Constraint on energy-momentum squared gravity from neutron stars and its cosmological implications

Understand

Deviations from the predictions of general relativity due to energy-momentum squared gravity (EMSG) are expected to become pronounced in the high density cores of neutron stars.

• We derive the hydrostatic equilibrium equations in EMSG and solve them numerically to obtain the neutron star mass-radius relations for four different realistic equations of state.
• We use the existing observational measurements of the masses and radii of neutron stars to constrain the free parameter, $\alpha ,$ that characterizes the coupling between matter and spacetime in EMSG.
• We show that $-10^{-38}\,\mathrm{cm^{3}/erg}<\alpha <+10^{-37}\,\mathrm{cm^{3}/erg}$.