Roel Andringa

Position: 
PhD student
Group: 
Quantum Gravity
Telephone number: 
+31 (0)50 363 7430
Room number: 
5111.0107
Email: 
r [dot] andringa [at] rug [dot] nl

I started out as a PhD student in 2008, with gravity in (2+1) dimensions as topic. Starting from a simple Hilbert action, gravity in (2+1) dimensions appears to be not that exciting; there aren't any degrees of freedom to give rise to gravitons. Adding topological terms or looking at supergravity extensions in (2+1) dimensions already adds quite some interesting features. In our first article (http://arxiv.org/abs/0907.4658) we investigated a particular supergravity theory in (2+1) dimensions. After that I switched to non-relativistic theories of gravity. We started out investigating non-relativistic conformal gravity theories, which brought us back to the core: Newtonian gravity. In our second article, (http://arxiv.org/abs/1011.1145) we found that Newtonian Gravity, in the guise of the so-called theory of Newton-Cartan, can be seen as a gauge theory of the Bargmann algebra (which is the centrally extended Galileï algebra) if we apply the gauging procedure which people also use to obtain Einstein gravity from the Poincaré algebra. Several constraints in the Newton-Cartan theory can be explained via this gauging as curvature constraints. Also, the need for the central extension in the Bargmann algebra becomes clear in this gauging. Now we are extending this procedure to so-called Newton-Hooke algebras, which are used for the description of non-relativistic branes in string theory. The procedure also gives a rather natural extension to non-relativistic supergravities. It would be nice to obtain super-Newton!