Kneser's theorem (differential equations)
In mathematics, the Kneser theorem can refer to two distinct theorems in the field of ordinary differential equations: the first one, named after Adolf Kneser, provides criteria to decide whether a differential equation is oscillating or not; the other one, named after Hellmuth Kneser, is about the topology of the set of all solutions of an initial value problem with continuous right hand side. == Statement of the theorem due to A. Kneser == Consider an ordinary linear homogeneous differential equation of the form y ″ + q ( x ) y = 0 {\displaystyle y''+q(x)y=0} with q : [ 0 , + ∞ ) → R {\displaystyle q:[0,+\infty )\to \mathbb {R} } continuous.
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