Tomonaga's Model and the Threshold Singularity of X-Ray Spectra of Metals

摘要: Singularities near the threshold of soft x-ray spectra metals have been predicted by Mahan and recently calculated Nozi\`eres et al. using model a localized core hole. We show that singular behavior can be understood in terms density waves conduction electrons which are excited when, absorption process, hole is created, providing an attractive potential for electrons. For description waves, Tomonaga's adopted.