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6 papers found.
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Sachs’ free data in real connection variables

We discuss the Hamiltonian dynamics of general relativity with real connection variables on a null foliation, and use the Newman-Penrose formalism to shed light on the geometric meaning of the various constraints. We identify the equivalent of Sachs’ constraint-free initial data as projections of connection components related to null rotations, i.e. the translational part of the...

Erratum to: Non-singular rotating black hole with a time delay in the center

Gen Relativ Gravit Simone Speziale 0 Tommaso De Lorenzo 0 Andrea Giusti 0 0 Centre de Physique Theorique, CNRS-UMR 7332, Aix-Marseille Université & Université de Toulon , Case 907, Campus de

Loop quantum gravity, twistors, and some perspectives on the problem of time

I give a brief introduction to the relation between loop quantum gravity and twistor theory, and comment on some perspectives on the problem of time.

Chiral description of massive gravity

Abstract We propose and study a new first order version of the ghost-free massive gravity. Instead of metrics or tetrads, it uses a connection together with Plebanski’s chiral 2-forms as fundamental variables, rendering the phase space structure similar to that of SU(2) gauge theories. The chiral description simplifies computations of the constraint algebra, and allows us to...

Perturbative quantum gravity with the Immirzi parameter

We study perturbative quantum gravity in the first-order tetrad formalism. The lowest order action corresponds to Einstein-Cartan plus a parity-odd term, and is known in the literature as the Holst action. The coupling constant of the parity-odd term can be identified with the Immirzi parameter γ of loop quantum gravity. We compute the quantum effective action in the one-loop...

Pauli-Fierz mass term in modified Plebanski gravity

We study SO(4) BF theory plus a general quadratic potential, which describes a bi-metric theory of gravity. We identify the profile of the potential leading to a Pauli-Fierz mass term for the massive graviton, thereby avoiding the linearized ghost. We include the Immirzi parameter in our analysis, and find that the mass of the second graviton depends on it. At the non...