Orientations for skein-valued curve counting
Abstract
Ekholm and Shende's skeins-on-branes formalism provides invariant counts of holomorphic curves with boundary on a Maslov zero Lagrangian within a Calabi-Yau 3-fold. This paper proves the orientation relations required for worldsheet skein relations to cancel codimension-one boundary strata. However, standard Cauchy-Riemann Fredholm orientations reveal an unexpected sign puzzle: the orientation relation at a curve with a hyperbolic boundary crossing depends on whether the crossing lies on distinct boundary components or the same component. This domain-dependent sign contradicts the uniform crossing relations of the HOMFLYPT skein algebra. We show that this discrepancy is resolved by passing to an anti-holomorphic orientation convention. We establish all required orientation comparisons in the general setting of an oriented Lagrangian submanifold of a 6-dimensional symplectic manifold.
Related
BibTeX
@misc{parker2026orientations,
title = {{Orientations for skein-valued curve counting}},
author = {Brett Parker},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.41233},
eprint = {2610.41233},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.41233},
}
RIS
TY - UNPB
TI - Orientations for skein-valued curve counting
AU - Brett Parker
PY - 2026
DA - 2026/10/30
PB - arXiv
DO - 10.48550/arxiv.2610.41233
UR - https://arxiv.org/abs/2610.41233
AB - Ekholm and Shende's skeins-on-branes formalism provides invariant counts of holomorphic curves with boundary on a Maslov zero Lagrangian within a Calabi-Yau 3-fold. This paper proves the orientation relations required for worldsheet skein relations to cancel codimension-one boundary strata. However, standard Cauchy-Riemann Fredholm orientations reveal an unexpected sign puzzle: the orientation relation at a curve with a hyperbolic boundary crossing depends on whether the crossing lies on distinct boundary components or the same component. This domain-dependent sign contradicts the uniform crossing relations of the HOMFLYPT skein algebra. We show that this discrepancy is resolved by passing to an anti-holomorphic orientation convention. We establish all required orientation comparisons in the general setting of an oriented Lagrangian submanifold of a 6-dimensional symplectic manifold.
ER -