Spectral analysis methods theoretical aspects

The theoretical description can specifically address the various scattering processes by the development of appropriate models, which are presented in Section 6.2. In experiment, the combined effect of all scattering processes is usually observed, and only by extensive and careful analysis, the individual contributions can be disentangled. Therefore, the presentation of the experimental methods is organized according to the physical observables as listed in Table 6.1. The electron dynamics in the time domain is accessible only in time-resolved 2-PPE and is discussed in Section 6.3. Photoelectron spectroscopies as well as STS access the electron dynamics via the spectral line shape. These aspects are presented in Section 6.4. Real space imaging of electron waves is possible only in STM, which is discussed in Section 6.5. The final Section 6.6 compares the information obtained by the various experimental methods with theoretical calculations and presents the current understanding of electron dynamics at surfaces. 

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