The Hillman-Grassl correspondence and the enumeration of reverse plane partitions

Hillman and Grassl have devised a correspondence between reverse plane partitions and nonnegative integer arrays of the same shape that allowed them to easily enumerate reverse plane partitions and provided a combinatorial connection between hook lengths and plane partitions. In this work, a collection of properties of this correspondence are presented, including two characterizations that relate this map to the familiar Schensted-Knuth correspondence. These properties are used to derive simple expressions for the generating functions of reverse plane partitions and symmetric reverse plane partitions with respect to sums along the diagonals. Equally general results are obtained for shifted reverse plane partitions using a new type of hook, thereby proving a conjecture of Stanley.