Abstract

Some motivation for an ether theory of gravitation is presented. The equations of one such theory, based on just one scalar field, are given. It is a preferred-frame theory with a flat background metric and a curved physical metric. Motion is governed by an extension of the special-relativistic form of Newton’s second law. The current status of the observational test is favourable. In particular, the new theory reduces to Newton’s when it has to, and it does explain the effects of gravitation on light rays. In the most general form of the metric, cosmic space expansion occurs with a cosmological time-dilation. Expansion is necessarily accelerated, according to that theory. An analytical cosmological solution is got for a general form of the matter tensor. Two kinds of scenarios are possible: either expansion from an infinite density at past infinity, or contraction-expansion cycles beginning and ending with infinite dilution, and with a bounce at a finite maximum density. In the most likely scenario, there is an infinite number of non-identical such cycles. The time scale for the current cycle is very large.