η ′ 1 μ ν
η ′ 2 μ ν
η ′ 3 μ ν
( − 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 )
( − 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 )
( − 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 )