English
Related papers

Related papers: Non-representable six-functor formalisms

200 papers

In this article, we give a construction of the (un-)stable motivic homotopy category of an algebraic stack in the spirit of Morel-Voevodsky. We prove that this new construction agrees with the stable motivic homotopy category defined by…

Algebraic Geometry · Mathematics 2025-11-04 Neeraj Deshmukh , Felix Sefzig

In this paper, we develop the notion of presentability in the parametrised homotopy theory framework of Barwick-Dotto-Glasman-Nardin-Shah over orbital categories. We formulate and prove a characterisation of parametrised presentable…

Algebraic Topology · Mathematics 2024-01-04 Kaif Hilman

In this paper one considers three homotopy functors on the category of manifolds, $hH^\ast, cH^\ast, sH^\ast,$ and parallel them with other three homotopy functors on the category of connected commutative differential graded algebras,…

Algebraic Topology · Mathematics 2009-05-12 Dan Burghelea

In this work we use Hodge theoretic methods to study homotopy types of complex projective manifolds with arbitrary fundamental groups. The main tool we use is the \textit{schematization functor} $X \mapsto (X\otimes \mathbb{C})^{sch}$,…

Algebraic Geometry · Mathematics 2014-01-14 L. Katzarkov , T. Pantev , B. Toen

We prove a topological invariance statement for the Morel-Voevodsky motivic homotopy category, up to inverting exponential characteristics of residue fields. This implies in particular that SH[1/p] of characteristic p>0 schemes is invariant…

Algebraic Geometry · Mathematics 2019-10-03 Elden Elmanto , Adeel A. Khan

This article is first in a series of papers where we reprove the statements in constructing the Enhanced Operation Map and the abstract six-functor formalism developed by Liu-Zheng. In this paper, we prove a theorem regarding constructing…

Algebraic Geometry · Mathematics 2025-01-28 Chirantan Chowdhury

We construct an algebraic-cycle based model for the motivic cohomology on the category of schemes of finite type over a field, where schemes may admit arbitrary singularities and may be non-reduced. We show that our theory is functorial on…

Algebraic Geometry · Mathematics 2021-12-30 Jinhyun Park

We review the shape theory of $\infty$-topoi, and relate it with the usual cohomology of locally constant sheaves. Additionally, a new localization of profinite spaces is defined which allows us to extend the \'etale realization functor of…

Algebraic Topology · Mathematics 2017-08-15 Joe Berner

We study the structure of the category of representations of $\mathbf{FA}$, the category of finite sets and all maps, mostly working over a field of characteristic zero. This category is not semi-simple and exhibits interesting features. We…

Representation Theory · Mathematics 2025-09-16 Geoffrey Powell

In this paper, we initiate a study of motivic homotopy theory at infinity. We use the six functor formalism to give an intrinsic definition of the stable motivic homotopy type at infinity of an algebraic variety. Our main computational…

Algebraic Geometry · Mathematics 2021-04-08 Adrien Dubouloz , Frédéric Déglise , Paul Arne Østvær

The purpose of this paper is to explain why the functor that sends a stratified topological space $S$ to the $\infty$-category of constructible (hyper)sheaves on $S$ with coefficients in a large class of presentable $\infty$categories is…

Algebraic Topology · Mathematics 2022-09-09 Peter J. Haine , Mauro Porta , Jean-Baptiste Teyssier

The aim of this paper is to connect two important and apparently unrelated theories: motivic homotopy theory and ramification theory. We construct motivic homotopy categories over a qcqs base scheme $S$, in which cohomology theories with…

Algebraic Geometry · Mathematics 2025-04-04 Junnosuke Koizumi , Hiroyasu Miyazaki , Shuji Saito

We show that if G is a finite constant group acting on a scheme X such that the order of G is invertible in the residue fields of X, then the G-equivariant motivic stable homotopy category of X is equivalent to the stabilization of the…

K-Theory and Homology · Mathematics 2022-05-31 Tom Bachmann

We construct a tensor functor from the category of super representations of the superlinear group Gl(m,n) over a field of characteristic zero to the category of super representations of the linear group Gl(m-n) over some extension field…

Representation Theory · Mathematics 2010-10-20 Rainer Weissauer

We establish the motivic six-functor formalism for fs log schemes. In particular, we prove the exact base change property, projection formula, and Poincar\'e duality. We also define Borel-Moore motivic homology, G-theory, and Chow homology…

Algebraic Geometry · Mathematics 2024-03-13 Doosung Park

This article is the last of the series of articles where we reprove the foundational ideas of abstract six-functor formalisms developed by Liu-Zheng. We prove the theorem of partial adjoints, which is a simplicial technique of encoding…

Algebraic Geometry · Mathematics 2025-02-03 Chirantan Chowdhury

The goal of this article is to extend a theorem of Lurie \[ \mathsf{Sh}_A (X) = \mathsf{Fun}(\mathsf{Exit}_A (X), \mathsf{S}) \] representing constructible sheaves with values in $ \mathsf{S} $, the $ \infty $-category of spaces, on a…

Algebraic Topology · Mathematics 2021-02-25 Damien Lejay

Functorial semi-norms are semi-normed refinements of functors such as singular (co)homology. We investigate how different types of representability affect the (non-)triviality of finite functorial semi-norms on certain functors or classes.…

Algebraic Topology · Mathematics 2015-09-08 Clara Loeh

If $f:S' \to S$ is a finite locally free morphism of schemes, we construct a symmetric monoidal "norm" functor $f_\otimes: \mathcal H_*(S') \to\mathcal H_*(S)$, where $\mathcal H_*(S)$ is the pointed unstable motivic homotopy category over…

Algebraic Geometry · Mathematics 2020-05-29 Tom Bachmann , Marc Hoyois

These notes, written version of a Bourbaki talk, survey Morel-Voevodsky's motivic homotopy theory over a field, with a focus on computations of motivic homotopy sheaves, both stable and unstable. We also describe Isaksen-Wang-Xu's…

Algebraic Geometry · Mathematics 2025-10-21 Frédéric Déglise