**Joy ($F_{\text{Joy}}$):** Joy is measurable as the positive gradient of coherence—the rate of coherence increase or the stable attainment of high coherence. It is the affective signature of alignment with increasing order.
Where \Theta is the Heaviside step function ensuring the state term only activates above threshold.
Time derivative of coherence operator:
Where \mathcal{L} is the Lindbladian capturing non-unitary coherence dynamics.
Definition (Joy Metric): Let C: \mathcal{M} \times \mathbb{R} \to \mathbb{R}_+ be a coherence function on state space \mathcal{M} parameterized by time. The Joy metric at state \psi and time t is:
Where H is the Heaviside function.