Scattering of cosmic strings by black holes: loop formation

Florian Dubath (1) , Mairi Sakellariadou (2) , Claude Viallet (3)

1 KITP - Kavli Institute for Theoretical Physics [Santa Barbara]
2 King‘s College London
3 LPTHE - Laboratoire de Physique Théorique et Hautes Energies

We study the deformation of a long cosmic string by a nearby rotating black hole. We examine whether the deformation of a cosmic string, induced by the gravitational field of a Kerr black hole, may lead to the formation of a loop of cosmic string. The segment of the string which enters the ergosphere of a rotating black hole gets deformed and, if it is sufficiently twisted, it can self-intersect chopping off a loop of cosmic string. We find that the formation of a loop, via this mechanism, is a rare event. It will only arise in a small region of the collision phase space, which depends on the string velocity, the impact parameter and the black hole angular momentum. We conclude that more frequently, the cosmic string is simply scattered or captured by the rotating black hole.

Domaines: Physique des Hautes Energies - Théorie [hep-th]; Relativité Générale et Cosmologie Quantique [gr-qc]

Florian Dubath, Mairi Sakellariadou, Claude Viallet. Scattering of cosmic strings by black holes: loop formation. International Journal of Modern Physics D, 2007, volume 16, number 8, p. 1311-1325. ⟨hal-00101749⟩