NONTOPOLOGICAL GLOBAL FIELD-DYNAMICS

We use arguments based on Derrick's theorem to show that the property of collapse, which is the key feature of global texture, appears in several field theory models with broken global O(N) symmetry. Such models do not necessarily have a nontrivial third homotopy group of the vacuum manifold but may give rise to collapsing global field configurations with properties similar to textures. It is verified that configurations with planar and cylindrical geometries do not collapse. The existence of critical parameters for collapse of spherically symmetric global field configurations is verified both analytically and numerically.