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.
Last updated on 5 min read research

A quick introduction of Newton-Cartan theory, which is a sort of Newtonian limit of general relativity from a geometric point of view.
Last updated on 32 min read expository

A quick summary of the traceless version of general relativity.
Last updated on 8 min read mathematical diversions

About the Einstein-Infeld-Hoffmann theorem characterizing geodesics.
Last updated on 5 min read expository

We explain how to conformally compactify pseudo-Euclidean spaces with $(p,q)$ signature.
Last updated on 4 min read expository

Can initial data for Einstein's equation be specified in such a way that all the 'energy' are kinetic and not potential?
Last updated on 4 min read mathematical diversions

Paper announcement.
Last updated on 5 min read research

We show that trapped surfaces cannot exist in (2+1) dimensional relativity.
Last updated on 8 min read expository

Life is boring in low dimensions.
Last updated on 3 min read expository

The relationship between gravitational red shift and the surface gravity of black holes is explained.
Last updated on 2 min read expository