Singular value functions for C${}^{\ast }$-algebras

We introduce $\mathit{\text{singular}}\mathit{\text{value}}\mathit{\text{functions}}$ for C${}^{\ast }$-algebras, generalizing the singular values of compact operators on Hilbert spaces. We also establish several fundamental properties of these singular value functions and present examples of singular value functions for certain classes of C${}^{\ast }$-algebras.