Determine the number of connected components of the odd-dimensional Ulrich-bundle moduli stack

Determine how many connected components the moduli stack of rank-[?] Ulrich bundles on a smooth intersection of two odd-dimensional quadrics has, beyond the explicitly constructed components.

Background

For a smooth intersection X of two odd-dimensional quadrics, the paper constructs multiple connected components of the moduli stack of Ulrich bundles by relating it to moduli spaces of parabolic bundles on the root stack P1_{2g+1}. In rank two, at least (2g+1g+1)\binom{2g+1}{g+1} components are obtained. The construction does not exclude additional components, and the authors report numerical evidence suggesting that, up to degree-zero twists, the explicitly constructed components may be all the components in rank two. The general number of connected components remains unresolved.

References

Our proof does not rule out the possibility of the existence of extra components. However, based on some numerical calculations in low-rank, low-genus cases, we suspect that the only connected components of U_{2\cdot2{g-3}(X) are degree-zero twists of those constructed in the proof of Theorem~\ref{thm:mainthmodd}. In general, we do not know how many connected components of U_{r2{g-3}(X) exist.

— Ulrich bundles on intersections of two quadrics  (2609.09596 - Jung et al., 9 Sep 2026) in Section 1, subsection “Intersection of two quadrics”

We do not know if, up to degree-zero twists, there are any extra components of U_{2\cdot2{g-3}(X) or whether U_{2\cdot2{g-3}(X) is equidimensional.

— Ulrich bundles on intersections of two quadrics  (2609.09596 - Jung et al., 9 Sep 2026) in Remark \ref{rmk:dimension}, near the end of Section 1