Uniqueness of ground states for quasilinear elliptic equations James SerrinMoxun Tang quasilinear elliptic equationsscalar field equation Indiana University Mathematics Journal 2000 text pdf 10.1512/iumj.2000.49.1893 10.1512/iumj.2000.49.1893 en Indiana Univ. Math. J. 49 (2000) 897 - 924 state-of-the-art mathematics http://iumj.org/access/