title:
Fixed and Unfixed Points: Infrared limits in optimized QCD perturbation
  theory

abstract:
  Perturbative QCD, when optimized by the principle of minimal sensitivity at
fourth order, yields finite results for R(e+e-)(Q) down to Q=0. For two
massless flavours (n_f=2) this occurs because the couplant "freezes" at a fixed
point of the optimized beta function. However, for larger n_f's, between 6.7
and 15.2, the infrared limit arises by a novel mechanism in which the evolution
of the optimized beta function with energy Q is crucial. The evolving beta
function develops a minimum that, as Q -> 0, just touches the axis at a_p (the
"pinch point"), while the infrared limit of the optimized couplant is at a
larger value, a^star (the "unfixed point"). This phenomenon results in R
approaching its infrared limit not as a power law, but as R ->
R^star-const./|ln Q|^2. Implications for the phase structure of QCD as a
function of n_f are briefly considered.


title:
The statistical multifragmentation model for liquid-gas phase transition
  with a compressible nuclear liquid

abstract:
  We propose a new formulation of the statistical multifragmentation model
based on the analysis of the virial expansion for a system of the nuclear
fragments of all sizes. The developed model not only enables us to account for
short-range repulsion, but also to calculate the surface free energy which is
induced by the interaction between the fragments.
  We propose a new parameterization for the liquid phase pressure which allows
us to introduce a compressible nuclear liquid into the statistical
multifragmentation model. The resulting model is exactly solvable and has no
irregular behavior of the isotherms in the mixed phase region that is typical
for mean-field models. The general conditions for the 1-st and 2-nd (or higher)
order phase transitions are formulated. It is shown that all endpoints of the
present model phase diagram are the tricritical points, if the Fisher exponent
$\tau$ is in the range $\{3}{2} \le \tau \le 2$. The treatment of nuclear
liquid compressibility allows us to reduce the tricritical endpoint density of
the statistical multifragmentation model to one third of the normal nuclear
density. A specific attention is paid to of the fragment size distributions in
the region of a negative surface tension at supercritical temperatures.


title: Mean Evolutionary Dynamics for Stochastically Switching Environments

abstract:
  Populations of replicating entities frequently experience sudden or cyclical
changes in environment. We explore the implications of this phenomenon via a
environmental switching parameter in several common evolutionary dynamics
models including the replicator dynamic for linear symmetric and asymmetric
landscapes, the Moran process, and incentive dynamics. We give a simple
relationship between the probability of environmental switching, the relative
fitness gain, and the effect on long term behavior in terms of fixation
probabilities and long term outcomes for deterministic dynamics. We also
discuss cases where the dynamic changes, for instance a population evolving
under a replicator dynamic switching to a best-reply dynamic and vice-versa,
giving Lyapunov stability results.


title:
Characterizing the second smallest eigenvalue of the normalized
  Laplacian of a tree

abstract:
  In this paper we show a monotonicity theorem for the harmonic eigenfunction
of \lambda_{1} of the normalized Laplacian over the points of articulation of a
graph. We introduce the definition of Perron component for the normalized
Laplacian matrix of a graph and show how its second smallest eigenvalue can be
characterized using this definition.


title: Problem of time and Hamiltonian reduction in the (2+2) formalism

abstract:
  We apply the Hamiltonian reduction procedure to general spacetimes of
4-dimensions in the (2+2) formalism and find privileged spacetime coordinates
in which the physical Hamiltonian is expressed in true degrees of freedom only,
namely, the conformal two-metric on the cross section of null hypersurfaces and
its conjugate momentum. The physical time is the area element of the cross
section of null hypersurface, and the physical radial coordinate is defined by
{\it equipotential} surfaces on a given spacelike hypersurface of constant
physical time. The physical Hamiltonian is {\it constraint-free} and manifestly
{\it positive-definite} in the privileged coordinates. We present the complete
set of the Hamilton's equations, and find that they coincide with the
Einstein's equations written in the privileged coordinates. This shows that our
Hamiltonian reduction is self-consistent and respects the general covariance.
This work is a generalization of ADM Hamiltonian reduction of midi-superspace
to 4-dimensional spacetimes with no isometries.


title: A universal framework for entanglement detection

abstract:
  We construct nonlinear multiparty entanglement measures for distinguishable
particles, bosons and fermions. In each case properties of an entanglement
measures are related to the decomposition of the suitably chosen representation
of the relevant symmetry group onto irreducible components. In the case of
distinguishable particles considered entanglement measure reduces to the
well-known many particle concurrence. We prove that our entanglement criterion
is sufficient and necessary for pure states living in both finite and infinite
dimensional spaces. We generalize our entanglement measures to mixed states by
the convex roof extension and give a non trivial lower bound of thus obtained
generalized concurrence.


title: The fractal nature of the Fibonomial triangle

abstract:
  It is well known that Pascal's triangle exhibits fractal behavior when
reduced modulo a prime. We show that the triangle of Fibonomial coefficients
has a similar nature modulo two. Specifically, for any $m \ge 0$, the
subtriangle consisting of the first $3 \cdot 2^m$ rows is duplicated on the
left and right sides of the next $3 \cdot 2^m$ rows, with an inverted triangle
of zeros in between. We give three proofs of this fact. The first uses a
combinatorial interpretation of the Fibonomials due to Sagan and Savage. The
second employs an analogue of Lucas' congruence for the parity of binomial
coefficients. The final one is inductive. We also use induction to show that
the Fibonomial triangle has a similar structure modulo three. We end with some
open questions.


title: Simultaneous Mode and Wavelength Division Multiplexing On-Chip

abstract:
  Significant effort in optical-fiber research has been put in recent years
into realizing mode-division multiplexing (MDM) in conjunction with
wavelength-division multiplexing (WDM) to enable further scaling of the
communication bandwidth per fiber. In contrast almost all integrated photonics
operate exclusively in the single-mode regime. MDM is rarely considered for
integrated photonics due to the difficulty in coupling selectively to
high-order modes which usually results in high inter-modal crosstalk. Here we
show the first demonstration of simultaneous on-chip mode and wavelength
division multiplexing with low modal crosstalk and loss. Our approach can
potentially increase the aggregate data rate by many times for on-chip
ultra-high bandwidth communications.


title: Twisted Interferometry

abstract:
  We propose and analyze the effect of anyonic interferometers that are
designed such that the probe anyons traveling in a given path through the
interferometer twist or braid around each other. These "twisted"
interferometers are found to provide operational utility that may not be
available from anyon braiding operations and standard (untwisted) anyonic
interferometry measurements. In particular, it enables Ising anyons to generate
"magic states," which can be used to implement pi/8-phase gates. We consider
the possible implementations of such twisted interferometers in quantum Hall
systems, 2D p_x + i p_y superconductors, and 2D Majorana heterostructures, and
discuss obstacles and challenges associated with implementation.


title: The Mazur-Ulam theorem

abstract:
  A short proof of the Mazur-Ulam theorem concerning isometries of real normed
spaces.


title:
Survey of cometary CO2, CO, and particulate emissions using the Spitzer
  Space Telescope: Smog check for comets

abstract:
  We surveyed 23 comets using the Infrared Array Camera on the Spitzer Space
Telescope in wide filters centered at 3.6 and 4.5 microns. Emission in the 3.6
micron filter arises from sunlight scattered by dust grains; these images
generally have a coma near the nucleus and a tail in the antisolar direction
due to dust grains swept back by solar radiation pressure. The 4.5 micron
filter contains the same dust grains, as well as strong emission lines from CO2
and CO gas; these show distinct morphologies, in which cases we infer they are
dominated by gas. Based on the ratio of 4.5 to 3.6 micron brightness, we
classify the survey comets as CO2+CO "rich" and "poor." This classification is
correlated with previous classifications by A'Hearn based on carbon-chain
molecule abundance, in the sense that comets classified as "depleted" in
carbon-chain molecules are also "poor" in CO2+CO. The gas emission in the IRAC
4.5 micron images is characterized by a smooth morphology, typically a fan in
the sunward hemisphere with a radial profile that varies approximately as the
inverse of projected distance from the nucleus, as would apply for constant
production and free expansion. There are very significant radial and azimuthal
enhancements in many of the comets, and these are often distinct between the
gas and dust, indicating that ejection of solid material may be driven either
by H2O or CO2. Notable features in the images include the following. There is a
prominent loop of gas emission from 103P/Hartley 2, possible due to an outburst
of CO2 before the Spitzer image. Prominent, double jets are present in the
image of 88P/Howell. A prominent single jet is evident for 3 comets. Spirals
are apparent in 29P and C/2006 W3; we measure a rotation rate of 21 hr for the
latter comet. Arcs (possibly parts of a spiral) are apparent in the images of
10P/Tempel 2, and 2P/Encke.


title: Stochastic solutions of the wave equation

abstract:
  Unlike the heat equation or the Laplace equation, solutions of the wave
equation on general domains have no known stochastic representation. This short
note gives a simple solution to this well known problem in arbitrary
dimensions. The proposed representation has several shortcomings, one of which
is that it does not cover all solutions. Still, it is proof that a large class
of nontrivial solutions of the wave equation in general dimensions and domains
may indeed be represented stochastically.


title: Immersed self-shrinkers

abstract:
  We construct infinitely many complete, immersed self-shrinkers with
rotational symmetry for each of the following topological types: the sphere,
the plane, the cylinder, and the torus.


title: Rare decay B -> K ll form factors from lattice QCD

abstract:
  We calculate, for the first time using unquenched lattice QCD, form factors
for the rare decay B -> Kll in and beyond the Standard Model. Our lattice QCD
calculation utilizes a nonrelativistic QCD formulation for the b valence
quarks, the highly improved staggered quark formulation for the light valence
quarks, and employs the MILC 2+1 asqtad ensembles. The form factor results,
based on the z expansion, are valid over the full kinematic range of q^2. We
construct the ratios f0/f+ and fT/f+, which are useful in constraining new
physics and verifying effective theory form factor symmetry relations. We also
discuss the calculation of Standard Model observables.


title: Linear groups - Malcev's theorem and Selberg's lemma

abstract:
  An account of two fundamental facts concerning finitely generated linear
groups: Malcev's theorem on residual finiteness, and Selberg's lemma on virtual
torsion-freeness.


title: Charged Dilatonic AdS Black Holes and Magnetic AdS_{D-2} x R^2 Vacua

abstract:
  We consider D-dimensional Einstein gravity coupled to two U(1) fields and a
dilaton with a scalar potential. We derive the condition that the analytical
AdS black holes with two independent charges can be constructed. Turning off
the cosmological constant, the extremal Reissner-Nordstrom black hole emerges
as the harmonic superposition of the two U(1) building blocks. With the
non-vanishing cosmological constant, our extremal solutions contain the
near-horizon geometry of AdS_2 x R^{D-2} with or without a hyperscaling. We
also obtain the magnetic AdS_{D-2} x Y^2 vacua where Y^2 can be R^2, S^2 or
hyperbolic 2-space. These vacua arise as the fix points of some super
potentials and recover the known supersymmetric vacua when the theory can be
embedded in gauged supergravities. The AdS_{D-2} x R^2 vacua are of particular
interest since they are dual to some quantum field theories at the lowest
Landau level. By studying the embedding of some of these solutions in the
string and M-theory, we find that the M2/M5-system with the equal M2 and M5
charges can intersect with another such M2/M5 on to a dyonic black hole.
Analogous intersection rule applies also to the D1/D5-system. The intersections
are non-supersymmetric but in the manner of harmonic superpositions.


title: The number of lines in a matroid with no $U_{2,n}$-minor

abstract:
  We show that, if $q$ is a prime power at most 5, then every rank-$r$ matroid
with no $U_{2,q+2}$-minor has no more lines than a rank-$r$ projective geometry
over GF$(q)$. We also give examples showing that for every other prime power
this bound does not hold.


title:
Hardening and termination of long-duration gamma rays detected prior to
  lightning

abstract:
  We report the first observation of 3$-$30 MeV prolonged gamma-ray emission
that was abruptly terminated by lightning. The gamma-ray detection was made
during winter thunderstorms on December 30, 2010 by the Gamma-Ray Observation
of Winter THunderclouds (GROWTH) experiment carried out in a coastal area along
the Sea of Japan. The gamma-ray flux lasted for less than 3 min, continuously
hardening closer to the lightning occurrence. The hardening at energies of
3$-$10 MeV energies was most prominent. The gamma-ray flux abruptly ceased less
than 800 ms before the lightning flash that occurred over 5 km away from the
experimental site. In addition, we observed a clear difference in the duration
of the 3$-$10 MeV gamma rays and those $>$10 MeV, suggesting that the area of
$>$10 MeV gamma-ray emission is considerably smaller than that of the
lower-energy gamma rays. This work may give a manifestation that a local region
emitting prolonged gamma rays connects with a distant region to initiate
lightning.


title: Incentive Processes in Finite Populations

abstract:
  We define the incentive process, a natural generalization of the Moran
process incorporating evolutionary updating mechanisms corresponding to
well-known evolutionary dynamics, such as the logit, projection, and best-reply
dynamics. Fixation probabilities and internal stable states are given for a
variety of incentives, including new closed-forms, as well as results relating
fixation probabilities for members of two one-parameter families of incentive
processes. We show that the behaviors of the incentive process can deviate
significantly from the analogous properties of deterministic evolutionary
dynamics in some ways but are similar in others. For example, while the
fixation probabilities change, their ratio remains constant.


title: On the uniform squeezing property and the squeezing function

abstract:
  We describe the boundary behaviors of the squeezing functions for all bounded
convex domains in $\mathbb{C}^n$ and bounded domains with a $C^2$ strongly
convex boundary point.


title: Simplifying 3-manifolds in R^4

abstract:
  We show that a smooth embedding of a closed 3-manifold in S^3 x R can be
isotoped so that every generic level divides S^3 x t into two handlebodies
(i.e., is Heegaard) provided the original embedding has a unique local maximum
with respect to the R coordinate. This allows uniqueness of embeddings to be
studied via the mapping class group of surfaces and the Schoenflies conjecture
is considered in this light. We also give a necessary and sufficient condition
that a 3-manifold connected summed with arbitrarily many copies of S^1 x S^2
embeds in R^4.


title:
Practical Implementation of High-Order Multiple Precision Fully Implicit
  Runge-Kutta Methods with Step Size Control Using Embedded Formula

abstract:
  We propose a practical implementation of high-order fully implicit
Runge-Kutta(IRK) methods in a multiple precision floating-point environment.
Although implementations based on IRK methods in an IEEE754 double precision
environment have been reported as RADAU5 developed by Hairer and SPARK3
developed by Jay, they support only 3-stage IRK families. More stages and
higher-order IRK formulas must be adopted in order to decrease truncation
errors, which become relatively larger than round-off errors in a multiple
precision environment. We show that SPARK3 type reduction based on the
so-called W-transformation is more effective than the RADAU5 type one for
reduction in computational time of inner iteration of a high-order IRK process,
and that the mixed precision iterative refinement method is very efficient in a
multiple precision floating-point environment. Finally, we show that our
implementation based on high-order IRK methods with embedded formulas can
derive precise numerical solutions of some ordinary differential equations.


title: The first high-resolution observations of 19.9-GHz methanol masers

abstract:
  We have used the Australia Telescope Compact Array to undertake the first
high-resolution observations of the 19.9-GHz methanol maser transition. The
emission is coincident with the location of the targeted 6.7-GHz methanol
masers to within 0.2 arcseconds in absolute position. We find that the relative
distribution of the 19.9-GHz maser emission in our sample differs from that
observed in the 6.7-GHz transition, in contrast to the similar distribution
often seen in the 6.7- and 12.2-GHz methanol masers in many sources. We also
find that the peak velocity for the 19.9-GHz methanol masers is frequently
different from that observed in other class II transitions in the same regions.
These two results suggest that while 19.9-GHz methanol masers arise from the
same general location as other class II transitions, they are likely not
coincident on milliarcsecond scales; which has implications for
multi-transitional modelling of class II methanol maser sources. We have
investigated the properties of the OH and other classII methanol transitions
for those 107-GHz methanol masers with and without an associated 19.9-GHz
methanol maser. On the basis of these comparisons we suggest that the 19.9-GHz
transition traces an evolutionary phase around the peak of the class II maser
luminosity into its decline.


title: Stable commutator length on mapping class groups

abstract:
  Let $\Gamma$ be a finite index subgroup of the mapping class group
$MCG(\Sigma)$ of a closed orientable surface $\Sigma$, possibly with punctures.
We give a precise condition (in terms of the Nielsen-Thurston decomposition)
when an element $g\in\Gamma$ has positive stable commutator length. In
addition, we show that in these situations the stable commutator length, if
nonzero, is uniformly bounded away from 0. The method works for certain
subgroups of infinite index as well and we show $scl$ is uniformly positive on
the nontrivial elements of the Torelli group. The proofs use our earlier
construction in the paper "Constructing group actions on quasi-trees and
applications to mapping class groups" of group actions on quasi-trees.


title:
Pressure-induced softening as a common feature of framework structures
  that have negative thermal expansion

abstract:
  Results of a series of molecular dynamics simulations of cubic siliceous
zeolites suggest that pressure-induced softening -- the phenomenon in which a
material becomes progressively more compressible under pressure -- is likely to
be a common feature of framework materials that show negative thermal
expansion. The correlation between the negative thermal expansion and the
pressure-induced softening is investigated on the basis of thermodynamics.


title: Quandle varieties, generalized symmetric spaces and $\varphi$-spaces

abstract:
  We define a quandle variety as an irreducible algebraic variety $Q$ endowed
with an algebraically defined quandle operation $\rhd$. It can also be seen as
an analogue of a generalized affine symmetric space or a regular $s$-manifold
in algebraic geometry.
  Assume that $Q$ is normal as an algebraic variety and that the action of the
inner automorphism group has a dense orbit. Then we show that there is an
algebraic group $G$ such that each orbit is isomorphic to the quandle $(G/H,
\rhd_\varphi)$ associated to the group $G$, an automorphism $\varphi$ of $G$
and a subgroup $H$ of $G^\varphi$.


title: A sufficient condition on operator order for strictly positive operators

abstract:
  Let $A_{1}$, $A_{2}$, $...$, $A_{k}$ be strictly positive operators on a
Hilbert space. This note is to show a sufficient condition of $A_{k}\geq
A_{k-1}\geq\geq A_{3}\geq A_{2}\geq A_{1}$, which extends the related result
before.


title:
Curvature Couplings in $\mathcal{N}=(2,2)$ Nonlinear Sigma Models on
  $S^2$

abstract:
  Following recent work on GLSM localization, we work out curvature couplings
for rigidly supersymmetric nonlinear sigma models with superpotential for
general target spaces, describing both ordinary and twisted chiral superfields
on round two-sphere worldsheets. We briefly discuss why, unlike
four-dimensional theories, there are no constraints on Kahler forms in these
theories. We also briefly discuss general issues in topological twists of such
theories.


title: Distributed Detection in Coexisting Large-scale Sensor Networks

abstract:
  This paper considers signal detection in coexisting wireless sensor networks
(WSNs). We characterize the aggregate signal and interference from a Poisson
random field of nodes and define a binary hypothesis testing problem to detect
a signal in the presence of interference. For the testing problem, we introduce
the maximum likelihood (ML) detector and simpler alternatives. The proposed
mixed-fractional lower order moment (FLOM) detector is computationally simple
and close to the ML performance, and robust to estimation errors in system
parameters. We also derived asymptotic theoretical performances for the
proposed simple detectors. Monte-Carlo simulations are used to supplement our
analytical results and compare the performance of the receivers.


title:
A modular relation for the chromatic symmetric functions of (3+1)-free
  posets

abstract:
  We consider a linear relation which expresses Stanley's chromatic symmetric
function for a poset in terms of the chromatic symmetric functions of some
closely related posets, which we call the modular law. By applying this in the
context of (3+1)-free posets, we are able to reduce Stanley and Stembridge's
conjecture that the chromatic symmetric functions of all (3+1)-free posets are
e-positive to the case of (3+1)-and-(2+2)-free posets, also known as unit
interval orders. In fact, our reduction can be pushed further to a much smaller
class of posets, for which we have no satisfying characterization. We also
obtain a new proof of the fact that all 3-free posets have e-positive chromatic
symmetric functions.


title: Mining Attribute-based Access Control Policies

abstract:
  Attribute-based access control (ABAC) provides a high level of flexibility
that promotes security and information sharing. ABAC policy mining algorithms
have potential to significantly reduce the cost of migration to ABAC, by
partially automating the development of an ABAC policy from an access control
list (ACL) policy or role-based access control (RBAC) policy with accompanying
attribute data. This paper presents an ABAC policy mining algorithm. To the
best of our knowledge, it is the first ABAC policy mining algorithm. Our
algorithm iterates over tuples in the given user-permission relation, uses
selected tuples as seeds for constructing candidate rules, and attempts to
generalize each candidate rule to cover additional tuples in the
user-permission relation by replacing conjuncts in attribute expressions with
constraints. Our algorithm attempts to improve the policy by merging and
simplifying candidate rules, and then it selects the highest-quality candidate
rules for inclusion in the generated policy.


title:
Satellite probing General Relativity and its extensions and Kolmogorov
  analysis

abstract:
  We apply the Kolmogorov statistic to analyse the residual data of two LAGEOS
satellites on General Relativistic Lense-Thirring effect, and show that it
reveals a tiny difference in the properties of the satellites, possibly related
to Yarkovsky-Rubincam effect. The recently launched LAser RElativity Satellite
(LARES) can provide constraints to the extensions of General Relativity such as
the Chern-Simons (CS) gravity with metric coupled to a scalar field through the
Pontryagin density, so an explicit dependence on the frame dragging
measurements vs the CS parameter is given.


title: On pure quasi quantum quadratic operators of M_2(C)

abstract:
  In the present paper we study quasi quantum quadratic operators (q.q.o)
acting on the algebra of $2\times 2$ matrices $M_2(C)$. It is known that a
channel is called pure if it sends pure states to pure ones. In this papers, we
introduce a weaker condition, called $q$-purity, than purity of the channel. To
study $q$-pure channels, we concentrate ourselves to quasi q.q.o. acting on
$M_2(C)$. We describe all trace-preserving quasi q.q.o. on $M_2(C)$, which
allowed us to prove that if a trace-preserving symmetric quasi q.q.o. such that
the corresponding quadratic operator is linear, then its $q$-purity implies its
positivity. If a symmetric quasi q.q.o. has a Haar state $\tau$, then its
corresponding quadratic operator is nonlinear, and it is proved that such
$q$-pure symmetric quasi q.q.o. cannot be positive. We think that such a result
will allow to check whether a given mapping from $M_2(C)$ to $M_2(C)\o M_2(C)$
is pure or not. On the other hand, our study is related to construction of pure
quantum nonlinear channels. Moreover, it is also considered that nonlinear
dynamics associated with quasi pure q.q.o. may have differen kind of dynamics,
i.e. it may behave chaotically or trivially, respectively.


title: An Aggregation-Based Overall Quality Measurement for Visualization

abstract:
  Aesthetics are often used to evaluate the quality of graph drawings. However,
the existing aesthetic criteria are useful in judging the extents to which a
drawing conforms to particular drawing rules. They have limitations in
evaluating overall quality. Currently the overall quality of graph drawings is
mainly evaluated based on personal judgments and user studies. Personal
judgments are not reliable, while user studies can be costly to run. Therefore,
there is a need for a direct measure of overall quality. This measure can be
used by visualization designers to quickly compare the quality of drawings at
hand at the design stage and make decisions accordingly. In an attempt to meet
this need, we propose a measure that measures overall quality based on
aggregation of individual aesthetic criteria. We present a user study that
validates this measure and demonstrates its capacity in predicting the
performance of human graph comprehension. The implications of the proposed
measure for future research are discussed.


title: Canonical Labelling of Site Graphs

abstract:
  We investigate algorithms for canonical labelling of site graphs, i.e. graphs
in which edges bind vertices on sites with locally unique names. We first show
that the problem of canonical labelling of site graphs reduces to the problem
of canonical labelling of graphs with edge colourings. We then present two
canonical labelling algorithms based on edge enumeration, and a third based on
an extension of Hopcroft's partition refinement algorithm. All run in quadratic
worst case time individually. However, one of the edge enumeration algorithms
runs in sub-quadratic time for graphs with "many" automorphisms, and the
partition refinement algorithm runs in sub-quadratic time for graphs with "few"
bisimulation equivalences. This suite of algorithms was chosen based on the
expectation that graphs fall in one of those two categories. If that is the
case, a combined algorithm runs in sub-quadratic worst case time. Whether this
expectation is reasonable remains an interesting open problem.


title: Energy stability analysis for a hybrid fluid-kinetic plasma model

abstract:
  In plasma physics, a hybrid fluid-kinetic model is composed of a
magnetohydrodynamics (MHD) part that describes a bulk fluid component and a
Vlasov kinetic theory part that describes an energetic plasma component. While
most hybrid models in the plasma literature are non-Hamiltonian, this paper
investigates a recent Hamiltonian variant in its two-dimensional configuration.
The corresponding Hamiltonian structure is described along with its Casimir
invariants. Then, the energy-Casimir method is used to derive explicit
sufficient stability conditions, which imply a stable spectrum and suggest
nonlinear stability.


title: Evolution of the gas kinematics of galaxies in cosmological simulations

abstract:
  We studied the evolution of the gas kinematics of galaxies by performing
hydrodynamical simulations in a cosmological scenario. We paid special
attention to the origin of the scatter of the Tully-Fisher relation and the
features which could be associated with mergers and interactions. We extended
the study by De Rossi et al. (2010) and analysed their whole simulated sample
which includes both, gas disc-dominated and spheroid-dominated systems. We
found that mergers and interactions can affect the rotation curves directly or
indirectly inducing a scatter in the Tully-Fisher Relation larger than the
simulated evolution since z=3. In agreement with previous works, kinematical
indicators which combine the rotation velocity and dispersion velocity in their
definitions lead to a tighter relation. In addition, when we estimated the
rotation velocity at the maximum of the rotation curve, we obtained the best
proxy for the potential well regardless of morphology.


title:
Incompressible States of Dirac Fermions in Graphene with Anisotropic
  Interactions

abstract:
  We report on the properties of incompressible states of Dirac fermions in
graphene in the presence of anisotropic interactions and a quantizing magnetic
field. We introduce the necessary formalism to incorporate the anisotropy in
the system. The incopmpressible state in graphene is found to survive the
anisotropy upto a critical value of the anisotropy parameter. The anisotropy
also introduces two branches in the collective excitations of the corresponding
Laughlin state. It strongly influences the short-range behavior of the
pair-correlation functions in the incompressible ground state.


title:
Information amplification via postselection: A parameter estimation
  perspective

abstract:
  It is known that weak measurement can significantly amplify the mean of
measurement results, sometimes out of the range limited in usual quantum
measurement. This fact, as actively demonstrated recently in both theory and
experiment, implies the possibility to estimate a very small parameter using
the weak measurement technique. But does the weak measurement really bring
about the increase of "information" for parameter estimation? This paper
clarifies that, in a general situation, the answer is NO; more precisely, the
weak measurement cannot further decrease the lower bound of the estimation
error, i.e. the so-called Cram\'{e}r-Rao bound, which is proportional to the
inverse of the quantum Fisher information.


title:
Improved H\"older and reverse H\"{o}lder inequalities for correlated
  Gaussian random vectors

abstract:
  We propose algebraic criteria that yield sharp H\"{o}lder types of
inequalities for the product of functions of Gaussian random vectors with
arbitrary covariance structure. While our lower inequality appears to be new,
we prove that the upper inequality gives an equivalent formulation for the
geometric Brascamp-Lieb inequality for Gaussian measures. As an application, we
retrieve the Gaussian Hypercontractivity as well as its reverse and we present
a generalization of the sharp Young and reverse Young inequalities. From the
latter, we recover several known inequalities in literatures including the
Pr\'{e}kopa-Leindler and Barthe inequalities.


title:
Quadrupole transitions in the bound rotational-vibrational spectrum of
  the hydrogen molecular ion

abstract:
  The three-body Schr\"odinger equation of the H$_2^+$ hydrogen molecular ion
with Coulomb potentials is solved in perimetric coordinates using the
Lagrange-mesh method. The Lagrange-mesh method is an approximate variational
calculation with variational accuracy and the simplicity of a calculation on a
mesh. Energies and wave functions of up to four of the lowest vibrational bound
or quasibound states for total orbital momenta from 0 to 40 are calculated. The
obtained energies have an accuracy varying from about 13 digits for the lowest
vibrational state to at least 9 digits for the third vibrational excited state.
With the corresponding wave functions, a simple calculation using the
associated Gauss quadrature provides accurate quadrupole transition
probabilities per time unit between those states over the whole rotational
bands. Extensive results are presented with six significant figures.


title:
On the distribution of DNA translocation times in solid-state nanopores:
  an analysis using Schrodinger's first-passage-time theory

abstract:
  In this short note, a correction is made to the recently proposed solution
[1] to a 1D biased diffusion model for linear DNA translocation and a new
analysis will be given to the data in [1]. It was pointed out [2] by us
recently that this 1D linear translocation model is equivalent to the one that
was considered by Schrodinger [3] for the Enrenhaft-Millikan measurements [4,5]
on electron charge. Here we apply Schrodinger's first-passage-time distribution
formula to the data set in [1]. It is found that Schrodinger's formula can be
used to describe the time distribution of DNA translocation in solid-state
nanopores. These fittings yield two useful parameters: drift velocity of DNA
translocation and diffusion constant of DNA inside the nanopore. The results
suggest two regimes of DNA translocation: (I) at low voltages, there are clear
deviations from Smoluchowski's linear law of electrophoresis [6] which we
attribute to the entropic barrier effects; (II) at high voltages, the
translocation velocity is a linear function of the applied electric field. In
regime II, the apparent diffusion constant exhibits a quadratic dependence on
applied electric field, suggesting a mechanism of Taylor dispersion effect
likely due the electro-osmotic flow field in the nanopore channel. This
analysis yields a dispersion-free diffusion constant value for the segment of
DNA inside the nanopore which is in agreement with Stokes-Einstein theory
quantitatively. The implication of Schrodinger's formula for DNA sequencing is
discussed.


title:
Proceedings 11th International Workshop on Quantitative Aspects of
  Programming Languages and Systems

abstract:
  Quantitative aspects of computation are important and sometimes essential in
characterising the behavior and determining the properties of systems. They are
related to the use of physical quantities (storage space, time, bandwidth,
etc.) as well as mathematical quantities (e.g. probability and measures for
reliability, security and trust). Such quantities play a central role in
defining both the model of systems (architecture, language design, semantics)
and the methodologies and tools for the analysis and verification of system
properties. The aim of this workshop is to discuss the explicit use of
quantitative information such as time and probabilities either directly in the
model or as a tool for the analysis of systems.


title:
Action Research Can Swing the Balance in Experimental Software
  Engineering

abstract:
  In general, professionals still ignore scientific evidence in place of expert
opinions in most of their decision-making. For this reason, it is still common
to see the adoption of new software technologies in the field without any
scientific basis or well-grounded criteria, but on the opinions of experts.
Experimental Software Engineering is of paramount importance to provide the
foundations to understand the limits and applicability of software
technologies. The need to better observe and understand the practice of
Software Engineering leads us to look for alternative experimental approaches
to support our studies. Different research strategies can be used to explore
different Software Engineering practices. Action Research can be seen as one
alternative to intensify the conducting of important experimental studies with
results of great value while investigating the Software Engineering practices
in depth. In this paper, a discussion on the use of Action Research in Software
Engineering is presented. Aiming at better explaining the application of Action
Research, an experimental study (in vivo) on the investigation of the
subjective decisions of software developers, concerned with the refactoring of
source code to improve source code quality in a distributed software
development context is depicted. In addition, some guidance on how to
accomplish an Action Research study in Software Engineering supplement the
discussions.


title: Positivity for cluster algebras

abstract: We prove the positivity conjecture for all skew-symmetric cluster algebras.


title: Aspects of Gond Astronomy

abstract:
  The Gond community is considered to be one of the most ancient tribes of
India with a continuing history of several thousand years. They are also known
for their largely isolated history which they have retained through the
millennia. Several of their intellectual traditions therefore are a record of
parallel aspects of human intellectual growth, and still preserve their
original flavour and have not been homogenised by the later traditions of
India. In view of this, the Gonds provide a special window to the different
currents that constitute contemporary India. In the present study, we summarise
their mythology, genetics and script. We then investigate their astronomical
traditions and try to understand this community through a survey of 15 Gond
villages spread over Maharashtra, Andhra Pradesh and Madhya Pradesh. We show
that they have a distinctly different view of the sky from the conventional
astronomical ideas encountered elsewhere in India, which is both interesting
and informative. We briefly comment on other aspects of their life as culled
from our encounters with different members of the Gond community.


title: An optical equilibrium in lateral waveguide-resonator optical force

abstract:
  We consider the lateral optical force between resonator and waveguide, and
study the possibility of an equilibrium that occurs solely from the optical
force. We prove analytically that a single- resonance system cannot give such
an equilibrium in resonator-waveguide force. We then show that two-resonance
systems can provide such an equilibrium. We provide an intuitive way to predict
the existence of an equilibrium, and give numerical examples.


title: Atmospheric Circulation of Terrestrial Exoplanets

abstract:
  The investigation of planets around other stars began with the study of gas
giants, but is now extending to the discovery and characterization of
super-Earths and terrestrial planets. Motivated by this observational tide, we
survey the basic dynamical principles governing the atmospheric circulation of
terrestrial exoplanets, and discuss the interaction of their circulation with
the hydrological cycle and global-scale climate feedbacks. Terrestrial
exoplanets occupy a wide range of physical and dynamical conditions, only a
small fraction of which have yet been explored in detail. Our approach is to
lay out the fundamental dynamical principles governing the atmospheric
circulation on terrestrial planets--broadly defined--and show how they can
provide a foundation for understanding the atmospheric behavior of these
worlds. We first survey basic atmospheric dynamics, including the role of
geostrophy, baroclinic instabilities, and jets in the strongly rotating regime
(the "extratropics") and the role of the Hadley circulation, wave adjustment of
the thermal structure, and the tendency toward equatorial superrotation in the
slowly rotating regime (the "tropics"). We then survey key elements of the
hydrological cycle, including the factors that control precipitation, humidity,
and cloudiness. Next, we summarize key mechanisms by which the circulation
affects the global-mean climate, and hence planetary habitability. In
particular, we discuss the runaway greenhouse, transitions to snowball states,
atmospheric collapse, and the links between atmospheric circulation and CO2
weathering rates. We finish by summarizing the key questions and challenges for
this emerging field in the future.


title: A new recentered confidence sphere for the multivariate normal mean

abstract:
  We describe a new recentered confidence sphere for the mean, theta, of a
multivariate normal distribution. This sphere is centred on the positive-part
James-Stein estimator, with radius that is a piecewise cubic Hermite
interpolating polynomial function of the norm of the data vector. This radius
function is determined by numerically minimizing the scaled expected volume, at
theta = 0, of this confidence sphere, subject to the coverage constraint. We
use the computationally-convenient formula, derived by Casella and Hwang [3],
for the coverage probability of a recentered confidence sphere. Casella and
Hwang, op. cit., describe a recentered confidence sphere that is also centred
on the positive-part James-Stein estimator, but with radius function determined
by empirical Bayes considerations. Our new recentered confidence sphere
compares favourably with this confidence sphere, in terms of both the minimum
coverage probability and the scaled expected volume at theta = 0.


title: Timescales on which Star Formation Affects the Neutral ISM

abstract:
  Turbulent neutral hydrogen (HI) line widths are often thought to be driven
primarily by star formation (SF), but the timescale for converting SF energy to
HI kinetic energy is unclear. As a complication, studies on the connection
between Hi line widths and SF in external galaxies often use broadband tracers
for the SF rate, which must implicitly assume that SF histories (SFHs) have
been constant over the timescale of the tracer. In this paper, we compare
measures of HI energy to time-resolved SFHs in a number of nearby dwarf
galaxies. We find that HI energy surface density is strongly correlated only
with SF that occurred 30-40 Myr ago. This timescale corresponds to the
approximate lifetime of the lowest mass supernova progenitors (~ 8 Msun). This
analysis suggests that the coupling between SF and the neutral ISM is strongest
on this timescale, due either to an intrinsic delay between the release of the
peak energy from SF or to the coherent effects of many SNe during this
interval. At \Sigma_SFR > 10^-3 Msun yr^-1 kpc^-2, we find a mean coupling
efficiency between SF energy and HI energy of \epsilon = 0.11 +/- 0.04 using
the 30-40 Myr timescale. However, unphysical efficiencies are required in lower
\Sigma_SFR systems, implying that SF is not the primary driver of HI kinematics
at \Sigma_SFR < 10^-3 Msun yr^-1 kpc^-2.


title: Some basic aspects of analysis on metric and ultrametric spaces

abstract:
  A number of topics involving metrics and measures are discussed, including
some of the special structure associated with ultrametrics.


title:
Relative Observability of Discrete-Event Systems and its Supremal
  Sublanguages

abstract:
  We identify a new observability concept, called relative observability, in
supervisory control of discrete-event systems under partial observation. A
fixed, ambient language is given, relative to which observability is tested.
Relative observability is stronger than observability, but enjoys the important
property that it is preserved under set union; hence there exists the supremal
relatively observable sublanguage of a given language. Relative observability
is weaker than normality, and thus yields, when combined with controllability,
a generally larger controlled behavior; in particular, no constraint is imposed
that only observable controllable events may be disabled. We design algorithms
which compute the supremal relatively observable (and controllable) sublanguage
of a given language, which is generally larger than the normal counterparts. We
demonstrate the new observability concept and algorithms with a Guideway and an
AGV example.


title: Numerical Radii for Tensor Products of Matrices

abstract:
  For $n$-by-$n$ and $m$-by-$m$ complex matrices $A$ and $B$, it is known that
the inequality $w(A\otimes B)\le\|A\|w(B)$ holds, where $w(\cdot)$ and
$\|\cdot\|$ denote, respectively, the numerical radius and the operator norm of
a matrix. In this paper, we consider when this becomes an equality. We show
that (1) if $\|A\|=1$ and $w(A\otimes B)=w(B)$, then either $A$ has a unitary
part or $A$ is completely nonunitary and the numerical range $W(B)$ of $B$ is a
circular disc centered at the origin, (2) if $\|A\|=\|A^k\|=1$ for some $k$,
$1\le k<\infty$, then $w(A)\ge\cos(\pi/(k+2))$, and, moreover, the equality
holds if and only if $A$ is unitarily similar to the direct sum of the
$(k+1)$-by-$(k+1)$ Jordan block $J_{k+1}$ and a matrix $B$ with
$w(B)\le\cos(\pi/(k+2))$, and (3) if $B$ is a nonnegative matrix with its real
part (permutationally) irreducible, then $w(A\otimes B)=\|A\|w(B)$ if and only
if either $p_A=\infty$ or $n_B\le p_A<\infty$ and $B$ is permutationally
similar to a block-shift matrix \[[
  {array}{cccc}
  0 & B_1 & &
  & 0 & \ddots &
  & & \ddots & B_k
  & & & 0
  {array}
  ]\] with $k=n_B$, where $p_A=\sup\{\ell\ge 1: \|A^{\ell}\|=\|A\|^{\ell}\}$
and $n_B=\sup\{\ell\ge 1 : B^{\ell}\neq 0\}$.


title:
Galaxy And Mass Assembly (GAMA): Linking Star Formation Histories and
  Stellar Mass Growth

abstract:
  We present evidence for stochastic star formation histories in low-mass (M* <
10^10 Msun) galaxies from observations within the Galaxy And Mass Assembly
(GAMA) survey. For ~73,000 galaxies between 0.05<z<0.32, we calculate star
formation rates (SFR) and specific star formation rates (SSFR = SFR/M*) from
spectroscopic Halpha measurements and apply dust corrections derived from
Balmer decrements. We find a dependence of SSFR on stellar mass, such that
SSFRs decrease with increasing stellar mass for star-forming galaxies, and for
the full sample, SSFRs decrease as a stronger function of stellar mass. We use
simple parametrizations of exponentially declining star formation histories to
investigate the dependence on stellar mass of the star formation timescale and
the formation redshift. We find that parametrizations previously fit to samples
of z~1 galaxies cannot recover the distributions of SSFRs and stellar masses
observed in the GAMA sample between 0.05<z<0.32. In particular, a large number
of low-mass (M* < 10^10 Msun) galaxies are observed to have much higher SSFRs
than can be explained by these simple models over the redshift range of
0.05<z<0.32, even when invoking mass-dependent staged evolution. For such a
large number of galaxies to maintain low stellar masses, yet harbour such high
SSFRs, requires the late onset of a weak underlying exponentially declining SFH
with stochastic bursts of star formation superimposed.


title:
Ber Performance Analysis of WiMAX PHY Layer under different channel
  conditions

abstract:
  This paper gives an introduction on the IEEE 802.16 standard WIMAX or
Worldwide Interoperability for Microwave Access. The different parts give
details on the architectural specifications of WiMAX networks and also on the
working principle of WiMAX networks including its services provided. It also
provides brief descriptions on its salient features of this technology and how
it benefits the networking industry. A brief outline of the basic building
blocks or equipment of WiMAX architecture is also provided. This paper also
evaluates the simulation performance of IEEE 802.16 OFDM PHY layer. The
Stanford University Interim (SUI) channel model under varying parameters is
selected for the wireless channel in the simulation. The performance
measurements and analysis was done in simulation developed in MATLAB.


title:
Correlations between low energy leptonic CP violation and leptogenesis
  in the light of recent experiments

abstract:
  Leptogenesis is the most favourable mechanism for generating the observed
baryon asymmetry of the Universe (BAU) which implies CP violation in the high
energy scale. The low energy leptonic CP violation is expected to be observed
in the neutrino oscillations and $0\nu 2 \beta$ decay experiments. Generally it
is not possible to connect both the CP violations. Here we revisit the issue of
connecting the two in flavoured leptogenesis scenario within the Type I seesaw
in the light of recent neutrino oscillation and {\it Planck} data. With the
recent precise measurements of $\theta_{13}$ and BAU we are able to find new
correlations between the low and high energy CP violating phases when
leptogenesis occurs at temperature between $10^9$ to $10^{12}$ GeV and there is
no contribution to CP violation from the heavy neutrino sector.


title: Model Selection in Linear Mixed Models

abstract:
  Linear mixed effects models are highly flexible in handling a broad range of
data types and are therefore widely used in applications. A key part in the
analysis of data is model selection, which often aims to choose a parsimonious
model with other desirable properties from a possibly very large set of
candidate statistical models. Over the last 5-10 years the literature on model
selection in linear mixed models has grown extremely rapidly. The problem is
much more complicated than in linear regression because selection on the
covariance structure is not straightforward due to computational issues and
boundary problems arising from positive semidefinite constraints on covariance
matrices. To obtain a better understanding of the available methods, their
properties and the relationships between them, we review a large body of
literature on linear mixed model selection. We arrange, implement, discuss and
compare model selection methods based on four major approaches: information
criteria such as AIC or BIC, shrinkage methods based on penalized loss
functions such as LASSO, the Fence procedure and Bayesian techniques.


title:
Flux-limited solutions for quasi-convex Hamilton-Jacobi equations on
  networks

abstract:
  We study Hamilton-Jacobi equations on networks in the case where Hamiltonians
are quasi-convex with respect to the gradient variable and can be discontinuous
with respect to the space variable at vertices. First, we prove that imposing a
general vertex condition is equivalent to imposing a specific one which only
depends on Hamiltonians and an additional free parameter, the flux limiter.
Second, a general method for proving comparison principles is introduced. This
method consists in constructing a vertex test function to be used in the
doubling variable approach. With such a theory and such a method in hand, we
present various applications, among which a very general existence and
uniqueness result for quasi-convex Hamilton-Jacobi equations on networks.


title:
Estimates on elliptic equations that hold only where the gradient is
  large

abstract:
  We consider a function which is a viscosity solution of a uniformly elliptic
equation only at those points where the gradient is large. We prove that the
H{\"o}lder estimates and the Harnack inequality, as in the theory of Krylov and
Safonov, apply to these functions.


title: Comparison inequalities on Wiener space

abstract:
  We define a covariance-type operator on Wiener space: for F and G two random
variables in the Gross-Sobolev space $D^{1,2}$ of random variables with a
square-integrable Malliavin derivative, we let $Gamma_{F,G}=$ where $D$ is the
Malliavin derivative operator and $L^{-1}$ is the pseudo-inverse of the
generator of the Ornstein-Uhlenbeck semigroup. We use $\Gamma$ to extend the
notion of covariance and canonical metric for vectors and random fields on
Wiener space, and prove corresponding non-Gaussian comparison inequalities on
Wiener space, which extend the Sudakov-Fernique result on comparison of
expected suprema of Gaussian fields, and the Slepian inequality for functionals
of Gaussian vectors. These results are proved using a so-called smart-path
method on Wiener space, and are illustrated via various examples. We also
illustrate the use of the same method by proving a Sherrington-Kirkpatrick
universality result for spin systems in correlated and non-stationary
non-Gaussian random media.


title:
Oscillating dipole model for the X-ray standing wave enhanced
  fluorescence in periodic multilayers

abstract:
  Periodic multilayers give rise to enhanced X-ray fluorescence when a regime
of standing waves occurs within the structure. This regime may concern the
primary radiation used to induce the fluorescence, the secondary radiation of
fluorescence or both of them. Until now, existing models only dealt with
standing wave regime of primary radiation. We present a theoretical approach
based on the oscillating dipole model and the coupled-wave theory that can
treat efficiently any standing wave regime. We compare our simulations to
experimental data available in the literature.


title: Neutrino-nucleus DIS data and their consistency with nuclear PDFs

abstract:
  In this talk, we discuss the compatibility of different deeply inelastic
neutrino-nucleus data sets and the universal nuclear PDFs. This is an issue
that has lately been investigated by different groups but the conclusions have
been surprisingly contradictory. While some studies have found a good overall
agreement between the nuclear PDFs and the neutrino data, others have claimed
for an incompatibility. Here, we demonstrate that the independent neutrino data
sets from NuTeV, CHORUS and CDHSW collaborations differ in the absolute overall
normalization and that it is not possible to accurately reproduce all the data
simultaneously with a single set of PDFs. Our strategy to overcome this
difficulty and allow a consistent use of all neutrino data in global PDF
analyses is to normalize the data by the integrated cross-sections thereby
cancelling possible inaccuracies in the absolute normalization. Indeed, this
brings all data to a surprisingly good mutual agreement underscoring the
x-dependence of the nuclear modifications in a model-independent way. The
consistency of these data with the present nuclear PDFs is verified by
introducing a method to test the effect of a new data set in an existing global
fit that performed a Hessian error analysis.


title: The Discrete-Continuous Logic and its possible quantum realizations

abstract:
  We propose a new version of generalized probabilistic propositional logic,
namely, discrete-continuous logic (DCL) in which every generalized proposition
(GP) is represented as 2x2 nondiagonal positive matrix with unit trace. We
demonstrate that on the set of propositions of this kind one can define both
the discrete logical operations (connectives) such as negation and strong
logical disjunction and in addition one parameter group of continuous
operations (logical rotations). We prove that an arbitrary classical
proposition (which in this logic is represented by the purely diagonal matrix)
can be considered as the result of strong disjunction of two identical GP. This
fact gives one a good reason to presume the DCL as a prime logical substructure
underlying to ordinary propositional logic, which is recorded by our
consciousness. We believe that proposed version of DCL will find many
applications both in physics (quantum logic) and also in cognitive sciences
(mental imagery) for better understanding of the pecular nature of mental brain
operations.


title: Compressive Time Delay Estimation Using Interpolation

abstract:
  Time delay estimation has long been an active area of research. In this work,
we show that compressive sensing with interpolation may be used to achieve good
estimation precision while lowering the sampling frequency. We propose an
Interpolating Band-Excluded Orthogonal Matching Pursuit algorithm that uses one
of two interpolation functions to estimate the time delay parameter. The
numerical results show that interpolation improves estimation precision and
that compressive sensing provides an elegant tradeoff that may lower the
required sampling frequency while still attaining a desired estimation
performance.


title:
Solving single molecules: filtering noisy discrete data made of photons
  and other type of observables

abstract:
  In numerous systems in biophysics and related fields, scientists measure
(with very smart methods) individual molecules (e.g. biopolymers (proteins,
DNA, RNA, etc), nano - crystals, ion channels), aiming at finding a model from
the data. But the noise is not solved accurately in not so few cases and this
may lead to misleading models. Here, we solve the noise. We consider two state
photon trajectories from any on off kinetic scheme (KS): the process emitting
photons with a rate {\gamma}on when it is in the on state, and emitting with a
rate {\gamma}off when it is in the off state. We develop a filter that removes
the noise resulting in clean data also in cases where binning fails. The filter
is a numerical algorithm with various new statistical treatments. It is based
on a new general likelihood function developed here, with observable dependent
form. The filter can solve the noise, in the detectable region of the rate
space: that is, we also find a region where the data is "too" noisy.
Consistency tests will find the region's type from the data. If the data is
ruled "too noisy", binning obviously fails, and one should apply simpler
methods on the raw data and realizing that the extracted information is
partial. We show that not applying the filter while cleaning results in
erroneous rates. This filter (with minor adjustments) can solve the noise in
any discrete state trajectories, yet extensions are needed in "tackling" the
noise from other data, e.g. continuous data and FRET data.
  The filter developed here is complementary with our previous projects in this
field, where we have solved clean two state data with the development of
reduced dimensions forms (RDFs): only the combined procedures enabling building
the most accurate model from noisy trajectories from single molecules


title:
Topological quantum phase transitions in the spin-singlet superconductor
  with Rashba and Dresselhaus (110) spin-orbit couplings

abstract:
  We examine the topological properties of a spin-singlet superconductor with
Rashba and Dresselhaus (110) spin-orbit couplings. We demonstrate that there
are several topological invariants in the Bogoliubov-de Gennes (BdG)
Hamiltonian by symmetry analysis. We use the Pfaffian invariant $\mathcal{P}$
for the particle-hole symmetry to demonstrate all the possible phase diagrams
of the BdG Hamiltonian. We find that the edge spectrum is either Dirac cone or
flat band which supports the emergence of the Majorana fermion in this system.
For the Majorana flat bands, a higher symmetric BdG Hamiltonian is needed to
make them topologically stable. The Pfaffian invariant $\mathcal{P}(k_{y})$ and
the winding number $\mathcal{W}(k_{y})$ are used in determining the location of
the Majorana flat bands.


title: Query Complexity of Correlated Equilibrium

abstract:
  We study lower bounds on the query complexity of determining correlated
equilibrium. In particular, we consider a query model in which an n-player game
is specified via a black box that returns players' utilities at pure action
profiles. In this model we establish that in order to compute a correlated
equilibrium any deterministic algorithm must query the black box an exponential
(in n) number of times.


title:
Enhanced HBVMs for the numerical solution of Hamiltonian problems with
  multiple invariants

abstract:
  Recently, the class of energy-conserving Runge-Kutta methods named
Hamiltonian Boundary Value Methods (HBVMs), has been proposed for the efficient
solution of Hamiltonian problems, as well as for other types of conservative
problems. In this paper, we report further advances concerning such methods,
resulting in their enhanced version (Enhanced HBVMs, or EHBVMs). The basic
theoretical results are sketched, along with a few numerical tests on a
Hamiltonian problem, taken from the literature, possessing multiple invariants.


title:
Efficient implementation of geometric integrators for separable
  Hamiltonian problems

abstract:
  We here investigate the efficient implementation of the energy-conserving
methods named Hamiltonian Boundary Value Methods (HBVMs) recently introduced
for the numerical solution of Hamiltonian problems. In this note, we describe
an iterative procedure, based on a triangular splitting, for solving the
generated discrete problems, when the problem at hand is separable.


title: Strongly clean triangular matrix rings with endomorphisms

abstract:
  A ring $R$ is strongly clean provided that every element in $R$ is the sum of
an idempotent and a unit that commutate. Let $T_n(R,\sigma)$ be the skew
triangular matrix ring over a local ring $R$ where $\sigma$ is an endomorphism
of $R$. We show that $T_2(R,\sigma)$ is strongly clean if and only if for any
$a\in 1+J(R), b\in J(R)$, $l_a-r_{\sigma(b)}: R\to R$ is surjective. Further,
$T_3(R,\sigma)$ is strongly clean if $l_{a}-r_{\sigma(b)},
l_{a}-r_{\sigma^2(b)}$ and $l_{b}-r_{\sigma(a)}$ are surjective for any $a\in
U(R),b\in J(R)$. The necessary condition for $T_3(R,\sigma)$ to be strongly
clean is also obtained.


title: On the dynamics of the interaction between triggered active inclusions

abstract:
  In a one-dimensional elastic medium with finite correlation length and purely
relaxational dynamics, we calculate the time dependence of the elastic force
F(t) exchanged between two active inclusions that trigger an elastic
deformation at t=0. We consider (i) linear inclusions coupling to the field
with a finite force, and (ii) non-linear inclusions imposing a finite
deformation. In the non-linear case, the force exhibits a transient maximum
much larger than the equilibrium force, diverging as ~L^(-2) at separations L
shorter than the field's correlation length. Both the mean-field and the
Casimir component of the interaction are calculated. We also discuss the
typical appearance time and equilibration time of the force, comparing the
linear and the non-linear cases. The existence of a high transient force in the
non-linear case should be a generic feature of elastically-mediated
interactions.


title:
A Preliminary Study of Oxidation of Lignin from Rubber Wood to Vanillin
  in Ionic Liquid Medium

abstract:
  In this study, lignin was oxidised to vanillin by means of oxygen in ionic
liquid (1,3-dimethylimidazolium methylsulphate) medium. The parameters of the
oxidation reaction that have been investigated were the following:
concentration of oxygen (5, 10, 15 and 20 ft3 h-1), reaction time (2, 4, 6, 8
and 10 h) and reaction temperature (25, 40, 60, 80 and 100{\deg}C). The Fourier
transform infrared spectroscopy, high performance liquid chromatography and
ultraviolet-visible analyses were used to characterise the product. The results
revealed vanillin as the product obtained via the oxidation reaction. The
optimum parameters of vanillin production were 20 ft3 h-1 of oxygen for 10 h at
100{\deg}C. In conclusion, 1,3-dimethylimidazolium methylsulphate could be used
as an oxidation reaction medium for the production of vanillin from rubber wood
lignin.


title:
Interfertile oaks in an island environment. II. Limited hybridization
  between Quercus alnifolia Poech and Q. coccifera L. in a mixed stand

abstract:
  Hybridization and introgression between Quercus alnifolia Poech and Q.
coccifera L. is studied by analyzing morphological traits, nuclear and
chloroplast DNA markers. The study site is a mixed stand on Troodos Mountains
(Cyprus) and the analyzed material includes both adult trees and progenies of
specific mother trees. Multivariate analysis of morphological traits shows that
the two species can be well distinguished using simple leaf morphometric
parameters. A lower genetic diversity in Q. alnifolia than in Q. coccifera and
a high interspecific differentiation between the two species are supported by
an analysis of nuclear and chloroplast microsatellites. The intermediacy of the
four designated hybrids is verified by both leaf morphometric and genetic data.
Analysis of progeny arrays provides evidence that interspecific crossings are
rare. This finding is further supported by limited introgression of chloroplast
genomes. Reproductive barriers (e.g. asynchronous phenology, post-zygotic
incompatibilities) might account for this result. A directionality of
interspecific gene flow is indicated by a genetic assignment analysis of
effective pollen clouds with Q. alnifolia acting as pollen donor. Differences
in flowering phenology and species distribution in the stand may have
influenced the direction of gene flow and the genetic differentiation among
effective pollen clouds of different mother trees within species.


title: Spinodal Decomposition in the TiO2-VO2 System

abstract:
  Spinodal decomposition is a ubiquitous phenomenon leading to phase separation
from a uniform solution. We show that a spinodal decomposition occurs in a
unique combination of two rutile compounds of TiO2 and VO2, which are
chemically and physically distinguished from each other: TiO2 is a wide-gap
insulator with photo catalytic activities and VO2 is assumed to be a strongly
correlated electron system which exhibits a dramatic metal-insulator transition
at 342 K. The spinodal decomposition takes place below 830 K at a critical
composition of 34 mol% Ti, generates a unidirectional composition modulation
along the c axis with a wavelength of approximately 6 nm, and finally results
in the formation of self-assembled lamella structures made up of Ti-rich and
V-rich layers stacked alternately with 30-50 nm wavelengths. A metal-insulator
transition is not observed in quenched solid solutions with intermediate
compositions but emerges in the thin V-rich layers as the result of phase
separation. Interestingly, the metal-insulator transition remains as sharp as
in pure VO2 even in such thin layers and takes place at significantly reduced
temperatures of 310-340 K, which is probably due to a large misfit strain
induced by lattice matching at the coherent interface.


title: Anti-glitch of magnetar 1E 2259+586 in the wind braking scenario

abstract:
  The anti-glitch of magnetar 1E 2259+586 is analyzed theoretically. An
enhanced particle wind during the observational interval will taken away
additional rotational energy of the neutron star. This will result in a net
spin-down of the magnetar, i.e., an anti-glitch. In the wind braking scenario
of anti-glitch, there are several predictions: (1) A radiative event will
always accompany the anti-glitch, (2) Decrease/variation of braking index after
anti-glitch, (3) Anti-glitch is just a period of enhanced spin-down. If there
are enough timing observations, a period of enhanced spin-down is expected
instead of an anti-glitch. Applications to previous timing events of SGR
1900+14, and PSR J1846-0258 are also included. It is shown that current timing
events of 1E 2259+586, SGR 1900+14, and PSR J1846-0258 can be understood safely
in the wind braking model. The enhanced spin-down and absence of an anti-glitch
before the giant flare of SGR 1806-20 is consistent with the wind braking
scenario.


title:
Infinite-order diagrammatic summation approach to explicitly correlated
  congruent transformed Hamiltonian

abstract:
  A resolution of identity approach to explicitly correlated congruent
transformed Hamiltonian (CTH) is presented. One of the principle challenges
associated with the congruent transformation of the many-electron Hamiltonian
is the generation of three, four, five, and six particle operators. Successful
application of the congruent transformation requires efficient implementation
of the many-particle operators. In this work, we present the resolution of
identity congruent transformed Hamiltonian (RI-CTH) method to handle
many-particle operators. The resolution of identity was used to project the
explicitly correlated operator in a N-particle finite basis to avoid explicit
computation of the many-particle operators. Single-particle states were
obtained by performing Hartee-Fock calculations, which were then used for
construction of many-particle states. The limitation of the finite nature of
the resolution of identity was addressed by developing partial infinite order
(PIOS) diagrammatic summation technique. In the PIOS method, the matrix
elements of the projected congruent transformed Hamiltonian was expressed in
terms of diagrammatic notation and a subset of diagrams were summed up to
infinite order. The RI-CTH and RI-CTH-PIOS methods were applied to
isoelectronic series of 10-electron systems (Ne,HF,H2O,NH3,CH4) and results
were compared with CISD and CCSD(T) calculations. One of the key results from
this work is that for identical basis set, the RI-CTH-PIOS energies are lower
than CISD and CCSD(T) values.


title: Interplay between Charge and Magnetic Ordering in YbPd

abstract:
  The pressure-temperature phase diagram of an intermediate-valence compound
YbPd was revealed via simultaneous ac-calorimetry and electrical resistivity
measurements. Two successive structural phase transition temperatures, $T_1$ =
125 K and $T_2$ = 110 K, are found to decrease with increasing pressure. The
magnetic ordering transition at $T_{\rm N} ~sim$ 1.9 K decreases monotonically
up to 1.7 GPa and disappears discontinuously at $P_{\rm c} sim$ 1.9 GPa, where
the structural phase transition at $T_2$ is also suppressed. At $P_{\rm c}$,
enhancement of the effective mass and residual resistivity are observed.
Another probable magnetic phase transition, however, is found to take place at
$T_{\rm ML} sim$0.3 K and smoothly varies even when crossing $P_{\rm c}$.
Structural phase transitions at ambient pressure were also studied by a single
crystal X-ray diffraction measurement. Below $T_2$, a tetragonal lattice
distortion with doubling of the unit cell along the c-axis is observed, and
thus there are two inequivalent Yb-sites below $P_{\rm c}$. These results
indicate that one Yb-site, having larger valence configuration and thus smaller
Kondo temperature, orders at $T_{\rm N}$. The other phase transition at $T_{\rm
ML}$ seems to couple to the crystal structure for $T_2 < T < T_1$. YbPd is a
unique system exhibiting magnetic orderings in metallic charge-ordered Yb
systems.


title:
Ballistic Phonon Transport in Ultra-Thin Silicon Layers: Effects of
  Confinement and Orientation

abstract:
  We investigate the effect of confinement and orientation on the phonon
transport properties of ultra-thin silicon layers of thicknesses between 1
nm-16 nm. We employ the modified valence force field method to model the
lattice dynamics and the ballistic Landauer transport formalism to calculate
the thermal conductance. We consider the major thin layer surface orientations
{100}, {110}, {111}, and {112}. For every surface orientation, we study thermal
conductance as a function of the transport direction within the corresponding
surface plane. We find that the ballistic thermal conductance in the thin
layers is anisotropic, with the {110}/<110> channels exhibiting the highest and
the {112}/<111> channels the lowest thermal conductance with a ratio of about
two. We find that in the case of the {110} and {112} surfaces, different
transport orientations can result in ~50% anisotropy in thermal conductance.
The thermal conductance of different transport orientations in the {100} and
{111} layers, on the other hand, is mostly isotropic. These observations are
invariant under different temperatures and layer thicknesses. We show that this
behavior originates from the differences in the phonon group velocities,
whereas the phonon density of states is very similar for all the thin layers
examined. We finally show how the phonon velocities can be understood from the
phonon spectrum of each channel. Our findings could be useful in the design of
the thermal properties of ultra-thin Si layers for thermoelectric and thermal
management applications.


title:
Interfertile oaks in an island environment: I. High nuclear genetic
  differentiation and high degree of chloroplast DNA sharing between Q.
  alnifolia and Q. coccifera in Cyprus. A multipopulation study

abstract:
  The evergreen Quercus alnifolia and Q. coccifera form the only interfertile
pair of oak species growing in Cyprus. Hybridization between the two species
has already been observed and studied morphologically. However, little evidence
exists about the extent of genetic introgression. In the present study, we
aimed to study the effects of introgressive hybridization mutually on both
chloroplast and nuclear genomes. We sampled both pure and mixed populations of
Q. alnifolia and Q. coccifera from several locations across their distribution
area in Cyprus. We analyzed the genetic variation within and between species by
conducting Analysis of Molecular Variance (AMOVA) based on nuclear
microsatellites. Population genetic structure and levels of admixture were
studied by means of a Bayesian analysis (STRUCTURE simulation analysis).
Chloroplast DNA microsatellites were used for a spatial analysis of genetic
barriers. The main part of the nuclear genetic variation was explained by
partition into species groups. High interspecific differentiation and low
admixture of nuclear genomes, both in pure and mixed populations, support
limited genetic introgression between Q. alnifolia and Q. coccifera in Cyprus.
On the contrary, chloroplast DNA haplotypes were shared between the species and
were locally structured suggesting cytoplasmic introgression. Occasional
hybridization events followed by backcrossings with both parental species might
lead to this pattern of genetic differentiation.


title:
Asymptotics of eigenvalues and eigenfunctions of energy-dependent
  Sturm--Liouville equations

abstract:
  We study asymptotics of eigenvalues, eigenfunctions and norming constants of
singular energy-dependent Sturm--Liouville equations with complex-valued
potentials. The analysis essentially exploits the integral representation of
solutions, which we derive using the connection of the problem under study and
a Dirac system of a special form.


title:
Magnetic Systems Triggering the M6.6-class Solar Flare in NOAA Active
  Region 11158

abstract:
  We report a detailed event analysis on the M6.6-class flare in the active
region (AR) NOAA 11158 on 2011 February 13. AR 11158, which consisted of two
major emerging bipoles, showed prominent activities including one X- and
several M-class flares. In order to investigate the magnetic structures related
to the M6.6 event, particularly the formation process of a flare-triggering
magnetic region, we analyzed multiple spacecraft observations and numerical
results of a flare simulation. We observed that, in the center of this
quadrupolar AR, a highly sheared polarity inversion line (PIL) was formed
through proper motions of the major magnetic elements, which built a sheared
coronal arcade lying over the PIL. The observations lend support to the
interpretation that the target flare was triggered by a localized magnetic
region that had an intrusive structure, namely a positive polarity penetrating
into a negative counterpart. The geometrical relationship between the sheared
coronal arcade and the triggering region was consistent with the theoretical
flare model based on the previous numerical study. We found that the formation
of the trigger region was due to a continuous accumulation of the small-scale
magnetic patches. A few hours before the flare occurrence, the series of
emerged/advected patches reconnected with a preexisting fields. Finally, the
abrupt flare eruption of the M6.6 event started around 17:30 UT. Our analysis
suggests that, in a triggering process of a flare activity, all magnetic
systems of multiple scales, not only the entire AR evolution but also the fine
magnetic elements, are altogether involved.


title:
Simulation of forward-reverse stochastic representations for conditional
  diffusions

abstract:
  In this paper we derive stochastic representations for the finite dimensional
distributions of a multidimensional diffusion on a fixed time interval,
conditioned on the terminal state. The conditioning can be with respect to a
fixed point or more generally with respect to some subset. The representations
rely on a reverse process connected with the given (forward) diffusion as
introduced in Milstein, Schoenmakers and Spokoiny [Bernoulli 10 (2004) 281-312]
in the context of a forward-reverse transition density estimator. The
corresponding Monte Carlo estimators have essentially root-$N$ accuracy, and
hence they do not suffer from the curse of dimensionality. We provide a
detailed convergence analysis and give a numerical example involving the
realized variance in a stochastic volatility asset model conditioned on a fixed
terminal value of the asset.


title:
A Fast Fault Tolerant Partitioning Algorithm for Wireless Sensor
  Networks

abstract:
  In this paper, given a random uniform distribution of sensor nodes on a 2-D
plane, a fast self-organized distributed algorithm is proposed to find the
maximum number of partitions of the nodes such that each partition is connected
and covers the area to be monitored. Each connected partition remains active in
a round robin fashion to cover the query region individually. In case of a node
failure, the proposed distributed fault recovery algorithm reconstructs the
affected partition locally utilizing the available free nodes. Simulation
studies show significant improvement in performance compared to the earlier
works in terms of computation time, the diameter of each partition, message
overhead and network lifetime.


title:
Optimal parameter selection for the alternating direction method of
  multipliers (ADMM): quadratic problems

abstract:
  The alternating direction method of multipliers (ADMM) has emerged as a
powerful technique for large-scale structured optimization. Despite many recent
results on the convergence properties of ADMM, a quantitative characterization
of the impact of the algorithm parameters on the convergence times of the
method is still lacking. In this paper we find the optimal algorithm parameters
that minimize the convergence factor of the ADMM iterates in the context of
l2-regularized minimization and constrained quadratic programming. Numerical
examples show that our parameter selection rules significantly outperform
existing alternatives in the literature.


title:
Evidence of a metal-rich surface for the asteroid (16) Psyche from
  interferometric observations in the thermal infrared

abstract:
  We describe the first determination of thermal properties and size of the
M-type asteroid (16) Psyche from interferometric observations obtained with the
Mid-Infrared Interferometric Instrument (MIDI) of the Very Large Telescope
Interferometer. We used a thermophysical model to interpret our interferometric
data. Our analysis shows that Psyche has a low macroscopic surface roughness.
Using a convex 3-D shape model obtained by Kaasalainen et al. (2002, Icarus
159, 369-395), we derived a volume-equivalent diameter for (16) Psyche of 247
+- 25 km or 238 +- 24 km, depending on the possible values of surface
roughness. Our corresponding thermal inertia estimates are 133 or 114
J.m-2.s-0.5.K-1, with a total uncertainty estimated to 40 J.m-2.s-0.5.K-1. They
are among the highest thermal inertia values ever measured for an asteroid of
this size. We consider this as a new evidence of a metal-rich surface for the
asteroid (16) Psyche.


title: Surfaces on Oeljeklaus-Toma Manifolds

abstract:
  Oeljeklaus-Toma manifolds are complex non-K\"ahler manifolds constructed by
Oeljeklaus and Toma from certain number fields. These manifolds generalize
Inoue surfaces of type $S_m$. In this work it is shown that Oeljeklaus-Toma
manifolds could not contain any compact complex submanifolds of dimension 2
(surfaces) except Inoue surfaces.


title:
The Clusters AgeS Experiment (CASE): Variable Stars in the Globular
  Cluster M4

abstract:
  Based on over 3000 BV images of M4 collected in years 1995-2009 we obtain
light curves of 22 variables, 10 of which are newly detected objects. We
identify four detached eclipsing binaries and eight contact binaries. Accurate
periods are found for all but two variables. Nineteen variables are
proper-motion members of the cluster, and the remaining three are field stars.
Five variables are optical counterparts of X-ray sources. For one of the
variables unassociated with X-ray sources we report a flare lasting for about
90 min and reaching an amplitude of 0.11 mag in V. One of the new contact
binaries has a record-low mass ratio q=0.06. Another four such systems show
season-to season luminosity variations probably related to magnetic activity
cycles, whose lengths are surprisingly similar to that of the solar cycle
despite a huge difference in rotational periods. The location of contact
binaries on the color-magnitude diagram of M4 strongly suggests that at least
in globular clusters the principal factor enabling EW systems to form from
close but detached binaries is stellar evolution. We identify 46 blue and
yellow stragglers in M4 and discuss their properties. We also derive a map of
the differential extinction in the central part of M4, and determine the
reddening of a selected reference region, E(B-V)= 0.392 mag.


title:
Ultraviolet and visual flux and line variations of one of the least
  variable Bp stars HD 64740

abstract:
  The light variability of hot magnetic chemically peculiar stars is typically
caused by the flux redistribution in spots with peculiar abundance. This raises
the question why some stars with surface abundance spots show significant
rotational light variability, while others do not. We study the Bp star HD
64740 to investigate how its remarkable inhomogeneities in the surface
distribution of helium and silicon, and the corresponding strong variability of
many spectral lines, can result in one of the faintest photometric
variabilities among the Bp stars. We used model atmospheres and synthetic
spectra calculated for the silicon and helium abundances from surface abundance
maps to predict the ultraviolet and visual light and line variability of HD
64740. The predicted fluxes and line profiles were compared with the observed
ones derived with the IUE, HST, and Hipparcos satellites and with spectra
acquired using the FEROS spectrograph at the 2.2m MPG/ESO telescope. We are
able to reproduce the observed visual light curve of HD 64740 assuming an
inhomogeneous distribution of iron correlated with silicon distribution. The
light variations in the ultraviolet are hardly detectable. We detect the
variability of many ultraviolet lines of carbon, silicon, and aluminium and
discuss the origin of these lines and the nature of their variations. The
maximum abundances of helium and silicon are not high enough to cause
significant light variations. The detected variability of many ultraviolet
lines is most likely of atmospheric origin and reflects the inhomogeneous
elemental surface distribution. The variability of the Civ resonance lines is
stronger and it probably results from the dependence of the wind mass-loss rate
on the chemical composition and magnetic field orientation. We have not been
able to detect a clear signature of the matter trapped in the circumstellar
clouds.


title: Fast Search for Dynamic Multi-Relational Graphs

abstract:
  Acting on time-critical events by processing ever growing social media or
news streams is a major technical challenge. Many of these data sources can be
modeled as multi-relational graphs. Continuous queries or techniques to search
for rare events that typically arise in monitoring applications have been
studied extensively for relational databases. This work is dedicated to answer
the question that emerges naturally: how can we efficiently execute a
continuous query on a dynamic graph? This paper presents an exact subgraph
search algorithm that exploits the temporal characteristics of representative
queries for online news or social media monitoring. The algorithm is based on a
novel data structure called the Subgraph Join Tree (SJ-Tree) that leverages the
structural and semantic characteristics of the underlying multi-relational
graph. The paper concludes with extensive experimentation on several real-world
datasets that demonstrates the validity of this approach.


title: StreamWorks - A system for Dynamic Graph Search

abstract:
  Acting on time-critical events by processing ever growing social media, news
or cyber data streams is a major technical challenge. Many of these data
sources can be modeled as multi-relational graphs. Mining and searching for
subgraph patterns in a continuous setting requires an efficient approach to
incremental graph search. The goal of our work is to enable real-time search
capabilities for graph databases. This demonstration will present a dynamic
graph query system that leverages the structural and semantic characteristics
of the underlying multi-relational graph.


title:
Real-time planar flow velocity measurements using an optical flow
  algorithm implemented on GPU

abstract:
  This paper presents a high speed implementation of an optical flow algorithm
which computes planar velocity fields in an experimental flow. Real-time
computation of the flow velocity field allows the experimentalist to have
instantaneous access to quantitative features of the flow. This can be very
useful in many situations: fast evaluation of the performances and
characteristics of a new setup, design optimization, easier and faster
parametric studies, etc. It can also be a valuable measurement tool for
closed-loop flow control experiments where fast estimation of the state of the
flow is needed. The algorithm is implemented on a Graphics Processing Unit
(GPU). The accuracy of the computation is shown. Computation speed and
scalability are highlighted along with guidelines for further improvements. The
system architecture is flexible, scalable and can be adapted on the fly in
order to process higher resolutions or achieve higher precision. The set-up is
applied on a Backward-Facing Step (BFS) flow in a hydrodynamic channel. For
validation purposes, classical Particle Image Velocimetry (PIV) is used to
compare with instantaneous optical flow measurements. Important flow
characteristics, such as the dynamics of the recirculation bubble, are well
recovered in real time. Accuracy of real-time optical flow measurements is
comparable to off-line PIV computations.


title: Network topology reconstructed from derivative-variable correlations

abstract:
  A method of network reconstruction from the dynamical time series is
introduced, relying on the concept of derivative-variable correlation. Using a
tunable observable as a parameter, the reconstruction of any network with known
interaction functions is formulated via simple matrix equation. We suggest a
procedure aimed at optimizing the reconstruction from the time series of length
comparable to the characteristic dynamical time scale. Our method also provides
a reliable precision estimate. We illustrate the method's implementation via
elementary dynamical models, and demonstrate its robustness to both model and
observation errors.


title: Chaotic Scattering on Individual Quantum Graphs

abstract:
  For chaotic scattering on quantum graphs, the semiclassical approximation is
exact. We use this fact and employ supersymmetry, the colour-flavour
transformation, and the saddle-point approximation to calculate the exact
expression for the lowest and asymptotic expressions in the Ericson regime for
all higher correlation functions of the scattering matrix. Our results agree
with those available from the random-matrix approach to chaotic scattering. We
conjecture that our results hold universally for quantum-chaotic scattering.


title:
Photon Emission from Charged Particles Moving in Undulators Placed in a
  Photonic Crystal

abstract:
  The law of photon radiation from electron beams passing through a photonic
crystal in the presence of an undulator is considered. The spectral-angular
distribution and the time evolution of radiation is found. It is shown that the
characteristics of the radiation intensity in time demonstrate oscillations due
to the interference between undulator and parametric (quasi-Cherenkov)
radiations.


title: Contagious Sets in Expanders

abstract:
  We consider the following activation process in undirected graphs: a vertex
is active either if it belongs to a set of initially activated vertices or if
at some point it has at least $r$ active neighbors, where $r>1$ is the
activation threshold.
  A \emph{contagious set} is a set whose activation results with the entire
graph being active. Given a graph $G$, let $m(G,r)$ be the minimal size of a
contagious set. Computing $m(G,r)$ is NP-hard.
  It is known that for every $d$-regular or nearly $d$-regular graph on $n$
vertices, $m(G,r) \le O(\frac{nr}{d})$. We consider such graphs that
additionally have expansion properties, parameterized by the spectral gap
and/or the girth of the graphs.
  The general flavor of our results is that sufficiently strong expansion
(e.g., $\lambda(G)=O(\sqrt{d})$, or girth $\Omega(\log \log d)$) implies that
$m(G,2) \le O(\frac{n}{d^2})$ (and more generally, $m(G,r) \le
O(\frac{n}{d^{r/(r-1)}})$). Significantly weaker expansion properties suffice
in order to imply that $m(G,2)\le O(\frac{n \log d}{d^2})$. For example, we
show this for graphs of girth at least~7, and for graphs with
$\lambda(G)<(1-\epsilon)d$, provided the graph has no 4-cycles. Nearly
$d$-regular expander graphs can be obtained by considering the binomial random
graph $G(n,p)$ with $p \simeq \frac{d}{n}$ and $d > \log n$. For such graphs we
prove that $\Omega(\frac{n}{d^2 \log d}) \le m(G,2) \le O(\frac{n\log\log
d}{d^2\log d})$ almost surely.
  Our results are algorithmic, entailing simple and efficient algorithms for
selecting contagious sets.


title: A variational algorithm for the detection of line segments

abstract:
  In this paper we propose an algorithm for the detection of edges in images
that is based on topological asymptotic analysis. Motivated from the
Mumford--Shah functional, we consider a variational functional that penalizes
oscillations outside some approximate edge set, which we represent as the union
of a finite number of thin strips, the width of which is an order of magnitude
smaller than their length. In order to find a near optimal placement of these
strips, we compute an asymptotic expansion of the functional with respect to
the strip size. This expansion is then employed for defining a (topological)
gradient descent like minimization method. As opposed to a recently proposed
method by some of the authors, which uses coverings with balls, the usage of
strips includes some directional information into the method, which can be used
for obtaining finer edges and can also result in a reduction of computation
times.


title:
Positive rank gradient and p-largeness for groups defined by
  presentations with p-deficiency less than or equal to one

abstract:
  It is an immediate consequence of the results by Yiftach and Schlage-Puchta
that a presentation with p-deficiency greater than one defines a group with
positive rank gradient. By results of Button and Thillaisundaram, a finite
presentation with p-deficiency greater than one defines a p-large group. Both
Yiftach/Schlage-Puchta and Thillaisundaram extended these results to the
p-deficiency one case. In this paper we consider the case when the presentation
has p-deficiency less than or equal to one.


title: Single-parameter adiabatic charge pumping in carbon nanotube resonators

abstract:
  Single-parameter adiabatic charge pumping, induced by a nearby
radio-frequency antenna, is achieved in suspended carbon nanotubes close to the
mechanical resonance. The charge pumping is due to an important dynamic
adjustment of the oscillating motion to the antenna signal and it is different
from the mechanism active in the two-parameter pumping. Finally, the second
harmonic oscillator response shows an interesting relationship with the first
harmonic that should be experimentally observed.


title: On sequences in 2-normed spaces

abstract:
  A function $f$ defined on a 2-normed space $ (X,||.,.||)$ is ward continuous
if it preserves quasi-Cauchy sequences where a sequence $(x_n)$ of points in
$X$ is called quasi-Cauchy if $lim_{n\rightarrow\infty}||\Delta x_{n},z||=0$
for every $z\in X$. Some other kinds of continuties are also introduced via
quasi-Cauchy sequences in 2-normed spaces. It turns out that uniform limit of
ward continuous functions is again ward continuous.


title: Dynamics of an Inverting Tippe Top

abstract:
  The existing results about inversion of a tippe top (TT) establish stability
of asymptotic solutions and prove inversion by using the LaSalle theorem.
Dynamical behaviour of inverting solutions has only been explored numerically
and with the use of certain perturbation techniques. The aim of this paper is
to provide analytical arguments showing oscillatory behaviour of TT through the
use of the main equation for the TT. The main equation describes time evolution
of the inclination angle $\theta(t)$ within an effective potential
$V(\cos\theta,D(t),\lambda)$ that is deforming during the inversion. We prove
here that $V(\cos\theta,D(t),\lambda)$ has only one minimum which (if Jellett's
integral is above a threshold value
$\lambda>\lambda_{\text{thres}}=\frac{\sqrt{mgR^3I_3\alpha}(1+\alpha)^2}{\sqrt{1+\alpha-\gamma}}$
and $1-\alpha^2<\gamma=\frac{I_1}{I_3}<1$ holds) moves during the inversion
from a neighbourhood of $\theta=0$ to a neighbourhood of $\theta=\pi$. This
allows us to conclude that $\theta(t)$ is an oscillatory function. Estimates
for a maximal value of the oscillation period of $\theta(t)$ are given.


title: Connecting QGP-Heavy Ion Physics to the Early Universe

abstract:
  We discuss properties and evolution of quark-gluon plasma in the early
Universe and compare to laboratory heavy ion experiments. We describe how
matter and antimatter emerged from a primordial soup of quarks and gluons. We
focus our discussion on similarities and differences between the early Universe
and the laboratory experiments.


title:
Comparing first order microscopic and macroscopic crowd models for an
  increasing number of massive agents

abstract:
  In this paper a comparison between first order microscopic and macroscopic
differential models of crowd dynamics is established for an increasing number
$N$ of pedestrians. The novelty is the fact of considering massive agents,
namely particles whose individual mass does not become infinitesimal when $N$
grows. This implies that the total mass of the system is not constant but grows
with $N$. The main result is that the two types of models approach one another
in the limit $N\to\infty$, provided the strength and/or the domain of
pedestrian interactions are properly modulated by $N$ at either scale. This is
consistent with the idea that pedestrians may adapt their interpersonal
attitudes according to the overall level of congestion.


title: The 1+1+2 formalism for Scalar-Tensor gravity

abstract:
  We use the 1+1+2 covariant approach to clarify a number of aspects of
spherically symmetric solutions of non-minimally coupled scalar tensor
theories. Particular attention is focused on the extension of Birkhoff's
theorem and the nature of quasi-local horizons in this context.


title:
Environment-derived constraints on the progenitors of low-luminosity
  type I supernovae

abstract:
  We present a study of the properties of the host galaxies of unusual
transient objects of two types, both being sub-luminous compared with the major
classes of supernovae. Those of one type exhibit unusually strong calcium
features, and have been termed 'Ca-rich'. Those of the second type, with
SN2002cx as the prototype and SN2008ha as the most extreme example to date,
have some properties in common with the first, but show typically lower ejecta
velocities, and different early spectra. We confirm important differences in
the environments of the two types, with the Ca-rich transients preferentially
occurring in galaxies dominated by old stellar populations. Quantitatively, the
association of the the Ca-rich transients with regions of ongoing star
formation is well matched to that of type Ia supernovae. The SN2002cx-like
transients are very different, with none of the present sample occurring in an
early-type host, and a statistical association with star-formation regions
similar to that of type II-P supernovae, and therefore a delay time of 30-50
Myrs.