title: Sampling-based Decentralized Monitoring for Networked Embedded Systems

abstract:
  Decentralized monitoring (DM) refers to a monitoring technique, where each
component must infer, based on a set of partial observations if the global
property is satisfied. Our work is inspired by the theoretical results
presented by Baurer and Falcone at FM 2012, where the authors introduced an
algorithm for distributing and monitoring LTL formulae, such that satisfaction
or violation of specifications can be detected by local monitors alone.
However, their work is based on the main assumption that neither the
computation nor communication take time, hence it does not take into account
how to set a sampling time among the components such that their local traces
are consistent. In this work we provide a timed model in UPPAAL and we show a
case study on a networked embedded systems board.


title: A stochastic hybrid model of a biological filter

abstract:
  We present a hybrid model of a biological filter, a genetic circuit which
removes fast fluctuations in the cell's internal representation of the extra
cellular environment. The model takes the classic feed-forward loop (FFL) motif
and represents it as a network of continuous protein concentrations and binary,
unobserved gene promoter states. We address the problem of statistical
inference and parameter learning for this class of models from partial,
discrete time observations. We show that the hybrid representation leads to an
efficient algorithm for approximate statistical inference in this circuit, and
show its effectiveness on a simulated data set.


title: A Simple Stochastic Differential Equation with Discontinuous Drift

abstract:
  In this paper we study solutions to stochastic differential equations (SDEs)
with discontinuous drift. We apply two approaches: The Euler-Maruyama method
and the Fokker-Planck equation and show that a candidate density function based
on the Euler-Maruyama method approximates a candidate density function based on
the stationary Fokker-Planck equation. Furthermore, we introduce a smooth
function which approximates the discontinuous drift and apply the
Euler-Maruyama method and the Fokker-Planck equation with this input. The point
of departure for this work is a particular SDE with discontinuous drift.


title: On sums of graph eigenvalues

abstract:
  We use two variational techniques to prove upper bounds for sums of the
lowest several eigenvalues of matrices associated with finite, simple,
combinatorial graphs. These include estimates for the adjacency matrix of a
graph and for both the standard combinatorial Laplacian and the renormalized
Laplacian. We also provide upper bounds for sums of squares of eigenvalues of
these three matrices.
  Among our results, we generalize an inequality of Fiedler for the extreme
eigenvalues of the graph Laplacian to a bound on the sums of the smallest (or
largest) k such eigenvalues, k < n.
  Furthermore, if lambda_j are the eigenvalues of the positive graph Laplacian
H, in increasing order, on a finite graph with |V| vertices and |E| edges which
is isomorphic to a subgraph of the \nu-dimensional infinite cubic lattice, then
the spectral sums obey a Weyl-type upper bound, a simplification of which reads
  $$ \sum_{j=1}^{k-1}{\lambda_j} \le \frac{\pi^2 |\mathcal{E}|}{3}
\left(\frac{k}{|\mathcal{V}|} \right)^{1+\frac{2}{\nu}} $$ for each k < |V|.
  This and related estimates for sums of lambda_j^2 provide a family of
necessary conditions for the embeddability of the graph in a lattice of
dimension \nu or less.


title:
In-in and $\delta N$ calculations of the bispectrum from non-attractor
  single-field inflation

abstract:
  In non-attractor single-field inflation models producing a scale-invariant
power spectrum, the curvature perturbation on super-horizon scales grows as
${\cal R}\propto a^3$. This is so far the only known class of self-consistent
single-field models with a Bunch-Davies initial state that can produce a large
squeezed-limit bispectrum violating Maldacena's consistency relation. Given the
importance of this result, we calculate the bispectrum with three different
methods: using quantum field theory calculations in two different gauges, and
classical calculations (the $\delta N$ formalism). All the results agree,
giving the local-form bispectrum parameter of
$f^{local}_{NL}=5(1+c_s^2)/(4c_s^2)$. This result is valid for arbitrary values
of the speed of sound parameter, $c_s$, for a particular non-attractor model we
consider in this paper.


title:
Target capture and massively parallel sequencing of ultraconserved
  elements (UCEs) for comparative studies at shallow evolutionary time scales

abstract:
  Comparative genetic studies of non-model organisms are transforming rapidly
due to major advances in sequencing technology. A limiting factor in these
studies has been the identification and screening of orthologous loci across an
evolutionarily distant set of taxa. Here, we evaluate the efficacy of genomic
markers targeting ultraconserved DNA elements (UCEs) for analyses at shallow
evolutionary timescales. Using sequence capture and massively parallel
sequencing to generate UCE data for five co-distributed Neotropical rainforest
bird species, we recovered 776-1,516 UCE loci across the five species. Across
species, 53-77 percent of the loci were polymorphic, containing between 2.0 and
3.2 variable sites per polymorphic locus, on average. We performed species tree
construction, coalescent modeling, and species delimitation, and we found that
the five co-distributed species exhibited discordant phylogeographic histories.
We also found that species trees and divergence times estimated from UCEs were
similar to those obtained from mtDNA. The species that inhabit the understory
had older divergence times across barriers, contained a higher number of
cryptic species, and exhibited larger effective population sizes relative to
species inhabiting the canopy. Because orthologous UCEs can be obtained from a
wide array of taxa, are polymorphic at shallow evolutionary time scales, and
can be generated rapidly at low cost, they are effective genetic markers for
studies investigating evolutionary patterns and processes at shallow time
scales.


title: A Novel Extension of Randomly Weighted Average

abstract:
  We study a well-known problem concerning a random variable $Z$ uniformly
distributed between two independent random variables. A new extension has been
introduced for this problem and fairly large classes of randomly weighted
average distributions are identified by their generalized Stieltjes transforms.
In this article we employ the Schwartz distribution theory for finding
distributions of this extension; we also study some of their properties.


title: The Gribov phenomenon in flat and curved spaces

abstract:
  The quantization of Yang-Mills theories relies on the gauge-fixing procedure.
However, in the non-Abelian case this procedure leads to the well known Gribov
ambiguity. In order to solve the ambiguity a modification of the functional
integral formula must be introduced. As a consequence of this, the Green
functions get deep modifications in the infrared. We consider in particular the
SU (N) case and show that in the pure gauge case the ghost propagator is
enhanced, while the gluon propagator is suppressed in this limit, therefore the
study of the Gribov ambiguity may shed some light on the mass gap problem and
on colour confinement. We discuss some recent developments on the subject in
the case of a curved background. We argue that the concurrent presence of a
spacetime curvature and the Gribov ambiguity may introduce further
modifications to the Green functions in the infrared.


title: Universal Scaling of Quantum Anomalous Hall Plateau Transition

abstract:
  We study the critical properties of the quantum anomalous Hall (QAH) plateau
transition in magnetic topological insulators. We introduce a microscopic model
for the plateau transition in QAH effect at the coercive field and then map it
to the network model of quantum percolation in the integer quantum Hall effect
plateau transition. Generally, an intermediate plateau with zero Hall
conductance could occur at the coercive field. $\sigma_{xx}$ would have double
peaks at the coercivity while $\rho_{xx}$ only has single peak. Remarkably,
this theoretical prediction is already borne out in experiment. Universal
scaling of the transport coefficients $\rho_{xy}$ and $\rho_{xx}$ are
predicted.


title: Singlet Dark Matter in Type II Two Higgs Doublet Model

abstract:
  Inspired by the dark matter searches in the low mass region, we study the
Type II two Higgs doublet model with a light gauge singlet WIMP stabilized by a
Z_2 symmetry. The real singlet is required to only couple to the non-Standard
Model Higgs. We investigate singlet candidates with different spins as well as
isospin violating effect. The parameter space favored by LHC data in two Higgs
doublet model and hadronic uncertainties in WIMP-nucleon elastic scattering are
also taken into account. We find only the scalar singlet in the isospin
conserving case leads to a major overlap with the region of interests of most
direct detection experiments.


title:
Beyond the Standard Model: LHC Phenomenology, Cosmology from
  Post-Inflationary Sources, and Dark Matter Physics

abstract:
  It is the goal of this dissertation to demonstrate that beyond the standard
model, certain theories exist which solve conflicts between observation and
theory -- conflicts such as massive neutrinos, dark matter, unstable Higgs
vacuum, and recent Planck observations of excess relativistic degrees of
freedom in the early universe. Theories explored include a D-brane inspired
construct of U(3) X Sp(1) X U(1) X U(1) extension of the standard model, in
which we demonstrate several possible observables that may be detected at the
LHC, and an ability to stabilize the Higgs mechanism. The extended model can
also explain recent Planck data which, when added to HST data gives an excess
of relativistic degrees of freedom of \Delta N = 0.574 +- 0.25 above the
standard result. Also explored is a possible non-thermal dark matter model for
explanation of this result. Recent observations of Fermi bubble results
indicate a signal of a 50 GeV dark matter particle annihilating into b b-bar,
with a thermally averaged annihilation cross section corresponding to < \sigma
v> = 8 X 10^(-27) cm^3/s, spurs interest in a Higgs portal model suggested by
Steven Weinberg. Other implications of this model are also explored such as its
ability to explain dark matter direct detection results along with LHC Higgs
data, and Planck data. Particle physics is complimented by possible stochastic
gravitational wave searches for which a model of second order global phase
transitions is explored. These transitions generate gravitational wave spectra
with amplitudes of order \Omega_{gw} h^2 = 10^(-24) - 10^(-15). Furthermore,
techniques into such calculations are investigated in hopes to improve the
stability required in such lattice simulations.


title: Composition of Dyadic Paraproducts

abstract:
  We obtain necessary and sufficient conditions to characterize the boundedness
of the composition of dyadic paraproduct operators.


title: The Linear Bound for the Natural Weighted Resolution of the Haar Shift

abstract:
  The Hilbert transform has a linear bound in the $A_{2}$ characteristic on
weighted $L^{2}$, \begin{equation*} \left\Vert H\right\Vert
_{L^{2}(w)\rightarrow L^{2}(w)}\lesssim \left[ w \right] _{A_{2}},
\end{equation*} and we extend this linear bound to the nine constituent
operators in the natural weighted resolution of the conjugation
$M_{w^{\frac{1}{2}}}\mathcal{S }M_{w^{-\frac{1}{2}}}$ induced by the canonical
decomposition of a multiplier into paraproducts:% \begin{equation*}
M_{f}=P_{f}^{-}+P_{f}^{0}+P_{f}^{+}. \end{equation*} The main tools used are
composition of paraproducts, a product formula for Haar coefficients, the
Carleson Embedding Theorem, and the linear bound for the square function.


title: Effect of solute segregation on shear-induced grain boundary motion

abstract:
  Atomic-scale simulations are performed to study the effect of solute
segregation on the shear-induced motion of select grain boundaries in the
classical $\alpha$-Fe/C system. At shear rates larger than the solute diffusion
rate, we observe a transition from coupled motion to sliding. Below a critical
solute excess, the boundaries break away from the solute cloud and move in a
coupled motion. At smaller shear rates, we observe extrinsic coupled motion at
small stresses indicating that the coupling is aided by convective solute
diffusion along the boundary. Our studies underscore the role of solutes in
modifying the bicrystallography, temperature and rate dependence of shear
accommodation at grain boundaries.


title:
Fast solution of boundary integral equations with the generalized
  Neumann kernel

abstract:
  A fast method for solving boundary integral equations with the generalized
Neumann kernel and the adjoint generalized Neumann kernel is presented. The
method is based on discretizing the integral equations by the Nystr\"om method
with the trapezoidal rule to obtain $(m+1)n\times(m+1)n$ linear systems where
$m+1$ is the multiplicity of the multiply connected domain and $n$ is the
number of nodes in the discretization of each boundary component. The obtained
linear systems are solved by the generalized minimal residual (GMRES) method.
Each iteration of the GMRES method requires a matrix-vector product which can
be computed using the Fast Multipole Method (FMM). The complexity of the
presented method is $O((m+1)n\ln n)$ for the integral equation with the
generalized Neumann kernel and $O((m+1)n)$ for the integral equation with the
adjoint generalized Neumann kernel. The presented numerical results illustrate
that the presented method gives accurate results even for domains with high
connectivity, domains with piecewise smooth boundaries, and domains with close
boundaries.


title: A Short Proof of Gowers' Lower Bound for the Regularity Lemma

abstract:
  A celebrated result of Gowers states that for every \epsilon > 0 there is a
graph G so that every \epsilon-regular partition of G (in the sense of
Szemeredi's regularity lemma) has order given by a tower of exponents of height
polynomial in 1/\epsilon. In this note we give a new proof of this result that
uses a construction and proof of correctness that are significantly simpler and
shorter.


title:
A Critical Assessment of Photometric Redshift Methods: A CANDELS
  Investigation

abstract:
  We present results from the Cosmic Assembly Near-infrared Deep Extragalactic
Legacy Survey (CANDELS) photometric redshift methods investigation. In this
investigation, the results from eleven participants, each using a different
combination of photometric redshift code, template spectral energy
distributions (SEDs) and priors, are used to examine the properties of
photometric redshifts applied to deep fields with broad-band multi-wavelength
coverage. The photometry used includes U-band through mid-infrared filters and
was derived using the TFIT method. Comparing the results, we find that there is
no particular code or set of template SEDs that results in significantly better
photometric redshifts compared to others. However, we find codes producing the
lowest scatter and outlier fraction utilize a training sample to optimize
photometric redshifts by adding zero-point offsets, template adjusting or
adding extra smoothing errors. These results therefore stress the importance of
the training procedure. We find a strong dependence of the photometric redshift
accuracy on the signal-to-noise ratio of the photometry. On the other hand, we
find a weak dependence of the photometric redshift scatter with redshift and
galaxy color. We find that most photometric redshift codes quote redshift
errors (e.g., 68% confidence intervals) that are too small compared to that
expected from the spectroscopic control sample. We find that all codes show a
statistically significant bias in the photometric redshifts. However, the bias
is in all cases smaller than the scatter, the latter therefore dominates the
errors. Finally, we find that combining results from multiple codes
significantly decreases the photometric redshift scatter and outlier fraction.
We discuss different ways of combining data to produce accurate photometric
redshifts and error estimates.


title:
Convex Optimization Approaches for Blind Sensor Calibration using
  Sparsity

abstract:
  We investigate a compressive sensing framework in which the sensors introduce
a distortion to the measurements in the form of unknown gains. We focus on
blind calibration, using measures performed on multiple unknown (but sparse)
signals and formulate the joint recovery of the gains and the sparse signals as
a convex optimization problem. We divide this problem in 3 subproblems with
different conditions on the gains, specifially (i) gains with different
amplitude and the same phase, (ii) gains with the same amplitude and different
phase and (iii) gains with different amplitude and phase. In order to solve the
first case, we propose an extension to the basis pursuit optimization which can
estimate the unknown gains along with the unknown sparse signals. For the
second case, we formulate a quadratic approach that eliminates the unknown
phase shifts and retrieves the unknown sparse signals. An alternative form of
this approach is also formulated to reduce complexity and memory requirements
and provide scalability with respect to the number of input signals. Finally
for the third case, we propose a formulation that combines the earlier two
approaches to solve the problem. The performance of the proposed algorithms is
investigated extensively through numerical simulations, which demonstrates that
simultaneous signal recovery and calibration is possible with convex methods
when sufficiently many (unknown, but sparse) calibrating signals are provided.


title:
Landen transforms as families of (commuting) rational self-maps of
  projective space

abstract:
  The classical (m,k)-Landen transform F_{m,k} is a self-map of the field of
rational functions C(z) obtained by forming a weighted average of a rational
function over twists by m'th roots of unity. Identifying the set of rational
maps of degree d with an affine open subset of P^{2d+1}, we prove that F_{m,0}
induces a dominant rational self-map R_{d,m,0} of P^{2d+1} of algebraic degree
m, and for 0 < k < m, the transform F_{m,k} induces a dominant rational
self-map R_{d,m,k} of algebraic degree m of a certain hyperplane in P^{2d+1}.
We show in all cases that R_{d,m,k} extends nicely to a map of P^{2d+1} over
Spec(Z), and that {R_{d,m,0} : m \ge 0} is a commuting family of maps.


title:
Technological and Cost based Analysis of Future-Proof Fiber Access
  Passive Networks: GPON and WDM PON

abstract:
  This paper discusses the key principles of Gigabit Passive Optical Network
(GPON) which is based on Time Division Multiplexing Passive Optical Network
(TDM PON) and Wavelength Division Multiplexing Passive Optical Network (WDM
PON), which is considered to be next generation passive optical network. In the
present day scenario, access to broad- band is increasing at a rapid pace.
Because of the advantages of fiber access in terms of capacity and cost, most
of the countries have started deploying GPON access as an important part of
national strategy. Though GPON is promising, it has few limitations. On the
other hand WDM PON, a next generation network, is quite promising unlike GPON,
it is easily scalable and interoperable with different vendors. This paper
provides an overview of GPON, WDM PON and its key dissimilarities based on
technicalities and cost.


title:
Superconducting phase within the hidden-order state of the heavy-fermion
  material $\mathrm{URu_{2}Si_{2}}$

abstract:
  An unconventional pairing mechanism in the heavy-fermion material
$\mathrm{URu_{2}Si_{2}}$ is studied. We propose a mixed singlet-triplet
$d$-density wave to be the hidden-order state in $\mathrm{URu_{2}Si_{2}}$. The
exotic order is topologically nontrivial and supports a charge $2e$ skyrmionic
spin texture, which is assumed to fractionalize into merons and antimerons at
the deconfined quantum critical point. The interaction between these fractional
particles results in a (pseudo)spin-singlet chiral $d$-wave superconducting
state, which breaks time reversal symmetry. Therefore, it is highly likely to
produce a nonzero signal of the polar Kerr effect at the onset of the
superconductivity, consistent with recent experiments. In addition, the nodal
structures of the possible pairing functions in our model are consistent with
the thermodynamic experiments in $\mathrm{URu_{2}Si_{2}}$.


title:
Formation of Dominance Relationships via Strategy Updating in an
  Asymmetric Hawk-Dove Game

abstract:
  We develop a model to describe the development of dominance relations between
social animals as they use past experiences to inform future interactions.
Using the game-theoretic framework of a Hawk-Dove game with asymmetric
resource-holding potentials (RHPs), we derive a simple model that describes the
social interactions of animals that compete for resources. We then consider a
game-playing strategy in which animals acquire information about their RHP
asymmetry from the results of their previous contests and subsequently use
their asymmetry assessment to inform their behavior in future contests. We
examine how directly incorporating the fact that animals have incomplete
information in their interactions can lead to outcomes that differ from what
would be expected if one considers the situation as a static game in which the
animals have perfect information about the asymmetry size. We thereby obtain
results that are consistent with observations of dominance-hierarchy formation
in social animals. We also discuss how increased interactions between animals
can speed up the asymmetry assessment process and how this can explain why
aggression can sometimes decrease as the number of interactions between animals
increases over time.


title: Dissipative quantum metrology in manybody systems of identical particles

abstract:
  Estimation of physical parameters is a must in almost any part of science and
technology. The enhancement of the performances in this task, e.g., beating the
standard classical shot-noise limit, using available physical resources is a
major goal in metrology. Quantum metrology in closed systems has indicated that
entanglement in such systems may be a useful resource. However, it is not yet
fully understood whether in open quantum systems such enhancements may still
show up. Here, we consider a dissipative (open) quantum system of identical
particles in which a parameter of the open dynamics itself is to be estimated.
We employ a recently-developed dissipative quantum metrology framework, and
investigate whether the entanglement produced in the course of the dissipative
dynamics may help the estimation task. Specifically, we show that even in a
Markovian dynamics, in which states become less distinguishable in time, at
small enough times entanglement generated by the dynamics may offer some
advantage over the classical shot-noise limit.


title:
Adaptive Backoff Algorithm for IEEE 802.11 DCF under MPR Wireless
  Channels

abstract:
  As a result of the recent advances in physical (PHY) layer communication
techniques, it is possible to receive multiple packets at the receiver
concurrently. This capability of a receiver to decode multiple simultaneous
transmissions is known as multi-packet reception (MPR). In this paper, we
propose a simple Medium Access Control (MAC) protocol for an MPR wireless
channel, where we modify the backoff procedure as a function of number of
ongoing transmissions in the channel. Our protocol is backward compatible with
the IEEE 802.11 DCF protocol. The performance analysis of the proposed protocol
is carried out using extensive simulations and it is compared with some of the
existing MPR MAC protocols. The proposed mechanism improves the throughput and
delay performance of the IEEE 802.11 DCF.


title: The Chimaerical Quest for the Optical Plasmonic Superlens

abstract:
  This commentary aims to expose the fallacy of claiming that a plasmonic
silver film superlens is capable to image real subwavelength objects. This lens
was proposed by the Berkeley's group who, in their misleading experiment,
inappropriately regarded subwavelength apertures as the objects to be imaged
whereas the main function of these apertures was to transform free space laser
light into an evanescent field necessary for exciting the surface plasmon
resonance phenomenon in silver. In addition, the apertures also determined the
constrained effective area on the silver film where the phenomenon could occur.
We provide a fresh insightful physical explanation of how this phenomenon is
excited and what it entails. We emphasize the phenomenon's important effect of
subwavelength conversion (reduction) of the generated surface plasmons and
their associated bound enhanced evanescent fields.


title:
Modulation theory in PT-Symmetric Magnetic Metamaterial Arrays in the
  continuum limit

abstract:
  We present results on the dynamics of split-ring dimers having both gain and
loss in one dimensional nonlinear parity-time- (PT-)symmetric magnetic
metamaterials. For the longwave (continuum) limit approximation and in the
weakly nonlinear limit, we show analytic results on the existence of gap
soliton solutions and on symmetry breaking phenomenon at a critical value of
the gain/loss term.


title: The geometry of dented pentagram maps

abstract:
  We propose a new family of natural generalizations of the pentagram map from
2D to higher dimensions and prove their integrability on generic twisted and
closed polygons. In dimension $d$ there are $d-1$ such generalizations called
dented pentagram maps, and we describe their geometry, continuous limit, and
Lax representations with a spectral parameter. We prove algebraic-geometric
integrability of the dented pentagram maps in the 3D case and compare the
dimensions of invariant tori for the dented maps with those for the higher
pentagram maps constructed with the help of short diagonal hyperplanes. When
restricted to corrugated polygons, the dented pentagram maps coincide between
themselves and with the corresponding corrugated pentagram map. Finally, we
prove integrability for a variety of pentagram maps for generic and partially
corrugated polygons in higher dimensions.


title: Phenomenological Fluids from Interacting Tachyonic Scalar Fields

abstract:
  In this paper we are interested to consider mathematical ways to obtain
different phenomenological fluids from two-component Tachyonic scalar fields.
We consider interaction between components and investigate problem numerically.
Statefinder diagnostics and validity of the generalized second law of
thermodynamics performed and checked. We suppose that our Universe bounded by
Hubble horizon.


title: Increasing Herd Immunity with Influenza Revaccination

abstract:
  Seasonal influenza is a significant public health concern in the United
States and globally. While influenza vaccines are the single most effective
intervention to reduce influenza morbidity and mortality, there is considerable
debate surrounding the merits and consequences of repeated seasonal
vaccination. Here, we describe a two-season influenza epidemic contact network
model and use it to demonstrate that increasing the level of continuity in
vaccination across seasons reduces the burden on public health. We show that
revaccination reduces the influenza attack rate not only because it reduces the
overall number of susceptible individuals, but also because it better protects
highly-connected individuals, who would otherwise make a disproportionately
large contribution to influenza transmission. Our work thus contributes a
population-level perspective to debates about the merits of repeated influenza
vaccination and advocates for public health policy to incorporate individual
vaccine histories.


title:
Classification of spherical Lagrangian submanifolds in complex Euclidean
  spaces

abstract:
  An isometric immersion $f:M^n\to \tilde M^n$ from a Riemannian $n$-manifold
$M^n$ into a K\"ahler $n$-manifold $\tilde M^n$ is called {\it Lagrangian} if
the complex structure $J$ of the ambient manifold $\tilde M^n$ interchanges
each tangent space of $M^n$ with the corresponding normal space. In this paper,
we completely classify spherical Lagrangian submanifolds in complex Euclidean
spaces. Furthermore, we also provide two corresponding classification theorems
for Lagrangian submanifolds in the complex pseudo-Euclidean spaces with
arbitrary complex index.


title: Breakdown of Fast Water Transport in Graphene Oxides

abstract:
  Fast slip flow was reported for water inside the interlayer gallery between
graphene layers or carbon nanotubes. We report here that this flow rate
enhancement (over two orders) breaks down with the presence of chemical
functionalization and relaxation of the nanoconfinement in graphene oxides.
Molecular dynamics simulation results show that hydrodynamics applies in this
circumstance, even at length scales down to nanometers. However, corrections on
the slip boundary condition and viscosity of nanoconfined flow must be included
to make quantitative predictions. These results were discussed with structural
characteristics of the liquid water and hydrogen bond networks.


title:
Enhancing Graphene-derived Materials through Multimodal and
  Self-healable Interfaces

abstract:
  Recent studies have shown that graphene-derived materials not only feature
outstandingly multifunctional properties, but also act as model materials to
implant nanoscale structural engineering insights into their macroscopic
performance optimization. Functionalizing the interfaces between graphene
sheets by interlayer crosslinks has been proven to be an effective route to
tune the mechanical properties. Here we explore the graphene-derived material
with a layer-by-layer structure and multiple crosslinking mechanisms. The
effects of multimodal and self-healable crosslinks are assessed in terms of
interlayer loading transfer capability. The results show that the
brick-and-motar hierarchy and synergetic effects from different crosslinks
enable synergetic enhancement in the strength and toughness. The findings here
could shed light on the development of high-performance paper-, fiber- or
film-like macroscopic materials from monolayer nanosheets with nanoengineerable
interfaces.


title:
Analyzing Convergence and Rates of Convergence of Particle Swarm
  Optimization Algorithms Using Stochastic Approximation Methods

abstract:
  Recently, much progress has been made on particle swarm optimization (PSO). A
number of works have been devoted to analyzing the convergence of the
underlying algorithms. Nevertheless, in most cases, rather simplified
hypotheses are used. For example, it often assumes that the swarm has only one
particle. In addition, more often than not, the variables and the points of
attraction are assumed to remain constant throughout the optimization process.
In reality, such assumptions are often violated. Moreover, there are no
rigorous rates of convergence results available to date for the particle swarm,
to the best of our knowledge. In this paper, we consider a general form of PSO
algorithms, and analyze asymptotic properties of the algorithms using
stochastic approximation methods. We introduce four coefficients and rewrite
the PSO procedure as a stochastic approximation type iterative algorithm. Then
we analyze its convergence using weak convergence method. It is proved that a
suitably scaled sequence of swarms converge to the solution of an ordinary
differential equation. We also establish certain stability results. Moreover,
convergence rates are ascertained by using weak convergence method. A centered
and scaled sequence of the estimation errors is shown to have a diffusion
limit.


title:
Analytical Alignment Tolerances for Off-Plane Reflection Grating
  Spectroscopy

abstract:
  Future NASA X-ray Observatories will shed light on a variety of high-energy
astrophysical phenomena. Off-plane reflection gratings can be used to provide
high throughput and spectral resolution in the 0.3--1.5 keV band, allowing for
unprecedented diagnostics of energetic astrophysical processes. A grating
spectrometer consists of multiple aligned gratings intersecting the converging
beam of a Wolter-I telescope. Each grating will be aligned such that the
diffracted spectra overlap at the focal plane. Misalignments will degrade both
spectral resolution and effective area. In this paper we present an analytical
formulation of alignment tolerances that define grating orientations in all six
degrees of freedom. We verify our analytical results with raytrace simulations
to fully explore the alignment parameter space. We also investigate the effect
of misalignments on diffraction efficiency.


title: On subadditivity of Kodaira dimension in positive characteristic

abstract:
  We show that for a surjective, separable morphism f of smooth projective
varieties over an algebraically closed field of positive characteristic such
that $f_* \mathcal{O}_X = \mathcal{O}_Y$ subadditivity of Kodaira dimension
holds, provided the base is of general type and the Hasse-Witt matrix of the
geometric general fiber is not nilpotent.


title: Discovery of the Y1 Dwarf WISE J064723.23-623235.5

abstract:
  We present the discovery of a very cold, very low mass, nearby brown dwarf
using data from the NASA Wide-field Infrared Survey Explorer (WISE). The
object, WISE J064723.23-623235.5, has a very red WISE color of W1-W2 > 3.77 mag
and a very red Spitzer Space Telescope color of ch1-ch2 = 2.82+/-0.09 mag. In
J_MKO-ch2 color (7.58+/-0.27 mag) it is one of the two or three reddest brown
dwarfs known. Our grism spectrum from the Hubble Space Telescope (HST) confirms
it to be the seventeenth Y dwarf discovered, and its spectral type of Y1+/-0.5
makes it one of the four latest-type Y dwarfs classified. Astrometric imaging
from Spitzer and HST, combined with data from WISE, provides a preliminary
parallax of pi = 115+/-12 mas (d = 8.7+/-0.9 pc) and proper motion of mu =
387+/-25 mas/yr based on 2.5 years of monitoring. The spectrum implies a blue
J-H color, for which model atmosphere calculations suggest a relatively low
surface gravity. The best fit to these models indicates an effective
temperature of 350-400K and a mass of ~5-30 M_Jup. Kinematic analysis hints
that this object may belong to the Columba moving group, which would support an
age of ~30 Myr and thus an even lower mass of <2 M_Jup, but verification would
require a radial velocity measurement not currently possible for a J=22.7 mag
brown dwarf.


title: Five Families of Three-Weight Ternary Cyclic Codes and Their Duals

abstract:
  As a subclass of linear codes, cyclic codes have applications in consumer
electronics, data storage systems, and communication systems as they have
efficient encoding and decoding algorithms. In this paper, five families of
three-weight ternary cyclic codes whose duals have two zeros are presented. The
weight distributions of the five families of cyclic codes are settled. The
duals of two families of the cyclic codes are optimal.


title: Dynamic Reasoning Systems

abstract:
  A {\it dynamic reasoning system} (DRS) is an adaptation of a conventional
formal logical system that explicitly portrays reasoning as a temporal
activity, with each extralogical input to the system and each inference rule
application being viewed as occurring at a distinct time step. Every DRS
incorporates some well-defined logic together with a controller that serves to
guide the reasoning process in response to user inputs. Logics are generic,
whereas controllers are application-specific. Every controller does,
nonetheless, provide an algorithm for nonmonotonic belief revision. The general
notion of a DRS comprises a framework within which one can formulate the logic
and algorithms for a given application and prove that the algorithms are
correct, i.e., that they serve to (i) derive all salient information and (ii)
preserve the consistency of the belief set. This paper illustrates the idea
with ordinary first-order predicate calculus, suitably modified for the present
purpose, and two examples. The latter example revisits some classic
nonmonotonic reasoning puzzles (Opus the Penguin, Nixon Diamond) and shows how
these can be resolved in the context of a DRS, using an expanded version of
first-order logic that incorporates typed predicate symbols. All concepts are
rigorously defined and effectively computable, thereby providing the foundation
for a future software implementation.


title:
Exclusive charmonium production from $e^+ e^-$ annihilation round the
  $Z^0$ peak

abstract:
  We make a comparative and comprehensive study on the charmonium exclusive
productions at the $e^+e^-$ collider with the collision energy either round the
$Z^0$-boson mass for a super $Z$ factory or equals to 10.6 GeV for the $B$
factories as Belle and BABAR. We study the total cross sections for the
charmonium production via the exclusive processes $e^+e^- \to \gamma^*/Z^0 \to
H_{1}+H_{2}$ and $e^+e^- \to \gamma^*/Z^0 \to H_{1} +\gamma$, where $H_{1}$ and
$H_{2}$ represent the dominant color-singlet $S$-wave and $P$-wave charmonium
states respectively. Total cross sections versus the $e^+e^-$ collision energy
$\sqrt{s}$, together with their uncertainties, are presented, which clearly
show the relative importance of these channels. At the $B$ factory, the
production channels via the virtual $\gamma^*$ propagator are dominant over the
channels via the $Z^0$ propagator by about four orders. While, at the super $Z$
factory, due to the $Z^0$-boson resonance effect, the $Z^0$ boson channels
shall provide sizable or even dominant contributions in comparison to the
channels via the $\gamma^*$ propagator. Sizable exclusive charmonium events can
be produced at the super $Z$ factory with high luminocity up to $10^{36}{\rm
cm}^{-2}{\rm s}^{-1}$, especially for the channel of $e^+e^- \to Z^0 \to H_{1}
+\gamma$, e.g. by taking $m_c=1.50\pm0.20$ GeV, we shall have
$(5.0^{+0.8}_{-0.6})\times10^4$ $J/\psi$, $(7.5^{+1.1}_{-0.9})\times10^3$
$\eta_c$, $(6.2^{+3.3}_{-1.9})\times10^3$ $h_{c}$,
$(3.1^{+1.7}_{-0.9})\times10^2$ $\chi_{c0}$, $(2.2^{+1.0}_{-0.4})\times10^3$
$\chi_{c1}$, and $(7.7^{+4.1}_{-2.4})\times10^2$ $\chi_{c2}$ events by one
operation year. Thus, in addition to the $B$ factories as BABAR and Belle, such
a super $Z$ factory shall provide another useful platform for studying the
heavy quarkonium properties and for testing QCD theories.


title: Energy, entropy, and arbitrage

abstract:
  We introduce a pathwise approach to analyze the relative performance of an
equity portfolio with respect to a benchmark market portfolio. In this
energy-entropy framework, the relative performance is decomposed into three
components: a volatility term, a relative entropy term measuring the distance
between the portfolio weights and the market capital distribution, and another
entropy term that can be controlled by the investor by adopting a suitable
rebalancing strategy. This framework leads to a class of portfolio strategies
that allows one to outperform, in the long run, a market that is diverse and
sufficiently volatile in the sense of stochastic portfolio theory. The
framework is illustrated with several empirical examples.


title: MSSM with $m_{h}=125$ GeV in High-Scale Gauge Mediation

abstract:
  After the discovery of SM-like Higgs with $m_{h}=125$ GeV, it is increasingly
urgent to explore a solution to the hierarchy problem. In the context of MSSM
from gauge-mediated SUSY breaking, the lower bound on gluino mass suggests that
the messenger scale $M$ is probably large if the magnitude of $\Lambda\sim 100$
TeV. In this paper, we study $\overline{\mathbf{5}}+ \mathbf{5}$ model with
$M\sim 10^{8}-10^{12}$ GeV and $\Lambda\simeq 100$ TeV. For moderate
Higgs-messenger coupling, it will be shown a viable model with moderate fine
tuning. In this model, $\mu\sim 800$ GeV and $B_{\mu}$ nearly vanishes at input
scale, which can be constructed in microscopic model.


title:
Star Clusters and Dark Matter as Probes of the Spacetime Geometry of
  Massive Black Holes

abstract:
  This thesis includes two main projects. In the first part, we assess the
feasibility of a recently suggested strong-field general relativity test, in
which future observations of a hypothetical class of stars orbiting very close
to the supermassive black hole at the center of our galaxy, known as Sgr A*,
could provide tests of the so-called no-hair theorem of general relativity
through the measurement of precessions of their orbital planes. By considering
how a distribution of stars and stellar mass black holes in the central cluster
would perturb the orbits of those hypothetical stars, we show that for stars
within about 0.2 milliparsecs (about 6 light-hours) of the black hole, the
relativistic precessions dominate, leaving a potential window for tests of
no-hair theorems. Our results are in agreement with N-body simulation results.
  In the second part, we develop a fully general relativistic phase-space
formulation to consider the effects of the Galactic center supermassive black
hole Sgr A* on the dark-matter density profile and its applications in the
indirect detection of dark matter. We find significant differences from the
non-relativistic result of Gondolo and Silk (1999), including a higher density
for the spike and a larger degree of central concentration. Having the dark
matter profile density in the presence of the massive black hole, we calculate
its perturbing effect on the orbital motions of stars in the Galactic center,
and find that for the stars of interest, relativistic effects related to the
hair on the black hole will dominate the effects of dark matter.


title: Scalar Quarks at the Large Hadron Collider

abstract:
  The properties of scalar quarks are studied, especially the formation of
fermionic mesons with an anti-quark. On the basis of this theoretical
investigation together with the experimental data, both from last year and from
this year, of the ATLAS Collaboration and the CMS Collaboration at the Large
Hadron Collider, it is proposed that the standard model of Glashow, Weinberg,
and Salam should be augmented by scalar quarks, scalar leptons, and additional
fermions. If these scalar quarks and scalar leptons are in one-to-one
correspondence with the ordinary quarks and ordinary leptons, either in number
or in the degrees of freedom, then there may be a fermion-boson symmetry. The
fermion-boson symmetry obtained this way is of a different nature from that of
supersymmetry.


title:
Effects of Crowding Perception on Self-organized Pedestrian Flows Using
  Adaptive Agent-based Model

abstract:
  Pedestrian behavior has much more complicated characteristics in a dense
crowd and thus attracts the widespread interest of scientists and engineers.
However, even successful modeling approaches such as pedestrian models based on
particle systems are still not fully considered the perceptive mechanism
underlying collective pedestrian behavior. This paper extends a behavioral
heuristics-based pedestrian model to an adaptive agent-based model, which
explicitly considers the crowding effect of neighboring individuals and
perception anisotropy on the representation of a pedestrians visual
information. The adaptive agents with crowding perception are constructed to
investigate complex, selforganized collective dynamics of pedestrian motion.
The proposed model simulates selforganized pedestrian flows in good
quantitative agreement with empirical data. The selforganized phenomena include
lane formation in bidirectional flow and fundamental diagrams of unidirectional
flow. Simulation results show that the emergence of lane formation in
bidirectional flow can be well reproduced. To investigate this further,
increasing view distance has a significant effect on reducing the number of
lanes, increasing lane width, and stabilizing the self-organized lanes. The
paper also discusses phase transitions of fundamental diagrams of pedestrian
crowds with unidirectional flow. It is found that the heterogeneity of how
pedestrians perceive crowding in the population has a remarkable impact on the
flow quality, which results in the buildup of congestion and rapidly decreases
the efficiency of pedestrian flows. It also indicates that the concept of
heterogeneity may be used to explain the instability of phase transitions.


title: New proofs of theorems of Kathryn Mann

abstract:
  We give a shorter proof of the following theorem of Kathryn Mann \cite{M}:
the identity component of the group of the compactly supported $C^r$
diffeomorphisms of $\R^n$ cannot admit a nontrivial $C^p$-action on $S^1$,
provided $n\geq2$, $r\neq n+1$ and $p\geq2$. We also give a new proof of
another theorem of Mann: any nontrivial endomorphism of the group of the
orientation preserving $C^r$ diffeomorphisms of the circle is the conjugation
by a $C^r$ diffeomorphism, if $r\geq3$.


title: The Large Rank of a Finite Semigroup using Prime Subsets

abstract:
  The \emph{large rank} of a finite semigroup $\Gamma$, denoted by
$r_5(\Gamma)$, is the least number $n$ such that every subset of $\Gamma$ with
$n$ elements generates $\Gamma$. Howie and Ribeiro showed that $r_5(\Gamma) =
|V| + 1$, where $V$ is a largest proper subsemigroup of $\Gamma$. This work
considers the complementary concept of subsemigroups, called \emph{prime
subsets}, and gives an alternative approach to find the large rank of a finite
semigroup. In this connection, the paper provides a shorter proof of Howie and
Ribeiro's result about the large rank of Brandt semigroups. Further, this work
obtains the large rank of the semigroup of order-preserving singular selfmaps.


title: Shallow Water Waves and Solitary Waves

abstract:
  Encyclopedic article covering shallow water wave models used in oceanography
and atmospheric science. Sections: Definition of the Subject; Introduction and
Historical Perspective; Completely Integrable Shallow Water Wave Equations;
Shallow Water Wave Equations of Geophysical Fluid Dynamics; Computation of
Solitary Wave Solutions; Numerical Methods; Water Wave Experiments and
Observations; Future Directions, and Bibliography.


title: Derivation of the Born rule based on the minimal set of assumptions

abstract:
  The Born rule for probabilities of measurement results is deduced from the
set of five assumptions. The assumptions state that: (a) the state vector fully
determines the probabilities of all measurement results; (b) between
measurements, any quantum system is governed by that part of standard quantum
mechanics, which does not refer to measurements; (c) probabilities of
measurement results obey the rules of the classical theory of probability; (d)
no information transfer is possible without interaction; (e) if two spin-1/2
particles are in the entangled state (sqrt(1-\lambda)|up>|up> +
sqrt(\lambda)|down>|down>), and one of spins is measured by the Stern-Gerlach
apparatus, then the state of the other spin after this measurement will be
either |up> or |down>, corresponding to the measurement result. No one of these
assumptions can be omitted. The method of the derivation is based on Zurek's
idea of environment-assisted invariance [PRL 90, 120404 (2003)], though taken
in rather modified form. Entanglement plays a crucial role in our approach
(like in Zurek's one), so the probabilities are first considered in the case
when the measured quantum system is entangled with some environment.
Probabilities in pure states appear then as a particular case. The method of
the present paper can be applied to both ideal and non-ideal measuring devices,
irrespective to their constructions and principles of operation.


title:
Weak Hardy Spaces $WH_L^p({\mathbb R}^n)$ Associated to Operators
  Satisfying $k$-Davies-Gaffney Estimates

abstract:
  Let $L$ be a one-to-one operator of type $\omega$ having a bounded $H_\infty$
functional calculus and satisfying the $k$-Davies-Gaffney estimates with
$k\in{\mathbb N}$. In this paper, the authors introduce the weak Hardy space
$WH_L^p(\mathbb{R}^n)$ associated to $L$ for $p\in (0,\,1]$ via the
non-tangential square function $S_L$ and establish a weak molecular
characterization of $WH_L^p(\mathbb{R}^n)$. Typical examples of such operators
include the $2k$-order divergence form homogeneous elliptic operator
$L_1:=(-1)^k\sum_{|\alpha|=k=|\beta|}\partial^\beta(a_{\alpha,\beta}\partial^\alpha)$,
where $\{a_{\alpha,\beta}\}_{|\alpha|=k=|\beta|}$ are complex bounded
measurable functions, and the $2k$-order Schr\"odinger type operator $L_2:=
(-\Delta)^k+V^k$, where $\Delta$ is the Laplacian operator and $0\le V\in
L^k_{\mathop\mathrm{loc}}(\mathbb{R}^n)$. As applications, for $i\in\{1,\,2\}$
and $p\in(\frac{n}{n+k},\,1]$, the authors prove that the associated Riesz
transform $\nabla^k (L_i^{-1/2})$ is bounded from $WH^p_{L_i}(\mathbb{R}^n)$ to
the classical weak Hardy space $WH^p(\mathbb{R}^n)$ and, for all $0<p<r\le1$
and $\alpha=n(\frac{1}{p}-\frac{1}{r})$, the fractional power
$L_i^{-\frac{\alpha}{2k}}$ is bounded from $WH_{L_i}^p(\mathbb{R}^n)$ to
$WH_{L_i}^r(\mathbb{R}^n)$. Furthermore, the authors find the dual space of
$WH_L^p(\mathbb{R}^n)$ for $p\in(0,\,1]$, which can be defined via mean
oscillations based on some subtle coverings of bounded open sets and, even when
$L:=-\Delta$, are also previously unknown. In particular, if $L$ is a
nonnegative self-adjoint operator in $L^2({\mathbb R}^n)$ satisfying the
Davies-Gaffney estimates, the authors further establish the weak atomic
characterization of $WH_L^p(\mathbb{R}^n)$.


title: On integral fusion categories with low-dimensional simple objects

abstract:
  Let $k$ be an algebraically closedfield of characteristic zero. In this paper
we consider an integral fusion category over $k$ in which the Frobenius-Perron
dimensions of its simple objects are at most 3. We prove that such fusion
category is of Frobenius type. In addition, we also prove that such fusion
category is not simple.


title: Entanglement of spin-orbit qubits induced by Coulomb interaction

abstract:
  Spin-orbit qubit (SOQ) is the dressed spin by the orbital degree of freedom
through a strong spin-orbit coupling. We show that Coulomb interaction between
two electrons in quantum dots located separately in two nanowires can
efficiently induce quantum entanglement between two SOQs. The physical
mechanism to achieve such quantum entanglement is based on the feasibility of
the SOQ responding to the external electric field via an intrinsic electric
dipole spin resonance.


title: Gravitational waves in bimetric MOND

abstract:
  I consider the weak field limit (WFL) of bimetric MOND (BIMOND): the lowest
order in the small departures Hmn and H'mn from double Minkowski space-time. In
particular, I look at propagating solutions, for a favorite subclass of BIMOND.
The WFL splits into two sectors for two linear combinations, Hmn+ and Hmn-, of
Hmn and H'mn. The Hmn+ sector is equivalent to the WFL of general relativity
(GR), with its gauge freedom, and has the same vacuum gravitational waves. The
Hmn- sector is fully nonlinear even for the weakest Hmn-, and inherits none of
the coordinate gauge freedom. The equations of motion are scale invariant in
the deep-MOND limit of purely gravitational systems. In these last two regards,
the BIMOND WFL is greatly different from that of other bimetric theories
studied to date. Despite the strong nonlinearity, an arbitrary pair of harmonic
GR wave packets of Hmn and H'mn moving in the same direction, is a solution of
the (vacuum) BIMOND WFL.


title:
Non-Gaussian statistics for the motion of self-propelled Janus
  particles: experiment versus theory

abstract:
  Spherical Janus particles are one of the most prominent examples for active
Brownian objects. Here, we study the diffusiophoretic motion of such
microswimmers in experiment and in theory. Three stages are found: simple
Brownian motion at short times, super-diffusion at intermediate times, and
finally diffusive behavior again at long times. These three regimes observed in
the experiments are compared with a theoretical model for the Langevin dynamics
of self-propelled particles with coupled translational and rotational motion.
Besides the mean square displacement also higher displacement moments are
addressed. In particular, theoretical predictions regarding the non-Gaussian
behavior of self-propelled particles are verified in the experiments.
Furthermore, the full displacement probability distribution is analyzed, where
in agreement with Brownian dynamics simulations either an extremely broadened
peak or a pronounced double-peak structure is found depending on the
experimental conditions.


title:
The restricted consistency property of leave-$n_v$-out cross-validation
  for high-dimensional variable selection

abstract:
  Cross-validation (CV) methods are popular for selecting the tuning parameter
in the high-dimensional variable selection problem. We show the mis-alignment
of the CV is one possible reason of its over-selection behavior. To fix this
issue, we propose a version of leave-$n_v$-out cross-validation (CV($n_v$)),
for selecting the optimal model among the restricted candidate model set for
high-dimensional generalized linear models. By using the same candidate model
sequence and a proper order of construction sample size $n_c$ in each CV split,
CV($n_v$) avoids the potential hurdles in developing theoretical properties.
CV($n_v$) is shown to enjoy the restricted model selection consistency property
under mild conditions. Extensive simulations and real data analysis support the
theoretical results and demonstrate the performances of CV($n_v$) in terms of
both model selection and prediction.


title:
Uniqueness of the minimizer for a random nonlocal functional with
  double-well potential in $d\le2$

abstract:
  We consider a small random perturbation of the energy functional $$
[u]^2_{H^s(\Lambda, R^d)} + \int_\Lambda W(u(x)) dx $$ for $s \in (0,1),$ where
the non-local part $ [u]^2_{H^s(\Lambda,R^d)}$ denotes the total contribution
from $\Lambda \subset R^d$ in the $H^s (R^d)$ Gagliardo semi-norm of $u$ and
$W$ is a double well potential. We show that there exists, as $\Lambda $
invades $ R^d$, for almost all realizations of the random term a minimizer
under compact perturbations, which is unique when $d=2$, $s \in (\frac 12,1)$
and when $d=1$, $s \in [\frac 14, 1).$ This uniqueness is a consequence of the
randomness. When the random term is absent, there are two minimizers which are
invariant under translations in space, $u = \pm 1$.


title:
Bounds for global coefficients in the fine geometric expansion of
  Arthur's trace formula for GL(n)

abstract:
  We give upper bounds for the absolute value of the global coefficients
appearing in the fine geometric expansion of Arthur's trace formula for GL(n).


title: Number of lines in hypergraphs

abstract:
  Chen and Chv\'atal introduced the notion of lines in hypergraphs; they proved
that every 3-uniform hypergraph with $n$ vertices either has a line that
consists of all $n$ vertices or else has at least $\log_2 n$ distinct lines. We
improve this lower bound by a factor of $2-o(1)$.


title:
Zeta Functions for the Adjoint Action of GL(n) and density of residues
  of Dedekind zeta functions

abstract:
  We define zeta functions for the adjoint action of GL(n) on its Lie algebra
and study their analytic properties. For n<4 we are able to fully analyse these
functions, and recover the Shintani zeta function for the prehomogeneous vector
space of binary quadratic forms for n=2. Our construction naturally yields a
regularisation, which is necessary for the improvement of the properties of
these zeta function, in particular for the analytic continuation if n>2.
  We further obtain upper and lower bounds on the mean value X^{-5/2}\sum_{E}
\res_{s=1}\zeta_E(s) as X->\infty, where E runs over totally real cubic number
fields whose second successive minimum of the trace form on its ring of
integers is bounded by X. To prove the upper bound we use our new zeta function
for GL(3). These asymptotic bounds are a first step towards a generalisation of
density results obtained by Datskovsky in case of quadratic field extensions.


title: Toward an Interactive Directory for Norfolk, Nebraska: 1899-1900

abstract:
  We describe steps toward an interactive directory for the town of Norfolk,
Nebraska for the years 1899 and 1900. This directory would extend the
traditional city directory by including a wider range of entities being
described, much richer information about the entities mentioned and linkages to
mentions of the entities in material such as digitized historical newspapers.
Such a directory would be useful to readers who browse the historical
newspapers by providing structured summaries of the entities mentioned. We
describe the occurrence of entities in two years of the Norfolk Weekly News,
focusing on several individuals to better understand the types of information
which can be gleaned from historical newspapers and other historical materials.
We also describe a prototype program which coordinates information about
entities from the traditional city directories, the federal census, and from
newspapers. We discuss the structured coding for these entities, noting that
richer coding would increasingly include descriptions of events and scenarios.
We propose that rich content about individuals and communities could eventually
be modeled with agents and woven into historical narratives.


title: Maximal bifix decoding

abstract:
  We introduce a class of sets of words which is a natural common
generalization of Sturmian sets and of interval exchange sets. This class of
sets consists of the uniformly recurrent tree sets, where the tree sets are
defined by a condition on the possible extensions of bispecial factors. We
prove that this class is closed under maximal bifix decoding. The proof uses
the fact that the class is also closed under decoding with respect to return
words.


title:
Cooperative ISP Traffic Shaping Schemes in Broadband Shared Access
  Networks

abstract:
  Traffic shaping is a mechanism used by Internet Service Providers (ISPs) to
limit subscribers' traffic based on their service contracts. This paper
investigates the current implementation of traffic shaping based on the token
bucket filter (TBF), discusses its advantages and disadvantages, and proposes a
cooperative TBF that can improve subscribers' quality of service (QoS)/quality
of experience (QoE) without compromising business aspects of the service
contract model by proportionally allocating excess bandwidth from inactive
subscribers to active ones based on the long-term bandwidths per their service
contracts.


title:
A thermal quench induces spatial inhomogeneities in a holographic
  superconductor

abstract:
  Holographic duality is a powerful tool to investigate the far-from
equilibrium dynamics of superfluids and other phases of quantum matter. For
technical reasons it is usually assumed that, after a quench, the far-from
equilibrium fields are still spatially uniform. Here we relax this assumption
and study the time evolution of a holographic superconductor after a
temperature quench but allowing spatial variations of the order parameter. Even
though the initial state and the quench are spatially uniform we show the order
parameter develops spatial oscillations with an amplitude that increases with
time until it reaches a stationary value. The free energy of these
inhomogeneous solutions is lower than that of the homogeneous ones. Therefore
the former corresponds to the physical configuration that could be observed
experimentally.


title: Stirling permutations on multisets

abstract:
  A permutation $\sigma$ of a multiset is called Stirling permutation if
$\sigma(s)\ge \sigma(i)$ as soon as $\sigma(i)=\sigma(j)$ and $i<s<j.$ In our
paper we study Stirling polynomials that arise in the generating function for
descent statistics on Stirling permutations of any multiset. We develop
generalizations of the classical Stirling numbers and present their
combinatorial interpretations. Particularly, we apply the theory of
$P$-partitions. Using certain specifications we also introduce the Stirling
numbers of odd type and generalizations of the central factorial numbers.


title: Bounding the socles of powers of squarefree monomial ideals

abstract:
  Let $S=K[x_1,\ldots,x_n]$ be the polynomial ring in $n$ variables over a
field $K$ and $I\subset S$ a squarefree monomial ideal. In the present paper we
are interested in the monomials $u \in S$ belonging to the socle
$\Soc(S/I^{k})$ of $S/I^{k}$, i.e., $u \not\in I^{k}$ and $ux_{i} \in I^{k}$
for $1 \leq i \leq n$. We prove that if a monomial $x_1^{a_1}\cdots x_n^{a_n}$
belongs to $\Soc(S/I^{k})$, then $a_i\leq k-1$ for all $1 \leq i \leq n$. We
then discuss squarefree monomial ideals $I \subset S$ for which $x_{[n]}^{k-1}
\in \Soc(S/I^{k})$, where $x_{[n]} = x_{1}x_{2}\cdots x_{n}$. Furthermore, we
give a combinatorial characterization of finite graphs $G$ on $[n] = \{1,
\ldots, n\}$ for which $\depth S/(I_{G})^{2}=0$, where $I_{G}$ is the edge
ideal of $G$.


title: Normality and Sharing Functions

abstract:
  In this article, we prove a normality criterion for a family of meromorphic
functions which involves sharing of holomorphic functions. Our result
generalizes some of the results of H. H. Chen, M. L. Fang and M. Han, Y. Gu.


title:
Classification of non conformally flat cylindrically symmetric non
  static space-times according to their proper conformal motions

abstract:
  In this paper we considered the most general form of non conformally flat
cylindrically symmetric non-static space-times to study proper conformal
motions using direct integration technique. We have shown that very special
classes for cylindrically symmetric space-times admit proper conformal motions.
This classification also covers non-static and static plane symmetric
space-times. In [9] it was claimed that non conformally flat plane symmetric
static space-times do not admit proper conformal motion. Here it is also shown
that static and non static plane symmetric space-times admit proper conformal
motions. We also discuss the Lie algebra in each case.


title: The compressibility of rotating black holes in D-dimensions

abstract:
  Treating the cosmological constant as a pressure, in the context of black
hole thermodynamics, a thermodynamic volume for the black hole can be defined
as being the thermodynamic variable conjugate to the pressure, in the sense of
a Legendre transform. The thermodynamic volume is explicitly calculated, as the
Legendre transform of the pressure in the enthalpy for a rotating
asymptotically anti-de Sitter Myers-Perry black hole in D space-time
dimensions. The volume obtained is shown to agree with previous calculations
using the Smarr relation. The compressibility is calculated and shown to be
non-negative and bounded.
  Taking the limit of zero cosmological constant, the compressibility of a
rotating black hole in asymptotically flat space-times is determined and the
corresponding speed of sound computed. The latter is bounded above and has an
elegant expression purely in terms of the angular momenta, in the form of
quartic and quadratic Casimirs of the rotation group, SO(D-1).


title:
Universal scheme for violation of local realism from quantum advantage
  in one-way communication complexity

abstract:
  We consider relations between communication complexity problems and detecting
correlations (violating local realism) with no local hidden variable model. We
show first universal equivalence between characteristics of protocols used in
that type of problems and non-signaling correlations. We construct non linear
bipartite Bell type inequalities and strong nonlocality test with binary
observables by providing general method of Bell inequalities construction and
showing that existence of gap between quantum and classical complexity leads to
violation of these inequalities. We obtain, first to our knowledge, explicit
Bell inequality with binary observables and exponential violation.


title:
Prefrontal control of the amygdala during real-time fMRI neurofeedback
  training of emotion regulation

abstract:
  We observed in a previous study (PLoS ONE 6:e24522) that the self-regulation
of amygdala activity via real-time fMRI neurofeedback (rtfMRI-nf) with positive
emotion induction was associated, in healthy participants, with an enhancement
in the functional connectivity between the left amygdala (LA) and six regions
of the prefrontal cortex. These regions included the left rostral anterior
cingulate cortex (rACC), bilateral dorsomedial prefrontal cortex (DMPFC),
bilateral superior frontal gyrus (SFG), and right medial frontopolar cortex
(MFPC). Together with the LA, these six prefrontal regions thus formed the
functional neuroanatomical network engaged during the rtfMRI-nf procedure. Here
we perform a structural vector autoregression (SVAR) analysis of the effective
connectivity for this network. The SVAR analysis demonstrates that the left
rACC plays an important role during the rtfMRI-nf training, modulating the LA
and the other network regions. According to the analysis, the rtfMRI-nf
training leads to a significant enhancement in the time-lagged effect of the
left rACC on the LA. The training is also accompanied by significant increases
in the instantaneous (contemporaneous) effects of the left rACC on four other
regions - the bilateral DMPFC, the right MFPC, and the left SFG. The
instantaneous effects of the LA on the bilateral DMPFC are also significantly
enhanced. Our results are consistent with a broad literature supporting the
role of the rACC in emotion processing and regulation. Our analysis provides,
for the first time, insights into the causal relationships within the network
of regions engaged during the rtfMRI-nf procedure targeting the amygdala. It
suggests that the rACC may constitute a promising target for rtfMRI-nf training
along with the amygdala in patients with affective disorders, particularly
posttraumatic stress disorder (PTSD).


title:
Accretion from debris disks onto white dwarfs : Fingering (thermohaline)
  instability and derived accretion rates

abstract:
  Recent observations of a large number of DA and DB white dwarfs show evidence
of debris disks, which are the remnants of old planetary systems. The infrared
excess detected with \emph{Spitzer} and the lines of heavy elements observed in
their atmospheres with high-resolution spectroscopy converge on the idea that
planetary material accretes onto these stars. Accretion rates have been derived
by several authors with the assumption of a steady state between accretion and
gravitational settling. The results are unrealistically different for DA and DB
white dwarfs. When heavy matter is accreted onto stars, it induces an inverse
$\mu$-gradient that leads to fingering (thermohaline) convection. The aim of
this letter is to study the impact of this specific process on the derived
accretion rates in white dwarfs and on the difference between DA and DB. We
solve the diffusion equation for the accreted heavy elements with a
time-dependent method. The models we use have been obtained both with the IRAP
code, which computes static models, and the La Plata code, which computes
evolutionary sequences. Computations with pure gravitational settling are
compared with computations that include fingering convection. The most
important result is that fingering convection has very important effects on DAs
but is inefficient in DBs. When only gravitational settling is taken into
account, the time-dependent computations lead to a steady state, as postulated
by previous authors. When fingering convection is added, this steady state
occurs much later. The surprising difference found in the past for the
accretion rates derived for DA and DB white dwarfs disappears. The derived
accretion rates for DAs are increased when fingering convection is taken into
account, whereas those for DBs are not modified. More precise and developed
results will be given in a forthcoming paper.


title: Magnitude, diversity, capacities, and dimensions of metric spaces

abstract:
  Magnitude is a numerical invariant of metric spaces introduced by Leinster,
motivated by considerations from category theory. This paper extends the
original definition for finite spaces to compact spaces, in an equivalent but
more natural and direct manner than in previous works by Leinster, Willerton,
and the author. The new definition uncovers a previously unknown relationship
between magnitude and capacities of sets. Exploiting this relationship, it is
shown that for a compact subset of Euclidean space, the magnitude dimension
considered by Leinster and Willerton is equal to the Minkowski dimension.


title:
Spontaneous Spatial Inversion Symmetry Breaking and Spin Hall Effect in
  a Spin-ice Double-exchange Model on a Pyrochlore Lattice

abstract:
  A formation of tetrahedral spin clusters is discovered by Monte Carlo
simulation for a spin-ice type double-exchange model on a pyrochlore lattice.
The spin-cluster phase is magnetically disordered, but breaks spatial inversion
symmetry spontaneously by developing noncoplanar four-spin molecules
periodically on the pyrochlore lattice. We find that the system exhibits a
nonzero spin Hall conductivity in the spin-cluster phase. The result suggests
that an intersite-multipole order induces the unconventional spin Hall state
without the spin-orbit interaction.


title: Second-Order Algebraic Theories

abstract:
  Fiore and Hur recently introduced a conservative extension of universal
algebra and equational logic from first to second order. Second-order universal
algebra and second-order equational logic respectively provide a model theory
and a formal deductive system for languages with variable binding and
parameterised metavariables. This work completes the foundations of the subject
from the viewpoint of categorical algebra. Specifically, the paper introduces
the notion of second-order algebraic theory and develops its basic theory. Two
categorical equivalences are established: at the syntactic level, that of
second-order equational presentations and second-order algebraic theories; at
the semantic level, that of second-order algebras and second-order functorial
models. Our development includes a mathematical definition of syntactic
translation between second-order equational presentations. This gives the first
formalisation of notions such as encodings and transforms in the context of
languages with variable binding.


title: Mimetic Dark Matter

abstract:
  We reformulate Einstein's theory of gravity, isolating the conformal degree
of freedom in a covariant way. This is done by introducing a physical metric
defined in terms of an auxiliary metric and a scalar field appearing through
its first derivatives. The resulting equations of motion split into a traceless
equation obtained through variation with respect to the auxiliary metric and an
additional differential equation for the trace part. As a result the conformal
degree of freedom becomes dynamical even in the absence of matter. We show that
this extra degree of freedom can mimic cold dark matter.


title: Analysis of Twisted Supercharge Families on Product Manifolds

abstract:
  Twisted supercharge families on product manifolds $\mathbb{T} \times M$ have
been applied in the analysis of the odd twisted K-theory. We shall suspend
these families to the even twisted K-theory and solve their twisted families
index problem. This is applied to give analytic representatives of the twisted
K-theory classes on tori - including all the torsion classes.


title: The Complex Angle in Normed Spaces

abstract:
  We consider a generalized angle in complex normed vector spaces. Its
definition corresponds to the definition of the well known Euclidean angle in
real inner product spaces. Not surprisingly it yields complex values as
`angles'. This `angle' has some simple properties, which are known from the
usual angle in real inner product spaces. But to do ordinary Euclidean geometry
real angles are necessary. We show that even in a complex normed space there
are many pure real valued `angles'. The situation improves yet in inner product
spaces. There we can use the known theory of orthogonal systems to find many
pairs of vectors with real angles, and to do geometry which is based on the
Greeks 2000 years ago.


title:
Determining eigenvalues of a density matrix with minimal information in
  a single experimental setting

abstract:
  Eigenvalues of a density matrix characterize well the quantum state's
properties, such as coherence and entanglement. We propose a simple method to
determine all the eigenvalues of an unknown density matrix of a
finite-dimensional system in a single experimental setting. Without fully
reconstructing a quantum state, eigenvalues are determined with the minimal
number of parameters obtained by a measurement of a single observable.
Moreover, its implementation is illustrated in linear optical and
superconducting systems.


title: White dwarf constraints on a varying $G$

abstract:
  A secular variation of $G$ modifies the structure and evolutionary time
scales of white dwarfs. Using an state-of-the-art stellar evolutionary code, an
up-to-date pulsational code, and a detailed population synthesis code we
demonstrate that the effects of a running $G$ are obvious both in the
properties of individual white dwarfs, and in those of the white dwarf
populations in clusters. Specifically, we show that the white dwarf
evolutionary sequences depend on both the value of $\dot G/G$, and on the value
of $G$ when the white dwarf was born. We show as well that the pulsational
properties of variable white dwarfs can be used to constrain $\dot G/G$.
Finally, we also show that the ensemble properties of of white dwarfs in
clusters can also be used to set upper bounds to $\dot G/G$. Precisely, the
tightest bound --- $\dot G/G \sim -1.8 10^{-12}$ yr$^{-1}$ --- is obtained
studying the population of the old, metal-rich, well populated, open cluster
NGC 6791. Less stringent upper limits can be obtained comparing the theoretical
results obtained taking into account the effects of a running $G$ with the
measured rates of change of the periods of two well studied pulsating white
dwarfs, G117--B15A and R548. Using these white dwarfs we obtain $\dot G/G\sim
-1.8\times 10^{-10}$ yr$^{-1}$, and $\dot G/G\sim -1.3\times 10^{-10}$
yr$^{-1}$, respectively, which although less restrictive than the previous
bound, can be improved measuring the rate of change of the period of massive
white dwarfs.


title:
Formation and Dynamics of Vortex Structures in Pure and Gas-Discharge
  Nonneutral Collisionless Electron Plasmas

abstract:
  The comparative analysis of the results of experimental investigations of the
processes of formation, interaction and dynamics of vortex structures in pure
electron and gas-discharge electron nonneutral plasmas taking place for the
period of time much less than the electron-neutral collision time has been
given. The general processes of formation and behavior of vortex structures in
these two plasmas were considered. The phenomena, taking place only in one of
these plasmas were also considered. It is shown that the existing difference in
behavior of vortex structures is caused by different initial states of
nonneutral electron plasmas. The role of vortex structures in the processes
taking place in nonneutral electron plasma is discussed.


title:
Estimation of the Szlenk index of reflexive Banach spaces using
  generalized Baernstein spaces

abstract:
  For each ordinal $\alpha< \omega_1$, we prove the existence of a separable,
reflexive Banach space with a basis and Szlenk index $\omega^{\alpha+1}$ which
is universal for the class of separable, reflexive Banach spaces $X$ such that
the Szlenk indices $Sz(X), Sz(X^*)$ do not exceed $\omega^\alpha$.


title: Open problems and questions about geodesics

abstract:
  The paper surveys open problems and questions related to geodesics defined by
Riemannian, Finsler, semi Riemannian and magnetic structures on manifolds.


title: The Rokhlin dimension of topological Z^m-actions

abstract:
  We study the topological variant of Rokhlin dimension for topological
dynamical systems (X,{\alpha},Z^m) in the case where X is assumed to have
finite covering dimension. Finite Rokhlin dimension in this sense is a property
that implies finite Rokhlin dimension of the induced action on C*-algebraic
level, as was discussed in a recent paper by Ilan Hirshberg, Wilhelm Winter and
Joachim Zacharias. In particular, it implies under these conditions that the
transformation group C*-algebra has finite nuclear dimension. Generalizing a
result of Yonatan Gutman, we show that free Z^m-actions on finite dimensional
spaces satisfy a strengthened version of the so-called marker property, which
yields finite Rokhlin dimension for said actions.


title:
Simulation of beam induced lattice defects of diamond detectors using
  FLUKA

abstract:
  Diamond is more and more used as detector material for particle detection.
One argument for diamond is its higher radiation hardness compared to silicon.
Since various particles have different potential for radiation damage at
different energies a scaling rule is necessary for the prediction of radiation
damage. For silicon detectors the non-ionising energy loss (NIEL) is used for
scaling the effects of different particles. A different way of predicting the
radiation damage is based on the Norget-Robinson-Torrens theorem to predict the
number of displacements per atom (DPA). This provides a better scaling rule
since recombination effects are taken into account. This model is implemented
in the FLUKA Monte Carlo simulations package for protons, neutrons and pions.
We compare simulation results of NIEL and DPA for diamond and silicon material
exposed to protons, neutrons and pions for a wide range of energies.


title:
Exhaustive generation of `Mrs Perkins's quilt' square dissections for
  low orders

abstract:
  Dissections of a square into smaller squares, with the smaller squares having
relatively prime sizes, are known as Mrs Perkins's quilts. A representation of
these dissections using graphs is presented. The edges are directed and
coloured North-South or West-East, and the graph corresponds naturally to the
dissection. This representation allowed the exhaustive generation of all
dissections up to order 18, using the plantri software. The results were
cross-checked by generating all dissections of small sizes using a direct
approach. The results confirm, extend and introduce several integer sequences.


title: Measuring Privacy Leakage for IDS Rules

abstract:
  This paper proposes a measurement approach for estimating the privacy leakage
from Intrusion Detection System (IDS) alarms. Quantitative information flow
analysis is used to build a theoretical model of privacy leakage from IDS
rules, based on information entropy. This theoretical model is subsequently
verified empirically both based on simulations and in an experimental study.
The analysis shows that the metric is able to distinguish between IDS rules
that have no or low expected privacy leakage and IDS rules with a significant
risk of leaking sensitive information, for example on user behaviour. The
analysis is based on measurements of number of IDS alarms, data length and data
entropy for relevant parts of IDS rules (for example payload). This is a
promising approach that opens up for privacy benchmarking of Managed Security
Service providers.


title:
A key physical mechanism for understanding the enigmatic linear
  polarization of the solar BaII and NaI D1 lines

abstract:
  The linearly polarized spectrum of the solar limb radiation produced by
scattering processes is of great diagnostic potential for exploring the
magnetism of the solar atmosphere. This spectrum shows an impressive richness
of spectral details and enigmatic Q/I signals, whose physical origin must be
clearly understood before they can be exploited for diagnostic purposes. The
most enduring enigma is represented by the polarization signals observed in the
D1 resonance lines of Na I (5896 A) and Ba II (4934 A), which were expected to
be intrinsically unpolarizable. The totality of sodium and 18% of barium have
hyperfine structure (HFS), and it has been argued that the only way to produce
a scattering polarization signal in such lines is through the presence of a
substantial amount of atomic polarization in their lower HFS levels. The strong
sensitivity of these long-lived levels to depolarizing mechanisms led to the
paradoxical conclusion that the observed D1-line polarization is incompatible
with the presence in the lower solar chromosphere of inclined magnetic fields
sensibly stronger than 0.01 G. Here we show that by properly taking into
account the fact that the solar D1-line radiation has a non-negligible spectral
structure over the short frequency interval spanned by the HFS transitions, it
is possible to produce scattering polarization signals in the D1 lines of Na I
and Ba II without the need of ground-level polarization. The resulting linear
polarization is not so easily destroyed by elastic collisions and/or magnetic
fields.


title: A Literature Review: Stemming Algorithms for Indian Languages

abstract:
  Stemming is the process of extracting root word from the given inflection
word. It also plays significant role in numerous application of Natural
Language Processing (NLP). The stemming problem has addressed in many contexts
and by researchers in many disciplines. This expository paper presents survey
of some of the latest developments on stemming algorithms in data mining and
also presents with some of the solutions for various Indian language stemming
algorithms along with the results.


title:
Exponential improvement in precision for Hamiltonian-evolution
  simulation

abstract:
  We provide a quantum method for simulating Hamiltonian evolution with
complexity polynomial in the logarithm of the inverse error. This is an
exponential improvement over existing methods for Hamiltonian simulation. In
addition, its scaling with respect to time is close to linear, and its scaling
with respect to the time derivative of the Hamiltonian is logarithmic. These
scalings improve upon most existing methods. Our method is to use a compressed
Lie-Trotter formula, based on recent ideas for efficient discrete-time
simulations of continuous-time quantum query algorithms.


title:
Debye Sources, Beltrami Fields, and a Complex Structure on Maxwell
  Fields

abstract:
  The Debye source representation for solutions to the time harmonic Maxwell
equations is extended to bounded domains with finitely many smooth boundary
components. A strong uniqueness result is proved for this representation.
Natural complex structures are identified on the vector spaces of time-harmonic
Maxwell fields. It is shown that in terms of Debye source data, these complex
structures are uniformized, that is, represented by a fixed linear map on a
fixed vector space, independent of the frequency. This complex structure
relates time-harmonic Maxwell fields to constant-k Beltrami fields, i.e.
solutions of the equation curl(E) = kE. A family of self-adjoint boundary
conditions are defined for the Beltrami operator. This leads to a proof of the
existence of zero-flux, constant-k, force-free Beltrami fields for any bounded
region in R^3, as well as a constructive method to find them. The family of
self-adjoint boundary value problems defines a new spectral invariant for
bounded domains in R^3.

categories: math.NA math-ph math.AP math.MP physics.plasm-ph


title:
GPU-based simulation of the long-range Potts model via parallel
  tempering

abstract:
  We discuss the efficiency of parallelization on graphical processing units
(GPUs) for the simulation of the one dimensional Potts model with long range
interactions via parallel tempering. We investigate the behaviour of some
thermodynamic properties, such as equilibrium energy and magnetization,
critical temperatures as well as the separation between the first- and
second-order regime. By implementing multispin coding techniques and an
efficient parallelization of the interaction energy computation among threads,
the GPU-accelerated approach reached speedup factors of up to 37.


title:
Adaptive Posterior Convergence Rates in Bayesian Density Deconvolution
  with Supersmooth Errors

abstract:
  Bayesian density deconvolution using nonparametric prior distributions is a
useful alternative to the frequentist kernel based deconvolution estimators due
to its potentially wide range of applicability, straightforward uncertainty
quantification and generalizability to more sophisticated models. This article
is the first substantive effort to theoretically quantify the behavior of the
posterior in this recent line of research. In particular, assuming a known
supersmooth error density, a Dirichlet process mixture of Normals on the true
density leads to a posterior convergence rate same as the minimax rate $(\log
n)^{-\eta/\beta}$ adaptively over the smoothness $\eta$ of an appropriate
H\"{o}lder space of densities, where $\beta$ is the degree of smoothness of the
error distribution. Our main contribution is achieving adaptive minimax rates
with respect to the $L_p$ norm for $2 \leq p \leq \infty$ under mild regularity
conditions on the true density. En route, we develop tight concentration bounds
for a class of kernel based deconvolution estimators which might be of
independent interest.


title: Busseman functions for the N-body problem

abstract:
  We prove that the Busemann function of the parabolic homotetic motion for a
minimal central coniguration of the N-body problem is a viscosity solution of
the Hamilton-Jacobi equation and that its calibrating curves are asymptotic to
the homotetic motion.


title: Helical magnetic fields in the M87 jet at arc-second scales

abstract:
  We investigate the magnetic field configuration of the M87 jet at arc-second
scales by using archival polarimetric VLA data at 8, 15, 22 and 43 GHz. By
stacking images over three years in order to enhance the sensitivity, we
reveal, for the first time, systematic transverse gradients of the Faraday
rotation measure in several knots along the jet. Combining this result with
polarization properties and the dynamics of the jet, we suggest the magnetic
structure in several knots at kiloparsec scales consists of a systematically
wrapped, tightly wound helical configuration. Our analysis brings us a new
paradigm where the M87 jet is a fundamentally current carrying system produced
in the vicinity of the supermassive black hole, transferring a huge amount of
the electromagnetic energy over the host galaxy scale.


title: Fluctuating selection models and McDonald-Kreitman type analyses

abstract:
  It is likely that the strength of selection acting upon a mutation varies
through time due to changes in the environment. However, most population
genetic theory assumes that the strength of selection remains constant. Here we
investigate the consequences of fluctuating selection pressures on the
quantification of adaptive evolution using McDonald-Kreitman (MK) style
approaches. In agreement with previous work, we show that fluctuating selection
can generate evidence of adaptive evolution even when the expected strength of
selection on a mutation is zero. However, we also find that the mutations,
which contribute to both polymorphism and divergence tend, on average, to be
positively selected during their lifetime, under fluctuating selection models.
This is because mutations that fluctuate, by chance, to positive selected
values, tend to reach higher frequencies in the population than those that
fluctuate towards negative values. Hence the evidence of positive adaptive
evolution detected under a fluctuating selection model by MK type approaches is
genuine since fixed mutations tend to be advantageous on average during their
lifetime. Never-the-less we show that methods tend to underestimate the rate of
adaptive evolution when selection fluctuates.


title: Frictionless Racquetball?

abstract:
  When a ball hits a surface, does the angle of reflection always equal the
angle of incidence? Not at all! Depending on the interplay of the ball's spin
and speed and the force of friction, the ball's behavior after the bounce may
differ dramatically. Surely some experienced racquetball, ping-pong, pool,
tennis and players alike take advantage of this fact. A physics teacher, in
turn, can take advantage of the fact that by observing the bounce of a ball her
students can determine the coefficient of friction between the ball and the
floor. All it takes is a typical video (smartphone) camera and some standard
software
  However, this seemingly straightforward method may lead to surprises. If one
wants to double check the value of the coefficient of friction by observing the
second, third etc. bounces, one may find the the force of friction "does not
turn on". We investigate why this happens, state a hypothesis and run some
testing experiments. Teachers who would like to include an illustration of the
scientific cycle at work in their classes may find this paper useful.


title: Haffner 16: A Young Moving Group in the Making

abstract:
  The photometric properties of main sequence (MS) and pre-main sequence (PMS)
stars in the young cluster Haffner 16 are examined using images recorded with
the Gemini South Adaptive Optics Imager (GSAOI) and corrected for atmospheric
blurring by the Gemini Multi-Conjugate Adapative Optics System (GeMS). A rich
population of PMS stars is identified, and comparisons with isochrones suggest
an age < 10 Myr assuming a distance modulus of 13.5 (D = 5 kpc). When compared
with the solar neighborhood, Haffner 16 is roughly a factor of two deficient in
objects with sub-solar masses. PMS objects in the cluster are also more
uniformly distributed on the sky than bright MS stars. It is suggested that
Haffner 16 is dynamically evolved, and that it is shedding protostars with
sub-solar masses. Young low mass clusters like Haffner 16 are one possible
source of PMS stars in the field. The cluster will probably evolve on time
scales of ~ 100 - 1000 Myr into a diffuse moving group with a mass function
that is very different from that which prevailed early in its life.


title:
Entropy and spontaneity in an introductory physics course for life
  science students

abstract:
  In an Introductory Physics for Life Science (IPLS) course that leverages
authentic biological examples, student ideas about entropy as "disorder" or
"chaos" come into contact with their ideas about the spontaneous formation of
organized biological structure. It is possible to reconcile the "natural
tendency to disorder" with the organized clustering of macromolecules, but
doing so in a way that will be meaningful to students requires that we take
seriously the ideas about entropy and spontaneity that students bring to IPLS
courses from their prior experiences in biology and chemistry. We draw on case
study interviews to argue that an approach that emphasizes the interplay of
energy and entropy in determining spontaneity (one that involves a central role
for free energy) is one that draws on students' resources from biology and
chemistry in particularly effective ways. We see the positioning of entropic
arguments alongside energetic arguments in the determination of spontaneity as
an important step toward making our life science students' biology, chemistry,
and physics experiences more coherent.


title: Multilevel Topological Interference Management

abstract:
  The robust principles of treating interference as noise (TIN) when it is
sufficiently weak, and avoiding it when it is not, form the background for this
work. Combining TIN with the topological interference management (TIM)
framework that identifies optimal interference avoidance schemes, a baseline
TIM-TIN approach is proposed which decomposes a network into TIN and TIM
components, allocates the signal power levels to each user in the TIN
component, allocates signal vector space dimensions to each user in the TIM
component, and guarantees that the product of the two is an achievable number
of signal dimensions available to each user in the original network.


title: A Relative Lubin-Tate Theorem via Meromorphic Formal Geometry

abstract:
  We formulate a theory of punctured affine formal schemes, suitable for
certain problems within algebraic topology. As an application, we show that the
Morava K-theoretic localizations of Morava E-theory corepresent a version of
the Lubin-Tate moduli problem in this framework.


title:
Temperature dependent effective third order interatomic force constants
  from first principles

abstract:
  The temperature dependent effective potential (TDEP) method is generalized
beyond pair interactions. The second and third order force constants are
determined consistently from ab initio molecular dynamics simulations at finite
temperature. The reliability of the approach is demonstrated by calculations of
the Mode Gr\"uneisen parameters for Si. We show that the extension of TDEP to
higher order allows for an efficient calculation of the phonon life time, in Si
as well as in $\epsilon$-FeSi, a system that exhibits anomalous softening with
temperature.


title: A Bound for the Locating Chromatic Numbers of Trees

abstract:
  Let $f$ be a proper $k$-coloring of a connected graph $G$ and
$\Pi=(V_1,V_2,\ldots,V_k)$ be an ordered partition of $V(G)$ into the resulting
color classes. For a vertex $v$ of $G$, the color code of $v$ with respect to
$\Pi$ is defined to be the ordered $k$-tuple
$c_{{}_\Pi}(v)=(d(v,V_1),d(v,V_2),\ldots,d(v,V_k)),$ where
$d(v,V_i)=\min\{d(v,x): x\in V_i\}, 1\leq i\leq k$. If distinct vertices have
distinct color codes, then $f$ is called a locating coloring. The minimum
number of colors needed in a locating coloring of $G$ is the locating chromatic
number of $G$, denoted by $\Cchi_{{}_L}(G)$. In this paper, we study the
locating chromatic numbers of trees. We provide a counter example to a theorem
of Gary Chartrand et al. [G. Chartrand, D. Erwin, M.A. Henning, P.J. Slater, P.
Zhang, The locating-chromatic number of a graph, Bull. Inst. Combin. Appl. 36
(2002) 89-101] about the locating chromatic numbers of trees. Also, we offer a
new bound for the locating chromatic number of trees. Then, by constructing a
special family of trees, we show that this bound is best possible.


title: Tunable electronic correlation effects in nanotube-light interactions

abstract:
  Electronic many-body correlation effects in one-dimensional (1D) systems such
as carbon nanotubes have been predicted to modify strongly the nature of
photoexcited states. Here we directly probe this effect using broadband elastic
light scattering from individual suspended carbon nanotubes under electrostatic
gating conditions. We observe significant shifts in optical transition
energies, as well as line broadening, as the carrier density is increased. The
results demonstrate the differing role of screening of many-body electronic
interactions on the macroscopic and microscopic length scales, a feature
inherent to quasi-1D systems. Our findings further demonstrate the possibility
of electrical tuning of optical transitions and provide a basis for
understanding of various optical phenomena in carbon nanotubes and other
quasi-1D systems in the presence of charge carrier doping.


title: Hybrid Inverse Problems for a System of Maxwell's Equations

abstract:
  This paper concerns the quantitative step of the medical imaging modality
Thermo-acoustic Tomography (TAT). We model the radiation propagation by a
system of Maxwell's equations. We show that the index of refraction of light
and the absorption coefficient (conductivity) can be uniquely and stably
reconstructed from a sufficiently large number of TAT measurements. Our method
is based on verifying that the linearization of the inverse problem forms a
redundant elliptic system of equations. We also observe that the
reconstructions are qualitatively quite different from the setting where
radiation is modeled by a scalar Helmholtz equation as in [10].


title: Magnetic Vortices, Abrikosov Lattices and Automorphic Functions

abstract:
  We address the macroscopic theory of superconductivity - the Ginzburg-Landau
theory. This theory %Macroscopic theory of superconductivity is based on the
celebrated Ginzburg - Landau equations. First developed to explain and predict
properties of superconductors, these equations form an integral part -
Abelean-Higgs component - of the standard model of particle physics and, in
general, have a profound influence on physics well beyond their original
designation area. %These are a pair of coupled nonlinear equations for a
complex function (called order parameter or Higgs field) and a vector field
(magnetic potential or gauge field). They are the simplest representatives of a
large family of equations appearing in physics and mathematics. (The latest
variant of these equations is the Seiberg - Witten equations.)


title:
Hadamard-type and Bullen-type inequalities for Lipschitzian functions
  via fractional integrals

abstract:
  In this paper, the author establishes some Hadamard-type and Bullen-type
inequalities for Lipschitzian functions via Riemann Liouville fractional
integral. These results have some relationships with [K.-L. Tseng, S.-R. Hwang
and K.-C. Hsu, Hadamard-type and Bullen-type inequalities for Lipschitzian
functions and their applications, Computers and Mathematics with Applications
(2012). doi:10.1016/j.camwa.2011.12.076].


title:
A hint to the origin of the extended emission in LAT GRBs: the relation
  between LAT luminosity and prompt energetics

abstract:
  We consider the 0.1-10 GeV rest frame light curves of 10 GRBs detected by LAT
and with known redshift. In all cases the emission persists after the prompt
has faded away. This extended emission decays in time as a power-law. The decay
slope is similar among different bursts, while the normalization spans more
than 2 decades. However, when the LAT luminosity is normalized to the 1 keV-10
MeV energetics of the prompt emission E_iso all light curves become consistent
with having the same normalization, i.e. they cluster. At each given time the
ratio between the LAT luminosity and the prompt energetics is narrowly
distributed. We argue that this result is expected in the external shock
scenario and it strengthens the interpretation of the GeV emission in terms of
radiation from external shocks. In this context, we derive limits on the
distribution of epsilon_e (the fraction of the shock energy that goes into
electrons) and eta (the efficiency of the mechanism producing the prompt).