Abstract
The aim of this paper is to classify 4-dimensional Einstein-like manifolds whose Ricci tensor has constant eigenvalues (this being a special kind of curvature homogeneity condition). We give a full classification when the Ricci tensor is of Codazzi type; when the Ricci tensor is cyclic parallel, we classify all such manifolds when not all Ricci curvatures are distinct. In this second case we find a one-parameter family of Riemannian metrics on a Lie groupG as the only possible ones which are irreducible and non-symmetric.
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Derdzinski, A.: The caseDr ∈C ∞ (Q 0 ⊺Q 1): Riemannian manifolds with harmonic Weyl tensor,A section of “Special manifolds”, first version, Preprint. (Unpublished first version of section D of Chapter 16 in A. Besse (ed),Einstein Manifold, Ergebnisse der Mathematik und ihrer Grenzgebiete, 3. Folge, Band 10, Springer-Verlag, Berlin, 1987).
Gray, A.: Einstein-like manifolds which are not Einstein,Geom. Dedicata 7, (1978), 259–280.
Jensen, G.R.: Homogeneous Einstein spaces of dimension 4,J. Differential Geom. 3 (1969), 309–349.
Kowalski, O.: A classification of Riemannian 3-manifolds with constant principal Ricci curvatures ρ1=ρ2 ≠ ρ3, Preprint, 1992.
Kowalski, O. and Vanhecke, L.: Four-dimensional naturally reductive homogeneous spaces,Rend. Sem. Mat. Univ. Politec. Torino, Fascicolo Speciale (1983), 223–232.
O'Neill, B.: The fundamental equations of a submersion,Michigan Math. J. 13 (1966), 459–469.
Tricerri, F. and Vanhecke, L.: Curvature homogeneous Riemannian manifolds,Ann. Sci. École Norm. Sup. (4)22 (1989), 525–554.
Yamato, K.: A characterization of locally homogeneous Riemann manifolds of dimension 3,Nagoya Math. J. 123 (1991), 77–90.
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Podestà, F., Spiro, A. Four-dimensional Einstein-like manifolds and curvature homogeneity. Geom Dedicata 54, 225–243 (1995). https://doi.org/10.1007/BF01265339
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DOI: https://doi.org/10.1007/BF01265339