COLLOQUIUM TALK by Abhay Ashtekar: On the Quantum Nature of the Coulombic Interaction

The Austrian Academy of Sciences, the University of Vienna, the Institute of Science and Technology Austria, the Vienna University of Technology and the Vienna Center for Quantum Science and Technology invite you to a Colloquium Talk by Abhay Ashtekar from the Pennsylvania State University

The interface between Quantum Information and Quantum Field Theory – especially Quantum Gravity – is emerging as a forefront area of fundamental physics. But there is some tension between the way the basic concept of ‘locality’ is commonly understood by the two communities. This tension descends to the issues of interpretation of precisely what would be tested by experiments that have been proposed to probe the quantum nature of gravity. Recall that Hilbert spaces ℋgrav and ℋph of gravitons and photons know only about the ‘radiative modes’ of the gravitational and electromagnetic fields. But matter sources also give rise to ‘Coulombic modes’. Are the ‘Coulombic’ parts of the gravitational and electromagnetic fields produced by quantum matter also quantum mechanical, then? If so, in what sense? The ‘Coulombic modes’ are not even ‘registered’ in the Hilbert spaces ℋgrav and ℋph! Will the proposed experiments directly test the quantum nature of the ‘radiative aspects’ or ‘Coulombic aspects’? The talk will examine such elementary issues by drawing on an exactly soluble, non-perturbative quantum gravity model that is especially well-suited for this purpose.