University of Chicago

## Talks by Abraham Harte

## Extended-body effects in general relativity: What is possible?

Abraham Harte
University of Chicago

To a first approximation, objects in general relativity move along geodesics. Looked at more closely, a body's internal structure can affect its motion. This talk will explore some of the surprising possibilities which arise when such effects are taken into account. An object can, for example, control its orbit merely by manipulating its internal structure: unstable orbits can be stabilized, bound orbits can be made unbound, and more, all without a rocket.

## Spin-induced bobbing effects in relativistic systems

Abraham Harte
University of Chicago

Recent numerical simulations of spinning binary black holes have found that the orbital plane tends to bob up and down in phase with the orbit. It will be shown that similar effects occur in nearly all relativistic systems. The reasons for this are essentially kinematic and appear unrelated to those leading to the final "kicks" observed after merger. Simple examples are provided for binary systems bound together by gravitational electromagnetic and mechanical forces.