El formalismo de contextos generalizados y la medición cuántica

In this paper, the measurement process of a quantum system is described as an interaction of two physical systems: the system to be measured and the measuring instrument. Both systems form a composite system and its temporal evolution is determined solely by the Schrodinger equation, i.e., there is no collapse postulate. The description of the measurement process is performed using a formalism of quantum histories called formalism of Generalized Contexts. This formalism allows to express, using the conditional probability, the correlation between the properties corresponding to the measured observable, before the measurement, and the properties corresponding to the pointer variable of the measurement instrument, after the measurement. Using this formalism, two central problems of quantum measurement are discussed: the problem of definite outcome and the problem of preferred basis.