ABSTRACT
Existence of weak solutions relies on an energy estimate (Leray energy inequality) and on a compactness lemma in ( ( L t 2 L x 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315373393/e1c1ff9e-5083-409e-83f8-9c892d4b410a/content/eq5246.tif"/> which goes back to the Rellich lemma.
