Undergrad 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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In this video I can see a person walking around lines of curvature on a sphere with an arrow strapped to his waist. His task is to keep the arrow pointed in the same direction How does he do this ? Does he use a reference point like the stars? (that only move very slowly) If that is how he keeps the arrow pointing in the same direction, is that equivalent to saying that he orients the arrow wrt the 3d space that the sphere is embedded in? So ,although one refers to intrinsic curvature...

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