30,645 research outputs found
Non-transitive maps in phase synchronization
Concepts from the Ergodic Theory are used to describe the existence of
non-transitive maps in attractors of phase synchronous chaotic systems. It is
shown that for a class of phase-coherent systems, e.g. the sinusoidally forced
Chua's circuit and two coupled R{\"o}ssler oscillators, phase synchronization
implies that such maps exist. These ideas are also extended to other coupled
chaotic systems. In addition, a phase for a chaotic attractor is defined from
the tangent vector of the flow. Finally, it is discussed how these maps can be
used to real time detection of phase synchronization in experimental systems
Toward a Holistic, Intercultural, and Polyphonic Perspective on Health Care: A Brief Prologue to the Paper Titled “Understanding the Personalistic Aspects of Jola Ethnomedicine.”
As a prologue to the paper titled “Understanding the Personalistic Aspects of Jola Ethnomedicine,” the present essay provides a brief anthropologico-philosophical reflection, starting with classic Roman philosopher Seneca and his dictum that “each passing day we die,” and continuing on to the profound existential questions pondered by more contemporary thinkers, including Heidegger and Levinas, about life, death, being, time, totality, and infinity. These agonically deep questions are intimately related to the universal human angst about health, illness, and death and the seeking of a restoration to a functional corporal and mental harmony and well-being through various means and methods, whether based on traditional religious or mythical beliefs and practices or on more modern medical practices. This essay also provides a diachronic philological analysis of the evolution of the word “health” in various languages and its age- old semantic connections to the idea of the “holly” and the “sacred.” These semantic roots lead the author to define health as a “holistic, cosmic, integral, and sacred state of dynamic harmony.
Moduli Spaces of Abelian Vortices on Kahler Manifolds
We consider the self-dual vortex equations on a positive line bundle L --> M
over a compact Kaehler manifold of arbitrary dimension. When M is simply
connected, the moduli space of vortex solutions is a projective space. When M
is an abelian variety, the moduli space is the projectivization of the
Fourier-Mukai transform of L. We extend this description of the moduli space to
the abelian GLSM, i.e. to vortex equations with a torus gauge group acting
linearly on a complex vector space. After establishing the Hitchin-Kobayashi
correspondence appropriate for the general abelian GLSM, we give explicit
descriptions of the vortex moduli space in the case where the manifold M is
simply connected or is an abelian variety. In these examples we compute the
Kaehler class of the natural L^2-metric on the moduli space. In the simplest
cases we compute the volume and total scalar curvature of the muduli space.
Finally, we note that for abelian GLSM the vortex moduli space is a
compactification of the space of holomorphic maps from M to toric targets, just
as in the usual case of M being a Riemann surface. This leads to various
natural conjectures, for instance explicit formulae for the volume of the space
of maps CP^m --> CP^n.Comment: v2: 48 pages; significant changes; description of the vortex moduli
spaces of the GLSM extended to allow general values of the parameters, beyond
the generic values of v
Vortex equations in abelian gauged sigma-models
We consider nonlinear gauged sigma-models with Kahler domain and target. For
a special choice of potential these models admit Bogomolny (or self-duality)
equations -- the so-called vortex equations. We find the moduli space and
energy spectrum of the solutions of these equations when the gauge group is a
torus T^n, the domain is compact, and the target is C^n or CP^n. We also obtain
a large family of solutions when the target is a compact Kahler toric manifold.Comment: v2: 60 pages, more details than in CMP versio
HST/FOS Time-resolved spectral mapping of IP Pegasi at the end of an outburst
We report an eclipse mapping analysis of time-resolved ultraviolet
spectroscopy covering three eclipses of the dwarf nova IP Pegasi on the late
decline of the 1993 May outburst. The eclipse maps of the first run show
evidence of one spiral arm, suggesting that spiral structures may still be
present in the accretion disc 9 days after the onset of the outburst. In the
spatially resolved spectra the most prominent lines appear in emission at any
radius, being stronger in the inner disc regions. The spectrum of the gas
stream is clearly distinct from the disc spectrum in the intermediate and outer
disc regions, suggesting the occurrence of gas stream overflow. The full width
half maximum of C IV is approximately constant with radius, in contrast to the
expected law for a gas in Keplerian orbits. This line
probably originates in a vertically extended region (chromosphere + disc wind).
The uneclipsed component contributes % of the flux in C IV in the
first run, and becomes negligible in the remaining runs. We fit stellar
atmosphere models to the spatially resolved spectra. The radial run of the disc
color temperature for the three runs is flatter than the expected
law for steady-state optically thick discs models, with
K in the inner regions and K in the outer disc
regions. The solid angles that result from the fits are smaller than expected
from the parameters of the system. The radial run of the solid angle suggests
that the disc is flared in outburst, and decreases in thickness toward the end
of the outburst.Comment: 14 pages, 14 figures, in press in Astronomy & Astrophysic
Options and Efficiency in Multiperiod Security Markets
We extend the result of Ross (1976) that European options generate complete markets from the single-period to a multiperiod setting. We find that multiperiod European options on a trading strategy generate dynamic completeness for every arbitrage-free price process, provided that the trading strategy has non-negative terminal dividends and separates states at the terminal date. Furthermore, we show that if the uncertainty and information structure in an economy are such that the number of immediate successors of every non-terminal event is non-decreasing over time, then multiperiod European options on a trading strategy generate dynamic completeness for almost every arbitrage-free price process under a significantly weaker condition on the trading strategy's terminal dividends. This condition requires the trading strategy to have non- negative terminal dividends and to separate states at the terminal date conditional on the information available at the previous date. Finally, we examine the minimum number of options generating dynamic completeness for almost every arbitrage-free price process.
A pressão coronária (às vezes) mente. . .
Comment on:
Comparative analysis of fractional flow reserve and instantaneous wave-free ratio: Results of a five-year registry. [Rev Port Cardiol. 2018]info:eu-repo/semantics/publishedVersio
- …