Gravity from a Particle Physicists' perspective
Oct, 200927 pages
Published in:
- PoS ISFTG (2009) 011
Contribution to:
e-Print:
- 0910.5167 [hep-th]
DOI:
Report number:
- PI-PARTPHYS-156
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Citations per year
Abstract: (arXiv)
In these lectures I review the status of gravity from the point of view of the gauge principle and renormalization, the main tools in the toolbox of theoretical particle physics. In the first lecture I start from the old question "in what sense is gravity a gauge theory?" I will reformulate the theory of gravity in a general kinematical setting which highlights the presence of two Goldstone boson-like fields, and the occurrence of a gravitational Higgs phenomenon. The fact that in General Relativity the connection is a derived quantity appears to be a low energy consequence of this Higgs phenomenon. From here it is simple to see how to embed the group of local frame transformations and a Yang Mills group into a larger unifying group, and how the distinction between these groups, and the corresponding interactions, derives from the VEV of an order parameter. I will describe in some detail the fermionic sector of a realistic "GraviGUT" with SO(3,1)xSO(10) \subset SO(3,11). In the second lecture I will discuss the possibility that the renormalization group flow of gravity has a fixed point with a finite number of attractive directions. This would make the theory well behaved in the ultraviolet, and predictive, in spite of being perturbatively nonrenormalizable. There is by now a significant amount of evidence that this may be the case. There are thus reasons to believe that quantum field theory may eventually prove sufficient to explain the mysteries of gravity.Note:
- Lectures given at the Fifth International School on Field Theory and Gravitation, Cuiaba, Brazil April 20-24 2009. To appear in PoS
- lectures: Cuiaba 2009/04/20
- general relativity
- Higgs model
- Klein-Gordon equation
- differential forms
- differential geometry
- grand unified theory
- SO(3,1)
- SO(3,11)
- SO(10)
References(75)
Figures(3)