title: Generalized Similarity for Accretion/Decretion Disks

abstract:
  Decretion (or external) disks are gas disks freely expanding to large radii
due to their internal stresses. They are expected to naturally arise in tidal
disruption events, around Be stars, in mass-losing post main sequence binaries,
as a result of supernova fallback, etc. Their evolution is theoretically
understood in two regimes: when the central object does not exert torque on the
disk (a standard assumption for conventional accretion disks) or when no mass
inflow (or outflow) occurs at the disk center. However, many astrophysical
objects - circumbinary disks, Be stars, neutron stars accreting in a propeller
regime, etc. - feature non-zero torque simultaneously with the non-zero
accretion (or ejection of mass) at the disk center. We provide a general
description for the evolution of such disks (both linear and non-linear) in the
self-similar regime, to which the disk should asymptotically converge with
time. We identify a similarity parameter $\lambda$, which is uniquely related
to the degree, to which the central mass accretion is suppressed by the
non-zero central torque. The known decretion disk solutions correspond to the
two discrete values of $\lambda$, while our new solutions cover a continuum of
its physically allowed values, corresponding to either accretion or mass
ejection by the central object. A direct relationship between $\lambda$ and
central $\dot M$ and torque is also established. We describe the time evolution
of the various disk characteristics for different $\lambda$, and show that the
observable properties (spectrum and luminosity evolution) of the decretion
disks are in general different from the standard accretion disks with no
central torque.


title: Rescuing a Quantum Phase Transition with Quantum Noise

abstract:
  We show that placing a quantum system in contact with an environment can
enhance non-Fermi-liquid correlations, rather than destroy quantum effects as
is typical. The system consists of two quantum dots in series with two leads;
the highly resistive leads couple charge flow through the dots to the
electromagnetic environment, the source of quantum noise. While the charge
transport inhibits a quantum phase transition, the quantum noise reduces charge
transport and restores the transition. We find a non-Fermi-liquid intermediate
fixed point for all strengths of the noise. For strong noise, it is similar to
the intermediate fixed point of the two-impurity Kondo model.


title: A Hard X-ray Study of the Normal Star-Forming Galaxy M83 with NuSTAR

abstract:
  We present results from sensitive, multi-epoch NuSTAR observations of the
late-type star-forming galaxy M83 (d=4.6 Mpc), which is the first investigation
to spatially resolve the hard (E>10 keV) X-ray emission of this galaxy. The
nuclear region and ~ 20 off-nuclear point sources, including a previously
discovered ultraluminous X-ray (ULX) source, are detected in our NuSTAR
observations. The X-ray hardnesses and luminosities of the majority of the
point sources are consistent with hard X-ray sources resolved in the starburst
galaxy NGC 253. We infer that the hard X-ray emission is most likely dominated
by intermediate accretion state black hole binaries and neutron star low-mass
X-ray binaries (Z-sources). We construct the X-ray binary luminosity function
(XLF) in the NuSTAR band for an extragalactic environment for the first time.
The M83 XLF has a steeper XLF than the X-ray binary XLF in NGC 253, consistent
with previous measurements by Chandra at softer X-ray energies. The NuSTAR
integrated galaxy spectrum of M83 drops quickly above 10 keV, which is also
seen in the starburst galaxies NGC253, NGC 3310 and NGC 3256. The NuSTAR
observations constrain any AGN to be either highly obscured or to have an
extremely low luminosity of $_{\sim}^<$10$^{38}$ erg/s (10-30 keV), implying it
is emitting at a very low Eddington ratio. An X-ray point source consistent
with the location of the nuclear star cluster with an X-ray luminosity of a few
times 10$^{38}$ erg/s may be a low-luminosity AGN but is more consistent with
being an X-ray binary.


title: Precision Stellar Astrophysics in the Kepler Era

abstract:
  The study of fundamental properties (such as temperatures, radii, masses, and
ages) and interior processes (such as convection and angular momentum
transport) of stars has implications on various topics in astrophysics, ranging
from the evolution of galaxies to understanding exoplanets. In this
contribution I will review the basic principles of two key observational
methods for constraining fundamental and interior properties of single field
stars: the study stellar oscillations (asteroseismology) and optical
long-baseline interferometry. I will highlight recent breakthrough discoveries
in asteroseismology such as the measurement of core rotation rates in red
giants and the characterization of exoplanet systems. I will furthermore
comment on the reliability of interferometry as a tool to calibrate indirect
methods to estimate fundamental properties, and present a new angular diameter
measurement for the exoplanet host star HD219134 which demonstrates that
diameters for stars which are relatively well resolved (~> 1 mas for the K
band) are consistent across different instruments. Finally I will discuss the
synergy between asteroseismology and interferometry to test asteroseismic
scaling relations, and give a brief outlook on the expected impact of
space-based missions such as K2, TESS and Gaia.


title:
On the reversibitity of the Meissner effect and the angular momentum
  puzzle

abstract:
  It is generally believed that the laws of thermodynamics govern
superconductivity as an equilibrium state of matter. Here we point out that
within the conventional BCS-London description of the normal-superconductor
transition in the presence of a magnetic field, the transition cannot be
reversible, in contradiction with the thermodynamic description and with
experiments. This indicates that the conventional theory of superconductivity
is internally inconsistent. We argue that to describe a reversible transition
it is necessary to assume that charge transfer occurs across the
normal-superconductor phase boundary, as proposed in the theory of hole
superconductiviy. This provides also a solution to the angular momentum puzzle
pointed out in previous work. Our explanation can only apply if the current
carriers in the normal state are holes. An experimental test of these ideas is
proposed.


title: Interacting social processes on interconnected networks

abstract:
  We propose and study a model for the interplay between two different
dynamical processes --one for opinion formation and the other for decision
making-- on two interconnected networks $A$ and $B$. The opinion dynamics on
network $A$ corresponds to that of the M-model, where the state of each agent
can take one of four possible values ($S=-2,-1,1,2$), describing its level of
agreement on a given issue. The likelihood to become an extremist ($S=\pm 2$)
or a moderate ($S=\pm 1$) is controlled by a reinforcement parameter $r \ge 0$.
The decision making dynamics on network $B$ is akin to that of the
Abrams-Strogatz model, where agents can be either in favor ($S=+1$) or against
($S=-1$) the issue. The probability that an agent changes its state is
proportional to the fraction of neighbors that hold the opposite state raised
to a power $\beta$. Starting from a polarized case scenario in which all agents
of network $A$ hold positive orientations while all agents of network $B$ have
a negative orientation, we explore the conditions under which one of the
dynamics prevails over the other, imposing its initial orientation. We find
that, for a given value of $\beta$, the two-network system reaches a consensus
in the positive state (initial state of network $A$) when the reinforcement
overcomes a crossover value $r^*(\beta)$, while a negative consensus happens
for $r<r^*(\beta)$. In the $r-\beta$ phase space, the system displays a
transition at a critical threshold $\beta_c$, from a coexistence of both
orientations for $\beta<\beta_c$ to a dominance of one orientation for
$\beta>\beta_c$. We develop an analytical mean-field approach that gives an
insight into these regimes and shows that both dynamics are equivalent along
the crossover line $(r^*,\beta^*)$.


title: On a limit of the method of Tashkinov trees for edge-colouring

abstract:
  The main technique used to edge-colour graphs requiring $\Delta+2$ or more
colours is the method of Tashkinov trees. We present a specific limit to this
method, in terms of Kempe changes. We also provide a new Tashkinov tree
extension.


title:
A Survey of Motion Planning and Control Techniques for Self-driving
  Urban Vehicles

abstract:
  Self-driving vehicles are a maturing technology with the potential to reshape
mobility by enhancing the safety, accessibility, efficiency, and convenience of
automotive transportation. Safety-critical tasks that must be executed by a
self-driving vehicle include planning of motions through a dynamic environment
shared with other vehicles and pedestrians, and their robust executions via
feedback control. The objective of this paper is to survey the current state of
the art on planning and control algorithms with particular regard to the urban
setting. A selection of proposed techniques is reviewed along with a discussion
of their effectiveness. The surveyed approaches differ in the vehicle mobility
model used, in assumptions on the structure of the environment, and in
computational requirements. The side-by-side comparison presented in this
survey helps to gain insight into the strengths and limitations of the reviewed
approaches and assists with system level design choices.


title:
Dynamics of spherical distributions of charge with small internal
  dipolar motion

abstract:
  This paper extends the Lorentz-Abraham model of an electron (i.e. the
equations of motion for a small spherical shell of charge, which is rigid in
its proper frame) to treat a small spherically symmetric charge distribution,
allowing for small internal dipolar motion. This is done by dividing the
distribution into thin spherical shells (in the continuum limit), and tracking
the interactions between shells. Dipolar motion of each constituent spherical
shell is allowed along the net dipole moment, but higher order
multipole-moments are ignored. The amplitude of dipolar motion of each
spherical shell is assumed to be linearly proportional to the net dipole
moment. Under these assumptions, low velocity equations of motion are
determined for both the center-of-mass motion and net dipolar motion of the
distribution. This is then generalized to arbitrary (relativistic)
center-of-mass velocity and acceleration, assuming the motion of individual
shells is completely in phase or out of phase with the net dipole moment.


title:
Classical electrodynamics in a space with spin noncommutativity of
  coordinates

abstract:
  We propose a new relativistic Lorentz-invariant spin-noncommutative algebra.
Using the Weyl ordering of noncommutative position operators, we build an
analogue of the Moyal-Groenewald product for the proposed algebra. The Lagrange
function of an electromagnetic field in the space with spin noncommutativity is
constructed. In such a space electromagnetic field becomes non-abelian. A gauge
transformation law of this field is also obtained. Exact nonlinear field
equations of noncommutative electromagnetic field are derived from the least
action principle. Within the perturbative approach we consider field of a point
charge in a constant magnetic field and interaction of two plane waves. An
exact solution of a plane wave propagation in a constant magnetic and electric
fields is found.


title: Distribution-free Detection of a Submatrix

abstract:
  We consider the problem of detecting the presence of a submatrix with
larger-than-usual values in a large data matrix. This problem was considered in
(Butucea and Ingster, 2013) under a one-parameter exponential family, and one
of the test they analyzed is the scan test. Taking a nonparametric stance, we
show that a calibration by permutation leads to the same (first-order)
asymptotic performance. This is true for the two types of permutations we
consider. We also study the corresponding rank-based variants and precisely
quantify the loss in asymptotic power.


title: Quantum Shannon Theory

abstract:
  This is the 10th and final chapter of my book on Quantum Information, based
on the course I have been teaching at Caltech since 1997. An earlier version of
this chapter (originally Chapter 5) has been available on the course website
since 1998, but this version is substantially revised and expanded. Topics
covered include classical Shannon theory, quantum compression, quantifying
entanglement, accessible information, and using the decoupling principle to
derive achievable rates for quantum protocols. This is a draft, pre-publication
copy of Chapter 10, which I will continue to update. See the URL on the title
page for further updates and drafts of other chapters, and please send me an
email if you notice errors.


title: Learning Local Dependence In Ordered Data

abstract:
  In many applications, data come with a natural ordering. This ordering can
often induce local dependence among nearby variables. However, in complex data,
the width of this dependence may vary, making simple assumptions such as a
constant neighborhood size unrealistic. We propose a framework for learning
this local dependence based on estimating the inverse of the Cholesky factor of
the covariance matrix. Penalized maximum likelihood estimation of this matrix
yields a simple regression interpretation for local dependence in which
variables are predicted by their neighbors. Our proposed method involves
solving a convex, penalized Gaussian likelihood problem with a hierarchical
group lasso penalty. The problem decomposes into independent subproblems which
can be solved efficiently in parallel using first-order methods. Our method
yields a sparse, symmetric, positive definite estimator of the precision
matrix, encoding a Gaussian graphical model. We derive theoretical results not
found in existing methods attaining this structure. In particular, our
conditions for signed support recovery and estimation consistency rates in
multiple norms are as mild as those in a regression problem. Empirical results
show our method performing favorably compared to existing methods. We apply our
method to genomic data to flexibly model linkage disequilibrium. Our method is
also applied to improve the performance of discriminant analysis in sound
recording classification.


title:
Quantum circuit dynamics via path integrals: Is there a classical action
  for discrete-time paths?

abstract:
  It is straightforward to give a sum-over-paths expression for the transition
amplitudes of a quantum circuit as long as the gates in the circuit are
balanced, where to be balanced is to have all nonzero transition amplitudes of
equal magnitude. Here we consider the question of whether, for such circuits,
the relative phases of different discrete-time paths through the configuration
space can be defined in terms of a classical action, as they are for
continuous-time paths. We show how to do so for certain kinds of quantum
circuits, namely, Clifford circuits where the elementary systems are
continuous-variable systems or discrete systems of odd-prime dimension. These
types of circuit are distinguished by having phase-space representations that
serve to define their classical counterparts. For discrete systems, the
phase-space coordinates are also discrete variables. We show that for each gate
in the generating set, one can associate a symplectomorphism on the phase-space
and to each of these one can associate a generating function, defined on two
copies of the configuration space. For discrete systems, the latter association
is achieved using tools from algebraic geometry. Finally, we show that if the
action functional for a discrete-time path through a sequence of gates is
defined using the sum of the corresponding generating functions, then it yields
the correct relative phases for the path-sum expression. These results are
likely to be relevant for quantizing physical theories where time is
fundamentally discrete, characterizing the classical limit of discrete-time
quantum dynamics, and proving complexity results for quantum circuits.


title: The Cheeger constant of a quantum graph

abstract:
  We review the theory of Cheeger constants for graphs and quantum graphs and
their present and envisaged applications.


title: Perturbatively stable observables in heavy-quark leptoproduction

abstract:
  We study the perturbative and parametric stability of the QCD predictions for
the Callan-Gross ratio $R(x,Q^2)=F_L/F_T$ and azimuthal $\cos(2\varphi)$
asymmetry, $A(x,Q^2)$, in heavy-quark leptoproduction. We review the available
theoretical results for these quantities and conclude that, contrary to the
production cross sections, the ratios $R(x,Q^2)$ and $A(x,Q^2)$ are stable
under radiative QCD corrections in wide region of the variables $x$ and $Q^2$.
This implies that large radiative contributions to the structure functions
cancel each other in the ratios $R(x,Q^2)$ and $A(x,Q^2)$ with good accuracy.
  Then we consider some experimental and phenomenological applications of the
observed perturbative stability. We provide compact analytic predictions for
$R(x,Q^2)$ and azimuthal $\cos(2\varphi)$ asymmetry in the case of low $x\ll
1$. It is demonstrated that our obtained results will be useful in the
extraction of the structure functions from measurements of the reduced cross
sections. Finally, we analyze the properties of $R(x,Q^2)$ and $A(x,Q^2)$
within the variable-flavor-number scheme (VFNS) of QCD. We conclude that the
Callan-Gross ratio and azimuthal asymmetry are perturbatively stable but
sensitive to resummation of the mass logarithms of the type
$\alpha_{s}\ln\left( Q^{2}/m^{2}\right)$. For this reason, the quantities
$R(x,Q^2)$ and $A(x,Q^2)$ will be good probes of the heavy-quark content of the
proton.


title:
Observation of the superconducting proximity effect in the surface state
  of SmB6 thin films

abstract:
  The proximity effect at the interface between a topological insulator (TI)
and a superconductor is predicted to give rise to chiral topological
superconductivity and Majorana fermion excitations. In most TIs studied to
date, however, the conducting bulk states have overwhelmed the transport
properties and precluded the investigation of the interplay of the topological
surface state and Cooper pairs. Here, we demonstrate the superconducting
proximity effect in the surface state of SmB6 thin films which display bulk
insulation at low temperatures. The Fermi velocity in the surface state deduced
from the proximity effect is found to be as large as 10^5 m/s, in good
agreement with the value obtained from a separate transport measurement. We
show that high transparency between the TI and a superconductor is crucial for
the proximity effect. The finding here opens the door to investigation of
exotic quantum phenomena using all-thin-film multilayers with high-transparency
interfaces.


title: Toric braids and $(m,n)$-parking functions

abstract:
  The Dyck path algebra construction of Carlsson and Mellit from
arXiv:1508.06239 is interpreted as a representation of "the positive part" of
the group of toric braids. Then certain sums over $(m,n)$-parking functions are
related to evaluations of this representation on some special braids. The
compositional $(km,kn)$-shuffle conjecture of Bergeron, Garsia, Leven and Xin
from arXiv:1404.4616 is then shown to be a corollary of this relation.


title:
Modeling the Contribution of Central Versus Peripheral Vision in Scene,
  Object, and Face Recognition

abstract:
  It is commonly believed that the central visual field is important for
recognizing objects and faces, and the peripheral region is useful for scene
recognition. However, the relative importance of central versus peripheral
information for object, scene, and face recognition is unclear. In a behavioral
study, Larson and Loschky (2009) investigated this question by measuring the
scene recognition accuracy as a function of visual angle, and demonstrated that
peripheral vision was indeed more useful in recognizing scenes than central
vision. In this work, we modeled and replicated the result of Larson and
Loschky (2009), using deep convolutional neural networks. Having fit the data
for scenes, we used the model to predict future data for large-scale scene
recognition as well as for objects and faces. Our results suggest that the
relative order of importance of using central visual field information is face
recognition>object recognition>scene recognition, and vice-versa for peripheral
information.


title:
Second-order hydrodynamics for fermionic cold atoms: Detailed analysis
  of transport coefficients and relaxation times

abstract:
  We give a detailed derivation of the second-order (local) hydrodynamics for
Boltzmann equation with an external force by using the renormalization group
method. In this method, we solve the Boltzmann equation faithfully to extract
the hydrodynamics without recourse to any ansatz. Our method leads to
microscopic expressions of not only all the transport coefficients that are of
the same form as those in Chapman-Enskog method but also those of the viscous
relaxation times $\tau_i$ that admit physically natural interpretations. As an
example, we apply our microscopic expressions to calculate the transport
coefficients and the relaxation times of the cold fermionic atoms in a
quantitative way, where the transition probability in the collision term is
given explicitly in terms of the $s$-wave scattering length $a_s$. We thereby
discuss the quantum statistical effects, temperature dependence, and
scattering-length dependence of the first-order transport coefficients and the
viscous relaxation times: It is shown that as the temperature is lowered, the
transport coefficients and the relaxation times increase rapidly because Pauli
principle acts effectively. On the other hand, as $a_s$ is increased, these
quantities decrease and become vanishingly small at unitarity because of the
strong coupling. The numerical calculation shows that the relation
$\tau_\pi=\eta/P$, which is derived in the relaxation-time approximation and
used in most of literature without almost any foundation, turns out to be
satisfied quite well, while the similar relation for the relaxation time
$\tau_J$ of the heat conductivity is satisfied only approximately with a
considerable error.


title: A Five Dimensional Generalization of the Topological Weyl Semimetal

abstract:
  We generalize the concept of three-dimensional topological Weyl semimetal to
a class of five dimensional (5D) gapless solids, where Weyl points are
generalized to Weyl surfaces which are two-dimensional closed manifolds in the
momentum space. Each Weyl surface is characterized by a U(1) second Chern
number $C_2$ defined on a four-dimensional manifold enclosing the Weyl surface,
which is equal to its topological linking number with other Weyl surfaces in
5D. In analogy to the Weyl semimetals, the surface states of the 5D metal take
the form of topologically protected Weyl fermion arcs, which connect the
projections of the bulk Weyl surfaces. The further generalization of
topological metal in $2n+1$ dimensions carrying the $n$-th Chern number $C_n$
is also discussed.


title:
Primordial Nucleosynthesis in the Rh = ct cosmology: Pouring cold water
  on the Simmering Universe

abstract:
  Primordial nucleosynthesis is rightly hailed as one of the great successes of
the standard cosmological model. Here we consider the initial forging of
elements in the recently proposed Rh = ct universe, a cosmology that demands
linear evolution of the scale factor. Such a universe cools extremely slowly
compared to standard cosmologies, considerably depleting the available neutrons
during nucleosynthesis; this has significant implications for the resultant
primordial abundances of elements, predicting a minuscule quantity of helium
which is profoundly at odds with observations. The production of helium can be
enhanced in such a "simmering universe" by boosting the baryon to photon ratio,
although more than an order of magnitude increase is required to bring the
helium mass fraction into accordance with observations. However, in this
scenario, the prolonged period of nucleosynthesis results of the efficient
cooking of lighter into heavier elements, impacting the resultant abundances of
all elements so that, other than hydrogen and helium, there are virtually no
light elements present in the universe. Without the addition of substantial new
physics in the early universe, it is difficult to see how the Rh = ct universe
can be considered a viable cosmological model.


title: Discovery of a Makemakean Moon

abstract:
  We describe the discovery of a satellite in orbit about the dwarf planet
(136472) Makemake. This satellite, provisionally designated S/2015 (136472) 1,
was detected in imaging data collected with the Hubble Space Telescope's Wide
Field Camera 3 on UTC April 27, 2015 at 7.80$\pm$0.04 magnitudes fainter than
Makemake. It likely evaded detection in previous satellite searches due to a
nearly edge-on orbital configuration, placing it deep within the glare of
Makemake during a substantial fraction of its orbital period. This
configuration would place Makemake and its satellite near a mutual event
season. Insufficient orbital motion was detected to make a detailed
characterization of its orbital properties, prohibiting a measurement of the
system mass with the discovery data alone. Preliminary analysis indicates that
if the orbit is circular, its orbital period must be longer than 12.4 days, and
must have a semi-major axis $\gtrsim$21,000 km. We find that the properties of
Makemake's moon suggest that the majority of the dark material detected in the
system by thermal observations may not reside on the surface of Makemake, but
may instead be attributable to S/2015 (136472) 1 having a uniform dark surface.
This "dark moon hypothesis" can be directly tested with future JWST
observations. We discuss the implications of this discovery for the spin state,
figure, and thermal properties of Makemake and the apparent ubiquity of
trans-Neptunian dwarf planet satellites.


title:
Volumes for ${\rm SL}_N(\mathbb R)$, the Selberg integral and random
  lattices

abstract:
  There is a natural left and right invariant Haar measure associated with the
matrix groups GL${}_N(\mathbb R)$ and SL${}_N(\mathbb R)$ due to Siegel. For
the associated volume to be finite it is necessary to truncate the groups by
imposing a bound on the norm, or in the case of SL${}_N(\mathbb R)$, by
restricting to a fundamental domain. We compute the asymptotic volumes
associated with the Haar measure for GL${}_N(\mathbb R)$ and SL${}_N(\mathbb
R)$ matrices in the case of that the operator norm lies between $R_1$ and
$1/R_2$ in the former, and this norm, or alternatively the 2-norm, is bounded
by $R$ in the latter. By a result of Duke, Rundnick and Sarnak, such asymptotic
formulas in the case of SL${}_N(\mathbb R)$ imply an asymptotic counting
formula for matrices in SL${}_N(\mathbb Z)$. We discuss too the sampling of
SL${}_N(\mathbb R)$ matrices from the truncated sets. By then using lattice
reduction to a fundamental domain, we obtain histograms approximating the
probability density functions of the lengths and pairwise angles of shortest
length bases vectors in the case $N=2$ and 3, or equivalently of shortest
linearly independent vectors in the corresponding random lattice. In the case
$N=2$ these distributions are evaluated explicitly.


title: Dynamic Pricing with Demand Covariates

abstract:
  We consider a firm that sells products over $T$ periods without knowing the
demand function. The firm sequentially sets prices to earn revenue and to learn
the underlying demand function simultaneously. A natural heuristic for this
problem, commonly used in practice, is greedy iterative least squares (GILS).
At each time period, GILS estimates the demand as a linear function of the
price by applying least squares to the set of prior prices and realized
demands. Then a price that maximizes the revenue, given the estimated demand
function, is used for the next time period. The performance is measured by the
regret, which is the expected revenue loss from the optimal (oracle) pricing
policy when the demand function is known. Recently, den Boer and Zwart (2014)
and Keskin and Zeevi (2014) demonstrated that GILS is sub-optimal. They
introduced algorithms which integrate forced price dispersion with GILS and
achieve asymptotically optimal performance.
  In this paper, we consider this dynamic pricing problem in a data-rich
environment. In particular, we assume that the firm knows the expected demand
under a particular price from historical data, and in each period, before
setting the price, the firm has access to extra information (demand covariates)
which may be predictive of the demand. We prove that in this setting GILS
achieves asymptotically optimal regret of order $\log(T)$. We also show the
following surprising result: in the original dynamic pricing problem of den
Boer and Zwart (2014) and Keskin and Zeevi (2014), inclusion of any set of
covariates in GILS as potential demand covariates (even though they could carry
no information) would make GILS asymptotically optimal. We validate our results
via extensive numerical simulations on synthetic and real data sets.


title: Nonparametric Bayesian Negative Binomial Factor Analysis

abstract:
  A common approach to analyze a covariate-sample count matrix, an element of
which represents how many times a covariate appears in a sample, is to
factorize it under the Poisson likelihood. We show its limitation in capturing
the tendency for a covariate present in a sample to both repeat itself and
excite related ones. To address this limitation, we construct negative binomial
factor analysis (NBFA) to factorize the matrix under the negative binomial
likelihood, and relate it to a Dirichlet-multinomial distribution based
mixed-membership model. To support countably infinite factors, we propose the
hierarchical gamma-negative binomial process. By exploiting newly proved
connections between discrete distributions, we construct two blocked and a
collapsed Gibbs sampler that all adaptively truncate their number of factors,
and demonstrate that the blocked Gibbs sampler developed under a compound
Poisson representation converges fast and has low computational complexity.
Example results show that NBFA has a distinct mechanism in adjusting its number
of inferred factors according to the sample lengths, and provides clear
advantages in parsimonious representation, predictive power, and computational
complexity over previously proposed discrete latent variable models, which
either completely ignore burstiness, or model only the burstiness of the
covariates but not that of the factors.


title: Polygons in restricted geometries subjected to infinite forces

abstract:
  We consider self-avoiding polygons in a restricted geometry, namely an
infinite $L\times M$ tube in $\mathbb Z^3$. These polygons are subjected to a
force $f$, parallel to the infinite axis of the tube. When $f>0$ the force
stretches the polygons, while when $f<0$ the force is compressive. We obtain
and prove the asymptotic form of the free energy in both limits
$f\to\pm\infty$. We conjecture that the $f\to-\infty$ asymptote is the same as
the limiting free energy of "Hamiltonian" polygons, polygons which visit every
vertex in a $L\times M\times N$ box. We investigate such polygons, and in
particular use a transfer-matrix methodology to establish that the conjecture
is true for some small tube sizes

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


title: Concordance and isotopy of metrics with positive scalar curvature, II

abstract:
  In this article, the author provides full details of the proof of the
concordance/isotopy problem. The first published proof,
  [5], accomplished this task only partially since there was an error, see the
erratum [6], which damaged the main argument of
  [5, Theorem 2.9], and, consequently, the proof of [5, Theorem A].


title: Estimating Weighted Matchings in $o(n)$ Space

abstract:
  We consider the problem of estimating the weight of a maximum weighted
matching of a weighted graph $G(V,E)$ whose edges are revealed in a streaming
fashion. We develop a reduction from the maximum weighted matching problem to
the maximum cardinality matching problem that only doubles the approximation
factor of a streaming algorithm developed for the maximum cardinality matching
problem. Our results hold for the insertion-only and the dynamic (i.e,
insertion and deletion) edge-arrival streaming models. The previous best-known
reduction is due to Bury and Schwiegelshohn (ESA 2015) who develop an algorithm
whose approximation guarantee scales by a polynomial factor.
  As an application, we obtain improved estimators for weighted planar graphs
and, more generally, for weighted bounded-arboricity graphs, by feeding into
our reduction the recent estimators due to Esfandiari et al. (SODA 2015) and to
Chitnis et al. (SODA 2016). In particular, we obtain a
$(48+\epsilon)$-approximation estimator for the weight of a maximum weighted
matching in planar graphs.


title:
Long-Term Identity-Aware Multi-Person Tracking for Surveillance Video
  Summarization

abstract:
  Multi-person tracking plays a critical role in the analysis of surveillance
video. However, most existing work focus on shorter-term (e.g. minute-long or
hour-long) video sequences. Therefore, we propose a multi-person tracking
algorithm for very long-term (e.g. month-long) multi-camera surveillance
scenarios. Long-term tracking is challenging because 1) the apparel/appearance
of the same person will vary greatly over multiple days and 2) a person will
leave and re-enter the scene numerous times. To tackle these challenges, we
leverage face recognition information, which is robust to apparel change, to
automatically reinitialize our tracker over multiple days of recordings.
Unfortunately, recognized faces are unavailable oftentimes. Therefore, our
tracker propagates identity information to frames without recognized faces by
uncovering the appearance and spatial manifold formed by person detections. We
tested our algorithm on a 23-day 15-camera data set (4,935 hours total), and we
were able to localize a person 53.2% of the time with 69.8% precision. We
further performed video summarization experiments based on our tracking output.
Results on 116.25 hours of video showed that we were able to generate a
reasonable visual diary (i.e. a summary of what a person did) for different
people, thus potentially opening the door to automatic summarization of the
vast amount of surveillance video generated every day.


title:
Triangular flow of negative pions emitted in PbAu collisions at
  $\sqrt{s_{NN}} = $ 17.3 GeV

abstract:
  Differential triangular flow, $v_3(p_T)$, of negative pions is measured at
$\sqrt{s_{NN}}$= 17.3 GeV around midrapidity by the CERES/NA45 experiment at
CERN in central PbAu collisions in the range 0-30\% with a mean centrality of
5.5\%. This is the first measurement as a function of transverse momentum of
the triangular flow at SPS energies. The $p_T$ range extends from about 0.05
GeV/c to more than 2 GeV/c. The triangular flow magnitude, corrected for the
HBT effects, is smaller by a factor of about 2 than the one measured by the
PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the
analyzed range of central collisions no significant centrality dependence is
observed. The data are found to be well described by a viscous hydrodynamic
calculation combined with an UrQMD cascade model for the late stages.


title:
Higher order anisotropies in the Buda-Lund model: Disentangling flow and
  density field anisotropies

abstract:
  The Buda-Lund hydro model describes an expanding ellipsoidal fireball, and
fits the observed elliptic flow and oscillating HBT radii successfully. Due to
fluctuations in energy depositions, the fireball shape however fluctuates on an
event-by-event basis. The transverse plane asymmetry can be translated into a
series of multipole anisotropy coefficients. These anisotropies then result in
measurable momentum-space anisotropies, to be measured with respect to their
respective symmetry planes. In this paper we detail an extension of the
Buda-Lund model to multipole anisotropies and investigate the resulting flow
coefficients and oscillations of HBT radii.


title:
First results on Bilepton production based on LHC collision data and
  predictions for Run II

abstract:
  The LHC potential for discovering doubly-charged vector bileptons is
investigated considering the measurable process $p p$ $\rightarrow$
$\mu^{\mp}\mu^{\mp}\mu^{\pm}\mu^{\pm} X$. The study is performed assuming
different bilepton and leptoquark masses. The process cross-section is
calculated at leading-order using the \textsc{Calchep} package. Combining the
calculation with the latest ATLAS experiment results at a center-of-mass energy
of 7 TeV, bounds on bilepton masses based on LHC data are derived for the first
time. The results exclude bileptons masses in the range of 200 GeV to 500 GeV
at 95\% C.L., depending on the leptoquark mass. Moreover, minimal LHC
integrated luminosities needed for discovering and for setting limits on
bilepton masses are obtained for 13 TeV center-of-mass energy. Simulated events
are passed through a fast parametric detector simulation using the Delphes
package.


title: On conjugacy of Cartan subalgebras in non-fgc Lie tori

abstract:
  We establish the conjugacy of Cartan subalgebras for generic Lie tori "of
type A". This is the only conjugacy problem of Lie tori related to Extended
Affine Lie Algebras that remained open.


title:
Resistive sensor and electromagnetic actuator for feedback stabilization
  of liquid metal walls in fusion reactors

abstract:
  Liquid metal walls in fusion reactors will be subject to instabilities,
turbulence, induced currents, error fields and temperature gradients that will
make them locally bulge, thus entering in contact with the plasma, or deplete,
hence exposing the underlying solid substrate. To prevent this, research has
begun to actively stabilize static or flowing liquid metal layers by locally
applying forces in feedback with thickness measurements. Here we present
resistive sensors of liquid metal thickness and demonstrate jxB actuators, to
locally control it.


title: Advancing Dynamic Fault Tree Analysis

abstract:
  This paper presents a new state space generation approach for dynamic fault
trees (DFTs) together with a technique to synthesise failures rates in DFTs.
Our state space generation technique aggressively exploits the DFT structure
--- detecting symmetries, spurious non-determinism, and don't cares. Benchmarks
show a gain of more than two orders of magnitude in terms of state space
generation and analysis time. Our approach supports DFTs with symbolic failure
rates and is complemented by parameter synthesis. This enables determining the
maximal tolerable failure rate of a system component while ensuring that the
mean time of failure stays below a threshold.


title:
Generically globally rigid graphs have generic universally rigid
  frameworks

abstract:
  We show that any graph that is generically globally rigid in $\mathbb{R}^d$
has a realization in $\mathbb{R}^d$ that is both generic and universally rigid.
This also implies that the graph also must have a realization in $\mathbb{R}^d$
that is both infinitesimally rigid and universally rigid; such a realization
serves as a certificate of generic global rigidity.
  Our approach involves an algorithm by Lov\'asz, Saks and Schrijver that, for
a sufficiently connected graph, constructs a general position orthogonal
representation of the vertices, and a result of Alfakih that shows how this
representation leads to a stress matrix and a universally rigid framework of
the graph.


title: Optimal Compression of a Polyline with Segments and Arcs

abstract:
  This paper describes an efficient approach to constructing a resultant
polyline with a minimum number of segments and arcs. While fitting an arc can
be done with complexity O(1) (see [1] and [2]), the main complexity is in
checking that the resultant arc is within the specified tolerance. There are
additional tests to check for the ends and for changes in direction (see [3,
section 3] and [4, sections II.C and II.D]). However, the most important part
in reducing complexity is the ability to subdivide the polyline in order to
limit the number of arc fittings [2]. The approach described in this paper
finds a compressed polyline with a minimum number of segments and arcs.


title: Prime and Primitive Algebras with Prescribed Growth Types

abstract:
  Bartholdi and Smoktunowicz constructed finitely generated monomial algebras
with prescribed sufficiently fast growth types. We show that their construction
need not result in a prime algebra, but it can be modified to provide prime
algebras without further limitations on the growth type.
  Moreover, using a construction of an inverse system of monomial ideals which
arise from this construction we are able to further construct finitely
generated primitive algebras with many regular enough growth types.
  Then, inspired by an example by Zelmanov, we show how our prime algebras can
be constructed such that they contain non-zero locally nilpotent ideals; this
is the very opposite of the primitive constructions.


title: Collection and Dissemination of Data on Time-Varying Digraphs

abstract:
  Given a network of fixed size $n$ and an initial distribution of data, we
derive sufficient connectivity conditions on a sequence of time-varying
digraphs for (a) data collection and (b) data dissemination, within at most
$(n-1)$ iterations. The former is shown to enable distributed computation of
the network size $n$, while the latter does not. Knowledge of $n$ subsequently
enables each node to acknowledge the earliest time point at which they can
cease communication, specifically we find the number of redundant signals can
be truncated at the finite time $n$. Using a probabilistic approach, we obtain
tight upper and lower bounds for the expected time until the $\textit{last}$
node obtains the entire collection of data, in other words complete data
dissemination. Similarly tight upper and lower bounds are also found for the
expected time until the $\textit{first}$ node obtains the entire collection of
data. Interestingly, these bounds are both $\Theta (\text{log}_2(n))$ and in
fact differ by only two iterations. Numerical results are explored and verify
each result.


title: Explicit Least-degree Boundary Filters for Discontinuous Galerkin

abstract:
  Convolving the output of Discontinuous Galerkin (DG) computations using
spline filters can improve both smoothness and accuracy of the output. At
domain boundaries, these filters have to be one-sided. Recently,
position-dependent smoothness-increasing accuracy-preserving (PSIAC) filters
were shown to be a superset of the top-of-the-line one-sided RLKV and SRV
filters. Since PSIAC filters can be formulated symbolically, convolution with
PSIAC filters reduces to a stable inner product with the DG output and hence
provides a stable and efficient implementation.
  The paper focuses on the remarkable fact that, for the canonical linear or
non-linear hyperbolic test equation, new piecewise constant PSIAC filters of
small support outperform the top-of-the-line boundary filters in the
literature. These least-degree filters reduce the error at the boundaries to
less than the error even of the symmetric filters of the same support that are
applied in the interior . Due to their simplicity, and since this least degree
filter has an exact symbolic form, convolution is stable as well as efficient
and derivatives of the convolved output are easy to compute.


title:
Joint Semantic Segmentation and Depth Estimation with Deep Convolutional
  Networks

abstract:
  Multi-scale deep CNNs have been used successfully for problems mapping each
pixel to a label, such as depth estimation and semantic segmentation. It has
also been shown that such architectures are reusable and can be used for
multiple tasks. These networks are typically trained independently for each
task by varying the output layer(s) and training objective. In this work we
present a new model for simultaneous depth estimation and semantic segmentation
from a single RGB image. Our approach demonstrates the feasibility of training
parts of the model for each task and then fine tuning the full, combined model
on both tasks simultaneously using a single loss function. Furthermore we
couple the deep CNN with fully connected CRF, which captures the contextual
relationships and interactions between the semantic and depth cues improving
the accuracy of the final results. The proposed model is trained and evaluated
on NYUDepth V2 dataset outperforming the state of the art methods on semantic
segmentation and achieving comparable results on the task of depth estimation.


title:
Non-Smooth Bifurcations of Uniformly Hyperbolic Invariant Manifolds in
  Skew Product Systems: Rigorous Results

abstract:
  In this paper we study the anti-integrable limit scenario of skew-product
systems. We consider a generalization of such systems based on the
Frenkel-Kontorova model, and prove the existence of orbits with any fibered
rotation number in systems of both one and two degrees of freedom. In
particular, our results also apply to two dimensional maps with degenerate
potentials (vanishing second derivative), so extending the results of existence
of Cantori for more general twist maps.
  We also prove that under certain mild regularity conditions on the potential
the structure of the orbits is of Cantor type. From our results we deduce the
existence of the non-smooth folding bifurcation (conjectured by Figueras-Haro,
\textit{Different scenarios for hyperbolicity breakdown in quasiperiodic area
preserving twist maps}, Chaos:25 (2015)).
  Lastly we present a pair of results which are useful in determining if a
potential satisfies the regularity conditions required for the Cantor sets of
orbits to exist and are also of independent interest.


title: Three-dimensional gravity-driven deterministic lateral displacement

abstract:
  We present a simple solution to enhance the separation ability of
deterministic lateral displacement (DLD) systems by expanding the
two-dimensional nature of these devices and driving the particles into
size-dependent, fully three-dimensional trajectories. Specifically, we drive
the particles through an array of long cylindrical posts, such that they not
only move in the plane perpendicular to the posts as in traditional
two-dimensional DLD systems (in-plane motion), but also along the axial
direction of the solid posts (out-of-plane motion). We show that the
(projected) in-plane motion of the particles is completely analogous to that
observed in 2D-DLD systems. In fact, a theoretical model originally developed
for force-driven, two-dimensional DLD systems accurately describes the
experimental results. More importantly, we analyze the particles out-of-plane
motion and observe that, for certain orientations of the driving force,
significant differences in the out-of-plane displacement depending on particle
size. Therefore, taking advantage of both the in-plane and out-of-plane motion
of the particles, it is possible to achieve the simultaneous fractionation of a
polydisperse suspension into multiple streams.


title:
Positive metric entropy arises in some nondegenerate nearly integrable
  systems

abstract:
  The celebrated KAM Theory says that if one makes a small perturbation of a
non-degenerate completely integrable system, we still see a huge measure of
invariant tori with quasi-periodic dynamics in the perturbed system. These
invariant tori are known as KAM tori. What happens outside KAM tori draws a lot
of attention. In this paper we present a Lagrangian perturbation of the
geodesic flow on a flat 3-torus. The perturbation is $C^\infty$ small but the
flow has a positive measure of trajectories with positive Lyapunov exponent,
namely, the flow has positive metric entropy. From this result we get positive
metric entropy outside some KAM tori.


title: Deep Multi-fidelity Gaussian Processes

abstract:
  We develop a novel multi-fidelity framework that goes far beyond the
classical AR(1) Co-kriging scheme of Kennedy and O'Hagan (2000). Our method can
handle general discontinuous cross-correlations among systems with different
levels of fidelity. A combination of multi-fidelity Gaussian Processes (AR(1)
Co-kriging) and deep neural networks enables us to construct a method that is
immune to discontinuities. We demonstrate the effectiveness of the new
technology using standard benchmark problems designed to resemble the outputs
of complicated high- and low-fidelity codes.


title: Charged C-metric in conformal gravity

abstract:
  Using a C-metric-type ansatz, we obtain an exact solution to conformal
gravity coupled to a Maxwell electromagnetic field. The solution resembles a
C-metric spacetime carrying an electromagnetic charge. The metric is cast in a
factorised form which allows us to study the domain structure of its static
coordinate regions. This metric reduces to the well-known Mannheim-Kazanas
metric under an appropriate limiting procedure, and also reduces to the
(Anti-)de Sitter C-metric of Einstein gravity for a particular choice of
parameters.


title: Fast polynomial transforms based on Toeplitz and Hankel matrices

abstract:
  Many standard conversion matrices between coefficients in classical
orthogonal polynomial expansions can be decomposed using diagonally-scaled
Hadamard products involving Toeplitz and Hankel matrices. This allows us to
derive $\smash{\mathcal{O}(N(\log N)^2)}$ algorithms, based on the fast Fourier
transform, for converting coefficients of a degree $N$ polynomial in one
polynomial basis to coefficients in another. Numerical results show that this
approach is competitive with state-of-the-art techniques, requires no
precomputational cost, can be implemented in a handful of lines of code, and is
easily adapted to extended precision arithmetic.


title: Global-Local Mixtures

abstract:
  Global-local mixtures are derived from the Cauchy-Schlomilch and Liouville
integral transformation identities. We characterize well-known normal-scale
mixture distributions including the Laplace or lasso, logit and quantile as
well as new global-local mixtures. We also apply our methodology to
convolutions that commonly arise in Bayesian inference. Finally, we conclude
with a conjecture concerning bridge and uniform correlation mixtures.


title: Polyphase equiangular tight frames and abelian generalized quadrangles

abstract:
  An equiangular tight frame (ETF) is a type of optimal packing of lines in a
finite-dimensional Hilbert space. ETFs arise in various applications, such as
waveform design for wireless communication, compressed sensing, quantum
information theory and algebraic coding theory. In a recent paper, signature
matrices of ETFs were constructed from abelian distance regular covers of
complete graphs. We extend this work, constructing ETF synthesis operators from
abelian generalized quadrangles, and vice versa. This produces a new infinite
family of complex ETFs as well as a new proof of the existence of certain
generalized quadrangles. This work involves designing matrices whose entries
are polynomials over a finite abelian group. As such, it is related to the
concept of a polyphase matrix of a finite filter bank.


title:
Ab initio Investigation of Adsorption Characteristics of Bisphosphonates
  on Hydroxyapatite (001) Surface

abstract:
  The structures of some bisphosphonates (clodronate, etidronate, pamidronate,
alendronate, risedronate, zoledronate, minodronate) were obtained and analyzed,
and their adsorption energies onto hydroxyapatite (001) surface were compared
to find out ranking order of binding affinity, which shows that the adsorption
energy is the largest for pamidronate, followed by alendronate, zoledronate,
clodronate, ibandronate, the lowest for minodronate and etidronate.


title: Twisted Alexander invariants and Hyperbolic volume

abstract:
  We give a volume formula of hyperbolic knot complements using twisted
Alexander invariants.


title:
Implementation of Interior-point Methods for LP based on Krylov Subspace
  Iterative Solvers with Inner-iteration Preconditioning

abstract:
  We apply novel inner-iteration preconditioned Krylov subspace methods to the
interior-point algorithm for linear programming (LP). Inner-iteration
preconditioners recently proposed by Morikuni and Hayami enable us to overcome
the severe ill-conditioning of linear equations solved in the final phase of
interior-point iterations. The Krylov subspace methods do not suffer from
rank-deficiency and therefore no preprocessing is necessary even if rows of the
constraint matrix are not linearly independent. By means of these methods, a
new interior-point recurrence is proposed in order to omit one matrix-vector
product at each step. Extensive numerical experiments are conducted over
diverse instances of 138 LP problems including the Netlib, QAPLIB, Mittelmann
and Atomizer Basis Pursuit collections. The largest problem has 434,580
unknowns. It turns out that our implementation is more robust than the standard
public domain solvers SeDuMi (Self-Dual Minimization), SDPT3 (Semidefinite
Programming Toh-Todd-T\"ut\"unc\"u) and the LSMR iterative solver in PDCO
(Primal-Dual Barrier Method for Convex Objectives) without increasing CPU time.
The proposed interior-point method based on iterative solvers succeeds in
solving a fairly large number of LP instances from benchmark libraries under
the standard stopping criteria. The work also presents a fairly extensive
benchmark test for several renowned solvers including direct and iterative
solvers.


title: Fast Fabrication of Sub-200-nm Nanogrooves using Liquid Crystal Material

abstract:
  Self-assembly of soft materials attracts keen interest for patterning
applications owing to its ease and spontaneous behavior. We report the
fabrication of nanogrooves using sublimation and recondensation of liquid
crystal (LC) materials. First, well-aligned smectic LC structures are obtained
on the micron-scale topographic patterns of the microchannel; then the
sublimation and recondensation process directly produces nanogrooves having
sub-200-nm scale. The entire process can be completed in less than 30 min.
After it is replicated using an ultraviolet-curable polymer, our platform can
be used as an alignment layer to control other guest LC materials.


title:
The 2.4 $\mu$m Galaxy Luminosity Function as Measured Using WISE. I.
  Measurement Techniques

abstract:
  The astronomy community has at its disposal a large back catalog of public
spectroscopic galaxy redshift surveys that can be used for the measurement of
luminosity functions. Utilizing the back catalog with new photometric surveys
to maximum efficiency requires modeling the color selection bias imposed on
selection of target galaxies by flux limits at multiple wavelengths. The
likelihood derived herein can address, in principle, all possible color
selection biases through the use of a generalization of the luminosity
function, $\Phi(L)$, over the space of all spectra: the spectro-luminosity
functional, $\Psi[L_\nu]$. It is, therefore, the first estimator capable of
simultaneously analyzing multiple redshift surveys in a consistent way. We also
propose a new way of parametrizing the evolution of the classic Shechter
function parameters, $L_\star$ and $\phi_\star$, that improves both the
physical realism and statistical performance of the model. The techniques
derived in this work will be used in an upcoming paper to measure the
luminosity function of galaxies at the rest frame wavelength of
$2.4\operatorname{\mu m}$ using the Widefield Infrared Survey Explorer (WISE).

categories: astro-ph.CO astro-ph.GA astro-ph.IM physics.data-an


title:
Gauge angle dependence in TDHFB calculations of ${}^{20}$O + ${}^{20}$O
  head-on collisions with the Gogny interaction

abstract:
  A numerical method to solve the TDHFB equations by using a hybrid basis of
the two-dimensional harmonic oscillator eigenfunctions and one-dimensional
Lagrange mesh with the Gogny effective interaction is applied to the head-on
collisions of the superfluid nuclei ${}^{20}$O's. Taking the energies around
the barrier top energy, the trajectories, pairing energies, and numbers of
transferred nucleons are displayed. Their dependence on the relative gauge
angle at the initial time is studied by taking typical sample points of the
gauge angle. It turned out that the functional form of the flux of the neutrons
across a section plane is proportional to the sine of the two times of the
gauge angle.


title: Congruences for powers of the partition function

abstract:
  Let $p_{-t}(n)$ denote the number of partitions of $n$ into $t$ colors. In
analogy with Ramanujan's work on the partition function, Lin recently proved in
\cite{Lin} that $p_{-3}(11n+7)\equiv0\pmod{11}$ for every integer $n$. Such
congruences, those of the form $p_{-t}(\ell n + a) \equiv 0 \pmod {\ell}$, were
previously studied by Kiming and Olsson. If $\ell \geq 5$ is prime and $-t \not
\in \{\ell - 1, \ell -3\}$, then such congruences satisfy $24a \equiv -t \pmod
{\ell}$. Inspired by Lin's example, we obtain natural infinite families of such
congruences. If $\ell\equiv2\pmod{3}$ (resp. $\ell\equiv3\pmod{4}$ and
$\ell\equiv11\pmod{12}$) is prime and $r\in\{4,8,14\}$ (resp. $r\in\{6,10\}$
and $r=26$), then for $t=\ell s-r$, where $s\geq0$, we have that
\begin{equation*} p_{-t}\left(\ell
n+\frac{r(\ell^2-1)}{24}-\ell\Big\lfloor\frac{r(\ell^2-1)}{24\ell}\Big\rfloor\right)\equiv0\pmod{\ell}.
\end{equation*} Moreover, we exhibit infinite families where such congruences
cannot hold.


title:
A Rich Globular Cluster System in Dragonfly 17: Are Ultra-Diffuse
  Galaxies Pure Stellar Halos?

abstract:
  Observations of nearby galaxy clusters at low surface brightness have
identified galaxies with low luminosities, but sizes as large as L* galaxies,
leading them to be dubbed "ultra-diffuse galaxies" (UDGs). The survival of UDGs
in dense environments like the Coma cluster suggests that UDGs could reside in
much more massive dark halos. We report the detection of a substantial
population of globular clusters (GCs) around a Coma UDG, Dragonfly 17 (DF17).
We find that DF17 has a high GC specific frequency of S_N=26+/-13. The GC
system is extended, with an effective radius of 12"+/-2", or 5.6+/-0.9 kpc at
Coma distance, 70% larger than the galaxy itself. We also estimate the mean of
the GC luminosity function to infer a distance of 97 (+17/-14) Mpc, providing
redshift-independent confirmation that one of these UDGs is in the Coma
cluster. The presence of a rich GC system in DF17 indicates that, despite its
low stellar density, star formation was intense enough to form many massive
star clusters. If DF17's ratio of total GC mass to total halo mass is similar
to those in other galaxies, then DF17 has an inferred total mass of ~10^11
solar masses, only ~10% the mass of the Milky Way, but extremely dominated by
dark matter, with M/L_V~1000. We suggest that UDGs like DF17 may be "pure
stellar halos", i.e., galaxies that formed their stellar halo components, but
then suffered an early cessation in star formation that prevented the formation
of any substantial central disk or bulge.


title:
Revisiting chaos in stimulus-driven spiking networks: signal encoding
  and discrimination

abstract:
  Highly connected recurrent neural networks often produce chaotic dynamics,
meaning their precise activity is sensitive to small perturbations. What are
the consequences for how such networks encode streams of temporal stimuli? On
the one hand, chaos is a strong source of randomness, suggesting that small
changes in stimuli will be obscured by intrinsically generated variability. On
the other hand, recent work shows that the type of chaos that occurs in spiking
networks can have a surprisingly low-dimensional structure, suggesting that
there may be "room" for fine stimulus features to be precisely resolved. Here
we show that strongly chaotic networks produce patterned spikes that reliably
encode time-dependent stimuli: using a decoder sensitive to spike times on
timescales of 10's of ms, one can easily distinguish responses to very similar
inputs. Moreover, recurrence serves to distribute signals throughout chaotic
networks so that small groups of cells can encode substantial information about
signals arriving elsewhere. A conclusion is that the presence of strong chaos
in recurrent networks does not prohibit precise stimulus encoding.


title: Embeddings of spaces of quregisters into special linear groups

abstract:
  We study embeddings of the unit sphere of complex Hilbert spaces of dimension
a power $2^n$ into the corresponding groups of non-singular linear
transformations. For the case of $n=1$, the sphere $S_2$ of qubits is
identified with $\mbox{SU}(2)$ and the algebraic structure of this last group
is carried into $S_2$. Hence it is natural to analyse whether is it possible,
for $n\geq 2$, to carry the structure of the symmetry group $\mbox{SU}(2^n)$
into the unit sphere $S_{2^n}$. For $n=2$ the embeddings of $S_{2^2}$ into
$\mbox{GL}(2^2)$, obtained as tensor products of the above embedding, fails to
determine a bijection between $S_{2^2}$ and $\mbox{SU}(2^2)$, but they
determine entanglement measures consistent with von Neumann entropy.


title:
Modern Physiognomy: An Investigation on Predicting Personality Traits
  and Intelligence from the Human Face

abstract:
  The human behavior of evaluating other individuals with respect to their
personality traits and intelligence by evaluating their faces plays a crucial
role in human relations. These trait judgments might influence important social
outcomes in our lives such as elections and court sentences. Previous studies
have reported that human can make valid inferences for at least four
personality traits. In addition, some studies have demonstrated that facial
trait evaluation can be learned using machine learning methods accurately. In
this work, we experimentally explore whether self-reported personality traits
and intelligence can be predicted reliably from a facial image. More
specifically, the prediction problem is separately cast in two parts: a
classification task and a regression task. A facial structural feature is
constructed from the relations among facial salient points, and an appearance
feature is built by five texture descriptors. In addition, a minutia-based
fingerprint feature from a fingerprint image is also explored. The
classification results show that the personality traits "Rule-consciousness"
and "Vigilance" can be predicted reliably, and that the traits of females can
be predicted more accurately than those of male. However, the regression
experiments show that it is difficult to predict scores for individual
personality traits and intelligence. The residual plots and the correlation
results indicate no evident linear correlation between the measured scores and
the predicted scores. Both the classification and the regression results reveal
that "Rule-consciousness" and "Tension" can be reliably predicted from the
facial features, while "Social boldness" gets the worst prediction results. The
experiments results show that it is difficult to predict intelligence from
either the facial features or the fingerprint feature, a finding that is in
agreement with previous studies.


title:
A Chevalley formula for the equivariant quantum K-theory of cominuscule
  varieties

abstract:
  We prove a type-uniform Chevalley formula for multiplication with divisor
classes in the equivariant quantum $K$-theory ring of any cominuscule flag
variety $G/P$. We also prove that multiplication with divisor classes
determines the equivariant quantum $K$-theory of arbitrary flag varieties.
These results prove a conjecture of Gorbounov and Korff concerning the
equivariant quantum $K$-theory of Grassmannians of Lie type A.


title: Mapping the Monoceros Ring in 3D with Pan-STARRS1

abstract:
  Using the Pan-STARRS1 survey, we derive limiting magnitude, spatial
completeness and density maps that we use to probe the three dimensional
structure and estimate the stellar mass of the so-called Monoceros Ring. The
Monoceros Ring is an enormous and complex stellar sub-structure in the outer
Milky Way disk. It is most visible across the large Galactic Anticenter region,
120 < l < 240 degrees, -30 < b < +40 degrees. We estimate its stellar mass
density profile along every line of sight in 2 X 2 degree pixels over the
entire 30,000 square degree Pan-STARRS1 survey using the previously developed
MATCH software. By parsing this distribution into a radially smooth component
and the Monoceros Ring, we obtain its mass and distance from the Sun along each
relevant line of sight. The Monoceros Ring is significantly closer to us in the
South (6 kpc) than in the North (9 kpc). We also create 2D cross sections
parallel to the Galactic plane that show 135 degrees of the Monoceros Ring in
the South and 170 degrees of the Monoceros Ring in the North. We show that the
Northern and Southern structures are also roughly concentric circles,
suggesting that they may be a wave rippling from a common origin. Excluding the
Galactic plane, we observe an excess stellar mass of 4 million solar masses
across 120 < l < 240 degrees. If we interpolate across the Galactic plane, we
estimate that this region contains 8 million solar masses. If we assume
(somewhat boldly) that the Monoceros Ring is a set of two Galactocentric rings,
its total stellar mass is 60 million solar masses. Finally, if we assume that
it is a set of two circles centered at a point 4 kpc from the Galactic center
in the anti-central direction, as our data suggests, we estimate its stellar
mass to be 40 million solar masses.


title:
Quantifying the Topology and Evolution of a Magnetic Flux Rope
  Associated with Multi-flare Activities

abstract:
  Magnetic flux rope (MFR) plays an important role in solar activities. A
quantitative assessment of the topology of an MFR and its evolution is crucial
for a better understanding of the relationship between the MFR and the
associated activities. In this paper, we investigate the magnetic field of
active region 12017 from 2014 March 28 to 29, where 12 flares were triggered by
the intermittent eruptions of a filament (either successful or confined). Using
the vector magnetic field data from the Helioseismic and Magnetic Imager on
board the \textit{Solar Dynamics Observatory}, we calculate the magnetic energy
and helicity injection in the active region, and extrapolate the 3D magnetic
field with a nonlinear force-free field model. From the extrapolations, we find
an MFR that is cospatial with the filament. We further determine the
configuration of this MFR by a closed quasi-separatrix layer (QSL) around it.
Then, we calculate the twist number and the magnetic helicity for the field
lines composing the MFR. The results show that the closed QSL structure
surrounding the MFR gets smaller as a consequence of the flare occurrence. We
also find that the flares in our sample are mainly triggered by kink
instability. Moreover, the twist number varies more sensitively than other
parameters to the occurrence of flares.


title:
Irregular varieites with geometric genus one, theta divisors, and fake
  tori

abstract:
  We study the Albanese image of a compact K\"ahler manifold whose geometric
genus is one. We prove that if the Albanese map is not surjective, then the
manifold maps surjectively onto an ample divisor in some abelian variety, and
in many cases the ample divisor is a theta divisor. With a further natural
assumption on the topology of the manifold, we prove that the manifold is an
algebraic fiber space over a genus two curve. Finally we apply these results to
study the geometry of a compact K\"ahler manifold which has the same Hodge
numbers as those of an abelian variety of the same dimension.


title: The pulse shape of cosmic-ray ground-level enhancements

abstract:
  Enhancements of the comic-ray intensity as observed by detectors on the
ground have been observed 71 times since 1942. They are due to solar energetic
particles accelerated in the regions of solar flares deep in the corona, or in
the shock front of coronal mass ejections (CMEs) in the solar wind. The latter
is the favoured model for the classical gradual ground-level enhancement (GLE).
In several papers since the one of McCracken et al. (2008), we pointed out,
however, that some GLEs are too impulsive to be accelerated in the CME shocks.
With this hypothesis in mind we study the time profiles of all the available
GLEs. The main results are that there is a continuous range from gradual to
impulsive, that the fastest risers are concentrated at heliolongitudes that are
magnetically well-connected to Earth, and that the shape of the pulse is a
powerful indicator of propagation conditions between Sun and Earth. This ranges
from relatively quiet to highly disturbed.


title: The significance of anisotropic signals hiding in the type Ia supernovae

abstract:
  We use two different methods, i.e., dipole-fitting (DF) and hemisphere
comparison (HC), to search for the anisotropic signals hiding in the Union2.1
data set. We find that the directions of maximum matter density derived using
these two methods are about $114^{\circ}$ away from each other. We construct
four Union2.1-like mock samples to test the statistical significance of these
two methods. It is shown that DF method is statistically significant, while HC
method is strongly biased by the distribution of data points in the sky. Then
we assume that the anisotropy of distance modulus is mainly induced by the
anisotropy of matter density, which is modeled to be the dipole form
$\Omega_M=\Omega_{M0}(1-\cos\theta)$. We fit our model to Union2.1, and find
that the direction of maximum matter density is well consistent with the
direction derived using DF method, but it is very different from the direction
previously claimed. Monte Carlo simulations show that our method is
statistically more significant than HC method, although it is not as
significant as DF method. The statistical significance can be further improved
if the data points are homogeneously distributed in the sky. Due to the low
quality of present supernovae data, however, it is still premature to claim
that the Universe has any preferred direction.


title: Physical Layer Security in Millimeter Wave Cellular Networks

abstract:
  Recent researches show that millimeter wave (mmWave) communications can offer
orders of magnitude increases in the cellular capacity. However, the secrecy
performance of a mmWave cellular network has not been investigated so far.
Leveraging the new path-loss and blockage models for mmWave channels, which are
significantly different from the conventional microwave channel, this paper
comprehensively studies the network-wide physical layer security performance of
the downlink transmission in a mmWave cellular network under a stochastic
geometry framework. We first study the secure connectivity probability and the
average number of perfect communication links per unit area in a noise-limited
mmWave network for both non-colluding and colluding eavesdroppers scenarios,
respectively. Then, we evaluate the effect of the artificial noise (AN) on the
secrecy performance, and derive the analysis result of average number of
perfect communication links per unit area in an interference-limited mmWave
network. Numerical results are demonstrated to show the network-wide secrecy
performance, and provide interesting insights into how the secrecy performance
is influenced by various network parameters: antenna array pattern, base
station (BS) intensity, and AN power allocation, etc.


title:
Once for All: a Two-flow Convolutional Neural Network for Visual
  Tracking

abstract:
  One of the main challenges of visual object tracking comes from the arbitrary
appearance of objects. Most existing algorithms try to resolve this problem as
an object-specific task, i.e., the model is trained to regenerate or classify a
specific object. As a result, the model need to be initialized and retrained
for different objects. In this paper, we propose a more generic approach
utilizing a novel two-flow convolutional neural network (named YCNN). The YCNN
takes two inputs (one is object image patch, the other is search image patch),
then outputs a response map which predicts how likely the object appears in a
specific location. Unlike those object-specific approach, the YCNN is trained
to measure the similarity between two image patches. Thus it will not be
confined to any specific object. Furthermore the network can be end-to-end
trained to extract both shallow and deep convolutional features which are
dedicated for visual tracking. And once properly trained, the YCNN can be
applied to track all kinds of objects without further training and updating.
Benefiting from the once-for-all model, our algorithm is able to run at a very
high speed of 45 frames-per-second. The experiments on 51 sequences also show
that our algorithm achieves an outstanding performance.


title:
Development of Gold Tiny Particles and Particles in Different Sizes at
  Varying Precursor Concentration

abstract:
  Coalescence (or Growth) of tiny particles to larger particles has been an
exciting and practical research topic in nanotechnology. This study deals with
development of gold particles at varying precursor concentration in a
custom-built setup. Under the tuned ratio of bipolar pulse OFF to ON time, tiny
particles of different sizes and shapes develop depending on the amount of gold
precursor. When compact monolayer assembly is formed on solution surface, nano
energy in packet shapes bind gold atoms in own shape. Between 0.07 mM to 0.90
mM precursor concentration, tiny particles develop in both triangular and
non-triangular shapes. Tiny particles of triangular shape develop in a large
number at precursor concentration 0.30 mM and 0.60 mM. Hence, nanoparticles and
particles also developed in different geometrical shapes. Such tiny particles
pack due to the exerted force in immersing format, where made structures of
smooth elements assemble to develop nanoparticles and particles of different
shapes. Tiny particles of non-geometrical shapes do not assemble at a common
point and their assembling develops a nanoparticle or particle of distorted or
spherical shape. This occurs mainly when precursor concentration is 0.05 mM and
1.20 mM. At 50 sccm Argon flow rate, nanoparticles and particles develop in the
same shapes as in case of 100 sccm. For different precursor concentrations,
different colors of solutions indicate different features of nanoparticles and
particles. This study clarifies the necessary concentration of precursor to
develop colloids of different sizes.


title:
The Operator Product Expansion Beyond Leading Order for Two-Component
  Fermions

abstract:
  We consider a homogeneous, balanced gas of strongly interacting fermions in
two spin states interacting through a large scattering length. Finite range
corrections are needed for a quantitative description of data which experiments
and numerical simulations have provided. We use a perturbative field
theoretical framework and a tool called the Operator Product Expansion (OPE),
which together allow for the expression of finite range corrections to the
universal relations and momentum distribution. Using the OPE, we derive the
$1/k^6$ part of the momentum tail, which is related to the sum of the
derivative of the energy with respect to the finite range and the averaged
kinetic energy of opposite spin pairs. By comparing the $1/k^4$ term and the
$1/k^6$ correction in the momentum distribution to provided Quantum Monte Carlo
(QMC) data, we show that including the $1/k^6$ part offers marked improvements.
Our field theoretical approach allows for a clear understanding of the role of
the scattering length and finite effective range in the universal relations and
the momentum distribution.


title:
A Novel Similarity Measure for Intrusion Detection using Gaussian
  Function

abstract:
  In this paper the major objective is to design and analyze the suitability of
Gaussian similarity measure for intrusion detection. The objective is to use
this as a distance measure to find the distance between any two data samples of
training set such as DARPA Data Set, KDD Data Set. This major objective is to
use this measure as a distance metric when applying k- means algorithm. The
novelty of this approach is making use of the proposed distance function as
part of k-means algorithm so as to obtain disjoint clusters. This is followed
by a case study, which demonstrates the process of Intrusion Detection. The
proposed similarity has fixed upper and lower bounds. The proposed similarity
measure satisfies all properties of a typical similarity measure.


title:
Detection of HIV-1 antigen based on magnetic tunnel junction sensor and
  magnetic nanoparticles

abstract:
  In recent years, it is evidenced that the individuals newly infected HIV are
transmitting the virus prior to knowing their HIV status. Identifying
individuals that are early in infection with HIV antibody negative (window
period) remains problematic. In the newly infected individuals, HIV antigen p24
is usually present in their serum or plasma 7-10 days before the HIV antibody.
After antibody production initiates, the p24 antigen is bound into immune
complexes. That means the detectable p24 antigens in serum/plasma are
short-lived, and their amount is in the pg/ml range. Thus, a rapid quantitative
bio-detection system with high-sensitivity is required to achieve early disease
diagnosis. Magnetoresistive (MR) biosensor with ultra-high sensitivity
possesses great potential in this area. In this study, a p24 detection assay
using MgO-based magnetic tunnel junction (MTJ) sensor and 20-nm magnetic
nanoparticles is reported.


title: Interaction-Driven Spontaneous Quantum Hall Effect on Kagome Lattice

abstract:
  Non-interacting topological states of matter can be realized in band
insulators with intrinsic spin-orbital couplings as a result of the nontrivial
band topology. In recent years, the possibility of realizing novel
interaction-driven topological phase has attracted a lot of research
activities, which may significantly extend the classes of topological states of
matter. Here, we report a new finding of an interaction-driven spontaneous
quantum Hall effect (QHE) (Chern insulator) emerging in an extended
fermion-Hubbard model on kagome lattice. By means of the state-of-the-art
density-matrix renormalization group, we expose universal properties of the QHE
including time-reversal symmetry spontaneous breaking and quantized Hall
conductance. By accessing the ground state in large systems, we demonstrate the
robustness of the QHE against finite-size effects. Moreover, we map out a phase
diagram and identify two competing charge density wave phases by varying
interactions, where transitions to the QHE phase are determined to be of the
first order. Our study provides a "proof-of-the-principle" demonstration of
interaction-driven QHE without requirement of external magnetic field or
magnetic doping.


title: Semantic Change Detection with Hypermaps

abstract:
  Change detection is the study of detecting changes between two different
images of a scene taken at different times. By the detected change areas,
however, a human cannot understand how different the two images. Therefore, a
semantic understanding is required in the change detection research such as
disaster investigation. The paper proposes the concept of semantic change
detection, which involves intuitively inserting semantic meaning into detected
change areas. We mainly focus on the novel semantic segmentation in addition to
a conventional change detection approach. In order to solve this problem and
obtain a high-level of performance, we propose an improvement to the
hypercolumns representation, hereafter known as hypermaps, which effectively
uses convolutional maps obtained from convolutional neural networks (CNNs). We
also employ multi-scale feature representation captured by different image
patches. We applied our method to the TSUNAMI Panoramic Change Detection
dataset, and re-annotated the changed areas of the dataset via semantic
classes. The results show that our multi-scale hypermaps provided outstanding
performance on the re-annotated TSUNAMI dataset.


title:
In-situ Instrumental Setup for Influence Study of Hard-axis Bias
  Magnetic Field on MR transfer curves of sing MTJ sensor and MTJs array sensor

abstract:
  Establishment of home-made measurement setups for the characterization of MR
sensor is proposed and described here. The MR loops of MR sensors can be
obtained with the instrument using two-point probe measurement and four-point
probe measurement. Two pairs of Helmholtz coils can supply a hard-axis magnetic
field and a soft-axis magnetic field for the sensor. The single MTJ sensor and
MTJs array sensor in Wheatstone bridge were characterized and compared here.
The influence of hard-bias magnetic field on MR transfer curves of sing MTJ
sensor and MTJs array sensor are investigated. The corresponding optimal
hard-axis magnetic fields were obtained through Helmholtz coils to eliminate
the hysteresis for linear response of single MTJ sensor and MTJs array sensor.


title: Parallel Local Graph Clustering

abstract:
  Graph clustering has many important applications in computing, but due to
growing sizes of graphs, even traditionally fast clustering methods such as
spectral partitioning can be computationally expensive for real-world graphs of
interest. Motivated partly by this, so-called local algorithms for graph
clustering have received significant interest due to the fact that they can
find good clusters in a graph with work proportional to the size of the cluster
rather than that of the entire graph. This feature has proven to be crucial in
making such graph clustering and many of its downstream applications efficient
in practice. While local clustering algorithms are already faster than
traditional algorithms that touch the entire graph, they are sequential and
there is an opportunity to make them even more efficient via parallelization.
In this paper, we show how to parallelize many of these algorithms in the
shared-memory multicore setting, and we analyze the parallel complexity of
these algorithms. We present comprehensive experiments on large-scale graphs
showing that our parallel algorithms achieve good parallel speedups on a modern
multicore machine, thus significantly speeding up the analysis of local graph
clusters in the very large-scale setting.


title: Nearly Free Electron States in MXenes

abstract:
  Using a set of first-principles calculations, we studied the electronic
structures of two-dimensional transition metal carbides and nitrides, so called
MXenes, functionalized with F, O, and OH. Our projected band structures and
electron localization function analyses reveal the existence of nearly free
electron (NFE) states in variety of MXenes. The NFE states are spatially
located just outside the atomic structure of MXenes and are extended parallel
to the surfaces. Moreover, we found that the OH-terminated MXenes offer the NFE
states energetically close to the Fermi level. In particular, the NFE states in
some of the OH-terminated MXenes, such as Ti2C(OH)2, Zr2C(OH)2, Zr2N(OH)2,
Hf2C(OH)2, Hf2N(OH)2, Nb2C(OH)2, and Ta2C(OH)2, are partially occupied. This is
in remarkable contrast to graphene, graphane, and MoS2, in which their NFE
states are located far above the Fermi level and thus they are unoccupied. As a
prototype of such systems, we investigated the electron transport properties of
Hf2C(OH)2 and found that the NFE states in Hf2C(OH)2 provide almost perfect
transmission channels without nuclear scattering for electron transport. Our
results indicate that these systems might find applications in nanoelectronic
devices. Our findings provide new insights into the unique electronic band
structures of MXenes.


title:
Quantifiable simulation of quantum computation beyond stochastic
  ensemble computation

abstract:
  In this study, a distinctive feature of quantum computation (QC) is
characterized. To this end, a seemingly-powerful classical computing model,
called "stochastic ensemble machine (SEnM)," is considered. The SEnM runs with
an ensemble consisting of finite copies of a single probabilistic machine,
hence is as powerful as a probabilistic Turing machine (PTM). Then the
hypothesis--that is, the SEnM can effectively simulate a general circuit model
of QC--is tested by introducing an information-theoretic inequality, named
readout inequality. The inequality is satisfied by the SEnM and imposes a
critical condition: if the hypothesis holds, the inequality should be satisfied
by the probing model of QC. However, it is shown that the above hypothesis is
not generally accepted with the inequality violation, namely, such a simulation
necessarily fails, implying that PTM $\subseteq$ QC.


title:
Frustrated antiferromagnetic spin chains of edge-sharing tetrahedra in
  volcanic minerals K3Cu3(Fe0.82Al0.18)O2(SO4)4 and K4Cu4O2(SO4)4MeCl

abstract:
  The calculation of the sign and strength of magnetic interactions in two
noncentrosymmetric minerals (klyuchevskite, K3Cu3(Fe0.82Al0.18)O2(SO4)4 and
piipite, K4Cu4O2(SO4)4Cu0.5Cl) has been performed based on the structural data.
As seen from the calculation results, both minerals comprise
quasi-one-dimensional frustrated antiferromagnets. They contain frustrated spin
chains from edge-sharing Cu4 tetrahedra with strong antiferromagnetic couplings
within chains and very weak ones between chains. Strong frustration of magnetic
interactions is combined with the presence of the electric polarization in
tetrahedra chains in piipite. The uniqueness of magnetic structures of these
minerals caused by peculiarities of their crystal structures has been
discussed. Keywords: Frustrated quasi-one-dimensional antiferromagnets,
tetrahedral spin chains, klyuchevskite K3Cu3(Fe0.82Al0.18)O2(SO4)4, piypite
K4Cu4O2(SO4)4MeCl


title: Subjective Assessment of H.264 Compressed Stereoscopic Video

abstract:
  The tremendous growth in 3D (stereo) imaging and display technologies has led
to stereoscopic content (video and image) becoming increasingly popular.
However, both the subjective and the objective evaluation of stereoscopic video
content has not kept pace with the rapid growth of the content. Further, the
availability of standard stereoscopic video databases is also quite limited. In
this work, we attempt to alleviate these shortcomings. We present a
stereoscopic video database and its subjective evaluation. We have created a
database containing a set of 144 distorted videos. We limit our attention to
H.264 compression artifacts. The distorted videos were generated using 6
uncompressed pristine videos of left and right views originally created by
Goldmann et al. at EPFL [1]. Further, 19 subjects participated in the
subjective assessment task. Based on the subjective study, we have formulated a
relation between the 2D and stereoscopic subjective scores as a function of
compression rate and depth range. We have also evaluated the performance of
popular 2D and 3D image/video quality assessment (I/VQA) algorithms on our
database.


title: Distribution-free Multiple Testing

abstract:
  We study a stylized multiple testing problem where the test statistics are
independent and assumed to have the same distribution under their respective
null hypotheses. We first show that, in the normal means model where the test
statistics are normal Z-scores, the well-known method of (Benjamini and
Hochberg, 1995) is optimal in some asymptotic sense. We then show that this is
also the case of a recent distribution-free method proposed by Foygel-Barber
and Cand\`es (2015). The method is distribution-free in the sense that it is
agnostic to the null distribution - it only requires that the null distribution
be symmetric. We extend these optimality results to other location models with
a base distribution having fast-decaying tails.


title: Feedback-based Approach to Introduce Freshness in Recommendations

abstract:
  Recommender systems usually face the problem of serving the same
recommendations across multiple sessions regardless of whether the user is
interested in them or not, thereby reducing their effectiveness. To add
freshness to the recommended products, we introduce a feedback loop where the
set of recommended products in the current session depend on the user's
interaction with the previously recommended sets. We also describe ways of
addressing freshness when there is little or even no direct user interaction.
We define a metric to quantify freshness by reducing the problem to measuring
temporal diversity.


title: Weakly discontinuous and resolvable functions between topological spaces

abstract:
  We prove that a function $f:X\to Y$ from a first-countable (more generally,
Preiss-Simon) space $X$ to a regular space $Y$ is weakly discontinuous (which
means that every subspace $A\subset X$ contains an open dense subset $U\subset
A$ such that $f|U$ is continuous) if and only if $f$ is open-resolvable (in the
sense that for every open subset $U\subset Y$ the preimage $f^{-1}(U)$ is a
resolvable subset of $X$) if and only if $f$ is resolvable (in the sense that
for every resolvable subset $R\subset Y$ the preimage $f^{-1}(R)$ is a
resolvable subset of $X$). For functions on metrizable spaces this
characterization was announced (without proof) by Vinokurov in 1985.


title:
Topological properties preserved by weakly discontinuous maps and weak
  homeomorphisms

abstract:
  A map $f:X\to Y$ between topological spaces is called weakly discontinuous if
each subspace $A\subset X$ contains an open dense subspace $U\subset A$ such
that the restriction $f|U$ is continuous. A bijective map $f:X\to Y$ between
topological spaces is called a weak homeomorphism if $f$ and $f^{-1}$ are
weakly discontinuous. We study properties of topological spaces preserved by
weakly discontinuous maps and weak homeomorphisms. In particular, we show that
weak homeomorphisms preserve network weight, hereditary Lindel\"of number,
dimension. Also we classify infinite zero-dimensional $\sigma$-Polish
metrizable spaces up to a weak homeomorphism and prove that any such space $X$
is weakly homeomorphic to one of 9 spaces: $\omega$, $2^\omega$, $\mathbb
N^\omega$, $\mathbb Q$, $\mathbb Q\oplus 2^\omega$, $\mathbb Q\times 2^\omega$,
$\mathbb Q\oplus\mathbb N^\omega$, $(\mathbb Q\times 2^\omega)\oplus\mathbb
N^\omega$, $\mathbb Q\times\mathbb N^\omega$.


title:
Measurement of the Higgs boson mass and $e^+e^- \to ZH$ cross section
  using $Z \to \mu^+\mu^-$ and $Z \to e^+ e^-$ at the ILC

abstract:
  This paper presents a full simulation study of the measurement of the
production cross section ($\sigma_{\mathrm{ZH}}$) of the Higgsstrahlung process
$\mathrm{e^{+}e^{-}\rightarrow ZH}$ and the Higgs boson mass ($M_{\mathrm{H}}$)
at the International Linear Collider (ILC), using events in which a Higgs boson
recoils against a Z boson decaying into a pair of muons or electrons. The
analysis is carried out for three center-of-mass energies $\sqrt{s}$ = 250,
350, and 500 GeV, and two beam polarizations $\mathrm{e_{L}^{-}e_{R}^{+}}$ and
$\mathrm{e_{R}^{-}e_{L}^{+}}$, for which the polarizations of $\mathrm{e^{-}}$
and $\mathrm{e^{+}}$ are $\left(P\mathrm{e^{-}},P\mathrm{e^{+}}\right)$
=($-$80\%, +30\%) and (+80\%, $-$30\%), respectively. Assuming an integrated
luminosity of 250 $\mathrm{fb^{-1}}$ for each beam polarization at $\sqrt{s}$ =
250 GeV, where the best lepton momentum resolution is obtainable,
$\sigma_{\mathrm{ZH}}$ and $M_{\mathrm{H}}$ can be determined with a precision
of 2.5\% and 37 MeV for $\mathrm{e_{L}^{-}e_{R}^{+}}$ and 2.9\% and 41 MeV for
$\mathrm{e_{R}^{-}e_{L}^{+}}$, respectively. Regarding a 20 year ILC physics
program, the expected precisions for the $\mathrm{HZZ}$ coupling and
$M_{\mathrm{H}}$ are estimated to be 0.4\% and 14 MeV, respectively. The event
selection is designed to optimize the precisions of $\sigma_{\mathrm{ZH}}$ and
$M_{\mathrm{H}}$ while minimizing the bias on the measured
$\sigma_{\mathrm{ZH}}$ due to discrepancy in signal efficiencies among Higgs
decay modes. For the first time, model independence has been demonstrated to a
sub-percent level for the $\sigma_{\mathrm{ZH}}$ measurement at each of the
three center-of-mass energies. The results presented show the impact of
center-of-mass energy and beam polarization on the evaluated precisons and
serve as a benchmark for the planning of the ILC run scenario.


title:
Delay-Optimal Computation Task Scheduling for Mobile-Edge Computing
  Systems

abstract:
  Mobile-edge computing (MEC) emerges as a promising paradigm to improve the
quality of computation experience for mobile devices. Nevertheless, the design
of computation task scheduling policies for MEC systems inevitably encounters a
challenging two-timescale stochastic optimization problem. Specifically, in the
larger timescale, whether to execute a task locally at the mobile device or to
offload a task to the MEC server for cloud computing should be decided, while
in the smaller timescale, the transmission policy for the task input data
should adapt to the channel side information. In this paper, we adopt a Markov
decision process approach to handle this problem, where the computation tasks
are scheduled based on the queueing state of the task buffer, the execution
state of the local processing unit, as well as the state of the transmission
unit. By analyzing the average delay of each task and the average power
consumption at the mobile device, we formulate a power-constrained delay
minimization problem, and propose an efficient one-dimensional search algorithm
to find the optimal task scheduling policy. Simulation results are provided to
demonstrate the capability of the proposed optimal stochastic task scheduling
policy in achieving a shorter average execution delay compared to the baseline
policies.


title:
An improvement for the sharp Adams inequalities in bounded domains and
  whole space $\mathbb{R}^n$

abstract:
  We prove an improvement for the sharp Adams inequality in $W^{m,\frac
nm}_0(\Omega)$ where $\Omega$ is a bounded domain in $\mathbb{R}^n$ inspired by
Lions Concentration--Compactness principle for the sharp Moser--Trudinger
inequality. Our method gives an alternative approach to a
Concentration--Compactness principle in $W^{m,\frac nm}_0(\Omega)$ recently
established by do \'O and Macedo. Moreover, when $m$ is odd, we obtain an
improvement for their result by finding the best exponent in this principle.
Our approach also is successfully applied to whole space $\mathbb{R}^n$ to
establish an improvement for the sharp Adams inequalities in $W^{m,\frac
nm}(\mathbb{R}^n)$ due to Ruf, Sani, Lam, Lu, Fontana and Morpurgo. This type
of improvement is still unknown, in general, except the special case $m=1$ due
to do \'O, de Souza, de Medeiros and Severo. Our method is a further
development for the method of $\check{\rm C}$erny, Cianchi and Hencl combining
with some estimates for the decreasing rearrangement of a function in terms of
the one of its higher order derivatives.


title: Black holes with bottle-shaped horizons

abstract:
  We present a new class of four-dimensional AdS black holes with non-compact
event horizons of finite area. The event horizons are topologically spheres
with one puncture, with the puncture pushed to infinity in the form of a cusp.
Because of the shape of their event horizons, we call such black holes "black
bottles". The solution was obtained as a special case of the
Plebanski-Demianski solution, and may describe either static or rotating black
bottles. For certain ranges of parameters, an acceleration horizon may also
appear in the space-time. We study the full parameter space of the solution,
and the various limiting cases that arise. In particular, we show how the
rotating black hole recently discovered by Klemm arises as a special limit.


title:
Learning Deep Feature Representations with Domain Guided Dropout for
  Person Re-identification

abstract:
  Learning generic and robust feature representations with data from multiple
domains for the same problem is of great value, especially for the problems
that have multiple datasets but none of them are large enough to provide
abundant data variations. In this work, we present a pipeline for learning deep
feature representations from multiple domains with Convolutional Neural
Networks (CNNs). When training a CNN with data from all the domains, some
neurons learn representations shared across several domains, while some others
are effective only for a specific one. Based on this important observation, we
propose a Domain Guided Dropout algorithm to improve the feature learning
procedure. Experiments show the effectiveness of our pipeline and the proposed
algorithm. Our methods on the person re-identification problem outperform
state-of-the-art methods on multiple datasets by large margins.


title: Can Online Emotions Predict the Stock Market in China?

abstract:
  Whether the online social media, like Twitter or its variant Weibo, can be a
convincing proxy to predict the stock market has been debated for years,
especially for China. However, as the traditional theory in behavioral finance
states, the individual emotions can influence decision-making of investors, so
it is reasonable to further explore this controversial topic from the
perspective of online emotions, which is richly carried by massive tweets in
social media. Surprisingly, through thorough study on over 10 million
stock-relevant tweets from Weibo, both correlation analysis and causality test
show that five attributes of the stock market in China can be competently
predicted by various online emotions, like disgust, joy, sadness and fear.
Specifically, the presented model significantly outperforms the baseline
solutions on predicting five attributes of the stock market under the $K$-means
discretization. We also employ this model in the scenario of realistic online
application and its performance is further testified.