Graph homology of moduli space of pointed real curves of genus zero

Abstract

The moduli space $\bar{M}_S^\sigma(R)$ parameterizes the isomorphism classes of $S$-pointed stable real curves of genus zero which are invariant under relabeling by the involution $\sigma$. This moduli space is stratified according to the degeneration types of $\sigma$-invariant curves. The degeneration types of $\sigma$-invariant curves are encoded by their dual trees with additional decorations. We construct a combinatorial graph complex generated by the fundamental classes of strata of $\bar{M}_S^\sigma(R)$. We show that the homology of $\bar{M}_S^\sigma(R)$ is isomorphic to the homology of our graph complex. We also give a presentation of the fundamental group of $\bar{M}_S^\sigma(R)$.