TY - JOUR

T1 - Emergent cosmology, inflation and dark energy

AU - Guendelman, Eduardo

AU - HERRERA APABLAZA, RAMON ALEJANDRO

AU - Labrana, Pedro

AU - Nissimov, Emil

AU - Pacheva, Svetlana

PY - 2015/1/1

Y1 - 2015/1/1

N2 - A new class of gravity–matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space–time manifold are studied in some detail. These models involve an additional R2(square of the scalar curvature) term as well as scalar matter field potentials of appropriate form so that the pertinent action is invariant under global Weyl-scale symmetry. Scale invariance is spontaneously broken upon integration of the equations of motion for the auxiliary volume-form degrees of freedom. After performing transition to the physical Einstein frame we obtain: (1) an effective potential for the scalar field with two flat regions which allows for a unified description of both early universe inflation as well as of present dark energy epoch; (2) for a definite parameter range the model possesses a non-singular “emergent universe” solution which describes an initial phase of evolution that precedes the inflationary phase; (3) for a reasonable choice of the parameters the present model conforms to the Planck Collaboration data.

AB - A new class of gravity–matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space–time manifold are studied in some detail. These models involve an additional R2(square of the scalar curvature) term as well as scalar matter field potentials of appropriate form so that the pertinent action is invariant under global Weyl-scale symmetry. Scale invariance is spontaneously broken upon integration of the equations of motion for the auxiliary volume-form degrees of freedom. After performing transition to the physical Einstein frame we obtain: (1) an effective potential for the scalar field with two flat regions which allows for a unified description of both early universe inflation as well as of present dark energy epoch; (2) for a definite parameter range the model possesses a non-singular “emergent universe” solution which describes an initial phase of evolution that precedes the inflationary phase; (3) for a reasonable choice of the parameters the present model conforms to the Planck Collaboration data.

KW - Flat regions of scalar potential

KW - Global Weyl-scale symmetry spontaneous breakdown

KW - Modified gravity theories

KW - Non-Riemannian volume forms

KW - Non-singular origin of the universe

UR - http://www.scopus.com/inward/record.url?scp=84921897471&partnerID=8YFLogxK

U2 - 10.1007/s10714-015-1852-1

DO - 10.1007/s10714-015-1852-1

M3 - Article

AN - SCOPUS:84921897471

VL - 47

JO - General Relativity and Gravitation

JF - General Relativity and Gravitation

SN - 0001-7701

IS - 2

ER -