English

Can Quantum de Sitter Space Have Finite Entropy?

High Energy Physics - Theory 2008-11-26 v4 General Relativity and Quantum Cosmology

Abstract

If one tries to view de Sitter as a true (as opposed to a meta-stable) vacuum, there is a tension between the finiteness of its entropy and the infinite-dimensionality of its Hilbert space. We invetsigate the viability of one proposal to reconcile this tension using qq-deformation. After defining a differential geometry on the quantum de Sitter space, we try to constrain the value of the deformation parameter by imposing the condition that in the undeformed limit, we want the real form of the (inherently complex) quantum group to reduce to the usual SO(4,1) of de Sitter. We find that this forces qq to be a real number. Since it is known that quantum groups have finite-dimensional representations only for q=q= root of unity, this suggests that standard qq-deformations cannot give rise to finite dimensional Hilbert spaces, ruling out finite entropy for q-deformed de Sitter.

Keywords

Cite

@article{arxiv.hep-th/0602002,
  title  = {Can Quantum de Sitter Space Have Finite Entropy?},
  author = {Chethan Krishnan and Edoardo Di Napoli},
  journal= {arXiv preprint arXiv:hep-th/0602002},
  year   = {2008}
}

Comments

10 pages, v2: references added, v3: minor corrections, abstract and title made more in-line with the result, v4: published version

R2 v1 2026-07-22T15:34:34.387Z