The files
<Spectra>/include/LinAlg/TridiagEigen.h<Spectra>/include/LinAlg/UpperHessenbergEigen.h
were adapted from
Eigen/src/Eigenvaleus/SelfAdjointEigenSolver.hEigen/src/Eigenvaleus/EigenSolver.h
in the Eigen library.
The authors for these two files were Gael Guennebaud [email protected] and Jitse Niesen [email protected].
The Catch library included for unit testing was written by Phil Nash [email protected].
Other part of Spectra was written by Yixuan Qiu [email protected].