When a large black hole captures a smaller object (say, a star) this process emits gravitational radiation ("ripples" in space-time) in a specific direction. These waves carry energy and momentum away from this binary system, and therefore the system experiences a backward "kick" or "recoil", just like what one gets upon firing a rifle! Now, a mystery associated to this recoil is that for some very special scenarios (rapidly rotating black holes and prograde orbits), this kick get completely cancelled by an "anti kick" that surprisingly happens just as the star finally gets swallowed by the large black hole. This process would result in the large black hole simply getting displaced by thousands of kilometers from its original location simply due to capturing a small star. In a recently published research article, Prof. Khanna and his colleagues present a rather simple argument that explains the origin of the "anti kick". The detailed computer simulations for this work were performed on the Air Force Research Lab's CONDOR supercomputer, which is a system built from 1,716 Sony PlayStation 3 gaming consoles.
The article has just appeared in the June edition of the top American Physical Society journal: Physical Review D. The work was done in collaboration with Prof. Khanna's colleagues at MIT and UTexas. This research was supported by the National Science Foundation.
Author: "Gaurav Khanna [Contact]"
Submitted by: Olivia Farinha
Department: College Of Engineering - Phy