General relativity limit of the scalar-tensor theories for traceless matter field

$\omega (\varphi )\to \mathrm{\infty }$ limit of scalar tensor theories are studied for traceless matter source. It is shown that the limit $\omega (\varphi )\to \mathrm{\infty }$ does not reduce a scalar tensor theory to general relativity. An exact radiation solution of scalar tensor cosmology under Nordtvedt conditions is obtained for flat Friedmann universe.