Classical and quantum aspects of a dilaton force in two dimensions

The nature of gravity is clarified in two-dimensional dilaton gravity theories, including the known quantum correction. It is established that a local massive body put in the vacuum generates an attractive force, as recognized by the geodesic deviation, both in the original and the reversed CGHS models, but the range and the temporal evolution of the force are markedly different in the two cases. In the reversed model the varying coupling strength governs the time variation of the attractive force, and the quantum correction adds a new feature, giving rise to a propagating component of the gravity force.