TLDR: The "most addictive theorem" is the Hartman–Grobman theorem which states that under some very specific and technical conditions non-linear system near equ

TLDR: The "most addictive theorem" is the Hartman–Grobman theorem which states that under some very specific and technical conditions non-linear system near equilibrium can be described with a linear system. More at Wikipedia: https://en.wikipedia.org/wiki/Hartman–Grobman_theorem https://en.wikipedia.org/wiki/Hartman–Grobman_theorem