Mean specific intensity of the EUV background expected from clusters at the current epoch for three distinct cosmologies. The solid curve represents an open universe (﹩\Omega _{0}=0.3,\Omega _{\Lambda }=0﹩), the dashed curve a flat universe (﹩\Omega _{0}=0.3,\Omega _{\Lambda }=0.7﹩), and the dotted curve a closed universe (﹩\Omega _{0}=1.0,\Omega _{\Lambda }=0﹩). Absorption effects are ignored.