title: F{\o}lner sequences in operator theory and operator algebras

abstract:
  The present article is a review of recent developments concerning the notion
of F{\o}lner sequences both in operator theory and operator algebras. We also
give a new direct proof that any essentially normal operator has an increasing
F{\o}lner sequence $\{P_n\}$ of non-zero finite rank projections that strongly
converges to 1. The proof is based on Brown-Douglas-Fillmore theory. We use
F{\o}lner sequences to analyze the class of finite operators introduced by
Williams in 1970. In the second part of this article we examine a procedure of
approximating any amenable trace on a unital and separable C*-algebra by
tracial states $\mathrm{Tr}(\cdot P_n)/\mathrm{Tr}(P_n)$ corresponding to a
F{\o}lner sequence and apply this method to improve spectral approximation
results due to Arveson and B\'edos. The article concludes with the analysis of
C*-algebras admitting a non-degenerate representation which has a F{\o}lner
sequence or, equivalently, an amenable trace. We give an abstract
characterization of these algebras in terms of unital completely positive maps
and define F{\o}lner C*-algebras as those unital separable C*-algebras that
satisfy these equivalent conditions. This is analogous to Voiculescu's abstract
characterization of quasidiagonal C*-algebras.


title:
Charged lepton correction to tribimaximal lepton mixing and its
  implications to neutrino phenomenology

abstract:
  The recent results from Daya Bay and RENO reactor neutrino experiments have
firmly established that the smallest reactor mixing angle $\theta_{13}$ is
non-vanishing at the $5 \sigma$ level, with a relatively large value, i.e.,
$\theta_{13}\approx 9^{\circ}$. Using the fact that the neutrino mixing matrix
can be represented as $V_{\rm PMNS}=U_l^{\dagger} U_{\nu} P_\nu$, where $U_l$
and $U_\nu$ result from the diagonalization of the charged lepton and neutrino
mass matrices and $P_\nu$ is a diagonal matrix containing the Majorana phases
and assuming the tri-bimaximal form for $U_\nu$, we investigate the possibility
of accounting for the large reactor mixing angle due to the corrections of the
charged lepton mixing matrix. The form of $U_{l}$ is assumed to be that of CKM
mixing matrix of the quark sector. We find that with this modification it is
possible to accommodate the large observed reactor mixing angle $\theta_{13}$.
We also study the implications of such corrections on the other
phenomenological observables.


title: Quantum Hall effect in graphene with superconducting electrodes

abstract:
  We have realized an integer quantum Hall system with superconducting contacts
by connecting graphene to niobium electrodes. Below their upper critical field
of 4 tesla, an integer quantum Hall effect coexists with superconductivity in
the leads, but with a plateau conductance that is larger than in the normal
state. We ascribe this enhanced quantum Hall plateau conductance to Andreev
processes at the graphene-superconductor interface leading to the formation of
so-called Andreev edge-states. The enhancement depends strongly on the
filling-factor, and is less pronounced on the first plateau, due to the special
nature of the zero energy Landau level in monolayer graphene.


title: Initial trace of solutions of semilinear heat equation with absorption

abstract:
  We study the initial trace problem for positive solutions of semilinear heat
equations with strong absorption. We show that in general this initial trace is
an outer regular Borel measure. We emphasize in particular the case where $u$
satisfies (E) $\partial_t u-\Delta u+t^\alpha |u|^{q-1}u=0$, with $q>1$ and
$\alpha>-1$ and prove that in the subcritical case $1


title:
Quasiparticle mass enhancement close to the quantum critical point in
  BaFe$_2$(As$_{1-x}$P$_x$)$_2$

abstract:
  We report a combined study of the specific heat and de Haas-van Alphen effect
in the iron-pnictide superconductor BaFe$_2$(As$_{1-x}$P$_x$)$_2$. Our data
when combined with results for the magnetic penetration depth give compelling
evidence for the existence of a quantum critical point (QCP) close to $x=0.30$
which affects the majority of the Fermi surface by enhancing the quasiparticle
mass. The results show that the sharp peak in the inverse superfluid density
seen in this system results from a strong increase in the quasiparticle mass at
the QCP.


title: Compactifying Exchange Graphs I: Annuli and Tubes

abstract:
  We introduce the notion of an \emph{asymptotic triangulation} of the annulus.
We show that asymptotic triangulations can be mutated as the usual
triangulations and describe their exchange graph. Viewing asymptotic
triangulations as limits of triangulations under the action of the mapping
class group, we compactify the exchange graph of the triangulations of the
annulus. The cases of tubes are also considered.


title: Investigation of charge states and multiferroicity in Fe-doped h-YMnO3

abstract:
  Polycrystalline YMn1-xFexO3 (YMFO_x) (0 <= x <= 0.1) compounds have been
prepared in single phase and characterized by synchrotron X-ray diffraction,
X-ray absorption near edge spectroscopy, magnetization, and dielectric
measurements. Iron-substitution in hexagonal YMnO3 causes intra-lattice changes
exceeding those of the lattice cell. XANES provide mixed-valence Mn3+/Mn4+ and
Fe4+ charge states in these manganites, consistent with the observed decrease
of the effective magnetic moment with Fe-doping. Magnetization M(T) evidence
antiferromagnetic (AFM) ordering of the specimens with little weak
ferromagnetism, and the metrices of exchange interaction suppress with
Fe-doping, attributed to the lengthening of the Mn-O planar bond lengths.
Dielectric {\epsilon}'(T) results showing highly doping-dependent anomaly at
T_N indicate linear magneto-electric coupling.


title: On the Cohomological Hall Algebra of Dynkin quivers

abstract:
  Consider the Cohomological Hall Algebra as defined by Kontsevich and
Soibelman, associated with a Dynkin quiver. We reinterpret the geometry behind
the multiplication map in the COHA, and give an iterated residue formula for
it. We show natural subalgebras whose product is the whole COHA (except in the
$E_8$ case). The dimension count version of this statement is an identity for
quantum dilogarithm series, first proved by Reineke. We also show that natural
structure constants of the COHA are universal polynomials representing
degeneracy loci, a.k.a. quiver polynomials.


title: The Second-Order Coding Rate of the MIMO Rayleigh Block-Fading Channel

abstract:
  The second-order coding rate of the multiple-input multiple-output (MIMO)
quasi-static Rayleigh fading channel is studied. We tackle this problem via an
information-spectrum approach and statistical bounds based on recent random
matrix theory techniques. We derive a central limit theorem (CLT) to analyze
the information density in the regime where the block-length n and the number
of transmit and receive antennas K and N, respectively, grow simultaneously
large. This result leads to the characterization of closed-form upper and lower
bounds on the optimal average error probability when the coding rate is within
O((nK)^-1/2) of the asymptotic capacity.


title: Muon diffusion and electronic magnetism in Y$_2$Ti$_2$O$_7$

abstract:
  We report a $\mu$SR study in a Y$_2$Ti$_2$O$_7$ single crystal. We observe
slow local field fluctuations at low temperature which become faster as the
temperature is increased. Our analysis suggests that muon diffusion is present
in this system and becomes small below 40 K and therefore incoherent. A
surprisingly strong electronic magnetic signal is observed with features
typical for muons thermally diffusing towards magnetic traps below $\approx
100$ K and released from them above this temperature. We attribute the traps to
Ti$^{3+}$ defects in the diluted limit. Our observations are highly relevant to
the persistent spin dynamics debate on $R_2$Ti$_2$O$_7$ pyrochlores and their
crystal quality.


title:
The application of MultiView Methods for High Precision Astrometric
  Space VLBI at Low Frequencies

abstract:
  High precision astrometric Space Very Long Baseline Interferometry (S-VLBI)
at the low end of the conventional frequency range, i.e. 20cm, is a requirement
for a number of high priority science goals. These are headlined by obtaining
trigonometric parallax distances to pulsars in Pulsar--Black Hole pairs and OH
masers anywhere in the Milky Way Galaxy and the Magellanic Clouds. We propose a
solution for the most difficult technical problems in S-VLBI by the MultiView
approach where multiple sources, separated by several degrees on the sky, are
observed simultaneously. We simulated a number of challenging S-VLBI
configurations, with orbit errors up to 8m in size and with ionospheric
atmospheres consistant with poor conditions. In these simulations we performed
MultiView analysis to achieve the required science goals. This approach removes
the need for beam switching requiring a Control Moment Gyro, and the space and
ground infrastructure required for high quality orbit reconstruction of a
space-based radio telescope. This will dramatically reduce the complexity of
S-VLBI missions which implement the phase-referencing technique.


title:
ALMA Observations of the Galactic Center: SiO Outflows and High Mass
  Star Formation near Sgr A*

abstract:
  ALMA observations of the Galactic center with spatial resolution
$2.61"\times0.97"$ resulted in the detection of 11 SiO (5-4) clumps of
molecular gas within 0.6pc (15$"$) of Sgr A*, interior to the 2-pc
circumnuclear molecular ring. The three SiO (5-4) clumps closest to Sgr A* show
the largest central velocities, $\sim150$ \kms, and broadest asymmetric
linewidths with full width zero intensity (FWZI) $\sim110-147$ \kms. The
remaining clumps, distributed mainly to the NE of the ionized mini-spiral, have
narrow FWZI ($\sim18-56$ \kms). Using CARMA SiO (2-1) data, LVG modeling of the
the SiO line ratios for the broad velocity clumps, constrains the column
density N(SiO) $\sim10^{14}$ cm$^{-2}$, and the H$_2$ gas density n$_{\rm
H_2}=(3-9)\times10^5$ cm$^{-3}$ for an assumed kinetic temperature 100-200K.
The SiO clumps are interpreted as highly embedded protostellar outflows,
signifying an early stage of massive star formation near Sgr A* in the last
$10^4-10^5$ years. Support for this interpretation is provided by the SiO (5-4)
line luminosities and velocity widths which lie in the range measured for
protostellar outflows in star forming regions in the Galaxy. Furthermore, SED
modeling of stellar sources shows two YSO candidates near SiO clumps,
supporting in-situ star formation near Sgr A*. We discuss the nature of star
formation where the gravitational potential of the black hole dominates. In
particular, we suggest that external radiative pressure exerted on
self-shielded molecular clouds enhances the gas density, before the gas cloud
become gravitationally unstable near Sgr A*. Alternatively, collisions between
clumps in the ring may trigger gravitational collapse.


title: Luminosity Evolution of Rotation-powered Gamma-ray Pulsars

abstract:
  We investigate the electrodynamic structure of a pulsar outer-magnetospheric
particle accelerator and the resultant gamma-ray emission. By considering the
condition for the accelerator to be self-sustained, we derive how the
trans-magnetic-field thickness of the accelerator evolves with the pulsar age.
It is found that the thickness is small but increases steadily if the
neutron-star envelope is contaminated by sufficient light elements. For such a
light element envelope, the gamma-ray luminosity of the accelerator is kept
approximately constant as a function of age in the initial ten thousand years,
forming the lower bound of the observed distribution of the gamma-ray
luminosity of rotation-powered pulsars. If the envelope consists of only heavy
elements, on the other hand, the thickness is greater but increases less
rapidly than what a light element envelope has. For such a heavy element
envelope, the gamma-ray luminosity decreases relatively rapidly, forming the
upper bound of the observed distribution. The gamma-ray luminosity of a general
pulsar resides between these two extreme cases, reflecting the envelope
composition and the magnetic inclination angle with respect to the rotation
axis.


title:
Theory of Electromagnetically Induced Transparency in Strongly
  Correlated Quantum Gases

abstract:
  We develop a general theory to study the electromagnetically induced
transparency (EIT) in ultracold quantum gases, applicable for both Bose and
Fermi gases with arbitrary inter-particle interaction strength. We show that,
in the weak probe field limit, the EIT spectrum is solely determined by the
single particle Green's function of the ground state atoms, and reflects
interesting quantum many-body effects when atoms are virtually coupled to the
low-lying Rydberg states. As an example, we apply our theory to 1D Luttinger
liquid, Bose-Mott insulator state, and the superfluid state of two-component
Fermi gases, and show how the many-body features can be observed
non-destructively in the unconventional EIT spectrum.


title:
Generation of polarization-entangled photon pairs in a Bragg reflection
  waveguide

abstract:
  We demonstrate experimentally that spontaneous parametric down-conversion in
an AlGaAs semiconductor Bragg reflection waveguide can make for paired photons
highly entangled in the polarization degree of freedom at the telecommunication
wavelength of 1550 nm. The pairs of photons show visibility higher than 90% in
several polarization bases and violate a Clauser-Horne-Shimony-Holt Bell-like
inequality by more than 3 standard deviations. This represents a significant
step toward the realization of efficient and versatile self pumped sources of
entangled photon pairs on-chip.


title: Anisotropic fluid in a time dependent conformally flat spacetime

abstract:
  The special conformal transformation (composed by inversion - translation -
inversion) is used to generate a time dependent conformally flat spacetime. In
order to be an exact solution of Einstein's equations, we need as a source a
stress tensor corresponding to an anisotropic fluid with negative regular
energy density and positive pressures. For the static approximation, the
generators of the infinitesimal transformation resemble those recently obtained
by Majhi and Padmanabhan for the coordinate transformation leading to the "near
horizon" Schwarzschild metric in Kruskal coordinates. The static approximation
corresponds to an energy momentum tensor of $\Lambda$ - form, the "cosmological
constant" $\Lambda$ being proportional to the acceleration squared.


title: CZF does not have the Existence Property

abstract:
  Constructive theories usually have interesting metamathematical properties
where explicit witnesses can be extracted from proofs of existential sentences.
For relational theories, probably the most natural of these is the existence
property, EP, sometimes referred to as the set existence property. This states
that whenever (\exists x)\phi(x) is provable, there is a formula \chi(x) such
that (\exists ! x)\phi(x) \wedge \chi(x) is provable. It has been known since
the 80's that EP holds for some intuitionistic set theories and yet fails for
IZF. Despite this, it has remained open until now whether EP holds for the most
well known constructive set theory, CZF. In this paper we show that EP fails
for CZF.


title: Bayesian analysis of anisotropic cosmologies: Bianchi VII_h and WMAP

abstract:
  We perform a definitive analysis of Bianchi VII_h cosmologies with WMAP
observations of the cosmic microwave background (CMB) temperature anisotropies.
Bayesian analysis techniques are developed to study anisotropic cosmologies
using full-sky and partial-sky, masked CMB temperature data. We apply these
techniques to analyse the full-sky internal linear combination (ILC) map and a
partial-sky, masked W-band map of WMAP 9-year observations. In addition to the
physically motivated Bianchi VII_h model, we examine phenomenological models
considered in previous studies, in which the Bianchi VII_h parameters are
decoupled from the standard cosmological parameters. In the two
phenomenological models considered, Bayes factors of 1.7 and 1.1 units of
log-evidence favouring a Bianchi component are found in full-sky ILC data. The
corresponding best-fit Bianchi maps recovered are similar for both
phenomenological models and are very close to those found in previous studies
using earlier WMAP data releases. However, no evidence for a phenomenological
Bianchi component is found in the partial-sky W-band data. In the physical
Bianchi VII_h model we find no evidence for a Bianchi component: WMAP data thus
do not favour Bianchi VII_h cosmologies over the standard Lambda Cold Dark
Matter (LCDM) cosmology. It is not possible to discount Bianchi VII_h
cosmologies in favour of LCDM completely, but we are able to constrain the
vorticity of physical Bianchi VII_h cosmologies at $(\omega/H)_0 < 8.6 \times
10^{-10}$ with 95% confidence.


title:
Nonsmooth Bifurcations, Transient Hyperchaos and Hyperchaotic Beats in a
  Memristive Murali-Lakshmanan-Chua Circuit

abstract:
  In this paper, a memristive Murali-Lakshmanan-Chua (MLC) circuit is built by
replacing the nonlinear element of an ordinary MLC circuit, namely the Chua's
diode, with a three segment piecewise linear active flux controlled memristor.
The bistability nature of the memristor introduces two discontinuty boundaries
or switching manifolds in the circuit topology. As a result, the circuit
becomes a piecewise smooth system of second order. Grazing bifurcations, which
are essentially a form of discontinuity induced non-smooth bifurcations, occur
at these boundaries and govern the dynamics of the circuit. While the
interaction of the memristor aided self oscillations of the circuit and the
external sinusoidal forcing result in the phenomenon of beats occurring in the
circuit, grazing bifurcations endow them with chaotic and hyper chaotic nature.
In addition the circuit admits a codimension-5 bifurcation and transient hyper
chaos. Grazing bifurcations as well as other behaviors have been analyzed
numerically using time series plots, phase portraits, bifurcation diagram,
power spectra and Lyapunov spectrum, as well as the recent 0-1 K test for
chaos, obtained after constructing a proper Zero Time Discontinuity Map (ZDM)
and Poincare Discontinuity Map (PDM) analytically. Multisim simulations using a
model of piecewise linear memristor have also been used to confirm some of the
behaviors.


title:
Self-frequency blue-shift of dissipative solitons in silicon based
  waveguides

abstract:
  We analyze the dynamics of dissipative solitons in silicon on insulator
waveguides embedded in a gain medium. The optical propagation is modeled
through a cubic Ginzburg-Landau equation for the field envelope coupled with an
ordinary differential equation accounting for the generation of free carriers
owing to two-photon absorption. Our numerical simulations clearly indicate that
dissipative solitons accelerate due to the carrier-induced index change and
experience a considerable blue-shift, which is mainly hampered by the gain
dispersion of the active material. Numerical results are fully explained by
analytical predictions based on soliton perturbation theory.


title: Decoherence, relaxation and chaos in a kicked-spin ensemble

abstract:
  We study the dynamics of a quantum spin ensemble controlled by trains of
ultrashort pulses. To model disturbances of the kicks, we consider that the
spins are submitted to different kick trains which follow regular, random,
stochastic or chaotic dynamical processes. These are described by dynamical
systems on a torus. We study the quantum decoherence and the population
relaxation of the spin ensemble induced by these classical dynamical processes
disturbing the kick trains. For chaotic kick trains we show that the
decoherence and the relaxation processes exhibit a signature of chaos directly
related to the Lyapunov exponents of the dynamical system. This signature is a
horizon of coherence, i.e. a preliminary duration without decoherence followed
by a rapid decoherence process.


title: Extremes of scale mixtures of multivariate time series

abstract:
  Factor models have large potencial in the modeling of several natural and
human phenomena. In this paper we consider a multivariate time series
$\mb{Y}_n$, ${n\geq 1}$, rescaled through random factors $\mb{T}_n$, ${n\geq
1}$, extending some scale mixture models in the literature. We analyze its
extremal behavior by deriving the maximum domain of attraction and the
multivariate extremal index, which leads to new ways to construct multivariate
extreme value distributions. The computation of the multivariate extremal index
and the characterization of the tail dependence show the interesting property
of these models that however much it is the dependence within and between
factors $\mb{T}_n$, ${n\geq 1}$, the extremal index of the model is unit
whenever $\mb{Y}_n$, ${n\geq 1}$, presents cross-sectional and sequencial tail
independence. We illustrate with examples of thinned multivariate time series
and multivariate autoregressive processes with random coefficients. An
application of these latter to financial data is presented at the end.


title:
Differential Batalin-Vilkovisky algebras arising from twilled
  Lie-Rinehart algebras

abstract:
  Twilled L(ie-)R(inehart)-algebras generalize, in the Lie-Rinehart context,
complex structures on smooth manifolds. An almost complex manifold determines
an "almost twilled pre-LR algebra", which is a true twilled LR-algebra iff the
almost complex structure is integrable. We characterize twilled LR structures
in terms of certain associated differential (bi)graded Lie and
G(erstenhaber)-algebras; in particular the G-algebra arising from an almost
complex structure is a d(ifferential) G-algebra iff the almost complex
structure is integrable. Such G-algebras, endowed with a generator turning them
into a B(atalin-)V(ilkovisky)-algebra, occur on the B-side of the mirror
conjecture. We generalize a result of Koszul to those dG-algebras which arise
from twilled LR-algebras. A special case thereof explains the relationship
between holomorphic volume forms and exact generators for the corresponding
dG-algebra and thus yields in particular a conceptual proof of the Tian-Todorov
lemma. We give a differential homological algebra interpretation for twilled
LR-algebras and by means of it we elucidate the notion of generator in terms of
homological duality for differential graded LR-algebras.


title:
Generalized Coupling Parameter Expansion: Application to Square-Well and
  Lennard Jones Fluids

abstract:
  The coupling parameter expansion in thermodynamic perturbation theory of
simple fluids is generalized to include the derivatives of bridge function. We
applied seventh order version of the theory to Square-Well (SW) and
Lennard-Jones (LJ) fluids using Sarkisov Bridge function. In both cases, the
theory reproduced the radial distribution functions obtained from integral
equation theory (IET) and simulations with good accuracy. Also, the method
worked inside the liquid-vapor coexistence region where the IETs are known to
fail. In the case of SW fluids, the use of Carnahan-Starling expression for
free energy density of Hard-Sphere reference system has improved the
liquid-vapor phase diagram (LVPD) over that obtained from IET. We also obtained
the surface tension of SW fluids of various ranges. Results of present theory
and simulations are in good agreement. In the case of LJ fluids, the equation
of state obtained from the present method matched with that obtained from IET
with negligible deviation. We also obtained LVPD of LJ fluid from virial and
energy routes and found that there is slight inconsistency between the two
routes. The applications lead to the following conclusions. In cases where
reference system properties are known accurately, the present method gives
results which are very much improved over those obtained from the IET with the
same bridge function. In cases where reference system data is not available,
the method serves as an alternative way of solving the Ornstein-Zernike
equation with a given closure relation with the advantage that solution can be
obtained throughout the phase diagram with a proper choice of the reference
system.


title:
In search of high performance anode materials for Mg batteries:
  computational studies of Mg in Ge, Si, and Sn

abstract:
  We present ab initio studies of structures, energetics, and diffusion
properties of Mg in Si, Ge, and Sn diamond structures to evaluate their
potential as insertion type anode materials for Mg batteries. We show that Si
could provide the highest specific capacities (3817 mAh g-1) and the lowest
average insertion voltage (~0.15 eV vs. Mg) for Mg storage. Nevertheless, due
to its significant percent lattice expansion (~216%) and slow Mg diffusion, Sn
and Ge are more attractive; both anodes have lower lattice expansions (~120 %
and ~178 %, respectively) and diffusion barriers (~0.50 and ~0.70 eV,
respectively for single-Mg diffusion) than Si. We show that Mg-Mg interactions
at different stages of charging can decrease significantly the diffusion
barrier compared to the single atom diffusion, by up to 0.55 eV.


title:
Mid-infrared observations of the circumstellar disks around PDS 66 and
  CRBR 2422.8-3423

abstract:
  Aims: We present mid-infrared observations and photometry of the
circumstellar disks around PDS 66 and CRBR 2422.8-3423, obtained with VISIR/VLT
in the N band and for the latter also in the Q band. Our aim is to resolve the
inner regions of these protoplanetary disks, which carry potential signatures
of intermediate or later stages of disk evolution and ongoing planet formation.
  Methods: We determined the radial brightness profiles of our target objects
and the corresponding PSF reference that were observed before and after our
target objects. Background standard deviations, the standard errors, and the
seeing variations during the observations were considered. Adopting a simple
radiative transfer model based on parameters taken from previous studies, we
derived constraints on the inner-disk hole radius of the dust disk.
  Results: Neither of the circumstellar disks around our science targets are
spatially resolved in our observations. However, we are able to constrain the
inner-disk hole radius to <15.0(+0.5,-0.5) AU and <10.5(+0.5,-1.0) AU for PDS
66 and CRBR 2422.8-3423, respectively. The photometry we performed yields
N-band flux densities of 599+-8 mJy for PDS 66 and 130+-14 mJy for CRBR
2422.8-3423, as well as a Q-band flux density of 858+-109 mJy for CRBR
2422.8-3423.


title: The metallicity signature of evolved stars with planets

abstract:
  We determine in a homogeneous way the metallicity and individual abundances
of a large sample of evolved stars, with and without known planetary
companions. Our methodology is based on the analysis of high-resolution echelle
spectra. The metallicity distributions show that giant stars hosting planets
are not preferentially metal-rich having similar abundance patterns to giant
stars without known planetary companions. We have found, however, a very strong
relation between the metallicity distribution and the stellar mass within this
sample. We show that the less massive giant stars with planets (M < 1.5 Msun)
are not metal rich, but, the metallicity of the sample of massive (M > 1.5
Msun), young (age < 2 Gyr) giant stars with planets is higher than that of a
similar sample of stars without planets. Regarding other chemical elements,
giant stars with and without planets in the mass domain M < 1.5 Msun show
similar abundance patterns. However, planet and non-planet hosts with masses M
> 1.5 Msun show differences in the abundances of some elements, specially Na,
Co, and Ni. In addition, we find the sample of subgiant stars with planets to
be metal rich showing similar metallicities to main-sequence planet hosts. The
fact that giant planet hosts in the mass domain M < 1.5 Msun do not show
metal-enrichment is difficult to explain. Given that these stars have similar
stellar parameters to subgiants and main-sequence planet hosts, the lack of the
metal-rich signature in low-mass giants could be explained if originated from a
pollution scenario in the main sequence that gets erased as the star become
fully convective. However, there is no physical reason why it should play a
role for giants with masses M < 1.5 Msun but is not observed for giants with M
> 1.5 Msun.


title: Dynamical realizations of l-conformal Newton-Hooke group

abstract:
  The method of nonlinear realizations and the technique previously developed
in arXiv:1208.1403 are used to construct a dynamical system without higher
derivative terms, which holds invariant under the l-conformal Newton-Hooke
group. A configuration space of the model involves coordinates, which
parametrize a particle moving in d spatial dimensions and a conformal mode,
which gives rise to an effective external field.The dynamical system describes
a generalized multi-dimensional oscillator, which undergoes
accelerated/decelerated motion in an ellipse in accord with evolution of the
conformal mode. Higher derivative formulations are discussed as well. It is
demonstrated that the multi-dimensional Pais-Uhlenbeck oscillator enjoys the
l=3/2-conformal Newton-Hooke symmetry for a particular choice of its
frequencies.


title: Excitation of weakly-bound molecules to trilobite-like Rydberg states

abstract:
  We observe "trilobite-like" states of ultracold 85Rb2 molecules, in which a
ground-state atom is bound by the electronic wavefunction of its Rydberg-atom
partner. We populate these states through the ultraviolet excitation of
weakly-bound molecules, and access a regime of trilobite-like states at low
principal quantum numbers and with vibrational turning points around 35 Bohr
radii. This demonstrates that, unlike previous studies that used free-to-bound
transitions, trilobite-like states can also be excited through bound-to-bound
transitions. This approach provides high excitation probabilities without
requiring high-density samples, and affords the ability to control the
excitation radius by selection of the initial-state vibrational level.


title:
The intersection spectrum of Skolem sequences and its applications to
  lambda fold cyclic triple systems, together with the Supplement

abstract:
  A Skolem sequence of order n is a sequence S_n=(s_{1},s_{2},...,s_{2n}) of 2n
integers containing each of the integers 1,2,...,n exactly twice, such that two
occurrences of the integer j in {1,2,...,n} are separated by exactly j-1
integers. We prove that the necessary conditions are sufficient for existence
of two Skolem sequences of order n with 0,1,2,...,n-3 and n pairs in same
positions. Further, we apply this result to the fine structure of cyclic two,
three and four-fold triple systems, and also to the fine structure of
lambda-fold directed triple systems and lambda-fold Mendelsohn triple systems.
  For a better understanding of the paper we added more details into a
"Supplement".


title: Controling the number of focal elements

abstract:
  A basic belief assignment can have up to 2^n focal elements, and combining
them with a simple conjunctive operator will need O(2^2n) operations. This
article proposes some techniques to limit the size of the focal sets of the
bbas to be combined while preserving a large part of the information they
carry. The first section revisits some well-known definitions with an
algorithmic point of vue. The second section proposes a matrix way of building
the least committed isopignistic, and extends it to some other bodies of
evidence. The third section adapts the k-means algorithm for an unsupervized
clustering of the focal elements of a given bba.


title:
On the continuum limit of Landau gauge gluon and ghost propagators in
  SU(2) lattice gauge gluodynamics

abstract:
  We continue the systematic computation of Landau gauge gluon and ghost
propagators of SU(2) gluodynamics using a sequence of increasing lattice sizes
L^4 up to L=112 with corresponding \beta-values chosen to keep the linear
physical size a(\beta)L ~ 9.6 fm fixed. To extremize the Landau gauge
functional we employ simulated annealing combined with subsequent
overrelaxation. Renormalizing the propagators at momentum \mu= 2.2 GeV we
observe quite strong lattice artifacts for the gluon propagator as well as for
the ghost dressing function within the momentum region q < 1.0 GeV. The
dependence on the lattice spacing for the gluon propagator at lowest accessible
physical momentum values does not yet allow a simple extrapolation to the
continuum limit. On the contrary, the running coupling derived from the bare
dressing functions seems less affected by lattice artifacts.


title: A fractional Muckenhoupt-Wheeden theorem and its consequences

abstract:
  In the 1970s Muckenhoupt and Wheeden made several conjectures relating two
weight norm inequalities for the Hardy-Littlewood maximal operator to such
inequalities for singular integrals. Using techniques developed for the recent
proof of the $A_2$ conjecture we prove a related pair of conjectures linking
the Riesz potential and the fractional maximal operator. As a consequence we
are able to prove a number of sharp one and two weight norm inequalities for
the Riesz potential.


title: Z2 topological invariants in two dimensions from quantum Monte Carlo

abstract:
  We employ quantum Monte Carlo techniques to calculate the $Z_2$ topological
invariant in a two-dimensional model of interacting electrons that exhibits a
quantum spin Hall topological insulator phase. In particular, we consider the
parity invariant for inversion-symmetric systems, which can be obtained from
the bulk's imaginary-time Green's function after an appropriate continuation to
zero frequency. This topological invariant is used here in order to study the
trivial-band to topological-insulator transitions in an interacting system with
spin-orbit coupling and an explicit bond dimerization. We discuss the
accessibility and behavior of this topological invariant within quantum Monte
Carlo simulations.


title:
Observations and modeling of the emerging EUV loops in the quiet Sun as
  seen with the Solar Dynamics Observatory

abstract:
  We used data from the Helioseismic and Magnetic Imager (HMI), and Atmospheric
Imaging Assembly (AIA) on the \textit{Solar Dynamics Observatory} (SDO) to
study coronal loops at small scales, emerging in the quiet Sun. With HMI
line-of-sight magnetograms, we derive the integrated and unsigned photospheric
magnetic flux at the loop footpoints in the photosphere. These loops are bright
in the EUV channels of AIA. Using the six AIA EUV filters, we construct the
differential emission measure (DEM) in the temperature range $5.7 - 6.5$ in log
$T$ (K) for several hours of observations. The observed DEMs have a peak
distribution around log $T \approx$ 6.3, falling rapidly at higher
temperatures. For log $T <$ 6.3, DEMs are comparable to their peak values
within an order of magnitude. The emission weighted temperature is calculated,
and its time variations are compared with those of magnetic flux. We present
two possibilities for explaining the observed DEMs and temperatures variations.
(a) Assuming the observed loops are comprised of hundred thin strands with
certain radius and length, we tested three time-dependent heating models and
compared the resulting DEMs and temperatures with the observed quantities. This
modeling used Enthalpy-based Thermal Evolution of Loops (EBTEL), a
zero-dimensional (0D) hydrodynamic code. The comparisons suggest that a medium
frequency heating model with a population of different heating amplitudes can
roughly reproduce the observations. (b) We also consider a loop model with
steady heating and non-uniform cross-section of the loop along its length, and
find that this model can also reproduce the observed DEMs, provided the loop
expansion factor $\gamma \sim$ 5 - 10. More observational constraints are
required to better understand the nature of coronal heating in the short
emerging loops on the quiet Sun.


title:
Distributed Space-Time Coding of Over-the-Air Superimposed Packets in
  Wireless Networks

abstract:
  In this paper we propose a new cooperative packet transmission scheme that
allows independent sources to superimpose over-the-air their packet
transmissions. Relay nodes are used and cooperative diversity is combined with
distributed space-time block coding (STBC). With the proposed scheme the
participating relays create a ST code for the over-the-air superimposed symbols
that are received locally and without proceeding to any decoding step
beforehand. The advantage of the proposed scheme is that communication is
completed in fewer transmission slots because of the concurrent packet
transmissions, while the diversity benefit from the use of the STBC results in
higher decoding performance. The proposed scheme does not depend on the STBC
that is applied at the relays. Simulation results reveal significant throughput
benefits even in the low SNR regime.


title:
Constraints on Scalar Spectral Index from Latest Observational
  Measurements

abstract:
  Recently, the nine-year data release of the Wilkinson Microwave Anisotropy
Probe (WMAP9) found that the inflationary models with the scalar spectral index
n_s \geq 1 are excluded at about 5\sigma confidence level. In this paper, we
set the new limits on the scalar spectral index in different cosmological
models combining the WMAP9 data with the small-scale cosmic microwave
background measurement from the South Pole Telescope, baryon acoustic
oscillation data, Hubble Telescope measurements of the Hubble constant, and
supernovae luminosity distance data. In most of extended cosmological models,
e.g. with a dark energy equation of state, the constraints on n_s do not change
significantly. The Harrison-Zel'dovich-Peebles (HZ) scale invariant spectrum is
still disfavored at more than 4\sigma confidence level. However, when
considering the model with a number of relativistic species N_{eff}, we obtain
the limit on the spectral index of n_s=0.980\pm0.011 (1\sigma), due to the
strong degeneracy between n_s and N_{eff}. The HZ spectrum now is still
consistent with the current data at 95% confidence level.


title: Intrinsic Bistability In Quantum Point Contacts with in-plane Side Gates

abstract:
  We study the onset of intrinsic bistability and accompanying hysteresis in a
single quantum point contact (QPC) with in-plane side gates in the presence of
lateral spin-orbit coupling. The hysteresis in the conductance versus common
gate voltage applied to the two side gates exists only if the narrow portion of
the QPC is long enough. The hysteresis is absent if the effects of
electron-electron interaction are neglected but increases with the strength of
the electron-electron interaction. The hysteresis appears in the region of
conductance anomalies, i.e., less than 2e2/h, and is due to multistable spin
textures in these regions.


title:
Towards the classification of integrable differential-difference
  equations in 2 + 1 dimensions

abstract:
  We address the problem of classification of integrable
differential-difference equations in 2+1 dimensions with one/two discrete
variables. Our approach is based on the method of hydrodynamic reductions and
its generalisation to dispersive equations. We obtain a number of
classification results of scalar integrable equations including that of the
intermediate long wave and Toda type.


title:
Relativistic distribution function for particles with spin at local
  thermodynamical equilibrium

abstract:
  We present an extension of relativistic single-particle distribution function
for weakly interacting particles at local thermodynamical equilibrium including
spin degrees of freedom, for massive spin 1/2 particles. We infer, on the basis
of the global equilibrium case, that at local thermodynamical equilibrium
particles acquire a net polarization proportional to the vorticity of the
inverse temperature four-vector field. The obtained formula for polarization
also implies that a steady gradient of temperature entails a polarization
orthogonal to particle momentum. The single-particle distribution function in
momentum space extends the so-called Cooper-Frye formula to particles with spin
1/2 and allows to predict their polarization in relativistic heavy ion
collisions at the freeze-out.


title: Discrete-time quantum walk with feed-forward quantum coin

abstract:
  Constructing a discrete model like a cellular automaton is a powerful method
for understanding various dynamical systems. However, the relationship between
the discrete model and its continuous analogue is, in general, nontrivial. As a
quantum-mechanical cellular automaton, a discrete-time quantum walk is defined
to include various quantum dynamical behavior. Here we generalize a
discrete-time quantum walk on a line into the feed-forward quantum coin model,
which depends on the coin state of the previous step. We show that our proposed
model has an anomalous slow diffusion characterized by the porous-medium
equation, while the conventional discrete-time quantum walk model shows
ballistic transport.

categories: quant-ph cond-mat.other math-ph math.MP nlin.CG physics.optics


title:
Magnetic hysteresis loop as a probe to distinguish single layer from
  many layer graphitic structure

abstract:
  In this report we have pointed out that magnetic hysteresis loop can be used
as a probe to distinguish a single layer from a many layer graphitic structure.
Chemically we have synthesized graphitic oxide (GO) and reduced graphitic oxide
(RGO) for this investigation. We observe ferromagnetic like hysteresis loops
for both GO and RGO below a certain applied critical magnetic field and above
this critical field we observe cross-over of the positive magnetization to
negative magnetization leading to diamagnetic behaviour. This cross-over is
more dominant for the case of many layer graphitic structure. Upon annealing of
GO in air the critical cross-over field decreases and the magnetization
increases for multilayer graphitic structure. Possible reasons for all these
observations and phenomena is presented here.


title: A Quasi-Lie Schemes Approach to Second-Order Gambier Equations

abstract:
  A quasi-Lie scheme is a geometric structure that provides t-dependent changes
of variables transforming members of an associated family of systems of
first-order differential equations into members of the same family. In this
note we introduce two quasi-Lie schemes for studying second-order Gambier
equations in a geometric way. This allows us to study the transformation of
these equations into simpler canonical forms, which solves a gap in the
previous literature, and other relevant differential equations, which leads to
derive new constants of motion for families of second-order Gambier equations.
Additionally, we describe general solutions of certain second-order Gambier
equations in terms of particular solutions of Riccati equations, linear
systems, and t-dependent frequency harmonic oscillators.


title:
Proposed robust and high-fidelity preparation of excitons and biexcitons
  in semiconductor quantum dots making active use of phonons

abstract:
  It is demonstrated how the exciton and the biexciton state of a quantum dot
can be prepared with high fidelity on a picosecond time-scale by driving the
dot with a strong laser pulse that is tuned above the exciton resonance for
exciton preparation and in resonance with the exciton transition for biexciton
preparation. The proposed schemes make use of the phonon-induced relaxation
towards photon dressed states in optically driven quantum dots and combine the
simplicity of Rabi flopping with the robustness of adiabatic rapid passage
schemes. Our protocols allow for an on-demand, fast and almost perfect state
preparation even at strong carrier-phonon interaction where other schemes fail.
In fact, the performance of the presented protocols is shown to be the better
the stronger the carrier-phonon interaction is.


title: Cosmology with Ricci dark energy

abstract:
  We assume the cosmological dark sector to consist of pressureless matter and
holographic dark energy with a cutoff length proportional to the Ricci scale.
The requirement of separate energy-momentum conservation of the components is
shown to establish a relation between the matter fraction and the (necessarily
time-dependent) equation-of-state parameter of the dark energy. Focusing on
intrinsically adiabatic pressure perturbations of the dark-energy component,
the matter perturbations are found as linear combinations of the total
energy-density perturbations of the cosmic medium and the relative
(nonadiabatic) perturbations of the components. The resulting background
dynamics is consistent with observations from supernovae of type Ia, baryonic
acoustic oscillations and the differential age of old objects. The perturbation
dynamics, on the other hand, is plagued by instabilities which excludes any
phantom-type equation of state. The only stable configuration is singled out by
a fixed relation between the present matter fraction $\Omega_{m0}$ and the
present value $\omega_{0}$ of the equation-of-state parameter of the dark
energy. However, this instability-avoiding configuration is only marginally
consistent with the observationally preferred background values of the
mentioned parameters.


title:
Criterion on remote clocks synchronization within a Heisenberg scaling
  accuracy

abstract:
  We propose a quantum method to judge whether two spatially separated clocks
have been synchronized within a specific accuracy $\sigma$. If the measurement
result of the experiment is obviously a nonzero value, the time difference
between two clocks is smaller than $\sigma$; otherwise the difference is beyond
$\sigma$. On sharing the 2$N$-qubit bipartite maximally entangled state in this
scheme, the accuracy of judgement can be enhanced to
$\sigma\sim{\pi}/{(\omega(N+1))}$. This criterion is consistent with Heisenberg
scaling that can be considered as beating standard quantum limit, moreover, the
unbiased estimation condition is not necessary.


title: A new approach to the Lenard-Magri scheme of integrability

abstract:
  We develop a new approach to the Lenard-Magri scheme of integrability of
bi-Hamiltonian PDE's, when one of the Poisson structures is a strongly
skew-adjoint differential operator.


title:
Bounds for Invariant Distances on Pseudoconvex Levi Corank One Domains
  and Applications

abstract:
  Let $D \subset \mathbb{C}^n$ be a smoothly bounded pseudoconvex Levi corank
one domain with defining function $r$, i.e., the Levi form $\partial \bar
{\partial} r$ of the boundary $\partial D$ has at least $(n - 2)$ positive
eigenvalues everywhere on $\partial D$. The main goal of this article is to
obtain a lower bound for the Carath\'{e}odory, Kobayashi and the Bergman
distance between a given pair of points $p, q \in D$ in terms of parameters
that reflect the Levi geometry of $\partial D$ and the distance of these points
to the boundary. Applications include an understanding of Fridman's invariant
for the Kobayashi metric on Levi corank one domains, a description of the balls
in the Kobayashi metric on such domains that are centered at points close to
the boundary in terms of Euclidean data and the boundary behaviour of Kobayashi
isometries from such domains.


title: Towards a Synergy-based Approach to Measuring Information Modification

abstract:
  Distributed computation in artificial life and complex systems is often
described in terms of component operations on information: information storage,
transfer and modification. Information modification remains poorly described
however, with the popularly-understood examples of glider and particle
collisions in cellular automata being only quantitatively identified to date
using a heuristic (separable information) rather than a proper
information-theoretic measure. We outline how a recently-introduced axiomatic
framework for measuring information redundancy and synergy, called partial
information decomposition, can be applied to a perspective of distributed
computation in order to quantify component operations on information. Using
this framework, we propose a new measure of information modification that
captures the intuitive understanding of information modification events as
those involving interactions between two or more information sources. We also
consider how the local dynamics of information modification in space and time
could be measured, and suggest a new axiom that redundancy measures would need
to meet in order to make such local measurements. Finally, we evaluate the
potential for existing redundancy measures to meet this localizability axiom.


title: Ranks for strongly dependent theories

abstract:
  There is much more known about the family of superstable theories when
compared to stable theories. This calls for a search of an analogous
"super-dependent" characterization in the context of dependent theories. This
problem has been treated in \cite{Sh:783,Sh:863}, where the candidates
"Strongly dependent", "Strongly dependent^2" and others were considered. These
families generated new families when we are considering intersections with the
stable family. Here, continuing \cite[\S 2, \S 5E,F,G]{Sh:863}, we deal with
several candidates, defined using dividing properties and related ranks of
types. Those candidates are subfamilies of "Strongly dependent". Fulfilling
some promises from \cite{Sh:863} in particular \cite[1.4(4)]{Sh:863}, we try to
make this self contained within reason by repeating some things from there.
More specifically we fulfil some promises from \cite{Sh:863} to to give more
details, in particular: in \S4 for \cite[1.4(4)]{Sh:863}, in \S2 for
\cite[5.47(2)=Ldw5.35(2)]{Sh:863} and in \S1 for \cite[5.49(2)]{Sh:863}


title: Low energy electron-phonon effective action from symmetry analysis

abstract:
  Based on a detailed symmetry analysis, we state the general rules to build up
the effective low energy field theory describing a system of electrons weakly
interacting with the lattice degrees of freedom. The basic elements in our
construction are what we call the "memory tensors", that keep track of the
microscopic discrete symmetries into the coarse-grained action. The present
approach can be applied to lattice systems in arbitrary dimensions and in a
systematic way to any desired order in derivatives. We apply the method to the
honeycomb lattice and re-obtain the by now well-known effective action of Dirac
fermions coupled to fictitious gauge fields. As a second example, we derive the
effective action for electrons in the kagom\'e lattice, where our approach
allows to obtain in a simple way the low energy electron-phonon coupling terms.


title:
The Nature of gamma-ray Loud Narrow Line Seyfert I Galaxies PKS 1502+036
  and PKS 2004-447

abstract:
  Variable gamma-ray emission has been discovered in five Radio-loud Narrow
Line Seyfert 1 (NLSy1) galaxies by the Large Area Telescope (LAT) onboard the
Fermi Gamma-Ray Space Telescope. This has clearly demonstrated that these NLSy1
galaxies do have relativistic jets similar to two other cases of gamma-ray
emitting Active Galactic Nuclei (AGN), namely blazars and radio galaxies. We
present here our results on the multi-band analysis of two gamma-ray emitting
NLSy1 galaxies namely PKS 1502+036 (z = 0.409) and PKS 2004-447 (z = 0.240)
using archival data. We generate multi-band long term light curves of these
sources, build their spectral energy distribution (SED) and model them using an
one zone leptonic model. They resemble more to the SEDs of the flat spectrum
radio quasar (FSRQ) class of AGN. We then compare the SEDs of these two sources
with two other Fermi detected AGN along the traditional blazar sequence, namely
the BL Lac Mrk 421 (z = 0.03) and the FSRQ 3C 454.3 (z = 0.86). The SEDs of
both PKS 1502+036 and PKS 2004-447 are found to be intermediate to the SEDs of
Mrk 421 and 3C 454.3. In the gamma-ray spectral index v/s gamma-ray luminosity
plane, both these NLSy1 galaxies occupy a distinct position, wherein, they have
luminosity between Mrk 421 and 3C 454.3, however steep gamma-ray spectra
similar to 3C 454.3. Their Compton dominance as well as their X-ray spectral
slope also lie between Mrk 421 and 3C 454.3. We argue that the physical
properties of both PKS 1502+036 and PKS 2004$-$447 are in general similar to
blazars and intermediate between FSRQs and BL Lac objects and these sources
thus could fit into the traditional blazar sequence.


title: On Homotopy Algebras and Quantum String Field Theory

abstract:
  We revisit the existence, background independence and uniqueness of closed,
open and open-closed bosonic- and topological string field theory, using the
machinery of homotopy algebra. In a theory of classical open- and closed
strings, the space of inequivalent open string field theories is isomorphic to
the space of classical closed string backgrounds. We then discuss obstructions
of these moduli spaces at the quantum level. For the quantum theory of closed
strings, uniqueness on a given background follows from the decomposition
theorem for loop homotopy algebras. We also address the question of background
independence of closed string field theory.


title:
New modular multiplication and division algorithms based on continued
  fraction expansion

abstract:
  In this paper, we apply results on number systems based on continued fraction
expansions to modular arithmetic. We provide two new algorithms in order to
compute modular multiplication and modular division. The presented algorithms
are based on the Euclidean algorithm and are of quadratic complexity.


title:
Rotational symmetry of non negatively curved expanding gradient Ricci
  solitons

abstract:
  Let $(M^n,g,\nabla f)$, $n\geq 3$, be an expanding gradient Ricci soliton
with nonnegative sectional curvature whose asymptotic cone is isometric to
$C(\mathbb{S}^{n-1}(c))$ where $\mathbb{S}^{n-1}(c)$ is the standard
$(n-1)$-sphere of curvature $1/c^2$, with $c\in(0,1)$. We prove that if the
convergence to the asymptotic cone is smooth, $(M^n,g,\nabla f)$ is
rotationally symmetric. This is the expanding analogue of the Perelman
conjecture on the Bryant soliton and this work is based on the proof by Brendle
\cite{Bre-Rot-3d}. This has also been proved recently by Chodosh
\cite{Cho-EGS}.


title:
Observing controlled quantum state collapse in a single quantum
  trajectory of a mechanical oscillator

abstract:
  A fundamental prediction of quantum theory that is derived from the
"projection postulate" is that under continuous measurement, the state of a
system traces out a "quantum trajectory" in time that depends upon its
measurement record, and that in certain situations, the quantum state of a
system stochastically collapses at a finite rate toward a random eigenstate. On
the other hand, quantum theory also predicts that environmental coupling
produces the opposite effect of spreading the wave function into a mixed state.
Studying the effect of these two competing processes, as the ratio of their
strengths is varied, on the distribution of a quantum state is of fundamental
interest in any setting, but especially so in the mechanical realm. A key
issue, however, is that a fundamental study of such physics can not entail an a
priori assumption of the projection postulate itself, and Bayesian inference
may therefore not be employed to observe the quantum state. In this theoretical
work we propose a feasible way to perform such a fundamental test with a
mechanical wave function in the energy eigenbasis. The scheme is based on an
optomechanical setup wherein optical fields provide a direct probe of the
energy variance of the mechanical wave function. Such an energy variance probe
is unprecedented in any type of system. Numerical simulations that incorporate
the projection postulate predict a monotonic decrease in the time-averaged
energy variance as the ratio of continuous measurement strength to dissipation
is increased. The measurement strength in the proposed scheme is tunable in
situ, and the behavior predicted by the simulations therefore implies that the
scheme amounts to a way to verifiably control in situ the time-averaged
variance of a mechanical wave function over the course of a single quantum
trajectory.


title: AGN and Starburst Radio Emission from Optically Selected QSOs

abstract:
  We used the 1.4 GHz NVSS to study radio sources in two color-selected QSO
samples: a volume-limited sample of 1313 QSOs defined by M_i < -23 in the
redshift range 0.2 < z < 0.45 and a magnitude-limited sample of 2471 QSOs with
m_r < 18.5 and 1.8 < z < 2.5. About 10% were detected above the 2.4 mJy NVSS
catalog limit and are powered primarily by AGNs. The space density of the
low-redshift QSOs evolves as rho proportional to (1+z)^6. In both redshift
ranges the flux-density distributions and luminosity functions of QSOs stronger
than 2.4 mJy are power laws, with no features to suggest more than one kind of
radio source. Extrapolating the power laws to lower luminosities predicts the
remaining QSOs should be extremely radio quiet, but they are not. Most were
detected statistically on the NVSS images with median peak flux densities
S_p(mJy/beam) ~ 0.3 and 0.05 in the low- and high-redshift samples,
corresponding to 1.4 GHz spectral luminosities log[L(W/Hz)] ~ 22.7$ and 24.1,
respectively. We suggest that the faint radio sources are powered by star
formation at rates ~20 M_sun per year in the moderate luminosity (median M_i ~
-23.4) low-redshift QSOs and ~500 M_sun per year in the very luminous (M_i} ~
-27.5) high-redshift QSOs. Such luminous starbursts [ log(L / L_sun) ~ 11.2 and
12.6, respectively] are consistent with "quasar mode" accretion in which cold
gas flows fuel both AGN and starburst.


title: Algebraic Cayley Graphs over Finite Fields

abstract:
  A new algebraic Cayley graph is constructed using finite fields. Its
connectedness and diameter bound are studied via Weil's estimate for character
sums. These graphs provide a new source of expander graphs, extending classical
results of Chung.


title:
Real-time game theoretic coordination of competitive mobility-on-demand
  systems

abstract:
  This paper considers competitive mobility-on-demand systems where a group of
vehicle sharing companies, on one hand, want to collectively regulate the
traffic of the user queueing network, and on the other hand, maximize their own
profits at each time instant. We formulate the strategic interconnection among
the companies as a real-time game theoretic coordination problem. We propose an
algorithm to achieve vehicle balance and practical regulation of the user
queueing network. We quantify the relation between the regulation error and the
system parameters (e.g., the maximum variation of the user arrival rates).


title: Additive noise quenches delay-induced oscillations

abstract:
  Noise has significant impact on nonlinear phenomena. Here we demonstrate
that, in opposition to previous assumptions, additive noise interfere with the
linear stability of scalar nonlinear systems when these are subject to time
delay. We show this by performing a recently designed time-dependent delayed
center manifold (DCM) reduction around an Hopf bifurcation in a model of
nonlinear negative feedback. Using this, we show that noise intensity must be
considered as a bifurcation parameter and thus shifts the threshold at which
emerge delay-induced rhythmic solutions.


title:
Null Controllability of a System of Viscoelasticity with a Moving
  Control

abstract:
  In this paper, we consider the wave equation with both a viscous Kelvin-Voigt
and frictional damping as a model of viscoelasticity in which we incorporate an
internal control with a moving support. We prove the null controllability when
the control region, driven by the flow of an ODE, covers all the domain. The
proof is based upon the interpretation of the system as, roughly, the coupling
of a heat equation with an ordinary differential equation (ODE). The presence
of the ODE for which there is no propagation along the space variable makes the
controllability of the system impossible when the control is confined into a
subset in space that does not move. %Accordingly, we consider the control on a
moving support that, along the time interval, covers the whole domain. The null
controllability of the system with a moving control is established in using the
observability of the adjoint system and some Carleman estimates for a coupled
system of a parabolic equation and an ODE with the same singular weight,
adapted to the geometry of the moving support of the control. This extends to
the multi-dimensional case the results by P. Martin et al. on the
one-dimensional case, employing 1-d Fourier analysis techniques.


title: SN 2009ip \'a la PESSTO: No evidence for core-collapse yet

abstract:
  We present observations of the interacting transient SN 2009ip, from the
start of the outburst in October 2012 until the end of the 2012 observing
season. The transient reached a peak of $M_V$=-17.7 mag before fading rapidly,
with a total integrated luminosity of 1.9$\times10^{49}$ erg over the period of
August-December 2012. The optical and near infrared spectra are dominated by
narrow emission lines, signaling a dense circumstellar environment, together
with multiple components of broad emission and absorption in H and He at
velocities between 0.5-1.2$\times10^4$ km s$^{-1}$\. We see no evidence for
nucleosynthesized material in SN 2009ip, even in late-time pseudo-nebular
spectra. We set a limit of $<$0.02 M$_{\odot}$\ on the mass of any synthesized
$^{56}$Ni from the late time lightcurve. A simple model for the narrow Balmer
lines is presented, and used to derive number densities for the circumstellar
medium of between $\sim 10^{9}-10^{10}$ cm$^{-3}$. Our near-infrared data does
not show any excess at longer wavelengths. Our last data, taken in December
2012, shows that SN 2009ip has spectroscopically evolved to something quite
similar to its appearance in late 2009, albeit with higher velocities. It is
possible that neither of the eruptive and high luminosity events of SN 2009ip
were induced by a core-collapse. We show that the peak and total integrated
luminosity can be due to the efficient conversion of kinetic energy from
colliding ejecta, and that around 0.05-0.1 M$_{\odot}$\ of material moving at
0.5-1$\times10^4$ km s$^{-1}$\ could comfortably produce the observed
luminosity. The ejection of multiple shells, lack of evidence for
nucleosynthesied elements and broad nebular lines, are all consistent with the
pulsational-pair instability scenario. In this case the progenitor star may
still exist, and will be observed after the current outburst fades.


title: On an extremal problem connected with simplices

abstract:
  In this note we investigate the behavior of the volume that the convex hull
of two congruent and intersecting simplices in Euclidean $n$-space can have. We
prove some useful equalities and inequalities on this volume. For the regular
simplex we determine the maximal possible volume for the case when the two
simplices are related to each other via reflection at a hyperplane intersecting
them.


title: On estimates of trigonometrical integrals

abstract:
  In this article a new upper bounds for the multiple trigonometrical integrals
are found. The method of the work based on a new method of estimation for the
areas of algebraic surfaces.


title:
Quantum repeaters and quantum key distribution: the impact of
  entanglement distillation on the secret key rate

abstract:
  We investigate quantum repeaters in the context of quantum key distribution.
We optimize the secret key rate per memory per second with respect to different
distillation protocols and distillation strategies. For this purpose, we also
derive an analytical expression for the average number of entangled pairs
created by the quantum repeater, including classical communication times for
entanglement swapping and entanglement distillation. We investigate the impact
of this classical communication time on the secret key rate. We finally study
the effect of the detector efficiency on the secret key rate.


title: Groups whose prime graphs have no triangles

abstract:
  Let G be a finite group and let cd(G) be the set of all complex irreducible
character degrees of G Let \rho(G) be the set of all primes which divide some
character degree of G. The prime graph \Delta(G) attached to G is a graph whose
vertex set is \rho(G) and there is an edge between two distinct primes u and v
if and only if the product uv divides some character degree of G. In this
paper, we show that if G is a finite group whose prime graph \Delta(G) has no
triangles, then \Delta(G) has at most 5 vertices. We also obtain a
classification of all finite graphs with 5 vertices and having no triangles
which can occur as prime graphs of some finite groups. Finally, we show that
the prime graph of a finite group can never be a cycle nor a tree with at least
5 vertices.


title:
Specific many-electron effects in X-ray spectra of simple metals and
  graphene

abstract:
  In this work the influence of many-electron effects on the shape of
characteristic X-ray emission bands of the simple metals Mg and Al are examined
by means of ab initio calculations and semi-empirical models. These approaches
are also used for the analysis of C K-emission and absorption spectra of
graphene. Both, the dynamical screening of the core vacancy and the
Auger-effect in the valence band (VB) have been taken into account. Dynamical
screening of the core vacancy by valence electrons (the so-called MND effect)
is considered ab initio in the framework of density functional theory. The
Auger effect in VB was taken into account within a semi-empirical method,
approximating the quadratic dependence of the VB hole level width on the
difference between the level energy and the Fermi energy. All theoretical
spectra are in very good agreement with available experimental data.


title: Nonequilibrium Model of Photon Condensation

abstract:
  We develop a nonequilibrium model of condensation and lasing of photons in a
dye filled microcavity. We examine in detail the nature of the thermalization
process induced by absorption and emission of photons by the dye molecules, and
investigate when the photons are able to reach a thermal equilibrium
Bose-Einstein distribution. At low temperatures, or large cavity losses, the
absorption and emission rates are too small to allow the photons to reach
thermal equilibrium and the behavior becomes more like that of a conventional
laser.


title: A detailed proof of a theorem of Aubin

abstract: In this note we give a detailed proof of a theorem of Aubin.


title: Lower Bounds for the Number of Generic Initial Ideals

abstract:
  Given a graded ideal $I$ in a polynomial ring over a field $K$ it is well
known, that the number of distinct generic initial ideals of $I$ is finite.
While it is known that for a given $d\in\N$ there is a global upper bound for
the number of generic initial ideals of ideals generated in degree less than
$d$, it is not clear how this bound has to grow with $d$. In this note we will
explicitly give a family $(I(d))_{d\in\N}$ of ideals in $S=K[x,y,z]$, such that
$I(d)$ is generated in degree $d$ and the number of generic initial ideals of
$I(d)$ is bounded from below by a linear bound in $d$. Moreover, this bound
holds for all graded ideals in $S$, which are generic in an appropriate sense.


title: Weyl law for contractive maps

abstract:
  We find the Weyl law followed by the eigenvalues of contractive maps. An
important property is that it is mainly insensitive to the dimension of the
corresponding invariant classical set, the strange attractor. The usual
explanation for the fractal Weyl law emergence in scattering systems (i.e.,
having a projective opening) is based on classical phase space distributions
evolved up to the quantum to classical correspondence (Ehrenfest) time. In the
contractive case this reasoning fails to describe it. Instead, we conjecture
that the support for this behavior is essentially given by the strong
non-orthogonality of the eigenvectors of the contractive superoperator.


title: Two Loop Radiative Seesaw Model with Inert Triplet Scalar Field

abstract:
  We propose a radiative seesaw model with an inert triplet scalar field in
which Majorana neutrino masses are generated at the two loop level. There are
fermionic or bosonic dark matter candidates in the model. We find that each
candidate can satisfy the WMAP data when its mass is taken to be around the
half of the mass of the standard model like Higgs boson. We also discuss
phenomenology of the inert triplet scalar bosons, especially focusing on the
doubly-charged scalar bosons at Large Hadron Collider in parameter regions
constrained by the electroweak precision data and WMAP data. We study how we
can distinguish our model from the minimal Higgs triplet model.


title:
Interplay Between Non-adiabatic Dynamics and Frenkel Exciton Transfer in
  Molecular Aggregates: Formulation and Application to a Perylene Bismide Model

abstract:
  The quantum dynamics of linear molecular aggregates in the presence of S0-S1
and S0-S2 transitions is investigated putting emphasis on the interplay between
local non-adiabatic S2 to S1 deactivation and Frenkel exciton transfer. The
theoretical approach combines aspects of the linear vibronic coupling and
Frenkel exciton models. Dynamics calculations are performed for the absorption
spectrum and the electronic state populations using the multiconfiguration
time-dependent Hartree approach. As an application perylene bisimde J-type
dimer and trimer aggregates are considered, including four tuning and one
coupling mode per monomer. This leads to a dynamical model comprising up to 7
electronic states and 15 vibrational modes. The unknown non-adiabatic coupling
strength is treated as a parameter that is chosen in accordance with available
absorption spectra. This leaves some flexibility that can be limited by the
clearly distinguishable population dynamics.


title:
A direct method for solving optimal stopping problems for L\'evy
  processes

abstract:
  We propose an alternative approach for solving a number of well-studied
optimal stopping problems for L\'evy processes. Instead of the usual method of
guess-and-verify based on martingale properties of the value function, we
suggest a more direct method by showing that the general theory of optimal
stopping for strong Markov processes together with some elementary observations
imply that the stopping set must be of a certain form for the optimal stopping
problems we consider. The independence of increments and the strong Markov
property of L\'evy processes then allow us to use straightforward optimisation
over a real-valued parameter to determine this stopping set. We illustrate this
approach by applying it to the McKean optimal stopping problem (American put),
the Novikov--Shiryaev optimal stopping problem and the Shepp--Shiryaev optimal
stopping problem (Russian option).


title:
Extending positive C-LASS results across multiple instructors and
  multiple classes of Modeling Instruction

abstract:
  We report on a multi-year study of student attitudes measured with the
Colorado Learning Attitudes about Science Survey (CLASS) in calculus-based
introductory physics taught with the Modeling Instruction curriculum. We find
that five of six instructors and eight of nine sections using Modeling
Instruction showed significantly improved attitudes from pre to post-course.
Cohen's d effect sizes range from 0.08 - 0.95 for individual instructors. The
average effect was d = 0.45, with a 95% confidence interval of (0.26 - 0.64).
These results build on previously published results showing positive shifts in
attitudes from Modeling Instruction classes. We interpret these data in light
of other published positive attitudinal shifts and explore mechanistic
explanations for similarities and differences with other published positive
shifts.


title:
Simultaneous Magnetic and Charge Doping of Topological Insulators with
  Carbon

abstract:
  A two-step doping process, magnetic followed by charge or vice versa, is
required to produce insulating massive surface states in topological insulators
for many physics and device applications. Using first-principles calculations,
we demonstrate here simultaneous magnetic and hole doping achieved with a
single dopant, carbon, in Bi2Se3. Carbon substitution for Se (CSe) results in
an opening of a sizable surface Dirac gap (53-85 meV), while the Fermi level
(EF) remains inside the bulk gap and close to the Dirac point at moderate
doping concentrations. The strong localization of 2p states of CSe favors
spontaneous spin polarization via a p-p interaction and formation of ordered
magnetic moments mediated by the surface state. Meanwhile, holes are introduced
into the system by CSe. This dual function of carbon doping suggests a simple
way to realize insulating massive topological surface states.


title:
Statistical mechanics of fluids confined by polytopes: The hidden
  geometry of the cluster integrals

abstract:
  This paper, about a fluid-like system of spatially confined particles,
reveals the analytic structure for both, the canonical and grand canonical
partition functions. The studied system is inhomogeneously distributed in a
region whose boundary is made by planar faces without any particular symmetry.
This type of geometrical body in the $d$-dimensional space is a polytope. The
presented result in the case of $d=3$ gives the conditions under which the
partition function is a polynomial in the volume, surface area, and edges
length of the confinement vessel. Equivalent results for the cases $d=1,2$ are
also obtained. Expressions for the coefficients of each monomial are explicitly
given using the cluster integral theory. Furthermore, the consequences of the
polynomial shape of the partition function on the thermodynamic properties of
the system, away from the so-called thermodynamic limit, is studied. Some
results are generalized to the $d$-dimensional case. The theoretical tools
utilized to analyze the structure of the partition functions are largely based
on integral geometry.


title: Hybrid Evolutionary Computation for Continuous Optimization

abstract:
  Hybrid optimization algorithms have gained popularity as it has become
apparent there cannot be a universal optimization strategy which is globally
more beneficial than any other. Despite their popularity, hybridization
frameworks require more detailed categorization regarding: the nature of the
problem domain, the constituent algorithms, the coupling schema and the
intended area of application. This report proposes a hybrid algorithm for
solving small to large-scale continuous global optimization problems. It
comprises evolutionary computation (EC) algorithms and a sequential quadratic
programming (SQP) algorithm; combined in a collaborative portfolio. The SQP is
a gradient based local search method. To optimize the individual contributions
of the EC and SQP algorithms for the overall success of the proposed hybrid
system, improvements were made in key features of these algorithms. The report
proposes enhancements in: i) the evolutionary algorithm, ii) a new convergence
detection mechanism was proposed; and iii) in the methods for evaluating the
search directions and step sizes for the SQP local search algorithm. The
proposed hybrid design aim was to ensure that the two algorithms complement
each other by exploring and exploiting the problem search space. Preliminary
results justify that an adept hybridization of evolutionary algorithms with a
suitable local search method, could yield a robust and efficient means of
solving wide range of global optimization problems. Finally, a discussion of
the outcomes of the initial investigation and a review of the associated
challenges and inherent limitations of the proposed method is presented to
complete the investigation. The report highlights extensive research,
particularly, some potential case studies and application areas.


title: Rigidity of smooth critical circle maps

abstract:
  We prove that any two $C^3$ critical circle maps with the same irrational
rotation number of bounded type and the same odd criticality are conjugate to
each other by a $C^{1+\alpha}$ circle diffeomorphism, for some universal
$\alpha>0$.


title:
The splitting in potential Crank-Nicolson scheme with discrete
  transparent boundary conditions for the Schr\"odinger equation on a
  semi-infinite strip

abstract:
  We consider an initial-boundary value problem for a generalized 2D
time-dependent Schrodinger equation (with variable coefficients) on a
semi-infinite strip. For the Crank-Nicolson-type finite-difference scheme with
approximate or discrete transparent boundary conditions (TBCs), the Strang-type
splitting with respect to the potential is applied. For the resulting method,
the unconditional uniform in time $L^2$-stability is proved. Due to the
splitting, an effective direct algorithm using FFT is developed now to
implement the method with the discrete TBC for general potential. Numerical
results on the tunnel effect for rectangular barriers are included together
with the detailed practical error analysis confirming nice properties of the
method.


title: Holographic Entanglement Entropy and Hidden Fermi surfaces

abstract:
  We prove that the purely classical gravity dual of Fermi and non-Fermi
liquids exist by employing the logarithmic behavior of entanglement entropy to
probe Fermi surfaces. For isotropic systems, the logarithmic behavior
originates only from UV-IR intermediate regions of the minimal area surface.
For anisotropic systems, the surfaces' configuration becomes largely modified
by spatial anisotropy and series of solutions exist. By imposing the null
energy condition we show that the specific heat behaves as $C\propto T^\alpha$
where $\alpha\leq1$, in both systems. In the end, we also present an effective
gravity modle for anisotropic background.


title:
Thermal Stability and Electrical Control of Magnetization of
  Heusler/Oxide Interface and Non-collinear Spin Transport of Its Junction

abstract:
  Towards next-generation spintronics devices, such as computer memories and
logic chips, it is necessary to satisfy high thermal stability, low-power
consumption and high spin-polarization simultaneously. Here, from
first-principles, we investigate thermal stability (both structure and
magnetization) and the electric field control of magnetic anisotropy on Co2FeAl
(CFA)/MgO. A phase diagram of structural thermal stability of the CFA/MgO
interface is illustrated. An interfacial perpendicular-anisotropy, coming from
the Fe-O orbital hybridization, provides high magnetic thermal stability and a
low stray field. We find an electric-field-induced giant modification of such
perpendicular-anisotropy via a great magnetoelectric effect (the anisotropy
energy coefficient beta~10-7 erg/V cm). Our spin electronic-structure and
non-collinear transport calculations indicate high spin-polarized interfacial
states and good magnetoresistance properties of CFA/MgO/CFA perpendicular
magnetic tunnel junctions.


title:
Nonlinear theory of intense laser-plasma interactions modified by
  vacuum-polarization effects

abstract:
  The classical nonlinear laser-plasma interaction theory is corrected. Given
the effects of vacuum polarization (induced by extreme laser) as nonlinear
media response, one-dimensional wave equations of a monochromatic laser field
are derived from the Heisenberg-Euler Lagrangian density and a derivative
correction with the first order quantum electrodynamic (QED) effects. A more
suitable model to formulate the interactions of extreme laser and
high-energy-density plasma is developed. In the results, the enhanced effect of
vacuum polarization will be discussed and shown.


title:
Nonasymptotic Probability Bounds for Fading Channels Exploiting Dedekind
  Zeta Functions

abstract:
  In this paper, new probability bounds are derived for algebraic lattice
codes. This is done by using the Dedekind zeta functions of the algebraic
number fields involved in the lattice constructions. In particular, it is shown
how to upper bound the error performance of a finite constellation on a
Rayleigh fading channel and the probability of an eavesdropper's correct
decision in a wiretap channel. As a byproduct, an estimate of the number of
elements with a certain algebraic norm within a finite hyper-cube is derived.
While this type of estimates have been, to some extent, considered in algebraic
number theory before, they are now brought into novel practice in the context
of fading channel communications. Hence, the interest here is in
small-dimensional lattices and finite constellations rather than in the
asymptotic behavior.


title:
Spin-torque effects in thermally assisted magnetization reversal: Method
  of statistical moments

abstract:
  Thermal fluctuations of nanomagnets driven by spin-polarized currents are
treated via the Landau-Lifshitz-Gilbert equation generalized to include both
the random thermal noise field and the Slonczewski spin-transfer torque term.
By averaging this stochastic (Langevin) equation over its realizations, the
explicit infinite hierarchy of differential-recurrence relations for
statistical moments (averaged spherical harmonics) is derived for arbitrary
demagnetizing factors and magnetocrystalline anisotropy for the generic
nanopillar model of a spin-torque device comprising two ferromagnetic strata
representing the free and fixed layers and a nonmagnetic conducting spacer all
sandwiched between two ohmic contacts. The influence of thermal fluctuations
and spin-transfer torques on relevant switching characteristics, such as the
stationary magnetization, the magnetization reversal time, etc., is calculated
by solving the hierarchy for wide ranges of temperature, damping, external
magnetic field, and spin-polarized current indicating new spin-torque effects
in the thermally assisted magnetization reversal comprising several orders of
magnitude. In particular, a pronounced dependence of the switching
characteristics on the directions of the external magnetic field and the spin
polarization exists.


title:
Penetration Deep into Tissues of Reactive Oxygen Species Generated in
  Floating-Electrode Dielectric Barrier Discharge (FE-DBD): in Vitro Agarose
  Gel Model Mimicking an Open Wound

abstract:
  In this manuscript we present an in vitro model based on agarose gel that can
be used to simulate a dirty, oily, bloody, and morphologically complex surface
of, for example, an open wound. We show this models effectiveness in simulating
depth of penetration of reactive species generated in plasma deep into tissue
of a rat and confirm the penetration depths with agarose gel model. We envision
that in the future such a model could be used to study plasma discharges (and
other modalities) and minimize the use of live animals: plasma can be optimized
on the agarose gel wound model and then finally verified using an actual wound.


title: Automorphism Groups of Hyperbolic Lattices

abstract:
  Based on the concept of dual cones introduced by J.Opgenorth we give an
algorithm to compute a generating system of the group of automorphisms of a
lattice endowed with a hyperbolic bilinear form.


title:
High energy characteristics of Neutron star low mass X-ray binaries as
  seen by INTEGRAL: the 4U 1722-30 case

abstract:
  We report here results on the long time behaviour of the variable source 4U
1722-30, obtained from INTEGRAL non-continuous observations carried out between
2003 and 2009. During this period 4U 1722-30 shows a general persistent
emission along with several bright outbursts resembling those of transient
X-ray sources/X-ray novae. However the source never switches into a real
quiescent state, with very weak or undetectable flux level, as it normally
occurs in transient sources. We compare here flux ratios and spectral state
variations measured during the different outbursts and highlight the peculiar
character of the 2008 outburst, for which we also propose a specific physical
explanation.


title: Interval edge estimation in SAR images

abstract:
  This paper considers edge interval estimation between two regions of a
Synthetic Aperture Radar (SAR) image which differ in texture. This is a
difficult task because SAR images are contaminated with speckle noise.
Different point estimation strategies under multiplicative noise are discussed
in the literature. It is important to assess the quality of such point
estimates and to also perform inference under a given confidence level. This
can be achieved through interval parameter estimation. To that end, we propose
bootstrap-based edge confidence interval. The relative merits of the different
inference strategies are compared using Monte Carlo simulation. The results
show that interval edge estimation can be used to assess the accuracy of an
edge point estimate. They also show that interval estimates can be quite
accurate and that they can indicate the absence of an edge. In order to
illustrate interval edge estimation, we also analyze a real dataset.


title:
Algebraicity of the zeta function associated to a matrix over a free
  group algebra

abstract:
  Following and generalizing a construction by Kontsevich, we associate a zeta
function to any matrix with entries in a ring of noncommutative Laurent
polynomials with integer coefficients. We show that such a zeta function is an
algebraic function.


title: Measuring stationarity in long-memory processes

abstract:
  In this paper we consider the problem of measuring stationarity in locally
stationary long-memory processes. We introduce an $L_2$-distance between the
spectral density of the locally stationary process and its best approximation
under the assumption of stationarity. The distance is estimated by a numerical
approximation of the integrated spectral periodogram and asymptotic normality
of the resulting estimate is established. The results can be used to construct
a simple test for the hypothesis of stationarity in locally stationary
long-range dependent processes. We also propose a bootstrap procedure to
improve the approximation of the nominal level and prove its consistency.
Throughout the paper, we will work with Riemann sums of a squared periodogram
instead of integrals (as it is usually done in the literature) and as a
by-product of independent interest it is demonstrated that the two approaches
behave differently in the limit.


title:
Frequency preference in two-dimensional neural models: a linear analysis
  of the interaction between resonant and amplifying currents

abstract:
  Many neuron types exhibit preferred frequency responses in their voltage
amplitude (resonance) or phase shift to subthreshold oscillatory currents, but
the effect of biophysical parameters on these properties is not well
understood. We propose a general framework to analyze the role of different
ionic currents and their interactions in shaping the properties of impedance
amplitude and phase in linearized biophysical models and demonstrate this
approach in a two-dimensional linear model with two effective conductances gL
and g1. We compute the key attributes of impedance and phase (resonance
frequency and amplitude, zero-phase frequency, selectivity, etc.) in the gL-g1
parameter space. Using these attribute diagrams we identify two basic
mechanisms for the generation of resonance: an increase in the resonance
amplitude as g1 increases while the overall impedance is decreased, and an
increase in the maximal impedance, without any change in the input resistance,
as the ionic current time constant increases. We use the attribute diagrams to
analyze resonance and phase of the linearizations of two biophysical models
that include resonant (Ih or slow potassium) and amplifying currents
(persistent sodium). In the absence of amplifying currents, the two models
behave similarly as the conductances of the resonant currents is increased
whereas, with the amplifying current present, the two models have qualitatively
opposite responses. This work provides a general method for decoding the effect
of biophysical parameters on linear membrane resonance and phase by tracking
trajectories, parametrized by the relevant biophysical parameter, in
pre-constructed attribute diagrams.


title:
Key rate for calibration robust entanglement based BB84 quantum key
  distribution protocol

abstract:
  We apply the approach of verifying entanglement, which is based on the sole
knowledge of the dimension of the underlying physical system to the
entanglement based version of the BB84 quantum key distribution protocol. We
show that the familiar one-way key rate formula holds already if one assumes
the assumption that one of the parties is measuring a qubit and no further
assumptions about the measurement are needed.


title:
Proposed Video Encryption Algorithm v/s Other Existing Algorithms: A
  Comparative Study

abstract:
  Securing multimedia data has become of utmost importance especially in the
applications related to military purposes. With the rise in development in
computer and internet technology, multimedia data has become the most
convenient method for military training. An innovative encryption algorithm for
videos compressed using H.264 was proposed to safely exchange highly
confidential videos. To maintain a balance between security and computational
time, the proposed algorithm shuffles the video frames along with the audio,
and then AES is used to selectively encrypt the sensitive video codewords.
Using this approach unauthorized viewing of the video file can be prevented and
hence this algorithm provides a high level of security. A comparative study of
the proposed algorithm with other existing algorithms has been put forward in
this paper to prove the effectiveness of the proposed algorithm.


title: Aharonov-Bohm conductance of a disordered single-channel quantum ring

abstract:
  We study the effect of weak disorder on tunneling conductance of a
single-channel quantum ring threaded by magnetic flux. We assume that
temperature is higher than the level spacing in the ring and smaller than the
Fermi energy. In the absence of disorder, the conductance shows sharp dips
(antiresonances) as a function of magnetic flux. We discuss different types of
disorder and find that the short-range disorder broadens antiresonances, while
the long-range one leads to arising of additional resonant dips. We demonstrate
that the resonant dips have essentially non-Lorentzian shape. The results are
generalized to account for the spin-orbit interaction which leads to splitting
of the disorder-broadened resonant dips, and consequently to coexisting of two
types of oscillations (both having the form of sharp dips): Aharonov-Bohm
oscillations with magnetic flux and Aharonov-Casher oscillations with the
strength of the spin-orbit coupling. We also discuss the effect of the Zeeman
coupling.


title: A geometric construction of generalized q-Schur algebras

abstract:
  We show that the algebras constructed in [Li10] and [Li12] are generalized
q-Schur algebras as defined in [D03]. This provides a geometric construction of
generalized q-Schur algebras in types A, D and E. We give a parameterization of
Nakajima's Lagrangian quiver variety of type D associated to a certain highest
weight.


title: Edge states versus diffusion in disordered graphene flakes

abstract:
  We study the localization properties of the wavefunctions in graphene flakes
with short range disorder, via the numerical calculation of the Inverse
Participation Ratio($IPR$) and it scaling which provides the fractal dimension
$D_{2}$. We show that the edge states which exist at the Dirac point of
ballistic graphene (no disorder) with zig-zag edges survive in the presence of
weak disorder with wavefunctions localized at the boundaries of the flakes. We
argue, that there is a strong interplay between the underlying destructive
interference mechanism of the honeycomb lattice of graphene leading to edge
states and the diffusive interference mechanism introduced by the short-range
disorder. This interplay results in a highly abnormal behavior, wavefunctions
are becoming progressively less localized as the disorder is increased,
indicated by the decrease of the average $\langle IPR\rangle$ and the increase
of $D_{2}$. We verify, that this abnormal behavior is absent for graphene
flakes with armchair edges which do not provide edge states.


title:
Relay Selection and Resource Allocation for Two Way DF-AF Cognitive
  Radio Networks

abstract:
  In this letter, the problem of optimal resource power allocation and relay
selection for two way relaying cognitive radio networks using half duplex
Decode and Forward (DF) and Amplify and Forward (AF) systems are investigated.
The primary and secondary networks are assumed to access the spectrum at the
same time, so that the interference introduced to the primary network caused by
the secondary network should be below a certain interference threshold. In
addition, a selection strategy between the AF and DF schemes is applied
depending on the achieved secondary sum rate without affecting the quality of
service of the primary network. A suboptimal approach based on a genetic
algorithm is also presented to solve our problem. Selected simulation results
show that the proposed suboptimal algorithm offers a performance close to the
performance of the optimal solution with a considerable complexity saving.


title: Transmon-phonon coupling of plasma oscillations and lattice vibrations

abstract:
  In the transmon qubit we expect from conservation of momentum and energy a
coupling between the plasma oscillations and the vibrations of the underlying
lattice. Specifically, the electron velocities and their kinetic energy density
are boosted by the underlying lattice vibrations. We consider this effect in a
representative transmon comprising two semi-circular superconducting charge
islands joined by a Josephson junction. In particular, we solve the Fourier
transform of a two-dimensional radial current density having inversion
symmetry. The resulting spectral density is ohmic but also scales quadratically
with the critical current I_c and logarithmically with the size of the
transmon: J(w) ~ I_c^2 w log(kR). We make positive-definite Born-Markov
approximations in a generalized Fermi's Golden Rule and estimate the
phonon-induced dephasing rate is negligible compared to current experiments.


title: A basis for the diagonally signed-symmetric polynomials

abstract:
  Let n>0 be an integer and let B_{n} denote the hyperoctahedral group of rank
n. The group B_{n} acts on the polynomial ring
Q[x_{1},...,x_{n},y_{1},...,y_{n}] by signed permutations simultaneously on
both of the sets of variables x_{1},...,x_{n} and y_{1},...,y_{n}. The
invariant ring M^{B_{n}}:=Q[x_{1},...,x_{n},y_{1},...,y_{n}]^{B_{n}} is the
ring of diagonally signed-symmetric polynomials. In this article we provide an
explicit free basis of M^{B_{n}} as a module over the ring of symmetric
polynomials on both of the sets of variables x_{1}^{2},..., x^{2}_{n} and
y_{1}^{2},..., y^{2}_{n} using signed descent monomials.


title:
Including fringe fields from a nearby ferromagnet in a percolation
  theory of organic magnetoresistance

abstract:
  Random hyperfine fields are essential to mechanisms of low-field
magnetoresistance in organic semiconductors. Recent experiments have shown that
another type of random field --- fringe fields due to a nearby ferromagnet ---
can also dramatically affect the magnetoresistance. A theoretical analysis of
the effect of these fringe fields is challenging, as the fringe field
magnitudes and their correlation lengths are orders of magnitude larger than
that of the hyperfine couplings. We extend a recent theory of organic
magnetoresistance to calculate the magnetoresistance with both hyperfine and
fringe fields present. This theory describes several key features of the
experimental fringe-field magnetoresistance, including the applied fields where
the magnetoresistance reaches extrema, the applied field range of large
magnetoresistance effects from the fringe fields, and the sign of the effect.


title: Calibrating the In-Medium Behavior of Quarkonia

abstract:
  Quarkonium production has been considered as a tool to study the medium
formed in high energy nuclear collisions, assuming that the formation of a hot
and dense environment modifies the production pattern observed in elementary
collisions. The basic features measured there are the relative fractions of
hidden to open heavy flavor and the relative fractions of the different hidden
heavy flavor states. Hence the essential question is if and how these
quantities are modified in nuclear collisions. We show how the relevant data
must be calibrated, i.e., what reference has to be used, in order to determine
this in a model-independent way.


title: Signatures of hermitian forms and "prime ideals" of Witt groups

abstract:
  In this paper a further study is made of $H$-signatures of hermitian forms,
introduced previously by the authors. It is shown that a tuple of reference
forms $H$ may be replaced by a single form and that the $H$-signature is
invariant under Morita equivalence of algebras with involution. The "prime
ideals" of the Witt group are studied, obtaining results that are analogues of
the classification of prime ideals of the Witt ring by Harrison and
Lorenz-Leicht. It follows that $H$-signatures canonically correspond to
morphisms into the integers.