Positive bidiagonal factorization of tetradiagonal Hessenberg matrices

Recently, a spectral Favard theorem was presented for bounded banded lower Hessenberg matrices that possess positive bidiagonal factorization. The paper establishes conditions, expressed in terms of continued fractions, under which an oscillatory tetradiagonal matrix can have such Oscillatory Toeplitz are examined as case study admit Furthermore, the proves organized rays, where origin ray does not factorization, but all interior points do