Jan Ambjørn is a Danish physicist regarded as the primary founder of Causal Dynamical Triangulation Theory (CDT). Ambjørn began in the early 1990s searching for a physics model that bonded quantum mechanics and relativistic gravity in a way that didn't require supersymmetry. By 1994, he argued a simpler way to represent quantum gravity was to use Lorentzian space-time geometry as a framework. His first major publication on the lattice model that would become CDT theory was released in 1998. It was then that he and Renate Loll made triangulation and the causal approach the cornerstones to the lattice gauge theory.