General Relativity

Posts on Einstein's general theory of relativity, both from the physical and mathematical points of views.

I try to reformulate an idea of Capoferri and Vassiliev in the infinitesimal limit and see where it goes.

A quick introduction of Newton-Cartan theory, which is a sort of Newtonian limit of general relativity from a geometric point of view.

A quick summary of the traceless version of general relativity.

About the Einstein-Infeld-Hoffmann theorem characterizing geodesics.

We explain how to conformally compactify pseudo-Euclidean spaces with $(p,q)$ signature.

Can initial data for Einstein's equation be specified in such a way that all the 'energy' are kinetic and not potential?

We show that trapped surfaces cannot exist in (2+1) dimensional relativity.

Life is boring in low dimensions.

The relationship between gravitational red shift and the surface gravity of black holes is explained.