# Tag Info

## New answers tagged gauge-invariance

2

Of course, the metric $\eta_{\mu\nu}$ is not a unique solution for Einstein vacuum equations compatible with your given initial data. And yes, we can interpret the alternatives as arising from coordinate functions. Let us take the simplest of such function: redefine time by introducing new 'time' variable $\tau$ through a relation $t=f(\tau)$ (spacial ...

2

It's just not true that local gauge symmetry implies causality. That's a false statement. And, from what I can tell, the textbook you reference does not make this assertion. It only says that local gauge symmetry preserves causality, meaning that the two concepts are compatible.

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