Unifying spacetime approaches to quantum mechanics

• URL: http://arxiv.org/abs/2606.12539v1
• Date: Wed, 10 Jun 2026 18:00:09 GMT
• Title: Unifying spacetime approaches to quantum mechanics
• Abstract summary: We study the objects that play the role of quantum states in the recently introduced framework of spacetime quantum mechanics.<n>Path integrals, quantum states over time, pseudo-density matrices, the Page and Wootters mechanism, superdensity operators, and timelike-entanglement proposals all arise from spacetime states.<n>This unification provides explicit mathematical representations of these formalisms, reveals relations among them, and clarifies the spacetime information each one captures.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Recent efforts to formulate quantum mechanics in a way that treats space and time on a more equal footing have led to a large variety of spacetime-oriented approaches. In this work we present a detailed study of spacetime states, the objects that play the role of quantum states in the recently introduced framework of spacetime quantum mechanics, and show that the main proposals in the literature are different manifestations of the same underlying object. Path integrals, quantum states over time, pseudo-density matrices, the Page and Wootters mechanism, superdensity operators, and timelike-entanglement proposals all arise from spacetime states through particular evaluations, reduced information, linear maps, or quantum channels. This unification provides explicit mathematical representations of these formalisms, reveals relations among them, and clarifies the spacetime information each one captures. We also study the broader relevance of the spacetime-state point of view for Leggett-Garg inequalities, OTOCs, temporal tensor networks, fermionic systems, relativistic QFTs, quantum reference frames, and classical physics, together with additional insights and perspectives revealed by the common unifying framework.

Related papers

• On the Emergence of Time and Space in Closed Quantum Systems [0.0]
  We study how entanglement can be at the basis of the emergence of time and space within closed quantum systems.<n>We provide a model of 3+1 dimensional, quantum spacetime emerging from entanglement among different subsystems in a globally "timeless" and "positionless" Universe.
  arXiv  Detail & Related papers  (2025-12-08T23:58:11Z)
• Temporal Entanglement from Holographic Entanglement Entropy [44.99833362998488]
  We propose a systematic prescription to characterize temporal entanglement in quantum field theory.<n>For holographic quantum field theories, our prescription amounts to an analytic continuation of all co-dimension-two bulk extremal surfaces.<n>We show that it leads to results with self-consistent physical properties of temporal entanglement.
  arXiv  Detail & Related papers  (2025-07-23T18:14:21Z)
• Spacetime quantum mechanics for bosonic and fermionic systems [0.0]
  We provide a Hilbert space approach to quantum mechanics where space and time are treated on an equal footing.<n>We show that these states are solutions to a quantum principle of stationary action enabled by the novel notion of timelike correlations.
  arXiv  Detail & Related papers  (2025-06-12T00:27:19Z)
• Emergent Holographic Spacetime from Quantum Information [0.0]
  Holographic duality describes gravitational theories in terms of quantum many-body systems.<n> quantum information theory provides a crucial tool that directly connects microscopic structures of these systems to the geometries of gravitational spacetimes.
  arXiv  Detail & Related papers  (2025-06-07T00:05:10Z)
• Quantum Information meets High-Energy Physics: Input to the update of the European Strategy for Particle Physics [43.15404275280645]
  Some of the most astonishing and prominent properties of Quantum Mechanics, such as entanglement and Bell nonlocality, have only been studied extensively in dedicated low-energy laboratory setups.<n>The feasibility of these studies in the high-energy regime explored by particle colliders was only recently shown and has gathered the attention of the scientific community.
  arXiv  Detail & Related papers  (2025-03-31T18:00:01Z)
• Quantum Time: a novel resource for quantum information [0.0]
  Time in relativity theory has a status different from that adopted by standard quantum mechanics. Time is considered as a parameter measured with reference to an external absolute Newtonian frame.
  arXiv  Detail & Related papers  (2023-10-25T13:13:59Z)
• Quantum data learning for quantum simulations in high-energy physics [55.41644538483948]
  We explore the applicability of quantum-data learning to practical problems in high-energy physics. We make use of ansatz based on quantum convolutional neural networks and numerically show that it is capable of recognizing quantum phases of ground states. The observation of non-trivial learning properties demonstrated in these benchmarks will motivate further exploration of the quantum-data learning architecture in high-energy physics.
  arXiv  Detail & Related papers  (2023-06-29T18:00:01Z)
• Overlapping qubits from non-isometric maps and de Sitter tensor networks [41.94295877935867]
  We show that processes in local effective theories can be spoofed with a quantum system with fewer degrees of freedom. We highlight how approximate overlapping qubits are conceptually connected to Hilbert space dimension verification, degree-of-freedom counting in black holes and holography.
  arXiv  Detail & Related papers  (2023-04-05T18:08:30Z)
• Time and Evolution in Quantum and Classical Cosmology [68.8204255655161]
  We show that it is neither necessary nor sufficient for the Poisson bracket between the time variable and the super-Hamiltonian to be equal to unity in all of the phase space. We also discuss the question of switching between different internal times as well as the Montevideo interpretation of quantum theory.
  arXiv  Detail & Related papers  (2021-07-02T09:17:55Z)
• Spacetime Quantum Actions [0.0]
  We propose a formulation of quantum mechanics in an extended Fock space in which a tensor product structure is applied to time. Subspaces of histories consistent with the dynamics of a particular theory are defined by a direct quantum generalization of the corresponding classical action. The diagonalization of such quantum actions enables us to recover the predictions of conventional quantum mechanics and reveals an extended unitary equivalence between all physical theories.
  arXiv  Detail & Related papers  (2020-10-18T23:14:10Z)
• Preferred basis, decoherence and a quantum state of the Universe [77.34726150561087]
  We review a number of issues in foundations of quantum theory and quantum cosmology. These issues can be considered as a part of the scientific legacy of H.D. Zeh.
  arXiv  Detail & Related papers  (2020-06-28T18:07:59Z)
• Projection evolution and quantum spacetime [68.8204255655161]
  We discuss the problem of time in quantum mechanics. An idea of construction of a quantum spacetime as a special set of the allowed states is presented. An example of a structureless quantum Minkowski-like spacetime is also considered.
  arXiv  Detail & Related papers  (2019-10-24T14:54:11Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.