“…arise in many important problems in mathematics, mathematical physics and biology. Such equations have been extensively studied in the context of Moser-Trudinger inequalities, Chern-Simons self-dual vortices, Toda systems, conformal geometry, statistical mechanics of two-dimensional turbulence, self-gravitating cosmic strings, theory of elliptic functions and hyperelliptic curves and free boundary models of cell motility, see [BFR,BL,BL2,BLT,BCLT,BT,BT2,Be,CLS,CaY,CLMP,CLMP2,CK,CFL,CY,CY2,CY3,DJLW,GL,L,L2,LM,LM2,LW,LW2,LWY,Y] and the references cited therein. The sphere covering inequality was recently introduced in [GM], and has been applied to solve various problems about symmetry and uniqueness of solutions of elliptic equations with exponential nonlinearity in dimension n = 2.…”