 Transpose

The matrix transpose interchanges rows and columns: $(A^T{)}_{ij}=A_{ji}$. On a fixed matrix space, $A\mapsto A^T$ is the transposition map, a linear map that preserves the trace norm but is not completely positive in dimensions greater than one.

The term "transpose" can refer to different concepts depending on the context. Here are a few common meanings: 1. **Mathematics (Linear Algebra)**: In the context of matrices, the transpose of a matrix is a new matrix whose rows are the columns of the original matrix, and whose columns are the rows of the original matrix.