Metric signature
= Metric signature
{title2=$(-,+,+,+)$}
The <metric signature> records the signs of the diagonalized nondegenerate <metric tensor>, equivalently its numbers of negative and positive directions. For a four-dimensional <Lorentzian manifold>, both $(-,+,+,+)$ and its overall negative convention are common. The numerical signs of contractions and component <Hodge star operator> identities must be consistent with that choice and the <orientation>.