English

Comments on the Entanglement Spectrum of de Sitter Space

High Energy Physics - Theory 2023-02-08 v1 General Relativity and Quantum Cosmology High Energy Physics - Phenomenology

Abstract

We argue that the Schwarzschild-de Sitter black hole entropy formula does not imply that the entanglement spectrum of the vacuum density matrix of de Sitter space is flat. Specifically, we show that the expectation value of a random projection operator of dimension d1d\gg 1, on a Hilbert space of dimension DdD\gg d and in a density matrix ρ=eK\rho = e^{-K} with strictly positive spectrum, is dD(1+o(1d))\frac{d}{D}\left(1 + o(\frac{1}{\sqrt{d}})\right), independent of the spectrum of the density matrix. In addition, for a suitable class of spectra the asymptotic estimates Tr(ρK)ln Do(1){\rm Tr} (\rho K) \sim {\rm ln}\ D - o(1) and Tr[ρ(KK)2]=aK {\rm Tr} [\rho (K - \langle K\rangle)^2] = a \langle K \rangle are compatible for any order one constant aa. We discuss a simple family of matrix models and projections that can replicate such modular Hamiltonians and the SdS entropy formula.

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Cite

@article{arxiv.2209.08991,
  title  = {Comments on the Entanglement Spectrum of de Sitter Space},
  author = {Tom Banks and Patrick Draper},
  journal= {arXiv preprint arXiv:2209.08991},
  year   = {2023}
}

Comments

10 pages