Fundamental Forces as Gauge Theories

This study proposes that all the known fundamental forces including gravity may be described by local gauge theories. Gravitational, electroweak, and strong interactions on length scales from 10^{-33} cm to 10^{28} cm are systematically discussed from the unified gauge theory point of view toward a ultimate theory for fundamental forces. New concepts such as dynamical spontaneous symmetry breaking, gauge group hierarchy, coupling constant hierarchy, effective coupling constant hierarchy, cosmological constant, massive gauge bosons, massless gauge bosons, quantum weakdynamics, analogy between quantum weakdynamics and quantum chromodynamics, a possible gauge theory for the universe expansion, the relation between time and gauge boson mass, other quantum tests, etc. are briefly reported based on experiments.