Publications of the Research Institute for Mathematical Sciences
Online ISSN : 1663-4926
Print ISSN : 0034-5318
Volume 36, Issue 1
Displaying 1-5 of 5 articles from this issue
  • Hiroshi Aso
    2000 Volume 36 Issue 1 Pages 1-18
    Published: 2000
    Released on J-STAGE: January 22, 2009
    JOURNAL FREE ACCESS
    It will be shown that any topological conjugacy of Z2-subshifts is factorized into a finite number of bipartite codes, and that in particular when textile shifts which are Z2-subshifts arising from textile systems introduced by Nasu are taken each bipartite code appearing in this factorization is given by a bipartite graph code of textile shifts which is defined in terms of textile systems. The latter result extends the Williams result on strong shift equivalence of Z1-topological Markov shifts to a Z2-shift case.
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  • Fabienne Prosmans
    2000 Volume 36 Issue 1 Pages 19-83
    Published: 2000
    Released on J-STAGE: April 24, 2009
    JOURNAL FREE ACCESS
    In this paper, we study the homological algebra of the category \mathcal{J}c of locally convex topological vector spaces from the point of view of derived categories. We start by showing that \mathcal{J}c is a quasi-abelian category in which products and direct sums are exact. This allows us to derive projective and inductive limit functors and to clarify their homological properties. In particular, we obtain strictness and acyclicity criteria. Next, we establish that the category formed by the separated objects of \mathcal{J}c is quasi-abelian and has the same derived category as \mathcal{J}c. Since complete objects of \mathcal{J}c do not form a quasi-abelian category, we are lead to introduce the notion of cohomological completeness and to study the derived completion functor. Our main result in this context is an equivalence between the subcategory of D(\mathcal{J}c) formed by cohomologically complete complexes and the derived category of the category of pro-Banach spaces. We show also that, under suitable assumptions, we can reduce the computation of Ext's in \mathcal{J}c to their computation in Ban by means of derived projective limits. We conclude the paper by studying derived duality functors.
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  • Nariya Kawazumi, Youichi Shibukawa
    2000 Volume 36 Issue 1 Pages 85-109
    Published: 2000
    Released on J-STAGE: April 24, 2009
    JOURNAL FREE ACCESS
    We give all the meromorphic functions defined near the origin 0∈\mathbb{C} satisfying a functional equation investigated by Bruschi and Calogero [1], [2].
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  • Hiroshi Yamada
    2000 Volume 36 Issue 1 Pages 111-138
    Published: 2000
    Released on J-STAGE: January 22, 2009
    JOURNAL FREE ACCESS
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  • Gert K. Pedersen
    2000 Volume 36 Issue 1 Pages 139-157
    Published: 2000
    Released on J-STAGE: April 24, 2009
    JOURNAL FREE ACCESS
    We study the Banach *-algebra Cop1(I) of C1-functions f on the compact interval I such that the corresponding Hilbert space operator function Tf(T), for T=T* and sp(T)⊂I, is Fréchet differentiable. If f(x)=∫eitx\widehat{f}(t)dt we know that the differential is given by the formula
    dfT(S)=∫−∞01UstSU(1−s)tds\widehat{f'} (t)dt,
    where Ut=exp(itT). Functions of this type are dense in Cop1(I), and C2(I)⊂Cop1(I)⊂C1(I), so several classical results can be deduced. In particular we show that if T∈\mathfrak{D}(δ), where δ is the generator of a one-parameter group of *-automorphisms of a C*-algebra \mathfrak{A} (or just a closed *-derivation in \mathfrak{A}), then f(T)∈\mathfrak{D}(δ) for every f in Cop1(I), where sp(T)⊂I, and
    δ(f(T))=dfT(δ(T)).
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