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**"APS Physics" view of pre-inflation cosmology article**

The APS has an online periodical that publishes "Viewpoints" on current research, for instance http://physics.aps.org/articles/v5/142

is an interpretive explanatory viewpoint, written for non-specialists,

on the article by Agullo Ashtekar Nelson published last month in Physical Review Letters.

This is on geometry&matter fluctuations in the PRE-INFLATION era. Basically it extends the conventional inflation analysis back further in time, where the conventional analysis is not valid because it is set on a (singular) classical space-time.

There is also a write-up of the Agullo et al work in the January 2013

**SciAm**

by Davide Castelvecchi.

Here's the PRL article (they made it a "featured article" with free access)

http://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.109.251301

It is also available on arxiv, along with a 50 page paper giving technical detail on which the PRL Letter is based.

short PRL article preprint: http://arxiv.org/abs/1209.1609

50 page article: http://arxiv.org/abs/1211.1354

==quote 1211.1354==

An Extension of the Quantum Theory of Cosmological Perturbations to the Planck Era

Ivan Agullo, Abhay Ashtekar, William Nelson

(Submitted on 6 Nov 2012)

Cosmological perturbations are generally described by quantum fields on (curved but) classical space-times. While this strategy has a large domain of validity, it can not be justified in the quantum gravity era where curvature and matter densities are of Planck scale. Using techniques from loop quantum gravity, the standard theory of cosmological perturbations is extended to overcome this limitation. The new framework sharpens conceptual issues by distinguishing between the true and apparent trans-Planckian difficulties and provides sufficient conditions under which the true difficulties can be overcome within a quantum gravity theory. In a companion paper, this framework is applied to the standard inflationary model, with interesting implications to theory as well as observations.

Comments: 50 pages, no figures. This is first of the two detailed papers on which arXiv 1209.1609 (PRL at press) is based

==endquote==

It's nice to see pre-inflation cosmology becoming increasingly visible in science media.

In case anyone wants, here's the SciAm link:

http://www.scientificamerican.com/a...-einsteins-relativity-universes-first-moments

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