Triangular C${}^{\ast }$-bialgebra defined as the direct sum of matrix algebras

Katsunori Kawamura

Let $M_{\ast }(\mathbf{C})$ denote the C${}^{\ast }$-algebra defined as the direct sum of all matrix algebras $\{M_n(\mathbf{C}):n\ge 1\}$. It is known that $M_{\ast }(\mathbf{C})$ has a non-cocommuta…