Lau, A.T-MLoy, Richard2015-12-070022-1236http://hdl.handle.net/1885/25479In this paper, we explore the properties of projections of norm one on general Banach algebras, in particular the relation with conditional expectations for algebras which arise in harmonic analysis.Keywords: Banach algebra; Conditional expectation; Fourier algebra; Group algebra; Group von Neumann algebra; Locally compact group; Measure algebra; Norm one projection200810.1016/j.jfa.2008.02.0082015-12-07