Timeline for Equivariant Riemann-Hurwitz
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 20, 2017 at 14:18 | vote | accept | Ben Wieland | ||
| Jun 18, 2017 at 20:54 | answer | added | Niels | timeline score: 6 | |
| Jun 18, 2017 at 19:55 | comment | added | David Lehavi | I know a topological / combinatorial way to compute examples - maybe you can push it a little further: remove all the branch points from $Y$, and all their pullbacks from $X$, giving you a Galois covering map $X'\to Y'$. Note that 1. both $X', Y'$ retract to bouquets of circles, 2. the map $\pi_1(X')\to\pi_1(Y')$ is a finite map of free groups, 3. the map $\pi_1(Y')\to\pi_1(Y)$ is killing generators, and 4. the map $\pi_1(X')\to\pi_1(X)$ is either killing generators or powers of them. I.e. on the level of fundamental groups it's all completely explicit. | |
| Jun 18, 2017 at 14:44 | history | asked | Ben Wieland | CC BY-SA 3.0 |