Journal of High Energy Physics

, 2012:88

A ground state for the causal diamond in 2 dimensions

  • Niayesh Afshordi
  • Michel Buck
  • Fay Dowker
  • David Rideout
  • Rafael D. Sorkin
  • Yasaman K. Yazdi
Article

DOI: 10.1007/JHEP10(2012)088

Cite this article as:
Afshordi, N., Buck, M., Dowker, F. et al. J. High Energ. Phys. (2012) 2012: 88. doi:10.1007/JHEP10(2012)088

Abstract

We apply a recent proposal for a distinguished ground state of a quantum field in a globally hyperbolic spacetime to the free massless scalar field in a causal diamond in two-dimensional Minkowski space. We investigate the two limits in which the Wightman function is evaluated (i) for pairs of points that lie in the centre of the diamond (i.e. far from the boundaries), and (ii) for pairs of points that are close to the left or right corner. We find that in the centre, the Minkowski vacuum state is recovered, with a definite value of the infrared cutoff. Interestingly, the ground state is not the Rindler vacuum in the corner of the diamond, as might have been expected, but is instead the vacuum of a flat space in the presence of a static mirror on that corner. We confirm these results by numerically evaluating the Wightman function of a massless scalar field on a causal set corresponding to the continuum causal diamond.

Keywords

Field Theories in Lower Dimensions Nonperturbative Effects Lattice Quantum Field Theory Stochastic Processes 

Copyright information

© SISSA, Trieste, Italy 2012

Authors and Affiliations

  • Niayesh Afshordi
    • 1
    • 2
  • Michel Buck
    • 3
  • Fay Dowker
    • 2
    • 3
    • 4
  • David Rideout
    • 5
  • Rafael D. Sorkin
    • 2
    • 6
  • Yasaman K. Yazdi
    • 1
  1. 1.Department of Physics and AstronomyUniversity of WaterlooWaterlooCanada
  2. 2.Perimeter Institute for Theoretical PhysicsWaterlooCanada
  3. 3.Blackett Laboratory, Imperial CollegeLondonU.K.
  4. 4.Institute for Quantum ComputingUniversity of WaterlooWaterlooCanada
  5. 5.Department of MathematicsUniversity of California San DiegoLa JollaU.S.A.
  6. 6.Department of PhysicsSyracuse UniversitySyracuseU.S.A.

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