Inflation from Dynamical Projective Connections
| Autor: | Muhammad Abdullah, Calvin Bavor, Biruk Chafamo, Xiaole Jiang, Muhammad Hamza Kalim, Kory Stiffler, Catherine A. Whiting |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Physical Review |
| Popis: | We show how the recently developed string-inspired, projectively-invariant gravitational model Thomas-Whitehead gravity (TW gravity) naturally gives rise to a field acting as the inflaton. In the formulation of TW gravity, a field $\mathcal{D}_{ab}$ is introduced into the projective connection components and is related to a rank-two tensor field $\mathcal{P}_{ab}$. Through the dynamical action of TW gravity, in terms of projective curvature, the tensor field $\mathcal{P}_{ab}$ acquires dynamics. By decomposing $\mathcal{P}_{ab}$ into its trace and traceless degrees of freedom, and choosing the connection to be Levi-Civita, we demonstrate that TW gravity contains a non-minimally coupled scalar field with a specific potential. Considering only the trace degrees of freedom, we demonstrate that the scalar field acts as an inflaton in the slow roll approximation. We find a range of values for the parameters introduced by TW gravity that fit the experimental constraints of the most recent cosmological data. 39 pages, 9 figures, added background material on coadjoint orbits of Virasoro algebra that demonstrates the string-inspired nature of the model, made various minor edits and corrections |
| Databáze: | OpenAIRE |
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