Manifest supersymmetry for BPS walls in N=2 nonlinear sigma models

BPS equations and wall solutions are studied keeping (part of) supersymmetry (SUSY) manifest. Using N=1 superfields, massive hyper-Kaehler quotient is introduced to obtain massive N=2 (8 SUSY) nonlinear sigma models in four dimensions with T*CPn target manifold, which yield BPS wall solutions for the n=1 case. We also describe massive hyper-Kaehler quotient of T*CPn by using the harmonic superspace formalism which preserves all SUSY manifestly, and BPS equations and wall solutions are obtained in the n=1 case