A universal differential equation
Article by Lee A. Rubel
In collections: Fun maths facts, Unusual computers
There exists a non trivial fourth-order algebraic differential equation $P(y',y'',y''',y'''') = 0,$ where $$P$$ is a polynomial in four variables, with integer coefficients, such that for any continuous function $$\phi$$ on $$(-\infty,\infty)$$ and for any positive continuous function $$\varepsilon(t)$$ on...
URL: projecteuclid.org/euclid.bams/