Towards formulating an invariant Lagrangian

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SUMMARY

The discussion centers on the formulation of an invariant Lagrangian, specifically examining the relationship between two equations involving complex coordinates and derivatives. The Lagrangian is proposed as proportional to the terms involving derivatives of a scalar field σ and a complex matrix G. The main inquiry is whether the substitution of G from the second equation into the first is valid, given the differing degrees of freedom in the summation of derivatives. Participants clarify that the direct substitution may not hold due to the distinct nature of the terms involved.

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Safinaz
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Assuming a Lagrangian proportional to the following terms:

##L \sim ( \partial_\mu \sigma) (\partial^\mu \sigma) - g^{m\bar{n}} g^{r\bar{p}} (\partial_\mu g_{mr} ) ( \partial^\mu g_{\bar{n}\bar{p}} ) ~~~~~ \to (1) ##

Where ##\mu =0,1,2,3,4## and m, n,r, p and ##\bar{n}, \bar{p}, \bar{m}## and ##\bar{r}## = 1,2,3 ( complex coordinates )

Now if I have a complex matrix

##G_{a \bar{b}} \sim g^{m\bar{n}} g^{r\bar{p}} (\partial_a g_{mr} ) ( \partial_{\bar{b}} g_{\bar{n}\bar{p}} ) ~~~~~~~~ \to (2) ##

where ##a, \bar{b}= 1, ..., h_{2,1}##and ##h_{2,1}## is an arbitrary large number.

The question now, can I sub. by ##G_{a \bar{b}}##from equ. (2) into equ. ( 1) ? with the summation on the derivatives has different degrees of freedom? Literally, can I write the Lagrangian as:

##L \sim ( \partial_\mu \sigma) (\partial^\mu \sigma) - G_{a \bar{b}} G^{a \bar{b}} ##?

Any help appreciated!
 
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Maybe I am misunderstanding your notation, but just ##G_{a\bar{b}}G^{a\bar{b}}## written out is not the term you are replacing in the lagrangian (even ignoring the different number of terms that would be summed), so how are you supposing this should work?
 

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