Vanishing prefactor at one time does not ensure a uniform Lipschitz bound

ID: vanishing-prefactor-at-one-time-does-not-ensure-a-uniform-lipschitz-bound

A coefficient that vanishes at the initial time can hide failure of the uniform Lipschitz condition required for an initial value problem. For , the map is identically zero. But every rectangle of positive widths around contains some , and
No Lipschitz constant works uniformly on the rectangle. Actual uniqueness also fails: and are distinct differentiable solutions with initial value zero. Substitution gives for the second solution. A condition at the single initial time cannot replace control on a neighbourhood.

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