Refined BPS numbers on compact Calabi-Yau 3-folds from Wilson loops

par Prof. Albrecht Klemm (University of Bonn & University of Sheffield)

vendredi 28 mars 2025, 16:30 → 18:00 Europe/Paris

Salle Pierre Grisvard (IHP - Bâtiment Borel)

We relate the counting of  refined BPS numbers  on compact elliptically fibred
Calabi-Yau 3-folds $\hat X$ to Wilson loop expectations values in the gauge theories that emerge in various rigid local limits  of the 5d supergravity theory defined by M-theory compactification
on $\hat X$. In these local limits $X_*$ the volumes of curves in certain classes go to infinity, the corresponding very massive M2-brane states can be treated as Wilson loop particles and the refined topological string partition
function on $\hat X$ becomes a sum of terms proportional to associated refined Wilson loop expectation values. The resulting ansatz for the complete refined topological partition function on $\hat X$ is written in terms  of the proportionality coefficients which depend only on the $\epsilon$ deformations and the Wilson loop expectations values which
satisfy holomorphic anomaly equations. Since the ansatz is quite restrictive
and can be further constrained by the one-form symmetries and $E$-string type limits for
large base curves, we can efficiently evaluate the refined BPS numbers on $\hat X$,  which we  do explicitly for local gauge groups up to rank three and $h_{11}(\hat X)=5$. These refined BPS numbers pass an impressive number of consistency checks imposed by the direct counting of these numbers using the moduli space of one dimensional stable sheaves on $\hat X$ and give us numerical predictions for the complex structure dependency of the refined BPS numbers.

2025_03_28_A_Klemm