Astrophysical Bounds on Global Strings Typeset Using Revt E X

Global topological defects produce nonzero stress-energy throughout spacetime, and as a result can have observable gravitational innuence on surrounding matter. Gravitational eeects of global strings are used to place bounds on their cosmic abundance. The minimum separation between global strings is estimated by considering the defects' contribution to the cosmolog-ical energy density. More rigorous constraints on the abundance of global strings are constructed by examining the tidal forces such defects will have on observable astrophysical systems. The small number of observed tidally disrupted systems indicates there can be very few of these objects in the observable universe.