PIRSA:17040009

Video URL

https://pirsa.org/17040009

Testing microscopic discretization

(2017). Testing microscopic discretization. Perimeter Institute for Theoretical Physics. https://pirsa.org/17040009

Testing microscopic discretization. Perimeter Institute for Theoretical Physics, Apr. 18, 2017, https://pirsa.org/17040009 

          @misc{ scivideos_PIRSA:17040009,
            doi = {10.48660/17040009},
            url = {https://pirsa.org/17040009},
            author = {},
            keywords = {Quantum Foundations},
            language = {en},
            title = {Testing microscopic discretization},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2017},
            month = {apr},
            note = {PIRSA:17040009 see, \url{https://scivideos.org/pirsa/17040009}}
          }
Talk numberPIRSA:17040009
DOI10.48660/17040009
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

What can we say about the spectra of a collection of microscopic variables when only their coarse-grained sums are experimentally accessible? In this paper, using the tools and methodology from the study of quantum nonlocality, we develop a mathematical theory of the macroscopic fluctuations generated by ensembles of independent microscopic discrete systems. We provide algorithms to decide which multivariate gaussian distributions can be approximated by sums of finitely-valued random vectors. We study non-trivial cases where the microscopic variables have an unbounded range, as well as asymptotic scenarios with infinitely many macroscopic variables. From a foundational point of view, our results imply that bipartite gaussian states of light cannot be understood as beams of independent d-dimensional particle pairs. It is also shown that the classical description of certain macroscopic optical experiments, as opposed to the quantum one, requires variables with infinite cardinality spectra.