Disclinations and Topological Point Defects. Fluid Relaxation.

Dislocations in crystalline solids are rather simple examples of topological singularities: The symmetry of translation is broken along a line, and the Burgers vectors of merging dislocations add up linearly; on the other hand, they are complex physical objects, whose most important properties relate to irreversible phenomena that attend plastic deformation. [ABSTRACT FROM AUTHOR]