  Most scholars concerned with the foundations of quantum mechanics (QM) think
that contextuality and nonlocality (hence nonobjectivity of physical
properties) are unavoidable features of QM which follow from the mathematical
apparatus of QM. Moreover these features are usually considered as basic in
quantum information processing. Nevertheless they raise still unsolved
problems, as the objectification problem in the quantum theory of measurement.
The extended semantic realism (ESR) model offers a possible way out from these
difficulties by embedding the mathematical formalism of QM into a broader
mathematical formalism and reinterpreting quantum probabilities as conditional
on detection rather than absolute. The embedding allows to recover the formal
apparatus of QM within the ESR model, and the reinterpretation of QM allows to
construct a noncontextual hidden variables theory which justifies the
assumptions introduced in the ESR model and proves its objectivity. According
to the ESR model both linear and nonlinear time evolution occur, depending on
the physical environment, as in QM. In addition, the ESR model, though
objective, implies modified Bell's inequalities that do not conflict with QM,
supplies different mathematical representations of proper and improper
mixtures, provides a general framework in which the local interpretations of
the GHZ experiment obtained by other authors are recovered and explained, and
supports an interpretation of quantum logic which avoids the introduction of
the problematic notion of quantum truth.
