title: The effect of random positions for dipole hopping through a Rydberg gas

abstract:
  We calculate the effect of two kinds of randomness on the hopping of an
excitation through a nearly regular Rydberg gas. We present calculations for
how fast the excitation can hop away from its starting position for different
dimensional lattices and for different levels of randomness. We also examine
the asymptotic in time final position of the excitation to determine whether or
not the excitation can be localized. The one dimensional system is an example
of Anderson localization where the randomness is in the off-diagonal elements
although the long-range nature of the interaction leads to non-exponential
decay with distance. The two dimensional square lattice shows a mixture of
extended and localized states for large randomness while there is no visible
sign of localized states for weak randomness. The three dimensional cubic
lattice has few localized states even for strong randomness.


title:
Controllability of a swarm of topologically interacting autonomous
  agents

abstract:
  Controllability of complex networks has been the focal point of many recent
studies in the field of complexity. These landmark advances shed a new light on
the dynamics of natural and technological complex systems. Here, we analyze the
controllability of a swarm of autonomous self-propelled agents having a
topological neighborhood of interactions, applying the analytical tools
developed for the study of the controllability of arbitrary complex directed
networks. To this aim we thoroughly investigate the structural properties of
the swarm signaling network which is the information transfer channel
underpinning the dynamics of agents in the physical space. Our results show
that with 6 or 7 topological neighbors, every agent not only affects, but is
also affected by all other agents within the group. More importantly, still
with 6 or 7 topological neighbors, each agent is capable of full control over
all other agents. This finding is yet another argument justifying the
particular value of the number of topological neighbors observed in field
observations with flocks of starlings.


title: Numerical Detection of the Ergodicity Breaking in a Lattice Glass Model

abstract:
  We directly detect the ergodicity breaking in a lattice glass model by a
numerical simulation. The obtained results nicely agree with those by the
cavity method that the model on a regular random graph exhibits a dynamical
transition with the ergodicity breaking at an occupation density. The present
method invented for a numerical detection of the ergodicity breaking is
applicable to glassy systems in finite dimensions.


title: A property of the rule 150 elementary cellular automaton

abstract:
  We studied the rule 150 elementary cellular automaton in terms of the
distribution of the spacings of the singular values of the matieces obtained
from proper time evolutions patterns. The distribution has strong resembrance
to that of the random matrices which is derived from Painlev\'e V equation.
Some analytic results for the relative period of the ECS are also presented.


title: An Asynchronous Parallel Randomized Kaczmarz Algorithm

abstract:
  We describe an asynchronous parallel variant of the randomized Kaczmarz (RK)
algorithm for solving the linear system $Ax=b$. The analysis shows linear
convergence and indicates that nearly linear speedup can be expected if the
number of processors is bounded by a multiple of the number of rows in $A$.


title: A zero density result for the Riemann zeta function

abstract:
  In this article, we prove an explicit bound for $N(\sigma,T)$, the number of
zeros of the Riemann zeta function satisfying $\sigma < \Re s <1 $ and $0 < \Im
s < T$. This result provides a significant improvement over Rosser's bound for
$N(T)$ when used for estimating prime counting functions. For instance this is
applied to obtain new bounds for $\psi(x)$ (arXiv:1310.6374).


title:
Harmonic analysis of a class of reproducing kernel Hilbert spaces
  arising from groups

abstract:
  We study two extension problems, and their interconnections: (i) extension of
positive definite (p.d.) continuous functions defined on subsets in locally
compact groups $G$; and (ii) (in case of Lie groups $G$) representations of the
associated Lie algebras $La\left(G\right)$, i.e., representations of
$La\left(G\right)$ by unbounded skew-Hermitian operators acting in a
reproducing kernel Hilbert space $\mathscr{H}_{F}$ (RKHS). Our analysis is
non-trivial even if $G=\mathbb{R}^{n}$, and even if $n=1$. If
$G=\mathbb{R}^{n}$, (ii), we are concerned with finding systems of strongly
commuting selfadjoint operators $\left\{ T_{i}\right\} $ extending a system of
commuting Hermitian operators with common dense domain in $\mathscr{H}_{F}$.
  Specifically, we consider partially defined positive definite (p.d.)
continuous functions $F$ on a fixed group. From $F$ we then build a reproducing
kernel Hilbert space $\mathscr{H}_{F}$, and the operator extension problem is
concerned with operators acting in $\mathscr{H}_{F}$, and with unitary
representations of $G$ acting on $\mathscr{H}_{F}$. Our emphasis is on the
interplay between the two problems, and on the harmonic analysis of our RKHSs
$\mathscr{H}_{F}$.


title:
Transmon-based simulator of nonlocal electron-phonon coupling: A
  platform for observing sharp small-polaron transitions

abstract:
  We propose an analog superconducting quantum simulator for a one-dimensional
model featuring momentum-dependent (nonlocal) electron-phonon couplings of
Su-Schrieffer-Heeger and "breathing-mode" types. Because its corresponding
vertex function depends on both the electron- and phonon quasimomenta, this
model does not belong to the realm of validity of the Gerlach-L\"{o}wen theorem
that rules out any nonanalyticities in single-particle properties. The
superconducting circuit behind the proposed simulator entails an array of
transmon qubits and microwave resonators. By applying microwave driving fields
to the qubits, a small-polaron Bloch state with an arbitrary quasimomentum can
be prepared in this system within times several orders of magnitude shorter
than the typical qubit decoherence times. We demonstrate that in this system --
by varying the circuit parameters -- one can readily reach the critical
coupling strength required for observing the sharp transition from a
nondegenerate (single-particle) ground state corresponding to zero
quasimomentum ($K_{\textrm{gs}}=0$) to a twofold-degenerate small-polaron
ground state at nonzero quasimomenta $K_{\textrm{gs}}$ and $-K_{\textrm{gs}}$.
Through exact numerical diagonalization of our effective Hamiltonian, we show
how this nonanalyticity is reflected in the relevant single-particle properties
(ground-state energy, quasiparticle residue, average number of phonons). The
proposed setup provides an ideal testbed for studying quantum dynamics of
polaron formation in systems with strongly momentum-dependent electron-phonon
interactions.


title: STEP and fundamental physics

abstract:
  The Satellite Test of the Equivalence Principle (STEP) will advance
experimental limits on violations of Einstein's Equivalence Principle from
their present sensitivity of 2 parts in $10^{13}$ to 1 part in $10^{18}$
through multiple comparison of the motions of four pairs of test masses of
different compositions in a drag-free earth-orbiting satellite. We describe the
experiment, its current status, and its potential implications for fundamental
physics. Equivalence is at the heart of general relativity, our governing
theory of gravity, and violations are expected in most attempts to unify this
theory with the other fundamental interactions of physics, as well as in many
theoretical explanations for the phenomenon of dark energy in cosmology.
Detection of such a violation would be equivalent to the discovery of a new
force of nature. A null result would be almost as profound, pushing upper
limits on any coupling between standard-model fields and the new light degrees
of freedom generically predicted by these theories down to unnaturally small
levels.


title:
Anomaly detection in reconstructed quantum states using a
  machine-learning technique

abstract:
  The accurate detection of small deviations in given density matrices is
important for quantum information processing. Here we propose a new method
based on the concept of data mining. We demonstrate that the proposed method
can more accurately detect small erroneous deviations in reconstructed density
matrices, which contain intrinsic fluctuations due to the limited number of
samples, than a naive method of checking the trace distance from the average of
the given density matrices. This method has the potential to be a key tool in
broad areas of physics where the detection of small deviations of quantum
states reconstructed using a limited number of samples are essential.


title:
Common Information based Markov Perfect Equilibria for Linear-Gaussian
  Games with Asymmetric Information

abstract:
  We consider a class of two-player dynamic stochastic nonzero-sum games where
the state transition and observation equations are linear, and the primitive
random variables are Gaussian. Each controller acquires possibly different
dynamic information about the state process and the other controller's past
actions and observations. This leads to a dynamic game of asymmetric
information among the controllers. Building on our earlier work on finite games
with asymmetric information, we devise an algorithm to compute a Nash
equilibrium by using the common information among the controllers. We call such
equilibria common information based Markov perfect equilibria of the game,
which can be viewed as a refinement of Nash equilibrium in games with
asymmetric information. If the players' cost functions are quadratic, then we
show that under certain conditions a unique common information based Markov
perfect equilibrium exists. Furthermore, this equilibrium can be computed by
solving a sequence of linear equations. We also show through an example that
there could be other Nash equilibria in a game of asymmetric information, not
corresponding to common information based Markov perfect equilibria.


title: On the Measurement of Economic Tail Risk

abstract:
  This paper attempts to provide a decision-theoretic foundation for the
measurement of economic tail risk, which is not only closely related to utility
theory but also relevant to statistical model uncertainty. The main result is
that the only risk measures that satisfy a set of economic axioms for the
Choquet expected utility and the statistical property of elicitability (i.e.
there exists an objective function such that minimizing the expected objective
function yields the risk measure) are the mean functional and the median
shortfall, which is the median of tail loss distribution. Elicitability is
important for backtesting. We also extend the result to address model
uncertainty by incorporating multiple scenarios. As an application, we argue
that median shortfall is a better alternative than expected shortfall for
setting capital requirements in Basel Accords.


title:
Generalized Bhattacharyya and Chernoff upper bounds on Bayes error using
  quasi-arithmetic means

abstract:
  Bayesian classification labels observations based on given prior information,
namely class-a priori and class-conditional probabilities. Bayes' risk is the
minimum expected classification cost that is achieved by the Bayes' test, the
optimal decision rule. When no cost incurs for correct classification and unit
cost is charged for misclassification, Bayes' test reduces to the maximum a
posteriori decision rule, and Bayes risk simplifies to Bayes' error, the
probability of error. Since calculating this probability of error is often
intractable, several techniques have been devised to bound it with closed-form
formula, introducing thereby measures of similarity and divergence between
distributions like the Bhattacharyya coefficient and its associated
Bhattacharyya distance. The Bhattacharyya upper bound can further be tightened
using the Chernoff information that relies on the notion of best error
exponent. In this paper, we first express Bayes' risk using the total variation
distance on scaled distributions. We then elucidate and extend the
Bhattacharyya and the Chernoff upper bound mechanisms using generalized
weighted means. We provide as a byproduct novel notions of statistical
divergences and affinity coefficients. We illustrate our technique by deriving
new upper bounds for the univariate Cauchy and the multivariate
$t$-distributions, and show experimentally that those bounds are not too
distant to the computationally intractable Bayes' error.


title:
The Local-Global Principle for Integral Generalized Apollonian Sphere
  Packings

abstract:
  Four mutually tangent spheres form two gaps. In each of these, one can
inscribe in a unique way four mutually tangent spheres such that each one of
these spheres is tangent to exactly three of the original spheres. Repeating
the process gives rise to a generalized Apollonian sphere packing. These
packings have remarkable properties. One of them is the local to global
principle and will be proven in this paper.


title:
Cryptanalysis of Multi-Server Authenticated Key Agreement Scheme Based
  on Trust Computing Using Smart Cards and Biometrics

abstract:
  Advancement in communication technology provides a scalable platform for
various services where a remote user can access the server from anywhere
without moving from its place. It has provided a unique opportunity for online
services, such that the user need not physically present at the service center.
These services adopt authentication and key agreement protocols to ensure
authorized and secure access to resources. Most of the authentication schemes
support single server environment where the user has to register with each
server. If a user wishes to access multiple application servers, he requires to
register with each of the servers. Although multi-server authentication schemes
introduced a scalable platform such that a user can interact with any server
using single registration. Recently, Chuang and Chen proposed an efficient
multi-server authenticated key agreement scheme based on smart cards along with
password and biometrics. This is a lightweight authentication scheme which
requires the computation of only hash function. In this article, we present a
brief review of Chuang and Chen's scheme. We analyze Chuang and Chen's scheme
and identify that their scheme does not resist stolen smart card attack which
causes the user's impersonation attack, server spoofing attack and man-in-the
middle attack. Additionally, we show that their scheme has a weak key agreement
protocol, which does not ensure forward secrecy.


title:
Studies of Radio Galaxies and Starburst Galaxies using Wide-field, High
  Spatial Resolution Radio Imaging

abstract:
  This thesis reports on the application of new wide-field Very Long Baseline
Interferometry (VLBI) imaging techniques using real data for the first time.
These techniques are used to target three specific science areas: (i) a
sub-parsec-scale study of compact radio sources in nearby starburst galaxies,
(ii) a study of jet interactions in active radio galaxies, and (iii) an
unbiased study of the sub-arcsecond, 90 cm sky.


title: Core entropy and biaccessibility of quadratic polynomials

abstract:
  For complex quadratic polynomials, the topology of the Julia set and the
dynamics are understood from another perspective by considering the Hausdorff
dimension of biaccessing angles and the core entropy: the topological entropy
on the Hubbard tree. These quantities are related according to Thurston. Tiozzo
[arXiv:1305.3542] has shown continuity on principal veins of the Mandelbrot set
M . This result is extended to all veins here, and it is shown that continuity
with respect to the external angle theta will imply continuity in the parameter
c . Level sets of the biaccessibility dimension are described, which are
related to renormalization. H\"older asymptotics at rational angles are found,
confirming the H\"older exponent given by Bruin--Schleicher [arXiv:1205.2544].
Partial results towards local maxima at dyadic angles are obtained as well, and
a possible self-similarity of the dimension as a function of the external angle
is suggested.


title:
Analysis of mean cluster size in directed compact percolation near a
  damp wall

abstract:
  We investigate the behaviour of the mean size of directed compact percolation
clusters near a damp wall in the low-density region, where sites in the bulk
are wet (occupied) with probability $p$ while sites on the wall are wet with
probability $p_w$. Methods used to find the exact solution for the dry case
($p_w=0$) and the wet case ($p_w=1$) turn out to be inadequate for the damp
case. Instead we use a series expansion for the $p_w=2p$ case to obtain a
second order inhomogeneous differential equation satisfied by the mean size,
which exhibits a critical exponent $\gamma=2$, in common with the wet wall
result. For the more general case of $p_w=rp$, with $r$ rational, we use a
modular arithmetic method of finding ODEs and obtain a fourth order homogeneous
ODE satisfied by the series. The ODE is expressed exactly in terms of $r$. We
find that in the damp region $0<r<2$ the critical exponent $\gamma^{\rm
damp}=1$, in common with the dry wall result.


title: On the numerical radii of $2\times2$ complex matrices

abstract: The numerical radius of the general $2\times2$ complex matrix is calculated.


title: A Three-Dimensional Voting System in Hong Kong

abstract:
  The voting system in the Legislative Council of Hong Kong (Legco) is
sometimes unicameral and sometimes bicameral, depending on whether the bill is
proposed by the Hong Kong government. Therefore, although without any
representative within Legco, the Hong Kong government has certain degree of
legislative power --- as if there is a virtual representative of the Hong Kong
government within the Legco. By introducing such a virtual representative of
the Hong Kong government, we show that Legco is a three-dimensional voting
system. We also calculate two power indices of the Hong Kong government through
this virtual representative and consider the $C$-dimension and the
$W$-dimension of Legco. Finally, some implications of this Legco model to the
current constitutional reform in Hong Kong will be given.


title:
Spin relaxation of a diffusively moving carrier in a random hyperfine
  field

abstract:
  Relaxation, <Sz(t)>, of the average spin of a carrier in course of hops over
sites hosting random hyperfine fields is studied theoretically. In low
dimensions, d = 1, 2, the decay of average spin with time is non-exponential at
all times. The origin of the effect is that for d = 1, 2 a typical random-walk
trajectory exhibits numerous self-intersections. Multiple visits of the carrier
to the same site accelerates the relaxation since the corresponding partial
rotations of spin during these visits add up. Another consequence of
self-intersections of the random-walk trajectories is that, in all dimensions,
the average, <Sz(t)>, becomes sensitive to a weak magnetic field directed along
z. Our analytical predictions are complemented by the numerical simulations of
<Sz(t)>.


title: Non-K\"ahler Calabi-Yau manifolds

abstract:
  We study the class of compact complex manifolds whose first Chern class
vanishes in the Bott-Chern cohomology. This class includes all manifolds with
torsion canonical bundle, but it is strictly larger. After making some
elementary remarks, we show that a manifold in Fujiki's class C with vanishing
first Bott-Chern class has torsion canonical bundle. We also give some examples
of non-Kahler Calabi-Yau manifolds, and discuss the problem of defining and
constructing canonical metrics on them.


title:
Integrated GaN photonic circuits on silicon (100) for second harmonic
  generation

abstract:
  We demonstrate second order optical nonlinearity in a silicon architecture
through heterogeneous integration of single-crystalline gallium nitride (GaN)
on silicon (100) substrates. By engineering GaN microrings for dual resonance
around 1560 nm and 780 nm, we achieve efficient, tunable second harmonic
generation at 780 nm. The \{chi}(2) nonlinear susceptibility is measured to be
as high as 16 plus minus 7 pm/V. Because GaN has a wideband transparency window
covering ultraviolet, visible and infrared wavelengths, our platform provides a
viable route for the on-chip generation of optical wavelengths in both the far
infrared and near-UV through a combination of \{chi}(2) enabled
sum-/difference-frequency processes.


title: LDPC Codes for Partial-Erasure Channels in Multi-Level Memories

abstract:
  In this paper, we develop a new channel model, which we name the $q$-ary
partial erasure channel (QPEC). QPEC has a $q$-ary input, and its output is
either one symbol or a set of $M$ possible values. This channel mimics
situations when current/voltage levels in measurement channels are only
partially known, due to high read rates or imperfect current/voltage sensing.
Our investigation is concentrated on the performance of low-density
parity-pheck (LDPC) codes when used over this channel, due to their low
decoding complexity with iterative-decoding algorithms. We give the density
evolution equations of this channel, and develop its decoding-threshold
analysis. Part of the analysis shows that finding the exact decoding threshold
efficiently lies upon a solution to an open problem in additive combinatorics.
For this part we give bounds and approximations.


title:
High performance nanophotonic circuits based on partially buried
  horizontal slot waveguides

abstract:
  We present a novel platform to construct high-performance nanophotonic
devices in low refractive index dielectric films at telecoms wavelengths. The
formation of horizontal slots by PECVD deposition of high index amorphous
silicon provides a convenient and low-cost way to tailor nanophotonic devices
to application needs. Low propagation loss of less than 2 dB/cm is obtained
allowing us to fabricate optical resonators with measured high optical quality
factors exceeding 10^5. We design and experimentally demonstrate on-chip
grating couplers to efficiently couple light into integrated circuitry with
coupling loss of 4 dB and optical bandwidth exceeding 110 nm. The entire
on-chip circuitry consisting of input/output couplers, Mach-Zehnder
interferometers with high extinction ratio and ring, racetrack resonators are
designed, fabricated and characterized.


title:
Perturbative $O(\alpha_s)$ corrections to the correlation functions of
  light tetraquark currents

abstract:
  We calculate the next-to-leading order QCD corrections to the perturbative
term in the operator product expansion of the spectral functions of light
tetraquark currents. By using also configuration space methods we keep the
momentum space four-loop calculation to a manageable level. We find that the
next-to-leading order corrections to the perturbative term are large and can
amount to $O(100\%)$. The corrections to the corresponding Borel sum rules,
however, are small since the nonperturbative condensate contributions dominate
the Borel sum rules.


title:
Process Evolution Supported by Rationale: An Empirical Investigation of
  Process Changes

abstract:
  Evolving a software process model without a retrospective and, in
consequence, without an understanding of the process evolution, can lead to
severe problems for the software development organization, e.g., inefficient
performance as a consequence of the arbitrary introduction of changes or
difficulty in demonstrating compliance to a given standard. Capturing
information on the rationale behind changes can provide a means for better
understanding process evolution. This article presents the results of an
exploratory study with the goal of understanding the nature of process changes
in a given context. It presents the most important issues that motivated
process engineers changing important aerospace software process standards
during an industrial project. The study is part of research work intended to
incrementally define a systematic mechanism for process evolution supported by
rationale information.


title:
Clustering in Globally Coupled Oscillators Near a Hopf Bifurcation:
  Theory and Experiments

abstract:
  A theoretical analysis is presented to show the general occurrence of phase
clusters in weakly, globally coupled oscillators close to a Hopf bifurcation.
Through a reductive perturbation method, we derive the amplitude equation with
a higher order correction term valid near a Hopf bifurcation point. This
amplitude equation allows us to calculate analytically the phase coupling
function from given limit-cycle oscillator models. Moreover, using the phase
coupling function, the stability of phase clusters can be analyzed. We
demonstrate our theory with the Brusselator model. Experiments are carried out
to confirm the presence of phase clusters close to Hopf bifurcations with
electrochemical oscillators.


title: First data from DM-Ice17

abstract:
  We report the first analysis of background data from DM-Ice17, a
direct-detection dark matter experiment consisting of 17 kg of NaI(Tl) target
material. It was codeployed with IceCube 2457 m deep in the South Pole glacial
ice in December 2010 and is the first such detector operating in the Southern
Hemisphere. The background rate in the 6.5 - 8.0 keVee region is measured to be
7.9 +/- 0.4 counts/day/keV/kg. This is consistent with the expected background
from the detector assemblies with negligible contributions from the surrounding
ice. The successful deployment and operation of DM-Ice17 establishes the South
Pole ice as a viable location for future underground, low-background
experiments in the Southern Hemisphere. The detector assembly and deployment
are described here, as well as the analysis of the DM-Ice17 backgrounds based
on data from the first two years of operation after commissioning, July 2011 -
June 2013.

categories: astro-ph.IM astro-ph.CO hep-ex physics.ins-det


title: Avalanches and disorder-induced criticality in artificial spin ices

abstract:
  We show that both square and kagome artificial spin ice systems exhibit
disorder-induced nonequilibrium phase transitions, with power law avalanche
distributions at the critical disorder level. The different nature of
geometrical frustration in the two lattices produces distinct types of critical
avalanche behavior. For the square ice, the avalanches involve the propagation
of locally stable domain walls separating the two polarized ground states, and
the scaling collapse agrees with an interface depinning mechanism. In contrast,
avalanches in the fully frustrated kagome ice exhibit pronounced branching
behaviors that resemble those found in directed percolation. The kagome ice
also shows an interesting crossover in the power-law scaling of the avalanches
at low disorder. Our results show that artificial spin ices are ideal systems
in which to study nonequilibrium critical point phenomena.


title:
Valley Contrasting Magnetoluminescence in Monolayer MoS$_{2}$ Quantum
  Hall Systems

abstract:
  The valley dependent optical selection rules in recently discovered monolayer
group-VI transition metal dichalcogenides (TMDs) make possible optical control
of valley polarization, a crucial step towards valleytronic applications.
However, in presence of Landaul level(LL) quantization such selection rules are
taken over by selection rules between the LLs, which are not necessarily valley
contrasting. Using MoS$_{2}$ as an example we show that the spatial
inversion-symmetry breaking results in unusual valley dependent inter-LL
selection rules, which directly locks polarization to valley. We find a
systematic valley splitting for all Landau levels (LLs) in the quantum Hall
regime, whose magnitude is linearly proportional to the magnetic field and in
comparable with the LL spacing. Consequently, unique plateau structures are
found in the optical Hall conductivity, which can be measured by the
magneto-optical Faraday rotations.


title: Competing electronic states in high temperature phase of NaTiO$_2$

abstract:
  First principle density functional theory (DFT) calculations on the high
temperature phase of layered triangular lattice system NaTiO$_2$ have revealed
that there exists a collective electronic state energetically close to the
ground state but with competing transport properties: the latter is metallic
with partially occupied doubly degenerate e$_g^{\prime}$ orbitals whereas the
former is insulating with a$_{1g}$ orbital fully occupied. Significant
occupation of this excited state is possible at non zero temperature either
thermally or thanks to very soft (large amplitude) oxygen vibrations. Possible
explanations of the experimental low conductivity based on competing orbital
transport and of the specific heat jump at a structural transition based on
orbital entropy are discussed.


title:
Maintaining a Large Process Model Aligned with a Process Standard: An
  Industrial Example

abstract:
  An essential characteristic of mature software and system development
organizations is the definition and use of explicit process models. For a
number of reasons, it can be valuable to produce new process models by
tailoring existing process standards (such as the V-Modell XT). Both process
models and standards evolve over time in order to integrate improvements or
adapt the process models to context changes. An important challenge for a
process engineering team is to keep tailored process models aligned over time
with the standards originally used to produce them. This article presents an
approach that supports the alignment of process standards evolving in parallel
to derived process models, using an actual industrial example to illustrate the
problems and potential solutions. We present and discuss the results of a
quantitative analysis done to determine whether a strongly tailored model can
still be aligned with its parent standard and to assess the potential cost of
such an alignment. We close the paper with conclusions and outlook.


title: A strategy to suppress recurrence in grid-based Vlasov solvers

abstract:
  In this paper we propose a strategy to suppress the recurrence effect present
in grid-based Vlasov solvers. This method is formulated by introducing a cutoff
frequency in Fourier space. Since this cutoff only has to be performed after a
number of time steps, the scheme can be implemented efficiently and can
relatively easily be incorporated into existing Vlasov solvers. Furthermore,
the scheme proposed retains the advantage of grid-based methods in that high
accuracy can be achieved. This is due to the fact that in contrast to the
scheme proposed by Abbasi et al. no statistical noise is introduced into the
simulation. We will illustrate the utility of the method proposed by performing
a number of numerical simulations, including the plasma echo phenomenon, using
a discontinuous Galerkin approximation in space and a Strang splitting based
time integration.


title:
Error analysis of nonconforming and mixed FEMs for second-order linear
  non-selfadjoint and indefinite elliptic problems

abstract:
  The state-of-the art proof of a global inf-sup condition on mixed finite
element schemes does not allow for an analysis of truly indefinite,
second-order linear elliptic PDEs. This paper, therefore, first analyses a
nonconforming finite element discretization which converges owing to some a
priori $L^2$ error estimates even for reduced regularity on non-convex
polygonal domains. An equivalence result of that nonconforming finite element
scheme to the mixed finite element method (MFEM) leads to the well-posedness of
the discrete solution and to a priori error estimates for the MFEM. The
explicit residual-based a posteriori error analysis allows some reliable and
efficient error control and motivates some adaptive discretization which
improves the empirical convergence rates in three computational benchmarks.


title:
Superconducting properties of BiS2 based superconductor NdO1-xFxBiS2
  (x=0 to 0.9)

abstract:
  We report the phase diagram of NdO1-xFxBiS2 (x=0.1, 0.3, 0.5, 0.7, 0.9)
compound. The samples synthesized by the vacuum encapsulation technique are
crystallized in a tetragonal P4/nmm space group. The superconductivity of all
samples is confirmed by DC magnetic susceptibility and electrical transport
measurements. The maximum Tc of 5.25K is seen for x = 0.7 sample. The upper
critical field is calculated from magneto transport measurements. The Thermal
activated flux flow - TAFF studies are also carried out. Hall measurements show
that electrons are the dominating charge carriers in these systems.


title: Extension of Chern-Simons forms

abstract:
  We investigate metric independent, gauge invariant and closed forms in the
generalized YM theory. These forms are polynomial on the corresponding fields
strength tensors - curvature forms and are analogous to the Pontryagin-Chern
densities in the YM gauge theory. The corresponding secondary characteristic
classes have been expressed in integral form in analogy with the Chern-Simons
form. Because they are not unique, the secondary forms can be dramatically
simplified by the addition of properly chosen differentials of
one-step-lower-order forms. Their gauge variation can also be found yielding
the potential anomalies in the gauge field theory.


title: Definable henselian valuation rings

abstract:
  We give model theoretic criteria for $\exists \forall$ and $\forall \exists$-
formulas in the ring language to define uniformly the valuation rings
$\mathcal{O}$ of models $(K, \mathcal{O})$ of an elementary theory $\Sigma$ of
henselian valued fields. As one of the applications we obtain the existence of
an $\exists \forall$-formula defining uniformly the valuation rings
$\mathcal{O}$ of valued henselian fields $(K, \mathcal{O})$ whose residue class
field $k$ is finite, pseudo-finite, or hilbertian. We also obtain $\forall
\exists$-formulas $\varphi_2$ and $\varphi_4$ such that $\varphi_2$ defines
uniformly $k[[t]]$ in $k((t))$ whenever $k$ is finite or the function field of
a real or complex curve, and $\varphi_4$ does the job if $k$ is any number
field.


title: Studies of low-energy effective actions in supersymmetric field theories

abstract:
  This thesis examines low-energy effective actions of supersymmetric quantum
field theories. These actions contain information about the low-energy field
content and dynamics of quantum field theories and are essential for
understanding their phenomenological and theoretical properties.
  In chapters 2 to 5, the covariant background field method is used to
investigate quantum corrections to sectors of a variety of supersymmetric field
theories at 1 and 2 loops. We start by looking at the background field
quantisation of a general N=1 super-Yang-Mills theory, rederiving the
well-known 1 loop finiteness conditions. This is followed by a reexamination of
the effective potential of the Wess-Zumino model, focusing on a derivation of
the full auxiliary fields' potential. Next, the 2 loop Euler-Heisenberg
effective action is constructed for N=1 supersymmetric quantum electrodynamics;
its renormalisation properties and self-dual limit are studied. The final
action studied is the 2 loop Kahler potential for beta-deformed N=4
super-Yang-Mills. This sector is purely a product of the deformation and its
finiteness is demonstrated in a general background before examining two special
cases.
  Chapter 6 studies spontaneously broken supersymmetry and the pure Goldstino
action. A general approach to constructing explicit field redefinitions is used
to relate all known models of the Goldstino and to study their nonlinear
supersymmetries. This approach is also used to construct the most general pure
Goldstino action and to examine its supersymmetry transformations. Finally, a
new embedding of the Goldstino into a complex linear superfield is presented.
Its interactions to matter and gravity are examined and compared to existing
Goldstino superfield constructions.


title: Inflation and topological phase transition driven by exotic smoothness

abstract:
  In this paper we will discuss a model which describes the cause of inflation
by a topological transition. The guiding principle is the choice of an exotic
smoothness structure for the space-time. Here we consider a space-time with
topology $S^{3}\times\mathbb{R}$. In case of an exotic $S^{3}\times\mathbb{R}$,
there is a change in the spatial topology from a 3-sphere to a homology
3-sphere which can carry a hyperbolic structure. From the physical point of
view, we will discuss the path integral for the Einstein-Hilbert action with
respect to a decomposition of the space-time. The inclusion of the boundary
terms produces fermionic contributions to the partition function. The
expectation value of an area (with respect to some surface) shows an
exponential increase, i.e. we obtain inflationary behavior. We will calculate
the amount of this increase to be a topological invariant. Then we will
describe this transition by an effective model, the Starobinski or $R^{2}$
model which is consistent with the current measurement of the Planck satellite.
The spectral index and other observables are also calculated. Finally we obtain
a realistic cosmological constant.


title:
Gravitational sources induced by exotic smoothness and fermions as knot
  complements

abstract:
  In this paper we will discuss Brans conjecture that exotic smoothness serves
as an additional gravitational source naturally arising from the handlebody
construction of the exotic $\mathbb{R}^{4}$. We will consider the two possible
classes, the large and the small exotic $\mathbb{R}^{4}$. Then we calculate the
Einstein-Hilbert action for both exotic $\mathbb{R}^{4}$ to show the apearance
of spinor fields. Then we discuss the physical properties of these spinor
fields to relate them to fermions. Finally we identify the corresponding
3-manifolds as knot complements of hyperbolic knots, i.e. the knot complements
are hyperbolic 3-manifolds with finite volume. With the help of this result we
confirm the Brans conjecture for both kinds of exotic $\mathbb{R}^{4}$.


title: Binomial edge ideals with pure resolutions

abstract:
  We characterize all graphs whose binomial edge ideals have pure resolutions.
Moreover, we introduce a new switching of graphs which does not change some
algebraic invariants of graphs, and using this, we study the linear strand of
the binomial edge ideals for some classes of graphs. Also, we pose a conjecture
on the linear strand of such ideals for every graph.


title:
Horizontal flow fields observed in Hinode G-band images IV. Statistical
  properties of the dynamical environment around pores

abstract:
  The extensive database of high-resolution G-band images observed with the
Hinode/SOT is a unique resource to derive statistical properties of pores using
advanced digital image processing techniques. The study is based on two data
sets: (1) Photometric and morphological properties inferred from single G-band
images cover almost seven years from 2006 October 25 to 2013 August 31. (2)
Horizontal flow fields have been derived from 356 one-hour sequences of G-band
images using LCT for a shorter period of time from 2006 November 3 to 2008
January 6 comprising 13 active regions.
  A total of 7643/2863 (single/time-averaged) pores builds the foundation of
the statistical analysis. Pores are preferentially observed at low latitudes in
the southern hemisphere during the deep minimum of solar cycle No. 23. This
imbalance reverses during the rise of cycle No. 24, when the pores migrate from
high to low latitudes. Pores are rarely encountered in quiet-Sun G-band images,
and only about 10% of pores exists in isolation. In general, pores do not
exhibit a circular shape. Typical aspect ratios of the semi-major and -minor
axes are 3:2 when ellipses are fitted to pores. Smaller pores (more than
two-thirds are smaller than 5~Mm^2) tend to be more circular, and their
boundaries are less corrugated. Both area and perimeter length of pores obey
log-normal frequency distributions. The frequency distribution of the intensity
can be reproduced by two Gaussians representing dark and bright components.
Bright features resembling umbral dots and even light-bridges cover about 20%
of the pore's area. Averaged radial profiles show a peak of the intensity at
normalized radius R_N = r /R_pore = 2.1, followed by maxima of the divergence
at R_N= 2.3 and the radial component of the horizontal velocity at R_N= 4.6.
The divergence is negative within pores.


title:
Observational Tests of Nonlocal Gravity: Galaxy Rotation Curves and
  Clusters of Galaxies

abstract:
  A classical nonlocal generalization of Einstein's theory of gravitation has
recently been developed via the introduction of a scalar causal "constitutive"
kernel that must ultimately be determined from observational data. It turns out
that the nonlocal aspect of gravity in this theory can simulate dark matter;
indeed, in the Newtonian regime of nonlocal gravity, we recover the
phenomenological Tohline-Kuhn approach to modified gravity. A simple
generalization of the Kuhn kernel in the context of nonlocal general relativity
leads to a two-parameter modified Newtonian force law that involves an
additional repulsive Yukawa-type interaction. We determine the parameters of
our nonlocal kernel by comparing the predictions of the theory with
observational data regarding the rotation curves of spiral galaxies. The
best-fitting stellar mass-to-light ratio turns out to be in agreement with
astrophysical models; moreover, our results are consistent with the
Tully-Fisher relation for spiral galaxies. Light deflection in nonlocal gravity
is consistent with general relativity at Solar System scales, while beyond
galactic scales an enhanced deflection angle is predicted that is compatible
with lensing by the effective "dark matter". Furthermore, we extend our results
to the internal dynamics of rich clusters of galaxies and show that the
dynamical mass of the cluster obtained from nonlocal gravity is consistent with
the measured baryonic mass.


title:
Taylor expansion of luminosity distance in Szekeres cosmological models:
  Effects of local structures evolution on cosmographic parameters

abstract:
  We consider the Goode-Wainwright representation of the Szekeres cosmological
models and calculate the Taylor expansion of the luminosity distance in order
to study the effects of the inhomogeneities on cosmographic parameters. Without
making a particular choice for the arbitrary functions defining the metric, we
Taylor expand up to the second order in redshift for Family I and up to the
third order for Family II Szekeres metrics under the hypotesis, based on
observation, that local structure formation is over. In a conservative fashion,
we also allow for the existence of a non null cosmological constant.


title: Process Model Difference Analysis for Supporting Process Evolution

abstract:
  Software development processes are subject to variations in time and space,
variations that can originate from learning effects, differences in application
domains, or a number of other causes. Identifying and analyzing such
differences is crucial for a variety of process activities, like defining and
evolving process standards, or analyzing the compliance of process models to
existing standards, among others. In this paper, we show why appropriately
identifying, describing, and visualizing differences between process models in
order to support such activities is a highly challenging task. We present
scenarios that motivate the need for process model difference analysis, and
describe the conceptual and technical challenges arising from them. In
addition, we sketch an initial tool-based approach implementing difference
analysis, and contrast it with similar existing approaches. The results from
this paper constitute the requirements for our ongoing development effort,
whose objectives we also describe briefly.


title: Wide-field variability survey of the globular cluster NGC 4833

abstract:
  We present preliminary results of the variability survey in the field of the
glo bular cluster NGC 4833. We observed all 34 variable stars known in the
cluster. In add ition, we have found two new SX Phoenicis stars, one new RR
Lyrae star, twelve new ecli psing systems mostly of the W Ursae Majoris type,
nine new variable red giants, and ten new field-stars showing irregular
variations. Properties of RR Lyrae stars indicate that NGC 4833 is an
Oosterhoff's type II globular cluster.


title:
Proton-driven plasma wakefield acceleration: a path to the future of
  high-energy particle physics

abstract:
  New acceleration technology is mandatory for the future elucidation of
fundamental particles and their interactions. A promising approach is to
exploit the properties of plasmas. Past research has focused on creating
large-amplitude plasma waves by injecting an intense laser pulse or an electron
bunch into the plasma. However, the maximum energy gain of electrons
accelerated in a single plasma stage is limited by the energy of the driver.
Proton bunches are the most promising drivers of wakefields to accelerate
electrons to the TeV energy scale in a single stage. An experimental program at
CERN -- the AWAKE experiment -- has been launched to study in detail the
important physical processes and to demonstrate the power of proton-driven
plasma wakefield acceleration. Here we review the physical principles and some
experimental considerations for a future proton-driven plasma wakefield
accelerator.


title:
Investigating the Dynamics and Density Evolution of Returning Plasma
  Blobs from the 2011 June 7 Eruption

abstract:
  This work examines infalling matter following an enormous Coronal Mass
Ejection (CME) on 2011 June 7. The material formed discrete concentrations, or
blobs, in the corona and fell back to the surface, appearing as dark clouds
against the bright corona. In this work we examined the density and dynamic
evolution of these blobs in order to formally assess the intriguing morphology
displayed throughout their descent. The blobs were studied in five wavelengths
(94, 131, 171, 193 and 211 \AA) using the Solar Dynamics Observatory
Atmospheric Imaging Assembly (SDO/AIA), comparing background emission to
attenuated emission as a function of wavelength to calculate column densities
across the descent of four separate blobs. We found the material to have a
column density of hydrogen of approximately 2 $\times$ 10$^{19}$ cm$^{-2}$,
which is comparable with typical pre-eruption filament column densities.
Repeated splitting of the returning material is seen in a manner consistent
with the Rayleigh-Taylor instability. Furthermore, the observed distribution of
density and its evolution are also a signature of this instability. By
approximating the three-dimensional geometry (with data from STEREO-A),
volumetric densities were found to be approximately 2 $\times$ 10$^{-14}$ g
cm$^{-3}$, and this, along with observed dominant length-scales of the
instability, was used to infer a magnetic field of the order 1 G associated
with the descending blobs.


title:
Conformation characters of gel sheets with rotational symmetry: the role
  of boundary

abstract:
  In this paper, we systemically study the conformation characters of
rotational symmetric gel sheets with free boundary and investigate the role of
boundary on the equilibrium conformation. In gel sheet the boundary provides a
residual strain which leads to re-distribution of stress and impacts the shape
of equilibrium conformation accordingly. For sheet with boundary, the in-plane
stretching energy is far larger than the bending energy in some cases. It is
intrinsic different from closed membrane. In gel sheets, the boundary doesn't
only quantitatively amend to the elastic energy. The residual strain on
boundary cooperates with bending and stretching to determine the equilibrium
conformation rather than just the last two factors. Furthermore, on the
boundary of gel sheet, there is an additional energy induced by boundary line
tension $\gamma $. If $\gamma =0$, there is $10\%$ difference of elastic energy
from the experimental result. Finally, we discuss the effects of such line
tension $\gamma $ and propose a way to measure it by the border radius. It
redounds to study the physical origination of $\gamma $.


title:
Null eikonal helices and Null eikonal slant helices in the 4-dimensional
  Lorentzian manifold

abstract:
  In this paper, we define the notion of eikonal helix and eikonal slant helix
for null curves in the 4-dimensional Lorentzian manifold M 1 4 and give a
characterization for the null curve to be the null eikonal helix. Moreover, we
indicate an important relation between the null eikonal helix and null eikonal
slant helix and find the axis of the null eikonal helix. We obtain some
relationships between the curvatures of these curves.


title: Measures of Correlation for Multiple Variables

abstract:
  Multivariate correlation analysis plays an important role in various fields
such as statistics, economics, and big data analytics. In this paper, we
propose a pair of measures, the unsigned correlation coefficient (UCC) and the
unsigned incorrelation coefficient (UIC), to measure the strength of
correlation and incorrelation (lack of correlation) among multiple variables.
The absolute value of Pearson's correlation coefficient is a special case of
UCC for two variables. Some important properties of UCC and UIC show that the
proposed UCC and UIC are a pair of effective measures for multivariate
correlation. We also take the unsigned tri-variate correlation coefficient as
an example to visually display the effectiveness of the proposed UCC, and the
geometrical explanation of UIC is also discussed. All the properties and the
figures of UCC and UIC show that the proposed UCC and UIC are the general
measures of correlation for multiple variables.


title: $q$-Virasoro algebra and vertex algebras

abstract:
  In this paper, we study a certain deformation $D$ of the Virasoro algebra
that was introduced and called $q$-Virasoro algebra by Nigro,in the context of
vertex algebras. Among the main results, we prove that for any complex number
$\ell$, the category of restricted $D$-modules of level $\ell$ is canonically
isomorphic to the category of quasi modules for a certain vertex algebra of
affine type. We also prove that the category of restricted $D$-modules of level
$\ell$ is canonically isomorphic to the category of $\mathbb{Z}$-equivariant
$\phi$-coordinated quasi modules for the same vertex algebra. In the process,
we introduce and employ a certain infinite dimensional Lie algebra which is
defined in terms of generators and relations and then identified explicitly
with a subalgebra of $\mathfrak{gl}_{\infty}$.


title:
Approximated Lax Pairs for the Reduced Order Integration of Nonlinear
  Evolution Equations

abstract:
  A reduced-order model algorithm, called ALP, is proposed to solve nonlinear
evolution partial differential equations. It is based on approximations of
generalized Lax pairs. Contrary to other reduced-order methods, like Proper
Orthogonal Decomposition, the basis on which the solution is searched for
evolves in time according to a dynamics specific to the problem. It is
therefore well-suited to solving problems with progressive front or wave
propagation. Another difference with other reduced-order methods is that it is
not based on an off-line / on-line strategy. Numerical examples are shown for
the linear advection, KdV and FKPP equations, in one and two dimensions.


title: A Panchromatic Survey of Post-starburst Mergers: searching for feedback

abstract:
  We consider the morphology, stellar populations, structure and AGN activity
of 10 post-starburst (K+A) galaxies with HST observations, full spectral
coverage in the optical, spectral energy distributions from 0.2 to 160 $\mu$m,
X-ray and radio data. Our results show that the PSG phenomenon is related to
mergers and interactions, and that star formation was likely triggered during
close passes prior to final coalescence. We performed a detailed qualitative
analysis of the observed light distribution, including low-surface brightness
tidal features and color profiles, in high-resolution multi-band imaging with
HST. We find evidence that star formation was centrally concentrated and that
quenching took place from the inside-out, consistent with the occurrence of a
feedback episode. Most of our PSGs contain massive bulges and therefore should
host supermassive black holes. We search for AGN activity in spectra (line
ratios), optical variability, X-ray emission at 0.5--7.0 KeV and radio emission
at 20cm: all four lines of evidence show there is no active AGN accreting at
more than 0.1\% of the Eddington luminosity. We conclude that mergers may be a
necessary, but not a sufficient condition, for AGN activity and that they are
not likely to be important in our objects. If PSGs are good test cases for
quenching and evolution to the red sequence, AGNs may play a smaller role than
expected.


title: Approximate Capacities of Two-Dimensional Codes by Spatial Mixing

abstract:
  We apply several state-of-the-art techniques developed in recent advances of
counting algorithms and statistical physics to study the spatial mixing
property of the two-dimensional codes arising from local hard (independent set)
constraints, including: hard-square, hard-hexagon, read/write isolated memory
(RWIM), and non-attacking kings (NAK). For these constraints, the strong
spatial mixing would imply the existence of polynomial-time approximation
scheme (PTAS) for computing the capacity. It was previously known for the
hard-square constraint the existence of strong spatial mixing and PTAS. We show
the existence of strong spatial mixing for hard-hexagon and RWIM constraints by
establishing the strong spatial mixing along self-avoiding walks, and
consequently we give PTAS for computing the capacities of these codes. We also
show that for the NAK constraint, the strong spatial mixing does not hold along
self-avoiding walks.


title:
Fast pseudolikelihood maximization for direct-coupling analysis of
  protein structure from many homologous amino-acid sequences

abstract:
  Direct-Coupling Analysis is a group of methods to harvest information about
coevolving residues in a protein family by learning a generative model in an
exponential family from data. In protein families of realistic size, this
learning can only be done approximately, and there is a trade-off between
inference precision and computational speed. We here show that an earlier
introduced $l_2$-regularized pseudolikelihood maximization method called plmDCA
can be modified as to be easily parallelizable, as well as inherently faster on
a single processor, at negligible difference in accuracy. We test the new
incarnation of the method on 148 protein families from the Protein Families
database (PFAM), one of the largest tests of this class of algorithms to date.


title: The weighted log canonical threshold

abstract:
  In this note, we show how to apply the original $L^2$-extension theorem of
Ohsawa and Takegoshi to the standard basis of a multiplier ideal sheaf
associated with a plurisubharmonic function. In this way, we are able to
reprove the strong openness conjecture and to obtain an effective version of
the semicontinuity theorem for weighted log canonical thresholds.


title:
On Low-Complexity Full-diversity Detection In Multi-User MIMO
  Multiple-Access Channels

abstract:
  Multiple-input multiple-output (MIMO) techniques are becoming commonplace in
recent wireless communication standards. This added dimension (i.e., space) can
be efficiently used to mitigate the interference in the multi-user MIMO
context. In this paper, we focus on the uplink of a MIMO multiple access
channel (MAC) where perfect channel state information (CSI) is only available
at the destination. We provide a new set of sufficient conditions for a wide
range of space-time block codes (STBC)s to achieve full-diversity under
\emph{partial interference cancellation group decoding} (PICGD) with or without
successive interference cancellation (SIC) for completely blind users. Explicit
interference cancellation (IC) schemes for two and three users are then
provided and shown to satisfy the derived full-diversity criteria. Besides the
complexity reduction due to the fact that the proposed IC schemes enable
separate decoding of distinct users without sacrificing the diversity gain,
further reduction of the decoding complexity may be obtained. In fact, thanks
to the structure of the proposed schemes, the real and imaginary parts of each
user's symbols may be decoupled without any loss of performance. Finally, our
theoretical claims are corroborated by simulation results and the new IC scheme
for two-user MIMO MAC is shown to outperform the recently proposed two-user IC
scheme especially for high spectral efficiency while requiring significantly
less decoding complexity.


title:
Transverse Momentum Distributions in proton - proton Collisions at LHC
  Energies and Tsallis Thermodynamics

abstract:
  A detailed study of the transverse momentum distributions of charged
particles produced in proton - proton collisions at LHC energies is presented.
This is done using a thermodynamically consistent form of the Tsallis
distribution. All variables used are thermodynamical and in particular, the
temperature $T$ follows from the standard thermodynamic definition as being the
derivative of the energy with respect to the (Tsallis) entropy. The momentum
distribution of the final state particles obtained describe the transverse
momentum distributions very well. The values of the parameters are determined
from measurements by the ALICE, ATLAS and CMS collaborations and are discussed
in detail. In particular, the Tsallis parameter, $q$ is found with consistent
values for all the transverse momentum distributions despite large differences
in kinematic regions and shows a slight increase with beam energy, reaching a
value of 1.15 at 7 TeV. It is concluded that the hadronic system created in
high-energy p - p collisions can be seen as obeying Tsallis thermodynamics.


title:
Computation of Minimal Homogeneous Generating Sets and Minimal Standard
  Bases for Ideals of Free Algebras

abstract:
  Let $\KX =K\langle X_1,\ldots ,X_n\rangle$ be the free algebra generated by
$X=\{ X_1,\ldots ,X_n\}$ over a field $K$. It is shown that with respect to any
weighted $\mathbb{N}$-gradation attached to $\KX$, minimal homogeneous
generating sets for finitely generated graded (two-sided) ideals of $\KX$ can
be algorithmically computed, and that if an ungraded (two-sided) ideal $I$ of
$\KX$ has a finite Gr\"obner basis $\G$ with respect to a graded monomial
ordering on $\KX$, then a minimal standard basis for $I$ can be computed via
computing a minimal homogeneous generating set of the associated graded ideal
$\langle\LH (I)\rangle$.


title:
B(E2) strength ratio of one-phonon 2+ states of 94Zr from electron
  scattering at low momentum transfer

abstract:
  Background: The B(E2) transition strength to the 2+_2 state in 94Zr was
initially reported to be larger by a factor of 1.63 than the one to the 2+_1
state from lifetime measurements with the Doppler-shift attenuation method
(DSAM) using the (n,n'gamma) reaction [E. Elhami et al., Phys. Rev. C 75,
011301(R) (2007)]. This surprising behavior was recently revised in a new
measurement by the same group using the same experimental technique leading to
a ratio below unity as expected in vibrational nuclei. Purpose: The goal is an
independent determination of the ratio of B(E2) strengths for the transitions
to the 2+_(1,2) states of 94Zr with inelastic electron scattering. Method: The
relative population of the 2+_(1,2) states in (e,e') reactions was measured at
the SDALINAC in a momentum transfer range q = 0.17 - 0.51 fm^(-1) and analyzed
in plane-wave Born approximation with the method described in A. Scheikh Obeid
et al., Phys. Rev. C 87, 014337 (2013). Results: The extracted B(E2) strength
ratio of 0.789(43) between the excitation of the 2+_1 and 2+_2 states of 94Zr
is consistent with but more precise than the latest (n,n'gamma) experiment.
Using the B(E2) transition strength to the first excited state from the
literature a value of 3.9(9) W.u. is deduced for the B(E2; 2+_2 -> 0+_1)
transition. Conclusions: The electron scattering result independently confirms
the latest interpretation of the different (n,n'gamma) results for the
transition to the 2+_2 state in 94Zr.


title:
The far-zone interatomic Casimir-Polder potential between two
  ground-state atoms outside a Schwarzschild black hole

abstract:
  Based on the idea that the vacuum fluctuations of electromagnetic fields can
induce instantaneous correlated dipoles, we study the far-zone Casimir-Polder
potential between two atoms in the Boulware, Unruh and Hartle-Hawking vacua
outside a Schwarzschild black hole. We show that, at spatial infinity, the
Casimir-Polder potential in the Boulware vacuum is similar to that in the
Minkowski vacuum in flat spacetime with a behavior of $R^{-7}$, so is in the
Unruh vacuum as a result of the backscattering of the Hawking radiation from
the black hole off the spacetime curvature. However, the interatomic
Casimir-Polder potential in the Hartle-Hawking vacuum behaves like that in a
thermal bath at the Hawking temperature. In the region near the event horizon
of the black hole, the modifications caused by the space-time curvature make
the interatomic Casimir-Polder potential smaller in all three vacuum states.


title: The theory of prime ends and spatial mappings

abstract:
  It is given a canonical representation of prime ends in regular spatial
domains and, on this basis, it is studied the boundary behavior of the
so-called lower Q-homeomorphisms that are the natural generalization of the
quasiconformal mappings. In particular, it is found a series of effective
conditions on the function Q(x) for a homeomorphic extension of the given
mappings to the boundary by prime ends in domains with regular boundaries. The
developed theory is applied, in particular, to mappings of the classes of
Sobolev and Orlicz-Sobolev and also to finitely bi-Lipschitz mappings that a
far-reaching extension of the well--known classes of isometric and
quasiisometric mappings.


title: Termination of oblivious chase is undecidable

abstract:
  We show that all--instances termination of chase is undecidable. More
precisely, there is no algorithm deciding, for a given set $\cal T$ consisting
of Tuple Generating Dependencies (a.k.a. Datalog$^\exists$ program), whether
the $\cal T$-chase on $D$ will terminate for every finite database instance
$D$. Our method applies to Oblivious Chase, Semi-Oblivious Chase and -- after a
slight modification -- also for Standard Chase. This means that we give a
(negative) solution to the all--instances termination problem for all version
of chase that are usually considered.
  The arity we need for our undecidability proof is three. We also show that
the problem is EXPSPACE-hard for binary signatures, but decidability for this
case is left open.
  Both the proofs -- for ternary and binary signatures -- are easy. Once you
know them.


title:
Observability of Charged Higgs through Triple or Double Higgs Production
  in a General Two Higgs Doublet Model at an e+e- Linear Collider

abstract:
  In this paper the triple Higgs production in a general two Higgs doublet
model (2HDM) is studied. The production process is e+e- -> H+H-H0 followed by
the charged Higgs decay to a pair of tau nu and the neutral Higgs decay to bb.
The alternative process H+W-H0 is also included as a source of charged Higgs
signal in the analysis. The focus is on a future e+e- linear collider operating
at sqrt(s) = 1.5 TeV. The final state under consideration (tau tau bb ETmiss)
is suitable for electroweak background rejection using the b-tagging tools. It
is shown that although the signal cross section is small, with a reasonable
background suppression, high signal significance values are achievable at an
integrated luminosity 500 fb-1 depending on the charged Higgs mass, tanbeta and
the CP-odd neutral Higgs mass. Finally results are quoted in terms of the
signal significance for charged Higgs in the mass range 170 < mH+ < 400 GeV.


title:
Influence of finite size of molecules on spectrum of fully polarized
  dipolar BECs: Generalization of Bogoliubov's spectrum

abstract:
  We discuss complete theory of point-like particles in fully polarized BECs
describing difference in behaviour of electrically- and magnetically polarized
BECs. Next we present generalization of this theory on finite size particles to
include contribution of size of real molecules on dynamical properties of
dipolar BECs. As an application of obtained equation we calculate spectrum of
linear collective excitations getting generalization of the Bogoliubov's
spectrum. We show absence of roton instability due to positivity of
polarization contribution in the excitation spectrum. We found that new type of
instabilities appears in small wave length limit due to finite size of
molecules.


title:
Simulation of hitting times for Bessel processes with non integer
  dimension

abstract:
  In this paper we pursue and complete the study of the simulation of the
hitting time of some given boundaries for Bessel processes. These problems are
of great interest in many application fields as finance and neurosciences. In a
previous work, the authors introduced a new method for the simulation of
hitting times for Bessel processes with integer dimension. The method was based
mainly on the explicit formula for the distribution of the hitting time and on
the connexion between the Bessel process and the Euclidean norm of the Brownian
motion. This method does not apply anymore for a non integer dimension. In this
paper we consider the simulation of the hitting time of Bessel processes with
non integer dimension and provide a new algorithm by using the additivity
property of the laws of squared Bessel processes. We split each simulation step
in two parts: one is using the integer dimension case and the other one
considers hitting time of a Bessel process starting from zero.


title: Managing Congestion Control in Mobile AD-HOC Network Using Mobile Agents

abstract:
  In mobile adhoc networks, congestion occurs with limited resources. The
standard TCP congestion control mechanism is not able to handle the special
properties of a shared wireless channel. TCP congestion control works very well
on the Internet. But mobile adhoc networks exhibit some unique properties that
greatly affect the design of appropriate protocols and protocol stacks in
general, and of congestion control mechanism in particular. As it turned out,
the vastly differing environment in a mobile adhoc network is highly
problematic for standard TCP. Many approaches have been proposed to overcome
these difficulties. Mobile agent based congestion control Technique is proposed
to avoid congestion in adhoc network. When mobile agent travels through the
network, it can select a less-loaded neighbor node as its next hop and update
the routing table according to the node congestion status. With the aid of
mobile agents, the nodes can get the dynamic network topology in time. In this
paper, a mobile agent based congestion control mechanism is presented.


title:
The jet and arc molecular clouds toward Westerlund 2, RCW 49, and HESS
  J1023-575; 12CO and 13CO (J=2-1 and J=1-0) observations with NANTEN2 and
  Mopra Telescope

abstract:
  We have made new CO observations of two molecular clouds, which we call "jet"
and "arc" clouds, toward the stellar cluster Westerlund 2 and the TeV gamma-ray
source HESS J1023-575. The jet cloud shows a linear structure from the position
of Westerlund 2 on the east. In addition, we have found a new counter jet cloud
on the west. The arc cloud shows a crescent shape in the west of HESS
J1023-575. A sign of star formation is found at the edge of the jet cloud and
gives a constraint on the age of the jet cloud to be ~Myrs. An analysis with
the multi CO transitions gives temperature as high as 20 K in a few places of
the jet cloud, suggesting that some additional heating may be operating
locally. The new TeV gamma-ray images by H.E.S.S. correspond to the jet and arc
clouds spatially better than the giant molecular clouds associated with
Westerlund 2. We suggest that the jet and arc clouds are not physically linked
with Westerlund 2 but are located at a greater distance around 7.5 kpc. A
microquasar with long-term activity may be able to offer a possible engine to
form the jet and arc clouds and to produce the TeV gamma-rays, although none of
the known microquasars have a Myr age or steady TeV gamma-rays. Alternatively,
an anisotropic supernova explosion which occurred ~Myr ago may be able to form
the jet and arc clouds, whereas the TeV gamma-ray emission requires a
microquasar formed after the explosion.


title: Scalar field inflation and Shan-Chen fluid models

abstract:
  A scalar field equivalent to a non-ideal "dark energy fluid" obeying a
Shan-Chen-like equation of state is used as the background source of a flat
Friedmann-Robertson-Walker cosmological spacetime to describe the inflationary
epoch of our universe. Within the slow-roll approximation, a number of
interesting features are presented, including the possibility to fulfill
current observational constraints as well as a graceful exit mechanism from the
inflationary epoch.


title:
Gradient estimates for semilinear elliptic systems and other related
  results

abstract:
  A periodic connection is constructed for a double well potential defined in
the plane. This solution violates Modica's estimate as well as the
corresponding Liouville Theorem for general phase transition potentials.
Gradient estimates are also established for several kinds of elliptic systems.
They allow us to prove in some particular cases the Liouville Theorem. Finally,
we give an alternative form of the stress-energy tensor for solutions defined
in planar domains. As an application, we deduce a (strong) monotonicity
formula.


title: An Evolutionary Approach towards Clustering Airborne Laser Scanning Data

abstract:
  In land surveying, the generation of maps was greatly simplified with the
introduction of orthophotos and at a later stage with airborne LiDAR laser
scanning systems. While the original purpose of LiDAR systems was to determine
the altitude of ground elevations, newer full wave systems provide additional
information that can be used on classifying the type of ground cover and the
generation of maps. The LiDAR resulting point clouds are huge, multidimensional
data sets that need to be grouped in classes of ground cover. We propose a
genetic algorithm that aids in classifying these data sets and thus make them
usable for map generation. A key feature are tailor-made genetic operators and
fitness functions for the subject. The algorithm is compared to a traditional
k-means clustering.


title: On the influence of the seed graph in the preferential attachment model

abstract:
  We study the influence of the seed graph in the preferential attachment
model, focusing on the case of trees. We first show that the seed has no effect
from a weak local limit point of view. On the other hand, we conjecture that
different seeds lead to different distributions of limiting trees from a total
variation point of view. We take a first step in proving this conjecture by
showing that seeds with different degree profiles lead to different limiting
distributions for the (appropriately normalized) maximum degree, implying that
such seeds lead to different (in total variation) limiting trees.


title:
Derivatives with respect to the order of the Bessel function of the
  first kind

abstract:
  An explicit expression of the k-th derivative of the Bessel function
$J_\nu(z)$, with respect to its order $\nu$, is given. Particularizations for
the cases of positive or negative $\nu$ are considered.


title:
A characterization of hypergraphs that achieve equality in the
  Chv\'{a}tal-McDiarmid Theorem

abstract:
  For $k \ge 2$, let $H$ be a $k$-uniform hypergraph on $n$ vertices and $m$
edges. The transversal number $\tau(H)$ of $H$ is the minimum number of
vertices that intersect every edge. Chv\'{a}tal and McDiarmid [Combinatorica 12
(1992), 19--26] proved that $\tau(H)\le ( n + \left\lfloor \frac k2
\right\rfloor m )/ ( \left\lfloor \frac{3k}2 \right\rfloor )$. When $k = 3$,
the connected hypergraphs that achieve equality in the Chv\'{a}tal-McDiarmid
Theorem were characterized by Henning and Yeo [J. Graph Theory 59 (2008),
326--348]. In this paper, we characterize the connected hypergraphs that
achieve equality in the Chv\'{a}tal-McDiarmid Theorem for $k = 2$ and for all
$k \ge 4$.


title:
ExoMol line lists IV: The rotation-vibration spectrum of methane up to
  1500 K

abstract:
  A new hot line list is calculated for $^{12}$CH$_4$ in its ground electronic
state. This line list, called 10to10, contains 9.8 billion transitions and
should be complete for temperatures up to 1500 K. It covers the wavelengths
longer than 1 $\mu$m and includes all transitions to upper states with energies
below $hc \cdot 18\,000$ cm$^{-1}$ and rotational excitation up to $J=39$. The
line list is computed using the eigenvalues and eigenfunctions of CH$_4$
obtained by variational solution of the Schr\"{o}dinger equation for the
rotation-vibration motion of nuclei employing program TROVE. An ab initio
dipole moment surface and a new 'spectroscopic' potential energy surface are
used. Detailed comparisons with other available sources of methane transitions
including HITRAN, experimental compilations and other theoretical line lists
show that these sources lack transitions both higher temperatures and near
infrared wavelengths. This line list is suitable for modelling atmospheres of
cool stars and exoplanets. It is available from the CDS database as well as at
www.exomol.com.


title: Intrinsic volumes of set of singular matrices

abstract:
  We explicitly compute the intrinsic volume of the set of real (and real
symmetric) matrices of Frobenius norm one and given corank (the case of
matrices with zero determinant as a special case). We give asymptotic formulas
for our computations and we discuss several examples and applications.


title:
On the theory of inhomogeneous Bose-Einstein condensation of magnons in
  yttrium garnet

abstract:
  The Bose-Einstein condensation (BEC) of magnons created by a strong pumping
in ferromagnetic thin films of yttrium iron garnet used as systems of finite
size is considered analytically. Such a peculiarity, typical for this magnetic
material, as the presence of a minimum in the spectrum of spin waves at a
finite value of the wave vector is taken into account. The definition of
hightemperature BEC is introduced and its characteristics are discussed. A role
of boundary conditions for spin variables is analyzed, and it is shown that in
the case of free spins on the boundary the magnon lattice can form in the
system. The factors responsible for its appearance are discussed.


abstract:
  We consider Jordanian deformations of the AdS_5xS^5 superstring action. The
deformations correspond to non-standard q-deformation. In particular, it is
possible to perform partial deformations, for example, only for the S^5 part.
Then the classical action and the Lax pair are constructed with a linear,
twisted and extended R operator. It is shown that the action preserves the
kappa-symmetry.


title:
Average optimality for continuous-time Markov decision processes under
  weak continuity conditions

abstract:
  This article considers the average optimality for a continuous-time Markov
decision process with Borel state and action spaces and an arbitrarily
unbounded nonnegative cost rate. The existence of a deterministic stationary
optimal policy is proved under a different and general set of conditions as
compared to the previous literature; the controlled process can be explosive,
the transition rates can be arbitrarily unbounded and are weakly continuous,
the multifunction defining the admissible action spaces can be neither
compact-valued nor upper semi-continuous, and the cost rate is not necessarily
inf-compact.


title: A Genetic Algorithm to Optimize a Tweet for Retweetability

abstract:
  Twitter is a popular microblogging platform. When users send out messages,
other users have the ability to forward these messages to their own subgraph.
Most research focuses on increasing retweetability from a node's perspective.
Here, we center on improving message style to increase the chance of a message
being forwarded. To this end, we simulate an artificial Twitter-like network
with nodes deciding deterministically on retweeting a message or not. A genetic
algorithm is used to optimize message composition, so that the reach of a
message is increased. When analyzing the algorithm's runtime behavior across a
set of different node types, we find that the algorithm consistently succeeds
in significantly improving the retweetability of a message.


title:
Proceedings of the WAMSDO 2013 Workshop on Accelerator Magnet,
  Superconductor, Design and Optimization, CERN Geneva, Switzerland, 15 - 16
  Jan 2013

abstract:
  This report contains the proceedings of the Workshop on Accelerator Magnet
Superconductor, Design and Optimization (WAMSDO) held at CERN from 15 to 16
January 2013. This fourth edition of the WAMSDO workshop is focussed on aspects
related to quench protection.


title: Shallow water soliton dynamics beyond KdV

abstract:
  An alternative way for the derivation of the new KdV-type equation is
presented. The equation contains terms depending on the bottom topography
(there are six new terms in all, three of which are caused by the unevenness of
the bottom). It is obtained in the second order perturbative approach in the
weakly nonlinear, dispersive and long wavelength limit. Only treating all these
terms in the second order perturbation theory made the derivation of this
KdV-type equation possible. The motion of a wave, which starts as a KdV
soliton, is studied according to the new equation in several cases by numerical
simulations. The quantitative changes of a soliton's velocity and amplitude
appear to be directly related to bottom variations. Changes of the soliton's
velocity appear to be almost linearly anticorrelated with changes of water
depth whereas correlation of variation of soliton's amplitude with changes of
water depth looks less linear. When the bottom is flat, the new terms narrow
down the family of exact solutions, but at least one single soliton survives.
This is also checked by numerics.


title: Beamed Lyman Alpha Emission through Outflow-Driven Cavities

abstract:
  We investigate the radiative transfer of Lyman alpha photons through
simplified anisotropic gas distributions, which represent physically motivated
extensions of the popular 'shell-models'. Our study is motivated by the notion
that (i) shell models do not always reproduce observed Lyman alpha spectral
line profiles, (ii) (typical) shell models do not allow for the escape of
ionizing photons, and (iii) the observation & expectation that winds are more
complex, anisotropic phenomena. We examine the influence of inclination on the
Lyman alpha spectra, relative fluxes and escape fractions. We find the flux to
be enhanced/suppressed by factors up to a few depending on the parameter range
of the models, corresponding to a boost in equivalent width of the same
amplitude if we neglect dust. In general, lower mean optical depths tend to
reduce the impact of anisotropies as is expected. We find a correlation between
an observed peak in the -- occasionally triple-peaked -- spectrum at the
systemic velocity and the existence of a low optical depth cavity along the
line of sight. This can be of importance in the search for ionizing photons
leaking from high- redshift galaxies since these photons will also be able to
escape through the cavity.


title:
Realism and instrumentalism about the wave function. How should we
  choose?

abstract:
  The main claim of the paper is that one can be 'realist' (in some sense)
about quantum mechanics without requiring any form of realism about the wave
function. We begin by discussing various forms of realism about the wave
function, namely Albert's configuration-space realism, Duerr Zanghi and
Goldstein's nomological realism about the wave function, Esfeld's dispositional
reading of the wave function and Pusey Barrett and Rudolph's realism about the
quantum state. By discussing the articulation of these four positions, and
their interrelation, we conclude that instrumentalism about the wave function
is by itself not sufficient to choose one over the other interpretations of
quantum mechanics, thereby confirming in a different way the indetermination of
the metaphysical interpretations of quantum mechanics.


title:
Antifragility = Elasticity + Resilience + Machine Learning: Models and
  Algorithms for Open System Fidelity

abstract:
  We introduce a model of the fidelity of open systems - fidelity being
interpreted here as the compliance between corresponding figures of interest in
two separate but communicating domains. A special case of fidelity is given by
real-timeliness and synchrony, in which the figure of interest is the physical
and the system's notion of time. Our model covers two orthogonal aspects of
fidelity, the first one focusing on a system's steady state and the second one
capturing that system's dynamic and behavioural characteristics. We discuss how
the two aspects correspond respectively to elasticity and resilience and we
highlight each aspect's qualities and limitations. Finally we sketch the
elements of a new model coupling both of the first model's aspects and
complementing them with machine learning. Finally, a conjecture is put forward
that the new model may represent a first step towards compositional criteria
for antifragile systems.


title:
Functional inequalities for generalized inverse trigonometric and
  hyperbolic functions

abstract:
  Various miscellaneous functional inequalities are deduced for the so-called
generalized inverse trigonometric and hyperbolic functions. For instance,
functional inequalities for sums, difference and quotient of generalized
inverse trigonometric and hyperbolic functions are given, as well as some
Gr\"unbaum inequalities with the aid of the classical Bernoulli inequality.
Moreover, by means of certain already derived bounds, bilateral bounding
inequalities are obtained for the generalized hypergeometric ${}_3F_2$ Clausen
function.


title: Coupled orbital-thermal evolution of Miranda

abstract:
  Miranda has a unusually high inclination ($I=4.338^\circ$), and its surface
reveals signs of past endogenic activity. Investigations of the dynamical
aspects of its orbital evolution suggest probable resonant processes, in
particular with Umbriel, as an explanation for the present high inclination of
Miranda. The tidal heating induced by gravitational interactions can lead to
the rise of eccentricities and, consequently, to the increased dissipation of
energy inside the satellite and higher internal temperatures. We study here the
possible increase in eccentricities caused by orbital resonances and the
resulting endogenic heating on Miranda taking into account its temperature
dependent rheology. The coupled orbital-thermal evolution model was run with
different rheological models and the thermal parameters starting form a cold
thermal state, in radiative equilibrium with the environment. For the nominal
parameters of the evolution scenarios studied, the resonances were not
sufficient to rise neither the eccentricities nor the internal temperatures
significantly. Lowest dissipation function $Q$ of around 100 and final
eccentricity of $e\approx0.02$ were obtained during the resonance 3:1 with
Umbriel.


title:
Proximal algorithms with Bregman distances for bilevel equilibrium
  problems with application to the problem of "how routines form and change" in
  Economics and Management Sciences

abstract:
  In this paper we present the bilevel equilibrium problem under conditions of
pseudomonotonicity. Using Bregman distances on Hadamard manifolds we propose a
framework for to analyse the convergence of a proximal point algorithm to solve
this bilevel equilibrium problem. As an application, we consider the problem of
"how routines form and change" which is crucial for the dynamics of
organizations in Economics and Management Sciences.


title:
Gluon saturation and initial conditions for relativistic heavy ion
  collisions

abstract:
  We present an overview of theoretical aspects of the phenomenon of gluon
saturation in high energy scattering in Quantum Chromo Dynamics. Then we review
the state-of-the-art of saturation-based phenomenological approaches to the
study and characterisation of the initial state of ultra-relativistic heavy ion
collisions performed at RHIC and the LHC. Our review focuses mostly in the
Color Glass Condensate effective theory, although we shall also discuss other
approaches in parallel.


title:
Full characterization of a highly multimode entangled state embedded in
  an optical frequency comb using pulse shaping

abstract:
  We present a detailed analysis of the multimode quantum state embedded in an
optical frequency comb generated by a Synchronously Pumped Optical Parametric
Oscillator (SPOPO). The full covariance matrix of the state is obtained with
homodyne detection where the local oscillator is spectrally controlled with
pulse shaping techniques. The resulting matrix reveals genuine multipartite
entanglement. Additionally, the beam is comprised of several independent
eigenmodes that correspond to specific pulse shapes. The experimental data is
confirmed with numerical simulations. Finally, the potential to create
continuous-variable cluster states from the quantum comb is analyzed. Multiple
cluster states are shown to be simultaneously embedded in the SPOPO state, and
these states can be revealed by a suitable basis change applied to the measured
covariance matrix.


title:
High-visibility nonclassical interference of photon pairs generated in a
  multimode nonlinear waveguide

abstract:
  We report measurements of two-photon interference using a cw-pumped type-II
spontaneous parametric down-conversion source based on a multimode perodically
poled potassium titanyl phosphate waveguide. We have used the recently
demonstrated technique of controlling the spatial characteristics of the
down-conversion process via intermodal dispersion to generate photon pairs in
fundamental transverse modes, thus ensuring their spatial indistinguishability.
Good spatial overlap of photon modes within pairs has been verified using the
Hong-Ou-Mandel interferometer and the preparation of polarization entanglement
in the Shih-Alley configuration, yielding visibilities consistently above 90%.


title: Does Syntactic Knowledge help English-Hindi SMT?

abstract:
  In this paper we explore various parameter settings of the state-of-art
Statistical Machine Translation system to improve the quality of the
translation for a `distant' language pair like English-Hindi. We proposed new
techniques for efficient reordering. A slight improvement over the baseline is
reported using these techniques. We also show that a simple pre-processing step
can improve the quality of the translation significantly.


title: From 'nothing' to inflation and back again

abstract:
  A procedure for solving Wheeler-DeWitt equation in Euclidean region,
following step by step the construction of tunneling wave function in
nonrelativistic quantum mechanics by Banks, Bender and Wu, is proposed.
Solutions for a universe satisfying no-boundary condition and a universe
created from 'nothing' are compared to the corresponding solutions for a
particle in a two-dimensional potential well, and effects of indefiniteness of
metric and zero energy in Wheeler-DeWitt equation are discussed.


title: The Eigencurve is Proper

abstract:
  We prove that the Coleman-Mazur eigencurve is proper over the weight space
for any prime p and tame level N.


title: Classification of IDS Alerts with Data Mining Techniques

abstract:
  A data mining technique to reduce the amount of false alerts within an IDS
system is proposed. The new technique achieves an accuracy of 99% compared to
97% by the current systems.


title: Optical properties of ZnCoO films and nanopowders

abstract:
  ZnCoO is one of the most studied and promising semiconductor materials for
spintronics applications. In this work we discuss optical and electrical
properties of ZnCoO films and nanoparticles grown at low temperature by either
Atomic Layer Deposition or by a microwave driven hydrothermal method. We report
that doping with Cobalt quenches a visible photoluminescence (PL) of ZnO. We
could observe a visible PL of ZnO only for samples with very low Co fractions
(up to 1%). Mechanisms of PL quenching in ZnCoO are discussed. We also found
that ZnO films remained n-type conductive after doping with Co, indicating that
a high electron concentration and Cobalt 2+ charge state can coexist.


title: Self-assembling tensor networks and holography in disordered spin chains

abstract:
  We show that the numerical strong disorder renormalization group algorithm
(SDRG) of Hikihara et. al. [Phys. Rev. B 60, 12116 (1999)] for the
one-dimensional disordered Heisenberg model naturally describes a tree tensor
network (TTN) with an irregular structure defined by the strength of the
couplings. Employing the holographic interpretation of the TTN in Hilbert
space, we compute expectation values, correlation functions and the
entanglement entropy using the geometrical properties of the TTN. We find that
the disorder averaged spin-spin correlation scales with the average path length
through the tensor network while the entanglement entropy scales with the
minimal surface connecting two regions. Furthermore, the entanglement entropy
increases with both disorder and system size, resulting in an area-law
violation. Our results demonstrate the usefulness of a self-assembling TTN
approach to disordered systems and quantitatively validate the connection
between holography and quantum many-body systems.


title:
Kane-Mele Hubbard model on a zigzag ribbon: stability of the topological
  edge states and quantum phase transitions

abstract:
  We study the quantum phases and phase transitions of the Kane-Mele Hubbard
(KMH) model on a zigzag ribbon of honeycomb lattice at a finite size via the
weak-coupling renormalization group (RG) approach. In the non-interacting
limit, the KM model is known to support topological edge states where electrons
show helical property with orientations of the spin and momentum being locked.
The effective inter-edge hopping terms are generated due to finite-size effect.
In the presence of an on-site Coulomb repulsive interaction and the inter-edge
hoppings, special focus is put on the stability of the topological edge states
(TI phase) in the KMH model against (i) the charge and spin gaped (II) phase,
(ii) the charge gaped but spin gapless (IC) phase and (iii) the spin gaped but
charge gapless (CI) phase depending on the number (even/odd) of the zigzag
ribbons, doping level (electron filling factor) and the ratio of the Coulomb
interaction to the inter-edge tunneling. We discuss different phase diagrams
for even and odd numbers of zigzag ribbons. We find the TI-CI, II-IC, and II-CI
quantum phase transitions are of the Kosterlitz-Thouless (KT) type. By
computing various correlation functions, we further analyze the nature and
leading instabilities of these phases.


title:
The critical factors affecting E-Government adoption: A Conceptual
  Framework in Vietnam

abstract:
  Electronic government (e-government) has established as an effective
mechanism for increasing government productivity and efficiency and a key
enabler of citizen- centric services. However, e-government implementation is
surrounded by technological, governing and social issues, which have to be
considered and treated carefully in order to facilitate this change. This
research attempts to explore and investigate the key challenges that influence
e-government implementation and the factors influencing citizen adoption in
Vietnam. It develops a conceptual framework on the basis of existing
experiences drawn from administrative reforms. Survey data from public employee
will be used to test the proposed hypothesis and the model. Therefore, this
research has identified factors that determine if the citizen will adopt
E-government services and thereby aiding governments in accessing what is
required to increase adoption. We will also highlight several research,
practitioner and policy implications.


title:
Physical Properties of White-Light Sources in the 2011 Feb 15 Solar
  Flare

abstract:
  White light flares (WLFs) are observational rarities, making them
understudied events. However, optical emission is a significant contribution to
flare energy budgets and the emission mechanisms responsible could have
important implications for flare models. Using Hinode SOT optical continuum
data taken in broadband red, green and blue filters, we investigate white-light
emission from the X2.2 flare SOL2011-02-15T01:56:00. We develop a technique to
robustly identify enhanced flare pixels and, using a knowledge of the RGB
filter transmissions, determined the source color temperature and effective
temperature. We investigated two idealized models of WL emission - an optically
thick photospheric source, and an optically thin chromospheric slab. Under the
optically thick assumption, the color temperature and effective temperature of
flare sources in sunspot umbra and penumbra were determined as a function of
time and position. Values in the range of 5000-6000K were found, corresponding
to a blackbody temperature increase of a few hundred kelvin. The power emitted
in the optical was estimated at $\sim 10^{26}$ergs s$^{-1}$. In some of the
white-light sources the color and blackbody temperatures are the same within
uncertainties, consistent with a blackbody emitter. In other regions this is
not the case, suggesting that some other continuum emission process is
contributing. An optically thin slab model producing hydrogen recombination
radiation is also discussed as a potential source of WL emission; it requires
temperatures in the range 5,500 - 25,000K, and total energies of $\sim
10^{27}$ergs s$^{-1}$.


title:
The GIRAFFE Inner Bulge Survey (GIBS). I. Survey Description and a
  kinematical map of the Milky Way bulge

abstract:
  The Galactic bulge is a massive, old component of the Milky Way. It is known
to host a bar, and it has recently been demonstrated to have a pronounced
boxy/peanut structure in its outer region. Several independent studies suggest
the presence of more than one stellar populations in the bulge, with different
origins and a relative fraction changing across the bulge area. This is the
first of a series of papers presenting the results of the Giraffe Inner Bulge
Survey, carried out at the ESO-VLT with the multifibre spectrograph FLAMES.
Spectra of ~5000 red clump giants in 24 bulge fields have been obtained at
resolution R=6500, in the infrared Calcium triplet wavelength region at 8500
{\AA}. They are used to derive radial velocities and metallicities, based on
new calibration specifically devised for this project. Radial velocities for
another ~1200 bulge red clump giants, obtained from similar archive data, have
been added to the sample. Higher resolution spectra have been obtained for 450
additional stars at latitude b=-3.5, with the aim of investigating chemical
abundance patterns variations with longitude, across the inner bulge. In total
we present here radial velocities for 6392 RC stars. We derive a radial
velocity, and velocity dispersion map of the Milky Way bulge, useful to be
compared with similar maps of external bulges, and to infer the expected
velocities and dispersion at any line of sight. The K-type giants kinematics is
consistent with the cylindrical rotation pattern of M-giants from the BRAVA
survey. Our sample enables to extend this result to latitude b=-2, closer to
the Galactic plane than probed by previous surveys. Finally, we find strong
evidence for a velocity dispersion peak at (0,-1) and (0,-2), possibly
indicative of a high density peak in the central 250 pc of the bulge


title: On the Computing Power of $+$, $-$, and $\times$

abstract:
  Modify the Blum-Shub-Smale model of computation replacing the permitted
computational primitives (the real field operations) with any finite set $B$ of
real functions semialgebraic over the rationals. Consider the class of boolean
decision problems that can be solved in polynomial time in the new model by
machines with no machine constants. How does this class depend on $B$? We prove
that it is always contained in the class obtained for $B = \{+, -, \times\}$.
Moreover, if $B$ is a set of continuous semialgebraic functions containing $+$
and $-$, and such that arbitrarily small numbers can be computed using $B$,
then we have the following dichotomy: either our class is $\mathsf P$ or it
coincides with the class obtained for $B = \{+, -, \times\}$.


title: On n-dependent groups and fields

abstract:
  First, an example of a 2-dependent group without a minimal subgroup of
bounded index is given. Second, all infinite n-dependent fields are shown to be
Artin-Schreier closed. Furthermore, the theory of any non separably closed PAC
field has the IPn property for all natural numbers n and certain properties of
dependent (NIP) valued fields extend to the n-dependent context.


title: Partial and Quasi Dynamical Symmetries in Nuclei

abstract:
  One of the interesting aspects in the study of atomic nuclei is the
strikingly regular behaviour many display in spite of being complex
quantum-mechanical systems, prompting the universal question of how regularity
emerges out of complexity. It is often conjectured that symmetries play a
pivotal role in our understanding of this emerging simplicity. But most
symmetries are likely to be broken, partial or both. Under such more realistic
conditions, does the concept of symmetry still provide a basis for our
understanding of regularity? I suggest that this requires the enlarged concepts
of partial and quasi dynamical symmetry.