Timeline for Hurwitz Encoding
Current License: CC BY-SA 2.5
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 14, 2010 at 17:53 | comment | added | David E Speyer | To elaborate my above answer further: a degree n cover always gives a map from pi_1(U) to S_n. Assuming connectivity for simplicity, the cover is regular if the stabilizer of 1 (in \{1,2,...,n\}) is normal. | |
| Jan 14, 2010 at 17:48 | comment | added | David E Speyer | By regular, you mean the same thing as wikipedia? en.wikipedia.org/wiki/… If so, no. Take P^1, remove three points, and let the fundamental group act on a three element set by (12), (13) and (23). This corresponds to a non-regular cover. | |
| Jan 14, 2010 at 16:56 | comment | added | Mariano Suárez-Álvarez | Shouldn't one rather say that "degree n regular connected covers of U are classified by transitive actions of $\pi_1(U)$ on an n-element set"? | |
| Jan 14, 2010 at 15:55 | history | edited | David E Speyer | CC BY-SA 2.5 |
corrected typos
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| Dec 20, 2009 at 18:53 | vote | accept | john mangual | ||
| Dec 20, 2009 at 15:14 | history | answered | David E Speyer | CC BY-SA 2.5 |