Erratum: “Reciprocity Theorems for Diffusion, Flow, and Waves” [Journal of Applied Mechanics, 2004, 71(1), pp. 145–150]

Matrix C defined in Appendices C and D is singular and hence xpressions containing the inverse of C cannot be used as such. he singularity is a consequence of the chosen organization of the atrix-vector differential equation in these appendices. The field ector u contains nine stress components of which only six are ndependent. By removing the three redundant stress components rom u and reorganizing the matrix-vector equation accordingly, e obtain a matrix C that is invertible. The redefined matrices =C−1A and B=C−1B in Appendices C and D obey symmetry elations 9 and 13 in the body of the paper. Hence, the unified eciprocity theorems 12 and 14 are valid for the modified atrix-vector differential equation in these appendices. Explicit