A physical interpretation of axioms of the differential structure of
space-time is presented. Consequences of such interpretation for cosmic
string's space-time with a scalar field are studied. It is shown that the
assumption of smoothness of the scalar field leads either to modification of
cosmic string's space-time global properties or to quantization of the deficit
of angle: Ξ=2Ο(1β1/n), n=1,2,β¦.Comment: 9 pages, LaTeX, Lecture delivered at " Workshop on Modern Methods in
Classical and Quantum Gravity ", July 26-28th, 1995, Sintra, Portuga