English

Incidence strata of affine varieties with complex multiplicities

Algebraic Geometry 2019-03-13 v1

Abstract

To each affine variety XX and m1,,mkCm_1,\ldots,m_k\in \mathbb{C} such that no subset of the mim_i add to zero, we construct a variety which for m1,,mkNm_1,\ldots,m_k \in \mathbb{N} specializes to the closed (m1,,mk)(m_1,\ldots,m_k)-incidence stratum of Symm1++mkXSym^{m_1+\ldots+m_k}X. These fit into a finite-type family, which is functorial in XX, and which is topologically a family of C\mathbb{C}-weighted configuration spaces. We verify our construction agrees with an analogous construction in the Deligne category Rep(Sd)Rep(S_{d}) for dCd \in \mathbb{C}. We next classify the singularity locus and branching behaviour of colored incidence strata for arbitrary smooth curves. As an application, we negatively answer a question of Farb and Wolfson concerning the existence of an isomorphism between two natural moduli spaces.

Keywords

Cite

@article{arxiv.1903.05011,
  title  = {Incidence strata of affine varieties with complex multiplicities},
  author = {Hunter Spink and Dennis Tseng},
  journal= {arXiv preprint arXiv:1903.05011},
  year   = {2019}
}

Comments

27 pages, comments welcome!