Isometries between C$^*$-algebras with finite corank

Michiya Mori

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arXiv · 2607.13367

Isometries between C$^*$-algebras with finite corank

Michiya Mori

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Abstract

We give a characterization of linear isometries with finite corank between two arbitrary unital C$^*$-algebras in terms of Jordan $^*$-homomorphisms and ``finite-dimensional remainders''. Also, the corresponding results are given for linear isometries and linear order embeddings between self-adjoint parts of C$^*$-algebras. In the finite-dimensional case, we give new examples of linear isometries between matrix algebras.

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Michiya Mori. 2026-07-15. Isometries between C$^*$-algebras with finite corank. https://arxiv.org/abs/2607.13367

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