I General Relativity: Is it Local?

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Spacetime in general relativity is modeled as a differential manifold, with each point associated with Minkowski spacetime where gravity is absent. The curvature of spacetime, which represents gravity, can be defined by examining an infinitesimally small neighborhood around a point. General relativity is considered local because its Lagrangian depends solely on the fields and their derivatives at a single spacetime point. The discussion confirms that evaluating curvature requires only a small neighborhood, reinforcing the local nature of general relativity. Thus, general relativity is indeed local in its formulation and application.
accdd
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Spacetime is a differential manifold and at each point is attached a Minkowski spacetime.
There the laws of physics are the usual ones without gravity.
Gravity is the curvature of spacetime. To define the concept of curvature do we need to evaluate at least one neighborhood of point P? Is general relativity local?
 
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As all so far successful relativistic field theories also GR is local, i.e., it's Lagrangian depends on the fields and its derivatives at a single spacetime point.
 
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accdd said:
To define the concept of curvature do we need to evaluate at least one neighborhood of point P? Is general relativity local?
An infinitesimally small neighborhood suffices for that purpose, so yes, it's local.
 
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Moderator's note: Spin-off from another thread due to topic change. In the second link referenced, there is a claim about a physical interpretation of frame field. Consider a family of observers whose worldlines fill a region of spacetime. Each of them carries a clock and a set of mutually orthogonal rulers. Each observer points in the (timelike) direction defined by its worldline's tangent at any given event along it. What about the rulers each of them carries ? My interpretation: each...

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