Rapidly rotating neutron stars with a massive scalar field - structure and universal relations

Understand

We construct rapidly rotating neutron star models in scalar-tensor theories with a massive scalar field.

• The fact that the scalar field has nonzero mass leads to very interesting results since the allowed range of values of the coupling parameters is significantly broadened.
• These deviations from pure general relativity can be very large for values of the parameters that are in agreement with the observations.
• The rapid rotation can magnify the differences several times compared to the static case.