Critical comments on the paper "Crossing $\omega=-1$ by a single scalar field on a Dvali-Gabadadze-Porrati brane" by H Zhang and Z-H Zhu [Phys.Rev.D75,023510(2007)]

TL;DR

This paper critically examines a previous claim about the non-existence of scaling solutions in a dust-filled universe within the Dvali-Gabadadze-Porrati braneworld model, providing counterarguments and corrections.

Contribution

It refutes and corrects the earlier claim that no scaling solutions exist in the DGP braneworld with dust, clarifying the theoretical understanding.

Findings

Previous claim about non-existence of scaling solutions is incorrect

Scaling solutions can exist in the DGP braneworld with dust

Provides corrected analysis of scalar field dynamics in DGP scenario

Abstract

It is demonstrated that the claim in the paper "Crossing $\omega=-1$ by a single scalar field on a Dvali-Gabadadze-Porrati brane" by H Zhang and Z-H Zhu [Phys.Rev.D75,023510(2007)], about a prove that there do not exist scaling solutions in a universe with dust in a Dvali-Gabadadze-Porrati (DGP) braneworld scenario, is incorrect.