PIRSA:14030114

Are superselection rules fundamental?

APA

Spekkens, R. (2014). Are superselection rules fundamental?. Perimeter Institute. https://pirsa.org/14030114

MLA

Spekkens, Robert. Are superselection rules fundamental?. Perimeter Institute, Mar. 14, 2014, https://pirsa.org/14030114

BibTex

          @misc{ pirsa_PIRSA:14030114,
            doi = {10.48660/14030114},
            url = {https://pirsa.org/14030114},
            author = {Spekkens, Robert},
            keywords = {Condensed Matter},
            language = {en},
            title = {Are superselection rules fundamental?},
            publisher = {Perimeter Institute},
            year = {2014},
            month = {mar},
            note = {PIRSA:14030114 see, \url{https://pirsa.org}}
          }
          

Robert Spekkens Perimeter Institute for Theoretical Physics

Collection
Talk Type Scientific Series

Abstract

Superselection rules in quantum theory assert the impossibility of preparing coherent superpositions of certain conserved quantities. For instance, it is commonly presumed that there is a superselection rule for charge and for baryon number, as well as a "univalence superselection rule" forbidding a coherent superposition of a fermion and a boson. I will show how many superselection rules can be effectively lifted using a reference frame for the variable that is conjugate to the conserved quantity. I will also discuss subtleties related to the univalence superselection rule.