Gravity as Bf Theory plus Potential
نویسندگان
چکیده
Spin foam models of quantum gravity are based on Plebański’s formulation of general relativity as a constrained BF theory. We give an alternative formulation of gravity as BF theory plus a certain potential term for the B-field. When the potential is taken to be infinitely steep one recovers general relativity. For a generic potential the theory still describes gravity in that it propagates just two graviton polarizations. The arising class of theories is of the type amenable to spin foam quantization methods, and, we argue, may allow one to come to terms with renormalization in the spin foam context.
منابع مشابه
A new spinfoam vertex for quantum gravity
We introduce a new spinfoam vertex to be used in models of 4d quantum gravity based on SU(2) and SO(4) BF theory plus constraints. It can be seen as the conventional vertex of SU(2) BF theory, the 15j symbol, in a particular basis constructed using SU(2) coherent states. This basis makes the geometric interpretation of the variables transparent: they are the vectors normal to the triangles with...
متن کامل2-Form Gravity of the Lorentzian Signature
We introduce a new spinorial, BF-like action for the Einstein gravity. This is a first, up to our knowledge, 2-form action which describes the real, Lorentzian gravity and uses only the self-dual connection. In the generic case, the corresponding classical canonical theory is equivalent to the Einstein-Ashtekar theory plus the reality conditions. [email protected] [email protected]
متن کاملAnti de Sitter Gravity from BF-Chern-Simons-Higgs Theories
It is shown that an action inspired from a BF and Chern-Simons model, based on the AdS4 isometry group SO(3, 2), with the inclusion of a Higgs potential term, furnishes the MacDowell-MansouriChamseddine-West action for gravity, with a Gauss-Bonnet and cosmological constant term. The AdS4 space is a natural vacuum of the theory. Using Vasiliev’s procedure to construct higher spin massless fields...
متن کاملar X iv : h ep - t h / 98 07 09 2 v 1 1 3 Ju l 1 99 8 CGPG - 98 / 4 - 5 Spin Foam Models and the Classical Action Principle
We propose a new systematic approach that allows one to derive the spin foam (state sum) model of a theory starting from the corresponding classical action functional. It can be applied to any theory whose action can be written as that of the BF theory plus a functional of the B field. Examples of such theories include BF theories with or without cosmological term, Yang-Mills theories and gravi...
متن کاملGauge symmetries in spin-foam gravity: the case for "cellular quantization".
The spin-foam approach to quantum gravity rests on a quantization of BF theory using 2-complexes and group representations. We explain why, in dimension three and higher, this spin-foam quantization must be amended to be made consistent with the gauge symmetries of discrete BF theory. We discuss a suitable generalization, called "cellular quantization," which (1) is finite, (2) produces a topol...
متن کامل