A note on generalized Poincar\'e-type inequalities with applications to weighted improved Poincar\'e-type inequalities

The main result of this paper supports a conjecture by C. P'erez and E. Rela about a very recent result of theirs on self-improving theory. Also, we extend the conclusions of their theorem to the range $p<1$. As an application of our result, we give a unified vision of weighted improved Poincar'e-type inequalities in the Euclidean setting, which gathers both weighted improved classical and fractional Poincar'e inequalities within an approach which avoids any representation formula. We improve some already known results. Finally, we also explore analog inequalities in the context of metric spaces by means of the already known self-improving results.