Holographic dark energy from a new two-parameter entropic functional

We formulate an extended holographic dark energy scenario based on a recently proposed two-parameter generalized entropic functional. Unlike constructions that phenomenologically impose modified entropy-area relations at the horizon level, the present framework is rooted in a microscopic entropy functional and the corresponding microstate counting. For bounded systems, the entropy acquires a generalized holographic scaling with two independent area contributions, recovering the Bekenstein-Hawking entropy in the appropriate limits. Implementing this entropy within the holographic principle, we derive a generalized dark energy density containing two distinct holographic sectors, naturally embedding standard holographic dark energy and $Λ$CDM as limiting cases. We analyze the cosmological evolution for both Hubble and future event horizon cutoffs and show that the model successfully reproduces the matter-to-dark-energy transition. The two entropic exponents enrich the dynamics, allowing for quintessence-like behavior or phantom regimes, while remaining compatible with the standard thermal history of the Universe.

💡 Research Summary

This paper proposes an extended holographic dark energy (HDE) framework built upon a recently introduced two‑parameter generalized entropy functional. Traditional HDE models rely on the Bekenstein‑Hawking entropy–area relation (S ∝ A) and an infrared (IR) cutoff length L, leading to a dark‑energy density ρ_DE ∝ L⁻². In contrast, the authors start from a microscopic entropy expression \