Quantum Causal Analysis

We suggest a new method of quantum causal analysis. The causality is defined without invoking the time relation. It clarifies Cramer principle of weak causality, which admits time reversal in the entangled states and directly leads to the anticipation. The quantitative quantum measure of causality is the pseudoscalar velocity of irreversible information flow called the course of time. The smaller course of time modulus, the stronger causal connection. The causal parameters for the examples of three-qubit entangled states have been computed. The results have been compared with the degrees of mixedness and entanglement of the states. In the simplest cases the formal measure of quantum causality does not contradict its intuitive understanding. But even in slightly more complicated situations intuition may be a failure.