English

How the cosmological constant is hidden by Planck scale curvature fluctuations

General Relativity and Quantum Cosmology 2019-11-26 v3 High Energy Physics - Theory

Abstract

It is argued in a recent letter Phys. Rev. Lett. 123, 131302(2019) that the effect of a large cosmological constant can be naturally hidden in Planck scale curvature fluctuations. We point out that there are problems with the author's arguments. The hiding of the cosmological constant proposed in the letter by choosing a suitable lapse function is just an illusion maintained by external forces. In particular, it can not be achieved if the cosmological constant is positive. Fortunately, it works for a negative cosmological constant in a different way, and, interestingly, the sign of the cosmological constant just needs to be negative to make the average spatial curvature R\langle R\rangle small.

Keywords

Cite

@article{arxiv.1911.06110,
  title  = {How the cosmological constant is hidden by Planck scale curvature fluctuations},
  author = {Qingdi Wang and William G. Unruh},
  journal= {arXiv preprint arXiv:1911.06110},
  year   = {2019}
}

Comments

5 pages. v2 corrected some nonessential misunderstandings on the letter Phys. Rev. Lett. 123, 131302(2019) presented in the beginning of Sec.II of v1. v3 has further important revisions