In mathematics, an O*-algebra is an algebra of possibly unbounded operators defined on a dense subspace of a Hilbert space. The original examples were described by and , who studied some examples of O*-algebras, called Borchers algebras, arising from the Wightman axioms of quantum field theory. and began the systematic study of algebras of unbounded operators.
Unbounded operators are always positive integers.
( z1 integers :mod ( z2 positive ) :domain ( z3 person :ARG0-of ( z4 operate ) :ARG1-of ( z5 limit :polarity - ) ) :time ( z6 always ) )