In Special Relativity, you learn that invariant mass is computed by taking the difference between energy squared and momentum squared. (For simplicity, I'm saying c = 1).
m^2 = E^2 - \vec{p}^2
This can also be written with the Minkowski metric as:
m^2 = \eta_{\mu\nu} p^\mu p^\nu
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Can anyone help me find any mistake in this expansion ? (I've asked it also in other places but I got no answer))
Pα= e Fαβ Uβ
c = speed of light
m = "rest" mass
e = charge
a = sqr(1 - v2/c2)
v2 = vx2 + vy2 + vz2
dτ = dt a (proper time)
momentum 4 vector : Pα = [mc/a , mvx/a , mvy/a ...