Tunneling spectroscopy of Bi2Sr2CaCu2O8+delta: Eliashberg analysis of the spectral dip feature

Eliashberg strong-coupling theory, extended to a d-wave symmetric gap function, is used to fit quantitatively a published tunneling spectrum of Bi2Sr2CaCu2O8+delta near optimal doping. The shape, location, and strength of the high-bias spectral dip feature is adequately reproduced using a single-peak alpha(2)F(omega) centered at 36.5 meV. alpha(2)F(omega) also self-consistently determines the measured gap value Delta=32 meV. Possible origins of the bosonic spectrum that give rise to high-T-C superconductivity are discussed.