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Related papers: Approximation of Regular Sasakian Manifolds

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In this short note we show the following result: Let $(M^{2n+1},g)$ ($n \geq 2$) be a compact Sasaki manifold with positive transverse orthogonal bisectional curvature. Then $\pi_1(M)$ is finite, and the universal cover of $(M^{2n+1},g)$ is…

Differential Geometry · Mathematics 2013-01-10 Hong Huang

For a complete noncompact connected Riemannian manifold with bounded geometry, we prove a compactness result for sequences of finite perimeter sets with uniformly bounded volume and perimeter in a larger space obtained by adding limit…

Metric Geometry · Mathematics 2015-04-21 Abraham Enrique Muñoz Flores , Stefano Nardulli

This work is motivated by two problems: 1) The approach of manifolds and spaces by triangulations. 2) The complexity growth in sequences of polyhedra. Considering both problems as related, new criteria and methods for approximating smooth…

Differential Geometry · Mathematics 2012-05-22 Daniel J. Pons

We investigate the compact submanifolds in Riemannian space forms of nonnegative sectional curvature that satisfy a lower bound on the Ricci curvature, that bound depending solely on the length of the mean curvature vector of the immersion.…

Differential Geometry · Mathematics 2023-11-06 Marcos Dajczer , Theodoros Vlachos

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.…

Differential Geometry · Mathematics 2016-05-16 Robert Wolak

Akyol, M. A and \c{S}ahin, B. [Conformal semi-invariant submersions, Commun. Contemp. Math. 19, 1650011 (2017).] introduced the notion of conformal semi-invariant submersions from almost Hermitian manifolds. The present paper deal with the…

Differential Geometry · Mathematics 2018-05-23 Mehmet Akif Akyol

We provide integral curvature bounds for compact Riemannian manifolds that allow isometric immersions into a Euclidean space with low codimension in terms of the Betti numbers.

Differential Geometry · Mathematics 2011-11-16 Theodoros Vlachos

Given any finite subset X of the sphere S^n, n>1, which includes no pairs of antipodal points, we explicitly construct smoothly immersed closed orientable hypersurfaces in Euclidean space R^{n+1} whose Gauss map misses X. In particular,…

Differential Geometry · Mathematics 2010-10-26 Mohammad Ghomi

Let X be a compact (resp. compact and nonsingular) real algebraic variety and let Y be a homogeneous space for some linear real algebraic group. We prove that a continuous (resp. C^infinity) map f:X-->Y can be approximated by regular maps…

Algebraic Geometry · Mathematics 2020-12-23 Jacek Bochnak , Wojciech Kucharz

In this paper, we study some intrinsic characterization of conformally compact manifolds. We show that, if a complete Riemannian manifold admits an essential set and its curvature tends to -1 at infinity in certain rate, then it is…

Differential Geometry · Mathematics 2009-10-26 Xue Hu , Jie Qing , Yuguang Shi

We prove that closed surfaces of all topological types, except for the non-orientable odd-genus ones, can be minimally embedded in the Riemannian product of a sphere and a circle of arbitrary radius. We illustrate it by obtaining some…

Differential Geometry · Mathematics 2018-03-20 José M. Manzano , Julia Plehnert , Francisco Torralbo

In this article, we consider a complete, non-compact almost Hermitian manifold whose curvature is asymptotic to that of the complex hyperbolic plane. Under natural geometric conditions, we show that such a manifold arises as the interior of…

Differential Geometry · Mathematics 2024-05-28 Alan Pinoy

In this paper, we prove a Mergelyan type approximation theorem for immersed holomorphic Legendrian curves in an arbitrary complex contact manifold $(X,\xi)$. Explicitly, we show that if $S$ is a compact admissible set in a Riemann surface…

Complex Variables · Mathematics 2023-01-04 Franc Forstneric

The metrics of S. Y. Cheng and S.-T. Yau are considered on a strictly pseudoconvex domains in a complex manifold. Such a manifold carries a complete K\"{a}hler-Einstein metric if and only if its canonical bundle is positive. We consider the…

Differential Geometry · Mathematics 2015-03-17 Craig van Coevering

Given two arbitrary closed sets in Euclidean space, a simple transversality condition guarantees that the method of alternating projections converges locally, at linear rate, to a point in the intersection. Exact projection onto nonconvex…

Optimization and Control · Mathematics 2018-11-06 Dmitriy Drusvyatskiy , Adrian S. Lewis

We prove the following results: (i) A Sasakian metric as a non-trivial Ricci soliton is null $\eta$-Einstein, and expanding. Such a characterization permits to identify the Sasakian metric on the Heisenberg group $\mathcal{H}^{2n+1}$ as an…

Differential Geometry · Mathematics 2015-06-17 Amalendu Ghosh , Ramesh Sharma

Optimization on Riemannian manifolds widely arises in eigenvalue computation, density functional theory, Bose-Einstein condensates, low rank nearest correlation, image registration, and signal processing, etc. We propose an adaptive…

Optimization and Control · Mathematics 2017-08-08 Jiang Hu , Andre Milzarek , Zaiwen Wen , Yaxiang Yuan

In this work we consider a question in the calculus of variations motivated by riemannian geometry, the isoperimetric problem. We show that solutions to the isoperimetric problem, close in the flat norm to a smooth submanifold, are…

Differential Geometry · Mathematics 2020-07-16 Stefano Nardulli

In a recent article the first three authors proved that in dimension $4m+1$ all homotopy spheres that bound parallelizable manifolds admit Einstein metrics of positive scalar curvature which, in fact, are Sasakian-Einstein. They also…

Differential Geometry · Mathematics 2007-05-23 Charles P. Boyer , Krzysztof Galicki , János Kollár , Evan Thomas

Consider a strictly convex bounded regular domain $C$ of $\R^3$. For any arbitrary finite topological type we find a compact Riemann surface $\mathcal{M}$, an open domain $M\subset \mathcal{M}$ with the fixed topological type, and a…

Differential Geometry · Mathematics 2008-11-19 Antonio Alarcon