Geodesic properties in terms of multipole moments in scalar-tensor theories of gravity

Understand

The formalism for describing a metric and the corresponding scalar in terms of multipole moments has recently been developed for scalar-tensor theories.

• We take advantage of this formalism in order to obtain expressions for the observables that characterise geodesics in terms of the moments.
• These expressions provide some insight into how the structure of a scalarized compact object affects observables.
• They can also be used to understand how deviations from general relativity are imprinted on the observables.