Abstract
In this note we study the relationship between the vanishing of Ext1(λ(A), λ(A)) and the existence of a regular basis in the Köthe space λ(A). We construct an example of a nuclear Köthe space λ(A) with no regular basis and such that Ext1(λ(A), λ(A))=0. Then we show that for some classes of Köthe spaces λ(A), the vanishing of Ext1(λ(A), λ(A)) yields a regular basis for λ(A).
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References
Bessaga, C.: Some remarks on Dragilev's theorem. Studia Math.31, 307–318 (1968)
Crone, L., Dubinsky, E., Robinson, W.B.: Regular bases in products of power series spaces. J. Funct. Anal.24, 211–222 (1977)
Dragilev, M.M.: On regular bases in nuclear spaces. Math. Sb.68, 153–173 (1965) (Amer. Math. Soc. Transl.93, 61–82 (1970))
Dubinsky, E.: The structure of nuclear Fréchet spaces. Lecture Notes in Mathematics 720 (1979)
Hebbecker, J.: Auswertung der Splittingbedingungen (S *1 ) und (S *2 ) für Potenzreihenräume undL f -Räume. Diplomarbeit, Wuppertal, 1984
Kocatepe, M., Nurlu, Z.: Some special Köthe spaces. Advances in the theory of Fréchet spaces (ed: T. Terzioğlu) 269–296, NATO ASI Series, Series C 287 (1989)
Krone, J.: Zur topologischen Charakterisierung von Unter- und Quotientenräumen spezieller nuklearer Kötheräume mit der Splittingmethode. Diplomarbeit, Wuppertal, 1984
Krone, J., Vogt, D.: The splitting relation for Köthe spaces. Math. Z.180, 387–400 (1985)
Robinson, W.B.: Relationships between λ-nuclearity and pseudo-μ-nuclearity. Trans. Amer. Math. Soc.201, 291–303 (1975)
Vogt, D.: Charakterisierung der Unterräume vons. Math. Z.155, 109–117 (1977)
Vogt, D.: On the functors Ext1(E, F) for Fréchet spaces. Studia Math.85, 163–197 (1987)
Wagner, M.J.: Quotientenräume von stabilen Potenzreihenräumen endlichen Typs. manus. math.31, 97–109 (1980)
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Kocatepe, M. A note on vanishing of the functor ext1 for Köthe spaces. Manuscripta Math 71, 113–119 (1991). https://doi.org/10.1007/BF02568397
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DOI: https://doi.org/10.1007/BF02568397