Results 71 to 80 of about 2,123 (99)

Nearly Sasakian manifolds revisited

Complex Manifolds, 2019
We provide a new, self-contained and more conceptual proof of the result that an almost contact metric manifold of dimension greater than 5 is Sasakian if and only if it is nearly Sasakian.
Cappelletti-Montano Beniamino, De Nicola Antonio, Dileo Giulia, Yudin Ivan   +3 more
doaj   +1 more source

D'Atri spaces and the total scalar curvature of hemispheres, tubes and cylinders. [PDF]

Rev Mat Complut, 2023
Csikós B, Elnashar A, Horváth M.
europepmc   +1 more source

An Inequality on Quaternionic CR-Submanifolds

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2018
We establish an inequality for an intrinsic invariant of Chen-type defined on quaternionic CR-submanifolds in quaternionic space forms, in terms of the squared mean curvature, the main extrinsic invariant, by using the method of constrained extrema.
Macsim Gabriel, Mihai Adela
doaj   +1 more source

Sasakian structures a foliated approach

Demonstratio Mathematica, 2017
Recent renewed interest in Sasakian manifolds is due mainly to the fact that they can provide examples of generalized Einstein manifolds, manifolds which are of great interest in mathematical models of various aspects of physical phenomena.
Wolak Robert A.
doaj   +1 more source

*-Ricci soliton on (κ, μ)′-almost Kenmotsu manifolds

Open Mathematics, 2019
Let (M, g) be a non-Kenmotsu (κ, μ)′-almost Kenmotsu manifold of dimension 2n + 1. In this paper, we prove that if the metric g of M is a *-Ricci soliton, then either M is locally isometric to the product ℍn+1(−4)×ℝn or the potential vector field is ...
Dai Xinxin, Zhao Yan, Chand De Uday
doaj   +1 more source

Riemannian invariants for warped product submanifolds in Qεm×R{{\mathbb{Q}}}_{\varepsilon }^{m}\times {\mathbb{R}} and their applications

Open Mathematics
This article investigates the geometric and topologic of warped product submanifolds in Riemannian warped product Qεm×R{{\mathbb{Q}}}_{\varepsilon }^{m}\times {\mathbb{R}}.
Li Yanlin, Alshehri Norah, Ali Akram
doaj   +1 more source

Mass and Extremals Associated with the Hardy–Schrödinger Operator on Hyperbolic Space

Advanced Nonlinear Studies, 2018
We consider the Hardy–Schrödinger operator Lγ:=-Δ𝔹n-γ⁢V2{L_{\gamma}:=-\Delta_{\mathbb{B}^{n}}-\gamma{V_{2}}} on the Poincaré ball model of the hyperbolic space 𝔹n{\mathbb{B}^{n}} (n≥3{n\geq 3}).
Chan Hardy, Ghoussoub Nassif, Mazumdar Saikat, Shakerian Shaya, de Oliveira Faria Luiz Fernando   +4 more
doaj   +1 more source

A new proof of the bound for the first Dirichlet eigenvalue of the Laplacian operator

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2014
In this paper, we present a new proof of the upper and lower bound estimates for the first Dirichlet eigenvalue λ1D(B(p,r))$\lambda _1^D \left({B\left({p,r} \right)} \right)$ of Laplacian operator for the manifold with Ricci curvature Rc ≥ −K, by using
Li Chang-Jun, Gao Xiang
doaj   +1 more source

Contact Structures of Sasaki Type and Their Associated Moduli

Complex Manifolds, 2019
This article is based on a talk at the RIEMain in Contact conference in Cagliari, Italy in honor of the 78th birthday of David Blair one of the founders of modern Riemannian contact geometry.
Boyer Charles P.
doaj   +1 more source

Gauge Theory on Projective Surfaces and Anti-self-dual Einstein Metrics in Dimension Four. [PDF]

J Geom Anal, 2018
Dunajski M, Mettler T.
europepmc   +1 more source