English

Free resolutions for multiple point spaces

Algebraic Geometry 2014-03-28 v1

Abstract

Let f be a map-germ of corank 1 from complex n-space to complex (n+1)-space, and, for k less than or equal to the multiplicity of f, let Dk(f)D^k(f) be its k'th multiple-point scheme -- the closure of the set of ordered k-tuples of pairwise distinct points sharing the same image. There are natural projections from Dk+1(f)D^{k+1}(f) to Dk(f)D^k(f), determined by forgetting one member of the (k+1)-tuple. We prove that the matrix of a presentation of \OODk+1(f)\OO_{D^{k+1}(f)} over \OODk(f)\OO_{D^k(f)} appears as a certain submatrix of the matrix of a suitable presentation of \OO\CCn\OO_{\CC^n} over \OO\CCn+1\OO_{\CC^{n+1}}. This does not happen for germs of corank greater than 1.

Keywords

Cite

@article{arxiv.1111.2909,
  title  = {Free resolutions for multiple point spaces},
  author = {Ayse Altintas and David Mond},
  journal= {arXiv preprint arXiv:1111.2909},
  year   = {2014}
}

Comments

15 pages

R2 v1 2026-06-21T19:35:05.231Z