7 papers
Asymptotic tensor rank is characterized by polynomials
Matthias Christandl, Koen Hoeberechts, Harold Nieuwboer +2
Asymptotic tensor rank is notoriously difficult to determine. Indeed, determining its value for the matrix multiplication tensor would determine the matrix multiplicati…
On quantum functionals for higher-order tensors
Alonso Botero, Matthias Christandl, Thomas C. Fraser +2
Upper and lower quantum functionals, introduced by Christandl, Vrana and Zuiddam (STOC 2018, J. Amer. Math. Soc. 2023), are families of monotone functions of tensors indexed by a w…
Negative curvature obstructs the existence of good barriers for interior-point methods
Christopher Criscitiello, Harold Nieuwboer, Michael Walter
Interior-point methods (IPMs) are a cornerstone of Euclidean convex optimization, due to their strong theoretical guarantees and practical performance. Motivated by scaling problem…
Computing moment polytopes -- with a focus on tensors, entanglement and matrix multiplication
Maxim van den Berg, Matthias Christandl, Vladimir Lysikov +3
Tensors are fundamental in mathematics, computer science, and physics. Their study through algebraic geometry and representation theory has proved very fruitful in the context of a…
Self-concordant Schrödinger operators: spectral gaps and optimization without condition numbers
Sander Gribling, Simon Apers, Harold Nieuwboer +1
Spectral gaps play a fundamental role in many areas of mathematics, computer science, and physics. In quantum mechanics, the spectral gap of Schrödinger operators has a long histo…
Explicit non-free tensors
Maxim van den Berg, Matthias Christandl, Vladimir Lysikov +3
Free tensors are tensors which, after a change of bases, have free support: any two distinct elements of its support differ in at least two coordinates. They play a distinguished r…