Přehled o publikaci

Axisymmetric string loops oscillating around a stable equilibrium position in the Kerr background are applied to explain the special set of frequencies related to the high-frequency quasiperiodic oscillations observed in the low mass X-ray binary XTE J1701-462 containing a neutron star. Frequencies of the radial and vertical string loop oscillations are determined by the mass M and dimensionless spin a of the neutron star, and by dimensionless parameter ! describing combined effects of the string loop tension and its angular momentum. Equilibrium position of the string loop is given by its angular momentum and energy. The string-loop oscillation model can explain the observed kHz frequencies, but the stringy parameter ! cannot be the same for all the three HF QPO observations in the XTE J1701-462 source; the limits on the acceptable values of ! are given in dependence on the spacetime parameters M and a. However, the model implies restriction M > 3.3M_{sun} on the neutron star mass tha