Protogalactic extension of the Parker bound - art. no. 025002

We extend the Parker bound on the galactic flux F of magnetic monopoles. By requiring that a small initial seed held must survive the collapse of the protogalaxy, before any regenerative dynamo effects become significant, we develop a stranger bound. The survival and continued growth of an initial g alactic seed field less than or equal to 10(-9) G demand that F less than o r equal to 5 x 10(-21) (m/10(17) GeV)cm(-2) sec(-1) sr(-1). For a given mon opole mass, this bound is four and a half orders of magnitude more stringen t than the previous "extended Parker bound," but is more speculative as it depends on assumptions about the behavior of magnetic fields during protoga lactic collapse. For monopoles which do not overclose the universe (Omega(m )<l), the maximum flux allowed is now 8 x 10(-19) cm(-2) s(-1) sr(-1), a fa ctor of 150 lower than the maximum flux allowed by the extended Parker boun d.