Unitary forms of Kac-Moody algebras and Kac-Moody groups
Lead Research Organisation:
Justus-Liebig University Giessen
Department Name: Institute of Mathematics
Abstract
Existing cosmological theories suggest that, close to a cosmological singularity like a big-bang or a big-crunch, the description of the universe in terms of spatial continuum and space-time based quantum field theory breaks down and the information encoded in the spatial variation of the geometryof the universe gets transferred into spatially independent but time-dependent Lie-algebraic variables encoded in the infinite-dimensional symmetric space of a real split Kac-Moody algebra over its unitary form. In this context the understanding of representations of the unitary form of the real split Kac-Moody algebra of so-called type E10 is of particular interest. One such representation can be constructed as an extension to the whole unitary form of the 32-dimensional spin representation of its regular subalgebra of type A9, using a presentation by generators and relations of unitary forms given by Berman.This project is set in pure mathematics within the areas of infinite-dimensional Lie theory and geometric group theory. It will combine classical techniques from the theory of Kac-Moody algebras and Kac-Moody groups in characteristic 0 and their unitary forms with the quickly developing theory of unitary forms of Kac-Moody groups over arbitrary fields based on the theory of twin buildings. Its goal is to contribute to a uniform structure theory of unitary forms of Kac-Moody algebras and of Kac-Moody groups of indefinite type. The main emphasis of this project will be on finite-dimensional representations and on ideals and normal subgroups, respectively, of these unitary forms, starting with the above-mentioned finite-dimensional representation discovered in cosmology.
Planned Impact
As described in the case for support, I expect an academic impact of the proposed project in infinite-dimensional Lie theory, in geometric group theory and in cosmology/high energy physics. This project is a blue-sky research project in fundamental science, and I do not expect any immediate economic impact from this project.
Publications

Ghatei D
(2017)
Spin covers of maximal compact subgroups of Kac-Moody groups and spin-extended Weyl groups
in Journal of Group Theory

Hainke, G.
(2015)
Generalized spin representations. With an appendix by Max Horn and Ralf K ¨ohl.
in M ¨unster J. of Math.

Lautenbacher Robin
(2018)
Extending Generalized Spin Representations
in JOURNAL OF LIE THEORY
Related Projects
Project Reference | Relationship | Related To | Start | End | Award Value |
---|---|---|---|---|---|
EP/H02283X/1 | 31/08/2010 | 01/01/2011 | £312,191 | ||
EP/H02283X/2 | Transfer | EP/H02283X/1 | 29/06/2011 | 28/04/2014 | £118,271 |
Description | We understood the 1/2-spin representation constructed by string theorists, re-constructed the 3/2- and 5/2-spin representations, gave Weyl-group based explicit formulae, and found a Weyl-group based formula for the 7/2-spin representation. |
Exploitation Route | There currently is cooperation between Nicolai and Kleinschmidt from string theory and Lautenbacher and myself towards further new representations. |
Sectors | Other |
Description | Responsive mode research grant |
Amount | € 280,000 (EUR) |
Funding ID | KO4323/13 |
Organisation | German Research Foundation |
Sector | Charity/Non Profit |
Country | Germany |
Start | 09/2016 |
End | 07/2021 |