Warping with dilatation symmetry and self-tuning of the cosmological constant

Understand

We investigate consequences of an ultraviolet fixed point in quantum gravity for the cosmological constant.

• For this purpose we perform dimensional reduction of a general dilatation symmetric effective action $\Gamma$ in dimension $d>4$ to an effective four-dimensional theory of gravity with a dilaton field.
• We find a stable flat phase in the space of extrema of $\Gamma$ which results in a vanishing four-dimensional cosmological constant $\Lambda$.
• In order to understand the self-tuning mechanism leading to $\Lambda = 0$ we discuss in detail the most general warped geometries with maximal four-dimensional symmetry and $SO(d-4)$ isometry of internal space.