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Related papers: The intrinsic formality of $E_n$-operads

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In this paper, we prove that the group of homotopy automorphisms of the profinite completion of the operad of little $2$-disks is isomorphic to the profinite Grothendieck-Teichm\"uller group. In particular, the absolute Galois group of…

Algebraic Topology · Mathematics 2015-06-01 Geoffroy Horel

This paper is dedicated to the memory of Moshe Flato, and will appear in Lett. Math. Phys. 48 (1) It became clear during last 5-6 years that the algebraic world of associative algebras (abelian categories, triangulated categories, etc) has…

Quantum Algebra · Mathematics 2011-05-05 Maxim Kontsevich

We use Galois group actions on \'etale cohomology to prove results of formality for dg-operads and dg-algebras with torsion coefficients. Our theory applies, among other related constructions, to the dg-operad of singular chains on the…

Algebraic Topology · Mathematics 2025-08-05 Joana Cirici , Geoffroy Horel

The framed n-discs operad fD_n is studied as semidirect product of SO(n) and the little n-discs operad. Our equivariant recognition principle says that a grouplike space acted on by fD_n is equivalent to the n-fold loop space on a…

Algebraic Topology · Mathematics 2007-05-23 Paolo Salvatore , Nathalie Wahl

We study differential graded operads and $p$-adic stable homotopy theory. We first construct a new class of differential graded operads, which we call the stable operads. These operads are, in a particular sense, stabilizations of…

Algebraic Topology · Mathematics 2025-06-19 Montek Singh Gill

In this paper we introduce the notion of Poincar\'e DGCAs of Hodge type, which is a subclass of Poincar\'e DGCAs encompassing the de Rham algebras of closed orientable manifolds. Then we introduce the notion of the small algebra and the…

Differential Geometry · Mathematics 2023-05-30 Domenico Fiorenza , Kotaro Kawai , Hông Vân Lê , Lorenz Schwachhöfer

The category of differential graded operads is a cofibrantly generated model category and as such inherits simplicial mapping spaces. The vertices of an operad mapping space are just operad morphisms. The 1-simplices represent homotopies…

Algebraic Topology · Mathematics 2017-04-06 Benoit Fresse

We study the action of the orthogonal group on the little $n$-disks operads. As an application we provide small models (over the reals) for the framed little $n$-disks operads. It follows in particular that the framed little $n$-disks…

Quantum Algebra · Mathematics 2025-09-16 Anton Khoroshkin , Thomas Willwacher

It is shown that the operad maps $E_n\to E_{n+k}$ are formal over the reals for $k\geq 2$ and non-formal for $k=1$. Furthermore we compute the cohomology of the deformation complex of the operad maps $E_{n}\to E_{n+1}$, proving an algebraic…

Quantum Algebra · Mathematics 2015-03-23 Victor Tourtchine , Thomas Willwacher

We calculate the rational cohomology of the classifying space of the diffeomorphism group of the manifolds $U_{g,1}^n:= \#^g(S^n \times S^{n+1})\setminus \mathrm{int}{D^{2n+1}}$, for large $g$ and $n$, up to approximately degree $n$. The…

Algebraic Topology · Mathematics 2024-02-21 Johannes Ebert , Jens Reinhold

In this expository paper we give an elementary, hands-on computation of the homology of the little disks operad, showing that the homology of a $d-fold loop space is a Poisson algebra. One aim is to familiarize a greater audience with…

Algebraic Topology · Mathematics 2010-02-20 Dev Sinha

An operad (this paper deals with non-symmetric operads)may be conceived as a partial algebra with a family of insertion operations, Gerstenhaber's circle-i products, which satisfy two kinds of associativity, one of them involving…

Category Theory · Mathematics 2015-07-01 Kosta DOSEN , Zoran Petric

In this work we present an explicit operad morphism that is also a homotopy equivalence between the operad given by the real Fulton MacPherson compactification of configuration spaces and the little $n$-disks operad. In particular, the…

Algebraic Topology · Mathematics 2011-10-17 Eduardo Hoefel

In this paper, we prove that there is a canonical homotopy $(n+1)$-algebra structure on the shifted operadic deformation complex $Def(e_n\to\mathcal{P})[-n]$ for any operad $\mathcal{P}$ and a map of operads $f\colon e_n\to\mathcal{P}$.…

Quantum Algebra · Mathematics 2018-10-16 Boris Shoikhet

We give a new proof of formality of the operad of little disks. The proof makes use of an operadic version of a simple formality criterion for commutative differential graded algebras due to Sullivan. We see that formality is a direct…

Algebraic Topology · Mathematics 2014-09-25 Dan Petersen

We study P-Hopf algebras with one coassociative cooperation over different operads P. For example, we consider the Loday-Ronco dendriform Hopf algebra and its isomorphisms with the noncommutative planar Connes-Kreimer Hopf algebra and with…

Rings and Algebras · Mathematics 2016-09-07 Ralf Holtkamp

We study the structure of the formal groups associated to the Morava $K$-theories of integral Eilenberg-Mac Lane spaces. The main result is that every formal group in the collection $\{K(n)^*K({\mathbb Z}, q), q=2,3,...\}$ for a fixed $n$…

Algebraic Topology · Mathematics 2014-10-01 Victor Buchstaber , Andrey Lazarev

We show that Kontsevich's formality of the little disk operad, obtained using graphs, is homotopic to Tamarkin's formality, for a special choice of a Drinfeld associator. The associator is given by parallel transport of the…

Quantum Algebra · Mathematics 2019-12-19 Pavol Severa , Thomas Willwacher

We first show the closure of the minimal nilpotent adjoint orbit Omin^{D_n} in so_{2n} is isomorphic to the affinization of T^*(SL_{n-1}/[P,P]) where P is the parabolic subgroup P_{(1,1,n-3)} of SL_{n-1}(C). Then we prove that the closure…

Representation Theory · Mathematics 2025-01-23 Boming Jia

We study the Eckmann-Hilton dual of the little disks algebra structure on iterated loop spaces: With the right definitions, every $n$-fold suspension is a coalgebra over the little $n$-disks operad. This structure induces non-trivial…

Algebraic Topology · Mathematics 2019-09-25 José M. Moreno-Fernández , Felix Wierstra