Positive product formulas and hypergroups associated with singular Sturm-Liouville problems on a compact interval
Properties of eigenfunctions of non-local operators
Properties of non-hermitian quantum field theories
In this paper I discuss quantum systems whose Hamiltonians are non-Hermitian but whose energy levels are all real and positive. Such theories are required to be symmetric under , but not symmetric under and separately. Recently, quantum mechanical systems having such properties have been investigated in detail. In this paper I extend the results to quantum field theories. Among the systems that I discuss are and theories. These theories all have unexpected and remarkable properties. I discuss...