Asymptotic probability of irreducibles II: sequence
Thierry Monteil, Khaydar Nurligareev
TL;DR
The paper derives a complete asymptotic expansion for the probability that a large SEQ-decomposed object is irreducible or has a given number of SEQ-irreducible parts, for gargantuan labeled and unlabeled classes. It develops a unified framework based on gargantuan sequences, Bender's theorem, and the lift operation to handle non-stable decompositions, and applies it to a broad spectrum of combinatorial constructions including tournaments, multitournaments, permutations, linear orders, and perfect matchings. Key contributions include explicit coefficient formulas d_{k,m} and their unlabeled analogues, and a demonstration of how these coefficients decompose into combinatorial structures via inclusion-exclusion and lifting. The results illuminate when SEQ-based irreducibility probabilities admit combinatorial interpretations and suggest directions for extending the approach to other decompositions and to anti-SEQ formulations.
Abstract
This paper is devoted to the structure of the complete asymptotic expansion of the probability that a large combinatorial object is irreducible or consists of a given number of irreducible parts, where irreducibility is understood in terms of combinatorial construction SEQ, labeled or unlabeled. We show that for rapidly growing (i.e. gargantuan) combinatorial classes, the coefficients that appear in this expansion are integers and can be interpreted as linear combinations of the counting sequences of three closely related combinatorial classes. We apply this general asymptotic result to labeled and unlabeled (multi-)tournaments, as well as to (multi-)permutations and (multi-)matchings. We also explore the limits of our approach with respect to other combinatorial constructions.
