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Related papers: Quantum limits of a space-time reference frame

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Many models of quintessence predict a time variation of the fundamental constants as well as a composition-dependent gravity like long-range force mediated by the cosmon. We present bounds for the cosmon coupling to matter and radiation…

High Energy Physics - Phenomenology · Physics 2009-11-07 C. Wetterich

The description of relativistic effects requires a preliminary definition of events localised in space-time while the clocks used for time definition and the fields used in synchronisation or localisation procedures are necessarily quantum…

Quantum Physics · Physics 2013-02-27 Marc-Thierry Jaekel , Serge Reynaud

In a background independent theory without boundary, physical observables may be defined with respect to dynamical reference systems. However, I argue here that there may be a symmetry that exchanges the degrees of freedom of the physical…

High Energy Physics - Theory · Physics 2020-07-14 Lee Smolin

Quantum speed limits set an upper bound to the rate at which a quantum system can evolve. Adopting a phase-space approach we explore quantum speed limits across the quantum to classical transition and identify equivalent bounds in the…

Quantum Physics · Physics 2018-02-14 B. Shanahan , A. Chenu , N. Margolus , A. del Campo

We know that space and time are treated almost equally in classical physics, but we also know that this is not the case for quantum mechanics. A quantum description of both space and time is important to really understand the quantum nature…

Quantum Physics · Physics 2024-02-20 Ngo Phuc Duc Loc

The Page-Wootters mechanism questioned the fundamental nature of time in quantum physics. The mechanism explored the notion that a given physical quantity is always defined and measured relative to a reference frame, in general, not…

Quantum Physics · Physics 2019-05-01 Tiago Martinelli , Diogo O. Soares-Pinto

Normally we quantize along the space dimensions but treat time classically. But from relativity we expect a high level of symmetry between time and space. What happens if we quantize time using the same rules we use to quantize space? To do…

Quantum Physics · Physics 2010-05-06 John Ashmead

The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the…

The appearance of Hamiltonian constraint in the canonical formalism for general relativity reflects the lack of a fixed external time. The dynamics of general relativistic systems can be expressed with respect to an arbitrarily chosen…

General Relativity and Quantum Cosmology · Physics 2017-09-21 Przemyslaw Malkiewicz

An extrinsic time is identified in most isotropic and homogeneous cosmological models by matching them with the ideal clock - a parametrized system whose only "degree of freedom" is time -. Once this matching is established, the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 S. C. Beluardi , Rafael Ferraro

Irreversibility implies a preferred flow of time, yet special relativity denies the existence of a preferred clock. This tension has long obstructed the formulation of a relativistic master equation: standard Markovian approximations either…

Quantum Physics · Physics 2025-12-23 Pranav Vaidhyanathan , Gerard J. Milburn

In the quantization of gauge theories and quantum gravity, it is crucial to treat reference frames such as rods or clocks not as idealized external classical relata, but as internal quantum subsystems. In the Page-Wootters formalism, for…

Quantum Physics · Physics 2023-01-02 Anne-Catherine de la Hamette , Stefan L. Ludescher , Markus P. Mueller

Exact solutions of time-dependent Schr\"odinger equation in presence of time-dependent potential is defined by point transformation and separation of variables. Energy and Heisenberg uncertainty relation are pursued for time-independent…

Quantum Physics · Physics 2021-11-04 Debraj Nath

In this article we consider the bounds on the noncommutative nature of space-time. We argue that these bounds are extremely model dependent. In the only phenomenologically viable framework, i.e. when the fields are taken to be in the…

High Energy Physics - Phenomenology · Physics 2011-09-13 Xavier Calmet

The use of a relational time in quantum mechanics is a framework in which one promotes to quantum operators all variables in a system, and later chooses one of the variables to operate like a ``clock''. Conditional probabilities are…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Rodolfo Gambini , Rafael Porto , Jorge Pullin

The current theories of quantum physics and general relativity on their own do not allow us to study situations in which the gravitational source is quantum. Here, we propose a strategy to determine the dynamics of objects in the presence…

Our recent paper (arXiv:1701.04298 [quant-ph]) discussed the occurrence of a coupling of centre of mass and internal degrees of freedom for complex quantum systems in non-inertial frames. There, we pointed out that an external force…

Quantum Physics · Physics 2017-04-10 Marko Toroš , André Großardt , Angelo Bassi

The relativistic conception of space and time is challenged by the quantum nature of physical observables. It has been known for a long time that Poincar\'e symmetry of field theory can be extended to the larger conformal symmetry. We use…

Quantum Physics · Physics 2013-02-27 Marc-Thierry Jaekel , Serge Reynaud

This paper proposes an intrinsic or background-independent quantum framework based on entangled state rather than absolute quantum state, it describes a quantum relative state between the under-study quantum system and the quantum measuring…

Quantum Physics · Physics 2026-03-13 M. J. Luo

Given the lack of an absolute time parameter in general relativistic systems, quantum cosmology often describes the expansion of the universe in terms of relational changes between two degrees of freedom, such as matter and geometry.…

General Relativity and Quantum Cosmology · Physics 2023-10-16 Luis Martinez , Martin Bojowald , Garrett Wendel