Study of Gram Matrices in Fock Representation of Multiparametric Canonical Commutation Relations, Extended Zagier's Conjecture, Hyperplane Arrangements and Quantum Groups

In this Colloqium Lecture (by one of the authors (D.S)) a thorough presentation of the authors' research on the subjects, stated in the title, is given. By quite laborious mathematics it is explained how one can handle systems in which each Heisenberg commutation relation is deformed separately. For Hilbert space realizability a detailed determinant computations (extending Zagier's one-parameter formulas) are carried out. The inversion problem of the associated Gram matrices on Fock weight spaces is completely solved (Extended Zagier's conjecture) and a counterexample (for $n=8$) to the original Zagier's conjecture is presented in detail.