Letters in Mathematical Physics

, Volume 109, Issue 12, pp 2587–2600 | Cite as

Entropy of coherent excitations

  • Roberto LongoEmail author


We provide a rigorous, explicit formula for the vacuum relative entropy of a coherent state on wedge local von Neumann algebras associated with a free, neutral quantum field theory on the Minkowski spacetime of arbitrary spacetime dimension. We consider charges localised on the time-zero hyperplane, possibly crossing the boundary.


Quantum field theory Quantum information Operator algebras Entropy Quantum energy inequalities Modular theory 

Mathematics Subject Classification

81T05 46L60 81T40 46L37 



We thank the referee for pointing out a trivial calculation error in a previous version of this paper. We acknowledge the MIUR Excellence Department Project awarded to the Department of Mathematics, University of Rome Tor Vergata, CUP E83C18000100006.


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Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Dipartimento di MatematicaUniversità di Roma “Tor Vergata”RomeItaly

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