On operators with the same spectrum
Gh. Constantin (1975)
Matematički Vesnik
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Displaying similar documents to “The spectrum of operators on ”
On operators with the same spectrum
Ascent and descent for sets of operators
Derek Kitson (2009)
Studia Mathematica
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We extend the notion of ascent and descent for an operator acting on a vector space to sets of operators. If the ascent and descent of a set are both finite then they must be equal and give rise to a canonical decomposition of the space. Algebras of operators, unions of sets and closures of sets are treated. As an application we construct a Browder joint spectrum for commuting tuples of bounded operators which is compact-valued and has the projection property.
Diagonals of Self-adjoint Operators with Finite Spectrum
Marcin Bownik, John Jasper (2015)
Bulletin of the Polish Academy of Sciences. Mathematics
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Given a finite set X⊆ ℝ we characterize the diagonals of self-adjoint operators with spectrum X. Our result extends the Schur-Horn theorem from a finite-dimensional setting to an infinite-dimensional Hilbert space analogous to Kadison's theorem for orthogonal projections (2002) and the second author's result for operators with three-point spectrum (2013).
On the generalized Kato spectrum
Benharrat, Mohammed, Messirdi, Bekkai (2011)
Serdica Mathematical Journal
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2010 Mathematics Subject Classification: 47A10. We show that the symmetric difference between the generalized Kato spectrum and the essential spectrum defined in [7] by sec(T) = {l О C ; R(lI-T) is not closed } is at most countable and we also give some relationship between this spectrum and the SVEP theory.
Quasihyponormal operators and the continuity of the approximate point spectrum.
Djordjević, Slaviša V. (1997)
Matematichki Vesnik
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The fine spectra of some Cesàro generalized operators defined on ().
Bucur, Amelia (1996)
General Mathematics
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On the essential order spectrum
Lutz W. Weis (1986)
Extracta Mathematicae
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Commutation relations involving spectrally scattered operators
W. Młak (1990)
Annales Polonici Mathematici
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Spectra of partial integral operators with a kernel of three variables
Yusup Eshkabilov (2008)
Open Mathematics
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Let Ω= [a, b] × [c, d] and T 1, T 2 be partial integral operators in (Ω): (T 1 f)(x, y) = k 1(x, s, y)f(s, y)ds, (T 2 f)(x, y) = k 2(x, ts, y)f(t, y)dt where k 1 and k 2 are continuous functions on [a, b] × Ω and Ω × [c, d], respectively. In this paper, concepts of determinants and minors of operators E−τT 1, τ ∈ ℂ and E−τT 2, τ ∈ ℂ are introduced as continuous functions on [a, b] and [c, d], respectively. Here E is the identical operator in C(Ω). In addition, Theorems on the spectra...
Remarks on similarity and quasisimilarity of operators
J. Janas (1988)
Colloquium Mathematicae
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On joint spectra of operators on a Banach space isomorphic to its square
Andrzej Sołtysiak (1989)
Colloquium Mathematicae
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On the axiomatic theory of spectrum
V. Kordula, V. Müller (1996)
Studia Mathematica
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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).