The first images of black hole shadows open new possibilities to constrain modern extended gravity theories. We present the method shadow background calculation for solutions in form Taylor series where g11 = – $$g_{{00}}^{{ - 1}}$$ . is general nonrotating case ≠ results analysis are compared with predictions General relativity taking into account Event Horizon Telescope data. Horndesky model ...

We study the fundamentals of quantum field theory on a rigid de Sitter space. show that perturbative expansion late-time correlation functions to all orders can be equivalently generated by non-unitary Lagrangian Euclidean AdS geometry. This finding simplifies dramatically computations, as well allows us establish basic properties these correlators, which comprise CFT. use this infer analytic s...