DISTANCE SPECTRA OF H-JOIN GRAPHS

A distance spectrum of a graph is a set of eigenvalues of its distance matrix. A distance energy, which is a useful molecular descriptor in QSPR modelling, is the sum of absolute values of distance eigenvalues. In the paper, we consider H-join on graphs, where H is an arbitrary graph. In terms of distance matrix, we determine the D-spectra of graphs obtained by this operation on distance regular graphs of diameter at most 2. Some additional consequences on D-spectral radius, D-integral graphs, D-cospectral graphs, D-equienergetic graphs, etc. are also obtained.