The notation "+ h.c." is used as a shorthand to omit writing out half of the terms actually present in an expression.
Notes on verification
Matches standard physics notation convention as described in multiple independent sources (Physics Forums, ResearchGate) and Wikipedia; consistent with how 'h.c.' is used in quantum mechanics and field theory literature. [tier=bronze indep_score=0.3 clusters=2 claim_tier=everyday]