Acoustic Signatures
in the Cosmic Microwave Background

W.Hu, M.White

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Abstract

We study the uniqueness and robustness of acoustic signatures in the cosmic microwave background by allowing for the possibility that they are generated by some as yet unknown source of gravitational perturbations. The acoustic pattern of peak locations and relative heights predicted by the standard inflationary cold dark matter model is essentially unique and its confirmation would have deep implications for the causal structure of the early universe. A generic pattern for isocurvature initial conditions arises due to backreaction effects but is not robust to exotic source behavior inside the horizon. If present, the acoustic pattern contains unambiguous information on the curvature of the universe even in the general case. By classifying the behavior of the unknown source, we determine the minimal observations necessary for robust constraints on the curvature. The diffusion damping scale provides an entirely model independent cornerstone upon which to build such a measurement. The peak spacing, if regular, supplies a precision test.

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Files

Full Postscript File (published version)

PDF File (hyperlinked preprint)

Downloadable Figures with Captions | 1-3 | 4-6 | 7-9 | 10-12 | 13-14 |

From the Chuang-tzu

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Publication Info

astro-ph/9602019

IASSNS-AST-96/6

SLAC citations

Astrophys. J. 471 30 (1996)

whu@ias.edu