The Kato square root problem for mixed boundary value problems

Research paper by Andreas Axelsson, Stephen Keith, Alan McIntosh

Indexed on: 24 Oct '05Published on: 24 Oct '05Published in: Mathematics - Analysis of PDEs


We solve the Kato square root problem for second order elliptic systems in divergence form under mixed boundary conditions on Lipschitz domains. This answers a question posed by J.-L. Lions in 1962. To do this we develop a general theory of quadratic estimates and functional calculi for complex perturbations of Dirac-type operators on Lipschitz domains.