English

On extremal surfaces and de Sitter entropy

High Energy Physics - Theory 2018-07-10 v4

Abstract

We study extremal surfaces in the static patch coordinatization of de Sitter space, focussing on the future and past universes. We find connected timelike codim-2 surfaces on a boundary Euclidean time slice stretching from the future boundary I+I^+ to the past boundary II^-. In a limit, these surfaces pass through the bifurcation region and have minimal area with a divergent piece alone, whose coefficient is de Sitter entropy in 4-dimensions. These are reminiscent of rotated versions of certain surfaces in the AdSAdS black hole. We close with some speculations on a possible dS/CFTdS/CFT interpretation of 4-dim de Sitter space as dual to two copies of ghost-CFTs in an entangled state. For a simple toy model of two copies of ghost-spin chains, we argue that similar entangled states always have positive norm and positive entanglement.

Keywords

Cite

@article{arxiv.1711.01107,
  title  = {On extremal surfaces and de Sitter entropy},
  author = {K. Narayan},
  journal= {arXiv preprint arXiv:1711.01107},
  year   = {2018}
}

Comments

Latex, 20pgs, 3 figs, v3: clarifications added, some reorganizing of text, review of ghost-spin chains added, matches version to be published, v4: further minor clarifications added

R2 v1 2026-06-22T22:35:09.785Z