Let (M, g) be a smooth, compact Riemannian n-manifold, and h be a Hölder continuous function on M . We prove the existence of multiple changing sign solutions for equations like ∆gu + hu = |u| ∗−2 u, where ∆g is the Laplace–Beltrami operator and the exponent 2∗ = 2n/ (n− 2) is critical from the Sobolev viewpoint.

We construct blowing-up sign-changing solutions to some nonlinear critical equations by glueing a standard bubble to a degenerate function. We develop a new method based on analyticity to perform the glueing when the critical manifold of solutions is degenerate and no Bianchi–Egnell type condition holds.

This paper studies a small neural network with three neurons. First, the activation function takes the sign function. Although the network is a simple hybrid systemwith all subsystems being exponentially stable, we find that it can exhibit very complex dynamics such as limit cycles and chaos. Since the sign function is a limit case of sigmoidal functions, we find that chaos robustly exists with...

IT outsourcing has three broad forms: (i) Single-Sourcing, where the client outsources to one primary vendor, (ii) Single-Sourcing with subcontracting , where the primary vendor involves other/secondary vendors in the project, and (iii) Multi-Sourcing, where the client outsources to multiple primary vendors. Using a dataset of large IT outsourcing contracts from the SCD database with 22,031 lar...

In this article we apply the minmax principle we developed in [6] to obtain sign-changing solutions for superlinear and asymptotically linear Dirichlet problems. We prove that, when isolated, the local degree of any solution given by this minmax principle is +1. By combining the results of [6] with the degree-theoretic results of Castro and Cossio in [5], in the case where the nonlinearity is a...

We prove that the non-radial sign-changing solutions to the nonlinear Schrödinger equation ∆u− u + |u|p−1u = 0 in R , u ∈ H(R ) constructed by Musso, Pacard, and Wei [19] are non-degenerate. This provides the first example of a non-degenerate sign-changing solution to the above nonlinear Schrödinger equation with finite energy.

By using the Guo-Krasnoselskii fixed point theorem, we investigate the following thirdorder three-point boundary value problem

In this paper, we deal with the existence and nonexistence of nonnegative nontrivial weak solutions for a class of degenerate quasilinear elliptic problems with weights and nonlinearity involving the critical Hardy-Sobolev exponent and a sign-changing function. Some existence results are obtained by splitting the Nerahi manifold and by exploring some properties of the best Hardy-Sobolev constan...