@article{BeniniCapoferriDappiaggi2017,
  author    = {Benini, Marco and Capoferri, Matteo and Dappiaggi, Claudio},
  title     = {Hadamard States for Quantum Abelian Duality},
  series = {Annales de l'Institut Henri Poincar{\´e}},
  volume    = {18},
  journal   = {Annales de l'Institut Henri Poincar{\´e}},
  publisher = {Springer},
  address   = {Basel},
  issn      = {1424-0637},
  doi       = {10.1007/s00023-017-0593-y},
  pages     = {3325 -- 3370},
  year      = {2017},
  abstract  = {Abelian duality is realized naturally by combining differential cohomology and locally covariant quantum field theory. This leads to a -algebra of observables, which encompasses the simultaneous discretization of both magnetic and electric fluxes. We discuss the assignment of physically well-behaved states on this algebra and the properties of the associated GNS triple. We show that the algebra of observables factorizes as a suitable tensor product of three -algebras: the first factor encodes dynamical information, while the other two capture topological data corresponding to electric and magnetic fluxes. On the former factor and in the case of ultra-static globally hyperbolic spacetimes with compact Cauchy surfaces, we exhibit a state whose two-point correlation function has the same singular structure of a Hadamard state. Specifying suitable counterparts also on the topological factors, we obtain a state for the full theory, ultimately implementing Abelian duality transformations as Hilbert space isomorphisms.},
  language  = {en}
}