On invariant subspaces of a linear operator
M. I. Belishev, S. A. Simonov
Abstract
We discuss the concept of invariant subspaces for unbounded linear operators, point out some shortcomings of known definitions, and propose our own.
M. I. Belishev, S. A. Simonov
We discuss the concept of invariant subspaces for unbounded linear operators, point out some shortcomings of known definitions, and propose our own.
M. I. Belishev, S. A. Simonov
This paper contains 4 sections, 1 theorem, 7 equations.
Theorem 1
If the operator $A$ is symmetric (i.e., $A\subset A^*$), $\mathscr G$ is its invariant subspace, and its part in $\mathscr G$ is self-adjoint (i.e., $A_\mathscr G=A_\mathscr G^*$ in $\mathscr G$), then $\mathscr G$ reduces $A$.