2012/09/30 by Ignacy Sawicki, Alexander Vikman · 4 citations
Mathematics · Physics and Astronomy · #Acceleration #Black Holes and Theoretical Physics #Classical mechanics #Computer science #Cosmology #Cosmology and Gravitation Theories #Dark energy #Energy (signal processing) #Energy condition #Galaxies: Formation, Evolution, Phenomena #Geometry #Mathematical physics #Mathematics #Negative energy #Negative mass #Null (SQL) #Physics #Point (geometry) #Quantum mechanics #State (computer science) #Theoretical physics #astro-ph.CO #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.87.067301
published as Phys. Rev. D 87, 067301 (2013) · 5 pages, 1 figure. v2 reflects version accepted for publication in PRD. Changes: additional discussion of gauge-dependence in perturbed cosmologies
openalex publication_date 2013/03/01 · arxiv created 2013/03/03 · arxiv updated 2013/03/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We point out that theories of cosmological acceleration which have equation of state, w, such that 1+w is small but positive may still secretly violate the null energy condition. This violation implies the existence of observers for whom the background has infinitely negative energy densities, despite the fact that the perturbations are free of ghosts and gradient instabilities.