6533b827fe1ef96bd1285b78
RESEARCH PRODUCT
Generalized Ashtekar variables for Palatini f(R) models
Giovanni MontaniGiovanni MontaniSimon BoudetSimon BoudetFlavio Bombacignosubject
PhysicsHigh Energy Physics - TheoryNuclear and High Energy Physics010308 nuclear & particles physicsImmirzi parameterGaussScalar (mathematics)FOS: Physical sciencesLoop quantum gravityGeneral Relativity and Quantum Cosmology (gr-qc)Affine connection01 natural sciencesGeneral Relativity and Quantum CosmologyAshtekar variablessymbols.namesakeGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theory (hep-th)0103 physical sciencessymbolslcsh:QC770-798lcsh:Nuclear and particle physics. Atomic energy. RadioactivityEinstein010306 general physicsScalar fieldMathematical physicsdescription
We consider special classes of Palatini f(R) theories, featured by additional Loop Quantum Gravity inspired terms, with the aim of identifying a set of modified Ashtekar canonical variables, which still preserve the SU(2) gauge structure of the standard theory. In particular, we allow for affine connection to be endowed with torsion, which turns out to depend on the additional scalar degree affecting Palatini f(R) gravity, and in this respect we successfully construct a novel Gauss constraint. We analyze the role of the additional scalar field, outlining as it acquires a dynamical character by virtue of a non vanishing Immirzi parameter, and we describe some possible effects on the area operator stemming from such a revised theoretical framework. Finally, we compare our results with earlier studies in literature, discussing differences between metric and Palatini approaches. It is worth noting how the Hamiltonian turns out to be different in the two cases. The results can be reconciled when the analysis is performed in the Einstein frame.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2021-02-01 |