tiheysmatriiseille
Tiheysmatriiseille refers to a concept in linear algebra and related fields that deals with matrices whose entries represent densities. The term itself is Finnish, combining "tiheys" (density) and "matriiseille" (for matrices). In essence, a tiheysmatriisi, or density matrix, is a mathematical object used to describe the statistical state of a quantum mechanical system. It generalizes the concept of a pure state by allowing for the description of mixed states, which are probabilistic ensembles of pure states.
The density matrix is a non-negative self-adjoint operator with a trace equal to one. For a pure
Density matrices are particularly useful in quantum mechanics for describing systems that are not perfectly known,