What evidence exists of black holes colliding?

[Johan0001]

Has there been any evidence of black holes converging? What would we expect to see , if anything?

 

[zoki85]

I would think gravity waves can be expected

 

[phinds]

This topic has been covered here many times. I suggest a forum search for discussions.

 

[Chalnoth]

Has there been any evidence of black holes converging? What would we expect to see , if anything?

Gravity waves. There's hope that Advanced LIGO will be able to detect them:
https://www.advancedligo.mit.edu/summary.html