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for questions about deformation theory, including deformations of manifolds, schemes, Galois representations, and von Neumann algebras.

3 votes

Deformation of (locally) ringed spaces and of their abelian categories of modules

The answer to your second question is "no", I think. Let's assume that sufficiently nice means that it is a smooth algebraic variety over a field of characteristic $0$. Then, as written in Severin Bar …
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7 votes
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Fedosov vs. Kontsevich deformation quantization : a beginner survey

Fedosov's work seems to be also available with details in a book Deformation quantization and index theory. Are the two references overlapping ? Yes, indeed. The book contains strictly more than …
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6 votes

Deformation Quantization

In addition to the references pointed out by Stefan, I would like to add Déformation, quantification, et théorie de Lie, by Catteno, Keller, and Torossian (Part I and Part III are actually in Engl …
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2 votes

Koszul algebras deformations

If, by deformation, you mean formal one-parameter deformation (like, say, in deformation quantization), then it is already known that the Koszul duality between the symmetric and the exterior algebra …
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3 votes

Non-associative deformation quantization

This is probably not really an answer to this question, but there are two different context I know where deformation quantization produces something not exactly associative, but associative in a large …
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2 votes
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Kontsevich Formality sign convention

Welcome to mathoverflow! There is actually a whole paper (in French) about choices of signs for Kontsevich formality: https://arxiv.org/pdf/math/0003003.pdf For instance, they define the Hochschild …
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3 votes

Alternative to Kontsevich formality

You might want to have a look at §2.2 of An $L_\infty$ algebra structure on polyvector fields by Boris Shoikhet, where Boris constructs an exotic $L_\infty$-structure on poly-vector fields on a (possi …
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3 votes
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Functoriality of the formality quasi-isomorphism of E-polydifferential operators

The construction is functorial with respect to algebraic morphisms of Lie algebroids (as opposed to geometric ones): see for instance my paper with Van de Bergh https://arxiv.org/pdf/0708.2725.pdf (it …
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2 votes

What's the relation between the heat kernel proof of the index theorem and deformation quant...

I think you should have a look at the various papers of Louis Boutet de Monvel. But there is actually a construction of star-products on a symplectic manifold which makes use of the index theorem, due …
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8 votes
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Does the vanishing of the Poisson bracket on $S(\mathfrak{g})^{\mathfrak{g}}$ inspire the di...

My question is: Does the vanishing of the Poisson bracket plays an important role in finding and proving Duflo's isomorphism theorem? Or it is just an literally first step? Let $A_0$ be a …
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6 votes

How to define the equivalence of Maurer-Cartan elements in an $L_{\infty}$-algebra?

This is explained in Section 4.5.2 of "deformation quantization of poisson manifolds" by Kontsevich (http://arxiv.org/abs/q-alg/9709040). The way you wrote the homotopy between two Maurer-Cartan ele …
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3 votes
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What is the definition of "the $L_\infty$ part of a $G_\infty$ morphism"?

A $G_\infty$-morphism $\phi$ is determined by structure maps $\phi^{k_1,\dots,k_n}$, $n\geq1$, $k_1,\dots,k_n\geq1$. The $L_\infty$-part of $\phi$ is the $L_\infty$-morphism $\ell$ with structure ma …
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4 votes

Tamarkin-Tsygan Formalism

Here is a sketch of topological description of a Tamarkin-Tsygan precalculus. Consider the compactified configuration spaces $C_n$ and $D_{1,n}$ of $n$ points on $\mathbb{R}^2$ and $\mathbb{R}^2-\{( …
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17 votes
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A matrix algebra has no deformations?

Deformation of relations Answer to question 2 is the following: a deformation of an algebra $A_0$ parametrized by a pointed affine scheme $*\to X=Spec(B\to k)$ is the data of a $B$-algebra $A$ such t …
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5 votes

Kontsevich's formality theorem from an explicit homotopy

The only way I know to construct a formality quasi-morphism for poy-vector fields out of an homotopy is via Tamarkins approach (i.e. $G_\infty$-formality). What Tamrakin does is prove that there is …
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