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Speaker |
Sussman, Roberto |
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Talk Title |
Analytic and numerical relations among back-reaction, effective acceleration, scalar averages and quasi-local energy in LTB models |
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Abstract |
The introduction of suitably defined quasi-local scalar variables leads to new insights and theoretically appealing connections on the dynamics of LTB (Lemaitre-Tolman-Bondi) dust models. These variables lead to a generalization of Buchert's scalar averaging formalism and allow us to obtain general analytic statements on the existence of back-reaction terms and an effective acceleration that would mimic dark energy. Interesting theoretical connections between the gradients of local and quasi-local energies and the existence of an effective acceleration follow from the evolution equations of averaged and quasi-local dynamical quantities. All these results can be useful in a numerical examination of these effects and can be easily generalized to the quasi-spherical Szekeres models and to LTB or Szkeres models whose sources are other than dust. |
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Talk view |
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