Displaying similar documents to “Nonnegative point spectrum for differential equations with infinite delays”

Axiomatic theory of spectrum III: semiregularities

Vladimír Müller (2000)

Studia Mathematica

Similarity:

We introduce and study the notions of upper and lower semiregularities in Banach algebras. These notions generalize the previously studied notion of regularity - a class is a regularity if and only if it is both upper and lower semiregularity. Each semiregularity defines in a natural way a spectrum which satisfies a one-way spectral mapping property (the spectrum defined by a regularity satisfies the both-ways spectral mapping property).

On the axiomatic theory of spectrum

V. Kordula, V. Müller (1996)

Studia Mathematica

Similarity:

There are a number of spectra studied in the literature which do not fit into the axiomatic theory of Żelazko. This paper is an attempt to give an axiomatic theory for these spectra, which, apart from the usual types of spectra, like one-sided, approximate point or essential spectra, include also the local spectra, the Browder spectrum and various versions of the Apostol spectrum (studied under various names, e.g. regular, semiregular or essentially semiregular).