On the Signature of Short Distance Scale in the Cosmic Microwave Background

Abstract

We discuss the signature of the scale of short distance physics in the Cosmic Microwave Background. In addition to effects which depend on the ratio of Hubble scale H during inflation to the energy scale M of the short distance physics, there can be effects which depend on ${\dot{\varphi }}^2/M^4$ where $\varphi$ is the {\it classical background} of the inflaton field. Therefore, the imprints of short distance physics on the spectrum of Cosmic Microwave Background anisotropies generically involve a {\it double expansion}. We present some examples of a single scalar field with higher order kinetic terms coupled to Einstein gravity, and illustrate that the effects of short distance physics on the Cosmic Microwave Background can be substantial even for H << M, and generically involve corrections that are not simply powers of H/M. The size of such effects can depend on the short distance scale non-analytically even though the action is local.

References in corpus (10)

• k-Inflation
• Perturbations in k-inflation
• The Trans-Planckian Problem of Inflationary Cosmology
• The Robustness of Inflation to Changes in Super-Planck-Scale Physics
• Inflation as a Probe of Short Distance Physics
• Inflation with a Planck-scale frequency cutoff
• Perturbation spectrum in inflation with cutoff
• Trans-Planckian dispersion and scale-invariance of inflationary perturbations
• Remarks on Inflation and Noncommutative Geometry
• Some Aspects of Brane Inflation

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