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We present a new way of looking at the very long term evolution of GRBs inwhich the disk of material surrounding the putative black hole powering the GRBjet modulates the mass flow, and hence the efficacy of the process thatextracts rotational energy from the black hole and inner accretion disk. Thepre-Swift paradigm of achromatic, shallow-to-steep "breaks" in the long termGRB light curves has not been borne out by detailed Swift data amassed in thepast several years. We argue that, given the initial existence of a fall-backdisk near the progenitor, an unavoidable consequence will be the formation ofan "external disk" whose outer edge continually moves to larger radii due toangular momentum transport and lack of a confining torque. The mass reservoirat large radii moves outward with time and gives a natural power law decay tothe GRB light curves. In this model, the different canonical power law decaysegments in the GRB identified by Zhang et al. and Nousek et al. representdifferent physical states of the accretion disk. We identify a physical diskstate with each power law segment.

A New Paradigm for Gamma Ray Bursts: Long Term Accretion Rate Modulation by an External Accretion Disk