定义并研究deSitter空间中的线性Weingarten类空超曲面,得到类空超曲面是全脐的一些充分条件。即1)设M是deSitter空间S1^n+1(1)中的n维紧致类空超曲面,且M具有正截曲率。若存在常数a,b使得r=aH+b,且(n-1)a^2+4n-4nb≥10,其中r和H分别为M的标准数量曲率及平均曲率。则M是全脐的。2)设M是deSitter空间S1^n+1(1)中的n维紧致类空超曲面,若存在常数a,b使得r=aH+b,且(n-1)a^2+4n-4nb≥10。那么当IBI。〈2√n-1时,M必然是全脐超曲面。
The linear Weingarten-type spacelike hypersurfaces in a de Sitter space is defined and studied. Some sufficient conditions for this spacelike hypersurfaces to be totally umbilical ones are obtained, that is : ( 1 ) Let M be an n -dimensional compact spacelike hypersurface with positive sectional curvature in a de Sitter space S1^n+1 if the normalized scalar curvature r and the mean curvature H satisfy r =aH + b and ( n - 1 ) a2 + 4n - 4nb 〉10, then M is umbilical; and (2) Let M be an n - dimensional compact spacelike hypersurfaces in a de Sitter space S1^N+ 1, if r and H satisfy r=aH+b,(n-1)a2 +4n -4nb≥0, and |B|^2 〈2√n-1, then M is umbilical.