Formula for Entropy Solutions of the 1D Pressureless Euler–Poisson System: Well-Posedness of Entropy Solutions and the Asymptotic Behavior
摘要
We consider the Cauchy problem for the one-dimensional pressureless Euler–Poisson system, which describes dust stars with density being a finite Radon measure. For this Cauchy problem, we introduce three generalized potentials to establish a representation formula for entropy solutions, and prove the uniqueness of entropy solutions via the variational principle and the method of generalized characteristics. Furthermore, we employ this newly derived formula to analyze the asymptotic behavior of entropy solutions: For the initial data