The cohomology ring of the real locus of the moduli space of stable curves of genus 0 with marked points

  title={The cohomology ring of the real locus of the moduli space of stable curves of genus 0 with marked points},
  author={Pavel Etingof and Andr{\'e} Henriques and Joel Kamnitzer and Eric M. Rains},
  journal={Annals of Mathematics},
We compute the Poincare polynomial and the cohomology algebra with rational coefficients of the manifold M_n of real points of the moduli space of algebraic curves of genus 0 with n labeled points. This cohomology is a quadratic algebra, and we conjecture that it is Koszul. We also compute the 2-local torsion in the cohomology of M_n. As was shown by the fourth author, the cohomology of M_n does not have odd torsion, so that the above determines the additive structure of the integral homology… 

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