Constraints on standard and non-standard early universe models from CMB B-mode polarization
- Kavli Institute for Cosmology Cambridge and Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA (United Kingdom)
- Department of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA (United Kingdom)
We investigate the observational signatures of three models of the early Universe in the B-mode polarization of the Cosmic Microwave Background (CMB) radiation. In addition to the standard single field inflationary model, we also consider the constraints obtainable on the loop quantum cosmology model (from Loop Quantum Gravity) and on cosmic strings, expected to be copiously produced during the latter stages of Brane inflation. We first examine the observational features of the three models, and then use current B-mode polarization data from the BICEP and QUaD experiments to constrain their parameters. We also examine the detectability of the primordial B-mode signal predicted by these models and forecast the parameter constraints achievable with future CMB polarization experiments. We find that: (a) since B-mode polarization measurements are mostly unaffected by parameter degeneracies, they provide the cleanest probe of these early Universe models; (b) using the BICEP and QUaD data we obtain the following parameter constraints: r = 0.02{sup +0.31}{sub −0.26} (1σ for the tensor-to-scalar ratio in the single field inflationary model); m < 1.36 × 10{sup −8}M{sub pl} and k{sub *} < 2.43 × 10{sup −4} Mpc{sup −1} (1σ for the mass and scale parameters in the loop quantum cosmology model); and Gμ < 5.77 × 10{sup −7} (1σ for the cosmic string tension); (c) future CMB observations (both satellite missions and forthcoming sub-orbital experiments) will provide much more rigorous tests of these early Universe models.
- OSTI ID:
- 22275340
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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