Timeline for Group of matrices in which every matrix is similar to unitary
Current License: CC BY-SA 4.0
18 events
| when toggle format | what | by | license | comment | |
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| S May 26, 2023 at 5:59 | vote | accept | Александр Худяков | ||
| May 26, 2023 at 3:14 | history | became hot network question | |||
| S May 26, 2023 at 3:09 | vote | accept | Александр Худяков | ||
| S May 26, 2023 at 5:59 | |||||
| S May 26, 2023 at 3:09 | vote | accept | Александр Худяков | ||
| S May 26, 2023 at 3:09 | |||||
| May 26, 2023 at 1:11 | history | edited | LSpice | CC BY-SA 4.0 |
Tidying
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| May 26, 2023 at 0:18 | answer | added | Moishe Kohan | timeline score: 16 | |
| May 25, 2023 at 21:58 | answer | added | Geoff Robinson | timeline score: 7 | |
| May 25, 2023 at 21:31 | vote | accept | Александр Худяков | ||
| S May 26, 2023 at 3:09 | |||||
| May 25, 2023 at 21:25 | comment | added | YCor | The conclusion is negative as [Dave Benson's answer] shows. However, I think it can be shown that one can block-triangulate so that diagonal blocks are unitary. In particular, the conclusion is positive in the irreducible case. | |
| May 25, 2023 at 21:21 | history | edited | YCor | CC BY-SA 4.0 |
formatting
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| May 25, 2023 at 20:25 | vote | accept | Александр Худяков | ||
| May 25, 2023 at 20:27 | |||||
| May 25, 2023 at 20:18 | comment | added | Александр Худяков | Fedor Petrov, thank you for noting this! The hard part is to prove that the operators are bounded. | |
| May 25, 2023 at 20:14 | history | edited | Александр Худяков | CC BY-SA 4.0 |
edited body
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| May 25, 2023 at 20:12 | comment | added | Fedor Petrov | If all operators in $G$ are uniformly bounded, then $G$ preserves the norm $\|x\|:=\sup_{g\in G} |gx|$ (where $|x|$ is some fixed norm). Thus it preserves the John ellipsoid of the unit ball of $\|\cdot\|$, that yields affirmative answer. | |
| May 25, 2023 at 20:08 | answer | added | Dave Benson | timeline score: 14 | |
| May 25, 2023 at 19:26 | history | edited | Александр Худяков | CC BY-SA 4.0 |
deleted 3 characters in body
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| S May 25, 2023 at 19:07 | review | First questions | |||
| May 25, 2023 at 19:16 | |||||
| S May 25, 2023 at 19:07 | history | asked | Александр Худяков | CC BY-SA 4.0 |