[{"n": "Einstein field equations", "u": "/e/relativity-and-gravitation/einstein-field-equations/", "s": "Tensor equations linking spacetime geometry to matter-energy."}, {"n": "Energy–momentum relation", "u": "/e/relativity-and-gravitation/energy-momentum-relation/", "s": "Relativistic equation linking energy, mass, and momentum."}, {"n": "Four-momentum", "u": "/e/relativity-and-gravitation/four-momentum/", "s": "Four-vector combining energy and momentum in special relativity."}, {"n": "Four-vector", "u": "/e/relativity-and-gravitation/four-vector/", "s": "A four-component vector transforming under Lorentz transformations in special relativity."}, {"n": "General covariance", "u": "/e/relativity-and-gravitation/general-covariance/", "s": "Principle that physical laws are independent of coordinate choices."}, {"n": "Geodesics in general relativity", "u": "/e/relativity-and-gravitation/geodesics-in-general-relativity/", "s": "Geodesics describe the paths of freely falling particles in curved spacetime."}, {"n": "Gravitational constant", "u": "/e/relativity-and-gravitation/gravitational-constant/", "s": "Fundamental constant quantifying gravitational force strength."}, {"n": "Gravitational field", "u": "/e/relativity-and-gravitation/gravitational-field/", "s": "A vector field explaining gravitational influences around a body."}, {"n": "Gravitational potential", "u": "/e/relativity-and-gravitation/gravitational-potential/", "s": "Scalar potential representing work per unit mass in a gravitational field."}, {"n": "Gravitational singularity", "u": "/e/relativity-and-gravitation/gravitational-singularity/", "s": "A point where spacetime breaks down catastrophically."}, {"n": "Gravitational time dilation", "u": "/e/relativity-and-gravitation/gravitational-time-dilation/", "s": "Time passes slower nearer a massive body."}, {"n": "Gravitational wave", "u": "/e/relativity-and-gravitation/gravitational-wave/", "s": "Gravitational waves are waves of spacetime curvature produced by the relative motion of gravitating masses, pr"}, {"n": "Hawking radiation", "u": "/e/relativity-and-gravitation/hawking-radiation/", "s": "Predicted black-body radiation from black holes due to quantum effects."}, {"n": "Inertial frame of reference", "u": "/e/relativity-and-gravitation/inertial-frame-of-reference/", "s": "Frame where objects obey inertia and laws are simplest."}, {"n": "Invariant (physics)", "u": "/e/relativity-and-gravitation/invariant-physics/", "s": "An observable unchanged under a transformation."}, {"n": "Kerr–Newman metric", "u": "/e/relativity-and-gravitation/kerr-newman-metric/", "s": "Most general asymptotically flat stationary electrovacuum solution of Einstein–Maxwell equations."}, {"n": "Ladder paradox", "u": "/e/relativity-and-gravitation/ladder-paradox/", "s": "A thought experiment on length contraction and simultaneity."}, {"n": "Length contraction", "u": "/e/relativity-and-gravitation/length-contraction/", "s": "A moving object's length is measured shorter than its proper length."}, {"n": "Faster-than-light", "u": "/e/relativity-and-gravitation/faster-than-light/", "s": "Hypothetical travel or communication faster than the speed of light."}, {"n": "Fifth force", "u": "/e/relativity-and-gravitation/fifth-force/", "s": "A hypothetical force beyond the four known fundamental interactions."}]