ON THE POIN ON THE POINT SPECTRUM OF OPERA TRUM OF OPERATOR MATRIX COMIMG T X COMIMG TO A A DIAGONALIZABLE MATRIX

Abstract

It isconsidered herethediagonalizable operatormatrix . The essential and point spectrum of are described via the spectrum of the more simpler operator matrices. If the elements of a matrix are linear operators in Banach or Hilbert spaces, then it is called a block-operator matrix. One of the special classes of block operator matrices are the Hamiltonians of a system with a nonconserved number of quantum particles on an integer or noninteger lattice. The inclusion for the discrete spectrum of is established.