During inflation,   mass and radiation ‘sprung’ up via                               uncertainty principle Heisenberg :       DE Dt = h / 2p                             DE = Dm c2                                                                      => Dm Dt  = h / 2p   for a short time, can non-conserve mass   => virtual pairs (p+ p-    e-e+)
	p+ + p-         g  +  g  g  +  g        p+ + p-