I was implementing an algorithm mentioned in a paper(DOI:10.1109/TVT.2022.3229888). In the iterating process, inverse laplacian operator involved when updating phi(t,x).
ϕ^(k+1) (t,x)=ϕ^k (t,x)+σ(-Δ)^(-1) (-∂_t ρ ̄^(k+1) (t,x)+∇⋅m ̄^(k+1) (t,x)) the inverse laplace operator term is (-Δ)^(-1)
how to code inverse laplacian operator? the paper mentioned the 'Discretization Form' so I used the discret laplace operator and then get the inverse matrix. but this method seems incorrect?