Reconstructed <i>f</i>(<i>R</i>) Gravity and Its Cosmological Consequences in theChameleon Scalar Field with a Scale Factor Describing the Pre-Bounce Ekpyrotic Contraction
The present study reports a reconstruction scheme for <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula>...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-09-01
|
| Series: | Symmetry |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-8994/12/9/1559 |
| _version_ | 1797553021821911040 |
|---|---|
| author | Soumyodipta Karmakar Kairat Myrzakulov Surajit Chattopadhyay Ratbay Myrzakulov |
| author_facet | Soumyodipta Karmakar Kairat Myrzakulov Surajit Chattopadhyay Ratbay Myrzakulov |
| author_sort | Soumyodipta Karmakar |
| collection | DOAJ |
| description | The present study reports a reconstruction scheme for <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> gravity with the scale factor <inline-formula><math display="inline"><semantics><mrow><mi>a</mi><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow><mo>∝</mo><msup><mrow><mo>(</mo><msub><mi>t</mi><mo>*</mo></msub><mo>−</mo><mi>t</mi><mo>)</mo></mrow><mfrac><mn>2</mn><msup><mi>c</mi><mn>2</mn></msup></mfrac></msup></mrow></semantics></math></inline-formula> describing the pre-bounce ekpyrotic contraction, where <inline-formula><math display="inline"><semantics><msub><mi>t</mi><mo>*</mo></msub></semantics></math></inline-formula> is the big crunch time. The reconstructed <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> is used to derive expressions for density and pressure contributions, and the equation of state parameter resulting from this reconstruction is found to behave like “quintom”. It has also been observed that the reconstructed <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> has satisfied a sufficient condition for a realistic model. In the subsequent phase, the reconstructed <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> is applied to the model of the chameleon scalar field, and the scalar field <inline-formula><math display="inline"><semantics><mi>ϕ</mi></semantics></math></inline-formula> and the potential <inline-formula><math display="inline"><semantics><mrow><mi>V</mi><mo>(</mo><mi>ϕ</mi><mo>)</mo></mrow></semantics></math></inline-formula> are tested for quasi-exponential expansion. It has been observed that although the reconstructed <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> satisfies one of the sufficient conditions for realistic model, the quasi-exponential expansion is not available due to this reconstruction. Finally, the consequences of pre-bounce ekpyrotic inflation in <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> gravity are compared to the background solution for <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> matter bounce. |
| first_indexed | 2024-03-10T16:10:25Z |
| format | Article |
| id | doaj.art-37f8b996bb86413e920051072dda6849 |
| institution | Directory Open Access Journal |
| issn | 2073-8994 |
| language | English |
| last_indexed | 2024-03-10T16:10:25Z |
| publishDate | 2020-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Symmetry |
| spelling | doaj.art-37f8b996bb86413e920051072dda68492023-11-20T14:31:51ZengMDPI AGSymmetry2073-89942020-09-01129155910.3390/sym12091559Reconstructed <i>f</i>(<i>R</i>) Gravity and Its Cosmological Consequences in theChameleon Scalar Field with a Scale Factor Describing the Pre-Bounce Ekpyrotic ContractionSoumyodipta Karmakar0Kairat Myrzakulov1Surajit Chattopadhyay2Ratbay Myrzakulov3Department of Mathematics, Amity University Kolkata, Major Arterial Road, Action Area II, Rajarhat, New Town, Kolkata 700135, IndiaEurasian International Center for Theoretical Physics, Eurasian National University, Nur-Sultan 010008, KazakhstanDepartment of Mathematics, Amity University Kolkata, Major Arterial Road, Action Area II, Rajarhat, New Town, Kolkata 700135, IndiaEurasian International Center for Theoretical Physics, Eurasian National University, Nur-Sultan 010008, KazakhstanThe present study reports a reconstruction scheme for <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> gravity with the scale factor <inline-formula><math display="inline"><semantics><mrow><mi>a</mi><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow><mo>∝</mo><msup><mrow><mo>(</mo><msub><mi>t</mi><mo>*</mo></msub><mo>−</mo><mi>t</mi><mo>)</mo></mrow><mfrac><mn>2</mn><msup><mi>c</mi><mn>2</mn></msup></mfrac></msup></mrow></semantics></math></inline-formula> describing the pre-bounce ekpyrotic contraction, where <inline-formula><math display="inline"><semantics><msub><mi>t</mi><mo>*</mo></msub></semantics></math></inline-formula> is the big crunch time. The reconstructed <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> is used to derive expressions for density and pressure contributions, and the equation of state parameter resulting from this reconstruction is found to behave like “quintom”. It has also been observed that the reconstructed <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> has satisfied a sufficient condition for a realistic model. In the subsequent phase, the reconstructed <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> is applied to the model of the chameleon scalar field, and the scalar field <inline-formula><math display="inline"><semantics><mi>ϕ</mi></semantics></math></inline-formula> and the potential <inline-formula><math display="inline"><semantics><mrow><mi>V</mi><mo>(</mo><mi>ϕ</mi><mo>)</mo></mrow></semantics></math></inline-formula> are tested for quasi-exponential expansion. It has been observed that although the reconstructed <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> satisfies one of the sufficient conditions for realistic model, the quasi-exponential expansion is not available due to this reconstruction. Finally, the consequences of pre-bounce ekpyrotic inflation in <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> gravity are compared to the background solution for <inline-formula><math display="inline"><semantics><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></semantics></math></inline-formula> matter bounce.https://www.mdpi.com/2073-8994/12/9/1559pre-bounce ekpyrotic contraction<i>f</i>(<i>R</i>) gravityreconstruction |
| spellingShingle | Soumyodipta Karmakar Kairat Myrzakulov Surajit Chattopadhyay Ratbay Myrzakulov Reconstructed <i>f</i>(<i>R</i>) Gravity and Its Cosmological Consequences in theChameleon Scalar Field with a Scale Factor Describing the Pre-Bounce Ekpyrotic Contraction Symmetry pre-bounce ekpyrotic contraction <i>f</i>(<i>R</i>) gravity reconstruction |
| title | Reconstructed <i>f</i>(<i>R</i>) Gravity and Its Cosmological Consequences in theChameleon Scalar Field with a Scale Factor Describing the Pre-Bounce Ekpyrotic Contraction |
| title_full | Reconstructed <i>f</i>(<i>R</i>) Gravity and Its Cosmological Consequences in theChameleon Scalar Field with a Scale Factor Describing the Pre-Bounce Ekpyrotic Contraction |
| title_fullStr | Reconstructed <i>f</i>(<i>R</i>) Gravity and Its Cosmological Consequences in theChameleon Scalar Field with a Scale Factor Describing the Pre-Bounce Ekpyrotic Contraction |
| title_full_unstemmed | Reconstructed <i>f</i>(<i>R</i>) Gravity and Its Cosmological Consequences in theChameleon Scalar Field with a Scale Factor Describing the Pre-Bounce Ekpyrotic Contraction |
| title_short | Reconstructed <i>f</i>(<i>R</i>) Gravity and Its Cosmological Consequences in theChameleon Scalar Field with a Scale Factor Describing the Pre-Bounce Ekpyrotic Contraction |
| title_sort | reconstructed i f i i r i gravity and its cosmological consequences in thechameleon scalar field with a scale factor describing the pre bounce ekpyrotic contraction |
| topic | pre-bounce ekpyrotic contraction <i>f</i>(<i>R</i>) gravity reconstruction |
| url | https://www.mdpi.com/2073-8994/12/9/1559 |
| work_keys_str_mv | AT soumyodiptakarmakar reconstructedifiirigravityanditscosmologicalconsequencesinthechameleonscalarfieldwithascalefactordescribingtheprebounceekpyroticcontraction AT kairatmyrzakulov reconstructedifiirigravityanditscosmologicalconsequencesinthechameleonscalarfieldwithascalefactordescribingtheprebounceekpyroticcontraction AT surajitchattopadhyay reconstructedifiirigravityanditscosmologicalconsequencesinthechameleonscalarfieldwithascalefactordescribingtheprebounceekpyroticcontraction AT ratbaymyrzakulov reconstructedifiirigravityanditscosmologicalconsequencesinthechameleonscalarfieldwithascalefactordescribingtheprebounceekpyroticcontraction |