2015/05/28 by Eduardo Guendelman, Emil Nissimov, Svetlana Pacheva · 1 citation
Physics and Astronomy · #gr-qc #hep-th
published as Bulgarian Journal of Physics 42 (2015) 14-27 · 14 pages, invited talk at the Memorial "Matey Mateev Symposium", April 2015, https://indico.cern.ch/event/359644/, partially based on arxiv:1504.01031 and arxiv:1408.5344v4, to appear in Bulgarian Journal of Physics, vol.42 (2015)
arxiv created 2015/05/28 · arxiv updated 2016/11/29
Employing alternative spacetime volume-forms (generally-covariant integration measure densities) independent of the pertinent Riemannian spacetime metric have profound impact in general relativity. Although formally appearing as "pure-gauge" dynamical degrees of freedom they trigger a number of remarkable physically important phenomena such as: (i) new mechanism of dynamical generation of cosmological constant; (ii) new type of "quintessential inflation" scenario in cosmology; (iii) non-singular initial "emergent universe" phase of cosmological evolution preceding the inflationary phase; (iv) new mechanism of dynamical spontaneous breakdown of supersymmetry in supergravity; (v) gravitational electrovacuum "bags". We study in some detail the properties, together with their canonical Hamiltonian formulation, of a class of generalized gravity-matter models built with two independent non-Riemannian volume-forms and discuss their implications in cosmology.