Cosmological branes and macroscopic extra dimensions
A.O. Barvinskii
Lebedev Physical Institute, Russian Academy of Sciences, Leninsky prosp. 53, Moscow, 119991, Russian Federation
The idea of adding extra dimensions to the physical
world-thus making the observable universe a timelike surface
(or brane) embedded in a higher-dimensional space-time — is
briefly reviewed, which is believed to hold serious promise for
solving fundamental problems concerning the hierarchy of physical interactions and the cosmological constant. Brane localization of massless gravitons is discussed as a mechanism leading
to the effective four-dimensional Einstein gravity theory on the
brane in the low-energy limit. It is shown that this mechanism is
a corollary of the AdS/CFT correspondence principle wellknown from string theory. Inflation and other cosmological
evolution scenarios induced by the local and nonlocal structures of the effective action of the gravitational brane are
considered, as are the effects that enable the developing gravitational-wave astronomy to be used in the search for extra
dimensions. Finally, a new approach to the cosmological constant and cosmological acceleration problems is discussed,
which involves variable local and nonlocal gravitational ’constants’ arising in the infrared modifications of the Einstein
theory that incorporate brane-induced gravity models and models of massive gravitons.
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