Weak stability of Lagrangian solutions to the semigeostrophic equations
arXiv:0901.3890 · doi:10.1088/0951-7715/22/10/011
Abstract
In [1], Cullen and Feldman proved existence of Lagrangian solutions for the semigeostrophic system in physical variables with initial potential vorticity in , . Here, we show that a subsequence of the Lagrangian solutions corresponding to a strongly convergent sequence of initial potential vorticities in converges strongly in , , to a Lagrangian solution, in particular extending the existence result of Cullen and Feldman to the case . We also present a counterexample for Lagrangian solutions corresponding to a sequence of initial potential vorticities converging in . The analytical tools used include techniques from optimal transportation, Ambrosio's results on transport by vector fields, and Orlicz spaces. [1] M. Cullen and M. Feldman, {\it Lagrangian solutions of semigeostrophic equations in physical space.} SIAM J. Math. Anal., {\bf 37} (2006), 1371--1395.
arXiv comment19 pages