Reciprocal Distance Spectral Polynomial for Join of Two Graphs

Reciprocal distance matrix (Harary matrix) of a connected graph $G$ is $RD(G)=[\frac{1}{d_{ij}}]$ with $d_{ij}$ as distance between vertices $v_i$ and $v_j$. $RD$-spectral polynomial has been studied for join of two regular graphs when both of them are of diameter $\leq2$. Present work focus on the study of $RD$-spectral polynomial for join of any two graphs using the coronal concept.