title: Physical Layer Security in Downlink Multi-Antenna Cellular Networks

abstract:
  In this paper, we study physical layer security for the downlink of cellular
networks, where the confidential messages transmitted to each mobile user can
be eavesdropped by both (i) the other users in the same cell and (ii) the users
in the other cells. The locations of base stations and mobile users are modeled
as two independent two-dimensional Poisson point processes. Using the proposed
model, we analyze the secrecy rates achievable by regularized channel inversion
(RCI) precoding by performing a large-system analysis that combines tools from
stochastic geometry and random matrix theory. We obtain approximations for the
probability of secrecy outage and the mean secrecy rate, and characterize
regimes where RCI precoding achieves a nonzero secrecy rate. We find that
unlike isolated cells, the secrecy rate in a cellular network does not grow
monotonically with the transmit power, and the network tends to be in secrecy
outage if the transmit power grows unbounded. Furthermore, we show that there
is an optimal value for the base station deployment density that maximizes the
secrecy rate, and this value is a decreasing function of the signal-to-noise
ratio.


title: The Nyquist theorem for cellular sheaves

abstract:
  We develop a unified sampling theory based on sheaves and show that the
Shannon-Nyquist theorem is a cohomological consequence of an exact sequence of
sheaves. Our theory indicates that there are additional cohomological
obstructions for higher-dimensional sampling problems. Using these
obstructions, we also present conditions for perfect reconstruction of
piecewise linear functions on graphs, a collection of non-bandlimited functions
on topologically nontrivial domains.


title: Cosmicflows-2: The Data

abstract:
  Cosmicflows-2 is a compilation of distances and peculiar velocities for over
8000 galaxies. Numerically the largest contributions come from the
luminosity-linewidth correlation for spirals, the TFR, and the related
Fundamental Plane relation for E/S0 systems, but over 1000 distances are
contributed by methods that provide more accurate individual distances:
Cepheid, Tip of the Red Giant Branch, Surface Brightness Fluctuation, SNIa, and
several miscellaneous but accurate procedures. Our collaboration is making
important contributions to two of these inputs: Tip of the Red Giant Branch and
TFR. A large body of new distance material is presented. In addition, an effort
is made to assure that all the contributions, our own and those from the
literature, are on the same scale. Overall, the distances are found to be
compatible with a Hubble Constant H_0 = 74.4 +-3.0 km/s/Mpc. The great interest
going forward with this data set will be with velocity field studies.
Cosmicflows-2 is characterized by a great density and high accuracy of distance
measures locally, falling to sparse and coarse sampling extending to z=0.1.


title:
Graphene-enhanced, internal-magnetic-field-generated Rabi oscillations
  in metal-coated Si-SiO2 photoconductive detectors

abstract:
  We report our demonstration of Rabi oscillations in Si-SiO2-Al
photoconductive devices with nanosecond laser pulses of a few nJ at room
temperature without external magnetic fields. Zeeman splitting of spin quantum
states of dopants in silicon is achieved with internal magnetic fields produced
by the Al film under excitation of laser pulses. Rabi oscillation frequency is
15 MHz and 25 MHz when photocurrent direction is perpendicular and parallel,
respectively, to the propagation direction of linearly-polarized, 532-nm, 7-ns
laser pulses. Insertion of graphene buffer layer between Al and SiO2 provides a
three-fold enhancement in Rabi oscillation amplitude. This simple-structured,
low-cost device operated at room temperature should open a new avenue for
future spin-based electronics and optoelectronics.


title: Colax Reedy diagrams

abstract:
  We use a theory of colax Reedy diagrams to show that the category of Segal
M-precategories with fixed set of objects has a model structure for a symmetric
monoidal model category M = (M,\otimes,I). What is relevant here is when M is
monoidal for a non-cartesian product. The model structure is of Reedy style and
generalizes the Reedy model structure for classical Segal M-precategories when
M is monoidal for the cartesian product. The techniques we use also generalize
the Reedy model structure for classical Reedy diagrams.


title: A calculus on lax functors

abstract:
  We verify that Kelly's constructions of the internal Hom for enriched
categories extends naturally to lax functors taking their values in a symmetric
monoidal category. Our motivation is to set up a `calculus on lax functors'
that will host the theory of weakly enriched categories that are defined by lax
diagrams.


title:
Solving the heat equation in piecewise-homogeneous anisotropic media
  using the multidimensional Fourier transforms

abstract:
  Multidimensional integral transformations with non-separated variables for
problems with discontinuous coefficients are constructed in this work. The
coefficient discontinuities focused on the of parallel hyperplanes. In this
work explicit formulas for the kernels in the case of ideal coupling conditions
are obtained; the basic identity of the integral transform is proved; technique
of integral transforms is developed


title: Toward a strictification theorem for co-Segal categories

abstract:
  We show that for a monoidal model category $\M=(\ul{M}, \otimes, I)$, certain
co-Segal $\M$-categories are equivalent to strict ones.


title:
A Posteriori Error Estimates of Krylov Subspace Approximations to Matrix
  Functions

abstract:
  Krylov subspace methods for approximating a matrix function $f(A)$ times a
vector $v$ are analyzed in this paper. For the Arnoldi approximation to
$e^{-\tau A}v$, two reliable a posteriori error estimates are derived from the
new bounds and generalized error expansion we establish. One of them is similar
to the residual norm of an approximate solution of the linear system, and the
other one is determined critically by the first term of the error expansion of
the Arnoldi approximation to $e^{-\tau A}v$ due to Saad. We prove that each of
the two estimates is reliable to measure the true error norm, and the second
one theoretically justifies an empirical claim by Saad. In the paper, by
introducing certain functions $\phi_k(z)$ defined recursively by the given
function $f(z)$ for certain nodes, we obtain the error expansion of the
Krylov-like approximation for $f(z)$ sufficiently smooth, which generalizes
Saad's result on the Arnoldi approximation to $e^{-\tau A}v$. Similarly, it is
shown that the first term of the generalized error expansion can be used as a
reliable a posteriori estimate for the Krylov-like approximation to some other
matrix functions times $v$. Numerical examples are reported to demonstrate the
effectiveness of the a posteriori error estimates for the Krylov-like
approximations to $e^{-\tau A}v$, $\cos(A)v$ and $\sin(A)v$.


title: Multiple Network Alignment on Quantum Computers

abstract:
  Comparative analyses of graph structured datasets underly diverse problems.
Examples of these problems include identification of conserved functional
components (biochemical interactions) across species, structural similarity of
large biomolecules, and recurring patterns of interactions in social networks.
A large class of such analyses methods quantify the topological similarity of
nodes across networks. The resulting correspondence of nodes across networks,
also called node alignment, can be used to identify invariant subgraphs across
the input graphs.
  Given $k$ graphs as input, alignment algorithms use topological information
to assign a similarity score to each $k$-tuple of nodes, with elements (nodes)
drawn from each of the input graphs. Nodes are considered similar if their
neighbors are also similar. An alternate, equivalent view of these network
alignment algorithms is to consider the Kronecker product of the input graphs,
and to identify high-ranked nodes in the Kronecker product graph. Conventional
methods such as PageRank and HITS (Hypertext Induced Topic Selection) can be
used for this purpose. These methods typically require computation of the
principal eigenvector of a suitably modified Kronecker product matrix of the
input graphs. We adopt this alternate view of the problem to address the
problem of multiple network alignment. Using the phase estimation algorithm, we
show that the multiple network alignment problem can be efficiently solved on
quantum computers. We characterize the accuracy and performance of our method,
and show that it can deliver exponential speedups over conventional
(non-quantum) methods.


title: Dispersion measure variations in a sample of 168 pulsars

abstract:
  We analyse dispersion measure (DM) variations in six years of radio
observations of more than 160 young pulsars, all gamma ray candidates for the
Fermi gamma ray telescope mostly located close to the Galactic plane. DMs were
fit across 256 MHz of bandwidth for observations centred at 1.4 GHz and across
three frequencies -- 0.7 GHz, 1.4 GHz, and 3.1 GHz -- where multifrequency
observations were available. Changes in dispersion measure, dDM/dt, were
calculated using a weighted linear fit across all epochs of available DMs. DM
variations were detected at a 3\sigma level in 11 pulsars, four of which were
above 5\sigma: PSRs J0835-4510, J0908-4913, J1824-1945, and J1833-0827. We find
that after 28 years of gradual decline, the DM of PSR J0835-4510 is now
increasing. The magnitude of variations in three of the four (PSRs J0835-4510,
J0908-4913, and J1833-0827) are above what models would predict for an ISM
dominated by Kolmogorov turbulence. We attribute this excess as likely due to
the pulsar's local environment - the supernova remnants near PSRs J0835-4510
and J1833-0827 and the pulsar wind nebula around PSR J0908-4913. Upper limits
were determined for all pulsars without detectable values of dDM/dt, most
limits were found to lie above the levels of variations predicted by ISM
theory. We find our results to be consistent with scattering estimates from the
NE2001 model along these lines of sight.


title: Incipient infinite cluster in 2D Ising percolation

abstract:
  We consider the percolation problem in the high-temperature Ising model on
the two-dimensional square lattice at or near critical external fields. The
incipient infinite cluster (IIC) measure in the sense of Kesten is constructed.
As a consequence, we can obtain some geometric properties of IIC. The result
holds also for the triangular lattice.


title: Universal Polar Codes

abstract:
  Polar codes, invented by Arikan in 2009, are known to achieve the capacity of
any binary-input memoryless output-symmetric channel. One of the few drawbacks
of the original polar code construction is that it is not universal. This means
that the code has to be tailored to the channel if we want to transmit close to
capacity.
  We present two "polar-like" schemes which are capable of achieving the
compound capacity of the whole class of binary-input memoryless
output-symmetric channels with low complexity.
  Roughly speaking, for the first scheme we stack up $N$ polar blocks of length
$N$ on top of each other but shift them with respect to each other so that they
form a "staircase." Coding then across the columns of this staircase with a
standard Reed-Solomon code, we can achieve the compound capacity using a
standard successive decoder to process the rows (the polar codes) and in
addition a standard Reed-Solomon erasure decoder to process the columns.
Compared to standard polar codes this scheme has essentially the same
complexity per bit but a block length which is larger by a factor $O(N
\log_2(N)/\epsilon)$, where $\epsilon$ is the gap to capacity.
  For the second scheme we first show how to construct a true polar code which
achieves the compound capacity for a finite number of channels. We achieve this
by introducing special "polarization" steps which "align" the good indices for
the various channels. We then show how to exploit the compactness of the space
of binary-input memoryless output-symmetric channels to reduce the compound
capacity problem for this class to a compound capacity problem for a finite set
of channels. This scheme is similar in spirit to standard polar codes, but the
price for universality is a considerably larger blocklength.
  We close with what we consider to be some interesting open problems.


title: An algorithm for computing the universal Gr\"obner Basis of graph ideals

abstract:
  The universal Gr\"obner basis of an ideal is a Gr\"obner basis with respect
to all term orders simultaneously. The aim of this paper is to present an
algorithmic approach to compute the universal Gr\"obner basis for the toric
ideal corresponding to an undirected graph, based on the theoretically
knowledge of this set and on a recent, efficiently computable algorithmic
characterization of the Graver basis of the ideal.


title: Evidence for a pion condensate formation in pp interactions at U-70

abstract:
  A high multiplicity study (project Thermalization, experiment E-190) is
carried out on U-70 accelerator at IHEP (Protvino, Russia). This project is
aimed at searching for collective phenomena. It is known that pions are mainly
produced at the 50 GeV-proton beam accelerator. Their mean energy decreases
while multiplicity increasing. Bose-Einstein condensate (BEC) can be formed in
this system. The theoretical and experimental studies of BEC have been
performed since 70es. Within the framework of an ideal pion gas model M.
Gorenstein and V. Begun have shown that sharp growth of fluctuations of the
neutral pion number will be a signal of BEC formation with the increase of the
total multiplicity (neutral and charged particle sum). SVD-2 Collaboration
(JINR, IHEP and SINP MSU) investigated fluctuations of the neutral pion number
in pp interactions at 50 GeV/c incident beam on U-70 versus the total
multiplicity and has revealed noticeable growth of the scaled variance with the
total multiplicity increase. The growth of these fluctuations reaches more than
7 standard deviations for the scaled variance at the total multiplicity about
30 pions as opposed to the tendency for the simulated events. This growth has
been observed both in the registered photons and restored neutral pions.


title:
Diffusion Least Mean P-Power Algorithms for Distributed Estimation in
  Alpha-Stable Noise Environments

abstract:
  We propose a diffusion least mean p-power (LMP) algorithm for distributed
estimation in alpha stable noise environments, which is one of the widely used
models that appears in various environments. Compared with the diffusion least
mean squares (LMS) algorithm, better performance is obtained for the diffusion
LMP methods when the noise is with alpha-stable distribution.


title: Canonical forms for perturbations of the harmonic oscillator

abstract:
  We consider a class of perturbations of the 2D harmonic oscillator, and of
some other dynamical systems, which we show are isomorphic to a function of a
toric system (a Birkhoff canonical form). We show that for such systems there
exists a quantum normal form as well, which is determined by spectral data.


title: Parallel field magnetoresistance in topological insulator thin films

abstract:
  We report that the finite thickness of three-dimensional topological
insulator (TI) thin films produces an observable magnetoresistance (MR) in
phase coherent transport in parallel magnetic fields. The MR data of Bi2Se3 and
(Bi,Sb)2Te3 thin films are compared with existing theoretical models of
parallel field magnetotransport. We conclude that the TI thin films bring
parallel field transport into a unique regime in which the coupling of surface
states to bulk and to opposite surfaces is indispensable for understanding the
observed MR. The {\beta} parameter extracted from parallel field MR can in
principle provide a figure of merit for searching TI compounds with more
insulating bulk than existing materials.


title: Additive and product properties of Drazin inverses of elements in a ring

abstract:
  We study the Drazin inverses of the sum and product of two elements in a
ring. For Drazin invertible elements $a$ and $b$ such that $a^2b=aba$ and
$b^2a=bab$, it is shown that $ab$ is Drazin invertible and that $a+b$ is Drazin
invertible if and only if $1+a^Db$ is Drazin invertible. Moreover, the formulae
of $(ab)^D$ and $(a+b)^D$ are presented. Thus, a generalization of the main
result of Zhuang, Chen et al. (Linear Multilinear Algebra 60 (2012) 903-910) is
given.


title:
NMR Investigation of the Diluted Magnetic Semiconductor Li(Zn1-xMnx)P (x
  = 0.1)

abstract:
  We employ NMR techniques to investigate the nature of Mn spins in the I-II-V
diluted magnetic semiconductor Li(Zn1-xMnx)P (x = 0.1, Curie temperature Tc =
25 K). We successfully identify the 7Li NMR signals arising from the Li sites
adjacent to Mn2+, and probe the static and dynamic properties of Mn spins. From
the NMR spin-lattice relaxation data, we show that the Mn spin-spin
interactions extend over many unit cells.


title: Competitive MAC under Adversarial SINR

abstract:
  This paper considers the problem of how to efficiently share a wireless
medium which is subject to harsh external interference or even jamming. While
this problem has already been studied intensively for simplistic single-hop or
unit disk graph models, we make a leap forward and study MAC protocols for the
SINR interference model (a.k.a. the physical model).
  We make two contributions. First, we introduce a new adversarial SINR model
which captures a wide range of interference phenomena. Concretely, we consider
a powerful, adaptive adversary which can jam nodes at arbitrary times and which
is only limited by some energy budget. The second contribution of this paper is
a distributed MAC protocol which provably achieves a constant competitive
throughput in this environment: we show that, with high probability, the
protocol ensures that a constant fraction of the non-blocked time periods is
used for successful transmissions.


title:
Additive property of pseudo Drazin inverse of elements in a Banach
  algebra

abstract:
  We study properties of pseudo Drazin inverse in a Banach algebra with unity
1. If $ab=ba$ and $a,b$ are pseudo Drazin invertible, we prove that $a+b$ is
pseudo Drazin invertible if and only if $1+a^\ddag b$ is pseudo Drazin
invertible. Moreover, the formula of $(a+b)^\ddag$ is presented . When the
commutative condition is weaken to $ab=\lambda ba ~(\lambda \neq 0)$, we also
show that $a-b$ is pseudo Drazin invertible if and only if
$aa^\ddag(a-b)bb^\ddag$ is pseudo Drazin invertible.


title: Through Wall People Localization Exploiting Radio Windows

abstract:
  We introduce and investigate the ability of an attacker to surreptitiously
use an otherwise secure wireless network to detect moving people through walls,
in an area in which people expect their location to be private. We call this
attack on location privacy of people an "exploiting radio windows" (ERW)
attack. We design and implement the ERW attack methodology for through wall
people localization that relies on reliably detecting when people cross the
link lines by using physical layer measurements between the legitimate
transmitters and the attack receivers. We also develop a method to estimate the
direction of movement of a person from the sequence of link lines crossed
during a short time interval. Additionally, we describe how an attacker may
estimate any artificial changes in transmit power (used as a countermeasure),
compensate for these power changes using measurements from sufficient number of
links, and still detect line crossings. We implement our methodology on WiFi
and ZigBee nodes and experimentally evaluate the ERW attack by monitoring
people movements through walls in two real-world settings. We find that our
methods achieve very high accuracy in detecting line crossings and determining
direction of motion.


title: Divided difference operators on polytopes

abstract:
  We define convex-geometric counterparts of divided difference (or Demazure)
operators from the Schubert calculus and representation theory. These operators
are used to construct inductively polytopes that capture Demazure characters of
representations of reductive groups. In particular, Gelfand-Zetlin polytopes
and twisted cubes of Grossberg-Karshon are obtained in a uniform way.


title: Categorification of Seidel's representation

abstract:
  Two natural symplectic constructions, the Lagrangian suspension and Seidel's
quantum representation of the fundamental group of the group of Hamiltonian
diffeomorphisms, Ham(M), with (M,\omega) a monotone symplectic manifold, admit
categorifications as actions of the fundamental groupoid \Pi(Ham(M)) on a
cobordism category recently introduced in \cite{Bi-Co:cob2} and, respectively,
on a monotone variant of the derived Fukaya category. We show that the functor
constructed in \cite{Bi-Co:cob2} that maps the cobordism category to the
derived Fukaya category is equivariant with respect to these actions.


title: Spherical multiple flags

abstract:
  For a reductive group G, the products of projective rational varieties
homogeneous under G that are spherical for G have been classified by
Stembridge. We consider the B-orbit closures in these spherical varieties and
prove that under some mild restrictions they are normal, Cohen-Macaulay and
have a rational resolution.


title:
Molecular Density Functional Theory of Water describing Hydrophobicity
  at Short and Long Length Scales

abstract:
  We present an extension of our recently introduced molecular density
functional theory of water [G. Jeanmairet et al., J. Phys. Chem. Lett. 4, 619,
2013] to the solvation of hydrophobic solutes of various sizes, going from
angstroms to nanometers. The theory is based on the quadratic expansion of the
excess free energy in terms of two classical density fields, the particle
density and the multipolar polarization density. Its implementation requires as
input a molecular model of water and three measurable bulk properties, namely
the structure factor and the k-dependent longitudinal and transverse dielectric
susceptibilities. The fine three-dimensional water structure around small
hydrophobic molecules is found to be well reproduced. In contrast the computed
solvation free-energies appear overestimated and do not exhibit the correct
qualitative behavior when the hydrophobic solute is grown in size. These
shortcomings are corrected, in the spirit of the Lum-Chandler-Weeks theory, by
complementing the functional with a truncated hard-sphere functional acting
beyond quadratic order in density. It makes the resulting functional compatible
with the Van-der-Waals theory of liquid-vapor coexistence at long range.
Compared to available molecular simulations, the approach yields reasonable
solvation structure and free energy of hard or soft spheres of increasing size,
with a correct qualitative transition from a volume-driven to a surface-driven
regime at the nanometer scale.


title:
Analysis and Modeling of Network Connectivity in Routing Protocols for
  MANETs and VANETs

abstract:
  In this paper, a framework is presented for node distribution with respect to
density, network connectivity and communication time. According to modeled
framework we evaluate and compare the performance of three routing protocols;
Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR) and
Fisheye State Routing (FSR) in MANETs and VANETs using two Mac-layer protocols;
802.11 and 802.11p. We have further modified these protocols by changing their
routing information exchange intervals; MOD AODV, MOD DSR and MOD FSR. A
comprehensive simulation work is performed in NS-2 for the comparison of these
routing protocols for varying mobilities and scalabilities of nodes. To
evaluate their efficiency; throughput, End-to-End Delay (E2ED) and Normalized
Routing Load (NRL) of these protocols are taken into account as performance
parameters. After extensive simulations, we observe that AODV outperforms both
with MANETs and VANETs.


title: Generalized Conley-Zehnder index

abstract:
  The Conley-Zehnder index associates an integer to any continuous path of
symplectic matrices starting from the identity and ending at a matrix which
does not admit 1 as an eigenvalue. We give new ways to compute this index.
Robbin and Salamon define a generalization of the Conley-Zehnder index for any
continuous path of symplectic matrices; this generalization is half integer
valued. It is based on a Maslov-type index that they define for a continuous
path of Lagrangians in a symplectic vector space $(W,\bar{\Omega})$, having
chosen a given reference Lagrangian $V$. Paths of symplectic endomorphisms of
$(\R^{2n},\Omega_0)$ are viewed as paths of Lagrangians defined by their graphs
in $(W=\R^{2n}\oplus \R^{2n},\bar{\Omega}=\Omega_0\oplus -\Omega_0)$ and the
reference Lagrangian is the diagonal. Robbin and Salamon give properties of
this generalized Conley-Zehnder index and an explicit formula when the path has
only regular crossings. We give here an axiomatic characterization of this
generalized Conley-Zehnder index. We also give an explicit way to compute it
for any continuous path of symplectic matrices.


title:
Modeling Probability of Path Loss for DSDV, OLSR and DYMO above 802.11
  and 802.11p

abstract:
  This paper presents path loss model along with framework for probability
distribution function for VANETs. Furthermore, we simulate three routing
protocols Destination Sequenced Distance Vector (DSDV), Optimized Link State
Routing (OLSR) and Dynamic MANET On-demand (DYMO) in NS-2 to evaluate and
compare their performance using two Mac-layer Protocols 802.11 and 802.11p. A
novel approach of this work is modifications in existing parameters to achieve
high efficiency. After extensive simulations, we observe that DSDV out performs
with 802.11p while DYMO gives best performance with 802.11.


title:
Non-Invasive Induction Link Model for Implantable Biomedical
  Microsystems: Pacemaker to Monitor Arrhythmic Patients in Body Area Networks

abstract:
  In this paper, a non-invasive inductive link model for an Implantable
Biomedical Microsystems (IBMs) such as, a pacemaker to monitor Arrhythmic
Patients (APs) in Body Area Networks (BANs) is proposed. The model acts as a
driving source to keep the batteries charged, inside a device called,
pacemaker. The device monitors any drift from natural human heart beats, a
condition of arrythmia and also in turn, produces electrical pulses that create
forced rhythms that, matches with the original normal heart rhythms. It
constantly sends a medical report to the health center to keep the medical
personnel aware of the patient's conditions and let them handle any critical
condition, before it actually happens. Two equivalent models are compared by
carrying the simulations, based on the parameters of voltage gain and link
efficiency. Results depict that the series tuned primary and parallel tuned
secondary circuit achieves the best results for both the parameters, keeping in
view the constraint of coupling co-efficient (k), which should be less than a
value \emph{0.45} as, desirable for the safety of body tissues.


title: Measuring Fatigue of Soldiers in Wireless Body Area Sensor Networks

abstract:
  Wireless Body Area Sensor Networks (WBASNs) consist of on-body or in-body
sensors placed on human body for health monitoring. Energy conservation of
these sensors, while guaranteeing a required level of performance, is a
challenging task. Energy efficient routing schemes are designed for the
longevity of network lifetime. In this paper, we propose a routing protocol for
measuring fatigue of a soldier. Three sensors are attached to soldier's body
that monitor specific parameters. Our proposed protocol is an event driven
protocol and takes three scenarios for measuring the fatigue of a soldier. We
evaluate our proposed work in terms of network lifetime, throughput, remaining
energy of sensors and fatigue of a soldier.


title:
Formation of metallic magnetic clusters in a Kondo-lattice metal:
  Evidence from an optical study

abstract:
  Magnetic materials are usually divided into two classes: those with localised
magnetic moments, and those with itinerant charge carriers. We present a
comprehensive experimental (spectroscopic ellipsomerty) and theoretical study
to demonstrate that these two types of magnetism do not only coexist but
complement each other in the Kondo-lattice metal, Tb2PdSi3. In this material
the itinerant charge carriers interact with large localised magnetic moments of
Tb(4f) states, forming complex magnetic lattices at low temperatures, which we
associate with self-organisation of magnetic clusters. The formation of
magnetic clusters results in low-energy optical spectral weight shifts, which
correspond to opening of the pseudogap in the conduction band of the itinerant
charge carriers and development of the low- and high-spin intersite electronic
transitions. This phenomenon, driven by self-trapping of electrons by magnetic
fluctuations, could be common in correlated metals, including besides
Kondo-lattice metals, Fe-based and cuprate superconductors.


title: Extracting information from the signature of a financial data stream

abstract:
  Market events such as order placement and order cancellation are examples of
the complex and substantial flow of data that surrounds a modern financial
engineer. New mathematical techniques, developed to describe the interactions
of complex oscillatory systems (known as the theory of rough paths) provides
new tools for analysing and describing these data streams and extracting the
vital information. In this paper we illustrate how a very small number of
coefficients obtained from the signature of financial data can be sufficient to
classify this data for subtle underlying features and make useful predictions.
  This paper presents financial examples in which we learn from data and then
proceed to classify fresh streams. The classification is based on features of
streams that are specified through the coordinates of the signature of the
path. At a mathematical level the signature is a faithful transform of a
multidimensional time series. (Ben Hambly and Terry Lyons \cite{uniqueSig}),
Hao Ni and Terry Lyons \cite{NiLyons} introduced the possibility of its use to
understand financial data and pointed to the potential this approach has for
machine learning and prediction.
  We evaluate and refine these theoretical suggestions against practical
examples of interest and present a few motivating experiments which demonstrate
information the signature can easily capture in a non-parametric way avoiding
traditional statistical modelling of the data. In the first experiment we
identify atypical market behaviour across standard 30-minute time buckets
sampled from the WTI crude oil future market (NYMEX). The second and third
experiments aim to characterise the market "impact" of and distinguish between
parent orders generated by two different trade execution algorithms on the FTSE
100 Index futures market listed on NYSE Liffe.


title:
AM-DisCNT: Angular Multi-hop DIStance based Circular Network
  Transmission Protocol for WSNs

abstract:
  The nodes in wireless sensor networks (WSNs) contain limited energy
resources, which are needed to transmit data to base station (BS). Routing
protocols are designed to reduce the energy consumption. Clustering algorithms
are best in this aspect. Such clustering algorithms increase the stability and
lifetime of the network. However, every routing protocol is not suitable for
heterogeneous environments. AM-DisCNT is proposed and evaluated as a new energy
efficient protocol for wireless sensor networks. AM-DisCNT uses circular
deployment for even consumption of energy in entire wireless sensor network.
Cluster-head selection is on the basis of energy. Highest energy node becomes
CH for that round. Energy is again compared in the next round to check the
highest energy node of that round. The simulation results show that AM-DisCNT
performs better than the existing heterogeneous protocols on the basis of
network lifetime, throughput and stability of the system.


title:
Tracking down localized modes in PT-symmetric Hamiltonians under the
  influence of a competing nonlinearity

abstract:
  The relevance of parity and time reversal (PT)-symmetric structures in
optical systems is known for sometime with the correspondence existing between
the Schrodinger equation and the paraxial equation of diffraction where the
time parameter represents the propagating distance and the refractive index
acts as the complex potential. In this paper, we systematically analyze a
normalized form of the nonlinear Schrodinger system with two new families of
PT-symmetric potentials in the presence of competing nonlinearities. We
generate a class of localized eigenmodes and carry out a linear stability
analysis on the solutions. In particular, we find an interesting feature of
bifurcation charaterized by the parameter of perturbative growth rate passing
through zero where a transition to imaginary eigenvalues occurs.


title:
Theory of the multiphoton cascade transitions with two photon links:
  comparison of Quantum Electrodynamical and Quantum Mechanical approaches

abstract:
  QED theory of multiphoton cascade transitions in atoms and ions is developed.
In particular the $ 3s\rightarrow1s+2\gamma $, $ 4s\rightarrow1s+2\gamma $ and
$ 3p\rightarrow1s+3\gamma $ processes are considered. Two different approaches
(Quantum Electrodynamical and phenomenological Quantum Mechanical) are applied.


title:
Filament eruption in association with rotational motion near the
  filament footpoints

abstract:
  The active region magnetic field surrounding the filament plays an important
role in filament formation, their evolution and disruption. We investigated a
filament eruption that occurred in southern hemisphere of the Sun on July 08,
2011 using AIA and HMI data. The filament was located in a region close to the
active region NOAA 11247 with its West-most footpoint anchored in the negative
polarity plage region and the East-most in the positive polarity plage region.
During observations, the magnetic flux was emerging in the active region and
also in the plage regions. The flux emergence was stopped in West-most
footpoint of the plage region about an hour before the filament eruption. A
converging motion was also observed for many hours in the Western footpoint of
the filament. The filament had left-handed twist and the net injected magnetic
helicity was positive in both footpoints. Both sign of magnetic helicity were
observed in the Western footpoint of the filament where the eruption has
initiated. Further, an anti-clockwise rotational motion was observed in both
the footpoints just after the onset of filament eruption which lasted for 6 min
during the eruption process. The emerging flux, converging motion and injection
of opposite magnetic helicity could be responsible for destabilizing of the
Western footpoint of the filament leading to eruption. The torque imbalance
between the expanded portion of the flux tube and the photosphere may have
caused the rotation in the footpoint region which changed the trend in the
injected magnetic helicity after the filament eruption.


title:
Access Point Density and Bandwidth Partitioning in Ultra Dense Wireless
  Networks

abstract:
  This paper examines the impact of system parameters such as access point
density and bandwidth partitioning on the performance of randomly deployed,
interference-limited, dense wireless networks. While much progress has been
achieved in analyzing randomly deployed networks via tools from stochastic
geometry, most existing works either assume a very large user density compared
to that of access points which does not hold in a dense network, and/or
consider only the user signal-to-interference-ratio as the system figure of
merit which provides only partial insight on user rate, as the effect of
multiple access is ignored. In this paper, the user rate distribution is
obtained analytically, taking into account the effects of multiple access as
well as the SIR outage. It is shown that user rate outage probability is
dependent on the number of bandwidth partitions (subchannels) and the way they
are utilized by the multiple access scheme. The optimal number of partitions is
lower bounded for the case of large access point density. In addition, an upper
bound of the minimum access point density required to provide an asymptotically
small rate outage probability is provided in closed form.


title:
Torus quantum vortex knots in the Gross-Pitaevskii model for
  Bose-Einstein condensates

abstract:
  We examine on the static and dynamical properties of quantum knots in a
Bose-Einstein condensate. In particular, we consider the Gross-Pitaevskii model
and revise a technique to construct ab initio the condensate wave-function of a
generic torus knot. After analysing its excitation energy, we study its
dynamics relating the topological parameter to its translational velocity and
characteristic size. We also investigate the breaking mechanisms of non
shape-preserving torus knots confirming an evidence of universal decaying
behaviour previously observed.

categories: cond-mat.quant-gas math.GT nlin.PS physics.flu-dyn


title:
Spectral Properties of the Wilson Dirac Operator and random matrix
  theory

abstract:
  Random Matrix Theory has been successfully applied to lattice Quantum
Chromodynamics. In particular, a great deal of progress has been made on the
understanding, numerically as well as analytically, of the spectral properties
of the Wilson Dirac operator. In this paper, we study the infra-red spectrum of
the Wilson Dirac operator via Random Matrix Theory including the three leading
order $a^2$ correction terms that appear in the corresponding chiral
Lagrangian. A derivation of the joint probability density of the eigenvalues is
presented. This result is used to calculate the density of the complex
eigenvalues, the density of the real eigenvalues and the distribution of the
chiralities over the real eigenvalues. A detailed discussion of these
quantities shows how each low energy constant affects the spectrum. Especially
we consider the limit of small and large (which is almost the mean field limit)
lattice spacing. Comparisons with Monte Carlo simulations of the Random Matrix
Theory show a perfect agreement with the analytical predictions. Furthermore we
present some quantities which can be easily used for comparison of lattice data
and the analytical results.


title: Fuchsian codes for AWGN channels

abstract:
  We develop a new transmission scheme for additive white Gaussian noisy (AWGN)
single-input single-output (SISO) channels without fading based on arithmetic
Fuchsian groups. The properly discontinuous character of the action of these
groups on the upper half-plane translates into logarithmic decoding complexity.


title:
The random integral representation hypothesis revisited : new classes of
  s-selfdecomposable laws

abstract:
  For $\,0<\alpha\le \infty$, new subclasses $\,\mathcal{U}^{<\alpha>}$ of the
class $\,\mathcal{U}$, of s-selfdecomposable probability measures, are studied.
They are described by random integrals, by their characteristic functions and
their L\'evy spectral measures. Also their relations with the classical L\'evy
class $L$ of selfdecomposable distributions are investigated.


title:
Distribution function of charge carriers in electron-phonon systems with
  spontaneously broken translational symmetry and 'vertical dispersion' in
  ARPES spectra of cuprates

abstract:
  We show that spontaneous breaking of the translational symmetry (SBTS) of
strongly interacting electron and phonon fields acknowledged in lightly doped
cuprates to interpret broad bands in their ARPES and optical conductivity
spectra influences the carrier distribution function as charge carrier momentum
is no longer certain. We develop appropriate distribution and use it to
calculate the carrier concentration in different states in essentially doped
systems with SBTS. This allows studying doping and temperature evolution of
ARPES spectra of such systems. We reveal that at increasing both temperature or
doping polarons concede dominance to bipolarons that results in a shift of the
broad band maximum to higher binding energy as it occurs in ARPES spectra of
cuprates. At further doping delocalized carriers appear and coexist with
bipolarons. We show that intimate property of systems with SBTS is partition of
the momentum space between autolocalized and delocalized carriers caused by
Pauli exclusion rule. We demonstrate that in ARPES spectra such partition
manifests itself as `vertical dispersion` or waterfalls universally observed in
all the cuprates at essential doping and in undoped parent compounds. Thus,
studying the carriers distribution in systems where electron-phonon interaction
breaks the translation symmetry leads simultaneously to both types of
waterfalls observed in significantly doped and undoped cuprates. The article
also represents the methods developed to calculate the band in ARPES spectrum
caused by bipolaron photodissociation and the bipolaron binding energy and
radius using coherent states for the phonon field characterization.


title: Theory of Absorption Induced Transparency

abstract:
  Recent experiments (Angew. Chem. Int. Ed. 50, 2085 (2011)) have demonstrated
that the optical transmission through an array of subwavelength holes in a
metal film can be enhanced by the intentional presence of dyes in the system.
As the transmission maxima occurs spectrally close to the absorption resonances
of the dyes, this phenomenon was christened Absorption Induced Transparency.
Here, a theoretical study on Absorption Induced Transparency is presented. The
results show that the appearance of transmission maxima requires that the
absorbent fills the holes and that it occurs also for single holes.
Furthermore, it is shown that the transmission process is non-resonant, being
composed by a sequential passage of the EM field through the hole. Finally, the
physical origin of the phenomenon is demonstrated to be non-plasmonic, which
implies that Absorption Induced Transparency should also occur at the infrared
or Terahertz frequency regimes.


title: Leptonic asymmetry in ttbar production at CDF

abstract:
  The leptonic asymmetry in semileptonic ttbar decays is measured with the CDF
detector using the full Tevatron Run II dataset, which corresponds to 9.4 fb^-1
of integrated luminosity. The measured asymmetry is extrapolated to the full
kinematic range and the measured value of A_FB^lep = 0.094^+0.032_-0.029 is
compared to the NLO prediction A_FB^lep = 0.038 +/- 0.003.


title: On the error estimate of gradient inclusions

abstract:
  The numerical analysis of gradient inclusions in a compact subset of $2\times
2$ diagonal matrices is studied. Assuming that the boundary conditions are
reached after a finite number of laminations and using piecewise linear finite
elements, we give a general error estimate in terms of the number of
laminations and the mesh size. This is achieved by reduction results from
compact to finite case.


title: Heavy-quark production in deep-inelastic scattering

abstract:
  We report recent experimental and theoretical progress concerning the
heavy-quark electro-production in the context of the ABM11 parton distribution
function (PDF) fit. In the updated ABM11 analysis, including the recent
combined HERA charm data, the MSbar-values of the c-quark mass m_c(m_c)=1.24 +-
0.03 (exp)\,^{+0.03}_{-0.02}(scale)\,^{+0.00}_{-0.07} (th) and m_c(m_c)=1.15\,
+- 0.04 (exp)\,^{+0.04}_{-0.00} (scale) are determined at NNLO and NLO,
respectively. The values of m_c obtained are compared to other determinations
including the ones based on the various variable-flavor-number (VFN) scheme
prescriptions.The VFN scheme uncertainties related to the matching of the
4(5)-flavor PDFs with the 3(4)-flavor ones are discussed.


title: The predecessor-existence problem for k-reversible processes

abstract:
  For k>=1, we consider the graph dynamical system known as a k-reversible
process. In such process, each vertex in the graph has one of two possible
states at each discrete time. Each vertex changes its state between the present
time and the next if and only if it currently has at least k neighbors in a
state different than its own. Given a k-reversible process and a configuration
of states assigned to the vertices, the Predecessor Existence problem consists
of determining whether this configuration can be generated by the process from
another configuration within exactly one time step. We can also extend the
problem by asking for the number of configurations from which a given
configuration is reachable within one time step. Predecessor Existence can be
solved in polynomial time for k=1, but for k>1 we show that it is NP-complete.
When the graph in question is a tree we show how to solve it in O(n) time and
how to count the number of predecessor configurations in O(n^2) time. We also
solve Predecessor Existence efficiently for the specific case of 2-reversible
processes when the maximum degree of a vertex in the graph is no greater than
3. For this case we present an algorithm that runs in O(n) time.


title: String Theory and Emergent AdS Geometry in Higher Spin Field Theories

abstract:
  We analyze the Weyl invariance constraints on higher spin vertex operators in
open superstring theory describing massless higher spin gauge field excitations
in d-dimensional space-time. We show that these constraints lead to low-energy
equations of motion for higher spin fields in AdS space, with the leading order
beta-function for the higher spin fields producing Fronsdal's operator in
$AdS_{d+1}$, despite that the higher spin vertex operators are originally
defined in flat background. The correspondence between the $\beta$-function in
string theory and $AdS_{d+1}$ Fronsdal operators in space-time is found to be
exact for $d=4$, while for other space-time dimensions it requires
modifications of manifest expressions for the higher spin vertex operators.
  We argue that the correspondence considered in this paper is the leading
order of more general isomorphism between Vasiliev's equations and equations of
motion of extended open string field theory (OSFT), generalized to include the
higher spin operators.


title: The Power of Spreadsheet Computations

abstract:
  We investigate the expressive power of spreadsheets. We consider spreadsheets
which contain only formulas, and assume that they are small templates, which
can be filled to a larger area of the grid to process input data of variable
size. Therefore we can compare them to well-known machine models of
computation. We consider a number of classes of spreadsheets defined by
restrictions on their reference structure. Two of the classes correspond
closely to parallel complexity classes: we prove a direct correspondence
between the dimensions of the spreadsheet and amount of hardware and time used
by a parallel computer to compute the same function. As a tool, we produce
spreadsheets which are universal in these classes, i.e. can emulate any other
spreadsheet from them. In other cases we implement in the spreadsheets in
question instances of a polynomial-time complete problem, which indicates that
the the spreadsheets are unlikely to have efficient parallel evaluation
algorithms. Thus we get a picture how the computational power of spreadsheets
depends on their dimensions and structure of references.


title: Magnetically tunable Feshbach resonances in Li + Yb($^3P_J$)

abstract:
  We have investigated magnetically tunable Feshbach resonances arising from
the interaction of Li($^2S$) with metastable Yb($^3P_2$) and ($^3P_0$). For
Yb($^3P_2$), all the resonance features are strongly suppressed by inelastic
collisions that produce Yb in its lower-lying $^3P_1$ and $^3P_0$ states. For
Yb($^3P_0$), sharp resonances exist but they are extremely narrow (widths less
than 1 mG).


title: Sampling-Based Temporal Logic Path Planning

abstract:
  In this paper, we propose a sampling-based motion planning algorithm that
finds an infinite path satisfying a Linear Temporal Logic (LTL) formula over a
set of properties satisfied by some regions in a given environment. The
algorithm has three main features. First, it is incremental, in the sense that
the procedure for finding a satisfying path at each iteration scales only with
the number of new samples generated at that iteration. Second, the underlying
graph is sparse, which guarantees the low complexity of the overall method.
Third, it is probabilistically complete. Examples illustrating the usefulness
and the performance of the method are included.


title: Tune-out wavelengths for the alkaline earth atoms

abstract:
  The lowest 3 tune-out wavelengths of the four alkaline-earth atoms, Be, Mg,
Ca and Sr are determined from tabulations of matrix elements produced from
large first principles calculations. The tune-out wavelengths are located near
the wavelengths for $^3P^o_1$ and $^1P^o_1$ excitations. The measurement of the
tune-out wavelengths could be used to establish a quantitative relationship
between the oscillator strength of the transition leading to existence of the
tune-out wavelength and the dynamic polarizability of the atom at the tune-out
frequency. The longest tune-out wavelengths for Be, Mg, Ca, Sr, Ba and Yb are
454.9813 nm, 457.2372 nm, 657.446 nm, 689.200 nm, 788.875 nm and 553.00 nm
respectively.


title:
Magnetic catalysis effect in (2+1)-dimensional Gross--Neveu model with
  Zeeman interaction

abstract:
  Magnetic catalysis of the chiral symmetry breaking and other magnetic
properties of the (2+1)-dimensional Gross--Neveu model are studied taking into
account the Zeeman interaction of spin-1/2 quasi-particles (electrons) with
tilted (with respect to a system plane) external magnetic field $\vec B=\vec
B_\perp+\vec B_\parallel$. The Zeeman interaction is proportional to magnetic
moment $\mu_B$ of electrons. For simplicity, temperature and chemical potential
are equal to zero throughout the paper. We compare in the framework of the
model the above mentioned phenomena both at $\mu_B=0$ and $\mu_B\ne 0$. It is
shown that at $\mu_B\ne 0$ the magnetic catalysis effect is drastically changed
in comparison with the $\mu_B= 0$ case. Namely, at $\mu_B\ne 0$ the chiral
symmetry, being spontaneously broken by $\vec B$ at subcritical coupling
constants, is always restored at $|\vec B|\to\infty$ (even at $\vec
B_\parallel=0$). Moreover, it is proved in this case that chiral symmetry can
be restored simply by tilting $\vec B$ to a system plane, and in the region $
B_\perp\to 0$ the de Haas -- van Alphen oscillations of the magnetization are
observed. At supercritical values of coupling constant we have found two
chirally non-invariant phases which respond differently on the action of $\vec
B$. The first (at rather small values of $|\vec B|$) is a diamagnetic phase, in
which there is an enhancement of chiral condensate, whereas the second is a
paramagnetic chirally broken phase. Numerical estimates show that phase
transitions described in the paper can be achieved at low enough laboratory
magnetic fields.


title: On the tautological ring of $M_{g,n}$

abstract:
  We state and check the analogue of Faber's conjectures for the tautological
ring of the moduli spaces $M_{g,n}$ of $n$-pointed smooth curves of genus $g$.


title: Holographic turbulence

abstract:
  We construct turbulent black holes in asymptotically AdS_4 spacetime by
numerically solving Einstein equations. Both the dual holographic fluid and
bulk geometry display signatures of an inverse cascade with the bulk geometry
being well approximated by the fluid/gravity gradient expansion. We argue that
statistically steady-state black holes dual to d dimensional turbulent flows
have horizons which are approximately fractal with fractal dimension D=d+4/3.


title: Products of Farey graphs are totally geodesic in the pants graph

abstract:
  We show that for a surface S, the subgraph of the pants graph determined by
fixing a collection of curves that cut S into pairs of pants, once-punctured
tori, and four-times-punctured spheres is totally geodesic. The main theorem
resolves a special case of a conjecture made by Aramayona, Parlier, and
Shackleton and has the implication that an embedded product of Farey graphs in
any pants graph is totally geodesic. In addition, we show that a pants graph
contains a convex n-flat if and only if it contains an n-quasi-flat.


title:
Birth, Growth and Death of an Antivortex during the Propagation of a
  Transverse Domain Wall in Magnetic Nanostrips

abstract:
  Antivortex birth, growth and death due to the propagation of a transverse
domain wall (DW) in magnetic nanostrips are observed and analyzed. Antivortex
formation is an intrinsic process of a strawberry-like transverse DW originated
from magnetostatic interaction. Under an external magnetic field, DW in a wider
width region tends to move faster than that of a narrower part. This speed
mismatch tilts and elongates DW centre line. An antivortex is periodically born
near the tail of the DW centre line. The antivortex either moves along the
centre line and dies on the other side of the strip, or grows to its maximum
size, detaches itself from the DW, and vanishes eventually. The former route
reverses the polarity of DW while the later keeps the DW polarity unchanged.
The evolution of the DW structures is analyzed using winding numbers assigned
to each topological defects. The phase diagram in the field-width plane is
obtained and discussed.


title: Constructions of round fold maps on circle bundles

abstract:
  {\it Fold maps} are fundamental tools in generalizing the theory of Morse
functions and its application to studies of geometric properties of manifolds.
One of the fundamental and important problems in the theory of fold maps is to
construct explicit fold maps, which are often difficult. In this paper, we
construct new examples of {\it round fold maps}, which are defined as {\it
stable fold maps} with singular value sets of concentric spheres introduced by
the author on manifolds having the structures of circle bundles. The class of
round fold maps includes some {\it special generic} maps on homotopy spheres
and such maps have been constructed on manifolds having the structures of
smooth bundles over standard spheres and manifolds represented as connected
sums of manifolds admitting bundle structures over a standard sphere with
fibers diffeomorphic to a standard sphere, for example, in previous studies by
the author in the 2010s. Furthermore, such maps on manifolds admitting the
structures of smooth bundles over spheres or more general manifolds including
families of circle bundles over given manifolds were constructed by applying
operations derived from the theory of bundles ({\it P-operations}), and in this
paper, we use the operations to obtain new round fold maps.


title:
On the Catalyzing Effect of Randomness on the Per-Flow Throughput in
  Wireless Networks

abstract:
  This paper investigates the throughput capacity of a flow crossing a
multi-hop wireless network, whose geometry is characterized by general
randomness laws including Uniform, Poisson, Heavy-Tailed distributions for both
the nodes' densities and the number of hops. The key contribution is to
demonstrate \textit{how} the \textit{per-flow throughput} depends on the
distribution of 1) the number of nodes $N_j$ inside hops' interference sets, 2)
the number of hops $K$, and 3) the degree of spatial correlations. The
randomness in both $N_j$'s and $K$ is advantageous, i.e., it can yield larger
scalings (as large as $\Theta(n)$) than in non-random settings. An interesting
consequence is that the per-flow capacity can exhibit the opposite behavior to
the network capacity, which was shown to suffer from a logarithmic decrease in
the presence of randomness. In turn, spatial correlations along the end-to-end
path are detrimental by a logarithmic term.


title:
Estimation of high-resolution dust column density maps: Empirical model
  fits

abstract:
  Sub-millimetre dust emission is an important tracer of density N of dense
interstellar clouds. One has to combine surface brightness information at
different spatial resolutions, and specific methods are needed to derive N at a
resolution higher than the lowest resolution of the observations. Some methods
have been discussed in the literature, including a method (in the following,
method B) that constructs the N estimate in stages, where the smallest spatial
scales being derived only use the shortest wavelength maps. We propose simple
model fitting as a flexible way to estimate high-resolution column density
maps. Our goal is to evaluate the accuracy of this procedure and to determine
whether it is a viable alternative for making these maps. The new method
consists of model maps of column density (or intensity at a reference
wavelength) and colour temperature. The model is fitted using Markov chain
Monte Carlo (MCMC) methods, comparing model predictions with observations at
their native resolution. We analyse simulated surface brightness maps and
compare its accuracy with method B and the results that would be obtained using
high-resolution observations without noise. The new method is able to produce
reliable column density estimates at a resolution significantly higher than the
lowest resolution of the input maps. Compared to method B, it is relatively
resilient against the effects of noise. The method is computationally more
demanding, but is feasible even in the analysis of large Herschel maps. The
proposed empirical modelling method E is demonstrated to be a good alternative
for calculating high-resolution column density maps, even with considerable
super-resolution. Both methods E and B include the potential for further
improvements, e.g., in the form of better a priori constraints.


title: Sur le comptage des fibr\'es de Hitchin nilpotents

abstract:
  This paper is concerned with two problems. One is to count Hitchin bundles on
a projective curve and the other is to get an explicit formula for the
nilpotent part of the Arthur-Selberg trace formula for a simple test function.
The fact that the two problems are in fact related has been noticed in a
previous paper. We expand the nilpotent part of the Arthur-Selberg trace
formula in a sum of adelic integrals indexed by nilpotent orbits. For "regular
by blocks" orbits, we get an explicit formula for these integrals in terms of
the zeta function of the curve.


title:
Hadron collider potential for excited bosons search: A Snowmass
  whitepaper

abstract:
  The dilepton final states, e+e- and mu+mu-, are the most clear channels for
new heavy neutral resonances search. Their advantage is that the main
irreducible background from the Standard Model Drell-Yan process contributes
usually two orders of magnitude lower than the expected signal under the peak
region. In this paper we are focused on the search of the excited neutral
bosons Z*. At present only the ATLAS Collaboration is looking for such
excitations at LHC. We compare our evaluations with the official collaboration
results at 7 TeV, and present our estimations at higher centre-of-mass energies
in pp collisions and different luminosities.


title:
On the polarization of the final nucleon in NC elastic \nu_\mu
  (\bar\nu_\mu) - N scattering

abstract:
  New short baseline neutrino experiments open new possibilities of high
precision study of different neutrino processes. We present here results of the
calculation of the polarization of final nucleon in elastic NC \nu_\mu
(\bar\nu_\mu)-nucleon scattering. In a numerical analysis the sensitivity to
the different choices of the axial and axial strange form factors is examined.
Measurements of the polarization of the final proton in elastic e-p scattering
drastically changed our knowledge about the electromagnetic form factors of the
proton. From measurement of the nucleon polarization in the NC elastic
scattering a new additional information about the axial G_A(Q^2} and the
strange axial G^s_A(Q^2) form factors of the nucleon could be inferred.


title: Expectations for extreme-mass-ratio bursts from the Galactic Centre

abstract:
  When a compact object on a highly eccentric orbit about a much more massive
body passes through periapsis it emits a short gravitational wave signal known
as an extreme-mass-ratio burst (EMRB). We consider stellar mass objects
orbiting the massive black hole (MBH) found in the Galactic Centre. EMRBs
provide a novel means of extracting information about the MBH; an EMRB from the
Galactic MBH could be highly informative regarding the MBH's mass and spin if
the orbital periapsis is small enough. However, to be a useful astronomical
tool EMRBs must be both informative and sufficiently common to be detectable
with a space-based interferometer. We construct a simple model to predict the
event rate for Galactic EMRBs. We estimate there could be on average ~2 bursts
in a two year mission lifetime for LISA. Stellar mass black holes dominate the
event rate. Creating a sample of 100 mission realisations, we calculate what we
could learn about the MBH. On average, we expect to be able to determine the
MBH mass to ~1% and the spin to ~0.1 using EMRBs.


title:
Qualitative features of the rearrangement of molecular energy spectra
  from a "wall-crossing" perspective

abstract:
  Qualitatively different systems of molecular energy bands are studied on
example of a parametric family of effective Hamiltonians describing rotational
structure of triply degenerate vibrational state of a cubic symmetry molecule.
The modification of band structure under variation of control parameters is
associated with a topological invariant "delta-Chern". This invariant is
evaluated by using a local Hamiltonian for the control parameter values
assigned at the boundary between adjacent parameter domains which correspond to
qualitatively different band structures.


title:
Partially Coherent Optical Modelling of the Ultra-Low-Noise Far-Infrared
  Imaging Arrays on the SPICA Mission

abstract:
  We have developed a range of theoretical and numerical techniques for
modeling the multi-mode, 210-34 micron, ultra-low-noise Transition Edge Sensors
that will be used on the SAFARI instrument on the ESA/JAXA cooled-aperture FIR
space telescope SPICA. The models include a detailed analysis of the resistive
and reactive properties of thin superconducting absorbing films, and a
partially coherent mode-matching analysis of patterned films in multi-mode
waveguide. The technique allows the natural optical modes, modal
responsivities, and Stokes maps of complicated structures comprising patterned
films in profiled waveguides and cavities to be determined.


title:
Line-profile variations in radial-velocity measurements: Two alternative
  indicators for planetary searches

abstract:
  Aims. We introduce two methods to identify false-positive planetary signals
in the context of radial-velocity exoplanet searches. The first is the
bi-Gaussian cross-correlation function fitting, and the second is the
measurement of asymmetry in radial-velocity spectral line information content,
Vasy.
  Methods. We make a systematic analysis of the most used common line profile
diagnosis, Bisector Inverse Slope and Velocity Span, along with the two
proposed ones. We evaluate all these diagnosis methods following a set of
well-defined common criteria and using both simulated and real data. We apply
them to simulated cross-correlation functions created with the program SOAP and
which are affected by the presence of stellar spots, and to real
cross-correlation functions, calculated from HARPS spectra, for stars with a
signal originating both in activity and created by a planet.
  Results. We demonstrate that the bi-Gaussian method allows a more precise
characterization of the deformation of line profiles than the standard bisector
inverse slope. The calculation of the deformation indicator is simpler and its
interpretation more straightforward. More importantly, its amplitude can be up
to 30% larger than that of the bisector span, allowing the detection of
smaller-amplitude correlations with radial-velocity variations. However, a
particular parametrization of the bisector inverse slope is shown to be more
efficient on high-signal-to-noise data than both the standard bisector and the
bi-Gaussian. The results of the Vasy method show that this indicator is more
effective than any of the previous ones, being correlated with the
radial-velocity with more significance for signals resulting from a line
deformation. Moreover, it provides a qualitative advantage over the bisector,
showing significant correlations with RV for active stars for which bisector
analysis is inconclusive. (abridged)


title: Analysis of t tbar H Events at sqrt(s)=14 TeV with H -> WW

abstract:
  We study the process pp -> t tbar H at sqrt(s)=14 TeV where H -> WW. We focus
on final states that include three or four leptons. Signal and background
samples are generated at leading order (LO) and normalized to next-to-leading
order (NLO) calculations. We employ the "Snowmass" detector simulation and
event reconstruction. Cuts are selected which provide a substantial signal
yield while suppressing the main backgrounds. Systematic uncertainties are
estimated for the overall normalization of signal and background processes.
With no improvement in the current theoretical uncertainties on sigma(t tbar
H), we project a precision on a top quark Yukawa coupling of approximately 16%
in 300 fb^-1 and 9% in 3000 fb^-1. If the theoretical uncertainties are halved,
these improve to 14% and 6%, respectively.


title: Cost-Aware Automatic Program Repair

abstract:
  We present a formal framework for repairing infinite-state, imperative,
sequential programs, with (possibly recursive) procedures and multiple
assertions; the framework can generate repaired programs by modifying the
original erroneous program in multiple program locations, and can ensure the
readability of the repaired program using user-defined expression templates;
the framework also generates a set of inductive assertions that serve as a
proof of correctness of the repaired program. As a step toward integrating
programmer intent and intuition in automated program repair, we present a "
cost-aware" formulation - given a cost function associated with permissible
statement modifications, the goal is to ensure that the total program
modification cost does not exceed a given repair budget. As part of our
predicate abstraction-based solution framework, we present a sound and complete
algorithm for repair of Boolean programs. We have developed a prototype tool
based on SMT solving and used it successfully to repair diverse errors in
benchmark C programs.


title: The increased efficiency of fish swimming in a school

abstract:
  There is increasing evidence that fish gain energetic benefits when they swim
in a school. The most recent indications of such benefits are a lower tail (or
fin) beat at the back of a school and reduced oxygen consumption in schooling
fish versus solitary ones. How such advantages may arise is poorly understood.
Current hydrodynamic theories concern either fish swimming side by side or in a
diamond configuration and they largely ignore effects of viscosity and
interactions among wakes and individuals. In reality, however, hydrodynamic
effects are complex and fish swim in many configurations. Since these
hydrodynamic effects are difficult to study empirically, we investigate them in
a computer model by incorporating viscosity and interactions among wakes and
with individuals. We compare swimming efficiency of mullets of 12.6 cm
travelling solitarily and in schools of four different configurations at
several inter-individual distances. The resulting Reynolds number (based on
fish length) is approximately 1150. We show that these fish always swim more
efficiently in a school than alone (except in a dense phalanx). We indicate how
this efficiency may emerge from several kinds of interactions among wakes and
individuals. Since individuals in our simulations are not even intending to
exploit the wake, gains in efficiency are obtained more easily than previously
thought.


title:
Wavelet-based Adaptive Techniques Applied to Turbulent Hypersonic
  Scramjet Intake Flows

abstract:
  The simulation of hypersonic flows is computationally demanding due to large
gradients of the flow variables caused by strong shock waves and thick boundary
or shear layers. The resolution of those gradients imposes the use of extremely
small cells in the respective regions. Taking turbulence into account
intensives the variation in scales even more. Furthermore, hypersonic flows
have been shown to be extremely grid sensitive. For the simulation of
three-dimensional configurations of engineering applications, this results in a
huge amount of cells and prohibitive computational time. Therefore, modern
adaptive techniques can provide a gain with respect to computational costs and
accuracy, allowing the generation of locally highly resolved flow regions where
they are needed and retaining an otherwise smooth distribution. An h-adaptive
technique based on wavelets is employed for the solution of hypersonic flows.
The compressible Reynolds averaged Navier-Stokes equations are solved using a
differential Reynolds stress turbulence model, well suited to predict
shock-wave-boundary-layer interactions in high enthalpy flows. Two test cases
are considered: a compression corner and a scramjet intake. The compression
corner is a classical test case in hypersonic flow investigations because it
poses a shock-wave-turbulent-boundary-layer interaction problem. The adaptive
procedure is applied to a two-dimensional confguration as validation. The
scramjet intake is firstly computed in two dimensions. Subsequently a
three-dimensional geometry is considered. Both test cases are validated with
experimental data and compared to non-adaptive computations. The results show
that the use of an adaptive technique for hypersonic turbulent flows at high
enthalpy conditions can strongly improve the performance in terms of memory and
CPU time while at the same time maintaining the required accuracy of the
results.


title:
Nanolaser in the selfgenerated nonequilibrium environment: quantum
  fluctuations and entanglement

abstract:
  We investigate the dynamics of the spaser-based nanolaser in the strong
incoherent pumping regime in the quantum limit when the photon number is the
order of unity. We consider the situation where the newly irradiated photon
finds itself in the cloud of earlier irradiated photons that are not
thermalized. As the result the entanglement of nanoparticle with quantum dot
degrees of freedom in the nanolaser and the lasing intensity increases several
times. In fact the nonthermal bath effectively makes the nanolaser "more
quantum" and master equation for the nanolaser density matrix nonlinear and
selfconsistent.


title: Squeezing with a flux-driven Josephson parametric amplifier

abstract:
  Josephson parametric amplifiers (JPA) are promising devices for applications
in circuit quantum electrodynamics (QED) and for studies on propagating quantum
microwaves because of their good noise performance. In this work, we present a
systematic characterization of a flux-driven JPA at millikelvin temperatures.
In particular, we study in detail its squeezing properties by two different
detection techniques. With the homodyne setup, we observe squeezing of vacuum
fluctuations by superposing signal and idler bands. For a quantitative analysis
we apply dual-path cross-correlation techniques to reconstruct the Wigner
functions of various squeezed vacuum and thermal states. At 10 dB signal gain,
we find 4.9+-0.2 dB squeezing below vacuum. In addition, we discuss the physics
behind squeezed coherent microwave fields. Finally, we analyze the JPA noise
temperature in the degenerate mode and find a value smaller than the standard
quantum limit for phase-insensitive amplifiers.


title: A Review of Machine Learning based Anomaly Detection Techniques

abstract:
  Intrusion detection is so much popular since the last two decades where
intrusion is attempted to break into or misuse the system. It is mainly of two
types based on the intrusions, first is Misuse or signature based detection and
the other is Anomaly detection. In this paper Machine learning based methods
which are one of the types of Anomaly detection techniques is discussed.


title: A matroid associated with a phylogenetic tree

abstract:
  A (pseudo-)metric $D$ on a finite set $X$ is said to be a `tree metric' if
there is a finite tree with leaf set $X$ and non-negative edge weights so that,
for all $x,y \in X$, $D(x,y)$ is the path distance in the tree between $x$ and
$y$. It is well known that not every metric is a tree metric. However, when
some such tree exists, one can always find one whose interior edges have
strictly positive edge weights and that has no vertices of degree 2, any such
tree is -- up to canonical isomorphism -- uniquely determined by $D$, and one
does not even need all of the distances in order to fully (re-)construct the
tree's edge weights in this case. Thus, it seems of some interest to
investigate which subsets of $\binom{X}{2}$ suffice to determine (`lasso')
these edge weights. In this paper, we use the results of a previous paper to
discuss the structure of a matroid that can be associated with an (unweighted)
$X-$tree $T$ defined by the requirement that its bases are exactly the `tight
edge-weight lassos' for $T$, i.e, the minimal subsets $\cl$ of $\ch$ that lasso
the edge weights of $T$.


title:
Charge-carrier-induced frequency renormalization, damping and heating of
  vibrational modes in nanoscale junctions

abstract:
  In nanoscale junctions the interaction between charge carriers and the local
vibrations results in renormalization, damping and heating of the vibrational
modes. We here formulate a nonequilibrium Green's functions based theory to
describe such effects. Studying a generic junction model with an off-resonant
electronic level, we find a strong bias dependence of the frequency
renormalization and vibrational damping accompanied by pronounced nonlinear
vibrational heating in junctions with intermediate values of the coupling to
the leads. Combining our theory with ab-initio calculations we furthermore show
that the bias dependence of the Raman shifts and linewidths observed
experimentally in an OPV3 junction [D. Ward et al., Nature Nano. 6, 33 (2011)]
may be explained by a combination of dynamic carrier screening and molecular
charging.


title:
Candidate Type II Quasars at 2 < z < 4.3 in the Sloan Digital Sky Survey
  III

abstract:
  At low redshifts, dust-obscured quasars often have strong yet narrow
permitted lines in the rest-frame optical and ultraviolet, excited by the
central active nucleus, earning the designation Type II quasars. We present a
sample of 145 candidate Type II quasars at redshifts between 2 and 4.3,
encompassing the epoch at which quasar activity peaked in the universe. These
objects, selected from the quasar sample of the Baryon Oscillation
Spectroscopic Survey of the Sloan Digital Sky Survey III, are characterized by
weak continuum in the rest-frame ultraviolet (typical continuum magnitude of i
\approx 22) and strong lines of CIV and Ly \alpha, with Full Width at Half
Maximum less than 2000 kms-1. The continuum magnitudes correspond to an
absolute magnitude of -23 or brighter at redshift 3, too bright to be due
exclusively to the host galaxies of these objects. Roughly one third of the
objects are detected in the shorter-wavelength bands of the WISE survey; the
spectral energy distributions (SEDs) of these objects appear to be intermediate
between classic Type I and Type II quasars seen at lower redshift. Five objects
are detected at rest frame 6\mu m by Spitzer, implying bolometric luminosities
of several times 10^46 erg s-1. We have obtained polarization measurements for
two objects; they are roughly 3% polarized. We suggest that these objects are
luminous quasars, with modest dust extinction (A_V ~ 0.5 mag), whose
ultraviolet continuum also includes a substantial scattering contribution.
Alternatively, the line of sight to the central engines of these objects may be
partially obscured by optically thick material.


title:
Slow volume growth for Reeb flows on spherizations and contact
  Bott--Samelson theorems

abstract:
  We give a uniform lower bound for the polynomial complexity of all Reeb flows
on the spherization (S*M,\xi) over a closed manifold. Our measure for the
dynamical complexity of Reeb flows is slow volume growth, a polynomial version
of topological entropy, and our uniform bound is in terms of the polynomial
growth of the homology of the based loops space of M. As an application, we
extend the Bott--Samelson theorem from geodesic flows to Reeb flows: If
(S*M,\xi) admits a periodic Reeb flow, or, more generally, if there exists a
positive Legendrian loop of a fibre S*_q M, then M is a circle or the
fundamental group of M is finite and the integral cohomology ring of the
universal cover of M is the one of a compact rank one symmetric space.


title:
Fit or Unfit : Analysis and Prediction of 'Closed Questions' on Stack
  Overflow

abstract:
  Stack Overflow is widely regarded as the most popular Community driven
Question Answering (CQA) website for programmers. Questions posted on Stack
Overflow which are not related to programming topics, are marked as 'closed' by
experienced users and community moderators. A question can be 'closed' for five
reasons - duplicate, off-topic, subjective, not a real question and too
localized. In this work, we present the first study of 'closed' questions in
Stack Overflow. We download 4 years of publicly available data which contains
3.4 Million questions. We first analyze and characterize the complete set of
0.1 Million 'closed' questions. Next, we use a machine learning framework and
build a predictive model to identify a 'closed' question at the time of
question creation.
  One of our key findings is that despite being marked as 'closed', subjective
questions contain high information value and are very popular with the users.
We observe an increasing trend in the percentage of closed questions over time
and find that this increase is positively correlated to the number of newly
registered users. In addition, we also see a decrease in community
participation to mark a 'closed' question which has led to an increase in
moderation job time. We also find that questions closed with the Duplicate and
Off Topic labels are relatively more prone to reputation gaming. For the
'closed' question prediction task, we make use of multiple genres of feature
sets based on - user profile, community process, textual style and question
content. We use a state-of-art machine learning classifier based on an ensemble
learning technique and achieve an overall accuracy of 73%. To the best of our
knowledge, this is the first experimental study to analyze and predict 'closed'
questions on Stack Overflow.


title: Physics at a High-Luminosity LHC with ATLAS

abstract:
  The physics accessible at the high-luminosity phase of the LHC extends well
beyond that of the earlier LHC program. This white paper, submitted as input to
the Snowmass Community Planning Study 2013, contains preliminary studies of
selected topics, spanning from Higgs boson studies to new particle searches and
rare top quark decays. They illustrate the substantially enhanced physics reach
with an increased integrated luminosity of 3000 fb-1, and motivate the planned
upgrades of the LHC machine and ATLAS detector.


title: Study of luminosity and time evolution in X-ray afterglows of GRBs

abstract:
  Gamma-ray bursts (GRBs), which have been observed up to redshifts $z \approx
9.5$ can be good probes of the early universe and have the potential of testing
cosmological models. The analysis by Dainotti of GRB Swift afterglow
lightcurves with known redshifts and definite X-ray plateau shows an
anti-correlation between the \underline{rest frame} time when the plateau ends
(the plateau end time) and the calculated luminosity at that time (or
approximately an anti-correlation between plateau duration and luminosity). We
present here an update of this correlation with a larger data sample of 101
GRBs with good lightcurves. Since some of this correlation could result from
the redshift dependences of these intrinsic parameters, namely their
cosmological evolution we use the Efron-Petrosian method to estimate the
luminosity and time evolution and to correct for this effects to determine the
intrinsic nature of this correlation.


title: Toward a microscopic description of reactions involving exotic nuclei

abstract:
  We propose an extension of the Continuum Discretized Coupled Channels (CDCC)
method, where the projectile is described by a microscopic cluster model. This
microscopic generalization (MCDCC) only relies on nucleon-target interactions,
and therefore presents an important predictive power. Core excitations can be
included without any further parameter. As an example we investigate the
$\lipb$ elastic scattering at $E_{lab}=27$ and 35 MeV. The $^7$Li nucleus is
known to present an $\alpha+t$ cluster structure, and is well described by the
Resonating Group Method. An excellent agreement is obtained for the $\lipb$
elastic cross sections, provided that breakup channels are properly included.
We also present an application to inelastic scattering, and discuss future
applications of the MCDCC.


title:
What water properties are responsible for the physiological temperature
  interval limits of warm-blooded organisms?

abstract:
  The weighty evidences of specific transformations of the thermal motion in
pure water in the physiological temperature interval (PTI) from (30 +(-) 3)o C
to (42 +(-) 3)o C for warm-blooded organisms are presented. It is shown that
near the right end of the PTI (42 +(-) 3)o C the crystal-like thermal motion in
water transforms to argon-like one (i.e. the dynamic phase transition (DPT)
occurs). It is show that the similar transformation takes also place in
water-Mioglobin solutions. It is proposed that the DPT takes also place in the
intracellular water, where it stimulates the denaturation of proteins. The
restriction of the PTI on the left of (30 +(-) 3)o C is naturally explained by
the clusterization of water molecules, which strongly increases when
temperature drops. The middle, ((36 +(-) 1)o C), of the PTI for warm-blooded
organisms is disposed at the minimum of the heat capacity at constant pressure,
that forwards to the stability of heat-exchange for bio-cells.


title: Algebraic Structure of Combined Traces

abstract:
  Traces and their extension called combined traces (comtraces) are two formal
models used in the analysis and verification of concurrent systems. Both models
are based on concepts originating in the theory of formal languages, and they
are able to capture the notions of causality and simultaneity of atomic actions
which take place during the process of a system's operation. The aim of this
paper is a transfer to the domain of comtraces and developing of some
fundamental notions, which proved to be successful in the theory of traces. In
particular, we introduce and then apply the notion of indivisible steps, the
lexicographical canonical form of comtraces, as well as the representation of a
comtrace utilising its linear projections to binary action subalphabets. We
also provide two algorithms related to the new notions. Using them, one can
solve, in an efficient way, the problem of step sequence equivalence in the
context of comtraces. One may view our results as a first step towards the
development of infinite combined traces, as well as recognisable languages of
combined traces.


title:
Determination of the intrinsic Luminosity Time Correlation in the X-ray
  Afterglows of GRBs

abstract:
  Gamma-ray bursts (GRBs), which have been observed up to redshifts z approx
9.5 can be good probes of the early universe and have the potential of testing
cosmological models. The analysis by Dainotti of GRB Swift afterglow
lightcurves with known redshifts and definite X-ray plateau shows an
anti-correlation between the rest frame time when the plateau ends (the plateau
end time) and the calculated luminosity at that time (or approximately an
anti-correlation between plateau duration and luminosity). We present here an
update of this correlation with a larger data sample of 101 GRBs with good
lightcurves. Since some of this correlation could result from the redshift
dependences of these intrinsic parameters, namely their cosmological evolution
we use the Efron-Petrosian method to reveal the intrinsic nature of this
correlation. We find that a substantial part of the correlation is intrinsic
and describe how we recover it and how this can be used to constrain physical
models of the plateau emission, whose origin is still unknown. The present
result could help clarifing the debated issue about the nature of the plateau
emission.


title: Strong magnetic fields, nuclear matter, and anomalous magnetic moments

abstract:
  In this work we study the influence of a strong magnetic field on the
composition of nuclear matter at T=0 including the anomalous magnetic moment
(AMM) of baryons.


title: New asymptotically sharp Korn and Korn-like inequalities in thin domains

abstract:
  It is well known that Korn inequality plays a central role in the theory of
linear elasticity. In the present work we prove new asymptotically sharp Korn
and Korn-like inequalities in thin curved domains with a non-constant
thickness. This new results will be useful when studying the buckling of
compressed shells, in particular when calculating the critical buckling load.


title: Aberration of starlight experiment

abstract:
  We propose an experiment using a conventional optical telescope to determine
whether aberration of starlight results from special relativistic effects
external to a measurement sensor or from optical effects within a sensor. The
proposed measurements would discriminate between the two starlight aberration
models in an Earth-based experiment. In addition, the measurements would yield
an independent experimental test of relativistic time dilation.


title:
Strain-induced effects on the magnetic and electronic properties of
  epitaxial Fe$_{1-x}$Co$_{x}$Si thin films

abstract:
  We have investigated the Co-doping dependence of the structural, transport,
and magnetic properties of \epsilon-FeCoSi epilayers grown by molecular beam
epitaxy on silicon (111) substrates. Low energy electron diffraction, atomic
force microscopy, X-ray diffraction, and high resolution transmission electron
microscopy studies have confirmed the growth of phase-pure, defect-free
\epsilon-FeCoSi epitaxial films with a surface roughness of ~1 nm. These
epilayers are strained due to lattice mismatch with the substrate, deforming
the cubic B20 lattice so that it becomes rhombohedral. The temperature
dependence of the resistivity changes as the Co concentration is increased,
being semiconducting-like for low $x$ and metallic-like for x \gtrsim 0.3. The
films exhibit the positive linear magnetoresistance that is characteristic of
\epsilon-FeCoSi below their magnetic ordering temperatures $T_\mathrm{ord}$, as
well as the huge anomalous Hall effect of order several \mu\Omega cm. The
ordering temperatures are higher than those observed in bulk, up to 77 K for x
= 0.4. The saturation magnetic moment of the films varies as a function of Co
doping, with a contribution of ~1 \mu_{B}/ Co atom for x \lesssim 0.25. When
taken in combination with the carrier density derived from the ordinary Hall
effect, this signifies a highly spin-polarised electron gas in the low x,
semiconducting regime.


title:
On the Technology Prospects and Investment Opportunities for Scalable
  Neuroscience

abstract:
  Two major initiatives to accelerate research in the brain sciences have
focused attention on developing a new generation of scientific instruments for
neuroscience. These instruments will be used to record static (structural) and
dynamic (behavioral) information at unprecedented spatial and temporal
resolution and report out that information in a form suitable for computational
analysis. We distinguish between recording - taking measurements of individual
cells and the extracellular matrix - and reporting - transcoding, packaging and
transmitting the resulting information for subsequent analysis - as these
represent very different challenges as we scale the relevant technologies to
support simultaneously tracking the many neurons that comprise neural circuits
of interest. We investigate a diverse set of technologies with the purpose of
anticipating their development over the span of the next 10 years and
categorizing their impact in terms of short-term [1-2 years], medium-term [2-5
years] and longer-term [5-10 years] deliverables.


title: Learning to Understand by Evolving Theories

abstract:
  In this paper, we describe an approach that enables an autonomous system to
infer the semantics of a command (i.e. a symbol sequence representing an
action) in terms of the relations between changes in the observations and the
action instances. We present a method of how to induce a theory (i.e. a
semantic description) of the meaning of a command in terms of a minimal set of
background knowledge. The only thing we have is a sequence of observations from
which we extract what kinds of effects were caused by performing the command.
This way, we yield a description of the semantics of the action and, hence, a
definition.


title: Frobenius algebras of corepresentations: gradings

abstract:
  We consider Frobenius algebras in the monoidal category of right comodules
over a Hopf algebra $H$. If $H$ is a group Hopf algebra, we study a more
general Frobenius type property and uncover the structure of graded Frobenius
algebras. Graded symmetric algebras are also investigated.


title: Transdisciplinary electric power grid science

abstract:
  The 20th-century engineering feat that most improved the quality of human
life, the electric power system, now faces discipline-spanning challenges that
threaten that distinction. So multilayered and complex that they resemble
ecosystems, power grids face risks from their interdependent cyber, physical,
social and economic layers. Only with a holistic understanding of the dynamics
of electricity infrastructure and human operators, automatic controls,
electricity markets, weather, climate and policy can we fortify worldwide
access to electricity.


title: Kronecker Sum Decompositions of Space-Time Data

abstract:
  In this paper we consider the use of the space vs. time Kronecker product
decomposition in the estimation of covariance matrices for spatio-temporal
data. This decomposition imposes lower dimensional structure on the estimated
covariance matrix, thus reducing the number of samples required for estimation.
To allow a smooth tradeoff between the reduction in the number of parameters
(to reduce estimation variance) and the accuracy of the covariance
approximation (affecting estimation bias), we introduce a diagonally loaded
modification of the sum of kronecker products representation [1]. We derive a
Cramer-Rao bound (CRB) on the minimum attainable mean squared predictor
coefficient estimation error for unbiased estimators of Kronecker structured
covariance matrices. We illustrate the accuracy of the diagonally loaded
Kronecker sum decomposition by applying it to video data of human activity.


title: Network Decontamination with a Single Agent

abstract:
  Faults and viruses often spread in networked environments by propagating from
site to neighboring site. We model this process of {\em network contamination}
by graphs. Consider a graph $G=(V,E)$, whose vertex set is contaminated and our
goal is to decontaminate the set $V(G)$ using mobile decontamination agents
that traverse along the edge set of $G$. Temporal immunity $\tau(G) \ge 0$ is
defined as the time that a decontaminated vertex of $G$ can remain continuously
exposed to some contaminated neighbor without getting infected itself. The
\emph{immunity number} of $G$, $\iota_k(G)$, is the least $\tau$ that is
required to decontaminate $G$ using $k$ agents. We study immunity number for
some classes of graphs corresponding to network topologies and present upper
bounds on $\iota_1(G)$, in some cases with matching lower bounds. Variations of
this problem have been extensively studied in literature, but proposed
algorithms have been restricted to {\em monotone} strategies, where a vertex,
once decontaminated, may not be recontaminated. We exploit nonmonotonicity to
give bounds which are strictly better than those derived using monotone
strategies.


title: Superfluid phases of $^3$He in a periodic confined geometry

abstract:
  Predictions and discoveries of new phases of superfluid $^3$He in confined
geometries, as well as novel topological excitations confined to surfaces and
edges of near a bounding surface of $^3$He, are driving the fields of
superfluid $^3$He infused into porous media, as well as the fabrication of
sub-micron to nano-scale devices for controlled studies of quantum fluids. In
this report we consider superfluid $^3$He confined in a periodic geometry,
specifically a two-dimensional lattice of square, sub-micron-scale boundaries
("posts") with translational invariance in the third dimension. The equilibrium
phase(s) are inhomogeneous and depend on the microscopic boundary conditions
imposed by a periodic array of posts. We present results for the order
parameter and phase diagram based on strong pair breaking at the boundaries.
The ordered phases are obtained by numerically minimizing the Ginzburg-Landau
free energy functional. We report results for the weak-coupling limit,
appropriate at ambient pressure, as a function of temperature T, lattice
spacing L, and post edge dimension, $d$. For all $d$ in which a superfluid
transition occurs, we find a transition from the normal state to a periodic,
inhomogeneous "polar" phase with $T_{c_1} < T_c$ for bulk superfluid $^3$He.
For fixed lattice spacing, L, there is a critical post dimension, d_c, above
which only the periodic polar phase is stable. For $d < d_c$ we find a second,
low-temperature phase onsetting at $T_{c_2} < T_{c_1}$ from the polar phase to
a periodic "B-like" phase. The low temperature phase is inhomogeneous,
anisotropic and preserves time-reversal symmetry, but unlike the bulk B-phase
has only $D_{4h}$ point symmetry.


title: Optimal Rate Sampling in 802.11 Systems

abstract:
  In 802.11 systems, Rate Adaptation (RA) is a fundamental mechanism allowing
transmitters to adapt the coding and modulation scheme as well as the MIMO
transmission mode to the radio channel conditions, and in turn, to learn and
track the (mode, rate) pair providing the highest throughput. So far, the
design of RA mechanisms has been mainly driven by heuristics. In contrast, in
this paper, we rigorously formulate such design as an online stochastic
optimisation problem. We solve this problem and present ORS (Optimal Rate
Sampling), a family of (mode, rate) pair adaptation algorithms that provably
learn as fast as it is possible the best pair for transmission. We study the
performance of ORS algorithms in both stationary radio environments where the
successful packet transmission probabilities at the various (mode, rate) pairs
do not vary over time, and in non-stationary environments where these
probabilities evolve. We show that under ORS algorithms, the throughput loss
due to the need to explore sub-optimal (mode, rate) pairs does not depend on
the number of available pairs, which is a crucial advantage as evolving 802.11
standards offer an increasingly large number of (mode, rate) pairs. We
illustrate the efficiency of ORS algorithms (compared to the state-of-the-art
algorithms) using simulations and traces extracted from 802.11 test-beds.


title:
A posteriori error analysis for a boundary element method with
  non-conforming domain decomposition

abstract:
  We present and analyze an a posteriori error estimator based on mesh
refinement for the solution of the hypersingular boundary integral equation
governing the Laplacian in three dimensions. The discretization under
consideration is a non-conforming domain decomposition method based on the
Nitsche technique. Assuming a saturation property, we establish
quasi-reliability and efficiency of the error estimator in comparison with the
error in a natural (non-conforming) norm. Numerical experiments with uniform
and adaptively refined meshes confirm our theoretical results.


title:
Oscillatory surface dichroism of an insulating topological insulator
  Bi2Te2Se

abstract:
  Using circular dichroism-angle resolved photoemission spectroscopy
(CD-ARPES), we report a study of the effect of angular momentum transfer
between polarized photons and topological surface states on the surface of
highly bulk insulating topological insulator Bi2Te2Se. The photoelectron
dichroism is found to be strongly modulated by the frequency of the helical
photons including a dramatic sign-flip. Our results suggest that the observed
dichroism and its sign-flip are consequences of strong coupling between the
photon field and the spin-orbit nature of the Dirac modes on the surface. Our
studies reveal the intrinsic dichroic behavior of topological surface states
and point toward the potential utility of bulk insulating topological
insulators in device applications.


title:
Generalization of the Rotne-Prager-Yamakawa mobility and shear
  disturbance tensors

abstract:
  Rotne-Prager-Yamakawa approximation is one of the most commonly used methods
of including hydrodynamic interactions in modelling of colloidal suspensions
and polymer solutions. The two main merits of this approximation is that it
includes all long-range terms (i.e. decaying as R^-3 or slower in interparticle
distances) and that the diffusion matrix is positive definite, which is
essential for Brownian dynamics modelling. Here, we extend the
Rotne-Prager-Yamakawa approach to include both translational and rotational
degrees of freedom, and derive the regularizing corrections to account for
overlapping particles. Additionally, we show how the Rotne-Prager-Yamakawa
approximation can be generalized for other geometries and boundary conditions.