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Ehrhart theory is the study of the enumeration of lattice points in lattice polytopes. Equivariant Ehrhart theory is a generalization of Ehrhart theory that takes into account the action of a finite group acting via affine transformations…

Combinatorics · Mathematics 2025-09-26 Alan Stapledon

Let $X$ be a variety over a complete nontrivially valued field $K$. We construct an algebraizable formal model for the analytification of $X$ in the case $X$ admits a closed embedding into a toric variety. By algebraizable we mean that the…

Algebraic Geometry · Mathematics 2023-03-27 Desmond Coles , Netanel Friedenberg

It is well known that classical varieties of $\Sigma$-algebras correspond bijectively to finitary monads on $\mathsf{Set}$. We present an analogous result for varieties of ordered $\Sigma$-algebras, i.e., classes presented by inequations…

Category Theory · Mathematics 2021-01-07 J. Adámek , M. Dostál , J. Velebil

We introduce a global equivariant refinement of algebraic K-theory; here `global equivariant' refers to simultaneous and compatible actions of all finite groups. Our construction turns a specific kind of categorical input data into a global…

Algebraic Topology · Mathematics 2022-07-05 Stefan Schwede

We define varieties of algebras for an arbitrary endofunctor on a cocomplete category using pairs of natural transformations. This approach is proved to be equivalent to the one of equational classes defined by equation arrows. Free…

Category Theory · Mathematics 2009-04-13 Jan Pavlík

In the literature two notions of the word problem for a variety occur. A variety has a decidable word problem if every finitely presented algebra in the variety has a decidable word problem. It has a uniformly decidable word problem if…

Logic · Mathematics 2016-09-06 Alan H. Mekler , Evelyn Nelson , Saharon Shelah

Algebraic quantum field theory is an approach to relativistic quantum physics, notably the theory of elementary particles, which complements other modern developments in this field. It is particularly powerful for structural analysis but…

Mathematical Physics · Physics 2007-05-23 Detlev Buchholz

We show that a class of algebras is closed under the taking of homomorphic images and direct products if and only if the class consists of all algebras that satisfy a set of (generally simultaneous) equations. For classes of regular…

Group Theory · Mathematics 2022-06-23 Peter M Higgins , Marcel Jackson

We consider the equivalence of Lawvere theories and finitary monads on Set from the perspective of Endf(Set)-enriched category theory, where Endf(Set) is the category of finitary endofunctors of Set. We identify finitary monads with…

Category Theory · Mathematics 2013-07-12 Richard Garner

We adapt the classical framework of algebraic theories to work in the setting of (infinity,1)-categories developed by Joyal and Lurie. This gives a suitable approach for describing highly structured objects from homotopy theory. A central…

Algebraic Topology · Mathematics 2010-11-16 James Cranch

We introduce the concept of compact quantitative equational theory. A quantitative equational theory is defined to be compact if all its consequences are derivable by means of finite proofs. We prove that the theory of interpolative…

Logic in Computer Science · Computer Science 2026-03-03 Matteo Mio

The rational, real and complex numbers with their standard operations, including division, are partial algebras specified by the axiomatic concept of a field. Since the class of fields cannot be defined by equations, the theory of…

Rings and Algebras · Mathematics 2009-01-08 J. A. Bergstra , Y. Hirshfeld , J. V. Tucker

Quantitative algebras are $\Sigma$-algebras acting on metric spaces, where operations are nonexpanding. Mardare, Panangaden and Plotkin introduced 1-basic varieties as categories of quantitative algebras presented by quantitative equations.…

Category Theory · Mathematics 2026-02-06 J. Adámek , M. Dostál , J. Velebil

We provide a Kingman-like Theorem for arbitrary finite measures and a version of Birkhoff's Theorem for bounded observable. As an application, we show that Birkhoff's limit exists for some continuous observable, in an example of Bowen.

Dynamical Systems · Mathematics 2020-07-09 Vinicius Coelho , Luciana Salgado

An algebra is said to be \emph{$\tau$-tilting finite} provided it has only a finite number of $\tau$-rigid objects up to isomorphism. We associate a category to each such algebra. The objects are the wide subcategories of its category of…

Representation Theory · Mathematics 2020-12-21 Aslak Bakke Buan , Bethany Marsh

Under a minimum of assumptions, we develop in generality the basic theory of universal algebra in a symmetric monoidal closed category $\mathcal{V}$ with respect to a specified system of arities $j:\mathcal{J} \hookrightarrow \mathcal{V}$.…

Category Theory · Mathematics 2016-04-28 Rory B. B. Lucyshyn-Wright

We introduce the notion of clone algebra, intended to found a one-sorted, purely algebraic theory of clones. Clone algebras are defined by true identities and thus form a variety in the sense of universal algebra. The most natural clone…

Logic · Mathematics 2021-01-19 Antonio Bucciarelli , Antonino Salibra

We provide a Lawvere-style definition for partial theories, extending the classical notion of equational theory by allowing partially defined operations. As in the classical case, our definition is syntactic: we use an appropriate class of…

Logic in Computer Science · Computer Science 2020-11-16 Ivan Di Liberti , Fosco Loregian , Chad Nester , Paweł Sobociński

A coset relation algebra is one embeddable into some full coset relation algebra, the latter is an algebra constructed from a system of groups, a coordinated system of isomorphisms between quotients of these groups, and a system of cosets…

Logic · Mathematics 2025-02-12 Steven Givant , Hajnal Andréka

From algebraic geometry perspective database relations are succinctly defined as Finite Varieties. After establishing basic framework, we give analytic proof of Heath theorem from Database Dependency theory. Next, we leverage…

Databases · Computer Science 2017-12-13 Vadim Tropashko