Extrinsic geometry sensitive bosonic string theory (Q1918719)

The ``rigid'' bosonic string is defined by an action that contains besides the Nambu-Goto term also a term (with coupling constant \(\alpha_0\)) proportional to the square of the extrinsic curvature tensor of the worldsheet [\textit{A. M. Polyakov}, Nucl. Phys. B 268, No. 2, 406-412 (1986)]. The author generalizes this action by adding a Wess-Zumino term to it, computes the beta function for \(\alpha_0\) in the one-loop approximation, and obtains an infrared stable fixed point, implying conformal invariance.