PIRSA:18060003

Soft photons, gravitons, and their quantum information content

Carney, D. (2018). Soft photons, gravitons, and their quantum information content. Perimeter Institute. https://pirsa.org/18060003

Carney, Daniel. Soft photons, gravitons, and their quantum information content. Perimeter Institute, Jun. 06, 2018, https://pirsa.org/18060003 

          @misc{ pirsa_PIRSA:18060003,
            doi = {10.48660/18060003},
            url = {https://pirsa.org/18060003},
            author = {Carney, Daniel},
            keywords = {Quantum Information},
            language = {en},
            title = {Soft photons, gravitons, and their quantum information content},
            publisher = {Perimeter Institute},
            year = {2018},
            month = {jun},
            note = {PIRSA:18060003 see, \url{https://pirsa.org}}
          }

Daniel Carney

University of Maryland, College Park

Talk number
PIRSA:18060003
Collection
Talk Type
Subject
Abstract

When a particle is accelerated, as in a scattering event, it will radiate gravitons and, if electrically charged, photons. The infrared tail of the spectrum of this radiation has a divergence: an arbitrarily small amount of total energy is divided into an arbitrarily large number of radiated bosons. Each of these in turn carries a momentum and a helicity degree of freedom, and thus this radiation carries significant amounts of quantum information. I will demonstrate that the infrared bosonic radiation causes nearly complete decoherence of the final state of the hard particles into the momentum basis. When applied to radiation coming from the incoming state, it appears that the entire dynamical history of the process will be distinguishable by the radiation, thus causing a loss of any interference effects between branches of an incoming momentum superposition, such as in a wavepacket. I will explain how infrared dressed states, in the framework of Fadeev and Kulish, evade this issue. Finally, I'll conclude with some remarks on the potential relevance of these issues to black hole information loss