https://doi.org/10.1140/epjc/s10052-024-12435-z
Regular Article - Theoretical Physics
Inflation based on the Tsallis entropy
1
Department of Physics, University of Kurdistan, P.O. Box 66177-15175, Pasdaran Street, Sanandaj, Iran
2
School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran, Iran
3
Physics and Energy Engineering Department, Amirkabir University of Technology, P.O. Box 159163-4311, Tehran, Iran
Received:
9
August
2023
Accepted:
11
January
2024
Published online:
24
January
2024
We study the inflationary scenario in the Tsallis entropy-based cosmology. The Friedmann equations in this setup can be derived by using the first law of thermodynamics. To derive the relations of the power spectra of the scalar and tensor perturbations in this setup, we reconstruct an f(R) gravity model which is thermodynamically equivalent to our model in the slow-roll approximation. In this way, we find the inflationary observables, including the scalar spectral index and the tensor-to-scalar ratio in our scenario. Then, we investigate two different potentials in our scenario, including the quadratic potential and the potential associated with the natural inflation in which the inflaton is an axion or a pseudo-Nambu–Goldstone boson. We examine their observational viability in light of the Planck 2018 CMB data. We show that although the results of these potentials are in tension with the observations in the standard inflationary setting, their consistency with the observations can be significantly improved within the setup of the Tsallis entropy-based inflation. Moreover, we place constraints on the parameters of the considered inflationary models by using the current observational data.
© The Author(s) 2024
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