Cosmological constant and the fate of the DDM theory

We investigate the impact of the non-zero cosmological constant on the clas sical decaying dark matter theory developed by the late Dennis Sciama. In p articular, we concentrate on the change in relevant values of cosmological parameters in comparison to the high-precision estimates given by Sciama (1 997). It is shown that the appropriate changes in resulting parameter value s are such to make the DDM concept less plausible. This is in complete agre ement with recently reported observational results detrimental to this theo ry.