A Perron FrobeniusTheory for Representations of Locally Compact Abelian Groups.
The spectral mapping theorem for one-parameter groups of positive operators on C0(X).
The spectral mapping theorem for integrated semigroups.
On the modulus of one-parameter semigroups.
Commutativity of compact selfadjoint operators
The relationship between the joint spectrum γ(A) of an n-tuple of selfadjoint operators and the support of the corresponding Weyl calculus T(A) : f ↦ f(A) is discussed. It is shown that one always has γ(A) ⊂ supp (T(A)). Moreover, when the operators are compact, equality occurs if and only if the operators mutually commute. In the non-commuting case the equality fails badly: While γ(A) is countable, supp(T(A)) has to be an uncountable set. An example is given showing that, for non-compact operators,...
On the stability of strongly continuous semigroups of positive operators on
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