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arXiv · 1501.07699

Conformal Frame Dependence of Inflation

Guillem Domènech·Misao Sasaki
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Abstract

Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the matter point of view of the universe may vary from frame to frame. Thus, there is a clear distinction between gravitational sector (curvature and scalar field) and matter sector. In this paper, focusing on a simple power-law inflation model in the Einstein frame, two examples are considered; a super-inflationary and a bouncing universe Jordan frames. Then we consider a spectator curvaton minimally coupled to a Jordan frame, and compute its contribution to the curvature perturbation power spectrum. In these specific examples, we find a blue tilt at short scales for the super-inflationary case, and a blue tilt at large scales for the bouncing case.

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Guillem Domènech, Misao Sasaki. 2015-10-15. Conformal Frame Dependence of Inflation. https://doi.org/10.1088/1475-7516%2F2015%2F04%2F022

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