33,843 research outputs found
Influence functional approach to decoherence during Inflation
We show how the quantum to classical transition of the cosmological
fluctuations produced during inflation can be described by means of the
influence functional and the master equation. We split the inflaton field into
the system-field (long-wavelength modes), and the environment, represented by
its own short-wavelength modes. We compute the decoherence times for the
system-field modes and compare them with the other time scales of the model.Comment: 6 pages, no figures. Contributed talk to the Second International
Workshop DICE2004, Piombino, Ital
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Globalising Mental Health or Pathologising the Global South? Mapping the Ethics, Theory and Practice of Global Mental Health
A Study of the Impact of the Phividec Industrial Estate
This article is a product of a nine-month training and application program implemented by the micro component of the Economic and Social Impact Analysis/Women in Development (ESIA/WID) and the Food Systems Program of the East-West Center Resource Systems Institute (RSI). Since the industrial estate has yet to be completed, this article presents an impact evaluation of the project based on its accomplishment on the basis of its expected full benefits. This is in the hope of providing a foundation for policy strengthening and alteration.industry sector, infrastructure, survey method, impact analysis
Morse index and multiplicity of min-max minimal hypersurfaces
The Min-max Theory for the area functional, started by Almgren in the early
1960s and greatly improved by Pitts in 1981, was left incomplete because it
gave no Morse index estimate for the min-max minimal hypersurface.
We advance the theory further and prove the first general Morse index bounds
for minimal hypersurfaces produced by it. We also settle the multiplicity
problem for the classical case of one-parameter sweepouts.Comment: Cambridge Journal of Mathematics, 4 (4), 463-511, 201
Existence of infinitely many minimal hypersurfaces in positive Ricci curvature
In the early 1980s, S. T. Yau conjectured that any compact Riemannian
three-manifold admits an infinite number of closed immersed minimal surfaces.
We use min-max theory for the area functional to prove this conjecture in the
positive Ricci curvature setting. More precisely, we show that every compact
Riemannian manifold with positive Ricci curvature and dimension at most seven
contains infinitely many smooth, closed, embedded minimal hypersurfaces.
In the last section we mention some open problems related with the geometry
of these minimal hypersurfaces.Comment: 34 pages, to appear in Inventiones Mathematica
Correction to the geometric phase by structured environments: the onset of non-Markovian effects
We study the geometric phase of a two-level system under the presence of a
structured environment, particularly analysing its correction with the ohmicity
parameter and the onset of non-Markovianity. We firstly examine the system
coupled to a set of harmonic oscillators and studied the decoherence factor as
function of the environment's ohmicity parameter. Secondly, we propose the
two-level system coupled to a non-equilibrium environment, and show that these
environments display non-Markovian effects for all values of the ohmicity
parameter. The geometric phase of the two-level system is therefore computed
under the presence of both types of environment. The correction to the unitary
geometric phase is analysed in both, Markovian and non-Markovian regimes. Under
Markovian environments, the correction induced on the system's phase is mainly
ruled by the coupling constant between the system and the environment, while in
the non-Markovian regime, memory effects seem to trigger a significant
correction to the unitary geometric phase. The result is significant to the
quantum information processing based on the geometric phase in quantum open
systemsComment: 7 figures. Accepted for publication in Phys. Rev. A. arXiv admin
note: text overlap with arXiv:1303.493
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