▎ 摘　　要

We calculate the x-ray absorption spectra (XAS) for 1s-pi* and 1s-sigma* transitions in single layer graphene using the dipole approximation and we compare with experimental results. It is found that the in-plane and out-of-plane orientations of the dipole vectors, which correspond to the 1s-pi* and 1s-sigma* transitions, respectively, are responsible for the polarization dependence of the x-ray absorption intensity in graphene. Using the atomic matrix elements, the low-energy XAS peaks can be assigned.