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Related papers: On quasi-thin association schemes

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Association schemes on triples (ASTs) are 3-dimensional analogues of classical association schemes. If a group acts two-transitively on a set, the orbits of the action induced on the triple Cartesian product of that set yields an AST. By…

Combinatorics · Mathematics 2023-08-22 Dom Vito A. Briones

We define the intersection complex for the universal cover of a compact weakly special square complex and show that it is a quasi-isometry invariant. By using this quasi-isometry invariant, we study the quasi-isometric classification of…

Group Theory · Mathematics 2023-09-07 Sangrok Oh

This paper is concerned with the characterizations of quasi self-adjoint extensions of a class of formally non-self-adjoint discrete Hamiltonian systems. Some properties of the solutions and the characterization of the minimal linear…

Spectral Theory · Mathematics 2025-12-11 Guojing Ren , Guixin Xu

Let K be a discretly henselian field whose residue field is separably closed. Answering a question raised by G. Prasad, we show that a semisimple K-- group G is quasi-split if and only if it quasi--splits after a finite tamely ramified…

Group Theory · Mathematics 2017-07-12 Philippe Gille

An association scheme is called partially metric if it has a connected relation whose distance-two relation is also a relation of the scheme. In this paper we determine the symmetric partially metric association schemes with a multiplicity…

Combinatorics · Mathematics 2017-01-13 Edwin R. van Dam , Jack H. Koolen , Jongyook Park

Let \mathbb{F}_q^{n+l} denote the (n+l)-dimensional singular linear space over a finite field \mathbb{F}_q. For a fixed integer m\leq\min\{n,l\}, denote by \mathcal{L}^m_o(\mathbb{F}_q^{n+l}) the set of all subspaces of type (t,t_1), where…

Combinatorics · Mathematics 2013-09-23 Zhang Baohuan , Yue Mengtian , Li Zengti

In this paper, we continue with the results in \cite{Pg} and compute the group of quasi-isometries for a subclass of split solvable unimodular Lie groups. Consequently, we show that any finitely generated group quasi-isometric to a member…

Metric Geometry · Mathematics 2010-02-25 Irine Peng

A closed subscheme of codimension two $T \subset P^2$ is a quasi complete intersection (q.c.i.) of type $(a,b,c)$ if there exists a surjective morphism $\mathcal{O} (-a) \oplus \mathcal{O} (-b) \oplus \mathcal{O} (-c) \to \mathcal{I} _T$.…

Algebraic Geometry · Mathematics 2019-01-04 Philippe Ellia

In a digraph, a quasi-kernel is a subset of vertices that is independent and such that the shortest path from every vertex to this subset is of length at most two. The ``small quasi-kernel conjecture,'' proposed by Erd\H{o}s and Sz\'ekely…

Combinatorics · Mathematics 2024-02-27 Hélène Langlois , Frédéric Meunier , Romeo Rizzi , Stéphane Vialette , Yacong Zhou

An association scheme is called amorphic if every possible fusion of relations gives rise to a fusion scheme. We call a pair of relations fusing if fusing that pair gives rise to a fusion scheme. We define the fusing-relations graph on the…

Combinatorics · Mathematics 2025-03-07 Edwin R. van Dam , Jack H. Koolen , Yanzhen Xiong

An approximation scheme is a family of homogeneous subsets $(A_n)$ of a quasi-Banach space $X$, such that $A_1 \subsetneq A_2 \subsetneq ... \subsetneq X$, $A_n + A_n \subset A_{K(n)}$, and $\bar{\cup_n A_n} = X$. Continuing the line of…

Classical Analysis and ODEs · Mathematics 2010-10-26 J. M. Almira , T. Oikhberg

A semisimple element $s$ of a connected reductive group $G$ is said {\it quasi-isolated} (respectively {\it isolated}) if $C_G(s)$ (respectively $C_G^0(s)$) is not contained in a Levi subgroup of a proper parabolic subgroup of $G$. We study…

Group Theory · Mathematics 2007-05-23 Cédric Bonnafé

We prove that a harmonic quasiconformal mapping defined on a finitely connected domain in the plane, all of whose boundary components are either points or quasicircles, admits a quasiconformal extension to the whole plane if its Schwarzian…

Complex Variables · Mathematics 2021-02-05 Iason Efraimidis

A quasi-schemoid is a small category with a particular partition of the set of morphisms. We define a homotopy relation on the category of quasi-schemoids and study its fundamental properties. As a homotopy invariant, the homotopy set of…

Category Theory · Mathematics 2014-10-27 Katsuhiko Kuribayashi

All quasi-affine connected Generalized Dynkin Diagram with rank $= 3$ and $2$ are found. All quasi-affine Nichols (Lie braided) algebras with rank $ 3$ and $2$ are also found.

Quantum Algebra · Mathematics 2024-06-21 Zhengtang Tan , Shouchuan Zhang

We show that every quasitrivial n-ary semigroup is reducible to a binary semigroup, and we provide necessary and sufficient conditions for such a reduction to be unique. These results are then refined in the case of symmetric n-ary…

Rings and Algebras · Mathematics 2019-09-24 Miguel Couceiro , Jimmy Devillet

We give a method of constructing maps between tubular groups inductively according to a set of strategies. This map will be a quasi-isometry exactly when the set of strategies is consistent. Conversely, if there exists a quasi-isometry…

Group Theory · Mathematics 2010-07-20 Christopher H Cashen

In this article, we investigate the existence and schurity problem of association schemes whose thin residues are isomorphic to an elementary abelian $p$-group of rank $2$.

Combinatorics · Mathematics 2015-11-03 Mitsugu Hirasaka , Kijung Kim

We generalize the notion of quasielliptic curves, which have infinitesimal symmetries and exist only in characteristic two and three, to a remarkable hierarchy of regular curves having infinitesimal symmetries, defined in all…

Algebraic Geometry · Mathematics 2026-05-27 Cesar Hilario , Stefan Schröer

Relying on rays, we search for submodules of a module V over a supertropical semiring on which a given anisotropic quadratic form is quasilinear. Rays are classes of a certain equivalence relation on V, that carry a notion of convexity,…

Rings and Algebras · Mathematics 2018-07-10 Zur Izhakian , Manfred Knebusch