title: On Recovering from Run-time Misbehaviour in ADR

abstract:
  We propose a monitoring mechanism for recording the evolution of systems
after certain computations, maintaining the history in a tree-like structure.
Technically, we develop the monitoring mechanism in a variant of ADR (after
Architectural Design Rewriting), a rule-based formal framework for modelling
the evolution of architectures of systems.
  The hierarchical nature of ADR allows us to take full advantage of the
tree-like structure of the monitoring mechanism. We exploit this mechanism to
formally define new rewriting mechanisms for ADR reconfiguration rules. Also,
by monitoring the evolution we propose a way of identifying which part of a
system has been affected when unexpected run-time behaviours emerge. Moreover,
we propose a methodology to suggest reconfigurations that could potentially
lead the system in a non-erroneous state.


title: ABS-NET: Fully Decentralized Runtime Adaptation for Distributed Objects

abstract:
  We present a formalized, fully decentralized runtime semantics for a core
subset of ABS, a language and framework for modelling distributed
object-oriented systems. The semantics incorporates an abstract graph
representation of a network infrastructure, with network endpoints represented
as graph nodes, and links as arcs with buffers, corresponding to OSI layer 2
interconnects. The key problem we wish to address is how to allocate
computational tasks to nodes so that certain performance objectives are met. To
this end, we use the semantics as a foundation for performing network-adaptive
task execution via object migration between nodes. Adaptability is analyzed in
terms of three Quality of Service objectives: node load, arc load and message
latency. We have implemented the key parts of our semantics in a simulator and
evaluated how well objectives are achieved for some application-relevant
choices of network topology, migration procedure and ABS program. The
evaluation suggests that it is feasible in a decentralized setting to
continually meet both the objective of a node-balanced task allocation and make
headway towards minimizing communication, and thus arc load and message
latency.


title:
Standard finite elements for the numerical resolution of the elliptic
  Monge-Ampere equation: classical solutions

abstract:
  We propose a new variational formulation of the elliptic Monge-Ampere
equation and show how classical Lagrange elements can be used for the numerical
resolution of classical solutions of the equation. Error estimates are given
for Lagrange elements of degree d >= 2 in dimensions 2 and 3. No jump term is
used in the variational formulation. We propose to solve the discrete nonlinear
system of equations by a time marching method and numerical evidence is given
which indicates that one approximates weak solutions in two dimensions.


title: A highly optimized flow-correlation attack

abstract:
  Deciding that two network flows are essentially the same is an important
problem in intrusion detection and in tracing anonymous connections. A stepping
stone or an anonymity network may try to prevent flow correlation by adding
chaff traffic, splitting the flow in several subflows or adding random delays.
A well-known attack for these types of systems is active watermarking. However,
active watermarking systems can be detected and an attacker can modify the flow
in such a way that the watermark is removed and can no longer be decoded. This
leads to the two basic features of our scheme: a highlyoptimized algorithm that
achieves very good performance and a passive analysis that is undetectable. We
propose a new passive analysis technique where detection is based on
Neyman-Pearson lemma. We correlate the inter-packet delays (IPDs) from both
flows. Then, we derive a modification to deal with stronger adversary models
that add chaff traffic, split the flows or add random delays. We empirically
validate the detectors with a simulator. Afterwards, we create a watermarkbased
version of our scheme to study the trade-off between performance and
detectability. Then, we compare the results with other state-of-the-art traffic
watermarking schemes in several scenarios concluding that our scheme
outperforms the rest. Finally, we present results using an implementation of
our method on live networks, showing that the conclusions can be extended to
real-world scenarios. Our scheme needs only tens of packets under normal
network interference and a few hundreds of packets when a number of
countermeasures are taken.


title:
Systematic and correlated nuclear uncertainties in the i-process at the
  neutron shell closure N = 82

abstract:
  Nuclear astrophysics simulations aiming to study the origin of the elements
in stars require a multitude of nuclear physics input. Both systematic model
dependent and statistically correlated uncertainties need to be considered. An
application where realistic uncertainty assessments are especially important is
the intermediate neutron capture process or i process: a neutron capture regime
with neutron densities intermediate between the slow and rapid processes.
Accordingly, the main network flux proceeds on the neutron-rich unstable
isotopes up to 4-5 species off the valley of stability. The i process has been
clearly identified to be active in post-AGB stars during the Very Late Thermal
Pulse H-ingestion event, and a recent work infers about its important role in
early generations of stars. Here we demonstrate the effect of propagating
systematic nuclear uncertainties from different theoretical models to final
abundances for a region around the 2$^\mathrm{nd}$ peak at $A-Z=80$ for
elemental ratio predictions involving Ba, La and Eu in i-process conditions.
These elements are used to distinguish different n-capture contributions
observed in low-metallicity stars. For the simple 1-zone model adopted here,
predictions vary as much as a factor of 22 in on possible observational plane
([La/Eu] vs. [Ba/La]). To consider statistically correlated uncertainties, we
similarly perform a full nuclear physics uncertainty study within a given
Hauser-Feshbach model and demonstrate the role of correlations on the final
stellar abundance uncertainties. We show that in i-process conditions the main
result of neglecting correlations is to underestimate the impact of nuclear
uncertainties on the final nucleosynthesis yields by as much as two orders of
magnitude. (continued in document)


title:
Discriminative Link Prediction using Local Links, Node Features and
  Community Structure

abstract:
  A link prediction (LP) algorithm is given a graph, and has to rank, for each
node, other nodes that are candidates for new linkage. LP is strongly motivated
by social search and recommendation applications. LP techniques often focus on
global properties (graph conductance, hitting or commute times, Katz score) or
local properties (Adamic-Adar and many variations, or node feature vectors),
but rarely combine these signals. Furthermore, neither of these extremes
exploit link densities at the intermediate level of communities. In this paper
we describe a discriminative LP algorithm that exploits two new signals. First,
a co-clustering algorithm provides community level link density estimates,
which are used to qualify observed links with a surprise value. Second, links
in the immediate neighborhood of the link to be predicted are not interpreted
at face value, but through a local model of node feature similarities. These
signals are combined into a discriminative link predictor. We evaluate the new
predictor using five diverse data sets that are standard in the literature. We
report on significant accuracy boosts compared to standard LP methods
(including Adamic-Adar and random walk). Apart from the new predictor, another
contribution is a rigorous protocol for benchmarking and reporting LP
algorithms, which reveals the regions of strengths and weaknesses of all the
predictors studied here, and establishes the new proposal as the most robust.


title:
Invariant Energy Levels and Flat Band Engineering in a Kondo Lattice
  Model on Geometrically Frustrated Lattices

abstract:
  We show the existence of invariant energy levels in a Kondo lattice model on
an isolated complete graph, such as a triangle and a tetrahedron. These energy
levels always have fixed eigenenergies $t \pm J/2$, irrespective of the
configuration of localized moments ($t$ is the transfer integral of conduction
electrons and $J$ is the spin-charge coupling constant). We also extend the
analysis to geometrically frustrated lattices by using the complete graphs as
basic building blocks. We show that the construction rule for the invariant
energy levels leads to the existence condition of localized states, if the
model is defined on the triangle-based line graphs, such as a kagome lattice.
We further propose a procedure of engineering isolated flat bands with broken
time-reversal symmetry, which are separated from other dispersive bands with
finite energy gaps.


title:
Quantum Side Information: Uncertainty Relations, Extractors, Channel
  Simulations

abstract:
  In the first part of this thesis, we discuss the algebraic approach to
classical and quantum physics and develop information theoretic concepts within
this setup.
  In the second part, we discuss the uncertainty principle in quantum
mechanics. The principle states that even if we have full classical information
about the state of a quantum system, it is impossible to deterministically
predict the outcomes of all possible measurements. In comparison, the
perspective of a quantum observer allows to have quantum information about the
state of a quantum system. This then leads to an interplay between uncertainty
and quantum correlations. We provide an information theoretic analysis by
discussing entropic uncertainty relations with quantum side information.
  In the third part, we discuss the concept of randomness extractors. Classical
and quantum randomness are an essential resource in information theory,
cryptography, and computation. However, most sources of randomness exhibit only
weak forms of unpredictability, and the goal of randomness extraction is to
convert such weak randomness into (almost) perfect randomness. We discuss
various constructions for classical and quantum randomness extractors, and we
examine especially the performance of these constructions relative to an
observer with quantum side information.
  In the fourth part, we discuss channel simulations. Shannon's noisy channel
theorem can be understood as the use of a noisy channel to simulate a noiseless
one. Channel simulations as we want to consider them here are about the reverse
problem: simulating noisy channels from noiseless ones. Starting from the
purely classical case (the classical reverse Shannon theorem), we develop
various kinds of quantum channel simulation results. We achieve this by using
classical and quantum randomness extractors that also work with respect to
quantum side information.


title:
Magnetic response of Pr$_{1-x}$LaCe$_x$CuO$_4$ in comparison with
  hole-doped cuprates

abstract:
  The origin of differences in the magnetic responses of
Pr$_{1-x}$LaCe$_x$CuO$_4$ with $x=0.11-0.12$ and moderately doped $p$-type
cuprates is investigated using the t-J model, the Mori projection operator
technique and dispersions of charge carriers derived from photoemission
experiments. These differences are related to the proximity of the former
crystal to the boundary of the antiferromagnetic phase and to the remoteness of
$p$-type compounds from it. This leads to different nesting vectors of the
low-frequency equi-energy contours of carrier dispersions in these crystals.
The strong nesting with the antiferromagnetic momentum as the nesting vector
produces the commensurate low-frequency response and the coexistence of two
spin-excitation branches in Pr$_{1-x}$LaCe$_x$CuO$_4$, while incommensurate
nesting vectors in $p$-type crystals lead to the incommensurate low-frequency
response and the hourglass dispersion of susceptibility maxima.


title:
Low complexity resource allocation for load minimization in OFDMA
  wireless networks

abstract:
  To cope with the ever increasing demand for bandwidth, future wireless
networks will be designed with reuse distance equal to one. This scenario
requires the implementation of techniques able to manage the strong multiple
access interference each cell generates towards its neighbor cells. In
particular, low complexity and reduced feedback are important requirements for
practical algorithms. In this paper we study an allocation problem for OFDMA
networks formulated with the objective of minimizing the load of each cell in
the system subject to the constraint that each user meets its target rate. We
decompose resource allocation into two sub-problems: channel allocation under
deterministic power assignment and continuous power assignment optimization.
Channel allocation is formulated as the problem of finding the maximum weighted
independent set (MWIS) in graph theory. In addition, we propose a minimal
weighted-degree greedy (MWDG) algorithm of which the approximation factor is
analyzed. For power allocation, an iterative power reassignment algorithm
(DPRA) is proposed. The control information requested to perform the allocation
is limited and the computational burden is shared between the base station and
the user equipments. Simulations have been carried out under constant bit rate
traffic model and the results have been compared with other allocation schemes
of similar complexity. MWDG has excellent performance and outperforms all other
techniques.


title:
Global non-spherical oscillations in 3-D $4\pi$ simulations of the
  H-ingestion flash

abstract:
  We performed 3-D simulations of proton-rich material entrainment into
\czw-rich He-shell flash convection and the subsequent H-ingestion flash that
took place in the post-AGB star Sakurai's object. Observations of the transient
nature and anomalous abundance features are available to validate our method
and assumptions, with the aim to apply them to very low metallicity stars in
the future. We include nuclear energy feedback from H burning and cover the
full $4\pi$ geometry of the shell. Runs on $768^3$ and $1536^3$ grids agree
well with each other and have been followed for $1500\mathrm{min}$ and
$1200\mathrm{min}$. After a $850\mathrm{min}$ long quiescent entrainment phase
the simulations enter into a global non-spherical oscillation that is launched
and sustained by individual ignition events of H-rich fluid pockets. Fast
circumferential flows collide at the antipode and cause the formation and
localized ignition of the next H-overabundant pocket. The cycle repeats for
more than a dozen times while its amplitude decreases. During the global
oscillation the entrainment rate increases temporarily by a factor $\approx
100$. Entrained entropy quenches convective motions in the upper layer until
the burning of entrained H establishes a separate convection zone. The
lower-resolution run hints at the possibility that another global oscillation,
perhaps even more violent will follow. The location of the H-burning convection
zone agrees with a 1-D model in which the mixing efficiency is calibrated to
reproduce the light curve. The simulations have been performed at the NSF Blue
Waters supercomputer at NCSA.


title: Resonance Mass Spectra of Gravity and Fermion on Bloch Branes

abstract:
  In this paper, by presenting the potentials of Kaluza-Klein (KK) modes in the
corresponding Schr\"{o}dinger equations, we investigate the localization and
resonances of gravity and fermion on the symmetric and asymmetric Bloch
{branes}. We find that the localization properties of zero modes for gravity
and fermion in the symmetric brane case are the same, whereas, for the
asymmetric brane case, the fermion zero mode is localized on one of the
sub-branes, while the gravity zero mode is localized on another sub-brane. The
spectra of the gravity and the left- or right-handed fermion are composed of a
bound zero mode and a series of gapless continuous massive KK modes. Among the
continuous massive KK modes, we obtain some discrete gravity and fermion
resonant (quasilocalized) KK states on the brane, which have a finite
probability of escaping into the bulk. The KK states with lower resonant masses
have a longer lifetime on the brane. And the number of the resonant KK states
increases linearly with the width of the brane and the scalar-fermion coupling
constant, {but it decreases with the asymmetric factor $\beta$}. The structure
of the resonance spectrum is investigated in detail.


title: One-way transparent sheets

abstract:
  In this paper we introduce the concept of metasurfaces which are fully
transparent when looking from one of the two sides of the sheet and have
controllable functionalities for waves hitting the opposite side (one-way
transparent sheets). We address the question on what functionalities are
allowed, considering limitations due to reciprocity and passivity. In
particular, we have found that it is possible to realize one-way transparent
sheets which have the properties of a twist-polarizer in reflection or
transmission when illuminated from the other side. Also one-way transparent
sheets with controllable co-polarized reflection and transmission from the
opposite side are feasible. We show that particular non-reciprocal
magneto-electric coupling inside the sheet is necessary to realize lossless
non-active transparent sheets. Furthermore, we derive the required
polarizabilities of constituent dipole particles such that the layers composed
of them form one-way transparent sheets. We conclude with design and
simulations of an example of a nonreciprocal one-way transparent sheet
functioning as an isolating twist-polarizer.


title: The Two-Point Connection Problem for a Sub-Class of the Heun Equation

abstract:
  The present article discusses the two point connection problem for Heun's
differential equation. We employ a contour integral method to derive connection
matrices for a sub-class of the Heun equation containing 3 free parameters.
Explicit expressions for the connection coefficients are found.


title: Arbitrary Sequence RAMs

abstract:
  It is known that in some cases a Random Access Machine (RAM) benefits from
having an additional input that is an arbitrary number, satisfying only the
criterion of being sufficiently large. This is known as the ARAM model. We
introduce a new type of RAM, which we refer to as the Arbitrary Sequence RAM
(ASRAM), that generalises the ARAM by allowing the generation of additional
arbitrary large numbers at will during execution time. We characterise the
power contribution of this ability under several RAM variants.
  In particular, we demonstrate that an arithmetic ASRAM is more powerful than
an arithmetic ARAM, that a sufficiently equipped ASRAM can recognise any
language in the arithmetic hierarchy in constant time (and more, if it is given
more time), and that, on the other hand, in some cases the ASRAM is no more
powerful than its underlying RAM.


title:
HELGA: The Herschel Exploitation of the Local Galaxy Andromeda. Sub-mm
  morphology and dust properties

abstract:
  The results from a large field Far-Infrared (FIR) and sub-millimeter (sub-mm)
survey of our neighbor galaxy M31 are presented. We have obtained Herschel
images of a ~5.5x2.5 degree area centered on Andromeda. Using 21 cm atomic
hydrogen maps, we are able to disentangle genuine emission from M31 from that
for foreground Galactic cirrus, allowing us to recognize dusty structures out
to ~31 kpc from the center. We first characterize the FIR and sub-mm morphology
and then, by de-projecting Herschel maps and running an ad--hoc source
extraction algorithm, we reconstruct the intrinsic morphology and the spatial
distribution of the molecular complexes. Finally, we study the spatially
resolved properties of the dust (temperature, emissivity, mass, etc.), by means
of a pixel-by-pixel SED fitting approach.


title:
A sufficient condition for the subexponential asymptotics of GI/G/1-type
  Markov chains with queueing applications

abstract:
  The main contribution of this paper is to present a new sufficient condition
for the subexponential asymptotics of the stationary distribution of a
GI/GI/1-type Markov chain without jumps from level "infinity" to level zero.
For simplicity, we call such Markov chains {\it GI/GI/1-type Markov chains
without disasters} because they are often used to analyze semi-Markovian queues
without "disasters", which are negative customers who remove all the customers
in the system (including themselves) on their arrivals. In this paper, we
demonstrate the application of our main result to the stationary queue length
distribution in the standard BMAP/GI/1 queue. Thus we obtain new asymptotic
formulas and prove the existing formulas under weaker conditions than those in
the literature. In addition, applying our main result to a single-server queue
with Markovian arrivals and the $(a,b)$-bulk-service rule (i.e., MAP/${\rm
GI}^{(a,b)}$/1 queue), we obatin a subexponential asymptotic formula for the
stationary queue length distribution.


title:
Improved Interfacial and Electrical Properties of GaSb Metal Oxide
  Semiconductor Devices Passivated with Acidic (NH4)2S Solution

abstract:
  Surface passivation with acidic (NH4)2S solution is shown to be effective in
improving the interfacial and electrical properties of HfO2/GaSb metal oxide
semiconductor devices. Compared with control samples, those treated with acidic
(NH4)2S solution showed great improvements in frequency dispersion, gate
leakage current and interface trap density. These improvements were attributed
to the acidic (NH4)2S solution enhancing passivation of the substrates, which
was analyzed from the perspective of chemical mechanism and confirmed by X-ray
photoelectron spectroscopy and high-resolution cross-sectional transmission
electron microscopy.


title:
Superconductivity and magnetic order in the non-centrosymmetric Half
  Heusler compound ErPdBi

abstract:
  We report superconductivity at $T_c = 1.22$ K and magnetic order at $T_N =
1.06$ K in the semi-metallic noncentrosymmetric Half Heusler compound ErPdBi.
The upper critical field, $B_{c2}$, has an unusual quasi-linear temperature
variation and reaches a value of 1.6 T for $T \rightarrow 0$. Magnetic order is
found below $T_c$ and is suppressed at $B{_M} \sim 2.5$ T for $T \rightarrow
0$. Since $T_c \simeq T_N$, the interaction of superconductivity and magnetism
is expected to give rise to a complex ground state. Moreover, electronic
structure calculations show ErPdBi has a topologically nontrivial band
inversion and thus may serve as a new platform to study the interplay of
topological states, superconductivity and magnetic order.


title:
S-duality Improved Perturbation Theory in Compactified Type I /
  Heterotic String Theory

abstract:
  We study the mass of the stable non-BPS state in type I / heterotic string
theory compactified on a circle with the help of the interpolation formula
between weak and strong coupling results. Comparison between the results at
different orders indicate that this procedure can determine the mass of the
particle to within 10% accuracy over the entire two dimensional moduli space
parametrized by the string coupling and the radius of compactification. This
allows us to estimate the region of the stability of the particle in this two
dimensional moduli space. Outside this region the particle is unstable against
decay into three BPS states carrying the same total charge as the original
state. We discuss generalization of this analysis to compactification on higher
dimensional tori.


title: Beck's Conjecture For Multiplicative Lattices

abstract:
  In this paper, we introduce the zero divisor graph of a multiplicative
lattice. We provide a counter example to Beck's conjecture for multiplicative
lattices. Further, we prove that Beck's conjecture is true for reduced
multiplicative lattice which extends the result of Behboodi and Rakeei[7], and
Aalipour et. al.[1].


title:
Proceedings Ninth International Workshop on Foundations of Mobile
  Computing

abstract:
  Mobile communication has become a vigorous field of research in computer
science, due to the wide spreading of mobile technologies, applications and
services. The intertwining of communication, computation and mobility
constantly poses new challenges to algorithmic design in this area. The
Foundations of Mobile Computing (FOMC) workshop is dedicated to all aspects
that cover contributions both in the design and analysis of
discrete/distributed algorithms, and in the system modeling of mobile, wireless
and similarly dynamic networks. It aims to bring together the practitioners and
theoreticians of the field to foster cooperation between research in mobile
computing and algorithms.


title: Energy-Efficient Cooperative Protocols for Full-Duplex Relay Channels

abstract:
  In this work, energy-efficient cooperative protocols are studied for
full-duplex relaying (FDR) with loopback interference. In these protocols,
relay assistance is only sought under certain conditions on the different link
outages to ensure effective cooperation. Recently, an energy-efficient
selective decode-and-forward protocol was proposed for FDR, and was shown to
outperform existing schemes in terms of outage. Here, we propose an incremental
selective decode-and-forward protocol that offers additional power savings,
while keeping the same outage performance. We compare the performance of the
two protocols in terms of the end-to-end signal-to-noise ratio cumulative
distribution function via closed-form expressions. Finally, we corroborate our
theoretical results with simulation, and show the relative relay power savings
in comparison to non-selective cooperation in which the relay cooperates
regardless of channel conditions.


title: Pseudogap and singlet formation in cuprate and organic superconductors

abstract:
  The pseudogap phase occurring in cuprate and organic superconductors is
analyzed based on the dynamical cluster approximation (DCA) approach to the
Hubbard model. A cluster embedded in a self-consistent bath is studied. With
increasing Coulomb repulsion, U, the antinodal point [k=(pi,0)] displays a
gradual suppression of spectral density of states around the Fermi energy which
is not observed at the nodal point [k=(pi/2,pi/2)]. The opening of the
antinodal pseudogap is related to the internal structure of the cluster and the
much weaker bath-cluster couplings at the antinodal than nodal point. The role
played by internal cluster correlations is elucidated from a simple four-level
model. For small U, the cluster levels form Kondo singlets with their baths
leading to a peak in the spectral density. As U is increased a localized state
is formed localizing the electrons in the cluster. If this cluster localized
state is non-degenerate, the Kondo effect is destroyed and a pseudogap opens up
in the spectra at the anti-nodal point. The pseudogap can be understood in
terms of destructive interference between different paths for electrons hopping
between the cluster and the bath. However, electrons at the nodal points remain
in Kondo states up to larger U since they are more strongly coupled to the
bath. The strong correlation between the (pi,0) and (0,pi) cluster levels in
the localized state leads to a large correlation energy gain which is important
for localizing electrons and opening up a pseudogap. Such scenario is in
contrast with two independent Mott transitions found in two-band systems with
different bandwidths in which the localized cluster electron does not correlate
strongly with any other cluster electron for intermediate U. The important
intracluster sector correlations are associated with the resonating valence
bond (RVB) character of the cluster.


title: DNA flexibility on short length scales probed by atomic force microscopy

abstract:
  Unusually high bending flexibility has been recently reported for DNA on
short length scales. We use atomic force microscopy (AFM) in solution to obtain
a direct estimate of DNA bending statistics for scales down to one helical
turn. It appears that DNA behaves as a Gaussian chain and is well described by
the worm-like chain model at length scales beyond 3 helical turns (10.5nm).
Below this threshold, the AFM data exhibit growing noise because of
experimental limitations. This noise may hide small deviations from the
Gaussian behavior, but they can hardly be significant.


title:
Tunneling induced transparency and controllable group velocity in triple
  and multiple quantum-dot molecules

abstract:
  We analyze the interaction of a triple quantum dot molecules controlled by
the tunneling coupling instead of coupling laser. A general analytic expression
for the steady-state linear susceptibility for a probe-laser field is obtained
and we show that the system can exhibit two transparency windows. The group
velocity of the probe-laser pulse is also analyzed. By changing the tunneling
couplings, two laser pulses with different central frequency can propagate with
the same group velocity. And the group velocity can be as low as 300 m/s in our
system. We extend our analysis to the case of multiple quantum dot molecules
(the number of the quantum dots is N) and show that the system can exhibit at
most N-1 transparency windows. And at most N-1 laser pulses with different
central frequencies can be slowed down.


title:
H\"older continuity and bounds for fundamental solutions to
  non-divergence form parabolic equations

abstract:
  We consider the non-degenerate second-order parabolic partial differential
equations of non-divergence form with bounded measurable coefficients (not
necessary continuous). Under some assumptions it is known that the fundamental
solution to the equations exists uniquely, has the Gaussian bounds and is
locally H\"older continuous. In the present paper, we concern the Gaussian
bounds and the lower bound of the index of the H\"older continuity with respect
to the initial point. We use the pinned diffusion processes for the
probabilistic representation of the fundamental solutions and apply the
coupling method to obtain the regularity of them. Under some assumptions weaker
than the H\"older continuity of the coefficients, we obtain the Gaussian bounds
and the $(1-\varepsilon)$-H\"older continuity of the fundamental solution in
the initial point.


title:
Coexistence of orbital degeneracy lifting and superconductivity in
  iron-based superconductors

abstract:
  In contrast to conventional superconducting (SC) materials, superconductivity
in high-temperature superconductors (HTCs) usually emerges in the presence of
other fluctuating orders with similar or higher energy scales, thus instigating
debates over their relevance for the SC pairing mechanism. In iron-based
superconductors (IBSCs), local orbital fluctuations have been proposed to be
directly responsible for the structural phase transition and closely related to
the observed giant magnetic anisotropy and electronic nematicity. However,
whether superconductivity can emerge from, or even coexist with orbital
fluctuations, remains unclear. Here we report the angle-resolved photoemission
spectroscopy (ARPES) observation of the lifting of symmetry-protected band
degeneracy, and consequently the breakdown of local tetragonal symmetry in the
SC state of Li(Fe1-xCox)As. Supported by theoretical simulations, we analyse
the doping and temperature dependences of this band-splitting and demonstrate
an intimate connection between ferro-orbital correlations and
superconductivity.


title:
Computable estimates of the distance to the exact solution of the
  evolutionary reaction-diffusion equation

abstract:
  We derive guaranteed bounds of distance to the exact solution of the
evolutionary reaction-diffusion problem with mixed Dirichlet-Neumann boundary
condition. It is shown that two-sided error estimates are directly computable
and equivalent to the error. Numerical experiments confirm that estimates
provide accurate two-sided bounds of the overall error and generate efficient
indicators of local error distribution.


title:
Radio-detection of extensive air showers at the Pierre Auger Observatory
  - Results and enhancements

abstract:
  The Pierre Auger Collaboration is exploring the potential of radio-detection
techniques to measure the extensive air showers. The main advantage of these
setups is the possibility to cover a large area with no atmospheric attenuation
and having 100% duty cycle. Radio emission in the MHz range is recorded by the
Auger Engineering Radio Array (AERA), presently consisting of 124 stations
distributed over an area of approximately 6 km$^2$. This enhancement is focused
on physics of cosmic rays with an energy greater than 10$^{17}$ eV. In
addition, novel detection techniques based on the GHz emission from extensive
air showers are being tested at the Pierre Auger Observatory. Three different
setups are currently installed and are collecting data: MIDAS (Microwave
Detection of Air Showers) and AMBER (Air-shower Microwave Bremsstrahlung
Experimental Radiometer) are prototypes of an imaging parabolic dish detector,
while EASIER (Extensive Air Shower Identification using Electron Radiometer)
records the radio emission by antenna horns located on more than 60 surface
detector units. The status of these different activities and the new results in
MHz and GHz bands will be reported.


title:
Effects of spontaneously generated coherence on resonance fluorescence
  from lateral triple quantum -dot molecules

abstract:
  We investigate the spectrum of the resonance fluorescence from the lateral
triple quantum dots controlled by voltage and obtain some interesting features
such as controllable triple narrow peaks. In our system we use tunneling
instead of coupling lasers, and the positions, widths and heights of the
resonance fluorescence peaks can be controlled by tuning the tunneling
couplings. We explain the observed spectrum with the transition properties of
the dressed states generated by the coupling of the two tunneling and the laser
field. These features can also be viewed as the effects of Spontaneously
Generated Coherence between the close-lying levels in the dressed state picture
of the tunneling couplings. And the scheme proposed here can permit the
observation of Spontaneously Generated Coherence.


title: Triviality of the higher Formality Theorem

abstract:
  It is noted that the higher version of M. Kontsevich's Formality Theorem is
much easier than the original one. Namely, we prove that the higher
Hochschild-Kostant-Rosenberg map is already a homotopy e_{n+1}-formality
quasi-isomorphism whenever n is at least 2.


title: Local law for eigenvalues of random regular bipartite graphs

abstract:
  In this paper we study the local law for eigenvalues of large random regular
bipartite graphs with degree growing arbitrarily fast. We prove that the
empirical spectral distribution of the adjacency matrix converges to a scaled
down copy of the Marchenko - Pastur distribution on intervals of short length.


title: The continued fractions ladder of specific pairs of irrationals

abstract:
  Quadratic irrationals posses a periodic continued fraction expansion. Much
less is known about cubic irrationals. We do not even know if the partial
quotients are bounded, even though extensive computations suggest they might
follow Kuzmin's probability law. Results are given for sequences of partial
quotients of positive irrational numbers $\xi$ and $m \over \xi$ with $m$ a
natural number. A big partial quotient in one sequence finds a connection in
the other.


title:
Subexponential tail equivalence of the queue length distributions of
  BMAP/GI/1 queues with and without retrials

abstract:
  The main contribution of this paper is to prove the subexponential tail
equivalence of the stationary queue length distributions in the BMAP/GI/1
queues with and without retrials. We first present a
stochastic-decomposition-like result of the stationary queue length in the
BMAP/GI/1 retrial queue, which is an extension of the stochastic decomposition
of the stationary queue length in the M${}^X$/GI/1 retrial queue. The
stochastic-decomposition-like result shows that the stationary queue length
distribution in the BMAP/GI/1 retrial queue is decomposed into two parts: the
stationary conditional queue length distribution given that the server is idle;
and a certain matrix sequence associated with the stationary queue length
distribution in the corresponding standard BMAP/GI/1 queue (without retrials).
Using the stochastic-decomposition-like result and matrix analytic methods, we
prove the subexponential tail equivalence of the stationary queue length
distributions in the BMAP/GI/1 queues with and without retrials. This tail
equivalence result does not necessarily require that the size of an arriving
batch is light-tailed, unlike Yamamuro's result for the M${}^X$/GI/1 retrial
queue (Queueing Syst. 70:187--205, 2012). As a by-product, the key lemma to the
roof of the main theorem presents a subexponential asymptotic formula for the
stationary distribution of a level-dependent M/G/1-type Markov chain, which is
the first reported result on the subexponential asymptotics of level-dependent
block-structured Markov chains.


title: A high-speed optical link to entangle quantum dots

abstract:
  A long-distance quantum network for distributing entangled states would
support novel information applications, such as unconditionally secure
cryptography and distributed quantum computing. Realizing such a network
requires hardware that can reliably and efficiently establish entanglement over
long distances, despite challenges like loss and transmission delay. We propose
a new scheme for distributing entanglement that increases communication rates
one to two orders of magnitude over existing protocols. The method is less
sensitive to overall system loss because it transmits many signals within one
round-trip-time window and efficiently discriminates lost-photon events. While
the scheme applies to many types of matter qubits, we analyze a specific
implementation with optical quantum dots, showing that the method uses
practical hardware consistent with recent experiments.


title:
Versatile shaper-assisted discretization of energy-time entangled
  photons

abstract:
  We demonstrate the capability to discretize the frequency spectrum of
broadband energy-time entangled photons by means of a spatial light modulator
to encode qudits in various bases. Exemplarily, we implement three different
discretization schemes, namely frequency bins, time bins and Schmidt modes.
Entangled qudits up to dimension $d=4$ are then revealed by two-photon
interference experiments with visibilities violating a $d$-dimensional Bell
inequality.


title:
Local law for eigenvalues of random Hermitian matrices with external
  source

abstract:
  We prove a local law for eigenvalues of the random Hermitian matrices with
external source $W_n=\frac{1}{n}X_n+A_n$ where $X_n$ is Wigner matrix and $A_n$
is diagonal matrix with only two values $a, -a$ on the diagonal. The local law
is an essential step to prove the universality conjecture for this random
matrix model.


title: Phase transitions in the two-dimensional electron-hole gas

abstract:
  A first order phase transition between a BCS phase and an insulating Mott
phase for a gas of spatially separated electrons and holes with tunable Coulomb
interaction and variable density is predicted. In the framework of a BCS-like
mean-field approach and a Landau expansion in terms of the pairing order
parameter the phase diagram is studied. This indicates several phases and phase
transitions, including an electron-hole plasma at low density and weak
interaction, an intermediate BCS phase with Cooper pairs and an electron-hole
plasma at high density and weak interaction. The insulating Mott phase appears
for the strong interaction and low temperatures. We briefly discuss the
possibilities to realize these phases in realistic systems such as coupled
quantum wells and graphene double layers.


title: Bounding Helly numbers via Betti numbers

abstract:
  We show that very weak topological assumptions are enough to ensure the
existence of a Helly-type theorem. More precisely, we show that for any
non-negative integers $b$ and $d$ there exists an integer $h(b,d)$ such that
the following holds. If $\mathcal F$ is a finite family of subsets of $\mathbb
R^d$ such that $\tilde\beta_i\left(\bigcap\mathcal G\right) \le b$ for any
$\mathcal G \subsetneq \mathcal F$ and every $0 \le i \le \lceil d/2 \rceil-1$
then $\mathcal F$ has Helly number at most $h(b,d)$. Here $\tilde\beta_i$
denotes the reduced $\mathbb Z_2$-Betti numbers (with singular homology). These
topological conditions are sharp: not controlling any of these $\lceil d/2
\rceil$ first Betti numbers allow for families with unbounded Helly number.
  Our proofs combine homological non-embeddability results with a Ramsey-based
approach to build, given an arbitrary simplicial complex $K$, some well-behaved
chain map $C_*(K) \to C_*(\mathbb R^d)$.


title: Quark flavour observables in 331 models in the flavour precision era

abstract:
  I discuss a new Physics scenario, the 331 model, based on the gauge group
$SU(3)_c \times SU(3)_L \times U(1)_X$. In particular, I elaborate on
correlations between flavour observables in the $B_d$ and $B_s$ systems that
can help constraining the model parameters.


title: I-ball formation with logarithmic potential

abstract:
  A coherently oscillating real scalar field with potential shallower than
quadratic one fragments into spherical objects called I-balls. We study the
I-ball formation for logarithmic potential which appears in many cosmological
models. We perform lattice simulations and find that the I-balls are formed
when the potential becomes dominated by the quadratic term. Furthermore, we
estimate the I-ball profile assuming that the adiabatic invariant is conserved
during formation and obtain the result that agrees to the numerical
simulations.


title: Partial data inverse problems for the Hodge Laplacian

abstract:
  We prove uniqueness results for a Calderon type inverse problem for the Hodge
Laplacian acting on graded forms on certain manifolds in three dimensions. In
particular, we show that partial measurements of the relative-to-absolute or
absolute-to-relative boundary value maps uniquely determine a zeroth order
potential. The method is based on Carleman estimates for the Hodge Laplacian
with relative or absolute boundary conditions, and on the construction of
complex geometric optics solutions which reduce the Calderon type problem to a
tensor tomography problem for 2-tensors. The arguments in this paper allow to
establish partial data results for elliptic systems that generalize the scalar
results due to Kenig-Sjostrand-Uhlmann.


title:
Smoothed Finite Element and Genetic Algorithm based optimization for
  Shape Adaptive Composite Marine Propellers

abstract:
  An optimization scheme using the Cell-based Smoothed Finite Element Method
(CS-FEM) combined with a Genetic Algorithm (GA) framework is proposed in this
paper to design shape adaptive laminated composite marine propellers. The
proposed scheme utilise the bend-twist coupling characteristics of the
composites to achieve the required performance. An iterative procedure to
evaluate the unloaded shape of the propeller blade is proposed, confirming the
manufacturing requirements at the initial stage. The optimization algorithm and
codes developed in this work were implemented under a variety of parameter
settings and compared against the requirement to achieve an ideally passive
pitch varying propeller. Recommendations for the required thickness of the
propeller blade to achieve optimum bend-twist coupling performance without
resulting large rake deformations are also presented.


title: On the Curvature ODE associated to the Ricci flow

abstract:
  In the vector space of algebraic curvature operators we study the reaction
ODE $$\frac{dR}{dt} = R^2+R^{#}= Q(R)$$ which is associated to the evolution
equation of the Riemann curvature oper- ator along the Ricci flow. More
precisely, we analyze the stability of a special class of zeros of this ODE up
to suitable normalization. In particular, we show that the ODE is unstable near
the curvature operators of the Riemannian product spaces $M \times
\mathbb{R}^k, \ k \geq 0$ where $M$ is an Einstein (locally) symmetric space of
compact type and not a spherical space form when $k = 0.$


title: SQUID-based multichannel system for Magnetoencephalography

abstract:
  Here we present a multichannel system based on superconducting quantum
interference devices (SQUIDs) for magnetoencephalography (MEG) measurements,
developed and installed at Istituto di Cibernetica (ICIB) in Naples. This MEG
system, consists of 163 full integrated SQUID magnetometers, 154 channels and 9
references, and has been designed to meet specifications concerning noise,
dynamic range, slew rate and linearity through optimized design. The control
electronics is located at room temperature and all the operations are performed
inside a Magnetically Shielded Room (MSR). The system exhibits a magnetic white
noise level of approximatively 5 fT/Hz1=2. This MEG system will be employed for
both clinical and routine use. PACS numbers: 74.81.Fa, 85.25.Hv, 07.20.Mc,
85.25.Dq, 87.19.le, 87.85.Ng


title: Highlights from the Pierre Auger Observatory

abstract:
  The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km$^2$ str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X$_{max}$
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.


title:
A stochastic volatility model with flexible extremal dependence
  structure

abstract:
  Stochastic volatility processes with heavy-tailed innovations are a
well-known model for financial time series. In these models, the extremes of
the log returns are mainly driven by the extremes of the i.i.d. innovation
sequence which leads to a very strong form of asymptotic independence, that is,
the coefficient of tail dependence is equal to $1/2$ for all positive lags. We
propose an alternative class of stochastic volatility models with heavy-tailed
volatilities and examine their extreme value behavior. In particular, it is
shown that, while lagged extreme observations are typically asymptotically
independent, their coefficient of tail dependence can take on any value between
$1/2$ (corresponding to exact independence) and 1 (related to asymptotic
dependence). Hence, this class allows for a much more flexible extremal
dependence between consecutive observations than classical SV models and can
thus describe the observed clustering of financial returns more realistically.
The extremal dependence structure of lagged observations is analyzed in the
framework of regular variation on the cone $(0,\infty)^d$. As two auxiliary
results which are of interest on their own we derive a new Breiman-type theorem
about regular variation on $(0,\infty)^d$ for products of a random matrix and a
regularly varying random vector and a statement about the joint extremal
behavior of products of i.i.d. regularly varying random variables.


title: The Model of Magnetic-Field Generation with Screw Dynamo

abstract:
  This paper considers a possibility of magnetic-field generation by local
turbulent flows at the bottom of convective zone. The cycle of magnetic-field
generation in this model can be represented in the form of sequency of
processes. There are vortexes with azimuth axis, similar with Taylor vortex,
close to the bottom of convection zone. This leads to the generation of twisted
flux tubes because of screw dynamo. The growth of magnetic field causes
emersion of U- loops. During the process of emersion and extraction azimuthal
field of flux tubes converts to axial field, and reaches the surface as bipolar
of sunspots with U-shaped configuration. Due to differential rotation residual
bipolar fields stretch out to the surface toroidal field and are shifted to the
bottom of the convective zone by means of meridional flow at high latitudes.
The direction of the toroidal field within the generation zone reverses its
sign, and the cycle is repeated.


title:
Achievement of practical level critical current densities in PIT
  Ba1-xKxFe2As2/Ag tapes by conventional cold mechanical deformation

abstract:
  We found that transport critical current density (Jc) of the Ba1-xKxFe2As2/Ag
tapes is significantly enhanced by the combination process of cold flat rolling
and uniaxial pressing. At 4.2 K, the Jc reaches a high value of 9.1x104 A/cm2
in 4 T, which is almost the practical level of 105 A/cm2. The Jc-H curve shows
extremely small magnetic field dependence and keeps a high value of 6.9x104
A/cm2 in 10 T. These are the highest values reported so far for iron based
superconducting wires. We also show our successful attempts of the fabrication
of multi-filamentary tapes. A high Jc value of 5.3x104 A/cm2 (4.2 K, 10 T) was
obtained in seven-filamentary tapes. The hardness and microstructure
investigations reveal that the superior Jc in uniaxial pressed tape samples is
due to the high core density, more textured grains and the change of microcrack
structure. These results indicate that iron based superconductors are promising
for high magnetic field applications.


title:
Adaptive Distributed Resampling Algorithm with Non-Proportional
  Allocation

abstract:
  The distributed resampling algorithm with proportional allocation (RNA) is
key to implementing particle filtering applications on parallel computer
systems. We extend the original work by Bolic et al. by introducing an adaptive
RNA (ARNA) algorithm, improving RNA by dynamically adjusting the
particle-exchange ratio and randomizing the process ring topology. This
improves the runtime performance of ARNA by about 9% over RNA with 10% particle
exchange. ARNA also significantly improves the speed at which information is
shared between processing elements, leading to about 20-fold faster
convergence. The ARNA algorithm requires only a few modifications to the
original RNA, and is hence easy to implement.


title: Inertial endomorphisms of an abelian group

abstract:
  We describe inertial endomorphisms of an abelian group $A$, that is
endomorphisms $\varphi$ with the property $|(\varphi(X)+X)/X|<\infty$ for each
$X\le A$. They form a ring containing multiplications, the so-called finitary
endomorphisms and non-trivial instances.
  We show that inertial invertible endomorphisms form a group, provided $A$ has
finite torsion-free rank. In any case, the group $IAut(A)$ they generate is
commutative modulo the group $FAut(A)$ of finitary automorphisms, which is
known to be locally finite.
  We deduce that $IAut(A)$ is locally-(center-by-finite).
  Also we consider the lattice dual property, that is that $|X/(X\cap
\varphi(X))|<\infty$ for each $X\le A$. We show that this implies the above
one, provided $A$ has finite torsion-free rank.


title: Local cohomology modules of invariant rings

abstract:
  Let $K$ be a field and let $R$ be a regular domain containing $K$. Let $G$ be
a finite subgroup of the group of automorphisms of $R$. We assume that $|G|$ is
invertible in $K$. Let $R^G$ be the ring of invariants of $G$. Let $I$ be an
ideal in $R^G$. Fix $i \geq 0$.
  If $R^G$ is Gorenstein then,
  \begin{enumerate} \item $injdim_{R^G} H^i_I(R^G) \leq \dim \ Supp \
H^i_I(R^G).$ \item
  $H^j_{\mathfrak{m}}(H^i_I(R^G))$ is injective, where $\mathfrak{m}$ is any
maximal ideal of $R^G$.
  \item
  $\mu_j(P, H^i_I(R^G)) = \mu_j(P^\prime, H^i_{IR}(R))$ where $P^\prime$ is any
prime in $R$ lying above $P$. \end{enumerate}
  We also prove that if $P$ is a prime ideal in $R^G$ with $R^G_P$ \textit{not
Gorenstein} then either the bass numbers $\mu_j(P, H^i_I(R^G)) $ is zero for
all $j$ or there exists $c$ such that $\mu_j(P, H^i_I(R^G)) = 0 $ for $j < c$
and $\mu_j(P, H^i_I(R^G)) > 0$ for all $j \geq c$.


title: T-duality and Scattering of Stringy States

abstract:
  We present a procedure for application of T-duality transformation on
scattering amplitudes of closed bosonic stringy states. These states arise due
to compactification of closed string to lower spacetime dimensions through
dimensional reduction. The amplitude, in the first quantized formalism, is
computed by introducing vertex operators. The amplitude is constructed by the
standard prescription and the vertex operators are required to respect
conformal invariance. Such vertex operators are constructed in the weak field
approximation. Therefore, the vertex operators of the stringy states of our
interest are to be defined accordingly. We propose a prescription to implement
T-duality on the three point functions and N-point functions. We argue that it
is possible to generate new amplitudes through the transformations on a given
amplitude just as T-duality transformations can take us to a new set of string
vacuum when acted upon an initial set. Explicit examples are given for three
point and four point functions.


title: High field magneto-transport study of YBa2Cu3O7-Agx (x = 0.0 to 0.20)

abstract:
  We report high field (up to 13 Tesla) magneto transport R(T)H] of YBa2Cu3O7
(YBCO):Agx (x= 0.0, 0.1 and 0.2) composites. The transport properties are
significantly improved by Ag doping on the insulating grain boundaries of YBCO.
Pure and Ag diffused YBCO superconducting samples are synthesized through solid
state reaction route. Both pure and Ag doped YBCO are superconducting at below
90K. Though, the Tc (R=0) of YBCO:Ag samples under applied field of 13 Tesla is
around 65K, the same is 45K for pure YBCO under same applied field. The upper
critical field [Hc2(0)], being estimated from R(T)H is around 70Tesla for
pristine sample, and is above 190Tesla for Ag doped samples. The boarding of
the resistive transition under applied magnetic field is comparatively less and
nearly single step for Ag doped samples, while the same is clearly two step and
relatively much larger for the pristine YBCO. The resistive broadening is
explained on the basis of changed inter-granular coupling and thermally
activated flux flow (TAFF). The TAFF activation energy (U0) is found to be
linear with applied magnetic field for all the samples, but with nearly an
order of magnitude less value for the Ag doped samples. Summarily, it is shown
that inclusion of Ag significantly improves the superconducting performance of
YBCO:Ag composites, in particular under applied field.


title: Spectral projections of the complex cubic oscillator

abstract:
  We prove the spectral instability of the complex cubic oscillator
$-\frac{d^2}{dx^2}+ix^3+i\alpha x$ for non-negative values of the parameter
$\alpha$, by getting the exponential growth rate of $\|\Pi_n(\alpha)\|$, where
$\Pi_n(\alpha)$ is the spectral projection associated with the $n$-th
eigenvalue of the operator. More precisely, we show that for all non-negative
$\alpha$ \[
  \lim\limits_{n\to+\infty}\frac{1}{n}\log\|\Pi_n(\alpha)\| =
\frac{\pi}{\sqrt{3}}. \]


title:
Response to "Stray-light correction in 2D spectroscopy" by R.
  Schlichenmaier and M. Franz

abstract:
  We discuss a recent paper by Schlichenmaier & Franz (SF; 2013, A&A, 555,
A84), in which the claim is made that the penumbral dark downflows detected for
the first time with the Swedish 1-m Solar Telescope (SST) by Scharmer et al.
and Joshi et al. could be produced by overcompensation for straylight. We show
that the analysis of SF is fundamentally flawed, because it ignores the
constraints on the strength of such straylight from 3D convection simulations
and on the spatial extent of the straylight point spread function from the
measured minimum intensity in the sunspot umbra. Furthermore, we show that the
claim made by SF, that the spatial straylight of Hinode is less than 10%, is
false. We conclude that the analysis of SF is of no relevance in relation to
the straylight compensation method applied to the SST data.


title: Parameters Influencing the Optical Properties Of SnS Thin Films

abstract:
  Tin Sulphide (SnS) thin films have been recognized as a potential candidate
for solar cells. Many fabrication techniques have been used to grow SnS thin
films. The band-gap, ${\rm E_g}$ of SnS films as reported in literature, were
found to vary from 1.2-2.5 eV depending on the film fabrication technique. The
present work reports the structural, compositional, morphological and optical
characterization of SnS thin films fabricated by thermal evaporation at room
temperature. Results show that for the given fabrication technique/ condition,
the band-gap functionally depends on the lattice parameter and grain size. The
well-defined variation allows for tailoring SnS film as per requirement.


title: MAC-aware Routing Metrics for the Internet of Things

abstract:
  Wireless medium access control (MAC) and routing protocols are fundamental
building blocks of the Internet of Things (IoT). As new IoT networking
standards are being proposed and different existing solutions patched,
evaluating the end-to-end performance of the network becomes challenging.
Specific solutions designed to be beneficial, when stacked may have detrimental
effects on the overall network performance. In this paper, an analysis of MAC
and routing protocols for IoT is provided with focus on the IEEE 802.15.4 MAC
and the IETF RPL standards. It is shown that existing routing metrics do not
account for the complex interactions between MAC and routing, and thus novel
metrics are proposed. This enables a protocol selection mechanism for selecting
the routing option and adapting the MAC parameters, given specific performance
constraints. Extensive analytical and experimental results show that the
behavior of the MAC protocol can hurt the performance of the routing protocol
and vice versa, unless these two are carefully optimized together by the
proposed method.


title:
Matching-centrality decomposition and the forecasting of new links in
  networks

abstract:
  Networks play a prominent role in the study of complex systems of interacting
entities in biology, sociology, and economics. Despite this diversity, we
demonstrate here that a statistical model decomposing networks into matching
and centrality components provides a comprehensive and unifying quantification
of their architecture. First we show, for a diverse set of networks, that this
decomposition provides an extremely tight fit to observed networks.
Consequently, the model allows very accurate prediction of missing links in
partially known networks. Second, when node characteristics are known, we show
how the matching-centrality decomposition can be related to this external
information. Consequently, it offers a simple and versatile tool to explore how
node characteristics explain network architecture. Finally, we demonstrate the
efficiency and flexibility of the model to forecast the links that a novel node
would create if it were to join an existing network.


title: Superconductivity in layered CeO0.5F0.5BiS2

abstract:
  We report appearance of superconductivity in CeO0.5F0.5BiS2. The bulk
polycrystalline samples CeOBiS2 and CeO0.5F0.5BiS2 are synthesized by
conventional solid state reaction route via vacuum encapsulation technique.
Detailed structural analysis showed that the studied CeO0.5F0.5BiS2 compound is
crystallized in tetragonal P4/nmm space group with lattice parameters a =
4.016(3) A, c = 13.604(2) A. DC magnetization measurement (MT-curve) shows the
ferromagnetic signal at the low temperature region. The superconductivity is
established in CeO0.5F0.5BiS2 at Tconset = 2.5K by electrical transport
measurement. Under applied magnetic field both Tc onset and Tc ({\rho} =0)
decrease to lower temperatures and an upper critical field [Hc2(0)] above
1.2Tesla is estimated. The results suggest coexistence of ferromagnetism and
superconductivity for the CeO0.5F0.5BiS2 sample.


title: On the Iwahori-Weyl group

abstract:
  Let $F$ be a discretely valued complete field with valuation ring
$\mathcal{O}_F$ and perfect residue field $k$ of cohomological dimension $\leq
1$. In this paper, we generalize the Bruhat decomposition in Bruhat and Tits
from the case of simply connected $F$-groups to the case of arbitrary connected
reductive $F$-groups. If $k$ is algebraically closed, Haines and Rapoport
define the Iwahori-Weyl group, and use it to solve this problem. Here we define
the Iwahori-Weyl group in general, and relate our definition of the
Iwahori-Weyl group to that of Haines and Rapoport. Furthermore, we study the
length function on the Iwahori-Weyl group, and use it to determine the number
of points in a Bruhat cell, when $k$ is a finite field.


title: Discrete KP equation with self-consistent sources

abstract:
  We show that the discrete Kadomtsev-Petviashvili (KP) equation with sources
obtained recently by the "source generalization" method can be incorporated
into the squared eigenfunction symmetry extension procedure. Moreover, using
the known correspondence between Darboux-type transformations and additional
independent variables, we demonstrate that the equation with sources can be
derived from Hirota's discrete KP equations but in a space of higher dimension.
In this way we uncover the origin of the source terms as coming from
multidimensional consistency of the Hirota system itself.


title: Higher-order Daehee numbers and polynomials

abstract:
  Recently, Daehee numbers and polynomials are introduced by the authors. In
this paper, we consider the Daehee numbers and polynomials of order k and give
some relation between Daehee polynomials of order k and special polynomials


title:
Using multiobjective optimization to map the entropy region of four
  random variables

abstract:
  Presently the only available method of exploring the 15-dimensional entropy
region formed by the entropies of four random variables is the one of Zhang and
Yeung from 1998. It is argued that their method is equivalent to solving linear
multiobjective optimization problems. Benson's outer approximation algorithm is
a fundamental tool for solving these optimization problems. An improved version
of Benson's algorithm is described which requires solving one scalar linear
program in each iteration rather than two or three as in previous versions.
During the algorithm design special care was taken for numerical stability. The
implemented algorithm was used to check previous statements about the entropy
region, and to gain new information on that region. The experimental results
demonstrate the viability of the method for determining the extremal set of
medium size, numerically ill-posed optimization problems. With growing problem
size two limitations of Benson's algorithm have been observed: the inefficiency
of the scalar LP solver on one hand and the unexpectedly large number of
intermediate vertices on the other.


title: Annihilators and Type Decomposition in C*-Algebras

abstract:
  We initiate the study of annihilators in C*-algebras, showing that they are,
in many ways, the best C*-algebra analogs of projections in von Neumann
algebras. Using them, we obtain a type decomposition for arbitrary C*-algebras
that is symmetric and completely consistent with the classical von Neumann
algebra type decomposition. We also show that annihilators admit a very simple
notion of equivalence that is again completely consistent with the notion of
Murray-von Neumann equivalence in von Neumann algebras, sharing many of its
general order theoretic properties.


title: Secret sharing on the $d$-dimensional cube

abstract:
  We prove that for $d>1$ the best information ratio of the perfect secret
sharing scheme based on the edge set of the $d$-dimensional cube is exactly
$d/2$. Using the technique developed, we also prove that the information ratio
of the infinite $d$-dimensional lattice is $d$.


title: Optomechanical elastomeric engine

abstract:
  Nematic elastomers contract along their director when heated or illuminated
(in the case of photoelastomers). We present a conceptual design for an
elastomer-based engine to extract mechanical work from heat or light. The
material parameters and the geometry of such an engine are explored, and it is
shown that its efficiency can go up to 20%.


title: Cell decompositions of double Bott-Samelson varieties

abstract:
  Let G be a connected complex semisimple Lie group. Webster and Yakimov have
constructed partitions of the double flag variety G/B x G/B_, where (B, B_) is
a pair of opposite Borel subgroups of G, generalizing the Deodhar
decompositions of G/B. We show that these partitions can be better understood
by constructing cell decompositions of a product of two Bott-Samelson varieties
Z_{u, v}, where u and v are sequences of simple reflections. We construct
coordinates on each cell of the decompositions and in the case of a positive
subexpression, we relate these coordinates to regular functions on a particular
open subset of Z_{u, v}.
  Our motivation for constructing cell decompositions of Z_{u,v} was to study a
certain natural Poisson structure on Z_{u,v}.


title:
Large time behavior of the on-diagonal heat kernel for minimal
  submanifolds with polynomial volume growth

abstract:
  In this paper we provide a lower bound for the long time on-diagonal heat
kernel of minimal submanifolds in a Cartan-hadamard ambient manifold assuming
that the submanifold is of polynomial volume growth. In particular cases, that
lower bound is related with the number of ends of the submanifold.


title:
On reducibility points beyond ends of complementary series of p-adic
  GL(n)

abstract:
  In this paper we consider reducibility points beyond the ends of
complementary series of general linear groups over a p-adic field, which start
with Speh representations. We describe explicitly the composition series of the
representations at these reducibility points. They are multiplicities one
representations, and they can be of arbitrary length. We give Langlands
parameters of all the irreducible subquotients.


title: A Greedy Algorithm for Optimally Pipelining a Reduction

abstract:
  Collective communications are ubiquitous in parallel applications. We present
two new algorithms for performing a reduction. The operation associated with
our reduction needs to be associative and commutative. The two algorithms are
developed under two different communication models (unidirectional and
bidirectional). Both algorithms use a greedy scheduling scheme. For a
unidirectional, fully connected network, we prove that our greedy algorithm is
optimal when some realistic assumptions are respected. Previous algorithms fit
the same assumptions and are only appropriate for some given configurations.
Our algorithm is optimal for all configurations. We note that there are some
configuration where our greedy algorithm significantly outperform any existing
algorithms. This result represents a contribution to the state-of-the art. For
a bidirectional, fully connected network, we present a different greedy
algorithm. We verify by experimental simulations that our algorithm matches the
time complexity of an optimal broadcast (with addition of the computation).
Beside reversing an optimal broadcast algorithm, the greedy algorithm is the
first known reduction algorithm to experimentally attain this time complexity.
Simulations show that this greedy algorithm performs well in practice,
outperforming any state-of-the-art reduction algorithms. Positive experiments
on a parallel distributed machine are also presented.


title: $U(1)_{B-L}$ extra-natural inflation with Standard Model on a brane

abstract:
  The interrelation between inflationary cosmology and new physics beyond the
Standard Model (SM) is studied in a $U(1)_{B-L}$ extension of the SM embedded
in a (4+1)-dimensional spacetime. In the scenario we study, the inflaton arises
from the Wilson loop of the $U(1)_{B-L}$ gauge group winding an
extra-dimensional cycle. Particular attention is paid to the coupling between
the inflaton and SM particles that are confined on a brane localised in the
extra dimension. We find that the inflaton decay channels are rather restricted
in this scenario and the resulting reheating temperature is relatively low.


title: Census Data Mining and Data Analysis using WEKA

abstract:
  Data mining (also known as knowledge discovery from databases) is the process
of extraction of hidden, previously unknown and potentially useful information
from databases. The outcome of the extracted data can be analyzed for the
future planning and development perspectives. In this paper, we have made an
attempt to demonstrate how one can extract the local (district) level census,
socio-economic and population related other data for knowledge discovery and
their analysis using the powerful data mining tool Weka.


title: Low Energy alpha-alpha Semimicroscopic Potentials

abstract:
  The $\alp-\alp$ interaction potential is obtained within the double folding
model with density-dependent Gogny effective interactions as input. The one
nucleon knock-on exchange kernel including recoil effects is localized using
the Perey-Saxon prescription at zero energy. The Pauli forbidden states are
removed thanks to successive supersymmetric transformations. Low energy
experimental phase shifts, calculated from the variable phase approach, as well
as the energy and width of the first $0^+$ resonance in $^8$Be are reproduced
with high accuracy.


title: Solar Flare Impulsive Phase Emission Observed with SDO/EVE

abstract:
  Differential emission measures (DEMs) during the impulsive phase of solar
flares were constructed using observations from the EUV Variability Experiment
(EVE) and the Markov-Chain Monte Carlo method. Emission lines from ions formed
over the temperature range log T = 5.8 - 7.2 allow the evolution of the DEM to
be studied over a wide temperature range at 10s cadence. The technique was
applied to several M- and X-class flares, where impulsive phase EUV emission is
observable in the disk-integrated EVE spectra from emission lines formed up to
3 - 4 MK, and we use spatially-unresolved EVE observations to infer the thermal
structure of the emitting region. For the nine events studied the DEMs
exhibited a two component distribution during the impulsive phase, a low
temperature component with peak temperature of 1 - 2 MK, and a broad high
temperature one from 7 - 30 MK. A bimodal high temperature component is also
found for several events, with peaks at 8 and 25 MK during the impulsive phase.
The origin of the emission was verified using AIA images to be the flare
ribbons and footpoints, indicating that the constructed DEMs represent the
spatially-average thermal structure of the chromospheric flare emission during
the impulsive phase.


title:
The generation and damping of propagating MHD kink waves in the solar
  atmosphere

abstract:
  The source of the non-thermal energy required for the heating of the upper
solar atmosphere to temperatures in excess of a million degrees and the
acceleration of the solar wind to hundreds of kilometres per second is still
unclear. One such mechanism for providing the required energy flux is
incompressible torsional Alfv\'en and kink magnetohydrodynamic (MHD) waves,
which are magnetically dominated waves supported by the Sun's pervasive and
complex magnetic field. In particular, propagating MHD kink waves have recently
been observed to be ubiquitous throughout the solar atmosphere, but, until now,
critical details of the transport of the kink wave energy throughout the Sun's
atmosphere were unclear. Here, the ubiquity of the waves is exploited for
statistical studies in the highly dynamic solar chromosphere. This large-scale
investigation allows for the determination of the chromospheric kink wave
velocity power spectra, a missing link necessary for determining the energy
transport between the photosphere and corona. Crucially, the power spectra
contains evidence for horizontal photospheric motions being the main mechanism
for kink wave generation in the quiescent Sun. In addition, a comparison to
measured coronal power spectra is provided, revealing frequency-dependent
transmission profiles suggesting there is enhanced damping of kink waves in the
lower corona.


title:
Variation of proton flux profiles with the observer's latitude in
  simulated gradual SEP events

abstract:
  We study the variation of the shape of the proton intensity-time profiles in
simulated gradual Solar Energetic Particle (SEP) events with the relative
observer's position in space with respect to the main direction of propagation
of an interplanetary (IP) shock. Using a three-dimensional (3D)
magnetohydrodynamic (MHD) code to simulate such a shock, we determine the
evolution of the downstream-to-upstream ratios of the plasma variables at its
front. Under the assumption of an existing relation between the normalized
ratio in speed across the shock front and the injection rate of
shock-accelerated particles, we model the transport of the particles and we
obtain the proton flux profiles to be measured by a grid of 18 virtual
observers located at 0.4 and 1.0 AU, with different latitudes and longitudes
with respect to the shock nose. The differences among flux profiles are the
result of the way each observer establishes a magnetic connection with the
shock front, and we find that changes in the observer's latitude may result in
intensity changes of up to one order of magnitude at both radial distances
considered here. The peak intensity variation with the radial distance for the
pair of observers located at the same angular position is also derived. This is
the first time that the latitudinal dependence of the peak intensity with the
observer's heliocentric radial distance has been quantified within the
framework of gradual SEP event simulations.


title: Gruppen secret sharing, or, how to share several secrets if you must?

abstract:
  Each member of an $n$-person team has a secret, say a password. The $k$ out
of $n$ gruppen secret sharing requires that any group of $k$ members should be
able to recover the secrets of the other $n-k$ members, while any group of
$k-1$ or less members should have no information on the secret of other team
member even if other secrets leak out. We prove that when all secrets are
chosen independently and have size $s$, then each team member must have a share
of size at least $(n-k)s$, and we present a scheme which achieves this bound
when $s$ is large enough. This result shows a significant saving over $n$
independent applications of Shamir's $k$ out of $n-1$ threshold schemes which
assigns shares of size $(n-1)s$ to each team member independently of $k$.
  We also show how to set up such a scheme without any trusted dealer, and how
the secrets can be recovered, possibly multiple times, without leaking
information. We also discuss how our scheme fits to the much-investigated
multiple secret sharing methods.


title: Diameter and Girth of Zero Divisor Graph of Multiplicative Lattices

abstract:
  In this paper, we study the zero divisor graph $\Gamma^m(L)$ of a
multiplicative lattice L. We prove under certain conditions that for a reduced
multiplicative lattice L having more than two minimal prime elements,
$\Gamma^m(L)$ contains a cycle and $gr(\Gamma^m(L)) = 3$. This essentially
proves that for a reduced ring R with more than two minimal primes,
$gr(\mathbb{AG}(R))) = 3$ which settles the conjecture of Behboodi and Rakeei
[9]. Further, we have characterized the diameter of $\Gamma^m(L)$.


title:
de Rham cohomology of $H^1_{(f)}(R)$ where $V(f)$ is a smooth
  hypersurface in $\mathbb{P}^n$

abstract:
  Let $K$ be a field of characteristic zero, $R = K[X_1,\ldots,X_n]$. Let
$A_n(K) = K<X_1,\ldots,X_n, \partial_1, \ldots, \partial_n>$ be the $n^{th}$
Weyl algebra over $K$. We consider the case when $R$ and $A_n(K)$ is graded by
giving $\deg X_i = \omega_i $ and $\deg \partial_i = -\omega_i$ for $i
=1,\ldots,n$ (here $\omega_i$ are positive integers). Set $\omega =
\sum_{k=1}^{n}\omega_k$. Let $I$ be a graded ideal in $R$. By a result due to
Lyubeznik the local cohomology modules $H^i_I(R)$ are holonomic
$A_n(K)$-modules for each $i \geq 0$. In this article we compute the de Rham
cohomology modules $H^j(\mathbb{\partial}; H^1_{(f)}(R))$ for $j \leq n-2$ when
$V(f)$ is a smooth hypersurface in $\mathbb{P}^n$ (equivalently $A = R/(f)$ is
an isolated singularity).


title:
The Recurrence Rate and Hausdorff Dimension of a Neighbourhood of some
  Typical Point in the Julia Set of a Rational Map

abstract:
  In this article, we consider hyperbolic rational maps restricted on thier
Julia sets and study about the recurrence rate of typical orbits in arbitrarily
small neighbourhoods around them and their relationship to the Hausdorff
dimension of such small neighbourhoods.


title: Maximizing Barber's bipartite modularity is also hard

abstract:
  Modularity introduced by Newman and Girvan [Phys. Rev. E 69, 026113 (2004)]
is a quality function for community detection. Numerous methods for modularity
maximization have been developed so far. In 2007, Barber [Phys. Rev. E 76,
066102 (2007)] introduced a variant of modularity called bipartite modularity
which is appropriate for bipartite networks. Although maximizing the standard
modularity is known to be NP-hard, the computational complexity of maximizing
bipartite modularity has yet to be revealed. In this study, we prove that
maximizing bipartite modularity is also NP-hard. More specifically, we show the
NP-completeness of its decision version by constructing a reduction from a
classical partitioning problem.


title: Wake in anisotropic Quark-Gluon Plasma

abstract:
  We calculate the wake in charge density and the wake potential due to the
passage of a fast parton in an anisotropic quark gluon plasma(AQGP). For the
sake of simplicity small $\xi$(anisotropic parameter) limit has been
considered. When the velocity($v$) of the jet is parallel to the anisotropy
direction(${\hat n}$) and remains below the phase velocity($v_p$), the wake in
induced charge density shows a little oscillatory behavior in AQGP, contrary to
the isotropic case. With the jet velocity greater than the phase velocity, the
oscillatory behavior increases with $\xi$. Also for $v>v_p$ one observes a
clear modification of the cone-like structure in presence of anisotropy. For
the parallel direction in the backward region, the depth of the wake potential
decreases with the increase of $\xi$ for $v<v_p$ and the potential becomes
modified Coulomb-like for higher values of $\xi$. In the forward region, the
potential remains modified Coulomb-like with the change in magnitude for
nonzero $\xi$, for both $v>v_p$ and $v<v_p$. In the perpendicular direction,
the wake potential is symmetric in the forward and backward regions. With the
increase of $\xi$, the depth of negative minimum is moving away from the origin
irrespective of the jet velocity. On the other hand when the jet velocity is
perpendicular to the anisotropy direction, we find significant changes in the
case of both wake charge density and potential in comparison to the isotropic
case.


title: Exceptional Meixner and Laguerre orthogonal polynomials

abstract:
  Using Casorati determinants of Meixner polynomials $(m_n^{a,c})_n$, we
construct for each pair $\F=(F_1,F_2)$ of finite sets of positive integers a
sequence of polynomials $m_n^{a,c;\F}$, $n\in \sigma_\F$, which are
eigenfunctions of a second order difference operator, where $\sigma_\F$ is
certain infinite set of nonnegative integers, $\sigma_\F \varsubsetneq \NN$.
When $c$ and $\F$ satisfy a suitable admissibility condition, we prove that the
polynomials $m_n^{a,c;\F}$, $n\in \sigma_\F$, are actually exceptional Meixner
polynomials; that is, in addition, they are orthogonal and complete with
respect to a positive measure. By passing to the limit, we transform the
Casorati determinant of Meixner polynomials into a Wronskian type determinant
of Laguerre polynomials $(L_n^\alpha)_n$. Under the admissibility conditions
for $\F$ and $\alpha$, these Wronskian type determinants turn out to be
exceptional Laguerre polynomials.


title: On the pressure exerted by a bundle of independent living filaments

abstract:
  The properties of a bundle of grafted semi-flexible living filaments in ideal
solution facing an obstacle wall, under supercritical conditions, are explored.
For this purpose, we make use of the discrete wormlike chain model
characterized by the monomer size $d$, a size dependent contour length $L_{\rm
c}$ and a persistence length $l_{\rm p}$. The calculation of the equilibrium
filament size distribution and the average equilibrium force require the
knowledge of the wall effect on the single filament partition function of any
size, which can be computed by Metropolis Monte-Carlo methods. The force
exerted by a living filament on a fixed wall turns out to be the weighted
average of the dead grafted filament forces computed for sizes hitting the
wall, multiplied by the probability of occurrence of the corresponding filament
size. As the distance to the wall is varied, the resultant force shows large
variations whose amplitude decrease with increasing gap sizes and/or with
decreasing persistence length. Also, its average over a gap interval of precise
size $d$ gives an average force close to what is expected by the ratchet model
for actin growth against a wall. The osmotic pressure exerted by $N_f$
filaments is the average equilibrium force per filament times the grafting
surface density.


title: Wake potential in collisional anisotropic quark-gluon plasma

abstract:
  Within the framework of Boltzmann transport equation with a
Bhatnagar-Gross-Krook (BGK) collisional kernel, we study the wake potential
induced by fast partons traveling through the high-temperature QCD plasma which
is anisotropic in momentum-space. We calculate the dielectric response function
of a collisional anisotropic quark-gluon plasma (AQGP) for small $\xi$
(anisotropic parameter) limit. Using this, the wake potential for various
combinations of the anisotropy parameter ($\xi$) and the collision rate ($\nu$)
is evaluated both for parallel and perpendicular directions of motion of the
fast parton. It is seen that the inclusion of the collision modifies the wake
potential and the amount as well as the nature of the potential depends on the
combinations of $\xi$ and $\nu$


title: Minimax rates in permutation estimation for feature matching

abstract:
  The problem of matching two sets of features appears in various tasks of
computer vision and can be often formalized as a problem of permutation
estimation. We address this problem from a statistical point of view and
provide a theoretical analysis of the accuracy of several natural estimators.
To this end, the minimax rate of separation is investigated and its expression
is obtained as a function of the sample size, noise level and dimension. We
consider the cases of homoscedastic and heteroscedastic noise and establish, in
each case, tight upper bounds on the separation distance of several estimators.
These upper bounds are shown to be unimprovable both in the homoscedastic and
heteroscedastic settings. Interestingly, these bounds demonstrate that a phase
transition occurs when the dimension $d$ of the features is of the order of the
logarithm of the number of features $n$. For $d=O(\log n)$, the rate is
dimension free and equals $\sigma (\log n)^{1/2}$, where $\sigma$ is the noise
level. In contrast, when $d$ is larger than $c\log n$ for some constant $c>0$,
the minimax rate increases with $d$ and is of the order $\sigma(d\log
n)^{1/4}$. We also discuss the computational aspects of the estimators and
provide empirical evidence of their consistency on synthetic data. Finally, we
show that our results extend to more general matching criteria.


title:
The Air Microwave Yield (AMY) experiment - A laboratory measurement of
  the microwave emission from extensive air showers

abstract:
  The AMY experiment aims to measure the microwave bremsstrahlung radiation
(MBR) emitted by air-showers secondary electrons accelerating in collisions
with neutral molecules of the atmosphere. The measurements are performed using
a beam of 510 MeV electrons at the Beam Test Facility (BTF) of Frascati INFN
National Laboratories. The goal of the AMY experiment is to measure in
laboratory conditions the yield and the spectrum of the GHz emission in the
frequency range between 1 and 20 GHz. The final purpose is to characterise the
process to be used in a next generation detectors of ultra-high energy cosmic
rays. A description of the experimental setup and the first results are
presented.


title: Lyapunov theorem for q-concave Banach spaces

abstract:
  Generalization of Lyapunov convexity theorem is proved for vector measure
with values in Banach spaces with unconditional bases, which are q-concave for
some $q<\infty.$


title: SVD Factorization for Tall-and-Fat Matrices on Map/Reduce Architectures

abstract:
  We demonstrate an implementation for an approximate rank-k SVD factorization,
combining well-known randomized projection techniques with previously
implemented map/reduce solutions in order to compute steps of the random
projection based SVD procedure, such QR and SVD. We structure the problem in a
way that it reduces to Cholesky and SVD factorizations on $k \times k$ matrices
computed on a single machine, greatly easing the computability of the problem.


title:
Lee-Yang cluster expansion approach to the BCS-BEC crossover: BCS and
  BEC limits

abstract:
  It is shown that a cluster expansion technique, which is usually applied in
the high-temperature regime to calcutate virial coefficients, can be applied to
evaluate the superfluid transition temperature of the BCS-BEC crossover \`a la
Lee and Yang. The transition temperature is identified with the emergence of
the singularity in the sum of a certain infinite series of cluster functions.
In the weak-coupling limit, we reproduce the Thouless criterion and the number
equation of Nozi\`eres and Schmitt-Rink, and hence the transition temperature
of the BCS theory. In the strong-coupling limit, we reproduce the transition
temperature of Bose-Einstein condensation of non-interacting tightly bound
dimers.

categories: cond-mat.quant-gas cond-mat.str-el cond-mat.supr-con nucl-th


title: Large monochromatic triple stars in edge colourings

abstract:
  Following problems posed by Gy\'arf\'as, we show that for every
$r$-edge-colouring of $K_n$ there is a monochromatic triple star of order at
least $n/(r-1)$, improving a previous result by Ruszink\'o.
  An edge colouring of a graph is called a local $r$-colouring if every vertex
spans edges of at most $r$ distinct colours. We prove the existence of a
monochromatic triple star with at least $rn/(r^2-r+1)$ vertices in every local
$r$-colouring of $K_n$.


title: Enhanced Learning with Web-Assisted Education

abstract:
  An educational system, the tutor-web (http://tutor-web.net), has been
developed and used for educational research. The system is accessible and free
to use for anyone having access to the Web. It is based on open source software
and the teaching material is licensed under the Creative Commons
Attribution-ShareAlike License. The system has been used for computer-assisted
education in statistics and mathematics. It offers a unique way to structure
and link together teaching material and includes interactive quizzes with the
primary purpose of increasing learning rather than mere evaluation.
  The system was used in a course on basic statistics in 2011. Three types of
data were gathered during the course. A randomized crossover experiment was
conducted to assess the possible difference in learning (measured by repeated
exams) between students using the system and students doing regular homework.
The difference between the groups was not found to be significant. Responses to
quiz questions were collected and analysed with item response theory type
models. These analysis were used to improve the item banks. Finally, the
students answered an in-class survey regarding their experience using the
tutor-web. The responses of the students gave clear indications of student
preferences.


title:
A spectroscopic fingerprint of electron correlation in high temperature
  superconductors

abstract:
  The so-called "strange metal phase" [1] of high temperature (high Tc)
superconductors remains at the heart of the high Tc mystery. Better
experimental data and insightful theoretical work would improve our
understanding of this enigmatic phase. In particular, the recent advance in
angle resolved photoelectron spectroscopy (ARPES) [2, 3], incorporating low
photon energies (about 7 eV), has given a much more refined view of the many
body interaction in these materials. Here, we report a new ARPES feature of
Bi2Sr2CaCu2O8+d that we demonstrate to have the key ability to distinguish
between different classes of theories of the normal state. This feature---the
anomaly in the nodal many body density of states (nMBDOS)---is clearly observed
in the low energy ARPES data, but also observed in more conventional high
energy ARPES data, when a sufficient temperature range is covered. We show that
key characteristics of this anomaly are explained by a strong electron
correlation model; the electron-hole asymmetry and the momentum dependent self
energy emerge as key required ingredients.


title: On the disruption of pulsar and X-ray binaries in globular clusters

abstract:
  The stellar encounter rate Gamma has been shown to be strongly correlated
with the number of X-ray binaries in clusters and also to the number of radio
pulsars. However, the pulsar populations in different clusters show remarkably
different characteristics: in some GCs the population is dominated by binary
systems, in others by single pulsars and exotic systems that result from
exchange encounters. In this paper, we describe a second dynamical parameter
for globular clusters, the encounter rate for a single binary, gamma. We find
that this parameter provides a good characterization of the differences between
the pulsar populations of different globular clusters. The higher gamma is for
any particular globular cluster the more isolated pulsars and products of
exchange interactions are observed. Furthermore, we also find that slow and
"young" pulsars are found almost exclusively in clusters with a high gamma;
this suggests that these kinds of objects are formed by the disruption of X-ray
binaries, thus halting the recycling of a previously dead neutron star. We
discuss the implications of this for the nature of young pulsars and for the
formation of neutron stars in globular clusters.


title:
The 72-Hour WEBT Microvariability Observation of Blazar S5 0716+714 in
  2009

abstract:
  Context. The international whole earth blazar telescope (WEBT) consortium
planned and carried out three days of intensive micro-variability observations
of S5 0716+714 from February 22, 2009 to February 25, 2009. This object was
chosen due to its bright apparent magnitude range, its high declination, and
its very large duty cycle for micro-variations. Aims. We report here on the
long continuous optical micro-variability light curve of 0716+714 obtained
during the multi-site observing campaign during which the Blazar showed almost
constant variability over a 0.5 magnitude range. The resulting light curve is
presented here for the first time. Observations from participating
observatories were corrected for instrumental differences and combined to
construct the overall smoothed light curve. Methods. Thirty-six observatories
in sixteen countries participated in this continuous monitoring program and
twenty of them submitted data for compilation into a continuous light curve.
The light curve was analyzed using several techniques including Fourier
transform, Wavelet and noise analysis techniques. Those results led us to model
the light curve by attributing the variations to a series of synchrotron
pulses. Results. We have interpreted the observed microvariations in this
extended light curve in terms of a new model consisting of individual
stochastic pulses due to cells in a turbulent jet which are energized by a
passing shock and cool by means of synchrotron emission. We obtained an
excellent fit to the 72-hour light curve with the synchrotron pulse model.


title:
The Influence of Ca and Y on the Microstructure and Corrosion Resistance
  of Vacuum Die Casting AZ91 Alloy

abstract:
  The influence of Ca and Y on the microstructure and corrosion resistance of
vacuum die casting AZ91 alloy is investigated using optical microscope,
electron scanning microscope, weight-loss test and electrochemical corrosion
test. The results indicate that the microstructure of AZ91 alloy can be
refined, amount of Mg17Al12 phases is reduced, making Mg17Al12 phases transform
from banding to reticular, and stringer Al2Ca phases and block Al2Y phases are
formed through adding both Ca and Y. The corrosion resistance of AZ91 magnesium
alloy can be increased greatly by adding both Ca and Y. The corrosion rate of
AZ91-1.5Ca-1.0Y alloy is dropped to 16.2% of that of AZ91 alloy immersed in
3.5% NaCl aqueous solution for 24 hours. The corrosion current density of
AZ91-1.5Ca-1.0Y alloy is dropped by one order of magnitude.


title:
On the structure of semigroups on $L_p$ with a bounded
  $H{^\infty}$-calculus

abstract:
  We show that a bounded analytic semigroup on an $L_p$-space has a bounded
$H^{\infty}(\Sigma_{\varphi})$-calculus for some $\varphi < \frac{\pi}{2}$ if
and only if the semigroup can be obtained, after restricting to invariant
subspaces, factorizing through invariant subspaces and similarity transforms,
from a bounded analytic semigroup on some bigger $L_p$-space which is positive
and contractive on the real line.


title: Complex dynamics with focus on the real parts

abstract:
  We consider the dynamics of holomorphic polynomials in $\mathbb C$. We show
that the ergodic properties of the map can be seen already from the real parts
of the orbits.


title: Spiral Structure Dynamics in Pure Stellar Disk Models

abstract:
  In order to understand the physical mechanism underlying non-steady stellar
spiral arms in disk galaxies we performed a series of N-body simulations with
1.2 and 8 million particles. The initial conditions were chosen to follow
Kuijken-Dubinski models. In this work we present the results of a sub-sample of
our simulations in which we experiment with different disk central radial
velocity dispersion and the disk scale height.


title:
Forward physics with tagged protons at the LHC: QCD and anomalous
  couplings

abstract:
  We present some physics topics that can be studied at the LHC using proton
tagging. We distinguish the QCD (Pomeron structure, BFKL analysis...) from the
exploratory physics topics (HIggs boson, anomalous couplings between photons
and $W/Z$ bosons


title: Strictly stationary solutions of spatial ARMA equations

abstract:
  The generalization of the ARMA time series model to the multidimensional
index set $\mathbb{Z}^d$, $d\ge2$, is called spatial ARMA model. The purpose of
the following is to specify necessary conditions and sufficient conditions for
the existence of strictly stationary solutions of the ARMA equations when the
driving noise is i.i.d. Two different classes of strictly stationary solutions
are studied, solutions of causal and non-causal models. For the special case of
a first order model on $\mathbb{Z}^2$ conditions are obtained, which are
simultaneously necessary and sufficient.


title:
Quantum Langevin equation approach to electromagnetic energy transfer
  between dielectric bodies in an inhomogeneous environment

abstract:
  Near-field and resonance effects have a strong influence on the nanoscale
electromagnetic energy transfer, and detailed understanding of these effects is
required for the design of new, optimized nano-optical devices. We provide a
comprehensive microscopic view of electromagnetic energy transfer phenomena by
introducing quantum Langevin heat baths as local noise sources in the equations
of motion for the thermally fluctuating electric dipoles forming dielectric
bodies. The theory is, in a sense, the microscopic generalization of the
well-known fluctuational electrodynamics theory and thereby provides an
alternative and conceptually simple way to calculate the local emission and
absorption rates from the local Langevin bath currents. We apply the model to
study energy transfer between silicon carbide nanoparticles located in a
microcavity formed of two mirrors and next to a surface supporting propagating
surface modes. The results show that the heat current between the dipoles
placed in a cavity oscillates as a function of their position and distance and
can be enhanced by several orders of magnitude as compared to the free space
heat current with a similar interparticle distance. The predicted enhancement
can be viewed as a many-body generalization of the well-known cavity Purcell
effect. Similar effects are also observed in the interparticle heat transfer
between dipoles located next to a surface of a polar material supporting
surface phonon polaritons.


title: Detecting gradual changes in locally stationary processes

abstract:
  In a wide range of applications, the stochastic properties of the observed
time series change over time. The changes often occur gradually rather than
abruptly: the properties are (approximately) constant for some time and then
slowly start to change. In many cases, it is of interest to locate the time
point where the properties start to vary. In contrast to the analysis of abrupt
changes, methods for detecting smooth or gradual change points are less
developed and often require strong parametric assumptions. In this paper, we
develop a fully nonparametric method to estimate a smooth change point in a
locally stationary framework. We set up a general procedure which allows us to
deal with a wide variety of stochastic properties including the mean,
(auto)covariances and higher moments. The theoretical part of the paper
establishes the convergence rate of the new estimator. In addition, we examine
its finite sample performance by means of a simulation study and illustrate the
methodology by two applications to financial return data.