Correlated double ramification cycle formula

Abstract

We prove a refinement of Pixton's formula for the double ramification cycle with target variety which takes into account the correlator of a rubber map previously introduced by the authors. To do so, we need to: reinterpret the correlator in terms of (logarithmic) roots of the trivial line bundle; refine the natural stratification of the boundary of moduli of maps to keep track of how torsion line bundles on the target variety pull-back. We apply the refined DR cycle formula to compute 0-correlated invariants for genus g curve with points and a $\lambda$-class insertion.