a situation in which an academic must choose between giving priority to his/her career or his/her significant other, especially with regard to his/her location of residence;
relocating to an institution based on proximity to one's significant other at the cost of prestige, or relocating for a prestigious position at the expense of one's relationship with his/her significant other;
a system whose solution gives the equations of geographic motion of an academic and his/her significant other, often solvable by separation into center of mass motion and displacement vector motion
-"She chose UC-Irvine over MIT?"
-"Yeah, it's a two-body problem. Her boyfriend works at UCLA."