Detection of transplanckian effects in the cosmic microwave background

Abstract

Quantum gravity effects are expected to modify the primordial density fluctuations produced during inflation and leave their imprint on the cosmic microwave background observed today. We present a new analysis discussing whether these effects are detectable, considering both currently available data and simulated results from an optimal CMB experiment. We find that the WMAP (Wilkinson Microwave Anisotropy Probe) data show no evidence for the particular signature considered in this work but give an upper bound on the parameters of the model. However, a hypothetical experiment shows that with proper data, the trans-Planckian effects should be detectable through alternate sampling methods. This fuzzy conclusion is a result of the nature of the oscillations, since they give rise to a likelihood hypersurface riddled with local maxima. A simple Bayesian analysis shows no significant evidence for the simulated data to prefer a trans-Planckian model. Conventional Markov chain Monte Carlo (MCMC) methods are not suitable for exploring this complicated landscape, but alternative methods are required to solve the problem. This, however, requires extremely high-precision data.

arXiv comment9 pages, 22 figures

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Cited by in corpus (7)

• WMAP 7 Constraints on Oscillations in the Primordial Power Spectrum
• Observing trans-Planckian ripples in the primordial power spectrum with future large scale structure probes
• Short Distance Physics and Initial State Effects on the CMB Power Spectrum
• The Effect of $\alpha$-Vacua on the Scalar and Tensor Spectral Indices: Slow-Roll Approximation
• Quantum Fluctuations in Cosmology and How They Lead to a Multiverse
• Temperature effect on the power spectrum in inflation
• Trans-Planckian quantum corrections and inflationary vacuum fluctuations of non-minimally coupled scalar fields