Numerical approximations to extremal toric K\"ahler metrics with arbitrary K\"ahler class

We develop new algorithms for approximating extremal toric K"ahler metrics. We focus on an extremal metric on ${\mathbb{C}\mathbb{P}}^2\mathrm{♯}2{\overline{\mathbb{C}\mathbb{P}}}^2$, which is conformal to an Einstein metric (the Chen-LeBrun-Weber metric). We compare our approximation to one given by Bunch and Donaldson and compute various geometric quantities. In particular, we demonstrate a small eigenvalue of the scalar Laplacian of the Einstein metric which gives a numerical evidence that the Einstein metric is conformally unstable under the Ricci flow.