A cosmological model of the early universe based on ECG with variable $\Lambda$-term in Lyra geometry

TL;DR

This paper explores cosmological models in Lyra geometry where interacting extended Chaplygin gas and quintessence scalar fields, with a variable cosmological term, can describe early universe behavior and late-time accelerated expansion.

Contribution

It introduces new interacting models involving extended Chaplygin gas and quintessence fields with a variable $\\Lambda$, analyzed numerically and graphically for the first time.

Findings

Models can describe early universe as dark matter dominated

Models exhibit late-time accelerated expansion

Numerical results support viability of the proposed models

Abstract

In this paper, we study interacting extended Chaplygin gas as dark matter and quintessence scalar field as dark energy with an effective $\Lambda$-term in Lyra manifold. As we know Chaplygin gas behaves as dark matter at the early universe while cosmological constant at the late time. Modified field equations are given and motivation of the phenomenological models discussed in details. Four different models based on the interaction term are investigated in this work. Then, we consider other models where Extended Chaplygin gas and quintessence field play role of dark matter and dark energy respectively with two different forms of interaction between the extended Chaplygin gas and quintessence scalar field for both constant and varying $\Lambda$. Concerning to the mathematical hardness of the problems we discuss results numerically and graphically. Obtained results give us hope that proposed models can work as good models for the early universe with later stage of evolution containing accelerated expansion.