Multi-bump solutions for sublinear elliptic equations with nonsymmetric coefficients

TL;DR

This paper proves the existence of infinitely many nonnegative bump solutions to a class of sublinear elliptic equations with nonsymmetric potentials, using a novel truncated functional approach and sharp support estimates.

Contribution

It introduces a new method based on truncated functional spaces to construct multiple bump solutions without symmetry assumptions.

Findings

Existence of infinitely many bump solutions under small perturbations of the potential.

Development of uniform support estimates for multiple bumps.

Application of a truncated functional space to control bump interactions.

Abstract

We investigate the existence of nonnegative bump solutions to the sublinear elliptic equation \[ \begin{cases} -\Delta v - K(x)v + |v|^{q-2}v = 0 & \text{in } \mathbb{R}^N, \\ v(x) \to 0 & \text{as } |x| \to \infty, \end{cases} \] where $q \in (1,2)$, $ N \geq 2$, and the potential $K \in L^p_{\mathrm{loc}}(\mathbb{R}^N)$ with $p > N/2$ is a function without any symmetry assumptions. Under the condition that $\|K - 1\|_{L^p_{\mathrm{loc}}}$ is sufficiently small, we construct infinitely many solutions with arbitrarily many bumps. The construction is challenged by the sensitive interaction between bumps, whose limiting profiles have compact support. The key to ensuring their effective separation lies in obtaining sharp estimates of the support sets. Our method, based on a truncated functional space, provides precisely such control. We derive qualitative local stability estimates in region-wise maximum norms that govern the size of each bump's essential support, confining its core to a designated region and minimizing overlap. Crucially, these estimates are uniform in the number of bumps, which is the pivotal step in establishing the existence of solutions with infinitely many bumps.