Category:Named Theorems/du Bois-Reymond

This category contains results named for Paul David Gustav du Bois-Reymond‎.

German mathematician who worked on the mechanical equilibrium of fluids, the theory of functions and in mathematical physics.

Also worked on Sturm–Liouville theory, integral equations, variational calculus, and Fourier series.

In $1873$, constructed a continuous function whose Fourier series is not convergent.

His lemma defines a sufficient condition to guarantee that a function vanishes almost everywhere.

Also established that a trigonometric series that converges to a continuous function at every point is the Fourier series of this function.

Discovered a proof method that later became known as the Cantor's diagonal argument.

His name is also associated with the Fundamental Lemma of Calculus of Variations, of which he proved a refined version based on that of Lagrange.