energy condition
Urs Schreiber
physics, mathematical physics, philosophy of physics
theory (physics), model (physics)
experiment, measurement, computable physics
Axiomatizations
Tools
Structural phenomena
Types of quantum field thories
examples
The theory of classical gravity (general relativity) a priori and straightforwardly admits the coupling to gravity of (matter-)fields with any covariant local Lagrangian. The resulting Einstein equations will always exist and will equate the Einstein tensor with the given...