Article
Keywords:
supporting of subsets; convex subsets (hypersurfaces); conjugate (focal) points; horospheres
Summary:
In this paper, local, global, strongly local and strongly global supportings of subsets in a complete simply connected smooth Riemannian manifold without focal points are defined. Sufficient conditions for convexity of subsets in the same sort of manifolds have been derived in terms of the above mentioned types of supportings.
References:
[1] Beltagy M.:
Foot points and convexity in manifolds without conjugate points. Bull. Calcutta Math. Soc. 82 (1990), 338-348.
MR 1134214 |
Zbl 0749.53033
[3] Bolton J.:
Tight immersion into manifolds without conjugate points. Quart. J. Math. Oxford (2) 23 (1982), 159-267.
MR 0657122
[4] Burago Yu.D., Zalgaller V.A.:
Sufficient criteria of convexity. J. Soviet Math. (10) 3 (1978), 395-435.
Zbl 0389.52001
[5] Eschenburg J.H.:
Horospheres and the stable part of the geodesic flow. Math. Z. 153 (1977), 237-251.
MR 0440605 |
Zbl 0332.53028
[7] Kelly P.J., Weiss M.L.:
Geometry and convexity. John Wiley & Sons, Inc., New York, 1979.
MR 0534615 |
Zbl 0409.52001