• In abstract algebra, a magma, binar, or, rarely, groupoid is a basic kind of algebraic structure. Specifically, a magma consists of a set equipped with...
    18 KB (1,828 words) - 11:16, 17 April 2025
  • In mathematics, the concept of groupoid algebra generalizes the notion of group algebra. Given a groupoid ( G , ⋅ ) {\displaystyle (G,\cdot )} (in the...
    3 KB (285 words) - 23:14, 3 May 2024
  • homotopy theory, a groupoid (less often Brandt groupoid or virtual group) generalises the notion of group in several equivalent ways. A groupoid can be seen...
    39 KB (6,232 words) - 06:39, 6 May 2025
  • In abstract algebra, a partial groupoid (also called halfgroupoid, pargoid, or partial magma) is a set endowed with a partial binary operation. A partial...
    2 KB (278 words) - 11:07, 26 December 2023
  • In category theory, a branch of mathematics, an ∞-groupoid is an abstract homotopical model for topological spaces. One model uses Kan complexes which...
    11 KB (1,667 words) - 05:23, 14 May 2025
  • mentioned above. For example, a finite groupoid algebra is a weak Hopf algebra. In particular, the groupoid algebra on [n] with one pair of invertible arrows...
    35 KB (4,397 words) - 17:17, 1 February 2025
  • In algebraic topology, the fundamental groupoid is a certain topological invariant of a topological space. It can be viewed as an extension of the more...
    9 KB (1,170 words) - 07:28, 24 April 2025
  • the more restrictive notion of a stack in groupoids. An algebraic stack or Artin stack is a stack in groupoids X over the fppf site such that the diagonal...
    34 KB (5,113 words) - 13:03, 2 April 2025
  • In category theory, a branch of mathematics, a groupoid object is both a generalization of a groupoid which is built on richer structures than sets, and...
    5 KB (850 words) - 18:53, 8 December 2024
  • Thumbnail for Algebraic topology
    category theory Higher-dimensional algebra Homological algebra K-theory Lie algebroid Lie groupoid Serre spectral sequence Sheaf Topological quantum field...
    19 KB (2,093 words) - 02:29, 23 April 2025
  • information of a groupoid can be contained in its monoidal category of representations (by a version of Tannaka–Krein duality), in its groupoid algebra or in the...
    1 KB (162 words) - 02:35, 22 January 2019
  • In abstract algebra, a central groupoid is an algebraic structure defined by a binary operation ⋅ {\displaystyle \cdot } on a set of elements that satisfies...
    8 KB (1,214 words) - 21:02, 14 April 2025
  • Graph algebra Incidence algebra Hecke algebra of a locally compact group Path algebra Groupoid algebra Stereotype algebra Stereotype group algebra Hopf...
    9 KB (1,339 words) - 18:05, 11 March 2025
  • correspondence between Lie groups and Lie algebras, Lie groupoids are the global counterparts of Lie algebroids. Lie groupoids were introduced by Charles Ehresmann...
    44 KB (7,436 words) - 07:45, 15 October 2024
  • higher-dimensional algebra (HDA), a double groupoid is a generalisation of a one-dimensional groupoid to two dimensions, and the latter groupoid can be considered...
    17 KB (1,525 words) - 16:12, 4 May 2025
  • higher-dimensional algebra and homotopy theory, a double groupoid generalises the notion of groupoid and of category to a higher dimension. A double groupoid D is a...
    11 KB (1,536 words) - 23:06, 10 December 2024
  • being categories and groupoids. This leads on to the subject of higher-dimensional algebra which can be defined as the study of algebraic theories with partial...
    25 KB (3,043 words) - 08:54, 11 February 2025
  • the notion of algebraic stacks was defined by Michael Artin. One of the motivating examples of an algebraic stack is to consider a groupoid scheme ( R ...
    24 KB (3,767 words) - 13:42, 17 May 2025
  • Neumann algebras of a measurable equivalence relation and a measurable groupoid can be defined. These examples generalise von Neumann group algebras and the...
    42 KB (5,917 words) - 00:42, 7 April 2025
  • Seifert–Van Kampen theorem (category Theorems in algebraic topology)
    the category of groupoids. This theorem gives the transition from topology to algebra, in determining completely the fundamental groupoid π 1 ( X , A )...
    21 KB (3,373 words) - 16:41, 4 May 2025
  • types of algebraic structures are studied. Abstract algebra is primarily the study of specific algebraic structures and their properties. Algebraic structures...
    19 KB (2,223 words) - 21:00, 23 September 2024
  • Thumbnail for Category (mathematics)
    Category (mathematics) (category Algebraic structures)
    Actually, in the view of category the only difference between groupoid and group is that a groupoid may have more than one object but the group must have only...
    21 KB (2,525 words) - 18:54, 19 March 2025
  • In abstract algebra, a partial algebra is a generalization of universal algebra to partial operations. partial groupoid field — the multiplicative inversion...
    2 KB (176 words) - 10:51, 28 November 2024
  • structure. If C is a group (thought of as a groupoid with a single object), then RC is the group algebra. If C is a monoid (thought of as a category with...
    6 KB (937 words) - 07:35, 5 March 2024
  • Nichols algebras, 2008. Heckenberger: Nichols Algebras (Lecture Notes), 2008 http://www.mi.uni-koeln.de/~iheckenb/na.pdf Heckenberger: The Weyl groupoid of...
    29 KB (5,008 words) - 02:32, 15 April 2024
  • In mathematics, an action groupoid or a transformation groupoid is a groupoid that expresses a group action. Namely, given a (right) group action X ×...
    2 KB (344 words) - 14:11, 29 April 2025
  • Thumbnail for Group (mathematics)
    x)\simeq G} ⁠. More generally, a groupoid is any small category in which every morphism is an isomorphism. In a groupoid, the set of all morphisms in the...
    102 KB (13,144 words) - 11:29, 7 May 2025
  • Category theory Monoidal category Groupoid Group object Coalgebra Bialgebra Hopf algebra Magma object Torsion (algebra) Symbolic mathematics Finite field...
    12 KB (1,129 words) - 10:50, 10 October 2024
  • Algebra. Springer. pp. 21–83. doi:10.1007/978-3-642-99902-4_2. ISBN 978-3-642-99902-4. Brown, R. (1970). "Fibrations of groupoids" (PDF). J. Algebra....
    29 KB (5,041 words) - 00:21, 26 April 2025
  • Differential Geometry (Wiley Classics Library) Volume 1, 2. Wedge Product of Lie Algebra Valued One-Form groupoid of Lie-algebra valued forms at the nLab...
    8 KB (1,555 words) - 14:23, 26 January 2025