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Timeline for Invariants of exterior powers

Current License: CC BY-SA 3.0

14 events
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Dec 16, 2017 at 4:35 comment added Vanya @Vit Tucek : Thank you for the solution.
Dec 14, 2017 at 16:50 comment added Vít Tuček @AbdelmalekAbdesselam Sorry, I misunderstood your sentence "By the above it has at most that dimension."
Dec 14, 2017 at 16:47 comment added Abdelmalek Abdesselam @VítTuček: I also did not get why you said "However" for $q=14$ when your computations confirm that my upper bound is in fact exact. Indeed, $14=13+1=9+5$ so there are two partitions with distinct parts congruent to 1 mod 4.
Dec 14, 2017 at 16:46 comment added Vít Tuček @AbdelmalekAbdesselam It means the Cartan type. At least that's how they call it in Sage. So it's result for $O(7)$.
Dec 14, 2017 at 16:24 comment added Abdelmalek Abdesselam @VítTuček: thanks for checking +1. Sorry I didn't get what $B_3$ means.
Dec 14, 2017 at 16:20 comment added Vít Tuček Pattern $1,0,0,0,1$ for $q=1,2,3,4,5$ is confirmed on these few cases. However, for $B_3$ I got "Multiplicity of the trivial representation in the 14-th exterior power: 2"
Dec 14, 2017 at 16:17 comment added Abdelmalek Abdesselam @VítTuček: Does your code confirm my predictions for $q=1,\ldots,5$ ?
Dec 14, 2017 at 16:10 history edited Vít Tuček CC BY-SA 3.0
ad cocalc link
Dec 14, 2017 at 15:57 comment added Vít Tuček @user49908 The representation of $O(V)$ on symmetric matrices is not irreducible. The symmetric form defining $O(V)$ is invariant!
Dec 14, 2017 at 14:31 history edited Vít Tuček CC BY-SA 3.0
better wording
Dec 14, 2017 at 14:12 comment added Vanya Thank you I was thinking along similar lines but not beyond the following: By schur's lemma it following that the given object is equal to the $\mathbb{C}$ times multiplicity of trivial representation in $\wedge^k \mathfrak{p}$. Then I thought, "IF" adjoint representation of $\mathbb{k}$ in $\mathfrak{p}$ is irreducible then we get zero for $k =1 $ and by duality for $k= n-1$. I could not proceed further. Thanks for the insight.
Dec 14, 2017 at 13:18 comment added Vít Tuček Sign error. Happens to everybody. :)
Dec 14, 2017 at 13:06 comment added Abdelmalek Abdesselam seems I misread the question the matrices are indeed symmetric instead of antisymmetric.
Dec 14, 2017 at 13:02 history answered Vít Tuček CC BY-SA 3.0