New Cosmological Solutions of a Nonlocal Gravity Model
A nonlocal gravity model (2) was introduced and considered recently, and two exact cosmological solutions in flat space were presented. The first solution is related to some radiation effects generated by nonlocal dynamics on dark energy background, while the second one is a nonsingular time symmetr...
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MDPI AG
2021-12-01
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| Series: | Symmetry |
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| Online Access: | https://www.mdpi.com/2073-8994/14/1/3 |
| _version_ | 1797490159017525248 |
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| author | Ivan Dimitrijevic Branko Dragovich Zoran Rakic Jelena Stankovic |
| author_facet | Ivan Dimitrijevic Branko Dragovich Zoran Rakic Jelena Stankovic |
| author_sort | Ivan Dimitrijevic |
| collection | DOAJ |
| description | A nonlocal gravity model (2) was introduced and considered recently, and two exact cosmological solutions in flat space were presented. The first solution is related to some radiation effects generated by nonlocal dynamics on dark energy background, while the second one is a nonsingular time symmetric bounce. In the present paper, we investigate other possible exact cosmological solutions and find some the new ones in nonflat space. Used nonlocal gravity dynamics can change the background topology. To solve the corresponding equations of motion, we first look for a solution of the eigenvalue problem <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>□</mo><mo>(</mo><mi>R</mi><mo>−</mo><mn>4</mn><mi mathvariant="sans-serif">Λ</mi><mo>)</mo><mo>=</mo><mi>q</mi><mspace width="4pt"></mspace><mo>(</mo><mi>R</mi><mo>−</mo><mn>4</mn><mi mathvariant="sans-serif">Λ</mi><mo>)</mo><mo>.</mo></mrow></semantics></math></inline-formula> We also discuss possible extension of this model with a nonlocal operator, symmetric under <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>□</mo><mo>⟷</mo><msup><mo>□</mo><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula>, and its connection with another interesting nonlocal gravity model. |
| first_indexed | 2024-03-10T00:28:01Z |
| format | Article |
| id | doaj.art-c850030f5ba546ce94c1ea3937596582 |
| institution | Directory Open Access Journal |
| issn | 2073-8994 |
| language | English |
| last_indexed | 2024-03-10T00:28:01Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Symmetry |
| spelling | doaj.art-c850030f5ba546ce94c1ea39375965822023-11-23T15:31:53ZengMDPI AGSymmetry2073-89942021-12-01141310.3390/sym14010003New Cosmological Solutions of a Nonlocal Gravity ModelIvan Dimitrijevic0Branko Dragovich1Zoran Rakic2Jelena Stankovic3Faculty of Mathematics, University of Belgrade, Studentski Trg 16, 11158 Belgrade, SerbiaInstitute of Physics, University of Belgrade, 11080 Belgrade, SerbiaFaculty of Mathematics, University of Belgrade, Studentski Trg 16, 11158 Belgrade, SerbiaTeacher Education Faculty, University of Belgrade, Kraljice Natalije 43, 11000 Belgrade, SerbiaA nonlocal gravity model (2) was introduced and considered recently, and two exact cosmological solutions in flat space were presented. The first solution is related to some radiation effects generated by nonlocal dynamics on dark energy background, while the second one is a nonsingular time symmetric bounce. In the present paper, we investigate other possible exact cosmological solutions and find some the new ones in nonflat space. Used nonlocal gravity dynamics can change the background topology. To solve the corresponding equations of motion, we first look for a solution of the eigenvalue problem <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>□</mo><mo>(</mo><mi>R</mi><mo>−</mo><mn>4</mn><mi mathvariant="sans-serif">Λ</mi><mo>)</mo><mo>=</mo><mi>q</mi><mspace width="4pt"></mspace><mo>(</mo><mi>R</mi><mo>−</mo><mn>4</mn><mi mathvariant="sans-serif">Λ</mi><mo>)</mo><mo>.</mo></mrow></semantics></math></inline-formula> We also discuss possible extension of this model with a nonlocal operator, symmetric under <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>□</mo><mo>⟷</mo><msup><mo>□</mo><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula>, and its connection with another interesting nonlocal gravity model.https://www.mdpi.com/2073-8994/14/1/3nonlocal gravitycosmological solutionsnonsingular bouncecosmological constantcosmic radiationdark energy |
| spellingShingle | Ivan Dimitrijevic Branko Dragovich Zoran Rakic Jelena Stankovic New Cosmological Solutions of a Nonlocal Gravity Model Symmetry nonlocal gravity cosmological solutions nonsingular bounce cosmological constant cosmic radiation dark energy |
| title | New Cosmological Solutions of a Nonlocal Gravity Model |
| title_full | New Cosmological Solutions of a Nonlocal Gravity Model |
| title_fullStr | New Cosmological Solutions of a Nonlocal Gravity Model |
| title_full_unstemmed | New Cosmological Solutions of a Nonlocal Gravity Model |
| title_short | New Cosmological Solutions of a Nonlocal Gravity Model |
| title_sort | new cosmological solutions of a nonlocal gravity model |
| topic | nonlocal gravity cosmological solutions nonsingular bounce cosmological constant cosmic radiation dark energy |
| url | https://www.mdpi.com/2073-8994/14/1/3 |
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