부산대학교 도서관

Spacetimes with axial and timelike Killing fields eta/sup ..mu../ and xi/sup ..mu../ respectively are studied. A natural basis is constructed for the steady state configurations of matter with 4-velocity u/sup ..mu../ =..cap alpha..xi/sup ..mu../+..beta..eta/sup ..mu../. It is shown that the rate of shear tensor always has an eigenvector with zero eigenvalue lying in the 2-space of Killing orbits. A natural coordinate system is constructed on the 2-space of Killing orbits for rigidly rotating perfect matter. Gravitational isorotation is proved for the case of a perfect fluid with a one-parameter equation of state. Locally nonrotating frames are constructed for purely stationary spacetimes.