| flat universe | is a kind of big bang |  |
| has definition Big Bang model that was formulated by Friedmann and Lemaitre which has a zero curvature, or flat (Euclidian). This space is unbounded. | |
| has definition A Universe in which there is no curvature to the spacetime continuum. This means that the kinetic energy of the expansion is exactly balanced by the potential gravitational energy of the matter. Thus, after an infinite amount of time the Universe will stop expanding. | |
| has definition A homogeneous, isotropic universe is called flat if it is just on the borderline between being spatially closed and spatially open, so the geometry is precisely Euclidean. If Einstein's cosmological constant is zero, then a flat universe will go on expanding forever, but the velocity of recession between any two objects would approach zero at large times. | |
| has definition A universe that is at the boundary between an open and closed universe. In a flat universe, the average mass density always has precisely the critical value. A flat universe has zero total energy and an infinite size. Flat universes have the geometry of an infinite, flat surface, that is, Euclidean geometry. The value of omega is 1 for a flat universe. (See closed universe; critical mass density; Euclidean geometry; omega; open universe.) | |
| has definition A Friedmann model of the Universe in which the spacetime continuum is not curved. | |
| has definition A homogeneous world model (the simplest relativistic model) of finite density, zero curvature, and nonzero cosmological constant, subject to the field equations of general relativity in an expanding Euclidean space. The radius increases rapidly from zero, and, although it always increases, the rate of increase becomes less as time goes on. | |
| has definition The flat (k = 0), pressureless standard model of the universe. | |
| has definition A particular solution to Einstein's cosmological equations in which the universe is flat. (See flat universe.) | |
| has definition The Friedmann-Lemaitre model in which space is Euclidean was advocated by Einstein and de Sitter in 1932. | |
| has definition A cosmological model in which a static (neither expanding nor collapsing) universe is maintained by introducing a cosmological repulsion force (in the form of the cosmological constant) to counterbalance the gravitational force. | |
| has definition A world model of a static universe with a positive cosmological constant, whose radius of curvature is constant and independent of time. | |
| has geometry of space flat or Euclidian | |
| has synonym Einstein-de Sitter universe | |
| big bang | has antonym big crunch | |
| cosmology theory | has domain cosmology | |
| theory | has validity correct or incorrect with caveats | |
| has author or reasearch group | |
| has date or a range of dates for which the theory was active | |
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