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Coherent Scalar Field Oscillations and the Epoch of Deceleration

J. C. Jackson
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Abstract

The discovery of supernova SN 1997ff at z~1.7 has confirmed the expected switch from cosmological acceleration to deceleration, as predicted by the concordance Lambda/CDM model. However, its position in the SN Ia Hubble diagram suggestes that the switch is too pronounced, which here is taken to mean that a cosmological constant is not an adequate description of the state of the vacuum. An 'oscillessence' model is invoked, with a scalar field phi governed by a simple quadratic potential, which gives a better fit to the new data point. The field is undergoing coherent oscillations, and a key feature of the proposal is that we are towards the end of the second period of acceleration; a Lambda/phi mix replaces Lambda/CDM, with Omega_Lambda~0.4 and Omega_phi~0.6.

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J. C. Jackson. 2001-11-19. Coherent Scalar Field Oscillations and the Epoch of Deceleration. https://arxiv.org/abs/astro-ph/0111360

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