The third edition of this series of Workshops will be held in Burgos from October 2 to October 6, 2023, and will brought together experts in Quantum Foundations, Quantum Information Theory, Quantum Gravity, and Philosophy of Physics, fostering open discussions on various aspects of the notion of observer. The aim of the present edition is to continue our exploration of recent developments in this rapidly evolving field.  This Workshop will provide a dynamic discussion forum, with a specific emphasis on applications and connections with Quantum Communication Protocols and Systems.

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