The Warm Inflation Story
Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from interactions amongst quantum field, and its backreaction effect...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/9/6/272 |
| _version_ | 1797592466550947840 |
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| author | Arjun Berera |
| author_facet | Arjun Berera |
| author_sort | Arjun Berera |
| collection | DOAJ |
| description | Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from interactions amongst quantum field, and its backreaction effects, can occur concurrent with inflationary expansion. When we first introduced these ideas, both were met with resistance, but today they are widely accepted as possibilities with many models and applications based on them, which is an indication of the widespread influence of warm inflation. Open quantum field theory, which has been utilized in studies of warm inflation, is by now a relevant subject in cosmology, in part due to this early work. In this review I first discuss the basic warm inflation dynamics. I then outline how to compute warm inflation dynamics from first-principles quantum field theory (QFT) and in particular how a dissipative term arises. Warm inflation models can have an inflaton mass bigger than the Hubble scale and the inflaton field excursion can remain sub-Planckian, thus overcoming the most prohibitive problems of inflation model building. I discuss the early period of my work in developing warm inflation that helped me arrive at these important features of its dynamics. Inflationary cosmology today is immersed in hypothetical models, which by now are acting as a diversion from reaching any endgame in this field. I discuss better ways to approach model selection and give necessary requirements for a well constrained and predictive inflation model. A few warm inflation models are pointed out that could be developed to this extent. I discuss how, at this stage, more progress would be made in this subject by taking a broader view on the possible early universe solutions that include not just inflation but the diverse range of options. |
| first_indexed | 2024-03-11T01:51:25Z |
| format | Article |
| id | doaj.art-d4828fba49b042d8a33955493b28e166 |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-11T01:51:25Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj.art-d4828fba49b042d8a33955493b28e1662023-11-18T12:57:04ZengMDPI AGUniverse2218-19972023-06-019627210.3390/universe9060272The Warm Inflation StoryArjun Berera0School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, UKWarm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from interactions amongst quantum field, and its backreaction effects, can occur concurrent with inflationary expansion. When we first introduced these ideas, both were met with resistance, but today they are widely accepted as possibilities with many models and applications based on them, which is an indication of the widespread influence of warm inflation. Open quantum field theory, which has been utilized in studies of warm inflation, is by now a relevant subject in cosmology, in part due to this early work. In this review I first discuss the basic warm inflation dynamics. I then outline how to compute warm inflation dynamics from first-principles quantum field theory (QFT) and in particular how a dissipative term arises. Warm inflation models can have an inflaton mass bigger than the Hubble scale and the inflaton field excursion can remain sub-Planckian, thus overcoming the most prohibitive problems of inflation model building. I discuss the early period of my work in developing warm inflation that helped me arrive at these important features of its dynamics. Inflationary cosmology today is immersed in hypothetical models, which by now are acting as a diversion from reaching any endgame in this field. I discuss better ways to approach model selection and give necessary requirements for a well constrained and predictive inflation model. A few warm inflation models are pointed out that could be developed to this extent. I discuss how, at this stage, more progress would be made in this subject by taking a broader view on the possible early universe solutions that include not just inflation but the diverse range of options.https://www.mdpi.com/2218-1997/9/6/272early universe cosmologywarm inflationquantum field theorymodel building |
| spellingShingle | Arjun Berera The Warm Inflation Story Universe early universe cosmology warm inflation quantum field theory model building |
| title | The Warm Inflation Story |
| title_full | The Warm Inflation Story |
| title_fullStr | The Warm Inflation Story |
| title_full_unstemmed | The Warm Inflation Story |
| title_short | The Warm Inflation Story |
| title_sort | warm inflation story |
| topic | early universe cosmology warm inflation quantum field theory model building |
| url | https://www.mdpi.com/2218-1997/9/6/272 |
| work_keys_str_mv | AT arjunberera thewarminflationstory AT arjunberera warminflationstory |