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Questions tagged [differential-graded-algebras]

6 votes
0 answers
115 views

What is the DGLA controlling deformations of a group representation?

Fix a (discrete) group $G$, characteristic zero field $k$ and representation $\rho_0: G \to \mathrm{GL}_n(k)$. I want to consider the formal deformations of $\rho_0$. My understanding is there is a ...
affy's user avatar
  • 61
4 votes
0 answers
113 views

Minimal Model for $\mathbb{CP}^2 \# \mathbb{CP}^2 \# \mathbb{CP}^2$

I'm a grad student studying non-negative curvature on simply-connected manifolds and the conjectured relationship with rational homotopy theory. The rational homotopy groups (and so the number of ...
Russ Phelan's user avatar
5 votes
1 answer
420 views

Does coproduct preserve cohomology in differential graded algebra category

Consider two cochain DGA (differential graded algebras) named $A$ and $B$. By "coproduct" of two DGA I mean the category theory coproduct, not the coalgebra coproduct. It is defined in "...
wer's user avatar
  • 159
6 votes
2 answers
485 views

Is the exterior algebra intrinsically formal?

Following 4.6 and 4.7 of this paper by Seidel and Thomas, a graded algebra $A$ is called intrinsically formal if any two dgas with cohomology $A$ are quasi-isomorphic. There is a sufficient condition ...
Faniel's user avatar
  • 653
2 votes
0 answers
151 views

Resolutions of semi free (or almost free) commutative dg algebras with finitely generated cohomology

Let $A^{\bullet}:=\{ \cdots \rightarrow A^i \overset{d^i}{\rightarrow} A^{i+1} \rightarrow \cdots \rightarrow A^{-1} \rightarrow A^0 \rightarrow 0 \rightarrow \cdots \}$ be a non-positively graded ...
Walterfield's user avatar
3 votes
0 answers
121 views

proper smooth dg-categories and colimit

Let $I$ be a filtered category and $\{k_i\}_{i\in I}$ be a system of commutative rings over $I$. Toen proved that there is an equivalence of categories $$ \text{Colim}-\otimes^{\mathbb{L}}_{k_i} k:\...
OOOOOO's user avatar
  • 349
4 votes
1 answer
136 views

DG algebra structure on minimal free resolution of modules over regular local ring

Let $(Q, \mathfrak n, k)$ be a regular local ring. Let $I\subseteq \mathfrak n^2$ be an ideal, and fix a minimal generating set $\mathbb f= f_1,\cdots, f_n$ of $I$. The Koszul complex $E:= Q[e_1,...,...
uno's user avatar
  • 280
5 votes
0 answers
280 views

Serre subcategories of the category of chain complexes of modules

Let $k$ be an algebraically closed field of characteristic $0$. Let $R$ be a commutative $k$-algebra. We denote by $\operatorname{Mod}(R), C(R), $ and $ D(R)$ the category of $R$-modules, the category ...
Walterfield's user avatar
5 votes
1 answer
205 views

Equivalences of categories of complexes of modules

Let $k$ be an algebraically closed field of characteristic $0$. Let $R, S$ be two commutative $k$-algebras. Let $\operatorname{Ch}(R), \operatorname{Ch}(S)$ be the categories of complexes of $R$-...
Walterfield's user avatar
2 votes
0 answers
102 views

Differential graded modules and the Serre-Swan theorem

I am thinking about how connections combine with a modification of the Serre-Swan theorem, which relates vector bundles to projective modules. If $E \rightarrow B$ is a vector bundle, or even just any ...
user avatar
10 votes
0 answers
485 views

Reconstruction of commutative differential graded algebras

Let $k$ be an algebraically closed field of characteristic $0$. Let $A,B$ be commutative differential graded algebras (cdga) over $k$ such that $H^{i}(A)=H^{i}(B) =0 \ (i>0)$. Here, differentials ...
Walterfield's user avatar
3 votes
2 answers
293 views

Lie's third theorem via graded geometry

Lie's third theorem : Given any finite dimensional Lie algebra $\mathfrak{g}$, there exists a Lie group $G$ whose Lie algebra is equal to $\mathfrak{g}$. In one of the talks, speaker mentions that ...
Praphulla Koushik's user avatar
1 vote
0 answers
66 views

Twisting a graded algebra by an automorphism (Transitivity)

Definition: Let $A=A=\bigoplus_{j=0}^{\infty} A_j$ be a connected $\mathbb{N}$-graded $k$-graded algebra and let $\phi\in\text{Aut($A$)}$ be a graded automorphism of degree zero. A new graded algebra ...
Lumi's user avatar
  • 11
9 votes
0 answers
184 views

Singularity category of a hypersurface associated to $M_{11}$

For reasons to do with classifying spaces of finite groups, I have the following algebra. Let $k$ be a field of characteristic two, and let $R = k[x,y,z]/(x^2 y + z^2)$, as a graded $k$-algebra with $|...
Dave Benson's user avatar
  • 13.9k
0 votes
0 answers
41 views

Is any deformation of an acyclic complex gauge equivalent to a trivial one?

This question is related to this question. Let $(C^{\bullet},d)$ be a cochain complex over a field $k$ with char$k$=0. We fix an Artin local $k$-algebra $(A,m)$. A deformation of $d$ is a new operator ...
Zhaoting Wei's user avatar
  • 8,767

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