What the study found
The paper develops a proposed theory in which wavefunction collapse in general relativity gives rise to time. In this framework, quantum states that violate the momentum and Hamiltonian constraints represent instances of time, and stochastic fluctuations of the lapse and shift drive evolution toward a diffeomorphism-invariant state.
Why the authors say this matters
The authors conclude that this approach provides a way to explain time evolution, an arrow of time, and emergent physical excitations within general relativity. The study suggests that the scalar mode may be a viable candidate for dark matter because of its long-wavelength survival and long-range effects.
What the researchers tested
The researchers further developed a recently proposed theory of time based on wavefunction collapse in general relativity. They demonstrated the framework using a cosmological constant-dominated universe and relied on semi-classical and adiabatic approximations, with results controlled in the limit of large space dimension.
What worked and what didn't
Under wavefunction collapse, the scale factor monotonically increases and can act as a clock. The scalar, vector, and tensor gravitons arise as physical excitations; the tensor gravitons show emergent unitary dynamics in the long-time limit, while the extra modes are strongly damped by non-unitary dynamics that suppress constraint-violating excitations. The vector mode is uniformly suppressed at all length scales, and the scalar mode decays at a rate proportional to its wave vector.
What to keep in mind
The abstract describes the framework as a proposed theory and does not present it as established fact. The demonstrations are limited to a cosmological constant-dominated universe and to semi-classical and adiabatic approximations, and the available summary does not state additional limitations.
Key points
- The paper proposes that wavefunction collapse in general relativity can generate time evolution.
- Quantum states that violate the momentum and Hamiltonian constraints are treated as instances of time in the theory.
- The scale factor is described as increasing monotonically under collapse, so it can act as a clock.
- Tensor gravitons are said to show emergent unitary dynamics in the long-time limit.
- The scalar mode is described as a possible dark matter candidate because long-wavelength excitations survive longer.
Disclosure
- Research title:
- Wavefunction collapse is proposed as a source of time and emergent gravity modes
- Authors:
- Sung-Sik Lee
- Institutions:
- Perimeter Institute, McMaster University
- Publication date:
- 2026-04-22
- OpenAlex record:
- View
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