Cat(0) Groups with Non-Locally Connected Boundary

The main theorem shows that whenever certain amalgamated productsact geometrically on a CAT(0) space, the space has non-locallyconnected boundary. One can now easily construct a wide varietyof examples of one-ended CAT(0) groups with non-locally connectedboundary. Applications of this theorem to right-angled Coxeterand Artin groups are considered. In particular, it is shownthat the natural CAT(0) space on which a right-angled Artingroup acts has locally connected boundary if and only if thegroup is Zⁿ for some n.