Equation 134 · Part 3 · The Entry a Relabeling Cannot Write

=

H_c = H_f

What this part means

The expressions on both sides represent the same quantity under the stated assumptions.

Its job in the formula

The equals sign connects the complete expression on the left with the complete expression on the right. Both sides must have compatible units.

Full expression=Article meaning

The passage around this formula

the detuned Hamiltonian that governs spin precession in a frame rotating with an applied field — the identical construction I. I. Rabi used to analyze spin behavior in a gyrating magnetic field in 1937 [ 14 ] . Two checks confirm the recovery is exact rather than incidental: at $\omega_r$ = 0 , the non-rotating case, $\Delta_{\rm frame}$ $\equiv$ 0 and $H_c$ = $H_f$ , the already-verified baseline; at $\omega_r$ = $\omega_0$ , exact corotation, $H_c$ = 0 and the spin’s energy in this frame vanishes identically, which is the ordinary resonance condition, not a puzzle, because $\Delta_{\rm frame}$ = - $\hbar$ $\omega_0$ $\langle$ $\sigma_z$ $\rangle$ /2 exactly cancels the lab-frame value for a state that starts, and stays,…

Read this part in the article →

Learn the underlying idea

An equals sign says that the expression on its left and the expression on its right have the same value under the stated definitions and assumptions.

Open the illustrated equality: what the equals sign claims guide →

Sources cited in the surrounding passage

[14] Space Quantization in a Gyrating Magnetic Field ↗

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