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Non-linear gravitational clustering in scalar field cosmologies

S. Matarrese·M. Pietroni·C. Schimd
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Abstract

Non-linear gravitational clustering in a universe dominated by dark energy, modelled by a `quintessence' scalar field, and cold dark matter with space-time varying mass is studied. Models of this type, where the variable mass is induced by dependence on the scalar field, as suggested by string theory or extra-dimensions, have been proposed as a viable solution of the coincidence problem. A general framework for the study of the non-linear phases of structure formation in scalar field cosmologies is provided, starting from a general relativistic treatment of the combined dark matter-dark energy system. As a first application, the mildly non-linear evolution of dark matter perturbations is obtained by a straightforward extension of the Zel'dovich approximation. We argue that the dark energy fluctuations may play an active role in cosmological structure formation if the scalar field effective potential develops a temporary spinodal instability during the evolution.

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S. Matarrese, M. Pietroni, C. Schimd. 2003-08-07. Non-linear gravitational clustering in scalar field cosmologies. https://doi.org/10.1088/1475-7516%2F2003%2F08%2F005

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