Ivan Agullo
Louisiana State UniversityEntanglement in quantum field theory

Poster for Ivan Agullo's Virtual Seminar Talk title "Entanglement in Quantum Field Theory", 4pm CEST

It is well known that, even the simplest states within the simplest field theories, are highly entangled. The main support for this fact comes from calculations of entanglement entropy between a region of space and its complement. I find two uncomfortable facts in the calculation of such entropy: (i) The result is actually infinite, and a regulator is needed to extract a finite quantity out of it; and more important, (ii) it involves infinite regions of space and infinitely many degrees of freedom of the field. During the last months, I have been thinking of a more tangible way of quantifying entanglement in quantum field theories, involving only a finite number of degrees of freedom, finite regions of space and quantities that are directly measurable.
In this talk, I will summarize the understanding I have achieved so far, both for Minkowski and de Sitter spacetimes. This is work in progress, and I will especially emphasize what I do not understand yet, aiming to receive feedback and provoke discussions.