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Related papers: Flow polytopes with Catalan volumes

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In this paper we study an alternating sign matrix analogue of the Chan-Robbins-Yuen polytope, which we call the ASM-CRY polytope. We show that this polytope has Catalan many vertices and its volume is equal to the number of standard Young…

Combinatorics · Mathematics 2019-01-16 Karola Mészáros , Alejandro H. Morales , Jessica Striker

We prove a conjecture of Meszaros and Morales on the volume of a flow polytope. Independently from our work, Zeilberger sketched a proof of their conjecture. In fact, our proof is the same as Zeilberger's proof. The purpose of this note is…

Combinatorics · Mathematics 2017-04-12 Jang Soo Kim

The goal of this paper is to study Yamabe flow on a complete Riemannian manifold of bounded geometry with possibly infinite volume. In the case of infinite volume, standard volume normalization of the Yamabe flow fails and the flow may not…

Differential Geometry · Mathematics 2022-10-17 Bruno Caldeira , Luiz Hartmann , Boris Vertman

We introduce a new broadly unifying family of combinatorial objects, which we call permutation flows, associated to an acyclic directed graph $G$ together with a framing $F$. This new family is combinatorially rich and contains as special…

Combinatorics · Mathematics 2025-12-04 Rafael S. González D'León , Christopher R. H. Hanusa , Martha Yip

The aim of this work is to introduce several different volume computation methods of the graph polytope associated with various type of finite simple graphs. Among them, we obtained the recursive volume formula (RVF) that is fundamental and…

Combinatorics · Mathematics 2015-07-29 Daeseok Lee , Hyeong-Kwan Ju

Let n >= 2 be an integer and consider the set T_n of n by n permutation matrices pi for which pi_{ij}=0 for j>=i+2. In this paper we study the convex hull of T_n, which we denote by P_n. P_n is a polytope of dimension binom{n}{2}. Our main…

Combinatorics · Mathematics 2007-05-23 Clara S. Chan , David P. Robbins , David S. Yuen

We present a framework for modeling complex, high-dimensional distributions on convex polytopes by leveraging recent advances in discrete and continuous normalizing flows on Riemannian manifolds. We show that any full-dimensional polytope…

Machine Learning · Computer Science 2025-03-18 Tomek Diederen , Nicola Zamboni

We present an explicit closed-form formula for the vertices of the classical cut polytope $\operatorname{CUT}(n)$, defined as the convex hull of cut vectors of the complete graph $K_n$. Our derivation proceeds via a related polytope,…

Combinatorics · Mathematics 2025-07-22 Nevena Marić

Steady fluid flows have very special topology. In this paper we describe necessary and sufficient conditions on the vorticity function of a 2D ideal flow on a surface with or without boundary, for which there exists a steady flow among…

Symplectic Geometry · Mathematics 2015-11-19 Anton Izosimov , Boris Khesin

In this note we introduce a family of polynomials on a matroid derived from chain Tutte polynomials which generalize the classic and ubiquitous characteristic polynomial. We show that the coefficients of these polynomials alternate and…

Combinatorics · Mathematics 2025-08-08 Gary Lazzaro , Max Wakefield , Jason Weiss

The cut polytope ${\rm CUT}(n)$ is the convex hull of the cut vectors in a complete graph with vertex set $\{1,\ldots,n\}$. It is well known in the area of combinatorial optimization and recently has also been studied in a direct relation…

Discrete Mathematics · Computer Science 2018-12-11 Nevena Maric

An extended formulation of a polytope is a linear description of this polytope using extra variables besides the variables in which the polytope is defined. The interest of extended formulations is due to the fact that many interesting…

Optimization and Control · Mathematics 2013-06-14 Samuel Fiorini , Kanstantsin Pashkovich

A $3$-dimensional nowhere-zero flow on a graph $G$ is a flow where each edge is assigned a $3$-dimensional vector with unit norm (which corresponds to the points of a $2$-dimensional unit sphere $S^2$). K. Jain posed two conjectures related…

Combinatorics · Mathematics 2026-03-25 Nikolay Ulyanov

We present exact calculations of flow polynomials $F(G,q)$ for lattice strips of various fixed widths $L_y$ and arbitrarily great lengths $L_x$, with several different boundary conditions. Square, honeycomb, and triangular lattice strips…

Statistical Mechanics · Physics 2007-05-23 Shu-Chiuan Chang , Robert Shrock

The Baldoni--Vergne volume and Ehrhart polynomial formulas for flow polytopes are significant in at least two ways. On one hand, these formulas are in terms of Kostant partition functions, connecting flow polytopes to this classical vector…

Combinatorics · Mathematics 2021-01-01 Kabir Kapoor , Karola Mészáros , Linus Setiabrata

We construct explicit combinatorial Bernoulli factories for the class of \emph{flow-based polytopes}; integral 0/1-polytopes defined by a set of network flow constraints. This generalizes the results of Niazadeh et al. (who constructed an…

Data Structures and Algorithms · Computer Science 2022-07-20 Rad Niazadeh , Renato Paes Leme , Jon Schneider

We study $2$-dimensional unit vector flows on graphs, that is, nowhere-zero flows that assign to each oriented edge a unit vector in $\mathbb R^{3}$. We give a new geometric characterization of $\mathbb S^{2}$-flows on cubic graphs. We also…

Combinatorics · Mathematics 2026-02-26 Hussein Houdrouge , Bobby Miraftab , Pat Morin

Let $G$ be a connected graph; denote by $\tau(G)$ the set of its spanning trees. Let $\mathbb F_q$ be a finite field, $s(\alpha,G)=\sum_{T\in\tau(G)} \prod_{e \in E(T)} \alpha_e$, where ${\alpha_e\in \mathbb F_q}$. Kontsevich conjectured in…

Combinatorics · Mathematics 2017-05-12 Eduard Yu. Lerner , Andrey P. Kuptsov , Sofya A. Mukhamedjanova

PQ-type adjacency polytopes $\nabla^{\rm PQ}_G$ are lattice polytopes arising from finite graphs $G$. There is a connection between $\nabla^{\rm PQ}_G$ and the engineering problem known as power-flow study, which models the balance of…

Combinatorics · Mathematics 2023-07-14 Hidefumi Ohsugi , Akiyoshi Tsuchiya

Framing triangulations of unit flow polytopes have received a great deal of recent study with rich connections to various generalizations of Catalan and Cambrian combinatorics as well as volume and h*-polynomial formulas. This story has…

Combinatorics · Mathematics 2026-05-26 Jonah Berggren