# Sharp estimates for periodic solutions to the Euler–Poisson–Darboux equation

### Paulo Amorim

Universidade de Lisboa, Portugal### Philippe G. LeFloch

Université Pierre et Marie Curie - Paris 6, France

## Abstract

We establish sharp estimates for distributional solutions to the Euler–Poisson–Darboux equation posed in a periodic domain. These equations are highly singular, and setting the Cauchy problem requires a precise understanding of the nature of the singularities that may arise in weak solutions. We consider initial data in a space of functions with fractional derivatives such that weak solutions are solely integrable, and we derive sharp continuous dependence estimates for solutions to the initial-value problem. Our results strongly depend on a key parameter arising in the Euler–Poisson–Darboux equation.

## Cite this article

Paulo Amorim, Philippe G. LeFloch, Sharp estimates for periodic solutions to the Euler–Poisson–Darboux equation. Port. Math. 65 (2008), no. 3, pp. 387–429

DOI 10.4171/PM/1819