title: Norm statement considered harmful: comment on 'evolution of unconditional dispersal in periodic environments'.
abstract: The mathematical symbol for the norm, which is heavily overloaded with multiple definitions that have both universal and specific properties, lends itself to confusion. This is manifest in the proof of an important theorem for population dynamics by Schreiber and Li on how dispersal increases population growth in a periodic environment. Here the theorem is placed in context, the proof is clarified, and the confusing but inconsequential errors corrected.
authors.affiliation: a The Konrad Lorenz Institute for Evolution and Cognition Research , Klosterneuburg , Austria.
authors.forename: Lee
authors.initials: L
authors.lastname: Altenberg
mesh_terms: D005075:Biological Evolution; D008962:Models, Theoretical; D011157:Population Dynamics
keywords: 15A18; 15A60; 15B51; 47A55; 92D15; Perron root; Reduction principle; evolution of dispersal; induced norm; modifier theory; operator norm; spectral radius