On Poincaré and de Rham‘s theorems

Abstract

We prove Poincaré's theorem under general assumptions on the data. Then we derive the regularity of the solution from a result of Borchers and Sohr [6]. Finally, we give an elementary proof of the de Rham's theorem in the case of 1-dimensional flows on the Euclidean space by applying the techniques introduced in the proof of Poincaré's theorem.