We suggest a new strategy for proving large N duality by interpreting
Gromov-Witten, Donaldson-Thomas and Chern-Simons invariants of a Calabi-Yau
threefold as different characterizations of the same holomorphic function. For
the resolved conifold this function turns out to be the quantum Barnes
function, a natural q-deformation of the classical one that in its turn
generalizes Euler's gamma function. Our reasoning is based on a new formula for
this function that expresses it as a graded product of q-shifted
multifactorials.Comment: 47 pages, 7 figure