Spectral Projector-Based Graph Fourier Transforms

The paper presents the graph Fourier transform (GFT) of a signal in terms of its spectral decomposition over the Jordan subspaces of the graph adjacency matrix A This representation is unique and coordinate free, and it leads to unambiguous definition of the spectral components ("harmonics") of a graph signal. This is particularly meaningful when Ahas repeated eigenvalues, and it is very useful when Ais defective or not diagonalizable...