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Related papers: Quasi-2-Segal sets

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We establish a Quillen equivalence relating the homotopy theory of Segal operads and the homotopy theory of simplicial operads, from which we deduce that the homotopy coherent nerve functor is a right Quillen equivalence from the model…

Algebraic Topology · Mathematics 2014-02-26 Denis-Charles Cisinski , Ieke Moerdijk

Many special classes of simplicial sets, such as the nerves of categories or groupoids, the 2-Segal sets of Dyckerhoff and Kapranov, and the (discrete) decomposition spaces of G\'{a}lvez, Kock, and Tonks, are characterized by the property…

Category Theory · Mathematics 2024-03-05 Carmen Constantin , Tobias Fritz , Paolo Perrone , Brandon Shapiro

We prove a version of Quillen's theorems for a map of semi-Segal spaces. We construct a bi-semi-simplicial resolution similar to the one associated to a functor of non-unital topological categories. As a consequence we can represent the…

Algebraic Topology · Mathematics 2024-11-19 Yuxun Sun

We use Cisinski's machinery to construct and study model structures on the category of simplicial sets whose classes of fibrant objects generalize quasi-categories. We identify a lifting condition which captures the homotopical behavior of…

Algebraic Topology · Mathematics 2025-04-02 Matthew Feller

In this paper we redevelop the foundations of the category theory of quasi-categories (also called infinity-categories) using 2-category theory. We show that Joyal's strict 2-category of quasi-categories admits certain weak 2-limits, among…

Category Theory · Mathematics 2015-06-18 Emily Riehl , Dominic Verity

We study the simplicial coalgebra of chains on a simplicial set with respect to three notions of weak equivalence. To this end, we construct three model structures on the category of reduced simplicial sets for any commutative ring R. The…

Algebraic Topology · Mathematics 2024-02-06 George Raptis , Manuel Rivera

The complement of the union of a collection of disjoint open disks in the $2$-sphere is called a Schottky set. We prove that a subset $S$ of the $2$-sphere is quasiconformally equivalent to a Schottky set if and only if every pair of…

Complex Variables · Mathematics 2026-05-05 Dimitrios Ntalampekos

In this paper we construct the category of birational spaces as the category in which Temkin's relative Riemann-Zariski spaces are naturally included. Furthermore we develop an analogue of Raynaud's theory. We prove that the category of…

Algebraic Geometry · Mathematics 2013-12-02 Uri Brezner

Algebra objects in $\infty$-categories of spans admit a description in terms of $2$-Segal objects. We introduce a notion of span between $2$-Segal objects and extend this correspondence to an equivalence of $\infty$-categories.…

Algebraic Topology · Mathematics 2025-10-30 Jonte Gödicke

Neretin and Segal independently defined a semigroup of annuli with boundary parametrizations, which is viewed as a complexification of the group of diffeomorphisms of the circle. By extending the parametrizations to quasisymmetries, we show…

Complex Variables · Mathematics 2014-02-26 David Radnell , Eric Schippers

We define groupoidal and $(n+k)$-truncated $n$-quasi-categories, which are the translation to the world of $n$-quasi-categories of groupoidal and truncated $(\infty, n)$-$\Theta$-spaces defined by Rezk. We show that these objects are the…

Category Theory · Mathematics 2024-06-04 Victor Brittes

We produce a highly structured way of associating a simplicial category to a model category which improves on work of Dwyer and Kan and answers a question of Hovey. We show that model categories satisfying a certain axiom are Quillen…

Algebraic Topology · Mathematics 2020-01-13 Charles Rezk , Stefan Schwede , Brooke Shipley

If all objects of a simplicial combinatorial model category \cat A are cofibrant, then there exists the homotopy model structure on the category of small functors $\sS^{\cat A}$, where the fibrant objects are homotopy functors, i.e.,…

Algebraic Topology · Mathematics 2024-07-24 Boris Chorny , David White

We use the terms "$\infty$-categories" and "$\infty$-functors" to mean the objects and morphisms in an "$\infty$-cosmos." Quasi-categories, Segal categories, complete Segal spaces, naturally marked simplicial sets, iterated complete Segal…

Category Theory · Mathematics 2019-09-23 Emily Riehl , Dominic Verity

We give a criterion for almost Gorenstein property for semigroup rings associated with simplicial semigroups. We extend Nari's theorem for almost symmetric numerical semigroups to simplicial semigroups with higher rank. By this criterion,…

Commutative Algebra · Mathematics 2024-06-11 Kazufumi Eto , Naoyuki Matsuoka , Takahiro Numata , Kei-ichi Watanabe

We give a Quillen equivalence between model structures for simplicial operads, described via the theory of operads, and Segal operads, thought of as certain reduced dendroidal spaces. We then extend this result to give an Quillen…

Algebraic Topology · Mathematics 2014-12-31 Julia E. Bergner , Philip Hackney

We construct a model structure on the category of ordered simplicial complexes, Quillen equivalent to the standard model structure on simplicial sets. This shows that simplicial complexes, which are fully combinatorial in nature, provide a…

Algebraic Topology · Mathematics 2026-05-18 Melissa Wei

In this paper, motivated by the classical notion of a Strebel quadratic differential on a compact Riemann surfaces without boundary we introduce the notion of a quasi-Strebel structure for a meromorphic differential of an arbitrary order.…

Algebraic Geometry · Mathematics 2020-02-25 Boris Shapiro , Guillaume Tahar

We prove the existence of a model structure on the category of stratified simplicial sets whose fibrant objects are precisely $n$-complicial sets, which are a proposed model for $(\infty,n)$-categories, based on previous work of Verity and…

Algebraic Topology · Mathematics 2020-06-03 Viktoriya Ozornova , Martina Rovelli

Hall algebras and related constructions have had diverse applications in mathematics and physics, ranging from representation theory and quantum groups to Donaldson-Thomas theory and the algebra of BPS states. The theory of $2$-Segal spaces…

Algebraic Topology · Mathematics 2017-11-29 Mark D Penney