Submatrices with the best-bounded inverses: the equality criteria for $\mathds{R}^{n \times 2}$

The long-standing hypothesis formulated by Goreinov, Tyrtyshnikov and Zamarashkin \cite{GTZ1997} has been recently solved by Sengupta and Pautov \cite{SP2026} in the case of two-column matrices. In this paper, we complement their elegant proof with the equality criteria. --- Source: arXiv:2604.14050v1 - http://arxiv.org/abs/2604.14050v1 PDF: https://arxiv.org/pdf/2604.14050v1 Original Link: http://arxiv.org/abs/2604.14050v1