Dear Colleagues,

Astronomy has always been the driving force behind the innovation and development of science. For ancient civilizations, the desire to understand the movement of celestial objects was the motivation to elaborate on trigonometry, algebra, and natural philosophy. For Isaac Newton, the urge to observe distant objects prompted him to construct improved optical instruments. In modern times, science benefited enormously from the Space Race, which resulted in broadening our knowledge and providing multiple technologies. Currently, astronomy has been pushed to the limits, where quantum effects are unavoidable. In this new era, we can talk about Quantum Astronomy, and the prospects of this emerging field are twofold.

First, numerous tests of the fundamental laws of physics can be conceptualized with artificial satellites in Earth orbits or elsewhere in the solar system. Such tests could verify the applicability of quantum theory at larger distances (e.g., entanglement tests, quantum gravity experiments, or relativistic effects in quantum information theory). Additionally, prospective technologies that can enable quantum communication in space have the potential to elevate our understanding of the universe to a higher level.

Secondly, further progress in imaging and spectroscopy requires the quantum properties of light to be taken into account. Presently, existing apparatus measures only selected aspects of the first-order coherence of light (spatial or temporal). However, photons have additional degrees of freedom, which are utilized in quantum optics to encode information. From the astronomical perspective, we can expect that such properties of light carry extra information about the source emitting the beam. Additionally, the quantum features of photons may indicate whether the light has reached the observer directly or through an intermediate process. If quantum effects are properly addressed, astronomical quantum optics can help to extract additional knowledge about the farthest objects in the universe. On the other hand, it can also stimulate the progress of quantum optics itself since present theories and methods may not be sufficient to embrace the vastness of the information coming from the space.

For this Special Issue, we plan to collect papers that relate to any aspect of the overlap between astronomy and quantum physics.

The scope of the Special Issue includes (but is not limited to):

• Tests of fundamental quantum physics in the space,
• Satellite quantum key distribution,
• Quantum limits in optical astronomy,
• Quantum optics instrumentation for astronomy,
• Many-worlds interpretation of quantum mechanics,
• The wave function of the universe,
• Quantum gravity,
• Quantum cosmology,
• Philosophical foundations of the quantum universe,
• Quantum information, consciousness, and the universe,
• Other quantum effects related to astronomy.

Dr. Artur Czerwinski
Guest Editor

Manuscript Submission Information

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• photonic astronomy
• quantum optics
• satellite quantum key distribution
• tests of fundamental quantum physics
• quantum theory
• quantum effects in astronomy
• quantum entanglement
• Bell tests
• quantum information
• quantum optics instrumentation for astronomy