8 - Near Invariance for Semigroups
Published online by Cambridge University Press: 18 September 2026
Summary
The standard notion of near invariance implies near invariance for a cyclic semigroup of operators, and here the theory is considered in two related contexts. First, in a commutative semigroup with more than one generator, and second, in a continuous semigroup, of which the right shift semigroup on the positive half-line is the most important example. In this latter case the theory is not yet complete, and thus further research is motivated.
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- Nearly Invariant Subspaces and their Applications , pp. 109 - 122Publisher: Cambridge University PressPrint publication year: 2026
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