Hi, all(adsbygoogle = window.adsbygoogle || []).push({});

I'm reading peskin by myself.

I can't understand from eq(3.50) to eq(3.53).

i) What should I interpret [itex]\sqrt{p\cdot\sigma}[/itex]?

I guess below, but I can't understand [itex]\sqrt{\;\;}[/itex] of matrices.

\begin{eqnarray}

p\cdot\sigma=E \left(\begin{array}{cc} 1 & 0 \\ 0 & 1 \end{array}\right) - p^3\left(\begin{array}{cc} 1 & 0 \\ 0 & -1 \end{array}\right) \\

= \left(\begin{array}{cc} E-p^3 & 0 \\ 0 & E+p^3 \end{array}\right)

\end{eqnarray}

And why is it the same as (3.49)?

ii)How can I confirm (3.50) is a solution of the Dirac equation?

iii)What's meaning of "large boost" in (3.52) and (3.53)?

If I understand the Dirac spinor more, is it easy transform?

When so, where can I study Dirac spinor easily?

Thanks in advance!

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# Peskin page 46 to 47

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