English

Emulating $\Lambda$CDM-like expansion on the Phantom brane

General Relativity and Quantum Cosmology 2018-07-03 v1 Cosmology and Nongalactic Astrophysics High Energy Physics - Phenomenology High Energy Physics - Theory

Abstract

In [Schmidt PRD 80 123003 (2009)], the author suggested that dynamical dark energy (DDE) propagating on the phantom brane could mimick Λ\LambdaCDM. Schmidt went on to derive a phenomenological expression for ρDE\rho_{\rm DE} which could achieve this. We demonstrate that while Schmidt's central premise is correct, the expression for ρDE\rho_{\rm DE} derived in Schmidt (2009) is flawed. We derive the correct expression for ρDE\rho_{\rm DE} which leads to Λ\LambdaCDM-like expansion on the phantom brane. We also show that DDE on the brane can be associated with a Quintessence field and derive a closed form expression for its potential V(ϕ)V(\phi). Interestingly the α\alpha-attractor based potential V(ϕ)coth2λϕV(\phi) \propto \coth^2{\lambda\phi} makes braneworld expansion resemble Λ\LambdaCDM. However the two models can easily be distinguished on the basis of density perturbations which grow at different rates on the braneworld and in Λ\LambdaCDM.

Cite

@article{arxiv.1807.00684,
  title  = {Emulating $\Lambda$CDM-like expansion on the Phantom brane},
  author = {Satadru Bag and Swagat S. Mishra and Varun Sahni},
  journal= {arXiv preprint arXiv:1807.00684},
  year   = {2018}
}

Comments

15 pages, 6 figures, published in PRD. arXiv admin note: substantial text overlap with arXiv:1709.09193

R2 v1 2026-06-23T02:48:12.889Z