Conformal Algebra and Physical States in Non - critical 3 - brane on R × S 3

A world-volume model of non-critical 3-brane is quantized in a strong coupling phase where fluctuations of the conformal mode become dominant. This phase, called the conformal-mode dominant phase, is realized at the very high energy far beyond the Planck mass scale. We separately treat the conformal mode and the traceless mode and quantize the conformal mode non-perturbatively, while the traceless mode is treated in the perturbation which is renormalizable and asymptotically free. In the conformal-mode dominant phase, the coupling of the traceless mode vanishes and the world-volume dynamics is described as a four dimensional conformal field theory (CFT4). We canonically quantize this model on R × S3 where the dynamical fields are expanded using spherical tensor harmonics on S3. Conformal charges and conformal algebra are constructed. They give strong constraints on physical states. We find that all negative-metric modes are related to positive-metric modes through the charges so that they are not independent physical modes themselves. An infinite number of physical states satisfying the conformal invariance conditions are constructed. In appendix, we construct spherical vector, tensor harmonics on S3 in useable forms using the Wigner D-functions and the Clebsch-Gordan coefficients and calculate integrals of their products.