Extended dx2-y2-wave gap anisotropy in three model theories of high-Tc superconductivity

Recent experimental results have evidenced a remarkable structure in the k-dependence of the d-wave superconducting order parameter of underdoped high-T-c cuprates near a node. Here, it is pointed out that deviations from a simple d-wave superconducting spectrum induce corrections to the superconducting DOS and the low-T asymptotic behavior of various electronic properties in the superconducting state at intermediate energies. Such corrections depend on the theoretical scheme employed to describe the deviations.