title:
On the existence of solutions to stochastic quasi-variational inequality
  and complementarity problems

abstract:
  Variational inequality problems allow for capturing an expansive class of
problems, including convex optimization problems, convex Nash games and
economic equilibrium problems, amongst others. Yet in most practical settings,
such problems are complicated by uncertainty, motivating the examination of a
stochastic generalization of the variational inequality problem and its
extensions in which the components of the mapping contain expectations. When
the associated sets are unbounded, ascertaining existence requires having
access to analytical forms of the expectations. Naturally, in practical
settings, such expressions are often difficult to derive, severely limiting the
applicability of such an approach. Consequently, our goal lies in developing
techniques that obviate the need for integration and our emphasis lies in
developing tractable and verifiable sufficiency conditions for claiming
existence. We begin by recapping almost-sure sufficiency conditions for
stochastic variational inequality problems with single-valued maps provided in
our prior work [44] and provide extensions to multi-valued mappings. Next, we
extend these statements to quasi-variational regimes where maps can be either
single or set-valued. Finally, we refine the obtained results to accommodate
stochastic complementarity problems where the maps are either general or
co-coercive. The applicability of our results is demonstrated on practically
occurring instances of stochastic quasi-variational inequality problems and
stochastic complementarity problems, arising as nonsmooth generalized
Nash-Cournot games and power markets, respectively.


title: Analog Turbo Codes: Turning Chaos to Reliability

abstract:
  Analog error correction codes, by relaxing the source space and the codeword
space from discrete fields to continuous fields, present a generalization of
digital codes. While linear codes are sufficient for digital codes, they are
not for analog codes, and hence nonlinear mappings must be employed to fully
harness the power of analog codes. This paper demonstrates new ways of building
effective (nonlinear) analog codes from a special class of nonlinear,
fast-diverging functions known as the chaotic functions. It is shown that the
"butterfly effect" of the chaotic functions matches elegantly with the distance
expansion condition required for error correction, and that the useful idea in
digital turbo codes can be exploited to construct efficient turbo-like chaotic
analog codes. Simulations show that the new analog codes can perform on par
with, or better than, their digital counter-parts when transmitting analog
sources.


title: Medium induced Lorentz symmetry breaking effects in nonlocal PNJL models

abstract:
  In this paper we detail the thermodynamics of two flavor nonlocal
Polyakov-Nambu-Jona-Lasinio models for different parametrizations of the quark
interaction regulators. The structure of the model is upgraded in order to
allow for terms in the quark selfenergy which violate Lorentz invariance due to
the presence of the medium. We examine the critical properties, the phase
diagram as well as the equation of state. Furthermore, some aspects of the Mott
effect for pions and sigma mesons are discussed explicitly within a nonlocal
Polyakov-Nambu-Jona-Lasinio model. In particular, we continued the meson
polarization function in the complex energy plane and under certain
approximations, we were able to extract the imaginary part as a function of the
meson energy. We were not able to calculate the dynamical meson mass, and
therefore resorted to a technical study of the temperature dependence of the
meson width by replacing the meson energy with the temperature dependent
spatial meson mass. Our results show that while the temperature behavior of the
meson widths is qualitatively the same for a wide class of covariant
regulators, the special case where the nonlocal interactions are introduced via
the instanton liquid model singles out with a drastically different behavior.


title: Spectral and Parametric Averaging for Integrable Systems

abstract:
  We analyze two theoretical approaches to ensemble averaging for integrable
systems in quantum chaos - spectral averaging and parametric averaging. For
spectral averaging, we introduce a new procedure - rescaled spectral averaging.
Unlike traditional spectral averaging, it can describe the correlation function
of spectral staircase and produce persistent oscillations of the interval level
number variance. Parametric averaging, while not as accurate as rescaled
spectral averaging for the correlation function of spectral staircase and
interval level number variance, can also produce persistent oscillations of the
global level number variance and better describes saturation level rigidity as
a function of the running energy. Overall, it is the most reliable method for a
wide range of statistics.


title: Mixed stochastic delay differential equations

abstract:
  We consider a stochastic delay differential equation driven by a Holder
continuous process and a Wiener process. Under fairly general assumptions on
its coefficients, we prove that this equation is uniquely solvable. We also
give sufficient conditions for finiteness of its moments and establish a limit
theorem.


title: Complete Cosmic History with a dynamical Lambda(H) term

abstract:
  In the present mainstream cosmology, matter and spacetime emerged from a
singularity and evolved through four distinct periods: early inflation,
radiation, dark matter and late-time inflation (driven by dark energy). During
the radiation and dark matter dominated stages, the universe is decelerating
while the early and late-time inflations are accelerating stages. A possible
connection between the accelerating periods remains unknown, and, even more
intriguing, the best dark energy candidate powering the present accelerating
stage (Lambda-vacuum) is plagued with the cosmological constant and coincidence
puzzles. Here we propose an alternative solution for such problems based on a
large class of time-dependent vacuum energy density models in the form of power
series of the Hubble rate, Lambda=Lambda(H). The proposed class of
Lambda(H)-decaying vacuum model provides: i) a new mechanism for inflation
(different from the usual inflaton models), (ii) a natural mechanism for a
graceful exit, which is universal for the whole class of models; iii) the
currently accelerated expansion of the universe, iv) a mild dynamical dark
energy at present; and v) a final de Sitter stage. Remarkably, the late-time
cosmic expansion history of our class of models is very close to the
concordance LambdaCDM model, but above all it furnishes the necessary smooth
link between the initial and final de Sitter stages through the radiation- and
matter-dominated epochs.


title:
The short-lived production of exozodiacal dust in the aftermath of a
  dynamical instability in planetary systems

abstract:
  Excess emission, associated with warm, dust belts, commonly known as
exozodis, has been observed around a third of nearby stars. The high levels of
dust required to explain the observations are not generally consistent with
steady-state evolution. A common suggestion is that the dust results from the
aftermath of a dynamical instability, an event akin to the Solar System's Late
Heavy Bombardment. In this work, we use a database of N-body simulations to
investigate the aftermath of dynamical instabilities between giant planets in
systems with outer planetesimal belts. We find that, whilst there is a
significant increase in the mass of material scattered into the inner regions
of the planetary system following an instability, this is a short-lived effect.
Using the maximum lifetime of this material, we determine that even if every
star has a planetary system that goes unstable, there is a very low probability
that we observe more than a maximum of 1% of sun-like stars in the aftermath of
an instability, and that the fraction of planetary systems currently in the
aftermath of an instability is more likely to be limited to <0.06. This
probability increases marginally for younger or higher mass stars. We conclude
that the production of warm dust in the aftermath of dynamical instabilities is
too short-lived to be the dominant source of the abundantly observed
exozodiacal dust.


title: Photocurrent in graphene harnessed by tunable intrinsic plasmons

abstract:
  Graphene's optical properties in the infrared and terahertz can be tailored
and enhanced by patterning graphene into periodic metamaterials with
sub-wavelength feature sizes. Here we demonstrate polarization sensitive and
gate tunable photodetection in graphene nanoribbon arrays. The long-lived
hybrid plasmon-phonon modes utilized are coupled excitations of electron
density oscillations and substrate (SiO2) surface polar phonons. Their
excitation by s-polarization leads to an in-resonance photocurrent an order of
magnitude larger than the photocurrent observed for p-polarization, which
excites electron-hole pairs. The plasmonic detectors exhibit photoinduced
temperature increases up to four times as large as comparable 2D graphene
detectors. Moreover, the photocurrent sign becomes polarization sensitive in
the narrowest nanoribbon arrays due to differences in decay channels for
photoexcited hybrid plasmon-phonons and electrons. Our work provides a path to
light sensitive and frequency selective photodetectors based on graphene's
plasmonic excitations.


title:
Empirical Links between XRB and AGN accretion using the complete z<0.4
  spectroscopic CSC/SDSS Catalog

abstract:
  Striking similarities have been seen between accretion signatures of Galactic
X-ray binary (XRB) systems and active galactic nuclei (AGN). XRB spectral
states show a V-shaped correlation between X-ray spectral hardness and
Eddington ratio as they vary, and some AGN samples reveal a similar trend,
implying analogous processes at vastly larger masses and timescales. To further
investigate the analogies, we have matched 617 sources from the Chandra Source
Catalog to SDSS spectroscopy, and uniformly measured both X-ray and optical
spectral characteristics across a broad range of AGN and galaxy types. We
provide useful tabulations of X-ray spectral slope for broad and narrow line
AGN, star-forming and passive galaxies and composite systems, also updating
relationships between optical (Ha and [OIII]) line emission and X-ray
luminosity. We further fit broadband spectral energy distributions with a
variety of templates to estimate bolometric luminosity. Our results confirm a
significant trend in AGN between X-ray spectral hardness and Eddington ratio
expressed in X-ray luminosity, albeit with significant dispersion. The trend is
not significant when expressed in the full bolometric or template-estimated AGN
luminosity. We also confirm a relationship between the X-ray/optical spectral
slope aox, and Eddington ratio, but it may not follow the trend predicted by
analogy with XRB accretion states.


title: Intermittency in 2D soap film turbulence

abstract:
  The Reynolds number dependency of intermittency for 2D turbulence is studied
in a flowing soap film. The Reynolds number used here is the Taylor microscale
Reynolds number R_{\lambda}, which ranges from 20 to 800. Strong intermittency
is found for both the inverse energy and direct enstrophy cascades as measured
by (a) the pdf of velocity differences P(\delta u(r)) at inertial scales r, (b)
the kurtosis of P(\partial_x u), and (c) the scaling of the so-called
intermittency exponent \mu, which is zero if intermittency is absent. Measures
(b) and (c) are quantitative, while (a) is qualitative. These measurements are
in disagreement with some previous results but not all. The velocity
derivatives are nongaussian at all R_{\lambda} but show signs of becoming
gaussian as R_{\lambda} increases beyond the largest values that could be
reached. The kurtosis of P(\delta u(r)) at various r indicates that the
intermittency is scale dependent. The structure function scaling exponents also
deviate strongly from the Kraichnan prediction. For the enstrophy cascade, the
intermittancy decreases as a power law in R_{\lambda}. This study suggests the
need for a new look at the statistics of 2D turbulence.


title: A Cabling Conjecture for Knots in Lens Spaces

abstract:
  Closed 3-string braids admit many bandings to two-bridge links. By way of the
Montesinos Trick, this allows us to construct infinite families of knots in the
connected sum of lens spaces L(r,1) # L(s,1) that admit a surgery to a lens
space for all pairs of integers (r,s) except (0,0). These knots are typically
hyperbolic. We also demonstrate that the previously known two families of
examples of hyperbolic knots in non-prime manifolds with lens space surgeries
of Eudave-Munoz--Wu and Kang all fit this construction. As such, we propose a
generalization of the Cabling Conjecture of Gonzales-Acuna--Short for knots in
lens spaces.


title:
Giant Component in Random Multipartite Graphs with Given Degree
  Sequences

abstract:
  We study the problem of the existence of a giant component in a random
multipartite graph. We consider a random multipartite graph with $p$ parts
generated according to a given degree sequence $n_i^{\mathbf{d}}(n)$ which
denotes the number of vertices in part $i$ of the multipartite graph with
degree given by the vector $\mathbf{d}$. We assume that the empirical
distribution of the degree sequence converges to a limiting probability
distribution. Under certain mild regularity assumptions, we characterize the
conditions under which, with high probability, there exists a component of
linear size. The characterization involves checking whether the
Perron-Frobenius norm of the matrix of means of a certain associated
edge-biased distribution is greater than unity. We also specify the size of the
giant component when it exists. We use the exploration process of Molloy and
Reed combined with techniques from the theory of multidimensional Galton-Watson
processes to establish this result.


title: B- and A-Type Stars in the Taurus-Auriga Star Forming Region

abstract:
  We describe the results of a search for early-type stars associated with the
Taurus-Auriga molecular cloud complex, a diffuse nearby star-forming region
noted as lacking young stars of intermediate and high mass. We investigate
several sets of possible O, B and early A spectral class members. The first is
a group of stars for which mid-infrared images show bright nebulae, all of
which can be associated with stars of spectral type B. The second group
consists of early-type stars compiled from (i) literature listings in SIMBAD;
(ii) B stars with infrared excesses selected from the Spitzer Space Telescope
survey of the Taurus cloud; (iii) magnitude- and color-selected point sources
from the 2MASS; and (iv) spectroscopically identified early-type stars from the
SDSS coverage of the Taurus region. We evaluated stars for membership in the
Taurus-Auriga star formation region based on criteria involving: spectroscopic
and parallactic distances, proper motions and radial velocities, and infrared
excesses or line emission indicative of stellar youth. For selected objects, we
also model the scattered and emitted radiation from reflection nebulosity and
compare the results with the observed spectral energy distributions to further
test the plausibility of physical association of the B stars with the Taurus
cloud. This investigation newly identifies as probable Taurus members three
B-type stars: HR 1445 (HD 28929), tau Tau (HD 29763), 72 Tau (HD 28149), and
two A-type stars: HD 31305 and HD 26212, thus doubling the number of stars A5
or earlier associated with the Taurus clouds. Several additional early-type
sources including HD 29659 and HD 283815 meet some, but not all, of the
membership criteria and therefore are plausible, though not secure, members.


title: Radio and X-ray observations of jet ejection in Cygnus X-2

abstract:
  The ejection of a relativistic jet has been observed in the luminous Galactic
low mass X-ray binary Cygnus X-2. Using high resolution radio observations, a
directly resolved ejection event has been discovered while the source was on
the Horizontal Branch of the Z-track. Contemporaneous radio and X-ray
observations were made with the European VLBI Network at 6 cm and the Swift
X-ray observatory in the 0.3 - 10 keV band. This has been difficult to achieve
because of the previous inability to predict jet formation. Two sets of ~10 hr
observations were spaced 12 hr apart, the jet apparently switching on during
Day 1. The radio results show an unresolved core evolving into an extended jet.
A preliminary value of jet velocity v/c of 0.33 +/- 0.12 was obtained,
consistent with previous determinations in Galactic sources. Simultaneous radio
and X-ray lightcurves are presented and the X-ray hardness ratio shows the
source to be on the Horizontal Branch where jets are expected. The observations
support our proposal that jet formation can in future be predicted based on
X-ray intensity increases beyond a critical value.


title:
Thermodynamics of Ferromagnetic Spin Chains in a Magnetic Field: Impact
  of the Spin-Wave Interaction

abstract:
  The thermodynamic properties of ferromagnetic spin chains have been the
subject of many publications. Still, the problem of how the spin-wave
interaction manifest itself in these low-temperature series has been neglected.
Using the method of effective Lagrangians, we explicitly evaluate the partition
function of ferromagnetic spin chains at low temperatures and in the presence
of a magnetic field up to three loops in the perturbative expansion where the
spin-wave interaction sets in. We discuss in detail the renormalization and
numerical evaluation of a particular three-loop graph and derive the
low-temperature series for the free energy density, energy density, heat
capacity, entropy density, as well as the magnetization and the susceptibility.
In the low-temperature expansion for the free energy density, the spin-wave
interaction starts manifesting itself at order $T^{5/2}$. In the pressure, the
coefficient of the $T^{5/2}$-term is positive, indicating that the spin-wave
interaction is repulsive. While it is straightforward to go up to three-loop
order in the effective loop expansion, the analogous calculation on the basis
of conventional condensed matter methods, such as spin-wave theory, appears to
be beyond reach.


title: Gravitational lensing of STU black holes

abstract:
  In this paper we study gravitational lensing by STU black holes. We
considered extremal limit of two special cases of zero-charged and one-charged
black holes, and obtain the deflection angle. We find that the black hole
charge increases the deflection angle.


title: Dynamical symmetry breaking in geometrodynamics

abstract:
  We are going to analyze through a first order perturbative formulation the
local loss of symmetry when a source of electromagnetic and gravitational field
interacts with an agent that perturbes the original geometry associated to the
source. As the symmetry in Abelian or even non-Abelian field structures in four
dimensional Lorentzian spacetimes is displayed through the existence of local
planes of symmetry that we previously called blades one and two, the loss of
symmetry will be manifested by the tilting of these planes under the influence
of the external agent. In this strict sense the original local symmetry will be
lost. But we will prove that the new blades at the same point will correspond
after the tilting generated by perturbation to a new symmetry. The point of
this note is to prove that the geometrical manifestation of local gauge
symmetries is dynamic. The local original symmetries will be lost, nonetheless
new symmetries will arise. There is a dynamic evolution of local symmetries.


title:
Robust site-resolved quantum gates in an optical lattice via
  inhomogeneous control

abstract:
  Ultracold atoms in optical lattices are an important platform for quantum
information science, lending itself naturally to quantum simulation of
many-body physics and providing a possible path towards a scalable quantum
computer. To realize its full potential, atoms at individual lattice sites must
be accessible to quantum control and measurement. This challenge has so far
been met with a combination of high-resolution microscopes and resonance
addressing that have enabled both site-resolved imaging and spin-flips. Here we
show that methods borrowed from the field of inhomogeneous control can greatly
increase the performance of resonance addressing in optical lattices, allowing
us to target arbitrary single-qubit gates on desired sites, with minimal
crosstalk to neighboring sites and greatly improved robustness against
uncertainty in the lattice position. We further demonstrate the simultaneous
implementation of different gates at adjacent sites with a single global
control waveform. Coherence is verified through two-pulse Ramsey interrogation,
and randomized benchmarking is used to measure an average gate fidelity of
~95%. Our control-based approach to reduce crosstalk and increase robustness is
broadly applicable in optical lattices irrespective of geometry, and may be
useful also on other platforms for quantum information processing, such as ion
traps and nitrogen-vacancy centers in diamond.


title: Distributed k-Means and k-Median Clustering on General Topologies

abstract:
  This paper provides new algorithms for distributed clustering for two popular
center-based objectives, k-median and k-means. These algorithms have provable
guarantees and improve communication complexity over existing approaches.
Following a classic approach in clustering by \cite{har2004coresets}, we reduce
the problem of finding a clustering with low cost to the problem of finding a
coreset of small size. We provide a distributed method for constructing a
global coreset which improves over the previous methods by reducing the
communication complexity, and which works over general communication
topologies. Experimental results on large scale data sets show that this
approach outperforms other coreset-based distributed clustering algorithms.


title:
Episodic modulations in supernova radio light curves from luminous blue
  variable supernova progenitor models

abstract:
  <Context> Ideally, one would like to know which type of core-collapse SNe is
produced by different progenitors and the channels of stellar evolution leading
to these progenitors. These links have to be very well known to use the
observed frequency of different types of SN events for probing the star
formation rate and massive star evolution in different types of galaxies.
<Aims> We investigate the link between LBV as SN progenitors and the appearance
of episodic radio light curve modulations of the SN event. <Methods> We use the
20Msun and 25Msun models with rotation at solar metallicity, part of an
extended grid of stellar models computed by the Geneva team. At their pre-SN
stage, these two models have recently been shown to have spectra similar to
those of LBV stars and possibly explode as Type IIb SNe. Based on the wind
properties before the explosion, we derive the density structure of their
circumstellar medium. This structure is used as input for computing the SN
radio light curve. <Results> We find that the 20Msun model shows radio light
curves with episodic luminosity modulations, similar to those observed in some
Type IIb SNe. This occurs because the evolution of the 20Msun model terminates
in a region of the HR diagram where radiative stellar winds present strong
density variations, caused by the bistability limit. The 25Msun model, ending
its evolution in a zone of the HR diagram where no change of the mass-loss
rates is expected, presents no such modulations in its radio SN light curve.
<Conclusions> Our results reinforce the link between SN progenitors and LBV
stars. We also confirm the existence of a physical mechanism for a single star
to have episodic radio light curve modulations. In the case of the 25Msun
progenitors, we do not obtain modulations in the radio light curve, but our
models may miss some outbursting behavior in the late stages of massive stars.


title: Exploring scalar field dynamics with Gaussian processes

abstract:
  The origin of the accelerated expansion of the Universe remains an unsolved
mystery in Cosmology. In this work we consider a spatially flat
Friedmann-Robertson-Walker (FRW) Universe with non-relativistic matter and a
single scalar field contributing to the energy density of the Universe.
Properties of this scalar field, like potential, kinetic energy, equation of
state etc. are reconstructed from Supernovae and BAO data using Gaussian
processes. We also reconstruct energy conditions and kinematic variables of
expansion, such as the jerk and the slow roll parameter. We find that the
reconstructed scalar field variables and the kinematic quantities are
consistent with a flat Lambda-CDM Universe. Further we find that the null
energy condition is satisfied for the redshift range of the Supernovae data
considered in the paper but, the strong energy condition is violated.


title:
Terahertz emission from ZnGeP2: Phase-matching, intensity and length
  scalability

abstract:
  Collinear phase-matched optical rectification is studied in ZnGeP$_{2}$
pumped with near-infrared light. The pump-intensity dependence is presented for
three crystal lengths (0.3, 1.0 and 3.0 mm) to determine the effects of linear
optical absorption, nonlinear optical absorption and terahertz free-carrier
absorption on the generation. Critical parameters such as the coherence length
(for velocity matching), dispersion length (for linear pulse broadening) and
nonlinear length (for self-phase modulation) are determined for this material.
These parameters provide insight into the upper limit of pulse intensity and
crystal length required to generate intense terahertz pulse without detriment
to the pulse shape. It is found that for 1-mm thick ZnGeP$_{2}$(012), pumped at
1.28 micron with intensity of ~15 GW/cm2 will produce intense undistorted
pulses, whereas longer crystals or larger intensities modify the pulse shape to
varying degrees. Moreover, phase-matching dispersion maps are presented for the
terahertz generation over a large tuning range (1.1-2.4 micron) in longer (3
mm) crystal, demonstrating the phase-matching bandwidth and phase mismatch that
leads to fringing associated with multi-pulse interference. All observed
results are simulated numerically showing good qualitative agreement.


title:
A far-from-CMC existence result for the constraint equations on
  manifolds with ends of cylindrical type

abstract:
  We extend the study of the vacuum Einstein constraint equations on manifolds
with ends of cylindrical type initiated by Chru\'sciel and Mazzeo by finding a
class of solutions to the fully coupled system on such manifolds. We show that
given a Yamabe positive metric g, which is conformally asymptotically
cylindrical on each end, and a 2-tensor K such that (tr K)^2 is bounded below
away from zero and asymptotically constant, then we may find an initial data
set (g',K') such that g' lies in the conformal class of g.


title: Non-Bunch-Davies Anisotropy

abstract:
  We introduce a generic mechanism that can extend the effects of relic
anisotropies at the beginning of inflation to relatively much shorter scales in
density perturbations. This is induced by non-Bunch-Davies states of the
quantum fluctuations, and can show up in the non-oscillatory components of the
density perturbations. This mechanism works for general forms of anisotropies,
and, to illustrate it, we use an example of relic vector field. The detailed
scale-dependence of these anisotropies can be used to probe the initial quantum
state of our universe.


title:
A Combined VLT and Gemini Study of the Atmosphere of the Directly-Imaged
  Planet, beta Pictoris b

abstract:
  We analyze new/archival VLT/NaCo and Gemini/NICI high-contrast imaging of the
young, self-luminous planet $\beta$ Pictoris b in seven near-to-mid IR
photometric filters, using advanced image processing methods to achieve high
signal-to-noise, high precision measurements. While $\beta$ Pic b's near-IR
colors mimick that of a standard, cloudy early-to-mid L dwarf, it is
overluminous in the mid-infrared compared to the field L/T dwarf sequence. Few
substellar/planet-mass objects -- i.e. $\kappa$ And b and 1RXJ 1609B -- match
$\beta$ Pic b's $JHK_{s}L^\prime$ photometry, and its 3.1 $\mu m$ and 5 $\mu m$
photometry are particularly difficult to reproduce. Atmosphere models adopting
cloud prescriptions and large ($\sim$ 60 $\mu m$) dust grains fail to reproduce
the $\beta$ Pic b spectrum. However, models incorporating thick clouds similar
to those found for HR 8799 bcde but also with small (a few microns) modal
particle sizes yield fits consistent with the data within uncertainties.
Assuming solar abundance models, thick clouds, and small dust particles ($<a>$
= 4 $\mu m$) we derive atmosphere parameters of log(g) = 3.8 $\pm$ 0.2 and
$T_{eff}$ = 1575--1650 $K$, an inferred mass of 7$^{+4}_{-3}$ $M_{J}$, and a
luminosity of log(L/L$_{\odot}$) $\sim$ -3.80 $\pm$ 0.02. The best-estimated
planet radius, $\approx$ 1.65 $\pm$ 0.06 $R_{J}$, is near the upper end of
allowable planet radii for hot-start models given the host star's age and
likely reflects challenges with constructing accurate atmospheric models.
Alternatively, these radii are comfortably consistent with hot-start model
predictions if $\beta$ Pic b is younger than $\approx$ 7 Myr, consistent with a
late formation, well after its host star's birth $\sim$ 12$^{+8}_{-4}$ Myr ago.


title:
The role of the Rashba coupling in spin current of monolayer gapped
  graphene

abstract:
  In the current work we have investigated the influence of the Rashba
spin-orbit coupling on spin-current of a single layer gapped graphene. It was
shown that the Rashba coupling has a considerable role in generation of the
spin-current of vertical spins in mono-layer graphene. The behavior of the
spin-current is determined by density of impurities. It was also shown that the
spin-current of the system could increase by increasing the Rashba coupling
strength and band-gap of the graphene and the sign of the spin-current could be
controlled by the direction of the current-driving electric field.


title:
Fast integral equation methods for the Laplace-Beltrami equation on the
  sphere

abstract:
  Integral equation methods for solving the Laplace-Beltrami equation on the
unit sphere in the presence of multiple "islands" are presented. The surface of
the sphere is first mapped to a multiply-connected region in the complex plane
via a stereographic projection. After discretizing the integral equation, the
resulting dense linear system is solved iteratively using the fast multipole
method for the 2D Coulomb potential in order to calculate the matrix-vector
products. This numerical scheme requires only O(N) operations, where $N$ is the
number of nodes in the discretization of the boundary. The performance of the
method is demonstrated on several examples.


title: Optically Mediated Hybridization Between Two Mechanical Modes

abstract:
  In this paper we study a system consisting of two nearly degenerate
mechanical modes that couple to a single mode of an optical cavity. We show
that this coupling leads to nearly complete (99.5%) hybridization of the two
mechanical modes into a bright mode that experiences strong optomechanical
interactions and a dark mode that experiences almost no optomechanical
interactions. We use this hybridization to transfer energy between the
mechanical modes with 40% efficiency.


title: Multiple time scale blinking in InAs quantum dot single-photon sources

abstract:
  We use photon correlation measurements to study blinking in single,
epitaxially-grown self-assembled InAs quantum dots situated in circular Bragg
grating and microdisk cavities. The normalized second-order correlation
function g(2)(\tau) is studied across eleven orders of magnitude in time, and
shows signatures of blinking over timescales ranging from tens of nanoseconds
to tens of milliseconds. The g(2)(\tau) data is fit to a multi-level system
rate equation model that includes multiple non-radiating (dark) states, from
which radiative quantum yields significantly less than 1 are obtained. This
behavior is observed even in situations for which a direct histogramming
analysis of the emission time-trace data produces inconclusive results.


title: Orthogonal Range Searching for Text Indexing

abstract:
  Text indexing, the problem in which one desires to preprocess a (usually
large) text for future (shorter) queries, has been researched ever since the
suffix tree was invented in the early 70's. With textual data continuing to
increase and with changes in the way it is accessed, new data structures and
new algorithmic methods are continuously required. Therefore, text indexing is
of utmost importance and is a very active research domain.
  Orthogonal range searching, classically associated with the computational
geometry community, is one of the tools that has increasingly become important
for various text indexing applications. Initially, in the mid 90's there were a
couple of results recognizing this connection. In the last few years we have
seen an increase in use of this method and are reaching a deeper understanding
of the range searching uses for text indexing.
  In this monograph we survey some of these results.


title: Asymptotic enumeration of magic series

abstract:
  A magic series is a set of natural numbers that, by virtue of its size, sum,
and maximum value, could fill a row of a normal magic square. In this paper, we
derive an exact two-dimensional integral representation for the number of magic
series of order N. By applying the stationary phase approximation, we develop
an expansion in powers of 1/N for the number of magic series and calculate the
first few terms. We find excellent agreement between our approximation and the
known exact values. Related results are presented for magic cube and hypercube
series, bimagic series, and trimagic series.


title:
Relation of exact Gaussian basis methods to the dephasing
  representation: Theory and application to time-resolved electronic spectra

abstract:
  We recently showed that the Dephasing Representation (DR) provides an
efficient tool for computing ultrafast electronic spectra and that further
acceleration is possible with cellularization [M. \v{S}ulc and J.
Van\'i\v{c}ek, Mol. Phys. 110, 945 (2012)]. Here we focus on increasing the
accuracy of this approximation by first implementing an exact Gaussian basis
method, which benefits from the accuracy of quantum dynamics and efficiency of
classical dynamics. Starting from this exact method, the DR is derived together
with ten other methods for computing time-resolved spectra with intermediate
accuracy and efficiency. These methods include the Gaussian DR, an exact
generalization of the DR, in which trajectories are replaced by communicating
frozen Gaussian basis functions evolving classically with an average
Hamiltonian. The newly obtained methods are tested numerically on time
correlation functions and time-resolved stimulated emission spectra in the
harmonic potential, pyrazine S0/S1 model, and quartic oscillator. Numerical
results confirm that both the Gaussian basis method and the Gaussian DR
increase the accuracy of the DR. Surprisingly, in chaotic systems the Gaussian
DR can outperform the presumably more accurate Gaussian basis method, in which
the two bases are evolved separately.


title: Prediction with Missing Data via Bayesian Additive Regression Trees

abstract:
  We present a method for incorporating missing data in non-parametric
statistical learning without the need for imputation. We focus on a tree-based
method, Bayesian Additive Regression Trees (BART), enhanced with "Missingness
Incorporated in Attributes," an approach recently proposed incorporating
missingness into decision trees (Twala, 2008). This procedure takes advantage
of the partitioning mechanisms found in tree-based models. Simulations on
generated models and real data indicate that our proposed method can forecast
well on complicated missing-at-random and not-missing-at-random models as well
as models where missingness itself influences the response. Our procedure has
higher predictive performance and is more stable than competitors in many
cases. We also illustrate BART's abilities to incorporate missingness into
uncertainty intervals and to detect the influence of missingness on the model
fit.


title:
Direct Measurement of a 27-Dimensional Orbital-Angular-Momentum State
  Vector

abstract:
  The measurement of a quantum state poses a unique challenge for
experimentalists. Recently, the technique of "direct measurement" was proposed
for characterizing a quantum state in-situ through sequential weak and strong
measurements. While this method has been used for measuring polarization
states, its real potential lies in the measurement of states with a large
dimensionality. Here we show the practical direct measurement of a
high-dimensional state vector in the discrete basis of orbital-angular
momentum. Through weak measurements of orbital-angular momentum and strong
measurements of angular position, we measure the complex probability amplitudes
of a pure state with a dimensionality, d=27. Further, we use our method to
directly observe the relationship between rotations of a state vector and the
relative phase between its orbital-angular-momentum components. Our technique
has important applications in high-dimensional classical and quantum
information systems, and can be extended to characterize other types of large
quantum states.


title:
Quasiparticle band-edge energy and band offsets of monolayer of
  molybdenum and tungsten chalcogenide

abstract:
  We report the quasiparticle energy of monolayer of molybdenum and tungsten
dichalcogenides, MX2 (M=Mo, W; X=S, Se, Te). Beyond calculating bandgaps, we
have achieved converged absolute band energies relative to the vacuum level.
Compared with the results from other approaches, the GW calculation reveals
substantially larger bandgaps and different absolute band energies because of
enhanced many-electron effects. Interestingly, our fully-converged
quasiparticle energies ratify the band-gap-center approximation, making it a
convenient way to estimate quasiparticle energy. The absolute quasiparticle
energies and band offsets obtained in this work are important for designing
heterojunction devices and chemical catalysts based on monolayer
dichalcogenides.


title: A first-principles linear response description of the spin Nernst effect

abstract:
  A first-principles description of the spin Nernst effect, denoting the
occurrence of a transverse spin current due to a temperature gradient, is
presented. The approach, based on an extension to the Kubo-Streda equation for
spin transport, supplies in particular the formal basis for investigations of
diluted as well as concentrated alloys. Results for corresponding applications
to the alloy system Au-Cu give the intrinsic and extrinsic contributions to the
relevant transport coefficients. Using scaling laws allows in addition to split
the extrinsic contribution into its skew scattering and side-jump parts.


title: Black holes and the butterfly effect

abstract:
  We use holography to study sensitive dependence on initial conditions in
strongly coupled field theories. Specifically, we mildly perturb a thermofield
double state by adding a small number of quanta on one side. If these quanta
are released a scrambling time in the past, they destroy the local two-sided
correlations present in the unperturbed state. The corresponding bulk geometry
is a two-sided AdS black hole, and the key effect is the blueshift of the early
infalling quanta relative to the $t = 0$ slice, creating a shock wave. We
comment on string- and Planck-scale corrections to this setup, and discuss
points that may be relevant to the firewall controversy.


title: Rank-Extreme Association of Gaussian Vectors and Low-Rank Detection

abstract:
  We study the spherical cap packing problem with a probabilistic approach.
Such probabilistic considerations result in an asymptotic sharp universal
uniform bound on the maximal inner product between any set of unit vectors and
a stochastically independent uniformly distributed unit vector. When the set of
unit vectors are themselves independently uniformly distributed, we further
develop the extreme value distribution limit of the maximal inner product,
which characterizes its uncertainty around the bound. As applications of the
above asymptotic results, we derive (1) an asymptotic sharp universal uniform
bound on the maximal spurious correlation, as well as its uniform convergence
in distribution when the explanatory variables are independently Gaussian
distributed; and (2) an asymptotic sharp universal bound on the maximum norm of
a low-rank elliptically distributed vector, as well as related limiting
distributions. With these results, we develop a fast detection method for a
low-rank structure in high-dimensional Gaussian data without using the spectrum
information.


title: HATS-3b: An inflated hot Jupiter transiting an F-type star

abstract:
  We report the discovery by the HATSouth survey of HATS-3b, a transiting
extrasolar planet orbiting a V=12.4 F-dwarf star. HATS-3b has a period of P =
3.5479d, mass of Mp = 1.07MJ, and radius of Rp = 1.38RJ. Given the radius of
the planet, the brightness of the host star, and the stellar rotational
velocity (vsini = 9.0km/s), this system will make an interesting target for
future observations to measure the Rossiter-McLaughlin effect and determine its
spin-orbit alignment. We detail the low/medium-resolution reconnaissance
spectroscopy that we are now using to deal with large numbers of transiting
planet candidates produced by the HATSouth survey. We show that this important
step in discovering planets produces logg and Teff parameters at a precision
suitable for efficient candidate vetting, as well as efficiently identifying
stellar mass eclipsing binaries with radial velocity semi-amplitudes as low as
1 km/s.


title:
Entropy and a convergence theorem for Gauss curvature flow in high
  dimension

abstract:
  In this paper we prove uniform regularity estimates for the normalized Gauss
curvature flow in higher dimensions. The convergence of solutions in
$C^\infty$-topology to a smooth strictly convex soliton as $t$ approaches to
infinity is obtained as a consequence of these estimates together with an
earlier result of Andrews. The estimates are established via the study of a new
entropy functional for the flow.


title: Provable Inductive Matrix Completion

abstract:
  Consider a movie recommendation system where apart from the ratings
information, side information such as user's age or movie's genre is also
available. Unlike standard matrix completion, in this setting one should be
able to predict inductively on new users/movies. In this paper, we study the
problem of inductive matrix completion in the exact recovery setting. That is,
we assume that the ratings matrix is generated by applying feature vectors to a
low-rank matrix and the goal is to recover back the underlying matrix.
Furthermore, we generalize the problem to that of low-rank matrix estimation
using rank-1 measurements. We study this generic problem and provide conditions
that the set of measurements should satisfy so that the alternating
minimization method (which otherwise is a non-convex method with no convergence
guarantees) is able to recover back the {\em exact} underlying low-rank matrix.
  In addition to inductive matrix completion, we show that two other low-rank
estimation problems can be studied in our framework: a) general low-rank matrix
sensing using rank-1 measurements, and b) multi-label regression with missing
labels. For both the problems, we provide novel and interesting bounds on the
number of measurements required by alternating minimization to provably
converges to the {\em exact} low-rank matrix. In particular, our analysis for
the general low rank matrix sensing problem significantly improves the required
storage and computational cost than that required by the RIP-based matrix
sensing methods \cite{RechtFP2007}. Finally, we provide empirical validation of
our approach and demonstrate that alternating minimization is able to recover
the true matrix for the above mentioned problems using a small number of
measurements.


title: High Order Three Part Split Symplectic Integration Schemes

abstract:
  Symplectic integration methods based on operator splitting are well
established in many branches of science. For Hamiltonian systems which split in
more than two parts, symplectic methods of higher order have been studied in
detail only for a few special cases. In this work, we present and compare
different ways to construct high order symplectic schemes for general
Hamiltonian systems that can be split in three integrable parts. We use these
techniques to numerically solve the equations of motion for a simple toy model,
as well as the disordered discrete nonlinear Schr\"odinger equation. We thereby
compare the efficiency of symplectic and non-symplectic integration methods.
Our results show that the new symplectic schemes are superior to the other
tested methods, with respect to both long term energy conservation and
computational time requirements.


title: Dark matter cavity and amplification of gravitational waves

abstract:
  The linearized Einstein theory in the approximately flat time-space is
modified accounting for a massive graviton as a dark matter in the universe. On
the basis of magnetic-type Maxwell- Proca -Vlasov equations, the interactions
of the gravitoelectromagnetic fields (GEM), involving the vector potential,
with gravitons (dark matter) dealing with resonant wave-particle and wave-wave
one are studied. It is found that the behavior of the perturbed GEM fields and
the perturbed matter density can be described by the nonlinear coupling
Eqs.(4.6) and(4.7). It is shown that the perturbed field is instable with
respect to the collapse, leading to enhancement of the GE field. In other
words, the gravitational waves (GWs) are amplified and concurrently the cluster
and cavity of the dark matter formed. And it is referred that the lower limit
for graviton mass is $M_{gr}^\geqslant 10^{- 50}(g)$ by the condition to exist
stable longitudinal mode.


title: Quantum field theory with varying couplings

abstract:
  A quantum scalar field theory with spacetime-dependent coupling is studied.
Surprisingly, while translation invariance is explicitly broken in the
classical theory, momentum conservation is recovered at the quantum level for
some specific choice of the coupling's profile for any finite-order
perturbative expansion. For one of these cases, some tree and one-loop diagrams
are calculated. This is an example of a theory where violation of Lorentz
symmetry is not enhanced at the quantum level. We draw some consequences for
the renormalization properties of certain classes of fractional field theories.


title:
Composition limits and separating examples for some Boolean function
  complexity measures

abstract:
  Block sensitivity ($bs(f)$), certificate complexity ($C(f)$) and fractional
certificate complexity ($C^*(f)$) are three fundamental combinatorial measures
of complexity of a boolean function $f$. It has long been known that $bs(f)
\leq C^{\ast}(f) \leq C(f) =O(bs(f)^2)$. We provide an infinite family of
examples for which $C(f)$ grows quadratically in $C^{\ast}(f)$ (and also
$bs(f)$) giving optimal separations between these measures. Previously the
biggest separation known was $C(f)=C^{\ast}(f)^{\log_{4.5}5}$. We also give a
family of examples for which $C^{\ast}(f)=\Omega(bs(f)^{3/2})$.
  These examples are obtained by composing boolean functions in various ways.
Here the composition $f \circ g$ of $f$ with $g$ is obtained by substituting
for each variable of $f$ a copy of $g$ on disjoint sets of variables. To
construct and analyse these examples we systematically investigate the
behaviour under function composition of these measures and also the sensitivity
measure $s(f)$. The measures $s(f)$, $C(f)$ and $C^{\ast}(f)$ behave nicely
under composition: they are submultiplicative (where measure $m$ is
submultiplicative if $m(f \circ g) \leq m(f)m(g)$) with equality holding under
some fairly general conditions. The measure $bs(f)$ is qualitatively different:
it is not submultiplicative. This qualitative difference was not noticed in the
previous literature and we correct some errors that appeared in previous
papers. We define the composition limit of a measure $m$ at function $f$,
$m^{\lim}(f)$ to be the limit as $k$ grows of $m(f^{(k)})^{1/k}$, where
$f^{(k)}$ is the iterated composition of $f$ with itself $k$-times. For any
function $f$ we show that $bs^{\lim}(f) = (C^*)^{\lim}(f)$ and characterize
$s^{\lim}(f), (C^*)^{\lim}(f)$, and $C^{\lim}(f)$ in terms of the largest
eigenvalue of a certain set of $2\times 2$ matrices associated with $f$.


title:
Error control of a numerical formula for the Fourier transform by
  Ooura's continuous Euler transform and fractional FFT

abstract:
  In this paper, we consider a method for fast numerical computation of the
Fourier transform of a slowly decaying function with given accuracy in given
ranges of the frequency. In these decades, some useful formulas for the Fourier
transform are proposed to recover difficulty of the computation due to the slow
decay and the oscillation of the integrand. In particular, Ooura proposed
formulas with continuous Euler transformation and showed their effectiveness.
It is, however, also reported that errors of them become large outside some
ranges of the frequency. Then, for an illustrating representative of the
formulas, we choose parameters in the formula based on its error analysis to
compute the Fourier transform with given accuracy in given ranges of the
frequency. Furthermore, combining the formula and fractional FFT, a
generalization of the fast Fourier transform (FFT), we execute the computation
in the same order of computation time as the FFT.


title: Beurling Spectra of Functions on Locally Compact Abelian Groups

abstract:
  Let $G$ be a locally compact abelian topological group. For locally bounded
measurable functions $\varphi: G\to\Bbb {C}$ we discuss notions of spectra for
$\varphi$ relative to subalgebras of $L^{1}(G)$. In particular we study
polynomials on $G$ and determine their spectra. We also characterize the
primary ideals of certain Beurling algebras $L_{w}^{1}(\Bbb Z)$ on the group of
integers $\Bbb Z$. This allows us to classify those elements of $L_{w}^{1}(G)$
that have finite spectrum. If $\varphi$ is a uniformly continuous function
whose differences are bounded, there is a Beurling algebra naturally associated
with $\varphi$. We give a condition on the spectrum of $\varphi$ relative to
this algebra which ensures that $\varphi$ is bounded. Finally we give spectral
conditions on a bounded function on $\Bbb R$ that ensure that its indefinite
integral is bounded.


title:
Dominance of eclipsed ferrocene conformer in solutions revealed by the
  IR fingerprint spectral splitting

abstract:
  A combined high-resolution Fourier transform infrared (FTIR) spectra of
ferrocene (Fc) and density functional theory (DFT) based quantum mechanical
calculations confirmed the dominance of the eclipsed Fc conformer in the
fingerprint region of 400-500 cm-1. The IR spectra of Fc were measured in
solutions with a number of non-polar solvents such as acetonitrile,
dichloromethane, tetrahydrofuran and dioxane. The measurements agree well with
the earlier IR spectra of Lippincott and Nelson (1958) as well as the most
recent IR spectral measurement in dichloromethane solution of Duhovic and
Diaconescu (2013). All experimental measurements in the solutions unambiguously
exhibit an IR spectral splitting of ca. 15 cm-1 in the 480-500 cm-1 region. The
DFT based B3LYP/m6-31G(d) quantum mechanical calculations using implicit
solvent models in this study indicates that only the ground electronic state of
the eclipsed (D5h) Fc splits in the IR fingerprint region of ca. 500 cm-1. The
IR spectral splitting characterises the centre Fe metal related vibrations of
the eclipsed Fc, in agreement with our previous finding in gas phase [Mohammadi
et al, 2012]. The present study further suggests that the effects of solvents
on the IR spectra of Fc in this region are small and the solvent model effects
are also small but the solute molecular density (SMD) model seems to produce
the most accurate IR spectrum in the region of 400-600 cm-1 of Fc without
scaling the calculated results.


title: The smallest one-realization of a given set IV

abstract:
  Let $S$ be a finite set of positive integers. A mixed hypergraph ${\cal H}$
is a one-realization of $S$ if its feasible set is $S$ and each entry of its
chromatic spectrum is either 0 or 1. In [P. Zhao, K. Diao, Y. Chang and K.
Wang, The smallest one-realization of a given set
\uppercase\expandafter{\romannumeral2}, Discrete Math. 312 (2012) 2946--2951],
we determined the minimum number of vertices of a 3-uniform bi-hypergraph which
is a one-realization of $S$. In this paper, we generalize this result to
$r$-uniform bi-hypergraphs.


title: The Geometry of Light Paths for Equiangular Spirals

abstract:
  First geometric calculus alongside its description of equiangular spirals,
reflections and rotations is introduced briefly. Then single and double
reflections at such a spiral are investigated. It proves suitable to
distinguish incidence from the \textit{right} and \textit{left} relative to the
radial direction. The properties of geometric light propagation inside the
equiangular spiral are discussed, as well as escape conditions and
characteristics. Finally the dependence of right and left incidence from the
source locations are examined, revealing a well defined inner \textit{critical}
curve, which delimits the area of purely right incident propagation. This
critical curve is self similar to the original equiangular spiral.


title:
Error Estimates of Runge-Kutta Discontinuous Galerkin Methods for the
  Vlasov-Maxwell System

abstract:
  In this paper, error analysis is established for Runge-Kutta discontinuous
Galerkin (RKDG) methods to solve the Vlasov-Maxwell system. This nonlinear
hyperbolic system describes the time evolution of collisionless plasma
particles of a single species under the self-consistent electromagnetic field,
and it models many phenomena in both laboratory and astrophysical plasmas. The
methods involve a third order TVD Runge-Kutta discretization in time and upwind
discontinuous Galerkin discretizations of arbitrary order in phase domain. With
the assumption that the exact solution has sufficient regularity, the $L^2$
errors of the particle number density function as well as electric and magnetic
fields at any given time $T$ are bounded by $C h^{k+\frac{1}{2}}+C\tau^3$ under
a CFL condition $\tau /h \leq \gamma$. Here $k$ is the polynomial degree used
in phase space discretization, satisfying $k \geq \left \lceil \frac{d_x +
1}{2} \right \rceil$ (the smallest integer greater than or equal to
$\frac{d_x+1}{2}$, with $d_x$ being the dimension of spatial domain), $\tau$ is
the time step, and $h$ is the maximum mesh size in phase space. Both $C$ and
$\gamma$ are positive constants independent of $h$ and $\tau$, and they may
depend on the polynomial degree $k$, time $T$, the size of the phase domain,
certain mesh parameters, and some Sobolev norms of the exact solution. The
analysis can be extended to RKDG methods with other numerical fluxes and to
RKDG methods solving relativistic Vlasov-Maxwell equations.


title:
Everything SAXS: Small-angle scattering pattern collection and
  correction

abstract:
  For obtaining reliable nanostructural details of large amounts of sample ---
and if it is applicable --- Small-Angle Scattering (SAS) is a prime technique
to use. It promises to obtain bulk-scale, statistically sound information on
the morphological details of the nanostructure, and has thus led to many a
researcher investing their time in it over the last eight decades of
development. Due to pressure both from scientists requesting more details on
increasingly complex nanostructures, as well as the ever improving
instrumentation leaving less margin for ambiguity, small-angle scattering
methodologies have been evolving at a high pace over the last few decades.
  As the quality of any results can only be as good as the data that goes into
these methodologies, the improvements in data collection and all imaginable
data correction steps are reviewed here. This work is intended to provide a
comprehensive overview of all data corrections, to aid the small-angle
scatterer to decide which are relevant for their measurement and how these
corrections are performed. Clear mathematical descriptions of the corrections
are provided where feasible. Furthermore, as no quality data exists without a
decent estimate of its precision, the error estimation and propagation through
all these steps is provided alongside the corrections. With these data
corrections, the collected small-angle scattering pattern can be made of the
highest standard allowing for authoritative nanostructural characterisation
through its analysis. A brief background of small-angle scattering, the
instrumentation developments over the years, and pitfalls that may be
encountered upon data interpretations are provided as well.


title: Newton-Cartan Geometry and the Quantum Hall Effect

abstract:
  We construct an effective field theory for quantum Hall states, guided by the
requirements of nonrelativistic general coordinate invariance and regularity of
the zero mass limit. We propose Newton-Cartan geometry as the most natural
formalism to construct such a theory. Universal predictions of the theory are
discussed.


title: Emergence of space and cosmic evolution based on entropic force

abstract:
  In this paper, we propose a model in which an additional pressure due to the
effects of the entropic force is added to the ideal fluid. Furthermore, we
obtain the dynamic equation in the FRW universe which contains the quantum
gravitational effects based on the description of entropic force and emergence
of space. Our model can well explain the age of the universe and the effect of
the current accelerating expansion. We give the relation between the luminosity
distance and the redshift factor, and compare this relation with that of lambda
cold dark matter model($\Lambda CDM$ model).


title:
A Statistical Study on the Low-Frequency QPO Amplitude Spectrum and
  Amplitude in GRS 1915+105

abstract:
  A statistical study was made on both the energy dependence of the
low-frequency quasi-periodic oscillation (QPO) amplitude (LFQPO amplitude
spectrum) and the LFQPO amplitude from all the RXTE observations of GRS
1915+105. Based on the two-branch correlation of the LFQPO frequency and the
hardness ratio, the observations that were suitable for evaluating the LFQPO
amplitude spectrum were divided into two groups. According to a comparison
between the radio and X-ray emissions, we deduced that the jets during the two
groups of observations are very different. A negative correlation between the
LFQPO frequency and the radio flux was found for one group. The LFQPO amplitude
spectrum was fitted by a power-law with an exponential cutoff in order to
describe it quantitatively. It reveals that as the LFQPO frequency increases,
the power-law hardens. And the cutoff energy firstly decreases, and then
smoothly levels off. The fit also shows that the LFQPO amplitude spectra of the
two groups are essentially the same, suggesting that the LFQPO seems not to
originate from the jet. The LFQPO amplitude spectra are hard, indicating a
possible origin of the LFQPO in the corona. As the LFQPO frequency increases,
the LFQPO amplitude firstly increases and then decreases. The effects of the
low pass filter and the jet on the LFQPO amplitude are discussed.


title:
Detection of shorter-than-skin-depth acoustic pulses in a metal film via
  transient reflectivity

abstract:
  The detection of ultrashort laser-generated acoustic pulses at a metal
surface and the reconstruction of the acoustic strain profile are investigated.
A 2 ps-long acoustic pulse generated in an SrRuO$_{3}$ layer propagates through
an adjacent gold layer and is detected at its surface by a reflected probe
pulse. We show that the intricate shape of the transient reflectivity waveform
and the ability to resolve acoustic pulses shorter than the optical skin depth
are controlled by a single parameter, which is determined by the ratio of the
real and imaginary parts of the photoelastic constant of the material. We also
demonstrate a Fourier transform-based algorithm that can be used to extract
acoustic strain profiles from transient reflectivity measurements.


title:
Dephasing-assisted parameter estimation in the presence of dynamical
  decoupling

abstract:
  We study the dephasing-assisted precision of parameter estimation (PPE)
enhancement in atom interferometer under dynamical decoupling (DD) pulses.
Through calculating spin squeezing (SS) and quantum Fisher information (QFI),
we find that dephasing noise can improve PPE by inducing SS, and the DD pulses
can maximize the improvement. It is indicated that in the presence of DD
pulses, the dephasing-induced SS can reach the limit of \textquotedblleft
one-axis twisting\textquotedblright\ model, $\xi^2\simeq N^{-2/3}$ with $\xi^2$
being the SS parameter and N the number of atoms. In particular, we find that
the DD pulses can amplify the dephasing-induced QFI by a factor of $\simeq N/2$
compared with the noise-free case, which means that under the control of DD
pulses, the dephasing noise can enhance the PPE to the scale of $\sqrt{2}/N$,
the same order of magnitude of Heisenberg limit (1/N).


title:
Detection of a luminous hot X-ray corona around the massive spiral
  galaxy NGC266

abstract:
  The presence of luminous hot X-ray coronae in the dark matter halos of
massive spiral galaxies is a basic prediction of galaxy formation models.
However, observational evidence for such coronae is very scarce, with the first
few examples having only been detected recently. In this paper, we study the
large-scale diffuse X-ray emission associated with the massive spiral galaxy
NGC266. Using ROSAT and Chandra X-ray observations we argue that the diffuse
emission extends to at least ~70 kpc, whereas the bulk of the stellar light is
confined to within ~25 kpc. Based on X-ray hardness ratios, we find that most
of the diffuse emission is released at energies <1.2 keV, which indicates that
this emission originates from hot X-ray gas. Adopting a realistic gas
temperature and metallicity, we derive that in the (0.05-0.15)r_200 region
(where r_200 is the virial radius) the bolometric X-ray luminosity of the hot
gas is (4.3 +/- 0.8) x 10^40 erg/s and the gas mass is (9.1 +/- 0.9) x 10^9
M_sun. These values are comparable to those observed for the two other
well-studied X-ray coronae in spiral galaxies, suggesting that the physical
properties of such coronae are similar. This detection offers an excellent
opportunity for comparison of observations with detailed galaxy formation
simulations.


title:
A Spectroscopic Analysis of the Eclipsing Short-Period Binary v505 Per
  and the Origin of the Lithium Dip

abstract:
  As a test of rotationally-induced mixing causing the well-known Li dip in
older mid-F dwarfs in the local Galactic disk, we utilize high-resolution and
-S/N Keck/HIRESspectroscopy to measure the Li abundance in the components of
the1 Gyr, [Fe/H]=-0.15 eclipsing short-period binary V505 Per. We find
A(Li)=2.7+/-0.1 and 2.4+/-0.2 in the Teff=6500 and 6450 K primary and secondary
components, respectively. Previous Teff determinations and uncertainties
suggest that each component is located in the midst of the Li dip. If so, their
A(Li) are >=2-5 times larger than A(Li) detections and upper limits observed in
the similar metallicity and intermediate-age open clusters NGC 752 and 3680, as
well as the more metal-rich and younger Hyades and Praesepe. These differences
are even larger if the consistent estimates of the scaling ofinitial Li with
metallicity inferred from nearby disk stars, open clusters, and recent Galactic
chemical evolution models are correct. Our results suggest, independently of
complementary evidence based on Li/Be ratios, Be/B ratios, and Li in subgiants
evolving out of the Li dip, that main-sequence angular momentum evolution is
the origin of the Li dip. Specifically, our stars' A(Li) indicates tidal
synchronization can be sufficiently efficient and occur early enough in
short-period binary mid-F stars to reduce the effects of rotationally-induced
mixing and destruction of Li occuring during the main-sequence in otherwise
similar stars that are not short-period tidally-locked binaries.


title:
Fully-Coupled Simulation of Cosmic Reionization. I: Numerical Methods
  and Tests

abstract:
  We describe an extension of the Enzo code to enable fully-coupled radiation
hydrodynamical simulation of inhomogeneous reionization in large $\sim (100
Mpc)^3$ cosmological volumes with thousands to millions of point sources. We
solve all dynamical, radiative transfer, thermal, and ionization processes
self-consistently on the same mesh, as opposed to a postprocessing approach
which coarse-grains the radiative transfer. We do, however, employ a simple
subgrid model for star formation which we calibrate to observations. Radiation
transport is done in the grey flux-limited diffusion (FLD) approximation, which
is solved by implicit time integration split off from the gas energy and
ionization equations, which are solved separately. This results in a faster and
more robust scheme for cosmological applications compared to the earlier
method. The FLD equation is solved using the hypre optimally scalable geometric
multigrid solver from LLNL. By treating the ionizing radiation as a grid field
as opposed to rays, our method is scalable with respect to the number of
ionizing sources, limited only by the parallel scaling properties of the
radiation solver. We test the speed and accuracy of our approach on a number of
standard verification and validation tests. We show by direct comparison with
Enzo's adaptive ray tracing method Moray that the well-known inability of FLD
to cast a shadow behind opaque clouds has a minor effect on the evolution of
ionized volume and mass fractions in a reionization simulation validation test.
We illustrate an application of our method to the problem of inhomogeneous
reionization in a 80 Mpc comoving box resolved with $3200^3$ Eulerian grid
cells and dark matter particles.


title: Information sharing and sorting in a community

abstract:
  We present the results of detailed numerical study of a model for the sharing
and sorting of informations in a community consisting of a large number of
agents. The information gathering takes place in a sequence of mutual bipartite
interactions where randomly selected pairs of agents communicate with each
other to enhance their knowledge and sort out the common information. Though
our model is less restricted compared to the well established naming game, yet
the numerical results strongly indicate that the whole set of exponents
characterizing this model are different from those of the naming game and they
assume non-trivial values. Finally it appears that in analogy to the emergence
of clusters in the phenomenon of percolation, one can define clusters of agents
here having the same information. We have studied in detail the growth of the
largest cluster in this article and performed its finite-size scaling analysis.


title: No consistent bimetric gravity?

abstract:
  We discuss the prospects for a consistent, nonlinear, partially massless
(PM), gauge symmetry of bimetric gravity (BMG). Just as for single metric
massive gravity, we show that consistency of BMG relies on it having a PM
extension; we then argue that it cannot.


title:
The reltation between the electronic structure and thermoelectric
  transport properties for Zintl compounds M2Zn5As4 (M=K, Rb)

abstract:
  The electronic structure and thermoelectric properties of are studied by the
first principles and the semiclassical BoltzTrap theory.


title: Estimating the distance from testable affine-invariant properties

abstract:
  Let $\cal{P}$ be an affine invariant property of functions $\mathbb{F}_p^n
\to [R]$ for fixed $p$ and $R$. We show that if $\cal{P}$ is locally testable
with a constant number of queries, then one can estimate the distance of a
function $f$ from $\cal{P}$ with a constant number of queries. This was
previously unknown even for simple properties such as cubic polynomials over
$\mathbb{F}_2$.
  Our test is simple: take a restriction of $f$ to a constant dimensional
affine subspace, and measure its distance from $\cal{P}$. We show that by
choosing the dimension large enough, this approximates with high probability
the global distance of $f$ from $\cP$. The analysis combines the approach of
Fischer and Newman [SIAM J. Comp 2007] who established a similar result for
graph properties, with recently developed tools in higher order Fourier
analysis, in particular those developed in Bhattacharyya et al. [STOC 2013].


title: An Empirical Model for the Star Formation History in Dark Matter Halos

abstract:
  We develop an empirical approach to infer the star formation rate in dark
matter halos from the galaxy stellar mass function (SMF) at different redshifts
and the local cluster galaxy luminosity function (CGLF), which has a steeper
faint end relative to the SMF of local galaxies. As satellites are typically
old galaxies which have been accreted earlier, this feature can cast important
constraint on the formation of low-mass galaxies at high-redshift. The
evolution of the SMFs suggests the star formation in high mass halos
($>10^{12}M_{\odot}h^{-1}$) has to be boosted at high redshift beyond what is
expected from a simple scaling of the dynamical time. The faint end of the CGLF
implies a characteristic redshift $z_c\approx2$ above which the star formation
rate in low mass halos with masses $< 10^{11}M_{\odot}h^{-1}$ must be enhanced
relative to that at lower z. This is not directly expected from the standard
stellar feedback models. Also, this enhancement leads to some interesting
predictions, for instance, a significant old stellar population in present-day
dwarf galaxies with $M_* < 10^8 M_{\odot}h^{-2}$ and steep slopes of high
redshift stellar mass and star formation rate functions.


title: Meteors in the Maori Astronomical Traditions of New Zealand

abstract:
  We review the literature for perceptions of meteors in the Maori cultures of
New Zealand. We examine representations of meteors in religion, story, and
ceremony. We find that meteors are sometimes personified as gods or children,
or are seen as omens of death and destruction. The stories we found highlight
the broad perception of meteors found throughout the Maori culture and
demonstrate that some early scholars conflated the terms comet and meteor.


title: Majorana bound states in d-wave superconductor-based hybrid systems

abstract:
  For the search of Majorana fermions, we propose to employ a ramp-type
Josephson edge junction between a normal metal such as Au, Ag or alloys of
heavy metals and a topologically-trivial dx2-y2 wave high-Tc superconductor
YBa2Cu3O7. The success in forming the elusive zero-energy Majorana bound states
(MBS) at the junction relies crucially upon the strength of the Rashba
spin-orbit coupling (RSOC) at the metal/superconductor interface, the tunneling
direction, and the interface quality which includes a near zero tunnel barrier
height. When these junction conditions are collectively satisfied, definitive
signatures of Majorana fermions will emerge. After inspecting a vast amount of
published data of junctions that are close to what we have proposed, we were
able to find: 1) angular resonant Andreev reflection, and 2) quantized zero
bias normalized differential conductance peak (ZBCP), as possible evidence for
MBS formed at the junction interface. Encouraged by these findings, we have
designed a MBS-supporting d-wave superconductor based pi-loop heterostructure
as a qubit platform. Such pi-loops are characterized by a doubly degenerate
half flux quantum vortex (HQV) and are topologically protected by a parity
effect arising from an odd number of sign changes of the supercurrent
circulating in the loop. The topological protection is further enhanced by the
formation of RSOC induced Majorana bound states at the Josephson junction
interface. The proposed MBS-plus-HQV qubit platform will be useful for
demonstrating non-Abelian exchange statistics and for building a prototype
topological quantum computer.


title: Dynamic susceptibility and dynamic correlations in spin ice

abstract:
  Here we calculate the dynamic susceptibility and dynamic correlation function
in spin ice using the model of emergent magnetic monopoles. Calculations are
based on a method originally suggested for the description of dynamic processes
in water ice (non-equilibrium thermodynamics approach). We show that for zero
temperature the dynamic correlation function reproduces the transverse dipole
correlations (static correlation function) characteristic of spin ice in its
ground state. At non-zero temperatures the dynamic correlation function
includes an additional longitudinal component which decreases as the
temperature decreases. Both terms (transverse and longitudinal) exhibit
identical Debye-like dependences on frequency but with different relaxation
times: the magnetic Coulomb interaction of monopoles reduces the longitudinal
relaxation time with respect to the transverse one. We calculate the dielectric
function for the magnetic monopole gas and discuss how the non-equilibrium
thermodynamics approach exposes corrections to the Debye-Huckel theory of
magnetic monopoles and the concept of "entropic charge".


title:
A positivity-preserving scheme for the simulation of streamer discharges
  in non-attaching and attaching gases

abstract:
  Assumed having axial symmetry, the streamer discharge is often described by a
fluid model in cylindrical coordinate system, which consists of convection
dominated (diffusion) equations with source terms, coupled with a Poisson's
equation. Without additional care for a stricter CFL condition or special
treatment to the negative source term, popular methods used in streamer
discharge simulations, e.g., FEM-FCT, FVM, cannot ensure the positivity of the
particle densities for the cases in attaching gases. By introducing the
positivity-preserving limiter proposed by Zhang and Shu \cite{ppl} and Strang
operator splitting, this paper proposed a finite difference scheme with a
provable positivity-preserving property in cylindrical coordinate system, for
the numerical simulation of streamer discharges in non-attaching and attaching
gases. Numerical examples in non-attaching gas (N$_2$) and attaching gas
(SF$_6$) are given to illustrate the effectiveness of the scheme.


title: Relativistic global solutions of neutrino-dominated accretion flows

abstract:
  Neutrino-dominated accretion flows (NDAFs) around rotating stellar-mass black
holes are plausible candidates for the central engines of gamma-ray bursts
(GRBs). We investigate one-dimensional global solutions of NDAFs, taking
account of general relativity in Kerr metric, neutrino physics and
nucleosynthesis more precisely than previous works. We calculate sixteen
solutions with different characterized accretion rates and black hole spins to
exhibit the radial distributions of various physical properties in NDAFs.
\iffalse We find that the gas pressure and the neutrino cooling always become
dominated in the inner region for large accretion rate, $\gtrsim 0.1 M_\odot$
$\rm s^{-1}$. \fi We confirm that the electron degeneracy has important effects
in NDAFs and we find that the electron fraction is about 0.46 in the outer
region for all the sixteen solutions. From the perspective of the mass
fraction, free nucleons, $\rm ^4He$, and $\rm ^{56}Fe$ dominate in the inner,
middle, and outer region, respectively. The influence of neutrino trapping on
the annihilation is of importance for the superhigh accretion ($\dot
M=10M_{\odot} \rm s^{-1}$) and most of the sixteen solutions have an adequate
annihilation luminosity for GRBs.


title:
Plane wave stability of the split-step Fourier method for the nonlinear
  Schr\"odinger equation

abstract:
  Plane wave solutions to the cubic nonlinear Schr\"odinger equation on a torus
have recently been shown to behave orbitally stable. Under generic
perturbations of the initial data that are small in a high-order Sobolev norm,
plane waves are stable over long times that extend to arbitrary negative powers
of the smallness parameter. The present paper studies the question as to
whether numerical discretizations by the split-step Fourier method inherit such
a generic long-time stability property. This can indeed be shown under a
condition of linear stability and a non-resonance condition. They can both be
verified if the time step-size is restricted by a CFL condition in the case of
a constant plane wave. The proof first uses a Hamiltonian reduction and
transformation and then modulated Fourier expansions in time. It provides
detailed insight into the structure of the numerical solution.


title: Estimating population size using the network scale up method

abstract:
  We develop methods for estimating the size of hard-to-reach populations from
data collected using network-based questions on standard surveys. Such data
arise by asking respondents how many people they know in a specific group
(e.g., people named Michael, intravenous drug users). The Network Scale up
Method (NSUM) is a tool for producing population size estimates using these
indirect measures of respondents' networks. Killworth et al. [Soc. Netw. 20
(1998a) 23-50, Evaluation Review 22 (1998b) 289-308] proposed maximum
likelihood estimators of population size for a fixed effects model in which
respondents' degrees or personal network sizes are treated as fixed. We extend
this by treating personal network sizes as random effects, yielding principled
statements of uncertainty. This allows us to generalize the model to account
for variation in people's propensity to know people in particular subgroups
(barrier effects), such as their tendency to know people like themselves, as
well as their lack of awareness of or reluctance to acknowledge their contacts'
group memberships (transmission bias). NSUM estimates also suffer from recall
bias, in which respondents tend to underestimate the number of members of
larger groups that they know, and conversely for smaller groups. We propose a
data-driven adjustment method to deal with this. Our methods perform well in
simulation studies, generating improved estimates and calibrated uncertainty
intervals, as well as in back estimates of real sample data. We apply them to
data from a study of HIV/AIDS prevalence in Curitiba, Brazil. Our results show
that when transmission bias is present, external information about its likely
extent can greatly improve the estimates. The methods are implemented in the
NSUM R package.


title: Tamm-Hubbard surface states in the continuum

abstract:
  In the framework of the Bose-Hubbard model, we show that two-particle surface
bound states embedded in the continuum (BIC) can be sustained at the edge of a
semi-infinite one-dimensional tight-binding lattice for any
infinitesimally-small impurity potential $V$ at the lattice boundary. Such
thresholdless surface states, that can be referred to as Tamm-Hubbard BIC
states, exist provided that the impurity potential $V$ is attractive
(repulsive) and the particle-particle Hubbard interaction $U$ is repulsive
(attractive), i.e. for $UV<0$.


title: Observables of Macdonald processes

abstract:
  We present a framework for computing averages of various observables of
Macdonald processes. This leads to new contour--integral formulas for averages
of a large class of multilevel observables, as well as Fredholm determinants
for averages of two different single level observables.


title: Closed Light Paths in Equiangular Spiral Disks

abstract:
  A new type of deformation for microscopic laser disks, the
\textit{equiangular spiral deformation} is proposed. First a short review of
the geometry of light paths in equiangular spirals in the language of real
two-dimensional geometric calculus is given. Second, the constituting equations
for \textit{closed paths} inside equiangular spirals are derived. Third, their
numerical solution is performed and found to yield two generic types of closed
light paths. \textit{Degenerate} closed paths that exist over large intervals
of the deformation parameter, and \textit{nondegenerate} closed paths which
only exist over relatively small deformation parameter intervals spanning less
than 1% of the nondegenerate intervals. Fourth, amongst the nondegenerate paths
a \textit{stable asymmetric bow-tie} shaped light trajectory was found.


title:
Shock dynamics of strong imploding cylindrical and spherical shock waves
  with non-ideal gas effects

abstract:
  In this paper, the generalized analytical solution for one dimensional
adiabatic flow behind the strong imploding shock waves propagating in a
non-ideal gas is obtained by using the geometrical shock dynamics theory. The
equation of state for non-ideal gas as given by Landau and Lifshitz and the
generalized shock jump relations derived by Anand are taken into consideration
to explore the effects due to an increase in (i) the propagation distance from
the centre of convergence, (ii) the non-idealness parameter and, (iii) the
adiabatic index, on the shock velocity, pressure, density, particle velocity,
sound speed, adiabatic compressibility and the change in entropy across the
shock front. The findings provided a clear picture of whether and how the
non-idealness parameter and the adiabatic index affect the flow field behind
the strong imploding shock front.


title: Predictability of Event Occurrences in Timed Systems

abstract:
  We address the problem of predicting events' occurrences in partially
observable timed systems modelled by timed automata. Our contribution is
many-fold: 1) we give a definition of bounded predictability, namely
k-predictability, that takes into account the minimum delay between the
prediction and the actual event's occurrence; 2) we show that 0-predictability
is equivalent to the original notion of predictability of S. Genc and S.
Lafortune; 3) we provide a necessary and sufficient condition for
k-predictability (which is very similar to k-diagnosability) and give a simple
algorithm to check k-predictability; 4) we address the problem of
predictability of events' occurrences in timed automata and show that the
problem is PSPACE-complete.


title:
The Discovery and History of the Dalgaranga Meteorite Crater, Western
  Australia

abstract:
  The Dalgaranga meteorite crater, 100 km northeast of Yalgoo, Western
Australia, was one of the first impact structures identified in Australia, the
smallest isolated crater found in Australia, and the only confirmed crater in
the world associated with a mesosiderite projectile. 17 years passed before the
Dalgaranga meteorites were described in the scientific literature and nearly 40
years passed before a survey of the structure was published. The reasons for
the time-gap were never explained and a number of factual errors about the
discovery and early history remain uncorrected in the scientific literature.
Using historical and archival documents, and discussions with people involved
in Dalgaranga research, the reasons for this time gap are explained by a series
of minor misidentifications and coincidences. The age of the crater has yet to
be determined, but using published data, we estimate the projectile mass to be
500-1000 kg.


title: Neutron electric dipole moment in CP violating BLMSSM

abstract:
  Considering the CP violating phases, we analyze the neutron electric dipole
moment (EDM) in a CP violating supersymmetric extension of the standard model
where baryon and lepton numbers are local gauge symmetries(BLMSSM). The
contributions from the one loop diagrams and the Weinberg operators are taken
into account. Adopting some assumptions on the relevant parameter space, we
give the numerical results analysis. The numerical results for neutron EDM can
reach $1.05\times 10^{-25}(e.cm)$, which is about the experimental upper limit.


title: Narrative based Postdictive Reasoning for Cognitive Robotics

abstract:
  Making sense of incomplete and conflicting narrative knowledge in the
presence of abnormalities, unobservable processes, and other real world
considerations is a challenge and crucial requirement for cognitive robotics
systems. An added challenge, even when suitably specialised action languages
and reasoning systems exist, is practical integration and application within
large-scale robot control frameworks.
  In the backdrop of an autonomous wheelchair robot control task, we report on
application-driven work to realise postdiction triggered abnormality detection
and re-planning for real-time robot control: (a) Narrative-based knowledge
about the environment is obtained via a larger smart environment framework; and
(b) abnormalities are postdicted from stable-models of an answer-set program
corresponding to the robot's epistemic model. The overall reasoning is
performed in the context of an approximate epistemic action theory based
planner implemented via a translation to answer-set programming.


title: An Analysis of the Environments of FU Orionis Objects with Herschel

abstract:
  We present Herschel-HIFI, SPIRE, and PACS 50-670 {\mu}m imaging and
spectroscopy of six FU Orionis-type objects and candidates (FU Orionis, V1735
Cyg, V1515 Cyg, V1057 Cyg, V1331 Cyg, and HBC 722), ranging in outburst date
from 1936-2010, from the "FOOSH" (FU Orionis Objects Surveyed with Herschel)
program, as well as ancillary results from Spitzer-IRS and the Caltech
Submillimeter Observatory. In their system properties (Lbol, Tbol, line
emission), we find that FUors are in a variety of evolutionary states.
Additionally, some FUors have features of both Class I and II sources: warm
continuum consistent with Class II sources, but rotational line emission
typical of Class I, far higher than Class II sources of similar
mass/luminosity. Combining several classification techniques, we find an
evolutionary sequence consistent with previous mid-IR indicators. We detect [O
I] in every source at luminosities consistent with Class 0/I protostars, much
greater than in Class II disks. We detect transitions of 13CO (J_up of 5 to 8)
around two sources (V1735 Cyg and HBC 722) but attribute them to nearby
protostars. Of the remaining sources, three (FU Ori, V1515 Cyg, and V1331 Cyg)
exhibit only low-lying CO, but one (V1057 Cyg) shows CO up to J = 23 - 22 and
evidence for H2O and OH emission, at strengths typical of protostars rather
than T Tauri stars. Rotational temperatures for "cool" CO components range from
20-81 K, for ~ 10^50 total CO molecules. We detect [C I] and [N II] primarily
as diffuse emission.


title: Invisible defects in complex crystals

abstract:
  We show that invisible localized defects, i.e. defects that can not be
detected by an outside observer, can be realized in a crystal with an
engineered imaginary potential at the defect site. The invisible defects are
synthesized by means of supersymmetric (Darboux) transformations of an ordinary
crystal using band-edge wave functions to construct the superpotential. The
complex crystal has an entire real-valued energy spectrum and Bragg scattering
is not influenced by the defects. An example of complex crystal synthesis is
presented for the Mathieu potential.


title:
The formation of IRIS diagnostics I. A quintessential model atom of Mg
  II and general formation properties of the Mg II h&k lines

abstract:
  NASA's Interface Region Imaging Spectrograph (IRIS) space mission will study
how the solar atmosphere is energized. IRIS contains an imaging spectrograph
that covers the Mg II h&k lines as well as a slit-jaw imager centered at Mg II
k. Understanding the observations will require forward modeling of Mg II h&k
line formation from 3D radiation-MHD models. This paper is the first in a
series where we undertake this forward modeling. We discuss the atomic physics
pertinent to h&k line formation, present a quintessential model atom that can
be used in radiative transfer computations and discuss the effect of partial
redistribution (PRD) and 3D radiative transfer on the emergent line profiles.
We conclude that Mg II h&k can be modeled accurately with a 4-level plus
continuum Mg II model atom. Ideally radiative transfer computations should be
done in 3D including PRD effects. In practice this is currently not possible. A
reasonable compromise is to use 1D PRD computations to model the line profile
up to and including the central emission peaks, and use 3D transfer assuming
complete redistribution to model the central depression.


title: Shared Purity of Multipartite Quantum States

abstract:
  Fidelity plays an important role in measuring distances between pairs of
quantum states, of single as well as multiparty systems. Based on the concept
of fidelity, we introduce a physical quantity, shared purity, for arbitrary
pure or mixed quantum states of shared systems of an arbitrary number of
parties in arbitrary dimensions. We find that it is different from quantum
correlations. However, we prove that a maximal shared purity between two
parties excludes any shared purity of these parties with a third party, thus
ensuring its quantum nature. Moreover, we show that all generalized GHZ states
are monogamous, while all generalized W states are non-monogamous with respect
to this measure. We apply the quantity to investigate the quantum XY spin
models, and observe that it can faithfully detect the quantum phase transition
present in these models. We perform a finite-size scaling analysis and find the
scaling exponent for this quantity.


title: Klein tunneling of two correlated bosons

abstract:
  Reflection of two strongly interacting bosons with long-rage interaction
hopping on a one-dimensional lattice scattered off by a potential step is
theoretically investigated in the framework of the extended Hubbard model. The
analysis shows that, in the presence of unbalanced on-site and nearest-neighbor
site interaction, two strongly correlated bosons forming a bound particle state
can penetrate a high barrier, despite the single particle can not. Such a
phenomenon is analogous to one-dimensional Klein tunneling of a relativistic
massive Dirac particle across a potential step.


title:
The formation of IRIS diagnostics II. The formation of the Mg II h&k
  lines in the solar atmosphere

abstract:
  NASA's Interface Region Imaging Spectrograph (IRIS) small explorer mission
will study how the solar atmosphere is energized. IRIS contains an imaging
spectrograph that covers the Mg II h&k lines as well as a slit-jaw imager
centered at Mg II k. Understanding the observations requires forward modeling
of Mg II h&k line formation from 3D radiation-MHD models.
  We compute the vertically emergent h&k intensity from a snapshot of a dynamic
3D radiation-MHD model of the solar atmosphere, and investigate which
diagnostic information about the atmosphere is contained in the synthetic line
profiles. We find that the Doppler shift of the central line depression
correlates strongly with the vertical velocity at optical depth unity, which is
typically located less than 200 km below the transition region (TR). By
combining the Doppler shifts of the h and the k line we can retrieve the sign
of the velocity gradient just below the TR. The intensity in the central line
depression is anticorrelated with the formation height, especially in subfields
of a few square Mm. This intensity could thus be used to measure the spatial
variation of the height of the transition region. The intensity in the
line-core emission peaks correlates with the temperature at its formation
height, especially for strong emission peaks. The peaks can thus be exploited
as a temperature diagnostic. The wavelength difference between the blue and red
peaks provides a diagnostic of the velocity gradients in the upper
chromosphere. The intensity ratio of the blue and red peaks correlates strongly
with the average velocity in the upper chromosphere. We conclude that the Mg II
h&k lines are excellent probes of the very upper chromosphere just below the
transition region, a height regime that is impossible to probe with other
spectral lines.


title: Experimental Single-Photon Transmission from Satellite to Earth

abstract:
  Free-space quantum communication with satellites opens a promising avenue for
global secure quantum network and large-scale test of quantum foundations.
Recently, numerous experimental efforts have been carried out towards this
ambitious goal. However, one essential step - transmitting single photons from
the satellite to the ground with high signal-to-noise ratio (SNR) at realistic
environments - remains experimental challenging. Here, we report a direct
experimental demonstration of the satellite-ground transmission of a
quasi-single-photon source. In the experiment, single photons (~0.85 photon per
pulse) are generated by reflecting weak laser pulses back to earth with a
cube-corner retro-reflector on the satellite Champ, collected by a 600-mm
diameter telescope at the ground station, and finally detected by single-photon
counting modules (SPCMs) after 400-km free-space link transmission. With the
help of high accuracy time synchronization, narrow receiver field-of-view (FOV)
and high-repetition-rate pulses (76 MHz), a SNR of better than 16:1 is
obtained, which is sufficient for a secure quantum key distribution. Our
experimental results represent an important step towards satellite-ground
quantum communication.


title: Hadronic Resonance Production with ALICE Experiment at LHC

abstract:
  The production of resonances in heavy-ion collisions is expected to be
sensitive to the properties of strongly interacting matter created in such
collisions. We report on the measurements of $\phi$ and $K^{*0}$ resonances in
Pb-Pb collisions at $\sqrt{s_{NN}} $ = 2.76 TeV. The masses, widths and yields
in Pb-Pb collisions as a function of centrality are compared to that in pp
collisions to understand the role of re-scattering and regeneration. The
resonance to non-resonance particle ratios are shown as a function of collision
centrality and compared with the results at lower energies.


title: Quantum Correlations Induced by Local von Neumann Measurement

abstract:
  We study the total quantum correlation, semiquantum correlation and joint
quantum correlation induced by local von Neumann measurement in bipartite
system.We analyze the properties of these quantum correlations and obtain
analytical formula for pure states. The experimental witness for these quantum
correlations is further provided and the significance of these quantum
correlations is discussed in the context of local distinguishability of quantum
states.


title:
Absence of Floquet scattering in oscillating non-Hermitian potential
  wells

abstract:
  Scattering of a quantum particle from an oscillating barrier or well does not
generally conserve the particle energy owing to energy exchange with the photon
field, and an incoming particle-free state is scattered into a set of outgoing
(transmitted and reflected) free states according to Floquet scattering theory.
Here we introduce two families of oscillating non-Hermitian potential wells in
which Floquet scattering is fully suppressed for any energy of the incident
particle. The scattering-free oscillating potentials are synthesized by
application of the Darboux transformation to the time-dependent Schr\"{o}dinger
equation. For one of the two families of scattering-free potentials, the
oscillating potential turns out to be fully invisible.


title: Improving the quality of spatial quantum channels

abstract:
  We show, for the non-Markovian or time-dependent Markovian process, by
breaking up a spatial quantum channel (SQC) into a series of periodically
arranged sub-components, that the quality of information transmission described
by the purity, fidelity and concurrence of the output states can be improved.
The relation to the quantum zero effect and possible applications of the idea
have been discussed.


title: Transparency at the interface between two isospectral crystals

abstract:
  Reflection at an interface separating two different media is a rather
universal phenomenon which arises because of wave mismatching at the interface.
By means of supersymmetric quantum mechanics methods, it is shown that a fully
transparent interface can be realized, connecting two isospectral but different
one-dimensional crystals. An example of reflectionless interface is presented
for the sinusoidal (Mathieu) crystal connected to a non-sinusoidal potential by
a transparent domain wall.


title: Low-energy doublons in the ac-driven two-species Hubbard model

abstract:
  The hopping dynamics of two fermionic species with different effective masses
in the one-dimensional Hubbard model driven by an external field is
theoretically investigated. A multiple-time-scale asymptotic analysis of the
driven asymmetric Hubbard model shows that a high-frequency bichromatic
external field can sustain a new kind of low-energy particle bound state
(doublon), in which two fermions of different species occupy nearest neighbor
sites and co-tunnel along the lattice. The predictions of the asymptotic
analysis are confirmed by direct numerical simulations of the two-particle
Hubbard Hamiltonian.


title: Filament eruption on 2010 October 21 from three viewpoints

abstract:
  A filament eruption on 2010 October 21 observed from three different
viewpoints by the Solar Terrestrial Relations Observatory (STEREO) and the
Solar Dynamic Observatory (SDO) is analyzed with invoking also data from the
Solar and Heliospheric Observatory (SOHO) and the Kanzelhoehe Solar
Observatory. The position of the filament just before the eruption at the
central meridian not far from the center of the solar disk was favorable for
photospheric magnetic field measurements in the area below the filament.
Because of this, we were able to calculate with high precision the distribution
of the coronal potential magnetic field near the filament. We found that the
filament began to erupt when it approached the height in the corona where the
magnetic field decay index was greater than one. We determined also that during
the initial stage of the eruption the filament moved along the magnetic neutral
surface.