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Related papers: Rigid rational homotopy types

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Let k be an infinite perfect field. We provide a general criterion for a spectrum in the stable homotopy category over k to be effective, i.e. to be in the localizing subcategory generated by the suspension spectra of smooth schemes. As a…

K-Theory and Homology · Mathematics 2018-07-09 Tom Bachmann , Jean Fasel

Let $S$ be a complete flat surface, such as the Euclidean plane. We determine the homeomorphism class of the space of all curves on $S$ which start and end at given points in given directions and whose curvatures are constrained to lie in a…

Geometric Topology · Mathematics 2025-10-28 Nicolau C. Saldanha , Pedro Zühlke

We give a new constructive proof of homotopy canonicity for homotopy type theory (HoTT). Canonicity proofs typically involve gluing constructions over the syntax of type theory. We instead use a gluing construction over a "strict Rezk…

Category Theory · Mathematics 2025-10-09 Rafaël Bocquet

Let G be a real reductive algebraic group with maximal compact subgroup K, and let F be a rank r free group. Here, we summarize the construction of a natural strong deformation retraction from the space of closed orbits in Hom(F,G)/G to the…

Algebraic Topology · Mathematics 2016-09-23 Ana Casimiro , Carlos Florentino , Sean Lawton , André Oliveira

Topological periodic cyclic homology (i.e., $\mathbb{T}$-Tate fixed points of $THH$) has the structure of a strong symmetric monoidal functor of smooth and proper dg categories over a perfect field of finite characteristic.

K-Theory and Homology · Mathematics 2022-05-05 Andrew J. Blumberg , Michael A. Mandell

We prove a formality theorem for algebraic objects internal to smooth complex varieties that are not compact but whose mixed Hodge structure has a certain purity property.

Algebraic Topology · Mathematics 2017-03-27 Geoffroy Horel

Let $R$ be a discrete valuation ring of mixed characteristics $(0,p)$, with finite residue field $k$ and fraction field $K$, let $k'$ be a finite extension of $k$, and let $X$ be a regular, proper and flat $R$-scheme, with generic fibre…

Algebraic Geometry · Mathematics 2011-09-13 Pierre Berthelot , Hélène Esnault , Kay Rülling

In the rational cohomology of a 1-connected space a structure of $C_{\infty}$-algebra is constructed and it is shown that this object determines the rational homotopy type

Algebraic Topology · Mathematics 2008-11-12 Tornike Kadeishvili

For a smooth manifold A, we consider the ordered configuration space F_k(AxR) of k distinct points in AxR. We obtain an explicit homotopy construction of the configuration space F_k(AxR) and of the (k-2)-fold suspension of F_k(A). Under…

Algebraic Topology · Mathematics 2007-05-23 Jean-Philippe Jourdan

We construct the crystalline fundamental group of a semi-stable variety over a field of positive characteristic using the log De Rham-Witt complex and Navarro-Aznar's derived Thom-Whitney functor. This approach gives a relatively direct…

Algebraic Geometry · Mathematics 2007-05-23 Minhyong Kim , Richard M. Hain

Fix a number field k. We prove that if there is an algorithm for deciding whether a smooth projective geometrically integral k-variety has a k-point, then there is an algorithm for deciding whether an arbitrary k-variety has a k-point and…

Number Theory · Mathematics 2017-04-03 Bjorn Poonen

We introduce some classes of genuine higher categories in homotopy type theory, defined as well-behaved subcategories of the category of types. We give several examples, and some techniques for showing other things are not examples. While…

Category Theory · Mathematics 2013-11-11 James Cranch

A series of recent papers by Bergfalk, Lupini and Panagiotopoulus developed the foundations of a field known as `definable algebraic topology,' in which classical cohomological invariants are enriched by viewing them as groups with a Polish…

Logic · Mathematics 2025-07-21 Nicholas Meadows

This paper investigates the class of finitely presented monoids defined by homogeneous (length-preserving) relations from a computational perspective. The properties of admitting a finite complete rewriting system, having finite derivation…

Group Theory · Mathematics 2017-05-16 Alan J. Cain , Robert Gray , António Malheiro

For every simplicial complex K there exists a vertex-transitive simplicial complex homotopy equivalent to a wedge of copies of K with some copies of the circle. It follows that every simplicial complex can occur as a homotopy wedge summand…

Combinatorics · Mathematics 2014-09-18 Michal Adamaszek

We give explicit formulas for the ranks of the third and fourth homotopy groups of all oriented closed simply-connected four manifolds in terms of their second Betti numbers. We also show that the rational homotopy type of these manifolds…

Algebraic Topology · Mathematics 2007-05-23 S. Terzic

This note extends Quillen's Theorem A to a large class of categories internal to topological spaces. This allows us to show that under a mild condition a fully faithful and essentially surjective functor between such topological categories…

Algebraic Topology · Mathematics 2024-06-12 David Michael Roberts

Let $M$ be a simply connected closed manifold of dimension $n$. We study the rational homotopy type of the configuration space of 2 points in $M$, $F(M,2)$. When $M$ is even dimensional, we prove that the rational homotopy type of $F(M,2)$…

Algebraic Topology · Mathematics 2015-05-26 Hector Cordova Bulens

The fine curve complex of a surface is a simplicial complex whose vertices are essential simple closed curves and whose $k$-simplices are collections of $k+1$ disjoint curves. We prove that the fine curve complex is homotopy equivalent to…

Geometric Topology · Mathematics 2026-02-11 Ryan Dickmann , Zachary Himes , Alexander Nolte , Roberta Shapiro

We introduce several homotopy equivalence relations for proper holomorphic mappings between balls. We provide examples showing that the degree of a rational proper mapping between balls (in positive codimension) is not a homotopy invariant.…

Complex Variables · Mathematics 2015-09-30 John P. D'Angelo , Jiri Lebl