Results 291 to 300 of about 473,950 (309)

On quasi Einstein manifolds

Publicationes Mathematicae Debrecen, 2000
The authors define a quasi Einstein manifold to be a non-flat Riemannian manifold \((M^n,g)\), \(n>2\), such that its Ricci tensor \(S\) satisfies the condition \( S(X,Y)=a g(X,Y) + b A(X) A(Y), \) where \(a,b\neq 0\) are associated scalars and \(A\) is a non-zero associated 1-form such that \(g(X,U)=A(X)\), \(g(U,U)=1\).
Chaki, M. C., Maity, R. K.
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On $$\eta $$ η -Einstein Para-S-manifolds

Bulletin of the Malaysian Mathematical Sciences Society, 2015
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Fernández, Luis M., Prieto-Martín, A.
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Generalized Einstein manifolds

Journal of Geometry and Physics, 1995
The geometrization of physics, especially regarding the equations of electromagnetism and gravitation in general relativity, has been a vital problem of investigation for a long time. A. Einstein himself devoted the last several years of his life to realize this dream without success. However, taking grant of two axioms proposed by \textit{D. Hilbert} [
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On Einstein Hermitian manifolds

Monatshefte für Mathematik, 2007
The author shows that every compact Einstein Hermitian surface with constant *-scalar curvature is Kähler. The *-scalar curvature is the trace of the *-Ricci tensor that measures how far the structure is from being Kähler. When the dimension is \(4n+2\), the author gives an example of an Einstein Hermitian manifold with constant *-scalar curvature that
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ALMOST EINSTEIN-HERMITIAN MANIFOLDS

JP Journal of Geometry and Topology
In this paper, we show that every almost Einstein-Hermitian 4-manifold (i.e., almost Hermitian 4-manifold with -invariant Ricci tensor and harmonic Weyl tensor) is either Einstein or Hermitian. Consequently, we obtain that any almost Einstein-Hermitian 4-manifold which is not Einstein must be Hermitian and that every almost Einstein-Hermitian 4 ...
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Einstein Manifolds and Topology

1987
Which compact manifolds do admit an Einstein metric? Except in dimension 2 (see Section B of this chapter), a complete answer to this question seems out of reach today. At least, in dimensions 3 and 4, we can single out a few manifolds which definitely do not admit any Einstein metric.
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On an Einstein projective Sasakian manifold

2006
The author proves that a projectively flat Sasakian manifold is an Einstein manifold. Besides, if an Einstein-Sasakian manifold is projectively flat, then it is locally isometric with a unit sphere \(S^n(1)\). Finally, if in an Einstein-Sasakian manifold the relation \(K(X,Y)\cdot P = 0\) holds, then it is projectively flat.
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The Extension of Einstein Manifolds

1981
Of the many mathematical problems connected with general relativity, the extension problem has been chosen for discussion in this chapter, because it is concerned with the global geometrical and topological properties of Einstein manifolds, and those properties seem to me to constitute the most basically mathematical aspect of the theory.
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Gradient $$\rho $$-Einstein soliton on almost Kenmotsu manifolds

Annali dell?Università di Ferrara, 2019
V. Venkatesha, H. Aruna Kumara
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Kähler-Einstein metric on an open algebraic manifold

, 1984
R. Kobayashi
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