Enhancement of thermonuclear reaction rates in dense stars.

The rate of nuclear reactions in dense matter is highly enhanced by many-body effects. In this paper we calculate the enhancement factor for non-resonant nuclear reaction rates. We assume the matter to be fluid, and analytical fitting formulae are given for a wide range of temperatures and densities. We mainly assume only one ion component to be present but the generalisation to multi-component mixtures is straightforward when the charge difference between the components is small. The effect of electron screening is investigated and shown to be small in contrast to what was found in some earlier calculations. This has a substantial effect on the carbon ignition curve and the physical implications from this are discussed.