We define and study the totally nonnegative part of the Chow quotient of the Grassmannian,
or more simply the nonnegative configuration space. This space has a natural stratification …

A bstract We study tropical Grassmanians Tr (k, n) in relation to cluster algebras, and assess
their applicability to n-particle amplitudes for n= 7, 8. In\(\mathcal {N}\)= 4 super Yang-Mills …

A bstract We further exploit the relation between tropical Grassmannians and Gr (4, n)
cluster algebras in order to make and refine predictions for the singularities of scattering …

A flag positroid of ranks $\boldsymbol {r}:=(r_1<\dots< r_k) $ on $[n] $ is a flag matroid that
can be realized by a real $ r_k\times n $ matrix $ A $ such that the $ r_i\times r_i $ minors of …

A bstract We describe a family of tropical fans related to Grassmannian cluster algebras.
These fans are related to the kinematic space of massless scattering processes in a number …

A bstract In this paper, we study a novel behavior developed by certain tree-level scalar
scattering amplitudes, including the biadjoint, NLSM, and special Galileon, when a subset of …

This is a preliminary draft of Chapter 7 of our forthcoming textbook" Introduction to Cluster
Algebras." Chapters 1-3 have been posted as arXiv: 1608.05735. Chapters 4-5 have been …

A bstract We continue the study of positive geometries underlying the Grassmannian string
integrals, which are a class of “stringy canonical forms”, or stringy integrals, over the positive …

Tropical geometry, quantum affine algebras, and scattering amplitudes - IOPscience Skip to
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Introduction to Cluster Algebras Chapter 7 Page 1 Introduction to Cluster Algebras Chapter 7
(preliminary version) Sergey Fomin Lauren Williams Andrei Zelevinsky Page 2 Preface This is a …