserving mean curvature flow in the limit. The stochastic term destroys the
precise conservation law, instead the total mass changes like a Brownian motion
in time. For our equation, the comparison argument does not work, so that to
study the limit we adopt the asymptotic expansion method, which extends that
for deterministic equations used in Chen et al. [3]. Differently from the
deterministic case, each term except the leading term appearing in the
expansion of the solution in a small parameter $\epsilon$ diverges as
$\epsilon$ tends to $0$, since our equation contains the noise which converges
to a white noise and the products or the powers of the white noise diverge. To
derive the error estimate for our asymptotic expansion, we need to establish
the Schauder estimate for a diffusion operator with coefficients determined
from higher order derivatives of the noise and their powers. We show that one
can choose the noise sufficiently mild in such a manner that it converges to
the white noise and at the same time its diverging speed is slow enough for
establishing a necessary error estimate.


title: Koszul Factorization and the Cohen-Gabber Theorem

abstract:
  We present a sharpened version of the Cohen-Gabber theorem for
equicharacteristic, complete local domains (A,m,k) with algebraically closed
residue field and dimension d > 0. Namely, we show that for any prime number p,
Spec(A) admits a dominant, finite map to Spec(k[[X_1,...,X_d]]) with generic
degree relatively prime to p. Our result follows from Gabber's original
theorem, elementary Hilbert-Samuel multiplicity theory, and a "factorization"
of the map induced on the Grothendieck group G_0(A) by the Koszul complex.


title:
Advancing parabolic operators in thermodynamic MHD models: Explicit
  super time-stepping versus implicit schemes with Krylov solvers

abstract:
  We explore the performance and advantages/disadvantages of using
unconditionally stable explicit super time-stepping (STS) algorithms versus
implicit schemes with Krylov solvers for integrating parabolic operators in
thermodynamic MHD models of the solar corona. Specifically, we compare the
second-order Runge-Kutta Legendre (RKL2) STS method with the implicit backward
Euler scheme computed using the preconditioned conjugate gradient (PCG) solver
with both a point-Jacobi and a non-overlapping domain decomposition ILU0
preconditioner. The algorithms are used to integrate anisotropic Spitzer
thermal conduction and artificial kinematic viscosity at time-steps much larger
than classic explicit stability criteria allow. A key component of the
comparison is the use of an established MHD model (MAS) to compute a real-world
simulation on a large HPC cluster. Special attention is placed on the parallel
scaling of the algorithms. It is shown that, for a specific problem and model,
the RKL2 method is comparable or surpasses the implicit method with PCG solvers
in performance and scaling, but suffers from some accuracy limitations. These
limitations, and the applicability of RKL methods are briefly discussed.


title: Lepton flavor violation in the Simplest Little Higgs model

abstract:
  Little Higgs Models are a possible elegant solution to the hierarchy problem
on the Higgs mass. As they predict naturally small deviations with respect to
SM results, they are in agreement with all current experimental data. In this
contribution, we review lepton flavor violation in the Simplest Little Higgs
model focusing on semileptonic lepton flavor violating tau decays (where some
new results are presented) and $H\to\ell\ell'$. Within this model, the most
promising decay channels for discovering lepton flavor violation are $\mu\to e$
conversion in nuclei, $\mu\to e\gamma^{(*)}$, $\tau\to (e/\mu)\gamma$ and
$\tau\to (e/\mu) (\pi^+\pi^-/\rho)$.


title: 10-millisecond Computing

abstract:
  Despite computation becomes much complex on data with an unprecedented scale,
we argue computers or smart devices should and will consistently provide
information and knowledge to human being in the order of a few tens
milliseconds. We coin a new term 10-millisecond computing to call attention to
this class of workloads. 10-millisecond computing raises many challenges for
both software and hardware stacks. In this paper, using a typical
workload-memcached on a 40-core server (a main-stream server in near future),
we quantitatively measure 10-ms computing's challenges to conventional
operating systems. For better communication, we propose a simple metric-outlier
proportion to measure quality of service: for N completed requests or jobs, if
M jobs or requests' latencies exceed the outlier threshold t, the outlier
proportion is M/N . For a 1K-scale system running Linux (version 2.6.32), LXC
(version 0.7.5) or XEN (version 4.0.0), respectively, we surprisingly find that
so as to reduce the service outlier proportion to 10% (10% users will feel QoS
degradation), the outlier proportion of a single server has to be reduced by
871X, 2372X, 2372X accordingly. Also, we discuss the possible design spaces of
10-ms computing systems from perspectives of datacenter architectures,
networking, OS and scheduling, and benchmarking.


title: Random access codes and non-local resources

abstract:
  It is known that a PR-BOX (PR), a non-local resource and $(2\rightarrow 1)$
random access code (RAC), a functionality (wherein Alice encodes 2 bits into 1
bit message and Bob learns one of randomly chosen Alice's inputs) are
equivalent under the no-signaling condition. In this work we introduce
generalizations to PR and $(2\rightarrow 1)$ RAC and study their
inter-convertibility. We introduce generalizations based on the number of
inputs provided to Alice, $B_n$-BOX and $(n\rightarrow 1)$ RAC. We show that a
$B_n$-BOX is equivalent to a no-signaling $(n\rightarrow 1)$ RACBOX (RB).
Further we introduce a signaling $(n\rightarrow 1)$ RB which cannot simulate a
$B_n$-BOX. Finally to quantify the same we provide a resource inequality
between $(n\rightarrow 1)$ RB and $B_n$-BOX, and show that it is saturated. As
an application we prove that one requires atleast $(n-1)$ PRs supplemented with
a bit of communication to win a $(n\rightarrow 1)$ RAC. We further introduce
generalizations based on the dimension of inputs provided to Alice and the
message she sends, $B_n^d(+)$-BOX, $B_n^d(-)$-BOX and $(n\rightarrow 1,d)$ RAC
($d>2$). We show that no-signaling condition is not enough to enforce strict
equivalence in the case of $d>2$. We introduce classes of no-signaling
$(n\rightarrow 1,d)$ RB, one which can simulate $B_n^d(+)$-BOX, second which
can simulate $B_n^d(-)$-BOX and third which cannot simulate either. Finally to
quantify the same we provide a resource inequality between $(n\rightarrow 1,d)$
RB and $B_n^d(+)$-BOX, and show that it is saturated.


title:
Solving the spin-2 Gross-Pitaevskii equation using exact nonlinear
  dynamics and symplectic composition

abstract:
  We develop numerical methods for solving the spin-2 Gross-Pitaevskii
equation. The basis of our work is a two-way splitting of this evolution
equation that leads to two exactly solvable subsystems. Utilizing second-order
and fourth-order composition schemes we realize two fully symplectic
integration algorithms, the first such algorithms for evolving spin-2
condensates. We demonstrate the accuracy of these algorithms against other
methods on application to an exact continuous wave solution that we derive.


title: Information inefficiency in a random linear economy model

abstract:
  We study the effects of introducing information inefficiency in a model for a
random linear economy with a representative consumer. This is done by
considering statistical, instead of classical, economic general equilibria.
Employing two different approaches we show that inefficiency increases the
consumption set of a consumer but decreases her expected utility. In this
scenario economic activity grows while welfare shrinks, that is the opposite of
the behavior obtained by considering a rational consumer.


title: Generalized Random Forests

abstract:
  We propose generalized random forests, a method for non-parametric
statistical estimation based on random forests (Breiman, 2001) that can be used
to fit any quantity of interest identified as the solution to a set of local
moment equations. Following the literature on local maximum likelihood
estimation, our method considers a weighted set of nearby training examples;
however, instead of using classical kernel weighting functions that are prone
to a strong curse of dimensionality, we use an adaptive weighting function
derived from a forest designed to express heterogeneity in the specified
quantity of interest. We propose a flexible, computationally efficient
algorithm for growing generalized random forests, develop a large sample theory
for our method showing that our estimates are consistent and asymptotically
Gaussian, and provide an estimator for their asymptotic variance that enables
valid confidence intervals. We use our approach to develop new methods for
three statistical tasks: non-parametric quantile regression, conditional
average partial effect estimation, and heterogeneous treatment effect
estimation via instrumental variables. A software implementation, grf for R and
C++, is available from CRAN.


title:
Interacting dark energy models in Cosmology and large-scale structure
  observational tests

abstract:
  Modern Cosmology offers us a great understanding of the universe with
striking precision, made possible by the modern technologies of the newest
generations of telescopes. The standard cosmological model, however, is not
absent of theoretical problems and open questions. One possibility that has
been put forward is the existence of a coupling between dark sectors. The idea
of an interaction between the dark components could help physicists understand
why we live in an epoch of the universe where dark matter and dark energy are
comparable in terms of energy density, which can be regarded as a coincidence
given that their time evolutions are completely different.
  We introduce the interaction phenomenologically and proceed to test models of
interaction with observations of redshift-space distortions. In a flat universe
composed only of those two fluids, we consider separately two forms of
interaction, through terms proportional to the densities of both dark energy
and dark matter. An analytic expression for the growth rate approximated as $f
= \Omega_{\mathrm{DM}}^{\gamma}$, where $\Omega_{\mathrm{DM}}$ is the
percentage contribution from the dark matter to the content of the universe and
$\gamma$ is the growth index, is derived in terms of the interaction strength
and of other parameters of the model in the first case, while for the second
model we show that a non-zero interaction cannot be accommodated by the index
growth approximation. The successful expressions obtained are then used to
compare the predictions with growth of structure observational data in a MCMC
code.
  We also employ observations of galaxy clusters to assess their virial state
via the modified Layzer-Irvine equation in order to detect signs of an
interaction, obtaining measurements of observed virial ratios, interaction
strength, rest virial ratio and departure from equilibrium for a set of
clusters. [abridged]


title: The dynamics of copper intercalated molybdenum ditelluride

abstract:
  Layered transition metal dichalcogenides are emerging as key materials in
nanoelectronics and energy applications. Predictive models to understand their
growth, thermomechanical properties and interactions with metals are needed in
order to accelerate their incorporation into commercial products. Interatomic
potentials enable large-scale atomistic simulations at the device level, beyond
the range of applications of first principle methods. We present a ReaxFF
reactive force field to describe molybdenum ditelluride and its interactions
with copper. We optimized the force field parameters to describe the properties
of layered MoTe2 in various phases, the intercalation of Cu atoms and clusters
within its van der Waals gap, including a proper description of energetics,
charges and mechanical properties. The training set consists of an extensive
set of first principle calculations computed from density functional theory. We
use the force field to study the adhesion of a single layer MoTe2 on a Cu(111)
surface and the results are in good agreement with density functional theory,
even though such structures were not part of the training set. We characterized
the mobility of the Cu ions intercalated into MoTe2 under the presence of an
external electric fields via molecular dynamics simulations. The results show a
significant increase in drift velocity for electric fields of approximately 0.4
V/A and that mobility increases with Cu ion concentration.


title:
Statistical properties of the maximal entropy measure for partially
  hyperbolic attractors

abstract:
  We show the existence and uniqueness of the maximal entropy probability
measure for partially hyperbolic diffeomorphisms which are semi-conjugate to
nonuniformly expanding maps. Using the theory of projective metric on cones we
then prove exponential decay of correlations for H\"older continuous
observables and the central limit theorem for the maximal entropy probability
measure. Moreover, for systems derived from solenoid we also prove the
statistical stability for the maximal entropy probability measure. Finally, we
use such techniques to obtain similar results in a context containing partially
hyperbolic systems derived from Anosov. Paper published in ETDS in Jan. 2016.


title:
Geometric structures modeled on smooth projective horospherical
  varieties of Picard number one

abstract:
  Geometric structures modeled on rational homogeneous manifolds are studied to
characterize rational homogeneous manifolds and to prove their deformation
rigidity. To generalize these characterizations and deformation rigidity
results to quasihomogeneous varieties, we first study horospherical varieties
and geometric structures modeled on horospherical varieties. Using Cartan
geometry, we prove that a geometric structure modeled on a smooth projective
horospherical variety of Picard number one is locally equivalent to the
standard geometric structure when the geometric structure is defined on a Fano
manifold of Picard number one.


title: On the Cycle Space of a Random Graph

abstract:
  Write $\mathcal{C}(G)$ for the cycle space of a graph $G$,
$\mathcal{C}_\kappa(G)$ for the subspace of $\mathcal{C}(G)$ spanned by the
copies of the $\kappa$-cycle $C_\kappa$ in $G$, $\mathcal{T}_\kappa$ for the
class of graphs satisfying $\mathcal{C}_\kappa(G)=\mathcal{C}(G)$, and
$\mathcal{Q}_\kappa$ for the class of graphs each of whose edges lies in a
$C_\kappa$. We prove that for every odd $\kappa \geq 3$ and $G=G_{n,p}$,
\[\max_p \, \Pr(G \in \mathcal{Q}_\kappa \setminus \mathcal{T}_\kappa)
\rightarrow 0;\] so the $C_\kappa$'s of a random graph span its cycle space as
soon as they cover its edges. For $\kappa=3$ this was shown by DeMarco, Hamm
and Kahn (2013).


title: Prominent role of spin-orbit coupling in FeSe

abstract:
  In most existing theories for iron-based superconductors, spin-orbit coupling
(SOC) has been assumed insignificant. Even though recent experiments have
revealed an influence of SOC on the electronic band structure, whether SOC
fundamentally affects magnetism and superconductivity remains an open question.
Here we use spin-polarised inelastic neutron scattering to show that collective
low-energy spin fluctuations in the orthorhombic (or "nematic") phase of FeSe
possess nearly no in-plane component. Such spin-space anisotropy can only be
caused by SOC. It is present over an energy range greater than the
superconducting gap 2$\Delta _\mathrm{sc}$ and gets fully inherited in the
superconducting state, resulting in a distinct $c$-axis polarised "spin
resonance". Our result demonstrates the importance of SOC in defining the
low-energy spin excitations in FeSe, which helps to elucidate the nearby
magnetic instabilities and the debated interplay between spin and orbital
degrees of freedom. The prominent role of SOC also implies a possible unusual
nature of the superconducting state.


title: Riemannian $M$-spaces with homogeneous geodesics

abstract:
  We investigate homogeneous geodesics in a class of homogeneous spaces called
$M$-spaces, which are defined as follows. Let $G/K$ be a generalized flag
manifold with $K=C(S)=S\times K_1$, where $S$ is a torus in a compact simple
Lie group $G$ and $K_1$ is the semisimple part of $K$. Then the {\it associated
$M$-space} is the homogeneous space $G/K_1$. These spaces were introduced and
studied by H.C. Wang in 1954. We prove that for various classes of $M$-spaces
the only g.o. metric is the standard metric. For other classes of $M$-spaces we
give either necessary, or necessary and sufficient conditions, so that a
$G$-invariant metric on $G/K_1$ is a g.o. metric. The analysis is based on
properties of the isotropy representation $\mathfrak{m}=\mathfrak{m}_1\oplus
\cdots\oplus \mathfrak{m}_s$ of the flag manifold $G/K$ (as Ad$(K)$-modules)
and corresponding decomposition
$\mathfrak{n}=\mathfrak{s}\oplus\mathfrak{m}_1\oplus \cdots\oplus
\mathfrak{m}_s$ of the tangent space of the $M$-space $G/K_1$ (as
Ad$(K_1)$-modules).


title:
Comparison of Geant4 multiple Coulomb scattering models with theory for
  radiotherapy protons

abstract:
  Usually, Monte Carlo models are validated against experimental data. However,
models of multiple Coulomb scattering (MCS) in the Gaussian approximation are
exceptional in that we have theories which are probably more accurate than the
experiments which have, so far, been done to test them. In problems directly
sensitive to the distribution of angles leaving the target, the relevant theory
is the Moliere/Fano/Hanson variant of Moliere theory. For transverse spreading
of the beam in the target itself, the theory of Preston and Koehler holds.
  Therefore, in this paper we compare Geant4 simulations, using the Urban and
Wentzel models of MCS, with theory rather than experiment, revealing trends
which would otherwise be obscured by experimental scatter. For medium-energy
(radiotherapy) protons, and low-Z (water-like) target materials, Wentzel
appears to be better than Urban in simulating the distribution of outgoing
angles. For beam spreading in the target itself, the two models are essentially
equal.


title:
Exact renormalization of the photino mass in softly broken ${\cal N}=1$
  SQED with $N_f$ flavors regularized by higher derivatives

abstract:
  We consider the softly broken ${\cal N}=1$ supersymmetric electrodynamics,
regularized by higher derivatives. For this theory we demonstrate that the
renormalization of the photino mass is determined by integrals of double total
derivatives in the momentum space in all orders. Consequently, it is possible
to derive the NSVZ-like exact relation between the photino mass anomalous
dimension and the anomalous dimension of the matter superfields in the rigid
theory by direct summation of supergraphs. It is important that both these
renormalization group functions are defined in terms of the bare coupling
constant, so that the considered NSVZ-like relation is valid independently of
the subtraction scheme in the case of using the higher derivative
regularization. The factorization of integrals defining the photino mass
renormalization into integrals of double total derivatives is verified by an
explicit two-loop calculation.


title: A Quantitative Local Limit Theorem for Triangles in Random Graphs

abstract:
  In this paper we prove a quantiative local limit theorem for the distribution
of the number of triangles in the Erd\H{o}s-Renyi random graph $G(n,p)$, for a
fixed $p\in (0,1)$. This proof is an extension of the previous work of Gilmer
and Kopparty, who proved that the local limit theorem held asymptotically for
triangles. Our work gives bounds on the $\ell^1$ and $\ell^\infty$ distance of
the triangle distribution from a suitable discrete normal.


title:
MopEye: Monitoring Per-app Network Performance with Zero Measurement
  Traffic

abstract:
  Mobile network performance measurement is important for understanding mobile
user experience, problem diagnosis, and service comparison. A number of
crowdsourcing measurement apps (e.g., MobiPerf [4, 6] and Netalyzr [5, 7]) have
been embarked for the last few years. Unlike existing apps that use active
measurement methods, we employ a novel passive-active approach to continuously
monitor per-app network performance on unrooted smartphones without injecting
additional network traffic. By leveraging the VpnService API on Android,
MopEye, our measurement app, intercepts all network traffic and then relays
them to their destinations using socket APIs. Therefore, not only MopEye can
measure the round-trip time accurately, it can do so without injecting
additional traffic. As a result, the bandwidth cost (and monetary cost of data
usage) for conducting such a measurement is eliminated, and the measurement can
be conducted free of user intervention. Our evaluation shows that MopEye's RTT
measurement is very close to result of tcpdump and is more accurate than
MobiPerf. We have used MopEye to conduct a one-week measurement revealing
multiple interesting findings on different apps' performance.