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Timeline for Characters on $PGL(2)$

Current License: CC BY-SA 3.0

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Feb 28, 2018 at 21:06 comment added LSpice In general one replaces the notion of conductor by the notion of depth (for which see the papers of Moy and Prasad), and the depth of $\chi \circ \det$ is $r - 1$ in the situation you describe. (I am assuming that $p \ne 2$.)
Feb 28, 2018 at 21:05 comment added LSpice It is not quite clear what "the conductor of $\chi \circ \det$" should mean a priori (hence how to compare it to the conductor of $\chi$), since $\mathrm{PGL}(2, F)$ carries multiple natural filtrations, unlike $F^\times = \mathrm{GL}(1, F)$ which carries only a single natural filtration. One possible definition would be just to define the conductor of $\chi \circ \det$ to be that of $\chi$.
Feb 28, 2018 at 21:02 comment added LSpice Since $\mathrm{SL}(2, F)$ is generated by its unipotents, any character of $\mathrm{PGL}(2, F)$ is trivial on the image of $\mathrm{SL}(2, F)$. Since $\mathrm{PGL}(2, F)/\mathrm{SL}(2, F)$ is isomorphic to $F^\times/(F^\times)^2$ via the determinant, indeed the characters of $\mathrm{PGL}(2, F)$ are as you describe.
Feb 28, 2018 at 21:01 comment added LSpice I think also "a group such that $F^2(1 + p^r\mathscr O_p)$" is meant to be "a group such as $(F^\times)^2(1 + p^r\mathscr O_p)$".
Feb 27, 2018 at 21:30 comment added D_S Somewhat related: mathoverflow.net/questions/292424/…
Feb 27, 2018 at 18:39 comment added Qfwfq Ah okay, I suspected that, but.. who knows! :)
Feb 27, 2018 at 16:47 comment added Desiderius Severus @Qfwfq That I made a typo, now corrected :)
Feb 27, 2018 at 16:47 history edited Desiderius Severus CC BY-SA 3.0
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Feb 27, 2018 at 16:47 comment added Qfwfq I'm curious about the notation $PGL(é)$: what does it mean?
Feb 27, 2018 at 16:31 history asked Desiderius Severus CC BY-SA 3.0