title: Zooming towards the Event Horizon - mm-VLBI today and tomorrow

abstract:
  Global VLBI imaging at millimeter and sub-millimeter wavelength overcomes the
opacity barrier of synchrotron self-absorption in AGN and opens the direct view
into sub-pc scale regions not accessible before. Since AGN variability is more
pronounced at short millimeter wavelength, mm-VLBI can reveal structural
changes in very early stages after outbursts. When combined with observations
at longer wavelength, global 3mm and 1mm VLBI adds very detailed information.
This helps to determine fundamental physical properties at the jet base, and in
the vicinity of super-massive black holes at the center of AGN. Here we present
new results from multi-frequency mm-VLBI imaging of OJ287 during a major
outburst. We also report on a successful 1.3mm VLBI experiment with the APEX
telescope in Chile. This observation sets a new record in angular resolution.
It also opens the path towards future mm-VLBI with ALMA, which aims at the
mapping of the black hole event horizon in nearby galaxies, and the study of
the roots of jets in AGN.


title:
Discussion on common errors in analyzing sea level accelerations, solar
  trends and global warming

abstract:
  Errors in applying regression models and wavelet filters used to analyze
geophysical signals are discussed: (1) multidecadal natural oscillations (e.g.
the quasi 60-year Atlantic Multidecadal Oscillation (AMO), North Atlantic
Oscillation (NAO) and Pacific Decadal Oscillation (PDO)) need to be taken into
account for properly quantifying anomalous accelerations in tide gauge records
such as in New York City; (2) uncertainties and multicollinearity among climate
forcing functions prevent a proper evaluation of the solar contribution to the
20th century global surface temperature warming using overloaded linear
regression models during the 1900-2000 period alone; (3) when periodic wavelet
filters, which require that a record is pre-processed with a reflection
methodology, are improperly applied to decompose non-stationary solar and
climatic time series, Gibbs boundary artifacts emerge yielding misleading
physical interpretations. By correcting these errors and using optimized
regression models that reduce multicollinearity artifacts, I found the
following results: (1) the sea level in New York City is not accelerating in an
alarming way, and may increase by about 350 mm from 2000 to 2100 instead of the
previously projected values varying from 1130 mm to 1550 mm estimated using the
methods proposed by Sallenger et al. (2012) and Boon (2012), respectively; (2)
the solar activity increase during the 20th century contributed about 50% of
the 0.8 K global warming observed during the 20th century instead of only 7-10%
(IPCC, 2007; Benestad and Schmidt, 2009; Lean and Rind, 2009). These findings
stress the importance of natural oscillations and of the sun to properly
interpret climatic changes.


title: On mod $p$ singular modular forms

abstract:
  We show that an elliptic modular form with integral Fourier coefficients in a
number field $K$, for which all but finitely many coefficients are divisible by
a prime ideal $\frak{p}$ of $K$, is a constant modulo $\frak{p}$. A similar
property also holds for Siegel modular forms. Moreover, we define the notion of
mod $\frak{p}$ singular modular forms and discuss some relations between their
weights and the corresponding prime $p$. We discuss some examples of mod
$\frak{p}$ singular modular forms arising from Eisenstein series and from theta
series attached to lattices with automorphisms. Finally, we apply our results
to properties mod $\frak{p}$ of Klingen-Eisenstein series.


title:
High energy modifications of blackbody radiation and dimensional
  reduction

abstract:
  Quantization prescriptions that realize generalized uncertainty relations
(GUP) are motivated by quantum gravity arguments that incorporate a fundamental
length scale. We apply two such methods, polymer and deformed Heisenberg
quantization, to scalar field theory in Fourier space. These alternative
quantizations modify the oscillator spectrum for each mode, which in turn
affects the blackbody distribution. We find that for a large class of
modifications, the equation of state relating pressure $P$ and energy density
$\rho$ interpolates between $P=\rho/3$ at low $T$ and $P=2\rho/3$ at high $T$,
where $T$ is the temperature. Furthermore, the Stefan-Boltzman law gets
modified from $\rho \propto T^{4}$ to $\rho \propto T^{5/2}$ at high
temperature. This suggests an effective reduction to 2.5 spacetime dimensions
at high energy.


title:
Modelling time and vintage variability in retail credit portfolios: the
  decomposition approach

abstract:
  In this paper, we consider the problem of modelling historical data on retail
credit portfolio performance, with a view to forecasting future performance,
and facilitating strategic decision making. We consider a situation, common in
practice, where accounts with common origination date (typically month) are
aggregated into a single vintage for analysis, and the data for analysis
consists of a time series of a univariate portfolio performance variable (for
example, the proportion of defaulting accounts) for each vintage over
successive time periods since origination. An invaluable management tool for
understanding portfolio behaviour can be obtained by decomposing the data
series nonparametrically into components of exogenous variability (E), maturity
(time since origination; M) and vintage (V), referred to as an EMV model. For
example, identification of a good macroeconomic model is the key to effective
forecasting, particularly in applications such as stress testing, and
identification of this can be facilitated by investigation of the macroeconomic
component of an EMV decomposition. We show that care needs to be taken with
such a decomposition, drawing parallels with the Age-Period-Cohort approach,
common in demography, epidemiology and sociology. We develop a practical
decomposition strategy, and illustrate our approach using data extracted from a
credit card portfolio.


title: Quantum instruments as a foundation for both states and observables

abstract:
  We demonstrate that quantum instruments can provide a unified operational
foundation for quantum theory. Since these instruments directly correspond to
laboratory devices, this foundation provides an alternate, more experimentally
grounded, perspective from which to understand the elements of the traditional
approach. We first show that in principle all measurable probabilities and
correlations can be expressed entirely in terms of quantum instruments without
the need for conventional quantum states or observables. We then show how these
states and observables reappear as derived quantities by conditioning joint
detection probabilities on the first or last measurement in a sequence as a
preparation or a post-selection. Both predictive and retrodictive versions of
states and observables appear in this manner, as well as more exotic
bidirectional and interdictive states and observables that cannot be easily
expressed using the traditional approach. We also revisit the conceptual
meaning of the Heisenberg and Schr\"{o}dinger pictures of time evolution as
applied to the various derived quantities, illustrate how detector loss can be
included naturally, and discuss how the instrumental approach fully generalizes
the time-symmetric two-vector approach of Aharonov \emph{et al.} to any
realistic laboratory situation.


title:
Absence of exponential sensitivity to small perturbations in
  nonintegrable systems of spins 1/2

abstract:
  We show that macroscopic nonintegrable lattices of spins 1/2, which are often
considered to be chaotic, do not exhibit the basic property of classical
chaotic systems, namely, exponential sensitivity to small perturbations. We
compare chaotic lattices of classical spins and nonintegrable lattices of spins
1/2 in terms of their magnetization responses to imperfect reversal of spin
dynamics known as Loschmidt echo. In the classical case, magnetization exhibits
exponential sensitivity to small perturbations of Loschmidt echoes, which is
characterized by twice the value of the largest Lyapunov exponent of the
system. In the case of spins 1/2, magnetization is only power-law sensitive to
small perturbations. Our findings imply that it is impossible to define
Lyapunov exponents for lattices of spins 1/2 even in the macroscopic limit. At
the same time, the above absence of exponential sensitivity to small
perturbations is an encouraging news for the efforts to create quantum
simulators. The power-law sensitivity of spin 1/2 lattices to small
perturbations is predicted to be measurable in nuclear magnetic resonance
experiments.


title: Entanglement criteria for Dicke states

abstract:
  Dicke states are a family of multi-qubit quantum states with interesting
entanglement properties and have been observed in many experiments. We
construct entanglement witnesses for detecting genuine multiparticle
entanglement in the vicinity of these states. We use the approach of PPT
mixtures to derive the conditions analytically. For nearly all cases, our
criteria are stronger than all conditions previously known.


title:
Comments on the reach of INO experiment: JHEP 1304, 009 (2013) and
  arXiv:1303.2534 [hep-ph]

abstract:
  In JHEP {\bf 1304}, 009 (2013) and arXiv:1303.2534 [hep-ph] the {\it reach of
INO experiment} for determination of neutrino mass hierarchy and the
sensitivity to both $\Delta m_{32}^2$ and $\theta_{23}$ have been reported,
which are significantly underestimated and drastically different from earlier
studies JHEP {\bf 1107}, 048 (2011), Phys. Rev. D {\bf 81}, 037302 (2010) and
strongly dependent on the flux uncertainties. Here, we clarified that the
effect on oscillation probability due to change of oscillation parameters are
not considered appropriately due to improper binning of data, improper
incorporation of resolutions, and rejection of high energy events $E\gapp $ 10
GeV.


title: Interaction and disorder effects in 3D topological insulator thin films

abstract:
  A theory of combined interference and interaction effects on the diffusive
transport properties of 3D topological insulator surface states is developed.
We focus on a slab geometry (characteristic for most experiments) and show that
interactions between the top and bottom surfaces are important at not too high
temperatures. We treat the general case of different surfaces (different
carrier densities, uncorrelated disorder, arbitrary dielectric environment,
etc.). In order to access the low-energy behavior of the system we renormalize
the interacting diffusive sigma model in the one loop approximation. It is
shown that intersurface interaction is relevant in the renormalization group
(RG) sense and the case of decoupled surfaces is therefore unstable. An
analysis of the emerging RG flow yields a rather rich behavior. We discuss
realistic experimental scenarios and predict a characteristic non-monotonic
temperature dependence of the conductivity. In the infrared (low-temperature)
limit, the systems flows into a metallic fixed point. At this point, even
initially different surfaces have the same transport properties. Investigating
topological effects, we present a local expression of the $\mathbb Z_2$ theta
term in the sigma model by first deriving the Wess-Zumino-Witten theory for
class DIII by means of non-abelian bosonization and then breaking the symmetry
down to AII. This allows us to study a response of the system to an external
electromagnetic field. Further, we discuss the difference between the system of
Dirac fermions on the top and bottom surfaces of a topological insulator slab
and its non-topological counterpart in a double-well structure with strong
spin-orbit interaction.


title:
Introducing the Eulalia and new Polana asteroid families: re-assessing
  primitive asteroid families in the inner Main Belt

abstract:
  The so-called Nysa-Polana complex of asteroids is a diverse and widespread
group. It appears to be two overlapping families of different asteroid
taxonomies: (44) Nysa is an E-type asteroid with the lowest number in the midst
of a predominantly S-type cluster and (142) Polana is a B-type asteroid near
the low-albedo B- and C-type cluster.
  Using the data from the Wide-field Infrared Survey Explorer (WISE) mission we
have re-analyzed the region around the Nysa-Polana complex in the inner Main
Belt, focusing on the low-albedo population. (142) Polana does not appear to be
a member of the family of low-albedo asteroids in the Nysa-Polana complex.
Rather, the largest is asteroid (495) Eulalia. This asteroid has never before
been linked to this complex for an important dynamical reason: it currently has
a proper eccentricity slightly below the range of most of the family members.
However, its orbit is very close to the 3:1 mean motion resonance with Jupiter
and is in a weak secular resonance. We show that its osculating eccentricity
varies widely on short timescales and the averaged value diffuses over long
timescales. The diffusive orbit, low-albedo, taxonomic similarity and semimajor
axis strongly suggests that despite its current proper eccentricity, (495)
Eulalia could have recently been at an orbit very central to the family.
Hierarchical Clustering Method tests confirm that at an eccentricity of e=0.15,
(495) Eulalia could be the parent of the family. The ``Eulalia family'' was
formed between 900--1500 Myr ago, and likely resulted from the breakup of a
100--160 km parent body. There is also compelling evidence for an older and
more widespread primitive family in the same region of the asteroid belt
parented by asteroid (142) Polana.


title:
Work distribution and edge singularities for generic time-dependent
  protocols in extended systems

abstract:
  We study the statistics of the work done by globally changing in time with a
generic protocol the mass in a free bosonic field theory with relativistic
dispersion and the transverse field in the one-dimensional Ising chain both
globally and locally. In the latter case we make the system start from the
critical point and we describe it in the scaling limit. We provide exact
formulas in all these cases for the full statistics of the work and we show
that the low energy part of the distribution of the work displays an edge
singularity whose exponent does not depend on the specifics of the protocol
that is chosen, and may only depend on the position of the initial and final
value with respect to the critical point of the system. We also show that the
condensation transition found in the bosonic system for sudden quenches [A.
Gambassi and A. Silva, Phys. Rev. Lett. {\bf 109}, 250602 (2012)] is robust
with respect to the choice of the protocol.


title:
Observation of Dirac node formation and mass acquisition in a
  topological crystalline insulator

abstract:
  In the recently discovered topological crystalline insulators (TCIs),
topology and crystal symmetry intertwine to create surface states with a unique
set of characteristics. Among the theoretical predictions for TCIs is the
possibility of imparting mass to the massless Dirac fermions by breaking
crystal symmetry, as well as a Lifshitz transition with a change of Fermi
surface topology. Here we report high resolution scanning tunneling microscopy
studies of a TCI, Pb1-xSnxSe. We demonstrate the formation of zero mass Dirac
fermions protected by crystal symmetry and the mechanism of mass generation via
symmetry breaking, which constitute the defining characteristics of TCIs. In
addition, we show two distinct regimes of fermiology separated by a Van-Hove
singularity at the Lifshitz transition point. Our work paves the way for
engineering the Dirac band gap and realizing interaction-driven topological
quantum phenomena in TCIs.


title:
The Statistical and Econometric Analysis of Asylum Application Trends
  and their relationship to GDP in the EEA

abstract:
  The sharp decline in Ireland's economic performance in recent years has
coincided with a recent fall in asylum applications. Simultaneously countries
such as Switzerland are seeing increases in asylum numbers with evidence for
greater numbers of Nigerian applicants, a group that have for some time been
the largest nationality group applying in Ireland. A possible reason for this
shift in asylum seeker preference is the general economic conditions here
versus those in other European countries. In this paper we investigate whether
this belief holds water. We model asylum applications as a function of GDP
using a time varying parameter multiplicative growth model. Our results show
there is an economic basis for asylum seeker preferences. We further show there
is no regional basis for asylum seekers' expectation of a more favourable claim
in the 'developed box' in central Europe as compared to countries on the
so-called 'periphery'.


title:
A resonant family of dynamically cold small bodies in the near-Earth
  asteroid belt

abstract:
  Near-Earth objects (NEOs) moving in resonant, Earth-like orbits are
potentially important. On the positive side, they are the ideal targets for
robotic and human low-cost sample return missions and a much cheaper
alternative to using the Moon as an astronomical observatory. On the negative
side and even if small in size (2-50 m), they have an enhanced probability of
colliding with the Earth causing local but still significant property damage
and loss of life. Here, we show that the recently discovered asteroid 2013 BS45
is an Earth co-orbital, the sixth horseshoe librator to our planet. In contrast
with other Earth's co-orbitals, its orbit is strikingly similar to that of the
Earth yet at an absolute magnitude of 25.8, an artificial origin seems
implausible. The study of the dynamics of 2013 BS45 coupled with the analysis
of NEO data show that it is one of the largest and most stable members of a
previously undiscussed dynamically cold group of small NEOs experiencing
repeated trappings in the 1:1 commensurability with the Earth. This new
resonant family is well constrained in orbital parameter space and it includes
at least 10 other transient members: 2003 YN107, 2006 JY26, 2009 SH2 and 2012
FC71 among them. 2012 FC71 represents the best of both worlds as it is locked
in a Kozai resonance and is unlikely to impact the Earth. Objects in this group
could be responsible for the production of Earth's transient irregular natural
satellites.


title: Yoga of Commutators in Roy's Elementary Orthogonal Group

abstract:
  In this article, we give explicit proofs of certain commutator relations
among the elementary generators of the elementary orthogonal group $EO_A(Q\perp
H(P))$, where $A$ is a commutative ring, $Q$ is a non-singular quadratic
$A$-space and $H(P)$ is the hyperbolic space of a finitely generated projective
module $P$ with the natural quadratic form. Using these relations, we
established a local-global principle of D. Quillen for the
Dickson--Siegel--Eichler--Roy (DSER) elementary orthogonal transformations in
\cite{aarr}. In \cite{aa1}, by using these commutator relations, we prove the
normality of this elementary group in the orthogonal group under some
conditions on the hyperbolic rank. Also, these relations are used to obtain
further information about this orthogonal group and in comparing it with
similar groups such as Hermitian groups and odd unitary groups.


title: Human Mood Detection For Human Computer Interaction

abstract:
  In this paper we propose an easiest approach for facial expression
recognition. Here we are using concept of SVM for Expression Classification.
Main problem is sub divided in three main modules. First one is Face detection
in which we are using skin filter and Face segmentation. We are given more
stress on feature Extraction. This method is effective enough for application
where fast execution is required. Second, Facial Feature Extraction which is
essential part for expression recognition. In this module we used Edge
Projection Analysis. Finally extracted features vector is passed towards SVM
classifier for Expression Recognition. We are considering six basic Expressions
(Anger, Fear, Disgust, Joy, Sadness, and Surprise)


title: Image Optimization and Prediction

abstract:
  Image Processing, Optimization and Prediction of an Image play a key role in
Computer Science. Image processing provides a way to analyze and identify an
image .Many areas like medical image processing, Satellite images, natural
images and artificial images requires lots of analysis and research on
optimization. In Image Optimization and Prediction we are combining the
features of Query Optimization, Image Processing and Prediction . Image
optimization is used in Pattern analysis, object recognition, in medical Image
processing to predict the type of diseases, in satellite images for predicting
weather forecast, availability of water or mineral etc. Image Processing,
Optimization and analysis is a wide open area for research .Lots of research
has been conducted in the area of Image analysis and many techniques are
available for image analysis but, a single technique is not yet identified for
image analysis and prediction .our research is focused on identifying a global
technique for image analysis and Prediction.


title:
Jumps in entropy and magnetic susceptibility at the valence and
  spin-state transition in a cobalt oxide

abstract:
  A wide family of cobalt oxides of formulation (Pr,Ln,Ca)CoO3 (Ln being a
lanthanide) exhibits a coupled valence and spin-state transition (VSST) at a
temperature T*, which involves two concomitant modifications: (i) a change in
the spin state of Co3+ from low-spin (T < T*) to a higher spin-state (T > T*),
and (ii) a change in the valence state of Pr, from a mixed Pr4+/Pr3+ state (T <
T*) to a purely trivalent state (T > T*), accompanied by an equivalent charge
transfer within the Co3+/Co4+ subsystem. In the present paper, the VSST taking
place in (Pr0.7Sm0.3)0.7Ca0.3CoO3 at T* = about 90 K is investigated by
magnetization and heat capacity measurements. First, we quantitatively
characterized the jumps in magnetic susceptibility (khi) and entropy (S) around
T*. Then, these values were compared to those calculated as a function of the
variations in the population of the different cationic species involved in the
VSST. X-ray absorption spectroscopy experiments recently showed that the higher
spin state above T* should be regarded as an inhomogeneous mixture between
low-spin (LS) and high-spin (HS) states. In the frame of this description, we
demonstrate that the jumps in both khi and S can be associated to the same
change in the Co3+ HS content around T*. This result lends further support to
the relevance of the LS/HS picture for the VSST, challenging the currently
dominant interpretation based on the occurrence of an intermediate-spin (IS)
state of Co3+ above T*.


title:
Performance Enhancement of Distributed Quasi Steady-State Genetic
  Algorithm

abstract:
  This paper proposes a new scheme for performance enhancement of distributed
genetic algorithm (DGA). Initial population is divided in two classes i.e.
female and male. Simple distance based clustering is used for cluster formation
around females. For reclustering self-adaptive K-means is used, which produces
well distributed and well separated clusters. The self-adaptive K-means used
for reclustering automatically locates initial position of centroids and number
of clusters. Four plans of co-evolution are applied on these clusters
independently. Clusters evolve separately. Merging of clusters takes place
depending on their performance. For experimentation unimodal and multimodal
test functions have been used. Test result show that the new scheme of
distribution of population has given better performance.


title: Test Model for Text Categorization and Text Summarization

abstract:
  Text Categorization is the task of automatically sorting a set of documents
into categories from a predefined set and Text Summarization is a brief and
accurate representation of input text such that the output covers the most
important concepts of the source in a condensed manner. Document Summarization
is an emerging technique for understanding the main purpose of any kind of
documents. This paper presents a model that uses text categorization and text
summarization for searching a document based on user query.


title:
Decoupling of Fourier Reconstruction System for Shifts of Several
  Signals

abstract:
  We consider the problem of ``algebraic reconstruction'' of linear
combinations of shifts of several signals $f_1,\ldots,f_k$ from the Fourier
samples. For each $r=1,\ldots,k$ we choose sampling set $S_r$ to be a subset of
the common set of zeroes of the Fourier transforms ${\cal F}(f_\l), \ \l \ne
r$, on which ${\cal F}(f_r)\ne 0$. We show that in this way the reconstruction
system is reduced to $k$ separate systems, each including only one of the
signals $f_r$. Each of the resulting systems is of a ``generalized Prony''
form. We discuss the problem of unique solvability of such systems, and provide
some examples.


title:
Analysis of one-dimensional Yut-Nori game: winning strategy and
  avalanche-size distribution

abstract:
  In the Korean traditional board game Yut-Nori, teams compete by moving their
pieces on the two-dimensional game board, and the team whose all pieces
complete a round trip on the board wins. In every round, teams throw four
wooden sticks of the shape of half-cut cylinder and the number of sticks that
show belly sides, i.e., the flat sides, determines the number of steps the
team's piece can advance on the board. It is possible to pile up one team's
pieces if their sites are identical so that pieces as a group can move together
afterwards (piling). If a piece of the opponent team is at the new site of one
team's piece, the piece is caught and removed from the board, and the team is
given one more chance to throw sticks and proceed (catching). For a simplicity,
we simulate this game on one-dimensional board with the same number of sites as
the original game, and show that catching is more advantageous strategy than
piling to win. We also study the avalanche-size distribution in thermodynamic
limit to find that it follows an exponential form.


title: Calculus of functors and model categories II

abstract:
  This is a continuation, completion, and generalization of our previous joint
work with B. Chorny. We supply model structures and Quillen equivalences
underlying Goodwillie's constructions on the homotopy level for functors
between simplicial model categories satisfying mild hypotheses.


title: Dynamic Top-$k$ Dominating Queries

abstract:
  Let $\mathcal{S}$ be a dataset of $n$ 2-dimensional points. The top-$k$
dominating query aims to report the $k$ points that dominate the most points in
$\mathcal{S}$. A point $p$ dominates a point $q$ iff all coordinates of $p$ are
smaller than or equal to those of $q$ and at least one of them is strictly
smaller. The top-$k$ dominating query combines the dominance concept of maxima
queries with the ranking function of top-$k$ queries and can be used as an
important tool in multi-criteria decision making systems. In this work, we
propose novel algorithms for answering semi-dynamic (insertions only) and fully
dynamic (insertions and deletions) top-$k$ dominating queries. To the best of
our knowledge, this is the first work towards handling (semi-)dynamic top-$k$
dominating queries that offers algorithms with asymptotic guarantees regarding
their time and space cost.


title: Infrastructure to Vehicle Real Time Secured Communication

abstract:
  Among civilian communication systems, vehicular networks emerge as one of the
most is convincing and yet most challenging instantiations of the mobile ad hoc
networking technology. Towards the deployment of vehicular communication
systems, security and privacy are critical factors and significant challenges
to be met. This Vehicular communication (VC) system has the potential to
improve road safety and driving comfort. Nevertheless, securing the operation
is a prerequisite for deployment so in this paper we are focusing on real time
experimental design of infrastructure to vehicle communication. We outline how
VANET will be a better option than GPS technology. We also try to discuss IP
address passing using DHCP in the network and the security issues.


title: An Algorithm to Improve Performance over Multihop Wireless Mesh Network

abstract:
  Transmission Control Protocol (TCP) is the dominant reliable transport
protocol utilized in the Internet. Improving the performance of TCP associated
with the presence of multi-hop is one of the research challenges in wireless
mesh networks. Wireless mesh networks have large round trip time variations and
these variations are dependent on the number of hops. In wireless mesh network,
when congestion loss and wireless loss are co-existed the number of packets
dropped increases and will have adverse effects on TCP and its congestion
control mechanism which leads to low throughput. Here we have designed a new
TCP scheme for multi-hop wireless mesh networks, by modifying the sender side
congestion control functionality of TCP NewReno, which is tuned towards
improving the performance of TCP. The simulation results show that TCP SAC has
higher performance than TCP NewReno, Reno, Sack and Vegas in multi-hop wireless
mesh networks.


title: Interference-Aware Channel Assignment for Maximizing Throughput in WMN

abstract:
  Wireless Mesh network (WMN) is dynamically self-organizing and
self-configured, with the nodes in the network automatically establishing an
ad-hoc network and maintaining the mesh connectivity. The ability to use
multiple-radios and multiple channels can be cashed to increase aggregate
throughput of wireless mesh network. Thus the efficient use of available
interfaces and channels without interference becomes the key factor. In this
paper we propose, interference aware clustered based channel assignment schemes
which minimizes the interference and increases throughput. In our proposed
scheme we have given priority to minimize interference from nearby mesh nodes
in interference range than maximizing channel diversity. We simulated our
proposed work using NS-3 and results show that our scheme improves network
performance than BFSCA and Distributed Greedy CA.


title:
Plasmonic Nano-Gap Tilings: Light-Concentrating Surfaces for Low-Loss
  Photonic Integration

abstract:
  Owing to their ability to concentrate light on nanometer scales, plasmonic
surface structures are ideally suited for on-chip functionalization with
nonlinear or gain materials. However, achieving a high effective quantum yield
across a surface not only requires strong light localization but also control
over losses. Here, we report on a particular class of tunable low-loss
metasurfaces featuring dense arrangements of nanometer sized focal points on a
photonic chip with an underlying waveguide channel. Guided within the plane,
the photonic wave evanescently couples to the nano-gaps, concentrating light in
a lattice of hot-spots. In studying the energy transfer between photonic and
plasmonic channels of single trimer molecules and triangular nano-gap tilings
in dependence on element size, we identify different regimes of operation. We
show that the product of field enhancement, propagation length and element size
is close-to-constant in both the radiative and subwavelength regimes, opening
pathways for device designs that combine high field enhancements with large
propagation lengths.


title: Rare K Decays: Present and perspectives with NA62

abstract:
  Rare kaon decays provide unique opportunity to test the Standard Model and
probe its possible extensions. The final result on the lepton universality test
by measuring the ratio R_K = G(K+- to e+- nu)/G(K+- to mu+- nu) is presented as
well as the status of the study of the rare decays K+- to pi+- gamma gamma and
K+ to e+ nu gamma. The primary goal of the NA62 experiment is the measurement
of the Br(K+ to pi+ nu anti-nu) decay with a precision of 10% in two years of
data taking. The detector setup together with the analysis technique is
described.


title:
Finiteness and liftability of postcritically finite quadratic morphisms
  in arbitrary characteristic

abstract:
  We show that for any integer n and any field k of characteristic different
from 2 there are at most finitely many isomorphism classes of quadratic
morphisms from the projective line over k to itself with a finite postcritical
orbit of size n. As a consequence we prove that every postcritically finite
quadratic morphism over a field of positive characteristic can be lifted to
characteristic zero with the same combinatorial type of postcritical orbit. The
associated profinite geometric monodromy group is therefore the same as in
characteristic zero, where it can be described explicitly by generators as a
self-similar group acting on a regular rooted binary tree.


title: Universal Soft Terms in the MSSM on D-branes

abstract:
  In Type II string vacua constructed from intersecting/magnetized D-branes,
the supersymmetry-breaking soft terms are genericaly non-universal. It is shown
that universal supersymmetry-breaking soft terms may arise in a realistic MSSM
constructed from intersecting/magnetized D-branes in Type II string theory. For
the case of dilaton-dominated supersymmetry-breaking, it is shown that the
universal scalar mass and trilinear coupling are fixed such that
$m_0=(1/2)m_{3/2}$ and $A_0 = - m_{1/2}$. In addition, soft terms where the
universal scalar mass $m_0$ is much larger than the universal gaugino mass
$m_{1/2}$ may be easily obtained within the model, corresponding to the Focus
Point (FP)/Hyperbolic Branch (HB) regions of the mSUGRA/CMSSM parameter space.
Finally, it is shown that the special dilaton and no-scale strict moduli
boundary conditions, which are well-known in heterotic string constructions,
may also be obtained.


title: Irreducible Induced Representations of Fell Bundle C*-Algebras

abstract:
  We give precise conditions under which irreducible representations associated
to stability groups induce to irreducible representations for Fell bundle
C*-algebras. This result generalizes an earlier result of Echterhoff and the
second author. Because the Fell bundle construction subsumes most other
examples of C*-algebras constructed from dynamical systems, our result
percolates down to many different constructions including the many flavors of
groupoid crossed products.


title: Determination of the CKM matrix elements |V(xb)|

abstract:
  We review the current status of |V(cb)|, |V(ub)| and |V(tb)|, the absolute
values of the matrix elements in the CKM third column.


title: Thermoelectric imaging of structural disorder in epitaxial graphene

abstract:
  Heat is a familiar form of energy transported from a hot side to a colder
side of an object, but not a notion associated with microscopic measurements of
electronic properties. A temperature difference within a material causes charge
carriers, electrons or holes, to diffuse along the temperature gradient
inducing a thermoelectric voltage. Here we show that local thermoelectric
measurements can yield high sensitivity imaging of structural disorder on the
atomic and nanometre scales. The thermopower measurement acts to amplify the
variations in the local density of states at the Fermi-level, giving high
differential contrast in thermoelectric signals. Using this imaging technique,
we uncovered point defects in the first layer of epitaxial graphene, which
generate soliton-like domain wall line patterns separating regions of the
different interlayer stacking of the second graphene layer.


title: Opportunities & Challenges In Automatic Speech Recognition

abstract:
  Automatic speech recognition enables a wide range of current and emerging
applications such as automatic transcription, multimedia content analysis, and
natural human-computer interfaces. This paper provides a glimpse of the
opportunities and challenges that parallelism provides for automatic speech
recognition and related application research from the point of view of speech
researchers. The increasing parallelism in computing platforms opens three
major possibilities for speech recognition systems: improving recognition
accuracy in non-ideal, everyday noisy environments; increasing recognition
throughput in batch processing of speech data; and reducing recognition latency
in realtime usage scenarios. This paper describes technical challenges,
approaches taken, and possible directions for future research to guide the
design of efficient parallel software and hardware infrastructures.


title: An Overview of Hindi Speech Recognition

abstract:
  In this age of information technology, information access in a convenient
manner has gained importance. Since speech is a primary mode of communication
among human beings, it is natural for people to expect to be able to carry out
spoken dialogue with computer. Speech recognition system permits ordinary
people to speak to the computer to retrieve information. It is desirable to
have a human computer dialogue in local language. Hindi being the most widely
spoken Language in India is the natural primary human language candidate for
human machine interaction. There are five pairs of vowels in Hindi languages;
one member is longer than the other one. This paper describes an overview of
speech recognition system that includes how speech is produced and the
properties and characteristics of Hindi Phoneme.


title: A quantum field theoretical detector model for probing the Unruh effect

abstract:
  We consider a particle detector model on 1+1-dimensional Minkowski space-time
that is accelerated by a constant external acceleration a. The detector is
coupled to a massless scalar test field. Due to the Unruh effect, this detector
becomes excited even in Minkowski vacuum with a probability proportional to a
thermal Bose-Einstein distribution at temperature T=a/2pi in the detector's
energy gap. This excitation is usually said to happen upon detection of a
Rindler quantum, which is defined by having positive frequency with respect to
the detector's proper time instead of inertial time. Using Unruh's fully
relativistic detector model, we show that the process involved is in fact
spontaneous excitation of the detector due to the interaction with the
accelerating background field E=ma. We explicitly solve the Klein-Gordon
equation in the presence of a constant background field E and use this result
to calculate the transition probability for the detector to become excited on
Minkowski vacuum. This transition probability agrees with the Unruh effect, but
is obtained without reverting to the concept of Rindler quantization.


title: Quantum entropy and exact 4d/5d connection

abstract:
  We consider the AdS_2/CFT_1 holographic correspondence near the horizon of
rotating five-dimensional black holes preserving four supersymmetries in N=2
supergravity. The bulk partition function is given by a functional integral
over string fields in AdS_2 and is related to the quantum entropy via the Sen's
proposal. Under certain assumptions we use the idea of equivariant localization
to non-rigid backgrounds and show that the path integral of off-shell
supergravity on the near horizon background, which is a circle fibration over
AdS_2xS^2, reduces to a finite dimensional integral over n_V+1 parameters C^A,
where n_V is the number of vector multiplets of the theory while the C^0 mode
corresponds to a normalizable fluctuation of the metric. The localization
solutions, which rely only on off-shell supersymmetry, become after a field
redefinition, the solutions found for localization of supergravity on
AdS_2xS^2. We compute the renormalized action on the localization locus and
show that, in the absence of higher derivative corrections, it agrees with the
four dimensional counterpart computed on AdS_2x S^2. These results together
with possible one-loop contributions can be used to establish an exact
connection between five and four dimensional quantum entropies.


title:
Unification scale vs. electroweak-triplet mass in the SU(5) + 24_F model
  at three loops

abstract:
  It was shown recently that the original SU(5) theory of Georgi and Glashow,
augmented with an adjoint fermionic multiplet 24_F, can be made compatible both
with neutrino masses and gauge coupling unification. In particular, the model
predicts that either electroweak-triplet states are light, within the reach of
the Large Hadron Collider (LHC), or proton decay will become accessible at the
next generation of megaton-scale facilities. In this paper, we present the
computation of the correlation function between the electroweak-triplet masses
and the unification scale at the next-to-next-to-leading-order (NNLO). Such an
accuracy on the theory side is necessary in order to settle the convergence of
the perturbative expansion and to match the experimental precision on the
determination of the electroweak gauge couplings at the Z-boson mass scale.


title:
The Relation Between Automorphism Group and Isometry Group of Randers
  Lie Groups

abstract:
  In this paper we consider simply connected Lie groups equipped with left
invariant Randers metrics which arise from left invariant Riemannian metrics
and left invariant vector fields. Then we study the intersection between
automorphism and isometry groups of these spaces. Finally it has shown that for
any left invariant vector field, in a special case, the Lie group admits a left
invariant Randers metric such that this intersection is a maximal compact
subgroup of the group of automorphisms with respect to which the considered
vector field is invariant.


title: Symplectic Connections Induced by the Chern Connection

abstract:
  Let $(M,\omega)$ be a symplectic manifold and $F$ be a Finsler structure on
$M$. In the present paper we define a lift of the symplectic two-form $\omega$
on the manifold $TM\backslash 0$, and find the conditions that the Chern
connection of the Finsler structure $F$ preserves this lift of $\omega$. In
this situation if $M$ admits a nowhere zero vector field then we have a
non-empty family of Fedosov structures on $M$.


title: Some Berwald Spaces of Non-positive flag Curvature

abstract:
  In this paper by using left invariant Riemannian metrics on some
3-dimensional Lie groups we construct some complete non-Riemannian Berwald
spaces of non-positive flag curvature and several families of geodesically
complete locally Minkowskian spaces of zero constant flag curvature.


title: Randers Metrics of Berwald type on 4-dimensional hypercomplex Lie groups

abstract:
  In the present paper we study Randers metics of Berwald type on simply
connected 4-dimensional real Lie groups admitting invariant hypercomplex
structure. On these spaces, the Randers metrics arising from invariant
hyper-Hermitian metrics are considered. Then we give explicit formulas for
computing flag curvature of these metrics. By this study we construct two
4-dimensional Berwald spaces, one of them has non-negative flag curvature and
the other one has non-positive flag curvature.


title: On the Geometry of some Para-hypercomplex Lie groups

abstract:
  In this paper, firstly we study some left invariant Riemannian metrics on
para-hypercomplex 4-dimensional Lie groups. In each Lie group, the Levi-Civita
connection and sectional curvature have been given explicitly. We also show
these spaces have constant negative scalar curvatures. Then by using left
invariant Riemannian metrics introduced in the first part, we construct some
left invariant Randers metrics of Berwald type. The explicit formulas for
computing flag curvature have been obtained in all cases. Some of these Finsler
Lie groups are of non-positive flag curvature.


title: On the flag curvature of invariant Randers metrics

abstract:
  In the present paper, the flag curvature of invariant Randers metrics on
homogeneous spaces and Lie groups is studied. We first give an explicit formula
for the flag curvature of invariant Randers metrics arising from invariant
Riemannian metrics on homogeneous spaces and, in special case, Lie groups. We
then study Randers metrics of constant positive flag curvature and complete
underlying Riemannian metric on Lie groups. Finally we give some properties of
those Lie groups which admit a left invariant non-Riemannian Randers metric of
Berwald type arising from a left invariant Riemannian metric and a left
invariant vector field.


title:
On the Randers metrics on two-step homogeneous nilmanifolds of dimension
  five

abstract:
  In this paper we study the geometry of simply connected two-step nilpotent
Lie groups of dimension five. We give the Levi-Civita connection, curvature
tensor, sectional and scalar curvatures of these spaces and show that they have
constant negative scalar curvature. Also we show that the only space which
admits left invariant Randers metric of Berwald type has three dimensional
center. In this case the explicit formula for computing flag curvature is
obtained and it is shown that flag curvature and sectional curvature have the
same sign.


title: On the curvature of invariant Kropina metrics

abstract:
  In the present article we compute the flag curvature of a special type of
invariant Kropina metrics on homogeneous spaces.


title:
On some hypercomplex 4-dimensional Lie groups of constant scalar
  curvature

abstract:
  In this paper we study sectional curvature of invariant hyper-Hermitian
metrics on simply connected 4-dimensional real Lie groups admitting invariant
hypercomplex structure. We give the Levi-Civita connections and explicit
formulas for computing sectional curvatures of these metrics and show that all
these spaces have constant scalar curvature. We also show that they are flat or
they have only non-negative or non-positive sectional curvature.


title: Induced Invariant Finsler Metrics on Quotient Groups

abstract:
  In this paper we show that every invariant Finsler metric on Lie group $G$,
induces an invariant Finsler metric on quotient group $G/H$ in the natural way,
where $H$ is a closed normal Lie subgroup of $G$.


title: Invariant Matsumoto metrics on homogeneous spaces

abstract:
  In this paper we consider invariant Matsumoto metrics which are induced by
invariant Riemannian metrics and invariant vector fields on homogeneous spaces
then we give the flag curvature formula of them. Also we study the special
cases of naturally reductive spaces and bi-invariant metrics. We end the
article by giving some examples of geodesically complete Matsumoto spaces.


title:
Flag curvature of invariant $(\alpha,\beta)$-metrics of type
  $\frac{(\alpha+\beta)^2}{\alpha}$

abstract:
  In this paper we study flag curvature of invariant $(\alpha,\beta)$-metrics
of the form $\frac{(\alpha+\beta)^2}{\alpha}$ on homogeneous spaces and Lie
groups. We give a formula for flag curvature of invariant metrics of the form
$F=\frac{(\alpha+\beta)^2}{\alpha}$ such that $\alpha$ is induced by an
invariant Riemannian metric $g$ on the homogeneous space and the Chern
connection of $F$ coincides to the Levi-Civita connection of $g$. Then some
conclusions in the cases of naturally reductive homogeneous spaces and Lie
groups are given.


title: Flag Curvature of Invariant Randers Metrics on Homogeneous Manifolds

abstract:
  In this article we review the recent results about the flag curvature of
invariant Randers metrics on homogeneous manifolds and by using a counter
example we show that the formula which obtained for the flag curvature of these
metrics is incorrect. Then we give an explicit formula for the flag curvature
of invariant Randers metrics on the naturally reductive homogeneous manifolds
$(G/H,g)$, where the Randers metric induced by the invariant Riemannian metric
$g$ and an invariant vector field $\tilde{X}$ which is parallel with $g$.


title: Major open problems in chaos theory and nonlinear dynamics

abstract:
  Nowadays, chaos theory and nonlinear dynamics lack research focuses. Here we
mention a few major open problems: 1. an effective description of chaos and
turbulence, 2. rough dependence on initial data, 3. arrow of time, 4. the
paradox of enrichment, 5. the paradox of pesticides, 6. the paradox of
plankton.

categories: nlin.CD math-ph math.AP math.MP physics.flu-dyn q-bio.PE


title:
TCloud: A Dynamic Framework and Policies for Access Control across
  Multiple Domains in Cloud Computing

abstract:
  In a cloud computing environment, access control policy is an effective means
of fortification cloud users and cloud resources services against security
infringements. Based on analysis of current cloud computing security
characteristics, the preamble of the concept of trust, role-based access
control policy, combined with the characteristics of the cloud computing
environment, there are multiple security management domains, so a new cross
domain framework is for access control is proposed which is based on trust. It
will establish and calculate the degree of trust in the single as well as
multiple domains. Role Based Access Control is used for the implementation of
the access control policies in a single domain environment with the
introduction of the trust concept. In multiple domains the access control will
be based on the conversion of roles. On the basis of trust, and role based
access control model, a new novel framework of flexible cross domain access
control framework is presented. The role assignment and conversion will take
place dynamically.


title: Face-Guarding Polyhedra

abstract:
  We study the Art Gallery Problem for face guards in polyhedral environments.
The problem can be informally stated as: how many (not necessarily convex)
windows should we place on the external walls of a dark building, in order to
completely illuminate its interior?
  We consider both closed and open face guards (i.e., faces with or without
their boundary), and we study several classes of polyhedra, including
orthogonal polyhedra, 4-oriented polyhedra, and 2-reflex orthostacks.
  We give upper and lower bounds on the minimum number of faces required to
guard the interior of a given polyhedron in each of these classes, in terms of
the total number of its faces, f. In several cases our bounds are tight: f/6
open face guards for orthogonal polyhedra and 2-reflex orthostacks, and f/4
open face guards for 4-oriented polyhedra. Additionally, for closed face guards
in 2-reflex orthostacks, we give a lower bound of (f+3)/9 and an upper bound of
(f+1)/7.
  Then we show that it is NP-hard to approximate the minimum number of (closed
or open) face guards within a factor of Omega(log f), even for polyhedra that
are orthogonal and simply connected. We also obtain the same hardness results
for polyhedral terrains.
  Along the way we discuss some applications, arguing that face guards are not
a reasonable model for guards patrolling on the surface of a polyhedron.


title: Entropy of non-equilibrium stationary measures of boundary driven TASEP

abstract:
  We examine the entropy of non-equilibrium stationary states of boundary
driven totally asymmetric simple exclusion processes. As a consequence, we
obtain that the Gibbs-Shannon entropy of the non equilibrium stationary state
converges to the Gibbs-Shannon entropy of the local equilibrium state.
Moreover, we prove that its fluctuations are Gaussian, except when the mean
displacement of particles produced by the bulk dynamics agrees with the
particle flux induced by the density reservoirs in the maximal phase regime.


title:
Semigroups, d-invariants and deformations of cuspidal singular points of
  plane curves

abstract:
  We apply Heegaard Floer homology to study deformations of singularities of
plane algebraic curves. Our main result provides an obstruction to the
existence of a deformation between two singularities. Generalizations include
the case of multiple singularities. The obstruction is formulated in terms of a
semicontinuity property for semigroups associated to the singularities.


title: The dynamics of domain wall Skyrmions

abstract:
  It has recently been shown that Skyrmions with a fixed size can exist in
theories without a Skyrme term, providing the Skyrmion is located on a domain
wall. Here we numerically compute domain wall Skyrmions of this type, in a
(2+1)-dimensional O(3) sigma model with a potential term. Moreover, we
investigate Skyrmion dynamics, to study both Skyrmion stability and the
scattering of multi-Skyrmions. We demonstrate that scattering events in which
both Skyrmions remain on the same domain wall are effectively one-dimensional,
and at low speeds are well-approximated by kink scattering in the integrable
sine-Gordon model. However, more exotic fully two-dimensional scatterings are
also presented, in which Skyrmions that are initially on different domain walls
emerge on the same domain wall.


title:
On the Distribution of Explosion Time of Stochastic Differential
  Equations

abstract:
  In this paper we use the It\^o's formula and comparison theorems to study the
blow-up in finite time of stochastic differential equations driven by a
Brownian motion. In particular, we obtain an extension of Osgood criterion,
which can be applied to some nonautonomous stochastic differential equations
with additive Wiener integral noise. In most cases we are able to provide with
a method to figure out the distribution of the explosion time of the involved
equation.


title:
A transient thermal cloak experimentally realized through a rescaled
  diffusion equation with anisotropic thermal diffusivity

abstract:
  Transformation optics originating from the invariance of Maxwell's equations
under the coordinate mapping has enabled the design and demonstration of many
fascinating electromagnetic devices that were unconceivable or deemed
impossible before [1-11], and has greatly contributed to the advancement of
modern electromagnetism and related researches assisted with the development of
metamaterials [12-15]. This technique has been extended to apply to other
partial differential equations governing different waves [16-23] or flux
[24-28], and has produced various novel functional devices such as acoustic
cloaks [20-23] and Schrodinger's 'hat' [19]. In the present work we applied the
coordinate transformation to the time-dependent heat diffusion equation [24-28]
and achieved the manipulation of the heat flux by predefined diffusion paths.
In the experiment we demonstrated a transient thermal cloaking device
engineered with thermal metamaterials and successfully hid a centimeter sized
strong 'scatter' (thermal disturber), i.e., a vacuum cavity. To facilitate
reliable fabrication we adopted the rescaled thermal diffusion equation for
various ingredient materials with nearly constant product of the density and
heat capacity, and took the anisotropic thermal diffusivities as the key
parameters for the design. Our results unambiguously show the practical
possibility to implement the complex transformed thermal media with high
accuracy and acquire some unprecedented thermodynamic functions, which we
believe will help to broaden the current research and pave a new way to
manipulate heat for novel device applications.


title: Interpolating Hodge-Tate and de Rham Periods

abstract:
  We study the interpolation of Hodge-Tate and de Rham periods over rigid
analytic families of Galois representations. Given a Galois representation on a
coherent locally free sheaf over a reduced rigid space and a bounded range of
weights, we obtain a stratification of this space by locally closed
subvarieties where the Hodge-Tate and bounded de Rham periods (within this
range) as well as 1-cocycles form locally free sheaves. We also prove strong
vanishing results for higher cohomology. Together, these results give a
simultaneous generalization of results of Sen, Kisin, and Berger-Colmez. The
main result has been applied by Varma in her proof of geometricity of
Harris-Lan-Taylor-Thorne Galois representations as well as in several works of
Ding.


title:
The stellar IMF determined in early-type galaxies from a non-degenerate
  set of optical line indices

abstract:
  We investigate the optical spectral region of spectra of 1000 stars searching
for IMF-sensitive features to constrain the low-mass end of the initial mass
function (IMF) slope in elliptical galaxies. We use the MILES stellar library
in the wavelength range [3500-7500] {\AA} to select indices that are sensitive
to cool dwarf stars and that only weakly depend on age and metallicity. In this
wavelength range, the response of a change in the effective temperature of the
cool red giant population is similar to the response of a change in the number
of dwarf stars in the galaxy. We investigate the degeneracy between IMF
variation and Teff,RGB and show that it is possible to break it with the new
IMF indicators defined here. In particular, we define a CaH1 index around
{\lambda}6380 {\AA} that arises purely from cool dwarfs, does not strongly
depend on age and is anti-correlated with [a/Fe]. This index allows the
determination of the the IMF slope when combined with TiO lines and age- and
metallicity-dependent features. The use of several indicators is crucial to
break degeneracies between IMF, age, abundance pattern and Teff of the RGB
population. We measure line-index strengths of the optical IMF indicators in
the SSP models and compare these with index strengths of the same features in
stacked SSDSS early-type galaxy spectra with varying velocity dispersions.
Using 10 different indicators, we find a clear trend of a steepening IMF with
increasing velocity dispersion described by the equation
x=(2.3+-0.1)*log{\sigma}200+(2.13+-0.15), where x is the IMF slope and
{\sigma}200 is the central stellar velocity dispersion measured in units of
200km/s. We compute the 'IMF mismatch' parameter as the ratio of stellar
mass-to-light ratio predicted from the x-{\sigma}200 relation to that inferred
from SSP models assuming a Salpeter IMF and find good agreement with
independent published results.


title: Decomposition de motifs abeliens

abstract:
  Let A be an abelian variety and let us fix a Weil cohomology with
coefficients in F. Let $H^1(A,F)$ be the first cohomology group of A and
$Lef(A) \subset GL(H^1(A,F))$ be its Lefschetz group, i.e. the sub-group of
$GL(H^1(A,F))$ of linear applications commuting with endomorphisms of A and
respecting the pairing induced by a polarization. We give an explicit
presentation of a $\mathbb{Q}$-algebra of correspondences $B_{i,r}$ such that
the cycle class map induces an isomorphism $cl_{|_{B_{i,r}}}: B_{i,r}
\otimes_{\mathbb{Q}} F \cong End_{Lef(A)}(H^i(A^r,F)).$ We also give relative
versions of this result. We deduce in particular the following fact. Let
$S=S_K(G,\mathcal{X})$ be a Shimura variety of PEL type. Then the functor
\textit{canonical construction} ${\mu: Rep (G) \rightarrow VHS(S(\mathbb{C}))}$
lifts to a functor ${\tilde{\mu}: Rep (G) \rightarrow CHM(S)_{\mathbb{Q}}}$,
where $CHM(S)_{\mathbb{Q}}$ is the category of relative Chow motives.


title:
Black-hole solution without curvature singularity and closed timelike
  curves

abstract:
  With a prescribed Coulomb-type energy-momentum tensor, an exact solution of
the Einstein field equations over a nonsimply-connected manifold is presented.
This spherically symmetric solution has neither curvature singularities nor
closed timelike curves. It can be considered to be a regularization of the
singular Reissner-Nordstrom solution over a simply-connected manifold.


title: Multi-q Pattern Classification of Polarization Curves

abstract:
  Several experimental measurements are expressed in the form of
one-dimensional profiles, for which there is a scarcity of methodologies able
to classify the pertinence of a given result to a specific group. The
polarization curves that evaluate the corrosion kinetics of electrodes in
corrosive media are an application where the behavior is chiefly analyzed from
profiles. Polarization curves are indeed a classic method to determine the
global kinetics of metallic electrodes, but the strong nonlinearity from
different metals and alloys can overlap and the discrimination becomes a
challenging problem. Moreover, even finding a typical curve from replicated
tests requires subjective judgement. In this paper we used the so-called
multi-q approach based on the Tsallis statistics in a classification engine to
separate multiple polarization curve profiles of two stainless steels. We
collected 48 experimental polarization curves in aqueous chloride medium of two
stainless steel types, with different resistance against localized corrosion.
Multi-q pattern analysis was then carried out on a wide potential range, from
cathodic up to anodic regions. An excellent classification rate was obtained,
at a success rate of 90%, 80%, and 83% for low (cathodic), high (anodic), and
both potential ranges, respectively, using only 2% of the original profile
data. These results show the potential of the proposed approach towards
efficient, robust, systematic and automatic classification of highly non-linear
profile curves.


title:
Intermediate-energy Coulomb excitation of 104Sn: Moderate E2 strength
  decrease approaching 100Sn

abstract:
  The reduced transition probability B(E2) of the first excited 2+ state in the
nucleus 104Sn was measured via Coulomb excitation in inverse kinematics at
intermediate energies. A value of 0.163(26) e^2b^2 was extracted from the
absolute cross-section on a Pb target, while the method itself was verified
with the stable 112Sn isotope. Our result deviates significantly from the
earlier reported value of 0.10(4) e^2b^2 and corresponds to a moderate decrease
of excitation strength relative to the almost constant values observed in the
proton-rich, even-A 106-114Sn isotopes. Present state-of-the-art shell-model
predictions, which include proton and neutron excitations across the N=Z=50
shell closures as well as standard polarization charges, underestimate the
experimental findings


title: Topology of moduli spaces of framed sheaves

abstract:
  In this paper we show that the moduli space of framed torsion-free sheaves on
a certain class of toric surfaces admits a filtrable Bialynicki-Birula
decomposition determined by the torus action. The irreducibility of this moduli
space follows immediately as a corollary. Moreover, using its filtrable
decomposition we show that the moduli space shares the same homotopy type of an
invariant proper compact subvariety having the same fixed points set. We start
our study from the moduli space of framed torsion-free sheaves on the
projective plane. Afterwards, we generalize the results to toric surfaces under
a few assumptions.


title: Seed particle formation for silicate dust condensation by SiO nucleation

abstract:
  Clustering of the abundant SiO molecules has been discussed as a possible
mechanism of seed particle formation for silicate dust in stellar outflows with
an oxygen rich element mixture. Previous results indicated that condensation
temperatures based on this mechanism are significant lower than what is really
observed. This negative result strongly rests on experimental data on vapour
pressure of SiO. New determinations show the older data to be seriously in
error. Here we aim to check with improved data the possibility that SiO
nucleation triggers the cosmic silicate dust formation. First we present
results of our measurements of vapour pressure of solid SiO. Second, we use the
improved vapour pressure data to re-calibrate existing experimental data on SiO
nucleation from the literature. Third, we use the re-calibrated data on SiO
nucleation in a simple model for dust-driven winds to determine the
condensation temperature of silicate in stellar outflows from AGB stars. We
show that onset of nucleation under circumstellar conditions commences at
higher temperature than was previously found. Calculated condensation
temperatures are still by about 100 K lower than observed ones, but this may be
due to the greenhouse effect of silicate dust temperatures. The assumption that
the onset of silicate dust formation in late-type M stars is triggered by
cluster formation of SiO is compatible with dust condensation temperatures
derived from IR observations.


title: Multiple isolation of nodes in recursive trees

abstract:
  We introduce the problem of isolating several nodes in random recursive trees
by successively removing random edges, and study the number of random cuts that
are necessary for the isolation. In particular, we analyze the number of random
cuts required to isolate $\ell$ selected nodes in a size-n random recursive
tree for three different selection rules, namely (i) isolating all of the nodes
labelled 1,2,...,$\ell$ (thus nodes located close to the root of the tree),
(ii) isolating all of the nodes labelled n+1-$\ell$,n+2-$\ell$,...,n (thus
nodes located at the fringe of the tree), and (iii) isolating $\ell$ nodes in
the tree, which are selected at random before starting the edge-removal
procedure. Using a generating functions approach we determine for these
selection rules the limiting distribution behavior of the number of cuts to
isolate all selected nodes, for $\ell$ fixed and n tending to infinity.


title: Embedded Weingarten tori in S^3

abstract:
  In this paper, we show that an embedded Weingarten surface in S^3 of genus 1
must be rotationally symmetric, provided that certain structure conditions are
satisfied. The argument involves an adaptation of our proof of Lawson's
Conjecture for minimal tori.


title:
Review of fluid flow and convective heat transfer within rotating disk
  cavities with impinging jet

abstract:
  Fluid flow and convective heat transfer in rotor-stator configurations, which
are of great importance in different engineering applications, are treated in
details in this review. The review focuses on convective heat transfer in
predominantly outward air flow in the rotor-stator geometries with and without
impinging jets and incorporates two main parts, namely,
experimental/theoretical methodologies and geometries/results. Experimental
methodologies include naphthalene sublimation techniques, steady state (thin
layer) and transient (thermochromic liquid crystals) thermal measurements,
thermocouples and infra-red cameras, hot-wire anemometry, laser Doppler and
particle image velocimetry, laser plane and smoke generator. Theoretical
approaches incorporate modern CFD computational tools (DNS, LES, RANS etc).
Geometries and results part being mentioned starting from simple to complex
elucidates cases of a free rotating disk, a single disk in the crossflow,
single jets impinging onto stationary and rotating disk, rotor-stator systems
without and with impinging single jets, as well as multiple jets. Conclusions
to the review outline perspectives of the further extension of the
investigations of different kinds of the rotor-stator systems and their
applications in engineering practice.


title:
From Agents to Continuous Change via Aesthetics: Learning Mechanics with
  Visual Agentbased Computational Modeling

abstract:
  Novice learners find motion as a continuous process of change challenging to
understand. In this paper, we present a pedagogical approach based on
agent-based, visual programming to address this issue. Integrating Logo
programming with curricular science has been shown to be challenging in
previous research on educational computing. We present a new Logo-based visual
programming language - ViMAP - and, a sequence of learning activities involving
programming and modeling, designed specifically to support seamless integration
between programming and learning kinematics. We describe relevant affordances
of the ViMAP environment that supports such seamless integration. We then
present ViMAP-MoMo, a curricular unit designed in ViMAP for modeling
kinematics, for a wide range of students (elementary - high school). The main
contribution of this paper is that we describe in detail a sequence of learning
activities in three phases, discuss the underlying rationale for each phase,
and where relevant, report results in the form of observational data from two
studies.


title: Non-simultaneous match-stick geometry

abstract:
  The purpose of this paper is to prove that every finite set of points that
can be constructed in the Euclidean plane by using a compass and a ruler can
also be constructed by using unitary match-sticks in a non-simultaneous way and
following to a certain set of postulates. To prove this, we will deduce the
Euclidean axioms for our defined set of axioms.


title: High-order Large Eddy Simulations of Confined Rotor-Stator Flows

abstract:
  In many engineering and industrial applications, the investigation of
rotating turbulent flow is of great interest. In rotor-stator cavities, the
centrifugal and Coriolis forces have a strong influence on the turbulence by
producing a secondary flow in the meridian plane composed of two thin boundary
layers along the disks separated by a non-viscous geostrophic core. Most
numerical simulations have been performed using RANS and URANS modelling, and
very few investigations have been performed using LES. This paper reports on
quantitative comparisons of two high-order LES methods to predict a turbulent
rotor-stator flow at the rotational Reynolds number Re=400000. The classical
dynamic Smagorinsky model for the subgrid-scale stress (Germano et al., Phys
Fluids A 3(7):1760-1765, 1991) is compared to a spectral vanishing viscosity
technique (S\'everac & Serre, J Comp Phys 226(2):1234-1255, 2007). Numerical
results include both instantaneous data and postprocessed statistics. The
results show that both LES methods are able to accurately describe the unsteady
flow structures and to satisfactorily predict mean velocities as well as
Reynolds stress tensor components. A slight advantage is given to the spectral
SVV approach in terms of accuracy and CPU cost. The strong improvements
obtained in the present results with respect to RANS results confirm that LES
is the appropriate level of modelling for flows in which fully turbulent and
transition regimes are involved.


title:
Five-Dimensional Maximally Supersymmetric Yang-Mills in Supergravity
  Backgrounds

abstract:
  We determine the action for five-dimensional maximally supersymmetric
Yang-Mills in off-shell supergravity backgrounds. The resulting theory contains
novel five-dimensional BF type couplings as well as cubic scalar interactions
which vanish in flat space.


title: Landau-Zener and Rabi oscillations in the spin-dependent conductance

abstract:
  We describe the spin-dependent quantum conductance in a wire where a magnetic
field is spatially modulated. The change in direction and intensity of the
magnetic field acts as a perturbation that mixes spin projections. This is
exemplified by a ferromagnetic nanowire. There the local field varies smoothly
its direction generating a domain wall (DW) as described by the well-known
Cabrera-Falicov model. Here, we generalize this model to include also a
strength modulation. We identify two striking diabatic regimes that appear when
such magnetic inhogeneity occurs. 1) If the field strength at the DW is weak
enough, the local Zeeman energies result in an avoided crossing. Thus, the
spin-flip probability follows the Landau-Zener formula. 2) For strong fields,
the spin-dependent conductance shows oscillations as a function of the DW
width. We interpret them in terms of Rabi oscillations. Time and length scales
obtained from this simplified view show an excellent agreement with the exact
dynamical solution of the spin-dependent transport. These results remain valid
for other situations involving modulated magnetic structures and thus they open
new prospects for the use of quantum interferences in spin-based devices.
  This paper is dedicated to the memory of the lifelong collaborator Patricia
Rebeca Levstein.


title: Multifractality at Anderson transitions with Coulomb interaction

abstract:
  We explore mesoscopic fluctuations and correlations of the local density of
states (LDOS) near localization transition in a disordered interacting
electronic system. It is shown that the LDOS multifractality survives in the
presence of Coulomb interaction. We calculate the spectrum of multifractal
dimensions in $2+\epsilon$ spatial dimensions and show that it differs from
that in the absence of interaction. The multifractal character of fluctuations
and correlations of the LDOS can be studied experimentally by scanning
tunneling microscopy of two-dimensional and three-dimensional disordered
structures.


title:
Finding a needle in an exponential haystack: Discrete RRT for
  exploration of implicit roadmaps in multi-robot motion planning

abstract:
  We present a sampling-based framework for multi-robot motion planning which
combines an implicit representation of a roadmap with a novel approach for
pathfinding in geometrically embedded graphs tailored for our setting. Our
pathfinding algorithm, discrete-RRT (dRRT), is an adaptation of the celebrated
RRT algorithm for the discrete case of a graph, and it enables a rapid
exploration of the high-dimensional configuration space by carefully walking
through an implicit representation of a tensor product of roadmaps for the
individual robots. We demonstrate our approach experimentally on scenarios of
up to 60 degrees of freedom where our algorithm is faster by a factor of at
least ten when compared to existing algorithms that we are aware of.


title: Brouwer Fixed Point Theorem in (L^0)^d

abstract:
  The classical Brouwer fixed point theorem states that in R^d every continuous
function from a convex, compact set on itself has a fixed point. For an
arbitrary probability space, let L^0 = L^0 (\Omega, A,P) be the set of random
variables. We consider (L^0)^d as an L^0-module and show that local,
sequentially continuous functions on closed and bounded subsets have a fixed
point which is measurable by construction.


title: Complex Chern-Simons from M5-branes on the Squashed Three-Sphere

abstract:
  We derive an equivalence between the (2,0) superconformal M5-brane field
theory dimensionally reduced on a squashed three-sphere, and Chern-Simons
theory with complex gauge group. In the reduction, the massless fermions obtain
an action which is second order in derivatives and are reinterpreted as ghosts
for gauge fixing the emergent non-compact gauge symmetry. A squashing parameter
in the geometry controls the imaginary part of the complex Chern-Simons level.


title:
Verifying Fixed-Point Digital Filters using SMT-Based Bounded Model
  Checking

abstract:
  The implementation of digital filters in processors based on fixed-point
arithmetic can lead to problems related to the finite word-length. In
particular, the processing of signals in such filters can produce overflows and
unwanted noise caused by quantization and round off effect during the
accumulative addition and multiplication operations. In this paper, we describe
a new approach to verify digital filters using an off-the-shelf bounded model
checker called ESBMC, which supports full C/C++ and is based on satisfiability
modulo theories solvers. In particular, we are able to verify the occurrence of
overflows, limit cycles, and time constraints based on a discrete-time model
implemented in C. The experiments show that the proposed approach can be used
to verify potential problems in fixed-point implementation of digital filters
and it can thus be effective in finding realistic design errors.


title:
Large Scale Structure. The seventies & Forty years later: From Clusters
  to Clusters

abstract:
  I describe the beginning, ~ 1970, of the spectroscopic redshift surveys and
the discovery of the superclusters filamentary structures and voids. This
changed the view of the distribution of luminous light from the way we knew it
at the end of the sixties, a uniform distribution of galaxies with clusters
superimposed, and the way we understood it during the seventies, clusters
imbedded in filamentary structures. We planned in brief to understand the
distribution of galaxies and the effect of their environment since to learn
about the formation and evolution of the Universe, we need to know first how it
is now. The very large surveys, first among these the CfA, started in the
eighties thanks also to dedicated telescopes; during that period, the
distribution of mass on large scales was also measured. A next step, in
addition to the many and deep galaxies survey that are going on, could be a
deep cluster survey to detect distant clusters, improve the accuracy of the
clusters physical parameters as a function of redshift and have a more robust
probe for Cosmology.


title: Herschel Observations of Gas and Dust in the Unusual 49 Ceti Debris Disk

abstract:
  We present far-IR/sub-mm imaging and spectroscopy of 49 Ceti, an unusual
circumstellar disk around a nearby young A1V star. The system is famous for
showing the dust properties of a debris disk, but the gas properties of a
low-mass protoplanetary disk. The data were acquired with the Herschel Space
Observatory PACS and SPIRE instruments, largely as part of the "Gas in
Protoplanetary Systems" (GASPS) Open Time Key Programme. Disk dust emission is
detected in images at 70, 160, 250, 350, and 500 \mu m; 49 Cet is significantly
extended in the 70 \mu m image, spatially resolving the outer dust disk for the
first time. Spectra covering small wavelength ranges centered on eight atomic
and molecular emission lines were obtained, including [OI] 63 \mu m and [CII]
158 \mu m. The CII line was detected at the 5\sigma\ level - the first
detection of atomic emission from the disk. No other emission lines were seen,
despite the fact that the OI line is the brightest one observed in Herschel
protoplanetary disk spectra (Meeus et al. 2012; Dent et al. 2013). We present
an estimate of the amount of circumstellar atomic gas implied by the CII
emission. The new far-IR/sub-mm data fills in a large gap in the previous
spectral energy distribution (SED) of 49 Cet. A simple model of the new SED
confirms the two-component structure of the disk: warm inner dust and cold
outer dust that produces most of the observed excess. Finally, we discuss
preliminary thermochemical modeling of the 49 Cet gas/dust disk and our
attempts to match several observational results simultaneously. Although we are
not yet successful in doing so, our investigations shed light on the
evolutionary status of the 49 Cet gas, which might not be primordial gas but
rather secondary gas coming from comets.


title:
Particle correlations and evidence for dark state condensation in a cold
  dipolar exciton fluid

abstract:
  In this paper we show experimental evidence of a few correlation regimes of a
cold dipolar exciton fluid, created optically in a semiconductor bilayer
heterostructure. In the higher temperature regime, the average interaction
energy between the particles shows a surprising temperature dependence which is
an evidence for correlations beyond the mean field model. At a lower
temperature, there is a sharp increase in the interaction energy of optically
active excitons, accompanied by a strong reduction in their apparent
population. This is an evidence for a sharp macroscopic transition to a dark
state as was suggested theoretically.


title: From quasimodes to resonances: exponentially decaying perturbations

abstract:
  We consider self-adjoint operators of black-box type which are exponentially
close to the free Laplacian near infinity, and prove an exponential bound for
the resolvent in a strip away from resonances. Here the resonances are defined
as poles of the meromorphic continuation of the resolvent between appropriate
exponentially weighted spaces. We then use a local version of the maximum
principle to prove that any cluster of real quasimodes generates at least as
many resonances, with multiplicity, rapidly converging to the quasimodes.


title: Major arcs for Goldbach's problem

abstract:
  The ternary Goldbach conjecture states that every odd number $n\geq 7$ is the
sum of three primes. The estimation of the Fourier series $\sum_{p\leq x}
e(\alpha p)$ and related sums has been central to the study of the problem
since Hardy and Littlewood (1923). Here we show how to estimate such Fourier
series for $\alpha$ in the so-called major arcs, i.e., for $\alpha$ close to a
rational of small denominator. This is part of the author's proof of the
ternary Goldbach conjecture. In contrast to most previous work on the subject,
we will rely on a finite verification of the Generalized Riemann Hypothesis up
to a bounded conductor and bounded height, rather than on zero-free regions. We
apply a rigorous verification due to D. Platt; the results we obtain are both
rigorous and unconditional. The main point of the paper will be the development
of estimates on parabolic cylinder functions that make it possible to use
smoothing functions based on the Gaussian. The generality of our explicit
formulas will allow us to work with a wide variety of such functions.


title:
Stability and bifurcations for dissipative polynomial automorphisms of
  C^2

abstract:
  We study stability and bifurcations in holomorphic families of polynomial
automorphisms of C^2. We say that such a family is weakly stable over some
parameter domain if periodic orbits do not bifurcate there. We first show that
this defines a meaningful notion of stability, which parallels in many ways the
classical notion of J-stability in one-dimensional dynamics. In the second part
of the paper, we prove that under an assumption of moderate dissipativity, the
parameters displaying homoclinic tangencies are dense in the bifurcation locus.
This confirms one of Palis' Conjectures in the complex setting. The proof
relies on the formalism of semi-parabolic bifurcation and the construction of
"critical points" in semi-parabolic basins (which makes use of the classical
Denjoy-Carleman-Ahlfors and Wiman Theorems).


title:
Degree 3 Cohomological Invariants of Groups that are Neither Simply
  Connected nor Adjoint

abstract:
  In a recent paper A. Merkurjev constructed an exact sequence which includes
as one of the terms the group of degree 3 normalized cohomological invariants
of a semisimple algebraic group G, greatly extending results of M. Rost for
simply connected quasi-simple groups. Furthermore, in the aforementioned paper,
Merkurjev uses his exact sequence to determine the groups of invariants for all
semisimple adjoint groups of inner type. The goal of this paper is to use
Merkurjev's sequence to compute the group of invariants for the remaining split
cases, namely groups of types A and D that are neither simply connected nor
adjoint. This description not only demonstrates the existence of many
previously unstudied invariants but also allows us to extend several known
results which relate these invariants to the Rost invariant and algebras with
involution.


title: A Dark Sector Extension of the Almost-Commutative Standard Model

abstract:
  We consider an extension of the Standard Model within the frame work of
Noncommutative Geometry. The model is based on an older model [St09] which
extends the Standard Model by new fermions, a new U(1)-gauge group and,
crucially, a new scalar field which couples to the Higgs field. This new scalar
field allows to lower the mass of the Higgs mass from ~170 GeV, as predicted by
the Spectral Action for the Standard Model, to a value of 120-130 GeV. The
short-coming of the previous model lay in its inability to meet all the
constraints on the gauge couplings implied by the Spectral Action. These
shortcomings are cured in the present model which also features a "dark sector"
containing fermions and scalar particles.


title:
Investigation of cation self-diffusion mechanisms in UO2+-x using
  molecular dynamics

abstract:
  This article is devoted to investigation of cation self-diffusion mechanisms,
taking place in UO2, UO2+x, and UO2-x crystals simulated under periodic (PBC)
and isolated (IBC) boundary conditions using the method of molecular dynamics
in the approximation of rigid ions and pair interactions. It is shown that
under PBC the cations diffuse via an exchange mechanism (with the formation of
Frenkel defects) with activation energy of 15-22 eV, while under IBC there is
competition between the exchange and vacancy (via Schottky defects) diffusion
mechanisms, which give the effective activation energy of 11-13 eV near the
melting temperature of the simulated UO2.00 nanocrystals. Vacancy diffusion
with lower activation energy of 6-7 eV was dominant in the non-stoichiometric
crystals UO2.10, UO2.15 and UO1.85. Observations showed that a cation vacancy
is accompanied by different number of anion vacancies depending on the
deviation from stoichiometry: no vacancies in UO2.15, single vacancy in UO2.00
and four vacancies in UO1.85. The corresponding law of mass action formulas
derived within the Lidiard-Matzke model allowed explaining the obtained
activation energies and predicting a change in the activation energy within the
temperature range of the superionic phase transition. The diffusion of cations
on the surface of nanocrystals had activation energy of 3.1-3.6 eV.


title:
Inapproximability for Antiferromagnetic Spin Systems in the Tree
  Non-Uniqueness Region

abstract:
  A remarkable connection has been established for antiferromagnetic 2-spin
systems, including the Ising and hard-core models, showing that the
computational complexity of approximating the partition function for graphs
with maximum degree D undergoes a phase transition that coincides with the
statistical physics uniqueness/non-uniqueness phase transition on the infinite
D-regular tree. Despite this clear picture for 2-spin systems, there is little
known for multi-spin systems. We present the first analog of the above
inapproximability results for multi-spin systems.
  The main difficulty in previous inapproximability results was analyzing the
behavior of the model on random D-regular bipartite graphs, which served as the
gadget in the reduction. To this end one needs to understand the moments of the
partition function. Our key contribution is connecting: (i) induced matrix
norms, (ii) maxima of the expectation of the partition function, and (iii)
attractive fixed points of the associated tree recursions (belief propagation).
The view through matrix norms allows a simple and generic analysis of the
second moment for any spin system on random D-regular bipartite graphs. This
yields concentration results for any spin system in which one can analyze the
maxima of the first moment. The connection to fixed points of the tree
recursions enables an analysis of the maxima of the first moment for specific
models of interest.
  For k-colorings we prove that for even k, in the tree non-uniqueness region
(which corresponds to k<D) it is NP-hard, unless NP=RP, to approximate the
number of colorings for triangle-free D-regular graphs. Our proof extends to
the antiferromagnetic Potts model, and, in fact, to every antiferromagnetic
model under a mild condition.


title:
Dynamics and physical interpretation of quasi-stationary states in
  systems with long-range interactions

abstract:
  Although the Vlasov equation is used as a good approximation for a
sufficiently large $N$, Braun and Hepp have showed that the time evolution of
the one particle distribution function of a $N$ particle classical Hamiltonian
system with long range interactions satisfies the Vlasov equation in the limit
of infinite $N$. Here we rederive this result using a different approach
allowing a discussion of the role of inter-particle correlations on the system
dynamics. Otherwise for finite N collisional corrections must be introduced.
This has allowed the a quite comprehensive study of the Quasi Stationary States
(QSS) but many aspects of the physical interpretations of these states remain
unclear. In this paper a proper definition of timescale for long time evolution
is discussed and several numerical results are presented, for different values
of $N$. Previous reports indicates that the lifetimes of the QSS scale as
$N^{1.7}$ or even the system properties scales with $\exp(N)$. However,
preliminary results presented here shows indicates that time scale goes as
$N^2$ for a different type of initial condition. We also discuss how the form
of the inter-particle potential determines the convergence of the $N$-particle
dynamics to the Vlasov equation. The results are obtained in the context of
following models: the Hamiltonian Mean Field, the Self Gravitating Ring Model,
and a 2-D Systems of Gravitating Particles. We have also provided information
of the validity of the Vlasov equation for finite $N$, i. e.\ how the dynamics
converges to the mean-field (Vlasov) description as $N$ increases and how
inter-particle correlations arise.


title:
Charge transport in lithium peroxide: Relevance for rechargeable
  metal-air batteries

abstract:
  The mechanisms and efficiency of charge transport in lithium peroxide (Li2O2)
are key factors in understanding the performance of non-aqueous Li-air
batteries. Towards revealing these mechanisms, here we use first-principles
calculations to predict the concentrations and mobilities of charge carriers
and intrinsic defects in Li2O2 as a function of cell voltage. Our calculations
reveal that changes in the charge state of O2 dimers controls the defect
chemistry and conductivity of Li2O2. Negative lithium vacancies (missing Li+)
and small hole polarons are identified as the dominant charge carriers. The
electronic conductivity associated with polaron hopping (5 x 10-20 S/cm) is
comparable to the ionic conductivity arising from the migration of Li-ions (4 x
10-19 S/cm), suggesting that charge transport in Li2O2 occurs through a mixture
of ionic and polaronic contributions. These data indicate that the bulk regions
of crystalline Li2O2 are insulating, with appreciable charge transport
occurring only at moderately high charging potentials that drive partial
delithiation. The implications of limited charge transport on discharge and
recharge mechanisms are discussed, and a two-stage charging process linking
charge transport, discharge product morphology, and overpotentials is
described. We conclude that achieving both high discharge capacities and
efficient charging will depend upon access to alternative mechanisms that
bypass bulk charge transport. More generally, we describe how the presence of a
species that can change charge state - e.g., O2 dimers in alkaline metal-based
peroxides - may impact rechargeability in metal-air batteries.


title:
Do leptoquarks manifest themselves in ultra-high energy neutrino
  interactions?

abstract:
  It is assumed that neutrino-nucleon scattering at ultra-high energies
effectively proceeds through excitations of leptoquarks in neutrino-quark
subprocesses. This approach reproduces the behavior of the energy dependence of
the ultra-high energy neutrino-nucleon scattering cross sections and allows to
estimate masses as well as the decay widths of the involved leptoquarks. For
instance, this leads to the leptoquark mass $1353\pm230$ GeV in a way
independent on the leptoquark quantum numbers. The discovery potential of the
LHC for the leptoquarks is evaluated.


title: Character and dimension formulae for queer Lie superalgebra

abstract:
  Closed formulae are constructed for the characters and dimensions of the
finite dimensional simple modules of the queer Lie superalgebra q(n). This is
achieved by refining Brundan's algorithm for computing simple q(n)-characters.


title: Cloaking and Magnifying Using Radial Anisotropy

abstract:
  This paper studies the electrostatic responses of a polarly radially
anisotropic cylinder and a spherically radially anisotropic sphere. For both
geometries, the permittivity components differ from each other in the radial
and tangential directions. We show that choosing the ratio between these
components in a certain way, these rather simple structures can be used in
cloaking dielectric inclusions with arbitrary permittivity and shape in the
quasi-static limit. For an ideal cloak, the contrast between the permittivity
components has to tend to infinity. However, only positive permittivity values
are required and a notable cloaking effect can already be observed with
relatively moderate permittivity contrasts. Furthermore, we show that the
polarly anisotropic cylindrical shell has a complementary capability of
magnifying the response of an inner cylinder.


title:
The Earth's Frame Dragging via Laser Ranged Satellites: a Response to
  'Some considerations on the present-day results for the detection of
  frame-dragging after the final outcome of GP-B' by L. Iorio [arXiv:1105.4145]

abstract:
  In this note, we reply to the preceding paper by Iorio: "Some considerations
on the present-day results for the detection of frame-dragging after the final
outcome of GP-B, Europhysics Letters", we address criticisms regarding the
Lense-Thirring frame-dragging experiment results obtained from the laser
ranging to the two LAGEOS satellites.


title: Charge screening by thin-shells in a 2+1-dimensional regular black hole

abstract:
  We consider a particular Bardeen black hole in 2+1-dimensions. The black hole
is sourced by a radial electric field in non-linear electrodynamics (NED). The
solution is obtained anew by the alternative Hamiltonian formalism. For
$r\rightarrow \infty $ it asymptotes to the charged BTZ black hole. It is shown
that by inserting a charged, thin-shell (or ring) the charge of the regular
black hole can be screened from the external world.


title: Protecting SQUID metamaterials against stray magnetic field

abstract:
  Using superconducting quantum interference devices (SQUIDs) as basic,
low-loss elements of thin-film metamaterials has one main advantage: Their
resonance frequency is easily tunable by applying a weak magnetic field. The
downside, however, is a strong sensitivity to stray and inhomogeneous magnetic
fields. In this work, we demonstrate that even small magnetic fields from
electronic components destroy the collective, resonant behaviour of the SQUID
metamaterial. We also show how the effect of these fields can be minimized. As
a first step, magnetic shielding decreases any initially present fields
including the earth's magnetic field. However, further measures like
improvements in the sample geometry have to be taken to avoid the trapping of
Abrikosov vortices.


title:
Dissipation and Entropy Production in Deterministic Heat Conduction of
  Quasi-one-dimensional Systems

abstract:
  We explore the consequences of a deterministic microscopic
thermostat-reservoir contact mechanism. With different temperature reservoirs
at each end of a two-dimensional system, a heat current is produced and the
system has an anomalous thermal conductivity. The microscopic form for the
local heat flux vector is derived and both the kinetic and potential
contributions are calculated. The total heat flux vector is shown to satisfy
the continuity equation. The properties of this nonequilibrium steady state are
studied as a function of system size and temperature gradient identifying key
scaling relations for the local fluid properties and separating bulk and
boundary effects. The local entropy density calculated from the local
equilibrium distribution is shown to be a very good approximation to the
entropy density calculated directly from velocity distribution even for systems
that are far from equilibrium. The dissipation and kinetic entropy production
and flux are compared quantitatively and the differing mechanisms discussed
within the BGY approximation. For equal temperature reservoirs the entropy
production near the reservoir walls is shown to be proportional to the local
phase space contraction calculated from the tangent space dynamics. However,
for unequal temperatures, the connection between local entropy production and
local phase space contraction is more complicated.


title:
Broad Band X-Ray Spectra of Two Low-luminosity Active Galactic Nuclei
  NGC 1566 and NGC 4941

abstract:
  We report the first broad band X-ray spectra of the low luminosity active
galactic nuclei (LLAGN) NGC 1566 (type 1.5) and NGC 4941 (type 2) observed with
Suzaku and Swift/BAT covering the 0.5-195 keV band. Both targets have hard
X-ray luminosities of ~ 10^{41-42} ergs/s in the 15-55 keV band. The spectra of
the nucleus are well reproduced by a sum of partially or fully covered
transmitted emission and its reflection from the accretion disk, reprocessed
emission from the torus accompanied by a strong narrow iron-K\alpha line, and a
scattered component (for NGC 4941). We do not significantly detect a broad
iron-K\alpha line from the inner accretion disk in both targets, and obtain an
upper limit on the corresponding solid angle of \Omega/2\pi < 0.3 in NGC 1566.
The reflection strength from the torus is moderate, \Omega/2\pi
=0.45^{+0.13}_{-0.10} in NGC 1566 and \Omega/2\pi =0.64^{+0.69}_{-0.27} in NGC
4941. Comparison of the equivalent width of the narrow iron-K\alpha line with a
model prediction based on a simple torus geometry constrains its half-opening
angle to be \theta_oa ~ 60-70 degree in NGC 4941. These results agree with the
obscured AGN fraction obtained from hard X-ray and mid-infrared selected
samples at similar luminosities. Our results support the implication that the
averaged covering fraction of AGN tori is peaked at L 10^{42-43} ergs/s but
decreases toward lower luminosities.