A large binary operator representing repeated tensor products or external products in linear algebra and differential geometry.
Examples
Tensor product of vector spaces
V_1 \bigotimes V_2 \bigotimes V_3
Tensor product of multiple sets
\bigotimes_{i=1}^n X_i = X_1 \otimes X_2 \otimes \cdots \otimes X_n
Tensor product of Hilbert spaces
\mathcal{H} = \bigotimes_{j=1}^N \mathcal{H}_j