Solutions of gravitational field equations (Q1891483)

The authors search for cosmological solutions in Einstein's theory. Gravitation is coupled to a mass density, an isotropic pressure, and a radial heat flow. The spherically symmetric ansatz (1) contains, unfortunately, a misprint: the coefficient of \(dr^2\) should actually read \((1 - kr^2/R^2)^{-1}\). The result is claimed to generalize the \(k = 0\) case already treated by Deng in 1989. But some transformation of the radial variable \(r\), well known for the Robertson-Walker metrics, would remove \(k\) so that the paper only reproduces Deng's work.