Media type: E-Article Title: Are cosmological neutrinos free-streaming? Contributor: Basbøll, Anders; Bjaelde, Ole Eggers; Hannestad, Steen; Raffelt, Georg G. Published: American Physical Society (APS), 2009 Published in: Physical Review D, 79 (2009) 4 Language: English DOI: 10.1103/physrevd.79.043512 ISSN: 1550-7998; 1550-2368 Origination: Footnote: