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arXiv · 0704.0258

Correlation functions in the Non Perturbative Renormalization Group and field expansion

Diego Guerra·Ramon Mendez-Galain·Nicolas Wschebor
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Abstract

The usual procedure of including a finite number of vertices in Non Perturbative Renormalization Group equations in order to obtain $n$-point correlation functions at finite momenta is analyzed. This is done by exploiting a general method recently introduced which includes simultaneously all vertices although approximating their momentum dependence. The study is performed using the self-energy of the tridimensional scalar model at criticality. At least in this example, low order truncations miss quantities as the critical exponent $η$ by as much as 60%. However, if one goes to high order truncations the procedure seems to converge rapidly.

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Diego Guerra, Ramon Mendez-Galain, Nicolas Wschebor. 2007-10-23. Correlation functions in the Non Perturbative Renormalization Group and field expansion. https://doi.org/10.1140/epjb/e2007-00296-x

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