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K-theory of the algebra A(M) associated to Hilbert–Hadamard spaces

Determine the K-theory of the C*-algebra A(M) associated to an admissible Hilbert–Hadamard space M, in general and without additional simplifying assumptions, so as to enable cutting-and-pasting approaches without recourse to deformation arguments.

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Background

A central technical obstacle identified by the authors is the difficulty of computing the K-theory of the coefficient algebra A(M) tied to Hilbert–Hadamard spaces. This limitation motivates their development of deformation techniques and localization-algebra methods to bypass direct computation.

Clarifying the K-theory of A(M) would significantly strengthen and simplify arguments in the equivariant coarse setting and could advance understanding of Novikov-type conjectures for actions on nonpositively curved infinite-dimensional spaces.

References

Unfortunately, we are not able to compute the $K$-theory of $\mathcal{A}(M)$, for which reason the usual cutting-and-pasting argument for step~(1) fails.

Hilbert-Hadamard spaces and the equivariant coarse Novikov conjecture (2411.18538 - Guo et al., 27 Nov 2024) in Introduction (Section 1), discussion of proof strategy for Theorem 1.3