Intersection of sets with n-connected unions
Horvath, Charles, ; Lassonde, Marc
HAL, hal-00699217 / Harvested from HAL
We show that if n sets in a topological space are given so that all the sets are closed or all are open, and for each k ≤ n every k of the sets have a (k − 2)-connected union, then the n sets have a point in common. As a consequence, we obtain the following starshaped version of Helly's theorem: If every n + 1 or fewer members of a finite family of closed sets in Rn have a starshaped union, then all the members of the family have a point in common. The proof relies on a topological KKM-type intersection theorem.
Publié le : 1997-07-05
Classification:  [MATH.MATH-FA]Mathematics [math]/Functional Analysis [math.FA],  [MATH.MATH-GN]Mathematics [math]/General Topology [math.GN]
@article{hal-00699217,
     author = {Horvath, Charles,  and Lassonde, Marc},
     title = {Intersection of sets with n-connected unions},
     journal = {HAL},
     volume = {1997},
     number = {0},
     year = {1997},
     language = {en},
     url = {http://dml.mathdoc.fr/item/hal-00699217}
}
Horvath, Charles, ; Lassonde, Marc. Intersection of sets with n-connected unions. HAL, Tome 1997 (1997) no. 0, . http://gdmltest.u-ga.fr/item/hal-00699217/