On reduced amalgamated free products of C*-algebras and the MF property Jonas Seebach 22D2546L09C*-algebragrouprepresentationextension We establish the MF property of the reduced group $C^{*}$-algebra of an amalgamated free product of countable abelian discrete groups. This result is then used to give a characterization of the amalgamated free products of abelian groups for which the BDF semigroup of the reduced group $C^{*}$-algebra is a group. Along the way we get a tensor product factorization of the corresponding group von Neumann algebra. We end the exposition by applying the ideas from the first part to give a few more examples of groups with a reduced group $C^{*}$-algebra which is MF. Indiana University Mathematics Journal 2012 text pdf 10.1512/iumj.2012.61.4695 10.1512/iumj.2012.61.4695 en Indiana Univ. Math. J. 61 (2012) 1911 - 1923 state-of-the-art mathematics http://iumj.org/access/