# What is a lapse function

1. Nov 15, 2011

### Mazulu

Last edited: Nov 15, 2011
2. Nov 17, 2011

### atyy

GR as a 4D geometrical theory involves equations that relate the 4D spacetime metric and matter.

GR can be reformulated as a 3D theory with time evolution, provided spacetime topology isn't weird. The lapse is a function that appears in the 3+1 version. http://arxiv.org/abs/gr-qc/0703035

Last edited: Nov 17, 2011