Rational cohomology of the moduli space of genus 4 curves
arXiv:math/0312055
Abstract
We prove that the Poincare' polynomial of the moduli space of smooth genus 4 curves is 1+t^2+t^4+t^5. We show this by producing a stratification of the space, such that all strata are geometric quotients of complements of discriminants.
26 pages