Lie models of homotopy automorphism monoids and classifying fibrations (2103.06543v2)

Abstract: Given $X$ a finite nilpotent simplicial set, consider the classifying fibrations $$ X\to Baut_G^*(X)\to Baut_G(X),\qquad X\to Z\to Baut_{\pi}^*(X), $$ where $G$ and $\pi$ denote, respectively, subgroups of the free and pointed homotopy classes of free and pointed self homotopy equivalences of $X$ which act nilpotently on $H_(X)$ and $\pi_(X)$. We give algebraic models, in terms of complete differential graded Lie algebras (cdgl's), of the rational homotopy type of these fibrations. Explicitly, if $L$ is a cdgl model of $X$, there are connected sub cdgl's $Der^G L$ and $Der^{\pi} L$ of the Lie algebra $Der L$ of derivations of $L$ such that the geometrical realization of the sequences of cdgl morphisms $$ L\stackrel{ad}{\to} Der^G L\to Der^G L\widetilde\times sL,\qquad L\to L\widetilde\times Der^{\pi} L\to Der^{\pi} L $$ have the rational homotopy type of the above classifying fibrations. Among the consequences we also describe in cdgl terms the Malcev $Q$-completion of $G$ and $\pi$ together with the rational homotopy type of the classifying spaces $BG $ and $B\pi$.