Some Remarks on the Titchmarsh-Weyl m-Coeffìcient and Associated Differential Operators

The Titchmarsh-Wey1 m-coefficient for second-order ordinary differential equations was first introduced by Titchmarsh in 1941, see [21], but based on the fundamental work of Weyl in 1910, see [23]. For some discussion on the history of the m-coefficient see Bennewitz, Everitt [5, Section 1], and Fulton [16].