Morse function

Named after Marston Morse.

Morse function (plural Morse functions)

1. A real-valued function on a differentiable manifold such that, at each point in its domain where the function's differential is zero, the function's Hessian is nonsingular.

• Some sources require also for each ${\displaystyle t\in \mathbb {R} }$ that the preimage of ${\displaystyle \left(-\infty ,t\right)}$ be compact, or that the preimage of ${\displaystyle t}$ contain at most one point with zero differential.

• Morse function on Wikipedia.Wikipedia