Spacetime Defects: von Kármán vortex street like configurations

A special arrangement of spinning strings with dislocations similar to a von Kármán vortex street is studied. We numerically solve the geodesic equations for the special case of a test particle moving along two infinite rows of pure dislocations and also discuss the case of pure spinning defects. PACS numbers: 04.20 Jb, 04.50.+h, 11.10.Lm, 47.32.Cc Conical singularities or spacetime defects are characterized by RiemannChristoffel curvature tensor, or Cartan torsion, or both different from zero only on the subspace (event, world line, world sheet, or world tube) that describes the evolution of the defect (texture, monopole, string, or membrane). In other words we have that the curvature, the torsion, or both, are proportional to distributions with support on the defect. Spacetimes with conical singularities of different types has been studied recently in a variety of contexts, e.g. spinning strings with cosmic dislocations [1][2], pure spacetime dislocations [3]– [5], also in low dimensional gravity [6]. For the discussion of a great variety of defects see Ref. [7]. Some quantum aspects related to line defects has been considered by several authors: The spectra of a quantum particle in the presence of e-mail: [email protected]