> If you have examples of things like this in other areas like mathematical finance, I'd love to hear about them There are tons of examples in mathematical fin

> If you have examples of things like this in other areas like mathematical finance, I'd love to hear about them There are tons of examples in mathematical finance but the obvious one is the Black/Scholes [1] paper where one of the key assumptions they make (which they know to be untrue but helpful) is that you can replicate a portfolio in continuous time. This allows them to use a constructed portfolio of a risk-free intrest-bearing instrument and the underlying to replicate the price of an option, and the process is a Brownian motion. Everyone knows that actual trading (and thus price processes) are discrete in real markets, but continuous time is much easier to model. Much later on people like Heston and Matytsyn(?sp) came up with stochastic vol models with jumps to replicate discrete price discontinuities, but they're a lot harder to work with in many ways. [1] https://www.cs.princeton.edu/courses/archive/fall09/cos323/papers/black_scholes73.pdf https://www.cs.princeton.edu/courses/archive/fall09/cos323/p...