Nonlinear maps preserving Jordan triple η-⁎-products.

Let η ≠ − 1 be a non-zero complex number, and let ϕ be a not necessarily linear bijection between two von Neumann algebras, one of which has no central abelian projections, satisfying ϕ ( I ) = I and preserving the Jordan triple η -⁎-product. It is showed that ϕ is a linear ⁎ -isomorphism if η is not real and ϕ is the sum of a linear ⁎ -isomorphism and a conjugate linear ⁎ -isomorphism if η is real. [ABSTRACT FROM AUTHOR]