(adsbygoogle = window.adsbygoogle || []).push({}); QC test idea--Physical Review D

This paper is to appear in Phys. Rev. D. I don't know when, just saw the announcement yesterday.

http://arxiv.org/abs/astro-ph/0703566

Thermal fluctuations in loop cosmology

Joao Magueijo1,2,3, Parampreet Singh4,1

1 Perimeter Institute for Theoretical Physics, 31 Caroline St N, Waterloo N2L 2Y5, Canada

2 Canadian Institute for Theoretical Astrophysics, 60 St George St, Toronto M5S 3H8, Canada

3 Theoretical Physics Group, Imperial College, Prince Consort Road, London SW7 2BZ, England

4 Institute for Gravitational Physics and Geometry, The Pennsylvania State University, University Park, PA 16802, USA

"Quantum gravitational effects in loop quantum cosmology lead to a resolution of the initial singularity and have the potential to solve the horizon problem and generate a quasi scale-invariant spectrum of density fluctuations. We consider loop modifications to the behavior of the inverse scale factor below a critical scale in closed models and assume a purely thermal origin for the fluctuations.

... to more fully work out this complex aspect of loop cosmology, since the full picture would not only fix the free parameters of the theory, but also provide a model for anon-inflationary, thermal origin for the structures of the Universe."

they are talking about an alternative solution to the horizon probem and structure problemsthat does not require imagining inflation scenariosand invoking an 'inflaton' scalar field. Another way to refer to an initial inflation scenario phase is as a "deSitter phase". Here is an exerpt from the introduction:

"The possibility that primordial thermal fluctuations might seed the structure of our Universe is an intriguing alternative to quantum fluctuations in a deSitter phase...

Unfortunately a number of obstacles present themselves to such an enterprise. Firstly any thermal scenario should necessarily be based on a [non-inflationary] solution of the horizon problem. This is so that the assumption of thermalization itself makes sense: ... A number of solutions to the horizon problem have been proposed... and in this paper we use in effect a combination of two..."

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# QC test idea-Physical Review D

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