# Quantum reference frames and deformed symmetries

 Title Quantum reference frames and deformed symmetries Publication Type Journal Article Year of Publication 2008 Authors Girelli, F, Poulin, D Journal Phys. Rev. D Volume 77 Pagination 104012 Keywords Foundations, Gravity, Reference frame Abstract In the context of constrained quantum mechanics, reference systems are used to construct relational observables that are invariant under the action of the symmetry group. Upon measurement of a relational observable, the reference system undergoes an unavoidable measurement back-action" that modifies its properties. In a quantum-gravitational setting, it has been argued that such a back-action may produce effects that are described at an effective level as a form of deformed (or doubly) special relativity. We examine this possibility using a simple constrained system that has been extensively studied in the context of quantum information. While our conclusions support the idea of a symmetry deformation, they also reveal a host of other effects that may be relevant to the context of quantum gravity, and could potentially conceal the symmetry deformation. Full Text