Tachyonic Energies in a Minkowski Metric

1. Jan 31, 2012

gravitowell

So I'm working on a problem (Hartle problem 6, chapter 6) dealing with tachyons. So far, I have determined the four-velocity and the four-momentum (up to a sign) of a tachyon. I have, with the four-velocity being a unit spacelike four-vector,
$u^{\alpha}=\frac{\pm 1}{\sqrt{\vec{V}^2-1}}(1,\vec{V})$

I don't want to just assume the positive values of $u^{\alpha}$.

I need help figuring out how to find the energy E given that p=mu.

I realize I may have not phrased my dilemma well, so please ask for clarification.

2. Jan 31, 2012

elfmotat

I couldn't find this problem in Hartle. Problem 6 in chapter 6 is about transforming into the coordinates of an accelerated frame. I'm also not really sure what your question is.

3. Jan 31, 2012

Nabeshin

Don't really have time to comment on the OP's dilemma, but I believe it's ch.5 problem 23.

4. Feb 1, 2012

gravitowell

Yes, you're right. I was about to change it. Thanks for noting.

5. Feb 1, 2012

gravitowell

I figured it out. I found my energy-momentum for tachyons to be given by

E^2=p^2-m^2.