Maths economists use:
>dynamic systems
>game theory
>differential equations
>various forms of optimization
>convex analysis
>fixed point theory
>stochastic calculus and differential equations
>statistics and econometrics

Maths physicists use:
>differential equations
>functional analysis of unbounded operators
>semi-Riemannian geometry
>Dirac operators and spinors
>Lie algebras and representation theory
>symplectic and contact geometry
>Calabi-Yau manifolds
>algebraic topology

Why do economists use exactly the math you'd expect them to use, while physicists essentially operate on random shit? What's the scientific reason for this phenomenom?