Cooray, Asantha and Li, Chao and Melchiorri, Alessandro (2008) Trispectrum of 21-cm background anisotropies as a probe of primordial non-Gaussianity. Physical Review D, 77 (10). Art. No. 103506. ISSN 0556-2821. http://resolver.caltech.edu/CaltechAUTHORS:COOprd08a
- Published Version
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:COOprd08a
The 21-cm anisotropies from the neutral hydrogen distribution prior to the era of reionization are a sensitive probe of primordial non-Gaussianity. Unlike the case with cosmic microwave background, 21-cm anisotropies provide multi-redshift information with frequency selection and are not damped at arcminute angular scales. We discuss the angular trispectrum of the 21-cm background anisotropies and discuss how the trispectrum signal generated by the primordial non-Gaussianity can be measured with the three-to-one correlator and the corresponding angular power spectrum. We also discuss the separation of primordial non-Gaussian information in the trispectrum with that generated by the subsequent nonlinear gravitational evolution of the density field. While with the angular bispectrum of 21-cm anisotropies one can limit the second-order corrections to the primordial fluctuations below fNL~1, using the trispectrum information we suggest that the third-order coupling term, f2 or gNL, can be constrained to be around 10 with future 21-cm observations over the redshift interval of 50 to 100.
|Additional Information:||©2008 The American Physical Society. (Received 22 January 2008; published 8 May 2008) This work was supported in part by NSF CAREER AST-0645427 at UC Irvine and by the Moore Foundation at Caltech. We thank David Lyth for motivating us to calculate the 21 cm trispectrum.|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Archive Administrator|
|Deposited On:||09 May 2008|
|Last Modified:||07 Dec 2016 21:46|
Repository Staff Only: item control page