title:
The generation model of particle physics and the cosmological
  matter-antimatter asymmetry problem

abstract:
  The matter-antimatter asymmetry problem, corresponding to the virtual
nonexistence of antimatter in the universe, is one of the greatest mysteries of
cosmology. Within the framework of the Generation Model (GM) of particle
physics, it is demonstrated that the matter-antimatter asymmetry problem may be
understood in terms of the composite leptons and quarks of the GM. It is
concluded that there is essentially no matter-antimatter asymmetry in the
present universe and that the observed hydrogen-antihydrogen asymmetry may be
understood in terms of statistical fluctuations associated with the complex
many-body processes involved in the formation of either a hydrogen atom or an
antihydrogen atom.


title: Performance of a quantum heat engine at strong reservoir coupling

abstract:
  We study a quantum heat engine at strong coupling between the system and the
thermal reservoirs. Exploiting a collective coordinate mapping, we incorporate
system-reservoir correlations into a consistent thermodynamic analysis, thus
circumventing the usual restriction to weak coupling and vanishing
correlations. We apply our formalism to the example of a quantum Otto cycle,
demonstrating that the performance of the engine is diminished in the strong
coupling regime with respect to its weakly coupled counterpart, producing a
reduced net work output and operating at a lower energy conversion efficiency.
We identify costs imposed by sudden decoupling of the system and reservoirs
around the cycle as being primarily responsible for the diminished performance,
and define an alternative operational procedure which can partially recover the
work output and efficiency. More generally, the collective coordinate mapping
holds considerable promise for wider studies of thermodynamic systems beyond
weak reservoir coupling.


title: The Black Hole Information Problem

abstract:
  The black hole information problem has been a challenge since Hawking's
original 1975 paper. It led to the discovery of AdS/CFT, which gave a partial
resolution of the paradox. However, recent developments, in particular the
firewall puzzle, show that there is much that we do not understand. I review
the black hole, Hawking radiation, and the Page curve, and the classic form of
the paradox. I discuss AdS/CFT as a partial resolution. I then discuss black
hole complementarity and its limitations, leading to many proposals for
different kinds of `drama.' I conclude with some recent ideas.


title: Spin coefficients and gauge fixing in the Newman-Penrose formalism

abstract:
  Since its introduction in 1962, the Newman-Penrose formalism has been widely
used in analytical and numerical studies of Einstein's equations, like for
example for the Teukolsky master equation, or as a powerful wave extraction
tool in numerical relativity. Despite the many applications, Einstein's
equations in the Newman-Penrose formalism appear complicated and not easily
applicable to general studies of spacetimes, mainly because physical and gauge
degrees of freedom are mixed in a nontrivial way. In this paper we approach the
whole formalism with the goal of expressing the spin coefficients as functions
of tetrad invariants once a particular tetrad is chosen. We show that it is
possible to do so, and give for the first time a general recipe for the task,
as well as an indication of the quantities and identities that are required.


title:
Developments and difficulties in predicting the relative velocities of
  inertial particles at the small-scales of turbulence

abstract:
  In this paper, we use our recently developed theory for the backward-in-time
(BIT) relative dispersion of inertial particles in turbulence (Bragg \emph{et
al.}, Phys. Fluids 28, 013305, 2016) to develop the theoretical model by Pan \&
Padoan (J. Fluid Mech. 661 73, 2010) for inertial particle relative velocities
in isotropic turbulence. We focus on the most difficult regime to model, the
dissipation range, and find that the modified Pan \& Padoan model (that uses
the BIT dispersion theory) can lead to significantly improved predictions for
the relative velocities, when compared with Direct Numerical Simulation (DNS)
data. However, when the particle separation distance, $r$, is less than the
Kolmogorov length scale, $\eta$, the modified model overpredicts the DNS data.
We explain how these overpredictions arise from two assumptions in the BIT
dispersion theory, that are in general not satisfied when the final separation
of the BIT dispersing particles is $<\eta$. We then demonstrate the failure of
both the original and modified versions of the Pan \& Padoan model to predict
the correct scale-invariant forms for the inertial particle relative velocity
structure functions in the dissipation regime. It is shown how this failure,
which is also present in other models, is associated with our present inability
to correctly predict not only the quantitative, but also the qualitative
behavior of the Radial Distribution Function in the dissipation range when
$St=\mathcal{O}(1)$


title: Asymmetric truncated Toeplitz operators equal to the zero operator

abstract:
  Asymmetric truncated Toeplitz operators are compressions of multiplication
operators acting between two model spaces. These operators are natural
generalizations of truncated Toeplitz operators. In this paper we describe
symbols of asymmetric truncated Toeplitz operators equal to the zero operator.


title:
Diffusive estimates for random walks on stationary random graphs of
  polynomial growth

abstract:
  Let $(G,\rho)$ be a stationary random graph, and use $B^G_{\rho}(r)$ to
denote the ball of radius $r$ about $\rho$ in $G$. Suppose that $(G,\rho)$ has
annealed polynomial growth, in the sense that $\mathbb{E}[|B^G_{\rho}(r)|] \leq
O(r^k)$ for some $k > 0$ and every $r \geq 1$.
  Then there is an infinite sequence of times $\{t_n\}$ at which the random
walk $\{X_t\}$ on $(G,\rho)$ is at most diffusive: Almost surely (over the
choice of $(G,\rho)$), there is a number $C > 0$ such that \[ \mathbb{E}
\left[\mathrm{dist}_G(X_0, X_{t_n})^2 \mid X_0 = \rho, (G,\rho)\right]\leq C
t_n\qquad \forall n \geq 1\,. \] This result is new even in the case when $G$
is a stationary random subgraph of $\mathbb{Z}^d$. Combined with the work of
Benjamini, Duminil-Copin, Kozma, and Yadin (2015), it implies that $G$ almost
surely does not admit a non-constant harmonic function of sublinear growth.
  To complement this, we argue that passing to a subsequence of times $\{t_n\}$
is necessary, as there are stationary random graphs of (almost sure) polynomial
growth where the random walk is almost surely superdiffusive at an infinite
subset of times.


title:
The Gould's Belt Distances Survey (GOBELINS) II. Distances and structure
  towards the Orion Molecular Clouds

abstract:
  We present the results of the Gould's Belt Distances Survey (GOBELINS) of
young star forming regions towards the Orion Molecular Cloud Complex. We
detected 36 YSOs with the Very Large Baseline Array (VLBA), 27 of which have
been observed in at least 3 epochs over the course of 2 years. At least half of
these YSOs belong to multiple systems. We obtained parallax and proper motions
towards these stars to study the structure and kinematics of the Complex. We
measured a distance of 388$\pm$5 pc towards the Orion Nebula Cluster,
428$\pm$10 pc towards the southern portion L1641, 388$\pm$10 pc towards NGC
2068, and roughly $\sim$420 pc towards NGC 2024. Finally, we observed a strong
degree of plasma radio scattering towards $\lambda$ Ori.


title: Building Blocks of the Milky Way's Accreted Spheroid

abstract:
  In the $\Lambda$CDM model of structure formation, a stellar spheroid grows by
the assembly of smaller galaxies, the so-called building blocks. Combining the
Munich-Groningen semi-analytical model of galaxy formation with the high
resolution Aquarius simulations of dark matter haloes, we study the assembly
history of the stellar spheroids of six Milky Way-mass galaxies, focussing on
building block properties such as mass, age and metallicity. These properties
are compared to those of the surviving satellites in the same models. We find
that the building blocks have higher star formation rates on average, and this
is especially the case for the more massive objects. At high redshift these
dominate in star formation over the satellites, whose star formation timescales
are longer on average. These differences ought to result in a larger
$\alpha$-element enhancement from Type II supernovae in the building blocks
(compared to the satellites) by the time Type Ia supernovae would start to
enrich them in iron, explaining the observational trends. Interestingly, there
are some variations in the star formation timescales of the building blocks
amongst the simulated haloes, indicating that [$\alpha$/Fe] abundances in
spheroids of other galaxies might differ from those in our own Milky Way.


title: Elastic image registration with exact mass preservation

abstract:
  We establish a new framework for image registration, which is based on linear
elasticity and optimal mass transportation theory. We combine these two
arguments in order to obtain a PDE constrained optimization problem that is
analytically investigated and further discretized with the finite difference
method and solved by an inexact SQP algorithm. This requires to solve in each
step a large sparse linear system, which has a saddle point form. Motivated by
stability arguments we use a fully staggered grid for the discretization of the
displacement vector field. Artificial and real world examples are presented to
underline the numerical robustness of the method.


title: Optimizing floating guard ring designs for FASPAX N-in-P silicon sensors

abstract:
  FASPAX (Fermi-Argonne Semiconducting Pixel Array X-ray detector) is being
developed as a fast integrating area detector with wide dynamic range for time
resolved applications at the upgraded Advanced Photon Source (APS.) A burst
mode detector with intended $\mbox{13 $MHz$}$ image rate, FASPAX will also
incorporate a novel integration circuit to achieve wide dynamic range, from
single photon sensitivity to $10^{\text{5}}$ x-rays/pixel/pulse. To achieve
these ambitious goals, a novel silicon sensor design is required. This paper
will detail early design of the FASPAX sensor. Results from TCAD optimization
studies, and characterization of prototype sensors will be presented.


title: Hori-mological projective duality

abstract:
  Kuznetsov has conjectured that Pfaffian varieties should admit
non-commutative crepant resolutions which satisfy his Homological Projective
Duality. We prove half the cases of this conjecture, by interpreting and
proving a duality of non-abelian gauged linear sigma models proposed by Hori.


title: Quantum heat waves in a one-dimensional condensate

abstract:
  We study the dynamics of phase relaxation between a pair of one-dimensional
condensates created by a bi-directional, supersonic `unzipping' of a finite
single condensate. We find that the system fractures into different
\emph{extensive} chunks of space-time, within which correlations appear thermal
but correspond to different effective temperatures. Coherences between
different eigen-modes are crucial for understanding the development of such
thermal correlations; at no point in time can our system be described by a
generalized Gibbs' ensemble despite nearly always appearing locally thermal. We
rationalize a picture of propagating fronts of hot and cold sound waves,
populated at effective, relativistically red- and blue-shifted temperatures to
intuitively explain our findings. The disparity between these hot and cold
temperatures vanishes for the case of instantaneous splitting but diverges in
the limit where the splitting velocity approaches the speed of sound; in this
limit, a sonic boom occurs wherein the system is excited only along an
infinitely narrow, and infinitely hot beam. We expect our findings to apply
generally to the study of superluminal perturbations in systems with emergent
Lorentz symmetry.


title:
Optical transitions in two-dimensional topological insulators with point
  defects

abstract:
  Nontrivial properties of electronic states in topological insulators are
inherent not only to the surface and boundary states, but to bound states
localized at structure defects as well. We clarify how the unusual properties
of the defect-induced bound states are manifested in optical absorption spectra
in two-dimensional topological insulators. The calculations are carried out for
defects with short-range potential. We find that the defects give rise to the
appearance of specific features in the absorption spectrum, which are an
inherent property of topological insulators. They have the form of two or three
absorption peaks that are due to intracenter transitions between electron-like
and hole-like bound states.


title:
Real-time observation of a coherent lattice transformation into a
  high-symmetry phase

abstract:
  Excursions far from their equilibrium structures can bring crystalline solids
through collective transformations including transitions into new phases that
may be transient or long-lived. Direct spectroscopic observation of
far-from-equilibrium rearrangements provides fundamental mechanistic insight
into chemical and structural transformations, and a potential route to
practical applications, including ultrafast optical control over material
structure and properties. However, in many cases photoinduced transitions are
irreversible or only slowly reversible, or the light fluence required exceeds
material damage thresholds. This precludes conventional ultrafast spectroscopy
in which optical excitation and probe pulses irradiate the sample many times,
each measurement providing information about the sample response at just one
probe delay time following excitation, with each measurement at a high
repetition rate and with the sample fully recovering its initial state in
between measurements. Using a single-shot, real-time measurement method, we
were able to observe the photoinduced phase transition from the semimetallic,
low-symmetry phase of crystalline bismuth into a high-symmetry phase whose
existence at high electronic excitation densities was predicted based on
earlier measurements at moderate excitation densities below the damage
threshold. Our observations indicate that coherent lattice vibrational motion
launched upon photoexcitation with an incident fluence above 10 mJ/cm2 in bulk
bismuth brings the lattice structure directly into the high-symmetry
configuration for tens of picoseconds, after which carrier relaxation and
diffusion restore the equilibrium lattice configuration.


title: Constructing UMEB from maximally entangled basis

abstract:
  A new way of constructing unextendible maximally entangled basis (UMEB) from
maximally entangled basis (MEB) is proposed. Consequently, it is shown that if
there is an $N$-member UMEB in $\mathbb{C}^d\otimes \mathbb{C}^d$, then there
exists a $(qd)^2-q(d^2-N)$-member UMEB in $\mathbb{C}^{qd}\otimes
\mathbb{C}^{qd}$ for any $q\in\mathbb{N}$. This improves the results in [Phys.
Rev. A 90, 034301(2014)], which shows that there exists a
$(qd)^2-(d^2-N)$-member UMEB in $\mathbb{C}^{qd}\otimes \mathbb{C}^{qd}$
provided that an $N$-member UMEB exsits in $\mathbb{C}^d\otimes \mathbb{C}^d$.
In addition, a very easy way of constructing UMEB in $\mathbb{C}^d\otimes
\mathbb{C}^{d'}$ with $d<d'$ is presented, which promotes and covers all the
previous related work.


title: A discrete, finite multiverse

abstract:
  The Many Worlds Interpretation (MWI) famously avoids the issue of wave
function collapse. Different MWI trees representing the same quantum events can
have different topologies, depending upon the observer. However, they are all
isomorphic to the group of block universes containing all of the outcomes of
all of the events, and so, in that sense, the group of block universes is a
more fundamental representation. Different branches of the MWI tree,
representing different universes in MWI, ultimately share the same quantum
state in a common ancestor branch. This branching topology is incompatible with
that of the Minkowski block universe; the resolution is to replace the branches
with discrete, parallel block universes, each of which extends from the trunk
to the outermost twigs. The number of universes in a branch is proportional to
its thickness which, in turn, depends upon the absolute square of the
probability amplitude for the state in that branch. Every quantum event may be
represented by a kernel of universes, which is the smallest group of universes
that will reproduce the quantum probabilities of the outcomes of that event. By
considering the ratios of the probabilities of the outcomes of any event, it
can be shown that the number of universes in every kernel must finite, as must
be the total number of universes in the multiverse. Further, every universe in
the multiverse must be finite both in space and time. Another consequence is
that quantum probabilities must be rational, which suggests that quantum
mechanics is only an approximation to a discrete theory. A corollary is that
not every conceivable universe exists in the multiverse, no doubt to the
disappointment of those who enjoy alternate-history novels.


title: Opting Into Optimal Matchings

abstract:
  We revisit the problem of designing optimal, individually rational matching
mechanisms (in a general sense, allowing for cycles in directed graphs), where
each player --- who is associated with a subset of vertices --- matches as many
of his own vertices when he opts into the matching mechanism as when he opts
out. We offer a new perspective on this problem by considering an arbitrary
graph, but assuming that vertices are associated with players at random. Our
main result asserts that, under certain conditions, any fixed optimal matching
is likely to be individually rational up to lower-order terms. We also show
that a simple and practical mechanism is (fully) individually rational, and
likely to be optimal up to lower-order terms. We discuss the implications of
our results for market design in general, and kidney exchange in particular.


title: On classes of C3 and D3 modules

abstract:
  The aim of this paper is to study the notions of $\mathcal{A}$-C3 and
$\mathcal{A}$-D3 modules for some class $\mathcal{A}$ of right modules. Several
characterizations of these modules are provided and used to describe some
well-known classes of rings and modules. For example, a regular right
$R$-module $F$ is a $V$-module if and only if every $F$-cyclic module $M$ is an
$\mathcal{A}$-C3 module where $\mathcal{A}$ is the class of all simple
submodules of $M$. Moreover, let $R$ be a right artinian ring and
$\mathcal{A}$, a class of right $R$-modules with local endomorphisms,
containing all simple right $R$-modules and closed under isomorphisms. If all
right $R$-modules are $\mathcal{A}$-injective, then $R$ is a serial artinian
ring with $J^{2}(R)=0$ if and only if every $\mathcal{A}$-C3 right $R$-module
is quasi-injective, if and only if every $\mathcal{A}$-C3 right $R$-module is
C3.


title: Distributed Algorithms for Peak Ramp Minimization Problem in Smart Grid

abstract:
  The arrival of small-scale distributed energy generation in the future smart
grid has led to the emergence of so-called prosumers, who can both consume as
well as produce energy. By using local generation from renewable energy
resources, the stress on power generation and supply system can be
significantly reduced during high demand periods. However, this also creates a
significant challenge for conventional power plants that suddenly need to ramp
up quickly when the renewable energy drops off. In this paper, we propose an
energy consumption scheduling problem for prosumers to minimize the peak ramp
of the system. The optimal schedule of prosumers can be obtained by solving the
centralized optimization problem. However, due to the privacy concerns and the
distributed topology of the power system, the centralized design is difficult
to implement in practice. Therefore, we propose the distributed algorithms to
efficiently solve the centralized problem using the alternating direction
method of multiplier (ADMM), in which each prosumer independently schedules its
energy consumption profile. The simulation results demonstrate the convergence
performance of the proposed algorithms as well as the capability of our model
in reducing the peak ramp of the system.


title:
First Breakthrough for Future Air-Breathing Magneto-Plasma Propulsion
  Systems

abstract:
  A new breakthrough in jet propulsion technology since the invention of the
jet engine is achieved. The first critical tests for future air-breathing
magneto-plasma propulsion systems have been successfully completed. In this
regard, it is also the first time that a pinching dense plasma focus discharge
could be ignited at one atmosphere and driven in pulse mode using very fast,
nanosecond electrostatic excitations to induce self-organized plasma channels
for ignition of the propulsive main discharge. Depending on the capacitor
voltage (200-600 V) the energy input at one atmosphere varies from 52-320
J/pulse corresponding to impulse bits from 1.2-8.0 mNs. Such a new pulsed
plasma propulsion system driven with one thousand pulses per second would
already have thrust-to-area ratios (50-150 kN/m2) of modern jet engines. An
array of thrusters could enable future aircrafts and airships to start from
ground and reach altitudes up to 50km and beyond. The needed high power could
be provided by future compact plasma fusion reactors already in development by
aerospace companies. The magneto-plasma compressor itself was originally
developed by Russian scientists as plasma fusion device and was later
miniaturized for supersonic flow control applications. So the first
breakthrough is based on a spin-off plasma fusion technology.


title: Differential smoothness of skew polynomial rings

abstract:
  It is shown that, under some natural assumptions, the tensor product of
differentially smooth algebras and the skew-polynomial rings over
differentially smooth algebras are differentially smooth.


title:
Decoupled limbs yield differentiable trajectory outcomes through
  intermittent contact in locomotion and manipulation

abstract:
  When limbs are decoupled, we find that trajectory outcomes in mechanical
systems subject to unilateral constraints vary differentiably with respect to
initial conditions, even as the contact mode sequence varies.


title:
Geometric Ergodicity of Gibbs Samplers in Bayesian Penalized Regression
  Models

abstract:
  We consider three Bayesian penalized regression models and show that the
respective deterministic scan Gibbs samplers are geometrically ergodic
regardless of the dimension of the regression problem. We prove geometric
ergodicity of the Gibbs samplers for the Bayesian fused lasso, the Bayesian
group lasso, and the Bayesian sparse group lasso. Geometric ergodicity along
with a moment condition results in the existence of a Markov chain central
limit theorem for Monte Carlo averages and ensures reliable output analysis.
Our results of geometric ergodicity allow us to also provide default starting
values for the Gibbs samplers.


title:
Existence of minimal hypersurfaces in complete manifolds of finite
  volume

abstract:
  We prove that every complete non-compact manifold of finite volume contains a
(possibly non-compact) minimal hypersurface of finite volume. The main tool is
the following result of independent interest: if a region $U$ can be swept out
by a family of hypersurfaces of volume at most $V$, then it can be swept out by
a family of mutually disjoint hypersurfaces of volume at most $V +
\varepsilon$.


title: Integrable systems of double ramification type

abstract:
  In this paper we study various aspects of the double ramification (DR)
hierarchy, introduced by the first author, and its quantization. We extend the
notion of tau-symmetry to quantum integrable hierarchies and prove that the
quantum DR hierarchy enjoys this property. We determine explicitly the genus
$1$ quantum correction and, as an application, compute completely the
quantization of the $3$- and $4$-KdV hierarchies (the DR hierarchies for
Witten's $3$- and $4$-spin theories). We then focus on the recursion relation
satisfied by the DR Hamiltonian densities and, abstracting from its geometric
origin, we use it to characterize and construct a new family of quantum and
classical integrable systems which we call of double ramification type, as they
satisfy all of the main properties of the DR hierarchy. In the second part, we
obtain new insight towards the Miura equivalence conjecture between the DR and
Dubrovin-Zhang hierarchies, via a geometric interpretation of the correlators
forming the double ramification tau-function. We then show that the candidate
Miura transformation between the DR and DZ hierarchies (which we uniquely
identified in our previous paper) indeed turns the Dubrovin-Zhang Poisson
structure into the standard form. Eventually, we focus on integrable
hierarchies associated with rank-$1$ cohomological field theories and their
deformations, and we prove the DR/DZ equivalence conjecture up to genus $5$ in
this context.


title:
Privacy-by-Design Framework for Assessing Internet of Things
  Applications and Platforms

abstract:
  The Internet of Things (IoT) systems are designed and developed either as
standalone applications from the ground-up or with the help of IoT middleware
platforms. They are designed to support different kinds of scenarios, such as
smart homes and smart cities. Thus far, privacy concerns have not been
explicitly considered by IoT applications and middleware platforms. This is
partly due to the lack of systematic methods for designing privacy that can
guide the software development process in IoT. In this paper, we propose a set
of guidelines, a privacy-by-design framework, that can be used to assess
privacy capabilities and gaps of existing IoT applications as well as
middleware platforms. We have evaluated two open source IoT middleware
platforms, namely OpenIoT and Eclipse SmartHome, to demonstrate how our
framework can be used in this way.


title:
Inertia-less convectively-driven dynamo models in the limit of low
  Rossby number and large Prandtl number

abstract:
  Compositional convection is thought to be an important energy source for
magnetic field generation within planetary interiors. The Prandtl number, $Pr$,
characterizing compositional convection is significantly larger than unity,
suggesting that the inertial force may not be important on the small scales of
convection as long as the buoyancy force is not too strong. We develop
asymptotic dynamo models for the case of small Rossby number and large Prandtl
number in which inertia is absent on the convective scale. The relevant
diffusivity parameter for this limit is the compositional Roberts number, $q =
D/\eta$, which is the ratio of compositional and magnetic diffusivities. Dynamo
models are developed for both order one $q$ and the more geophysically relevant
low $q$ limit. For both cases the ratio of magnetic to kinetic energy
densities, $M$, is asymptotically large and reflects the fact that Alfv\'en
waves have been filtered from the dynamics. Along with previous investigations
of asymptotic dynamo models for $Pr=O(1)$, our results show that the ratio $M$
is not a useful indicator of dominant force balances in the momentum equation
since many different asymptotic limits of $M$ can be obtained without changing
the leading order geostrophic balance. Furthermore, the present models show
that inertia is not a requirement for driving low $q$, large-scale dynamos.


title: A new basis for the complex $K$-theory cooperations algebra

abstract:
  A classical theorem of Adams, Harris, and Switzer states that the 0th grading
of complex $K$-theory cooperations, $KU_0ku$ is isomorphic to the space of
numerical polynomials. The space of numerical polynomials has a basis provided
by the binomial coefficient polynomials, which gives a basis of $KU_0ku$. In
this paper, we produce a new $p$-local basis for $KU_0ku_{(p)}$ using the Adams
splitting. This basis is established by using well known formulas for the
Hazewinkel generators. For $p=2$, we show that this new basis coincides with
the classical basis modulo higher Adams filtration.


title: Characterisation of red supergiants in the Gaia spectral range

abstract:
  The infrared Calcium Triplet and its nearby spectral region have been used
for spectral and luminosity classification of late-type stars, but the samples
of cool supergiants (CSGs) used have been very limited (in size, metallicity
range, and spectral types covered). The spectral range of the Gaia Radial
Velocity Spectrograph (RVS) covers most of this region but does not reach the
main TiO bands in this region, whose depths define the M sequence. We study the
behaviour of spectral features around the Calcium Triplet and develop effective
criteria to identify and classify CSGs, comparing their efficiency with other
methods previously proposed. We measure the main spectral features in a large
sample (almost 600) of CSGs from three different galaxies, and we analyse their
behaviour through a principal component analysis. Using the principal
components, we develop an automatised method to differentiate CSGs from other
bright late-type stars, and to classify them. The proposed method identifies a
high fraction of the supergiants (SGs) in our test sample, which cover a wide
metallicity range (SGs from the SMC, the LMC, and the Milky Way) and with
spectral types from G0 up to late-M. In addition, it is capable to separate
most of the non-SGs in the sample, identifying as SGs only a very small
fraction of them. A comparison of this method with other previously proposed
shows that it is more efficient and selects less interlopers. A way to
automatically assign a spectral type to the SGs is also developed. We apply
this study to spectra at the resolution and spectral range of the Gaia RVS,
with a similar success rate. The method developed identifies and classifies
CSGs in large samples, with high efficiency and low contamination, even in
conditions of wide metallicity and spectral-type ranges.


title:
A generalized Chebyshev Finite Difference method for higher order
  boundary value problems

abstract:
  A general formula is presented for any order derivative of Chebyshev
polynomials instead of the existing recursive relationship. Hence, the
Chebyshev finite difference method is made applicable not only to second order
problems but also to higher order boundary value problems. The generalized
method is applied to a variety of higher order boundary value problems and it
is seen that the obtained results are more accurate than the other numerical
methods in absolute error.


title:
Closed-form solutions for worst-case law invariant risk measures with
  application to robust portfolio optimization

abstract:
  Worst-case risk measures refer to the calculation of the largest value for
risk measures when only partial information of the underlying distribution is
available. For the popular risk measures such as Value-at-Risk (VaR) and
Conditional Value-at-Risk (CVaR), it is now known that their worst-case
counterparts can be evaluated in closed form when only the first two moments
are known for the underlying distribution. These results are remarkable since
they not only simplify the use of worst-case risk measures but also provide
great insight into the connection between the worst-case risk measures and
existing risk measures. We show in this paper that somewhat surprisingly
similar closed-form solutions also exist for the general class of law invariant
coherent risk measures, which consists of spectral risk measures as special
cases that are arguably the most important extensions of CVaR. We shed light on
the one-to-one correspondence between a worst-case law invariant risk measure
and a worst-case CVaR (and a worst-case VaR), which enables one to carry over
the development of worst-case VaR in the context of portfolio optimization to
the worst-case law invariant risk measures immediately.

categories: q-fin.RM math.OC q-fin.CP q-fin.MF q-fin.PM


title: Group invariance of integrable Pfaffian systems

abstract:
  Let $\mathcal{S}$ be an integrable Pfaffian system. If it is invariant under
a transversally free infinitesimal action of a finite dimensional real Lie
algebra $g$ and consequently invariant under the local action of a Lie group
$G$, we show that the vertical variational cohomology of $\mathcal{S}$ is equal
to the Lie algebra cohomology of $g$ with values in the space of the horizontal
cohomology in maximum dimension. This result, besides giving an effective
algorithm for the computation of the variational cohomology of an invariant
Pfaffian system, provides a method for detecting obstructions to the existence
of finite or infinitesimal actions leaving a given system invariant.


title: Quantum repeater based on cavity-QED evolutions and coherent light

abstract:
  In the framework of cavity QED, we propose a quantum repeater scheme that
uses coherent light and chains of atoms coupled to optical cavities. In
contrast to conventional repeater schemes, we avoid the usage of two-qubit
quantum logical gates by exploiting solely the cavity QED evolution. In our
previous paper [D. Gonta and P. van Loock: Phys. Rev. A 88, 052308 (2013)], we
already proposed a quantum repeater in which the entanglement between two
neighboring repeater nodes was distributed using controlled displacements of
input coherent light, while the produced low-fidelity entangled pairs were
purified using ancillary (four-partite) entangled states. In this paper, the
entanglement distribution is realized using a sequence of controlled phase
shifts and displacements of input coherent light. Compared to previous
coherent-state-based distribution schemes for two-qubit entanglement, the
present scheme relies only upon a simple discrimination of two coherent states
with opposite signs, which can be performed in a quantum mechanically optimal
fashion via a beam splitter and two on-off detectors. The entanglement
purification utilizes a scheme that avoids the usage of ancillary entangled
resources. Our repeater scheme exhibits reasonable fidelities and repeater
rates providing an attractive platform for long-distance quantum communication.


title:
Study of X(5568) in a unitary coupled-channel approximation of $B
  \bar{K}$ and $B_s \pi$

abstract:
  The potential of the $B$ meson and the pseudoscalar meson is constructed up
to the next-to-leading order Lagrangian, and then the $B \bar{K}$ and $B_s \pi$
interaction is studied in the unitary coupled-channel approximation, and a
resonant state with a mass about $5568MeV$ and $J^P=0^+$ is generated
dynamically, which can be associated with the $X(5568)$ state announced by D0
Collaboration recently. The mass and the decay width of this resonant state
depend on the regularization scale in the dimensional regularization scheme, or
the maximum momentum in the momentum cutoff regularization scheme. The
scattering amplitude of the vector $B$ meson and the pseudoscalar meson is
calculated, and an axial-vector state with a mass near $5620MeV$ and $J^P=1^+$
is produced. Moreover, their partners in the charm sector are also discussed.


title:
A Survey of Multi-Objective Optimization in Wireless Sensor Networks:
  Metrics, Algorithms and Open Problems

abstract:
  Wireless sensor networks (WSNs) have attracted substantial research interest,
especially in the context of performing monitoring and surveillance tasks.
However, it is challenging to strike compelling trade-offs amongst the various
conflicting optimization criteria, such as the network's energy dissipation,
packet-loss rate, coverage and lifetime. This paper provides a tutorial and
survey of recent research and development efforts addressing this issue by
using the technique of multi-objective optimization (MOO). First, we provide an
overview of the main optimization objectives used in WSNs. Then, we elaborate
on various prevalent approaches conceived for MOO, such as the family of
mathematical programming based scalarization methods, the family of
heuristics/metaheuristics based optimization algorithms, and a variety of other
advanced optimization techniques. Furthermore, we summarize a range of recent
studies of MOO in the context of WSNs, which are intended to provide useful
guidelines for researchers to understand the referenced literature. Finally, we
discuss a range of open problems to be tackled by future research.


title:
Asymptotic shape and the speed of propagation of continuous-time
  continuous-space birth processes

abstract:
  We formulate and prove a shape theorem for a continuous-time continuous-space
stochastic growth model under certain general conditions. Similarly to the
classical lattice growth models the proof makes use of the subadditive ergodic
theorem. A precise expression for the speed of propagation is given in the case
of a truncated free branching birth rate.


title:
Book Review of Susan Greenfield's 'Mind Change: How Digital Technologies
  Are Leaving Their Mark On Our Brains'

abstract:
  This is a review of Susan Greenfield's 2015 book 'Mind Change: How Digital
Technologies Are Leaving Their Mark On Our Brains'. Greenfield is a
neuroscientist and a member of the UK House of Lords, who argues that digital
technologies are changing the human environment "in an unprecedented way," and
that by adapting to this environment, "the brain may also be changing in an
unprecedented way." The book and its author have created a surprising amount of
controversy. I discuss both Greenfield's book and a prominent critique by Bell
et al. (2015). The exchange points to some flaws in Greenfield's argument and
represents an interesting debate about the public role of scientists, but it
does not undermine the value of the book as a springboard for discussions about
possible policies and future research.


title: Weakly globular N-fold categories as a model of weak N-categories

abstract:
  We study a new type of higher categorical structure, called weakly globular
n-fold category, previously introduced by the author. We show that this
structure is a model of weak n-categories by proving that it is suitably
equivalent to the Tamsamani-Simpson model. We also introduce groupoidal weakly
globular n-fold categories and show that they are algebraic models of n-types.


title:
Surface plasmon enhancement of spontaneous emission in graphene
  waveguides

abstract:
  This work analyzes the spontaneous emission of a single emitter placed near
the graphene waveguide formed by two parallel graphene monolayers, with an
insulator spacer layer. In this case, the eigenmodes supported by the
structure, such as surface plasmon and wave guided modes, provide decay
channels for the electric dipole placed close to the waveguide. We calculated
the contribution to the decay rate of symmetric and antisymmetric eigenmodes as
a function of frequency and the orientation of the emitter. Our results show
that the modification of the spontaneous emission due to excitation of guided
modes is much lower than the corresponding decays through the excitation of
symmetric and antisymmetric surface plasmons, for which, the spontaneous
emission is dramatically enhanced. As a consequence of the high confinement of
surface plasmons in the graphene waveguide, we found that the decay rate of the
emitter with vertical orientation (with respect to graphene sheets) is twice
the corresponding decay of the same emitter with parallel orientation in the
whole frequency range where surface plasmon modes exist. Differently from
metallo- dielectric structures, where structural parameters determine the range
and magnitude of this emission, our work shows that, by dynamically tuning the
chemical potential of graphene, the spectral region where the decay rate is
enhanced can be chosen over a wide range.


title: Bloch's conjecture for the surface of Craighero and Gattazzo

abstract:
  The goal of this paper is to prove Bloch's conjecture for the numerical
Godeaux surface constructed by P. Craighero and R. Gattazzo.


title:
Solving close-coupling equations in momentum space without singularities
  for charged targets

abstract:
  The analytical treatment of the Greens function in the convergent
close-coupling method [Bray et al. Comp. Phys. Comm. 203 147 (2016)] has been
extended to charged targets. Furthermore, we show that this approach allows for
calculation of cross sections at zero channel energy. For neutral targets this
means the electron scattering length may be obtained from a single calculation
with zero incident energy. For charged targets the non-zero excitation cross
sections at thresholds can also be calculated by simply setting the incident
energy to the exact threshold value. These features are demonstrated by
considering electron scattering on H and He+.


title:
Unravelling the complex structure of AGN-driven outflows: II.
  Photoionization and energetics

abstract:
  Outflows have been shown to be prevalent in galaxies hosting luminous active
galactic nuclei (AGNs) and present a physically plausible way to couple the AGN
energy output with the interstellar medium of their hosts. Despite their
prevalence, accurate characterization of these outflows has been challenging.
In the second of a series of papers, we use Gemini Multi-Object Spectrograph
IFU data of 6 local (z<0.1) and moderate-luminosity Type 2 AGNs to study the
ionization properties and energetics of AGN-driven outflows. We find strong
evidence that connect the extreme kinematics of the ionized gas with the AGN
photoionization. The kinematic component related to the AGN-driven outflow is
clearly separated from other kinematic components, such as virial motions or
rotation, on the velocity and velocity dispersion diagram. Our spatially
resolved kinematic analysis reveals that from 30% up to 90% of the total mass
and kinetic energy of the outflow is contained within the central kpc of the
galaxy. The spatially integrated mass and kinetic energy of the gas entrained
in the outflow correlates well with the AGN bolometric luminosity and results
in energy conversion efficiencies between 0.01% and 1%. Intriguingly, we detect
ubiquitous signs of ongoing circumnuclear star formation. Their small size, the
centrally contained mass and energy, and the universally detected circumnuclear
star formation cast doubts on the potency of these AGN-driven outflows as
agents of galaxy-scale negative feedback.


title: From skein theory to presentations for Thompson group

abstract:
  Jones introduced unitary representations of Thompson group $F$ starting from
a given subfactor planar algebra, and all unoriented links arise as matrix
coefficients of these representations. Moreover, all oriented links arise as
matrix coefficients of a subgroup $\vec{F}$ which is the stabilizer of a
certain vector. Later Golan and Sapir determined the subgroup $\vec{F}$ and
showed many interesting properties. In this paper, we investigate into a large
class of groups which arises as subgroups of Thompson group $F$ and reveal the
relation between the skein theory of the subfactor planar algebra and the
presentation of subgroup related to the corresponding unitary representation.
Specifically, we answer a question by Jones about the 3-colorable subgroup.


title: Bayesian survival analysis of batsmen in Test cricket

abstract:
  Cricketing knowledge tells us batting is more difficult early in a player's
innings but becomes easier as a player familiarizes themselves with the
conditions. In this paper, we develop a Bayesian survival analysis method to
predict the Test Match batting abilities for international cricketers. The
model is applied in two stages, firstly to individual players, allowing us to
quantify players' initial and equilibrium batting abilities, and the rate of
transition between the two. This is followed by implementing the model using a
hierarchical structure, providing us with more general inference concerning a
selected group of opening batsmen from New Zealand. The results indicate most
players begin their innings playing with between only a quarter and half of
their potential batting ability. Using the hierarchical structure we are able
to make predictions for the batting abilities of the next opening batsman to
debut for New Zealand. Additionally, we compare and identify players who excel
in the role of opening the batting, which has practical implications in terms
of batting order and team selection policy.


title: Single-image RGB Photometric Stereo With Spatially-varying Albedo

abstract:
  We present a single-shot system to recover surface geometry of objects with
spatially-varying albedos, from images captured under a calibrated RGB
photometric stereo setup---with three light directions multiplexed across
different color channels in the observed RGB image. Since the problem is
ill-posed point-wise, we assume that the albedo map can be modeled as
piece-wise constant with a restricted number of distinct albedo values. We show
that under ideal conditions, the shape of a non-degenerate local constant
albedo surface patch can theoretically be recovered exactly. Moreover, we
present a practical and efficient algorithm that uses this model to robustly
recover shape from real images. Our method first reasons about shape locally in
a dense set of patches in the observed image, producing shape distributions for
every patch. These local distributions are then combined to produce a single
consistent surface normal map. We demonstrate the efficacy of the approach
through experiments on both synthetic renderings as well as real captured
images.


title:
Amplitude mode oscillations in pump-probe photoemission spectra from a
  d-wave superconductor

abstract:
  Recent developments in the techniques of ultrafast pump-probe photoemission
have made possible the search for collective modes in strongly correlated
systems out of equilibrium. Including inelastic scattering processes and a
retarded interaction, we simulate time- and angle- resolved photoemission
spectroscopy (trARPES) to study the amplitude mode of a d-wave superconductor,
a collective mode excited through the nonlinear light-matter coupling to the
pump pulse. We find that the amplitude mode oscillations of the d-wave order
parameter occur in phase at a single frequency that is twice the
quasi-steady-state maximum gap size after pumping. We comment on the necessary
conditions for detecting the amplitude mode in trARPES experiments.


title: Hubble trouble or Hubble bubble?

abstract:
  The recent analysis of low-redshift supernovae (SN) has increased the
apparent tension between the value of $H_0$ estimated from low and high
redshift observations such as the cosmic microwave background (CMB) radiation.
At the same time other observations have provided evidence of the existence of
local radial inhomogeneities extending in different directions up to a redshift
of about $0.07$. About $40\%$ of the Cepheids used for SN calibration are
directly affected because are located along the directions of these
inhomogeneities. We derive a new simple formula relating directly the
luminosity distance to the monopole of the density contrast, which does not
involve any metric perturbation. We then use it to develop a new inversion
method to reconstruct the monopole of the density field from the deviations of
the redshift uncorrected observed luminosity distance respect to the $\Lambda
CDM$ prediction based on cosmological parameters obtained from large scale
observations.
  The inversion method confirms the existence of inhomogeneities whose effects
were not previously taken into account because the $2M++$ density field maps
used to obtain the peculiar velocity for redshift correction were for $z\leq
0.06$, which is not a sufficiently large scale to detect the presence of
inhomogeneities extending up to $z=0.07$. The inhomogeneity does not affect the
high redshift luminosity distance because the volume averaged density contrast
tends to zero asymptotically, making the value of $H_0^{CMB}$ obtained from CMB
observations insensitive to any local structure. The inversion method can
provide a unique tool to reconstruct the density field at high redshift where
only SN data is available, and in particular to normalize correctly the density
field respect to the average large scale density of the Universe.


title:
Recent progress in the description of positron scattering from atoms
  using the Convergent Close-Coupling Theory

abstract:
  Much progress in the theory of positron scattering on atoms has been made in
the ten years since the review of Surko, Gribakin and Buckman [J. Phys. B 38,
R57 (2005)]. We review this progress for few-electron targets with a particular
emphasis on the two-centre convergent close-coupling and other theories which
explicitly treat positronium (Ps) formation. While substantial progress has
been made for Ps formation in positron scattering on few-electron targets,
considerable theoretical development is still required for multielectron atomic
and molecular targets.


title: Left dihedral codes over Galois rings ${\rm GR}(p^2,m)$

abstract:
  Let $D_{2n}=\langle x,y\mid x^n=1, y^2=1, yxy=x^{-1}\rangle$ be a dihedral
group, and $R={\rm GR}(p^2,m)$ be a Galois ring of characteristic $p^2$ and
cardinality $p^{2m}$ where $p$ is a prime. Left ideals of the group ring
$R[D_{2n}]$ are called left dihedral codes over $R$ of length $2n$, and
abbreviated as left $D_{2n}$-codes over $R$. Let ${\rm gcd}(n,p)=1$ in this
paper. Then any left $D_{2n}$-code over $R$ is uniquely decomposed into a
direct sum of concatenated codes with inner codes ${\cal A}_i$ and outer codes
$C_i$, where ${\cal A}_i$ is a cyclic code over $R$ of length $n$ and $C_i$ is
a skew cyclic code of length $2$ over an extension Galois ring or principal
ideal ring of $R$, and a generator matrix and basic parameters for each outer
code $C_i$ is given. Moreover, a formula to count the number of these codes is
obtained, the dual code for each left $D_{2n}$-code is determined and all
self-dual left $D_{2n}$-codes and self-orthogonal left $D_{2n}$-codes over $R$
are presented, respectively.


title: Monotonicity Preserving Transformations of MOT and SEP

abstract:
  Recently, \cite{BeJu16, BeNuTo16} established that optimizers to the
martingale optimal transport problem (MOT) are concentrated on $c$-monotone
sets. In this article we characterize monotonicity preserving transformations
revealing certain symmetries between optimizers of MOT for different cost
functions. Due to the intimate connection of MOT and the Skorokhod embedding
problem (SEP) these transformations are also monotonicity preserving and
disclose symmetries for certain solutions to the optimal SEP. Furthermore, the
SEP picture allows to easily understand the geometry of these transformations
once we have established the SEP counterparts to the known solutions of MOT
based on the monotonicity principle for SEP which in turn allows to directly
read off the structure of the MOT optimizers.


title: Partial Solvers for Parity Games: Effective Polynomial-Time Composition

abstract:
  Partial methods play an important role in formal methods and beyond. Recently
such methods were developed for parity games, where polynomial-time partial
solvers decide the winners of a subset of nodes. We investigate here how
effective polynomial-time partial solvers can be by studying interactions of
partial solvers based on generic composition patterns that preserve
polynomial-time computability. We show that use of such composition patterns
discovers new partial solvers - including those that merge node sets that have
the same but unknown winner - by studying games that composed partial solvers
can neither solve nor simplify. We experimentally validate that this
data-driven approach to refinement leads to polynomial-time partial solvers
that can solve all standard benchmarks of structured games. For one of these
polynomial-time partial solvers not even a sole random game from a few billion
random games of varying configuration was found that it won't solve completely.


title: Relation-Changing Logics as Fragments of Hybrid Logics

abstract:
  Relation-changing modal logics are extensions of the basic modal logic that
allow changes to the accessibility relation of a model during the evaluation of
a formula. In particular, they are equipped with dynamic modalities that are
able to delete, add, and swap edges in the model, both locally and globally. We
provide translations from these logics to hybrid logic along with an
implementation. In general, these logics are undecidable, but we use our
translations to identify decidable fragments. We also compare the expressive
power of relation-changing modal logics with hybrid logics.


title: A Delayed Promotion Policy for Parity Games

abstract:
  Parity games are two-player infinite-duration games on graphs that play a
crucial role in various fields of theoretical computer science. Finding
efficient algorithms to solve these games in practice is widely acknowledged as
a core problem in formal verification, as it leads to efficient solutions of
the model-checking and satisfiability problems of expressive temporal logics,
e.g., the modal muCalculus. Their solution can be reduced to the problem of
identifying sets of positions of the game, called dominions, in each of which a
player can force a win by remaining in the set forever. Recently, a novel
technique to compute dominions, called priority promotion, has been proposed,
which is based on the notions of quasi dominion, a relaxed form of dominion,
and dominion space. The underlying framework is general enough to accommodate
different instantiations of the solution procedure, whose correctness is
ensured by the nature of the space itself. In this paper we propose a new such
instantiation, called delayed promotion, that tries to reduce the possible
exponential behaviours exhibited by the original method in the worst case. The
resulting procedure not only often outperforms the original priority promotion
approach, but so far no exponential worst case is known.


title: Games for Topological Fixpoint Logic

abstract:
  Topological fixpoint logics are a family of logics that admits topological
models and where the fixpoint operators are defined with respect to the
topological interpretations. Here we consider a topological fixpoint logic for
relational structures based on Stone spaces, where the fixpoint operators are
interpreted via clopen sets. We develop a game-theoretic semantics for this
logic. First we introduce games characterising clopen fixpoints of monotone
operators on Stone spaces. These fixpoint games allow us to characterise the
semantics for our topological fixpoint logic using a two-player graph game.
Adequacy of this game is the main result of our paper. Finally, we define
bisimulations for the topological structures under consideration and use our
game semantics to prove that the truth of a formula of our topological fixpoint
logic is bisimulation-invariant.


title:
Stochastic Equilibria under Imprecise Deviations in Terminal-Reward
  Concurrent Games

abstract:
  We study the existence of mixed-strategy equilibria in concurrent games
played on graphs. While existence is guaranteed with safety objectives for each
player, Nash equilibria need not exist when players are given arbitrary
terminal-reward objectives, and their existence is undecidable with qualitative
reachability objectives (and only three players). However, these results rely
on the fact that the players can enforce infinite plays while trying to improve
their payoffs. In this paper, we introduce a relaxed notion of equilibria,
where deviations are imprecise. We prove that contrary to Nash equilibria, such
(stationary) equilibria always exist, and we develop a PSPACE algorithm to
compute one.


title:
Model Checking the Logic of Allen's Relations Meets and Started-by is
  $P^NP$-Complete

abstract:
  In the plethora of fragments of Halpern and Shoham's modal logic of time
intervals (HS), the logic AB of Allen's relations Meets and Started-by is at a
central position. Statements that may be true at certain intervals, but at no
sub-interval of them, such as accomplishments, as well as metric constraints
about the length of intervals, that force, for instance, an interval to be at
least (resp., at most, exactly) k points long, can be expressed in AB.
Moreover, over the linear order of the natural numbers N, it subsumes the
(point-based) logic LTL, as it can easily encode the next and until modalities.
Finally, it is expressive enough to capture the {\omega}-regular languages,
that is, for each {\omega}-regular expression R there exists an AB formula
{\phi} such that the language defined by R coincides with the set of models of
{\phi} over N. It has been shown that the satisfiability problem for AB over N
is EXPSPACE-complete. Here we prove that, under the homogeneity assumption, its
model checking problem is {\Delta}^p_2 = P^NP-complete (for the sake of
comparison, the model checking problem for full HS is EXPSPACE-hard, and the
only known decision procedure is nonelementary). Moreover, we show that the
modality for the Allen relation Met-by can be added to AB at no extra cost
(AA'B is P^NP-complete as well).


title: On the Expressive Power of Sub-Propositional Fragments of Modal Logic

abstract:
  Modal logic is a paradigm for several useful and applicable formal systems in
computer science. It generally retains the low complexity of classical
propositional logic, but notable exceptions exist in the domains of
description, temporal, and spatial logic, where the most expressive formalisms
have a very high complexity or are even undecidable. In search of
computationally well-behaved fragments, clausal forms and other
sub-propositional restrictions of temporal and description logics have been
recently studied. This renewed interest on sub-propositional logics, which
mainly focus on the complexity of the various fragments, raise natural
questions on their the relative expressive power, which we try to answer here
for the basic multi-modal logic Kn. We consider the Horn and the Krom
restrictions, as well as the combined restriction (known as the core fragment)
of modal logic, and, orthogonally, the fragments that emerge by disallowing
boxes or diamonds from positive literals. We study the problem in a very
general setting, to ease transferring our results to other meaningful cases.


title: Alternation Is Strict For Higher-Order Modal Fixpoint Logic

abstract:
  We study the expressive power of Alternating Parity Krivine Automata (APKA),
which provide operational semantics to Higher-Order Modal Fixpoint Logic (HFL).
APKA consist of ordinary parity automata extended by a variation of the Krivine
Abstract Machine. We show that the number and parity of priorities available to
an APKA form a proper hierarchy of expressive power as in the modal
mu-calculus. This also induces a strict alternation hierarchy on HFL. The proof
follows Arnold's (1999) encoding of runs into trees and subsequent use of the
Banach Fixpoint Theorem.


title: A Canonical Model Construction for Iteration-Free PDL with Intersection

abstract:
  We study the axiomatisability of the iteration-free fragment of Propositional
Dynamic Logic with Intersection and Tests. The combination of program
composition, intersection and tests makes its proof-theory rather difficult. We
develop a normal form for formulae which minimises the interaction between
these operators, as well as a refined canonical model construction. From these
we derive an axiom system and a proof of its strong completeness.


title: Weighted Linear Dynamic Logic

abstract:
  We introduce a weighted linear dynamic logic (weighted LDL for short) and
show the expressive equivalence of its formulas to weighted rational
expressions. This adds a new characterization for recognizable series to the
fundamental Sch\"utzenberger theorem. Surprisingly, the equivalence does not
require any restriction to our weighted LDL. Our results hold over arbitrary
(resp. totally complete) semirings for finite (resp. infinite) words. As a
consequence, the equivalence problem for weighted LDL formulas over fields is
decidable in doubly exponential time. In contrast to classical logics, we show
that our weighted LDL is expressively incomparable to weighted LTL for finite
words. We determine a fragment of the weighted LTL such that series over finite
and infinite words definable by LTL formulas in this fragment are definable
also by weighted LDL formulas.


title: Cycle Detection in Computation Tree Logic

abstract:
  Temporal logic is a very powerful formalism deeply investigated and used in
formal system design and verification. Its application usually reduces to
solving specific decision problems such as model checking and satisfiability.
In these kind of problems, the solution often requires detecting some specific
properties over cycles. For instance, this happens when using classic
techniques based on automata, game-theory, SCC decomposition, and the like.
Surprisingly, no temporal logics have been considered so far with the explicit
ability of talking about cycles.
  In this paper we introduce Cycle-CTL*, an extension of the classical
branching-time temporal logic CTL* along with cycle quantifications in order to
predicate over cycles. This logic turns out to be very expressive. Indeed, we
prove that it strictly extends CTL* and is orthogonal to mu-calculus. We also
give an evidence of its usefulness by providing few examples involving
non-regular properties.
  We investigate the model checking problem for Cycle-CTL* and show that it is
PSPACE-Complete as for CTL*. We also study the satisfiability problem for the
existential-cycle fragment of the logic and show that it is solvable in
2ExpTime. This result makes use of an automata-theoretic approach along with
novel ad-hoc definitions of bisimulation and tree-like unwinding.


title: Bounded-oscillation Pushdown Automata

abstract:
  We present an underapproximation for context-free languages by filtering out
runs of the underlying pushdown automaton depending on how the stack height
evolves over time. In particular, we assign to each run a number quantifying
the oscillating behavior of the stack along the run. We study languages
accepted by pushdown automata restricted to k-oscillating runs. We relate
oscillation on pushdown automata with a counterpart restriction on context-free
grammars. We also provide a way to filter all but the k-oscillating runs from a
given PDA by annotating stack symbols with information about the oscillation.
Finally, we study closure properties of the defined class of languages and the
complexity of the k-emptiness problem asking, given a pushdown automaton P and
k >= 0, whether P has a k-oscillating run. We show that, when k is not part of
the input, the k-emptiness problem is NLOGSPACE-complete.


title: On Quantified Propositional Logics and the Exponential Time Hierarchy

abstract:
  We study quantified propositional logics from the complexity theoretic point
of view. First we introduce alternating dependency quantified boolean formulae
(ADQBF) which generalize both quantified and dependency quantified boolean
formulae. We show that the truth evaluation for ADQBF is
AEXPTIME(poly)-complete. We also identify fragments for which the problem is
complete for the levels of the exponential hierarchy. Second we study
propositional team-based logics. We show that DQBF formulae correspond
naturally to quantified propositional dependence logic and present a general
NEXPTIME upper bound for quantified propositional logic with a large class of
generalized dependence atoms. Moreover we show AEXPTIME(poly)-completeness for
extensions of propositional team logic with generalized dependence atoms.


title: Multi-Buffer Simulations for Trace Language Inclusion

abstract:
  We consider simulation games played between Spoiler and Duplicator on two
B\"uchi automata in which the choices made by Spoiler can be buffered by
Duplicator in several buffers before she executes them on her structure. We
show that the simulation games are useful to approximate the inclusion of trace
closures of languages accepted by finite-state automata, which is known to be
undecidable. We study the decidability and complexity and show that the game
with bounded buffers can be decided in polynomial time, whereas the game with
one unbounded and one bounded buffer is highly undecidable. We also show some
sufficient conditions on the automata for Duplicator to win the game (with
unbounded buffers).


title:
A Semi-Potential for Finite and Infinite Sequential Games (Extended
  Abstract)

abstract:
  We consider a dynamical approach to sequential games. By restricting the
convertibility relation over strategy profiles, we obtain a semi-potential (in
the sense of Kukushkin), and we show that in finite games the corresponding
restriction of better-response dynamics will converge to a Nash equilibrium in
quadratic time. Convergence happens on a per-player basis, and even in the
presence of players with cyclic preferences, the players with acyclic
preferences will stabilize. Thus, we obtain a candidate notion for rationality
in the presence of irrational agents. Moreover, the restriction of
convertibility can be justified by a conservative updating of beliefs about the
other players strategies.
  For infinite sequential games we can retain convergence to a Nash equilibrium
(in some sense), if the preferences are given by continuous payoff functions;
or obtain a transfinite convergence if the outcome sets of the game are
Delta^0_2 sets.


title: Certification of Prefixed Tableau Proofs for Modal Logic

abstract:
  Different theorem provers tend to produce proof objects in different formats
and this is especially the case for modal logics, where several deductive
formalisms (and provers based on them) have been presented. This work falls
within the general project of establishing a common specification language in
order to certify proofs given in a wide range of deductive formalisms. In
particular, by using a translation from the modal language into a first-order
polarized language and a checker whose small kernel is based on a classical
focused sequent calculus, we are able to certify modal proofs given in labeled
sequent calculi, prefixed tableaux and free-variable prefixed tableaux. We
describe the general method for the logic K, present its implementation in a
prolog-like language, provide some examples and discuss how to extend the
approach to other normal modal logics


title:
The Almost Equivalence by Asymptotic Probabilities for Regular Languages
  and Its Computational Complexities

abstract:
  We introduce p-equivalence by asymptotic probabilities, which is a weak
almost-equivalence based on zero-one laws in finite model theory. In this
paper, we consider the computational complexities of p-equivalence problems for
regular languages and provide the following details. First, we give an
robustness of p-equivalence and a logical characterization for p-equivalence.
The characterization is useful to generate some algorithms for p-equivalence
problems by coupling with standard results from descriptive complexity. Second,
we give the computational complexities for the p-equivalence problems by the
logical characterization. The computational complexities are the same as for
the (fully) equivalence problems. Finally, we apply the proofs for
p-equivalence to some generalized equivalences.


title: A New Rule for LTL Tableaux

abstract:
  Propositional linear time temporal logic (LTL) is the standard temporal logic
for computing applications and many reasoning techniques and tools have been
developed for it. Tableaux for deciding satisfiability have existed since the
1980s. However, the tableaux for this logic do not look like traditional
tree-shaped tableau systems and their processing is often quite complicated.
  In this paper, we introduce a novel style of tableau rule which supports a
new simple traditional-style tree-shaped tableau for LTL. We prove that it is
sound and complete. As well as being simple to understand, to introduce to
students and to use, it is also simple to implement and is competitive against
state of the art systems. It is particularly suitable for parallel
implementations.


title: A Machine Learning Nowcasting Method based on Real-time Reanalysis Data

abstract:
  Despite marked progress over the past several decades, convective storm
nowcasting remains a challenge because most nowcasting systems are based on
linear extrapolation of radar reflectivity without much consideration for other
meteorological fields. The variational Doppler radar analysis system (VDRAS) is
an advanced convective-scale analysis system capable of providing analysis of
3-D wind, temperature, and humidity by assimilating Doppler radar observations.
Although potentially useful, it is still an open question as to how to use
these fields to improve nowcasting. In this study, we present results from our
first attempt at developing a Support Vector Machine (SVM) Box-based nOWcasting
(SBOW) method under the machine learning framework using VDRAS analysis data.
The key design points of SBOW are as follows: 1) The study domain is divided
into many position-fixed small boxes and the nowcasting problem is transformed
into one question, i.e., will a radar echo > 35 dBZ appear in a box in 30
minutes? 2) Box-based temporal and spatial features, which include time trends
and surrounding environmental information, are elaborately constructed, and 3)
The box-based constructed features are used to first train the SVM classifier,
and then the trained classifier is used to make predictions. Compared with
complicated and expensive expert systems, the above design of SBOW allows the
system to be small, compact, straightforward, and easy to maintain and expand
at low cost. The experimental results show that, although no complicated
tracking algorithm is used, SBOW can predict the storm movement trend and storm
growth with reasonable skill.

categories: physics.ao-ph cs.CV physics.geo-ph stat.AP


title:
Tracking Tensor Subspaces with Informative Random Sampling for Real-Time
  MR Imaging

abstract:
  Magnetic resonance imaging (MRI) nowadays serves as an important modality for
diagnostic and therapeutic guidance in clinics. However, the {\it slow
acquisition} process, the dynamic deformation of organs, as well as the need
for {\it real-time} reconstruction, pose major challenges toward obtaining
artifact-free images. To cope with these challenges, the present paper
advocates a novel subspace learning framework that permeates benefits from
parallel factor (PARAFAC) decomposition of tensors (multiway data) to low-rank
modeling of temporal sequence of images. Treating images as multiway data
arrays, the novel method preserves spatial structures and unravels the latent
correlations across various dimensions by means of the tensor subspace.
Leveraging the spatio-temporal correlation of images, Tykhonov regularization
is adopted as a rank surrogate for a least-squares optimization program.
Alteranating majorization minimization is adopted to develop online algorithms
that recursively procure the reconstruction upon arrival of a new undersampled
$k$-space frame. The developed algorithms are {\it provably convergent} and
highly {\it parallelizable} with lightweight FFT tasks per iteration. To
further accelerate the acquisition process, randomized subsampling policies are
devised that leverage intermediate estimates of the tensor subspace, offered by
the online scheme, to {\it randomly} acquire {\it informative} $k$-space
samples. In a nutshell, the novel approach enables tracking motion dynamics
under low acquisition rates `on the fly.' GPU-based tests with real {\it in
vivo} MRI datasets of cardiac cine images corroborate the merits of the novel
approach relative to state-of-the-art alternatives.


title: A Liouville Theorem for the Higher Order Fractional Laplacian

abstract:
  We deal with the higher-order fractional Laplacians by two methods: the
integral method and the system method. The former depends on the integral
equation equivalent to the differential equation.
  The latter works directly on the differential equations. We first derive
nonexistence of positive solutions, often known as the Liouville type theorem,
for the integral and differential equations. Then through an delicate
iteration, we show symmetry for positive solutions.


title: The Inverse Gamma Distribution and Benford's Law

abstract:
  According to Benford's Law, many data sets have a bias towards lower leading
digits (about $30\%$ are $1$'s). The applications of Benford's Law vary: from
detecting tax, voter and image fraud to determining the possibility of
match-fixing in competitive sports. There are many common distributions that
exhibit such bias, i.e. they are almost Benford. These include the exponential
and the Weibull distributions. Motivated by these examples and the fact that
the underlying distribution of factors in protein structure follows an inverse
gamma distribution, we determine the closeness of this distribution to a
Benford distribution as its parameters change.


title: Sharp decouplings for three dimensional manifolds in $\mathbb{R}^5$

abstract:
  We prove a sharp decoupling for a class of three dimensional manifolds in
$\mathbb{R}^5$.


title:
A joint-optimization NSAF algorithm based on the first-order Markov
  model

abstract:
  Recently, the normalized subband adaptive filter (NSAF) algorithm has
attracted much attention for handling the colored input signals. Based on the
first-order Markov model of the optimal tap-weight vector, this paper provides
a convergence analysis of the standard NSAF. Following the analysis, both the
step size and the regularization parameter in the NSAF are jointly optimized in
such a way that minimizes the mean square deviation. The resulting
joint-optimization step size and regularization parameter (JOSR-NSAF) algorithm
achieves a good tradeoff between fast convergence rate and low steady-state
error. Simulation results in the context of acoustic echo cancellation
demonstrate good features of the proposed algorithm.


title: Douglas metrics of (\alpha,\beta) type

abstract:
  In this paper, the Douglas curvature of (\alpha,\beta)-metrics, a special
class of Finsler metrics defined by a Riemannian metric \alpha and a 1-form
\beta, is studied. These metrics with vanishing Douglas curvature in dimension
n\geq3 are classified by using a new class of metrical deformations called
\beta-deformations. The result shows that conformal 1-forms of Riemannian
metrics play a key role, and an effective way to construct such 1-forms is
provided also by \beta-deformations.


title:
The global attractor for the 3-D viscous primitive equations of
  large-scale moist atmosphere

abstract:
  Absorbing ball in $H^{1}(\mho)$ is obtained for the strong solution to the
three dimensional viscous moist primitive equations under the natural
assumption $Q_{1},Q_{2}\in L^{2}(\mho)$ which is weaker than the assumption
$Q_{1},Q_{2}\in H^{1}(\mho)$ in $\cite{GH2}$. In view of the structure of the
manifold and the special geometry involved with vertical velocity, the
continuity of the strong solution in $H^{1}(\mho)$ is established with respect
to time and initial data. To obtain the existence of the global attractor for
the moist primitive equations, the common method is to obtain the absorbing
ball in $H^{2}(\mho)$ for the strong solution to the equations. But it is
difficult due to the complex structure of the moist primitive equations. To
overcome the difficulty, we try to use Aubin-Lions lemma and the continuous
property of the strong solutions to the moist primitive equations to prove the
the existence of the global attractor which improves the result, the existence
of weak attractor, in $\cite{GH2}$.


title: Proposal for an Extended Run of T2K to $20\times10^{21}$ POT

abstract:
  Recent measurements by the T2K neutrino oscillation experiment indicate that
CP violation in neutrino mixing may be observed in the future by long-baseline
neutrino oscillation experiments. We propose an extension to the currently
approved T2K running from $7.8\times 10^{21}~\mbox{POT}$ to $20\times
10^{21}~\mbox{POT}$, aiming at initial observation of CP violation with
3$\,\sigma$ or higher significance for the case of maximum CP violation. The
program also contains a measurement of mixing parameters, $\theta_{23}$ and
$\Delta m^2_{32}$, with a precision of 1.7$^\circ$ or better and 1%,
respectively. With accelerator and beamline upgrades, as well as analysis
improvements, this program would occur before the next generation of
long-baseline neutrino oscillation experiments that are expected to start
operation in 2026.


title: Understanding Convolutional Neural Networks with A Mathematical Model

abstract:
  This work attempts to address two fundamental questions about the structure
of the convolutional neural networks (CNN): 1) why a non-linear activation
function is essential at the filter output of every convolutional layer? 2)
what is the advantage of the two-layer cascade system over the one-layer
system? A mathematical model called the "REctified-COrrelations on a Sphere"
(RECOS) is proposed to answer these two questions. After the CNN training
process, the converged filter weights define a set of anchor vectors in the
RECOS model. Anchor vectors represent the frequently occurring patterns (or the
spectral components). The necessity of rectification is explained using the
RECOS model. Then, the behavior of a two-layer RECOS system is analyzed and
compared with its one-layer counterpart. The LeNet-5 and the MNIST dataset are
used to illustrate discussion points. Finally, the RECOS model is generalized
to a multi-layer system with the AlexNet as an example.
  Keywords: Convolutional Neural Network (CNN), Nonlinear Activation, RECOS
Model, Rectified Linear Unit (ReLU), MNIST Dataset.


title: A Note on Rickart Modules

abstract:
  We study the notion of Rickart property in a general module theoretic setting
as a generalization to the concept of Baer modules and right Rickart rings. A
module $M_{R}$ is called Rickart if the right annihilator in $M_{R}$ of each
left principal ideal of $End_{R}(M)$ is generated by an idempotent.
Characterizations of Rickart modules are given. We give sufficient conditions
for direct sums of Rickart modules to be Rickart. We extend some useful results
of right Rickart rings to the theory of Rickart modules.


title:
Design of a High-Performance High-Pass Generalized Integrator Based
  Single-Phase PLL

abstract:
  Grid-interactive power converters are normally synchronized to the grid using
phase-locked loops (PLLs). The performance of the PLLs is affected by the
non-ideal conditions in the sensed grid voltage such as harmonics, frequency
deviations and dc offsets in single-phase systems. In this paper, a
single-phase PLL is presented to mitigate the effects of these non-idealities.
This PLL is based on the popular second order generalized integrator (SOGI)
structure. The SOGI structure is modified to eliminate of the effects of input
dc offsets. The resulting SOGI structure has a high-pass filtering property.
Hence, this PLL is termed as high-pass generalized integrator based PLL
(HGI-PLL). It has fixed parameters which reduces the implementation complexity
and aids in the implementation in low-end digital controllers. The HGI-PLL is
shown to have least resource utilization among the SOGI based PLLs with dc
cancelling capability. Systematic design methods are evolved leading to the
design that limits the unit vector THD to within 1% for given non-ideal input
conditions in terms of frequency deviation and harmonic distortion. The
proposed designs achieve the fastest transient response. The performance of
this PLL has been verified experimentally. The results are found to agree with
the theoretical prediction.


title: Constructing Frequency Domains on Graphs in Near-Linear Time

abstract:
  Analysis of big data has become an increasingly relevant area of research,
with data often represented on discrete networks both constructed and organic.
While for structured domains, there exist intuitive definitions of signals and
frequencies, the definitions are much less obvious for data sets associated
with a given network. Often, the eigenvectors of an induced graph Laplacian are
used to construct an orthogonal set of low-frequency vectors. For larger
graphs, however, the computational cost of creating such structures becomes
untenable, and the quality of the approximation is adequate only for signals
near the span of the set. We propose a construction of a full basis of
frequencies with computational complexity that is near-linear in time and
linear in storage. Using this frequency domain, we can compress data sets on
unstructured graphs more robustly and accurately than spectral-based
constructions.


title:
Joint Gender Classification and Age Estimation by Nearly Orthogonalizing
  Their Semantic Spaces

abstract:
  In human face-based biometrics, gender classification and age estimation are
two typical learning tasks. Although a variety of approaches have been proposed
to handle them, just a few of them are solved jointly, even so, these joint
methods do not yet specifically concern the semantic difference between human
gender and age, which is intuitively helpful for joint learning, consequently
leaving us a room of further improving the performance. To this end, in this
work we firstly propose a general learning framework for jointly estimating
human gender and age by specially attempting to formulate such semantic
relationships as a form of near-orthogonality regularization and then
incorporate it into the objective of the joint learning framework. In order to
evaluate the effectiveness of the proposed framework, we exemplify it by
respectively taking the widely used binary-class SVM for gender classification,
and two threshold-based ordinal regression methods (i.e., the discriminant
learning for ordinal regression and support vector ordinal regression) for age
estimation, and crucially coupling both through the proposed semantic
formulation. Moreover, we develop its kernelized nonlinear counterpart by
deriving a representer theorem for the joint learning strategy. Finally,
through extensive experiments on three aging datasets FG-NET, Morph Album I and
Morph Album II, we demonstrate the effectiveness and superiority of the
proposed joint learning strategy.


title: Network learning via multi-agent inverse transportation problems

abstract:
  Despite the ubiquity of transportation data, methods to infer the state
parameters of a network either ignore sensitivity of route decisions, require
route enumeration for parameterizing descriptive models of route selection, or
require complex bilevel models of route assignment behavior. These limitations
prevent modelers from fully exploiting ubiquitous data in monitoring
transportation networks. Inverse optimization methods that capture network
route choice behavior can address this gap, but they are designed to take
observations of the same model to learn the parameters of that model, which is
statistically inefficient (e.g. requires estimating population route and link
flows). New inverse optimization models and supporting algorithms are proposed
to learn the parameters of heterogeneous travelers' route behavior to infer
shared network state parameters (e.g. link capacity dual prices). The inferred
values are consistent with observations of each agent's optimization behavior.
We prove that the method can obtain unique dual prices for a network shared by
these agents in polynomial time. Four experiments are conducted. The first one,
conducted on a 4-node network, verifies the methodology to obtain heterogeneous
link cost parameters even when multinomial or mixed logit models would not be
meaningfully estimated. The second is a parameter recovery test on the
Nguyen-Dupuis network that shows that unique latent link capacity dual prices
can be inferred using the proposed method. The third test on the same network
demonstrates how a monitoring system in an online learning environment can be
designed using this method. The last test demonstrates this learning on real
data obtained from a freeway network in Queens, New York, using only real-time
Google Maps queries.


title:
Divergent trajectories under diagonal geodesic flow and splitting of
  discrete subgroups of $\mathrm{SO}(n,1) \times \mathrm{SO}(n,1)$

abstract:
  Let $H = \mathrm{SO}(n,1)$ and $A = \{a(t): t \in \mathbb{R}\}$ be a maximal
$\mathbb{R}$-split Cartan subgroup of $H$. Let $\Gamma \subset H \times H$ be a
nonuniform lattice in $H \times H$ and $X_{\Gamma} : = H \times H/ \Gamma$. Let
$A_2 : = \{ a_2(t):=a(t) \times a(t) : t \in \mathbb{R}\} \subset A\times A$ on
$X_{\Gamma}$ and $\mathcal{D}_{\Gamma}\subset X_{\Gamma}$ denote the collection
of points $x \in X_{\Gamma}$ such that $a_2(t)x$ diverges as $t \rightarrow
+\infty$. In this note, we will show that if the Hausdorff dimension of
$\mathcal{D}_{\Gamma}$ is greater than $\dim (H\times H) - 2(n-1)$, then
$\Gamma $ is essentially split, namely, it contains a subgroup of finite index
of form $\Gamma_1 \times \Gamma_2 $, where $\Gamma_1$ and $\Gamma_2$ are both
lattices in $H$.


title: Classical capacity of phase-sensitive Gaussian quantum channels

abstract:
  The full solution of the optimization problem giving the Gaussian capacity of
the single-mode fiducial Gaussian quantum channel is provided. Since it was
shown that the Gaussian capacity of an arbitrary (phase-sensitive or
insensitive) single-mode Gaussian quantum channel is equal to the Gaussian
capacity of this fiducial channel, the solution presented in this work can be
regarded as universal. The analytical study of this solution, below and above
the energy threshold, shows that the dependence of the Gaussian capacity on the
environment noise squeezing is not monotonic. In particular, the capacity may
have a saddle point, one or two extrema at finite squeezing, or be a
monotonically increasing function of the squeezing parameter. The exact
dependence is defined by the determinant of the noise covariance matrix and by
the transmissivity (or gain) of the fiducial Gaussian channel.


title: Private Topic Modeling

abstract:
  We develop a privatised stochastic variational inference method for Latent
Dirichlet Allocation (LDA). The iterative nature of stochastic variational
inference presents challenges: multiple iterations are required to obtain
accurate posterior distributions, yet each iteration increases the amount of
noise that must be added to achieve a reasonable degree of privacy. We propose
a practical algorithm that overcomes this challenge by combining: (1) an
improved composition method for differential privacy, called the moments
accountant, which provides a tight bound on the privacy cost of multiple
variational inference iterations and thus significantly decreases the amount of
additive noise; and (2) privacy amplification resulting from subsampling of
large-scale data. Focusing on conjugate exponential family models, in our
private variational inference, all the posterior distributions will be
privatised by simply perturbing expected sufficient statistics. Using Wikipedia
data, we illustrate the effectiveness of our algorithm for large-scale data.


title:
The Galaxy Cluster Merger Catalog: An Online Repository of Mock
  Observations from Simulated Galaxy Cluster Mergers

abstract:
  We present the "Galaxy Cluster Merger Catalog." This catalog provides an
extensive suite of mock observations and related data for N-body and
hydrodynamical simulations of galaxy cluster mergers and clusters from
cosmological simulations. These mock observations consist of projections of a
number of important observable quantities in several different wavebands as
well as along different lines of sight through each simulation domain. The web
interface to the catalog consists of easily browseable images over epoch and
projection direction, as well as download links for the raw data and a JS9
interface for interactive data exploration. The data is presented within a
consistent format so that comparison between simulations is straightforward.
All of the data products are provided in the standard FITS file format. Data is
being stored on the yt Hub (http://hub.yt), which allows for remote access and
analysis using a Jupyter notebook server. Future versions of the catalog will
include simulations from a number of research groups and a variety of research
topics related to the study of interactions of galaxy clusters with each other
and with their member galaxies. The catalog is located at http://gcmc.hub.yt.


title: Rashba-Edelstein Magnetoresistance in Metallic Heterostructure

abstract:
  We report the observation of magnetoresistance originating from Rashba
spin-orbit coupling (SOC) in a metallic heterostructure: the Rashba-Edelstein
(RE) magnetoresistance. We show that the simultaneous action of the direct and
inverse RE effects in a Bi/Ag/CoFeB trilayer couples current-induced spin
accumulation to the electric resistance. The electric resistance changes with
the magnetic-field angle, reminiscent of the spin Hall magnetoresistance,
despite the fact that bulk SOC is not responsible for the magnetoresistance. We
further found that, even when the magnetization is saturated, the resistance
increases with increasing the magnetic-field strength, which is attributed to
the Hanle magnetoresistance in this system.


title:
Spiral magnetic order, non-uniform states and electron correlations in
  the conducting transition metal systems

abstract:
  The ground-state magnetic phase diagram is calculated within the Hubbard and
$s$-$d$ exchange (Kondo) models for square and simple cubic lattices vs. band
filling and interaction parameter. The difference of the results owing to the
presence of localized moments in the latter model is discussed. We employ a
generalized Hartree-Fock approximation (HFA) to treat commensurate
ferromagnetic (FM), antiferromagnetic (AFM), and incommensurate (spiral)
magnetic phases. The electron correlations are taken into account within the
Hubbard model by using the Kotliar-Ruckenstein slave boson approximation (SBA).
The main advantage of this approach is a correct qualitative description of the
paramagnetic phase: its energy becomes considerably lower as compared with HFA,
and the gain in the energy of magnetic phases is substantially reduced.


title: On the sections of universal hyperelliptic curves

abstract:
  In this paper, we will give an algebraic proof for determining the sections
for the universal pointed hyperelliptic curves, when $g\geq 3$ and the image of
the $\ell$-adic cyclotomic character $G_k\to \Z^\times$ is infinite.
Furthermore, we will study the nonabelian phenomena associated to the universal
hyperelliptic curves. For example, we will show that the section conjecture
holds for the universal hyperelliptic curve without marked points and the
unipotent analogue of the conjecture holds for the pointed case. This work is
an extension of Hain's original work to the hyperelliptic case.


title: Asymptotics of determinants of discrete Schr\"odinger operators

abstract:
  We consider the asymptotics of the determinants of large discrete
Schr\"odinger operators, i.e. "discrete Laplacian $+$ diagonal": \[T_n(f) =
-[\delta_{j,j+1}+\delta_{j+1,j}] + \mbox{diag}\left(f\left(\frac{1}{n}\right),
f\left(\frac{2}{n}\right),\dots, f\left(\frac{n}{n}\right)\right) \] We extend
a result of M. Kac, who found a formula for \[\lim_{n\rightarrow\infty}
\frac{\det(T_n(f))}{G(f)^n} \] in terms of the values of $f$, where $G(f)$ is a
constant. We extend this result in two ways: First, we consider shifting the
index: Let \[T_n(f;\varepsilon) = -[\delta_{j,j+1}+\delta_{j+1,j}] +
\mbox{diag}\left(f\left(\frac{\varepsilon}{n}\right), f\left(\frac{1+
\varepsilon}{n}\right), \dots, f\left(\frac{n-1+ \varepsilon}{n}\right)\right)
\] We calculate $\lim \det T_n(f;\varepsilon)/G(f)^n$ and show that this limit
can be any positive number by shifting $\varepsilon$, even though the
asymptotic eigenvalue distribution of $T_n(f;\varepsilon)$ does not depend on
$\varepsilon$. Secondly, we derive a formula for the asymptotics of $\det
T_n(f)/G(f)^n$ when $f$ has jump discontinuities. In this case the asymptotics
depend on the fractional part of $c n$, where $c$ is a point of discontinuity.


title: A center manifold reduction of the Kuramoto-Daido model with a phase-lag

abstract:
  A bifurcation from the incoherent state to the partially synchronized state
of the Kuramoto-Daido model with the coupling function $f(\theta ) = \sin
(\theta +\alpha _1)
  + h\sin 2(\theta +\alpha _2)$ is investigated based on the generalized
spectral theory and the center manifold reduction. The dynamical system of the
order parameter on a center manifold is derived under the assumption that there
exists a center manifold on the dual space of a certain test function space. It
is shown that the incoherent state loses the stability at a critical coupling
strength $K=K_c$, and a stable rotating partially synchronized state appears
for $K>K_c$. The velocity of the rotating state is different from the average
of natural frequencies of oscillators when $\alpha _1 \neq 0$.


title: Degree Growth of Rational Maps Induced from Algebraic Structures

abstract:
  For a finite dimensional vector space equipped with a $\mathbb C$-algebra
structure, one can define rational maps using the algebraic structure. In this
paper, we describe the growth of the degree sequences for this type of rational
maps.


title:
Revised Stellar Properties of Kepler Targets for the Q1-17 (DR25)
  Transit Detection Run

abstract:
  The determination of exoplanet properties and occurrence rates using Kepler
data critically depends on our knowledge of the fundamental properties (such as
temperature, radius and mass) of the observed stars. We present revised stellar
properties for 197,096 Kepler targets observed between Quarters 1-17 (Q1-17),
which were used for the final transiting planet search run by the Kepler
Mission (Data Release 25, DR25). Similar to the Q1--16 catalog by Huber et al.
the classifications are based on conditioning published atmospheric parameters
on a grid of Dartmouth isochrones, with significant improvements in the adopted
methodology and over 29,000 new sources for temperatures, surface gravities or
metallicities. In addition to fundamental stellar properties the new catalog
also includes distances and extinctions, and we provide posterior samples for
each stellar parameter of each star. Typical uncertainties are ~27% in radius,
~17% in mass, and ~51% in density, which is somewhat smaller than previous
catalogs due to the larger number of improved logg constraints and the
inclusion of isochrone weighting when deriving stellar posterior distributions.
On average, the catalog includes a significantly larger number of evolved
solar-type stars, with an increase of 43.5% in the number of subgiants. We
discuss the overall changes of radii and masses of Kepler targets as a function
of spectral type, with particular focus on exoplanet host stars.


title:
Topological superconductivity in an ultrathin, magnetically-doped
  topological insulator proximity coupled to a conventional superconductor

abstract:
  As a promising candidate system to realize topological superconductivity, the
system of a 3D topological insulator (TI) grown on top of the s-wave
superconductor has been extensively studied. To access the topological
superconductivity experimentally, the 3D TI sample must be thin enough to allow
for Cooper pair tunneling to the exposed surface of TI. The use of magnetically
ordered dopants to break time-reversal symmetry may allow the surface of a TI
to host Majorana fermion, which are believed to be a signature of topological
superconductivity. In this work, we study a magnetically-doped thin film
TI-superconductor hybrid systems. Considering the proximity induced order
parameter in thin film of TI, we analyze the gap closing points of the
Hamiltonian and draw the phase diagram as a function of relevant parameters:
the hybridization gap, Zeeman energy, and chemical potential of the TI system.
Our findings provide a useful guide in choosing relevant parameters to
facilitate the observation of topological superconductivity in thin film
TI-superconductor hybrid systems. In addition, we further perform numerical
analysis on a TI proximity coupled to a s-wave superconductor and find that,
due to the spin-momentum locked nature of the surface states in TI, the induced
s-wave order parameter of the surface states persists even at large magnitude
of the Zeeman energy.


title: Unconditional Stability for Multistep ImEx Schemes: Theory

abstract:
  This paper presents a new class of high order linear ImEx multistep schemes
with large regions of unconditional stability. Unconditional stability is a
desirable property of a time stepping scheme, as it allows the choice of time
step solely based on accuracy considerations. Of particular interest are
problems for which both the implicit and explicit parts of the ImEx splitting
are stiff. Such splittings can arise, for example, in variable-coefficient
problems, or the incompressible Navier-Stokes equations. To characterize the
new ImEx schemes, an unconditional stability region is introduced, which plays
a role analogous to that of the stability region in conventional multistep
methods. Moreover, computable quantities (such as a numerical range) are
provided that guarantee an unconditionally stable scheme for a proposed
implicit-explicit matrix splitting. The new approach is illustrated with
several examples. Coefficients of the new schemes up to fifth order are
provided.