Orbitopes

R Sanyal, F Sottile, B Sturmfels - Mathematika, 2011 - cambridge.org
An orbitope is the convex hull of an orbit of a compact group acting linearly on a vector
space. These highly symmetric convex bodies lie at the crossroads of several fields …

Metric thickenings, Borsuk–Ulam theorems, and orbitopes

H Adams, J Bush, F Frick - Mathematika, 2020 - Wiley Online Library
Thickenings of a metric space capture local geometric properties of the space. Here, we
exhibit applications of lower bounding the topology of thickenings of the circle and more …

The convex hull of a variety

K Ranestad, B Sturmfels - Notions of Positivity and the Geometry of …, 2011 - Springer
The Convex Hull of a Variety Page 1 Trends in Mathematics, 331–344 The Convex Hull of a
Variety Kristian Ranestad and Bernd Sturmfels Abstract. We present a characterization, in …

Moment curves and cyclic symmetry for positive Grassmannians

SN Karp - Bulletin of the London Mathematical Society, 2019 - Wiley Online Library
We show that for each k and n, the cyclic shift map on the Grassmannian Gr k, n (C) has
exactly nk fixed points. There is a unique totally nonnegative fixed point, given by taking n …

Embedding-Projection Correspondences for the estimation of the Gromov-Hausdorff distance

F Mémoli, ZT Smith - arXiv preprint arXiv:2407.03295, 2024 - arxiv.org
This writeup describes ongoing work on designing and testing a certain family of
correspondences between compact metric spaces that we call\emph {embedding-projection …

Neighborliness of the symmetric moment curve

A Barvinok, SJ Lee, I Novik - Mathematika, 2013 - Wiley Online Library
We consider the convex hull ℬk of the symmetric moment curve Uk (t)=(cos t, sin t, cos 3t, sin
3t,…, cos (2k− 1) t, sin (2k− 1) t) in ℝ2k, where t ranges over the unit circle. The curve Uk (t) …

Topological, geometric, and combinatorial aspects of metric thickenings

JE Bush - 2021 - search.proquest.com
The geometric realization of a simplicial complex equipped with the 1-Wasserstein metric of
optimal transport is called a simplicial metric thickening. We describe relationships between …

A tale of centrally symmetric polytopes and spheres

I Novik - Recent trends in algebraic combinatorics, 2019 - Springer
This paper is a survey of recent advances as well as open problems in the study of face
numbers of centrally symmetric simplicial polytopes and spheres. The topics discussed …

Faces for two qubit separable states and the convex hulls of trigonometric moment curves

SH Kye - arXiv preprint arXiv:1302.2226, 2013 - arxiv.org
We analyze the facial structures of the convex set consisting of all two qubit separable
states. One of faces is a four dimensional convex body generated by the trigonometric …

Face numbers: the upper bound side of the story

I Novik - Proc. Int. Cong. Math, 2022 - content.ems.press
We survey the theory of face numbers of simplicial complexes through the lens of upper
bound type results and neighborliness. We focus on the classes of polytopes, simplicial …