From MOND entropy to extended uncertainty principles: A unified framework

TL;DR

This paper develops a unified framework linking generalised entropies, extended uncertainty principles, and modified cosmological equations, introducing a novel MOND-based EUP that connects various entropy models and suggests effective cutoff mechanisms.

Contribution

It introduces a reverse procedure from MOND entropy to construct a unified extended uncertainty principle, bridging different entropy formalisms and EUP models.

Findings

Derived modified Friedmann equations from various approaches.

Established the connection between HOEUP and MOND entropy.

Proposed a novel MOND EUP that reproduces Rènyi and Kaniadakis entropy relations.

Abstract

In this study, we explore the relation between generalised entropies and the extended uncertainty principle (EUP) models. Starting from the higher-order extended uncertainty principle (HOEUP), we obtain the modified entropy-area relation. Then, we derive the modified Friedmann equations through three different approaches: the first law of thermodynamics at the apparent horizon, the entropic gravity case, and the emergence of cosmic space. Furthermore, we check the validity of the generalised second law (GSL). Notably, HOEUP modified Friedmann equations are the limiting cases of those obtained from a recently proposed novel entropy, which is derived from Modified Newtonian Dynamics (MOND) [{\it Phys. Dark Universe} {\bf 49} (2025) 101967]. Motivated by this connection, we derive a novel EUP, referred to as MOND EUP, from a reverse procedure. This novel EUP reproduces to EUP relations associated with R\'enyi and dual Kaniadakis entropies in the limiting cases. Moreover, we show that HOEUP corresponds to perturbative limit of MOND entropy. The main new result of this paper is a reverse procedure beginning from a recently proposed novel MOND entropy to construct a unified EUP. This reverse procedure is not limited with the present case. In principle, the method can be applied to other generalised entropy formalisms, suggesting that our findings may establish a unified framework that bridges the generalised entropies, cutoff mechanisms, and EUP models. In particular, the corresponding modified uncertainty principles may have effective cutoff mechanisms for the entropy forms, which do not explicitly display cutoff mechanisms. Thus, these entropies may have cutoff mechanism due to their corresponding modified uncertainty principles.