title: Sparsity-driven weighted ensemble classifier

abstract:
  In this study, a novel sparsity-driven weighted ensemble classifier (SDWEC)
that improves classification accuracy and minimizes the number of classifiers
is proposed. Using pre-trained classifiers, an ensemble in which base
classifiers votes according to assigned weights is formed. These assigned
weights directly affect classifier accuracy. In the proposed method, ensemble
weights finding problem is modeled as a cost function with the following terms:
(a) a data fidelity term aiming to decrease misclassification rate, (b) a
sparsity term aiming to decrease the number of classifiers, and (c) a
non-negativity constraint on the weights of the classifiers. As the proposed
cost function is non-convex thus hard to solve, convex relaxation techniques
and novel approximations are employed to obtain a numerically efficient
solution. Sparsity term of cost function allows trade-off between accuracy and
testing time when needed. The efficiency of SDWEC was tested on 11 datasets and
compared with the state-of-the art classifier ensemble methods. The results
show that SDWEC provides better or similar accuracy levels using fewer
classifiers and reduces testing time for ensemble.


title:
Te Doped Indium (II) Selenide Photocatalyst for Water Splitting: A First
  Principles Study

abstract:
  Graphene like 2D materials have attracted tremendous attention in the field
of photocatalytic water splitting. Indium Selenide (InSe) is one such potential
material. Here, we report the effect of Tellurium on InSe monolayer for the
photocatalytic water splitting by means of density functional calculations. The
calculated bandgaps fall within the visible region of the solar spectrum
indicating these materials could absorb a significant amount of solar light.
Density of states calculations show that the covalent character is present
between the atoms which is typical for the layered system. The band alignment
with respect to redox potentials show that Te doped InSe is more favorable for
the hydrogen reduction reaction than the pristine InSe monolayer. Our overall
results show that Te substitution improves the photocatalytic water splitting
ability in InSe monolayer.


title:
Manufacturing and testing a thin glass mirror shell with piezoelectric
  active control

abstract:
  Optics for future X-ray telescopes will be characterized by very large
aperture and focal length, and will be made of lightweight materials like glass
or silicon in order to keep the total mass within acceptable limits. Optical
modules based on thin slumped glass foils are being developed at various
institutes, aiming at improving the angular resolution to a few arcsec HEW.
Thin mirrors are prone to deform, so they require a careful integration to
avoid deformations and even correct forming errors. On the other hand, this
offers the opportunity to actively correct the residual deformation: a viable
possibility to improve the mirror figure is the application of piezoelectric
actuators onto the non-optical side of the mirrors, and several groups are
already at work on this approach. The concept we are developing consists of
actively integrating thin glass foils with piezoelectric patches, fed by
voltages driven by the feedback provided by X-rays. The actuators are
commercial components, while the tension signals are carried by a printed
circuit obtained by photolithography, and the driving electronic is a
multi-channel low power consumption voltage supply developed in-house. Finally,
the shape detection and the consequent voltage signal to be provided to the
piezoelectric array are determined in X-rays, in intra-focal setup at the XACT
facility at INAF/OAPA. In this work, we describe the manufacturing steps to
obtain a first active mirror prototype and the very first test performed in
X-rays.


title: Multipoint entanglement in disordered systems

abstract:
  We develop an approach to characterize excited states of disordered many-body
systems using spatially resolved structures of entanglement. We show that the
behavior of the mutual information (MI) between two parties of a many-body
system can signal a qualitative difference between thermal and localized phases
-- MI is finite in insulators while it approaches zero in the thermodynamic
limit in the ergodic phase. Related quantities, such as the recently introduced
Codification Volume (CV), are shown to be suitable to quantify the correlation
length of the system. These ideas are illustrated using prototypical
non-interacting wavefunctions of localized and extended particles and then
applied to characterize states of strongly excited interacting spin chains. We
especially focus on evolution of spatial structure of quantum information
between high temperature diffusive and many-body localized phases believed to
exist in these models. We study MI as a function of disorder strength both
averaged over the eigenstates and in time-evolved product states drawn from
continuously deformed family of initial states realizable experimentally. As
expected, spectral and time-evolved averages coincide inside the ergodic phase
and differ significantly outside. We also highlight dispersion among the
initial states \emph{within} the localized phase -- some of these show
considerable generation and delocalization of quantum information.


title: The complex dynamics of products and its asymptotic properties

abstract:
  We analyse global export data within the Economic Complexity framework. We
couple the new economic dimension Complexity, which captures how sophisticated
products are, with an index called logPRODY, a measure of the income of the
respective exporters. Products' aggregate motion is treated as a 2-dimensional
dynamical system in the Complexity-logPRODY plane. We find that this motion can
be explained by a quantitative model involving the competition on the markets,
that can be mapped as a scalar field on the Complexity-logPRODY plane and acts
in a way akin to a potential. This explains the movement of products towards
areas of the plane in which the competition is higher. We analyse market
composition in more detail, finding that for most products it tends, over time,
to a characteristic configuration, which depends on the Complexity of the
products. This market configuration, which we called asymptotic, is
characterized by higher levels of competition.


title: SU(2N_F) symmetry of QCD at high temperature and its implications

abstract:
  If above a critical temperature not only the SU(N_F)_L \times SU(N_F)_R
chiral symmetry of QCD but also the U(1)_A symmetry is restored, then the
actual symmetry of the QCD correlation functions and observables is SU(2N_F).
Such a symmetry prohibits existence of deconfined quarks and gluons. Hence QCD
at high temperature is also in the confining regime and elementary objects are
SU(2N_F) symmetric "hadrons" with not yet known properties.


title: Universal measure for Poncelet-type theorems

abstract:
  We give a simple proof of the Emch closing theorem by introducing a new
invariant measure on the circle. Special cases of that measures are well-known
and have been used in the literature to prove Poncelet's and Zigzag theorems.
Some further generalizations are also obtained by applying the new measure.


title: Very Deep Convolutional Neural Networks for Robust Speech Recognition

abstract:
  This paper describes the extension and optimization of our previous work on
very deep convolutional neural networks (CNNs) for effective recognition of
noisy speech in the Aurora 4 task. The appropriate number of convolutional
layers, the sizes of the filters, pooling operations and input feature maps are
all modified: the filter and pooling sizes are reduced and dimensions of input
feature maps are extended to allow adding more convolutional layers.
Furthermore appropriate input padding and input feature map selection
strategies are developed. In addition, an adaptation framework using joint
training of very deep CNN with auxiliary features i-vector and fMLLR features
is developed. These modifications give substantial word error rate reductions
over the standard CNN used as baseline. Finally the very deep CNN is combined
with an LSTM-RNN acoustic model and it is shown that state-level weighted log
likelihood score combination in a joint acoustic model decoding scheme is very
effective. On the Aurora 4 task, the very deep CNN achieves a WER of 8.81%,
further 7.99% with auxiliary feature joint training, and 7.09% with LSTM-RNN
joint decoding.


title: On the wellposedness of the KdV equation on the space of pseudomeasures

abstract:
  In this paper we prove a wellposedness result of the KdV equation on the
space of periodic pseudo-measures, also referred to as the Fourier Lebesgue
space $\mathscr{F}\ell^{\infty}(\mathbb{T},\mathbb{R})$, where
$\mathscr{F}\ell^{\infty}(\mathbb{T},\mathbb{R})$ is endowed with the weak*
topology. Actually, it holds on any weighted Fourier Lebesgue space
$\mathscr{F}\ell^{s,\infty}(\mathbb{T},\mathbb{R})$ with $-1/2 < s \le 0$ and
improves on a wellposedness result of Bourgain for small Borel measures as
initial data. A key ingredient of the proof is a characterization for a
distribution $q$ in the Sobolev space $H^{-1}(\mathbb{T},\mathbb{R})$ to be in
$\mathscr{F}\ell^{\infty}(\mathbb{T},\mathbb{R})$ in terms of asymptotic
behavior of spectral quantities of the Hill operator $-\partial_{x}^{2} + q$.
In addition, wellposedness results for the KdV equation on the Wiener algebra
are proved.


title:
Deep Learning Algorithms for Signal Recognition in Long Perimeter
  Monitoring Distributed Fiber Optic Sensors

abstract:
  In this paper, we show an approach to build deep learning algorithms for
recognizing signals in distributed fiber optic monitoring and security systems
for long perimeters. Synthesizing such detection algorithms poses a non-trivial
research and development challenge, because these systems face stringent error
(type I and II) requirements and operate in difficult signal-jamming
environments, with intensive signal-like jamming and a variety of changing
possible signal portraits of possible recognized events. To address these
issues, we have developed a twolevel event detection architecture, where the
primary classifier is based on an ensemble of deep convolutional networks, can
recognize 7 classes of signals and receives time-space data frames as input.
Using real-life data, we have shown that the applied methods result in
efficient and robust multiclass detection algorithms that have a high degree of
adaptability.


title: The Quadrahelix: A Nearly Perfect Loop of Tetrahedra

abstract:
  In 1958, S. \'Swierczkowski proved that there cannot be a closed loop of
congruent interior-disjoint regular tetrahedra that meet face-to-face. Such
closed loops do exist for the other four regular polyhedra. It has been
conjectured that, for any positive \epsilon, there is a tetrahedral loop such
that its difference from a closed loop is less than \epsilon. We prove this
conjecture by presenting a very simple pattern that can generate loops of
tetrahedra in a rhomboid shape having arbitrarily small gap. Moreover,
computations provide explicit examples where the error is under $10^{-100}$ or
$10^{-10^{6}}$. The explicit examples arise from a certain Diophantine relation
whose solutions can be found through continued fractions; for more complicated
patterns a lattice reduction technique is needed.


title: Phases of Attractive Fermi Gases in Synthetic Dimensions

abstract:
  A novel way to produce quantum Hall ribbons in a cold atomic system is to use
M hyperfine states of atoms in a 1D optical lattice to mimic an additional
"synthetic dimension". A notable aspect here is that the SU(M) symmetric
interaction between atoms manifests as "infinite ranged" along the synthetic
dimension. We study the many body physics of fermions with attractive
interactions in this system. We use a combination of analytical field theoretic
and numerical density matrix renormalization group (DMRG) methods to reveal the
rich ground state phase diagram of the system, including novel phases such as
squished baryon fluids. Remarkably, changing the parameters entails unusual
crossovers and transitions, e. g., we show that increasing the magnetic field
(that produces the Hall effect) may convert a "ferrometallic" state at low
fields to a "squished baryon superfluid" (with algebraic pairing correlations)
at high fields. We also show that this system provides a unique opportunity to
study quantum phase separation in a multiflavor ultracold fermionic system.


title: The bullet problem with discrete speeds

abstract:
  Bullets are fired, one per second, with independent speeds sampled uniformly
from a discrete set. Collisions result in mutual annihilation. We show that the
second fastest bullet survives with positive probability, while a slowest
bullet does not. This also holds for exponential spacings between firing times,
and for certain non-uniform measures that place less probability on the second
fastest bullet. Our results provide new insights into a two-sided version of
the bullet process known to physicists as ballistic annihilation.


title:
The z~6 Luminosity Function Fainter than -15 mag from the Hubble
  Frontier Fields: The Impact of Magnification Uncertainties

abstract:
  We use the largest sample of z~6 galaxies to date from the first four Hubble
Frontier Fields clusters to set constraints on the shape of the z~6 luminosity
functions (LFs) to fainter than Muv=-14 mag. We quantify, for the first time,
the impact of magnification uncertainties on LF results and thus provide more
realistic constraints than other recent work. Our simulations reveal that for
the highly-magnified sources the systematic uncertainties can become extremely
large fainter than -14 mag, reaching several orders of magnitude at 95%
confidence at ~-12 mag. Our new forward-modeling formalism incorporates the
impact of magnification uncertainties into the LF results by exploiting the
availability of many independent magnification models for the same cluster. One
public magnification model is used to construct a mock high-redshift galaxy
sample that is then analyzed using the other magnification models to construct
a LF. Large systematic errors occur at high magnifications (mu>30) because of
differences between the models. The volume densities we derive for faint (>-17
mag) sources are ~3-4x lower than one recent report and give a faint-end slope
alpha=-1.92+/-0.04, which is 3.0-3.5sigma shallower (including or not including
the size uncertainties, respectively). We introduce a new curvature parameter
delta to model the faint end of the LF and demonstrate that the observations
permit (at 68% confidence) a turn-over at z~6 in the range -15.3 to -14.2 mag,
depending on the assumed lensing model. The present consideration of
magnification errors and new size determinations raise doubts about previous
reports regarding the form of the LF at >-14 mag. We discuss the implications
of our turn-over constraints in the context of recent theoretical predictions.


title: Whittaker supports for representations of reductive groups

abstract:
  Let $F$ be either $\mathbb{R}$ or a finite extension of $\mathbb{Q}_p$, and
let $G$ be a finite central extension of the group of $F$-points of a reductive
group defined over $F$. Also let $\pi$ be a smooth representation of $G$
(Frechet of moderate growth if $F=\mathbb{R}$). For each nilpotent orbit
$\mathcal{O}$ we consider a certain Whittaker quotient $\pi_{\mathcal{O}}$ of
$\pi$. We define the Whittaker support WS$(\pi)$ to be the set of maximal
$\mathcal{O}$ among those for which $\pi_{\mathcal{O}}\neq 0$.
  In this paper we prove that all $\mathcal{O}\in\mathrm{WS}(\pi)$ are
quasi-admissible nilpotent orbits, generalizing some of the results in
[Moe96,JLS16]. If $F$ is $p$-adic and $\pi$ is quasi-cuspidal then we show that
all $\mathcal{O}\in\mathrm{WS}(\pi)$ are $F$-distinguished, i.e. do not
intersect the Lie algebra of any proper Levi subgroup of $G$ defined over $F$.
  We also give an adaptation of our argument to automorphic representations,
generalizing some results from [GRS03,Shen16,JLS16,Cai] and confirming some
conjectures from [Ginz06].
  Our methods are a synergy of the methods of the above-mentioned papers, and
of our preceding paper [GGS17].


title: Determining the vibrations between sensor and sample in SQUID microscopy

abstract:
  Vibrations can cause noise in scanning probe microscopies. Relative
vibrations between the scanning sensor and the sample are important but can be
more difficult to determine than absolute vibrations or vibrations relative to
the laboratory. We measure the noise spectral density in a scanning SQUID
microscope as a function of position near a localized source of magnetic field,
and show that we can determine the spectra of all three components of the
relative sensor-sample vibrations. This method is a powerful tool for
diagnosing vibrational noise in scanning microscopies.


title: New methods for old spaces: synthetic differential geometry

abstract:
  Survey talk on certain aspects of the subject, stressing the neighbor
relation as a basic notion in differential geometry.


title:
Iterative Null-space Projection Method with Adaptive Thresholding in
  Sparse Signal Recovery and Matrix Completion

abstract:
  Adaptive thresholding methods have proved to yield high SNRs and fast
convergence in finding the solution to the Compressed Sensing (CS) problems.
Recently, it was observed that the robustness of a class of iterative sparse
recovery algorithms such as Iterative Method with Adaptive Thresholding (IMAT)
has outperformed the well-known LASSO algorithm in terms of reconstruction
quality, convergence speed, and the sensitivity to the noise. In this paper, we
introduce a new method towards solving the CS problem. The logic of this method
is based on iterative projections of the thresholded signal onto the null-space
of the sensing matrix. The thresholding is carried out by recovering the
support of the desired signal by projection on thresholding subspaces. The
simulations reveal that the proposed method has the capability of yielding
noticeable output SNR values with about as many samples as twice the sparsity
number, while other methods fail to recover the signals when approaching the
algebraic bound for the number of samples required. The computational
complexity of our method is also comparable to other methods as observed in the
simulations. We have also extended our Algorithm to Matrix Completion (MC)
scenarios and compared its efficiency to other well-reputed approaches for MC
in the literature.


title: Radiative $h_{c/b}$ decays to $\eta$ or $\eta^\prime$

abstract:
  Motivated by recent measurements of the radiative decay rates of the
\emph{P}-wave spin singlet charmonium $h_c$ to the light meson $\eta$ or
$\eta^\prime$ by the BESIII Collaboration, we investigate the decay rates of
these channels at order $\alpha \alpha_s^4$. The photon is radiated mainly from
charm quark pairs in the lowest order Feynman diagrams, since the diagrams
where a photon radiated from light quarks are suppressed by $\alpha_s$ or the
relative charm quark velocity $v$, due to Charge parity conservation. The form
factors of two gluons to $\eta$ or $\eta^\prime$ are employed, which are the
major mechanism for $\eta$ and $\eta^\prime$ productions. $\eta(\eta^\prime)$
is treated as a light cone object when we consider that the parent charmonium
mass is much heavier than that of the final light meson. We obtain the
branching ratio ${\cal B}(h_c\to \gamma\eta^\prime) =
(1.94^{+0.70}_{-0.51})\times 10^{-3}$ in the nonrelativistic QCD approach,
which is in agreement with the BESIII measurement. The prediction of the
branching ratio of $h_c\to \gamma\eta$ is also within the range of experimental
error after including the larger uncertainty of the total decay width
$\Gamma_{h_c}$. The applications of these formulae to the radiative decays to
$\eta(\eta^\prime)$ of the \emph{P}-wave spin singlet bottomonium $h_b(nP)$ are
presented. These studies will shed some light on the $\eta - \eta^\prime$
mixing effects, the flavor SU(3) symmetry breaking, as well as the
nonperturbative dynamics of charmonium and bottomonium.


title: Flocking Virtual Machines in Quest for Responsive IoT Cloud Services

abstract:
  We propose Flock; a simple and scalable protocol that enables live migration
of Virtual Machines (VMs) across heterogeneous edge and conventional cloud
platforms to improve the responsiveness of cloud services. Flock is designed
with properties that are suitable for the use cases of the Internet of Things
(IoT). We describe the properties of regularized latency measurements that
Flock can use for asynchronous and autonomous migration decisions. Such
decisions allow communicating VMs to follow a flocking-like behavior that
consists of three simple rules: separation, alignment, and cohesion. Using game
theory, we derive analytical bounds on Flock's Price of Anarchy (PoA), and
prove that flocking VMs converge to a Nash Equilibrium while settling in the
best possible cloud platforms. We verify the effectiveness of Flock through
simulations and discuss how its generic objective can simply be tweaked to
achieve other objectives, such as cloud load balancing and energy consumption
minimization.


title:
Conditional Visualization for Statistical Models: An Introduction to the
  condvis Package in R

abstract:
  The condvis package is for interactive visualization of sections in data
space, showing fitted models on the section, and observed data near the
section. The primary goal is the interpretation of complex models, and showing
how the observed data support the fitted model. There is a video accompaniment
to this paper available at https://www.youtube.com/watch?v=rKFq7xwgdX0. This is
a preprint version of an article to appear in the Journal of Statistical
Software.


title: Deep Feature Consistent Variational Autoencoder

abstract:
  We present a novel method for constructing Variational Autoencoder (VAE).
Instead of using pixel-by-pixel loss, we enforce deep feature consistency
between the input and the output of a VAE, which ensures the VAE's output to
preserve the spatial correlation characteristics of the input, thus leading the
output to have a more natural visual appearance and better perceptual quality.
Based on recent deep learning works such as style transfer, we employ a
pre-trained deep convolutional neural network (CNN) and use its hidden features
to define a feature perceptual loss for VAE training. Evaluated on the CelebA
face dataset, we show that our model produces better results than other methods
in the literature. We also show that our method can produce latent vectors that
can capture the semantic information of face expressions and can be used to
achieve state-of-the-art performance in facial attribute prediction.


title:
On the analytical properties of the magneto-conductivity in the case of
  presence of stable open electron trajectories on a complex Fermi surface

abstract:
  We consider the electric conductivity in normal metals in presence of a
strong magnetic field. It is assumed here that the Fermi surface of a metal has
rather complicated form such that different types of quasiclassical electron
trajectories can appear on the Fermi level for different directions of B. The
effects we consider are connected with the existence of regular (stable) open
electron trajectories which arise in general on complicated Fermi surfaces. The
trajectories of this type have a nice geometric description and represent
quasiperiodic lines with a fixed mean direction in the p-space. Being stable
geometric objects, the trajectories of this kind exist for some open regions in
the space of directions of B, which can be represented by "Stability Zones" on
the unit sphere. The main goal of the paper is to give a description of the
analytical behavior of conductivity in the Stability Zones, which demonstrates
in general rather nontrivial properties.


title: The evolution of sleep is inevitable

abstract:
  There are two contrasting explanations of sleep: as a proximate, essential
physiological function or as an adaptive state of inactivity and these
hypotheses remain widely debated. To investigate the adaptive significance of
sleep, we develop an evolutionary argument formulated as a tractable partial
differential equation model. We allow demographic parameters such as birth and
mortality rates to vary through time in both safe and vulnerable sleeping
environments. From this model we analytically calculate population growth rate
(fitness) for sleeping and non-sleeping strategies. We find that, in a
temporally heterogeneous environment, sleeping always achieves a higher fitness
than not sleeping. As organisms do not exist in constant environments, we
conclude that the evolution of sleep is inevitable.


title: CO$_2$ Infrared Phonon Modes in Interstellar Ice Mixtures

abstract:
  CO$_2$ ice is an important reservoir of carbon and oxygen in star and planet
forming regions. Together with water and CO, CO$_2$ sets the physical and
chemical characteristics of interstellar icy grain mantles, including
desorption and diffusion energies for other ice constituents. A detailed
understanding of CO$_2$ ice spectroscopy is a prerequisite to characterize
CO$_2$ interactions with other volatiles both in interstellar ices and in
laboratory experiments of interstellar ice analogs. We report laboratory
spectra of the CO$_2$ longitudinal optical (LO) phonon mode in pure CO$_2$ ice
and in CO$_2$ ice mixtures with H$_2$O, CO, O$_2$ components. We show that the
LO phonon mode position is sensitive to the mixing ratio of various ice
components of astronomical interest. In the era of JWST, this characteristic
could be used to constrain interstellar ice compositions and morphologies. More
immediately, LO phonon mode spectroscopy provides a sensitive probe of ice
mixing in the laboratory and should thus enable diffusion measurements with
higher precision than has been previously possible.


title: Many-body theory of magneto-elasticity in one dimension

abstract:
  We construct a many-body theory of magneto-elasticity in one dimension and
show that the dynamical correlation functions of the quantum magnet, connecting
the spins with phonons, involve all energy scales. Accounting for all magnetic
states non-perturbatively via the exact diagonalisation techniques of Bethe
ansatz, we find that the renormalisation of the phonon velocity is a
non-monotonous function of the external magnetic field and identify a new
mechanism for attenuation of phonons - via hybridisation with the continuum of
excitations at high energy. We conduct ultrasonic measurements on a
high-quality single crystal of the frustrated spin-1/2 Heisenberg
antiferromagnet $\textrm{Cs}_{2}\textrm{CuCl}_{4}$ in its one-dimensional
regime and confirm the theoretical predictions, demonstrating that ultrasound
can be used as a powerful probe of strong correlations in one dimension.


title: Comparing the Locking Threshold for Rings and Chains of Oscillators

abstract:
  We present a case study of how topology can affect synchronization.
Specifically, we consider arrays of phase oscillators coupled in a ring or a
chain topology. Each ring is perfectly matched to a chain with the same initial
conditions and the same random natural frequencies. The only difference is
their boundary conditions: periodic for a ring, and open for a chain. For both
topologies, stable phase-locked states exist if and only if the spread or
"width" of the natural frequencies is smaller than a critical value called the
locking threshold (which depends on the boundary conditions and the particular
realization of the frequencies). The central question is whether a ring
synchronizes more readily than a chain. We show that it usually does, but not
always. Rigorous bounds are derived for the ratio between the locking
thresholds of a ring and its matched chain, for a variant of the Kuramoto model
that also includes a wider family of models.


title: Roman domination excellent graphs: trees

abstract:
  A Roman dominating function (RDF) on a graph $G = (V, E)$ is a labeling $f :
V \rightarrow \{0, 1, 2\}$ such that every vertex with label $0$ has a neighbor
with label $2$. The weight of $f$ is the value $f(V) = \Sigma_{v\in V} f(v)$.
The Roman domination number, $\gamma_R(G)$, of $G$ is the minimum weight of an
RDF on $G$. An RDF of minimum weight is called a $\gamma_R$-function. A graph G
is said to be $\gamma_R$-excellent if for each vertex $x \in V$ there is a
$\gamma_R$-function $h_x$ on $G$ with $h_x(x) \not = 0$. We present a
constructive characterization of $\gamma_R$-excellent trees using labelings. A
graph $G$ is said to be in class $UVR$ if $\gamma(G-v) = \gamma (G)$ for each
$v \in V$, where $\gamma(G)$ is the domination number of $G$. We show that each
tree in $UVR$ is $\gamma_R$-excellent.


title: Khovanskii bases, higher rank valuations and tropical geometry

abstract:
  Given a finitely generated algebra $A$, it is a fundamental question whether
$A$ has a full rank discrete (Krull) valuation $\mathfrak{v}$ with finitely
generated value semigroup. We give a necessary and sufficient condition for
this, in terms of tropical geometry of $A$. In the course of this we introduce
the notion of a Khovanskii basis for $(A, \mathfrak{v})$ which provides a
framework for far extending Gr\"obner theory on polynomial algebras to general
finitely generated algebras. In particular, this makes a direct connection
between the theory of Newton-Okounkov bodies and tropical geometry, and toric
degenerations arising in both contexts. We also construct an associated
compactification of $Spec(A)$. Our approach includes many familiar examples
such as the Gel'fand-Zetlin degenerations of coordinate rings of flag varieties
as well as wonderful compactifications of reductive groups. We expect that many
examples coming from cluster algebras naturally fit into our framework.


title: Classical and strongly classical 2-absorbing second submodules

abstract:
  In this paper, we will introduce the concept of classical (resp. strongly
classical) 2-absorbing second submodules of modules over a commutative ring as
a generalization of 2-absorbing (resp. strongly 2-absorbing) second submodules
and investigate some basic properties of these classes of modules.


title: Polynomial Time Algorithms for Bichromatic Problems

abstract:
  In this article, we consider a collection of geometric problems involving
points colored by two colors (red and blue), referred to as bichromatic
problems. The motivation behind studying these problems is two fold; (i) these
problems appear naturally and frequently in the fields like Machine learning,
Data mining, and so on, and (ii) we are interested in extending the algorithms
and techniques for single point set (monochromatic) problems to bichromatic
case. For all the problems considered in this paper, we design low polynomial
time exact algorithms. These algorithms are based on novel techniques which
might be of independent interest.


title:
Alkali doping of graphene: the crucial role of high temperature
  annealing

abstract:
  The doping efficiency of lithium deposited at cryogenic temperatures on
epitaxial and CVD monolayer graphene has been investigated under ultra-high
vacuum conditions. Change of charge carrier density was monitored by gate
voltage shift of the Dirac point and by Hall measurements, in low and high
doping regimes. It was found that pre-annealing the graphene greatly enhanced
the maximum levels of doping that could be achieved: doping saturated at
$\Delta n = 2\times 10^{13}$ e$^-$/cm$^2$ without annealing, independent of
sample type or previous processing; after a 900 K anneal, the saturated doping
rose one order of magnitude to $\Delta n = 2\times 10^{14}$ e$^-$/cm$^2$.


title: Eigenstate Thermalization Hypothesis in Conformal Field Theory

abstract:
  We investigate the eigenstate thermalization hypothesis (ETH) in d+1
dimensional conformal field theories by studying reduced density matrices in
energy eigenstates. We show that if local probes of high energy primary
eigenstates satisfy ETH, then any finite energy observable with support on a
subsystem of finite size satisfies ETH. In two dimensions, we discover that if
ETH holds locally, the finite size reduced density matrix of states created by
heavy primary operators is well-approximated by a projection to the Virasoro
identity block.

categories: hep-th cond-mat.stat-mech cond-mat.str-el quant-ph


title:
Possibility of Combining Ferroelectricity and Rashba-like spin splitting
  in Monolayers of 1T-type Transition-Metal Dichalcogenides MX2

abstract:
  First-principles calculations were carried out to explore the possible
coupling between spin-polarized electronic states and ferroelectric
polarization in monolayers of transition-metal dichalcogenides MX 2 (M = Mo, W;
X = S, Se, Te) with distorted octahedrally coordinated 1T structures.For d^2
metal ions, two competing metal clustering effects can take place, where metal
ions are arranged in trimers or zigzag chains. Among these, the former
structural distortion comes along with an improper ferroelectric phase which
persists in the monolayer limit. Switchable Rashba-like spin-polarization
features are predicted in the trimerized polytype, which can be permanently
tuned by acting on its ferroelectric properties. The polar trimerized structure
is found to be stable for 1T-MoS 2 only, while the nonpolar polytype with
zigzag metal clustering is predicted to stabilize for other transition-metal
dichalcogenides with d 2 metal ions.


title:
A neutrino mixing model based on an $A_4\times Z_3\times Z_4$ flavour
  symmetry

abstract:
  A model of a neutrino mixing with an $A_4\times Z_3\times Z_4$ flavour
symmetry is suggested. In addition to the standard model fields, the present
model contains six new fields which transform under different representations
of $A_4\times Z_3\times Z_4$. The model is constructed to slightly deviate from
a tri-bi-maximal model in agreement with the current experimental data, thus,
all analysis can be done in the base of the perturbation method. Within this
model, as an application, a relation between the mixing angles ($\theta_{12},
\theta_{23}, \theta_{13}$) and the Dirac CP-violation phase ($\delta_{CP}$) is
established. This relation allows a prediction of $\delta_{CP}$ and the
Jarlskog parameter ($J_{CP}$). The predicted value $\delta_{CP}$ is in the
1$\sigma$ region of the global fit for both the normal- and inverse neutrino
mass ordering and gives $J_{CP}$ to be within the bound $|J_{CP}|\leq 0.04$.
For an illustration, the model is checked numerically and gives values of the
neutrino masses (of the order of 0.1 eV) and the mixing angle $\theta_{13}$
(about $9^\circ$) very close to the current experimental data.


title: The possible existence of Pop III NS-BH binary and its detectability

abstract:
  In the population synthesis simulations of Pop III stars, many BH (Black
Hole)-BH binaries with merger time less than the age of the Universe
$(\tau_{\rm H})$ are formed, while NS (Neutron Star)-BH binaries are not. The
reason is that Pop III stars have no metal so that no mass loss is expected.
Then, in the final supernova explosion to NS, much mass is lost so that the
semi major axis becomes too large for Pop III NS-BH binaries to merge within
$\tau_{\rm H}$. However it is almost established that the kick velocity of the
order of $200-500{\rm~ km~s^{-1}}$ exists for NS from the observation of the
proper motion of the pulsar. Therefore, the semi major axis of the half of
NS-BH binaries can be smaller than that of the previous argument for Pop III
NS-BH binaries to decrease the merging time. We perform population synthesis
Monte Carlo simulations of Pop III NS-BH binaries including the kick of NS and
find that the event rate of Pop III NS-BH merger rate is $\sim 1 {\rm Gpc^{-3}
yr^{-1}}$. This suggests that there is a good chance of the detection of Pop
III NS-BH mergers in O2 of Advanced LIGO and Advanced Virgo from this autumn.


title:
A two-phase strategy for control constrained elliptic optimal control
  problems

abstract:
  Elliptic optimal control problems with pointwise box constraints on the
control (EOCP) are considered. To solve EOCP, the primal-dual active set (PDAS)
method, which is a special semismooth Newton (SSN) method, used to be a
priority in consideration of their locally superlinear convergence. However, in
general solving the Newton equations is expensive, especially when the
discretization is in a fine level. Motivated by the success of applying
alternating direction method of multipliers (ADMM) for solving large scale
convex minimization problem in finite dimension, it is reasonable to extend the
ADMM to solve EOCP. To numerically solve EOCP, the finite element (FE) method
is used for discretization. Then, a two-phase strategy is presented to solve
discretized problems. In Phase-I, an inexact heterogeneous ADMM (ihADMM) is
proposed with the aim of solving discretized problems to moderate accuracy or
using it to generate a reasonably good initial point to warm-start Phase-II.
Different from the classical ADMM, our ihADMM adopts two different weighted
inner product to define the augmented Lagrangian function in two subproblems,
respectively. Benefiting from such different weighted techniques, two
subproblems of ihADMM can be efficiently implemented. Furthermore, theoretical
results on the global convergence as well as the iteration complexity results
$o(1/k)$ for ihADMM are given. In Phase-II, in order to obtain more accurate
solution, the primal-dual active set (PDAS) method is used as a postprocessor
of the ihADMM. Numerical results show that the ihADMM and the two-phase
strategy are highly efficient.


title:
Plug-and-Play CNN for Crowd Motion Analysis: An Application in Abnormal
  Event Detection

abstract:
  Most of the crowd abnormal event detection methods rely on complex
hand-crafted features to represent the crowd motion and appearance.
Convolutional Neural Networks (CNN) have shown to be a powerful tool with
excellent representational capacities, which can leverage the need for
hand-crafted features. In this paper, we show that keeping track of the changes
in the CNN feature across time can facilitate capturing the local abnormality.
We specifically propose a novel measure-based method which allows measuring the
local abnormality in a video by combining semantic information (inherited from
existing CNN models) with low-level Optical-Flow. One of the advantage of this
method is that it can be used without the fine-tuning costs. The proposed
method is validated on challenging abnormality detection datasets and the
results show the superiority of our method compared to the state-of-the-art
methods.


title:
Non-linear charge and energy dynamics of an adiabatically driven
  interacting quantum dot

abstract:
  We formulate a general theory to study the time-dependent charge and energy
transport of an adiabatically driven interacting quantum dot in contact to a
reservoir for arbitrary amplitudes of the driving potential. We study within
this framework the Anderson impurity model with a local ac gate voltage. We
show that the exact adiabatic quantum dynamics of this system is fully
determined by the behavior of the charge susceptibility of the frozen problem.
At $T=0$, we evaluate the dynamic response functions with the numerical
renormalization group (NRG). The time-resolved heat production exhibits a
pronounced feature described by an instantaneous Joule law characterized by an
universal resistance quantum $R_0=h/(2 e^2)$ for each spin channel. We show
that this law holds in non-interacting as well as in the interacting system and
also when the system is spin-polarized. In addition, in the presence of a
static magnetic field, the interplay between many-body interactions and spin
polarization leads to a non-trivial energy exchange between electrons with
different spin components.


title:
Can Occipital Alpha Neurofeedback Influence LTRCs and Deterministic ERPs
  without Critical Branching?

abstract:
  Critical branching is a theoretical interaction in-between simple units, such
as neuronal elements of the human brain. Zhigalov, Kaplan, and Palva (2016,
Clin. Neurophysiol., 127(8), 2882-2889) revealed that neurofeedback flash
stimulation locked to the phase of high-amplitude occipital alpha influences
stimulus-locked occipital averages in the alpha-band. This feedback also
influences the power scaling of long-range temporal correlations in alpha-band
amplitude fluctuations. Seemingly, neurofeedback influences critical branching
alongside there being an interaction between ongoing neuronal activity and
evoked responses. However, the causal relations between these neuronal
long-range temporal correlations, sustained attention, and any avalanche
dynamics are called into question. Further, uncorrected concerns include false
discovery rate and an objective mathematical error in the precedent (Palva et
al., 2013, Proc. Nat. Acad. Sci. U.S.A., 110(9), 3585-3590). An alternative set
of illustrative mathematical principles offers a preliminary fit to the effects
in the data. That is, neurofeedback influences the deterministic contribution
to the single-trial event-related potentials, which each flash evokes,
separately from the oscillatory alpha gain that those flashes cause.
Accordingly, distinct principles of this neurofeedback-related exponential
occipital oscillatory alpha gain and deterministic event-related potential
generation produce micro-behaviours with macroscale consequences: neurofeedback
causally influences power-scaling of long-range temporal correlations without
critical branching.


title:
Nearest-neighbour antiferromagnetic interaction as a limiting factor for
  critical temperature in model DMS system

abstract:
  In numerous diluted magnetic semiconductor (DMS) systems, the competition
takes place between the short-range antiferromagnetic (AF) superexchange
interactions and the long-range Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling
mediated by the charge carriers. Such a situation strongly influences the
critical temperature, the maximization of which constitutes a challenging task
in DMS physics and technology. The aim of the paper is to discuss theoretically
the limiting effect of AF interactions between nearest-neighbour magnetic ions
on the stability of inhomogeneous ferromagnetic state in a model diluted
magnetic system reflecting some crucial features of DMS.
  The modified molecular field-based model is constructed to account for the
magnetic inhomogeneity. The behavior of the system is studied as a function of
the ratio of superexchange integral to effective ferromagnetic coupling
integral, including the possibility of clustering/anticlustering tendency for
the magnetic ions. The ground state of the system is analysed. The critical
temperature is found to change non-monotonically with the concentration of
magnetic ions and decrease severely for larger concentrations. The behavior of
the system significantly differs from the predictions of the usual homogeneous
mean-field model. Brief comparison with selected experimental results for
(Zn,Mn)Te is provided.


title: Syntactic Structures and Code Parameters

abstract:
  We assign binary and ternary error-correcting codes to the data of syntactic
structures of world languages and we study the distribution of code points in
the space of code parameters. We show that, while most codes populate the lower
region approximating a superposition of Thomae functions, there is a
substantial presence of codes above the Gilbert-Varshamov bound and even above
the asymptotic bound and the Plotkin bound. We investigate the dynamics induced
on the space of code parameters by spin glass models of language change, and
show that, in the presence of entailment relations between syntactic parameters
the dynamics can sometimes improve the code. For large sets of languages and
syntactic data, one can gain information on the spin glass dynamics from the
induced dynamics in the space of code parameters.


title:
Volatility Inference and Return Dependencies in Stochastic Volatility
  Models

abstract:
  Stochastic volatility models describe stock returns $r_t$ as driven by an
unobserved process capturing the random dynamics of volatility $v_t$. The
present paper quantifies how much information about volatility $v_t$ and future
stock returns can be inferred from past returns in stochastic volatility models
in terms of Shannon's mutual information.


title: $X$-torsion and universal groups

abstract:
  For a set $X\subseteq \mathbb{N}$, we define the $X$-torsion of a group $G$
to be all elements $g\in G$ with $g^{n}=e$ for some $n\in X$. With $X$
recursively enumerable, we give two independent proofs (group-theoretic, and
model-theoretic) that there exists a universal finitely presented
$X$-torsion-free group; one which contains all finitely presented
$X$-torsion-free groups. We also show that, if $X$ is recursively enumerable,
then the set of finite presentations of $X$-torsion-free groups is
$\Pi_{2}^{0}$-complete in Kleene's arithmetic hierarchy.


title:
Strong electronic interaction and multiple quantum Hall ferromagnetic
  phases in trilayer graphene

abstract:
  There is an increasing interest in the electronic properties of few layer
graphene as it offers a platform to study electronic interactions because the
dispersion of bands can be tuned with number and stacking of layers in
combination with electric field. However, electronic interaction becomes
important only in very clean devices and so far the trilayer graphene
experiments are understood within non-interacting electron picture. Here, we
report evidence of strong electronic interactions and quantum Hall
ferromagnetism (QHF) seen in ABA trilayer graphene (ABA-TLG). Due to high
mobility $\sim$500,000 cm$^2$V$^{-1}$s$^{-1}$ in our device compared to
previous studies, we find all symmetry broken states and that Landau Level (LL)
gaps are enhanced by interactions; an aspect explained by our self-consistent
Hartree-Fock (H-F) calculations. Moreover, we observe hysteresis as a function
of filling factor ($\nu$) and spikes in the longitudinal resistance which,
together, signal the formation of QHF states at low magnetic field.


title: Fast Bayesian inference of optical trap stiffness and particle diffusion

abstract:
  Bayesian inference provides a principled way of estimating the parameters of
a stochastic process that is observed discretely in time. The overdamped
Brownian motion of a particle confined in an optical trap is generally modelled
by the Ornstein-Uhlenbeck process and can be observed directly in experiment.
Here we present Bayesian methods for inferring the parameters of this process,
the trap stiffness and the particle diffusion coefficient, that use exact
likelihoods and sufficient statistics to arrive at simple expressions for the
maximum a posteriori estimates. This obviates the need for Monte Carlo sampling
and yields methods that are both fast and accurate. We apply these to
experimental data and demonstrate their advantage over commonly used
non-Bayesian fitting methods.


title:
Uniformly most powerful unbiased test for conditional independence in
  Gaussian graphical model

abstract:
  Model selection for Gaussian concentration graph is based on multiple testing
of pairwise conditional independence. In practical applications partial
correlation tests are widely used. However it is not known whether partial
correlation test is uniformly most powerful for pairwise conditional
independence testing. This question is answered in the paper. Uniformly most
powerful unbiased test of Neymann structure is obtained. It turns out, that
this test can be reduced to usual partial correlation test. It implies that
partial correlation test is uniformly most powerful unbiased one.


title: Suspension of the Billiard maps in the Lazutkin's coordinate

abstract:
  In this paper we proved that under the Lazutkin's coordinate, the billiard
map can be interpolated by a time-1 flow of a Hamiltonian $H(x,p,t)$ which can
be formally expressed by \[
H(x,p,t)=p^{3/2}+p^{5/2}V(x,p^{1/2},t),\quad(x,p,t)\in\T\times[0,+\infty)\times\T,
\] where $V(\cdot,\cdot,\cdot)$ is $C^{r-5}$ smooth if the convex billiard
boundary is $C^r$ smooth. Benefit from this suspension we can construct
transitive trajectories between two adjacent caustics under a variational
framework.


title: MinMax Radon Barcodes for Medical Image Retrieval

abstract:
  Content-based medical image retrieval can support diagnostic decisions by
clinical experts. Examining similar images may provide clues to the expert to
remove uncertainties in his/her final diagnosis. Beyond conventional feature
descriptors, binary features in different ways have been recently proposed to
encode the image content. A recent proposal is "Radon barcodes" that employ
binarized Radon projections to tag/annotate medical images with content-based
binary vectors, called barcodes. In this paper, MinMax Radon barcodes are
introduced which are superior to "local thresholding" scheme suggested in the
literature. Using IRMA dataset with 14,410 x-ray images from 193 different
classes, the advantage of using MinMax Radon barcodes over \emph{thresholded}
Radon barcodes are demonstrated. The retrieval error for direct search drops by
more than 15\%. As well, SURF, as a well-established non-binary approach, and
BRISK, as a recent binary method are examined to compare their results with
MinMax Radon barcodes when retrieving images from IRMA dataset. The results
demonstrate that MinMax Radon barcodes are faster and more accurate when
applied on IRMA images.


title: Namba forcing, weak approximation, and guessing

abstract:
  We prove a variation of Easton's lemma for strongly proper forcings, and use
it to prove that, unlike the stronger principle $\textsf{IGMP}$, $\textsf{GMP}$
together with $2^\omega \le \omega_2$ is consistent with the existence of an
$\omega_1$-distributive nowhere c.c.c. forcing poset of size $\omega_1$. We
introduce the idea of a weakly guessing model, and prove that many of the
strong consequences of the principle $\textsf{GMP}$ follow from the existence
of stationarily many weakly guessing models. Using Namba forcing, we construct
a model in which there are stationarily many indestructibly weakly guessing
models which have a bounded countable subset not covered by any countable set
in the model.


title: Stacked Autoencoders for Medical Image Search

abstract:
  Medical images can be a valuable resource for reliable information to support
medical diagnosis. However, the large volume of medical images makes it
challenging to retrieve relevant information given a particular scenario. To
solve this challenge, content-based image retrieval (CBIR) attempts to
characterize images (or image regions) with invariant content information in
order to facilitate image search. This work presents a feature extraction
technique for medical images using stacked autoencoders, which encode images to
binary vectors. The technique is applied to the IRMA dataset, a collection of
14,410 x-ray images in order to demonstrate the ability of autoencoders to
retrieve similar x-rays given test queries. Using IRMA dataset as a benchmark,
it was found that stacked autoencoders gave excellent results with a retrieval
error of 376 for 1,733 test images with a compression of 74.61%.


title: Low-dose CT denoising with convolutional neural network

abstract:
  To reduce the potential radiation risk, low-dose CT has attracted much
attention. However, simply lowering the radiation dose will lead to significant
deterioration of the image quality. In this paper, we propose a noise reduction
method for low-dose CT via deep neural network without accessing original
projection data. A deep convolutional neural network is trained to transform
low-dose CT images towards normal-dose CT images, patch by patch. Visual and
quantitative evaluation demonstrates a competing performance of the proposed
method.


title: The Pointillist principle for variation operators and jump functions

abstract:
  We extend the pointillist principles of Moon and Carrillo--de Guzm\'an to
variational operators and jump functions.


title:
L-Convex Polyominoes are Recognizable in Real Time by 2D Cellular
  Automata

abstract:
  A polyomino is said to be L-convex if any two of its cells are connected by a
4-connected inner path that changes direction at most once. The 2-dimensional
language representing such polyominoes has been recently proved to be
recognizable by tiling systems by S. Brocchi, A. Frosini, R. Pinzani and S.
Rinaldi. In an attempt to compare recognition power of tiling systems and
cellular automata, we have proved that this language can be recognized by
2-dimensional cellular automata working on the von Neumann neighborhood in real
time.
  Although the construction uses a characterization of L-convex polyominoes
that is similar to the one used for tiling systems, the real time constraint
which has no equivalent in terms of tilings requires the use of techniques that
are specific to cellular automata.


title:
Accelerating Deep Convolutional Networks using low-precision and
  sparsity

abstract:
  We explore techniques to significantly improve the compute efficiency and
performance of Deep Convolution Networks without impacting their accuracy. To
improve the compute efficiency, we focus on achieving high accuracy with
extremely low-precision (2-bit) weight networks, and to accelerate the
execution time, we aggressively skip operations on zero-values. We achieve the
highest reported accuracy of 76.6% Top-1/93% Top-5 on the Imagenet object
classification challenge with low-precision network\footnote{github release of
the source code coming soon} while reducing the compute requirement by ~3x
compared to a full-precision network that achieves similar accuracy.
Furthermore, to fully exploit the benefits of our low-precision networks, we
build a deep learning accelerator core, dLAC, that can achieve up to 1
TFLOP/mm^2 equivalent for single-precision floating-point operations (~2
TFLOP/mm^2 for half-precision).


title: Traffic Predictive Control from Low-Rank Structure

abstract:
  The operation of most signalized intersections is governed by predefined
timing plans that are applied during specified times of the day. These plans
are designed to accommodate average conditions and are unable to respond to
large deviations in traffic flow. We propose a control approach that adjusts
time-of-day signaling plans based on a prediction of future traffic flow. The
prediction algorithm identifies correlated, low rank structure in historical
measurement data and predicts future traffic flow from real-time measurements
by determining which structural trends are prominent in the measurements. From
this prediction, the controller then determines the optimal time of day to
apply new timing plans. We demonstrate the potential benefits of this approach
using eight months of high resolution data collected at an intersection in
Beaufort, South Carolina.


title: Instability of Chern-Simons Theory with Fermions at Large N

abstract:
  We study the (in)stability around the dynamical gap solution of the $U(N)$
Chern-Simons gauge theory with fundamental fermions (massless or massive)
coupled in $D=3$ at large $N$. Explicit analyses on both the Auxiliary-Field
(AF) and the Cornwall-Jackiw-Tomboulis (CJT) effective potentials are given. In
both approaches we manage to analytically identify the saddle-point instability
around the gap solution. We also give a comparison with the QCD-like theories.
This study can help understanding the scale symmetry breaking picture of this
theory.


title:
Improving Comparison Shopping Agents' Competence through Selective Price
  Disclosure

abstract:
  The plethora of comparison shopping agents (CSAs) in today's markets enables
buyers to query more than a single CSA when shopping, and an inter-CSAs
competition naturally arises. We suggest a new approach, termed "selective
price disclosure", which improves the attractiveness of a CSA by removing some
of the prices in the outputted list. The underlying idea behind this approach
is to affect the buyer's beliefs regarding the chance of obtaining more
attractive prices. The paper presents two methods, which are suitable for
fully-rational buyers, for deciding which prices among those known to the CSA
should be disclosed. The effectiveness and efficiency of the methods are
evaluated using real data collected from five CSAs. The methods are also
evaluated with human subjects, showing that selective price disclosure can be
highly effective in this case as well, however, the disclosed subset of prices
should be extracted in a different (simplistic) manner.


title: On the Preciseness of Subtyping in Session Types

abstract:
  Subtyping in concurrency has been extensively studied since early 1990s as
one of the most interesting issues in type theory. The correctness of subtyping
relations has been usually provided as the soundness for type safety. The
converse direction, the completeness, has been largely ignored in spite of its
usefulness to define the largest subtyping relation ensuring type safety. This
paper formalises preciseness (i.e. both soundness and completeness) of
subtyping for mobile processes and studies it for the synchronous and the
asynchronous session calculi. We first prove that the well-known session
subtyping, the branching-selection subtyping, is sound and complete for the
synchronous calculus. Next we show that in the asynchronous calculus, this
subtyping is incomplete for type-safety: that is, there exist session types T
and S such that
  T can safely be considered as a subtype of S, but T < S is not derivable by
the subtyping. We then propose an asynchronous subtyping system which is sound
and complete for the asynchronous calculus. The method gives a general guidance
to design rigorous channel-based subtypings respecting desired safety
properties. Both the synchronous and the asynchronous calculus are first
considered with lin ear channels only, and then they are extended with session
initialisations and c ommunications of expressions (including shared channels).


title:
Electron-Hole Asymmetric Chiral Breakdown of Reentrant Quantum Hall
  States

abstract:
  Reentrant integer quantum Hall (RIQH) states are believed to be correlated
electron solid phases, though their microscopic description remains unclear. As
bias current increases, longitudinal and Hall resistivities measured for these
states exhibit multiple sharp breakdown transitions, a signature unique to RIQH
states. A comparison of RIQH breakdown characteristics at multiple voltage
probes indicates that these signatures can be ascribed to a phase boundary
between broken-down and unbroken regions, spreading chirally from source and
drain contacts as a function of bias current and passing voltage probes one by
one. The chiral sense of the spreading is not set by the chirality of the edge
state itself, instead depending on electron- or hole-like character of the RIQH
state.


title: On powers of the Euler class for flat circle bundles

abstract:
  Apparently a lost theorem of Thurston states that the cube of the Euler class
$e^3\in H^6(BDiff^{\delta}_{\omega}(S^1);\mathbb{Q})$ is zero where
$Diff^{\delta}_{\omega}(S^1)$ is the analytic orientation preserving
diffeomorphisms of the circle with the discrete topology. This is in contrast
with Morita's theorem that the powers of the Euler class are nonzero in
$H^*(BDiff^{\delta}(S^1);\mathbb{Q})$ where $Diff^{\delta}(S^1)$ is the
orientation preserving $C^{\infty}$- diffeomorphisms of the circle with the
discrete topology. The purpose of this short note is to prove that the powers
of the Euler class $e^k \in H^*(BDiff^{\delta}_{\omega}(S^1);\mathbb{Z})$ in
fact are nonzero in cohomology with integer coefficients. We also give a short
proof of Morita's theorem.


title: Comparing 1D and 2D Real Time on Cellular Automata

abstract:
  We study the influence of the dimension of cellular automata (CA) for real
time language recognition of one-dimensional languages with parallel input.
Specifically, we focus on the question of determining whether every language
that can be recognized in real time on a 2-dimensional CA working on the Moore
neighborhood can also be recognized in real time by a 1-dimensional CA working
on the standard two-way neighborhood.
  We show that 2-dimensional CA in real time can perform a linear number of
simulations of a 1-dimensional real time CA. If the two classes are equal then
the number of simulated instances can be polynomial.


title: Decoupling the short- and long-term behavior of stochastic volatility

abstract:
  We introduce a new class of continuous-time models of the stochastic
volatility of asset prices. The models can simultaneously incorporate roughness
and slowly decaying autocorrelations, including proper long memory, which are
two stylized facts often found in volatility data. Our prime model is based on
the so-called Brownian semistationary process and we derive a number of
theoretical properties of this process, relevant to volatility modeling.
Applying the models to realized volatility measures covering a vast panel of
assets, we find evidence consistent with the hypothesis that time series of
realized measures of volatility are both rough and very persistent. Lastly, we
illustrate the utility of the models in an extensive forecasting study; we find
that the models proposed in this paper outperform a wide array of benchmarks
considerably, indicating that it pays off to exploit both roughness and
persistence in volatility forecasting.


title:
5-State Rotation-Symmetric Number-Conserving Cellular Automata are not
  Strongly Universal

abstract:
  We study two-dimensional rotation-symmetric number-conserving cellular
automata working on the von Neumann neighborhood (RNCA). It is known that such
automata with 4 states or less are trivial, so we investigate the possible
rules with 5 states. We give a full characterization of these automata and show
that they cannot be strongly Turing universal. However, we give example of
constructions that allow to embed some boolean circuit elements in a 5-states
RNCA.


title:
The UK Infrared Telescope M33 monitoring project. V. The star formation
  history across the galactic disc

abstract:
  We have conducted a near-infrared monitoring campaign at the UK InfraRed
Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). On the
basis of their variability, we have identified stars in the very final stage of
their evolution, and for which the luminosity is more directly related to the
birth mass than the more numerous less-evolved giant stars that continue to
increase in luminosity. In this fifth paper of the series, we construct the
birth mass function and hence derive the star formation history across the
galactic disc of M33. The star formation rate has varied between
$\sim0.010\pm0.001$ ($\sim0.012\pm0.007$) and 0.060$\pm0.005$
(0.052$\pm0.009$)M$_\odot$ yr$^{-1}$ kpc$^{-2}$ statistically (systematically)
in the central square kiloparsec of M33, comparable with the values derived
previously with another camera. The total star formation rate in M33 within a
galactocentric radius of 14 kpc has varied between $\sim0.110\pm0.005$
($\sim0.174\pm0.060$) and $\sim0.560\pm0.028$ ($\sim0.503\pm0.100$) M$_\odot$
yr$^{-1}$ statistically (systematically). We find evidence of two epochs during
which the star formation rate was enhanced by a factor of a few -- one that
started $\sim6$ Gyr ago and lasted $\sim3$ Gyr and produced $\geq71$% of the
total mass in stars, and one $\sim250$ Myr ago that lasted $\sim200$ Myr and
formed $\leq13$% of the mass in stars. Radial star formation history profiles
suggest that the inner disc of M33 was formed in an inside-out formation
scenario. The outskirts of the disc are dominated by the old population, which
may be the result of dynamical effects over many Gyr. We find correspondence to
spiral structure for all stars, but enhanced only for stars younger than
$\sim100$ Myr; this suggests that the spiral arms are transient features and
not part of a global density wave potential.


title:
Ubiquitous diffraction resonances in positronium formation from
  fullerenes

abstract:
  Due to the dominant electron capture by positrons from the molecular wall and
the spatial dephasing across the wall-width, a powerful diffraction effect
universally underlies the positronium (Ps) formation from fullerenes. This
results into trains of resonances in the Ps formation cross section as a
function of the positron beam energy, producing uniform structures in recoil
momenta in analogy with classical single-slit diffraction fringes in the
configuration space. The prediction opens a hitherto unknown avenue of Ps
spectroscopy with nanomaterials.


title: QInfer: Statistical inference software for quantum applications

abstract:
  Characterizing quantum systems through experimental data is critical to
applications as diverse as metrology and quantum computing. Analyzing this
experimental data in a robust and reproducible manner is made challenging,
however, by the lack of readily-available software for performing principled
statistical analysis. We improve the robustness and reproducibility of
characterization by introducing an open-source library, QInfer, to address this
need. Our library makes it easy to analyze data from tomography, randomized
benchmarking, and Hamiltonian learning experiments either in post-processing,
or online as data is acquired. QInfer also provides functionality for
predicting the performance of proposed experimental protocols from simulated
runs. By delivering easy-to-use characterization tools based on principled
statistical analysis, QInfer helps address many outstanding challenges facing
quantum technology.


title: Microfluidic Pumping by Micromolar Salt Concentrations

abstract:
  An ion-exchange-resin-based microfluidic pump is introduced that utilizes
trace amounts of ions to generate fluid flows. We show experimentally that our
pump operates in almost deionized water for periods exceeding 24h and induces
fluid flows of um/s over hundreds of um. This flow displays a far-field,
power-law decay which is characteristic of two-dimensional (2D) flow when the
system is strongly confined and of three-dimensional (3D) flow when it is not.
Using theory and numerical calculations we demonstrate that our observations
are consistent with electroosmotic pumping driven by umol/L ion concentrations
in the sample cell that serve as 'fuel' to the pump. Our study thus reveals
that trace amounts of charge carriers can produce surprisingly strong fluid
flows; an insight that should benefit the design of a new class of microfluidic
pumps that operate at very low fuel concentrations.


title:
A Linear Acceleration Theorem for 2D Cellular Automata on all Complete
  Neighborhoods

abstract:
  Linear acceleration theorems are known for most computational models.
Although such results have been proved for two-dimensional cellular automata
working on specific neighborhoods, no general construction was known. We
present here a technique of linear acceleration for all two-dimensional
languages recognized by cellular automata working on complete neighborhoods.


title: Magnetic Exchange Interaction in the Spin Polarized Electron Gas

abstract:
  The exchange interaction between two magnetic moments embedded in a host
metal is fundamental to the description of the magnetic behavior of solids. In
the standard spin-degenerate electron gas, it leads to the well known
Ruderman-Kittel-Kasuya-Yoshida (RKKY) interaction, which is of the Heisenberg
form $J\vec S_1\cdot \vec S_2$, where the interaction strength $J$ oscillates
and falls off with the distance between the moments in a characteristic way.
Here, we study the more general case of the spin-polarized electron gas both in
two and three dimensions, by evaluating the interaction strength as an
integration over the product of the host Green's functions. We find that in
addition to the Heisenberg term, an additional Ising-like term appears in the
magnetic interaction, so that the net interaction for the spin-polarized gas is
of the form $J_1 \vec S_1\cdot \vec S_2 + J_2 S_{1z} S_{2z}$. The interactions
show a beating pattern as a function of distance, caused by the two different
Fermi momenta for the two spins.


title: FRETtranslator: translating FRET traces into RNA structural pathways

abstract:
  Recent genome and transcriptome sequencing projects have unveiled a plethora
of highly structured RNA molecules as central mediators of cellular function.
Single molecule Forster Resonance Energy Transfer (smFRET) is a powerful tool
for analyzing the temporal evolution of the global structure of individual RNA
molecules, in pursuit of understanding their essential
structure-dynamics-function relationships. In contrast to enzymatic and
chemical footprinting, NMR spectroscopy and X-ray crystallography, smFRET
yields temporally resolved, quantitative information about single molecules
rather than only time and ensemble averages of entire populations. This enables
unique observations of transient and rare conformations under both equilibrium
and non-equilibrium conditions.


title: Improved bounds on the diameter of lattice polytopes

abstract:
  We show that the largest possible diameter $\delta(d,k)$ of a $d$-dimensional
polytope whose vertices have integer coordinates ranging between $0$ and $k$ is
at most $kd-\lceil2d/3\rceil$ when $k\geq3$. In addition, we show that
$\delta(4,3)=8$. This substantiates the conjecture whereby $\delta(d,k)$ is at
most $\lfloor(k+1)d/2\rfloor$ and is achieved by a Minkowski sum of lattice
vectors.


title: Neutral Naturalness with Bifundamental Gluinos

abstract:
  We study constraints on one-loop neutral naturalness at the LHC by
considering gluon partners which are required to ameliorate the tuning in the
Higgs mass-squared arising at two loops. This is done with a simple orbifold
model of folded supersymmetry which not only contains color-neutral stops but
also bifundamental gluinos that are charged under the Standard Model color
group $SU(3)_C$ and a separate $SU(3)_C'$ group. The bifundamental gluinos
reduce the Higgs mass tuning at two loops and maintain naturalness provided the
gluinos are lighter than approximately 1.9 TeV for a 5 TeV cutoff scale. Limits
from the LHC already forbid bifundamental gluinos below 1.4 TeV, and other
non-colored states such as electroweakinos, $Z'$ bosons and dark sector bound
states may be probed at future colliders. The search for bifundamental gluinos
therefore provides a direct probe of one-loop neutral naturalness that can be
fully explored at the LHC.


title:
Equilibrium states on operator algebras associated to self-similar
  actions of groupoids on graphs

abstract:
  We consider self-similar actions of groupoids on the path spaces of finite
directed graphs, and construct examples of such self-similar actions using a
suitable notion of graph automaton. Self-similar groupoid actions have a
Cuntz-Pimsner algebra and a Toeplitz algebra, both of which carry natural
dynamics lifted from the gauge actions. We study the equilibrium states (the
KMS states) on the resulting dynamical systems. Above a critical inverse
temperature, the KMS states on the Toeplitz algebra are parametrised by the
traces on the full $C^*$-algebra of the groupoid, and we describe a program for
finding such traces. The critical inverse temperature is the logarithm of the
spectral radius of the incidence matrix of the graph, and at the critical
temperature the KMS states on the Toeplitz algebra factor through states of the
Cuntz-Pimsner algebra. Under a verifiable hypothesis on the self-similar
action, there is a unique KMS state on the Cuntz-Pimsner algebra. We discuss an
explicit method of computing the values of this KMS state, and illustrate with
examples.


title:
Anisotropic Heisenberg form of RKKY interaction in the one-dimensional
  spin-polarized electron gas

abstract:
  We study the indirect exchange interaction between two localized magnetic
moments, known as Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, in a
one-dimensional spin-polarized electron gas. We find explicit expressions for
each term of this interaction, study their oscillatory behaviors as a function
of the distance between two magnetic moments, $R$, and compare them with the
known results for RKKY interaction in the case of one-dimensional standard
electron gas. We show this interaction can be written in an anisotropic
Heisenberg form, $E(\vec
R)=\lambda^2\chi_{xx}(S_{1x}S_{2x}+S_{1y}S_{2y})+\lambda^2\chi_{zz}\,
S_{1z}S_{2z}$, coming from broken time-reversal symmetry of the host material.


title: Density Estimation with Distribution Element Trees

abstract:
  The estimation of probability densities based on available data is a central
task in many statistical applications. Especially in the case of large
ensembles with many samples or high-dimensional sample spaces, computationally
efficient methods are needed. We propose a new method that is based on a
decomposition of the unknown distribution in terms of so-called distribution
elements (DEs). These elements enable an adaptive and hierarchical
discretization of the sample space with small or large elements in regions with
smoothly or highly variable densities, respectively. The novel refinement
strategy that we propose is based on statistical goodness-of-fit and pair-wise
(as an approximation to mutual) independence tests that evaluate the local
approximation of the distribution in terms of DEs. The capabilities of our new
method are inspected based on several examples of different dimensionality and
successfully compared with other state-of-the-art density estimators.


title:
Effects of exchange-correlation potentials on the density functional
  description of C_60 versus C_240 photoionization

abstract:
  We study the photoionization properties of the C_60 versus C_240 molecule in
a spherical jellium frame of density functional method. Two different
approximations to the exchange-correlation (xc) functional are used: (i) The
Gunnerson-Lundqvist parametrization [Phys. Rev. B 13, 4274 (1976)] with an
explicit correction for the electron self-interaction (SIC) and (ii) a
gradient-dependent augmentation of (i) by using the van Leeuwen and Baerends
model potential [Phys. Rev. A 49, 2421 (1994)], in lieu of SIC, to implicitly
restore electrons' asymptotic properties. Ground state results from the two
schemes for both molecules show differences in the shapes of mean-field
potentials and bound-level properties. The choice of a xc scheme also
significantly alters the dipole single-photoionization cross sections obtained
by an abinitio method that incorporates linear-response dynamical correlations.
Differences in the structures and ionization responses between C_60 and C_240
uncover the effect of molecular size on the underlying physics. Analysis
indicates that the collective plasmon resonances with the gradient-based
xc-option produce results noticeably closer to the experimental data available
for C_60.


title:
Constraining the ISM properties of the Cloverleaf quasar host galaxy
  with Herschel spectroscopy

abstract:
  We present Herschel observations of far-infrared (FIR) fine-structure (FS)
lines [CII]158$\mu$m, [OI]63$\mu$m, [OIII]52$\mu$m, and [SiII]35$\mu$m in the
z=2.56 Cloverleaf quasar, and combine them with published data in an analysis
of the dense interstellar medium (ISM) in this system. Observed [CII]158$\mu$m,
[OI]63$\mu$m, and FIR continuum flux ratios are reproduced with
photodissociation region (PDR) models characterized by moderate far-ultraviolet
(FUV) radiation fields $G_0=$ 0.3-1$\times10^3$ and atomic gas densities
$n_{\rm H}=$ 3-5$\times10^3$ cm$^{-3}$, depending on contributions to
[CII]158$\mu$m from ionized gas. We assess the contribution to [CII]158$\mu$m
flux from an active galactic nucleus (AGN) narrow line region (NLR) using
ground-based measurements of the [NII]122$\mu$m transition, finding that the
NLR can contribute at most 20-30% of the observed [CII]158$\mu$m flux. The PDR
density and far-UV radiation fields inferred from the atomic lines are not
consistent with the CO emission, indicating that the molecular gas excitation
is not solely provided via UV-heating from local star-formation, but requires
an additional heating source. X-ray heating from the AGN is explored, and we
find that X-ray dominated region (XDR) models, in combination with PDR models,
can match the CO cooling without overproducing observed FS line emission. While
this XDR/PDR solution is favored given the evidence for both X-rays and
star-formation in the Cloverleaf, we also investigate alternatives for the warm
molecular gas, finding that either mechanical heating via low-velocity shocks
or an enhanced cosmic-ray ionization rate may also contribute. Finally, we
include upper limits on two other measurements attempted in the Herschel
program: [CII]158$\mu$m in FSC~10214 and [OI]63$\mu$m in APM~08279+5255.


title: Nonlinear Control of a Tethered UAV: the Taut Cable case

abstract:
  This paper focuses on the design of a stabilizing control law for an aerial
vehicle which is physically connected to a ground station by means of a tether
cable. By taking advantage of the tensile force acting along the taut cable, it
is shown that the tethered UAV is able to maintain a non-zero attitude while
hovering in a constant position. The control objective is to stabilize the
desired configuration while simultaneously ensuring that the cable remains taut
at all times. This leads to a nonlinear control problem subject to constraints.
This paper provides a two-step solution. First, the system is stabilized using
a cascade control scheme based on thrust vectoring. Then, constraint
satisfaction is guaranteed using a novel Reference Governor scheme.


title:
Pinned geometric configurations in Euclidean space and Riemannian
  manifolds

abstract:
  Let $M$ be a compact $d$-dimensional Riemannian manifold without a boundary.
Given $E \subset M$, let $\Delta_{\rho}(E)=\{\rho(x,y): x,y \in E \}$, where
$\rho$ is the Riemannian metric on $M$. Let $\Delta_{\rho}^x$ denote the pinned
distance set, namely, $\{\rho(x,y): y \in E \}$ with $x \in E$. We prove that
if the Hausdorff dimension of $E$ is greater than $\frac{d+1}{2}$, then there
exist many $x \in E$ such that the Lebesgue measure of $\Delta^x_{\rho}(E)$ is
positive. This result was previously established by Peres and Schlag in the
Euclidean setting. The main result is deduced from a variable coefficient
Euclidean formulation, which can be used to study a variety of geometric
problems. We extend our result to the setting of chains studied in \cite{BIT15}
and obtain a pinned estimate in this context. Moreover, we point out that our
scheme is quite universal in nature and this idea will be exploited in variety
of settings in the sequel.


title:
KIC 8262223: A Post-Mass Transfer Eclipsing Binary Consisting of a Delta
  Scuti Pulsator and a Helium White Dwarf Precursor

abstract:
  KIC~8262223 is an eclipsing binary with a short orbital period ($P=1.61$ d).
The {\it Kepler} light curves are of Algol-type and display deep and partial
eclipses, ellipsoidal variations, and pulsations of Delta Scuti type. We
analyzed the {\it Kepler} photometric data, complemented by phase-resolved
spectra from the R-C Spectrograph on the 4-meter Mayall telescope at Kitt Peak
National Observatory and determined the fundamental parameters of this system.
The low mass and oversized secondary ($M_2=0.20M_{\odot}$, $R_2=1.31R_{\odot}$)
is the remnant of the donor star that transferred most of its mass to the
gainer, and now the primary star. The current primary star is thus not a normal
$\delta$ Scuti star but the result of mass accretion from a lower mass
progenitor. We discuss the possible evolutionary history and demonstrate with
the MESA evolution code that the system can be understood as the result of
non-conservative binary evolution similar to that for the formation of EL CVn
type binaries. The pulsations of the primary star can be explained as radial
and non-radial pressure modes. The equilibrium models from single star
evolutionary tracks can match the observed mass and radius
($M_1=1.94M_{\odot}$, $R_1=1.67R_{\odot}$) but the predicted unstable modes
associated with these models differ somewhat from those observed. This work
presents a preliminary asteroseismic analysis of the abnormal Delta Scuti
pulsators, and we discuss the need for better theoretical understanding of such
pulsating mass gaining stars.


title: Quantitative stratification of stationary connections

abstract:
  Let $A$ be a connection of a principal bundle $P$ over a Riemannian manifold
$M$, such that its curvature $F_A\in L_{\text{loc}}^2(M)$ satisfies the
stationarity equation. It is a consequence of the stationarity that
$\theta_A(x,r)=e^{cr^2}r^{4-n}\int_{B_r(x)}|F_A|^2$ is monotonically increasing
in $r$, for some $c$ depending only on the local geometry of $M$. We are
interested in the singular set defined by $S(A)=\{x: \lim_{r\to
0}\theta_A(x,r)\neq 0\}$, and its stratification $S^k(A)=\{x: \text{no tangent
measure at $x$ is $(k+1)$-symmetric}\}$. We then introduce and study the
quantitative stratification $S^k_{\epsilon}(A)$. Roughly speaking,
$S^k_{\epsilon}(A)$ consists of points at which no tangent measure of $A$ is
$\epsilon$-close to being $(k+1)$-symmetric. In the main Theorem, we show that
$S^k_{\epsilon}$ is $k$-rectifiable and satisfies the Minkowski volume estimate
$\text{Vol}(B_r(S^k_{\epsilon})\cap B_1)\le Cr^{n-k}$. Lastly, we apply the
main theorems to the stationary Yang-Mills connections to obtain a
rectifiability theorem that extends some previously known results by G. Tian.


title: Formation of the helium EUV resonance lines

abstract:
  Context: While classical models successfully reproduce intensities of many
transition region lines, they predict helium EUV line intensities roughly an
order of magnitude lower than the observed value.
  Aims: To determine the relevant formation mechanism(s) of the helium EUV
resonance lines, capable of explaining the high intensities under quiet sun
conditions.
  Methods: We synthesise and study the emergent spectra from a 3D
radiation-magnetohydrodynamics simulation model. The effects of coronal
illumination and non-equilibrium ionisation of hydrogen and helium are included
self-consistently in the numerical simulation.
  Results: Radiative transfer calculations result in helium EUV line
intensities that are an order of magnitude larger than the intensities
calculated under the classical assumptions. The enhanced intensity of He I 584
is primarily caused by He II recombination cascades. The enhanced intensity of
He II 304 and He II 256 is caused primarily by non-equilibrium helium
ionisation.
  Conclusion: The analysis shows that the long standing problem of the high
helium EUV line intensities disappears when taking into account optically thick
radiative transfer and non-equilibrium ionisation effects.


title:
Exact extended formulation of the linear assignment problem (LAP)
  polytope for solving the traveling salesman and quadratic assignment problems

abstract:
  We present an O(n^6 ) linear programming model for the traveling salesman
(TSP) and quadratic assignment (QAP) problems. The basic model is developed
within the framework of the TSP. It does not involve the city-to-city
variables-based, traditional TSP polytope referred to in the literature as "the
TSP polytope." We do not model explicit Hamiltonian cycles of the cities.
Instead, we use a time-dependent abstraction of TSP tours and develop a direct
extended formulation of the linear assignment problem (LAP) polytope. The model
is exact in the sense that it has integral extreme points which are in
one-to-one correspondence with TSP tours. It can be solved optimally using any
linear programming (LP) solver, hence offering a new (incidental) proof of the
equality of the computational complexity classes "P" and "NP." The extensions
of the model to the time-dependent traveling salesman problem (TDTSP) as well
as the quadratic assignment problem (QAP) are straightforward. The reasons for
the non-applicability of existing negative extended formulations results for
"the TSP polytope" to the model in this paper as well as our software
implementation and the computational experimentation we conducted are briefly
discussed.


title:
Next-to-leading order QCD corrections to paired $B_c$ production in
  $e^+e^-$ annihilation

abstract:
  We present theoretical analysis of paired $B_c$ mesons production in $e^+e^-$
annihilation at different energy scales taking into account full
next-to-leading order QCD corrections. Both possible electroweak channels are
considered: production via virtual photon and via virtual $Z$-boson. We study
in detail the role of radiative QCD corrections, which were found to be
significant especially at low energies. It is shown that the contribution from
$Z$-boson is significant at high energies ($\sqrt{s} > M_Z/2$) especially in
the case of paired production of pseudo-scalar and vector ($B_c + B_c^*$)
mesons. Azimuthal asymmetry induced by a $P$-violating weak interaction with
$Z$-boson is also analyzed.


title: Security and Privacy Analysis of NSF Future Internet Architectures

abstract:
  The Internet Protocol (IP) is the lifeblood of the modern Internet. Its
simplicity and universality have fueled the unprecedented and lasting global
success of the current Internet. Nonetheless, some limitations of IP have been
emerging in recent years. Its original design envisaged supporting perhaps tens
of thousands of static hosts operating in a friendly academic-like setting,
mainly in order to facilitate email communication and remote access to scarce
computing resources. At present IP interconnects billions of static and mobile
devices (ranging from supercomputers to IoT gadgets) with a large and dynamic
set of popular applications. Starting in mid-1990s, the advent of mobility,
wirelessness and the web substantially shifted Internet usage and communication
paradigms. This accentuated long-term concerns about the current Internet
architecture and prompted interest in alternative designs.
  The U.S. National Science Foundation (NSF) has been one of the key supporters
of efforts to design a set of candidate next-generation Internet architectures.
As a prominent design requirement, NSF emphasized "security and privacy by
design" in order to avoid the long and unhappy history of incremental patching
and retrofitting that characterizes the current Internet architecture. To this
end, as a result of a competitive process, four prominent research projects
were funded by the NSF in 2010: Nebula, Named-Data Networking (NDN),
MobilityFirst (MF), and Expressive Internet Architecture (XIA). This paper
provides a comprehensive and neutral analysis of salient security and privacy
features (and issues) in these NSF-funded Future Internet Architectures. It
also compares the four candidate designs with the current IP-based architecture
and discusses similarities, differences, and possible improvements.


title:
Revisiting EPRL: All Finite-Dimensional Solutions by Naimark's
  Fundamental Theorem

abstract:
  In this paper we research all possible finite-dimensional representations and
corresponding values of the Barbero-Immirzi parameter contained in EPRL
simplicity constraints by using Naimark's fundamental theorem of the Lorentz
group representation theory. It turns out that for each non-zero pure imaginary
with rational modulus value of the Barbero-Immirzi parameter $\gamma = i
\frac{p}{q}, p, q \in Z, p, q \ne 0$, there is a solution of the simplicity
constraints, such that the corresponding Lorentz representation is finite
dimensional. The converse is also true - for each finite-dimensional Lorentz
representation solution of the simplicity constraints $(n, \rho)$, the
associated Barbero-Immirzi parameter is non-zero pure imaginary with rational
modulus, $\gamma = i \frac{p}{q}, p, q \in Z, p, q \ne 0$. We solve the
simplicity constraints with respect to the Barbero-Immirzi parameter and then
use Naimark's fundamental theorem of the Lorentz group representations to find
all finite-dimensional representations contained in the solutions.


title: Screening three-form fields

abstract:
  Screening mechanisms for a three-form field around a dense source such as the
Sun are investigated. Working with the dual vector, we can obtain a thin-shell
where field interactions are short range. The field outside the source adopts
the configuration of a dipole which is a manifestly distinct behaviour from the
one obtained with a scalar field or even a previously proposed vector field
model. We identify the region of parameter space where this model satisfies
present solar system tests.


title:
On the exact asymptotics of exit time from a cone of an isotropic
  $\alpha$-self-similar Markov process with a skew-product structure

abstract:
  In this paper we identify the asymptotic tail of the distribution of the exit
time $\tau_C$ from a cone $C$ of an isotropic $\alpha$-self-similar Markov
process $X_t$ with a skew-product structure, that is $X_t$ is a product of its
radial process and independent time changed angular component $\Theta_t$. Under
some additional regularity assumptions, the angular process $\Theta_t$ killed
on exiting from the cone $C$ has the transition density that could be expressed
in terms of a complete set of orthogonal eigenfunctions with corresponding
eigenvalues of an appropriate generator. Using this fact and some asymptotic
properties of the exponential functional of a killed L\'evy process related
with Lamperti representation of the radial process, we prove that
$$\mathbb{P}_x(\tau_C>t)\sim h(x)t^{-\kappa_1}$$ as $t\rightarrow\infty$ for
$h$ and $\kappa_1$ identified explicitly. The result extends the work of
DeBlassie (1988) and Ba\~nuelos and Smits (1997) concerning the Brownian
motion.


title:
Study of the effect of nearest neighbors on ferromagnetic to
  paramagnetic phase transition in 2D lattices by Monte Carlo algorithm

abstract:
  In this work we try to use the Monte Carlo algorithm, metropolis, to study
the behavior of 2D magnetic systems; honeycomb, hexagonal and square lattices.
In this study we use Ising Model of magnetism, with considering only nearest
neighbors in the Hamiltonian and with the Ferromagnetic correlation constant.
The code was written in Payton. In this calculation, by comparing the results
obtained for all lattices, we will show that the paramagnetic to ferromagnetic
phase transition depends on the number of neighbor and it is a direct
dependence.


title: Improving the Bounds On Murty_Simon Conjecture

abstract:
  A graph is said to be diameter-$k$-critical if its diameter is $k$ and
removal of any of its edges increases its diameter. A beautiful conjecture by
Murty and Simon, says that every diameter-2-critical graph of order $n$ has at
most $\lfloor n^2/4\rfloor$ edges and equality holds only for $K_{\lceil n/2
\rceil,\lfloor n/2 \rfloor }$. Haynes et al. proved that the conjecture is true
for $\Delta\geq 0.7n$. They also proved that for $n>2000$, if $\Delta \geq
0.6789n$ then the conjecture is true. We will improve this bound by showing
that the conjecture is true for every $n$ if $\Delta\geq\ 0.676n$.


title: Reconstruction of weakly simple polygons from their edges

abstract:
  Given $n$ line segments in the plane, do they form the edge set of a
\emph{weakly simple polygon}; that is, can the segment endpoints be perturbed
by at most $\varepsilon$, for any $\varepsilon>0$, to obtain a simple polygon?
While the analogous question for \emph{simple polygons} can easily be answered
in $O(n\log n)$ time, we show that it is NP-complete for weakly simple
polygons. We give $O(n)$-time algorithms in two special cases: when all
segments are collinear, or the segment endpoints are in general position. These
results extend to the variant in which the segments are \emph{directed}, and
the counterclockwise traversal of a polygon should follow the orientation.
  We study related problems for the case that the union of the $n$ input
segments is connected. (i) If each segment can be subdivided into several
segments, find the minimum number of subdivision points to form a weakly simple
polygon. (ii) If new line segments can be added, find the minimum total length
of new segments that creates a weakly simple polygon. We give worst-case upper
and lower bounds for both problems.


title:
An Optimal Treatment Assignment Strategy to Evaluate Demand Response
  Effect

abstract:
  Demand response is designed to motivate electricity customers to modify their
loads at critical time periods. The accurate estimation of impact of demand
response signals to customers' consumption is central to any successful
program. In practice, learning these response is nontrivial because operators
can only send a limited number of signals. In addition, customer behavior also
depends on a large number of exogenous covariates. These two features lead to a
high dimensional inference problem with limited number of observations. In this
paper, we formulate this problem by using a multivariate linear model and adopt
an experimental design approach to estimate the impact of demand response
signals. We show that randomized assignment, which is widely used to estimate
the average treatment effect, is not efficient in reducing the variance of the
estimator when a large number of covariates is present. In contrast, we present
a tractable algorithm that strategically assigns demand response signals to
customers. This algorithm achieves the optimal reduction in estimation
variance, independent of the number of covariates. The results are validated
from simulations on synthetic data.


title: When is the growth index constant?

abstract:
  The growth index $\gamma$ is an interesting tool to assess the phenomenology
of dark energy (DE) models, in particular of those beyond general relativity
(GR). We investigate the possibility for DE models to allow for a constant
$\gamma$ during the entire matter and DE dominated stages. It is shown that if
DE is described by quintessence (a scalar field minimally coupled to gravity),
this behaviour of $\gamma$ is excluded either because it would require a
transition to a phantom behaviour at some finite moment of time, or, in the
case of tracking DE at the matter dominated stage, because the relative matter
density $\Omega_m$ appears to be too small. An infinite number of solutions,
with $\Omega_m$ and $\gamma$ both constant, are found with $w_{DE}=0$
corresponding to Einstein-de Sitter universes. For all modified gravity DE
models satisfying $G_{\rm eff}\ge G$, among them the $f(R)$ DE models suggested
in the literature, the condition to have a constant $w_{DE}$ is strongly
violated at the present epoch. In contrast, DE tracking dust-like matter deep
in the matter era, but with $\Omega_m <1$, requires $G_{\rm eff} > G$ and an
example is given using scalar-tensor gravity for a range of admissible values
of $\gamma$. For constant $w_{DE}$ inside GR, departure from a quasi-constant
value is limited until today. Even a large variation of $w_{DE}$ may not result
in a clear signature in the change of $\gamma$. The change however is
substantial in the future and the asymptotic value of $\gamma$ is found while
its slope with respect to $\Omega_m$ (and with respect to $z$) diverges and
tends to $-\infty$.


title: F(750), We Miss You, as Bound State of 6 Top and 6 Anti top

abstract:
  We collect and estimate support for our long speculated "multiple point
principle" saying that there should be several vacua all having (compared to
the scales of high energy physics) very low energy densities. In pure Standard
Model we suggest there being three by "multiple point principle" low energy
density vacua, "present", "condensate" and "high field" vacuum. We fit the mass
of the in our picture since long speculated bound state of six top and six anti
top quarks in three quite {\em independent ways} and get remarkably within our
crude accuracy the {\em same} mass in all three fits! The new point of the
present article is to estimate the bound state mass in what we could call a bag
model estimation. The two other fits, which we review, obtain the mass of the
bound state by fitting to the multiple point principle prediction of degenerate
vacua.
  Our remarkable agreement of our three mass-fits can be interpreted to mean,
that we have calculated at the end the energy densities of the two extra
speculated vacua and found that they are indeed very small!. Unfortunately the
recently much discussed statistical fluctuation peak F(750) has now been
revealed to be just a fluctuation, very accidentally matches our fitted mass of
the bound state remarkably well with the mass of this fluctuation 750 GeV.


title:
Intrinsic magnetic properties of {$R$(Fe$_{1-x}$Co$_{x}$)$_{11}$Ti$Z$}
  ($R$ = Y and Ce; $Z$ = H, C, and N)

abstract:
  To guide improved properties coincident with reduction of critical materials
in permanent magnets, we investigate via density functional theory (DFT) the
intrinsic magnetic properties of a promising system,
$R$(Fe$_{1-x}$Co$_{x}$)$_{11}$Ti$Z$ with $R$=Y, Ce and interstitial doping
($Z$=H, C, N). The magnetization $M$, Curie temperature $T_\text{C}$, and
magnetocrystalline anisotropy energy $K$ calculated in local density
approximation to DFT agree well with measurements. Site-resolved contributions
to $K$ reveal that all three Fe sublattices promote uniaxial anisotropy in
YFe$_{11}$Ti, while competing anisotropy contributions exist in YCo$_{11}$Ti.
As observed in experiments on $R$(Fe$_{1-x}$Co$_{x}$)$_{11}$Ti, we find a
complex nonmonotonic dependence of $K$ on Co content, and show that anisotropy
variations are a collective effect of MAE contributions from all sites and
cannot be solely explained by preferential site occupancy. With interstitial
doping, calculated $T_\text{C}$ enhancements are in the sequence of N$>$C$>$H,
with volume and chemical effects contributing to the enhancement. The uniaxial
anisotropy of $R$(Fe$_{1-x}$Co$_{x}$)$_{11}$Ti$Z$ generally decreases with C
and N; although, for $R$=Ce, C doping is found to greatly enhance it for a
small range of 0.7$<$$x$$<$0.9.