Entropic Inflation in Presence of Scalar Field
In spirit of the recently proposed four-parameter generalized entropy of apparent horizon, we investigate inflationary cosmology where the matter field inside of the horizon is dominated by a scalar field with a power law potential (i.e., the form of <inline-formula><math xmlns="http:/...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/10/1/4 |
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| author | Sergei D. Odintsov Simone D’Onofrio Tanmoy Paul |
| author_facet | Sergei D. Odintsov Simone D’Onofrio Tanmoy Paul |
| author_sort | Sergei D. Odintsov |
| collection | DOAJ |
| description | In spirit of the recently proposed four-parameter generalized entropy of apparent horizon, we investigate inflationary cosmology where the matter field inside of the horizon is dominated by a scalar field with a power law potential (i.e., the form of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>ϕ</mi><mi>n</mi></msup></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>ϕ</mi></semantics></math></inline-formula> is the scalar field under consideration). Actually without any matter inside of the horizon, the entropic cosmology leads to a de-Sitter spacetime, or equivalently, an eternal inflation with no exit. Thus in order to achieve a viable inflation, we consider a minimally coupled scalar field inside the horizon, and moreover, with the simplest quadratic potential. It is well known that the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>ϕ</mi><mn>2</mn></msup></semantics></math></inline-formula> potential in standard scalar field cosmology is ruled out from inflationary perspective as it is not consistent with the recent Planck 2018 data; (here it may be mentioned that in the realm of “apparent horizon thermodynamics”, the standard scalar field cosmology is analogous to the case where the entropy of the apparent horizon is given by the Bekenstein–Hawking entropy). However, the story becomes different if the horizon entropy is of generalized entropic form, in which case, the effective energy density coming from the horizon entropy plays a significant role during the evolution of the universe. In particular, it turns out that in the context of generalized entropic cosmology, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>ϕ</mi><mn>2</mn></msup></semantics></math></inline-formula> potential indeed leads to a viable inflation (according to the Planck data) with a graceful exit, and thus the potential can be made back in the scene. |
| first_indexed | 2024-03-08T10:33:27Z |
| format | Article |
| id | doaj.art-6ff7155d84194432a666881df41c15ee |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-08T10:33:27Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
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| series | Universe |
| spelling | doaj.art-6ff7155d84194432a666881df41c15ee2024-01-26T18:42:54ZengMDPI AGUniverse2218-19972023-12-01101410.3390/universe10010004Entropic Inflation in Presence of Scalar FieldSergei D. Odintsov0Simone D’Onofrio1Tanmoy Paul2ICREA, Passeig Luis Companys, 23, 08010 Barcelona, SpainInstitute of Space Sciences (ICE, CSIC), C. Can Magrans s/n, 08193 Barcelona, SpainDepartment of Physics, Visva-Bharati University, Santiniketan 731235, IndiaIn spirit of the recently proposed four-parameter generalized entropy of apparent horizon, we investigate inflationary cosmology where the matter field inside of the horizon is dominated by a scalar field with a power law potential (i.e., the form of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>ϕ</mi><mi>n</mi></msup></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>ϕ</mi></semantics></math></inline-formula> is the scalar field under consideration). Actually without any matter inside of the horizon, the entropic cosmology leads to a de-Sitter spacetime, or equivalently, an eternal inflation with no exit. Thus in order to achieve a viable inflation, we consider a minimally coupled scalar field inside the horizon, and moreover, with the simplest quadratic potential. It is well known that the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>ϕ</mi><mn>2</mn></msup></semantics></math></inline-formula> potential in standard scalar field cosmology is ruled out from inflationary perspective as it is not consistent with the recent Planck 2018 data; (here it may be mentioned that in the realm of “apparent horizon thermodynamics”, the standard scalar field cosmology is analogous to the case where the entropy of the apparent horizon is given by the Bekenstein–Hawking entropy). However, the story becomes different if the horizon entropy is of generalized entropic form, in which case, the effective energy density coming from the horizon entropy plays a significant role during the evolution of the universe. In particular, it turns out that in the context of generalized entropic cosmology, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>ϕ</mi><mn>2</mn></msup></semantics></math></inline-formula> potential indeed leads to a viable inflation (according to the Planck data) with a graceful exit, and thus the potential can be made back in the scene.https://www.mdpi.com/2218-1997/10/1/4entropic cosmologygeneralized entropyapparent horizoninflationscalar field |
| spellingShingle | Sergei D. Odintsov Simone D’Onofrio Tanmoy Paul Entropic Inflation in Presence of Scalar Field Universe entropic cosmology generalized entropy apparent horizon inflation scalar field |
| title | Entropic Inflation in Presence of Scalar Field |
| title_full | Entropic Inflation in Presence of Scalar Field |
| title_fullStr | Entropic Inflation in Presence of Scalar Field |
| title_full_unstemmed | Entropic Inflation in Presence of Scalar Field |
| title_short | Entropic Inflation in Presence of Scalar Field |
| title_sort | entropic inflation in presence of scalar field |
| topic | entropic cosmology generalized entropy apparent horizon inflation scalar field |
| url | https://www.mdpi.com/2218-1997/10/1/4 |
| work_keys_str_mv | AT sergeidodintsov entropicinflationinpresenceofscalarfield AT simonedonofrio entropicinflationinpresenceofscalarfield AT tanmoypaul entropicinflationinpresenceofscalarfield |