Seminars and Journal Clubs
Toward a unified description of dark matter and dark energy from the Abnormally Weighting Energy (AWE) hypothesis
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Europe/Brussels
fynu seminar room, 3rd floor, Tower E
fynu seminar room, 3rd floor, Tower E
Description
In this seminar, we introduce the Abnormally Weighting Energy (AWE) hypothesis in which the dark sector of cosmology is assumed to violate the weak equivalence principle (WEP) on cosmological scales. The consequent violation of the strong equivalence principle for ordinary matter explains cosmic acceleration by an increasingly stronger gravitational coupling to the background expansion. This explanation is formulated in terms of a tensor-scalar theory of gravitation without WEP for which there exists a revisited convergence mechanism toward general relativity. It can also be viewed as a Mach-Dirac principle where the variation of the mass of the Dark Matter particles induces a variation of baryon's gravitational coupling. In this new cosmological framework, general relativity is satisfied at low scales, as WEP violation depends on the ratio of the ordinary matter over dark matter densities, but at large scales, we obtain a general relativity-like theory with a different value of the gravitational coupling.
The consequent dark energy mechanism exhibits awesome properties:
(i) it does not require any violation of the strong energy condition p<-\rho c2/3,
(ii) it offers a natural way-out of the coincidence problem thanks to the non-minimal couplings to gravitation,
(iii) it accounts fairly for supernovae data from various very simple couplings and with density parameters very close to the ones of the concordance model LCDM, therefore suggesting an explanation to its remarkable adequacy.
Finally, (iv) this mechanism ends up in the future with an Einstein-de Sitter expansion regime.
But, most of all, the AWE hypothesis can be hoped to reduce dark energy to a new property of gravitation: the anomalous gravity of dark matter.
[1] A. Füzfa, J.-M. Alimi, “Non-Abelian Einstein-Born-Infeld-Dilaton Cosmology”, Phys.Rev. D73 (2006) 023520, gr-qc/0511090
[2] A. Füzfa, J.-M. Alimi, “Dark Energy as a Born-Infeld Gauge Interaction Violating the Equivalence Principle”, Phys. Rev. Lett. 97, 061301 (2006), astro-ph/0604517
[3] A. Füzfa, J.-M. Alimi, “Toward a Unified Description of Dark Energy and Dark Matter from the AWE Hypothesis”, submitted to Phys. Rev. D, astro-ph/0702478