scholarly journals Subsets of nonempty joint spectrum in topological algebras

2018 ◽  
Vol 143 (4) ◽  
pp. 441-448
Author(s):  
Antoni Wawrzyńczyk
2020 ◽  
Vol 24 (1) ◽  
pp. 147-158
Author(s):  
Mart Abel

We generalize the results of Abtahi and Farhangi about the joint spectrum and A-valued spectrum of a vector-valued map from the class of unital commutative semisimple Banach algebras to the case of unital topological algebras.


Author(s):  
Antoni Wawrzyńczyk

Let𝒜be a complex topological algebra with unit 1 and𝒰a family of proper closed ideals in𝒜. For an arbitraryS⊂𝒜we define a globally defined joint spectrumσ𝒰(S)={(λs)s∈S∈ℂS  |  ∃ I  ∈𝒰(s−λs)∈I ∀s∈S}. We prove that forSgenerating𝒜the spectrumσ𝒰(S)can be identified with the set𝔐𝒰of continuous multiplicative functionalsfon𝒜such that kerf∈𝒰. The relation is given by the formulaσ𝒰(S)={(f(s))s∈S  |   f∈𝔐𝒰}. If𝒜is aQ-algebra, the setσ𝒰(S)is rationally convex.


1992 ◽  
Vol 07 (35) ◽  
pp. 3291-3302 ◽  
Author(s):  
KIYONORI YAMADA

We show that the two-dimensional gravity coupled to c=−2 matter field in Polyakov’s light-cone gauge has a twisted N=2 superconformal algebra. We also show that the BRST cohomology in the light-cone gauge actually coincides with that in the conformal gauge. Based on this observation the relations between the topological algebras are discussed.


Sign in / Sign up

Export Citation Format

Share Document