Exact solutions for static spherically symmetric spacetime with a perfect fluid in Rastall theory
arXiv:2607.26463
The paper derives exact static, spherically symmetric solutions with a perfect fluid in Rastall's modified gravity theory, relating the Rastall parameter to the fluid equation‑of‑state parameter and extending known general‑relativity solutions.
Abstract
In general relativity, exact Liouvillian solutions for a static and spherically symmetric spacetime with a perfect fluid and the equation of state are known only for . We extend this setup to Rastall's theory, presenting the relation between the Rastall parameter and the constant , and deriving exact solutions that correspond to the known counterparts in general relativity, except for . Furthermore, we find that, when , there exist several types of solutions whose behavior changes depending on the choice of constants.
12 pages