title: Dynamics between order and chaos in conceptual models of glacial cycles

abstract:
  The dynamics of glacial cycles is studied in terms of the dynamical systems
theory. We explore the dependence of the climate state on the phase of
astronomical forcing by examining five conceptual models of glacial cycles
proposed in the literature. The models can be expressed as quasiperiodically
forced dynamical systems. It is shown that four of them exhibit a strange
nonchaotic attractor (SNA), which is an intermediate regime between
quasiperiodicity and chaos. Then, the dependence of the climate state on the
phase of astronomical forcing is not given by smooth relations, but constitutes
a geometrically strange set. Our result suggests that the dynamics of SNA is a
candidate for the dynamics of glacial cycles, in addition to the well-known
dynamics of quasiperiodicity and chaos.


title:
Quantum Discord, CHSH Inequality and Hidden Variables -- Critical
  reassessment of hidden-variables models

abstract:
  Hidden-variables models are critically reassessed. It is first examined if
the quantum discord is classically described by the hidden-variable model of
Bell in the Hilbert space with $d=2$. The criterion of vanishing quantum
discord is related to the notion of reduction and, surprisingly, the
hidden-variable model in $d=2$, which has been believed to be consistent so
far, is in fact inconsistent and excluded by the analysis of conditional
measurement and reduction. The description of the full contents of quantum
discord by the deterministic hidden-variables models is not possible. We also
re-examine CHSH inequality. It is shown that the well-known prediction of CHSH
inequality $|B|\leq 2$ for the CHSH operator $B$ introduced by Cirel'son is not
unique. This non-uniqueness arises from the failure of linearity condition in
the non-contextual hidden-variables model in $d=4$ used by Bell and CHSH, in
agreement with Gleason's theorem which excludes $d=4$ non-contextual
hidden-variables models. If one imposes the linearity condition, their model is
converted to a factored product of two $d=2$ models which describes quantum
mechanical separable states. The CHSH inequality thus does not test the
hidden-variables model in $d=4$. This observation is consistent with an
application of the CHSH inequality to quantum cryptography by Ekert, which is
based on mixed separable states without referring to dispersion-free
representations. As for hidden-variables models, there exist no viable local
non-contextual models in any dimensions.


title: A density Chinese Remainder Theorem

abstract:
  Given collections A and B of residue classes modulo m and n, respectively, we
investigate conditions on A and B that ensure that, for at least some a in A
and b in B, the linear system x = a mod m, x = b mod n has an integer solution,
and we quantify the number of such admissible pairs (a,b). The special case
where A and B consist of intervals of residue classes has application to the
Lonely Runner Conjecture.


title: Tuning electronic structures via epitaxial strain in Sr2IrO4 thin films

abstract:
  We have synthesized epitaxial Sr2IrO4 thin-films on various substrates and
studied their electronic structures as a function of lattice-strains. Under
tensile (compressive) strains, increased (decreased) Ir-O-Ir bond-angles are
expected to result in increased (decreased) electronic bandwidths. However, we
have observed that the two optical absorption peaks near 0.5 eV and 1.0 eV are
shifted to higher (lower) energies under tensile (compressive) strains,
indicating that the electronic-correlation energy is also affected by in-plane
lattice-strains. The effective tuning of electronic structures under
lattice-modification provides an important insight into the physics driven by
the coexisting strong spin-orbit coupling and electronic correlation.


title: Integrability and Hamiltonian system in isotropic turbulence

abstract:
  We present developments of the Hamiltonian approach to problems of the freely
decay of isotropic turbulence, and also consider specific applications of the
modified Prelle-Singer procedure to isotropic turbulence. It demonstrates that
a nonlinear second order ordinary differential equation is intimately related
to the self-preserving solution of Karman-Howarth equation, admitting
time-dependent first integrals and also proving the nonstandard Hamiltonian
structure, as well as the Liouville sense of integrability.

categories: physics.flu-dyn cond-mat.stat-mech math-ph math.MP nlin.SI


title:
Deriving the static interaction between electric dipoles via the quantum
  gauge transformation

abstract:
  Gauge transformation leaves the electric and the magnetic fields unchanged as
long as the gauge function is treated classically. In this paper we consider
the gauge transformation commonly used to obtain the electric dipole
interaction Hamiltonian in a system of dipoles and the electromagnetic field
(Goeppert-Mayer transformation) and treat the vector potential that appear in
the gauge function as an operator. While it modifies the electric field, the
static interaction between the dipoles is derived.


title: Impact Dynamics of Oxidized Liquid Metal Drops

abstract:
  With exposure to air, many liquid metals spontaneously generate an oxide
layer on their surface. In oscillatory rheological tests, this skin is found to
introduce a yield stress that typically dominates the elastic response but can
be tuned by exposing the metal to hydrochloric acid solutions of different
concentration. We systematically studied the normal impact of eutectic
gallium-indium (eGaIn) drops under different oxidation conditions and show how
this leads to two different dynamical regimes. At low impact velocity (or low
Weber number), eGaIn droplets display strong recoil and rebound from the
impacted surface when the oxide layer is removed. In addition, the degree of
drop deformation or spreading during the impact is controlled by the oxide
skin. We show that the scaling law known from ordinary liquids for the maximum
spreading radius as a function of impact velocity can still be applied to the
case of oxidized eGaIn if an effective Weber number $We^{\star}$ is employed
that uses an effective surface tension factoring in the yield stress. In
contrast, no influence on spreading from different oxidations conditions is
observed for high impact velocity. This suggests that the initial kinetic
energy is mostly damped by bulk viscous dissipation. Results from both regimes
can be collapsed in an impact phase diagram controlled by two variables, the
maximum spreading factor $P_m = R_0/R_m$, given by the ratio of initial to
maximum drop radius, and the impact number $K = We^{\star}/Re^{4/5}$, which
scales with the effective Weber number $We^{\star}$ as well as the Reynolds
number $Re$. The data exhibit a transition from capillary to viscous behavior
at a critical impact number $K_c \sim 0.1$.


title:
Dynamical quorum sensing and clustering dynamics in a population of
  spatially distributed active rotators

abstract:
  A model of clustering dynamics is proposed for a population of spatially
distributed active rotators. A transition from excitable to oscillatory
dynamics is induced by the increase of the local density of active rotators. It
is interpreted as dynamical quorum sensing. In the oscillation regime, phase
waves propagate without decay, which generates an effectively long-range
interaction in the clustering dynamics. The clustering process becomes
facilitated and only one dominant cluster appears rapidly as a result of the
dynamical quorum sensing. An exact localized solution is found to a simplified
model equation, and the competitive dynamics between two localized states is
studied numerically.


title: Regular Circle Actions on 2-connected 7-manifolds

abstract:
  We determine the homeomorphism (resp. diffeomorphism) types of those
2-connected 7-manifolds (resp. smooth 2-connected 7-manifolds) that admit
regular circle actions (resp. smooth regular circle actions).


title: On the Nile Problem by Sir Ronald Fisher

abstract:
  The Nile problem by Ronald Fisher may be interpreted as the problem of making
statistical inference for a special curved exponential family when the minimal
sufficient statistic is incomplete. The problem itself and its versions for
general curved exponential families pose a mathematical-statistical challenge:
studying the subalgebras of ancillary statistics within the $\sigma$-algebra of
the (incomplete) minimal sufficient statistics and closely related questions of
the structure of UMVUEs.
  In this paper a new method is developed that, in particular, proves that in
the classical Nile problem no statistic subject to mild natural conditions is a
UMVUE. The method almost solves an old problem of the existence of UMVUEs. The
method is purely statistical (vs. analytical) and works for any family
possessing an ancillary statistic. It complements an analytical method that
uses only the first order ancillarity (and thus works when the existence of
ancillary subalgebras is an open problem) and works for curved exponential
families with polynomial constraints on the canonical parameters of which the
Nile problem is a special case.


title: The magneto-geostrophic equations: a survey

abstract:
  We discuss recent results obtained by the authors, regarding the analysis of
the magneto-geostrophic equation: a model proposed by Moffat and Loper to study
the geodynamo and turbulence in the Earth's fluid core. We conclude this review
by indicating some open problems around the MG equation, that remain to be
addressed in the future.


title: Risks of Large Portfolios

abstract:
  Estimating and assessing the risk of a large portfolio is an important topic
in financial econometrics and risk management. The risk is often estimated by a
substitution of a good estimator of the volatility matrix. However, the
accuracy of such a risk estimator for large portfolios is largely unknown, and
a simple inequality in the previous literature gives an infeasible upper bound
for the estimation error. In addition, numerical studies illustrate that this
upper bound is very crude. In this paper, we propose factor-based risk
estimators under a large amount of assets, and introduce a high-confidence
level upper bound (H-CLUB) to assess the accuracy of the risk estimation. The
H-CLUB is constructed based on three different estimates of the volatility
matrix: sample covariance, approximate factor model with known factors, and
unknown factors (POET, Fan, Liao and Mincheva, 2013). For the first time in the
literature, we derive the limiting distribution of the estimated risks in high
dimensionality. Our numerical results demonstrate that the proposed upper
bounds significantly outperform the traditional crude bounds, and provide
insightful assessment of the estimation of the portfolio risks. In addition,
our simulated results quantify the relative error in the risk estimation, which
is usually negligible using 3-month daily data. Finally, the proposed methods
are applied to an empirical study.


title:
Potential Importance of Binary Evolution in UV-Optical Spectral Fitting
  of Early-Type Galaxies

abstract:
  Binaries are very common in galaxies, and more than half of Galactic hot
subdwarf stars, which are thought as a possible origin of UV-upturn of old
stellar populations, are found in binaries. Previous works showed that binary
evolution can make the spectra of binary star populations significantly
different from those of single star populations. However, the effect of binary
evolution has not been taken into account in most works of spectral fitting of
galaxies. This paper studies the role of binary evolution in spectral fitting
of early-type galaxies, via a stellar population synthesis model including both
single and binary star populations. Spectra from ultraviolet to optical band
are fitted to determine a few parameters of galaxies. The results show that the
inclusion of binaries in stellar population models may lead to obvious change
in the determination of some galaxy parameters and therefore it is potentially
important for spectral studies. In particular, the ages of young components of
composite stellar populations become much older when using binary star
population models instead of single star population models. This implies that
binary star population models will measure significantly different star
formation histories (SFHs) for galaxies compared to single star population
models. In addition, stellar population models with binary interactions measure
larger dust extinctions than single star population models on average. It
suggests that when using binary star population models instead of single star
population models, negative extinctions are possibly unnecessary in spectral
fitting of early-type galaxies.


title: Collision Rate and Symmetry Factor in Gluon Plasma

abstract:
  The elastic and inelastic collision rates in a gluon gas are calculated. The
symmetry factor and the phase space integral are discussed in detail. With a
symmetry factor and well constrained phase space, the same result can be
obtained as that of the full phase space without the factor. Such an
equivalence is illustrated by analytic and numerical calculations for $gg
\rightarrow gg$ and $gg\rightarrow ggg$ processes.


title: Electron-capture supernovae as origin of 48Ca

abstract:
  We report that electron-capture supernovae (ECSNe), arising from collapsing
oxygen-neon-magnesium cores, are a possible source of 48Ca, whose origin has
remained a long-standing puzzle. Our two-dimensional, self-consistent explosion
model of an ECSN predicts ejection of neutron-rich matter with electron
fractions Ye = 0.40-0.42 and relatively low entropies, s = 13-15 kB per nucleon
(kB is the Boltzmann constant). Post-processing nucleosynthesis calculations
result in appreciable production of 48Ca in such neutron-rich and low-entropy
matter during the quasi-nuclear equilibrium and subsequent freezeout phases.
The amount of ejected 48Ca can account for that in the solar inventory when we
consider possible uncertainties in the entropies or ejecta-mass distribution.
ECSNe could thus be a site of 48Ca production in addition to a hypothetical,
rare class of high-density Type Ia supernovae.


title: The moduli stack of affine stable toric varieties

abstract:
  Let X be an irreducible affine T-variety. We consider families of affine
stable toric T-varieties over X and give a description of the corresponding
moduli space as the quotient stack of an open subscheme in a certain toric
Hilbert scheme under the action of a torus.


title: Pronormality of Hall subgroups in finite simple groups

abstract:
  We prove that Hall subgroups of finite simple groups are pronormal. Thus we
obtain an affirmative answer to Problem 17.45(a) of "Kourovka notebook".


title:
When quantum tomography goes wrong: drift of quantum sources and other
  errors

abstract:
  The principle behind quantum tomography is that a large set of observations
-- many samples from a "quorum" of distinct observables -- can all be explained
satisfactorily as measurements on a single underlying quantum state or process.
Unfortunately, this principle may not hold. When it fails, any standard
tomographic estimate should be viewed skeptically. Here we propose a simple way
to test for this kind of failure using Akaike's Information Criterion (AIC). We
point out that the application of this criterion in a quantum context, while
still powerful, is not as straightforward as it is in classical physics. This
is especially the case when future observables differ from those constituting
the quorum.


title: On the pronormality of Hall subgroups

abstract:
  Fix a set of primes $\pi$. A finite group is said to satisfy $C_\pi$ or, in
other words, to be a $C_\pi$-group, if it possesses exactly one class of
conjugate $\pi$-Hall subgroups. The pronormality of $\pi$-Hall subgroups in
$C_\pi$-groups is proven, or, equivalently, we prove that $C_\pi$ is inherited
by overgroups of $\pi$-Hall subgroups. Thus an affirmative solution to Problem
17.44(a) from the "Kourovka notebook" is obtained. We also provide an example,
showing that Hall subgroups in finite groups are not pronormal in general.


title: Quantum Process Nonclassicality

abstract:
  We propose a definition of nonclassicality for a single-mode quantum-optical
process based on its action on coherent states. If a quantum process transforms
a coherent state to a nonclassical state, it is verified to be nonclassical. To
identify nonclassical processes, we introduce a representation for quantum
processes, called the process-nonclassicality quasiprobability distribution,
whose negativities indicate nonclassicality of the process. Using this
distribution, we derive a relation for predicting nonclassicality of the output
states for a given input state. We experimentally demonstrate our method by
considering the single-photon addition as a nonclassical process, and
predicting nonclassicality of the output state for an input thermal state.


title:
Optimal control problems of fully coupled FBSDEs and viscosity solutions
  of Hamilton-Jacobi-Bellman equations

abstract:
  In this paper we study stochastic optimal control problems of fully coupled
forward-backward stochastic differential equations (FBSDEs). The recursive cost
functionals are defined by controlled fully coupled FBSDEs. We study two cases
of diffusion coefficients $\sigma$ of FSDEs. We use a new method to prove that
the value functions are deterministic, satisfy the dynamic programming
principle (DPP), and are viscosity solutions to the associated generalized
Hamilton-Jacobi-Bellman (HJB) equations. The associated generalized HJB
equations are related with algebraic equations when $\sigma$ depends on the
second component of the solution $(Y, Z)$ of the BSDE and doesn't depend on the
control. For this we adopt Peng's BSDE method, and so in particular, the notion
of stochastic backward semigroup in [16]. We emphasize that the fact that
$\sigma$ also depends on $Z$ makes the stochastic control much more complicate
and has as consequence that the associated HJB equation is combined with an
algebraic equation, which is inspired by Wu and Yu [19]. We use the
continuation method combined with the fixed point theorem to prove that the
algebraic equation has a unique solution, and moreover, we also give the
representation for this solution. On the other hand, we prove some new basic
estimates for fully coupled FBSDEs under the monotonic assumptions. In
particular, we prove under the Lipschitz and linear growth conditions that
fully coupled FBSDEs have a unique solution on the small time interval, if the
Lipschitz constant of $\sigma$\ with respect to $z$ is sufficiently small. We
also establish a generalized comparison theorem for such fully coupled FBSDEs.


title: $L^p$ estimates for fully coupled FBSDEs with jumps

abstract:
  In this paper we study useful estimates, in particular $L^p$-estimates, for
fully coupled forward-backward stochastic differential equations (FBSDEs) with
jumps. These estimates are proved at one hand for fully coupled FBSDEs with
jumps under the monotonicity assumption for arbitrary time intervals and on the
other hand for such equations on small time intervals. Moreover, the
well-posedness of this kind of equation is studied and regularity results are
obtained.


title:
Non-stationary subdivision schemes originated from uniform trigonometric
  B-spline

abstract:
  The paper proposes, an algorithm to produce novel m-point (for any integer
m>=2) binary non-stationary subdivision scheme. It has been developed using
uniform trigonometric B-spline basis functions and smoothness is being analyzed
using the theory of asymptotically equivalence. The results show that the most
of well-known binary approximating schemes can be considered as the
non-stationary counterpart of the proposed algorithm. Furthermore, the schemes
developed by the proposed algorithm has the ability to reproduce or regenerate
the conic sections, trigonometric polynomials and trigonometric splines as
well. Some examples are considered, by choosing an appropriate tension
parameter 0<alpha<pi/3, to show the usefulness.


title: Stochastic differential games for fully coupled FBSDEs with jumps

abstract:
  This paper is concerned with stochastic differential games (SDGs) defined
through fully coupled forward-backward stochastic differential equations
(FBSDEs) which are governed by Brownian motion and Poisson random measure. For
SDGs, the upper and the lower value functions are defined by the controlled
fully coupled FBSDEs with jumps. Using a new transformation introduced in [6],
we prove that the upper and the lower value functions are deterministic. Then,
after establishing the dynamic programming principle for the upper and the
lower value functions of this SDGs, we prove that the upper and the lower value
functions are the viscosity solutions to the associated upper and the lower
Hamilton-Jacobi-Bellman-Isaacs (HJBI) equations, respectively. Furthermore, for
a special case (when $\sigma,\ h$ do not depend on $y,\ z,\ k$), under the
Isaacs' condition, we get the existence of the value of the game.


title: Security and Privacy Issues in Wireless Mesh Networks: A Survey

abstract:
  This book chapter identifies various security threats in wireless mesh
network (WMN). Keeping in mind the critical requirement of security and user
privacy in WMNs, this chapter provides a comprehensive overview of various
possible attacks on different layers of the communication protocol stack for
WMNs and their corresponding defense mechanisms. First, it identifies the
security vulnerabilities in the physical, link, network, transport, application
layers. Furthermore, various possible attacks on the key management protocols,
user authentication and access control protocols, and user privacy preservation
protocols are presented. After enumerating various possible attacks, the
chapter provides a detailed discussion on various existing security mechanisms
and protocols to defend against and wherever possible prevent the possible
attacks. Comparative analyses are also presented on the security schemes with
regards to the cryptographic schemes used, key management strategies deployed,
use of any trusted third party, computation and communication overhead involved
etc. The chapter then presents a brief discussion on various trust management
approaches for WMNs since trust and reputation-based schemes are increasingly
becoming popular for enforcing security in wireless networks. A number of open
problems in security and privacy issues for WMNs are subsequently discussed
before the chapter is finally concluded.


title:
Increasing stability of the inverse boundary value problem for the
  Schr\"odinger equation

abstract:
  In this work we study the phenomenon of increasing stability in the inverse
boundary value problem for the Schr\"odinger equation. This problem was
previously considered by Isakov in which he discussed the phenomenon in
different ranges of the wave number (or energy). The main contribution of this
work is to provide a unified and easier approach to the same problem based on
the complex geometrical optics solutions.


title:
CDM and Baryons as Distinct Fluids in a Linear Approximation for the
  Growth of Structure

abstract:
  A single fluid approximation which treats perturbations in baryons and dark
matter as equal has sometimes been used to calculate the growth of linear
matter density perturbations in the Universe. We demonstrate that properly
accounting for the separate growth of baryon and dark matter fluctuations can
change some predictions of structure formation in the linear domain in a way
that can alter conclusions about the consistency between predictions and
observations for $\Lambda$CDM models versus modified gravity scenarios . Our
results may also be useful for 21cm tomography constraints on alternative
cosmological models for the formation of large scale structure.


title:
Sharp inequalities which generalize the divergence theorem--an extension
  of the notion of quasiconvexity, with an addendum

abstract:
  Subject to suitable boundary conditions being imposed, sharp inequalities are
obtained on integrals over a region $\Omega$ of certain special quadratic
functions $f(\bf{E})$ where $\bf{E}(\bf{x})$ derives from a potential
$\bf{U}(\bf{x})$. With $\bf{E}=\nabla\bf{U}$ it is known that such sharp
inequalities can be obtained when $f(\bf{E})$ is a quasiconvex function and
when $\bf{U}$ satisfies affine boundary conditions (i.e., for some matrix
$\bf{D}$, $\bf{U}=\bf{D}\bf{x}$ on $\partial\Omega$). Here we allow for other
boundary conditions and for fields $\bf{E}$ that involve derivatives of a
variety orders of $\bf{U}$. We define a notion of convexity that generalizes
quasiconvexity. $Q^*$-convex quadratic functions are introduced, characterized
and an algorithm is given for generating sharply $Q^*$-convex functions. We
emphasize that this also solves the outstanding problem of finding an algorithm
for generating extremal quasiconvex quadratic functions. We also treat
integrals over $\Omega$ of special quadratic functions $g(\bf{J})$ where
$\bf{J}(\bf{x})$ satisfies a differential constraint involving derivatives
with, possibly, a variety of orders. The results generalize an example of Kang
and the author in three spatial dimensions where $\bf{J}(\bf{x})$ is a $3\times
3$ matrix valued field satisfying $\nabla\cdot\bf{J}=0$. In the addendum the
paper is clarified. Notably, much more general boundary conditions are given
under which sharp lower bounds on the integrals of certain quadratic functions
of the fields can be obtained. As a consequence, strict $Q^*$-convexity is
found to be an appropriate condition to ensure uniqueness of the solutions of a
wide class of partial differential equations with constant coefficients, in a
given domain $\Omega$ with appropriate boundary conditions.


title:
The mean-field solar dynamo with double cell meridional circulation
  pattern

abstract:
  Recent findings of helioseismology as well as advances in direct numerical
simulations of global dynamics of the Sun have indicated that in each solar
hemisphere the meridional circulation forms the two cells along the in the
convection zone. We investigate properties of a mean-field solar dynamo with
such double-cell meridional circulation. The dynamo model also includes the
realistic profile of solar differential rotation (including the tachocline and
subsurface shear layer), and takes into account effects of turbulent pumping,
anisotropic turbulent diffusivity, and conservation of magnetic helicity.
Contrary to previous flux-transport dynamo models, it is found that the dynamo
model can robustly reproduce the basic properties of the solar magnetic cycles
for a wide range of model parameters and the circulation speed. The best
agreement with observations is achieved when the surface speed of meridional
circulation is about 12 m/s. For this circulation speed the simulated sunspot
activity shows good synchronization with the polar magnetic fields. Such
synchronization was indeed observed during the past sunspot cycles 21 and 22.
We compare theoretical and observed phase diagrams of the sunspot number and
the polar field strength and discuss the peculiar properties of Cycle 23.


title: The geometry of product conjugate connections

abstract:
  Properties of pairs of product conjugate connections are stated with a
special view towards the integrability of the given almost product structure.
We define the analogous in product geometry of the structural and the virtual
tensors from the Hermitian geometry and express the product conjugate
connections in terms of these tensors. Some examples from the geometry of a
pair of complementary distributions are discussed and for this case the above
structural and virtual tensors are expressed in terms of O'Neill-Gray tensor
fields.


title:
Large Current Modulation and Spin-Dependent Tunneling of Vertical
  Graphene/MoS$_{2}$ Heterostructures

abstract:
  Vertical graphene heterostructures have been introduced as an alternative
architecture for electronic devices by using quantum tunneling. Here, we
present that the current on/off ratio of vertical graphene field-effect
transistors is enhanced by using an armchair graphene nanoribbon as an
electrode. Moreover, we report spin-dependent tunneling current of the
graphene/MoS2 heterostructures. When an atomically thin MoS2 layer sandwiched
between graphene electrodes becomes magnetic, Dirac fermions with different
spins feel different height of the tunnel barrier, leading to spin-dependent
tunneling. Our finding will develop the present graphene heterostructures for
electronic devices by improving the device performance and by adding the
possibility of spintronics based on graphene.


title: Morse-Smale systems and horseshoes for three dimensional singular flows

abstract:
  We prove that for every three-dimensional vector field, either it can be
accumulated by Morse-Smale ones, or it can be accumulated by ones with a
transverse homoclinic intersection of some hyperbolic periodic orbit in the
$C^1$ topology.


title:
A five dimensional model with a fifth dimension as fundamental as time
  in terms of a cosmological approach

abstract:
  In five dimensional cosmological models, the convention is to include the
fifth dimension in a way similar to the other space dimensions. In this work we
attempt to introduce the fifth dimension in a way that a time dimension would
be introduced. With such an internal space, we are able to obtain accelerated
expansion without introducing dark energy. We obtain a five dimensional flat,
meaning both Ricci flat and conformally flat, spacetime into which all relevant
four dimensional cosmologies can be locally embedded. We also argue on the
choice of the cosmological frame. The choice that is simplest and most
convenient in terms of dimensional analysis, amounts to a linearly expanding
universe.


title: Non-monetary fair scheduling---a cooperative game theory approach

abstract:
  We consider a multi-organizational system in which each organization
contributes processors to the global pool but also jobs to be processed on the
common resources. The fairness of the scheduling algorithm is essential for the
stability and even for the existence of such systems (as organizations may
refuse to join an unfair system).
  We consider on-line, non-clairvoyant scheduling of sequential jobs. The
started jobs cannot be stopped, canceled, preempted, or moved to other
processors. We consider identical processors, but most of our results can be
extended to related or unrelated processors.
  We model the fair scheduling problem as a cooperative game and we use the
Shapley value to determine the ideal fair schedule. In contrast to the current
literature, we do not use money to assess the relative utilities of jobs.
Instead, to calculate the contribution of an organization, we determine how the
presence of this organization influences the performance of other
organizations. Our approach can be used with arbitrary utility function (e.g.,
flow time, tardiness, resource utilization), but we argue that the utility
function should be strategy resilient. The organizations should be discouraged
from splitting, merging or delaying their jobs. We present the unique (to
within a multiplicative and additive constants) strategy resilient utility
function.
  We show that the problem of fair scheduling is NP-hard and hard to
approximate. However, for unit-size jobs, we present an FPRAS. Also, we show
that the problem parametrized with the number of organizations is FPT. Although
for the large number of the organizations the problem is computationally hard,
the presented exponential algorithm can be used as a fairness benchmark.


title: Singular measure as principal eigenfunction of some nonlocal operators

abstract:
  In this paper, we are interested in the spectral properties of the
generalised principal eigenvalue of some nonlocal operator. That is, we look
for the existence of some particular solution $(\lambda,\phi)$ of a nonlocal
operator. $$\int_{\O}K(x,y)\phi(y)\, dy +a(x)\phi(x) =-\lambda \phi(x),$$ where
$\O\subset\R^n$ is an open bounded connected set, $K$ a nonnegative kernel and
$a$ is continuous. We prove that for the generalised principal eigenvalue
$\lambda_p:=\sup \{\lambda \in \R \, |\, \exists \, \phi \in C(\O), \phi > 0
\;\text{so that}\; \oplb{\phi}{\O}+ a(x)\phi + \lambda\phi\le 0\}$ there exists
always a solution $(\mu, \lambda_p)$ of the problem in the space of signed
measure. Moreover $\mu$ a positive measure. When $\mu$ is absolutely continuous
with respect to the Lebesgue measure, $\mu =\phi_p(x)$ is called the principal
eigenfunction associated to $\lambda_p$. In some simple cases, we exhibit some
explicit singular measures that are solutions of the spectral problem.


title: Broken $S_3$ Neutrinos

abstract:
  Motivated by recent measurements which strongly support a nonzero reactor
mixing angle $\theta_{13}$, we study a deviation from $S_3$ neutrino discrete
symmetry by explicitly breaking the neutrino mass matrix with a general
retrocirculant matrix. We show that nonzero $\theta_{13}$ and nonzero CP
violation parameter $J_{CP}$ arise due to the difference between $y_2$ and
$y_3$. We demonstrate that it is possible to obtain the experimentally favored
results for neutrino masses and mixing angles from this mass matrix.
Furthermore, we estimate the effective masses $m_{\beta}$ and $m_{\beta \beta}$
and total neutrino mass $\sum |m_i|$ predicted by this mass matrix.


title:
Channel Coding and Lossy Source Coding Using a Constrained Random Number
  Generator

abstract:
  Stochastic encoders for channel coding and lossy source coding are introduced
with a rate close to the fundamental limits, where the only restriction is that
the channel input alphabet and the reproduction alphabet of the lossy source
code are finite. Random numbers, which satisfy a condition specified by a
function and its value, are used to construct stochastic encoders. The proof of
the theorems is based on the hash property of an ensemble of functions, where
the results are extended to general channels/sources and alternative formulas
are introduced for channel capacity and the rate-distortion region. Since an
ensemble of sparse matrices has a hash property, we can construct a code by
using sparse matrices, where the sum-product algorithm can be used for encoding
and decoding by assuming that channels/sources are memoryless.


title: A Family of Five-Weight Cyclic Codes and Their Weight Enumerators

abstract:
  Cyclic codes are a subclass of linear codes and have applications in consumer
electronics, data storage systems, and communication systems as they have
efficient encoding and decoding algorithms. In this paper, a family of $p$-ary
cyclic codes whose duals have three zeros are proposed. The weight distribution
of this family of cyclic codes is determined. It turns out that the proposed
cyclic codes have five nonzero weights.


title: A Boltzmann treatment for the vorton excess problem

abstract:
  We derive and solve a Boltzmann equation governing the cosmological evolution
of the number density of current carrying cosmic string loops, whose
centrifugally supported equilibrium configurations are also referred to as
vortons. The phase space is three-dimensional and consists of the time
variable, the loop size, and a conserved quantum number. Our approach includes
gravitational wave emission, a possibly finite lifetime for the vortons and
works with any initial loop distribution and for any loop production function.
We then show how our results generalize previous approaches on the vorton
excess problem by tracking down the time evolution of the various
sub-populations of current-carrying loops in a string network.


title:
A Frostman type lemma for sets with large intersections, and an
  application to Diophantine approximation

abstract:
  We consider classes $\mathscr{G}^s ([0,1])$ of subsets of $[0,1]$, originally
introduced by Falconer, that are closed under countable intersections, and such
that every set in the class has Hausdorff dimension at least $s$. We provide a
Frostman type lemma to determine if a limsup-set is in such a class. Suppose $E
= \limsup E_n \subset [0,1]$, and that $\mu_n$ are probability measures with
support in $E_n$. If there is a constant $C$ such that \[\iint|x-y|^{-s}\,
\mathrm{d}\mu_n(x)\mathrm{d}\mu_n(y)<C\] for all $n$, then under suitable
conditions on the limit measure of the sequence $(\mu_n)$, we prove that the
set $E$ is in the class $\mathscr{G}^s ([0,1])$. As an application we prove
that for $\alpha > 1$ and almost all $\lambda \in (\frac{1}{2},1)$ the set \[
E_\lambda(\alpha) = \{\,x\in[0,1] : |x - s_n| < 2^{-\alpha n} \text{infinitely
often}\ \}\] where $s_n \in \{\,(1-\lambda)\sum_{k=0}^na_k\lambda^k$ and
$a_k\in\{0,1\}\,\}$, belongs to the class $\mathscr{G}^s$ for $s \leq
\frac{1}{\alpha}$. This improves one of our previous results.


title: "Warm" Tachyon Matter from Back-reaction on the Brane

abstract:
  We study a 3-brane moving in the five-dimensional bulk of the Randall-Sundrum
II model. By including back-reaction of the brane on the bulk geometry we
obtain a tachyon model with a linear barotropic equation of state.


title: Positive stable densities and the bell-shape

abstract:
  We show that positive stable densities are bell-shaped, that is their n-th
derivatives vanish exactly n times on (0,+oo) and have an alternating sign
sequence. This confirms the graphic predictions of Holt and Crow (1973) in the
positive case.


title: Cooperative spontaneous emission of three identical atoms

abstract:
  We study the influence of the distribution of atoms on the cooperative
spontaneous emission by a simple model of three identical atoms. The effects of
counter rotating terms are included by a unitary transformation method. By
discussing two special cases that the three atoms are arranged as an
equilateral triangle and in a straight line, we find that the superradiance of
the coherent system largely dependent on the homogeneity of the atoms'
distribution. If the atoms distribute symmetrically, the superradiant emission
will be enhanced. Next, we calculate the emission spectra of three identical
atoms under the single-photon state. We find that the distribution of atoms
also has a great impact on the lamb shift and the spectrum. If three atoms are
placed into an equilateral triangle and the same dipole moment is perpendicular
to the plane of the three atoms, the spectrum will degenerate into two peaks
from the three peaks for general case.


title:
Systematic investigation of E1 strength for the isotopes from Z = 28 to
  50

abstract:
  We carry out a systematic study of electric dipole mode (E1) for neutron-rich
isotopes from nickel (Z=28) to tin (Z=50) using a time-dependent mean-field
theory. Our time-dependent scheme is the canonical-basis time-dependent
Hartree-Fock-Bogoliubov theory which can self-consistently describe nuclear
dynamics with pairing correlation. We focus our discussion on the pygmy dipole
resonance (PDR) and E1 polarizability. The correlation between neutron-skin
thickness and PDR strongly depends on the neutron number, but the correlation
between the skin thickness and E1 polarizability is much more stable.


title:
Shell evolution of N=20 nuclei and Gamow-Teller strengths of
  $^{30,32,34}$Mg by the deformed QRPA

abstract:
  Gamow-Teller (GT) strength distributions of Mg isotopes are investigated
within a framework of the deformed quasi-particle random phase
approximation(DQRPA). We found that the N=20 shell closure in $^{28 \sim 34}$Mg
was broken by the prolate shape deformation originating from the {\it
fp}-intruder states. The shell closure breaking gives rise to a shift of
low-lying GT excited states into high-lying states. Discussions regarding the
shell evolution trend of single particle states around N=20 nuclei are also
presented with the comparison to other approaches.


title:
Azimuthal correlation among jets produced in association with a bottom
  or top quark pair at the LHC

abstract:
  Angular correlation of jets produced in association with a massive scalar,
vector or tensor boson is crucial in the determination of their spin and CP
properties. We study jet angular correlations in events with a high mass bottom
quark pair or a top quark pair and two jets at the LHC, whose cross-section is
dominated by the virtual gluon fusion sub-processes when appropriate kinematic
selection cuts (vector-boson fusion cuts) are applied. We evaluate helicity
amplitudes for sub-processes initiated by qq, qg and gg collisions in the limit
where the intermediate gluons are collinear to the initial partons. We first
obtain a general expression for the azimuthal angle correlations among the
dijets and t t-bar or b b-bar, in terms of the gg to t t-bar or b b-bar
helicity amplitudes in the real gluon approximation of the full matrix
elements, and find simple analytic expressions in the two kinematic limits, the
production of a heavy quark pair near the threshold, and in the relativistic
limit where the invariant mass of the heavy quark pair is much larger than the
quark mass. For b b-bar + 2 jets we find strong azimuthal angle correlations
which are distinct from those expected for events with a CP-even or odd scalar
boson which may decay into a b b-bar pair. For t t-bar + 2 jets we find that
the angular correlations are similar to that of a CP-odd scalar+2 jets near the
threshold M_(t t-bar) ~ 2 m_t, while in the relativistic limit they resemble
the distribution for b b-bar + 2 jets. These correlations in the standard QCD
processes will help establish the experimental technique to measure the spin
and CP properties of new particles produced via gluon fusion at the LHC.


title: The ballistic method of pumping solid-state lasers

abstract:
  The ballistic method for obtaining a dense radiating plasma and the
possibilities of using this method to pump solid-state lasers are investigated.
The plasma was obtained experimentally by heating the working gas in a
ballistic plasmatron. A vortex chamber is proposed for transferring energy into
the plasmatron - laser system.


title:
Improved Accuracy of PSO and DE using Normalization: an Application to
  Stock Price Prediction

abstract:
  Data Mining is being actively applied to stock market since 1980s. It has
been used to predict stock prices, stock indexes, for portfolio management,
trend detection and for developing recommender systems. The various algorithms
which have been used for the same include ANN, SVM, ARIMA, GARCH etc. Different
hybrid models have been developed by combining these algorithms with other
algorithms like roughest, fuzzy logic, GA, PSO, DE, ACO etc. to improve the
efficiency. This paper proposes DE-SVM model (Differential EvolutionSupport
vector Machine) for stock price prediction. DE has been used to select best
free parameters combination for SVM to improve results. The paper also compares
the results of prediction with the outputs of SVM alone and PSO-SVM model
(Particle Swarm Optimization). The effect of normalization of data on the
accuracy of prediction has also been studied.


title: RandomBoost: Simplified Multi-class Boosting through Randomization

abstract:
  We propose a novel boosting approach to multi-class classification problems,
in which multiple classes are distinguished by a set of random projection
matrices in essence. The approach uses random projections to alleviate the
proliferation of binary classifiers typically required to perform multi-class
classification. The result is a multi-class classifier with a single
vector-valued parameter, irrespective of the number of classes involved. Two
variants of this approach are proposed. The first method randomly projects the
original data into new spaces, while the second method randomly projects the
outputs of learned weak classifiers. These methods are not only conceptually
simple but also effective and easy to implement. A series of experiments on
synthetic, machine learning and visual recognition data sets demonstrate that
our proposed methods compare favorably to existing multi-class boosting
algorithms in terms of both the convergence rate and classification accuracy.


title: Graphene nanoflakes - structural and electronic properties

abstract:
  The structures, cohesive energies and HOMO-LUMO gaps of graphene nanoflakes
and corresponding polycyclic aromatic hydrocarbons for a large variety of size
and topology are investigated at the density functional based tight-binding
level. Polyacene-like and honeycomb-like graphene nanoflakes were chosen as the
topological limit structures. The influence of unsaturated edge atoms and
dangling bonds on the stability is discussed. Our survey shows a linear trend
for the cohesive energy as function of Ns/N (N - total number of atoms and Ns
is number of edge atoms). For the HOMO-LUMO gap the trends are more complex and
include also the topology of the edges.


title: Adaptive Energy Aware Data Aggregation Tree for Wireless Sensor Networks

abstract:
  To meet the demands of wireless sensor networks (WSNs) where data are usually
aggregated at a single source prior to transmitting to any distant user, there
is a need to establish a tree structure inside to aggregate data. In this
paper, an adaptive energy aware data aggregation tree (AEDT) is proposed. The
proposed tree uses the maximum energy available node as the data aggregator
node. The tree incorporates sleep and awake technology where the communicating
node and the parent node are only in awake state rest all the nodes go to sleep
state saving the network energy and enhancing the network lifetime. When the
traffic load crosses the threshold value, then the packets are accepted
adaptively according to the communication capacity of the parent node. The
proposed tree maintains a memory table which stores the value of each selected
path. Path selection is based on shortest path algorithm where the node with
highest available energy is always selected as forwarding node. By simulation
results, we show that our proposed tree enhances network lifetime minimizes
energy consumption and achieves good delivery ratio with reduced delay.


title:
Nonlinear Correction to the Euler Buckling Formula for Compressed
  Cylinders with Guided-Guided End Conditions

abstract:
  Euler's celebrated buckling formula gives the critical load $N$ for the
buckling of a slender cylindrical column with radius $B$ and length $L$ as \[ N
/ (\pi^3 B^2) = (E/4)(B/L)^2, \] where $E$ is Young's modulus. Its derivation
relies on the assumptions that linear elasticity applies to this problem, and
that the slenderness $(B/L)$ is an infinitesimal quantity. Here we ask the
following question: What is the first nonlinear correction in the right
hand-side of this equation when terms up to $(B/L)^4$ are kept? To answer this
question, we specialize the exact solution of incremental non-linear elasticity
for the homogeneous compression of a thick compressible cylinder with
lubricated ends to the theory of third-order elasticity. In particular, we
highlight the way second- and third-order constants ---including Poisson's
ratio--- all appear in the coefficient of $(B/L)^4$.


title:
ZnO UV photodetector with controllable quality factor and
  photosensitivity

abstract:
  ZnO nanowires have an enormous potential for applications as ultra-violet
(UV) photodetectors. Their mechanism of photocurrent generation is intimately
related with the presence of surface states where considerable efforts, such as
surface chemical modifications, have been pursued to improve their
photodetection capabilities. In this work, we report a step further in this
direction demonstrating that the photosensitivity and quality factor (Q factor)
of the photodetector are entirely tunable by an applied gate voltage. This
mechanism enables UV photodetection selectivity ranging from wavelengths from
tens of nanometers (full width at half maximum - FWHM) down to a narrow
detection of 3 nm. Such control paves the way for novel applications,
especially related to the detection of elements that have very sharp
luminescence.


title: Local conditioning in Dawson-Watanabe superprocesses

abstract:
  Consider a locally finite Dawson-Watanabe superprocess $\xi=(\xi_t)$ in
$\mathsf{R}^d$ with $d\geq2$. Our main results include some recursive formulas
for the moment measures of $\xi$, with connections to the uniform Brownian
tree, a Brownian snake representation of Palm measures, continuity properties
of conditional moment densities, leading by duality to strongly continuous
versions of the multivariate Palm distributions, and a local approximation of
$\xi_t$ by a stationary cluster $\tilde{\eta}$ with nice continuity and scaling
properties. This all leads up to an asymptotic description of the conditional
distribution of $\xi_t$ for a fixed $t>0$, given that $\xi_t$ charges the
$\varepsilon$-neighborhoods of some points $x_1,\ldots,x_n\in \mathsf{R}^d$. In
the limit as $\varepsilon\to0$, the restrictions to those sets are
conditionally independent and given by the pseudo-random measures $\tilde{\xi}$
or $\tilde{\eta}$, whereas the contribution to the exterior is given by the
Palm distribution of $\xi_t$ at $x_1,\ldots,x_n$. Our proofs are based on the
Cox cluster representations of the historical process and involve some delicate
estimates of moment densities.


title: Spin-statistics-quantum number connection and supersymmetry

abstract:
  The analogy between the Skyrme and Higgs field leads to the conjecture that
all fermions are skyrmions and thus always carry conserved quantum numbers,
which are identified with baryon or lepton quantum numbers. This connection
between spin and quantum numbers, which parallels the connection between spin
and statistics due to the Pauli principle, may explain why supersymmetry has
not been observed. Creation of s-particles at higher than present energies due
to a breakdown of the Skyrme mechanism might imply the violation of the
exclusion principle.


title:
Search for correlations between solar flares and decay rate of
  radioactive nuclei

abstract:
  The deacay rate of three different radioactive sources 40K, 137Cs and natTh
has been measured with NaI and Ge detectors. Data have been analyzed to search
for possible variations in coincidence with the two strongest solar flares of
the years 2011 and 2012. No significant deviations from standard expectation
have been observed, with a few 10-4 sensitivity. As a consequence, we could not
find any effect like that recently reported by Jenkins and Fischbach: a few per
mil decrease in the decay rate of 54Mn during solar flares in December 2006.


title: Validasi data dengan menggunakan objek lookup pada borland delphi 7.0

abstract:
  Developing an application with some tables must concern the validation of
input (specially in Table Child). In order to maximize the accuracy and data
input validation. Its called lookup (took data from other dataset). There are
two ways to look up data from Table Parent: 1) Using Objects (DBLookupComboBox
and DBookupListBox), or 2) Arranging the properties of data types fields (shown
by using DBGrid). In this article is using Borland Delphi software (Inprise
product). The method is offered using 5 (five) practise steps: 1) Relational
Database Scheme, 2) Form Design, 3) Object DatabasesRelationships Scheme, 4)
Properties and Field Type Arrangement, and 5) Procedures. The result of this
paper are: 1) The relationship that using lookup objects are valid, and 2)
Delphi Lookup Objects can be used for 1-1, 1-N, and M-N relationship.


title: Embedding periodic maps on surfaces into those on $S^3$

abstract:
  Call a periodic map $h$ on the closed orientable surface $\Sigma_g$
extendable if $h$ extends to a periodic map over the pair $(S^3, \Sigma_g)$ for
possible embeddings $e: \Sigma_g\to S^3$.
  We determine the extendabilities for all periodical maps on $\Sigma_2$. The
results involve various orientation preserving/reversing behalves of the
periodical maps on the pair $(S^3, \Sigma_g)$. To do this we first list all
periodic maps on $\Sigma_2$, and indeed we exhibit each of them as a
composition of primary and explicit symmetries, like rotations, reflections and
antipodal maps, which itself should be an interesting piece.
  A by-product is that for each even $g$, the maximum order periodic map on
$\Sigma_g$ is extendable, which contrasts sharply to the situation in
orientation preserving category.


title: A Combination Framework for Complexity

abstract:
  In this paper we present a combination framework for polynomial complexity
analysis of term rewrite systems. The framework covers both derivational and
runtime complexity analysis. We present generalisations of powerful complexity
techniques, notably a generalisation of complexity pairs and (weak) dependency
pairs. Finally, we also present a novel technique, called dependency graph
decomposition, that in the dependency pair setting greatly increases
modularity. We employ the framework in the automated complexity tool TCT. TCT
implements a majority of the techniques found in the literature, witnessing
that our framework is general enough to capture a very brought setting.


title:
A Comparison of Relaxations of Multiset Cannonical Correlation Analysis
  and Applications

abstract:
  Canonical correlation analysis is a statistical technique that is used to
find relations between two sets of variables. An important extension in pattern
analysis is to consider more than two sets of variables. This problem can be
expressed as a quadratically constrained quadratic program (QCQP), commonly
referred to Multi-set Canonical Correlation Analysis (MCCA). This is a
non-convex problem and so greedy algorithms converge to local optima without
any guarantees on global optimality. In this paper, we show that despite being
highly structured, finding the optimal solution is NP-Hard. This motivates our
relaxation of the QCQP to a semidefinite program (SDP). The SDP is convex, can
be solved reasonably efficiently and comes with both absolute and
output-sensitive approximation quality. In addition to theoretical guarantees,
we do an extensive comparison of the QCQP method and the SDP relaxation on a
variety of synthetic and real world data. Finally, we present two useful
extensions: we incorporate kernel methods and computing multiple sets of
canonical vectors.


title:
A Constructive Epistemic Logic with Public Announcement
  (Non-Predetermined Possibilities)

abstract:
  We argue that the notion of epistemic \emph{possible worlds} in
constructivism (intuitionism) is not as the same as it is in classic view, and
there are possibilities, called non-predetermined worlds, which are ignored in
(classic) Epistemic Logic. Regarding non-predetermined possibilities, we
propose a constructive epistemic logic and prove soundness and completeness
theorems for it. We extend the proposed logic by adding a public announcement
operator. To declare the significance of our work, we formulate the well-known
Surprise Exam Paradox, $\mathbf{SEP}$, via the proposed constructive epistemic
logic and then put forward a solution for the paradox. We clarify that the
puzzle in the $\mathbf{SEP}$ is because of students'(wrong) assumption that the
day of the exam is necessarily predetermined.


title:
Work distribution in time-dependent logarithmic-harmonic potential:
  exact results and asymptotic analysis

abstract:
  We investigate the distribution of work performed on a Brownian particle in a
time-dependent asymmetric potential well. The potential has a harmonic
component with time-dependent force constant and a time-independent logarithmic
barrier at the origin. For arbitrary driving protocol, the problem of solving
the Fokker-Planck equation for the joint probability density of work and
particle position is reduced to the solution of the Riccati differential
equation. For a particular choice of the driving protocol, an exact solution of
the Riccati equation is presented. Asymptotic analysis of the resulting
expression yields the tail behavior of the work distribution for small and
large work values. In the limit of vanishing logarithmic barrier, the work
distribution for the breathing parabola model is obtained.


title:
Bayesian inference for the multivariate skew-normal model: a Population
  Monte Carlo approach

abstract:
  Frequentist and likelihood methods of inference based on the multivariate
skew-normal model encounter several technical difficulties with this model. In
spite of the popularity of this class of densities, there are no broadly
satisfactory solutions for estimation and testing problems. A general
population Monte Carlo algorithm is proposed which: 1) exploits the latent
structure stochastic representation of skew-normal random variables to provide
a full Bayesian analysis of the model and 2) accounts for the presence of
constraints in the parameter space. The proposed approach can be defined as
weakly informative, since the prior distribution approximates the actual
reference prior for the shape parameter vector. Results are compared with the
existing classical solutions and the practical implementation of the algorithm
is illustrated via a simulation study and a real data example. A generalization
to the matrix variate regression model with skew-normal error is also
presented.


title: On summation of Kapteyn series

abstract:
  We consider the summation of Kapteyn series of several kinds and obtain some
relations among the sums. We paid special attention to cases when sums are
transcendental functions. Their asymptotic behaviors are obtained. In some
cases the integral representations for sums are found. As an application we
find the radiation free lifetime of an electron moving in a constant external
field. It is noted that the laboratory lifetime increases with energy for
ultrarelativistic electron in ultrastrong external field.


title: Lefschetz numbers of symplectic involutions on arithmetic groups

abstract:
  The reduced norm-one group G of a central simple algebra is an inner form of
the special linear group, and an involution on the algebra induces an
automorphism of G. We study the action of such automorphisms in the cohomology
of arithmetic subgroups of G. The main result is a precise formula for
Lefschetz numbers of automorphisms induced by involutions of symplectic type.
Our approach is based on a careful study of the smoothness properties of group
schemes associated with orders in central simple algebras. Along the way we
also derive an adelic reformulation of Harder's Gauss-Bonnet Theorem.


title:
Tunneling decay of two interacting bosons in an asymmetric double-well
  potential: A spectral approach

abstract:
  We study the full-fledged microscopic dynamics of two interacting, ultracold
bosons in a one- dimensional double-well potential, through the numerically
exact diagonalization of the many-body Hamiltonian. With the particles
initially prepared in the left well, we increase the width of the right well in
subsequent trap realizations and witness how the tunneling oscillations evolve
into particle loss. In this closed system, we analyze the spectral signatures
of single- and two-particle tunneling for the entire range of repulsive
interactions. We conclude that for comparable widths of the two wells,
pair-wise tunneling of the bosons may be realized for specific system
parameters. In contrast, the decay process (corresponding to a broad right
well) is dominated by uncorrelated single-particle decay.


title: High-Altitude Ballooning Program at the Indian Institute of Astrophysics

abstract:
  We have begun a program of high altitude ballooning at the Indian Institute
of Astrophysics, Bangalore. Recent advances in balloons as well as in
electronics have made possible scientific payloads at costs accessible to
university departments. The primary purpose of this activity is to test
low-cost ultraviolet (UV) payloads for eventual space flight, but to also
explore phenomena occurring in the upper atmosphere, including sprites and
meteorite impacts, using balloon-borne payloads. This paper discusses the
results of three tethered balloon experiments carried out at the CREST campus
of IIA, Hosakote and our plans for the future. We also describe the stages of
payload development for these experiments.


title:
Monoids $\mathrm{Mon}\langle
  a,b:a^{\alpha}b^{\beta}a^{\gamma}b^{\delta}=b\rangle$ admit finite complete
  rewriting systems

abstract:
  We prove that every monoid $\mathrm{Mon}\langle
a,b:a^{\alpha}b^{\beta}a^{\gamma}b^{\delta}=b\rangle$ admits a finite complete
rewriting system. Furthermore we prove that $\mathrm{Mon}\langle
a,b:ab^2a^2b^2=b\rangle$ is non-hopfian, providing an example of a finitely
presented non-residually finite monoid with linear Dehn function.


title:
Spin-valley lifetimes in a silicon quantum dot with tunable valley
  splitting

abstract:
  Although silicon is a promising material for quantum computation, the
degeneracy of the conduction band minima (valleys) must be lifted with a
splitting sufficient to ensure formation of well-defined and long-lived spin
qubits. Here we demonstrate that valley separation can be accurately tuned via
electrostatic gate control in a metal-oxide-semiconductor quantum dot,
providing splittings spanning 0.3 - 0.8 meV. The splitting varies linearly with
applied electric field, with a ratio in agreement with atomistic tight-binding
predictions. We demonstrate single-shot spin readout and measure the spin
relaxation for different valley configurations and dot occupancies, finding
one-electron lifetimes exceeding 2 seconds. Spin relaxation occurs via phonon
emission due to spin-orbit coupling between the valley states, a process not
previously anticipated for silicon quantum dots. An analytical theory describes
the magnetic field dependence of the relaxation rate, including the presence of
a dramatic rate enhancement (or hot-spot) when Zeeman and valley splittings
coincide.


title: On designing heteroclinic networks from graphs

abstract:
  Robust heteroclinic networks are invariant sets that can appear as attractors
in symmetrically coupled or otherwise constrained dynamical systems. These
networks may have a very complicated structure that is poorly understood and
determined to a large extent by the constraints and dimension of the system. As
these networks are of great interest as dynamical models of biological and
cognitive processes, it is useful to understand how particular graphs can be
realised as robust heteroclinic networks that are attracting. This paper
presents two methods of realizing arbitrarily complex directed graphs as robust
heteroclinic networks for flows generated by ODEs---we say the ODEs {\em
realise} the graphs as heteroclinic networks between equilibria that represent
the vertices. Suppose we have a directed graph on $n_v$ vertices with $n_e$
edges. The "simplex realisation" embeds the graph as an invariant set of a flow
on an $(n_v-1)$-simplex. This method realises the graph as long as it is one-
and two-cycle free. The "cylinder realisation" embeds a graph as an invariant
set of a flow on a $(n_e+1)$-dimensional space. This method realises the graph
as long as it is one-cycle free. In both cases we find the graph as an
invariant set within an attractor, and discuss some illustrative examples,
including the influence of noise and parameters on the dynamics. In particular
we show that the resulting heteroclinic network may or may not display "memory"
of the vertices visited.


title:
$\mathcal{J}^{\ast}=\mathcal{D}^{\ast}$ need not hold in finite
  semigroups

abstract:
  We provide an example of minimum size of a finite semigroup with
$\mathcal{J}^{\ast}\neq\mathcal{D}^{\ast}$. We introduce the notion of starred
stability and prove that every starred stable semigroup has
$\mathcal{J}^{\ast}=\mathcal{D}^{\ast}$.


title:
Electronic friction for a slow impurity in an inhomogeneous metallic
  system

abstract:
  The stopping power of a metal for a slow structureless impurity varies
linearly with projectile velocity. We show that the coefficient of this linear
behavior (friction coefficient) is determined exactly in a static ensemble
Kohn-Sham scheme, by extension of the Shifted Fermi Surface procedure
originally derived for an homogeneous jellium. We prove that the friction
coefficient is determined only by local characteristics of the system. The
error incurred when adding a spurious non-local contribution is illustrated for
a simple 1D model.


title:
Vacancy diffusion in colloidal crystals as determined by dynamical
  density-functional theory and the phase-field-crystal model

abstract:
  A two-dimensional crystal of repulsive dipolar particles is studied in the
vicinity of its melting transition by using Brownian dynamics computer
simulation, dynamical density functional theory and phase-field crystal
modelling. A vacancy is created by taking out a particle from an equilibrated
crystal and the relaxation dynamics of the vacancy is followed by monitoring
the time-dependent one-particle density. We find that the vacancy is quickly
filled up by diffusive hopping of neighbouring particles towards the vacancy
center. We examine the temperature dependence of the diffusion constant and
find that it decreases with decreasing temperature in the simulations. This
trend is reproduced by the dynamical density functional theory. Conversely, the
phase field crystal calculations predict the opposite trend. Therefore, the
phase-field model needs a temperature-dependent expression for the mobility to
predict trends correctly.


title:
Cauchy problem for dissipative H\"older solutions to the incompressible
  Euler equations

abstract:
  We consider solutions to the Cauchy problem for the incompressible Euler
equations on the 3-dimensional torus which are continuous or H\"older
continuous for any exponent $\theta<\frac{1}{16}$. Using the techniques
introduced in \cite{DS12} and \cite{DS12H}, we prove the existence of
infinitely many (H\"older) continuous initial vector fields starting from which
there exist infinitely many (H\"older) continuous solutions with preassigned
total kinetic energy.


title: Jewels on a wall ring

abstract:
  We construct a stable domain wall ring with lump beads on it in a baby Skyrme
model with a potential consisting of two terms linear and quadratic in fields.


title:
Isotropic inelastic and superelastic collisional rates in a multiterm
  atom

abstract:
  The spectral line polarization of the radiation emerging from a magnetized
astrophysical plasma depends on the state of the atoms within the medium, whose
determination requires considering the interactions between the atoms and the
magnetic field, between the atoms and photons (radiative transitions), and
between the atoms and other material particles (collisional transitions). In
applications within the framework of the multiterm model atom (which accounts
for quantum interference between magnetic sublevels pertaining either to the
same J-level or to different J-levels within the same term) collisional
processes are generally neglected when solving the master equation for the
atomic density matrix. This is partly due to the lack of experimental data
and/or of approximate theoretical expressions for calculating the collisional
transfer and relaxation rates (in particular the rates for interference between
sublevels pertaining to different J-levels, and the depolarizing rates due to
elastic collisions). In this paper we formally define and investigate the
transfer and relaxation rates due to isotropic inelastic and superelastic
collisions that enter the statistical equilibrium equations of a multiterm
atom. Under the hypothesis that the atom-collider interaction can be described
by a dipolar operator, we provide expressions that relate the collisional rates
for interference between different J-levels to the usual collisional rates for
J-level populations. Finally, we apply the general equations to the case of a
two-term atom with unpolarized lower term, illustrating the impact of inelastic
and superelastic collisions on scattering polarization through radiative
transfer calculations in a slab of stellar atmospheric plasma anisotropically
illuminated by the photospheric radiation field.


title: Moment vanishing of piecewise solutions of linear ODEs

abstract:
  We consider the "moment vanishing problem" for a general class of
piecewise-analytic functions which satisfy on each continuity interval a linear
ODE with polynomial coefficients. This problem, which essentially asks how many
zero first moments can such a (nonzero) function have, turns out to be related
to several difficult questions in analytic theory of ODEs (Poincare's
Center-Focus problem) as well as in Approximation Theory and Signal Processing
("Algebraic Sampling"). While the solution space of any particular ODE admits
such a bound, it will in the most general situation depend on the coefficients
of this ODE. We believe that a good understanding of this dependence may
provide a clue for attacking the problems mentioned above.
  In this paper we undertake an approach to the moment vanishing problem which
utilizes the fact that the moment sequences under consideration satisfy a
recurrence relation of fixed length, whose coefficients are polynomials in the
index. For any given operator, we prove a general bound for its moment
vanishing index. We also provide uniform bounds for several operator families.


title: A journey into localization, integrability and thermalization

abstract:
  We present here the results obtained during my PhD work. We report the study
of the many body localization transition in a spin chain and the breaking of
ergodicity measured in terms of return probability in a state evolution.
Moreover, we introduce the Richardson model, an exactly solvable model, that
turns out to be suitable for investigating the many-body localized phase. Then
we turn to the analysis of the quench problem in an ensemble of random
matrices. We analyze the thermalization properties and the validity of the
Eigenstate Thermalization Hypothesis for the typical case, where the quench
parameter explicitly breaks a Z_2 symmetry.


title:
Graphene-Ferroelectric Hybrid Structure for Flexible Transparent
  Electrodes

abstract:
  Graphene has exceptional optical, mechanical and electrical properties,
making it an emerging material for novel optoelectronics, photonics and for
flexible transparent electrode applications. However, the relatively high sheet
resistance of graphene is a major constrain for many of these applications.
Here we propose a new approach to achieve low sheet resistance in large-scale
CVD monolayer graphene using non-volatile ferroelectric polymer gating. In this
hybrid structure, large-scale graphene is heavily doped up to 3{\times}1013
cm-2 by non-volatile ferroelectric dipoles, yielding a low sheet resistance of
120 {\Omega}{\Box} at ambient conditions. The graphene-ferroelectric
transparent conductors (GFeTCs) exhibit more than 95% transmittance from the
visible to the near infrared range owing to the highly transparent nature of
the ferroelectric polymer. Together with its excellent mechanical flexibility,
chemical inertness and the simple fabrication process of ferroelectric
polymers, the proposed GFeTCs represent a new route towards large-scale
graphene based transparent electrodes and optoelectronics.


title: Elastic Constants of Incommensurate Solid 4He

abstract:
  We study the elastic properties of incommensurate solid 4He in the limit of
zero temperature. Specifically, we calculate the pressure dependence of the
five elastic constants (C11, C12, C13, C33, and C44), longitudinal and
transversal speeds of sound, and the T = 0 Debye temperature of incommensurate
and commensurate hcp 4He using the diffusion Monte Carlo method. Our results
show that under compression the commensurate crystal is globally stiffer than
the incommensurate, however at pressures close to melting (i.e. P ~ 25 bars)
some of the elastic constants accounting for strain deformations of the hcp
basal plane (C12 and C13) are slightly larger in the incommensurate solid.
Also, we find that upon the introduction of tiny concentrations of point
defects the shear modulus of 4He (C44) undergoes a small reduction.


title:
Optical eigenmodes in plane arrays of cylindrical waveguides. Analysis
  by means of multiple Mie scattering formalism and phenomenological model

abstract:
  We consider a plane periodical array of parallel cylindrical waveguides with
evanescent coupling between them. A new method for calculating the isofrequency
curves based on the multiple Mie scattering formalism (MMSF) is developed. This
method is compared with the phenomenological model. The derivation of the
phenomenological model by means of the MMSF is performed. The formulae for
calculation of parameters of the phenomenological model are derived, such as
propagation constants and coupling constants.


title:
Radially symmetric solutions to the H\`enon-Lane-Emden system on the
  critical hyperbola

abstract:
  We use variational methods to study the existence of nontrivial and radially
symmetric solutions to the H\`enon-Lane-Emden system with weights, when the
exponents involved lie on the "critical hyperbola". We also discuss qualitative
properties of solutions and nonexistence results.


title: Metamaterial atom with multijunction superconducting structure

abstract:
  We present results of numerical simulations of a metamaterial element
(meta-atom) for planar negative media based on cuprate Josephson junctions. The
proposed circuit consists of two coupled resonators: "magnetic dipole" and
"electric dipole". The first one is a superconducting spiral resonator with
multijunction superconducting structure - SQIF (SQIF - superconducting quantum
interference filter), and the second one is a comb-shape resonator made from
normal metal film. We show, that in comparison with passive metal resonators,
the superconducting resonator with Josephson junctions (magnetic dipole) can be
tuned by external magnetic field due to magnetic dependence of Josephson
inductance. The simulated characteristics of one-dimensional planar negative
media are discussed.


title:
Production of charged $\rho$ meson in bottom hadron charmed decays and
  the effect of the finite width correction of the $\rho$ meson

abstract:
  We calculate the branching ratio of a bottom hadron decaying into a charmed
hadron and a charged $\rho$ meson within the QCD factorization approach. We
consider the effect of the finite width correction of the $\rho$ meson. Our
numerical calculation shows an obvious correction because of this effect. We
find that the finite width effect of the $\rho$ meson reduces the branching
ratios by about 9% to 11% for bottom meson decay channels:
$B^+\to\bar{D^0}\rho^+$, $B^0\to D^-\rho^+$, and $B^0_s\to D^-_s\rho^+$, and
increases the branching ratio by about 10% for
$\Lambda_b^0\to\Lambda_c^+\rho^-$.


title: Outflows of stars due to quasar feedback

abstract:
  Quasar feedback outflows are commonly invoked to drive gas out of galaxies in
the early gas-rich epoch to terminate growth of galaxies. Here we present
simulations that show that AGN feedback may drive not only gas but also stars
out of their host galaxies under certain conditions. The mechanics of this
process is as following: (1) AGN-driven outflows accelerate and compress gas
filling the host galaxy; (2) the accelerated dense shells become
gravitationally unstable and form stars on radial trajectories. For the
spherically symmetric initial conditions explored here, the black hole needs to
exceed the host's M_sigma mass by a factor of a few to accelerate the shells
and the new stars to escape velocities. We discuss potential implications of
these effects for the host galaxies: (i) radial mixing of bulge stars with the
rest of the host; (ii) contribution of quasar outflows to galactic fountains as
sources of high-velocity clouds; (iii) wholesale ejection of hyper velocity
stars out of their hosts, giving rise to type II supernovae on galactic
outskirts, and contributing to reionization and metal enrichment of the
Universe; (iv) bulge erosion and even complete destruction in extreme cases
resulting in overweight or bulgeless SMBHs.


title:
Experimental search for solar hidden photons in the eV energy range
  using kinetic mixing with photons

abstract:
  We have searched for solar hidden photons in the eV energy range using a
dedicated hidden photon detector. The detector consisted of a parabolic mirror
with a diameter of 500mm and a focal length of 1007mm installed in a vacuum
chamber, and a photomultiplier tube at its focal point. The detector was
attached to the Tokyo axion helioscope, Sumico which has a mechanism to track
the sun. From the result of the measurement, we found no evidence for the
existence of hidden photons and set a limit on the photon-hidden photon mixing
parameter \chi depending on the hidden photon mass m_{\gamma '}.


title: Cyclotrons for high-intensity beams

abstract:
  This paper reviews the important physical and technological aspects of
cyclotrons for the acceleration of high-intensity beams. Special emphasis is
given to the discussion of beam loss mechanisms and extraction schemes.


title: Complex fragment emission in low energy light-ion reactions

abstract:
  Inclusive energy spectra of the complex fragments (3 $\leq$ Z $\leq$ 5)
emitted in the reactions $^{12}$C (77 MeV)+ $^{28}$Si, $^{11}$B (64 MeV)+
$^{28}$Si and $^{12}$C (73 MeV)+ $^{27}$Al (all having the same excitation
energy of $ \sim$ 67 MeV), have been measured in the angular range of
10$^\circ$ $\lesssim \theta_{lab} \lesssim$ 60$^\circ$. The fully energy damped
(fusion-fission) and the partially energy damped (deep inelastic) components of
the fragment energy spectra have been extracted. It has been found that the
yields of the fully energy damped fragments for all the above reactions are in
conformity with the respective statistical model predictions. The time scales
of various deep inelastic fragment emissions have been extracted from the
angular distribution data. The angular momentum dissipation in deep inelastic
collisions has been estimated from the data and it has been found to be close
to the corresponding sticking limit value.


title:
Reflection and refraction process of spinwave in a
  ferromagnet/frustrated ferromagnet junction system

abstract:
  Frustration introduces a nontrivial dispersion relation of spinwave even in a
ferromagnetic phase in a spin system. We study the reflection and refraction
process of spinwaves in the ferromagnet/frustrated ferromagnet junction system
by using the Holstein-Primakoff spinwave expansion and taking the large-S
limit. We discuss the relation between the incident angle and refraction angle
of spinwave, namely, the Snell's low of spinwave. As concrete examples of
frustrated ferromagnets, we study the fully polarized ferromagnet phases in the
J1-J2 chains and the J1-J2 model on the square lattice. The interesting
refraction processes, such as the splitting of the incident spinwave and the
negative refraction, are discussed. We also study the transmittance and
reflectance in these concrete models.


title: World Space Observatory-Ultraviolet: ISSIS, the imaging instrument

abstract:
  The Imaging and Slitless Spectroscopy Instrument (ISSIS) will be flown as
part of the Science Instrumentation in the World Space Observatory-Ultraviolet
(WSO-UV). ISSIS will be the first UV imager to operate in a high Earth orbit
from a 2-m class space telescope. In this contribution, the science driving to
ISSIS design, as well as main characteristics of ISSIS are presented.


title:
Circuit proposition for copying the value of a resistor into a
  memristive device supported by HSPICE simulation

abstract:
  Memristor is the fourth fundamental passive circuit element with potential
applications in development of analog memories, artificial brains (with the
capacity of hardware training) and neuro-science. In most of these applications
the memristance of the device should be set to the desired value, which is
currently performed by trial and error. The aim of this paper is to propose a
circuit for copying the value of the given resistor into a memristive device.
HSPICE simulations are also presented to confirm the efficiency of the proposed
circuit.


title:
Critical Behavior of Percolation Process Influenced by Random Velocity
  Field: One-Loop Approximation

abstract:
  Using perturbative renormalization group we investigate the influence of
random velocity field on the critical behavior of directed bond percolation
process near its second-order phase transition between absorbing and active
phase. Antonov-Kraichnan model with finite correlation time is used for
description of advecting velocity field.
  The field-theoretic renormalization group approach is applied for getting
information about asymptotic large scale behavior of the model under
consideration. The model is analyzed near its critical dimension through
three-parameter expansion in {\epsilon}, {\delta}, {\eta}, where {\epsilon} is
the deviation from the Kolmogorov scaling, {\delta} is the deviation from the
critical space dimension {d_c} and {\eta} is the deviation from the parabolic
dispersion law for the velocity correlator. Fixed points with corresponding
regions of stability are determined to the leading order in the perturbation
scheme.


title: Image Denoising Using Interquartile Range Filter with Local Averaging

abstract:
  Image denoising is one of the fundamental problems in image processing. In
this paper, a novel approach to suppress noise from the image is conducted by
applying the interquartile range (IQR) which is one of the statistical methods
used to detect outlier effect from a dataset. A window of size kXk was
implemented to support IQR filter. Each pixel outside the IQR range of the kXk
window is treated as noisy pixel. The estimation of the noisy pixels was
obtained by local averaging. The essential advantage of applying IQR filter is
to preserve edge sharpness better of the original image. A variety of test
images have been used to support the proposed filter and PSNR was calculated
and compared with median filter. The experimental results on standard test
images demonstrate this filter is simpler and better performing than median
filter.


title:
CSIT Sharing over Finite Capacity Backhaul for Spatial Interference
  Alignment

abstract:
  Cellular systems that employ time division duplexing (TDD) transmission are
good candidates for implementation of interference alignment (IA) in the
downlink since channel reciprocity enables the estimation of the channel state
by the base stations (BS) in the uplink phase. However, the interfering BSs
need to share their channel estimates via backhaul links of finite capacity. A
quantization scheme is proposed which reduces the amount of information
exchange (compared to conventional methods) required to achieve IA in a TDD
system. The scaling (with the transmit power) of the number of bits to be
exchanged between the BSs that is sufficient to preserve the multiplexing gain
of IA is derived.


title:
The filling factor - radius relation for 58 HII regions across the disk
  of NGC6946

abstract:
  Using the OSIRIS tunable narrow band imager on the 10.4m GTC (La Palma) we
have mapped the SAB(rs)cd galaxy NGC 6946 over a 7.3x7.5 square arcminutes
field in the emission lines of the [SII]\lambda\lambda, 6717, 6731 doublet, and
in H\alpha. From these maps we have produced catalogs of the H\alpha
luminosities and effective radii of 557 HII regions across the disk, and
derived the [SII] emission line ratios of 370 of these. The H\alpha
observations were used to derive the mean luminosity-weighted electron
densities for the regions of the sample, while the [SII] line ratios allowed us
to derive values of the in situ electron densities in the denser zones from
which the major fraction of the radiation in these lines is emitted, for 58 of
the regions. This is by far the largest data set of its kind for a single
galaxy. A classical two phase model is used to derive the filling factors of
the regions. We find that although the mean electron density decreases with the
square root of the radius of the regions, the in situ density is essentially
independent of this radius. Thus the filling factor falls systematically, as
the radius and the luminosity of the regions increases, with a power law of
exponent -2.23 between filling factor and radius. These measurements should
enhance the perspectives for more refined physical models of HII regions.


title:
Improving Mixed-Criticality System Consistency and Behavior on
  Multiprocessor Platforms by Means of Multi-Moded Approaches

abstract:
  Recent research in the domain of real-time scheduling theory has tackled the
problem of scheduling mixed-criticality systems upon uniprocessor or
multiprocessor platforms, with the main objective being to respect the
timeliness of the most critical tasks, at the expense of the requirements of
the less critical ones. In particular, the less critical tasks are carelessly
discarded when the computation demand of (some of) the high critical tasks
increases. This might nevertheless result in system failure, as these less
critical tasks could be accessing data, the consistency of which should be
preserved. In this paper, we address this problem and propose a method to
cautiously handle task suspension. Furthermore, it is usually assumed that the
less critical tasks will never be re-enabled once discarded. In this paper, we
also address this concern by proposing an approach to re-enable the less
critical tasks, without jeopardizing the timeliness of the high critical ones.
The suggested approaches apply to systems having two or more criticality
levels.


title: A universal, memory-assisted entropic uncertainty relation

abstract:
  We derive a new memory-assisted entropic uncertainty relation for
non-degenerate Hermitian observables where both quantum correlations, in the
form of conditional von Neumann entropy, and quantum discord between system and
memory play an explicit role. Our relation is `universal', in the sense that it
does not depend on the specific observable, but only on properties of the
quantum state. We contrast such an uncertainty relation with previously known
memory-assisted relations based on entanglement and correlations. Further, we
present a detailed comparative study of entanglement- and discord-assisted
entropic uncertainty relations for systems of two qubits -- one of which plays
the role of the memory -- subject to several forms of independent quantum
noise, in both Markovian and non-Markovian regimes. We thus show explicitly
that, partly due to the ubiquity and inherent resilience of quantum discord,
discord-tightened entropic uncertainty relations often offer a better estimate
of the uncertainties in play.


abstract:
  The unicity of real Picard-Vessiot fields for differential modules over a
real differential field is proved.


title: Strong fluctuation theorem for nonstationary nonequilibrium systems

abstract:
  We introduce a finite-time detailed fluctuation theorem for the environmental
entropy of the form $\tilde P(\Delta S_{env}) = e^{\Delta S_{env}} \tilde
P(-\Delta S_{env})$ for an appropriately weighted probability density of the
external entropy production in the environment. The fluctuation theorem is
valid for nonequilibrium systems with constant rates starting with an arbitrary
initial probability distribution. We discuss the implication of this new
relation for the case of a temperature quench in classical equilibrium systems.
The fluctuation theorem is tested numerically for a Markov jump process with
six states and for a surface growth model.


title:
Loop Quantum Cosmology of Bianchi I Model in $\bar{\mu}$ and
  $\bar{\mu}'$ Schemes with Higher Order Holonomy Corrections

abstract:
  The detailed formulation of loop quantum cosmology with higher order holonomy
corrections has been constructed recently in the homogeneous and isotropic
spacetime, yet it is important to extend the higher order holonomy corrections
to include the effects of anisotropy which typically grow during the collapsing
phase. In this paper we investigate the Bianchi I model in $\bar{\mu}'$ scheme
which truly captures the regularization of the Hamiltonian constraint. To
compare with the earlier works and provide a comparison with the $\bar{\mu}'$
scheme, we also investigate the $\bar{\mu}$ scheme although it has many
disadvantages. First we construct the effective dynamics with higher order
holonomy corrections in a massless scalar field, then we extend it to the
inclusion of arbitrary matter. Besides that, we also analyze the behavior of
the anisotropy during the evolution of the universe. We find that in the
$\bar{\mu}'$ scheme, the singularity is never approached and the quantum bounce
is generic as in the isotropic case, regardless of the order of the holonomy
corrections. Some differences in the bouncing phase of the two schemes are also
found out. It is also shown that in the two schemes the behavior of the
anisotropy is not the same before and after the bounce.


title:
Limits on the source properties of FR-I galaxies from high-energy
  neutrino and gamma observations

abstract:
  Active galactic nuclei (AGN) are believed to be the source of ultra high
energy cosmic rays (UHECRs). Particles are assumed to be accelerated in the
accretion disk and the plasma jets, produced due to conservation of angular
momentum, to the highest energies, where they interact with each other and
produce pions, which decay among others in neutrinos. For a known cosmic ray
spectral behavior, the main parameters in the calcula- tion of the neutrino
flux from proton-proton interactions are the target density nH and the ratio of
electrons to protons fe . Using most recent neutrino flux limits from IceCube
point source searches, we set limits on the target densities for 33 FR-I
galaxies. The densities are shown to be smaller than 30 cm^{-3} to 2000
cm^{-3}, depending on the source and when using a fixed electron to proton
ratio of f_{e} = 0.1. This implies that some cosmic ray acceleration sites,
espe- cially those close to the core of the AGN, can already be excluded, or
else that the ratio of electrons to protons deviates significantly from the
commonly used value of 0.1. For Centaurus A (Cen A) and Messier 87 (M 87) we
use Fermi observations to model the {\gamma}-flux, the neutrino flux and the
resulting target density. The detec- tion of these neutrinos will help to find
information about acceleration processes in the source.


title: Do floating orbits in extreme mass ratio binary black holes exist?

abstract:
  This paper examines the possibility of floating or non-decaying orbits for
extreme mass ratio binary black holes. In the adiabatic approximation, valid in
the extreme mass ratio case, if the orbital flux lost due to gravitational
radiation reaction is compensated for by the orbital flux gained from the spins
of the black holes via superradiant scattering (or, equivalently, tidal
acceleration) the orbital decay would be stalled, causing the binary to
"float". We show that this flux balance is not, in practice, possible for
extreme mass ratio binary black holes with circular equatorial orbits;
furthermore, adding eccentricity and inclination to the orbits will not
significantly change this null result, thus ruling out the possibility of
floating orbits for extreme mass ratio binary black holes. We also argue that
binaries consisting of material bodies dense and massive enough to generate
gravitational waves detectable by any kind of gravitational wave detector are
also unlikely to float. Using a multipolar analysis, we show that a non-Kerr
spacetime which could produce a floating orbit (given the same amount of tidal
acceleration as in the case of a Kerr black hole) would need to be rapidly
rotating prolate spheroid, which would be an exotic object indeed.


title: The record method for two and three dimensional parameters random fields

abstract:
  Let $S$ be a regular set of $\R^d$ and $X : S\rightarrow \R$ be Gaussian
field with regular paths. In order to give bound to the tail of the
distribution of the maximum, we use the record method of Mercadier. We present
some new form in dimension 2 and extend it to dimension 3 using the result of
the expectation of the absolute value of quadratic forms by Li and Wei.
Comparison with other methods is conducted.


title:
Long-term spectropolarimetric monitoring of the cool supergiant
  Betelgeuse

abstract:
  We report on a long-term monitoring of the cool supergiant Betelgeuse, using
the NARVAL and ESPaDOnS high-resolution spectropolarimeters, respectively
installed at Telescope Bernard Lyot (Pic du Midi Observatory, France) and at
the Canada-France-Hawaii Telescope (Mauna Kea Observatory, Hawaii). The data
set, constituted of circularly polarized (Stokes V) and intensity (Stokes I)
spectra, was collected between 2010 and 2012. We investigate here the temporal
evolution of magnetic field, convection and temperature at photospheric level,
using simultaneous measurements of the longitudinal magnetic field component,
the core emission of the Ca II infrared triplet, the line-depth ratio of
selected photospheric lines and the radial velocity of the star.


title:
Applying the numerical method of steepest descent on multivariate
  oscillatory integrals in scattering theory

abstract:
  In this paper we demonstrate that the numerical method of steepest descent
fails when applied in a straight forward fashion to the most commonly occurring
highly oscillatory integrals in scattering theory. Through a polar change of
variables, however, the integral can be brought on a form that can be solved
efficiently using a mix of oscillatory integration techniques and classical
quadrature. The approach is described in detail and demonstrated numerically on
integration problems taken from applications.


title: Block-to-Block Distribution Matching

abstract:
  In this work, binary block-to-block distribution matching is considered. m
independent and uniformly distributed bits are mapped to n output bits
resembling a target product distribution. A rate R is called achieved by a
sequence of encoder-decoder pairs, if for m,n to infinity, (1) m/n approaches
R, (2) the informational divergence per bit of the output distribution and the
target distribution goes to zero, and (3) the probability of erroneous decoding
goes to zero. It is shown that the maximum achievable rate is equal to the
entropy of the target distribution. A practical encoder-decoder pair is
constructed that provably achieves the maximum rate in the limit. Numerical
results illustrate that the suggested system operates close to the limits with
reasonable complexity. The key idea is to internally use a fixed-to-variable
length matcher and to compensate underflow by random mapping and to cast an
error when overflow occurs.


title: Quantum homology of compact convex symplectic manifolds

abstract:
  We study the space of pseudo-holomorphic spheres in compact symplectic
manifolds with convex boundary. We show that the theory of Gromov-Witten
invariants can be extended to the class of semi-positive manifolds with convex
boundary. This leads to a deformation of intersection products on the absolute
and relative singular homologies. As a result, absolute and relative quantum
homology algebras are defined analogously to the case of closed symplectic
manifolds. In addition, we prove the Poincar\'{e}-Lefschetz duality for the
absolute and relative quantum homology algebras.


title: Type II superconductivity in SrPd2Ge2

abstract:
  Previous investigations have shown that SrPd2Ge2, a compound isostructural
with "122" iron pnictides but iron- and pnictogen-free, is a conventional
superconductor with a single s-wave energy gap and a strongly three-dimensional
electronic structure. In this work we reveal the Abrikosov vortex lattice
formed in SrPd2Ge2 when exposed to magnetic field by means of scanning
tunneling microscopy and spectroscopy. Moreover, by examining the differential
conductance spectra across a vortex and estimating the upper and lower critical
magnetic fields by tunneling spectroscopy and local magnetization measurements,
we show that SrPd2Ge2 is a strong type II superconductor with \kappa >>
sqrt(2). Also, we compare the differential conductance spectra in various
magnetic fields to the pair breaking model of Maki - de Gennes for dirty limit
type II superconductor in the gapless region. This way we demonstrate that the
type II superconductivity is induced by the sample being in the dirty limit,
while in the clean limit it would be a type I superconductor with \kappa\ <<
sqrt(2), in concordance with our previous study (T. Kim et al., Phys. Rev. B
85, (2012)).


title: On Genera of Curves from High-loop Generalized Unitarity Cuts

abstract:
  Generalized unitarity cut of a Feynman diagram generates an algebraic system
of polynomial equations. At high-loop levels, these equations may define a
complex curve or a (hyper-)surface with complicated topology. We study the
curve cases, i.e., a 4-dimensional L-loop diagram with (4L-1) cuts. The
topology of a complex curve is classified by its genus. Hence in this paper, we
use computational algebraic geometry to calculate the genera of curves from two
and three-loop unitarity cuts. The global structure of degenerate on-shell
equations under some specific kinematic configurations is also sketched. The
genus information can also be used to judge if a unitary cut solution could be
rationally parameterized.


title:
GENERIC formalism of a Vlasov-Fokker-Planck equation and connection to
  large-deviation principles

abstract:
  In this paper we discuss the connections between a Vlasov-Fokker-Planck
equation and an underlying microscopic particle system, and we interpret those
connections in the context of the GENERIC framework (\"Ottinger 2005). This
interpretation provides (a) a variational formulation for GENERIC systems, (b)
insight into the origin of this variational formulation, and (c) an explanation
of the origins of the conditions that GENERIC places on its constitutive
elements, notably the so-called degeneracy or non-interaction conditions. This
work shows how the general connection between large-deviation principles on one
hand and gradient-flow structures on the other hand extends to non-reversible
particle systems.


title: Hamiltonian Floer homology for compact convex symplectic manifolds

abstract:
  We construct absolute and relative versions of Hamiltonian Floer homology
algebras for strongly semi-positive compact symplectic manifolds with convex
boundary, where the ring structures are given by the appropriate versions of
the pair-of-pants products. We establish the absolute and relative
Piunikhin-Salamon-Schwarz isomorphisms between these Floer homology algebras
and the corresponding absolute and relative quantum homology algebras. As a
result, the absolute and relative analogues of the spectral invariants on the
group of compactly supported Hamiltonian diffeomorphisms are defined.