Binding quantum matter and space-time, without romanticism

Abstract

Understanding the emergence of a tangible 4-dimensional space-time from a quantum theory of gravity promises to be a tremendously difficult task. This article makes the case that this task may not have to be carried. Space-time as we know it may be fundamental to begin with. I recall the common arguments against this possibility and review a class of recently discovered models bypassing the most serious objection. The generic solution of the measurement problem that is tied to semiclassical gravity as well as the difficulty of the alternative make it a reasonable default option in the absence of decisive experimental evidence.

arXiv comment13 pages, 4 figures, branched out from an essay for the Beyond spacetime contest, comments welcome

References in corpus (24)

• Models of Wave-function Collapse, Underlying Theories, and Experimental Tests
• A Straightforward Introduction to Continuous Quantum Measurement
• Quantum Gravity: a Progress Report
• Gravitation and quantummechanical localization of macroobjects
• Quantum Test of the Universality of Free Fall
• Dark energy as the weight of violating energy conservation
• The Schrödinger-Newton equation and its foundations
• A classical channel model for gravitational decoherence
• Sourcing semiclassical gravity from spontaneously localized quantum matter
• Predictions and Primitive Ontology in Quantum Foundations: A Study of Examples
• Coupling Classical and Quantum Variables using Continuous Quantum Measurement Theory
• Renormalization flow of QED
• Bounds on quantum communication via Newtonian gravity
• Principle of least decoherence for Newtonian semi-classical gravity
• No-faster-than-light-signaling implies linear evolutions. A re-derivation
• Relativistic collapse dynamics and black hole information loss
• Wheeler-DeWitt quantization and singularities
• Generally covariant dynamical reduction models and the Hadamard condition
• Ghirardi-Rimini-Weber model with massive flashes
• Detecting gravitational decoherence with clocks: Limits on temporal resolution from a classical channel model of gravity
• Loop quantum cosmology and singularities
• Newtonian Semiclassical Gravity in the Ghirardi-Rimini-Weber Theory with Matter Density Ontology
• Towards a novel approach to semi-classical gravity
• Interacting quantum field theories as relativistic statistical field theories of local beables

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• Semiclassical cosmology with back reaction: the Friedmann-Schrodinger equation and inflation
• Tabletop Experiments for Quantum Gravity Are Also Tests of the Interpretation of Quantum Mechanics
• Mixture equivalence principles and post-quantum theories of gravity
• Testing de Broglie's double solution in the mesoscopic regime
• Against the disappearance of spacetime in quantum gravity
• Comments on graviton detection
• The thermodynamics of readout devices and semiclassical gravity