cosmic strings?

Question

if cosmic strings exist would they be composed of matter or are they a defect in space time?
also has anybody calculated their mass per given length?
and is it possible for then to have an event horizon?
and one last question... wouldn't all cosmic strings be loops? seems is they weren't they would evaporate from the tips?

Answer 1

Cosmic strings are not at all the same strings as "string theory".

They are a defect in space time.
Their mass per unit length is variable, and determines the "defect angle" they create.

Strings are not surrounded by a horizon---they're 1-dimensional defects in space.

All cosmic strings are loops, although the size of the loop may be so large that part of the loop disappears into the observer's cosmic event horizon. As you point out, the end of a cosmic string would be a nasty, untenable singularity.

There is no observational evidence for cosmic strings. Given the detailed observations of the cosmic background radiation available nowdays from WMAP, it is unlikely that there is even one large cosmic string having a significant defect angle within our event horizon. Therefore, they've gone somewhat out of fashion.

Answer 2

http://www.iafe.uba.ar/relatividad/gangui/SCS.html

Answer 3

At cosmic string scales, the words matter,
space, time, & energy don't have the same
meanings we generally give them.