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Categorification is the process of finding category-theoretic analogs of set-theoretic concepts by replacing sets with categories, functions with functors, and equations between functions by natural isomorphisms between functors, which in…

Quantum Algebra · Mathematics 2014-11-18 John C. Baez , James Dolan

It is well-known that biological phenomena are emergent. Emergent phenomena are quite interesting and amazing. However, they are difficult to be understood. Due to this difficulty, we propose a theory to describe emergence based on a…

Category Theory · Mathematics 2018-10-30 Giuliano Gadioli La Guardia , Pedro Jeferson Miranda

We will show that every element of a finitely generated abelian group is automorphically equivalent what we will define to be a {\em representative element} in a {\em repeat-free subgroup}, and for finite abelian groups we can count the…

Group Theory · Mathematics 2011-09-12 Charles F. Rocca

We define a new model structure on the category of small categories, which is intimately related to the notion of coverings and fundamental groups of small categories. Fibrant objects in the model structure coincide with groupoids, and the…

Category Theory · Mathematics 2012-05-08 Kohei Tanaka

We introduce a topology on the space of all isomorphism types represented in a given class of countable models, and use this topology as an aid in classifying the isomorphism types. This mixes ideas from effective descriptive set theory and…

Logic · Mathematics 2019-08-20 Russell Miller

Algebraic structures such as monoids, groups, and categories can be formulated within a category using commutative diagrams. In many common categories these reduce to familiar cases. In particular, group objects in Grp are abelian groups,…

Category Theory · Mathematics 2007-05-23 Magnus Forrester-Barker

Most categorical models for dependent types have traditionally been heavily set based: contexts form a category, and for each we have a set of types in said context -- and for each type a set of terms of said type. This is the case for…

Logic in Computer Science · Computer Science 2023-12-25 Greta Coraglia , Jacopo Emmenegger

We develop a general theory of (extended) inner autoequivalences of objects of any 2-category, generalizing the theory of isotropy groups to the 2-categorical setting. We show how dense subcategories let one compute isotropy in the presence…

Category Theory · Mathematics 2024-05-28 Pieter Hofstra , Martti Karvonen

We determine which simple algebraic groups of type $^3D_4$ over arbitrary fields of characteristic different from 2 admit outer automorphisms of order 3, and classify these automorphisms up to conjugation. The criterion is formulated in…

Group Theory · Mathematics 2014-09-08 Max-Albert Knus , Jean-Pierre Tignol

The inner automorphisms of a group G can be characterized within the category of groups without reference to group elements: they are precisely those automorphisms of G that can be extended, in a functorial manner, to all groups H given…

Rings and Algebras · Mathematics 2013-05-10 George M. Bergman

We present a soundness theorem for a dependent type theory with context constants with respect to an indexed category of (finite, abstract) simplical complexes. The point of interest for computer science is that this category can be seen to…

Logic · Mathematics 2020-07-08 Henrik Forssell , Håkon Robbestad Gylterud , David I. Spivak

Identifiability concerns finding which unknown parameters of a model can be estimated from given input-output data. If some subset of the parameters of a model cannot be determined given input-output data, then we say the model is…

Algebraic Geometry · Mathematics 2014-11-03 Nicolette Meshkat , Seth Sullivant , Marisa Eisenberg

We give a necessary and sufficient condition in terms of group cohomology for two indecomposable module categories over a group-theoretical fusion category ${\mathcal C}$ to be equivalent. This concludes the classification of such module…

Quantum Algebra · Mathematics 2017-06-20 Sonia Natale

Autoregressive language models achieve remarkable performance, yet a unified theory explaining their internal mechanisms, how training shapes representations, and why these representations support complex behavior remains incomplete. We…

Machine Learning · Computer Science 2026-05-14 Yifan Zhang

We extend the framework of combinatorial model categories, so that the category of small presheaves over large indexing categories and ind-categories would be embraced by the new machinery called class-combinatorial model categories. The…

Algebraic Topology · Mathematics 2019-12-06 Boris Chorny , Jiří Rosický

In this paper, we propose an abstract definition of dependent type theories as essentially algebraic theories. One of the main advantages of this definition is its composability: simple theories can be combined into more complex ones, and…

Logic · Mathematics 2017-03-28 Valery Isaev

We introduce a mathematical framework for retrosynthetic analysis, an important research method in synthetic chemistry. Our approach represents molecules and their interaction using string diagrams in layered props - a recently introduced…

Logic in Computer Science · Computer Science 2023-11-08 Ella Gale , Leo Lobski , Fabio Zanasi

We put a model structure on the category of categories internal to simplicial sets whose weak equivalences are reflected by the nerve functor to bisimplicial sets with Rezk's model structure. This model structure is shown to be Quillen…

Algebraic Topology · Mathematics 2016-10-12 Geoffroy Horel

Isomorphism is central to the structure of mathematics and has been formalized in various ways within dependent type theory. All previous treatments have done this by replacing quantification over sets with quantification over groupoids of…

Logic in Computer Science · Computer Science 2020-05-13 David McAllester

We characterize the groups isomorphic to full automorphism groups of ordered abelian groups. The result will follow from classical theorems on ordered groups adding an argument from proofs used to realize rings as endomorphism rings of…

Logic · Mathematics 2007-05-23 Rüdiger Göbel , Saharon Shelah