Feeney, SM;
Elsner, F;
Johnson, MC;
Peiris, HV;
(2015)
Forecasting constraints from the cosmic microwave background on eternal inflation.
Physical Review D
, 92
(8)
, Article 083515. 10.1103/PhysRevD.92.083515.
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Abstract
We forecast the ability of cosmic microwave background (CMB) temperature and polarization data sets to constrain theories of eternal inflation using cosmic bubble collisions. Using the Fisher matrix formalism, we determine both the overall detectability of bubble collisions and the constraints achievable on the fundamental parameters describing the underlying theory. The CMB signatures considered are based on state-of-the-art numerical relativistic simulations of the bubble collision spacetime, evolved using the full temperature and polarization transfer functions. Comparing a theoretical cosmic-variance-limited experiment to the WMAP and Planck satellites, we find that there is no improvement to be gained from future temperature data, that adding polarization improves detectability by approximately 30%, and that cosmic-variance-limited polarization data offer only marginal improvements over Planck. The fundamental parameter constraints achievable depend on the precise values of the tensor-to-scalar ratio and energy density in (negative) spatial curvature. For a tensor-to-scalar ratio of 0.1 and spatial curvature at the level of 1 0 − 4 , using cosmic-variance-limited data it is possible to measure the width of the potential barrier separating the inflating false vacuum from the true vacuum down to M Pl / 500 , and the initial proper distance between colliding bubbles to a factor π / 2 of the false vacuum horizon size (at three sigma). We conclude that very near-future data will have the final word on bubble collisions in the CMB.
| Type: | Article |
|---|---|
| Title: | Forecasting constraints from the cosmic microwave background on eternal inflation |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1103/PhysRevD.92.083515 |
| Publisher version: | http://dx.doi.org/ 10.1103/PhysRevD.92.083515 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1510678 |
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