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Neeraj K. Dhanwani,
Kashyap Rajeevsarathy, and
Apeksha Sanghi
Split metacyclic actions on surfaces
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Published: |
March 23, 2022. |
Keywords: |
surface; mapping class; finite order maps; metacyclic subgroups. |
Subject: |
Primary 57K20; Secondary 57M60. |
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Abstract
Let Mod(Sg) be the mapping class group of the closed orientable surface Sg of genus
g ≥ 2. In this paper, we derive necessary and sufficient conditions under which two torsion elements in
Mod(Sg) will have conjugates that generate a non-abelian finite split metacyclic subgroup of
Mod(Sg). As applications of the main result, we give a complete characterization of the finite dihedral and the generalized quaternionic subgroups of Mod(Sg) up to a certain equivalence that we will call weak conjugacy. Furthermore, we show that any finite-order mapping class whose corresponding orbifold is a sphere has a conjugate that lifts under certain finite-sheeted regular cyclic covers of Sg. Moreover, for g ≥ 5, we show the existence of an infinite dihedral subgroup of Mod(Sg) that is generated by an involution and a root of a bounding pair map of degree 3. Finally, we provide a complete classification of the weak conjugacy classes of the non-abelian finite split metacyclic subgroups of Mod(S3) and Mod(S5). We also describe nontrivial geometric realizations of some of these actions.
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Acknowledgements
The first and third authors were supported by the UGC-JRF fellowship. The authors would also like to thank Dr. Siddhartha Sarkar for helpful discussions.
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Author information
Neeraj K. Dhanwani:
Department of Mathematics
Indian Institute of Science Education and Research Mohali
Knowledge city, Sector 81, Manauli, PO, Sahibzada Ajit Singh Nagar
Mohali 140306, Punjab, India
neerajk.dhanwani@gmail.com
Kashyap Rajeevsarathy:
Department of Mathematics
Indian Institute of Science Education and Research Bhopal
Bhopal Bypass Road, Bhauri
Bhopal 462 066, Madhya Pradesh, India
kashyap@iiserb.ac.in
Apeksha Sanghi:
Department of Mathematics
Indian Institute of Science Education and Research Bhopal
Bhopal Bypass Road, Bhauri
Bhopal 462 066, Madhya Pradesh, India
apeksha16@iiserb.ac.in
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