Ribbons on the CBR Sky: A Powerful Test of a Baryon Symmetric Universe

Abstract

If the Universe consists of domains of matter and antimatter, annihilations at domain interfaces leave a distinctive imprint on the Cosmic Background Radiation (CBR) sky. The signature is anisotropies in the form of long, thin ribbons of width ${\theta }_W\sim 0.1^{\circ }$, separated by angle ${\theta }_L\simeq 1^{\circ }(L/100h^{-1}Mpc)$ where L is the characteristic domain size, and y-distortion parameter $y\approx 10^{-6}$. Such a pattern could potentially be detected by the high-resolution CBR anisotropy experiments planned for the next decade, and such experiments may finally settle the question of whether or not our Hubble volume is baryon symmetric.

Comments: LaTeX, 10 pages, 4 figures in epsf. Revised version corrects a couple of relevant mistakes