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Related papers: Witt vectors and Tambara functors

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We consider an intermediate category between the category of finite quivers and a certain category of pseudocompact associative algebras whose objects include all pointed finite dimensional algebras. We define the completed path algebra and…

Rings and Algebras · Mathematics 2017-08-04 Kostiantyn Iusenko , John MacQuarrie

Tambara functors are an equivariant generalization of rings that appear as the homotopy groups of genuine equivariant commutative ring spectra. In recent work, Blumberg and Hill have studied the corresponding algebraic structures, called…

Algebraic Topology · Mathematics 2024-01-31 David Chan

For a profinite group $G$ we describe an abelian group $W_G(R; M)$ of $G$-typical Witt vectors with coefficients in an $R$-module $M$ (where $R$ is a commutative ring). This simultaneously generalises the ring $W_G(R)$ of Dress and…

Algebraic Topology · Mathematics 2025-09-16 Thomas Read

The purpose of this article is to prove some results on the Witt vectors of perfect $\mathbf{F}_p$-algebras. Let $A$ be a perfect $\mathbf{F}_p$-algebra for a prime integer $p$ and assume that $A$ has the property $\mathbf{P}$. Then does…

Commutative Algebra · Mathematics 2026-03-09 Kazuma Shimomoto

We classify actions of generalized Taft algebras on preprojective algebras of extended Dynkin quivers of type $A$. This may be viewed as an extension of the problem of classifying actions on the polynomial ring in two variables. In cases…

Rings and Algebras · Mathematics 2025-02-27 Jason Gaddis , Amrei Oswald

We give a concrete description of the category of etale algebras over the ring of Witt vectors of a given finite length with entries in an arbitrary ring. We do this not only for the classical p-typical and big Witt vector functors but also…

Algebraic Geometry · Mathematics 2015-12-15 James Borger

Building on work of Hill, Hoyer and Mazur we propose an equivariant version of a Loday construction for $G$-Tambara functors where $G$ is an arbitrary finite group. For any finite simplicial $G$-set and any $G$-Tambara functor, our Loday…

Algebraic Topology · Mathematics 2025-07-08 Ayelet Lindenstrauss , Birgit Richter , Foling Zou

For every profinite group $G$, we construct two covariant functors $\Delta_G$ and ${\bf {\mathcal {AP}}}_G$ from the category of commutative rings with identity to itself, and show that indeed they are equivalent to the functor $W_G$…

Rings and Algebras · Mathematics 2007-05-23 Young-Tak Oh

We use Lazard's universal $\pi$-ring to construct a variation of the $\pi$-typical ramified Witt vector functors, which we call the Lazardian Witt vector functor. We then use the Lazardian Witt vector functor to construct the universal…

Number Theory · Mathematics 2025-10-27 Alexander Lai De Oliveira

We obtain results describing the behavior of the action of rotation generators on polynomials over a commutative ring. We also explore harmonic polynomials in a purely algebraic setting.

Representation Theory · Mathematics 2021-01-11 Keith Conrad , Ambar N. Sengupta

This is an account of the algebraic geometry of Witt vectors and arithmetic jet spaces. The usual, "p-typical" Witt vectors of p-adic schemes of finite type are already reasonably well understood. The main point here is to generalize this…

Algebraic Geometry · Mathematics 2015-12-15 James Borger

We define Bernstein-Gelfand-Ponomarev reflection functors in the cluster categories of hereditary algebras. They are triangle equivalences which provide a natural quiver realization of the "truncated simple reflections" on the set of almost…

Representation Theory · Mathematics 2007-05-23 Bin Zhu

For a finite group $G$, a Tambara functor on $G$ is regarded as a $G$-bivariant analog of a commutative ring. In this analogy, previously we have defined an ideal of a Tambara functor. In this article, we will demonstrate a calculation of…

Group Theory · Mathematics 2013-01-09 Hiroyuki Nakaoka

We study selfadjoint functors acting on categories of finite dimensional modules over finite dimensional algebras with an emphasis on functors satisfying some polynomial relations. Selfadjoint functors satisfying several easy relations, in…

Representation Theory · Mathematics 2011-09-08 Troels Agerholm , Volodymyr Mazorchuk

For a not-necessarily commutative ring R we define an abelian group W(R;M) of Witt vectors with coefficients in an R-bimodule M. These groups generalize the usual big Witt vectors of commutative rings and we prove that they have analogous…

K-Theory and Homology · Mathematics 2020-02-06 Emanuele Dotto , Achim Krause , Thomas Nikolaus , Irakli Patchkoria

The ring of Witt vectors $\mathbb{W} R$ over a base ring $R$ is an important tool in algebraic number theory and lies at the foundations of modern $p$-adic Hodge theory. $\mathbb{W} R$ has the interesting property that it constructs a ring…

Logic in Computer Science · Computer Science 2020-12-24 Johan Commelin , Robert Y. Lewis

A pair of adjoint functors $(F,G)$ is called a Frobenius pair of the second type if $G$ is a left adjoint of $\beta F\alpha$ for some category equivalences $\alpha$ and $\beta$. Frobenius ring extensions of the second kind provide examples…

Rings and Algebras · Mathematics 2007-05-23 S. Caenepeel , E. De Groot , G. Militaru

A functor on compact Hausdorf spaces is constructed as the sum of certain equivariant K-theory groups. It is shown that the functor takes values in lambda-rings and satisfies a Thom isomorphism. In the case that the space is a CW-complex…

Algebraic Topology · Mathematics 2013-09-18 Joseph C. Johnson

In this paper we study the adjoint functors between the category of Rota-Baxter algebras and the categories of dendriform dialgebras and trialgebras. In analogy to the well-known theory of the adjoint functor between the category of…

Rings and Algebras · Mathematics 2007-10-25 Kurusch Ebrahimi-Fard , Li Guo

For a "genuine" equivariant commutative ring spectrum $R$, $\pi_0(R)$ admits a rich algebraic structure known as a Tambara functor. This algebraic structure mirrors the structure on $R$ arising from the existence of multiplicative norm…

Algebraic Topology · Mathematics 2018-03-16 Andrew J. Blumberg , Michael A. Hill