Trace anomaly induced effective action for 2D and 4D dilaton coupled scalars

TL;DR

This paper computes trace anomalies and effective actions for dilaton-coupled scalars in 2D and 4D, providing tools for analyzing quantum effects in black holes, spherical collapse, and potential cosmological inflation.

Contribution

It derives trace anomalies and effective actions for dilaton-coupled scalars in 2D and 4D, extending previous models and exploring quantum back-reaction effects.

Findings

Derived trace anomaly and effective action for 2D dilaton scalars.

Constructed conformal sector for 4D dilatonic gravity.

Discussed quantum back-reaction possibly leading to inflation.

Abstract

The spherically symmetric reduction of higher dimensional Einstein-scalar theory leads to lower dimensional dilatonic gravity with dilaton coupled scalar (for example, from 4D to 2D system). We calculate trace anomaly and anomaly induced effective action for 2D and 4D dilaton coupled scalars. The large-N effective action for 2D quantum dilaton-scalar gravity is also found. These 2D results maybe applied for analysis of 4D spherical collapse. The role of new, dilaton dependent terms in trace anomaly for 2D black holes and Hawking radiation is investigated in some specific models of dilatonic gravity which represent modification of CGHS model. The conformal sector for 4D dilatonic gravity is constructed. Quantum back-reaction of dilaton coupled matter is briefly discussed (it may lead to the inflationary Universe with non-trivial dilaton).