The Algebra of Grand Unified Theories John C. Baez, John Huerta (Submitted on 9 Apr 2009) Abstract: The Standard Model of particle physics may seem complicated and arbitrary, but it has hidden patterns that are revealed by the relationship between three "grand unified theories": theories that unify forces and particles by extending the Standard Model symmetry group U(1) x SU(2) x SU(3) to a larger group. These three theories are Georgi and Glashow's SU(5) theory, Georgi's theory based on the group Spin(10), and the Pati-Salam model based on the group SU(2) x SU(2) x SU(4). In this expository account for mathematicians, we explain only the portion of these theories that involves finite-dimensional group representations. This allows us to reduce the prerequisites to a bare minimum while still giving a taste of the profound puzzles that physicists are struggling to solve. http://arxiv.org/abs/0904.1556 I been reading this paper yesterday and although an amateur i found it really interesting. correct me if i am wrong but do Baez en Huerta say that the standard model of particle physics is a subgroup of a deeper more fundemantal symmetry. And is there any relation with the Howard Georgi's idea of unparticle physics.