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How unique is the expected stress-energy tensor of a massive scalar field?

Wolfgang Tichy·Eanna E. Flanagan
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Abstract

We show that the set of ambiguities in the renormalized expected stress-energy tensor allowed by the Wald axioms is much larger for a massive scalar field (an infinite number of free parameters) than for a massless scalar field (two free parameters). We also use the closed-time-path effective action formalism of Schwinger to calculate the expected value of the stress-energy tensor in the incoming vacuum state, for a massive scalar field, on any spacetime which is a linear perturbation off Minkowski spacetime. This result generalizes an earlier result of Horowitz and also Jordan in the massless case, and can be used as a testbed for comparing different calculational methods.

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Wolfgang Tichy, Eanna E. Flanagan. 1998-08-21. How unique is the expected stress-energy tensor of a massive scalar field?. https://doi.org/10.1103/physrevd.58.124007

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