Chameleon screening on non-spherical compact objects

Joan Bachs Esteban, Javier Rubio, Ilídio Lopes


Dark energy is the name of probably the most relevant problem in cosmology, and there is still no convincing solution to it. However, we can all agree that we need to go beyond Lambda-CDM and the SM to solve it. One of the ways to explain the accelerated expansion of the universe consists of adding a light scalar field that couples to matter. Nevertheless, might this field exist, we would need to explain how come it eluded detection in our planet and solar system. This discrepancy can be resolved by introducing a screening mechanism. From the plethora of theories, we are interested in studying the Chameleon field. It has been shown that an elliptical source enhances the chameleon force, something that gives hope to future laboratory detection. Furthermore, we are interested in studying this phenomenon in an astrophysical context. An ellipsoidal compact object, such as a dark matter halo, presents a physical problem closer to a real scenario, as well as non-radial perturbations - opposed to radial oscillations. A dynamical study of such objects is still unexplored, thus we hope to gain insight into this complex configuration, in addition to a deeper treatment of the spherical limit.