title:
On Low-Space Differentially Private Low-rank Factorization in the
  Spectral Norm

abstract:
  Low-rank factorization is used in many areas of computer science where one
performs spectral analysis on large sensitive data stored in the form of
matrices. In this paper, we study differentially private low-rank factorization
of a matrix with respect to the spectral norm in the turnstile update model. In
this problem, given an input matrix $\mathbf{A} \in \mathbb{R}^{m \times n}$
updated in the turnstile manner and a target rank $k$, the goal is to find two
rank-$k$ orthogonal matrices $\mathbf{U}_k \in \mathbb{R}^{m \times k}$ and
$\mathbf{V}_k \in \mathbb{R}^{n \times k}$, and one positive semidefinite
diagonal matrix $\textbf{\Sigma}_k \in \mathbb{R}^{k \times k}$ such that
$\mathbf{A} \approx \mathbf{U}_k \textbf{\Sigma}_k \mathbf{V}_k^\mathsf{T}$
with respect to the spectral norm.
  Our main contributions are two computationally efficient and sub-linear space
algorithms for computing a differentially private low-rank factorization. We
consider two levels of privacy. In the first level of privacy, we consider two
matrices neighboring if their difference has a Frobenius norm at most $1$. In
the second level of privacy, we consider two matrices as neighboring if their
difference can be represented as an outer product of two unit vectors. Both
these privacy levels are stronger than those studied in the earlier papers such
as Dwork {\it et al.} (STOC 2014), Hardt and Roth (STOC 2013), and Hardt and
Price (NIPS 2014).
  As a corollary to our results, we get non-private algorithms that compute
low-rank factorization in the turnstile update model with respect to the
spectral norm. We note that, prior to this work, no algorithm that outputs
low-rank factorization with respect to the spectral norm in the turnstile
update model was known; i.e., our algorithm gives the first non-private
low-rank factorization with respect to the spectral norm in the turnstile
update mode.


title:
Canonical symplectic structure and structure-preserving geometric
  algorithms for Schr\"odinger-Maxwell systems

abstract:
  An infinite dimensional canonical symplectic structure and
structure-preserving geometric algorithms are developed for the photon-matter
interactions described by the Schr\"odinger-Maxwell equations. The algorithms
preserve the symplectic structure of the system and the unitary nature of the
wavefunctions, and bound the energy error of the simulation for all time-steps.
This new numerical capability enables us to carry out first-principle based
simulation study of important photon-matter interactions, such as the high
harmonic generation and stabilization of ionization, with long-term accuracy
and fidelity.

categories: quant-ph math.SG physics.atom-ph physics.plasm-ph


title:
Dynamical System Modeling to Simulate Donor T Cell Response to Whole
  Exome Sequencing-Derived Recipient Peptides: Understanding Randomness in
  Clinical Outcomes Following Stem Cell Transplantation

abstract:
  Alloreactivity following stem cell transplantation (SCT) is difficult to
predict in patients undergoing transplantation from HLA matched donors. In this
study we performed whole exome sequencing of SCT donor-recipient pairs (DRP).
This allowed determination of entire library of alloreactive peptide sequences
which would bind HLA class I molecules in each DRP. Utilizing the HLA binding
affinity (IC50) and tissue expression levels of the parent proteins, an
aggregate donor T cell response to the recipient alloreactive peptides was
calculated using a vector-operator dynamical system model. Marked variability
in the simulated CD8+ T cell responses was observed in all the donor recipient
pairs.


title:
Orbital-driven Mottness collapse in 1T-TaS2-xSex transition metal
  dichalcogenide

abstract:
  The vicinity of a Mott insulating phase has constantly been a fertile ground
for finding exotic quantum states, most notably the high Tc cuprates and
colossal magnetoresistance manganites. The layered transition metal
dichalcogenide 1T-TaS2 represents another intriguing example, in which the Mott
insulator phase is intimately entangled with a series of complex
charge-density-wave (CDW) orders. More interestingly, it has been recently
found that 1T-TaS2 undergoes a Mott-insulator-to-superconductor transition
induced by high pressure, charge doping, or isovalent substitution. The nature
of the Mott insulator phase and transition mechanism to the conducting state is
still under heated debate. Here, by combining scanning tunneling microscopy
(STM) measurements and first-principles calculations, we investigate the atomic
scale electronic structure of 1T-TaS2 Mott insulator and its evolution to the
metallic state upon isovalent substitution of S with Se. We identify two
distinct types of orbital textures - one localized and the other extended - and
demonstrates that the interplay between them is the key factor that determines
the electronic structure. Especially, we show that the continuous evolution of
the charge gap visualized by STM is due to the immersion of the
localized-orbital-induced Hubbard bands into the extended-orbital-spanned Fermi
sea, featuring a unique evolution from a Mott gap to a charge-transfer gap.
This new mechanism of orbital-driven Mottness collapse revealed here suggests
an interesting route for creating novel electronic state and designing future
electronic devices.


title:
Interaction prediction between groundwater and quarry extension using
  discrete choice models and artificial neural networks

abstract:
  Groundwater and rock are intensively exploited in the world. When a quarry is
deepened the water table of the exploited geological formation might be
reached. A dewatering system is therefore installed so that the quarry
activities can continue, possibly impacting the nearby water catchments. In
order to recommend an adequate feasibility study before deepening a quarry, we
propose two interaction indices between extractive activity and groundwater
resources based on hazard and vulnerability parameters used in the assessment
of natural hazards. The levels of each index (low, medium, high, very high)
correspond to the potential impact of the quarry on the regional hydrogeology.
  The first index is based on a discrete choice modelling methodology while the
second is relying on an artificial neural network. It is shown that these two
complementary approaches (the former being probabilistic while the latter fully
deterministic) are able to predict accurately the level of interaction. Their
use is finally illustrated by their application on the Boverie quarry and the
Tridaine gallery located in Belgium. The indices determine the current
interaction level as well as the one resulting from future quarry extensions.
The results highlight the very high interaction level of the quarry with the
gallery.


title: Searching with Measurement Dependent Noise

abstract:
  Consider a target moving at a constant velocity on a unit-circumference
circle, starting at an arbitrary location. To acquire the target, any region of
the circle can be probed to obtain a noisy measurement of the target's
presence, where the noise level increases with the size of the probed region.
We are interested in the expected time required to find the target to within
some given resolution and error probability. For a known velocity, we
characterize the optimal tradeoff between time and resolution, and show that in
contrast to the well studied case of constant measurement noise, measurement
dependent noise incurs a multiplicative gap in the targeting rate between
adaptive and non-adaptive search strategies. Moreover, our adaptive strategy
attains the optimal rate-reliability tradeoff. We further show that for optimal
non-adaptive search, accounting for an unknown velocity incurs a factor of at
least two in the targeting rate.


title:
Loading of atoms into an optical trap with high initial phase-space
  density

abstract:
  We report a method for loading cold atoms into an optical trap with high
initial phase-space density (PSD). When the trap beam is overlapped with atoms
in optical molasses of optimized parameters including large cooling beam
detuning compared with conventional detuning used for a magneto-optical trap
(MOT), more than $3 \times 10^6$ rubidium atoms with an initial temperature
less than 20 $\mu$K are loaded into a single beam trap. The obtained maximum
initial PSD is estimated to be $1.1 \times 10^{-3}$, which is one or two orders
of magnitude greater than that achieved with the conventional loading into an
optical trap from atoms in a MOT. The proposed method is promising for creating
a quantum gas with a large number of atoms in a short evaporation time.


title: Differential topology of semimetals

abstract:
  The subtle interplay between local and global charges for topological
semimetals exactly parallels that for singular vector fields. Part of this
story is the relationship between cohomological semimetal invariants, Euler
structures, and ambiguities in the torsion of manifolds. Dually, a topological
semimetal can be represented by Euler chains from which its surface Fermi arc
connectivity can be deduced. These dual pictures, and the link to topological
invariants of insulators, are organised using geometric exact sequences. We go
beyond Dirac-type Hamiltonians and introduce new classes of semimetals whose
local charges are subtle Atiyah-Dupont-Thomas invariants globally constrained
by the Kervaire semicharacteristic, leading to the prediction of torsion Fermi
arcs.

categories: math-ph cond-mat.mes-hall hep-th math.DG math.MP


title: Small sets of complementary observables

abstract:
  Two observables are called complementary if preparing a physical object in an
eigenstate of one of them yields a completely random result in a measurement of
the other. We investigate small sets of complementary observables that cannot
be extended by yet another complementary observable. We construct explicit
examples of the unextendible sets up to dimension $16$ and conjecture certain
small sets to be unextendible in higher dimensions. Our constructions provide
three complementary measurements, only one observable away from the ultimate
minimum of two observables in the set. Almost all of our examples in finite
dimension allow to discriminate pure states from some mixed states, and shed
light on the complex topology of the Bloch space of higher-dimensional quantum
systems.


title:
Architectures of Soft Robotic Locomotion Enabled by Simple Mechanical
  Principles

abstract:
  In nature, a variety of limbless locomotion patterns flourish from the small
or basic life form (Escherichia coli, the amoeba, etc.) to the large or
intelligent creatures (e.g., slugs, starfishes, earthworms, octopuses,
jellyfishes, and snakes). Many bioinspired soft robots based on locomotion have
been developed in the past decades. In this work, based on the kinematics and
dynamics of two representative locomotion modes (i.e., worm-like crawling and
snake-like slithering), we propose a broad set of innovative designs for soft
mobile robots through simple mechanical principles. Inspired by and go beyond
existing biological systems, these designs include 1-D (dimensional), 2-D, and
3-D robotic locomotion patterns enabled by simple actuation of continuous
beams. We report herein over 20 locomotion modes achieving various locomotion
functions, including crawling, rising, running, creeping, squirming,
slithering, swimming, jumping, turning, turning over, helix rolling, wheeling,
etc. Some of them are able to reach high speed, high efficiency, and overcome
obstacles. All these locomotion strategies and functions can be integrated into
a simple beam model. The proposed simple and robust models are adaptive for
severe and complex environments. These elegant designs for diverse robotic
locomotion patterns are expected to underpin future deployments of soft robots
and to inspire series of advanced designs.


title:
Magnetic massive stars as progenitors of "heavy" stellar-mass black
  holes

abstract:
  The groundbreaking detection of gravitational waves produced by the
inspiralling and coalescence of the black hole (BH) binary GW150914 confirms
the existence of "heavy" stellar-mass BHs with masses >25 Msun. Initial
modelling of the system by Abbott et al. (2016a) supposes that the formation of
black holes with such large masses from the evolution of single massive stars
is only feasible if the wind mass-loss rates of the progenitors were greatly
reduced relative to the mass-loss rates of massive stars in the Galaxy,
concluding that heavy BHs must form in low-metallicity (Z < 0.25-0.5 Zsun)
environments. However, strong surface magnetic fields also provide a powerful
mechanism for modifying mass loss and rotation of massive stars, independent of
environmental metallicity (ud-Doula & Owocki 2002; ud-Doula et al. 2008). In
this paper we explore the hypothesis that some heavy BHs, with masses >25 Msun
such as those inferred to compose GW150914, could be the natural end-point of
evolution of magnetic massive stars in a solar-metallicity environment. Using
the MESA code, we developed a new grid of single, non-rotating, solar
metallicity evolutionary models for initial ZAMS masses from 40-80 Msun that
include, for the first time, the quenching of the mass loss due to a realistic
dipolar surface magnetic field. The new models predict TAMS masses that are
significantly greater than those from equivalent non-magnetic models, reducing
the total mass lost by a strongly magnetized 80 Msun star during its main
sequence evolution by 20 Msun. This corresponds approximately to the mass loss
reduction expected from an environment with metallicity Z = 1/30 Zsun.


title: Stabilizing effect of tip splitting on the interface motion

abstract:
  Pattern-forming processes, such as electrodeposition, dielectric breakdown or
viscous fingering are often driven by instabilities. Accordingly, the resulting
growth patterns are usually highly branched, fractal structures. However, in
some of the unstable growth processes the envelope of the structure grows in a
highly regular manner, with the perturbations smoothed out over the course of
time. In this paper, we show that the regularity of the envelope growth can be
connected to small-scale instabilities leading to the tip splitting of the
fingers at the advancing front of the structure. Whenever the growth velocity
becomes too large, the finger splits into two branches. In this way it can
absorb an increased flux and thus damp the instability. Hence, somewhat
counterintuitively, the instability at a small scale results in a stability at
a larger scale. The quantitative analysis of these effects is provided by means
of the Loewner equation, which one can use to reduce the problem of the
interface motion to that of the evolution of the conformal mapping onto the
complex plane. This allows an effective analysis of the multifingered growth in
a variety of different geometries. We show how the geometry impacts the shape
of the envelope of the growing pattern and compare the results with those
observed in natural systems.

categories: nlin.PS cond-mat.stat-mech math-ph math.MP physics.flu-dyn


title:
Spin Freezing in The Frustrated Disordered Quantum Magnet
  Ba$_{3}$(Mn$_{1-x}$V$_{x}$)$_{2}$O$_{8}$

abstract:
  Ba$_3$Mn$_2$O$_8$ is a geometrically frustrated spin dimer compound. We
investigate the effect of site disorder on the zero field phase diagram of this
material by considering the solid solution
Ba$_{3}$(Mn$_{1-x}$V$_{x}$)$_{2}$O$_{8}$, where nonmagnetic V$^{5+}$ ions
partially substitute magnetic Mn$^{5+}$ ions. This substitution results in
unpaired $S=1$ moments for half-substituted dimers, which are ungapped and
therefore susceptible to types of magnetic order not present in the parent
compound. AC susceptibility measurements of compositions between $x=0.046$ and
$x=0.84$ show a sharp frequency- and composition-dependent kink at temperatures
below 210mK, suggesting that unpaired spins form a spin glass. The case for a
glassy state is made clearer by the absence of any sharp features in the
specific heat. However, Ba$_{3}$(Mn$_{1-x}$V$_{x}$)$_{2}$O$_{8}$ is not a
paradigmatic spin glass. Whereas both the freezing temperature and the Weiss
temperature (determined from susceptibility above 1K) vary strongly as a
function of composition, the heat capacity per unpaired spin is found to be
insensitive (above the glass transition) to the density of unpaired spins for
the broad regime $0.18\leq x \leq 0.84$. This surprising result is consistent
with a scenario in which nearest-neighbor unpaired spins form local, possibly
fluctuating, spin-singlets prior to the eventual spin freezing. The spin glass
state is only found for temperatures below the energy scale of single-ion
anisotropy, suggestive this plays a significant role in determining the
eventual ground state. Possible ground states in the "dilute" limit ($x < 0.04$
and $x > 0.9$) are also discussed.


title:
A Discretization-Accurate Stopping Criterion for Iterative Solvers for
  Finite Element Approximation

abstract:
  This paper introduces a discretization-accurate stopping criterion of
symmetric iterative methods for solving systems of algebraic equations
resulting from the finite element approximation. The stopping criterion
consists of the evaluations of the discretization and the algebraic error
estimators, that are based on the respective duality error estimator and the
difference of two consecutive iterates. Iterations are terminated when the
algebraic estimator is of the same magnitude as the discretization estimator.
Numerical results for multigrid $V(1,1)$-cycle and symmetric Gauss-Seidel
iterative methods are presented for the linear finite element approximation to
the Poisson equations. A large reduction in computational cost is observed
compared to the standard residual-based stopping criterion.


title:
Early Science with the Large Millimeter Telescope: discovery of the
  12CO(1-0) emission line in the ring galaxy, VIIZw466

abstract:
  We report an early science discovery of the CO(1-0) emission line in the
collisional ring galaxy, VII Zw466, using the Redshift Search Receiver
instrument on the Large Millimeter Telescope Alfonso Serrano.The apparent
molecular-to-atomic gas ratio either places the ISM of VII Zw466 in the
HI-dominated regime or implies a large quantity of CO-dark molecular gas, given
its high star formation rate. The molecular gas densities and star formation
rate densities of VII Zw466 are consistent with the standard Kennicutt-Schmidt
star formation law even though we find this galaxy to be H2-deficient. The
choice of CO-to-H2 conversion factors cannot explain the apparent H2 deficiency
in its entirety. Hence, we find that the collisional ring galaxy, VII Zw466, is
either largely deficient in both H2 and HI or contains a large mass of CO-dark
gas. A low molecular gas fraction could be due to the enhancement of feedback
processes from previous episodes of star formation as a result of the
star-forming ISM being confined to the ring. We conclude that collisional ring
galaxy formation is an extreme form of galaxy interaction that triggers a
strong galactic-wide burst of star formation that may provide immediate
negative feedback towards subsequent episodes of star formation---resulting in
a short-lived star formation history or, at least, the appearance of a
molecular gas deficit.


title: Counting Eta-Quotients of Prime Level

abstract:
  It is known that all modular forms on SL_2(Z) can be expressed as a rational
function in eta(z), eta(2z) and eta(4z). By utilizing known theorems, and
calculating the order of vanishing, we can compute the eta-quotients for a
given level. Using this count, knowing how many eta-quotients are linearly
independent and using the dimension formula, we can figure out a subspace
spanned by the eta-quotients. In this paper, we primarily focus on the case
where N=p a prime.


title:
Nuclear fragmentation induced by low-energy antiprotons within a
  microscopic transport approach

abstract:
  Within the framework of the Lanzhou quantum molecular dynamics (LQMD)
transport model, the nuclear fragmentation induced by low-energy antiprotons
has been investigated thoroughly. A coalescence approach is developed for
constructing the primary fragments in phase space. The secondary decay process
of the fragments is described by the well-known statistical code. It is found
that the localized energy released in antibaryon-baryon annihilation is
deposited in a nucleus mainly via pion-nucleon collisions, which leads to the
emissions of pre-equilibrium particles, fission, evaporation of nucleons and
light fragments etc. The strangeness exchange reactions dominate the hyperon
production. The averaged mass loss increases with the mass number of target
nucleus. A bump structure in the domain of intermediate mass for heavy targets
appears owing to the contribution of fission fragments.


title: Conformal blocks and Painlev\'e functions

abstract:
  This paper is based on my presentation at RIMS workshop on "Theory of
Integrable Systems and Its Applications in Various Fields" held in Kyoto on
19--21, August 2015. The aim of the present paper is to give a short account of
recent studies on relations between conformal blocks in the two-dimensional
conformal field theory and Painlev\'e functions. In addition, we present a
conjecture on a combinatorial expansion formula of the three-point irregular
conformal block at an irregular singular point, with two regular singular
points and one irregular singular point. Our conjectural expansion formula is
written in terms of pairs of skew Young diagrams, while the four-point regular
conformal block, by AGT correspondence, is written in terms of pairs of Young
diagrams.


title: Fine-tuning challenges for the matter bounce scenario

abstract:
  A bouncing universe with a long period of contraction during which the
average density is pressureless (the same equation of state as matter) as
cosmologically observable scales exit the Hubble horizon has been proposed as
an explanation for producing a nearly scale-invariant spectrum of adiabatic
scalar perturbations. A well-known problem with this scenario is that, unless
suppressed, the energy density associated with anisotropy grows faster than
that of the pressureless matter, so the matter-like phase is unstable. Previous
models introduce an ekpyrotic phase after the matter-like phase to prevent the
anisotropy from generating chaotic mixmaster behavior. In this work, though, we
point out that, unless the anisotropy is suppressed first, the matter-like
phase will never start and that suppressing the anisotropy requires
extraordinary, exponential fine-tuning.


title:
Measuring Impact of Adaptive and Cooperative Adaptive Cruise Control on
  Throughput of Signalized Intersections

abstract:
  To properly assess the impact of (cooperative) adaptive cruise control ACC
(CACC), one has to model vehicle dynamics. First of all, one has to choose the
car following model, as it determines the vehicle flow as vehicles accelerate
from standstill or decelerate because of the obstacle ahead. The other factor
significantly affecting the intersection throughput is the maximal vehicle
acceleration rate.
  In this paper, we analyze three car following behaviors: Gipps model,
Improved Intelligent Driver Model (IIDM) and Helly model. Gipps model exhibits
rather aggressive acceleration behavior. If used for the intersection
throughput estimation, this model would lead to overly optimistic results.
Helly model is convenient to analyze due to its linear nature, but its
deceleration behavior in the presence of obstacles ahead is unrealistically
abrupt. Showing the most realistic acceleration and deceleration behavior of
the three models, IIDM is suited for ACC/CACC impact evaluation better than the
other two.
  We discuss the influence of the maximal vehicle acceleration rate and
presence of different portions of ACC/CACC vehicles on intersection throughput
in the context of the three car following models. The analysis is done for two
cases: (1) free road downstream of the intersection; and (2) red light at some
distance downstream of the intersection.
  Finally, we introduce the platoon model and evaluate ACC and CACC with
platooning in terms of travel time ad network throughput using SUMO simulation
of the 4-mile stretch of Colorado Boulevard / Huntington Drive arterial with 13
signalized intersections in Arcadia, Southern California.


title: Semantic Scene Completion from a Single Depth Image

abstract:
  This paper focuses on semantic scene completion, a task for producing a
complete 3D voxel representation of volumetric occupancy and semantic labels
for a scene from a single-view depth map observation. Previous work has
considered scene completion and semantic labeling of depth maps separately.
However, we observe that these two problems are tightly intertwined. To
leverage the coupled nature of these two tasks, we introduce the semantic scene
completion network (SSCNet), an end-to-end 3D convolutional network that takes
a single depth image as input and simultaneously outputs occupancy and semantic
labels for all voxels in the camera view frustum. Our network uses a
dilation-based 3D context module to efficiently expand the receptive field and
enable 3D context learning. To train our network, we construct SUNCG - a
manually created large-scale dataset of synthetic 3D scenes with dense
volumetric annotations. Our experiments demonstrate that the joint model
outperforms methods addressing each task in isolation and outperforms
alternative approaches on the semantic scene completion task.


title: Curvaton as dark matter with secondary inflation

abstract:
  We consider a novel cosmological scenario in which a curvaton is long-lived
and plays the role of cold dark matter (CDM) in the presence of a short,
secondary inflation. Non-trivial evolution of the large scale cosmological
perturbation in the curvaton scenario can affect the duration of the short term
inflation, resulting in the inhomogeneous end of inflation. Non-linear
parameters of the curvature perturbation are predicted to be fNL ~ 5/4 and gNL
~ 0. The curvaton abundance can be well diluted by the short-term inflation and
accordingly, it does not have to decay into the Standard Model particles. Then
the curvaton can account for the present CDM with the isocurvature perturbation
being sufficiently suppressed because both the adiabatic and CDM isocurvature
perturbations have the same origin. As an explicit example, we consider the
thermal inflation scenario and a string axion as a candidate for this
curvaton-dark matter. We further discuss possibilities to identify the
curvaton-dark matter with the QCD axion.


title: Range Loss for Deep Face Recognition with Long-tail

abstract:
  Convolutional neural networks have achieved great improvement on face
recognition in recent years because of its extraordinary ability in learning
discriminative features of people with different identities. To train such a
well-designed deep network, tremendous amounts of data is indispensable. Long
tail distribution specifically refers to the fact that a small number of
generic entities appear frequently while other objects far less existing.
Considering the existence of long tail distribution of the real world data,
large but uniform distributed data are usually hard to retrieve. Empirical
experiences and analysis show that classes with more samples will pose greater
impact on the feature learning process and inversely cripple the whole models
feature extracting ability on tail part data. Contrary to most of the existing
works that alleviate this problem by simply cutting the tailed data for uniform
distributions across the classes, this paper proposes a new loss function
called range loss to effectively utilize the whole long tailed data in training
process. More specifically, range loss is designed to reduce overall
intra-personal variations while enlarging inter-personal differences within one
mini-batch simultaneously when facing even extremely unbalanced data. The
optimization objective of range loss is the $k$ greatest range's harmonic mean
values in one class and the shortest inter-class distance within one batch.
Extensive experiments on two famous and challenging face recognition benchmarks
(Labeled Faces in the Wild (LFW) and YouTube Faces (YTF) not only demonstrate
the effectiveness of the proposed approach in overcoming the long tail effect
but also show the good generalization ability of the proposed approach.


title: On some generalized Rapoport-Zink spaces

abstract:
  We enlarge the class of Rapoport-Zink spaces of Hodge type by modifying the
centers of the associated $p$-adic reductive groups. These such-obtained
Rapoport-Zink spaces are called of abelian type. The class of Rapoport-Zink
spaces of abelian type is strictly larger than the class of Rapoport-Zink
spaces of Hodge type, but the two type spaces are closely related as having
isomorphic connected components. The rigid analytic generic fibers of formal
Rapoport-Zink spaces of abelian type can be viewed as moduli spaces of local
$G$-shtukas in mixed characteristic in the sense of Scholze.
  We prove that Shimura varieties of abelian type can be uniformized by the
associated Rapoport-Zink spaces of abelian type. We construct and study the
Ekedahl-Oort stratifications for the special fibers of Rapoport-Zink spaces of
abelian type. As an application, we deduce a Rapoport-Zink type uniformization
for the supersingular locus of the moduli space of polarized K3 surfaces in
mixed characteristic. Moreover, we show that the Artin invariants of
supersingular K3 surfaces are related to some purely local invariants.


title: Critical behavior of Born-Infeld dilaton black holes

abstract:
  We explore the critical behavior of (n+1)-dimensional topological
Born-Infeld-dilaton black holes in an extended phase space. We treat the
cosmological constant and the Born-Infeld (BI) parameter as the thermodynamic
pressure and BI vacuum polarization which can vary. We obtain thermodynamic
quantities of the system such as pressure, temperature, Gibbs free energy, and
investigate the behaviour of these quantities. We also study the analogy of the
van der Waals liquid-gas system with the Born-Infeld-dilaton black holes in
canonical ensemble in which we can treat the black hole charge as a fixed
external parameter. Moreover, we show that the critical values of pressure,
temperature and volume are physical provided the coupling constant of dilaton
gravity is less than one and the horizon is sphere. Finally, we calculate the
critical xponents and show that although thermodynamic quantities depend on the
dilaton oupling constant, BI parameter and the dimension of the spacetime, they
are universal and are independent of metric parameters.


title:
Central limit theorem for linear spectral statistics of large
  dimensional separable sample covariance matrices

abstract:
  Suppose that $\mathbf X_n=(x_{jk})$ is $N\times n$ whose elements are
independent real variables with mean zero, variance 1 and the fourth moment
equal to three. The separable sample covariance matrix is defined as
$\mathbf{B}_n = \frac1N\mathbf{T}_{2n}^{1/2} \mathbf{X}_n \mathbf{T}_{1n}
\mathbf{X}_n' \mathbf{T}_{2n}^{1/2}$ where $\mathbf{T}_{1n}$ is a symmetric
matrix and $\mathbf{T}_{2n}^{1/2}$ is a symmetric square root of the
nonnegative definite symmetric matrix $\mathbf{T}_{2n}$. Its linear spectral
statistics (LSS) are shown to have Gaussian limits when $n/N$ approaches a
positive constant.


title: The extended Kerr-Schild approach to general relativity

abstract:
  We study in some detail the "extended Kerr-Schild" formulation of general
relativity, which decomposes the gauge-independent degrees of freedom of a
generic metric into two arbitrary functions and the choice of a flat background
tetrad. We recast Einstein's equations and spacetime curvatures in the extended
Kerr-Schild form and discuss their properties, illustrated with simple
examples.


title: Online tools for public engagement: case studies from Reykjavik

abstract:
  With the ubiquity of Internet technologies and growing demands for
transparency and open data policies, the role of social networking and online
deliberation tools for public engagement in decision-making has increased
substantially in the last decades. In this paper, we present the analysis of
how social media are used by different public bodies to enhance public
participation in deliberative democracy. We collected and reviewed published
information on the subject and carried out a field base assessment, involving
structured interviews with different government representatives and urban
policymakers. In order to compare collected data, we used a framework for
systematic analysis and comparison of e-participation platforms called the
participatory cube. The results we got were the following. Participatory
decision-making on matters of public concern justly consumes time and
resources, therefore online tools should be applied with consideration of scale
and efficiency, i.e. on burning issues for a majority of citizens or
small-scale local platforms, and in combination with meetings in real time and
space. The budget and workforce allocated to managing online engagement tools
should be proportionate to other political and administrative efforts to bring
to execution proposed ideas and act on collected feedback in order to satisfy
the needs expressed by the communities and not undermine their beliefs about
their power to influence decisions.


title:
Digital building blocks for controlling random waves based on
  supersymmetry

abstract:
  Harnessing multimode waves allows high information capacity through modal
expansions. Although passive multimode devices including waveguides, couplers,
and multiplexers have been demonstrated for broadband responses in momentum or
frequency domains, collective switching of multimodes remains a challenge, due
to the difficulty in imposing consistent dynamics on all eigenmodes. Here we
overcome this limitation by realizing digital switching of spatially random
waves, based on supersymmetric pairs of multimode potentials. We reveal that
supersymmetric transformations of any parity-symmetric potential derive the
parity reversal of all eigenmodes, which allows the complete isolation of
random waves at the 'off' state. Building blocks for binary and many-valued
logics are then demonstrated for random waves: a harmonic pair for binary
switching of arbitrary wavefronts and a P\"oschl-Teller pair for multi-level
switching which implements the fuzzy membership function. Our results
establishing global phase matching conditions for multimode dynamics will lay
the foundation of multi-channel digital photonics.


title: Analyzing the group sparsity based on the rank minimization methods

abstract:
  Sparse coding has achieved a great success in various image processing
studies. However, there is not any benchmark to measure the sparsity of image
patch/group because sparse discriminant conditions cannot keep unchanged. This
paper analyzes the sparsity of group based on the strategy of the rank
minimization. Firstly, an adaptive dictionary for each group is designed. Then,
we prove that group-based sparse coding is equivalent to the rank minimization
problem, and thus the sparse coefficient of each group is measured by
estimating the singular values of each group. Based on that measurement, the
weighted Schatten $p$-norm minimization (WSNM) has been found to be the closest
solution to the real singular values of each group. Thus, WSNM can be
equivalently transformed into a non-convex $\ell_p$-norm minimization problem
in group-based sparse coding. To make the proposed scheme tractable and robust,
the alternating direction method of multipliers (ADMM) is used to solve the
$\ell_p$-norm minimization problem. Experimental results on two applications:
image inpainting and image compressive sensing (CS) recovery have shown that
the proposed scheme outperforms many state-of-the-art methods.


title: Dynamics of the Wigner Crystal of Composite Particles

abstract:
  Conventional wisdom had long held that a composite particle behaves just like
an ordinary Newtonian particle. In this paper, we derive the effective dynamics
of a type-I Wigner crystal of composite particles directly from its microscopic
wave function. It indicates that the composite particles are subjected to a
Berry curvature in the momentum space as well as an emergent dissipationless
viscosity. Therefore, contrary to the general belief, composite particles
follow the more general Sundaram-Niu dynamics instead of the ordinary Newtonian
one. We show that the presence of the Berry curvature is an inevitable feature
for a dynamics consistent with the dipole picture of composite particles and
Kohn's theorem. Based on the dynamics, we determine the dispersions of
magneto-phonon excitations numerically. We find an emergent magneto-roton mode
which signifies the composite-particle nature of the Wigner crystal. It occurs
at frequencies much lower than the magnetic cyclotron frequency and has a
vanishing oscillator strength in the long wavelength limit.


title:
Franke-Jawerth embeddings for Besov and Triebel-Lizorkin spaces with
  variable exponents

abstract:
  The classical Jawerth and Franke embeddings $$ F^{s_0}_{p_0,q}({\mathbb
R}^n)\hookrightarrow B^{s_1}_{p_1,p_0}({\mathbb R}^n) \quad \mbox{and} \quad
B^{s_0}_{p_0,p_1}({\mathbb R}^n)\hookrightarrow F^{s_1}_{p_1,q}({\mathbb R}^n)
$$ are versions of Sobolev embedding between the scales of Besov and
Triebel-Lizorkin function spaces for $s_0>s_1$ and $$ s_0-\frac{n}{p_0} =
s_1-\frac{n}{p_1}.$$ We prove Jawerth and Franke embeddings for the scales of
Besov and Triebel-Lizorkin spaces with all exponents variable $$
F^{s_0(\cdot)}_{p_0(\cdot),q(\cdot)}\hookrightarrow
B^{s_1(\cdot)}_{p_1(\cdot),p_0(\cdot)} \quad \mbox{and} \quad
B^{s_0(\cdot)}_{p_0(\cdot),p_1(\cdot)}\hookrightarrow
F^{s_1(\cdot)}_{p_1(\cdot),q(\cdot)}, $$ respectively, if
$\inf_{x\in\mathbb{R}^n}(s_0(x)-s_1(x))>0$ and $$ s_0(x) -\frac{n}{p_0(x)} =
s_1(x) -\frac{n}{p_1(x)}, \quad x \in {\mathbb R}^n. $$ We work exclusively
with the associated sequence spaces $b^{s(\cdot)}_{p(\cdot),q(\cdot)}$ and
$f^{s(\cdot)}_{p(\cdot),q(\cdot)}$, which is justified by well known
decomposition techniques. We give also a different proof of the Franke
embedding in the constant exponent case which avoids duality arguments and
interpolation.
  Our results hold also for 2-microlocal function spaces
$B^{\mathbf{w}}_{p(\cdot),q(\cdot)}({\mathbb R}^n)$ and
$F^{\mathbf{w}}_{p(\cdot),q(\cdot)}({\mathbb R}^n)$ which unify the smoothness
scales of spaces of variable smoothness and generalized smoothness spaces.


title: Improving Fully Convolution Network for Semantic Segmentation

abstract:
  Fully Convolution Networks (FCN) have achieved great success in dense
prediction tasks including semantic segmentation. In this paper, we start from
discussing FCN by understanding its architecture limitations in building a
strong segmentation network. Next, we present our Improved Fully Convolution
Network (IFCN). In contrast to FCN, IFCN introduces a context network that
progressively expands the receptive fields of feature maps. In addition, dense
skip connections are added so that the context network can be effectively
optimized. More importantly, these dense skip connections enable IFCN to fuse
rich-scale context to make reliable predictions. Empirically, those
architecture modifications are proven to be significant to enhance the
segmentation performance. Without engaging any contextual post-processing, IFCN
significantly advances the state-of-the-arts on ADE20K (ImageNet scene
parsing), Pascal Context, Pascal VOC 2012 and SUN-RGBD segmentation datasets.


title: Exploiting Unlabeled Data for Neural Grammatical Error Detection

abstract:
  Identifying and correcting grammatical errors in the text written by
non-native writers has received increasing attention in recent years. Although
a number of annotated corpora have been established to facilitate data-driven
grammatical error detection and correction approaches, they are still limited
in terms of quantity and coverage because human annotation is labor-intensive,
time-consuming, and expensive. In this work, we propose to utilize unlabeled
data to train neural network based grammatical error detection models. The
basic idea is to cast error detection as a binary classification problem and
derive positive and negative training examples from unlabeled data. We
introduce an attention-based neural network to capture long-distance
dependencies that influence the word being detected. Experiments show that the
proposed approach significantly outperforms SVMs and convolutional networks
with fixed-size context window.


title:
On $\alpha$-largeness and the Paris-Harrington principle in
  $\mathrm{RCA}_0$ and $\mathrm{RCA}_0^{\displaystyle{*}}$

abstract:
  We examine, within $\mathrm{RCA}_0$, the treatment by Ketonen and Solovay on
the use of $\alpha$-largeness for giving an upper bound for the
Paris--Harrington principle. This proof works fine in
$\mathrm{RCA}_0^{\displaystyle{*}}$ for every fixed standard dimension. We also
show how to modify the arguments to work within
$\mathrm{RCA}_0^{\displaystyle{*}}$ for unrestricted dimensions. To the
author's knowledge, this is the first time that it is confirmed that the
treatment can be done within $\mathrm{EFA}$ without some transfinite induction
added.


title:
Scheme for detection of single-molecule radical pair reaction using spin
  in diamond

abstract:
  The radical pair reaction underlies the magnetic field sensitivity of
chemical reactions and is suggested to play an important role in both chemistry
and biology. Current experimental evidence is based on ensemble measurements,
however, the ability to probe the radical pair reaction at the single molecule
level would provide valuable information concerning its role in important
biological processes. Here, we propose a scheme to detect the charge
recombination rate in a radical pair reaction under ambient conditions by using
single nitrogen-vacancy center spin in diamond. We demonstrate theoretically
that it is possible to detect the effect of the geomagnetic field on the
radical pair reaction and propose the present scheme as a possible hybrid model
chemical compass.


title:
Nordhaus-Gaddum-type theorem for total proper connection number of
  graphs

abstract:
  A graph is said to be \emph{total-colored} if all the edges and the vertices
of the graph are colored. A path $P$ in a total-colored graph $G$ is called a
\emph{total-proper path} if $(i)$ any two adjacent edges of $P$ are assigned
distinct colors; $(ii)$ any two adjacent internal vertices of $P$ are assigned
distinct colors; $(iii)$ any internal vertex of $P$ is assigned a distinct
color from its incident edges of $P$. The total-colored graph $G$ is
\emph{total-proper connected} if any two distinct vertices of $G$ are connected
by a total-proper path. The \emph{total-proper connection number} of a
connected graph $G$, denoted by $tpc(G)$, is the minimum number of colors that
are required to make $G$ total-proper connected. In this paper, we first
characterize the graphs $G$ on $n$ vertices with $tpc(G)=n-1$. Based on this,
we obtain a Nordhaus-Gaddum-type result for total-proper connection number. We
prove that if $G$ and $\overline{G}$ are connected complementary graphs on $n$
vertices, then $6\leq tpc(G)+tpc(\overline{G})\leq n+2$. Examples are given to
show that the lower bound is sharp for $n\geq 4$. The upper bound is reached
for $n\geq 5$ if and only if $G$ or $\overline{G}$ is the tree with maximum
degree $n-2$.


title:
Object Detection Free Instance Segmentation With Labeling
  Transformations

abstract:
  Instance segmentation has attracted recent attention in computer vision and
existing methods in this domain mostly have an object detection stage. In this
paper, we study the intrinsic challenge of the instance segmentation problem,
the presence of a quotient space (swapping the labels of different instances
leads to the same result), and propose new methods that are object proposal-
and object detection- free. We propose three alternative methods, namely
pixel-based affinity mapping, superpixel-based affinity learning, and
boundary-based component segmentation, all focusing on performing labeling
transformations to cope with the quotient space problem. By adopting fully
convolutional neural networks (FCN) like models, our framework attains
competitive results on both the PASCAL dataset (object-centric) and the Gland
dataset (texture-centric), which the existing methods are not able to do. Our
work also has the advantages in its transparency, simplicity, and being all
segmentation based.


title: Relational Logic with Framing and Hypotheses: Technical Report

abstract:
  Relational properties arise in many settings: relating two versions of a
program that use different data representations, noninterference properties for
security, etc. The main ingredient of relational verification, relating aligned
pairs of intermediate steps, has been used in numerous guises, but existing
relational program logics are narrow in scope. This paper introduces a logic
based on novel syntax that weaves together product programs to express
alignment of control flow points at which relational formulas are asserted.
Correctness judgments feature hypotheses with relational specifications,
discharged by a rule for the linking of procedure implementations. The logic
supports reasoning about program-pairs containing both similar and dissimilar
control and data structures. Reasoning about dynamically allocated objects is
supported by a frame rule based on frame conditions amenable to SMT provers. We
prove soundness and sketch how the logic can be used for data abstraction, loop
optimizations, and secure information flow.


title: Berry curvature in magnon-phonon hybrid systems

abstract:
  We theoretically study the Berry curvature of the magnon induced by the
hybridization with the acoustic phonons via the spin-orbit and dipolar
interactions. We first discuss the magnon-phonon hybridization via the dipolar
interaction, and show that the dispersions have gapless points in momentum
space, some of which form a loop. Next, when both spin-orbit and dipolar
interactions are considered, we show anisotropic texture of the Berry curvature
and its divergence with and without gap-closing. Realistic evaluation of the
consequent anomalous velocity is given for yttrium iron garnet.


title: Topological stability and pseudo-orbit tracing property of group actions

abstract:
  In this note we extend the concept of topological stability from
homeomorphisms to group actions on compact metric spaces, and prove that if an
action of a finitely generated group is expansive and has the pseudo-orbit
tracing property then it is topologically stable. This represents a group
action version of the Walter's stability theorem. Moreover we give a class of
group actions with topological stability or pseudo-orbit tracing property. On
the other hand, we also provide a characterization of subshifts of finite type
over finitely generated groups in term of pseudo-orbit tracing property.


title:
Jolie Good Buildings: Internet of things for smart building
  infrastructure supporting concurrent apps utilizing distributed microservices

abstract:
  A large percentage of buildings, domestic or special-purpose, is expected to
become increasingly "smarter" in the future, due to the immense benefits in
terms of energy saving, safety, flexibility, and comfort, that relevant new
technologies offer. However, concerning the hardware, software, or platform
levels, no clearly dominant standard frameworks currently exist. Here, we will
present a prototype platform for supporting multiple concurrent applications
for smart buildings, which is utilizing an advanced sensor network as well as a
distributed micro services architecture, centrally featuring the Jolie
language. The architecture and benefits of our system are discussed, as well as
a prototype containing a number of nodes and a user interface, deployed in a
real-world academic building environment. Our results illustrate the promising
nature of our approach, as well as open avenues for future work towards it
wider and larger scale applicability.


title:
JIGSAW-GEO (1.0): locally orthogonal staggered unstructured grid
  generation for general circulation modelling on the sphere

abstract:
  An algorithm for the generation of non-uniform, locally-orthogonal staggered
unstructured spheroidal grids is described. This technique is designed to
generate very high-quality staggered Voronoi/Delaunay meshes appropriate for
general circulation modelling on the sphere, including applications to
atmospheric simulation, ocean-modelling and numerical weather prediction. Using
a recently developed Frontal-Delaunay refinement technique, a method for the
construction of high-quality unstructured spheroidal Delaunay triangulations is
introduced. A locally-orthogonal polygonal grid, derived from the associated
Voronoi diagram, is computed as the staggered dual. It is shown that use of the
Frontal-Delaunay refinement technique allows for the generation of very
high-quality unstructured triangulations, satisfying a-priori bounds on element
size and shape. Grid-quality is further improved through the application of
hill-climbing type optimisation techniques. Overall, the algorithm is shown to
produce grids with very high element quality and smooth grading
characteristics, while imposing relatively low computational expense. A
selection of uniform and non-uniform spheroidal grids appropriate for
high-resolution, multi-scale general circulation modelling are presented. These
grids are shown to satisfy the geometric constraints associated with
contemporary unstructured C-grid type finite-volume models, including the Model
for Prediction Across Scales (MPAS-O). The use of user-defined mesh-spacing
functions to generate smoothly graded, non-uniform grids for multi-resolution
type studies is discussed in detail.

categories: physics.ao-ph cs.CG physics.comp-ph physics.flu-dyn


title:
First Demonstration of Electrostatic Damping of Parametric Instability
  at Advanced LIGO

abstract:
  Interferometric gravitational wave detectors operate with high optical power
in their arms in order to achieve high shot-noise limited strain sensitivity. A
significant limitation to increasing the optical power is the phenomenon of
three-mode parametric instabilities, in which the laser field in the arm
cavities is scattered into higher order optical modes by acoustic modes of the
cavity mirrors. The optical modes can further drive the acoustic modes via
radiation pressure, potentially producing an exponential buildup. One proposed
technique to stabilize parametric instability is active damping of acoustic
modes. We report here the first demonstration of damping a parametrically
unstable mode using active feedback forces on the cavity mirror. A 15,538 Hz
mode that grew exponentially with a time constant of 182 sec was damped using
electro-static actuation, with a resulting decay time constant of 23 sec. An
average control force of 0.03 nNrms was required to maintain the acoustic mode
at its minimum amplitude.


title: DeepSetNet: Predicting Sets with Deep Neural Networks

abstract:
  This paper addresses the task of set prediction using deep learning. This is
important because the output of many computer vision tasks, including image
tagging and object detection, are naturally expressed as sets of entities
rather than vectors. As opposed to a vector, the size of a set is not fixed in
advance, and it is invariant to the ordering of entities within it. We define a
likelihood for a set distribution and learn its parameters using a deep neural
network. We also derive a loss for predicting a discrete distribution
corresponding to set cardinality. Set prediction is demonstrated on the problem
of multi-class image classification. Moreover, we show that the proposed
cardinality loss can also trivially be applied to the tasks of object counting
and pedestrian detection. Our approach outperforms existing methods in all
three cases on standard datasets.


title: Optical Properties of Monolayer Tinene in Electric Fields

abstract:
  Monolayer tinene presents rich absorption spectra in electric fields. There
are three kinds of special structures, namely shoulders, logarithmically
symmetric peaks and asymmetric peaks in the square-root form, corresponding to
the optical excitations of the extreme points, saddle points and
constant-energy loops. With the increasing field strength, two splitting
shoulder structures, which are dominated by the parabolic bands of ${5p_z}$
orbitals, come to exist because of the spin-split energy bands. The frequency
of threshold shoulder declines to zero and then linearly grows. The third
shoulder at ${0.75 \sim 0.85}$ eV mainly comes from (${5p_x,5p_y}$) orbitals.
The former and the latter orbitals, respectively, create the saddle-point
symmetric peaks near the M point, while they hybridize with one another to
generate the loop-related asymmetric peaks. Tinene quite differs from graphene,
silicene, and germanene. The special relationship among the multi-orbital
chemical bondings, spin-orbital couplings and Coulomb potentials accounts for
the feature-rich optical properties.


title: Dynamical Complexity and $K$-Theory of $L^p$ Operator Crossed Products

abstract:
  We apply quantitative (or controlled) $K$-theory to prove that a certain
$L^p$ assembly map is an isomorphism for $p\in[1,\infty)$ when an action of a
countable discrete group $\Gamma$ on a compact Hausdorff space $X$ has finite
dynamical complexity. When $p=2$, this is a model for the Baum-Connes assembly
map for $\Gamma$ with coefficients in $C(X)$, and was shown to be an
isomorphism by Guentner, Willett, and Yu.


title: New examples of r-harmonic immersions into the sphere

abstract:
  Polyharmonic, or $r$-harmonic, maps are a natural generalization of harmonic
maps whose study was proposed by Eells-Lemaire in 1983. The main aim of this
paper is to construct new examples of proper $r$-harmonic immersions into
spheres. In particular, we shall prove that the canonical inclusion $i:
S^{n-1}(R)\to S^n$ is a proper $r$-harmonic submanifold of $S^n$ if and only if
the radius $R$ is equal to $1/ \sqrt{r}$. We shall also prove the existence of
proper $r$-harmonic generalized Clifford's tori into the sphere.


title: A precolouring extension of Vizing's theorem

abstract:
  Fix a palette $\mathcal K$ of $\Delta+1$ colours, a graph with maximum degree
$\Delta$, and a subset $M$ of the edge set with minimum distance between edges
at least $9$. If the edges of $M$ are arbitrarily precoloured from $\mathcal
K$, then there is guaranteed to be a proper edge-colouring using only colours
from $\mathcal K$ that extends the precolouring on $M$ to the entire graph.
This result is a first general precolouring extension form of Vizing's theorem,
and it proves a conjecture of Albertson and Moore under a slightly stronger
distance requirement. We also show that the condition on the distance can be
lowered to $5$ when the graph contains no cycle of length $5$.


title: A vertex ordering characterization of simple-triangle graphs

abstract:
  Consider two horizontal lines in the plane. A pair of a point on the top line
and an interval on the bottom line defines a triangle between two lines. The
intersection graph of such triangles is called a simple-triangle graph. This
paper shows a vertex ordering characterization of simple-triangle graphs as
follows: a graph is a simple-triangle graph if and only if there is a linear
ordering of the vertices that contains both an alternating orientation of the
graph and a transitive orientation of the complement of the graph.


title:
Broad Band X-ray Spectra of Atoll Source 4U 1636-536: NuSTAR and Swift
  Results

abstract:
  In this work we investigate broad band (1-79 keV) spectral nature of the
atoll source 4U 1636-536 using the combined Nu-STAR and SWIFT-XRT data. The
spectra are complex and have emission components from the disc, boundary-layer
and corona. In addition to that a broad iron line is also observed. A
relativistic line model assuming Schwarzchild metric fits this feature. The
total flux varies from 1.4 $\times$ 10$^{-9}$ to 4.36 $\times$ 10$^{-9}$
$ergs/s/cm^2$. At the highest flux level the source was found in the soft
state. In this state the Comptonized component has temperature $kT_e \sim 3$
keV and optical depth $\tau \sim $ 16. We also detect a non-thermal tail with
index $\sim$ 2.4, contributing $\sim$ 10 \% of the total flux in the soft
state. We also find that the inner disc radius, electron temperature and
optical depth vary with the total 0.1-100 keV unabsorbed flux. We discuss the
implication of the results in this paper.


title:
The dimple problem related to space-time modeling under the Lagrangian
  framework

abstract:
  Space-time covariance modeling under the Lagrangian framework has been
especially popular to study atmospheric phenomena in the presence of transport
effects, such as prevailing winds or ocean currents, which are incompatible
with the assumption of full symmetry. In this work, we assess the dimple
problem (Kent et al., 2011) for covariance functions coming from transport
phenomena. We work under two important cases: the spatial domain can be either
the $d$-dimensional Euclidean space $\mathbb{R}^d$ or the spherical shell of
$\mathbb{R}^d$. The choice is relevant for the type of metric chosen to
describe spatial dependence. In particular, in Euclidean spaces, we work under
very general assumptions with the case of radial symmetry being deduced as a
corollary of a more general result. We illustrate through examples that, under
this framework, the dimple is a natural and physically interpretable property.


title:
Precise measurement of the thermal and stellar $^{54}$Fe($n,
  \gamma$)$^{55}$Fe cross sections via AMS

abstract:
  The detection of long-lived radionuclides through ultra-sensitive single atom
counting via accelerator mass spectrometry (AMS) offers opportunities for
precise measurements of neutron capture cross sections, e.g. for nuclear
astrophysics. The technique represents a truly complementary approach,
completely independent of previous experimental methods. The potential of this
technique is highlighted at the example of the $^{54}$Fe($n, \gamma$)$^{55}$Fe
reaction. Following a series of irradiations with neutrons from cold and
thermal to keV energies, the produced long-lived $^{55}$Fe nuclei
($t_{1/2}=2.744(9)$ yr) were analyzed at the Vienna Environmental Research
Accelerator (VERA). A reproducibility of about 1% could be achieved for the
detection of $^{55}$Fe, yielding cross section uncertainties of less than 3%.
Thus, the new data can serve as anchor points to time-of-flight experiments. We
report significantly improved neutron capture cross sections at thermal energy
($\sigma_{th}=2.30\pm0.07$ b) as well as for a quasi-Maxwellian spectrum of
$kT=25$ keV ($\sigma=30.3\pm1.2$ mb) and for $E_n=481\pm53$ keV ($\sigma=
6.01\pm0.23$ mb). The new experimental cross sections have been used to deduce
improved Maxwellian average cross sections in the temperature regime of the
common $s$-process scenarios. The astrophysical impact is discussed using
stellar models for low-mass AGB stars.


title: Hyperspectral CNN Classification with Limited Training Samples

abstract:
  Hyperspectral imaging sensors are becoming increasingly popular in robotics
applications such as agriculture and mining, and allow per-pixel thematic
classification of materials in a scene based on their unique spectral
signatures. Recently, convolutional neural networks have shown remarkable
performance for classification tasks, but require substantial amounts of
labelled training data. This data must sufficiently cover the variability
expected to be encountered in the environment. For hyperspectral data, one of
the main variations encountered outdoors is due to incident illumination, which
can change in spectral shape and intensity depending on the scene geometry. For
example, regions occluded from the sun have a lower intensity and their
incident irradiance skewed towards shorter wavelengths.
  In this work, a data augmentation strategy based on relighting is used during
training of a hyperspectral convolutional neural network. It allows training to
occur in the outdoor environment given only a small labelled region, which does
not need to sufficiently represent the geometric variability of the entire
scene. This is important for applications where obtaining large amounts of
training data is labourious, hazardous or difficult, such as labelling pixels
within shadows. Radiometric normalisation approaches for pre-processing the
hyperspectral data are analysed and it is shown that methods based on the raw
pixel data are sufficient to be used as input for the classifier. This removes
the need for external hardware such as calibration boards, which can restrict
the application of hyperspectral sensors in robotics applications. Experiments
to evaluate the classification system are carried out on two datasets captured
from a field-based platform.


title: Minimax Signal Detection Under Weak Noise Assumptions

abstract:
  We consider minimax signal detection in the sequence model. Working with
certain ellipsoids in the space of square-summable sequences of real numbers,
with a ball of positive radius removed, we obtain upper and lower bounds for
the minimax separation radius in the non-asymptotic framework, i.e., for a
fixed value of the involved noise level. We use very weak assumptions on the
noise (i.e., fourth moments are assumed to be uniformly bounded). In
particular, we do not use any kind of Gaussianity or independence assumption on
the noise. It is shown that the established minimax separation rates are not
faster than the ones obtained in the classical sequence model (i.e.,
independent standard Gaussian noise) but, surprisingly, are of the same order
as the minimax estimation rates in the classical setting. Under an additional
condition on the noise, the classical minimax separation rates are also
retrieved in benchmark well-posed and ill-posed inverse problems.


title:
A Self-Authentication and Deniable Efficient Group Key Agreement
  Protocol for VANET

abstract:
  With the rapid development of vehicular ad hoc Network (VANET), it is gaining
significant popularity and receiving increasing attentions from academics and
industry in security and efficiency. To address security and efficiency issues,
a self-authentication and deniable efficient group key agreement protocol is
proposed in this paper. This scheme establishes a group between road-side unit
(RSU) and vehicles by using self-authentication without certification
authority, and enhances certification efficiency by using group key (GK)
transmission method. At the same time, to avoid the attacker to attack the
legal vehicle by RSU, we adopt deniable group key agreement method to
negotiation session key (sk) and use it to transmit GK between RSU. In
addition, vehicles not only broadcast messages to other vehicles, but also
communicate with other members in the same group. So group communication is
necessary in VANET. Finally, the security and performance analysis shown that
our scheme is security, meanwhile the verification delay, transmission
overheard and message delay are more efficient than other related schemes in
authentication, transmission and communication.


title:
3D Human Pose Estimation from a Single Image via Distance Matrix
  Regression

abstract:
  This paper addresses the problem of 3D human pose estimation from a single
image. We follow a standard two-step pipeline by first detecting the 2D
position of the $N$ body joints, and then using these observations to infer 3D
pose. For the first step, we use a recent CNN-based detector. For the second
step, most existing approaches perform 2$N$-to-3$N$ regression of the Cartesian
joint coordinates. We show that more precise pose estimates can be obtained by
representing both the 2D and 3D human poses using $N\times N$ distance
matrices, and formulating the problem as a 2D-to-3D distance matrix regression.
For learning such a regressor we leverage on simple Neural Network
architectures, which by construction, enforce positivity and symmetry of the
predicted matrices. The approach has also the advantage to naturally handle
missing observations and allowing to hypothesize the position of non-observed
joints. Quantitative results on Humaneva and Human3.6M datasets demonstrate
consistent performance gains over state-of-the-art. Qualitative evaluation on
the images in-the-wild of the LSP dataset, using the regressor learned on
Human3.6M, reveals very promising generalization results.


title: Scalable Fine-grained Path Control in Software Defined Networks

abstract:
  The OpenFlow-based SDN is widely studied to better network performance
through planning fine-grained paths. However, being designed to configure path
hop-by-hop, it faces the scalability issue that both the flow table overhead
and path setup delay are unacceptable for large-scale networks. In this paper,
we propose PACO, a framework based on Source Routing to address that problem
through quickly pushing paths into the packet header at network edges and
pre-installing few rules at the network core. The straightforward
implementation of SR is inefficient as it would incur too many path labels;
other efficient approaches would sacrifice path flexibility (e.g., DEFO). To
implement SR efficiently and flexibly, PACO presents each path as a
concatenation of pathlets and introduces algorithms to compute pathlets and
concatenate paths with minimum path labels. Our extensive simulations confirm
the scalability of PACO as it saves the flow table overhead up to 94% compared
with OpenFlow-SDN solutions and show that PACO outperforms SR-SDN solutions by
supporting more than 40% paths with few label overhead.


title: Online Knapsack Problem and Budgeted Truthful Bipartite Matching

abstract:
  Two related online problems: knapsack and truthful bipartite matching are
considered. For these two problems, the common theme is how to `match' an
arriving left vertex in an online fashion with any of the available right
vertices, if at all, so as to maximize the sum of the value of the matched
edges, subject to satisfying a sum-weight constraint on the matched left
vertices. Assuming that the left vertices arrive in an uniformly random order
(secretary model), two almost similar algorithms are proposed for the two
problems, that are $2e$ competitive and $24$ competitive, respectively. The
proposed online bipartite matching algorithm is also shown to be truthful:
there is no incentive for any left vertex to misreport its bid/weight. Direct
applications of these problems include job allocation with load balancing,
generalized adwords, crowdsourcing auctions, and matching wireless users to
cooperative relays in device-to-device communication enabled cellular network.


title: Certain inequalities involving the k-Struve function

abstract:
  We aim to introduce a $\mathtt{k}$-Struve function and investigate its
various properties, including mainly certain inequalities associated this
function. One of the inequalities given here is pointed out to be related to
the so-called classical Tur\'an type inequality. We also present a differential
equation, several recurrence relations, and integral representations for this
$\mathtt{k}$-Struve function.


title: Blocking and Other Enhancements for Bottom-Up Model Generation Methods

abstract:
  Model generation is a problem complementary to theorem proving and is
important for fault analysis and debugging of formal specifications of security
protocols, programs and terminological definitions. This paper discusses
several ways of enhancing the paradigm of bottom-up model generation. The two
main contributions are new, generalized blocking techniques and a new
range-restriction transformation. The blocking techniques are based on simple
transformations of the input set together with standard equality reasoning and
redundancy elimination techniques. These provide general methods for finding
small, finite models. The range-restriction transformation refines existing
transformations to range-restricted clauses by carefully limiting the creation
of domain terms. All possible combinations of the introduced techniques and
classical range-restriction were tested on the clausal problems of the TPTP
Version 6.0.0 with an implementation based on the SPASS theorem prover using a
hyperresolution-like refinement. Unrestricted domain blocking gave best results
for satisfiable problems showing it is a powerful technique indispensable for
bottom-up model generation methods. Both in combination with the new
range-restricting transformation, and the classical range-restricting
transformation, good results have been obtained. Limiting the creation of terms
during the inference process by using the new range restricting transformation
has paid off, especially when using it together with a shifting transformation.
The experimental results also show that classical range restriction with
unrestricted blocking provides a useful complementary method. Overall, the
results showed bottom-up model generation methods were good for disproving
theorems and generating models for satisfiable problems, but less efficient
than SPASS in auto mode for unsatisfiable problems.


title:
Specific-heat exponent and modified hyperscaling in the 4D random-field
  Ising model

abstract:
  We report a high-precision numerical estimation of the critical exponent
$\alpha$ of the specific heat of the random-field Ising model in four
dimensions. Our result $\alpha = 0.12(1)$ indicates a diverging specific-heat
behavior and is consistent with the estimation coming from the modified
hyperscaling relation using our estimate of $\theta$ via the anomalous
dimensions $\eta$ and $\bar{\eta}$. Our analysis benefited form a
high-statistics zero-temperature numerical simulation of the model for two
distributions of the random fields, namely a Gaussian and Poissonian
distribution, as well as recent advances in finite-size scaling and reweighting
methods for disordered systems. An original estimate of the critical slowing
down exponent $z$ of the maximum-flow algorithm used is also provided.


title:
Generalized uncertainty principles, effective Newton constant and
  regular black holes

abstract:
  In this paper, we explore the quantum spacetimes that are potentially
connected with the generalized uncertainty principles. By analyzing the
gravity-induced quantum interference pattern and the Gedanken for weighting
photon, we find that the generalized uncertainty principles inspire the
effective Newton constant as same as our previous proposal. A characteristic
momentum associated with the tidal effect is suggested, which incorporates the
quantum effect with the geometric nature of gravity. When the simplest
generalized uncertainty principle is considered, the minimal model of the
regular black holes is reproduced by the effective Newton constant. The black
hole's tunneling probability, accurate to the second order correction, is
carefully analyzed. We find that the tunneling probability is regularized by
the size of the black hole remnant. Moreover, the black hole remnant is the
final state of a tunneling process that the probability is minimized. A theory
of modified gravity is suggested, by substituting the effective Newton constant
into the Hilbert-Einstein action.


title: On Prefix Normal Words and Prefix Normal Forms

abstract:
  A $1$-prefix normal word is a binary word with the property that no factor
has more $1$s than the prefix of the same length; a $0$-prefix normal word is
defined analogously. These words arise in the context of indexed binary jumbled
pattern matching, where the aim is to decide whether a word has a factor with a
given number of $1$s and $0$s (a given Parikh vector). Each binary word has an
associated set of Parikh vectors of the factors of the word. Using prefix
normal words, we provide a characterization of the equivalence class of binary
words having the same set of Parikh vectors of their factors.
  We prove that the language of prefix normal words is not context-free and is
strictly contained in the language of pre-necklaces, which are prefixes of
powers of Lyndon words. We give enumeration results on $\textit{pnw}(n)$, the
number of prefix normal words of length $n$, showing that, for sufficiently
large $n$, \[ 2^{n-4 \sqrt{n \lg n}} \le \textit{pnw}(n) \le 2^{n - \lg n + 1}.
\]
  For fixed density (number of $1$s), we show that the ordinary generating
function of the number of prefix normal words of length $n$ and density $d$ is
a rational function. Finally, we give experimental results on
$\textit{pnw}(n)$, discuss further properties, and state open problems.


title: Rises in forests of binary shrubs

abstract:
  The study of patterns in permutations associated with forests of binary
shrubs was initiated by D. Bevan et al.. In this paper, we study five different
types of rise statistics that can be associated with such permutations and find
the generating functions for the distribution of such rise statistics.


title:
Hydrolytic and lysozymic degradability of chitosan systems with
  heparin-mimicking pendant groups

abstract:
  Chitosan (CT) is an antibacterial polysaccharide that has been investigated
for drug carriers, haemostats and wound dressings. For these applications,
customised CT devices can often be obtained with specific experimental
conditions, which can irreversibly alter native biopolymer properties and
functions and lead to unreliable material behaviour. In order to investigate
the structure-function relationships in CT covalent networks, monosodium
5-sulfoisophthalate (PhS) was selected as heparin-mimicking, growth
factor-binding crosslinking segment, whilst 1,4-phenylenediacetic acid (4Ph)
and poly(ethylene glycol) bis(carboxymethyl) ether (PEG) were employed as
sulfonic acid-free diacids of low and high crosslinker length respectively.
Hydrogels based on short crosslinkers (PhS and 4Ph) displayed increased
crosslink density, decreased swelling ratio as well as minimal hydrolytic and
lysozymic degradation, whilst addition of lysozymes to PEG based networks
resulted in 70 wt.-% mass loss. PhS-crosslinked CT hydrogels displayed the
highest loss (40 +/- 6 CFU%) of antibacterial activity upon incubation with
Porphyromonas gingivalis, whilst respective extracts were tolerated by L929
mouse fibroblasts.


title:
Developing a cardiovascular disease risk factor annotated corpus of
  Chinese electronic medical records

abstract:
  Cardiovascular disease (CVD) has become the leading cause of death in China,
and most of the cases can be prevented by controlling risk factors. The goal of
this study was to build a corpus of CVD risk factor annotations based on
Chinese electronic medical records (CEMRs). This corpus is intended to be used
to develop a risk factor information extraction system that, in turn, can be
applied as a foundation for the further study of the progress of risk factors
and CVD. We designed a light annotation task to capture CVD risk factors with
indicators, temporal attributes and assertions that were explicitly or
implicitly displayed in the records. The task included: 1) preparing data; 2)
creating guidelines for capturing annotations (these were created with the help
of clinicians); 3) proposing an annotation method including building the
guidelines draft, training the annotators and updating the guidelines, and
corpus construction. Then, a risk factor annotated corpus based on
de-identified discharge summaries and progress notes from 600 patients was
developed. Built with the help of clinicians, this corpus has an
inter-annotator agreement (IAA) F1-measure of 0.968, indicating a high
reliability. To the best of our knowledge, this is the first annotated corpus
concerning CVD risk factors in CEMRs and the guidelines for capturing CVD risk
factor annotations from CEMRs were proposed. The obtained document-level
annotations can be applied in future studies to monitor risk factors and CVD
over the long term.


title:
Interface Formulation and High Order Numerical Solutions of PDEs with
  Low Regularity

abstract:
  Linear elastic fracture mechanics admit analytic solutions that have low
regularity at crack tips. Current numerical methods for partial differential
equations (PDEs) of this type suffer from the constraint of such low
regularity, and fail to deliver optimal high order rate of convergence. We
approach the problem by (i) choosing an artificial interface to enclose the
center of the low regularity; and (ii) representing the solution in the
interior of artificial interface as unknown linear combination of known modes
of low regular solutions. This gives rise to an interface formulation of the
original PDE, and the linear combination are represented the interface
conditions. By enforcing the smooth component of numerical solution in the
interior domain to be approximately zero, a least square problem is obtained
for the unknown coefficients. The solution of this least square problem will
provide approximate interface conditions for the numerical solution of the PDE
in the exterior domain. The potential of our interface formulation is favorably
demonstrated by numerical experiments on 1-D and 2-D Poisson equations with low
regular solutions. High order numerical solutions of unknown coefficients and
PDEs are obtained. This proves the potential of the proposed interface
formulation as the theoretical basis for solving linear elastic fracture
mechanics problems. We indicate the relations between our interface formulation
and domain decomposition methods as well as a regularization strategy for the
Poisson-Boltzmann equation with singular charge density.


title:
Backward Stochastic Differential Equations with Nonmarkovian Singular
  Terminal Values

abstract:
  We solve a class of BSDE with a power function $f(y) = y^q$, $q > 1$, driving
its drift and with the terminal boundary condition $ \xi = \infty \cdot
\mathbf{1}_{B(m,r)^c}$ (for which $q > 2$ is assumed) or $ \xi = \infty \cdot
\mathbf{1}_{B(m,r)}$, where $B(m,r)$ is the ball in the path space $C([0,T])$
of the underlying Brownian motion centered at the constant function $m$ and
radius $r$. The solution involves the derivation and solution of a related heat
equation in which $f$ serves as a reaction term and which is accompanied by
singular and discontinuous Dirichlet boundary conditions. Although the solution
of the heat equation is discontinuous at the corners of the domain the BSDE has
continuous sample paths with the prescribed terminal value.


title:
Separation of Stellar Populations by an Evolving Bar: Implications for
  the Bulge of the Milky Way

abstract:
  We present a novel interpretation of the previously puzzling different
behaviours of stellar populations of the Milky Way's bulge. We first show, by
means of pure N-body simulations, that initially co-spatial stellar populations
with different in-plane random motions separate when a bar forms. The radially
cooler populations form a strong bar, and are vertically thin and
peanut-shaped, while the hotter populations form a weaker bar and become a
vertically thicker box. We demonstrate that it is the radial, not the vertical,
velocity dispersion that dominates this evolution. Assuming that early stellar
discs heat rapidly as they form, then both the in-plane and vertical random
motions correlate with stellar age and chemistry, leading to different density
distributions for metal-rich and metal-poor stars. We then use a
high-resolution simulation, in which all stars form out of gas, to demonstrate
that this is what happens. When we apply these results to the Milky Way we show
that a very broad range of observed trends for ages, densities, kinematics and
chemistries, that have been presented as evidence for contradictory paths to
the formation of the bulge, are in fact consistent with a bulge which formed
from a continuum of disc stellar populations which were kinematically separated
by the bar. For the first time we are able to account for the bulge's main
trends via a model in which the bulge formed largely in situ. Since the model
is generic, we also predict the general appearance of stellar population maps
of external edge-on galaxies.


title:
Dynamical Responses to External Stimuli for Both Cases of Excitatory and
  Inhibitory Synchronization in A Complex Neuronal Network

abstract:
  For studying how dynamical responses to external stimuli depend on the
synaptic-coupling type, we consider two types of excitatory and inhibitory
synchronization (i.e., synchronization via synaptic excitation and inhibition)
in complex small-world networks of excitatory regular spiking (RS) pyramidal
neurons and inhibitory fast spiking (FS) interneurons. For both cases of
excitatory and inhibitory synchronization, effects of synaptic couplings on
dynamical responses to external time-periodic stimuli $S(t)$ (applied to a
fraction of neurons) are investigated by varying the driving amplitude $A$ of
$S(t)$. Stimulated neurons are phase-locked to external stimuli for both cases
of excitatory and inhibitory couplings. On the other hand, the stimulation
effect on non-stimulated neurons depends on the type of synaptic coupling. The
external stimulus $S(t)$ makes a constructive effect on excitatory
non-stimulated RS neurons (i.e., it causes external phase lockings in the
non-stimulated sub-population), while $S(t)$ makes a destructive effect on
inhibitory non-stimulated FS interneurons (i.e., it breaks up original
inhibitory synchronization in the non-stimulated sub-population). As results of
these different effects of $S(t)$, the type and degree of dynamical response
(e.g., synchronization enhancement or suppression), characterized by the
dynamical response factor $D_f$ (given by the ratio of synchronization degree
in the presence and absence of stimulus), are found to vary in a distinctly
different way, depending on the synaptic-coupling type. Furthermore, we also
measure the matching degree between the dynamics of the two sub-populations of
stimulated and non-stimulated neurons in terms of a "cross-correlation" measure
$M_c$. With increasing $A$, based on $M_c$, we discuss the cross-correlations
between the two sub-populations, affecting the dynamical responses to $S(t)$.


title:
Coupled-channels Faddeev AGS calculation of $K^{-}ppn$ and $K^{-}ppp$
  quasi-bound states

abstract:
  Using separable $\bar{K}N-\pi\Sigma$ potentials in the Faddeev equations, we
calculated the binding energies and widths of the $K^{-}pp$, $K^{-}ppn$ and
$K^{-}ppp$ quasi-bound states on the basis of three- and four-body
Alt-Grassberger-Sandhas equations in the momentum representation. One- and
two-pole version of $\bar{K}N-\pi\Sigma$ interaction are considered and the
dependence of the resulting few-body energy on the two-body
$\bar{K}N-\pi\Sigma$ potential was investigated. The $s$-wave [3+1] and [2+2]
sub-amplitudes are obtained by using the Hilbert-Schmidt expansion procedure
for the integral kernels. As a result, we found a four-body resonance of the
$K^{-}ppn$ and $K^{-}ppp$ quasi-bound states with a binding energy in the range
$B_{K^{-}ppn}\sim{55-70}$ and $B_{K^{-}ppp}\sim{90-100}$ MeV, respectively. The
calculations yielded full width of $\Gamma_{K^{-}ppn}\sim{16-20}$ and
$\Gamma_{K^{-}ppp}\sim{7-20}$ MeV.


title: Awesome Typography: Statistics-Based Text Effects Transfer

abstract:
  In this work, we explore the problem of generating fantastic special-effects
for the typography. It is quite challenging due to the model diversities to
illustrate varied text effects for different characters. To address this issue,
our key idea is to exploit the analytics on the high regularity of the spatial
distribution for text effects to guide the synthesis process. Specifically, we
characterize the stylized patches by their normalized positions and the optimal
scales to depict their style elements. Our method first estimates these two
features and derives their correlation statistically. They are then converted
into soft constraints for texture transfer to accomplish adaptive multi-scale
texture synthesis and to make style element distribution uniform. It allows our
algorithm to produce artistic typography that fits for both local texture
patterns and the global spatial distribution in the example. Experimental
results demonstrate the superiority of our method for various text effects over
conventional style transfer methods. In addition, we validate the effectiveness
of our algorithm with extensive artistic typography library generation.


title: Macroscopic Conductivity of Free Fermions in Disordered Media

abstract:
  We conclude our analysis of the linear response of charge transport in
lattice systems of free fermions subjected to a random potential by deriving
general mathematical properties of its conductivity at the macroscopic scale.
The present paper belongs to a succession of studies on Ohm and Joule's laws
from a thermodynamic viewpoint. We show, in particular, the existence and
finiteness of the conductivity measure $\mu _{\mathbf{\Sigma }}$ for
macroscopic scales. Then we prove that, similar to the conductivity measure
associated to Drude's model, $\mu _{\mathbf{\Sigma }}$ converges in the
weak$^{\ast } $-topology to the trivial measure in the case of perfect
insulators (strong disorder, complete localization), whereas in the limit of
perfect conductors (absence of disorder) it converges to an atomic measure
concentrated at frequency $\nu =0$. However, the AC--conductivity $\mu
_{\mathbf{\Sigma }}|_{\mathbb{R}\backslash \{0\}}$ does not vanish in general:
We show that $\mu _{\mathbf{\Sigma }}(\mathbb{R}\backslash \{0\})>0$, at least
for large temperatures and a certain regime of small disorder.


title: Analyzing Features for the Detection of Happy Endings in German Novels

abstract:
  With regard to a computational representation of literary plot, this paper
looks at the use of sentiment analysis for happy ending detection in German
novels. Its focus lies on the investigation of previously proposed sentiment
features in order to gain insight about the relevance of specific features on
the one hand and the implications of their performance on the other hand.
Therefore, we study various partitionings of novels, considering the highly
variable concept of "ending". We also show that our approach, even though still
rather simple, can potentially lead to substantial findings relevant to
literary studies.


title:
Quantum theory in real Hilbert space: How the complex Hilbert space
  structure emerges from Poincar\'e symmetry

abstract:
  As established by Sol\`er, Quantum Theories may be formulated in real,
complex or quaternionic Hilbert spaces only. St\"uckelberg provided physical
reasons for ruling out real Hilbert spaces relying on Heisenberg principle.
Focusing on this issue from another viewpoint, we argue that there is a
fundamental reason why elementary quantum systems are not described in real
Hilbert spaces: their symmetry group. We consider an elementary relativistic
system within Wigner's approach defined as a locally-faithful irreducible
continuous unitary representation of the Poincar\'e group in a real Hilbert
space. We prove that, if the squared-mass operator is non-negative, the system
admits a natural, Poincar\'e invariant and unique up to sign, complex structure
which commutes with the whole algebra of observables generated by the
representation. All that leads to a physically equivalent formulation in a
complex Hilbert space. Differently from what happens in the real picture, here
all selfadjoint operators are observables in accordance with Sol\`er's thesis,
and the standard quantum version of Noether theorem holds. We next focus on the
physical hypotheses adopted to define a quantum elementary relativistic system
relaxing them and making our model physically more general. We use a physically
more accurate notion of irreducibility regarding the algebra of observables
only, we describe the symmetries in terms of automorphisms of the restricted
lattice of elementary propositions and we adopt a notion of continuity referred
to the states. Also in this case, the final result proves that there exist a
unique (up to sign) Poincar\'e invariant complex structure making the theory
complex and completely fitting into Sol\`er's picture. This complex structure
reveals a nice interplay of Poincar\'e symmetry and the classification of the
commutant of irreducible real von Neumann algebras.

categories: math-ph hep-th math.MP math.OA math.RT quant-ph


title:
A modelling and computational study of the frustration index in signed
  networks

abstract:
  Computing the frustration index of a signed graph is a key step toward
solving problems in many fields including social networks, political science,
physics, chemistry, and biology. The frustration index determines the distance
of a network from a state of total structural balance. Although the definition
of the frustration index goes back to the 1950's, its exact algorithmic
computation, which is closely related to classic NP-hard graph problems, has
only become a focus in recent years. We develop three new binary linear
programming models to compute the frustration index exactly and efficiently as
the solution to a global optimisation problem. Solving the models with
prioritised branching and valid inequalities in Gurobi, we can compute the
frustration index of real signed networks with over 15000 edges in less than a
minute on inexpensive hardware. We provide extensive performance analysis for
both random and real signed networks and show that our models outperform all
existing approaches by large factors. Based on solve time, algorithm output,
and effective branching factor we highlight the superiority of our models to
both exact and heuristic methods in the literature.


title:
Continuous and discontinuous morphological transitions between capillary
  bridges on a beaded chain pulled out from a liquid

abstract:
  We describe theoretically and validate experimentally the mechanism of
formation of capillary bridges during pulling a beaded chain out from a liquid
with a planar surface. There are two types of capillary bridges present in this
system, namely the sphere-planar liquid surface bridge initially formed between
the spherical bead leaving the liquid bath and the original bulk planar liquid
surface, and the sphere-sphere capillary bridge formed between neighbouring
beads in the part of the chain above the liquid surface. During pulling the
chain out of the liquid, the sphere-planar liquid surface bridge transforms
into the sphere-sphere bridge. We show that for monodisperse spherical beads
comprising the chain, this morphological phase transition can be either
continuous or discontinuous. The transition is continuous when the diameter of
the spherical beads is larger than the capillary length. Otherwise, the
transition is discontinuous, likewise the capillary force acting on the chain.


title:
Gravitational waves induced by massless vector fields with non-minimal
  coupling to gravity

abstract:
  In this paper, we calculate the contribution of the late time mode of a
massless vector field to the power spectrum of the primordial gravitational
wave using retarded Green's propagator. We consider a non-trivial coupling
between gravity and the vector field. We find that the correction is
scale-invariant and of order $\frac{H^4}{M_P^4}$. The non-minimal coupling
leads to a dependence of $\frac{H^2}{M^2}$, which can amplify the correlation
function up to the level of $\frac{H^2}{M^2_P}$.


title: Triangulability of Convex Graphs and Convex Skewness

abstract:
  Motivated by a result of [1] which states that if F is a subgraph of a convex
complete graph K_n and F contains no boundary edge of K_n and |E(F)| \leq n-3,
then K_n - F admits a triangulation, we determine necessary and sufficient
conditions on F with |E(F)| \leq n-1 for which the conclusion remains true. For
|E(F)| \geq n, we investigate the possibility of packing F in K_n such that K_n
-F admits a triangulation for certain families of graphs F. These results are
then applied to determine the convex skewness of the convex graphs of the form
K_n - F.


title:
An adaptive-size multi-domain pseudospectral approach for solving the
  time-dependent Schr\"odinger equation

abstract:
  We show that a pseudospectral representation of the wavefunction using
multiple spatial domains of variable size yields a highly accurate, yet
efficient method to solve the time-dependent Schr\"odinger equation. The
overall spatial domain is split into non-overlapping intervals whose size is
chosen according to the local de Broglie wavelength. A multi-domain weak
formulation of the Schr\"odinger equation is obtained by representing the
wavefunction by Lagrange polynomials with compact support in each domain,
discretized at the Legendre-Gauss-Lobatto points. The resulting Hamiltonian is
sparse, allowing for efficient diagonalization and storage. Accurate time
evolution is carried out by the Chebychev propagator, involving only sparse
matrix-vector multiplications. Our approach combines the efficiency of mapped
grid methods with the accuracy of spectral representations based on Gaussian
quadrature rules and the stability and convergence properties of polynomial
propagators. We apply this method to high-harmonic generation and examine the
role of the initial state for the harmonic yield near the cutoff.


title: Algebraic Laws for True Concurrency

abstract:
  We find the algebraic laws for true concurrency. Eventually, we establish a
whole axiomatization for true concurrency called APTC (Algebra for Parallelism
in True Concurrency). The theory APTC has four modules: BATC (Basic Algebra for
True Concurrency), APTC (Algebra for Parallelism in True Concurrency),
recursion and abstraction. And also, we show the applications and extensions of
APTC.


title:
Microscopic Foundations of Ohm and Joule's Laws - The Relevance of
  Thermodynamics

abstract:
  We give a brief historical account on microscopic explanations of electrical
conduction. One aim of this short review is to show that Thermodynamics is
fundamental to the theoretical understanding of the phenomenon. We discuss how
the 2nd law, implemented in the scope of Quantum Statistical Mechanics, can be
naturally used to give mathematical sense to conductivity of very general
quantum many-body models. This is reminiscent of original ideas of J.P. Joule.
We start with Ohm and Joule's discoveries and proceed by describing the Drude
model of conductivity. The impact of Quantum Mechanics and the Anderson model
are also discussed. The exposition is closed with the presentation of our
approach to electrical conductivity based on the 2nd law of Thermodynamics as
passivity of systems at thermal equilibrium. It led to new rigorous results on
linear conductivity of interacting fermions. One example is the existence of
so-called AC-conductivity measures for such a physical system. These measures
are, moreover, Fourier transforms of time correlations of current fluctuations
in the system. I.e., the conductivity satisfies, for a large class of quantum
mechanical microscopic models, Green-Kubo relations.

categories: math-ph math.MP physics.hist-ph quant-ph


title: Nuclear scissors modes and hidden angular momenta

abstract:
  The coupled dynamics of low lying modes and various giant resonances are
studied with the help of the Wigner Function Moments method generalized to take
into account spin degrees of freedom and pair correlations simultaneously. The
method is based on Time Dependent Hartree-Fock-Bogoliubov equations. The model
of the harmonic oscillator including spin-orbit potential plus
quadrupole-quadrupole and spin-spin interactions is considered. New low lying
spin dependent modes are analyzed. Special attention is paid to the scissors
modes. A new source of nuclear magnetism, connected with counter-rotation of
spins up and down around the symmetry axis (hidden angular momenta), is
discovered. Its inclusion into the theory allows one to improve substantially
the agreement with experimental data in the description of energies and
transition probabilities of scissors modes.


title: Extinction by the long dielectric needles

abstract:
  Electromagnetic wave extinction by the very long but finite dielectric needle
is compared with that by the infinite dielectric cylinder for an oblique
incidence of the electromagnetic wave. It is shown that the renormalized Hankel
functions without the logarithmic terms should be used for the calculation of
the extinction per unit length of the infinite dielectric cylinder to apply it
for extinction calculations by the finite dielectric cylinder.


title: Quantum Control in Qutrit Systems using Hybrid Rabi-STIRAP Pulses

abstract:
  We introduce and analyze theoretically a procedure that combines slow
adiabatic STIRAP manipulation with short nonadiabatic Rabi pulses to produce
any desired three-level state in a qutrit system. In this protocol, the fast
pulses create superpositions between the ground state and the first excited
state, while the slow pulses transfer an arbitrary population to the second
excited state via stimulated Raman adiabatic passage (STIRAP). We demonstrate
high-fidelity quantum control of the level populations and phases and we
characterize the errors incurred under the breakdown of adiabaticity. In a
configuration where an ancillary state is available, we show how to realize a
nondemolition monitoring of the relative phases. These methods are general and
can be implemented on any experimental platform where a quantum system with at
least three accessible energy levels is available. We discuss here in detail
experimental implementations in circuit quantum electrodynamics (QED) based on
the results obtained with a transmon, where the control of population using the
hybrid Rabi-STIRAP sequence has been achieved.