Upper bounds of topology of complex polynomials in two variables
Abstract
Description
The paper deals with a complex polynomial $H$ in two variables having
- a generic highest homogeneous part (without multiple zero lines),
- nonconstant lower terms.
In particular, under these conditions the polynomial $H$ has at least two distinct critical values. We prove quantitative versions of this statement. Supposing $H$ appropriately normalized (by affine coordinate changes in the image and in the source) we prove upper bounds for the following quantities:
- the sum of the coefficients of the lower terms;
- the minimal size of a bidisc containing all the nontrivial topology of a given level curve $S_t=\{ H=t\}$;
- the minimal lengths of representatives of cycles in $H_1(S_t,\zz)$ vanishing along appropriate paths from $t$ to the critical values of $H$;
- the intersection indices of the latter cycles.
All these results (expect for the latter bound) are used in my joint work with Yu.S.Ilyashenko "Restricted version of the Hilbert 16-th problem" (available on the arxiv). In the latter paper we obtain an explicit upper bound of the number of zeros for a wide class of Abelian integrals.
51 pages
51 pages