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In this paper we produce infinite families of counterexamples to Jantzen's question posed in 1980 on the existence of Weyl $p$-filtrations for Weyl modules for an algebraic group and Donkin's Tilting Module Conjecture formulated in 1990.…

Representation Theory · Mathematics 2023-11-14 Christopher P. Bendel , Daniel K. Nakano , Cornelius Pillen , Paul Sobaje

In a sequence of four papers, we prove the following results (via a unified approach) for all sufficiently large $n$: (i) [1-factorization conjecture] Suppose that $n$ is even and $D\geq 2\lceil n/4\rceil -1$. Then every $D$-regular graph…

Combinatorics · Mathematics 2014-10-24 Béla Csaba , Daniela Kühn , Allan Lo , Deryk Osthus , Andrew Treglown

We improve the algebraic methods of Abhyankar for the Jacobian Conjecture in dimension two and describe the shape of possible counterexamples. We give an elementary proof of the result of Heitmann, which states that gcd(deg(P),deg(Q)) is…

Commutative Algebra · Mathematics 2016-06-01 Jorge A. Guccione , Juan J. Guccione , Christian Valqui

Hans J. Zassenhaus conjectured that for any unit $u$ of finite order in the integral group ring of a finite group $G$ there exists a unit $a$ in the rational group algebra of $G$ such that $a^{-1}\cdot u \cdot a=\pm g$ for some $g\in G$. We…

Rings and Algebras · Mathematics 2017-11-21 Florian Eisele , Leo Margolis

A central open question in extremal design theory is Nash-Williams' Conjecture from 1970 that every $K_3$-divisible graph on $n$ vertices (for $n$ large enough) with minimum degree at least $3n/4$ has a $K_3$-decomposition. A folklore…

Combinatorics · Mathematics 2026-03-19 Michelle Delcourt , Cicely Henderson , Thomas Lesgourgues , Luke Postle

We classify all pairs (G,V) with G a closed subgroup in a classical group with natural module V over the complex numbers such that G has the same composition factors on the kth tensor power of V, for a fixed (small) k. In particular, we…

Group Theory · Mathematics 2007-05-23 Robert M. Guralnick , Pham Huu Tiep

Let $S=(a_1)\cdots(a_k)$ be a minimal zero-sum sequence over a finite cyclic group $G$. The index conjecture states that if $k=4$ and $\gcd(|G|,6)=1$, then $S$ has index 1. In this note we study the index conjecture and connect it to a…

Number Theory · Mathematics 2016-06-07 Fan Ge

This is the final paper in the series of five, in which we prove the geometric Langlands conjecture (GLC). We conclude the proof of GLC by showing that there exists a unique (up to tensoring up by a vector space) Hecke eigensheaf…

Algebraic Geometry · Mathematics 2026-01-19 Dennis Gaitsgory , Sam Raskin

The symmetries described by Pin groups are the result of combining a finite number of discrete reflections in (hyper)planes. The current work shows how an analysis using geometric algebra provides a picture complementary to that of the…

Mathematical Physics · Physics 2025-10-16 Martin Roelfs , Steven De Keninck

Minimum numbers measure the obstruction to removing coincidences of two given maps (between smooth manifolds M and N of dimensions m and n, resp.). In this paper we compare them to four distinct types of Nielsen numbers. These agree with…

Algebraic Topology · Mathematics 2013-05-09 Ulrich Koschorke

In a sequence of four papers, we prove the following results (via a unified approach) for all sufficiently large $n$: (i) [1-factorization conjecture] Suppose that $n$ is even and $D \geq 2\lceil n/4\rceil -1$. Then every $D$-regular graph…

Combinatorics · Mathematics 2014-10-24 Béla Csaba , Daniela Kühn , Allan Lo , Deryk Osthus , Andrew Treglown

A longstanding conjecture of Seymour states that in every oriented graph there is a vertex whose second outneighbourhood is at least as large as its outneighbourhood. In this short note we show that, for any fixed $p\in[0,1/2)$, a.a.s.…

Combinatorics · Mathematics 2024-08-12 Alberto Espuny Díaz , António Girão , Bertille Granet , Gal Kronenberg

We prove a modified version for a conjecture of Weiss from 2004. Let $G$ be a semisimple real algebraic group defined over $\mathbb{Q}$, $\Gamma$ be an arithmetic subgroup of $G$. A trajectory in $G/\Gamma$ is divergent if eventually it…

Dynamical Systems · Mathematics 2021-05-07 Nattalie Tamam

We classify all the decomposition matrices of the generic Hecke algebras on 3 strands in characteristic 0. These are the generic Hecke algebras associated to the exceptional complex reflection groups $G_4$, $G_8$ and $G_{16}$. We prove that…

Representation Theory · Mathematics 2019-04-15 Eirini Chavli

The Huneke-Wiegand conjecture is a decades-long open question in commutative algebra. Garc\'ia-S\'anchez and Leamer showed that a special case of this conjecture concerning numerical semigroup rings $\Bbbk[\Gamma]$ can be answered in the…

Commutative Algebra · Mathematics 2024-04-22 Miguel Landeros , Christopher O'Neill , Roberto Pelayo , Karina Peña , James Ren , Brian Wissman

A conjecture of Hopkins (2018) posits that for certain high-dimensional hypothesis testing problems, no polynomial-time algorithm can outperform so-called "simple statistics", which are low-degree polynomials in the data. This conjecture…

Computational Complexity · Computer Science 2020-04-21 Justin Holmgren , Alexander S. Wein

Given a graph $H$, the maximal anti-Ramsey function $f(n,e,H)$ denotes the minimum integer $f$ for which there exists an $n$-vertex graph $G$ with at least $e$ edges admitting an edge-coloring with $f$ colors in which each copy of $H$ in…

Combinatorics · Mathematics 2026-03-20 Matija Bucic , Kaizhe Chen , Jie Ma

This work provides explicit characterizations and formulae for the minimal polynomials of a wide variety of structured $4\times 4$ matrices. These include symmetric, Hamiltonian and orthogonal matrices. Applications such as the complete…

Mathematical Physics · Physics 2010-10-12 Viswanath Ramakrishna , Yassmin Ansari , Fred Costa

Let H(G) be the Hecke algebra of a reductive p-adic group G. We formulate a conjecture for the ideals in the Bernstein decomposition of H(G). The conjecture says that each ideal is geometrically equivalent to an algebraic variety. Our…

Representation Theory · Mathematics 2007-05-23 Anne-Marie Aubert , Paul Baum , Roger Plymen

Let $\gamma(S_n)$ be the minimum number of proper subgroups $H_i$ of the symmetric group $S_n$ such that each element in $S_n$ lies in some conjugate of one of the $H_i.$ In this paper we conjecture that…

Group Theory · Mathematics 2013-10-11 Daniela Bubboloni , Cheryl E. Praeger , Pablo Spiga