title:
The coalescing-branching random walk on expanders and the dual epidemic
  process

abstract:
  Information propagation on graphs is a fundamental topic in distributed
computing. One of the simplest models of information propagation is the push
protocol in which at each round each agent independently pushes the current
knowledge to a random neighbour. In this paper we study the so-called
coalescing-branching random walk (COBRA), in which each vertex pushes the
information to $k$ randomly selected neighbours and then stops passing
information until it receives the information again. The aim of COBRA is to
propagate information fast but with a limited number of transmissions per
vertex per step. In this paper we study the cover time of the COBRA process
defined as the minimum time until each vertex has received the information at
least once. Our main result says that if $G$ is an $n$-vertex $r$-regular graph
whose transition matrix has second eigenvalue $\lambda$, then the COBRA cover
time of $G$ is $\mathcal O(\log n )$, if $1-\lambda$ is greater than a positive
constant, and $\mathcal O((\log n)/(1-\lambda)^3))$, if $1-\lambda \gg
\sqrt{\log( n)/n}$. These bounds are independent of $r$ and hold for $3 \le r
\le n-1$. They improve the previous bound of $O(\log^2 n)$ for expander graphs.
Our main tool in analysing the COBRA process is a novel duality relation
between this process and a discrete epidemic process, which we call a biased
infection with persistent source (BIPS). A fixed vertex $v$ is the source of an
infection and remains permanently infected. At each step each vertex $u$ other
than $v$ selects $k$ neighbours, independently and uniformly, and $u$ is
infected in this step if and only if at least one of the selected neighbours
has been infected in the previous step. We show the duality between COBRA and
BIPS which says that the time to infect the whole graph in the BIPS process is
of the same order as the cover time of the COBRA process


title: Numerical Study of the Sedimentation of Spheroidal Particles

abstract:
  The gravity-driven motion of rigid particles in a viscous fluid is relevant
in many natural and industrial processes, yet this has mainly been investigated
for spherical particles. We therefore consider the sedimentation of
non-spherical (spheroidal) isolated and particle pairs in a viscous fluid via
numerical simulations using the Immersed Boundary Method. The simulations
performed here show that the critical Galileo number for the onset of secondary
motions decreases as the spheroid aspect ratio departs from 1. Above this
critical threshold, oblate particles perform a zigzagging motion whereas
prolate particles rotate around the vertical axis while having their broad side
facing the falling direction. Instabilities of the vortices in the wake follow
when farther increasing the Galileo number. We also study the
drafting-kissing-tumbling associated with the settling of particle pairs. We
find that the interaction time increases significantly for non-spherical
particles and, more interestingly, spheroidal particles are attracted from
larger lateral displacements. This has important implications for the
estimation of collision kernels and can result in increasing clustering in
suspensions of sedimenting spheroids.


title: Dynamics of quantized vortices moving towards reconnection

abstract:
  The main goal of this paper is to investigate numerically the dynamics of
quantized vortex loops, just before the reconnection at finite temperature,
when mutual friction essentially changes evolution of lines. Modeling is
performed on the base of vortex filament method with using the full Biot-Savart
equation. It was discovered that initial position of vortices and the
temperature strongly affect the dependence on time of the minimum distance
$\delta (t)$ between tips of two vortex loops. In particular, in some cases the
shrinking and collapse of vortex loops due to mutual friction occur earlier
than reconnection, thereby cancelling the latter. However, this relationship
takes a universal square-root form
$\delta\left(t\right)=\sqrt{\left(\kappa/2\pi\right)\left(t_{*}-t\right)}$ at
distances smaller than the one, satisfying the Schwarz criterion, when nonlocal
contribution to the Biot-Savart equation becomes about equal to local
contribution. In the "universal" the nearest parts of vortices form a
pyramid-like structure with angles which are also don't depend both on the
initial configuration of filaments and on the temperature.


title:
Do electron-capture supernovae make neutron stars? First
  multidimensional hydrodynamic simulations of the oxygen deflagration

abstract:
  In the classical picture, electron-capture supernovae and the
accretion-induced collapse of oxygen-neon white dwarfs (ONeWDs) undergo an
oxygen deflagration phase before gravitational collapse produces a neutron star
(NS). These types of core collapse events are postulated to explain several
astronomical phenomena. In this work, the deflagration phase is simulated for
the first time using multidimensional hydrodynamics, with the aim of gaining
new insight into the explosive deaths of $8-10~M_\odot$ stars and ONeWDs that
accrete material from a binary companion star. The main aim is to determine
whether these events are thermonuclear or core-collapse supernova explosions,
and hence whether NSs are formed by such phenomena. The deflagration is
simulated in ONe cores with three different central ignition densities. The
intermediate density case is perhaps the most realistic, being based on recent
nuclear physics calculations and 1D stellar models. The 3D hydrodynamic
simulations presented in this work begin from a centrally confined flame
structure using a level-set-based flame approach and are performed in $256^3$
and $512^3$ numerical resolutions. In the simulations with intermediate and low
ignition density, the cores do not appear to collapse into NSs. Instead, almost
a solar mass of material becomes unbound from the cores, leaving bound
remnants. These simulations represent the case in which semiconvective mixing
during the electron-capture phase preceding the deflagration is inefficient.
The masses of the bound remnants double when Coulomb corrections are included
in the EoS, however they still do not exceed the effective Chandrasekhar mass
and, hence, would not collapse into NSs. The simulations with the highest
ignition density ($\log_{10}\rho_{\rm c}=10.3$), representing the case where
semiconvective mixing is very efficient, show clear signs that the core will
collapse into a NS.


title:
Corpus analysis without prior linguistic knowledge - unsupervised mining
  of phrases and subphrase structure

abstract:
  When looking at the structure of natural language, "phrases" and "words" are
central notions. We consider the problem of identifying such "meaningful
subparts" of language of any length and underlying composition principles in a
completely corpus-based and language-independent way without using any kind of
prior linguistic knowledge. Unsupervised methods for identifying "phrases",
mining subphrase structure and finding words in a fully automated way are
described. This can be considered as a step towards automatically computing a
"general dictionary and grammar of the corpus". We hope that in the long run
variants of our approach turn out to be useful for other kind of sequence data
as well, such as, e.g., speech, genom sequences, or music annotation. Even if
we are not primarily interested in immediate applications, results obtained for
a variety of languages show that our methods are interesting for many practical
tasks in text mining, terminology extraction and lexicography, search engine
technology, and related fields.


title:
From Fe$_3$O$_4$/NiO bilayers to NiFe$_2$O$_4$-like thin films through
  Ni interdiffusion

abstract:
  Ferrites with (inverse) spinel structure display a large variety of
electronic and magnetic properties making some of them interesting for
potential applications in spintronics. We investigate the thermally induced
interdiffusion of Ni$^{2+}$ ions out of NiO into Fe$_3$O$_4$ ultrathin films
resulting in off-stoichiometric nickelferrite-like thin layers. We synthesized
epitaxial Fe$_3$O$_4$/NiO bilayers on Nb-doped SrTiO$_3$(001) substrates by
means of reactive molecular beam epitaxy. Subsequently, we performed an
annealing cycle comprising three steps at temperatures of 400\,$^{\circ}$C,
600\,$^{\circ}$C, and 800\,$^{\circ}$C under an oxygen background atmosphere.
We studied the changes of the chemical and electronic properties as result of
each annealing step with help of hard x-ray photoelectron spectroscopy and
found a rather homogenous distribution of Ni and Fe cations throughout the
entire film after the overall annealing cycle. For one sample we observed a
cationic distribution close to that of the spinel ferrite NiFe$_2$O$_4$.
Further evidence comes from low energy electron diffraction patterns indicating
a spinel type structure at the surface after annealing. Site and element
specific hysteresis loops performed by x-ray magnetic circular dichroism
uncovered the antiferrimagnetic alignment between the octahedral coordinated
Ni$^{2+}$ and Fe$^{3+}$ ions and the Fe$^{3+}$ in tetrahedral coordination. We
find a quite low coercive field of 0.02\,T, indicating a rather low defect
concentration within the thin ferrite films.


title: Cooperative internal conversion process by proton exchange

abstract:
  A generalization of the recently discovered cooperative internal conversion
process is investigated theoretically. In the cooperative internal conversion
process by proton exchange investigated the coupling of bound-free electron and
proton transitions due to the dipole term of their Coulomb interaction permits
cooperation of two nuclei leading to proton exchange and an electron emission.
General expression of the cross section of the process obtained in the one
particle spherical nuclear shell model is presented. As a numerical example the
cooperative internal conversion process by proton exchange in $Al$ is dealt
with. As a further generalization, cooperative internal conversion process by
heavy charged particle exchange and as an example of it the cooperative
internal conversion process by triton exchange is discussed. The process is
also connected to the field of nuclear waste disposal.


title:
Locking of electron spin coherence over fifty milliseconds in natural
  silicon carbide

abstract:
  We demonstrate that silicon carbide (SiC) with natural isotope abundance can
preserve a coherent spin superposition in silicon vacancies over unexpectedly
long time approaching 0.1 seconds. The spin-locked subspace with drastically
reduced decoherence rate is attained through the suppression of heteronuclear
spin cross-talking by applying a moderate magnetic field in combination with
dynamic decoupling from the nuclear spin baths. We identify several
phonon-assisted mechanisms of spin-lattice relaxation, ultimately limiting
quantum coherence, and find that it can be extremely long at cryogenic
temperature, equal or even longer than 8 seconds. Our approach may be extended
to other polyatomic compounds and open a path towards improved qubit memory for
wafer-scale quantum techmologies.


title: A note on covers of fibred hyperbolic manifolds

abstract:
  For each surface $S$ of genus $g>2$ we construct pairs of conjugate
pseudo-Anosov maps, $\varphi_1$ and $\varphi_2$, and two non-equivalent covers
$p_i: \tilde S \longrightarrow S$, $i=1,2$, so that the lift of $\varphi_1$ to
$\tilde S$ with respect to $p_1$ coincides with that of $\varphi_2$ with
respect to $p_2$. The mapping tori of the $\varphi_i$ and their lift provide
examples of pairs of hyperbolic $3$-manifolds so that the first is covered by
the second in two different ways.


title: An all-sky Support Vector Machine selection of WISE YSO Candidates

abstract:
  We explored the AllWISE catalogue of the Wide-field Infrared Survey Explorer
mission and identified Young Stellar Object candidates. Reliable 2MASS and WISE
photometric data combined with Planck dust opacity values were used to build
our dataset and to find the best classification scheme. A sophisticated
statistical method, the Support Vector Machine (SVM) is used to analyse the
multi-dimensional data space and to remove source types identified as
contaminants (extragalactic sources, main sequence stars, evolved stars and
sources related to the interstellar medium). Objects listed in the SIMBAD
database are used to identify the already known sources and to train our
method. A new all-sky selection of 133,980 Class I/II YSO candidates is
presented. The estimated contamination was found to be well below 1% based on
comparison with our SIMBAD training set. We also compare our results to that of
existing methods and catalogues. The SVM selection process successfully
identified >90% of the Class I/II YSOs based on comparison with photometric and
spectroscopic YSO catalogues. Our conclusion is that by using the SVM, our
classification is able to identify more known YSOs of the training sample than
other methods based on colour-colour and magnitude-colour selection. The
distribution of the YSO candidates well correlates with that of the Planck
Galactic Cold Clumps in the Taurus--Auriga--Perseus--California region.


title:
Supersymmetrically bounding of asymmetric states and quantum phase
  transitions by anti-crossing of symmetric states

abstract:
  Von Neumann and Wigner theorized the bounding and anti-crossing of
eigenstates. Experiments have demonstrated that owing to anti-crossing and
similar radiation rates, the graphene-like resonance of inhomogeneously
strained photonic eigenstates can generate a pseudomagnetic field, bandgaps and
Landau levels, whereas exponential or dissimilar rates induce non-Hermicity.
Here, we experimentally demonstrate higher-order supersymmetry and quantum
phase transitions by resonance between similar one-dimensional lattices. The
lattices consisted of inhomogeneous strain-like phases of triangular solitons.
The resonance created two-dimensional, inhomogeneously deformed photonic
graphene. All parent eigenstates were annihilated. Eigenstates of mildly
strained solitons were annihilated at similar rates through one tail and
generated Hermitian bounded eigenstates. The strongly strained solitons with
positive phase defects were annihilated at exponential rates through one tail,
which bounded eigenstates through non-Hermitianally generated exceptional
points. However, strongly strained solitons with negative defects were
effectively amplified. Supersymmetry was evident, with preservation of the
shapes and relative phase differences of the parent solitons. Localizations of
energies generated from annihilations of mildly and strongly strained soliton
eigenstates were responsible for geometrical (Berry) and topological phase
transitions, respectively. Both contributed to generating a quantum Zeno phase,
whereas only strong twists generated topological (Anderson) localization.
Anti-bunching-like condensation was also observed.


title:
Low-noise amplification and frequency conversion with a multiport
  microwave optomechanical device

abstract:
  High-gain amplifiers of electromagnetic signals operating near the quantum
limit are crucial for quantum information systems and ultrasensitive quantum
measurements. However, the existing techniques have a limited gain-bandwidth
product and only operate with weak input signals. Here we demonstrate a
two-port optomechanical scheme for amplification and routing of microwave
signals, a system that simultaneously performs high-gain amplification and
frequency conversion in the quantum regime. Our amplifier, implemented in a
two-cavity microwave optomechanical device, shows 41 dB of gain and has a high
dynamic range, handling input signals up to $10^{13}$ photons per second, three
orders of magnitude more than corresponding Josephson parametric amplifiers. We
show that although the active medium, the mechanical resonator, is at a high
temperature far from the quantum limit, only 4.6 quanta of noise is added to
the input signal. Our method can be readily applied to a wide variety of
optomechanical systems, including hybrid optical-microwave systems, creating a
universal hub for signals at the quantum level.


title: Optimal error intervals for properties of the quantum state

abstract:
  Quantum state estimation aims at determining the quantum state from observed
data. Estimating the full state can require considerable efforts, but one is
often only interested in a few properties of the state, such as the fidelity
with a target state, or the degree of correlation for a specified bipartite
structure. Rather than first estimating the state, one can, and should,
estimate those quantities of interest directly from the data. We propose the
use of optimal error intervals as a meaningful way of stating the accuracy of
the estimated property values. Optimal error intervals are analogs of the
optimal error regions for state estimation [New J. Phys. 15, 123026 (2013)].
They are optimal in two ways: They have the largest likelihood for the observed
data and the pre-chosen size, and are the smallest for the pre-chosen
probability of containing the true value. As in the state situation, such
optimal error intervals admit a simple description in terms of the marginal
likelihood for the data for the properties of interest. Here, we present the
concept and construction of optimal error intervals, report on an iterative
algorithm for reliable computation of the marginal likelihood (a quantity
difficult to calculate reliably), explain how plausible intervals --- a notion
of evidence provided by the data --- are related to our optimal error
intervals, and illustrate our methods with single-qubit and two-qubit examples.


title: Virtual Element Methods for hyperbolic problems on polygonal meshes

abstract:
  In the present paper we develop the Virtual Element Method for hyperbolic
problems on polygonal meshes, considering the linear wave equations as our
model problem. After presenting the semi-discrete scheme, we derive the
convergence estimates in H^1 semi-norm and L^2 norm. Moreover we develop a
theoretical analysis on the stability for the fully discrete problem by
comparing the Newmark method and the Bathe method. Finally we show the
practical behaviour of the proposed method through a large array of numerical
tests.


title:
The coevolution of overconfidence and bluffing in the resource
  competition game

abstract:
  Resources are often limited, therefore it is essential how convincingly
competitors present their claims for them. Beside a player's natural capacity,
here overconfidence and bluffing may also play a decisive role and influence
how to share a restricted reward. While bluff provides clear, but risky
advantage, overconfidence, as a form of self-deception, could be harmful to its
user. Still, it is a long-standing puzzle why these potentially damaging biases
are maintained and evolving to a high level in the human society. Within the
framework of evolutionary game theory, we present a simple version of resource
competition game in which the coevolution of overconfidence and bluffing is
fundamental, which is capable to explain their prevalence in structured
populations. Interestingly, bluffing seems apt to evolve to higher level than
corresponding overconfidence and in general the former is less resistant to
punishment than the latter. Moreover, topological feature of the social network
plays an intricate role in the spreading of overconfidence and bluffing. While
the heterogeneity of interactions facilitates bluffing, it also increases
efficiency of adequate punishment against overconfident behavior. Furthermore,
increasing the degree of homogeneous networks can trigger similar effect. We
also observed that having high real capability may accommodate both bluffing
ability and overconfidence simultaneously.


title:
The GREGOR Fabry Perot Interferometer (GFPI), Technical Innovations and
  Results achieved in 2013

abstract:
  This paper shall provide a summary of not yet published technical innovations
to the GREGOR Fabry-Perot Interferometer (GFPI) at the 1.5m GREGOR Solar
Telescope (Europe's largest solar telescope) that I implemented in 2013 as the
Instrument Scientist of the GFPI. It also represents an overview of important
and not yet published observational results that I achieved with the GFPI in
2013. The results and achievements can be considered a milestone in the further
development, scientific verification and final acceptance of this instrument.
The instrument is now in operation and employed by the international scientific
community.


title: On Subtilings of Polyomino Tilings

abstract:
  We consider a problem concerning tilings of rectangular regions by a finite
library of polyominoes. We specifically look at rectangular regions of
dimension $n\times m$ and ask whether or not a tiling of this region can be
rearranged so that tiling of the $n\times m$ rectangle can be realized as a
tiling of an $n\times m'$ rectangle and an $n\times m"$ rectangle, $m=m'+m"$.
We call this a subtiling. We show that the associated decision problem is
$\mathsf{NP}$-complete when restricted to rectangular polyominoes. We also show
that for certain finite libraries of polyominoes, if $m$ is sufficiently large,
a subtiling always exists and give bounds.


title:
Far-infrared photometric observations of the outer planets and
  satellites with Herschel-PACS

abstract:
  We present all Herschel PACS photometer observations of Mars, Saturn, Uranus,
Neptune, Callisto, Ganymede, and Titan. All measurements were carefully
inspected for quality problems, were reduced in a (semi-)standard way, and were
calibrated. The derived flux densities are tied to the standard PACS photometer
response calibration, which is based on repeated measurements of five fiducial
stars. The overall absolute flux uncertainty is dominated by the estimated 5%
model uncertainty of the stellar models in the PACS wavelength range between 60
and 210 micron. A comparison with the corresponding planet and satellite models
shows excellent agreement for Uranus, Neptune, and Titan, well within the
specified 5%. Callisto is brighter than our model predictions by about 4-8%,
Ganymede by about 14-21%. We discuss possible reasons for the model offsets.
The measurements of these very bright point-like sources, together with
observations of stars and asteroids, show the high reliability of the PACS
photometer observations and the linear behavior of the PACS bolometer source
fluxes over more than four orders of magnitude (from mJy levels up to more than
1000 Jy). Our results show the great potential of using the observed solar
system targets for cross-calibration purposes with other ground-based,
airborne, and space-based instruments and projects. At the same time, the PACS
results will lead to improved model solutions for future calibration
applications.


title:
A Reconfigurable Cryogenic Platform for the Classical Control of
  Scalable Quantum Computers

abstract:
  Recent advances in solid-state qubit technology are paving the way to
fault-tolerant quantum computing systems. However, qubit technology is limited
by qubit coherence time and by the complexity of coupling the quantum system
with a classical electronic infrastructure.
  We propose an infrastructure, enabling to read and control qubits, that is
implemented on a field-programmable gate array (FPGA). The FPGA platform
supports functionality required by several qubit technologies and can operate
physically close to the qubits over a temperature range from 4K to 300K.
Extensive characterization of the platform over this temperature range revealed
all major components (such as LUTs, MMCM, PLL, BRAM, IDELAY2) operate correctly
and the logic speed is very stable. The stability is finally concretized by
operating an integrated ADC with relatively stable performance over
temperature.


title:
Non-contractible Hamiltonian loops in the kernel of Seidel's
  representation

abstract:
  The main purpose of this note is to exhibit a Hamiltonian diffeomorphism loop
undetected by the Seidel morphism of certain 2-point blow-ups of $S^2 \times
S^2$, exactly one of which being monotone. As side remarks, we show that
Seidel's morphism is injective on all Hirzebruch surfaces and discuss how to
adapt the monotone example to the Lagrangian setting.


title: Deformed phase spaces with group valued momenta

abstract:
  We introduce a general framework for describing deformed phase spaces with
group valued momenta. Using techniques from the theory of Poisson-Lie groups
and Lie bi-algebras we develop tools for constructing Poisson structures on the
deformed phase space starting from the minimal input of the algebraic structure
of the generators of the momentum Lie group. The tools developed are used to
derive Poisson structures on examples of group momentum space much studied in
the literature such as the $n$-dimensional generalization of the
$\kappa$-deformed momentum space and the $SL(2, \mathbb{R})$ momentum space in
three space-time dimensions. We discuss classical momentum observables
associated to multi-particle systems and argue that these combine according the
usual four-vector addition despite the non-abelian group structure of momentum
space.


title: Forming isolated brown dwarfs by turbulent fragmentation

abstract:
  We use Smoothed Particle Hydrodynamics to explore the circumstances under
which an isolated very-low-mass prestellar core can be formed by colliding
turbulent flows and collapse to form a brown-dwarf. Our simulations suggest
that the flows need not be very fast, but do need to be very strongly
convergent, i.e. the gas must flow in at comparable speeds from all sides,
which seems rather unlikely. We therefore revisit the object Oph-B11, which
Andre, Ward-Thompson and Greaves (2012) have identified as a prestellar core
with mass between $\sim 0.020\,\mathrm{M_\odot}$ and $\sim
0.030\,\mathrm{M_\odot}$. We reanalyse the observations using a Markov-chain
Monte Carlo method that allows us (i) to include the uncertainties on the
distance, temperature and dust mass opacity, and (ii) to consider different
Bayesian prior distributions of the mass. We estimate that the posterior
probability that Oph-B11 has a mass below the hydrogen burning limit at $\sim
0.075\,\mathrm{M_\odot}$, is between 0.66 and 0.86. We conclude that, if
Oph-B11 is destined to collapse, it probably will form a brown dwarf. However,
the flows required to trigger this appear to be so contrived that it is
difficult to envisage this being the only way, or even a major way, of forming
isolated brown dwarfs. Moreover, Oph-B11 could easily be a transient, bouncing,
prolate core, seen end-on; there could, indeed should, be many such objects
masquerading as very low-mass prestellar cores.


title:
Superconducting proximity effect in epitaxial Nb(110)/Au(111)/Nb(110)
  trilayers

abstract:
  Single-domain, epitaxially-grown Nb(110)/Au(111)/Nb(110) trilayers are
studied in order to elucidate the superconducting proximity effect in the
Au(111) layer. The critical current density, superconducting coherence length,
and superconducting transition temperature, all show a non-monotonic dependence
on the thickness of the Au layer. The analysis of the experimental data
reasonably argues that a form of order-parameter oscillation is intrinsic to
the proximity-induced Cooper pairs in the Au layer. We find that relative phase
of the superconducting order parameter in the two Nb(110) layers changes sign
as a function of Au(111) layer thickness tAu, offering a route to achieving a
{\pi} junction for 0.94 nm<tAu<1.88 nm.


title:
The multiconfigurational time-dependent Hartree method for bosons with
  internal degrees of freedom: Theory and composite fragmentation of
  multi-component Bose-Einstein condensates

abstract:
  In this paper the multiconfigurational time-dependent Hartree for bosons
method (MCTDHB) is derived for the case of $N$ identical bosons with internal
degrees of freedom. The theory for bosons with internal degrees of freedom
constitutes a generalization of the MCTDHB method that substantially enriches
the many-body physics that can be described. We demonstrate that the
numerically exact solution of the time-dependent many-body Schr\"odinger
equation for interacting bosonic particles with internal degrees of freedom is
now feasible. We report on the MCTDHB equations of motion for bosons with
internal degrees of freedom and their implementation for a general many-body
Hamiltonian with one-body and two-body terms that, both, may depend on the
internal states of the considered particles. To demonstrate the capabilities of
the theory and its software implementation integrated in the MCTDH-X software,
we apply MCTDHB to the emergence of fragmentation of parabolically trapped
bosons with two internal states: we study the groundstate of $N=100$
parabolically confined bosons as a function of the splitting between the
state-dependent minima of the two parabolic potentials. To quantify the
coherence of the system we compute its normalized one-body correlation
function. We find that the coherence within each internal state of the atoms is
maintained, while it is lost between the different internal states. This is a
hallmark of a new kind of fragmentation which is absent in bosons without
internal structure. We term the emergent phenomenon "composite fragmentation".


title: Graded codimensions of Lie superalgebra $b(2)$

abstract:
  We study asymptotic behaviour of graded codimensions of Lie superalgebra
$b(2)$. We prove that graded PI-exponent exists and is equal to $3+2\sqrt 3$.


title:
A stochastic approach to path-dependent nonlinear Kolmogorov equations
  via BSDEs with time-delayed generators and applications to finance

abstract:
  We prove the existence of a viscosity solution of the following path
dependent nonlinear Kolmogorov equation: \[ \begin{cases}
\partial_{t}u(t,\phi)+\mathcal{L}u(t,\phi)+f(t,\phi,u(t,\phi),\partial_{x}u(t,\phi)
\sigma(t,\phi),(u(\cdot,\phi))_{t})=0,\;t\in[0,T),\;\phi\in\mathbb{\Lambda}\,
,u(T,\phi)=h(\phi),\;\phi\in\mathbb{\Lambda}, \end{cases} \] where
$\mathbb{\Lambda}=\mathcal{C}([0,T];\mathbb{R}^{d})$, $(u(\cdot
,\phi))_{t}:=(u(t+\theta,\phi))_{\theta\in[-\delta,0]}$ and \[
\mathcal{L}u(t,\phi):=\langle b(t,\phi),\partial_{x}u(t,\phi)\rangle+\dfrac
{1}{2}\mathrm{Tr}\big[\sigma(t,\phi)\sigma^{\ast}(t,\phi)\partial_{xx}
^{2}u(t,\phi)\big]. \] The result is obtained by a stochastic approach. In
particular we prove a new type of nonlinear Feynman-Kac representation formula
associated to a backward stochastic differential equation with time-delayed
generator which is of non-Markovian type.
  Applications to the large investor problem and risk measures via
$g$-expectations are also provided.


title: Conformal Bootstrap in Embedding Space

abstract:
  It is shown how to obtain conformal blocks from embedding space with the help
of the operator product expansion. The minimal conformal block originates from
scalar exchange in a four-point correlation functions of four scalars. All
remaining conformal blocks are simple derivatives of the minimal conformal
block. With the help of the orthogonality properties of the conformal blocks,
the analytic conformal bootstrap can be implemented directly in embedding
space, leading to a Jacobi-like definition of conformal field theories.


title:
Examination and visualisation of the simplifying assumption for vine
  copulas in three dimensions

abstract:
  Vine copulas are a highly flexible class of dependence models, which are
based on the decomposition of the density into bivariate building blocks. For
applications one usually makes the simplifying assumption that copulas of
conditional distributions are independent of the variables on which they are
conditioned. However this assumption has been criticised for being too
restrictive. We examine both simplified and non-simplified vine copulas in
three dimensions and investigate conceptual differences. We show and compare
contour surfaces of three-dimensional vine copula models, which prove to be
much more informative than the contour lines of the bivariate marginals. Our
investigation shows that non-simplified vine copulas can exhibit arbitrarily
irregular shapes, whereas simplified vine copulas appear to be smooth
extrapolations of their bivariate margins to three dimensions. In addition to a
variety of constructed examples, we also investigate a three-dimensional subset
of the well-known uranium data set and visually detect that a non-simplified
vine copula is necessary to capture its complex dependence structure.


title: Graded identities of some simple Lie superalgebras

abstract:
  We study $\mathbb{Z}_2$-graded identities of Lie superalgebras of the type
$b(t), t\ge 2$, over a field of characteristic zero. Our main result is that
the $n$-th codimension is strictly less than $(\dim b(t))^n$ asymptotically. As
a consequence we obtain an upper bound for ordinary (non-graded) PI-exponent
for each simple Lie superalgebra $b(t), t\ge 3$.


title:
Gapped triplet $p$-wave superconductivity in strong spin-orbit-coupled
  semiconductor quantum wells in proximity to $s$-wave superconductor

abstract:
  We show that the {\it gapped} triplet superconductivity, i.e., a triplet
superconductor with triplet order parameter, can be realized in strong
spin-orbit-coupled quantum wells in proximity to $s$-wave superconductor. It is
revealed that with the singlet order parameter induced from the superconducting
proximity effect, in quantum wells, not only can the triplet pairings arise due
to the spin-orbit coupling, but also the triplet order parameter can be induced
due to the repulsive effective electron-electron interaction, including the
electron-electron Coulomb and electron-phonon interactions. This is a natural
extension of the work of de Gennes, in which the repulsive-interaction-induced
singlet order parameter arises in the normal metal in proximity to $s$-wave
superconductor [Rev. Mod. Phys. {\bf 36}, 225 (1964)]. Specifically, we derive
the effective Bogoliubov-de Gennes equation, in which the self-energies due to
the effective electron-electron interactions contribute to the singlet and
triplet order parameters. It is further shown that for the singlet order
parameter, it is efficiently suppressed due to this self-energy
renormalization; whereas for the triplet order parameter, it is the $p$-wave
($p_x\pm ip_y$) one with the ${\bf d}$-vector parallel to the effective
magnetic field due to the spin-orbit coupling. Finally, we perform the
numerical calculation in InSb (100) quantum wells. Specifically, we reveal that
the Coulomb interaction is much more important than the electron-phonon
interaction at low temperature. Moreover, it shows that with proper electron
density, the minimum of the renormalized singlet and the maximum of the induced
triplet order parameters are comparable, and hence can be experimentally
distinguished.


title: Betweenness and Nonbetweenness

abstract:
  The betweenness function $bet(n)$ is the minimum number of total orderings of
$n$ objects such that for any three distinct objects $a$, $b$ and $c$, there is
an ordering in which $b$ is between $a$ and $c$. The nonbetweenness function
$nbet(n)$ is the minimum number of total orderings such that for any three
distinct objects $a$, $b$ and $c$, there is an ordering in which $b$ is not
between $a$ and $c$. We show that $nbet(n) = \left\lceil \log_2\log_2n
\right\rceil+1$ and $bet(n) = \Theta(\log n)$. Betweenness and Nonbetweenness
are specific cases of a more general extreme value function called the `extreme
ternary constraint function'. The asymptotic value of this generalisation is
computed using the values of $nbet(n)$ and $bet(n)$. This result demonstrates
that the minimum size of a set of rooted phylogenetic trees is consistent with
all phylogenetic triplets is $\Theta(\log\log n)$.


title: Group gradings on finite dimensional Lie algebras

abstract:
  We study gradings by noncommutative groups on finite dimensional Lie algebras
over an algebraically closed field of characteristic zero. It is shown that if
$L$ is gradeg by a non-abelian finite group $G$ then the solvable radical $R$
of $L$ is $G$-graded and there exists a Levi subalgebra
$B=H_1\oplus\cdots\oplus H_m$ homogeneous in $G$-grading with graded simple
summands $H_1, \ldots, H_m$. All supports $Supp~H_i, i=1\ldots, m$, are
commutative subsets of $G$.


title:
Holomorphic correspondences related to finitely generated rational
  semigroups

abstract:
  In this paper, we present a new technique for studying the dynamics of a
finitely generated rational semigroup. Such a semigroup can be associated
naturally to a certain holomorphic correspondence on $\mathbb{P}^1$. Then,
results on the iterative dynamics of such a correspondence can be applied to
the study of the rational semigroup. We focus on a certain invariant measure
for the aforementioned correspondence---known as the equilibrium measure. This
confers some advantages over many of the known techniques for studying the
dynamics of rational semigroups. We use the equilibrium measure to analyse the
distribution of repelling fixed points of a finitely generated rational
semigroup, and to derive a sharp bound for the Hausdorff dimension of the Julia
set of such a semigroup.


title:
Leave-one-out prediction intervals in linear regression models with many
  variables

abstract:
  We study prediction intervals based on leave-one-out residuals in a linear
regression model where the number of explanatory variables can be large
compared to sample size. We establish uniform asymptotic validity (conditional
on the training sample) of the proposed interval under minimal assumptions on
the unknown error distribution and the high dimensional design. Our intervals
are generic in the sense that they are valid for a large class of linear
predictors used to obtain a point forecast, such as robust M-estimators,
James-Stein type estimators and penalized estimators like the LASSO. These
results show that despite the serious problems of resampling procedures for
inference on the unknown parameters, leave-one-out methods can be successfully
applied to obtain reliable predictive inference even in high dimensions.


title:
Correlations induced orbital ordering and cooperative Jahn-Teller
  distortion in the paramagnetic insulator KCrF$_3$

abstract:
  We investigate the origin of the orbital ordering in the paramagnetic phase
of KCrF$_3$. All previous studies described structural parameters of the
paramagnetic phase using a magnetic ordering in the compound. Our simulations
of real paramagnetic KCrF$_3$ were performed within an approach combining
density functional theory and dynamical mean field theory (DFT+DMFT). As a
result, it was found that the experimentally observed cooperative Jahn-Teller
effect is successfully described in a lattice relaxation calculation for
structure without any long-range magnetic ordering. It is established that the
existence of the orbital ordering even in undistorted perovskite structure
clearly confirms the electronic origin of the orbital ordering in KCrF$_3$.


title:
An Efficient and Accurate Two-Stage Fourth-order Gas-kinetic Scheme for
  the Navier-Stokes Equations

abstract:
  For computational fluid dynamics (CFD), the generalized Riemann problem (GRP)
solver and the gas-kinetic kinetic scheme (GKS) provide a time-accurate flux
function starting from a discontinuous piecewise linear flow distributions
around each cell interface. With the use of time derivative of the flux
function, a two-stage Lax-Wendroff-type (L-W for short) time stepping method
has been recently proposed in the design of a fourth-order time accurate method
[18]. In this paper, based on the same time-stepping method and the
second-order GKS flux function [34], a fourth-order gas-kinetic scheme is
constructed for the Euler and Navier-Stokes equations. In comparison with the
formal one-stage time-stepping third-order gas-kinetic solver [21], the current
fourth-order method not only reduces the complexity of the flux function, but
also improves the accuracy of the scheme, even though the third- and
fourth-order schemes have similar computation cost. Most importantly, the
robustness of the fourth-order GKS is as good as the second-order one. Perfect
numerical solutions can be obtained from the high Reynolds number boundary
layer solutions to the hypersonic viscous heat conducting flow computations.
Many numerical tests, including many difficult ones for the Navier-Stokes
solvers, have been used to validate the current fourth-order method. Following
the two-stage time-stepping framework, the one-stage third-order GKS can be
easily extended to a fifth-order method with the usage of both first-order and
second-order time derivatives of the flux function. The use of time-accurate
flux function may have great impact on the development of higher-order CFD
methods.


title:
Electronic and magnetic structure of epitaxial NiO/Fe$_3$O$_4$(001)
  heterostructures grown on MgO(001) and Nb-doped SrTiO$_3$(001)

abstract:
  We study the underlying chemical, electronic and magnetic properties of a
number of magnetite based thin films. The main focus is placed onto
NiO/Fe$_3$O$_4$(001) bilayers grown on MgO(001) and Nb-SrTiO$_3$(001)
substrates. We compare the results with those obtained on pure Fe$_3$O$_4$(001)
thin films. It is found that the magnetite layers are oxidized and Fe$^{3+}$
dominates at the surfaces due to maghemite ($\gamma$-Fe$_2$O$_3$) formation,
which decreases with increasing magnetite layer thickness. From a layer
thickness of around 20 nm on the cationic distribution is close to that of
stoichiometric Fe$_3$O$_4$. At the interface between NiO and Fe$_3$O$_4$ we
find the Ni to be in a divalent valence state, with unambiguous spectral
features in the Ni 2p core level x-ray photoelectron spectra typical for NiO.
The formation of a significant NiFe$_2$O$_4$ interlayer can be excluded by
means of XMCD. Magneto optical Kerr effect measurements reveal significant
higher coercive fields compared to magnetite thin films grown on MgO(001), and
a 45$^{\circ}$ rotated magnetic easy axis. We discuss the spin magnetic moments
of the magnetite layers and find that the moment increases with increasing thin
film thickness. At low thickness the NiO/Fe$_3$O$_4$ films grown on
Nb-SrTiO$_3$ exhibits a significantly decreased spin magnetic moments. A
thickness of 20 nm or above leads to spin magnetic moments close to that of
bulk magnetite.


title:
Spectral properties of weighted composition operators on the Bloch and
  Dirichlet spaces

abstract:
  The spectra of invertible weighted composition operators $uC_\varphi$ on the
Bloch and Dirichlet spaces are studied. In the Bloch case we obtain a complete
description of the spectrum when $\varphi$ is a parabolic or elliptic
automorphism of the unit disc. In the case of a hyperbolic automorphism
$\varphi$, exact expressions for the spectral radii of invertible weighted
composition operators acting on the Bloch and Dirichlet spaces are derived.


title:
Spectral semi-implicit and space-time discontinuous Galerkin methods for
  the incompressible Navier-Stokes equations on staggered Cartesian grids

abstract:
  In this paper two new families of arbitrary high order accurate spectral DG
finite element methods are derived on staggered Cartesian grids for the
solution of the inc.NS equations in two and three space dimensions. Pressure
and velocity are expressed in the form of piecewise polynomials along different
meshes. While the pressure is defined on the control volumes of the main grid,
the velocity components are defined on a spatially staggered mesh. In the first
family, h.o. of accuracy is achieved only in space, while a simple
semi-implicit time discretization is derived for the pressure gradient in the
momentum equation. The resulting linear system for the pressure is symmetric
and positive definite and either block 5-diagonal (2D) or block 7-diagonal (3D)
and can be solved very efficiently by means of a classical matrix-free
conjugate gradient method. The use of a preconditioner was not necessary. This
is a rather unique feature among existing implicit DG schemes for the NS
equations. In order to avoid a stability restriction due to the viscous terms,
the latter are discretized implicitly. The second family of staggered DG
schemes achieves h.o. of accuracy also in time by expressing the numerical
solution in terms of piecewise space-time polynomials. In order to circumvent
the low order of accuracy of the adopted fractional stepping, a simple
iterative Picard procedure is introduced. In this manner, the symmetry and
positive definiteness of the pressure system are not compromised. The resulting
algorithm is stable, computationally very efficient, and at the same time
arbitrary h.o. accurate in both space and time. The new numerical method has
been thoroughly validated for approximation polynomials of degree up to N=11,
using a large set of non-trivial test problems in two and three space
dimensions, for which either analytical, numerical or experimental reference
solutions exist.


title:
On distributions with fixed marginals maximizing the joint or the prior
  default probability, estimation, and related results

abstract:
  We study the problem of maximizing the probability that (i) an electric
component or financial institution $X$ does not default before another
component or institution $Y$ and (ii) that $X$ and $Y$ default jointly within
the class of all random variables $X,Y$ with given univariate continuous
distribution functions $F$ and $G$, respectively, and show that the
maximization problems correspond to finding copulas maximizing the mass of the
endograph $\Gamma^\leq(T)$ and the graph $\Gamma(T)$ of $T=G \circ F^-$,
respectively. After providing simple, copula-based proofs for the existence of
copulas attaining the two maxima $\overline{m}_T$ and $\overline{w}_T$ we
generalize the obtained results to the case of general (not necessarily
monotonic) transformations $T:[0,1] \rightarrow [0,1]$ and derive simple and
easily calculable formulas for $\overline{m}_T$ and $\overline{w}_T$ involving
the distribution function $F_T$ of $T$ (interpreted as random variable on
$[0,1]$). The latter are then used to charac\-terize all non-decreasing
transformations $T:[0,1] \rightarrow [0,1]$ for which $\overline{m}_T$ and
$\overline{w}_T$ coincide. A strongly consistent estimator for the maximum
probability that $X$ does not default before $Y$ is derived and proven to be
asymptotically normal under very mild regularity conditions. Several examples
and graphics illustrate the main results and falsify some seemingly natural
conjectures.


title: On the relaxation to nonequilibrium steady states

abstract:
  The issue of relaxation has been addressed in terms of ergodic theory in the
past. However, the application of that theory to models of physical interest is
problematic, especially when dealing with relaxation to nonequilibrium steady
states. Here, we consider the relaxation of classical, thermostatted particle
systems to equilibrium as well as to nonequilibrium steady states, using
dynamical notions including decay of correlations. We show that the condition
known as {\Omega}T-mixing is necessary and sufficient to prove relaxation of
ensemble averages to steady state values. We then observe that the condition
known as weak T-mixing applied to smooth observables is sufficient for
relaxation to be independent of the initial ensemble. Lastly, weak T-mixing for
integrable functions makes relaxation independent of the ensemble member, apart
from a negligible set of members enabling the result to be applied to
observations from a single physical experiment. The results also allow us to
give a microscopic derivation of Prigogine's principle of minimum entropy
production in the linear response regime. The key to deriving these results
lies in shifting the discussion from characteristics of dynamical systems, such
as those related to metric transitivity, to physical measurements and to the
behaviour of observables. This naturally leads to the notion of physical
ergodicity.


title:
Controllability of stochastic impulsive neutral functional differential
  equations driven by fractional Brownian motion with infinite delay

abstract:
  In this paper we study the controllability results of impulsive neutral
stochastic functional differential equations with infinite delay driven by
fractional Brownian motion in a real separable Hilbert space. The
controllability results are obtained using stochastic analysis and a
fixed-point strategy. Finally, an illustrative example is provided to
demonstrate the effectiveness of the theoretical result.


title: A low maintenance Sr optical lattice clock

abstract:
  We describe the Sr optical lattice clock apparatus at NPL with particular
emphasis on techniques used to increase reliability and minimise the human
requirement in its operation. Central to this is a clock-referenced transfer
cavity scheme for the stabilisation of cooling and trapping lasers. We
highlight several measures to increase the reliability of the clock with a view
towards the realisation of an optical time-scale. The clock contributed 502
hours of data over a 25 day period (84% uptime) in a recent measurement
campaign with several uninterrupted periods of more than 48 hours. An
instability of $2\times10^{-17}$ was reached after $10^5$ s of averaging in an
interleaved self-comparison of the clock.


title:
Confronting fluctuations of conserved charges in central nuclear
  collisions at the LHC with predictions from Lattice QCD

abstract:
  We construct net baryon number and strangeness susceptibilities as well as
correlations between electric charge, strangeness and baryon number from
experimental data on the particle production yields at midrapidity of the ALICE
Collaboration at CERN. The data were taken in central Pb-Pb collisions at
$\sqrt{s_{\rm NN}}$~=~2.76~TeV and cover one unit of rapidity. We show that the
resulting fluctuations and correlations are consistent with Lattice QCD results
at the chiral crossover pseudocritical temperature $T_{c} \simeq$ 155 MeV. This
agreement lends strong support to the assumption that the fireball created in
these collisions is of thermal origin and exhibits characteristic properties
expected in QCD at the transition from the quark gluon plasma to the hadronic
phase. Since Lattice QCD calculations are performed at a baryochemical
potential of $\mu_{B}$ = 0, the comparisons with LHC data are the most direct
due to the vanishing baryon transport to midrapidity at these high energies.


title: Particlelike wave packets in complex scattering systems

abstract:
  A wave packet undergoes a strong spatial and temporal dispersion while
propagating through a complex medium. This wave scattering is often seen as a
nightmare in wave physics whether it be for focusing, imaging or communication
purposes. Controlling wave propagation through complex systems is thus of
fundamental interest in many areas, ranging from optics or acoustics to medical
imaging or telecommunications. Here, we study the propagation of elastic waves
in a cavity and a disordered waveguide by means of laser interferometry. From
the direct experimental access to the time-delay matrix of these systems, we
demonstrate the existence of particle-like wave packets that remain focused in
time and space throughout their complex trajectory. Due to their limited
dispersion, their selective excitation will be crucially relevant for all
applications involving selective wave focusing and efficient information
transfer through complex media.


title:
Uniting Superhydrophobic, Superoleophobic and Lubricating Fluid Infused
  Slippery Behavior on Copper Oxide Nano-structured Substrates

abstract:
  Copper oxide nanostructures with spherical (0D), needle (1D) and hierarchical
cauliflower (3D) morphologies are used to demonstrate superhydrophobic,
superoleophobic and slippery behavior. These nanostructures are synthesized on
galvanized steel substrates using a simple chemical bath deposition method by
tuning precursor concentration. Subsequent coating of low surface energy
polymer, polydimethylsiloxane, results in superhydrophobicity with water
contact angle ~160(2){\deg} and critical sliding angle ~2{\deg}. When
functionalized with low-surface energy perfluoroalkyl silane, these surfaces
display high repellency for low surface tension oils and hydrocarbons. Among
them, the hierarchical cauliflower morphology exhibits better re-entrant
structure thus show the best superoleophobicity with 149{\deg} contact angle
for dodecane having surface tension 25.3 mNm-1. If these nanostructured
substrates are infused with lubricant Silicone oil, they show excellent
slippery behavior for water drops. Due to the lubricating nature of Silicone
oil, the Silicone oil infused slippery surfaces (SOIS) show low contact angle
hysteresis (~2{\deg}) and critical tilt angle (~2{\deg}). The hierarchical
cauliflower nanostrcuture exhibit better slippery characteristics and stability
compared to the other nanostructured surfaces.


title: Double parton scattering and 3D proton structure: A Light-Front analysis

abstract:
  Double parton scattering, occurring in high energy hadron-hadron collisions,
e.g. at the LHC, is usually investigated through model dependent analyses of
the so called effective cross section $\sigma_{eff}$. We present a dynamic
approach to this fundamental quantity making use of a Light-Front model
treatment. Within such a framework $\sigma_{eff}$ is initially evaluated at low
energy scale using the model and then, through QCD evolution, at high energy
scale to reach the experimental conditions. Our numerical outcomes are
consistent with the present experimental analyses of data in kinematical region
we investigate. An important result of the present work is the $x_i$ dependence
of $\sigma_{eff}$, a feature directly connected to double parton correlations
and which could unveil new information on the three dimensional structure of
the proton.


title:
Second order anisotropy contribution in perpendicular magnetic tunnel
  junctions

abstract:
  Magnetoresistance loops under in-plane applied field were measured on
perpendicularly magnetized magnetic tunnel junction (pMTJ) pillars with nominal
diameters ranging from 50 to 150 nm. By fitting the hard-axis magnetoresistance
loops to an analytical model, the effective anisotropy fields in both free and
reference layers were derived and their variations in temperature range between
340K and 5K were determined. It is found that an accurate fitting is possible
only if a second-order anisotropy term of the form $-K_{2}cos^4{\theta}$, is
added to the fitting model. This higher order contribution exists both in the
free and reference layers and its sign is opposite to that of the first order
anisotropy constant, $K_{1}$. At room temperatures the estimated $-K_{2}/K_{1}$
ratios are 0.1 and 0.24 for the free and reference layers, respectively. The
ratio is more than doubled at low temperatures altering the ground state of the
reference layer from 'easy-axis' to 'easy-cone' regime. Easy-cone state has
clear signatures in the shape of the hard-axis magnetoresistance loops. The
same behavior was observed in all measured devices regardless of their
diameter. The existence of this higher order anisotropy was confirmed
experimentally on FeCoB/MgO sheet films by ferromagnetic resonance technique.
It is of interfacial nature and is believed to be linked to spatial
fluctuations at the nanoscale of the anisotropy parameter at the FeCoB/MgO
interface, in agreement with Dieny-Vedyayev model.


title:
A low-luminosity soft state in the short period black hole X-ray binary
  Swift J1753.5-0127

abstract:
  We present results from the spectral fitting of the candidate black hole
X-ray binary Swift J1753.5-0127 in an accretion state previously unseen in this
source. We fit the 0.7-78 keV spectrum with a number of models, however the
preferred model is one of a multi-temperature disk with an inner disk
temperature $\mathrm{k}T_\mathrm{in}=0.252\pm0.003$ keV scattered into a steep
power-law with photon index $\Gamma=6.39^{+0.08}_{-0.02}$ and an additional
hard power law tail ($\Gamma=1.79\pm0.02$). We report on the emergence of a
strong disk-dominated component in the X-ray spectrum and we conclude that the
source has entered the soft state for the first time in its ~10 year prolonged
outburst. Using reasonable estimates for the distance to the source ($3$ kpc)
and black hole mass ($5M_{\odot}$), we find the unabsorbed luminosity (0.1-100
keV) to be $\approx0.60$% of the Eddington luminosity, making this one of the
lowest luminosity soft states recorded in X-ray binaries. We also find that the
accretion disk extended towards the compact object during its transition from
hard to soft, with the inner radius estimated to be
$R_{\mathrm{in}}=28.0^{+0.7}_{-0.4} R_g$ or ~$12R_g$, dependent on the boundary
condition chosen, assuming the above distance and mass, a spectral hardening
factor $f=1.7$ and a binary inclination $i=55^{\circ}$.


title: On a CFT limit of planar $\gamma_i$-deformed $\mathcal{N}=4$ SYM theory

abstract:
  We show that an integrable four-dimensional non-unitary field theory that was
recently proposed as a certain limit of the $\gamma_i$-deformed $\mathcal{N}=4$
SYM theory is incomplete and not conformal -- not even in the planar limit. We
complete this theory by double-trace couplings and find conformal one-loop
fix-points when admitting respective complex coupling constants. These
couplings must not be neglected in the planar limit, as they can contribute to
planar multi-point functions. Based on our results for certain two-loop planar
anomalous dimensions, we propose tests of integrability.


title:
Spin Liquid State in the 3D Frustrated Antiferromagnet PbCuTe2O6: NMR
  and muSR Studies

abstract:
  PbCuTe2O6 is a rare example of a spin liquid candidate featuring a three
dimensional magnetic lattice. Strong geometric frustration arises from the
dominant antiferromagnetic interaction which generates a hyperkagome network of
Cu2+ ions although additional interactions enhance the magnetic lattice
connectivity. Through a combination of magnetization measurements and local
probe investigation by NMR and muSR down to 20 mK, we provide a robust evidence
for the absence of magnetic freezing in the ground state. The local spin
susceptibility probed by the NMR shift hardly deviates from the macroscopic one
down to 1 K pointing to a homogeneous magnetic system with a low defect
concentration. The saturation of the NMR shift and the sublinear power law
temperature (T) evolution of the 1/T1 NMR relaxation rate at low T point to a
non-singlet ground state favoring a gapless fermionic description of the
magnetic excitations. Below 1 K a pronounced slowing down of the spin dynamics
is witnessed, which may signal a reconstruction of spinon Fermi surface.
Nonetheless, the compound remains in a fluctuating spin liquid state down to
the lowest temperature of the present investigation.


title: Constraint satisfaction problems for reducts of homogeneous graphs

abstract:
  For $n\geq 3$, let $(H_n, E)$ denote the $n$-th Henson graph, i.e., the
unique countable homogeneous graph with exactly those finite graphs as induced
subgraphs that do not embed the complete graph on $n$ vertices. We show that
for all structures $\Gamma$ with domain $H_n$ whose relations are first-order
definable in $(H_n,E)$ the constraint satisfaction problem for $\Gamma$ is
either in P or is NP-complete.
  We moreover show a similar complexity dichotomy for all structures whose
relations are first-order definable in a homogeneous graph whose reflexive
closure is an equivalence relation.
  Together with earlier results, in particular for the random graph, this
completes the complexity classification of constraint satisfaction problems of
structures first-order definable in countably infinite homogeneous graphs: all
such problems are either in P or NP-complete.


title: $\eta$ MAID-2015: update with new data and new resonances

abstract:
  Recent data for $\eta$ and $\eta\prime$ photoproduction on protons obtained
by the A2 Collaboration at MAMI are presented. The total cross section for
$\eta$ photoproduction demonstrates a cusp at the energy corresponding to the
$\eta\prime$ threshold. The new data and existing data from GRAAL, CBELSA/TAPS,
and CLAS collaborations have been analyzed by an expansion in terms of
associated Legendre polynomials. %A Legendre decomposition shows the
sensitivity to small partial-wave contributions. The isobar model $\eta$MAID
updated with $\eta \prime$ channel and new resonances have been used to fit the
new data. The new solution $\eta$MAID-2015 reasonably good describes the data
in the photon beam energy region up to 3.7 GeV.


title: A dichotomy of self-conformal subsets of the real line with overlaps

abstract:
  We show that self-conformal subsets of $\mathbb{R}$ that do not satisfy the
weak separation condition have full Assouad dimension. Combining this with a
recent results by K\"aenm\"aki and Rossi we conclude that an interesting
dichotomy applies to self-conformal and not just self-similar sets: if
$F\subset\mathbb{R}$ is self-conformal with Hausdorff dimension strictly less
than $1$, either the Hausdorff dimension and Assouad dimension agree or the
Assouad dimension is $1$. We conclude that the weak separation property is in
this case equivalent to Assouad and Hausdorff dimension coinciding. (This
manuscript contains errors, see comment below.)


title:
What is the distribution of the number of unique original items in a
  bootstrap sample?

abstract:
  Sampling with replacement occurs in many settings in machine learning,
notably in the bagging ensemble technique and the .632+ validation scheme. The
number of unique original items in a bootstrap sample can have an important
role in the behaviour of prediction models learned on it. Indeed, there are
uncontrived examples where duplicate items have no effect. The purpose of this
report is to present the distribution of the number of unique original items in
a bootstrap sample clearly and concisely, with a view to enabling other machine
learning researchers to understand and control this quantity in existing and
future resampling techniques. We describe the key characteristics of this
distribution along with the generalisation for the case where items come from
distinct categories, as in classification. In both cases we discuss the normal
limit, and conduct an empirical investigation to derive a heuristic for when a
normal approximation is permissible.


title:
Polynomial approximation via compressed sensing of high-dimensional
  functions on lower sets

abstract:
  This work proposes and analyzes a compressed sensing approach to polynomial
approximation of complex-valued functions in high dimensions. Of particular
interest is the setting where the target function is smooth, characterized by a
rapidly decaying orthonormal expansion, whose most important terms are captured
by a lower (or downward closed) set. By exploiting this fact, we present an
innovative weighted $\ell_1$ minimization procedure with a precise choice of
weights, and a new iterative hard thresholding method, for imposing the
downward closed preference. Theoretical results reveal that our computational
approaches possess a provably reduced sample complexity compared to existing
compressed sensing techniques presented in the literature. In addition, the
recovery of the corresponding best approximation using these methods is
established through an improved bound for the restricted isometry property. Our
analysis represents an extension of the approach for Hadamard matrices in [5]
to the general case of continuous bounded orthonormal systems, quantifies the
dependence of sample complexity on the successful recovery probability, and
provides an estimate on the number of measurements with explicit constants.
Numerical examples are provided to support the theoretical results and
demonstrate the computational efficiency of the novel weighted $\ell_1$
minimization strategy.


title:
First observation of low-energy {\gamma}-ray enhancement in the
  rare-earth region

abstract:
  The {\gamma}-ray strength function and level density in the quasi-continuum
of 151,153Sm have been measured using BGO shielded Ge clover detectors of the
STARLiTeR system. The Compton shields allow for an extraction of the {\gamma}
strength down to unprecedentedly low {\gamma} energies of about 500 keV. For
the first time an enhanced low- energy {\gamma}-ray strength has been observed
in the rare-earth region. In addition, for the first time both the upbend and
the well known scissors resonance have been observed simultaneously for the
same nucleus. Hauser-Feshbach calculations show that this strength enhancement
at low {\gamma} energies could have an impact of 2-3 orders of magnitude on the
(n,{\gamma}) reaction rates for the r-process nucleosynthesis.


title: Scaling limits of disordered systems and disorder relevance

abstract:
  We review recent works where we have shown that disorder relevance is closely
related to the existence of non-trivial, random continuum limits


title: Does generation of magnetic storm depend on type of solar wind?

abstract:
  The purpose of this work is to draw attention of readers to a problem of
possible differences in generation of magnetic storms induced by various large
scale solar wind (SW) streams: CIR, Sheath and ICME (including MC and Ejecta).
Recently we showed that when using a modification of formula by Burton et al.
[1975] for connection of interplanetary conditions with Dst and Dst* indices
the efficiency of storm generation by Sheath and CIR is about 50 percent higher
than generation by ICME [Nikolaeva et al., 2013, 2015]. In the literature there
are many various functions coupling (FC) various interplanetary parameters with
magnetospheric state. In this work we study the efficiency of main phase storm
generation by different SW streams when using 12 another FCs on the basis of
OMNI data during 1976 ... 2000. Obtained results show that for most part of FCs
Sheaths have the highest efficiency and MCs have the lowest efficiency in
accordance with our previous results. The reliability of the obtained data and
possible reasons of divergences for various FCs and various SW types require
further researches.


title: Alpha-particle clustering in excited expanding self-conjugate nuclei

abstract:
  The fragmentation of quasi-projectiles from the nuclear reaction 40Ca + 12C
at 25 MeV/nucleon was used to produce alpha-emission sources. From a careful
selection of these sources provided by a complete detection and from
comparisons with models of sequential and simultaneous decays, strong
indications in favour of $\alpha$-particle clustering in excited 16O, 20Ne and
24}Mg are reported.


title:
A General Modifier-based Framework for Inconsistency-Tolerant Query
  Answering

abstract:
  We propose a general framework for inconsistency-tolerant query answering
within existential rule setting. This framework unifies the main semantics
proposed by the state of art and introduces new ones based on cardinality and
majority principles. It relies on two key notions: modifiers and inference
strategies. An inconsistency-tolerant semantics is seen as a composite modifier
plus an inference strategy. We compare the obtained semantics from a
productivity point of view.


title: Property Checking Without Invariant Generation

abstract:
  We introduce a procedure for proving safety properties. This procedure is
based on a technique called Partial Quantifier Elimination (PQE). In contrast
to complete quantifier elimination, in PQE, only a part of the formula is taken
out of the scope of quantifiers. So, PQE can be dramatically more efficient
than complete quantifier elimination. The appeal of our procedure is twofold.
First, it can prove a property without generating an inductive invariant.
Second, it employs depth-first search and so can be used to find deep bugs.


title:
Automated optimisation of multi-level models of collective behaviour in
  a mixed society of animals and robots

abstract:
  Animal and robotic collective behaviours can exhibit complex dynamics that
require multi-level descriptions. Here, we are interested in developing a
multi-level modeling framework for the use of robots in studies about animal
collective decision-making. In this context, using robots can be useful for
validating models in silico, inducing calibrated repetitive stimuli to trigger
animal responses or modulating and controlling animal collective behaviour.
However, designing appropriate biomimetic robotic behaviour faces a major
challenge: how to go from the collective decision dynamics observed with
animals to an actual algorithmic implementation in robots. In previous work,
this was mainly done by hand, often by taking inspiration from human-designed
models. Typically, models of behaviour are either macroscopic, differential
equations of the population dynamics, or microscopic,explicit spatio-temporal
state of each individual. Only microscopic models can easily be implemented as
robot controllers. Here, we address the problem of automating the design of
lower level description models that can be implemented in robots and exhibit
the same collective dynamics as a given higher level model. We apply
evolutionary algorithms to simultaneously optimise the parameters of models
accounting for different levels of description. This methodology is applied to
an experimentally validated shelter-selection problem solved by gregarious
insects and robots. We successfully design and calibrate automatically both a
microscopic and a hybrid model exhibiting the same dynamics as a macroscopic
one. Our framework can be used for multi-level modeling of collective behaviour
in animal or robot populations and bio-hybrid systems.


title: Eilenberg Theorems for Free

abstract:
  Eilenberg-type correspondences, relating varieties of languages (e.g. of
finite words, infinite words, or trees) to pseudovarieties of finite algebras,
form the backbone of algebraic language theory. Numerous such correspondences
are known in the literature. We demonstrate that they all arise from the same
recipe: one models languages and the algebras recognizing them by monads on an
algebraic category, and applies a Stone-type duality. Our main contribution is
a variety theorem that covers e.g. Wilke's and Pin's work on
$\infty$-languages, the variety theorem for cost functions of Daviaud,
Kuperberg, and Pin, and unifies the two previous categorical approaches of
Boja\'nczyk and of Ad\'amek et al. In addition we derive a number of new
results, including an extension of the local variety theorem of Gehrke,
Grigorieff, and Pin from finite to infinite words.


title: ProQ3: Improved model quality assessments using Rosetta energy terms

abstract:
  Motivation: To assess the quality of a protein model, i.e. to estimate how
close it is to its native structure, using no other information than the
structure of the model has been shown to be useful for structure prediction.
The state of the art method, ProQ2, is based on a machine learning approach
that uses a number of features calculated from a protein model. Here, we
examine if these features can be exchanged with energy terms calculated from
Rosetta and if a combination of these terms can improve the quality assessment.
Results: When using the full atom energy function from Rosetta in ProQRosFA the
QA is on par with our previous state-of-the-art method, ProQ2. The method based
on the low-resolution centroid scoring function, ProQRosCen, performs almost as
well and the combination of all the three methods, ProQ2, ProQRosFA and
ProQCenFA into ProQ3 show superior performance over ProQ2. Availability: ProQ3
is freely available on BitBucket at https://bitbucket.org/ElofssonLab/proq3


title: An efficient method for sorting and selecting for social behaviour

abstract:
  In this article we provide a systematic experimental method for sorting
animals according to socially relevant traits, without assaying them or even
tagging them individually. Instead, they are repeatedly subjected to
behavioural assays in groups, between which the group memberships are
rearranged, in order to test the effect of many different combinations of
individuals on a group-level property or feature. We analyse this method using
a general model for the group feature, and simulate a variety of specific cases
to track how individuals are sorted in each case. We find that in the case
where the members of a group contribute equally to the group feature, the
sorting procedure increases the between-group behavioural variation well above
what is expected for groups randomly sampled from a population. For a wide
class of group feature models, the individual phenotypes are efficiently sorted
across the groups and thus become available for further analysis on how
individual properties affect group behaviour. We also show that the
experimental data can be used to estimate the individual-level repeatability of
the underlying traits.


title: Unfolding problem clarification and solution validation

abstract:
  The unfolding problem formulation for correcting experimental data
distortions due to finite resolution and limited detector acceptance is
discussed. A novel validation of the problem solution is proposed. Attention is
drawn to fact that different unfolded distributions may satisfy the validation
criteria, in which case a conservative approach using entropy is suggested. The
importance of analysis of residuals is demonstrated.

categories: physics.data-an astro-ph.IM hep-ex nucl-ex stat.AP


title: Cognitive Network Cooperation for Green Cellular Networks

abstract:
  In recent years, there has been a growing interest in green cellular networks
for the sake of reducing the energy dissipated by communications and networking
devices, including the base stations (BSs) and battery-powered user terminals
(UTs). This paper investigates the joint employment of cognition and
cooperation techniques invoked for improving the energy efficiency of cellular
networks. To be specific, the cellular devices first have to identify the
unused spectral bands (known as spectrum holes) using their spectrum sensing
functionality. Then, they cooperate for exploiting the detected spectrum holes
to support energy-efficient cellular communications. Considering the fact that
contemporary terminals (e.g., smart phones) support various wireless access
interfaces, we exploit either the Bluetooth or the Wi-Fi network operating
within the spectrum holes for supporting cellular communications with the
intention of achieving energy savings. This approach is termed as
\emph{cognitive network cooperation}, since different wireless access networks
cognitively cooperate with cellular networks. In order to illustrate the energy
efficiency benefits of using both cognition and cooperation, we study the
cooperation between television stations (TVSs) and BSs in transmitting to UTs
relying on an opportunistic exploitation of the TV spectrum, where the unused
TV spectral band is utilized in an opportunistic way, depending on whether it
is detected to be idle (or not). It is shown that for a given number of
information bits to be transmitted, the total energy consumed is significantly
reduced, when both cognition and cooperation are supported in cellular
networks, as compared to the conventional direct transmission, pure cognition
and pure cooperation.


title: RadioLensfit: Bayesian weak lensing measurement in the visibility domain

abstract:
  Observationally, weak lensing has been served so far by optical surveys due
to the much larger number densities of background galaxies achieved, which is
typically by two to three orders of magnitude compared to radio. However, the
high sensitivity of the new generation of radio telescopes such as the Square
Kilometre Array (SKA) will provide a density of detected galaxies that is
comparable to that found at optical wavelengths, and with significant source
shape measurements to make large area radio surveys competitive for weak
lensing studies. This will lead weak lensing to become one of the primary
science drivers in radio surveys too, with the advantage that they will access
the largest scales in the Universe going beyond optical surveys, like LSST and
Euclid, in terms of redshifts that are probed. RadioLensfit is an adaptation to
radio data of "lensfit", a model-fitting approach for galaxy shear measurement,
originally developed for optical weak lensing surveys. Its key advantage is
working directly in the visibility domain, which is the natural approach to
adopt with radio data, avoiding systematics due to the imaging process. We
present results on galaxy shear measurements, including investigation of
sensitivity to instrumental parameters such as the visibilities gridding size,
based on simulations of individual galaxy visibilities performed by using
SKA1-MID baseline configuration. We get an amplitude of the shear bias in the
method comparable with SKA1 requirements for a population of galaxies with
realistic flux and scalelength distributions estimated from the VLA SWIRE
catalog.


title: Tight Hardness Results for Maximum Weight Rectangles

abstract:
  Given $n$ weighted points (positive or negative) in $d$ dimensions, what is
the axis-aligned box which maximizes the total weight of the points it
contains?
  The best known algorithm for this problem is based on a reduction to a
related problem, the Weighted Depth problem [T. M. Chan, FOCS'13], and runs in
time $O(n^d)$. It was conjectured [Barbay et al., CCCG'13] that this runtime is
tight up to subpolynomial factors. We answer this conjecture affirmatively by
providing a matching conditional lower bound. We also provide conditional lower
bounds for the special case when points are arranged in a grid (a well studied
problem known as Maximum Subarray problem) as well as for other related
problems.
  All our lower bounds are based on assumptions that the best known algorithms
for the All-Pairs Shortest Paths problem (APSP) and for the Max-Weight k-Clique
problem in edge-weighted graphs are essentially optimal.


title: Maximum Weight Independent Set in lClaw-Free Graphs in Polynomial Time

abstract:
  The Maximum Weight Independent Set (MWIS) problem is a well-known NP-hard
problem. For graphs $G_1, G_2$, $G_1+G_2$ denotes the disjoint union of $G_1$
and $G_2$, and for a constant $l \ge 2$, $lG$ denotes the disjoint union of $l$
copies of $G$. A {\em claw} has vertices $a,b,c,d$, and edges $ab,ac,ad$. MWIS
can be solved for claw-free graphs in polynomial time; the first two polynomial
time algorithms were introduced in 1980 by \cite{Minty1980,Sbihi1980}, then
revisited by \cite{NakTam2001}, and recently improved by
\cite{FaeOriSta2011,FaeOriSta2014}, and by \cite{NobSas2011,NobSas2015} with
the best known time bound in \cite{NobSas2015}. Furthermore MWIS can be solved
for the following extensions of claw-free graphs in polynomial time: fork-free
graphs \cite{LozMil2008}, $K_2$+claw-free graphs \cite{LozMos2005}, and
apple-free graphs \cite{BraLozMos2010,BraKleLozMos2008}.
  This manuscript shows that for any constant $l$, MWIS can be solved for
$l$claw-free graphs in polynomial time. Our approach is based on Farber's
approach showing that every $2K_2$-free graph has ${\cal O}(n^2)$ maximal
independent sets \cite{Farbe1989}, which directly leads to a polynomial time
algorithm for MWIS on $2K_2$-free graphs by dynamic programming.
  Solving MWIS for $l$claw-free graphs in polynomial time extends known results
for claw-free graphs, for $lK_2$-free graphs for any constant $l$
\cite{Aleks1991,FarHujTuz1993,Prisn1995,TsuIdeAriShi1977}, for $K_2$+claw-free
graphs, for $2P_3$-free graphs \cite{LozMos2012}, and solves the open questions
for $2K_2+P_3$-free graphs and for $P_3$+claw-free graphs being two of the
minimal graph classes, defined by forbidding one induced subgraph, for which
the complexity of MWIS was an open problem.


title: Emergent kinetic constraints in open quantum systems

abstract:
  Kinetically constrained spin systems play an important role in understanding
key properties of the dynamics of slowly relaxing materials, such as glasses.
So far kinetic constraints have been introduced in idealised models aiming to
capture specific dynamical properties of these systems. However, recently it
has been experimentally shown by [M. Valado et al., arXiv:1508.04384 (2015)]
that manifest kinetic constraints indeed govern the evolution of strongly
interacting gases of highly excited atoms in a noisy environment. Motivated by
this development we address and discuss the question concerning the type of
kinetically constrained dynamics which can generally emerge in quantum spin
systems subject to strong noise. We discuss an experimentally-realizable case
which displays collective behavior, timescale separation and dynamical
reducibility.


title:
Metallic Nickel Silicides: Experiments and Theory for NiSi and First
  Principles Calculations for Other Phases

abstract:
  We report detailed experimental investigation of the transport and magnetic
properties of orthorhombic NiSi along with first principles studies of this
phase and related nickel silicides. Neutron scattering shows no evidence for
magnetism, in agreement with first principles calculations. Comparison of first
principles results and experimental results from our measurements and
literature show a weak electron phonon coupling. We discuss transport and other
properties of NiSi and find behavior characteristic of a weak correlated metal
far from magnetism. Trends among the nickel silicides as a function of nickel
content are discussed.


title:
Local and nonlocal probabilistic cloning of qubit states via partially
  entangled twin photons

abstract:
  Recently, the nonlocal optimal probabilistic cloning (NLOPC) of two
non-orthogonal qubit states has been proposed [Phys. Rev. A 86, 052332 (2012)]
by means of an experimental setup based on a pair of twin photons in a
maximally entangled state. Here we study the performance of the NLOPC protocol
when implemented via a partially entangled state. We show that the errors
introduced by the use of partial entanglement can be undone by applying a
quantum state discrimination process. Since quantum state discrimination is a
probabilistic process the correction succeeds with a certain probability but
produces perfect clones. We also studied how to modified the setup to produce
local copies.


title:
Embeddings of free groups into asymptotic cones of Hamiltonian
  diffeomorphisms

abstract:
  Given a symplectic surface $(\Sigma, \omega)$ of genus $g \ge 4$, we show
that the free group with two generators embeds into every asymptotic cone of
$(\mathrm{Ham}(\Sigma, \omega), d_\mathrm{H})$, where $d_\mathrm{H}$ is the
Hofer metric. The result stabilizes to products with symplectically aspherical
manifolds.


title: The Cohen-Macaulay Property of Affine Semigroup Rings in Dimension 2

abstract:
  Let $k$ be a field and $x,y$ indeterminates over $k$. Let
$R=k[x^a,x^{p_1}y^{s_1},\ldots,x^{p_t}y^{s_t},y^b] \subseteq k[x,y]$. We
calculate the Hilbert polynomial of $(x^a,y^b)$. The multiplicity of this ideal
provides part of a criterion for the ring to be Cohen-Macaulay. Next, we prove
a simple numerical criterion for $R$ to be Cohen-Macaulay in the case when
$t=2$. We also provide a simple algorithm which identifies the monomial
$k$-basis of $R/(x^a,y^b)$. Finally, these simple results are specialized to
the case of projective monomial curves in $\mathbb{P}^3$.


title: The quantum mechanics based on a general kinetic energy

abstract:
  In this paper, we introduce the Schrodinger equation with a general kinetic
energy operator. The conservation law is proved and the probability continuity
equation is deducted in a general sense. Examples with a Hermitian kinetic
energy operator include the standard Schrodinger equation, the relativistic
Schrodinger equation, the fractional Schrodinger equation, the Dirac equation,
and the deformed Schrodinger equation. We reveal that the Klein-Gordon equation
has a hidden non-Hermitian kinetic energy operator. The probability continuity
equation with sources indicates that there exists a different way of
probability transportation, which is probability teleportation. An average
formula is deducted from the relativistic Schrodinger equation, the Dirac
equation, and the K-G equation.


title: Non-equilibrium $8\pi$ Josephson Effect in Atomic Kitaev Wires

abstract:
  We theoretically study a Kitaev wire interrupted by an extra site which gives
rise to super exchange coupling between two Majorana bound states. We show that
this system hosts a tunable, non-equlibrium Josephson effect with a
characteristic $8\pi$ periodicity of the Josephson current. We elucidate the
physical mechanism deriving a minimal model for the junction and confirm its
quantitative accuracy by comparison to the numerical solution of the full
model. The visibility of the $8\pi$ periodicity of the Josephson current is
then studied using time-dependent simulations including the effects of
dephasing and particle losses. Our findings provide a novel signature of
Majorana quasi-particles which is qualitatively different form the behavior of
a conventional superconductor, and can be experimentally verified in cold atom
systems using alkaline-earth-like atoms.


title:
Fractional integral operator for $L^1$ vector fields and its
  applications

abstract:
  This paper studies fractional integral operator for vector fields in weighted
$L^1$. Using the estimates on fractional integral operator and Stein-Weiss
inequalities, we can give a new proof for a class of Caffarelli-Kohn-Nirenberg
inequalities and establish new $\divg$-$\curl$ inequalities for vector fields.


title: Chirality in a quaternionic representation of the genetic code

abstract:
  A quaternionic representation of the genetic code, previously reported by the
authors, is updated in order to incorporate chirality of nucleotide bases and
amino acids. The original representation assigns to each nucleotide base a
prime integer quaternion of norm 7 and involves a function that associates with
each codon, represented by three of these quaternions, another integer
quaternion (amino acid type quaternion) in such a way that the essentials of
the standard genetic code (particulaty its degeneration) are preserved. To show
the advantages of such a quaternionic representation we have, in turn,
associated with each amino acid of a given protein, besides of the type
quaternion, another real one according to its order along the protein (order
quaternion) and have designed an algorithm to go from the primary to the
tertiary structure of the protein by using type and order quaternions. In this
context, we incorporate chirality in our representation by observing that the
set of eight integer quaternions of norm 7 can be partitioned into a pair of
subsets of cardinality four each with their elements mutually conjugates and by
putting they in correspondence one to one with the two sets of enantiomers (D
and L) of the four nucleotide bases adenine, cytosine, guanine and uracil,
respectively. Thus, guided by two diagrams proposed for the codes evolution, we
define functions that in each case assign a L- (D-) amino acid type integer
quaternion to the triplets of D- (L-) bases. The assignation is such that for a
given D-amino acid, the associated integer quaternion is the conjugate of that
one corresponding to the enantiomer L. The chiral type quaternions obtained for
the amino acids are used, together with a common set of order quaternions, to
describe the folding of the two classes, L and D, of homochiral proteins.


title:
Asymptotic growth of trajectories of multifractional Brownian motion,
  with statistical applications to drift parameter estimation

abstract:
  We construct the least-square estimator for the unknown drift parameter in
the multifractional Ornstein-Uhlenbeck model and establish its strong
consistency in the non-ergodic case. The proofs are based on the asymptotic
bounds with probability 1 for the rate of the growth of the trajectories of
multifractional Brownian motion (mBm) and of some other functionals of mBm,
including increments and fractional derivatives. As the auxiliary results
having independent interest, we produce the asymptotic bounds with probability
1 for the rate of the growth of the trajectories of the general Gaussian
process and some functionals of it, in terms of the covariance function of its
increments.


title:
Self Coupling of the Higgs boson in the processes
  $p\,p\,\rightarrow\,ZHHH+X$ and $p\,p\,\rightarrow\,WHHH+X$

abstract:
  To gain some sense about the likelihood of measuring the Higgs boson quartic
coupling, we calculate the contribution to the triple Higgs production cross
section from the subprocesses $q\bar{q}\to ZHHH$ and $q\bar{q}'\to WHHH$. Our
results illustrate that determining this coupling, or even providing
experimental evidence that it exists, will be very difficult.


title: On geometric progressions on hyperelliptic curves

abstract:
  Let $C$ be a hyperelliptic curve over $\mathbb Q$ described by
$y^2=a_0x^n+a_1x^{n-1}+\ldots+a_n$, $a_i\in\mathbb Q$. The points
$P_{i}=(x_{i},y_{i})\in C(\mathbb{Q})$, $i=1,2,...,k,$ are said to be in a
geometric progression of length $k$ if the rational numbers $x_{i}$,
$i=1,2,...,k,$ form a geometric progression sequence in $\mathbb Q$, i.e.,
$x_i=pt^{i}$ for some $p,t\in\mathbb Q$. In this paper we prove the existence
of an infinite family of hyperelliptic curves on which there is a sequence of
rational points in a geometric progression of length at least eight.


title: Signs of Composite Higgs Pair Production at Next-to-Leading Order

abstract:
  In composite Higgs models the Higgs boson arises as a pseudo-Goldstone boson
from a strongly-interacting sector. Fermion mass generation is possible through
partial compositeness accompanied by the appearance of new heavy fermionic
resonances. The Higgs couplings to the Standard Model (SM) particles and
between the Higgs bosons themselves are modified with respect to the SM. Higgs
pair production is sensitive to the trilinear Higgs self-coupling but also to
anomalous couplings like the novel 2-Higgs-2-fermion coupling emerging in
composite Higgs models. The QCD corrections to SM Higgs boson pair production
are known to be large. In this paper we compute, in the limit of heavy loop
particle masses, the next-to-leading order (NLO) QCD corrections to Higgs pair
production in composite Higgs models without and with new heavy fermions. The
relative QCD corrections are found to be almost insensitive both to the
compositeness of the Higgs boson and to the details of the heavy fermion
spectrum, since the leading order cross section dominantly factorizes. With the
obtained results we investigate the question if, taking into account Higgs
coupling constraints, new physics could first be seen in Higgs pair production.
We find this to be the case in the high-luminosity option of the LHC for
composite Higgs models with heavy fermions. We also investigate the invariant
mass distributions at NLO QCD. While they are sensitive to the Higgs
non-linearities and hence anomalous couplings, the influence of the heavy
fermions is much less pronounced.


title: Consensus in Rooted Dynamic Networks with Short-Lived Stability

abstract:
  We consider the problem of solving consensus using deterministic algorithms
in a synchronous dynamic network with unreliable, directional point-to-point
links, which are under the control of a message adversary. In contrast to a
large body of existing work that focuses on oblivious message adversaries where
the communication graphs are picked from a predefined set, we consider message
adversaries where guarantees about stable periods that occur only eventually
can be expressed. We reveal to what extent such eventual stability is necessary
and sufficient, that is, we present the shortest period of stability that
permits solving consensus, a result that should prove quite useful in systems
that exhibit erratic boot-up phases or recover after repeatedly occurring,
massive transient faults. Contrary to the case of longer stability periods,
where we show how standard algorithmic techniques for solving consensus can be
employed, the short-lived nature of the stability phase forces us to use more
unusual algorithmic methods that avoid waiting explicitly for the stability
period to occur.


title: XBF: Scaling up Bloom-filter-based Source Routing

abstract:
  A well known drawback of IP-multicast is that it requires per-group state to
be stored in the routers. Bloom-filter based source-routed multicast remedies
this problem by moving the state from the routers to the packets. However, a
fixed sized Bloom-filter can only store a limited number of items before the
false positive ratio grows too high implying scalability issues. Several
proposals have tried to address these scalability issues in Bloom-filter
forwarding. These proposals, however, unnecessarily increase the forwarding
complexity.
  In this paper, we present Extensible-Bloom-filter (XBF), a new framing and
forwarding solution which effectively circumvents the aforementioned drawbacks.
XBF partitions a network into sub-networks that reflect the network topology
and traffic patterns, and uses a separate fixed-length Bloom-filter in each of
these. We formulate this partition assignment problem into a balanced edge
partitioning problem, and evaluate it with simulations on realistic topologies.
Our results show that XBF scales to very large networks with minimal overhead
and completely eliminates the false-positives that have plagued the traditional
Bloom-filter-based forwarding protocols. It furthermore integrates with SDN
environments, making it highly suitable for deployments in off-the-shelf
SDN-based networks.


title:
Pressure-induced phase transition in Bi$_2$Se$_3$ at 3 GPa: electronic
  topological transition or not?

abstract:
  In recent years, a low pressure transition around P $\sim$ 3 GPa exhibited by
the A$_2$B$_3$-type 3D topological insulators is attributed to an electronic
topological transition (ETT) for which there is no direct evidence either from
theory or experiments. We address this phase transition and other transitions
at higher pressure in bismuth selenide (Bi$_2$Se$_3$) using Raman spectroscopy
at pressure upto 26.2 GPa. We see clear Raman signatures of an isostructural
phase transition at P $\sim$ 2.4 GPa followed by structural transitions at
$\sim$ 10 GPa and 16 GPa. First-principles calculations reveal anomalously
sharp changes in the structural parameters like the internal angle of the
rhombohedral unit cell with a minimum in the c/a ratio near P $\sim$ 3 GPa.
While our calculations reveal the associated anomalies in vibrational
frequencies and electronic bandgap, the calculated $\mathbb{Z}_2$ invariant and
Dirac conical surface electronic structure remain unchanged, showing that there
is no change in the electronic topology at the lowest pressure transition.


title: Efficiency fluctuations of small machines with unknown losses

abstract:
  The efficiency statistics of a small thermodynamic machine has been recently
investigated assuming that the total dissipation was a linear combination of
two currents: the input and output currents. Here, we relax this standard
assumption and reconsider the question of the efficiency fluctuations for a
machine involving three different processes, first in full generality and
second for two different examples. Since the third process may not be
measurable and/or may decrease the machine efficiency, our motivation is to
study the effect of unknown losses in small machines.


title:
TwoPaCo: An efficient algorithm to build the compacted de Bruijn graph
  from many complete genomes

abstract:
  Motivation: De Bruijn graphs have been proposed as a data structure to
facilitate the analysis of related whole genome sequences, in both a population
and comparative genomic settings. However, current approaches do not scale well
to many genomes of large size (such as mammalian genomes). Results: In this
paper, we present TwoPaCo, a simple and scalable low memory algorithm for the
direct construction of the compacted de Bruijn graph from a set of complete
genomes. We demonstrate that it can construct the graph for 100 simulated human
genomes in less then a day and eight real primates in less than two hours, on a
typical shared-memory machine. We believe that this progress will enable novel
biological analyses of hundreds of mammalian-sized genomes. Availability: Our
code and data is available for download from github.com/medvedevgroup/TwoPaCo
Contact: ium125@psu.edu


title:
Convergence of the thresholding scheme for multi-phase mean-curvature
  flow

abstract:
  We consider the thresholding scheme, a time discretization for mean curvature
flow introduced by Merriman, Bence and Osher. We prove a convergence result in
the multi-phase case. The result establishes convergence towards a weak
formulation of mean curvature flow in the BV-framework of sets of finite
perimeter. The proof is based on the interpretation of the thresholding scheme
as a minimizing movement scheme by Esedoglu et. al.. This interpretation means
that the thresholding scheme preserves the structure of (multi-phase) mean
curvature flow as a gradient flow w. r. t. the total interfacial energy. More
precisely, the thresholding scheme is a minimizing movement scheme for an
energy functional that $\Gamma$-converges to the total interfacial energy. In
this sense, our proof is similar to the convergence results of Almgren, Taylor
and Wang and Luckhaus and Sturzenhecker, which establish convergence of a more
academic minimizing movement scheme. Like the one of Luckhaus and
Sturzenhecker, ours is a conditional convergence result, which means that we
have to assume that the time-integrated energy of the approximation converges
to the time-integrated energy of the limit. This is a natural assumption, which
however is not ensured by the compactness coming from the basic estimates.