Infra-red effects of Non-linear sigma model in de Sitter space
Sep, 2011
39 pages
Published in:
- Phys.Rev.D 85 (2012) 044062
e-Print:
- 1109.4892 [hep-th]
Report number:
- KEK-TH-1492
View in:
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Abstract: (arXiv)
We extend our investigation on a possible de Sitter symmetry breaking mechanism in non-linear sigma models. The scale invariance of the quantum fluctuations could make the cosmological constant time dependent signaling the de Sitter symmetry breaking. To understand such a symmetry breaking mechanism, we investigate the energy-momentum tensor. We show that the leading infra-red logarithms cancel to all orders in perturbation theory in a generic non-linear sigma model. When the target space is an N sphere, the de Sitter symmetry is preserved in the large N limit. For a less symmetric target space, the infra-red logarithms appear at the three loop level. However there is a counter term to precisely cancel it. The leading infra-red logarithms do not cancel for higher derivative interactions. We investigate such a model in which the infra-red logarithms first appear at the three loop level. A nonperturbative investigation in the large N limit shows that they eventually grow as large as the one loop effect.Note:
- 39pages
- 05.70.Ln
- 95.36.+x
- 04.62.+v
- sigma model: nonlinear
- space: de Sitter
- cosmological constant: time dependence
- tensor: energy-momentum
- symmetry breaking
- expansion 1/N
- perturbation theory
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