Graduate Semicolon notation in component of covariant derivative

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The discussion centers on the use of semicolon notation in the context of covariant derivatives, specifically in the expression S^\alpha{}_{\beta\gamma;\delta} = \nabla_\delta \, S^{\alpha}{}_{\beta\gamma}. Participants clarify that the semicolon indicates a covariant derivative and can be seen as a compact notation for the components of a tensor. The conversation also touches on how any tensor can be expressed as a sum of its components multiplied by basis vectors and co-vectors. Additionally, a user inquires about the method for typing equations, leading to a recommendation to use the site's LaTeX feature. Understanding the semicolon notation is essential for grasping covariant derivatives in tensor calculus.
berlinspeed
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The use of semicolon notation as covariant derivative
Can someone clarify the use of semicolon in
245677

I know that semicolon can mean covariant derivative, here is it being used in the same way (is
245678
expandable?) Or is
245679
a compact notation solely for the components of
245680
?
 
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If you're familiar with index or abstract index notation

$$S^\alpha{}_{\beta\gamma;\delta} = \nabla_\delta \, S^{\alpha}{}_{\beta\gamma}$$
 
berlinspeed said:
Can someone clarify the use of semicolon in
View attachment 245677
I know that semicolon can mean covariant derivative, here is it being used in the same way (is View attachment 245678 expandable?) Or isView attachment 245679 a compact notation solely for the components ofView attachment 245680?
Not sure what your confusion is. Any tensor can be written as the sum of each of its components in some basis multiplied by the outer product of the respective basis vectors and co-vectors. Since the covariant derivative of a tensor is still a tensor (but one rank higher), it can also be written this way. Does that clear anything up for you?
 
pervect said:
If you're familiar with index or abstract index notation

$$S^\alpha{}_{\beta\gamma;\delta} = \nabla_\delta \, S^{\alpha}{}_{\beta\gamma}$$
Hello thank you, can you tell me what did you use to type your equations? I'm new to this site and trying to find a good way to generate equations. Much appreciated.
 
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In an inertial frame of reference (IFR), there are two fixed points, A and B, which share an entangled state $$ \frac{1}{\sqrt{2}}(|0>_A|1>_B+|1>_A|0>_B) $$ At point A, a measurement is made. The state then collapses to $$ |a>_A|b>_B, \{a,b\}=\{0,1\} $$ We assume that A has the state ##|a>_A## and B has ##|b>_B## simultaneously, i.e., when their synchronized clocks both read time T However, in other inertial frames, due to the relativity of simultaneity, the moment when B has ##|b>_B##...

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