Instanton representation of Plebanski gravity. Application to gravitons about DeSitter spacetime

Quantum Gravity in Plebanski Formulation

We present a theory of four-dimensional quantum gravity with massive gravitons which may be essentially renormalizable. In the Plebanski formulation of General Relativity (GR), in which the tetrads, the connection and the curvature are all independent variables (and the usual relations among these quantities are valid only on-shell), we consider a nonperturbative theory of gravity with a nonzero background connection. We predict a tiny value of the graviton mass: m_g\approx 1.8\times 10^{-42} GeV and an extremely small dimensionless coupling constant of the perturbative gravitational interacti…

Bi-metric theory of gravity from the non-chiral Plebanski action

We study a modification of the Plebanski action for general relativity, which leads to a modified theory of gravity with eight degrees of freedom. We show how the action can be recasted as a bi-metric theory of gravity, and expanding around a bi-flat background we identify the six extra degrees of freedom with a second, massive graviton and a scalar mode.

Soft Gravitons and the Flat Space Limit of Anti-deSitter Space

We argue that flat space amplitudes for the process $ 2 \to n$ gravitons at center of mass energies $\sqrt{s}$ much less than the Planck scale, will coincide approximately with amplitudes calculated from correlators of a boundary CFT for AdS space of radius $R\gg L_P$, only when $n < R/L_P$ . For larger values of $n$ in AdS space, insisting that all the incoming energy enters "the arena" [arXiv:hep-th/9901079], implies the production of black holes, whereas there is no black hole production in the flat space amplitudes. We also argue, from unitarity, that flat space amplitudes for all $n$ are …

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-perturbative level, we find a situation similar to genuine bi-gravities: even choosing the Pauli-Fierz mass term, the ghost mode propagates through the interactions. We present some simple potentials leading to two and three deg…

The linearization of the Kodama state

We study the question of whether the linearization of the Kodama state around classical deSitter spacetime is normalizable in the inner product of the theory of linearized gravitons on deSitter spacetime. We find the answer is no in the Lorentzian theory. However, in the Euclidean theory the corresponding linearized Kodama state is delta-functional normalizable. We discuss whether this result invalidates the conjecture that the full Kodama state is a good physical state for quantum gravity with positive cosmological constant.

类普列班斯基的面积度规引力：联络、曲率与动力学

Area metric gravity à la Plebanski: connection, curvature and dynamics

本文从修正普列班斯基作用量构建非线性面积度规动力学，导出面积度规作用量并将其重述为庞加莱规范理论，确定的有效长度度规作用量可描述含宇称破缺耦合的引力子与质量自旋2场，为宇宙学应用提供基础。