Giovanni Calvaruso (2010)
Archivum Mathematicum
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We study conformally flat Lorentzian three-manifolds which are either semi-symmetric or pseudo-symmetric. Their complete classification is obtained under hypotheses of local homogeneity and curvature homogeneity. Moreover, examples which are not curvature homogeneous are described.
Haesen, Stefan, Verstraelen, Leopold (2009)
SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
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Binh, T.Q., De, U.C., Tamássy, L. (2002)
Acta Mathematica Academiae Paedagogicae Nyí regyháziensis. New Series [electronic only]
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Uday Chand De, Avik De (2012)
Czechoslovak Mathematical Journal
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The object of the present paper is to study almost pseudo-conformally symmetric Ricci-recurrent manifolds. The existence of almost pseudo-conformally symmetric Ricci-recurrent manifolds has been proved by an explicit example. Some geometric properties have been studied. Among others we prove that in such a manifold the vector field corresponding to the 1-form of recurrence is irrotational and the integral curves of the vector field are geodesic. We also study some global properties...
W. Roter (1991)
Colloquium Mathematicae
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Fu, Fengyun, Zhao, Peibiao (2010)
Bulletin of the Malaysian Mathematical Sciences Society. Second Series
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Norio Hashimoto, Masami Sekizawa (2000)
Archivum Mathematicum
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An explicit classification of the spaces in the title is given. The resulting spaces are locally products or locally warped products of the real line and two-dimensional spaces of constant curvature.