TY - JOUR
T1 - Emergent cosmology, inflation and dark energy
AU - Guendelman, Eduardo
AU - Herrera, Ramón
AU - Labrana, Pedro
AU - Nissimov, Emil
AU - Pacheva, Svetlana
N1 - Funding Information:
We express our gratitude to Alexander Kaganovich for collaboration at the initial stage of this work []. We are thankful to Alexei Starobinsky, Marek Szydlowski, Martin Cederwall and Lilia Anguelova for instructive discussions. We are indebted to the referee for his constructive suggestions to improve the present work. E.G., E.N. and S.P. gratefully acknowledge support of our collaboration through the academic exchange agreement between the Ben-Gurion University in Beer-Sheva, Israel, and the Bulgarian Academy of Sciences. R.H. was supported by Comisión Nacional de Ciencias y Tecnología of Chile through FONDECYT Grant 1130628 and DI-PUCV 123.724. P.L. was supported by Dirección de Investigación de la Universidad del Bío-Bío through grants GI121407/VBC and 141407 3/R. S.P. has received partial support from European COST action MP-1210.
Publisher Copyright:
© 2015, Springer Science+Business Media New York.
PY - 2015/2
Y1 - 2015/2
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 -