Nonperturbative renomalization group for Einstein gravity with matter

TL;DR

This paper explores the nonperturbative renormalization group in Einstein gravity with matter, revealing how scalar field properties influence gravitational coupling behavior.

Contribution

It introduces a truncated RG equation for Einstein gravity coupled to scalar fields, highlighting the dependence on scalar-gravitational coupling and number of fields.

Findings

Gravitational coupling exhibits screening or antiscreening behavior.

Behavior depends critically on scalar-gravitational coupling $\xi$.

Number of scalar fields affects the RG flow.

Abstract

we investigate the exact renormalization group (RG) in Einstein gravity coupled to N-component scalar field, working in the effective average action formalism and background field method. The truncated evolution equation is obtained for the Newtonian and cosmological constants. We have shown that screening or antiscreening behaviour of the gravitational coupling depends cricially on the choice of scalar-gravitational $\xi $ and the number of scalar fields.