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5 votes
1 answer
301 views

Operations on filtered / graded vector spaces via $\mathbb{A}^1 / \mathbb{G}_m$

A well known fact (e.g. Moulinos - The geometry of filtrations) is that one can describe the category of filtered vector spaces as $\operatorname{FilVect} \simeq \operatorname{QCoh}(\mathbb{A}^1/\...
12 votes
0 answers
606 views

What's a holonomic D-module from the point of view of de Rham spaces?

Let $X$ be a smooth algebraic variety over $\mathbb{C}$. We can consider its de Rham space $X_\text{dR}$ as the sheaf on $(\textsf{Sch}/\mathbb{C})_\text{ét}$ defined by $X_\text{dR}(S):= X(S_\text{...
9 votes
2 answers
804 views

Explanation for Lurie's SAG Remark 25.1.3.7

I am trying to understand the theory of simplicial commutative rings or animated rings. I just find a remark in Lurie's book Spectral Algebraic Geometry: Remark 25.3.1.7. Let $f : R[x_1,\ldots ,x_n]\...
3 votes
1 answer
296 views

Derived Koszul complex

Let $X$ be a projective variety over $\mathbb{C}$ and $V$ be a vector bundle over $X$. Let $\pi: V\to X$ be the natural projection. Let $i: X\to V$ be the zero section map. Let $V^\vee$ be the dual ...
3 votes
0 answers
390 views

Status of motives in higher category theory: motives and algebraic cycles through a higher categorical perspective

A while ago this interesting question was asked Derived Algebraic Geometry and Chow Rings/Chow Motives. Primary question: Have there been any recent developments/advances on the above question? If not,...
3 votes
0 answers
181 views

Étale morphisms of derived schemes and stacks

Conventions: In the below, unless otherwise stated, terms regarding derived algebraic geometry will follow the conventions of Yaylali. an algebraic stack will be a stack $\mathscr{S}$ over a base ...
4 votes
0 answers
149 views

'Naive cotangent complex' as 1-truncation of cotangent complex

In the stacks project, there is a 'naive version' of cotangent complex $NL_{S/R}$ for a ring morphism $R\rightarrow S$, given by the chan complex $(I/I^{2}\rightarrow \Omega_{R[S]/R}\otimes_{R[S]}S)$ ...
1 vote
0 answers
62 views

Geometric stability conditions on calabi-yau's fibred over Fano always identical to geometric stability conditions on Fano

I apologize in advance for the long title. This question is motivated primarily by [2], with the explicit example of $\mathbb{P}^2$ and $\omega_{\mathbb{P}^2}$ computed in [3] and [1], respectively. ...
2 votes
1 answer
304 views

The exact sequence for a derived zero locus

For a locally free sheaf of rank one $L$ on a derived scheme and a morphism $s:L\rightarrow O_{X}$, we consider the derived zero locus of $s$ defined by the following derived fiber product $$\require{...
3 votes
0 answers
196 views

Divided power structure on $E_\infty$-algebras?

Let $A$ be a simplicial commutative ring, then it is known that the ideal of elements of degree $\ge1$ in the associated CDGA has a "DG divided power structure," which induces a divided ...
7 votes
1 answer
629 views

Canonical comparison between $\infty$ and ordinary derived categories

This question is a follow-up to a previous question I asked. If $\mathcal{D}(\mathsf{A})$ is the derived $\infty$-category of an (ordinary) abelian category $\mathsf{A},$ then the homotopy category $h\...
2 votes
1 answer
199 views

Does every Artin $\infty$-stack have a formally étale cover by semi-free non-connective CDGAs?

The title essentially says it all. Feel free to assume as many finite generation conditions as you want. For example, I'm pretty sure the Chevalley-Eilenberg complex $\simeq \wedge^\bullet \mathfrak g^...
5 votes
0 answers
223 views

What do we know about effective epimorphisms of derived affine schemes/manifolds?

By default, all terms are understood in the infinity sense (“category” means “(∞,1)-category”, etc.) Recall that the morphism $X \to Y$ is an effective epimorphism if the Čech diagram $$ ... \to X \...
8 votes
1 answer
324 views

$\infty$-categorical enhancement of $\mathsf{D}_\mathsf{B}(\mathsf{A})$

In this question, it is asked why we like to consider $\mathsf{D}_\textrm{qc}(X)$ rather than $\mathsf{D}(\mathsf{QCoh}(X)).$ Professor Cisinski answers rather convincingly that the $\infty$-...
3 votes
1 answer
183 views

Pushforward of exceptional vector bundle is spherical for local P^2

I've been reading through a bit of the literature on stability conditions, and one of the models that has come up is the 'local projective plane'. Explicitly, this is the total space of the canonical ...
4 votes
2 answers
413 views

“Geometric” vs Homotopical completion

There are two notions of completions of slightly different nature, and I am wondering if there is a precise statement relating them. The first one is the “homotopical” (or maybe it should be called ...
2 votes
0 answers
157 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 ...
3 votes
0 answers
151 views

Is a derived scheme determined by classical + formal points?

Say we have a derived scheme over an algebraically closed field $X/k$, viewed as a functor $X : \operatorname{Aff}_k^{\operatorname{op}} \to \infty\operatorname{-Grpd}$ and we know its formal ...
15 votes
1 answer
789 views

Why do we say IndCoh(X) is analogous to the set of distributions on X?

$\DeclareMathOperator\IndCoh{IndCoh}\DeclareMathOperator\QCoh{QCoh}$I've seen it written (for example, in Gaitsgory–Rozenblyum) that for a scheme $X$, the category $\IndCoh(X)$ is to be thought of as ...
7 votes
1 answer
424 views

Kapustin-Witten branes and the derived moduli stack of Higgs bundles

A lot has been discussed on overflow regarding geometric Langlands and the physics of Kapustin and Witten's groundbreaking paper https://arxiv.org/abs/hep-th/0604151. I would like to add my two cents ...
3 votes
0 answers
187 views

Does "derived" make anything constant in non-flat families?

This is an extremely basic (and surely amateurish) question that might be about derived geometry. In usual algebraic geometry, if we have a flat projective morphism $f:X \to S$ with $S$ integral, and ...
3 votes
1 answer
285 views

Is there a notion of injective, projective, flat, dimension for a differential graded algebra?

Given a differential graded algebra $(A_\bullet,d)$, is there a well-defined notion of a K-injective, K-projective, K-flat dimension of a differential graded module, or even of the category of ...
6 votes
1 answer
560 views

Higher descent cohomology

Descent cohomology for a comonad is defined at degrees 0 and 1 by Mesablishvili in his paper "On Descent Cohomology" (as well as by many other authors in many other contexts). For a comonad $\bot$ on ...
3 votes
0 answers
310 views

Algebraic Fukaya categories and mirror symmetry

Dominic Joyce and collaborators have outlined a programme to construct algebraic Fukaya categories on an algebraic symplectic manifold (“Fukaya categories” of complex Lagrangians in complex symplectic ...
10 votes
1 answer
883 views

$\infty$-categorical understanding of Bridgeland stability?

On triangulated categories we have a notion of Bridgeland stability conditions. Is there any known notion of "derived stability conditions" on a stable $\infty$-category $C$ such that they become ...
5 votes
1 answer
445 views

What is the k-linear structure on the derived infinity category of quasi-coherent sheaves?

Let $f : X \overset{f}{\rightarrow} Y \overset{g}{\rightarrow} \mathrm{Spec} (k)$ be morphisms of schemes (feel free to add any hypothesis necessary). Let $\mathrm{QCoh}(Y)$ denote the derived (stable)...
1 vote
0 answers
110 views

Computing Grothendieck group of (unnodal) Enriques surface

Let $X$ be an unnodal Enriques surface together with an isotropic 10-sequence $\{ f_1, \dots, f_{10}\} \subset \operatorname{Num}(X)$, and let $F_i^\pm \in \operatorname{NS}(X)$ denote the two ...
3 votes
1 answer
335 views

resolution property and perfect stacks

Recall that for a scheme $X$, it has the resolution property if every coherent sheaf $E$ on $X$, is the quotient of a finite locally free $\mathcal{O}_X$-module. On the other hand, Ben-Zvi-Nadler-...
3 votes
1 answer
422 views

Derived $\ell$-completion of $\mathbf{Q}_\ell$ sheaf?

I came across some notation that I’m having trouble understanding in Hansen-Scholze’s preprint ‘Relative Perversity.’ In the last paragraph of Proposition 3.4 there is the notation $A\widehat{\otimes^{...
1 vote
1 answer
256 views

Examples when algebraic 1-stack = derived enhancement?

Are there any examples where a usual algebraic 1-stack $X$ and the corresponding derived stack enhancement $\mathbb{R}X$ coincide? Let me take an example from notes of Bertrand Toen, page 41 of https:/...
5 votes
1 answer
334 views

Reference request: category of sheaves of O-modules with coherent cohomology

Suppose $X$ is a smooth algebraic variety (say, in characteristic $0$). It's a folklore result that $D^b\text{Coh}(X)$ is equivalent to the derived category of complexes of sheaves of $\mathcal{O}_X$-...
3 votes
0 answers
451 views

Infinite dimensional dg-manifolds

In Def 2.5.1 in " Derived Quot schemes" by Ciocan-Fontanine and Kapranov, we can find the notion of dg-manifolds. In detail, let $X$ be a dg-scheme over $k$ ($k$ : an algebraic closed field ...
3 votes
1 answer
417 views

Should we expect Kuznetsov component to be independent of exceptional collection

As explained in the comments of this answer, given a smooth Fano 3-fold of index 1 and genus $g \geq 6$, we have two semiorthogonal decompositions $$\langle \text{Ku}(X), \mathcal{E}, \mathcal{O}_X\...
4 votes
0 answers
271 views

Confusion about definition of crystals

In the notes by Lurie there seems to be two possible definition for crystals which both makes sense for arbitrary functors $X : \mathrm{CRing}_k \to \mathrm{Set}$. ($k$ here is a field. We probably ...
4 votes
1 answer
533 views

Two notions of singular support?

Arinkin-Gaitsgory have defined the notion of singular support for any quasismooth $Y$ $$\text{SS}(\mathcal{F})\ \subseteq\ \text{Sing}(Y)$$ and $\mathcal{F}$ any ind-coherent sheaf, where $\text{Sing}(...
2 votes
0 answers
123 views

Moduli stack of doubly periodic complexes?

Let $\mathcal{A}$ be an abelian category. In HAG II Toen and Vessozi built a higher derived stack $X$ whose category of perfect complexes is $\text{Perf}(X)\simeq D^b(\mathcal{A})$. So $X$ is a good ...
1 vote
0 answers
275 views

Fourier-Mukai transform is the derived functor

In Mukai's paper Duality between $D(X)$ and $D(\hat{X})$ with its application to Picard sheaves, Nagoya Math Journal, 1981, there is one sentence that puzzles me. Let $X$ be an abelian variety over an ...
0 votes
0 answers
170 views

Cone of morphism induced by Serre duality

For a smooth projective variety $X$, Serre duality gives an exact autoequivalence on the derived category : $$ S_X : D^\flat(X) \to D^\flat(X), \hspace{3em} S_X(-) = - \otimes \omega_X[\dim X] $$ ...
41 votes
1 answer
3k views

Connes–Consani's absolute geometry and Lurie's spectral algebraic geometry

Alain Connes and Caterina Consani seem to be currently working on "absolute algebraic geometry", which is a kind of "algebraic geometry over the sphere spectrum" (https://arxiv.org/...
2 votes
1 answer
131 views

Right adjoint of subcollection of semi-orthogonal decomposition

Suppose $X$ is a prime Fano threefold of index 1 such that $H = -K_X$ is ample. There is a full classification of the derived category of such threefolds depending on the genus of $X$; in the case ...
2 votes
0 answers
354 views

Higher-order HKR theorems?

Recall that Hochschild-Kostant-Rosenberg -type theorems identify certain smoothness conditions guaranteeing an isomorphism between the cotangent complex and (a shift of) the Hochschild homology of an ...
3 votes
1 answer
176 views

Left adjoint for nested admissible categories

This question is motivated by the construction of the Kuznetsov component on a prime Fano threefold $X$ of index 1 (say genus $g \geq 6$, $g \neq 7, 9$): $$ D^b(X) = \langle Ku(X), E, \mathcal{O}_X \...
2 votes
1 answer
390 views

The stack of equivariant local system is quasi-smooth

Let $G$ be a (connected ?) algebraic group and $X$ a smooth, projective, and connected algebraic curve, both over an algebraically closed field $k$ of characteristic $0$. My questions are then as ...
4 votes
1 answer
499 views

Hard Lefschetz theorem in intersection cohomology

In [1,2] the authors proved the Hard Lefschetz theorem in intersection cohomology: Let $Z$ be a complex projective variety of pure complex dimension $d$, with $\xi\in H^2(Z,\mathbb{Q})$ the first ...
8 votes
1 answer
721 views

Milnor excision for algebraic stacks

Recall that a commutative square of commutative rings $$\begin{matrix} A&\to&B\\ \downarrow &&\downarrow\\ A^\prime&\to&B^\prime\end{matrix}$$ is called a Milnor square if the ...
2 votes
0 answers
189 views

Is the homotopy limit of derived schemes along affine maps a derived scheme?

The title question is true in the setting of ordinary limits and ordinary schemes; that is, given an inverse limit of schemes along affine maps, the limit still lives in the category of schemes. I'd ...
7 votes
1 answer
590 views

If we replace the spectrally ringed space in the definition of a spectral scheme with an arbitrary infinity-topos, what objects do we get?

I'll phrase this in terms of spectral AG, but I'm curious about the same question in the classical context. We define a nonconnective spectral Deligne-Mumford stack to be a spectrally-ringed topos ...
4 votes
0 answers
352 views

What does the cotangent complex tell you when it takes animated inputs?

These two links: What is the cotangent complex good for? and Intuition about the cotangent complex? are quite helpful in giving intution for the cotangent complex in terms of deformations but I don't ...
9 votes
1 answer
748 views

In the not necessarily abelian cat setting, is there a Grothendieck spectral sequence for computing the homotopy of a composition of derived functors?

Recall the Grothendieck spectral sequence which computes the homology groups of a composition of left derived functors $F$ and $G$ on abelian categories: \begin{align*} E_{p,q}^{2}(A)=L_{p}G\circ L_{q}...
3 votes
0 answers
398 views

Applications derived algebraic geometry in Morse theory

Have derived algebraic geometry been used to understand the topology of complex varieties? For example are there any applications in Morse theory? The reason I am asking this is two fold. First one is ...