title:
Extremal trigonometric polynomials and the problem of optimal
  stabilization of chaos

abstract:
  The paper contains an example of harmonic analysis applications to the
problem of chaos stabilization by the DFC methods


title:
Global bifurcation of polygonal relative equilibria for masses, vortices
  and dNLS oscillators

abstract:
  Given a regular polygonal arrangement of identical objects, turning around a
central object (masses, vortices or dNLS oscillators), this paper studies the
global bifurcation of relative equilibria in function of a natural parameter
(central mass, central circulation or amplitude of the oscillation). The
symmetries of the problem are used in order to find the irreducible
representations, the linearization and, with the help of a degree theory, the
symmetries of the bifurcated solutions.


title: Constructing Limited Scale-Free Topologies Over Peer-to-Peer Networks

abstract:
  Overlay network topology together with peer/data organization and search
algorithm are the crucial components of unstructured peer-to-peer (P2P)
networks as they directly affect the efficiency of search on such networks.
Scale-free (powerlaw) overlay network topologies are among structures that
offer high performance for these networks. A key problem for these topologies
is the existence of hubs, nodes with high connectivity. Yet, the peers in a
typical unstructured P2P network may not be willing or able to cope with such
high connectivity and its associated load. Therefore, some hard cutoffs are
often imposed on the number of edges that each peer can have, restricting
feasible overlays to limited or truncated scale-free networks. In this paper,
we analyze the growth of such limited scale-free networks and propose two
different algorithms for constructing perfect scale-free overlay network
topologies at each instance of such growth. Our algorithms allow the user to
define the desired scalefree exponent (gamma). They also induce low
communication overhead when network grows from one size to another. Using
extensive simulations, we demonstrate that these algorithms indeed generate
perfect scale free networks (at each step of network growth) that provide
better search efficiency in various search algorithms than the networks
generated by the existing solutions.


title:
Lepton number and flavour violation in TeV-scale left-right symmetric
  theories with large left-right mixing

abstract:
  The various diagrams leading to neutrinoless double beta decay in the
left-right symmetric model have different relative magnitudes, depending on the
scale of new physics. Neutrinos acquire mass from both type I and/or type II
seesaw terms, making an unambiguous analysis difficult. We study the half-life
for double beta decay in the case of type II and type I dominance, in the
former case including interference terms. If the heavy neutrinos of the type I
seesaw model are at the TeV scale, certain processes can be enhanced. In
particular, there are regions of parameter space in which the so-called lambda-
and eta-diagrams can give sizable contributions to the half-life for the decay.
We perform a detailed study of one such scenario, paying careful attention to
constraints from lepton flavour violation.


title:
TAO pairing: a fully gapped pairing scenario for the Iron-Based
  Superconductors

abstract:
  Motivated by the fully gapped superconductivity in iron-based superconductors
with uncompensated electron pockets, we propose a spin singlet, but orbital
triplet analogue of the superfluid phase of He-3B. We show that orbital
triplets with a nominal d-wave symmetry at the iron sites can transform as
s-wave pairs under rotations about the selenium sites. Linear combinations of
such d$_{xy}$ and d$_{x^{2}-y^{2}}$ triplets form a fully gapped, topological
superconductor. Raman-active excitations are predicted to develop below the
superconducting transition temperature.


title: Color reconnection and flow-like patterns in pp collisions

abstract:
  Increasingly, with the data collected at the LHC we are confronted with the
possible existence of flow in pp collisions. In this work we show that PYTHIA 8
produces flow-like effects in events with multiple hard subcollisions due to
color string formations between final partons from independent hard
scatterings, the so called color reconnection. We present studies of different
identified hadron observables in pp collisions at 7 TeV with the tune 4C.
Studies have been done both for minimum bias and multiplicity intervals in
events with and without color reconnection to isolate the flow-like effect.


title:
Global bifurcation of planar and spatial periodic solutions in the
  restricted n-body problem

abstract:
  The paper deals with the study of a satellite attracted by n primary bodies,
which form a relative equilibrium. We use orthogonal degree to prove global
bifurcation of planar and spatial periodic solutions from the equilibria of the
satellite. In particular, we analyze the restricted three body problem and the
problem of a satellite attracted by the Maxwell's ring relative equilibrium.


title: Pion masses at finite temperature

abstract:
  We present preliminary results on a study about the thermal variation of the
charged and neutral pion masses to one loop, analyzing their electromagnetic
difference, in the context of Chiral Perturbation Theory with two flavours, as
well as using a light resonance model. We find that the pion mass difference
increases for, at least, low and intermediate temperatures, unlike the chiral
limit decreasing result. The axial-vector mixing arising from chiral
restoration smooths the Debye-screening temperature increase. Taking into
account further corrections due to axial and vector resonances, dominated by a1
and rho particles respectively, does not change significantly the ChPT
prediction.


title:
Herschel-ATLAS/GAMA: What determines the far-infrared properties of
  radio-galaxies?

abstract:
  We perform a stacking analysis of H-ATLAS data in order to obtain isothermal
dust temperatures and rest-frame luminosities at 250um (L250), for 1599 radio
sources over the H-ATLAS P1 GAMA area. The radio sample is generated using a
combination of NVSS data and K-band UKIDSS-LAS data, over 0.01<z<0.8. The FIR
properties of the sample are investigated as a function of L_1.4 GHz, z,
projected radio-source size and radio spectral index. In order to search for
stellar-mass dependent relations, we split the parent sample into those sources
which are below and above 1.5 L_{K}^{*}. Correcting for stellar mass and
redshift, we find no relation between the L250 and L_1.4GHz of radio AGN. This
implies that a galaxy's nominal radio luminosity has little or no bearing on
the SFR and/or dust mass content of the host system. The L250 of both the radio
detected and non radio-detected galaxies (defined as those sources not detected
at 1.4GHz but detected in the SDSS with r'<22) rises with increasing z. For
mass and colour matched samples, sub-1.5 L_{K}^{*} and super-1.5 L_{K}^{*}
radio-detected galaxies have 0.89\pm0.18 and 0.49\pm0.12 times the L250 of
their non radio-detected counterparts. We explain these results in terms of the
hotter, denser and richer halo environments massive radio-galaxies maintain and
are embedded in. These results indicate that all massive radio galaxies (>1.5
L_{K}^{*}) may have systematically lower FIR luminosities (~25%) than their
colour-matched non radio-detected counterparts. Compact radio sources (<30kpc)
are associated with higher L250s and dust temperatures than their more extended
(>30kpc) counterparts. The higher dust temperature suggests that this may be
attributed to enhanced SFRs, but whether this is directly or indirectly due to
radio activity (e.g. jet induced or merger-driven SF) is as yet unknown.


title:
Ab initio studies of the tunneling magneto-Seebeck effect: influence of
  magnetic material

abstract:
  We found a strong influence of the composition of the magnetic material on
the temperature dependence of the tunneling magneto-Seebeck effect in $MgO$
based tunnel junctions. We use \textit{ab initio} alloy theory to consider
different $Fe_xCo_{1-x}$ alloys for the ferromagnetic layer. Even a small
change of the composition leads to strong changes in the magnitude or even in
the sign of the tunneling magneto-Seebeck effect. This can explain differences
between recent experimental results. In addition, changing the barrier
thickness from six to ten monolayers of $MgO$ leads also to a non-trivial
change of the temperature dependence. Our results emphasize that the tunneling
magneto-Seebeck effect depends very crucially and is very sensitive to material
parameters and show that further experimental and theoretical investigations
are necessary.


title: Astronomical imaging Fourier spectroscopy at far-infrared wavelengths

abstract:
  The principles and practice of astronomical imaging Fourier transform
spectroscopy (FTS) at far-infrared wavelengths are described. The Mach-Zehnder
interferometer design has been widely adopted for current and future imaging
FTS instruments; we compare this design with two other common interferometer
formats. Examples of three instruments based on the Mach-Zehnder design are
presented. The techniques for retrieving astrophysical parameters from the
measured spectra are discussed using calibration data obtained with the
Herschel SPIRE instrument. The paper concludes with an example of imaging
spectroscopy obtained with the SPIRE FTS instrument.


title: Rough sets determined by tolerances

abstract:
  We show that for any tolerance $R$ on $U$, the ordered sets of lower and
upper rough approximations determined by $R$ form ortholattices. These
ortholattices are completely distributive, thus forming atomistic Boolean
lattices, if and only if $R$ is induced by an irredundant covering of $U$, and
in such a case, the atoms of these Boolean lattices are described. We prove
that the ordered set $\mathit{RS}$ of rough sets determined by a tolerance $R$
on $U$ is a complete lattice if and only if it is a complete subdirect product
of the complete lattices of lower and upper rough approximations. We show that
$R$ is a tolerance induced by an irredundant covering of $U$ if and only if
$\mathit{RS}$ is an algebraic completely distributive lattice, and in such a
situation a quasi-Nelson algebra can be defined on $\mathit{RS}$. We present
necessary and sufficient conditions which guarantee that for a tolerance $R$ on
$U$, the ordered set $\mathit{RS}_X$ is a lattice for all $X \subseteq U$,
where $R_X$ denotes the restriction of $R$ to the set $X$ and $\mathit{RS}_X$
is the corresponding set of rough sets. We introduce the disjoint
representation and the formal concept representation of rough sets, and show
that they are Dedekind--MacNeille completions of $\mathit{RS}$.


title:
Imry-Ma criterion for long-range random field Ising model:
  short-/long-range equivalence in a field

abstract:
  The Ising model in a random field and with power-law decaying ferromagnetic
bonds is studied at zero temperature. Comparing the scaling of the energy
contributions of the ferromagnetic domain wall flip and of the random field a
la Imry-Ma we obtain a threshold value for the power $\rho$ of the long-range
interaction, beyond which no critical behavior occurs. The critical threshold
value is $\rho_c=3/2$, at a difference with the zero field model in which
$\rho_c=2$. This prediction is confirmed by numerical computation of the ground
states below, at, and above this threshold value. Some possible implications
for the critical behavior of spin-glasses in a field are conjectured.


title: Hydrodynamics of cold holographic matter

abstract:
  We show that at any temperature, the low-energy (with respect to the chemical
potential) collective excitations of the transverse components of the
energy-momentum tensor and the global U(1) current in the field theory dual to
the planar RN-AdS4 black hole are simply those of hydrodynamics. That is,
hydrodynamics is applicable even at energy scales much greater than the
temperature. It is applicable even at zero temperature. Specifically, we find
that there is always a diffusion mode with diffusion constant proportional to
the ratio of entropy density to energy density. At low temperatures, the
leading order momentum and temperature dependences of the dispersion relation
of this mode are controlled by the dimension of an operator in the thermal CFT1
dual to the near-horizon Schwarzschild-AdS2 geometry.


title: WW Scattering in the Era of Post Higgs Discovery

abstract:
  More evidences have now been collected at the Large Hadron Collider
suggesting the new 125 - 126 GeV boson is likely the long sought Higgs boson in
the standard model. One pressing question continued being asked by theorists is
whether this Higgs boson is a lone player responsible for the full electroweak
symmetry breaking. Current data still allow room for additional Higgs bosons or
some other UV physics that may play a partial role in electroweak symmetry
breaking as well. We use the WW scattering to investigate such a possibility,
using the two-Higgs-doublet model as a prototype. The WW scattering becomes
strong when the extra Higgs bosons are very heavy. We study the sensitivity of
the partially strong WW scattering signals at the 13 TeV Large Hadron Collider.


title: Multiobjective Firefly Algorithm for Continuous Optimization

abstract:
  Design problems in industrial engineering often involve a large number of
design variables with multiple objectives, under complex nonlinear constraints.
The algorithms for multiobjective problems can be significantly different from
the methods for single objective optimization. To find the Pareto front and
non-dominated set for a nonlinear multiobjective optimization problem may
require significant computing effort, even for seemingly simple problems.
Metaheuristic algorithms start to show their advantages in dealing with
multiobjective optimization. In this paper, we extend the recently developed
firefly algorithm to solve multiobjective optimization problems. We validate
the proposed approach using a selected subset of test functions and then apply
it to solve design optimization benchmarks. We will discuss our results and
provide topics for further research.


title: Broad iron line in the fast spinning neutron-star system 4U 1636-53

abstract:
  We analysed the X-ray spectra of six observations, simultaneously taken with
XMM-Newton and Rossi X-ray Timing Explorer (RXTE), of the neutron star low-mass
X-ray binary 4U 1636-53. The observations cover several states of the source,
and therefore a large range of inferred mass accretion rate. These six
observations show a broad emission line in the spectrum at around 6.5 keV,
likely due to iron. We fitted this line with a set of phenomenological models
of a relativistically broadened line, plus a model that accounts for
relativistically smeared and ionised reflection from the accretion disc. The
latter model includes the incident emission from both the neutron-star surface
or boundary layer and the corona that is responsible for the high-energy
emission in these systems. From the fits with the reflection model we found
that in four out of the six observations the main contribution to the reflected
spectrum comes from the neutron-star surface or boundary layer, whereas in the
other two observations the main contribution to the reflected spectrum comes
from the corona. We found that the relative contribution of these two
components is not correlated to the state of the source. From the
phenomenological models we found that the iron line profile is better described
by a symmetric, albeit broad, profile. The width of the line cannot be
explained only by Compton broadening, and we therefore explored the case of
relativistic broadening. We further found that the direct emission from the
disc, boundary layer, and corona generally evolved in a manner consistent with
the standard accretion disc model, with the disc and boundary layer becoming
hotter and the disc moving inwards as the source changed from the hard in to
the soft state. The iron line, however, did not appear to follow the same
trend.


title: Metastable D-term Dynamical SUSY Breaking

abstract:
  We present the mechanism of the dynamical supersymmetry (SUSY) breaking at
the metastable vacuum in the N=1 U(N) SUSY gauge theory with adjoint
superfields. The dynamical SUSY breaking is triggered by the non-vanishing
D-term coupled to the observable sector, and is realized by the self-consistent
Hartree-Fock approximation of the NJL type while it eventually brings us the
non-vanishing F-term as well. We numerically check the local stability of our
metastable vacuum.


title:
Can PT-Symmetric Quantum Mechanics be a Viable Alternative Quantum
  Theory?

abstract:
  Update: A time-independent $n\times n$ PT-symmetric (and symmetric)
Hamiltonian is diagonalizable since it has all distinct real eigenvalues and
the resulting diagonal matrix is a real symmetric matrix. The diagonalization
results an isometry so there shouldn't be any issue with unitarity and
unfortunately this very elementary mathematical fact somehow did not draw the
authors' attention. However, PT-symmetric quantum mechanics is not out of
trouble. For time-dependent PT-symmetric (and symmetric) Hamiltonians (even
$2\times 2$ ones) the authors observed that there is a violation of unitarity.
Moreover, the first named author showed in his recent article arXiv:1312.7738
that PT-symmetric quantum mechanics is indeed a certain kind of Hermitian
quantum mechanics and that in order for time-evolution to be unitary with
respect to $J$-inner product (one that gives rise to a Hilbert space structure
on the space of state functions), the potential energy operator $V(x)$ must be
real. This means that those complex PT-symmetric Hamiltonians that have been
studied by physicists are unfortunately unphysical. The first named author
discussed in a subsequent article arXiv:1401.5149 that while finite-state
PT-symmetric quantum mechanics with time-independent Hamiltonians is not
physically any different from Hermitian quantum mechanics, PT-symmetric quantum
mechanics exhibits a distinctive symmetry from that of Hermitian quantum
mechanics.


title: Barrier Options under L\'evy Processes: a Simple Short-Cut

abstract:
  In this paper we present a very simple way to price a class of barrier
options when the underlying process is driven by a huge class of L\'evy
processes. To achieve our goal we assume that our market satisfies a symmetry
property. In case of not satisfying that property some approximations can be
obtained.


title:
Connectivity patterns in loop percolation I: the rationality phenomenon
  and constant term identities

abstract:
  Loop percolation, also known as the dense O(1) loop model, is a variant of
critical bond percolation in the square lattice Z^2 whose graph structure
consists of a disjoint union of cycles. We study its connectivity pattern,
which is a random noncrossing matching associated with a loop percolation
configuration. These connectivity patterns exhibit a striking rationality
property whereby probabilities of naturally-occurring events are dyadic
rational numbers or rational functions of a size parameter n, but the reasons
for this are not completely understood. We prove the rationality phenomenon in
a few cases and prove an explicit formula expressing the probabilities in the
"cylindrical geometry" as coefficients in certain multivariate polynomials.
This reduces the rationality problem in the general case to that of proving a
family of conjectural constant term identities generalizing an identity due to
Di Francesco and Zinn-Justin. Our results make use of, and extend, algebraic
techniques related to the quantum Knizhnik-Zamolodchikov equation.


title: Efficiency Analysis of Swarm Intelligence and Randomization Techniques

abstract:
  Swarm intelligence has becoming a powerful technique in solving design and
scheduling tasks. Metaheuristic algorithms are an integrated part of this
paradigm, and particle swarm optimization is often viewed as an important
landmark. The outstanding performance and efficiency of swarm-based algorithms
inspired many new developments, though mathematical understanding of
metaheuristics remains partly a mystery. In contrast to the classic
deterministic algorithms, metaheuristics such as PSO always use some form of
randomness, and such randomization now employs various techniques. This paper
intends to review and analyze some of the convergence and efficiency associated
with metaheuristics such as firefly algorithm, random walks, and L\'evy
flights. We will discuss how these techniques are used and their implications
for further research.


title: Reflections on the hyperbolic plane

abstract:
  The most general solution to the Einstein equations in $4=3+1$ dimensions in
the asymptotical limit close to the cosmological singularity under the BKL
(Belinski-Khalatnikov-Lifshitz) hypothesis, for which space gradients are
neglected and time derivatives only are considered, can be visualized by the
behavior of a billiard ball in a triangular domain on the Upper Poincar\'e Half
Plane (UPHP). The behavior of the billiard system (named 'big billiard') can be
schematized by dividing the succesions of trajectories according to Poincar\'e
return map on the sides of the billiard table, according to the paradigms
implemented by the BKL investigation and by the CB-LKSKS (Chernoff- Barrow-
Lifshitz- Khalatnikov- Sinai- Khanin- Shchur) one. Different maps are obtained,
according to different symmetry-quotienting mechanisms used to analyze the
dynamics according to the symmetries of the billiard domain and to the features
of the geodesics on the UPHP. In the inhomogenous case, new structures have
been uncovered, such that, in this framework, the billiard table (named 'small
billiard') consists of 1/6 of the previous one. The connections between the
symmetry-quotienting mechanisms are further investigated on the UPHP. The
relation between the complete billiard and the small billiard are also further
explained according to the role of Weyl reflections. The quantum properties of
the system are sketched as well, and the physical interpretation of the
wavefunction is further developped. In particular, a physical interpretation
for the symmetry-quotienting maps is proposed, according to the Fourier
decomposition of the energy levels of the wavefunction of the universe, as far
as the meaning of epochs and eras is concerned from a quantum point of view.


title:
Compact K\"ahler threefolds with non-nef canonical bundle and symplectic
  geometry

abstract:
  We show that the nefness of the canonical bundle of compact K\"ahler
threefolds is invariant under deformed symplectic diffeomorphisms.


title:
Existence of generalized totally umbilic 2-spheres in perturbed
  3-spheres

abstract:
  It was recently shown by R. Souam and E. Toubiana that the (non constantly
curved) Berger spheres do not contain totally umbilic surfaces. Nevertheless in
this article we show, by perturbative arguments, that all analytic metrics
sufficiently close to the round metric $g_{0}$ on $\mathbb{S}^{3}$ possess
\textsl{generalized} totally umbilic 2-spheres, namely critical points of the
conformal Willmore functional $\int_{\Sigma}|A^\circ|^{2}\,d\mu_{\gamma}$. The
same is true in the smooth setting provided a suitable non-degeneracy condition
on the traceless Ricci tensor holds. The proof involves a gluing process of two
different finite-dimensional reduction schemes, a sharp asymptotic analysis of
the functional on perturbed umbilic spheres of small radius and a quantitative
Schur-type Lemma in order to treat the cases when the traceless Ricci tensor of
the perturbation is degenerate but not identically zero. For left-invariant
metrics on $SU(2)\cong \mathbb{S}^{3}$ our result implies the existence of
uncountably many distinct Willmore spheres.


title: Higgs Boson Studies at the Tevatron

abstract:
  We combine searches by the CDF and D0 Collaborations for the standard model
Higgs boson with mass in the range 90--200 GeV$/c^2$ produced in the
gluon-gluon fusion, $WH$, $ZH$, $t{\bar{t}}H$, and vector boson fusion
processes, and decaying in the $H\rightarrow b{\bar{b}}$, $H\rightarrow
W^+W^-$, $H\rightarrow ZZ$, $H\rightarrow\tau^+\tau^-$, and $H\rightarrow
\gamma\gamma$ modes. The data correspond to integrated luminosities of up to 10
fb$^{-1}$ and were collected at the Fermilab Tevatron in $p{\bar{p}}$
collisions at $\sqrt{s}=1.96$ TeV. The searches are also interpreted in the
context of fermiophobic and fourth generation models. We observe a significant
excess of events in the mass range between 115 and 140 GeV/$c^2$. The local
significance corresponds to 3.0 standard deviations at $m_H=125$ GeV/$c^2$,
consistent with the mass of the Higgs boson observed at the LHC, and we expect
a local significance of 1.9 standard deviations. We separately combine searches
for $H \to b\bar{b}$, $H \to W^+W^-$, $H\rightarrow\tau^+\tau^-$, and
$H\rightarrow\gamma\gamma$. The observed signal strengths in all channels are
consistent with the presence of a standard model Higgs boson with a mass of 125
GeV/$c^2$.


title: Complex interpolation of couple (X, BMO) for $A_1$-regular lattices

abstract:
  Recent results of A. Lerner concerning certain properties of the
Fefferman-Stein maximal function are applied to show that $(\BMO, X)_\theta =
X^\theta$, $0 < \theta < 1$, for a Banach lattice $X$ of measurable functions
on $\mathbb R^n$ satisfying the Fatou property such that $X$ has order
continuous norm and the Hardy-Littlewood maximal operator $M$ is bounded in
$(X^\alpha)'$ for some $0 < \alpha \leqslant 1$.


title:
Present Velocity and Acceleration in Tide Gauge Records Characterized by
  a Quasi-60 years Periodic Oscillation

abstract:
  The paper describing sea level rise oscillations at Cape Hatteras, USA by
Parker [1] has opened the discussion regarding if the velocity in a tide gauge
record characterized by a quasi-60-year multi-decadal oscillation can be
computed by linear fitting of 30 years of data in two ad-hoc selected times and
if acceleration can then be inferred by comparing these two values as proposed
by Sallenger [2], or if this comparison is meaningless in that the 60-year time
window is the minimum amount of time needed to evaluate the velocity in a
record characterized by a quasi-60-year multi-decadal oscillation and the
acceleration has then to be computed as the time derivative of this velocity as
suggested by Parker [1,3]. For the specific case of The Battery, NY, it is
shown here that the 60-year time window is the minimum time length needed to
compute a velocity, and both the 60-year windows and the all data velocities
are free of any acceleration at the present time. The 30-year time window
velocity of 2009 is not representative of the present sea level rise and the
comparison of the 30-year time window velocity of 2009 and 1979 near a peak and
a valley, respectively, of the 60-year multidecadal oscillation to claim a
present acceleration has no scientific background.


title: Measures of serial extremal dependence and their estimation

abstract:
  The goal of this paper is two-fold: 1. We review classical and recent
measures of serial extremal dependence in a strictly stationary time series as
well as their estimation. 2. We discuss recent concepts of heavy-tailed time
series, including regular variation and max-stable processes. Serial extremal
dependence is typically characterized by clusters of exceedances of high
thresholds in the series. We start by discussing the notion of extremal index
of a univariate sequence, i.e. the reciprocal of the expected cluster size,
which has attracted major attention in the extremal value literature. Then we
continue by introducing the extremogram which is an asymptotic auto-correlation
function for sequences of extremal events in a time series. In this context, we
discuss regular variation of a time series. This notion has been useful for
describing serial extremal dependence and heavy tails in a strictly stationary
sequence. We briefly discuss the tail process coined by Basrak and Segers to
describe the dependence structure of regularly varying sequences in a
probabilistic way. Max-stable processes with Frechet marginals are an important
class of reg- ularly varying sequences. Recently, this class has attracted
attention for modeling and statistical purposes. We apply the extremogram to
max-stable processes. Finally, we discuss estimation of the extremogram both in
the time and frequency domains.


title:
Topological Surface States and Superconductivity in
  [Tl$_4$](Tl$_{1-x}$Sn$_{x}$)Te$_3$ Perovskites

abstract:
  Materials with strong spin-orbit coupling have attracted attention following
the prediction and subsequent discovery of strong two- and three-dimensional
topological insulators in which a topological property of the bulk band
structure of an insulator results in metallic surface states with Dirac-like
dispersion. Here we report the discovery of Dirac-like surface states in the
perovskite superconductor [Tl$_4$]TlTe$_3$ (Tl5Te3) and its non-superconducting
tin-doped derivative, [Tl4](Tl$_{0.4}$Sn$_{0.6}$)Te$_3$, as observed by
angle-resolved photoemission spectroscopy (ARPES). Density functional theory
(DFT) calculations predict a single spin-orbit driven band parity inversion at
the $Z$ point above the Fermi level of Tl5Te3, suggesting the surface states
are protected by Z$_2$ topology. Calculations on [Tl$_4$]SnTe$_3$ show no
parity inversions, implying that a topological transition from non-trivial to
trivial must occur upon doping with tin, i.e.,
[Tl$_4$](Tl$_{1-x}$Sn$_{x}$)Te$_3$. Thus [Tl$_4$]{\it M}Te$_3$ perovskites are
a possible new, non-trigonal class of Z$_2$ topological compounds.
Additionally, as Tl5Te3 is a stoichiometric bulk superconductor, these
perovskites are ideal materials in which to study the interplay between surface
states and bulk superconductivity.


title:
Generalised Gagliardo-Nirenberg inequalities using weak Lebesgue spaces
  and BMO

abstract:
  Using elementary arguments based on the Fourier transform we prove that for
$1 \leq q < p < \infty$ and $s \geq 0$ with $s > n(1/2-1/p)$, if $f \in
L^{q,\infty}(\R^n) \cap \dot{H}^s(\R^n)$ then $f \in L^p(\R^n)$ and there
exists a constant $c_{p,q,s}$ such that
  \[ \|f\|_{L^p} \leq c_{p,q,s} \|f\|_{L^{q,\infty}}^\theta \|f\|_{\dot
H^s}^{1-\theta}, \] where $1/p = \theta/q + (1-\theta)(1/2-s/n)$. In
particular, in $\R^2$ we obtain the generalised Ladyzhenskaya inequality
$\|f\|_{L^4}\le c\|f\|_{L^{2,\infty}}^{1/2}\|f\|_{\dot H^1}^{1/2}$. We also
show that for $s=n/2$ the norm in $\|f\|_{\dot H^{n/2}}$ can be replaced by the
norm in BMO. As well as giving relatively simple proofs of these inequalities,
this paper provides a brief primer of some basic concepts in harmonic analysis,
including weak spaces, the Fourier transform, the Lebesgue Differentiation
Theorem, and Calderon-Zygmund decompositions.


title:
Existence and uniqueness for a coupled parabolic-elliptic model with
  applications to magnetic relaxation

abstract:
  We prove existence, uniqueness and regularity of weak solutions of a coupled
parabolic-elliptic model in two dimensions; we consider the standard equations
of magnetohydrodynamics with the advective terms removed from the velocity
equation. Despite the apparent simplicity of the model, the proof requires
results that are at the limit of what is available, including elliptic
regularity in $L^{1}$ and a strengthened form of the Ladyzhenskaya inequality
  \[ \| f \|_{L^{4}} \leq c \| f \|_{L^{2,\infty}}^{1/2} \| \nabla f
\|_{L^{2}}^{1/2}, \] which we derive using the theory of interpolation. The
model has applications to the method of magnetic relaxation, introduced by
Moffatt (J. Fluid. Mech. 159, 359-378, 1985), to construct stationary Euler
flows with non-trivial topology.


title:
Heat transport in the $XXZ$ spin chain: from ballistic to diffusive
  regimes and dephasing enhancement

abstract:
  In this work we study the heat transport in an XXZ spin-1/2 Heisenberg chain
with homogeneous magnetic field, incoherently driven out of equilibrium by
reservoirs at the boundaries. We focus on the effect of bulk dephasing
(energy-dissipative) processes in different parameter regimes of the system.
The non-equilibrium steady state of the chain is obtained by simulating its
evolution under the corresponding Lindblad master equation, using the time
evolving block decimation method. In the absence of dephasing, the heat
transport is ballistic for weak interactions, while being diffusive in the
strongly-interacting regime, as evidenced by the heat-current scaling with the
system size. When bulk dephasing takes place in the system, diffusive transport
is induced in the weakly-interacting regime, with the heat current
monotonically decreasing with the dephasing rate. In contrast, in the
strongly-interacting regime, the heat current can be significantly enhanced by
dephasing for systems of small size.


title: Electromagnetic Casimir Forces in Elliptic Cylinder Geometries

abstract:
  The scattering theory approach makes it possible to carry out exact
calculations of Casimir energies in any geometry for which the scattering
T-matrix and a partial wave expansion of the free Green's function are
available. We implement this program for the case of a perfectly conducting
elliptic cylinder, thereby completing the set of geometries where
electromagnetic scattering is separable. Particular emphasis is placed on the
case of zero radius, where the elliptic cylinder reduces to a strip.


title: Decoding the riddle of Y(4260) and $Z_c(3900)$

abstract:
  The observation of $Z_c(3900)$ by the BESIII collaboration in the invariant
mass spectrum of $J/\psi\pi^\pm$ in $e^+e^-\to J/\psi\pi^+\pi^-$ at the center
of mass 4.260 GeV suggests the existence of a charged $\bar D D^*+D\bar D^*$
molecular state with $I(J^P)=1(1^+)$, which could be an isovector brother of
the famous X(3872) and an analogue of $Z_b(10610)$ claimed by the Belle
Collaboration. We demonstrate that this observation provides strong evidence
that the mysterious Y(4260) is a $\bar{D}D_1(2420) +D\bar{D}_1(2420)$ molecular
state. Especially, we show that the decay of this molecule naturally populates
low momentum $\bar DD^*$ pairs and leads unavoidably to a cusp at the $\bar
DD^*$ threshold. We discuss the signatures that distinguish such a $\bar DD^*$
cusp from the presence of a true resonance.


title: A measurement-induced optical Kerr interaction

abstract:
  We present a method for implementing a weak optical Kerr interaction
(single-mode Kerr Hamiltonian) in a measurement-based fashion using the common
set of universal elementary interactions for continuous-variable quantum
computation. Our scheme is a conceptually distinct alternative to the use of
naturally occurring, weak Kerr nonlinearities or specially designed nonlinear
media. Instead, we propose to exploit suitable offline prepared quartic ancilla
states together with beam splitters, squeezers, and homodyne detectors. For
perfect ancilla states and ideal operations, our decompositions for obtaining
the measurement-based Kerr Hamiltonian lead to a realization with near-unit
fidelity. Nonetheless, even by using only approximate ancilla states in the
form of superposition states of up to four photons, high fidelities are still
attainable. Our scheme requires four elementary operations and its
deterministic implementation corresponds to about ten ancilla- based gate
teleportations. We test our measurement-based Kerr interaction against an ideal
Kerr Hamiltonian by applying them both to weak coherent states and
single-photon superposition states.


title: Exponential scaling of clock stability with atom number

abstract:
  In trapped-atom clocks, the primary source of decoherence is often the phase
noise of the oscillator. For this case, we derive theoretical performance gains
by combining several atomic ensembles. For example, M ensembles of N atoms can
be combined with a variety of probe periods, to reduce the frequency variance
to M 2^-M times that of standard Ramsey clocks. A similar exponential
improvement is possible if the atomic phases of some of the ensembles evolve at
reduced frequencies. These ensembles may be constructed from atoms or molecules
with lower-frequency transitions, or generated by dynamical decoupling. The
ensembles with reduced frequency or probe period are responsible only for
counting the integer number of 2 pi phase wraps, and do not affect the clock's
systematic errors. Quantum phase measurement with Gaussian initial states
allows for smaller ensemble sizes than Ramsey spectroscopy.


title:
Infrared and ultraviolet cutoffs in variational calculations with a
  harmonic oscillator basis

abstract:
  I abstract from a recent publication [1] the motivations for, analysis in and
conclusions of a study of the ultraviolet and infrared momentum regulators
induced by the necessary truncation of the model spaces formed by a variational
trial wave function. This trial function is built systematically from a
complete set of many-body basis states based upon three-dimensional harmonic
oscillator (HO) functions. Each model space is defined by a truncation of the
expansion characterized by a counting number (N) and by the intrinsic scale
($\hbar\omega$) of the HO basis. Extending both the uv cutoff to infinity and
the ir cutoff to zero is prescribed for a converged calculation. In [1] we
established practical procedures which utilize these regulators to obtain the
extrapolated result from sequences of calculations with model spaces. Finally,
I update this subject by mentioning recent work on our extrapolation
prescriptions which have appeared since the submission of [1]. The numerical
example chosen for this contribution consists of calculations of the ground
state energy of the triton with the "bare" and "soft" Idaho N3LO
nucleon-nucleon (NN) interaction.


title: On the Stability of Some Spline Collocation Implicit Difference Scheme

abstract:
  Boundary problem for linear partial differential algebraic equations system
with multiple characteristic curves is considered. It is supposed that
matrix-functions pencil of the system under consideration is smoothly
equivalent to special canonical form. For this problem, with the help of the
spline collocation method, a difference scheme of arbitrary degree of
approximation with respect to each variable is constructed. Sufficient
conditions for its absolute stability is found.


title: Study of $\psi(3686) \rightarrow \omega K \bar{K} \pi$ decays

abstract:
  Based on 106 million $\psi(3686)$ events collected with the BESIII detector
at the BEPCII, the decay $\psi(3686) \rightarrow \omega K \bar{K} \pi$ is
studied. Enhancements around 1.44 GeV/$c^{2}$ and the $f_{1}(1285)$ are
observed in the mass spectrum of $K \bar{K}\pi$, and the corresponding
branching fractions are measured, as well as the branching fractions of
$\psi(3686) \rightarrow \omega K^{*+}K^{-}+c.c.$ and $\psi(3686) \rightarrow
\omega \bar{K}^{*0}K^{0}+c.c.$, all for the first time.


title:
Video Face Matching using Subset Selection and Clustering of
  Probabilistic Multi-Region Histograms

abstract:
  Balancing computational efficiency with recognition accuracy is one of the
major challenges in real-world video-based face recognition. A significant
design decision for any such system is whether to process and use all possible
faces detected over the video frames, or whether to select only a few "best"
faces. This paper presents a video face recognition system based on
probabilistic Multi-Region Histograms to characterise performance trade-offs
in: (i) selecting a subset of faces compared to using all faces, and (ii)
combining information from all faces via clustering. Three face selection
metrics are evaluated for choosing a subset: face detection confidence, random
subset, and sequential selection. Experiments on the recently introduced MOBIO
dataset indicate that the usage of all faces through clustering always
outperformed selecting only a subset of faces. The experiments also show that
the face selection metric based on face detection confidence generally provides
better recognition performance than random or sequential sampling. Moreover,
the optimal number of faces varies drastically across selection metric and
subsets of MOBIO. Given the trade-offs between computational effort,
recognition accuracy and robustness, it is recommended that face feature
clustering would be most advantageous in batch processing (particularly for
video-based watchlists), whereas face selection methods should be limited to
applications with significant computational restrictions.


title: Fragment-based Time-dependent Density-functional Theory

abstract:
  Using the Runge-Gross theorem that establishes the foundation of
Time-dependent Density Functional Theory (TDDFT) we prove that for a given
electronic Hamiltonian, choice of initial state, and choice of fragmentation,
there is a unique single-particle potential (dubbed time-dependent partition
potential) which, when added to each of the pre-selected fragment potentials,
forces the fragment densities to evolve in such a way that their sum equals the
exact molecular density at all times. This uniqueness theorem suggests new ways
of computing time-dependent properties of electronic systems via fragment-TDDFT
calculations. We derive a formally exact relationship between the partition
potential and the total density, and illustrate our approach on a simple model
system for binary fragmentation in a laser field.


title: Majorana fermions in chains of magnetic atoms on a superconductor

abstract:
  We propose an easy-to-build easy-to-detect scheme for realizing Majorana
fermions at the ends of a chain of magnetic atoms on the surface of a
superconductor. Model calculations show that such chains can be easily tuned
between trivial and topological ground state. In the latter, spatial resolved
spectroscopy can be used to probe the Majorana fermion end states. Decoupled
Majorana bound states can form even in short magnetic chains consisting of only
tens of atoms. We propose scanning tunneling microscopy as the ideal technique
to fabricate such systems and probe their topological properties.


title: Ultrathin Pyrolytic Carbon Films on a Magnetic Substrate

abstract:
  We report the growth of ultrathin pyrolytic carbon (PyC) films on nickel
substrate by using chemical vapor deposition at 1000 {\deg}C under methane
ambience. We find that the ultra-fast cooling is crucial for PyC film
uniformity by controlling the segregation of carbon on nickel. We characterize
the in-plane crystal size of PyC film by using Raman spectroscopy. The Raman
peaks at ~1354 cm-1 and ~1584 cm-1 wavenumbers are used to extract the D and G
bands. The corresponding peak intensities are then used in an excitation energy
dependent equation to calculate the in-plane crystal size. Using Raman area
mapping, the mean value of in-plane crystal size over an area of 100 {\mu}m
${\times}$ 100 {\mu}m is about 22.9 nm with a standard deviation of about 2.4
nm.


title:
Fault Tolerant Quantum Random Number Generator Certified by Majorana
  Fermions

abstract:
  Braiding of Majorana fermions gives accurate topological quantum operations
that are intrinsically robust to noise and imperfection, providing a natural
method to realize fault-tolerant quantum information processing. Unfortunately,
it is known that braiding of Majorana fermions is not sufficient for
implementation of universal quantum computation. Here we show that topological
manipulation of Majorana fermions provides the full set of operations required
to generate random numbers by way of quantum mechanics and to certify its
genuine randomness through violation of a multipartite Bell inequality. The
result opens a new perspective to apply Majorana fermions for robust generation
of certified random numbers, which has important applications in cryptography
and other related areas.


title:
Musielak-Orlicz BMO-Type Spaces Associated with Generalized
  Approximations to the Identity

abstract:
  Let $\mathcal{X}$ be a space of homogenous type and $\varphi:\
\mathcal{X}\times[0,\infty) \to[0,\infty)$ a growth function such that
$\varphi(\cdot,t)$ is a Muckenhoupt weight uniformly in $t$ and
$\varphi(x,\cdot)$ an Orlicz function of uniformly upper type 1 and lower type
$p\in(0,1]$. In this article, the authors introduce a new Musielak-Orlicz
BMO-type space $\mathrm{BMO}^{\varphi}_A(\mathcal{X})$ associated with the
generalized approximation to the identity, give out its basic properties and
establish its two equivalent characterizations, respectively, in terms of the
spaces $\mathrm{BMO}^{\varphi}_{A,\,\mathrm{max}}(\mathcal{X})$ and
$\widetilde{\mathrm{BMO}}^{\varphi}_A(\mathcal{X})$. Moreover, two variants of
the John-Nirenberg inequality on $\mathrm{BMO}^{\varphi}_A(\mathcal{X})$ are
obtained. As an application, the authors further prove that the space
$\mathrm{BMO}^{\varphi}_{\sqrt{\Delta}}(\mathbb{R}^n)$, associated with the
Poisson semigroup of the Laplace operator $\Delta$ on $\mathbb{R}^n$, coincides
with the space $\mathrm{BMO}^{\varphi}(\mathbb{R}^n)$ introduced by L. D. Ky.


title:
Development of an Advanced Automated Method for Solar Filament
  Recognition and Its Scientific Application to a Solar Cycle of MLSO H\alpha\
  Data

abstract:
  We developed a method to automatically detect and trace solar filaments in
H\alpha\ full-disk images. The program is able not only to recognize filaments
and determine their properties, such as the position, the area, the spine, and
other relevant parameters, but also to trace the daily evolution of the
filaments. The program consists of three steps: First, preprocessing is applied
to correct the original images; Second, the Canny edge-detection method is used
to detect filaments; Third, filament properties are recognized through the
morphological operators. To test the algorithm, we applied it to the
observations from the Mauna Loa Solar Observatory (MLSO), and the program is
demonstrated to be robust and efficient. H\alpha\ images obtained by MLSO from
1998 to 2009 are analyzed, and a butterfly diagram of filaments is obtained. It
shows that the latitudinal migration of solar filaments has three trends in the
Solar Cycle 23: The drift velocity was fast from 1998 to the solar maximum;
After the solar maximum, it became relatively slow. After 2006, the migration
became divergent, signifying the solar minimum. About 60% filaments with the
latitudes larger than $50^{\circ}$ migrate towards the polar regions with
relatively high velocities, and the latitudinal migrating speeds in the
northern and the southern hemispheres do not differ significantly in the Solar
Cycle 23.


title:
A hands-on laboratory and computational experience for nanoscale
  materials, devices and systems education for electronics, spintronics and
  optoelectronics

abstract:
  To enhance the undergraduate and graduate engineering education for nanoscale
materials, devices and systems, we report a multi-disciplinary course based on
the integration of theory, hands-on laboratory and hands-on computation into a
single curriculum. The hands-on laboratory modules span various
dimensionalities of nanomaterials as well as applications in logic, memory, and
energy harvesting. In the hands-on computational exercises, students simulate
the material and the device characteristics, and in some cases, design the
experimental process flow to fabricate and characterize the devices and
systems. Such a course not only grooms the students for multi-disciplinary
collaborative activities in nanoscience and nanoengineering, but also prepares
them well for future academic or industrial pursuit in this area.


title: Extracting the information backbone in online system

abstract:
  Information overload is a serious problem in modern society and many
solutions such as recommender system have been proposed to filter out
irrelevant information. In the literature, researchers mainly dedicated to
improve the recommendation performance (accuracy and diversity) of the
algorithms while overlooked the influence of topology of the online user-object
bipartite networks. In this paper, we find that some information provided by
the bipartite networks is not only redundant but also misleading. With such
"less can be more" feature, we design some algorithms to improve the
recommendation performance by eliminating some links from the original
networks. Moreover, we propose a hybrid method combining the time-aware and
topology-aware link removal algorithms to extract the backbone which contains
the essential information for the recommender systems. From the practical point
of view, our method can improve the performance and reduce the computational
time of the recommendation system, thus improve both of their effectiveness and
efficiency.


title: Convex Tensor Decomposition via Structured Schatten Norm Regularization

abstract:
  We discuss structured Schatten norms for tensor decomposition that includes
two recently proposed norms ("overlapped" and "latent") for
convex-optimization-based tensor decomposition, and connect tensor
decomposition with wider literature on structured sparsity. Based on the
properties of the structured Schatten norms, we mathematically analyze the
performance of "latent" approach for tensor decomposition, which was
empirically found to perform better than the "overlapped" approach in some
settings. We show theoretically that this is indeed the case. In particular,
when the unknown true tensor is low-rank in a specific mode, this approach
performs as good as knowing the mode with the smallest rank. Along the way, we
show a novel duality result for structures Schatten norms, establish the
consistency, and discuss the identifiability of this approach. We confirm
through numerical simulations that our theoretical prediction can precisely
predict the scaling behavior of the mean squared error.


title: On transverse invariants from Khovanov homology

abstract:
  O. Plamenevskaya associated to each transverse knot K an element of the
Khovanov homology of K. In this paper, we give two refinements of
Plamenevskaya's invariant, one valued in Bar-Natan's deformation of the
Khovanov complex and another as a cohomotopy element of the Khovanov spectrum.
We show that the first of these refinements is invariant under negative flypes
and SZ moves; this implies that Plamenevskaya's class is also invariant under
these moves. We go on to show that for small-crossing transverse knots K, both
refinements are determined by the classical invariants of K.


title: Detecting Friendship Within Dynamic Online Interaction Networks

abstract:
  In many complex social systems, the timing and frequency of interactions
between individuals are observable but friendship ties are hidden. Recovering
these hidden ties, particularly for casual users who are relatively less
active, would enable a wide variety of friendship-aware applications in domains
where labeled data are often unavailable, including online advertising and
national security. Here, we investigate the accuracy of multiple statistical
features, based either purely on temporal interaction patterns or on the
cooperative nature of the interactions, for automatically extracting latent
social ties. Using self-reported friendship and non-friendship labels derived
from an anonymous online survey, we learn highly accurate predictors for
recovering hidden friendships within a massive online data set encompassing 18
billion interactions among 17 million individuals of the popular online game
Halo: Reach. We find that the accuracy of many features improves as more data
accumulates, and cooperative features are generally reliable. However,
periodicities in interaction time series are sufficient to correctly classify
95% of ties, even for casual users. These results clarify the nature of
friendship in online social environments and suggest new opportunities and new
privacy concerns for friendship-aware applications that do not require the
disclosure of private friendship information.


title:
On the ergodic theory of certain non-discrete actions and topological
  orbit equivalences

abstract:
  Quasi-invariant measures for non-discrete groups of diffeomorphisms
containing a Morse-Smale dynamics are studied. The assumption concerning the
presence of a Morse-Smale dynamics allows us to extend to higher dimensions a
number of recently established results for non-discrete groups acting on the
circle. These results are also applied to show that, for many groups as above,
every continuous orbit equivalence must coincide almost everywhere with a
diffeomorphism of the corresponding manifold.


title: Stem-Like Adaptive Aneuploidy and Cancer Quasispecies

abstract:
  We analyze and reinterpret experimental evidence from the literature to argue
for an ability of tumor cells to self-regulate their aneuploidy rate. We
conjecture that this ability is mediated by a diversification factor that
exploits molecular mechanisms common to embryo stem cells and, to a lesser
extent, adult stem cells, that is eventually reactivated in tumor cells.
Moreover, we propose a direct use of the quasispecies model to cancer cells
based on their significant genomic instability (i.e. aneuploidy rate), by
defining master sequences lengths as the sum of all copy numbers of physically
distinct whole and fragmented chromosomes. We compute an approximate error
threshold such that any aneuploidy rate larger than the threshold would lead to
a loss of fitness of a tumor population, and we confirm that highly aneuploid
cancer populations already function with aneuploidy rates close to the
estimated threshold.


title: One-dimensional Neel walls under applied external fields

abstract:
  We present a detailed analysis of one-dimensional N\'eel walls in thin
uniaxial ferromagnetic films in the presence of an in-plane applied external
field in the direction normal to the easy axis. Within the reduced
one-dimensional thin film model, we formulate a non-local variational problem
whose minimizers are given by one-dimensional N\'eel wall profiles. We prove
existence, uniqueness (up to translations and reflections), regularity, strict
monotonicity and the precise asymptotics of the decay of the minimizers in the
considered variational problem.


title:
Mahler measures as linear combinations of $L$-values of multiple modular
  forms

abstract:
  We study the Mahler measures of certain families of Laurent polynomials in
two and three variables. Each of the known Mahler measure formulas for these
families involves $L$-values of at most one newform and/or at most one
quadratic character. In this paper, we show, either rigorously or numerically,
that the Mahler measures of some polynomials are related to $L$-values of
multiple newforms and quadratic characters simultaneously. The results suggest
that the number of modular $L$-values appearing in the formulas significantly
depends on the shape of the algebraic value of the parameter chosen for each
polynomial. As a consequence, we also obtain new formulas relating special
values of hypergeometric series evaluated at algebraic numbers to special
values of $L$-functions.


title:
Simulation of Fractional Brownian Surfaces via Spectral Synthesis on
  Manifolds

abstract:
  Using the spectral decomposition of the Laplace-Beltrami operator we simulate
fractal surfaces as random series of eigenfunctions. This approach allows us to
generate random fields over smooth manifolds of arbitrary dimension,
generalizing previous work with fractional Brownian motion with
multi-dimensional parameter. We give examples of surfaces with and without
boundary and discuss implementation.


title:
Linear complexity of generalized cyclotomic sequences of order 4 over
  F_l

abstract:
  Generalized cyclotomic sequences of period pq have several desirable
randomness properties if the two primes p and q are chosen properly. In
particular,Ding deduced the exact formulas for the autocorrelation and the
linear complexity of these sequences of order 2. In this paper, we consider the
generalized sequences of order 4. Under certain conditions, the linear
complexity of these sequences of order 4 is developed over a finite field F_l.
Results show that in many cases they have high linear complexity.


title:
On drift parameter estimation for reflected fractional
  Ornstein-Uhlenbeck processes

abstract:
  We consider a reflected Ornstein-Uhlenbeck process $X$ driven by a fractional
Brownian motion with Hurst parameter $H\in (0, \frac12) \cup (\frac12, 1)$. Our
goal is to estimate an unknown drift parameter $\alpha\in (-\infty,\infty)$ on
the basis of continuous observation of the state process. We establish Girsanov
theorem for the process $X$, derive the standard maximum likelihood estimator
of the drift parameter $\alpha$, and prove its strong consistency and
asymptotic normality. As an improved estimator, we obtain the explicit formulas
for the sequential maximum likelihood estimator and its mean squared error by
assuming the process is observed until a certain information reaches a
specified precision level. The estimator is shown to be unbiased, uniformly
normally distributed, and efficient in the mean square error sense.


title:
A New Procedure for Microarray Experiments to Account for Experimental
  Noise and the Uncertainty of Probe Response

abstract:
  Although microarrays are routine analysis tools in biomedical research, they
still yield noisy output that often requires experimental confirmation. Many
studies have aimed at optimizing probe design and statistical analysis to
tackle this problem. However, less emphasis has been placed on controlling the
noise inherent to the experimental approach. To address this problem, we
investigate here a procedure that controls for such experimental variance and
combine it with an assessment of probe performance. Two custom arrays were used
to evaluate the procedure: one based on 25mer probes from an Affymetrix design
and the other based on 60mer probes from an Agilent design. To assess
experimental variance, all probes were replicated ten times. To assess probe
performance, the probes were calibrated using a dilution series of target
molecules and the signal response was fitted to an absorption model. We found
that significant variance of the signal could be controlled by averaging across
probes and removing probes that are nonresponsive. Thus, a more reliable signal
could be obtained using our procedure than conventional approaches. We suggest
that once an array is properly calibrated, absolute quantification of signals
becomes straight forward, alleviating the need for normalization and reference
hybridizations.


title:
High performance fiber-coupled NbTiN superconducting nanowire single
  photon detectors with Gifford-McMahon cryocooler

abstract:
  We present high performance fiber-coupled niobium titanium nitride
superconducting nanowire single photon detectors fabricated on thermally
oxidized silicon substrates. The best device showed a system detection
efficiency (DE) of 74%, dark count rate of 100 c/s, and full width at half
maximum timing jitter of 68 ps under a bias current of 18.0 uA with a practical
Gifford-McMahon cryocooler system. We also introduced six detectors into the
cryocooler and confirmed that the system DE of all detectors was higher than
67% at the dark count rate of 100 c/s.


title:
The Myogenic Response in Isolated Rat Cerebrovascular Arteries: Smooth
  Muscle Cell Model

abstract:
  Previous models of the cerebrovascular smooth muscle cell have not addressed
the interaction between the electrical, chemical and mechanical components of
cell function during the development of active tension. These models are
primarily electrical, biochemical or mechanical in their orientation, and do
not permit a full exploration of how the smooth muscle responds to electrical
or mechanical forcing. To address this issue, we have developed a new model
that consists of two major components: electrochemical and chemomechanical
subsystems of the cell. Included in the electrochemical model are models of the
electrophysiological behavior of the cell membrane, fluid compartments, Ca2+
release and uptake by the sarcoplasmic reticulum, and cytosolic Ca2+ buffering,
particularly by calmodulin. With this subsystem model, we can study the
mechanics of the production of intracellular Ca2+ transient in response to
membrane voltage clamp pulses. The chemomechanical model includes models of:
(a) the chemical kinetics of myosin phosphorylation, and the formation of
phosphorylated myosin cross-bridges with actin, as well as, attached latch-type
cross-bridges; and (b) a model of force generation and mechanical coupling to
the contractile filaments and their attachments to protein structures and the
skeletal framework of the cell. The two subsystem models are tested
independently and compared with data. Likewise, the complete (combined) cell
model responses to voltage pulse stimulation under isometric and isotonic
conditions are calculated and compared with measured single cell length-force
and force-velocity data obtained from literature. This integrated cell model
provides biophysically-based explanations of electrical, chemical and
mechanical phenomena in cerebrovascular smooth muscle, and has considerable
utility as an adjunct to laboratory research and experimental design.


title:
Stability and Convergence of an Upwind Finite Difference Scheme for the
  Radiative Transport Equation

abstract:
  An explicit numerical scheme is proposed for solving the initial-boundary
value problem for the radiative transport equation in a rectangular domain with
completely absorbing boundary condition. An upwind finite difference
approximation is applied to the differential terms of the equation, and the
composite trapezoidal rule to the scattering integral. The main results are
positivity, stability, and convergence of the scheme. It is also shown that the
scheme can be regarded as an iterative method for finding numerical solutions
to the stationary transport equation. Some numerical examples for the
two-dimensional problems are given.


title:
The Simplest Models of Radiative Neutrino Mass: Excluding Simplified Zee
  Models and Beyond

abstract:
  The complexity of radiative neutrino-mass models can be judged by: (i)
whether they require the imposition of ad hoc symmetries, (ii) the number of
new multiplets they introduce, and (iii) the number of arbitrary parameters
that appear. Adopting the view that the imposition of arbitrary new symmetries
is the least appealing approach, the simplest models have two new multiplets
and a minimal number of new parameters. With this in mind, we search for the
simplest models of radiative neutrino mass. We are lead to two new models,
containing a real scalar triplet and a charged scalar doublet (respectively),
in addition to the charged singlet scalar considered by Zee [h^+\sim(1,1,2)].
The new models are essentially simplified versions of the Zee model and appear
to be \emph{the simplest} models of radiative neutrino mass. However, these
models are only of pedagogical interest; despite successfully generating
nonzero masses, present-day data is sufficient to rule them out. The lessons
learned from these models also enable one to exclude a more general class of
radiative models. Moving beyond the minimal cases, we find a new model of
two-loop masses that employs the charged doublet \Phi\sim(1,2,3) and the
doubly-charged scalar k^{++}\sim(1,1,4).


title: Dynamics of Trust Reciprocation in Heterogenous MMOG Networks

abstract:
  Understanding the dynamics of reciprocation is of great interest in sociology
and computational social science. The recent growth of Massively Multi-player
Online Games (MMOGs) has provided unprecedented access to large-scale data
which enables us to study such complex human behavior in a more systematic
manner. In this paper, we consider three different networks in the EverQuest2
game: chat, trade, and trust. The chat network has the highest level of
reciprocation (33%) because there are essentially no barriers to it. The trade
network has a lower rate of reciprocation (27%) because it has the obvious
barrier of requiring more goods or money for exchange; morever, there is no
clear benefit to returning a trade link except in terms of social connections.
The trust network has the lowest reciprocation (14%) because this equates to
sharing certain within-game assets such as weapons, and so there is a high
barrier for such connections because they require faith in the players that are
granted such high access. In general, we observe that reciprocation rate is
inversely related to the barrier level in these networks. We also note that
reciprocation has connections across the heterogeneous networks. Our
experiments indicate that players make use of the medium-barrier reciprocations
to strengthen a relationship. We hypothesize that lower-barrier interactions
are an important component to predicting higher-barrier ones. We verify our
hypothesis using predictive models for trust reciprocations using features from
trade interactions. Using the number of trades (both before and after the
initial trust link) boosts our ability to predict if the trust will be
reciprocated up to 11% with respect to the AUC.


title:
Statistical mechanics of Coulomb gases as quantum theory on Riemann
  surfaces

abstract:
  Statistical mechanics of 1D multivalent Coulomb gas may be mapped onto
non-Hermitian quantum mechanics. We use this example to develop instanton
calculus on Riemann surfaces. Borrowing from the formalism developed in the
context of Seiberg-Witten duality, we treat momentum and coordinate as complex
variables. Constant energy manifolds are given by Riemann surfaces of genus
$g\geq 1$. The actions along principal cycles on these surfaces obey ODE in the
moduli space of the Riemann surface known as Picard-Fuchs equation. We derive
and solve Picard-Fuchs equations for Coulomb gases of various charge content.
Analysis of monodromies of these solutions around their singular points yields
semiclassical spectra as well as instanton effects such as Bloch bandwidth.
Both are shown to be in perfect agreement with numerical simulations.

categories: cond-mat.stat-mech hep-th math-ph math.MP


title:
Message Passing Algorithm for Distributed Downlink Regularized
  Zero-forcing Beamforming with Cooperative Base Stations

abstract:
  Base station (BS) cooperation can turn unwanted interference to useful signal
energy for enhancing system performance. In the cooperative downlink,
zero-forcing beamforming (ZFBF) with a simple scheduler is well known to obtain
nearly the performance of the capacity-achieving dirty-paper coding. However,
the centralized ZFBF approach is prohibitively complex as the network size
grows. In this paper, we devise message passing algorithms for realizing the
regularized ZFBF (RZFBF) in a distributed manner using belief propagation. In
the proposed methods, the overall computational cost is decomposed into many
smaller computation tasks carried out by groups of neighboring BSs and
communications is only required between neighboring BSs. More importantly, some
exchanged messages can be computed based on channel statistics rather than
instantaneous channel state information, leading to significant reduction in
computational complexity. Simulation results demonstrate that the proposed
algorithms converge quickly to the exact RZFBF and much faster compared to
conventional methods.


title:
Phase Transition Analysis of Sparse Support Detection from Noisy
  Measurements

abstract:
  This paper investigates the problem of sparse support detection (SSD) via a
detection-oriented algorithm named Bayesian hypothesis test via belief
propagation (BHT-BP). Our main focus is to compare BHT-BP to an
estimation-based algorithm, called CS-BP, and show its superiority in the SSD
problem. For this investigation, we perform a phase transition (PT) analysis
over the plain of the noise level and signal magnitude on the signal support.
This PT analysis sharply specifies the required signal magnitude for the
detection under a certain noise level. In addition, we provide an experimental
validation to assure the PT analysis. Our analytical and experimental results
show the fact that BHT-BP detects the signal support against additive noise
more robustly than CS-BP does.


title: A double ion trap for large Coulomb crystals

abstract:
  While the linear radiofrequency trap finds various applications in
high-precision spectroscopy and quantum information, its higher-order cousin,
the linear multipole trap, is almost exclusively employed in physical
chemistry. Recently, first experiments have shown interesting features by
laser-cooling multipole-trapped ion clouds. Multipole traps show a flatter
potential in their centre and therefore a modified density distribution
compared to quadrupole traps. Micromotion is an important issue and will
certainly influence the dynamics of crystallized ion structures. Our experiment
tends to investigate possible crystallization processes in the multipole. In a
more general way, we are interested in the study of the dynamics and
thermodynamics of large ion clouds in traps of different geometry.


title: A Note on k-support Norm Regularized Risk Minimization

abstract:
  The k-support norm has been recently introduced to perform correlated
sparsity regularization. Although Argyriou et al. only reported experiments
using squared loss, here we apply it to several other commonly used settings
resulting in novel machine learning algorithms with interesting and familiar
limit cases. Source code for the algorithms described here is available.


title:
Noether invariants for constant mean curvature surfaces in 3-dimensional
  homogeneous spaces

abstract:
  We give explicit formul{\ae} for Noether invariants associated to Killing
vector fields for the variational problem of minimal and constant mean
curvature surfaces in 3-manifolds. In the case of homogeneous spaces, such
invariants are the flux (associated to translations) and the torque (associated
to rotations). Then we focus on homogeneous spaces with isometry groups of
dimensions 3 or 4 and study the behavior of these invariants under the action
of isometries. Finally, we give examples of actual computations and of
interpretations of these invariants in different situations.


title: Decays of Higgs Boson into Pseudoscalar Meson Pair of Different Flavours

abstract:
  The flavour-changing quark-Higgs coupling does not arise at the tree level in
the Standard Model. It is, however, induced by one-loop effects. In this paper,
we present an exact calculation of the Higgs-penguin vertex in the
tHooft-Feynman gauge. Renormalization of the vertex is effected by a
prescription by Chia and Chong which gives an expression for the counter term
identical to that obtained by employing Ward-Takahashi identity. The on-shell
vertex function for the Higgs-penguin vertex is obtained, and its dependence on
Higgs mass is investigated. Our calculation is applied to the following
process: decays of Higgs boson into pseudoscalar meson pair of different
flavours: Kpi and BK. The coupling of pseudoscalar meson to quark is effected
through a gamma5 coupling. The decay rates are found to be very small.


title: The second law of thermodynamics for pure quantum states

abstract:
  A version of the second law of thermodynamics states that one cannot lower
the energy of an isolated system by a cyclic operation. We prove this law
without introducing statistical ensembles and by resorting only to quantum
mechanics. We choose the initial state as a pure quantum state whose energy is
almost E_0 but not too sharply concentrated at energy eigenvalues. Then after
an arbitrary unitary time evolution which follows a typical "waiting time", the
probability of observing the energy lower than E_0 is proved to be negligibly
small.


title: Hybrid model of GeV-TeV gamma ray emission from Galactic Center

abstract:
  The observations of high energy $\gamma$-ray emission from the Galactic
center (GC) by HESS, and recently by Fermi, suggest the cosmic ray acceleration
in the GC and possibly around the supermassive black hole. In this work we
propose a lepton-hadron hybrid model to explain simultaneously the GeV-TeV
$\gamma$-ray emission. Both electrons and hadronic cosmic rays were accelerated
during the past activity of the GC. Then these particles would diffuse outwards
and interact with the interstellar gas and background radiation field. The
collisions between hadronic cosmic rays with gas is responsible to the TeV
$\gamma$-ray emission detected by HESS. With fast cooling in the strong
radiation field, the electrons would cool down and radiate GeV photons through
inverse Compton scattering off the soft background photons. This scenario
provides a natural explanation of the observed GeV-TeV spectral shape of
$\gamma$-rays.


title:
Efficient Site-specific Low-energy Electron Production via Interatomic
  Coulombic Decay Following Resonant Auger Decay

abstract:
  We identified interatomic Coulombic decay (ICD) channels in argon dimers
after spectator-type resonant Auger decay $2p^{-1}~3d \to 3p^{-2}3d, 4d$ in one
of the atoms, using momentum resolved electron-ion-ion coincidence. The results
illustrate that the resonant core excitation is a very efficient way of
producing slow electrons at a specific site, which may cause localized
radiation damage. We find also that ICD rate for $3p^{-2}4d$ is significantly
lower than that for $3p^{-2}3d$.


title: Cold gas in the inner regions of intermediate redshift clusters

abstract:
  Determining gas content and star formation rate has known remarkable progress
in field galaxies, but has been much less investigated in galaxies inside
clusters. We present the first CO observations of luminous infrared galaxies
(LIRGs) inside the virial radii of two intermediate redshift clusters,
CL1416+4446 (z=0.397) and CL0926+1242 (z=0.489). We detect three galaxies at
high significance (5 to 10 sigma), and provide robust estimates of their CO
luminosities, L'CO. In order to put our results into a general context, we
revisit the relation between cold and hot gas and stellar mass in nearby field
and cluster galaxies. We find evidence that at fixed LIR (or fixed stellar
mass), the frequency of high L'CO galaxies is lower in clusters than in the
field, suggesting environmental depletion of the reservoir of cold gas. The
level of star formation activity in a galaxy is primarily linked to the amount
of cold gas, rather than to the galaxy mass or the lookback time. In clusters,
just as in the field, the conversion between gas and stars seems universal. The
relation between LIR and L'CO for distant cluster galaxies extends the relation
of nearby galaxies to higher IR luminosities. Nevertheless, the intermediate
redshift galaxies fall well within the dispersion of the trend defined by local
systems. Considering that L'CO is generally derived from the CO(1-0) line and
sensitive to the vast majority of the molecular gas in the cold interstellar
medium of galaxies, but less to the part which will actually be used to form
stars, we suggest that molecular gas can be stripped before the star formation
rate is affected. Combining the sample of Geach et al. (2009, 2011) and ours,
we find evidence for a decrease in CO towards the cluster centers. This is the
first hint of an environmental impact on cold gas at intermediate redshift.


title:
Conditions for detectability in distributed consensus-based observer
  networks

abstract:
  The paper discusses fundamental detectability properties associated with the
problem of distributed state estimation using networked observers. The main
result of the paper establishes connections between detectability of the plant
through measurements, observability of the node filters through
interconnections, and algebraic properties of the underlying communication
graph, to ensure the interconnected filtering error dynamics are stabilizable
via output injection.


title: Low lying spectroscopy of odd-odd $^{146}$Eu

abstract:
  Electron Capture (EC) decay of $^{146}$Gd($\it{t_{1/2}}$ = 48d) to the low
lying states of $^{146}$Eu has been studied using high-resolution $\gamma$ ray
spectroscopy. The $^{146}$Gd activity was produced by ($\alpha$, 2n) reaction
at E$_{\alpha}$ = 32 MeV using 93.8% enriched $^{144}$Sm target. The level
structure has been considerably modified from the measurement of $\gamma$ ray
singles, $\gamma\gamma$ coincidences and decay half lives. Lifetime measurement
has been performed for the 3$^-$ (114.06 keV) and 2$^-$ (229.4 keV) levels of
$^{146}$Eu using Mirror Symmetric Centroid Difference (MSCD) method with
LaBr$_3$ (Ce) detectors. The lifetimes for these two states have been found to
be 5.38 $\pm$ 2.36 ps and 8.38 $\pm$ 2.19 ps respectively. Shell model
calculation has been performed using OXBASH code in order to interpret the
results.


title:
High quality superconducting tunnel junction barriers using atomic layer
  deposition

abstract:
  We demonstrate a technique for creating high quality, large area tunnel
junction barriers for normal-insulating- superconducting or
superconducting-insulating-superconducting tunnel junctions. We use atomic
layer depo- sition and an aluminum wetting layer to form a nanometer scale
insulating barrier on gold films. Electronic transport measurements confirm
that single-particle electron tunneling is the dominant transport mechanism,
and the measured current-voltage curves demonstrate the viability of using
these devices as self-calibrated, low temperature thermometers with a wide
range of tunable parameters. The potential for fabricating high performance
junction refrigerators is also highlighted.


title: Enhanced Higgs diphoton rate and isospin symmetric Higgs boson

abstract:
  Based on Ref.1, we introduce a model with an isospin symmetric Higgs boson
and study the properties of this particle, including the enhancement of its
diphoton decay rate. The predictions of the model relevant for future
experiments are also discussed.


title: A new look into the spectral and light variations of epsilon Aur

abstract:
  Investigating long series of spectral and photometric observations, we found
that the orbital elements of epsilon Aur are subject to much larger
uncertainties than usually believed. The H alpha emission is found to move
basically with the F primary but its exact location should still be
investigated. We also find strong additional absorption and large reddening of
the object near the third contact during the eclipse. Episodic atmospheric mass
transfer from the F primary towards its companion is tentatively suggested.


title: A new variable in scalar cosmology with exponential potential

abstract:
  We present a new way describing the solution of the Einstein-scalar field
theory with exponential potential $V\propto e^{\sqrt{6}\beta \phi/M_{Pl}}$ in
spatially flat Friedmann-Robertson-Walker space-time. We introduced a new time
variable, $L$, which may vary in $[-1,1]$. The new time represents the state of
the universe clearly because the equation of state at a given time takes the
simple form, $w= -1+ 2L^2$. The universe will inflate when $|L|<1/\sqrt{3}$.
For $\beta\leq 1$, the universe ends with its evolution at $L=\beta$. This
implies that the equation of state at the end of the universe is nothing but
$w=-1+2\beta^2$. For $\beta \geq 1$, the universe ends at L=1, where the
equation of state of the universe is one. On the other hand, the universe
always begins with $w=1$ at $L=\pm 1$.


title: Multipartite Entanglement Witnesses

abstract:
  We derive a set of algebraic equations, the so-called multipartite
separability eigenvalue equations. Based on their solutions, we introduce a
universal method for the construction of multipartite entanglement witnesses.
We witness multipartite entanglement of $10^3$ coupled quantum oscillators, by
solving our basic equations analytically. This clearly demonstrates the
feasibility of our method for studying ultra-high orders of multipartite
entanglement in complex quantum systems.


title: Robertson-Schroedinger Uncertainty Relation Refined by Skew Information

abstract:
  We report a refinement of Robertson-Schroedinger uncertainty relation via
Wigner-Yanase skew information. Besides the well known quantum uncertainty
arising from the noncommutativity of observables, there is classical
uncertainty arising from the mixedness of the states that is quantified by the
difference between the variance and the skew information. Our refined
uncertainty relation for canonical observables is saturated by all the Gaussian
states, pure or mixed, and thus provides an alternative measure for the
non-Gaussianity of quantum states. Generalizations to the case of metric
adjusted skew information are presented, unifying and refining most of previous
results.


title: Distribution of Entropy Production in a Single-Electron Box

abstract:
  Recently, the fundamental laws of thermodynamics have been reconsidered for
small systems. The discovery of the fluctuation relations has spurred
theoretical and experimental studies on thermodynamics of systems with few
degrees of freedom. The concept of entropy production has been extended to the
microscopic level by considering stochastic trajectories of a system coupled to
a heat bath. However, the experimental observation of the microscopic entropy
production remains elusive. We measure distributions of the microscopic entropy
production in a single-electron box consisting of two islands with a tunnel
junction. The islands are coupled to separate heat baths at different
temperatures, maintaining a steady thermal non-equilibrium. As Jarzynski
equality between work and free energy is not applicable in this case, the
entropy production becomes the relevant parameter. We verify experimentally
that the integral and detailed fluctuation relations are satisfied.
Furthermore, the coarse-grained entropy production from trajectories of
electronic transitions is related to the bare entropy production by a universal
formula. Our results reveal the fundamental roles of irreversible entropy
production in non-equilibrium small systems.


title: The center of a quantized enveloping algebra at an even root of unity

abstract:
  We will give an explicit description of the center of the De Concini-Kac type
specialization of a quantized enveloping algebra at an even root of unity. The
case of an odd root of unity was already dealt with by De Concini-Kac-Procesi.
Our description in the even case is similar to but a little more complicated
than the odd case.


title: A quasi-complete mechanical model for a double torsion pendulum

abstract:
  We present a dynamical model for the double torsion pendulum nicknamed PETER,
where one torsion pendulum hangs in cascade, but off-axis, from the other. The
dynamics of interest in these devices lies around the torsional resonance, that
is at very low frequencies (mHz). However, we find that, in order to properly
describe the forced motion of the pendulums, also other modes must be
considered, namely swinging and bouncing oscillations of the two suspended
masses, that resonate at higher frequencies (Hz). Although the system has
obviously 6+6 Degrees of Freedom, we find that 8 are sufficient for an accurate
description of the observed motion. This model produces reliable estimates of
the response to generic external disturbances and actuating forces or torques.
In particular, we compute the effect of seismic floor motion (tilt noise) on
the low frequency part of the signal spectra and show that it properly accounts
for most of the measured low frequency noise.


title: Medium effects on the viscosities of a pion gas

abstract:
  The bulk and shear viscosities of a pion gas is obtained by solving the
relativistic transport equation in the Chapman-Enskog approximation. In-medium
effects are introduced in the $\pi\pi$ cross-section through one-loop
self-energies in the propagator of the exchanged $\rho$ and $\sigma$ mesons.
The effect of early chemical freeze-out in heavy ion collisions is implemented
through a temperature dependent pion chemical potential. These are found to
affect the temperature dependence of the bulk and shear viscosities
significantly.


title: Information Measures for Deterministic Input-Output Systems

abstract:
  In this work the information loss in deterministic, memoryless systems is
investigated by evaluating the conditional entropy of the input random variable
given the output random variable. It is shown that for a large class of systems
the information loss is finite, even if the input is continuously distributed.
Based on this finiteness, the problem of perfectly reconstructing the input is
addressed and Fano-type bounds between the information loss and the
reconstruction error probability are derived.
  For systems with infinite information loss a relative measure is defined and
shown to be tightly related to R\'{e}nyi information dimension. Employing
another Fano-type argument, the reconstruction error probability is bounded by
the relative information loss from below.
  In view of developing a system theory from an information-theoretic
point-of-view, the theoretical results are illustrated by a few example
systems, among them a multi-channel autocorrelation receiver.


title:
Unconditionally optimal error analysis of fully discrete Galerkin
  methods for general nonlinear parabolic equations

abstract:
  The paper focuses on unconditionally optimal error analysis of the fully
discrete Galerkin finite element methods for a general nonlinear parabolic
system in $\R^d$ with $d=2,3$. In terms of a corresponding time-discrete system
of PDEs as proposed in \cite{LS1}, we split the error function into two parts,
one from the temporal discretization and one the spatial discretization. We
prove that the latter is $\tau$-independent and the numerical solution is
bounded in the $L^{\infty}$ and $W^{1,\infty}$ norms by the inverse
inequalities. With the boundedness of the numerical solution, optimal error
estimates can be obtained unconditionally in a routine way. Several numerical
examples in two and three dimensional spaces are given to support our
theoretical analysis.


title:
Post-Processing Enhancement of Reverberation-Noise Suppression in
  Dual-Frequency SURF Imaging

abstract:
  A post-processing adjustment technique which aims for enhancement of
dual-frequency SURF (Second order UltRasound Field) reverberation-noise
suppression imaging in medical ultrasound is analyzed. Two variant methods are
investigated through numerical simulations. They both solely involve
post-processing of the propagated high-frequency (HF) imaging wave fields,
which in real-time imaging corresponds to post-processing of the beamformed
receive radio-frequency signals. Hence the transmit pulse complexes are the
same as for the previously published SURF reverberation-suppression imaging
method. The adjustment technique is tested on simulated data from propagation
of SURF pulse complexes consisting of a 3.5 MHz HF imaging pulse added to a 0.5
low-frequency sound-speed manipulation pulse. Imaging transmit beams are
constructed with and without adjustment. The post-processing involves
filtering, e.g., by a time-shift, in order to equalize the two SURF HF pulses
at a chosen depth. This depth is typically chosen to coincide with the depth
where the first scattering or reflection occurs for the reverberation noise one
intends to suppress. The beams realized with post-processing show energy
decrease at the chosen depth, especially for shallow depths where in a medical
imaging situation often a body-wall is located. This indicates that the
post-processing may further enhance the reverberation-suppression abilities of
SURF imaging. Moreover, it is shown that the methods might be utilized to
reduce the accumulated near-field energy of the SURF transmit-beam relative to
its imaging region energy. The adjustments presented may therefore potentially
be utilized to attain a slightly better general suppression of multiple
scattering and multiple reflection noise compared to for non-adjusted SURF
reverberation-suppression imaging.


title:
Cross-section measurement of some deuteron induced reactions on
  $^{160}$Gd for possible production of the therapeutic radionuclide $^{161}$Tb

abstract:
  The radionuclide 161Tb (T1/2=6.89 d) is potentially important for internal
radiotherapy. It is generally produced through the 160Gd(n,{\gamma})161Gd -
161Tb route at research reactors. In this work the possibility of its
production at a cyclotron was investigated. Determination of the excitation
function of the 160Gd(d,x)161Tb production route and that of the disturbing
160Gd(d,2n)160Tb side reaction was done over the deuteron energy range up to 50
MeV using the stacked-foil technique and high-resolution gamma-ray
spectrometry. A comparison of this production route with the established
(n,\gamma) reaction at a nuclear reactor is made.


title: Forty years of UBV photometry at Hvar

abstract:
  The history of the program of systematic UBV photometric monitoring of Be
stars, binaries, CP stars and some other targets is briefly summarized. It is
shown that a careful data homogenization, reduction and transformation to the
standard Johnson system can be carried out successfully even at a station
nearly the sea level when some strict measures are taken.


title:
Wetting of soap bubbles on hydrophilic, hydrophobic and superhydrophobic
  surfaces

abstract:
  Wetting of sessile bubbles on solid and liquid surfaces has been studied. A
model is presented for the contact angle of a sessile bubble based on a
modified Young equation - the experimental results agree with the model. A
hydrophilic surface results in a bubble contact angle of 90 deg whereas on a
superhydrophobic surface one observes 134 deg. For hydrophilic surfaces, the
bubble angle diminishes with bubble radius - whereas on a superhydrophobic
surface, the bubble angle increases. The size of the Plateau borders governs
the bubble contact angle - depending on the wetting of the surface.


title: A new observable to measure the top-quark mass at hadron colliders

abstract:
  A new method to measure the top-quark mass in high energetic hadron
collisions is presented. We use theoretical predictions calculated at
next-to-leading order accuracy in quantum chromodynamics to study the
(normalized) differential distribution of the \ttbaronejet cross section with
respect to its invariant mass $\sqrt{\sttj}$. The sensitivity of the method to
the top-quark mass together with the impact of various theoretical and
experimental uncertainties has been investigated and quantified. The new method
allows for a complementary measurement of the top-quark mass parameter and has
a high potential to become competitive in precision with respect to established
approaches. Furthermore we emphasize that in the proposed method the mass
parameter is uniquely defined through one-loop renormalization.


title: The Merino-Welsh Conjecture holds for Series-Parallel Graphs

abstract:
  The Merino-Welsh conjecture asserts that the number of spanning trees of a
graph is no greater than the maximum of the numbers of totally cyclic
orientations and acyclic orientations of that graph. We prove this conjecture
for the class of series-parallel graphs.


title:
Activation cross-sections of longer lived radioisotopes of deuteron
  induced nuclear reactions on terbium up to 50 MeV

abstract:
  Experimental cross-sections are presented for the first time for the
159Tb(d,xn)155,157,159Dy, 155,156,160Tb and 153Gd nuclear reactions up to 50
MeV. The experimental data are compared with theoretical predictions of the
ALICE, EMPIRE and TALYS nuclear reaction codes. Integral thick-target yields
are also derived for the reaction products that have practical applications.


title:
Nitrogen isotopes in AGB carbon stars and presolar SiC grains: a
  challenge for stellar nucleosynthesis

abstract:
  Isotopic ratios of C, N, Si, and trace heavy elements in presolar SiC grains
from meteorites provide crucial constraints to nucleosynthesis. A long-debated
issue is the origin of the so-called A+B grains, as for them no stellar
progenitor has so far been clearly identified on observational grounds. We
report the first spectroscopic measurements of 14N/15N ratios in Galactic
carbon stars of different spectral types and show that J- and some SC-type
stars might produce A+B grains, even for 15N enrichments previously attributed
to novae. We also show that most mainstream (MS) grains are compatible with the
composition of N-type stars, but might also descend, in some cases, from SC
stars. From the theoretical point of view, no astrophysical scenario can
explain the C and N isotopic ratios of SC, J and N-type carbon stars together,
as well as those of many grains produced by them. This poses urgent questions
to stellar physics.


title: A new approach to test Lorentz invariance

abstract:
  Lorentz invariance in the weak interaction has been tested rather poorly
compared to the electromagnetic interaction. In this work we show which tests
on the weak interaction should be considered. We focus on one particular test
that explores the spin degree of freedom in {\beta} decay. To connect various
phenomenological tests of Lorentz invariance in the weak interaction, we
exploit a new theoretical model that may provide a framework that relates the
different tests.


title: Examples and counter-examples of log-symplectic manifolds

abstract:
  We study topological properties of log-symplectic structures and produce
examples of compact manifolds with such structures. Notably we show that
several symplectic manifolds do not admit log-symplectic structures and several
log-symplectic manifolds do not admit symplectic structures, for example #m
CP^2 # n bar(CP^2)$ has log-symplectic structures if and only if m,n>0 while
they only have symplectic structures for m=1. We introduce surgeries that
produce log-symplectic manifolds out of symplectic manifolds and show that for
any simply connected 4-manifold M, the manifolds M # (S^2 \times S^2) and M #
CP^2 # CP^2bar have log-symplectic structures and any compact oriented
log-symplectic four-manifold can be transformed into a collection of symplectic
manifolds by reversing these surgeries.


title: Robust Smoothing for Discrete-Time Uncertain Nonlinear Systems

abstract:
  This paper derives recursion equations for a robust smoothing problem for a
class of nonlinear systems with uncertainties in modeling and exogenous noise
sources. The systems considered operate in discrete-time and the uncertainties
are modeled in terms of a sum quadratic constraint. The robust smoothing
problem is solved in terms of a forward-time and a reverse-time filter. Both
these filters are formulated in terms of set-valued state estimators and are
recast into subsidiary optimal control problems. These optimal control problems
are described in terms of discrete-time Hamilton-Jacobi-Bellman equations,
whose approximate solutions lead to recursive Riccati difference equations,
filter state equations, and level shift scalar equations for the forward-time
and the reverse-time filters.


title: Random Discrete Morse Theory and a New Library of Triangulations

abstract:
  1) We introduce random discrete Morse theory as a computational scheme to
measure the complicatedness of a triangulation. The idea is to try to quantify
the frequence of discrete Morse matchings with a certain number of critical
cells. Our measure will depend on the topology of the space, but also on how
nicely the space is triangulated.
  (2) The scheme we propose looks for optimal discrete Morse functions with an
elementary random heuristic. Despite its na\"ivet\'e, this approach turns out
to be very successful even in the case of huge inputs.
  (3) In our view the existing libraries of examples in computational topology
are `too easy' for testing algorithms based on discrete Morse theory. We
propose a new library containing more complicated (and thus more meaningful)
test examples.


title: Strong and Electromagnetic Forces in Heavy Ion Collisions

abstract:
  The interplay between the strong and electromagnetic force in high energy
nucleus-nucleus collisions was studied experimentally and theoretically in our
earlier works. This effect appeared to result in very large distortions in
spectra of charged pions produced in the collision. It was also found to bring
new, independent information on the space-time evolution of the
non-perturbative process of particle production.
  In this paper, we present our new results on the influence of the
spectator-induced electromagnetic force on spectra of charged particles
produced in two different Pb-induced reactions. For the first time, we also
address the topic of p+A collisions in view of obtaining information about
their centrality and nuclear break-up, both subjects being of importance in the
context of the new p+A data collected at the LHC.


title:
Model Checking for Modal Dependence Logic: An Approach Through Post's
  Lattice

abstract:
  In this paper we investigate an extended version of modal dependence logic by
allowing arbitrary Boolean connectives. Modal dependence logic was recently
introduced by Jouko V\"a\"an\"anen by extending modal logic by a the dependence
atom dep(.). In this paper we study the computational complexity of the model
checking problem. For a complete classification of arbitrary Boolean functions
we are using a Lattice approach introduced by Emil Post. This classification is
done for all fragments of the logical language allowing modalities $\Diamond$
and $\Box$, the dependence atom, and logical symbols for arbitrary Boolean
functions.


title: Controlling complex Langevin dynamics at finite density

abstract:
  At nonzero chemical potential the numerical sign problem in lattice field
theory limits the use of standard algorithms based on importance sampling.
Complex Langevin dynamics provides a possible solution, but it has to be
applied with care. In this review, we first summarise our current understanding
of the approach, combining analytical and numerical insight. In the second part
we study SL(N,C) gauge cooling, which was introduced recently as a tool to
control complex Langevin dynamics in nonabelian gauge theories. We present new
results in Polyakov chain models and in QCD with heavy quarks and compare
various adaptive cooling implementations.