Hi guys, probably that's the wrong forum, but I was just curious about the plot (Figure 1 Chapter XI A./1. page 1097 / Volume II) of the eigenvalues [tex]E(\lambda)[/tex]. If I calculate them they are supposed to be straight lines with positive or negative slope i.e.: [tex]E(\lambda) = E_n^0 + \lambda \epsilon_1^j[/tex] in first order perturbation theory. Am I missing s.th. or are these curves just ment to be realistic measurement curves (and if so why isn't there any hint in the text) ?