Abstract:
Despite remarkable theoretical properties and numerous phenomenological predictions with confirmations, General Relativity (GR) is not a final theory of gravity. Problems mainly come from quantum gravity, astrophysics and cosmology. Therefore, there are many attempts to appropriately extend GR. In this talk, I consider a nonlocal gravity theory and its cosmological solutions. In particular, I investigate nonlocal models, where nonlocality is presented by an analytic function of the d’Alembert operator. Some exact vacuum cosmological solutions of the corresponding equations of motion will be presented. We pay special attention to the cosmological solution which mimics dark matter and dark energy. Computed cosmological parameters are in good agreement with cosmological observations. Details can be found in our recent papers [1], [2] and references therein.

I. Dimitrijevic, B. Dragovich, A. S. Koshelev, Z. Rakic and J. Stankovic, “Cosmological solutions of a nonlocal square root gravity”, Phys. Lett. B, 797 (2019), 134848, 5 pp., arXiv: 1906.07560 [gr-qc]

I. Dimitrijevic, B. Dragovich, A. S. Koshelev, Z. Rakic and J. Stankovic, “Some cosmological solutions of a new nonlocal gravity model”, Symmetry, 12 (2020), 917, arXiv: 2006.16041 [gr-qc]