## What is/are Crossover Theory?

Crossover Theory - This latter quantity, when derived from BCS-BEC crossover theory for fermions, leads to non-monotonic behavior for $T_{\text{BKT}}$ as a function of the attractive interaction or inverse scattering length.^{[1]}Here, we extend the BCS-Bose crossover theory, itself subsumed in BEC, by explicitly including 2hCPs.

^{[2]}Using two theoretical lenses – crossover theory (CT) and emotional contagion theory (ECT) – the present study intends to deepen our understanding by examining whether a teacher’s work passion can be transferred to a student.

^{[3]}With reference to the emotional crossover theory, teachers' nervousness and irritability are hypothesized to intensify students' nervousness and irritability and subsequently dampen their academic motivation and in-class satisfaction.

^{[4]}Building on the work-home resources model and crossover theory, we investigated how workplace ostracism both spills over and crosses over to emotional exhaustion for both the ostracism target and his or her spouse.

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