# Accepted value for Omega of radiation energy density

1. Mar 31, 2004

### hellfire

What is the currently accepted value for Omega of radiation energy density (photons and neutrinos)? References would be helpful. Thanks.

2. Apr 1, 2004

### Nereid

Staff Emeritus
units, ugh!

This Hyperphysics page has an overview of the concepts and relationships. http://instruct1.cit.cornell.edu/courses/astro101/lec31.htm [Broken] gives some information in bite-sized bullets. Spergel et al present the WMAP team's cosmological parameter analysis and results; this has perhaps the most up-to-date, authoratitive estimate of the neutrino omega, as well as the mass omega. From the latter it should be easy to calculate an estimate of the photon omega.

Last edited by a moderator: May 1, 2017