On the role of pressure in generating the gravitational field

Abstract

The Einstein equations for static gravitational field depend on energy density and pressure. So one may expect that solutions should depend on two parameters: mass and its analogue originated from pressure. Yet the Schwarzschild solution have only mass parameter. So does its linear approximation. On the other hand the solutions of linearized Einstein equations, obtained using graviton propagator, contain mass and its pressure analogue. This suggests that a phenomenological approach to gravity, using propagators and many graviton vertices, should lead to a theory different from general relativity.