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Chirality, genera and simplicity of orientably-regular maps

author: Marston Conder, University of Auckland

Description

An orientably-regular map is a cellular embedding of a graph or multigraph in an orientable-surface, with the property that the group of orientation- and incidencepreserving automorphisms has a single orbit on the arcs (ordered edges) of the embedding. I will describe a recent computer-assisted determination of all such maps on surfaces of genus 2 to 100, which revealed some interesting patterns, leading to new discoveries about gaps in the genus spectrum of examples that (a) are chiral, and/or (b) have the property that the map or its topological dual has simple underlying graph. The last part is joint work with Jozef Siran and Tom Tucker.

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Slides
0:00 - Chirality, genera and simplicity of orientably-regular maps - Announcement
1:58 Chirality, genera and simplicity of orientably-regular maps
3:47 Regular maps - General
7:08 Some history
9:09 Classification of regular maps
10:24 Regular maps - Page 1
13:02 Regular maps - Page 2
16:09 Conversely ...
16:26 - Regular maps - Page 2 - Part 2
16:51 - Conversely ... - Part 2
18:28 Genus calculations
19:41 Questions about the genus spectrum
23:22 Chirality - Page 1
25:00 Chirality - Page 2
26:20 Simplicity
28:08 Low index normal subgroups
31:55 Determination of regular maps of small genus
32:59 Digression: Symmetric cubic graphs
34:03 Summary of maps data for small genus
35:19 Observations
37:56 Theorems
41:00 In fact, even more ...
43:05 Coprime classification - Page 1
43:39 Coprime classification - Page 2
45:03 Cases where X intersect Y is trivial
45:33 Cases where X intersect Y is non-trivial
46:37 Table - Comments
47:31 Approach when −X = p or 2p for p prime
48:45 Summary: new theorems
48:58 How prevalent is chirality?
49:28 Another viewpoint ....
50:35 Further consequence for chirality?
52:13 Abstract - Questions
52:28 - Further consequence for chirality? - Questions

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