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In this paper we consider Quadratic Gravity as a low energy effective fieldtheory of some unknown UV-complete theory of gravity. Using the spin-2 ghostpathology that occurs in Quadratic Gravity, we derive maximum value for theclassical cut-off of the low energy effective field theory in variousconfigurations. We then add on higher order, bottom-up, effective terms. Ateach order we allow the introduction of non-minimally coupled scalar fieldterms, and we calculate the vacuum expectation value of the theory under anassumed $\mathbb{Z}_2$ symmetry breaking of the scalar field. This symmetrybreaking leads us to introduce a constant in the action which is required toensure that the physical spin-2 degree of freedom is massless in the flat spaceapproximation, an implicit assumption we make throughout the work. We thenconsider the case in which we do not fine tune the introduced constant, whichleads to an (Anti-)de Sitter solution about which we can then expand. The signof the chosen cosmological constant is the major factor in determining whetherthe geometry is de Sitter or Anti-de Sitter. Then expanding about this geometryallows us to increase the theoretical classical cut-off as compared to the flatspace case by an amount that is proportional to the free cosmological constantparameter.

Effective Non-Minimal Quadratic Gravity and the Classical Cut-Off