On the strong DR/DZ equivalence conjecture
Xavier Blot, Danilo Lewanski, Sergey Shadrin
TL;DR
This work proves the strong DR/DZ equivalence by showing that, for a semi-simple CohFT, the Dubrovin–Zhang hierarchy is Miura-equivalent to Buryak’s double ramification hierarchy after a normal Miura transformation driven by a specific differential polynomial. Central to the argument is the A=B tautological relation, reformulated via the master relation in the Gorenstein quotient and expressed through leveled, degree-labeled trees with $B$- and $A$-type classes. The authors establish three key degree-vanishing statements for intersection numbers involving these classes, reducing the problem to combinatorial and tautological-geometry arguments, and then relate the master relation to the DR/DZ equivalence. As a corollary, the results extend to partial and F-CohFTs, remove the semi-simplicity assumption in many cases, and imply the existence and polynomiality of the DZ hierarchy in broader settings, thereby unifying two fundamental integrable systems in enumerative geometry with a concrete, computable linking map.
Abstract
We establish the Miura equivalence of two integrable systems associated to a semi-simple cohomological field theory: the double ramification hierarchy of Buryak and the Dubrovin-Zhang hierarchy. This equivalence was conjectured by Buryak and further refined by Buryak, Dubrovin, Guéré, and Rossi.
