AT4 - Localized self-gravitating field systems in the Einstein and alternatives theories of gravity |
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Speaker |
Maeda, Kei-ichi |
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Coauthors |
Katsuki Aoki |
| Talk Title |
Dark energy and dark matter in the ghost-free bigravity theory |
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Abstract |
We study dynamics of Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime based on the ghost-free bigravity theory. We find two stable attractors for spacetime with gtwinh dust matter fields: One is de Sitter accelerating universe and the other is matter dominated universe. A considerable number of initial data leads to de Sitter universe, although we also find matter dominated universe or spacetime with a future singularity for some initial data. The cosmic no-hair conjecture does not exactly hold, but the Lambda-CDM model is found naturally as an attractor. We also analyze the possibility for the twin matter fluid to be dark matter in gour world". Dark matter appears as the galactic missing mass, is required in the cosmic structure formation and is found in the cosmic pie (the content of the Universe). We show the bigravity theory can also explain those facts by twin matter fluid when the Compton wavelength of the massive graviton is shorter than a galactic scale. |
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