Ultra long lived quasinormal modes of neutron stars in massive scalar-tensor gravity

Understand

The spectrum of frequencies and characteristic times that compose the ringdown phase of gravitational waves emitted by neutron stars carries information about the matter content (the equation of state) and the underlying theory of gravity.

• Typically, modified theories of gravity introduce additional degrees of freedom/fields, such as scalars, which result in new families of modes composing the ringdown spectrum.
• Simple but physically promising candidates are scalar-tensor theories, which effectively introduce an additional massive scalar field (i.e.
• an ultra-light boson) that couples non-minimally to gravity, resulting in scalarized neutron stars.