Zwiebach Equation 9.80: Why M^2 = -p^2?

Thread starter ehrenfest
Start date Oct 4, 2007

Oct 4, 2007

ehrenfest

Homework Statement

Can someone explain to me why in the world Zwiebach sets M^2 = -p^2 in this equation? Even in natural units, that doesn't seem right.

Homework Equations

The Attempt at a Solution

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Oct 5, 2007

Jimmy Snyder

Equation (9.80) is just equation (2.72) page 25, with c set to 1.

Oct 5, 2007

ehrenfest

I see. Thanks.

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