Unified field theory of (the not mathematically well-defined) quantum electrodynamics. One can extend this system to include the weak and strong nuclear forces to get the Einstein–Yang–Mills–Dirac System. The French physicist Marie-Antoinette Tonnelat published a paper in the early 1940s on the standard commutation relations for the quantized spin-2 field. She continued this work in collaboration with Erwin Schrödinger after World War II. In the 1960s Mendel Sachs proposed a generally covariant field theory that did not require recourse to renormalisation or perturbation theory. In 1965, Tonnelat published a book on the state of research on unified field theories. In 1963 American physicist
Pasadena Unified School District Pasadena Unified School District The Pasadena Unified School District is a unified school district that is responsible for the schools of Pasadena, California. , it has four high schools, five middle schools, three K–8 schools and 15 K–5 elementary schools. The number of elementary schools was reduced from 18 at the end of the 2010–11 school year. The district also serves the city of Sierra Madre and the unincorporated community of Altadena. PUSD is run by a board of education, whose members serve four-year terms. Duties of the board include budgeting, approving expenditures, establishing policy, making employment decisions, approving textbooks