Composite graviton self-interactions in a model of emergent gravity

Abstract

We consider a theory of scalars minimally coupled to an auxiliary background metric. The theory is generally covariant and subject to the constraint of vanishing energy-momentum tensor. Eliminating the auxiliary metric leads to a reparametrization invariant, non-polynomial, metric-independent action for the scalar fields. Working in the limit of a large number of physical scalars, a composite massless spin-2 state, the graviton, was identified in previous work, in a two-into-two scalar scattering process. Here, we further explore the possibility that dynamical emergent gravity is a natural feature of generally covariant quantum field theories, by studying the self-interactions of the emergent composite graviton. We show that the fine-tuning previously imposed to ensure the vanishing of the cosmological constant, as well as the existence of the massless spin-2 state, also assures that the emergent graviton's cubic self-interactions are consistent with those of Einstein's general relativity, up to higher-derivative corrections. We also demonstrate in a theory with more than one type of scalar that the composite graviton coupling is universal.

24 pages, 6 figures. v2: minor clarifications

References in corpus (4)

• Emergent Gravity and the Dark Universe
• Inevitable emergence of composite gauge bosons
• Emergent Gravity from Vanishing Energy-Momentum Tensor
• Curved Backgrounds in Emergent Gravity

Cited by in corpus (7)

• Stochastic Emergent Quantum Gravity
• Emergent gravity from hidden sectors and TT deformations
• Analogy between freezing lakes and the cosmic radiation era
• Composite gravity from a metric-independent theory of fermions
• Background-Independent Composite Gravity
• Emergent gravity from off-shell energy fixing
• Composite Gravitons from Metric-Independent Quantum Field Theories