The Density Matrix of a Causal Diamond

Thomas Banks (Rutgers)

23-Mar-2023, 18:30-19:30 (12 months ago)

Abstract: I will review and reinterpret a number of papers from the 1990s, which indicate that the operator algebra of a causal diamond in models of quantum gravity is finite dimensional and that the modular Hamiltonian of the "empty diamond" state has an expectation value and fluctuations determined by geometrical properties of the diamond. These universal formulae depend on a view of Einstein's equations as the hydrodynamic equations of the area law for diamond entropy, which means that they are valid beyond any "semi-classical" approximation. A model of quantum gravity consists of finding a quantum system whose hydrodynamics is consistent with a given solution of Einstein's equations. I will quickly review many papers and attendees are encouraged to read them before the talk. (List will follow). Among the many implications of these papers is that quantum field theory cannot account for most of the entropy in a causal diamond, and that the cosmological constant should not be thought of as an energy density.

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HEP - phenomenologyHEP - theorymathematical physics

Audience: researchers in the topic


NHETC Seminar

Series comments: Description: Weekly research seminar of the NHETC at Rutgers University

Livestream link is available on the webpage.

Organizers: Christina Pettola*, Sung Hak Lim, Vivek Saxena*, Erica DiPaola*
*contact for this listing

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