In galaxy clusters the entropy distribution of the intraclusterplasma (ICP) modulates the latter's equilibrium within the dark mattergravitational wells, as rendered by our supermodel. Weargue the entropy production at the boundary shocks to be reduced orterminated as the accretion rates of DM and intergalactic gas peterout; this behavior is enforced by the slowdown in the outskirtdevelopment at late times, when the dark energy dominates the cosmologywhile the outer wings of the initial perturbation drive the growth. Forthese conditions, we predict the ICP temperature profiles to steepeninto the cluster outskirts. The detailed expectations from our simpleformalism agree with the X-ray data concerning five clusters whosetemperature profiles have been recently measured out to the virialradius. We predict steep temperature declines to prevail in clusters atlow z, tempered only by rich environs including adjacent filamentary structures.Key words: galaxies: clusters: general - X-rays: galaxies: clusters - methods: analytical
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