We study the area-minimization property of the cones over Stiefel manifolds V_(m)(F^(n))(F=R,C or H)and their products,where the Stiefel manifolds are embedded into the unit sphere of Euclidean space in a standard way...We study the area-minimization property of the cones over Stiefel manifolds V_(m)(F^(n))(F=R,C or H)and their products,where the Stiefel manifolds are embedded into the unit sphere of Euclidean space in a standard way.We will show that these cones are areaminimizing if the dimension is at least 7,using the Curvature Criterion of[Mem.Amer.Math.Soc.,1991,91(446):vi+111 pp.].This extends the results of corresponding references,where the cones over products of Grassmann manifolds were considered.展开更多
A suffcient condition for a set of calibrated submanifolds to be area-minimizing with multiplicities,also call weighted area-minimizing under diffeomorphisms (WAMD) is stated.We construct some WAMD submanifolds by ass...A suffcient condition for a set of calibrated submanifolds to be area-minimizing with multiplicities,also call weighted area-minimizing under diffeomorphisms (WAMD) is stated.We construct some WAMD submanifolds by assembling pieces of special Lagrangian (SL) normal bundles including the one of three surfaces meeting at an angle of 120° along soap-film-like singularities.We also mention a symmetry property of SL submanifolds and Bjrling type problem for SL normal bundles.展开更多
We show the area-minimality property of all homogeneous area-minimizing hypercones in Euclidean spaces （classified by Lawlor） following Lawson＇s original idea in his 72＇ Trans. A.M.S. paper ＂The equivariant Plate...We show the area-minimality property of all homogeneous area-minimizing hypercones in Euclidean spaces （classified by Lawlor） following Lawson＇s original idea in his 72＇ Trans. A.M.S. paper ＂The equivariant Plateau problem and interior regularity＂. Moreover, each of them enjoys （coflat） calibrations singular only at the origin.展开更多
In this paper,for any local area-minimizing closed hypersurface∑with RcΣ=RΣ/ngΣ,immersed in a(n+1)-dimension Riemannian manifold M which has positive scalar curvature and nonnegative Ricci curvature,we obtain an u...In this paper,for any local area-minimizing closed hypersurface∑with RcΣ=RΣ/ngΣ,immersed in a(n+1)-dimension Riemannian manifold M which has positive scalar curvature and nonnegative Ricci curvature,we obtain an upper bound for the area of∑.In particular,when∑saturates the corresponding upper bound,∑is isometric to S^(n)and M splits in a neighborhood of∑.At the end of the paper,we also give the global version of this result.展开更多
基金Supported by NSFC(No.11871450)Project of Stable Support for Youth Team in Basic Research Field,CAS(No.YSBR-001).
文摘We study the area-minimization property of the cones over Stiefel manifolds V_(m)(F^(n))(F=R,C or H)and their products,where the Stiefel manifolds are embedded into the unit sphere of Euclidean space in a standard way.We will show that these cones are areaminimizing if the dimension is at least 7,using the Curvature Criterion of[Mem.Amer.Math.Soc.,1991,91(446):vi+111 pp.].This extends the results of corresponding references,where the cones over products of Grassmann manifolds were considered.
基金supported in part by the National Foundation for Science and Technology Development,Vietnam (Grant No.101.01.30.09)
文摘A suffcient condition for a set of calibrated submanifolds to be area-minimizing with multiplicities,also call weighted area-minimizing under diffeomorphisms (WAMD) is stated.We construct some WAMD submanifolds by assembling pieces of special Lagrangian (SL) normal bundles including the one of three surfaces meeting at an angle of 120° along soap-film-like singularities.We also mention a symmetry property of SL submanifolds and Bjrling type problem for SL normal bundles.
基金Partially supported by the Fundamental Research Funds for the Central Universities,the SRF for ROCS,SEM,NSFC(Grant Nos.11526048,11601071)the NSF(Grant No.0932078 000) while the author was in residence at the MSRI during the 2013 Fall
文摘We show the area-minimality property of all homogeneous area-minimizing hypercones in Euclidean spaces （classified by Lawlor） following Lawson＇s original idea in his 72＇ Trans. A.M.S. paper ＂The equivariant Plateau problem and interior regularity＂. Moreover, each of them enjoys （coflat） calibrations singular only at the origin.
基金supported by National Science Foundation of China(11601467).
文摘In this paper,for any local area-minimizing closed hypersurface∑with RcΣ=RΣ/ngΣ,immersed in a(n+1)-dimension Riemannian manifold M which has positive scalar curvature and nonnegative Ricci curvature,we obtain an upper bound for the area of∑.In particular,when∑saturates the corresponding upper bound,∑is isometric to S^(n)and M splits in a neighborhood of∑.At the end of the paper,we also give the global version of this result.
