Seminarium "Teoria cząstek elementarnych i kosmologia"

In the effective field theory approach to gravity, the Lagrangian density for general relativity is supplemented by generally covariant terms of higher order in the Riemann tensor and its derivatives. At face value, these terms will result in higher derivative equations of motion and additional degrees of freedom beyond those of general relativity. This is seemingly at odds with the goal of effective field theory which is to encode ultraviolet corrections in terms of existing low energy degrees of freedom. An action-based procedure for the removal of spurious degrees of freedom is considered for the case of general relativity in the presence of such additional terms, resulting in an extension to general relativity that does not introduce new degrees of freedom in the gravitational sector.