Generalized Semi-Holographic Universe

TL;DR

This paper extends the semi-holographic universe model to include a particle number variable dark component with chemical potential, eliminating the need for a cosmological constant and providing a dynamic, observationally consistent cosmological evolution.

Contribution

It introduces a generalized thermodynamic framework for semi-holographic dark energy, allowing for a non-zero chemical potential and a dynamical universe without a cosmological constant.

Findings

No cosmological constant needed for universe evolution.

Transient phantom phase observed, avoiding big-rip.

Model aligns with current observational data.

Abstract

We study the semi-holographic idea in context of decaying dark components. The energy flow between dark energy and the compensating dark matter is thermodynamically generalized to involve a particle number variable dark component with non-zero chemical potential. It's found that, unlike the original semi-holographic model, no cosmological constant is needed for a dynamical evolution of the universe. A transient phantom phase appears while a non-trivial dark energy-dark matter scaling solution keeps at late time, which evades the big-rip and helps to resolve the coincidence problem. For reasonable parameters, the deceleration parameter is well consistent with current observations. The original semi-holographic model is extended and it also suggests that the concordance model may be reconstructed from the semi-holographic idea.