Constraining the Rastall parameters in static spacetimes with galaxy-scale strong gravitational lensing

Understand

Recently, Rastall gravity is undergoing a significant surge in popularity.

• We obtain a power-law total mass-density profile for the inner region (within several effective radius) of early-type galaxies (ETGs) from the space-time structures which are described by the static spherically-symmetric solutions of Rastall gravity under the assumption of perfect fluid matter.
• We find that in the inner region of ETGs, the Rastall dimensionless parameter $\beta=\kappa\lambda$ determines the mass distribution.
• We then use 118 galaxy-galaxy strong gravitational lensing systems to constrain the Rastall dimensionless parameter $\beta$.