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119
Deformations of algebras over operads and the Deligne conjecture, Conférence Moshé Flato
, 1999
"... The deformation theory of associative algebras is a guide for developing the deformation theory of many algebraic structures. Conversely, all the ..."
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Cited by 112 (6 self)
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The deformation theory of associative algebras is a guide for developing the deformation theory of many algebraic structures. Conversely, all the
A short survey of noncommutative geometry
 J. Math. Physics
, 2000
"... We give a survey of selected topics in noncommutative geometry, with some emphasis on those directly related to physics, including our recent work with Dirk Kreimer on renormalization and the RiemannHilbert problem. We discuss at length two issues. The first is the relevance of the paradigm of geom ..."
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Cited by 45 (3 self)
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We give a survey of selected topics in noncommutative geometry, with some emphasis on those directly related to physics, including our recent work with Dirk Kreimer on renormalization and the RiemannHilbert problem. We discuss at length two issues. The first is the relevance of the paradigm of geometric space, based on spectral considerations, which is central in the theory. As a simple illustration of the spectral formulation of geometry in the ordinary commutative case, we give a polynomial equation for geometries on the four dimensional sphere with fixed volume. The equation involves an idempotent e, playing the role of the instanton, and the Dirac operator D. It expresses the gamma five matrix as the pairing between the operator theoretic chern characters of e and D. It is of degree five in the idempotent and four in the Dirac operator which only appears through its commutant with the idempotent. It determines both the sphere and all its metrics with fixed volume form. We also show using the noncommutative analogue of the Polyakov action, how to obtain the noncommutative metric (in spectral form) on the noncommutative tori from the formal naive metric. We conclude on some questions related to string theory. I
Perturbative 3manifolds invariants by cutandpaste topology
, 1999
"... We give a purely topological definition of the perturbative quantum invariants of links and 3manifolds associated with ChernSimons field theory. Our definition is as close as possible to one given by Kontsevich. We will also establish some basic properties of these invariants, in particular that t ..."
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Cited by 36 (1 self)
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We give a purely topological definition of the perturbative quantum invariants of links and 3manifolds associated with ChernSimons field theory. Our definition is as close as possible to one given by Kontsevich. We will also establish some basic properties of these invariants, in particular that they are universally finite type with respect to algebraically split surgery and with respect to Torelli surgery. Torelli surgery is a mutual generalization of blink surgery of Garoufalidis and Levine and clasper surgery of Habiro.
The EckmannHilton argument, higher operads and Enspaces, available at http://www.ics.mq.edu.au
 mbatanin/papers.html of Homotopy and Related Structures
"... The classical EckmannHilton argument shows that two monoid structures on a set, such that one is a homomorphism for the other, coincide and, moreover, the resulting monoid is commutative. This argument immediately gives a proof of the commutativity of the higher homotopy groups. A reformulation of ..."
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Cited by 32 (5 self)
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The classical EckmannHilton argument shows that two monoid structures on a set, such that one is a homomorphism for the other, coincide and, moreover, the resulting monoid is commutative. This argument immediately gives a proof of the commutativity of the higher homotopy groups. A reformulation of this argument in the language of higher categories is: suppose we have a one object, one arrow 2category, then its Homset is a commutative monoid. A similar argument due to A.Joyal and R.Street shows that a one object, one arrow tricategory is ‘the same’ as a braided monoidal category. In this paper we extend this argument to arbitrary dimension. We demonstrate that for an noperad A in the author’s sense there exists a symmetric operad S n (A) called the nfold suspension of A such that the
Multivariable cochain operations and little ncubes
 J. Amer. Math. Soc
"... Abstract. In this paper we construct a small E ∞ chain operad S which acts naturally on the normalized cochains S ∗ X of a topological space. We also construct, for each n, a suboperad Sn which is quasiisomorphic to the normalized singular chains of the little ncubes operad. The case n = 2 leads t ..."
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Cited by 26 (1 self)
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Abstract. In this paper we construct a small E ∞ chain operad S which acts naturally on the normalized cochains S ∗ X of a topological space. We also construct, for each n, a suboperad Sn which is quasiisomorphic to the normalized singular chains of the little ncubes operad. The case n = 2 leads to a substantial simplification of our earlier proof of Deligne’s Hochschild cohomology conjecture. 1. Introduction. This paper has two goals. The first (see Theorem 2.15 and Remark 2.16(a)) is to construct a small E ∞ chain operad S which acts naturally on the normalized cochains S∗X of a topological space X. This is of interest in view of a theorem of Mandell [15, page 44] which states that if O is any E ∞ chain operad over Fp (the algebraic closure of the field with
Multiple ζvalues, Galois groups, and geometry of modular varieties
, 2000
"... We discuss two arithmetical problems, at first glance unrelated: 1) The properties of the multiple ζvalues ζ(n1,..., nm):= ∑ 1 nm> 1 (1) ..."
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Cited by 25 (6 self)
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We discuss two arithmetical problems, at first glance unrelated: 1) The properties of the multiple ζvalues ζ(n1,..., nm):= ∑ 1 nm> 1 (1)
Operads and knot spaces
 J. Amer. Math. Soc
"... Let Em denote the space of embeddings of the interval I = [−1, 1] in the cube I m with endpoints and tangent vectors at those endpoints fixed on opposite faces of the cube, equipped with a homotopy through immersions to the unknot – see Definition 5.1. By Proposition 5.17, Em is homotopy equivalent ..."
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Cited by 24 (2 self)
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Let Em denote the space of embeddings of the interval I = [−1, 1] in the cube I m with endpoints and tangent vectors at those endpoints fixed on opposite faces of the cube, equipped with a homotopy through immersions to the unknot – see Definition 5.1. By Proposition 5.17, Em is homotopy equivalent to Emb(I, I m) × ΩImm(I, I m). In [28], McClure and Smith define a cosimplicial object O • associated
Renormalization and motivic Galois theory
 International Math. Research Notices
"... Abstract. We investigate the nature of divergences in quantum field theory, showing that they are organized in the structure of a certain “ motivic Galois group ” U ∗ , which is uniquely determined and universal with respect to the set of physical theories. The renormalization group can be identifie ..."
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Cited by 24 (12 self)
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Abstract. We investigate the nature of divergences in quantum field theory, showing that they are organized in the structure of a certain “ motivic Galois group ” U ∗ , which is uniquely determined and universal with respect to the set of physical theories. The renormalization group can be identified canonically with a one parameter subgroup of U ∗. The group U ∗ arises through a Riemann–Hilbert correspondence. Its representations classify equisingular flat vector bundles, where the equisingularity condition is a geometric formulation of the fact that in quantum field theory the counterterms are independent of the choice of a unit of mass. As an algebraic group scheme, U ∗ is a semidirect product by the multiplicative group Gm of a prounipotent group scheme whose Lie algebra is freely generated by one generator in each positive integer degree. There is a universal singular frame in which all divergences disappear. When computed as iterated integrals, its coefficients are certain rational numbers that appear in the local index formula of Connes–Moscovici. When working with formal Laurent series over Q, the data of equisingular flat vector bundles