A Null Test of the Metric Nature of the Cosmic Acceleration
arXiv:0806.3768 · doi:10.1088/1475-7516/2008/11/001
Abstract
We discuss the testable predictions of a phenomenological model in which the accelerated expansion of the universe is the result of the action of a non-gravitational force field, rather than the effect of a negative-pressure dark-energy fluid or a modification of general relativity. We show, through the equivalence principle, that in such a scenario the cosmic acceleration felt by distant standard candles like SNIa depends on the mass of the host system, being larger in galaxies than in rich clusters. As a consequence, the scatter in the observed SNIa Hubble diagram has mostly a physical origin in this scenario: in fact, the SNIa distance modulus is increasing, at fixed redshift, for SNe that are hosted in isolated galaxies with respect to the case of SNe hosted in rich galaxy clusters. Due to its strong dependence on the astrophysical environments of standard candles, we conclude that alternative non-gravitational mechanisms for the observed accelerated expansion of the universe can be interestingly contrasted against the standard metric interpretation of the cosmological acceleration by means of an environmental analysis of the cosmic structures in which SNIa are found. The possible absence of such environmental effects would definitely exclude non-gravitational mechanisms as responsible for the accelerated cosmological expansion and will therefore reinforce a metric interpretation.
arXiv commentRevised to match the version accepted for publication in JCAP
References in corpus (18)
- Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
- Measurements of Omega and Lambda from 42 High-Redshift Supernovae
- Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
- The Cosmological Constant and Dark Energy
- A Flat Universe from High-Resolution Maps of the Cosmic Microwave Background Radiation
- The Supernova Legacy Survey: Measurement of Omega_M, Omega_Lambda and w from the First Year Data Set
- A direct empirical proof of the existence of dark matter
- New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
- Relativistic gravitation theory for the MOND paradigm
- Cosmological Constraints from the SDSS Luminous Red Galaxies
- A test of the nature of cosmic acceleration using galaxy redshift distortions
- A Local Hubble Bubble from SNe Ia?
- A Test of the Copernican Principle
- An alternative to the cosmological 'concordance model'
- Do Type Ia Supernovae prove Lambda > 0 ?
- Is the evidence for dark energy secure?
- The VIMOS VLT Deep Survey: Testing the gravitational instability paradigm at z ~ 1
- The tension of cosmological magnetic fields as a contribution to dark energy