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Oct 25, 2023 at 7:37 comment added Wolfgang What about the further generalization $\mathbb{E}[{\rm det}(\sum_i X_i^2+k\sum_{i\ne j} X_i X_j)]$ for a given $k\in \mathbb{R}$? (and would it be different from $\mathbb{E}[{\rm det}(\sum_i X_i^2+2k\sum_{i<j} X_i X_j)]$?)
Oct 19, 2023 at 16:02 history edited Abdelmalek Abdesselam CC BY-SA 4.0
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Oct 19, 2023 at 15:45 comment added Abdelmalek Abdesselam @TheSimpliFire: The beginning and the end of the apply. The computation of the contribution of $\omega$ is also the sign of that permutation. But one would also get isolated/disconnected loops contributing a factor of $n$ each. The part which would likely be too complicated is counting the analogues of the permutations $\sigma_i$ which would become much more complicated combinatorial objects. Follwing up on Richard's comment, one could start by looking up the article by Beck arxiv.org/abs/2207.09311
Oct 19, 2023 at 13:21 comment added Richard Stanley There is a nice generating function for $\mathbb{E}\det X^4$ so maybe this can be extended to $\mathbb{E}\det \sum X_i^4$. For $\mathbb{E}\det X^6$ see arXiv:2206.11356. It looks like $\mathbb{E} \det X^8$ will be very complicated.
Oct 19, 2023 at 10:40 comment added TheSimpliFire Can this method be used to compute $\Bbb E\det\sum X_i^k$ for integer $k>2$?
Oct 18, 2023 at 23:40 history edited Abdelmalek Abdesselam CC BY-SA 4.0
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Oct 18, 2023 at 23:25 comment added Abdelmalek Abdesselam Most relevant in Cvitanovic's book are equations (6.38) and (6.46).
Oct 18, 2023 at 23:21 comment added Abdelmalek Abdesselam See, e.g., the book by Cvitanovic birdtracks.eu/version9.0/GroupTheory.pdf If you have never seen this, you have to practice a bit.
Oct 18, 2023 at 22:10 comment added mathworker21 Can someone explain to me what on Earth is going on in this answer? Any references appreciated.
Oct 18, 2023 at 21:21 history edited Abdelmalek Abdesselam CC BY-SA 4.0
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Oct 18, 2023 at 20:45 history edited Abdelmalek Abdesselam CC BY-SA 4.0
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Oct 18, 2023 at 20:34 history edited Abdelmalek Abdesselam CC BY-SA 4.0
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Oct 18, 2023 at 20:29 history answered Abdelmalek Abdesselam CC BY-SA 4.0