title:
Relativistic description of magnetic moments in nuclei with doubly
  closed shells plus or minus one nucleon

abstract:
  Using the relativistic point-coupling model with density functional PC-PK1,
the magnetic moments of the nuclei $^{207}$Pb, $^{209}$Pb, $^{207}$Tl and
$^{209}$Bi with a $jj$ closed-shell core $^{208}$Pb are studied on the basis of
relativistic mean field (RMF) theory. The corresponding time-odd fields, the
one-pion exchange currents, and the first- and second-order corrections are
taken into account. The present relativistic results reproduce the data well.
The relative deviation between theory and experiment for these four nuclei is
6.1% for the relativistic calculations and somewhat smaller than the value of
13.2% found in earlier non-relativistic investigations. It turns out that the
$\pi$ meson is important for the description of magnetic moments, first by
means of one-pion exchange currents and second by the residual interaction
provided by the $\pi$ exchange.


title: Search for neutral and charged MSSM Higgs bosons in ATLAS

abstract:
  The results of Higgs boson searches in the context of the Minimal
Supersymmetric extension of the Standard Model (MSSM) in proton-proton
collisions with the ATLAS detector based on collected data corresponding to up
to 36 pb-1 are presented. Searches in the channels H+->cs, H+->taunu, and
H->tautau are discussed. All observations agree with the expectation of the
Standard Model (SM)-only hypothesis and thus exclusion limits are derived.


title: Towards closure testing of parton determinations

abstract:
  The method of closure testing for analysing the effectiveness of a PDF
fitting procedure is discussed. In order to pass a closure test, a fitting
methodology must be able to reproduce a known generating function in a fit to
an ideal pseudo-dataset generated by that PDF up to the level of experimental
uncertainty in the data. Here we present an initial study of the closure
property of the NNPDF fitting methodology. An idealised pseudo-dataset is
generated by a set of toy PDFs that differ substantially from previous NNPDF
determinations. In a fit to this pseudodata, the NNPDF methodology is shown to
be able to reproduce well the toy PDFs used as a generating function.


title:
On Deformation Quantization of Poisson-Lie Groups and Moduli Spaces of
  Flat Connections

abstract:
  We give simple explicit formulas for deformation quantization of Poisson-Lie
groups and of similar Poisson manifolds which can be represented as moduli
spaces of flat connections on surfaces. The star products depend on a choice of
Drinfe\v{l}d associator and are obtained by applying certain monoidal functors
(fusion and reduction) to commutative algebras in Drinfe\v{l}d categories. From
a geometric point of view this construction can be understood as a quantization
of the quasi-Poisson structures on moduli spaces of flat connections.


title: Modeling record-breaking stock prices

abstract:
  We study the statistics of record-breaking events in daily stock prices of
366 stocks from the Standard and Poors 500 stock index. Both the record events
in the daily stock prices themselves and the records in the daily returns are
discussed. In both cases we try to describe the record statistics of the stock
data with simple theoretical models. The daily returns are compared to i.i.d.
RV's and the stock prices are modeled using a biased random walk, for which the
record statistics are known. These models agree partly with the behavior of the
stock data, but we also identify several interesting deviations. Most
importantly, the number of records in the stocks appears to be systematically
decreased in comparison with the random walk model. Considering the
autoregressive AR(1) process, we can predict the record statistics of the daily
stock prices more accurately. We also compare the stock data with simulations
of the record statistics of the more complicated GARCH(1,1) model, which, in
combination with the AR(1) model, gives the best agreement with the
observational data. To better understand our findings, we discuss the survival
and first-passage times of stock prices on certain intervals and analyze the
correlations between the individual record events. After recapitulating some
recent results for the record statistics of ensembles of N stocks, we also
present some new observations for the weekly distributions of record events.


title:
Emergence of charge order from the vortex state of a high temperature
  superconductor

abstract:
  Evidence is mounting that charge order competes with superconductivity in
high Tc cuprates. Whether this has any relationship to the pairing mechanism is
unknown since neither the universality of the competition nor its microscopic
nature has been established. Here using nuclear magnetic resonance, we show
that, similar to La214, charge order in YBCO has maximum strength inside the
superconducting dome, at doping levels p = 0.11 - 0.12.We further show that the
overlap of halos of incipient charge order around vortex cores, similar to
those visualised in Bi2212, can explain the threshold magnetic field at which
long-range charge order emerges. These results reveal universal features of a
competition in which charge order and superconductivity appear as joint
instabilities of the same normal state, whose relative balance can be
field-tuned in the vortex state.


title:
PL-embedding the dual of two Jordan curves into $\mathbb{S}^ 3$ by an
  $O(n^ 2)$-algorithm

abstract:
  Let be given a {\em colored 3-pseudo-triangulation} $\mathcal{H}^\star$ with
$n$ tetrahedra. Colored means that each tetrahedron have vertices distinctively
colored 0,1,2,3. In a {\em pseudo} 3-triangulation the intersection of
simplices might be subsets of simplices of smaller dimensions (faces), instead
of a single maximal face, as for true triangulations. If $\mathcal{H}^\star$ is
the dual of a cell 3-complex induced (in an specific way to be made clear) by a
pair of Jordan curves with $2n$ transversal crossings, then we show that the
induced 3-manifold $|\mathcal{H}^\star|$ is $\mathbb{S}^3$ and we make
available an $O(n^2$)-algorithm to produce a PL-embedding
(\cite{rourke1982introduction}) of $\mathcal{H}^\star$ into $\mathbb{S}^3$.
This bound is rather surprising because such PL-embeddings are often of
exponential size. This work is the first step towards obtaining, via an $O(n^
2)$-algorithm, a framed link presentation inducing the same closed orientable
3-manifold as the one given by a colored pseudo-triangulation. Previous work on
this topic appear in \url{http://arxiv.org/abs/1212.0827},
\cite{linsmachadoA2012}, \url{http://arxiv.org/abs/1212.0826},
\cite{linsmachadoB2012} and \url{http://arxiv.org/abs/1211.1953},
\cite{linsmachadoC2012}. However, the exposition and the new proofs of this
paper are meant to be entirely self-contained.


title: The benefit of law-making power

abstract:
  We study optimal equilibria in multi-player games. An equilibrium is optimal
for a player, if her payoff is maximal. A tempting approach to solving this
problem is to seek optimal Nash equilibria, the standard form of equilibria
where no player has an incentive to deviate from her strategy. We argue that a
player with the power to define an equilibrium is in a position, where she
should not be interested in the symmetry of a Nash equilibrium, and ignore the
question of whether or not her outcome can be improved if the other strategies
are fixed. That is, she would only have to make sure that the other players
have no incentive to deviate. This defines a greater class of equilibria, which
may have better (and cannot have worse) optimal equilibria for the designated
powerful player. We apply this strategy to concurrent bimatrix games and to
turn based multi-player mean-payoff games. For the latter, we show that such
political equilibria as well as Nash equilibria always exist, and provide
simple examples where the political equilibrium is superior. We show that
constructing political and Nash equilibria are NP-complete problems. We also
show that, for a fixed number of players, the hardest part is to solve the
underlying two-player mean-payoff games: using an MPG oracle, the problem is
solvable in polynomial time. It is therefore in UP and CoUP, and can be solved
in pseudo polynomial and expected subexponential time.


title:
Fact-checking Ziegler's maximum entropy production principle beyond the
  linear regime and towards steady states

abstract:
  We challenge claims that the principle of maximum entropy production produces
physical phenomenological relations between conjugate currents and forces, even
beyond the linear regime, and that currents in networks arrange themselves to
maximize entropy production as the system approaches the steady state. In
particular: (1) we show that Ziegler's principle of thermodynamic orthogonality
leads to stringent reciprocal relations for higher order response coefficients,
and in the framework of stochastic thermodynamics, we exhibit a simple explicit
model that does not satisfy them; (2) on a network, enforcing Kirchhoff's
current law, we show that maximization of the entropy production prescribes
reciprocal relations between coarse-grained observables, but is not responsible
for the onset of the steady state, which is rather due to the minimum entropy
production principle.


title: X-ray Absorption of High Redshift Quasars

abstract:
  Soft X-ray photoelectric absorption of high-z quasars has been known for two
decades, but has no unambiguous astro-physical context. We construct the
largest sample to date of 58 high redshift quasars (z > 0.45) selected from the
XMM-Newton archive based on a high photon count criterion (> 1800). We measure
the optical depth tau at 0.5 keV, and find that 43% of the quasars show
significant absorption. We aim to find which physical parameters of the quasars
drive their observed absorption, e.g., redshift, radio luminosity, radio
loudness, or the X-ray luminosity. We compare the absorption behavior with
redshift with the pattern expected if the diffuse intergalactic medium (IGM) is
responsible for the observed absorption, and with a comparison sample of gamma
ray burst (GRB) X-ray afterglows. Although the z > 2 quasar opacity is
consistent with diffuse IGM absorption, many intermediate z (0.45 < z < 2)
quasars are not sufficiently absorbed for this scenario, and are appreciably
less absorbed than GRBs. Only 10/37 quasars at z < 2 are absorbed, and only
5/30 radio quiet quasars are absorbed. We find a weak correlation between tau
and z, and even a weaker correlation between tau and radio luminosity, which
leads to the conclusion that although a diffuse IGM origin for the quasar
absorption is unlikely, optical depth does seem to increase with redshift,
roughly as (1+z)^{2.2+-0.6}, tending at high-z to tau ~ 0.4, similar to the
high-z GRB values. This result can be explained by an ionized and clumpy IGM at
z < 2, and a cold, diffuse IGM at higher redshift. If, conversely, ascribed to
local absorption at the quasar, and owing to the steep L_x ~ (1+z)^{7.1+-0.5}
correlation in the present sample, the host column density scales as N_H ~
L_x^{0.7+-0.1}.


title: Equivariant indices of vector fields and 1-forms

abstract:
  Equivariant versions of the radial index and of the GSV-index of a vector
field or a 1-form on a singular variety with an action of a finite group are
defined. They have values in the Burnside ring of the group. Poincar\'e-Hopf
type theorems for them are proven and some of their properties are described.


title: The Planck distribution of phonons in a Bose-Einstein condensate

abstract:
  The Planck distribution of photons emitted by a black body led to the
development of quantum theory. An analogous distribution of phonons should
exist in a Bose-Einstein condensate. We observe this Planck distribution of
thermal phonons in a 3D condensate. This observation provides an important
confirmation of the basic nature of the condensate's quantized excitations. In
contrast to the bunching effect, the density fluctuations are seen to increase
with increasing temperature. This is due to the non-conservation of the number
of phonons. In the case of rapid cooling, the phonon temperature is out of
equilibrium with the surrounding thermal cloud. In this case, a Bose-Einstein
condensate is not as cold as previously thought. These measurements are enabled
by our in situ k-space technique.


title: Band structures and intruder $\pi$$i_{13/2}$ state in $^{197}$Tl

abstract:
  The excited states in the odd-$A$ $^{197}$Tl nucleus have been studied by
populating them using the $^{197}$Au($\alpha$, 4$n$)$^{197}$Tl reaction at the
beam energy of 48 MeV. The $\gamma-\gamma$ coincidence data were taken using a
combination of clover, LEPS and single crystal HPGe detectors. Precise spin and
parity assignments of the excited states have been done through the
polarization and the DCO measurements. A new band structure has been identified
and the evidence for a possible intruder $\pi i_{13/2}$ state has been found
for the first time. Possible configurations of the observed bands have been
discussed. The total Routhian surface calculations have been performed to study
the shape of $^{197}$Tl for different configurations.


title:
Of dice and men. Subjective priors, gauge invariance, and nonequilibrium
  thermodynamics

abstract:
  "Ceci n'est pas une pipe" wrote Ren\'e Magritte on what was only the
representation of a pipe. Phenomena and their physical descriptions differ, and
in particular the laws ruling the former might enjoy symmetries that have to be
spent to attain the latter. So, inertial frames are necessary to draw numbers
out of Newtonian mechanics and confront with experiment, but ultimately the
laws of mechanics are independent of reference frames. Generalizing work done
in Ref. [M. Polettini, EPL 97 (2012) 30003] to continuous systems, we discuss
from a foundational point of view how subjectivity in the choice of reference
prior probability is a (gauge) symmetry of thermodynamics. In particular, a
change of priors corresponds to a change of coordinates. Employing an approach
based on the stochastic thermodynamics of continuous state-space diffusion
processes, we discuss the difference between thermostatic and thermodynamic
observables and show that, while the quantification of entropy depends on
priors, the second law of thermodynamics is formulated in terms of invariant
quantities, in particular the curvature of the thermodynamic force (gauge
potential), which we calculate in a few examples of processes led by different
nonequilibrium mechanisms.


title:
Inhomogeneous Si-doping of gold-seeded InAs nanowires grown by molecular
  beam epitaxy

abstract:
  We have investigated in-situ Si doping of InAs nanowires grown by molecular
beam epitaxy from gold seeds. The effectiveness of n-type doping is confirmed
by electrical measurements showing an increase of the electron density with the
Si flux. We also observe an increase of the electron density along the
nanowires from the tip to the base, attributed to the dopant incorporation on
the nanowire facets whereas no detectable incorporation occurs through the
seed. Furthermore the Si incorporation strongly influences the lateral growth
of the nanowires without giving rise to significant tapering, revealing the
complex interplay between axial and lateral growth.


title: Model of the AdS/QFT duality

abstract:
  It is observed and illustrated in a greatly simplified example that the idea
of AdS/QFT duality can be considered a special case of the Ehrenfest's
correspondence principle between classical and quantum mechanics in the context
of relativistic dynamics of fields and renormalization group procedure for
effective particles.


title: Some Comments on Dilaton Gravity

abstract:
  A Weyl invariant extension of Einstein gravity is studied. It simply consists
in the group averaging of Einstein's action under Weyl transformations.
Contradicting cherished beliefs, a conformal anomaly is found in the trace of
the equations of motion if diffeomorphism invariance is to be a symmetry of the
quantum theory. This anomaly however vanishes on shell, which signals the
existence of another gauge in which the anomaly is absent. It can be made also
to vanish off-shell at the price of losing diffeomorphism invariance


title: \eta and \eta' transition form factors from rational approximants

abstract:
  The \eta and \eta' transition form factors in the space-like region are
analyzed at low and intermediate energies in a model-independent way through
the use of rational approximants. The slope and curvature parameters of the
form factors as well as their values at zero and infinity are extracted from
experimental data. The impact of these results on the mixing parameters of the
\eta-\eta' system and the pseudoscalar-exchange contributions to the hadronic
light-by-light scattering part of the anomalous magnetic moment are also
discussed.


title:
Comparing the Expressive Power of the Synchronous and the Asynchronous
  pi-calculi

abstract:
  The Asynchronous pi-calculus, proposed by Honda and Tokoro (1991) and,
independently, by Boudol (1992), is a subset of the pi-calculus (Milner, 1992)
which contains no explicit operators for choice and output-prefixing. The
communication mechanism of this calculus, however, is powerful enough to
simulate output-prefixing, as shown by Honda and Tokoro (1991) and by Boudol
(1992), and input-guarded choice, as shown by Nestmann and Pierce (2000). A
natural question arises, then, whether or not it is as expressive as the full
pi-calculus. We show that this is not the case. More precisely, we show that
there does not exist any uniform, fully distributed translation from the
pi-calculus into the asynchronous pi-calculus, up to any "reasonable" notion of
equivalence. This result is based on the incapability of the asynchronous
pi-calculus to break certain symmetries possibly present in the initial
communication graph. By similar arguments, we prove a separation result between
the pi-calculus and CCS, and between the pi-calculus and the pi-calculus with
internal mobility, a subset of the pi-calculus proposed by Sangiorgi where the
output actions can only transmit private names.


title: On the Physical Origin of the Anomalous Magnetic Moment of Electron

abstract:
  A simple physical insight into the origin of the magnetic moment anomaly of
electron is presented. This approach is based on the assumption that the
electromagnetic mass of the electron due to the electric field generated by
electron charge in the exterior of the sphere of radius half of the Compton
wavelength of the electron, does not contribute to the magnetic moment of the
electron. This explanation is compatible with the well-known quantum
electrodynamics approach. A formula is derived, which is similar to that
obtained by quantum electrodynamics calculus of one loop contribution to
anomalous part of the magnetic moment.


title:
Cycles of strategies and changes of distribution in public goods game:
  An experimental investigation

abstract:
  In this communication, a simple mechanism in the optional public goods game
is experimentally investigated using two experimental settings; and first time,
the cyclic strategy pattern in full state space is demonstrated by means of
velocity. It is, furthermore, elaborated that the strategies of cooperation,
defection and nonparticipant form a Rock-Paper-Scissors type cycle, and the
cycle of three strategies are persistent over 200 rounds. This cycle is very
similar to the cycle given by evolutionary dynamics e.g. replicator dynamics.
The mechanism that nonparticipant can sustain cooperation is driven by the
Rock-Paper-Scissors type of cyclic dominance in the three strategies. That is,
if the cycle is existent, the cooperation will always sustain. Meanwhile, the
distribution of social states changes in the state space and from cooperation
as the most frequent strategy to defection and, from defection to
nonparticipant, forms a clear rotation path in a long run. These results seem
to implicate that the evolutionary dynamics has ability to capture the real
dynamics applying not only on biosphere, but also on human society.


title: Global Weak Solutions to Non-isothermal Nematic Liquid Crystals in 2D

abstract:
  In this paper, we prove the global existence of weak solutions to the
non-isothermal nematic liquid crystal system on $\mathbb T^2$, based on a new
approximate system which is different from the classical Ginzburg-Landau
approximation. Local energy inequalities are employed to recover the estimates
on the second order spacial derivatives of the director fields locally in time,
which cannot be derived from the basic energy balance. It is shown that these
weak solutions conserve the total energy and while the kinetic and potential
energies transfer to the heat energy precisely. Furthermore, it is also
established that these weak solutions have at most finite many singular times
at which the energy concentration occurs, and as a result, the temperature must
increase suddenly at each singular time on some part of $\mathbb T^2$.


title: Twins of s-free numbers

abstract:
  We generalise the square sieve developed by Heath-Brown to higher powers in
order to improve on the error term for the problem of counting consecutive
power-free numbers.


title:
Properties of dense, asymmetric nuclear matter in
  Dirac-Brueckner-Hartree-Fock approach

abstract:
  Within the Dirac-Brueckner-Hartree-Fock approach, using the Bonn potentials,
we investigate the properties of dense, asymmetric nuclear matter and apply it
to neutron stars. In the actual calculations of the nucleon self-energies and
the energy density of matter, we study in detail the validity of an
angle-averaged approximation and an averaging of the total momentum squared of
interacting two-nucleons in nuclear matter. For practical use, we provide
convenient parametrizations for the equation of state for symmetric nuclear
matter and pure neutron matter. We also parametrize the nucleon self-energies
in terms of polynomials of nucleon momenta. Those parametrizations can
accurately reproduce the numerical results up to high densities.


title:
A diversity of dusty AGN tori: Data release for the VLTI/MIDI AGN Large
  Program and first results for 23 galaxies

abstract:
  The AGN-heated dust distribution (the "torus") is increasingly recognized not
only as the absorber required in unifying models, but as a tracer for the
reservoir that feeds the nuclear Super-Massive Black Hole. Yet, even its most
basic structural properties (such as its extent, geometry and elongation) are
unknown for all but a few archetypal objects. Since most AGNs are unresolved in
the mid-infrared, we utilize the MID-infrared interferometric Instrument (MIDI)
at the Very Large Telescope Interferometer (VLTI) that is sensitive to
structures as small as a few milli-arcseconds (mas). We present here an
extensive amount of new interferometric observations from the MIDI AGN Large
Program (2009 - 2011) and add data from the archive to give a complete view of
the existing MIDI observations of AGNs. Additionally, we have obtained
high-quality mid-infrared spectra from VLT/VISIR. We present correlated and
total flux spectra for 23 AGNs and derive flux and size estimates at 12 micron
using simple axisymmetric geometrical models. Perhaps the most surprising
result is the relatively high level of unresolved flux and its large scatter:
The median "point source fraction" is 70 % for type 1 and 47 % for type 2 AGNs
meaning that a large part of the flux is concentrated on scales smaller than
about 5 mas (0.1 - 10 pc). Among sources observed with similar spatial
resolution, it varies from 20 % - 100 %. For 18 of the sources, two nuclear
components can be distinguished in the radial fits. While these models provide
good fits to all but the brightest sources, significant elongations are
detected in eight sources. The half-light radii of the fainter sources are
smaller than expected from the size ~ L^0.5 scaling of the bright sources and
show a large scatter, especially when compared to the relatively tight
size--luminosity relation in the near-infrared.


title: On the curvature of level sets of harmonic functions

abstract:
  If a real harmonic function inside the open unit disk $B(0,1) \subset
\mathbb{R}^2$ has its level set $\left\{x: u(x) = u(0)\right\}$ diffeomorphic
to an interval, then we prove the sharp bound $\kappa \leq 8$ on the curvature
of the level set $\left\{x: u(x) = u(0)\right\}$ in the origin. The bound is
sharp and we give the unique (up to symmetries) extremizer.


title: Non-equilibrium interfaces in colloidal fluids

abstract:
  The time-dependent structure, interfacial tension, and evaporation of an
oversaturated colloid-rich (liquid) phase in contact with an undersaturated
colloid-poor (vapor) phase of a colloidal dispersion is investigated
theoretically during the early-stage relaxation, where the interface is
relaxing towards a local equilibrium state while the bulk phases are still out
of equilibrium. Since systems of this type exhibit a clear separation of
colloidal and solvent relaxation time scales with typical times of interfacial
tension measurements in between, they can be expected to be suitable for
analogous experimental studies, too. The major finding is that, irrespective of
how much the bulk phases differ from two-phase coexistence, the interfacial
structure and the interfacial tension approach those at two-phase coexistence
during the early-stage relaxation process. This is a surprising observation
since it implies that the relaxation towards global equilibrium of the
interface is not following but preceding that of the bulk phases. Scaling forms
for the local chemical potential, the flux, and the dissipation rate exhibit
qualitatively different leading order contributions depending on whether an
equilibrium or a non-equilibrium system is considered. The degree of
non-equilibrium between the bulk phases is found to not influence the
qualitative relaxation behavior (i.e., the values of power-law exponents), but
to determine the quantitative deviation of the observed quantities from their
values at two-phase coexistence. Whereas the underlying dynamics differs
between colloidal and molecular fluids, the behavior of quantities such as the
interfacial tension approaching the equilibrium values during the early-stage
relaxation process, during which non-equilibrium conditions of the bulk phases
are not changed, can be expected to occur for both types of systems.


title:
TEC evidence for near-equatorial energy deposition by 30-keV electrons
  in the topside ionosphere

abstract:
  Observations of energetic electrons (10 - 300 keV) by NOAA/POES and DMSP
satellites at heights <1000 km during the period from 1999 to 2010 allowed
finding abnormal intense fluxes of ~10^6 - 10^7 cm-2 s-1 sr-1 for quasi-trapped
electrons appearing within the forbidden zone of low latitudes over the
African, Indo-China, and Pacific regions. Extreme fluxes appeared often in the
early morning and persisted for several hours during the maximum and recovery
phase of geomagnetic storms. We analyzed nine storm-time events when extreme
electron fluxes first appeared in the Eastern Hemisphere, then drifted further
eastward toward the South-Atlantic Anomaly. Using the electron spectra, we
estimated the possible ionization effect produced by quasi-trapped electrons in
the topside ionosphere. The estimated ionization was found to be large enough
to satisfy observed storm-time increases in the ionospheric total electron
content determined for the same spatial and temporal ranges from global
ionospheric maps. Additionally, extreme fluxes of quasi-trapped electrons were
accompanied by the significant elevation of the low-latitude F-layer obtained
from COSMIC/FORMOSAT-3 radio occultation measurements. We suggest that the
storm-time ExB drift of energetic electrons from the inner radiation belt is an
important driver of positive ionospheric storms within low-latitude and
equatorial regions.


title:
Weak Cyclic Monotonicity and Existence of Solutions of Differential
  Inclusions

abstract:
  The notion of weak cyclic monotonicity of set-valued maps generalizing the
cyclic monotonicity is introduced. The existence of solutions of differential
inclusions with compact, upper semi-continuous, not necessarily convex
right-hand sides in R^n is proved for weakly cyclic monotone right-hand sides.


title: The stochastic nature induced by laser noise in narrow transitions

abstract:
  We use a probabilistic method to describe the effect of laser noise on the
laser-atom interaction, in the case that the atom is a two level system without
spontaneous emission. The stochastic differential equation for the laser-atom
interaction is analyzed in the sense of perturbation approach, and we construct
a stochastic process corresponding to the time evolution of the atom's wave
function, whose extra randomness is induced by the laser noise. It also
provides the layout of a theory for the possible experiment of measuring the
laser line width by driving a narrow atomic transition.


title: Well-posedness of Non-autonomous Evolutionary Inclusions

abstract:
  A class of non-autonomous differential inclusions in a Hilbert space setting
is considered. The well-posedness for this class is shown by establishing the
mappings involved as maximal monotone relations. Moreover, the causality of the
so established solution operator is addressed. The results are exemplified by
the equations of thermoplasticity with time dependent coefficients and by a
non-autonomous version of the equations of viscoplasticity with internal
variables.


title:
A Web-based modeling tool for the SEMAT Essence theory of Software
  Engineering

abstract:
  As opposed to more mature subjects, software engineering lacks general
theories to establish its foundations as a discipline. The Essence Theory of
software engineering (Essence) has been proposed by the Software Engineering
Methods and Theory (SEMAT) initiative. Essence goal is to develop a
theoretically sound basis for software engineering practice and its wide
adoption. Essence is yet far from reaching academic and industry adoption.
Reasons include a struggle to foresee its utilization potential and the lack of
tools implementing it. SEMAT Accelerator (SematAcc) is a Web-positioning tool
for a software engineering endeavor, which implements the SEMAT's Essence
kernel. SematAcc allows using Essence, thus helping to understand it. The tool
enables teaching, adopting, and researching Essence in controlled experiments
and case studies.


title:
On the Gaussian limiting distribution of lattice points in a
  parallelepiped

abstract:
  Let $ \Gamma \subset \RR^s $ be a lattice obtained from a module in a totally
real algebraic number field. Let $\cR(\btheta, \bN)$ be an error term in the
lattice point problem for the parallelepiped $[-\theta_1 N_1,\theta_1 N_1]
\times ... \times [-\theta_s N_s,\theta_s N_{s}]$. In this paper, we prove that
$\cR(\btheta, \bN)/\sigma(\cR,\bN) $ have Gaussian limiting distribution as $N
\to \infty$, where $\btheta=(\theta_1,...,\theta_s)$ is a uniformly distributed
random variable in $[0,1]^s$, $N=N_1 ... N_s$ and $\sigma(\cR,\bN) \asymp (\log
N)^{(s-1)/2}$. We obtain also a similar result for the low discrepancy sequence
corresponding to $\Gamma$.


title: Dressing transformations of constrained Willmore surfaces

abstract:
  We use the dressing method to construct transformations of constrained
Willmore surfaces in arbitrary codimension. An adaptation of the
Terng--Uhlenbeck theory of dressing by simple factors to this context leads us
to define B\"acklund transforms of these surfaces for which we prove Bianchi
permutability. Specialising to codimension 2, we generalise the Darboux
transforms of Willmore surfaces via Riccati equations, due to
Burstall-Ferus-Leschke-Pedit-Pinkall, to the constrained Willmore case and show
that they amount to our B\"acklund transforms with real spectral parameter.


title: pi-bonds in graphene and surface of topological insulator Bi2Se3

abstract:
  Chemical bond analysis for the topological insulator (TI) Bi2Se3 following
valence bond theory and VSEPR rule is proposed and compared to that of
graphene. The existence of pi-bond trimers on surface Se-layer is revealed to
be responsible for the unusual 2D surface conduction found in the prototype Z2
topological insulator Bi2Se3, which shows great similarity to the ideal
"surface-only" 2D material graphene with surface band in Dirac cone shape. The
pi-bond trimers on the surface of TI form a dynamic pi-bond conjugated system
of implicit chirality. Local pi-bond energy exchange in cross-bridge model is
proposed responsible for the unique 2D surface conduction for topological
insulator Bi2Se3, and the similar low dimensional conduction mechanism can also
be identified in graphene and conductive polymers. Preliminary supporting
evidence for the existence of pi-bonds is provided by the commonly assigned pi
plasmon for the spectral feature near 7 eV in graphite and Bi2Se3 using
electron energy-loss spectroscopy (EELS).


title: Temperature-Dependent Defect Dynamics in the Network Glass SiO2

abstract:
  We investigate the long time dynamics of a strong glass former, SiO2, below
the glass transition temperature by averaging single particle trajectories over
time windows which comprise roughly 100 particle oscillations. The structure on
this coarse-grained time scale is very well defined in terms of coordination
numbers, allowing us to identify ill-coordinated atoms, called defects in the
following. The most numerous defects are OO neighbors, whose lifetimes are
comparable to the equilibration time at low temperature. On the other hand SiO
and OSi defects are very rare and short lived. The lifetime of defects is found
to be strongly temperature dependent, consistent with activated processes.
Single-particle jumps give rise to local structural rearrangements. We show
that in SiO2 these structural rearrangements are coupled to the creation or
annihilation of defects, giving rise to very strong correlations of jumping
atoms and defects.


title:
On the lower bound in the lattice point remainder problem for a
  parallelepiped

abstract:
  Let $ \Gamma \subset \RR^s $ be a lattice, obtained from a module in a
totally real algebraic number field. Let $G$ be an axis parallel
parallelepiped, and let $|G|$ be a volume of $G$. In this paper we prove that
  $\limsup_{|G| \to \infty} (\det \Gamma \#(\Gamma\cap G)-|G|)/\ln^{s-1} |G|
>0.$
  Thus the known estimate $\det \Gamma \#(\Gamma\cap G)=|G| +O(\ln^{s-1} |G|)$
is exact. We obtain also a similar result for the low discrepancy sequence
corresponding to $\Gamma$.


title:
Optimal decay rate of the bipolar Euler-Poisson system with damping in
  $\mathbb{R}^3$

abstract:
  By rewriting a bipolar Euler-Poisson equations with damping into an Euler
equation with damping coupled with an Euler-Poisson equation with damping, and
using a new spectral analysis, we obtain the optimal decay results of the
solutions in $L^2$-norm, which improve theose in \cite{Li3, Wu3}. More
precisely, the velocities $u_1,u_2$ decay at the $L^2-$rate $(1+t)^{-{5}{4}}$,
which is faster than the normal $L^2-$rate $(1+t)^{-{3}{4}}$ for the Heat
equation and the Navier-Stokes equations. In addition, the disparity of two
densities $\rho_1-\rho_2$ and the disparity of two velocities $u_1-u_2$ decay
at the $L^2$-rate $(1+t)^{-2}$.


title: Initial energy density of p+p collisions at the LHC

abstract:
  Accelerating, exact, explicit and simple solutions of relativistic
hydrodynamics allow for a simple description of highly relativistic p+p
collisions. These solutions yield a finite rapidity distribution, thus they
lead to an advanced estimate of the initial energy density of high energy
collisions. We show that such an advanced estimate yields an initial energy
density in $\sqrt{s}=7$ and 8 TeV p+p collisions at LHC around or above the
critical energy density from lattice QCD, and a corresponding initial
temperature above the critical temperature from QCD and the Hagedorn
temperature. We also show, that several times the critical energy density may
have been reached in high multiplicity events, hinting at a non-hadronic medium
created in high multiplicity $\sqrt{s}=7$ and 8 TeV p+p collisions.


title:
An HST Optical to Near-IR Transmission Spectrum of the Hot Jupiter
  WASP-19b: Detection of Atmospheric Water and Likely Absence of TiO

abstract:
  We measure the transmission spectrum of WASP-19b from 3 transits using
low-resolution optical spectroscopy from the HST Space Telescope Imaging
Spectrograph (STIS). The STIS spectra cover a wavelength range of 0.29-1.03
microns with resolving power R=500. The optical data are combined with archival
near-IR data from the HST Wide Field Camera 3 (WFC3) G141 grism, covering the
wavelength range 1.087-1.687 micron, with resolving power R=130. We obtain the
transmission spectrum from 0.53-1.687 microns with S/N levels between 3000 and
11,000 in 0.1 micron bins. WASP-19 is a very active star, with optical stellar
flux varying by a few per cent over time. We correct the transit light curves
for the effects of stellar activity using ground-based activity monitoring with
the Cerro Tololo Inter-American Observatory (CTIO). While we were not able to
construct a transmission spectrum using the blue optical data due to the
presence of large occulted star spots, we were able to use the spot crossings
to help constrain the mean stellar spot temperature. To search for predicted
features in the hot-Jupiter atmosphere, we also define spectral indices for
differential radius measurements to specifically search for the presence of TiO
and alkali line features. Our measurements rule out TiO features predicted for
a planet of WASP-19b's equilibrium temperature (2050 K) in the transmission
spectrum at the 2.7-2.9 sigma confidence level, depending on atmospheric model
formalism. The WFC3 transmission spectrum shows strong absorption features due
to the presence of H2O, which is detected at the 4 sigma confidence level
between 1.1 and 1.4 microns. The results indicate that WASP-19b is a planet
with no or low levels of TiO and without a high C/O ratio. The lack of
observable TiO features are possibly due to rainout, breakdown from stellar
activity or the presence of other absorbers in the optical.


title: Mitigating Epidemics through Mobile Micro-measures

abstract:
  Epidemics of infectious diseases are among the largest threats to the quality
of life and the economic and social well-being of developing countries. The
arsenal of measures against such epidemics is well-established, but costly and
insufficient to mitigate their impact. In this paper, we argue that mobile
technology adds a powerful weapon to this arsenal, because (a) mobile devices
endow us with the unprecedented ability to measure and model the detailed
behavioral patterns of the affected population, and (b) they enable the
delivery of personalized behavioral recommendations to individuals in real
time. We combine these two ideas and propose several strategies to generate
such recommendations from mobility patterns. The goal of each strategy is a
large reduction in infections, with a small impact on the normal course of
daily life. We evaluate these strategies over the Orange D4D dataset and show
the benefit of mobile micro-measures, even if only a fraction of the population
participates. These preliminary results demonstrate the potential of mobile
technology to complement other measures like vaccination and quarantines
against disease epidemics.


title:
Quantified HI Morphology VII: star-formation and tidal influence on
  local dwarf HI morphology

abstract:
  Scale-invariant morphology parameters applied to atomic hydrogen maps (HI) of
galaxies can be used to quantify the effects of tidal interaction or
star-formation on the ISM. Here we apply these parameters, Concentration,
Asymmetry, Smoothness, Gini, M20, and the GM parameter, to two public surveys
of nearby dwarf galaxies, the VLA-ANGST and LITTLE-THINGS survey, to explore
whether tidal interaction or the ongoing or past star-formation is a dominant
force shaping the HI disk of these dwarfs.
  Previously, HI morphological criteria were identified for ongoing
spiral-spiral interactions. When we apply these to the Irregular dwarf
population, they either select almost all or none of the population. We find
that only the Asymmetry-based criteria can be used to identify very isolated
dwarfs (i.e., these have a low tidal indication). Otherwise, there is little or
no relation between the level of tidal interaction and the HI morphology. We
compare the HI morphology to three star-formation rates based on either Halpha,
FUV or the resolved stellar population, probing different star-formation
time-scales.
  The HI morphology parameters that trace the inequality of the distribution,
the Gini, GM, and M20 parameters, correlate weakly with all these
star-formation rates. This is in line with the picture that local physics
dominates the ISM appearance and not tidal effects. Finally, we compare the
SDSS measures of star-formation and stellar mass to the HI morphological
parameters for all four HI surveys. In the two lower-resolution HI surveys
(12"), there is no relation between star-formation measures and HI morphology.
The morphology of the two high-resolution HI surveys (6"), the Asymmetry,
Smoothness, Gini, M20, and GM, do show a link to the total star-formation, but
a weak one.


title: 3D Supergravity from wrapped D3-branes

abstract:
  AdS_3 solutions dual to N = (0,2) SCFTs arise when D3-branes wrap Kahler
two-cycles in manifolds with SU(4) holonomy. Here we review known AdS_3
solutions and identify the corresponding three-dimensional gauged
supergravities, solutions of which uplift to type IIB supergravity. In
particular, we discuss gauged supergravities dual to twisted compactifications
on Riemann surfaces of both N=4 SYM and N =1 SCFTs with Sasaki-Einstein duals.
We check in each case that c-extremization gives the exact central charge and R
symmetry. For completeness, we also study AdS_3 solutions from intersecting
D3-branes, generalise recent KK reductions of Detournay & Guica and identify
the underlying gauged supergravities. Finally, we discuss examples of
null-warped AdS_3 solutions to three-dimensional gauged supergravity, all of
which embed in string theory.


title: Performance Bounds for Constrained Linear Min-Max Control

abstract:
  This paper proposes a method to compute lower performance bounds for
discrete-time infinite-horizon min-max control problems with input constraints
and bounded disturbances. Such bounds can be used as a performance metric for
control policies synthesized via suboptimal design techniques. Our approach is
motivated by recent work on performance bounds for stochastic constrained
optimal control problems using relaxations of the Bellman equation. The central
idea of the paper is to find an unconstrained min-max control problem, with
negatively weighted disturbances as in H infinity control, that provides the
tightest possible lower performance bound on the original problem of interest
and whose value function is easily computed. The new method is demonstrated via
a numerical example for a system with box constrained input.


title: Localized Index and $L^2$-Lefschetz fixed point formula for orbifolds

abstract:
  We study a class of localized indices for the Dirac type operators on a
complete Riemannian orbifold, where a discrete group acts properly,
co-compactly and isometrically. These localized indices, generalizing the
$L^2$-index of Atiyah, are obtained by taking certain traces of the higher
index for the Dirac type operators along conjugacy classes of the discrete
group. Applying the local index technique, we also obtain an $L^2$-version of
the Lefschetz fixed point formula for orbifolds. These cohomological formulae
for the localized indices give rise to a class of refined topological
invariants for the quotient orbifold.


title:
Certifying non-existence of undesired locally stable equilibria in
  formation shape control problems

abstract:
  A fundamental control problem for autonomous vehicle formations is formation
shape control, in which the agents must maintain a prescribed formation shape
using only information measured or communicated from neighboring agents. While
a large and growing literature has recently emerged on distance-based formation
shape control, global stability properties remain a significant open problem.
Even in four-agent formations, the basic question of whether or not there can
exist locally stable incorrect equilibrium shapes remains open. This paper
shows how this question can be answered for any size formation in principle
using semidefinite programming techniques for semialgebraic problems, involving
solutions sets of polynomial equations, inequations, and inequalities.


title: Spectral properties of the Laplacian of multiplex networks

abstract:
  One of the more challenging tasks in the understanding of dynamical
properties of models on top of complex networks is to capture the precise role
of multiplex topologies. In a recent paper, Gomez et al. [Phys. Rev. Lett. 101,
028701 (2013)] proposed a framework for the study of diffusion processes in
such networks. Here, we extend the previous framework to deal with general
configurations in several layers of networks, and analyze the behavior of the
spectrum of the Laplacian of the full multiplex. We derive an interesting
decoupling of the problem that allow us to unravel the role played by the
interconnections of the multiplex in the dynamical processes on top of them.
Capitalizing on this decoupling we perform an asymptotic analysis that allow us
to derive analytical expressions for the full spectrum of eigenvalues. This
spectrum is used to gain insight into physical phenomena on top of multiplex,
specifically, diffusion processes and synchronizability.


title:
Sets of beta-expansions and the Hausdorff Measure of Slices through
  Fractals

abstract:
  We study natural measures on sets of beta-expansions and on slices through
self similar sets. In the setting of beta-expansions, these allow us to better
understand the measure of maximal entropy for the random beta-transformation
and to reinterpret a result of Lindenstrauss, Peres and Schlag in terms of
equidistribution. Each of these applications is relevant to the study of
Bernoulli convolutions. In the fractal setting this allows us to understand how
to disintegrate Hausdorff measure by slicing, leading to conditions under which
almost every slice through a self similar set has positive Hausdorff measure,
generalising long known results about almost everywhere values of the Hausdorff
dimension.


title: Smallest Squared Squares

abstract:
  In this paper we have a look at squared squares with small integer
sidelengths, where the only restriction is that any two subsquares of the same
size are not allowed to share a full border. We prove that there are exactly
two such squared squares (and their mirrored versions) up to and including size
17x17. They are shown in Figure 1 (page 2).


title: Ulrich ideals and modules over two-dimensional rational singularities

abstract:
  The main aim of this paper is to classify Ulrich ideals and Ulrich modules
over two-dimensional Gorenstein rational singularities (rational double points)
from a geometric point of view. To achieve this purpose, we introduce the
notion of (weakly) special Cohen-Macaulay modules with respect to ideals, and
study the relationship between those modules and Ulrich modules with respect to
good ideals.


title: Towards a photometric metallicity scale for open clusters

abstract:
  Open clusters are a useful tool when investigating several topics connected
with stellar evolution; for example the age or distance can be more accurately
determined than for field stars. However, one important parameter, the
metallicity, is only known for a marginal percentage of open clusters. We aim
at a consistent set of parameters for the open clusters investigated in our
photometric Delta-a survey of chemically peculiar stars. Special attention is
paid to expanding our knowledge of cluster metallicities and verifying their
scale. Making use of a previously developed method based on normalised
evolutionary grids and photometric data, the distance, age, reddening, and
metallicity of open clusters were derived. To transform photometric
measurements into effective temperatures to use as input for our method, a set
of temperature calibrations for the most commonly used colour indices and
photometric systems was compiled. We analysed 58 open clusters in total. Our
derived metallicity values were in excellent agreement with about 30
spectroscopically studied targets. The mean value of the absolute deviations
was found to be 0.03 dex, with no noticeable offset or gradient. The method was
also applied using recent evolutionary models based on the currently accepted
lower solar abundance value Z=0.014. No significant differences were found
compared to grids using the former adopted solar value Z=0.02. Furthermore,
some divergent photometric datasets were identified and discussed. The method
provides an accurate way of obtaining properly scaled metallicity values for
open clusters. In light of present and future homogeneous photometric sky
surveys, the sample of stellar clusters can be extended to the outskirts of the
Milky Way, where spectroscopic studies are almost impossible. This will help
for determining galactic metallicity gradients in more detail.


title: On the Eclipse of Thales, Cycles and Probabilities

abstract:
  According to classical tradition, Thales of Miletus predicted the total solar
eclipse that took place on 28 May 585 BCE. Even if some authors have flatly
denied the possibility of such a prediction, others have struggled to find
cycles which would justify the achievement of the philosopher. Some of the
proposed cycles have already been refuted, but two of them, namely those of
Willy Hartner and Dirk Couprie, remain unchallenged. This paper presents some
important objections to these two possibilities, based on the fact that these
authors do not list all the eclipses potentially visible by their criteria. In
addition, any explanation based on cycles will need to face the complex problem
of visibility (smallest observable eclipse, weather...). The present article
also includes a statistical study on the predictability of solar eclipses for a
variety of periods, similar to that performed by Willy Hartner for lunar
eclipses, resulting in lower probabilities in the solar case (and percentages
depend on the chosen magnitude limit). The conclusion is that none of the
cycles proposed so far provides a satisfactory explanation of the prediction,
and, on statistical grounds, none of the periods studied leads to a significant
probability of success with solar eclipse cycles.


title: Immersing carbon nano-tubes in cold atomic gases

abstract:
  We investigate the sympathetic relaxation of a free-standing, vibrating
carbon nano-tube that is mounted on an atom chip and is immersed in a cloud of
ultra-cold atoms. Gas atoms colliding with the nano-tube excite phonons via a
Casimir-Polder potential. We use Fermi's Golden Rule to estimate the relaxation
rates for relevant experimental parameters and develop a fully dynamic theory
of relaxation for the multi-mode phononic field embedded in a thermal atomic
reservoir. Based on currently available experimental data, we identify the
relaxation rates as a function of atom density and temperature that are
required for sympathetic ground state cooling of carbon nano-tubes.


title: Computing the Fr\'{e}chet distance with shortcuts is NP-hard

abstract:
  We study the shortcut Fr\'{e}chet distance, a natural variant of the
Fr\'{e}chet distance, that allows us to take shortcuts from and to any point
along one of the curves. The classic Fr\'echet distance is a bottle-neck
distance measure and hence quite sensitive to outliers. The shortcut
Fr\'{e}chet distance allows us to cut across outliers and hence produces
significantly more meaningful results when dealing with real world data.
Driemel and Har-Peled recently described approximation algorithms for the
restricted case where shortcuts have to start and end at input vertices. We
show that, in the general case, the problem of computing the shortcut
Fr\'{e}chet distance is NP-hard. This is the first hardness result for a
variant of the Fr\'{e}chet distance between two polygonal curves in the plane.
We also present two algorithms for the decision problem: a 3-approximation
algorithm for the general case and an exact algorithm for the vertex-restricted
case. Both algorithms run in O(n^3 log n) time.


title: An elementary non-recursive expression for the partition function P(n)

abstract:
  Consideration of a classification of the number of partitions of a natural
number according to the members of sub-partitions differing from unity leads to
a non-recursive formula for the number of irreducible representations of the
symmetric group Sn. This article was published, long ago, under the title A
non-recursive expression for the number of irreducible representations of the
Symmetric Group Sn, Physica 114A, 1982, 361-364, North-Holland Publishing Co.
The Introduction has been, somewhat, improved, however, the handmade result
remains unproved.


title:
Time-Resolved Properties and Global Trends in dMe Flares from
  Simultaneous Photometry and Spectra

abstract:
  We present a homogeneous survey of line and continuum emission from
near-ultraviolet (NUV) to optical wavelengths during twenty M dwarf flares with
simultaneous, high cadence photometry and spectra. These data were obtained to
study the white-light continuum components at bluer and redder wavelengths than
the Balmer jump. Our goals were to break the degeneracy between emission
mechanisms that have been fit to broadband colors of flares and to provide
constraints for radiative-hydrodynamic (RHD) flare models that seek to
reproduce the white-light flare emission. The main results from the continuum
analysis are the following: 1) the detection of Balmer continuum (in emission)
that is present during all flares and with a wide range of relative
contributions to the continuum flux at bluer wavelengths than the Balmer jump;
2) a blue continuum at flare maximum that is linearly decreasing with
wavelength from \lambda = 4000-4800\AA, matched by the spectral shape of hot,
blackbody emission with typical temperatures of T_{BB}~9000-14,000 K; 3) a
redder continuum apparent at wavelengths longer than H\beta\ (\lambda >
4900\AA) which becomes relatively more important to the energy budget during
the late gradual phase. We calculate Balmer jump flux ratios and compare to RHD
model spectra. The model ratios are too large and the blue-optical (\lambda =
4000-4800\AA) slopes are too red in both the impulsive and gradual decay phases
of all twenty flares. This discrepancy implies that further work is needed to
understand the heating at high column mass during dMe flares. (Abridged)


title:
Towards an Efficient Use of the BLAS Library for Multilinear Tensor
  Contractions

abstract:
  Mathematical operators whose transformation rules constitute the building
blocks of a multi-linear algebra are widely used in physics and engineering
applications where they are very often represented as tensors. In the last
century, thanks to the advances in tensor calculus, it was possible to uncover
new research fields and make remarkable progress in the existing ones, from
electromagnetism to the dynamics of fluids and from the mechanics of rigid
bodies to quantum mechanics of many atoms. By now, the formal mathematical and
geometrical properties of tensors are well defined and understood; conversely,
in the context of scientific and high-performance computing, many tensor-
related problems are still open. In this paper, we address the problem of
efficiently computing contractions among two tensors of arbitrary dimension by
using kernels from the highly optimized BLAS library. In particular, we
establish precise conditions to determine if and when GEMM, the kernel for
matrix products, can be used. Such conditions take into consideration both the
nature of the operation and the storage scheme of the tensors, and induce a
classification of the contractions into three groups. For each group, we
provide a recipe to guide the users towards the most effective use of BLAS.


title: Continuous Measurement of a Non-Markovian Open Quantum System

abstract:
  Continuous quantum measurement is the backbone of various methods in quantum
control, quantum metrology, and quantum information. Here, we present a
generalized formulation of dispersive measurement of a complex quantum systems.
We describe the complex system as an open quantum system that is strongly
coupled to a non-Markovian environment, enabling the treatment of a broad
variety of natural or engineered complex systems. The system is monitored via a
probe resonator coupled to a broadband (Markovian) reservoir. Based on this
model, we derive a formalism of Stochastic Hierarchy Equations of Motion (SHEM)
describing the decoherence dynamics of the system conditioned on the
measurement record. Furthermore, we demonstrate a spectroscopy method based on
weak quantum measurement to reveal the non-Markovian nature of the environment,
which we term weak spectroscopy.


title:
The co-planarity of satellite galaxies delivered by randomly aligned
  cold mode accretion streams

abstract:
  Recent observations have shown that the majority of the Andromeda galaxy's
satellites are aligned in a thin plane. On the theoretical side it has been
proposed that galaxies acquire their gas via cold streams. In addition,
numerical simulations show that the same streams also deliver gas clumps which
could potentially develop into satellite galaxies. Assuming that cold streams
are a major source of satellite systems around galaxies we calculate the
probabilities in two different models to find a certain fraction of satellites
within a thin plane around the central galaxy of the host halo with and without
having the same sense of rotation. Using simple geometrical considerations and
adopting a random orientation of the streams we demonstrate that the vast thin
disk of satellites detected around Andromeda can naturally be explained within
this framework. In fact, without any satellite scattering, two streams would
lead to too many satellites in the thin plane, compared with the observations.
Three streams reproduce the observations very well. Natural implications from
our model are that all massive galaxies should have a thin plane of satellites
and that the satellites should naturally distribute themselves not only into a
single plane but into several inclined ones. We estimate the effect of
additional satellites accreted from random directions and find it to be of
minor relevance for a mild inflow of satellites from random directions.


title:
A renormalization group study of persistent current in a quasiperiodic
  ring

abstract:
  We propose a real-space renormalization group approach for evaluating
persistent current in a multi-channel quasiperiodic fibonacci tight-binding
ring based on a Green's function formalism. Unlike the traditional methods, the
present scheme provides a powerful tool for the theoretical description of
persistent current with a very high degree of accuracy in large periodic and
quasiperiodic rings, even in the micron scale range, which emphasizes the merit
of this work.


title: Enhanced reconstruction of weighted networks from strengths and degrees

abstract:
  Network topology plays a key role in many phenomena, from the spreading of
diseases to that of financial crises. Whenever the whole structure of a network
is unknown, one must resort to reconstruction methods that identify the least
biased ensemble of networks consistent with the partial information available.
A challenging case, frequently encountered due to privacy issues in the
analysis of interbank flows and Big Data, is when there is only local
(node-specific) aggregate information available. For binary networks, the
relevant ensemble is one where the degree (number of links) of each node is
constrained to its observed value. However, for weighted networks the problem
is much more complicated. While the naive approach prescribes to constrain the
strengths (total link weights) of all nodes, recent counter-intuitive results
suggest that in weighted networks the degrees are often more informative than
the strengths. This implies that the reconstruction of weighted networks would
be significantly enhanced by the specification of both strengths and degrees, a
computationally hard and bias-prone procedure. Here we solve this problem by
introducing an analytical and unbiased maximum-entropy method that works in the
shortest possible time and does not require the explicit generation of
reconstructed samples. We consider several real-world examples and show that,
while the strengths alone give poor results, the additional knowledge of the
degrees yields accurately reconstructed networks. Information-theoretic
criteria rigorously confirm that the degree sequence, as soon as it is
non-trivial, is irreducible to the strength sequence. Our results have strong
implications for the analysis of motifs and communities and whenever the
reconstructed ensemble is required as a null model to detect higher-order
patterns.


title: Successive Integer-Forcing and its Sum-Rate Optimality

abstract:
  Integer-forcing receivers generalize traditional linear receivers for the
multiple-input multiple-output channel by decoding integer-linear combinations
of the transmitted streams, rather then the streams themselves. Previous works
have shown that the additional degree of freedom in choosing the integer
coefficients enables this receiver to approach the performance of
maximum-likelihood decoding in various scenarios. Nonetheless, even for the
optimal choice of integer coefficients, the additive noise at the equalizer's
output is still correlated. In this work we study a variant of integer-forcing,
termed successive integer-forcing, that exploits these noise correlations to
improve performance. This scheme is the integer-forcing counterpart of
successive interference cancellation for traditional linear receivers.
Similarly to the latter, we show that successive integer-forcing is capacity
achieving when it is possible to optimize the rate allocation to the different
streams. In comparison to standard successive interference cancellation
receivers, the successive integer-forcing receiver offers more possibilities
for capacity achieving rate tuples, and in particular, ones that are more
balanced.


title:
K$\alpha$ iron line profile from accretion disks around regular and
  singular exotic compact objects

abstract:
  The nature of the super-massive black hole candidates in galactic nuclei can
be tested by analyzing the profile of the K$\alpha$ iron line observed in their
X-ray spectrum. In this paper, we consider the possibility that the spacetime
in the immediate vicinity of these objects may be described by some non vacuum
exact solutions of Einstein's equations resulting as the end-state of
gravitational collapse. The vacuum far away portion of the spacetime is
described by the Schwarzschild metric, while the interior part may be either
regular or have a naked singularity at the center. The iron line generated
around this class of objects has specific features, which can be used to
distinguish such objects from Kerr black holes. In particular, their iron line
cannot have the characteristic low-energy tail of the line generated from
accretion disks around fast-rotating Kerr black holes. We can thus conclude
that the super-massive black hole candidates whose spin parameter has been
estimated to be close to 1 assuming the Kerr background cannot be this kind of
objects.


title: Hyperbolic Hamiltonian flows and the semi-classical Poincar\'e map

abstract:
  We consider semi-excited resonances created by a periodic orbit of hyperbolic
type for Schr\"odinger type operators with a small "Planck constant". They are
defined within an analytic framework based on the semi-classical quantization
of Poincar\'e map in action-angle variables.


title:
On suspensions, and conjugacy of hyperbolic automorphisms (and of a few
  more)

abstract:
  Part 1 : We remark that the conjugacy problem for pairs of hyperbolic au-
tomorphisms of a finitely presented group (typically a free group) is
decidable. The solution that we propose uses the isomorphism problem for the
suspensions, and the study of their automorphism group.
  Part 2 : In a previous work (part 1), we remarked that the conjugacy problem
for pairs of atoroidal automorphisms of a free group was solvable by mean of
the isomorphism problem for hyperbolic groups and an orbit problem for the
automorphism group of their suspensions (i.e. their semidirect product with Z
for the relevant structural automorphism). We consider the same problem a few
more automorphisms of free groups, those that produce relatively hyperbolic
suspensions that do not split over a parabolic subgroup.


title:
The $\kappa_r$-version of the WRT$_r$-invariants, monochromatic
  3-connected blinks and evidence for a conjecture on their induced 3-manifolds

abstract:
  A {\em blink} is a plane graph with a bipartition (black, gray) of its edges.
Subtle classes of blinks are in 1-1 correspondence with closed, oriented and
connected 3-manifolds up to orientation preserving homeomorphisms
\cite{lins2013B}. Switching black and gray in a blink $B$, giving $-B$,
reverses the manifold orientation. The dual of the blink $B$ in the sphere
$\mathbb{S}^2$ is denoted by $B^ \star$. Blinks $B$ and $-B^\star$ induce the
same 3-manifold. The paper reinforces the Conjecture that if $B' \notin
\{B,-B^\star\}$, then the monochromatic 3-connected (mono3c) blinks $B$ and
$B'$ induce distinct 3-manifolds. Using homology of covers and length spectra,
we conclude the topological classification of 708 mono3c blinks that were
organized in equivalence classes by WRT-invariants in \cite{lins2007blink}. We
also present a reformulation of the combinatorial algorithm to obtain the
WRT-invariants of \cite{lins1995gca} using only the blink.


title: The chiral condensate in neutron matter

abstract:
  We calculate the chiral condensate in neutron matter at zero temperature
based on nuclear forces derived within chiral effective field theory. Two-,
three- and four-nucleon interactions are included consistently to
next-to-next-to-next-to-leading order (N3LO) of the chiral expansion. We find
that the interaction contributions lead to a modest increase of the condensate,
thus impeding the restoration of chiral symmetry in dense matter and making a
chiral phase transition in neutron-rich matter unlikely for densities that are
not significantly higher than nuclear saturation density.


title:
Finding the creatures of habit; Clustering households based on their
  flexibility in using electricity

abstract:
  Changes in the UK electricity market, particularly with the roll out of smart
meters, will provide greatly increased opportunities for initiatives intended
to change households' electricity usage patterns for the benefit of the overall
system. Users show differences in their regular behaviours and clustering
households into similar groupings based on this variability provides for
efficient targeting of initiatives. Those people who are stuck into a regular
pattern of activity may be the least receptive to an initiative to change
behaviour. A sample of 180 households from the UK are clustered into four
groups as an initial test of the concept and useful, actionable groupings are
found.


title:
Phase structure of hadronic and Polyakov-loop extended NJL model at
  finite isospin density

abstract:
  It is believed that there exists a rich phase structure of quantum
chromodynamics (QCD) at finite temperature and baryon density, namely, the
deconfinement process from hadron gas to quark-gluon plasma, the transition
from chiral symmetry breaking phase to the symmetry restoration phase, and the
color superconductivity at low temperature and high baryon density. In the
present work we study the hadron-quark phase transition by investigating the
binodal surface and extending it to finite temperature in order to mimic the
QCD phase diagram. In order to obtain these conditions we use different models
for the two possible phases, namely the quark and hadron phases. The phase
separation boundary (binodal) is determined by the Gibbs criteria for phase
equilibrium. The boundaries of the mixed phase and the related critical points
for symmetric and asymmetric matter are obtained. Isospin effects appear to be
rather significant. The critical endpoint (CEP) and the phase structure are
also studied in the Polyakov-loop extended Nambu-Jona-Lasinio model.


title:
Generators of the Gauss-Picard modular groups in three complex
  dimensions

abstract:
  In this paper, we prove that the Gauss--Picard modular group PU(3,1;Z[i])in
three complex dimensions can be generated by five given transformations: two
Heisenberg translations, two Heisenberg rotations and an involution. Indeed,
our method may work for the other higher dimensional Euclidean--Picard modular
groups.


title:
Discrepancy and integration in function spaces with dominating mixed
  smoothness

abstract:
  Optimal lower bounds for discrepancy in Besov spaces with dominating mixed
smoothness are known from the work of Triebel. Hinrichs proved upper bounds in
the plane. In this work we systematically analyse the problem, starting with a
survey of discrepancy results and the calculation of the best known constant in
Roth's Theorem. We give a larger class of point sets satisfying the optimal
upper bounds than already known from Hinrichs for the plane and solve the
problem in arbitrary dimension for certain parameters considering a celebrated
constructions by Chen and Skriganov which are known to achieve optimal
$L_2$-norm of the discrepancy function. Since those constructions are $b$-adic,
we give $b$-adic characterizations of the spaces. Finally results for
Triebel-Lizorkin and Sobolev spaces with dominating mixed smoothness and for
the integration error are concluded.


title: Convective Replica-Exchange in Ergodic Regimes

abstract:
  In a recent article (J. Comput. Chem. 2013, 34, 132-140), convective
Replica-Exchange (convective-RE) has been presented as an alternative to the
standard even-odd transition scheme. Computations on systems of various
complexity have shown that convective-RE may increase the number of replica
round-trips in temperature space with respect to the standard exchange scheme,
leading to a more effective sampling of energy basins. Moreover, it has been
shown that the method may prevent the formation of bottlenecks in the diffusive
walk of replicas through the space of temperature states. By using an ideal
temperature-RE model and a classical harmonic-oscillator RE scheme, we study
the performances of convective-RE when ergodicity is not broken and convergence
of acceptance probabilities is attained. In this dynamic regime, the round-trip
ratio between convective and standard-RE is at maximum ~1.5, a value much
smaller than that observed in non-ergodic simulations. For large acceptance
probabilities, the standard-RE outperforms convective-RE. Our observations
suggest that convective-RE can safely be used in either ergodic or non ergodic
regimes; however, convective-RE is advantageous only when bottlenecks occur in
the state-space diffusion of replicas, or when acceptance probabilities are
globally low. We also show that decoupling of the state-space dynamics of the
stick replica from the dynamics of the remaining replicas improves the
efficiency of convective-RE at low acceptance probability regimes.


title: Angular Functions with Complex Angular Momenta

abstract:
  In the study of the amplitudes for many-particle processes, and also for
processes involving particles with spin, the use is made of matrix elements of
the rotation group d^j_{\mu\nu}(z). In this paper the generalization of the
functions d^j_{\mu\nu}(z) to arbitrary arguments and indices is studied. At the
same time the functions of the second kind, analogous to Legendre functions of
the second kind, are investigated. The results obtained play an important part
in the introduction of complex angular momenta in many-particle processes.
[Added in 2013: The generalized Legendre functions considered here may be
applied as well to many other problems.]


title: Mixed Compressed Sensing Based on Random Graphs

abstract:
  Finding a suitable measurement matrix is an important topic in compressed
sensing. Though the known random matrix, whose entries are drawn independently
from a certain probability distribution, can be used as a measurement matrix
and recover signal well, in most cases, we hope the measurement matrix imposed
with some special structure. In this paper, based on random graph models, we
show that the mixed symmetric random matrices, whose diagonal entries obey a
distribution and non-diagonal entries obey another distribution, can be used to
recover signal successfully with high probability.


title: A PAC-Bayesian Tutorial with A Dropout Bound

abstract:
  This tutorial gives a concise overview of existing PAC-Bayesian theory
focusing on three generalization bounds. The first is an Occam bound which
handles rules with finite precision parameters and which states that
generalization loss is near training loss when the number of bits needed to
write the rule is small compared to the sample size. The second is a
PAC-Bayesian bound providing a generalization guarantee for posterior
distributions rather than for individual rules. The PAC-Bayesian bound
naturally handles infinite precision rule parameters, $L_2$ regularization,
{\em provides a bound for dropout training}, and defines a natural notion of a
single distinguished PAC-Bayesian posterior distribution. The third bound is a
training-variance bound --- a kind of bias-variance analysis but with bias
replaced by expected training loss. The training-variance bound dominates the
other bounds but is more difficult to interpret. It seems to suggest variance
reduction methods such as bagging and may ultimately provide a more meaningful
analysis of dropouts.


title: Possible candidate of 0^+ s\bar{s}s\bar{s} state

abstract:
  The possibility of the $0^+$ $\eta\eta$ resonance $f_0(2100)$ as a candidate
of the $Q^2\bar{Q}^2$ state $C^{ss}(36)$ is explored. The $\eta\eta$ channel of
$f_0(2100)$ is the dominant decay mode, $\eta\eta'$ channel has less decay
rate, the decay rate of the $\eta'\eta'$ channel is very small. The
$\pi\pi,\;K\bar{K},\;4\pi$ modes are at next leading order in $N_C$ expansion.
Other possible decay modes are discussed.


title: Phase growth control in low temperature PLD Co:TiO2 films by pressure

abstract:
  This paper reports on the structural and optical properties of Co-doped TiO2
thin films grown onto (0001) Al2O3 substrates by non-reactive pulsed laser
deposition (PLD) using argon as buffer gas. It is shown that by keeping
constant the substrate temperature at as low as 310 C and varying only the
background gas pressure between 7 Pa and 70 Pa, it is possible to grow either
epitaxial rutile or pure anatase thin films, as well as films with a mixture of
both polymorphs. The optical band gaps of the films are red shifted in
comparison to the values usually reported for undoped TiO2, which is consistent
with n-type doping of the TiO2 matrix. Such band gap red shift brings the
absorption edge of the Co-doped TiO2 films into the visible region, which might
favour their photocatalytic activity. Furthermore, the band gap red shift
depends on the films phase composition, increasing with the increase of the
Urbach energy for increasing rutile content.


title: 5d transition metal oxide IrO2 as a material for spin current detection

abstract:
  Devices based on a pure spin current (a flow of spin angular momentum) have
been attracting increasing attention as key ingredients for low-dissipation
electronics. To integrate such spintronics devices into charge-based
technologies, an electric detection of spin current is essential. Inverse spin
Hall effect converts a spin current into an electric voltage through spin-orbit
coupling. Noble metals such as Pt and Pd, and also Cu-based alloys, owing to
the large direct spin Hall effect, have been regarded as potential materials
for a spin-current injector. Those materials, however, are not promising as a
spin-current detector based on inverse spin Hall effect. Their spin Hall
resistivity rho_SH, representing the performance as a detector, is not large
enough mainly due to their low charge resistivity. Here we demonstrate that
heavy transition metal oxides can overcome such limitations inherent to
metal-based spintronics materials. A binary 5d transition metal oxide IrO2,
owing to its large resistivity as well as a large spin-orbit coupling
associated with 5d character of conduction electrons, was found to show a
gigantic rho_SH ~ 38 microohm cm at room temperature, one order of magnitude
larger than those of noble metals and Cu-based alloys and even comparable to
those of atomic layer thin film of W and Ta.


title:
Structural, electrical and magnetic studies of Co:SnO2 and (Co,Mo):SnO2
  films prepared by pulsed laser deposition

abstract:
  Here we report on the structural, optical, electrical and magnetic properties
of Co-doped and (Co,Mo)-codoped SnO2 thin films deposited on r-cut sapphire
substrates by pulsed laser deposition. Substrate temperature during deposition
was kept at 500 C. X-ray diffraction analysis showed that the undoped and doped
films are crystalline with predominant orientation along the [101] direction
regardless of the doping concentration and doping element. Optical studies
revealed that the presence of Mo reverts the blue shift trend observed for the
Co-doped films. For the Co and Mo doping concentrations studied, the
incorporation of Mo did not contribute to increase the conductivity of the
films or to enhance the ferromagnetic order of the Co-doped films.


title:
Adaptive Heterogeneous Multiscale Methods for immiscible two-phase flow
  in porous media

abstract:
  In this contribution we present the first formulation of a heterogeneous
multiscale method for an incompressible immiscible two-phase flow system with
degenerate permeabilities. The method is in a general formulation which
includes oversampling. We do not specify the discretization of the derived
macroscopic equation, but we give two examples of possible realizations,
suggesting a finite element solver for the fine scale and a vertex centered
finite volume method for the effective coarse scale equations. Assuming
periodicity, we show that the method is equivalent to a discretization of the
homogenized equation. We provide an a-posteriori estimate for the error between
the homogenized solutions of the pressure and saturation equations and the
corresponding HMM approximations. The error estimate is based on the results
recently achieved in [C. Canc{\`e}s, I. S. Pop, and M. Vohral\'{\i}k. An a
posteriori error estimate for vertex-centered finite volume discretizations of
immiscible incompressible two-phase flow. Math. Comp., 2014].


title: Reflected BSDEs in time-dependent convex regions

abstract:
  We prove existence and uniqueness of solutions of reflected backward
stochastic differential equations in time-dependent adapted and c\`adl\`ag
convex regions $\mathcal{D}=\{D_t;t\in[0,T]\}$. We also show that the solution
may be approximated by solutions of backward equations with reflection in
appropriately defined discretizations of $\mathcal{D}$ and by a modified
penalization method. The approximation results are new even in the
one-dimensional case.


title:
Thermal expansion of CaFe2As2: effect of cobalt doping and post-growth
  thermal treatment

abstract:
  We report thermal expansion measurements on Ca(Fe_(1-x)Co_x)_2As_2 single
crystals with different thermal treatment, with samples chosen to represent
four different ground states observed in this family. For all samples thermal
expansion is anisotropic with different signs of the in-plane and c-axis
thermal expansion coefficients in the high temperature, tetragonal phase. The
features in thermal expansion associated with the phase transitions are of
opposite signs as well, pointing to a different response of transition
temperatures to the in-plane and the c-axis stress. These features, and
consequently the inferred pressure derivatives, are very large, clearly and
substantially exceeding those in the Ba(Fe_(1-x)Co_x)_2As_2 family. For all
transitions the c-axis response is dominant.


title:
Motionless Phase Stepping in X-Ray Phase Contrast Imaging with a Compact
  Source

abstract:
  X-ray phase contrast imaging offers a way to visualize the internal
structures of an object without the need to deposit any radiation, and thereby
alleviate the main concern in x-ray diagnostic imaging procedures today.
Grating-based differential phase contrast imaging techniques are compatible
with compact x-ray sources, which is a key requirement for the majority of
clinical x-ray modalities. However, these methods are substantially limited by
the need for mechanical phase stepping. We describe an electromagnetic phase
stepping method that eliminates mechanical motion, and thus removing the
constraints in speed, accuracy and flexibility. The method is broadly
applicable to both projection and tomography imaging modes. The transition from
mechanical to electromagnetic scanning should greatly facilitate the
translation of x-ray phase contrast techniques into mainstream applications.


title: Time integration for diffuse interface models for two-phase flow

abstract:
  We propose a variant of the $\theta$-scheme for diffuse interface models for
two-phase flow, together with three new linearization techniques for the
surface tension. These involve either additional stabilizing force terms, or a
fully implicit coupling of the Navier-Stokes and Cahn-Hilliard equation. In the
common case that the equations for interface and flow are coupled explicitly,
we find a time step restriction which is very different to other two-phase flow
models and in particular is independent of the grid size. We also show that the
proposed stabilization techniques can lift this time step restriction. Even
more pronounced is the performance of the proposed fully implicit scheme which
is stable for arbitrarily large time steps. We demonstrate in a Taylor flow
application that this superior coupling between flow and interface equation can
render diffuse interface models even computationally cheaper and faster than
sharp interface models.


title: Almost-BPS solutions in multi-center Taub-NUT

abstract:
  Microstates of colinear black holes embedded in a multi-center Taub-NUT
spacetime are sought in 4 dimensions. A set of coupled ordinary partial
differential equations are obtained and solved for almost-BPS states, where
some supersymmetry is preserved in the context of N=2 supergravity in 4
dimensions. The regularity of solutions is being carefully considered and we
ensure that no CTC (closed time-like curves) are present. The larger framework
is that of 11-dimensional N=2 supergravity and the current theory is obtained
by compactifying down to 4 dimensions.


title:
Finite size effects in the correlation structure of stochastic neural
  networks: analysis of different connectivity matrices and failure of the
  mean-field theory

abstract:
  We quantify the finite size effects in a stochastic network made up of rate
neurons, for several kinds of recurrent connectivity matrices. This analysis is
performed by means of a perturbative expansion of the neural equations, where
the perturbative parameters are the intensities of the sources of randomness in
the system. In detail, these parameters are the variances of the background or
input noise, of the initial conditions and of the distribution of the synaptic
weights. The technique developed in this article can be used to study systems
which are invariant under the exchange of the neural indices and it allows us
to quantify the correlation structure of the network, in terms of pairwise and
higher order correlations between the neurons. We also determine the relation
between the correlation and the external input of the network, showing that
strong signals coming from the environment reduce significantly the amount of
correlation between the neurons. Moreover we prove that in general the
phenomenon of propagation of chaos does not occur, even in the thermodynamic
limit, due to the correlation structure of the 3 sources of randomness
considered in the model. Furthermore, we show that the propagation of chaos
does not depend only on the number of neurons in the network, but also and
mainly on the number of incoming connections per neuron. To conclude, we prove
that for special values of the parameters of the system the neurons become
perfectly correlated, a phenomenon that we have called stochastic
synchronization. These discoveries clearly prevent the use of the mean-field
theory in the description of the neural network.


title:
Nuclear Structure and Reaction Properties of Ne, Mg and Si Isotopes with
  RMF Densities

abstract:
  We have studied nuclear structure and reaction properties of Ne, Mg and Si
isotopes, using relativistic mean field densities, in the frame work of Glauber
model. Total reaction cross section $\sigma_R$ for Ne isotopes on 12C target
have been calculated at incident energy 240 MeV. The results are compared with
the experimental data and with the recent theoretical study [W. Horiuchi et
al., Phys. Rev. C, 86, 024614 (2012)]. Study of $\sigma_R$ using deformed
densities have shown a good agreement with the data. We have also predicted
total reaction cross section $\sigma_R$ for Ne, Mg and Si isotopes as
projectiles and 12C as target at different incident energies.


title: Axioms for the Lefschetz number as a lattice valuation

abstract:
  We give new axioms for the Lefschetz number based on Hadwiger's
characterization of the Euler characteristic as the unique lattice valuation on
polyhedra which takes value 1 on simplices. In the setting of maps on abstract
simplicial complexes, we show that the Lefschetz number is unique with respect
to a valuation axiom and an axiom specifying the value on a simplex. These
axioms lead naturally to the classical computation of the Lefschetz number as a
trace in homology. We then extend this approach to continuous maps of
polyhedra, assuming an extra homotopy invariance axiom. We also show that this
homotopy axiom can be weakened.


title: The 1905 Relativity Paper and the "Light Quantum"

abstract:
  In 1905 the well-known physicist Max Planck was coeditor of the Annalen der
Physik, and he accepted Einstein's paper on light quanta for publication, even
though he disliked the idea of "light quanta". Einstein's relativity paper was
received by the Annalen der Physik at the end of June 1905 and Planck was the
first scientist to notice Einstein's relativity theory and to report favorably
on it. In the 1905 relativity paper Einstein used a seemingly conventional
notion, "light complex", and he did not invoke his novel quanta of light
heuristic with respect to the principle of relativity. He chose the language
"light complex" for which no clear definition could be given. But with
hindsight, in 1905 Einstein made exactly the right choice not to mix concepts
from his quantum paper with those from his relativity paper. He focused on the
solution of his relativity problem, whose far-reaching perspectives Planck
already sensed.


title:
Shear thickening in granular suspensions: inter-particle friction and
  dynamically correlated clusters

abstract:
  We consider the shear rheology of concentrated suspensions of non-Brownian
frictional particles. The key result of our study is the emergence of a
pronounced shear-thickening regime, where frictionless particles would normally
undergo shear-thinning. We clarify that shear thickening in our simulations is
due to enhanced energy dissipation via frictional inter-particle forces.
Moreover, we evidence the formation of dynamically correlated particle-clusters
of size $\xi$, which contribute to shear thickening via an increase in
\emph{viscous} dissipation. A scaling argument gives $\eta\sim \xi^2$, which is
in very good agreement with the data.


title: On the magnetic field of bound charges current

abstract:
  Measurements of magnetic induction near an ice rod in the strong electric
field were carried out. Theoretical estimation of the magnetic induction was
made. It was found that in the average the experimental values of magnetic
induction were an order less than theoretical value. A conclusion about the
non- equivalence of magnetic fields of bound charges current and conduction
current was made. Therefore, the magnetic field near an energized conductor is
caused not directly by moving charges but by their influence on the propagation
medium. The similar effect could occur at diffusion of other particles through
the medium.


title: Avalanche localization and crossover scaling in amorphous plasticity

abstract:
  We perform large scale simulations of a two dimensional lattice model for
amorphous plasticity with random local yield stresses and long-range
quadrupolar elastic interactions. We show that as the external stress increases
towards the yielding phase transition, the scaling behavior of the avalanches
crosses over from mean-field theory to a different universality class. This
behavior is associated with strain localization, which significantly depends on
the short-range properties of the interaction kernel.


title:
Near-Optimal Encoding for Sigma-Delta Quantization of Finite Frame
  Expansions

abstract:
  In this paper we investigate encoding the bit-stream resulting from coarse
Sigma-Delta quantization of finite frame expansions (i.e., overdetermined
representations) of vectors. We show that for a wide range of finite-frames,
including random frames and piecewise smooth frames, there exists a simple
encoding algorithm ---acting only on the Sigma-Delta bit stream--- and an
associated decoding algorithm that together yield an approximation error which
decays exponentially in the number of bits used. The encoding strategy consists
of applying a discrete random operator to the Sigma-Delta bit stream and
assigning a binary codeword to the result. The reconstruction procedure is
essentially linear and equivalent to solving a least squares minimization
problem.


title:
Toda Equations and Piecewise Polynomiality for Mixed Double Hurwitz
  Numbers

abstract:
  This article introduces mixed double Hurwitz numbers, which interpolate
combinatorially between the classical double Hurwitz numbers studied by
Okounkov and the monotone double Hurwitz numbers introduced recently by
Goulden, Guay-Paquet and Novak. Generalizing a result of Okounkov, we prove
that a certain generating series for the mixed double Hurwitz numbers solves
the 2-Toda hierarchy of partial differential equations. We also prove that the
mixed double Hurwitz numbers are piecewise polynomial, thereby generalizing a
result of Goulden, Jackson and Vakil.


title:
Weak magnetism and the Mott-state of vanadium in superconducting
  Sr2VO3FeAs

abstract:
  We report neutron scattering data and DFT calculations of the stoichiometric
iron-arsenide superconductor Sr2VO3FeAs. Rietveld refinements of neutron powder
patterns confirm the ideal composition without oxygen deficiencies. Experiments
with polarized neutrons prove weak magnetic ordering in the V-sublattice of
Sr2VO3FeAs at ~ 45 K with a probable propagation vector q = (1/8,1/8,0). The
ordered moment of ~ 0.1 muB is too small to remove the V-3d bands from the
Fermi level by magnetic exchange splitting, and much smaller than predicted
from a recent LDA+U study. By using DFT calculations with a GGA+EECE functional
we recover the typical quasi-nested Fermi-surface even without magnetic moment.
From this we suggest that the V-atoms are in a Mott-state where the electronic
correlations are dominated by on-site Coulomb-repulsion which shifts the V-3d
states away from the Fermi energy. Our results are consistent with
photoemission data and clearly reveal that Sr2VO3FeAs is a typical
iron-arsenide superconductor with quasi-nested hole- and electron-like Fermi
surface sheets, and constitutes no new paradigm. We suggest that intrinsic
electron-doping through V3+/V4+ mixed valence is responsible for the absence of
SDW ordering.


title: Characterizing [h,2,1] graphs by minimal forbidden induced subgraphs

abstract:
  An undirected graph G is called a VPT graph if it is the vertex intersection
graph of a family of paths in a tree. The class of graphs which admit a VPT
representation in a host tree with maximum degree at most h is denoted by
[h,2,1]. The classes [h,2,1] are closed by taking induced subgraphs, therefore
each one can be characterized by a family of minimal forbidden induced
subgraphs. In this paper we associate the minimal forbidden induced subgraphs
for [h,2,1] which are VPT with (color) h-critical graphs. We describe how to
obtain minimal forbidden induced subgraphs from critical graphs, even more, we
show that the family of graphs obtained using our procedure is exactly the
family of VPT minimal forbidden induced subgraphs for [h,2,1]. The members of
this family together with the minimal forbidden induced subgraphs for VPT, are
the minimal forbidden induced subgraphs for [h,2,1], with $h\geq 3$. Notice
that by taking h=3 we obtain a characterization by minimal forbidden induced
subgraphs of the class VPT $\cap$ EPT=EPT $\cap$ Chordal=[3,2,2]=[3,2,1].


title: On the definition of mixed Hodge modules

abstract:
  We give some details of a simpler definition of mixed Hodge modules which has
been announced in some papers. Compared with earlier arguments, this new
definition is simplified by using Beilinson's maximal extension together with
stability by subquotients systematically.


title: On the regularity of binomial edge ideals

abstract:
  We study the regularity of binomial edge ideals. For a closed graph $G$ we
show that the regularity of the binomial edge ideal $J_G$ coincides with the
regularity of $\ini_{\lex}(J_G)$ and can be expressed in terms of the
combinatorial data of $G.$ In addition, we give positive answers to
Matsuda-Murai conjecture for some classes of graphs.


title:
Analytic results for a quantum quench from free to hard-core one
  dimensional bosons

abstract:
  It is widely believed that the stationary properties after a quantum quench
in integrable systems can be described by a generalized Gibbs ensemble (GGE),
even if all the analytical evidence is based on free theories in which the pre-
and post-quench modes are linearly related. In contrast, we consider the
experimentally relevant quench of the one-dimensional Bose gas from zero to
infinite interaction, in which the relation between modes is nonlinear, and
consequently Wick's theorem does not hold. We provide exact analytical results
for the time evolution of the dynamical density-density correlation function at
any time after the quench and we prove that its stationary value is described
by a GGE in which Wick's theorem is restored.


title: More Examples of Non-Rational Adjoint Groups

abstract:
  We give a recursive construction to produce examples of quadratic forms q_n
in the n-th power of the fundamental ideal in the Witt ring whose corresponding
adjoint groups PSO(q_n) are not stably rational. Computations of the
R-equivalence classes of adjoint classical groups by A.S. Merkurjev are used to
show that these groups are not R-trivial. This extends earlier results of A.S.
Merkurjev and P.Gille where the forms considered have non-trivial and trivial
discriminants respectively.


title:
Chisholm-Caianiello-Fubini Identities for S=1 Barut-Muzinich-Williams
  Matrices

abstract:
  The formulae of the relativistic products are found S=1
Barut-Muzinich-Williams matrices. They are analogs of the well-known
Chisholm-Caianiello-Fubini identities. The obtained results can be useful in
the higher-order calculations of the high-energy processes with S=1 particles
in the framework of the 2(2S+1) Weinberg formalism, which recently attracted
attention again. PACS numbers: 02.90.+p, 11.90.+t, 12.20.Ds


title: On Negotiation as Concurrency Primitive

abstract:
  We introduce negotiations, a model of concurrency close to Petri nets, with
multiparty negotiation as primitive. We study the problems of soundness of
negotiations and of, given a negotiation with possibly many steps, computing a
summary, i.e., an equivalent one-step negotiation. We provide a complete set of
reduction rules for sound, acyclic, weakly deterministic negotiations and show
that, for deterministic negotiations, the rules compute the summary in
polynomial time.


title:
X-ray Observations of Disrupted Recycled Pulsars: No Refuge for Orphaned
  Central Compact Objects

abstract:
  We present a Chandra X-ray survey of the disrupted recycled pulsars (DRPs),
isolated radio pulsars with P > 20 ms and B_s < 3E10 G. These observations were
motivated as a search for the immediate descendants of the approx. 10 central
compact objects (CCOs) in supernova remnants, three of which have similar
timing and magnetic properties as the DRPs, but are bright, thermal X-ray
sources consistent with minimal neutron star cooling curves. Since none of the
DPRs were detected, there is no evidence that they are "orphaned" CCOs, neutron
stars whose supernova remnants has dissipated. Upper limits on their thermal
X-ray luminosities are in the range log Lx[erg/s] = 31.8-32.8, which implies
cooling ages > 1E4 - 1E5 yr, roughly 10 times the ages of the approximately 10
known CCOs in a similar volume of the Galaxy. The order of a hundred CCO
descendants that could be detected by this method are thus either intrinsically
radio quiet, or occupy a different region of (P,B_s) parameter space from the
DRPs. This motivates a new X-ray search for orphaned CCOs among radio pulsars
with larger B-fields, which could verify the theory that their fields are
buried by fall-back of supernova ejecta, but quickly regrow to join the normal
pulsar population.