Exotic finite functorial semi-norms on singular homology
  Functorial semi-norms on singular homology give refined "size" information on singular homology classes. A fundamental example is the l^1-semi-norm. We show that there exist finite functorial semi-norms on singular homology that are exotic in the sense that they are not carried by the l^1-semi-norm. 
Daniel Fauser, Clara Loeh
math.GT