Self-dual manifolds with non-negative ricci operator

Author(s):  
Paul Gauduchon
Keyword(s):  

Filomat ◽  
2019 ◽  
Vol 33 (8) ◽  
pp. 2355-2365
Author(s):  
Irem Küpeli

Mainly, we prove that the Ricci operator Q of an 3-dimensional almost paracosymplectic manifold M is invariant along the Reeb flow, that is M satisfies L?Q = 0 if and only if M is an almost paracosymplectic k-manifold with k ? -1.



2014 ◽  
Vol 38 ◽  
pp. 920-923 ◽  
Author(s):  
Dong Ho LIM ◽  
Woon Ha SOHN ◽  
Seong-Soo AHN


1989 ◽  
Vol 108 (2-3) ◽  
pp. 211-217 ◽  
Author(s):  
Philippe Tondeur ◽  
Lieven Vanhecke


Mathematics ◽  
2018 ◽  
Vol 6 (11) ◽  
pp. 246
Author(s):  
Yan Zhao ◽  
Wenjie Wang ◽  
Ximin Liu

Let M be a three-dimensional trans-Sasakian manifold of type ( α , β ) . In this paper, we obtain that the Ricci operator of M is invariant along Reeb flow if and only if M is an α -Sasakian manifold, cosymplectic manifold or a space of constant sectional curvature. Applying this, we give a new characterization of proper trans-Sasakian 3-manifolds.



2020 ◽  
Vol 1597 ◽  
pp. 012049
Author(s):  
Uppara Manjulamma ◽  
H G Nagaraja ◽  
D L Kiran Kumar


2010 ◽  
Vol 03 (04) ◽  
pp. 577-591 ◽  
Author(s):  
Amalendu Ghosh

In this paper we study 3-dimensional contact metric manifolds satisfying certain conditions on the tensor fields *-Ricci tensorS*, h(= ½Lξφ), τ(= Lξg = 2hφ) and the Ricci operator Q. First, we prove that a 3-dimensional non-Sasakian contact metric manifold satisfies. [Formula: see text] (where ⊕X,Y,Z denotes the cyclic sum over X,Y,Z) if and only if M is a generalized (κ, μ)-space. Next, we prove that a 3-dimensional contact metric manifold with vanishing *-Ricci tensor is a generalized (κ, μ)-space. Finally, some results on 3-dimensional contact metric manifold with cyclic η-parallel h or cyclic η-parallel τ or η-parallel Ricci tensor are presented.



2017 ◽  
Vol 40 (1) ◽  
pp. 102-116
Author(s):  
Jong Taek Cho ◽  
Sun Hyang Chun


2017 ◽  
Vol 1 ◽  
Author(s):  
P.N. Klepikov ◽  
◽  
E.D. Rodionov ◽  


1996 ◽  
Vol 39 (3) ◽  
pp. 352-359 ◽  
Author(s):  
Joon-Sik Park ◽  
Won Tae Oh

AbstractThe Abbena-Thurston manifold (M,g) is a critical point of the functional where Q is the Ricci operator and R is the scalar curvature, and then the index of I(g) and also the index of — I(g) are positive at (M,g).



Author(s):  
S.V. Klepikova ◽  
T.P. Makhaeva

It is known that a locally homogeneous manifold can be obtained from a locally conformally homogeneous (pseudo)Riemannian manifolds by a conformal deformation if the Weyl tensor (or the Schouten-Weyl tensor in the three-dimensional case) has a nonzero squared length. Thus, the problem arises of studying (pseudo)Riemannian locally homogeneous and locally conformally homogeneous manifolds, the Weyl tensor of which has zero squared length, and itself is not equal to zero (in this case, the Weyl tensor is called isotropic). One of the important aspects in the study of such manifolds is the study of the curvature operators on them, namely, the problem of restoring a (pseudo)Riemannian manifold from a given Ricci operator. The problem of the prescribed values of the Ricci operator on 3-dimensional locally homogeneous Riemannian manifolds has been solved by O. Kowalski and S. Nikcevic. Analogous results for the one-dimensional and sectional curvature operators were obtained by D.N. Oskorbin, E.D. Rodionov, and O.P Khromova. This paper is devoted to the description of an example of studying the problem of the prescribed Ricci operator for four-dimensional locally homogeneous (pseudo) Riemannian manifolds with a nontrivial isotropy subgroup and isotropic Weyl tensor.



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