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It is known how to compute the Zariski closure of a finitely generated monoid of matrices and, more generally, of a set of matrices specified by a regular language. This result was recently used to give a procedure to compute all polynomial…

Formal Languages and Automata Theory · Computer Science 2025-10-28 Rida Ait El Manssour , Mahsa Naraghi , Mahsa Shirmohammadi , James Worrell

We classify the pairs $(X,\pi)$, where $\pi\colon X\to S$ is a $\mathbb{P}^1$-bundle over a non-rational geometrically ruled surface $S$ and $\mathrm{Aut}^\circ(X)$ is relatively maximal, i.e., maximal with respect to the inclusion in the…

Algebraic Geometry · Mathematics 2026-05-19 Pascal Fong

We study pointwise-generalized-inverses of linear maps between C$^*$-algebras. Let $\Phi$ and $\Psi$ be linear maps between complex Banach algebras $A$ and $B$. We say that $\Psi$ is a pointwise-generalized-inverse of $\Phi$ if…

Operator Algebras · Mathematics 2017-03-31 Ahlem Ben Ali Essaleh , Antonio M. Peralta , María Isabel Ramírez

Let $\varphi\colon\Gamma\to G$ be a homomorphism of groups. In this paper we introduce the notion of a subnormal map (the inclusion of a subnormal subgroup into a group being a basic prototype). We then consider factorizations…

Group Theory · Mathematics 2014-05-02 Emmanuel D. Farjoun , Yoav Segev

In this work, linearized multivariate skew polynomials over division rings are introduced. Such polynomials are right linear over the corresponding centralizer and generalize linearized polynomial rings over finite fields, group rings or…

Rings and Algebras · Mathematics 2021-12-07 Umberto Martínez-Peñas

The present paper records more details of the relationship between primitive elements and palindromes in F_2, the free group of rank two. We characterise the conjugacy classes of primitive elements which contain palindromes as those which…

Group Theory · Mathematics 2019-02-07 Adam Piggott

To give vector-based representations of meaning more structure, one approach is to use positive semidefinite (psd) matrices. These allow us to model similarity of words as well as the hyponymy or is-a relationship. Psd matrices can be…

Computation and Language · Computer Science 2020-06-01 Gemma De las Cuevas , Andreas Klingler , Martha Lewis , Tim Netzer

We pursue the investigation of generalizations of the Pascal triangle based on binomial coefficients of finite words. These coefficients count the number of times a finite word appears as a subsequence of another finite word. The finite…

Combinatorics · Mathematics 2018-01-11 Manon Stipulanti

We prove that the generalized Thue-Morse word $\mathbf{t}_{b,m}$ defined for $b \geq 2$ and $m \geq 1$ as $\mathbf{t}_{b,m} = (s_b(n) \mod m)_{n=0}^{+\infty}$, where $s_b(n)$ denotes the sum of digits in the base-$b$ representation of the…

Combinatorics · Mathematics 2015-03-12 Štěpán Starosta

Most of the successful and predominant methods for bilingual lexicon induction (BLI) are mapping-based, where a linear mapping function is learned with the assumption that the word embedding spaces of different languages exhibit similar…

Computation and Language · Computer Science 2020-10-23 Tasnim Mohiuddin , M Saiful Bari , Shafiq Joty

We introduce a class of fixed points of primitive morphisms among aperiodic binary generalized pseudostandard words. We conjecture that this class contains all fixed points of primitive morphisms among aperiodic binary generalized…

Combinatorics · Mathematics 2017-01-18 Lubomira Dvorakova , Tereza Velka

A monoid is called special if it admits a presentation in which all defining relations are of the form $w = 1$. Every group is special, but not every monoid is special. In this article, we describe the language-theoretic properties of the…

Group Theory · Mathematics 2021-11-23 Carl-Fredrik Nyberg-Brodda

In 1999 Lyngs{\o} and Pedersen proposed a conjecture stating that every binary circular word of length $n$ with equal number of zeros and ones has an antipalindromic linear subsequence of length at least $\frac{2}{3}n$. No progress over a…

Formal Languages and Automata Theory · Computer Science 2019-01-23 Clemens Müllner , Andrew Ryzhikov

A graph G(V, E) is word-representable if there exists a word w over V such that distinct letters x and y alternate in w iff $xy \in E$. We introduce p-complete squares and p-complete square-free word-representable graphs. A word is…

Discrete Mathematics · Computer Science 2025-12-25 Biswajit Das , Ramesh Hariharasubramanian

The palindromic length of a finite word $w$ is defined as the minimal number of palindromes such that their product is $w$. Clearly, this function may take different values depending on if we consider $w$ as an element a free semigroup or…

Combinatorics · Mathematics 2025-12-12 Anna E. Frid

Many automatic theorem provers are restricted to untyped logics, and existing translations from typed logics are bulky or unsound. Recent research proposes monotonicity as a means to remove some clutter when translating monomorphic to…

Logic in Computer Science · Computer Science 2019-03-14 Jasmin Christian Blanchette , Sascha Böhme , Andrei Popescu , Nicholas Smallbone

The notion of a $p$-Riordan graph generalizes that of a Riordan graph, which, in turn, generalizes the notions of a Pascal graph and a Toeplitz graph. In this paper we introduce the notion of a $p$-Riordan word, and show how to encode…

Combinatorics · Mathematics 2020-09-04 Kittitat Iamthong , Ji-Hwan Jung , Sergey Kitaev

We consider Parikh images of languages accepted by non-deterministic finite automata and context-free grammars; in other words, we treat the languages in a commutative way --- we do not care about the order of letters in the accepted word,…

Formal Languages and Automata Theory · Computer Science 2010-03-23 Eryk Kopczyński

We prove that the class of finitely presented inverse monoids whose Sch\"utzenberger graphs are quasi-isometric to trees has a uniformly solvable word problem, furthermore, the languages of their Sch\"utzenberger automata are context-free.…

Group Theory · Mathematics 2022-11-18 Robert D. Gray , Pedro V. Silva , Nóra Szakács

We show that the number of length-n words over a k-letter alphabet having no even palindromic prefix is the same as the number of length-n unbordered words, by constructing an explicit bijection between the two sets. A slightly different…

Discrete Mathematics · Computer Science 2020-06-05 Daniel Gabric , Jeffrey Shallit