- Commit
- 57b0e116ab371ed24a2b557766df9736a2ba0809
- Parent
- 20b339fbb44ee00e3ae06daa588ae05e5e32df72
- Author
- Pablo <pablo-pie@riseup.net>
- Date
Improved a remark
Add comments on the proofs of linearity of Mod(Σ_2) by Korkmaz and Bigelow-Budney
My M2 Memoire on mapping class groups & their representations
Improved a remark
Add comments on the proofs of linearity of Mod(Σ_2) by Korkmaz and Bigelow-Budney
2 files changed, 32 insertions, 9 deletions
Status | File Name | N° Changes | Insertions | Deletions |
Modified | references.bib | 23 | 23 | 0 |
Modified | sections/introduction.tex | 18 | 9 | 9 |
diff --git a/references.bib b/references.bib @@ -188,6 +188,29 @@ pages = {3097--3132} } +@article{bigelow-budney, + author = {Bigelow, Stephen and Budney, Ryan}, + doi = {10.2140/agt.2001.1.699}, + issn = {1472-2747}, + journal = {Algebraic \& Geometric Topology}, + month = nov, + number = 2, + pages = {699--708}, + title = {The mapping class group of a genus two surface is linear}, + volume = {1}, + year = {2001}, +} + +@article{korkmaz-linearity, + author = {Mustafa Korkmaz}, + journal = {Turkish Journal of Mathematics}, + pages = {367--371}, + title = {On the Linearity of Certain Mapping Class Groups}, + url = {https://journals.tubitak.gov.tr/math/vol24/iss4/5/}, + volume = {24}, + year = {2000}, +} + @book{kerekjarto, author = {Kerékjártó, Béla}, doi = {10.1007/978-3-642-50825-7},
diff --git a/sections/introduction.tex b/sections/introduction.tex @@ -10,7 +10,7 @@ mid-nineteenth century and is often attributed to Möbius, but at that time it was not yet known that all closed surfaces admit a triangulation. Radò \cite{rado} would go on to establish this fact in 1925.}, Kerékjártó and others \cite{rado, kerekjarto}. We refer the reader to \cite{thomassen} for a complete -proof. +proof. \begin{theorem}[Classification of surfaces]\label{thm:classification-of-surfaces} Any closed connected orientable surface is homeomorphic to the connected sum @@ -372,18 +372,18 @@ examples of mapping class groups, namely that of the torus \(\mathbb{T}^2 = \operatorname{SL}_2(\mathbb{Z})\). \end{example} -% TODO: Add comments on the proof of linearity of Mod(S_2) by Korkmaz and -% Bigelow-Budney? \begin{remark} Despite the fact \(\psi : \Mod(\mathbb{T}^2) \to \operatorname{SL}_2(\mathbb{Z})\) is an isomorphism, the symplectic representation is \emph{not} injective for surfaces of genus \(g \ge 2\) -- - see \cite[Section~6.5]{farb-margalit} for a description of its kernel. In - fact, the question of existence of injective linear representations of - \(\Mod(\Sigma_g)\) remains wide-open. Recently, Korkmaz - \cite[Theorem~3]{korkmaz} established the lower bound of \(3 g - 3\) for the - dimension of an injective representation of \(\Mod(\Sigma_g)\) in the \(g \ge - 3\) case -- if one such representation exists. + see \cite[Section~6.5]{farb-margalit} for a description of its kernel. + Korkmaz and Bigelow-Budney \cite{korkmaz-linearity, bigelow-budney} showed + there exists injective linear representations of \(\Mod(\Sigma_2)\), but the + question of linearity of \(\Mod(\Sigma_g)\) remains wide-open for \(g \ge + 3\). Recently, Korkmaz \cite[Theorem~3]{korkmaz} established the lower bound + of \(3 g - 3\) for the dimension of an injective representation of + \(\Mod(\Sigma_g)\) in the \(g \ge 3\) case -- if one such representation + exists. \end{remark} Another fundamental class of examples of representations are the so called