Accelerated expansion of the universe driven by tachyonic matter

Padmanabhan, T. (2002) Accelerated expansion of the universe driven by tachyonic matter Physical Review D, 66 (2). 021301_1-021301_4. ISSN 0556-2821

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Official URL: http://prd.aps.org/abstract/PRD/v66/i2/e021301

Related URL: http://dx.doi.org/10.1103/PhysRevD.66.021301

Abstract

It is an accepted practice in cosmology to invoke a scalar field with a potential V(Φ ) when the observed evolution of the universe cannot be reconciled with theoretical prejudices. Since one function degree of freedom in the expansion factor a(t) can be traded off for the function V(Φ ), it is always possible to find a scalar field potential which will reproduce a given evolution. I provide a recipe for determining V(Φ ) from a(t) in two cases: (i) a normal scalar field with the Lagrangian L=(1/2)∂aΦ∂aΦ-V(Φ ) used in quintessence or dark energy models; (ii) a tachyonic field with the Lagrangian L=-V(Φ)[1-∂aΦ∂aΦ]½ , motivated by recent string theoretic results. In the latter case, it is possible to have accelerated expansion of the universe during the late phase in certain cases.

Item Type:Article
Source:Copyright of this article belongs to American Physical Society.
ID Code:25535
Deposited On:06 Dec 2010 13:15
Last Modified:17 May 2016 09:00

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