English

Towards relative invariants of real symplectic 4-manifolds

Symplectic Geometry 2007-05-23 v1 Algebraic Geometry

Abstract

Let (X,ω,cX)(X, \omega, c_X) be a real symplectic 4-manifold with real part RXR X. Let LRXL \subset R X be a smooth curve such that [L]=0H1(RX;Z/2Z)[L] = 0 \in H_1 (R X ; Z / 2Z). We construct invariants under deformation of the quadruple (X,ω,cX,L)(X, \omega, c_X, L) by counting the number of real rational JJ-holomorphic curves which realize a given homology class dd, pass through an appropriate number of points and are tangent to LL. As an application, we prove a relation between the count of real rational JJ-holomorphic curves done in math.AG/0303145 and the count of reducible real rational curves done in math.SG/0502355. Finally, we show how these techniques also allow to extract an integer valued invariant from a classical problem of real enumerative geometry, namely about counting the number of real plane conics tangent to five given generic real conics.

Keywords

Cite

@article{arxiv.math/0502358,
  title  = {Towards relative invariants of real symplectic 4-manifolds},
  author = {Jean-Yves Welschinger},
  journal= {arXiv preprint arXiv:math/0502358},
  year   = {2007}
}

Comments

21 pages, 8 figures