Furi-Martelli-Vignoli spectrum and Feng spectrum of nonlinear block operator matrices

We investigate the Furi-Martelli-Vignoli spectrum and the Feng spectrum of continuous nonlinear block operator matrices, and mainly describe the relationship between the Furi-Martelli-Vignoli spectrum (compared to the Feng spectrum) of the whole operator matrix and that of its entries. In addition, the connection between the Furi-Martelli-Vignoli spectrum of the whole operator matrix and that of its Schur complement is presented by means of Schur decomposition.