The global fluctuations in models from random matrix theory, random tilings, and non-colliding particle systems are often governed by log-correlated Gaussian fields. In this talk, I will present an operator-theoretic viewpoint based on Jacobi (and CMV) matrices for a broad class of determinantal point processes associated with orthogonal polynomials. Instead of analyzing correlation functions and their asymptotics, this approach captures fluctuations efficiently through the spectral data of the underlying Jacobi operator. The emergence of log-correlated fields can then be traced back to deep results in analysis, such as the Strong Szegő limit theorem and the Denisov–Rakhmanov theorem. The talk is intended for a broad audience.