Gravitational analogy of Casimir-effect from QED to gravity descrip- tion in GRT

Classical GRT of Einstein-description of gravity-theory can be extrapolated to higher structures.This extension adds higher-order terms to classical general relativity because GRT itself can be as-sumed to be a first-order expansion of spacetime. These higher corrections can lead to new observa-tions in the vacuum, with gravitational waves, or black holes. Furthermore, an attempt is made totransfer the Casimir effect of quantum electrodynamics as an analogy from the electromagnetic vac-uum to a spacetime description and to describe this analogy as a gravitational effect within GRT.