- #1
gerald V
- 67
- 3
Commonly it is said that the gravitational field has 6 degrees of freedom (a symmetric tensor, that is 10, minus 4 conservation laws). But is this accepted without any dispute?
The reason for my question are so called "indirectly coupling" models, where the primary gravitational field is something, and this something creates the metric of spacetime which couples in the usual way. In the 1970s, Wei-Tou-Ni had a scalar as the primary field. So this distinguished expert deemed possible that the gravitational field only has a single dof.
Ni`s theory was not successful, but meanwhile there are considerations to have a primary vector field, what would mean 4 dof at most (if there are no further restrictions on this vector field).
Thank you very much in advance!
The reason for my question are so called "indirectly coupling" models, where the primary gravitational field is something, and this something creates the metric of spacetime which couples in the usual way. In the 1970s, Wei-Tou-Ni had a scalar as the primary field. So this distinguished expert deemed possible that the gravitational field only has a single dof.
Ni`s theory was not successful, but meanwhile there are considerations to have a primary vector field, what would mean 4 dof at most (if there are no further restrictions on this vector field).
Thank you very much in advance!