How fabulous is Fab 5 cosmology?
Extended gravity origins for cosmic acceleration can solve some fine tuning issues and have useful characteristics, but generally have little to say regarding the cosmological constant problem. Fab 5 gravity can be ghost free and stable, have attractor solutions in the past and future, and possess self tuning that solves the original cosmological constant problem. Here we show however it does not possess all these qualities at the same time. We also demonstrate that the self tuning is so powerful that it not only cancels the cosmological constant but also all other energy density, and we derive the scalings of its approach to a renormalized de Sitter cosmology. While this strong cancellation is bad for the late universe, it greatly eases early universe inflation.
- Berkeley Center for Cosmological Physics and Berkeley Lab, University of California, Berkeley, CA, 94720 (United States)
- Publication Date:
- OSTI Identifier:
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2013; Journal Issue: 12; Other Information: Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; COSMOLOGICAL CONSTANT; COSMOLOGY; DE SITTER SPACE; ENERGY DENSITY; GRAVITATION; ORIGIN; RENORMALIZATION; UNIVERSE COSMOLOGICAL INFLATION