Outputs
Quantum reference frames, subsystem relativity, and their implications for open quantum systems
Viktoria Kabel
As we describe the world, we almost invariably partition it into subsystems. Restricting to isolated subsystems can be extremely useful in simplifying the physical description. However, this partitioning into subsystems has limitations. First of all, realistic physical systems - in particular gravitational subsystems - are not completely isolated. The study of open quantum systems takes this into account by including the interaction of the system with inaccessible environmental degrees of freedom. However, there is a more fundamental problem: in the presence of symmetries, the partition into subsystems itself may not be absolute. This is the case when studying quantum reference frames (QRFs). While there are several different approaches to modelling such reference frames, they all agree on a fundamental insight: the way we partition the Hilbert space into subsystems - the tensor product structure - depends on the choice of QRF. This subsystem relativity underlies many interesting features of QRFs, such as the frame-dependence of entanglement, entropy, and coherence. Since the study of open quantum systems relies fundamentally on a split into “system” and “environment”, it is natural to ask how our description of these systems, including processes such as decoherence, is affected by a change of QRF. After introducing the general idea of subsystem relativity, I will discuss how and under which conditions changes of QRF lead to a frame-induced decoherence rate and in what way this can affect gravitationally induced decoherence in a simple toy model. Based on arXiv:2607.05578.
Quantum reference frames, subsystem relativity, and their implications for open quantum systems
Viktoria Kabel
As we describe the world, we almost invariably partition it into subsystems. Restricting to isolated subsystems can be extremely useful in simplifying the physical description. However, this partitioning into subsystems has limitations. First of all, realistic physical systems - in particular gravitational subsystems - are not completely isolated. The study of open quantum systems takes this into account by including the interaction of the system with inaccessible environmental degrees of freedom. However, there is a more fundamental problem: in the presence of symmetries, the partition into subsystems itself may not be absolute. This is the case when studying quantum reference frames (QRFs). While there are several different approaches to modelling such reference frames, they all agree on a fundamental insight: the way we partition the Hilbert space into subsystems - the tensor product structure - depends on the choice of QRF. This subsystem relativity underlies many interesting features of QRFs, such as the frame-dependence of entanglement, entropy, and coherence. Since the study of open quantum systems relies fundamentally on a split into “system” and “environment”, it is natural to ask how our description of these systems, including processes such as decoherence, is affected by a change of QRF. After introducing the general idea of subsystem relativity, I will discuss how and under which conditions changes of QRF lead to a frame-induced decoherence rate and in what way this can affect gravitationally induced decoherence in a simple toy model. Based on arXiv:2607.05578.
Relational path integral, effective actions, and quantum frame covariance in gravity
Philipp Höhn
Relational path integral, effective actions, and quantum frame covariance in gravity
Philipp Höhn
Pluralism, Perspectivalism, and Relationality: from Feminist Epistemology to Today’s Physics
Francesca Vidotto
Pluralism, Perspectivalism, and Relationality: from Feminist Epistemology to Today’s Physics
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The perspective-neutral take on quantum reference frames and gravitational entropies
Julian De Vuyst
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Julian De Vuyst
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Anne Catherine de la Hamette
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Anne Catherine de la Hamette
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Francesca Vidotto
Bringing it down to Earth: Quantum gravity from black holes to the lab.
Francesca Vidotto
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Daniele Oriti
The classical gravitational case for relational realism
Daniele Oriti
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Sébastien C. Garmier
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Sébastien C. Garmier
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Lucien Hardy
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Lucien Hardy
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Zixuan Liu
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Zixuan Liu
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Octave Mestoudjian
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Octave Mestoudjian
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Tein van der Lugt (joint work with Robin Lorenz)
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Tein van der Lugt (joint work with Robin Lorenz)
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Sougato Bose
Large quantum fluctuations of the energy momentum tensor and the limits of semiclassical gravity
Alejandro Perez
Large quantum fluctuations of the energy momentum tensor and the limits of semiclassical gravity
Alejandro Perez
Quantum reference frames in QFT and gravity
Robin Simmon
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Robin Simmon
How unitaries encode the trade-off between causal order and locality
Nasra Daher Ahmed
How unitaries encode the trade-off between causal order and locality
Nasra Daher Ahmed
Lectures on “Quantum Reference Frames”
Caslav Brukner
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Caslav Brukner