Classical unified field theories since antisymmetry seemed essential for electromagnetism, the symmetry requirement was relaxed for one or both fields. Einstein's proposed unified-field equations (fundamental laws of physics) were generally derived from a variational principle expressed in terms of the Riemann curvature tensor for the presumed space-time manifold. In field theories of this kind, particles appear as limited regions in space-time in which the field strength or the energy density are particularly high. Einstein and coworker Leopold Infeld managed to demonstrate that, in Einstein's final theory of the unified field, true singularities of the field did have trajectories resembling point particles. However, singularities are
Unified budget Unified budget In the United States a unified budget is a federal government budget in which receipts and outlays from federal funds and the Social Security Trust Fund are consolidated. The change to a unified budget resulted in a single measure of the fiscal status of the government, based on the sum of all government activity. When these fund groups are consolidated to display budget totals, transactions that are outlays of one fund group (i.e., interfund transactions) are deducted to avoid double counting. The United States government adopted a unified budget in the Johnson administration in 1968, beginning with the