+1 vote
asked by (180 points)


Is it possible to reverse only certain arrows of an IQTensor without subclassing or similar tricks?

I can't do something like

because this reverses all arrow directions.

I made a sketch of the relevant case:

Best regards and thank you.

1 Answer

+1 vote
answered by (70.1k points)

Hi, I see what you are asking and the sketch that you linked, but could you give me a little more background on why you want to do it? After thinking about it a bit, flipping the arrows is associate with complex conjugation, yet there's no way to "partially" conjugate elements of a tensor.

On the other hand, individual IQIndex arrows could in principle be reversed if the data in the IQTensor was moved into a different pattern of quantum number blocks. But this might be involved to implement so I'd like to better understand the use case.


commented by (180 points)

I've just discovered that I understood the arrows wrong and that I don't need this kind of operation.
I'm currently working on an implementation for TDVP (http://arxiv.org/abs/1408.5056) in ITensor.
I thought that I need the "Arrow inversion" for the application of the effective Hamiltonian on a Tensor.

Nevertheless, thank you very much for your answer!

Best regards,
commented by (70.1k points)
Hi Florian,
Ok glad you figured it out!
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