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arXiv · 2508.06590

Cosmic Hysteresis in Reconstructed $f(R)$ Bounce Models: A Thermodynamic Study

Aritra Sanyal·Praveen Kumar Dhankar·Albert Munyeshyaka·Safiqul Islam·Farook Rahaman
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Abstract

We study the emergence of cosmic hysteresis in cyclic bouncing universes within the framework of analytically reconstructed $f(R)$ gravity. Using exact bouncing scale factor solutions of exponential and power-law forms, we reconstruct the corresponding $f(R)$ models and investigate the thermodynamic behavior of a minimally coupled scalar field in these geometries. The pressure evolution during expansion and contraction phases is shown to be asymmetric, leading to a non-vanishing thermodynamic work integral over each cycle, defined by $\oint p_ϕ\, dV$. We identify closed hysteresis loops in the equation-of-state space and quantify the net energy transfer per cycle. Our results reveal that such reconstructed $f(R)$ models generically support irreversible evolution, demonstrating a natural emergence of the thermodynamic arrow of time. These findings provide new insight into the dissipative features of modified gravity and the long-term dynamics of cyclic cosmological scenarios.

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Aritra Sanyal, Praveen Kumar Dhankar, Albert Munyeshyaka, Safiqul Islam, Farook Rahaman. 2025-08-14. Cosmic Hysteresis in Reconstructed $f(R)$ Bounce Models: A Thermodynamic Study. https://arxiv.org/abs/2508.06590

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