A proof for the conjecture on superlinear problems with Ambrosetti-Rabinowitz condition
Chong Li, Shujie Li
TL;DR
The paper addresses the open problem of obtaining infinitely many distinct solutions for superlinear elliptic equations under the Ambrosetti–Rabinowitz condition without symmetry. It develops a novel invariant minimax framework built from a smooth descending flow and a characteristic mapping family, augmented by mollification of the nonlinearity to enable finite-dimensional analysis and explicit lower bounds on the generalized Morse index $M(J,u)$. The authors construct an unbounded sequence of critical points $\{u_k\}$ with $M(J,u_k)\to\infty$ and $J(u_k)\to\infty$, thereby achieving multiplicity under AR alone (without the oddness condition). The approach extends minimax theory beyond symmetry-reliant methods by combining flow-invariant mappings, smoothing, and careful PS-type limit arguments, and it applies to model nonlinearities such as $-\Delta u=|u|^{p-2}u+|u|^{q-1}$ with $2\le q<p<\frac{2N}{N-2}$ (when $N\ge3$). Overall, the work resolves a long-standing conjecture in higher dimensions and broadens the toolkit for non-symmetric, superlinear elliptic problems.
Abstract
This paper is devoted to exploring a new minimax approach by introducing a characteristic mapping family which is invariant under the smooth descending flow for initial value. The minimax approach is self-contained, and its features are markedly different from standard ones, as it identifies the existence of critical points and intrinsically presents a lower-bound estimate for the generalized Morse index at the corresponding critical point. This quantity can be effectively viewed as an alternative to the group action. As applications, under the Ambrosetti-Rabinowitz condition we offer a positive answer to the long-standing open problem on the existence of infinitely many distinct solutions for superlinear elliptic equations without symmetric hypothesis.
