Possible Upper limits on Lorentz Factors in High Energy Astrophysical Processes

Gamma ray bursts (GRBs) are the most luminous physical phenomena in the universe. The relativistic effect on the blast wave associated with the GRB introduces the gamma factor. Here we put an upper limit on the gamma factor via constraints on maximal power allowed by general relativity and hence set upper limits on other observable quantities such as deceleration distance. Also upper limits are set on the high energy particle radiation due to constraints set by cosmic microwave background radiation.