Stability investigations of isotropic and anisotropic exponential inflation in the Starobinsky-Bel-Robinson gravity
| Autor: | Do, Tuan Q., Nguyen, Duy H., Pham, Tuyen M. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | In this paper, we would like to examine whether a novel Starobinsky-Bel-Robinson gravity model admits stable exponential inflationary solutions with or without spatial anisotropies. As a result, we are able to derive an exact de Sitter inflationary to this Starobinsky-Bel-Robinson model. Furthermore, we observe that an exact Bianchi type I inflationary solution does not exist in the Starobinsky-Bel-Robinson model. However, we find that a modified Starobinsky-Bel-Robinson model, in which the sign of coefficient of $R^2$ term is flipped from positive to negative, can admit the corresponding Bianchi type I inflationary solution. Unfortunately, stability analysis using the dynamical system approach indicates that both of these inflationary solutions turn out to be unstable. Interestingly, we show that a stable de Sitter inflationary solution can be obtained in the modified Starobinsky-Bel-Robinson gravity. Comment: 26 pages, 2 figures. V2 with the abstract revised to improve its clarity, some relevant references added, and some typos fixed. All main calculations and conclusions remain unchanged. Comments are welcome |
| Databáze: | arXiv |
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