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We call a finite, spanning set of a semi-simple real Lie algebra a distinguished set if it satisfies the following property: The Lie bracket of any two elements out of the set is, up to some constant, another element in the set; conversely,…

Rings and Algebras · Mathematics 2020-04-28 Xudong Chen , Bahman Gharesifard

In finite group theory, studying the prime graph of a group has been an important topic for almost the past half-century. Recently, prime graphs of solvable groups have been characterized in graph theoretical terms only. This now allows the…

Combinatorics · Mathematics 2020-11-19 Chris Florez , Jonathan Higgins , Kyle Huang , Thomas Michael Keller , Dawei Shen

Results about the following classes of finite-dimensional Lie algebras over a field of characteristic zero are presented: anisotropic (i.e., Lie algebras for which each adjoint operator is semisimple), regular (i.e., Lie algebras in which…

Rings and Algebras · Mathematics 2014-08-14 Pasha Zusmanovich

We use homotopy theory to define certain rational coefficients characteristic numbers with integral values, depending on a given prime number q and positive integer t. We prove the first nontrivial degree formula and use it to show that…

Algebraic Topology · Mathematics 2009-03-26 Simone Borghesi

We provide a clarification of the classification of two-dimensional algebras over an arbitrary base field. Using this clarification, we determine the number of non-isomorphic two-dimensional algebras over a finite field.

Rings and Algebras · Mathematics 2026-05-26 U. Bekbaev

Looking in positive characteristic for failures of the Bertini-Sard theorem, we determine, up to birational equivalence, the separable proper morphisms of smooth algebraic varieties in characteristic two, whose fibres are non-smooth curves…

Algebraic Geometry · Mathematics 2016-05-04 Alejandro Simarra Cañate , Karl-Otto Stöhr

We develop a noncompact version of the Hopf maps based on the split algebras. The split algebras consist of three species: split-complex numbers, split quaternions, and split octonions. They correspond to three noncompact Hopf maps that…

Mathematical Physics · Physics 2014-11-18 Kazuki Hasebe

We prove that there exists uncountably many pairwise disjoint open subsets of the Gelfand space of the measure algebra on any locally compact non-discrete abelian group which shows that this space is not separable (in fact, we prove this…

Functional Analysis · Mathematics 2017-05-17 P. Ohrysko , M. Wojciechowski , Colin C. Graham

We introduce and investigate the solvable graph $\Gamma_\mathfrak{S}(L)$ of a finite-dimensional Lie algebra $L$ over a field $F$. The vertices are the elements outside the solvabilizer $\sol(L)$, and two vertices are adjacent whenever they…

Rings and Algebras · Mathematics 2025-11-12 David Towers , Ismael Gutierrez , Luis Fernandez

At an elementary level, we present some non-perturbative aspects of non-abelian gauge theories in four dimensional space-time. Some rigorous results have been obtained in the framework of supersymmetric theories, and a very rich physics…

High Energy Physics - Phenomenology · Physics 2007-05-23 Frank Ferrari

The genus gen(D) of a finite-dimensional central division algebra D over a field F is defined as the collection of classes [D'] in the Brauer group Br(F), where D' is a central division F-algebra having the same maximal subfields as D. For…

Rings and Algebras · Mathematics 2014-07-21 Sergey V. Tikhonov

For the simple Bratteli diagrams B where there is a single edge connecting any two vertices in consecutive levels, we show that a random order has uncountably many infinite paths if and only if the growth rate of the level-n vertex sets is…

Dynamical Systems · Mathematics 2016-06-13 Jeannette Janssen , Anthony Quas , Reem Yassawi

I show that quasidiagonality and AF embeddability are equivalent properties for traceless $\mathrm C^\ast$-algebras and are characterised in terms of the primitive ideal space. For nuclear $\mathrm C^\ast$-algebras the same characterisation…

Operator Algebras · Mathematics 2019-12-24 James Gabe

We consider the problem of identifying exactly which AF-algebras are isomorphic to a graph C*-algebra. We prove that any separable, unital, Type I C*-algebra with finitely many ideals is isomorphic to a graph C*-algebra. This result allows…

Operator Algebras · Mathematics 2013-08-26 Soren Eilers , Takeshi Katsura , Efren Ruiz , Mark Tomforde

We try to classify Hopf algebras with the Chevalley property according to their derived representation type. We show that a finite-dimensional indecomposable non-semisimple Hopf algebra $H$ with the Chevalley property is derived discrete if…

Quantum Algebra · Mathematics 2024-12-12 Jing Yu , Gongxiang Liu

Happel and Seidel gave a classification of piecewise hereditary Nakayama algebras, where the relations are given by some power of the radical. Here we explore what happens for general relations. We develop techniques for showing that a…

Representation Theory · Mathematics 2023-10-13 Didrik Fosse , Steffen Oppermann , Torkil Stai

We define a normal graph algebra modeled on algebras used in genetics. Although the algebra does not always determine its graph, it often highlights special features. After developing basic properties of the algebra, we examine those of…

Combinatorics · Mathematics 2023-05-23 Harold N. Ward

Evolution algebras are non-associative algebras that describe non-Mendelian hereditary processes and have connections with many other areas. In this paper we obtain necessary and sufficient conditions for a given algebra $A$ to be an…

Rings and Algebras · Mathematics 2021-02-10 Miguel D. Bustamante , Pauline Mellon , M. Victoria Velasco

Associative spectra of graph algebras are examined with the help of homomorphisms of DFS trees. Undirected graphs are classified according to the associative spectra of their graph algebras; there are only three distinct possibilities:…

Combinatorics · Mathematics 2021-05-20 Erkko Lehtonen , Tamás Waldhauser

It is well-known that every sharply 2-transitive group of characteristic 3 splits. Here we construct the first examples of non-split sharply 2-transitive groups in odd positive characteristic $p$, for sufficiently large primes $p$.…

Group Theory · Mathematics 2023-12-29 Marco Amelio , Simon André , Katrin Tent