Recent progress in EXAFS/NEXAFS spectroscopy

We briefly review the basic theory and recent applications in the X-ray absorption fine structure (XAFS) spectroscopy. First we discuss a dressed one-electron XAFS formula starting from many-body scattering theory, where important many-body effects, intrinsic and extrinsic losses, and optical potential are naturally introduced. Next multiple scattering renormalization, and spherical wave effects are discussed. Phonon effects such as Debye-Waller factors are also discussed. Some interesting XAFS applications, in particular, ultrafast XAFS and XAFS applications to nano-particles are discussed in some detail.