title:
A fast and accurate method to compute the mass return from multiple
  stellar populations

abstract:
  The mass returned to the ambient medium by aging stellar populations over
cosmological times sums up to a significant fraction (20% - 30% or more) of
their initial mass. This continuous mass injection plays a fundamental role in
phenomena such as galaxy formation and evolution, fueling of supermassive black
holes in galaxies and the consequent (negative and positive) feedback
phenomena, and the origin of multiple stellar populations in globular clusters.
In numerical simulations the calculation of the mass return can be time
consuming, since it requires at each time step the evaluation of a convolution
integral over the whole star formation history, so the computational time
increases quadratically with the number of time-steps. The situation can be
especially critical in hydrodynamical simulations, where different grid points
are characterized by different star formation histories, and the gas cooling
and heating times are shorter by orders of magnitude than the characteristic
stellar lifetimes. In this paper we present a fast and accurate method to
compute the mass return from stellar populations undergoing arbitrarily
complicated star formation histories. At each time-step the mass return is
calculated from its value at the previous time, and the star formation rate
over the last time-step only. Therefore in the new scheme there is no need to
store the whole star formation history, and the computational time increases
linearly with the number of time-steps.


title: Status of the NICA/MPD project

abstract:
  A general-purpose detector for studying heavy-ion collisions at the NICA
facility is under construction at JINR. The NICA/MPD physics program, basic
design requirements, and the MPD experimental setup will be described. Results
of detector simulation and the expected performance for selected observables
will be presented


title: Separable Schmidt modes of a non-separable state

abstract:
  Two-photon states entangled in continuous variables such as wavevector or
frequency represent a powerful resource for quantum information protocols in
higher-dimensional Hilbert spaces. At the same time, there is a problem of
addressing separately the corresponding Schmidt modes. We propose a method of
engineering two-photon spectral amplitude in such a way that it contains
several non-overlapping Schmidt modes, each of which can be filtered
losslessly. The method is based on spontaneous parametric down-conversion
(SPDC) pumped by radiation with a comb-like spectrum. There are many ways of
producing such a spectrum; here we consider the simplest one, namely passing
the pump beam through a Fabry-Perot interferometer. For the two-photon spectral
amplitude (TPSA) to consist of non-overlapping Schmidt modes, the crystal
dispersion dependence, the length of the crystal, the Fabry-Perot free spectral
range and its finesse should satisfy certain conditions. We experimentally
demonstrate the control of TPSA through these parameters. We also discuss a
possibility to realize a similar situation using cavity-based SPDC.


title: Higher order optical vortices and formation of speckles

abstract:
  We have experimentally generated higher order optical vortices and scattered
them through a ground glass plate that results in speckle formation. Intensity
autocorrelation measurements of speckles show that their size decreases with
increase in the order of the vortex. It implies increase in angular diameter of
the vortices with their order. The characterization of vortices in terms of
their annular bright ring also helps us to understand these observations. The
results may find applications in stellar intensity interferometry and thermal
ghost imaging.


title: Interaction Graphs: Exponentials

abstract:
  This paper is the fourth of a series exposing a systematic combinatorial
approach to Girard's Geometry of Interaction (GoI) program. The GoI program
aims at obtaining particular realisability models for linear logic that
accounts for the dynamics of cut-elimination. This fourth paper tackles the
complex issue of defining exponential connectives in this framework. For that
purpose, we use the notion of \emph{graphings}, a generalisation of graphs
which was defined in earlier work. We explain how to define a GoI for
Elementary Linear Logic (ELL) with second-order quantification, a sub-system of
linear logic that captures the class of elementary time computable functions.


title:
Quark mass dependence of Spin-Orbit force in parity-odd NN system from
  2+1 flavor QCD

abstract:
  We report our recent study of spin-orbit force between two nucleons in the
parity-odd sector from lattice QCD. To examine the quark mass dependence of
spin-orbit force, we construct it from Nambu-Bethe-Salpeter wave functions in
$^3P_0$, $^3P_1$ and $^3P_2-^3F_2$ channels calculated from lattice QCD in the
quark mass region $m_\pi$=702-411 MeV. The calculation is performed on Blue
Gene/Q at KEK by using $N_f=2+1$ PACS-CS gauge configuration generated by O(a)
improved Wilson quark action with RG improved (Iwasaki) gauge action. We find
that the potentials tend to become stronger as the quark mass decreases.


title: The M4 Core Project with HST --- I. Overview and First-Epoch

abstract:
  We present an overview of the ongoing Hubble Space Telescope large program
GO-12911. The program is focused on the core of M4, the nearest Galactic
globular cluster, and the observations are designed to constrain the number of
binaries with massive companions (black holes, neutron stars, or white dwarfs)
by measuring the ``wobble'' of the luminous (main-sequence) companion around
the center of mass of the pair, with an astrometric precision of ~50
micro-arcseconds. The high spatial resolution and stable medium-band PSFs of
WFC3/UVIS will make these measurements possible. In this work we describe: (i)
the motivation behind this study, (ii) our observing strategy, (iii) the many
other investigations enabled by this unique data set, and which of those our
team is conducting, and (iv) a preliminary reduction of the first-epoch
data-set collected on October 10, 2012.


title:
A stabilized cut finite element method for partial differential
  equations on surfaces: The Laplace-Beltrami operator

abstract:
  We consider solving the Laplace-Beltrami problem on a smooth two dimensional
surface embedded into a three dimensional space meshed with tetrahedra. The
mesh does not respect the surface and thus the surface cuts through the
elements. We consider a Galerkin method based on using the restrictions of
continuous piecewise linears defined on the tetrahedra to the surface as trial
and test functions.
  The resulting discrete method may be severely ill-conditioned, and the main
purpose of this paper is to suggest a remedy for this problem based on adding a
consistent stabilization term to the original bilinear form. We show optimal
estimates for the condition number of the stabilized method independent of the
location of the surface. We also prove optimal a priori error estimates for the
stabilized method.


title:
Investigation of the dynamical slowing down process in soft glassy
  colloidal suspensions: comparisons with supercooled liquids

abstract:
  The primary and secondary relaxation timescales of aging colloidal
suspensions of Laponite are estimated from intensity autocorrelation functions
obtained in dynamic light scattering (DLS) experiments. The dynamical slowing
down of these relaxation processes are compared with observations in fragile
supercooled liquids by establishing a one-to-one mapping between the waiting
time since filtration of a Laponite suspension and the inverse of the
temperature of a supercooled liquid that is rapidly quenched towards its glass
transition temperature. New timescales, such as the Vogel time and the Kauzmann
time, are extracted to describe the phenomenon of dynamical arrest in Laponite
suspensions. In results that are strongly reminiscent of those extracted from
supercooled liquids approaching their glass transitions, it is demonstrated
that the Vogel time calculated for each Laponite concentration is approximately
equal to the Kauzmann time, and that a strong coupling exists between the
primary and secondary relaxation processes of aging Laponite suspensions.
Furthermore, the experimental data presented here clearly demonstrates the
self-similar nature of the aging dynamics of Laponite suspensions within a
range of sample concentrations.


title: Multiscale Dictionary Learning for Estimating Conditional Distributions

abstract:
  Nonparametric estimation of the conditional distribution of a response given
high-dimensional features is a challenging problem. It is important to allow
not only the mean but also the variance and shape of the response density to
change flexibly with features, which are massive-dimensional. We propose a
multiscale dictionary learning model, which expresses the conditional response
density as a convex combination of dictionary densities, with the densities
used and their weights dependent on the path through a tree decomposition of
the feature space. A fast graph partitioning algorithm is applied to obtain the
tree decomposition, with Bayesian methods then used to adaptively prune and
average over different sub-trees in a soft probabilistic manner. The algorithm
scales efficiently to approximately one million features. State of the art
predictive performance is demonstrated for toy examples and two neuroscience
applications including up to a million features.


title:
Kinetics of random sequential adsorption of nearly spherically symmetric
  particles

abstract:
  Kinetics of random sequential adsorption (RSA) of spheres on flat,
two-dimensional surfaces is governed by a power law with exponent $-1/2$. The
study has shown that for RSA of nearly spherically symmetric particles this
exponent is $-1/3$, whereas other characteristics typically measured in RSA
simulations approach values known for spheres with the increase of symmetry of
the particles.


title: Quantum groups via cyclic quiver varieties I

abstract:
  We construct the quantized enveloping algebra of any simple Lie algebra of
type ADE as the quotient of a Grothendieck ring arising from certain cyclic
quiver varieties. In particular, the dual canonical basis of a one-half quantum
group with respect to Lusztig's bilinear form is contained in the natural basis
of the Grothendieck ring up to rescaling.
  This paper expands the categorification established by Hernandez and Leclerc
to the whole quantum groups. It can be viewed as a geometric counterpart of
Bridgeland's recent work for type ADE.


title:
Experimental linear-optics simulation of the ground state of an
  interacting quantum spin-ring

abstract:
  Critical phenomena involve a structural change in the correlations of its
constituents. These features can be employed in quantum simulators to assess
when a criticality occurred in medium-size systems, for which phase transitions
are not captured by standard thermodynamical methods. Here we demonstrate these
concepts in a photonic quantum simulator: we encode the wavefunction of the
ground state of a three-spin Ising ring by using a pair of entangled photons.
The effect of a simulated magnetic field, leading to a critical modification of
the correlation within the ring, is analysed by studying two- and three-spin
entanglement. In particular, we make a quantitative connection between the
violation of Svetlichny's inequality to the amount of three-tangle and
tripartite negativity in our ring.


title: Curvature of Hessian Manfiolds

abstract:
  We prove that, in dimensions greater than 2, the generic metric is not a
Hessian metric and find a curvature condition on Hessian metrics in dimensions
greater than 3. In particular we prove that the forms used to define the
Pontryagin classes in terms of the curvature vanish on a Hessian manifold. By
contrast all analytic Riemannian 2-metrics are Hessian metrics.


title:
New insights in gill/buccal rhythm spiking activity and CO2 sensitivity
  in pre- and post-metamorphic tadpoles (Pelophylax ridibundus)

abstract:
  Central CO2chemosensitivity is crucial for all air-breathing vertebrates and
raises the question of itsrole in ventilatory rhythmogenesis. In this study,
neurograms of ventilatory motor outputs recorded infacial nerve of
premetamorphic and postmetamorphic tadpole isolated brainstems, under normo-
andhypercapnia, are investigated using Continuous Wavelet Transform spectral
analysis for buccal activityand computation of number and amplitude of spikes
during buccal and lung activities. Buccal burstsexhibit fast oscillations
(20-30 Hz) that are prominent in premetamorphic tadpoles: they result from
thepresence in periodic time windows of high amplitude spikes. Hypercapnia
systematically decreases thefrequency of buccal rhythm in both pre- and
postmetamorphic tadpoles, by a lengthening of the interburstduration. In
postmetamorphic tadpoles, hypercapnia reduces buccal burst amplitude and
unmasks smallfast oscillations. Our results suggest a common effect of the
hypercapnia on the buccal part of the CentralPattern Generator in all tadpoles
and a possible effect at the level of the motoneuron recruitment
inpostmetamorphic tadpoles.


title: Long-term Variability in the Length of the Solar Cycle

abstract:
  The recent paucity of sunspots and the delay in the expected start of Solar
Cycle 24 have drawn attention to the challenges involved in predicting solar
activity. Traditional models of the solar cycle usually require information
about the starting time and rise time as well as the shape and amplitude of the
cycle. With this tutorial, we investigate the variations in the length of the
sunspot number cycle and examine whether the variability can be explained in
terms of a secular pattern. We identified long-term cycles in archival data
from 1610 - 2000 using median trace analyses of the cycle length and power
spectrum analyses of the (O-C) residuals of the dates of sunspot minima and
maxima. Median trace analyses of data spanning 385 years indicate a cycle
length with a period of 183 - 243 years, and a power spectrum analysis
identifies a period of 188 $\pm$ 38 years. We also find a correspondence
between the times of historic minima and the length of the sunspot cycle, such
that the cycle length increases during the time when the number of spots is at
a minimum. In particular, the cycle length was growing during the Maunder
Minimum when almost no sunspots were visible on the Sun. Our study suggests
that the length of the sunspot number cycle should increase gradually, on
average, over the next $\sim$75 years, accompanied by a gradual decrease in the
number of sunspots. This information should be considered in cycle prediction
models to provide better estimates of the starting time of each cycle.


title: The Cycle Spectrum of Claw-free Hamiltonian Graphs

abstract:
  If $G$ is a claw-free hamiltonian graph of order $n$ and maximum degree
$\Delta$ with $\Delta\geq 24$, then $G$ has cycles of at least $\min\left\{
n,\left\lceil\frac{3}{2}\Delta\right\rceil\right\}-2$ many different lengths.


title: Concluding talk: fundamental lessons and challenges from neutrinos

abstract:
  We present a concise review of the experimental developments on neutrino
mixing and their theoretical implications as presented and discussed at this
Conference. The recent data disfavour many models but the surviving ones still
span a wide range going from Anarchy (no structure, no symmetry in the neutrino
sector) to a maximum of symmetry, as for the models based on discrete
non-abelian flavour groups which can be improved following the indications from
the recent data.


title: Holographic superconductivity in the large D expansion

abstract:
  We study holographic superconductivity by expanding the equations in the
inverse of the number of spacetime dimensions D. We obtain an analytic
expression for the critical temperature as a function of the conformal
dimension of the condensate operator. Its accuracy for 3+1-dimensional
superconductors is better than 15%. The analysis reveals a simple, and
quantitative, explanation for the onset of the superconducting instability, as
well as universal features of holographic superconductivity in the large D
limit. In particular, this allows to easily compute the effects of backreaction
on the critical temperature.


title: The open cluster NGC 7142: interstellar extinction, distance and age

abstract:
  The results of medium-band photometry of 1037 stars in the area of old open
cluster NGC 7142 down to V = 20.1 mag in the Vilnius seven-colour system are
presented. Photometric results are used to classify in spectral and luminosity
classes about 80 percent of stars down to V = 18.5 mag, to identify cluster
members, to determine the main cluster parameters and to investigate the
interstellar extinction in this direction. The average extinction A_V of the
cluster is about 1.1 mag, E(B-V) = 0.35, and its distance is 2.3 kpc (the
distance modulus 11.8 mag). The age of the cluster, 3.0 Gyr, is estimated from
the intrinsic colour-magnitude diagram with individual dereddening of each star
and the Padova isochrones. The surface distribution of the extinction is shown.
The reddening of the eclipsing variable V375 Cep is found to be close to the
average reddening of the cluster. Probably, the cluster contains five red clump
giants, two asymptotic branch stars and four blue stragglers.


title: Induced Matchings in Subcubic Graphs

abstract:
  We prove that a cubic graph with $m$ edges has an induced matching with at
least $m/9$ edges. Our result generalizes a result for planar graphs due to
Kang, Mnich, and M\"{u}ller (Induced matchings in subcubic planar graphs, SIAM
J. Discrete Math. 26 (2012) 1383-1411) and solves a conjecture of Henning and
Rautenbach (Induced matchings in subcubic graphs without short cycles, to
appear in Discrete Math.).


title:
The square-kagome quantum Heisenberg antiferromagnet at high magnetic
  fields: The localized-magnon paradigm and beyond

abstract:
  We consider the spin-1/2 antiferromagnetic Heisenberg model on the
two-dimensional square-kagome lattice with almost dispersionless lowest magnon
band. For a general exchange coupling geometry we elaborate low-energy
effective Hamiltonians which emerge at high magnetic fields. The effective
model to describe the low-energy degrees of freedom of the initial frustrated
quantum spin model is the (unfrustrated) square-lattice spin-1/2 $XXZ$ model in
a $z$-aligned magnetic field. For the effective model we perform quantum Monte
Carlo simulations to discuss the low-temperature properties of the
square-kagome quantum Heisenberg antiferromagnet at high magnetic fields. We
pay special attention to a magnetic-field driven
Berezinskii-Kosterlitz-Thouless phase transition which occurs at low
temperatures.


title: Teleparallelism by inhomogeneous dark fluid

abstract:
  In this paper, we investigate $f(T)$ cosmology and find an exact solution for
$f$ which gives a Little Rip cosmology. Also, considering accelerating
cosmology with dark matter, the time-dependent solution is found. For these
cases, by using solutions obtained from $f(T)$ gravity we find expressions for
$\omega$ and $\Lambda$ defined as time functions via equivalent description in
terms of inhomogeneous fluid. This puts the question: which theoretical model
describes the observational cosmology?


title: Hardy's theorem for compact Lie groups

abstract:
  We show that Hardy's uncertainty principle can be reformulated in such a way
that it has an analogue even for compact Lie groups and symmetric spaces of
compact type.


title:
Stationary solutions for multi-dimensional Gross-Pitaevskii equation
  with double-well potential

abstract:
  In this paper we consider a non-linear Schroedinger equation with a cubic
nonlinearity and a multi-dimensional double well potential. In the
semiclassical limit the problem of the existence of stationary solutions simply
reduces to the analysis of a finite dimensional Hamiltonian system which
exhibits different behavior depending on the dimension. In particular, in
dimension 1 the symmetric stationary solution shows a standard pitchfork
bifurcation effect, while in dimension 2 and 3 new asymmetrical solutions
associated to saddle points occur. These last solutions are localized on a
single well and this fact is related to the phase transition effect observed in
Bose-Einstein condensates in periodical lattices.


title: Superluminal Propagation and Acausality of Nonlinear Massive Gravity

abstract:
  Massive gravity is an old idea: trading geometry for mass. Much effort has
been expended on establishing a healthy model, culminating in the current
ghost-free version. We summarize here our recent findings -- that it is still
untenable -- because it is locally acausal: CTC solutions can be constructed in
a small neighborhood of any event.


title: Coupling of (ultra-)relativistic atomic nuclei with photons

abstract:
  The coupling of photons with (ultra-) relativistic atomic nuclei is presented
in two particular circumstances: very high electromagnetic fields and very
short photon pulses. We consider a typical situation where the (bare) nuclei
(fully stripped of electrons) are accelerated to energies ~1TeV per nucleon
(according to the state of the art at LHC, for instance) and photon sources
like petawatt lasers \simeq1eV -radiation (envisaged by ELI-NP project, for
instance), or free-electron laser ~10keV -radiation, or synchrotron sources,
etc. In these circumstances the nuclear scale energy can be attained, with very
high field intensities. In particular, we analyse the nuclear transitions
induced by the radiation, including both one- and two-photon processes, as well
as the polarization-driven transitions which may lead to giant dipole
resonances. The nuclear (electrical) polarization concept is introduced. It is
shown that the perturbation theory for photo-nuclear reactions is applicable,
although the field intensity is high, since the corresponding interaction
energy is low and the interaction time (pulse duration) is short. It is also
shown that the description of the giant nuclear dipole resonance requires the
dynamics of the nuclear electrical polarization degrees of freedom.


title: Cosmological Applications of Pade Approximant

abstract:
  As is well known, in mathematics, any function could be approximated by the
Pad\'e approximant. The Pad\'e approximant is the best approximation of a
function by a rational function of given order. In fact, the Pad\'e approximant
often gives better approximation of the function than truncating its Taylor
series, and it may still work where the Taylor series does not converge. In the
present work, we consider the Pad\'e approximant in two issues. First, we
obtain the analytical approximation of the luminosity distance for the flat
XCDM model, and find that the relative error is fairly small. Second, we
propose several parameterizations for the equation-of-state parameter (EoS) of
dark energy based on the Pad\'e approximant. They are well motivated from the
mathematical and physical points of view. We confront these EoS
parameterizations with the latest observational data, and find that they can
work well. In these practices, we show that the Pad\'e approximant could be an
useful tool in cosmology, and it deserves further investigation.


title: Two Cases of Radial Adiabatic Motions of a Polytrope with Gamma=4/3

abstract:
  A self-gravitating sphere of polytropic gas (polytrope) is considered. The
system of equations describing radial motions of this sphere in Lagrangian
variables reduces to the only nonlinear PDE of the second order in both
variables (Lagrangian coordinate and time). The linearization of this PDE leads
to the well-known Eddington's equation of the standard model. The case of no
energy exchange between the polytrope and the outer medium is considered, that
is, polytrope's motions are adiabatic. If gamma (a ratio of the specific heats
of the gas) is 4/3 than PDE obtained allows the separation of variables. There
exist two types of solutions of the problem both describing limitless expansion
without shock wave formation. The first one is an expansion with positive total
energy, and the second one is an expansion with zero total energy. The second
solution is of an astrophysical interest. It describes the permanently
retarding expansion that, perhaps, is akin to a born of a red giant. The
stellar density in this case concentrates to the centre of the star stronger
than the density of the stationary star with the same gamma.


title:
Minimum tomography of two entangled qutrits using local measurements of
  one-qutrit SIC-POVM

abstract:
  An experimental demonstration of two-qutrit state tomography via one-qutrit
symmetric informationally complete positive operator-valued measure (SIC-POVM)
is presented. A two-qutrit state is encoded in the transversal paths of a
spontaneous parametric down-converted photon pair. A spatial light modulator
allows to implement the necessary 81 POVM elements to reconstruct the state.
The quality of the reconstruction is evaluated by comparing independent
measurements with the predicted results calculated with the reconstructed
state. Entanglement in the system is calculated via negativity and generalized
robustness from the two-qutrit reconstructed density operator.


title: A Game Semantics for Generic Polymorphism

abstract:
  Genericity is the idea that the same program can work at many different data
types. Longo, Milstead and Soloviev proposed to capture the inability of
generic programs to probe the structure of their instances by the following
equational principle: if two generic programs, viewed as terms of type $\forall
X. \, A[X]$, are equal at any given instance $A[T]$, then they are equal at all
instances. They proved that this rule is admissible in a certain extension of
System F, but finding a semantically motivated model satisfying this principle
remained an open problem.
  In the present paper, we construct a categorical model of polymorphism, based
on game semantics, which contains a large collection of generic types. This
model builds on two novel constructions:
  -- A direct interpretation of variable types as games, with a natural notion
of substitution of games. This allows moves in games A[T] to be decomposed into
the generic part from A, and the part pertaining to the instance T. This leads
to a simple and natural notion of generic strategy.
  -- A "relative polymorphic product" which expresses quantification over the
type variable X in the variable type A with respect to a "universe'" which is
explicitly given as an additional parameter B. We then solve a recursive
equation involving this relative product to obtain a universe in a suitably
"absolute" sense.
  Full Completeness for ML types (universal closures of quantifier-free types)
is proved for this model.


title:
Interpreting random forest classification models using a feature
  contribution method

abstract:
  Model interpretation is one of the key aspects of the model evaluation
process. The explanation of the relationship between model variables and
outputs is relatively easy for statistical models, such as linear regressions,
thanks to the availability of model parameters and their statistical
significance. For "black box" models, such as random forest, this information
is hidden inside the model structure. This work presents an approach for
computing feature contributions for random forest classification models. It
allows for the determination of the influence of each variable on the model
prediction for an individual instance. By analysing feature contributions for a
training dataset, the most significant variables can be determined and their
typical contribution towards predictions made for individual classes, i.e.,
class-specific feature contribution "patterns", are discovered. These patterns
represent a standard behaviour of the model and allow for an additional
assessment of the model reliability for a new data. Interpretation of feature
contributions for two UCI benchmark datasets shows the potential of the
proposed methodology. The robustness of results is demonstrated through an
extensive analysis of feature contributions calculated for a large number of
generated random forest models.


title: Grothendieck groups of the Khovanov-Kuperberg algebras

abstract:
  The aim of this note is to take benefit of the foam nature of the
Khovanov-Kuperberg algebras to compute the Grothendieck groups of their
categories of finitely generated projective modules. The computation relies on
the Hattori-Stallings trace and some geometrical properties of foams in a solid
torus.


title: Characteristics of Dispersed ZnO-Folic acid Conjugate in Aqueous Medium

abstract:
  The focus of this article is based on the aqueous dispersed state properties
of inorganic ZnO nanoparticles (average size lessthan or equal to 4 nm), their
surface modification and bio-functionalization with folic acid at physiological
pH ~ 7.5, suitable for bio-imaging and targeted therapeutic application. While
TEM studies of the ZnO nano-crystallites have been performed to estimate their
size and morphology in dry state, the band gap properties of the freshly
prepared samples, the hydrodynamic size in aqueous solution phase and the wide
fluorescence range in visible region have been investigated to establish the
fact that the sol is particularly suitable for the bio-medical purpose in the
aqueous dispersed state.
  Key words: ZnO nanoparticle; folic acid; band gap; hydrodynamic size;
fluorescence.


title: A Fourier approach to the profile decomposition in Orlicz spaces

abstract:
  This paper is devoted to the characterization of the lack of compactness of
the Sobolev embedding of $H^N(R^{2N})$ into the Orlicz space using Fourier
analysis.


title:
Time evolution of electron flow in a model diode: Non-perturbative
  analysis

abstract:
  Using a combination of Eulerian and Lagrangian variables we obtain some exact
results and good approximation schemes for the time evolution of the electron
flow from a no-current state to a final stationary current state in a planar
one-dimensional diode. The electrons can be injected externally or generated by
the cathode via field emission governed by a current-field law. The case of
equipotential electrodes and fixed injection is studied along with a positive
anode potential. When the current is fixed externally the approach to the
stationary state goes without oscillations if the initial electron velocity is
high enough and the anode can absorb the injected flow. Otherwise the
accumulated space charge creates a potential barrier which reflects the flow
and leads to its oscillations, but our method of analysis is invalid in such
conditions. In the field emission case the flow goes to its stationary state
through a train of decaying oscillations whose period is of the order of the
electron transit time, in agreement with earlier studies based on perturbation
techniques. Our approximate method does not permit very high cathode
emissivity, though the method works when the stationary current density is only
about 10% smaller than the Child-Langmuir limit.


title:
Why random matrices share universal processes with interacting particle
  systems?

abstract:
  In these lecture we explain why limiting distribution function, like the
Tracy-Widom distribution, or limit processes, like the Airy_2 process, arise
both in random matrices and interacting particle systems. The link is through a
common mathematical structure on an interlacing structure, also known as
Gelfand-Tsetlin pattern, that appears for specific models in both fields.

categories: math-ph cond-mat.stat-mech math.MP math.PR


title:
Detecting Concepts Crucial for Success in Mathematics Courses from
  Knowledge State-based Placement Data

abstract:
  We show that individual topics and skills can have a dramatic effect on the
outcomes of students in various mathematics courses at the University of
Illinois. Data from the placement program at Illinois associates a knowledge
state, a subset of 182 items and skills that a student is able to complete
successfully and repeatedly, with their final grades in a variety of courses
from college algebra through multivariate calculus. Using various conditional
probabilities and odds ratios, we classify items based on their association
with successful and unsuccessful course outcomes, showing that some skills that
are advanced for some courses are fundamental or basic to more advanced
courses. We examine the impact of specific items across the courses in the
traditional college algebra, precalculus, and calculus sequence, as well as
courses not typically covered by placement programs, such as higher calculus
courses. Visualizations of the knowledge states associated to each student are
given for some specific courses and for the entire collection of placement
courses, allowing the impact of specific topics to be examined across the
undergraduate curriculum.


title:
GLAMER Part I: A Code for Gravitational Lensing Simulations with
  Adaptive Mesh Refinement

abstract:
  A computer code is described for the simulation of gravitational lensing
data. The code incorporates adaptive mesh refinement in choosing which rays to
shoot based on the requirements of the source size, location and surface
brightness distribution or to find critical curves/caustics. A variety of
source surface brightness models are implemented to represent galaxies and
quasar emission regions. The lensing mass can be represented by point masses
(stars), smoothed simulation particles, analytic halo models, pixelized mass
maps or any combination of these. The deflection and beam distortions
(convergence and shear) are calculated by modified tree algorithm when halos,
point masses or particles are used and by FFT when mass maps are used. The
combination of these methods allow for a very large dynamical range to be
represented in a single simulation. Individual images of galaxies can be
represented in a simulation that covers many square degrees. For an individual
strongly lensed quasar, source sizes from the size of the quasar's host galaxy
(~ 100 kpc) down to microlensing scales (~ 10^-4 pc) can be probed in a self
consistent simulation. Descriptions of various tests of the code's accuracy are
given.


title:
Measurement of Higgs boson production and properties in the WW decay
  channel with leptonic final states

abstract:
  A search for the standard model Higgs boson decaying to a W-boson pair at the
LHC is reported. The event sample corresponds to an integrated luminosity of
4.9 and 19.4 inverse femtobarns collected with the CMS detector in pp
collisions at sqrt(s) = 7 and 8 TeV, respectively. The Higgs boson candidates
are selected in events with two or three charged leptons. An excess of events
above background is observed, consistent with the expectation from the standard
model Higgs boson with a mass of around 125 GeV. The probability to observe an
excess equal or larger than the one seen, under the background-only hypothesis,
corresponds to a significance of 4.3 standard deviations for m[H] = 125.6 GeV.
The observed signal cross section times the branching fraction to WW for m[H] =
125.6 GeV is 0.72+0.20-0.18 times the standard model expectation. The
spin-parity J(P)=0(+) hypothesis is favored against a narrow resonance with
J(P)=2(+) or J(P)=0(-) that decays to a W-boson pair. This result provides
strong evidence for a Higgs-like boson decaying to a W-boson pair.


title:
Polyakov-Nambu-Jona-Lasinio phase diagrams and quarkyonic phase from
  order parameters

abstract:
  We show that the magnitude of the order parameters in
Polyakov-Nambu-Jona-Lasinio (PNJL) model, given by the quark condensate and the
Polyakov loop, can be used as a criterium to clearly identify, without
ambiguities, phases and boundaries of the strongly interacting matter, namely,
the broken/restored chiral symmetry, and confinement/deconfinement regions.
This structure is represented by the projection of the order parameters in the
temperature-chemical potential plane, which allows a clear identification of
pattern changes in the phase diagram. Such a criterium also enables the
emergence of a quarkyonic phase even in the two-flavor system. We still show
that this new phase diminishes due to the influence of an additional
vector-type interaction in the PNJL phase diagrams, and is quite sensitive to
the effect of the change of the $T_0$ parameter in the Polyakov potential.
Finally, we show that the phases and boundaries constructed by our method
indicate that the order parameters should be more strongly correlated, as in
the case of entanglement PNJL (EPNJL) model. This result suggests a novel way
to pursue further investigation of new interactions between the order
parameters in order to improve the PNJL model.


title: Parabolic problems in highly oscillating thin domains

abstract:
  In this work we consider the asymptotic behavior of the nonlinear semigroup
defined by a semilinear parabolic problem with homogeneous Neumann boundary
conditions posed in a bounded region of the plane that degenerates into a line
segment when a positive parameter $\epsilon$ goes to zero (a thin domain). Here
we also allow that its boundary presents highly oscillatory behavior with
different orders and variable profile. We take thin domains possessing the same
order $\epsilon$ to the thickness and amplitude of the oscillations but
assuming different order to the period of oscillations on the top and the
bottom of the boundary. We combine methods from linear homogenization theory
and the theory on nonlinear dynamics of dissipative systems to obtain the limit
problem establishing convergence properties for the solutions. At the end we
show the upper semicontinuity of the attractors and stationary states.


title:
Spectral and Modulational Stability of Periodic Wavetrains for the
  Nonlinear Klein-Gordon Equation

abstract:
  This paper is a detailed and self-contained study of the stability properties
of periodic traveling wave solutions of the nonlinear Klein-Gordon equation
$u_{tt}-u_{xx}+V'(u)=0$, where $u$ is a scalar-valued function of $x$ and $t$,
and the potential $V(u)$ is of class $C^2$ and periodic. Stability is
considered both from the point of view of spectral analysis of the linearized
problem (spectral stability analysis) and from the point of view of wave
modulation theory (the strongly nonlinear theory due to Whitham as well as the
weakly nonlinear theory of wave packets). The aim is to develop and present new
spectral stability results for periodic traveling waves, and to make a solid
connection between these results and predictions of the (formal) modulation
theory, which has been developed by others but which we review for
completeness.


title: Intuitionistic fixed point theories over set theories

abstract:
  In this paper we show that the intuitionistic fixed point theory FiX^{i}(X)
over set theories T is a conservative extension of T if T can manipulate finite
sequences and has the full foundation schema.


title: Massive MIMO Multicasting in Noncooperative Cellular Networks

abstract:
  We study the massive multiple-input multiple-output (MIMO) multicast
transmission in cellular networks where each base station (BS) is equipped with
a large-scale antenna array and transmits a common message using a single
beamformer to multiple mobile users. We first show that when each BS knows the
perfect channel state information (CSI) of its own served users, the
asymptotically optimal beamformer at each BS is a linear combination of the
channel vectors of its multicast users. Moreover, the optimal combining
coefficients are obtained in closed form. Then we consider the imperfect CSI
scenario where the CSI is obtained through uplink channel estimation in
timedivision duplex systems. We propose a new pilot scheme that estimates the
composite channel which is a linear combination of the individual channels of
multicast users in each cell. This scheme is able to completely eliminate pilot
contamination. The pilot power control for optimizing the multicast beamformer
at each BS is also derived. Numerical results show that the asymptotic
performance of the proposed scheme is close to the ideal case with perfect CSI.
Simulation also verifies the effectiveness of the proposed scheme with finite
number of antennas at each BS.


title:
Numerical integration of H\"older continuous, absolutely convergent
  Fourier-, Fourier cosine-, and Walsh series

abstract:
  We introduce quasi-Monte Carlo rules for the numerical integration of
functions $f$ defined on $[0,1]^s$, $s \ge 1$, which satisfy the following
properties: the Fourier-, Fourier cosine- or Walsh coefficients of $f$ are
absolutely summable and $f$ satisfies a H\"older condition of order $\alpha$,
for some $0 < \alpha \le 1$. We show a convergent rate of the integration error
of order $\max((s-1) N^{-1/2}, s^{\alpha/2} N^{-\alpha} )$. The construction of
the quadrature points is explicit and is based on Weil sums.


title:
Proof search in multi-succedent sequent calculi for intuitionistic logic
  under the Schuette's schema

abstract:
  Following G. Mints(Kluwer 2000 and draft 2013), we present terminating and
bicomplete proof searches in multi-succedent sequent calculi for intuitionistic
propositional logic, fragments of intuitionistic predicate logic and full
intuitionistic predicate logic in the spirit of Schuette's schema.


title: Extremal Aging For Trap Models

abstract:
  In the seminal work [5], Ben Arous and \v{C}ern\'y give a general
characterization of aging for trap models in terms of $\alpha$-stable
subordinators with $\alpha \in (0,1)$. Some of the important examples that fall
into this universality class are Random Hopping Time (RHT) dynamics of Random
Energy Model (REM) and $p$-spin models observed on exponential time scales. In
this paper, we explain a different aging mechanism in terms of {\it extremal
processes} that can be seen as the extension of $\alpha$-stable aging to the
case $\alpha=0$. We apply this mechanism to the RHT dynamics of the REM for a
wide range of temperature and time scales. The other examples that exhibit
extremal aging include the Sherrington Kirkpatrick (SK) model and $p$-spin
models [6, 9], and biased random walk on critical Galton-Watson trees
conditioned to survive [11].


title:
The Influence of Galactic Cosmic Rays on Ion-Neutral Hydrocarbon
  Chemistry in the Upper Atmospheres of Free-Floating Exoplanets

abstract:
  Cosmic rays may be linked to the formation of volatiles necessary for
prebiotic chemistry. We explore the effect of cosmic rays in a
hydrogen-dominated atmosphere, as a proof-of-concept that ion-neutral chemistry
may be important for modelling hydrogen-dominated atmospheres. In order to
accomplish this, we utilize Monte Carlo cosmic ray transport models with
particle energies of $10^6$ eV $< E < 10^{12}$ eV in order to investigate the
cosmic ray enhancement of free electrons in substellar atmospheres. Ion-neutral
chemistry is then applied to a Drift-Phoenix model of a free-floating giant gas
planet. Our results suggest that the activation of ion-neutral chemistry in the
upper atmosphere significantly enhances formation rates for various species,
and we find that C$_2$H$_2$, C$_2$H$_4$, NH$_3$, C$_6$H$_6$ and possibly
C$_{10}$H are enhanced in the upper atmospheres because of cosmic rays. Our
results suggest a potential connection between cosmic ray chemistry and the
hazes observed in the upper atmospheres of various extrasolar planets.
Chemi-ionization reactions are briefly discussed, as they may enhance the
degree of ionization in the cloud layer.


title:
Expected velocity anomaly for the Earth flyby of Juno spacecraft on
  October 9, 2013

abstract:
  The so-called flyby anomaly is a yet unexplainable velocity jump measured at
several Earth flybys of spacecraft. Known physical effects could be excluded as
source of this anomaly. In order to model a possible new physical effect,
empirical equations were proposed by Busack (2007) and Anderson et al. (2007),
which gave quite good description of all measured anomalies. Some theories were
suggested deriving the Anderson formula or a similar one. The recent two Earth
flybys of the spacecraft Rosetta showed no measurable anomaly, although the
Anderson formula predicted distinct effects for both flybys. The Busack formula
predicted the null results, so the notion of a possibly correct formula or of
an error of the older measuring software was supported. The forthcoming Earth
flyby of Juno gives a good opportunity to decide this question or give rise to
enhanced theory, because the orbit parameters are very similar to earlier
flybys with notable effects. In this article, the flyby anomaly according to
the Busack equation will be predicted to be about -7mm/s in contrast to the
value after the Anderson equation and similar ones with distinct positive value
of the order of +6mm/s.


title: Higgs-Like Field and Extra Dimensions

abstract:
  We study the origin of the Higgs field in the framework of the universal
extra dimensions. It is shown that a Higgs-like Lagrangian can be extracted
from a metric of an extra space. The way to distinguish our model and the
Standard Model is discussed.


title: On the number of coverings of the sphere ramified over given points

abstract:
  We present the generating function for the numbers of isomorphism classes of
coverings of the two-dimensional sphere by the genus $g$ compact oriented
surface not ramified outside of a given set of $m+1$ points in the target,
fixed ramification type over one point, and arbitrary ramification types over
the remaining $m$ points. We present the genus expansion of this generating
function and prove, that the generating function of coverings of genus $0$
satisfies some system of differential equations. We show that this generating
function is a specialization of the function from paper \cite{GJ} and,
therefore, satisfies the KP-hierarchy.


title:
ADI iteration for Lyapunov equations: a tangential approach and adaptive
  shift selection

abstract:
  A new version of the alternating directions implicit (ADI) iteration for the
solution of large-scale Lyapunov equations is introduced. It generalizes the
hitherto existing iteration, by incorporating tangential directions in the way
they are already available for rational Krylov subspaces. Additionally, first
strategies to adaptively select shifts and tangential directions in each
iteration are presented. Numerical examples emphasize the potential of the new
results.


title: On the number of graphs without large cliques

abstract:
  In 1976 Erdos, Kleitman and Rothschild determined the number of graphs
without a clique of size $\ell$. In this note we extend their result to the
case of forbidden cliques of increasing size. More precisely we prove that for
$\ell_n \le \frac12(\log n)^{1/4}$ there are
$$2^{(1-1/(\ell_n-1))n^2/2+o(n^2/\ell_n)}$$ $K_{\ell_n}$-free graphs of order
$n$. Our proof is based on the recent hypergraph container theorems of Saxton,
Thomason and Balogh, Morris, Samotij, in combination with a theorem of Lovasz
and Simonovits.


title:
Absorption cross section and Hawking radiation of the electromagnetic
  field with Weyl corrections

abstract:
  We have investigated the absorption cross section and the Hawking radiation
of electromagnetic field with Weyl correction in the background of a
four-dimensional Schwarzschild black hole spacetime. Our results show that the
properties of the absorption cross section and the Hawking radiation depend not
only on the Weyl correction parameter, but also on the parity of the
electromagnetic field, which is quite different from those of the usual
electromagnetic field without Weyl correction in the four-dimensional
spacetime. With increase of Weyl correction parameter, the absorption
probability, the absorption cross section, the power emission spectra and the
luminosity of Hawking radiation decreases with Weyl correction parameter for
the odd-parity electromagnetic field and increases with the event-parity
electromagnetic field.


title: Asymptotics of Partial Density Functions for Divisors

abstract:
  We study the asymptotic behaviour of the partial density function associated
to sections of a positive hermitian line bundle that vanish to a particular
order along a fixed divisor $Y$. Assuming the data in question is invariant
under an $S^1$-action (locally around $Y$) we prove that this density function
has a distributional asymptotic expansion that is in fact smooth upon passing
to a suitable real blow-up. Moreover we recover the existence of the "forbidden
region" $R$ on which the density function is exponentially small, and prove
that it has an "error-function" behaviour across the boundary $\partial R$. As
an illustrative application, we use this to study a certain natural function
that can be associated to a divisor in a K\"ahler manifold.


title: Case-Based Merging Techniques in OAKPLAN

abstract:
  Case-based planning can take advantage of former problem-solving experiences
by storing in a plan library previously generated plans that can be reused to
solve similar planning problems in the future. Although comparative worst-case
complexity analyses of plan generation and reuse techniques reveal that it is
not possible to achieve provable efficiency gain of reuse over generation, we
show that the case-based planning approach can be an effective alternative to
plan generation when similar reuse candidates can be chosen.


title:
Optimality of Operator-Like Wavelets for Representing Sparse AR(1)
  Processes

abstract:
  It is known that the Karhunen-Lo\`{e}ve transform (KLT) of Gaussian
first-order auto-regressive (AR(1)) processes results in sinusoidal basis
functions. The same sinusoidal bases come out of the independent-component
analysis (ICA) and actually correspond to processes with completely independent
samples. In this paper, we relax the Gaussian hypothesis and study how
orthogonal transforms decouple symmetric-alpha-stable (S$\alpha$S) AR(1)
processes. The Gaussian case is not sparse and corresponds to $\alpha=2$, while
$0<\alpha<2$ yields processes with sparse linear-prediction error. In the
presence of sparsity, we show that operator-like wavelet bases do outperform
the sinusoidal ones. Also, we observe that, for processes with very sparse
increments ($0<\alpha\leq 1$), the operator-like wavelet basis is
indistinguishable from the ICA solution obtained through numerical
optimization. We consider two criteria for independence. The first is the
Kullback-Leibler divergence between the joint probability density function
(pdf) of the original signal and the product of the marginals in the
transformed domain. The second is a divergence between the joint pdf of the
original signal and the product of the marginals in the transformed domain,
which is based on Stein's formula for the mean-square estimation error in
additive Gaussian noise. Our framework then offers a unified view that
encompasses the discrete cosine transform (known to be asymptotically optimal
for $\alpha=2$) and Haar-like wavelets (for which we achieve optimality for
$0<\alpha\leq1$).


title: Unconventional research in USSR and Russia: short overview

abstract:
  This work briefly surveys unconventional research in Russia from the end of
the 19th until the beginning of the 21th centuries in areas related to
generation and detection of a 'high-penetrating' emission of non-biological
origin. The overview is based on open scientific and journalistic materials.
The unique character of this research and its history, originating from
governmental programs of the USSR, is shown. Relations to modern studies on
biological effects of weak electromagnetic emission, several areas of
bioinformatics and theories of physical vacuum are discussed.


title: Localization of discrete time quantum walks on the glued trees

abstract:
  In this paper, we consider the time averaged distribution of discrete time
quantum walks on the glued trees. In order to analyse the walks on the glued
trees, we consider a reduction to the walks on path graphs. Using a spectral
analysis of the Jacobi matrices defined by the corresponding random walks on
the path graphs, we have spectral decomposition of the time evolution operator
of the quantum walks. We find significant contributions of the eigenvalues $\pm
1$ of the Jacobi matrices to the time averaged limit distribution of the
quantum walks. As a consequence we obtain lower bounds of the time averaged
distribution.


title: Exact interior solutions in (2 + 1) dimensional spacetime

abstract:
  We provide a new class of exact solutions for the interior in (2 + 1)
dimensional spacetime. The solutions obtained for the perfect fluid model both
with and without cosmological constant ($\Lambda$) are found to be regular and
singularity free. It assume very simple analytical forms that help us to study
the various physical properties of the configuration. Solutions without
$\Lambda$ are found to be physically acceptable.


title:
Rapid Oscillatory quintessence with variable equation of state parameter
  in non minimal derivative coupling model

abstract:
  The rapid oscillating scalar field is considered as the quintessence in the
framework of nonminimal kinetic coupling model. The scalar field behaves like a
perfect fluid with a variable equation of state parameter which can be
expressed as a function of the Hubble parameter. This feature enables us to
study its evolution via continuity equation.
  The scalar field may behave as dark energy in the present epoch, while it
behaves like dark matter in the future. This characteristic allows the
occurrence of a decelerated expansion after the present acceleration, without
invoking any interaction. The model is also studied in the presence of an
interaction between dark sectors alleviating the coincidence problem. The
stability of the model is investigated and the stable attractor solutions are
studied.


title:
M\"ossbauer studies of the peculiar magnetism in parent compounds of the
  iron-based superconductors

abstract:
  A review of the magnetism in the parent compounds of the iron-based
superconductors is given based on the transmission Moessbauer spectroscopy of
57Fe and 151Eu. It was found that the 3d magnetism is of the itinerant
character with varying admixture of the spin-polarized covalent bonds. For the
122 compounds a longitudinal spin density wave (SDW) develops. In the case of
the EuFe2As2 a divalent europium orders antiferromagnetically at much lower
temperature as compared to the onset of SDW. These two magnetic systems remain
almost uncoupled one to another. For the non-stoichiometric Fe(1+x)Te parent of
the 11 family one has a transversal SDW and magnetic order of the interstitial
iron with relatively high and localized magnetic moments. These two systems are
strongly coupled one to another. For the grand parent of the iron-based
superconductors FeAs one observes two mutually orthogonal phase-related
transversal SDW on the iron sites. There are two sets of such spin arrangements
due to two crystallographic iron sites. The FeAs exhibits the highest covalency
among compounds studied, but it has still a metallic character.


title: The distance to the young cluster NGC 7129 and its age

abstract:
  The dust cloud TGU H645 P2 and embedded in it young open cluster NGC 7129 are
investigated using the results of medium-band photometry of 159 stars in the
Vilnius seven-colour system down to V = 18.8 mag. The photometric data were
used to classify about 50 percent of the measured stars in spectral and
luminosity classes. The extinction A_V vs. distance diagram for the 20x20
arcmin area is plotted for 155 stars with two-dimensional classification from
the present and the previous catalogues. The extinction values found range
between 0.6 and 3.4 mag. However, some red giants, located in the direction of
the dense parts of the cloud, exhibit the infrared extinction equivalent up to
A_V = 13 mag. The distance to the cloud (and the cluster) is found to be 1.15
kpc (the true distance modulus 10.30 mag). For determining the age of NGC 7129,
a luminosity vs. temperature diagram for six cluster members of spectral
classes B3 to A1 was compared with the Pisa pre-main-sequence evolution tracks
and the Palla birthlines. The cluster can be as old as about 3 Myr, but star
forming continues till now as witnessed by the presence in the cloud of many
younger pre-main-sequence objects identified with photometry from 2MASS,
Spitzer and WISE infrared surveys.


title: Fermions Tunneling from Charged anti-de Sitter Black Holes

abstract:
  We study Hawking radiation as a phenomenon of tunneling through event
horizons of charged torus-like as well as dilaton black holes involving
cosmological constant based on Kerner and Mann's formulation. We obtain
tunneling probabilities as well as Hawking's emission temperature of outgoing
charged particles by applying the semiclassical WKB approximation to the
general covariant Dirac equation. The graphical behavior of Hawking temperature
and horizon radius is investigated. We find results consistent with those
already given in literature.


title: Comments on the Starobinsky Model of Inflation and its Descendants

abstract:
  We point out that the ability of some models of inflation, such as Higgs
inflation and the universal attractor models, in reproducing the available data
is due to their relation to the Starobinsky model of inflation. For large field
values, where the inflationary phase takes place, all these classes of models
are indeed identical to the Starobinsky model. Nevertheless, the inflaton is
just an auxiliary field in the Jordan frame of the Starobinsky model and this
leads to two important consequences: first, the inflationary predictions of the
Starobinsky model and its descendants are slightly different (albeit not
measurably); secondly the theories have different small-field behaviour,
leading to different ultra-violet cut-off scales. In particular, one
interesting descendant of the Starobinsky model is the non-minimally- coupled
quadratic chaotic inflation. Although the standard quadratic chaotic inflation
is ruled out by the recent Planck data, its non-minimally coupled version is in
agreement with observational data and valid up to Planckian scales.


title: Graphene Hall bar with an asymmetric pn-junction

abstract:
  We investigated the magnetic field dependence of the Hall and the bend
resistances in the ballistic regime for a single layer graphene Hall bar
structure containing a pn-junction. When both regions are n-type the Hall
resistance dominates and Hall type of plateaus are formed. These plateaus occur
as a consequence of the restriction on the angle imposed by Snell's law
allowing only electrons with a certain initial angles to transmit though the
potential step. The size of the plateau and its position is determined by the
position of the potential interface as well as the value of the applied
potential. When the second region is p-type the bend resistance dominates which
is asymmetric in field due to the presence of snake states. Changing the
position of the pn-interface in the Hall bar strongly affects these states and
therefore the bend resistance is also changed. Changing the applied potential
we observe that the bend resistance exhibits a peak around the
charge-neutrality point (CNP) which is independent of the position of the
pn-interface, while the Hall resistance shows a sign reversal when the CNP is
crossed, which is in very good agreement with a recent experiment [J. R.
Williams et al., Phys. Rev. Lett. 107, 046602(2011)].


title: On Lie Groups and The Theory of Complex Variables

abstract:
  In this note we envisage the relation existing between the Lie Groups and the
Theory of Complex Variables. In particular, it is shown that the dimensions of
the irreducibles representations of $SU(N)$ may be written in terms of the
Eisenstein integers and an identity is built up between the imaginary parts of
the dimensions of the irreducible representations of the Lie Groups $SU(3)$ and
$Sp(4)$.


title:
Kinetic theory of chiral relativistic plasmas and energy density of
  their gauge collective excitations

abstract:
  We use the recently developed kinetic theory with Berry curvature to describe
the fermions and antifermions of a chiral relativistic plasma. We check that
this transport approach allows to reproduce the chiral anomaly equation of
relativistic quantum field theory at finite temperature. We also check that it
allows to describe the anomalous gauge polarization tensor that appears in the
Hard Thermal (and/or Dense) effective field theory. We also construct an energy
density associated to the gauge collective modes of the chiral relativistic
plasma, valid in the case of small couplings or weak fields, which can be the
basis for the study of their dynamical evolution.


title:
Some Infinite Dimensional Representations of Reductive Groups with
  Frobenius Maps

abstract:
  In this paper we construct certain irreducible infinite dimensional
representations of algebraic groups with Frobenius maps. In particular, a few
classical results of Steinberg and Deligne & Lusztig on complex representations
of finite groups of Lie type are extended to reductive algebraic groups with
Frobenius maps.


title:
Yao's millionaires' problem and decoy-based public key encryption by
  classical physics

abstract:
  We use various laws of classical physics to offer several solutions of Yao's
millionaires' problem without using any one-way functions. We also describe
several informationally secure public key encryption protocols, i.e., protocols
secure against passive computationally unbounded adversary. This introduces a
new paradigm of decoy-based cryptography, as opposed to "traditional"
complexity-based cryptography. In particular, our protocols do not employ any
one-way functions.

categories: cs.CR physics.class-ph physics.comp-ph physics.pop-ph


title: Some quantitative versions of Ratner's mixing estimates

abstract:
  We give explicit versions for some of Ratner's estimates on the decay of
matrix coefficients of SL(2,R)-representations.


title: Interacting two-component fluid models with varying EoS parameter

abstract:
  In this paper, we consider Universe filled with two-component fluid. We study
two different models. In the first model we assume barotropic fluid with the
linear equation of state as the first component of total fluid. In the second
model we assume Van der Waals gas as the first component of total fluid. In
both models, the second component assumed generalized ghost dark energy. We
consider also interaction between component and discuss, numerically,
cosmological quantities for two different parametrization of EoS which varies
with time. We consider this as a toy model of our Universe. We fix parameters
of the model by using generalized second law of thermodynamics. Comparing our
results with some observational data suggests interacting barotropic fluid with
EoS parameter $\omega(t)=\omega_{0}\cos(tH)+\omega_{1}t\frac{\dot{H}}{H}$ and
generalized ghost dark energy as an appropriate model to describe our Universe.


title:
Local integrands for the five-point amplitude in planar N=4 SYM up to
  five loops

abstract:
  Integrands for colour ordered scattering amplitudes in planar N=4 SYM are
dual to those of correlation functions of the energy-momentum multiplet of the
theory. The construction can relate amplitudes with different numbers of legs.
  By graph theory methods the integrand of the four-point function of
energy-momentum multiplets has been constructed up to six loops in previous
work. In this article we extend this analysis to seven loops and use it to
construct the full integrand of the five-point amplitude up to five loops, and
in the parity even sector to six loops.
  All results, both parity even and parity odd, are obtained in a concise local
form in dual momentum space and can be displayed efficiently through graphs. We
have verified agreement with other local formulae both in terms of
supertwistors and scalar momentum integrals as well as BCJ forms where those
exist in the literature, i.e. up to three loops.
  Finally we note that the four-point correlation function can be extracted
directly from the four-point amplitude and so this uncovers a direct link from
four- to five-point amplitudes.


title: Bilayer graphene Hall bar with a pn-junction

abstract:
  We investigate the magnetic field dependence of the Hall and the bend
resistances for a ballistic Hall bar structure containing a pn-junction
sculptured from a bilayer of graphene. The electric response is obtained using
the billiard model and we investigate the cases of bilayer graphene with and
without a band gap. Two different conduction regimes are possible: $i$) both
sides of the junction have the same carrier type, and $ii$) one side of the
junction is n-type while the other one is p-type. The first case shows Hall
plateau-like features in the Hall resistance that fade away as the band gap
opens. The second case exhibits a bend resistance that is asymmetric in
magnetic field as a consequence of snake states along the pn-interface, where
the maximum is shifted away from zero magnetic field.


title: Spectroscopy of snake states using a graphene Hall bar

abstract:
  An approach to observe snake states in a graphene Hall bar containing a
pn-junction is proposed. The magnetic field dependence of the bend resistance
in a ballistic graphene Hall bar structure containing a tilted pn-junction
oscillates as a function of applied magnetic field. We show that each
oscillation is due to a specific snake state that moves along the pn-interface.
Furthermore depending on the value of the magnetic field and applied potential
we can control the lead in which the electrons will end up and hence control
the response of the system.


title: On $a^n+bn$ modulo $m$

abstract:
  Let $a$ and $m>0$ be integers. We show that for any integer $b$ relatively
prime to $m$, the set $\{a^n+bn:\ n=1,\ldots,m^2\}$ contains a complete system
of residues modulo $m$. We also pose several conjectures for further research;
for example, we conjecture that any integer $n>1$ can be written as $k+m$ with
$2^k+m$ prime, where $k$ and $m$ are positive integers.


title: Optimally Convergent Quantum Jump Expansion

abstract:
  A method for deriving accurate analytic approximations for Markovian open
quantum systems was recently introduced in [F. Lucas and K. Hornberger, Phys.
Rev. Lett. 110, 240401 (2013)]. Here, we present a detailed derivation of the
underlying non-perturbative jump expansion, which involves an adaptive
resummation to ensure optimal convergence. Applying this to a set of exemplary
master equations, we find that the resummation typically leads to convergence
within the lowest two to five orders. Besides facilitating analytic
approximations, the optimal jump expansion thus provides a numerical scheme for
the efficient simulation of open quantum systems.


title:
Entanglement negativity via replica trick: a Quantum Monte Carlo
  approach

abstract:
  Motivated by recent developments in conformal field theory (CFT), we devise a
Quantum Monte Carlo (QMC) method to calculate the moments of the partially
transposed reduced density matrix at finite temperature. These are used to
construct scale invariant combinations that are related to the negativity, a
true measure of entanglement for two intervals embedded in a chain. These
quantities can serve as witnesses of criticality. In particular, we study
several scale invariant combinations of the moments for the 1D hard-core boson
model. For two adjacent intervals unusual finite size corrections are present,
showing parity effects that oscillate with a filling dependent period. These
are more pronounced in the presence of boundaries. For large chains we find
perfect agreement with CFT. Oppositely, for disjoint intervals corrections are
more severe and CFT is recovered only asymptotically. Furthermore, we provide
evidence that their exponent is the same as that governing the corrections of
the mutual information. Additionally we study the 1D Bose-Hubbard model in the
superfluid phase. Remarkably, the finite-size effects are smaller and QMC data
are already in impressive agreement with CFT at moderate large sizes.


title:
Hodge-theoretic splitting mechanisms for projective maps (in appendix, a
  letter from P. Deligne)

abstract:
  According to the decomposition and relative hard Lefschetz theorems, given a
projective map of complex quasi projective algebraic varieties and a relatively
ample line bundle, the rational intersection cohomology groups of the domain of
the map split into various direct summands. While the summands are canonical,
the splitting is certainly not, as the choice of the line bundle yields at
least three different splittings by means of three mechanisms in a triangulated
category introduced by Deligne. It is known that these three choices yield
splittings of mixed Hodge structures. In this paper, we use the relative hard
Lefschetz theorem and elementary linear algebra to construct five distinct
splittings, two of which seem to be new, and to prove that they are splittings
of mixed Hodge structures.


title: Ray-tracing in pseudo-complex General Relativity

abstract:
  Motivated by possible observations of the black hole candidate in the center
of our galaxy and the galaxy M87, ray-tracing methods are applied to both
standard General Relativity (GR) and a recently proposed extension, the
pseudo-complex General Relativity (pc-GR). The correction terms due to the
investigated pc-GR model lead to slower orbital motions close to massive
objects. Also the concept of an innermost stable circular orbit (ISCO) is
modified for the pc-GR model, allowing particles to get closer to the central
object for most values of the spin parameter $a$ than in GR. Thus, the
accretion disk, surrounding a massive object, is brighter in pc-GR than in GR.
Iron K$\alpha$ emission line profiles are also calculated as those are good
observables for regions of strong gravity. Differences between the two theories
are pointed out.


title: Axioms of Adaptivity

abstract:
  This paper aims first at a simultaneous axiomatic presentation of the proof
of optimal convergence rates for adaptive finite element methods and second at
some refinements of particular questions like the avoidance of (discrete) lower
bounds, inexact solvers, inhomogeneous boundary data, or the use of equivalent
error estimators. Solely four axioms guarantee the optimality in terms of the
error estimators.
  Compared to the state of the art in the temporary literature, the
improvements of this article can be summarized as follows: First, a general
framework is presented which covers the existing literature on optimality of
adaptive schemes. The abstract analysis covers linear as well as nonlinear
problems and is independent of the underlying finite element or boundary
element method. Second, efficiency of the error estimator is neither needed to
prove convergence nor quasi-optimal convergence behavior of the error
estimator. In this paper, efficiency exclusively characterizes the
approximation classes involved in terms of the best-approximation error and
data resolution and so the upper bound on the optimal marking parameters does
not depend on the efficiency constant. Third, some general quasi-Galerkin
orthogonality is not only sufficient, but also necessary for the $R$-linear
convergence of the error estimator, which is a fundamental ingredient in the
current quasi-optimality analysis due to Stevenson 2007. Finally, the general
analysis allows for equivalent error estimators and inexact solvers as well as
different non-homogeneous and mixed boundary conditions.


title: Circular-arc hypergraphs: Rigidity via Connectedness

abstract:
  A circular-arc hypergraph $H$ is a hypergraph admitting an arc ordering, that
is, a circular ordering of the vertex set $V(H)$ such that every hyperedge is
an arc of consecutive vertices. An arc ordering is tight if, for any two
hyperedges $A$ and $B$ such that $A$ is a nonempty subset of $B$ and $B$ is not
equal to $V(H)$, the corresponding arcs share a common endpoint. We give
sufficient conditions for $H$ to have, up to reversing, a unique arc ordering
and a unique tight arc ordering. These conditions are stated in terms of
connectedness properties of $H$.
  It is known that $G$ is a proper circular-arc graph exactly when its closed
neighborhood hypergraph $N[G]$ admits a tight arc ordering. We explore
connectedness properties of $N[G]$ and prove that, if $G$ is a connected,
twin-free, proper circular-arc graph with non-bipartite complement, then $N[G]$
has, up to reversing, a unique arc ordering. If the complement of $G$ is
bipartite and connected, then $N[G]$ has, up to reversing, two tight arc
orderings. As a corollary, we notice that in both of the two cases $G$ has an
essentially unique intersection representation. The last result also follows
from the work by Deng, Hell, and Huang based on a theory of local tournaments.


title:
A reassessment of the redshift distribution and physical properties of
  luminous (sub-)millimetre galaxies

abstract:
  Motivated by the current controversy over the redshift distribution and
physical properties of luminous (sub-)mm sources, we have undertaken a new
study of the brightest sample of unlensed (sub-)mm sources with pre-ALMA
interferometric follow-up in the COSMOS field. Exploiting the very latest
multi-frequency supporting data, we find that this sample displays a redshift
distribution indistinguishable from that of the lensed sources uncovered with
the South Pole Telescope (SPT), with z_median ~ 3.5. We also find that, over
the redshift range z ~ 2-6 the median stellar mass of the most luminous
(sub-)mm sources is M_* ~ 3 * 10^11 M_odot, yielding a typical specific
star-formation rate sSFR ~ 3 Gyr^-1. Consistent with recent ALMA and SMA
studies, we confirm that source blending is not a serious issue in the study of
luminous (sub-)mm sources uncovered by ground-based, single-dish surveys; only
~ 10-15% of bright (S_850 ~ 5 - 10 mJy) (sub-)mm sources arise from significant
(i.e. >20%) blends, and so our conclusions are largely unaffected by whether we
adopt the original single-dish mm/sub-mm flux-densities/positions, or the
interferometric data. Our results suggest that apparent disagreements over the
redshift distribution of (sub-)mm sources are a result of "down-sizing" in
dust-enshrouded star-formation, consistent with existing knowledge of the
star-formation histories of massive galaxies. They also indicate that extreme
star-forming galaxies at high redshift are, on average, subject to the same
star-formation rate-limiting processes as less luminous objects, and lie on the
"main sequence" of star-forming galaxies at z>3.


title: Fermion mass mixing in vacuum

abstract:
  Renormalization group procedure for effective particles (RGPEP) is applied to
a theory of fermions that interact only through mass mixing terms in their
Hamiltonian. Problems with virtual pair production in vacuum are avoided by
using the front form of Hamiltonian dynamics. Masses and states of physical
fermions emerge at the end of a calculation that is carried out exactly
irrespective of the strength of the mass mixing terms. An a priori infinite set
of renormalization group equations for all momentum modes of fermion quantum
fields is reduced to just one equation for a two-by-two mass matrix. In
distinction from scalars, fermions never become tachyons but appear chirally
rotated when the mass mixing interaction term is sufficiently strong.


title: The BICEP2 data and a single Higgs-like interacting tachyonic field

abstract:
  It is proposed that the recently announced BICEP2 value of tensor-to scalar
ratio $r\sim0.2$ can be explained as containing an extra contribution from the
recent acceleration of the universe. In fact this contribution, being robust,
recent and of much longer duration (by a large order of magnitude) may dominate
the contribution from the inflationary origin. In a possible scenario, matter
(dark or baryonic) and radiation etc. can emerge from a single Higgs-like
tachyonic scalar field in the universe through a physical mechanism not yet
fully known to us. The components interact among themselves to achieve the
thermodynamical equilibrium in the evolution of the universe. The field
potential for the present acceleration of the universe would give a boost to
the amplitude of the tensor fluctuations of gravity waves generated by the
early inflation and the net effects may be higher than the earlier PLANCK
bounds. In the process, the dark energy, as a cosmological constant decays into
creation of dark matter. The diagnostics for the three-component, spatially
homogeneous tachyonic scalar field are discussed in detail. The components of
the field with perturbed equation of state are taken to interact mutually and
the conservation of energy for individual components gets violated. We study
mainly the $O_{m}(x)$ diagnostics with the observed set of $H(z)$ values at
various redshifts, and the dimensionless state-finders for these interacting
components. This analysis provides a strong case for the interacting dark
energy in our model.


title: Temperature chaos and quenched heterogeneities

abstract:
  We present a treatable generalization of the Sherrington Kirkpatrick model
which introduces correlations in the elements of the coupling matrix through
multiplicative disorder on the single variables and investigate the
consequences on the phase diagram. We define a generalized $q_{EA}$ parameter
and test the structural stability of the SK results in this correlated case
evaluating the AT-line of the model. As main result we demonstrate the increase
of temperature chaos effects due to heterogeneities.


title: Energy transition in vacuum matter coupling

abstract:
  The lately proposed vacuum matter coupling model (arXiv:1303.6568) seems to
be able to provide solutions to a variety of problems in cosmology. This
coupling expressed by a transition term between vacuum energy and matter, but
we point out that an additional energy transition mechanism is necessary for
further development of this model in order to explain observations.


title: Routing of Physarum polycephalum signals using simple chemicals

abstract:
  In previous work the chemotaxis towards simple organic chemicals was
assessed. We utilise the knowledge gained from these chemotactic assays to
route Physarum polycephalum at a series of junctions. By applying chemical
inputs at a simple T-junction we were able to reproducibly control the path
taken by the plasmodium of P. Polycephalum. Where the chemoattractant farnesene
was used at one input a routed signal could be reproducibly generated i.e. P.
Polycephalum moves towards the source of chemoattractant. Where the
chemoattractant was applied at both inputs the signal was reproducibly split.
If a chemorepellent was used then the signal was reproducibly suppressed. If no
chemical input was used in the simple circuit then a random signal was
generated, whereby P. Polycephalum would move towards one output at the
junction, but the direction was randomly selected. We extended this study to a
more complex series of T-junctions to explore further the potential of routing
P. Polycephalum. Although many of the circuits were completed effectively, any
errors from the implementation of the simple T-junction were magnified. There
were also issues with cascading effects through multiple junctions. For example
signal splitting could be reproducibly initiated at the first junction but not
at subsequent junctions. This work highlights the potential for exploiting
chemotaxis to achieve complex and reliable routing of P. Polycephalum signals.
This may be useful in implementing computing algorithms, design of autonomous
robots and directed material synthesis. In additional experiments we showed
that the application of chemoattractant compounds at specific locations on a
homogeneous substrate could be used to reliably control the spatial
configuration of P. Polycephalum. This may have applications in implementing
geometric calculations and in robot navigation tasks such as mapping chemical
plumes.


title: Universality and the QCD Anderson Transition

abstract:
  We study the Anderson-type transition previously found in the spectrum of the
QCD quark Dirac operator in the high temperature, quark-gluon plasma phase.
Using finite size scaling for the unfolded level spacing distribution, we show
that in the thermodynamic limit there is a genuine mobility edge, where the
spectral statistics changes from Poisson to Wigner-Dyson statistics in a
non-analytic way. We determine the correlation length critical exponent, $\nu$,
and find that it is compatible with that of the unitary Anderson model.


title:
Curvatures and hyperbolic flows for natural mechanical systems in
  Finsler geometry

abstract:
  We consider a natural mechanical system on a Finsler manifold and study its
\emph{curvature} using the intrinsic Jacobi equations (called \emph{Jacobi
curves}) along the extremals of the least action of the system. The curvature
for such a system is expressed in terms of the Riemann curvature and the Chern
curvature (involving the gradient of the potential) of the Finsler manifold and
the Hessian of the potential w.r.t. a Riemannian metric induced from the
Finslerian metric. As an application, we give sufficient conditions for the
Hamiltonian flows of the least action to be hyperbolic and show new examples of
Anosov flows.


title:
Study on Delaunay tessellations of 1-irregular cuboids for 3D mixed
  element meshes

abstract:
  Mixed elements meshes based on the modified octree approach contain several
co-spherical point configurations. While generating Delaunay tessellations to
be used together with the finite volume method, it is not necessary to
partition them into tetrahedra; co-spherical elements can be used as final
elements. This paper presents a study of all co-spherical elements that appear
while tessellating a 1-irregular cuboid (cuboid with at most one Steiner point
on its edges) with different aspect ratio. Steiner points can be located at any
position between the edge endpoints. When Steiner points are located at edge
midpoints, 24 co-spherical elements appear while tessellating 1-irregular
cubes. By inserting internal faces and edges to these new elements, this number
is reduced to 13. When 1-irregular cuboids with aspect ratio equal to
$\sqrt{2}$ are tessellated, 10 co-spherical elements are required. If
1-irregular cuboids have aspect ratio between 1 and $\sqrt{2}$, all the
tessellations are adequate for the finite volume method. When Steiner points
are located at any position, the study was done for a specific Steiner point
distribution on a cube. 38 co-spherical elements were required to tessellate
all the generated 1-irregular cubes. Statistics about the impact of each new
element in the tessellations of 1-irregular cuboids are also included. This
study was done by developing an algorithm that construct Delaunay tessellations
by starting from a Delaunay tetrahedral mesh built by Qhull.


title: Re-Examination of Globally Flat Space-Time

abstract:
  In the following, we offer a novel approach to modeling the observed effects
currently attributed to the theoretical concepts of `dark energy', `dark
matter', and `dark flow'. Instead of assuming the existence of these
theoretical concepts, we take an alternative route and choose to redefine what
we consider to be inertial motion as well as what constitutes an inertial frame
of reference in flat space-time. We adopt none of the features of our current
cosmological models except for the requirement that special and general
relativity be local approximations within our revised definition of inertial
systems. Implicit in our ideas is the assumption that at "large enough" scales
one can treat objects within these inertial systems as point-particles having
an insignificant effect on the curvature of space-time. We then proceed under
the assumption that time and space are fundamentally intertwined such that
time- and spatial-translational invariance are not inherent symmetries of flat
space-time (i.e. observable clock rates depend upon both relative velocity and
spatial position within these inertial systems) and take the geodesics of this
theory in the radial Rindler chart as the proper characterization of inertial
motion. With this commitment, we are able to model solely with inertial motion
the observed effects expected to be the result of `dark energy', `dark matter',
and `dark flow'. In addition, we examine the potential observable implications
of our theory in a gravitational system located within a confined region of an
inertial reference frame, subsequently interpreting the Pioneer anomaly as
support for our redefinition of inertial motion. As well, we extend our
analysis into quantum mechanics by quantizing for a real scalar field and find
a possible explanation for the asymmetry between matter and antimatter within
the framework of these redefined inertial systems.


title: Remarks on entanglement entropy for gauge fields

abstract:
  In gauge theories the presence of constraints can obstruct expressing the
global Hilbert space as a tensor product of the Hilbert spaces corresponding to
degrees of freedom localized in complementary regions. In algebraic terms, this
is due to the presence of a center --- a set of operators which commute with
all others --- in the gauge invariant operator algebra corresponding to finite
region. A unique entropy can be assigned to algebras with center, giving place
to a local entropy in lattice gauge theories. However, ambiguities arise on the
correspondence between algebras and regions. In particular, it is always
possible to choose (in many different ways) local algebras with trivial center,
and hence a genuine entanglement entropy, for any region. These choices are in
correspondence with maximal trees of links on the boundary, which can be
interpreted as partial gauge fixings. This interpretation entails a gauge
fixing dependence of the entanglement entropy. In the continuum limit however,
ambiguities in the entropy are given by terms local on the boundary of the
region, in such a way relative entropy and mutual information are finite,
universal, and gauge independent quantities.


title: Rutherford scattering of electron vortices

abstract:
  By considering a cylindrically symmetric generalization of a plane wave, the
first Born approximation of screened Coulomb scattering unfolds two new
dimensions in the scattering problem: transverse momentum and orbital angular
momentum of the incoming beam. In this paper, the elastic Coulomb scattering
amplitude is calculated analytically for incoming Bessel beams. This reveals
novel features occurring for wide angle scattering when the incoming beam is
correctly prepared. The result successfully generalizes the well known
Rutherford formula, incorporating transverse and orbital angular momentum into
the formalism.


title:
An upper bound on the sum of signs of permutations with a condition on
  their prefix sets

abstract:
  The following Proposition is a positive answer to a question about
cancellations between permutations that arises in a model problem in the many
body theory of Fermions. It concerns the mathematically rigorous implementation
of the Pauli exclusion principle.


title:
Nonadditive Entropies Yield Probability Distributions with Biases not
  Warranted by the Data

abstract:
  Different quantities that go by the name of entropy are used in variational
principles to infer probability distributions from limited data. Shore and
Johnson showed that maximizing the Boltzmann- Gibbs form of the entropy ensures
that probability distributions inferred satisfy the multiplication rule of
probability for independent events in the absence of data coupling such events.
Other types of entropies that violate the Shore and Johnson axioms, including
nonadditive entropies such as the Tsallis entropy, violate this basic
consistency requirement. Here we use the axiomatic framework of Shore and
Johnson to show how such nonadditive entropy functions generate biases in
probability distributions that are not warranted by the underlying data.


title: Scalability of the plasma physics code GEM

abstract:
  We discuss a detailed weak scaling analysis of GEM, a 3D MPI-parallelised
gyrofluid code used in theoretical plasma physics at the Max Planck Institute
of Plasma Physics, IPP at Garching b. M\"unchen, Germany. Within a PRACE
Preparatory Access Project various versions of the code have been analysed on
the HPC systems SuperMUC at LRZ and JUQUEEN at J\"ulich Supercomputing Centre
(JSC) to improve the parallel scalability of the application. The diagnostic
tool Scalasca has been used to filter out suboptimal routines. The code uses
the electromagnetic gyrofluid model which is a superset of magnetohydrodynamic
and drift-Alfv\'en microturbulance and also includes several relevant kinetic
processes. GEM can be used with different geometries depending on the targeted
use case, and has been proven to show good scalability when the computational
domain is distributed amongst two dimensions. Such a distribution allows grids
with sufficient size to describe small scale tokamak devices. In order to
enable simulation of very large tokamaks (such as the next generation nuclear
fusion device ITER in Cadarache, France) the third dimension has been
parallelised and weak scaling has been achieved for significantly larger grids.

categories: cs.DC cs.PF physics.comp-ph physics.plasm-ph


title: M3: An Open Model for Measuring Code Artifacts

abstract:
  This document details design considerations of M3: a meta model for source
code artifacts


title:
The uniqueness of physical and chemical natures of graphene: their
  coherence and conflicts

abstract:
  Molecular-crystalline duality of graphene ensures a tight alliance of its
physical and chemical natures, each of which is unique in its own way. The
paper examines the physical-chemical harmony and/or confrontation in terms of
the molecular theory of graphene. Chemistry that is consistent with graphene
physics expectations involves: small mass of carbon atoms, which provides a
lightweight material; sp2 configuration of the atoms valence electrons,
ensuring a flat 2D structure of condensed benzenoid units; high strength of C-C
valence bonds responsible for exclusive mechanical strength. Chemistry that is
in conflict with graphene physics expectations covers: radical character of
graphene material; collective character of electronic system of graphene,
preventing from localization of its response on any external impact; the
molecular nature and topochemical character of graphene mechanics; the
molecular nature of graphene magnetism. Each of the properties is a direct
consequence of the odd electron correlation, on one hand, and ensures a high
instability of graphene material, on the other. Electron correlation inhibition
by deposition of graphene monolayers on substrates is seen as a promising way
to solve the problem.


title: Astronomical Redshifts and the Expansion of Space

abstract:
  In homogeneous cosmological models the wavelength $\lambda$ of a photon
exchanged between two fundamental observers changes in proportion to expansion
of the space $D$ between them, so $\Delta\log(\lambda / D) = 0$. This is
exactly the same as for a pair of observers receding from each other in flat
space-time where the effect is purely kinematic. The interpretation of this has
been the subject of considerable debate, and it has been suggested that all
redshifts are a relative velocity effect, raising the question of whether the
wavelength always stretches in proportion to the emitter-receiver separation.
Here we show that, for low redshift at least, $\Delta\log(\lambda / D)$
vanishes for a photon exchanged between any two freely-falling observers in a
spatially constant tidal field, because such a field stretches wavelengths and
the space between the observers identically. But in general there is a
non-kinematic, and essentially gravitational, component of the redshift that is
given by a weighted average of the gradient of the tidal field along the photon
path. While the redshift can always be formally expressed using the Doppler
formula, in situations where the gravitational redshift dominates, the
`relative velocity' is typically quite different from the rate of change of $D$
and it is misleading to think of the redshift as being a velocity or
`kinematic' effect.


title: Homology under monotone maps between finite topological spaces

abstract:
  It is shown that a surjective monotone map $X\to Y$ between finite
$T_0$-spaces induces a surjective map on homology. As such a map turns out to
be a sequence of edge contractions in the Hasse diagram of $X$, followed by a
homeomorphism, this leads to an explicit relation between the Betti numbers of
$X$ to those of $Y$ and the cokernels of the edge contraction maps on the order
complexes.


title:
Charge asymmetry in high-energy $\mu^+\mu^-$ photoproduction in the
  electric field of a heavy atom

abstract:
  The charge asymmetry in the differential cross section of high-energy
$\mu^+\mu^-$ photoproduction in the electric field of a heavy atom is obtained.
This asymmetry arises due to the Coulomb corrections to the amplitude of the
process (next-to-leading term with respect to the atomic field). The deviation
of the nuclear electric field from the Coulomb field at small distances is
crucially important for the charge asymmetry. Though the Coulomb corrections to
the total cross section are negligibly small, the charge asymmetry is
measurable for selected final states of $\mu^+$ and $\mu^-$. We further discuss
the feasibility for experimental observation of this effect.


title: B_l4 decays and the extraction of |V_ub|

abstract:
  The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| is not well determined
yet. It can be extracted from both inclusive or exclusive decays, like B --> pi
(rho) l nu-bar_l. However, the exclusive determination from B --> rho l
nu-bar_l, in particular, suffers from a large model dependence. In this paper,
we propose to extract |V_ub| from the four-body semileptonic decay B --> pi pi
l nu-bar_l, where the form factors for the pion-pion system are treated in
dispersion theory. This is a model-independent approach that takes into account
the pi-pi rescattering effects, as well as the effect of the rho meson. We
demonstrate that both finite-width effects of the rho meson as well as scalar
pi-pi contributions can be considered completely in this way.


title:
Scanning-gate-induced effects in nonlinear transport through
  nanostructures

abstract:
  We investigate the effect of a scanning gate tip in the nonlinear quantum
transport properties of nanostructures. Generally, we predict that the symmetry
of the current-voltage characteristic in reflection-symmetric samples is broken
by a tip-induced rectifying conductance correction. Moreover, in the case of a
quantum point contact (QPC), the tip-induced rectification term becomes
dominant as compared to the change of the linear conductance at large tip-QPC
distances. Calculations for a weak tip probing a QPC modeled by an abrupt
constriction show that these effects are experimentally observable.


title:
Spectrins in Axonal Cytoskeletons: Dynamics Revealed by Extensions and
  Fluctuations

abstract:
  The macroscopic properties, the properties of individual components and how
those components interact with each other are three important aspects of a
composited structure. An understanding of the interplay between them is
essential in the study of complex systems. Using axonal cytoskeleton as an
example system, here we perform a theoretical study of slender structures that
can be coarse-grained as a simple smooth 3-dimensional curve. We first present
a generic model for such systems based on the fundamental theorem of curves. We
use this generic model to demonstrate the applicability of the well-known
worm-like chain (WLC) model to the network level and investigate the situation
when the system is stretched by strong forces (weakly bending limit). We
specifically studied recent experimental observations that revealed the
hitherto unknown periodic cytoskeleton structure of axons and measured the
longitudinal fluctuations. Instead of focusing on single molecules, we apply
analytical results from the WLC model to both single molecule and network
levels and focus on the relations between extensions and fluctuations. We show
how this approach introduces constraints to possible local dynamics of the
spectrin tetramers in the axonal cytoskeleton and finally suggests simple but
self-consistent dynamics of spectrins in which the spectrins in one spatial
period of axons fluctuate in-sync.


title:
Two-neutron transfer reaction mechanisms in
  $^{12}$C($^6$He,$^{4}$He)$^{14}$C using a realistic three-body $^{6}$He model

abstract:
  The reaction mechanisms of the two-neutron transfer reaction
$^{12}$C($^6$He,$^4$He) have been studied at 30 MeV at the TRIUMF ISAC-II
facility using the SHARC charged-particle detector array. Optical potential
parameters have been extracted from the analysis of the elastic scattering
angular distribution. The new potential has been applied to the study of the
transfer angular distribution to the 2$^+_2$ 8.32 MeV state in $^{14}$C, using
a realistic 3-body $^6$He model and advanced shell model calculations for the
carbon structure, allowing to calculate the relative contributions of the
simultaneous and sequential two-neutron transfer. The reaction model provides a
good description of the 30 MeV data set and shows that the simultaneous process
is the dominant transfer mechanism. Sensitivity tests of optical potential
parameters show that the final results can be considerably affected by the
choice of optical potentials. A reanalysis of data measured previously at 18
MeV however, is not as well described by the same reaction model, suggesting
that one needs to include higher order effects in the reaction mechanism.


title: The return of the bow shock

abstract:
  Recently it has been discussed whether a bow shock ahead of the heliospheric
stagnation region does exist or not. This discussion was triggered by
measurements indicating that the Alfv\'en speed and that of fast magnetosonic
waves are higher than the flow speed of the local interstellar medium (LISM)
relative to the heliosphere and resulted in the conclusion that there might
exist either a bow wave or a slow magnetosonic shock. We demonstrate here that
including the He$^{+}$ component of the LISM yields both an Alfv\'en and fast
magnetosonic wave speed lower than the LISM flow speed. Consequently, the
scenario of a bow shock in front of the heliosphere as modelled in numerous
simulations of the interaction of the solar wind with the LISM remains valid.