Higher-derivative quantum gravity with matter in 4 — ε dimensions

The phase structure and IR properties of the higher-derivative quantum gravity (QG) with scalar matter in 4 — ε dimensions are investigated. The appearance of a few fixed points of the renormalization group (one of them is an infrared stable fixed point) is numerically shown. The new fixed points in 3 dimensions are associated with QG. The nature of phase transitions at nonzero temperature is discussed, and the improved effective potential is calculated.