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arXiv · 2303.16719

Scalar spectral functions from the spectral fRG

Jan Horak·Friederike Ihssen·Jan M. Pawlowski·Jonas Wessely·Nicolas Wink
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Abstract

We compute non-perturbative spectral functions in a scalar $\phi^4$-theory in three spacetime dimensions via the spectral functional renormalisation group. This approach allows for the direct, manifestly Lorentz covariant computation of correlation functions in Minkowski spacetime, including a physical on-shell renormalisation. We present numerical results for the spectral functions of the two- and four-point correlation functions for different values of the coupling parameter. These results agree very well with those obtained from another functional real-time approach, the spectral Dyson-Schwinger equation.

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Jan Horak, Friederike Ihssen, Jan M. Pawlowski, Jonas Wessely, Nicolas Wink. 2023-03-29. Scalar spectral functions from the spectral fRG. https://arxiv.org/abs/2303.16719

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