Brian Greene

Brian Greene, author of The Elegant Universe and professor at Columbia University since 1996, is one of the most famous proponents of string theory.

Greene's most significant contribution to string theory is his application of Calabi-Yau manifolds to string theory's extra dimensions. According to Greene, these manifolds describe the shape of the extra dimensions.

When string theory's extra dimensions take on the form of Calabi-Yau manifolds, the theory retains an important symmetry called "conformal invariance".