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 neutral theory of biodiversity not straight, but the slope changes from being steep at small areas, shallower at intermediate areas, and steep at the largest areas. The formula for species composition may be used to calculate the expected number of species present in a community under the assumptions of the Unified Theory. In symbols where θ is the fundamental biodiversity number. This formula specifies the expected number of species sampled in a community of size "J". The last term, formula_63, is the expected number of "new" species encountered when adding one new individual to the community. This is an increasing function of θ and