A Lorentz transformation is a four-dimensional transformation x^, μ = Λ^μ _ν x^ν, satisfied by all four-vectors x^ν, where Λ^μ _ν is a so-called Lorentz tensor. Lorentz tensors are restricted by the conditions Λ^α _γ Λ^β _δ η_αβ = η_γδ, with η_αβ the Minkowski metric (Weinberg 1972, p. 26; Misner et al. 1973, p. 68).