
Calendar of Physics Talks Vienna
MAKING SENSE OF NONHERMITIAN HAMILTONIANS 
Speaker:  Prof. Carl M. Bender (Washington University in St. Louis) 
Abstract:  The average quantum physicist on the street believes that a quantummechanical Hamiltonian must be Dirac Hermitian in order to guarantee that the energy eigenvalues are real and that time evolution is unitary. However, the Hamiltonian H=p^2+ix^3, which is obviously not Dirac Hermitian, has a real positive discrete spectrum and generates unitary time evolution, and thus it defines a fully consistent and physical quantum theory! Evidently, the axiom of Dirac Hermiticity is too restrictive. While H=p^2+ix^3 is not Dirac Hermitian, it is PT symmetric; that is, invariant under combined space reflection P and time reversal T. The quantum mechanics defined by a PTsymmetric Hamiltonian is a complex generalization of ordinary quantum mechanics. When quantum mechanics is extended into the complex domain, new kinds of theories having strange and remarkable properties emerge. 
Date:  Fri, 15.07.2011 
Time:  14:00 
Duration:  60 min 
Location:  Seminar room 136, Freihaus, 10th floor (yellow section), Wiedner Hauptstraße 810 
Contact:  Stefan Rotter 
