Resumen de On the ranges of bimodule projections

Aristides Katavolos, Vern I. Paulsen

• We develop a symbol calculus for normal bimodule maps over a masa that is the natural analogue of the Schur product theory. Using this calculus we are easily able to give a complete description of the ranges of contractive normal bimodule idempotents that avoids the theory of J*-algebras. We prove that if P is a normal bimodule idempotent and ||P|| < 2/sqrt{3} then P is a contraction. We finish with some attempts at extending the symbol calculus to non-normal maps.