# I Infinite Rod in General Relativity

1. Jun 26, 2016

### t_r_theta_phi

What is the metric for the spacetime around an infinitely thin, infinitely long, uniform rod? Could it be written in the form

ds2 = A(r)dt2 + B(r)dr2 + C(r)dh2 + r22

where h is the coordinate along the rod and r is the radial coordinate, or would it be something more complicated?

2. Jun 27, 2016

### Markus Hanke

Maybe I'm wrong, but my first impulse would be to model this as a special case of a Tipler cylinder, with small radius and zero angular momentum, in which case your ansatz looks pretty good. Let's wait and see what the experts say