activity
20162025
most citedDilated Floor Functions That Commute

9 citations · 24 across the 17 of their papers we have counts for

collaborators

18 papers

q-bio.PE2025★ 1 cited

Vector encoding of phylogenetic trees by ordered leaf attachment

Harry Richman, Cheng Zhang, Frederick A. Matsen

As part of work to connect phylogenetics with machine learning, there has been considerable recent interest in vector encodings of phylogenetic trees. We present a simple new "orde…

stat.ML2025

PhyloVAE: Unsupervised Learning of Phylogenetic Trees via Variational Autoencoders

Tianyu Xie, Harry Richman, Jiansi Gao +2

Learning informative representations of phylogenetic tree structures is essential for analyzing evolutionary relationships. Classical distance-based methods have been widely used t…

math.CO2024

Principal minors of tree distance matrices

Harry Richman, Farbod Shokrieh, Chenxi Wu

We prove that the principal minors of the distance matrix of a tree satisfy a combinatorial expression involving counts of rooted spanning forests of the underlying tree. This gene…

math.NT2024

The family of -floor quotient partial orders

Jeffrey C. Lagarias, David Harry Richman

An approximate divisor order is a partial order on the positive integers that refines the divisor order and is refined by the additive total order. A previous paper…

math.CO2024

A Ricci flow on graphs from effective resistance

Aleyah Dawkins, Vishal Gupta, Mark Kempton +4

In this paper, we introduce a new notion of curvature on the edges of a graph that is defined in terms of effective resistances. We call this the Ricci--Foster curvature. We study…

math.CO2024★ 1 cited

Node resistance curvature in Cartesian graph products

Aleyah Dawkins, Vishal Gupta, Mark Kempton +4

Devriendt and Lambiotte recently introduced the \emph{node resistance curvature}, a notion of graph curvature based on the effective resistance matrix. In this paper, we begin the…

math.NT2024

The Möbius function of the poset of triangular numbers under divisibility

Rohan Pandey, Harry Richman

This paper analyzes the Möbius () function defined on the partially ordered set of triangular numbers () under the divisibility relation. We make conjectures o…

math.CO2023

Counting two-forests and random cut size via potential theory

Harry Richman, Farbod Shokrieh, Chenxi Wu

We prove a lower bound on the number of spanning two-forests in a graph, in terms of the number of vertices, edges, and spanning trees. This implies an upper bound on the average c…

math.AG2023

Tropical Weierstrass points and Weierstrass weights

Omid Amini, Lucas Gierczak, Harry Richman

In this paper, we study tropical Weierstrass points. These are the analogues for tropical curves of ramification points of line bundles on algebraic curves. For a divisor on a trop…

math.NT2023

Lower rational approximations and Farey staircases

David Harry Richman

For a real number , call the -th lower rational approximation of . We study the functions defined by taking the cumulative average of the firs…

math.NT2022★ 1 cited

The floor quotient partial order

Jeffery C. Lagarias, David Harry Richman

A positive integer is a floor quotient of if there is a positive integer such that . The floor quotient relation defines a partial order on the…

math.AG2021★ 1 cited

The tropical Manin-Mumford conjecture

David Harry Richman

In analogy with the Manin-Mumford conjecture for algebraic curves, one may ask how a metric graph under the Abel-Jacobi embedding intersects torsion points of its Jacobian. We show…

math.GT2021

Counting Tripods on the Torus

Jayadev S. Athreya, David Aulicino, Harry Richman

Motivated by the problem of counting finite BPS webs, we count certain immersed metric graphs, tripods, on the flat torus. Classical Euclidean geometry turns this into a lattice po…

math.NT2020★ 2 cited

Derangements and the -adic incomplete gamma function

Andrew O'Desky, David Harry Richman

We introduce a -adic analogue of the incomplete gamma function. We also introduce quantities (-values) associated to a function on natural numbers and prove a new characteriz…

math.NT2019★ 3 cited

Dilated floor functions having nonnegative commutator II. Negative dilations

Jeffrey C. Lagarias, D. Harry Richman

This paper completes the classification of the set of all real parameter pairs such that the dilated floor functions , $f_β(x) = \lfloor{βx…

math.AG2018★ 4 cited

The distribution of Weierstrass points on a tropical curve

David Harry Richman

We show that on a metric graph of genus , a divisor of degree generically has Weierstrass points. For a sequence of generic divisors on a metric graph whose degre…

math.NT2018★ 2 cited

Dilated floor functions having nonnegative commutator I. Positive and mixed sign dilations

Jeffrey C. Lagarias, D. Harry Richman

In this paper and its sequel we classify the set of all real parameter pairs such that the dilated floor functions and $f_β(x) = \lfloor{β…

math.NT2016★ 9 cited

Dilated Floor Functions That Commute

Jeffrey C. Lagarias, Takumi Murayama, D. Harry Richman

We determine all pairs of real numbers such that the dilated floor functions and commute under composition, i.e., such that $\lfloo…