ΛCDM as a Noether symmetry in cosmology
Abstract
The standard ΛCDM model of cosmology is formulated as a simple modified gravity coupled to a single scalar field (“darkon”) possessing a nontrivial hidden nonlinear Noether symmetry. The main ingredient in the construction is the use of the formalism of nonRiemannian spacetime volumeelements. The associated Noether conserved current produces stressenergy tensor consisting of two additive parts — dynamically generated dark energy and dark matter components noninteracting among themselves. Noether symmetry breaking via an additional scalar “darkon” potential introduces naturally an interaction between dark energy and dark matter. The correspondence between the ΛCDM model and the present “darkon” Noether symmetry is exhibited up to linear order with respect to gravitymatter perturbations. With the Cosmic Chronometers (CC) and the Redshift Space Distortion (RSD) datasets, we study an example for the “darkon” potential that breaks the Noether symmetry and we show that the preservation of this symmetry yields a better fit.
 Publication:

International Journal of Modern Physics D
 Pub Date:
 2020
 DOI:
 10.1142/S0218271820501047
 arXiv:
 arXiv:2003.13146
 Bibcode:
 2020IJMPD..2950104B
 Keywords:

 Unified dark energy dark matter;
 Noether symmetry;
 cosmology;
 supernova data;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology
 EPrint:
 10 pages, 1 figure, accepted in IJMPD