Results 71 to 80 of about 7,293 (133)
Combinatorial Hopf algebra of supercharacters of type D [PDF]
Discrete Mathematics & Theoretical Computer Science, 2012 We provide a Hopf algebra structure on the supercharacter theory for the unipotent upper triangular group of type {D} over a finite field. Also, we make further comments with respect to types {B} and {C}. Type {A} was explored by M. Aguiar et. al (2010), thus this extended abstract is a contribution to understand combinatorially the supercharacter ...
openaire +3 more sources
GL‐algebras in positive characteristic II: The polynomial ring
Proceedings of the London Mathematical Society, Volume 131, Issue 6, December 2025.Abstract We study GL$\mathbf {GL}$‐equivariant modules over the infinite variable polynomial ring S=k[x1,x2,…,xn,…]$S = k[x_1, x_2, \ldots, x_n, \ldots]$ with k$k$ an infinite field of characteristic p>0$p > 0$. We extend many of Sam–Snowden's far‐reaching results from characteristic zero to this setting.
Karthik Ganapathy
wiley +1 more source
Cohomotopy sets of (n−1)$(n-1)$‐connected (2n+2)$(2n+2)$‐manifolds for small n$n$
Transactions of the London Mathematical Society, Volume 12, Issue 1, December 2025.Abstract Let M$M$ be a closed orientable (n−1)$(n-1)$‐connected (2n+2)$(2n+2)$‐manifold, n⩾2$n\geqslant 2$. In this paper, we combine the Postnikov tower of spheres and the homotopy decomposition of the reduced suspension space ΣM$\Sigma M$ to investigate the (integral) cohomotopy sets π*(M)$\pi ^\ast (M)$ for n=2,3,4$n=2,3,4$, under the assumption ...
Pengcheng Li, Jianzhong Pan, Jie Wu
wiley +1 more source
Real models for the framed little n$n$‐disks operads
Journal of Topology, Volume 18, Issue 4, December 2025.Abstract We study the action of the orthogonal group on the little n$n$‐disks operads. As an application we provide small models (over the reals) for the framed little n$n$‐disks operads. It follows in particular that the framed little n$n$‐disks operads are formal (over the reals) for n$n$ even and coformal for all n$n$.
Anton Khoroshkin, Thomas Willwacher
wiley +1 more source
Structure theorems for braided Hopf algebras
Journal of Topology, Volume 18, Issue 4, December 2025.Abstract We develop versions of the Poincaré–Birkhoff–Witt and Cartier–Milnor–Moore theorems in the setting of braided Hopf algebras. To do so, we introduce new analogs of a Lie algebra in the setting of a braided monoidal category, using the notion of a braided operad.
Craig Westerland
wiley +1 more source
Higher order peak algebras [PDF]
, 2004 Using the theory of noncommutative symmetric functions, we introduce the higher order peak algebras, a sequence of graded Hopf algebras which contain the descent algebra and the usual peak algebra as initial cases (N = 1 and N = 2).
Krob, Daniel, Thibon, Jean-Yves
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Combinatorial Hopf algebra for interconnected nonlinear systems
, 2018 A detailed expose of the Hopf algebra approach to interconnected input-output systems in nonlinear control theory is presented. The focus is on input-output systems that can been represented in terms of Chen-Fliess functional expansions or Fliess operators. This provides a starting point for a discrete-time version of this theory.
Espinosa, Luis A. Duffaut +2 more
openaire +2 more sources
Preordered forests, packed words and contraction algebras
, 2013 We introduce the notions of preordered and heap-preordered forests, generalizing the construction of ordered and heap-ordered forests. We prove that the algebras of preordered and heap-preordered forests are Hopf for the cut coproduct, and we construct a
Mansuy, Anthony
core
(Non)Commutative Hopf algebras of trees and (quasi)symmetric functions [PDF]
, 2007 The Connes-Kreimer Hopf algebra of rooted trees, its dual, and the Foissy Hopf algebra of of planar rooted trees are related to each other and to the well-known Hopf algebras of symmetric and quasi-symmetric functions via a pair of commutative diagrams ...
Hoffman, Michael E.
core
Hopf monoids from class functions on unitriangular matrices
, 2012 We build, from the collection of all groups of unitriangular matrices, Hopf monoids in Joyal's category of species. Such structure is carried by the collection of class function spaces on those groups, and also by the collection of superclass function ...
Aguiar +12 more
core +3 more sources