Existence and Convergence of Least-Energy Solutions Involving the Logarithmic Schrödinger Operator
Huyuan Chen, Rui Chen, Bobo Hua
TL;DR
The paper addresses existence and convergence for nonlinear nonlocal problems involving the logarithmic Schrödinger operator and the fractional pseudo-relativistic Schrödinger operator. It develops a robust variational framework on nonlocal spaces, leveraging Pitt's inequality, Brezis–Lieb splitting, and Mountain Pass geometry to obtain first existence results for critical and subcritical logarithmic nonlinearities, as well as least-energy solutions for the Brezis–Nirenberg type problem. A key contribution is establishing the convergence of least-energy solutions of the fractional problem to a nontrivial least-energy solution of the limiting logarithmic problem, together with regularity results for sublinear nonlinearities. These results extend the scope of Brezis–Nirenberg type phenomena to a combined nonlocal and logarithmic setting, providing a rigorous bridge between fractional and logarithmic operators and offering tools for further analysis of nonlocal nonlinear equations with logarithmic terms.
Abstract
In this paper, we establish the first existence result for solutions to the critical semilinear equation involving the logarithmic Schrödinger operator with subcritical logarithmic nonlinearities. Additionally, we present the first existence result for least-energy solutions to the Brezis-Nirenberg type problem for the fractional pseudo-relativistic Schrödinger operator with subcritical and critical nonlinearities. Specifically, we demonstrate that the least-energy solutions of the fractional pseudo-relativistic Schrödinger equation converge, up to a subsequence, to a nontrivial least-energy solution of the limiting problem involving the logarithmic Schrödinger operator. Furthermore, we provide regularity result for solutions to the logarithmic Schrödinger equation with sublinear nonlinearities. Our approach relies on uniform positive bounds for elements in the Nehari manifold, least-energy solutions, the Mountain-pass structure, the Palais-Smale condition, variational methods and asymptotic expansion.
