弦論

string theory (in theoretical physics)

bow string / string of musical instrument / watchspring / chord (segment of curve) / hypotenuse / CL:根[gen1]

abbr. for 論語|论语[Lun2 yu3], The Analects (of Confucius)

opinion / view / theory / doctrine / to discuss / to talk about / to regard / to consider / per / by the (kilometer, hour etc)