BIRS Workshop Lecture Videos

Banff International Research Station Logo

BIRS Workshop Lecture Videos

Amalgamated Products of Strongly RFD $\mathrm{C}^*$-algebras arising from locally compact groups Courtney, Kristin


Residual finite dimensionality is the $\mathrm{C}^*$-algebraic analogue for maximal almost periodicity and residual finiteness for groups. Just as with the analogous group-theoretic properties, there is significant interest in when residual finite dimensionality is preserved under standard constructions, in particular amalgamated free products. In general, this question is quite difficult; however the answer is known when the amalgam is finite dimensional or when the two $\mathrm{C}^*$-algebras are commutative. In moving beyond these cases, group theoretic restrictions suggest that we consider central amalgams. We generalize the commutative case to pairs of so-called ``strongly residually finite dimensional" $\mathrm{C}^*$-algebras amalgamated over a central subalgebra. Examples of strongly residually finite dimensional $\mathrm{C}^*$-algebras include group $\mathrm{C}^*$-algebras associated to virtually abelian groups, certain just-infinite groups, and Lie groups with only finite dimensional irreducible unitary representations. Though this property may seem restrictive, a recent result of Thom indicates that it is in fact necessary. This is joint work with Tatiana Shulman.

Item Media

Item Citations and Data


Attribution-NonCommercial-NoDerivatives 4.0 International