A new way to test general relativity?
The trajectory of vibrating systems in general relativity differs from a free fall trajectory. This could lead to a new way of testing the theory of general relativity.
The phenomenology of general relativity is usually puzzling and counterintuitive. Recently Guéron et al. predicted an effect of relativistic glider : a vibrating system falling radially towards a central mass can be accelerated or decelerated by means of assymetric oscillations. We confirmed and analysed in more details this statement. However, this effect is very weak and is decreasing when the initial distance between the system and the central body is increasing . It is therefore impossible to detect it around an object of the solar system.
On the other hand, this study has shown that the effect increases linearly with time. A simple way to increase the duration of the experiment is to perform it in a circular orbit. The analysis of the same system in a quasi-circular orbit has shown completely different features. For a vibrating system, the orbit becomes elliptic - see the simulation below - and the assymetry of the oscillations has few effects, contrary to the case of the radial fall. Moreover, this deviation effect increases linearly with the distance from the central body, when the Newtonian deviation effect decreases. We estimated the deviation from the circular orbit to be of the order of five centimeters for a highly excited molecule in a high Earth orbit .
Although more realistic experiments have to be studied, we think that this effect could lead to a new way of testing general relativity.
Simulation of a vibrating system in a quasi-cicular orbit around a central mass. The circular reference orbit is in red.
Have a look at our project page on vibrating systems in general relativity or contact Pacôme Delva () from the Advanced Concepts Team.
E. Guéron and R.A. Mosna, "The relativistic glider," Physical Review D 75 (2007) 081501.
L. Bergamin, P. Delva and A. Hees, "Vibrating systems in Schwarzschild spacetime: I - The radial fall", gr-qc:09012298
L. Bergamin, P. Delva and A. Hees, "Vibrating systems in Schwarzschild spacetime: II - The quasi-circular orbit", gr-qc:09012306