Undecidability of the spectral gap

TS Cubitt, D Perez-Garcia, MM Wolf - Nature, 2015 - nature.com
The spectral gap—the energy difference between the ground state and first excited state of a
system—is central to quantum many-body physics. Many challenging open problems, such …

Undecidability in quantum thermalization

N Shiraishi, K Matsumoto - Nature communications, 2021 - nature.com
The investigation of thermalization in isolated quantum many-body systems has a long
history, dating back to the time of developing statistical mechanics. Most quantum many …

The undecidability of conditional affine information inequalities and conditional independence implication with a binary constraint

CT Li - IEEE Transactions on Information Theory, 2022 - ieeexplore.ieee.org
We establish the undecidability of conditional affine information inequalities, the
undecidability of the conditional independence implication problem with a constraint that …

Undecidable problems in quantum field theory

Y Tachikawa - International Journal of Theoretical Physics, 2023 - Springer
We point out that some questions in quantum field theory are undecidable in a precise
mathematical sense. More concretely, it will be demonstrated that there is no algorithm …

The busy beaver frontier

S Aaronson - ACM SIGACT News, 2020 - dl.acm.org
The Busy Beaver function, with its incomprehensibly rapid growth, has captivated
generations of computer scientists, mathematicians, and hobbyists. In this survey, I o er a …

Undecidability of the spectral gap

T Cubitt, D Perez-Garcia, MM Wolf - Forum of Mathematics, Pi, 2022 - cambridge.org
We construct families of translationally invariant, nearest-neighbour Hamiltonians on a 2D
square lattice of d-level quantum systems (d constant), for which determining whether the …

On some algebraic ways to calculate zeros of the Riemann zeta function

Y Matiyasevich - International Conference on Algebraic Informatics, 2022 - Springer
The Riemann zeta function is an important number-theoretical tool for studying prime
numbers. The first part of the paper is a short survey of some known results about this …

Undecidability of the Spectral Gap (full version)

T Cubitt, D Perez-Garcia, MM Wolf - arXiv preprint arXiv:1502.04573, 2015 - arxiv.org
We show that the spectral gap problem is undecidable. Specifically, we construct families of
translationally-invariant, nearest-neighbour Hamiltonians on a 2D square lattice of d-level …

A Pair of Bayesian Network Structures has Undecidable Conditional Independencies

CT Li - arXiv preprint arXiv:2405.07107, 2024 - arxiv.org
Given a Bayesian network structure (directed acyclic graph), the celebrated d-separation
algorithm efficiently determines whether the network structure implies a given conditional …

The busy beaver competition: a historical survey

P Michel - arXiv preprint arXiv:0906.3749, 2009 - arxiv.org
Tibor Rado defined the Busy Beaver Competition in 1962. He used Turing machines to give
explicit definitions for some functions that are not computable and grow faster than any …