English

Bivariate systems of polynomial equations with roots of high multiplicity

Algebraic Geometry 2021-10-26 v4 Combinatorics

Abstract

Given a bivariate system of polynomial equations with fixed support sets A,BA, B it is natural to ask which multiplicities its solutions can have. We prove that there exists a system with a solution of multiplicity ii for all ii in the range {0,1,...,A\mboxconv(A)B1}\{0,1,...,|A|-|\mbox{conv}(A)\ominus B|-1\}, where ABA\ominus B is the set of all integral vectors that shift B to a subset of AA. As an application of this result we classify all pairs (A,B)(A, B) such that the system supported at (A,B)(A, B) does not have a solution of multiplicity 33.

Keywords

Cite

@article{arxiv.1910.12541,
  title  = {Bivariate systems of polynomial equations with roots of high multiplicity},
  author = {I. Nikitin},
  journal= {arXiv preprint arXiv:1910.12541},
  year   = {2021}
}

Comments

26 pages, 11 figures (In the version 3 the classification in the theorem 4.2 was incomplete. In version 4 this bug is fixed)