In this paper we present background results in enriched category theory and enriched model category theory necessary for developing model categories of enriched functors suitable for doing functor calculus.
We study a connection between mapping spaces of bimodules and of infinitesimal bimodules over an operad. As main application and motivation of our work, we produce an explicit delooping of the manifold calculus tower associated to the space of smooth
maps $D^{m}rightarrow D^{n}$ of discs, $ngeq m$, avoiding any given multisingularity and coinciding with the standard inclusion near $partial D^{m}$. In particular, we give a new proof of the delooping of the space of disc embeddings in terms of little discs operads maps with the advantage that it can be applied to more general mapping spaces.
There exists a canonical functor from the category of fibrant objects of a model category modulo cylinder homotopy to its homotopy category. We show that this functor is faithful under certain conditions, but not in general.
Let $mathcal{A}$ be a small abelian category. The purpose of this paper is to introduce and study a category $overline{mathcal{A}}$ which implicitly appears in construction of some TQFTs where $overline{mathcal{A}}$ is determined by $mathcal{A}$. If
$mathcal{A}$ is the category of abelian groups, then the TQFTs obtained by Dijkgraaf-Witten theory of abelian groups or Turaev-Viro theory of bicommutative Hopf algebras factor through $overline{mathcal{A}}$ up to a scaling. In this paper, we go further by giving a sufficient condition for an $mathcal{A}$-valued Brown functor to extend to a homotopy-theoretic analogue of $overline{mathcal{A}}$-valued TQFT for arbitrary $mathcal{A}$. The results of this paper and our subsequent paper reproduces TQFTs obtained by DW theory and TV theory.
We develop a theory of Frobenius functors for symmetric tensor categories (STC) $mathcal{C}$ over a field $bf k$ of characteristic $p$, and give its applications to classification of such categories. Namely, we define a twisted-linear symmetric monoi
dal functor $F: mathcal{C}to mathcal{C}boxtimes {rm Ver}_p$, where ${rm Ver}_p$ is the Verlinde category (the semisimplification of ${rm Rep}_{bf k}(mathbb{Z}/p)$). This generalizes the usual Frobenius twist functor in modular representation theory and also one defined in arXiv:1503.01492, where it is used to show that if $mathcal{C}$ is finite and semisimple then it admits a fiber functor to ${rm Ver}_p$. The main new feature is that when $mathcal{C}$ is not semisimple, $F$ need not be left or right exact, and in fact this lack of exactness is the main obstruction to the existence of a fiber functor $mathcal{C}to {rm Ver}_p$. We show, however, that there is a 6-periodic long exact sequence which is a replacement for the exactness of $F$, and use it to show that for categories with finitely many simple objects $F$ does not increase the Frobenius-Perron dimension. We also define the notion of a Frobenius exact category, which is a STC on which $F$ is exact, and define the canonical maximal Frobenius exact subcategory $mathcal{C}_{rm ex}$ inside any STC $mathcal{C}$ with finitely many simple objects. Namely, this is the subcategory of all objects whose Frobenius-Perron dimension is preserved by $F$. We prove that a finite STC is Frobenius exact if and only if it admits a (necessarily unique) fiber functor to ${rm Ver}_p$. We also show that a sufficiently large power of $F$ lands in $mathcal{C}_{rm ex}$. Also, in characteristic 2 we introduce a slightly weaker notion of an almost Frobenius exact category and show that a STC with Chevalley property is (almost) Frobenius exact.
We prove a rectification theorem for enriched infinity-categories: If V is a nice monoidal model category, we show that the homotopy theory of infinity-categories enriched in V is equivalent to the familiar homotopy theory of categories strictly enri
ched in V. It follows, for example, that infinity-categories enriched in spectra or chain complexes are equivalent to spectral categories and dg-categories. A similar method gives a comparison result for enriched Segal categories, which implies that the homotopy theories of n-categories and (infinity,n)-categories defined by iterated infinity-categorical enrichment are equivalent to those of more familia