The stress–energy tensor is a tensor physical quantity. A vector quantity is a tensor quantity that contains two components. A scalar quantity is a tensor quantity that contains only one component. These are special cases of tensors, being the simplest kind. But…
read moreDerivation of the Friedmann Equations[1] from the Newtonian First Derivative of the Scale Factor a is the scale factor, not acceleration. Notice it is not expressed as a vector. The scale factor is scalar; It has no direction, only magnitude. It describes the instantaneous…
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