Quantum Entanglement and the Holographic Principle
Details

Call:
IDPASC Portugal  PHD Programme 2016

Academic Year:
2016 / 2017

Domains:
Theoretical Particle Physics  Cosmology

Supervisor:
Alex Blin

CoSupervisor:
Marcos RodriguesSampaio

Institution:
Universidade de Coimbra

Host Institution:
Universidade de Coimbra

Abstract:
The tentative to explain the origin of dark energy as fluctuations of the QFT vacuum up to the Planckscale fails by more than 120 orders of magnitude, which is the wellknown cosmological constant problem. The holographic principle ['t Hooft, Susskind], according to which the information content of a black hole is only proportional to its surface and not to the volume, together with the consideration that a region of space cannot contain more information than a black hole, indicate that the usual QFT vacuum approach is hugely overcounting states. A possible mechanism to reduce the degrees of freedom, and thus the overcounting, is provided by quantum entanglement. The behavior of entanglement is influenced by the curvature of space and by the presence of a horizon. In a recent study [Pavão] entanglement was calculated in a de Sitter universe. Although the entanglement criteria used there [Simon] are not yet quantitative for the system studied and applicable only to bipartite systems, they do show the existence of entanglement. The proposed work would encompass the following.  Formulating the problem in a way to be able to calculate a quantitative measure of entanglement (using e.g. gaussian states and the appropriate entanglement criteria).  Evaluating the influence of entanglement on the overcounting problem.  Going beyond bipartite systems.  Generalizing from the de Sitter universe to the more complex situation of the present epoch. The student would be cosupervised by M. Sampaio from UFMG, Brazil (see [Alexander] for a closely related study). References: ['t Hooft] G. 't Hooft, arXiv:grqc/9310026 [Susskind] L.Susskind, arXiv:hepth/9409089 [Pavão] R.Pavão, MS Thesis U. Coimbra 2016 [Simon] R Simon, arXiv:quantph/9909044 [Alexander] H.Alexander, G.de Souza, I.G.da Paz, M. Sampaio, arXiv:1602.03487