2011/05/16 by Justo López-Sarrión, Justo Lopez-Sarrion, Lopez-Sarrion, Justo +2
Mathematics · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Quantum Mechanics and Non-Hermitian Physics #Quantum Physics (quant-ph) #Quantum chaos and dynamical systems #Spectral Theory in Mathematical Physics #hep-th #quant-ph
paper · pdf · doi:10.48550/arxiv.1105.3243
4 pages
arxiv created 2011/05/16 · openalex publication_date 2011/05/16 · arxiv updated 2011/05/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We show that statistics is crucial for the instability problem derived from higher time derivatives. In fact, and contrary to previous statements, we check that when dealing with Fermi systems, the Hamiltonian is well bounded and the quantum states are normalizable. Although, ghost states are still present, they do not affect unitarity under certain conditions. We first analyze a quantum oscillator involving Grassman variables and then we generalize it to a Dirac field. Finally, we discuss some physical implications