Recent content by TimWilliams87

I am learning about Fermi normal coordinates for an inertial observer on a reference curve from the textbook ''Advanced general relativity'' by Eric Poisson. The metric is written as g = eta + h, where eta is the Minkowski metric and h is the spacetime curvature perturbation close to the...

So does that mean the ##t## component of the tangent vector is constant (isn't ##dt/d\tau = 1##) and that the spatial components of the tangent vector finish (since they contain ##t## but the derivative is with respect to ##\tau##?

I am considering the definition of a tangent vector field ##\psi^{\mu}## to a timelike geodesic and slightly confused as to how it works for spacetimes. If a curve is parametrised by some parameter ##\lambda##, the tangent to the curve is given by a four-vector ##dx^{\mu}/ d \lambda##, as...

I actually think the scheme described by Pervect is what I need. Is it explained in MTW how to obtain the metric when there are two particles moving slowly parallel to each other for a short period of time? Is g_{00} a superposition law in this case for the contributions from both particles?

I am thinking about a situation in general relativity which may be in textbooks but I have not been able to find it. I appreciate that there is the geodesic deviation equation for the world line of an observer and a nearby free-falling particle, but I think I need something different. So we...

The reference is the paper you mention https://arxiv.org/abs/1104.0062, the other quotation was from correspondence with someone working in the area so I cannot really reference it.

[SIZE=13px][FONT=Arial][FONT=Georgia]I have recently been reading some stuff on quantum information in the physics literature which refers to 'a mechanism by which a measurement in A determines quantum coherences in B', where A and B are subsystems of a larger system...