P. Creminelli, L. Senatore, und M. Zaldarriaga. (2006)cite arxiv:astro-ph/0606001
Comment: 26 pages. v2: added comments about the approximations used, published
JCAP version.
P. Creminelli, L. Senatore, M. Zaldarriaga, und M. Tegmark. (2006)cite arxiv:astro-ph/0610600
Comment: 10 pages, 3 figures; v2: added some comments and equations, corrected
the comments on the constraint on the speed of sound.