HEP/Astro Seminar, Wednesday 6th January 1999

Decaying, Massive Neutrinos and the Cosmic Microwave Background

Rob Lopez (U. Chicago)

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Abstract

In this talk, I explore the anisotropies of the Cosmic Microwave
Background in the presence of massive, decaying neutrinos. The effects on
the anisotropies are very different for different neutrino masses and
lifetimes. For long lifetime, low mass neutrinos, and for short lifetime,
low mass neutrinos, the anisotropies differ only slightly from the
massless, non-decaying case. I examine the distinguishability of these
models in light of future satellite-based experiments, MAP and Planck.
Another case involves a neutrino species of mass greater than 10 eV with
lifetime between 10^{13} sec and 10^{17}. Here the anisotropies at large
angles are predicted to be comparable to those on degree scales, due to
the ISW effect. Present data exclude such a possibility and hence this
region of parameter space.

3:30pm, Smith Lab 4079