Abstract
The geometry of the state space of a finite-dimensional quantum mechanical system, with particular reference to four dimensions, is studied. Many novel features, not evident in the two-dimensional space of a single spin, are found. Although the state space is a convex set, it is not a ball, and its boundary contains mixed states in addition to the pure states, which form a low-dimensional submanifold. The appropriate language to describe the role of the observer is that of flag manifolds.
| Original language | English |
|---|---|
| Pages (from-to) | 211-223 |
| Number of pages | 13 |
| Journal | Foundations of Physics |
| Volume | 23 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 1993 |