activity
20232026
most citedEquality cases of the Alexandrov--Fenchel inequality are not in the polynomial hierarchy

8 citations · 14 across the 10 of their papers we have counts for

collaborators

11 papers

math.CO2026

Breaking the Infinite Barrier in the -- Conjecture

Max Aires, Swee Hong Chan, Igor Pak +1

The balance constant is a poset parameter measuring how well random linear extensions can be split according to their relative order on two elements. We give an -impro…

math.CO2026

On the largest Littlewood--Richardson coefficient

Igor Pak, Daniel Soskin

We study partitions which attain the largest Littlewood-Richardson coefficient. More precisely, we prove that the largest is attained at partitions such that $μ\subseteq…

math.QA2026

Quantum determinants in polynomial time

Igor Pak, Daniel Soskin

We give an algebraic branching program of polynomial size which computes Cayley determinant of right quantum matrices. This is a rare example of an efficient computation of a nonco…

math.CO2026

Equality conditions for correlation inequalities

Swee Hong Chan, Igor Pak

We prove equality conditions for the Ahlswede--Daykin (AD) inequality and the Fortuin--Kasteleyn--Ginibre (FKG) inequality. We then present a number of applications and special cas…

math.CO2026

Correlation inequalities for Schur positivity

Swee Hong Chan, Hong Chen, Igor Pak +1

We generalize the Ahlswede--Daykin inequality (1978) to a Schur positive \emph{ADS inequality}, which also contains the Lam--Postnikov--Pylyavskyy inequality (2007) as a special ca…

math.CO2025

Effective resistance in planar graphs and continued fractions

Swee Hong Chan, Alex Kontorovich, Igor Pak

For a simple graph and edge , the effective resistance is defined as a ratio , where denotes the number of spanning trees in . We r…

math.CO2024

Spanning trees and continued fractions

Swee Hong Chan, Alex Kontorovich, Igor Pak

We prove the exponential growth of the cardinality of the set of numbers of spanning trees in simple (and planar) graphs on vertices, answering a question of Sedláček from 1969…

math.CO2024

Equality cases of the Stanley--Yan log-concave matroid inequality

Swee Hong Chan, Igor Pak

The \emph{Stanley--Yan} (SY) \emph{inequality} gives the ultra-log-concavity for the numbers of bases of a matroid which have given sizes of intersections with fixed disjoint s…

math.CO2024★ 3 cited

Linear extensions and continued fractions

Swee Hong Chan, Igor Pak

We introduce several new constructions of finite posets with the number of linear extensions given by generalized continued fractions. We apply our results to the problem of the mi…

math.CO2023★ 3 cited

Linear extensions of finite posets

Swee Hong Chan, Igor Pak

We give a broad survey of inequalities for the number of linear extensions of finite posets. We review many examples, discuss open problems, and present recent results on the subje…

math.CO2023★ 8 cited

Equality cases of the Alexandrov--Fenchel inequality are not in the polynomial hierarchy

Swee Hong Chan, Igor Pak

Describing the equality conditions of the Alexandrov--Fenchel inequality has been a major open problem for decades. We prove that in the case of convex polytopes, this description…