On unimodular quantum gravity

Understand

Unimodular gravity is classically equivalent to standard Einstein gravity, but differs when it comes to the quantum theory: The conformal factor is non-dynamical, and the gauge symmetry consists of transverse diffeomorphisms only.

• Furthermore, the cosmological constant is not renormalized.
• Thus the quantum theory is distinct from a quantization of standard Einstein gravity.
• Here we show that within a truncation of the full Renormalization Group flow of unimodular quantum gravity, there is a non-trivial ultraviolet-attractive fixed point, yielding a UV completion for unimodular gravity.