Im reading "A first course in String Theory" by Zwiebach and it says that when applying a gauge parametrization in the form of [tex] n_\mu X^\mu = \lambda \tau[/tex] we can take the vector [tex] n_\mu [/tex] so that for open strings connected to branes (fixed end points), [tex] n^\mu \mathcal{P}^\tau _\mu [/tex] is conserved. But in general momentum is not conserved over the string for dirchlet boundary conditions as I understand, so how does applying the general \tau gauge make it so that it is. How can we chose a gauge that will conserve momentum on the string. The string is still going to be connected to a brane, and without considering the dynamics of the brane I dont see how this can be ensured.(adsbygoogle = window.adsbygoogle || []).push({});

Thanks,

B

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# Homework Help: Momentum conservation under a Gauge Parametrization in string theory

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