Electronic Journal of Differential Equations, 
Vol. 2019 (2019), No. 128, pp. 1-11.

Title:  Existence, regularity and positivity of ground states for nonlocal nonlinear 
          Schrodinger equations

Author:  Yong-Chao Zhang (Northeastern Univ.,  Qinhuangdao, China)

Abstract:
 We study ground states of a nonlinear Schr\"odinger equation driven
 by the infinitesimal generator of a rotationally invariant Levy process.
 The equation includes  many special cases such as classical Schrodinger equations,
 fractional Schrodinger equations and relativistic Schrodinger equations, etc.
 It is proved that the equation possesses ground states in a suitable space of
 functions, then the regularity of solutions to the equation is examined,
 in particular, any solution is H\"older continuous, and, if the process involves
 diffusion terms, any solution is twice differentiable further.
 Finally, we show that any ground state is either positive or negative.
 
Submitted January 9, 2019. Published November 26, 2019.
Math Subject Classifications:  35Q55, 35J60, 35A15.
Key Words: Nonlocal Schrodinger equation; ground state;
                     infinitesimal generator; rotationally invariant Levy process.