The Bath Framework for Emergent Gravity
A Consolidated Statement of the TT-Measurement Corpus
"Matter is continuously and weakly monitored by an unobserved quantum environment through the transverse-traceless sector of its stress-energy. Gravity emerges as the unique feedback interaction required to make this monitoring dynamically consistent."
Spacetime geometry is not fundamental; it is an effective classical description of the resulting measurement-feedback fixed point.
Gravity is not fundamental — it is required
What is assumed to exist — and nothing more.
A very large-N quantum system (effectively a quantum field theory). Lorentz invariant. In its vacuum ground state. Not directly observable — traced out.
All observable degrees of freedom. Universally characterized by a stress-energy tensor Tμν.
The only universal interaction postulated:
TTTij is the transverse-traceless projection of stress-energy:
The Bath monitors shape, not position or total energy
Decoherence is operationally equivalent to continuous weak measurement.
Any reduced dynamics of the form:
is operationally equivalent to continuous weak measurement of TTT.
The universe can only "see" quadrupole and higher
Continuous measurement generically produces:
If uncompensated, TT measurement would cause runaway heating.
Empirically, this does not occur → feedback required
The only interaction that makes continuous TT monitoring consistent.
Any continuous measurement can be represented as measurement + feedback Hamiltonian.
| Constraint | Physical Meaning |
|---|---|
| Locality | No action at a distance |
| No-Signaling | No superluminal communication |
| Universality | Couples to all stress-energy |
| Conservation | Statistical energy balance |
Under these constraints, there is exactly one solution:
This IS gravity.
Where N is Bath degrees of freedom and λ is the microscopic coupling.
Integrating out the Bath yields an influence functional with:
Even though only TT modes are monitored, via correlation screening.
In the classical limit:
Geodesics = least-disturbance trajectories.
Geometry is derived, not postulated
The metric is classical, not quantum
No additional degrees of freedom
A classical, coarse-grained description of the fixed point of TT measurement and gravitational feedback.
This is a self-consistency condition: balance between information extraction and back-action.
What the framework predicts — and how it differs from alternatives.
Shape-dependent, not mass-dependent alone. Spheres decohere differently than dumbbells of the same mass.
Shared Bath modes induce correlations between nearby masses. Force fluctuations are not independent.
The same mechanism produces both decoherence and gravitational attraction. They cannot be separated.
| Alternative Model | Key Difference |
|---|---|
| Penrose/Diósi Collapse | Mass-dependent only; no shape dependence |
| Graviton Emission | No correlated noise; independent fluctuations |
| Thermal Decoherence | Wrong frequency dependence; no TT structure |
| Standard GR | No decoherence prediction; geometry fundamental |
It is traced out by construction. We see only its effects on matter.
Spacetime is an effective description, not ontologically basic.
It is the feedback required to make decoherence consistent.
This is a consistent effective framework, not a final theory.
"Reality is not geometry first.
Reality is stable quantum matter under continuous partial observation.
Spacetime and gravity are how that stability appears from within."
Internally consistent
Experimentally falsifiable
Incomplete in a precisely known way
This is the correct posture of a serious physical framework.
But wait — does TT-only coupling actually reproduce General Relativity?