A new method of extracting electron-boson spectral function α^2F(ω) from infrared and ARPES spectra using inverse theory

We will present a new method of extracting electron-boson spectral function α^2F(ω) from infrared and ARPES spectra. Numerical implementation of the method will be illustrated and then used to accurately determine the doping and temperature dependence of α^2F(ω) in several families of high-T_c superconductors. We will discuss the nature of the resonance mode in the α^2F(ω) spectra in terms of existing theoretical models (spin-fluctuations vs. phonons).