Abstract

Binary systems are found everywhere in astrophysics. If a binary is completely isolated, the relative motion of the two bodies describes a Keplerian ellipse which repeats itself indefinitely. However, when a binary is perturbed, its elliptical orbital elements may change with time. In particular, a wide class of perturbations can drive large-amplitude secular oscillations in a binary’s eccentricity. As a result the binary may shrink or even merge, producing exotic phenomena like hot jupiters, blue stragglers and gravitational wave bursts. In this talk I will (a) introduce the three-body problem as the archetypal example of a perturbed binary, (b) describe a new general theory for secular evolution of binaries orbiting arbitrary axisymmetric potentials, and© discuss the application of the general theory to the problem of compact-object mergers in stellar clusters.