3,461 research outputs found
Quantum Gravity and the Large Scale Anomaly
The spectrum of primordial perturbations obtained by calculating the quantum
gravitational corrections to the dynamics of scalar perturbations is compared
with Planck 2013 and BICEP2/{\it Keck Array} public data. The quantum
gravitational effects are calculated in the context of a Wheeler-De Witt
approach and have quite distinctive features. We constrain the free parameters
of the theory by comparison with observations.Comment: 17 pages, 3 figures; the analysis has been updated with the combined
Planck-BICEP2/Keck Array public data. Final version, accepted for publication
in JCA
Inflation and Quantum Gravity in a Born-Oppenheimer Context
A general equation, describing the lowest order corrections coming from
quantum gravitational effects to the spectrum of cosmological scalar
fluctuations is obtained. These corrections are explicitly estimated for the
case of a de Sitter evolution.Comment: 13 pages, no figures. Final version, accepted for publication in PL
Signatures of Quantum Gravity in a Born-Oppenheimer Context
We solve a general equation describing the lowest order corrections arising
from quantum gravitational effects to the spectrum of cosmological
fluctuations. The spectra of scalar and tensor perturbations are calculated to
first order in the slow roll approximation and the results are compared with
the most recent observations. The slow roll approximation gives qualitatively
new quantum gravitational effects with respect to the pure de Sitter case.Comment: 19 pages, 2 figures; final version accepted for publication in PL
Processes of Territorial Transformation: Autopoietic Systems in Planning and the Theory of Chaos
The accelerated observer with back-reaction effects
The quantum mechanical evolution of an accelerated extended detector coupled
to a massless scalar field is exhibited and the back-reaction due to emission
or absorption processes computed at first order in the change of the detector's
mass and acceleration. An analogy with black hole evaporation is found and
illustrated.Comment: 7 pages, LaTeX, no figure
The accelerated observer and quantum effects
An extended monopole detector at constant acceleration coupled to a massless
scalar field is allowed to evolve quantum mechanically. It is found that while
in the classical, followed by the point particle, limit the usual result Unruh
effect is recovered, in the point particle (before the classical) limit the
detector decouples from the scalar field and therefore the effect disappears.Comment: Plain Tex, 10 page
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