Observational backreaction in discrete black holes lattice cosmological models
Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, 180 Siwangting Road, 225002, Yangzhou City, Jiangsu Province, China
2 School of Aeronautics and Astronautics, Shanghai Jiao Tong University, 200240, Shanghai, China
3 Department of Physics, Stockholm University, 106 91, Stockholm, Sweden
Accepted: 8 December 2020
Published online: 5 January 2021
Applying the Sachs formalism, the optical properties encoded in the distance modulus are studied along curves exhibiting local rotational symmetry for some closed inhomogeneous cosmological models whose mass content is discretized by Schwarzschild-like sources. These models may challenge the concordance model in its use of the distance modulus data of type Ia supernovae, because they do not violate any energy condition. This result relies only on the symmetry properties considered, and not on the way in which the mass is discretized. The models with different number of sources are then compared among themselves and with a Friedmann–Lemaitre–Robertson–Walker model with the same total mass content by introducing a compactness parameter. The analysis shows that observational backreaction occurs because increasing the number of sources the features of a universe with a continuous matter distribution are not recovered. Our models are shown to exhibit a non-trivial relationship between kinematical, dynamical and observational backreactions, the kinematical one being asymptotically decreasing while the latter two are present. Furthermore, the electric part of the Weyl tensor contributes to the luminosity distance by affecting the evolution of the scale factor, while the magnetic part has an indirect role by affecting only the evolution of the former.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021