Séminaire / Seminar GReCO |
| « Dark energy and inhomogeneity » |
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Chris Clarkson |
| I consider some of the issues we face in trying to understand dark energy. I discuss how the averaging problem confuses our potential understanding of dark energy by considering the backreaction from density perturbations to second-order in the concordance model: this effect leads to at least a 10% change in the observed value of the deceleration parameter, and could be significantly higher. Large Hubble-scale inhomogeneity has not been investigated in much detail, and could conceivably be the cause of apparent cosmic acceleration. I discuss void models which defy the Copernican principle in our Hubble patch, and describe how we can potentially rule out these models. |
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jeudi 28 avril 2011 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |