nichtverschwindende
Nichtverschwindende is a German term meaning non-vanishing or persistent. In German-language texts it is used to describe quantities, functions, or objects that do not disappear or reduce to zero under specified conditions. The expression can serve as an adjective, as in nichtverschwindende Funktionen, or as a nominalized form like die Nichtverschwindenden, depending on context and grammar.
In mathematics the closest standardized notion is nowehre vanishing. A function f on a domain is nowhere
In physics and engineering, a related usage describes quantities that persist without decay under the dynamics
Usage notes: Nichtverschwindende is primarily a German-language term and is not a universally standardized technical term