Dedicated by the first and the third authors to the memory of the second author, with gratitude for his friendship and for all they learnt from him
AbstractIn this paper, we construct noncommutative coherent states using various families of unitary irreducible representations (UIRs) of G nc , a connected, simply connected nilpotent Lie group, that was identified as the kinematical symmetry group of noncommutative quantum mechanics for a system of 2-degrees of freedom in an earlier paper. Likewise described are the degenerate noncommutative coherent states arising from the degenerate UIRs of G nc . We then compute the reproducing kernels associated with both these families of coherent states and study Berezin-Toeplitz quantization of the observables on the underlying 4-dimensional phase space, analyzing in particular the semi-classical asymptotics for both these cases.
I IntroductionNoncommutative quantum mechanics (NCQM) is an active field of research these days. The starting point here is to alter the canonical commutation relations (CCR) among the * shhchowdhury@gmail.com † twareque.ali@concordia.ca ‡ englis@math.cas.cz 1 respective positions and momenta coordinates and hence introduce a new noncommutative Lie algebra structure. Consult [13,8] for a detailed account on this approach. There is another approach available where one starts with noncommutative field theory (NCFT) studying quantum field theory on noncommutative space-time. An excellent pedagogical treatment to noncommutative quantum field theory can be found in [15]. Refer to the excellent review [9] to delve further into the studies of NCFT. A noncommutative quantum field theory is the one where the fields are functions of space-time coordinates with spatial coordinates failing to commute with each other. Among others, Snyder and Yang were the leading proponents to introduce the concept of noncommutative structure of space-time (see [14,16]). Introduction of such assumption of spatial noncommutativity eliminates ultraviolet (UV) divergences of quantum field theory and runs parallel to the technique of renormalization as a cure to such annoying divergence issues in quantum field theory. NCQM can then be seen as nonrelativistic approximation of NCFT (see [10, 3]).In yet another approach (see [4], [5]), the authors start from a certain nilpotent Lie group G nc as the defining group of NCQM for a system of 2 degrees of freedom and compute its unitary dual using the method of orbits introduced by Kirillov (see [11]). Although G nc does not contain the Weyl-Heisenberg group G WH as its subgroup, the unitary dual of G WH is found to be sitting inside that of G nc . Various gauges arising in NCQM are also found to be related to a certain family of unitary irreducible representations (UIRs) of G nc . The Lie group G nc was later identified as the kinematical symmetry group of NCQM in [6] where various Wigner functions for such model of NCQM were computed that were found to be supported on relevant families of coadjoint orbits associated with G nc . The purp...