Comment on "how the huge energy of quantum vacuum gravitates to drive the slow accelerating expansion of the Universe"

In a recent paper [Q. Wang, Z. Zhu, and W. G. Unruh, Phys. Rev. D 95, 103504 (2017)PRVDAQ2470-001010.1103/PhysRevD.95.103504] it was argued that, due to the fluctuations around its mean value, vacuum energy gravitates differently from what was previously assumed. As a consequence, the Universe would...

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Bibliographic Details
Authors: Mazzitelli, Francisco Diego, Trombetta, Leonardo Giuliano
Format: article
Status:Published version
Publication Date:2018
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/99055
Online Access:http://hdl.handle.net/11336/99055
Access Level:Open access
Keyword:Cosmological Constant
Universe
Dark energy
Quantum gravity
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Description
Summary:In a recent paper [Q. Wang, Z. Zhu, and W. G. Unruh, Phys. Rev. D 95, 103504 (2017)PRVDAQ2470-001010.1103/PhysRevD.95.103504] it was argued that, due to the fluctuations around its mean value, vacuum energy gravitates differently from what was previously assumed. As a consequence, the Universe would accelerate with a small Hubble expansion rate, solving the cosmological constant and dark energy problems. We point out here that the results depend on the type of cutoff used to evaluate the vacuum energy. In particular, they are not valid when one uses a covariant cutoff such that the zero-point energy density is positive definite.