GitLab

Since t_0 = log(k_1), where k_1 is the first mode in the corresponding harmonic
space. k_1 can be smaller than one and therefore t_0 can be any real number.

Does not depend on zero mode anymore which is not plotted anyways

This is a performance tweak. Since inverse diagonal operators are automatically
converted to a pure diagonal operator with the inverse on its diagonal, this
commit saves memory.