Next Article in Journal
Decay Kinetics of CeF3 under VUV and X-ray Synchrotron Radiation
Next Article in Special Issue
Gas of Baby Universes in JT Gravity and Matrix Models
Previous Article in Journal / Special Issue
Highly Entangled Spin Chains and 2D Quantum Gravity
Article

Some Cosmological Solutions of a New Nonlocal Gravity Model

1
Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11158 Belgrade, Serbia
2
Institute of Physics, University of Belgrade, 11080 Belgrade, Serbia
3
Mathematical Institute, Serbian Academy of Sciences and Arts, 11000 Belgrade, Serbia
4
Departamento de Física and Centro de Matemática e Aplicações, Universidade da Beira Interior, 6200 Covilhã, Portugal
5
Teacher Education Faculty, University of Belgrade, Kraljice Natalije 43, 11000 Belgrade, Serbia
*
Author to whom correspondence should be addressed.
Symmetry 2020, 12(6), 917; https://doi.org/10.3390/sym12060917
Received: 28 April 2020 / Revised: 12 May 2020 / Accepted: 20 May 2020 / Published: 2 June 2020
(This article belongs to the Special Issue Selected Papers: 10th Mathematical Physics Meeting)
In this paper, we investigate a nonlocal modification of general relativity (GR) with action S = 1 16 π G [ R 2 Λ + ( R 4 Λ ) F ( ) ( R 4 Λ ) ] g d 4 x , where F ( ) = n = 1 + f n n is an analytic function of the d’Alembertian □. We found a few exact cosmological solutions of the corresponding equations of motion. There are two solutions which are valid only if Λ 0 , k = 0 , and they have no analogs in Einstein’s gravity with cosmological constant Λ . One of these two solutions is a ( t ) = A t e Λ 4 t 2 , that mimics properties similar to an interference between the radiation and the dark energy. Another solution is a nonsingular bounce one a ( t ) = A e Λ t 2 . For these two solutions, some cosmological aspects are discussed. We also found explicit form of the nonlocal operator F ( ) , which satisfies obtained necessary conditions. View Full-Text
Keywords: nonlocal gravity; cosmological solutions; radiation; dark energy nonlocal gravity; cosmological solutions; radiation; dark energy
MDPI and ACS Style

Dimitrijevic, I.; Dragovich, B.; Koshelev, A.S.; Rakic, Z.; Stankovic, J. Some Cosmological Solutions of a New Nonlocal Gravity Model. Symmetry 2020, 12, 917. https://doi.org/10.3390/sym12060917

AMA Style

Dimitrijevic I, Dragovich B, Koshelev AS, Rakic Z, Stankovic J. Some Cosmological Solutions of a New Nonlocal Gravity Model. Symmetry. 2020; 12(6):917. https://doi.org/10.3390/sym12060917

Chicago/Turabian Style

Dimitrijevic, Ivan, Branko Dragovich, Alexey S. Koshelev, Zoran Rakic, and Jelena Stankovic. 2020. "Some Cosmological Solutions of a New Nonlocal Gravity Model" Symmetry 12, no. 6: 917. https://doi.org/10.3390/sym12060917

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop