Connectivity of the real locus
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Yasmina Atarihuana |
Universidad de La Frontera (Chile) |
Abstract: |
The moduli space \[{\mathcal M}_{0,[n+1]}\] of isomorphisms classes of \[(n+1)\] -marked spheres, where \[n\geq 3\] , is a complex orbifold of dimension \[n-2\] . Its admits a natural real structure, this induced by complex conjugation on the Riemann sphere. The locus \[{\mathcal B}_{0,[n+1]}({\mathbb R})\] of its fixed points consists of the isomorphism classes of those marked spheres admitting an anticonformal automorphism. Inside this locus is the real locus \[{\mathcal B}_{0,[n+1]}^{\mathbb R}\] , consisting of those classes of marked spheres admitting an anticonformal involution. We prove that \[{\mathcal B}_{0,[n+1]}^{\mathbb R}\] is connected for \[n\geq 5\] odd. It is disconnected for \[n=2r\] , where \[r\geq 5\] is odd. The connectivity of \[{\mathcal B}_{0,[n+1]}^{\mathbb R}\] is described by the intersection graph \[{\mathcal G}_{n}\] of \[{\mathcal B}_{0,[n+1]}^{\mathbb R}\] , whose vertices represent the irreducible components of the real locus and the edges their intersection. |
This is part of the results obtained for my Ph. D. Thesis under the supervision of R. A. Hidalgo and S. Quispe. |