Magnus Landstad: Exotic group algebras and their (co)actions

Given a locally compact group G, the full C*-algebra C*(G) and reduced C*-algebra C*_r(G)  are well known. But already Eymard in his fundamental paper in 1964 realized that there are a lot of algebras in between.
 
Until recently these “exotic” C*-algebras in between has received little attention. I will try to give a survey of these algebras and explain how they give rise to exotic crossed products and exotic coactions.
 
However, we have more questions than answers.