title: Curvature flows for almost-hermitian Lie groups

abstract:
  We study curvature flows in the locally homogeneous case (e.g. compact
quotients of Lie groups, solvmanifolds, nilmanifolds) in a unified way, by
considering a generic flow under just a few natural conditions on the broad
class of almost-hermitian structures. As a main tool, we use an ODE system
defined on the variety of 2n-dimensional Lie algebras, called the bracket flow,
whose solutions differ from those to the original curvature flow by only
pull-back by time-dependent diffeomorphisms. The approach, which has already
been used to study the Ricci flow on homogeneous manifolds, is useful to better
visualize the possible pointed limits of solutions, under diverse rescalings,
as well as to address regularity issues. Immortal, ancient and self-similar
solutions arise naturally from the qualitative analysis of the bracket flow.
The Chern-Ricci flow and the symplectic curvature flow are considered in more
detail.


title: Probing modified gravity theories with the Sandage-Loeb test

abstract:
  In this paper, we quantify the ability of a future measurement of the
Sandage-Loeb test signal from the Cosmic-Dynamic-Experiment-like spectrograph
to constrain some popular modified gravity theories including DGP brane-world
scenario, $f(R)$ modified gravity and $f(T)$ gravity theory. We find that the
Sandage-Loeb test measurements are able to break degeneracies between model
parameters markedly and thus greatly improve cosmological constraints for all
concerned modified gravity theories when combined with the latest observations
of CMB--shift parameter. However, they yield almost the same degeneracy
directions between model parameters as that from the distance ratio data
derived from the latest observations of the cosmic microwave background and
baryonic acoustic oscillations (CMB/BAO). Moreover, for the $f(R)$ modified
gravity, the Sandage-Loeb test could provide completely different bounded
regions in model parameters space as compared to CMB/BAO and thus supplement
strong complementary constraints.


title:
The Auslander-Reiten components of the bounded derived category for a
  cluster-tilted algebra of type \~A

abstract:
  We classify the Auslander-Reiten components of the bounded derived category
of \Lambda, where {\Lambda} is a cluster-tilted of type \~A. The main tool is
the combinatoric description of the indecomposable complexes in the bounded
homotopy category via homotopy strings and homotopy bands.


title:
Inhomogeneous Topological Superfluidity in One-Dimensional
  Spin-Orbit-Coupled Fermi Gases

abstract:
  We theoretically predict an exotic topological superfluid state with
spatially modulated pairing gap in one-dimensional spin-orbit-coupled Fermi
gases. This inhomogeneous topological superfluidity is induced by applying
simultaneously a perpendicular Zeeman magnetic field and an equally weighted
Rashba and Dresselhaus spin-orbit coupling in one-dimensional optical lattices.
Based on the self-consistent Bogoliubov--de Gennes theory, we confirm that this
novel topological phase is a unique condensation of Cooper pairs, which
manifests the interplay between the inhomogeneity of superfluid and its
nontrivial topological structure. The properties of the emergent Majorana bound
states are investigated in detail by examining the associated $\mathbb{Z}_{2}$
topological number, the eigenenergy and density of states spectra, as well as
the wave functions of the localized Majorana end modes. Experimental
feasibility of observing this new topological state of matter is also
discussed.


title: Broken planar Skyrmions -- statics and dynamics

abstract:
  The broken planar Skyrme model is a theory that breaks global O(3) symmetry
to the dihedral group D_N. It has been shown that the single soliton solution
is formed of N constituent parts, named partons, that are topologically
confined. The multi-soliton solutions have already been computed for N = 3 and
were shown to be related to polyiamonds. We extend this for larger N and
demonstrate that this polyform structure continues (planar figures formed by
regular N-gons joined along their edges, of which polyiamonds are the N=3
subset). Furthermore, we numerically simulate the dynamics of this model for
the first time. It will be demonstrated that the time dependent behaviour of
these solutions can be broken down into the interactions of its constituent
partons. The results are then compared with those of the standard planar Skyrme
model.


title:
A white dwarf merger as progenitor of the anomalous X-ray pulsar 4U
  0142+61?

abstract:
  It has been recently proposed that massive fast-rotating highly-magnetized
white dwarfs could describe the observational properties of some of Soft
Gamma-Ray Repeaters (SGRs) and Anomalous X-Ray Pulsars (AXPs). Moreover, it has
also been shown that high-field magnetic (HFMWDs) can be the outcome of white
dwarf binary mergers. The products of these mergers consist of a hot central
white dwarf surrounded by a rapidly rotating disk. Here we show that the merger
of a double degenerate system can explain the characteristics of the peculiar
AXP 4U 0142+61. This scenario accounts for the observed infrared excess. We
also show that the observed properties of 4U 0142+6 are consistent with an
approximately $1.2 M_{\sun}$ white dwarf, remnant of the coalescence of an
original system made of two white dwarfs of masses $0.6\, M_{\sun}$ and $1.0\,
M_{\sun}$. Finally, we infer a post-merging age $\tau_{\rm WD}\approx 64$ kyr,
and a magnetic field $B\approx 2\times 10^8$ G. Evidence for such a magnetic
field may come from the possible detection of the electron cyclotron absorption
feature observed between the $B$ and $V$ bands at $\approx 10^{15}$ Hz in the
spectrum of 4U 0142+61.


title:
Optical Interferometry of early-type stars with PAVO@CHARA. I.
  Fundamental stellar properties

abstract:
  We present interferometric observations of 7 main-sequence and 3 giant stars
with spectral types from B2 to F6 using the PAVO beam combiner at the CHARA
array. We have directly determined the angular diameters for these objects with
an average precision of 2.3%. We have also computed bolometric fluxes using
available photometry in the visible and infrared wavelengths, as well as
space-based ultraviolet spectroscopy. Combined with precise \textit{Hipparcos}
parallaxes, we have derived a set of fundamental stellar properties including
linear radius, luminosity and effective temperature. Fitting the latter to
computed isochrone models, we have inferred masses and ages of the stars. The
effective temperatures obtained are in good agreement (at a 3% level) with
nearly-independent temperature estimations from spectroscopy. They validate
recent sixth-order polynomial (B-V)-$T_\mathrm{eff}$ empirical relations
\citep{Boyajian2012a}, but suggest that a more conservative third-order
solution \citep{vanBelle2009} could adequately describe the
(V-K)-$T_\mathrm{eff}$ relation for main-sequence stars of spectral type A0 and
later. Finally, we have compared mass values obtained combining surface gravity
with inferred stellar radius (\textit{gravity mass}) and as a result of the
comparison of computed luminosity and temperature values with stellar
evolutionary models (\textit{isochrone mass}). The strong discrepancy between
isochrone and gravity mass obtained for one of the observed stars,
$\gamma$\,Lyr, suggests that determination of the stellar atmosphere parameters
should be revised.


title:
Short duration high amplitude flares detected on the M dwarf star KIC
  5474065

abstract:
  Using data obtained during the RATS-Kepler project we identified one short
duration flare in a 1 hour sequence of ground based photometry of the dwarf
star KIC 5474065. Observations made using GTC show it is a star with a M4 V
spectral type. Kepler observations made using 1 min sampling show that KIC
5474065 exhibits large amplitude (deltaF/F>0.4) optical flares which have a
duration as short as 10 mins. We compare the energy distribution of flares from
KIC 5474065 with that of KIC 9726699, which has also been observed using 1 min
sampling, and ground based observations of other M dwarf stars in the
literature. We discuss the possible implications of these short duration,
relatively low energy flares would have on the atmosphere of exo-planets
orbiting in the habitable zone of these flare stars.


title: Spontaneous oscillations in simple fluid networks

abstract:
  Nonlinear phenomena including multiple equilibria and spontaneous
oscillations are common in fluid networks containing either multiple phases or
constituent flows. In many systems, such behavior might be attributed to the
complicated geometry of the network, the complex rheology of the constituent
fluids, or, in the case of microvascular blood flow, biological control. In
this paper we investigate two examples of a simple three-node fluid network
containing two miscible Newtonian fluids of differing viscosities, the first
modeling microvascular blood flow and the second modeling stratified laminar
flow. We use a combination of analytic and numerical techniques to identify and
track saddle-node and Hopf bifurcations through the large parameter space. In
both models, we document sustained spontaneous oscillations and, for an
experimentally relevant example of parameter analysis, investigate the
sensitivity of these oscillations to changes in the viscosity contrast between
the constituent fluids and the inlet flow rates. For the case of stratified
laminar flow, we detail a physically realizable set of network parameters that
exhibit rich dynamics. The tools and results developed here are general and
could be applied to other physical systems.


title:
A high-speed multi-protocol quantum key distribution transmitter based
  on a dual-drive modulator

abstract:
  We propose a novel source based on a dual-drive modulator that is adaptable
and allows Alice to choose between various practical quantum key distribution
(QKD) protocols depending on what receiver she is communicating with.
Experimental results show that the proposed transmitter is suitable for
implementation of the Bennett and Brassard 1984 (BB84), coherent one-way (COW)
and differential phase shift (DPS) protocols with stable and low quantum bit
error rate. This could become a useful component in network QKD, where
multi-protocol capability is highly desirable.


title: Mechanical Properties of Warped Membranes

abstract:
  We explore how a frozen background metric affects the mechanical properties
of planar membranes with a shear modulus. We focus on a special class of
"warped membranes" with a preferred random height profile characterized by
random Gaussian variables $h({\bf q})$ in Fourier space with zero mean and
variance $<|h({\bf q})|^2> \sim q^{-d_h}$ and show that in the linear response
regime the mechanical properties depend dramatically on the system size $L$ for
$d_h \ge 2$. Membranes with $d_h=4$ could be produced by flash polymerization
of lyotropic smectic liquid crystals. Via a self consistent screening
approximation we find that the renormalized bending rigidity increases as
$\kappa_R \sim L^{(d_h-2)/2}$ for membranes of size $L$, while the Young and
shear modulii decrease according to $Y_R,\ \mu_R \sim L^{-(d_h-2)/2}$ resulting
in a universal Poisson ratio. Numerical results show good agreement with
analytically determined exponents.


title:
A Robust Multilevel Method for Hybridizable Discontinuous Galerkin
  Method for the Helmholtz Equation

abstract:
  A robust multilevel preconditioner based on the hybridizable discontinuous
Galerkin method for the Helmholtz equation with high wave number is presented
in this paper. There are two keys in our algorithm, one is how to choose a
suitable intergrid transfer operator, and the other is using GMRES smoothing on
coarse grids. The multilevel method is performed as a preconditioner in the
outer GMRES iteration. To give a quantitative insight of our algorithm, we use
local Fourier analysis to analyze the convergence property of the proposed
multilevel method. Numerical results show that for fixed wave number, the
convergence of the algorithm is mesh independent. Moreover, the performance of
the algorithm depends relatively mildly on wave number.


title:
Measurement of the \Sigma\ beam asymmetry for the \omega\
  photo-production off the proton and the neutron at GRAAL

abstract:
  We report on new measurements of the beam asymmetry for \omega\
photo-production on proton and neutron in Hydrogen and Deuterium targets from
the GRAAL collaboration. The beam asymmetry values are extracted from the
reaction threshold (E_{\gamma} = 1.1 GeV in the free nucleon kinematics) up to
1.5 GeV of incoming photon energy. For the first time both the radiative and
the three-pion decay channels are simultaneously investigated on the free
proton. Results from the two decay channels are in agreement and provide
important constraints for the determination of resonant state contributions to
the \omega\ production mechanism. First experimental results on the deuteron
allow the extraction of the \Sigma\ beam asymmetry on quasi-free nucleons.
Comparison of the results for free and quasi-free kinematics on the proton
shows a generally reasonable agreement, similar to the findings in
pseudo-scalar meson photo-production reactions. For the first time measurements
on quasi-free neutrons are available, showing that both the strength and the
angular distributions of the beam asymmetry are sensibly different from the
results on the proton target.


title: Operating experience with electron cloud clearing electrodes at DAFNE

abstract:
  During the current run of an electron-positron collider DAFNE special
electrodes for electron cloud suppression have been inserted in all dipole and
wiggler magnets of the positron ring. In this paper we discuss the impact of
these electrodes on beam dynamics and overall collider performance. In
particular we report results of measurements such as e-cloud instabilities
growth rate, transverse beam size variation, tune shifts along the bunch train
etc. with the electrodes switched on and off that clearly indicate the
effectiveness of the electrodes for e-cloud suppression.


title: Duality in multi-channel Luttinger Liquid with local scatterer

abstract:
  We have devised a general scheme that provides exact results for the scaling
dimensions of all allowed in multi-channel Luttinger Liquids local
perturbations. The technique developed provides universal description and
establishes relations between scaling dimensions of perturbations in different
phases of Luttinger Liquid. These multiple relations between scaling dimensions
are universal. They are valid for all Luttinger Liquids with arbitrary
current-current and density-density interactions. We have also established
duality transformation between different subsets of Luttinger Liquid phases
known for single-channel liquid as duality between weak link and weak scatterer
limits.


title:
The roles of star formation and AGN activity of IRS sources in the
  HerMES fields

abstract:
  In this work we explore the impact of the presence of an active galactic
nucleus (AGN) on the mid- and far-infrared (IR) properties of galaxies as well
as the effects of simultaneous AGN and starburst activity in these same
galaxies. To do this we apply a multi-component, multi-band spectral synthesis
technique to a sample of 250 micron selected galaxies of the Herschel
Multi-tiered Extragalactic Survey, with IRS spectra available for all galaxies.
Our results confirm that the inclusion of the IRS spectra plays a crucial role
in the spectral analysis of galaxies with an AGN component improving the
selection of the best-fit hot dust model (torus). We find a correlation between
the obscured star formation rate (SFR) derived from the IR luminosity of the
starburst component, SFR_IR and SFR_PAH, derived from the luminosity of the PAH
features, L_PAH, with SFR_FIR taking higher values than SFR_PAH. The
correlation is different for AGN- and starburst-dominated objects. The ratio of
L_PAH to that of the starburst component, L_PAH/L_SB, is almost constant for
AGN-dominated objects but decreases with increasing L_SB for
starburst-dominated objects. SFR_FIR increases with the accretion luminosity,
L_acc, with the increase less prominent for the very brightest, unobscured
AGN-dominated sources. We find no correlation between the masses of the hot and
cold dust components. We interpret this as a non-constant fraction of gas
driven by the gravitational effects to the AGN while the starburst is ongoing.
We also find no evidence of the AGN affecting the temperature of the cold dust
component, though this conclusion is mostly based on objects with a
non-dominant AGN component. We conclude that our findings do not provide
evidence that the presence of AGN affects the star formation process in the
host galaxy, but rather that the two phenomena occur simultaneously over a wide
range of luminosities.


title: First Observation of Cabibbo-Suppressed \Xi_c^0 Decays

abstract:
  We report the first observation of the Cabibbo-suppressed decays
$\Xi_c^0\rightarrow \Xi^- K^+$, $\Xi_c^0\ra\Lambda K^+ K^-$ and
$\Xi_c^0\rightarrow \Lambda \phi$, using a data sample of $711\,
\mathrm{fb}^{-1}$ collected at the $\Upsilon(4S)$ resonance with the Belle
detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We measure the
ratios of branching fractions to be $\frac{{\cal B}(\Xi_c^0\ra \Xi^-
K^+)}{{\cal B}(\Xi^0_c\ra\Xi^-\pi^+)}=(2.75\pm 0.51\pm 0.25)\times 10^{-2}$,
$\frac{{\cal B}(\Xi_c^0\ra\Lambda K^+ K^-)}{{\cal B}(\Xi_c^0\rightarrow\Xi^-
\pi^+)}=(2.86\pm 0.61\pm 0.24)\times 10^{-2}$ and $\frac{{\cal B}(\Xi_c^0\ra
\Lambda\phi)}{{\cal B}(\Xi^0_c\ra\Xi^-\pi^+)}=(3.43\pm 0.58\pm 0.32)\times
10^{-2}$, where the first uncertainty is statistical and the second is
systematic.


title:
Crystal field and magnetism of Pr$^{3+}$ and Nd$^{3+}$ ions in
  orthorhombic perovskites

abstract:
  Fifteen parameters characterizing the crystal field of rare-earth ions in the
RMO$_3$ perovskites (R = Pr, Nd, M = Ga, Co) are calculated by expanding the
local Hamiltonian expressed in the basis of Wannier functions into a series of
spherical tensor operators. The method contains a single adjustable parameter
that characterizes the hybridization of R($4f$) states with the states of
oxygen ligands. Subsequently the energy levels and magnetic moments of
trivalent R ion are determined by diagonalization of an effective Hamiltonian
which, besides the crystal field, contains the $4f$ electron-electron
repulsion, spin-orbit coupling and interaction with magnetic field. In the Ga
compounds the energy levels of the ground multiplet agree within few meV with
those determined experimentally by other authors. For all four compounds in
question the temperature dependence of magnetic susceptibility is measured on
polycrystalline samples and compared with the results of calculation. For
NdGaO$_3$ theory is also compared with the magnetic measurements on a single
crystal presented by Luis {\it et al.} Phys. Rev. B {\bf 58}, 798 (1998). A
good agreement between the experiment and theory is found.


title: The Chern Character in the Simplicial de Rham Complex

abstract:
  On the basis of Dupont's work, we exhibit a cocycle in the simplicial de Rham
complex which represents the Chern character. We also prove the related
conjecture due to Brylinski. This gives a way to construct a cocycle in a local
truncated complex.


title: Quantum science and metrology with mixed-species ion chains

abstract:
  This chapter reviews recent developments in the use of mixed-species ion
chains in quantum information science, frequency metrology and spectroscopy. A
growing number of experiments have demonstrated new methods in this area,
opening up new possibilities for quantum state generation, quantum control of
previously inaccessible ions, and the ability to maintain quantum control over
extended periods. I describe these methods, providing details of the techniques
which are required in order to work with such systems. In addition, I present
perspectives on possible future uses of quantum logic spectroscopy techniques,
which have the potential to extend precision control of atomic ions to a large
range of atomic and molecular species.


title: Dual conformal symmetry on the light-cone

abstract:
  We study the properties of conformal operators in the SL(2) sector of planar
N=4 SYM and its supersymmetric SL(2|2) extension. The correlation functions of
these operators and their form factors with respect to asymptotic on-shell
states are determined in the appropriate limit by two different polynomials
which can be identified as eigenstates of the dilatation operator in the
coordinate and momentum representations, respectively. We argue that, in virtue
of integrability of the dilatation operator, the two polynomials satisfy a
duality relation -- they are proportional to each other upon an appropriate
identification of momenta and coordinates. Combined with the conventional N=4
superconformal symmetry, this leads to the dual superconformal symmetry of the
dilatation operator. We demonstrate that this symmetry is powerful enough to
fix the eigenspectrum of the dilatation operator to the lowest order in the
coupling. We use the relation between the one-loop dilatation operator and
Heisenberg spin chain to show that, to lowest order in the coupling, the dual
symmetry is generated by the Baxter Q-operator in the limit of large spectral
parameter.


title: Minimal isometric immersions into S^2 x R and H^2 x R

abstract:
  For a given simply connected Riemannian surface Sigma, we relate the problem
of finding minimal isometric immersions of Sigma into S^2 x R or H^2 x R to a
system of two partial differential equations on Sigma. We prove that a constant
intrinsic curvature minimal surface in S^2 x R or H^2 x R is either totally
geodesic or part of an associate surface of a certain limit of catenoids in H^2
x R. We also prove that if a non constant curvature Riemannian surface admits a
continuous one-parameter family of minimal isometric immersions into S^2 x R or
H^2 x R, then all these immersions are associate.


title: Entangling quantum gate in trapped ions via Rydberg blockade

abstract:
  We present a theoretical analysis of the implementation of an entangling
quantum gate between two trapped Ca$^+$ ions which is based on the dipolar
interaction among ionic Rydberg states. In trapped ions the Rydberg excitation
dynamics is usually strongly affected by mechanical forces due to the strong
couplings between electronic and vibrational degrees of freedom in
inhomogeneous electric fields. We demonstrate that this harmful effect can be
overcome by using dressed states that emerge from the microwave coupling of
nearby Rydberg states. At the same time these dressed states exhibit long range
dipolar interactions which we use to implement a controlled adiabatic phase
gate. Our study highlights a route towards a trapped ion quantum processor in
which quantum gates are realized independently of the vibrational modes.


title:
Acoustically regulated carrier injection into a single optically active
  quantum dot

abstract:
  We study the carrier injection into a single InGaAs/GaAs quantum dot
regulated by a radio frequency surface acoustic wave. We find that the time of
laser excitation during the acoustic cycle programs both the emission
intensities and time of formation of neutral $(X^0)$ and negatively charged
$(X^-)$ excitons. We identify underlying, characteristic formation pathways of
both few-particle states in the time-domain experiments and show that both
exciton species can be formed either with the optical pump or at later times by
injection of single electrons and holes "surfing" the acoustic wave. All
experimental observations are in excellent agreement with calculated electron
and hole trajectories in the plane of the two-dimensional wetting layer which
is dynamically modulated by the acoustically induced piezoelectric potentials.
Taken together, our findings provide insight on both the onset of
acousto-electric transport of electrons and holes and their conversion into the
optical domain after regulated injection into a single quantum dot emitter.


title:
Constant-temperature level densities in the quasi-continuum of Th and U
  isotopes

abstract:
  Particle-gamma coincidences have been measured to obtain gamma-ray spectra as
a function of excitation energy for 231-233Th and 237-239U. The level
densities, which were extracted using the Oslo method, show a constant
temperature behavior. The isotopes display very similar temperatures in the
quasi-continuum, however, the even-odd isotopes reveal a constant entropy
increase Delta S compared to their even-even neighbors. The entropy excess
depends on available orbitals for the last unpaired valence neutron of the
heated nuclear system. Also, experimental microcanonical temperature and heat
capacity have been extracted. Several poles in the heat capacity curve support
the idea that an almost continuous melting of Cooper pairs is responsible for
the constant-temperature behavior.


title: An effective uniform Artin-Rees lemma

abstract:
  We prove a global uniform Artin-Rees lemma type theorem for sections of ample
line bundles over smooth projective varieties. This result is used to prove an
Artin-Rees lemma for the polynomial ring with uniform degree bounds. The proof
is based on multidimensional residue calculus.


title:
Decoherence effects in the quantum qubit flip game using Markovian
  approximation

abstract:
  We are considering a quantum version of the penny flip game, whose
implementation is influenced by the environment that causes decoherence of the
system. In order to model the decoherence we assume Markovian approximation of
open quantum system dynamics. We focus our attention on the phase damping,
amplitude damping and amplitude raising channels. Our results show that the
Pauli strategy is no longer a Nash equilibrium under decoherence. We attempt to
optimize the players' control pulses in the aforementioned setup to allow them
to achieve higher probability of winning the game compared to the Pauli
strategy.


title: Mixed Inflaton and Spectator Field Models after Planck

abstract:
  We investigate the possibility that the primordial perturbation has two
sources: the inflaton and a spectator field, which is not dynamically important
during inflation but which after inflation can contribute to the curvature
perturbation. The recent Planck results on the power spectrum and
non-Gaussianity allow us to put constraints on such mixed models. In the
generic case, where no specific model for the inflaton or the spectator is
assumed, one finds that in the mixed scenario it is possible to have a large
trispectrum with tau_NL >> (f_NL)^2. The constraints on inflation models in the
plane of the spectral index and tensor-to-scalar ratio are modified by the
presence of a spectator and depend also on the ratio of the
spectator-to-inflaton power R. If one chooses the spectator to be the curvaton
with a quadratic potential, non-Gaussianities can be computed and imply
restrictions on possible values of R. We also consider a mixed curvaton and
chaotic inflation model and show that even quartic chaotic inflation is still
feasible in the context of mixed models.


title: On finite-dimensional attractors of homeomorphisms

abstract:
  Let $E$ be a linear space and suppose that $A$ is the global attractor of
either (i) a homeomorphism $F:E\rightarrow E$ or (ii) a semigroup $S(\cdot)$ on
$E$ that is injective on $A$. In both cases $A$ has trivial shape, and the
dynamics on $A$ can be described by a homeomorphism $F:A\rightarrow A$ (in the
second case we set $F=S(t)$ for some $t>0$). If the topological dimension of
$A$ is finite we show that for any $\epsilon>0$ there is an embedding
$e:A\rightarrow{\mathbb R}^k$, with $k\sim{\rm dim}(A)$, and a (dynamical)
homeomorphism $f:\R^k\rightarrow\R^k$ such that $F$ is conjugate to $f$ on $A$
(i.e.\ $F|_A=e^{-1}\circ f\circ e$) and $f$ has an attractor $A_f$ with
$e(A)\subset A_f\subset N(e(A),\epsilon)$. In other words, we show that the
dynamics on $A$ is essentially finite-dimensional.
  We characterise subsets of ${\mathbb R}^n$ that can be the attractors of
homeomorphisms as cellular sets, give elementary proofs of various topological
results connected to Borsuk's theory of shape and cellularity in Euclidean
spaces, and prove a controlled homeomorphism extension theorem.


title:
Computation of Diet Composition for Patients Suffering from Kidney and
  Urinary Tract Diseases with the Fuzzy Genetic System

abstract:
  Determination of dietary food consumed a day for patients with diseases in
general, greatly affect the health of the body and the healing process, is no
exception for people with kidney disease and urinary tract. This paper presents
the determination of diet composition in the form of food subtance for people
with kidney and urinary tract diseases with a genetic fuzzy approach. This
approach combines fuzzy logic and genetic algorithms, which utilizing fuzzy
logic fuzzy tools and techniques to model the components of the genetic
algorithm and adapting genetic algorithm control parameters, with the aim of
improving system performance. The Mamdani fuzzy inference model and fuzzy rules
based on population parameters and generation are used to determine the
probability of crossover and mutation, and was using In this study, 400 food
survey data along with their substances was used as test material. From the
data, a varying amount of population is established. Each chromosome has 10
genes in which the value of each gene indicates the index number of foodstuffs
in the database. The fuzzy genetic approach produces 10 best food substance and
their compositions. The composition of these foods has nutritional value in
accordance with the number of calories needed by people with kidney and urinary
tract diseases by type of food.


title:
Gender homophily from spatial behavior in a primary school: a
  sociometric study

abstract:
  We investigate gender homophily in the spatial proximity of children (6 to 12
years old) in a French primary school, using time-resolved data on face-to-face
proximity recorded by means of wearable sensors. For strong ties, i.e., for
pairs of children who interact more than a defined threshold, we find
statistical evidence of gender preference that increases with grade. For weak
ties, conversely, gender homophily is negatively correlated with grade for
girls, and positively correlated with grade for boys. This different evolution
with grade of weak and strong ties exposes a contrasted picture of gender
homophily.


title: Local Bubble. Extinction within 55 pc?

abstract:
  In the mapping of the local ISM it is of some interest to know where the
first indications of the boundary of the Local Bubble can be measured. The
Hipparcos distances combined to B-V photometry and some sort of spectral
classification permit mapping of the spatial extinction distribution.
Photometry is available for almost the complete Hipparcos sample and Michigan
Classification is available for brighter stars south of delta = +5 deg (1900).
For the northern and fainter stars spectral types, e.g. the HD types, are given
but a luminosity class is often missing. The B-V photometry and the parallax
do, however, permit a dwarf/giant separation due to the value of the slope of
the reddening vector compared to the gradient of the main sequence in a color
magnitude diagram, in the form: B-V vs. M_V+A_V = V+5(1+log(pi)), together with
the rather shallow extinction present in the Hipparcos sample. We present the
distribution of median A_V(l, b) for stars with Hipparcos 2 distances less than
55 pc. The northern part of the first and second quadrant has most extinction,
up to 0.2 mag and the southern part of the third and fourth quadrant the
slightest extinction, 0.05 mag. The boundary of the extinction minimum appears
rather coherent on an angular resolution of a few degrees


title:
Photoreceptors for a light biotransducer: a comparative study of the
  electrical responses of two (type-1)-opsins

abstract:
  The increasing interest in photoactivated proteins as natural replacement of
standard inorganic materials in photocells drives to the compared analysis of
bacteriorhodopsin and proteorhodopsin, two widely diffused proteins belonging
to the family of \textit{type-1} opsins. These proteins share similar
behaviours but exhibit relevant differences in the sequential chain of the
amino acids constituting their tertiary structure. The use of an impedance
network analogue to model the protein main features provides a microscopic
interpretation of a set of experiments on their photoconductance properties. In
particular, this model links the protein electrical responses to the tertiary
structure and to the interactions among neighbouring amino acids. The same
model is also used to predict the small-signal response in terms of the Nyquist
plot. Interesting enough, these rhodopsins are found to behave like a wide gap
semiconductor with intrinsic conductivities of the order of $10^{-7}$ S/cm.


title:
Bayesian Inference For Exponential Distribution Based On Upper Record
  Range

abstract:
  This paper deals with Bayesian estimations of scale parameter of the
exponential distribution based on upper record range (Rn). This has been done
in two steps; point and interval. In the first step the quadratic, squared
error and absolute error, loss functions have been considered to obtain
Bayesian-point estimations. Also in the next step the shortest Bayes interval
(Hight Posterior Density interval) and Bayes interval with equal tails based on
upper record range have been found. Therefore, the Homotopy Perturbation
Method(HPM) has been applied to obtain the limits of Hight Posterior Density
intervals. Moreover, efforts have been made to meet the admissibility
conditions for linear estimators based on upper record range of the form mRn+d
by obtained Bayesian point estimations. So regarding the consideration of loss
functions, the prior distribution between the conjunction family has been
chosen to be able to produce the linear estimations from upper record range
statistics. Finally, some numerical examples and simulations have been
presented.


title: Relativistic particle in multiscale spacetimes

abstract:
  We study the action and the dynamics of a relativistic particle, uncharged or
charged, in multiscale spacetimes. Invariance under reparametrizations and
Poincar\'e symmetries uniquely determine the action and the line element to be
the usual ones, without the weight factors typical of particle mechanics in
these geometries. The resulting spacetime is multiscale only along spatial
directions. This version of the system is also dictated by recovery of the
nonrelativistic limit together with compatibility with Maxwell and
electrodynamics field theory. Giving up all these requirements and allowing for
a nontrivial weight factor in the time direction produces a modified line
element and considerably complicates the dynamics in the case of a charged
particle.


title: Einstein's "Prague field-equation" -- another perspective

abstract:
  I reconsider Einstein's 1912 "Prague-Theory" of static gravity based on a
scalar field obeying a non-linear field equation. I point out that this
equation follows from the self-consistent implementation of the principle that
all energies source the gravitational field according to E=m(c-squared). This
makes it an interesting toy-model for the "flat-space approach" to General
Relativity, as pioneered by Kraichnan and later Feynman. Solutions modelling
stars show features familiar from GR, e.g., Buchdahl-like inequalities. The
relation to full GR is also discussed. This lends this toy theory also some
pedagogical significance.


title: Geometry of totally real Galois fields of degree 4

abstract:
  We will consider a totally real Galois field $K$ of degree 4 as the linear
coordinate space $\mathbb{Q}^4\subset\mathbb{R}^4$. An element $k\in K$ is
called strictly positive, if all its conjugates are positive. The set of
strictly positive elements is a convex cone in $K$. The convex hull of strictly
positive integral elements is a convex subset of this cone and its boundary
$\Gamma$ is an infinite union of 3-dimensional polyhedrons. The group $U$ of
strictly positive units acts on $\Gamma$: the action of a strictly positive
unit permutes polyhedrons. Fundamental domains of this action are the object of
study in this work. We mainly present some interesting examples.


title:
A new way of setting the phases for cosmological multi-scale Gaussian
  initial conditions

abstract:
  We describe how to define an extremely large discrete realisation of a
Gaussian white noise field that has a hierarchical structure and the property
that the value of any part of the field can be computed quickly. Tiny
subregions of such a field can be used to set the phase information for
Gaussian initial conditions for individual cosmological simulations of
structure formation. This approach has several attractive features: (i) the
hierarchical structure based on an octree is particular well suited for
generating follow up resimulation or zoom initial conditions; (ii) the phases
are defined for all relevant physical scales in advance so that resimulation
initial conditions are, by construction, consistent both with their parent
simulation and with each other; (iii) the field can easily be made public by
releasing a code to compute it - once public, phase information can be shared
or published by specifying a spatial location within the realisation. In this
paper we describe the principles behind creating such realisations. We define
an example called PANPHASIA and in a companion paper on arXiv (Jenkins &
Booth), make public a code to compute it. With fifty octree levels Panphasia
spans a factor of more than 10^15 in linear scale - a range that significantly
exceeds the ratio of the current Hubble radius to the putative CDM
free-streaming scale. We show how to modify a code used for making cosmological
and resimulation initial conditions so that it can take the phase information
from Panphasia and, using this code, we demonstrate that it is possible to make
good quality resimulation initial conditions. We define a convention for
publishing phase information from Panphasia and publish the initial phases for
several of the Virgo Consortium's most recent cosmological simulations
including the 303 billion particle MXXL simulation.


title: On symmetries and conserved quantities in Nambu mechanics

abstract:
  In Hamiltonian mechanics, a (continuous) symmetry leads to conserved
quantity, which is a function on (extended) phase space. In Nambu mechanics, a
straightforward consequence of symmetry is just a relative integral invariant,
a differential form which only upon integration over a cycle provides a
conserved real number. The origin of the difference may be traced back to a
shift in degrees of relevant forms present in equations of motion, or,
alternatively, to a corresponding shift in degrees of relevant objects in
action integral for Nambu mechanics.


title: Locally finite profinite rings

abstract:
  We investigate the structure of locally finite profinite rings. We classify
(Jacobson-) semisimple locally finite profinite rings as products of complete
matrix rings of bounded cardinality over finite fields, and we prove that the
Jacobson radical of any locally finite profinite ring is nil of finite
nilexponent. Our results apply to the context of small compact $G$-rings, where
we also obtain a description of possible actions of $G$ on the underlying ring.


title: Asymptotic solutions in f(R)-gravity

abstract:
  We study cosmological solutions in $R + \beta R^{N}$-gravity for an isotropic
Universe filled with ordinary matter with the equation of state parameter
$\gamma$. Using the Bogolyubov-Krylov-Mitropol'skii averaging method we find
asymptotic oscillatory solutions in terms of new functions, which have been
specially introduced by us for this problem and appeared as a natural
generalization of the usual sine and cosine. It is shown that the late-time
behaviour of the Universe in the model under investigation is determined by the
sign of the difference $\gamma-\gamma_{crit}$ where $\gamma_{crit}=2N/(3N-2)$.
If $\gamma < \gamma_{crit}$, the Universe reaches the regime of small
oscillations near values of Hubble parameter and matter density, corresponding
to General Relativity solution. Otherwise higher-curvature corrections become
important at late times. We also study numerically basins of attraction for the
oscillatory and phantom solutions, which are present in the theory for $N>2$.
Some important differences between $N=2$ and $N>2$ cases are discussed.


title: Communication Steps for Parallel Query Processing

abstract:
  We consider the problem of computing a relational query $q$ on a large input
database of size $n$, using a large number $p$ of servers. The computation is
performed in rounds, and each server can receive only $O(n/p^{1-\varepsilon})$
bits of data, where $\varepsilon \in [0,1]$ is a parameter that controls
replication. We examine how many global communication steps are needed to
compute $q$. We establish both lower and upper bounds, in two settings. For a
single round of communication, we give lower bounds in the strongest possible
model, where arbitrary bits may be exchanged; we show that any algorithm
requires $\varepsilon \geq 1-1/\tau^*$, where $\tau^*$ is the fractional vertex
cover of the hypergraph of $q$. We also give an algorithm that matches the
lower bound for a specific class of databases. For multiple rounds of
communication, we present lower bounds in a model where routing decisions for a
tuple are tuple-based. We show that for the class of tree-like queries there
exists a tradeoff between the number of rounds and the space exponent
$\varepsilon$. The lower bounds for multiple rounds are the first of their
kind. Our results also imply that transitive closure cannot be computed in O(1)
rounds of communication.


title: Is mathematical history written by the victors?

abstract:
  We examine prevailing philosophical and historical views about the origin of
infinitesimal mathematics in light of modern infinitesimal theories, and show
the works of Fermat, Leibniz, Euler, Cauchy and other giants of infinitesimal
mathematics in a new light. We also detail several procedures of the historical
infinitesimal calculus that were only clarified and formalized with the advent
of modern infinitesimals. These procedures include Fermat's adequality;
Leibniz's law of continuity and the transcendental law of homogeneity; Euler's
principle of cancellation and infinite integers with the associated infinite
products; Cauchy's infinitesimal-based definition of continuity and "Dirac"
delta function. Such procedures were interpreted and formalized in Robinson's
framework in terms of concepts like microcontinuity (S-continuity), the
standard part principle, the transfer principle, and hyperfinite products. We
evaluate the critiques of historical and modern infinitesimals by their foes
from Berkeley and Cantor to Bishop and Connes. We analyze the issue of the
consistency, as distinct from the issue of the rigor, of historical
infinitesimals, and contrast the methodologies of Leibniz and Nieuwentijt in
this connection.


title: Dirac quasinormal modes of Chern-Simons and BTZ black holes with torsion

abstract:
  We study Chern-Simons black holes in d-dimensions and we calculate
analytically the quasinormal modes of fermionic perturbations. Also, we
consider as background the five-dimensional Chern-Simons black hole with
torsion and the BTZ black hole with torsion. We have found that the quasinormal
modes depend on the highest power of curvature present in the Chern-Simons
theory, such as occurs for the quasinormal modes of scalar perturbations. We
also show that the effect of the torsion is to modify the real part of the
quasinormal frequencies, which modify the oscillation frequency of the field
for the five dimensional case. However, for the BTZ black hole with torsion,
the effect is to modify the imaginary part of these frequencies, that is, the
relaxation time for the decay of the black hole perturbation. The imaginary
part of the quasinormal frequencies is negative which guaranties the stability
of these black holes under fermionic field perturbations.


title: Bending instability in galactic discs. Advocacy of the linear theory

abstract:
  We demonstrate that in N-body simulations of isolated disc galaxies there is
numerical vertical heating which slowly increases the vertical velocity
dispersion and the disc thickness. Even for models with over a million
particles in a disc, this heating can be significant. Such an effect is just
the same as in numerical experiments by Sellwood (2013). We also show that in a
stellar disc, outside a boxy/peanut bulge, if it presents, the saturation level
of the bending instability is rather close to the value predicted by the linear
theory. We pay attention to the fact that the bending instability develops and
decays very fast, so it couldn't play any role in secular vertical heating.
However the bending instability defines the minimal value of the ratio between
the vertical and radial velocity dispersions $\sigma_z / \sigma_R \approx 0.3$
(so indirectly the minimal thickness) which could have stellar discs in real
galaxies. We demonstrate that observations confirm last statement.


title:
An excision scheme for black holes in constrained evolution
  formulations: spherically symmetric case

abstract:
  Excision techniques are used in order to deal with black holes in numerical
simulations of Einstein equations and consist in removing a topological sphere
containing the physical singularity from the numerical domain, applying instead
appropriate boundary conditions at the excised surface. In this work we present
recent developments of this technique in the case of constrained formulations
of Einstein equations and for spherically symmetric spacetimes. We present a
new set of boundary conditions to apply to the elliptic system in the
fully-constrained formalism of Bonazzola et al. (2004), at an arbitrary
coordinate sphere inside the apparent horizon. Analytical properties of this
system of boundary conditions are studied and, under some assumptions, an
exponential convergence toward the stationary solution is exhibited for the
vacuum spacetime. This is verified in numerical examples, together with the
applicability in the case of the accretion of a scalar field onto a
Schwarzschild black hole. We also present the successful use of the excision
technique in the collapse of a neutron star to a black hole, when excision is
switched on during the simulation, after the formation of the apparent horizon.
This allows the accretion of matter remaining outside the excision surface and
for the stable long-term evolution of the newly formed black hole.


title: Enumeration of octagonal tilings

abstract:
  Random tilings are interesting as idealizations of atomistic models of
quasicrystals and for their connection to problems in combinatorics and
algorithms. Of particular interest is the tiling entropy density, which
measures the relation of the number of distinct tilings to the number of
constituent tiles. Tilings by squares and 45 degree rhombi receive special
attention as presumably the simplest model that has not yet been solved exactly
in the thermodynamic limit. However, an exact enumeration formula can be
evaluated for tilings in finite regions with fixed boundaries. We implement
this algorithm in an efficient manner, enabling the investigation of larger
regions of parameter space than previously were possible. Our new results
appear to yield monotone increasing and decreasing lower and upper bounds on
the fixed boundary entropy density that converge toward S = 0.36021(3).


title:
Afterglow jet breaks, GeV photons and the electromagnetic model of short
  GRBs

abstract:
  We discuss three topics: (i) the dynamics of afterglow jet breaks; (ii) the
origin of Fermi-LAT photons; (iii) the electromagnetic model of short GRBs


title: A Bohr-type model with gravity as the attractive force

abstract:
  We formulate a Bohr-type rotating particle model for three light particles of
the same rest mass, forming a bound rotational state under the influence of
their gravitational attraction, in the same way that electrostatic attraction
leads to the formation of a bound proton-electron state in the classical Bohr
model of the H atom. By using special relativity, the equivalence principle and
the de Broglie wavelength equation, we find that when the three rotating
particles have the rest masses of neutrinos or antineutrinos then surprisingly
the rest mass of the rotating state has the rest mass of the stable baryons,
i.e. of the proton and the neutron. This rest mass is due almost exclusively to
the kinetic energy of the rotating neutrinos. The results are found to be
consistent with the theory of general relativity. Predictions for the
properties of these bound rotational states are compared with experimental
values.


title: Quantum non-Markovian behavior at the chaos border

abstract:
  In this work we study the non-Markovian behaviour of a qubit coupled to an
environment in which the corresponding classical dynamics change from
integrable to chaotic. We show that in the transition region, where the
dynamics has both regular islands and chaotic areas, the average non-Markovian
behaviour is enhanced to values even larger than in the regular regime. This
effect can be related to the non-Markovian behaviour as a function of the the
initial state of the environment, where maxima are attained at the regions
dividing separate areas in classical phase space, particularly at the borders
between chaotic and regular regions. Moreover, we show that the fluctuations of
the fidelity of the environment -- which determine the non-Markovianity measure
-- give a precise image of the classical phase portrait.


title: TLEP, first step in a long-term vision for HEP

abstract:
  The discovery of H(126) has renewed interest in circular e+e- colliders that
can operate as Higgs factories, which benefit from three unique
characteristics: i) high luminosity and reliability, ii) the availability of
several interaction points, iii) superior beam energy accuracy. TLEP is an e+e-
storage ring of 80-km circumference that can operate with very high luminosity
from the Z peak (90 GeV) to the top quark pair threshold (350 GeV). It can
achieve transverse beam polarization at the Z peak and WW threshold, giving it
unparalleled accuracy on the beam energy. A preliminary study indicates that an
80 km tunnel could be constructed around CERN. Such a tunnel would allow a 100
TeV proton-proton collider to be established in the same ring (VHE-LHC),
offering a long term vision.


title:
Activity Modeling in Smart Home using High Utility Pattern Mining over
  Data Streams

abstract:
  Smart home technology is a better choice for the people to care about
security, comfort and power saving as well. It is required to develop
technologies that recognize the Activities of Daily Living (ADLs) of the
residents at home and detect the abnormal behavior in the individual's
patterns. Data mining techniques such as Frequent pattern mining (FPM), High
Utility Pattern (HUP) Mining were used to find those activity patterns from the
collected sensor data. But applying the above technique for Activity
Recognition from the temporal sensor data stream is highly complex and
challenging task. So, a new approach is proposed for activity recognition from
sensor data stream which is achieved by constructing Frequent Pattern Stream
tree (FPS - tree). FPS is a sliding window based approach to discover the
recent activity patterns over time from data streams. The proposed work aims at
identifying the frequent pattern of the user from the sensor data streams which
are later modeled for activity recognition. The proposed FPM algorithm uses a
data structure called Linked Sensor Data Stream (LSDS) for storing the sensor
data stream information which increases the efficiency of frequent pattern
mining algorithm through both space and time. The experimental results show the
efficiency of the proposed algorithm and this FPM is further extended for
applying for power efficiency using HUP to detect the high usage of power
consumption of residents at smart home.


title:
Nonlinear localized modes in PT-symmetric optical media with competing
  gain and loss

abstract:
  The existence and stability of the nonlinear spatial localized modes are
investigated in parity-time symmetric optical media characterized by a generic
complex hyperbolic refractive index distribution with competing gain and loss
profile. The exact analytical expressions of the localized modes are found for
all values of the competing parameter and in the presence of both the
self-focusing and self-defocusing Kerr nonlinearity. The effect of competing
gain/loss profile on the stability structure of these localized modes are
discussed with the help of linear stability analysis followed by the direct
numerical simulation of the governing equation. The spatial localized modes in
two-dimensional geometry as well as the transverse power-flow density
associated with these localized modes are also examined.


title: Multi-Parameter Tikhonov Regularization -- An Augmented Approach

abstract:
  We study multi-parameter regularization (multiple penalties) for solving
linear inverse problems to promote simultaneously distinct features of the
sought-for objects. We revisit a balancing principle for choosing
regularization parameters from the viewpoint of augmented Tikhonov
regularization, and derive a new parameter choice strategy called the
\textit{balanced discrepancy principle}. A priori and a posteriori error
estimates are provided to theoretically justify the principles, and numerical
algorithms for efficiently implementing the principles are also provided.
Numerical results on denoising are presented to illustrate the feasibility of
the balanced discrepancy principle.


title: Discontinuous Shear Thickening of Frictional Hard-Sphere Suspensions

abstract:
  Discontinuous shear thickening (DST) observed in many dense athermal
suspensions has proven difficult to understand and to reproduce by numerical
simulation. By introducing a numerical scheme including both relevant
hydrodynamic interactions and granularlike contacts, we show that contact
friction is essential for having DST. Above a critical volume fraction, we
observe the existence of two states: a low viscosity, contactless (hence,
frictionless) state, and a high viscosity frictional shear jammed state. These
two states are separated by a critical shear stress, associated with a critical
shear rate where DST occurs. The shear jammed state is reminiscent of the
jamming phase of granular matter. Continuous shear thickening is seen as a
lower volume fraction vestige of the jamming transition.


title: Bosonic Mott Insulator with Meissner Currents

abstract:
  We introduce a generic bosonic model exemplifying that (spin) Meissner
currents can persist in insulating phases of matter. We consider two species of
interacting bosons on a lattice. Our model exhibits separation of charge (total
density) and spin (relative density): The charge sector is gapped in a bosonic
Mott insulator phase with total density one, while the spin sector remains
superfluid due to interspecies conversion. Coupling the spin sector to the
gauge fields yields a spin Meissner effect reflecting the long-range spin
superfluid coherence. We investigate the resulting phase diagram and describe
other possible spin phases of matter in the Mott regime possessing chiral
currents as well as a spin-density wave phase. The model presented here is
realizable in Josephson junction arrays and in cold atom experiments.


title:
Hadronic light-by-light scattering in the muon g-2: impact of proposed
  measurements of the (pi^0 -> gamma gamma) decay width and the (gamma^* gamma
  -> pi^0) transition form factor with the KLOE-2 experiment

abstract:
  The calculation of the hadronic light-by-light scattering contribution to the
muon g-2 currently relies entirely on models. Measurements of the form factors
which describe the interactions of hadrons with photons can help to constrain
the models and reduce the uncertainty in a_{mu}(had. LbyL) = (116 \pm 40) x
10^{-11}. In the dominant pion-exchange contribution, the form factor
F_{{pi^0}^*gamma^*gamma^*}((q_1 + q_2)^2, q_1^2, q_2^2) with an off-shell pion
enters. In general, measurements of the transition form factor F(Q^2) =
F_{{pi^0}^*gamma^*gamma^*}(m_{pi}^2, -Q^2, 0) are only sensitive to a subset of
the model parameters. Thus, having a good description for F(Q^2) is only
necessary, not sufficient, to determine a_{mu}(LbyL; pi^0). Simulations have
shown that measurements at KLOE-2 should be able to determine the (pi^0 ->
gamma gamma) decay width to 1% statistical precision and the transition form
factor for small space-like momenta, 0.01 GeV^2 < Q^2 < 0.1 GeV^2, to 6%
precision. In the two-loop integral for the pion-exchange contribution the
relevant regions of momenta are in the range 0 - 1.5 GeV. With the (pi^0 ->
gamma gamma) decay width from the PDG [PrimEx] and current data for the
transition form factor, the error on a_{mu}(LbyL; pi^0) is (\pm 4 x 10^{-11})
[\pm 2 x 10^{-11}], not taking into account the uncertainty related to the
off-shellness of the pion. Including the simulated KLOE-2 data reduces the
error to (\pm (0.7 - 1.1) x 10^{-11}). For models like VMD, which have only few
parameters that are completely determined by measurements of F(Q^2), this
represents the total error. But maybe such models are too simplistic. In other
models, e.g. those based on large-N_c QCD, parameters describing the off-shell
pion dominate the uncertainty in a_{mu; large-N_c}(LbyL; pi^0) = (72 \pm 12) x
10^{-11}.


title: Micromagnetic approach to exchange bias---A new look at an old problem

abstract:
  We present a micromagnetic approach to exchange bias (EB) in ferromagnetic
(FM)/antiferromagnetic (AFM) thin film systems with a small number of
irreversible interfacial magnetic moments. We express the exchange bias field
$H_{EB}$ in terms of fundamental micromagnetic length scale---the exchange
length $l_{ex}$. The benefit from this approach is a better separation of a
term related to FM layer from a term related to FM/AFM coupling at interfaces.
Using this approach we estimate the highest limit of $H_{EB}$ in real FM/AFM
systems.


title: The Powers of 9 and Related Mathematical Tables from Babylon

abstract:
  Late-Babylonian mathematics (450-100 BC), represented by some 60 cuneiform
tablets from Babylon and Uruk, is incompletely known compared to its abundantly
preserved, well-studied Old-Babylonian predecessor (1800-1600 BC). With the
present paper, 16 fragments from Babylon, probably belonging to 13 different
tablets, are added to this corpus. Two remarkable tablets represent a hitherto
unknown class of very large factorization tables that can be adequately
described as Babylonian examples of number crunching (Section I). In these
tables a very large sexagesimal number representing a small factor (9 or 12)
raised to a high power, or a product of such numbers, is repeatedly divided by
its constituent factors (9 or 12), very likely until 1 is reached. In Text A
the initial number is a 25-digit number equivalent to 9 to the power 46; in
Text B it is a 30-digit number equivalent to 9 to the power 11 times 12 to the
power 39 - the longest number attested in ancient Mesopotamia and, probably, in
all antiquity. Most other fragments belong to tables with reciprocals (Section
II) and squares (Section III). Finally, two fragments contain multiplications
of one kind or another (Section IV).


title:
Universality classes and crossover scaling of Barkhausen noise in thin
  films

abstract:
  We study the dynamics of head-to-head domain walls separating in-plane
domains in a disordered ferromagnetic thin film. The competition between the
domain wall surface tension and dipolar interactions induces a crossover
between a rough domain wall phase at short length-scales and a large-scale
phase where the walls display a zigzag morphology. The two phases are
characterized by different critical exponents for Barkhausen avalanche dynamics
that are in quantitative agreement with experimental measurements on MnAs thin
films.


title:
Comparison of Neural Network and Hadronic Model Predictions of
  Two-Photon Exchange Effect

abstract:
  Predictions for the two-photon exchange (TPE) correction to unpolarized $ep$
elastic cross section, obtained within two different approaches, are confronted
and discussed in detail. In the first one the TPE correction is extracted from
experimental data by applying the Bayesian neural network (BNN) statistical
framework. In the other the TPE is given by box diagrams, with the nucleon and
the $P_{33}$ resonance as the hadronic intermediate states. Two different form
factor parametrizations for both the proton and the $P_{33}$ resonance are
taken into consideration. Proton form factors are obtained from the global fit
of the full model (with the TPE correction) to the unpolarized cross section
data. Predictions of both methods agree well in the intermediate $Q^2$ range,
$(1,3)$ GeV$^2$. Above $Q^2=3$ GeV$^2$ the agreement is on $2\sigma$ level.
Below $Q^2=1$ GeV$^2$ the consistency between both approaches is broken. The
values of the proton radius extracted within both models are given. In both
cases predictions for VEPP-3 experiment have been obtained and confronted with
the preliminary experimental results.


title:
Interpolatability distinguishes LOCC from separable von Neumann
  measurements

abstract:
  Local operations with classical communication (LOCC) and separable operations
are two classes of quantum operations that play key roles in the study of
quantum entanglement. Separable operations are strictly more powerful than
LOCC, but no simple explanation of this phenomenon is known. We show that, in
the case of von Neumann measurements, the ability to interpolate measurements
is an operational principle that sets apart LOCC and separable operations.


title:
Frequency-Domain Stochastic Modeling of Stationary Bivariate or
  Complex-Valued Signals

abstract:
  There are three equivalent ways of representing two jointly observed
real-valued signals: as a bivariate vector signal, as a single complex-valued
signal, or as two analytic signals known as the rotary components. Each
representation has unique advantages depending on the system of interest and
the application goals. In this paper we provide a joint framework for all three
representations in the context of frequency-domain stochastic modeling. This
framework allows us to extend many established statistical procedures for
bivariate vector time series to complex-valued and rotary representations.
These include procedures for parametrically modeling signal coherence,
estimating model parameters using the Whittle likelihood, performing
semi-parametric modeling, and choosing between classes of nested models using
model choice. We also provide a new method of testing for impropriety in
complex-valued signals, which tests for noncircular or anisotropic second-order
statistical structure when the signal is represented in the complex plane.
Finally, we demonstrate the usefulness of our methodology in capturing the
anisotropic structure of signals observed from fluid dynamic simulations of
turbulence.


title: Examples of N=2 to N=1 supersymmetry breaking

abstract:
  In this paper we consider gauged N=2 supergravities which arise in the
low-energy limit of type II string theories and study examples which exhibit
spontaneous partial supersymmetry breaking. For the quantum STU model we derive
the scalar field space and the scalar potential of the N=1 supersymmetric
low-energy effective action. We also study the properties of the Minkowskian
N=1 supersymmetricground states for a broader class of supergravities including
the quantum STU model.


title:
Bayesian nonparametric disclosure risk estimation via mixed effects
  log-linear models

abstract:
  Statistical agencies and other institutions collect data under the promise to
protect the confidentiality of respondents. When releasing microdata samples,
the risk that records can be identified must be assessed. To this aim, a widely
adopted approach is to isolate categorical variables key to the identification
and analyze multi-way contingency tables of such variables. Common disclosure
risk measures focus on sample unique cells in these tables and adopt parametric
log-linear models as the standard statistical tools for the problem. Such
models often have to deal with large and extremely sparse tables that pose a
number of challenges to risk estimation. This paper proposes to overcome these
problems by studying nonparametric alternatives based on Dirichlet process
random effects. The main finding is that the inclusion of such random effects
allows us to reduce considerably the number of fixed effects required to
achieve reliable risk estimates. This is studied on applications to real data,
suggesting, in particular, that our mixed models with main effects only produce
roughly equivalent estimates compared to the all two-way interactions models,
and are effective in defusing potential shortcomings of traditional log-linear
models. This paper adopts a fully Bayesian approach that accounts for all
sources of uncertainty, including that about the population frequencies, and
supplies unconditional (posterior) variances and credible intervals.


title: Random Walks in Cones: the Case of Nonzero Drift

abstract:
  We consider multidimensional discrete valued random walks with nonzero drift
killed when leaving general cones of the euclidian space. We find the
asymptotics for the exit time from the cone and study weak convergence of the
process conditioned on not leaving the cone. We get quasistationarity of its
limiting distribution. Finally we construct a version of the random walk
conditioned to never leave the cone.


title:
Initial Friedmann universe, its spatial flatness, matter creation, and
  the cosmological term

abstract:
  In the Friedmann equations, an infinite initial density is avoided only when
the universe is spatially flat. With such equations being then valid when the
scale factor $a=0$, the universe must also be in the state of vacuum when $a$
is infinitesimal. Matter creation thus largely comes from nonlinearity of the
Friedmann equations at a finite $a$. For the correspondence between such an
initial vacuum and the Friedmann universe, therefore, a vacuum density is
suggested to be gravitationally significant only when it could also have a
matter phase. The effective cosmological term is then due to such a vacuum
density.


title: DNA Reservoir Computing: A Novel Molecular Computing Approach

abstract:
  We propose a novel molecular computing approach based on reservoir computing.
In reservoir computing, a dynamical core, called a reservoir, is perturbed with
an external input signal while a readout layer maps the reservoir dynamics to a
target output. Computation takes place as a transformation from the input space
to a high-dimensional spatiotemporal feature space created by the transient
dynamics of the reservoir. The readout layer then combines these features to
produce the target output. We show that coupled deoxyribozyme oscillators can
act as the reservoir. We show that despite using only three coupled
oscillators, a molecular reservoir computer could achieve 90% accuracy on a
benchmark temporal problem.

categories: cs.NE cs.ET nlin.AO nlin.CD physics.bio-ph


title:
The Effect of Hydrogen Adsorption on the Magnetic Properties of a
  Surface Nanocluster of Iron

abstract:
  The effect of hydrogen adsorption on the magnetic properties of an Fe$_3$
cluster immersed in a Cu(111) surface has been calculated using densifty
functional theory and the results used to parametrize an Alexander-Anderson
model which takes into account the interaction of d-electrons with itinerant
electrons. A number of adatom configurations containing one to seven H-atoms
were analyzed. The sequential addition of hydrogen atoms is found to
monotonically reduce the total magnetic moment of the cluster with the effect
being strongest when the H-atoms sit at low coordinated sites. Decomposition of
the charge density indicates a transfer of 0.4 electrons to each of the H-atoms
from both the Fe-atoms and from the copper substrate, irrespective of
adsorption site and coverage. The magnetic moment of only the nearest neighbor
Fe-atoms is reduced and mainly due to increased population of minority spin
d-states. This can be modeled by increased indirect coupling of d-states via
the conduction s-band in the Alexander-Anderson model.


title: Thermomechanical design of a static gas target for electron accelerators

abstract:
  Gas targets are often used at accelerator facilities. A design of
high-pressure gas cells that are suitable for hydrogen and helium isotopes at
relatively high electron beam currents is presented. In particular, we consider
rare gas targets, $^3$H$_2$ and $^3$He. In the design, heat transfer and
mechanical integrity of the target cell are emphasized. ANSYS 12 was used for
the thermo-mechanical studies of the target cell. Since the ultimate goal in
this study was to design a gas target for use at the Jefferson Laboratory
(JLab), particular attention is given to the typical operating conditions found
there. It is demonstrated that an aluminum alloy cell can meet the required
design goals.


title: Measurement of ortho-Positronium Properties in Liquid Scintillators

abstract:
  Pulse shape discrimination in liquid scintillator detectors is a
well-established technique for the discrimination of heavy particles from light
particles. Nonetheless, it is not efficient in the separation of electrons and
positrons, as they give rise to indistinguishable scintillator responses. This
inefficiency can be overtaken through the exploitation of the formation of
ortho-Positronium (o-Ps), which alters the time profile of light pulses induced
by positrons.
  We characterized the o-Ps properties in the most commonly used liquid
scintillators, i.e. PC, PXE, LAB, OIL and PC + PPO. In addition, we studied the
effects of scintillator doping on the o-Ps properties for dopants currently
used in neutrino experiments, Gd and Nd. Further measurements for Li-loaded and
Tl-loaded liquid scintillators are foreseen. We found that the o-Ps properties
are suitable for enhancing the electron-positron discrimination.


title: An operational link between MUBs and SICs

abstract:
  We exhibit an operational connection between mutually unbiased bases and
symmetric infomationally complete positive operator-valued measures. Assuming
that the latter exists, we show that there is a strong link between these two
structures in all prime power dimensions. We also demonstrate that a similar
link cannot exists in dimension 6.


title: The Gale-Berlekamp game for Hadamard matrices

abstract:
  Given an Hadamard matrix $H\in M_N(\pm1)$ we consider the function
$\varphi:\mathbb Z_2^N\times\mathbb Z_2^N\to\mathbb Z$ given by
$\varphi(a,b)=\sum_{ij}a_ib_jH_{ij}$, which sums the entries of the various
conjugates of $H$, obtained by switching signs on rows and columns. Our claim
is that $\varphi$, or just its probabilistic distribution $\mu\in\mathcal
P(\mathbb Z)$, that we call "glow" of the matrix, should encode important
information about $H$. We present here a number of results and conjectures in
this direction, notably with a general decomposition result for $\mu$.


title:
A logical treatment of special relativity, with and without
  faster-than-light observers

abstract:
  There are three goals of this thesis. First: to present a concise yet
accessible description of basic mathematical logic and model theory. Second: to
develop an axiomatization of special relativity using only two undefined
predicates. Ideally, these axioms should be empirically verifiable and
supported by a large body of evidence. Finally: to weaken this axiomatization
so as to allow for the existence of faster-than-light observers, which are
normally excluded from the theory of special relativity. The modifications to
the axiom system should be as slight as possible, and should be motivated by
the question: what features of the original axiom system preclude the existence
of faster-than-light observers?


title:
Lagrange-Poincar\'e reduction for optimal control of underactuated
  mechanical systems

abstract:
  We deal with regular Lagrangian constrained systems which are invariant under
the action of a symmetry group. Fixing a connection on the higher-order
principal bundle where the Lagrangian and the (independent) constraints are
defined, the higher-order Lagrange-Poincar\'e equations of classical mechanical
systems with higher-order constraints are obtained from classical Lagrangian
reduction. Higher-order Lagrange-Poincar\'e operator is introduced to
characterize higher-order Lagrange-Poincar\'e equations. Interesting
applications are derived as, for instance, the optimal control of an
underactuated Elroy's Beanie and a snakeboard seens as an optimization problem
with higher-order constraints.


title:
Integral Equations for Computing AC Losses of Radially and Polygonally
  Arranged HTS Thin Tapes

abstract:
  In this paper we derive the integral equations for radially and polygonally
arranged high-temperature superconductor thin tapes and we solve them by
finite-element method. The superconductor is modeled with a non-linear power
law, which allows the possibility of considering the dependence of the
parameters on the magnetic field or the position. The ac losses are computed
for a variety of geometrical configurations and for various values of the
transport current. Differences with respect to existing analytical models,
which are developed in the framework of the critical state model and only for
certain values of the transport current, are pointed out.


title:
The Effects of Variations in Nuclear Interactions on Nucleosynthesis in
  Thermonuclear Supernovae

abstract:
  The impact of nuclear physics uncertainties on nucleosynthesis in
thermonuclear supernovae has not been fully explored using comprehensive and
systematic studies with multiple models. To better constrain predictions of
yields from these phenomena, we have performed a sensitivity study by
post-processing thermodynamic histories from two different hydrodynamic,
Chandrasekhar-mass explosion models. We have individually varied all input
reaction and, for the first time, weak interaction rates by a factor of ten and
compared the yields in each case to yields using standard rates. Of the 2305
nuclear reactions in our network, we find that the rates of only 53 reactions
affect the yield of any species with an abundance of at least 10^-8 M_sun by at
least a factor of two, in either model. The rates of the 12C(a,g), 12C+12C,
20Ne(a,p), 20Ne(a,g) and 30Si(p,g) reactions are among those that modify the
most yields when varied by a factor of ten. From the individual variation of
658 weak interaction rates in our network by a factor of ten, only the stellar
28Si(b+)28Al, 32S(b+)32P and 36Ar(b+)36Cl rates significantly affect the yields
of species in a model. Additional tests reveal that reaction rate changes over
temperatures T > 1.5 GK have the greatest impact, and that ratios of
radionuclides that may be used as explosion diagnostics change by a factor of
less than two from the variation of individual rates by a factor of 10.
Nucleosynthesis in the two adopted models is relatively robust to variations in
individual nuclear reaction and weak interaction rates. Laboratory measurements
of a limited number of reactions would help to further constrain predictions.
As well, we confirm the need for a consistent treatment for relevant stellar
weak interaction rates since simultaneous variation of these rates (as opposed
to individual variation) has a significant effect on yields in our models.


title: Rank two aCM bundles on the del Pezzo threefold with Picard number 3

abstract:
  Let k be an algebraically closed field of characteristic 0. A del Pezzo
threefold F with maximal Picard number is isomorphic to P^1xP^1xP^1, where P^1
is the projective line over k. In the present paper we completely classify
locally free sheaves of rank 2 with vanishing intermediate cohomology over such
an F. Such a classification extends similar results proved by E. Arrondo and L.
Costa regarding del Pezzo threefolds with Picard number 1.


title: Commutative Quaternion Matrices

abstract:
  In this study, we introduce the concept of commutative quaternions and
commutative quaternion matrices. Firstly, we give some properties of
commutative quaternions and their Hamilton matrices. After that we investigate
commutative quaternion matrices using properties of complex matrices. Then we
define the complex adjoint matrix of commutative quaternion matrices and give
some of their properties.


title:
Association between Experiences and Representations: Memory, Dreaming,
  Dementia and Consciousness

abstract:
  The mechanisms underlying major aspects of the human brain remain a mystery.
It is unknown how verbal episodic memory is formed and integrated with sensory
episodic memory. There is no consensus on the function and nature of dreaming.
Here we present a theory for governing neural activity in the human brain. The
theory describes the mechanisms for building memory traces for entities and
explains how verbal memory is integrated with sensory memory. We infer that a
core function of dreaming is to move charged particles such as calcium ions
from the hippocampus to association areas to primary areas. We link a high
level of calcium ions concentrations to Alzheimer's disease. We present a more
precise definition of consciousness. Our results are a step forward in
understanding the function and health of the human brain and provide the public
with ways to keep a healthy brain.


title:
Atmospheric Parameters of 169 F, G, K and M-type Stars in the Kepler
  Field

abstract:
  The asteroseismic and planetary studies, like all research related to stars,
need precise and accurate stellar atmospheric parameters as input. We aim at
deriving the effective temperature (Teff), the surface gravity (log g), the
metallicity ([Fe/H]), the projected rotational velocity (v sin i) and the MK
type for 169 F, G, K, and M-type Kepler targets which were observed
spectroscopically from the ground with five different instruments. We use two
different spectroscopic methods to analyse 189 high-resolution,
high-signal-to-noise spectra acquired for the 169 stars. For 67 stars, the
spectroscopic atmospheric parameters are derived for the first time. KIC
9693187 and 11179629 are discovered to be double-lined spectroscopic binary
systems. The results obtained for those stars for which independent
determinations of the atmospheric parameters are available in the literature
are used for a comparative analysis. As a result, we show that for solar-type
stars the accuracy of present determinations of atmospheric parameters is +/-
150 K in Teff, +/- 0.15 dex in [Fe/H], and +/-? 0.3 dex in log g. Finally, we
confirm that the curve-of-growth analysis and the method of spectral synthesis
yield systematically different atmospheric parameters when they are applied to
stars hotter than 6,000 K.


title:
Igusa's p-adic local zeta function and the Monodromy Conjecture for
  non-degenerated surface singularities

abstract:
  In 2011 Lemahieu and Van Proeyen proved the Monodromy Conjecture for the
local topological zeta function of a non-degenerated surface singularity. We
start from their work and obtain the same result for Igusa's p-adic and the
motivic zeta function. In the p-adic case, this is, for a polynomial f in
Z[x,y,z] satisfying f(0,0,0)=0 and non-degenerated with respect to its Newton
polyhedron, we show that every pole of the local p-adic zeta function of f
induces an eigenvalue of the local monodromy of f at some point of the complex
zero locus of f close to the origin.
  Essentially the entire paper is dedicated to proving that, for f as above,
certain candidate poles of Igusa's p-adic zeta function of f, arising from
so-called B_1-facets of the Newton polyhedron of f, are actually not poles.
This turns out to be much harder than in the topological setting. The
combinatorial proof is preceded by a study of the integral points in
three-dimensional fundamental parallelepipeds. Together with the work of
Lemahieu and Van Proeyen, this main result leads to the Monodromy Conjecture
for the p-adic and motivic zeta function of a non-degenerated surface
singularity.


title: Quantum geometry with a nondegenerate vacuum: a toy model

abstract:
  Motivated by a recent proposal (by Koslowski-Sahlmann) of a kinematical
representation in Loop Quantum Gravity (LQG) with a nondegenerate vacuum
metric, we construct a polymer quantization of the parametrised massless scalar
field theory on a Minkowskian cylinder. The dif- feomorphism covariant
kinematics is based on states which carry a continuous label corresponding to
smooth embedding geometries, in addition to the discrete embedding and matter
labels. The physical state space, obtained through group averaging procedure,
is nonseparable. A physical state in this theory can be interpreted as a
quantum spacetime, which is composed of discrete strips and supercedes the
classical continuum. We find that the conformal group is broken in the quantum
theory, and consists of all Poincare translations. These features are
remarkably different compared to the case without a smooth embedding. Finally,
we analyse the length operator whose spectrum is shown to be a sum of
contributions from the continuous and discrete embedding geometries, being in
perfect analogy with the spectra of geometrical operators in LQG with a
nondegenerate vacuum geometry.


title:
3- and 4-Body Final States in B, D and tau Decays about Features of New
  Dynamics with CPT Invariance or "Achaeans outside Troy"

abstract:
  The 'landscape' of fundamental dynamics has changed even for the 'known'
matter. The Standard Model has produced at least the leading source of CP
violation (CPV) in B decays; the data have not shown CP asymmetries in $D$
transitions. It needs more data and better technologies to understand the
underlying forces. Probing three- and four-body final states in $B$ & $D$ &
$\tau$ decays with better accuracy is crucial about the existence and the
features of New Dynamics. Theoretical tools produced about MEP will show even
more about HEP in the future. We have to work on the {\em correlations} between
different final states on several CKM levels and the connection between known
matter and Dark Matter in indirect ways. CPT invariance is usable in $D$ and
$\tau$ decays.


title: Koroljuk's formula for counting lattice paths revisited

abstract:
  Koroljuk gave a summation formula for counting the number of lattice paths
from $(0,0)$ to $(m,n)$ with $(1,0), (0,1)$-steps in the plane that stay
strictly above the line $y=k(x-d)$, where $k$ and $d$ are positive integers. In
this paper we obtain an explicit formula for the number of lattice paths from
$(a,b)$ to $(m,n)$ above the diagonal $y=kx-r$, where $r$ is a rational number.
Our result slightly generalizes Koroljuk's formula, while the former can be
essentially derived from the latter. However, our proof uses a recurrence with
respect to the starting points, and hereby presents a new approach to
Koroljuk's formula.


title: Triaxial Cosmological Haloes and the Disc of Satellites

abstract:
  We construct simple triaxial generalisations of Navarro-Frenk-White haloes.
The models have elementary gravitational potentials, together with a density
that is cusped like 1/r at small radii and falls off like 1/r^3 at large radii.
The ellipticity varies with radius in a manner that can be tailored to the
user's specification. The closed periodic orbits in the planes perpendicular to
the short and long axes of the model are well-described by epicyclic theory,
and can be used as building blocks for long-lived discs. As an application, we
carry out the simulations of thin discs of satellites in triaxial dark halo
potentials. This is motivated by the recent claims of an extended, thin disc of
satellites around the M31 galaxy with a vertical rms scatter of ~12 kpc and a
radial extent of ~ 300 kpc (Ibata et al. 2013). We show that a thin satellite
disc can persist over cosmological times if and only if it lies in the planes
perpendicular to the long or short axis of a triaxial halo, or in the
equatorial or polar planes of a spheroidal halo. In any other orientation, then
the disc thickness doubles on ~5 Gyr timescales and so must have been born with
an implausibly small vertical scaleheight.


title: Relaying Strategies for Uplink in Wireless Cellular Networks

abstract:
  In this paper, we analyze the impact of relays on the uplink performance of
FDMA cellular networks. We focus our analysis on Decode and Forward techniques,
with the aim of measuring the improvements which can be achieved in terms of
throughput and energy saving. We apply a stochastic geometry based approach to
a scenario with inter-cell interference and reuse factor equal to 1. The first
goal of this work is to observe what is the impact of various relay features,
such as transmission power, location and antenna pattern, when a half-duplex
constraint is imposed. The second goal is to determine how much relaying can be
beneficial also for users who are not at the cell edge, and who can therefore
use a direct link towards the base station. We show that if more refined
decoding techniques, such as Successive Interference Cancellation and
Superposition Coding, are properly used, considerable gains can be obtained for
these mobiles as well.


abstract:
  We study vector-valued Siegel modular forms of genus 2 and level 2. We
describe the structure of certain modules of vector-valued modular forms over
rings of scalar-valued modular forms.


title: Wilson line approach to gravity in the high energy limit

abstract:
  We examine the high energy (Regge) limit of gravitational scattering using a
Wilson line approach previously used in the context of non-Abelian gauge
theories. Our aim is to clarify the nature of the Reggeization of the graviton
and the interplay between this Reggeization and the so-called eikonal phase
which determines the spectrum of gravitational bound states. Furthermore, we
discuss finite corrections to this picture. Our results are of relevance to
various supergravity theories, and also help to clarify the relationship
between gauge and gravity theories.


title: Collision and Preimage Resistance of the Centera Content Address

abstract:
  Centera uses cryptographic hash functions as a means of addressing stored
objects, thus creating a new class of data storage referred to as CAS (content
addressed storage). Such hashing serves the useful function of providing a
means of uniquely identifying data and providing a global handle to that data,
referred to as the Content Address or CA. However, such a model begs the
question: how certain can one be that a given CA is indeed unique?
  In this paper we describe fundamental concepts of cryptographic hash
functions, such as collision resistance, pre-image resistance, and
second-preimage resistance. We then map these properties to the MD5 and SHA-256
hash algorithms, which are used to generate the Centera content address.
Finally, we present a proof of the collision resistance of the Centera Content
Address.


title: Chaos in the Kepler problem with quadrupole perturbations

abstract:
  We use the Melnikov integral method to prove that the Hamiltonian flow on the
zero-energy manifold for the Kepler problem perturbed by a quadrupole moment is
chaotic, irrespective of the perturbation being of prolate or oblate type. This
result helps to elucidate some recent conflicting works in the physical
literature based on numerical simulations.


title: Polyakov loop potential at finite density

abstract:
  The Polyakov loop potential serves to distinguish between the confined
hadronic and the deconfined quark-gluon plasma phases of QCD. For Nf=2+1 quark
flavors with physical masses we determine the Polyakov loop potential at finite
temperature and density and extract the location of the deconfinement
transition. We find a cross-over at small values of the chemical potential
running into a critical end-point at mu/T > 1.


title: A Simulator for Data-Intensive Job Scheduling

abstract:
  Despite the fact that size-based schedulers can give excellent results in
terms of both average response times and fairness, data-intensive computing
execution engines generally do not employ size-based schedulers, mainly because
of the fact that job size is not known a priori.
  In this work, we perform a simulation-based analysis of the performance of
size-based schedulers when they are employed with the workload of typical
data-intensive schedules and with approximated size estimations. We show
results that are very promising: even when size estimation is very imprecise,
response times of size-based schedulers can be definitely smaller than those of
simple scheduling techniques such as processor sharing or FIFO.


title: Ground-state entanglement in coupled qubits

abstract:
  We study a system of qubits that are coupled to each other via only one
degree of freedom represented, e.g., by $\sigma_z$-operators. We prove that, if
by changing the Hamiltonian parameters, a non-degenerate ground state of the
system is continuously transformed in such a way that the expectation values of
$\sigma_z$ operators of at least two coupled qubits change, this ground state
is entangled. Using this proof, we discuss connection between energy level
anticrossings and ground state entanglement. Following the same line of
thought, we introduce entanglement witnesses, based on cross-susceptibilities,
that can detect ground state entanglement for any bipartition of the
multi-qubit system. A witness for global ground state entanglement is also
introduced.


title: Coxeter groups, hyperbolic cubes, and acute triangulations

abstract:
  Let $C(L)$ be the right-angled Coxeter group defined by an abstract
triangulation $L$ of $\mathbb{S}^2$. We show that $C(L)$ is isomorphic to a
hyperbolic right-angled reflection group if and only if $L$ can be realized as
an acute triangulation. The proof relies on the theory of CAT(-1) spaces. A
corollary is that an abstract triangulation of $\mathbb{S}^2$ can be realized
as an acute triangulation exactly when it satisfies a combinatorial condition
called "flag no-square". We also study generalizations of this result to other
angle bounds, other planar surfaces and other dimensions.


title:
Simultaneous identification of diffusion and absorption coefficients in
  a quasilinear elliptic problem

abstract:
  In this work we consider the identifiability of two coefficients $a(u)$ and
$c(x)$ in a quasilinear elliptic partial differential equation from observation
of the Dirichlet-to-Neumann map. We use a linearization procedure due to Isakov
[On uniqueness in inverse problems for semilinear parabolic equations. Archive
for Rational Mechanics and Analysis, 1993] and special singular solutions to
first determine $a(0)$ and $c(x)$ for $x \in \Omega$. Based on this partial
result, we are then able to determine $a(u)$ for $u \in \mathbb{R}$ by an
adjoint approach.


title:
Recoil Properties of Fragments Formed in the 4.4 GeV Deuteron-Induced
  Reaction on Gold target

abstract:
  The recoil properties of fragments produced by the interaction of 4.4 GeV
deuteron with 197Au target have been studied. New experimental data on recoil
properties for 90 nuclei, varying from 24Na to 198Au, were obtained. The
technique applied was the {thick-target thick-catcher} and induced activity
method. The deuteron beam was obtained from the Nuclotron of the Laboratory of
High Energies (LHE), Joint Institute for Nuclear Research (JINR), Dubna. The
experimental data were analyzed on the basis of the standard two-step vector
model formalism. From this analysis we could find evidence to support the
existence of several different mechanisms, such as spallation, fission and
fragmentation, in the reaction investigated. Fission contributed appreciably to
the formation of products in the mass region of 65 < A < 120. The kinematic
characteristics of residual nuclei formed in the present deuteron-induced
reaction have been compared to those from proton-induced reactions with gold
target.


title:
Adaptive MC^3 and Gibbs algorithms for Bayesian Model Averaging in
  Linear Regression Models

abstract:
  The MC$^3$ (Madigan and York, 1995) and Gibbs (George and McCulloch, 1997)
samplers are the most widely implemented algorithms for Bayesian Model
Averaging (BMA) in linear regression models. These samplers draw a variable at
random in each iteration using uniform selection probabilities and then propose
to update that variable. This may be computationally inefficient if the number
of variables is large and many variables are redundant. In this work, we
introduce adaptive versions of these samplers that retain their simplicity in
implementation and reduce the selection probabilities of the many redundant
variables. The improvements in efficiency for the adaptive samplers are
illustrated in real and simulated datasets.


title: AstraKahn: A Coordination Language for Streaming Networks

abstract:
  This is a preliminary version of the language report. It contains key
definitions, specifications and some examples, but lacks completeness. The full
document will include Chapter 3 (Data and Instrumentation Layer) and will
comprise an appendix giving the complete syntax and some whole program
examples. The purpose of the present document is to fix the concepts and major
features of the language and to enable the production of the definition
document that is required for implementation.


title: Dynamical invariants for group automorphisms

abstract:
  We discuss some of the issues that arise in attempts to classify
automorphisms of compact abelian groups from a dynamical point of view. In the
particular case of automorphisms of one-dimensional solenoids, a complete
description is given and the problem of determining the range of certain
invariants of topological conjugacy is discussed. Several new results and old
and new open problems are described.


title: Iterated Chvatal-Gomory Cuts and the Geometry of Numbers

abstract:
  Chvatal-Gomory cutting planes (CG-cuts for short) are a fundamental tool in
Integer Programming. Given any single CG-cut, one can derive an entire family
of CG-cuts, by `iterating' its multiplier vector modulo one. This leads
naturally to two questions: first, which iterates correspond to the strongest
cuts, and, second, can we find such strong cuts efficiently? We answer the
first question empirically, by showing that one specific approach for selecting
the iterate tends to perform much better than several others. The approach
essentially consists in solving a nonlinear optimization problem over a special
lattice associated with the CG-cut. We then provide a partial answer to the
second question, by presenting a polynomial-time algorithm that yields an
iterate that is strong in a certain well-defined sense. The algorithm is based
on results from the algorithmic geometry of numbers.


title:
Complete and Easy Bidirectional Typechecking for Higher-Rank
  Polymorphism

abstract:
  Bidirectional typechecking, in which terms either synthesize a type or are
checked against a known type, has become popular for its scalability (unlike
Damas-Milner type inference, bidirectional typing remains decidable even for
very expressive type systems), its error reporting, and its relative ease of
implementation. Following design principles from proof theory, bidirectional
typing can be applied to many type constructs. The principles underlying a
bidirectional approach to polymorphism, however, are less obvious. We give a
declarative, bidirectional account of higher-rank polymorphism, grounded in
proof theory; this calculus enjoys many properties such as eta-reduction and
predictability of annotations. We give an algorithm for implementing the
declarative system; our algorithm is remarkably simple and well-behaved,
despite being both sound and complete.


title: The Large-$N$ Limits of Brownian Motions on $\mathbb{GL}_N$

abstract:
  We introduce a two-parameter family of diffusion processes
$(B_{r,s}^N(t))_{t\ge 0}$, $r,s>0$, on the general linear group $\mathbb{GL}_N$
that are Brownian motions with respect to certain natural metrics on the group.
At the same time, we introduce a two-parameter family of free It\^o processes
$(b_{r,s}(t))_{t\ge 0}$ in a faithful, tracial $W^\ast$-probability space, and
we prove that the full process $(B^N_{r,s}(t))_{t\ge 0}$ converges to
$(b_{r,s}(t))_{t\ge 0}$ in noncommutative distribution as $N\to\infty$ for each
$r,s>0$. The processes $(b_{r,s}(t))_{t\ge 0}$ interpolate between the free
unitary Brownian motion when $(r,s)=(1,0)$, and the free multiplicative
Brownian motion when $r=s=\frac12$; we thus resolve the open problem of
convergence of the Brownian motion on $\mathbb{GL}_N$ posed by Biane in 1997.


title: Has a thick neutron skin in ${}^{208}$Pb been ruled out?

abstract:
  The Lead Radius Experiment (PREX) has provided the first model-independent
evidence in favor of a neutron-rich skin in ${}^{208}$Pb. Although the error
bars are large, the reported large central value of 0.33\,fm is particularly
intriguing. To test whether such a thick neutron-skin in ${}^{208}$Pb is
already incompatible with laboratory experiments or astrophysical observations,
we employ relativistic models with neutron-skin thickness in ${}^{208}$Pb
ranging from 0.16 to 0.33 fm to compute ground state properties of finite
nuclei, their collective monopole and dipole response, and mass-{\sl vs}-radius
relations for neutron stars. No compelling reason was found to rule out models
with large neutron skins in ${}^{208}$Pb from the set of observables considered
in this work.


title: Several remarks on groups of automorphisms of free groups

abstract:
  Let $G$ be the group of automorphisms of a free group $F_\infty$ of infinite
order. Let $H$ be the stabilizer of first $m$ generators of $F_\infty$. We show
that the double cosets of $\Gamma$ with respect to $H$ admit a natural
semigroup structure. For any compact group $K$ the semigroup $\Gamma$ acts in
the space $L^2$ on the product of $m$ copies of $K$