Conformal structures in cosmology

Field: general relativity

Conformal techniques are very useful in gravitational physics to simplify the description of certain spacetime properties. For example, they can be used to 'pull in' infinitely distant regions to finite places or vice versa.

We investigated conformal classifications of cosmological models and developed a conformal framework for anisotropic cosmological futures which are compatible with Penrose’s Weyl Curvature Hypothesis. This framework effectively ‘conformally regularizes’ the physical spacetime by relating it to an unphysical spacetime via a conformal factor which absorbs most of the singular behavior.

Further reading:

• P. A. Höhn and S. M. Scott 2009, "Encoding cosmological futures with conformal structures", Class. Quant. Grav. 26 035019, https://doi.org/10.1088/0264-9381/26/3/035019 (Highlight of 2008/09, Preprint arXiv:1001.2928)
• P. A. Höhn and S. M. Scott 2008, "Quiescent cosmology and the final state of the universe," Int. J. Mod. Phys. D 17 571, https://doi.org/10.1142/S0218271808012280 (receiving Honourable Mention in the Gravity Research Foundation Essay Awards 2007, Preprint arXiv:1001.2823)
• P. A. Höhn and S. M. Scott 2010, "Conformal formulation of cosmological futures", Proceedings of
  the 12th Marcel Grossmann Meeting (Paris, July 2009), pp. 1802, https://doi.org/10.1142/9789814374552_0328 (Preprint arXiv:1001.4029)