Abstract
Of the contributions to the cosmological constant, zero-point energy contributions scale as ${\ensuremath{\delta}}^{4}(0)\ensuremath{\sim}{\mathrm{\ensuremath{\Lambda}}}^{4}$ where $\mathrm{\ensuremath{\Lambda}}$ is an ultraviolet cutoff used to regulate the calculations. I show that such contributions vanish when calculated in perturbation theory. This demonstration uses a little-known modification to perturbation theory found by Honerkamp and Meetz and by Gerstein, Jackiw, Lee, and Weinberg which comes into play when using cutoffs and interactions with multiple derivatives, as found in chiral theories and gravity. In a path integral treatment, the new interaction arises from the path integral measure and cancels the ${\ensuremath{\delta}}^{4}(0)$ contributions. This reduces the sensitivity of the cosmological constant to the high energy cutoff, although it does not resolve the cosmological constant problem. The feature removes one of the common motivations for supersymmetry. It also calls into question some of the results of the asymptotic safety program. Covariance and quadratic cutoff dependence are also briefly discussed.
Highlights
In regularizing quantum field theories, dimensional regularization is the most common and useful choice, partially because it preserves all the symmetries of the theory
Cutoffs play a role in our thinking about physics
We think of effective field theories as being valid up to some energy scale, and a cutoff can parametrize the limit of validity of the effective field theory
Summary
In regularizing quantum field theories, dimensional regularization is the most common and useful choice, partially because it preserves all the symmetries of the theory. I describe how direct calculations of the cosmological constant using a cutoff differ from our common description, and show the need for a new interaction term when using cutoffs with gravity. If we calculate all the components of the energy momentum tensor using canonical quantization, we find the Λ4 contribution to the vacuum values is. Since the contribution to the cosmological constant can be identified with the trace of the energy momentum tensor. The covariance problem can be resolved by using quantum field theory (QFT) to calculate the contribution to the cosmological constant. In this paper I will show that even the above QFT calculation is wrong—that, there are no perturbative δ4ð0Þ ∼ Λ4 zero-point contributions to the cosmological constant. This was shown by Fradkin and Vilkovisky [3].2 The new interaction is proportional to iδ4ð0Þ log detð−gμνÞ, where δ4ð0Þ is δ4ðxÞ evaluated at x 1⁄4 0, and is relevant in any regularization scheme where the regularized value of δ4ð0Þ is nonzero
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