https://doi.org/10.1140/epjc/s10052-025-14335-2
Regular Article - Theoretical Physics
Acceleration from a phase of entropic balance
School of Advanced Sciences, Vellore Institute of Technology, Tiruvalam Rd, Katpadi, 632014, Vellore, Tamil Nadu, India
a
soumya.chakrabarti@vit.ac.in
Received:
27
April
2025
Accepted:
16
May
2025
Published online:
28
May
2025
We discuss the notion of generating a cosmic inflation without any big bang singularity. It has recently been proved by Good and Linder (arXiv:2503.02380 [gr-qc]) that such an expansion of the universe can be driven by quantum fluctuations embedded in vacuum. The rate of expansion is guided by a cosmological sum rule defined through the Schwarzian derivative. We explore the thermodynamic roots of Schwarzian and connect it with the surface gravity associated with an apparent horizon. In General Relativity the cosmological sum rule can be enforced only if the early universe is a Milne vacuum. We show that this restriction can be removed by considering an entropic source term in the Einstein–Hilbert action.
© The Author(s) 2025
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3.
