title:
The IPAC Image Subtraction and Discovery Pipeline for the intermediate
  Palomar Transient Factory

abstract:
  We describe the near real-time transient-source discovery engine for the
intermediate Palomar Transient Factory (iPTF), currently in operations at the
Infrared Processing and Analysis Center (IPAC), Caltech. We coin this system
the IPAC/iPTF Discovery Engine (or IDE). We review the algorithms used for
PSF-matching, image subtraction, detection, photometry, and machine-learned
(ML) vetting of extracted transient candidates. We also review the performance
of our ML classifier. For a limiting signal-to-noise ratio of 4 in relatively
unconfused regions, "bogus" candidates from processing artifacts and imperfect
image subtractions outnumber real transients by ~ 10:1. This can be
considerably higher for image data with inaccurate astrometric and/or
PSF-matching solutions. Despite this occasionally high contamination rate, the
ML classifier is able to identify real transients with an efficiency (or
completeness) of ~ 97% for a maximum tolerable false-positive rate of 1% when
classifying raw candidates. All subtraction-image metrics, source features, ML
probability-based real-bogus scores, contextual metadata from other surveys,
and possible associations with known Solar System objects are stored in a
relational database for retrieval by the various science working groups. We
review our efforts in mitigating false-positives and our experience in
optimizing the overall system in response to the multitude of science projects
underway with iPTF.


title:
Method for Computation of the Fisher Information Matrix in the
  Expectation-Maximization Algorithm

abstract:
  The expectation-maximization (EM) algorithm is an iterative computational
method to calculate the maximum likelihood estimators (MLEs) from the sample
data. It converts a complicated one-time calculation for the MLE of the
incomplete data to a series of relatively simple calculations for the MLEs of
the complete data. When the MLE is available, we naturally want the Fisher
information matrix (FIM) of unknown parameters. The FIM is, in fact, a good
measure of the amount of information a sample of data provides and can be used
to determine the lower bound of the variance and the asymptotic variance of the
estimators. However, one of the limitations of the EM is that the FIM is not an
automatic by-product of the algorithm. In this paper, we review some basic
ideas of the EM and the FIM. Then we construct a simple Monte Carlo-based
method requiring only the gradient values of the function we obtain from the E
step and basic operations. Finally, we conduct theoretical analysis and
numerical examples to show the efficiency of our method. The key part of our
method is to utilize the simultaneous perturbation stochastic approximation
method to approximate the Hessian matrix from the gradient of the conditional
expectation of the complete-data log-likelihood function. Key words: Fisher
information matrix, EM algorithm, Monte Carlo, Simultaneous perturbation
stochastic approximation


title: On the properties of tensor complementarity problems

abstract:
  Properties of solutions of the tensor complementarity problem (TCP) for
structured tensors have been investigated in recent literature. In this paper,
we make further contributions on this problem. Specifically, we first derive
solution existence theorems for TCPs on general cones from the results studied
in the nonlinear complementarity problem literature. An interesting byproduct
is that conditions (e.g., strict copositivity) of solution existence results
for TCPs on the nonnegative cone can be reduced to copositivity, which, to the
best of our knowledge, is the weakest requirement in the current TCP
literature. Moreover, we study the topological properties of the solution set
and stability of the TCP at a given solution, which are not discussed before
and further enrich the theory of TCPs.


title:
Quantile Regression for General Spatial Panel Data Models with Fixed
  Effects

abstract:
  This paper considers the quantile regression model with both individual fixed
effect and time period effect for general spatial panel data. Instrumental
variable quantile regression estimators will be proposed. Asymptotic properties
of the proposed estimators will be developed. Simulations are conducted to
study the performance of the proposed method. We will illustrate our
methodologies using a cigarettes demand data set.


title:
Linear Network Coding over Rings, Part II: Vector Codes and
  Non-Commutative Alphabets

abstract:
  We prove the following results regarding the linear solvability of networks
over various alphabets. For any network, the following are equivalent: (i)
vector linear solvability over some finite field, (ii) scalar linear
solvability over some ring, (iii) linear solvability over some module.
Analogously, the following are equivalent: (a) scalar linear solvability over
some finite field, (b) scalar linear solvability over some commutative ring,
(c) linear solvability over some module whose ring is commutative. Whenever any
network is linearly solvable over a module, a smallest such module arises in a
vector linear solution for that network over a field.
  If a network is linearly solvable over some non-commutative ring but not over
any commutative ring, then such a non-commutative ring must have size at least
$16$, and for some networks, this bound is achieved. An infinite family of
networks is demonstrated, each of which is scalar linearly solvable over some
non-commutative ring but not over any commutative ring.
  Whenever $p$ is prime and $2 \le k \le 6$, if a network is scalar linearly
solvable over some ring of size $p^k$, then it is also $k$-dimensional vector
linearly solvable over the field $GF(p)$, but the converse does not necessarily
hold. This result is extended to all $k\ge 2$ when the ring is commutative.


title:
Linear Network Coding over Rings, Part I: Scalar Codes and Commutative
  Alphabets

abstract:
  Fixed-size commutative rings are quasi-ordered such that all scalar linearly
solvable networks over any given ring are also scalar linearly solvable over
any higher-ordered ring. As consequences, if a network has a scalar linear
solution over some finite commutative ring, then (i) the network is also scalar
linearly solvable over a maximal commutative ring of the same size, and (ii)
the (unique) smallest size commutative ring over which the network has a scalar
linear solution is a field. We prove that a commutative ring is maximal with
respect to the quasi-order if and only if some network is scalar linearly
solvable over the ring but not over any other commutative ring of the same
size. Furthermore, we show that maximal commutative rings are direct products
of certain fields specified by the integer partitions of the prime factor
multiplicities of the maximal ring's size.
  Finally, we prove that there is a unique maximal commutative ring of size $m$
if and only if each prime factor of $m$ has multiplicity in $\{1,2,3,4,6\}$. In
fact, whenever $p$ is prime and $k \in \{1,2,3,4,6\}$, the unique such maximal
ring of size $p^k$ is the field $GF(p^k)$. However, for every field $GF(p^k)$
with $k\not\in \{1,2,3,4,6\}$, there is always some network that is not scalar
linearly solvable over the field but is scalar linearly solvable over a
commutative ring of the same size. These results imply that for scalar linear
network coding over commutative rings, fields can always be used when the
alphabet size is flexible, but alternative rings may be needed when the
alphabet size is fixed.


title:
Quantile Regression for Partially Linear Varying Coefficient Spatial
  Autoregressive Models

abstract:
  This paper considers the quantile regression approach for partially linear
spatial autoregressive models with possibly varying coefficients. B-spline is
employed for the approximation of varying coefficients. The instrumental
variable quantile regression approach is employed for parameter estimation. The
rank score tests are developed for hypotheses on the coefficients, including
the hypotheses on the non-varying coefficients and the constancy of the varying
coefficients. The asymptotic properties of the proposed estimators and test
statistics are both established. Monte Carlo simulations are conducted to study
the finite sample performance of the proposed method. Analysis of a real data
example is presented for illustration.


title:
Ubiquitous strong electron phonon coupling at the interface of
  FeSe/SrTiO3

abstract:
  The high temperature superconductivity in single-unit-cell (1UC) FeSe on
SrTiO3 (STO)(001) and the observation of replica bands by angle-resolved
photoemission spectroscopy (ARPES) have led to the conjecture that the coupling
between FeSe electron and the STO phonon is responsible for the enhancement of
Tc over other FeSe-based superconductors1,2. However the recent observation of
a similar superconducting gap in FeSe grown on the (110) surface of STO raises
the question of whether a similar mechanism applies3,4. Here we report the
ARPES study of the electronic structure of FeSe grown on STO(110). Similar to
the results in FeSe/STO(001), clear replica bands are observed. We also present
a comparative study of STO (001) and STO(110) bare surfaces, where photo doping
generates metallic surface states. Similar replica bands separating from the
main band by approximately the same energy are observed, indicating this
coupling is a generic feature of the STO surfaces and interfaces. Our findings
suggest that the large superconducting gaps observed in FeSe films grown on two
different STO surface terminations are likely enhanced by a common coupling
between FeSe electrons and STO phonons.


title:
Quasi-optimal convergence rate for an adaptive hybridizable C0
  discontinuous Galerkin method for Kirchhoff plates

abstract:
  In this paper, we present an adaptive hybridizable $C^0$ discontinuous
Galerkin (HCDG) method for Kirchhoff plates. A reliable and efficient a
posteriori error estimator is produced for this HCDG method.
Quasi-orthogonality and discrete reliability are established with the help of a
postprocessed bending moment and the discrete Helmholtz decomposition. Based on
these, the contraction property between two consecutive loops and complexity of
the adaptive HCDG method are studied thoroughly. The key points in our analysis
are a postprocessed normal-normal continuous bending moment from the HCDG
method solution and a lifting of jump residuals from inter-element boundaries
to element interiors.


title: Multi-bump solutions for logarithmic Schr\"odinger equations

abstract:
  We study spatially periodic logarithmic Schr\"odinger equations:
  \begin{equation}\tag{LS}
  -\Delta u + V(x)u=Q(x)u\log u^2, \quad u>0\quad \text{in}\ \mathbb{R}^N,
  \end{equation} where $N\geq 1$ and $V(x)$, $Q(x)$ are spatially $1$-periodic
functions of class $C^1$. We take an approach using spatially $2L$-periodic
problems ($L\gg 1$) and we show the existence of infinitely many multi-bump
solutions of $(LS)$ which are distinct under $\mathbb{Z}^N$-action.


title:
Cohomology of Commuting Varieties of Connected Compact Reductive Lie
  Groups

abstract:
  We calculate the rational cohomology of the commuting variety $X_{G, n}$
consisting of $n$-tuples of commuting elements of a compact reductive group
$G$. This is done by studying a map from a related variety $Y_{G, n}$, which
has easily calculated cohomology. The proof studies the fibers of the map and
uses the Vietoris-Begle theorem to prove that the induced map on rational
cohomology is an isomorphism.


title: Candidate Elastic Quantum Critical Point in LaCu$_{6-x}$Au$_x$

abstract:
  The structural properties of LaCu$_{6-x}$Au$_x$ have been studied using
neutron diffraction, x-ray diffraction, and heat capacity measurements. The
continuous orthorhombic-monoclinic structural phase transition in LaCu$_{6}$ is
suppressed linearly with Au substitution until a complete suppression of the
structural phase transition occurs at the critical composition, $x_{c}$ = 0.3.
Heat capacity measurements at low temperatures indicate residual structural
instability at $x_c$ that extends well into the orthorhombic phase. The
instability is ferroelastic in nature, with density functional theory (DFT)
calculations showing negligible coupling to electronic states near the Fermi
level. The data and calculations presented here are consistent with the zero
temperature termination of a continuous structural phase transition suggesting
that the LaCu$_{6-x}$Au$_x$ series hosts an elastic quantum critical point.


title: Play and Learn: Using Video Games to Train Computer Vision Models

abstract:
  Video games are a compelling source of annotated data as they can readily
provide fine-grained groundtruth for diverse tasks. However, it is not clear
whether the synthetically generated data has enough resemblance to the
real-world images to improve the performance of computer vision models in
practice. We present experiments assessing the effectiveness on real-world data
of systems trained on synthetic RGB images that are extracted from a video
game. We collected over 60000 synthetic samples from a modern video game with
similar conditions to the real-world CamVid and Cityscapes datasets. We provide
several experiments to demonstrate that the synthetically generated RGB images
can be used to improve the performance of deep neural networks on both image
segmentation and depth estimation. These results show that a convolutional
network trained on synthetic data achieves a similar test error to a network
that is trained on real-world data for dense image classification. Furthermore,
the synthetically generated RGB images can provide similar or better results
compared to the real-world datasets if a simple domain adaptation technique is
applied. Our results suggest that collaboration with game developers for an
accessible interface to gather data is potentially a fruitful direction for
future work in computer vision.


title:
Probing light-quark Yukawa couplings via hadronic event shapes at lepton
  colliders

abstract:
  We propose a novel idea for probing the Higgs boson couplings through the
measurement of hadronic event shape distributions in the decay of the Higgs
boson at lepton colliders. The method provides a unique test of the Higgs boson
couplings and of QCD effects in the decay of the Higgs boson. It can be used to
probe the Yukawa couplings of the light quarks and to further test the
mechanism of electroweak symmetry breaking. From a case study for the proposed
Circular Electron-Positron Collider, assuming a hypothesis of SM-like theory,
light-quark couplings with a strength greater than 9% of the bottom-quark
Yukawa coupling in the standard model can be excluded.


title:
A Distance for HMMs based on Aggregated Wasserstein Metric and State
  Registration

abstract:
  We propose a framework, named Aggregated Wasserstein, for computing a
dissimilarity measure or distance between two Hidden Markov Models with state
conditional distributions being Gaussian. For such HMMs, the marginal
distribution at any time spot follows a Gaussian mixture distribution, a fact
exploited to softly match, aka register, the states in two HMMs. We refer to
such HMMs as Gaussian mixture model-HMM (GMM-HMM). The registration of states
is inspired by the intrinsic relationship of optimal transport and the
Wasserstein metric between distributions. Specifically, the components of the
marginal GMMs are matched by solving an optimal transport problem where the
cost between components is the Wasserstein metric for Gaussian distributions.
The solution of the optimization problem is a fast approximation to the
Wasserstein metric between two GMMs. The new Aggregated Wasserstein distance is
a semi-metric and can be computed without generating Monte Carlo samples. It is
invariant to relabeling or permutation of the states. This distance quantifies
the dissimilarity of GMM-HMMs by measuring both the difference between the two
marginal GMMs and the difference between the two transition matrices. Our new
distance is tested on the tasks of retrieval and classification of time series.
Experiments on both synthetic data and real data have demonstrated its
advantages in terms of accuracy as well as efficiency in comparison with
existing distances based on the Kullback-Leibler divergence.


title:
Analogy between the "Hidden Order" and the Orbital Antiferromagnetism in
  URu$_{2-x}$Fe$_x$Si$_2$

abstract:
  We study URu$_{2-x}$Fe$_x$Si$_2$, in which two types of staggered phases
compete at low temperature as the iron concentration $x$ is varied: the
nonmagnetic "hidden order" (HO) phase below the critical concentration $x_c$,
and unconventional antiferromagnetic (AF) phase above $x_c$. By using
polarization resolved Raman spectroscopy, we detect a collective mode of
pseudovector-like $A_{2g}$ symmetry whose energy continuously evolves with
increasing $x$; it monotonically decreases in the HO phase until it vanishes at
$x=x_c$, and then reappears with increasing energy in the AF phase. The mode's
evolution provides direct evidence for unified order parameter for both
nonmagnetic and magnetic phases arising from the orbital degrees-of-freedom of
the uranium-5$f$ electrons.


title:
Foreground effect on the $J$-factor estimation of classical dwarf
  spheroidal galaxies

abstract:
  The gamma-ray observation of the dwarf spheroidal galaxies (dSphs) is a
promising approach to search for the dark matter annihilation (or decay)
signal. The dSphs are the nearby satellite galaxies with a clean environment
and dense dark matter halo so that they give stringent constraints on the 1 TeV
dark matter. However, recent studies have revealed that current estimation of
astrophysical factors relevant for the dark matter searches are not
conservative, where the various non-negligible systematic uncertainties are not
taken into account. Among them, the effect of foreground stars on the
astrophysical factors has not been paid much attention, which becomes more
important for deeper and wider stellar surveys in the future. In this article,
we assess the effects of the foreground contamination by generating the mock
samples of stars and using a model of future spectrographs. We investigate
various data cuts to optimize the quality of the data and find that the cuts on
the velocity and surface gravity can efficiently eliminate the contamination.
We also propose a new likelihood function which includes the foreground
distribution function. We apply this likelihood function to the fit of the
three types of the mock data (Ursa Minor, Draco with large dark matter halo,
and Draco with small halo) and three cases of the observation. The likelihood
successfully reproduces the input $J$-factor value while the fit without
considering the foreground distribution gives large deviation from the input
value by a factor of three.


title:
Transition from Amplitude Death to Oscillation Death in Coupled Chua
  Circuits

abstract:
  In this piece of work, an important transition from amplitude death (AD) to
oscillation death (OD) state in coupled Chua circuit has been explored for the
first time. Here, mean field diffusively (MFD) coupled Chua circuits are when
additionally coupled through direct coupling, it exhibits the AD-OD transition
phenomena. The effect of design parameters and coupling parameters are
investigated in details. For both identical and non-identical systems the AD
make transition to OD through symmetry breaking. These are investigated through
numerical simulations and are established through hardware experiment. The
present study includes a new dimension to versatility of Chua circuit in the
field of nonlinear dynamics.


title:
Crystallization and cooling conditions for diogenite formation in the
  turbulent magma ocean of asteroid 4 Vesta

abstract:
  Despite its small size, the asteroid 4 Vesta has been completely
differentiated to core and mantle. Its composition is similar to
howardite--eucrite--diogenite (HED) meteorites of which the detailed petrology
is known. Therefore, Vesta is a good target for understanding the
differentiation of terrestrial planets. A new differentiation model for crust
formation has been developed by taking magma ocean fluid dynamics, chemical
equilibrium, the presence of $^{26}$Al, and cooling into consideration with a
special focus on crystal separation. The role of crystal size, thickness of the
conductive lid, and fO$_{2}$ are evaluated as parameters. The results show that
large crystals of at least 1 cm settled and formed a kilometer-thick cumulate
layer of orthopyroxene with Mg$\#$ of 0.70-0.90 in ~20 thousand years, which
almost agrees with the Mg$\#$ of diogenites. Smaller grain sizes formed thinner
layers.


title:
Reheating mechanism of Curvaton with Nonminimal Derivative Coupling to
  Gravity

abstract:
  In this paper, we continue our study on the curvaton model with nonminimal
derivative coupling (NDC) to Einstein gravity proposed in our previous work,
focusing on the reheating mechanism. We found that according to whether the
curvaton has dominated the background after the end of inflation, it will have
two different behaviors of evolution, which should be the general property of
curvaton with nonminimal couplings. This will cause diffferent rates of
particle creation, which goes on via the parametric resonance process. The
reheating temperature is estimated for both cases in which reheating completes
before and after curvaton domination, and the constraints are quite loose
compared to that of overproduction of gravitino. Finally we investigated the
evolution of curvature perturbation during reheating. We have shown both
analytically and numerically that the curvature perturbation will not blow up
during the resonance process.


title: Sam2bam: High-Performance Framework for NGS Data Preprocessing Tools

abstract:
  This paper introduces a high-throughput software tool framework called {\it
sam2bam} that enables users to significantly speedup pre-processing for
next-generation sequencing data. The sam2bam is especially efficient on
single-node multi-core large-memory systems. It can reduce the runtime of data
pre-processing in marking duplicate reads on a single node system by 156-186x
compared with de facto standard tools. The sam2bam consists of parallel
software components that can fully utilize the multiple processors, available
memory, high-bandwidth of storage, and hardware compression accelerators if
available.
  The sam2bam provides file format conversion between well-known genome file
formats, from SAM to BAM, as a basic feature. Additional features such as
analyzing, filtering, and converting the input data are provided by {\it
plug-in} tools, e.g., duplicate marking, which can be attached to sam2bam at
runtime.
  We demonstrated that sam2bam could significantly reduce the runtime of NGS
data pre-processing from about two hours to about one minute for a whole-exome
data set on a 16-core single-node system using up to 130 GB of memory. The
sam2bam could reduce the runtime for whole-genome sequencing data from about 20
hours to about nine minutes on the same system using up to 711 GB of memory.


title: The equivariant Verlinde formula on the moduli of Higgs bundles

abstract:
  We prove an analog of the Verlinde formula on the moduli space of semistable
meromorphic G-Higgs bundles over a smooth curve for a reductive group G whose
fundamental group is free. The formula expresses the graded dimension of the
space of sections of a positive line bundle as a finite sum whose terms are
indexed by formal solutions of a generalized Bethe ansatz equation on the
maximal torus of G. In an appendix, Constantin Teleman proves a vanishing
theorem for the higher cohomology of positive line bundles on the stack of
Higgs bundles.


title: Formal Availability Analysis using Theorem Proving

abstract:
  Availability analysis is used to assess the possible failures and their
restoration process for a given system. This analysis involves the calculation
of instantaneous and steady-state availabilities of the individual system
components and the usage of this information along with the commonly used
availability modeling techniques, such as Availability Block Diagrams (ABD) and
Fault Trees (FTs) to determine the system-level availability. Traditionally,
availability analyses are conducted using paper-and-pencil methods and
simulation tools but they cannot ascertain absolute correctness due to their
inaccuracy limitations. As a complementary approach, we propose to use the
higher-order-logic theorem prover HOL4 to conduct the availability analysis of
safety-critical systems. For this purpose, we present a higher-order-logic
formalization of instantaneous and steady-state availability, ABD
configurations and generic unavailability FT gates. For illustration purposes,
these formalizations are utilized to conduct formal availability analysis of a
satellite solar array, which is used as the main source of power for the Dong
Fang Hong-3 (DFH-3) satellite.


title:
Fundamentals of the Downlink Green Coverage and Energy Efficiency in
  Heterogeneous Networks

abstract:
  This paper studies the proposed green (energy-efficient) coverage
probability, link and network energy efficiencies in the downlink of a
heterogeneous cellular network (HetNet) consisting of $K$ independent Poisson
point processes (PPPs) of base stations (BSs). The important statistical
properties of the universal (general) cell association functions are first
studied and the cell load statistics for power-law cell association functions,
which can characterize the accurate void cell probability of a BS in every
tier, is also derived. A simple and feasible green channel-aware cell
association (GCA) scheme is proposed and the green coverage probability is also
proposed for any particular cell association scheme, such as the maximum
received power association (MRPA) and nearest base station association (NBA)
schemes. Then the link and network energy efficiencies are proposed to
characterize the mean spectrum efficiency per unit power consumption for a BS
and the mean area spectrum efficiency for a HetNet, respectively. All the tight
bounds on the green coverage probability, link and network energy efficiencies
for the GCA, MRPA and NBA schemes are found. They are theoretically shown to
pose the fundamental maximum limits on the link and network energy efficiencies
achieved by any other cell association schemes and such a fact is validated by
numerical results as well.


title: Geometry-dependent viscosity reduction in sheared active fluids

abstract:
  We investigate flow pattern formation and viscosity reduction mechanisms in
active fluids by studying a generalized Navier-Stokes model that captures the
experimentally observed bulk vortex dynamics in microbial suspensions. We
present exact analytical solutions including stress-free vortex lattices and
introduce a computational framework that allows the efficient treatment of
previously intractable higher-order shear boundary conditions. Large-scale
parameter scans identify the conditions for spontaneous flow symmetry breaking,
geometry-dependent viscosity reduction and negative-viscosity states amenable
to energy harvesting in confined suspensions. The theory uses only generic
assumptions about the symmetries and long-wavelength structure of active stress
tensors, suggesting that inviscid phases may be achievable in a broad class of
non-equilibrium fluids by tuning confinement geometry and pattern scale
selection.


title:
Unitary similarity invariant function preservers of skew products of
  operators

abstract:
  Let ${\mathcal B}(H)$ denote the Banach algebra of all bounded linear
operators on a complex Hilbert space $H$ with $\dim H\geq 3$, and let $\mathcal
A$ and $\mathcal B$ be subsets of ${\mathcal B}(H)$ which contain all rank one
operators. Suppose $F(\cdot )$ is a unitary invariant norm, the pseudo spectra,
the pseudo spectral radius, the $C$-numerical range, or the $C$-numerical
radius for some finite rank operator $C$. The structure is determined for
surjective maps $\Phi :{\mathcal A}\rightarrow \mathcal B$ satisfying
$F(A^*B)=F(\Phi (A)^*\Phi (B))$ for all $A, B \in {\mathcal A}$. To establish
the proofs, some general results are obtained for functions $F:{\mathcal
F}_1(H) \cup \{0\} \rightarrow [0, +\infty)$, where ${\mathcal F}_1(H)$ is the
set of rank one operators in ${\mathcal B}(H)$, satisfying (a) $F(\mu
UAU^*)=F(A)$ for a complex unit $\mu$, $A\in {\mathcal F}_1(H)$ and unitary $U
\in {\mathcal B}(H)$ (b) for any rank one operator $X\in {\mathcal F}_1(H)$ the
map $t\mapsto F(tX)$ on $[0, \infty)$ is strictly increasing, and (c) the set
$\{F(X): X \in {\mathcal F}_1(H) \hbox{ and } \|X\| = 1\}$ attains its maximum
and minimum.


title:
Transient THz conductivity of silicon with optical pumping above and
  below the second indirect transition

abstract:
  Here we perform a series of time-resolved experiments where a 100 fs pump
pulse is tuned between 528 nm and 555 nm, across the second indirect gap of
intrinsic silicon at ~540 nm which involves electrons in a higher-lying
conduction band with minimum at the L point. The photo-injected carriers, after
inter- and intra-band relaxations are complete, are subsequently probed with
high-field single-cycle terahertz radiation. When the energy of the pump pulses
exceeds the second indirect gap, the probed terahertz absorption decreases by a
factor 2.7$\pm$0.2. We suggest that this dramatic change could be due to the
different phonon populations obtained when the carriers undergo the L to X
inter-band scattering, instead of just cooling within the X-valley.


title:
Investigative Simulation: Towards Utilizing Graph Pattern Matching for
  Investigative Search

abstract:
  This paper proposes the use of graph pattern matching for investigative graph
search, which is the process of searching for and prioritizing persons of
interest who may exhibit part or all of a pattern of suspicious behaviors or
connections. While there are a variety of applications, our principal
motivation is to aid law enforcement in the detection of homegrown violent
extremists. We introduce investigative simulation, which consists of several
necessary extensions to the existing dual simulation graph pattern matching
scheme in order to make it appropriate for intelligence analysts and law
enforcement officials. Specifically, we impose a categorical label structure on
nodes consistent with the nature of indicators in investigations, as well as
prune or complete search results to ensure sensibility and usefulness of
partial matches to analysts. Lastly, we introduce a natural top-k ranking
scheme that can help analysts prioritize investigative efforts. We demonstrate
performance of investigative simulation on a real-world large dataset.


title: The Verlinde formula for Higgs bundles

abstract:
  We propose and prove the Verlinde formula for the quantization of the Higgs
bundle moduli spaces and stacks for any simple and simply-connected group. This
generalizes the equivariant Verlinde formula for the case of $SU(n)$ proposed
previously by the second and third author. We further establish a Verlinde
formula for the quantization of parabolic Higgs bundle moduli spaces and
stacks. Finally, we prove that these dimensions form a one-parameter family of
$1+1$-dimensional TQFT, uniquely classified by the complex Verlinde algebra,
which is a one-parameter family of Frobenius algebras. We construct this
one-parameter family of Frobenius algebras as a deformation of the classical
Verlinde algebra for $G$.

categories: math.AG hep-th math-ph math.MP math.QA math.RT


title:
Universality of Dzyaloshinskii-Moriya interaction effect over
  domain-wall creep and flow regimes

abstract:
  Chirality causes diverse phenomena in nature such as the formation of
biological molecules, antimatters, non-collinear spin structures, and magnetic
skyrmions. The chirality in magnetic materials is often caused by the
noncollinear exchange interaction, called the Dzyaloshinskii-Moriya interaction
(DMI). The DMI produces topological spin alignments such as the magnetic
skyrmions and chiral domain walls (DWs). In the chiral DWs, the DMI generates
an effective magnetic field $H_{DMI}$, resulting in a peculiar DW speed
variation in the DW creep regime. However, the role of $H_{DMI}$ over the
different DW-dynamics regimes remains elusive, particularly due to recent
observation of distinct behaviors between the creep and flow regimes. We hereby
demonstrate experimentally that the role of $H_{DMI}$ is invariant over the
creep and flow regimes. In the experiments, the pure DMI effect is quantified
by decomposing the symmetric and antisymmetric contributions of the DW motion.
The results manifest that the antisymmetric contribution vanishes gradually
across the creep and flow regimes, revealing that the symmetric contribution
from $H_{DMI}$ is unchanged. Though the DW dynamics is governed by distinct
mechanisms, the present observation demonstrates the uniqueness of the DMI
effect on the DWs over the creep and flow regimes.


title:
ELUCID - Exploring the Local Universe with reConstructed Initial Density
  field III: Constrained Simulation in the SDSS Volume

abstract:
  A method we developed recently for the reconstruction of the initial density
field in the nearby Universe is applied to the Sloan Digital Sky Survey Data
Release 7. A high-resolution N-body constrained simulation (CS) of the
reconstructed initial condition, with $3072^3$ particles evolved in a 500 Mpc/h
box, is carried out and analyzed in terms of the statistical properties of the
final density field and its relation with the distribution of SDSS galaxies. We
find that the statistical properties of the cosmic web and the halo populations
are accurately reproduced in the CS. The galaxy density field is strongly
correlated with the CS density field, with a bias that depend on both galaxy
luminosity and color. Our further investigations show that the CS provides
robust quantities describing the environments within which the observed
galaxies and galaxy systems reside. Cosmic variance is greatly reduced in the
CS so that the statistical uncertainties can be controlled effectively even for
samples of small volumes.


title: Propagating degrees of freedom in f(R) gravity

abstract:
  We have computed the number of polarization modes of gravitational waves
propagating in the Minkowski background in $f(R)$ gravity. This is three of two
from transverse-traceless tensor modes and one from a massive trace mode, which
confirms the results found in the literature. There is no massless breathing
mode and the massive trace mode corresponds to the Ricci scalar. A newly
defined metric tensor in $f(R)$ gravity satisfies the transverse-traceless (TT)
condition as well as the TT wave equation.


title: Exact Russell-Type Modular Equations

abstract:
  This paper provides some statistics for the coefficients of Russell- Type
modular equations for the modular function, {\lambda}({\tau}). The results hold
uniformly for all odd primes. They do not rely on any numerical evaluations of
coefficients of q expansions of {\lambda}. The method relies on an internal
structure of the coefficients of {\lambda} expressed in terms of multiplicative
functions defined on integer partitions. The method may be extended to other
types of modular equations.


title: Asynchronous Rumor Spreading on Random Graphs

abstract:
  We perform a thorough study of various characteristics of the asynchronous
push-pull protocol for spreading a rumor on Erd\H{o}s-R\'enyi random graphs
$G_{n,p}$, for any $p>c\ln(n)/n$ with $c>1$. In particular, we provide a simple
strategy for analyzing the asynchronous push-pull protocol on arbitrary graph
topologies and apply this strategy to $G_{n,p}$. We prove tight bounds of
logarithmic order for the total time that is needed until the information has
spread to all nodes. Surprisingly, the time required by the asynchronous
push-pull protocol is asymptotically almost unaffected by the average degree of
the graph. Similarly tight bounds for Erd\H{o}s-R\'enyi random graphs have
previously only been obtained for the synchronous push protocol, where it has
been observed that the total running time increases significantly for sparse
random graphs. Finally, we quantify the robustness of the protocol with respect
to transmission and node failures. Our analysis suggests that the asynchronous
protocols are particularly robust with respect to these failures compared to
their synchronous counterparts.


title:
Effective equidistribution of periodic orbits for subshifts of finite
  type

abstract:
  We study equidistribution of certain subsets of periodic orbits for subshifts
of finite type. Our results solely rely on the growth of these subsets. As a
consequence, effective equidistribution results are obtained for both
hyperbolic diffeomorphisms and expanding maps on compact manifolds.


title:
Uncovering Circumbinary Planetary Architectural Properties from
  Selection Biases

abstract:
  The new discoveries of circumbinary planetary systems shed light on the
understanding of planetary system formation. Learning the architectural
properties of these systems is essential for constraining the different
formation mechanisms. We first revisit the stability limit of circumbinary
planets. Next, we focus on eclipsing stellar binaries and obtain an analytical
expression for the transit probability in a realistic setting, where finite
observation period and planetary orbital precession are included. Then,
understanding of the architectural properties of the currently observed
transiting systems is refined, based on Bayesian analysis and a series of
hypothesis tests. We find 1) it is not a selection bias that the innermost
planets reside near the stability limit for eight of the nine observed systems,
and this is consistent with a log uniform distribution of the planetary
semi-major axis; 2) it is not a selection bias that the planetary and stellar
orbits are nearly coplanar ($\lesssim 3^\circ$), and this together with
previous studies may imply an occurrence rate of circumbinary planets similar
to that of single star systems; 3) the dominance of observed circumbinary
systems with only one transiting planet may be caused by selection effects; 4)
formation mechanisms involving Lidov-Kozai oscillations, which may produce
misalignment and large separation between planet and stellar binaries, are
consistent with the lack of transiting circumbinary planets around short-period
stellar binaries, in agreement with previous studies. As a consequence of 4),
eclipse timing variations may better suit the detection of planets in such
configurations.


title: Deep Learning the City : Quantifying Urban Perception At A Global Scale

abstract:
  Computer vision methods that quantify the perception of urban environment are
increasingly being used to study the relationship between a city's physical
appearance and the behavior and health of its residents. Yet, the throughput of
current methods is too limited to quantify the perception of cities across the
world. To tackle this challenge, we introduce a new crowdsourced dataset
containing 110,988 images from 56 cities, and 1,170,000 pairwise comparisons
provided by 81,630 online volunteers along six perceptual attributes: safe,
lively, boring, wealthy, depressing, and beautiful. Using this data, we train a
Siamese-like convolutional neural architecture, which learns from a joint
classification and ranking loss, to predict human judgments of pairwise image
comparisons. Our results show that crowdsourcing combined with neural networks
can produce urban perception data at the global scale.


title:
Algebraic K-theory of finitely projective modules on
  $\mathbb{E}_{\infty}$-rings

abstract:
  In this paper, we study the K-theory on higher modules in spectral algebraic
geometry. We relate the K-theory of an $\infty$-category of finitely generated
projective modules on certain $\mathbb{E}_{\infty}$-rings with the K-theory of
an ordinary category of finitely generated projective modules on ordinary
rings.


title:
Community Detection in Political Twitter Networks using Nonnegative
  Matrix Factorization Methods

abstract:
  Community detection is a fundamental task in social network analysis. In this
paper, first we develop an endorsement filtered user connectivity network by
utilizing Heider's structural balance theory and certain Twitter triad
patterns. Next, we develop three Nonnegative Matrix Factorization frameworks to
investigate the contributions of different types of user connectivity and
content information in community detection. We show that user content and
endorsement filtered connectivity information are complementary to each other
in clustering politically motivated users into pure political communities. Word
usage is the strongest indicator of users' political orientation among all
content categories. Incorporating user-word matrix and word similarity
regularizer provides the missing link in connectivity only methods which suffer
from detection of artificially large number of clusters for Twitter networks.


title:
Contribution of Neutron Star Mergers to the R-process Chemical Evolution
  in the Hierarchical Galaxy Formation

abstract:
  The main astronomical source of r-process elements has not yet been
identified. One plausible site is neutron star mergers (NSMs), but from
perspective of the Galactic chemical evolution, it has been pointed out that
NSMs cannot reproduce the observed r-process abundance distribution of
metal-poor stars at [Fe/H] $< -3$. Recently, Tsujimoto & Shigeyama (2014)
pointed out that NSM ejecta can spread into much larger volume than ejecta from
a supernova. We re-examine the enrichment of r-process elements by NSMs
considering this difference in propagation using the chemical evolution model
under the hierarchical galaxy formation. The observed r-process enhanced stars
around [Fe/H] $\sim -3$ are reproduced if the star formation efficiency is
lower for low-mass galaxies under a realistic delay time distribution for NSMs.
We show that a significant fraction of NSM ejecta escape from its host
proto-galaxy to pollute intergalactic matter and other proto-galaxies. The
propagation of r-process elements over proto-galaxies changes the abundance
distribution at [Fe/H] $< -3$ and obtains distribution compatible with
observations of the Milky Way halo stars. In particular, the pre-enrichment of
intergalactic medium explains the observed scarcity of EMP stars without Ba and
abundance distribution of r-process elements at [Fe/H] $\lesssim -3.5$.


title: Radial limits and boundary uniqueness

abstract:
  The paper sheds a new light on the fundamental theorems of complex analysis
due to P. Fatou, F. and M. Riesz, N. N. Lusin, I. I. Privalov, and A. Beurling.
Only classical tools available at the times of Fatou are used. The proofs are
very simple and in some cases - almost trivial.


title: Superconductivity in palladium hydride and deuteride at 52-61 kelvin

abstract:
  We report the observation of conventional superconductivity at the highest
temperature yet attained without mechanical compression, around 54 kelvin in
palladium-hydride and 60 kelvin in palladium-deuteride. The remarkable increase
in Tc compared to the previously known value was achieved by rapidly cooling
the hydride and deuteride after loading with hydrogen or deuterium at elevated
temperature. Our results encourage hope that conventional superconductivity
under ambient conditions will be discovered in materials with very high
hydrogen density, as predicted more than a decade ago.


abstract:
  An iterative formula for the Kostka-Foulkes polynomials is given using the
vertex operator realization of the Hall-Littlewood polynomials. The operational
formula can handle large Kostka-Foulkes polynomials, and a stability property
for the Kostka-Foulkes polynomials is shown. We also use our algorithm to give
a formula of $K_{\lambda\mu}(t)$ for $\mu$ being hook-shaped.


title: Swing amplification and global modes reciprocity in models with cusps

abstract:
  Using 3D N-body simulations we analyse an onset of the bar in cuspy models,
and argue that role of swing amplification is twofold. Amplified shot noise due
to disc discreteness hampers bar formation, while induced resonance
perturbations allow bar amplitude to overcome shots. A bar pattern speed and a
growth rate obtained in N-body simulations agree well with global mode
analysis.


title: Phase Estimation of Coherent States with a Noiseless Linear Amplifier

abstract:
  Amplification of quantum states is inevitably accompanied with the
introduction of noise at the output. For protocols that are probabilistic with
heralded success, noiseless linear amplification in theory may still possible.
When the protocol is successful, it can lead to an output that is a noiselessly
amplified copy of the input. When the protocol is unsuccessful, the output
state is degraded and is usually discarded. Probabilistic protocols may improve
the performance of some quantum information protocols, but not for metrology if
the whole statistics is taken into consideration. We calculate the precision
limits on estimating the phase of coherent states using a noiseless linear
amplifier by computing its quantum Fisher information and we show that on
average, the noiseless linear amplifier does not improve the phase estimate. We
also discuss the case where abstention from measurement can reduce the cost for
estimation.


title:
Extrasolar giant magnetospheric response to steady-state stellar wind
  pressure at 10, 5, 1, and 0.2 AU

abstract:
  A three-dimensional, multifluid simulation of a giant planet's magnetospheric
interaction with steady-state stellar wind from a Sun-like star was performed
for four different orbital semi-major axes - 10, 5, 1 and 0.2 AU. We simulate
the effect of the increasing, steady-state stellar wind pressure related to the
planetary orbital semi-major axis on the global magnetospheric dynamics for a
Saturn-like planet, including an Enceladus-like plasma torus. Mass loss
processes are shown to vary with orbital distance, with the centrifugal
interchange instability displayed only in the 10 AU and 5 AU cases which reach
a state of mass loss equilibrium more slowly than the 1 AU or 0.2 AU cases. The
compression of the magnetosphere in the 1 AU and 0.2 AU cases contributes to
the quenching of the interchange process by increasing the ratio of total
plasma thermal energy to corotational energy. The strength of field-aligned
currents (FAC), associated with auroral radio emissions, are shown to increase
in magnitude and latitudinal coverage with a corresponding shift equatorward
from increased dynamic ram pressure experienced in the hotter orbits. Similar
to observed hot Jovian planets, the warm exo-Saturn simulated in the current
work shows enhanced ion density in the magnetosheath and magnetopause regions,
as well as the plasma torus which could contribute to altered transit signals,
suggesting that for planets in warmer ($>$0.1 AU) orbits, planetary magnetic
field strengths and possibly exomoons - via the plasma torus - could be
observable with future missions.


title:
NMR captures preformed Cooper pairs persisting far beyond Tc in organic
  superconductors

abstract:
  High critical temperature (high-Tc) superconductivity in copper oxides
emerges when Mott insulators are doped, and various unconventional properties
follow. Among them, a focus is the so-called pseudogap behaviour emerging above
Tc, which is discussed in association with competing orders, Fermi-arc and
preformed Cooper pairs. Besides doping, there is another way to generate
unconventional superconductivity from Mott insulators, that is, by bandwidth
control, which involves varying the particle's kinetic energy instead of
particle number. Here, working with layered organic superconductors through NMR
experiments, we uncover that in the non-doped case anomalous suppression of
spin excitations above Tc arises from the preformed Cooper pairs intertwined
with antiferromagnetic spin fluctuations and is not accompanied by complexities
of competing orders, unlike what is observed in copper oxides. On the verge of
the Mott localization of electrons, they preform Cooper pairs that persist up
to twice as high as Tc.


title: A Substellar Companion to Pleiades HII 3441

abstract:
  We find a new substellar companion to the Pleiades member star, Pleiades HII
3441, using the Subaru telescope with adaptive optics. The discovery is made as
part of the high-contrast imaging survey to search for planetary-mass and
substellar companions in the Pleiades and young moving groups. The companion
has a projected separation of 0".49 +/- 0".02 (66 +/- 2 AU) and a mass of 68
+/- 5 M_J based on three observations in the J-, H-, and K_S-band. The spectral
type is estimated to be M7 (~2700 K), and thus no methane absorption is
detected in the H band. Our Pleiades observations result in the detection of
two substellar companions including one previously reported among 20 observed
Pleiades stars, and indicate that the fraction of substellar companions in the
Pleiades is about 10.0 +26.1/-8.8 %. This is consistent with multiplicity
studies of both the Pleiades stars and other open clusters.


title:
Lower order and higher order entanglement in $87Rb$ $5S-5P-5D$ hyperfine
  manifold modeled as a four-wave mixing process

abstract:
  Possibilities of generation of lower order and higher order intermodal
entanglement in 87Rb 5S-5P-5D hyperfine manifold are rigorously investigated
using Sen-Mandal perturbative technique by showing the equivalence of the
system with the four-wave mixing (FWM) process. The investigation has revealed
that for a set of experimentally realizable/relevant parameters we can observe
lower order and higher order intermodal entanglement between pump and signal
modes, signal and idler modes, and idler and pump modes in a FWM process
associated with the 87Rb 5S-5P-5D hyperfine manifold. In addition, trimodal
entanglement involving pump, signal and idler modes is also reported.


title: The Toeplitz noncommutative solenoid and its KMS states

abstract:
  We use Katsura's topological graphs to define Toeplitz extensions of
Latr\'emoli\`ere and Packer's noncommutative-solenoid C*-algebras. We identify
a natural dynamics on each Toeplitz noncommutative solenoid and study the
associated KMS states. Our main result shows that the space of extreme points
of the KMS simplex of the Toeplitz noncommutative torus at a strictly positive
inverse temperature is homeomorphic to a solenoid; indeed, there is an action
of the solenoid group on the Toeplitz noncommutative solenoid that induces a
free and transitive action on the extreme boundary of the KMS simplex. With the
exception of the degenerate case of trivial rotations, at inverse temperature
zero there is a unique KMS state, and only this one factors through
Latr\'emoli\`ere and Packer's noncommutative solenoid.


title:
The Evolutionary Process of Image Transition in Conjunction with Box and
  Strip Mutation

abstract:
  Evolutionary algorithms have been used in many ways to generate digital art.
We study how evolutionary processes are used for evolutionary art and present a
new approach to the transition of images. Our main idea is to define
evolutionary processes for digital image transition, combining different
variants of mutation and evolutionary mechanisms. We introduce box and strip
mutation operators which are specifically designed for image transition. Our
experimental results show that the process of an evolutionary algorithm in
combination with these mutation operators can be used as a valuable way to
produce unique generative art.


title: The Breuil--M\'{e}zard conjecture when $l \neq p$

abstract:
  Let $l$ and $p$ be primes, let $F/\mathbb{Q}_p$ be a finite extension with
absolute Galois group $G_F$, let $\mathbb{F}$ be a finite field of
characteristic $l$, and let $\bar{\rho} : G_F \rightarrow GL_n(\mathbb{F})$ be
a continuous representation. Let $R^\square(\bar{\rho})$ be the universal
framed deformation ring for $\bar{\rho}$. If $l = p$, then the
Breuil--M\'{e}zard conjecture (as formulated by Emerton and Gee) relates the
mod $l$ reduction of certain cycles in $R^\square(\bar{\rho})$ to the mod $l$
reduction of certain representations of $GL_n(\mathcal{O}_F)$. We state an
analogue of the Breuil--M\'{e}zard conjecture when $l \neq p$, and prove it
whenever $l > 2$ using automorphy lifting theorems. We give a local proof when
$l$ is "quasi-banal" for $F$ and $\bar{\rho}$ is tamely ramified. We also
analyse the reduction modulo $l$ of the types $\sigma(\tau)$ defined by
Schneider and Zink.


title: Molecular Model Checking a Temporal Logic

abstract:
  The molecular computing has been successfully employed to solve more and more
complex computation problems. However, as an important complex problem, the
model checking are still far from fully resolved under the circumstance of
molecular computing, since it is still a lack of method. To address this issue,
a model checking method is presented for checking the basic constructs in a
given temporal logic using molecular computing. Through the design of the new
encoding and calling this process, we get a molecule-based approach for
checking all of the basic constructs of this logic.


title: Effect of Burstiness on the Air Transportation System

abstract:
  The effect of burstiness in complex networks has received considerable
attention. In particular, its effect on temporal distance and delays in the air
transportation system is significant owing to their huge impact on our society.
Therefore, in this paper, we propose two indexes of temporal distance based on
passengers' behavior and analyze the effect. As a result, we find that
burstiness shortens the temporal distance while delays are increased. Moreover,
we discover that the positive effect of burstiness is lost when flight
schedules get overcrowded.


title:
A randomization-based perspective of analysis of variance: a test
  statistic robust to treatment effect heterogeneity

abstract:
  Fisher randomization tests for Neyman's null hypothesis of no average
treatment effects are considered in a finite population setting associated with
completely randomized experiments with more than two treatments. The
consequences of using the $F$ statistic to conduct such a test are examined
both theoretically and computationally, and it is argued that under treatment
effect heterogeneity, use of the $F$ statistic in the Fisher randomization test
can severely inflate the type I error under Neyman's null hypothesis. An
alternative test statistic is proposed, its asymptotic distributions under
Fisher's and Neyman's null hypotheses are derived, and its advantages
demonstrated.


title:
On the Imminent Regional Seismic Activity Forecasting Using INTERMAGNET
  and Sun-Moon Tide Code Data

abstract:
  In this paper we present an approach for forecasting the imminent regional
seismic activity by using geomagnetic data and Earth tide data. The time
periods of seismic activity are the time periods around the Sun-Moon extreme of
the diurnal average value of the tide vector module. For analyzing the
geomagnetic data behaviour we use diurnal standard deviation of geomagnetic
vector components F for calculating the time variance Geomag Signal. The Sun
storm influence is avoided by using data for daily A-indexes (published by
NOAA). The precursor signal for forecasting the incoming regional seismic
activity is a simple function of the present and previous day Geomag Signal and
A-indexes values. The reliability of the geomagnetic when, regional precursor
is demonstrated by using statistical analysis of day difference between the
times of predicted and occurred earthquakes. The base of the analysis is a
natural hypothesis that the predicted earthquake is the one whose surface
energy density in the monitoring point is bigger than the energy densities of
all occurred earthquakes in the same period and region. The reliability of the
approach was tested using the INTERMAGNET stations data located in Bulgaria,
Panagurishte, PAG (Jan 1, 2008-Jan 29, 2014), Romania, Surlari, SUA (Jan 1,
2008-Jan 27, 2014), Italy, L'Aquila, AQU (Jan 1, 2008-May 30, 2013) in the time
of EU IRSES BlackSeaHazNet (2011-2014) project. The steps of program for
solving the when, where and how earthquake prediction problem are shortly
described.


title: The Tradeoff Analysis in RF-Powered Backscatter Cognitive Radio Networks

abstract:
  In this paper, we introduce a new model for RF-powered cognitive radio
networks with the aim to improve the performance for secondary systems. In our
proposed model, when the primary channel is busy, the secondary transmitter is
able either to backscatter the primary signals to transmit data to the
secondary receiver or to harvest RF energy from the channel. The harvested
energy then will be used to transmit data to the receiver when the channel
becomes idle. We first analyze the tradeoff between backscatter communication
and harvest-then-transmit protocol in the network. To maximize the overall
transmission rate of the secondary network, we formulate an optimization
problem to find time ratio between taking backscatter and harvest-then-transmit
modes. Through numerical results, we show that under the proposed model can
achieve the overall transmission rate higher than using either the backscatter
communication or the harvest-then-transmit protocol.


title: Coverage in Heterogeneous Downlink Millimeter Wave Cellular Networks

abstract:
  In this paper, we provide an analytical framework to analyze heterogeneous
downlink mmWave cellular networks consisting of K tiers of randomly located
base stations (BSs) where each tier operates in a mmWave frequency band.
Signal-to-interference-plus-noise ratio (SINR) coverage probability is derived
for the entire network using tools from stochastic geometry. The distinguishing
features of mmWave communications such as directional beamforming and having
different path loss laws for line-of-sight (LOS) and non-line-of-sight (NLOS)
links are incorporated into the coverage analysis by assuming averaged biased
received power association and Nakagami-m fading. By using the noise-limited
assumption for mmWave networks, a simpler expression requiring the computation
of only one numerical integral for coverage probability is obtained. Also,
effect of beamforming alignment errors on the coverage probability analysis is
investigated to get insight on the performance in practical scenarios. Downlink
rate coverage probability is derived as well to get more insights on the
performance of the network. Moreover, effect of deploying low-power smaller
cells and effect of biasing factor on energy efficiency is analyzed. Finally, a
hybrid cellular network operating in both mmWave and microWave frequency bands
is addressed.


title: Towards boolean operations with thermal photons

abstract:
  The Boolean algebra is the natural theoretical framework for a classical
information treatment. The basic logical operations are usually performed using
logic gates. In this Letter we demonstrate that NOT, OR and AND gates can be
realized exploiting the near-field radiative interaction in N-body systems with
phase change materials. With the recent development of a photon thermal
transistor and thermal memory, this result paves the way for a full information
treatment and smart solutions for active thermal management at nanoscale with
photons.


title:
Seismic metasurfaces: Sub-wavelength resonators and Rayleigh wave
  interaction

abstract:
  We consider the canonical problem of an array of rods, which act as
resonators, placed on an elastic substrate; the substrate being either a thin
elastic plate or an elastic half-space. In both cases the flexural plate, or
Rayleigh surface, waves in the substrate interact with the resonators to create
interesting effects such as effective band-gaps for surface waves or filters
that transform surface waves into bulk waves; these effects have parallels in
the field of optics where such sub-wavelength resonators create metamaterials,
and metasurfaces, in the bulk and at the surface respectively.
  Here we carefully analyse this canonical problem by extracting the dispersion
relations analytically thereby examining the influence of both the flexural and
compressional resonances on the propagating wave. For an array of resonators
atop an elastic half-space we augment the analysis with numerical simulations.
Amongst other effects, we demonstrate the striking effect of a dispersion curve
that transitions from Rayleigh wave-like to shear wave-like behaviour and the
resultant change in displacement from surface to bulk waves.


title: Sparse Subspace Clustering via Diffusion Process

abstract:
  Subspace clustering refers to the problem of clustering high-dimensional data
that lie in a union of low-dimensional subspaces. State-of-the-art subspace
clustering methods are based on the idea of expressing each data point as a
linear combination of other data points while regularizing the matrix of
coefficients with L1, L2 or nuclear norms for a sparse solution. L1
regularization is guaranteed to give a subspace-preserving affinity (i.e.,
there are no connections between points from different subspaces) under broad
theoretical conditions, but the clusters may not be fully connected. L2 and
nuclear norm regularization often improve connectivity, but give a
subspace-preserving affinity only for independent subspaces. Mixed L1, L2 and
nuclear norm regularization could offer a balance between the
subspace-preserving and connectedness properties, but this comes at the cost of
increased computational complexity. This paper focuses on using L1 norm and
alleviating the corresponding connectivity problem by a simple yet efficient
diffusion process on subspace affinity graphs. Without adding any tuning
parameter , our method can achieve state-of-the-art clustering performance on
Hopkins 155 and Extended Yale B data sets.


title: Incompatibility of quantum channels

abstract:
  Two quantum channels are called compatible if they can be obtained as
marginals from a single broadcasting channel; otherwise they are incompatible.
We derive a characterization of the compatibility relation in terms of
concatenation and conjugation, and we show that all pairs of sufficiently noisy
quantum channels are compatible. The complement relation of incompatibility can
be seen as a unifying aspect for many quantum features. We demonstrate that
several phenomena, such as impossibility of universal broadcasting and
unavoidable measurement disturbance, appear naturally in this framework.


title: A diffusion approximation for limit order book models

abstract:
  This paper derives a diffusion approximation for a sequence of discrete-time
one-sided limit order book models with non-linear state dependent order arrival
and cancellation dynamics. The discrete time sequences are specified in terms
of an $\R_+$-valued best bid price process and an $L^2_{loc}$-valued volume
process. It is shown that under suitable assumptions the sequence of
interpolated discrete time models is relatively compact in a localized sense
and that any limit point satisfies a certain infinite dimensional SDE. Under
additional assumptions on the dependence structure we construct two classes of
models, which fit in the general framework, such that the limiting SDE admits a
unique solution and thus the discrete dynamics converge to a diffusion limit in
a localized sense.


title:
Phase transition of generalized two dimensional Yang-Mills U(N) on the
  sphere for $G(z)=z^4+\lambda\,z^3$ and Maxwell construction

abstract:
  The large-N behavior of the quartic-cubic generalized two dimensional
Yang-Mills U(N) on the sphere is investigated for finite cubic couplings.
First, it is shown that there are two phase transitions one of which is third
order and the other one is second order. Second, $gYM_2$ and Maxwell
construction are compared and a relationship between two-dimensional
space-time, that is purely mathematical, and four-dimensional space-time is
obtained.


title:
Hodge-Dirac, Hodge-Laplacian and Hodge-Stokes operators in L^p spaces on
  Lipschitz domains

abstract:
  This paper concerns Hodge-Dirac operators D = d + $\delta$ acting in L p
($\Omega$, {\lambda}) where $\Omega$ is a bounded open subset of R n satisfying
some kind of Lipschitz condition, {\lambda} is the exterior algebra of R n , d
is the exterior derivative acting on the de Rham complex of differential forms
on $\Omega$, and $\delta$ is the interior derivative with tangential boundary
conditions. In L 2 ($\Omega$, {\lambda}), $\delta$ = d * and D is self-adjoint,
thus having bounded resolvents (I + itD) --1 t$\in$R as well as a bounded
functional calculus in L 2 ($\Omega$, {\lambda}). We investigate the range of
values p H \textless{} p \textless{} p H about p = 2 for which D has bounded
resolvents and a bounded holomorphic functional calculus in L p ($\Omega$,
{\lambda}). On domains which we call very weakly Lipschitz, we show that this
is the same range of values as for which L p ($\Omega$, {\lambda}) has a Hodge
(or Helmholz) decomposition, being an open interval that includes 2. The
Hodge-Laplacian {\Delta} is the square of the Hodge-Dirac operator, i.e.
--{\Delta} = D 2 , so it also has a bounded functional calculus in L p
($\Omega$, {\lambda}) when p H \textless{} p \textless{} p H. But the Stokes
operator with Hodge boundary conditions, which is the restriction of --{\Delta}
to the subspace of divergence free vector fields in L p ($\Omega$, {\lambda} 1)
with tangential boundary conditions , has a bounded holomorphic functional
calculus for further values of p, namely for max{1, p H S } \textless{} p
\textless{} p H where p H S is the Sobolev exponent below p H , given by 1/p H
S = 1/p H + 1/n, so that p H S \textless{} 2n/(n + 2). In 3 dimensions, p H S
\textless{} 6/5. We show also that for bounded strongly Lipschitz domains
$\Omega$, p H \textless{} 2n/(n + 1) \textless{} 2n/(n -- 1) \textless{} p H ,
in agreement with the known results that p H \textless{} 4/3 \textless{} 4
\textless{} p H in dimension 2, and p H \textless{} 3/2 \textless{} 3
\textless{} p H in dimension 3. In both dimensions 2 and 3, p H S \textless{} 1
, implying that the Stokes operator has a bounded functional calculus in L p
($\Omega$, {\lambda} 1) when $\Omega$ is strongly Lipschitz and 1 \textless{} p
\textless{} p H .


title: Superradiant instability in AdS

abstract:
  The phenomenon of superradiance in the context of asymptotically global AdS
spacetimes is investigated with particular accent on its effect on the
stability of the systems under consideration. To this end, the concept of an
asymptotically AdS spacetime is explained, together with its implications on
the boundary conditions at $\mathcal{I}$, as well as the
Newman-Penrose-Teukolsky formalism, whereby the Teukolsky master equation in a
most general form for Kerr-AdS is given. Furthermore, work done in the cases of
RN-AdS and Kerr-AdS is laid out in a concise manner, putting emphasis on the
important steps taken in determining the endpoint of the superradiant
instability in the two configurations. For the former this turns out to be a
black hole with reduced charge and a static charged scalar condensate around
it, whereas for the latter two of the more probable outcomes are presented,
both of which imply a violation of one of the cosmic censorships.


title: Second Phase transition line

abstract:
  We study the phase transion line of the almost Mathieu operator, that
separates arithmetic regions corresponding to singular continuous and a.e. pure
point regimes, and prove that both purely singular continuous and a.e. pure
point spectrum occur for dense sets of frequencies.


title: Applications of the loop-tree duality

abstract:
  We describe a new method to perform NLO calculations, combining real and
virtual amplitudes at the integrand level, with a fully local compensation
between them in the IR, and between the virtual integrand and properly defined
counter-terms in the UV, in such a way that physical observables can be
computed in 4 dimensions. One of the advantages of the method is that all the
scattering amplitudes are integrated simultaneously, without the need for
tensor reduction, or projection onto sets of master integrals. As such, it
could offer great progress in the automation of NLO calculations, where the
actual bottle-necks are the complexity of the analytical calculations for
multi-leg processes, and the numerical stability of the result.


title: Detection Thresholds for the $\beta$-Model on Sparse Graphs

abstract:
  In this paper we study sharp thresholds for detecting sparse signals in
$\beta$-models for potentially sparse random graphs. The results demonstrate
interesting interplay between graph sparsity, signal sparsity, and signal
strength. In regimes of moderately dense signals, irrespective of graph
sparsity, the detection thresholds mirror corresponding results in independent
Gaussian sequence problems. For sparser signals, extreme graph sparsity implies
that all tests are asymptotically powerless, irrespective of the signal
strength. On the other hand, sharp detection thresholds are obtained, up to
matching constants, on denser graphs. The phase transition mentioned above are
sharp. As a crucial ingredient, we study a version of the Higher Criticism Test
which is provably sharp up to optimal constants in the regime of sparse
signals. The theoretical results are further verified by numerical simulations.


title:
Three-body calculation of the $1s$ level shift in kaonic deuterium with
  realistic $\bar{K}N$ potentials

abstract:
  The $1s$ level shift in kaonic deuterium was calculated using Coulomb
Sturmian expansion of Faddeev equations. The convergence of the method yields
an $\sim\ 1\ eV$ accuracy for the level shifts. We used three different,
realistic, multichannel $\bar{K}N$ interactions reproducing all known
experimental two-body $\bar{K}N$ data. The different results suggest, that the
level shift should be in the range $\Delta E\sim(800\pm30)-(480\pm20){\rm i}\ \
eV$. The (almost) exact level shifts were compared with values, given by the
commonly used approximations.


title: Relative Asymptotics of Orthogonal Polynomials for Perturbed Measures

abstract:
  In the context of orthogonal polynomials in the plane we introduce the notion
of a polynomially small (PS) perturbation of a measure. In such a case we
establish relative asymptotic results for the two sequences of the associated
orthonormal polynomials. We also provide results dealing with the behaviour of
the zeros of PS perturbations of area orthogonal (Bergman) polynomials.


title: `imaka - a ground-layer adaptive optics system on Maunakea

abstract:
  We present the integration status for `imaka, the ground-layer adaptive
optics (GLAO) system on the University of Hawaii 2.2-meter telescope on
Maunakea, Hawaii. This wide-field GLAO pathfinder system exploits Maunakea's
highly confined ground layer and weak free-atmosphere to push the corrected
field of view to ~1/3 of a degree, an areal field approaching an order of
magnitude larger than any existing or planned GLAO system, with a FWHM ~ 0.33
arcseconds in the visible and near infrared. We discuss the unique design
aspects of the instrument, the driving science cases and how they impact the
system, and how we will demonstrate these cases on the sky.


title: R\'enyi divergence and the central limit theorem

abstract:
  We explore properties of the $\chi^2$ and more general R\'enyi (Tsallis)
distances to the normal law. In particular we provide necessary and sufficient
conditions for the convergence to the normal law in the central limit theorem
using these distances. Moreover, we derive exact rates of convergence in these
distances with respect to an increasing number of summands.


title:
Heterodyne photodetection measurements on cavity optomechanical systems:
  Interpretation of sideband asymmetry and limits to a classical explanation

abstract:
  We consider a system where an optical cavity mode is parametrically coupled
to a mechanical oscillator. A laser beam driving the cavity at its resonance
frequency will acquire red- and blue-shifted sidebands due to noise in the
position of the mechanical oscillator. In a classical theory without noise in
the electromagnetic field, the powers of these sidebands are of equal
magnitude. In a quantum theory, however, an asymmetry between the sidebands can
be resolved when the oscillator's average number of vibrational excitations
(phonons) becomes small, i.e., comparable to 1. We discuss the interpretation
of this sideband asymmetry in a heterodyne photodetection measurement scheme
and show that it depends on the choice of detector model. In the optical
regime, standard photodetection theory leads to a photocurrent noise spectrum
given by normal and time ordered expectation values. The sideband asymmetry is
in that case a direct reflection of the quantum asymmetry of the position noise
spectrum of the mechanical oscillator. Conversely, for a detector that measures
symmetric, non-ordered expectation values, we show that the sideband asymmetry
can be traced back to quantum optomechanical interference terms. This ambiguity
in interpretation applies not only to mechanical oscillators, but to any degree
of freedom that couples linearly to noise in the electromagnetic field.
Finally, we also compare the quantum theory to a fully classical model, where
sideband asymmetry can arise from classical optomechanical interference terms.
We show that, due to the oscillator's lack of zero point motion in a classical
theory, the sidebands in the photocurrent spectrum differ qualitatively from
those of a quantum theory at sufficiently low temperatures. We discuss the
observable consequences of this deviaton between classical and quantum
theories.


title: SIFT Meets CNN: A Decade Survey of Instance Retrieval

abstract:
  In the early days, content-based image retrieval (CBIR) was studied with
global features. Since 2003, image retrieval based on local descriptors (de
facto SIFT) has been extensively studied for over a decade due to the advantage
of SIFT in dealing with image transformations. Recently, image representations
based on the convolutional neural network (CNN) have attracted increasing
interest in the community and demonstrated impressive performance. Given this
time of rapid evolution, this article provides a comprehensive survey of
instance retrieval over the last decade. Two broad categories, SIFT-based and
CNN-based methods, are presented. For the former, according to the codebook
size, we organize the literature into using large/medium-sized/small codebooks.
For the latter, we discuss three lines of methods, i.e., using pre-trained or
fine-tuned CNN models, and hybrid methods. The first two perform a single-pass
of an image to the network, while the last category employs a patch-based
feature extraction scheme. This survey presents milestones in modern instance
retrieval, reviews a broad selection of previous works in different categories,
and provides insights on the connection between SIFT and CNN-based methods.
After analyzing and comparing retrieval performance of different categories on
several datasets, we discuss promising directions towards generic and
specialized instance retrieval.


title:
Discovery of A New Retrograde Trans-Neptunian Object: Hint of A Common
  Orbital Plane for Low Semi-Major Axis, High Inclination TNOs and Centaurs

abstract:
  Although the majority of Centaurs are thought to have originated in the
scattered disk, with the high-inclination members coming from the Oort cloud,
the origin of the high inclination component of trans-Neptunian objects (TNOs)
remains uncertain. We report the discovery of a retrograde TNO, which we
nickname "Niku", detected by the Pan-STARRS 1 Outer Solar System Survey. Our
numerical integrations show that the orbital dynamics of Niku are very similar
to that of 2008 KV$_{42}$ (Drac), with a half-life of $\sim 500$ Myr. Comparing
similar high inclination TNOs and Centaurs ($q > 10$ AU, $a < 100$ AU and $i >
60^\circ$), we find that these objects exhibit a surprising clustering of
ascending node, and occupy a common orbital plane. This orbital configuration
has high statistical significance: 3.8-$\sigma$. An unknown mechanism is
required to explain the observed clustering. This discovery may provide a
pathway to investigate a possible reservoir of high-inclination objects.


title:
Renormalized parameters and perturbation theory in dynamical mean-field
  theory for the Hubbard model

abstract:
  We calculate the renormalized parameters for the quasiparticles and their
interactions for the Hubbard model in the paramagnetic phase as deduced from
the low energy Fermi liquid fixed point using the results of a numerical
renormalization group calculation (NRG) and dynamical mean-field theory (DMFT).
Even in the low density limit there is significant renormalization of the local
quasiparticle interaction $\tilde U$, in agreement with estimates based on the
two-particle scattering theory of Kanamori (1963). On the approach to the Mott
transition we find a finite ratio for $\tilde U/\tilde D$, where $2\tilde D$ is
the renormalized bandwidth, which is independent of whether the transition is
approached by increasing the on-site interaction $U$ or on increasing the
density to half-filling.The leading $\omega^2$ term in the self-energy and the
local dynamical spin and charge susceptibilities are calculated within the
renormalized perturbation theory (RPT) and compared with the results calculated
directly from the NRG-DMFT. The dynamic ${\bf q},\omega$ spin susceptibility
$\chi({\bf q},\omega)$ is also estimated from repeated quasiparticle scattering
with a local renormalized scattering vertex.


title: On solutions for the b-family of peakon equations

abstract:
  We investigate a family of peakon equations, labelled by two parameters $b$
and $\kappa$, all of which admit one-peakon solutions in a unified form. The
well known Camassa-Holm equation and Degasperis-Procesi equation are derived
from the b-family peakon equations by choosing $b=2$ and 3, respectively. For
all values of $b$, their two peakon-type solutions are shown in difference form
and in weak sense. At the same time, the dynamic behaviors are shown in
difference phenomenons, such as the peaked waves collide elastically in the
case $b=2$, while the peaked waves collide inelastically in other cases.


title:
Measuring evolution of a photon in an interferometer with
  spectrally-resolved modes

abstract:
  In the year 2013, Danan et al. published a paper [Phys. Rev. Lett. 111,
240402 (2013)] demonstrating a counterintuitive behavior of photons in nested
Mach-Zehnder interferometers. The authors then proposed an explanation based on
the two-state vector formalism. This experiment and the authors' explanation
raised a vivid debate within the scientific community. In this paper, we
contribute to the ongoing debate by presenting an alternative experimental
implementation of the Danan et al. scheme. We show that no counterintuitive
behavior is observed when performing direct spectrally-resolved detection.


title: A new two-variable generalization of the Jones polynomial

abstract:
  We present a new 2-variable generalization of the Jones polynomial that can
be defined through the skein relation of the Jones polynomial. The
well-definedness of this new generalization is proved both algebraically and
diagrammatically as well as via a closed combinatorial formula. This new
invariant is able to distinguish more pairs of non-isotopic links than the
original Jones polynomial such as the Thistlethwaite link from the unlink with
two components.


title: On supercurrents in Bose-Einstein magnon condensates in YIG ferrimagnet

abstract:
  Recently E. Sonin commented [1] on our preprint "Supercurrent in a room
temperature Bose-Einstein magnon condensate" [2,3], arguing that our "claim of
detection of spin supercurrent is premature and has not been sufficiently
supported by presented experimental results and their theoretical
interpretation." We consider the appearance of this Comment as a sign of
significant interest into the problem of supercurrents in Bose-Einstein magnon
condensates. Here, we explicitly address E. Sonin's comments and show that our
interpretation of our experimental results as a detection of a magnon
supercurrent is fully supported not only by the experimental results
themselves, but also by independent theoretical analysis [4].


title: Quantum teleportation with continuous measurements

abstract:
  We propose a scheme for quantum teleportation between two qubits, coupled
sequentially to a cavity field. An implementation of the scheme is analyzed
with superconducting qubits and a transmission line resonator, where
measurements are restricted to continuous probing of the field leaking from the
resonator rather than instantaneous projective Bell state measurement. We show
that the past quantum state formalism [S. Gammelmark et al, Phys. Rev. 111,
160401] can be successfully applied to estimate what would have been the most
likely Bell measurement outcome conditioned on our continuous signal record.
This information determines which local operation on the target qubit yields
the optimal teleportation fidelity. Our results emphasize the significance of
applying a detailed analysis of quantum measurements in feed-forward protocols
in non-ideal leaky quantum systems.


title: Stability and instability towards delocalization in MBL systems

abstract:
  We propose a theory that describes quantitatively the (in)stability of fully
MBL systems due to ergodic, i.e. delocalized, grains, that can be for example
due to disorder fluctuations. The theory is based on the ETH hypothesis and
elementary notions of perturbation theory. The main idea is that we assume as
much chaoticity as is consistent with conservation laws. The theory describes
correctly -even without relying on the theory of local integrals of motion
(LIOM)- the MBL phase in 1 dimension at strong disorder. It yields an explicit
and quantitative picture of the spatial boundary between localized and ergodic
systems. We provide numerical evidence for this picture.
  When the theory is taken to its extreme logical consequences, it predicts
that the MBL phase is destabilised in the long time limit whenever 1)
interactions decay slower than exponentially in $d=1$ and 2) always in $d>1$.
Finer numerics is required to assess these predictions.


title:
Back-propagating the light of field stars to probe telescope mirrors
  aberrations

abstract:
  We propose a wavefront-based method to estimate the PSF over the whole field
of view. This method estimate the aberrations of all the mirrors of the
telescope using only field stars. In this proof of concept paper, we described
the method and present some qualitative results.


title:
First-order phase transitions in spinor Bose gases and frustrated
  magnets

abstract:
  We show that phase transitions in spin-one Bose gases and stacked triangular
Heisenberg antiferromagnets -- an example of frustrated magnets with competing
interactions -- are described by the same Landau-Ginzburg-Wilson Hamiltonian
with O(3)$\times$O(2) symmetry. In agreement with previous
nonperturbative-renormalization-group studies of the three-dimensional
O(3)$\times$O(2) model, we find that the transition from the normal phase to
the superfluid ferromagnetic phase in a spin-one Bose gas is weakly first order
and shows pseudoscaling behavior. The (nonuniversal) pseudoscaling exponent
$\nu$ is fully determined by the scattering lengths $a_0$ and $a_2$. We provide
estimates of $\nu$ in $^{87}$Rb, $^{41}$K and $^7$Li atom gases which can be
tested experimentally. We argue that pseudoscaling comes from either a
crossover phenomena due to proximity of the O(6) Wilson-Fisher fixed point
($^{87}$Rb and $^{41}$K) or the existence of two unphysical fixed points (with
complex coordinates) which slow down the RG flow ($^7$Li). These unphysical
fixed points are a remnant of the chiral and antichiral fixed points that exist
in the O($N$)$\times$O(2) model when $N$ is larger than $N_c\simeq 5.3$ (the
transition being then second order and controlled by the chiral fixed point).
Finally, we discuss a O(2)$\times$O(2) lattice model and show that our results,
even though we find the transition to be first order, are compatible with Monte
Carlo simulations yielding an apparent second-order transition.


title:
The BioDynaMo Project: a platform for computer simulations of biological
  dynamics

abstract:
  This paper is a brief update on developments in the BioDynaMo project, a new
platform for computer simulations for biological research. We will discuss the
new capabilities of the simulator, important new concepts simulation
methodology as well as its numerous applications to the computational biology
and nanoscience communities.


title: How unusual is the cool-core radio halo cluster CL1821+643 ?

abstract:
  Massive galaxy clusters with cool-cores typically host diffuse radio sources
called mini-haloes, whereas, those with non-cool-cores host radio haloes. We
attempt to understand the unusual nature of the cool-core galaxy cluster
CL1821+643 that hosts a Mpc-scale radio halo using new radio observations and
morphological analysis of its intra-cluster medium. We present the Giant
Metrewave Radio Telescope (GMRT) 610 MHz image of the radio halo. The spectral
index, $\alpha$ defined as $S\propto \nu^{-\alpha}$, of the radio halo is
$1.0\pm0.1$ over the frequency range of 323 - 610 - 1665 MHz. Archival {\it
Chandra} X-ray data were used to make surface brightness and temperature maps.
The morphological parameters Gini, $M_{20}$ and concentration ($C$) were
calculated on X-ray surface brightness maps by including and excluding the
central quasar (H1821+643) in the cluster. We find that the cluster CL1821+643,
excluding the quasar, is a non-relaxed cluster as seen in the morphological
parameter planes. It occupies the same region as other merging radio halo
clusters in the temperature- morphology parameter plane. We conclude that this
cluster has experienced a non-core-disruptive merger.


title: Bounded Clique-Width of ($S_{1,2,2}$,Triangle)-Free Graphs

abstract:
  If a graph has no induced subgraph isomorphic to $H_1$ or $H_2$ then it is
said to be ($H_1,H_2$)-free. Dabrowski and Paulusma found 13 open cases for the
question whether the clique-width of ($H_1,H_2$)-free graphs is bounded. One of
them is the class of ($S_{1,2,2}$,triangle)-free graphs. In this paper we show
that these graphs have bounded clique-width. Thus, also
($P_1+2P_2$,triangle)-free graphs have bounded clique-width which solves
another open problem of Dabrowski and Paulusma. Meanwhile we were informed by
Paulusma that in December 2015, Dabrowski, Dross and Paulusma showed that
($S_{1,2,2}$,triangle)-free graphs (and some other graph classes) have bounded
clique-width.


title: Entopy-energy inequality for superconducting qutrit

abstract:
  We compare the entropy-energy inequality and the von Neumann entropic
inequality for three level atom implemented on superconducting circuits with
Josephson junction. The positivity of entropy and energy relations for the
qutrit system are used for verification of state tomography of qudit systems.
The results obtained are valid for generic quantum states (qudits) and are
illustrated on the example of the temperature density matrix of the single
qutrit state.


title:
Modulational instability in nonlocal Kerr media with sine-oscillatory
  response

abstract:
  We discuss the modulational instability (MI) of plane waves in nonlocal Kerr
media with the sine-oscillation response function, which can model the nematic
liquid crystal with negative dielectric anisotropy. The results in the
framework of the nonlocal nonlinear Schr\"{o}dinger equation show that the MI
in this system has two extraordinary properties. First, MI exists in both cases
of negative Kerr coefficient $(n_{2}<0)$ and positive Kerr coefficient
$(n_{2}>0)$. Second, the maximum gain of MI is not affected by the intensity of
the plane wave, and the wave number %spatial frequency of the maximum gain
depends on the oscillation period of the response function. We also explore,
for the first time to the best of our knowledge, the physical mechanism of MI
in the framework of the four-wave mixing (FWM). %FWM interaction. By
introducing a phase mismatch term $\triangle k$ and a (nonlinear) growth factor
$\gamma$ (both of them have clear physical meanings), we find that the
necessary and sufficient condition for the MI appearance is that the phase
mismatching during the FWM process should be small enough such that $|\triangle
k|<2|\gamma|$. Basing on the discover, we present a new scenario to uniformly
and consistently explain why the MI can happen for the focusing local Kerr
media and cannot for the defocusing local Kerr media, as well as the MI
phenomena in the nonlocal cases.


title: Skewness of elliptic flow fluctuations

abstract:
  Using event-by-event hydrodynamic calculations, we find that the fluctuations
of the elliptic flow ($v_2$) in the reaction plane have a negative skew. We
compare the skewness of $v_2$ fluctuations to that of initial eccentricity
fluctuations. We show that skewness is the main effect lifting the degeneracy
between higher-order cumulants, with negative skew corresponding to the
hierarchy $v_2\{4\}>v_2\{6\}$ observed in Pb+Pb collisions at the LHC. We
describe how the skewness can be measured experimentally and show that
hydrodynamics naturally reproduces its magnitude and centrality dependence.


title:
The Le Cam distance between density estimation, Poisson processes and
  Gaussian white noise

abstract:
  It is well-known that density estimation on the unit interval is
asymptotically equivalent to a Gaussian white noise experiment, provided the
densities have H\"older smoothness larger than $1/2$ and are uniformly bounded
away from zero. We derive matching lower and constructive upper bounds for the
Le Cam deficiencies between these experiments, with explicit dependence on both
the sample size and the size of the densities in the parameter space. As a
consequence, we derive sharp conditions on how small the densities can be for
asymptotic equivalence to hold. The related case of Poisson intensity
estimation is also treated.


title:
Compartmental analysis of dynamic nuclear medicine data: regularization
  procedure and application to physiology

abstract:
  Compartmental models based on tracer mass balance are extensively used in
clinical and pre-clinical nuclear medicine in order to obtain quantitative
information on tracer metabolism in the biological tissue. This paper is the
second of a series of two that deal with the problem of tracer coefficient
estimation via compartmental modelling in an inverse problem framework. While
the previous work was devoted to the discussion of identifiability issues for
2, 3 and n-dimension compartmental systems, here we discuss the problem of
numerically determining the tracer coefficients by means of a general
regularized Multivariate Gauss Newton scheme. In this paper, applications
concerning cerebral, hepatic and renal functions are considered, involving
experimental measurements on FDG-PET data on different set of murine models.


title: Minimal regularity solutions of semilinear generalized Tricomi equations

abstract:
  We prove the local existence and uniqueness of minimal regularity solutions
$u$ of the semilinear generalized Tricomi equation $\partial_t^2 u-t^m \Delta u
=F(u)$ with initial data $(u(0,\cdot), \partial_t u(0,\cdot)) \in
\dot{H^{\gamma}}(\mathbb R^n) \times \dot{H}^{\gamma-\frac2{m+2}}(\mathbb R^n)$
under the assumption that $|F(u)|\lesssim |u|^\kappa$ and $|F'(u)| \lesssim
|u|^{\kappa -1}$ for some $\kappa>1$. Our results improve previous results of
M. Beals [2] and of ourselves [15-17]. We establish Strichartz-type estimates
for the linear generalized Tricomi operator $\partial_t^2 -t^m \Delta$ from
which the semilinear results are derived.


title: Cooperative Wi-Fi Deployment: A One-to-Many Bargaining Framework

abstract:
  We study the cooperation of the mobile network operator (MNO) and the venue
owners (VOs) on the public Wi-Fi deployment. We consider a one-to-many
bargaining framework, where the MNO bargains with VOs sequentially to determine
where to deploy Wi-Fi and how much to pay. Taking into account the negative
externalities among different steps of bargaining, we analyze the following two
cases: for the exogenous bargaining sequence case, we compute the optimal
bargaining solution on the cooperation decisions and payments under a
predetermined bargaining sequence; for the endogenous bargaining sequence case,
the MNO decides the bargaining sequence to maximize its payoff. Through
exploring the structural property of the optimal bargaining sequence, we design
a low-complexity Optimal VO Bargaining Sequencing (OVBS) algorithm to search
the optimal sequence. More specifically, we categorize the VOs into three types
based on the impact of the Wi-Fi deployment at their venues, and show that it
is optimal for the MNO to bargain with these three types of VOs sequentially.
Numerical results show that compared with the random and worst bargaining
sequences, the optimal bargaining sequence improves the MNO's payoff by up to
14.8% and 45.3%, respectively.


title: Energy-Efficient UAV Communication with Trajectory Optimization

abstract:
  Wireless communication with unmanned aerial vehicles (UAVs) is a promising
technology for future communication systems. In this paper, we study
energy-efficient UAV communication with a ground terminal via optimizing the
UAV's trajectory, a new design paradigm that jointly considers both the
communication throughput and the UAV's energy consumption. To this end, we
first derive a theoretical model on the propulsion energy consumption of
fixed-wing UAVs as a function of the UAV's flying speed, direction and
acceleration, based on which the energy efficiency of UAV communication is
defined. Then, for the case of unconstrained trajectory optimization, we show
that both the rate-maximization and energy-minimization designs lead to
vanishing energy efficiency and thus are energy-inefficient in general. Next,
we introduce a practical circular UAV trajectory, under which the UAV's flight
radius and speed are optimized to maximize the energy efficiency for
communication. Furthermore, an efficient design is proposed for maximizing the
UAV's energy efficiency with general constraints on its trajectory, including
its initial/final locations and velocities, as well as maximum speed and
acceleration. Numerical results show that the proposed designs achieve
significantly higher energy efficiency for UAV communication as compared with
other benchmark schemes.


title:
Giant superconducting fluctuations in the compensated semimetal FeSe at
  the BCS-BEC crossover

abstract:
  The physics of the crossover between weak-coupling Bardeen-Cooper-Schrieffer
(BCS) and strong-coupling Bose-Einstein-condensate (BEC) limits gives a unified
framework of quantum bound (superfluid) states of interacting fermions. This
crossover has been studied in the ultracold atomic systems, but is extremely
difficult to be realized for electrons in solids. Recently, the superconducting
semimetal FeSe with a transition temperature $T_{\rm c}=8.5$ K has been found
to be deep inside the BCS-BEC crossover regime. Here we report experimental
signatures of preformed Cooper pairing in FeSe below $T^*\sim20$ K, whose
energy scale is comparable to the Fermi energies. In stark contrast to usual
superconductors, large nonlinear diamagnetism by far exceeding the standard
Gaussian superconducting fluctuations is observed below $T^*\sim20$ K,
providing thermodynamic evidence for prevailing phase fluctuations of
superconductivity. Nuclear magnetic resonance (NMR) and transport data give
evidence of pseudogap formation at $\sim T^*$. The multiband superconductivity
along with electron-hole compensation in FeSe may highlight a novel aspect of
the BCS-BEC crossover physics.


title:
Precise Measurement of Magnetic Field Gradients from Free Spin
  Precession Signals of $^{3}$He and $^{129}$Xe Magnetometers

abstract:
  We report on precise measurements of magnetic field gradients extracted from
transverse relaxation rates of precessing spin samples. The experimental
approach is based on the free precession of gaseous, nuclear spin polarized
$^3$He and $^{129}$Xe atoms in a spherical cell inside a magnetic guiding field
of about 400 nT using LT$_C$ SQUIDs as low-noise magnetic flux detectors. The
transverse relaxation rates of both spin species are simultaneously monitored
as magnetic field gradients are varied. For transverse relaxation times
reaching 100 h, the residual longitudinal field gradient across the spin sample
could be deduced to be$|\vec{\nabla}B_z|=(5.6 \pm 0.4)$ pT/cm. The method takes
advantage of the high signal-to-noise ratio with which the decaying spin
precession signal can be monitored that finally leads to the exceptional
accuracy to determine magnetic field gradients at the sub pT/cm scale.


title:
A global view of velocity fluctuations in the corona below 1.3 $R_\odot$
  with CoMP

abstract:
  The Coronal Multi-channel Polarimeter (CoMP) has previously demonstrated the
presence of Doppler velocity fluctuations in the solar corona. The observed
fluctuations are thought to be transverse waves, i.e. highly incompressible
motions whose restoring force is dominated by the magnetic tension, some of
which demonstrate clear periodicity. We aim to exploit CoMP's ability to
provide high cadence observations of the off-limb corona to investigate the
properties of velocity fluctuations in a range of coronal features, providing
insight into how(if) the properties of the waves are influenced by the varying
magnetic topology in active regions, quiet Sun and open fields regions. An
analysis of Doppler velocity time-series of the solar corona from the
$10,747$~{\AA} Iron XIII line is performed, determining the velocity power
spectra and using it as a tool to probe wave behaviour. Further, the average
phase speed and density for each region are estimated and used to compute the
spectra for energy density and energy flux. In addition, we assess the noise
levels associated with the CoMP data, deriving analytic formulae for the
uncertainty on Doppler velocity measurements and providing a comparison by
estimating the noise from the data. It is found that the entire corona is
replete with transverse wave behaviour. The corresponding power spectra
indicates that the observed velocity fluctuations are predominately generated
by stochastic processes, with the spectral slope of the power varying between
the different magnetic regions. Most strikingly, all power spectra reveal the
presence of enhanced power occurring at $ \sim3$~mHz, potentially implying that
the excitation of coronal transverse waves by $p$-modes is a global phenomenon.