title:
Partial-measurement back-action and non-classical weak values in a
  superconducting circuit

abstract:
  We realize indirect partial measurement of a transmon qubit in circuit
quantum electrodynamics by interaction with an ancilla qubit and projective
ancilla measurement with a dedicated readout resonator. Accurate control of the
interaction and ancilla measurement basis allows tailoring the measurement
strength and operator. The tradeoff between measurement strength and qubit
back-action is characterized through the distortion of a qubit Rabi oscillation
imposed by ancilla measurement in different bases. Combining partial and
projective qubit measurements, we provide the solid-state demonstration of the
correspondence between a non-classical weak value and the violation of a
Leggett-Garg inequality.


title:
An obstruction to subfactor principal graphs from the graph planar
  algebra embedding theorem

abstract:
  We find a new obstruction to the principal graphs of subfactors. It shows
that in a certain family of 3-supertransitive principal graphs, there must be a
cycle by depth 6, with one exception, the principal graph of the Haagerup
subfactor.


title: Quantum corrected phase diagram of holographic fermions

abstract:
  We study the phases of strongly correlated electron systems in two spatial
dimensions in the framework of AdS${}_4$/CFT${}_3$ correspondence. The AdS
(gravity) model consists of a Dirac fermion coupled to electromagnetic field
and gravity. To classify the ground states of strongly correlated electrons on
the CFT side and to construct the full phase diagram of the system, we
construct a quantum many-body model of bulk fermion dynamics, based on the WKB
approximation to the Dirac equation. At low temperatures, we find a quantum
corrected approximation to the electron star where the edge is resolved in
terms of wavefunctions extended fully through AdS. At high temperatures, the
system exhibits a {\em first} order thermal phase transition to a charged
AdS-RN black hole in the bulk and the emergence of local quantum criticality on
the CFT side. This change from the third order transition experienced by the
semi-classical electron star restores the intuition that the transition between
the critical AdS-RN liquid and the finite density Fermi system is of van der
Waals liquid-gas type.


title: Measuring Agglomeration of Agglomerated Particles Pictures

abstract:
  In this article, we introduce a novel geometrical index $\delta_{agg}$, which
is associated with the Euler number and is obtained by an image processing
procedure for a given digital picture of aggregated particles such that
$\delta_{agg}$ exhibits the degree of the agglomerations of the particles. In
the previous work (Matsutani, Shimosako, Wang, Appl.Math.Modeling {\bf{37}}
(2013), 4007-4022), we proposed an algorithm to construct a picture of
agglomerated particles as a Monte-Carlo simulation whose agglomeration degree
is controlled by $\gamma_{agg} \in (0,1)$. By applying the image processing
procedure to the pictures of the agglomeration particles constructed following
the algorithm, we show that $\delta_{agg}$ statistically reproduces the
agglomeration parameter $\gamma_{agg}$.

categories: cs.CE math-ph math.AT math.MP math.NA math.PR


title:
Correction of Doi-Edwards' Green Function for a Chain in a Harmonic
  Potential and its Implication for the Stress-Optical Rule

abstract:
  We provide a corrected Green's function for a polymer chain trapped in a
two-dimensional anisotropic harmonic potential with a fixed boundary condition.
This Green's function is a modified version of what Doi and Edwards first
derived to describe the polymer chain confined in the tube-like domain of
surrounding entangled polymers [J. Chem. Soc. Farad. Trans. II 74 (1978) 1802].
In contradiction to the results found by Ianniruberto and Marrucci (IM) when
applying the Doi-Edwards Green function [J. Non-Newtonian Fluid Mech. 79 (1998)
225], we find that the stress-optical rule is violated for any tube potential
either circular or elliptic if the corrected Green's function is used. The
violation is due to the presence of the virtual springs to confine the chain in
the tube rather than the anisotropy of the confinement potential. On the other
hand, Doi and Edwards used their Green's function only for estimation of the
monomer density along the primitive path where we find just a small correction.
Since they did not use it for rheological calculations, the stress-optic rule
appears to be safe for the Doi-Edwards model.


title: Are there infinitely many decompositions of the nucleon spin ?

abstract:
  We discuss the uniqueness or non-uniqueness problem of the decomposition of
the gluon field into the physical and pure-gauge components, which is the basis
of the recently proposed two physically inequivalent gauge-invariant
decompositions of the nucleon spin. It is crucialy important to recognize the
fact that the standard gauge fixing procedure is essentially a process of
projecting out the physical components of the massless gauge field. A
complexity of the nonabelian gauge theory as compared with the abelian case is
that a closed expression for the physical component can be given only with use
of the non-local Wilson line, which is generally path-dependent. It is known
that, by choosing an infinitely long straight-line path in space and time, the
direction of which is characterized by a constant 4-vector $n^\mu$, one can
cover a class of gauge called the general axial gauge, containing three popular
gauges, i.e. the temporal, the light-cone, and the spatial axial gauge. Within
this general axial gauge, we have calculated the 1-loop evolution matrix for
the quark and gluon longitudinal spins in the nucleon. We found that the final
answer is exactly the same independently of the choices of $n^\mu$, which
amounts to proving the gauge-independence and path-independence simultaneously,
although within a restricted class of gauges and paths. By drawing on all of
these findings together with well-established knowledge from gauge theories, we
argue against the rapidly spreading view in the community that there are
infinitely many decompositions of the nucleon spin.


title: Constructing Polar Codes Using Iterative Bit-Channel Upgrading

abstract:
  The definition of polar codes given by Arikan is explicit, but the
construction complexity is an issue. This is due to the exponential growth in
the size of the output alphabet of the bit-channels as the codeword length
increases. Tal and Vardy recently presented a method for constructing polar
codes which controls this growth. They approximated each bit-channel with a
better channel and a worse channel while reducing the alphabet size. They
constructed a polar code based on the worse channel and used the better channel
to measure the distance from the optimal channel. This paper considers the
knowledge gained from the perspective of the better channel. A method is
presented using iterative upgrading of the bit-channels which successively
results in a channel closer to the original one. It is shown that this approach
can be used to obtain a channel arbitrarily close to the original channel, and
therefore to the optimal construction of a polar code.


title: On the zeros of the Macdonald functions

abstract:
  We are concerned with the zeros of the Macdonald functions or the modified
Bessel functions of the second kind with real index. By using the explicit
expressions for the algebraic equations satisfied by the zeros, we describe the
behavior of the zeros when the index moves. Results by numerical computations
are also presented.


title: Superconductivity induced by U-doping in the SmFeAsO system

abstract:
  Through partial substitution of Sm by U in SmFeAsO, a different member of the
family of iron-based superconductors was successfully synthesized. X-ray
diffraction measurements show that the lattice constants along the a and c axes
are both squeezed through U doping, indicating a successful substitution of U
at the Sm site. The parent compound shows a strong resistivity anomaly near 150
K, associated with spin-density-wave instability.U doping suppresses this
instability and leads to a transition to the superconducting state at
temperatures up to 49 K. Magnetic measurements confirm the bulk
superconductivity in this system. For the sample with a doping level of x =
0.2, the external magnetic field suppresses the onset temperature very slowly,
indicating a rather high upper critical field. In addition, the Hall effect
measurements show that U clearly dopes electrons into the material.


title: Noncommutative Quantum Gravity

abstract:
  We discuss the BRST and anti-BRST symmetries for perturbative quantum gravity
in noncommutative spacetime. In this noncommutative perturbative quantum
gravity the sum of the classical Lagrangian density with a gauge fixing term
and a ghost term is shown to be invariant the noncommutative BRST and the
noncommutative anti-BRST transformations. We analyse the gauge fixing term and
the ghost term in both linear as well as non-linear gauges. We also discuss the
unitarity evolution of the theory and analyse the violation of unitarity of by
introduction of a bare mass term in the noncommutative BRST and the
noncommutative anti-BRST transformations.


title:
Stacking and electric field effects on the electronic properties of the
  layered GaN

abstract:
  Stability and electronic properties of atomic layers of GaN are investigated
in the framework of the van der Waals-density functional theory. We find that
the ground state of the layered GaN is a planar graphene-like configuration
rather than a buckled bulk-like configuration. Application of an external
perpendicular electric field to the layered GaN induces distinct
stacking-dependent features of the tunability of the band gap; the band gap of
the monolayer does not change whereas that of the trilayer GaN is significantly
reduced for the applied field of 0.4 V/ {\AA}. It is suggested that such a
stacking-dependent tunability of the band gap in the presence of an applied
field may lead to novel applications of the devices based on the layered GaN.


title:
An Efficient Detection Mechanism for Distributed Denial of Service
  (DDoS) Attack

abstract:
  Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks have
emerged as a popular means of causing collection particular overhaul
disruptions, often for total periods of instance. The relative ease and low
costs of initiation such attacks, supplemented by the present insufficient sate
of any feasible defense method, have made them one of the top threats to the
Internet centre of population nowadays. Since the rising attractiveness of
web-based applications has led to quite a lot of significant services being
provided more than the Internet, it is very important to monitor the network
transfer so as to stop hateful attackers from depleting the assets of the
network and denying services to rightful users. The most important drawbacks of
the presently existing defense mechanisms and propose a new-fangled mechanism
for defending a web-server against a DDoS attack. In the proposed mechanism,
incoming traffic to the server is always monitored and some irregular rise in
the inbound traffic is without delay detected. The detection algorithm is based
on a statistical analysis of the inbound traffic on the server and a robust
suggestion testing structure. While the detection procedure is on, the sessions
from the rightful sources are not disrupted and the load on the server is
restored to the usual level by overcrowding the traffic from the attacking
sources. The accurate modules employ multifaceted detection logic and hence
involve additional overhead for their execution. On the other hand, they have
very huge detection accuracy. Simulations approved on the proposed mechanism
have produced results that show efficiency of the proposed defense mechanism
against DDoS attacks.


title: Properly embedded, area-minimizing surfaces in hyperbolic $3$-space

abstract:
  We prove prove a bridge principle at infinity for area-minimizing surfaces in
the hyperbolic space $\mathbb{H}^3$, and we use it to prove that any open,
connected, orientable surface can be properly embedded in $\mathbb{H}^3$ as an
area-minimizing surface. Moreover, the embedding can be constructed in such a
way that the limit sets of different ends are disjoint.


title: ATCA survey of water masers in the Large Magellanic Cloud

abstract:
  We have analysed archival data taken with the Australia Telescope Compact
Array (ATCA) during 2001--2003 and detected nine new interstellar and
circumstellar water masers in the LMC. This takes the total number of star
formation water masers in the LMC to 23, spread over 14 different star forming
regions and three evolved stars. Three water maser sources (N105a/MC23,
N113/MC24, N157a/MC74) have been detected in all the previous observations that
targeted these sites, although all show significant variability on timescales
of decades. The total number of independent water maser sources now known in
the LMC means that through very long baseline interferometry astrometric
measurements it will be possible to construct a more precise model of the
galactic rotation of the LMC and its orbital motion around the Milky Way
Galaxy.


title: Verifying PRAM Consistency over Read/Write Traces of Data Replicas

abstract:
  Data replication technologies enable efficient and highly-available data
access, thus gaining more and more interests in both the academia and the
industry. However, data replication introduces the problem of data consistency.
Modern commercial data replication systems often provide weak consistency for
high availability under certain failure scenarios. An important weak
consistency is Pipelined-RAM (PRAM) consistency. It allows different processes
to hold different views of data. To determine whether a data replication system
indeed provides PRAM consistency, we study the problem of Verifying PRAM
Consistency over read/write traces (or VPC, for short).
  We first identify four variants of VPC according to a) whether there are
Multiple shared variables (or one Single variable), and b) whether write
operations can assign Duplicate values (or only Unique values) for each shared
variable; the four variants are labeled VPC-SU, VPC-MU, VPC-SD, and VPC-MD.
Second, we present a simple VPC-MU algorithm, called RW-CLOSURE. It constructs
an operation graph $\mathcal{G}$ by iteratively adding edges according to three
rules. Its time complexity is $O(n^5)$, where n is the number of operations in
the trace. Third, we present an improved VPC-MU algorithm, called READ-CENTRIC,
with time complexity $O(n^4)$. Basically it attempts to construct the operation
graph $\mathcal{G}$ in an incremental and efficient way. Its correctness is
based on that of RW-CLOSURE. Finally, we prove that VPC-SD (so is VPC-MD) is
$\sf{NP}$-complete by reducing the strongly $\sf{NP}$-complete problem
3-PARTITION to it.


title: On CCC-predicted concentric low-variance circles in the CMB sky

abstract:
  A new analysis of the CMB, using WMAP data, supports earlier indications of
non-Gaussian features of concentric circles of low temperature variance.
Conformal cyclic cosmology (CCC) predicts such features from supermassive
black-hole encounters in an aeon preceding our Big Bang. The significance of
individual low-variance circles in the true data has been disputed; yet a
recent independent analysis has confirmed CCC's expectation that CMB circles
have a non-Gaussian temperature distribution. Here we examine concentric sets
of low-variance circular rings in the WMAP data, finding a highly non-isotropic
distribution. A new "sky-twist" procedure, directly analysing WMAP data,
without appeal to simulations, shows that the prevalence of these concentric
sets depends on the rings being circular, rather than even slightly elliptical,
numbers dropping off dramatically with increasing ellipticity. This is
consistent with CCC's expectations; so also is the crucial fact that whereas
some of the rings' radii are found to reach around $15^\circ$, none exceed
$20^\circ$. The non-isotropic distribution of the concentric sets may be linked
to previously known anomalous and non-Gaussian CMB features.


title: Geodesic motion in General Relativity: LARES in Earth's gravity

abstract:
  According to General Relativity, as distinct from Newtonian gravity, motion
under gravity is treated by a theory that deals, initially, only with test
particles. At the same time, satellite measurements deal with extended bodies.
We discuss the correspondence between geodesic motion in General Relativity and
the motion of an extended body by means of the Ehlers-Geroch theorem, and in
the context of the recently launched LAser RElativity Satellite (LARES). Being
possibly the highest mean density orbiting body in the Solar system, this
satellite provides the best realization of a test particle ever reached
experimentally and provides a unique possibility for testing the predictions of
General Relativity.


title:
Direct measurement results of the time lag of LOS-velocity oscillations
  between two heights in solar faculae and sunspots

abstract:
  We present an investigation of line-of-sight (LOS) velocity oscillations in
solar faculae and sunspots. To study the phase relations between chromosphere
and photosphere oscillations of the LOS velocity, we measured the time lag of
the chromospheric signal relative to the photospheric one for several faculae
and sunspots in a set of spectral line pairs. The measured time lags are
different for different objects. The mean measured delay between the
oscillations in the five-minute band in faculae is 50s for the SiI
10827{\AA}-HeI 10830{\AA} pair; for the pair FeI 6569{\AA}-H-alpha 6563{\AA}
the mean delay is 20s; for the pair FeI 4551{\AA}-BaII 4554{\AA} the mean delay
is 7s; for the pair SiI 8536{\AA}-CaII 8542{\AA} the mean delay is 20s. For the
oscillations in the three-minute band in sunspot umbrae the mean delay is 55s
for the SiI 10827{\AA}-HeI 10830{\AA} pair; for the Fe I 6569{\AA}-H-alpha
6563{\AA} pair it was not possible to determine the delay; for the FeI
4551{\AA}-BaII 4554{\AA} pair the mean delay is 6s; for the SiI 8536{\AA}-CaII
8542{\AA} pair the mean delay is 21s. Measured delays correspond to the wave
propagation speed which significantly exceeds the generally adopted speed of
sound in the photosphere. This raises the question of the origin of these
oscillations. The possibility that we deal with slow MHD waves is not ruled
out.


title: On the time arrows, and randomness in cosmological signals

abstract:
  Arrows of time - thermodynamical, cosmological, electromagnetic, quantum
mechanical, psychological - are basic properties of Nature. For a quantum
system-bath closed system the de-correlated initial conditions and no-memory
(Markovian) dynamics are outlined as necessary conditions for the appearance of
the thermodynamical arrow. The emergence of the arrow for the system evolving
according to non-unitary dynamics due to the presence of the bath, then, is a
result of limited observability, and we conjecture the arrow in the observable
Universe as determined by the dark sector acting as a bath. The voids in the
large scale matter distribution induce hyperbolicity of the null geodesics,
with possible observational consequences.


title: Rate-Compatible Short-Length Protograph LDPC Codes

abstract:
  This paper produces a rate-compatible protograph LDPC code at 1k information
blocklength with superior performance in both waterfall and error floor
regions. The design of such codes has proved difficult in the past because the
constraints imposed by structured design (protographs), rate-compatibility, as
well as small block length, are not easily satisfied together. For example, as
the block length decreases, the predominance of decoding threshold as the main
parameter in coding design is reduced, thus complicating the search for good
codes. Our rate-compatible protograph codes have rates ranging from 1/3 to 4/5
and show no error floor down to $10^{-6}$ FER.


title:
Determining accurate measurements of the growth rate from the galaxy
  correlation function in simulations

abstract:
  We use high-resolution N-body simulations to develop a new, flexible,
empirical approach for measuring the growth rate from redshift-space
distortions (RSD) in the 2-point galaxy correlation function. We quantify the
systematic error in measuring the growth rate in a $1 \, h^{-3}$ Gpc$^3$ volume
over a range of redshifts, from the dark matter particle distribution and a
range of halo-mass catalogues with a number density comparable to the latest
large-volume galaxy surveys such as the WiggleZ Dark Energy Survey and the
Baryon Oscillation Spectroscopic Survey (BOSS). Our simulations allow us to
span halo masses with bias factors ranging from unity (probed by emission-line
galaxies) to more massive haloes hosting Luminous Red Galaxies. We show that
the measured growth rate is sensitive to the model adopted for the small-scale
real-space correlation function, and in particular that the "standard"
assumption of a power-law correlation function can result in a significant
systematic error in the growth rate determination. We introduce a new,
empirical fitting function that produces results with a lower (5-10%) amplitude
of systematic error. We also introduce a new technique which permits the galaxy
pairwise velocity distribution, the quantity which drives the non-linear growth
of structure, to be measured as a non-parametric stepwise function. Our
(model-independent) results agree well with an exponential pairwise velocity
distribution, expected from theoretical considerations, and are consistent with
direct measurements of halo velocity differences from the parent catalogues. In
a companion paper we present the application of our new methodology to the
WiggleZ Survey dataset.


title: q-ary Compressive Sensing

abstract:
  We introduce q-ary compressive sensing, an extension of 1-bit compressive
sensing. We propose a novel sensing mechanism and a corresponding recovery
procedure. The recovery properties of the proposed approach are analyzed both
theoretically and empirically. Results in 1-bit compressive sensing are
recovered as a special case. Our theoretical results suggest a tradeoff between
the quantization parameter q, and the number of measurements m in the control
of the error of the resulting recovery algorithm, as well its robustness to
noise.


title: Extensible Technology-Agnostic Runtime Verification

abstract:
  With numerous specialised technologies available to industry, it has become
increasingly frequent for computer systems to be composed of heterogeneous
components built over, and using, different technologies and languages. While
this enables developers to use the appropriate technologies for specific
contexts, it becomes more challenging to ensure the correctness of the overall
system. In this paper we propose a framework to enable extensible technology
agnostic runtime verification and we present an extension of polyLarva, a
runtime-verification tool able to handle the monitoring of
heterogeneous-component systems. The approach is then applied to a case study
of a component-based artefact using different technologies, namely C and Java.


title:
Sequence Diagram Test Case Specification and Virtual Integration
  Analysis using Timed-Arc Petri Nets

abstract:
  In this paper, we formally define Test Case Sequence Diagrams (TCSD) as an
easy-to-use means to specify test cases for components including timing
constraints. These test cases are modeled using the UML2 syntax and can be
specified by standard UML-modeling-tools. In a component-based design an early
identification of errors can be achieved by a virtual integration of components
before the actual system is build. We define such a procedure which integrates
the individual test cases of the components according to the interconnections
of a given architecture and checks if all specified communication sequences are
consistent. Therefore, we formally define the transformation of TCSD into
timed-arc Petri nets and a process for the combination of these nets. The
applicability of our approach is demonstrated on an avionic use case from the
ARP4761 standard.


title:
Software model refactoring based on performance analysis: better working
  on software or performance side?

abstract:
  Several approaches have been introduced in the last few years to tackle the
problem of interpreting model-based performance analysis results and
translating them into architectural feedback. Typically the interpretation can
take place by browsing either the software model or the performance model. In
this paper, we compare two approaches that we have recently introduced for this
goal: one based on the detection and solution of performance antipatterns, and
another one based on bidirectional model transformations between software and
performance models. We apply both approaches to the same example in order to
illustrate the differences in the obtained performance results. Thereafter, we
raise the level of abstraction and we discuss the pros and cons of working on
the software side and on the performance side.


title:
Validity of Hydrostatic Equilibrium in Galaxy Clusters from Cosmological
  Hydrodynamical Simulations

abstract:
  We examine the validity of the hydrostatic equilibrium (HSE) assumption for
galaxy clusters using one of the highest-resolution cosmological hydrodynamical
simulations. We define and evaluate several effective mass terms corresponding
to the Euler equations of the gas dynamics, and quantify the degree of the
validity of HSE in terms of the mass estimate. We find that the mass estimated
under the HSE assumption (the HSE mass) deviates from the true mass by up to ~
30 %. This level of departure from HSE is consistent with the previous claims,
but our physical interpretation is rather different. We demonstrate that the
inertial term in the Euler equations makes a negligible contribution to the
total mass, and the overall gravity of the cluster is balanced by the thermal
gas pressure gradient and the gas acceleration term. Indeed the deviation from
the HSE mass is well explained by the acceleration term at almost all radii. We
also clarify the confusion of previous work due to the inappropriate
application of the Jeans equations in considering the validity of HSE from the
gas dynamics extracted from cosmological hydrodynamical simulations.


title:
Towards a Formal Framework for Mobile, Service-Oriented Sensor-Actuator
  Networks

abstract:
  Service-oriented sensor-actuator networks (SOSANETs) are deployed in
health-critical applications like patient monitoring and have to fulfill strong
safety requirements. However, a framework for the rigorous formal modeling and
analysis of SOSANETs does not exist. In particular, there is currently no
support for the verification of correct network behavior after node failure or
loss/addition of communication links. To overcome this problem, we propose a
formal framework for SOSANETs. The main idea is to base our framework on the
\pi-calculus, a formally defined, compositional and well-established formalism.
We choose KLAIM, an existing formal language based on the \pi-calculus as the
foundation for our framework. With that, we are able to formally model SOSANETs
with possible topology changes and network failures. This provides the basis
for our future work on prediction, analysis and verification of the network
behavior of these systems. Furthermore, we illustrate the real-life
applicability of this approach by modeling and extending a use case scenario
from the medical domain.


title: Assembling the Proofs of Ordered Model Transformations

abstract:
  In model-driven development, an ordered model transformation is a nested set
of transformations between source and target classes, in which each
transformation is governed by its own pre and post- conditions, but
structurally dependent on its parent. Following the
proofs-as-model-transformations approach, in this paper we consider a
formalisation in Constructive Type Theory of the concepts of model and model
transformation, and show how the correctness proofs of potentially large
ordered model transformations can be systematically assembled from the proofs
of the specifications of their parts, making them easier to derive.


title: Towards a Framework for Behavioral Specifications of OSGi Components

abstract:
  We present work on behavioral specifications of OSGi components. Our
behavioral specifications are based on finite automata like formalisms.
Behavioral specifications can be used to find appropriate components to
interact with, detect incompatibilities between communication protocols of
components and potential problems resulting from the interplay of
non-deterministic component specifications. These operations can be carried out
during development and at runtime of a system. Furthermore, we describe work
carried out using the Eclipse based implementation of our framework.


title: Quantum graph spectra of a graphyne structure

abstract:
  We study the dispersion relations and spectra of invariant Schr\"odinger
operators on a graphyne structure (lithographite). In particular, description
of different parts of the spectrum, band-gap structure, and Dirac points are
provided.


title: Online Deliberation Design: Choices, Criteria, and Evidence

abstract:
  This chapter reviews empirical evidence bearing on the design of online
forums for deliberative civic engagement. Dimensions of design are defined for
different aspects of the deliberation: its purpose, the target population, the
spatiotemporal distance separating participants, the communication medium, and
the deliberative process to be followed. After a brief overview of criteria for
evaluating different design options, empirical findings are organized around
design choices. Research has evolved away from treating technology for online
deliberation dichotomously (either present or not) toward nuanced findings that
differentiate between technological features, ways of using them, and cultural
settings. The effectiveness of online deliberation depends on how well the
communicative environment is matched to the deliberative task. Tradeoffs, e.g.
between rich and lean media and between anonymous and identifiable
participation, suggest different designs depending on the purpose and
participants. Findings are limited by existing technologies, and may change as
technologies and users co-evolve.


title:
The WiggleZ Dark Energy Survey: measuring the cosmic growth rate with
  the two-point galaxy correlation function

abstract:
  The growth history of large-scale structure in the Universe is a powerful
probe of the cosmological model, including the nature of dark energy. We study
the growth rate of cosmic structure to redshift $z = 0.9$ using more than
$162{,}000$ galaxy redshifts from the WiggleZ Dark Energy Survey. We divide the
data into four redshift slices with effective redshifts $z =
[0.2,0.4,0.6,0.76]$ and in each of the samples measure and model the 2-point
galaxy correlation function in parallel and transverse directions to the
line-of-sight. After simultaneously fitting for the galaxy bias factor we
recover values for the cosmic growth rate which are consistent with our assumed
$\Lambda$CDM input cosmological model, with an accuracy of around 20% in each
redshift slice. We investigate the sensitivity of our results to the details of
the assumed model and the range of physical scales fitted, making close
comparison with a set of N-body simulations for calibration. Our measurements
are consistent with an independent power-spectrum analysis of a similar
dataset, demonstrating that the results are not driven by systematic errors. We
determine the pairwise velocity dispersion of the sample in a non-parametric
manner, showing that it systematically increases with decreasing redshift, and
investigate the Alcock-Paczynski effects of changing the assumed fiducial model
on the results. Our techniques should prove useful for current and future
galaxy surveys mapping the growth rate of structure using the 2-dimensional
correlation function.


title: A Semple Approach to Goursat: The Multi-Flag Case

abstract:
  In this note we summarize our results from earlier work with the Monster
Tower (A Monster Tower Approach to Goursat Multi-Flags). In particular, we give
an overview of the problem of classifying the orbits within a tower of
fibrations with fibers diffeomorphic to projective planes. Included in this
note is one new result that was not in our previous work.


title:
Convergence Analysis of a Finite Difference Scheme for the Gradient Flow
  associated with the ROF Model

abstract:
  We present a convergence analysis of a finite difference scheme for the time
dependent partial different equation called gradient flow associated with the
Rudin-Osher-Fatemi model. We devise an iterative algorithm to compute the
solution of the finite difference scheme and prove the convergence of the
iterative algorithm. Finally computational experiments are shown to demonstrate
the convergence of the finite difference scheme. An application for image
denoising is given.


title: Basic Classes of Grammars with Prohibition

abstract:
  A practical tool for natural language modeling and development of
human-machine interaction is developed in the context of formal grammars and
languages. A new type of formal grammars, called grammars with prohibition, is
introduced. Grammars with prohibition provide more powerful tools for natural
language generation and better describe processes of language learning than the
conventional formal grammars. Here we study relations between languages
generated by different grammars with prohibition based on conventional types of
formal grammars such as context-free or context sensitive grammars. Besides, we
compare languages generated by different grammars with prohibition and
languages generated by conventional formal grammars. In particular, it is
demonstrated that they have essentially higher computational power and
expressive possibilities in comparison with the conventional formal grammars.
Thus, while conventional formal grammars are recursive and subrecursive
algorithms, many classes of grammars with prohibition are superrecursive
algorithms. Results presented in this work are aimed at the development of
human-machine interaction, modeling natural languages, empowerment of
programming languages, computer simulation, better software systems, and theory
of recursion.


title: Synthesis of Topological Quantum Circuits

abstract:
  Topological quantum computing has recently proven itself to be a very
powerful model when considering large- scale, fully error corrected quantum
architectures. In addition to its robust nature under hardware errors, it is a
software driven method of error corrected computation, with the hardware
responsible for only creating a generic quantum resource (the topological
lattice). Computation in this scheme is achieved by the geometric manipulation
of holes (defects) within the lattice. Interactions between logical qubits
(quantum gate operations) are implemented by using particular arrangements of
the defects, such as braids and junctions. We demonstrate that junction-based
topological quantum gates allow highly regular and structured implementation of
large CNOT (controlled-not) gate networks, which ultimately form the basis of
the error corrected primitives that must be used for an error corrected
algorithm. We present a number of heuristics to optimise the area of the
resulting structures and therefore the number of the required hardware
resources.


title: On the world cognizability

abstract:
  The paper gives a few examples of the phenomena that will never be understood
by the mankind. The first example is the physics at the scales of $\sim
10^{-33}$ cm where the gravitation interaction becomes strong, sales at the
very beginning of the Big Bang. It argues that the mankind will never establish
the laws that controls the events at these scales. Further, it is supposed that
the time dependence of the entropy, which determine the direction of the time
arrow, originates at the same time scale and, thus, the nature of the time
arrow will be never established either. Finally, I conjecture that the brain
cells are controlled by quantum computer with the very large (or even infinite)
number of degenerate states. An external observation destroys this degeneracy,
leading to impossibility to understand the mechanism of the conscience.


title:
Electric field and photo-excited control of the carrier concentration in
  GdN

abstract:
  We present both electric-field and photo-excited control of the carrier
concentration in GdN. There is no evidence in the results of a carrier-mediated
contribution to the Gd-Gd exchange interaction that has been suggested to
explain a measured Curie temperature that is much higher than obtained within
theoretical treatments. Persistent carrier concentrations seen in both the
field-effect and photo-induced conductivities point to a distribution of
long-lived trap states below the conduction band, very likely centred at
nitrogen vacancies


title: Finite-size effect in shot noise in hopping conduction

abstract:
  We study a current shot noise in a macroscopic insulator based on a
two-dimensional electron system in GaAs in a variable range hopping (VRH)
regime. At low temperature and in a sufficiently depleted sample a shot noise
close to a full Poissonian value is measured. This suggests an observation of a
finite-size effect in shot noise in the VRH conduction and demonstrates a
possibility of accurate quasiparticle charge measurements in the insulating
regime.


title: Unsupervised edge map scoring: a statistical complexity approach

abstract:
  We propose a new Statistical Complexity Measure (SCM) to qualify edge maps
without Ground Truth (GT) knowledge. The measure is the product of two indices,
an \emph{Equilibrium} index $\mathcal{E}$ obtained by projecting the edge map
into a family of edge patterns, and an \emph{Entropy} index $\mathcal{H}$,
defined as a function of the Kolmogorov Smirnov (KS) statistic.
  This new measure can be used for performance characterization which includes:
(i)~the specific evaluation of an algorithm (intra-technique process) in order
to identify its best parameters, and (ii)~the comparison of different
algorithms (inter-technique process) in order to classify them according to
their quality.
  Results made over images of the South Florida and Berkeley databases show
that our approach significantly improves over Pratt's Figure of Merit (PFoM)
which is the objective reference-based edge map evaluation standard, as it
takes into account more features in its evaluation.


title: Hearts of twin cotorsion pairs on exact categories

abstract:
  In the papers of Nakaoka, he introduced the notion of hearts of (twin)
cotorsion pairs on triangulated categories and showed that they have structures
of (semi-) abelian categories. We study in this article a twin cotorsion pair
(S,T),(U,V) on an exact category B with enough projectives and injectives and
introduce a notion of the heart. First we show that its heart is preabelian.
Moreover we show the heart of a single cotorsion pair is abelian. These results
are analog of Nakaoka's results in triangulated categories. We also consider
special cases where the heart has nicer structure. By our results, the heart of
a special twin cotorsion pair (S,T),(T,V), is integral and almost abelian.
Finally we show that the Gabriel-Zisman localisation of the heart at the class
of regular morphisms is abelian, and moreover it is equivalent to the category
of finitely presented modules over a stable subcategory of B.


title: The Heegaard distances cover all non-negative integers

abstract:
  In this paper, we prove that
  (1) For any integers $n\geq 1$ and $g\geq 2$, there is a closed 3-manifold
$M_{g}^{n}$ which admits a distance $n$ Heegaard splitting of genus $g$ except
that the pair of $(g, n)$ is $(2, 1)$. Furthermore, $M_{g}^{n}$ can be chosen
to be hyperbolic except that the pair of $(g, n)$ is $(3, 1)$.
  (2) For any integers $g\geq 2$ and $n\geq 4$, there are infinitely many
non-homeomorphic closed 3-manifolds admitting distance $n$ Heegaard splittings
of genus $g$.


title: Object Detection in Real Images

abstract:
  Object detection and recognition are important problems in computer vision.
Since these problems are meta-heuristic, despite a lot of research, practically
usable, intelligent, real-time, and dynamic object detection/recognition
methods are still unavailable. We propose a new object detection/recognition
method, which improves over the existing methods in every stage of the object
detection/recognition process. In addition to the usual features, we propose to
use geometric shapes, like linear cues, ellipses and quadrangles, as additional
features. The full potential of geometric cues is exploited by using them to
extract other features in a robust, computationally efficient, and less
meta-heuristic manner. We also propose a new hierarchical codebook, which
provides good generalization and discriminative properties. The codebook
enables fast multi-path inference mechanisms based on propagation of
conditional likelihoods, that make it robust to occlusion and noise. It has the
capability of dynamic learning. We also propose a new learning method that has
generative and discriminative learning capabilities, does not need large and
fully supervised training dataset, and is capable of online learning. The
preliminary work of detecting geometric shapes in real images has been
completed. This preliminary work is the focus of this report. Future path for
realizing the proposed object detection/recognition method is also discussed in
brief.


title:
Driving Perpendicular Heat Flow: Ambipolar Transverse Thermoelectrics
  for Microscale and Cryogenic Peltier Cooling

abstract:
  Whereas thermoelectric performance is normally limited by the figure of merit
ZT, transverse thermoelectrics can achieve arbitrarily large temperature
differences in a single leg even with inferior ZT by being geometrically
tapered. We introduce a band-engineered transverse thermoelectric with p-type
Seebeck in one direction and n-type orthogonal, resulting in off-diagonal terms
that drive heat flow transverse to electrical current. Such materials are
advantageous for microscale devices and cryogenic temperatures -- exactly the
regimes where standard longitudinal thermoelectrics fail. InAs/GaSb type II
superlattices are shown to have the appropriate band structure for use as a
transverse thermoelectric.


title: A non-self-adjoint Lebesgue decomposition

abstract:
  We study the structure of bounded linear functionals on a class of
non-self-adjoint operator algebras that includes the multiplier algebra of
every complete Nevanlinna-Pick space, and in particular the multiplier algebra
of the Drury-Arveson space. Our main result is a Lebesgue decomposition
expressing every linear functional as the sum of an absolutely continuous (i.e.
weak-* continuous) linear functional, and a singular linear functional that is
far from being absolutely continuous. This is a non-self-adjoint analogue of
Takesaki's decomposition theorem for linear functionals on von Neumann
algebras. We apply our decomposition theorem to prove that the predual of every
algebra in this class is (strongly) unique.


title:
The CORE Storage Primitive: Cross-Object Redundancy for Efficient Data
  Repair & Access in Erasure Coded Storage

abstract:
  Erasure codes are an integral part of many distributed storage systems aimed
at Big Data, since they provide high fault-tolerance for low overheads.
However, traditional erasure codes are inefficient on reading stored data in
degraded environments (when nodes might be unavailable), and on replenishing
lost data (vital for long term resilience). Consequently, novel codes optimized
to cope with distributed storage system nuances are vigorously being
researched. In this paper, we take an engineering alternative, exploring the
use of simple and mature techniques -juxtaposing a standard erasure code with
RAID-4 like parity. We carry out an analytical study to determine the efficacy
of this approach over traditional as well as some novel codes. We build upon
this study to design CORE, a general storage primitive that we integrate into
HDFS. We benchmark this implementation in a proprietary cluster and in EC2. Our
experiments show that compared to traditional erasure codes, CORE uses 50% less
bandwidth and is up to 75% faster while recovering a single failed node, while
the gains are respectively 15% and 60% for double node failures.


title: Global Asymptotics of Stieltjes-Wigert Polynomials

abstract:
  Asymptotic formulas are derived for the Stieltjes-Wigert polynomials
$S_n(z;q)$ in the complex plane as the degree $n$ grows to infinity. One
formula holds in any disc centered at the origin, and the other holds outside
any smaller disc centered at the origin; the two regions together cover the
whole plane. In each region, the $q$-Airy function $A_q(z)$ is used as the
approximant. For real $x> 1/4$, a limiting relation is also established between
the $q$-Airy function $A_q(x)$ and the ordinary Airy function $\mathrm{Ai}(x)$
as $q \to 1$.


title: On log canonical rings

abstract:
  We discuss the relationship among various conjectures in the minimal model
theory including the finite generation conjecture of the log canonical rings
and the abundance conjecture. In particular, we show that the finite generation
conjecture of the log canonical rings for log canonical pairs can be reduced to
that of the log canonical rings for purely log terminal pairs of log general
type.


title:
Strategic Advantage in Web Tourism Promotion: An e-Commerce Strategy for
  Developing Countries

abstract:
  This research informs the means to develop an e-commerce strategy for web
based tourism promotion of hotels located in developing countries. The study
explored the aspects related to the use of information systems in web based
tourism promotion, along with a focus on the organizational factors affecting
the use of e-commerce strategy. Interviews were conducted with the managers of
selected five sample hotels located in Sri Lanka. A structured web content
analysis was undertaken for all five sample hotels to trace process level data
on the e-commerce web content. Specific aspects of web content analysis include
interactivity, trust, information and value adding features. Instrument for web
content analysis was developed by the researcher. The outcome of research
produces an outline for developing an e-commerce strategy for hotels located in
developing countries to achieve strategic advantages in web based tourism
promotion.


title:
Critical Success Factors for Positive User Experience in Hotel Websites:
  Applying Herzberg's Two Factor Theory for User Experience Modeling

abstract:
  This research presents the development of a critical success factor matrix
for increasing positive user experience of hotel websites based upon user
ratings. Firstly, a number of critical success factors for web usability have
been identified through the initial literature review. Secondly, hotel websites
were surveyed in terms of critical success factors identified through the
literature review. Thirdly, Herzberg's motivation theory has been applied to
the user rating and the critical success factors were categorized into two
areas. Finally, the critical success factor matrix has been developed using the
two main sets of data.


title: Stellar theory for flag complexes

abstract:
  Refining a basic result of Alexander, we show that two flag simplicial
complexes are piecewise linearly homeomorphic if and only if they can be
connected by a sequence of flag complexes, each obtained from the previous one
by either an edge subdivision or its inverse. For flag spheres we pose new
conjectures on their combinatorial structure forced by their face numbers,
analogous to the extremal examples in the upper and lower bound theorems for
simplicial spheres. Furthermore, we show that our algorithm to test the
conjectures searches through the entire space of flag PL spheres of any given
dimension.


title:
Implications for Improving Accessibility to E-Commerce Websites in
  Developing Countries: A Subjective Study of Sri Lankan Hotel Websites

abstract:
  This research explores the accessibility issues with regard to the e-commerce
websites in developing countries, through a subjective study of Sri Lankan
hotel websites. A web survey and a web content analysis were conducted as the
methods to elicit data on web accessibility. Factors preventing accessibility
were hypothesized as an initial experiment. Hazardous design elements are
identified through web content analysis, the results of which are utilized to
develop specific implications for improving web accessibility. The hypothesis
tests show that there is no significant correlation between accessibility and
geographical or economic factors. However, physical impairments of users have a
considerable influence on the accessibility. Especially, visual and mobility
impaired users experience poor accessibility. Poor readability and less
navigable page designs are two observable issues, which pose threats to
accessibility. The lack of conformance to W3C accessibility guidelines and the
poor design process are the specific shortcomings which reduce the overall
accessibility. Guidelines aim to improve the accessibility of sites with a
strategic focus. Further enhancements are suggested with adherence to
principles and user centered design and developing customizable web portals
compatible for connections with differing speeds. A need for developing new
design models for differencing user groups and implementing web accessibility
strategy are emphasized as vital steps towards effective information
dissemination via e-commerce websites in the developing countries.


title:
A Virtual World Model to Enhance Tourism Destination Accessibility in
  Developing Countries

abstract:
  The problem of destination accessibility is a vital concern in the
sustainable tourism development in the emerging regions due to the increasing
numbers of tourism business growth in the recent times. Tourism is one of the
potential foreign exchange earning sectors, which place sustainability as one
of the main success metrics for benchmarking the industry's overall
development. On the other hand, there are several destinations, which are
inaccessible to tourists due to several reasons. Underutilization of potential
destinations in both pre purchase and consumption stages is a strategic
disadvantage for emerging countries on leading their tourism industry towards
sustainability. A virtual world model to increase the destination accessibility
of tourism products has been proposed. The model has to be designed with visual
and auditory experience to tourists. The model is expected to enhance the
accessibility of destinations for users of different categories. Elderly users,
users with panic disorders, users with mobility impairments also will be able
to enjoy traveling experience just same as other, through the proposed model.


title:
A Proposal To Support Wellbeing in People With Borderline Personality
  Disorder: Applying Reminiscent Theory in a Mobile App

abstract:
  In this paper the research draws upon reminiscence therapy, which is used in
treating dementia, as an applied theory to promote well being in people who
experience low moods. The application proposed here aims to promote wellbeing
for people suffering from mood disorders and dementia but could potentially be
used to enhance wellbeing for many types of users. Use of the application is
anticipated to improve mood in a group of users where severe emotional problems
are prevalent. The research aims to evaluate the effectiveness of a
reminiscence based application in promoting well being in people specifically
with Borderline Personality Disorder (BPD). The long term objective of this
research is to establish the effectiveness of reminiscence theory on user
groups aside from dementia, particularly other mental illnesses. The research
advocates involving end users within the design process both to inform and
evaluate the development of a mobile and tablet application.


title: Spectral modelling of massive binary systems

abstract:
  Aims: We simulate the spectra of massive binaries at different phases of the
orbital cycle, accounting for the gravitational influence of the companion star
on the shape and physical properties of the stellar surface. Methods: We used
the Roche potential modified to account for radiation pressure to compute the
stellar surface of close circular systems and we used the TIDES code for
surface computation of eccentric systems. In both cases, we accounted for
gravity darkening and mutual heating generated by irradiation to compute the
surface temperature. We then interpolated NLTE plane-parallel atmosphere model
spectra in a grid to obtain the local spectrum at each surface point. We
finally summed all contributions, accounting for the Doppler shift,
limb-darkening, and visibility to obtain the total synthetic spectrum. We
computed different orbital phases and sets of physical and orbital parameters.
Results: Our models predict line strength variations through the orbital cycle,
but fail to completely reproduce the Struve-Sahade effect. Including radiation
pressure allows us to reproduce a surface temperature distribution that is
consistent with observations of semi-detached binary systems. Conclusions:
Radiation pressure effects on the stellar surface are weak in (over)contact
binaries and well-detached systems but can become very significant in
semi-detached systems. The classical von Zeipel theorem is sufficient for the
spectral computation. Broad-band light curves derived from the spectral
computation are different from those computed with a model in which the stellar
surfaces are equipotentials of the Roche potential scaled by the instantaneous
orbital separation. In many cases, the fit of two Gaussian/Lorentzian profiles
fails to properly measure the equivalent width of the lines and leads to
apparent variations that could explain some of the effects reported in the
literature.


title:
Estimation of integrated covariances in the simultaneous presence of
  nonsynchronicity, microstructure noise and jumps

abstract:
  We propose a new estimator for the integrated covariance of two Ito
semimartingales observed at a high-frequency. This new estimator, which we call
the pre-averaged truncated Hayashi-Yoshida estimator, enables us to separate
the sum of the co-jumps from the total quadratic covariation even in the case
that the sampling schemes of two processes are nonsynchronous and the
observation data is polluted by some noise. It is the first estimator which can
simultaneously handle these three issues, which are fundamental to empirical
studies of high-frequency financial data. We also show the asymptotic mixed
normality of this estimator under some mild conditions allowing infinite
activity jump processes with finite variations, some dependency between the
sampling times and the observed processes as well as a kind of endogenous
observation errors. We examine the finite sample performance of this estimator
using a Monte Carlo study.


title:
Vector magnetic field sensing by single nitrogen vacancy center in
  diamond

abstract:
  In this Letter, we proposed and experimentally demonstrated a method to
detect vector magnetic field with a single nitrogen vacancy (NV) center in
diamond. The magnetic field in parallel with the axis of the NV center can be
obtained by detecting the electron Zeeman shift, while the Larmor precession of
an ancillary nuclear spin close to the NV center can be used to measure the
field perpendicular to the axis. Experimentally, both the Zeeman shift and
Larmor precession can be measured through the fluorescence from the NV center.
By applying additional calibrated magnetic fields, complete information of the
vector magnetic field can be achieved with such a method. This vector magnetic
field detection method is insensitive to temperature fluctuation and it can be
applied to nanoscale magnetic measurement.


title: Cellularity of the lowest two-sided ideal of an affine Hecke algebra

abstract:
  In this paper we show that the lowest two-sided ideal of an affine Hecke
algebra is affine cellular for all choices of parameters. We explicitely
describe the cellular basis and we show that the basis elements have a nice
decomposition when expressed in the Kazhdan-Lusztig basis. In type $A$ we
provide a combinatorial description of this decomposition in term of number of
paths.


title: The exponential family in abstract information theory

abstract:
  We introduce generalized notions of a divergence function and a Fisher
information matrix. We propose to generalize the notion of an exponential
family of models by reformulating it in terms of the Fisher information matrix.
Our methods are those of information geometry. The context is general enough to
include applications from outside statistics.


title: Lookahead Strategies for Sequential Monte Carlo

abstract:
  Based on the principles of importance sampling and resampling, sequential
Monte Carlo (SMC) encompasses a large set of powerful techniques dealing with
complex stochastic dynamic systems. Many of these systems possess strong
memory, with which future information can help sharpen the inference about the
current state. By providing theoretical justification of several existing
algorithms and introducing several new ones, we study systematically how to
construct efficient SMC algorithms to take advantage of the "future"
information without creating a substantially high computational burden. The
main idea is to allow for lookahead in the Monte Carlo process so that future
information can be utilized in weighting and generating Monte Carlo samples, or
resampling from samples of the current state.


title: Electrical conductivity measured in atomic carbon chains

abstract:
  The first electrical conductivity measurements of monoatomic carbon chains
are reported in this study. The chains were obtained by unraveling carbon atoms
from graphene ribbons while an electrical current flowed through the ribbon
and, successively, through the chain. The formation of the chains was
accompanied by a characteristic drop in the electrical conductivity. The
conductivity of carbon chains was much lower than previously predicted for
ideal chains. First-principles calculations using both density functional and
many-body perturbation theory show that strain in the chains determines the
conductivity in a decisive way. Indeed, carbon chains are always under varying
non-zero strain that transforms its atomic structure from cumulene to polyyne
configuration, thus inducing a tunable band gap. The modified electronic
structure and the characteristics of the contact to the graphitic periphery
explain the low conductivity of the locally constrained carbon chain.


title: Gamma Ray Cherenkov-Transition Radiation

abstract:
  The production of gamma-ray Cherenkov-transition radiation (GCTR) by charged
particles in the photon energy region 0.8 - 2 MeV is studied theoretically
using the results of the recent discovery that in the above mentioned region
the dielectric constant or the refraction index of some materials is greater
than 1 due to Delbruck scattering on Coulomb field of nuclei. Using the results
of the carried out numerical calculations, the possibility of observing GCTR
and some of its applications are discussed.


title:
The Herschel PEP/HerMES Luminosity Function. I: Probing the Evolution of
  PACS selected Galaxies to z~4

abstract:
  We exploit the deep and extended far infrared data sets (at 70, 100 and 160
um) of the Herschel GTO PACS Evolutionary Probe (PEP) Survey, in combination
with the HERschel Multi tiered Extragalactic Survey (HerMES) data at 250, 350
and 500 um, to derive the evolution of the restframe 35 um, 60 um, 90 um, and
total infrared (IR) luminosity functions (LFs) up to z~4. We detect very strong
luminosity evolution for the total IR LF combined with a density evolution. In
agreement with previous findings, the IR luminosity density increases steeply
to z~1, then flattens between z~1 and z~3 to decrease at z greater than 3.
Galaxies with different SEDs, masses and sSFRs evolve in very different ways
and this large and deep statistical sample is the first one allowing us to
separately study the different evolutionary behaviours of the individual IR
populations contributing to the IR luminosity density. Galaxies occupying the
well established SFR/stellar mass main sequence (MS) are found to dominate both
the total IR LF and luminosity density at all redshifts, with the contribution
from off MS sources (0.6 dex above MS) being nearly constant (~20% of the total
IR luminosity density) and showing no significant signs of increase with
increasing z over the whole 0.8<z<2.2 range. Sources with mass in the 10<
log(M/Msun) <11 range are found to dominate the total IR LF, with more massive
galaxies prevailing at the bright end of the high-z LF. A two-fold evolutionary
scheme for IR galaxies is envisaged: on the one hand, a starburst-dominated
phase in which the SMBH grows and is obscured by dust, is followed by an AGN
dominated phase, then evolving toward a local elliptical. On the other hand,
moderately starforming galaxies containing a low-luminosity AGN have various
properties suggesting they are good candidates for systems in a transition
phase preceding the formation of steady spiral galaxies.


title: Sperner's Theorem and a Problem of Erdos-Katona-Kleitman

abstract:
  A central result in extremal set theory is the celebrated theorem of Sperner
from 1928, which gives the size of the largest family of subsets of [n] not
containing a 2-chain. Erdos extended this theorem to determine the largest
family without a k-chain. Erdos and Katona, followed by Kleitman, asked how
many chains must appear in families with sizes larger than the corresponding
extremal bounds.
  In 1966, Kleitman resolved this question for 2-chains, showing that the
number of such chains is minimized by taking sets as close to the middle level
as possible. Moreover, he conjectured the extremal families were the same for
k-chains, for all k. In this paper, making the first progress on this problem,
we verify Kleitman's conjecture for the families whose size is at most the size
of the $k+1$ middle levels. We also characterize all extremal configurations.


title: INTEGRAL & RXTE View of Gamma-ray Binaries

abstract:
  Gamma-ray binaries are X-ray binaries with gamma-ray emissions. Their
multi-wavelength emissions range from radio, optical, X-ray and to very high
energy (TeV). X-ray emissions are crucial to understand the nature of gamma-ray
binaries. INTEGRAL and RXTE have covered and monitored most of the gamma-ray
binaries in hard and soft X-rays. Here we report the results of several
gamma-ray binaries and possible gamma-ray binaries from INTEGRAL and RXTE.


title: The geometry of Lie algebroids and its applications to optimal control

abstract:
  The paper presents the geometry of Lie algebroids and its applications to
optimal control. The first part deals with the theory of Lie algebroids,
connections on Lie algebroids and dynamical systems defined on Lie algebroids
(mainly Lagrangian and Hamiltonian systems). In the second part we use the
framework of Lie algebroids in the study of distributional systems (drift less
control affine systems) with holonomic or nonholonomic distributions.


title:
Accuracy of basis-set extrapolation schemes for DFT-RPA correlation
  energies in molecular calculations

abstract:
  We construct a reference benchmark set for atomic and molecular
random-phase-approximation (RPA) correlation energies in a density functional
theory (DFT) framework at the complete basis set limit. This set is used to
evaluate the accuracy of some popular extrapolation schemes for RPA
all-electron molecular calculations. The results indicate that for absolute
energies accurate results, clearly outperforming raw data, are achievable with
two-point extrapolation schemes based on quintuple- and sextuple-zeta basis
sets. Moreover, we show that results in good agreement with the benchmark can
also be also obtained by using a semiempirical extrapolation procedure based on
quadruple- and quintuple-zeta basis sets. Finally, we analyze the performance
of different extrapolation schemes for atomization energies.


title:
Ray system in lasers, nonlinear arithmetic pyramid and nonlinear
  arithmetic triangles

abstract:
  The paper describes a system of rays declining at small angles in lasers. The
correlation between a group of rays and binomial coefficients is shown. The
correlation of distribution of rays in the system of numbers placed in a
three-dimensional table, the nonlinear arithmetic pyramid is shown. Two types
of nonlinear arithmetic triangles are considered. Various types of partitions
of integers is described.


title: Development Of Ontology-Based Intelligent System For Software Testing

abstract:
  Software testing is a prime factor in software industry. Besides knowing the
importance of testing, only limited time is allocated for teaching it. It will
be more efficient if testing is taught simultaneously with programming
foundations. This integrated learning of testing techniques and programming
allows the programmers to perform in a better way and this leads to the
improvement of the performance of the industry progress. In this paper, a
technique named ontology is introduced, it first defines the various testing
process in hierarchy and define relationships among them, to share and reuse
the knowledge that is captured, secondly metadata is created by natural
language processing and finally, the application use ontologies to support test
management, it act as knowledge base for multiple environment with the
integrated teaching of programming foundation and testing concepts. Keywords:
Meta Data, Ontology, Software Testing, Integration, Programming Foundations.


title: Integral Calculus on Quantum Exterior Algebras

abstract:
  Hom-connections and associated integral forms have been introduced and
studied by T.Brzezi\'nski as an adjoint version of the usual notion of a
connection in non-commutative geometry. Given a flat hom-connection on a
differential calculus $(\Omega, d)$ over an algebra $A$ yields the integral
complex which for various algebras has been shown to be isomorphic to the
noncommutative de Rham complex (in the sense of Brzezi\'nski et al.). In this
paper we shed further light on the question when the integral and the de Rham
complex are isomorphic for an algebra $A$ with a flat hom-connection. We
specialise our study to the case where an $n$-dimensional differential calculus
can be constructed on a quantum exterior algebra over an $A$-bimodule. Criteria
are given for free bimodules with diagonal or upper triangular bimodule
structure. Our results are illustrated for a differential calculus on a
multivariate quantum polynomial algebra and for a differential calculus on
Manin's quantum $n$-space.


title: Mixed neutron-star-plus-wormhole systems: Linear stability analysis

abstract:
  We consider configurations consisting of a neutron star with a wormhole at
the core. The wormhole is held open by a ghost scalar field with a quartic
coupling. The neutron matter is described by a perfect fluid with a polytropic
equation of state. We obtain static regular solutions for these systems. A
stability analysis, however, shows that they are unstable with respect to
linear perturbations.


title: Optical Absorption in Twisted Bilayer Graphene

abstract:
  We theoretically study the optical absorption property of twisted bilayer
graphenes with various stacking geometries, and demonstrate that the
spectroscopic characteristics serve as a fingerprint to identify the rotation
angle between two layers. We find that the absorption spectrum almost
continuously evolves in changing the rotation angle, regardless of the lattice
commensurability. The spectrum is characterized by series of peaks associated
with the van Hove singularity, and the peak energies systematically shift with
the rotation angle. We calculate the optical absorption in two different
frameworks; the tight-binding model and the effective continuum model based on
the Dirac equation. For small rotation angles less than $10^\circ$, the
effective model well reproduces the low-energy band structure and the optical
conductivity of the tight-binding model, and also explains the optical
selection rule analytically in terms of the symmetry of the effective
Hamiltonian.


title: Recent progress in staggered chiral perturbation theory

abstract:
  We present a review on recent progress in staggered chiral perturbation
theory (SChPT). In the last decade, the scope of the application of SChPT has
been extended beyond the level of calibration into the region of prediction
with high precision. SChPT becomes an essential tool to do the data analysis
reliably for physical observables calculated using improved staggered fermions.
Here, we focus on the following examples: pion spectrum, pion decay constants,
$\varepsilon_K$, and $\pi-\pi$ scattering amplitudes. In each subject, we
review the recent progress and future prospects.


title: Bending instabilities of soft tissues

abstract:
  Rubber components and soft tissues are often subjected to large bending
deformations "in service". The circumferential line elements on the inner face
of a bent block can contract up to a certain critical stretch ratio lambda_cr
(say) before bifurcation occurs and axial creases appear. For several models
used to describe rubber, it is found that lambda_cr = 0.56, allowing for a 44%
contraction. For models used to describe arteries it is found, somewhat
surprisingly, that the strain-stiffening effect promotes instability. For
example, the models used for the artery of a 70 year old human predict that
lambda_cr = 0.73, allowing only for a 27% contraction. Tensile experiments
conducted on pig skin indicate that bending instabilities should occur even
earlier there.


title:
Identification of Finite Dimensional L\'evy Systems in Financial
  Mathematics

abstract:
  L\'evy processes are widely used in financial mathematics to model return
data. Price processes are then defined as a corresponding geometric L\'evy
process, implying the fact that returns are independent. In this paper we
propose an alternative class of models allowing to describe dependence between
return data. Technically such an alternative model class is obtained by
considering finite dimensional linear stochastic SISO systems driven by a
L\'evy process. In this paper we consider a discrete-time version of this
model, focusing on the problem of identifying the dynamics and the noise
characteristics of such a so-called L\'evy system. The special feature of this
problem is that the characteristic function (c.f.) of the driving noise is
explicitly known, possibly up to a few unknown parameters. We develop and
analyze a variety of novel identification methods by adapting the so-called
empirical characteristic function method (ECF) originally devised for
estimating parameters of c.f.-s from i.i.d. samples. Precise characterization
of the errors of these estimators will be given, and their asymptotic
covariance matrices will be obtained. Their potential to outperform the
prediction error method in estimating the system parameters will also be
demonstrated.


title: Unitary and symmetric units of a commutative group algebra

abstract:
  Let F be the field of two elements and G a finite abelian 2-group with an
involutory automorphism. The extension of this automorphism to the group
algebra FG is called an involutory involution. This determines the groups of
unitary and symmetric normalized units of FG. We calculate the orders and the
invariants of these subgroups.


title: On codimension-one $\mathbb A^1$-fibration with retraction

abstract:
  In this paper we prove some results on the sufficiency of codimension-one
fibre conditions for a flat algebra with a retraction to be locally
$\mathbb{A}^1$ or at least an $\mathbb{A}^1$-fibration.


title: Dynamical Lifshitz-type solutions and aging phenomena

abstract:
  We consider time-dependent Lifshitz-type solutions in type IIB supergravity.
The solutions describe a time evolution from Lifshitz spacetimes to AdS spaces.
We argue the holographic relation of them to aging phenomena in condensed
matter physics. The solutions have no time-translation invariance and possess
the dynamical scaling symmetry with z_c=2. In addition, the time evolution
corresponds to slow (nonexponential) dynamics from nonequilibrium states to the
equilibrium. We also discuss a mechanism of quantum quench to generate
nonequilibrium states.


title:
Study of gas contaminants and interaction with materials in RPC closed
  loop system

abstract:
  Resistive Plate Counters (RPC) detectors at the Large Hadron Collider (LHC)
experiments use gas recirculation systems to cope with large gas mixture
volumes and costs. In this paper a long-term systematic study about gas
purifiers, gas contaminants and detector performance is discussed. The study
aims at measuring the lifetime of purifiers with new and used cartridge
material along with contaminants release in the gas system. During the
data-taking the response of several RPC double-gap detectors was monitored in
order to characterize the correlation between dark currents, filter status and
gas contaminants.


title:
Dobrushin ergodicity coefficient for Markov operators on cones, and
  beyond

abstract:
  The analysis of classical consensus algorithms relies on contraction
properties of adjoints of Markov operators, with respect to Hilbert's
projective metric or to a related family of seminorms (Hopf's oscillation or
Hilbert's seminorm). We generalize these properties to abstract consensus
operators over normal cones, which include the unital completely positive maps
(Kraus operators) arising in quantum information theory. In particular, we show
that the contraction rate of such operators, with respect to the Hopf
oscillation seminorm, is given by an analogue of Dobrushin's ergodicity
coefficient. We derive from this result a characterization of the contraction
rate of a non-linear flow, with respect to Hopf's oscillation seminorm and to
Hilbert's projective metric.


title:
Influence of trap location on the efficiency of trapping in dendrimers
  and regular hyperbranched polymers

abstract:
  In this paper, we study the trapping problem in two representative polymer
networks, Cayley trees and Vicsek fractals, which separately model dendrimers
and regular hyperbranched polymers. Our goal is to explore the impact of trap
location on the efficiency of trapping in these two important polymer systems,
with the efficiency being measured by the average trapping time (ATT) that is
the average of source-to-trap mean first-passage time over every staring point
in the whole networks. For Cayley trees, we derive an exact analytic formula
for the ATT to an arbitrary trap node, based on which we further obtain the
explicit expression of ATT for the case that the trap is uniformly distributed.
For Vicsek fractals, we provide the closed-form solution for ATT to a
peripheral node farthest from the central node, as well as the numerical
solutions for the case when the trap is placed on other nodes. Moreover, we
derive the exact formula for the ATT corresponding to the trapping problem when
the trap has an uniform distribution over all nodes. Our results show that the
influence of trap location on the trapping efficiency is completely different
for the two polymer networks. In Cayley trees, the leading scaling of ATT
increases with the shortest distance between the trap and the central node,
implying that trap's position has an essential impact on the trapping
efficiency; while in Vicsek fractals, the effect of location of the trap is
negligible, since the dominant behavior of ATT is identical, respective of the
location where the trap is placed. We also present that for all cases of
trapping problems being studied, the trapping process is more efficient in
Cayley trees than in Vicsek fractals. We demonstrate that all differences
related to trapping in the two polymer systems are rooted in their underlying
topological structures.


title:
Supersymmetry on Three-dimensional Lorentzian Curved Spaces and Black
  Hole Holography

abstract:
  We study N <= 2 superconformal and supersymmetric theories on Lorentzian
threemanifolds with a view toward holographic applications, in particular to
BPS black hole solutions. As in the Euclidean case, preserved supersymmetry for
asymptotically locally AdS solutions implies the existence of a (charged)
"conformal Killing spinor" on the boundary. We find that such spinors exist
whenever there is a conformal Killing vector which is null or timelike. We
match these results with expectations from supersymmetric four-dimensional
asymptotically AdS black holes. In particular, BPS bulk solutions in global AdS
are known to fall in two classes, depending on their graviphoton magnetic
charge, and we reproduce this dichotomy from the boundary perspective. We
finish by sketching a proposal to find the dual superconformal quantum
mechanics on the horizon of the magnetic black holes.


title: Large zero-field cooled exchange-bias in bulk Mn2PtGa

abstract:
  We report a large exchange-bias (EB) effect after zero-field cooling the new
tetragonal Heusler compound Mn2PtGa from the paramagnetic state. The
first-principle calculation and the magnetic measurements reveal that Mn2PtGa
orders ferrimagnetically with some ferromagnetic (FM) inclusions. We show that
ferrimagnetic (FI) ordering is essential to isothermally induce the exchange
anisotropy needed for the zero-field cooled (ZFC) EB during the virgin
magnetization process. The complex magnetic behavior at low temperatures is
characterized by the coexistence of a field induced irreversible magnetic
behavior and a spin-glass-like phase. The field induced irreversibility
originates from an unusual first-order FI to antiferromagnetic transition,
whereas, the spin-glass like state forms due to the existence of anti-site
disorder intrinsic to the material.


title: Kinematics and chemistry of the hot core in G20.08-0.14N

abstract:
  We present Submillimeter Array observations of the massive star-forming
region G20.08-0.14N at 335 and 345 GHz. With the SMA data, 41 molecular
transitions were detected related to 11 molecular species and their
isotopologues, including SO2, SO, C34S, NS, C17O, SiO, CH3OH, HC3N, H13CO+,
HCOOCH3 and NH2CHO. In G20.08-0.14N, 10 transition lines of the detected 41
transition lines belong to SO2, which dominates the appearance of the
submillimeter-wave spectrum. To obtain the spatial kinematic distribution of
molecules in G20.08-0.14N, we chose the strongest and unblended lines for the
channel maps. The channel maps of C34S an SiO, together with their
position-velocity diagrams, present that there are two accretion flows in
G20.08-0.14N. Additionally, SiO emission shows a collimated outflow at the
NE-SW direction. The direction of the outflow is for the first time revealed.
The rotational temperature and the column density of CH3OH are 105 K and
3.1*10^{17} cm^{-2}, respectively. Our results confirm that a hot core is
associated with G20.08-0.14N. The hot core is heated by a protostar radiation
at it center, not by the external excitation from shocks. The images of the
spatial distribution of different species have shown that the different
molecules are located at the different positions of the hot core. Through
comparing the spatial distributions and abundances of the molecules, we discuss
possible chemical processes for producing the complex sulfur-bearing,
nitrogen-bearing and oxygen-bearing molecules in G20.08-0.14N.


title: Fading entanglement near equilibrium state

abstract:
  It was recently shown that entanglement in quantum systems being in a
non-equilibrium state can appear at much higher temperatures than in an
equilibrium state. However, any system is subject to the natural relaxation
process establishing equilibrium. The work deals with the numerical study of
entanglement dynamics in a dipolar coupled spin-1/2 system under the transition
from a non-equilibrium state to an equilibrium state. The spin system is
characterized by a two-temperature density matrix, and the process of the
establishment of equilibrium is in the equalization of these temperatures. The
method of the non-equilibrium statistical operator is used to describe the
evolution of the system. The process of establishing an equilibrium state in
the homonuclear spin systems at low temperature was first considered. It was
shown that the time dependences of the inverse temperatures of the spin
subsystems are given by a solution of non-linear equations in contrast to the
linear equations in the well-known high temperature approximation. It was first
studied the entanglement dynamics during the equilibrium state establishment
and found that, during establishing equilibrium, the concurrence changes
non-monotonically with time and temperatures. Entanglement fades long before
equilibrium is established in the system. It was shown that the entanglement
dynamics depends strongly on the ratio of the Zeeman energy to the dipolar
energy. At a high ratio, the concurrence in the system decreases quickly for
time about 100 {\mu}s while, at a low ratio, establishment of equilibrium and
fading entanglement take prolonged time up to 1 ms.


title: Quantum entanglement at negative temperature

abstract:
  An isolated spin system that is in internal thermodynamic equilibrium and
that has an upper limit to its allowed energy states can possess a negative
temperature. We calculate the thermodynamic characteristics and the concurrence
in this system over the entire range of positive and negative temperatures. Our
calculation was performed for different real structures, which can be used in
experiments. It is found that the temperature dependence of the concurrence is
substantially asymmetrical similarly other thermodynamic characteristics. At a
negative temperature the maximum concurrence and the absolute temperature of
the entanglement appearance are sufficiently larger than those at a positive
temperature. The concurrence can be characterized by two dimensionless
parameters: by the ratio between the Zeeman and dipolar energies and by the
ratio of the thermal and dipolar energies. It was shown that for all considered
structures the dimensionless temperatures of the transition between
entanglement and separability of the first and second spins are independent of
spin structure and number of spins.


title:
On Quantifying Dependence: A Framework for Developing Interpretable
  Measures

abstract:
  We present a framework for selecting and developing measures of dependence
when the goal is the quantification of a relationship between two variables,
not simply the establishment of its existence. Much of the literature on
dependence measures is focused, at least implicitly, on detection or revolves
around the inclusion/exclusion of particular axioms and discussing which
measures satisfy said axioms. In contrast, we start with only a few
nonrestrictive guidelines focused on existence, range and interpretability,
which provide a very open and flexible framework. For quantification, the most
crucial is the notion of interpretability, whose foundation can be found in the
work of Goodman and Kruskal [Measures of Association for Cross Classifications
(1979) Springer], and whose importance can be seen in the popularity of tools
such as the $R^2$ in linear regression. While Goodman and Kruskal focused on
probabilistic interpretations for their measures, we demonstrate how more
general measures of information can be used to achieve the same goal. To that
end, we present a strategy for building dependence measures that is designed to
allow practitioners to tailor measures to their needs. We demonstrate how many
well-known measures fit in with our framework and conclude the paper by
presenting two real data examples. Our first example explores U.S. income and
education where we demonstrate how this methodology can help guide the
selection and development of a dependence measure. Our second example examines
measures of dependence for functional data, and illustrates them using data on
geomagnetic storms.


title:
Quadrupole transitions in the bound rotational-vibrational spectrum of
  the deuterium molecular ion

abstract:
  After the study of the three body molecular system H$_2^+$ ({\it J. Phys. B:
At. Mol. Opt. Phys.} {\bf 45} 065101), its isotopomer, the deuterium molecular
ion D$_2^+$ is studied. The three-body Schr\"odinger equation is solved using
the Lagrange-mesh method in perimetric coordinates. Energies and wave functions
for four vibrational states $v=0-3$ and bound or quasibound states for total
orbital momenta from 0 to 56 are calculated. The 1986 fundamental constant
$m_d=3670.483014\,m_e$ is used. The obtained energies have an accuracy from
about 13 digits for the lowest vibrational state to at least 9 digits for the
third vibrational excited state. Quadrupole transition probabilities per time
unit between those states over the whole rotational bands were calculated.
Extensive results are presented with six significant figures.


title:
Predicting the Temporal Dynamics of Information Diffusion in Social
  Networks

abstract:
  Online social networks play a major role in the spread of information at very
large scale and it becomes essential to provide means to analyse this
phenomenon. In this paper we address the issue of predicting the temporal
dynamics of the information diffusion process. We develop a graph-based
approach built on the assumption that the macroscopic dynamics of the spreading
process are explained by the topology of the network and the interactions that
occur through it, between pairs of users, on the basis of properties at the
microscopic level. We introduce a generic model, called T-BaSIC, and describe
how to estimate its parameters from users behaviours using machine learning
techniques. Contrary to classical approaches where the parameters are fixed in
advance, T-BaSIC's parameters are functions depending of time, which permit to
better approximate and adapt to the diffusion phenomenon observed in online
social networks. Our proposal has been validated on real Twitter datasets.
Experiments show that our approach is able to capture the particular patterns
of diffusion depending of the studied sub-networks of users and topics. The
results corroborate the "two-step" theory (1955) that states that information
flows from media to a few "opinion leaders" who then transfer it to the mass
population via social networks and show that it applies in the online context.
This work also highlights interesting recommendations for future
investigations.


title: On the toric ideal of a matroid

abstract:
  Describing minimal generating set of a toric ideal is a well-studied and
difficult problem. In 1980 White conjectured that the toric ideal associated to
a matroid is equal to the ideal generated by quadratic binomials corresponding
to symmetric exchanges. We prove White's conjecture up to saturation, that is
that the saturations of both ideals are equal. In the language of algebraic
geometry this means that both ideals define the same projective scheme.
Additionally we prove the full conjecture for strongly base orderable matroids.


title: Beno\^{i}t Mandelbrot and Fractional Brownian Motion

abstract:
  Although fractional Brownian motion was not invented by Benoit Mandelbrot, it
was he who recognized the importance of this random process and gave it the
name by which it is known today. This is a personal account of the history
behind fractional Brownian motion and some subsequent developments.


title: Entanglement in two site Bose-Hubbard model

abstract:
  In this paper, we study the decoherence and entanglement properties for the
two site Bose-Hubbard model in the presence of a non-linear damping. We apply
the techniques of thermo field dynamics and then use Hartree-Fock approximation
to solve the corresponding master equation. The expectation values of the
approximated field operators appearing in the solution of master equation, are
computed self-consistently. We solve this master equation for a small time $t$
so that we get the analytical solution, thereby we compute the decoherence and
entanglement properties of the solution of the two-mode bosonic system.


title: Quantum discord for two-qubit CS states: Analytical solution

abstract:
  We found an universal local unitary (orthogonal) transformation which
transforms any centrosymmetric (CS) density matrix \rho_{CS} into the X density
matrix \rho_X: H\otimes H\rho_{CS}H\otimes H=\rho_X, where H is the Hadamard
transformation. Because quantum discord is invariant under the local unitary
transformations, this remarkable property allows to get the discord of general
two-qubit CS states in the analytical form using the corresponding well-known
formulas for the X states. Examples of systems with CS density matrices
provided from the recent literature, including XXZ spin model with the
Dzyaloshinsky-Moriya interaction, a gas of spin-carrying particles in closed
nanopore, and a family of pseudopure states.


title:
Activation cross-sections of longer lived products of deuteron induced
  nuclear reactions on ytterbium up to 40 MeV

abstract:
  In the frame of a systematic study of the activation cross-sections of the
deuteron induced nuclear reactions, excitation functions of the
natYb(d,xn)177,173,172mg,171mg,170,169Lu, natYb(d,x)175,169Yb and
natYb(d,x)173,172,168,167,165Tm reactions are studied up to 40 MeV, a few of
them for the first time. Cross-sections were measured with the activation
method using a stacked foil irradiation technique and high resolution gamma-ray
spectrometry. The experimental data are analyzed and compared to the results of
the theoretical model codes ALICE-IPPE, EMPIRE-II and TALYS. From the measured
cross-section data integral production yields were calculated. Applications of
the new cross-sections are discussed.


title:
Structure, stability and defects of single layer h-BN in comparison to
  graphene

abstract:
  We study by molecular dynamics the structural properties of single layer h-BN
in comparison to graphene. We show that the Tersoff bond order potential
developed for BN by Albe, Moller and Heinig gives a thermally stable hexagonal
single layer with a bending constant kappa= 0.54 eV at T = 0. We find that the
non-monotonic behaviour of the lattice parameter, the expansion of the
interatomic distance and the growth of the bending rigidity with temperature
are qualitatively similar to those of graphene. Conversely, the energetics of
point defects is extremely different: instead of Stone Wales defects, the two
lowest energy defects in h-BN involve either a broken bond or an out of plane
displacement of a N atom to form a tetrahedron with three B atoms in the plane.
We provide the formation energies and an estimate of the energy barriers.


title:
Topological rf-SQUID with a frustrating pi-junction for probing the
  Majorana Bound State

abstract:
  Majorana Bound States are predicted to appear as boundary states of the
Kitaev model. Here we show that a pi-Josephson Junction, inserted in a
topologically non trivial model ring, sustains a Majorana Bound State, which is
robust with respect to local and non local perturbations. The realistic
structure could be based on a High Tc Superconductor tricrystal structure,
similar to the one used to spot the d-wave order parameter. The presence of the
Majorana Bound State changes the ground state of the topologically non trivial
ring in a measurable way, with respect to that of a conventional one.


title:
Tuning of the Rashba effect in Pb quantum well states via a variable
  Schottky barrier

abstract:
  Spin-orbit interaction (SOI) in low-dimensional systems results in the
fascinating property of spin-momentum locking. In a Rashba system the inversion
symmetry normal to the plane of a two-dimensional (2D) electron gas is broken,
generating a Fermi surface spin texture reminiscent of spin vortices of
different radii. This can be exploited in a spin-based field-effect transistor
(spin- FET), where the Rashba system forms a 2D channel between ferromagnetic
(FM) source and drain electrodes. The electron spin precesses when propagating
through the Rashba channel and spin orientations (anti)parallel to the drain
give (low) high conductivity. Crucial is the possibility to tune the momentum
splitting, and consequently the precession angle, through an external
parameter. Here we show that this can be achieved in Pb quantum well states
through the doping dependence of the Schottky barrier, opening up the
possibility of a terahertz spin-FET.


title:
The Fermat-Torricelli Problem and Weiszfeld's Algorithm in the Light of
  Convex Analysis

abstract:
  In the early 17th century, Pierre de Fermat proposed the following problem:
given three points in the plane, find a point such that the sum of its
Euclidean distances to the three given points is minimal. This problem was
solved by Evangelista Torricelli and was named the {\em Fermat-Torricelli
problem}. A more general version of the Fermat-Torricelli problem asks for a
point that minimizes the sum of the distances to a finite number of given
points in $\Bbb R^n$. This is one of the main problems in location science. In
this paper we revisit the Fermat-Torricelli problem from both theoretical and
numerical viewpoints using some ingredients of convex analysis and
optimization.


title: Positive definite hermitian mappings associated to tripotent elements

abstract:
  We give a simple proof of a meaningful result established by Y. Friedman and
B. Russo in 1985, whose proof was originally based on strong holomorphic
results. We provide a simple proof which is directly deduced from the axioms of
JB*-triples with techniques of Functional Analysis.


title: Chiral symmetry and the Yang--Mills gradient flow

abstract:
  In the last few years, the Yang--Mills gradient flow was shown to be an
attractive tool for non-perturbative studies of non-Abelian gauge theories.
Here a simple extension of the flow to the quark fields in QCD is considered.
As in the case of the pure-gauge gradient flow, the renormalizability of
correlation functions involving local fields at positive flow times can be
established using a representation through a local field theory in 4+1
dimensions. Applications of the extended flow in lattice QCD include
non-perturbative renormalization and O(a) improvement as well as accurate
calculations of the chiral condensate and of the pseudo-scalar decay constant
in the chiral limit.


title: Dynamical Constraints on Multi-Planet Exoplanetary Systems

abstract:
  As a direct result of ongoing efforts to detect more exoplanetary systems, an
ever-increasing number of multiple-planet systems are being announced. But how
many of these systems are truly what they seem? In many cases, such systems are
announced solely on the basis of orbital fits to observational data, and no
attempt is made to see whether the proposed orbits are actually dynamically
feasible. As a result, it is certain that planetary systems are being announced
that involve planets moving on orbits that would be dynamically unstable on
timescales of just a few hundred years.
  Here, we present the results of dynamical simulations that investigate the
orbital stability and evolution of a number of recently discovered exoplanetary
systems. These simulations have enabled us to create highly detailed dynamical
maps of those systems, allowing us to better constrain the orbits of the
planets contained therein. In some cases, our results have even led to the very
existence of the planets themselves being called into question.


title: Elastic Splines I: Existence

abstract:
  Given interpolation points $P_1,P_2,\ldots,P_n$ in the plane, it is known
that there does not exist an interpolating curve with minimal bending energy,
unless the given points lie sequentially along a line. We say than an
interpolating curve is {\it admissable} if each piece, connecting two
consecutive points $P_i$ and $P_{i+1}$, is an s-curve, where an {\it s-curve}
is a planar curve which first turns at most $180^\circ$ in one direction and
then turns at most $180^\circ$ in the opposite direction. Our main result is
that among all admissable interpolating curves there exists a curve with
minimal bending energy. We also prove, in a very constructive manner, the
existence of an s-curve, with minimal bending energy, which connects two given
unit tangent vectors.


title:
MG13 proceedings: On the validity of the adiabatic approximation in
  compact binary inspirals

abstract:
  We use the post-Newtonian-Affine model to assess the validity of the
adiabatic approximation in modeling tidal effects in the phase evolution of
compact binary systems. We compute the dynamical evolution of the tidal tensor,
which we estimate at the 2 PN order, and of the quadrupole tensor, finding that
their ratio, i.e. the tidal deformability, increases in the last phases of the
inspiral. We derive the gravitational wave phase corrections due to this
phenomenon and quantify how they affect gravitational wave detectability.


title:
Radiative parton processes in perturbative QCD - an improved version of
  the Gunion and Bertsch cross section from comparisons to the exact result

abstract:
  In this work we compare the Gunion-Bertsch approximation of the leading order
perturbative QCD radiation matrix element to the exact result. To this end, we
revisit the derivation of the Gunion-Bertsch approximation as well as perform
extensive numerical comparisons of the Gunion-Bertsch and the exact result. We
find that when employing the matrix elements to obtain rates or cross sections
from phase space integration, the amplitude by Gunion and Bertsch deviates from
the correct result in characteristic regions of the phase space. We propose an
improved version of the Gunion-Bertsch matrix element which agrees very well
with the exact result in all phase space regions.


title: Robust estimators for non-decomposable elliptical graphical models

abstract:
  Asymptotic properties of scatter estimators for elliptical graphical models
are studied. Such models impose a given pattern of zeros on the inverse of the
shape matrix of an elliptically distributed random vector. In particular, we
introduce the class of graphical M-estimators and compare them to plug-in
M-estimators. It turns out that, under suitable conditions, both approaches
yield the same asymptotic efficiency. Furthermore, the results of this paper
apply to both decomposable and non-decomposable graphical models and so
generalize the results for decomposable models given by Vogel & Fried (2011)
for the plug-in M-estimators.