2024/04/20 by Bhattacharya, Kaushik, Dey, Dipanjan, Saha, Priyanka
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc)
paper · doi:10.48550/arxiv.2404.13332
It is known that in Friedmann-Lemaitre-Robertson-Walker cosmology one has more number of dynamical equations, compared to the number of unknown variables. This fact makes some equations redundant. The situation becomes complicated because all the relevant differential equations in cosmology are not of the same order. In this article we study the fate of the redundant equations. We show that this redundancy is inevitable in general relativity and a modern modification of gravity, called f(R) gravity. It is shown that this redundancy predicts a special role to one of the Friedmann equations, which constrains the initial values of the problem. It is shown that the initial constraint condition itself evolves with time. Our method of analyzing the dynamical structure of the theories relies on an operational approach and can be generalized further.