Year: 2026
Type: preprint
Abstract: Ext^1 between simple restricted modules for all four Cartan-type families over an algebraically closed field of characteristic p >= 5, answering Problem 4 of Benkart and Feldvoss at zero p-character. The exceptional subquivers are given in closed form. Neither the trivial module nor any nontrivial exceptional simple has a self-extension, and the Ext^1 quiver of S(3;1)^(1) at p = 7 has 49 vertices, 386 arrows and no loops.
Source: arXiv (Cornell University)
Author: Ma, Chao
Language: English
Topic: Advanced Topics in Algebra
Subfield: Algebra and Number Theory
Field: Mathematics
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7207633788