Classifying Causal Structures: Ascertaining when Classical Correlations are Constrained by Inequalities

التفاصيل البيبلوغرافية
العنوان: Classifying Causal Structures: Ascertaining when Classical Correlations are Constrained by Inequalities
المؤلفون: Khanna, Shashaank, Ansanelli, Marina Maciel, Pusey, Matthew F., Wolfe, Elie
المصدر: Phys. Rev. Research 6, 023038 (2024)
سنة النشر: 2023
المجموعة: Mathematics
Quantum Physics
Statistics
مصطلحات موضوعية: Quantum Physics, Mathematics - Statistics Theory, Statistics - Machine Learning
الوصف: The classical causal relations between a set of variables, some observed and some latent, can induce both equality constraints (typically conditional independences) as well as inequality constraints (Instrumental and Bell inequalities being prototypical examples) on their compatible distribution over the observed variables. Enumerating a causal structure's implied inequality constraints is generally far more difficult than enumerating its equalities. Furthermore, only inequality constraints ever admit violation by quantum correlations. For both those reasons, it is important to classify causal scenarios into those which impose inequality constraints versus those which do not. Here we develop methods for detecting such scenarios by appealing to d-separation, e-separation, and incompatible supports. Many (perhaps all?) scenarios with exclusively equality constraints can be detected via a condition articulated by Henson, Lal and Pusey (HLP). Considering all scenarios with up to 4 observed variables, which number in the thousands, we are able to resolve all but three causal scenarios, providing evidence that the HLP condition is, in fact, exhaustive.
Comment: 37+12 pages, 13 figures, 4 tables
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevResearch.6.023038
URL الوصول: http://arxiv.org/abs/2308.02380
رقم الأكسشن: edsarx.2308.02380
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevResearch.6.023038