King's College London

Research portal

Black hole formation in relativistic Oscillaton collisions

Research output: Contribution to journalArticlepeer-review

James Y. Widdicombec, Thomas Helfer, Eugene A. Lim

Original languageEnglish
Article number027
JournalJournal of Cosmology and Astroparticle Physics
Issue number1
Published10 Jan 2020

King's Authors


We investigate the physics of black hole formation from the head-on collisions of boosted equal mass Oscillatons (OS) in full numerical relativity, for both the cases where the OS have equal phases or are maximally off-phase (anti-phase). While unboosted OS collisions will form a BH as long as their initial compactness C = GM/R is above a numerically determined critical value C > 0.035, we find that imparting a small initial boost counterintuitively prevents the formation of black holes even if C > 0.035. If the boost is further increased, at very high boosts γ > 1/12C, BH formation occurs as predicted by the hoop conjecture. These two limits combine to form a "stability band" where collisions result in either the OS "passing through" (equal phase) or "bouncing back" (anti-phase), with a critical point occurring around C ≈ 0.07. We argue that the existence of this stability band can be explained by the competition between the free fall and the interaction timescales of the collision.

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454