title: Random polynomials and pluripotential-theoretic extremal functions

abstract:
  There is a natural pluripotential-theoretic extremal function V_{K,Q}
associated to a closed subset K of C^m and a real-valued, continuous function Q
on K. We define random polynomials H_n whose coefficients with respect to a
related orthonormal basis are independent, identically distributed
complex-valued random variables having a very general distribution (which
includes both normalized complex and real Gaussian distributions) and we prove
results on a.s. convergence of a sequence 1/n log |H_n| pointwise and in
L^1_{loc}(C^m) to V_{K,Q}. In addition we obtain results on a.s. convergence of
a sequence of normalized zero currents dd^c [1/n log |H_n|] to dd^c V_{K,Q} as
well as asymptotics of expectations of these currents. All these results extend
to random polynomial mappings and to a more general setting of positive
holomorphic line bundles over a compact Kahler manifold.


title:
Observation of $B^+_c \rightarrow J/\psi D_s^+$ and $B^+_c \rightarrow
  J/\psi D_s^{*+}$ decays

abstract:
  The decays $B^+_c \rightarrow J/\psi D_s^+$ and $B^+_c \rightarrow J/\psi
D_s^{*+}$ are observed for the first time using a dataset, corresponding to an
integrated luminosity of 3$fb^{-1}$, collected by the LHCb experiment in
proton-proton collisions at centre-of-mass energies of $\sqrt{s}$=7 and 8 TeV.
The statistical significance for both signals is in excess of 9 standard
deviations. The following ratios of branching fractions are measured to be
$BR(B^+_c \rightarrow J/\psi D_s^+)/BR(B^+_c \rightarrow J/\psi \pi+) = 2.90
\pm 0.57 \pm 0.24$, $BR(B^+_c \rightarrow J/\psi D_s^{*+}) / BR (B^+_c
\rightarrow J/\psi D_s^+) = 2.37 \pm 0.56 \pm 0.10$, where the first
uncertainties are statistical and the second systematic. The mass of the \Bc
meson is measured to be $m_{B^+_c} = 6276.28 \pm 1.44 (stat) \pm 0.36(syst)
MeV/c^2$, using the $B^+_c \rightarrow J/\psi D_s^+$ decay mode.


title:
Hall resistance in quantum Hall metals due to Pancharatnam phase
  retardation and energy level spacing

abstract:
  We derive the trial Hall resistance formula for the quantum Hall metals to
address both the integer and fractional quantum Hall effects. Within the
degenerate Landau levels, Zeeman splitting and level crossings in the presence
of changing magnetic-field strength determine the Pancharatnam phase
retardation, including the phase acceleration or deceleration, which are
related to the changes in the phase and group momenta of a wavefunction. We
discuss the relevant physical postulates with respect to Pancharatnam phase
retardation to qualitatively reproduce the measured Hall resistance's zigzag
curve for both the integer and the fractional filling factors. Along the way,
we give out some hints to falsify our postulates with experiments.


title: Flat Sections and Non-negative Curvature in Pullback Bundles

abstract:
  We give a geometric obstruction to the non-negativity of the sectional
curvature in the total spaces of certain Riemannian submersions with totally
geodesic fibers; applications of this obstruction to several examples are
given.


title:
An analysis method for transmission measurements of superconducting
  resonators with applications to quantum-regime dielectric-loss measurements

abstract:
  Superconducting resonators provide a convenient way to measure loss tangents
of various dielectrics at low temperature. For the purpose of examining the
microscopic loss mechanisms in dielectrics, precise measurements of the
internal quality factor at different values of energy stored in the resonators
are required. Here, we present a consistent method to analyze a LC
superconducting resonator coupled to a transmission line. We first derive an
approximate expression for the transmission S-parameter $S_{21}$ based on a
complete circuit model. In the weak coupling limit, we show that the internal
quality factor is reliably determined by fitting the approximate form of
$S_{21}$. Since the voltage $V$ of the capacitor of the LC circuit is required
to determine the energy stored in the resonator, we next calculate the relation
between $V$ and the forward propagating wave voltage $V_{in}^+$. Due to the
dependence of the quality factor on voltage, $V$ is not simply proportional to
$V_{in}^+$. We find a self-consistent way to determine the relation between $V$
and $V_{in}^+$, which employs only the fitting parameters for $S_{21}$ and a
linear scaling factor. We then examine the resonator transmission in the cases
of port reflection and impedance mismatch. We find that resonator transmission
asymmetry is primarily due to the reflection from discontinuity in transmission
lines. We show that our analysis method to extract the internal quality factor
is robust in the non-ideal cases above. Finally, we show that the analysis
method on LC resonator can be generalize to arbitrary weakly coupled lumped and
distributed resonators. The generalization uses a systematic approximation on
the response function based on the pole and zero which are the closest to the
resonance frequency. This Closest Pole and Zero Method (CPZM) is a valuable
tool for analyzing physical measurements of high-Q resonators.

categories: cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.supr-con quant-ph


title:
A variation of the Canadisation algorithm for the pricing of American
  options driven by L\'evy processes

abstract:
  We introduce an algorithm for the pricing of finite expiry American options
driven by L\'evy processes. The idea is to tweak Carr's `Canadisation' method,
cf. Carr [9] (see also Bouchard et al [5]), in such a way that the adjusted
algorithm is viable for any L\'evy process whose law at an independent,
exponentially distributed time consists of a (possibly infinite) mixture of
exponentials. This includes Brownian motion plus (hyper)exponential jumps, but
also the recently introduced rich class of so-called meromorphic L\'evy
processes, cf. Kyprianou et al [16]. This class contains all L\'evy processes
whose L\'evy measure is an infinite mixture of exponentials which can generate
both finite and infinite jump activity. L\'evy processes well known in
mathematical finance can in a straightforward way be obtained as a limit of
meromorphic L\'evy processes. We work out the algorithm in detail for the
classic example of the American put, and we illustrate the results with some
numerics.


title:
Heterogeneous patterns enhancing static and dynamic texture
  classification

abstract:
  Some mixtures, such as colloids like milk, blood, and gelatin, have
homogeneous appearance when viewed with the naked eye, however, to observe them
at the nanoscale is possible to understand the heterogeneity of its components.
The same phenomenon can occur in pattern recognition in which it is possible to
see heterogeneous patterns in texture images. However, current methods of
texture analysis can not adequately describe such heterogeneous patterns.
Common methods used by researchers analyse the image information in a global
way, taking all its features in an integrated manner. Furthermore, multi-scale
analysis verifies the patterns at different scales, but still preserving the
homogeneous analysis. On the other hand various methods use textons to
represent the texture, breaking texture down into its smallest unit. To tackle
this problem, we propose a method to identify texture patterns not small as
textons at distinct scales enhancing the separability among different types of
texture. We find sub patterns of texture according to the scale and then group
similar patterns for a more refined analysis. Tests were performed in four
static texture databases and one dynamic one. Results show that our method
provides better classification rate compared with conventional approaches both
in static and in dynamic texture.


title:
Measuring Fast Neutrons with Large Liquid Scintillation Detector for
  Ultra-low Background Experiments

abstract:
  We developed a 12-liter volume neutron detector filled with the liquid
scintillator EJ301 that measures neutrons in an underground laboratory where
dark matter and neutrino experiments are located. The detector target is a
cylindrical volume coated on the inside with reflective paint (95%
reflectivity) that significantly increases the detector's light collection. We
demonstrate several calibration techniques using point sources and cosmic-ray
muons for energies up to 20 MeV for this large liquid scintillation detector.
Neutron-gamma separation using pulse shape discrimination with a few MeV
neutrons to hundreds of MeV neutrons is shown for the first time using a large
liquid scintillator.


title:
Nonlinear optical refraction of the dye-doped E7 thermotropic liquid
  crystal at the nematic-isotropic phase transition

abstract:
  It is known that the doping of liquid crystal with dyes usually changes the
physical properties of the host, like the transition temperatures and the
optical absorption among others. In this work we report a study of the
nonlinear optical refraction of a dye doped sample of the E7 thermotropic
liquid crystal by the Z-scan technique. It was found that the nonlinear
refraction of the sample is higher than the undoped one, diverging at the
clearing point. Close to the N-I transition, the nonlinear birefringence is
characterized by a critical exponent that seams to confirm the tricritical
hypothesis of the nature of the N-I phase transition, being independent of the
doping.


title: Ultrafast Reversal of a Fano Resonance in a Plasmon-Exciton System

abstract:
  When a two-level quantum dot and a plasmonic metal nanoantenna are resonantly
coupled by the electromagnetic near field, the system can exhibit a Fano
resonance, resulting in a transparency dip in the optical spectrum of the
coupled system. We calculate the nonlinear response of such a system, for
illumination both by continuous-wave and ultrafast pulsed lasers, using both a
cavity quantum electrodynamics and a semiclassical coupled-oscillator model.
For the experimentally relevant case of meV thermal broadening of the
quantum-dot transition, we predict that femtosecond pulsed illumination can
lead to a reversal of the Fano resonance, with the induced transparency
changing into a superscattering spike in the spectrum. This ultrafast reversal
is due to a transient change in the phase relationship between the dipoles of
the plasmon and the quantum dot. It thus represents a new approach to
dynamically control the collective optical properties and coherence of coupled
nanoparticle systems.


title: A Survey of Software Reliability Models

abstract:
  Software reliability analysis is performed at various stages during the
process of engineering software as an attempt to evaluate if the software
reliability requirements have been (or might be) met. In this report, I present
a summary of some fundamental black-box and white-box software reliability
models. I also present some general shortcomings of these models and suggest
avenues for further research.


title: Marshall-Olkin Extended Zipf Distribution

abstract:
  The Zipf distribution also known as scale-free distribution or discrete
Pareto distribution, is the particular case of Power Law distribution with
support the strictly positive integers. It is a one-parameter distribution with
a linear behaviour in the log-log scale. In this paper the Zipf distribution is
generalized by means of the Marshall-Olkin transformation. The new model has
more flexibility to adjust the probabilities of the first positive integer
numbers while keeping the linearity of the tail probabilities. The main
properties of the new model are presented, and several data sets are analyzed
in order to show the gain obtained by using the generalized model.


title: Detection of electronic nematicity using scanning tunneling microscopy

abstract:
  Electronic nematic phases have been proposed to occur in various correlated
electron systems and were recently claimed to have been detected in scanning
tunneling microscopy (STM) conductance maps of the pseudogap states of the
cuprate high-temperature superconductor Bi2Sr2CaCu2O8+x (Bi-2212). We
investigate the influence of anisotropic STM tip structures on such
measurements and establish, with a model calculation, the presence of a
tunneling interference effect within an STM junction that induces
energy-dependent symmetry-breaking features in the conductance maps. We
experimentally confirm this phenomenon on different correlated electron
systems, including measurements in the pseudogap state of Bi-2212, showing that
the apparent nematic behavior of the imaged crystal lattice is likely not due
to nematic order but is related to how a realistic STM tip probes the band
structure of a material. We further establish that this interference effect can
be used as a sensitive probe of changes in the momentum structure of the
sample's quasiparticles as a function of energy.


title: Spintronics in MoS_2 monolayer quantum wires

abstract:
  We study analytically and numerically spin effects in MoS_2 monolayer
armchair quantum wires and quantum dots. The interplay between intrinsic and
Rashba spin orbit interactions induced by an electric field leads to helical
modes, giving rise to spin filtering in time-reversal invariant systems. The
Rashba spin orbit interaction can also be generated by spatially varying
magnetic fields. In this case, the system can be in a helical regime with
nearly perfect spin polarization. If such a quantum wire is brought into
proximity to an s-wave superconductor, the system can be tuned into a
topological phase, resulting in midgap Majorana fermions localized at the wire
ends.


title:
Calculation of the relativistic Bethe logarithm in the two-center
  problem

abstract:
  We present a variational approach to evaluate relativistic corrections of
order \alpha^2 to the Bethe logarithm for the ground electronic state of the
Coulomb two center problem. That allows to estimate the radiative contribution
at m\alpha^7 order in molecular-like three-body systems such as hydrogen
molecular ions H_2^+ and HD^+, or antiprotonic helium atoms. While we get 10
significant digits for the nonrelativistic Bethe logarithm, calculation of the
relativistic corrections is much more involved especially for small values of
bond length R. We were able to achieve a level of 3-4 significant digits
starting from R=0.2 bohr, that will allow to reach 10^{-10} relative
uncertainty on transition frequencies.


title:
Superintegrable quantum oscillator and Kepler-Coulomb systems on curved
  spaces

abstract:
  An overview of maximally superintegrable classical Hamitonians on spherically
symmetric spaces is presented. It turns out that each of these systems can be
considered either as an oscillator or as a Kepler-Coulomb Hamiltonian. We show
that two possible quantization prescriptions for all these curved systems arise
if we impose that superintegrability is preserved after quantization, and we
prove that both possibilities are gauge equivalent.


title: Correlation study of some solar activity indices in the cycles 21 - 23

abstract:
  The correlation coefficients of the linear regression of six solar indices
versus F10,7 were analyzed in solar cycles 21, 22 and 23. We also analyzed the
interconnection between these indices and F10,7 with help of the approximation
by the polynomials of second order. The indices we've studied in this paper
are: Wolf numbers - W, 530,3 nm coronal line flux - F530, the total solar
irradiance - TSI, Mg II UV-index 280 nm core-to-wing ratio, Flare Index - FI
and Counts of flares. In the most cases the regressions of these solar indices
versus F10,7 are close to linear except the moments of time near to the
minimums and maximums of 11-year activity. For the linear regressions we found
that the values of correlation coefficients Kcorr(t) for the indices versus
F10,7 and W show the cyclic variations with periods approximately equal to the
to half length of 11-year cycle - 5,5 years approximately.


title: A Qualified Kolmogorovian Account of Probabilistic Contextuality

abstract:
  We describe a mathematical language for determining all possible patterns of
contextuality in the dependence of stochastic outputs of a system on its
deterministic inputs. The central notion is that of all possible couplings for
stochastically unrelated outputs indexed by mutually incompatible values of
inputs. A system is characterized by a pattern of which outputs can be
"directly influenced" by which inputs (a primitive relation, hypothetical or
normative), and by certain constraints imposed on the outputs (such as
Bell-type inequalities or their quantum analogues). The set of couplings
compatible with these constraints represents a form of contextuality in the
dependence of outputs on inputs with respect to the declared pattern of direct
influences.


title:
A Short Proof of a Ptolemy-Like Relation for an Even number of Points on
  a Circle Discovered by Jane McDougall

abstract:
  We give a short proof of a Ptolemy-style result first discovered and proved
by Jane McDougall. It may be viewed as a generalization to any even number of
points of the cubic relation connecting the six joint distances of four points
on a circle (whose quadratic relation is the famed Plucker relation, alias
Ptolemy's theorem).
  This article is in fond memory of Andrei Zelevinsky (1953-2013) who loved
Ptolemy's theorem.


title:
System Architecture of HatterHealthConnect: An Integration of Body
  Sensor Networks and Social Networks to Improve Health Awareness

abstract:
  Over the last decade, the demand for efficient healthcare monitoring has
increased and forced the health and wellness industry to embrace modern
technological advances. Body Sensor Networks, or BSNs, can remotely collect
users data and upload vital statistics to servers over the Internet. Advances
in wireless technologies such as cellular devices and Bluetooth increase the
mobility users experience while wearing a body sensor network. When connected
by the proper framework, BSNs can efficiently monitor and record data while
minimizing the energy expenditure of nodes in the BSN. Social networking sites
play a large role in the aggregation and sharing of data between many users.
Connecting a BSN to a social network creates the unique ability to share health
related data with other users through social interaction. In this research, we
present an integration of BSNs and social networks to establish a community
promoting well being and great social awareness. We present the system
architecture; both hardware and software, of a prototype implementation using
Zephyr HxM heart monitor, Intel-Shimmer EMG senor and a Samsung Captivate smart
phone. We provide implementation details for the design on the base station,
the database server and the Facebook application. We illustrate how the Android
application was designed with both functionality and user perspective in mind
that resulted in an easy to use system. This prototype can be used in multiple
health related applications based on the type of sensors used.


title:
Learning Heteroscedastic Models by Convex Programming under Group
  Sparsity

abstract:
  Popular sparse estimation methods based on $\ell_1$-relaxation, such as the
Lasso and the Dantzig selector, require the knowledge of the variance of the
noise in order to properly tune the regularization parameter. This constitutes
a major obstacle in applying these methods in several frameworks---such as time
series, random fields, inverse problems---for which the noise is rarely
homoscedastic and its level is hard to know in advance. In this paper, we
propose a new approach to the joint estimation of the conditional mean and the
conditional variance in a high-dimensional (auto-) regression setting. An
attractive feature of the proposed estimator is that it is efficiently
computable even for very large scale problems by solving a second-order cone
program (SOCP). We present theoretical analysis and numerical results assessing
the performance of the proposed procedure.


title: Magnetoelectric coupling in Haldane spin chain system, Dy2BaNiO5

abstract:
  We report the results of various measurements, namely magnetization, complex
dielectric permittivity and electric polarization (P) on Dy2BaNiO5 as a
function of temperature (T) and magnetic-field (H), apart from heat-capacity
(C), with the primary motivation of exploring the existence of magnetoelectric
(ME) coupling among Haldane spin-chain systems. The M(T) and C(T) data
establish long range magnetic ordering at 58K. The most noteworthy observations
are: (i) Distinct anomalies are observed in dielectric constant ({\epsilon}')
vs T and loss (tan{\delta}) vs T at different temperatures, i.e. 12.5, 30, 50
and 58K; at low temperatures, three magnetic-field-induced transitions are
observed in {\epsilon}' vs H at 6, 40 and 60 kOe. These transition temperatures
and critical magnetic fields track those obtained from magnetization data. This
establishes the existence of strong magnetoelectric coupling in this compound.
(ii) Correspondingly, electric polarization could be observed as a function of
T and H in the magnetically ordered state, thereby indicating magnetism-induced
ferroelectricity in this compound; this result suggests that this compound is a
possible new multiferroic material among spin = 1 (nickel containing) compounds
with successive magnetic transitions and strong magnetoelectric coupling.


title:
Existence of least energy nodal solution for a Schr\"odinger-Poisson
  system in bounded domains

abstract:
  We prove the existence of least energy nodal solution for a class of
Schr\"odinger-Poisson system in a bounded domain $\Omega \subset \mathbb{R}^3$
with nonlinearity having a subcritical growth.


title: On Polynomial Optimization over Non-compact Semi-algebraic Sets

abstract:
  We consider the class of polynomial optimization problems $\inf \{f(x):x\in
K\}$ for which the quadratic module generated by the polynomials that define
$K$ and the polynomial $c-f$ (for some scalar $c$) is Archimedean. For such
problems, the optimal value can be approximated as closely as desired by
solving a hierarchy of semidefinite programs and the convergence is finite
generically. Moreover, the Archimedean condition (as well as a sufficient
coercivity condition) can also be checked numerically by solving a similar
hierarchy of semidefinite programs. In other words, under reasonable
assumptions the now standard hierarchy of SDP-relaxations extends to the
non-compact case via a suitable modification.


title: A New Perspective on Vertex Connectivity

abstract:
  Edge connectivity and vertex connectivity are two fundamental concepts in
graph theory. Although by now there is a good understanding of the structure of
graphs based on their edge connectivity, our knowledge in the case of vertex
connectivity is much more limited. An essential tool in capturing edge
connectivity are edge-disjoint spanning trees. The famous results of Tutte and
Nash-Williams show that a graph with edge connectivity $\lambda$ contains
$\floor{\lambda/2}$ edge-disjoint spanning trees.
  We present connected dominating set (CDS) partition and packing as tools that
are analogous to edge-disjoint spanning trees and that help us to better grasp
the structure of graphs based on their vertex connectivity. The objective of
the CDS partition problem is to partition the nodes of a graph into as many
connected dominating sets as possible. The CDS packing problem is the
corresponding fractional relaxation, where CDSs are allowed to overlap as long
as this is compensated by assigning appropriate weights. CDS partition and CDS
packing can be viewed as the counterparts of the well-studied edge-disjoint
spanning trees, focusing on vertex disjointedness rather than edge
disjointness.
  We constructively show that every $k$-vertex-connected graph with $n$ nodes
has a CDS packing of size $\Omega(k/\log n)$ and a CDS partition of size
$\Omega(k/\log^5 n)$. We prove that the $\Omega(k/\log n)$ CDS packing bound is
existentially optimal.
  Using CDS packing, we show that if vertices of a $k$-vertex-connected graph
are independently sampled with probability $p$, then the graph induced by the
sampled vertices has vertex connectivity $\tilde{\Omega}(kp^2)$. Moreover,
using our $\Omega(k/\log n)$ CDS packing, we get a store-and-forward broadcast
algorithm with optimal throughput in the networking model where in each round,
each node can send one bounded-size message to all its neighbors.


title:
A new fully justified asymptotic model for the propagation of internal
  waves in the Camassa-Holm regime

abstract:
  This study deals with asymptotic models for the propagation of
one-dimensional internal waves at the interface between two layers of
immiscible fluids of different densities, under the rigid lid assumption and
with a flat bottom. We present a new Green-Naghdi type model in the
Camassa-Holm (or medium amplitude) regime. This model is fully justified, in
the sense that it is consistent, well-posed, and that its solutions remain
close to exact solutions of the full Euler system with corresponding initial
data. Moreover, our system allows to fully justify any well-posed and
consistent lower order model; and in particular the so-called Constantin-Lannes
approximation, which extends the classical Korteweg-de Vries equation in the
Camassa-Holm regime.


title: Closed-Form Associators in Permutative Chord Diagrams

abstract:
  Construction of a universal finite-type invariant can be reduced, under
suitable assumptions, to the solution of certain equations (the hexagon and
pentagon equations) in a particular graded associative algebra of chord
diagrams. An explicit, closed-form solution to these equations may, indirectly,
give information about various interesting properties of knots, such as which
knots are ribbon. However, while closed-form solutions (as opposed to solutions
which can only be approximated to successively higher degrees) are needed for
this purpose, such solutions have proven elusive, partly as a result of the
non-commutative nature of the algebra. To make the problem more tractable, we
restrict our attention to solutions of the equations in the subalgebra of
horizontal chord diagrams, viewed as a graded unital permutative algebra --
where `permutative' means that u[x,y]=0 whenever u has degree at least 1. We
show that this restriction leads in a straightforward and fairly short way to a
reduction of the hexagon and pentagon equations to a simpler equation taken
over the algebra of power series in two commuting variables. This equation had
been found and solved explicitly by Kurlin under a superficially different set
of reduction assumptions, which we show here are in fact equivalent to ours.
This paper thus provides an alternative (simpler and shorter) derivation of
Kurlin's equation.


title: Central limit theorem for commutative semigroups of toral endomorphisms

abstract:
  Let $\Cal S$ be an abelian finitely generated semigroup of endomorphisms of a
probability space $(\Omega, {\Cal A}, \mu)$, with $(T_1, ..., T_d)$ a system of
generators in ${\Cal S}$. Given an increasing sequence of domains $(D_n)
\subset \N^d$, a question is the convergence in distribution of the normalized
sequence $|D_n|^{-\frac12} \sum_{{\k} \, \in D_n} \, f \circ T^{\,{\k}}$, for
$f \in L^2_0(\mu)$, where $T^{\k}= T_1^{k_1} ... T_d^{k_d}$, ${\k}= (k_1, ...,
k_d) \in {\N}^d$. After a preliminary spectral study when the action of $\Cal
S$ has a Lebesgue spectrum, we consider $\N^d$- or $\Z^d$-actions given by
commuting toral automorphisms or endomorphisms on $\T^\rho$, $\rho \geq 1$. For
a totally ergodic action by automorphisms, we show a CLT for the above
normalized sequence or other summation methods like barycenters, as well as a
criterion of non-degeneracy of the variance, when $f$ is regular on the torus.
A CLT is also proved for some semigroups of endomorphisms. Classical results on
the existence and the construction of such actions by automorphisms are
recalled.


title: Extracting Herbrand trees from Coq

abstract:
  Software certification aims at proving the correctness of programs but in
many cases, the use of external libraries allows only a conditional proof: it
depends on the assumption that the libraries meet their specifications. In
particular, a bug in these libraries might still impact the certified program.
In this case, the difficulty that arises is to isolate the defective library
function and provide a counter-example. In this paper, we show that this
problem can be logically formalized as the construction of a Herbrand tree for
a contradictory universal theory and address it. The solution we propose is
based on a proof of Herbrand's theorem in the proof assistant Coq. Classical
program extraction using Krivine's classical realizability then translates this
proof into a certified program that computes Herbrand trees. Using this tree
and calls to the library functions, we are able to determine which function is
defective and explicitly produce a counter-example to its specification.


title: On L2 modulus of continuity of Brownian local times and Riesz potentials

abstract:
  This article is concerned with modulus of continuity of Brownian local times.
Specifically, we focus on 3 closely related problems: (a) Limit theorem for a
Brownian modulus of continuity involving Riesz potentials, where the limit law
is an intricate Gaussian mixture. (b) Central limit theorems for the
projections of L2 modulus of continuity for a 1-dimensional Brownian motion.
(c) Extension of the second result to a 2-dimensional Brownian motion. Our
proofs rely on a combination of stochastic calculus and Malliavin calculus
tools, plus a thorough analysis of singular integrals.


title:
Multiplicit\'e du spectre de Steklov sur les surfaces et nombre
  chromatique

abstract:
  We prove several results about the multiplicity of the first Steklov
eigenvalues on compact surfaces with boundary. We improve some bounds on the
multiplicity, especially for the first eigenvalue, and we prove they are sharp
on some surfaces of small genus. In a previous article, we defined a new
chromatic invariant of surfaces with boundary and conjectured that this
invariant is related to the bound on the first eigenvalue. In the present
article, we study this invariant, and prove that the conjecture is true when
the known bound is sharp.


title: Stability of a class of neutral vacuum bubbles

abstract:
  A model that gives rise to vacuum bubbles is considered where the domain wall
field interacts with another real scalar field, resulting in the formation of
domain ribbons within the host domain wall. Ribbon-antiribbon annihilations
produce elementary bosons whose mass inside the wall is different from the mass
in vacuum. Two cases are considered, where the bosons get trapped either within
the bubble wall or the bosons get trapped within the vacuum enclosed by the
bubble. The bosonic (meta)stabilization effect on the bubble is examined in
each case. It is found that when the bosons become trapped within the bubble
wall, the stabilization mechanism lasts for only a limited amount of time, and
then the bubble undergoes unchecked collapse. However, when the bosons become
trapped within the bubble's interior volume, the bubble can be long-lived,
provided that it has a sufficiently thin wall.


title: On spectral assignment for neutral type systems

abstract:
  For a large class of linear neutral type systems the problem of eigenvalues
and eigenvectors assignment is investigated, i.e. finding the system which has
the given spectrum and almost all, in some sense, eigenvectors.


title:
Topology-preserving diffusion of divergence-free vector fields and
  magnetic relaxation

abstract:
  The usual heat equation is not suitable to preserve the topology of
divergence-free vector fields, because it destroys their integral line
structure. On the contrary, in the fluid mechanics literature, on can find
examples of topology-preserving diffusion equations for divergence-free vector
fields. They are very degenerate since they admit all stationary solutions to
the Euler equations of incompressible fluids as equilibrium points. For them,
we provide a suitable concept of "dissipative solutions", which shares common
features with both P.-L. Lions' dissipative solutions to the Euler equations
and the concept of "curves of maximal slopes", a la De Giorgi, recently used to
study the scalar heat equation in very general metric spaces.


title:
On an intrinsic approach of the guiding-center anholonomy and
  gyro-gauge-arbitrariness

abstract:
  In guiding center theory, the standard gyro-angle coordinate is associated
with gyro-gauge dependence, the global existence problem for unit vectors
perpendicular to the magnetic field, and the notion of anholonomy, which is the
failure of the gyro-angle to return to its original value after being
transported around a loop in configuration space. We analyse these three
intriguing topics through the lens of a recently proposed, global,
gauge-independent gyro-angle. This coordinate is constrained, and therefore
necessitates the use of a covariant derivative. It also highlights the
intrinsic meaning and physical content of gyro-gauge freedom and anholonomy.
There are, in fact, many possible covariant derivatives compatible with the
intrinsic gyro-angle, and each possibility corresponds to a different notion of
gyro-angle transport. This observation sheds new light on Littlejohn's notion
of gyro-angle transport and suggests a new derivation of the
recently-discovered global existence condition for unit vectors perpendicular
to the magnetic field. We also discuss the relationship between Cartesian
position-momentum coordinates and the intrinsic gyro-angle.


title: A high-dimensional two-sample test for the mean using random subspaces

abstract:
  A common problem in genetics is that of testing whether a set of highly
dependent gene expressions differ between two populations, typically in a
high-dimensional setting where the data dimension is larger than the sample
size. Most high-dimensional tests for the equality of two mean vectors rely on
naive diagonal or trace estimators of the covariance matrix, ignoring
dependencies between variables. A test recently proposed by Lopes et al. (2012)
implicitly incorporates dependencies by using random pseudo-projections to a
lower-dimensional space. Their test offers higher power when the variables are
dependent, but lacks desirable invariance properties and relies on asymptotic
p-values that are too conservative. We illustrate how a permutation approach
can be used to obtain p-values for the Lopes et al. test and how modifying the
test using random subspaces leads to a test statistic that is invariant under
linear transformations of the marginal distributions. The resulting test does
not rely on assumptions about normality or the structure of the covariance
matrix. We show by simulation that the new test has higher power than competing
tests in realistic settings motivated by microarray gene expression data. We
also discuss the computational aspects of high-dimensional permutation tests
and provide an efficient R implementation of the proposed test.


title:
The effect of the domain topology on the number of positive solutions of
  an elliptic Kirchhoff problem

abstract:
  Using minimax methods and Lusternik-Schnirelmann theory, we study multiple
positive solutions for the Schr\"{o}dinger - Kirchhoff equation $$
M\left(\dis\int_{\Omega_{\lambda}}|\nabla
u|^{2}dx+\dis\int_{\Omega_{\lambda}}u^{2}dx\right)\left[-\Delta u + u \right]=
f(u) $$ in $\Omega_{\lambda} = \lambda\Omega$. The set $\Omega \subset
\mathbb{R}^3$ is a smooth bounded domain, $\lambda>0$ is a parameter, $M$ is a
general continuous function and $f$ is a superlinear continuous function with
subcritical growth. Our main result relates, for large values of $\lambda$, the
number of solutions with the least number of closed and contractible in
$\bar{\Omega}$ which cover $\bar{\Omega}$.


title: Gravitational Infall onto Molecular Filaments

abstract:
  Two aspects of filamentary molecular cloud evolution are addressed: (1)
Exploring analytically the role of the environment for the evolution of
filaments demonstrates that considering them in isolation (i.e. just addressing
the fragmentation stability) will result in unphysical conclusions about the
filament's properties. Accretion can also explain the observed decorrelation
between FWHM and peak column density. (2) Free-fall accretion onto finite
filaments can lead to the characteristic "fans" of infrared-dark clouds around
star-forming regions. The fans may form due to tidal forces mostly arising at
the ends of the filaments, consistent with numerical models and earlier
analytical studies.


title:
Multiple-Antenna Interference Network with Receive Antenna Joint
  Processing and Real Interference Alignment

abstract:
  In this paper, the degrees of freedom (DoF) regions of constant coefficient
multiple antenna interference channels are investigated. First, we consider a
$K$-user Gaussian interference channel with $M_k$ antennas at transmitter $k$,
$1\le k\le K$, and $N_j$ antennas at receiver $j$, $1\le j\le K$, denoted as a
$(K,[M_k],[N_j])$ channel. Relying on a result of simultaneous Diophantine
approximation, a real interference alignment scheme with joint receive antenna
processing is developed. The scheme is used to obtain an achievable DoF region.
The proposed DoF region includes two previously known results as special cases,
namely 1) the total DoF of a $K$-user interference channel with $N$ antennas at
each node, $(K, [N], [N])$ channel, is $NK/2$; and 2) the total DoF of a $(K,
[M], [N])$ channel is at least $KMN/(M+N)$. We next explore
constant-coefficient interference networks with $K$ transmitters and $J$
receivers, all having $N$ antennas. Each transmitter emits an independent
message and each receiver requests an arbitrary subset of the messages.
Employing the novel joint receive antenna processing, the DoF region for this
set-up is obtained. We finally consider wireless X networks where each node is
allowed to have an arbitrary number of antennas. It is shown that the joint
receive antenna processing can be used to establish an achievable DoF region,
which is larger than what is possible with antenna splitting. As a special case
of the derived achievable DoF region for constant coefficient X network, the
total DoF of wireless X networks with the same number of antennas at all nodes
and with joint antenna processing is tight while the best inner bound based on
antenna splitting cannot meet the outer bound. Finally, we obtain a DoF region
outer bound based on the technique of transmitter grouping.


title:
Doping effect of Cu and Ni impurities on the Fe-based superconductor
  Ba0.6K0.4Fe2As2

abstract:
  Copper and Nickel impurities have been doped into the iron pnictide
superconductor Ba0.6K0.4Fe2As2. Resistivity measurements reveal that Cu and Ni
impurities suppress superconducting transition temperature T_c with rates of
\Delta T_c/Cu-1% = -3.5 K and \Delta T_c/Ni-1% = -2.9 K respectively.
Temperature dependence of Hall coefficient R_H of these two series of samples
show that both Cu-doping and Ni-doping can introduce electrons into
Ba0.6K0.4Fe2As2. With more doping, the sign of R_H gradually changes from
positive to negative, while the changing rate of Cu-doped samples is much
faster than that of Ni-doped ones. Combining with the results of
first-principles calculations published previously and the non-monotonic
evolution of the Hall coefficient in the low temperature region, we argue that
when more Cu impurities were introduced into Ba0.6K0.4Fe2As2, the removal of
Fermi spectral weight in the hole-like Fermi surfaces is much stronger than
that in the electron-like Fermi surfaces, which is equivalent to significant
electron doping effect. DC magnetization and the lattice constants analysis
reveal that static magnetic moments and notable lattice compression have been
formed in Cu-doped samples. It seems that the superconductivity can be
suppressed by the impurities disregard whether they are magnetic or nonmagnetic
in nature. This gives strong support to a pairing gap with a sign reversal,
like S^\pm. However, the relatively slow suppression rates of T_c show the
robustness of superconductivity of Ba0.6K0.4Fe2As2 against impurities, implying
that multi-pairing channels may exist in the system.


title:
The effect of interactions on 2D fermionic symmetry-protected
  topological phases with Z2 symmetry

abstract:
  We study the effect of interactions on 2D fermionic symmetry-protected
topological (SPT) phases using the recently proposed braiding statistics
approach. We focus on a simple class of examples: superconductors with a Z2
Ising symmetry. Although these systems are classified by Z in the
noninteracting limit, our results suggest that the classification collapses to
Z8 in the presence of interactions -- consistent with previous work that
analyzed the stability of the edge. Specifically, we show that there are at
least 8 different types of Ising superconductors that cannot be adiabatically
connected to one another, even in the presence of strong interactions. In
addition, we prove that each of the 7 nontrivial superconductors have protected
edge modes.


title: An exact tree projection algorithm for wavelets

abstract:
  We propose a dynamic programming algorithm for projection onto wavelet tree
structures. In contrast to other recently proposed algorithms which only give
approximate tree projections for a given sparsity, our algorithm is guaranteed
to calculate the projection exactly. We also prove that our algorithm has O(Nk)
complexity, where N is the signal dimension and k is the sparsity of the tree
approximation.


title:
Influence of quark masses on the QCD phase diagram in the presence of a
  magnetic field

abstract:
  The most recent lattice results on the QCD phase diagram in the presence of a
strong magnetic field strongly disagree with results from previous lattice
simulations and several model calculations. The most remarkable difference is
the qualitative behavior of the critical temperature as a function of the
magnetic field intensity, which in later results are shown to decrease in
opposition to what was found previously. According to the authors, such a
discrepancy in lattice simulations could be due to different lattice spacing,
or different number of flavors and quark masses. We investigate the influence
of quark masses on the Polyakov- Quark-Meson model and show that, although
quantitatively the results are sensitive to those parameters, the qualitative
behavior remains the same.


title: Joint operation in public key cryptography

abstract:
  We believe that there is no real data protection without our own tools.
Therefore, our permanent aim is to have more of our own codes. In order to
achieve that, it is necessary that a lot of young researchers become interested
in cryptography. We believe that the encoding of cryptographic algorithms is an
important step in that direction, and it is the main reason why in this paper
we present a software implementation of finding the inverse element, the
operation which is essentially related to both ECC (Elliptic Curve
Cryptography) and the RSA schemes of digital signature.


title:
The MIp Toolset: an efficient algorithm for calculating Mutual
  Information in protein alignments

abstract:
  Background: Coevolution within a protein family is often predicted using
statistics that measure the degree of covariation between positions in the
protein sequence. Mutual Information is a measure of dependence between two
random variables that has been used extensively to predict intra-protein
coevolution.
  Results: Here we provide an algorithm for the efficient calculation of Mutual
Information within a protein family. The algorithm uses linked lists which are
directly accessed by a pointer array. The linked list allows efficient storage
of sparse count data caused by protein conservation. The direct access array of
pointers prevents the linked list from being traversed each time it is
modified.
  Conclusions: This algorithm is implemented in the software MIpToolset, but
could also be easily implemented in other Mutual Information based standalone
software or web servers. The current implementation in the MIpToolset has been
critical in large-scale protein family analysis and real-time coevolution
calculations during alignment editing and curation.
  The MIpToolset is available at: https://sourceforge.net/projects/miptoolset/


title:
Collectively-enhanced optomechanical coupling in periodic arrays of
  scatterers

abstract:
  We investigate the optomechanical properties of a periodic array of identical
scatterers placed inside an optical cavity and extend the results of [A.
Xuereb, C. Genes, and A. Dantan, Phys. Rev. Lett. 109, 223601 (2012)]. We show
that operating at the points where the array is transmissive results in linear
optomechanical coupling strengths between the cavity field and collective
motional modes of the array that may be several orders of magnitude larger than
is possible with an equivalent reflective ensemble. We describe and interpret
these effects in detail and investigate the nature of the scaling laws of the
coupling strengths for the different transmissive points in various regimes.


title: X-ray natural dichroism and chiral order in underdoped cuprates

abstract:
  The origin of the Kerr rotation observed in the pseudogap phase of cuprates
has been the subject of much speculation. Recently, it has been proposed that
this rotation might be due to chiral charge order. Here, I investigate whether
such order can be observed by x-ray natural circular dichroism (XNCD). Several
types of charge order were considered, and they can give rise to an XNCD signal
depending on the stacking of the order along the c-axis.


title: Anisotropic Dirac cones in monatomic hexagonal lattices

abstract:
  In the last few years, the fascinating properties of graphene have been
thoroughly investigated. The existence of Dirac cones is the most important
characteristic of the electronic band-structure of graphene. In this
theoretical paper, hexagonal monolayers of silicon (h-Si) and germanium (h-Ge)
are examined using density functional theory, within the generalized gradient
approximation. Our numerical results indicate that both h-Si and h-Ge are
chemically stable. The lattice parameters, electronic dispersion relations and
densities of states for these systems are reported. The electronic dispersion
relations display Dirac cones with the symmetry of an equilateral triangle (the
group D$_3$) in the vicinity of the K points. Hence, the Fermi velocity depends
on the wave vector direction around $K$ points. Fermi velocities for holes and
electrons are significantly different. The maximum and minimum Fermi velocities
are also reported.


title:
Empirical Centroid Fictitious Play: An Approach For Distributed Learning
  In Multi-Agent Games

abstract:
  The paper is concerned with distributed learning in large-scale games. The
well-known fictitious play (FP) algorithm is addressed, which, despite
theoretical convergence results, might be impractical to implement in
large-scale settings due to intense computation and communication requirements.
An adaptation of the FP algorithm, designated as the empirical centroid
fictitious play (ECFP), is presented. In ECFP players respond to the centroid
of all players' actions rather than track and respond to the individual actions
of every player. Convergence of the ECFP algorithm in terms of average
empirical frequency (a notion made precise in the paper) to a subset of the
Nash equilibria is proven under the assumption that the game is a potential
game with permutation invariant potential function. A more general formulation
of ECFP is then given (which subsumes FP as a special case) and convergence
results are given for the class of potential games. Furthermore, a distributed
formulation of the ECFP algorithm is presented, in which, players endowed with
a (possibly sparse) preassigned communication graph, engage in local,
non-strategic information exchange to eventually agree on a common equilibrium.
Convergence results are proven for the distributed ECFP algorithm.


title: Spatial Compressive Sensing for MIMO Radar

abstract:
  We study compressive sensing in the spatial domain to achieve target
localization, specifically direction of arrival (DOA), using multiple-input
multiple-output (MIMO) radar. A sparse localization framework is proposed for a
MIMO array in which transmit and receive elements are placed at random. This
allows for a dramatic reduction in the number of elements needed, while still
attaining performance comparable to that of a filled (Nyquist) array. By
leveraging properties of structured random matrices, we develop a bound on the
coherence of the resulting measurement matrix, and obtain conditions under
which the measurement matrix satisfies the so-called isotropy property. The
coherence and isotropy concepts are used to establish uniform and non-uniform
recovery guarantees within the proposed spatial compressive sensing framework.
In particular, we show that non-uniform recovery is guaranteed if the product
of the number of transmit and receive elements, MN (which is also the number of
degrees of freedom), scales with K(log(G))^2, where K is the number of targets
and G is proportional to the array aperture and determines the angle
resolution. In contrast with a filled virtual MIMO array where the product MN
scales linearly with G, the logarithmic dependence on G in the proposed
framework supports the high-resolution provided by the virtual array aperture
while using a small number of MIMO radar elements. In the numerical results we
show that, in the proposed framework, compressive sensing recovery algorithms
are capable of better performance than classical methods, such as beamforming
and MUSIC.


title: The Natural Composite Higgs

abstract:
  The discovery of the Higgs boson has put considerable pressure on theories
that aim to solve the hierarchy problem. Scenarios in which the Higgs is a
pseudo Nambu-Goldstone boson (NGB) of some new strong dynamics must possess a
number of non-generic features in order to pass the progressively stringent
collider bounds and simultaneously meet our naturalness criteria. Among these
features are the existence of light fermionic partners of the top quark and an
efficient collective breaking of the Nambu-Goldstone symmetry. The top partners
have to be not only parametrically lighter than the other composites, but also
weakly coupled to them in order to suppress unwanted flavor-violating effects.
A Natural pseudo-NGB Higgs model should also be able to fit the LHC Higgs data
without fine-tuning. Among theories with comparable compositeness scales, those
that predict smaller corrections in the Higgs couplings to the standard model
particles are therefore preferred.
  A concrete implementation of these ingredients is discussed in a scenario
based on the coset SU(5)/SO(5). The fit to the current LHC Higgs data is
significantly improved compared to the minimal scenarios, and a fully natural
explanation of both the weak scale and the Higgs boson mass can be attained. An
important role is played by an independent quartic Higgs coupling generated by
UV-sensitive loops involving electroweak doublets mixing with the top partners.
The collider signature of this framework is shown to be rather model-dependent;
in particular, the exotic scalars can alter the phenomenology of the top
partners at a qualitative level.


title: Quenched Invariance Principles via Martingale Approximation

abstract:
  In this paper we survey the almost sure central limit theorem and its
functional form (quenched) for stationary and ergodic processes. For additive
functionals of a stationary and ergodic Markov chain these theorems are known
under the terminology of central limit theorem and its functional form, started
at a point. All these results have in common that they are obtained via a
martingale approximation in the almost sure sense. We point out several
applications of these results to classes of mixing sequences, shift processes,
reversible Markov chains, Metropolis Hastings algorithms.


title:
Improved data analysis of the internal background measurements of
  40Ca100MoO4 scintillation crystals

abstract:
  The sensitivity of neutrinoless double beta (0n2b) decay experiments is
mainly depended on the internal background of a detector which, in its turn, is
defined by the purity of material and possibility for selection of background
events. The AMoRE (Advanced Mo based Rare process Experiment) collaboration
plans to use 40Ca100MoO4 scintillation crystals as a detector for search of
0n2b decay of 100Mo isotope. A purpose of this paper is further investigation
of internal background of 40Ca100MoO4 scintillation elements with a low
background setup at YangYang underground laboratory. We present new approaches
for selection of background events from analyzing data and latest results of
measurements of intrinsic background of 40Ca100MoO4 crystals as an example of
new technique application.


title: N=1 super sinh-Gordon model in the half line: Breather solutions

abstract:
  We examine the N=1 super sinh-Gordon (SShG) model restricted into the half
line through a reduction from the defect SShG model. The B\"acklund
transformations are employed to generate one-, two- and three-soliton solutions
as well as a class of breathers solution for this model. The parameters of such
classical solutions are shown to satisfy some contraints in order to preserve
both integrability and supersymmetry properties of the original bulk theory.
Additionally, previous results are recovered when performing the purely bosonic
limit.


title:
Black hole evolution: III. Statistical properties of mass growth and
  spin evolution using large-scale hydrodynamical cosmological simulations

abstract:
  Supermassive black holes (BH) at the centres of galaxies can rapidly change
their mass and spin by gas accretion and mergers. Using hydrodynamical
cosmological simulations, with prescriptions for BH growth and feedback from
Active Galactic Nuclei, we study how the evolution of BH mass growth is driven
by gas accretion and mergers. Using a semi-analytical approach to evolve spins,
we also highlight the mechanisms responsible for driving the magnitude and the
direction of spins as a function of cosmic time. We find that in the
high-redshift universe galaxies maintain large values of gas accretion onto
BHs, which therefore is the main driver of their mass and spin evolution.
Sustained accretion of cold gas at high-redshift tends to align BH spins with
the angular momentum of the surrounding gas and maximise their magnitude.
Conversely, at low redshift, as BHs get more massive and galaxies more
gas-poor, the contribution from binary coalescences to the total BH mass growth
increases, especially at the high-mass end, and tends to decrease the magnitude
of spins and change their direction.


title:
Ab initio study of the alloying effect of transition metals on
  structure, stability and ductility of CrN

abstract:
  The alloying effect on the lattice parameters, isostructural mixing
enthalpies and ductility of the ternary nitride systems Cr1-xTMxN (TM=Sc, Y;
Ti, Zr, Hf; V, Nb, Ta; Mo, W) in the cubic B1 structure has been investigated
using first-principles calculations. Maximum mixing enthalpy due to large
lattice mismatch in Cr1-xYxN solid solution shows a strong preference for phase
separation, while Cr1-xTaxN exhibits a negative mixing enthalpy in the whole
compositional range with respect to cubic B1 structured CrN and TaN, thus being
unlikely to decompose spinodally. The near-to-zero mixing enthalpies of
Cr1-xScxN and Cr1-xVxN are ascribed to the mutually counteracted electronic and
lattice mismatch effects. Additions of small amounts of V, Nb, Ta, Mo or W into
CrN coatings increase its ductility.


title:
Magnetic Cataclysmic Variables Discovered in the Palomar Transient
  Factory

abstract:
  The Palomar Transient Factory proves to be a prolific source of Magnetic
Cataclysmic Variables, selected by their distinctive photometric variability,
and followed up spectroscopically. Here, we present six new candidate systems,
together with preliminary photometric periods and spectra.


title: The Fokas method to the Sasa-Satsuma equation on the half-line

abstract:
  We present a Riemann-Hilbert problem formalism for the initial-boundary value
problem for the Sasa-Satsuma(SS) equation: $iq_T+\frac{1}{2}q_{XX}+|q|^2q+i\eps
(q_{XXX}+6|q|^2q_X+3q(|q|^2)_X)=0$ on the half-line. And we also analysis the
global relation in this paper.


title: Comparison of cutoffs between lazy walks and Markovian semigroups

abstract:
  We make a connection between the continuous time and lazy discrete time
Markov chains through the comparison of cutoffs and mixing time in total
variation distance. For illustration, we consider finite birth and death chains
and provide a criterion on cutoffs using eigenvalues of the transition matrix.


title: Giovanni de la Fontana, engineer and magician

abstract:
  Giovanni de la Fontana was a man of the Italian Renaissance of the early
fifteenth-century. Besides becoming a doctor of medicine, he was an engineer
who used his skills to mimic the magicians, creating a sort of "artificial
magic".


title: Green's Function of a generalized boundary value transmission problem

abstract:
  The aim of this study is to investigate a class of generalized boundary value
transmission problems (BVTP's) for Sturm-Liouville equation on two separate
intervals. We introduce modified inner product in direct sum space
$L_{2}[a,c)\oplus L_{2}(c,b]\oplus\mathbb{C}^{2}$ and define symmetric linear
operator in it such a way that the considered problem can be interpreted as an
eigenvalue problem of this operator. Then by suggesting an own approaches we
construct Green's function for problem under consideration and find the
resolvent function for corresponding inhomogeneous problem.


title:
Double Whammy - How ICT Projects are Fooled by Randomness and Screwed by
  Political Intent

abstract:
  The cost-benefit analysis formulates the holy trinity of objectives of
project management - cost, schedule, and benefits. As our previous research has
shown, ICT projects deviate from their initial cost estimate by more than 10%
in 8 out of 10 cases. Academic research has argued that Optimism Bias and Black
Swan Blindness cause forecasts to fall short of actual costs. Firstly, optimism
bias has been linked to effects of deception and delusion, which is caused by
taking the inside-view and ignoring distributional information when making
decisions. Secondly, we argued before that Black Swan Blindness makes
decision-makers ignore outlying events even if decisions and judgements are
based on the outside view. Using a sample of 1,471 ICT projects with a total
value of USD 241 billion - we answer the question: Can we show the different
effects of Normal Performance, Delusion, and Deception? We calculated the
cumulative distribution function (CDF) of (actual-forecast)/forecast. Our
results show that the CDF changes at two tipping points - the first one
transforms an exponential function into a Gaussian bell curve. The second
tipping point transforms the bell curve into a power law distribution with the
power of 2. We argue that these results show that project performance up to the
first tipping point is politically motivated and project performance above the
second tipping point indicates that project managers and decision-makers are
fooled by random outliers, because they are blind to thick tails. We then show
that Black Swan ICT projects are a significant source of uncertainty to an
organisation and that management needs to be aware of.


title: R144 revealed as a double-lined spectroscopic binary

abstract:
  R144 is a WN6h star in the 30 Doradus region. It is suspected to be a binary
because of its high luminosity and its strong X-ray flux, but no periodicity
could be established so far. Here, we present new Xshooter multi-epoch
spectroscopy of R144 obtained at the ESO Very Large Telescope (VLT). We detect
variability in position and/or shape of all the spectral lines. We measure
radial velocity variations with an amplitude larger than 250 km/s in NIV and NV
lines. Furthermore, the NIII and NV line Doppler shifts are anti-correlated and
the NIV lines show a double-peaked profile on six of our seven epochs. We thus
conclude that R144 is a double-lined spectroscopic binary. Possible orbital
periods range from 2 to 6 months, although a period up to one year is allowed
if the orbit is highly eccentric. We estimate the spectral types of the
components to be WN5-6h and WN6-7h, respectively. The high luminosity of the
system (log Lbol/Lsun ~ 6.8) suggests a present-day total mass content in the
range of about 200 to 300 Msun, depending on the evolutionary stage of the
components. This makes R144 the most massive binary identified so far, with a
total mass content at birth possibly as large as 400 Msun. We briefly discuss
the presence of such a massive object 60 pc away from the R136 cluster core in
the context of star formation and stellar dynamics.


title:
Investigating Bar Structure of Disc Galaxies via PRIMAL: A
  PaRtIcle-by-particle M2M ALgorithm

abstract:
  We have modified our particle-by-particle adaptation of the made-to-measure
(M2M) method, with the aim of modelling the Galactic disc from upcoming
Galactic stellar survey data. In our new particle-by-particle M2M algorithm,
PRIMAL, the observables of the target system are compared with those of the
model galaxy at the position of the target stars, i.e. particles. The mass of
the model particles are adjusted to reproduce the observables of the target
system, and the gravitational potential is automatically adjusted by the
changing mass of the particles. This paper builds upon our previous work,
introducing likelihood-based velocity constraints in PRIMAL. In this paper we
apply PRIMAL to barred disc galaxies created by a N-body simulation in a known
dark matter potential, with no error in the observables. This paper
demonstrates that PRIMAL can recover the radial profiles of the surface
density, velocity dispersion in the radial and perpendicular directions, and
the rotational velocity of the target discs, along with the apparent bar
structure and pattern speed of the bar, especially when the reference frame is
adjusted so that the bar angle of the target galaxy is aligned to that of the
model galaxy at every timestep.


title: Far-IR Emission From Dust-Obscured Galaxies

abstract:
  Dust-obscured galaxies (DOGs) are a UV-faint, IR-bright galaxy population
that reside at z~2 and are believed to be in a phase of dusty star-forming and
AGN activity. We present far-IR observations of a complete sample of DOGs in
the 2 deg2 of COSMOS. The 3077 DOGs have <z>=1.9+/-0.3 and are selected from
24um and r+ observations using a color cut of r+ - [24]>=7.5 (AB mag) and
S24>=100uJy. Based on the near-IR SEDs, 47% are star-formation dominated and
10% are AGN-dominated. We use SPIRE far-IR photometry from HerMES to calculate
the IR luminosity and characteristic dust temperature for the 1572 (51%) DOGs
that are detected at 250um (>=3{\sigma}). For the remaining 1505 (49%) that are
undetected, we perform a median stacking analysis to probe fainter
luminosities. Detected and undetected DOGs have average IR luminosities of
(2.8+/-0.4) x 1012 LSun and (0.77+-0.08)x10^12LSun, and dust temperatures of
34+/-7 K and 37+/-3 K, respectively. The IR luminosity function of DOGs with
S24>=100uJy is calculated, using far-IR observations and stacking. DOGs
contribute 10-30% to the total star formation rate density of the Universe at
z=1.5-2.5, dominated by 250um detected and bump DOGs. For comparison, DOGs
contribute 30% to the star-formation rate density of the Universe for all
galaxies at z=1.5-2.5 with S24>=100uJy. DOGs have a large scatter about the
star-formation main sequence and their specific star-formation rates show that
the observed phase of star-formation could be responsible for their observed
stellar mass at z~2.


title:
Real or Interloper? The Redshift Likelihoods of z>8 Galaxies in the
  HUDF12

abstract:
  In the absence of spectra, fitting template model spectra to observed
photometric fluxes, known as Spectral Energy Distribution (SED) fitting, has
become the workhorse for identifying high-z galaxies. In this paper, we present
an analysis of the most recent and possibly most distant galaxies discovered in
the Hubble Ultra Deep Field using a more robust method of redshift estimation
based on Markov Chain Monte Carlo fitting (MCMC), rather than relying on the
redshift of "best fit" models obtained using common chi^2 minimization
techniques. The advantage of MCMC fitting is the ability to accurately estimate
the probability density function of the redshift, as well as any other input
model parameters, allowing us to derive accurate credible intervals by properly
marginalizing over all other input model parameters. We apply our method to 13
recently identified sources and show that, despite claims based on chi^2
minimization, none of these sources can be securely ruled out as low redshift
interlopers given the low signal-to-noise of currently available observations.
We estimate that there is an average probability of 21% that these sources are
low redshift interlopers.


title: Quantum annealing with more than one hundred qubits

abstract:
  Quantum technology is maturing to the point where quantum devices, such as
quantum communication systems, quantum random number generators and quantum
simulators, may be built with capabilities exceeding classical computers. A
quantum annealer, in particular, solves hard optimisation problems by evolving
a known initial configuration at non-zero temperature towards the ground state
of a Hamiltonian encoding a given problem. Here, we present results from
experiments on a 108 qubit D-Wave One device based on superconducting flux
qubits. The strong correlations between the device and a simulated quantum
annealer, in contrast with weak correlations between the device and classical
annealing or classical spin dynamics, demonstrate that the device performs
quantum annealing. We find additional evidence for quantum annealing in the
form of small-gap avoided level crossings characterizing the hard problems. To
assess the computational power of the device we compare it to optimised
classical algorithms.


title: CMB spectral distortions from small-scale isocurvature fluctuations

abstract:
  The damping of primordial perturbations at small scales gives rise to
distortions of the cosmic microwave background (CMB). Here, the dependence of
the distortion on the different types of cosmological initial conditions is
explored, covering adiabatic, baryon/cold dark matter isocurvature, neutrino
density/velocity isocurvature modes and some mixtures. The radiation transfer
functions for each mode are determined and then used to compute the dissipative
heating rates and spectral distortion signatures, utilizing both analytic
estimates and numerical results from the thermalization code CosmoTherm. Along
the way, the early-time super-horizon behavior for the resulting fluid modes is
derived in conformal Newtonian gauge, and tight-coupling transfer function
approximations are given. CMB spectral distortions caused by different
perturbation modes can be estimated using simple k-space window functions which
are provided here. Neutrinos carry away some fraction of the primordial
perturbation power, introducing an overall efficiency factor that depends on
the perturbation type. It is shown that future measurements of the CMB
frequency spectrum have the potential to probe different perturbation modes at
very small scales (corresponding to wavenumbers 1 Mpc^{-1} < k < few x 10^4
Mpc^{-1}). These constraints are complementary to those obtained at large
scales and hence provide an exciting new window to early-universe physics.


title:
The Bolocam Galactic Plane Survey. VIII. A Mid-Infrared Kinematic
  Distance Discrimination Method

abstract:
  We present a new distance estimation method for dust-continuum-identified
molecular cloud clumps. Recent (sub-)millimeter Galactic plane surveys have
cataloged tens of thousands of these objects, but detailed study of their
physical properties requires robust distance determinations. We derive Bayesian
distance probability density functions (DPDFs) for 770 objects from the Bolocam
Galactic Plane Survey in the longitude range 7.5 < l < 65. The DPDF formalism
is based on kinematic distances, and uses external data sets to place prior
distance probabilities to resolve the kinematic distance ambiguity (KDA) for
objects in the inner Galaxy. We present priors related to the mid-infrared
absorption of dust in dense molecular regions and the Galactic distribution of
molecular gas. By assuming a numerical model of Galactic mid-infrared emission
and simple radiative transfer, we match the morphology of millimeter thermal
dust emission with mid-infrared absorption to compute a prior DPDF for distance
discrimination. Selecting objects first from (sub-)millimeter source catalogs
avoids a bias towards the darkest infrared dark clouds (IRDCs) and extends the
range of heliocentric distance and contrast range probed by mid-infrared
extinction. We derive well-constrained KDA resolutions for 618 molecular cloud
clumps, with approximately 15% placed at or beyond the tangent distance.
Objects sufficiently dark to be cataloged as IRDCs are generally placed at the
near kinematic distance. Distance comparisons with Galactic Ring Survey KDA
resolutions yield a 92% agreement, and a Galactic face-on view reveals sections
of the Sagittarius and Scutum-Centaurus Arms. This KDA-resolution method for
large catalogs of sources through the combination of (sub-)millimeter and
mid-infrared observations of molecular cloud clumps is generally applicable to
other dust-continuum Galactic plane surveys.


title:
The VLT LBG Redshift Survey - IV. Gas and galaxies at z ~ 3 in
  observations and simulations

abstract:
  We use observations and simulation to study the relationship between
star-forming galaxies and the intergalactic medium at z~3. The observed galaxy
sample is based on spectroscopic redshift data from a combination of the VLT
LBG Redshift Survey and Keck observations in fields centred on bright z>3 QSOs,
whilst the simulation data is taken from GIMIC. In the simulation, we find that
the dominant peculiar velocities are in the form of large-scale coherent
motions of gas and galaxies. Gravitational infall of galaxies towards one
another is also seen. At smaller scales, the peculiar velocities in the
simulation over-predict the difference between the simulated real- and z-space
galaxy correlation functions. Peculiar velocity pairs separated by <1Mpc/h have
a smaller dispersion and explain the z-space correlation function better. The
Ly{\alpha} auto- and cross-correlation functions in the GIMIC simulation show
infall smaller than implied by previous work. This reduced infall may be due to
the galaxy wide outflows implemented in the simulation. The main challenge in
comparing these simulated results with the observed correlation functions comes
from the presence of velocity errors for the observed LBGs which dominate at
~1Mpc/h scales. When these are taken into account, the observed LBG correlation
function is well matched by a simulated $M_*>10^9M_\odot$ galaxy sample. The
simulated cross-correlation shows similar neutral gas densities around galaxies
as are seen in the observations. The simulated and observed Ly{\alpha} z-space
autocorrelation functions agree well with each other. Our overall conclusion is
that gas and galaxy peculiar velocities are towards the low end of expectation.
Finally, little direct evidence is seen in either simulation or observations
for high transmission near galaxies due to feedback. (Abridged)


title: New light on WW scattering at the LHC with W jet tagging

abstract:
  After the recent discovery of a 125 GeV Higgs-like particle at the Large
Hadron Collider (LHC), it is crucial to examine its role in unitarizing high
energy W_LW_L scattering, which may reveal its possible deviation from a
Standard Model Higgs. We perform an updated study on WW scattering in the
semileptonic channel at the LHC, improved by the recently developed W jet
tagging method. The resultant statistical significance of a
Strongly-Interacting Light Higgs (SILH) model is about 20% larger than that
based on the conventionally "gold-plated" dileptonic channel, while 200% more
signal events are retained. This allows the discovery of an SILH model if the
signal strength is 100% (10%) of a pure Higgsless model, using about 40 (3000)
fb^{-1} data at the 14 TeV LHC. Meanwhile, the excellent sensitivity to the
anomalous Higgs-W boson coupling makes semileptonic WW scattering an important
complement to precision measurements at the Higgs resonance.


title: The Current State of Cluster Formation Simulations

abstract:
  Numerical simulations of star cluster formation have advanced greatly during
the past decade, covering increasingly massive gas clouds while accounting for
more and more complex physics. In this review, I discuss the present state of
the field, paying particular attention to the key physics that need to be
included in cluster formation simulations. The main numerical techniques are
summarized for a broad audience, before evaluating their application to the
problem of cluster formation. A faithful reproduction of the observed
characteristics of cluster formation can presently be achieved in numerical
simulations. Ideally, this requires turbulent initial conditions to be combined
with radiative feedback, protostellar outflows, and magnetic fields. With the
exciting prospect in mind that our understanding of cluster formation will soon
be revolutionized by facilities like ALMA, JWST, and the EVLA, this review also
identifies a number of areas that would particularly benefit from a joint
observational and theoretical effort.


title: The Biggest Explosions in the Universe

abstract:
  Supermassive primordial stars are expected to form in a small fraction of
massive protogalaxies in the early universe, and are generally conceived of as
the progenitors of the seeds of supermassive black holes (BHs). Supermassive
stars with masses of ~55,000 M_Sun, however, have been found to explode and
completely disrupt in a supernova (SN) with an energy of up to ~10^55 erg
instead of collapsing to a BH. Such events, ~10,000 times more energetic than
typical SNe today, would be among the biggest explosions in the history of the
universe. Here we present a simulation of such a SN in two stages. Using the
RAGE radiation hydrodynamics code we first evolve the explosion from an early
stage through the breakout of the shock from the surface of the star until the
blast wave has propagated out to several parsecs from the explosion site, which
lies deep within an atomic cooling dark matter (DM) halo at z ~ 15. Then, using
the GADGET cosmological hydrodynamics code we evolve the explosion out to
several kiloparsecs from the explosion site, far into the low-density
intergalactic medium. The host DM halo, with a total mass of 4 x 10^7 M_Sun,
much more massive than typical primordial star-forming halos, is completely
evacuated of high density gas after < 10 Myr, although dense metal-enriched gas
recollapses into the halo, where it will likely form second-generation stars
with metallicities of ~ 0.05 Z_Sun after > 70 Myr. The chemical signature of
supermassive star explosions may be found in such long-lived second-generation
stars today.


title:
Characterizing and curating conversation threads: Expansion, focus,
  volume, re-entry

abstract:
  Discussion threads form a central part of the experience on many Web sites,
including social networking sites such as Facebook and Google Plus and
knowledge creation sites such as Wikipedia. To help users manage the challenge
of allocating their attention among the discussions that are relevant to them,
there has been a growing need for the algorithmic curation of on-line
conversations --- the development of automated methods to select a subset of
discussions to present to a user.
  Here we consider two key sub-problems inherent in conversational curation:
length prediction --- predicting the number of comments a discussion thread
will receive --- and the novel task of re-entry prediction --- predicting
whether a user who has participated in a thread will later contribute another
comment to it. The first of these sub-problems arises in estimating how
interesting a thread is, in the sense of generating a lot of conversation; the
second can help determine whether users should be kept notified of the progress
of a thread to which they have already contributed. We develop and evaluate a
range of approaches for these tasks, based on an analysis of the network
structure and arrival pattern among the participants, as well as a novel
dichotomy in the structure of long threads. We find that for both tasks,
learning-based approaches using these sources of information yield improvements
for all the performance metrics we used.


title:
Role of current quark mass dependent multi-quark interactions in low
  lying meson mass spectra

abstract:
  We call attention to a class of current-quark mass dependent multi-quark
interaction terms which break explicitly the chiral $SU(3)_L\times SU(3)_R$ and
$U_A(1)$ symmetries. They complete the set of effective quark interactions that
contribute at the same order in $N_c$ as the 't Hooft flavor determinant
interaction and the eight quark interactions in the phase of spontaneously
broken chiral symmetry. The $N_c$ classification scheme matches the counting
rules based on arguments set by the scale of spontaneous chiral symmetry
breaking. Together with the leading in $N_c$ four quark Nambu-Jona-Lasinio
Lagrangian and current quark mass matrix, the model is apt to account for the
correct empirical ordering and magnitude of the splitting of states in the low
lying mass spectra of spin zero mesons. The new terms turn out to be essential
for the ordering $m_K < m_\eta$ in the pseudoscalar sector and $m_{\kappa_0} <
m_{a_0}\sim m_{f0}$ for the scalars.


title:
Modeling the amorphous structure of a mechanically alloyed Ti50Ni25Cu25
  alloy using anomalous wide-angle x-ray scattering and reverse Monte Carlo
  simulations

abstract:
  An amorphous Ti50Ni25Cu25 alloy was produced by 19 h of mechanical alloying.
Anomalous wide angle x-ray scattering data were collected at six energies and
six total scattering factors were obtained. By considering the data collected
at two energies close to the Ni and Cu K edges, two differential anomalous
scattering factors around the Ni and Cu atoms were obtained, showing the
chemical environments around these atoms are different. The eight factors were
used as input data to the reverse Monte Carlo method used to compute the
partial structure factors STi-Ti(K), STi-Cu(K), STi-Ni(K), SCu-Cu(K), SCu-Ni(K)
and SNi-Ni(K). From their Fourier transformation, the partial pair distribution
functions GTi-Ti(r), GTi-Cu(r), GTi-Ni(r), GCu-Cu(r), GCu-Ni(r) and GNi-Ni(r)
were obtained, and the coordination numbers and interatomic atomic distances
for the first neighbors were determined.


title:
Universal slow growth of entanglement in interacting strongly disordered
  systems

abstract:
  Recent numerical work by Bardarson et. al. [Phys. Rev. Lett. 109, 017202
(2012)] revealed a slow, logarithmic in time, growth of entanglement entropy
for initial product states in a putative many-body localized phase. We show
that this surprising phenomenon results from the dephasing due to exponentially
small interaction-induced corrections to the eigenenergies of different states.
For weak interactions, we find that the entanglement entropy grows as \xi ln
(Vt/\hbar), where V is the interaction strength, and \xi is the single-particle
localization length. The saturated value of the entanglement entropy at long
times is determined by the participation ratios of the initial state over the
eigenstates of the subsystem. The proposed mechanism is illustrated with
numerical simulations of small systems. Our work shows that the logarithmic
entanglement growth is a universal phenomenon characteristic of the many-body
localized phase in any number of spatial dimensions, and reveals a broad
hierarchy of dephasing time scales present in such a phase.


title: Radiative corrections to chiral separation effect in QED

abstract:
  We calculate the leading radiative corrections to the axial current in the
chiral separation effect in dense QED in a magnetic field. Contrary to the
conventional wisdom suggesting that the axial current should be exactly fixed
by the chiral anomaly relation and is described by the topological contribution
on the lowest Landau level in the free theory, we find in fact that the axial
current receives nontrivial radiative corrections. The direct calculations
performed to the linear order in the external magnetic field show that the
nontrivial radiative corrections to the axial current are provided by the Fermi
surface singularity in the fermion propagator at nonzero fermion density.


title: Sending classical information through relativistic quantum channels

abstract:
  We investigate how special relativity influences the transmission of
classical information through quantum channels by evaluating the Holevo bound
when the sender and the receiver are in (relativistic) relative motion. By
using the spin degrees of freedom of spin-1/2 fermions to encode the classical
information we show that, for some configurations, the accessible information
in the receiver can be increased when the spin detector moves fast enough. This
is possible by allowing the momentum wave packet of one of the particles to be
wide enough while the momentum wave packets of other particles are kept
relatively narrow. In this way, one can take advantage of the fact that boosts
entangle the spin and momentum degrees of freedom of spin-1/2 fermions to
increase the accessible information in the former. We close the paper with a
discussion of how this relativistic quantum channel cannot in general be
described by completely positive quantum maps.


title: Modulated Electromechanics: Large Enhancements of Nonlinearities

abstract:
  It is well-known that the nonlinear coupling between a mechanical oscillator
and a superconducting oscillator or optical cavity can be used to generate a
Kerr-nonlinearity for the cavity mode. We show that the strength of this
Kerr-nonlinearity, as well as the effect of the photon-pressure force can be
enormously increased by modulating the strength of the nonlinear coupling. We
present an electromechanical circuit in which this enhancement can be readily
realized.


title: Exact Rosenthal-type bounds

abstract:
  It is shown that, for any given $p\ge5$, $A>0$ and $B>0$, the exact upper
bound on $\mathsf{E}|\sum X_i|^p$ over all independent zero-mean random
variables (r.v.'s) $X_1,\ldots,X_n$ such that $\sum\mathsf{E}X_i^2=B$ and
$\sum\mathsf{E}|X_i|^p=A$ equals $c^p\mathsf{E}|\Pi_{\lambda}-\lambda|^p$,
where $(\lambda ,c)\in(0,\infty)^2$ is the unique solution to the system of
equations $c^p\lambda=A$ and $c^2\lambda=B$, and $\Pi_{\lambda}$ is a Poisson
r.v. with mean $\lambda$. In fact, a more general result is obtained, as well
as other related ones. As a tool used in the proof, a calculus of variations of
moments of infinitely divisible distributions with respect to variations of the
L\'{e}vy characteristics is developed.


title: Spectral Compressed Sensing via Structured Matrix Completion

abstract:
  The paper studies the problem of recovering a spectrally sparse object from a
small number of time domain samples. Specifically, the object of interest with
ambient dimension $n$ is assumed to be a mixture of $r$ complex
multi-dimensional sinusoids, while the underlying frequencies can assume any
value in the unit disk. Conventional compressed sensing paradigms suffer from
the {\em basis mismatch} issue when imposing a discrete dictionary on the
Fourier representation. To address this problem, we develop a novel
nonparametric algorithm, called enhanced matrix completion (EMaC), based on
structured matrix completion. The algorithm starts by arranging the data into a
low-rank enhanced form with multi-fold Hankel structure, then attempts recovery
via nuclear norm minimization. Under mild incoherence conditions, EMaC allows
perfect recovery as soon as the number of samples exceeds the order of
$\mathcal{O}(r\log^{2} n)$. We also show that, in many instances, accurate
completion of a low-rank multi-fold Hankel matrix is possible when the number
of observed entries is proportional to the information theoretical limits
(except for a logarithmic gap). The robustness of EMaC against bounded noise
and its applicability to super resolution are further demonstrated by numerical
experiments.


abstract:
  The Workshop on results of the Project Kosmomikrofizyka-2 (Astroparticle
Physics) of the National Academy of Sciences (NAS) of Ukraine "Astrophysical
and cosmological problems of invisible mass and dark energy in the Universe"
was held on November 21-22, 2012 in the Institute for Nuclear Research, Kyiv,
Ukraine (http://lpd.kinr.kiev.ua/kmf12). This Project was carried out during
three years (2010-2012) by scientists from various universities and institutes
of the National Academy of Sciences of Ukraine; it was a logical continuation
of the previous scientific program of the NAS of Ukraine "Researches of
structure and composition of the Universe, hidden mass and dark energy
(Kosmomikrofizyka)" in 2007-2009. These programs were devoted to theoretical
and experimental investigations in astronomy, astrophysics, cosmology, physics
of atomic nuclei and particle physics, which are related with the problems of
dark matter and dark energy in the Universe.


title:
Exact form of the exponential correlation function in the glassy
  super-rough phase

abstract:
  We consider the random-phase sine-Gordon model in two dimensions. It
describes two-dimensional elastic systems with random periodic disorder, such
as pinned flux-line arrays, random field XY models, and surfaces of disordered
crystals. The model exhibits a super-rough glass phase at low temperature
$T<T_{c}$ with relative displacements growing with distance $r$ as
$\bar{\langle [\theta(r)-\theta(0)]^2\rangle} \simeq A(\tau) \ln^2 (r/a)$,
where $A(\tau) = 2 \tau^2- 2 \tau^3 +\mathcal{O}(\tau^4)$ near the transition
and $\tau=1-T/T_{c}$. We calculate all higher cumulants and show that they grow
as $\bar{\langle[\theta(r)-\theta(0)]^{2n}\rangle}_c \simeq [2 (-1)^{n+1} (2n)!
\zeta(2n-1) \tau^2 + \mathcal{O}(\tau^3) ] \ln(r/a)$, $n \geq 2$, where $\zeta$
is the Riemann zeta function. By summation, we obtain the decay of the
exponential correlation function as $\bar{\langle
e^{iq\left[\theta(r)-\theta(0)\right]}\rangle} \simeq (a/r)^{\eta(q)}
\exp\boldsymbol(-\frac{1}{2}\mathcal{A}(q)\ln^2(r/a)\boldsymbol)$ where
$\eta(q)$ and ${\cal A}(q)$ are obtained for arbitrary $q \leq 1$ to leading
order in $\tau$. The anomalous exponent is $\eta(q) = c q^2 - \tau^2 q^2
[2\gamma_E+\psi(q)+\psi(-q)]$ in terms of the digamma function $\psi$, where
$c$ is non-universal and $\gamma_E$ is the Euler constant. The correlation
function shows a faster decay at $q=1$, corresponding to fermion operators in
the dual picture, which should be visible in Bragg scattering experiments.


title:
On the Benefits of Sampling in Privacy Preserving Statistical Analysis
  on Distributed Databases

abstract:
  We consider a problem where mutually untrusting curators possess portions of
a vertically partitioned database containing information about a set of
individuals. The goal is to enable an authorized party to obtain aggregate
(statistical) information from the database while protecting the privacy of the
individuals, which we formalize using Differential Privacy. This process can be
facilitated by an untrusted server that provides storage and processing
services but should not learn anything about the database. This work describes
a data release mechanism that employs Post Randomization (PRAM), encryption and
random sampling to maintain privacy, while allowing the authorized party to
conduct an accurate statistical analysis of the data. Encryption ensures that
the storage server obtains no information about the database, while PRAM and
sampling ensures individual privacy is maintained against the authorized party.
We characterize how much the composition of random sampling with PRAM increases
the differential privacy of system compared to using PRAM alone. We also
analyze the statistical utility of our system, by bounding the estimation error
- the expected l2-norm error between the true empirical distribution and the
estimated distribution - as a function of the number of samples, PRAM noise,
and other system parameters. Our analysis shows a tradeoff between increasing
PRAM noise versus decreasing the number of samples to maintain a desired level
of privacy, and we determine the optimal number of samples that balances this
tradeoff and maximizes the utility. In experimental simulations with the UCI
"Adult Data Set" and with synthetically generated data, we confirm that the
theoretically predicted optimal number of samples indeed achieves close to the
minimal empirical error, and that our analytical error bounds match well with
the empirical results.


title:
Determination of the $\Delta(1232)$ axial and pseudoscalar form factors
  from lattice QCD

abstract:
  We present a lattice QCD calculation of the $\Delta(1232)$ matrix elements of
the axial-vector and pseudoscalar currents. The decomposition of these matrix
elements into the appropriate Lorentz invariant form factors is carried out and
the techniques to calculate the form factors are developed and tested using
quenched configurations. Results are obtained for 2+1 domain wall fermions and
within a hybrid scheme with domain wall valence and staggered sea quarks. Two
Goldberger-Treiman type relations connecting the axial to the pseudoscalar
effective couplings are derived. These and further relations based on the
pion-pole dominance hypothesis are examined using the lattice QCD results,
finding support for their validity. Utilizing lattice QCD results on the axial
charges of the nucleon and the $\Delta$, as well as the nucleon-to-$\Delta$
transition coupling constant, we perform a combined chiral fit to all three
quantities and study their pion mass dependence as the chiral limit is
approached.


title: Superfluid qubit systems with ring shaped optical lattices

abstract:
  We study an experimentally feasible qubit system employing neutral atomic
currents. Our system is based on bosonic cold atoms trapped in ring-shaped
optical lattice potentials. The lattice makes the system strictly one
dimensional and it provides the infrastructure to realize a tunable ring-ring
interaction. Our implementation combines the low decoherence rates of of
neutral cold atoms systems, overcoming single site addressing, with the
robustness of topologically protected solid state Josephson flux qubits.
Characteristic fluctuations in the magnetic fields affecting Josephson junction
based flux qubits are expected to be minimized employing neutral atoms as flux
carriers. By breaking the Galilean invariance we demonstrate how atomic
currents through the lattice provide a implementation of a qubit. This is
realized either by artificially creating a phase slip in a single ring, or by
tunnel coupling of two homogeneous ring lattices. The single qubit
infrastructure is experimentally investigated with tailored optical potentials.
Indeed, we have experimentally realized scaled ring-lattice potentials that
could host, in principle, $n\sim 10$ of such ring-qubits, arranged in a stack
configuration, along the laser beam propagation axis.
  An experimentally viable scheme of the two-ring-qubit is discussed, as well.
  Based on our analysis, we provide protocols to initialize, address, and
read-out the qubit.


title: Nonlinear instability of scalar fields on extremal black holes

abstract:
  We prove a new type of finite time blow-up for a class of semilinear wave
equations on extremal black holes. The initial data can be taken to be
arbitrarily close to the trivial data. The first singularity occurs along the
(degenerate) future event horizon. No analogue of this instability occurs for
subextremal black holes or the Minkowski spacetime.


title: Possible Nematic Order Driven by Magnetic Fluctuations in Iron Pnictides

abstract:
  In this paper, instabilities of the isotropic metallic phase in iron
pnictides are investigated. The relevant quartic fermionic interaction terms in
the model are identified using phase space arguments. Using the functional
integral formalism, a Hubbard-Stratonovich transformation is used to decouple
these quartic terms. This procedure introduces several bosonic fields which
describe the low-energy collective modes of the system. By studying the
behavior of these collective modes, a possible instability is found in the
forward scattering channel of the isotropic phase driven by magnetic
fluctuations. Using mean field analysis, we obtain a static and homogeneous
ground state. This ground state is metallic, but the electron Fermi pockets are
distorted unequally at different pockets in momentum space. This results in a
desirable nematic ordering which breaks the lattice C4 symmetry but preserves
translational symmetry and may explain several experimental observations.


title: Auction Algorithm for Production Models

abstract:
  We show an auction-based algorithm to compute market equilibrium prices in a
production model, where consumers purchase items under separable nonlinear
utility concave functions which satisfy W.G.S(Weak Gross Substitutes);
producers produce items with multiple linear production constraints. Our
algorithm differs from previous approaches in that the prices are allowed to
both increase and decrease to handle changes in the production. This provides a
t^atonnement style algorithm which converges and provides a PTAS. The algorithm
can also be extended to arbitrary convex production regions and the
Arrow-Debreu model. The convergence is dependent on the behavior of the
marginal utility of the concave function.


title: An Adaptive and Intelligent Tutor by Expert Systems for Mobile Devices

abstract:
  Mobile Learning (M-Learning) is an emerging discipline in the area of
education and educational technology. So researchers are trying to optimize and
expanding its application in the field of education. The aim of this paper is
to investigate the role of mobile devices and expert systems in disseminating
and supporting the knowledge gained by intelligent tutors and to propose a
system based on integration of intelligent M-Learning with expert systems. It
acts as an intelligent tutor which can perform three processes - pre-test,
learning concept and post-test - according to characteristic of the learner.
The proposed system can improves the education efficiency highly as well as
decreases costs. As a result, every time and everywhere (ETEW) simple and cheap
learning would be provided via SMS, MMS and so on in this system. The global
intention of M-Learning is to make learning "a way of being".


title: XORRO: Rapid Paired-End Read Overlapper

abstract:
  Background: Computational analysis of next-generation sequencing data is
outpaced by data generation in many cases. In one such case, paired-end reads
can be produced from the Illumina sequencing method faster than they can be
overlapped by downstream analysis. The advantages in read length and accuracy
provided by overlapping paired-end reads demonstrates the necessity for
software to efficiently solve this problem.
  Results: XORRO is an extremely efficient paired-end read overlapping program.
XORRO can overlap millions of short paired-end reads in a few minutes. It uses
64-bit registers with a two bit alphabet to represent sequences and does
comparisons using low-level logical operations like XOR, AND, bitshifting and
popcount.
  Conclusions: As of the writing of this manuscript, XORRO provides the fastest
solution to the paired-end read overlap problem. XORRO is available for
download at: sourceforge.net/projects/xorro-overlap/


title:
Optimal Multiuser Zero-Forcing with Per-Antenna Power Constraints for
  Network MIMO Coordination

abstract:
  We consider a multi-cell multiple-input multiple-output (MIMO) coordinated
downlink transmission, also known as network MIMO, under per-antenna power
constraints. We investigate a simple multiuser zero-forcing (ZF) linear
precoding technique known as block diagonalization (BD) for network MIMO. The
optimal form of BD with per-antenna power constraints is proposed. It involves
a novel approach of optimizing the precoding matrices over the entire null
space of other users' transmissions.
  An iterative gradient descent method is derived by solving the dual of the
throughput maximization problem, which finds the optimal precoding matrices
globally and efficiently. The comprehensive simulations illustrate several
network MIMO coordination advantages when the optimal BD scheme is used. Its
achievable throughput is compared with the capacity region obtained through the
recently established duality concept under per-antenna power constraints.