← All parts of this equation

Equation 7 · Part 5 · How Much of Gravitationally Induced Entanglement Is in the Eye of the Frame

A on R, B on L

φent=φLL+φRR−φLR−φRL\varphi_{\text{ent}} = \varphi_{LL} + \varphi_{RR} - \varphi_{LR} - \varphi_{RL}
φRL\varphi_{RL}

What this part means

The phase of the other crossed branch pair. It is also subtracted in the local-phase-invariant combination.

Its job in the formula

This crossed-path phase is also subtracted, completing cancellation of A-R and B-L local phase choices.

The passage around this formula

None of this makes the experiment ambiguous, and this is the paper’s second and sharper result. The branch separations that enter the gravitational phase each mass’s superposition picks up are relational quantities — distances between mass A’s branches and mass B’s branches — and relational quantities do not change when you change which system you have designated the reference frame. Write φij\varphi_{ij} = G mAm_A mBm_B t / (ℏ\hbar dijd_{ij}) for the phase a pair of branches i,j ∈\in \{L,R\} accumulates over interaction time t at separation dijd_{ij} , with G Newton’s constant and ℏ\hbar the reduced Planck constant. Three of the four possible combinations of these branch-pair phases can always be removed…

Read this part in the article →

Learn the underlying idea

A quantum phase is an angle attached to a complex amplitude. One path’s phase can be changed by convention; phase differences between alternative paths can change interference and entanglement.

Open the illustrated quantum phase and two-path entanglement guide →

See this notation across published equations →

Sources cited in the article section

These citations provide research context; check each source for the exact claim it supports.

Further reading for this equation