Is Hardy's paradox a paradox?

TL;DR

This paper clarifies that Hardy's thought experiment is not a paradox and can be explained using standard quantum mechanics without weak measurements, emphasizing the role of projective measurements in understanding it.

Contribution

It demonstrates that Hardy's experiment does not constitute a paradox and provides a straightforward quantum mechanical explanation, correcting common misconceptions.

Findings

Hardy's experiment is not a paradox when properly analyzed.

Standard quantum mechanics suffices to explain the experiment.

Misinterpretations arise from ignoring the role of projective measurements.

Abstract

In the present Note it is shown that Hardy thought experiment does not lead to any paradox and its explanation can be made by using quantum mechanical methods, without the need of weak measurements theories. The confusion arising about this thought experiment follows from ignoring the use of a projective measurement of the kind of knowledge. A certain comment about the realization of Hardy thought experiment with photons is made.