SÉMINAIRE DU GRECO
"Weyl anomalies and cosmology" |
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A. Dabholkar |
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I will discuss effects of Weyl anomalies arising from renormalization of composite operators on gravitational dynamics on cosmological scales. I will describe a two-dimensional model of gravity which captures some of the essential features of higher dimensional gravity and in which these anomalies can be computed from first principles with relative ease. The resulting dynamics is described by a coordinate-invariant but nonlocal quantum effective action. The cosmological solutions of the equations of motion for an isotropic and homogenous universe exhibit a slow decay of vacuum energy and power law expansion, providing a new mechanism for the relaxation of the cosmological constant. I’ll conclude with a discussion of the possible ways for embedding this mechanism in a realistic four-dimensional cosmological scenario. The talk will be based on arXiv:1511.05342 arXiv:1511.07450 arXiv:1512.03275 |
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lundi 15 février 2016 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
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