Timeline for Perturbation theory compact operator
Current License: CC BY-SA 4.0
3 events
| when toggle format | what | by | license | comment | |
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| Mar 5, 2019 at 10:40 | comment | added | Mateusz Kwaśnicki | If $\alpha_j$ are the coefficients in the eigenvector expansion of $x$, then $\sum |\alpha_j|^2 = 1$ and $\sum |\alpha_j|^2 |\lambda_j - \lambda|^2 \leqslant \varepsilon^2$. That's all one can say, and of course this implies that, for example, $\sum_{j : |\lambda_j - \lambda| > k \varepsilon} |\alpha_j|^2 \leqslant 1/k^2$. | |
| Mar 4, 2019 at 21:45 | review | First posts | |||
| Mar 4, 2019 at 22:10 | |||||
| Mar 4, 2019 at 21:40 | history | asked | user136577 | CC BY-SA 4.0 |