Special Riemannian geometries modeled on distinguished symmetric spaces
arXiv:math/0603663
Abstract
We propose studies of special Riemannian geometries with structure groups , , and in respective dimensions 5, 8, 14 and 26. These geometries, have torsionless models with symmetry groups , , and . The groups and constitute a part of the `magic square' for Lie groups. Apart from the geometries in dimensions , the `magic square' Lie groups suggest studies of a finite number of other special Riemannian geometries. Among them the smallest dimensional are U(3) geometries in dimension 12. The other structure groups for these Riemannian geometries are: , U(6), , , , and . The respective dimensions are: 18, 30, 54, 28, 40, 64 and 112. This list is supplemented by the two `exceptional' cases of geometries in dimension 8 and geometries in dimension 32.
A written version of a talk at the workshop `Special geometries in mathematical physics' held in Kühlungsborn, March 2006