Acknowledgement
Supported by : Chonnam National University
References
- Global Lorentzian Geometry Beem, J.K.;Ehrlich, P.E.;Easley, K.L.
- Einstein Manifolds Besse, A.L.
- Trans. Amer. Math. Soc. v.145 Manifolds of negative curvature Bishop, R.L.;O'Neil, B.
- Bull. of Korean Math. Soc. v.35 no.4 A characterization of space forms Kim, D.S.;Kim, Y.H.
- Compact Einstein warped product spaces with nonpositive scalar curvature Kim, D.S.;Kim, Y.H.
- Conformal transformations between Einstein spaces;Conformal Geometry, Aspects of Math., E12 Kuhnel, W.
- Semi-Riemannian Geometry with applications to Relativity O'Neill, B.
- Proceedings of Differential Geometry Meeting Warped products and Einstein Manifolds (Joint work with A. Derdzinski and C. L. Terng) Palais, R.S.