(adsbygoogle = window.adsbygoogle || []).push({}); From Schutz'sA First Course in General Relativity

"A particle of rest massmmoves with velocityvin thexdirection of frameO. What are the components of the four-velocity and four-momentum?"

By definition [tex] \vec{U} = \vec{e}_{\bar{0} [/tex]

However, I don't see how he gets [tex] U^{\alpha} = \Lambda^{\alpha}_{\bar{\beta}}(\vec{e}_{\bar{0}})^{\bar{\beta}} = \Lambda^{\alpha}_{\bar{0}} [/tex]

Where [tex] \vec{U} [/tex] is the four-velocity vector, and [tex] U^{\alpha} [/tex] are its components.

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# Four-Velocity & Momentum

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