Cosmic parallax as a probe of late time anisotropic expansion
- Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy)
- INAF/Osservatorio Astronomico di Roma, V. Frascati 33, 00040 Monteporzio Catone, Roma (Italy)
Cosmic parallax is the change of angular separation between a pair of sources at cosmological distances induced by an anisotropic expansion. An accurate astrometric experiment like Gaia could observe or put constraints on cosmic parallax. Examples of anisotropic cosmological models are Lemaitre-Tolman-Bondi void models for off-center observers (introduced to explain the observed acceleration without the need for dark energy) and Bianchi metrics. If dark energy has an anisotropic equation of state, as suggested recently, then a substantial anisotropy could arise at z < or approx. 1 and escape the stringent constraints from the cosmic microwave background. In this paper we show that such models could be constrained by the Gaia satellite or by an upgraded future mission.
- OSTI ID:
- 21322701
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 80, Issue 6; Other Information: DOI: 10.1103/PhysRevD.80.063527; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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