The linked paper
http://arxiv.org/PS_cache/arxiv/pdf/0801/0801.2639v1.pdf has something very odd in it. I hope someone can clear up what seems a very basic error in the paper.
In equation (2) the paper clearly states \gamma = (1-u^2/c^2)^{-1/2}
In equation (7) the paper states m = m_o \cdot \gamma = m_o \cdot (1-u^2/c^2)^{-1/2}
So far, this all very classic relativity but perhaps a bit old fashioned in using the relativistic mass increase concept. Nevetheless we note that by the expression m_o dot gamma they mean an increase of mass with increase of relative velocity.
Now just before equation (26) the paper states:
"Using the above expression for G, the fact that p is a Lorentz invariant, i.e. p = p0, and the change of volume by Lorentz contraction, V = V_o \cdot \gamma , one can integrate the above expression and get.."
Now of course I am very happy that they assume that pressure is invariant as everyone here knows that is my belief, but by V_o dot gamma they must be implying an increase of volume with increase of relative velocity. Is that not the opposite of length contraction and therefore a mistake? Maybe it is me that missing something basic?