Towards Gravity from the Quantum

Abstract

We review quantum causal histories starting with their interpretations as a quantum field theory on a causal set and a quantum geometry. We discuss the difficulties that background independent theories based on quantum geometry encounter in deriving general relativity as the low energy limit. We then suggest that general relativity should be viewed as a strictly effective theory coming from a fundamental theory with no geometric degrees of freedom. The basic idea is that an effective theory is characterized by effective coherent degrees of freedom and their interactions. Having formulated the pre-geometric background independent theory as a quantum information theoretic processor, we are able to use the method of noiseless subsystems to extract such coherent (protected) excitations. We follow the consequences, in particular, the implications of effective locality and time.

Expanded version of the contribution to "Towards Quantum Gravity", edited by D.Oriti, to be published by C.U.P

References in corpus (14)

• Analogue Gravity
• Non-perturbative Lorentzian Quantum Gravity, Causality and Topology Change
• Graviton propagator from background-independent quantum gravity
• Spacetime geometry from algebra: spin foam models for non-perturbative quantum gravity
• An invitation to loop quantum gravity
• On Overlapping Divergences
• Dual formulation of spin network evolution
• A theory of quantum gravity based on quantum computation
• Worldsheet formulations of gauge theories and gravity
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• Algebraic Quantum Field Theory: A Status Report
• Background Independent Quantum Field Theory and the Cosmological Constant Problem
• Gauge fixing in Causal Dynamical Triangulations
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Cited by in corpus (12)

• Analogue Gravity
• Disordered locality in loop quantum gravity states
• The Plebanski action extended to a unification of gravity and Yang-Mills theory
• Statistical Mechanics of Graphity Models
• Propagation and interaction of chiral states in quantum gravity
• Particle Identifications from Symmetries of Braided Ribbon Network Invariants
• Generic predictions of quantum theories of gravity
• Spectroscopy of a canonically quantized horizon
• Conserved Quantities in Background Independent Theories
• No Ward-Takahashi identity violation for an Abelian tensorial group field theories with closure constraint
• New views on the low-energy side of gravity
• Quantum reference frames and triality