Well that's little complicated and incomplete as this is only one perspective. Other one is that edge really doesn't exist but universe is not infinite. Also it is not sure that if it is going to expand forever and ever and ever or it will stop at some moment and will it start contracting or not. But may be if we could get out of this universe we may be able to other universes. Because if we are living in universe, universe should also be placed somewhere. And there may be other universes too.

This theory was first put forward in 1962 and since then this theory had more pf opposers than supporters. According to a contrary theory which is based on relativity and Lorentz invariation, Tachyon is considered as a imaginary mass field rather than a faster than light speed particle. In these theories tachyon is named as tachyon condensation. It is formulated that the imaginary mass don't signifies faster than light speed particle but it signifies the unstablity of the field.

In special relativity, a faster than speed of light object will have space like four momentum rather than usual time like four momentum. In some theories and formulations the mass of tachyon is considered as imaginary and while in other as real. It is a matter of belief that what you want to consider or what is in accordance to your theory. Moreover, since tachyon is constrained to the space like portion of the energy-momentum graph, therefore it cannot slow down to subluminal speed.

Tachyon is a hypothetical particle with speed greater than the speed of light. Yes it os possible for a particle to aquire a speed greater than the speed of light itself. This particle has imaginary mass as observed which is in relation to the time-mass equation of Einstien. Hence giving a clue to something called imaginary mass which will have some after effects on the measurement in physics. Any particle with observed imaginary mass will be travelling at the speed greater than light.
Please share your views about this.