On the order theory for $\mathcal{C}^\infty$-reduced $\mathcal{C}^\infty$-Rings and applications

Abstract: In the present work we carry on the study of the order theory for ($\mathcal{C}^{\infty}-$-reduced) $\mathcal{C}^{\infty}-$-rings initiated in \cite{rings1} (see also \cite{BM2}). In particular, we apply some results of the order theory of $\mathcal{C}^{\infty}-$-fields (e.g., every such field is real closed) to present another approach to the order theory of general $\mathcal{C}^{\infty}-$-rings: "smooth real spectra" (see \cite{separation}). This suggests that a model-theoretic investigation of the class of $\mathcal{C}^{\infty}-$-fields could be interesting and also useful to provide the first steps towards the development of the "Real Algebraic Geometry" of $\mathcal{C}^{\infty}-$-rings.