Symmetries in Entangled States
Symmetries in Entangled States under Bohm’s Quantum Potential (FTL Assumption)
Assuming faster-than-light (FTL) communication is possible via Bohm’s Quantum Potential, you’re entering a
non-local hidden variable interpretation of quantum mechanics. In that framework—Bohmian Mechanics—the
quantum potential acts instantaneously across spatial distances, coordinating entangled particles.
In such a universe, if FTL influence via the quantum potential exists, Lorentz invariance is broken or modified,
and a preferred foliation of spacetime (absolute simultaneity) must be assumed. Given that, we can explore what
symmetries might still be applicable to entangled states:
1. Permutation Symmetry of Entangled States
- Entangled states of identical particles are symmetric (bosons) or antisymmetric (fermions) under exchange.
- This symmetry is preserved even across large spatial separations.
Example:
|Ψ⟩ = (1/√2)(|↑⟩ₐ |↓⟩ᵦ − |↓⟩ₐ |↑⟩ᵦ)
2. Gauge Symmetry
- The global phase invariance of quantum states (a
U(1)symmetry) still holds. - The Bohmian wavefunction evolves under Schrödinger dynamics and remains gauge invariant.
3. Non-Relativistic Galilean Symmetry
- Bohmian mechanics typically violates Lorentz symmetry, but preserves Galilean invariance in the non-relativistic limit.
- The quantum potential is invariant under Galilean transformations.
4. Time-Reversal Symmetry
- Bohmian trajectories are deterministic and time-reversible.
- The Schrödinger equation is time-reversal symmetric (modulo complex conjugation), and so is Bohmian evolution.
5. Configuration Space Symmetry
- In Bohmian mechanics, the wave function lives in configuration space, not 3D physical space.
- Entangled states are non-factorizable and inherently nonlocal in this space.
Caveat: Breaking Lorentz Symmetry
- Allowing FTL interaction via the quantum potential violates Lorentz symmetry, unless a preferred reference frame is introduced.
- Spatial rotation symmetry (SO(3)) may be preserved, but boost symmetry is broken.
Summary Table
| Symmetry | Preserved? | Notes |
|---|---|---|
| Permutation (Exchange) | ✅ | Important for identical entangled particles |
| Gauge (U(1)) | ✅ | Global phase invariance |
| Galilean | ✅ | Non-relativistic limit; Bohmian-compatible |
| Lorentz | ❌ | Violated by non-local influences |
| Time-Reversal | ✅ | Bohmian mechanics is deterministic and reversible |
| Configuration Space Symmetry | ✅ | Fundamental in Bohmian interpretation |
In Conclusion
If FTL communication via Bohm’s quantum potential exists, the entangled states still obey permutation, gauge, time-reversal, and
configuration-space symmetries, but Lorentz invariance must be relinquished. In its place, a hidden preferred frame
or foliation of spacetime is assumed. The overall coherence of entangled states is preserved through the nonlocal structure of the
wavefunction in configuration space, guided by a universal quantum potential.