R2 inflation revisited and dark energy corrections
The vacuum R2 model is known to generate a quasi-de Sitter evolution for inflation, using solely the slow-roll assumptions. Using standard reconstruction techniques, we demonstrate that the f(R) gravity which actually realizes the quasi-de Sitter evolution is not simply the R2 model but a deformed R...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/261352 |
| Acceso en línea: | http://hdl.handle.net/10261/261352 |
| Access Level: | acceso abierto |
| Palabra clave: | Alternative gravity theories Cosmological parameters Dark energy Inflation |
| Sumario: | The vacuum R2 model is known to generate a quasi-de Sitter evolution for inflation, using solely the slow-roll assumptions. Using standard reconstruction techniques, we demonstrate that the f(R) gravity which actually realizes the quasi-de Sitter evolution is not simply the R2 model but a deformed R2 model which contains extra terms in addition to the R2 model. We analyze in detail the inflationary dynamics of the deformed R2 model and we demonstrate that the predictions are quite close to the ones of the pure R2 model, regardless the values of the free parameters. Basically the deformed R2 model is also a single parameter inflationary model, exactly like the ordinary R2 model. In contrast to the early-time era, where the deformed R2 model is quite similar to the R2 model, at late times, the phenomenological picture is different. The deformed R2 model describes stronger gravity compared to the ordinary R2 with an effectively smaller effective Planck mass. We propose the addition of an early dark energy term which does not affect at all the inflationary era, but takes over the control of the late-time dynamics at late times. We study in some detail the predicted dark energy era evolution, and we demonstrate that the dark energy corrected deformed R2 model can describe a viable dark energy era, compatible with the Planck constraints on cosmological parameters. Furthermore the model is distinct from the Λ cold dark matter model, but shows a qualitatively similar behavior. |
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