AAS 201st Meeting, January, 2003
Session 67. Cosmic Gas: Long Ago and Far Away
Oral, Tuesday, January 7, 2003, 2:00-3:30pm, 606-607

## [67.01] Neutrino Heating in an Inhomogneous Big Bang Nucleosynthesis Model

J.F. Lara (Center for Relativity, UT-Austin)

The effect on Big Bang Nucleosynthesis from the heating of neutrinos by scattering with electrons and positrons and by electron-positron annihilation is worked into a spherically symmetric baryon inhomogeneous BBN model. This IBBN model is parametrized by the baryon to photon ratio, \eta, and the size of the model, ri, at an initial temperature T = 100 GK. For a range of \ln ( \eta ) = [ -10.0, -8.5 ] and ri = [ 102, 108 ] cm the heating effect increases the mass fraction X^{4}He by a range of \Delta X^{4}He = [1, 2] \times 10-4. A contour map of \Delta X^{4}He tends to track the contour map of X^{4}He. The effect appears similiar to an upward shift in the value of the baryon to photon ratio. But the heating effect on deuterium is a decrease in abundance ratio Y(d)/Y(p) on the order of 10-3, whereas Y(d)/Y(p) would decrease an order of 10-2 due to a shift in \eta10. Sufficiently accurate deuterium observations can then be used to distinguish the heating effect from other effects.