title:
Uniqueness of viscosity mean curvature flow solution in two
  sub-Riemannian structures

abstract:
  Here we provide a uniqueness result for viscosity solutions to sub-Riemannian
mean curvature flow. In this setting the uniqueness cannot be deduced via
comparison principle, which is known only for graphs and for radially symmetric
surfaces, due to the presence of characteristic points. Here we prove that any
viscosity solution is limit of a sequence of solutions of Riemannian flow, and
obtain as a consequence uniqueness and comparison principle already known in
the approximating riemannian setting. The results are provided in the settings
of both 3-dimensional rototranslation group SE(2) and Carnot groups of step 2,
which are particularly important due to their relation to surface completion
problem of model of the visual cortex.


title:
Gravitational lens optical scalars in terms of energy-momentum
  distributions in the cosmological framework

abstract:
  We present new results on gravitational lensing over a cosmological
Robertson-Walker backgrounds which extend and generalize previous works. Our
expressions show the presence of new terms and factors which have been
neglected in the literature on the subject. The new equations derived here for
the optcal scalars allow to deal with more general matter content including
sources with non Newtonian components of the energy-momentum tensor and
arbitrary motion.
  Our treatment is within the framework of weak gravitational lenses in which
first order effects of the curvature are considered. We have been able to make
all calculations without referring to the concept of deviation angle. This in
turn, makes the presentation shorter but also allows for the consideration of
global effects on the Robertson-Walker background that have been neglected in
the literature.
  We also discuss two intensity magnification, that we define in this article;
one coming from a natural geometrical contruction in terms of the affine
distance, that here we call $\tilde{\mu}$, and the other adapted to
cosmological discussions in terms of the redshift, that we call $\mu'$. We show
that the natural intensity magnification $\tilde{\mu}$ coincides with the
standard solid angle magnification ($\mu$).


title:
Comparative Salt Tolerance Study of Some Acacia Species at Seed
  Germination Stage

abstract:
  Objective: The purpose of this study was to assess and compare the seed
germination response of six Acacia species under different NaCl concentrations
in order to explore opportunities for selection and breeding salt tolerant
genotypes. Methodology: Germination of seeds was evaluated under salt stresses
using 5 treatment levels: 0, 100, 200, 300 and 400 mM of NaCl. Corrected
germination rate (GC), germination rate index (GRI) and mean germination time
(MGT) were recorded during 10 days. Results: The results indicated that
germination was significantly reduced in all species with the increase in NaCl
concentrations. However, significant interspecific variation for salt tolerance
was observed. The greatest variability in tolerance was observed at moderate
salt stress (200 mM of NaCl) and the decrease in germination appeared to be
more accentuated in A. cyanophylla and A. cyclops. Although, A. raddiana,
remains the most interesting, it preserved the highest percentage (GC = 80%)
and velocity of germination in all species studied in this study, even in the
high salt levels. This species exhibited a particular adaptability to salt
environment, at least at this stage in the life cycle and could be recommended
for plantation establishment in salt affected areas. On the other hand, when
ungerminated seeds were transferred from NaCl treatments to distilled water,
they recovered largely their germination without a lag period and with high
speed. This indicated that the germination inhibition was related to a
reversible osmotic stress that induced dormancy rather than specific ion
toxicity. Conclusion: This ability to germinate after exposure to higher
concentrations of NaCl suggests that studied species, especially the most
tolerant could be able to germinate under the salt affected soils and could be
utilized for the rehabilitation of damaged arid zones.


title:
Scale dependence of open $c\bar{c}$ and $b\bar{b}$ production in the low
  $x$ region

abstract:
  The `optimal' factorization scale $\mu_0$ is calculated for open heavy quark
production. We find that the optimal value is $\mu_F=\mu_0\simeq
0.85\sqrt{p^2_T+m_Q^2} $; a choice which allows us to resum the
double-logarithmic, $(\alpha_s\ln\mu^2_F\ln(1/x))^n$ corrections (enhanced at
LHC energies by large values of $\ln(1/x)$) and to move them into the incoming
parton distributions, PDF$(x,\mu_0^2)$. Besides this result for the single
inclusive cross section (corresponding to an observed heavy quark of transverse
momentum $p_T$), we also determined the scale for processes where the
acoplanarity can be measured; that is, events where the azimuthal angle between
the quark and the antiquark may be determined experimentally. Moreover, we
discuss the important role played by the $2\to 2$ subprocesses, $gg\to
Q\bar{Q}$ at NLO and higher orders. In summary, we achieve a better stability
of the QCD calculations, so that the data on $c\bar{c}$ and $b\bar{b}$
production can be used to further constrain the gluons in the small $x$,
relatively low scale, domain, where the uncertainties of the global analyses
are large at present.


title:
Solution to the one-dimensional Rayleigh-Plesset equation by the
  Differential Transform method

abstract:
  The differential transform method (DTM) is a relatively new technique that
may be used to find a series solution to differential equations (both linear
and nonlinear) through an iterative process. This brief manuscript is an
initial effort in applying the DTM to provide a series solution to the
one-dimensional Rayleigh-Plesset equation (RPE).


title:
Toward High Precision Seismic Studies of White Dwarf Stars:
  Parametrization of the Core and Tests of Accuracy

abstract:
  We present a prescription for parametrizing the chemical profile in the core
of white dwarfs in the light of the recent discovery that pulsation modes may
sometimes be deeply confined in some cool pulsating white dwarfs. Such modes
may be used as unique probes of the complicated chemical stratification that
results from several processes that occurred in previous evolutionary phases of
intermediate-mass stars. This effort is part of our ongoing quest for more
credible and realistic seismic models of white dwarfs using static,
parametrized equilibrium structures. Inspired from successful techniques
developed in design optimization fields (such as aerodynamics), we exploit
Akima splines for the tracing of the chemical profile of oxygen (carbon) in the
core of a white dwarf model. A series of tests are then presented to better
seize the precision and significance of the results that can be obtained in an
asteroseismological context. We also show that the new parametrization passes
an essential basic test, as it successfully reproduces the chemical
stratification of a full evolutionary model.


title:
A generalization of parallelograms involving inscribed ellipses,
  conjugate diameters, and tangency chords

abstract:
  A convex quadrilateral, $Q$, is called a midpoint diagonal quadrilateral if
the intersection point of the diagonals of $Q$ coincides with the midpoint of
at least one of the diagonals of $Q$. A parallelogram, P, is a special case of
a midpoint diagonal quadrilateral since the diagonals of P bisect one another.
We prove two results about ellipses inscribed in midpoint diagonal
quadrilaterals, which generalize properties of ellipses inscribed in
parallelograms involving convex quadrilaterals. First, $Q$ is a midpoint
diagonal quadrilateral if and only if each ellipse inscribed in $Q$ has
tangency chords which are parallel to one of the diagonals of $Q$. Second, $Q$
is a midpoint diagonal quadrilateral if and only if each ellipse inscribed in
$Q$ has a pair of conjugate diameters parallel to the diagonals of $Q$.
Finally, we show that there is a unique ellipse, $E_I$, of minimal eccentricity
incribed in a midpoint diagonal quadrilateral, $Q$, and we show that the equal
conjugate diameters of $E_I$ are parallel to the diagonals of $Q$.


title:
Bismuth based Half Heusler Alloys with giant thermoelectric figure of
  merit

abstract:
  Half Heusler (HH) thermoelectric alloys provide a wide platform to choose
materials with non-toxic and earth abundant elements. This article presents an
ab-initio theoretical evaluation of electrical and thermal transport properties
of three Bismuth-based most promising thermoelectric alloys, selected out of 54
stable HH compounds. These are brand new compounds which are recently proposed
to be stable (Nature Chem. 7, 308 (2015)) and may have interesting properties.
The calculated band structure of the three compounds, namely HfRhBi, ZrIrBi and
ZrRhBi, served as a hint for their promising thermoelectric properties. To gain
confidence on the theoretical predictions of these unreported systems, we first
checked our calculated results for a well studied similar compound, ZrNiSn, and
showed reasonable agreement with the measured ones. HfRhBi and ZrIrBi turn out
to be narrow band gap while ZrRhBi is a moderate band gap semiconductor. A
detailed study of the carrier concentration and temperature dependance of the
Seebeck coefficient (S), Power factor (S$^2 \sigma$), lattice ($\kappa_L$) and
electronic ($\kappa_e$) thermal conductivity and hence the figure of merit (ZT)
is carried out. In contrast to most promising known thermoelectric materials,
we found high power factor for these materials (highest S$^2 \sigma\sim$17.36
mWm$^{-1}$K$^{-2}$ for p-type ZrIrBi). All the three systems (specially p-type)
show high figure of merit, with ZT value as high as 0.45 for ideal crystal.
Maximum ZT and the corresponding optimal n- and p-type doping concentrations
($n_c$) are calculated for all the three compounds, which shall certainly pave
guidance to future experimental work.


title:
Production of phi-mesons on nuclear targets in the Quark-Gluon String
  model

abstract:
  We consider the experimental data on phi-meson production on nuclear targets,
and we find that they present unusually small shadow corrections for the
inclusive density in the midrapidity region. We also give a quantitatively
consistent description of both the initial energy dependence and the
A-dependence of the produced phi-mesons, obtained in the frame of the
Quark-Gluon String Model.


title: Practical definition of averages of tensors in general relativity

abstract:
  We present a definition of tensor fields which are average of tensors over a
manifold, with a straightforward and natural definition of derivative for the
averaged fields; which in turn makes a suitable and practical construction for
the study of averages of tensor fields that satisfy differential equations.
Although we have in mind applications to general relativity, our presentation
is applicable to a general n-dimensional manifold. The definition is based on
the integration of scalars constructed from a physically motivated basis,
making use of the least amount of geometrical structure. We also present
definitions of covariant derivative of the averaged tensors and Lie derivative.


title:
SU(3) Polyakov linear-sigma model: Conductivity and viscous properties
  of QCD matter in thermal medium

abstract:
  In mean field approximation, the grand canonical potential of SU(3) Polyakov
linear-$\sigma$ model (PLSM) is analysed for chiral phase-transition,
$\sigma_l$ and $\sigma_s$ and for deconfinement order-parameters, $\phi$ and
$\phi^*$ of light- and strange-quarks, respectively. Various PLSM parameters
are determined from the assumption of global minimization of the real part of
the potential. Then, we have calculated the subtracted condensates
($\Delta_{l,s}$). All these results are compared with recent lattice QCD
simulations. Accordingly, essential PLSM parameters are determined. The
modelling of the relaxation time is utilized in estimating the conductivity
properties of the QCD matter in thermal medium, namely electric
[$\sigma_{el}(T)$] and heat [$\kappa(T)$] conductivities. We found that the
PLSM results on the electric conductivity and on the specific heat agree well
with the available lattice QCD calculations. Also, we have calculated bulk and
shear viscosities normalized to the thermal entropy, $\xi/s$ and $\eta/s$,
respectively, and compared them with recent lattice QCD. Predictions for $(\xi
/s)/(\sigma_{el}/T)$ and $(\eta/s)/(\sigma_{el}/ T)$ are introduced. We
conclude that our results on various transport properties show some essential
ingredients, that these properties likely come up with, in studying QCD matter
in thermal and dense medium.


title:
Tunneling frustration induced peculiar supersolid phases in the extended
  Bose-Hubbard model

abstract:
  By using a state of art tensor network state method, we study the
ground-state phase diagram of an extended Bose-Hubbard model on the square
lattice with frustrated next-nearest neighboring tunneling. In the hardcore
limit, tunneling frustration stabilizes a peculiar half supersolid (HSS) phase
with one sublattice being superfluid and the other sublattice being Mott
Insulator away from half filling. In the softcore case, the model shows very
rich phase diagrams above half filling, including three different types of
supersolid phases depending on the interaction parameters. The considered model
provides a promising route to experimentally search for novel stable supersolid
state induced by frustrated tunneling in below half filling region with dipolar
atoms or molecules.


title:
"RollRoller" Novel Spherical Mobile Robot Basic Dynamical Analysis and
  Motion Simulations

abstract:
  This paper introduces novel air actuated spherical robot called "RollRoller".
The RollRoller robot consists of two essential parts: tubes covered with a
shell as a frame and mechanical controlling parts to correspond movements. The
RollRoller is proposed to be high potential alternative for exploration and
rescue missions robots because robot utilizing its locomotion via all possible
deriving methods (gravity, torque and angular momentum forces). In beginning ,
characteristic and role of each of component and features were explained. Next,
to determine the uniqueness of this robot, the known and other extra possible
motions are shown by proposing their own algorithmic movements. To illustrate
main motion of this robot was inherent to mathematical models, the forward
direction dynamical behavior on flat surface was derived. Additionally, Matlab
Simulink was used to plot the results to validate the behavior for both
fractional and non-fractional terrains. Lastly, after designing the model of
robot in Solidworks Program, Adams/View visualization software ( the robot
simulated form ) was utilized to proof the Matlab Simulink results and to show
the more detailed and complete form of locomotion including the forward
direction and circular locomotion in proposed robot.


title:
ERMrest: an entity-relationship data storage service for web-based,
  data-oriented collaboration

abstract:
  Scientific discovery is increasingly dependent on a scientist's ability to
acquire, curate, integrate, analyze, and share large and diverse collections of
data. While the details vary from domain to domain, these data often consist of
diverse digital assets (e.g. image files, sequence data, or simulation outputs)
that are organized with complex relationships and context which may evolve over
the course of an investigation. In addition, discovery is often collaborative,
such that sharing of the data and its organizational context is highly
desirable. Common systems for managing file or asset metadata hide their
inherent relational structures, while traditional relational database systems
do not extend to the distributed collaborative environment often seen in
scientific investigations. To address these issues, we introduce ERMrest, a
collaborative data management service which allows general entity-relationship
modeling of metadata manipulated by RESTful access methods. We present the
design criteria, architecture, and service implementation, as well as describe
an ecosystem of tools and services that we have created to integrate metadata
into an end-to-end scientific data life cycle. ERMrest has been deployed to
hundreds of users across multiple scientific research communities and projects.
We present two representative use cases: an international consortium and an
early-phase, multidisciplinary research project.


title: 3He on preplated graphite

abstract:
  By using the diffusion Monte Carlo method, we obtained the full phase diagram
of $^3$He on top of graphite preplated with a solid layer of $^4$He. All the
$^4$He atoms of the substrate were explicitly considered and allowed to move
during the simulation. We found that the ground state is a liquid of density
0.007 $\pm$ 0.001 \AA$^{-2}$, in good agreement with available experimental
data. This is significantly different from the case of $^3$He on clean
graphite, in which both theory and experiment agree on the existence of a
gas-liquid transition at low densities. Upon an increase in $^3$He density, we
predict a first-order phase transition between a dense liquid and a registered
7/12 phase, the 4/7 phase being found metastable in our calculations. At larger
second-layer densities, a final transition is produced to an incommensurate
triangular phase.


title: Enhancing mobile learning security

abstract:
  Mobile devices have been playing vital roles in modern day education delivery
as students can access or download learning materials on their smartphones and
tablets, they can also install educational apps and study anytime, anywhere.
The need to provide adequate security for portable devices being used for
learning cannot be underestimated. In this paper, we present a mobile security
enhancement app, designed and developed for Android smart mobile devices in
order to promote security awareness among students. The app can also identify
major and the most significant security weaknesses, scan or check for
vulnerabilities in m-learning devices and report any security threat.


title:
Factorizations of group determinant in group algebra for any abelian
  subgroup

abstract:
  We give a further extension and generalization of Dedekind's theorem over
those presented by Yamaguchi. In addition, we give two corollaries on
irreducible representations of finite groups and a conjugation of the group
algebra of the groups which have an index-two abelian subgroups.


title: K-Nearest Neighbor Classification Using Anatomized Data

abstract:
  This paper analyzes k nearest neighbor classification with training data
anonymized using anatomy. Anatomy preserves all data values, but introduces
uncertainty in the mapping between identifying and sensitive values. We first
study the theoretical effect of the anatomized training data on the k nearest
neighbor error rate bounds, nearest neighbor convergence rate, and Bayesian
error. We then validate the derived bounds empirically. We show that 1)
Learning from anatomized data approaches the limits of learning through the
unprotected data (although requiring larger training data), and 2) nearest
neighbor using anatomized data outperforms nearest neighbor on
generalization-based anonymization.


title: Fast and Accurate Surface Normal Integration on Non-Rectangular Domains

abstract:
  The integration of surface normals for the purpose of computing the shape of
a surface in 3D space is a classic problem in computer vision. However, even
nowadays it is still a challenging task to devise a method that combines the
flexibility to work on non-trivial computational domains with high accuracy,
robustness and computational efficiency. By uniting a classic approach for
surface normal integration with modern computational techniques we construct a
solver that fulfils these requirements. Building upon the Poisson integration
model we propose to use an iterative Krylov subspace solver as a core step in
tackling the task. While such a method can be very efficient, it may only show
its full potential when combined with a suitable numerical preconditioning and
a problem-specific initialisation. We perform a thorough numerical study in
order to identify an appropriate preconditioner for our purpose. To address the
issue of a suitable initialisation we propose to compute this initial state via
a recently developed fast marching integrator. Detailed numerical experiments
illuminate the benefits of this novel combination. In addition, we show on
real-world photometric stereo datasets that the developed numerical framework
is flexible enough to tackle modern computer vision applications.


title:
A 9.52 dB NCG FEC scheme and 164 bits/cycle low-complexity product
  decoder architecture

abstract:
  Powerful Forward Error Correction (FEC) schemes are used in optical
communications to achieve bit-error rates below $10^{-15}$. These FECs follow
one of two approaches: concatenation of simpler hard-decision codes or usage of
inherently powerful soft-decision codes. The first approach yields lower Net
Coding Gains (NCGs), but can usually work at higher code rates and have lower
complexity decoders. In this work, we propose a novel FEC scheme based on a
product code and a post-processing technique. It can achieve an NCG of 9.52~dB
at a BER of $10^{-15}$ and 9.96~dB at a BER of $10^{-18}$, an error-correction
performance that sits between that of current hard-decision and soft-decision
FECs. A decoder architecture is designed, tested on FPGA and synthesized in 65
nm CMOS technology: its 164 bits/cycle worst-case information throughput can
reach 100 Gb/s at the achieved frequency of 609~MHz. Its complexity is shown to
be lower than that of hard-decision decoders in literature, and an order of
magnitude lower than the estimated complexity of soft-decision decoders.


title:
Unitarity and Lee-Wick prescription at one loop level in the effective
  Myers-Pospelov electrodynamics: the $e^++e^-$ annihilation

abstract:
  We study perturbative unitarity in a Lorentz-symmetry-violating QED model
with higher-order derivative operators in the light of the results of Lee and
Wick to preserve unitarity in indefinite metric theories. Specifically, we
consider the fermionic sector of the Myers-Pospelov model, which includes
dimension-five operators, coupled to standard photons. We canonically quantize
the model, paying attention to its effective character, and show that its
Hamiltonian is stable, emphasizing the exact stage at which the indefinite
metric appears and decomposes into a positive-metric sector and a
negative-metric sector. Finally, we verify the optical theorem at the one-loop
level in the annihilation channel of the forward-scattering process $e^+(p_2,
r) + e^-(p_1,s)$ by applying the Lee-Wick prescription in which the states
associated with the negative metric are left out from the asymptotic Hilbert
space, but nevertheless are considered in the loop integration via the
propagator.


title: Scheduling Broadcasts in a Network of Timelines

abstract:
  Broadcasts and timelines are the primary mechanism of information exchange in
online social platforms today. Services like Facebook, Twitter and Instagram
have enabled ordinary people to reach large audiences spanning cultures and
countries, while their massive popularity has created increasingly competitive
marketplaces of attention. Timing broadcasts to capture the attention of such
geographically diverse audiences has sparked interest from many startups and
social marketing gurus. However, formal study is lacking on both the timing and
frequency problems. We study for the first time the broadcast scheduling
problem of specifying the timing and frequency of publishing content to
maximise the attention received.
  We validate and quantify three interacting behavioural phenomena to
parametrise social platform users: information overload, bursty circadian
rhythms and monotony aversion, which is defined here for the first time. We
formalise a timeline information exchange process based on these phenomena, and
formulate an objective function that quantifies the expected collective
attention. We finally present experiments on real data from Twitter, where we
discover a counter-intuitive scheduling strategy that outperforms popular
heuristics while producing fewer posts.


title:
Chinese Restaurant Process for cognate clustering: A threshold free
  approach

abstract:
  In this paper, we introduce a threshold free approach, motivated from Chinese
Restaurant Process, for the purpose of cognate clustering. We show that our
approach yields similar results to a linguistically motivated cognate
clustering system known as LexStat. Our Chinese Restaurant Process system is
fast and does not require any threshold and can be applied to any language
family of the world.


title: Approximating surface areas by interpolations on triangulations

abstract:
  We consider surface area approximations by Lagrange and Crouzeix--Raviart
interpolations on triangulations. For Lagrange interpolation, we give an
alternative proof for Young's classical result that claims the areas of
inscribed polygonal surfaces converge to the area of the original surface under
the maximum angle condition on the triangulation. For Crouzeix--Raviart
interpolation we show that the approximated surface areas converge to the area
of the original surface without any geometric conditions on the triangulation.


title:
Structural evolution and electronic properties of (Sr1-xCax)2-yIrO4+z
  spin-orbit assisted insulators

abstract:
  The effect of isoelectronic substitution within single crystals of
(Sr1-xCax)2-yIrO4+z is explored. The nominal n=1 Ruddlesden-Popper phase with
y=0, z=0 remains stable from x=0 until x=0.11, where the antiferromagnet
spin-orbit Mott insulating state persists. An increase in the saturated moment
is observed with increasing Ca-substitution, suggesting a modified coupling of
the in-plane moments relative to the in-plane rotation of IrO6 octahedra.
Beyond x=0.11, the x=1/4, y=0, z=1/2 structural phase Sr3CaIr2O9, consisting of
a three-dimensional network of corner sharing octahedra, begins to intermix and
eventually nucleates phase pure crystals at higher starting Ca-content. An
insulating, nonmagnetic ground state is observed in this phase attributable to
the J=0 state and is consistent with a recent powder study. At higher
Ca-concentrations beyond x = 0.75, crystals begin to stabilize in the y=1/3,
z=0 quasi one-dimensional Ca5Ir3O12 structure. The low temperature transport in
this chain-based structure is well described via variable range hopping, and an
antiferromagnetic ordering transition appears below T$_N=9$ K. Our data provide
a detailed mapping of the electronic and structural properties accessible as
the structural framework of the canonical spin orbit Mott insulator Sr2IrO4 is
destabilized via isovalent chemical substitution.


title: Intertwining operators of the quantum Teichm\"uller space

abstract:
  In arXiv:0707.2151 the authors introduced the theory of local representations
of the quantum Teichm\"uller space $\mathcal{T}^q_S$ ($q$ being a fixed
primitive $N$-th root of $(-1)^{N + 1}$) and they studied the behaviour of the
intertwining operators in this theory. One of the main results [Theorem 20,
arXiv:0707.2151] was the possibility to select one distinguished operator (up
to scalar multiplication) for every choice of a surface $S$, ideal
triangulations $\lambda, \lambda'$ and isomorphic local representations $\rho,
\rho'$, requiring that the whole family of operators verifies certain Fusion
and Composition properties. By analyzing the constructions of arXiv:0707.2151,
we found a difficulty that we eventually fix by a slightly weaker (but actually
optimal) selection procedure. In fact, for every choice of a surface $S$, ideal
triangulations $\lambda, \lambda'$ and isomorphic local representations $\rho,
\rho'$, we select a finite set of intertwining operators, naturally endowed
with a structure of affine space over $H_1(S;\mathbb{Z}_N)$ ($\mathbb{Z}_N$ is
the cyclic group of order $N$), in such a way that the whole family of
operators verifies augmented Fusion and Composition properties, which
incorporate the explicit behavior of the $\mathbb{Z}_N$-actions with respect to
such properties. Moreover, this family is minimal among the collections of
operators verifying the "weak" Fusion and Composition rules (in practice the
ones considered in arXiv:0707.2151). In addition, we adapt the derivation of
the invariants for pseudo-Anosov diffeomorphisms and their hyperbolic mapping
tori made in arXiv:0707.2151 and arXiv:math/0407086 by using our distinguished
family of intertwining operators.


title:
Optimization of the ionization time of an atom with tailored laser
  pulses: a theoretical study

abstract:
  How fast can a laser pulse ionize an atom? We address this question by
considering pulses that carry a fixed time-integrated energy per-area, and
finding those that achieve the double requirement of maximizing the ionization
that they induce, while having the shortest duration. We formulate this
double-objective quantum optimal control problem by making use of the Pareto
approach to multi-objetive optimization, and the differential evolution genetic
algorithm. The goal is to find out how much a precise time-profiling of
ultra-fast, large-bandwidth pulses may speed up the ionization process with
respect to simple-shape pulses. We work on a simple one-dimensional model of
hydrogen-like atoms (the P\"oschl-Teller potential), that allows to tune the
number of bound states that play a role in the ionization dynamics. We show how
the detailed shape of the pulse accelerates the ionization process, and how the
presence or absence of bound states influences the velocity of the process.


title:
Coverings, Matchings and the number of maximal independent sets of
  graphs

abstract:
  We determine the maximum number of maximal independent sets of arbitrary
graphs in terms of their covering numbers and we completely characterize the
extremal graphs. As an application, we give a similar result for
K\"onig-Egerv\'ary graphs in terms of their matching numbers.


title: Analytic Materials

abstract:
  The theory of inhomogeneous analytic materials is developed. These are
materials where the coefficients entering the equations involve analytic
functions. Three types of analytic materials are identified. The first two
types involve an integer $p$. If $p$ takes its maximum value then we have a
complete analytic material. Otherwise it is incomplete analytic material of
rank $p$. For two-dimensional materials further progress can be made in the
identification of analytic materials by using the well-known fact that a
$90^\circ$ rotation applied to a divergence free field in a simply connected
domain yields a curl-free field, and this can then be expressed as the gradient
of a potential. Other exact results for the fields in inhomogeneous media are
reviewed. Also reviewed is the subject of metamaterials, as these materials
provide a way of realizing desirable coefficients in the equations.


title: LP-branching algorithms based on biased graphs

abstract:
  We give a combinatorial condition for the existence of efficient, LP-based
FPT algorithms for a broad class of graph-theoretical optimisation problems.
Our condition is based on the notion of biased graphs known from matroid
theory. Specifically, we show that given a biased graph $\Psi=(G,\mathcal{B})$,
where $\mathcal{B}$ is a class of balanced cycles in $G$, the problem of
finding a set $X$ of at most $k$ vertices in $G$ which intersects every
unbalanced cycle in $G$ admits an FPT algorithm using an LP-branching approach,
similar to those previously seen for VCSP problems (Wahlstr\"om, SODA 2014).
This framework captures many of the problems previously solved via the VCSP
approach to LP-branching, as well as new generalisations, such as Group
Feedback Vertex Set for infinite groups (e.g., for graphs whose edges are
labelled by matrices). A major advantage compared to previous work is that it
is immediate to check the applicability of the result for a given problem,
whereas testing applicability of the VCSP approach for a specific VCSP requires
determining the existence of an embedding language with certain algebraically
defined properties, which is not known to be decidable in general.
Additionally, we study the approximation question, and show that every problem
of this category admits an $O(\log \text{OPT})$-approximation.


title: Oscillations in two-person avoidance control

abstract:
  Social interaction dynamics are a special type of group interactions that
play a large part in our everyday lives. They dictate how and with whom a
certain individual will interact. One of such interactions can be termed
"avoidance control". This everyday situation occurs when two fast-walking
persons suddenly realize that they are on a frontal collision course and begin
maneuvering to avoid collision. If the two walkers' initial maneuverings are in
the same direction that can lead to oscillations that lengthen time required to
reach a stable avoidance trajectory. We introduce a dynamical model with a
feedback loop to understand the origin and properties of this oscillation. For
the emergence of the oscillatory behavior, two conditions must be satisfied: i)
the persons must initiate the avoidance maneuver in the same direction; ii) the
time delays in the feedback loop must reverse the phase of the players'
positions at the oscillation frequency. The oscillation can be terminated at
any time if one of the walkers decides to stop and/or to communicate. By taking
over the control of the situation the walker cuts the feedback loop. Similar
oscillatory situations may potentially cause major collisions between
autonomous vehicles and airplanes with airborne communications, but in
autopilot mode.


title: Pressure induced superconductivity in Bi single crystals

abstract:
  Measurements on resistivity and magnetic susceptibility have been carried out
for Bi single crystals under pressures up to 10.5GPa. The temperature dependent
resistivity shows a semimetallic behavior at ambient and low pressures (below
about 1.6GPa). This is followed by an upturn of resistivity in low temperature
region when the pressure is increased, which is explained as a semiconductor
behavior. This feature gradually gets enhanced up to a pressure of about
2.52GPa. Then a non-monotonic temperature dependent resistivity appears upon
further increasing pressure, which is accompanied by a strong suppression to
the low temperature resistivity upturn. Simultaneously, a superconducting
transition occurs at about 3.92K under a pressure of about 2.63GPa. With
further increasing pressure, a second superconducting transition emerges at
about 7K under about 2.8GPa. For these two superconducting states, the
superconductivity induced magnetic screening volumes are quite large. As the
pressure further increased to 8.1GPa, we observe the third superconducting
transition at about 8.2K. The resistivity measurements under magnetic field
allow us to determine the upper critical fields $\mu_0 H_{c2}$ of the
superconducting phases. The upper critical field for the phase with $T_c=3.92$K
is extremely low. Based on the Werthamer-Helfand-Hohenberg (WHH) theory, the
estimated value of $\mu_0 H_{c2}$ for this phase is about 0.103T. While the
upper critical field for the phase with $T_c$=7K is very high with a value of
about 4.56T. Finally, we present a pressure dependent phase diagram of Bi
single crystals. Our results reveal the interesting and rich physics in bismuth
single crystals under high pressure.


title: Long-Term Trends In The Solar Wind Proton Measurements

abstract:
  We examine the long-term time evolution (1965-2015) of the relationships
between solar wind proton temperature (Tp) and speed (Vp) and between the
proton density (np) and speed using OMNI solar wind observations taken near
Earth. We find a long-term decrease in the proton temperature-speed (Tp-Vp)
slope that lasted from 1972 to 2010, but has been trending upward since 2010.
Since the solar wind proton density-speed (np-Vp) relationship is not linear
like the Tp-Vp relationship, we perform power law fits for np-Vp. The exponent
(steepness in the np-Vp relationship) is correlated with the solar cycle. This
exponent has a stronger correlation with current sheet tilt angle than with
sunspot number because the sunspot number maxima vary considerably from cycle
to cycle and the tilt angle maxima do not. To understand this finding, we
examined the average np for different speed ranges, and found that for the slow
wind np is highly correlated with the sunspot number with a lag of ~4 years.
The fast wind np variation was less, but in phase with the cycle. This phase
difference may contribute to the np-Vp exponent correlation with the solar
cycle. These long-term trends are important since empirical formulas based on
fits to Tp and Vp data are commonly used to identify ICMEs, but these formulas
do not include any time dependence. Changes in the solar wind density over a
solar cycle will create corresponding changes in the near Earth space
environment and the overall extent of the heliosphere.


title: Resilience of epidemics on networks

abstract:
  Epidemic propagation on complex networks has been widely investigated, mostly
with invariant parameters. However, the process of epidemic propagation is not
always constant. Epidemics can be affected by various perturbations, and may
bounce back to its original state, which is considered resilient. Here, we
study the resilience of epidemics on networks, by introducing a different
infection rate ${\lambda_{2}}$ during SIS (susceptible-infected-susceptible)
epidemic propagation to model perturbations (control state), whereas the
infection rate is ${\lambda_{1}}$ in the rest of time. Through simulations and
theoretical analysis, we find that even for ${\lambda_{2}<\lambda_{c}}$,
epidemics eventually could bounce back if control duration is below a
threshold. This critical control time for epidemic resilience, i.e.,
${cd_{max}}$ can be predicted by the diameter (${d}$) of the underlying
network, with the quantitative relation ${cd_{max}\sim d^{\alpha}}$. Our
findings can help to design a better mitigation strategy for epidemics.


title: Observer Dependence in Consistent Histories and General Relativity

abstract:
  Observer dependence is central to Quantum Mechanics; in particular if we
associate consistent sets with observer worldviews we can think of the
Consistent Histories (CH) interpretation as a formalisation of observer
dependence. However we lack a theory of the observers themselves. In this paper
we begin by building such a theory within General Relativity (GR), and find
that this framework bears close mathematical resemblance to the treatment of
consistent sets in CH. We therefore adapt the CHSH framework to identify the
`gap' between the classical and quantum theories. We find that the CHSH
argument does not hold on a curved background, so that the inequality may be
violated by classical theories.


title:
Pointer States and Decoherence in Quantum Unitarity: Energy Conservation
  for Weak Interaction Model

abstract:
  The purpose of the present paper is to derive the pointer states of a
macro-object using a simple perturbation method. We study the model Hamiltonian
involving the weak interaction between the center of mass and its environment.
  The main conclusion is that the pointer states emerge as the small part of
the total state vector when the interaction Hamiltonian is not dominant: the
degrees of freedom being at the center of interaction can be localized. In the
weak interaction case, if the disappearance of the energy contribution from the
off-diagonal terms is caused by the decoherence, it threatens the conservation
law. In this study, however, the energy conservation reasonably holds, since
the non-classical (i.e., normal quantum) states give main contribution to it.
  The emergence of the pointer states also implies the special initial state in
which the localized state makes the deep well of the potential. In the result,
the unitary time evolution of a pointer state is very different from that of
the majority of the original state vector of the total system.


title: Fairness as a Program Property

abstract:
  We explore the following question: Is a decision-making program fair, for
some useful definition of fairness? First, we describe how several algorithmic
fairness questions can be phrased as program verification problems. Second, we
discuss an automated verification technique for proving or disproving fairness
of decision-making programs with respect to a probabilistic model of the
population.


title: Minimum Sparsity of Unobservable Power Network Attacks

abstract:
  Physical security of power networks under power injection attacks that alter
generation and loads is studied. The system operator employs Phasor Measurement
Units (PMUs) for detecting such attacks, while attackers devise attacks that
are unobservable by such PMU networks. It is shown that, given the PMU
locations, the solution to finding the sparsest unobservable attacks has a
simple form with probability one, namely, $\kappa(G^M) + 1$, where
$\kappa(G^M)$ is defined as the vulnerable vertex connectivity of an augmented
graph. The constructive proof allows one to find the entire set of the sparsest
unobservable attacks in polynomial time. Furthermore, a notion of the potential
impact of unobservable attacks is introduced. With optimized PMU deployment,
the sparsest unobservable attacks and their potential impact as functions of
the number of PMUs are evaluated numerically for the IEEE 30, 57, 118 and
300-bus systems and the Polish 2383, 2737 and 3012-bus systems. It is observed
that, as more PMUs are added, the maximum potential impact among all the
sparsest unobservable attacks drops quickly until it reaches the minimum
sparsity.


title:
Finiteness of Mapping Class Group Representations from Twisted
  Dijkgraaf-Witten Theory

abstract:
  We show that any twisted Dijkgraaf-Witten representation of a mapping class
group of an orientable, compact surface with boundary has finite image. This
generalizes work of Etingof, Rowell and Witherspoon showing that the braid
group images are finite. In particular, our result answers their question
regarding finiteness of images of arbitrary mapping class group representations
in the affirmative.
  Our approach is to translate the problem into manipulation of colored graphs
embedded in the given surface. To do this translation, we use the fact that any
twisted Dijkgraaf-Witten representation associated to a finite group $G$ and
3-cocycle $\omega$ is isomorphic to a Turaev-Viro-Barrett-Westbury (TVBW)
representation associated to the spherical fusion category
$\text{Vec}_G^\omega$ of twisted $G$-graded vector spaces. As shown by
Kirillov, the representation space for this TVBW representation is canonically
isomorphic to a vector space spanned by $\text{Vec}_G^\omega$-colored graphs
embedded in the surface. By analyzing the action of the Birman generators on a
finite spanning set of colored graphs, we find that the mapping class group
acts by permutations on a slightly larger finite spanning set. This implies
that the representation has finite image.


title: Universality in Chaos of Particle Motion near Black Hole Horizon

abstract:
  Motion of a particle near a horizon of a spherically symmetric black hole is
shown to possess a universal Lyapunov exponent of a chaos provided by its
surface gravity. To probe the horizon, we introduce electromagnetic or scalar
force to the particle so that it does not fall into the horizon. There appears
an unstable maximum of the total potential where the evaluated maximal Lyapunov
exponent is found to be independent of the external forces and the particle
mass. The Lyapunov exponent is universally given by the surface gravity of the
black hole. Unless there are other sources of a chaos, the Lyapunov exponent is
subject to an inequality $\lambda \leq 2\pi T_{\rm BH}/\hbar$, which is
identical to the bound recently discovered by Maldacena, Shenker and Stanford.


title: Quantum field theories on categories fibered in groupoids

abstract:
  We introduce an abstract concept of quantum field theory on categories
fibered in groupoids over the category of spacetimes. This provides us with a
general and flexible framework to study quantum field theories defined on
spacetimes with extra geometric structures such as bundles, connections and
spin structures. Using right Kan extensions, we can assign to any such theory
an ordinary quantum field theory defined on the category of spacetimes and we
shall clarify under which conditions it satisfies the axioms of locally
covariant quantum field theory. The same constructions can be performed in a
homotopy theoretic framework by using homotopy right Kan extensions, which
allows us to obtain first toy-models of homotopical quantum field theories
resembling some aspects of gauge theories.


title: Learning to Learn Neural Networks

abstract:
  Meta-learning consists in learning learning algorithms. We use a Long Short
Term Memory (LSTM) based network to learn to compute on-line updates of the
parameters of another neural network. These parameters are stored in the cell
state of the LSTM. Our framework allows to compare learned algorithms to
hand-made algorithms within the traditional train and test methodology. In an
experiment, we learn a learning algorithm for a one-hidden layer Multi-Layer
Perceptron (MLP) on non-linearly separable datasets. The learned algorithm is
able to update parameters of both layers and generalise well on similar
datasets.


title: LiFi - Let There Be Light

abstract:
  The paper proclaims a summary of Li-Fi technology. It is an efficient data
communication mechanism involving visible light as a medium of transmission.
This monograph introduces the concept of Li-Fi and its working model.
Furthermore, it discusses its benefits, shortcomings and examines ways to
mitigate the drawbacks. Additionally, it analyzes its present applications and
explores its future scope in the competitive wireless network market.


title:
Synthetic-gauge-field-induced resonances and
  Fulde-Ferrell-Larkin-Ovchinnikov states in a one-dimensional optical lattice

abstract:
  Coherent coupling generated by laser light between the hyperfine states of
atoms, loaded in a 1D optical lattice, gives rise to the "synthetic dimension"
system which is equivalent to a Hofstadter model in a finite strip of square
lattice. An SU(M) symmetric attractive interaction in conjunction with the
synthetic gauge field present in this system gives rise to unusual effects. We
study the two- body problem of the system using the T-matrix formalism. We show
that the two-body ground states pick up a finite momentum and can transform
into two-body resonance like features in the scattering continuum with a large
change in the phase shift. As a result, even for this 1D system, a critical
amount of attraction is needed to form bound states. These phenomena have
spectacular effects on the many body physics of the system analyzed using the
numerical density matrix renormalization group technique. We show that the
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states form in the system even for a
"balanced" gas and the FFLO momentum of the pairs scales linearly with flux.
Considering suitable measures, we investigate interesting properties of these
states. We also discuss a possibility of realization of a generalized
interesting topological model, called the Creutz ladder.


title: Exceptional Quantum Walk Search on the Cycle

abstract:
  Quantum walks are standard tools for searching graphs for marked vertices,
and they often yield quadratic speedups over a classical random walk's hitting
time. In some exceptional cases, however, the system only evolves by sign
flips, staying in a uniform probability distribution for all time. We prove
that the one-dimensional periodic lattice or cycle with any arrangement of
marked vertices is such an exceptional configuration. Using this discovery, we
construct a search problem where the quantum walk's random sampling yields an
arbitrary speedup in query complexity over the classical random walk's hitting
time. In this context, however, the mixing time to prepare the initial uniform
state is a more suitable comparison than the hitting time, and then the speedup
is roughly quadratic.


title: Step Heat Profile in Localized Chains

abstract:
  We consider two types of strongly disordered one-dimensional Hamiltonian
systems coupled to baths (energy or particle reservoirs) at the boundaries:
strongly disordered quantum spin chains and disordered classical harmonic
oscillators. These systems are believed to exhibit localization, implying in
particular that the conductivity decays exponentially in the chain length $L$.
We ask however for the profile of the (very slowly) transported quantity in the
steady state. We find that this profile is a step-function, jumping in the
middle of the chain from the value set by the left bath to the value set by the
right bath. The width of the step grows not faster than $\sqrt{L}$. This is
confirmed by numerics on a disordered quantum spin chain of 9 spins and on much
longer chains of harmonic oscillators. In the case of harmonic oscillators, we
also observe a drastic breakdown of local equilibrium at the step, resulting in
a chaotic temperature profile.


title: On the Security of Carrier Phase-based Ranging

abstract:
  Multicarrier phase-based ranging is fast emerging as a cost-optimized
solution for a wide variety of proximity-based applications due to its low
power requirement, low hardware complexity and compatibility with existing
standards such as ZigBee and 6LoWPAN. Given potentially critical nature of the
applications in which phase-based ranging can be deployed (e.g., access
control, asset tracking), it is important to evaluate its security guarantees.
Therefore, in this work, we investigate the security of multicarrier
phase-based ranging systems and specifically focus on distance decreasing relay
attacks that have proven detrimental to the security of proximity-based access
control systems (e.g., vehicular passive keyless entry and start systems). We
show that phase-based ranging, as well as its implementations, are vulnerable
to a variety of distance reduction attacks. We describe different attack
realizations and verify their feasibility by simulations and experiments on a
commercial ranging system. Specifically, we successfully reduced the estimated
range to less than 3 m even though the devices were more than 50 m apart. We
discuss possible countermeasures against such attacks and illustrate their
limitations, therefore demonstrating that phase-based ranging cannot be fully
secured against distance decreasing attacks.


title:
Boundary Causality vs Hyperbolicity for Spherical Black Holes in
  Gauss-Bonnet

abstract:
  We explore the constraints boundary causality places on the allowable
Gauss-Bonnet gravitational couplings in asymptotically AdS spaces, specifically
considering spherical black hole solutions. We additionally consider the
hyperbolicity properties of these solutions, positing that
hyperbolicity-violating solutions are sick solutions whose causality properties
provide no information about the theory they reside in. For both signs of the
Gauss-Bonnet coupling, spherical black holes violate boundary causality at
smaller absolute values of the coupling than planar black holes do. For
negative coupling, as we tune the Gauss-Bonnet coupling away from zero, both
spherical and planar black holes violate hyperbolicity before they violate
boundary causality. For positive coupling, the only hyperbolicity-respecting
spherical black holes which violate boundary causality do not do so appreciably
far from the planar bound. Consequently, eliminating hyperbolicity-violating
solutions means the bound on Gauss-Bonnet couplings from the boundary causality
of spherical black holes is no tighter than that from planar black holes.


title:
Close stellar conjunctions of alpha Centauri A and B until 2050 - An mK
  = 7.8 star may enter the Einstein ring of alpha Cen A in 2028

abstract:
  The rapid proper motion of the alpha Cen pair (3.7 arcsec/yr) and its
location close to the galactic plane on a rich stellar background combine to
make them excellent candidates for stellar conjunctions with distant stars.
Adding new astrometry to archival data, we have refined the orbital parameters,
barycentric proper motion and parallax of alpha Cen and compute its apparent
trajectory on sky over the coming decades. We present a catalog of the expected
close conjunctions until 2050. An exceptional event will take place in early
May 2028, when alpha Cen A will come within 0.015 +/- 0.135 arcseconds of the
mK = 7.8 star 2MASS 14392160-6049528 (hereafter S5). In terms of impact
parameter and contrast, this is the most favorable stellar conjunction of alpha
Cen within at least the next three decades. With an angular diameter of LD =
0.47 +/- 0.05 mas, it is likely that S5 is a red giant or supergiant located at
several kiloparsecs. The approached stars will act as moving light probes in
transmission through the environment of alpha Cen. The observation of these
close conjunctions holds great promises to search for planets and other low
mass objects in the alpha Cen system using photometry and astrometry. The
relativistic deflection of the approached star images will be in the
milliarcsecond range. The small impact parameter of the conjunction with S5
means that this star has a probability of 45% of entering the Einstein ring of
alpha Cen A. The gravitational amplification of the flux of S5 could reach a
factor five for the combination of the two lensed images. The proper motion,
orbital parameters and parallax of alpha Cen will be measurable with an extreme
accuracy from differential astrometry with the S stars. This will be valuable,
for example to prepare the Breakthrough Starshot initiative to send
interstellar nanocrafts to alpha Centauri.


title: An infinite family of strongly real Beauville $p$-groups

abstract:
  We give an infinite family of non-abelian strongly real Beauville $p$-groups
for every prime $p$ by considering the quotients of triangle groups, and indeed
we prove that there are non-abelian strongly real Beauville $p$-groups of order
$p^n$ for every $n \geq 3, 5$ or $7$ according as $p \geq 5$ or $p =3$ or $p
=2$. This shows that there are strongly real Beauville $p$-groups exactly for
the same orders for which there exist Beauville $p$-groups.


title:
Comparison of the electromagnetic responses of $^{12}$C obtained from
  the Green's function Monte Carlo and spectral function approaches

abstract:
  The electromagnetic responses of carbon obtained from the Green's function
Monte Carlo and spectral function approaches using the same dynamical input are
compared in the kinematical region corresponding to momentum transfer in the
range 300-570 MeV. The results of our analysis, aimed at pinning down the
limits of applicability of the approximations involved in the two schemes,
indicate that the factorization ansatz underlying the spectral function
formalism provides remarkably accurate results down to momentum transfer as low
as 300 MeV. On the other hand, it appears that at 570 MeV relativistic
corrections to the electromagnetic current not included in the Monte Carlo
calculations may play a significant role in the transverse channel.


title:
Communication efficient and strongly secure secret sharing schemes based
  on algebraic geometry codes

abstract:
  Secret sharing schemes with optimal and universal communication overheads
have been obtained independently by Bitar et al. and Huang et al. However,
their constructions require a finite field of size q > n, where n is the number
of shares, and do not provide strong security. In this work, we give a general
framework to construct communication efficient secret sharing schemes based on
sequences of nested linear codes, which allows to use in particular algebraic
geometry codes and allows to obtain strongly secure and communication efficient
schemes. Using this framework, we obtain: 1) schemes with universal and close
to optimal communication overheads for arbitrarily large lengths n and a fixed
finite field, 2) the first construction of schemes with universal and optimal
communication overheads and optimal strong security (for restricted lengths),
having in particular the component-wise security advantages of perfect schemes
and the security and storage efficiency of ramp schemes, and 3) schemes with
universal and close to optimal communication overheads and close to optimal
strong security defined for arbitrarily large lengths n and a fixed finite
field.


title: A novel comparison of M{\o}ller and Compton electron-beam polarimeters

abstract:
  We have performed a novel comparison between electron-beam polarimeters based
on M{\o}ller and Compton scattering. A sequence of electron-beam polarization
measurements were performed at low beam currents ($<$ 5 $\mu$A) during the
$Q_{\rm weak}$ experiment in Hall C at Jefferson Lab. These low current
measurements were bracketed by the regular high current (180 $\mu$A) operation
of the Compton polarimeter. All measurements were found to be consistent within
experimental uncertainties of 1% or less, demonstrating that electron
polarization does not depend significantly on the beam current. This result
lends confidence to the common practice of applying M{\o}ller measurements made
at low beam currents to physics experiments performed at higher beam currents.
The agreement between two polarimetry techniques based on independent physical
processes sets an important benchmark for future precision asymmetry
measurements that require sub-1% precision in polarimetry.


title: Portable Ontological Expressions in NoSQL Queries

abstract:
  A significant barrier to the portability of queries across di- verse physical
implementations of large data stores, espe- cially NoSQL data stores, is that
the queries reference the physical storage attributes, such as the table and
column names. In this paper, we describe a technique for embed- ding
ontological expressions called Address Expressions, or A-Expressions, in NoSQL
queries to improve their portability across diverse physical implementations.
We discuss an implementation of such queries over a MongoDB data store of the
Enron email corpus with examples, and conduct a preliminary performance
assessment.


title:
The survey of sentiment and opinion mining for behavior analysis of
  social media

abstract:
  Nowadays, internet has changed the world into a global village. Social Media
has reduced the gaps among the individuals. Previously communication was a time
consuming and expensive task between the people. Social Media has earned fame
because it is a cheaper and faster communication provider. Besides, social
media has allowed us to reduce the gaps of physical distance, it also generates
and preserves huge amount of data. The data are very valuable and it presents
association degree between people and their opinions. The comprehensive
analysis of the methods which are used on user behavior prediction is presented
in this paper. This comparison will provide a detailed information, pros and
cons in the domain of sentiment and opinion mining.


title:
On the Approximation of Functionals of Very Large Hermitian Matrices
  represented as Matrix Product Operators

abstract:
  We present a method to approximate functionals $\text{Tr} \, f(A)$ of very
high-dimensional hermitian matrices $A$ represented as Matrix Product Operators
(MPOs). Our method is based on a reformulation of a block Lanczos algorithm in
tensor network format. We state main properties of the method and show how to
adapt the basic Lanczos algorithm to the tensor network formalism to allow for
high-dimensional computations. Additionally, we give an analysis of the
complexity of our method and provide numerical evidence that it yields good
approximations of the entropy of density matrices represented by MPOs while
being robust against truncations.


title: Hamiltonian Analysis of an On-shell U(1) Gauge Field Theory

abstract:
  We perform the Hamiltonian analysis of an on-shell U(1) gauge field theory,
in which the action is not invariant under local U(1) transformations but
recovers the invariance when the equations of motion are imposed. We firstly
apply Dirac's method of Hamiltonian analysis. We find one first-class
constraint and two second-class constraints in the vector sector. It implies
the photons have only two polarisations, at least at the classical level,
although the standard U(1) symmetry is explicitly broken. The reduced
Hamiltonian is bounded from below and the on-shell U(1) gauge field theory is
free from ghosts at the classical level.


title: Design of a Compact Reversible Read-Only-Memory with MOS Transistors

abstract:
  Energy conservative devices are the need of the modern technology which leads
to the development of reversible logic. The synthesis of reversible logic has
become an intensely studied area as it overcomes the problem of power
dissipation associated with irreversibility. Storage device such as
Read-Only-Memory (ROM) can be realized in a reversible way with low power
dissipation. The reversibility of ROM has not been yet realized in literature
and hence, this paper presents a novel reversible ROM with its Complementary
Metal Oxide Semiconductor (CMOS) realization. On the way to present the
architecture of reversible ROM, we propose a new reversible gate named as
Nowrin Papiya (NP) gate. All the proposed circuits and gates are realized with
CMOS based pass transistor logic. Finally, an algorithm as well as several
theorems on the numbers of gates, transistors and garbage outputs have been
presented to show the optimality of the reversible ROM. Simulations using
Microwind DSCH software has been shown to verify the correctness of the
proposed design. The comparative results prove that the proposed designs are
efficient and optimized in terms of numbers of gates, transistors, garbage
outputs, quantum cost and delay.


title:
Finding Clustering Configurations to Accurately Infer Packet Structures
  from Network Data

abstract:
  Clustering is often used for reverse engineering network protocols from
captured network traces. The performance of clustering techniques is often
contingent upon the selection of various parameters, which can have a severe
impact on clustering quality. In this paper we experimentally investigate the
effect of four different parameters with respect to network traces. We also
determining the optimal parameter configuration with respect to traces from
four different network protocols. Our results indicate that the choice of
distance measure and the length of the message has the most substantial impact
on cluster accuracy. Depending on the type of protocol, the $n$-gram length can
also have a substantial impact.


title: A brief Introduction to Dispersion Relations and Analyticity

abstract:
  In these lectures we provide a basic introduction into the topic of
dispersion relation and analyticity. The properties of 2-point functions are
discussed in some detail from the viewpoint of the K\"all\'en-Lehmann and
general dispersion relations. The Weinberg sum rules figure as an application.
The analytic structure of higher point functions in perturbation theory are
analysed through the Landau equations and the Cutkosky rules.


title:
A scalable architecture for quantum computation with molecular
  nanomagnets

abstract:
  A proposal for a magnetic quantum processor that consists of individual
molecular spins coupled to superconducting coplanar resonators and transmission
lines is carefully examined. We derive a simple magnetic quantum
electrodynamics Hamiltonian to describe the underlying physics. It is shown
that these hybrid devices can perform arbitrary operations on each spin qubit
and induce tunable interactions between any pair of them. The combination of
these two operations ensures that the processor can perform universal quantum
computations. The feasibility of this proposal is critically discussed using
the results of realistic calculations, based on parameters of existing devices
and molecular qubits. These results show that the proposal is feasible,
provided that molecules with sufficiently long coherence times can be developed
and accurately integrated into specific areas of the device. This architecture
has an enormous potential for scaling up quantum computation thanks to the
microscopic nature of the individual constituents, the molecules, and the
possibility of using their internal spin degrees of freedom.


title:
A Heterogeneous Out-of-Equilibrium Nonlinear $q$-Voter Model with
  Zealotry

abstract:
  We study the dynamics of the out-of-equilibrium nonlinear q-voter model with
two types of susceptible voters and zealots, introduced in [EPL 113, 48001
(2016)]. In this model, each individual supports one of two parties and is
either a susceptible voter of type $q_1$ or $q_2$, or is an inflexible zealot.
At each time step, a $q_i$-susceptible voter ($i = 1,2$) consults a group of
$q_i$ neighbors and adopts their opinion if all group members agree, while
zealots are inflexible and never change their opinion. This model violates
detailed balance whenever $q_1 \neq q_2$ and is characterized by two distinct
regimes of low and high density of zealotry. Here, by combining analytical and
numerical methods, we investigate the non-equilibrium stationary state of the
system in terms of its probability distribution, non-vanishing currents and
unequal-time two-point correlation functions. We also study the switching times
properties of the model by exploiting an approximate mapping onto the model of
[Phys. Rev. E 92, 012803 (2015)] that satisfies the detailed balance, and also
outline some properties of the model near criticality.

categories: physics.soc-ph cond-mat.stat-mech cs.SI q-bio.PE


title: Obituary for a Flea

abstract:
  The Landsman-Reuvers proposal to solve the measurement problem from within
quantum theory is extensively analysed. In favor of proposals of this kind, it
is shown that the standard reasoning behind objections to solving the
measurement problem from within quantum theory rely on counterfactual reasoning
or mathematical idealisations. Subsequently, a list of objections/challenges to
the proposal are made. Part of these objections are equally important for all
attempts at solving the measurement problem, such as the problem of
interpreting small numbers in the density matrix, the problem of reproducing
the Born rule, the use of pure states as a tool to alleviate the
interpretational issues of quantum states, and the necessity of introducing
classical certainties which are not strictly present in quantum theory. The
additional objections that are particular to the proposal, such as the physical
interpretation/origin of the flea perturbation, the use of potentials to solve
a dynamical problem, slow collapse times, the inability to handle unequal
probabilities, and the dictatorial role of the flea perturbation, lead us to
believe that the Landsman-Reuvers proposal is lacking in both physical
grounding and theoretical promise. Finally, an overview is given of the
challenges that were encountered in this attempt to solve the measurement
problem from within quantum theory.


title: Perfect quantum state transfer using Hadamard diagonalizable graphs

abstract:
  Quantum state transfer within a quantum computer can be achieved by using a
network of qubits, and such a network can be modelled mathematically by a
graph. Here, we focus on the corresponding Laplacian matrix, and those graphs
for which the Laplacian can be diagonalized by a Hadamard matrix. We give a
simple eigenvalue characterization for when such a graph has perfect state
transfer at time $\pi /2$; this characterization allows one to choose the
correct eigenvalues to build graphs having perfect state transfer. We
characterize the graphs that are diagonalizable by the standard Hadamard
matrix, showing a direct relationship to cubelike graphs. We then give a number
of constructions producing a wide variety of new graphs that exhibit perfect
state transfer, and we consider several corollaries in the settings of both
weighted and unweighted graphs, as well as how our results relate to the notion
of pretty good state transfer. Finally, we give an optimality result, showing
that among regular graphs of degree at most $4$, the hypercube is the sparsest
Hadamard diagonalizable connected unweighted graph with perfect state transfer.


title: Privacy-preserving schemes for Ad Hoc Social Networks: A survey

abstract:
  In this paper, we review the state of the art of privacy-preserving schemes
for ad hoc social networks, including, mobile social networks (MSNs) and
vehicular social networks (VSNs). Specifically, we select and in-detail examine
thirty-three privacy preserving schemes developed for or applied in the context
of ad hoc social networks. These schemes are published between 2008 and 2016.
Based on this existing privacy preservation schemes, we survey privacy
preservation models, including location privacy, identity privacy, anonymity,
traceability, interest privacy, backward privacy, and content oriented privacy.
The recent important attacks of leaking privacy, countermeasures, and game
theoretic approaches in VSNs and MSNs are summarized in form of tables. In
addition, an overview of recommendations for further research is also provided.
With this survey, readers can have a more thorough understanding of research
trends in privacy-preserving schemes for ad hoc social networks


title:
Transfer of quadratic forms and of quaternion algebras over quadratic
  field extensions

abstract:
  A theorem of Albert-Draxl states that if a tensor product of two quaternion
division algebras $Q_1$, $Q_2$ over a field $F$ is not a division algebra, then
there exists a separable quadratic extension of $F$ that embeds as a subfield
in $Q_1$ and in $Q_2$. We establish a modified version of this result where the
tensor product of quaternion algebras is replaced by the corestriction of a
single quaternion algebra over a separable field extension. As a tool in the
proof, we show that if the transfer of a nonsingular quadratic form $\varphi$
over a quadratic extension is isotropic for a linear functional $s$ such that
$s(1)=0$, then $\varphi$ contains a nondegenerate subform defined over the base
field.


title: Scrutinizing the pion condensed phase

abstract:
  When the isospin chemical potential exceeds the pion mass, charged pions
condense in the zero-momentum state forming a superfluid. Chiral perturbation
theory provides a very powerful tool for studying this phase. However, the
formalism that is usually employed in this context does not clarify various
aspects of the condensation mechanism and makes the identification of the soft
modes problematic. We re-examine the pion condensed phase using different
approaches within the chiral perturbation theory framework. As a first step, we
perform a low-density expansion of the chiral Lagrangian valid close to the
onset of the Bose-Einstein condensation. We obtain an effective theory that can
be mapped to a Gross-Pitaevskii Lagrangian in which, remarkably, all the
coefficients depend on the isospin chemical potential. The low-density
expansion becomes unreliable deep in the pion condensed phase. For this reason,
we develop an alternative field expansion deriving a low-energy Lagrangian
analog to that of quantum magnets. By integrating out the "radial" fluctuations
we obtain a soft Lagrangian in terms of the Nambu-Goldstone bosons arising from
the breaking of the pion number symmetry. Finally, we test the robustness of
the second-order transition between the normal and the pion condensed phase
when next-to-leading-order chiral corrections are included. We determine the
range of parameters for turning the second-order phase transition into a
first-order one, finding that the currently accepted values of these
corrections are unlikely to change the order of the phase transition.


title: Leveraging Diversity and Sparsity in Blind Deconvolution

abstract:
  This paper considers recovering $L$-dimensional vectors $\boldsymbol{w}$, and
$\boldsymbol{x}_1,\boldsymbol{x}_2, \ldots, \boldsymbol{x}_N$ from their
circular convolutions $\boldsymbol{y}_n = \boldsymbol{w}*\boldsymbol{x}_n, \ n
= 1,2,3, \ldots, N$. The vector $\boldsymbol{w}$ is assumed to be $S$-sparse in
a known basis that is spread out in the Fourier domain, and each input
$\boldsymbol{x}_n$ is a member of a known $K$-dimensional random subspace.
  We prove that whenever $K + S\log^2S \lesssim L /\log^4(LN)$, the problem can
be solved effectively by using only the nuclear-norm minimization as the convex
relaxation, as long as the inputs are sufficiently diverse and obey $N \gtrsim
\log^2(LN)$. By "diverse inputs", we mean that the $\boldsymbol{x}_n$'s belong
to different, generic subspaces. To our knowledge, this is the first
theoretical result on blind deconvolution where the subspace to which
$\boldsymbol{w}$ belongs is not fixed, but needs to be determined.
  We discuss the result in the context of multipath channel estimation in
wireless communications. Both the fading coefficients, and the delays in the
channel impulse response $\boldsymbol{w}$ are unknown. The encoder codes the
$K$-dimensional message vectors randomly and then transmits coded messages
$\boldsymbol{x}_n$'s over a fixed channel one after the other. The decoder then
discovers all of the messages and the channel response when the number of
samples taken for each received message are roughly greater than
$(K+S\log^2S)\log^4(LN)$, and the number of messages is roughly at least
$\log^2(LN)$.


title: High efficiency thermal switch based on topological Josephson junctions

abstract:
  We propose theoretically a thermal switch operating by the magnetic-flux
controlled diffraction of phase-coherent heat currents in a thermally biased
Josephson junction based on a two-dimensional topological insulator. For short
junctions, the system shows a sharp switching behavior while for long junctions
the switching is smooth. Physically, the switching arises from the Doppler
shift of the superconducting condensate due to screening currents induced by a
magnetic flux. We suggest a possible experimental realization that exhibits a
relative temperature change of 40\% between the on and off state for realistic
parameters. This is a factor of two larger than in recently realized thermal
modulators based on conventional superconducting tunnel junctions.


title:
Impact of Instrument Responses on the Detectability of One-point
  Statistics from Redshifted 21 cm Observations

abstract:
  We study the impact of instrumental systematics on the variance, skewness,
and kurtosis of redshifted 21 cm intensity fluctuation observations from the
Epoch of Reionization. We simulate realistic 21 cm observations based on the
Murchison Widefield Array (MWA) Phase I reionization experiment, using the
array's point spread function (PSF) and antenna beam patterns, full-sky 21 cm
models, and the FHD imaging pipeline. We measure the observed redshift
evolution of pixel probability density functions (PDF) and one-point statistics
from the simulated maps, comparing them to the measurements derived from
simpler simulations that represent the instrument PSFs with Gaussian kernels.
We find that both methods yield statistics with similar trends with greater
than 80% correlation. We perform additional simulations based on the Hydrogen
Epoch of Reionization Array (HERA), using Gaussian kernels as the instrument
PSFs, and study the effect of frequency binning on the statistics. We find that
PSF smoothing and sampling variance from measuring the statistics over limited
field of view dilute intrinsic features and add fluctuations to the statistics
but reveal new detectable features. Observed kurtosis will increase when a few
extremely high or low temperature regions are present in the maps. Frequency
binning reduces the thermal uncertainty but can also blur regions along the
frequency dimension, resulting in kurtosis peaks that only appear in statistics
derived from maps of certain frequency bins. We further find that the kurtosis
peaks will reach their maxima when the angular resolution of the PSFs match the
size scale of the extreme regions that produce the peaks. The HERA array should
be capable of charting the evolution of the observed skewness and kurtosis of
the 21 cm fluctuations with high sensitivity while the MWA Phase I will likely
be capable of detecting the peak in variance.


title: Vacuum energy in asymptotically flat 2+1 gravity

abstract:
  We compute the vacuum energy of three-dimensional asymptotically flat space
based on a Chern-Simons formulation for the Poincare group. The equivalent
action is nothing but the Einstein-Hilbert term in the bulk plus half of the
Gibbons-Hawking term at the boundary. The derivation is based on the evaluation
of the Noether charges in the vacuum. We obtain that the vacuum energy of this
space has the same value as the one of the asymptotically flat limit of
three-dimensional anti-de Sitter space.


title:
A generalized filter regularization result for some nonlinear evolution
  equations in Hilbert spaces

abstract:
  Despite the strong focus of regularization on ill-posed problems, the general
construction of such methods has not been fully explored. Moreover, many
previous studies cannot be clearly adapted to handle more complex scenarios,
albeit the greatly increasing concerns on the improvement of wider classes. In
this note, we rigorously study a general theory for filter regularized
operators in a Hilbert space for nonlinear evolution equations which have
occurred naturally in different areas of science. The starting point lies in
problems that are in principle ill-posed with respect to the initial/final
data\textendash these basically include the Cauchy problem for nonlinear
elliptic equations and the backward-in-time nonlinear parabolic equations. We
derive general filters that can be used to stabilize those problems.
Essentially, we establish the corresponding well-posed problem whose solution
converges to the solution of the ill-posed problem. The approximation can be
confirmed by the error estimates in the Hilbert space. This work improves very
much many papers in the same line of field.


title: Hamiltonization of solids of revolution through reduction

abstract:
  In this paper we study the relation between conserved quantities of
nonholonomic systems and the hamiltonization problem employing the geometric
methods of [1,3]. We illustrate the theory with classical examples describing
the dynamics of solids of revolution rolling without sliding on a plane. In
these cases, using the existence of two conserved quantities we obtain, by
means of 'gauge transformations' and symmetry reduction, genuine Poisson
brackets describing the reduced dynamics.


title:
Greybody factor of scalar field from Reissner-Nordstrom-de Sitter black
  hole

abstract:
  In this work we derive a general expression for the greybody factor of
non-minimally coupled scalar fields in Reissner-Nordstr\"om-de Sitter spacetime
in low frequency approximation. In particular case of zero momentum, greybody
factor tends to zero in low frequency limit as frequency squared goes to zero
for non-vanishing coupling. We also elaborate the significance of the results
by giving formulae of differential energy rate and general absorption cross
section. The greybody factor gives insight into the spectrum of Hawking
radiations.


title:
Error Bounds for Control Constrained Singularly Perturbed
  Linear-Quadratic Optimal Control Problems

abstract:
  We present a methodology for bounding the error term of an asymptotic
solution to a singularly perturbed optimal control (SPOC) problem whose exact
solution is known to be computationally intractable. In previous works, reduced
or computationally tractable problems that are no longer dependent on the
singular perturbation parameter $\epsilon$, where $\epsilon$ represents a
small, non-negative number, have provided asymptotic error bounds of the form
$O(\epsilon)$. Specifically, the optimal solution $\bar{V}$ of the reduced
problem has been shown to be asymptotically equivalent in $\epsilon$ to the
optimal solution $V(\epsilon)$ of the singularly perturbed problem in the sense
that $|V(\epsilon)-\bar{V}| =O(\epsilon)$ as $\epsilon \rightarrow 0$. In this
paper, we improve on this result by incorporating a duality theory into the
SPOC problem and derive an upper bound $\chi_u(\epsilon)$ and lower bound
$\chi_l(\epsilon)$ of $V(\epsilon)$ that hold for arbitrary $\epsilon$ and,
furthermore, satisfy the inequality $|\chi_u(\epsilon)-\chi_l(\epsilon)| \leq C
\epsilon$ for small $\epsilon$, with the constant $C$ determined. We carry out
numerical experiments to illustrate the computational savings obtained for the
upper and lower bound. In particular, we generate a set of 50 random SPOC
problems of a specific form and show that for $\epsilon$ smaller than
$10^{-2}$, it becomes faster, on average, to solve for the bounds rather than
the SPOC problem and for $\epsilon=10^{-5}$, the computational time for the
upper and lower bounds is approximately 20 times faster, on average, than that
of the SPOC problem.


title:
Efficiency of active learning for the allocation of workers on
  crowdsourced classification tasks

abstract:
  Crowdsourcing has been successfully employed in the past as an effective and
cheap way to execute classification tasks and has therefore attracted the
attention of the research community. However, we still lack a theoretical
understanding of how to collect the labels from the crowd in an optimal way. In
this paper we focus on the problem of worker allocation and compare two active
learning policies proposed in the empirical literature with a uniform
allocation of the available budget. To this end we make a thorough mathematical
analysis of the problem and derive a new bound on the performance of the
system. Furthermore we run extensive simulations in a more realistic scenario
and show that our theoretical results hold in practice.


title: Prediction error after model search

abstract:
  Estimation of the prediction error of a linear estimation rule is difficult
if the data analyst also use data to select a set of variables and construct
the estimation rule using only the selected variables. In this work, we propose
an asymptotically unbiased estimator for the prediction error after model
search. Under some additional mild assumptions, we show that our estimator
converges to the true prediction error in $L^2$ at the rate of $O(n^{-1/2})$,
with $n$ being the number of data points. Our estimator applies to general
selection procedures, not requiring analytical forms for the selection. The
number of variables to select from can grow as an exponential factor of $n$,
allowing applications in high-dimensional data. It also allows model
misspecifications, not requiring linear underlying models. One application of
our method is that it provides an estimator for the degrees of freedom for many
discontinuous estimation rules like best subset selection or relaxed Lasso.
Connection to Stein's Unbiased Risk Estimator is discussed. We consider
in-sample prediction errors in this work, with some extension to out-of-sample
errors in low dimensional, linear models. Examples such as best subset
selection and relaxed Lasso are considered in simulations, where our estimator
outperforms both $C_p$ and cross validation in various settings.


title:
Universality of the matrix Airy and Bessel functions at spectral edges
  of unitary ensembles

abstract:
  This paper deals with products and ratios of average characteristic
polynomials for unitary ensembles. We prove universality at the soft edge of
the limiting eigenvalues' density, and write the universal limit in function of
the Kontsevich matrix model ("matrix Airy function", as originally named by
Kontsevich). For the case of the hard edge, universality is already known. We
show that also in this case the universal limit can be expressed as a matrix
integral ("matrix Bessel function") known in the literature as generalized
Kontsevich matrix model.


title:
Beam-target double spin asymmetry in quasi-elastic electron scattering
  off the deuteron with CLAS

abstract:
  Quasi-elastic electron scattering on the deuteron is a benchmark reaction to
test our understanding of deuteron structure and the properties and
interactions of the two nucleons bound in the deuteron. The experimental data
presented here can be used to test state-of-the-art models of the deuteron and
the two-nucleon interaction in the final state after two-body breakup of the
deuteron. Focusing on polarization degrees of freedom, we gain information on
spin-momentum correlations in the deuteron ground state (due to the D-state
admixture) and on the limits of the Impulse Approximation (IA) picture as it
applies to measurements of spin-dependent observables like spin structure
functions for bound nucleons. We measured the beam-target double spin asymmetry
for quasi-elastic electron scattering off the deuteron at several beam energies
using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson
National Accelerator Facility. The deuterons were polarized along (or opposite
to) the beam direction. The double spin asymmetries were measured as a function
of photon virtuality , missing momentum, and the angle between the (inferred)
"spectator" neutron and the momentum transfer direction. The results are
compared with a recent model that includes Final State Interactions (FSI) using
a complete parameterization of nucleon-nucleon scattering, as well as a
simplified model using the Plane Wave Impulse Approximation (PWIA). We find
overall good agreement with both the PWIA and FSI expectations at low to medium
missing momenta, including the change of the asymmetry due to the contribution
of the deuteron D-state at higher momenta. At the highest missing momenta, our
data clearly agree better with the calculations including FSI.


title:
Heavy-tailed response of structural systems subjected to stochastic
  excitation containing extreme forcing events

abstract:
  We characterize the complex, heavy-tailed probability distribution functions
(pdf) describing the response and its local extrema for structural systems
subjected to random forcing that includes extreme events. Our approach is based
on the recent probabilistic decomposition-synthesis technique, where we
decouple rare events regimes from the background fluctuations. The result of
the analysis has the form of a semi-analytical approximation formula for the
pdf of the response (displacement, velocity, and acceleration) and the pdf of
the local extrema. For special limiting cases (lightly damped or heavily damped
systems) our analysis provides fully analytical approximations. We also
demonstrate how the method can be applied to high dimensional structural
systems through a two-degrees-of-freedom structural system undergoing rare
events due to intermittent forcing. The derived formulas can be evaluated with
very small computational cost and are shown to accurately capture the
complicated heavy-tailed and asymmetrical features in the probability
distribution many standard deviations away from the mean, through comparisons
with expensive Monte-Carlo simulations.


title:
Limit holomorphic sections and Donaldson's construction of symplectic
  submanifolds

abstract:
  In this note, we reformulate Donaldson's construction as a compactness
result. Approximately holomorphic sections accumulate to "limit holomorphic
sections" and uniform transversality properties of the approximately
holomorphic sections correspond to transversality properties of their limits.


title:
Entropy production in field theories without time reversal symmetry:
  Quantifying the non-equilibrium character of active matter

abstract:
  Active matter systems operate far from equilibrium due to the continuous
energy injection at the scale of constituent particles. At larger scales,
described by coarse-grained models, the global entropy production rate S
quantifies the probability ratio of forward and reversed dynamics and hence the
importance of irreversibility at such scales: it vanishes whenever the
coarse-grained dynamics of the active system reduces to that of an effective
equilibrium model. We evaluate S for a class of scalar stochastic field
theories describing the coarse-grained density of self-propelled particles
without alignment interactions, capturing such key phenomena as
motility-induced phase separation. We show how the entropy production can be
decomposed locally (in real space) or spectrally (in Fourier space), allowing
detailed examination of the spatial structure and correlations that underly
departures from equilibrium. For phase-separated systems, the local entropy
production is concentrated mainly on interfaces with a bulk contribution that
tends to zero in the weak-noise limit. In homogeneous states, we find a
generalized Harada-Sasa relation that directly expresses the entropy production
in terms of the wavevector-dependent deviation from the fluctuation-dissipation
relation between response functions and correlators. We discuss extensions to
the case where the particle density is coupled to a momentum-conserving
solvent, and to situations where the particle current, rather than the density,
should be chosen as the dynamical field. We expect the new conceptual tools
developed here to be broadly useful in the context of active matter, allowing
one to distinguish when and where activity plays an essential role in the
dynamics.


title:
Convergence of the Critical Planar Ising Interfaces to Hypergeometric
  SLE

abstract:
  We consider the planar Ising model in rectangle $(\Omega; x^L, x^R, y^R,
y^L)$ with alternating boundary condition: $\ominus$ along $(x^Lx^R)$ and
$(y^Ry^L)$, $\xi^R\in\{\oplus, \text{free}\}$ along $(x^Ry^R)$, and
$\xi^L\in\{\oplus, \text{free}\}$ along $(y^Lx^L)$. We prove that the interface
of critical Ising model with these boundary conditions converges to the
so-called hypergeometric SLE$_3$. The method developed in this paper does not
require constructing new holomorphic observable and the input is the
convergence of the interface with Dobrushin boundary condition. This method
could be applied to other lattice models, for instance Loop-Erased Random Walk
and level lines of discrete Gaussian Free Field.


title: Strongly maximal intersection-complete neural codes on grids are convex

abstract:
  The brain encodes spacial structure through a combinatorial code of neural
activity. Experiments suggest such codes correspond to convex areas of the
subject's environment. We present an intrinsic condition that implies a neural
code may correspond to a convex space and give a bound on the minimal dimension
underlying such a realization.


title: The bounded derived categories of an algebra with radical squared zero

abstract:
  Let $\La$ be an elementary locally bounded linear category over a field with
radical squared zero. We shall show that the bounded derived category
$D^b(\ModbLa)$ of finitely supported left $\La$-modules admits a Galois
covering which is the bounded derived category of almost finitely co-presented
representations of a gradable quiver. Restricting to the bounded derived
category $D^b({\rm mod}^b\hspace{-2pt}\La)$ of finite dimensional left
$\La$-modules, we shall be able to describe its indecomposable objects, obtain
a complete description of the shapes of its Auslander-Reiten components, and
classify those $\La$ such that $D^b({\rm mod}^b\hspace{-2.3pt}\La)$ has only
finitely many Auslander-Reiten components.


title:
On extracting sediment transport information from measurements of
  luminescence in river sediment

abstract:
  Accurately quantifying sediment transport rates in rivers remains an
important goal for geomorphologists, hydraulic engineers, and environmental
scientists. However, current techniques for measuring transport rates are
laborious, and formulae to predict transport are notoriously inaccurate. Here,
we attempt to estimate sediment transport rates using luminescence, a property
of common sedimentary minerals that is used by the geoscience community for
geochronology. This method is advantageous because of the ease of measurement
on ubiquitous quartz and feldspar sand. We develop a model based on
conservation of energy and sediment mass to explain the patterns of
luminescence in river channel sediment from a first-principles perspective. We
show that the model can accurately reproduce the luminescence observed in
previously published field measurements from two rivers with very different
sediment transport styles. The parameters from the model can then be used to
estimate the time-averaged virtual velocity, characteristic transport
lengthscales, storage timescales, and floodplain exchange rates of fine
sand-sized sediment in a fluvial system. The values obtained from the
luminescence method appear to fall within expected ranges based on published
compilations. However, caution is warranted when applying the model as the
complex nature of sediment transport can sometimes invalidate underlying
simplifications.


title: Gossamer bulk high-temperature superconductivity in FeSe

abstract:
  The cuprates and iron-based high-temperature superconductors share many
common features: layered strongly anisotropic crystal structure, strong
electronic correlations, interplay between different types of electronic
ordering, the intrinsic spatial inhomogeneity due to doping. The understanding
of complex interplay between these factors is crucial for a directed search of
new high-temperature superconductors. Here we show the appearance of
inhomogeneous gossamer superconductivity in bulk FeSe compound at ambient
pressure and at temperature 5 times higher than its zero-resistance $T_c$. This
discovery helps to understand numerous remarkable superconducting properties of
FeSe. We also find and prove a general property: if inhomogeneous
superconductivity in a anisotropic conductor first appears in the form of
isolated superconducting islands, it reduces electric resistivity
anisotropically with maximal effect along the least conducting axis. This gives
a simple and very general tool to detect inhomogeneous superconductivity in
anisotropic compounds, which is critically important to study the onset of
high-temperature superconductivity.


title: Some examples of extremal triples of commuting contractions

abstract:
  The collection $\frk{C}_3$ of all triples of commuting contractions forms a
family in the sense of Agler, and so has an "optimal" model $\pd\frk{C}_3$
generated by its extremal elements. A given $T\in\frk{C}_3$ is extremal if
every $X\in\frk{C}_3$ extending $T$ is an extension by direct sum. We show that
many of the known examples of triples in $\frk{C}_3$ that fail to have
coisometric extensions are in fact extremal.


title:
Dynamics of ternary Cu-Fe-S2 nanoparticles stabilized by organic ligands
  as seen by M\"ossbauer spectroscopy

abstract:
  Transmission M\"ossbauer spectra for 14.41-keV transition in 57Fe were
obtained for chalcopyrite-type (Cu-Fe-S2) ternary nanocrystals stabilized by
long aliphatic chain ligands. These systems could be considered as isolated
hard nano-objects dispersed in soft network of organic ligands. The main
attention was paid to the behavior of the particles whose average size was
varied in a controllable manner from 3 to 20 nm. It was found that the magnetic
hyperfine interaction was relaxed to null to the temperatures well below liquid
nitrogen temperature due to the isolation of particles. The fast dynamics could
be described by two level environment. Deeper level (atomic) was practically
the same as for bulk material except Debye temperature, but the higher level
(particle motion) was described by the classical harmonic oscillator with the
spring constant dramatically softening with increasing temperature. Such
behavior led to fast decrease of the recoilless fraction with increasing
temperature. Practically no spectra could be obtained above 240 K. The second
order Doppler shift (SOD) had additional contribution at elevated temperatures
due to the induced internal oscillations within particle by surrounding thermal
bath. Slow dynamics was characterized by the thermally driven overdamped
harmonic oscillator motions. In addition, the long range like diffusion of
particles was seen. No significant rotation of particles was found within
accessible temperature range.


title: Mean values of the Barnes double zeta-function

abstract:
  In the study of order estimation of the Riemann zeta-function $ \zeta(s) =
\sum_{n=1}^\infty n^{-s} $, solving Lindel\"{o}f hypothesis is an important
theme. As one of the relationships, asymptotic behavior of mean values has been
studied. Furthermore, the theory of the mean values is also noted in the double
zeta-functions, and the mean values of the Euler-Zagier type of double
zeta-function and Mordell-Tornheim type of double zeta-function were studied.
In this paper, we prove asymptotic formulas for mean square values of the
Barnes double zeta-function $ \zeta_2 (s, \alpha ; v, w ) = \sum_{m=0}^\infty
\sum_{n=0}^\infty (\alpha+vm+wn)^{-s} $ with respect to $ \mathrm{Im}(s) $ as $
\mathrm{Im}(s) \rightarrow + \infty $.


title:
Radiative contribution to the effective potential in a composite Higgs
  model

abstract:
  The SU(4) gauge theory with two flavors of Dirac fermions in the sextet
representation shares features of a candidate for a composite Higgs model. The
analogue of the Higgs multiplet of the Standard Model lives in the Goldstone
manifold resulting from spontaneous breaking of the global symmetry SU(4) to
SO(4). The Higgs potential arises from interaction with the particles of the
Standard Model. We have computed the gauge boson contribution to the Higgs
potential, using valence overlap fermions on a Wilson-clover sea. The
calculation is similar to that of the electromagnetic mass splitting of the
pion multiplet in QCD.