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Related papers: Affine Grassmannians in A^1-algebraic topology

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We show that functors like algebraic $K$-theory (such as unitary or symplectic $K$-functors), as well as the higher Grothendieck--Witt groups, possess the local constancy condition for Henselian valuation rings. Namely, taken with finite…

K-Theory and Homology · Mathematics 2024-05-29 Serge Yagunov

We prove the equivalence between the categories of motives of rigid analytic varieties over a perfectoid field $K$ of mixed characteristic and over the associated (tilted) perfectoid field $K^{\flat}$ of equal characteristic. This can be…

Algebraic Geometry · Mathematics 2019-02-20 Alberto Vezzani

Given a rigid tensor-triangulated category and a vector space valued homological functor for which the K\"{u}nneth isomorphism holds, we construct a universal graded-Tannakian category through which the given homological functor factors. We…

Algebraic Geometry · Mathematics 2020-01-24 Daniel Schäppi

Riemannian geodesic orbit spaces (G/H,g) are natural generalizations of symmetric spaces, defined by the property that their geodesics are orbits of one-parameter subgroups of G. We study the geodesic orbit spaces of the form (G/S,g), where…

Differential Geometry · Mathematics 2020-04-28 Nikolaos Panagiotis Souris

In this paper, we introduce an algebraic-topological invariant for commutative pm-rings, termed the spectral fundamental group, which is denoted by $\pi_{k}^{alg}(A)$. This group is defined via homotopy classes of loops within the space of…

Algebraic Topology · Mathematics 2026-03-27 Biswajit Mitra , Sourav Koner

Let $G$ be a finite group acting on a small category $I$. We study functors $X \colon I \to \mathscr{C}$ equipped with families of compatible natural transformations that give a kind of generalized $G$-action on $X$. Such objects are called…

Algebraic Topology · Mathematics 2016-03-09 Emanuele Dotto , Kristian Moi

In previous work, the authors constructed and studied a lift of the Galois correspondence to stable homotopy categories. In particular, if $L/k$ is a finite Galois extension of fields with Galois group $G$, there is a functor $c_{L/k}^*$…

Algebraic Topology · Mathematics 2017-02-01 J. Heller , K. Ormsby

We study torus-equivariant algebraic $K$-theory of affine Schubert varieties in the perfect affine Grassmannians over $\mathbb{F}_p$. We further compare it to the torus-equivariant Hochschild homology of perfect complexes, which has a…

Algebraic Geometry · Mathematics 2026-04-20 Jakub Löwit

Let K be a complete discretely valued field of mixed characteristics (0, p) with perfect residue field. One of the central objects of study in p-adic Hodge theory is the category of continuous representations of the absolute Galois group of…

Number Theory · Mathematics 2018-02-28 Kiran S. Kedlaya , Jonathan Pottharst

Let $k$ be an algebraically closed field of characteristic $0$ or $p>2$. Let $\mathcal{G}$ be an affine supergroup scheme over $k$. We classify the indecomposable exact module categories over the tensor category ${\rm sCoh}_{\rm…

Quantum Algebra · Mathematics 2021-01-26 Shlomo Gelaki

We solve affirmatively the homotopy limit problem for $K$-theory over fields of finite virtual cohomological dimension. Our solution employs the motivic slice filtration and the first motivic Hopf map.

K-Theory and Homology · Mathematics 2017-01-24 Oliver Röndigs , Markus Spitzweck , Paul Arne Østvær

Assuming the Hodge conjecture for abelian varieties of CM-type, one obtains a good category of abelian motives over the algebraic closure of a finite field and a reduction functor to it from the category of CM-motives. Consequentely, one…

Algebraic Geometry · Mathematics 2007-05-23 J. S. Milne

For a reductive group $G$ over a ring $A$, its affine Grassmannian $\mathrm{Gr}_G$ plays important roles in a wide range of subjects and is typically defined as the \'etale sheafification of the presheaf quotient $LG/L^+G$ of the loop group…

Algebraic Geometry · Mathematics 2025-05-20 Kestutis Cesnavicius

Let $\Gamma$ be a divisible subgroup of $(\mathbb{R},+)$. Our central result states that, at the level of Grothendieck groups, the classification of $\Gamma$-rational polyhedra in $\mathbb{R}^n$ up to affine transformations in…

Algebraic Geometry · Mathematics 2024-02-20 Johannes Nicaise

We define a motivic analogue of the Haar measure for groups of the form G(k((t))), where k is an algebraically closed field of characteristic zero, and G is a reductive algebraic group defined over k. A classical Haar measure on such groups…

Algebraic Geometry · Mathematics 2016-09-07 Julia Gordon

Consider the abelian category ${\mathcal C}$ of commutative group schemes of finite type over a field $k$, its full subcategory ${\mathcal F}$ of finite group schemes, and the associated pro category ${\rm Pro}({\mathcal C})$ (resp. ${\rm…

Algebraic Geometry · Mathematics 2019-05-08 Michel Brion

We prove that the $\infty$-category of $\mathrm{MGL}$-modules over any scheme is equivalent to the $\infty$-category of motivic spectra with finite syntomic transfers. Using the recognition principle for infinite $\mathbb{P}^1$-loop spaces,…

Algebraic Geometry · Mathematics 2020-12-23 Elden Elmanto , Marc Hoyois , Adeel A. Khan , Vladimir Sosnilo , Maria Yakerson

Following ideas of Bondarko, we construct a DG category whose homotopy category is equivalent to the full subcategory of motives over a base-scheme $S$ generated by the motives of smooth projective $S$-schemes, assuming that $S$ is itself…

Algebraic Geometry · Mathematics 2008-07-16 Marc Levine

The isotropic Grassmannian parametrizes isotropic subspaces of a vector space equipped with a quadratic form. In this paper, we show that any maximal isotropic Grassmannian in its Pl\"ucker embedding can be defined by pulling back the…

Algebraic Geometry · Mathematics 2023-08-21 Tim Seynnaeve , Nafie Tairi

We study the structure of the rational motivic stable homotopy category over general base schemes. Our first class of results concerns the six operations: we prove absolute purity, stability of constructible objects, and…

Algebraic Geometry · Mathematics 2021-03-15 Frédéric Déglise , Jean Fasel , Adeel A. Khan , Fangzhou Jin