nLab general relativity

Contents

Context

Gravity

Physics

physics, mathematical physics, philosophy of physics

Surveys, textbooks and lecture notes


theory (physics), model (physics)

experiment, measurement, computable physics

Contents

Idea

The theory called the theory of general relativity is a classical field theory that in physics describes the field of gravity.

In general relativity, physical spacetime is modeled in terms of differential geometry as a Lorentzian manifold whose pseudo-Riemannian metric – or rather the Levi-Civita connection that corresponds to it – encodes the field of gravity.

The action functional describing the dynamics of this field is the Einstein-Hilbert action, in which the field of gravity enters in terms of the integral of the scalar curvature of the Levi-Civita connection over spacetime.

As is usual in classical field theory, the physically realized configurations – here: Levi-Civita connections – are those that extremize this functional. The Euler-Lagrange equations characterizing these extrema are the Einstein equations.

Historically the theory of general relativity was developed by Albert Einstein based on the theory known as special relativity. Given the conceptual simplicity of the Einstein-Hilbert action, there are several variations of his original version of the theory that are immediately obtained by adding certain terms to the action functional. One of these generalization is supergravity, which extends the theory from ordinary differential geometry to supergeometry.

References

General

Textbook accounts:

Lecture notes:

and with focus on causal structure, the Penrose singularity theorem and related aspects:

Emphasis on mathematical physics

Introductory exposition:

See also

See also the references at gravity.

In relation to thermodynamics

In relation to thermodynamics

History

Last revised on February 27, 2024 at 14:11:31. See the history of this page for a list of all contributions to it.