On the problem of equation of state for the $\Lambda$ - field

TL;DR

This paper examines the constraints on the equation of state for the $b5$-field, a form of dark energy, and discusses how these limitations impact the modeling of the universe's accelerated expansion, including models like Chaplygin gas.

Contribution

It analyzes the restrictions on the $b5$-field's equation of state due to its unclustering behavior and explores implications for cosmological models of acceleration.

Findings

Constraints on $b5$-field's equation of state from unclustering behavior

Impact on the viability of Chaplygin gas as an alternative model

Discussion on limitations for approximating accelerated expansion

Abstract

Recently found accelarated expansion of our Universe is due to the presence of a new kind of matter called "$\Lambda$ - field" or quintessence. The limitations on its equation of state are found from the fact of its unclustering at all scales much smaller than the cosmological horizon. It is discussed how these limitations affect on the possibility to approximate the accelarated expansion by such cosmological models as the model of Chaplygin gas.