Spectral singularities in one-dimensional electron liquids

Low-energy characteristics of one-dimensional electron systems are studied theoretically in terms of the power-law singularities in optical spectra. Respective roles of the many-body excitonic correlation and the infrared catastrophe are clarified in their optical responses to reveal the Tomonaga-Luttinger liquid behaviors. Critical exponents in edge spectra of valence-band photoemission, core-level photoemission, and one-photon absorption processes are found to reflect different aspects of low-energy critical properties