Abstract. The spectra of the 2 × 2 upper triangular operator matrix M C = ( A C 0 B ) acting on a Hilbert space 𝐻₁ ⨁ 𝐻₂ are investigated. We obtain a necessary and sufficient condition of 𝜎 (𝑀𝐶) ...

In this note we study spectral properties of a block operator matrix à (see (1.1) below), where A and –D are m-accretive, and B, D are bounded operators. Under an additional assumption, the spectrum ...

Professor Jim Gates talks physics and whether we’re all living in the Matrix August 25, 2016 More than 8 years ago ...