Real-analytic manifolds as algebraifolds
Establish whether, for any real-analytic manifold M, the R-algebra C^\omega(M) of real-analytic functions is an R-algebraifold; equivalently, show that the C^\omega(M)-module of R-derivations Der_R(C^\omega(M)) is finitely generated projective.
References
It therefore seems plausible that C\omega(M) is an R-algebraifold as well, but we have not yet been able to prove this.
— Differential geometry and general relativity with algebraifolds
(2403.06548 - Fritz, 11 Mar 2024) in Section “Examples of algebraifolds and standard form”