Let \(\Sigma \) be an oriented genus 2 surface smoothly embedded in \(\mathbb {R}^3\).
- Describe the Gauss map \(g:\Sigma \to S^2\) and define the Gaussian curvature at a point of \(\Sigma \) in terms of \(g\).
- State the Gauss-Bonnet theorem for this situation.
- Prove that \(\Sigma \) has (many) saddle points, i.e. points of negative curvature.