In this talk we review the physics of top-quark mass generation in models of dynamical electroweak symmetry breaking and the constraints on this physics arising from limits on the deviation of the weak interaction ρ-parameter from one. We then discuss top-color assisted technicolor in this context. 1. mt in Models of Dynamical Electroweak Symmetry Breaking In technicolor models, the masses of t...

Symmetries play an important role in dynamical systems. They provide quantum numbers for the classification of states, determine selection rules and facilitate the calculation of matrix elements. An exact symmetry occurs when the Hamiltonian of the system commutes with all the generators (gi) of the symmetry-group, [H , gi ] = 0. In this case, all states have good symmetry and are labeled by th...