Equivalence of Adiabatic and DeWitt-Schwinger renormalization schemes

Abstract

We prove that adiabatic regularization and DeWitt-Schwinger point-splitting provide the same result for the renormalized expectation values of the stress-energy tensor for spin-$1/2$ fields. This generalizes the equivalence found for scalar fields, which is here recovered in a different way. We also argue that the coincidence limit of the DeWitt-Schwinger proper time expansion of the two-point function exactly agrees with the analogous expansion defined by the adiabatic regularization method at any order (for both scalar and spin-$1/2$ fields). We also illustrate the power of the adiabatic method to compute higher order DeWitt coefficients in FLRW universes.

Misprints corrected, small change in title

References in corpus (3)

• Perturbative Quantum Gravity Comes of Age
• Stress-Energy Tensor of Adiabatic Vacuum in Friedmann-Robertson-Walker Spacetimes
• Electric-magnetic duality and renormalization in curved spacetimes

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