add biharmonic solver
Add a biharmonic solver in the FFTPoissonSolver class, which is the same as the Vico-Greengard function with another Green's function (given in the paper). This is required for the Langevin collisional model project.
Code indexing in gitaly is broken and leads to code not being visible to the user. We work on the issue with highest priority.
Add a biharmonic solver in the FFTPoissonSolver class, which is the same as the Vico-Greengard function with another Green's function (given in the paper). This is required for the Langevin collisional model project.