I'm reading an introduction to relativity which uses different notation to the standard indices used in my college course.(adsbygoogle = window.adsbygoogle || []).push({});

I came across:

_{L(\nu)gL(\nu)g = 1}

Where L is the Lorentz transformations four-vector and g is the metric. Without the indices, I'm a little lost. Is there some convention I'm not aware of?

Also (I'm trying to remember my undergrad relativity) can someone remind me why the Minkowski metric has the sign system it does? I know you can choose (-,+,+,+) or (+,-,-,-) but I forget why the ct dimension has to be a different sign to the space dimensions.

Thanks in advance

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# Notation difficulties with metric and four vector

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