We show that a
widely believed conjecture concerning rigidity of genus-zero and genus-one
holomorphic curves in Calabi–Yau threefolds implies a relation between the
genus-one GW-invariants of a quintic threefold in ℙ4 and the genus-zero and
genus-one GW-invariants of ℙ4. This relation is a special case of a general
formula for the genus-one GW-invariants of complete intersections obtained in
a previous paper. In contrast to the general case, this paper’s derivation
is more geometric and makes direct use of the rigidity property. Thus, it
provides further evidence for the rigidity conjecture in low genera. On the
other hand, this paper also suggests a potential way of disapproving the less
commonly believed generalization of the rigidity conjecture to arbitrary
genus.
Keywords
quintic threefold, Gromov–Witten invariants, genus one