Question

what is tensor calculas?

Answer 1

A tensor is not a scalar , a vector or anything. Its just an abstract quantity that obeys the coordinate transformation law. Anything that satisfies the law is a tensor, thats it!.

Used For : In mathematics, tensors are geometric objects that describe linear relations between geometric vectors, scalars, and other tensors. Elementary examples of such relations include the dot product, the cross product, and linear maps. ... A vector is represented as a 1-dimensional array in a basis, and is a 1st-order tensor.

;-)

Answer 2

Tensor calculus or tensor analysis is an extension of vector calculus to tensor fields (tensors that may vary over a manifold, e.g. in spacetime). Developed by Gregorio Ricci-Curbastro and his student Tullio Levi-Civita, it was used by Albert Einstein to develop his theory of general relativity.