Garvey-Kelson relations for nuclear charge radii

The Garvey-Kelson relations (GKRs) are algebraic expressions originally developed to predict nuclear masses. In this paper we show that the GKRs provide a fruitful framework for the prediction of other physical observables that also display a slowly varying dynamics. Based on this concept, we extend the GKRs to the study of nuclear charge radii. The GKRs are tested on 455 out of the approximately 800 nuclei whose charge radius is experimentally known. We find a rms deviation of 0.01fm between the GK predictions and the experimental values. Predictions are provided for 116 nuclei whose charge radius is presently unknown.