Keyboard graph navigation: press N for concepts or E for relations; use arrow keys, Home, and End to move; Enter selects; Shift plus Enter selects and centers; plus and minus zoom; zero fits; Escape clears the selection. Use the visible viewport buttons as alternatives to dragging, wheel, and pinch gestures.
Canonical static concept record
Open this concept in the interactive graphRead the Markdown equivalent
The reduced Einstein equations governing the scale factor of an FLRW universe from its energy density, pressure, spatial curvature, and cosmological constant.
wp-physics-friedmann-equationsnasa-big-bangeinstein-equationEach relation below ends at this concept.
This is an authored directed relation from the source endpoint to the target endpoint.
Substituting the homogeneous and isotropic FLRW metric and perfect-fluid stress–energy into Einstein’s equation yields the Friedmann equations.
Record a genuine theorem implication that is not part of the target definition; these edges may point toward a weaker structure.
einstein-equationnasa-big-bangtong-grwp-physics-flrw-spacetimewp-physics-friedmann-equationsThis is an authored directed relation from the source endpoint to the target endpoint.
For an FLRW geometry, the stress–energy tensor—usually modeled as a homogeneous isotropic fluid—provides the density and pressure terms in the Friedmann equations.
The source supplies a substantive formal ingredient, dynamical sector, law, field content, or mechanism of the target theoretical framework.
einstein-equationnasa-big-bangEach relation below starts at this concept.
This is an authored directed relation from the source endpoint to the target endpoint.
Solutions with increasing scale factor describe cosmic expansion.
A theory, law, or interaction describes the behavior of the target within a stated regime. The edge detail must state important limits or qualifications.
nasa-big-bangnasa-dark-energy