Warped geometries acquire their full meaning when we substitute the variable
y for
t, time and
x, for
s, space. Then the
f(
y) factor of the spatial dimension becomes the effect of time that in words of Einstein "curves space". How it curves space will define one or other solution to a space-time world. For that reason, different models of space-time use warped geometries. Many basic solutions of the
Einstein field equations are warped geometries, for example, the
Schwarzschild solution and the
Friedmann–Lemaitre–Robertson–Walker models. Also, warped geometries are the key building block of
Randall–Sundrum models in
string theory. ==See also==