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In the paper we answer the following question: for a morphism of varieties (or, more generally, stacks), when the derived category of the base can be recovered from the derived category of the covering variety by means of descent theory? As…

Algebraic Geometry · Mathematics 2015-05-27 Alexey Elagin

We construct a category $\OrdFor$ as an arboreal extension of $\Delta_{\mathrm{epi}}\subseteq\Delta$, whose morphisms are ordered forests composed by grafting. We define a full functor $\pi\colon \OrdFor\to\Delta_{\mathrm{epi}}^{op}$…

Algebraic Topology · Mathematics 2026-04-03 Atabey Kaygun

We propose a novel recurrent attentional structure to localize and recognize objects jointly. The network can learn to extract a sequence of local observations with detailed appearance and rough context, instead of sliding windows or…

Computer Vision and Pattern Recognition · Computer Science 2017-12-20 Jie Lyu , Zejian Yuan , Dapeng Chen

Both simplicial sets and simplicial spaces are used pervasively in homotopy theory as presentations of spaces, where in both cases we extract the "underlying space" by taking geometric realization. We have a good handle on the category of…

Algebraic Topology · Mathematics 2015-10-20 Aaron Mazel-Gee

We aim to localize objects in images using image-level supervision only. Previous approaches to this problem mainly focus on discriminative object regions and often fail to locate precise object boundaries. We address this problem by…

Computer Vision and Pattern Recognition · Computer Science 2016-09-15 Vadim Kantorov , Maxime Oquab , Minsu Cho , Ivan Laptev

We give a classification of substructures (= closed subbifunctors) of a given skeletally small extriangulated category by using the category of defects, in a similar way to the author's classification of exact structures of a given additive…

Category Theory · Mathematics 2022-08-08 Haruhisa Enomoto

In this paper we take up again the deformation theory for $K$-linear pseudofunctors initiated in a previous work (Adv. Math. 182 (2004) 204-277). We start by introducing a notion of a 2-cosemisimplicial object in an arbitrary 2-category and…

Quantum Algebra · Mathematics 2013-08-13 Josep Elgueta

We give divisibility results for the (global) characteristic varieties of hypersurface complements expressed in terms of the local characteristic varieties at points along one of the irreducible components of the hypersurface. As an…

Algebraic Topology · Mathematics 2019-02-14 Yongqiang Liu , Laurentiu Maxim

A classical result of Bondal-Orlov states that a standard flip in birational geometry gives rise to a fully faithful functor between derived categories of coherent sheaves. We complete their embedding into a semiorthogonal decomposition by…

Algebraic Geometry · Mathematics 2023-02-22 Pieter Belmans , Lie Fu , Theo Raedschelders

Let X ->Y be a Zariski locally trivial fibration of smooth complex projective varieties, with fiber F. We give a structure theorem for the derived category of X provided both F and Z have a full strongly exceptional collection of line…

Algebraic Geometry · Mathematics 2011-02-10 L. Costa , S. Di Rocco , R. M. Miró-Roig

We show that silting modules are closely related with localisations of rings. More precisely, every partial silting module gives rise to a localisation at a set of maps between countably generated projective modules and, conversely, every…

Representation Theory · Mathematics 2019-04-12 Frederik Marks , Jan Stovicek

We develop a general framework of Euclidean patterns and pattern spaces of translational finite local complexity (FLC), analogues of translational tiling spaces. The notion of a self affine substitution of tilings is extended to both…

Dynamical Systems · Mathematics 2026-05-29 James J. Walton

In this note we show that in the simplicial setting, the classifying space construction converts short exact sequences of groups not just to homotopy fibrations, but in fact to fibre bundles.

Algebraic Topology · Mathematics 2025-07-04 Matthias Franz

We introduce an interesting method of proving separable reduction theorems - the method of elementary submodels. We are studying whether it is true that a set (function) has given property if and only if it has this property with respect to…

Functional Analysis · Mathematics 2013-01-08 Marek Cúth

We set up a general framework for enriching a subcategory of the category of noncommutative sets over a category C using products of the objects of a non-\Sigma operad P in \C. By viewing the simplicial category as a subcategory of the…

Algebraic Topology · Mathematics 2007-05-23 Vigleik Angeltveit

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

Reusable model design becomes desirable with the rapid expansion of computer vision and machine learning applications. In this paper, we focus on the reusability of pre-trained deep convolutional models. Specifically, different from…

Computer Vision and Pattern Recognition · Computer Science 2017-07-21 Xiu-Shen Wei , Chen-Lin Zhang , Jianxin Wu , Chunhua Shen , Zhi-Hua Zhou

It is proved that the space of differential forms with weak exterior and co-derivative, is compactly embedded into the space of square integrable differential forms. Mixed boundary conditions on weak Lipschitz domains are considered.…

Analysis of PDEs · Mathematics 2019-05-01 Sebastian Bauer , Dirk Pauly , Michael Schomburg

As observed recently by various people the topos $\mathbf{sSet}$ of simplicial sets appears as essential subtopos of a topos $\mathbf{cSet}$ of cubical sets, namely presheaves over the category $\mathbf{FL}$ of finite lattices and monotone…

Category Theory · Mathematics 2021-03-15 Thomas Streicher , Jonathan Weinberger

In this short note we observe that the Serre functor on the residual category of a complete intersection can be easily described in the framework of hybrid models. Using this description we recover some recent results of Kuznetsov and…

Algebraic Geometry · Mathematics 2023-05-24 Federico Barbacovi , Ed Segal