Observational constraints on cosmological superstrings
  From theoretical point of view and not being in contradiction with current observational data, the cosmic strings should have fundamentally different origin and are characterized by wide range of energies. The paper is devoted to search for possible cosmological observational tests on superstring theory, among them to identification of observational characteristics to distinguish between cosmological superstring of different types. In the brane-world scenario with an assumption of creation of cosmological superstrings it was obtained the lower limit on the superstring tension as function of deficit angle. 
Olga S. Sazhina and Alfiia I. Mukhaeva
astro-ph.CO gr-qc