Infante-webb spectrum of nonlinear 3 × 3 upper triangular block operator matrices

The paper examines the Infante-Webb spectrum within the framework of nonlinear block operator matrices, focusing on the relationship between the spectra of 3 ? 3 matrices and their constituent components. The focus of the study is on the Infante-Webb spectrum of 3 ? 3 nonlinear block operator matrices. This study establishes the connection between the Infante-Webb spectrum of specific 3 ? 3 nonlinear block operator matrices and the spectrum of their individual entries.