Hochschild and cotangent complexes of operadic algebras

Abstract

We make use of the cotangent complex formalism developed by Lurie to formulate Quillen cohomology of algebras over an enriched operad. Additionally, we introduce a spectral Hochschild cohomology theory for enriched operads and algebras over them. We prove that both the Quillen and Hochschild cohomologies of algebras over an operad can be controlled by the corresponding cohomologies of the operad itself. When passing to the category of simplicial sets, we assert that both these cohomology theories for operads, as well as their associated algebras, can be calculated in the same framework of spectrum valued functors on the twisted arrow $\infty$-category of the operad of interest. Moreover, we provide a convenient cofiber sequence relating the Hochschild and cotangent complexes of an $E_n$-space, establishing an unstable analogue of a significant result obtained by Francis and Lurie. Our strategy introduces a novel perspective, focusing solely on the intrinsic properties of the operadic twisted arrow $\infty$-categories.