(Quantum) gravity effects via exotic ℝ 4

Abstract

The arguments are given that exotic smooth ℝ4's can be considered as the natural counterpart for geometry of quantum gravity in some limits. This follows from the relations of these exotics to ℤ2 orientifolds of WZW models on SU(2), abelian gerbes on S3, generalized Hitchin's–Gualtieri structures as well gerbes on some orbifolds. Non-standard smoothings of ℝ4 seem to carry also quantum information about spacetime and gravity.