Lecture22 Tue 2024 11 21 Fractals (Transversal structure of Rossler/Lorenz) % =============================================================================== DIMENSION Additional info in: "Lecture21_2021_scan.pdf" and "Lecture21_whiteboard353.pdf" posted with Lecture21 Question: How do we characterize fractals? Want some measure that allows a characterization of fractals; similar to the way "genus" characterizes surfaces [surfaces with the same genus are equivalent topologically] ... Dimension was born from this purpose, though it failed to achieve this objective. In this stuff I will be following "Lecture21_2021_scan.pdf" and "Lecture21_whiteboard353.pdf" Self-similar dimension [definition, motivation, examples]. Topological Cantor set. Box dimension. Problem: Box(rationals in [0 1]) = 1. Hausdorf dimension. Pointwise and correlation dimensions. Mention multifractals [see the end of chapter 11 in Strogatz]. Liapunov Takens' embedding theorem. "Fun" stuff: dimension of music composers. % % ----------------------------------------------------------------------------- % % START WITH 1-D MAPS x_{n+1} = f(x_n); Linear stability. COBWEBS Illustrate it with f(x) = r x (1-x); r < 1 [x = 0 is a global attractor]. % % =============================================================================== EOF