Massless fields infinitely degenerating with respect to the helicity and their effects in astrophysics

A tachyon field having a negative squared-mass $-m_t^2$ can be described in terms of massless fields degenerating infinitely with respect to the helicity. The degeneracy leads symmetry breakings of space-time. This picture for the tachyon does not contradict causality. The tachyon vector-field is quenched from the interactions with matter fields, and the effects can be represented by a phase factor. The accelerated expansion of the universe and the dark energies are interpreted in terms of the phase factor. An asymmetry between the distribution of particles and that of anti-particles in the universe is also derived from the phase. Membranes can be described by the tachyon wave packet.