title: Weakly linearly Lindel\"of monotonically normal spaces are Lindel\"of

abstract:
  We call a space $X$ {\it weakly linearly Lindel\"of} if for any family
$\mathcal{U}$ of non-empty open subsets of $X$ of regular uncountable
cardinality $\kappa$, there exists a point $x\in X$ such that every
neighborhood of $x$ meets $\kappa$-many elements of $\mathcal{U}$. We also
introduce the concept of {\it almost discretely Lindel\"of} spaces as the ones
in which every discrete subspace can be covered by a Lindel\"of subspace. We
prove that, in addition to linearly Lindel\"of spaces, both weakly Lindel\"of
spaces and almost discretely Lindel\"of spaces are weakly linearly Lindel\"of.
  The main result of the paper is formulated in the title. It implies, among
other things, that every weakly Lindel\"of monotonically normal space is
Lindel\"of; this result seems to be new even for linearly ordered topological
spaces.
  We show that, under the hypothesis $2^\omega < \omega_\omega$, if the
co-diagonal $\Delta^c_X=(X\times X)\setminus \Delta_X$ of a space $X$ is
discretely Lindel\"of, then $X$ is Lindel\"of and has a weaker second countable
topology; here $\Delta_X=\{(x,x): x\in X\}$ is the diagonal of the space $X$.
Moreover, the discrete Lindel\"ofness of $\Delta^c_X$ together with the
Lindel\"of $\Sigma$-property of $X$ imply that $X$ has a countable network.


title: Dust ball physics and the Schwarzschild metric

abstract:
  A physics-first derivation of the Schwarzschild metric is given. Gravitation
is described in terms of the effects of tidal forces (or of spacetime
curvature) on the volume of a small ball of test particles (a dust ball),
freely falling after all particles were at rest with respect to each other
initially. The possibility to express Einstein's equation this way and some of
its ramifications have been enjoyably discussed by Baez and Bunn [Am. J. Phys.
73, 644 (2005)]. Since the formulation avoids the use of tensors, neither
advanced tensor calculus nor sophisticated differential geometry are needed in
the calculation. The derivation is not lengthy and it has visual appeal, so it
may be useful in teaching.


title:
Suzaku and Chandra Observations of CIZA J1700.8$-$3144, a Cluster of
  Galaxies in the Zone of Avoidance

abstract:
  We present the Chandra and Suzaku observations of 1RXS J170047.8$-$314442,
located towards the Galactic bulge, to reveal a wide-band ($0.3$-$10$ keV)
X-ray morphology and spectrum of this source. With the Chandra observation, no
point source was found at the position of 1RXS J170047.8$-$314442.
Alternatively, we revealed the presence of diffuse X-ray emission by the
wide-band X-ray image obtained from the Suzaku XIS. Although the X-ray emission
had a nearly circular shape with a spatial extent of $\sim 3.5'$, the surface
brightness profile was not axisymmetric; a bright spot-like emission was found
at $\sim 1'$ away in the north-western direction from the center. The radial
profile of the surface brightness, except for this spot-like emission, was
reproduced with a single $\beta$-model; $\beta$ and the core radius were found
to be $1.02$ and $1.51'$, respectively. The X-ray spectrum of the diffuse
emission showed an emission line at $\sim 6$ keV, indicating an origin of a
thermal plasma. The spectrum was well explained with an absorbed optically-thin
thermal plasma model with a temperature of $6.2$ keV and a redshift parameter
of $z = 0.14 \pm 0.01$. Hence, the X-ray emission was considered to arise from
the hot gas associated with a cluster of galaxies. Our spectroscopic result
confirmed the optical identification of 1RXS J170047.8$-$314442 by Kocevski et
al. (2007): CIZA J1700.8$-$3144, a member of the cluster catalogue in the Zone
of Avoidance. The estimated bolometric X-ray luminosity of $5.9 \times 10^{44}$
erg s$^{-1}$ was among the lowest with this temperature, suggesting that this
cluster is far from relaxed.


title:
A numerical implementation of the unified Fokas transform for evolution
  problems on a finite interval

abstract:
  We present the numerical solution of two-point boundary value problems for a
third order linear PDE, representing a linear evolution in one space dimension.
The difficulty of this problem is in the numerical imposition of the boundary
conditions, and to our knowledge, no such computations exist. Instead of
computing the evolution numerically, we evaluate the solution representation
formula obtained by the unified transform of Fokas. This representation
involves complex line integrals, but in order to evaluate these integrals
numerically, it is necessary to deform the integration contours using
appropriate deformation mappings. We formulate a strategy to implement
effectively this deformation, which allows us to obtain accurate numerical
results.


title: Multihole edge states in Su-Schrieffer-Heeger chains with interactions

abstract:
  We address the effect of nearest-neighbor (NN) interactions on the
topological properties of the Su-Schrieffer-Heeger (SSH) chain, with
alternating hopping amplitudes t1 and t2. Both numerically and analytically, we
show that the presence of interactions induces phase transitions between
topologically different regimes. In the particular case of one-hole excitations
in a half-filled SSH chain, the V=t2 vs. t1=t2 phase diagram has topological
phases at diagonal regions of the phase plane. The interaction acts in this
case as a passivation potential. For general filling of the SSH chain,
different eigensubspaces of the SSH Hamiltonian may be classified as
topologically trivial and non-trivial. The two-hole case is studied in detail
in the large interaction limit, and we show that a mapping can be constructed
of the two-hole SSH eigensubspaces into one-particle states of a
non-interacting one-dimensional (1D) tight-binding model, with interfaces
between regions with different hopping constants and local potentials. The
presence of topological edge states in the equivalent chain can be readily
identifed, as well as their correspondence to the original two-hole states.
Furthermore, we found that the presence of the NN interaction generates a state
where two holes occupy two consecutive edge states. Such many-body states
should also occur for arbitrary filling leading to the possibility of a
macroscopic hole gathering at the surface (at consecutive edge states).


title:
Single-walled TiO2 Nanotubes: Enhanced Carrier-transport Properties by
  TiCl4-Treatment

abstract:
  In the present work we report significant enhancement of the
photoelectrochemical properties of self-organized TiO2 nanotubes by a combined
de-coring of classic nanotubes followed by an appropiate TiCl4-treatment. We
show that, except for the expected particle decoration, a key effect of the
TiCl4 treatment is that the electron transport characteristics in TiO2
nanotubes can be drastically improved, e.g. we observe an enhancement of up to
70 % in electron transport times.


title:
Nonlinear Dynamics of a two-level system of a single spin driven beyond
  the rotating-wave approximation

abstract:
  Quantum systems driven by strong oscillating fields are the source of many
interesting physical phenomena. In this work, we experimentally study the
dynamics of a two-level system of a single spin driven in the strong-driving
regime where the rotating-wave approximation is not valid. This two-level
system is a subsystem of a single Nitrogen-Vacancy center coupled to a
first-shell $^{13}$C nuclear spin in diamond at a level anti-crossing point
that occurs in the $m_{s}=\pm1$ manifold when the energy level splitting
between the $m_{s}$ = $+1$ and $-1$ spin states due to the static magnetic
field is $\approx$ 127 MHz, which is roughly equal to the spectral splitting
due to the $^{13}$C hyperfine interaction. The transition frequency of this
electron spin two-level system in a static magnetic field of 28.9 G is 1.7 MHz
and it can be driven only by the $z$-component of the RF field. Electron spin
Rabi frequencies in this system can reach tens of MHz even for moderate RF
powers. The simple sinusoidal Rabi oscillations that occur when the amplitude
of the driving field is much smaller than the transition frequency become
complex when the driving field strength is comparable or greater than the
energy level splitting. We observe that the system oscillates faster than the
amplitude of the driving field and the response of the system shows multiple
frequencies.


title: On Communication Cost vs. Load Balancing in Content Delivery Networks

abstract:
  It is well known that load balancing and low delivery communication cost are
two critical issues in mapping requests to servers in Content Delivery Networks
(CDNs). However, the trade-off between these two performance metrics has not
been yet quantitatively investigated in designing efficient request mapping
schemes. In this work, we formalize this trade-off through a stochastic
optimization problem. While the solutions to the problem in the extreme cases
of minimum communication cost and optimum load balancing can be derived in
closed form, finding the general solution is hard to derive. Thus we propose
three heuristic mapping schemes and compare the trade-off performance of them
through extensive simulations.
  Our simulation results show that at the expense of high query cost, we can
achieve a good trade-off curve. Moreover, by benefiting from the power of
multiple choices phenomenon, we can achieve almost the same performance with
much less query cost. Finally, we can handle requests with different delay
requirements at the cost of degrading network performance.


title:
The proximal augmented Lagrangian method for nonsmooth composite
  optimization

abstract:
  We study a class of optimization problems in which the objective function is
given by the sum of a differentiable but possibly nonconvex component and a
nondifferentiable convex regularization term. We introduce an auxiliary
variable to separate the objective function components and utilize the Moreau
envelope of the regularization term to derive the proximal augmented Lagrangian
$-$ a continuously differentiable function obtained by constraining the
augmented Lagrangian to the manifold that corresponds to the explicit
minimization over the variable in the nonsmooth term. The continuous
differentiability of this function with respect to both primal and dual
variables allows us to leverage the method of multipliers (MM) to compute
optimal primal-dual pairs by solving a sequence of differentiable problems. The
MM algorithm is applicable to a broader class of problems than proximal
gradient methods and it has stronger convergence guarantees and a more refined
step-size update rules than the alternating direction method of multipliers.
These features make it an attractive option for solving structured optimal
control problems. We also develop an algorithm based on the primal-descent
dual-ascent gradient method and prove global (exponential) asymptotic stability
when the differentiable component of the objective function is (strongly)
convex and the regularization term is convex. Finally, we identify classes of
problems for which the primal-dual gradient flow dynamics are convenient for
distributed implementation and compare/contrast our framework to the existing
approaches.


title: The Pale Orange Dot: The Spectrum and Habitability of Hazy Archean Earth

abstract:
  Recognizing whether a planet can support life is a primary goal of future
exoplanet spectral characterization missions, but past research on habitability
assessment has largely ignored the vastly different conditions that have
existed in our planet's long habitable history. This study presents simulations
of a habitable yet dramatically different phase of Earth's history, when the
atmosphere contained a Titan-like organic-rich haze. Prior work has claimed a
haze-rich Archean Earth (3.8-2.5 billion years ago) would be frozen due to the
haze's cooling effects. However, no previous studies have self-consistently
taken into account climate, photochemistry, and fractal hazes. Here, we
demonstrate using coupled climate-photochemical-microphysical simulations that
hazes can cool the planet's surface by about 20 K, but habitable conditions
with liquid surface water could be maintained with a relatively thick haze
layer (tau ~ 5 at 200 nm) even with the fainter young sun. We find that
optically thicker hazes are self-limiting due to their self-shielding
properties, preventing catastrophic cooling of the planet. Hazes may even
enhance planetary habitability through UV shielding, reducing surface UV flux
by about 97% compared to a haze-free planet, and potentially allowing survival
of land-based organisms 2.6.2.7 billion years ago. The broad UV absorption
signature produced by this haze may be visible across interstellar distances,
allowing characterization of similar hazy exoplanets. The haze in Archean
Earth's atmosphere was strongly dependent on biologically-produced methane, and
we propose hydrocarbon haze may be a novel type of spectral biosignature on
planets with substantial levels of CO2. Hazy Archean Earth is the most alien
world for which we have geochemical constraints on environmental conditions,
providing a useful analog for similar habitable, anoxic exoplanets.


title:
Dominant dark matter and a counter rotating disc: MUSE view of the low
  luminosity S0 galaxy NGC 5102

abstract:
  The kinematics and stellar populations of the low-mass nearby S0 galaxy NGC
5102 are studied from integral field spectra taken with the Multi-Unit
Spectroscopic Explorer (MUSE). The kinematic maps reveal for the first time
that NGC 5102 has the characteristic 2 sigma peaks indicative of galaxies with
counter-rotating discs. This interpretation is quantitatively confirmed by
fitting two kinematic components to the observed spectra. Through stellar
population analysis we confirm the known young stellar population in the centre
and find steep age and metallicity gradients. We construct axisymmetric Jeans
anisotropic models of the stellar dynamics to investigate the initial mass
function (IMF) and the dark matter halo of the galaxy. The models show that
this galaxy is quite different from all galaxies previously studied with a
similar approach: even within the half-light radius, it cannot be approximated
with the self-consistent mass-follows-light assumption. Including an NFW dark
matter halo, we need a heavy IMF and a dark matter fraction of 0.37+-0.04
within a sphere of one effective radius to describe the stellar kinematics. The
more general model with a free slope of the dark matter halo shows that slope
and IMF are degenerate, but indicates that a light weight IMF (Chabrier-like)
and a higher dark matter fraction, with a steeper (contracted) halo, fit the
data better. Regardless of the assumptions about the halo profile, we measure
the slope of the total mass density to be -1.75+-0.04. This is shallower than
the slope of -2 of an isothermal halo and shallower than published slopes for
more massive early type galaxies.


title:
Aligned metal oxide nanotube arrays: key-aspects of anodic TiO2 nanotube
  formation and properties

abstract:
  Over the past ten years, self-aligned TiO2 nanotubes have attracted
tremendous scientific and technological interest due to their anticipated
impact on energy conversion, environment remediation and biocompatibility. In
the present manuscript, we review fundamental principles that govern the
self-organized initiation of anodic TiO2 nanotubes. We start with the
fundamental question: Why is self-organization taking place? We illustrate the
inherent key mechanistic aspects that lead to tube growth in various different
morphologies, such as rippled-walled tubes, smooth tubes, stacks and
bamboo-type tubes, and importantly the formation of double-walled TiO2
nanotubes versus single-walled tubes, and the drastic difference in their
physical and chemical properties. We show how both double- and single-walled
tube layers can be detached from the metallic substrate and exploited for the
preparation of robust self-standing membranes. Finally, we show how by
selecting the right growth approach to TiO2 nanotubes specific functional
features can be significantly improved, e.g., an enhanced electron mobility,
intrinsic doping, or crystallization into pure anatase at extremely high
temperatures can be achieved. This in turn can be exploited in constructing
high performance devices based on anodic TiO2 in a wide range of applications.


title:
CUORE-0 background analysis and evaluation of $^{130}$Te
  $2\nu\beta\beta$ decay half-life

abstract:
  CUORE is a bolometric experiment that will search for the Neutrinoless Double
Beta decay of $^{130}$Te. CUORE-0 is a single CUORE-like tower that was run
between 2013 and 2015 to test the performance of the CUORE experiment. In this
proceeding we present the results of the model developed to disentangle and
quantify the background sources that combine to form the CUORE-0 energy
spectrum. We use detailed Geant4-based simulations and a Bayesian fitting
algorithm to reconstruct the experimental data and evaluate the activities of
the background sources. A direct outcome of this analysis is the measurement of
the $^{130}$Te $2\nu\beta\beta$ decay half-life, of which we provide a
preliminary evaluation.


title:
Ultrafast Fault-Tolerant Long-Distance Quantum Communication with Static
  Linear Optics

abstract:
  We present an in-depth analysis regarding the error resistance and
optimization of our all-optical Bell measurement and ultrafast long-distance
quantum communication scheme proposed in [arXiv:1503.06777]. In order to
promote our previous proposal from loss- to fault-tolerance, we introduce a
general and compact formalism that can also be applied to other related schemes
(including non-all-optical ones such as [PRL 112, 250501]). With the help of
this new representation we show that our communication protocol does not only
counteract the inevitable photon loss during channel transmission, but is also
able to resist common experimental errors such as Pauli-type errors (bit- and
phase-flips) and detector inefficiencies (losses and dark counts). Furthermore,
we demonstrate that on the physical level of photonic qubits the choice of the
standard linear optical Bell measurement with its limited efficiency is optimal
for our setting in the sense that, apart from their potential use in state
preparation, more advanced Bell measurements yield only a small decrease in
resource consumption. We devise two state generation schemes that provide the
required ancillary encoded Bell states (quasi-)on-demand at every station. The
schemes are either based on nonlinear optics or on linear optics with
multiplexing and exhibit resource costs that scale linearly or less than
quadratic with the number of photons per encoded qubit, respectively. Finally,
we show that it is possible to operate our communication scheme with on-off
detectors instead of employing photon-number-resolving detectors.


title:
Impact of giant resonant dispersion on the response of intracavity phase
  interferometry and laser gyros

abstract:
  Intracavity Phase Interferometry is a phase sensing technique using
mode-locked lasers in which two intracavity pulses circulate. The beat
frequency between the two output frequency combs is proportional to a phase
shift to be measured. A laser gyro is a particular implementation of this
device. The demonstrated sensitivity of $10^{-8}$ could be manipulated by
applying a giant dispersion to each tooth of the comb. Such coupling is
achieved with an intracavity etalon, resulting a large change in phase response
of a ring laser. This change is shown to be unrelated to the average pulse
velocity within the laser cavity.


title:
The optimal multilevel Monte-Carlo approximation of the stochastic
  drift-diffusion-Poisson system

abstract:
  Existence and local-uniqueness theorems for weak solutions of a system
consisting of the drift-diffusion-Poisson equations and the Poisson-Boltzmann
equation, all with stochastic coefficients, are presented. For the numerical
approximation of the expected value of the solution of the system, we develop a
multi-level Monte-Carlo (MLMC) finite-element method (FEM) and we analyze its
rate of convergence and its computational complexity. This allows to find the
optimal choice of discretization parameters. Finally, numerical results show
the efficiency of the method. Applications are, among others, noise and
fluctuations in nanoscale transistors, in field-effect bio- and gas sensors,
and in nanopores.


title:
Three dimensional reconstruction of therapeutic carbon ion beams in
  phantoms using single secondary ion tracks

abstract:
  Carbon ion beam radiotherapy enables a very localised dose deposition.
However, already small changes in the patient geometry or positioning errors
can significantly distort the dose distribution. A live monitoring system of
the beam delivery within the patient is therefore highly desirable and could
improve patient treatment. We present a novel three-dimensional imaging method
of the beam in the irradiated object, exploiting the measured tracks of single
secondary ions emerging under irradiation. The secondary particle tracks are
detected with a TimePix stack, a set of parallel pixelated semiconductor
detectors. We developed a three-dimensional reconstruction algorithm based on
maximum likelihood expectation maximisation. We demonstrate the applicability
of the new method in an irradiation of a cylindrical PMMA phantom of human head
size with a carbon ion pencil beam of 226MeV/u. The beam image in the phantom
is reconstructed from a set of 9 discrete detector positions between -80 and 50
degrees from the beam axis. Furthermore, we demonstrate the potential to
visualise inhomogeneities by irradiating a PMMA phantom with an air gap as well
as bone and adipose tissue surrogate inserts. We successfully reconstructed a
3D image of the treatment beam in the phantom from single secondary ion tracks.
The beam image corresponds well to the distribution expected from the beam
direction and energy. In addition, cylindrical inhomogeneities with a diameter
of 2.85cm and density differences down to 0.3g/cm$^3$ to the surrounding
material are clearly visualised. This novel 3D method to image a therapeutic
carbon ion beam in the irradiated object does not interfere with the treatment
and requires knowledge only of single secondary ion tracks. Even with detectors
with only a small angular coverage, the 3D reconstruction of the fragmentation
points presented in this work was found to be feasible.


title:
On the computational complexity of read once resolution decidability in
  2CNF formulas

abstract:
  In this paper, we analyze 2CNF formulas from the perspectives of Read-Once
resolution (ROR) refutation schemes. We focus on two types of ROR refutations,
viz., variable-once refutation and clause-once refutation. In the former, each
variable may be used at most once in the derivation of a refutation, while in
the latter, each clause may be used at most once. We show that the problem of
checking whether a given 2CNF formula has an ROR refutation under both schemes
is NP-complete. This is surprising in light of the fact that there exist
polynomial refutation schemes (tree-resolution and DAG-resolution) for 2CNF
formulas. On the positive side, we show that 2CNF formulas have copy-complexity
2, which means that any unsatisfiable 2CNF formula has a refutation in which
any clause needs to be used at most twice.


title:
Quantum dynamics of an optomechanical system in the presence of photonic
  Bose-Einstein condensate

abstract:
  In this paper, we study theoretically the optomechanical interaction of an
almost pure condensate of photons with an oscillating mechanical membrane in a
micro-cavity. We show that in the Bogoliubov approximation, due to the large
number of photons in the condensate phase, there is a linear strong effective
coupling between the Bogoliubov mode of the photonic Bose-Einstein condensate
(BEC) and the mechanical motion of the membrane which depends on the nonlinear
photon-photon scattering potential. This coupling leads to the cooling of the
mechanical motion, the normal mode splitting (NMS), the squeezing of the output
field and the entanglement between the excited mode of the cavity and the
mechanical mode. We show that, in one hand, the nonlinearity of the photon gas
increases the degree of the squeezing of the output field of the micro-cavity
and the efficiency of the cooling process at high temperatures. In the other
hand, it reduces NMS in the displacement spectrum of the oscillating membrane
and the degree of the optomechanical entanglement. In addition, the temperature
of the photonic BEC can be used to control the above-mentioned phenomena.


title:
Ambitwistor Strings: Worldsheet Approaches to perturbative Quantum Field
  Theories

abstract:
  Tree-level scattering amplitudes in massless theories not only exhibit a
simplicity entirely unexpected from Feynman diagrams, but also an underlying
structure remarkably reminiscent of worldsheet theory correlators. These
features can be explained by ambitwistor strings - two-dimensional chiral
conformal field theories in an auxiliary target space, the complexified phase
space of null geodesics. The aim of this thesis is to explore the ambitwistor
string approach to understand these structures in amplitudes, and thereby
provide a new angle on quantum field theories. The first part of the thesis
provides a user-friendly introduction to ambitwistor strings, as well as a
condensed overview over the literature and some novel results. Emphasising the
study of tree-level amplitudes, we then explore the wide-ranging impact of
ambitwistor strings for an extensive family of massless theories, and discuss
the duality between asymptotic symmetries and the low energy behaviour of a
theory from the point of view of the worldsheet CFT. The second part of this
thesis focusses on proving a conjectured ambitwistor string formula for loop
amplitudes, and extending the formalism to more general theories. Remarkably,
residue theorems reduce the computationally challenging ambitwistor
higher-genus expressions to simple formulae on nodal Riemann spheres. This idea
is developed into a widely applicable framework for loop integrands, that is
shown to be applicable to both supersymmetric and non-supersymmetric theories.
In the case of supergravity, this provides strong evidence for the validity of
the ambitwistor string at loop level, and explicit proofs are given for
non-supersymmetric theories. This leads to a proposal for an all-loop integrand
for gravity and Yang-Mills.


title:
Quasinormal Modes of Charged Black Holes Localized in the
  Randall-Sundrum Brane World

abstract:
  We study the quasinormal modes of the massless scalar field of charged black
holes embedded in the Randal-Sundrum brane world using the third order WKB
approximation. We consider the effects of the electromagnetic and tidal charges
on quasinormal frequencies spectrum for charged black hole black holes as well
as the effect of the thickness of the bulk.


title:
Ba$_{3}$M$_{x}$Ti$_{3-x}$O$_{9}$(M = Ir, Rh): A family of
  5\textit{\textcolor{black}{d}}/4\textit{\textcolor{black}{d}}-based, diluted
  quantum spin liquids

abstract:
  We report the structural and magnetic properties of the
4}\textit{\textcolor{black}{d }}\textcolor{black}{(M = Rh) based and
5}\textit{\textcolor{black}{d }}\textcolor{black}{(M = Ir) based systems
Ba$_{3}$M$_{x}$Ti$_{3-x}$O$_{9}$ (nominally $x$ = 0.5, 1). The studied
compositions were found to crystallize in a hexagonal structure with the
centrosymmetric space group }$P6_{3}/mmc$.\textcolor{black}{{} The structures
comprise of A$_{2}$O$_{9}$ polyhedra (with the A site (possibly) statistically
occupied by M and Ti) in which pairs of transition metal ions are stacked along
the crystallographic }\textit{\textcolor{black}{c}}\textcolor{black}{-axis.
These pairs form triangular bilayers in the $ab$-plane. The magnetic Rh and Ir
ions occupy these bilayers, diluted by Ti ions even for $x$ = 1. These bilayers
are separated by a triangular layer which is dominantly occupied by Ti ions.
From magnetization measurements we infer strong antiferromagnetic couplings for
all of the materials but the absence of any spin-freezing or spin-ordering down
to 2~K. Further, specific heat measurements down to 0.35~K show no sign of a
phase transition for any of the compounds. Based on these thermodynamic
measurements we propose the emergence of a quantum spin liquid ground state for
Ba$_{3}$Rh$_{0.5}$Ti$_{2.5}$O$_{9}$, and Ba$_{3}$Ir$_{0.5}$Ti$_{2.5}$O$_{9}$,
in addition to the already reported Ba$_{3}$IrTi$_{2}$O$_{9}$. }


title: Heavy-Quark QCD Exotica

abstract:
  This review presents an overview of the remarkable progress in the field of
heavy-quark exotic hadrons over the past 15 years. It seeks to be pedagogical
rather than exhaustive, summarizing both the progress and specific results of
experimental discoveries, and the variety of theoretical approaches designed to
explain these new states.


title: Onset of negative dispersion in one-component-plasma revisited

abstract:
  A simple approach to describe the long-wavelength dispersion of the
longitudinal (plasmon) mode of the classical one-component-plasma (OCP), with
the main objective to correctly capture the onset of negative dispersion, is
proposed. The approach is applicable to both three-dimensional and
two-dimensional OCP. The predicted onset of negative dispersion compares well
with the available results from numerical simulations and more sophisticated
theoretical models.


title:
Symmetric Private Information Retrieval For MDS Coded Distributed
  Storage

abstract:
  A user wants to retrieve a file from a database without revealing the
identity of the file retrieved at the database, which is known as the problem
of private information retrieval (PIR). If it is further required that the user
obtains no information about the database other than the desired file, the
concept of symmetric private information retrieval (SPIR) is introduced to
guarantee privacy for both parties. In this paper, the problem of SPIR is
studied for a database stored among $N$ nodes in a distributed way, by using an
$(N,M)$-MDS storage code. The information-theoretic capacity of SPIR, defined
as the maximum number of symbols of the desired file retrieved per downloaded
symbol, for the coded database is derived. It is shown that the SPIR capacity
for coded database is $1-\frac{M}{N}$, when the amount of the shared common
randomness of distributed nodes (unavailable at the user) is at least
$\frac{M}{N-M}$ times the file size. Otherwise, the SPIR capacity for the coded
database equals zero.


title:
Numerical Inversion of SRNF Maps for Elastic Shape Analysis of
  Genus-Zero Surfaces

abstract:
  Recent developments in elastic shape analysis (ESA) are motivated by the fact
that it provides comprehensive frameworks for simultaneous registration,
deformation, and comparison of shapes. These methods achieve computational
efficiency using certain square-root representations that transform invariant
elastic metrics into Euclidean metrics, allowing for applications of standard
algorithms and statistical tools. For analyzing shapes of embeddings of
$\mathbb{S}^2$ in $\mathbb{R}^3$, Jermyn et al. introduced square-root normal
fields (SRNFs) that transformed an elastic metric, with desirable invariant
properties, into the $\mathbb{L}^2$ metric. These SRNFs are essentially surface
normals scaled by square-roots of infinitesimal area elements. A critical need
in shape analysis is to invert solutions (deformations, averages, modes of
variations, etc) computed in the SRNF space, back to the original surface space
for visualizations and inferences. Due to the lack of theory for understanding
SRNFs maps and their inverses, we take a numerical approach and derive an
efficient multiresolution algorithm, based on solving an optimization problem
in the surface space, that estimates surfaces corresponding to given SRNFs.
This solution is found effective, even for complex shapes, e.g. human bodies
and animals, that undergo significant deformations including bending and
stretching. Specifically, we use this inversion for computing elastic shape
deformations, transferring deformations, summarizing shapes, and for finding
modes of variability in a given collection, while simultaneously registering
the surfaces. We demonstrate the proposed algorithms using a statistical
analysis of human body shapes, classification of generic surfaces and analysis
of brain structures.


title: Polarization of photons emitted by decaying dark matter

abstract:
  Radiatively decaying dark matter may be searched through investigating the
photon spectrum of galaxies and galaxy clusters. We explore whether the
properties of dark matter can be constrained through the study of a
polarization state of emitted photons. Starting from the basic principles of
quantum mechanics we show that the models of symmetric dark matter are
indiscernible by the photon polarization. However, we find that the asymmetric
dark matter consisted of Dirac fermions is a source of circularly polarized
photons, calling for the experimental determination of the photon state.


title:
A Comprehensive Comparative Study of Word and Sentence Similarity
  Measures

abstract:
  Sentence similarity is considered the basis of many natural language tasks
such as information retrieval, question answering and text summarization. The
semantic meaning between compared text fragments is based on the words semantic
features and their relationships. This article reviews a set of word and
sentence similarity measures and compares them on benchmark datasets. On the
studied datasets, results showed that hybrid semantic measures perform better
than both knowledge and corpus based measures.


title: Khovanov width and dealternation number of positive braid links

abstract:
  We give asymptotically sharp upper bounds for the Khovanov width and the
dealternation number of positive braid links, in terms of their crossing
number. The same braid-theoretic technique, combined with Ozsv\'ath, Stipsicz,
and Szab\'o's Upsilon invariant, allows us to determine the exact cobordism
distance between torus knots with braid index two and six.


title: The Automorphism Groups for a family of Generalized Weyl Algebras

abstract:
  In this paper, we study a family of generalized Weyl algebras $\{\A\}$ and
their polynomial extensions. We will show that the algebra $\A$ has a simple
localization $\A_{\mathbb{S}}$ when none of $p$ and $q$ is a root of unity. As
an application, we determine all the height-one prime ideals and the center for
$\A$, and prove that $\A$ is cancellative. Then we will determine the
automorphism group and solve the isomorphism problem for the generalized Weyl
algebras $\A$ and their polynomial extensions in the case where none of $p$ and
$q$ is a root of unity. We will establish a quantum analogue of the Dixmier
conjecture and compute the automorphism group for the simple localization
$(\mathcal{A}_{p}(1, 1, \K_{q}[s, t]))_{\mathbb{S}}$. Moreover, we will
completely determine the automorphism group for the algebra $\mathcal{A}_{p}(1,
1, \K_{q}[s, t])$ and its polynomial extension when $p\neq 1$ and $q\neq 1$.


title:
Bridging Asymptotic Independence and Dependence in Spatial Extremes
  Using Gaussian Scale Mixtures

abstract:
  Gaussian scale mixtures are constructed as Gaussian processes with a random
variance. They have non-Gaussian marginals and can exhibit asymptotic
dependence unlike Gaussian processes, which are asymptotically independent
except in the case of perfect dependence. In this paper, we study in detail the
extremal dependence properties of Gaussian scale mixtures and we unify and
extend general results on their joint tail decay rates in both asymptotic
dependence and independence cases. Motivated by the analysis of spatial
extremes, we propose several flexible yet parsimonious parametric copula models
that smoothly interpolate from asymptotic dependence to independence and
include the Gaussian dependence as a special case. We show how these new models
can be fitted to high threshold exceedances using a censored likelihood
approach, and we demonstrate that they provide valuable information about tail
characteristics. Our parametric approach outperforms the widely used
nonparametric $\chi$ and $\bar\chi$ statistics often used to guide model choice
at an exploratory stage by borrowing strength across locations for better
estimation of the asymptotic dependence class. We demonstrate the capacity of
our methodology by adequately capturing the extremal properties of wind speed
data collected in the Pacific Northwest, US.


title:
Enhanced Performance of Dye-Sensitized Solar Cells based on TiO2
  Nanotube Membranes using Optimized Annealing Profile

abstract:
  We use free-standing TiO2 nanotube membranes that are transferred onto FTO
slides in front-side illuminated dye-sensitized solar cells (DSSCs). We
investigate the key parameters for solar cell arrangement of self-ordered
anodic TiO2 nanotube layers on the FTO substrate and namely the influence of
the annealing procedure on the DSSC light conversion efficiency. The results
show that using an optimal temperature annealing profile can significantly
enhance the DSSC efficiency (in our case 9.8 %), as it leads to a markedly
lower density of trapping states in the tube oxide, and thus to strongly
improved electron transport properties.


title:
Second-order fluctuation theory and time autocorrelation function for
  currents

abstract:
  By using recent developments for the Langevin dynamics of spatially
asymmetric systems, we routinely generalize the Onsager-Machlup fluctuation
theory of the second order in time. In this form, it becomes applicable to
fluctuating variables, including hydrodynamic currents, in equilibrium as well
as nonequilibrium steady states. From the solution of the obtained stochastic
equations we derive an analytical expression for the time autocorrelation
function of a general fluctuating quantity. This theoretical result is then
tested in a study of a shear flow by molecular dynamics simulations. The
proposed form of the time autocorrelation function yields an excellent fit to
our computational data for both equilibrium and nonequilibrium steady states.
Unlike the analogous result of the first-order Onsager-Machlup theory, our
expression correctly describes the short-time correlations. Its utility is
demonstrated in an application of the Green-Kubo formula for the transport
coefficient. Curiously, the normalized time autocorrelation function for the
shear flow, which only depends on the deterministic part of the fluctuation
dynamics, appears independent of the external shear force in the linear
nonequilibrium regime.


title: Extended models of nonlinear waves in liquid with gas bubbles

abstract:
  In this work we generalize the models for nonlinear waves in a gas--liquid
mixture taking into account an interphase heat transfer, a surface tension and
a weak liquid compressibility simultaneously at the derivation of the equations
for nonlinear waves. We also take into consideration high order terms with
respect to the small parameter. Two new nonlinear differential equations are
derived for long weakly nonlinear waves in a liquid with gas bubbles by the
reductive perturbation method considering both high order terms with respect to
the small parameter and the above mentioned physical properties. One of these
equations is the perturbation of the Burgers equation and corresponds to main
influence of dissipation on nonlinear waves propagation. The other equation is
the perturbation of the Burgers--Korteweg--de Vries equation and corresponds to
main influence of dispersion on nonlinear waves propagation.


title:
N term pairwise correlation inequalities, steering and joint
  measurability

abstract:
  Chained correlation inequalities involving pairwise correlations of qubit
observables in the equatorial plane are constructed based on the positivity of
a sequence of moment matrices. When a jointly measurable set of fuzzy POVMs is
employed in first measurement of every pair of sequential measurements, the
chained pairwise correlations do not violate the classical bound imposed by the
moment matrix positivity. We identify that incompatibility of measurements is
only necessary, but not sufficient, in general, for the violation of the
inequality. On the other hand, there exists a one-to-one equivalence between
the degree of incompatibility (which quantifies the joint measurability) of the
equatorial qubit observables and the optimal violation of a non-local steering
inequality, proposed by Jones and Wiseman (Phys. Rev. A, 84, 012110 (2011)). To
this end, we construct a local analogue of this steering inequality in a single
qubit system and show that its violation is a mere reflection of measurement
incompatibility of equatorial qubit POVMs, employed in first measurements in
the sequential unsharp-sharp scheme.


title: LAMOST Observations of Flaring M Dwarfs in the Kepler Field

abstract:
  A sample of the LAMOST spectra of the early type M0-M3 dwarfs is compared
with the Kepler observations. It is found that M dwarfs with strong
chromospheric emission in $H_{\alpha}$ have large flare activity in general.
The rotational periods derived from the Kepler measurements have close
correlations with the sizes of the flares, the power-law distribution index and
the equivalent widths of the $H_{\alpha}$ emission. A clear trend exists for
higher magnetic activities being detected in faster rotating M dwarfs (rotation
periods $<$ 20 day).


title: On Duality Of Multiple Target Tracking and Segmentation

abstract:
  Traditionally, object tracking and segmentation are treated as two separate
problems and solved independently. However, in this paper, we argue that
tracking and segmentation are actually closely related and solving one should
help the other. On one hand, the object track, which is a set of bounding boxes
with one bounding box in every frame, would provide strong high-level guidance
for the target/background segmentation task. On the other hand, the object
segmentation would separate object from other objects and background, which
will be useful for determining track locations in every frame. We propose a
novel framework which combines online multiple target tracking and segmentation
in a video. In our approach, the tracking and segmentation problems are coupled
by Lagrange dual decomposition, which leads to more accurate segmentation
results and also \emph{helps resolve typical difficulties in multiple target
tracking, such as occlusion handling, ID-switch and track drifting}. To track
targets, an individual appearance model is learned for each target via
structured learning and network flow is employed to generate tracks from
densely sampled candidates. For segmentation, multi-label Conditional Random
Field (CRF) is applied to a superpixel based spatio-temporal graph in a segment
of video to assign background or target labels to every superpixel. The
experiments on diverse sequences show that our method outperforms
state-of-the-art approaches for multiple target tracking as well as
segmentation.


title: Constructing of constraint preserving scheme for Einstein equations

abstract:
  We propose a new numerical scheme of evolution for the Einstein equations
using the discrete variational derivative method (DVDM). We derive the discrete
evolution equation of the constraint using this scheme and show the constraint
preserves in the discrete level. In addition, to confirm the numerical
stability using this scheme, we perform some numerical simulations by
discretized equations with the Crank-Nicolson scheme and with the new scheme,
and we find that the new discretized equations have better stability than that
of the Crank-Nicolson scheme.


title: Computing the K-terminal Reliability of Circle Graphs

abstract:
  Let G denote a graph and let K be a subset of vertices that are a set of
target vertices of G. The K-terminal reliability of G is defined as the
probability that all target vertices in K are connected, considering the
possible failures of non-target vertices of G. The problem of computing
K-terminal reliability is known to be #P-complete for polygon-circle graphs,
and can be solved in polynomial-time for t-polygon graphs, which are a subclass
of polygon-circle graphs. The class of circle graphs is a subclass of
polygon-circle graphs and a superclass of t-polygon graphs. Therefore, the
problem of computing K-terminal reliability for circle graphs is of particular
interest. This paper proves that the problem remains #P-complete even for
circle graphs. Additionally, this paper proposes a linear-time algorithm for
solving the problem for proper circular-arc graphs, which are a subclass of
circle graphs and a superclass of proper interval graphs.


title:
Proton-proton fusion and tritium $\beta$-decay from lattice quantum
  chromodynamics

abstract:
  The nuclear matrix element determining the $pp\to d e^+ \nu$ fusion cross
section and the Gamow-Teller matrix element contributing to tritium
$\beta$-decay are calculated with lattice Quantum Chromodynamics (QCD) for the
first time. Using a new implementation of the background field method, these
quantities are calculated at the SU(3)-flavor-symmetric value of the quark
masses, corresponding to a pion mass of $m_\pi$ ~ 806 MeV. The Gamow-Teller
matrix element in tritium is found to be 0.979(03)(10) at these quark masses,
which is within $2\sigma$ of the experimental value. Assuming that the
short-distance correlated two-nucleon contributions to the matrix element
(meson-exchange currents) depend only mildly on the quark masses, as seen for
the analogous magnetic interactions, the calculated $pp\to d e^+ \nu$
transition matrix element leads to a fusion cross section at the physical quark
masses that is consistent with its currently accepted value. Moreover, the
leading two-nucleon axial counterterm of pionless effective field theory is
determined to be $L_{1,A}=3.9(0.1)(1.0)(0.3)(0.9)\ {\rm fm}^3$ at a
renormalization scale set by the physical pion mass, also in agreement with the
accepted phenomenological range. This work concretely demonstrates that weak
transition amplitudes in few-nucleon systems can be studied directly from the
fundamental quark and gluon degrees of freedom and opens the way for subsequent
investigations of many important quantities in nuclear physics.


title: Ten Simple Rules for Making Research Software More Robust

abstract:
  Software produced for research, published and otherwise, suffers from a
number of common problems that make it difficult or impossible to run outside
the original institution, or even off the primary developer's computer. We
present ten simple rules to make such software robust enough to run anywhere,
and inspire confidence in your reproducibility, and thereby delight your users
and collaborators.


title:
Impact of surface reflection on transmission eigenvalue statistics and
  energy distributions inside random media

abstract:
  The impact of surface reflection upon transmission through and energy
distributions within random media has generally been described in terms of the
boundary extrapolation lengths $z_b, z_b'$ at the input and output end of an
open sample, which are the distance beyond the sample surfaces at which the
energy density within the sample extrapolates to zeroThe importance of
reflection at the sample boundaries plays a key role in the scaling of
transmission. Here we consider the impact of surface reflection on the
propagation of diffusive waves in terms of the modification of the distribution
of transmission eigenvalues (DTE). We review our finding of a transition in the
analytical form of the DTE at the point that the sample length equals
$|z_b-z_b'|$. The highest transmission eigenvalue for stronger asymmetry in
boundary reflection is strictly smaller than unity. The average transmission
and profiles of energy density inside the sample can still be described in
terms of the sample length, $L$, and the boundary extrapolation lengths on both
sides of the sample, $z_b, z_b'$. For localized waves, we find the energy
density profile within the sample is a segment of the distribution that would
be found in a longer sample with length $L+z_b+z_b'$. These results suggest new
ways of controlling wave interference in both diffusive and localized systems
by varying boundary reflectivity.


title: Polaritons in layered 2D materials

abstract:
  In recent years, enhanced light-matter interactions through a plethora of
dipole-type polaritonic excitations have been observed in two-dimensional (2D)
layered materials. In graphene, electrically tunable and highly confined
plasmon-polaritons were predicted and observed, opening up opportunities for
optoelectronics, bio-sensing and other mid-infrared applications. In hexagonal
boron nitride (hBN), low-loss infrared-active phonon-polaritons exhibit
hyperbolic behavior for some frequencies, allowing for ray-like propagation
exhibiting high quality factors and hyperlensing effects. In transition metal
dichalcogenides (TMDs), reduced screening in the 2D limit leads to optically
prominent excitons with large binding energy, with these polaritonic modes
having been recently observed with scanning near field optical microscopy
(SNOM). Here, we review recent progress in state-of-the-art experiments, survey
the vast library of polaritonic modes in 2D materials, their optical spectral
properties, figures-of-merit and application space. Taken together, the
emerging field of 2D material polaritonics and their hybrids provide enticing
avenues for manipulating light-matter interactions across the visible, infrared
to terahertz spectral ranges, with new optical control beyond what can be
achieved using traditional bulk materials.


title: Random walk in degree space and the time-dependent Watts-Strogatz model

abstract:
  In this work, we propose a scheme that provides an analytical estimate for
the time-dependent degree distribution of some networks. This scheme maps the
problem into a random walk in degree space, and then we choose the paths that
are responsible for the dominant contributions. The method is illustrated on
the dynamical versions of the Erd\"os-R\'enyi and Watts-Strogatz graphs, which
were introduced as static models in the original formulation. We have succeeded
in obtaining an analytical form for the dynamics Watts-Strogatz model, which is
asymptotically exact for some regimes.


title:
Forward Stochastic Reachability Analysis for Uncontrolled Linear Systems
  using Fourier Transforms

abstract:
  We propose a scalable method for forward stochastic reachability analysis for
uncontrolled linear systems with affine disturbance. Our method uses Fourier
transforms to efficiently compute the forward stochastic reach probability
measure (density) and the forward stochastic reach set. This method is
applicable to systems with bounded or unbounded disturbance sets. We also
examine the convexity properties of the forward stochastic reach set and its
probability density. Motivated by the problem of a robot attempting to capture
a stochastically moving, non-adversarial target, we demonstrate our method on
two simple examples. Where traditional approaches provide approximations, our
method provides exact analytical expressions for the densities and probability
of capture.


title:
Tonal consonance parameters link microscopic and macroscopic properties
  of music exposing a hidden order in melody

abstract:
  Consonance is related to the perception of pleasantness arising from a
combination of sounds and has been approached quantitatively using mathematical
relations, physics, information theory, and psychoacoustics. Tonal consonance
is present in timbre, musical tuning, harmony, and melody, and it is used for
conveying sensations, perceptions, and emotions in music. It involves the
physical properties of sound waves and is used to study melody and harmony
through musical intervals and chords. From the perspective of complexity, the
macroscopic properties of a system with many parts frequently rely on the
statistical properties of its constituent elements. Here we show how the tonal
consonance parameters for complex tones can be used to study complexity in
music. We apply this formalism to melody, showing that melodic lines in musical
pieces can be described in terms of the physical properties of melodic
intervals and the existence of an entropy extremalization principle subject to
psychoacoustic macroscopic constraints with musical meaning. This result
connects the human perception of consonance with the complexity of human
creativity in music through the physical properties of the musical stimulus.

categories: cs.SD cs.IT math.IT physics.data-an physics.soc-ph


title:
Generically Mane set supports uniquely ergodic measure for residual
  cohomology class

abstract:
  In this paper, we proved that for generic Tonelli Lagrangian, there always
exists a residual set $\mathcal{G}\subset H^1(M,\mathbb{R})$ such that \[
\widetilde{\mathcal{M}}(c)=\widetilde{\mathcal{A}}(c)=\widetilde{\mathcal{N}}(c),\quad
\forall c\in\mathcal{G} \] with $\widetilde{\mathcal{M}}(c)$ supports on a
uniquely ergodic measure.


title: Optical phase conjugation with less than a photon per degree of freedom

abstract:
  We demonstrate experimentally that optical phase conjugation can be used to
focus light through strongly scattering media even when far less than a photon
per optical degree of freedom is detected. We found that the best achievable
intensity contrast is equal to the total number of detected photons, as long as
the resolution of the system is high enough. Our results demonstrate that phase
conjugation can be used even when the photon budget is extremely low, such as
in high-speed focusing through dynamic media, or imaging deep inside tissue.


title:
On approximation of solutions of operator-differential equations with
  their entire solutions of exponential type

abstract:
  We consider an equation of the form $y'(t) + Ay(t) = 0, \ t \in [0, \infty)$,
where $A$ is a nonnegative self-adjoint operator in a Hilbert space. We give
direct and inverse theorems on approximation of solutions of this equation with
its entire solutions of exponential type. This establishes a one-to-one
correspondence between the order of convergence to $0$ of the best
approximation of a solution and its smoothness degree. The results are
illustrated with an example, where the operator $A$ is generated by a second
order elliptic differential expression in the space $L_{2}(\Omega)$ \ (the
domain $\Omega \subset \mathbb{R}^{n}$ is bounded with smooth boundary) and a
certain boundary condition.


title:
Experimental Phase Diagram of a One-Dimensional Topological
  Superconductor

abstract:
  Topological superconductors can host Majorana quasiparticles which supersede
the fermion/boson dichotomy and offer a pathway to fault tolerant quantum
computation. In one-dimensional systems zero-energy Majorana states are bound
to the ends of the topologically superconducting regions. An experimental
signature of a Majorana bound state is a conductance peak at zero source-drain
voltage bias in a tunneling experiment. Here, we identify the bulk topological
phase in a semiconductor nanowire coupled to a conventional superconductor. We
map out its phase diagram through the dependence of zero-bias peak on the
chemical potential and magnetic field. Our findings are consistent with
calculations for a finite-length topological nanowire. Knowledge of the phase
diagram makes it possible to predictably tune nanowire segments in and out of
the topological phase, thus controlling the positions and couplings of multiple
Majorana bound states. This ability is a prerequisite for Majorana braiding, an
experiment in which Majorana quantum states are exchanged in order to both
demonstrate their non-abelian character and realize topological quantum bits.


title: Solvation of Mg in Helium-4: Are there Meta-stable Mg Dimers ?

abstract:
  Experiments on the formation of magnesium complexes in $^4$He nanodroplets
were interpreted as the observation of the formation of weakly bound magnesium
complexes. We present results for single Mg and Mg dimer solvation using the
hypernetted chain / Euler-Lagrange method as well as path integral Monte Carlo
simulations. We find that the phonon-mediated, indirect Mg-Mg interaction adds
an oscillatory component to the direct Mg-Mg interaction. We undertake a
step-by-step examination of the ingredients of the calculation of the
phonon-induced interaction, comparing the results of semi-analytic HNC-EL
calculations for bulk and single impurity results with experiments as well as
Monte Carlo data. We do not find evidence for a sufficiently strong secondary
minimum in the effective Mg-Mg interaction to support a metastable state.


title: Gauge theory on Aloff-Wallach spaces

abstract:
  For gauge groups $U(1)$ and $SO(3)$ we classify invariant $G_2$-instantons
for homogeneous coclosed $G_2$-structures on Aloff-Wallach spaces $X_{k,l}$. As
a consequence, we give examples where $G_2$-instantons can be used to
distinguish between different strictly nearly parallel $G_2$-structures on the
same Aloff-Wallach space. In addition to this, we find that while certain
$G_2$-instantons exist for the strictly nearly parallel $G_2$-structure on
$X_{1,1}$, no such $G_2$-instantons exist for the tri-Sasakian one. As a
further consequence of the classification, we produce examples of some other
interesting phenomena, such as: irreducible $G_2$-instantons that, as the
structure varies, merge into the same reducible and obstructed one; and
$G_2$-instantons on nearly parallel $G_2$-manifolds that are not locally energy
minimizing.


title: Syzygies of Quadratic Veronese Embedding

abstract:
  In this work we explicitly calculate syzygies of quadratic Veronese embedding
$\mathbb{P}(V)\subset\mathbb{P}(\operatorname{Sym}^2V)$ as representations of
the group $\operatorname{GL}(V)$. Also resolutions of the sheaves
$\mathscr{O}_{\mathbb{P}(V)}(i)$ are constructed in the category
$D(\mathbb{P}(\operatorname{Sym}^2V))$.


title: Natural operations on holomorphic forms

abstract:
  We prove that the only natural differential operations between holomorphic
forms on a complex manifold are those obtained using linear combinations, the
exterior product and the exterior differential. In order to accomplish this
task we first develop the basics of the theory of natural holomorphic bundles
over a fixed manifold, making explicit its Galoisian structure by proving a
categorical equivalence {\it \`a la Galois}.


title:
A new method for measuring the neutron lifetime using an in situ neutron
  detector

abstract:
  The neutron lifetime is important in understanding the production of light
nuclei in the first minutes after the big bang and it provides basic
information on the charged weak current of the standard model of particle
physics. Two different methods have been used to measure the neutron lifetime:
disappearance measurements using bottled ultracold neutrons and decay rate
measurements using neutron beams. The best measurements using these two
techniques give results that differ by nearly 4 standard deviations. In this
paper we describe a new method for measuring surviving neutrons in neutron
lifetime measurements using bottled ultracold neutrons that provides better
characterization of systematic uncertainties and enables higher precision than
previous measurement techniques. We present results obtained using our method.


title:
A new method to test the hypothesis of isotropy of the ultrahigh energy
  cosmic ray flux

abstract:
  We developed a new method in order to detect and quantify a potential
anisotropy in the ultrahigh energy cosmic ray flux. The proposed method is a
new statistical tool based upon the percolation process that is used in physics
to describe the formation of long-range connectivity in random systems.
Specifically, we investigate the dynamic of the arrangement of cosmic rays into
clusters as a function of the maximum angular separation between the arrival
directions of a pair of events. In a first step, we characterize the
percolation process and extract the most sensitive observable through
Monte-Carlo simulations. We then apply the algorithm to the data taken by the
array of surface detectors of the Pierre Auger Observatory up to January 2010.
The strongest signal appears at an energy threshold of 56.74 EeV and an angular
scale of 4 for which the hypothesis of isotropy of the arrival directions of
the highest-energy cosmic rays is rejected at a nearly 90% C.L.


title:
Investigating mass segregation process in globular clusters with Blue
  Straggler Stars: the impact of dark remnants

abstract:
  We present the results of a set of N-body simulations aimed at exploring how
the process of mass segregation (as traced by the spatial distribution of blue
straggler stars, BSSs) is affected by the presence of a population of heavy
dark remnants (as neutron stars and black holes). To this end, clusters
characterized by different initial concentrations and different fractions of
dark remnants have been modeled. We find that an increasing fraction of
stellar-mass black holes significantly delays the mass segregation of BSSs and
the visible stellar component. In order to trace the evolution of BSS
segregation, we introduce a new parameter ($A^+$) that can be easily measured
when the cumulative radial distribution of these stars and a reference
population are available. Our simulations show that $A^+$ might also be used as
an approximate indicator of the time remaining to the core collapse of the
visible component.


title: Are Accuracy and Robustness Correlated?

abstract:
  Machine learning models are vulnerable to adversarial examples formed by
applying small carefully chosen perturbations to inputs that cause unexpected
classification errors. In this paper, we perform experiments on various
adversarial example generation approaches with multiple deep convolutional
neural networks including Residual Networks, the best performing models on
ImageNet Large-Scale Visual Recognition Challenge 2015. We compare the
adversarial example generation techniques with respect to the quality of the
produced images, and measure the robustness of the tested machine learning
models to adversarial examples. Finally, we conduct large-scale experiments on
cross-model adversarial portability. We find that adversarial examples are
mostly transferable across similar network topologies, and we demonstrate that
better machine learning models are less vulnerable to adversarial examples.


title: Vacua Morghulis

abstract:
  We conjecture that all vacua in string theory decay. More precisely,
non-supersymmetric vacua in string theory are at most metastable and eventually
decay, while supersymmetric vacua are only marginally stable. All de Sitter
vacua with small cosmological constant are metastable to decay via a process
that occurs on scales small compared to the horizon size.


title: Turbulent transport in 2D collisionless guide field reconnection

abstract:
  Transport in collisionless plasmas is usually called anomalous, being due to
the interaction between the particles and the self-generated turbulence by
their collective interactions. Because of its relevance for astrophysical and
space plasmas, we explore the excitation of turbulence in current sheets prone
to component- or guide-field reconnection, a process not well understood, yet.
We analyze the anomalous transport properties by using 2.5D Particle-in-Cell
(PiC) code simulations. We split off the mean, slow variation (in contrast to
the fast turbulent fluctuations) of the macroscopic observables and determine
the main transport terms of the generalized Ohm's law. We verify our findings
by comparing with the independently determined slowing-down rate of the
macroscopic currents and with the transport terms obtained by the first order
correlations of the turbulent fluctuations. We find that the turbulence is most
intense in the "low density" separatrix region of guide-field reconnection. It
is excited by streaming instabilities, it is mainly electrostatic, "patchy" in
space and so is the associated quasi-periodic anomalous transport. The
remaining irreversible anomalous resistivity can be parametrized by an
effective collision frequency ranging from the local ion-cyclotron to the
lower-hybrid frequency. The contributions to the parallel and the perpendicular
(to the magnetic field) components of the slowly varying, DC-electric fields,
balanced by the turbulence, are similar. This anomalous electric field is,
however, smaller than the contributions of the off-diagonal pressure and
electron inertia terms of the Ohm's law. This result can now be verified by
in-situ measurements of the turbulence, in and around the magnetic reconnection
regions of the Earth's magnetosphere by the multi-spacecraft mission MMS and in
laboratory experiments like MRX and VINETA-II.


title: A study of photons at ultra high energy using Auger surface detector

abstract:
  We present a new method to derive an upper limit on the ultra-high-energy
(UHE) photon flux above a given energy, using the Auger SD events. As previous
studies, it takes advantage of the fundamental differences between showers
induced by hadrons and showers induced by photons (signal rise time, slope of
the Lateral Distribution Function, radius of curvature), but it uses photon
shower simulations adapted to the actually observed SD events, on an
event-by-event basis. In particular, we find that a limited number of
simulations per event allows to reach an upper limit that is very close to the
ideal case that would be obtained with an infinite number of simulations. For
instance, 10 simulated showers per event are sufficient to reach an upper limit
only 10 percent higher than the ideal one. As an illustration, we apply this
method to the SD events reconstructed above 55 EeV, which provides an optimized
upper limit on the photon flux above 150 EeV, and indicate how this can be
easily extended to the lower-energy events, to constrain the photon flux down
to much lower energies.


title: Amplitude analysis of resonant production in three pions

abstract:
  We present some results on the analysis of three pion resonances. The
analyses are motivated by the recent release of the largest data set on
diffractively produced three pions by the COMPASS collaboration. We construct
reaction amplitudes that satisfy fundamental $S$-matrix principles, which
allows the use of models that have physical constraints to be used in fitting
data. The models are motivated by the isobar model that satisfy unitarity
constraints. The model consist of a Deck production amplitude with which final
state interactions are constrained by unitarity. We employ the isobar model
where two of the pions form a quasi-stable particle. The analysis is performed
in the high-energy, single Regge limit. We specifically discuss the examples of
the three pion $J^{PC}=2^{-+}$ resonance in the $\rho\pi$ and $f_2\pi$
channels.


title:
The Robustness and the Doubly-Preferential Attachment Simulation of the
  Consensus Connectome Dynamics of the Human Brain

abstract:
  The increasing quantity and quality of the publicly available human cerebral
diffusion MRI data make possible the study of the brain as it was unimaginable
before. The Consensus Connectome Dynamics (CCD) is a remarkable phenomenon that
was discovered by continuously decreasing the minimum confidence-parameter at
the graphical interface of the Budapest Reference Connectome Server
(\url{http://connectome.pitgroup.org}). The Budapest Reference Connectome
Server depicts the cerebral connections of $n=418$ subjects with a
frequency-parameter $k$: For any $k=1,2,...,n$ one can view the graph of the
edges that are present in at least $k$ connectomes. If parameter $k$ is
decreased one-by-one from $k=n$ through $k=1$ then more and more edges appear
in the graph, since the inclusion condition is relaxed. The surprising
observation is that the appearance of the edges is far from random: it
resembles a growing, complex structure, like a tree or a shrub (visualized on
\url{https://www.youtube.com/watch?v=yxlyudPaVUE}). Here we examine the
robustness of the CCD phenomenon, and we show that it is almost independent of
the particular choice of the set of underlying individual connectomes, yielding
the CCD phenomenon. This result shows that the CCD phenomenon is very likely a
biological property of the human brain and not just a property of the data sets
examined. We also present a simulation that well-describes the growth of the
CCD structure: in our random graph model a doubly-preferential attachment
distribution is found to mimic the CCD: a new edge appear with a probability
proportional to the sum of the degrees of the endpoints of the new edge.


title:
Electron Acceleration in Pulsar-Wind Termination Shocks: An Application
  to the Crab Nebula Gamma-Ray Flares

abstract:
  The {\gamma}-ray flares from the Crab nebula observed by AGILE and Fermi-LAT
reaching GeV energies and lasting several days challenge the standard models
for particle acceleration in pulsar wind nebulae, because the radiating
electrons have energies exceeding the classical radiation-reaction limit for
synchrotron. Previous modeling has suggested that the synchrotron limit can be
exceeded if the electrons experience electrostatic acceleration, but the
resulting spectra do not agree very well with the data. As a result, there are
still some important unanswered questions about the detailed particle
acceleration and emission processes occurring during the flares. We revisit the
problem using a new analytical approach based on an electron transport equation
that includes terms describing electrostatic acceleration, stochastic
wave-particle acceleration, shock acceleration, synchrotron losses, and
particle escape. An exact solution is obtained for the electron distribution,
which is used to compute the associated {\gamma}-ray synchrotron spectrum. We
find that in our model the {\gamma}-ray flares are mainly powered by
electrostatic acceleration, but the contributions from stochastic and shock
acceleration play an important role in producing the observed spectral shapes.
Our model can reproduce the spectra of all the Fermi-LAT and AGILE flares from
the Crab nebula, using magnetic field strengths in agreement with the
multi-wavelength observational constraints. We also compute the spectrum and
duration of the synchrotron afterglow created by the accelerated electrons,
after they escape into the region on the downstream side of the pulsar wind
termination shock. The afterglow is expected to fade over a maximum period of
about three weeks after the {\gamma}-ray flare.


title:
A Quantum Mechanical Bound for Space-Energy Cost with Respect to the Von
  Neumann Entropy

abstract:
  This thesis discusses the possibility of uncertainty relations for space and
energy given a state of fixed entropy. In particular, it discusses the results
in the paper of Dam/Nguyen. There, the authors propose a lower bound for the
mixed cost in energy and space required for physically storing information in a
quantum mechanical system. We first critically examine the justifications for
the bound given in the paper.This is done from a mathematical point of view, in
contrast to the more physically motivated original paper.Then we give two
examples that illustrate the limitations of this inequality. We also present
numerical results to find an alternative energy-space bound in the finite
dimensional version of this problem. They indicate a slightly different version
of the inequality. In the end we describe a promising ansatz to find a lower
energy-space bound that depends on the amount stored information. Unfortunately
that did not result in a satisfactory result.


title:
Khovanov's Heisenberg category, moments in free probability, and shifted
  symmetric functions

abstract:
  We establish an isomorphism between the center of the Heisenberg category
defined by Khovanov and the algebra $\Lambda^*$ of shifted symmetric functions
defined by Okounkov-Olshanski. We give a graphical description of the shifted
power and Schur bases of $\Lambda^*$ as elements of the center, and describe
the curl generators of the center in the language of shifted symmetric
functions. This latter description makes use of the transition and
co-transition measures of Kerov and the noncommutative probability spaces of
Biane.


title: Big Data Analytics in Cloud environment using Hadoop

abstract:
  The Big Data management is a problem right now. The Big Data growth is very
high. It is very difficult to manage due to various characteristics. This
manuscript focuses on Big Data analytics in cloud environment using Hadoop. We
have classified the Big Data according to its characteristics like Volume,
Value, Variety and Velocity. We have made various nodes to process the data
based on their volume, velocity, value and variety. In this work we have
classify the input data and routed to various processing node. At the last
after processing from each node, we can combine the output of all nodes to get
the final result. We have used Hadoop to partition the data as well as process
it.


title: Positive harmonic functions of transformed random walks

abstract:
  In this paper, we will study the behavior of the space of positive harmonic
functions associated with the random walk on a discrete group under the change
of probability measure by a randomized stopping time. We show that this space
remains unchanged after applying a bounded randomized stopping time.


title: Generalization Error of Invariant Classifiers

abstract:
  This paper studies the generalization error of invariant classifiers. In
particular, we consider the common scenario where the classification task is
invariant to certain transformations of the input, and that the classifier is
constructed (or learned) to be invariant to these transformations. Our approach
relies on factoring the input space into a product of a base space and a set of
transformations. We show that whereas the generalization error of a
non-invariant classifier is proportional to the complexity of the input space,
the generalization error of an invariant classifier is proportional to the
complexity of the base space. We also derive a set of sufficient conditions on
the geometry of the base space and the set of transformations that ensure that
the complexity of the base space is much smaller than the complexity of the
input space. Our analysis applies to general classifiers such as convolutional
neural networks. We demonstrate the implications of the developed theory for
such classifiers with experiments on the MNIST and CIFAR-10 datasets.


title: Comparing Face Detection and Recognition Techniques

abstract:
  This paper implements and compares different techniques for face detection
and recognition. One is find where the face is located in the images that is
face detection and second is face recognition that is identifying the person.
We study three techniques in this paper: Face detection using self organizing
map (SOM), Face recognition by projection and nearest neighbor and Face
recognition using SVM.


title: Kernel Alignment Inspired Linear Discriminant Analysis

abstract:
  Kernel alignment measures the degree of similarity between two kernels. In
this paper, inspired from kernel alignment, we propose a new Linear
Discriminant Analysis (LDA) formulation, kernel alignment LDA (kaLDA). We first
define two kernels, data kernel and class indicator kernel. The problem is to
find a subspace to maximize the alignment between subspace-transformed data
kernel and class indicator kernel. Surprisingly, the kernel alignment induced
kaLDA objective function is very similar to classical LDA and can be expressed
using between-class and total scatter matrices. This can be extended to
multi-label data. We use a Stiefel-manifold gradient descent algorithm to solve
this problem. We perform experiments on 8 single-label and 6 multi-label data
sets. Results show that kaLDA has very good performance on many single-label
and multi-label problems.


title: A Survey on Various Data Mining Techniques for ECG Meta Analysis

abstract:
  Data Mining is the process of examining the information from different point
of view and compressing it for the relevant data. This data can also be
utilized to build the incomes. Data Mining is also known as Data or Knowledge
Discovery. The basic purpose of data mining is to search patterns which have
minimal user inputs and efforts. Data Mining plays a very crucial role in the
various fields. There are various data mining procedures which can be connected
in different fields of innovation. By using data mining techniques, it is
observed that less time is taken for the prediction of any disease with more
accuracy. In this paper we would review various data mining techniques which
are categorized under classification, regression and clustering and apply these
algorithms over an ECG dataset. The purpose of this work is to determine the
most suitable data mining technique and use it to improve the accuracy of
analyzing ECG data for better decision making.


title: Improved Strongly Adaptive Online Learning using Coin Betting

abstract:
  This paper describes a new parameter-free online learning algorithm for
changing environments. In comparing against algorithms with the same time
complexity as ours, we obtain a strongly adaptive regret bound that is a factor
of at least $\sqrt{\log(T)}$ better, where $T$ is the time horizon. Empirical
results show that our algorithm outperforms state-of-the-art methods in
learning with expert advice and metric learning scenarios.


title: Automatically tracking neurons in a moving and deforming brain

abstract:
  Advances in optical neuroimaging techniques now allow neural activity to be
recorded with cellular resolution in awake and behaving animals. Brain motion
in these recordings pose a unique challenge. The location of individual neurons
must be tracked in 3D over time to accurately extract single neuron activity
traces. Recordings from small invertebrates like C. elegans are especially
challenging because they undergo very large brain motion and deformation during
animal movement. Here we present an automated computer vision pipeline to
reliably track populations of neurons with single neuron resolution in the
brain of a freely moving C. elegans undergoing large motion and deformation. 3D
volumetric fluorescent images of the animal's brain are straightened, aligned
and registered, and the locations of neurons in the images are found via
segmentation. Each neuron is then assigned an identity using a new
time-independent machine-learning approach we call Neuron Registration Vector
Encoding. In this approach, non-rigid point-set registration is used to match
each segmented neuron in each volume with a set of reference volumes taken from
throughout the recording. The way each neuron matches with the references
defines a feature vector which is clustered to assign an identity to each
neuron in each volume. Finally, thin-plate spline interpolation is used to
correct errors in segmentation and check consistency of assigned identities.
The Neuron Registration Vector Encoding approach proposed here is uniquely well
suited for tracking neurons in brains undergoing large deformations. When
applied to whole-brain calcium imaging recordings in freely moving C. elegans,
this analysis pipeline located 150 neurons for the duration of an 8 minute
recording and consistently found more neurons more quickly than manual or
semi-automated approaches.


title: Two-sample testing in non-sparse high-dimensional linear models

abstract:
  In analyzing high-dimensional models, sparsity of the model parameter is a
common but often undesirable assumption. In this paper, we study the following
two-sample testing problem: given two samples generated by two high-dimensional
linear models, we aim to test whether the regression coefficients of the two
linear models are identical. We propose a framework named TIERS (short for
TestIng Equality of Regression Slopes), which solves the two-sample testing
problem without making any assumptions on the sparsity of the regression
parameters. TIERS builds a new model by convolving the two samples in such a
way that the original hypothesis translates into a new moment condition. A
self-normalization construction is then developed to form a moment test. We
provide rigorous theory for the developed framework. Under very weak conditions
of the feature covariance, we show that the accuracy of the proposed test in
controlling Type I errors is robust both to the lack of sparsity in the
features and to the heavy tails in the error distribution, even when the sample
size is much smaller than the feature dimension. Moreover, we discuss minimax
optimality and efficiency properties of the proposed test. Simulation analysis
demonstrates excellent finite-sample performance of our test. In deriving the
test, we also develop tools that are of independent interest. The test is built
upon a novel estimator, called Auto-aDaptive Dantzig Selector (ADDS), which not
only automatically chooses an appropriate scale of the error term but also
incorporates prior information. To effectively approximate the critical value
of the test statistic, we develop a novel high-dimensional plug-in approach
that complements the recent advances in Gaussian approximation theory.


title:
Nowhere-zero $3$-flow and $\mathbb{Z}_3$-connectedness in Graphs with
  Four Edge-disjoint Spanning Trees

abstract:
  Given a zero-sum function $\beta : V(G) \rightarrow \mathbb{Z}_3$ with
$\sum_{v\in V(G)}\beta(v)=0$, an orientation $D$ of $G$ with
$d^+_D(v)-d^-_D(v)= \beta(v)$ in $\mathbb{Z}_3$ for every vertex $v\in V(G)$ is
called a $\beta$-orientation. A graph $G$ is $\mathbb{Z}_3$-connected if $G$
admits a $\beta$- orientation for every zero-sum function $\beta$. Jaeger et
al. conjectured that every $5$-edge-connected graph is
$\mathbb{Z}_3$-connected. A graph is $\langle\mathbb{Z}_3\rangle$-extendable at
vertex $v$ if any pre-orientation at $v$ can be extended to a
$\beta$-orientation of $G$ for any zero-sum function $\beta$. We observe that
if every $5$-edge-connected essentially $6$-edge-connected graph is
$\langle\mathbb{Z}_3\rangle$-extendable at any degree five vertex, then the
above mentioned conjecture by Jaeger et al. holds as well. Furthermore,
applying the partial flow extension method of Thomassen and of Lov\'{a}sz et
al., we prove that every graph with at least 4 edge-disjoint spanning trees is
$\mathbb{Z}_3$-connected. Consequently, every $5$-edge-connected essentially
$23$-edge-connected graph is $\langle\mathbb{Z}_3\rangle$-extendable at degree
five vertex.


title: The Khovanov homology of infinite braids

abstract:
  We show that the limiting Khovanov chain complex of any infinite positive
braid categorifies the Jones-Wenzl projector. This result extends Lev
Rozansky's categorification of the Jones-Wenzl projectors using the limiting
complex of infinite torus braids. We also show a similar result for the
limiting Lipshitz-Sarkar-Khovanov homotopy types of the closures of such
braids. Extensions to more general infinite braids are also considered.


title:
Message-passing algorithms for synchronization problems over compact
  groups

abstract:
  Various alignment problems arising in cryo-electron microscopy, community
detection, time synchronization, computer vision, and other fields fall into a
common framework of synchronization problems over compact groups such as Z/L,
U(1), or SO(3). The goal of such problems is to estimate an unknown vector of
group elements given noisy relative observations. We present an efficient
iterative algorithm to solve a large class of these problems, allowing for any
compact group, with measurements on multiple 'frequency channels' (Fourier
modes, or more generally, irreducible representations of the group). Our
algorithm is a highly efficient iterative method following the blueprint of
approximate message passing (AMP), which has recently arisen as a central
technique for inference problems such as structured low-rank estimation and
compressed sensing. We augment the standard ideas of AMP with ideas from
representation theory so that the algorithm can work with distributions over
compact groups. Using standard but non-rigorous methods from statistical
physics we analyze the behavior of our algorithm on a Gaussian noise model,
identifying phases where the problem is easy, (computationally) hard, and
(statistically) impossible. In particular, such evidence predicts that our
algorithm is information-theoretically optimal in many cases, and that the
remaining cases show evidence of statistical-to-computational gaps.

categories: cs.IT cs.CV cs.DS math.IT math.OC stat.ML


title: The Chow form of a reciprocal linear space

abstract:
  A reciprocal linear space is the image of a linear space under
coordinate-wise inversion. These fundamental varieties describe the analytic
centers of hyperplane arrangements and appear as part of the defining equations
of the central path of a linear program. Their structure is controlled by an
underlying matroid. This provides a large family of hyperbolic varieties,
recently introduced by Shamovich and Vinnikov. Here we give a definite
determinantal representation to the Chow form of a reciprocal linear space. One
consequence is the existence of symmetric rank-one Ulrich sheaves on reciprocal
linear spaces. Another is a representation of the entropic discriminant as a
sum of squares. For generic linear spaces, the determinantal formulas obtained
are closely related to the Laplacian of the complete graph and generalizations
to simplicial matroids. This raises interesting questions about the
combinatorics of hyperbolic varieties and connections with the positive
Grassmannian.


title:
A Technique for Simultaneous Measurement of Circular and Linear
  Polarization with Single-Channel Polarimeter

abstract:
  The algorithm is described, which have been used for photo-polarimetric
monitoring of various astronomical objects - cataclysmic variables, asteroids,
comets.


title: Ant-net: An Adaptive Routing Algorithm

abstract:
  With the increasing demand and complexity of networks, factors such as
balancing the load, improving the performance, reducing delay and finding
optimal path between nodes in a computer network have become crucial. The
traditional routing approaches are not able to perform up to the mark as they
do not take into account factors such as reducing delay and adaptive nature.
Thus there is a need for more sophisticated techniques to meet the current
network problems. This paper focuses on Ant-net algorithm based on Ant colony
optimization which is an adaptive routing algorithm.In this approach, models of
collective intelligence are transformed into optimization techniques. The ants
travel across various paths in the network, thus depositing of pheromone,
collecting route information and congestion. In this paper the Ant-Net
algorithm along the important data structures required has been discussed and
it is implemented on a simple packet switch network. The simulations describe
the adaptive nature of the algorithm


title: On the Progenitor of the Type IIb Supernova 2016gkg

abstract:
  We present a detection in pre-explosion Hubble Space Telescope (HST) imaging
of a point source consistent with being the progenitor star of the Type IIb
supernova (SN IIb) 2016gkg. Post-explosion imaging from the Keck Adaptive
Optics system was used to perform relative astrometry between the Keck and HST
imaging. We identify a single point source in the HST images coincident with
the SN position to 0.89-sigma. The HST photometry is consistent with the
progenitor star being an A0Ia star with T=9500 K and log (L/Lsun)=5.15. We find
that the SN 2016gkg progenitor star appears more consistent with binary than
single-star evolutionary models. In addition, early-time light curve data from
SN 2016gkg revealed a rapid rise in luminosity within ~0.4 days of
non-detection limits, consistent with models of the cooling phase after shock
break-out. We use these data to determine an explosion date of 20.15 September
2016 and progenitor star radius of log (R/Rsun)=2.41, which agrees with
photometry from the progenitor star. Our findings are also consistent with
detections of other SNe IIb progenitor stars, although more luminous and bluer
than most other examples.


title: Deletion of oldest edges in a preferential attachment graph

abstract:
  We consider a variation on the Barab\'asi-Albert random graph process with
fixed parameters $m\in \mathbb{N}$ and $1/2 < p < 1$. With probability $p$ a
vertex is added along with $m$ edges, randomly chosen proportional to vertex
degrees. With probability $1 - p$, the oldest vertex still holding its original
$m$ edges loses those edges. It is shown that the degree of any vertex either
is zero or follows a geometric distribution. If $p$ is above a certain
threshold, this leads to a power law for the degree sequence, while a smaller
$p$ gives exponential tails. It is also shown that the graph contains a unique
giant component whp if and only if $m\geq 2$.


title:
Dynamics of a perfect fluid through velocity potentials with aplication
  in quantum cosmology

abstract:
  We review the Eulerian description of hidrodynamics using Seliger-Whitham's
formalism (in classical case) and Schutz's formalism (in relativistic case). In
these formalisms, the velocity field of a perfect fluid is described by scalar
potentials. With this we can obtain the evolution equations of the fluid and
its Hamiltonian. In the scenario of quantum cosmology the Schutz's formalism
makes it possible to introduce phenomenologically a time variable in
minisuperspace models.


title: Nonnegative kernels and $1$-rectifiability in the Heisenberg group

abstract:
  Let $E$ be an $1$-Ahlfors regular subset of the Heisenberg group
$\mathbb{H}$. We prove that there exists a $-1$-homogeneous kernel $K_1$ such
that if $E$ is contained in a $1$-regular curve the corresponding singular
integral is bounded in $L^2(E)$. Conversely, we prove that there exists another
$-1$-homogeneous kernel $K_2$, such that the $L^2(E)$-boundedness of its
corresponding singular integral implies that $E$ is contained in an $1$-regular
curve. These are the first non-Euclidean examples of kernels with such
properties. Both $K_1$ and $K_2$ are weighted versions of the Riesz kernel
corresponding to the vertical component of $\mathbb{H}$. Unlike the Euclidean
case, where all known kernels related to rectifiability are antisymmetric, the
kernels $K_1$ and $K_2$ are even and nonnegative.


title: The HoTT Library: A formalization of homotopy type theory in Coq

abstract:
  We report on the development of the HoTT library, a formalization of homotopy
type theory in the Coq proof assistant. It formalizes most of basic homotopy
type theory, including univalence, higher inductive types, and significant
amounts of synthetic homotopy theory, as well as category theory and
modalities. The library has been used as a basis for several independent
developments. We discuss the decisions that led to the design of the library,
and we comment on the interaction of homotopy type theory with recently
introduced features of Coq, such as universe polymorphism and private inductive
types.


title: The Recursion Theorem from a Different Angle

abstract:
  This paper is about computability. I claim the likely existence of a program
DoesHalt(Program, Input) such that DoesHalt( HaltsOnItself, AntiSelf ) halts
with resounding 'NO'. HaltsOnItself( Program ) is simply DoesHalt( Program,
Program ). AntiSelf() is a self-referential self-contradictory program that
loops when HaltsOnItself() returns 'YES' and halts when HaltsOnItself() returns
'NO'.


title: Calculation of the Nucleon Axial Form Factor Using Staggered Lattice QCD

abstract:
  The nucleon axial form factor is a dominant contribution to errors in
neutrino oscillation studies. Lattice QCD calculations can help control theory
errors by providing first-principles information on nucleon form factors. In
these proceedings, we present preliminary results on a blinded calculation of
$g_A$ and the axial form factor using HISQ staggered baryons with 2+1+1 flavors
of sea quarks. Calculations are done using physical light quark masses and are
absolutely normalized. We discuss fitting form factor data with the
model-independent $z$ expansion parametrization.


title: Code Definition Analysis for Call Graph Generation

abstract:
  Enterprise level software is implemented using multi-layer architecture.
These layers are often implemented using de-coupled solutions with millions of
lines of code. Programmers often have to track and debug a function call from
user interface layer to the data access layer while troubleshooting an issue.
They have to inspect the code based on search results or use design documents
to construct the call graph. This process is time consuming and laborious. The
development environment tools are insufficient or confined to analyzing only
the code in the loaded solution. This paper proposes a method to construct a
call graph of the call across several layers of the code residing in different
code bases to help programmers better understand the design and architecture of
the software. The signatures of class, methods, and properties were evaluated
and then matched against the code files. A graph of matching functions was
created. The recursive search stopped when there were no matches or the data
layer code was detected. The method resulted in 78.26% accuracy when compared
with manual search.


title:
Signal optimization in urban transport: A totally asymmetric simple
  exclusion process with traffic lights

abstract:
  We consider the exclusion process on a ring with time-dependent defective
bonds at which the hoping rate periodically switches between zero and one. This
system models main roads in city traffics, intersecting with perpendicular
streets. We explore basic properties of the system, in particular dependence of
the vehicular flow on the parameters of signalization as well as the system
size and the car density. We investigate various types of the spatial
distribution of the vehicular density, and show existence of a shock profile.
We also measure waiting time behind traffic lights, and examine its
relationship with the traffic flow.


title:
Magnetic Field Evolution of Spin Blockade in Ge/Si Nanowire Double
  Quantum Dots

abstract:
  We perform transport measurements on double quantum dots defined in Ge/Si
core/shell nanowires and focus on Pauli spin blockade in the regime where tens
of holes occupy each dot. We identify spin blockade through the magnetic field
dependence of leakage current. We find both a dip and a peak in the leakage
current at zero field. We analyze this behavior in terms of the quantum dot
parameters such as coupling to the leads, interdot tunnel coupling as well as
spin-orbit interaction. We find a lower bound for spin-orbit interaction with
$l_{\rm so}=500$ nm. We also extract large and anisotropic effective Land$\rm
\acute{e}$ g-factors, with larger g-factors in the direction perpendicular to
the nanowire axis in agreement with previous studies and experiments but with
larger values reported here.


title: Application of Global Route-Planning Algorithms with Geodesy

abstract:
  Global Route-Planning Algorithms (GRPA) are required to compute paths between
several points located on Earth's surface. A geodesic algorithm is employed as
an auxiliary tool, increasing the precision of distance calculations. This work
presents a novel simulator for GRPA, which compares and evaluates three GRPAs
implemented to solve the shortest path problem for points located at different
cities: A*, LPA*, and D*Lite. The performance of each algorithm is investigated
with a set of experiments, which are executed to check the answers provided by
the algorithms and to compare their execution time. It is shown that GRPAs
implementations with consistent heuristics lead to optimal paths. The
noticeable differences among those algorithms are related to the time execution
after successive executions.


title: Nambu mechanics for stochastic magnetization dynamics

abstract:
  The Landau-Lifshitz-Gilbert (LLG) equation describes the dynamics of a damped
magnetization vector that can be understood as a generalization of Larmor spin
precession. The LLG equation cannot be deduced from the Hamiltonian framework,
by introducing a coupling to a usual bath, but requires the introduction of
additional constraints. It is shown that these constraints can be formulated
elegantly and consistently in the framework of dissipative Nambu mechanics.
This has many consequences for both the variational principle and for
topological aspects of hidden symmetries that control conserved quantities. We
particularly study how the damping terms of dissipative Nambu mechanics affect
the consistent interaction of magnetic systems with stochastic reservoirs and
derive a master equation for the magnetization. The proposals are supported by
numerical studies using symplectic integrators that preserve the topological
structure of Nambu equations. These results are compared to computations
performed by direct sampling of the stochastic equations and by using closure
assumptions for the moment equations, deduced from the master equation.

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


title:
Data-Driven Threshold Machine: Scan Statistics, Change-Point Detection,
  and Extreme Bandits

abstract:
  We present a novel distribution-free approach, the data-driven threshold
machine (DTM), for a fundamental problem at the core of many learning tasks:
choose a threshold for a given pre-specified level that bounds the tail
probability of the maximum of a (possibly dependent but stationary) random
sequence. We do not assume data distribution, but rather relying on the
asymptotic distribution of extremal values, and reduce the problem to estimate
three parameters of the extreme value distributions and the extremal index. We
specially take care of data dependence via estimating extremal index since in
many settings, such as scan statistics, change-point detection, and extreme
bandits, where dependence in the sequence of statistics can be significant. Key
features of our DTM also include robustness and the computational efficiency,
and it only requires one sample path to form a reliable estimate of the
threshold, in contrast to the Monte Carlo sampling approach which requires
drawing a large number of sample paths. We demonstrate the good performance of
DTM via numerical examples in various dependent settings.